1 /* Data structure definitions for a generic GCC target. 2 Copyright (C) 2001, 2002, 2003, 2004, 2005 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 2, 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; if not, write to the Free Software 16 Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. 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 /* This file contains a data structure that describes a GCC target. 23 At present it is incomplete, but in future it should grow to 24 contain most or all target machine and target O/S specific 25 information. 26 27 This structure has its initializer declared in target-def.h in the 28 form of large macro TARGET_INITIALIZER that expands to many smaller 29 macros. 30 31 The smaller macros each initialize one component of the structure, 32 and each has a default. Each target should have a file that 33 includes target.h and target-def.h, and overrides any inappropriate 34 defaults by undefining the relevant macro and defining a suitable 35 replacement. That file should then contain the definition of 36 "targetm" like so: 37 38 struct gcc_target targetm = TARGET_INITIALIZER; 39 40 Doing things this way allows us to bring together everything that 41 defines a GCC target. By supplying a default that is appropriate 42 to most targets, we can easily add new items without needing to 43 edit dozens of target configuration files. It should also allow us 44 to gradually reduce the amount of conditional compilation that is 45 scattered throughout GCC. */ 46 47 #ifndef GCC_TARGET_H 48 #define GCC_TARGET_H 49 50 #include "tm.h" 51 #include "insn-modes.h" 52 53 struct stdarg_info; 54 55 struct gcc_target 56 { 57 /* Functions that output assembler for the target. */ 58 struct asm_out 59 { 60 /* Opening and closing parentheses for asm expression grouping. */ 61 const char *open_paren, *close_paren; 62 63 /* Assembler instructions for creating various kinds of integer object. */ 64 const char *byte_op; 65 struct asm_int_op 66 { 67 const char *hi; 68 const char *si; 69 const char *di; 70 const char *ti; 71 } aligned_op, unaligned_op; 72 73 /* Try to output the assembler code for an integer object whose 74 value is given by X. SIZE is the size of the object in bytes and 75 ALIGNED_P indicates whether it is aligned. Return true if 76 successful. Only handles cases for which BYTE_OP, ALIGNED_OP 77 and UNALIGNED_OP are NULL. */ 78 bool (* integer) (rtx x, unsigned int size, int aligned_p); 79 80 /* Output code that will globalize a label. */ 81 void (* globalize_label) (FILE *, const char *); 82 83 /* Output code that will emit a label for unwind info, if this 84 target requires such labels. Second argument is the decl the 85 unwind info is associated with, third is a boolean: true if 86 this is for exception handling, fourth is a boolean: true if 87 this is only a placeholder for an omitted FDE. */ 88 void (* unwind_label) (FILE *, tree, int, int); 89 90 /* Emit any directives required to unwind this instruction. */ 91 void (* unwind_emit) (FILE *, rtx); 92 93 /* Output an internal label. */ 94 void (* internal_label) (FILE *, const char *, unsigned long); 95 96 /* Emit a ttype table reference to a typeinfo object. */ 97 bool (* ttype) (rtx); 98 99 /* Emit an assembler directive to set visibility for the symbol 100 associated with the tree decl. */ 101 void (* visibility) (tree, int); 102 103 /* Output the assembler code for entry to a function. */ 104 void (* function_prologue) (FILE *, HOST_WIDE_INT); 105 106 /* Output the assembler code for end of prologue. */ 107 void (* function_end_prologue) (FILE *); 108 109 /* Output the assembler code for start of epilogue. */ 110 void (* function_begin_epilogue) (FILE *); 111 112 /* Output the assembler code for function exit. */ 113 void (* function_epilogue) (FILE *, HOST_WIDE_INT); 114 115 /* Tell assembler to change to section NAME with attributes FLAGS. 116 If DECL is non-NULL, it is the VAR_DECL or FUNCTION_DECL with 117 which this section is associated. */ 118 void (* named_section) (const char *name, unsigned int flags, tree decl); 119 120 /* Switch to the section that holds the exception table. */ 121 void (* exception_section) (void); 122 123 /* Switch to the section that holds the exception frames. */ 124 void (* eh_frame_section) (void); 125 126 /* Select and switch to a section for EXP. It may be a DECL or a 127 constant. RELOC is nonzero if runtime relocations must be applied; 128 bit 1 will be set if the runtime relocations require non-local 129 name resolution. ALIGN is the required alignment of the data. */ 130 void (* select_section) (tree, int, unsigned HOST_WIDE_INT); 131 132 /* Select and switch to a section for X with MODE. ALIGN is 133 the desired alignment of the data. */ 134 void (* select_rtx_section) (enum machine_mode, rtx, 135 unsigned HOST_WIDE_INT); 136 137 /* Select a unique section name for DECL. RELOC is the same as 138 for SELECT_SECTION. */ 139 void (* unique_section) (tree, int); 140 141 /* Tell assembler to switch to the readonly data section associated 142 with function DECL. */ 143 void (* function_rodata_section) (tree); 144 145 /* Output a constructor for a symbol with a given priority. */ 146 void (* constructor) (rtx, int); 147 148 /* Output a destructor for a symbol with a given priority. */ 149 void (* destructor) (rtx, int); 150 151 /* Output the assembler code for a thunk function. THUNK_DECL is the 152 declaration for the thunk function itself, FUNCTION is the decl for 153 the target function. DELTA is an immediate constant offset to be 154 added to THIS. If VCALL_OFFSET is nonzero, the word at 155 *(*this + vcall_offset) should be added to THIS. */ 156 void (* output_mi_thunk) (FILE *file, tree thunk_decl, 157 HOST_WIDE_INT delta, HOST_WIDE_INT vcall_offset, 158 tree function_decl); 159 160 /* Determine whether output_mi_thunk would succeed. */ 161 /* ??? Ideally, this hook would not exist, and success or failure 162 would be returned from output_mi_thunk directly. But there's 163 too much undo-able setup involved in invoking output_mi_thunk. 164 Could be fixed by making output_mi_thunk emit rtl instead of 165 text to the output file. */ 166 bool (* can_output_mi_thunk) (tree thunk_decl, HOST_WIDE_INT delta, 167 HOST_WIDE_INT vcall_offset, 168 tree function_decl); 169 170 /* Output any boilerplate text needed at the beginning of a 171 translation unit. */ 172 void (*file_start) (void); 173 174 /* Output any boilerplate text needed at the end of a 175 translation unit. */ 176 void (*file_end) (void); 177 178 /* Output an assembler pseudo-op to declare a library function name 179 external. */ 180 void (*external_libcall) (rtx); 181 182 /* Output an assembler directive to mark decl live. This instructs 183 linker to not dead code strip this symbol. */ 184 void (*mark_decl_preserved) (const char *); 185 186 /* Output a DTP-relative reference to a TLS symbol. */ 187 void (*output_dwarf_dtprel) (FILE *file, int size, rtx x); 188 189 } asm_out; 190 191 /* Functions relating to instruction scheduling. */ 192 struct sched 193 { 194 /* Given the current cost, COST, of an insn, INSN, calculate and 195 return a new cost based on its relationship to DEP_INSN through 196 the dependence LINK. The default is to make no adjustment. */ 197 int (* adjust_cost) (rtx insn, rtx link, rtx def_insn, int cost); 198 199 /* Adjust the priority of an insn as you see fit. Returns the new 200 priority. */ 201 int (* adjust_priority) (rtx, int); 202 203 /* Function which returns the maximum number of insns that can be 204 scheduled in the same machine cycle. This must be constant 205 over an entire compilation. The default is 1. */ 206 int (* issue_rate) (void); 207 208 /* Calculate how much this insn affects how many more insns we 209 can emit this cycle. Default is they all cost the same. */ 210 int (* variable_issue) (FILE *, int, rtx, int); 211 212 /* Initialize machine-dependent scheduling code. */ 213 void (* md_init) (FILE *, int, int); 214 215 /* Finalize machine-dependent scheduling code. */ 216 void (* md_finish) (FILE *, int); 217 218 /* Initialize machine-dependent function while scheduling code. */ 219 void (* md_init_global) (FILE *, int, int); 220 221 /* Finalize machine-dependent function wide scheduling code. */ 222 void (* md_finish_global) (FILE *, int); 223 224 /* Reorder insns in a machine-dependent fashion, in two different 225 places. Default does nothing. */ 226 int (* reorder) (FILE *, int, rtx *, int *, int); 227 int (* reorder2) (FILE *, int, rtx *, int *, int); 228 229 /* The following member value is a pointer to a function called 230 after evaluation forward dependencies of insns in chain given 231 by two parameter values (head and tail correspondingly). */ 232 void (* dependencies_evaluation_hook) (rtx, rtx); 233 234 /* The values of the following four members are pointers to 235 functions used to simplify the automaton descriptions. 236 dfa_pre_cycle_insn and dfa_post_cycle_insn give functions 237 returning insns which are used to change the pipeline hazard 238 recognizer state when the new simulated processor cycle 239 correspondingly starts and finishes. The function defined by 240 init_dfa_pre_cycle_insn and init_dfa_post_cycle_insn are used 241 to initialize the corresponding insns. The default values of 242 the members result in not changing the automaton state when 243 the new simulated processor cycle correspondingly starts and 244 finishes. */ 245 void (* init_dfa_pre_cycle_insn) (void); 246 rtx (* dfa_pre_cycle_insn) (void); 247 void (* init_dfa_post_cycle_insn) (void); 248 rtx (* dfa_post_cycle_insn) (void); 249 250 /* The following member value is a pointer to a function returning value 251 which defines how many insns in queue `ready' will we try for 252 multi-pass scheduling. If the member value is nonzero and the 253 function returns positive value, the DFA based scheduler will make 254 multi-pass scheduling for the first cycle. In other words, we will 255 try to choose ready insn which permits to start maximum number of 256 insns on the same cycle. */ 257 int (* first_cycle_multipass_dfa_lookahead) (void); 258 259 /* The following member value is pointer to a function controlling 260 what insns from the ready insn queue will be considered for the 261 multipass insn scheduling. If the hook returns zero for insn 262 passed as the parameter, the insn will be not chosen to be 263 issued. */ 264 int (* first_cycle_multipass_dfa_lookahead_guard) (rtx); 265 266 /* The following member value is pointer to a function called by 267 the insn scheduler before issuing insn passed as the third 268 parameter on given cycle. If the hook returns nonzero, the 269 insn is not issued on given processors cycle. Instead of that, 270 the processor cycle is advanced. If the value passed through 271 the last parameter is zero, the insn ready queue is not sorted 272 on the new cycle start as usually. The first parameter passes 273 file for debugging output. The second one passes the scheduler 274 verbose level of the debugging output. The forth and the fifth 275 parameter values are correspondingly processor cycle on which 276 the previous insn has been issued and the current processor 277 cycle. */ 278 int (* dfa_new_cycle) (FILE *, int, rtx, int, int, int *); 279 280 /* The following member value is a pointer to a function called 281 by the insn scheduler. It should return true if there exists a 282 dependence which is considered costly by the target, between 283 the insn passed as the first parameter, and the insn passed as 284 the second parameter. The third parameter is the INSN_DEPEND 285 link that represents the dependence between the two insns. The 286 fourth argument is the cost of the dependence as estimated by 287 the scheduler. The last argument is the distance in cycles 288 between the already scheduled insn (first parameter) and the 289 the second insn (second parameter). */ 290 bool (* is_costly_dependence) (rtx, rtx, rtx, int, int); 291 } sched; 292 293 /* Functions relating to vectorization. */ 294 struct vectorize 295 { 296 /* The following member value is a pointer to a function called 297 by the vectorizer, and return the decl of the target builtin 298 function. */ 299 tree (* builtin_mask_for_load) (void); 300 } vectorize; 301 302 /* The initial value of target_flags. */ 303 int default_target_flags; 304 305 /* Handle target switch CODE (an OPT_* value). ARG is the argument 306 passed to the switch; it is NULL if no argument was. VALUE is the 307 value of ARG if CODE specifies a UInteger option, otherwise it is 308 1 if the positive form of the switch was used and 0 if the negative 309 form was. Return true if the switch was valid. */ 310 bool (* handle_option) (size_t code, const char *arg, int value); 311 312 /* Return machine mode for filter value. */ 313 enum machine_mode (* eh_return_filter_mode) (void); 314 315 /* Given two decls, merge their attributes and return the result. */ 316 tree (* merge_decl_attributes) (tree, tree); 317 318 /* Given two types, merge their attributes and return the result. */ 319 tree (* merge_type_attributes) (tree, tree); 320 321 /* Table of machine attributes and functions to handle them. 322 Ignored if NULL. */ 323 const struct attribute_spec *attribute_table; 324 325 /* Return zero if the attributes on TYPE1 and TYPE2 are incompatible, 326 one if they are compatible and two if they are nearly compatible 327 (which causes a warning to be generated). */ 328 int (* comp_type_attributes) (tree type1, tree type2); 329 330 /* Assign default attributes to the newly defined TYPE. */ 331 void (* set_default_type_attributes) (tree type); 332 333 /* Insert attributes on the newly created DECL. */ 334 void (* insert_attributes) (tree decl, tree *attributes); 335 336 /* Return true if FNDECL (which has at least one machine attribute) 337 can be inlined despite its machine attributes, false otherwise. */ 338 bool (* function_attribute_inlinable_p) (tree fndecl); 339 340 /* Return true if bitfields in RECORD_TYPE should follow the 341 Microsoft Visual C++ bitfield layout rules. */ 342 bool (* ms_bitfield_layout_p) (tree record_type); 343 344 /* Return true if anonymous bitfields affect structure alignment. */ 345 bool (* align_anon_bitfield) (void); 346 347 /* Set up target-specific built-in functions. */ 348 void (* init_builtins) (void); 349 350 /* Expand a target-specific builtin. */ 351 rtx (* expand_builtin) (tree exp, rtx target, rtx subtarget, 352 enum machine_mode mode, int ignore); 353 354 /* Select a replacement for a target-specific builtin. This is done 355 *before* regular type checking, and so allows the target to implement 356 a crude form of function overloading. The result is a complete 357 expression that implements the operation. */ 358 tree (*resolve_overloaded_builtin) (tree decl, tree params); 359 360 /* Fold a target-specific builtin. */ 361 tree (* fold_builtin) (tree fndecl, tree arglist, bool ignore); 362 363 /* For a vendor-specific fundamental TYPE, return a pointer to 364 a statically-allocated string containing the C++ mangling for 365 TYPE. In all other cases, return NULL. */ 366 const char * (* mangle_fundamental_type) (tree type); 367 368 /* Make any adjustments to libfunc names needed for this target. */ 369 void (* init_libfuncs) (void); 370 371 /* Given a decl, a section name, and whether the decl initializer 372 has relocs, choose attributes for the section. */ 373 /* ??? Should be merged with SELECT_SECTION and UNIQUE_SECTION. */ 374 unsigned int (* section_type_flags) (tree, const char *, int); 375 376 /* True if new jumps cannot be created, to replace existing ones or 377 not, at the current point in the compilation. */ 378 bool (* cannot_modify_jumps_p) (void); 379 380 /* Return a register class for which branch target register 381 optimizations should be applied. */ 382 int (* branch_target_register_class) (void); 383 384 /* Return true if branch target register optimizations should include 385 callee-saved registers that are not already live during the current 386 function. AFTER_PE_GEN is true if prologues and epilogues have 387 already been generated. */ 388 bool (* branch_target_register_callee_saved) (bool after_pe_gen); 389 390 /* True if the constant X cannot be placed in the constant pool. */ 391 bool (* cannot_force_const_mem) (rtx); 392 393 /* True if the insn X cannot be duplicated. */ 394 bool (* cannot_copy_insn_p) (rtx); 395 396 /* True if X is considered to be commutative. */ 397 bool (* commutative_p) (rtx, int); 398 399 /* Given an address RTX, undo the effects of LEGITIMIZE_ADDRESS. */ 400 rtx (* delegitimize_address) (rtx); 401 402 /* True if it is OK to do sibling call optimization for the specified 403 call expression EXP. DECL will be the called function, or NULL if 404 this is an indirect call. */ 405 bool (*function_ok_for_sibcall) (tree decl, tree exp); 406 407 /* True if EXP should be placed in a "small data" section. */ 408 bool (* in_small_data_p) (tree); 409 410 /* True if EXP names an object for which name resolution must resolve 411 to the current module. */ 412 bool (* binds_local_p) (tree); 413 414 /* Do something target-specific to record properties of the DECL into 415 the associated SYMBOL_REF. */ 416 void (* encode_section_info) (tree, rtx, int); 417 418 /* Undo the effects of encode_section_info on the symbol string. */ 419 const char * (* strip_name_encoding) (const char *); 420 421 /* If shift optabs for MODE are known to always truncate the shift count, 422 return the mask that they apply. Return 0 otherwise. */ 423 unsigned HOST_WIDE_INT (* shift_truncation_mask) (enum machine_mode mode); 424 425 /* Return the number of divisions in the given MODE that should be present, 426 so that it is profitable to turn the division into a multiplication by 427 the reciprocal. */ 428 unsigned int (* min_divisions_for_recip_mul) (enum machine_mode mode); 429 430 /* True if MODE is valid for a pointer in __attribute__((mode("MODE"))). */ 431 bool (* valid_pointer_mode) (enum machine_mode mode); 432 433 /* True if MODE is valid for the target. By "valid", we mean able to 434 be manipulated in non-trivial ways. In particular, this means all 435 the arithmetic is supported. */ 436 bool (* scalar_mode_supported_p) (enum machine_mode mode); 437 438 /* Similarly for vector modes. "Supported" here is less strict. At 439 least some operations are supported; need to check optabs or builtins 440 for further details. */ 441 bool (* vector_mode_supported_p) (enum machine_mode mode); 442 443 /* True if a vector is opaque. */ 444 bool (* vector_opaque_p) (tree); 445 446 /* Compute a (partial) cost for rtx X. Return true if the complete 447 cost has been computed, and false if subexpressions should be 448 scanned. In either case, *TOTAL contains the cost result. */ 449 /* Note that CODE and OUTER_CODE ought to be RTX_CODE, but that's 450 not necessarily defined at this point. */ 451 bool (* rtx_costs) (rtx x, int code, int outer_code, int *total); 452 453 /* Compute the cost of X, used as an address. Never called with 454 invalid addresses. */ 455 int (* address_cost) (rtx x); 456 457 /* Return where to allocate pseudo for a given hard register initial 458 value. */ 459 rtx (* allocate_initial_value) (rtx x); 460 461 /* Given a register, this hook should return a parallel of registers 462 to represent where to find the register pieces. Define this hook 463 if the register and its mode are represented in Dwarf in 464 non-contiguous locations, or if the register should be 465 represented in more than one register in Dwarf. Otherwise, this 466 hook should return NULL_RTX. */ 467 rtx (* dwarf_register_span) (rtx); 468 469 /* Fetch the fixed register(s) which hold condition codes, for 470 targets where it makes sense to look for duplicate assignments to 471 the condition codes. This should return true if there is such a 472 register, false otherwise. The arguments should be set to the 473 fixed register numbers. Up to two condition code registers are 474 supported. If there is only one for this target, the int pointed 475 at by the second argument should be set to -1. */ 476 bool (* fixed_condition_code_regs) (unsigned int *, unsigned int *); 477 478 /* If two condition code modes are compatible, return a condition 479 code mode which is compatible with both, such that a comparison 480 done in the returned mode will work for both of the original 481 modes. If the condition code modes are not compatible, return 482 VOIDmode. */ 483 enum machine_mode (* cc_modes_compatible) (enum machine_mode, 484 enum machine_mode); 485 486 /* Do machine-dependent code transformations. Called just before 487 delayed-branch scheduling. */ 488 void (* machine_dependent_reorg) (void); 489 490 /* Create the __builtin_va_list type. */ 491 tree (* build_builtin_va_list) (void); 492 493 /* Gimplifies a VA_ARG_EXPR. */ 494 tree (* gimplify_va_arg_expr) (tree valist, tree type, tree *pre_p, 495 tree *post_p); 496 497 /* Validity-checking routines for PCH files, target-specific. 498 get_pch_validity returns a pointer to the data to be stored, 499 and stores the size in its argument. pch_valid_p gets the same 500 information back and returns NULL if the PCH is valid, 501 or an error message if not. 502 */ 503 void * (* get_pch_validity) (size_t *); 504 const char * (* pch_valid_p) (const void *, size_t); 505 506 /* If nonnull, this function checks whether a PCH file with the 507 given set of target flags can be used. It returns NULL if so, 508 otherwise it returns an error message. */ 509 const char *(*check_pch_target_flags) (int); 510 511 /* True if the compiler should give an enum type only as many 512 bytes as it takes to represent the range of possible values of 513 that type. */ 514 bool (* default_short_enums) (void); 515 516 /* This target hook returns an rtx that is used to store the address 517 of the current frame into the built-in setjmp buffer. */ 518 rtx (* builtin_setjmp_frame_value) (void); 519 520 /* This target hook should add STRING_CST trees for any hard regs 521 the port wishes to automatically clobber for an asm. */ 522 tree (* md_asm_clobbers) (tree, tree, tree); 523 524 /* This target hook allows the backend to specify a calling convention 525 in the debug information. This function actually returns an 526 enum dwarf_calling_convention, but because of forward declarations 527 and not wanting to include dwarf2.h everywhere target.h is included 528 the function is being declared as an int. */ 529 int (* dwarf_calling_convention) (tree); 530 531 /* This target hook allows the backend to emit frame-related insns that 532 contain UNSPECs or UNSPEC_VOLATILEs. The call frame debugging info 533 engine will invoke it on insns of the form 534 (set (reg) (unspec [...] UNSPEC_INDEX)) 535 and 536 (set (reg) (unspec_volatile [...] UNSPECV_INDEX)) 537 to let the backend emit the call frame instructions. */ 538 void (* dwarf_handle_frame_unspec) (const char *, rtx, int); 539 540 /* Perform architecture specific checking of statements gimplified 541 from VA_ARG_EXPR. LHS is left hand side of MODIFY_EXPR, RHS 542 is right hand side. Returns true if the statements doesn't need 543 to be checked for va_list references. */ 544 bool (* stdarg_optimize_hook) (struct stdarg_info *ai, tree lhs, tree rhs); 545 546 /* This target hook allows the operating system to override the DECL 547 that represents the external variable that contains the stack 548 protection guard variable. The type of this DECL is ptr_type_node. */ 549 tree (* stack_protect_guard) (void); 550 551 /* This target hook allows the operating system to override the CALL_EXPR 552 that is invoked when a check vs the guard variable fails. */ 553 tree (* stack_protect_fail) (void); 554 555 /* Returns NULL if target supports the insn within a doloop block, 556 otherwise it returns an error message. */ 557 const char * (*invalid_within_doloop) (rtx); 558 559 /* DECL is a variable or function with __attribute__((dllimport)) 560 specified. Use this hook if the target needs to add extra validation 561 checks to handle_dll_attribute (). */ 562 bool (* valid_dllimport_attribute_p) (tree decl); 563 564 /* Functions relating to calls - argument passing, returns, etc. */ 565 struct calls { 566 bool (*promote_function_args) (tree fntype); 567 bool (*promote_function_return) (tree fntype); 568 bool (*promote_prototypes) (tree fntype); 569 rtx (*struct_value_rtx) (tree fndecl, int incoming); 570 bool (*return_in_memory) (tree type, tree fndecl); 571 bool (*return_in_msb) (tree type); 572 573 /* Return true if a parameter must be passed by reference. TYPE may 574 be null if this is a libcall. CA may be null if this query is 575 from __builtin_va_arg. */ 576 bool (*pass_by_reference) (CUMULATIVE_ARGS *ca, enum machine_mode mode, 577 tree type, bool named_arg); 578 579 rtx (*expand_builtin_saveregs) (void); 580 /* Returns pretend_argument_size. */ 581 void (*setup_incoming_varargs) (CUMULATIVE_ARGS *ca, enum machine_mode mode, 582 tree type, int *pretend_arg_size, 583 int second_time); 584 bool (*strict_argument_naming) (CUMULATIVE_ARGS *ca); 585 /* Returns true if we should use 586 targetm.calls.setup_incoming_varargs() and/or 587 targetm.calls.strict_argument_naming(). */ 588 bool (*pretend_outgoing_varargs_named) (CUMULATIVE_ARGS *ca); 589 590 /* Given a complex type T, return true if a parameter of type T 591 should be passed as two scalars. */ 592 bool (* split_complex_arg) (tree type); 593 594 /* Return true if type T, mode MODE, may not be passed in registers, 595 but must be passed on the stack. */ 596 /* ??? This predicate should be applied strictly after pass-by-reference. 597 Need audit to verify that this is the case. */ 598 bool (* must_pass_in_stack) (enum machine_mode mode, tree t); 599 600 /* Return true if type TYPE, mode MODE, which is passed by reference, 601 should have the object copy generated by the callee rather than 602 the caller. It is never called for TYPE requiring constructors. */ 603 bool (* callee_copies) (CUMULATIVE_ARGS *ca, enum machine_mode mode, 604 tree type, bool named); 605 606 /* Return zero for arguments passed entirely on the stack or entirely 607 in registers. If passed in both, return the number of bytes passed 608 in registers; the balance is therefore passed on the stack. */ 609 int (* arg_partial_bytes) (CUMULATIVE_ARGS *ca, enum machine_mode mode, 610 tree type, bool named); 611 612 /* Return the diagnostic message string if function without a prototype 613 is not allowed for this 'val' argument; NULL otherwise. */ 614 const char *(*invalid_arg_for_unprototyped_fn) (tree typelist, 615 tree funcdecl, tree val); 616 617 /* Return an rtx for the return value location of the function 618 specified by FN_DECL_OR_TYPE with a return type of RET_TYPE. */ 619 rtx (*function_value) (tree ret_type, tree fn_decl_or_type, 620 bool outgoing); 621 622 /* Return an rtx for the argument pointer incoming to the 623 current function. */ 624 rtx (*internal_arg_pointer) (void); 625 } calls; 626 627 /* Return the diagnostic message string if conversion from FROMTYPE 628 to TOTYPE is not allowed, NULL otherwise. */ 629 const char *(*invalid_conversion) (tree fromtype, tree totype); 630 631 /* Return the diagnostic message string if the unary operation OP is 632 not permitted on TYPE, NULL otherwise. */ 633 const char *(*invalid_unary_op) (int op, tree type); 634 635 /* Return the diagnostic message string if the binary operation OP 636 is not permitted on TYPE1 and TYPE2, NULL otherwise. */ 637 const char *(*invalid_binary_op) (int op, tree type1, tree type2); 638 639 /* Functions specific to the C++ frontend. */ 640 struct cxx { 641 /* Return the integer type used for guard variables. */ 642 tree (*guard_type) (void); 643 /* Return true if only the low bit of the guard should be tested. */ 644 bool (*guard_mask_bit) (void); 645 /* Returns the size of the array cookie for an array of type. */ 646 tree (*get_cookie_size) (tree); 647 /* Returns true if the element size should be stored in the 648 array cookie. */ 649 bool (*cookie_has_size) (void); 650 /* Allows backends to perform additional processing when 651 deciding if a class should be exported or imported. */ 652 int (*import_export_class) (tree, int); 653 /* Returns true if constructors and destructors return "this". */ 654 bool (*cdtor_returns_this) (void); 655 /* Returns true if the key method for a class can be an inline 656 function, so long as it is not declared inline in the class 657 itself. Returning true is the behavior required by the Itanium 658 C++ ABI. */ 659 bool (*key_method_may_be_inline) (void); 660 /* DECL is a virtual table, virtual table table, typeinfo object, 661 or other similar implicit class data object that will be 662 emitted with external linkage in this translation unit. No ELF 663 visibility has been explicitly specified. If the target needs 664 to specify a visibility other than that of the containing class, 665 use this hook to set DECL_VISIBILITY and 666 DECL_VISIBILITY_SPECIFIED. */ 667 void (*determine_class_data_visibility) (tree decl); 668 /* Returns true (the default) if virtual tables and other 669 similar implicit class data objects are always COMDAT if they 670 have external linkage. If this hook returns false, then 671 class data for classes whose virtual table will be emitted in 672 only one translation unit will not be COMDAT. */ 673 bool (*class_data_always_comdat) (void); 674 /* Returns true if __aeabi_atexit should be used to register static 675 destructors. */ 676 bool (*use_aeabi_atexit) (void); 677 /* TYPE is a C++ class (i.e., RECORD_TYPE or UNION_TYPE) that 678 has just been defined. Use this hook to make adjustments to the 679 class (eg, tweak visibility or perform any other required 680 target modifications). */ 681 void (*adjust_class_at_definition) (tree type); 682 } cxx; 683 684 /* True if unwinding tables should be generated by default. */ 685 bool unwind_tables_default; 686 687 /* Leave the boolean fields at the end. */ 688 689 /* True if arbitrary sections are supported. */ 690 bool have_named_sections; 691 692 /* True if "native" constructors and destructors are supported, 693 false if we're using collect2 for the job. */ 694 bool have_ctors_dtors; 695 696 /* True if thread-local storage is supported. */ 697 bool have_tls; 698 699 /* True if a small readonly data section is supported. */ 700 bool have_srodata_section; 701 702 /* True if EH frame info sections should be zero-terminated. */ 703 bool terminate_dw2_eh_frame_info; 704 705 /* True if #NO_APP should be emitted at the beginning of 706 assembly output. */ 707 bool file_start_app_off; 708 709 /* True if output_file_directive should be called for main_input_filename 710 at the beginning of assembly output. */ 711 bool file_start_file_directive; 712 713 /* True if #pragma redefine_extname is to be supported. */ 714 bool handle_pragma_redefine_extname; 715 716 /* True if #pragma extern_prefix is to be supported. */ 717 bool handle_pragma_extern_prefix; 718 719 /* True if the target is allowed to reorder memory accesses unless 720 synchronization is explicitly requested. */ 721 bool relaxed_ordering; 722 723 /* Returns true if we should generate exception tables for use with the 724 ARM EABI. The effects the encoding of function exception specifications. 725 */ 726 bool arm_eabi_unwinder; 727 728 /* Leave the boolean fields at the end. */ 729 }; 730 731 extern struct gcc_target targetm; 732 733 #endif /* GCC_TARGET_H */ 734