1 /* Definition of RISC-V target for GNU compiler.
2    Copyright (C) 2011-2020 Free Software Foundation, Inc.
3    Contributed by Andrew Waterman (andrew@sifive.com).
4    Based on MIPS target for GNU compiler.
5 
6 This file is part of GCC.
7 
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
11 any later version.
12 
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 GNU General Public License for more details.
17 
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3.  If not see
20 <http://www.gnu.org/licenses/>.  */
21 
22 #ifndef GCC_RISCV_H
23 #define GCC_RISCV_H
24 
25 #include "config/riscv/riscv-opts.h"
26 
27 /* Target CPU builtins.  */
28 #define TARGET_CPU_CPP_BUILTINS() riscv_cpu_cpp_builtins (pfile)
29 
30 /* Target CPU versions for D.  */
31 #define TARGET_D_CPU_VERSIONS riscv_d_target_versions
32 
33 /* Default target_flags if no switches are specified  */
34 
35 #ifndef TARGET_DEFAULT
36 #define TARGET_DEFAULT 0
37 #endif
38 
39 #ifndef RISCV_TUNE_STRING_DEFAULT
40 #define RISCV_TUNE_STRING_DEFAULT "rocket"
41 #endif
42 
43 /* Support for a compile-time default CPU, et cetera.  The rules are:
44    --with-arch is ignored if -march is specified.
45    --with-abi is ignored if -mabi is specified.
46    --with-tune is ignored if -mtune is specified.  */
47 #define OPTION_DEFAULT_SPECS \
48   {"tune", "%{!mtune=*:-mtune=%(VALUE)}" }, \
49   {"arch", "%{!march=*:-march=%(VALUE)}" }, \
50   {"abi", "%{!mabi=*:-mabi=%(VALUE)}" }, \
51 
52 #ifdef IN_LIBGCC2
53 #undef TARGET_64BIT
54 /* Make this compile time constant for libgcc2 */
55 #define TARGET_64BIT           (__riscv_xlen == 64)
56 #endif /* IN_LIBGCC2 */
57 
58 #undef ASM_SPEC
59 #define ASM_SPEC "\
60 %(subtarget_asm_debugging_spec) \
61 %{" FPIE_OR_FPIC_SPEC ":-fpic} \
62 %{march=*} \
63 %{mabi=*} \
64 %(subtarget_asm_spec)"
65 
66 #define TARGET_DEFAULT_CMODEL CM_MEDLOW
67 
68 #define LOCAL_LABEL_PREFIX	"."
69 #define USER_LABEL_PREFIX	""
70 
71 /* Offsets recorded in opcodes are a multiple of this alignment factor.
72    The default for this in 64-bit mode is 8, which causes problems with
73    SFmode register saves.  */
74 #define DWARF_CIE_DATA_ALIGNMENT -4
75 
76 /* The mapping from gcc register number to DWARF 2 CFA column number.  */
77 #define DWARF_FRAME_REGNUM(REGNO) \
78   (GP_REG_P (REGNO) || FP_REG_P (REGNO) ? REGNO : INVALID_REGNUM)
79 
80 /* The DWARF 2 CFA column which tracks the return address.  */
81 #define DWARF_FRAME_RETURN_COLUMN RETURN_ADDR_REGNUM
82 #define INCOMING_RETURN_ADDR_RTX gen_rtx_REG (VOIDmode, RETURN_ADDR_REGNUM)
83 
84 /* Describe how we implement __builtin_eh_return.  */
85 #define EH_RETURN_DATA_REGNO(N) \
86   ((N) < 4 ? (N) + GP_ARG_FIRST : INVALID_REGNUM)
87 
88 #define EH_RETURN_STACKADJ_RTX  gen_rtx_REG (Pmode, GP_ARG_FIRST + 4)
89 
90 /* Target machine storage layout */
91 
92 #define BITS_BIG_ENDIAN 0
93 #define BYTES_BIG_ENDIAN 0
94 #define WORDS_BIG_ENDIAN 0
95 
96 #define MAX_BITS_PER_WORD 64
97 
98 /* Width of a word, in units (bytes).  */
99 #define UNITS_PER_WORD (TARGET_64BIT ? 8 : 4)
100 #ifndef IN_LIBGCC2
101 #define MIN_UNITS_PER_WORD 4
102 #endif
103 
104 /* The `Q' extension is not yet supported.  */
105 #define UNITS_PER_FP_REG (TARGET_DOUBLE_FLOAT ? 8 : 4)
106 
107 /* The largest type that can be passed in floating-point registers.  */
108 #define UNITS_PER_FP_ARG						\
109   ((riscv_abi == ABI_ILP32 || riscv_abi == ABI_ILP32E			\
110     || riscv_abi == ABI_LP64)						\
111    ? 0 									\
112    : ((riscv_abi == ABI_ILP32F || riscv_abi == ABI_LP64F) ? 4 : 8))
113 
114 /* Set the sizes of the core types.  */
115 #define SHORT_TYPE_SIZE 16
116 #define INT_TYPE_SIZE 32
117 #define LONG_LONG_TYPE_SIZE 64
118 #define POINTER_SIZE (riscv_abi >= ABI_LP64 ? 64 : 32)
119 #define LONG_TYPE_SIZE POINTER_SIZE
120 
121 #define FLOAT_TYPE_SIZE 32
122 #define DOUBLE_TYPE_SIZE 64
123 #define LONG_DOUBLE_TYPE_SIZE 128
124 
125 /* Allocation boundary (in *bits*) for storing arguments in argument list.  */
126 #define PARM_BOUNDARY BITS_PER_WORD
127 
128 /* Allocation boundary (in *bits*) for the code of a function.  */
129 #define FUNCTION_BOUNDARY (TARGET_RVC ? 16 : 32)
130 
131 /* The smallest supported stack boundary the calling convention supports.  */
132 #define STACK_BOUNDARY \
133   (riscv_abi == ABI_ILP32E ? BITS_PER_WORD : 2 * BITS_PER_WORD)
134 
135 /* The ABI stack alignment.  */
136 #define ABI_STACK_BOUNDARY (riscv_abi == ABI_ILP32E ? BITS_PER_WORD : 128)
137 
138 /* There is no point aligning anything to a rounder boundary than this.  */
139 #define BIGGEST_ALIGNMENT 128
140 
141 /* The user-level ISA permits unaligned accesses, but they are not required
142    of the privileged architecture.  */
143 #define STRICT_ALIGNMENT TARGET_STRICT_ALIGN
144 
145 /* Define this if you wish to imitate the way many other C compilers
146    handle alignment of bitfields and the structures that contain
147    them.
148 
149    The behavior is that the type written for a bit-field (`int',
150    `short', or other integer type) imposes an alignment for the
151    entire structure, as if the structure really did contain an
152    ordinary field of that type.  In addition, the bit-field is placed
153    within the structure so that it would fit within such a field,
154    not crossing a boundary for it.
155 
156    Thus, on most machines, a bit-field whose type is written as `int'
157    would not cross a four-byte boundary, and would force four-byte
158    alignment for the whole structure.  (The alignment used may not
159    be four bytes; it is controlled by the other alignment
160    parameters.)
161 
162    If the macro is defined, its definition should be a C expression;
163    a nonzero value for the expression enables this behavior.  */
164 
165 #define PCC_BITFIELD_TYPE_MATTERS 1
166 
167 /* An integer expression for the size in bits of the largest integer machine
168    mode that should actually be used.  We allow pairs of registers.  */
169 #define MAX_FIXED_MODE_SIZE GET_MODE_BITSIZE (TARGET_64BIT ? TImode : DImode)
170 
171 /* DATA_ALIGNMENT and LOCAL_ALIGNMENT common definition.  */
172 #define RISCV_EXPAND_ALIGNMENT(COND, TYPE, ALIGN)			\
173   (((COND) && ((ALIGN) < BITS_PER_WORD)					\
174     && (TREE_CODE (TYPE) == ARRAY_TYPE					\
175 	|| TREE_CODE (TYPE) == UNION_TYPE				\
176 	|| TREE_CODE (TYPE) == RECORD_TYPE)) ? BITS_PER_WORD : (ALIGN))
177 
178 /* If defined, a C expression to compute the alignment for a static
179    variable.  TYPE is the data type, and ALIGN is the alignment that
180    the object would ordinarily have.  The value of this macro is used
181    instead of that alignment to align the object.
182 
183    If this macro is not defined, then ALIGN is used.
184 
185    One use of this macro is to increase alignment of medium-size
186    data to make it all fit in fewer cache lines.  Another is to
187    cause character arrays to be word-aligned so that `strcpy' calls
188    that copy constants to character arrays can be done inline.  */
189 
190 #define DATA_ALIGNMENT(TYPE, ALIGN)						\
191   RISCV_EXPAND_ALIGNMENT (riscv_align_data_type == riscv_align_data_type_xlen,	\
192 			  TYPE, ALIGN)
193 
194 /* We need this for the same reason as DATA_ALIGNMENT, namely to cause
195    character arrays to be word-aligned so that `strcpy' calls that copy
196    constants to character arrays can be done inline, and 'strcmp' can be
197    optimised to use word loads. */
198 #define LOCAL_ALIGNMENT(TYPE, ALIGN) \
199   RISCV_EXPAND_ALIGNMENT (true, TYPE, ALIGN)
200 
201 /* Define if operations between registers always perform the operation
202    on the full register even if a narrower mode is specified.  */
203 #define WORD_REGISTER_OPERATIONS 1
204 
205 /* When in 64-bit mode, move insns will sign extend SImode and CCmode
206    moves.  All other references are zero extended.  */
207 #define LOAD_EXTEND_OP(MODE) \
208   (TARGET_64BIT && (MODE) == SImode ? SIGN_EXTEND : ZERO_EXTEND)
209 
210 /* Define this macro if it is advisable to hold scalars in registers
211    in a wider mode than that declared by the program.  In such cases,
212    the value is constrained to be within the bounds of the declared
213    type, but kept valid in the wider mode.  The signedness of the
214    extension may differ from that of the type.  */
215 
216 #define PROMOTE_MODE(MODE, UNSIGNEDP, TYPE)	\
217   if (GET_MODE_CLASS (MODE) == MODE_INT		\
218       && GET_MODE_SIZE (MODE) < UNITS_PER_WORD)	\
219     {						\
220       if ((MODE) == SImode)			\
221 	(UNSIGNEDP) = 0;			\
222       (MODE) = word_mode;			\
223     }
224 
225 /* Pmode is always the same as ptr_mode, but not always the same as word_mode.
226    Extensions of pointers to word_mode must be signed.  */
227 #define POINTERS_EXTEND_UNSIGNED false
228 
229 /* Define if loading short immediate values into registers sign extends.  */
230 #define SHORT_IMMEDIATES_SIGN_EXTEND 1
231 
232 /* Standard register usage.  */
233 
234 /* Number of hardware registers.  We have:
235 
236    - 32 integer registers
237    - 32 floating point registers
238    - 2 fake registers:
239 	- ARG_POINTER_REGNUM
240 	- FRAME_POINTER_REGNUM */
241 
242 #define FIRST_PSEUDO_REGISTER 66
243 
244 /* x0, sp, gp, and tp are fixed.  */
245 
246 #define FIXED_REGISTERS							\
247 { /* General registers.  */						\
248   1, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,			\
249   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,			\
250   /* Floating-point registers.  */					\
251   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,			\
252   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,			\
253   /* Others.  */							\
254   1, 1									\
255 }
256 
257 /* a0-a7, t0-t6, fa0-fa7, and ft0-ft11 are volatile across calls.
258    The call RTLs themselves clobber ra.  */
259 
260 #define CALL_USED_REGISTERS						\
261 { /* General registers.  */						\
262   1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1,			\
263   1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1,			\
264   /* Floating-point registers.  */					\
265   1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1,			\
266   1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1,			\
267   /* Others.  */							\
268   1, 1									\
269 }
270 
271 /* Select a register mode required for caller save of hard regno REGNO.
272    Contrary to what is documented, the default is not the smallest suitable
273    mode but the largest suitable mode for the given (REGNO, NREGS) pair and
274    it quickly creates paradoxical subregs that can be problematic.  */
275 #define HARD_REGNO_CALLER_SAVE_MODE(REGNO, NREGS, MODE) \
276   ((MODE) == VOIDmode ? choose_hard_reg_mode (REGNO, NREGS, NULL) : (MODE))
277 
278 /* Internal macros to classify an ISA register's type.  */
279 
280 #define GP_REG_FIRST 0
281 #define GP_REG_LAST  (TARGET_RVE ? 15 : 31)
282 #define GP_REG_NUM   (GP_REG_LAST - GP_REG_FIRST + 1)
283 
284 #define FP_REG_FIRST 32
285 #define FP_REG_LAST  63
286 #define FP_REG_NUM   (FP_REG_LAST - FP_REG_FIRST + 1)
287 
288 /* The DWARF 2 CFA column which tracks the return address from a
289    signal handler context.  This means that to maintain backwards
290    compatibility, no hard register can be assigned this column if it
291    would need to be handled by the DWARF unwinder.  */
292 #define DWARF_ALT_FRAME_RETURN_COLUMN 64
293 
294 #define GP_REG_P(REGNO)	\
295   ((unsigned int) ((int) (REGNO) - GP_REG_FIRST) < GP_REG_NUM)
296 #define FP_REG_P(REGNO)  \
297   ((unsigned int) ((int) (REGNO) - FP_REG_FIRST) < FP_REG_NUM)
298 
299 /* True when REGNO is in SIBCALL_REGS set.  */
300 #define SIBCALL_REG_P(REGNO)	\
301   TEST_HARD_REG_BIT (reg_class_contents[SIBCALL_REGS], REGNO)
302 
303 #define FP_REG_RTX_P(X) (REG_P (X) && FP_REG_P (REGNO (X)))
304 
305 /* Use s0 as the frame pointer if it is so requested.  */
306 #define HARD_FRAME_POINTER_REGNUM 8
307 #define STACK_POINTER_REGNUM 2
308 #define THREAD_POINTER_REGNUM 4
309 
310 /* These two registers don't really exist: they get eliminated to either
311    the stack or hard frame pointer.  */
312 #define ARG_POINTER_REGNUM 64
313 #define FRAME_POINTER_REGNUM 65
314 
315 /* Register in which static-chain is passed to a function.  */
316 #define STATIC_CHAIN_REGNUM (GP_TEMP_FIRST + 2)
317 
318 /* Registers used as temporaries in prologue/epilogue code.
319 
320    The prologue registers mustn't conflict with any
321    incoming arguments, the static chain pointer, or the frame pointer.
322    The epilogue temporary mustn't conflict with the return registers,
323    the frame pointer, the EH stack adjustment, or the EH data registers. */
324 
325 #define RISCV_PROLOGUE_TEMP_REGNUM (GP_TEMP_FIRST)
326 #define RISCV_PROLOGUE_TEMP(MODE) gen_rtx_REG (MODE, RISCV_PROLOGUE_TEMP_REGNUM)
327 
328 #define RISCV_CALL_ADDRESS_TEMP_REGNUM (GP_TEMP_FIRST + 1)
329 #define RISCV_CALL_ADDRESS_TEMP(MODE) \
330   gen_rtx_REG (MODE, RISCV_CALL_ADDRESS_TEMP_REGNUM)
331 
332 #define MCOUNT_NAME "_mcount"
333 
334 #define NO_PROFILE_COUNTERS 1
335 
336 /* Emit rtl for profiling.  Output assembler code to FILE
337    to call "_mcount" for profiling a function entry.  */
338 #define PROFILE_HOOK(LABEL)						\
339   {									\
340     rtx fun, ra;							\
341     ra = get_hard_reg_initial_val (Pmode, RETURN_ADDR_REGNUM);		\
342     fun = gen_rtx_SYMBOL_REF (Pmode, MCOUNT_NAME);			\
343     emit_library_call (fun, LCT_NORMAL, VOIDmode, ra, Pmode);		\
344   }
345 
346 /* All the work done in PROFILE_HOOK, but still required.  */
347 #define FUNCTION_PROFILER(STREAM, LABELNO) do { } while (0)
348 
349 /* Define this macro if it is as good or better to call a constant
350    function address than to call an address kept in a register.  */
351 #define NO_FUNCTION_CSE 1
352 
353 /* Define the classes of registers for register constraints in the
354    machine description.  Also define ranges of constants.
355 
356    One of the classes must always be named ALL_REGS and include all hard regs.
357    If there is more than one class, another class must be named NO_REGS
358    and contain no registers.
359 
360    The name GENERAL_REGS must be the name of a class (or an alias for
361    another name such as ALL_REGS).  This is the class of registers
362    that is allowed by "g" or "r" in a register constraint.
363    Also, registers outside this class are allocated only when
364    instructions express preferences for them.
365 
366    The classes must be numbered in nondecreasing order; that is,
367    a larger-numbered class must never be contained completely
368    in a smaller-numbered class.
369 
370    For any two classes, it is very desirable that there be another
371    class that represents their union.  */
372 
373 enum reg_class
374 {
375   NO_REGS,			/* no registers in set */
376   SIBCALL_REGS,			/* registers used by indirect sibcalls */
377   JALR_REGS,			/* registers used by indirect calls */
378   GR_REGS,			/* integer registers */
379   FP_REGS,			/* floating-point registers */
380   FRAME_REGS,			/* arg pointer and frame pointer */
381   ALL_REGS,			/* all registers */
382   LIM_REG_CLASSES		/* max value + 1 */
383 };
384 
385 #define N_REG_CLASSES (int) LIM_REG_CLASSES
386 
387 #define GENERAL_REGS GR_REGS
388 
389 /* An initializer containing the names of the register classes as C
390    string constants.  These names are used in writing some of the
391    debugging dumps.  */
392 
393 #define REG_CLASS_NAMES							\
394 {									\
395   "NO_REGS",								\
396   "SIBCALL_REGS",							\
397   "JALR_REGS",								\
398   "GR_REGS",								\
399   "FP_REGS",								\
400   "FRAME_REGS",								\
401   "ALL_REGS"								\
402 }
403 
404 /* An initializer containing the contents of the register classes,
405    as integers which are bit masks.  The Nth integer specifies the
406    contents of class N.  The way the integer MASK is interpreted is
407    that register R is in the class if `MASK & (1 << R)' is 1.
408 
409    When the machine has more than 32 registers, an integer does not
410    suffice.  Then the integers are replaced by sub-initializers,
411    braced groupings containing several integers.  Each
412    sub-initializer must be suitable as an initializer for the type
413    `HARD_REG_SET' which is defined in `hard-reg-set.h'.  */
414 
415 #define REG_CLASS_CONTENTS						\
416 {									\
417   { 0x00000000, 0x00000000, 0x00000000 },	/* NO_REGS */		\
418   { 0xf003fcc0, 0x00000000, 0x00000000 },	/* SIBCALL_REGS */	\
419   { 0xffffffc0, 0x00000000, 0x00000000 },	/* JALR_REGS */		\
420   { 0xffffffff, 0x00000000, 0x00000000 },	/* GR_REGS */		\
421   { 0x00000000, 0xffffffff, 0x00000000 },	/* FP_REGS */		\
422   { 0x00000000, 0x00000000, 0x00000003 },	/* FRAME_REGS */	\
423   { 0xffffffff, 0xffffffff, 0x00000003 }	/* ALL_REGS */		\
424 }
425 
426 /* A C expression whose value is a register class containing hard
427    register REGNO.  In general there is more that one such class;
428    choose a class which is "minimal", meaning that no smaller class
429    also contains the register.  */
430 
431 #define REGNO_REG_CLASS(REGNO) riscv_regno_to_class[ (REGNO) ]
432 
433 /* A macro whose definition is the name of the class to which a
434    valid base register must belong.  A base register is one used in
435    an address which is the register value plus a displacement.  */
436 
437 #define BASE_REG_CLASS GR_REGS
438 
439 /* A macro whose definition is the name of the class to which a
440    valid index register must belong.  An index register is one used
441    in an address where its value is either multiplied by a scale
442    factor or added to another register (as well as added to a
443    displacement).  */
444 
445 #define INDEX_REG_CLASS NO_REGS
446 
447 /* We generally want to put call-clobbered registers ahead of
448    call-saved ones.  (IRA expects this.)  */
449 
450 #define REG_ALLOC_ORDER							\
451 { \
452   /* Call-clobbered GPRs.  */						\
453   15, 14, 13, 12, 11, 10, 16, 17, 6, 28, 29, 30, 31, 5, 7, 1,		\
454   /* Call-saved GPRs.  */						\
455   8, 9, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27,	       			\
456   /* GPRs that can never be exposed to the register allocator.  */	\
457   0, 2, 3, 4,								\
458   /* Call-clobbered FPRs.  */						\
459   47, 46, 45, 44, 43, 42, 32, 33, 34, 35, 36, 37, 38, 39, 48, 49,	\
460   60, 61, 62, 63,							\
461   /* Call-saved FPRs.  */						\
462   40, 41, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59,			\
463   /* None of the remaining classes have defined call-saved		\
464      registers.  */							\
465   64, 65								\
466 }
467 
468 /* True if VALUE is a signed 12-bit number.  */
469 
470 #define SMALL_OPERAND(VALUE) \
471   ((unsigned HOST_WIDE_INT) (VALUE) + IMM_REACH/2 < IMM_REACH)
472 
473 /* True if VALUE can be loaded into a register using LUI.  */
474 
475 #define LUI_OPERAND(VALUE)						\
476   (((VALUE) | ((1UL<<31) - IMM_REACH)) == ((1UL<<31) - IMM_REACH)	\
477    || ((VALUE) | ((1UL<<31) - IMM_REACH)) + IMM_REACH == 0)
478 
479 /* Stack layout; function entry, exit and calling.  */
480 
481 #define STACK_GROWS_DOWNWARD 1
482 
483 #define FRAME_GROWS_DOWNWARD 1
484 
485 #define RETURN_ADDR_RTX riscv_return_addr
486 
487 #define ELIMINABLE_REGS							\
488 {{ ARG_POINTER_REGNUM,   STACK_POINTER_REGNUM},				\
489  { ARG_POINTER_REGNUM,   HARD_FRAME_POINTER_REGNUM},			\
490  { FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM},				\
491  { FRAME_POINTER_REGNUM, HARD_FRAME_POINTER_REGNUM}}				\
492 
493 #define INITIAL_ELIMINATION_OFFSET(FROM, TO, OFFSET) \
494   (OFFSET) = riscv_initial_elimination_offset (FROM, TO)
495 
496 /* Allocate stack space for arguments at the beginning of each function.  */
497 #define ACCUMULATE_OUTGOING_ARGS 1
498 
499 /* The argument pointer always points to the first argument.  */
500 #define FIRST_PARM_OFFSET(FNDECL) 0
501 
502 #define REG_PARM_STACK_SPACE(FNDECL) 0
503 
504 /* Define this if it is the responsibility of the caller to
505    allocate the area reserved for arguments passed in registers.
506    If `ACCUMULATE_OUTGOING_ARGS' is also defined, the only effect
507    of this macro is to determine whether the space is included in
508    `crtl->outgoing_args_size'.  */
509 #define OUTGOING_REG_PARM_STACK_SPACE(FNTYPE) 1
510 
511 #define PREFERRED_STACK_BOUNDARY riscv_stack_boundary
512 
513 /* Symbolic macros for the registers used to return integer and floating
514    point values.  */
515 
516 #define GP_RETURN GP_ARG_FIRST
517 #define FP_RETURN (UNITS_PER_FP_ARG == 0 ? GP_RETURN : FP_ARG_FIRST)
518 
519 #define MAX_ARGS_IN_REGISTERS (riscv_abi == ABI_ILP32E ? 6 : 8)
520 
521 /* Symbolic macros for the first/last argument registers.  */
522 
523 #define GP_ARG_FIRST (GP_REG_FIRST + 10)
524 #define GP_ARG_LAST  (GP_ARG_FIRST + MAX_ARGS_IN_REGISTERS - 1)
525 #define GP_TEMP_FIRST (GP_REG_FIRST + 5)
526 #define FP_ARG_FIRST (FP_REG_FIRST + 10)
527 #define FP_ARG_LAST  (FP_ARG_FIRST + MAX_ARGS_IN_REGISTERS - 1)
528 
529 #define CALLEE_SAVED_REG_NUMBER(REGNO)			\
530   ((REGNO) >= 8 && (REGNO) <= 9 ? (REGNO) - 8 :		\
531    (REGNO) >= 18 && (REGNO) <= 27 ? (REGNO) - 16 : -1)
532 
533 #define LIBCALL_VALUE(MODE) \
534   riscv_function_value (NULL_TREE, NULL_TREE, MODE)
535 
536 #define FUNCTION_VALUE(VALTYPE, FUNC) \
537   riscv_function_value (VALTYPE, FUNC, VOIDmode)
538 
539 #define FUNCTION_VALUE_REGNO_P(N) ((N) == GP_RETURN || (N) == FP_RETURN)
540 
541 /* 1 if N is a possible register number for function argument passing.
542    We have no FP argument registers when soft-float.  */
543 
544 /* Accept arguments in a0-a7, and in fa0-fa7 if permitted by the ABI.  */
545 #define FUNCTION_ARG_REGNO_P(N)						\
546   (IN_RANGE ((N), GP_ARG_FIRST, GP_ARG_LAST)				\
547    || (UNITS_PER_FP_ARG && IN_RANGE ((N), FP_ARG_FIRST, FP_ARG_LAST)))
548 
549 typedef struct {
550   /* Number of integer registers used so far, up to MAX_ARGS_IN_REGISTERS. */
551   unsigned int num_gprs;
552 
553   /* Number of floating-point registers used so far, likewise.  */
554   unsigned int num_fprs;
555 } CUMULATIVE_ARGS;
556 
557 /* Initialize a variable CUM of type CUMULATIVE_ARGS
558    for a call to a function whose data type is FNTYPE.
559    For a library call, FNTYPE is 0.  */
560 
561 #define INIT_CUMULATIVE_ARGS(CUM, FNTYPE, LIBNAME, INDIRECT, N_NAMED_ARGS) \
562   memset (&(CUM), 0, sizeof (CUM))
563 
564 #define EPILOGUE_USES(REGNO)	riscv_epilogue_uses (REGNO)
565 
566 /* Align based on stack boundary, which might have been set by the user.  */
567 #define RISCV_STACK_ALIGN(LOC) \
568   (((LOC) + ((PREFERRED_STACK_BOUNDARY/8)-1)) & -(PREFERRED_STACK_BOUNDARY/8))
569 
570 /* EXIT_IGNORE_STACK should be nonzero if, when returning from a function,
571    the stack pointer does not matter.  The value is tested only in
572    functions that have frame pointers.
573    No definition is equivalent to always zero.  */
574 
575 #define EXIT_IGNORE_STACK 1
576 
577 
578 /* Trampolines are a block of code followed by two pointers.  */
579 
580 #define TRAMPOLINE_CODE_SIZE 16
581 #define TRAMPOLINE_SIZE		\
582   ((Pmode == SImode)		\
583    ? TRAMPOLINE_CODE_SIZE	\
584    : (TRAMPOLINE_CODE_SIZE + POINTER_SIZE * 2))
585 #define TRAMPOLINE_ALIGNMENT POINTER_SIZE
586 
587 /* Addressing modes, and classification of registers for them.  */
588 
589 #define REGNO_OK_FOR_INDEX_P(REGNO) 0
590 #define REGNO_MODE_OK_FOR_BASE_P(REGNO, MODE) \
591   riscv_regno_mode_ok_for_base_p (REGNO, MODE, 1)
592 
593 /* The macros REG_OK_FOR..._P assume that the arg is a REG rtx
594    and check its validity for a certain class.
595    We have two alternate definitions for each of them.
596    The usual definition accepts all pseudo regs; the other rejects them all.
597    The symbol REG_OK_STRICT causes the latter definition to be used.
598 
599    Most source files want to accept pseudo regs in the hope that
600    they will get allocated to the class that the insn wants them to be in.
601    Some source files that are used after register allocation
602    need to be strict.  */
603 
604 #ifndef REG_OK_STRICT
605 #define REG_MODE_OK_FOR_BASE_P(X, MODE) \
606   riscv_regno_mode_ok_for_base_p (REGNO (X), MODE, 0)
607 #else
608 #define REG_MODE_OK_FOR_BASE_P(X, MODE) \
609   riscv_regno_mode_ok_for_base_p (REGNO (X), MODE, 1)
610 #endif
611 
612 #define REG_OK_FOR_INDEX_P(X) 0
613 
614 /* Maximum number of registers that can appear in a valid memory address.  */
615 
616 #define MAX_REGS_PER_ADDRESS 1
617 
618 #define CONSTANT_ADDRESS_P(X) \
619   (CONSTANT_P (X) && memory_address_p (SImode, X))
620 
621 /* This handles the magic '..CURRENT_FUNCTION' symbol, which means
622    'the start of the function that this code is output in'.  */
623 
624 #define ASM_OUTPUT_LABELREF(FILE,NAME)					\
625   do {									\
626     if (strcmp (NAME, "..CURRENT_FUNCTION") == 0)			\
627       asm_fprintf ((FILE), "%U%s",					\
628 		   XSTR (XEXP (DECL_RTL (current_function_decl),	\
629 			       0), 0));					\
630     else								\
631       asm_fprintf ((FILE), "%U%s", (NAME));				\
632   } while (0)
633 
634 #define JUMP_TABLES_IN_TEXT_SECTION 0
635 #define CASE_VECTOR_MODE SImode
636 #define CASE_VECTOR_PC_RELATIVE (riscv_cmodel != CM_MEDLOW)
637 
638 /* The load-address macro is used for PC-relative addressing of symbols
639    that bind locally.  Don't use it for symbols that should be addressed
640    via the GOT.  Also, avoid it for CM_MEDLOW, where LUI addressing
641    currently results in more opportunities for linker relaxation.  */
642 #define USE_LOAD_ADDRESS_MACRO(sym)					\
643   (!TARGET_EXPLICIT_RELOCS &&						\
644    ((flag_pic								\
645      && ((SYMBOL_REF_P (sym) && SYMBOL_REF_LOCAL_P (sym))		\
646 	 || ((GET_CODE (sym) == CONST)					\
647 	     && SYMBOL_REF_P (XEXP (XEXP (sym, 0),0))			\
648 	     && SYMBOL_REF_LOCAL_P (XEXP (XEXP (sym, 0),0)))))		\
649      || riscv_cmodel == CM_MEDANY))
650 
651 /* Define this as 1 if `char' should by default be signed; else as 0.  */
652 #define DEFAULT_SIGNED_CHAR 0
653 
654 #define MOVE_MAX UNITS_PER_WORD
655 #define MAX_MOVE_MAX 8
656 
657 /* The SPARC port says:
658    Nonzero if access to memory by bytes is slow and undesirable.
659    For RISC chips, it means that access to memory by bytes is no
660    better than access by words when possible, so grab a whole word
661    and maybe make use of that.  */
662 #define SLOW_BYTE_ACCESS 1
663 
664 /* Using SHIFT_COUNT_TRUNCATED is discouraged, so we handle this with patterns
665    in the md file instead.  */
666 #define SHIFT_COUNT_TRUNCATED 0
667 
668 /* Specify the machine mode that pointers have.
669    After generation of rtl, the compiler makes no further distinction
670    between pointers and any other objects of this machine mode.  */
671 
672 #define Pmode word_mode
673 
674 /* Give call MEMs SImode since it is the "most permissive" mode
675    for both 32-bit and 64-bit targets.  */
676 
677 #define FUNCTION_MODE SImode
678 
679 /* A C expression for the cost of a branch instruction.  A value of 2
680    seems to minimize code size.  */
681 
682 #define BRANCH_COST(speed_p, predictable_p) \
683   ((!(speed_p) || (predictable_p)) ? 2 : riscv_branch_cost)
684 
685 /* True if the target optimizes short forward branches around integer
686    arithmetic instructions into predicated operations, e.g., for
687    conditional-move operations.  The macro assumes that all branch
688    instructions (BEQ, BNE, BLT, BLTU, BGE, BGEU, C.BEQZ, and C.BNEZ)
689    support this feature.  The macro further assumes that any integer
690    arithmetic and logical operation (ADD[I], SUB, SLL[I], SRL[I], SRA[I],
691    SLT[I][U], AND[I], XOR[I], OR[I], LUI, AUIPC, and their compressed
692    counterparts, including C.MV and C.LI) can be in the branch shadow.  */
693 
694 #define TARGET_SFB_ALU (riscv_microarchitecture == sifive_7)
695 
696 #define LOGICAL_OP_NON_SHORT_CIRCUIT 0
697 
698 /* Control the assembler format that we output.  */
699 
700 /* Output to assembler file text saying following lines
701    may contain character constants, extra white space, comments, etc.  */
702 
703 #ifndef ASM_APP_ON
704 #define ASM_APP_ON " #APP\n"
705 #endif
706 
707 /* Output to assembler file text saying following lines
708    no longer contain unusual constructs.  */
709 
710 #ifndef ASM_APP_OFF
711 #define ASM_APP_OFF " #NO_APP\n"
712 #endif
713 
714 #define REGISTER_NAMES						\
715 { "zero","ra",  "sp",  "gp",  "tp",  "t0",  "t1",  "t2",	\
716   "s0",  "s1",  "a0",  "a1",  "a2",  "a3",  "a4",  "a5",	\
717   "a6",  "a7",  "s2",  "s3",  "s4",  "s5",  "s6",  "s7",	\
718   "s8",  "s9",  "s10", "s11", "t3",  "t4",  "t5",  "t6",	\
719   "ft0", "ft1", "ft2", "ft3", "ft4", "ft5", "ft6", "ft7",	\
720   "fs0", "fs1", "fa0", "fa1", "fa2", "fa3", "fa4", "fa5",	\
721   "fa6", "fa7", "fs2", "fs3", "fs4", "fs5", "fs6", "fs7",	\
722   "fs8", "fs9", "fs10","fs11","ft8", "ft9", "ft10","ft11",	\
723   "arg", "frame", }
724 
725 #define ADDITIONAL_REGISTER_NAMES					\
726 {									\
727   { "x0",	 0 + GP_REG_FIRST },					\
728   { "x1",	 1 + GP_REG_FIRST },					\
729   { "x2",	 2 + GP_REG_FIRST },					\
730   { "x3",	 3 + GP_REG_FIRST },					\
731   { "x4",	 4 + GP_REG_FIRST },					\
732   { "x5",	 5 + GP_REG_FIRST },					\
733   { "x6",	 6 + GP_REG_FIRST },					\
734   { "x7",	 7 + GP_REG_FIRST },					\
735   { "x8",	 8 + GP_REG_FIRST },					\
736   { "x9",	 9 + GP_REG_FIRST },					\
737   { "x10",	10 + GP_REG_FIRST },					\
738   { "x11",	11 + GP_REG_FIRST },					\
739   { "x12",	12 + GP_REG_FIRST },					\
740   { "x13",	13 + GP_REG_FIRST },					\
741   { "x14",	14 + GP_REG_FIRST },					\
742   { "x15",	15 + GP_REG_FIRST },					\
743   { "x16",	16 + GP_REG_FIRST },					\
744   { "x17",	17 + GP_REG_FIRST },					\
745   { "x18",	18 + GP_REG_FIRST },					\
746   { "x19",	19 + GP_REG_FIRST },					\
747   { "x20",	20 + GP_REG_FIRST },					\
748   { "x21",	21 + GP_REG_FIRST },					\
749   { "x22",	22 + GP_REG_FIRST },					\
750   { "x23",	23 + GP_REG_FIRST },					\
751   { "x24",	24 + GP_REG_FIRST },					\
752   { "x25",	25 + GP_REG_FIRST },					\
753   { "x26",	26 + GP_REG_FIRST },					\
754   { "x27",	27 + GP_REG_FIRST },					\
755   { "x28",	28 + GP_REG_FIRST },					\
756   { "x29",	29 + GP_REG_FIRST },					\
757   { "x30",	30 + GP_REG_FIRST },					\
758   { "x31",	31 + GP_REG_FIRST },					\
759   { "f0",	 0 + FP_REG_FIRST },					\
760   { "f1",	 1 + FP_REG_FIRST },					\
761   { "f2",	 2 + FP_REG_FIRST },					\
762   { "f3",	 3 + FP_REG_FIRST },					\
763   { "f4",	 4 + FP_REG_FIRST },					\
764   { "f5",	 5 + FP_REG_FIRST },					\
765   { "f6",	 6 + FP_REG_FIRST },					\
766   { "f7",	 7 + FP_REG_FIRST },					\
767   { "f8",	 8 + FP_REG_FIRST },					\
768   { "f9",	 9 + FP_REG_FIRST },					\
769   { "f10",	10 + FP_REG_FIRST },					\
770   { "f11",	11 + FP_REG_FIRST },					\
771   { "f12",	12 + FP_REG_FIRST },					\
772   { "f13",	13 + FP_REG_FIRST },					\
773   { "f14",	14 + FP_REG_FIRST },					\
774   { "f15",	15 + FP_REG_FIRST },					\
775   { "f16",	16 + FP_REG_FIRST },					\
776   { "f17",	17 + FP_REG_FIRST },					\
777   { "f18",	18 + FP_REG_FIRST },					\
778   { "f19",	19 + FP_REG_FIRST },					\
779   { "f20",	20 + FP_REG_FIRST },					\
780   { "f21",	21 + FP_REG_FIRST },					\
781   { "f22",	22 + FP_REG_FIRST },					\
782   { "f23",	23 + FP_REG_FIRST },					\
783   { "f24",	24 + FP_REG_FIRST },					\
784   { "f25",	25 + FP_REG_FIRST },					\
785   { "f26",	26 + FP_REG_FIRST },					\
786   { "f27",	27 + FP_REG_FIRST },					\
787   { "f28",	28 + FP_REG_FIRST },					\
788   { "f29",	29 + FP_REG_FIRST },					\
789   { "f30",	30 + FP_REG_FIRST },					\
790   { "f31",	31 + FP_REG_FIRST },					\
791 }
792 
793 /* Globalizing directive for a label.  */
794 #define GLOBAL_ASM_OP "\t.globl\t"
795 
796 /* This is how to store into the string LABEL
797    the symbol_ref name of an internal numbered label where
798    PREFIX is the class of label and NUM is the number within the class.
799    This is suitable for output with `assemble_name'.  */
800 
801 #undef ASM_GENERATE_INTERNAL_LABEL
802 #define ASM_GENERATE_INTERNAL_LABEL(LABEL,PREFIX,NUM)			\
803   sprintf ((LABEL), "*%s%s%ld", (LOCAL_LABEL_PREFIX), (PREFIX), (long)(NUM))
804 
805 /* This is how to output an element of a case-vector that is absolute.  */
806 
807 #define ASM_OUTPUT_ADDR_VEC_ELT(STREAM, VALUE)				\
808   fprintf (STREAM, "\t.word\t%sL%d\n", LOCAL_LABEL_PREFIX, VALUE)
809 
810 /* This is how to output an element of a PIC case-vector. */
811 
812 #define ASM_OUTPUT_ADDR_DIFF_ELT(STREAM, BODY, VALUE, REL)		\
813   fprintf (STREAM, "\t.word\t%sL%d-%sL%d\n",				\
814 	   LOCAL_LABEL_PREFIX, VALUE, LOCAL_LABEL_PREFIX, REL)
815 
816 /* This is how to output an assembler line
817    that says to advance the location counter
818    to a multiple of 2**LOG bytes.  */
819 
820 #define ASM_OUTPUT_ALIGN(STREAM,LOG)					\
821   fprintf (STREAM, "\t.align\t%d\n", (LOG))
822 
823 /* Define the strings to put out for each section in the object file.  */
824 #define TEXT_SECTION_ASM_OP	"\t.text"	/* instructions */
825 #define DATA_SECTION_ASM_OP	"\t.data"	/* large data */
826 #define READONLY_DATA_SECTION_ASM_OP	"\t.section\t.rodata"
827 #define BSS_SECTION_ASM_OP	"\t.bss"
828 #define SBSS_SECTION_ASM_OP	"\t.section\t.sbss,\"aw\",@nobits"
829 #define SDATA_SECTION_ASM_OP	"\t.section\t.sdata,\"aw\",@progbits"
830 
831 #define ASM_OUTPUT_REG_PUSH(STREAM,REGNO)				\
832 do									\
833   {									\
834     fprintf (STREAM, "\taddi\t%s,%s,-8\n\t%s\t%s,0(%s)\n",		\
835 	     reg_names[STACK_POINTER_REGNUM],				\
836 	     reg_names[STACK_POINTER_REGNUM],				\
837 	     TARGET_64BIT ? "sd" : "sw",				\
838 	     reg_names[REGNO],						\
839 	     reg_names[STACK_POINTER_REGNUM]);				\
840   }									\
841 while (0)
842 
843 #define ASM_OUTPUT_REG_POP(STREAM,REGNO)				\
844 do									\
845   {									\
846     fprintf (STREAM, "\t%s\t%s,0(%s)\n\taddi\t%s,%s,8\n",		\
847 	     TARGET_64BIT ? "ld" : "lw",				\
848 	     reg_names[REGNO],						\
849 	     reg_names[STACK_POINTER_REGNUM],				\
850 	     reg_names[STACK_POINTER_REGNUM],				\
851 	     reg_names[STACK_POINTER_REGNUM]);				\
852   }									\
853 while (0)
854 
855 #define ASM_COMMENT_START "#"
856 
857 #undef SIZE_TYPE
858 #define SIZE_TYPE (POINTER_SIZE == 64 ? "long unsigned int" : "unsigned int")
859 
860 #undef PTRDIFF_TYPE
861 #define PTRDIFF_TYPE (POINTER_SIZE == 64 ? "long int" : "int")
862 
863 /* The maximum number of bytes copied by one iteration of a cpymemsi loop.  */
864 
865 #define RISCV_MAX_MOVE_BYTES_PER_LOOP_ITER (UNITS_PER_WORD * 4)
866 
867 /* The maximum number of bytes that can be copied by a straight-line
868    cpymemsi implementation.  */
869 
870 #define RISCV_MAX_MOVE_BYTES_STRAIGHT (RISCV_MAX_MOVE_BYTES_PER_LOOP_ITER * 3)
871 
872 /* If a memory-to-memory move would take MOVE_RATIO or more simple
873    move-instruction pairs, we will do a cpymem or libcall instead.
874    Do not use move_by_pieces at all when strict alignment is not
875    in effect but the target has slow unaligned accesses; in this
876    case, cpymem or libcall is more efficient.  */
877 
878 #define MOVE_RATIO(speed)						\
879   (!STRICT_ALIGNMENT && riscv_slow_unaligned_access_p ? 1 :		\
880    (speed) ? RISCV_MAX_MOVE_BYTES_PER_LOOP_ITER / UNITS_PER_WORD :	\
881    CLEAR_RATIO (speed) / 2)
882 
883 /* For CLEAR_RATIO, when optimizing for size, give a better estimate
884    of the length of a memset call, but use the default otherwise.  */
885 
886 #define CLEAR_RATIO(speed) ((speed) ? 16 : 6)
887 
888 /* This is similar to CLEAR_RATIO, but for a non-zero constant, so when
889    optimizing for size adjust the ratio to account for the overhead of
890    loading the constant and replicating it across the word.  */
891 
892 #define SET_RATIO(speed) (CLEAR_RATIO (speed) - ((speed) ? 0 : 2))
893 
894 #ifndef USED_FOR_TARGET
895 extern const enum reg_class riscv_regno_to_class[];
896 extern bool riscv_slow_unaligned_access_p;
897 extern unsigned riscv_stack_boundary;
898 #endif
899 
900 #define ASM_PREFERRED_EH_DATA_FORMAT(CODE,GLOBAL) \
901   (((GLOBAL) ? DW_EH_PE_indirect : 0) | DW_EH_PE_pcrel | DW_EH_PE_sdata4)
902 
903 #define XLEN_SPEC \
904   "%{march=rv32*:32}" \
905   "%{march=rv64*:64}" \
906 
907 #define ABI_SPEC \
908   "%{mabi=ilp32:ilp32}" \
909   "%{mabi=ilp32e:ilp32e}" \
910   "%{mabi=ilp32f:ilp32f}" \
911   "%{mabi=ilp32d:ilp32d}" \
912   "%{mabi=lp64:lp64}" \
913   "%{mabi=lp64f:lp64f}" \
914   "%{mabi=lp64d:lp64d}" \
915 
916 /* ISA constants needed for code generation.  */
917 #define OPCODE_LW    0x2003
918 #define OPCODE_LD    0x3003
919 #define OPCODE_AUIPC 0x17
920 #define OPCODE_JALR  0x67
921 #define OPCODE_LUI   0x37
922 #define OPCODE_ADDI  0x13
923 #define SHIFT_RD  7
924 #define SHIFT_RS1 15
925 #define SHIFT_IMM 20
926 #define IMM_BITS 12
927 #define C_SxSP_BITS 6
928 
929 #define IMM_REACH (1LL << IMM_BITS)
930 #define CONST_HIGH_PART(VALUE) (((VALUE) + (IMM_REACH/2)) & ~(IMM_REACH-1))
931 #define CONST_LOW_PART(VALUE) ((VALUE) - CONST_HIGH_PART (VALUE))
932 
933 #define SWSP_REACH (4LL << C_SxSP_BITS)
934 #define SDSP_REACH (8LL << C_SxSP_BITS)
935 
936 /* Called from RISCV_REORG, this is defined in riscv-sr.c.  */
937 
938 extern void riscv_remove_unneeded_save_restore_calls (void);
939 
940 #define HARD_REGNO_RENAME_OK(FROM, TO) riscv_hard_regno_rename_ok (FROM, TO)
941 
942 #endif /* ! GCC_RISCV_H */
943