1/* Target hook definitions. 2 Copyright (C) 2001-2016 Free Software Foundation, Inc. 3 4 This program is free software; you can redistribute it and/or modify it 5 under the terms of the GNU General Public License as published by the 6 Free Software Foundation; either version 3, or (at your option) any 7 later version. 8 9 This program is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 GNU General Public License for more details. 13 14 You should have received a copy of the GNU General Public License 15 along with this program; see the file COPYING3. If not see 16 <http://www.gnu.org/licenses/>. 17 18 In other words, you are welcome to use, share and improve this program. 19 You are forbidden to forbid anyone else to use, share and improve 20 what you give them. Help stamp out software-hoarding! */ 21 22/* See target-hooks-macros.h for details of macros that should be 23 provided by the including file, and how to use them here. */ 24#include "target-hooks-macros.h" 25 26#undef HOOK_TYPE 27#define HOOK_TYPE "Target Hook" 28 29HOOK_VECTOR (TARGET_INITIALIZER, gcc_target) 30 31/* Functions that output assembler for the target. */ 32#define HOOK_PREFIX "TARGET_ASM_" 33HOOK_VECTOR (TARGET_ASM_OUT, asm_out) 34 35/* Opening and closing parentheses for asm expression grouping. */ 36DEFHOOKPOD 37(open_paren, 38 "These target hooks are C string constants, describing the syntax in the\n\ 39assembler for grouping arithmetic expressions. If not overridden, they\n\ 40default to normal parentheses, which is correct for most assemblers.", 41 const char *, "(") 42DEFHOOKPODX (close_paren, const char *, ")") 43 44/* Assembler instructions for creating various kinds of integer object. */ 45DEFHOOKPOD 46(byte_op, 47 "@deftypevrx {Target Hook} {const char *} TARGET_ASM_ALIGNED_HI_OP\n\ 48@deftypevrx {Target Hook} {const char *} TARGET_ASM_ALIGNED_SI_OP\n\ 49@deftypevrx {Target Hook} {const char *} TARGET_ASM_ALIGNED_DI_OP\n\ 50@deftypevrx {Target Hook} {const char *} TARGET_ASM_ALIGNED_TI_OP\n\ 51@deftypevrx {Target Hook} {const char *} TARGET_ASM_UNALIGNED_HI_OP\n\ 52@deftypevrx {Target Hook} {const char *} TARGET_ASM_UNALIGNED_SI_OP\n\ 53@deftypevrx {Target Hook} {const char *} TARGET_ASM_UNALIGNED_DI_OP\n\ 54@deftypevrx {Target Hook} {const char *} TARGET_ASM_UNALIGNED_TI_OP\n\ 55These hooks specify assembly directives for creating certain kinds\n\ 56of integer object. The @code{TARGET_ASM_BYTE_OP} directive creates a\n\ 57byte-sized object, the @code{TARGET_ASM_ALIGNED_HI_OP} one creates an\n\ 58aligned two-byte object, and so on. Any of the hooks may be\n\ 59@code{NULL}, indicating that no suitable directive is available.\n\ 60\n\ 61The compiler will print these strings at the start of a new line,\n\ 62followed immediately by the object's initial value. In most cases,\n\ 63the string should contain a tab, a pseudo-op, and then another tab.", 64 const char *, "\t.byte\t") 65DEFHOOKPOD (aligned_op, "*", struct asm_int_op, TARGET_ASM_ALIGNED_INT_OP) 66DEFHOOKPOD (unaligned_op, "*", struct asm_int_op, TARGET_ASM_UNALIGNED_INT_OP) 67 68/* The maximum number of bytes to skip when applying 69 LABEL_ALIGN_AFTER_BARRIER. */ 70DEFHOOK 71(label_align_after_barrier_max_skip, 72 "The maximum number of bytes to skip before @var{label} when applying\n\ 73@code{LABEL_ALIGN_AFTER_BARRIER}. This works only if\n\ 74@code{ASM_OUTPUT_MAX_SKIP_ALIGN} is defined.", 75 int, (rtx_insn *label), 76 default_label_align_after_barrier_max_skip) 77 78/* The maximum number of bytes to skip when applying 79 LOOP_ALIGN. */ 80DEFHOOK 81(loop_align_max_skip, 82 "The maximum number of bytes to skip when applying @code{LOOP_ALIGN} to\n\ 83@var{label}. This works only if @code{ASM_OUTPUT_MAX_SKIP_ALIGN} is\n\ 84defined.", 85 int, (rtx_insn *label), 86 default_loop_align_max_skip) 87 88/* The maximum number of bytes to skip when applying 89 LABEL_ALIGN. */ 90DEFHOOK 91(label_align_max_skip, 92 "The maximum number of bytes to skip when applying @code{LABEL_ALIGN}\n\ 93to @var{label}. This works only if @code{ASM_OUTPUT_MAX_SKIP_ALIGN}\n\ 94is defined.", 95 int, (rtx_insn *label), 96 default_label_align_max_skip) 97 98/* The maximum number of bytes to skip when applying 99 JUMP_ALIGN. */ 100DEFHOOK 101(jump_align_max_skip, 102 "The maximum number of bytes to skip before @var{label} when applying\n\ 103@code{JUMP_ALIGN}. This works only if\n\ 104@code{ASM_OUTPUT_MAX_SKIP_ALIGN} is defined.", 105 int, (rtx_insn *label), 106 default_jump_align_max_skip) 107 108/* Try to output the assembler code for an integer object whose 109 value is given by X. SIZE is the size of the object in bytes and 110 ALIGNED_P indicates whether it is aligned. Return true if 111 successful. Only handles cases for which BYTE_OP, ALIGNED_OP 112 and UNALIGNED_OP are NULL. */ 113DEFHOOK 114(integer, 115 "The @code{assemble_integer} function uses this hook to output an\n\ 116integer object. @var{x} is the object's value, @var{size} is its size\n\ 117in bytes and @var{aligned_p} indicates whether it is aligned. The\n\ 118function should return @code{true} if it was able to output the\n\ 119object. If it returns false, @code{assemble_integer} will try to\n\ 120split the object into smaller parts.\n\ 121\n\ 122The default implementation of this hook will use the\n\ 123@code{TARGET_ASM_BYTE_OP} family of strings, returning @code{false}\n\ 124when the relevant string is @code{NULL}.", 125 /* Only handles cases for which BYTE_OP, ALIGNED_OP and UNALIGNED_OP are 126 NULL. */ 127 bool, (rtx x, unsigned int size, int aligned_p), 128 default_assemble_integer) 129 130/* Notify the backend that we have completed emitting the data for a 131 decl. */ 132DEFHOOK 133(decl_end, 134 "Define this hook if the target assembler requires a special marker to\n\ 135terminate an initialized variable declaration.", 136 void, (void), 137 hook_void_void) 138 139/* Output code that will globalize a label. */ 140DEFHOOK 141(globalize_label, 142 "This target hook is a function to output to the stdio stream\n\ 143@var{stream} some commands that will make the label @var{name} global;\n\ 144that is, available for reference from other files.\n\ 145\n\ 146The default implementation relies on a proper definition of\n\ 147@code{GLOBAL_ASM_OP}.", 148 void, (FILE *stream, const char *name), 149 default_globalize_label) 150 151/* Output code that will globalize a declaration. */ 152DEFHOOK 153(globalize_decl_name, 154 "This target hook is a function to output to the stdio stream\n\ 155@var{stream} some commands that will make the name associated with @var{decl}\n\ 156global; that is, available for reference from other files.\n\ 157\n\ 158The default implementation uses the TARGET_ASM_GLOBALIZE_LABEL target hook.", 159 void, (FILE *stream, tree decl), default_globalize_decl_name) 160 161/* Output code that will declare an external variable. */ 162DEFHOOK 163(assemble_undefined_decl, 164 "This target hook is a function to output to the stdio stream\n\ 165@var{stream} some commands that will declare the name associated with\n\ 166@var{decl} which is not defined in the current translation unit. Most\n\ 167assemblers do not require anything to be output in this case.", 168 void, (FILE *stream, const char *name, const_tree decl), 169 hook_void_FILEptr_constcharptr_const_tree) 170 171/* Output code that will emit a label for unwind info, if this 172 target requires such labels. Second argument is the decl the 173 unwind info is associated with, third is a boolean: true if 174 this is for exception handling, fourth is a boolean: true if 175 this is only a placeholder for an omitted FDE. */ 176DEFHOOK 177(emit_unwind_label, 178 "This target hook emits a label at the beginning of each FDE@. It\n\ 179should be defined on targets where FDEs need special labels, and it\n\ 180should write the appropriate label, for the FDE associated with the\n\ 181function declaration @var{decl}, to the stdio stream @var{stream}.\n\ 182The third argument, @var{for_eh}, is a boolean: true if this is for an\n\ 183exception table. The fourth argument, @var{empty}, is a boolean:\n\ 184true if this is a placeholder label for an omitted FDE@.\n\ 185\n\ 186The default is that FDEs are not given nonlocal labels.", 187 void, (FILE *stream, tree decl, int for_eh, int empty), 188 default_emit_unwind_label) 189 190/* Output code that will emit a label to divide up the exception table. */ 191DEFHOOK 192(emit_except_table_label, 193 "This target hook emits a label at the beginning of the exception table.\n\ 194It should be defined on targets where it is desirable for the table\n\ 195to be broken up according to function.\n\ 196\n\ 197The default is that no label is emitted.", 198 void, (FILE *stream), 199 default_emit_except_table_label) 200 201/* Emit a directive for setting the personality for the function. */ 202DEFHOOK 203(emit_except_personality, 204 "If the target implements @code{TARGET_ASM_UNWIND_EMIT}, this hook may be\ 205 used to emit a directive to install a personality hook into the unwind\ 206 info. This hook should not be used if dwarf2 unwind info is used.", 207 void, (rtx personality), 208 NULL) 209 210/* Emit any directives required to unwind this instruction. */ 211DEFHOOK 212(unwind_emit, 213 "This target hook emits assembly directives required to unwind the\n\ 214given instruction. This is only used when @code{TARGET_EXCEPT_UNWIND_INFO}\n\ 215returns @code{UI_TARGET}.", 216 void, (FILE *stream, rtx_insn *insn), 217 NULL) 218 219DEFHOOKPOD 220(unwind_emit_before_insn, 221 "True if the @code{TARGET_ASM_UNWIND_EMIT} hook should be called before\ 222 the assembly for @var{insn} has been emitted, false if the hook should\ 223 be called afterward.", 224 bool, true) 225 226/* Generate an internal label. 227 For now this is just a wrapper for ASM_GENERATE_INTERNAL_LABEL. */ 228DEFHOOK_UNDOC 229(generate_internal_label, 230 "", 231 void, (char *buf, const char *prefix, unsigned long labelno), 232 default_generate_internal_label) 233 234/* Output an internal label. */ 235DEFHOOK 236(internal_label, 237 "A function to output to the stdio stream @var{stream} a label whose\n\ 238name is made from the string @var{prefix} and the number @var{labelno}.\n\ 239\n\ 240It is absolutely essential that these labels be distinct from the labels\n\ 241used for user-level functions and variables. Otherwise, certain programs\n\ 242will have name conflicts with internal labels.\n\ 243\n\ 244It is desirable to exclude internal labels from the symbol table of the\n\ 245object file. Most assemblers have a naming convention for labels that\n\ 246should be excluded; on many systems, the letter @samp{L} at the\n\ 247beginning of a label has this effect. You should find out what\n\ 248convention your system uses, and follow it.\n\ 249\n\ 250The default version of this function utilizes @code{ASM_GENERATE_INTERNAL_LABEL}.", 251 void, (FILE *stream, const char *prefix, unsigned long labelno), 252 default_internal_label) 253 254/* Output label for the constant. */ 255DEFHOOK 256(declare_constant_name, 257 "A target hook to output to the stdio stream @var{file} any text necessary\n\ 258for declaring the name @var{name} of a constant which is being defined. This\n\ 259target hook is responsible for outputting the label definition (perhaps using\n\ 260@code{assemble_label}). The argument @var{exp} is the value of the constant,\n\ 261and @var{size} is the size of the constant in bytes. The @var{name}\n\ 262will be an internal label.\n\ 263\n\ 264The default version of this target hook, define the @var{name} in the\n\ 265usual manner as a label (by means of @code{assemble_label}).\n\ 266\n\ 267You may wish to use @code{ASM_OUTPUT_TYPE_DIRECTIVE} in this target hook.", 268 void, (FILE *file, const char *name, const_tree expr, HOST_WIDE_INT size), 269 default_asm_declare_constant_name) 270 271/* Emit a ttype table reference to a typeinfo object. */ 272DEFHOOK 273(ttype, 274 "This hook is used to output a reference from a frame unwinding table to\n\ 275the type_info object identified by @var{sym}. It should return @code{true}\n\ 276if the reference was output. Returning @code{false} will cause the\n\ 277reference to be output using the normal Dwarf2 routines.", 278 bool, (rtx sym), 279 hook_bool_rtx_false) 280 281/* Emit an assembler directive to set visibility for the symbol 282 associated with the tree decl. */ 283DEFHOOK 284(assemble_visibility, 285 "This target hook is a function to output to @var{asm_out_file} some\n\ 286commands that will make the symbol(s) associated with @var{decl} have\n\ 287hidden, protected or internal visibility as specified by @var{visibility}.", 288 void, (tree decl, int visibility), 289 default_assemble_visibility) 290 291/* Output the assembler code for entry to a function. */ 292DEFHOOK 293(function_prologue, 294 "If defined, a function that outputs the assembler code for entry to a\n\ 295function. The prologue is responsible for setting up the stack frame,\n\ 296initializing the frame pointer register, saving registers that must be\n\ 297saved, and allocating @var{size} additional bytes of storage for the\n\ 298local variables. @var{size} is an integer. @var{file} is a stdio\n\ 299stream to which the assembler code should be output.\n\ 300\n\ 301The label for the beginning of the function need not be output by this\n\ 302macro. That has already been done when the macro is run.\n\ 303\n\ 304@findex regs_ever_live\n\ 305To determine which registers to save, the macro can refer to the array\n\ 306@code{regs_ever_live}: element @var{r} is nonzero if hard register\n\ 307@var{r} is used anywhere within the function. This implies the function\n\ 308prologue should save register @var{r}, provided it is not one of the\n\ 309call-used registers. (@code{TARGET_ASM_FUNCTION_EPILOGUE} must likewise use\n\ 310@code{regs_ever_live}.)\n\ 311\n\ 312On machines that have ``register windows'', the function entry code does\n\ 313not save on the stack the registers that are in the windows, even if\n\ 314they are supposed to be preserved by function calls; instead it takes\n\ 315appropriate steps to ``push'' the register stack, if any non-call-used\n\ 316registers are used in the function.\n\ 317\n\ 318@findex frame_pointer_needed\n\ 319On machines where functions may or may not have frame-pointers, the\n\ 320function entry code must vary accordingly; it must set up the frame\n\ 321pointer if one is wanted, and not otherwise. To determine whether a\n\ 322frame pointer is in wanted, the macro can refer to the variable\n\ 323@code{frame_pointer_needed}. The variable's value will be 1 at run\n\ 324time in a function that needs a frame pointer. @xref{Elimination}.\n\ 325\n\ 326The function entry code is responsible for allocating any stack space\n\ 327required for the function. This stack space consists of the regions\n\ 328listed below. In most cases, these regions are allocated in the\n\ 329order listed, with the last listed region closest to the top of the\n\ 330stack (the lowest address if @code{STACK_GROWS_DOWNWARD} is defined, and\n\ 331the highest address if it is not defined). You can use a different order\n\ 332for a machine if doing so is more convenient or required for\n\ 333compatibility reasons. Except in cases where required by standard\n\ 334or by a debugger, there is no reason why the stack layout used by GCC\n\ 335need agree with that used by other compilers for a machine.", 336 void, (FILE *file, HOST_WIDE_INT size), 337 default_function_pro_epilogue) 338 339/* Output the assembler code for end of prologue. */ 340DEFHOOK 341(function_end_prologue, 342 "If defined, a function that outputs assembler code at the end of a\n\ 343prologue. This should be used when the function prologue is being\n\ 344emitted as RTL, and you have some extra assembler that needs to be\n\ 345emitted. @xref{prologue instruction pattern}.", 346 void, (FILE *file), 347 no_asm_to_stream) 348 349/* Output the assembler code for start of epilogue. */ 350DEFHOOK 351(function_begin_epilogue, 352 "If defined, a function that outputs assembler code at the start of an\n\ 353epilogue. This should be used when the function epilogue is being\n\ 354emitted as RTL, and you have some extra assembler that needs to be\n\ 355emitted. @xref{epilogue instruction pattern}.", 356 void, (FILE *file), 357 no_asm_to_stream) 358 359/* Output the assembler code for function exit. */ 360DEFHOOK 361(function_epilogue, 362 "If defined, a function that outputs the assembler code for exit from a\n\ 363function. The epilogue is responsible for restoring the saved\n\ 364registers and stack pointer to their values when the function was\n\ 365called, and returning control to the caller. This macro takes the\n\ 366same arguments as the macro @code{TARGET_ASM_FUNCTION_PROLOGUE}, and the\n\ 367registers to restore are determined from @code{regs_ever_live} and\n\ 368@code{CALL_USED_REGISTERS} in the same way.\n\ 369\n\ 370On some machines, there is a single instruction that does all the work\n\ 371of returning from the function. On these machines, give that\n\ 372instruction the name @samp{return} and do not define the macro\n\ 373@code{TARGET_ASM_FUNCTION_EPILOGUE} at all.\n\ 374\n\ 375Do not define a pattern named @samp{return} if you want the\n\ 376@code{TARGET_ASM_FUNCTION_EPILOGUE} to be used. If you want the target\n\ 377switches to control whether return instructions or epilogues are used,\n\ 378define a @samp{return} pattern with a validity condition that tests the\n\ 379target switches appropriately. If the @samp{return} pattern's validity\n\ 380condition is false, epilogues will be used.\n\ 381\n\ 382On machines where functions may or may not have frame-pointers, the\n\ 383function exit code must vary accordingly. Sometimes the code for these\n\ 384two cases is completely different. To determine whether a frame pointer\n\ 385is wanted, the macro can refer to the variable\n\ 386@code{frame_pointer_needed}. The variable's value will be 1 when compiling\n\ 387a function that needs a frame pointer.\n\ 388\n\ 389Normally, @code{TARGET_ASM_FUNCTION_PROLOGUE} and\n\ 390@code{TARGET_ASM_FUNCTION_EPILOGUE} must treat leaf functions specially.\n\ 391The C variable @code{current_function_is_leaf} is nonzero for such a\n\ 392function. @xref{Leaf Functions}.\n\ 393\n\ 394On some machines, some functions pop their arguments on exit while\n\ 395others leave that for the caller to do. For example, the 68020 when\n\ 396given @option{-mrtd} pops arguments in functions that take a fixed\n\ 397number of arguments.\n\ 398\n\ 399@findex pops_args\n\ 400@findex crtl->args.pops_args\n\ 401Your definition of the macro @code{RETURN_POPS_ARGS} decides which\n\ 402functions pop their own arguments. @code{TARGET_ASM_FUNCTION_EPILOGUE}\n\ 403needs to know what was decided. The number of bytes of the current\n\ 404function's arguments that this function should pop is available in\n\ 405@code{crtl->args.pops_args}. @xref{Scalar Return}.", 406 void, (FILE *file, HOST_WIDE_INT size), 407 default_function_pro_epilogue) 408 409/* Initialize target-specific sections. */ 410DEFHOOK 411(init_sections, 412 "Define this hook if you need to do something special to set up the\n\ 413@file{varasm.c} sections, or if your target has some special sections\n\ 414of its own that you need to create.\n\ 415\n\ 416GCC calls this hook after processing the command line, but before writing\n\ 417any assembly code, and before calling any of the section-returning hooks\n\ 418described below.", 419 void, (void), 420 hook_void_void) 421 422/* Tell assembler to change to section NAME with attributes FLAGS. 423 If DECL is non-NULL, it is the VAR_DECL or FUNCTION_DECL with 424 which this section is associated. */ 425DEFHOOK 426(named_section, 427 "Output assembly directives to switch to section @var{name}. The section\n\ 428should have attributes as specified by @var{flags}, which is a bit mask\n\ 429of the @code{SECTION_*} flags defined in @file{output.h}. If @var{decl}\n\ 430is non-NULL, it is the @code{VAR_DECL} or @code{FUNCTION_DECL} with which\n\ 431this section is associated.", 432 void, (const char *name, unsigned int flags, tree decl), 433 default_no_named_section) 434 435/* Return preferred text (sub)section for function DECL. 436 Main purpose of this function is to separate cold, normal and hot 437 functions. STARTUP is true when function is known to be used only 438 at startup (from static constructors or it is main()). 439 EXIT is true when function is known to be used only at exit 440 (from static destructors). 441 Return NULL if function should go to default text section. */ 442DEFHOOK 443(function_section, 444 "Return preferred text (sub)section for function @var{decl}.\n\ 445Main purpose of this function is to separate cold, normal and hot\n\ 446functions. @var{startup} is true when function is known to be used only\n\ 447at startup (from static constructors or it is @code{main()}).\n\ 448@var{exit} is true when function is known to be used only at exit\n\ 449(from static destructors).\n\ 450Return NULL if function should go to default text section.", 451 section *, (tree decl, enum node_frequency freq, bool startup, bool exit), 452 default_function_section) 453 454/* Output the assembler code for function exit. */ 455DEFHOOK 456(function_switched_text_sections, 457 "Used by the target to emit any assembler directives or additional\ 458 labels needed when a function is partitioned between different\ 459 sections. Output should be written to @var{file}. The function\ 460 decl is available as @var{decl} and the new section is `cold' if\ 461 @var{new_is_cold} is @code{true}.", 462 void, (FILE *file, tree decl, bool new_is_cold), 463 default_function_switched_text_sections) 464 465/* Return a mask describing how relocations should be treated when 466 selecting sections. Bit 1 should be set if global relocations 467 should be placed in a read-write section; bit 0 should be set if 468 local relocations should be placed in a read-write section. */ 469DEFHOOK 470(reloc_rw_mask, 471 "Return a mask describing how relocations should be treated when\n\ 472selecting sections. Bit 1 should be set if global relocations\n\ 473should be placed in a read-write section; bit 0 should be set if\n\ 474local relocations should be placed in a read-write section.\n\ 475\n\ 476The default version of this function returns 3 when @option{-fpic}\n\ 477is in effect, and 0 otherwise. The hook is typically redefined\n\ 478when the target cannot support (some kinds of) dynamic relocations\n\ 479in read-only sections even in executables.", 480 int, (void), 481 default_reloc_rw_mask) 482 483 /* Return a section for EXP. It may be a DECL or a constant. RELOC 484 is nonzero if runtime relocations must be applied; bit 1 will be 485 set if the runtime relocations require non-local name resolution. 486 ALIGN is the required alignment of the data. */ 487DEFHOOK 488(select_section, 489 "Return the section into which @var{exp} should be placed. You can\n\ 490assume that @var{exp} is either a @code{VAR_DECL} node or a constant of\n\ 491some sort. @var{reloc} indicates whether the initial value of @var{exp}\n\ 492requires link-time relocations. Bit 0 is set when variable contains\n\ 493local relocations only, while bit 1 is set for global relocations.\n\ 494@var{align} is the constant alignment in bits.\n\ 495\n\ 496The default version of this function takes care of putting read-only\n\ 497variables in @code{readonly_data_section}.\n\ 498\n\ 499See also @var{USE_SELECT_SECTION_FOR_FUNCTIONS}.", 500 section *, (tree exp, int reloc, unsigned HOST_WIDE_INT align), 501 default_select_section) 502 503/* Return a section for X. MODE is X's mode and ALIGN is its 504 alignment in bits. */ 505DEFHOOK 506(select_rtx_section, 507 "Return the section into which a constant @var{x}, of mode @var{mode},\n\ 508should be placed. You can assume that @var{x} is some kind of\n\ 509constant in RTL@. The argument @var{mode} is redundant except in the\n\ 510case of a @code{const_int} rtx. @var{align} is the constant alignment\n\ 511in bits.\n\ 512\n\ 513The default version of this function takes care of putting symbolic\n\ 514constants in @code{flag_pic} mode in @code{data_section} and everything\n\ 515else in @code{readonly_data_section}.", 516 section *, (machine_mode mode, rtx x, unsigned HOST_WIDE_INT align), 517 default_select_rtx_section) 518 519/* Select a unique section name for DECL. RELOC is the same as 520 for SELECT_SECTION. */ 521DEFHOOK 522(unique_section, 523 "Build up a unique section name, expressed as a @code{STRING_CST} node,\n\ 524and assign it to @samp{DECL_SECTION_NAME (@var{decl})}.\n\ 525As with @code{TARGET_ASM_SELECT_SECTION}, @var{reloc} indicates whether\n\ 526the initial value of @var{exp} requires link-time relocations.\n\ 527\n\ 528The default version of this function appends the symbol name to the\n\ 529ELF section name that would normally be used for the symbol. For\n\ 530example, the function @code{foo} would be placed in @code{.text.foo}.\n\ 531Whatever the actual target object format, this is often good enough.", 532 void, (tree decl, int reloc), 533 default_unique_section) 534 535/* Return the readonly data section associated with function DECL. */ 536DEFHOOK 537(function_rodata_section, 538 "Return the readonly data section associated with\n\ 539@samp{DECL_SECTION_NAME (@var{decl})}.\n\ 540The default version of this function selects @code{.gnu.linkonce.r.name} if\n\ 541the function's section is @code{.gnu.linkonce.t.name}, @code{.rodata.name}\n\ 542if function is in @code{.text.name}, and the normal readonly-data section\n\ 543otherwise.", 544 section *, (tree decl), 545 default_function_rodata_section) 546 547/* Nonnull if the target wants to override the default ".rodata" prefix 548 for mergeable data sections. */ 549DEFHOOKPOD 550(mergeable_rodata_prefix, 551 "Usually, the compiler uses the prefix @code{\".rodata\"} to construct\n\ 552section names for mergeable constant data. Define this macro to override\n\ 553the string if a different section name should be used.", 554 const char *, ".rodata") 555 556/* Return the section to be used for transactional memory clone tables. */ 557DEFHOOK 558(tm_clone_table_section, 559 "Return the section that should be used for transactional memory clone\ 560 tables.", 561 section *, (void), default_clone_table_section) 562 563/* Output a constructor for a symbol with a given priority. */ 564DEFHOOK 565(constructor, 566 "If defined, a function that outputs assembler code to arrange to call\n\ 567the function referenced by @var{symbol} at initialization time.\n\ 568\n\ 569Assume that @var{symbol} is a @code{SYMBOL_REF} for a function taking\n\ 570no arguments and with no return value. If the target supports initialization\n\ 571priorities, @var{priority} is a value between 0 and @code{MAX_INIT_PRIORITY};\n\ 572otherwise it must be @code{DEFAULT_INIT_PRIORITY}.\n\ 573\n\ 574If this macro is not defined by the target, a suitable default will\n\ 575be chosen if (1) the target supports arbitrary section names, (2) the\n\ 576target defines @code{CTORS_SECTION_ASM_OP}, or (3) @code{USE_COLLECT2}\n\ 577is not defined.", 578 void, (rtx symbol, int priority), NULL) 579 580/* Output a destructor for a symbol with a given priority. */ 581DEFHOOK 582(destructor, 583 "This is like @code{TARGET_ASM_CONSTRUCTOR} but used for termination\n\ 584functions rather than initialization functions.", 585 void, (rtx symbol, int priority), NULL) 586 587/* Output the assembler code for a thunk function. THUNK_DECL is the 588 declaration for the thunk function itself, FUNCTION is the decl for 589 the target function. DELTA is an immediate constant offset to be 590 added to THIS. If VCALL_OFFSET is nonzero, the word at 591 *(*this + vcall_offset) should be added to THIS. */ 592DEFHOOK 593(output_mi_thunk, 594 "A function that outputs the assembler code for a thunk\n\ 595function, used to implement C++ virtual function calls with multiple\n\ 596inheritance. The thunk acts as a wrapper around a virtual function,\n\ 597adjusting the implicit object parameter before handing control off to\n\ 598the real function.\n\ 599\n\ 600First, emit code to add the integer @var{delta} to the location that\n\ 601contains the incoming first argument. Assume that this argument\n\ 602contains a pointer, and is the one used to pass the @code{this} pointer\n\ 603in C++. This is the incoming argument @emph{before} the function prologue,\n\ 604e.g.@: @samp{%o0} on a sparc. The addition must preserve the values of\n\ 605all other incoming arguments.\n\ 606\n\ 607Then, if @var{vcall_offset} is nonzero, an additional adjustment should be\n\ 608made after adding @code{delta}. In particular, if @var{p} is the\n\ 609adjusted pointer, the following adjustment should be made:\n\ 610\n\ 611@smallexample\n\ 612p += (*((ptrdiff_t **)p))[vcall_offset/sizeof(ptrdiff_t)]\n\ 613@end smallexample\n\ 614\n\ 615After the additions, emit code to jump to @var{function}, which is a\n\ 616@code{FUNCTION_DECL}. This is a direct pure jump, not a call, and does\n\ 617not touch the return address. Hence returning from @var{FUNCTION} will\n\ 618return to whoever called the current @samp{thunk}.\n\ 619\n\ 620The effect must be as if @var{function} had been called directly with\n\ 621the adjusted first argument. This macro is responsible for emitting all\n\ 622of the code for a thunk function; @code{TARGET_ASM_FUNCTION_PROLOGUE}\n\ 623and @code{TARGET_ASM_FUNCTION_EPILOGUE} are not invoked.\n\ 624\n\ 625The @var{thunk_fndecl} is redundant. (@var{delta} and @var{function}\n\ 626have already been extracted from it.) It might possibly be useful on\n\ 627some targets, but probably not.\n\ 628\n\ 629If you do not define this macro, the target-independent code in the C++\n\ 630front end will generate a less efficient heavyweight thunk that calls\n\ 631@var{function} instead of jumping to it. The generic approach does\n\ 632not support varargs.", 633 void, (FILE *file, tree thunk_fndecl, HOST_WIDE_INT delta, 634 HOST_WIDE_INT vcall_offset, tree function), 635 NULL) 636 637/* Determine whether output_mi_thunk would succeed. */ 638/* ??? Ideally, this hook would not exist, and success or failure 639 would be returned from output_mi_thunk directly. But there's 640 too much undo-able setup involved in invoking output_mi_thunk. 641 Could be fixed by making output_mi_thunk emit rtl instead of 642 text to the output file. */ 643DEFHOOK 644(can_output_mi_thunk, 645 "A function that returns true if TARGET_ASM_OUTPUT_MI_THUNK would be able\n\ 646to output the assembler code for the thunk function specified by the\n\ 647arguments it is passed, and false otherwise. In the latter case, the\n\ 648generic approach will be used by the C++ front end, with the limitations\n\ 649previously exposed.", 650 bool, (const_tree thunk_fndecl, HOST_WIDE_INT delta, 651 HOST_WIDE_INT vcall_offset, const_tree function), 652 hook_bool_const_tree_hwi_hwi_const_tree_false) 653 654/* Output any boilerplate text needed at the beginning of a 655 translation unit. */ 656DEFHOOK 657(file_start, 658 "Output to @code{asm_out_file} any text which the assembler expects to\n\ 659find at the beginning of a file. The default behavior is controlled\n\ 660by two flags, documented below. Unless your target's assembler is\n\ 661quite unusual, if you override the default, you should call\n\ 662@code{default_file_start} at some point in your target hook. This\n\ 663lets other target files rely on these variables.", 664 void, (void), 665 default_file_start) 666 667/* Output any boilerplate text needed at the end of a translation unit. */ 668DEFHOOK 669(file_end, 670 "Output to @code{asm_out_file} any text which the assembler expects\n\ 671to find at the end of a file. The default is to output nothing.", 672 void, (void), 673 hook_void_void) 674 675/* Output any boilerplate text needed at the beginning of an 676 LTO output stream. */ 677DEFHOOK 678(lto_start, 679 "Output to @code{asm_out_file} any text which the assembler expects\n\ 680to find at the start of an LTO section. The default is to output\n\ 681nothing.", 682 void, (void), 683 hook_void_void) 684 685/* Output any boilerplate text needed at the end of an 686 LTO output stream. */ 687DEFHOOK 688(lto_end, 689 "Output to @code{asm_out_file} any text which the assembler expects\n\ 690to find at the end of an LTO section. The default is to output\n\ 691nothing.", 692 void, (void), 693 hook_void_void) 694 695/* Output any boilerplace text needed at the end of a 696 translation unit before debug and unwind info is emitted. */ 697DEFHOOK 698(code_end, 699 "Output to @code{asm_out_file} any text which is needed before emitting\n\ 700unwind info and debug info at the end of a file. Some targets emit\n\ 701here PIC setup thunks that cannot be emitted at the end of file,\n\ 702because they couldn't have unwind info then. The default is to output\n\ 703nothing.", 704 void, (void), 705 hook_void_void) 706 707/* Output an assembler pseudo-op to declare a library function name 708 external. */ 709DEFHOOK 710(external_libcall, 711 "This target hook is a function to output to @var{asm_out_file} an assembler\n\ 712pseudo-op to declare a library function name external. The name of the\n\ 713library function is given by @var{symref}, which is a @code{symbol_ref}.", 714 void, (rtx symref), 715 default_external_libcall) 716 717/* Output an assembler directive to mark decl live. This instructs 718 linker to not dead code strip this symbol. */ 719DEFHOOK 720(mark_decl_preserved, 721 "This target hook is a function to output to @var{asm_out_file} an assembler\n\ 722directive to annotate @var{symbol} as used. The Darwin target uses the\n\ 723.no_dead_code_strip directive.", 724 void, (const char *symbol), 725 hook_void_constcharptr) 726 727/* Output a record of the command line switches that have been passed. */ 728DEFHOOK 729(record_gcc_switches, 730 "Provides the target with the ability to record the gcc command line\n\ 731switches that have been passed to the compiler, and options that are\n\ 732enabled. The @var{type} argument specifies what is being recorded.\n\ 733It can take the following values:\n\ 734\n\ 735@table @gcctabopt\n\ 736@item SWITCH_TYPE_PASSED\n\ 737@var{text} is a command line switch that has been set by the user.\n\ 738\n\ 739@item SWITCH_TYPE_ENABLED\n\ 740@var{text} is an option which has been enabled. This might be as a\n\ 741direct result of a command line switch, or because it is enabled by\n\ 742default or because it has been enabled as a side effect of a different\n\ 743command line switch. For example, the @option{-O2} switch enables\n\ 744various different individual optimization passes.\n\ 745\n\ 746@item SWITCH_TYPE_DESCRIPTIVE\n\ 747@var{text} is either NULL or some descriptive text which should be\n\ 748ignored. If @var{text} is NULL then it is being used to warn the\n\ 749target hook that either recording is starting or ending. The first\n\ 750time @var{type} is SWITCH_TYPE_DESCRIPTIVE and @var{text} is NULL, the\n\ 751warning is for start up and the second time the warning is for\n\ 752wind down. This feature is to allow the target hook to make any\n\ 753necessary preparations before it starts to record switches and to\n\ 754perform any necessary tidying up after it has finished recording\n\ 755switches.\n\ 756\n\ 757@item SWITCH_TYPE_LINE_START\n\ 758This option can be ignored by this target hook.\n\ 759\n\ 760@item SWITCH_TYPE_LINE_END\n\ 761This option can be ignored by this target hook.\n\ 762@end table\n\ 763\n\ 764The hook's return value must be zero. Other return values may be\n\ 765supported in the future.\n\ 766\n\ 767By default this hook is set to NULL, but an example implementation is\n\ 768provided for ELF based targets. Called @var{elf_record_gcc_switches},\n\ 769it records the switches as ASCII text inside a new, string mergeable\n\ 770section in the assembler output file. The name of the new section is\n\ 771provided by the @code{TARGET_ASM_RECORD_GCC_SWITCHES_SECTION} target\n\ 772hook.", 773 int, (print_switch_type type, const char *text), 774 NULL) 775 776/* The name of the section that the example ELF implementation of 777 record_gcc_switches will use to store the information. Target 778 specific versions of record_gcc_switches may or may not use 779 this information. */ 780DEFHOOKPOD 781(record_gcc_switches_section, 782 "This is the name of the section that will be created by the example\n\ 783ELF implementation of the @code{TARGET_ASM_RECORD_GCC_SWITCHES} target\n\ 784hook.", 785 const char *, ".GCC.command.line") 786 787/* Output the definition of a section anchor. */ 788DEFHOOK 789(output_anchor, 790 "Write the assembly code to define section anchor @var{x}, which is a\n\ 791@code{SYMBOL_REF} for which @samp{SYMBOL_REF_ANCHOR_P (@var{x})} is true.\n\ 792The hook is called with the assembly output position set to the beginning\n\ 793of @code{SYMBOL_REF_BLOCK (@var{x})}.\n\ 794\n\ 795If @code{ASM_OUTPUT_DEF} is available, the hook's default definition uses\n\ 796it to define the symbol as @samp{. + SYMBOL_REF_BLOCK_OFFSET (@var{x})}.\n\ 797If @code{ASM_OUTPUT_DEF} is not available, the hook's default definition\n\ 798is @code{NULL}, which disables the use of section anchors altogether.", 799 void, (rtx x), 800 default_asm_output_anchor) 801 802DEFHOOK 803(output_ident, 804 "Output a string based on @var{name}, suitable for the @samp{#ident} \ 805 directive, or the equivalent directive or pragma in non-C-family languages. \ 806 If this hook is not defined, nothing is output for the @samp{#ident} \ 807 directive.", 808 void, (const char *name), 809 hook_void_constcharptr) 810 811/* Output a DTP-relative reference to a TLS symbol. */ 812DEFHOOK 813(output_dwarf_dtprel, 814 "If defined, this target hook is a function which outputs a DTP-relative\n\ 815reference to the given TLS symbol of the specified size.", 816 void, (FILE *file, int size, rtx x), 817 NULL) 818 819/* Some target machines need to postscan each insn after it is output. */ 820DEFHOOK 821(final_postscan_insn, 822 "If defined, this target hook is a function which is executed just after the\n\ 823output of assembler code for @var{insn}, to change the mode of the assembler\n\ 824if necessary.\n\ 825\n\ 826Here the argument @var{opvec} is the vector containing the operands\n\ 827extracted from @var{insn}, and @var{noperands} is the number of\n\ 828elements of the vector which contain meaningful data for this insn.\n\ 829The contents of this vector are what was used to convert the insn\n\ 830template into assembler code, so you can change the assembler mode\n\ 831by checking the contents of the vector.", 832 void, (FILE *file, rtx_insn *insn, rtx *opvec, int noperands), 833 NULL) 834 835/* Emit the trampoline template. This hook may be NULL. */ 836DEFHOOK 837(trampoline_template, 838 "This hook is called by @code{assemble_trampoline_template} to output,\n\ 839on the stream @var{f}, assembler code for a block of data that contains\n\ 840the constant parts of a trampoline. This code should not include a\n\ 841label---the label is taken care of automatically.\n\ 842\n\ 843If you do not define this hook, it means no template is needed\n\ 844for the target. Do not define this hook on systems where the block move\n\ 845code to copy the trampoline into place would be larger than the code\n\ 846to generate it on the spot.", 847 void, (FILE *f), 848 NULL) 849 850DEFHOOK 851(output_source_filename, 852 "Output COFF information or DWARF debugging information which indicates\ 853 that filename @var{name} is the current source file to the stdio\ 854 stream @var{file}.\n\ 855 \n\ 856 This target hook need not be defined if the standard form of output\ 857 for the file format in use is appropriate.", 858 void ,(FILE *file, const char *name), 859 default_asm_output_source_filename) 860 861DEFHOOK 862(output_addr_const_extra, 863 "A target hook to recognize @var{rtx} patterns that @code{output_addr_const}\n\ 864can't deal with, and output assembly code to @var{file} corresponding to\n\ 865the pattern @var{x}. This may be used to allow machine-dependent\n\ 866@code{UNSPEC}s to appear within constants.\n\ 867\n\ 868If target hook fails to recognize a pattern, it must return @code{false},\n\ 869so that a standard error message is printed. If it prints an error message\n\ 870itself, by calling, for example, @code{output_operand_lossage}, it may just\n\ 871return @code{true}.", 872 bool, (FILE *file, rtx x), 873 hook_bool_FILEptr_rtx_false) 874 875/* ??? The TARGET_PRINT_OPERAND* hooks are part of the asm_out struct, 876 even though that is not reflected in the macro name to override their 877 initializers. */ 878#undef HOOK_PREFIX 879#define HOOK_PREFIX "TARGET_" 880 881/* Emit a machine-specific insn operand. */ 882/* ??? tm.texi only documents the old macro PRINT_OPERAND, 883 not this hook, and uses a different name for the argument FILE. */ 884DEFHOOK_UNDOC 885(print_operand, 886 "", 887 void, (FILE *file, rtx x, int code), 888 default_print_operand) 889 890/* Emit a machine-specific memory address. */ 891/* ??? tm.texi only documents the old macro PRINT_OPERAND_ADDRESS, 892 not this hook, and uses different argument names. */ 893DEFHOOK_UNDOC 894(print_operand_address, 895 "", 896 void, (FILE *file, machine_mode mode, rtx addr), 897 default_print_operand_address) 898 899/* Determine whether CODE is a valid punctuation character for the 900 `print_operand' hook. */ 901/* ??? tm.texi only documents the old macro PRINT_OPERAND_PUNCT_VALID_P, 902 not this hook. */ 903DEFHOOK_UNDOC 904(print_operand_punct_valid_p, 905 "", 906 bool ,(unsigned char code), 907 default_print_operand_punct_valid_p) 908 909/* Given a symbol name, perform same mangling as assemble_name and 910 ASM_OUTPUT_LABELREF, returning result as an IDENTIFIER_NODE. */ 911DEFHOOK 912(mangle_assembler_name, 913 "Given a symbol @var{name}, perform same mangling as @code{varasm.c}'s\ 914 @code{assemble_name}, but in memory rather than to a file stream, returning\ 915 result as an @code{IDENTIFIER_NODE}. Required for correct LTO symtabs. The\ 916 default implementation calls the @code{TARGET_STRIP_NAME_ENCODING} hook and\ 917 then prepends the @code{USER_LABEL_PREFIX}, if any.", 918 tree, (const char *name), 919 default_mangle_assembler_name) 920 921HOOK_VECTOR_END (asm_out) 922 923/* Functions relating to instruction scheduling. All of these 924 default to null pointers, which haifa-sched.c looks for and handles. */ 925#undef HOOK_PREFIX 926#define HOOK_PREFIX "TARGET_SCHED_" 927HOOK_VECTOR (TARGET_SCHED, sched) 928 929/* Given the current cost, COST, of an insn, INSN, calculate and 930 return a new cost based on its relationship to DEP_INSN through 931 the dependence LINK. The default is to make no adjustment. */ 932DEFHOOK 933(adjust_cost, 934 "This function corrects the value of @var{cost} based on the\n\ 935relationship between @var{insn} and @var{dep_insn} through the\n\ 936dependence @var{link}. It should return the new value. The default\n\ 937is to make no adjustment to @var{cost}. This can be used for example\n\ 938to specify to the scheduler using the traditional pipeline description\n\ 939that an output- or anti-dependence does not incur the same cost as a\n\ 940data-dependence. If the scheduler using the automaton based pipeline\n\ 941description, the cost of anti-dependence is zero and the cost of\n\ 942output-dependence is maximum of one and the difference of latency\n\ 943times of the first and the second insns. If these values are not\n\ 944acceptable, you could use the hook to modify them too. See also\n\ 945@pxref{Processor pipeline description}.", 946 int, (rtx_insn *insn, rtx link, rtx_insn *dep_insn, int cost), NULL) 947 948/* Adjust the priority of an insn as you see fit. Returns the new priority. */ 949DEFHOOK 950(adjust_priority, 951 "This hook adjusts the integer scheduling priority @var{priority} of\n\ 952@var{insn}. It should return the new priority. Increase the priority to\n\ 953execute @var{insn} earlier, reduce the priority to execute @var{insn}\n\ 954later. Do not define this hook if you do not need to adjust the\n\ 955scheduling priorities of insns.", 956 int, (rtx_insn *insn, int priority), NULL) 957 958/* Function which returns the maximum number of insns that can be 959 scheduled in the same machine cycle. This must be constant 960 over an entire compilation. The default is 1. */ 961DEFHOOK 962(issue_rate, 963 "This hook returns the maximum number of instructions that can ever\n\ 964issue at the same time on the target machine. The default is one.\n\ 965Although the insn scheduler can define itself the possibility of issue\n\ 966an insn on the same cycle, the value can serve as an additional\n\ 967constraint to issue insns on the same simulated processor cycle (see\n\ 968hooks @samp{TARGET_SCHED_REORDER} and @samp{TARGET_SCHED_REORDER2}).\n\ 969This value must be constant over the entire compilation. If you need\n\ 970it to vary depending on what the instructions are, you must use\n\ 971@samp{TARGET_SCHED_VARIABLE_ISSUE}.", 972 int, (void), NULL) 973 974/* Calculate how much this insn affects how many more insns we 975 can emit this cycle. Default is they all cost the same. */ 976DEFHOOK 977(variable_issue, 978 "This hook is executed by the scheduler after it has scheduled an insn\n\ 979from the ready list. It should return the number of insns which can\n\ 980still be issued in the current cycle. The default is\n\ 981@samp{@w{@var{more} - 1}} for insns other than @code{CLOBBER} and\n\ 982@code{USE}, which normally are not counted against the issue rate.\n\ 983You should define this hook if some insns take more machine resources\n\ 984than others, so that fewer insns can follow them in the same cycle.\n\ 985@var{file} is either a null pointer, or a stdio stream to write any\n\ 986debug output to. @var{verbose} is the verbose level provided by\n\ 987@option{-fsched-verbose-@var{n}}. @var{insn} is the instruction that\n\ 988was scheduled.", 989 int, (FILE *file, int verbose, rtx_insn *insn, int more), NULL) 990 991/* Initialize machine-dependent scheduling code. */ 992DEFHOOK 993(init, 994 "This hook is executed by the scheduler at the beginning of each block of\n\ 995instructions that are to be scheduled. @var{file} is either a null\n\ 996pointer, or a stdio stream to write any debug output to. @var{verbose}\n\ 997is the verbose level provided by @option{-fsched-verbose-@var{n}}.\n\ 998@var{max_ready} is the maximum number of insns in the current scheduling\n\ 999region that can be live at the same time. This can be used to allocate\n\ 1000scratch space if it is needed, e.g.@: by @samp{TARGET_SCHED_REORDER}.", 1001 void, (FILE *file, int verbose, int max_ready), NULL) 1002 1003/* Finalize machine-dependent scheduling code. */ 1004DEFHOOK 1005(finish, 1006 "This hook is executed by the scheduler at the end of each block of\n\ 1007instructions that are to be scheduled. It can be used to perform\n\ 1008cleanup of any actions done by the other scheduling hooks. @var{file}\n\ 1009is either a null pointer, or a stdio stream to write any debug output\n\ 1010to. @var{verbose} is the verbose level provided by\n\ 1011@option{-fsched-verbose-@var{n}}.", 1012 void, (FILE *file, int verbose), NULL) 1013 1014 /* Initialize machine-dependent function wide scheduling code. */ 1015DEFHOOK 1016(init_global, 1017 "This hook is executed by the scheduler after function level initializations.\n\ 1018@var{file} is either a null pointer, or a stdio stream to write any debug output to.\n\ 1019@var{verbose} is the verbose level provided by @option{-fsched-verbose-@var{n}}.\n\ 1020@var{old_max_uid} is the maximum insn uid when scheduling begins.", 1021 void, (FILE *file, int verbose, int old_max_uid), NULL) 1022 1023/* Finalize machine-dependent function wide scheduling code. */ 1024DEFHOOK 1025(finish_global, 1026 "This is the cleanup hook corresponding to @code{TARGET_SCHED_INIT_GLOBAL}.\n\ 1027@var{file} is either a null pointer, or a stdio stream to write any debug output to.\n\ 1028@var{verbose} is the verbose level provided by @option{-fsched-verbose-@var{n}}.", 1029 void, (FILE *file, int verbose), NULL) 1030 1031/* Reorder insns in a machine-dependent fashion, in two different 1032 places. Default does nothing. */ 1033DEFHOOK 1034(reorder, 1035 "This hook is executed by the scheduler after it has scheduled the ready\n\ 1036list, to allow the machine description to reorder it (for example to\n\ 1037combine two small instructions together on @samp{VLIW} machines).\n\ 1038@var{file} is either a null pointer, or a stdio stream to write any\n\ 1039debug output to. @var{verbose} is the verbose level provided by\n\ 1040@option{-fsched-verbose-@var{n}}. @var{ready} is a pointer to the ready\n\ 1041list of instructions that are ready to be scheduled. @var{n_readyp} is\n\ 1042a pointer to the number of elements in the ready list. The scheduler\n\ 1043reads the ready list in reverse order, starting with\n\ 1044@var{ready}[@var{*n_readyp} @minus{} 1] and going to @var{ready}[0]. @var{clock}\n\ 1045is the timer tick of the scheduler. You may modify the ready list and\n\ 1046the number of ready insns. The return value is the number of insns that\n\ 1047can issue this cycle; normally this is just @code{issue_rate}. See also\n\ 1048@samp{TARGET_SCHED_REORDER2}.", 1049 int, (FILE *file, int verbose, rtx_insn **ready, int *n_readyp, int clock), NULL) 1050 1051DEFHOOK 1052(reorder2, 1053 "Like @samp{TARGET_SCHED_REORDER}, but called at a different time. That\n\ 1054function is called whenever the scheduler starts a new cycle. This one\n\ 1055is called once per iteration over a cycle, immediately after\n\ 1056@samp{TARGET_SCHED_VARIABLE_ISSUE}; it can reorder the ready list and\n\ 1057return the number of insns to be scheduled in the same cycle. Defining\n\ 1058this hook can be useful if there are frequent situations where\n\ 1059scheduling one insn causes other insns to become ready in the same\n\ 1060cycle. These other insns can then be taken into account properly.", 1061 int, (FILE *file, int verbose, rtx_insn **ready, int *n_readyp, int clock), NULL) 1062 1063DEFHOOK 1064(macro_fusion_p, 1065 "This hook is used to check whether target platform supports macro fusion.", 1066 bool, (void), NULL) 1067 1068DEFHOOK 1069(macro_fusion_pair_p, 1070 "This hook is used to check whether two insns should be macro fused for\n\ 1071a target microarchitecture. If this hook returns true for the given insn pair\n\ 1072(@var{prev} and @var{curr}), the scheduler will put them into a sched\n\ 1073group, and they will not be scheduled apart. The two insns will be either\n\ 1074two SET insns or a compare and a conditional jump and this hook should\n\ 1075validate any dependencies needed to fuse the two insns together.", 1076 bool, (rtx_insn *prev, rtx_insn *curr), NULL) 1077 1078/* The following member value is a pointer to a function called 1079 after evaluation forward dependencies of insns in chain given 1080 by two parameter values (head and tail correspondingly). */ 1081DEFHOOK 1082(dependencies_evaluation_hook, 1083 "This hook is called after evaluation forward dependencies of insns in\n\ 1084chain given by two parameter values (@var{head} and @var{tail}\n\ 1085correspondingly) but before insns scheduling of the insn chain. For\n\ 1086example, it can be used for better insn classification if it requires\n\ 1087analysis of dependencies. This hook can use backward and forward\n\ 1088dependencies of the insn scheduler because they are already\n\ 1089calculated.", 1090 void, (rtx_insn *head, rtx_insn *tail), NULL) 1091 1092/* The values of the following four members are pointers to functions 1093 used to simplify the automaton descriptions. dfa_pre_cycle_insn and 1094 dfa_post_cycle_insn give functions returning insns which are used to 1095 change the pipeline hazard recognizer state when the new simulated 1096 processor cycle correspondingly starts and finishes. The function 1097 defined by init_dfa_pre_cycle_insn and init_dfa_post_cycle_insn are 1098 used to initialize the corresponding insns. The default values of 1099 the members result in not changing the automaton state when the 1100 new simulated processor cycle correspondingly starts and finishes. */ 1101 1102DEFHOOK 1103(init_dfa_pre_cycle_insn, 1104 "The hook can be used to initialize data used by the previous hook.", 1105 void, (void), NULL) 1106 1107DEFHOOK 1108(dfa_pre_cycle_insn, 1109 "The hook returns an RTL insn. The automaton state used in the\n\ 1110pipeline hazard recognizer is changed as if the insn were scheduled\n\ 1111when the new simulated processor cycle starts. Usage of the hook may\n\ 1112simplify the automaton pipeline description for some @acronym{VLIW}\n\ 1113processors. If the hook is defined, it is used only for the automaton\n\ 1114based pipeline description. The default is not to change the state\n\ 1115when the new simulated processor cycle starts.", 1116 rtx, (void), NULL) 1117 1118DEFHOOK 1119(init_dfa_post_cycle_insn, 1120 "The hook is analogous to @samp{TARGET_SCHED_INIT_DFA_PRE_CYCLE_INSN} but\n\ 1121used to initialize data used by the previous hook.", 1122 void, (void), NULL) 1123 1124DEFHOOK 1125(dfa_post_cycle_insn, 1126 "The hook is analogous to @samp{TARGET_SCHED_DFA_PRE_CYCLE_INSN} but used\n\ 1127to changed the state as if the insn were scheduled when the new\n\ 1128simulated processor cycle finishes.", 1129 rtx_insn *, (void), NULL) 1130 1131/* The values of the following two members are pointers to 1132 functions used to simplify the automaton descriptions. 1133 dfa_pre_advance_cycle and dfa_post_advance_cycle are getting called 1134 immediately before and after cycle is advanced. */ 1135 1136DEFHOOK 1137(dfa_pre_advance_cycle, 1138 "The hook to notify target that the current simulated cycle is about to finish.\n\ 1139The hook is analogous to @samp{TARGET_SCHED_DFA_PRE_CYCLE_INSN} but used\n\ 1140to change the state in more complicated situations - e.g., when advancing\n\ 1141state on a single insn is not enough.", 1142 void, (void), NULL) 1143 1144DEFHOOK 1145(dfa_post_advance_cycle, 1146 "The hook to notify target that new simulated cycle has just started.\n\ 1147The hook is analogous to @samp{TARGET_SCHED_DFA_POST_CYCLE_INSN} but used\n\ 1148to change the state in more complicated situations - e.g., when advancing\n\ 1149state on a single insn is not enough.", 1150 void, (void), NULL) 1151 1152/* The following member value is a pointer to a function returning value 1153 which defines how many insns in queue `ready' will we try for 1154 multi-pass scheduling. If the member value is nonzero and the 1155 function returns positive value, the DFA based scheduler will make 1156 multi-pass scheduling for the first cycle. In other words, we will 1157 try to choose ready insn which permits to start maximum number of 1158 insns on the same cycle. */ 1159DEFHOOK 1160(first_cycle_multipass_dfa_lookahead, 1161 "This hook controls better choosing an insn from the ready insn queue\n\ 1162for the @acronym{DFA}-based insn scheduler. Usually the scheduler\n\ 1163chooses the first insn from the queue. If the hook returns a positive\n\ 1164value, an additional scheduler code tries all permutations of\n\ 1165@samp{TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD ()}\n\ 1166subsequent ready insns to choose an insn whose issue will result in\n\ 1167maximal number of issued insns on the same cycle. For the\n\ 1168@acronym{VLIW} processor, the code could actually solve the problem of\n\ 1169packing simple insns into the @acronym{VLIW} insn. Of course, if the\n\ 1170rules of @acronym{VLIW} packing are described in the automaton.\n\ 1171\n\ 1172This code also could be used for superscalar @acronym{RISC}\n\ 1173processors. Let us consider a superscalar @acronym{RISC} processor\n\ 1174with 3 pipelines. Some insns can be executed in pipelines @var{A} or\n\ 1175@var{B}, some insns can be executed only in pipelines @var{B} or\n\ 1176@var{C}, and one insn can be executed in pipeline @var{B}. The\n\ 1177processor may issue the 1st insn into @var{A} and the 2nd one into\n\ 1178@var{B}. In this case, the 3rd insn will wait for freeing @var{B}\n\ 1179until the next cycle. If the scheduler issues the 3rd insn the first,\n\ 1180the processor could issue all 3 insns per cycle.\n\ 1181\n\ 1182Actually this code demonstrates advantages of the automaton based\n\ 1183pipeline hazard recognizer. We try quickly and easy many insn\n\ 1184schedules to choose the best one.\n\ 1185\n\ 1186The default is no multipass scheduling.", 1187 int, (void), NULL) 1188 1189/* The following member value is pointer to a function controlling 1190 what insns from the ready insn queue will be considered for the 1191 multipass insn scheduling. If the hook returns zero for insn 1192 passed as the parameter, the insn will be not chosen to be issued. */ 1193DEFHOOK 1194(first_cycle_multipass_dfa_lookahead_guard, 1195 "\n\ 1196This hook controls what insns from the ready insn queue will be\n\ 1197considered for the multipass insn scheduling. If the hook returns\n\ 1198zero for @var{insn}, the insn will be considered in multipass scheduling.\n\ 1199Positive return values will remove @var{insn} from consideration on\n\ 1200the current round of multipass scheduling.\n\ 1201Negative return values will remove @var{insn} from consideration for given\n\ 1202number of cycles.\n\ 1203Backends should be careful about returning non-zero for highest priority\n\ 1204instruction at position 0 in the ready list. @var{ready_index} is passed\n\ 1205to allow backends make correct judgements.\n\ 1206\n\ 1207The default is that any ready insns can be chosen to be issued.", 1208 int, (rtx_insn *insn, int ready_index), NULL) 1209 1210/* This hook prepares the target for a new round of multipass 1211 scheduling. 1212 DATA is a pointer to target-specific data used for multipass scheduling. 1213 READY_TRY and N_READY represent the current state of search in the 1214 optimization space. The target can filter out instructions that 1215 should not be tried during current round by setting corresponding 1216 elements in READY_TRY to non-zero. 1217 FIRST_CYCLE_INSN_P is true if this is the first round of multipass 1218 scheduling on current cycle. */ 1219DEFHOOK 1220(first_cycle_multipass_begin, 1221 "This hook prepares the target backend for a new round of multipass\n\ 1222scheduling.", 1223 void, (void *data, signed char *ready_try, int n_ready, bool first_cycle_insn_p), 1224 NULL) 1225 1226/* This hook is called when multipass scheduling evaluates instruction INSN. 1227 DATA is a pointer to target-specific data that can be used to record effects 1228 of INSN on CPU that are not described in DFA. 1229 READY_TRY and N_READY represent the current state of search in the 1230 optimization space. The target can filter out instructions that 1231 should not be tried after issuing INSN by setting corresponding 1232 elements in READY_TRY to non-zero. 1233 INSN is the instruction being evaluated. 1234 PREV_DATA is a pointer to target-specific data corresponding 1235 to a state before issuing INSN. */ 1236DEFHOOK 1237(first_cycle_multipass_issue, 1238 "This hook is called when multipass scheduling evaluates instruction INSN.", 1239 void, (void *data, signed char *ready_try, int n_ready, rtx_insn *insn, 1240 const void *prev_data), NULL) 1241 1242/* This hook is called when multipass scheduling backtracks from evaluation of 1243 instruction corresponding to DATA. 1244 DATA is a pointer to target-specific data that stores the effects 1245 of instruction from which the algorithm backtracks on CPU that are not 1246 described in DFA. 1247 READY_TRY and N_READY represent the current state of search in the 1248 optimization space. The target can filter out instructions that 1249 should not be tried after issuing INSN by setting corresponding 1250 elements in READY_TRY to non-zero. */ 1251DEFHOOK 1252(first_cycle_multipass_backtrack, 1253 "This is called when multipass scheduling backtracks from evaluation of\n\ 1254an instruction.", 1255 void, (const void *data, signed char *ready_try, int n_ready), NULL) 1256 1257/* This hook notifies the target about the result of the concluded current 1258 round of multipass scheduling. 1259 DATA is a pointer. 1260 If DATA is non-NULL it points to target-specific data used for multipass 1261 scheduling which corresponds to instruction at the start of the chain of 1262 the winning solution. DATA is NULL when multipass scheduling cannot find 1263 a good enough solution on current cycle and decides to retry later, 1264 usually after advancing the cycle count. */ 1265DEFHOOK 1266(first_cycle_multipass_end, 1267 "This hook notifies the target about the result of the concluded current\n\ 1268round of multipass scheduling.", 1269 void, (const void *data), NULL) 1270 1271/* This hook is called to initialize target-specific data for multipass 1272 scheduling after it has been allocated. 1273 DATA is a pointer to target-specific data that stores the effects 1274 of instruction from which the algorithm backtracks on CPU that are not 1275 described in DFA. */ 1276DEFHOOK 1277(first_cycle_multipass_init, 1278 "This hook initializes target-specific data used in multipass scheduling.", 1279 void, (void *data), NULL) 1280 1281/* This hook is called to finalize target-specific data for multipass 1282 scheduling before it is deallocated. 1283 DATA is a pointer to target-specific data that stores the effects 1284 of instruction from which the algorithm backtracks on CPU that are not 1285 described in DFA. */ 1286DEFHOOK 1287(first_cycle_multipass_fini, 1288 "This hook finalizes target-specific data used in multipass scheduling.", 1289 void, (void *data), NULL) 1290 1291/* The following member value is pointer to a function called by 1292 the insn scheduler before issuing insn passed as the third 1293 parameter on given cycle. If the hook returns nonzero, the 1294 insn is not issued on given processors cycle. Instead of that, 1295 the processor cycle is advanced. If the value passed through 1296 the last parameter is zero, the insn ready queue is not sorted 1297 on the new cycle start as usually. The first parameter passes 1298 file for debugging output. The second one passes the scheduler 1299 verbose level of the debugging output. The forth and the fifth 1300 parameter values are correspondingly processor cycle on which 1301 the previous insn has been issued and the current processor cycle. */ 1302DEFHOOK 1303(dfa_new_cycle, 1304 "This hook is called by the insn scheduler before issuing @var{insn}\n\ 1305on cycle @var{clock}. If the hook returns nonzero,\n\ 1306@var{insn} is not issued on this processor cycle. Instead,\n\ 1307the processor cycle is advanced. If *@var{sort_p}\n\ 1308is zero, the insn ready queue is not sorted on the new cycle\n\ 1309start as usually. @var{dump} and @var{verbose} specify the file and\n\ 1310verbosity level to use for debugging output.\n\ 1311@var{last_clock} and @var{clock} are, respectively, the\n\ 1312processor cycle on which the previous insn has been issued,\n\ 1313and the current processor cycle.", 1314 int, (FILE *dump, int verbose, rtx_insn *insn, int last_clock, 1315 int clock, int *sort_p), 1316 NULL) 1317 1318/* The following member value is a pointer to a function called by the 1319 insn scheduler. It should return true if there exists a dependence 1320 which is considered costly by the target, between the insn 1321 DEP_PRO (&_DEP), and the insn DEP_CON (&_DEP). The first parameter is 1322 the dep that represents the dependence between the two insns. The 1323 second argument is the cost of the dependence as estimated by 1324 the scheduler. The last argument is the distance in cycles 1325 between the already scheduled insn (first parameter) and the 1326 second insn (second parameter). */ 1327DEFHOOK 1328(is_costly_dependence, 1329 "This hook is used to define which dependences are considered costly by\n\ 1330the target, so costly that it is not advisable to schedule the insns that\n\ 1331are involved in the dependence too close to one another. The parameters\n\ 1332to this hook are as follows: The first parameter @var{_dep} is the dependence\n\ 1333being evaluated. The second parameter @var{cost} is the cost of the\n\ 1334dependence as estimated by the scheduler, and the third\n\ 1335parameter @var{distance} is the distance in cycles between the two insns.\n\ 1336The hook returns @code{true} if considering the distance between the two\n\ 1337insns the dependence between them is considered costly by the target,\n\ 1338and @code{false} otherwise.\n\ 1339\n\ 1340Defining this hook can be useful in multiple-issue out-of-order machines,\n\ 1341where (a) it's practically hopeless to predict the actual data/resource\n\ 1342delays, however: (b) there's a better chance to predict the actual grouping\n\ 1343that will be formed, and (c) correctly emulating the grouping can be very\n\ 1344important. In such targets one may want to allow issuing dependent insns\n\ 1345closer to one another---i.e., closer than the dependence distance; however,\n\ 1346not in cases of ``costly dependences'', which this hooks allows to define.", 1347 bool, (struct _dep *_dep, int cost, int distance), NULL) 1348 1349DEFHOOK_UNDOC 1350(adjust_cost_2, 1351 "Given the current cost, @var{cost}, of an insn, @var{insn}, calculate and\ 1352 return a new cost based on its relationship to @var{dep_insn} through the\ 1353 dependence of weakness @var{dw}. The default is to make no adjustment.", 1354 int, (rtx_insn *insn, int dep_type1, rtx_insn *dep_insn, int cost, 1355 unsigned int dw), 1356 NULL) 1357 1358/* The following member value is a pointer to a function called 1359 by the insn scheduler. This hook is called to notify the backend 1360 that new instructions were emitted. */ 1361DEFHOOK 1362(h_i_d_extended, 1363 "This hook is called by the insn scheduler after emitting a new instruction to\n\ 1364the instruction stream. The hook notifies a target backend to extend its\n\ 1365per instruction data structures.", 1366 void, (void), NULL) 1367 1368/* Next 5 functions are for multi-point scheduling. */ 1369 1370/* Allocate memory for scheduler context. */ 1371DEFHOOK 1372(alloc_sched_context, 1373 "Return a pointer to a store large enough to hold target scheduling context.", 1374 void *, (void), NULL) 1375 1376/* Fills the context from the local machine scheduler context. */ 1377DEFHOOK 1378(init_sched_context, 1379 "Initialize store pointed to by @var{tc} to hold target scheduling context.\n\ 1380It @var{clean_p} is true then initialize @var{tc} as if scheduler is at the\n\ 1381beginning of the block. Otherwise, copy the current context into @var{tc}.", 1382 void, (void *tc, bool clean_p), NULL) 1383 1384/* Sets local machine scheduler context to a saved value. */ 1385DEFHOOK 1386(set_sched_context, 1387 "Copy target scheduling context pointed to by @var{tc} to the current context.", 1388 void, (void *tc), NULL) 1389 1390/* Clears a scheduler context so it becomes like after init. */ 1391DEFHOOK 1392(clear_sched_context, 1393 "Deallocate internal data in target scheduling context pointed to by @var{tc}.", 1394 void, (void *tc), NULL) 1395 1396/* Frees the scheduler context. */ 1397DEFHOOK 1398(free_sched_context, 1399 "Deallocate a store for target scheduling context pointed to by @var{tc}.", 1400 void, (void *tc), NULL) 1401 1402/* The following member value is a pointer to a function called 1403 by the insn scheduler. 1404 The first parameter is an instruction, the second parameter is the type 1405 of the requested speculation, and the third parameter is a pointer to the 1406 speculative pattern of the corresponding type (set if return value == 1). 1407 It should return 1408 -1, if there is no pattern, that will satisfy the requested speculation type, 1409 0, if current pattern satisfies the requested speculation type, 1410 1, if pattern of the instruction should be changed to the newly 1411 generated one. */ 1412DEFHOOK 1413(speculate_insn, 1414 "This hook is called by the insn scheduler when @var{insn} has only\n\ 1415speculative dependencies and therefore can be scheduled speculatively.\n\ 1416The hook is used to check if the pattern of @var{insn} has a speculative\n\ 1417version and, in case of successful check, to generate that speculative\n\ 1418pattern. The hook should return 1, if the instruction has a speculative form,\n\ 1419or @minus{}1, if it doesn't. @var{request} describes the type of requested\n\ 1420speculation. If the return value equals 1 then @var{new_pat} is assigned\n\ 1421the generated speculative pattern.", 1422 int, (rtx_insn *insn, unsigned int dep_status, rtx *new_pat), NULL) 1423 1424/* The following member value is a pointer to a function called 1425 by the insn scheduler. It should return true if the check instruction 1426 passed as the parameter needs a recovery block. */ 1427DEFHOOK 1428(needs_block_p, 1429 "This hook is called by the insn scheduler during generation of recovery code\n\ 1430for @var{insn}. It should return @code{true}, if the corresponding check\n\ 1431instruction should branch to recovery code, or @code{false} otherwise.", 1432 bool, (unsigned int dep_status), NULL) 1433 1434/* The following member value is a pointer to a function called 1435 by the insn scheduler. It should return a pattern for the check 1436 instruction. 1437 The first parameter is a speculative instruction, the second parameter 1438 is the label of the corresponding recovery block (or null, if it is a 1439 simple check). The third parameter is the kind of speculation that 1440 is being performed. */ 1441DEFHOOK 1442(gen_spec_check, 1443 "This hook is called by the insn scheduler to generate a pattern for recovery\n\ 1444check instruction. If @var{mutate_p} is zero, then @var{insn} is a\n\ 1445speculative instruction for which the check should be generated.\n\ 1446@var{label} is either a label of a basic block, where recovery code should\n\ 1447be emitted, or a null pointer, when requested check doesn't branch to\n\ 1448recovery code (a simple check). If @var{mutate_p} is nonzero, then\n\ 1449a pattern for a branchy check corresponding to a simple check denoted by\n\ 1450@var{insn} should be generated. In this case @var{label} can't be null.", 1451 rtx, (rtx_insn *insn, rtx_insn *label, unsigned int ds), NULL) 1452 1453/* The following member value is a pointer to a function that provides 1454 information about the speculation capabilities of the target. 1455 The parameter is a pointer to spec_info variable. */ 1456DEFHOOK 1457(set_sched_flags, 1458 "This hook is used by the insn scheduler to find out what features should be\n\ 1459enabled/used.\n\ 1460The structure *@var{spec_info} should be filled in by the target.\n\ 1461The structure describes speculation types that can be used in the scheduler.", 1462 void, (struct spec_info_def *spec_info), NULL) 1463 1464DEFHOOK_UNDOC 1465(get_insn_spec_ds, 1466 "Return speculation types of instruction @var{insn}.", 1467 unsigned int, (rtx_insn *insn), NULL) 1468 1469DEFHOOK_UNDOC 1470(get_insn_checked_ds, 1471 "Return speculation types that are checked for instruction @var{insn}", 1472 unsigned int, (rtx_insn *insn), NULL) 1473 1474DEFHOOK_UNDOC 1475(skip_rtx_p, 1476 "Return bool if rtx scanning should just skip current layer and\ 1477 advance to the inner rtxes.", 1478 bool, (const_rtx x), NULL) 1479 1480/* The following member value is a pointer to a function that provides 1481 information about the target resource-based lower bound which is 1482 used by the swing modulo scheduler. The parameter is a pointer 1483 to ddg variable. */ 1484DEFHOOK 1485(sms_res_mii, 1486 "This hook is called by the swing modulo scheduler to calculate a\n\ 1487resource-based lower bound which is based on the resources available in\n\ 1488the machine and the resources required by each instruction. The target\n\ 1489backend can use @var{g} to calculate such bound. A very simple lower\n\ 1490bound will be used in case this hook is not implemented: the total number\n\ 1491of instructions divided by the issue rate.", 1492 int, (struct ddg *g), NULL) 1493 1494/* The following member value is a function that initializes dispatch 1495 schedling and adds instructions to dispatch window according to its 1496 parameters. */ 1497DEFHOOK 1498(dispatch_do, 1499"This hook is called by Haifa Scheduler. It performs the operation specified\n\ 1500in its second parameter.", 1501void, (rtx_insn *insn, int x), 1502hook_void_rtx_insn_int) 1503 1504/* The following member value is a a function that returns true is 1505 dispatch schedling is supported in hardware and condition passed 1506 as the second parameter is true. */ 1507DEFHOOK 1508(dispatch, 1509"This hook is called by Haifa Scheduler. It returns true if dispatch scheduling\n\ 1510is supported in hardware and the condition specified in the parameter is true.", 1511bool, (rtx_insn *insn, int x), 1512hook_bool_rtx_insn_int_false) 1513 1514DEFHOOKPOD 1515(exposed_pipeline, 1516"True if the processor has an exposed pipeline, which means that not just\n\ 1517the order of instructions is important for correctness when scheduling, but\n\ 1518also the latencies of operations.", 1519bool, false) 1520 1521/* The following member value is a function that returns number 1522 of operations reassociator should try to put in parallel for 1523 statements of the given type. By default 1 is used. */ 1524DEFHOOK 1525(reassociation_width, 1526"This hook is called by tree reassociator to determine a level of\n\ 1527parallelism required in output calculations chain.", 1528int, (unsigned int opc, machine_mode mode), 1529hook_int_uint_mode_1) 1530 1531/* The following member value is a function that returns priority for 1532 fusion of each instruction via pointer parameters. */ 1533DEFHOOK 1534(fusion_priority, 1535"This hook is called by scheduling fusion pass. It calculates fusion\n\ 1536priorities for each instruction passed in by parameter. The priorities\n\ 1537are returned via pointer parameters.\n\ 1538\n\ 1539@var{insn} is the instruction whose priorities need to be calculated.\n\ 1540@var{max_pri} is the maximum priority can be returned in any cases.\n\ 1541@var{fusion_pri} is the pointer parameter through which @var{insn}'s\n\ 1542fusion priority should be calculated and returned.\n\ 1543@var{pri} is the pointer parameter through which @var{insn}'s priority\n\ 1544should be calculated and returned.\n\ 1545\n\ 1546Same @var{fusion_pri} should be returned for instructions which should\n\ 1547be scheduled together. Different @var{pri} should be returned for\n\ 1548instructions with same @var{fusion_pri}. @var{fusion_pri} is the major\n\ 1549sort key, @var{pri} is the minor sort key. All instructions will be\n\ 1550scheduled according to the two priorities. All priorities calculated\n\ 1551should be between 0 (exclusive) and @var{max_pri} (inclusive). To avoid\n\ 1552false dependencies, @var{fusion_pri} of instructions which need to be\n\ 1553scheduled together should be smaller than @var{fusion_pri} of irrelevant\n\ 1554instructions.\n\ 1555\n\ 1556Given below example:\n\ 1557\n\ 1558@smallexample\n\ 1559 ldr r10, [r1, 4]\n\ 1560 add r4, r4, r10\n\ 1561 ldr r15, [r2, 8]\n\ 1562 sub r5, r5, r15\n\ 1563 ldr r11, [r1, 0]\n\ 1564 add r4, r4, r11\n\ 1565 ldr r16, [r2, 12]\n\ 1566 sub r5, r5, r16\n\ 1567@end smallexample\n\ 1568\n\ 1569On targets like ARM/AArch64, the two pairs of consecutive loads should be\n\ 1570merged. Since peephole2 pass can't help in this case unless consecutive\n\ 1571loads are actually next to each other in instruction flow. That's where\n\ 1572this scheduling fusion pass works. This hook calculates priority for each\n\ 1573instruction based on its fustion type, like:\n\ 1574\n\ 1575@smallexample\n\ 1576 ldr r10, [r1, 4] ; fusion_pri=99, pri=96\n\ 1577 add r4, r4, r10 ; fusion_pri=100, pri=100\n\ 1578 ldr r15, [r2, 8] ; fusion_pri=98, pri=92\n\ 1579 sub r5, r5, r15 ; fusion_pri=100, pri=100\n\ 1580 ldr r11, [r1, 0] ; fusion_pri=99, pri=100\n\ 1581 add r4, r4, r11 ; fusion_pri=100, pri=100\n\ 1582 ldr r16, [r2, 12] ; fusion_pri=98, pri=88\n\ 1583 sub r5, r5, r16 ; fusion_pri=100, pri=100\n\ 1584@end smallexample\n\ 1585\n\ 1586Scheduling fusion pass then sorts all ready to issue instructions according\n\ 1587to the priorities. As a result, instructions of same fusion type will be\n\ 1588pushed together in instruction flow, like:\n\ 1589\n\ 1590@smallexample\n\ 1591 ldr r11, [r1, 0]\n\ 1592 ldr r10, [r1, 4]\n\ 1593 ldr r15, [r2, 8]\n\ 1594 ldr r16, [r2, 12]\n\ 1595 add r4, r4, r10\n\ 1596 sub r5, r5, r15\n\ 1597 add r4, r4, r11\n\ 1598 sub r5, r5, r16\n\ 1599@end smallexample\n\ 1600\n\ 1601Now peephole2 pass can simply merge the two pairs of loads.\n\ 1602\n\ 1603Since scheduling fusion pass relies on peephole2 to do real fusion\n\ 1604work, it is only enabled by default when peephole2 is in effect.\n\ 1605\n\ 1606This is firstly introduced on ARM/AArch64 targets, please refer to\n\ 1607the hook implementation for how different fusion types are supported.", 1608void, (rtx_insn *insn, int max_pri, int *fusion_pri, int *pri), NULL) 1609 1610HOOK_VECTOR_END (sched) 1611 1612/* Functions relating to OpenMP and Cilk Plus SIMD clones. */ 1613#undef HOOK_PREFIX 1614#define HOOK_PREFIX "TARGET_SIMD_CLONE_" 1615HOOK_VECTOR (TARGET_SIMD_CLONE, simd_clone) 1616 1617DEFHOOK 1618(compute_vecsize_and_simdlen, 1619"This hook should set @var{vecsize_mangle}, @var{vecsize_int}, @var{vecsize_float}\n\ 1620fields in @var{simd_clone} structure pointed by @var{clone_info} argument and also\n\ 1621@var{simdlen} field if it was previously 0.\n\ 1622The hook should return 0 if SIMD clones shouldn't be emitted,\n\ 1623or number of @var{vecsize_mangle} variants that should be emitted.", 1624int, (struct cgraph_node *, struct cgraph_simd_clone *, tree, int), NULL) 1625 1626DEFHOOK 1627(adjust, 1628"This hook should add implicit @code{attribute(target(\"...\"))} attribute\n\ 1629to SIMD clone @var{node} if needed.", 1630void, (struct cgraph_node *), NULL) 1631 1632DEFHOOK 1633(usable, 1634"This hook should return -1 if SIMD clone @var{node} shouldn't be used\n\ 1635in vectorized loops in current function, or non-negative number if it is\n\ 1636usable. In that case, the smaller the number is, the more desirable it is\n\ 1637to use it.", 1638int, (struct cgraph_node *), NULL) 1639 1640HOOK_VECTOR_END (simd_clone) 1641 1642/* Functions relating to openacc. */ 1643#undef HOOK_PREFIX 1644#define HOOK_PREFIX "TARGET_GOACC_" 1645HOOK_VECTOR (TARGET_GOACC, goacc) 1646 1647DEFHOOK 1648(validate_dims, 1649"This hook should check the launch dimensions provided for an OpenACC\n\ 1650compute region, or routine. Defaulted values are represented as -1\n\ 1651and non-constant values as 0. The @var{fn_level} is negative for the\n\ 1652function corresponding to the compute region. For a routine is is the\n\ 1653outermost level at which partitioned execution may be spawned. The hook\n\ 1654should verify non-default values. If DECL is NULL, global defaults\n\ 1655are being validated and unspecified defaults should be filled in.\n\ 1656Diagnostics should be issued as appropriate. Return\n\ 1657true, if changes have been made. You must override this hook to\n\ 1658provide dimensions larger than 1.", 1659bool, (tree decl, int *dims, int fn_level), 1660default_goacc_validate_dims) 1661 1662DEFHOOK 1663(dim_limit, 1664"This hook should return the maximum size of a particular dimension,\n\ 1665or zero if unbounded.", 1666int, (int axis), 1667default_goacc_dim_limit) 1668 1669DEFHOOK 1670(fork_join, 1671"This hook can be used to convert IFN_GOACC_FORK and IFN_GOACC_JOIN\n\ 1672function calls to target-specific gimple, or indicate whether they\n\ 1673should be retained. It is executed during the oacc_device_lower pass.\n\ 1674It should return true, if the call should be retained. It should\n\ 1675return false, if it is to be deleted (either because target-specific\n\ 1676gimple has been inserted before it, or there is no need for it).\n\ 1677The default hook returns false, if there are no RTL expanders for them.", 1678bool, (gcall *call, const int *dims, bool is_fork), 1679default_goacc_fork_join) 1680 1681DEFHOOK 1682(reduction, 1683"This hook is used by the oacc_transform pass to expand calls to the\n\ 1684@var{GOACC_REDUCTION} internal function, into a sequence of gimple\n\ 1685instructions. @var{call} is gimple statement containing the call to\n\ 1686the function. This hook removes statement @var{call} after the\n\ 1687expanded sequence has been inserted. This hook is also responsible\n\ 1688for allocating any storage for reductions when necessary.", 1689void, (gcall *call), 1690default_goacc_reduction) 1691 1692HOOK_VECTOR_END (goacc) 1693 1694/* Functions relating to vectorization. */ 1695#undef HOOK_PREFIX 1696#define HOOK_PREFIX "TARGET_VECTORIZE_" 1697HOOK_VECTOR (TARGET_VECTORIZE, vectorize) 1698 1699/* The following member value is a pointer to a function called 1700 by the vectorizer, and return the decl of the target builtin 1701 function. */ 1702DEFHOOK 1703(builtin_mask_for_load, 1704 "This hook should return the DECL of a function @var{f} that given an\n\ 1705address @var{addr} as an argument returns a mask @var{m} that can be\n\ 1706used to extract from two vectors the relevant data that resides in\n\ 1707@var{addr} in case @var{addr} is not properly aligned.\n\ 1708\n\ 1709The autovectorizer, when vectorizing a load operation from an address\n\ 1710@var{addr} that may be unaligned, will generate two vector loads from\n\ 1711the two aligned addresses around @var{addr}. It then generates a\n\ 1712@code{REALIGN_LOAD} operation to extract the relevant data from the\n\ 1713two loaded vectors. The first two arguments to @code{REALIGN_LOAD},\n\ 1714@var{v1} and @var{v2}, are the two vectors, each of size @var{VS}, and\n\ 1715the third argument, @var{OFF}, defines how the data will be extracted\n\ 1716from these two vectors: if @var{OFF} is 0, then the returned vector is\n\ 1717@var{v2}; otherwise, the returned vector is composed from the last\n\ 1718@var{VS}-@var{OFF} elements of @var{v1} concatenated to the first\n\ 1719@var{OFF} elements of @var{v2}.\n\ 1720\n\ 1721If this hook is defined, the autovectorizer will generate a call\n\ 1722to @var{f} (using the DECL tree that this hook returns) and will\n\ 1723use the return value of @var{f} as the argument @var{OFF} to\n\ 1724@code{REALIGN_LOAD}. Therefore, the mask @var{m} returned by @var{f}\n\ 1725should comply with the semantics expected by @code{REALIGN_LOAD}\n\ 1726described above.\n\ 1727If this hook is not defined, then @var{addr} will be used as\n\ 1728the argument @var{OFF} to @code{REALIGN_LOAD}, in which case the low\n\ 1729log2(@var{VS}) @minus{} 1 bits of @var{addr} will be considered.", 1730 tree, (void), NULL) 1731 1732/* Returns a built-in function that realizes the vectorized version of 1733 a target-independent function, or NULL_TREE if not available. */ 1734DEFHOOK 1735(builtin_vectorized_function, 1736 "This hook should return the decl of a function that implements the\n\ 1737vectorized variant of the function with the @code{combined_fn} code\n\ 1738@var{code} or @code{NULL_TREE} if such a function is not available.\n\ 1739The return type of the vectorized function shall be of vector type\n\ 1740@var{vec_type_out} and the argument types should be @var{vec_type_in}.", 1741 tree, (unsigned code, tree vec_type_out, tree vec_type_in), 1742 default_builtin_vectorized_function) 1743 1744/* Returns a built-in function that realizes the vectorized version of 1745 a target-specific function, or NULL_TREE if not available. */ 1746DEFHOOK 1747(builtin_md_vectorized_function, 1748 "This hook should return the decl of a function that implements the\n\ 1749vectorized variant of target built-in function @code{fndecl}. The\n\ 1750return type of the vectorized function shall be of vector type\n\ 1751@var{vec_type_out} and the argument types should be @var{vec_type_in}.", 1752 tree, (tree fndecl, tree vec_type_out, tree vec_type_in), 1753 default_builtin_md_vectorized_function) 1754 1755/* Returns a function declaration for a builtin that realizes the 1756 vector conversion, or NULL_TREE if not available. */ 1757DEFHOOK 1758(builtin_conversion, 1759 "This hook should return the DECL of a function that implements conversion of the\n\ 1760input vector of type @var{src_type} to type @var{dest_type}.\n\ 1761The value of @var{code} is one of the enumerators in @code{enum tree_code} and\n\ 1762specifies how the conversion is to be applied\n\ 1763(truncation, rounding, etc.).\n\ 1764\n\ 1765If this hook is defined, the autovectorizer will use the\n\ 1766@code{TARGET_VECTORIZE_BUILTIN_CONVERSION} target hook when vectorizing\n\ 1767conversion. Otherwise, it will return @code{NULL_TREE}.", 1768 tree, (unsigned code, tree dest_type, tree src_type), 1769 default_builtin_vectorized_conversion) 1770 1771/* Cost of different vector/scalar statements in vectorization cost 1772 model. In case of misaligned vector loads and stores the cost depends 1773 on the data type and misalignment value. */ 1774DEFHOOK 1775(builtin_vectorization_cost, 1776 "Returns cost of different scalar or vector statements for vectorization cost model.\n\ 1777For vector memory operations the cost may depend on type (@var{vectype}) and\n\ 1778misalignment value (@var{misalign}).", 1779 int, (enum vect_cost_for_stmt type_of_cost, tree vectype, int misalign), 1780 default_builtin_vectorization_cost) 1781 1782/* Return true if vector alignment is reachable (by peeling N 1783 iterations) for the given scalar type. */ 1784DEFHOOK 1785(vector_alignment_reachable, 1786 "Return true if vector alignment is reachable (by peeling N iterations) for the given scalar type @var{type}. @var{is_packed} is false if the scalar access using @var{type} is known to be naturally aligned.", 1787 bool, (const_tree type, bool is_packed), 1788 default_builtin_vector_alignment_reachable) 1789 1790/* Return true if a vector created for vec_perm_const is valid. 1791 A NULL indicates that all constants are valid permutations. */ 1792DEFHOOK 1793(vec_perm_const_ok, 1794 "Return true if a vector created for @code{vec_perm_const} is valid.", 1795 bool, (machine_mode, const unsigned char *sel), 1796 NULL) 1797 1798/* Return true if the target supports misaligned store/load of a 1799 specific factor denoted in the third parameter. The last parameter 1800 is true if the access is defined in a packed struct. */ 1801DEFHOOK 1802(support_vector_misalignment, 1803 "This hook should return true if the target supports misaligned vector\n\ 1804store/load of a specific factor denoted in the @var{misalignment}\n\ 1805parameter. The vector store/load should be of machine mode @var{mode} and\n\ 1806the elements in the vectors should be of type @var{type}. @var{is_packed}\n\ 1807parameter is true if the memory access is defined in a packed struct.", 1808 bool, 1809 (machine_mode mode, const_tree type, int misalignment, bool is_packed), 1810 default_builtin_support_vector_misalignment) 1811 1812/* Returns the preferred mode for SIMD operations for the specified 1813 scalar mode. */ 1814DEFHOOK 1815(preferred_simd_mode, 1816 "This hook should return the preferred mode for vectorizing scalar\n\ 1817mode @var{mode}. The default is\n\ 1818equal to @code{word_mode}, because the vectorizer can do some\n\ 1819transformations even in absence of specialized @acronym{SIMD} hardware.", 1820 machine_mode, 1821 (machine_mode mode), 1822 default_preferred_simd_mode) 1823 1824/* Returns a mask of vector sizes to iterate over when auto-vectorizing 1825 after processing the preferred one derived from preferred_simd_mode. */ 1826DEFHOOK 1827(autovectorize_vector_sizes, 1828 "This hook should return a mask of sizes that should be iterated over\n\ 1829after trying to autovectorize using the vector size derived from the\n\ 1830mode returned by @code{TARGET_VECTORIZE_PREFERRED_SIMD_MODE}.\n\ 1831The default is zero which means to not iterate over other vector sizes.", 1832 unsigned int, 1833 (void), 1834 default_autovectorize_vector_sizes) 1835 1836/* Function to get a target mode for a vector mask. */ 1837DEFHOOK 1838(get_mask_mode, 1839 "This hook returns mode to be used for a mask to be used for a vector\n\ 1840of specified @var{length} with @var{nunits} elements. By default an integer\n\ 1841vector mode of a proper size is returned.", 1842 machine_mode, 1843 (unsigned nunits, unsigned length), 1844 default_get_mask_mode) 1845 1846/* Target builtin that implements vector gather operation. */ 1847DEFHOOK 1848(builtin_gather, 1849 "Target builtin that implements vector gather operation. @var{mem_vectype}\n\ 1850is the vector type of the load and @var{index_type} is scalar type of\n\ 1851the index, scaled by @var{scale}.\n\ 1852The default is @code{NULL_TREE} which means to not vectorize gather\n\ 1853loads.", 1854 tree, 1855 (const_tree mem_vectype, const_tree index_type, int scale), 1856 NULL) 1857 1858/* Target builtin that implements vector scatter operation. */ 1859DEFHOOK 1860(builtin_scatter, 1861"Target builtin that implements vector scatter operation. @var{vectype}\n\ 1862is the vector type of the store and @var{index_type} is scalar type of\n\ 1863the index, scaled by @var{scale}.\n\ 1864The default is @code{NULL_TREE} which means to not vectorize scatter\n\ 1865stores.", 1866 tree, 1867 (const_tree vectype, const_tree index_type, int scale), 1868 NULL) 1869 1870/* Target function to initialize the cost model for a loop or block. */ 1871DEFHOOK 1872(init_cost, 1873 "This hook should initialize target-specific data structures in preparation " 1874 "for modeling the costs of vectorizing a loop or basic block. The default " 1875 "allocates three unsigned integers for accumulating costs for the prologue, " 1876 "body, and epilogue of the loop or basic block. If @var{loop_info} is " 1877 "non-NULL, it identifies the loop being vectorized; otherwise a single block " 1878 "is being vectorized.", 1879 void *, 1880 (struct loop *loop_info), 1881 default_init_cost) 1882 1883/* Target function to record N statements of the given kind using the 1884 given vector type within the cost model data for the current loop or 1885 block. */ 1886DEFHOOK 1887(add_stmt_cost, 1888 "This hook should update the target-specific @var{data} in response to " 1889 "adding @var{count} copies of the given @var{kind} of statement to a " 1890 "loop or basic block. The default adds the builtin vectorizer cost for " 1891 "the copies of the statement to the accumulator specified by @var{where}, " 1892 "(the prologue, body, or epilogue) and returns the amount added. The " 1893 "return value should be viewed as a tentative cost that may later be " 1894 "revised.", 1895 unsigned, 1896 (void *data, int count, enum vect_cost_for_stmt kind, 1897 struct _stmt_vec_info *stmt_info, int misalign, 1898 enum vect_cost_model_location where), 1899 default_add_stmt_cost) 1900 1901/* Target function to calculate the total cost of the current vectorized 1902 loop or block. */ 1903DEFHOOK 1904(finish_cost, 1905 "This hook should complete calculations of the cost of vectorizing a loop " 1906 "or basic block based on @var{data}, and return the prologue, body, and " 1907 "epilogue costs as unsigned integers. The default returns the value of " 1908 "the three accumulators.", 1909 void, 1910 (void *data, unsigned *prologue_cost, unsigned *body_cost, 1911 unsigned *epilogue_cost), 1912 default_finish_cost) 1913 1914/* Function to delete target-specific cost modeling data. */ 1915DEFHOOK 1916(destroy_cost_data, 1917 "This hook should release @var{data} and any related data structures " 1918 "allocated by TARGET_VECTORIZE_INIT_COST. The default releases the " 1919 "accumulator.", 1920 void, 1921 (void *data), 1922 default_destroy_cost_data) 1923 1924HOOK_VECTOR_END (vectorize) 1925 1926#undef HOOK_PREFIX 1927#define HOOK_PREFIX "TARGET_" 1928 1929DEFHOOK 1930(record_offload_symbol, 1931 "Used when offloaded functions are seen in the compilation unit and no named\n\ 1932sections are available. It is called once for each symbol that must be\n\ 1933recorded in the offload function and variable table.", 1934 void, (tree), 1935 hook_void_tree) 1936 1937DEFHOOKPOD 1938(absolute_biggest_alignment, 1939 "If defined, this target hook specifies the absolute biggest alignment\n\ 1940that a type or variable can have on this machine, otherwise,\n\ 1941@code{BIGGEST_ALIGNMENT} is used.", 1942 HOST_WIDE_INT, BIGGEST_ALIGNMENT) 1943 1944/* Allow target specific overriding of option settings after options have 1945 been changed by an attribute or pragma or when it is reset at the 1946 end of the code affected by an attribute or pragma. */ 1947DEFHOOK 1948(override_options_after_change, 1949 "This target function is similar to the hook @code{TARGET_OPTION_OVERRIDE}\n\ 1950but is called when the optimize level is changed via an attribute or\n\ 1951pragma or when it is reset at the end of the code affected by the\n\ 1952attribute or pragma. It is not called at the beginning of compilation\n\ 1953when @code{TARGET_OPTION_OVERRIDE} is called so if you want to perform these\n\ 1954actions then, you should have @code{TARGET_OPTION_OVERRIDE} call\n\ 1955@code{TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE}.", 1956 void, (void), 1957 hook_void_void) 1958 1959DEFHOOK 1960(offload_options, 1961 "Used when writing out the list of options into an LTO file. It should\n\ 1962translate any relevant target-specific options (such as the ABI in use)\n\ 1963into one of the @option{-foffload} options that exist as a common interface\n\ 1964to express such options. It should return a string containing these options,\n\ 1965separated by spaces, which the caller will free.\n", 1966char *, (void), hook_charptr_void_null) 1967 1968DEFHOOK_UNDOC 1969(eh_return_filter_mode, 1970 "Return machine mode for filter value.", 1971 machine_mode, (void), 1972 default_eh_return_filter_mode) 1973 1974/* Return machine mode for libgcc expanded cmp instructions. */ 1975DEFHOOK 1976(libgcc_cmp_return_mode, 1977 "This target hook should return the mode to be used for the return value\n\ 1978of compare instructions expanded to libgcc calls. If not defined\n\ 1979@code{word_mode} is returned which is the right choice for a majority of\n\ 1980targets.", 1981 machine_mode, (void), 1982 default_libgcc_cmp_return_mode) 1983 1984/* Return machine mode for libgcc expanded shift instructions. */ 1985DEFHOOK 1986(libgcc_shift_count_mode, 1987 "This target hook should return the mode to be used for the shift count operand\n\ 1988of shift instructions expanded to libgcc calls. If not defined\n\ 1989@code{word_mode} is returned which is the right choice for a majority of\n\ 1990targets.", 1991 machine_mode, (void), 1992 default_libgcc_shift_count_mode) 1993 1994/* Return machine mode to be used for _Unwind_Word type. */ 1995DEFHOOK 1996(unwind_word_mode, 1997 "Return machine mode to be used for @code{_Unwind_Word} type.\n\ 1998The default is to use @code{word_mode}.", 1999 machine_mode, (void), 2000 default_unwind_word_mode) 2001 2002/* Given two decls, merge their attributes and return the result. */ 2003DEFHOOK 2004(merge_decl_attributes, 2005 "Define this target hook if the merging of decl attributes needs special\n\ 2006handling. If defined, the result is a list of the combined\n\ 2007@code{DECL_ATTRIBUTES} of @var{olddecl} and @var{newdecl}.\n\ 2008@var{newdecl} is a duplicate declaration of @var{olddecl}. Examples of\n\ 2009when this is needed are when one attribute overrides another, or when an\n\ 2010attribute is nullified by a subsequent definition. This function may\n\ 2011call @code{merge_attributes} to handle machine-independent merging.\n\ 2012\n\ 2013@findex TARGET_DLLIMPORT_DECL_ATTRIBUTES\n\ 2014If the only target-specific handling you require is @samp{dllimport}\n\ 2015for Microsoft Windows targets, you should define the macro\n\ 2016@code{TARGET_DLLIMPORT_DECL_ATTRIBUTES} to @code{1}. The compiler\n\ 2017will then define a function called\n\ 2018@code{merge_dllimport_decl_attributes} which can then be defined as\n\ 2019the expansion of @code{TARGET_MERGE_DECL_ATTRIBUTES}. You can also\n\ 2020add @code{handle_dll_attribute} in the attribute table for your port\n\ 2021to perform initial processing of the @samp{dllimport} and\n\ 2022@samp{dllexport} attributes. This is done in @file{i386/cygwin.h} and\n\ 2023@file{i386/i386.c}, for example.", 2024 tree, (tree olddecl, tree newdecl), 2025 merge_decl_attributes) 2026 2027/* Given two types, merge their attributes and return the result. */ 2028DEFHOOK 2029(merge_type_attributes, 2030 "Define this target hook if the merging of type attributes needs special\n\ 2031handling. If defined, the result is a list of the combined\n\ 2032@code{TYPE_ATTRIBUTES} of @var{type1} and @var{type2}. It is assumed\n\ 2033that @code{comptypes} has already been called and returned 1. This\n\ 2034function may call @code{merge_attributes} to handle machine-independent\n\ 2035merging.", 2036 tree, (tree type1, tree type2), 2037 merge_type_attributes) 2038 2039/* Table of machine attributes and functions to handle them. 2040 Ignored if NULL. */ 2041DEFHOOKPOD 2042(attribute_table, 2043 "If defined, this target hook points to an array of @samp{struct\n\ 2044attribute_spec} (defined in @file{tree-core.h}) specifying the machine\n\ 2045specific attributes for this target and some of the restrictions on the\n\ 2046entities to which these attributes are applied and the arguments they\n\ 2047take.", 2048 const struct attribute_spec *, NULL) 2049 2050/* Return true iff attribute NAME expects a plain identifier as its first 2051 argument. */ 2052DEFHOOK 2053(attribute_takes_identifier_p, 2054 "If defined, this target hook is a function which returns true if the\n\ 2055machine-specific attribute named @var{name} expects an identifier\n\ 2056given as its first argument to be passed on as a plain identifier, not\n\ 2057subjected to name lookup. If this is not defined, the default is\n\ 2058false for all machine-specific attributes.", 2059 bool, (const_tree name), 2060 hook_bool_const_tree_false) 2061 2062/* Return zero if the attributes on TYPE1 and TYPE2 are incompatible, 2063 one if they are compatible and two if they are nearly compatible 2064 (which causes a warning to be generated). */ 2065DEFHOOK 2066(comp_type_attributes, 2067 "If defined, this target hook is a function which returns zero if the attributes on\n\ 2068@var{type1} and @var{type2} are incompatible, one if they are compatible,\n\ 2069and two if they are nearly compatible (which causes a warning to be\n\ 2070generated). If this is not defined, machine-specific attributes are\n\ 2071supposed always to be compatible.", 2072 int, (const_tree type1, const_tree type2), 2073 hook_int_const_tree_const_tree_1) 2074 2075/* Assign default attributes to the newly defined TYPE. */ 2076DEFHOOK 2077(set_default_type_attributes, 2078 "If defined, this target hook is a function which assigns default attributes to\n\ 2079the newly defined @var{type}.", 2080 void, (tree type), 2081 hook_void_tree) 2082 2083/* Insert attributes on the newly created DECL. */ 2084DEFHOOK 2085(insert_attributes, 2086 "Define this target hook if you want to be able to add attributes to a decl\n\ 2087when it is being created. This is normally useful for back ends which\n\ 2088wish to implement a pragma by using the attributes which correspond to\n\ 2089the pragma's effect. The @var{node} argument is the decl which is being\n\ 2090created. The @var{attr_ptr} argument is a pointer to the attribute list\n\ 2091for this decl. The list itself should not be modified, since it may be\n\ 2092shared with other decls, but attributes may be chained on the head of\n\ 2093the list and @code{*@var{attr_ptr}} modified to point to the new\n\ 2094attributes, or a copy of the list may be made if further changes are\n\ 2095needed.", 2096 void, (tree node, tree *attr_ptr), 2097 hook_void_tree_treeptr) 2098 2099/* Return true if FNDECL (which has at least one machine attribute) 2100 can be inlined despite its machine attributes, false otherwise. */ 2101DEFHOOK 2102(function_attribute_inlinable_p, 2103 "@cindex inlining\n\ 2104This target hook returns @code{true} if it is OK to inline @var{fndecl}\n\ 2105into the current function, despite its having target-specific\n\ 2106attributes, @code{false} otherwise. By default, if a function has a\n\ 2107target specific attribute attached to it, it will not be inlined.", 2108 bool, (const_tree fndecl), 2109 hook_bool_const_tree_false) 2110 2111/* Return true if bitfields in RECORD_TYPE should follow the 2112 Microsoft Visual C++ bitfield layout rules. */ 2113DEFHOOK 2114(ms_bitfield_layout_p, 2115 "This target hook returns @code{true} if bit-fields in the given\n\ 2116@var{record_type} are to be laid out following the rules of Microsoft\n\ 2117Visual C/C++, namely: (i) a bit-field won't share the same storage\n\ 2118unit with the previous bit-field if their underlying types have\n\ 2119different sizes, and the bit-field will be aligned to the highest\n\ 2120alignment of the underlying types of itself and of the previous\n\ 2121bit-field; (ii) a zero-sized bit-field will affect the alignment of\n\ 2122the whole enclosing structure, even if it is unnamed; except that\n\ 2123(iii) a zero-sized bit-field will be disregarded unless it follows\n\ 2124another bit-field of nonzero size. If this hook returns @code{true},\n\ 2125other macros that control bit-field layout are ignored.\n\ 2126\n\ 2127When a bit-field is inserted into a packed record, the whole size\n\ 2128of the underlying type is used by one or more same-size adjacent\n\ 2129bit-fields (that is, if its long:3, 32 bits is used in the record,\n\ 2130and any additional adjacent long bit-fields are packed into the same\n\ 2131chunk of 32 bits. However, if the size changes, a new field of that\n\ 2132size is allocated). In an unpacked record, this is the same as using\n\ 2133alignment, but not equivalent when packing.\n\ 2134\n\ 2135If both MS bit-fields and @samp{__attribute__((packed))} are used,\n\ 2136the latter will take precedence. If @samp{__attribute__((packed))} is\n\ 2137used on a single field when MS bit-fields are in use, it will take\n\ 2138precedence for that field, but the alignment of the rest of the structure\n\ 2139may affect its placement.", 2140 bool, (const_tree record_type), 2141 hook_bool_const_tree_false) 2142 2143/* For now this is only an interface to WORDS_BIG_ENDIAN for 2144 target-independent code like the front ends, need performance testing 2145 before switching completely to the target hook. */ 2146DEFHOOK_UNDOC 2147(words_big_endian, 2148 "", 2149 bool, (void), 2150 targhook_words_big_endian) 2151 2152/* Likewise for FLOAT_WORDS_BIG_ENDIAN. */ 2153DEFHOOK_UNDOC 2154(float_words_big_endian, 2155 "", 2156 bool, (void), 2157 targhook_float_words_big_endian) 2158 2159DEFHOOK 2160(float_exceptions_rounding_supported_p, 2161 "Returns true if the target supports IEEE 754 floating-point exceptions\ 2162 and rounding modes, false otherwise. This is intended to relate to the\ 2163 @code{float} and @code{double} types, but not necessarily @code{long double}.\ 2164 By default, returns true if the @code{adddf3} instruction pattern is\ 2165 available and false otherwise, on the assumption that hardware floating\ 2166 point supports exceptions and rounding modes but software floating point\ 2167 does not.", 2168 bool, (void), 2169 default_float_exceptions_rounding_supported_p) 2170 2171/* True if the target supports decimal floating point. */ 2172DEFHOOK 2173(decimal_float_supported_p, 2174 "Returns true if the target supports decimal floating point.", 2175 bool, (void), 2176 default_decimal_float_supported_p) 2177 2178/* True if the target supports fixed-point. */ 2179DEFHOOK 2180(fixed_point_supported_p, 2181 "Returns true if the target supports fixed-point arithmetic.", 2182 bool, (void), 2183 default_fixed_point_supported_p) 2184 2185/* Return true if anonymous bitfields affect structure alignment. */ 2186DEFHOOK 2187(align_anon_bitfield, 2188 "When @code{PCC_BITFIELD_TYPE_MATTERS} is true this hook will determine\n\ 2189whether unnamed bitfields affect the alignment of the containing\n\ 2190structure. The hook should return true if the structure should inherit\n\ 2191the alignment requirements of an unnamed bitfield's type.", 2192 bool, (void), 2193 hook_bool_void_false) 2194 2195/* Return true if volatile bitfields should use the narrowest type possible. 2196 Return false if they should use the container type. */ 2197DEFHOOK 2198(narrow_volatile_bitfield, 2199 "This target hook should return @code{true} if accesses to volatile bitfields\n\ 2200should use the narrowest mode possible. It should return @code{false} if\n\ 2201these accesses should use the bitfield container type.\n\ 2202\n\ 2203The default is @code{false}.", 2204 bool, (void), 2205 hook_bool_void_false) 2206 2207/* Set up target-specific built-in functions. */ 2208DEFHOOK 2209(init_builtins, 2210 "Define this hook if you have any machine-specific built-in functions\n\ 2211that need to be defined. It should be a function that performs the\n\ 2212necessary setup.\n\ 2213\n\ 2214Machine specific built-in functions can be useful to expand special machine\n\ 2215instructions that would otherwise not normally be generated because\n\ 2216they have no equivalent in the source language (for example, SIMD vector\n\ 2217instructions or prefetch instructions).\n\ 2218\n\ 2219To create a built-in function, call the function\n\ 2220@code{lang_hooks.builtin_function}\n\ 2221which is defined by the language front end. You can use any type nodes set\n\ 2222up by @code{build_common_tree_nodes};\n\ 2223only language front ends that use those two functions will call\n\ 2224@samp{TARGET_INIT_BUILTINS}.", 2225 void, (void), 2226 hook_void_void) 2227 2228/* Initialize (if INITIALIZE_P is true) and return the target-specific 2229 built-in function decl for CODE. 2230 Return NULL if that is not possible. Return error_mark_node if CODE 2231 is outside of the range of valid target builtin function codes. */ 2232DEFHOOK 2233(builtin_decl, 2234 "Define this hook if you have any machine-specific built-in functions\n\ 2235that need to be defined. It should be a function that returns the\n\ 2236builtin function declaration for the builtin function code @var{code}.\n\ 2237If there is no such builtin and it cannot be initialized at this time\n\ 2238if @var{initialize_p} is true the function should return @code{NULL_TREE}.\n\ 2239If @var{code} is out of range the function should return\n\ 2240@code{error_mark_node}.", 2241 tree, (unsigned code, bool initialize_p), NULL) 2242 2243/* Expand a target-specific builtin. */ 2244DEFHOOK 2245(expand_builtin, 2246 "\n\ 2247Expand a call to a machine specific built-in function that was set up by\n\ 2248@samp{TARGET_INIT_BUILTINS}. @var{exp} is the expression for the\n\ 2249function call; the result should go to @var{target} if that is\n\ 2250convenient, and have mode @var{mode} if that is convenient.\n\ 2251@var{subtarget} may be used as the target for computing one of\n\ 2252@var{exp}'s operands. @var{ignore} is nonzero if the value is to be\n\ 2253ignored. This function should return the result of the call to the\n\ 2254built-in function.", 2255 rtx, 2256 (tree exp, rtx target, rtx subtarget, machine_mode mode, int ignore), 2257 default_expand_builtin) 2258 2259DEFHOOK 2260(builtin_chkp_function, 2261 "This hook allows target to redefine built-in functions used by\n\ 2262Pointer Bounds Checker for code instrumentation. Hook should return\n\ 2263fndecl of function implementing generic builtin whose code is\n\ 2264passed in @var{fcode}. Currently following built-in functions are\n\ 2265obtained using this hook:\n\ 2266@deftypefn {Built-in Function} __bounds_type __chkp_bndmk (const void *@var{lb}, size_t @var{size})\n\ 2267Function code - BUILT_IN_CHKP_BNDMK. This built-in function is used\n\ 2268by Pointer Bounds Checker to create bound values. @var{lb} holds low\n\ 2269bound of the resulting bounds. @var{size} holds size of created bounds.\n\ 2270@end deftypefn\n\ 2271\n\ 2272@deftypefn {Built-in Function} void __chkp_bndstx (const void *@var{ptr}, __bounds_type @var{b}, const void **@var{loc})\n\ 2273Function code - @code{BUILT_IN_CHKP_BNDSTX}. This built-in function is used\n\ 2274by Pointer Bounds Checker to store bounds @var{b} for pointer @var{ptr}\n\ 2275when @var{ptr} is stored by address @var{loc}.\n\ 2276@end deftypefn\n\ 2277\n\ 2278@deftypefn {Built-in Function} __bounds_type __chkp_bndldx (const void **@var{loc}, const void *@var{ptr})\n\ 2279Function code - @code{BUILT_IN_CHKP_BNDLDX}. This built-in function is used\n\ 2280by Pointer Bounds Checker to get bounds of pointer @var{ptr} loaded by\n\ 2281address @var{loc}.\n\ 2282@end deftypefn\n\ 2283\n\ 2284@deftypefn {Built-in Function} void __chkp_bndcl (const void *@var{ptr}, __bounds_type @var{b})\n\ 2285Function code - @code{BUILT_IN_CHKP_BNDCL}. This built-in function is used\n\ 2286by Pointer Bounds Checker to perform check for pointer @var{ptr} against\n\ 2287lower bound of bounds @var{b}.\n\ 2288@end deftypefn\n\ 2289\n\ 2290@deftypefn {Built-in Function} void __chkp_bndcu (const void *@var{ptr}, __bounds_type @var{b})\n\ 2291Function code - @code{BUILT_IN_CHKP_BNDCU}. This built-in function is used\n\ 2292by Pointer Bounds Checker to perform check for pointer @var{ptr} against\n\ 2293upper bound of bounds @var{b}.\n\ 2294@end deftypefn\n\ 2295\n\ 2296@deftypefn {Built-in Function} __bounds_type __chkp_bndret (void *@var{ptr})\n\ 2297Function code - @code{BUILT_IN_CHKP_BNDRET}. This built-in function is used\n\ 2298by Pointer Bounds Checker to obtain bounds returned by a call statement.\n\ 2299@var{ptr} passed to built-in is @code{SSA_NAME} returned by the call.\n\ 2300@end deftypefn\n\ 2301\n\ 2302@deftypefn {Built-in Function} __bounds_type __chkp_intersect (__bounds_type @var{b1}, __bounds_type @var{b2})\n\ 2303Function code - @code{BUILT_IN_CHKP_INTERSECT}. This built-in function\n\ 2304returns intersection of bounds @var{b1} and @var{b2}.\n\ 2305@end deftypefn\n\ 2306\n\ 2307@deftypefn {Built-in Function} __bounds_type __chkp_narrow (const void *@var{ptr}, __bounds_type @var{b}, size_t @var{s})\n\ 2308Function code - @code{BUILT_IN_CHKP_NARROW}. This built-in function\n\ 2309returns intersection of bounds @var{b} and\n\ 2310[@var{ptr}, @var{ptr} + @var{s} - @code{1}].\n\ 2311@end deftypefn\n\ 2312\n\ 2313@deftypefn {Built-in Function} size_t __chkp_sizeof (const void *@var{ptr})\n\ 2314Function code - @code{BUILT_IN_CHKP_SIZEOF}. This built-in function\n\ 2315returns size of object referenced by @var{ptr}. @var{ptr} is always\n\ 2316@code{ADDR_EXPR} of @code{VAR_DECL}. This built-in is used by\n\ 2317Pointer Bounds Checker when bounds of object cannot be computed statically\n\ 2318(e.g. object has incomplete type).\n\ 2319@end deftypefn\n\ 2320\n\ 2321@deftypefn {Built-in Function} const void *__chkp_extract_lower (__bounds_type @var{b})\n\ 2322Function code - @code{BUILT_IN_CHKP_EXTRACT_LOWER}. This built-in function\n\ 2323returns lower bound of bounds @var{b}.\n\ 2324@end deftypefn\n\ 2325\n\ 2326@deftypefn {Built-in Function} const void *__chkp_extract_upper (__bounds_type @var{b})\n\ 2327Function code - @code{BUILT_IN_CHKP_EXTRACT_UPPER}. This built-in function\n\ 2328returns upper bound of bounds @var{b}.\n\ 2329@end deftypefn", 2330 tree, (unsigned fcode), 2331 default_builtin_chkp_function) 2332 2333DEFHOOK 2334(chkp_bound_type, 2335 "Return type to be used for bounds", 2336 tree, (void), 2337 default_chkp_bound_type) 2338 2339DEFHOOK 2340(chkp_bound_mode, 2341 "Return mode to be used for bounds.", 2342 enum machine_mode, (void), 2343 default_chkp_bound_mode) 2344 2345DEFHOOK 2346(chkp_make_bounds_constant, 2347 "Return constant used to statically initialize constant bounds\n\ 2348with specified lower bound @var{lb} and upper bounds @var{ub}.", 2349 tree, (HOST_WIDE_INT lb, HOST_WIDE_INT ub), 2350 default_chkp_make_bounds_constant) 2351 2352DEFHOOK 2353(chkp_initialize_bounds, 2354 "Generate a list of statements @var{stmts} to initialize pointer\n\ 2355bounds variable @var{var} with bounds @var{lb} and @var{ub}. Return\n\ 2356the number of generated statements.", 2357 int, (tree var, tree lb, tree ub, tree *stmts), 2358 default_chkp_initialize_bounds) 2359 2360/* Select a replacement for a target-specific builtin. This is done 2361 *before* regular type checking, and so allows the target to 2362 implement a crude form of function overloading. The result is a 2363 complete expression that implements the operation. PARAMS really 2364 has type VEC(tree,gc)*, but we don't want to include tree.h here. */ 2365DEFHOOK 2366(resolve_overloaded_builtin, 2367 "Select a replacement for a machine specific built-in function that\n\ 2368was set up by @samp{TARGET_INIT_BUILTINS}. This is done\n\ 2369@emph{before} regular type checking, and so allows the target to\n\ 2370implement a crude form of function overloading. @var{fndecl} is the\n\ 2371declaration of the built-in function. @var{arglist} is the list of\n\ 2372arguments passed to the built-in function. The result is a\n\ 2373complete expression that implements the operation, usually\n\ 2374another @code{CALL_EXPR}.\n\ 2375@var{arglist} really has type @samp{VEC(tree,gc)*}", 2376 tree, (unsigned int /*location_t*/ loc, tree fndecl, void *arglist), NULL) 2377 2378/* Fold a target-specific builtin to a tree valid for both GIMPLE 2379 and GENERIC. */ 2380DEFHOOK 2381(fold_builtin, 2382 "Fold a call to a machine specific built-in function that was set up by\n\ 2383@samp{TARGET_INIT_BUILTINS}. @var{fndecl} is the declaration of the\n\ 2384built-in function. @var{n_args} is the number of arguments passed to\n\ 2385the function; the arguments themselves are pointed to by @var{argp}.\n\ 2386The result is another tree, valid for both GIMPLE and GENERIC,\n\ 2387containing a simplified expression for the call's result. If\n\ 2388@var{ignore} is true the value will be ignored.", 2389 tree, (tree fndecl, int n_args, tree *argp, bool ignore), 2390 hook_tree_tree_int_treep_bool_null) 2391 2392/* Fold a target-specific builtin to a valid GIMPLE tree. */ 2393DEFHOOK 2394(gimple_fold_builtin, 2395 "Fold a call to a machine specific built-in function that was set up\n\ 2396by @samp{TARGET_INIT_BUILTINS}. @var{gsi} points to the gimple\n\ 2397statement holding the function call. Returns true if any change\n\ 2398was made to the GIMPLE stream.", 2399 bool, (gimple_stmt_iterator *gsi), 2400 hook_bool_gsiptr_false) 2401 2402/* Target hook is used to compare the target attributes in two functions to 2403 determine which function's features get higher priority. This is used 2404 during function multi-versioning to figure out the order in which two 2405 versions must be dispatched. A function version with a higher priority 2406 is checked for dispatching earlier. DECL1 and DECL2 are 2407 the two function decls that will be compared. It returns positive value 2408 if DECL1 is higher priority, negative value if DECL2 is higher priority 2409 and 0 if they are the same. */ 2410DEFHOOK 2411(compare_version_priority, 2412 "This hook is used to compare the target attributes in two functions to\n\ 2413determine which function's features get higher priority. This is used\n\ 2414during function multi-versioning to figure out the order in which two\n\ 2415versions must be dispatched. A function version with a higher priority\n\ 2416is checked for dispatching earlier. @var{decl1} and @var{decl2} are\n\ 2417 the two function decls that will be compared.", 2418 int, (tree decl1, tree decl2), NULL) 2419 2420/* Target hook is used to generate the dispatcher logic to invoke the right 2421 function version at run-time for a given set of function versions. 2422 ARG points to the callgraph node of the dispatcher function whose body 2423 must be generated. */ 2424DEFHOOK 2425(generate_version_dispatcher_body, 2426 "This hook is used to generate the dispatcher logic to invoke the right\n\ 2427function version at run-time for a given set of function versions.\n\ 2428@var{arg} points to the callgraph node of the dispatcher function whose\n\ 2429body must be generated.", 2430 tree, (void *arg), NULL) 2431 2432/* Target hook is used to get the dispatcher function for a set of function 2433 versions. The dispatcher function is called to invoke the right function 2434 version at run-time. DECL is one version from a set of semantically 2435 identical versions. */ 2436DEFHOOK 2437(get_function_versions_dispatcher, 2438 "This hook is used to get the dispatcher function for a set of function\n\ 2439versions. The dispatcher function is called to invoke the right function\n\ 2440version at run-time. @var{decl} is one version from a set of semantically\n\ 2441identical versions.", 2442 tree, (void *decl), NULL) 2443 2444/* Returns a code for a target-specific builtin that implements 2445 reciprocal of a target-specific function, or NULL_TREE if not available. */ 2446DEFHOOK 2447(builtin_reciprocal, 2448 "This hook should return the DECL of a function that implements the\n\ 2449reciprocal of the machine-specific builtin function @var{fndecl}, or\n\ 2450@code{NULL_TREE} if such a function is not available.", 2451 tree, (tree fndecl), 2452 default_builtin_reciprocal) 2453 2454/* For a vendor-specific TYPE, return a pointer to a statically-allocated 2455 string containing the C++ mangling for TYPE. In all other cases, return 2456 NULL. */ 2457DEFHOOK 2458(mangle_type, 2459 "If your target defines any fundamental types, or any types your target\n\ 2460uses should be mangled differently from the default, define this hook\n\ 2461to return the appropriate encoding for these types as part of a C++\n\ 2462mangled name. The @var{type} argument is the tree structure representing\n\ 2463the type to be mangled. The hook may be applied to trees which are\n\ 2464not target-specific fundamental types; it should return @code{NULL}\n\ 2465for all such types, as well as arguments it does not recognize. If the\n\ 2466return value is not @code{NULL}, it must point to a statically-allocated\n\ 2467string constant.\n\ 2468\n\ 2469Target-specific fundamental types might be new fundamental types or\n\ 2470qualified versions of ordinary fundamental types. Encode new\n\ 2471fundamental types as @samp{@w{u @var{n} @var{name}}}, where @var{name}\n\ 2472is the name used for the type in source code, and @var{n} is the\n\ 2473length of @var{name} in decimal. Encode qualified versions of\n\ 2474ordinary types as @samp{@w{U @var{n} @var{name} @var{code}}}, where\n\ 2475@var{name} is the name used for the type qualifier in source code,\n\ 2476@var{n} is the length of @var{name} as above, and @var{code} is the\n\ 2477code used to represent the unqualified version of this type. (See\n\ 2478@code{write_builtin_type} in @file{cp/mangle.c} for the list of\n\ 2479codes.) In both cases the spaces are for clarity; do not include any\n\ 2480spaces in your string.\n\ 2481\n\ 2482This hook is applied to types prior to typedef resolution. If the mangled\n\ 2483name for a particular type depends only on that type's main variant, you\n\ 2484can perform typedef resolution yourself using @code{TYPE_MAIN_VARIANT}\n\ 2485before mangling.\n\ 2486\n\ 2487The default version of this hook always returns @code{NULL}, which is\n\ 2488appropriate for a target that does not define any new fundamental\n\ 2489types.", 2490 const char *, (const_tree type), 2491 hook_constcharptr_const_tree_null) 2492 2493/* Make any adjustments to libfunc names needed for this target. */ 2494DEFHOOK 2495(init_libfuncs, 2496 "This hook should declare additional library routines or rename\n\ 2497existing ones, using the functions @code{set_optab_libfunc} and\n\ 2498@code{init_one_libfunc} defined in @file{optabs.c}.\n\ 2499@code{init_optabs} calls this macro after initializing all the normal\n\ 2500library routines.\n\ 2501\n\ 2502The default is to do nothing. Most ports don't need to define this hook.", 2503 void, (void), 2504 hook_void_void) 2505 2506 /* Add a __gnu_ prefix to library functions rather than just __. */ 2507DEFHOOKPOD 2508(libfunc_gnu_prefix, 2509 "If false (the default), internal library routines start with two\n\ 2510underscores. If set to true, these routines start with @code{__gnu_}\n\ 2511instead. E.g., @code{__muldi3} changes to @code{__gnu_muldi3}. This\n\ 2512currently only affects functions defined in @file{libgcc2.c}. If this\n\ 2513is set to true, the @file{tm.h} file must also\n\ 2514@code{#define LIBGCC2_GNU_PREFIX}.", 2515 bool, false) 2516 2517/* Given a decl, a section name, and whether the decl initializer 2518 has relocs, choose attributes for the section. */ 2519/* ??? Should be merged with SELECT_SECTION and UNIQUE_SECTION. */ 2520DEFHOOK 2521(section_type_flags, 2522 "Choose a set of section attributes for use by @code{TARGET_ASM_NAMED_SECTION}\n\ 2523based on a variable or function decl, a section name, and whether or not the\n\ 2524declaration's initializer may contain runtime relocations. @var{decl} may be\n\ 2525null, in which case read-write data should be assumed.\n\ 2526\n\ 2527The default version of this function handles choosing code vs data,\n\ 2528read-only vs read-write data, and @code{flag_pic}. You should only\n\ 2529need to override this if your target has special flags that might be\n\ 2530set via @code{__attribute__}.", 2531 unsigned int, (tree decl, const char *name, int reloc), 2532 default_section_type_flags) 2533 2534DEFHOOK 2535(libc_has_function, 2536 "This hook determines whether a function from a class of functions\n\ 2537@var{fn_class} is present at the runtime.", 2538 bool, (enum function_class fn_class), 2539 default_libc_has_function) 2540 2541/* True if new jumps cannot be created, to replace existing ones or 2542 not, at the current point in the compilation. */ 2543DEFHOOK 2544(cannot_modify_jumps_p, 2545 "This target hook returns @code{true} past the point in which new jump\n\ 2546instructions could be created. On machines that require a register for\n\ 2547every jump such as the SHmedia ISA of SH5, this point would typically be\n\ 2548reload, so this target hook should be defined to a function such as:\n\ 2549\n\ 2550@smallexample\n\ 2551static bool\n\ 2552cannot_modify_jumps_past_reload_p ()\n\ 2553@{\n\ 2554 return (reload_completed || reload_in_progress);\n\ 2555@}\n\ 2556@end smallexample", 2557 bool, (void), 2558 hook_bool_void_false) 2559 2560/* True if FOLLOWER may be modified to follow FOLLOWEE. */ 2561DEFHOOK 2562(can_follow_jump, 2563 "FOLLOWER and FOLLOWEE are JUMP_INSN instructions;\ 2564 return true if FOLLOWER may be modified to follow FOLLOWEE;\ 2565 false, if it can't.\ 2566 For example, on some targets, certain kinds of branches can't be made to\ 2567 follow through a hot/cold partitioning.", 2568 bool, (const rtx_insn *follower, const rtx_insn *followee), 2569 hook_bool_const_rtx_insn_const_rtx_insn_true) 2570 2571/* Return a register class for which branch target register 2572 optimizations should be applied. */ 2573DEFHOOK 2574(branch_target_register_class, 2575 "This target hook returns a register class for which branch target register\n\ 2576optimizations should be applied. All registers in this class should be\n\ 2577usable interchangeably. After reload, registers in this class will be\n\ 2578re-allocated and loads will be hoisted out of loops and be subjected\n\ 2579to inter-block scheduling.", 2580 reg_class_t, (void), 2581 default_branch_target_register_class) 2582 2583/* Return true if branch target register optimizations should include 2584 callee-saved registers that are not already live during the current 2585 function. AFTER_PE_GEN is true if prologues and epilogues have 2586 already been generated. */ 2587DEFHOOK 2588(branch_target_register_callee_saved, 2589 "Branch target register optimization will by default exclude callee-saved\n\ 2590registers\n\ 2591that are not already live during the current function; if this target hook\n\ 2592returns true, they will be included. The target code must than make sure\n\ 2593that all target registers in the class returned by\n\ 2594@samp{TARGET_BRANCH_TARGET_REGISTER_CLASS} that might need saving are\n\ 2595saved. @var{after_prologue_epilogue_gen} indicates if prologues and\n\ 2596epilogues have already been generated. Note, even if you only return\n\ 2597true when @var{after_prologue_epilogue_gen} is false, you still are likely\n\ 2598to have to make special provisions in @code{INITIAL_ELIMINATION_OFFSET}\n\ 2599to reserve space for caller-saved target registers.", 2600 bool, (bool after_prologue_epilogue_gen), 2601 hook_bool_bool_false) 2602 2603/* Return true if the target supports conditional execution. */ 2604DEFHOOK 2605(have_conditional_execution, 2606 "This target hook returns true if the target supports conditional execution.\n\ 2607This target hook is required only when the target has several different\n\ 2608modes and they have different conditional execution capability, such as ARM.", 2609 bool, (void), 2610 default_have_conditional_execution) 2611 2612DEFHOOK 2613(gen_ccmp_first, 2614 "This function prepares to emit a comparison insn for the first compare in a\n\ 2615 sequence of conditional comparisions. It returns an appropriate comparison\n\ 2616 with @code{CC} for passing to @code{gen_ccmp_next} or @code{cbranch_optab}.\n\ 2617 The insns to prepare the compare are saved in @var{prep_seq} and the compare\n\ 2618 insns are saved in @var{gen_seq}. They will be emitted when all the\n\ 2619 compares in the the conditional comparision are generated without error.\n\ 2620 @var{code} is the @code{rtx_code} of the compare for @var{op0} and @var{op1}.", 2621 rtx, (rtx *prep_seq, rtx *gen_seq, int code, tree op0, tree op1), 2622 NULL) 2623 2624DEFHOOK 2625(gen_ccmp_next, 2626 "This function prepares to emit a conditional comparison within a sequence\n\ 2627 of conditional comparisons. It returns an appropriate comparison with\n\ 2628 @code{CC} for passing to @code{gen_ccmp_next} or @code{cbranch_optab}.\n\ 2629 The insns to prepare the compare are saved in @var{prep_seq} and the compare\n\ 2630 insns are saved in @var{gen_seq}. They will be emitted when all the\n\ 2631 compares in the conditional comparision are generated without error. The\n\ 2632 @var{prev} expression is the result of a prior call to @code{gen_ccmp_first}\n\ 2633 or @code{gen_ccmp_next}. It may return @code{NULL} if the combination of\n\ 2634 @var{prev} and this comparison is not supported, otherwise the result must\n\ 2635 be appropriate for passing to @code{gen_ccmp_next} or @code{cbranch_optab}.\n\ 2636 @var{code} is the @code{rtx_code} of the compare for @var{op0} and @var{op1}.\n\ 2637 @var{bit_code} is @code{AND} or @code{IOR}, which is the op on the compares.", 2638 rtx, (rtx *prep_seq, rtx *gen_seq, rtx prev, int cmp_code, tree op0, tree op1, int bit_code), 2639 NULL) 2640 2641/* Return a new value for loop unroll size. */ 2642DEFHOOK 2643(loop_unroll_adjust, 2644 "This target hook returns a new value for the number of times @var{loop}\n\ 2645should be unrolled. The parameter @var{nunroll} is the number of times\n\ 2646the loop is to be unrolled. The parameter @var{loop} is a pointer to\n\ 2647the loop, which is going to be checked for unrolling. This target hook\n\ 2648is required only when the target has special constraints like maximum\n\ 2649number of memory accesses.", 2650 unsigned, (unsigned nunroll, struct loop *loop), 2651 NULL) 2652 2653/* True if X is a legitimate MODE-mode immediate operand. */ 2654DEFHOOK 2655(legitimate_constant_p, 2656 "This hook returns true if @var{x} is a legitimate constant for a\n\ 2657@var{mode}-mode immediate operand on the target machine. You can assume that\n\ 2658@var{x} satisfies @code{CONSTANT_P}, so you need not check this.\n\ 2659\n\ 2660The default definition returns true.", 2661 bool, (machine_mode mode, rtx x), 2662 hook_bool_mode_rtx_true) 2663 2664/* True if the constant X cannot be placed in the constant pool. */ 2665DEFHOOK 2666(cannot_force_const_mem, 2667 "This hook should return true if @var{x} is of a form that cannot (or\n\ 2668should not) be spilled to the constant pool. @var{mode} is the mode\n\ 2669of @var{x}.\n\ 2670\n\ 2671The default version of this hook returns false.\n\ 2672\n\ 2673The primary reason to define this hook is to prevent reload from\n\ 2674deciding that a non-legitimate constant would be better reloaded\n\ 2675from the constant pool instead of spilling and reloading a register\n\ 2676holding the constant. This restriction is often true of addresses\n\ 2677of TLS symbols for various targets.", 2678 bool, (machine_mode mode, rtx x), 2679 hook_bool_mode_rtx_false) 2680 2681DEFHOOK_UNDOC 2682(cannot_copy_insn_p, 2683 "True if the insn @var{x} cannot be duplicated.", 2684 bool, (rtx_insn *), NULL) 2685 2686/* True if X is considered to be commutative. */ 2687DEFHOOK 2688(commutative_p, 2689 "This target hook returns @code{true} if @var{x} is considered to be commutative.\n\ 2690Usually, this is just COMMUTATIVE_P (@var{x}), but the HP PA doesn't consider\n\ 2691PLUS to be commutative inside a MEM@. @var{outer_code} is the rtx code\n\ 2692of the enclosing rtl, if known, otherwise it is UNKNOWN.", 2693 bool, (const_rtx x, int outer_code), 2694 hook_bool_const_rtx_commutative_p) 2695 2696/* True if ADDR is an address-expression whose effect depends 2697 on the mode of the memory reference it is used in. */ 2698DEFHOOK 2699(mode_dependent_address_p, 2700 "This hook returns @code{true} if memory address @var{addr} in address\n\ 2701space @var{addrspace} can have\n\ 2702different meanings depending on the machine mode of the memory\n\ 2703reference it is used for or if the address is valid for some modes\n\ 2704but not others.\n\ 2705\n\ 2706Autoincrement and autodecrement addresses typically have mode-dependent\n\ 2707effects because the amount of the increment or decrement is the size\n\ 2708of the operand being addressed. Some machines have other mode-dependent\n\ 2709addresses. Many RISC machines have no mode-dependent addresses.\n\ 2710\n\ 2711You may assume that @var{addr} is a valid address for the machine.\n\ 2712\n\ 2713The default version of this hook returns @code{false}.", 2714 bool, (const_rtx addr, addr_space_t addrspace), 2715 default_mode_dependent_address_p) 2716 2717/* Given an invalid address X for a given machine mode, try machine-specific 2718 ways to make it legitimate. Return X or an invalid address on failure. */ 2719DEFHOOK 2720(legitimize_address, 2721 "This hook is given an invalid memory address @var{x} for an\n\ 2722operand of mode @var{mode} and should try to return a valid memory\n\ 2723address.\n\ 2724\n\ 2725@findex break_out_memory_refs\n\ 2726@var{x} will always be the result of a call to @code{break_out_memory_refs},\n\ 2727and @var{oldx} will be the operand that was given to that function to produce\n\ 2728@var{x}.\n\ 2729\n\ 2730The code of the hook should not alter the substructure of\n\ 2731@var{x}. If it transforms @var{x} into a more legitimate form, it\n\ 2732should return the new @var{x}.\n\ 2733\n\ 2734It is not necessary for this hook to come up with a legitimate address,\n\ 2735with the exception of native TLS addresses (@pxref{Emulated TLS}).\n\ 2736The compiler has standard ways of doing so in all cases. In fact, if\n\ 2737the target supports only emulated TLS, it\n\ 2738is safe to omit this hook or make it return @var{x} if it cannot find\n\ 2739a valid way to legitimize the address. But often a machine-dependent\n\ 2740strategy can generate better code.", 2741 rtx, (rtx x, rtx oldx, machine_mode mode), 2742 default_legitimize_address) 2743 2744/* Given an address RTX, undo the effects of LEGITIMIZE_ADDRESS. */ 2745DEFHOOK 2746(delegitimize_address, 2747 "This hook is used to undo the possibly obfuscating effects of the\n\ 2748@code{LEGITIMIZE_ADDRESS} and @code{LEGITIMIZE_RELOAD_ADDRESS} target\n\ 2749macros. Some backend implementations of these macros wrap symbol\n\ 2750references inside an @code{UNSPEC} rtx to represent PIC or similar\n\ 2751addressing modes. This target hook allows GCC's optimizers to understand\n\ 2752the semantics of these opaque @code{UNSPEC}s by converting them back\n\ 2753into their original form.", 2754 rtx, (rtx x), 2755 delegitimize_mem_from_attrs) 2756 2757/* Given an RTX, return true if it is not ok to emit it into debug info 2758 section. */ 2759DEFHOOK 2760(const_not_ok_for_debug_p, 2761 "This hook should return true if @var{x} should not be emitted into\n\ 2762debug sections.", 2763 bool, (rtx x), 2764 hook_bool_rtx_false) 2765 2766/* Given an address RTX, say whether it is valid. */ 2767DEFHOOK 2768(legitimate_address_p, 2769 "A function that returns whether @var{x} (an RTX) is a legitimate memory\n\ 2770address on the target machine for a memory operand of mode @var{mode}.\n\ 2771\n\ 2772Legitimate addresses are defined in two variants: a strict variant and a\n\ 2773non-strict one. The @var{strict} parameter chooses which variant is\n\ 2774desired by the caller.\n\ 2775\n\ 2776The strict variant is used in the reload pass. It must be defined so\n\ 2777that any pseudo-register that has not been allocated a hard register is\n\ 2778considered a memory reference. This is because in contexts where some\n\ 2779kind of register is required, a pseudo-register with no hard register\n\ 2780must be rejected. For non-hard registers, the strict variant should look\n\ 2781up the @code{reg_renumber} array; it should then proceed using the hard\n\ 2782register number in the array, or treat the pseudo as a memory reference\n\ 2783if the array holds @code{-1}.\n\ 2784\n\ 2785The non-strict variant is used in other passes. It must be defined to\n\ 2786accept all pseudo-registers in every context where some kind of\n\ 2787register is required.\n\ 2788\n\ 2789Normally, constant addresses which are the sum of a @code{symbol_ref}\n\ 2790and an integer are stored inside a @code{const} RTX to mark them as\n\ 2791constant. Therefore, there is no need to recognize such sums\n\ 2792specifically as legitimate addresses. Normally you would simply\n\ 2793recognize any @code{const} as legitimate.\n\ 2794\n\ 2795Usually @code{PRINT_OPERAND_ADDRESS} is not prepared to handle constant\n\ 2796sums that are not marked with @code{const}. It assumes that a naked\n\ 2797@code{plus} indicates indexing. If so, then you @emph{must} reject such\n\ 2798naked constant sums as illegitimate addresses, so that none of them will\n\ 2799be given to @code{PRINT_OPERAND_ADDRESS}.\n\ 2800\n\ 2801@cindex @code{TARGET_ENCODE_SECTION_INFO} and address validation\n\ 2802On some machines, whether a symbolic address is legitimate depends on\n\ 2803the section that the address refers to. On these machines, define the\n\ 2804target hook @code{TARGET_ENCODE_SECTION_INFO} to store the information\n\ 2805into the @code{symbol_ref}, and then check for it here. When you see a\n\ 2806@code{const}, you will have to look inside it to find the\n\ 2807@code{symbol_ref} in order to determine the section. @xref{Assembler\n\ 2808Format}.\n\ 2809\n\ 2810@cindex @code{GO_IF_LEGITIMATE_ADDRESS}\n\ 2811Some ports are still using a deprecated legacy substitute for\n\ 2812this hook, the @code{GO_IF_LEGITIMATE_ADDRESS} macro. This macro\n\ 2813has this syntax:\n\ 2814\n\ 2815@example\n\ 2816#define GO_IF_LEGITIMATE_ADDRESS (@var{mode}, @var{x}, @var{label})\n\ 2817@end example\n\ 2818\n\ 2819@noindent\n\ 2820and should @code{goto @var{label}} if the address @var{x} is a valid\n\ 2821address on the target machine for a memory operand of mode @var{mode}.\n\ 2822\n\ 2823@findex REG_OK_STRICT\n\ 2824Compiler source files that want to use the strict variant of this\n\ 2825macro define the macro @code{REG_OK_STRICT}. You should use an\n\ 2826@code{#ifdef REG_OK_STRICT} conditional to define the strict variant in\n\ 2827that case and the non-strict variant otherwise.\n\ 2828\n\ 2829Using the hook is usually simpler because it limits the number of\n\ 2830files that are recompiled when changes are made.", 2831 bool, (machine_mode mode, rtx x, bool strict), 2832 default_legitimate_address_p) 2833 2834/* True if the given constant can be put into an object_block. */ 2835DEFHOOK 2836(use_blocks_for_constant_p, 2837 "This hook should return true if pool entries for constant @var{x} can\n\ 2838be placed in an @code{object_block} structure. @var{mode} is the mode\n\ 2839of @var{x}.\n\ 2840\n\ 2841The default version returns false for all constants.", 2842 bool, (machine_mode mode, const_rtx x), 2843 hook_bool_mode_const_rtx_false) 2844 2845/* True if the given decl can be put into an object_block. */ 2846DEFHOOK 2847(use_blocks_for_decl_p, 2848 "This hook should return true if pool entries for @var{decl} should\n\ 2849be placed in an @code{object_block} structure.\n\ 2850\n\ 2851The default version returns true for all decls.", 2852 bool, (const_tree decl), 2853 hook_bool_const_tree_true) 2854 2855/* The minimum and maximum byte offsets for anchored addresses. */ 2856DEFHOOKPOD 2857(min_anchor_offset, 2858 "The minimum offset that should be applied to a section anchor.\n\ 2859On most targets, it should be the smallest offset that can be\n\ 2860applied to a base register while still giving a legitimate address\n\ 2861for every mode. The default value is 0.", 2862 HOST_WIDE_INT, 0) 2863 2864DEFHOOKPOD 2865(max_anchor_offset, 2866 "Like @code{TARGET_MIN_ANCHOR_OFFSET}, but the maximum (inclusive)\n\ 2867offset that should be applied to section anchors. The default\n\ 2868value is 0.", 2869 HOST_WIDE_INT, 0) 2870 2871/* True if section anchors can be used to access the given symbol. */ 2872DEFHOOK 2873(use_anchors_for_symbol_p, 2874 "Return true if GCC should attempt to use anchors to access @code{SYMBOL_REF}\n\ 2875@var{x}. You can assume @samp{SYMBOL_REF_HAS_BLOCK_INFO_P (@var{x})} and\n\ 2876@samp{!SYMBOL_REF_ANCHOR_P (@var{x})}.\n\ 2877\n\ 2878The default version is correct for most targets, but you might need to\n\ 2879intercept this hook to handle things like target-specific attributes\n\ 2880or target-specific sections.", 2881 bool, (const_rtx x), 2882 default_use_anchors_for_symbol_p) 2883 2884/* True if target supports indirect functions. */ 2885DEFHOOK 2886(has_ifunc_p, 2887 "It returns true if the target supports GNU indirect functions.\n\ 2888The support includes the assembler, linker and dynamic linker.\n\ 2889The default value of this hook is based on target's libc.", 2890 bool, (void), 2891 default_has_ifunc_p) 2892 2893/* True if it is OK to do sibling call optimization for the specified 2894 call expression EXP. DECL will be the called function, or NULL if 2895 this is an indirect call. */ 2896DEFHOOK 2897(function_ok_for_sibcall, 2898 "True if it is OK to do sibling call optimization for the specified\n\ 2899call expression @var{exp}. @var{decl} will be the called function,\n\ 2900or @code{NULL} if this is an indirect call.\n\ 2901\n\ 2902It is not uncommon for limitations of calling conventions to prevent\n\ 2903tail calls to functions outside the current unit of translation, or\n\ 2904during PIC compilation. The hook is used to enforce these restrictions,\n\ 2905as the @code{sibcall} md pattern can not fail, or fall over to a\n\ 2906``normal'' call. The criteria for successful sibling call optimization\n\ 2907may vary greatly between different architectures.", 2908 bool, (tree decl, tree exp), 2909 hook_bool_tree_tree_false) 2910 2911/* Establish appropriate back-end context for processing the function 2912 FNDECL. The argument might be NULL to indicate processing at top 2913 level, outside of any function scope. */ 2914DEFHOOK 2915(set_current_function, 2916 "The compiler invokes this hook whenever it changes its current function\n\ 2917context (@code{cfun}). You can define this function if\n\ 2918the back end needs to perform any initialization or reset actions on a\n\ 2919per-function basis. For example, it may be used to implement function\n\ 2920attributes that affect register usage or code generation patterns.\n\ 2921The argument @var{decl} is the declaration for the new function context,\n\ 2922and may be null to indicate that the compiler has left a function context\n\ 2923and is returning to processing at the top level.\n\ 2924The default hook function does nothing.\n\ 2925\n\ 2926GCC sets @code{cfun} to a dummy function context during initialization of\n\ 2927some parts of the back end. The hook function is not invoked in this\n\ 2928situation; you need not worry about the hook being invoked recursively,\n\ 2929or when the back end is in a partially-initialized state.\n\ 2930@code{cfun} might be @code{NULL} to indicate processing at top level,\n\ 2931outside of any function scope.", 2932 void, (tree decl), hook_void_tree) 2933 2934/* True if EXP should be placed in a "small data" section. */ 2935DEFHOOK 2936(in_small_data_p, 2937 "Returns true if @var{exp} should be placed into a ``small data'' section.\n\ 2938The default version of this hook always returns false.", 2939 bool, (const_tree exp), 2940 hook_bool_const_tree_false) 2941 2942/* True if EXP names an object for which name resolution must resolve 2943 to the current executable or shared library. */ 2944DEFHOOK 2945(binds_local_p, 2946 "Returns true if @var{exp} names an object for which name resolution\n\ 2947rules must resolve to the current ``module'' (dynamic shared library\n\ 2948or executable image).\n\ 2949\n\ 2950The default version of this hook implements the name resolution rules\n\ 2951for ELF, which has a looser model of global name binding than other\n\ 2952currently supported object file formats.", 2953 bool, (const_tree exp), 2954 default_binds_local_p) 2955 2956/* Check if profiling code is before or after prologue. */ 2957DEFHOOK 2958(profile_before_prologue, 2959 "It returns true if target wants profile code emitted before prologue.\n\n\ 2960The default version of this hook use the target macro\n\ 2961@code{PROFILE_BEFORE_PROLOGUE}.", 2962 bool, (void), 2963 default_profile_before_prologue) 2964 2965/* Return true if a leaf function should stay leaf even with profiling 2966 enabled. */ 2967DEFHOOK 2968(keep_leaf_when_profiled, 2969 "This target hook returns true if the target wants the leaf flag for\ 2970 the current function to stay true even if it calls mcount. This might\ 2971 make sense for targets using the leaf flag only to determine whether a\ 2972 stack frame needs to be generated or not and for which the call to\ 2973 mcount is generated before the function prologue.", 2974 bool, (void), 2975 default_keep_leaf_when_profiled) 2976 2977/* Modify and return the identifier of a DECL's external name, 2978 originally identified by ID, as required by the target, 2979 (eg, append @nn to windows32 stdcall function names). 2980 The default is to return ID without modification. */ 2981DEFHOOK 2982(mangle_decl_assembler_name, 2983 "Define this hook if you need to postprocess the assembler name generated\n\ 2984by target-independent code. The @var{id} provided to this hook will be\n\ 2985the computed name (e.g., the macro @code{DECL_NAME} of the @var{decl} in C,\n\ 2986or the mangled name of the @var{decl} in C++). The return value of the\n\ 2987hook is an @code{IDENTIFIER_NODE} for the appropriate mangled name on\n\ 2988your target system. The default implementation of this hook just\n\ 2989returns the @var{id} provided.", 2990 tree, (tree decl, tree id), 2991 default_mangle_decl_assembler_name) 2992 2993/* Do something target-specific to record properties of the DECL into 2994 the associated SYMBOL_REF. */ 2995DEFHOOK 2996(encode_section_info, 2997 "Define this hook if references to a symbol or a constant must be\n\ 2998treated differently depending on something about the variable or\n\ 2999function named by the symbol (such as what section it is in).\n\ 3000\n\ 3001The hook is executed immediately after rtl has been created for\n\ 3002@var{decl}, which may be a variable or function declaration or\n\ 3003an entry in the constant pool. In either case, @var{rtl} is the\n\ 3004rtl in question. Do @emph{not} use @code{DECL_RTL (@var{decl})}\n\ 3005in this hook; that field may not have been initialized yet.\n\ 3006\n\ 3007In the case of a constant, it is safe to assume that the rtl is\n\ 3008a @code{mem} whose address is a @code{symbol_ref}. Most decls\n\ 3009will also have this form, but that is not guaranteed. Global\n\ 3010register variables, for instance, will have a @code{reg} for their\n\ 3011rtl. (Normally the right thing to do with such unusual rtl is\n\ 3012leave it alone.)\n\ 3013\n\ 3014The @var{new_decl_p} argument will be true if this is the first time\n\ 3015that @code{TARGET_ENCODE_SECTION_INFO} has been invoked on this decl. It will\n\ 3016be false for subsequent invocations, which will happen for duplicate\n\ 3017declarations. Whether or not anything must be done for the duplicate\n\ 3018declaration depends on whether the hook examines @code{DECL_ATTRIBUTES}.\n\ 3019@var{new_decl_p} is always true when the hook is called for a constant.\n\ 3020\n\ 3021@cindex @code{SYMBOL_REF_FLAG}, in @code{TARGET_ENCODE_SECTION_INFO}\n\ 3022The usual thing for this hook to do is to record flags in the\n\ 3023@code{symbol_ref}, using @code{SYMBOL_REF_FLAG} or @code{SYMBOL_REF_FLAGS}.\n\ 3024Historically, the name string was modified if it was necessary to\n\ 3025encode more than one bit of information, but this practice is now\n\ 3026discouraged; use @code{SYMBOL_REF_FLAGS}.\n\ 3027\n\ 3028The default definition of this hook, @code{default_encode_section_info}\n\ 3029in @file{varasm.c}, sets a number of commonly-useful bits in\n\ 3030@code{SYMBOL_REF_FLAGS}. Check whether the default does what you need\n\ 3031before overriding it.", 3032 void, (tree decl, rtx rtl, int new_decl_p), 3033 default_encode_section_info) 3034 3035/* Undo the effects of encode_section_info on the symbol string. */ 3036DEFHOOK 3037(strip_name_encoding, 3038 "Decode @var{name} and return the real name part, sans\n\ 3039the characters that @code{TARGET_ENCODE_SECTION_INFO}\n\ 3040may have added.", 3041 const char *, (const char *name), 3042 default_strip_name_encoding) 3043 3044/* If shift optabs for MODE are known to always truncate the shift count, 3045 return the mask that they apply. Return 0 otherwise. */ 3046DEFHOOK 3047(shift_truncation_mask, 3048 "This function describes how the standard shift patterns for @var{mode}\n\ 3049deal with shifts by negative amounts or by more than the width of the mode.\n\ 3050@xref{shift patterns}.\n\ 3051\n\ 3052On many machines, the shift patterns will apply a mask @var{m} to the\n\ 3053shift count, meaning that a fixed-width shift of @var{x} by @var{y} is\n\ 3054equivalent to an arbitrary-width shift of @var{x} by @var{y & m}. If\n\ 3055this is true for mode @var{mode}, the function should return @var{m},\n\ 3056otherwise it should return 0. A return value of 0 indicates that no\n\ 3057particular behavior is guaranteed.\n\ 3058\n\ 3059Note that, unlike @code{SHIFT_COUNT_TRUNCATED}, this function does\n\ 3060@emph{not} apply to general shift rtxes; it applies only to instructions\n\ 3061that are generated by the named shift patterns.\n\ 3062\n\ 3063The default implementation of this function returns\n\ 3064@code{GET_MODE_BITSIZE (@var{mode}) - 1} if @code{SHIFT_COUNT_TRUNCATED}\n\ 3065and 0 otherwise. This definition is always safe, but if\n\ 3066@code{SHIFT_COUNT_TRUNCATED} is false, and some shift patterns\n\ 3067nevertheless truncate the shift count, you may get better code\n\ 3068by overriding it.", 3069 unsigned HOST_WIDE_INT, (machine_mode mode), 3070 default_shift_truncation_mask) 3071 3072/* Return the number of divisions in the given MODE that should be present, 3073 so that it is profitable to turn the division into a multiplication by 3074 the reciprocal. */ 3075DEFHOOK 3076(min_divisions_for_recip_mul, 3077 "When @option{-ffast-math} is in effect, GCC tries to optimize\n\ 3078divisions by the same divisor, by turning them into multiplications by\n\ 3079the reciprocal. This target hook specifies the minimum number of divisions\n\ 3080that should be there for GCC to perform the optimization for a variable\n\ 3081of mode @var{mode}. The default implementation returns 3 if the machine\n\ 3082has an instruction for the division, and 2 if it does not.", 3083 unsigned int, (machine_mode mode), 3084 default_min_divisions_for_recip_mul) 3085 3086/* If the representation of integral MODE is such that values are 3087 always sign-extended to a wider mode MODE_REP then return 3088 SIGN_EXTEND. Return UNKNOWN otherwise. */ 3089/* Note that the return type ought to be RTX_CODE, but that's not 3090 necessarily defined at this point. */ 3091DEFHOOK 3092(mode_rep_extended, 3093 "The representation of an integral mode can be such that the values\n\ 3094are always extended to a wider integral mode. Return\n\ 3095@code{SIGN_EXTEND} if values of @var{mode} are represented in\n\ 3096sign-extended form to @var{rep_mode}. Return @code{UNKNOWN}\n\ 3097otherwise. (Currently, none of the targets use zero-extended\n\ 3098representation this way so unlike @code{LOAD_EXTEND_OP},\n\ 3099@code{TARGET_MODE_REP_EXTENDED} is expected to return either\n\ 3100@code{SIGN_EXTEND} or @code{UNKNOWN}. Also no target extends\n\ 3101@var{mode} to @var{rep_mode} so that @var{rep_mode} is not the next\n\ 3102widest integral mode and currently we take advantage of this fact.)\n\ 3103\n\ 3104Similarly to @code{LOAD_EXTEND_OP} you may return a non-@code{UNKNOWN}\n\ 3105value even if the extension is not performed on certain hard registers\n\ 3106as long as for the @code{REGNO_REG_CLASS} of these hard registers\n\ 3107@code{CANNOT_CHANGE_MODE_CLASS} returns nonzero.\n\ 3108\n\ 3109Note that @code{TARGET_MODE_REP_EXTENDED} and @code{LOAD_EXTEND_OP}\n\ 3110describe two related properties. If you define\n\ 3111@code{TARGET_MODE_REP_EXTENDED (mode, word_mode)} you probably also want\n\ 3112to define @code{LOAD_EXTEND_OP (mode)} to return the same type of\n\ 3113extension.\n\ 3114\n\ 3115In order to enforce the representation of @code{mode},\n\ 3116@code{TRULY_NOOP_TRUNCATION} should return false when truncating to\n\ 3117@code{mode}.", 3118 int, (machine_mode mode, machine_mode rep_mode), 3119 default_mode_rep_extended) 3120 3121/* True if MODE is valid for a pointer in __attribute__((mode("MODE"))). */ 3122DEFHOOK 3123(valid_pointer_mode, 3124 "Define this to return nonzero if the port can handle pointers\n\ 3125with machine mode @var{mode}. The default version of this\n\ 3126hook returns true for both @code{ptr_mode} and @code{Pmode}.", 3127 bool, (machine_mode mode), 3128 default_valid_pointer_mode) 3129 3130/* Disambiguate with errno. */ 3131DEFHOOK 3132(ref_may_alias_errno, 3133 "Define this to return nonzero if the memory reference @var{ref}\ 3134 may alias with the system C library errno location. The default\ 3135 version of this hook assumes the system C library errno location\ 3136 is either a declaration of type int or accessed by dereferencing\ 3137 a pointer to int.", 3138 bool, (struct ao_ref *ref), 3139 default_ref_may_alias_errno) 3140 3141/* Support for named address spaces. */ 3142#undef HOOK_PREFIX 3143#define HOOK_PREFIX "TARGET_ADDR_SPACE_" 3144HOOK_VECTOR (TARGET_ADDR_SPACE_HOOKS, addr_space) 3145 3146/* MODE to use for a pointer into another address space. */ 3147DEFHOOK 3148(pointer_mode, 3149 "Define this to return the machine mode to use for pointers to\n\ 3150@var{address_space} if the target supports named address spaces.\n\ 3151The default version of this hook returns @code{ptr_mode}.", 3152 machine_mode, (addr_space_t address_space), 3153 default_addr_space_pointer_mode) 3154 3155/* MODE to use for an address in another address space. */ 3156DEFHOOK 3157(address_mode, 3158 "Define this to return the machine mode to use for addresses in\n\ 3159@var{address_space} if the target supports named address spaces.\n\ 3160The default version of this hook returns @code{Pmode}.", 3161 machine_mode, (addr_space_t address_space), 3162 default_addr_space_address_mode) 3163 3164/* True if MODE is valid for a pointer in __attribute__((mode("MODE"))) 3165 in another address space. */ 3166DEFHOOK 3167(valid_pointer_mode, 3168 "Define this to return nonzero if the port can handle pointers\n\ 3169with machine mode @var{mode} to address space @var{as}. This target\n\ 3170hook is the same as the @code{TARGET_VALID_POINTER_MODE} target hook,\n\ 3171except that it includes explicit named address space support. The default\n\ 3172version of this hook returns true for the modes returned by either the\n\ 3173@code{TARGET_ADDR_SPACE_POINTER_MODE} or @code{TARGET_ADDR_SPACE_ADDRESS_MODE}\n\ 3174target hooks for the given address space.", 3175 bool, (machine_mode mode, addr_space_t as), 3176 default_addr_space_valid_pointer_mode) 3177 3178/* True if an address is a valid memory address to a given named address 3179 space for a given mode. */ 3180DEFHOOK 3181(legitimate_address_p, 3182 "Define this to return true if @var{exp} is a valid address for mode\n\ 3183@var{mode} in the named address space @var{as}. The @var{strict}\n\ 3184parameter says whether strict addressing is in effect after reload has\n\ 3185finished. This target hook is the same as the\n\ 3186@code{TARGET_LEGITIMATE_ADDRESS_P} target hook, except that it includes\n\ 3187explicit named address space support.", 3188 bool, (machine_mode mode, rtx exp, bool strict, addr_space_t as), 3189 default_addr_space_legitimate_address_p) 3190 3191/* Return an updated address to convert an invalid pointer to a named 3192 address space to a valid one. If NULL_RTX is returned use machine 3193 independent methods to make the address valid. */ 3194DEFHOOK 3195(legitimize_address, 3196 "Define this to modify an invalid address @var{x} to be a valid address\n\ 3197with mode @var{mode} in the named address space @var{as}. This target\n\ 3198hook is the same as the @code{TARGET_LEGITIMIZE_ADDRESS} target hook,\n\ 3199except that it includes explicit named address space support.", 3200 rtx, (rtx x, rtx oldx, machine_mode mode, addr_space_t as), 3201 default_addr_space_legitimize_address) 3202 3203/* True if one named address space is a subset of another named address. */ 3204DEFHOOK 3205(subset_p, 3206 "Define this to return whether the @var{subset} named address space is\n\ 3207contained within the @var{superset} named address space. Pointers to\n\ 3208a named address space that is a subset of another named address space\n\ 3209will be converted automatically without a cast if used together in\n\ 3210arithmetic operations. Pointers to a superset address space can be\n\ 3211converted to pointers to a subset address space via explicit casts.", 3212 bool, (addr_space_t subset, addr_space_t superset), 3213 default_addr_space_subset_p) 3214 3215/* True if 0 is a valid address in the address space, or false if 3216 0 is a NULL in the address space. */ 3217DEFHOOK 3218(zero_address_valid, 3219 "Define this to modify the default handling of address 0 for the\n\ 3220address space. Return true if 0 should be considered a valid address.", 3221 bool, (addr_space_t as), 3222 default_addr_space_zero_address_valid) 3223 3224/* Function to convert an rtl expression from one address space to another. */ 3225DEFHOOK 3226(convert, 3227 "Define this to convert the pointer expression represented by the RTL\n\ 3228@var{op} with type @var{from_type} that points to a named address\n\ 3229space to a new pointer expression with type @var{to_type} that points\n\ 3230to a different named address space. When this hook it called, it is\n\ 3231guaranteed that one of the two address spaces is a subset of the other,\n\ 3232as determined by the @code{TARGET_ADDR_SPACE_SUBSET_P} target hook.", 3233 rtx, (rtx op, tree from_type, tree to_type), 3234 default_addr_space_convert) 3235 3236/* Function to encode an address space into dwarf. */ 3237DEFHOOK 3238(debug, 3239 "Define this to define how the address space is encoded in dwarf.\n\ 3240The result is the value to be used with @code{DW_AT_address_class}.", 3241 int, (addr_space_t as), 3242 default_addr_space_debug) 3243 3244HOOK_VECTOR_END (addr_space) 3245 3246#undef HOOK_PREFIX 3247#define HOOK_PREFIX "TARGET_" 3248 3249/* True if MODE is valid for the target. By "valid", we mean able to 3250 be manipulated in non-trivial ways. In particular, this means all 3251 the arithmetic is supported. */ 3252DEFHOOK 3253(scalar_mode_supported_p, 3254 "Define this to return nonzero if the port is prepared to handle\n\ 3255insns involving scalar mode @var{mode}. For a scalar mode to be\n\ 3256considered supported, all the basic arithmetic and comparisons\n\ 3257must work.\n\ 3258\n\ 3259The default version of this hook returns true for any mode\n\ 3260required to handle the basic C types (as defined by the port).\n\ 3261Included here are the double-word arithmetic supported by the\n\ 3262code in @file{optabs.c}.", 3263 bool, (machine_mode mode), 3264 default_scalar_mode_supported_p) 3265 3266/* Similarly for vector modes. "Supported" here is less strict. At 3267 least some operations are supported; need to check optabs or builtins 3268 for further details. */ 3269DEFHOOK 3270(vector_mode_supported_p, 3271 "Define this to return nonzero if the port is prepared to handle\n\ 3272insns involving vector mode @var{mode}. At the very least, it\n\ 3273must have move patterns for this mode.", 3274 bool, (machine_mode mode), 3275 hook_bool_mode_false) 3276 3277DEFHOOK 3278(vector_alignment, 3279 "This hook can be used to define the alignment for a vector of type\n\ 3280@var{type}, in order to comply with a platform ABI. The default is to\n\ 3281require natural alignment for vector types. The alignment returned by\n\ 3282this hook must be a power-of-two multiple of the default alignment of\n\ 3283the vector element type.", 3284 HOST_WIDE_INT, (const_tree type), 3285 default_vector_alignment) 3286 3287/* True if we should try to use a scalar mode to represent an array, 3288 overriding the usual MAX_FIXED_MODE limit. */ 3289DEFHOOK 3290(array_mode_supported_p, 3291 "Return true if GCC should try to use a scalar mode to store an array\n\ 3292of @var{nelems} elements, given that each element has mode @var{mode}.\n\ 3293Returning true here overrides the usual @code{MAX_FIXED_MODE} limit\n\ 3294and allows GCC to use any defined integer mode.\n\ 3295\n\ 3296One use of this hook is to support vector load and store operations\n\ 3297that operate on several homogeneous vectors. For example, ARM NEON\n\ 3298has operations like:\n\ 3299\n\ 3300@smallexample\n\ 3301int8x8x3_t vld3_s8 (const int8_t *)\n\ 3302@end smallexample\n\ 3303\n\ 3304where the return type is defined as:\n\ 3305\n\ 3306@smallexample\n\ 3307typedef struct int8x8x3_t\n\ 3308@{\n\ 3309 int8x8_t val[3];\n\ 3310@} int8x8x3_t;\n\ 3311@end smallexample\n\ 3312\n\ 3313If this hook allows @code{val} to have a scalar mode, then\n\ 3314@code{int8x8x3_t} can have the same mode. GCC can then store\n\ 3315@code{int8x8x3_t}s in registers rather than forcing them onto the stack.", 3316 bool, (machine_mode mode, unsigned HOST_WIDE_INT nelems), 3317 hook_bool_mode_uhwi_false) 3318 3319DEFHOOK 3320(libgcc_floating_mode_supported_p, 3321 "Define this to return nonzero if libgcc provides support for the \n\ 3322floating-point mode @var{mode}, which is known to pass \n\ 3323@code{TARGET_SCALAR_MODE_SUPPORTED_P}. The default version of this \n\ 3324hook returns true for all of @code{SFmode}, @code{DFmode}, \n\ 3325@code{XFmode} and @code{TFmode}, if such modes exist.", 3326 bool, (machine_mode mode), 3327 default_libgcc_floating_mode_supported_p) 3328 3329/* Compute cost of moving data from a register of class FROM to one of 3330 TO, using MODE. */ 3331DEFHOOK 3332(register_move_cost, 3333 "This target hook should return the cost of moving data of mode @var{mode}\n\ 3334from a register in class @var{from} to one in class @var{to}. The classes\n\ 3335are expressed using the enumeration values such as @code{GENERAL_REGS}.\n\ 3336A value of 2 is the default; other values are interpreted relative to\n\ 3337that.\n\ 3338\n\ 3339It is not required that the cost always equal 2 when @var{from} is the\n\ 3340same as @var{to}; on some machines it is expensive to move between\n\ 3341registers if they are not general registers.\n\ 3342\n\ 3343If reload sees an insn consisting of a single @code{set} between two\n\ 3344hard registers, and if @code{TARGET_REGISTER_MOVE_COST} applied to their\n\ 3345classes returns a value of 2, reload does not check to ensure that the\n\ 3346constraints of the insn are met. Setting a cost of other than 2 will\n\ 3347allow reload to verify that the constraints are met. You should do this\n\ 3348if the @samp{mov@var{m}} pattern's constraints do not allow such copying.\n\ 3349\n\ 3350The default version of this function returns 2.", 3351 int, (machine_mode mode, reg_class_t from, reg_class_t to), 3352 default_register_move_cost) 3353 3354/* Compute cost of moving registers to/from memory. */ 3355/* ??? Documenting the argument types for this hook requires a GFDL 3356 license grant. Also, the documentation uses a different name for RCLASS. */ 3357DEFHOOK 3358(memory_move_cost, 3359 "This target hook should return the cost of moving data of mode @var{mode}\n\ 3360between a register of class @var{rclass} and memory; @var{in} is @code{false}\n\ 3361if the value is to be written to memory, @code{true} if it is to be read in.\n\ 3362This cost is relative to those in @code{TARGET_REGISTER_MOVE_COST}.\n\ 3363If moving between registers and memory is more expensive than between two\n\ 3364registers, you should add this target hook to express the relative cost.\n\ 3365\n\ 3366If you do not add this target hook, GCC uses a default cost of 4 plus\n\ 3367the cost of copying via a secondary reload register, if one is\n\ 3368needed. If your machine requires a secondary reload register to copy\n\ 3369between memory and a register of @var{rclass} but the reload mechanism is\n\ 3370more complex than copying via an intermediate, use this target hook to\n\ 3371reflect the actual cost of the move.\n\ 3372\n\ 3373GCC defines the function @code{memory_move_secondary_cost} if\n\ 3374secondary reloads are needed. It computes the costs due to copying via\n\ 3375a secondary register. If your machine copies from memory using a\n\ 3376secondary register in the conventional way but the default base value of\n\ 33774 is not correct for your machine, use this target hook to add some other\n\ 3378value to the result of that function. The arguments to that function\n\ 3379are the same as to this target hook.", 3380 int, (machine_mode mode, reg_class_t rclass, bool in), 3381 default_memory_move_cost) 3382 3383DEFHOOK 3384(use_by_pieces_infrastructure_p, 3385 "GCC will attempt several strategies when asked to copy between\n\ 3386two areas of memory, or to set, clear or store to memory, for example\n\ 3387when copying a @code{struct}. The @code{by_pieces} infrastructure\n\ 3388implements such memory operations as a sequence of load, store or move\n\ 3389insns. Alternate strategies are to expand the\n\ 3390@code{movmem} or @code{setmem} optabs, to emit a library call, or to emit\n\ 3391unit-by-unit, loop-based operations.\n\ 3392\n\ 3393This target hook should return true if, for a memory operation with a\n\ 3394given @var{size} and @var{alignment}, using the @code{by_pieces}\n\ 3395infrastructure is expected to result in better code generation.\n\ 3396Both @var{size} and @var{alignment} are measured in terms of storage\n\ 3397units.\n\ 3398\n\ 3399The parameter @var{op} is one of: @code{CLEAR_BY_PIECES},\n\ 3400@code{MOVE_BY_PIECES}, @code{SET_BY_PIECES}, @code{STORE_BY_PIECES}.\n\ 3401These describe the type of memory operation under consideration.\n\ 3402\n\ 3403The parameter @var{speed_p} is true if the code is currently being\n\ 3404optimized for speed rather than size.\n\ 3405\n\ 3406Returning true for higher values of @var{size} can improve code generation\n\ 3407for speed if the target does not provide an implementation of the\n\ 3408@code{movmem} or @code{setmem} standard names, if the @code{movmem} or\n\ 3409@code{setmem} implementation would be more expensive than a sequence of\n\ 3410insns, or if the overhead of a library call would dominate that of\n\ 3411the body of the memory operation.\n\ 3412\n\ 3413Returning true for higher values of @code{size} may also cause an increase\n\ 3414in code size, for example where the number of insns emitted to perform a\n\ 3415move would be greater than that of a library call.", 3416 bool, (unsigned HOST_WIDE_INT size, unsigned int alignment, 3417 enum by_pieces_operation op, bool speed_p), 3418 default_use_by_pieces_infrastructure_p) 3419 3420DEFHOOK 3421(optab_supported_p, 3422 "Return true if the optimizers should use optab @var{op} with\n\ 3423modes @var{mode1} and @var{mode2} for optimization type @var{opt_type}.\n\ 3424The optab is known to have an associated @file{.md} instruction\n\ 3425whose C condition is true. @var{mode2} is only meaningful for conversion\n\ 3426optabs; for direct optabs it is a copy of @var{mode1}.\n\ 3427\n\ 3428For example, when called with @var{op} equal to @code{rint_optab} and\n\ 3429@var{mode1} equal to @code{DFmode}, the hook should say whether the\n\ 3430optimizers should use optab @code{rintdf2}.\n\ 3431\n\ 3432The default hook returns true for all inputs.", 3433 bool, (int op, machine_mode mode1, machine_mode mode2, 3434 optimization_type opt_type), 3435 default_optab_supported_p) 3436 3437/* True for MODE if the target expects that registers in this mode will 3438 be allocated to registers in a small register class. The compiler is 3439 allowed to use registers explicitly used in the rtl as spill registers 3440 but it should prevent extending the lifetime of these registers. */ 3441DEFHOOK 3442(small_register_classes_for_mode_p, 3443 "Define this to return nonzero for machine modes for which the port has\n\ 3444small register classes. If this target hook returns nonzero for a given\n\ 3445@var{mode}, the compiler will try to minimize the lifetime of registers\n\ 3446in @var{mode}. The hook may be called with @code{VOIDmode} as argument.\n\ 3447In this case, the hook is expected to return nonzero if it returns nonzero\n\ 3448for any mode.\n\ 3449\n\ 3450On some machines, it is risky to let hard registers live across arbitrary\n\ 3451insns. Typically, these machines have instructions that require values\n\ 3452to be in specific registers (like an accumulator), and reload will fail\n\ 3453if the required hard register is used for another purpose across such an\n\ 3454insn.\n\ 3455\n\ 3456Passes before reload do not know which hard registers will be used\n\ 3457in an instruction, but the machine modes of the registers set or used in\n\ 3458the instruction are already known. And for some machines, register\n\ 3459classes are small for, say, integer registers but not for floating point\n\ 3460registers. For example, the AMD x86-64 architecture requires specific\n\ 3461registers for the legacy x86 integer instructions, but there are many\n\ 3462SSE registers for floating point operations. On such targets, a good\n\ 3463strategy may be to return nonzero from this hook for @code{INTEGRAL_MODE_P}\n\ 3464machine modes but zero for the SSE register classes.\n\ 3465\n\ 3466The default version of this hook returns false for any mode. It is always\n\ 3467safe to redefine this hook to return with a nonzero value. But if you\n\ 3468unnecessarily define it, you will reduce the amount of optimizations\n\ 3469that can be performed in some cases. If you do not define this hook\n\ 3470to return a nonzero value when it is required, the compiler will run out\n\ 3471of spill registers and print a fatal error message.", 3472 bool, (machine_mode mode), 3473 hook_bool_mode_false) 3474 3475/* Register number for a flags register. Only needs to be defined if the 3476 target is constrainted to use post-reload comparison elimination. */ 3477DEFHOOKPOD 3478(flags_regnum, 3479 "If the target has a dedicated flags register, and it needs to use the\ 3480 post-reload comparison elimination pass, then this value should be set\ 3481 appropriately.", 3482 unsigned int, INVALID_REGNUM) 3483 3484/* Compute a (partial) cost for rtx X. Return true if the complete 3485 cost has been computed, and false if subexpressions should be 3486 scanned. In either case, *TOTAL contains the cost result. */ 3487/* Note that OUTER_CODE ought to be RTX_CODE, but that's 3488 not necessarily defined at this point. */ 3489DEFHOOK 3490(rtx_costs, 3491 "This target hook describes the relative costs of RTL expressions.\n\ 3492\n\ 3493The cost may depend on the precise form of the expression, which is\n\ 3494available for examination in @var{x}, and the fact that @var{x} appears\n\ 3495as operand @var{opno} of an expression with rtx code @var{outer_code}.\n\ 3496That is, the hook can assume that there is some rtx @var{y} such\n\ 3497that @samp{GET_CODE (@var{y}) == @var{outer_code}} and such that\n\ 3498either (a) @samp{XEXP (@var{y}, @var{opno}) == @var{x}} or\n\ 3499(b) @samp{XVEC (@var{y}, @var{opno})} contains @var{x}.\n\ 3500\n\ 3501@var{mode} is @var{x}'s machine mode, or for cases like @code{const_int} that\n\ 3502do not have a mode, the mode in which @var{x} is used.\n\ 3503\n\ 3504In implementing this hook, you can use the construct\n\ 3505@code{COSTS_N_INSNS (@var{n})} to specify a cost equal to @var{n} fast\n\ 3506instructions.\n\ 3507\n\ 3508On entry to the hook, @code{*@var{total}} contains a default estimate\n\ 3509for the cost of the expression. The hook should modify this value as\n\ 3510necessary. Traditionally, the default costs are @code{COSTS_N_INSNS (5)}\n\ 3511for multiplications, @code{COSTS_N_INSNS (7)} for division and modulus\n\ 3512operations, and @code{COSTS_N_INSNS (1)} for all other operations.\n\ 3513\n\ 3514When optimizing for code size, i.e.@: when @code{speed} is\n\ 3515false, this target hook should be used to estimate the relative\n\ 3516size cost of an expression, again relative to @code{COSTS_N_INSNS}.\n\ 3517\n\ 3518The hook returns true when all subexpressions of @var{x} have been\n\ 3519processed, and false when @code{rtx_cost} should recurse.", 3520 bool, (rtx x, machine_mode mode, int outer_code, int opno, int *total, bool speed), 3521 hook_bool_rtx_mode_int_int_intp_bool_false) 3522 3523/* Compute the cost of X, used as an address. Never called with 3524 invalid addresses. */ 3525DEFHOOK 3526(address_cost, 3527 "This hook computes the cost of an addressing mode that contains\n\ 3528@var{address}. If not defined, the cost is computed from\n\ 3529the @var{address} expression and the @code{TARGET_RTX_COST} hook.\n\ 3530\n\ 3531For most CISC machines, the default cost is a good approximation of the\n\ 3532true cost of the addressing mode. However, on RISC machines, all\n\ 3533instructions normally have the same length and execution time. Hence\n\ 3534all addresses will have equal costs.\n\ 3535\n\ 3536In cases where more than one form of an address is known, the form with\n\ 3537the lowest cost will be used. If multiple forms have the same, lowest,\n\ 3538cost, the one that is the most complex will be used.\n\ 3539\n\ 3540For example, suppose an address that is equal to the sum of a register\n\ 3541and a constant is used twice in the same basic block. When this macro\n\ 3542is not defined, the address will be computed in a register and memory\n\ 3543references will be indirect through that register. On machines where\n\ 3544the cost of the addressing mode containing the sum is no higher than\n\ 3545that of a simple indirect reference, this will produce an additional\n\ 3546instruction and possibly require an additional register. Proper\n\ 3547specification of this macro eliminates this overhead for such machines.\n\ 3548\n\ 3549This hook is never called with an invalid address.\n\ 3550\n\ 3551On machines where an address involving more than one register is as\n\ 3552cheap as an address computation involving only one register, defining\n\ 3553@code{TARGET_ADDRESS_COST} to reflect this can cause two registers to\n\ 3554be live over a region of code where only one would have been if\n\ 3555@code{TARGET_ADDRESS_COST} were not defined in that manner. This effect\n\ 3556should be considered in the definition of this macro. Equivalent costs\n\ 3557should probably only be given to addresses with different numbers of\n\ 3558registers on machines with lots of registers.", 3559 int, (rtx address, machine_mode mode, addr_space_t as, bool speed), 3560 default_address_cost) 3561 3562/* Permit speculative instructions in delay slots during delayed-branch 3563 scheduling. */ 3564DEFHOOK 3565(no_speculation_in_delay_slots_p, 3566 "This predicate controls the use of the eager delay slot filler to disallow\n\ 3567speculatively executed instructions being placed in delay slots. Targets\n\ 3568such as certain MIPS architectures possess both branches with and without\n\ 3569delay slots. As the eager delay slot filler can decrease performance,\n\ 3570disabling it is beneficial when ordinary branches are available. Use of\n\ 3571delay slot branches filled using the basic filler is often still desirable\n\ 3572as the delay slot can hide a pipeline bubble.", bool, (void), 3573 hook_bool_void_false) 3574 3575/* Return where to allocate pseudo for a given hard register initial value. */ 3576DEFHOOK 3577(allocate_initial_value, 3578 "\n\ 3579When the initial value of a hard register has been copied in a pseudo\n\ 3580register, it is often not necessary to actually allocate another register\n\ 3581to this pseudo register, because the original hard register or a stack slot\n\ 3582it has been saved into can be used. @code{TARGET_ALLOCATE_INITIAL_VALUE}\n\ 3583is called at the start of register allocation once for each hard register\n\ 3584that had its initial value copied by using\n\ 3585@code{get_func_hard_reg_initial_val} or @code{get_hard_reg_initial_val}.\n\ 3586Possible values are @code{NULL_RTX}, if you don't want\n\ 3587to do any special allocation, a @code{REG} rtx---that would typically be\n\ 3588the hard register itself, if it is known not to be clobbered---or a\n\ 3589@code{MEM}.\n\ 3590If you are returning a @code{MEM}, this is only a hint for the allocator;\n\ 3591it might decide to use another register anyways.\n\ 3592You may use @code{current_function_is_leaf} or \n\ 3593@code{REG_N_SETS} in the hook to determine if the hard\n\ 3594register in question will not be clobbered.\n\ 3595The default value of this hook is @code{NULL}, which disables any special\n\ 3596allocation.", 3597 rtx, (rtx hard_reg), NULL) 3598 3599/* Return nonzero if evaluating UNSPEC X might cause a trap. 3600 FLAGS has the same meaning as in rtlanal.c: may_trap_p_1. */ 3601DEFHOOK 3602(unspec_may_trap_p, 3603 "This target hook returns nonzero if @var{x}, an @code{unspec} or\n\ 3604@code{unspec_volatile} operation, might cause a trap. Targets can use\n\ 3605this hook to enhance precision of analysis for @code{unspec} and\n\ 3606@code{unspec_volatile} operations. You may call @code{may_trap_p_1}\n\ 3607to analyze inner elements of @var{x} in which case @var{flags} should be\n\ 3608passed along.", 3609 int, (const_rtx x, unsigned flags), 3610 default_unspec_may_trap_p) 3611 3612/* Given a register, this hook should return a parallel of registers 3613 to represent where to find the register pieces. Define this hook 3614 if the register and its mode are represented in Dwarf in 3615 non-contiguous locations, or if the register should be 3616 represented in more than one register in Dwarf. Otherwise, this 3617 hook should return NULL_RTX. */ 3618DEFHOOK 3619(dwarf_register_span, 3620 "Given a register, this hook should return a parallel of registers to\n\ 3621represent where to find the register pieces. Define this hook if the\n\ 3622register and its mode are represented in Dwarf in non-contiguous\n\ 3623locations, or if the register should be represented in more than one\n\ 3624register in Dwarf. Otherwise, this hook should return @code{NULL_RTX}.\n\ 3625If not defined, the default is to return @code{NULL_RTX}.", 3626 rtx, (rtx reg), 3627 hook_rtx_rtx_null) 3628 3629/* Given a register return the mode of the corresponding DWARF frame 3630 register. */ 3631DEFHOOK 3632(dwarf_frame_reg_mode, 3633 "Given a register, this hook should return the mode which the\n\ 3634corresponding Dwarf frame register should have. This is normally\n\ 3635used to return a smaller mode than the raw mode to prevent call\n\ 3636clobbered parts of a register altering the frame register size", 3637 machine_mode, (int regno), 3638 default_dwarf_frame_reg_mode) 3639 3640/* If expand_builtin_init_dwarf_reg_sizes needs to fill in table 3641 entries not corresponding directly to registers below 3642 FIRST_PSEUDO_REGISTER, this hook should generate the necessary 3643 code, given the address of the table. */ 3644DEFHOOK 3645(init_dwarf_reg_sizes_extra, 3646 "If some registers are represented in Dwarf-2 unwind information in\n\ 3647multiple pieces, define this hook to fill in information about the\n\ 3648sizes of those pieces in the table used by the unwinder at runtime.\n\ 3649It will be called by @code{expand_builtin_init_dwarf_reg_sizes} after\n\ 3650filling in a single size corresponding to each hard register;\n\ 3651@var{address} is the address of the table.", 3652 void, (tree address), 3653 hook_void_tree) 3654 3655/* Fetch the fixed register(s) which hold condition codes, for 3656 targets where it makes sense to look for duplicate assignments to 3657 the condition codes. This should return true if there is such a 3658 register, false otherwise. The arguments should be set to the 3659 fixed register numbers. Up to two condition code registers are 3660 supported. If there is only one for this target, the int pointed 3661 at by the second argument should be set to -1. */ 3662DEFHOOK 3663(fixed_condition_code_regs, 3664 "On targets which do not use @code{(cc0)}, and which use a hard\n\ 3665register rather than a pseudo-register to hold condition codes, the\n\ 3666regular CSE passes are often not able to identify cases in which the\n\ 3667hard register is set to a common value. Use this hook to enable a\n\ 3668small pass which optimizes such cases. This hook should return true\n\ 3669to enable this pass, and it should set the integers to which its\n\ 3670arguments point to the hard register numbers used for condition codes.\n\ 3671When there is only one such register, as is true on most systems, the\n\ 3672integer pointed to by @var{p2} should be set to\n\ 3673@code{INVALID_REGNUM}.\n\ 3674\n\ 3675The default version of this hook returns false.", 3676 bool, (unsigned int *p1, unsigned int *p2), 3677 hook_bool_uintp_uintp_false) 3678 3679/* If two condition code modes are compatible, return a condition 3680 code mode which is compatible with both, such that a comparison 3681 done in the returned mode will work for both of the original 3682 modes. If the condition code modes are not compatible, return 3683 VOIDmode. */ 3684DEFHOOK 3685(cc_modes_compatible, 3686 "On targets which use multiple condition code modes in class\n\ 3687@code{MODE_CC}, it is sometimes the case that a comparison can be\n\ 3688validly done in more than one mode. On such a system, define this\n\ 3689target hook to take two mode arguments and to return a mode in which\n\ 3690both comparisons may be validly done. If there is no such mode,\n\ 3691return @code{VOIDmode}.\n\ 3692\n\ 3693The default version of this hook checks whether the modes are the\n\ 3694same. If they are, it returns that mode. If they are different, it\n\ 3695returns @code{VOIDmode}.", 3696 machine_mode, (machine_mode m1, machine_mode m2), 3697 default_cc_modes_compatible) 3698 3699/* Do machine-dependent code transformations. Called just before 3700 delayed-branch scheduling. */ 3701DEFHOOK 3702(machine_dependent_reorg, 3703 "If non-null, this hook performs a target-specific pass over the\n\ 3704instruction stream. The compiler will run it at all optimization levels,\n\ 3705just before the point at which it normally does delayed-branch scheduling.\n\ 3706\n\ 3707The exact purpose of the hook varies from target to target. Some use\n\ 3708it to do transformations that are necessary for correctness, such as\n\ 3709laying out in-function constant pools or avoiding hardware hazards.\n\ 3710Others use it as an opportunity to do some machine-dependent optimizations.\n\ 3711\n\ 3712You need not implement the hook if it has nothing to do. The default\n\ 3713definition is null.", 3714 void, (void), NULL) 3715 3716/* Create the __builtin_va_list type. */ 3717DEFHOOK 3718(build_builtin_va_list, 3719 "This hook returns a type node for @code{va_list} for the target.\n\ 3720The default version of the hook returns @code{void*}.", 3721 tree, (void), 3722 std_build_builtin_va_list) 3723 3724/* Enumerate the va list variants. */ 3725DEFHOOK 3726(enum_va_list_p, 3727 "This target hook is used in function @code{c_common_nodes_and_builtins}\n\ 3728to iterate through the target specific builtin types for va_list. The\n\ 3729variable @var{idx} is used as iterator. @var{pname} has to be a pointer\n\ 3730to a @code{const char *} and @var{ptree} a pointer to a @code{tree} typed\n\ 3731variable.\n\ 3732The arguments @var{pname} and @var{ptree} are used to store the result of\n\ 3733this macro and are set to the name of the va_list builtin type and its\n\ 3734internal type.\n\ 3735If the return value of this macro is zero, then there is no more element.\n\ 3736Otherwise the @var{IDX} should be increased for the next call of this\n\ 3737macro to iterate through all types.", 3738 int, (int idx, const char **pname, tree *ptree), 3739 NULL) 3740 3741/* Get the cfun/fndecl calling abi __builtin_va_list type. */ 3742DEFHOOK 3743(fn_abi_va_list, 3744 "This hook returns the va_list type of the calling convention specified by\n\ 3745@var{fndecl}.\n\ 3746The default version of this hook returns @code{va_list_type_node}.", 3747 tree, (tree fndecl), 3748 std_fn_abi_va_list) 3749 3750/* Get the __builtin_va_list type dependent on input type. */ 3751DEFHOOK 3752(canonical_va_list_type, 3753 "This hook returns the va_list type of the calling convention specified by the\n\ 3754type of @var{type}. If @var{type} is not a valid va_list type, it returns\n\ 3755@code{NULL_TREE}.", 3756 tree, (tree type), 3757 std_canonical_va_list_type) 3758 3759/* ??? Documenting this hook requires a GFDL license grant. */ 3760DEFHOOK_UNDOC 3761(expand_builtin_va_start, 3762"Expand the @code{__builtin_va_start} builtin.", 3763 void, (tree valist, rtx nextarg), NULL) 3764 3765/* Gimplifies a VA_ARG_EXPR. */ 3766DEFHOOK 3767(gimplify_va_arg_expr, 3768 "This hook performs target-specific gimplification of\n\ 3769@code{VA_ARG_EXPR}. The first two parameters correspond to the\n\ 3770arguments to @code{va_arg}; the latter two are as in\n\ 3771@code{gimplify.c:gimplify_expr}.", 3772 tree, (tree valist, tree type, gimple_seq *pre_p, gimple_seq *post_p), 3773 std_gimplify_va_arg_expr) 3774 3775/* Validity-checking routines for PCH files, target-specific. 3776 get_pch_validity returns a pointer to the data to be stored, 3777 and stores the size in its argument. pch_valid_p gets the same 3778 information back and returns NULL if the PCH is valid, 3779 or an error message if not. */ 3780DEFHOOK 3781(get_pch_validity, 3782 "This hook returns a pointer to the data needed by\n\ 3783@code{TARGET_PCH_VALID_P} and sets\n\ 3784@samp{*@var{sz}} to the size of the data in bytes.", 3785 void *, (size_t *sz), 3786 default_get_pch_validity) 3787 3788DEFHOOK 3789(pch_valid_p, 3790 "This hook checks whether the options used to create a PCH file are\n\ 3791compatible with the current settings. It returns @code{NULL}\n\ 3792if so and a suitable error message if not. Error messages will\n\ 3793be presented to the user and must be localized using @samp{_(@var{msg})}.\n\ 3794\n\ 3795@var{data} is the data that was returned by @code{TARGET_GET_PCH_VALIDITY}\n\ 3796when the PCH file was created and @var{sz} is the size of that data in bytes.\n\ 3797It's safe to assume that the data was created by the same version of the\n\ 3798compiler, so no format checking is needed.\n\ 3799\n\ 3800The default definition of @code{default_pch_valid_p} should be\n\ 3801suitable for most targets.", 3802 const char *, (const void *data, size_t sz), 3803 default_pch_valid_p) 3804 3805DEFHOOK 3806(prepare_pch_save, 3807 "Called before writing out a PCH file. If the target has some\n\ 3808garbage-collected data that needs to be in a particular state on PCH loads,\n\ 3809it can use this hook to enforce that state. Very few targets need\n\ 3810to do anything here.", 3811 void, (void), 3812 hook_void_void) 3813 3814/* If nonnull, this function checks whether a PCH file with the 3815 given set of target flags can be used. It returns NULL if so, 3816 otherwise it returns an error message. */ 3817DEFHOOK 3818(check_pch_target_flags, 3819 "If this hook is nonnull, the default implementation of\n\ 3820@code{TARGET_PCH_VALID_P} will use it to check for compatible values\n\ 3821of @code{target_flags}. @var{pch_flags} specifies the value that\n\ 3822@code{target_flags} had when the PCH file was created. The return\n\ 3823value is the same as for @code{TARGET_PCH_VALID_P}.", 3824 const char *, (int pch_flags), NULL) 3825 3826/* True if the compiler should give an enum type only as many 3827 bytes as it takes to represent the range of possible values of 3828 that type. */ 3829DEFHOOK 3830(default_short_enums, 3831 "This target hook should return true if the compiler should give an\n\ 3832@code{enum} type only as many bytes as it takes to represent the range\n\ 3833of possible values of that type. It should return false if all\n\ 3834@code{enum} types should be allocated like @code{int}.\n\ 3835\n\ 3836The default is to return false.", 3837 bool, (void), 3838 hook_bool_void_false) 3839 3840/* This target hook returns an rtx that is used to store the address 3841 of the current frame into the built-in setjmp buffer. */ 3842DEFHOOK 3843(builtin_setjmp_frame_value, 3844 "This target hook should return an rtx that is used to store\n\ 3845the address of the current frame into the built in @code{setjmp} buffer.\n\ 3846The default value, @code{virtual_stack_vars_rtx}, is correct for most\n\ 3847machines. One reason you may need to define this target hook is if\n\ 3848@code{hard_frame_pointer_rtx} is the appropriate value on your machine.", 3849 rtx, (void), 3850 default_builtin_setjmp_frame_value) 3851 3852/* This target hook should manipulate the outputs, inputs, constraints, 3853 and clobbers the port wishes for pre-processing the asm. */ 3854DEFHOOK 3855(md_asm_adjust, 3856 "This target hook may add @dfn{clobbers} to @var{clobbers} and\n\ 3857@var{clobbered_regs} for any hard regs the port wishes to automatically\n\ 3858clobber for an asm. The @var{outputs} and @var{inputs} may be inspected\n\ 3859to avoid clobbering a register that is already used by the asm.\n\ 3860\n\ 3861It may modify the @var{outputs}, @var{inputs}, and @var{constraints}\n\ 3862as necessary for other pre-processing. In this case the return value is\n\ 3863a sequence of insns to emit after the asm.", 3864 rtx_insn *, 3865 (vec<rtx>& outputs, vec<rtx>& inputs, vec<const char *>& constraints, 3866 vec<rtx>& clobbers, HARD_REG_SET& clobbered_regs), 3867 NULL) 3868 3869/* This target hook allows the backend to specify a calling convention 3870 in the debug information. This function actually returns an 3871 enum dwarf_calling_convention, but because of forward declarations 3872 and not wanting to include dwarf2.h everywhere target.h is included 3873 the function is being declared as an int. */ 3874DEFHOOK 3875(dwarf_calling_convention, 3876 "Define this to enable the dwarf attribute @code{DW_AT_calling_convention} to\n\ 3877be emitted for each function. Instead of an integer return the enum\n\ 3878value for the @code{DW_CC_} tag.", 3879 int, (const_tree function), 3880 hook_int_const_tree_0) 3881 3882/* This target hook allows the backend to emit frame-related insns that 3883 contain UNSPECs or UNSPEC_VOLATILEs. The call frame debugging info 3884 engine will invoke it on insns of the form 3885 (set (reg) (unspec [...] UNSPEC_INDEX)) 3886 and 3887 (set (reg) (unspec_volatile [...] UNSPECV_INDEX)) 3888 to let the backend emit the call frame instructions. */ 3889DEFHOOK 3890(dwarf_handle_frame_unspec, 3891 "This target hook allows the backend to emit frame-related insns that\n\ 3892contain UNSPECs or UNSPEC_VOLATILEs. The DWARF 2 call frame debugging\n\ 3893info engine will invoke it on insns of the form\n\ 3894@smallexample\n\ 3895(set (reg) (unspec [@dots{}] UNSPEC_INDEX))\n\ 3896@end smallexample\n\ 3897and\n\ 3898@smallexample\n\ 3899(set (reg) (unspec_volatile [@dots{}] UNSPECV_INDEX)).\n\ 3900@end smallexample\n\ 3901to let the backend emit the call frame instructions. @var{label} is\n\ 3902the CFI label attached to the insn, @var{pattern} is the pattern of\n\ 3903the insn and @var{index} is @code{UNSPEC_INDEX} or @code{UNSPECV_INDEX}.", 3904 void, (const char *label, rtx pattern, int index), NULL) 3905 3906/* ??? Documenting this hook requires a GFDL license grant. */ 3907DEFHOOK_UNDOC 3908(stdarg_optimize_hook, 3909"Perform architecture specific checking of statements gimplified\ 3910 from @code{VA_ARG_EXPR}. @var{stmt} is the statement. Returns true if\ 3911 the statement doesn't need to be checked for @code{va_list} references.", 3912 bool, (struct stdarg_info *ai, const gimple *stmt), NULL) 3913 3914/* This target hook allows the operating system to override the DECL 3915 that represents the external variable that contains the stack 3916 protection guard variable. The type of this DECL is ptr_type_node. */ 3917DEFHOOK 3918(stack_protect_guard, 3919 "This hook returns a @code{DECL} node for the external variable to use\n\ 3920for the stack protection guard. This variable is initialized by the\n\ 3921runtime to some random value and is used to initialize the guard value\n\ 3922that is placed at the top of the local stack frame. The type of this\n\ 3923variable must be @code{ptr_type_node}.\n\ 3924\n\ 3925The default version of this hook creates a variable called\n\ 3926@samp{__stack_chk_guard}, which is normally defined in @file{libgcc2.c}.", 3927 tree, (void), 3928 default_stack_protect_guard) 3929 3930/* This target hook allows the operating system to override the CALL_EXPR 3931 that is invoked when a check vs the guard variable fails. */ 3932DEFHOOK 3933(stack_protect_fail, 3934 "This hook returns a @code{CALL_EXPR} that alerts the runtime that the\n\ 3935stack protect guard variable has been modified. This expression should\n\ 3936involve a call to a @code{noreturn} function.\n\ 3937\n\ 3938The default version of this hook invokes a function called\n\ 3939@samp{__stack_chk_fail}, taking no arguments. This function is\n\ 3940normally defined in @file{libgcc2.c}.", 3941 tree, (void), 3942 default_external_stack_protect_fail) 3943 3944DEFHOOK 3945(can_use_doloop_p, 3946 "Return true if it is possible to use low-overhead loops (@code{doloop_end}\n\ 3947and @code{doloop_begin}) for a particular loop. @var{iterations} gives the\n\ 3948exact number of iterations, or 0 if not known. @var{iterations_max} gives\n\ 3949the maximum number of iterations, or 0 if not known. @var{loop_depth} is\n\ 3950the nesting depth of the loop, with 1 for innermost loops, 2 for loops that\n\ 3951contain innermost loops, and so on. @var{entered_at_top} is true if the\n\ 3952loop is only entered from the top.\n\ 3953\n\ 3954This hook is only used if @code{doloop_end} is available. The default\n\ 3955implementation returns true. You can use @code{can_use_doloop_if_innermost}\n\ 3956if the loop must be the innermost, and if there are no other restrictions.", 3957 bool, (const widest_int &iterations, const widest_int &iterations_max, 3958 unsigned int loop_depth, bool entered_at_top), 3959 hook_bool_wint_wint_uint_bool_true) 3960 3961/* Returns NULL if target supports the insn within a doloop block, 3962 otherwise it returns an error message. */ 3963DEFHOOK 3964(invalid_within_doloop, 3965 "\n\ 3966Take an instruction in @var{insn} and return NULL if it is valid within a\n\ 3967low-overhead loop, otherwise return a string explaining why doloop\n\ 3968could not be applied.\n\ 3969\n\ 3970Many targets use special registers for low-overhead looping. For any\n\ 3971instruction that clobbers these this function should return a string indicating\n\ 3972the reason why the doloop could not be applied.\n\ 3973By default, the RTL loop optimizer does not use a present doloop pattern for\n\ 3974loops containing function calls or branch on table instructions.", 3975 const char *, (const rtx_insn *insn), 3976 default_invalid_within_doloop) 3977 3978/* Returns true for a legitimate combined insn. */ 3979DEFHOOK 3980(legitimate_combined_insn, 3981"Take an instruction in @var{insn} and return @code{false} if the instruction\ 3982 is not appropriate as a combination of two or more instructions. The\ 3983 default is to accept all instructions.", 3984 bool, (rtx_insn *insn), 3985 hook_bool_rtx_insn_true) 3986 3987DEFHOOK 3988(valid_dllimport_attribute_p, 3989"@var{decl} is a variable or function with @code{__attribute__((dllimport))}\ 3990 specified. Use this hook if the target needs to add extra validation\ 3991 checks to @code{handle_dll_attribute}.", 3992 bool, (const_tree decl), 3993 hook_bool_const_tree_true) 3994 3995/* If non-zero, align constant anchors in CSE to a multiple of this 3996 value. */ 3997DEFHOOKPOD 3998(const_anchor, 3999 "On some architectures it can take multiple instructions to synthesize\n\ 4000a constant. If there is another constant already in a register that\n\ 4001is close enough in value then it is preferable that the new constant\n\ 4002is computed from this register using immediate addition or\n\ 4003subtraction. We accomplish this through CSE. Besides the value of\n\ 4004the constant we also add a lower and an upper constant anchor to the\n\ 4005available expressions. These are then queried when encountering new\n\ 4006constants. The anchors are computed by rounding the constant up and\n\ 4007down to a multiple of the value of @code{TARGET_CONST_ANCHOR}.\n\ 4008@code{TARGET_CONST_ANCHOR} should be the maximum positive value\n\ 4009accepted by immediate-add plus one. We currently assume that the\n\ 4010value of @code{TARGET_CONST_ANCHOR} is a power of 2. For example, on\n\ 4011MIPS, where add-immediate takes a 16-bit signed value,\n\ 4012@code{TARGET_CONST_ANCHOR} is set to @samp{0x8000}. The default value\n\ 4013is zero, which disables this optimization.", 4014 unsigned HOST_WIDE_INT, 0) 4015 4016/* Defines, which target-dependent bits (upper 16) are used by port */ 4017DEFHOOK 4018(memmodel_check, 4019 "Validate target specific memory model mask bits. When NULL no target specific\n\ 4020memory model bits are allowed.", 4021 unsigned HOST_WIDE_INT, (unsigned HOST_WIDE_INT val), NULL) 4022 4023/* Defines an offset bitwise ored into shifted address to get corresponding 4024 Address Sanitizer shadow address, or -1 if Address Sanitizer is not 4025 supported by the target. */ 4026DEFHOOK 4027(asan_shadow_offset, 4028 "Return the offset bitwise ored into shifted address to get corresponding\n\ 4029Address Sanitizer shadow memory address. NULL if Address Sanitizer is not\n\ 4030supported by the target.", 4031 unsigned HOST_WIDE_INT, (void), 4032 NULL) 4033 4034/* Functions relating to calls - argument passing, returns, etc. */ 4035/* Members of struct call have no special macro prefix. */ 4036HOOK_VECTOR (TARGET_CALLS, calls) 4037 4038DEFHOOK 4039(promote_function_mode, 4040 "Like @code{PROMOTE_MODE}, but it is applied to outgoing function arguments or\n\ 4041function return values. The target hook should return the new mode\n\ 4042and possibly change @code{*@var{punsignedp}} if the promotion should\n\ 4043change signedness. This function is called only for scalar @emph{or\n\ 4044pointer} types.\n\ 4045\n\ 4046@var{for_return} allows to distinguish the promotion of arguments and\n\ 4047return values. If it is @code{1}, a return value is being promoted and\n\ 4048@code{TARGET_FUNCTION_VALUE} must perform the same promotions done here.\n\ 4049If it is @code{2}, the returned mode should be that of the register in\n\ 4050which an incoming parameter is copied, or the outgoing result is computed;\n\ 4051then the hook should return the same mode as @code{promote_mode}, though\n\ 4052the signedness may be different.\n\ 4053\n\ 4054@var{type} can be NULL when promoting function arguments of libcalls.\n\ 4055\n\ 4056The default is to not promote arguments and return values. You can\n\ 4057also define the hook to @code{default_promote_function_mode_always_promote}\n\ 4058if you would like to apply the same rules given by @code{PROMOTE_MODE}.", 4059 machine_mode, (const_tree type, machine_mode mode, int *punsignedp, 4060 const_tree funtype, int for_return), 4061 default_promote_function_mode) 4062 4063DEFHOOK 4064(promote_prototypes, 4065 "This target hook returns @code{true} if an argument declared in a\n\ 4066prototype as an integral type smaller than @code{int} should actually be\n\ 4067passed as an @code{int}. In addition to avoiding errors in certain\n\ 4068cases of mismatch, it also makes for better code on certain machines.\n\ 4069The default is to not promote prototypes.", 4070 bool, (const_tree fntype), 4071 hook_bool_const_tree_false) 4072 4073DEFHOOK 4074(struct_value_rtx, 4075 "This target hook should return the location of the structure value\n\ 4076address (normally a @code{mem} or @code{reg}), or 0 if the address is\n\ 4077passed as an ``invisible'' first argument. Note that @var{fndecl} may\n\ 4078be @code{NULL}, for libcalls. You do not need to define this target\n\ 4079hook if the address is always passed as an ``invisible'' first\n\ 4080argument.\n\ 4081\n\ 4082On some architectures the place where the structure value address\n\ 4083is found by the called function is not the same place that the\n\ 4084caller put it. This can be due to register windows, or it could\n\ 4085be because the function prologue moves it to a different place.\n\ 4086@var{incoming} is @code{1} or @code{2} when the location is needed in\n\ 4087the context of the called function, and @code{0} in the context of\n\ 4088the caller.\n\ 4089\n\ 4090If @var{incoming} is nonzero and the address is to be found on the\n\ 4091stack, return a @code{mem} which refers to the frame pointer. If\n\ 4092@var{incoming} is @code{2}, the result is being used to fetch the\n\ 4093structure value address at the beginning of a function. If you need\n\ 4094to emit adjusting code, you should do it at this point.", 4095 rtx, (tree fndecl, int incoming), 4096 hook_rtx_tree_int_null) 4097 4098DEFHOOKPOD 4099(omit_struct_return_reg, 4100 "Normally, when a function returns a structure by memory, the address\n\ 4101is passed as an invisible pointer argument, but the compiler also\n\ 4102arranges to return the address from the function like it would a normal\n\ 4103pointer return value. Define this to true if that behavior is\n\ 4104undesirable on your target.", 4105 bool, false) 4106 4107DEFHOOK 4108(return_in_memory, 4109 "This target hook should return a nonzero value to say to return the\n\ 4110function value in memory, just as large structures are always returned.\n\ 4111Here @var{type} will be the data type of the value, and @var{fntype}\n\ 4112will be the type of the function doing the returning, or @code{NULL} for\n\ 4113libcalls.\n\ 4114\n\ 4115Note that values of mode @code{BLKmode} must be explicitly handled\n\ 4116by this function. Also, the option @option{-fpcc-struct-return}\n\ 4117takes effect regardless of this macro. On most systems, it is\n\ 4118possible to leave the hook undefined; this causes a default\n\ 4119definition to be used, whose value is the constant 1 for @code{BLKmode}\n\ 4120values, and 0 otherwise.\n\ 4121\n\ 4122Do not use this hook to indicate that structures and unions should always\n\ 4123be returned in memory. You should instead use @code{DEFAULT_PCC_STRUCT_RETURN}\n\ 4124to indicate this.", 4125 bool, (const_tree type, const_tree fntype), 4126 default_return_in_memory) 4127 4128DEFHOOK 4129(return_in_msb, 4130 "This hook should return true if values of type @var{type} are returned\n\ 4131at the most significant end of a register (in other words, if they are\n\ 4132padded at the least significant end). You can assume that @var{type}\n\ 4133is returned in a register; the caller is required to check this.\n\ 4134\n\ 4135Note that the register provided by @code{TARGET_FUNCTION_VALUE} must\n\ 4136be able to hold the complete return value. For example, if a 1-, 2-\n\ 4137or 3-byte structure is returned at the most significant end of a\n\ 41384-byte register, @code{TARGET_FUNCTION_VALUE} should provide an\n\ 4139@code{SImode} rtx.", 4140 bool, (const_tree type), 4141 hook_bool_const_tree_false) 4142 4143/* Return true if a parameter must be passed by reference. TYPE may 4144 be null if this is a libcall. CA may be null if this query is 4145 from __builtin_va_arg. */ 4146DEFHOOK 4147(pass_by_reference, 4148 "This target hook should return @code{true} if an argument at the\n\ 4149position indicated by @var{cum} should be passed by reference. This\n\ 4150predicate is queried after target independent reasons for being\n\ 4151passed by reference, such as @code{TREE_ADDRESSABLE (type)}.\n\ 4152\n\ 4153If the hook returns true, a copy of that argument is made in memory and a\n\ 4154pointer to the argument is passed instead of the argument itself.\n\ 4155The pointer is passed in whatever way is appropriate for passing a pointer\n\ 4156to that type.", 4157 bool, 4158 (cumulative_args_t cum, machine_mode mode, const_tree type, bool named), 4159 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false) 4160 4161DEFHOOK 4162(expand_builtin_saveregs, 4163 "If defined, this hook produces the machine-specific code for a call to\n\ 4164@code{__builtin_saveregs}. This code will be moved to the very\n\ 4165beginning of the function, before any parameter access are made. The\n\ 4166return value of this function should be an RTX that contains the value\n\ 4167to use as the return of @code{__builtin_saveregs}.", 4168 rtx, (void), 4169 default_expand_builtin_saveregs) 4170 4171/* Returns pretend_argument_size. */ 4172DEFHOOK 4173(setup_incoming_varargs, 4174 "This target hook offers an alternative to using\n\ 4175@code{__builtin_saveregs} and defining the hook\n\ 4176@code{TARGET_EXPAND_BUILTIN_SAVEREGS}. Use it to store the anonymous\n\ 4177register arguments into the stack so that all the arguments appear to\n\ 4178have been passed consecutively on the stack. Once this is done, you can\n\ 4179use the standard implementation of varargs that works for machines that\n\ 4180pass all their arguments on the stack.\n\ 4181\n\ 4182The argument @var{args_so_far} points to the @code{CUMULATIVE_ARGS} data\n\ 4183structure, containing the values that are obtained after processing the\n\ 4184named arguments. The arguments @var{mode} and @var{type} describe the\n\ 4185last named argument---its machine mode and its data type as a tree node.\n\ 4186\n\ 4187The target hook should do two things: first, push onto the stack all the\n\ 4188argument registers @emph{not} used for the named arguments, and second,\n\ 4189store the size of the data thus pushed into the @code{int}-valued\n\ 4190variable pointed to by @var{pretend_args_size}. The value that you\n\ 4191store here will serve as additional offset for setting up the stack\n\ 4192frame.\n\ 4193\n\ 4194Because you must generate code to push the anonymous arguments at\n\ 4195compile time without knowing their data types,\n\ 4196@code{TARGET_SETUP_INCOMING_VARARGS} is only useful on machines that\n\ 4197have just a single category of argument register and use it uniformly\n\ 4198for all data types.\n\ 4199\n\ 4200If the argument @var{second_time} is nonzero, it means that the\n\ 4201arguments of the function are being analyzed for the second time. This\n\ 4202happens for an inline function, which is not actually compiled until the\n\ 4203end of the source file. The hook @code{TARGET_SETUP_INCOMING_VARARGS} should\n\ 4204not generate any instructions in this case.", 4205 void, (cumulative_args_t args_so_far, machine_mode mode, tree type, 4206 int *pretend_args_size, int second_time), 4207 default_setup_incoming_varargs) 4208 4209DEFHOOK 4210(load_bounds_for_arg, 4211 "This hook is used by expand pass to emit insn to load bounds of\n\ 4212@var{arg} passed in @var{slot}. Expand pass uses this hook in case\n\ 4213bounds of @var{arg} are not passed in register. If @var{slot} is a\n\ 4214memory, then bounds are loaded as for regular pointer loaded from\n\ 4215memory. If @var{slot} is not a memory then @var{slot_no} is an integer\n\ 4216constant holding number of the target dependent special slot which\n\ 4217should be used to obtain bounds. Hook returns RTX holding loaded bounds.", 4218 rtx, (rtx slot, rtx arg, rtx slot_no), 4219 default_load_bounds_for_arg) 4220 4221DEFHOOK 4222(store_bounds_for_arg, 4223 "This hook is used by expand pass to emit insns to store @var{bounds} of\n\ 4224@var{arg} passed in @var{slot}. Expand pass uses this hook in case\n\ 4225@var{bounds} of @var{arg} are not passed in register. If @var{slot} is a\n\ 4226memory, then @var{bounds} are stored as for regular pointer stored in\n\ 4227memory. If @var{slot} is not a memory then @var{slot_no} is an integer\n\ 4228constant holding number of the target dependent special slot which\n\ 4229should be used to store @var{bounds}.", 4230 void, (rtx arg, rtx slot, rtx bounds, rtx slot_no), 4231 default_store_bounds_for_arg) 4232 4233DEFHOOK 4234(load_returned_bounds, 4235 "This hook is used by expand pass to emit insn to load bounds\n\ 4236returned by function call in @var{slot}. Hook returns RTX holding\n\ 4237loaded bounds.", 4238 rtx, (rtx slot), 4239 default_load_returned_bounds) 4240 4241DEFHOOK 4242(store_returned_bounds, 4243 "This hook is used by expand pass to emit insn to store @var{bounds}\n\ 4244returned by function call into @var{slot}.", 4245 void, (rtx slot, rtx bounds), 4246 default_store_returned_bounds) 4247 4248DEFHOOK 4249(setup_incoming_vararg_bounds, 4250 "Use it to store bounds for anonymous register arguments stored\n\ 4251into the stack. Arguments meaning is similar to\n\ 4252@code{TARGET_SETUP_INCOMING_VARARGS}.", 4253 void, (cumulative_args_t args_so_far, enum machine_mode mode, tree type, 4254 int *pretend_args_size, int second_time), 4255 default_setup_incoming_vararg_bounds) 4256 4257DEFHOOK 4258(call_args, 4259 "While generating RTL for a function call, this target hook is invoked once\n\ 4260for each argument passed to the function, either a register returned by\n\ 4261@code{TARGET_FUNCTION_ARG} or a memory location. It is called just\n\ 4262before the point where argument registers are stored. The type of the\n\ 4263function to be called is also passed as the second argument; it is\n\ 4264@code{NULL_TREE} for libcalls. The @code{TARGET_END_CALL_ARGS} hook is\n\ 4265invoked just after the code to copy the return reg has been emitted.\n\ 4266This functionality can be used to perform special setup of call argument\n\ 4267registers if a target needs it.\n\ 4268For functions without arguments, the hook is called once with @code{pc_rtx}\n\ 4269passed instead of an argument register.\n\ 4270Most ports do not need to implement anything for this hook.", 4271 void, (rtx, tree), 4272 hook_void_rtx_tree) 4273 4274DEFHOOK 4275(end_call_args, 4276 "This target hook is invoked while generating RTL for a function call,\n\ 4277just after the point where the return reg is copied into a pseudo. It\n\ 4278signals that all the call argument and return registers for the just\n\ 4279emitted call are now no longer in use.\n\ 4280Most ports do not need to implement anything for this hook.", 4281 void, (void), 4282 hook_void_void) 4283 4284DEFHOOK 4285(strict_argument_naming, 4286 "Define this hook to return @code{true} if the location where a function\n\ 4287argument is passed depends on whether or not it is a named argument.\n\ 4288\n\ 4289This hook controls how the @var{named} argument to @code{TARGET_FUNCTION_ARG}\n\ 4290is set for varargs and stdarg functions. If this hook returns\n\ 4291@code{true}, the @var{named} argument is always true for named\n\ 4292arguments, and false for unnamed arguments. If it returns @code{false},\n\ 4293but @code{TARGET_PRETEND_OUTGOING_VARARGS_NAMED} returns @code{true},\n\ 4294then all arguments are treated as named. Otherwise, all named arguments\n\ 4295except the last are treated as named.\n\ 4296\n\ 4297You need not define this hook if it always returns @code{false}.", 4298 bool, (cumulative_args_t ca), 4299 hook_bool_CUMULATIVE_ARGS_false) 4300 4301/* Returns true if we should use 4302 targetm.calls.setup_incoming_varargs() and/or 4303 targetm.calls.strict_argument_naming(). */ 4304DEFHOOK 4305(pretend_outgoing_varargs_named, 4306 "If you need to conditionally change ABIs so that one works with\n\ 4307@code{TARGET_SETUP_INCOMING_VARARGS}, but the other works like neither\n\ 4308@code{TARGET_SETUP_INCOMING_VARARGS} nor @code{TARGET_STRICT_ARGUMENT_NAMING} was\n\ 4309defined, then define this hook to return @code{true} if\n\ 4310@code{TARGET_SETUP_INCOMING_VARARGS} is used, @code{false} otherwise.\n\ 4311Otherwise, you should not define this hook.", 4312 bool, (cumulative_args_t ca), 4313 default_pretend_outgoing_varargs_named) 4314 4315/* Given a complex type T, return true if a parameter of type T 4316 should be passed as two scalars. */ 4317DEFHOOK 4318(split_complex_arg, 4319 "This hook should return true if parameter of type @var{type} are passed\n\ 4320as two scalar parameters. By default, GCC will attempt to pack complex\n\ 4321arguments into the target's word size. Some ABIs require complex arguments\n\ 4322to be split and treated as their individual components. For example, on\n\ 4323AIX64, complex floats should be passed in a pair of floating point\n\ 4324registers, even though a complex float would fit in one 64-bit floating\n\ 4325point register.\n\ 4326\n\ 4327The default value of this hook is @code{NULL}, which is treated as always\n\ 4328false.", 4329 bool, (const_tree type), NULL) 4330 4331/* Return true if type T, mode MODE, may not be passed in registers, 4332 but must be passed on the stack. */ 4333/* ??? This predicate should be applied strictly after pass-by-reference. 4334 Need audit to verify that this is the case. */ 4335DEFHOOK 4336(must_pass_in_stack, 4337 "This target hook should return @code{true} if we should not pass @var{type}\n\ 4338solely in registers. The file @file{expr.h} defines a\n\ 4339definition that is usually appropriate, refer to @file{expr.h} for additional\n\ 4340documentation.", 4341 bool, (machine_mode mode, const_tree type), 4342 must_pass_in_stack_var_size_or_pad) 4343 4344/* Return true if type TYPE, mode MODE, which is passed by reference, 4345 should have the object copy generated by the callee rather than 4346 the caller. It is never called for TYPE requiring constructors. */ 4347DEFHOOK 4348(callee_copies, 4349 "The function argument described by the parameters to this hook is\n\ 4350known to be passed by reference. The hook should return true if the\n\ 4351function argument should be copied by the callee instead of copied\n\ 4352by the caller.\n\ 4353\n\ 4354For any argument for which the hook returns true, if it can be\n\ 4355determined that the argument is not modified, then a copy need\n\ 4356not be generated.\n\ 4357\n\ 4358The default version of this hook always returns false.", 4359 bool, 4360 (cumulative_args_t cum, machine_mode mode, const_tree type, bool named), 4361 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false) 4362 4363/* Return zero for arguments passed entirely on the stack or entirely 4364 in registers. If passed in both, return the number of bytes passed 4365 in registers; the balance is therefore passed on the stack. */ 4366DEFHOOK 4367(arg_partial_bytes, 4368 "This target hook returns the number of bytes at the beginning of an\n\ 4369argument that must be put in registers. The value must be zero for\n\ 4370arguments that are passed entirely in registers or that are entirely\n\ 4371pushed on the stack.\n\ 4372\n\ 4373On some machines, certain arguments must be passed partially in\n\ 4374registers and partially in memory. On these machines, typically the\n\ 4375first few words of arguments are passed in registers, and the rest\n\ 4376on the stack. If a multi-word argument (a @code{double} or a\n\ 4377structure) crosses that boundary, its first few words must be passed\n\ 4378in registers and the rest must be pushed. This macro tells the\n\ 4379compiler when this occurs, and how many bytes should go in registers.\n\ 4380\n\ 4381@code{TARGET_FUNCTION_ARG} for these arguments should return the first\n\ 4382register to be used by the caller for this argument; likewise\n\ 4383@code{TARGET_FUNCTION_INCOMING_ARG}, for the called function.", 4384 int, (cumulative_args_t cum, machine_mode mode, tree type, bool named), 4385 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0) 4386 4387/* Update the state in CA to advance past an argument in the 4388 argument list. The values MODE, TYPE, and NAMED describe that 4389 argument. */ 4390DEFHOOK 4391(function_arg_advance, 4392 "This hook updates the summarizer variable pointed to by @var{ca} to\n\ 4393advance past an argument in the argument list. The values @var{mode},\n\ 4394@var{type} and @var{named} describe that argument. Once this is done,\n\ 4395the variable @var{cum} is suitable for analyzing the @emph{following}\n\ 4396argument with @code{TARGET_FUNCTION_ARG}, etc.\n\ 4397\n\ 4398This hook need not do anything if the argument in question was passed\n\ 4399on the stack. The compiler knows how to track the amount of stack space\n\ 4400used for arguments without any special help.", 4401 void, 4402 (cumulative_args_t ca, machine_mode mode, const_tree type, bool named), 4403 default_function_arg_advance) 4404 4405/* Return zero if the argument described by the state of CA should 4406 be placed on a stack, or a hard register in which to store the 4407 argument. The values MODE, TYPE, and NAMED describe that 4408 argument. */ 4409DEFHOOK 4410(function_arg, 4411 "Return an RTX indicating whether a function argument is passed in a\n\ 4412register and if so, which register.\n\ 4413\n\ 4414The arguments are @var{ca}, which summarizes all the previous\n\ 4415arguments; @var{mode}, the machine mode of the argument; @var{type},\n\ 4416the data type of the argument as a tree node or 0 if that is not known\n\ 4417(which happens for C support library functions); and @var{named},\n\ 4418which is @code{true} for an ordinary argument and @code{false} for\n\ 4419nameless arguments that correspond to @samp{@dots{}} in the called\n\ 4420function's prototype. @var{type} can be an incomplete type if a\n\ 4421syntax error has previously occurred.\n\ 4422\n\ 4423The return value is usually either a @code{reg} RTX for the hard\n\ 4424register in which to pass the argument, or zero to pass the argument\n\ 4425on the stack.\n\ 4426\n\ 4427The return value can be a @code{const_int} which means argument is\n\ 4428passed in a target specific slot with specified number. Target hooks\n\ 4429should be used to store or load argument in such case. See\n\ 4430@code{TARGET_STORE_BOUNDS_FOR_ARG} and @code{TARGET_LOAD_BOUNDS_FOR_ARG}\n\ 4431for more information.\n\ 4432\n\ 4433The value of the expression can also be a @code{parallel} RTX@. This is\n\ 4434used when an argument is passed in multiple locations. The mode of the\n\ 4435@code{parallel} should be the mode of the entire argument. The\n\ 4436@code{parallel} holds any number of @code{expr_list} pairs; each one\n\ 4437describes where part of the argument is passed. In each\n\ 4438@code{expr_list} the first operand must be a @code{reg} RTX for the hard\n\ 4439register in which to pass this part of the argument, and the mode of the\n\ 4440register RTX indicates how large this part of the argument is. The\n\ 4441second operand of the @code{expr_list} is a @code{const_int} which gives\n\ 4442the offset in bytes into the entire argument of where this part starts.\n\ 4443As a special exception the first @code{expr_list} in the @code{parallel}\n\ 4444RTX may have a first operand of zero. This indicates that the entire\n\ 4445argument is also stored on the stack.\n\ 4446\n\ 4447The last time this hook is called, it is called with @code{MODE ==\n\ 4448VOIDmode}, and its result is passed to the @code{call} or @code{call_value}\n\ 4449pattern as operands 2 and 3 respectively.\n\ 4450\n\ 4451@cindex @file{stdarg.h} and register arguments\n\ 4452The usual way to make the ISO library @file{stdarg.h} work on a\n\ 4453machine where some arguments are usually passed in registers, is to\n\ 4454cause nameless arguments to be passed on the stack instead. This is\n\ 4455done by making @code{TARGET_FUNCTION_ARG} return 0 whenever\n\ 4456@var{named} is @code{false}.\n\ 4457\n\ 4458@cindex @code{TARGET_MUST_PASS_IN_STACK}, and @code{TARGET_FUNCTION_ARG}\n\ 4459@cindex @code{REG_PARM_STACK_SPACE}, and @code{TARGET_FUNCTION_ARG}\n\ 4460You may use the hook @code{targetm.calls.must_pass_in_stack}\n\ 4461in the definition of this macro to determine if this argument is of a\n\ 4462type that must be passed in the stack. If @code{REG_PARM_STACK_SPACE}\n\ 4463is not defined and @code{TARGET_FUNCTION_ARG} returns nonzero for such an\n\ 4464argument, the compiler will abort. If @code{REG_PARM_STACK_SPACE} is\n\ 4465defined, the argument will be computed in the stack and then loaded into\n\ 4466a register.", 4467 rtx, (cumulative_args_t ca, machine_mode mode, const_tree type, 4468 bool named), 4469 default_function_arg) 4470 4471/* Likewise, but for machines with register windows. Return the 4472 location where the argument will appear to the callee. */ 4473DEFHOOK 4474(function_incoming_arg, 4475 "Define this hook if the target machine has ``register windows'', so\n\ 4476that the register in which a function sees an arguments is not\n\ 4477necessarily the same as the one in which the caller passed the\n\ 4478argument.\n\ 4479\n\ 4480For such machines, @code{TARGET_FUNCTION_ARG} computes the register in\n\ 4481which the caller passes the value, and\n\ 4482@code{TARGET_FUNCTION_INCOMING_ARG} should be defined in a similar\n\ 4483fashion to tell the function being called where the arguments will\n\ 4484arrive.\n\ 4485\n\ 4486If @code{TARGET_FUNCTION_INCOMING_ARG} is not defined,\n\ 4487@code{TARGET_FUNCTION_ARG} serves both purposes.", 4488 rtx, (cumulative_args_t ca, machine_mode mode, const_tree type, 4489 bool named), 4490 default_function_incoming_arg) 4491 4492DEFHOOK 4493(function_arg_boundary, 4494 "This hook returns the alignment boundary, in bits, of an argument\n\ 4495with the specified mode and type. The default hook returns\n\ 4496@code{PARM_BOUNDARY} for all arguments.", 4497 unsigned int, (machine_mode mode, const_tree type), 4498 default_function_arg_boundary) 4499 4500DEFHOOK 4501(function_arg_round_boundary, 4502 "Normally, the size of an argument is rounded up to @code{PARM_BOUNDARY},\n\ 4503which is the default value for this hook. You can define this hook to\n\ 4504return a different value if an argument size must be rounded to a larger\n\ 4505value.", 4506 unsigned int, (machine_mode mode, const_tree type), 4507 default_function_arg_round_boundary) 4508 4509/* Return the diagnostic message string if function without a prototype 4510 is not allowed for this 'val' argument; NULL otherwise. */ 4511DEFHOOK 4512(invalid_arg_for_unprototyped_fn, 4513 "If defined, this macro returns the diagnostic message when it is\n\ 4514illegal to pass argument @var{val} to function @var{funcdecl}\n\ 4515with prototype @var{typelist}.", 4516 const char *, (const_tree typelist, const_tree funcdecl, const_tree val), 4517 hook_invalid_arg_for_unprototyped_fn) 4518 4519/* Return an rtx for the return value location of the function 4520 specified by FN_DECL_OR_TYPE with a return type of RET_TYPE. */ 4521DEFHOOK 4522(function_value, 4523 "\n\ 4524Define this to return an RTX representing the place where a function\n\ 4525returns or receives a value of data type @var{ret_type}, a tree node\n\ 4526representing a data type. @var{fn_decl_or_type} is a tree node\n\ 4527representing @code{FUNCTION_DECL} or @code{FUNCTION_TYPE} of a\n\ 4528function being called. If @var{outgoing} is false, the hook should\n\ 4529compute the register in which the caller will see the return value.\n\ 4530Otherwise, the hook should return an RTX representing the place where\n\ 4531a function returns a value.\n\ 4532\n\ 4533On many machines, only @code{TYPE_MODE (@var{ret_type})} is relevant.\n\ 4534(Actually, on most machines, scalar values are returned in the same\n\ 4535place regardless of mode.) The value of the expression is usually a\n\ 4536@code{reg} RTX for the hard register where the return value is stored.\n\ 4537The value can also be a @code{parallel} RTX, if the return value is in\n\ 4538multiple places. See @code{TARGET_FUNCTION_ARG} for an explanation of the\n\ 4539@code{parallel} form. Note that the callee will populate every\n\ 4540location specified in the @code{parallel}, but if the first element of\n\ 4541the @code{parallel} contains the whole return value, callers will use\n\ 4542that element as the canonical location and ignore the others. The m68k\n\ 4543port uses this type of @code{parallel} to return pointers in both\n\ 4544@samp{%a0} (the canonical location) and @samp{%d0}.\n\ 4545\n\ 4546If @code{TARGET_PROMOTE_FUNCTION_RETURN} returns true, you must apply\n\ 4547the same promotion rules specified in @code{PROMOTE_MODE} if\n\ 4548@var{valtype} is a scalar type.\n\ 4549\n\ 4550If the precise function being called is known, @var{func} is a tree\n\ 4551node (@code{FUNCTION_DECL}) for it; otherwise, @var{func} is a null\n\ 4552pointer. This makes it possible to use a different value-returning\n\ 4553convention for specific functions when all their calls are\n\ 4554known.\n\ 4555\n\ 4556Some target machines have ``register windows'' so that the register in\n\ 4557which a function returns its value is not the same as the one in which\n\ 4558the caller sees the value. For such machines, you should return\n\ 4559different RTX depending on @var{outgoing}.\n\ 4560\n\ 4561@code{TARGET_FUNCTION_VALUE} is not used for return values with\n\ 4562aggregate data types, because these are returned in another way. See\n\ 4563@code{TARGET_STRUCT_VALUE_RTX} and related macros, below.", 4564 rtx, (const_tree ret_type, const_tree fn_decl_or_type, bool outgoing), 4565 default_function_value) 4566 4567/* Return the rtx for bounds of returned pointer. */ 4568DEFHOOK 4569(chkp_function_value_bounds, 4570 "Define this to return an RTX representing the place where a function\n\ 4571returns bounds for returned pointers. Arguments meaning is similar to\n\ 4572@code{TARGET_FUNCTION_VALUE}.", 4573 rtx, (const_tree ret_type, const_tree fn_decl_or_type, bool outgoing), 4574 default_chkp_function_value_bounds) 4575 4576/* Return the rtx for the result of a libcall of mode MODE, 4577 calling the function FN_NAME. */ 4578DEFHOOK 4579(libcall_value, 4580 "Define this hook if the back-end needs to know the name of the libcall\n\ 4581function in order to determine where the result should be returned.\n\ 4582\n\ 4583The mode of the result is given by @var{mode} and the name of the called\n\ 4584library function is given by @var{fun}. The hook should return an RTX\n\ 4585representing the place where the library function result will be returned.\n\ 4586\n\ 4587If this hook is not defined, then LIBCALL_VALUE will be used.", 4588 rtx, (machine_mode mode, const_rtx fun), 4589 default_libcall_value) 4590 4591/* Return true if REGNO is a possible register number for 4592 a function value as seen by the caller. */ 4593DEFHOOK 4594(function_value_regno_p, 4595 "A target hook that return @code{true} if @var{regno} is the number of a hard\n\ 4596register in which the values of called function may come back.\n\ 4597\n\ 4598A register whose use for returning values is limited to serving as the\n\ 4599second of a pair (for a value of type @code{double}, say) need not be\n\ 4600recognized by this target hook.\n\ 4601\n\ 4602If the machine has register windows, so that the caller and the called\n\ 4603function use different registers for the return value, this target hook\n\ 4604should recognize only the caller's register numbers.\n\ 4605\n\ 4606If this hook is not defined, then FUNCTION_VALUE_REGNO_P will be used.", 4607 bool, (const unsigned int regno), 4608 default_function_value_regno_p) 4609 4610/* ??? Documenting this hook requires a GFDL license grant. */ 4611DEFHOOK_UNDOC 4612(internal_arg_pointer, 4613"Return an rtx for the argument pointer incoming to the\ 4614 current function.", 4615 rtx, (void), 4616 default_internal_arg_pointer) 4617 4618/* Update the current function stack boundary if needed. */ 4619DEFHOOK 4620(update_stack_boundary, 4621 "Define this macro to update the current function stack boundary if\n\ 4622necessary.", 4623 void, (void), NULL) 4624 4625/* Handle stack alignment and return an rtx for Dynamic Realign 4626 Argument Pointer if necessary. */ 4627DEFHOOK 4628(get_drap_rtx, 4629 "This hook should return an rtx for Dynamic Realign Argument Pointer (DRAP) if a\n\ 4630different argument pointer register is needed to access the function's\n\ 4631argument list due to stack realignment. Return @code{NULL} if no DRAP\n\ 4632is needed.", 4633 rtx, (void), NULL) 4634 4635/* Return true if all function parameters should be spilled to the 4636 stack. */ 4637DEFHOOK 4638(allocate_stack_slots_for_args, 4639 "When optimization is disabled, this hook indicates whether or not\n\ 4640arguments should be allocated to stack slots. Normally, GCC allocates\n\ 4641stacks slots for arguments when not optimizing in order to make\n\ 4642debugging easier. However, when a function is declared with\n\ 4643@code{__attribute__((naked))}, there is no stack frame, and the compiler\n\ 4644cannot safely move arguments from the registers in which they are passed\n\ 4645to the stack. Therefore, this hook should return true in general, but\n\ 4646false for naked functions. The default implementation always returns true.", 4647 bool, (void), 4648 hook_bool_void_true) 4649 4650/* Return an rtx for the static chain for FNDECL_OR_TYPE. If INCOMING_P 4651 is true, then it should be for the callee; otherwise for the caller. */ 4652DEFHOOK 4653(static_chain, 4654 "This hook replaces the use of @code{STATIC_CHAIN_REGNUM} et al for\n\ 4655targets that may use different static chain locations for different\n\ 4656nested functions. This may be required if the target has function\n\ 4657attributes that affect the calling conventions of the function and\n\ 4658those calling conventions use different static chain locations.\n\ 4659\n\ 4660The default version of this hook uses @code{STATIC_CHAIN_REGNUM} et al.\n\ 4661\n\ 4662If the static chain is passed in memory, this hook should be used to\n\ 4663provide rtx giving @code{mem} expressions that denote where they are stored.\n\ 4664Often the @code{mem} expression as seen by the caller will be at an offset\n\ 4665from the stack pointer and the @code{mem} expression as seen by the callee\n\ 4666will be at an offset from the frame pointer.\n\ 4667@findex stack_pointer_rtx\n\ 4668@findex frame_pointer_rtx\n\ 4669@findex arg_pointer_rtx\n\ 4670The variables @code{stack_pointer_rtx}, @code{frame_pointer_rtx}, and\n\ 4671@code{arg_pointer_rtx} will have been initialized and should be used\n\ 4672to refer to those items.", 4673 rtx, (const_tree fndecl_or_type, bool incoming_p), 4674 default_static_chain) 4675 4676/* Fill in the trampoline at MEM with a call to FNDECL and a 4677 static chain value of CHAIN. */ 4678DEFHOOK 4679(trampoline_init, 4680 "This hook is called to initialize a trampoline.\n\ 4681@var{m_tramp} is an RTX for the memory block for the trampoline; @var{fndecl}\n\ 4682is the @code{FUNCTION_DECL} for the nested function; @var{static_chain} is an\n\ 4683RTX for the static chain value that should be passed to the function\n\ 4684when it is called.\n\ 4685\n\ 4686If the target defines @code{TARGET_ASM_TRAMPOLINE_TEMPLATE}, then the\n\ 4687first thing this hook should do is emit a block move into @var{m_tramp}\n\ 4688from the memory block returned by @code{assemble_trampoline_template}.\n\ 4689Note that the block move need only cover the constant parts of the\n\ 4690trampoline. If the target isolates the variable parts of the trampoline\n\ 4691to the end, not all @code{TRAMPOLINE_SIZE} bytes need be copied.\n\ 4692\n\ 4693If the target requires any other actions, such as flushing caches or\n\ 4694enabling stack execution, these actions should be performed after\n\ 4695initializing the trampoline proper.", 4696 void, (rtx m_tramp, tree fndecl, rtx static_chain), 4697 default_trampoline_init) 4698 4699/* Adjust the address of the trampoline in a target-specific way. */ 4700DEFHOOK 4701(trampoline_adjust_address, 4702 "This hook should perform any machine-specific adjustment in\n\ 4703the address of the trampoline. Its argument contains the address of the\n\ 4704memory block that was passed to @code{TARGET_TRAMPOLINE_INIT}. In case\n\ 4705the address to be used for a function call should be different from the\n\ 4706address at which the template was stored, the different address should\n\ 4707be returned; otherwise @var{addr} should be returned unchanged.\n\ 4708If this hook is not defined, @var{addr} will be used for function calls.", 4709 rtx, (rtx addr), NULL) 4710 4711/* Return the number of bytes of its own arguments that a function 4712 pops on returning, or 0 if the function pops no arguments and the 4713 caller must therefore pop them all after the function returns. */ 4714/* ??? tm.texi has no types for the parameters. */ 4715DEFHOOK 4716(return_pops_args, 4717 "This target hook returns the number of bytes of its own arguments that\n\ 4718a function pops on returning, or 0 if the function pops no arguments\n\ 4719and the caller must therefore pop them all after the function returns.\n\ 4720\n\ 4721@var{fundecl} is a C variable whose value is a tree node that describes\n\ 4722the function in question. Normally it is a node of type\n\ 4723@code{FUNCTION_DECL} that describes the declaration of the function.\n\ 4724From this you can obtain the @code{DECL_ATTRIBUTES} of the function.\n\ 4725\n\ 4726@var{funtype} is a C variable whose value is a tree node that\n\ 4727describes the function in question. Normally it is a node of type\n\ 4728@code{FUNCTION_TYPE} that describes the data type of the function.\n\ 4729From this it is possible to obtain the data types of the value and\n\ 4730arguments (if known).\n\ 4731\n\ 4732When a call to a library function is being considered, @var{fundecl}\n\ 4733will contain an identifier node for the library function. Thus, if\n\ 4734you need to distinguish among various library functions, you can do so\n\ 4735by their names. Note that ``library function'' in this context means\n\ 4736a function used to perform arithmetic, whose name is known specially\n\ 4737in the compiler and was not mentioned in the C code being compiled.\n\ 4738\n\ 4739@var{size} is the number of bytes of arguments passed on the\n\ 4740stack. If a variable number of bytes is passed, it is zero, and\n\ 4741argument popping will always be the responsibility of the calling function.\n\ 4742\n\ 4743On the VAX, all functions always pop their arguments, so the definition\n\ 4744of this macro is @var{size}. On the 68000, using the standard\n\ 4745calling convention, no functions pop their arguments, so the value of\n\ 4746the macro is always 0 in this case. But an alternative calling\n\ 4747convention is available in which functions that take a fixed number of\n\ 4748arguments pop them but other functions (such as @code{printf}) pop\n\ 4749nothing (the caller pops all). When this convention is in use,\n\ 4750@var{funtype} is examined to determine whether a function takes a fixed\n\ 4751number of arguments.", 4752 int, (tree fundecl, tree funtype, int size), 4753 default_return_pops_args) 4754 4755/* Return a mode wide enough to copy any function value that might be 4756 returned. */ 4757DEFHOOK 4758(get_raw_result_mode, 4759 "This target hook returns the mode to be used when accessing raw return\ 4760 registers in @code{__builtin_return}. Define this macro if the value\ 4761 in @var{reg_raw_mode} is not correct.", 4762 machine_mode, (int regno), 4763 default_get_reg_raw_mode) 4764 4765/* Return a mode wide enough to copy any argument value that might be 4766 passed. */ 4767DEFHOOK 4768(get_raw_arg_mode, 4769 "This target hook returns the mode to be used when accessing raw argument\ 4770 registers in @code{__builtin_apply_args}. Define this macro if the value\ 4771 in @var{reg_raw_mode} is not correct.", 4772 machine_mode, (int regno), 4773 default_get_reg_raw_mode) 4774 4775HOOK_VECTOR_END (calls) 4776 4777DEFHOOK 4778(use_pseudo_pic_reg, 4779 "This hook should return 1 in case pseudo register should be created\n\ 4780for pic_offset_table_rtx during function expand.", 4781 bool, (void), 4782 hook_bool_void_false) 4783 4784DEFHOOK 4785(init_pic_reg, 4786 "Perform a target dependent initialization of pic_offset_table_rtx.\n\ 4787This hook is called at the start of register allocation.", 4788 void, (void), 4789 hook_void_void) 4790 4791/* Return the diagnostic message string if conversion from FROMTYPE 4792 to TOTYPE is not allowed, NULL otherwise. */ 4793DEFHOOK 4794(invalid_conversion, 4795 "If defined, this macro returns the diagnostic message when it is\n\ 4796invalid to convert from @var{fromtype} to @var{totype}, or @code{NULL}\n\ 4797if validity should be determined by the front end.", 4798 const char *, (const_tree fromtype, const_tree totype), 4799 hook_constcharptr_const_tree_const_tree_null) 4800 4801/* Return the diagnostic message string if the unary operation OP is 4802 not permitted on TYPE, NULL otherwise. */ 4803DEFHOOK 4804(invalid_unary_op, 4805 "If defined, this macro returns the diagnostic message when it is\n\ 4806invalid to apply operation @var{op} (where unary plus is denoted by\n\ 4807@code{CONVERT_EXPR}) to an operand of type @var{type}, or @code{NULL}\n\ 4808if validity should be determined by the front end.", 4809 const char *, (int op, const_tree type), 4810 hook_constcharptr_int_const_tree_null) 4811 4812/* Return the diagnostic message string if the binary operation OP 4813 is not permitted on TYPE1 and TYPE2, NULL otherwise. */ 4814DEFHOOK 4815(invalid_binary_op, 4816 "If defined, this macro returns the diagnostic message when it is\n\ 4817invalid to apply operation @var{op} to operands of types @var{type1}\n\ 4818and @var{type2}, or @code{NULL} if validity should be determined by\n\ 4819the front end.", 4820 const char *, (int op, const_tree type1, const_tree type2), 4821 hook_constcharptr_int_const_tree_const_tree_null) 4822 4823/* Return the diagnostic message string if TYPE is not valid as a 4824 function parameter type, NULL otherwise. */ 4825DEFHOOK 4826(invalid_parameter_type, 4827 "If defined, this macro returns the diagnostic message when it is\n\ 4828invalid for functions to include parameters of type @var{type},\n\ 4829or @code{NULL} if validity should be determined by\n\ 4830the front end. This is currently used only by the C and C++ front ends.", 4831 const char *, (const_tree type), 4832 hook_constcharptr_const_tree_null) 4833 4834/* Return the diagnostic message string if TYPE is not valid as a 4835 function return type, NULL otherwise. */ 4836DEFHOOK 4837(invalid_return_type, 4838 "If defined, this macro returns the diagnostic message when it is\n\ 4839invalid for functions to have return type @var{type},\n\ 4840or @code{NULL} if validity should be determined by\n\ 4841the front end. This is currently used only by the C and C++ front ends.", 4842 const char *, (const_tree type), 4843 hook_constcharptr_const_tree_null) 4844 4845/* If values of TYPE are promoted to some other type when used in 4846 expressions (analogous to the integer promotions), return that type, 4847 or NULL_TREE otherwise. */ 4848DEFHOOK 4849(promoted_type, 4850 "If defined, this target hook returns the type to which values of\n\ 4851@var{type} should be promoted when they appear in expressions,\n\ 4852analogous to the integer promotions, or @code{NULL_TREE} to use the\n\ 4853front end's normal promotion rules. This hook is useful when there are\n\ 4854target-specific types with special promotion rules.\n\ 4855This is currently used only by the C and C++ front ends.", 4856 tree, (const_tree type), 4857 hook_tree_const_tree_null) 4858 4859/* Convert EXPR to TYPE, if target-specific types with special conversion 4860 rules are involved. Return the converted expression, or NULL to apply 4861 the standard conversion rules. */ 4862DEFHOOK 4863(convert_to_type, 4864 "If defined, this hook returns the result of converting @var{expr} to\n\ 4865@var{type}. It should return the converted expression,\n\ 4866or @code{NULL_TREE} to apply the front end's normal conversion rules.\n\ 4867This hook is useful when there are target-specific types with special\n\ 4868conversion rules.\n\ 4869This is currently used only by the C and C++ front ends.", 4870 tree, (tree type, tree expr), 4871 hook_tree_tree_tree_null) 4872 4873/* Change pseudo allocno class calculated by IRA. */ 4874DEFHOOK 4875(ira_change_pseudo_allocno_class, 4876 "A target hook which can change allocno class for given pseudo from\n\ 4877 allocno and best class calculated by IRA.\n\ 4878 \n\ 4879 The default version of this target hook always returns given class.", 4880 reg_class_t, (int, reg_class_t, reg_class_t), 4881 default_ira_change_pseudo_allocno_class) 4882 4883/* Return true if we use LRA instead of reload. */ 4884DEFHOOK 4885(lra_p, 4886 "A target hook which returns true if we use LRA instead of reload pass.\ 4887 \ 4888 The default version of this target hook returns always false, but new\ 4889 ports should use LRA.", 4890 bool, (void), 4891 default_lra_p) 4892 4893/* Return register priority of given hard regno for the current target. */ 4894DEFHOOK 4895(register_priority, 4896 "A target hook which returns the register priority number to which the\ 4897 register @var{hard_regno} belongs to. The bigger the number, the\ 4898 more preferable the hard register usage (when all other conditions are\ 4899 the same). This hook can be used to prefer some hard register over\ 4900 others in LRA. For example, some x86-64 register usage needs\ 4901 additional prefix which makes instructions longer. The hook can\ 4902 return lower priority number for such registers make them less favorable\ 4903 and as result making the generated code smaller.\ 4904 \ 4905 The default version of this target hook returns always zero.", 4906 int, (int), 4907 default_register_priority) 4908 4909/* Return true if we need register usage leveling. */ 4910DEFHOOK 4911(register_usage_leveling_p, 4912 "A target hook which returns true if we need register usage leveling.\ 4913 That means if a few hard registers are equally good for the\ 4914 assignment, we choose the least used hard register. The register\ 4915 usage leveling may be profitable for some targets. Don't use the\ 4916 usage leveling for targets with conditional execution or targets\ 4917 with big register files as it hurts if-conversion and cross-jumping\ 4918 optimizations.\ 4919 \ 4920 The default version of this target hook returns always false.", 4921 bool, (void), 4922 default_register_usage_leveling_p) 4923 4924/* Return true if maximal address displacement can be different. */ 4925DEFHOOK 4926(different_addr_displacement_p, 4927 "A target hook which returns true if an address with the same structure\ 4928 can have different maximal legitimate displacement. For example, the\ 4929 displacement can depend on memory mode or on operand combinations in\ 4930 the insn.\ 4931 \ 4932 The default version of this target hook returns always false.", 4933 bool, (void), 4934 default_different_addr_displacement_p) 4935 4936/* Determine class for spilling pseudos of given mode into registers 4937 instead of memory. */ 4938DEFHOOK 4939(spill_class, 4940 "This hook defines a class of registers which could be used for spilling\ 4941 pseudos of the given mode and class, or @code{NO_REGS} if only memory\ 4942 should be used. Not defining this hook is equivalent to returning\ 4943 @code{NO_REGS} for all inputs.", 4944 reg_class_t, (reg_class_t, machine_mode), 4945 NULL) 4946 4947DEFHOOK 4948(cstore_mode, 4949 "This hook defines the machine mode to use for the boolean result of\ 4950 conditional store patterns. The ICODE argument is the instruction code\ 4951 for the cstore being performed. Not definiting this hook is the same\ 4952 as accepting the mode encoded into operand 0 of the cstore expander\ 4953 patterns.", 4954 machine_mode, (enum insn_code icode), 4955 default_cstore_mode) 4956 4957/* True if a structure, union or array with MODE containing FIELD should 4958 be accessed using BLKmode. */ 4959DEFHOOK 4960(member_type_forces_blk, 4961 "Return true if a structure, union or array containing @var{field} should\n\ 4962be accessed using @code{BLKMODE}.\n\ 4963\n\ 4964If @var{field} is the only field in the structure, @var{mode} is its\n\ 4965mode, otherwise @var{mode} is VOIDmode. @var{mode} is provided in the\n\ 4966case where structures of one field would require the structure's mode to\n\ 4967retain the field's mode.\n\ 4968\n\ 4969Normally, this is not needed.", 4970 bool, (const_tree field, machine_mode mode), 4971 default_member_type_forces_blk) 4972 4973/* Return the class for a secondary reload, and fill in extra information. */ 4974DEFHOOK 4975(secondary_reload, 4976 "Many machines have some registers that cannot be copied directly to or\n\ 4977from memory or even from other types of registers. An example is the\n\ 4978@samp{MQ} register, which on most machines, can only be copied to or\n\ 4979from general registers, but not memory. Below, we shall be using the\n\ 4980term 'intermediate register' when a move operation cannot be performed\n\ 4981directly, but has to be done by copying the source into the intermediate\n\ 4982register first, and then copying the intermediate register to the\n\ 4983destination. An intermediate register always has the same mode as\n\ 4984source and destination. Since it holds the actual value being copied,\n\ 4985reload might apply optimizations to re-use an intermediate register\n\ 4986and eliding the copy from the source when it can determine that the\n\ 4987intermediate register still holds the required value.\n\ 4988\n\ 4989Another kind of secondary reload is required on some machines which\n\ 4990allow copying all registers to and from memory, but require a scratch\n\ 4991register for stores to some memory locations (e.g., those with symbolic\n\ 4992address on the RT, and those with certain symbolic address on the SPARC\n\ 4993when compiling PIC)@. Scratch registers need not have the same mode\n\ 4994as the value being copied, and usually hold a different value than\n\ 4995that being copied. Special patterns in the md file are needed to\n\ 4996describe how the copy is performed with the help of the scratch register;\n\ 4997these patterns also describe the number, register class(es) and mode(s)\n\ 4998of the scratch register(s).\n\ 4999\n\ 5000In some cases, both an intermediate and a scratch register are required.\n\ 5001\n\ 5002For input reloads, this target hook is called with nonzero @var{in_p},\n\ 5003and @var{x} is an rtx that needs to be copied to a register of class\n\ 5004@var{reload_class} in @var{reload_mode}. For output reloads, this target\n\ 5005hook is called with zero @var{in_p}, and a register of class @var{reload_class}\n\ 5006needs to be copied to rtx @var{x} in @var{reload_mode}.\n\ 5007\n\ 5008If copying a register of @var{reload_class} from/to @var{x} requires\n\ 5009an intermediate register, the hook @code{secondary_reload} should\n\ 5010return the register class required for this intermediate register.\n\ 5011If no intermediate register is required, it should return NO_REGS.\n\ 5012If more than one intermediate register is required, describe the one\n\ 5013that is closest in the copy chain to the reload register.\n\ 5014\n\ 5015If scratch registers are needed, you also have to describe how to\n\ 5016perform the copy from/to the reload register to/from this\n\ 5017closest intermediate register. Or if no intermediate register is\n\ 5018required, but still a scratch register is needed, describe the\n\ 5019copy from/to the reload register to/from the reload operand @var{x}.\n\ 5020\n\ 5021You do this by setting @code{sri->icode} to the instruction code of a pattern\n\ 5022in the md file which performs the move. Operands 0 and 1 are the output\n\ 5023and input of this copy, respectively. Operands from operand 2 onward are\n\ 5024for scratch operands. These scratch operands must have a mode, and a\n\ 5025single-register-class\n\ 5026@c [later: or memory]\n\ 5027output constraint.\n\ 5028\n\ 5029When an intermediate register is used, the @code{secondary_reload}\n\ 5030hook will be called again to determine how to copy the intermediate\n\ 5031register to/from the reload operand @var{x}, so your hook must also\n\ 5032have code to handle the register class of the intermediate operand.\n\ 5033\n\ 5034@c [For later: maybe we'll allow multi-alternative reload patterns -\n\ 5035@c the port maintainer could name a mov<mode> pattern that has clobbers -\n\ 5036@c and match the constraints of input and output to determine the required\n\ 5037@c alternative. A restriction would be that constraints used to match\n\ 5038@c against reloads registers would have to be written as register class\n\ 5039@c constraints, or we need a new target macro / hook that tells us if an\n\ 5040@c arbitrary constraint can match an unknown register of a given class.\n\ 5041@c Such a macro / hook would also be useful in other places.]\n\ 5042\n\ 5043\n\ 5044@var{x} might be a pseudo-register or a @code{subreg} of a\n\ 5045pseudo-register, which could either be in a hard register or in memory.\n\ 5046Use @code{true_regnum} to find out; it will return @minus{}1 if the pseudo is\n\ 5047in memory and the hard register number if it is in a register.\n\ 5048\n\ 5049Scratch operands in memory (constraint @code{\"=m\"} / @code{\"=&m\"}) are\n\ 5050currently not supported. For the time being, you will have to continue\n\ 5051to use @code{SECONDARY_MEMORY_NEEDED} for that purpose.\n\ 5052\n\ 5053@code{copy_cost} also uses this target hook to find out how values are\n\ 5054copied. If you want it to include some extra cost for the need to allocate\n\ 5055(a) scratch register(s), set @code{sri->extra_cost} to the additional cost.\n\ 5056Or if two dependent moves are supposed to have a lower cost than the sum\n\ 5057of the individual moves due to expected fortuitous scheduling and/or special\n\ 5058forwarding logic, you can set @code{sri->extra_cost} to a negative amount.", 5059 reg_class_t, 5060 (bool in_p, rtx x, reg_class_t reload_class, machine_mode reload_mode, 5061 secondary_reload_info *sri), 5062 default_secondary_reload) 5063 5064/* Given an rtx X being reloaded into a reg required to be in class CLASS, 5065 return the class of reg to actually use. */ 5066DEFHOOK 5067(preferred_reload_class, 5068 "A target hook that places additional restrictions on the register class\n\ 5069to use when it is necessary to copy value @var{x} into a register in class\n\ 5070@var{rclass}. The value is a register class; perhaps @var{rclass}, or perhaps\n\ 5071another, smaller class.\n\ 5072\n\ 5073The default version of this hook always returns value of @code{rclass} argument.\n\ 5074\n\ 5075Sometimes returning a more restrictive class makes better code. For\n\ 5076example, on the 68000, when @var{x} is an integer constant that is in range\n\ 5077for a @samp{moveq} instruction, the value of this macro is always\n\ 5078@code{DATA_REGS} as long as @var{rclass} includes the data registers.\n\ 5079Requiring a data register guarantees that a @samp{moveq} will be used.\n\ 5080\n\ 5081One case where @code{TARGET_PREFERRED_RELOAD_CLASS} must not return\n\ 5082@var{rclass} is if @var{x} is a legitimate constant which cannot be\n\ 5083loaded into some register class. By returning @code{NO_REGS} you can\n\ 5084force @var{x} into a memory location. For example, rs6000 can load\n\ 5085immediate values into general-purpose registers, but does not have an\n\ 5086instruction for loading an immediate value into a floating-point\n\ 5087register, so @code{TARGET_PREFERRED_RELOAD_CLASS} returns @code{NO_REGS} when\n\ 5088@var{x} is a floating-point constant. If the constant can't be loaded\n\ 5089into any kind of register, code generation will be better if\n\ 5090@code{TARGET_LEGITIMATE_CONSTANT_P} makes the constant illegitimate instead\n\ 5091of using @code{TARGET_PREFERRED_RELOAD_CLASS}.\n\ 5092\n\ 5093If an insn has pseudos in it after register allocation, reload will go\n\ 5094through the alternatives and call repeatedly @code{TARGET_PREFERRED_RELOAD_CLASS}\n\ 5095to find the best one. Returning @code{NO_REGS}, in this case, makes\n\ 5096reload add a @code{!} in front of the constraint: the x86 back-end uses\n\ 5097this feature to discourage usage of 387 registers when math is done in\n\ 5098the SSE registers (and vice versa).", 5099 reg_class_t, 5100 (rtx x, reg_class_t rclass), 5101 default_preferred_reload_class) 5102 5103/* Like TARGET_PREFERRED_RELOAD_CLASS, but for output reloads instead of 5104 input reloads. */ 5105DEFHOOK 5106(preferred_output_reload_class, 5107 "Like @code{TARGET_PREFERRED_RELOAD_CLASS}, but for output reloads instead of\n\ 5108input reloads.\n\ 5109\n\ 5110The default version of this hook always returns value of @code{rclass}\n\ 5111argument.\n\ 5112\n\ 5113You can also use @code{TARGET_PREFERRED_OUTPUT_RELOAD_CLASS} to discourage\n\ 5114reload from using some alternatives, like @code{TARGET_PREFERRED_RELOAD_CLASS}.", 5115 reg_class_t, 5116 (rtx x, reg_class_t rclass), 5117 default_preferred_output_reload_class) 5118 5119DEFHOOK 5120(class_likely_spilled_p, 5121 "A target hook which returns @code{true} if pseudos that have been assigned\n\ 5122to registers of class @var{rclass} would likely be spilled because\n\ 5123registers of @var{rclass} are needed for spill registers.\n\ 5124\n\ 5125The default version of this target hook returns @code{true} if @var{rclass}\n\ 5126has exactly one register and @code{false} otherwise. On most machines, this\n\ 5127default should be used. For generally register-starved machines, such as\n\ 5128i386, or machines with right register constraints, such as SH, this hook\n\ 5129can be used to avoid excessive spilling.\n\ 5130\n\ 5131This hook is also used by some of the global intra-procedural code\n\ 5132transformations to throtle code motion, to avoid increasing register\n\ 5133pressure.", 5134 bool, (reg_class_t rclass), 5135 default_class_likely_spilled_p) 5136 5137/* Return the maximum number of consecutive registers 5138 needed to represent mode MODE in a register of class RCLASS. */ 5139DEFHOOK 5140(class_max_nregs, 5141 "A target hook returns the maximum number of consecutive registers\n\ 5142of class @var{rclass} needed to hold a value of mode @var{mode}.\n\ 5143\n\ 5144This is closely related to the macro @code{HARD_REGNO_NREGS}. In fact,\n\ 5145the value returned by @code{TARGET_CLASS_MAX_NREGS (@var{rclass},\n\ 5146@var{mode})} target hook should be the maximum value of\n\ 5147@code{HARD_REGNO_NREGS (@var{regno}, @var{mode})} for all @var{regno}\n\ 5148values in the class @var{rclass}.\n\ 5149\n\ 5150This target hook helps control the handling of multiple-word values\n\ 5151in the reload pass.\n\ 5152\n\ 5153The default version of this target hook returns the size of @var{mode}\n\ 5154in words.", 5155 unsigned char, (reg_class_t rclass, machine_mode mode), 5156 default_class_max_nregs) 5157 5158DEFHOOK 5159(preferred_rename_class, 5160 "A target hook that places additional preference on the register\ 5161 class to use when it is necessary to rename a register in class\ 5162 @var{rclass} to another class, or perhaps @var{NO_REGS}, if no\ 5163 preferred register class is found or hook @code{preferred_rename_class}\ 5164 is not implemented.\ 5165 Sometimes returning a more restrictive class makes better code. For\ 5166 example, on ARM, thumb-2 instructions using @code{LO_REGS} may be\ 5167 smaller than instructions using @code{GENERIC_REGS}. By returning\ 5168 @code{LO_REGS} from @code{preferred_rename_class}, code size can\ 5169 be reduced.", 5170 reg_class_t, (reg_class_t rclass), 5171 default_preferred_rename_class) 5172 5173/* This target hook allows the backend to avoid unsafe substitution 5174 during register allocation. */ 5175DEFHOOK 5176(cannot_substitute_mem_equiv_p, 5177 "A target hook which returns @code{true} if @var{subst} can't\n\ 5178substitute safely pseudos with equivalent memory values during\n\ 5179register allocation.\n\ 5180The default version of this target hook returns @code{false}.\n\ 5181On most machines, this default should be used. For generally\n\ 5182machines with non orthogonal register usage for addressing, such\n\ 5183as SH, this hook can be used to avoid excessive spilling.", 5184 bool, (rtx subst), 5185 hook_bool_rtx_false) 5186 5187/* This target hook allows the backend to legitimize base plus 5188 displacement addressing. */ 5189DEFHOOK 5190(legitimize_address_displacement, 5191 "A target hook which returns @code{true} if *@var{disp} is\n\ 5192legitimezed to valid address displacement with subtracting *@var{offset}\n\ 5193at memory mode @var{mode}.\n\ 5194The default version of this target hook returns @code{false}.\n\ 5195This hook will benefit machines with limited base plus displacement\n\ 5196addressing.", 5197 bool, (rtx *disp, rtx *offset, machine_mode mode), 5198 default_legitimize_address_displacement) 5199 5200/* This target hook allows the backend to perform additional 5201 processing while initializing for variable expansion. */ 5202DEFHOOK 5203(expand_to_rtl_hook, 5204 "This hook is called just before expansion into rtl, allowing the target\n\ 5205to perform additional initializations or analysis before the expansion.\n\ 5206For example, the rs6000 port uses it to allocate a scratch stack slot\n\ 5207for use in copying SDmode values between memory and floating point\n\ 5208registers whenever the function being expanded has any SDmode\n\ 5209usage.", 5210 void, (void), 5211 hook_void_void) 5212 5213/* This target hook allows the backend to perform additional 5214 instantiations on rtx that are not actually in insns yet, 5215 but will be later. */ 5216DEFHOOK 5217(instantiate_decls, 5218 "This hook allows the backend to perform additional instantiations on rtl\n\ 5219that are not actually in any insns yet, but will be later.", 5220 void, (void), 5221 hook_void_void) 5222 5223/* Return true if is OK to use a hard register REGNO as scratch register 5224 in peephole2. */ 5225DEFHOOK 5226(hard_regno_scratch_ok, 5227 "This target hook should return @code{true} if it is OK to use a hard register\n\ 5228@var{regno} as scratch reg in peephole2.\n\ 5229\n\ 5230One common use of this macro is to prevent using of a register that\n\ 5231is not saved by a prologue in an interrupt handler.\n\ 5232\n\ 5233The default version of this hook always returns @code{true}.", 5234 bool, (unsigned int regno), 5235 default_hard_regno_scratch_ok) 5236 5237/* Return the smallest number of different values for which it is best to 5238 use a jump-table instead of a tree of conditional branches. */ 5239DEFHOOK 5240(case_values_threshold, 5241 "This function return the smallest number of different values for which it\n\ 5242is best to use a jump-table instead of a tree of conditional branches.\n\ 5243The default is four for machines with a @code{casesi} instruction and\n\ 5244five otherwise. This is best for most machines.", 5245 unsigned int, (void), 5246 default_case_values_threshold) 5247 5248/* Retutn true if a function must have and use a frame pointer. */ 5249DEFHOOK 5250(frame_pointer_required, 5251 "This target hook should return @code{true} if a function must have and use\n\ 5252a frame pointer. This target hook is called in the reload pass. If its return\n\ 5253value is @code{true} the function will have a frame pointer.\n\ 5254\n\ 5255This target hook can in principle examine the current function and decide\n\ 5256according to the facts, but on most machines the constant @code{false} or the\n\ 5257constant @code{true} suffices. Use @code{false} when the machine allows code\n\ 5258to be generated with no frame pointer, and doing so saves some time or space.\n\ 5259Use @code{true} when there is no possible advantage to avoiding a frame\n\ 5260pointer.\n\ 5261\n\ 5262In certain cases, the compiler does not know how to produce valid code\n\ 5263without a frame pointer. The compiler recognizes those cases and\n\ 5264automatically gives the function a frame pointer regardless of what\n\ 5265@code{TARGET_FRAME_POINTER_REQUIRED} returns. You don't need to worry about\n\ 5266them.\n\ 5267\n\ 5268In a function that does not require a frame pointer, the frame pointer\n\ 5269register can be allocated for ordinary usage, unless you mark it as a\n\ 5270fixed register. See @code{FIXED_REGISTERS} for more information.\n\ 5271\n\ 5272Default return value is @code{false}.", 5273 bool, (void), 5274 hook_bool_void_false) 5275 5276/* Returns true if the compiler is allowed to try to replace register number 5277 from-reg with register number to-reg. */ 5278DEFHOOK 5279(can_eliminate, 5280 "This target hook should returns @code{true} if the compiler is allowed to\n\ 5281try to replace register number @var{from_reg} with register number\n\ 5282@var{to_reg}. This target hook need only be defined if @code{ELIMINABLE_REGS}\n\ 5283is defined, and will usually be @code{true}, since most of the cases\n\ 5284preventing register elimination are things that the compiler already\n\ 5285knows about.\n\ 5286\n\ 5287Default return value is @code{true}.", 5288 bool, (const int from_reg, const int to_reg), 5289 hook_bool_const_int_const_int_true) 5290 5291/* Modify any or all of fixed_regs, call_used_regs, global_regs, 5292 reg_names, and reg_class_contents to account of the vagaries of the 5293 target. */ 5294DEFHOOK 5295(conditional_register_usage, 5296 "This hook may conditionally modify five variables\n\ 5297@code{fixed_regs}, @code{call_used_regs}, @code{global_regs},\n\ 5298@code{reg_names}, and @code{reg_class_contents}, to take into account\n\ 5299any dependence of these register sets on target flags. The first three\n\ 5300of these are of type @code{char []} (interpreted as Boolean vectors).\n\ 5301@code{global_regs} is a @code{const char *[]}, and\n\ 5302@code{reg_class_contents} is a @code{HARD_REG_SET}. Before the macro is\n\ 5303called, @code{fixed_regs}, @code{call_used_regs},\n\ 5304@code{reg_class_contents}, and @code{reg_names} have been initialized\n\ 5305from @code{FIXED_REGISTERS}, @code{CALL_USED_REGISTERS},\n\ 5306@code{REG_CLASS_CONTENTS}, and @code{REGISTER_NAMES}, respectively.\n\ 5307@code{global_regs} has been cleared, and any @option{-ffixed-@var{reg}},\n\ 5308@option{-fcall-used-@var{reg}} and @option{-fcall-saved-@var{reg}}\n\ 5309command options have been applied.\n\ 5310\n\ 5311@cindex disabling certain registers\n\ 5312@cindex controlling register usage\n\ 5313If the usage of an entire class of registers depends on the target\n\ 5314flags, you may indicate this to GCC by using this macro to modify\n\ 5315@code{fixed_regs} and @code{call_used_regs} to 1 for each of the\n\ 5316registers in the classes which should not be used by GCC@. Also make\n\ 5317@code{define_register_constraint}s return @code{NO_REGS} for constraints\n\ 5318that shouldn't be used.\n\ 5319\n\ 5320(However, if this class is not included in @code{GENERAL_REGS} and all\n\ 5321of the insn patterns whose constraints permit this class are\n\ 5322controlled by target switches, then GCC will automatically avoid using\n\ 5323these registers when the target switches are opposed to them.)", 5324 void, (void), 5325 hook_void_void) 5326 5327/* Functions specific to the C family of frontends. */ 5328#undef HOOK_PREFIX 5329#define HOOK_PREFIX "TARGET_C_" 5330HOOK_VECTOR (TARGET_C, c) 5331 5332/* ??? Documenting this hook requires a GFDL license grant. */ 5333DEFHOOK_UNDOC 5334(mode_for_suffix, 5335"Return machine mode for non-standard constant literal suffix @var{c},\ 5336 or VOIDmode if non-standard suffixes are unsupported.", 5337 machine_mode, (char c), 5338 default_mode_for_suffix) 5339 5340HOOK_VECTOR_END (c) 5341 5342/* Functions specific to the C++ frontend. */ 5343#undef HOOK_PREFIX 5344#define HOOK_PREFIX "TARGET_CXX_" 5345HOOK_VECTOR (TARGET_CXX, cxx) 5346 5347/* Return the integer type used for guard variables. */ 5348DEFHOOK 5349(guard_type, 5350 "Define this hook to override the integer type used for guard variables.\n\ 5351These are used to implement one-time construction of static objects. The\n\ 5352default is long_long_integer_type_node.", 5353 tree, (void), 5354 default_cxx_guard_type) 5355 5356/* Return true if only the low bit of the guard should be tested. */ 5357DEFHOOK 5358(guard_mask_bit, 5359 "This hook determines how guard variables are used. It should return\n\ 5360@code{false} (the default) if the first byte should be used. A return value of\n\ 5361@code{true} indicates that only the least significant bit should be used.", 5362 bool, (void), 5363 hook_bool_void_false) 5364 5365/* Returns the size of the array cookie for an array of type. */ 5366DEFHOOK 5367(get_cookie_size, 5368 "This hook returns the size of the cookie to use when allocating an array\n\ 5369whose elements have the indicated @var{type}. Assumes that it is already\n\ 5370known that a cookie is needed. The default is\n\ 5371@code{max(sizeof (size_t), alignof(type))}, as defined in section 2.7 of the\n\ 5372IA64/Generic C++ ABI@.", 5373 tree, (tree type), 5374 default_cxx_get_cookie_size) 5375 5376/* Returns true if the element size should be stored in the array cookie. */ 5377DEFHOOK 5378(cookie_has_size, 5379 "This hook should return @code{true} if the element size should be stored in\n\ 5380array cookies. The default is to return @code{false}.", 5381 bool, (void), 5382 hook_bool_void_false) 5383 5384/* Allows backends to perform additional processing when 5385 deciding if a class should be exported or imported. */ 5386DEFHOOK 5387(import_export_class, 5388 "If defined by a backend this hook allows the decision made to export\n\ 5389class @var{type} to be overruled. Upon entry @var{import_export}\n\ 5390will contain 1 if the class is going to be exported, @minus{}1 if it is going\n\ 5391to be imported and 0 otherwise. This function should return the\n\ 5392modified value and perform any other actions necessary to support the\n\ 5393backend's targeted operating system.", 5394 int, (tree type, int import_export), NULL) 5395 5396/* Returns true if constructors and destructors return "this". */ 5397DEFHOOK 5398(cdtor_returns_this, 5399 "This hook should return @code{true} if constructors and destructors return\n\ 5400the address of the object created/destroyed. The default is to return\n\ 5401@code{false}.", 5402 bool, (void), 5403 hook_bool_void_false) 5404 5405/* Returns true if the key method for a class can be an inline 5406 function, so long as it is not declared inline in the class 5407 itself. Returning true is the behavior required by the Itanium C++ ABI. */ 5408DEFHOOK 5409(key_method_may_be_inline, 5410 "This hook returns true if the key method for a class (i.e., the method\n\ 5411which, if defined in the current translation unit, causes the virtual\n\ 5412table to be emitted) may be an inline function. Under the standard\n\ 5413Itanium C++ ABI the key method may be an inline function so long as\n\ 5414the function is not declared inline in the class definition. Under\n\ 5415some variants of the ABI, an inline function can never be the key\n\ 5416method. The default is to return @code{true}.", 5417 bool, (void), 5418 hook_bool_void_true) 5419 5420DEFHOOK 5421(determine_class_data_visibility, 5422"@var{decl} is a virtual table, virtual table table, typeinfo object,\ 5423 or other similar implicit class data object that will be emitted with\ 5424 external linkage in this translation unit. No ELF visibility has been\ 5425 explicitly specified. If the target needs to specify a visibility\ 5426 other than that of the containing class, use this hook to set\ 5427 @code{DECL_VISIBILITY} and @code{DECL_VISIBILITY_SPECIFIED}.", 5428 void, (tree decl), 5429 hook_void_tree) 5430 5431/* Returns true (the default) if virtual tables and other 5432 similar implicit class data objects are always COMDAT if they 5433 have external linkage. If this hook returns false, then 5434 class data for classes whose virtual table will be emitted in 5435 only one translation unit will not be COMDAT. */ 5436DEFHOOK 5437(class_data_always_comdat, 5438 "This hook returns true (the default) if virtual tables and other\n\ 5439similar implicit class data objects are always COMDAT if they have\n\ 5440external linkage. If this hook returns false, then class data for\n\ 5441classes whose virtual table will be emitted in only one translation\n\ 5442unit will not be COMDAT.", 5443 bool, (void), 5444 hook_bool_void_true) 5445 5446/* Returns true (the default) if the RTTI for the basic types, 5447 which is always defined in the C++ runtime, should be COMDAT; 5448 false if it should not be COMDAT. */ 5449DEFHOOK 5450(library_rtti_comdat, 5451 "This hook returns true (the default) if the RTTI information for\n\ 5452the basic types which is defined in the C++ runtime should always\n\ 5453be COMDAT, false if it should not be COMDAT.", 5454 bool, (void), 5455 hook_bool_void_true) 5456 5457/* Returns true if __aeabi_atexit should be used to register static 5458 destructors. */ 5459DEFHOOK 5460(use_aeabi_atexit, 5461 "This hook returns true if @code{__aeabi_atexit} (as defined by the ARM EABI)\n\ 5462should be used to register static destructors when @option{-fuse-cxa-atexit}\n\ 5463is in effect. The default is to return false to use @code{__cxa_atexit}.", 5464 bool, (void), 5465 hook_bool_void_false) 5466 5467/* Returns true if target may use atexit in the same manner as 5468 __cxa_atexit to register static destructors. */ 5469DEFHOOK 5470(use_atexit_for_cxa_atexit, 5471 "This hook returns true if the target @code{atexit} function can be used\n\ 5472in the same manner as @code{__cxa_atexit} to register C++ static\n\ 5473destructors. This requires that @code{atexit}-registered functions in\n\ 5474shared libraries are run in the correct order when the libraries are\n\ 5475unloaded. The default is to return false.", 5476 bool, (void), 5477 hook_bool_void_false) 5478 5479DEFHOOK 5480(adjust_class_at_definition, 5481"@var{type} is a C++ class (i.e., RECORD_TYPE or UNION_TYPE) that has just\ 5482 been defined. Use this hook to make adjustments to the class (eg, tweak\ 5483 visibility or perform any other required target modifications).", 5484 void, (tree type), 5485 hook_void_tree) 5486 5487DEFHOOK 5488(decl_mangling_context, 5489 "Return target-specific mangling context of @var{decl} or @code{NULL_TREE}.", 5490 tree, (const_tree decl), 5491 hook_tree_const_tree_null) 5492 5493HOOK_VECTOR_END (cxx) 5494 5495/* Functions and data for emulated TLS support. */ 5496#undef HOOK_PREFIX 5497#define HOOK_PREFIX "TARGET_EMUTLS_" 5498HOOK_VECTOR (TARGET_EMUTLS, emutls) 5499 5500/* Name of the address and common functions. */ 5501DEFHOOKPOD 5502(get_address, 5503 "Contains the name of the helper function that uses a TLS control\n\ 5504object to locate a TLS instance. The default causes libgcc's\n\ 5505emulated TLS helper function to be used.", 5506 const char *, "__builtin___emutls_get_address") 5507 5508DEFHOOKPOD 5509(register_common, 5510 "Contains the name of the helper function that should be used at\n\ 5511program startup to register TLS objects that are implicitly\n\ 5512initialized to zero. If this is @code{NULL}, all TLS objects will\n\ 5513have explicit initializers. The default causes libgcc's emulated TLS\n\ 5514registration function to be used.", 5515 const char *, "__builtin___emutls_register_common") 5516 5517/* Prefixes for proxy variable and template. */ 5518DEFHOOKPOD 5519(var_section, 5520 "Contains the name of the section in which TLS control variables should\n\ 5521be placed. The default of @code{NULL} allows these to be placed in\n\ 5522any section.", 5523 const char *, NULL) 5524 5525DEFHOOKPOD 5526(tmpl_section, 5527 "Contains the name of the section in which TLS initializers should be\n\ 5528placed. The default of @code{NULL} allows these to be placed in any\n\ 5529section.", 5530 const char *, NULL) 5531 5532/* Prefixes for proxy variable and template. */ 5533DEFHOOKPOD 5534(var_prefix, 5535 "Contains the prefix to be prepended to TLS control variable names.\n\ 5536The default of @code{NULL} uses a target-specific prefix.", 5537 const char *, NULL) 5538 5539DEFHOOKPOD 5540(tmpl_prefix, 5541 "Contains the prefix to be prepended to TLS initializer objects. The\n\ 5542default of @code{NULL} uses a target-specific prefix.", 5543 const char *, NULL) 5544 5545/* Function to generate field definitions of the proxy variable. */ 5546DEFHOOK 5547(var_fields, 5548 "Specifies a function that generates the FIELD_DECLs for a TLS control\n\ 5549object type. @var{type} is the RECORD_TYPE the fields are for and\n\ 5550@var{name} should be filled with the structure tag, if the default of\n\ 5551@code{__emutls_object} is unsuitable. The default creates a type suitable\n\ 5552for libgcc's emulated TLS function.", 5553 tree, (tree type, tree *name), 5554 default_emutls_var_fields) 5555 5556/* Function to initialize a proxy variable. */ 5557DEFHOOK 5558(var_init, 5559 "Specifies a function that generates the CONSTRUCTOR to initialize a\n\ 5560TLS control object. @var{var} is the TLS control object, @var{decl}\n\ 5561is the TLS object and @var{tmpl_addr} is the address of the\n\ 5562initializer. The default initializes libgcc's emulated TLS control object.", 5563 tree, (tree var, tree decl, tree tmpl_addr), 5564 default_emutls_var_init) 5565 5566/* Whether we are allowed to alter the usual alignment of the 5567 proxy variable. */ 5568DEFHOOKPOD 5569(var_align_fixed, 5570 "Specifies whether the alignment of TLS control variable objects is\n\ 5571fixed and should not be increased as some backends may do to optimize\n\ 5572single objects. The default is false.", 5573 bool, false) 5574 5575/* Whether we can emit debug information for TLS vars. */ 5576DEFHOOKPOD 5577(debug_form_tls_address, 5578 "Specifies whether a DWARF @code{DW_OP_form_tls_address} location descriptor\n\ 5579may be used to describe emulated TLS control objects.", 5580 bool, false) 5581 5582HOOK_VECTOR_END (emutls) 5583 5584#undef HOOK_PREFIX 5585#define HOOK_PREFIX "TARGET_OPTION_" 5586HOOK_VECTOR (TARGET_OPTION_HOOKS, target_option_hooks) 5587 5588/* Function to validate the attribute((target(...))) strings. If 5589 the option is validated, the hook should also fill in 5590 DECL_FUNCTION_SPECIFIC_TARGET in the function decl node. */ 5591DEFHOOK 5592(valid_attribute_p, 5593 "This hook is called to parse @code{attribute(target(\"...\"))}, which\n\ 5594allows setting target-specific options on individual functions.\n\ 5595These function-specific options may differ\n\ 5596from the options specified on the command line. The hook should return\n\ 5597@code{true} if the options are valid.\n\ 5598\n\ 5599The hook should set the @code{DECL_FUNCTION_SPECIFIC_TARGET} field in\n\ 5600the function declaration to hold a pointer to a target-specific\n\ 5601@code{struct cl_target_option} structure.", 5602 bool, (tree fndecl, tree name, tree args, int flags), 5603 default_target_option_valid_attribute_p) 5604 5605/* Function to save any extra target state in the target options structure. */ 5606DEFHOOK 5607(save, 5608 "This hook is called to save any additional target-specific information\n\ 5609in the @code{struct cl_target_option} structure for function-specific\n\ 5610options from the @code{struct gcc_options} structure.\n\ 5611@xref{Option file format}.", 5612 void, (struct cl_target_option *ptr, struct gcc_options *opts), NULL) 5613 5614/* Function to restore any extra target state from the target options 5615 structure. */ 5616DEFHOOK 5617(restore, 5618 "This hook is called to restore any additional target-specific\n\ 5619information in the @code{struct cl_target_option} structure for\n\ 5620function-specific options to the @code{struct gcc_options} structure.", 5621 void, (struct gcc_options *opts, struct cl_target_option *ptr), NULL) 5622 5623/* Function to update target-specific option information after being 5624 streamed in. */ 5625DEFHOOK 5626(post_stream_in, 5627 "This hook is called to update target-specific information in the\n\ 5628@code{struct cl_target_option} structure after it is streamed in from\n\ 5629LTO bytecode.", 5630 void, (struct cl_target_option *ptr), NULL) 5631 5632/* Function to print any extra target state from the target options 5633 structure. */ 5634DEFHOOK 5635(print, 5636 "This hook is called to print any additional target-specific\n\ 5637information in the @code{struct cl_target_option} structure for\n\ 5638function-specific options.", 5639 void, (FILE *file, int indent, struct cl_target_option *ptr), NULL) 5640 5641/* Function to parse arguments to be validated for #pragma target, and to 5642 change the state if the options are valid. If the first argument is 5643 NULL, the second argument specifies the default options to use. Return 5644 true if the options are valid, and set the current state. */ 5645DEFHOOK 5646(pragma_parse, 5647 "This target hook parses the options for @code{#pragma GCC target}, which\n\ 5648sets the target-specific options for functions that occur later in the\n\ 5649input stream. The options accepted should be the same as those handled by the\n\ 5650@code{TARGET_OPTION_VALID_ATTRIBUTE_P} hook.", 5651 bool, (tree args, tree pop_target), 5652 default_target_option_pragma_parse) 5653 5654/* Do option overrides for the target. */ 5655DEFHOOK 5656(override, 5657 "Sometimes certain combinations of command options do not make sense on\n\ 5658a particular target machine. You can override the hook\n\ 5659@code{TARGET_OPTION_OVERRIDE} to take account of this. This hooks is called\n\ 5660once just after all the command options have been parsed.\n\ 5661\n\ 5662Don't use this hook to turn on various extra optimizations for\n\ 5663@option{-O}. That is what @code{TARGET_OPTION_OPTIMIZATION} is for.\n\ 5664\n\ 5665If you need to do something whenever the optimization level is\n\ 5666changed via the optimize attribute or pragma, see\n\ 5667@code{TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE}", 5668 void, (void), 5669 hook_void_void) 5670 5671/* This function returns true if DECL1 and DECL2 are versions of the same 5672 function. DECL1 and DECL2 are function versions if and only if they 5673 have the same function signature and different target specific attributes, 5674 that is, they are compiled for different target machines. */ 5675DEFHOOK 5676(function_versions, 5677 "This target hook returns @code{true} if @var{DECL1} and @var{DECL2} are\n\ 5678versions of the same function. @var{DECL1} and @var{DECL2} are function\n\ 5679versions if and only if they have the same function signature and\n\ 5680different target specific attributes, that is, they are compiled for\n\ 5681different target machines.", 5682 bool, (tree decl1, tree decl2), 5683 hook_bool_tree_tree_false) 5684 5685/* Function to determine if one function can inline another function. */ 5686#undef HOOK_PREFIX 5687#define HOOK_PREFIX "TARGET_" 5688DEFHOOK 5689(can_inline_p, 5690 "This target hook returns @code{false} if the @var{caller} function\n\ 5691cannot inline @var{callee}, based on target specific information. By\n\ 5692default, inlining is not allowed if the callee function has function\n\ 5693specific target options and the caller does not use the same options.", 5694 bool, (tree caller, tree callee), 5695 default_target_can_inline_p) 5696 5697DEFHOOK 5698(relayout_function, 5699"This target hook fixes function @var{fndecl} after attributes are processed. Default does nothing. On ARM, the default function's alignment is updated with the attribute target.", 5700 void, (tree fndecl), 5701 hook_void_tree) 5702 5703HOOK_VECTOR_END (target_option) 5704 5705/* For targets that need to mark extra registers as live on entry to 5706 the function, they should define this target hook and set their 5707 bits in the bitmap passed in. */ 5708DEFHOOK 5709(extra_live_on_entry, 5710 "Add any hard registers to @var{regs} that are live on entry to the\n\ 5711function. This hook only needs to be defined to provide registers that\n\ 5712cannot be found by examination of FUNCTION_ARG_REGNO_P, the callee saved\n\ 5713registers, STATIC_CHAIN_INCOMING_REGNUM, STATIC_CHAIN_REGNUM,\n\ 5714TARGET_STRUCT_VALUE_RTX, FRAME_POINTER_REGNUM, EH_USES,\n\ 5715FRAME_POINTER_REGNUM, ARG_POINTER_REGNUM, and the PIC_OFFSET_TABLE_REGNUM.", 5716 void, (bitmap regs), 5717 hook_void_bitmap) 5718 5719/* Targets should define this target hook to mark that non-callee clobbers are 5720 present in CALL_INSN_FUNCTION_USAGE for all the calls that bind to a local 5721 definition. */ 5722DEFHOOKPOD 5723(call_fusage_contains_non_callee_clobbers, 5724 "Set to true if each call that binds to a local definition explicitly\n\ 5725clobbers or sets all non-fixed registers modified by performing the call.\n\ 5726That is, by the call pattern itself, or by code that might be inserted by the\n\ 5727linker (e.g. stubs, veneers, branch islands), but not including those\n\ 5728modifiable by the callee. The affected registers may be mentioned explicitly\n\ 5729in the call pattern, or included as clobbers in CALL_INSN_FUNCTION_USAGE.\n\ 5730The default version of this hook is set to false. The purpose of this hook\n\ 5731is to enable the fipa-ra optimization.", 5732 bool, 5733 false) 5734 5735/* Fill in additional registers set up by prologue into a regset. */ 5736DEFHOOK 5737(set_up_by_prologue, 5738 "This hook should add additional registers that are computed by the prologue\ 5739 to the hard regset for shrink-wrapping optimization purposes.", 5740 void, (struct hard_reg_set_container *), 5741 NULL) 5742 5743/* For targets that have attributes that can affect whether a 5744 function's return statements need checking. For instance a 'naked' 5745 function attribute. */ 5746DEFHOOK 5747(warn_func_return, 5748 "True if a function's return statements should be checked for matching the function's return type. This includes checking for falling off the end of a non-void function. Return false if no such check should be made.", 5749 bool, (tree), 5750 hook_bool_tree_true) 5751 5752/* Determine the type of unwind info to emit for debugging. */ 5753DEFHOOK 5754(debug_unwind_info, 5755 "This hook defines the mechanism that will be used for describing frame\n\ 5756unwind information to the debugger. Normally the hook will return\n\ 5757@code{UI_DWARF2} if DWARF 2 debug information is enabled, and\n\ 5758return @code{UI_NONE} otherwise.\n\ 5759\n\ 5760A target may return @code{UI_DWARF2} even when DWARF 2 debug information\n\ 5761is disabled in order to always output DWARF 2 frame information.\n\ 5762\n\ 5763A target may return @code{UI_TARGET} if it has ABI specified unwind tables.\n\ 5764This will suppress generation of the normal debug frame unwind information.", 5765 enum unwind_info_type, (void), 5766 default_debug_unwind_info) 5767 5768/* The code parameter should be of type enum rtx_code but this is not 5769 defined at this time. */ 5770DEFHOOK 5771(canonicalize_comparison, 5772 "On some machines not all possible comparisons are defined, but you can\n\ 5773convert an invalid comparison into a valid one. For example, the Alpha\n\ 5774does not have a @code{GT} comparison, but you can use an @code{LT}\n\ 5775comparison instead and swap the order of the operands.\n\ 5776\n\ 5777On such machines, implement this hook to do any required conversions.\n\ 5778@var{code} is the initial comparison code and @var{op0} and @var{op1}\n\ 5779are the left and right operands of the comparison, respectively. If\n\ 5780@var{op0_preserve_value} is @code{true} the implementation is not\n\ 5781allowed to change the value of @var{op0} since the value might be used\n\ 5782in RTXs which aren't comparisons. E.g. the implementation is not\n\ 5783allowed to swap operands in that case.\n\ 5784\n\ 5785GCC will not assume that the comparison resulting from this macro is\n\ 5786valid but will see if the resulting insn matches a pattern in the\n\ 5787@file{md} file.\n\ 5788\n\ 5789You need not to implement this hook if it would never change the\n\ 5790comparison code or operands.", 5791 void, (int *code, rtx *op0, rtx *op1, bool op0_preserve_value), 5792 default_canonicalize_comparison) 5793 5794DEFHOOKPOD 5795(atomic_test_and_set_trueval, 5796 "This value should be set if the result written by\ 5797 @code{atomic_test_and_set} is not exactly 1, i.e. the\ 5798 @code{bool} @code{true}.", 5799 unsigned char, 1) 5800 5801/* Return an unsigned int representing the alignment (in bits) of the atomic 5802 type which maps to machine MODE. This allows alignment to be overridden 5803 as needed. */ 5804DEFHOOK 5805(atomic_align_for_mode, 5806"If defined, this function returns an appropriate alignment in bits for an\ 5807 atomic object of machine_mode @var{mode}. If 0 is returned then the\ 5808 default alignment for the specified mode is used. ", 5809 unsigned int, (machine_mode mode), 5810 hook_uint_mode_0) 5811 5812DEFHOOK 5813(atomic_assign_expand_fenv, 5814"ISO C11 requires atomic compound assignments that may raise floating-point\ 5815 exceptions to raise exceptions corresponding to the arithmetic operation\ 5816 whose result was successfully stored in a compare-and-exchange sequence. \ 5817 This requires code equivalent to calls to @code{feholdexcept},\ 5818 @code{feclearexcept} and @code{feupdateenv} to be generated at\ 5819 appropriate points in the compare-and-exchange sequence. This hook should\ 5820 set @code{*@var{hold}} to an expression equivalent to the call to\ 5821 @code{feholdexcept}, @code{*@var{clear}} to an expression equivalent to\ 5822 the call to @code{feclearexcept} and @code{*@var{update}} to an expression\ 5823 equivalent to the call to @code{feupdateenv}. The three expressions are\ 5824 @code{NULL_TREE} on entry to the hook and may be left as @code{NULL_TREE}\ 5825 if no code is required in a particular place. The default implementation\ 5826 leaves all three expressions as @code{NULL_TREE}. The\ 5827 @code{__atomic_feraiseexcept} function from @code{libatomic} may be of use\ 5828 as part of the code generated in @code{*@var{update}}.", 5829 void, (tree *hold, tree *clear, tree *update), 5830 default_atomic_assign_expand_fenv) 5831 5832/* Leave the boolean fields at the end. */ 5833 5834/* True if we can create zeroed data by switching to a BSS section 5835 and then using ASM_OUTPUT_SKIP to allocate the space. */ 5836DEFHOOKPOD 5837(have_switchable_bss_sections, 5838 "This flag is true if we can create zeroed data by switching to a BSS\n\ 5839section and then using @code{ASM_OUTPUT_SKIP} to allocate the space.\n\ 5840This is true on most ELF targets.", 5841 bool, false) 5842 5843/* True if "native" constructors and destructors are supported, 5844 false if we're using collect2 for the job. */ 5845DEFHOOKPOD 5846(have_ctors_dtors, 5847 "This value is true if the target supports some ``native'' method of\n\ 5848collecting constructors and destructors to be run at startup and exit.\n\ 5849It is false if we must use @command{collect2}.", 5850 bool, false) 5851 5852/* True if thread-local storage is supported. */ 5853DEFHOOKPOD 5854(have_tls, 5855 "Contains the value true if the target supports thread-local storage.\n\ 5856The default value is false.", 5857 bool, false) 5858 5859/* True if a small readonly data section is supported. */ 5860DEFHOOKPOD 5861(have_srodata_section, 5862 "Contains the value true if the target places read-only\n\ 5863``small data'' into a separate section. The default value is false.", 5864 bool, false) 5865 5866/* True if EH frame info sections should be zero-terminated. */ 5867DEFHOOKPOD 5868(terminate_dw2_eh_frame_info, 5869 "Contains the value true if the target should add a zero word onto the\n\ 5870end of a Dwarf-2 frame info section when used for exception handling.\n\ 5871Default value is false if @code{EH_FRAME_SECTION_NAME} is defined, and\n\ 5872true otherwise.", 5873 bool, true) 5874 5875/* True if #NO_APP should be emitted at the beginning of assembly output. */ 5876DEFHOOKPOD 5877(asm_file_start_app_off, 5878 "If this flag is true, the text of the macro @code{ASM_APP_OFF} will be\n\ 5879printed as the very first line in the assembly file, unless\n\ 5880@option{-fverbose-asm} is in effect. (If that macro has been defined\n\ 5881to the empty string, this variable has no effect.) With the normal\n\ 5882definition of @code{ASM_APP_OFF}, the effect is to notify the GNU\n\ 5883assembler that it need not bother stripping comments or extra\n\ 5884whitespace from its input. This allows it to work a bit faster.\n\ 5885\n\ 5886The default is false. You should not set it to true unless you have\n\ 5887verified that your port does not generate any extra whitespace or\n\ 5888comments that will cause GAS to issue errors in NO_APP mode.", 5889 bool, false) 5890 5891/* True if output_file_directive should be called for main_input_filename 5892 at the beginning of assembly output. */ 5893DEFHOOKPOD 5894(asm_file_start_file_directive, 5895 "If this flag is true, @code{output_file_directive} will be called\n\ 5896for the primary source file, immediately after printing\n\ 5897@code{ASM_APP_OFF} (if that is enabled). Most ELF assemblers expect\n\ 5898this to be done. The default is false.", 5899 bool, false) 5900 5901/* Returns true if we should generate exception tables for use with the 5902 ARM EABI. The effects the encoding of function exception specifications. */ 5903DEFHOOKPOD 5904(arm_eabi_unwinder, 5905 "This flag should be set to @code{true} on targets that use an ARM EABI\n\ 5906based unwinding library, and @code{false} on other targets. This effects\n\ 5907the format of unwinding tables, and how the unwinder in entered after\n\ 5908running a cleanup. The default is @code{false}.", 5909 bool, false) 5910 5911DEFHOOKPOD 5912(want_debug_pub_sections, 5913 "True if the @code{.debug_pubtypes} and @code{.debug_pubnames} sections\ 5914 should be emitted. These sections are not used on most platforms, and\ 5915 in particular GDB does not use them.", 5916 bool, false) 5917 5918DEFHOOKPOD 5919(force_at_comp_dir, 5920 "True if the @code{DW_AT_comp_dir} attribute should be emitted for each \ 5921 compilation unit. This attribute is required for the darwin linker \ 5922 to emit debug information.", 5923 bool, false) 5924 5925DEFHOOKPOD 5926(delay_sched2, "True if sched2 is not to be run at its normal place.\n\ 5927This usually means it will be run as part of machine-specific reorg.", 5928bool, false) 5929 5930DEFHOOKPOD 5931(delay_vartrack, "True if vartrack is not to be run at its normal place.\n\ 5932This usually means it will be run as part of machine-specific reorg.", 5933bool, false) 5934 5935DEFHOOKPOD 5936(no_register_allocation, "True if register allocation and the passes\n\ 5937following it should not be run. Usually true only for virtual assembler\n\ 5938targets.", 5939bool, false) 5940 5941/* Leave the boolean fields at the end. */ 5942 5943/* Functions related to mode switching. */ 5944#undef HOOK_PREFIX 5945#define HOOK_PREFIX "TARGET_MODE_" 5946HOOK_VECTOR (TARGET_TOGGLE_, mode_switching) 5947 5948DEFHOOK 5949(emit, 5950 "Generate one or more insns to set @var{entity} to @var{mode}. @var{hard_reg_live} is the set of hard registers live at the point where the insn(s) are to be inserted. @var{prev_moxde} indicates the mode to switch from. Sets of a lower numbered entity will be emitted before sets of a higher numbered entity to a mode of the same or lower priority.", 5951 void, (int entity, int mode, int prev_mode, HARD_REG_SET regs_live), NULL) 5952 5953DEFHOOK 5954(needed, 5955 "@var{entity} is an integer specifying a mode-switched entity. If @code{OPTIMIZE_MODE_SWITCHING} is defined, you must define this macro to return an integer value not larger than the corresponding element in @code{NUM_MODES_FOR_MODE_SWITCHING}, to denote the mode that @var{entity} must be switched into prior to the execution of @var{insn}.", 5956 int, (int entity, rtx_insn *insn), NULL) 5957 5958DEFHOOK 5959(after, 5960 "@var{entity} is an integer specifying a mode-switched entity. If this macro is defined, it is evaluated for every @var{insn} during mode switching. It determines the mode that an insn results in (if different from the incoming mode).", 5961 int, (int entity, int mode, rtx_insn *insn), NULL) 5962 5963DEFHOOK 5964(entry, 5965 "If this macro is defined, it is evaluated for every @var{entity} that needs mode switching. It should evaluate to an integer, which is a mode that @var{entity} is assumed to be switched to at function entry. If @code{TARGET_MODE_ENTRY} is defined then @code{TARGET_MODE_EXIT} must be defined.", 5966 int, (int entity), NULL) 5967 5968DEFHOOK 5969(exit, 5970 "If this macro is defined, it is evaluated for every @var{entity} that needs mode switching. It should evaluate to an integer, which is a mode that @var{entity} is assumed to be switched to at function exit. If @code{TARGET_MODE_EXIT} is defined then @code{TARGET_MODE_ENTRY} must be defined.", 5971 int, (int entity), NULL) 5972 5973DEFHOOK 5974(priority, 5975 "This macro specifies the order in which modes for @var{entity} are processed. 0 is the highest priority, @code{NUM_MODES_FOR_MODE_SWITCHING[@var{entity}] - 1} the lowest. The value of the macro should be an integer designating a mode for @var{entity}. For any fixed @var{entity}, @code{mode_priority} (@var{entity}, @var{n}) shall be a bijection in 0 @dots{} @code{num_modes_for_mode_switching[@var{entity}] - 1}.", 5976 int, (int entity, int n), NULL) 5977 5978HOOK_VECTOR_END (mode_switching) 5979 5980#undef HOOK_PREFIX 5981#define HOOK_PREFIX "TARGET_" 5982 5983#define DEF_TARGET_INSN(NAME, PROTO) \ 5984 DEFHOOK_UNDOC (have_##NAME, "", bool, (void), false) 5985#include "target-insns.def" 5986#undef DEF_TARGET_INSN 5987 5988#define DEF_TARGET_INSN(NAME, PROTO) \ 5989 DEFHOOK_UNDOC (gen_##NAME, "", rtx_insn *, PROTO, NULL) 5990#include "target-insns.def" 5991#undef DEF_TARGET_INSN 5992 5993#define DEF_TARGET_INSN(NAME, PROTO) \ 5994 DEFHOOKPOD (code_for_##NAME, "*", enum insn_code, CODE_FOR_nothing) 5995#include "target-insns.def" 5996#undef DEF_TARGET_INSN 5997 5998/* Close the 'struct gcc_target' definition. */ 5999HOOK_VECTOR_END (C90_EMPTY_HACK) 6000 6001