1 /* Target hook definitions.
2 Copyright (C) 2001-2020 Free Software Foundation, Inc.
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
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.
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/>.
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! */
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"
27 #define HOOK_TYPE "Target Hook"
29 HOOK_VECTOR (TARGET_INITIALIZER, gcc_target)
31 /* Functions that output assembler for the target. */
32 #define HOOK_PREFIX "TARGET_ASM_"
33 HOOK_VECTOR (TARGET_ASM_OUT, asm_out)
35 /* Opening and closing parentheses for asm expression grouping. */
38 "These target hooks are C string constants, describing the syntax in the\n\
39 assembler for grouping arithmetic expressions. If not overridden, they\n\
40 default to normal parentheses, which is correct for most assemblers.",
42 DEFHOOKPODX (close_paren, const char *, ")")
44 /* Assembler instructions for creating various kinds of integer object. */
47 "@deftypevrx {Target Hook} {const char *} TARGET_ASM_ALIGNED_HI_OP\n\
48 @deftypevrx {Target Hook} {const char *} TARGET_ASM_ALIGNED_PSI_OP\n\
49 @deftypevrx {Target Hook} {const char *} TARGET_ASM_ALIGNED_SI_OP\n\
50 @deftypevrx {Target Hook} {const char *} TARGET_ASM_ALIGNED_PDI_OP\n\
51 @deftypevrx {Target Hook} {const char *} TARGET_ASM_ALIGNED_DI_OP\n\
52 @deftypevrx {Target Hook} {const char *} TARGET_ASM_ALIGNED_PTI_OP\n\
53 @deftypevrx {Target Hook} {const char *} TARGET_ASM_ALIGNED_TI_OP\n\
54 @deftypevrx {Target Hook} {const char *} TARGET_ASM_UNALIGNED_HI_OP\n\
55 @deftypevrx {Target Hook} {const char *} TARGET_ASM_UNALIGNED_PSI_OP\n\
56 @deftypevrx {Target Hook} {const char *} TARGET_ASM_UNALIGNED_SI_OP\n\
57 @deftypevrx {Target Hook} {const char *} TARGET_ASM_UNALIGNED_PDI_OP\n\
58 @deftypevrx {Target Hook} {const char *} TARGET_ASM_UNALIGNED_DI_OP\n\
59 @deftypevrx {Target Hook} {const char *} TARGET_ASM_UNALIGNED_PTI_OP\n\
60 @deftypevrx {Target Hook} {const char *} TARGET_ASM_UNALIGNED_TI_OP\n\
61 These hooks specify assembly directives for creating certain kinds\n\
62 of integer object. The @code{TARGET_ASM_BYTE_OP} directive creates a\n\
63 byte-sized object, the @code{TARGET_ASM_ALIGNED_HI_OP} one creates an\n\
64 aligned two-byte object, and so on. Any of the hooks may be\n\
65 @code{NULL}, indicating that no suitable directive is available.\n\
67 The compiler will print these strings at the start of a new line,\n\
68 followed immediately by the object's initial value. In most cases,\n\
69 the string should contain a tab, a pseudo-op, and then another tab.",
70 const char *, "\t.byte\t")
71 DEFHOOKPOD (aligned_op, "*", struct asm_int_op, TARGET_ASM_ALIGNED_INT_OP)
72 DEFHOOKPOD (unaligned_op, "*", struct asm_int_op, TARGET_ASM_UNALIGNED_INT_OP)
74 /* Try to output the assembler code for an integer object whose
75 value is given by X. SIZE is the size of the object in bytes and
76 ALIGNED_P indicates whether it is aligned. Return true if
77 successful. Only handles cases for which BYTE_OP, ALIGNED_OP
78 and UNALIGNED_OP are NULL. */
81 "The @code{assemble_integer} function uses this hook to output an\n\
82 integer object. @var{x} is the object's value, @var{size} is its size\n\
83 in bytes and @var{aligned_p} indicates whether it is aligned. The\n\
84 function should return @code{true} if it was able to output the\n\
85 object. If it returns false, @code{assemble_integer} will try to\n\
86 split the object into smaller parts.\n\
88 The default implementation of this hook will use the\n\
89 @code{TARGET_ASM_BYTE_OP} family of strings, returning @code{false}\n\
90 when the relevant string is @code{NULL}.",
91 /* Only handles cases for which BYTE_OP, ALIGNED_OP and UNALIGNED_OP are
93 bool, (rtx x, unsigned int size, int aligned_p),
94 default_assemble_integer)
96 /* Assembly strings required after the .cfi_startproc label. */
99 "This target hook is used to emit assembly strings required by the target\n\
100 after the .cfi_startproc directive. The first argument is the file stream to\n\
101 write the strings to and the second argument is the function\'s declaration. The\n\
102 expected use is to add more .cfi_* directives.\n\
104 The default is to not output any assembly strings.",
105 void, (FILE *, tree),
106 hook_void_FILEptr_tree)
108 /* Notify the backend that we have completed emitting the data for a
112 "Define this hook if the target assembler requires a special marker to\n\
113 terminate an initialized variable declaration.",
117 /* Output code that will globalize a label. */
120 "This target hook is a function to output to the stdio stream\n\
121 @var{stream} some commands that will make the label @var{name} global;\n\
122 that is, available for reference from other files.\n\
124 The default implementation relies on a proper definition of\n\
125 @code{GLOBAL_ASM_OP}.",
126 void, (FILE *stream, const char *name),
127 default_globalize_label)
129 /* Output code that will globalize a declaration. */
131 (globalize_decl_name,
132 "This target hook is a function to output to the stdio stream\n\
133 @var{stream} some commands that will make the name associated with @var{decl}\n\
134 global; that is, available for reference from other files.\n\
136 The default implementation uses the TARGET_ASM_GLOBALIZE_LABEL target hook.",
137 void, (FILE *stream, tree decl), default_globalize_decl_name)
139 /* Output code that will declare an external variable. */
141 (assemble_undefined_decl,
142 "This target hook is a function to output to the stdio stream\n\
143 @var{stream} some commands that will declare the name associated with\n\
144 @var{decl} which is not defined in the current translation unit. Most\n\
145 assemblers do not require anything to be output in this case.",
146 void, (FILE *stream, const char *name, const_tree decl),
147 hook_void_FILEptr_constcharptr_const_tree)
149 /* Output code that will emit a label for unwind info, if this
150 target requires such labels. Second argument is the decl the
151 unwind info is associated with, third is a boolean: true if
152 this is for exception handling, fourth is a boolean: true if
153 this is only a placeholder for an omitted FDE. */
156 "This target hook emits a label at the beginning of each FDE@. It\n\
157 should be defined on targets where FDEs need special labels, and it\n\
158 should write the appropriate label, for the FDE associated with the\n\
159 function declaration @var{decl}, to the stdio stream @var{stream}.\n\
160 The third argument, @var{for_eh}, is a boolean: true if this is for an\n\
161 exception table. The fourth argument, @var{empty}, is a boolean:\n\
162 true if this is a placeholder label for an omitted FDE@.\n\
164 The default is that FDEs are not given nonlocal labels.",
165 void, (FILE *stream, tree decl, int for_eh, int empty),
166 default_emit_unwind_label)
168 /* Output code that will emit a label to divide up the exception table. */
170 (emit_except_table_label,
171 "This target hook emits a label at the beginning of the exception table.\n\
172 It should be defined on targets where it is desirable for the table\n\
173 to be broken up according to function.\n\
175 The default is that no label is emitted.",
176 void, (FILE *stream),
177 default_emit_except_table_label)
179 /* Emit a directive for setting the personality for the function. */
181 (emit_except_personality,
182 "If the target implements @code{TARGET_ASM_UNWIND_EMIT}, this hook may be\
183 used to emit a directive to install a personality hook into the unwind\
184 info. This hook should not be used if dwarf2 unwind info is used.",
185 void, (rtx personality),
188 /* Emit any directives required to unwind this instruction. */
191 "This target hook emits assembly directives required to unwind the\n\
192 given instruction. This is only used when @code{TARGET_EXCEPT_UNWIND_INFO}\n\
193 returns @code{UI_TARGET}.",
194 void, (FILE *stream, rtx_insn *insn),
198 (unwind_emit_before_insn,
199 "True if the @code{TARGET_ASM_UNWIND_EMIT} hook should be called before\
200 the assembly for @var{insn} has been emitted, false if the hook should\
201 be called afterward.",
204 /* Generate an internal label.
205 For now this is just a wrapper for ASM_GENERATE_INTERNAL_LABEL. */
207 (generate_internal_label,
209 void, (char *buf, const char *prefix, unsigned long labelno),
210 default_generate_internal_label)
212 /* Output an internal label. */
215 "A function to output to the stdio stream @var{stream} a label whose\n\
216 name is made from the string @var{prefix} and the number @var{labelno}.\n\
218 It is absolutely essential that these labels be distinct from the labels\n\
219 used for user-level functions and variables. Otherwise, certain programs\n\
220 will have name conflicts with internal labels.\n\
222 It is desirable to exclude internal labels from the symbol table of the\n\
223 object file. Most assemblers have a naming convention for labels that\n\
224 should be excluded; on many systems, the letter @samp{L} at the\n\
225 beginning of a label has this effect. You should find out what\n\
226 convention your system uses, and follow it.\n\
228 The default version of this function utilizes @code{ASM_GENERATE_INTERNAL_LABEL}.",
229 void, (FILE *stream, const char *prefix, unsigned long labelno),
230 default_internal_label)
232 /* Output label for the constant. */
234 (declare_constant_name,
235 "A target hook to output to the stdio stream @var{file} any text necessary\n\
236 for declaring the name @var{name} of a constant which is being defined. This\n\
237 target hook is responsible for outputting the label definition (perhaps using\n\
238 @code{assemble_label}). The argument @var{exp} is the value of the constant,\n\
239 and @var{size} is the size of the constant in bytes. The @var{name}\n\
240 will be an internal label.\n\
242 The default version of this target hook, define the @var{name} in the\n\
243 usual manner as a label (by means of @code{assemble_label}).\n\
245 You may wish to use @code{ASM_OUTPUT_TYPE_DIRECTIVE} in this target hook.",
246 void, (FILE *file, const char *name, const_tree expr, HOST_WIDE_INT size),
247 default_asm_declare_constant_name)
249 /* Emit a ttype table reference to a typeinfo object. */
252 "This hook is used to output a reference from a frame unwinding table to\n\
253 the type_info object identified by @var{sym}. It should return @code{true}\n\
254 if the reference was output. Returning @code{false} will cause the\n\
255 reference to be output using the normal Dwarf2 routines.",
259 /* Emit an assembler directive to set visibility for the symbol
260 associated with the tree decl. */
262 (assemble_visibility,
263 "This target hook is a function to output to @var{asm_out_file} some\n\
264 commands that will make the symbol(s) associated with @var{decl} have\n\
265 hidden, protected or internal visibility as specified by @var{visibility}.",
266 void, (tree decl, int visibility),
267 default_assemble_visibility)
270 (print_patchable_function_entry,
271 "Generate a patchable area at the function start, consisting of\n\
272 @var{patch_area_size} NOP instructions. If the target supports named\n\
273 sections and if @var{record_p} is true, insert a pointer to the current\n\
274 location in the table of patchable functions. The default implementation\n\
275 of the hook places the table of pointers in the special section named\n\
276 @code{__patchable_function_entries}.",
277 void, (FILE *file, unsigned HOST_WIDE_INT patch_area_size, bool record_p),
278 default_print_patchable_function_entry)
280 /* Output the assembler code for entry to a function. */
283 "If defined, a function that outputs the assembler code for entry to a\n\
284 function. The prologue is responsible for setting up the stack frame,\n\
285 initializing the frame pointer register, saving registers that must be\n\
286 saved, and allocating @var{size} additional bytes of storage for the\n\
287 local variables. @var{file} is a stdio stream to which the assembler\n\
288 code should be output.\n\
290 The label for the beginning of the function need not be output by this\n\
291 macro. That has already been done when the macro is run.\n\
293 @findex regs_ever_live\n\
294 To determine which registers to save, the macro can refer to the array\n\
295 @code{regs_ever_live}: element @var{r} is nonzero if hard register\n\
296 @var{r} is used anywhere within the function. This implies the function\n\
297 prologue should save register @var{r}, provided it is not one of the\n\
298 call-used registers. (@code{TARGET_ASM_FUNCTION_EPILOGUE} must likewise use\n\
299 @code{regs_ever_live}.)\n\
301 On machines that have ``register windows'', the function entry code does\n\
302 not save on the stack the registers that are in the windows, even if\n\
303 they are supposed to be preserved by function calls; instead it takes\n\
304 appropriate steps to ``push'' the register stack, if any non-call-used\n\
305 registers are used in the function.\n\
307 @findex frame_pointer_needed\n\
308 On machines where functions may or may not have frame-pointers, the\n\
309 function entry code must vary accordingly; it must set up the frame\n\
310 pointer if one is wanted, and not otherwise. To determine whether a\n\
311 frame pointer is in wanted, the macro can refer to the variable\n\
312 @code{frame_pointer_needed}. The variable's value will be 1 at run\n\
313 time in a function that needs a frame pointer. @xref{Elimination}.\n\
315 The function entry code is responsible for allocating any stack space\n\
316 required for the function. This stack space consists of the regions\n\
317 listed below. In most cases, these regions are allocated in the\n\
318 order listed, with the last listed region closest to the top of the\n\
319 stack (the lowest address if @code{STACK_GROWS_DOWNWARD} is defined, and\n\
320 the highest address if it is not defined). You can use a different order\n\
321 for a machine if doing so is more convenient or required for\n\
322 compatibility reasons. Except in cases where required by standard\n\
323 or by a debugger, there is no reason why the stack layout used by GCC\n\
324 need agree with that used by other compilers for a machine.",
326 default_function_pro_epilogue)
328 /* Output the assembler code for end of prologue. */
330 (function_end_prologue,
331 "If defined, a function that outputs assembler code at the end of a\n\
332 prologue. This should be used when the function prologue is being\n\
333 emitted as RTL, and you have some extra assembler that needs to be\n\
334 emitted. @xref{prologue instruction pattern}.",
338 /* Output the assembler code for start of epilogue. */
340 (function_begin_epilogue,
341 "If defined, a function that outputs assembler code at the start of an\n\
342 epilogue. This should be used when the function epilogue is being\n\
343 emitted as RTL, and you have some extra assembler that needs to be\n\
344 emitted. @xref{epilogue instruction pattern}.",
348 /* Output the assembler code for function exit. */
351 "If defined, a function that outputs the assembler code for exit from a\n\
352 function. The epilogue is responsible for restoring the saved\n\
353 registers and stack pointer to their values when the function was\n\
354 called, and returning control to the caller. This macro takes the\n\
355 same argument as the macro @code{TARGET_ASM_FUNCTION_PROLOGUE}, and the\n\
356 registers to restore are determined from @code{regs_ever_live} and\n\
357 @code{CALL_USED_REGISTERS} in the same way.\n\
359 On some machines, there is a single instruction that does all the work\n\
360 of returning from the function. On these machines, give that\n\
361 instruction the name @samp{return} and do not define the macro\n\
362 @code{TARGET_ASM_FUNCTION_EPILOGUE} at all.\n\
364 Do not define a pattern named @samp{return} if you want the\n\
365 @code{TARGET_ASM_FUNCTION_EPILOGUE} to be used. If you want the target\n\
366 switches to control whether return instructions or epilogues are used,\n\
367 define a @samp{return} pattern with a validity condition that tests the\n\
368 target switches appropriately. If the @samp{return} pattern's validity\n\
369 condition is false, epilogues will be used.\n\
371 On machines where functions may or may not have frame-pointers, the\n\
372 function exit code must vary accordingly. Sometimes the code for these\n\
373 two cases is completely different. To determine whether a frame pointer\n\
374 is wanted, the macro can refer to the variable\n\
375 @code{frame_pointer_needed}. The variable's value will be 1 when compiling\n\
376 a function that needs a frame pointer.\n\
378 Normally, @code{TARGET_ASM_FUNCTION_PROLOGUE} and\n\
379 @code{TARGET_ASM_FUNCTION_EPILOGUE} must treat leaf functions specially.\n\
380 The C variable @code{current_function_is_leaf} is nonzero for such a\n\
381 function. @xref{Leaf Functions}.\n\
383 On some machines, some functions pop their arguments on exit while\n\
384 others leave that for the caller to do. For example, the 68020 when\n\
385 given @option{-mrtd} pops arguments in functions that take a fixed\n\
386 number of arguments.\n\
389 @findex crtl->args.pops_args\n\
390 Your definition of the macro @code{RETURN_POPS_ARGS} decides which\n\
391 functions pop their own arguments. @code{TARGET_ASM_FUNCTION_EPILOGUE}\n\
392 needs to know what was decided. The number of bytes of the current\n\
393 function's arguments that this function should pop is available in\n\
394 @code{crtl->args.pops_args}. @xref{Scalar Return}.",
396 default_function_pro_epilogue)
398 /* Initialize target-specific sections. */
401 "Define this hook if you need to do something special to set up the\n\
402 @file{varasm.c} sections, or if your target has some special sections\n\
403 of its own that you need to create.\n\
405 GCC calls this hook after processing the command line, but before writing\n\
406 any assembly code, and before calling any of the section-returning hooks\n\
411 /* Tell assembler to change to section NAME with attributes FLAGS.
412 If DECL is non-NULL, it is the VAR_DECL or FUNCTION_DECL with
413 which this section is associated. */
416 "Output assembly directives to switch to section @var{name}. The section\n\
417 should have attributes as specified by @var{flags}, which is a bit mask\n\
418 of the @code{SECTION_*} flags defined in @file{output.h}. If @var{decl}\n\
419 is non-NULL, it is the @code{VAR_DECL} or @code{FUNCTION_DECL} with which\n\
420 this section is associated.",
421 void, (const char *name, unsigned int flags, tree decl),
422 default_no_named_section)
424 /* Tell assembler what section attributes to assign this elf section
425 declaration, using their numerical value. */
428 "This hook can be used to encode ELF section flags for which no letter\n\
429 code has been defined in the assembler. It is called by\n\
430 @code{default_asm_named_section} whenever the section flags need to be\n\
431 emitted in the assembler output. If the hook returns true, then the\n\
432 numerical value for ELF section flags should be calculated from\n\
433 @var{flags} and saved in @var{*num}; the value is printed out instead of the\n\
434 normal sequence of letter codes. If the hook is not defined, or if it\n\
435 returns false, then @var{num} is ignored and the traditional letter sequence\n\
437 bool, (unsigned int flags, unsigned int *num),
438 hook_bool_uint_uintp_false)
440 /* Return preferred text (sub)section for function DECL.
441 Main purpose of this function is to separate cold, normal and hot
442 functions. STARTUP is true when function is known to be used only
443 at startup (from static constructors or it is main()).
444 EXIT is true when function is known to be used only at exit
445 (from static destructors).
446 Return NULL if function should go to default text section. */
449 "Return preferred text (sub)section for function @var{decl}.\n\
450 Main purpose of this function is to separate cold, normal and hot\n\
451 functions. @var{startup} is true when function is known to be used only\n\
452 at startup (from static constructors or it is @code{main()}).\n\
453 @var{exit} is true when function is known to be used only at exit\n\
454 (from static destructors).\n\
455 Return NULL if function should go to default text section.",
456 section *, (tree decl, enum node_frequency freq, bool startup, bool exit),
457 default_function_section)
459 /* Output the assembler code for function exit. */
461 (function_switched_text_sections,
462 "Used by the target to emit any assembler directives or additional\
463 labels needed when a function is partitioned between different\
464 sections. Output should be written to @var{file}. The function\
465 decl is available as @var{decl} and the new section is `cold' if\
466 @var{new_is_cold} is @code{true}.",
467 void, (FILE *file, tree decl, bool new_is_cold),
468 default_function_switched_text_sections)
470 /* Return a mask describing how relocations should be treated when
471 selecting sections. Bit 1 should be set if global relocations
472 should be placed in a read-write section; bit 0 should be set if
473 local relocations should be placed in a read-write section. */
476 "Return a mask describing how relocations should be treated when\n\
477 selecting sections. Bit 1 should be set if global relocations\n\
478 should be placed in a read-write section; bit 0 should be set if\n\
479 local relocations should be placed in a read-write section.\n\
481 The default version of this function returns 3 when @option{-fpic}\n\
482 is in effect, and 0 otherwise. The hook is typically redefined\n\
483 when the target cannot support (some kinds of) dynamic relocations\n\
484 in read-only sections even in executables.",
486 default_reloc_rw_mask)
488 /* Return a flag for either generating ADDR_DIF_VEC table
489 or ADDR_VEC table for jumps in case of -fPIC/-fPIE. */
491 (generate_pic_addr_diff_vec,
492 "Return true to generate ADDR_DIF_VEC table\n\
493 or false to generate ADDR_VEC table for jumps in case of -fPIC.\n\
495 The default version of this function returns true if flag_pic\n\
496 equals true and false otherwise",
498 default_generate_pic_addr_diff_vec)
500 /* Return a section for EXP. It may be a DECL or a constant. RELOC
501 is nonzero if runtime relocations must be applied; bit 1 will be
502 set if the runtime relocations require non-local name resolution.
503 ALIGN is the required alignment of the data. */
506 "Return the section into which @var{exp} should be placed. You can\n\
507 assume that @var{exp} is either a @code{VAR_DECL} node or a constant of\n\
508 some sort. @var{reloc} indicates whether the initial value of @var{exp}\n\
509 requires link-time relocations. Bit 0 is set when variable contains\n\
510 local relocations only, while bit 1 is set for global relocations.\n\
511 @var{align} is the constant alignment in bits.\n\
513 The default version of this function takes care of putting read-only\n\
514 variables in @code{readonly_data_section}.\n\
516 See also @var{USE_SELECT_SECTION_FOR_FUNCTIONS}.",
517 section *, (tree exp, int reloc, unsigned HOST_WIDE_INT align),
518 default_select_section)
520 /* Return a section for X. MODE is X's mode and ALIGN is its
521 alignment in bits. */
524 "Return the section into which a constant @var{x}, of mode @var{mode},\n\
525 should be placed. You can assume that @var{x} is some kind of\n\
526 constant in RTL@. The argument @var{mode} is redundant except in the\n\
527 case of a @code{const_int} rtx. @var{align} is the constant alignment\n\
530 The default version of this function takes care of putting symbolic\n\
531 constants in @code{flag_pic} mode in @code{data_section} and everything\n\
532 else in @code{readonly_data_section}.",
533 section *, (machine_mode mode, rtx x, unsigned HOST_WIDE_INT align),
534 default_select_rtx_section)
536 /* Select a unique section name for DECL. RELOC is the same as
537 for SELECT_SECTION. */
540 "Build up a unique section name, expressed as a @code{STRING_CST} node,\n\
541 and assign it to @samp{DECL_SECTION_NAME (@var{decl})}.\n\
542 As with @code{TARGET_ASM_SELECT_SECTION}, @var{reloc} indicates whether\n\
543 the initial value of @var{exp} requires link-time relocations.\n\
545 The default version of this function appends the symbol name to the\n\
546 ELF section name that would normally be used for the symbol. For\n\
547 example, the function @code{foo} would be placed in @code{.text.foo}.\n\
548 Whatever the actual target object format, this is often good enough.",
549 void, (tree decl, int reloc),
550 default_unique_section)
552 /* Return the readonly data section associated with function DECL. */
554 (function_rodata_section,
555 "Return the readonly data section associated with\n\
556 @samp{DECL_SECTION_NAME (@var{decl})}.\n\
557 The default version of this function selects @code{.gnu.linkonce.r.name} if\n\
558 the function's section is @code{.gnu.linkonce.t.name}, @code{.rodata.name}\n\
559 if function is in @code{.text.name}, and the normal readonly-data section\n\
561 section *, (tree decl),
562 default_function_rodata_section)
564 /* Nonnull if the target wants to override the default ".rodata" prefix
565 for mergeable data sections. */
567 (mergeable_rodata_prefix,
568 "Usually, the compiler uses the prefix @code{\".rodata\"} to construct\n\
569 section names for mergeable constant data. Define this macro to override\n\
570 the string if a different section name should be used.",
571 const char *, ".rodata")
573 /* Return the section to be used for transactional memory clone tables. */
575 (tm_clone_table_section,
576 "Return the section that should be used for transactional memory clone\
578 section *, (void), default_clone_table_section)
580 /* Output a constructor for a symbol with a given priority. */
583 "If defined, a function that outputs assembler code to arrange to call\n\
584 the function referenced by @var{symbol} at initialization time.\n\
586 Assume that @var{symbol} is a @code{SYMBOL_REF} for a function taking\n\
587 no arguments and with no return value. If the target supports initialization\n\
588 priorities, @var{priority} is a value between 0 and @code{MAX_INIT_PRIORITY};\n\
589 otherwise it must be @code{DEFAULT_INIT_PRIORITY}.\n\
591 If this macro is not defined by the target, a suitable default will\n\
592 be chosen if (1) the target supports arbitrary section names, (2) the\n\
593 target defines @code{CTORS_SECTION_ASM_OP}, or (3) @code{USE_COLLECT2}\n\
595 void, (rtx symbol, int priority), NULL)
597 /* Output a destructor for a symbol with a given priority. */
600 "This is like @code{TARGET_ASM_CONSTRUCTOR} but used for termination\n\
601 functions rather than initialization functions.",
602 void, (rtx symbol, int priority), NULL)
604 /* Output the assembler code for a thunk function. THUNK_DECL is the
605 declaration for the thunk function itself, FUNCTION is the decl for
606 the target function. DELTA is an immediate constant offset to be
607 added to THIS. If VCALL_OFFSET is nonzero, the word at
608 *(*this + vcall_offset) should be added to THIS. */
611 "A function that outputs the assembler code for a thunk\n\
612 function, used to implement C++ virtual function calls with multiple\n\
613 inheritance. The thunk acts as a wrapper around a virtual function,\n\
614 adjusting the implicit object parameter before handing control off to\n\
615 the real function.\n\
617 First, emit code to add the integer @var{delta} to the location that\n\
618 contains the incoming first argument. Assume that this argument\n\
619 contains a pointer, and is the one used to pass the @code{this} pointer\n\
620 in C++. This is the incoming argument @emph{before} the function prologue,\n\
621 e.g.@: @samp{%o0} on a sparc. The addition must preserve the values of\n\
622 all other incoming arguments.\n\
624 Then, if @var{vcall_offset} is nonzero, an additional adjustment should be\n\
625 made after adding @code{delta}. In particular, if @var{p} is the\n\
626 adjusted pointer, the following adjustment should be made:\n\
629 p += (*((ptrdiff_t **)p))[vcall_offset/sizeof(ptrdiff_t)]\n\
632 After the additions, emit code to jump to @var{function}, which is a\n\
633 @code{FUNCTION_DECL}. This is a direct pure jump, not a call, and does\n\
634 not touch the return address. Hence returning from @var{FUNCTION} will\n\
635 return to whoever called the current @samp{thunk}.\n\
637 The effect must be as if @var{function} had been called directly with\n\
638 the adjusted first argument. This macro is responsible for emitting all\n\
639 of the code for a thunk function; @code{TARGET_ASM_FUNCTION_PROLOGUE}\n\
640 and @code{TARGET_ASM_FUNCTION_EPILOGUE} are not invoked.\n\
642 The @var{thunk_fndecl} is redundant. (@var{delta} and @var{function}\n\
643 have already been extracted from it.) It might possibly be useful on\n\
644 some targets, but probably not.\n\
646 If you do not define this macro, the target-independent code in the C++\n\
647 front end will generate a less efficient heavyweight thunk that calls\n\
648 @var{function} instead of jumping to it. The generic approach does\n\
649 not support varargs.",
650 void, (FILE *file, tree thunk_fndecl, HOST_WIDE_INT delta,
651 HOST_WIDE_INT vcall_offset, tree function),
654 /* Determine whether output_mi_thunk would succeed. */
655 /* ??? Ideally, this hook would not exist, and success or failure
656 would be returned from output_mi_thunk directly. But there's
657 too much undo-able setup involved in invoking output_mi_thunk.
658 Could be fixed by making output_mi_thunk emit rtl instead of
659 text to the output file. */
661 (can_output_mi_thunk,
662 "A function that returns true if TARGET_ASM_OUTPUT_MI_THUNK would be able\n\
663 to output the assembler code for the thunk function specified by the\n\
664 arguments it is passed, and false otherwise. In the latter case, the\n\
665 generic approach will be used by the C++ front end, with the limitations\n\
666 previously exposed.",
667 bool, (const_tree thunk_fndecl, HOST_WIDE_INT delta,
668 HOST_WIDE_INT vcall_offset, const_tree function),
669 hook_bool_const_tree_hwi_hwi_const_tree_false)
671 /* Output any boilerplate text needed at the beginning of a
675 "Output to @code{asm_out_file} any text which the assembler expects to\n\
676 find at the beginning of a file. The default behavior is controlled\n\
677 by two flags, documented below. Unless your target's assembler is\n\
678 quite unusual, if you override the default, you should call\n\
679 @code{default_file_start} at some point in your target hook. This\n\
680 lets other target files rely on these variables.",
684 /* Output any boilerplate text needed at the end of a translation unit. */
687 "Output to @code{asm_out_file} any text which the assembler expects\n\
688 to find at the end of a file. The default is to output nothing.",
692 /* Output any boilerplate text needed at the beginning of an
693 LTO output stream. */
696 "Output to @code{asm_out_file} any text which the assembler expects\n\
697 to find at the start of an LTO section. The default is to output\n\
702 /* Output any boilerplate text needed at the end of an
703 LTO output stream. */
706 "Output to @code{asm_out_file} any text which the assembler expects\n\
707 to find at the end of an LTO section. The default is to output\n\
712 /* Output any boilerplace text needed at the end of a
713 translation unit before debug and unwind info is emitted. */
716 "Output to @code{asm_out_file} any text which is needed before emitting\n\
717 unwind info and debug info at the end of a file. Some targets emit\n\
718 here PIC setup thunks that cannot be emitted at the end of file,\n\
719 because they couldn't have unwind info then. The default is to output\n\
724 /* Output an assembler pseudo-op to declare a library function name
728 "This target hook is a function to output to @var{asm_out_file} an assembler\n\
729 pseudo-op to declare a library function name external. The name of the\n\
730 library function is given by @var{symref}, which is a @code{symbol_ref}.",
732 default_external_libcall)
734 /* Output an assembler directive to mark decl live. This instructs
735 linker to not dead code strip this symbol. */
737 (mark_decl_preserved,
738 "This target hook is a function to output to @var{asm_out_file} an assembler\n\
739 directive to annotate @var{symbol} as used. The Darwin target uses the\n\
740 .no_dead_code_strip directive.",
741 void, (const char *symbol),
742 hook_void_constcharptr)
744 /* Output a record of the command line switches that have been passed. */
746 (record_gcc_switches,
747 "Provides the target with the ability to record the gcc command line\n\
748 switches that have been passed to the compiler, and options that are\n\
749 enabled. The @var{type} argument specifies what is being recorded.\n\
750 It can take the following values:\n\
753 @item SWITCH_TYPE_PASSED\n\
754 @var{text} is a command line switch that has been set by the user.\n\
756 @item SWITCH_TYPE_ENABLED\n\
757 @var{text} is an option which has been enabled. This might be as a\n\
758 direct result of a command line switch, or because it is enabled by\n\
759 default or because it has been enabled as a side effect of a different\n\
760 command line switch. For example, the @option{-O2} switch enables\n\
761 various different individual optimization passes.\n\
763 @item SWITCH_TYPE_DESCRIPTIVE\n\
764 @var{text} is either NULL or some descriptive text which should be\n\
765 ignored. If @var{text} is NULL then it is being used to warn the\n\
766 target hook that either recording is starting or ending. The first\n\
767 time @var{type} is SWITCH_TYPE_DESCRIPTIVE and @var{text} is NULL, the\n\
768 warning is for start up and the second time the warning is for\n\
769 wind down. This feature is to allow the target hook to make any\n\
770 necessary preparations before it starts to record switches and to\n\
771 perform any necessary tidying up after it has finished recording\n\
774 @item SWITCH_TYPE_LINE_START\n\
775 This option can be ignored by this target hook.\n\
777 @item SWITCH_TYPE_LINE_END\n\
778 This option can be ignored by this target hook.\n\
781 The hook's return value must be zero. Other return values may be\n\
782 supported in the future.\n\
784 By default this hook is set to NULL, but an example implementation is\n\
785 provided for ELF based targets. Called @var{elf_record_gcc_switches},\n\
786 it records the switches as ASCII text inside a new, string mergeable\n\
787 section in the assembler output file. The name of the new section is\n\
788 provided by the @code{TARGET_ASM_RECORD_GCC_SWITCHES_SECTION} target\n\
790 int, (print_switch_type type, const char *text),
793 /* The name of the section that the example ELF implementation of
794 record_gcc_switches will use to store the information. Target
795 specific versions of record_gcc_switches may or may not use
798 (record_gcc_switches_section,
799 "This is the name of the section that will be created by the example\n\
800 ELF implementation of the @code{TARGET_ASM_RECORD_GCC_SWITCHES} target\n\
802 const char *, ".GCC.command.line")
804 /* Output the definition of a section anchor. */
807 "Write the assembly code to define section anchor @var{x}, which is a\n\
808 @code{SYMBOL_REF} for which @samp{SYMBOL_REF_ANCHOR_P (@var{x})} is true.\n\
809 The hook is called with the assembly output position set to the beginning\n\
810 of @code{SYMBOL_REF_BLOCK (@var{x})}.\n\
812 If @code{ASM_OUTPUT_DEF} is available, the hook's default definition uses\n\
813 it to define the symbol as @samp{. + SYMBOL_REF_BLOCK_OFFSET (@var{x})}.\n\
814 If @code{ASM_OUTPUT_DEF} is not available, the hook's default definition\n\
815 is @code{NULL}, which disables the use of section anchors altogether.",
817 default_asm_output_anchor)
821 "Output a string based on @var{name}, suitable for the @samp{#ident} \
822 directive, or the equivalent directive or pragma in non-C-family languages. \
823 If this hook is not defined, nothing is output for the @samp{#ident} \
825 void, (const char *name),
826 hook_void_constcharptr)
828 /* Output a DTP-relative reference to a TLS symbol. */
830 (output_dwarf_dtprel,
831 "If defined, this target hook is a function which outputs a DTP-relative\n\
832 reference to the given TLS symbol of the specified size.",
833 void, (FILE *file, int size, rtx x),
836 /* Some target machines need to postscan each insn after it is output. */
838 (final_postscan_insn,
839 "If defined, this target hook is a function which is executed just after the\n\
840 output of assembler code for @var{insn}, to change the mode of the assembler\n\
843 Here the argument @var{opvec} is the vector containing the operands\n\
844 extracted from @var{insn}, and @var{noperands} is the number of\n\
845 elements of the vector which contain meaningful data for this insn.\n\
846 The contents of this vector are what was used to convert the insn\n\
847 template into assembler code, so you can change the assembler mode\n\
848 by checking the contents of the vector.",
849 void, (FILE *file, rtx_insn *insn, rtx *opvec, int noperands),
852 /* Emit the trampoline template. This hook may be NULL. */
854 (trampoline_template,
855 "This hook is called by @code{assemble_trampoline_template} to output,\n\
856 on the stream @var{f}, assembler code for a block of data that contains\n\
857 the constant parts of a trampoline. This code should not include a\n\
858 label---the label is taken care of automatically.\n\
860 If you do not define this hook, it means no template is needed\n\
861 for the target. Do not define this hook on systems where the block move\n\
862 code to copy the trampoline into place would be larger than the code\n\
863 to generate it on the spot.",
868 (output_source_filename,
869 "Output DWARF debugging information which indicates that filename\
870 @var{name} is the current source file to the stdio stream @var{file}.\n\
872 This target hook need not be defined if the standard form of output\
873 for the file format in use is appropriate.",
874 void ,(FILE *file, const char *name),
875 default_asm_output_source_filename)
878 (output_addr_const_extra,
879 "A target hook to recognize @var{rtx} patterns that @code{output_addr_const}\n\
880 can't deal with, and output assembly code to @var{file} corresponding to\n\
881 the pattern @var{x}. This may be used to allow machine-dependent\n\
882 @code{UNSPEC}s to appear within constants.\n\
884 If target hook fails to recognize a pattern, it must return @code{false},\n\
885 so that a standard error message is printed. If it prints an error message\n\
886 itself, by calling, for example, @code{output_operand_lossage}, it may just\n\
887 return @code{true}.",
888 bool, (FILE *file, rtx x),
889 hook_bool_FILEptr_rtx_false)
891 /* ??? The TARGET_PRINT_OPERAND* hooks are part of the asm_out struct,
892 even though that is not reflected in the macro name to override their
895 #define HOOK_PREFIX "TARGET_"
897 /* Emit a machine-specific insn operand. */
898 /* ??? tm.texi only documents the old macro PRINT_OPERAND,
899 not this hook, and uses a different name for the argument FILE. */
903 void, (FILE *file, rtx x, int code),
904 default_print_operand)
906 /* Emit a machine-specific memory address. */
907 /* ??? tm.texi only documents the old macro PRINT_OPERAND_ADDRESS,
908 not this hook, and uses different argument names. */
910 (print_operand_address,
912 void, (FILE *file, machine_mode mode, rtx addr),
913 default_print_operand_address)
915 /* Determine whether CODE is a valid punctuation character for the
916 `print_operand' hook. */
917 /* ??? tm.texi only documents the old macro PRINT_OPERAND_PUNCT_VALID_P,
920 (print_operand_punct_valid_p,
922 bool ,(unsigned char code),
923 default_print_operand_punct_valid_p)
925 /* Given a symbol name, perform same mangling as assemble_name and
926 ASM_OUTPUT_LABELREF, returning result as an IDENTIFIER_NODE. */
928 (mangle_assembler_name,
929 "Given a symbol @var{name}, perform same mangling as @code{varasm.c}'s\
930 @code{assemble_name}, but in memory rather than to a file stream, returning\
931 result as an @code{IDENTIFIER_NODE}. Required for correct LTO symtabs. The\
932 default implementation calls the @code{TARGET_STRIP_NAME_ENCODING} hook and\
933 then prepends the @code{USER_LABEL_PREFIX}, if any.",
934 tree, (const char *name),
935 default_mangle_assembler_name)
937 HOOK_VECTOR_END (asm_out)
939 /* Functions relating to instruction scheduling. All of these
940 default to null pointers, which haifa-sched.c looks for and handles. */
942 #define HOOK_PREFIX "TARGET_SCHED_"
943 HOOK_VECTOR (TARGET_SCHED, sched)
945 /* Given the current cost, COST, of an insn, INSN, calculate and
946 return a new cost based on its relationship to DEP_INSN through
947 the dependence LINK. The default is to make no adjustment. */
950 "This function corrects the value of @var{cost} based on the\n\
951 relationship between @var{insn} and @var{dep_insn} through a\n\
952 dependence of type dep_type, and strength @var{dw}. It should return the new\n\
953 value. The default is to make no adjustment to @var{cost}. This can be\n\
954 used for example to specify to the scheduler using the traditional pipeline\n\
955 description that an output- or anti-dependence does not incur the same cost\n\
956 as a data-dependence. If the scheduler using the automaton based pipeline\n\
957 description, the cost of anti-dependence is zero and the cost of\n\
958 output-dependence is maximum of one and the difference of latency\n\
959 times of the first and the second insns. If these values are not\n\
960 acceptable, you could use the hook to modify them too. See also\n\
961 @pxref{Processor pipeline description}.",
962 int, (rtx_insn *insn, int dep_type1, rtx_insn *dep_insn, int cost,
966 /* Adjust the priority of an insn as you see fit. Returns the new priority. */
969 "This hook adjusts the integer scheduling priority @var{priority} of\n\
970 @var{insn}. It should return the new priority. Increase the priority to\n\
971 execute @var{insn} earlier, reduce the priority to execute @var{insn}\n\
972 later. Do not define this hook if you do not need to adjust the\n\
973 scheduling priorities of insns.",
974 int, (rtx_insn *insn, int priority), NULL)
976 /* Function which returns the maximum number of insns that can be
977 scheduled in the same machine cycle. This must be constant
978 over an entire compilation. The default is 1. */
981 "This hook returns the maximum number of instructions that can ever\n\
982 issue at the same time on the target machine. The default is one.\n\
983 Although the insn scheduler can define itself the possibility of issue\n\
984 an insn on the same cycle, the value can serve as an additional\n\
985 constraint to issue insns on the same simulated processor cycle (see\n\
986 hooks @samp{TARGET_SCHED_REORDER} and @samp{TARGET_SCHED_REORDER2}).\n\
987 This value must be constant over the entire compilation. If you need\n\
988 it to vary depending on what the instructions are, you must use\n\
989 @samp{TARGET_SCHED_VARIABLE_ISSUE}.",
992 /* Calculate how much this insn affects how many more insns we
993 can emit this cycle. Default is they all cost the same. */
996 "This hook is executed by the scheduler after it has scheduled an insn\n\
997 from the ready list. It should return the number of insns which can\n\
998 still be issued in the current cycle. The default is\n\
999 @samp{@w{@var{more} - 1}} for insns other than @code{CLOBBER} and\n\
1000 @code{USE}, which normally are not counted against the issue rate.\n\
1001 You should define this hook if some insns take more machine resources\n\
1002 than others, so that fewer insns can follow them in the same cycle.\n\
1003 @var{file} is either a null pointer, or a stdio stream to write any\n\
1004 debug output to. @var{verbose} is the verbose level provided by\n\
1005 @option{-fsched-verbose-@var{n}}. @var{insn} is the instruction that\n\
1007 int, (FILE *file, int verbose, rtx_insn *insn, int more), NULL)
1009 /* Initialize machine-dependent scheduling code. */
1012 "This hook is executed by the scheduler at the beginning of each block of\n\
1013 instructions that are to be scheduled. @var{file} is either a null\n\
1014 pointer, or a stdio stream to write any debug output to. @var{verbose}\n\
1015 is the verbose level provided by @option{-fsched-verbose-@var{n}}.\n\
1016 @var{max_ready} is the maximum number of insns in the current scheduling\n\
1017 region that can be live at the same time. This can be used to allocate\n\
1018 scratch space if it is needed, e.g.@: by @samp{TARGET_SCHED_REORDER}.",
1019 void, (FILE *file, int verbose, int max_ready), NULL)
1021 /* Finalize machine-dependent scheduling code. */
1024 "This hook is executed by the scheduler at the end of each block of\n\
1025 instructions that are to be scheduled. It can be used to perform\n\
1026 cleanup of any actions done by the other scheduling hooks. @var{file}\n\
1027 is either a null pointer, or a stdio stream to write any debug output\n\
1028 to. @var{verbose} is the verbose level provided by\n\
1029 @option{-fsched-verbose-@var{n}}.",
1030 void, (FILE *file, int verbose), NULL)
1032 /* Initialize machine-dependent function wide scheduling code. */
1035 "This hook is executed by the scheduler after function level initializations.\n\
1036 @var{file} is either a null pointer, or a stdio stream to write any debug output to.\n\
1037 @var{verbose} is the verbose level provided by @option{-fsched-verbose-@var{n}}.\n\
1038 @var{old_max_uid} is the maximum insn uid when scheduling begins.",
1039 void, (FILE *file, int verbose, int old_max_uid), NULL)
1041 /* Finalize machine-dependent function wide scheduling code. */
1044 "This is the cleanup hook corresponding to @code{TARGET_SCHED_INIT_GLOBAL}.\n\
1045 @var{file} is either a null pointer, or a stdio stream to write any debug output to.\n\
1046 @var{verbose} is the verbose level provided by @option{-fsched-verbose-@var{n}}.",
1047 void, (FILE *file, int verbose), NULL)
1049 /* Reorder insns in a machine-dependent fashion, in two different
1050 places. Default does nothing. */
1053 "This hook is executed by the scheduler after it has scheduled the ready\n\
1054 list, to allow the machine description to reorder it (for example to\n\
1055 combine two small instructions together on @samp{VLIW} machines).\n\
1056 @var{file} is either a null pointer, or a stdio stream to write any\n\
1057 debug output to. @var{verbose} is the verbose level provided by\n\
1058 @option{-fsched-verbose-@var{n}}. @var{ready} is a pointer to the ready\n\
1059 list of instructions that are ready to be scheduled. @var{n_readyp} is\n\
1060 a pointer to the number of elements in the ready list. The scheduler\n\
1061 reads the ready list in reverse order, starting with\n\
1062 @var{ready}[@var{*n_readyp} @minus{} 1] and going to @var{ready}[0]. @var{clock}\n\
1063 is the timer tick of the scheduler. You may modify the ready list and\n\
1064 the number of ready insns. The return value is the number of insns that\n\
1065 can issue this cycle; normally this is just @code{issue_rate}. See also\n\
1066 @samp{TARGET_SCHED_REORDER2}.",
1067 int, (FILE *file, int verbose, rtx_insn **ready, int *n_readyp, int clock), NULL)
1071 "Like @samp{TARGET_SCHED_REORDER}, but called at a different time. That\n\
1072 function is called whenever the scheduler starts a new cycle. This one\n\
1073 is called once per iteration over a cycle, immediately after\n\
1074 @samp{TARGET_SCHED_VARIABLE_ISSUE}; it can reorder the ready list and\n\
1075 return the number of insns to be scheduled in the same cycle. Defining\n\
1076 this hook can be useful if there are frequent situations where\n\
1077 scheduling one insn causes other insns to become ready in the same\n\
1078 cycle. These other insns can then be taken into account properly.",
1079 int, (FILE *file, int verbose, rtx_insn **ready, int *n_readyp, int clock), NULL)
1083 "This hook is used to check whether target platform supports macro fusion.",
1087 (macro_fusion_pair_p,
1088 "This hook is used to check whether two insns should be macro fused for\n\
1089 a target microarchitecture. If this hook returns true for the given insn pair\n\
1090 (@var{prev} and @var{curr}), the scheduler will put them into a sched\n\
1091 group, and they will not be scheduled apart. The two insns will be either\n\
1092 two SET insns or a compare and a conditional jump and this hook should\n\
1093 validate any dependencies needed to fuse the two insns together.",
1094 bool, (rtx_insn *prev, rtx_insn *curr), NULL)
1096 /* The following member value is a pointer to a function called
1097 after evaluation forward dependencies of insns in chain given
1098 by two parameter values (head and tail correspondingly). */
1100 (dependencies_evaluation_hook,
1101 "This hook is called after evaluation forward dependencies of insns in\n\
1102 chain given by two parameter values (@var{head} and @var{tail}\n\
1103 correspondingly) but before insns scheduling of the insn chain. For\n\
1104 example, it can be used for better insn classification if it requires\n\
1105 analysis of dependencies. This hook can use backward and forward\n\
1106 dependencies of the insn scheduler because they are already\n\
1108 void, (rtx_insn *head, rtx_insn *tail), NULL)
1110 /* The values of the following four members are pointers to functions
1111 used to simplify the automaton descriptions. dfa_pre_cycle_insn and
1112 dfa_post_cycle_insn give functions returning insns which are used to
1113 change the pipeline hazard recognizer state when the new simulated
1114 processor cycle correspondingly starts and finishes. The function
1115 defined by init_dfa_pre_cycle_insn and init_dfa_post_cycle_insn are
1116 used to initialize the corresponding insns. The default values of
1117 the members result in not changing the automaton state when the
1118 new simulated processor cycle correspondingly starts and finishes. */
1121 (init_dfa_pre_cycle_insn,
1122 "The hook can be used to initialize data used by the previous hook.",
1126 (dfa_pre_cycle_insn,
1127 "The hook returns an RTL insn. The automaton state used in the\n\
1128 pipeline hazard recognizer is changed as if the insn were scheduled\n\
1129 when the new simulated processor cycle starts. Usage of the hook may\n\
1130 simplify the automaton pipeline description for some @acronym{VLIW}\n\
1131 processors. If the hook is defined, it is used only for the automaton\n\
1132 based pipeline description. The default is not to change the state\n\
1133 when the new simulated processor cycle starts.",
1137 (init_dfa_post_cycle_insn,
1138 "The hook is analogous to @samp{TARGET_SCHED_INIT_DFA_PRE_CYCLE_INSN} but\n\
1139 used to initialize data used by the previous hook.",
1143 (dfa_post_cycle_insn,
1144 "The hook is analogous to @samp{TARGET_SCHED_DFA_PRE_CYCLE_INSN} but used\n\
1145 to changed the state as if the insn were scheduled when the new\n\
1146 simulated processor cycle finishes.",
1147 rtx_insn *, (void), NULL)
1149 /* The values of the following two members are pointers to
1150 functions used to simplify the automaton descriptions.
1151 dfa_pre_advance_cycle and dfa_post_advance_cycle are getting called
1152 immediately before and after cycle is advanced. */
1155 (dfa_pre_advance_cycle,
1156 "The hook to notify target that the current simulated cycle is about to finish.\n\
1157 The hook is analogous to @samp{TARGET_SCHED_DFA_PRE_CYCLE_INSN} but used\n\
1158 to change the state in more complicated situations - e.g., when advancing\n\
1159 state on a single insn is not enough.",
1163 (dfa_post_advance_cycle,
1164 "The hook to notify target that new simulated cycle has just started.\n\
1165 The hook is analogous to @samp{TARGET_SCHED_DFA_POST_CYCLE_INSN} but used\n\
1166 to change the state in more complicated situations - e.g., when advancing\n\
1167 state on a single insn is not enough.",
1170 /* The following member value is a pointer to a function returning value
1171 which defines how many insns in queue `ready' will we try for
1172 multi-pass scheduling. If the member value is nonzero and the
1173 function returns positive value, the DFA based scheduler will make
1174 multi-pass scheduling for the first cycle. In other words, we will
1175 try to choose ready insn which permits to start maximum number of
1176 insns on the same cycle. */
1178 (first_cycle_multipass_dfa_lookahead,
1179 "This hook controls better choosing an insn from the ready insn queue\n\
1180 for the @acronym{DFA}-based insn scheduler. Usually the scheduler\n\
1181 chooses the first insn from the queue. If the hook returns a positive\n\
1182 value, an additional scheduler code tries all permutations of\n\
1183 @samp{TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD ()}\n\
1184 subsequent ready insns to choose an insn whose issue will result in\n\
1185 maximal number of issued insns on the same cycle. For the\n\
1186 @acronym{VLIW} processor, the code could actually solve the problem of\n\
1187 packing simple insns into the @acronym{VLIW} insn. Of course, if the\n\
1188 rules of @acronym{VLIW} packing are described in the automaton.\n\
1190 This code also could be used for superscalar @acronym{RISC}\n\
1191 processors. Let us consider a superscalar @acronym{RISC} processor\n\
1192 with 3 pipelines. Some insns can be executed in pipelines @var{A} or\n\
1193 @var{B}, some insns can be executed only in pipelines @var{B} or\n\
1194 @var{C}, and one insn can be executed in pipeline @var{B}. The\n\
1195 processor may issue the 1st insn into @var{A} and the 2nd one into\n\
1196 @var{B}. In this case, the 3rd insn will wait for freeing @var{B}\n\
1197 until the next cycle. If the scheduler issues the 3rd insn the first,\n\
1198 the processor could issue all 3 insns per cycle.\n\
1200 Actually this code demonstrates advantages of the automaton based\n\
1201 pipeline hazard recognizer. We try quickly and easy many insn\n\
1202 schedules to choose the best one.\n\
1204 The default is no multipass scheduling.",
1207 /* The following member value is pointer to a function controlling
1208 what insns from the ready insn queue will be considered for the
1209 multipass insn scheduling. If the hook returns zero for insn
1210 passed as the parameter, the insn will be not chosen to be issued. */
1212 (first_cycle_multipass_dfa_lookahead_guard,
1214 This hook controls what insns from the ready insn queue will be\n\
1215 considered for the multipass insn scheduling. If the hook returns\n\
1216 zero for @var{insn}, the insn will be considered in multipass scheduling.\n\
1217 Positive return values will remove @var{insn} from consideration on\n\
1218 the current round of multipass scheduling.\n\
1219 Negative return values will remove @var{insn} from consideration for given\n\
1220 number of cycles.\n\
1221 Backends should be careful about returning non-zero for highest priority\n\
1222 instruction at position 0 in the ready list. @var{ready_index} is passed\n\
1223 to allow backends make correct judgements.\n\
1225 The default is that any ready insns can be chosen to be issued.",
1226 int, (rtx_insn *insn, int ready_index), NULL)
1228 /* This hook prepares the target for a new round of multipass
1230 DATA is a pointer to target-specific data used for multipass scheduling.
1231 READY_TRY and N_READY represent the current state of search in the
1232 optimization space. The target can filter out instructions that
1233 should not be tried during current round by setting corresponding
1234 elements in READY_TRY to non-zero.
1235 FIRST_CYCLE_INSN_P is true if this is the first round of multipass
1236 scheduling on current cycle. */
1238 (first_cycle_multipass_begin,
1239 "This hook prepares the target backend for a new round of multipass\n\
1241 void, (void *data, signed char *ready_try, int n_ready, bool first_cycle_insn_p),
1244 /* This hook is called when multipass scheduling evaluates instruction INSN.
1245 DATA is a pointer to target-specific data that can be used to record effects
1246 of INSN on CPU that are not 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.
1251 INSN is the instruction being evaluated.
1252 PREV_DATA is a pointer to target-specific data corresponding
1253 to a state before issuing INSN. */
1255 (first_cycle_multipass_issue,
1256 "This hook is called when multipass scheduling evaluates instruction INSN.",
1257 void, (void *data, signed char *ready_try, int n_ready, rtx_insn *insn,
1258 const void *prev_data), NULL)
1260 /* This hook is called when multipass scheduling backtracks from evaluation of
1261 instruction corresponding to DATA.
1262 DATA is a pointer to target-specific data that stores the effects
1263 of instruction from which the algorithm backtracks on CPU that are not
1265 READY_TRY and N_READY represent the current state of search in the
1266 optimization space. The target can filter out instructions that
1267 should not be tried after issuing INSN by setting corresponding
1268 elements in READY_TRY to non-zero. */
1270 (first_cycle_multipass_backtrack,
1271 "This is called when multipass scheduling backtracks from evaluation of\n\
1273 void, (const void *data, signed char *ready_try, int n_ready), NULL)
1275 /* This hook notifies the target about the result of the concluded current
1276 round of multipass scheduling.
1278 If DATA is non-NULL it points to target-specific data used for multipass
1279 scheduling which corresponds to instruction at the start of the chain of
1280 the winning solution. DATA is NULL when multipass scheduling cannot find
1281 a good enough solution on current cycle and decides to retry later,
1282 usually after advancing the cycle count. */
1284 (first_cycle_multipass_end,
1285 "This hook notifies the target about the result of the concluded current\n\
1286 round of multipass scheduling.",
1287 void, (const void *data), NULL)
1289 /* This hook is called to initialize target-specific data for multipass
1290 scheduling after it has been allocated.
1291 DATA is a pointer to target-specific data that stores the effects
1292 of instruction from which the algorithm backtracks on CPU that are not
1293 described in DFA. */
1295 (first_cycle_multipass_init,
1296 "This hook initializes target-specific data used in multipass scheduling.",
1297 void, (void *data), NULL)
1299 /* This hook is called to finalize target-specific data for multipass
1300 scheduling before it is deallocated.
1301 DATA is a pointer to target-specific data that stores the effects
1302 of instruction from which the algorithm backtracks on CPU that are not
1303 described in DFA. */
1305 (first_cycle_multipass_fini,
1306 "This hook finalizes target-specific data used in multipass scheduling.",
1307 void, (void *data), NULL)
1309 /* The following member value is pointer to a function called by
1310 the insn scheduler before issuing insn passed as the third
1311 parameter on given cycle. If the hook returns nonzero, the
1312 insn is not issued on given processors cycle. Instead of that,
1313 the processor cycle is advanced. If the value passed through
1314 the last parameter is zero, the insn ready queue is not sorted
1315 on the new cycle start as usually. The first parameter passes
1316 file for debugging output. The second one passes the scheduler
1317 verbose level of the debugging output. The forth and the fifth
1318 parameter values are correspondingly processor cycle on which
1319 the previous insn has been issued and the current processor cycle. */
1322 "This hook is called by the insn scheduler before issuing @var{insn}\n\
1323 on cycle @var{clock}. If the hook returns nonzero,\n\
1324 @var{insn} is not issued on this processor cycle. Instead,\n\
1325 the processor cycle is advanced. If *@var{sort_p}\n\
1326 is zero, the insn ready queue is not sorted on the new cycle\n\
1327 start as usually. @var{dump} and @var{verbose} specify the file and\n\
1328 verbosity level to use for debugging output.\n\
1329 @var{last_clock} and @var{clock} are, respectively, the\n\
1330 processor cycle on which the previous insn has been issued,\n\
1331 and the current processor cycle.",
1332 int, (FILE *dump, int verbose, rtx_insn *insn, int last_clock,
1333 int clock, int *sort_p),
1336 /* The following member value is a pointer to a function called by the
1337 insn scheduler. It should return true if there exists a dependence
1338 which is considered costly by the target, between the insn
1339 DEP_PRO (&_DEP), and the insn DEP_CON (&_DEP). The first parameter is
1340 the dep that represents the dependence between the two insns. The
1341 second argument is the cost of the dependence as estimated by
1342 the scheduler. The last argument is the distance in cycles
1343 between the already scheduled insn (first parameter) and the
1344 second insn (second parameter). */
1346 (is_costly_dependence,
1347 "This hook is used to define which dependences are considered costly by\n\
1348 the target, so costly that it is not advisable to schedule the insns that\n\
1349 are involved in the dependence too close to one another. The parameters\n\
1350 to this hook are as follows: The first parameter @var{_dep} is the dependence\n\
1351 being evaluated. The second parameter @var{cost} is the cost of the\n\
1352 dependence as estimated by the scheduler, and the third\n\
1353 parameter @var{distance} is the distance in cycles between the two insns.\n\
1354 The hook returns @code{true} if considering the distance between the two\n\
1355 insns the dependence between them is considered costly by the target,\n\
1356 and @code{false} otherwise.\n\
1358 Defining this hook can be useful in multiple-issue out-of-order machines,\n\
1359 where (a) it's practically hopeless to predict the actual data/resource\n\
1360 delays, however: (b) there's a better chance to predict the actual grouping\n\
1361 that will be formed, and (c) correctly emulating the grouping can be very\n\
1362 important. In such targets one may want to allow issuing dependent insns\n\
1363 closer to one another---i.e., closer than the dependence distance; however,\n\
1364 not in cases of ``costly dependences'', which this hooks allows to define.",
1365 bool, (struct _dep *_dep, int cost, int distance), NULL)
1367 /* The following member value is a pointer to a function called
1368 by the insn scheduler. This hook is called to notify the backend
1369 that new instructions were emitted. */
1372 "This hook is called by the insn scheduler after emitting a new instruction to\n\
1373 the instruction stream. The hook notifies a target backend to extend its\n\
1374 per instruction data structures.",
1377 /* Next 5 functions are for multi-point scheduling. */
1379 /* Allocate memory for scheduler context. */
1381 (alloc_sched_context,
1382 "Return a pointer to a store large enough to hold target scheduling context.",
1383 void *, (void), NULL)
1385 /* Fills the context from the local machine scheduler context. */
1387 (init_sched_context,
1388 "Initialize store pointed to by @var{tc} to hold target scheduling context.\n\
1389 It @var{clean_p} is true then initialize @var{tc} as if scheduler is at the\n\
1390 beginning of the block. Otherwise, copy the current context into @var{tc}.",
1391 void, (void *tc, bool clean_p), NULL)
1393 /* Sets local machine scheduler context to a saved value. */
1396 "Copy target scheduling context pointed to by @var{tc} to the current context.",
1397 void, (void *tc), NULL)
1399 /* Clears a scheduler context so it becomes like after init. */
1401 (clear_sched_context,
1402 "Deallocate internal data in target scheduling context pointed to by @var{tc}.",
1403 void, (void *tc), NULL)
1405 /* Frees the scheduler context. */
1407 (free_sched_context,
1408 "Deallocate a store for target scheduling context pointed to by @var{tc}.",
1409 void, (void *tc), NULL)
1411 /* The following member value is a pointer to a function called
1412 by the insn scheduler.
1413 The first parameter is an instruction, the second parameter is the type
1414 of the requested speculation, and the third parameter is a pointer to the
1415 speculative pattern of the corresponding type (set if return value == 1).
1417 -1, if there is no pattern, that will satisfy the requested speculation type,
1418 0, if current pattern satisfies the requested speculation type,
1419 1, if pattern of the instruction should be changed to the newly
1423 "This hook is called by the insn scheduler when @var{insn} has only\n\
1424 speculative dependencies and therefore can be scheduled speculatively.\n\
1425 The hook is used to check if the pattern of @var{insn} has a speculative\n\
1426 version and, in case of successful check, to generate that speculative\n\
1427 pattern. The hook should return 1, if the instruction has a speculative form,\n\
1428 or @minus{}1, if it doesn't. @var{request} describes the type of requested\n\
1429 speculation. If the return value equals 1 then @var{new_pat} is assigned\n\
1430 the generated speculative pattern.",
1431 int, (rtx_insn *insn, unsigned int dep_status, rtx *new_pat), NULL)
1433 /* The following member value is a pointer to a function called
1434 by the insn scheduler. It should return true if the check instruction
1435 passed as the parameter needs a recovery block. */
1438 "This hook is called by the insn scheduler during generation of recovery code\n\
1439 for @var{insn}. It should return @code{true}, if the corresponding check\n\
1440 instruction should branch to recovery code, or @code{false} otherwise.",
1441 bool, (unsigned int dep_status), NULL)
1443 /* The following member value is a pointer to a function called
1444 by the insn scheduler. It should return a pattern for the check
1446 The first parameter is a speculative instruction, the second parameter
1447 is the label of the corresponding recovery block (or null, if it is a
1448 simple check). The third parameter is the kind of speculation that
1449 is being performed. */
1452 "This hook is called by the insn scheduler to generate a pattern for recovery\n\
1453 check instruction. If @var{mutate_p} is zero, then @var{insn} is a\n\
1454 speculative instruction for which the check should be generated.\n\
1455 @var{label} is either a label of a basic block, where recovery code should\n\
1456 be emitted, or a null pointer, when requested check doesn't branch to\n\
1457 recovery code (a simple check). If @var{mutate_p} is nonzero, then\n\
1458 a pattern for a branchy check corresponding to a simple check denoted by\n\
1459 @var{insn} should be generated. In this case @var{label} can't be null.",
1460 rtx, (rtx_insn *insn, rtx_insn *label, unsigned int ds), NULL)
1462 /* The following member value is a pointer to a function that provides
1463 information about the speculation capabilities of the target.
1464 The parameter is a pointer to spec_info variable. */
1467 "This hook is used by the insn scheduler to find out what features should be\n\
1469 The structure *@var{spec_info} should be filled in by the target.\n\
1470 The structure describes speculation types that can be used in the scheduler.",
1471 void, (struct spec_info_def *spec_info), NULL)
1475 "Return speculation types of instruction @var{insn}.",
1476 unsigned int, (rtx_insn *insn), NULL)
1479 (get_insn_checked_ds,
1480 "Return speculation types that are checked for instruction @var{insn}",
1481 unsigned int, (rtx_insn *insn), NULL)
1484 (can_speculate_insn,
1485 "Some instructions should never be speculated by the schedulers, usually\n\
1486 because the instruction is too expensive to get this wrong. Often such\n\
1487 instructions have long latency, and often they are not fully modeled in the\n\
1488 pipeline descriptions. This hook should return @code{false} if @var{insn}\n\
1489 should not be speculated.",
1490 bool, (rtx_insn *insn), hook_bool_rtx_insn_true)
1494 "Return bool if rtx scanning should just skip current layer and\
1495 advance to the inner rtxes.",
1496 bool, (const_rtx x), NULL)
1498 /* The following member value is a pointer to a function that provides
1499 information about the target resource-based lower bound which is
1500 used by the swing modulo scheduler. The parameter is a pointer
1504 "This hook is called by the swing modulo scheduler to calculate a\n\
1505 resource-based lower bound which is based on the resources available in\n\
1506 the machine and the resources required by each instruction. The target\n\
1507 backend can use @var{g} to calculate such bound. A very simple lower\n\
1508 bound will be used in case this hook is not implemented: the total number\n\
1509 of instructions divided by the issue rate.",
1510 int, (struct ddg *g), NULL)
1512 /* The following member value is a function that initializes dispatch
1513 schedling and adds instructions to dispatch window according to its
1517 "This hook is called by Haifa Scheduler. It performs the operation specified\n\
1518 in its second parameter.",
1519 void, (rtx_insn *insn, int x),
1520 hook_void_rtx_insn_int)
1522 /* The following member value is a a function that returns true is
1523 dispatch schedling is supported in hardware and condition passed
1524 as the second parameter is true. */
1527 "This hook is called by Haifa Scheduler. It returns true if dispatch scheduling\n\
1528 is supported in hardware and the condition specified in the parameter is true.",
1529 bool, (rtx_insn *insn, int x),
1530 hook_bool_rtx_insn_int_false)
1534 "True if the processor has an exposed pipeline, which means that not just\n\
1535 the order of instructions is important for correctness when scheduling, but\n\
1536 also the latencies of operations.",
1539 /* The following member value is a function that returns number
1540 of operations reassociator should try to put in parallel for
1541 statements of the given type. By default 1 is used. */
1543 (reassociation_width,
1544 "This hook is called by tree reassociator to determine a level of\n\
1545 parallelism required in output calculations chain.",
1546 int, (unsigned int opc, machine_mode mode),
1547 hook_int_uint_mode_1)
1549 /* The following member value is a function that returns priority for
1550 fusion of each instruction via pointer parameters. */
1553 "This hook is called by scheduling fusion pass. It calculates fusion\n\
1554 priorities for each instruction passed in by parameter. The priorities\n\
1555 are returned via pointer parameters.\n\
1557 @var{insn} is the instruction whose priorities need to be calculated.\n\
1558 @var{max_pri} is the maximum priority can be returned in any cases.\n\
1559 @var{fusion_pri} is the pointer parameter through which @var{insn}'s\n\
1560 fusion priority should be calculated and returned.\n\
1561 @var{pri} is the pointer parameter through which @var{insn}'s priority\n\
1562 should be calculated and returned.\n\
1564 Same @var{fusion_pri} should be returned for instructions which should\n\
1565 be scheduled together. Different @var{pri} should be returned for\n\
1566 instructions with same @var{fusion_pri}. @var{fusion_pri} is the major\n\
1567 sort key, @var{pri} is the minor sort key. All instructions will be\n\
1568 scheduled according to the two priorities. All priorities calculated\n\
1569 should be between 0 (exclusive) and @var{max_pri} (inclusive). To avoid\n\
1570 false dependencies, @var{fusion_pri} of instructions which need to be\n\
1571 scheduled together should be smaller than @var{fusion_pri} of irrelevant\n\
1574 Given below example:\n\
1583 ldr r16, [r2, 12]\n\
1585 @end smallexample\n\
1587 On targets like ARM/AArch64, the two pairs of consecutive loads should be\n\
1588 merged. Since peephole2 pass can't help in this case unless consecutive\n\
1589 loads are actually next to each other in instruction flow. That's where\n\
1590 this scheduling fusion pass works. This hook calculates priority for each\n\
1591 instruction based on its fustion type, like:\n\
1594 ldr r10, [r1, 4] ; fusion_pri=99, pri=96\n\
1595 add r4, r4, r10 ; fusion_pri=100, pri=100\n\
1596 ldr r15, [r2, 8] ; fusion_pri=98, pri=92\n\
1597 sub r5, r5, r15 ; fusion_pri=100, pri=100\n\
1598 ldr r11, [r1, 0] ; fusion_pri=99, pri=100\n\
1599 add r4, r4, r11 ; fusion_pri=100, pri=100\n\
1600 ldr r16, [r2, 12] ; fusion_pri=98, pri=88\n\
1601 sub r5, r5, r16 ; fusion_pri=100, pri=100\n\
1602 @end smallexample\n\
1604 Scheduling fusion pass then sorts all ready to issue instructions according\n\
1605 to the priorities. As a result, instructions of same fusion type will be\n\
1606 pushed together in instruction flow, like:\n\
1612 ldr r16, [r2, 12]\n\
1617 @end smallexample\n\
1619 Now peephole2 pass can simply merge the two pairs of loads.\n\
1621 Since scheduling fusion pass relies on peephole2 to do real fusion\n\
1622 work, it is only enabled by default when peephole2 is in effect.\n\
1624 This is firstly introduced on ARM/AArch64 targets, please refer to\n\
1625 the hook implementation for how different fusion types are supported.",
1626 void, (rtx_insn *insn, int max_pri, int *fusion_pri, int *pri), NULL)
1628 HOOK_VECTOR_END (sched)
1630 /* Functions relating to OpenMP SIMD and __attribute__((simd)) clones. */
1632 #define HOOK_PREFIX "TARGET_SIMD_CLONE_"
1633 HOOK_VECTOR (TARGET_SIMD_CLONE, simd_clone)
1636 (compute_vecsize_and_simdlen,
1637 "This hook should set @var{vecsize_mangle}, @var{vecsize_int}, @var{vecsize_float}\n\
1638 fields in @var{simd_clone} structure pointed by @var{clone_info} argument and also\n\
1639 @var{simdlen} field if it was previously 0.\n\
1640 The hook should return 0 if SIMD clones shouldn't be emitted,\n\
1641 or number of @var{vecsize_mangle} variants that should be emitted.",
1642 int, (struct cgraph_node *, struct cgraph_simd_clone *, tree, int), NULL)
1646 "This hook should add implicit @code{attribute(target(\"...\"))} attribute\n\
1647 to SIMD clone @var{node} if needed.",
1648 void, (struct cgraph_node *), NULL)
1652 "This hook should return -1 if SIMD clone @var{node} shouldn't be used\n\
1653 in vectorized loops in current function, or non-negative number if it is\n\
1654 usable. In that case, the smaller the number is, the more desirable it is\n\
1656 int, (struct cgraph_node *), NULL)
1658 HOOK_VECTOR_END (simd_clone)
1660 /* Functions relating to OpenMP SIMT vectorization transform. */
1662 #define HOOK_PREFIX "TARGET_SIMT_"
1663 HOOK_VECTOR (TARGET_SIMT, simt)
1667 "Return number of threads in SIMT thread group on the target.",
1670 HOOK_VECTOR_END (simt)
1672 /* Functions relating to OpenMP. */
1674 #define HOOK_PREFIX "TARGET_OMP_"
1675 HOOK_VECTOR (TARGET_OMP, omp)
1678 (device_kind_arch_isa,
1679 "Return 1 if @var{trait} @var{name} is present in the OpenMP context's\n\
1680 device trait set, return 0 if not present in any OpenMP context in the\n\
1681 whole translation unit, or -1 if not present in the current OpenMP context\n\
1682 but might be present in another OpenMP context in the same TU.",
1683 int, (enum omp_device_kind_arch_isa trait, const char *name), NULL)
1685 HOOK_VECTOR_END (omp)
1687 /* Functions relating to openacc. */
1689 #define HOOK_PREFIX "TARGET_GOACC_"
1690 HOOK_VECTOR (TARGET_GOACC, goacc)
1694 "This hook should check the launch dimensions provided for an OpenACC\n\
1695 compute region, or routine. Defaulted values are represented as -1\n\
1696 and non-constant values as 0. The @var{fn_level} is negative for the\n\
1697 function corresponding to the compute region. For a routine is is the\n\
1698 outermost level at which partitioned execution may be spawned. The hook\n\
1699 should verify non-default values. If DECL is NULL, global defaults\n\
1700 are being validated and unspecified defaults should be filled in.\n\
1701 Diagnostics should be issued as appropriate. Return\n\
1702 true, if changes have been made. You must override this hook to\n\
1703 provide dimensions larger than 1.",
1704 bool, (tree decl, int *dims, int fn_level, unsigned used),
1705 default_goacc_validate_dims)
1709 "This hook should return the maximum size of a particular dimension,\n\
1710 or zero if unbounded.",
1712 default_goacc_dim_limit)
1716 "This hook can be used to convert IFN_GOACC_FORK and IFN_GOACC_JOIN\n\
1717 function calls to target-specific gimple, or indicate whether they\n\
1718 should be retained. It is executed during the oacc_device_lower pass.\n\
1719 It should return true, if the call should be retained. It should\n\
1720 return false, if it is to be deleted (either because target-specific\n\
1721 gimple has been inserted before it, or there is no need for it).\n\
1722 The default hook returns false, if there are no RTL expanders for them.",
1723 bool, (gcall *call, const int *dims, bool is_fork),
1724 default_goacc_fork_join)
1728 "This hook is used by the oacc_transform pass to expand calls to the\n\
1729 @var{GOACC_REDUCTION} internal function, into a sequence of gimple\n\
1730 instructions. @var{call} is gimple statement containing the call to\n\
1731 the function. This hook removes statement @var{call} after the\n\
1732 expanded sequence has been inserted. This hook is also responsible\n\
1733 for allocating any storage for reductions when necessary.",
1734 void, (gcall *call),
1735 default_goacc_reduction)
1737 HOOK_VECTOR_END (goacc)
1739 /* Functions relating to vectorization. */
1741 #define HOOK_PREFIX "TARGET_VECTORIZE_"
1742 HOOK_VECTOR (TARGET_VECTORIZE, vectorize)
1744 /* The following member value is a pointer to a function called
1745 by the vectorizer, and return the decl of the target builtin
1748 (builtin_mask_for_load,
1749 "This hook should return the DECL of a function @var{f} that given an\n\
1750 address @var{addr} as an argument returns a mask @var{m} that can be\n\
1751 used to extract from two vectors the relevant data that resides in\n\
1752 @var{addr} in case @var{addr} is not properly aligned.\n\
1754 The autovectorizer, when vectorizing a load operation from an address\n\
1755 @var{addr} that may be unaligned, will generate two vector loads from\n\
1756 the two aligned addresses around @var{addr}. It then generates a\n\
1757 @code{REALIGN_LOAD} operation to extract the relevant data from the\n\
1758 two loaded vectors. The first two arguments to @code{REALIGN_LOAD},\n\
1759 @var{v1} and @var{v2}, are the two vectors, each of size @var{VS}, and\n\
1760 the third argument, @var{OFF}, defines how the data will be extracted\n\
1761 from these two vectors: if @var{OFF} is 0, then the returned vector is\n\
1762 @var{v2}; otherwise, the returned vector is composed from the last\n\
1763 @var{VS}-@var{OFF} elements of @var{v1} concatenated to the first\n\
1764 @var{OFF} elements of @var{v2}.\n\
1766 If this hook is defined, the autovectorizer will generate a call\n\
1767 to @var{f} (using the DECL tree that this hook returns) and will\n\
1768 use the return value of @var{f} as the argument @var{OFF} to\n\
1769 @code{REALIGN_LOAD}. Therefore, the mask @var{m} returned by @var{f}\n\
1770 should comply with the semantics expected by @code{REALIGN_LOAD}\n\
1772 If this hook is not defined, then @var{addr} will be used as\n\
1773 the argument @var{OFF} to @code{REALIGN_LOAD}, in which case the low\n\
1774 log2(@var{VS}) @minus{} 1 bits of @var{addr} will be considered.",
1777 /* Returns a built-in function that realizes the vectorized version of
1778 a target-independent function, or NULL_TREE if not available. */
1780 (builtin_vectorized_function,
1781 "This hook should return the decl of a function that implements the\n\
1782 vectorized variant of the function with the @code{combined_fn} code\n\
1783 @var{code} or @code{NULL_TREE} if such a function is not available.\n\
1784 The return type of the vectorized function shall be of vector type\n\
1785 @var{vec_type_out} and the argument types should be @var{vec_type_in}.",
1786 tree, (unsigned code, tree vec_type_out, tree vec_type_in),
1787 default_builtin_vectorized_function)
1789 /* Returns a built-in function that realizes the vectorized version of
1790 a target-specific function, or NULL_TREE if not available. */
1792 (builtin_md_vectorized_function,
1793 "This hook should return the decl of a function that implements the\n\
1794 vectorized variant of target built-in function @code{fndecl}. The\n\
1795 return type of the vectorized function shall be of vector type\n\
1796 @var{vec_type_out} and the argument types should be @var{vec_type_in}.",
1797 tree, (tree fndecl, tree vec_type_out, tree vec_type_in),
1798 default_builtin_md_vectorized_function)
1800 /* Cost of different vector/scalar statements in vectorization cost
1801 model. In case of misaligned vector loads and stores the cost depends
1802 on the data type and misalignment value. */
1804 (builtin_vectorization_cost,
1805 "Returns cost of different scalar or vector statements for vectorization cost model.\n\
1806 For vector memory operations the cost may depend on type (@var{vectype}) and\n\
1807 misalignment value (@var{misalign}).",
1808 int, (enum vect_cost_for_stmt type_of_cost, tree vectype, int misalign),
1809 default_builtin_vectorization_cost)
1812 (preferred_vector_alignment,
1813 "This hook returns the preferred alignment in bits for accesses to\n\
1814 vectors of type @var{type} in vectorized code. This might be less than\n\
1815 or greater than the ABI-defined value returned by\n\
1816 @code{TARGET_VECTOR_ALIGNMENT}. It can be equal to the alignment of\n\
1817 a single element, in which case the vectorizer will not try to optimize\n\
1820 The default hook returns @code{TYPE_ALIGN (@var{type})}, which is\n\
1821 correct for most targets.",
1822 poly_uint64, (const_tree type),
1823 default_preferred_vector_alignment)
1825 /* Return true if vector alignment is reachable (by peeling N
1826 iterations) for the given scalar type. */
1828 (vector_alignment_reachable,
1829 "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.",
1830 bool, (const_tree type, bool is_packed),
1831 default_builtin_vector_alignment_reachable)
1835 "This hook is used to test whether the target can permute up to two\n\
1836 vectors of mode @var{mode} using the permutation vector @code{sel}, and\n\
1837 also to emit such a permutation. In the former case @var{in0}, @var{in1}\n\
1838 and @var{out} are all null. In the latter case @var{in0} and @var{in1} are\n\
1839 the source vectors and @var{out} is the destination vector; all three are\n\
1840 registers of mode @var{mode}. @var{in1} is the same as @var{in0} if\n\
1841 @var{sel} describes a permutation on one vector instead of two.\n\
1843 Return true if the operation is possible, emitting instructions for it\n\
1844 if rtxes are provided.\n\
1846 @cindex @code{vec_perm@var{m}} instruction pattern\n\
1847 If the hook returns false for a mode with multibyte elements, GCC will\n\
1848 try the equivalent byte operation. If that also fails, it will try forcing\n\
1849 the selector into a register and using the @var{vec_perm@var{mode}}\n\
1850 instruction pattern. There is no need for the hook to handle these two\n\
1851 implementation approaches itself.",
1852 bool, (machine_mode mode, rtx output, rtx in0, rtx in1,
1853 const vec_perm_indices &sel),
1856 /* Return true if the target supports misaligned store/load of a
1857 specific factor denoted in the third parameter. The last parameter
1858 is true if the access is defined in a packed struct. */
1860 (support_vector_misalignment,
1861 "This hook should return true if the target supports misaligned vector\n\
1862 store/load of a specific factor denoted in the @var{misalignment}\n\
1863 parameter. The vector store/load should be of machine mode @var{mode} and\n\
1864 the elements in the vectors should be of type @var{type}. @var{is_packed}\n\
1865 parameter is true if the memory access is defined in a packed struct.",
1867 (machine_mode mode, const_tree type, int misalignment, bool is_packed),
1868 default_builtin_support_vector_misalignment)
1870 /* Returns the preferred mode for SIMD operations for the specified
1873 (preferred_simd_mode,
1874 "This hook should return the preferred mode for vectorizing scalar\n\
1875 mode @var{mode}. The default is\n\
1876 equal to @code{word_mode}, because the vectorizer can do some\n\
1877 transformations even in absence of specialized @acronym{SIMD} hardware.",
1880 default_preferred_simd_mode)
1882 /* Returns the preferred mode for splitting SIMD reductions to. */
1885 "This hook should return the preferred mode to split the final reduction\n\
1886 step on @var{mode} to. The reduction is then carried out reducing upper\n\
1887 against lower halves of vectors recursively until the specified mode is\n\
1888 reached. The default is @var{mode} which means no splitting.",
1891 default_split_reduction)
1893 /* Returns a mask of vector sizes to iterate over when auto-vectorizing
1894 after processing the preferred one derived from preferred_simd_mode. */
1896 (autovectorize_vector_modes,
1897 "If using the mode returned by @code{TARGET_VECTORIZE_PREFERRED_SIMD_MODE}\n\
1898 is not the only approach worth considering, this hook should add one mode to\n\
1899 @var{modes} for each useful alternative approach. These modes are then\n\
1900 passed to @code{TARGET_VECTORIZE_RELATED_MODE} to obtain the vector mode\n\
1901 for a given element mode.\n\
1903 The modes returned in @var{modes} should use the smallest element mode\n\
1904 possible for the vectorization approach that they represent, preferring\n\
1905 integer modes over floating-poing modes in the event of a tie. The first\n\
1906 mode should be the @code{TARGET_VECTORIZE_PREFERRED_SIMD_MODE} for its\n\
1909 If @var{all} is true, add suitable vector modes even when they are generally\n\
1910 not expected to be worthwhile.\n\
1912 The hook returns a bitmask of flags that control how the modes in\n\
1913 @var{modes} are used. The flags are:\n\
1915 @item VECT_COMPARE_COSTS\n\
1916 Tells the loop vectorizer to try all the provided modes and pick the one\n\
1917 with the lowest cost. By default the vectorizer will choose the first\n\
1921 The hook does not need to do anything if the vector returned by\n\
1922 @code{TARGET_VECTORIZE_PREFERRED_SIMD_MODE} is the only one relevant\n\
1923 for autovectorization. The default implementation adds no modes and\n\
1926 (vector_modes *modes, bool all),
1927 default_autovectorize_vector_modes)
1931 "If a piece of code is using vector mode @var{vector_mode} and also wants\n\
1932 to operate on elements of mode @var{element_mode}, return the vector mode\n\
1933 it should use for those elements. If @var{nunits} is nonzero, ensure that\n\
1934 the mode has exactly @var{nunits} elements, otherwise pick whichever vector\n\
1935 size pairs the most naturally with @var{vector_mode}. Return an empty\n\
1936 @code{opt_machine_mode} if there is no supported vector mode with the\n\
1937 required properties.\n\
1939 There is no prescribed way of handling the case in which @var{nunits}\n\
1940 is zero. One common choice is to pick a vector mode with the same size\n\
1941 as @var{vector_mode}; this is the natural choice if the target has a\n\
1942 fixed vector size. Another option is to choose a vector mode with the\n\
1943 same number of elements as @var{vector_mode}; this is the natural choice\n\
1944 if the target has a fixed number of elements. Alternatively, the hook\n\
1945 might choose a middle ground, such as trying to keep the number of\n\
1946 elements as similar as possible while applying maximum and minimum\n\
1949 The default implementation uses @code{mode_for_vector} to find the\n\
1950 requested mode, returning a mode with the same size as @var{vector_mode}\n\
1951 when @var{nunits} is zero. This is the correct behavior for most targets.",
1953 (machine_mode vector_mode, scalar_mode element_mode, poly_uint64 nunits),
1954 default_vectorize_related_mode)
1956 /* Function to get a target mode for a vector mask. */
1959 "Return the mode to use for a vector mask that holds one boolean\n\
1960 result for each element of vector mode @var{mode}. The returned mask mode\n\
1961 can be a vector of integers (class @code{MODE_VECTOR_INT}), a vector of\n\
1962 booleans (class @code{MODE_VECTOR_BOOL}) or a scalar integer (class\n\
1963 @code{MODE_INT}). Return an empty @code{opt_machine_mode} if no such\n\
1964 mask mode exists.\n\
1966 The default implementation returns a @code{MODE_VECTOR_INT} with the\n\
1967 same size and number of elements as @var{mode}, if such a mode exists.",
1969 (machine_mode mode),
1970 default_get_mask_mode)
1972 /* Function to say whether a masked operation is expensive when the
1973 mask is all zeros. */
1975 (empty_mask_is_expensive,
1976 "This hook returns true if masked internal function @var{ifn} (really of\n\
1977 type @code{internal_fn}) should be considered expensive when the mask is\n\
1978 all zeros. GCC can then try to branch around the instruction instead.",
1981 default_empty_mask_is_expensive)
1983 /* Target builtin that implements vector gather operation. */
1986 "Target builtin that implements vector gather operation. @var{mem_vectype}\n\
1987 is the vector type of the load and @var{index_type} is scalar type of\n\
1988 the index, scaled by @var{scale}.\n\
1989 The default is @code{NULL_TREE} which means to not vectorize gather\n\
1992 (const_tree mem_vectype, const_tree index_type, int scale),
1995 /* Target builtin that implements vector scatter operation. */
1998 "Target builtin that implements vector scatter operation. @var{vectype}\n\
1999 is the vector type of the store and @var{index_type} is scalar type of\n\
2000 the index, scaled by @var{scale}.\n\
2001 The default is @code{NULL_TREE} which means to not vectorize scatter\n\
2004 (const_tree vectype, const_tree index_type, int scale),
2007 /* Target function to initialize the cost model for a loop or block. */
2010 "This hook should initialize target-specific data structures in preparation "
2011 "for modeling the costs of vectorizing a loop or basic block. The default "
2012 "allocates three unsigned integers for accumulating costs for the prologue, "
2013 "body, and epilogue of the loop or basic block. If @var{loop_info} is "
2014 "non-NULL, it identifies the loop being vectorized; otherwise a single block "
2015 "is being vectorized.",
2017 (class loop *loop_info),
2020 /* Target function to record N statements of the given kind using the
2021 given vector type within the cost model data for the current loop or
2025 "This hook should update the target-specific @var{data} in response to "
2026 "adding @var{count} copies of the given @var{kind} of statement to a "
2027 "loop or basic block. The default adds the builtin vectorizer cost for "
2028 "the copies of the statement to the accumulator specified by @var{where}, "
2029 "(the prologue, body, or epilogue) and returns the amount added. The "
2030 "return value should be viewed as a tentative cost that may later be "
2033 (void *data, int count, enum vect_cost_for_stmt kind,
2034 class _stmt_vec_info *stmt_info, int misalign,
2035 enum vect_cost_model_location where),
2036 default_add_stmt_cost)
2038 /* Target function to calculate the total cost of the current vectorized
2042 "This hook should complete calculations of the cost of vectorizing a loop "
2043 "or basic block based on @var{data}, and return the prologue, body, and "
2044 "epilogue costs as unsigned integers. The default returns the value of "
2045 "the three accumulators.",
2047 (void *data, unsigned *prologue_cost, unsigned *body_cost,
2048 unsigned *epilogue_cost),
2049 default_finish_cost)
2051 /* Function to delete target-specific cost modeling data. */
2054 "This hook should release @var{data} and any related data structures "
2055 "allocated by TARGET_VECTORIZE_INIT_COST. The default releases the "
2059 default_destroy_cost_data)
2061 HOOK_VECTOR_END (vectorize)
2064 #define HOOK_PREFIX "TARGET_"
2067 (preferred_else_value,
2068 "This hook returns the target's preferred final argument for a call\n\
2069 to conditional internal function @var{ifn} (really of type\n\
2070 @code{internal_fn}). @var{type} specifies the return type of the\n\
2071 function and @var{ops} are the operands to the conditional operation,\n\
2072 of which there are @var{nops}.\n\
2074 For example, if @var{ifn} is @code{IFN_COND_ADD}, the hook returns\n\
2075 a value of type @var{type} that should be used when @samp{@var{ops}[0]}\n\
2076 and @samp{@var{ops}[1]} are conditionally added together.\n\
2078 This hook is only relevant if the target supports conditional patterns\n\
2079 like @code{cond_add@var{m}}. The default implementation returns a zero\n\
2080 constant of type @var{type}.",
2082 (unsigned ifn, tree type, unsigned nops, tree *ops),
2083 default_preferred_else_value)
2086 (record_offload_symbol,
2087 "Used when offloaded functions are seen in the compilation unit and no named\n\
2088 sections are available. It is called once for each symbol that must be\n\
2089 recorded in the offload function and variable table.",
2094 (absolute_biggest_alignment,
2095 "If defined, this target hook specifies the absolute biggest alignment\n\
2096 that a type or variable can have on this machine, otherwise,\n\
2097 @code{BIGGEST_ALIGNMENT} is used.",
2098 HOST_WIDE_INT, BIGGEST_ALIGNMENT)
2100 /* Allow target specific overriding of option settings after options have
2101 been changed by an attribute or pragma or when it is reset at the
2102 end of the code affected by an attribute or pragma. */
2104 (override_options_after_change,
2105 "This target function is similar to the hook @code{TARGET_OPTION_OVERRIDE}\n\
2106 but is called when the optimize level is changed via an attribute or\n\
2107 pragma or when it is reset at the end of the code affected by the\n\
2108 attribute or pragma. It is not called at the beginning of compilation\n\
2109 when @code{TARGET_OPTION_OVERRIDE} is called so if you want to perform these\n\
2110 actions then, you should have @code{TARGET_OPTION_OVERRIDE} call\n\
2111 @code{TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE}.",
2117 "Used when writing out the list of options into an LTO file. It should\n\
2118 translate any relevant target-specific options (such as the ABI in use)\n\
2119 into one of the @option{-foffload} options that exist as a common interface\n\
2120 to express such options. It should return a string containing these options,\n\
2121 separated by spaces, which the caller will free.\n",
2122 char *, (void), hook_charptr_void_null)
2125 (eh_return_filter_mode,
2126 "Return machine mode for filter value.",
2127 scalar_int_mode, (void),
2128 default_eh_return_filter_mode)
2130 /* Return machine mode for libgcc expanded cmp instructions. */
2132 (libgcc_cmp_return_mode,
2133 "This target hook should return the mode to be used for the return value\n\
2134 of compare instructions expanded to libgcc calls. If not defined\n\
2135 @code{word_mode} is returned which is the right choice for a majority of\n\
2137 scalar_int_mode, (void),
2138 default_libgcc_cmp_return_mode)
2140 /* Return machine mode for libgcc expanded shift instructions. */
2142 (libgcc_shift_count_mode,
2143 "This target hook should return the mode to be used for the shift count operand\n\
2144 of shift instructions expanded to libgcc calls. If not defined\n\
2145 @code{word_mode} is returned which is the right choice for a majority of\n\
2147 scalar_int_mode, (void),
2148 default_libgcc_shift_count_mode)
2150 /* Return machine mode to be used for _Unwind_Word type. */
2153 "Return machine mode to be used for @code{_Unwind_Word} type.\n\
2154 The default is to use @code{word_mode}.",
2155 scalar_int_mode, (void),
2156 default_unwind_word_mode)
2158 /* Given two decls, merge their attributes and return the result. */
2160 (merge_decl_attributes,
2161 "Define this target hook if the merging of decl attributes needs special\n\
2162 handling. If defined, the result is a list of the combined\n\
2163 @code{DECL_ATTRIBUTES} of @var{olddecl} and @var{newdecl}.\n\
2164 @var{newdecl} is a duplicate declaration of @var{olddecl}. Examples of\n\
2165 when this is needed are when one attribute overrides another, or when an\n\
2166 attribute is nullified by a subsequent definition. This function may\n\
2167 call @code{merge_attributes} to handle machine-independent merging.\n\
2169 @findex TARGET_DLLIMPORT_DECL_ATTRIBUTES\n\
2170 If the only target-specific handling you require is @samp{dllimport}\n\
2171 for Microsoft Windows targets, you should define the macro\n\
2172 @code{TARGET_DLLIMPORT_DECL_ATTRIBUTES} to @code{1}. The compiler\n\
2173 will then define a function called\n\
2174 @code{merge_dllimport_decl_attributes} which can then be defined as\n\
2175 the expansion of @code{TARGET_MERGE_DECL_ATTRIBUTES}. You can also\n\
2176 add @code{handle_dll_attribute} in the attribute table for your port\n\
2177 to perform initial processing of the @samp{dllimport} and\n\
2178 @samp{dllexport} attributes. This is done in @file{i386/cygwin.h} and\n\
2179 @file{i386/i386.c}, for example.",
2180 tree, (tree olddecl, tree newdecl),
2181 merge_decl_attributes)
2183 /* Given two types, merge their attributes and return the result. */
2185 (merge_type_attributes,
2186 "Define this target hook if the merging of type attributes needs special\n\
2187 handling. If defined, the result is a list of the combined\n\
2188 @code{TYPE_ATTRIBUTES} of @var{type1} and @var{type2}. It is assumed\n\
2189 that @code{comptypes} has already been called and returned 1. This\n\
2190 function may call @code{merge_attributes} to handle machine-independent\n\
2192 tree, (tree type1, tree type2),
2193 merge_type_attributes)
2195 /* Table of machine attributes and functions to handle them.
2199 "If defined, this target hook points to an array of @samp{struct\n\
2200 attribute_spec} (defined in @file{tree-core.h}) specifying the machine\n\
2201 specific attributes for this target and some of the restrictions on the\n\
2202 entities to which these attributes are applied and the arguments they\n\
2204 const struct attribute_spec *, NULL)
2206 /* Return true iff attribute NAME expects a plain identifier as its first
2209 (attribute_takes_identifier_p,
2210 "If defined, this target hook is a function which returns true if the\n\
2211 machine-specific attribute named @var{name} expects an identifier\n\
2212 given as its first argument to be passed on as a plain identifier, not\n\
2213 subjected to name lookup. If this is not defined, the default is\n\
2214 false for all machine-specific attributes.",
2215 bool, (const_tree name),
2216 hook_bool_const_tree_false)
2218 /* Return zero if the attributes on TYPE1 and TYPE2 are incompatible,
2219 one if they are compatible and two if they are nearly compatible
2220 (which causes a warning to be generated). */
2222 (comp_type_attributes,
2223 "If defined, this target hook is a function which returns zero if the attributes on\n\
2224 @var{type1} and @var{type2} are incompatible, one if they are compatible,\n\
2225 and two if they are nearly compatible (which causes a warning to be\n\
2226 generated). If this is not defined, machine-specific attributes are\n\
2227 supposed always to be compatible.",
2228 int, (const_tree type1, const_tree type2),
2229 hook_int_const_tree_const_tree_1)
2231 /* Assign default attributes to the newly defined TYPE. */
2233 (set_default_type_attributes,
2234 "If defined, this target hook is a function which assigns default attributes to\n\
2235 the newly defined @var{type}.",
2239 /* Insert attributes on the newly created DECL. */
2242 "Define this target hook if you want to be able to add attributes to a decl\n\
2243 when it is being created. This is normally useful for back ends which\n\
2244 wish to implement a pragma by using the attributes which correspond to\n\
2245 the pragma's effect. The @var{node} argument is the decl which is being\n\
2246 created. The @var{attr_ptr} argument is a pointer to the attribute list\n\
2247 for this decl. The list itself should not be modified, since it may be\n\
2248 shared with other decls, but attributes may be chained on the head of\n\
2249 the list and @code{*@var{attr_ptr}} modified to point to the new\n\
2250 attributes, or a copy of the list may be made if further changes are\n\
2252 void, (tree node, tree *attr_ptr),
2253 hook_void_tree_treeptr)
2255 /* Perform additional target-specific processing of generic attributes. */
2257 (handle_generic_attribute,
2258 "Define this target hook if you want to be able to perform additional\n\
2259 target-specific processing of an attribute which is handled generically\n\
2260 by a front end. The arguments are the same as those which are passed to\n\
2261 attribute handlers. So far this only affects the @var{noinit} and\n\
2262 @var{section} attribute.",
2263 tree, (tree *node, tree name, tree args, int flags, bool *no_add_attrs),
2264 hook_tree_treeptr_tree_tree_int_boolptr_null)
2266 /* Return true if FNDECL (which has at least one machine attribute)
2267 can be inlined despite its machine attributes, false otherwise. */
2269 (function_attribute_inlinable_p,
2270 "@cindex inlining\n\
2271 This target hook returns @code{true} if it is OK to inline @var{fndecl}\n\
2272 into the current function, despite its having target-specific\n\
2273 attributes, @code{false} otherwise. By default, if a function has a\n\
2274 target specific attribute attached to it, it will not be inlined.",
2275 bool, (const_tree fndecl),
2276 hook_bool_const_tree_false)
2278 /* Return true if bitfields in RECORD_TYPE should follow the
2279 Microsoft Visual C++ bitfield layout rules. */
2281 (ms_bitfield_layout_p,
2282 "This target hook returns @code{true} if bit-fields in the given\n\
2283 @var{record_type} are to be laid out following the rules of Microsoft\n\
2284 Visual C/C++, namely: (i) a bit-field won't share the same storage\n\
2285 unit with the previous bit-field if their underlying types have\n\
2286 different sizes, and the bit-field will be aligned to the highest\n\
2287 alignment of the underlying types of itself and of the previous\n\
2288 bit-field; (ii) a zero-sized bit-field will affect the alignment of\n\
2289 the whole enclosing structure, even if it is unnamed; except that\n\
2290 (iii) a zero-sized bit-field will be disregarded unless it follows\n\
2291 another bit-field of nonzero size. If this hook returns @code{true},\n\
2292 other macros that control bit-field layout are ignored.\n\
2294 When a bit-field is inserted into a packed record, the whole size\n\
2295 of the underlying type is used by one or more same-size adjacent\n\
2296 bit-fields (that is, if its long:3, 32 bits is used in the record,\n\
2297 and any additional adjacent long bit-fields are packed into the same\n\
2298 chunk of 32 bits. However, if the size changes, a new field of that\n\
2299 size is allocated). In an unpacked record, this is the same as using\n\
2300 alignment, but not equivalent when packing.\n\
2302 If both MS bit-fields and @samp{__attribute__((packed))} are used,\n\
2303 the latter will take precedence. If @samp{__attribute__((packed))} is\n\
2304 used on a single field when MS bit-fields are in use, it will take\n\
2305 precedence for that field, but the alignment of the rest of the structure\n\
2306 may affect its placement.",
2307 bool, (const_tree record_type),
2308 hook_bool_const_tree_false)
2310 /* For now this is only an interface to WORDS_BIG_ENDIAN for
2311 target-independent code like the front ends, need performance testing
2312 before switching completely to the target hook. */
2317 targhook_words_big_endian)
2319 /* Likewise for FLOAT_WORDS_BIG_ENDIAN. */
2321 (float_words_big_endian,
2324 targhook_float_words_big_endian)
2327 (float_exceptions_rounding_supported_p,
2328 "Returns true if the target supports IEEE 754 floating-point exceptions\
2329 and rounding modes, false otherwise. This is intended to relate to the\
2330 @code{float} and @code{double} types, but not necessarily @code{long double}.\
2331 By default, returns true if the @code{adddf3} instruction pattern is\
2332 available and false otherwise, on the assumption that hardware floating\
2333 point supports exceptions and rounding modes but software floating point\
2336 default_float_exceptions_rounding_supported_p)
2338 /* True if the target supports decimal floating point. */
2340 (decimal_float_supported_p,
2341 "Returns true if the target supports decimal floating point.",
2343 default_decimal_float_supported_p)
2345 /* True if the target supports fixed-point. */
2347 (fixed_point_supported_p,
2348 "Returns true if the target supports fixed-point arithmetic.",
2350 default_fixed_point_supported_p)
2352 /* Return true if anonymous bitfields affect structure alignment. */
2354 (align_anon_bitfield,
2355 "When @code{PCC_BITFIELD_TYPE_MATTERS} is true this hook will determine\n\
2356 whether unnamed bitfields affect the alignment of the containing\n\
2357 structure. The hook should return true if the structure should inherit\n\
2358 the alignment requirements of an unnamed bitfield's type.",
2360 hook_bool_void_false)
2362 /* Return true if volatile bitfields should use the narrowest type possible.
2363 Return false if they should use the container type. */
2365 (narrow_volatile_bitfield,
2366 "This target hook should return @code{true} if accesses to volatile bitfields\n\
2367 should use the narrowest mode possible. It should return @code{false} if\n\
2368 these accesses should use the bitfield container type.\n\
2370 The default is @code{false}.",
2372 hook_bool_void_false)
2374 /* Set up target-specific built-in functions. */
2377 "Define this hook if you have any machine-specific built-in functions\n\
2378 that need to be defined. It should be a function that performs the\n\
2381 Machine specific built-in functions can be useful to expand special machine\n\
2382 instructions that would otherwise not normally be generated because\n\
2383 they have no equivalent in the source language (for example, SIMD vector\n\
2384 instructions or prefetch instructions).\n\
2386 To create a built-in function, call the function\n\
2387 @code{lang_hooks.builtin_function}\n\
2388 which is defined by the language front end. You can use any type nodes set\n\
2389 up by @code{build_common_tree_nodes};\n\
2390 only language front ends that use those two functions will call\n\
2391 @samp{TARGET_INIT_BUILTINS}.",
2395 /* Initialize (if INITIALIZE_P is true) and return the target-specific
2396 built-in function decl for CODE.
2397 Return NULL if that is not possible. Return error_mark_node if CODE
2398 is outside of the range of valid target builtin function codes. */
2401 "Define this hook if you have any machine-specific built-in functions\n\
2402 that need to be defined. It should be a function that returns the\n\
2403 builtin function declaration for the builtin function code @var{code}.\n\
2404 If there is no such builtin and it cannot be initialized at this time\n\
2405 if @var{initialize_p} is true the function should return @code{NULL_TREE}.\n\
2406 If @var{code} is out of range the function should return\n\
2407 @code{error_mark_node}.",
2408 tree, (unsigned code, bool initialize_p), NULL)
2410 /* Expand a target-specific builtin. */
2414 Expand a call to a machine specific built-in function that was set up by\n\
2415 @samp{TARGET_INIT_BUILTINS}. @var{exp} is the expression for the\n\
2416 function call; the result should go to @var{target} if that is\n\
2417 convenient, and have mode @var{mode} if that is convenient.\n\
2418 @var{subtarget} may be used as the target for computing one of\n\
2419 @var{exp}'s operands. @var{ignore} is nonzero if the value is to be\n\
2420 ignored. This function should return the result of the call to the\n\
2421 built-in function.",
2423 (tree exp, rtx target, rtx subtarget, machine_mode mode, int ignore),
2424 default_expand_builtin)
2426 /* Select a replacement for a target-specific builtin. This is done
2427 *before* regular type checking, and so allows the target to
2428 implement a crude form of function overloading. The result is a
2429 complete expression that implements the operation. PARAMS really
2430 has type VEC(tree,gc)*, but we don't want to include tree.h here. */
2432 (resolve_overloaded_builtin,
2433 "Select a replacement for a machine specific built-in function that\n\
2434 was set up by @samp{TARGET_INIT_BUILTINS}. This is done\n\
2435 @emph{before} regular type checking, and so allows the target to\n\
2436 implement a crude form of function overloading. @var{fndecl} is the\n\
2437 declaration of the built-in function. @var{arglist} is the list of\n\
2438 arguments passed to the built-in function. The result is a\n\
2439 complete expression that implements the operation, usually\n\
2440 another @code{CALL_EXPR}.\n\
2441 @var{arglist} really has type @samp{VEC(tree,gc)*}",
2442 tree, (unsigned int /*location_t*/ loc, tree fndecl, void *arglist), NULL)
2445 (check_builtin_call,
2446 "Perform semantic checking on a call to a machine-specific built-in\n\
2447 function after its arguments have been constrained to the function\n\
2448 signature. Return true if the call is valid, otherwise report an error\n\
2449 and return false.\n\
2451 This hook is called after @code{TARGET_RESOLVE_OVERLOADED_BUILTIN}.\n\
2452 The call was originally to built-in function @var{orig_fndecl},\n\
2453 but after the optional @code{TARGET_RESOLVE_OVERLOADED_BUILTIN}\n\
2454 step is now to built-in function @var{fndecl}. @var{loc} is the\n\
2455 location of the call and @var{args} is an array of function arguments,\n\
2456 of which there are @var{nargs}. @var{arg_loc} specifies the location\n\
2458 bool, (location_t loc, vec<location_t> arg_loc, tree fndecl,
2459 tree orig_fndecl, unsigned int nargs, tree *args),
2462 /* Fold a target-specific builtin to a tree valid for both GIMPLE
2466 "Fold a call to a machine specific built-in function that was set up by\n\
2467 @samp{TARGET_INIT_BUILTINS}. @var{fndecl} is the declaration of the\n\
2468 built-in function. @var{n_args} is the number of arguments passed to\n\
2469 the function; the arguments themselves are pointed to by @var{argp}.\n\
2470 The result is another tree, valid for both GIMPLE and GENERIC,\n\
2471 containing a simplified expression for the call's result. If\n\
2472 @var{ignore} is true the value will be ignored.",
2473 tree, (tree fndecl, int n_args, tree *argp, bool ignore),
2474 hook_tree_tree_int_treep_bool_null)
2476 /* Fold a target-specific builtin to a valid GIMPLE tree. */
2478 (gimple_fold_builtin,
2479 "Fold a call to a machine specific built-in function that was set up\n\
2480 by @samp{TARGET_INIT_BUILTINS}. @var{gsi} points to the gimple\n\
2481 statement holding the function call. Returns true if any change\n\
2482 was made to the GIMPLE stream.",
2483 bool, (gimple_stmt_iterator *gsi),
2484 hook_bool_gsiptr_false)
2486 /* Target hook is used to compare the target attributes in two functions to
2487 determine which function's features get higher priority. This is used
2488 during function multi-versioning to figure out the order in which two
2489 versions must be dispatched. A function version with a higher priority
2490 is checked for dispatching earlier. DECL1 and DECL2 are
2491 the two function decls that will be compared. It returns positive value
2492 if DECL1 is higher priority, negative value if DECL2 is higher priority
2493 and 0 if they are the same. */
2495 (compare_version_priority,
2496 "This hook is used to compare the target attributes in two functions to\n\
2497 determine which function's features get higher priority. This is used\n\
2498 during function multi-versioning to figure out the order in which two\n\
2499 versions must be dispatched. A function version with a higher priority\n\
2500 is checked for dispatching earlier. @var{decl1} and @var{decl2} are\n\
2501 the two function decls that will be compared.",
2502 int, (tree decl1, tree decl2), NULL)
2504 /* Target hook is used to generate the dispatcher logic to invoke the right
2505 function version at run-time for a given set of function versions.
2506 ARG points to the callgraph node of the dispatcher function whose body
2507 must be generated. */
2509 (generate_version_dispatcher_body,
2510 "This hook is used to generate the dispatcher logic to invoke the right\n\
2511 function version at run-time for a given set of function versions.\n\
2512 @var{arg} points to the callgraph node of the dispatcher function whose\n\
2513 body must be generated.",
2514 tree, (void *arg), NULL)
2516 /* Target hook is used to get the dispatcher function for a set of function
2517 versions. The dispatcher function is called to invoke the right function
2518 version at run-time. DECL is one version from a set of semantically
2519 identical versions. */
2521 (get_function_versions_dispatcher,
2522 "This hook is used to get the dispatcher function for a set of function\n\
2523 versions. The dispatcher function is called to invoke the right function\n\
2524 version at run-time. @var{decl} is one version from a set of semantically\n\
2525 identical versions.",
2526 tree, (void *decl), NULL)
2528 /* Returns a code for a target-specific builtin that implements
2529 reciprocal of a target-specific function, or NULL_TREE if not available. */
2531 (builtin_reciprocal,
2532 "This hook should return the DECL of a function that implements the\n\
2533 reciprocal of the machine-specific builtin function @var{fndecl}, or\n\
2534 @code{NULL_TREE} if such a function is not available.",
2535 tree, (tree fndecl),
2536 default_builtin_reciprocal)
2538 /* For a vendor-specific TYPE, return a pointer to a statically-allocated
2539 string containing the C++ mangling for TYPE. In all other cases, return
2543 "If your target defines any fundamental types, or any types your target\n\
2544 uses should be mangled differently from the default, define this hook\n\
2545 to return the appropriate encoding for these types as part of a C++\n\
2546 mangled name. The @var{type} argument is the tree structure representing\n\
2547 the type to be mangled. The hook may be applied to trees which are\n\
2548 not target-specific fundamental types; it should return @code{NULL}\n\
2549 for all such types, as well as arguments it does not recognize. If the\n\
2550 return value is not @code{NULL}, it must point to a statically-allocated\n\
2553 Target-specific fundamental types might be new fundamental types or\n\
2554 qualified versions of ordinary fundamental types. Encode new\n\
2555 fundamental types as @samp{@w{u @var{n} @var{name}}}, where @var{name}\n\
2556 is the name used for the type in source code, and @var{n} is the\n\
2557 length of @var{name} in decimal. Encode qualified versions of\n\
2558 ordinary types as @samp{@w{U @var{n} @var{name} @var{code}}}, where\n\
2559 @var{name} is the name used for the type qualifier in source code,\n\
2560 @var{n} is the length of @var{name} as above, and @var{code} is the\n\
2561 code used to represent the unqualified version of this type. (See\n\
2562 @code{write_builtin_type} in @file{cp/mangle.c} for the list of\n\
2563 codes.) In both cases the spaces are for clarity; do not include any\n\
2564 spaces in your string.\n\
2566 This hook is applied to types prior to typedef resolution. If the mangled\n\
2567 name for a particular type depends only on that type's main variant, you\n\
2568 can perform typedef resolution yourself using @code{TYPE_MAIN_VARIANT}\n\
2571 The default version of this hook always returns @code{NULL}, which is\n\
2572 appropriate for a target that does not define any new fundamental\n\
2574 const char *, (const_tree type),
2575 hook_constcharptr_const_tree_null)
2577 /* Make any adjustments to libfunc names needed for this target. */
2580 "This hook should declare additional library routines or rename\n\
2581 existing ones, using the functions @code{set_optab_libfunc} and\n\
2582 @code{init_one_libfunc} defined in @file{optabs.c}.\n\
2583 @code{init_optabs} calls this macro after initializing all the normal\n\
2584 library routines.\n\
2586 The default is to do nothing. Most ports don't need to define this hook.",
2590 /* Add a __gnu_ prefix to library functions rather than just __. */
2592 (libfunc_gnu_prefix,
2593 "If false (the default), internal library routines start with two\n\
2594 underscores. If set to true, these routines start with @code{__gnu_}\n\
2595 instead. E.g., @code{__muldi3} changes to @code{__gnu_muldi3}. This\n\
2596 currently only affects functions defined in @file{libgcc2.c}. If this\n\
2597 is set to true, the @file{tm.h} file must also\n\
2598 @code{#define LIBGCC2_GNU_PREFIX}.",
2601 /* Given a decl, a section name, and whether the decl initializer
2602 has relocs, choose attributes for the section. */
2603 /* ??? Should be merged with SELECT_SECTION and UNIQUE_SECTION. */
2605 (section_type_flags,
2606 "Choose a set of section attributes for use by @code{TARGET_ASM_NAMED_SECTION}\n\
2607 based on a variable or function decl, a section name, and whether or not the\n\
2608 declaration's initializer may contain runtime relocations. @var{decl} may be\n\
2609 null, in which case read-write data should be assumed.\n\
2611 The default version of this function handles choosing code vs data,\n\
2612 read-only vs read-write data, and @code{flag_pic}. You should only\n\
2613 need to override this if your target has special flags that might be\n\
2614 set via @code{__attribute__}.",
2615 unsigned int, (tree decl, const char *name, int reloc),
2616 default_section_type_flags)
2620 "This hook determines whether a function from a class of functions\n\
2621 @var{fn_class} is present in the target C library.",
2622 bool, (enum function_class fn_class),
2623 default_libc_has_function)
2626 (libc_has_fast_function,
2627 "This hook determines whether a function from a class of functions\n\
2628 @code{(enum function_class)}@var{fcode} has a fast implementation.",
2630 default_libc_has_fast_function)
2632 /* True if new jumps cannot be created, to replace existing ones or
2633 not, at the current point in the compilation. */
2635 (cannot_modify_jumps_p,
2636 "This target hook returns @code{true} past the point in which new jump\n\
2637 instructions could be created. On machines that require a register for\n\
2638 every jump such as the SHmedia ISA of SH5, this point would typically be\n\
2639 reload, so this target hook should be defined to a function such as:\n\
2643 cannot_modify_jumps_past_reload_p ()\n\
2645 return (reload_completed || reload_in_progress);\n\
2649 hook_bool_void_false)
2651 /* True if FOLLOWER may be modified to follow FOLLOWEE. */
2654 "FOLLOWER and FOLLOWEE are JUMP_INSN instructions;\
2655 return true if FOLLOWER may be modified to follow FOLLOWEE;\
2656 false, if it can't.\
2657 For example, on some targets, certain kinds of branches can't be made to\
2658 follow through a hot/cold partitioning.",
2659 bool, (const rtx_insn *follower, const rtx_insn *followee),
2660 hook_bool_const_rtx_insn_const_rtx_insn_true)
2662 /* Return true if the target supports conditional execution. */
2664 (have_conditional_execution,
2665 "This target hook returns true if the target supports conditional execution.\n\
2666 This target hook is required only when the target has several different\n\
2667 modes and they have different conditional execution capability, such as ARM.",
2669 default_have_conditional_execution)
2673 "This function prepares to emit a comparison insn for the first compare in a\n\
2674 sequence of conditional comparisions. It returns an appropriate comparison\n\
2675 with @code{CC} for passing to @code{gen_ccmp_next} or @code{cbranch_optab}.\n\
2676 The insns to prepare the compare are saved in @var{prep_seq} and the compare\n\
2677 insns are saved in @var{gen_seq}. They will be emitted when all the\n\
2678 compares in the the conditional comparision are generated without error.\n\
2679 @var{code} is the @code{rtx_code} of the compare for @var{op0} and @var{op1}.",
2680 rtx, (rtx_insn **prep_seq, rtx_insn **gen_seq, int code, tree op0, tree op1),
2685 "This function prepares to emit a conditional comparison within a sequence\n\
2686 of conditional comparisons. It returns an appropriate comparison with\n\
2687 @code{CC} for passing to @code{gen_ccmp_next} or @code{cbranch_optab}.\n\
2688 The insns to prepare the compare are saved in @var{prep_seq} and the compare\n\
2689 insns are saved in @var{gen_seq}. They will be emitted when all the\n\
2690 compares in the conditional comparision are generated without error. The\n\
2691 @var{prev} expression is the result of a prior call to @code{gen_ccmp_first}\n\
2692 or @code{gen_ccmp_next}. It may return @code{NULL} if the combination of\n\
2693 @var{prev} and this comparison is not supported, otherwise the result must\n\
2694 be appropriate for passing to @code{gen_ccmp_next} or @code{cbranch_optab}.\n\
2695 @var{code} is the @code{rtx_code} of the compare for @var{op0} and @var{op1}.\n\
2696 @var{bit_code} is @code{AND} or @code{IOR}, which is the op on the compares.",
2697 rtx, (rtx_insn **prep_seq, rtx_insn **gen_seq, rtx prev, int cmp_code, tree op0, tree op1, int bit_code),
2700 /* Return a new value for loop unroll size. */
2702 (loop_unroll_adjust,
2703 "This target hook returns a new value for the number of times @var{loop}\n\
2704 should be unrolled. The parameter @var{nunroll} is the number of times\n\
2705 the loop is to be unrolled. The parameter @var{loop} is a pointer to\n\
2706 the loop, which is going to be checked for unrolling. This target hook\n\
2707 is required only when the target has special constraints like maximum\n\
2708 number of memory accesses.",
2709 unsigned, (unsigned nunroll, class loop *loop),
2712 /* True if X is a legitimate MODE-mode immediate operand. */
2714 (legitimate_constant_p,
2715 "This hook returns true if @var{x} is a legitimate constant for a\n\
2716 @var{mode}-mode immediate operand on the target machine. You can assume that\n\
2717 @var{x} satisfies @code{CONSTANT_P}, so you need not check this.\n\
2719 The default definition returns true.",
2720 bool, (machine_mode mode, rtx x),
2721 hook_bool_mode_rtx_true)
2723 /* True if the constant X cannot be placed in the constant pool. */
2725 (cannot_force_const_mem,
2726 "This hook should return true if @var{x} is of a form that cannot (or\n\
2727 should not) be spilled to the constant pool. @var{mode} is the mode\n\
2730 The default version of this hook returns false.\n\
2732 The primary reason to define this hook is to prevent reload from\n\
2733 deciding that a non-legitimate constant would be better reloaded\n\
2734 from the constant pool instead of spilling and reloading a register\n\
2735 holding the constant. This restriction is often true of addresses\n\
2736 of TLS symbols for various targets.",
2737 bool, (machine_mode mode, rtx x),
2738 hook_bool_mode_rtx_false)
2741 (cannot_copy_insn_p,
2742 "True if the insn @var{x} cannot be duplicated.",
2743 bool, (rtx_insn *), NULL)
2745 /* True if X is considered to be commutative. */
2748 "This target hook returns @code{true} if @var{x} is considered to be commutative.\n\
2749 Usually, this is just COMMUTATIVE_P (@var{x}), but the HP PA doesn't consider\n\
2750 PLUS to be commutative inside a MEM@. @var{outer_code} is the rtx code\n\
2751 of the enclosing rtl, if known, otherwise it is UNKNOWN.",
2752 bool, (const_rtx x, int outer_code),
2753 hook_bool_const_rtx_commutative_p)
2755 /* True if ADDR is an address-expression whose effect depends
2756 on the mode of the memory reference it is used in. */
2758 (mode_dependent_address_p,
2759 "This hook returns @code{true} if memory address @var{addr} in address\n\
2760 space @var{addrspace} can have\n\
2761 different meanings depending on the machine mode of the memory\n\
2762 reference it is used for or if the address is valid for some modes\n\
2765 Autoincrement and autodecrement addresses typically have mode-dependent\n\
2766 effects because the amount of the increment or decrement is the size\n\
2767 of the operand being addressed. Some machines have other mode-dependent\n\
2768 addresses. Many RISC machines have no mode-dependent addresses.\n\
2770 You may assume that @var{addr} is a valid address for the machine.\n\
2772 The default version of this hook returns @code{false}.",
2773 bool, (const_rtx addr, addr_space_t addrspace),
2774 default_mode_dependent_address_p)
2776 /* Given an invalid address X for a given machine mode, try machine-specific
2777 ways to make it legitimate. Return X or an invalid address on failure. */
2779 (legitimize_address,
2780 "This hook is given an invalid memory address @var{x} for an\n\
2781 operand of mode @var{mode} and should try to return a valid memory\n\
2784 @findex break_out_memory_refs\n\
2785 @var{x} will always be the result of a call to @code{break_out_memory_refs},\n\
2786 and @var{oldx} will be the operand that was given to that function to produce\n\
2789 The code of the hook should not alter the substructure of\n\
2790 @var{x}. If it transforms @var{x} into a more legitimate form, it\n\
2791 should return the new @var{x}.\n\
2793 It is not necessary for this hook to come up with a legitimate address,\n\
2794 with the exception of native TLS addresses (@pxref{Emulated TLS}).\n\
2795 The compiler has standard ways of doing so in all cases. In fact, if\n\
2796 the target supports only emulated TLS, it\n\
2797 is safe to omit this hook or make it return @var{x} if it cannot find\n\
2798 a valid way to legitimize the address. But often a machine-dependent\n\
2799 strategy can generate better code.",
2800 rtx, (rtx x, rtx oldx, machine_mode mode),
2801 default_legitimize_address)
2803 /* Given an address RTX, undo the effects of LEGITIMIZE_ADDRESS. */
2805 (delegitimize_address,
2806 "This hook is used to undo the possibly obfuscating effects of the\n\
2807 @code{LEGITIMIZE_ADDRESS} and @code{LEGITIMIZE_RELOAD_ADDRESS} target\n\
2808 macros. Some backend implementations of these macros wrap symbol\n\
2809 references inside an @code{UNSPEC} rtx to represent PIC or similar\n\
2810 addressing modes. This target hook allows GCC's optimizers to understand\n\
2811 the semantics of these opaque @code{UNSPEC}s by converting them back\n\
2812 into their original form.",
2814 delegitimize_mem_from_attrs)
2816 /* Given an RTX, return true if it is not ok to emit it into debug info
2819 (const_not_ok_for_debug_p,
2820 "This hook should return true if @var{x} should not be emitted into\n\
2823 default_const_not_ok_for_debug_p)
2825 /* Given an address RTX, say whether it is valid. */
2827 (legitimate_address_p,
2828 "A function that returns whether @var{x} (an RTX) is a legitimate memory\n\
2829 address on the target machine for a memory operand of mode @var{mode}.\n\
2831 Legitimate addresses are defined in two variants: a strict variant and a\n\
2832 non-strict one. The @var{strict} parameter chooses which variant is\n\
2833 desired by the caller.\n\
2835 The strict variant is used in the reload pass. It must be defined so\n\
2836 that any pseudo-register that has not been allocated a hard register is\n\
2837 considered a memory reference. This is because in contexts where some\n\
2838 kind of register is required, a pseudo-register with no hard register\n\
2839 must be rejected. For non-hard registers, the strict variant should look\n\
2840 up the @code{reg_renumber} array; it should then proceed using the hard\n\
2841 register number in the array, or treat the pseudo as a memory reference\n\
2842 if the array holds @code{-1}.\n\
2844 The non-strict variant is used in other passes. It must be defined to\n\
2845 accept all pseudo-registers in every context where some kind of\n\
2846 register is required.\n\
2848 Normally, constant addresses which are the sum of a @code{symbol_ref}\n\
2849 and an integer are stored inside a @code{const} RTX to mark them as\n\
2850 constant. Therefore, there is no need to recognize such sums\n\
2851 specifically as legitimate addresses. Normally you would simply\n\
2852 recognize any @code{const} as legitimate.\n\
2854 Usually @code{PRINT_OPERAND_ADDRESS} is not prepared to handle constant\n\
2855 sums that are not marked with @code{const}. It assumes that a naked\n\
2856 @code{plus} indicates indexing. If so, then you @emph{must} reject such\n\
2857 naked constant sums as illegitimate addresses, so that none of them will\n\
2858 be given to @code{PRINT_OPERAND_ADDRESS}.\n\
2860 @cindex @code{TARGET_ENCODE_SECTION_INFO} and address validation\n\
2861 On some machines, whether a symbolic address is legitimate depends on\n\
2862 the section that the address refers to. On these machines, define the\n\
2863 target hook @code{TARGET_ENCODE_SECTION_INFO} to store the information\n\
2864 into the @code{symbol_ref}, and then check for it here. When you see a\n\
2865 @code{const}, you will have to look inside it to find the\n\
2866 @code{symbol_ref} in order to determine the section. @xref{Assembler\n\
2869 @cindex @code{GO_IF_LEGITIMATE_ADDRESS}\n\
2870 Some ports are still using a deprecated legacy substitute for\n\
2871 this hook, the @code{GO_IF_LEGITIMATE_ADDRESS} macro. This macro\n\
2875 #define GO_IF_LEGITIMATE_ADDRESS (@var{mode}, @var{x}, @var{label})\n\
2879 and should @code{goto @var{label}} if the address @var{x} is a valid\n\
2880 address on the target machine for a memory operand of mode @var{mode}.\n\
2882 @findex REG_OK_STRICT\n\
2883 Compiler source files that want to use the strict variant of this\n\
2884 macro define the macro @code{REG_OK_STRICT}. You should use an\n\
2885 @code{#ifdef REG_OK_STRICT} conditional to define the strict variant in\n\
2886 that case and the non-strict variant otherwise.\n\
2888 Using the hook is usually simpler because it limits the number of\n\
2889 files that are recompiled when changes are made.",
2890 bool, (machine_mode mode, rtx x, bool strict),
2891 default_legitimate_address_p)
2893 /* True if the given constant can be put into an object_block. */
2895 (use_blocks_for_constant_p,
2896 "This hook should return true if pool entries for constant @var{x} can\n\
2897 be placed in an @code{object_block} structure. @var{mode} is the mode\n\
2900 The default version returns false for all constants.",
2901 bool, (machine_mode mode, const_rtx x),
2902 hook_bool_mode_const_rtx_false)
2904 /* True if the given decl can be put into an object_block. */
2906 (use_blocks_for_decl_p,
2907 "This hook should return true if pool entries for @var{decl} should\n\
2908 be placed in an @code{object_block} structure.\n\
2910 The default version returns true for all decls.",
2911 bool, (const_tree decl),
2912 hook_bool_const_tree_true)
2914 /* The minimum and maximum byte offsets for anchored addresses. */
2917 "The minimum offset that should be applied to a section anchor.\n\
2918 On most targets, it should be the smallest offset that can be\n\
2919 applied to a base register while still giving a legitimate address\n\
2920 for every mode. The default value is 0.",
2925 "Like @code{TARGET_MIN_ANCHOR_OFFSET}, but the maximum (inclusive)\n\
2926 offset that should be applied to section anchors. The default\n\
2930 /* True if section anchors can be used to access the given symbol. */
2932 (use_anchors_for_symbol_p,
2933 "Return true if GCC should attempt to use anchors to access @code{SYMBOL_REF}\n\
2934 @var{x}. You can assume @samp{SYMBOL_REF_HAS_BLOCK_INFO_P (@var{x})} and\n\
2935 @samp{!SYMBOL_REF_ANCHOR_P (@var{x})}.\n\
2937 The default version is correct for most targets, but you might need to\n\
2938 intercept this hook to handle things like target-specific attributes\n\
2939 or target-specific sections.",
2940 bool, (const_rtx x),
2941 default_use_anchors_for_symbol_p)
2943 /* True if target supports indirect functions. */
2946 "It returns true if the target supports GNU indirect functions.\n\
2947 The support includes the assembler, linker and dynamic linker.\n\
2948 The default value of this hook is based on target's libc.",
2950 default_has_ifunc_p)
2952 /* True if it is OK to do sibling call optimization for the specified
2953 call expression EXP. DECL will be the called function, or NULL if
2954 this is an indirect call. */
2956 (function_ok_for_sibcall,
2957 "True if it is OK to do sibling call optimization for the specified\n\
2958 call expression @var{exp}. @var{decl} will be the called function,\n\
2959 or @code{NULL} if this is an indirect call.\n\
2961 It is not uncommon for limitations of calling conventions to prevent\n\
2962 tail calls to functions outside the current unit of translation, or\n\
2963 during PIC compilation. The hook is used to enforce these restrictions,\n\
2964 as the @code{sibcall} md pattern cannot fail, or fall over to a\n\
2965 ``normal'' call. The criteria for successful sibling call optimization\n\
2966 may vary greatly between different architectures.",
2967 bool, (tree decl, tree exp),
2968 hook_bool_tree_tree_false)
2970 /* Establish appropriate back-end context for processing the function
2971 FNDECL. The argument might be NULL to indicate processing at top
2972 level, outside of any function scope. */
2974 (set_current_function,
2975 "The compiler invokes this hook whenever it changes its current function\n\
2976 context (@code{cfun}). You can define this function if\n\
2977 the back end needs to perform any initialization or reset actions on a\n\
2978 per-function basis. For example, it may be used to implement function\n\
2979 attributes that affect register usage or code generation patterns.\n\
2980 The argument @var{decl} is the declaration for the new function context,\n\
2981 and may be null to indicate that the compiler has left a function context\n\
2982 and is returning to processing at the top level.\n\
2983 The default hook function does nothing.\n\
2985 GCC sets @code{cfun} to a dummy function context during initialization of\n\
2986 some parts of the back end. The hook function is not invoked in this\n\
2987 situation; you need not worry about the hook being invoked recursively,\n\
2988 or when the back end is in a partially-initialized state.\n\
2989 @code{cfun} might be @code{NULL} to indicate processing at top level,\n\
2990 outside of any function scope.",
2991 void, (tree decl), hook_void_tree)
2993 /* True if EXP should be placed in a "small data" section. */
2996 "Returns true if @var{exp} should be placed into a ``small data'' section.\n\
2997 The default version of this hook always returns false.",
2998 bool, (const_tree exp),
2999 hook_bool_const_tree_false)
3001 /* True if EXP names an object for which name resolution must resolve
3002 to the current executable or shared library. */
3005 "Returns true if @var{exp} names an object for which name resolution\n\
3006 rules must resolve to the current ``module'' (dynamic shared library\n\
3007 or executable image).\n\
3009 The default version of this hook implements the name resolution rules\n\
3010 for ELF, which has a looser model of global name binding than other\n\
3011 currently supported object file formats.",
3012 bool, (const_tree exp),
3013 default_binds_local_p)
3015 /* Check if profiling code is before or after prologue. */
3017 (profile_before_prologue,
3018 "It returns true if target wants profile code emitted before prologue.\n\n\
3019 The default version of this hook use the target macro\n\
3020 @code{PROFILE_BEFORE_PROLOGUE}.",
3022 default_profile_before_prologue)
3024 /* Return true if a leaf function should stay leaf even with profiling
3027 (keep_leaf_when_profiled,
3028 "This target hook returns true if the target wants the leaf flag for\
3029 the current function to stay true even if it calls mcount. This might\
3030 make sense for targets using the leaf flag only to determine whether a\
3031 stack frame needs to be generated or not and for which the call to\
3032 mcount is generated before the function prologue.",
3034 default_keep_leaf_when_profiled)
3036 /* Modify and return the identifier of a DECL's external name,
3037 originally identified by ID, as required by the target,
3038 (eg, append @nn to windows32 stdcall function names).
3039 The default is to return ID without modification. */
3041 (mangle_decl_assembler_name,
3042 "Define this hook if you need to postprocess the assembler name generated\n\
3043 by target-independent code. The @var{id} provided to this hook will be\n\
3044 the computed name (e.g., the macro @code{DECL_NAME} of the @var{decl} in C,\n\
3045 or the mangled name of the @var{decl} in C++). The return value of the\n\
3046 hook is an @code{IDENTIFIER_NODE} for the appropriate mangled name on\n\
3047 your target system. The default implementation of this hook just\n\
3048 returns the @var{id} provided.",
3049 tree, (tree decl, tree id),
3050 default_mangle_decl_assembler_name)
3052 /* Do something target-specific to record properties of the DECL into
3053 the associated SYMBOL_REF. */
3055 (encode_section_info,
3056 "Define this hook if references to a symbol or a constant must be\n\
3057 treated differently depending on something about the variable or\n\
3058 function named by the symbol (such as what section it is in).\n\
3060 The hook is executed immediately after rtl has been created for\n\
3061 @var{decl}, which may be a variable or function declaration or\n\
3062 an entry in the constant pool. In either case, @var{rtl} is the\n\
3063 rtl in question. Do @emph{not} use @code{DECL_RTL (@var{decl})}\n\
3064 in this hook; that field may not have been initialized yet.\n\
3066 In the case of a constant, it is safe to assume that the rtl is\n\
3067 a @code{mem} whose address is a @code{symbol_ref}. Most decls\n\
3068 will also have this form, but that is not guaranteed. Global\n\
3069 register variables, for instance, will have a @code{reg} for their\n\
3070 rtl. (Normally the right thing to do with such unusual rtl is\n\
3073 The @var{new_decl_p} argument will be true if this is the first time\n\
3074 that @code{TARGET_ENCODE_SECTION_INFO} has been invoked on this decl. It will\n\
3075 be false for subsequent invocations, which will happen for duplicate\n\
3076 declarations. Whether or not anything must be done for the duplicate\n\
3077 declaration depends on whether the hook examines @code{DECL_ATTRIBUTES}.\n\
3078 @var{new_decl_p} is always true when the hook is called for a constant.\n\
3080 @cindex @code{SYMBOL_REF_FLAG}, in @code{TARGET_ENCODE_SECTION_INFO}\n\
3081 The usual thing for this hook to do is to record flags in the\n\
3082 @code{symbol_ref}, using @code{SYMBOL_REF_FLAG} or @code{SYMBOL_REF_FLAGS}.\n\
3083 Historically, the name string was modified if it was necessary to\n\
3084 encode more than one bit of information, but this practice is now\n\
3085 discouraged; use @code{SYMBOL_REF_FLAGS}.\n\
3087 The default definition of this hook, @code{default_encode_section_info}\n\
3088 in @file{varasm.c}, sets a number of commonly-useful bits in\n\
3089 @code{SYMBOL_REF_FLAGS}. Check whether the default does what you need\n\
3090 before overriding it.",
3091 void, (tree decl, rtx rtl, int new_decl_p),
3092 default_encode_section_info)
3094 /* Undo the effects of encode_section_info on the symbol string. */
3096 (strip_name_encoding,
3097 "Decode @var{name} and return the real name part, sans\n\
3098 the characters that @code{TARGET_ENCODE_SECTION_INFO}\n\
3100 const char *, (const char *name),
3101 default_strip_name_encoding)
3103 /* If shift optabs for MODE are known to always truncate the shift count,
3104 return the mask that they apply. Return 0 otherwise. */
3106 (shift_truncation_mask,
3107 "This function describes how the standard shift patterns for @var{mode}\n\
3108 deal with shifts by negative amounts or by more than the width of the mode.\n\
3109 @xref{shift patterns}.\n\
3111 On many machines, the shift patterns will apply a mask @var{m} to the\n\
3112 shift count, meaning that a fixed-width shift of @var{x} by @var{y} is\n\
3113 equivalent to an arbitrary-width shift of @var{x} by @var{y & m}. If\n\
3114 this is true for mode @var{mode}, the function should return @var{m},\n\
3115 otherwise it should return 0. A return value of 0 indicates that no\n\
3116 particular behavior is guaranteed.\n\
3118 Note that, unlike @code{SHIFT_COUNT_TRUNCATED}, this function does\n\
3119 @emph{not} apply to general shift rtxes; it applies only to instructions\n\
3120 that are generated by the named shift patterns.\n\
3122 The default implementation of this function returns\n\
3123 @code{GET_MODE_BITSIZE (@var{mode}) - 1} if @code{SHIFT_COUNT_TRUNCATED}\n\
3124 and 0 otherwise. This definition is always safe, but if\n\
3125 @code{SHIFT_COUNT_TRUNCATED} is false, and some shift patterns\n\
3126 nevertheless truncate the shift count, you may get better code\n\
3128 unsigned HOST_WIDE_INT, (machine_mode mode),
3129 default_shift_truncation_mask)
3131 /* Return the number of divisions in the given MODE that should be present,
3132 so that it is profitable to turn the division into a multiplication by
3135 (min_divisions_for_recip_mul,
3136 "When @option{-ffast-math} is in effect, GCC tries to optimize\n\
3137 divisions by the same divisor, by turning them into multiplications by\n\
3138 the reciprocal. This target hook specifies the minimum number of divisions\n\
3139 that should be there for GCC to perform the optimization for a variable\n\
3140 of mode @var{mode}. The default implementation returns 3 if the machine\n\
3141 has an instruction for the division, and 2 if it does not.",
3142 unsigned int, (machine_mode mode),
3143 default_min_divisions_for_recip_mul)
3146 (truly_noop_truncation,
3147 "This hook returns true if it is safe to ``convert'' a value of\n\
3148 @var{inprec} bits to one of @var{outprec} bits (where @var{outprec} is\n\
3149 smaller than @var{inprec}) by merely operating on it as if it had only\n\
3150 @var{outprec} bits. The default returns true unconditionally, which\n\
3151 is correct for most machines.\n\
3153 If @code{TARGET_MODES_TIEABLE_P} returns false for a pair of modes,\n\
3154 suboptimal code can result if this hook returns true for the corresponding\n\
3155 mode sizes. Making this hook return false in such cases may improve things.",
3156 bool, (poly_uint64 outprec, poly_uint64 inprec),
3157 hook_bool_puint64_puint64_true)
3159 /* If the representation of integral MODE is such that values are
3160 always sign-extended to a wider mode MODE_REP then return
3161 SIGN_EXTEND. Return UNKNOWN otherwise. */
3162 /* Note that the return type ought to be RTX_CODE, but that's not
3163 necessarily defined at this point. */
3166 "The representation of an integral mode can be such that the values\n\
3167 are always extended to a wider integral mode. Return\n\
3168 @code{SIGN_EXTEND} if values of @var{mode} are represented in\n\
3169 sign-extended form to @var{rep_mode}. Return @code{UNKNOWN}\n\
3170 otherwise. (Currently, none of the targets use zero-extended\n\
3171 representation this way so unlike @code{LOAD_EXTEND_OP},\n\
3172 @code{TARGET_MODE_REP_EXTENDED} is expected to return either\n\
3173 @code{SIGN_EXTEND} or @code{UNKNOWN}. Also no target extends\n\
3174 @var{mode} to @var{rep_mode} so that @var{rep_mode} is not the next\n\
3175 widest integral mode and currently we take advantage of this fact.)\n\
3177 Similarly to @code{LOAD_EXTEND_OP} you may return a non-@code{UNKNOWN}\n\
3178 value even if the extension is not performed on certain hard registers\n\
3179 as long as for the @code{REGNO_REG_CLASS} of these hard registers\n\
3180 @code{TARGET_CAN_CHANGE_MODE_CLASS} returns false.\n\
3182 Note that @code{TARGET_MODE_REP_EXTENDED} and @code{LOAD_EXTEND_OP}\n\
3183 describe two related properties. If you define\n\
3184 @code{TARGET_MODE_REP_EXTENDED (mode, word_mode)} you probably also want\n\
3185 to define @code{LOAD_EXTEND_OP (mode)} to return the same type of\n\
3188 In order to enforce the representation of @code{mode},\n\
3189 @code{TARGET_TRULY_NOOP_TRUNCATION} should return false when truncating to\n\
3191 int, (scalar_int_mode mode, scalar_int_mode rep_mode),
3192 default_mode_rep_extended)
3195 (setjmp_preserves_nonvolatile_regs_p,
3196 "On some targets, it is assumed that the compiler will spill all pseudos\n\
3197 that are live across a call to @code{setjmp}, while other targets treat\n\
3198 @code{setjmp} calls as normal function calls.\n\
3200 This hook returns false if @code{setjmp} calls do not preserve all\n\
3201 non-volatile registers so that gcc that must spill all pseudos that are\n\
3202 live across @code{setjmp} calls. Define this to return true if the\n\
3203 target does not need to spill all pseudos live across @code{setjmp} calls.\n\
3204 The default implementation conservatively assumes all pseudos must be\n\
3205 spilled across @code{setjmp} calls.",
3207 hook_bool_void_false)
3209 /* True if MODE is valid for a pointer in __attribute__((mode("MODE"))). */
3211 (valid_pointer_mode,
3212 "Define this to return nonzero if the port can handle pointers\n\
3213 with machine mode @var{mode}. The default version of this\n\
3214 hook returns true for both @code{ptr_mode} and @code{Pmode}.",
3215 bool, (scalar_int_mode mode),
3216 default_valid_pointer_mode)
3218 /* Disambiguate with errno. */
3220 (ref_may_alias_errno,
3221 "Define this to return nonzero if the memory reference @var{ref}\
3222 may alias with the system C library errno location. The default\
3223 version of this hook assumes the system C library errno location\
3224 is either a declaration of type int or accessed by dereferencing\
3226 bool, (ao_ref *ref),
3227 default_ref_may_alias_errno)
3229 /* Support for named address spaces. */
3231 #define HOOK_PREFIX "TARGET_ADDR_SPACE_"
3232 HOOK_VECTOR (TARGET_ADDR_SPACE_HOOKS, addr_space)
3234 /* MODE to use for a pointer into another address space. */
3237 "Define this to return the machine mode to use for pointers to\n\
3238 @var{address_space} if the target supports named address spaces.\n\
3239 The default version of this hook returns @code{ptr_mode}.",
3240 scalar_int_mode, (addr_space_t address_space),
3241 default_addr_space_pointer_mode)
3243 /* MODE to use for an address in another address space. */
3246 "Define this to return the machine mode to use for addresses in\n\
3247 @var{address_space} if the target supports named address spaces.\n\
3248 The default version of this hook returns @code{Pmode}.",
3249 scalar_int_mode, (addr_space_t address_space),
3250 default_addr_space_address_mode)
3252 /* True if MODE is valid for a pointer in __attribute__((mode("MODE")))
3253 in another address space. */
3255 (valid_pointer_mode,
3256 "Define this to return nonzero if the port can handle pointers\n\
3257 with machine mode @var{mode} to address space @var{as}. This target\n\
3258 hook is the same as the @code{TARGET_VALID_POINTER_MODE} target hook,\n\
3259 except that it includes explicit named address space support. The default\n\
3260 version of this hook returns true for the modes returned by either the\n\
3261 @code{TARGET_ADDR_SPACE_POINTER_MODE} or @code{TARGET_ADDR_SPACE_ADDRESS_MODE}\n\
3262 target hooks for the given address space.",
3263 bool, (scalar_int_mode mode, addr_space_t as),
3264 default_addr_space_valid_pointer_mode)
3266 /* True if an address is a valid memory address to a given named address
3267 space for a given mode. */
3269 (legitimate_address_p,
3270 "Define this to return true if @var{exp} is a valid address for mode\n\
3271 @var{mode} in the named address space @var{as}. The @var{strict}\n\
3272 parameter says whether strict addressing is in effect after reload has\n\
3273 finished. This target hook is the same as the\n\
3274 @code{TARGET_LEGITIMATE_ADDRESS_P} target hook, except that it includes\n\
3275 explicit named address space support.",
3276 bool, (machine_mode mode, rtx exp, bool strict, addr_space_t as),
3277 default_addr_space_legitimate_address_p)
3279 /* Return an updated address to convert an invalid pointer to a named
3280 address space to a valid one. If NULL_RTX is returned use machine
3281 independent methods to make the address valid. */
3283 (legitimize_address,
3284 "Define this to modify an invalid address @var{x} to be a valid address\n\
3285 with mode @var{mode} in the named address space @var{as}. This target\n\
3286 hook is the same as the @code{TARGET_LEGITIMIZE_ADDRESS} target hook,\n\
3287 except that it includes explicit named address space support.",
3288 rtx, (rtx x, rtx oldx, machine_mode mode, addr_space_t as),
3289 default_addr_space_legitimize_address)
3291 /* True if one named address space is a subset of another named address. */
3294 "Define this to return whether the @var{subset} named address space is\n\
3295 contained within the @var{superset} named address space. Pointers to\n\
3296 a named address space that is a subset of another named address space\n\
3297 will be converted automatically without a cast if used together in\n\
3298 arithmetic operations. Pointers to a superset address space can be\n\
3299 converted to pointers to a subset address space via explicit casts.",
3300 bool, (addr_space_t subset, addr_space_t superset),
3301 default_addr_space_subset_p)
3303 /* True if 0 is a valid address in the address space, or false if
3304 0 is a NULL in the address space. */
3306 (zero_address_valid,
3307 "Define this to modify the default handling of address 0 for the\n\
3308 address space. Return true if 0 should be considered a valid address.",
3309 bool, (addr_space_t as),
3310 default_addr_space_zero_address_valid)
3312 /* Function to convert an rtl expression from one address space to another. */
3315 "Define this to convert the pointer expression represented by the RTL\n\
3316 @var{op} with type @var{from_type} that points to a named address\n\
3317 space to a new pointer expression with type @var{to_type} that points\n\
3318 to a different named address space. When this hook it called, it is\n\
3319 guaranteed that one of the two address spaces is a subset of the other,\n\
3320 as determined by the @code{TARGET_ADDR_SPACE_SUBSET_P} target hook.",
3321 rtx, (rtx op, tree from_type, tree to_type),
3322 default_addr_space_convert)
3324 /* Function to encode an address space into dwarf. */
3327 "Define this to define how the address space is encoded in dwarf.\n\
3328 The result is the value to be used with @code{DW_AT_address_class}.",
3329 int, (addr_space_t as),
3330 default_addr_space_debug)
3332 /* Function to emit custom diagnostic if an address space is used. */
3335 "Define this hook if the availability of an address space depends on\n\
3336 command line options and some diagnostics should be printed when the\n\
3337 address space is used. This hook is called during parsing and allows\n\
3338 to emit a better diagnostic compared to the case where the address space\n\
3339 was not registered with @code{c_register_addr_space}. @var{as} is\n\
3340 the address space as registered with @code{c_register_addr_space}.\n\
3341 @var{loc} is the location of the address space qualifier token.\n\
3342 The default implementation does nothing.",
3343 void, (addr_space_t as, location_t loc),
3344 default_addr_space_diagnose_usage)
3346 HOOK_VECTOR_END (addr_space)
3349 #define HOOK_PREFIX "TARGET_"
3352 (static_rtx_alignment,
3353 "This hook returns the preferred alignment in bits for a\n\
3354 statically-allocated rtx, such as a constant pool entry. @var{mode}\n\
3355 is the mode of the rtx. The default implementation returns\n\
3356 @samp{GET_MODE_ALIGNMENT (@var{mode})}.",
3357 HOST_WIDE_INT, (machine_mode mode),
3358 default_static_rtx_alignment)
3361 (constant_alignment,
3362 "This hook returns the alignment in bits of a constant that is being\n\
3363 placed in memory. @var{constant} is the constant and @var{basic_align}\n\
3364 is the alignment that the object would ordinarily have.\n\
3366 The default definition just returns @var{basic_align}.\n\
3368 The typical use of this hook is to increase alignment for string\n\
3369 constants to be word aligned so that @code{strcpy} calls that copy\n\
3370 constants can be done inline. The function\n\
3371 @code{constant_alignment_word_strings} provides such a definition.",
3372 HOST_WIDE_INT, (const_tree constant, HOST_WIDE_INT basic_align),
3373 default_constant_alignment)
3376 (translate_mode_attribute,
3377 "Define this hook if during mode attribute processing, the port should\n\
3378 translate machine_mode @var{mode} to another mode. For example, rs6000's\n\
3379 @code{KFmode}, when it is the same as @code{TFmode}.\n\
3381 The default version of the hook returns that mode that was passed in.",
3382 machine_mode, (machine_mode mode),
3383 default_translate_mode_attribute)
3385 /* True if MODE is valid for the target. By "valid", we mean able to
3386 be manipulated in non-trivial ways. In particular, this means all
3387 the arithmetic is supported. */
3389 (scalar_mode_supported_p,
3390 "Define this to return nonzero if the port is prepared to handle\n\
3391 insns involving scalar mode @var{mode}. For a scalar mode to be\n\
3392 considered supported, all the basic arithmetic and comparisons\n\
3395 The default version of this hook returns true for any mode\n\
3396 required to handle the basic C types (as defined by the port).\n\
3397 Included here are the double-word arithmetic supported by the\n\
3398 code in @file{optabs.c}.",
3399 bool, (scalar_mode mode),
3400 default_scalar_mode_supported_p)
3402 /* Similarly for vector modes. "Supported" here is less strict. At
3403 least some operations are supported; need to check optabs or builtins
3404 for further details. */
3406 (vector_mode_supported_p,
3407 "Define this to return nonzero if the port is prepared to handle\n\
3408 insns involving vector mode @var{mode}. At the very least, it\n\
3409 must have move patterns for this mode.",
3410 bool, (machine_mode mode),
3411 hook_bool_mode_false)
3414 (compatible_vector_types_p,
3415 "Return true if there is no target-specific reason for treating\n\
3416 vector types @var{type1} and @var{type2} as distinct types. The caller\n\
3417 has already checked for target-independent reasons, meaning that the\n\
3418 types are known to have the same mode, to have the same number of elements,\n\
3419 and to have what the caller considers to be compatible element types.\n\
3421 The main reason for defining this hook is to reject pairs of types\n\
3422 that are handled differently by the target's calling convention.\n\
3423 For example, when a new @var{N}-bit vector architecture is added\n\
3424 to a target, the target may want to handle normal @var{N}-bit\n\
3425 @code{VECTOR_TYPE} arguments and return values in the same way as\n\
3426 before, to maintain backwards compatibility. However, it may also\n\
3427 provide new, architecture-specific @code{VECTOR_TYPE}s that are passed\n\
3428 and returned in a more efficient way. It is then important to maintain\n\
3429 a distinction between the ``normal'' @code{VECTOR_TYPE}s and the new\n\
3430 architecture-specific ones.\n\
3432 The default implementation returns true, which is correct for most targets.",
3433 bool, (const_tree type1, const_tree type2),
3434 hook_bool_const_tree_const_tree_true)
3438 "This hook can be used to define the alignment for a vector of type\n\
3439 @var{type}, in order to comply with a platform ABI. The default is to\n\
3440 require natural alignment for vector types. The alignment returned by\n\
3441 this hook must be a power-of-two multiple of the default alignment of\n\
3442 the vector element type.",
3443 HOST_WIDE_INT, (const_tree type),
3444 default_vector_alignment)
3448 "Return the mode that GCC should use for an array that has\n\
3449 @var{nelems} elements, with each element having mode @var{mode}.\n\
3450 Return no mode if the target has no special requirements. In the\n\
3451 latter case, GCC looks for an integer mode of the appropriate size\n\
3452 if available and uses BLKmode otherwise. Usually the search for the\n\
3453 integer mode is limited to @code{MAX_FIXED_MODE_SIZE}, but the\n\
3454 @code{TARGET_ARRAY_MODE_SUPPORTED_P} hook allows a larger mode to be\n\
3455 used in specific cases.\n\
3457 The main use of this hook is to specify that an array of vectors should\n\
3458 also have a vector mode. The default implementation returns no mode.",
3459 opt_machine_mode, (machine_mode mode, unsigned HOST_WIDE_INT nelems),
3460 hook_optmode_mode_uhwi_none)
3462 /* True if we should try to use a scalar mode to represent an array,
3463 overriding the usual MAX_FIXED_MODE limit. */
3465 (array_mode_supported_p,
3466 "Return true if GCC should try to use a scalar mode to store an array\n\
3467 of @var{nelems} elements, given that each element has mode @var{mode}.\n\
3468 Returning true here overrides the usual @code{MAX_FIXED_MODE} limit\n\
3469 and allows GCC to use any defined integer mode.\n\
3471 One use of this hook is to support vector load and store operations\n\
3472 that operate on several homogeneous vectors. For example, ARM NEON\n\
3473 has operations like:\n\
3476 int8x8x3_t vld3_s8 (const int8_t *)\n\
3477 @end smallexample\n\
3479 where the return type is defined as:\n\
3482 typedef struct int8x8x3_t\n\
3486 @end smallexample\n\
3488 If this hook allows @code{val} to have a scalar mode, then\n\
3489 @code{int8x8x3_t} can have the same mode. GCC can then store\n\
3490 @code{int8x8x3_t}s in registers rather than forcing them onto the stack.",
3491 bool, (machine_mode mode, unsigned HOST_WIDE_INT nelems),
3492 hook_bool_mode_uhwi_false)
3495 (libgcc_floating_mode_supported_p,
3496 "Define this to return nonzero if libgcc provides support for the \n\
3497 floating-point mode @var{mode}, which is known to pass \n\
3498 @code{TARGET_SCALAR_MODE_SUPPORTED_P}. The default version of this \n\
3499 hook returns true for all of @code{SFmode}, @code{DFmode}, \n\
3500 @code{XFmode} and @code{TFmode}, if such modes exist.",
3501 bool, (scalar_float_mode mode),
3502 default_libgcc_floating_mode_supported_p)
3506 "Define this to return the machine mode to use for the type \n\
3507 @code{_Float@var{n}}, if @var{extended} is false, or the type \n\
3508 @code{_Float@var{n}x}, if @var{extended} is true. If such a type is not\n\
3509 supported, return @code{opt_scalar_float_mode ()}. The default version of\n\
3510 this hook returns @code{SFmode} for @code{_Float32}, @code{DFmode} for\n\
3511 @code{_Float64} and @code{_Float32x} and @code{TFmode} for \n\
3512 @code{_Float128}, if those modes exist and satisfy the requirements for \n\
3513 those types and pass @code{TARGET_SCALAR_MODE_SUPPORTED_P} and \n\
3514 @code{TARGET_LIBGCC_FLOATING_MODE_SUPPORTED_P}; for @code{_Float64x}, it \n\
3515 returns the first of @code{XFmode} and @code{TFmode} that exists and \n\
3516 satisfies the same requirements; for other types, it returns \n\
3517 @code{opt_scalar_float_mode ()}. The hook is only called for values\n\
3518 of @var{n} and @var{extended} that are valid according to\n\
3519 ISO/IEC TS 18661-3:2015; that is, @var{n} is one of 32, 64, 128, or,\n\
3520 if @var{extended} is false, 16 or greater than 128 and a multiple of 32.",
3521 opt_scalar_float_mode, (int n, bool extended),
3522 default_floatn_mode)
3526 "Define this to return true if the @code{_Float@var{n}} and\n\
3527 @code{_Float@var{n}x} built-in functions should implicitly enable the\n\
3528 built-in function without the @code{__builtin_} prefix in addition to the\n\
3529 normal built-in function with the @code{__builtin_} prefix. The default is\n\
3530 to only enable built-in functions without the @code{__builtin_} prefix for\n\
3531 the GNU C langauge. In strict ANSI/ISO mode, the built-in function without\n\
3532 the @code{__builtin_} prefix is not enabled. The argument @code{FUNC} is the\n\
3533 @code{enum built_in_function} id of the function to be enabled.",
3535 default_floatn_builtin_p)
3537 /* Compute cost of moving data from a register of class FROM to one of
3540 (register_move_cost,
3541 "This target hook should return the cost of moving data of mode @var{mode}\n\
3542 from a register in class @var{from} to one in class @var{to}. The classes\n\
3543 are expressed using the enumeration values such as @code{GENERAL_REGS}.\n\
3544 A value of 2 is the default; other values are interpreted relative to\n\
3547 It is not required that the cost always equal 2 when @var{from} is the\n\
3548 same as @var{to}; on some machines it is expensive to move between\n\
3549 registers if they are not general registers.\n\
3551 If reload sees an insn consisting of a single @code{set} between two\n\
3552 hard registers, and if @code{TARGET_REGISTER_MOVE_COST} applied to their\n\
3553 classes returns a value of 2, reload does not check to ensure that the\n\
3554 constraints of the insn are met. Setting a cost of other than 2 will\n\
3555 allow reload to verify that the constraints are met. You should do this\n\
3556 if the @samp{mov@var{m}} pattern's constraints do not allow such copying.\n\
3558 The default version of this function returns 2.",
3559 int, (machine_mode mode, reg_class_t from, reg_class_t to),
3560 default_register_move_cost)
3562 /* Compute cost of moving registers to/from memory. */
3563 /* ??? Documenting the argument types for this hook requires a GFDL
3564 license grant. Also, the documentation uses a different name for RCLASS. */
3567 "This target hook should return the cost of moving data of mode @var{mode}\n\
3568 between a register of class @var{rclass} and memory; @var{in} is @code{false}\n\
3569 if the value is to be written to memory, @code{true} if it is to be read in.\n\
3570 This cost is relative to those in @code{TARGET_REGISTER_MOVE_COST}.\n\
3571 If moving between registers and memory is more expensive than between two\n\
3572 registers, you should add this target hook to express the relative cost.\n\
3574 If you do not add this target hook, GCC uses a default cost of 4 plus\n\
3575 the cost of copying via a secondary reload register, if one is\n\
3576 needed. If your machine requires a secondary reload register to copy\n\
3577 between memory and a register of @var{rclass} but the reload mechanism is\n\
3578 more complex than copying via an intermediate, use this target hook to\n\
3579 reflect the actual cost of the move.\n\
3581 GCC defines the function @code{memory_move_secondary_cost} if\n\
3582 secondary reloads are needed. It computes the costs due to copying via\n\
3583 a secondary register. If your machine copies from memory using a\n\
3584 secondary register in the conventional way but the default base value of\n\
3585 4 is not correct for your machine, use this target hook to add some other\n\
3586 value to the result of that function. The arguments to that function\n\
3587 are the same as to this target hook.",
3588 int, (machine_mode mode, reg_class_t rclass, bool in),
3589 default_memory_move_cost)
3592 (use_by_pieces_infrastructure_p,
3593 "GCC will attempt several strategies when asked to copy between\n\
3594 two areas of memory, or to set, clear or store to memory, for example\n\
3595 when copying a @code{struct}. The @code{by_pieces} infrastructure\n\
3596 implements such memory operations as a sequence of load, store or move\n\
3597 insns. Alternate strategies are to expand the\n\
3598 @code{cpymem} or @code{setmem} optabs, to emit a library call, or to emit\n\
3599 unit-by-unit, loop-based operations.\n\
3601 This target hook should return true if, for a memory operation with a\n\
3602 given @var{size} and @var{alignment}, using the @code{by_pieces}\n\
3603 infrastructure is expected to result in better code generation.\n\
3604 Both @var{size} and @var{alignment} are measured in terms of storage\n\
3607 The parameter @var{op} is one of: @code{CLEAR_BY_PIECES},\n\
3608 @code{MOVE_BY_PIECES}, @code{SET_BY_PIECES}, @code{STORE_BY_PIECES} or\n\
3609 @code{COMPARE_BY_PIECES}. These describe the type of memory operation\n\
3610 under consideration.\n\
3612 The parameter @var{speed_p} is true if the code is currently being\n\
3613 optimized for speed rather than size.\n\
3615 Returning true for higher values of @var{size} can improve code generation\n\
3616 for speed if the target does not provide an implementation of the\n\
3617 @code{cpymem} or @code{setmem} standard names, if the @code{cpymem} or\n\
3618 @code{setmem} implementation would be more expensive than a sequence of\n\
3619 insns, or if the overhead of a library call would dominate that of\n\
3620 the body of the memory operation.\n\
3622 Returning true for higher values of @code{size} may also cause an increase\n\
3623 in code size, for example where the number of insns emitted to perform a\n\
3624 move would be greater than that of a library call.",
3625 bool, (unsigned HOST_WIDE_INT size, unsigned int alignment,
3626 enum by_pieces_operation op, bool speed_p),
3627 default_use_by_pieces_infrastructure_p)
3630 (compare_by_pieces_branch_ratio,
3631 "When expanding a block comparison in MODE, gcc can try to reduce the\n\
3632 number of branches at the expense of more memory operations. This hook\n\
3633 allows the target to override the default choice. It should return the\n\
3634 factor by which branches should be reduced over the plain expansion with\n\
3635 one comparison per @var{mode}-sized piece. A port can also prevent a\n\
3636 particular mode from being used for block comparisons by returning a\n\
3637 negative number from this hook.",
3638 int, (machine_mode mode),
3639 default_compare_by_pieces_branch_ratio)
3642 (slow_unaligned_access,
3643 "This hook returns true if memory accesses described by the\n\
3644 @var{mode} and @var{alignment} parameters have a cost many times greater\n\
3645 than aligned accesses, for example if they are emulated in a trap handler.\n\
3646 This hook is invoked only for unaligned accesses, i.e.@: when\n\
3647 @code{@var{alignment} < GET_MODE_ALIGNMENT (@var{mode})}.\n\
3649 When this hook returns true, the compiler will act as if\n\
3650 @code{STRICT_ALIGNMENT} were true when generating code for block\n\
3651 moves. This can cause significantly more instructions to be produced.\n\
3652 Therefore, do not make this hook return true if unaligned accesses only\n\
3653 add a cycle or two to the time for a memory access.\n\
3655 The hook must return true whenever @code{STRICT_ALIGNMENT} is true.\n\
3656 The default implementation returns @code{STRICT_ALIGNMENT}.",
3657 bool, (machine_mode mode, unsigned int align),
3658 default_slow_unaligned_access)
3662 "Return true if the optimizers should use optab @var{op} with\n\
3663 modes @var{mode1} and @var{mode2} for optimization type @var{opt_type}.\n\
3664 The optab is known to have an associated @file{.md} instruction\n\
3665 whose C condition is true. @var{mode2} is only meaningful for conversion\n\
3666 optabs; for direct optabs it is a copy of @var{mode1}.\n\
3668 For example, when called with @var{op} equal to @code{rint_optab} and\n\
3669 @var{mode1} equal to @code{DFmode}, the hook should say whether the\n\
3670 optimizers should use optab @code{rintdf2}.\n\
3672 The default hook returns true for all inputs.",
3673 bool, (int op, machine_mode mode1, machine_mode mode2,
3674 optimization_type opt_type),
3675 default_optab_supported_p)
3677 /* True for MODE if the target expects that registers in this mode will
3678 be allocated to registers in a small register class. The compiler is
3679 allowed to use registers explicitly used in the rtl as spill registers
3680 but it should prevent extending the lifetime of these registers. */
3682 (small_register_classes_for_mode_p,
3683 "Define this to return nonzero for machine modes for which the port has\n\
3684 small register classes. If this target hook returns nonzero for a given\n\
3685 @var{mode}, the compiler will try to minimize the lifetime of registers\n\
3686 in @var{mode}. The hook may be called with @code{VOIDmode} as argument.\n\
3687 In this case, the hook is expected to return nonzero if it returns nonzero\n\
3690 On some machines, it is risky to let hard registers live across arbitrary\n\
3691 insns. Typically, these machines have instructions that require values\n\
3692 to be in specific registers (like an accumulator), and reload will fail\n\
3693 if the required hard register is used for another purpose across such an\n\
3696 Passes before reload do not know which hard registers will be used\n\
3697 in an instruction, but the machine modes of the registers set or used in\n\
3698 the instruction are already known. And for some machines, register\n\
3699 classes are small for, say, integer registers but not for floating point\n\
3700 registers. For example, the AMD x86-64 architecture requires specific\n\
3701 registers for the legacy x86 integer instructions, but there are many\n\
3702 SSE registers for floating point operations. On such targets, a good\n\
3703 strategy may be to return nonzero from this hook for @code{INTEGRAL_MODE_P}\n\
3704 machine modes but zero for the SSE register classes.\n\
3706 The default version of this hook returns false for any mode. It is always\n\
3707 safe to redefine this hook to return with a nonzero value. But if you\n\
3708 unnecessarily define it, you will reduce the amount of optimizations\n\
3709 that can be performed in some cases. If you do not define this hook\n\
3710 to return a nonzero value when it is required, the compiler will run out\n\
3711 of spill registers and print a fatal error message.",
3712 bool, (machine_mode mode),
3713 hook_bool_mode_false)
3715 /* Register number for a flags register. Only needs to be defined if the
3716 target is constrainted to use post-reload comparison elimination. */
3719 "If the target has a dedicated flags register, and it needs to use the\n\
3720 post-reload comparison elimination pass, or the delay slot filler pass,\n\
3721 then this value should be set appropriately.",
3722 unsigned int, INVALID_REGNUM)
3724 /* Compute a (partial) cost for rtx X. Return true if the complete
3725 cost has been computed, and false if subexpressions should be
3726 scanned. In either case, *TOTAL contains the cost result. */
3727 /* Note that OUTER_CODE ought to be RTX_CODE, but that's
3728 not necessarily defined at this point. */
3731 "This target hook describes the relative costs of RTL expressions.\n\
3733 The cost may depend on the precise form of the expression, which is\n\
3734 available for examination in @var{x}, and the fact that @var{x} appears\n\
3735 as operand @var{opno} of an expression with rtx code @var{outer_code}.\n\
3736 That is, the hook can assume that there is some rtx @var{y} such\n\
3737 that @samp{GET_CODE (@var{y}) == @var{outer_code}} and such that\n\
3738 either (a) @samp{XEXP (@var{y}, @var{opno}) == @var{x}} or\n\
3739 (b) @samp{XVEC (@var{y}, @var{opno})} contains @var{x}.\n\
3741 @var{mode} is @var{x}'s machine mode, or for cases like @code{const_int} that\n\
3742 do not have a mode, the mode in which @var{x} is used.\n\
3744 In implementing this hook, you can use the construct\n\
3745 @code{COSTS_N_INSNS (@var{n})} to specify a cost equal to @var{n} fast\n\
3748 On entry to the hook, @code{*@var{total}} contains a default estimate\n\
3749 for the cost of the expression. The hook should modify this value as\n\
3750 necessary. Traditionally, the default costs are @code{COSTS_N_INSNS (5)}\n\
3751 for multiplications, @code{COSTS_N_INSNS (7)} for division and modulus\n\
3752 operations, and @code{COSTS_N_INSNS (1)} for all other operations.\n\
3754 When optimizing for code size, i.e.@: when @code{speed} is\n\
3755 false, this target hook should be used to estimate the relative\n\
3756 size cost of an expression, again relative to @code{COSTS_N_INSNS}.\n\
3758 The hook returns true when all subexpressions of @var{x} have been\n\
3759 processed, and false when @code{rtx_cost} should recurse.",
3760 bool, (rtx x, machine_mode mode, int outer_code, int opno, int *total, bool speed),
3761 hook_bool_rtx_mode_int_int_intp_bool_false)
3763 /* Compute the cost of X, used as an address. Never called with
3764 invalid addresses. */
3767 "This hook computes the cost of an addressing mode that contains\n\
3768 @var{address}. If not defined, the cost is computed from\n\
3769 the @var{address} expression and the @code{TARGET_RTX_COST} hook.\n\
3771 For most CISC machines, the default cost is a good approximation of the\n\
3772 true cost of the addressing mode. However, on RISC machines, all\n\
3773 instructions normally have the same length and execution time. Hence\n\
3774 all addresses will have equal costs.\n\
3776 In cases where more than one form of an address is known, the form with\n\
3777 the lowest cost will be used. If multiple forms have the same, lowest,\n\
3778 cost, the one that is the most complex will be used.\n\
3780 For example, suppose an address that is equal to the sum of a register\n\
3781 and a constant is used twice in the same basic block. When this macro\n\
3782 is not defined, the address will be computed in a register and memory\n\
3783 references will be indirect through that register. On machines where\n\
3784 the cost of the addressing mode containing the sum is no higher than\n\
3785 that of a simple indirect reference, this will produce an additional\n\
3786 instruction and possibly require an additional register. Proper\n\
3787 specification of this macro eliminates this overhead for such machines.\n\
3789 This hook is never called with an invalid address.\n\
3791 On machines where an address involving more than one register is as\n\
3792 cheap as an address computation involving only one register, defining\n\
3793 @code{TARGET_ADDRESS_COST} to reflect this can cause two registers to\n\
3794 be live over a region of code where only one would have been if\n\
3795 @code{TARGET_ADDRESS_COST} were not defined in that manner. This effect\n\
3796 should be considered in the definition of this macro. Equivalent costs\n\
3797 should probably only be given to addresses with different numbers of\n\
3798 registers on machines with lots of registers.",
3799 int, (rtx address, machine_mode mode, addr_space_t as, bool speed),
3800 default_address_cost)
3802 /* Compute a cost for INSN. */
3805 "This target hook describes the relative costs of RTL instructions.\n\
3807 In implementing this hook, you can use the construct\n\
3808 @code{COSTS_N_INSNS (@var{n})} to specify a cost equal to @var{n} fast\n\
3811 When optimizing for code size, i.e.@: when @code{speed} is\n\
3812 false, this target hook should be used to estimate the relative\n\
3813 size cost of an expression, again relative to @code{COSTS_N_INSNS}.",
3814 int, (rtx_insn *insn, bool speed), NULL)
3816 /* Give a cost, in RTX Costs units, for an edge. Like BRANCH_COST, but with
3817 well defined units. */
3819 (max_noce_ifcvt_seq_cost,
3820 "This hook returns a value in the same units as @code{TARGET_RTX_COSTS},\n\
3821 giving the maximum acceptable cost for a sequence generated by the RTL\n\
3822 if-conversion pass when conditional execution is not available.\n\
3823 The RTL if-conversion pass attempts to convert conditional operations\n\
3824 that would require a branch to a series of unconditional operations and\n\
3825 @code{mov@var{mode}cc} insns. This hook returns the maximum cost of the\n\
3826 unconditional instructions and the @code{mov@var{mode}cc} insns.\n\
3827 RTL if-conversion is cancelled if the cost of the converted sequence\n\
3828 is greater than the value returned by this hook.\n\
3830 @code{e} is the edge between the basic block containing the conditional\n\
3831 branch to the basic block which would be executed if the condition\n\
3834 The default implementation of this hook uses the\n\
3835 @code{max-rtl-if-conversion-[un]predictable} parameters if they are set,\n\
3836 and uses a multiple of @code{BRANCH_COST} otherwise.",
3837 unsigned int, (edge e),
3838 default_max_noce_ifcvt_seq_cost)
3840 /* Return true if the given instruction sequence is a good candidate
3841 as a replacement for the if-convertible sequence. */
3843 (noce_conversion_profitable_p,
3844 "This hook returns true if the instruction sequence @code{seq} is a good\n\
3845 candidate as a replacement for the if-convertible sequence described in\n\
3847 bool, (rtx_insn *seq, struct noce_if_info *if_info),
3848 default_noce_conversion_profitable_p)
3851 (estimated_poly_value,
3852 "Return an estimate of the runtime value of @var{val}, for use in\n\
3853 things like cost calculations or profiling frequencies. The default\n\
3854 implementation returns the lowest possible value of @var{val}.",
3855 HOST_WIDE_INT, (poly_int64 val),
3856 default_estimated_poly_value)
3858 /* Permit speculative instructions in delay slots during delayed-branch
3861 (no_speculation_in_delay_slots_p,
3862 "This predicate controls the use of the eager delay slot filler to disallow\n\
3863 speculatively executed instructions being placed in delay slots. Targets\n\
3864 such as certain MIPS architectures possess both branches with and without\n\
3865 delay slots. As the eager delay slot filler can decrease performance,\n\
3866 disabling it is beneficial when ordinary branches are available. Use of\n\
3867 delay slot branches filled using the basic filler is often still desirable\n\
3868 as the delay slot can hide a pipeline bubble.", bool, (void),
3869 hook_bool_void_false)
3871 /* Return where to allocate pseudo for a given hard register initial value. */
3873 (allocate_initial_value,
3875 When the initial value of a hard register has been copied in a pseudo\n\
3876 register, it is often not necessary to actually allocate another register\n\
3877 to this pseudo register, because the original hard register or a stack slot\n\
3878 it has been saved into can be used. @code{TARGET_ALLOCATE_INITIAL_VALUE}\n\
3879 is called at the start of register allocation once for each hard register\n\
3880 that had its initial value copied by using\n\
3881 @code{get_func_hard_reg_initial_val} or @code{get_hard_reg_initial_val}.\n\
3882 Possible values are @code{NULL_RTX}, if you don't want\n\
3883 to do any special allocation, a @code{REG} rtx---that would typically be\n\
3884 the hard register itself, if it is known not to be clobbered---or a\n\
3886 If you are returning a @code{MEM}, this is only a hint for the allocator;\n\
3887 it might decide to use another register anyways.\n\
3888 You may use @code{current_function_is_leaf} or \n\
3889 @code{REG_N_SETS} in the hook to determine if the hard\n\
3890 register in question will not be clobbered.\n\
3891 The default value of this hook is @code{NULL}, which disables any special\n\
3893 rtx, (rtx hard_reg), NULL)
3895 /* Return nonzero if evaluating UNSPEC X might cause a trap.
3896 FLAGS has the same meaning as in rtlanal.c: may_trap_p_1. */
3899 "This target hook returns nonzero if @var{x}, an @code{unspec} or\n\
3900 @code{unspec_volatile} operation, might cause a trap. Targets can use\n\
3901 this hook to enhance precision of analysis for @code{unspec} and\n\
3902 @code{unspec_volatile} operations. You may call @code{may_trap_p_1}\n\
3903 to analyze inner elements of @var{x} in which case @var{flags} should be\n\
3905 int, (const_rtx x, unsigned flags),
3906 default_unspec_may_trap_p)
3908 /* Given a register, this hook should return a parallel of registers
3909 to represent where to find the register pieces. Define this hook
3910 if the register and its mode are represented in Dwarf in
3911 non-contiguous locations, or if the register should be
3912 represented in more than one register in Dwarf. Otherwise, this
3913 hook should return NULL_RTX. */
3915 (dwarf_register_span,
3916 "Given a register, this hook should return a parallel of registers to\n\
3917 represent where to find the register pieces. Define this hook if the\n\
3918 register and its mode are represented in Dwarf in non-contiguous\n\
3919 locations, or if the register should be represented in more than one\n\
3920 register in Dwarf. Otherwise, this hook should return @code{NULL_RTX}.\n\
3921 If not defined, the default is to return @code{NULL_RTX}.",
3925 /* Given a register return the mode of the corresponding DWARF frame
3928 (dwarf_frame_reg_mode,
3929 "Given a register, this hook should return the mode which the\n\
3930 corresponding Dwarf frame register should have. This is normally\n\
3931 used to return a smaller mode than the raw mode to prevent call\n\
3932 clobbered parts of a register altering the frame register size",
3933 machine_mode, (int regno),
3934 default_dwarf_frame_reg_mode)
3936 /* If expand_builtin_init_dwarf_reg_sizes needs to fill in table
3937 entries not corresponding directly to registers below
3938 FIRST_PSEUDO_REGISTER, this hook should generate the necessary
3939 code, given the address of the table. */
3941 (init_dwarf_reg_sizes_extra,
3942 "If some registers are represented in Dwarf-2 unwind information in\n\
3943 multiple pieces, define this hook to fill in information about the\n\
3944 sizes of those pieces in the table used by the unwinder at runtime.\n\
3945 It will be called by @code{expand_builtin_init_dwarf_reg_sizes} after\n\
3946 filling in a single size corresponding to each hard register;\n\
3947 @var{address} is the address of the table.",
3948 void, (tree address),
3951 /* Fetch the fixed register(s) which hold condition codes, for
3952 targets where it makes sense to look for duplicate assignments to
3953 the condition codes. This should return true if there is such a
3954 register, false otherwise. The arguments should be set to the
3955 fixed register numbers. Up to two condition code registers are
3956 supported. If there is only one for this target, the int pointed
3957 at by the second argument should be set to -1. */
3959 (fixed_condition_code_regs,
3960 "On targets which do not use @code{(cc0)}, and which use a hard\n\
3961 register rather than a pseudo-register to hold condition codes, the\n\
3962 regular CSE passes are often not able to identify cases in which the\n\
3963 hard register is set to a common value. Use this hook to enable a\n\
3964 small pass which optimizes such cases. This hook should return true\n\
3965 to enable this pass, and it should set the integers to which its\n\
3966 arguments point to the hard register numbers used for condition codes.\n\
3967 When there is only one such register, as is true on most systems, the\n\
3968 integer pointed to by @var{p2} should be set to\n\
3969 @code{INVALID_REGNUM}.\n\
3971 The default version of this hook returns false.",
3972 bool, (unsigned int *p1, unsigned int *p2),
3973 hook_bool_uintp_uintp_false)
3975 /* If two condition code modes are compatible, return a condition
3976 code mode which is compatible with both, such that a comparison
3977 done in the returned mode will work for both of the original
3978 modes. If the condition code modes are not compatible, return
3981 (cc_modes_compatible,
3982 "On targets which use multiple condition code modes in class\n\
3983 @code{MODE_CC}, it is sometimes the case that a comparison can be\n\
3984 validly done in more than one mode. On such a system, define this\n\
3985 target hook to take two mode arguments and to return a mode in which\n\
3986 both comparisons may be validly done. If there is no such mode,\n\
3987 return @code{VOIDmode}.\n\
3989 The default version of this hook checks whether the modes are the\n\
3990 same. If they are, it returns that mode. If they are different, it\n\
3991 returns @code{VOIDmode}.",
3992 machine_mode, (machine_mode m1, machine_mode m2),
3993 default_cc_modes_compatible)
3995 /* Do machine-dependent code transformations. Called just before
3996 delayed-branch scheduling. */
3998 (machine_dependent_reorg,
3999 "If non-null, this hook performs a target-specific pass over the\n\
4000 instruction stream. The compiler will run it at all optimization levels,\n\
4001 just before the point at which it normally does delayed-branch scheduling.\n\
4003 The exact purpose of the hook varies from target to target. Some use\n\
4004 it to do transformations that are necessary for correctness, such as\n\
4005 laying out in-function constant pools or avoiding hardware hazards.\n\
4006 Others use it as an opportunity to do some machine-dependent optimizations.\n\
4008 You need not implement the hook if it has nothing to do. The default\n\
4009 definition is null.",
4012 /* Create the __builtin_va_list type. */
4014 (build_builtin_va_list,
4015 "This hook returns a type node for @code{va_list} for the target.\n\
4016 The default version of the hook returns @code{void*}.",
4018 std_build_builtin_va_list)
4020 /* Enumerate the va list variants. */
4023 "This target hook is used in function @code{c_common_nodes_and_builtins}\n\
4024 to iterate through the target specific builtin types for va_list. The\n\
4025 variable @var{idx} is used as iterator. @var{pname} has to be a pointer\n\
4026 to a @code{const char *} and @var{ptree} a pointer to a @code{tree} typed\n\
4028 The arguments @var{pname} and @var{ptree} are used to store the result of\n\
4029 this macro and are set to the name of the va_list builtin type and its\n\
4031 If the return value of this macro is zero, then there is no more element.\n\
4032 Otherwise the @var{IDX} should be increased for the next call of this\n\
4033 macro to iterate through all types.",
4034 int, (int idx, const char **pname, tree *ptree),
4037 /* Get the cfun/fndecl calling abi __builtin_va_list type. */
4040 "This hook returns the va_list type of the calling convention specified by\n\
4042 The default version of this hook returns @code{va_list_type_node}.",
4043 tree, (tree fndecl),
4046 /* Get the __builtin_va_list type dependent on input type. */
4048 (canonical_va_list_type,
4049 "This hook returns the va_list type of the calling convention specified by the\n\
4050 type of @var{type}. If @var{type} is not a valid va_list type, it returns\n\
4053 std_canonical_va_list_type)
4055 /* ??? Documenting this hook requires a GFDL license grant. */
4057 (expand_builtin_va_start,
4058 "Expand the @code{__builtin_va_start} builtin.",
4059 void, (tree valist, rtx nextarg), NULL)
4061 /* Gimplifies a VA_ARG_EXPR. */
4063 (gimplify_va_arg_expr,
4064 "This hook performs target-specific gimplification of\n\
4065 @code{VA_ARG_EXPR}. The first two parameters correspond to the\n\
4066 arguments to @code{va_arg}; the latter two are as in\n\
4067 @code{gimplify.c:gimplify_expr}.",
4068 tree, (tree valist, tree type, gimple_seq *pre_p, gimple_seq *post_p),
4069 std_gimplify_va_arg_expr)
4071 /* Validity-checking routines for PCH files, target-specific.
4072 get_pch_validity returns a pointer to the data to be stored,
4073 and stores the size in its argument. pch_valid_p gets the same
4074 information back and returns NULL if the PCH is valid,
4075 or an error message if not. */
4078 "This hook returns a pointer to the data needed by\n\
4079 @code{TARGET_PCH_VALID_P} and sets\n\
4080 @samp{*@var{sz}} to the size of the data in bytes.",
4081 void *, (size_t *sz),
4082 default_get_pch_validity)
4086 "This hook checks whether the options used to create a PCH file are\n\
4087 compatible with the current settings. It returns @code{NULL}\n\
4088 if so and a suitable error message if not. Error messages will\n\
4089 be presented to the user and must be localized using @samp{_(@var{msg})}.\n\
4091 @var{data} is the data that was returned by @code{TARGET_GET_PCH_VALIDITY}\n\
4092 when the PCH file was created and @var{sz} is the size of that data in bytes.\n\
4093 It's safe to assume that the data was created by the same version of the\n\
4094 compiler, so no format checking is needed.\n\
4096 The default definition of @code{default_pch_valid_p} should be\n\
4097 suitable for most targets.",
4098 const char *, (const void *data, size_t sz),
4099 default_pch_valid_p)
4103 "Called before writing out a PCH file. If the target has some\n\
4104 garbage-collected data that needs to be in a particular state on PCH loads,\n\
4105 it can use this hook to enforce that state. Very few targets need\n\
4106 to do anything here.",
4110 /* If nonnull, this function checks whether a PCH file with the
4111 given set of target flags can be used. It returns NULL if so,
4112 otherwise it returns an error message. */
4114 (check_pch_target_flags,
4115 "If this hook is nonnull, the default implementation of\n\
4116 @code{TARGET_PCH_VALID_P} will use it to check for compatible values\n\
4117 of @code{target_flags}. @var{pch_flags} specifies the value that\n\
4118 @code{target_flags} had when the PCH file was created. The return\n\
4119 value is the same as for @code{TARGET_PCH_VALID_P}.",
4120 const char *, (int pch_flags), NULL)
4122 /* True if the compiler should give an enum type only as many
4123 bytes as it takes to represent the range of possible values of
4126 (default_short_enums,
4127 "This target hook should return true if the compiler should give an\n\
4128 @code{enum} type only as many bytes as it takes to represent the range\n\
4129 of possible values of that type. It should return false if all\n\
4130 @code{enum} types should be allocated like @code{int}.\n\
4132 The default is to return false.",
4134 hook_bool_void_false)
4136 /* This target hook returns an rtx that is used to store the address
4137 of the current frame into the built-in setjmp buffer. */
4139 (builtin_setjmp_frame_value,
4140 "This target hook should return an rtx that is used to store\n\
4141 the address of the current frame into the built in @code{setjmp} buffer.\n\
4142 The default value, @code{virtual_stack_vars_rtx}, is correct for most\n\
4143 machines. One reason you may need to define this target hook is if\n\
4144 @code{hard_frame_pointer_rtx} is the appropriate value on your machine.",
4146 default_builtin_setjmp_frame_value)
4148 /* This target hook should manipulate the outputs, inputs, constraints,
4149 and clobbers the port wishes for pre-processing the asm. */
4152 "This target hook may add @dfn{clobbers} to @var{clobbers} and\n\
4153 @var{clobbered_regs} for any hard regs the port wishes to automatically\n\
4154 clobber for an asm. The @var{outputs} and @var{inputs} may be inspected\n\
4155 to avoid clobbering a register that is already used by the asm.\n\
4157 It may modify the @var{outputs}, @var{inputs}, and @var{constraints}\n\
4158 as necessary for other pre-processing. In this case the return value is\n\
4159 a sequence of insns to emit after the asm.",
4161 (vec<rtx>& outputs, vec<rtx>& inputs, vec<const char *>& constraints,
4162 vec<rtx>& clobbers, HARD_REG_SET& clobbered_regs),
4165 /* This target hook allows the backend to specify a calling convention
4166 in the debug information. This function actually returns an
4167 enum dwarf_calling_convention, but because of forward declarations
4168 and not wanting to include dwarf2.h everywhere target.h is included
4169 the function is being declared as an int. */
4171 (dwarf_calling_convention,
4172 "Define this to enable the dwarf attribute @code{DW_AT_calling_convention} to\n\
4173 be emitted for each function. Instead of an integer return the enum\n\
4174 value for the @code{DW_CC_} tag.",
4175 int, (const_tree function),
4176 hook_int_const_tree_0)
4178 /* This target hook allows the backend to emit frame-related insns that
4179 contain UNSPECs or UNSPEC_VOLATILEs. The call frame debugging info
4180 engine will invoke it on insns of the form
4181 (set (reg) (unspec [...] UNSPEC_INDEX))
4183 (set (reg) (unspec_volatile [...] UNSPECV_INDEX))
4184 to let the backend emit the call frame instructions. */
4186 (dwarf_handle_frame_unspec,
4187 "This target hook allows the backend to emit frame-related insns that\n\
4188 contain UNSPECs or UNSPEC_VOLATILEs. The DWARF 2 call frame debugging\n\
4189 info engine will invoke it on insns of the form\n\
4191 (set (reg) (unspec [@dots{}] UNSPEC_INDEX))\n\
4192 @end smallexample\n\
4195 (set (reg) (unspec_volatile [@dots{}] UNSPECV_INDEX)).\n\
4196 @end smallexample\n\
4197 to let the backend emit the call frame instructions. @var{label} is\n\
4198 the CFI label attached to the insn, @var{pattern} is the pattern of\n\
4199 the insn and @var{index} is @code{UNSPEC_INDEX} or @code{UNSPECV_INDEX}.",
4200 void, (const char *label, rtx pattern, int index), NULL)
4203 (dwarf_poly_indeterminate_value,
4204 "Express the value of @code{poly_int} indeterminate @var{i} as a DWARF\n\
4205 expression, with @var{i} counting from 1. Return the number of a DWARF\n\
4206 register @var{R} and set @samp{*@var{factor}} and @samp{*@var{offset}} such\n\
4207 that the value of the indeterminate is:\n\
4209 value_of(@var{R}) / @var{factor} - @var{offset}\n\
4210 @end smallexample\n\
4212 A target only needs to define this hook if it sets\n\
4213 @samp{NUM_POLY_INT_COEFFS} to a value greater than 1.",
4214 unsigned int, (unsigned int i, unsigned int *factor, int *offset),
4215 default_dwarf_poly_indeterminate_value)
4217 /* ??? Documenting this hook requires a GFDL license grant. */
4219 (stdarg_optimize_hook,
4220 "Perform architecture specific checking of statements gimplified\
4221 from @code{VA_ARG_EXPR}. @var{stmt} is the statement. Returns true if\
4222 the statement doesn't need to be checked for @code{va_list} references.",
4223 bool, (struct stdarg_info *ai, const gimple *stmt), NULL)
4225 /* This target hook allows the operating system to override the DECL
4226 that represents the external variable that contains the stack
4227 protection guard variable. The type of this DECL is ptr_type_node. */
4229 (stack_protect_guard,
4230 "This hook returns a @code{DECL} node for the external variable to use\n\
4231 for the stack protection guard. This variable is initialized by the\n\
4232 runtime to some random value and is used to initialize the guard value\n\
4233 that is placed at the top of the local stack frame. The type of this\n\
4234 variable must be @code{ptr_type_node}.\n\
4236 The default version of this hook creates a variable called\n\
4237 @samp{__stack_chk_guard}, which is normally defined in @file{libgcc2.c}.",
4239 default_stack_protect_guard)
4241 /* This target hook allows the operating system to override the CALL_EXPR
4242 that is invoked when a check vs the guard variable fails. */
4244 (stack_protect_fail,
4245 "This hook returns a @code{CALL_EXPR} that alerts the runtime that the\n\
4246 stack protect guard variable has been modified. This expression should\n\
4247 involve a call to a @code{noreturn} function.\n\
4249 The default version of this hook invokes a function called\n\
4250 @samp{__stack_chk_fail}, taking no arguments. This function is\n\
4251 normally defined in @file{libgcc2.c}.",
4253 default_external_stack_protect_fail)
4255 /* This target hook allows the operating system to disable the default stack
4256 protector runtime support. */
4258 (stack_protect_runtime_enabled_p,
4259 "Returns true if the target wants GCC's default stack protect runtime support,\
4260 otherwise return false. The default implementation always returns true.",
4262 hook_bool_void_true)
4265 (have_speculation_safe_value,
4266 "This hook is used to determine the level of target support for\n\
4267 @code{__builtin_speculation_safe_value}. If called with an argument\n\
4268 of false, it returns true if the target has been modified to support\n\
4269 this builtin. If called with an argument of true, it returns true\n\
4270 if the target requires active mitigation execution might be speculative.\n\
4272 The default implementation returns false if the target does not define\n\
4273 a pattern named @code{speculation_barrier}. Else it returns true\n\
4274 for the first case and whether the pattern is enabled for the current\n\
4275 compilation for the second case.\n\
4277 For targets that have no processors that can execute instructions\n\
4278 speculatively an alternative implemenation of this hook is available:\n\
4279 simply redefine this hook to @code{speculation_safe_value_not_needed}\n\
4280 along with your other target hooks.",
4281 bool, (bool active), default_have_speculation_safe_value)
4284 (speculation_safe_value,
4285 "This target hook can be used to generate a target-specific code\n\
4286 sequence that implements the @code{__builtin_speculation_safe_value}\n\
4287 built-in function. The function must always return @var{val} in\n\
4288 @var{result} in mode @var{mode} when the cpu is not executing\n\
4289 speculatively, but must never return that when speculating until it\n\
4290 is known that the speculation will not be unwound. The hook supports\n\
4291 two primary mechanisms for implementing the requirements. The first\n\
4292 is to emit a speculation barrier which forces the processor to wait\n\
4293 until all prior speculative operations have been resolved; the second\n\
4294 is to use a target-specific mechanism that can track the speculation\n\
4295 state and to return @var{failval} if it can determine that\n\
4296 speculation must be unwound at a later time.\n\
4298 The default implementation simply copies @var{val} to @var{result} and\n\
4299 emits a @code{speculation_barrier} instruction if that is defined.",
4300 rtx, (machine_mode mode, rtx result, rtx val, rtx failval),
4301 default_speculation_safe_value)
4305 "Return true if we can predict it is possible to use a low-overhead loop\n\
4306 for a particular loop. The parameter @var{loop} is a pointer to the loop.\n\
4307 This target hook is required only when the target supports low-overhead\n\
4308 loops, and will help ivopts to make some decisions.\n\
4309 The default version of this hook returns false.",
4310 bool, (class loop *loop),
4311 default_predict_doloop_p)
4314 (have_count_reg_decr_p,
4315 "Return true if the target supports hardware count register for decrement\n\
4317 The default value is false.",
4321 (doloop_cost_for_generic,
4322 "One IV candidate dedicated for doloop is introduced in IVOPTs, we can\n\
4323 calculate the computation cost of adopting it to any generic IV use by\n\
4324 function get_computation_cost as before. But for targets which have\n\
4325 hardware count register support for decrement and branch, it may have to\n\
4326 move IV value from hardware count register to general purpose register\n\
4327 while doloop IV candidate is used for generic IV uses. It probably takes\n\
4328 expensive penalty. This hook allows target owners to define the cost for\n\
4329 this especially for generic IV uses.\n\
4330 The default value is zero.",
4334 (doloop_cost_for_address,
4335 "One IV candidate dedicated for doloop is introduced in IVOPTs, we can\n\
4336 calculate the computation cost of adopting it to any address IV use by\n\
4337 function get_computation_cost as before. But for targets which have\n\
4338 hardware count register support for decrement and branch, it may have to\n\
4339 move IV value from hardware count register to general purpose register\n\
4340 while doloop IV candidate is used for address IV uses. It probably takes\n\
4341 expensive penalty. This hook allows target owners to define the cost for\n\
4342 this escpecially for address IV uses.\n\
4343 The default value is zero.",
4348 "Return true if it is possible to use low-overhead loops (@code{doloop_end}\n\
4349 and @code{doloop_begin}) for a particular loop. @var{iterations} gives the\n\
4350 exact number of iterations, or 0 if not known. @var{iterations_max} gives\n\
4351 the maximum number of iterations, or 0 if not known. @var{loop_depth} is\n\
4352 the nesting depth of the loop, with 1 for innermost loops, 2 for loops that\n\
4353 contain innermost loops, and so on. @var{entered_at_top} is true if the\n\
4354 loop is only entered from the top.\n\
4356 This hook is only used if @code{doloop_end} is available. The default\n\
4357 implementation returns true. You can use @code{can_use_doloop_if_innermost}\n\
4358 if the loop must be the innermost, and if there are no other restrictions.",
4359 bool, (const widest_int &iterations, const widest_int &iterations_max,
4360 unsigned int loop_depth, bool entered_at_top),
4361 hook_bool_wint_wint_uint_bool_true)
4363 /* Returns NULL if target supports the insn within a doloop block,
4364 otherwise it returns an error message. */
4366 (invalid_within_doloop,
4368 Take an instruction in @var{insn} and return NULL if it is valid within a\n\
4369 low-overhead loop, otherwise return a string explaining why doloop\n\
4370 could not be applied.\n\
4372 Many targets use special registers for low-overhead looping. For any\n\
4373 instruction that clobbers these this function should return a string indicating\n\
4374 the reason why the doloop could not be applied.\n\
4375 By default, the RTL loop optimizer does not use a present doloop pattern for\n\
4376 loops containing function calls or branch on table instructions.",
4377 const char *, (const rtx_insn *insn),
4378 default_invalid_within_doloop)
4380 /* Returns true for a legitimate combined insn. */
4382 (legitimate_combined_insn,
4383 "Take an instruction in @var{insn} and return @code{false} if the instruction\
4384 is not appropriate as a combination of two or more instructions. The\
4385 default is to accept all instructions.",
4386 bool, (rtx_insn *insn),
4387 hook_bool_rtx_insn_true)
4390 (valid_dllimport_attribute_p,
4391 "@var{decl} is a variable or function with @code{__attribute__((dllimport))}\
4392 specified. Use this hook if the target needs to add extra validation\
4393 checks to @code{handle_dll_attribute}.",
4394 bool, (const_tree decl),
4395 hook_bool_const_tree_true)
4397 /* If non-zero, align constant anchors in CSE to a multiple of this
4401 "On some architectures it can take multiple instructions to synthesize\n\
4402 a constant. If there is another constant already in a register that\n\
4403 is close enough in value then it is preferable that the new constant\n\
4404 is computed from this register using immediate addition or\n\
4405 subtraction. We accomplish this through CSE. Besides the value of\n\
4406 the constant we also add a lower and an upper constant anchor to the\n\
4407 available expressions. These are then queried when encountering new\n\
4408 constants. The anchors are computed by rounding the constant up and\n\
4409 down to a multiple of the value of @code{TARGET_CONST_ANCHOR}.\n\
4410 @code{TARGET_CONST_ANCHOR} should be the maximum positive value\n\
4411 accepted by immediate-add plus one. We currently assume that the\n\
4412 value of @code{TARGET_CONST_ANCHOR} is a power of 2. For example, on\n\
4413 MIPS, where add-immediate takes a 16-bit signed value,\n\
4414 @code{TARGET_CONST_ANCHOR} is set to @samp{0x8000}. The default value\n\
4415 is zero, which disables this optimization.",
4416 unsigned HOST_WIDE_INT, 0)
4418 /* Defines, which target-dependent bits (upper 16) are used by port */
4421 "Validate target specific memory model mask bits. When NULL no target specific\n\
4422 memory model bits are allowed.",
4423 unsigned HOST_WIDE_INT, (unsigned HOST_WIDE_INT val), NULL)
4425 /* Defines an offset bitwise ored into shifted address to get corresponding
4426 Address Sanitizer shadow address, or -1 if Address Sanitizer is not
4427 supported by the target. */
4429 (asan_shadow_offset,
4430 "Return the offset bitwise ored into shifted address to get corresponding\n\
4431 Address Sanitizer shadow memory address. NULL if Address Sanitizer is not\n\
4432 supported by the target.",
4433 unsigned HOST_WIDE_INT, (void),
4436 /* Functions relating to calls - argument passing, returns, etc. */
4437 /* Members of struct call have no special macro prefix. */
4438 HOOK_VECTOR (TARGET_CALLS, calls)
4441 (promote_function_mode,
4442 "Like @code{PROMOTE_MODE}, but it is applied to outgoing function arguments or\n\
4443 function return values. The target hook should return the new mode\n\
4444 and possibly change @code{*@var{punsignedp}} if the promotion should\n\
4445 change signedness. This function is called only for scalar @emph{or\n\
4448 @var{for_return} allows to distinguish the promotion of arguments and\n\
4449 return values. If it is @code{1}, a return value is being promoted and\n\
4450 @code{TARGET_FUNCTION_VALUE} must perform the same promotions done here.\n\
4451 If it is @code{2}, the returned mode should be that of the register in\n\
4452 which an incoming parameter is copied, or the outgoing result is computed;\n\
4453 then the hook should return the same mode as @code{promote_mode}, though\n\
4454 the signedness may be different.\n\
4456 @var{type} can be NULL when promoting function arguments of libcalls.\n\
4458 The default is to not promote arguments and return values. You can\n\
4459 also define the hook to @code{default_promote_function_mode_always_promote}\n\
4460 if you would like to apply the same rules given by @code{PROMOTE_MODE}.",
4461 machine_mode, (const_tree type, machine_mode mode, int *punsignedp,
4462 const_tree funtype, int for_return),
4463 default_promote_function_mode)
4466 (promote_prototypes,
4467 "This target hook returns @code{true} if an argument declared in a\n\
4468 prototype as an integral type smaller than @code{int} should actually be\n\
4469 passed as an @code{int}. In addition to avoiding errors in certain\n\
4470 cases of mismatch, it also makes for better code on certain machines.\n\
4471 The default is to not promote prototypes.",
4472 bool, (const_tree fntype),
4473 hook_bool_const_tree_false)
4477 "This target hook should return the location of the structure value\n\
4478 address (normally a @code{mem} or @code{reg}), or 0 if the address is\n\
4479 passed as an ``invisible'' first argument. Note that @var{fndecl} may\n\
4480 be @code{NULL}, for libcalls. You do not need to define this target\n\
4481 hook if the address is always passed as an ``invisible'' first\n\
4484 On some architectures the place where the structure value address\n\
4485 is found by the called function is not the same place that the\n\
4486 caller put it. This can be due to register windows, or it could\n\
4487 be because the function prologue moves it to a different place.\n\
4488 @var{incoming} is @code{1} or @code{2} when the location is needed in\n\
4489 the context of the called function, and @code{0} in the context of\n\
4492 If @var{incoming} is nonzero and the address is to be found on the\n\
4493 stack, return a @code{mem} which refers to the frame pointer. If\n\
4494 @var{incoming} is @code{2}, the result is being used to fetch the\n\
4495 structure value address at the beginning of a function. If you need\n\
4496 to emit adjusting code, you should do it at this point.",
4497 rtx, (tree fndecl, int incoming),
4498 hook_rtx_tree_int_null)
4501 (omit_struct_return_reg,
4502 "Normally, when a function returns a structure by memory, the address\n\
4503 is passed as an invisible pointer argument, but the compiler also\n\
4504 arranges to return the address from the function like it would a normal\n\
4505 pointer return value. Define this to true if that behavior is\n\
4506 undesirable on your target.",
4511 "This target hook should return a nonzero value to say to return the\n\
4512 function value in memory, just as large structures are always returned.\n\
4513 Here @var{type} will be the data type of the value, and @var{fntype}\n\
4514 will be the type of the function doing the returning, or @code{NULL} for\n\
4517 Note that values of mode @code{BLKmode} must be explicitly handled\n\
4518 by this function. Also, the option @option{-fpcc-struct-return}\n\
4519 takes effect regardless of this macro. On most systems, it is\n\
4520 possible to leave the hook undefined; this causes a default\n\
4521 definition to be used, whose value is the constant 1 for @code{BLKmode}\n\
4522 values, and 0 otherwise.\n\
4524 Do not use this hook to indicate that structures and unions should always\n\
4525 be returned in memory. You should instead use @code{DEFAULT_PCC_STRUCT_RETURN}\n\
4527 bool, (const_tree type, const_tree fntype),
4528 default_return_in_memory)
4532 "This hook should return true if values of type @var{type} are returned\n\
4533 at the most significant end of a register (in other words, if they are\n\
4534 padded at the least significant end). You can assume that @var{type}\n\
4535 is returned in a register; the caller is required to check this.\n\
4537 Note that the register provided by @code{TARGET_FUNCTION_VALUE} must\n\
4538 be able to hold the complete return value. For example, if a 1-, 2-\n\
4539 or 3-byte structure is returned at the most significant end of a\n\
4540 4-byte register, @code{TARGET_FUNCTION_VALUE} should provide an\n\
4541 @code{SImode} rtx.",
4542 bool, (const_tree type),
4543 hook_bool_const_tree_false)
4545 /* Return true if a parameter must be passed by reference. TYPE may
4546 be null if this is a libcall. CA may be null if this query is
4547 from __builtin_va_arg. */
4550 "This target hook should return @code{true} if argument @var{arg} at the\n\
4551 position indicated by @var{cum} should be passed by reference. This\n\
4552 predicate is queried after target independent reasons for being\n\
4553 passed by reference, such as @code{TREE_ADDRESSABLE (@var{arg}.type)}.\n\
4555 If the hook returns true, a copy of that argument is made in memory and a\n\
4556 pointer to the argument is passed instead of the argument itself.\n\
4557 The pointer is passed in whatever way is appropriate for passing a pointer\n\
4560 (cumulative_args_t cum, const function_arg_info &arg),
4561 hook_bool_CUMULATIVE_ARGS_arg_info_false)
4564 (expand_builtin_saveregs,
4565 "If defined, this hook produces the machine-specific code for a call to\n\
4566 @code{__builtin_saveregs}. This code will be moved to the very\n\
4567 beginning of the function, before any parameter access are made. The\n\
4568 return value of this function should be an RTX that contains the value\n\
4569 to use as the return of @code{__builtin_saveregs}.",
4571 default_expand_builtin_saveregs)
4573 /* Returns pretend_argument_size. */
4575 (setup_incoming_varargs,
4576 "This target hook offers an alternative to using\n\
4577 @code{__builtin_saveregs} and defining the hook\n\
4578 @code{TARGET_EXPAND_BUILTIN_SAVEREGS}. Use it to store the anonymous\n\
4579 register arguments into the stack so that all the arguments appear to\n\
4580 have been passed consecutively on the stack. Once this is done, you can\n\
4581 use the standard implementation of varargs that works for machines that\n\
4582 pass all their arguments on the stack.\n\
4584 The argument @var{args_so_far} points to the @code{CUMULATIVE_ARGS} data\n\
4585 structure, containing the values that are obtained after processing the\n\
4586 named arguments. The argument @var{arg} describes the last of these named\n\
4589 The target hook should do two things: first, push onto the stack all the\n\
4590 argument registers @emph{not} used for the named arguments, and second,\n\
4591 store the size of the data thus pushed into the @code{int}-valued\n\
4592 variable pointed to by @var{pretend_args_size}. The value that you\n\
4593 store here will serve as additional offset for setting up the stack\n\
4596 Because you must generate code to push the anonymous arguments at\n\
4597 compile time without knowing their data types,\n\
4598 @code{TARGET_SETUP_INCOMING_VARARGS} is only useful on machines that\n\
4599 have just a single category of argument register and use it uniformly\n\
4600 for all data types.\n\
4602 If the argument @var{second_time} is nonzero, it means that the\n\
4603 arguments of the function are being analyzed for the second time. This\n\
4604 happens for an inline function, which is not actually compiled until the\n\
4605 end of the source file. The hook @code{TARGET_SETUP_INCOMING_VARARGS} should\n\
4606 not generate any instructions in this case.",
4607 void, (cumulative_args_t args_so_far, const function_arg_info &arg,
4608 int *pretend_args_size, int second_time),
4609 default_setup_incoming_varargs)
4612 (load_bounds_for_arg,
4613 "This hook is used by expand pass to emit insn to load bounds of\n\
4614 @var{arg} passed in @var{slot}. Expand pass uses this hook in case\n\
4615 bounds of @var{arg} are not passed in register. If @var{slot} is a\n\
4616 memory, then bounds are loaded as for regular pointer loaded from\n\
4617 memory. If @var{slot} is not a memory then @var{slot_no} is an integer\n\
4618 constant holding number of the target dependent special slot which\n\
4619 should be used to obtain bounds. Hook returns RTX holding loaded bounds.",
4620 rtx, (rtx slot, rtx arg, rtx slot_no),
4621 default_load_bounds_for_arg)
4624 (store_bounds_for_arg,
4625 "This hook is used by expand pass to emit insns to store @var{bounds} of\n\
4626 @var{arg} passed in @var{slot}. Expand pass uses this hook in case\n\
4627 @var{bounds} of @var{arg} are not passed in register. If @var{slot} is a\n\
4628 memory, then @var{bounds} are stored as for regular pointer stored in\n\
4629 memory. If @var{slot} is not a memory then @var{slot_no} is an integer\n\
4630 constant holding number of the target dependent special slot which\n\
4631 should be used to store @var{bounds}.",
4632 void, (rtx arg, rtx slot, rtx bounds, rtx slot_no),
4633 default_store_bounds_for_arg)
4636 (load_returned_bounds,
4637 "This hook is used by expand pass to emit insn to load bounds\n\
4638 returned by function call in @var{slot}. Hook returns RTX holding\n\
4641 default_load_returned_bounds)
4644 (store_returned_bounds,
4645 "This hook is used by expand pass to emit insn to store @var{bounds}\n\
4646 returned by function call into @var{slot}.",
4647 void, (rtx slot, rtx bounds),
4648 default_store_returned_bounds)
4652 "While generating RTL for a function call, this target hook is invoked once\n\
4653 for each argument passed to the function, either a register returned by\n\
4654 @code{TARGET_FUNCTION_ARG} or a memory location. It is called just\n\
4655 before the point where argument registers are stored. The type of the\n\
4656 function to be called is also passed as the second argument; it is\n\
4657 @code{NULL_TREE} for libcalls. The @code{TARGET_END_CALL_ARGS} hook is\n\
4658 invoked just after the code to copy the return reg has been emitted.\n\
4659 This functionality can be used to perform special setup of call argument\n\
4660 registers if a target needs it.\n\
4661 For functions without arguments, the hook is called once with @code{pc_rtx}\n\
4662 passed instead of an argument register.\n\
4663 Most ports do not need to implement anything for this hook.",
4669 "This target hook is invoked while generating RTL for a function call,\n\
4670 just after the point where the return reg is copied into a pseudo. It\n\
4671 signals that all the call argument and return registers for the just\n\
4672 emitted call are now no longer in use.\n\
4673 Most ports do not need to implement anything for this hook.",
4678 (strict_argument_naming,
4679 "Define this hook to return @code{true} if the location where a function\n\
4680 argument is passed depends on whether or not it is a named argument.\n\
4682 This hook controls how the @var{named} argument to @code{TARGET_FUNCTION_ARG}\n\
4683 is set for varargs and stdarg functions. If this hook returns\n\
4684 @code{true}, the @var{named} argument is always true for named\n\
4685 arguments, and false for unnamed arguments. If it returns @code{false},\n\
4686 but @code{TARGET_PRETEND_OUTGOING_VARARGS_NAMED} returns @code{true},\n\
4687 then all arguments are treated as named. Otherwise, all named arguments\n\
4688 except the last are treated as named.\n\
4690 You need not define this hook if it always returns @code{false}.",
4691 bool, (cumulative_args_t ca),
4692 hook_bool_CUMULATIVE_ARGS_false)
4694 /* Returns true if we should use
4695 targetm.calls.setup_incoming_varargs() and/or
4696 targetm.calls.strict_argument_naming(). */
4698 (pretend_outgoing_varargs_named,
4699 "If you need to conditionally change ABIs so that one works with\n\
4700 @code{TARGET_SETUP_INCOMING_VARARGS}, but the other works like neither\n\
4701 @code{TARGET_SETUP_INCOMING_VARARGS} nor @code{TARGET_STRICT_ARGUMENT_NAMING} was\n\
4702 defined, then define this hook to return @code{true} if\n\
4703 @code{TARGET_SETUP_INCOMING_VARARGS} is used, @code{false} otherwise.\n\
4704 Otherwise, you should not define this hook.",
4705 bool, (cumulative_args_t ca),
4706 default_pretend_outgoing_varargs_named)
4708 /* Given a complex type T, return true if a parameter of type T
4709 should be passed as two scalars. */
4712 "This hook should return true if parameter of type @var{type} are passed\n\
4713 as two scalar parameters. By default, GCC will attempt to pack complex\n\
4714 arguments into the target's word size. Some ABIs require complex arguments\n\
4715 to be split and treated as their individual components. For example, on\n\
4716 AIX64, complex floats should be passed in a pair of floating point\n\
4717 registers, even though a complex float would fit in one 64-bit floating\n\
4720 The default value of this hook is @code{NULL}, which is treated as always\n\
4722 bool, (const_tree type), NULL)
4724 /* Return true if type T, mode MODE, may not be passed in registers,
4725 but must be passed on the stack. */
4726 /* ??? This predicate should be applied strictly after pass-by-reference.
4727 Need audit to verify that this is the case. */
4729 (must_pass_in_stack,
4730 "This target hook should return @code{true} if we should not pass @var{arg}\n\
4731 solely in registers. The file @file{expr.h} defines a\n\
4732 definition that is usually appropriate, refer to @file{expr.h} for additional\n\
4734 bool, (const function_arg_info &arg),
4735 must_pass_in_stack_var_size_or_pad)
4737 /* Return true if type TYPE, mode MODE, which is passed by reference,
4738 should have the object copy generated by the callee rather than
4739 the caller. It is never called for TYPE requiring constructors. */
4742 "The function argument described by the parameters to this hook is\n\
4743 known to be passed by reference. The hook should return true if the\n\
4744 function argument should be copied by the callee instead of copied\n\
4747 For any argument for which the hook returns true, if it can be\n\
4748 determined that the argument is not modified, then a copy need\n\
4749 not be generated.\n\
4751 The default version of this hook always returns false.",
4753 (cumulative_args_t cum, const function_arg_info &arg),
4754 hook_bool_CUMULATIVE_ARGS_arg_info_false)
4756 /* Return zero for arguments passed entirely on the stack or entirely
4757 in registers. If passed in both, return the number of bytes passed
4758 in registers; the balance is therefore passed on the stack. */
4761 "This target hook returns the number of bytes at the beginning of an\n\
4762 argument that must be put in registers. The value must be zero for\n\
4763 arguments that are passed entirely in registers or that are entirely\n\
4764 pushed on the stack.\n\
4766 On some machines, certain arguments must be passed partially in\n\
4767 registers and partially in memory. On these machines, typically the\n\
4768 first few words of arguments are passed in registers, and the rest\n\
4769 on the stack. If a multi-word argument (a @code{double} or a\n\
4770 structure) crosses that boundary, its first few words must be passed\n\
4771 in registers and the rest must be pushed. This macro tells the\n\
4772 compiler when this occurs, and how many bytes should go in registers.\n\
4774 @code{TARGET_FUNCTION_ARG} for these arguments should return the first\n\
4775 register to be used by the caller for this argument; likewise\n\
4776 @code{TARGET_FUNCTION_INCOMING_ARG}, for the called function.",
4777 int, (cumulative_args_t cum, const function_arg_info &arg),
4778 hook_int_CUMULATIVE_ARGS_arg_info_0)
4780 /* Update the state in CA to advance past an argument in the
4781 argument list. The values MODE, TYPE, and NAMED describe that
4784 (function_arg_advance,
4785 "This hook updates the summarizer variable pointed to by @var{ca} to\n\
4786 advance past argument @var{arg} in the argument list. Once this is done,\n\
4787 the variable @var{cum} is suitable for analyzing the @emph{following}\n\
4788 argument with @code{TARGET_FUNCTION_ARG}, etc.\n\
4790 This hook need not do anything if the argument in question was passed\n\
4791 on the stack. The compiler knows how to track the amount of stack space\n\
4792 used for arguments without any special help.",
4794 (cumulative_args_t ca, const function_arg_info &arg),
4795 default_function_arg_advance)
4798 (function_arg_offset,
4799 "This hook returns the number of bytes to add to the offset of an\n\
4800 argument of type @var{type} and mode @var{mode} when passed in memory.\n\
4801 This is needed for the SPU, which passes @code{char} and @code{short}\n\
4802 arguments in the preferred slot that is in the middle of the quad word\n\
4803 instead of starting at the top. The default implementation returns 0.",
4804 HOST_WIDE_INT, (machine_mode mode, const_tree type),
4805 default_function_arg_offset)
4808 (function_arg_padding,
4809 "This hook determines whether, and in which direction, to pad out\n\
4810 an argument of mode @var{mode} and type @var{type}. It returns\n\
4811 @code{PAD_UPWARD} to insert padding above the argument, @code{PAD_DOWNWARD}\n\
4812 to insert padding below the argument, or @code{PAD_NONE} to inhibit padding.\n\
4814 The @emph{amount} of padding is not controlled by this hook, but by\n\
4815 @code{TARGET_FUNCTION_ARG_ROUND_BOUNDARY}. It is always just enough\n\
4816 to reach the next multiple of that boundary.\n\
4818 This hook has a default definition that is right for most systems.\n\
4819 For little-endian machines, the default is to pad upward. For\n\
4820 big-endian machines, the default is to pad downward for an argument of\n\
4821 constant size shorter than an @code{int}, and upward otherwise.",
4822 pad_direction, (machine_mode mode, const_tree type),
4823 default_function_arg_padding)
4825 /* Return zero if the argument described by the state of CA should
4826 be placed on a stack, or a hard register in which to store the
4827 argument. The values MODE, TYPE, and NAMED describe that
4831 "Return an RTX indicating whether function argument @var{arg} is passed\n\
4832 in a register and if so, which register. Argument @var{ca} summarizes all\n\
4833 the previous arguments.\n\
4835 The return value is usually either a @code{reg} RTX for the hard\n\
4836 register in which to pass the argument, or zero to pass the argument\n\
4839 The return value can be a @code{const_int} which means argument is\n\
4840 passed in a target specific slot with specified number. Target hooks\n\
4841 should be used to store or load argument in such case. See\n\
4842 @code{TARGET_STORE_BOUNDS_FOR_ARG} and @code{TARGET_LOAD_BOUNDS_FOR_ARG}\n\
4843 for more information.\n\
4845 The value of the expression can also be a @code{parallel} RTX@. This is\n\
4846 used when an argument is passed in multiple locations. The mode of the\n\
4847 @code{parallel} should be the mode of the entire argument. The\n\
4848 @code{parallel} holds any number of @code{expr_list} pairs; each one\n\
4849 describes where part of the argument is passed. In each\n\
4850 @code{expr_list} the first operand must be a @code{reg} RTX for the hard\n\
4851 register in which to pass this part of the argument, and the mode of the\n\
4852 register RTX indicates how large this part of the argument is. The\n\
4853 second operand of the @code{expr_list} is a @code{const_int} which gives\n\
4854 the offset in bytes into the entire argument of where this part starts.\n\
4855 As a special exception the first @code{expr_list} in the @code{parallel}\n\
4856 RTX may have a first operand of zero. This indicates that the entire\n\
4857 argument is also stored on the stack.\n\
4859 The last time this hook is called, it is called with @code{MODE ==\n\
4860 VOIDmode}, and its result is passed to the @code{call} or @code{call_value}\n\
4861 pattern as operands 2 and 3 respectively.\n\
4863 @cindex @file{stdarg.h} and register arguments\n\
4864 The usual way to make the ISO library @file{stdarg.h} work on a\n\
4865 machine where some arguments are usually passed in registers, is to\n\
4866 cause nameless arguments to be passed on the stack instead. This is\n\
4867 done by making @code{TARGET_FUNCTION_ARG} return 0 whenever\n\
4868 @var{named} is @code{false}.\n\
4870 @cindex @code{TARGET_MUST_PASS_IN_STACK}, and @code{TARGET_FUNCTION_ARG}\n\
4871 @cindex @code{REG_PARM_STACK_SPACE}, and @code{TARGET_FUNCTION_ARG}\n\
4872 You may use the hook @code{targetm.calls.must_pass_in_stack}\n\
4873 in the definition of this macro to determine if this argument is of a\n\
4874 type that must be passed in the stack. If @code{REG_PARM_STACK_SPACE}\n\
4875 is not defined and @code{TARGET_FUNCTION_ARG} returns nonzero for such an\n\
4876 argument, the compiler will abort. If @code{REG_PARM_STACK_SPACE} is\n\
4877 defined, the argument will be computed in the stack and then loaded into\n\
4879 rtx, (cumulative_args_t ca, const function_arg_info &arg),
4880 default_function_arg)
4883 (function_incoming_arg,
4884 "Define this hook if the caller and callee on the target have different\n\
4885 views of where arguments are passed. Also define this hook if there are\n\
4886 functions that are never directly called, but are invoked by the hardware\n\
4887 and which have nonstandard calling conventions.\n\
4889 In this case @code{TARGET_FUNCTION_ARG} computes the register in\n\
4890 which the caller passes the value, and\n\
4891 @code{TARGET_FUNCTION_INCOMING_ARG} should be defined in a similar\n\
4892 fashion to tell the function being called where the arguments will\n\
4895 @code{TARGET_FUNCTION_INCOMING_ARG} can also return arbitrary address\n\
4896 computation using hard register, which can be forced into a register,\n\
4897 so that it can be used to pass special arguments.\n\
4899 If @code{TARGET_FUNCTION_INCOMING_ARG} is not defined,\n\
4900 @code{TARGET_FUNCTION_ARG} serves both purposes.",
4901 rtx, (cumulative_args_t ca, const function_arg_info &arg),
4902 default_function_incoming_arg)
4905 (function_arg_boundary,
4906 "This hook returns the alignment boundary, in bits, of an argument\n\
4907 with the specified mode and type. The default hook returns\n\
4908 @code{PARM_BOUNDARY} for all arguments.",
4909 unsigned int, (machine_mode mode, const_tree type),
4910 default_function_arg_boundary)
4913 (function_arg_round_boundary,
4914 "Normally, the size of an argument is rounded up to @code{PARM_BOUNDARY},\n\
4915 which is the default value for this hook. You can define this hook to\n\
4916 return a different value if an argument size must be rounded to a larger\n\
4918 unsigned int, (machine_mode mode, const_tree type),
4919 default_function_arg_round_boundary)
4921 /* Return the diagnostic message string if function without a prototype
4922 is not allowed for this 'val' argument; NULL otherwise. */
4924 (invalid_arg_for_unprototyped_fn,
4925 "If defined, this macro returns the diagnostic message when it is\n\
4926 illegal to pass argument @var{val} to function @var{funcdecl}\n\
4927 with prototype @var{typelist}.",
4928 const char *, (const_tree typelist, const_tree funcdecl, const_tree val),
4929 hook_invalid_arg_for_unprototyped_fn)
4931 /* Return an rtx for the return value location of the function
4932 specified by FN_DECL_OR_TYPE with a return type of RET_TYPE. */
4936 Define this to return an RTX representing the place where a function\n\
4937 returns or receives a value of data type @var{ret_type}, a tree node\n\
4938 representing a data type. @var{fn_decl_or_type} is a tree node\n\
4939 representing @code{FUNCTION_DECL} or @code{FUNCTION_TYPE} of a\n\
4940 function being called. If @var{outgoing} is false, the hook should\n\
4941 compute the register in which the caller will see the return value.\n\
4942 Otherwise, the hook should return an RTX representing the place where\n\
4943 a function returns a value.\n\
4945 On many machines, only @code{TYPE_MODE (@var{ret_type})} is relevant.\n\
4946 (Actually, on most machines, scalar values are returned in the same\n\
4947 place regardless of mode.) The value of the expression is usually a\n\
4948 @code{reg} RTX for the hard register where the return value is stored.\n\
4949 The value can also be a @code{parallel} RTX, if the return value is in\n\
4950 multiple places. See @code{TARGET_FUNCTION_ARG} for an explanation of the\n\
4951 @code{parallel} form. Note that the callee will populate every\n\
4952 location specified in the @code{parallel}, but if the first element of\n\
4953 the @code{parallel} contains the whole return value, callers will use\n\
4954 that element as the canonical location and ignore the others. The m68k\n\
4955 port uses this type of @code{parallel} to return pointers in both\n\
4956 @samp{%a0} (the canonical location) and @samp{%d0}.\n\
4958 If @code{TARGET_PROMOTE_FUNCTION_RETURN} returns true, you must apply\n\
4959 the same promotion rules specified in @code{PROMOTE_MODE} if\n\
4960 @var{valtype} is a scalar type.\n\
4962 If the precise function being called is known, @var{func} is a tree\n\
4963 node (@code{FUNCTION_DECL}) for it; otherwise, @var{func} is a null\n\
4964 pointer. This makes it possible to use a different value-returning\n\
4965 convention for specific functions when all their calls are\n\
4968 Some target machines have ``register windows'' so that the register in\n\
4969 which a function returns its value is not the same as the one in which\n\
4970 the caller sees the value. For such machines, you should return\n\
4971 different RTX depending on @var{outgoing}.\n\
4973 @code{TARGET_FUNCTION_VALUE} is not used for return values with\n\
4974 aggregate data types, because these are returned in another way. See\n\
4975 @code{TARGET_STRUCT_VALUE_RTX} and related macros, below.",
4976 rtx, (const_tree ret_type, const_tree fn_decl_or_type, bool outgoing),
4977 default_function_value)
4979 /* Return the rtx for the result of a libcall of mode MODE,
4980 calling the function FN_NAME. */
4983 "Define this hook if the back-end needs to know the name of the libcall\n\
4984 function in order to determine where the result should be returned.\n\
4986 The mode of the result is given by @var{mode} and the name of the called\n\
4987 library function is given by @var{fun}. The hook should return an RTX\n\
4988 representing the place where the library function result will be returned.\n\
4990 If this hook is not defined, then LIBCALL_VALUE will be used.",
4991 rtx, (machine_mode mode, const_rtx fun),
4992 default_libcall_value)
4994 /* Return true if REGNO is a possible register number for
4995 a function value as seen by the caller. */
4997 (function_value_regno_p,
4998 "A target hook that return @code{true} if @var{regno} is the number of a hard\n\
4999 register in which the values of called function may come back.\n\
5001 A register whose use for returning values is limited to serving as the\n\
5002 second of a pair (for a value of type @code{double}, say) need not be\n\
5003 recognized by this target hook.\n\
5005 If the machine has register windows, so that the caller and the called\n\
5006 function use different registers for the return value, this target hook\n\
5007 should recognize only the caller's register numbers.\n\
5009 If this hook is not defined, then FUNCTION_VALUE_REGNO_P will be used.",
5010 bool, (const unsigned int regno),
5011 default_function_value_regno_p)
5015 "Return the ABI used by a function with type @var{type}; see the\n\
5016 definition of @code{predefined_function_abi} for details of the ABI\n\
5017 descriptor. Targets only need to define this hook if they support\n\
5018 interoperability between several ABIs in the same translation unit.",
5019 const predefined_function_abi &, (const_tree type),
5024 "This hook returns a description of the ABI used by the target of\n\
5025 call instruction @var{insn}; see the definition of\n\
5026 @code{predefined_function_abi} for details of the ABI descriptor.\n\
5027 Only the global function @code{insn_callee_abi} should call this hook\n\
5030 Targets only need to define this hook if they support\n\
5031 interoperability between several ABIs in the same translation unit.",
5032 const predefined_function_abi &, (const rtx_insn *insn),
5035 /* ??? Documenting this hook requires a GFDL license grant. */
5037 (internal_arg_pointer,
5038 "Return an rtx for the argument pointer incoming to the\
5041 default_internal_arg_pointer)
5043 /* Update the current function stack boundary if needed. */
5045 (update_stack_boundary,
5046 "Define this macro to update the current function stack boundary if\n\
5050 /* Handle stack alignment and return an rtx for Dynamic Realign
5051 Argument Pointer if necessary. */
5054 "This hook should return an rtx for Dynamic Realign Argument Pointer (DRAP) if a\n\
5055 different argument pointer register is needed to access the function's\n\
5056 argument list due to stack realignment. Return @code{NULL} if no DRAP\n\
5060 /* Return true if all function parameters should be spilled to the
5063 (allocate_stack_slots_for_args,
5064 "When optimization is disabled, this hook indicates whether or not\n\
5065 arguments should be allocated to stack slots. Normally, GCC allocates\n\
5066 stacks slots for arguments when not optimizing in order to make\n\
5067 debugging easier. However, when a function is declared with\n\
5068 @code{__attribute__((naked))}, there is no stack frame, and the compiler\n\
5069 cannot safely move arguments from the registers in which they are passed\n\
5070 to the stack. Therefore, this hook should return true in general, but\n\
5071 false for naked functions. The default implementation always returns true.",
5073 hook_bool_void_true)
5075 /* Return an rtx for the static chain for FNDECL_OR_TYPE. If INCOMING_P
5076 is true, then it should be for the callee; otherwise for the caller. */
5079 "This hook replaces the use of @code{STATIC_CHAIN_REGNUM} et al for\n\
5080 targets that may use different static chain locations for different\n\
5081 nested functions. This may be required if the target has function\n\
5082 attributes that affect the calling conventions of the function and\n\
5083 those calling conventions use different static chain locations.\n\
5085 The default version of this hook uses @code{STATIC_CHAIN_REGNUM} et al.\n\
5087 If the static chain is passed in memory, this hook should be used to\n\
5088 provide rtx giving @code{mem} expressions that denote where they are stored.\n\
5089 Often the @code{mem} expression as seen by the caller will be at an offset\n\
5090 from the stack pointer and the @code{mem} expression as seen by the callee\n\
5091 will be at an offset from the frame pointer.\n\
5092 @findex stack_pointer_rtx\n\
5093 @findex frame_pointer_rtx\n\
5094 @findex arg_pointer_rtx\n\
5095 The variables @code{stack_pointer_rtx}, @code{frame_pointer_rtx}, and\n\
5096 @code{arg_pointer_rtx} will have been initialized and should be used\n\
5097 to refer to those items.",
5098 rtx, (const_tree fndecl_or_type, bool incoming_p),
5099 default_static_chain)
5101 /* Fill in the trampoline at MEM with a call to FNDECL and a
5102 static chain value of CHAIN. */
5105 "This hook is called to initialize a trampoline.\n\
5106 @var{m_tramp} is an RTX for the memory block for the trampoline; @var{fndecl}\n\
5107 is the @code{FUNCTION_DECL} for the nested function; @var{static_chain} is an\n\
5108 RTX for the static chain value that should be passed to the function\n\
5109 when it is called.\n\
5111 If the target defines @code{TARGET_ASM_TRAMPOLINE_TEMPLATE}, then the\n\
5112 first thing this hook should do is emit a block move into @var{m_tramp}\n\
5113 from the memory block returned by @code{assemble_trampoline_template}.\n\
5114 Note that the block move need only cover the constant parts of the\n\
5115 trampoline. If the target isolates the variable parts of the trampoline\n\
5116 to the end, not all @code{TRAMPOLINE_SIZE} bytes need be copied.\n\
5118 If the target requires any other actions, such as flushing caches or\n\
5119 enabling stack execution, these actions should be performed after\n\
5120 initializing the trampoline proper.",
5121 void, (rtx m_tramp, tree fndecl, rtx static_chain),
5122 default_trampoline_init)
5124 /* Adjust the address of the trampoline in a target-specific way. */
5126 (trampoline_adjust_address,
5127 "This hook should perform any machine-specific adjustment in\n\
5128 the address of the trampoline. Its argument contains the address of the\n\
5129 memory block that was passed to @code{TARGET_TRAMPOLINE_INIT}. In case\n\
5130 the address to be used for a function call should be different from the\n\
5131 address at which the template was stored, the different address should\n\
5132 be returned; otherwise @var{addr} should be returned unchanged.\n\
5133 If this hook is not defined, @var{addr} will be used for function calls.",
5134 rtx, (rtx addr), NULL)
5137 (custom_function_descriptors,
5138 "If the target can use GCC's generic descriptor mechanism for nested\n\
5139 functions, define this hook to a power of 2 representing an unused bit\n\
5140 in function pointers which can be used to differentiate descriptors at\n\
5141 run time. This value gives the number of bytes by which descriptor\n\
5142 pointers are misaligned compared to function pointers. For example, on\n\
5143 targets that require functions to be aligned to a 4-byte boundary, a\n\
5144 value of either 1 or 2 is appropriate unless the architecture already\n\
5145 reserves the bit for another purpose, such as on ARM.\n\
5147 Define this hook to 0 if the target implements ABI support for\n\
5148 function descriptors in its standard calling sequence, like for example\n\
5151 Using descriptors for nested functions\n\
5152 eliminates the need for trampolines that reside on the stack and require\n\
5153 it to be made executable.",\
5156 /* Return the number of bytes of its own arguments that a function
5157 pops on returning, or 0 if the function pops no arguments and the
5158 caller must therefore pop them all after the function returns. */
5159 /* ??? tm.texi has no types for the parameters. */
5162 "This target hook returns the number of bytes of its own arguments that\n\
5163 a function pops on returning, or 0 if the function pops no arguments\n\
5164 and the caller must therefore pop them all after the function returns.\n\
5166 @var{fundecl} is a C variable whose value is a tree node that describes\n\
5167 the function in question. Normally it is a node of type\n\
5168 @code{FUNCTION_DECL} that describes the declaration of the function.\n\
5169 From this you can obtain the @code{DECL_ATTRIBUTES} of the function.\n\
5171 @var{funtype} is a C variable whose value is a tree node that\n\
5172 describes the function in question. Normally it is a node of type\n\
5173 @code{FUNCTION_TYPE} that describes the data type of the function.\n\
5174 From this it is possible to obtain the data types of the value and\n\
5175 arguments (if known).\n\
5177 When a call to a library function is being considered, @var{fundecl}\n\
5178 will contain an identifier node for the library function. Thus, if\n\
5179 you need to distinguish among various library functions, you can do so\n\
5180 by their names. Note that ``library function'' in this context means\n\
5181 a function used to perform arithmetic, whose name is known specially\n\
5182 in the compiler and was not mentioned in the C code being compiled.\n\
5184 @var{size} is the number of bytes of arguments passed on the\n\
5185 stack. If a variable number of bytes is passed, it is zero, and\n\
5186 argument popping will always be the responsibility of the calling function.\n\
5188 On the VAX, all functions always pop their arguments, so the definition\n\
5189 of this macro is @var{size}. On the 68000, using the standard\n\
5190 calling convention, no functions pop their arguments, so the value of\n\
5191 the macro is always 0 in this case. But an alternative calling\n\
5192 convention is available in which functions that take a fixed number of\n\
5193 arguments pop them but other functions (such as @code{printf}) pop\n\
5194 nothing (the caller pops all). When this convention is in use,\n\
5195 @var{funtype} is examined to determine whether a function takes a fixed\n\
5196 number of arguments.",
5197 poly_int64, (tree fundecl, tree funtype, poly_int64 size),
5198 default_return_pops_args)
5200 /* Return a mode wide enough to copy any function value that might be
5203 (get_raw_result_mode,
5204 "This target hook returns the mode to be used when accessing raw return\
5205 registers in @code{__builtin_return}. Define this macro if the value\
5206 in @var{reg_raw_mode} is not correct.",
5207 fixed_size_mode, (int regno),
5208 default_get_reg_raw_mode)
5210 /* Return a mode wide enough to copy any argument value that might be
5214 "This target hook returns the mode to be used when accessing raw argument\
5215 registers in @code{__builtin_apply_args}. Define this macro if the value\
5216 in @var{reg_raw_mode} is not correct.",
5217 fixed_size_mode, (int regno),
5218 default_get_reg_raw_mode)
5220 /* Return true if a type is an empty record. */
5223 "This target hook returns true if the type is an empty record. The default\n\
5224 is to return @code{false}.",
5225 bool, (const_tree type),
5226 hook_bool_const_tree_false)
5228 /* Warn about the change in empty class parameter passing ABI. */
5230 (warn_parameter_passing_abi,
5231 "This target hook warns about the change in empty class parameter passing\n\
5233 void, (cumulative_args_t ca, tree type),
5234 hook_void_CUMULATIVE_ARGS_tree)
5236 HOOK_VECTOR_END (calls)
5239 (use_pseudo_pic_reg,
5240 "This hook should return 1 in case pseudo register should be created\n\
5241 for pic_offset_table_rtx during function expand.",
5243 hook_bool_void_false)
5247 "Perform a target dependent initialization of pic_offset_table_rtx.\n\
5248 This hook is called at the start of register allocation.",
5252 /* Return the diagnostic message string if conversion from FROMTYPE
5253 to TOTYPE is not allowed, NULL otherwise. */
5255 (invalid_conversion,
5256 "If defined, this macro returns the diagnostic message when it is\n\
5257 invalid to convert from @var{fromtype} to @var{totype}, or @code{NULL}\n\
5258 if validity should be determined by the front end.",
5259 const char *, (const_tree fromtype, const_tree totype),
5260 hook_constcharptr_const_tree_const_tree_null)
5262 /* Return the diagnostic message string if the unary operation OP is
5263 not permitted on TYPE, NULL otherwise. */
5266 "If defined, this macro returns the diagnostic message when it is\n\
5267 invalid to apply operation @var{op} (where unary plus is denoted by\n\
5268 @code{CONVERT_EXPR}) to an operand of type @var{type}, or @code{NULL}\n\
5269 if validity should be determined by the front end.",
5270 const char *, (int op, const_tree type),
5271 hook_constcharptr_int_const_tree_null)
5273 /* Return the diagnostic message string if the binary operation OP
5274 is not permitted on TYPE1 and TYPE2, NULL otherwise. */
5277 "If defined, this macro returns the diagnostic message when it is\n\
5278 invalid to apply operation @var{op} to operands of types @var{type1}\n\
5279 and @var{type2}, or @code{NULL} if validity should be determined by\n\
5281 const char *, (int op, const_tree type1, const_tree type2),
5282 hook_constcharptr_int_const_tree_const_tree_null)
5284 /* If values of TYPE are promoted to some other type when used in
5285 expressions (analogous to the integer promotions), return that type,
5286 or NULL_TREE otherwise. */
5289 "If defined, this target hook returns the type to which values of\n\
5290 @var{type} should be promoted when they appear in expressions,\n\
5291 analogous to the integer promotions, or @code{NULL_TREE} to use the\n\
5292 front end's normal promotion rules. This hook is useful when there are\n\
5293 target-specific types with special promotion rules.\n\
5294 This is currently used only by the C and C++ front ends.",
5295 tree, (const_tree type),
5296 hook_tree_const_tree_null)
5298 /* Convert EXPR to TYPE, if target-specific types with special conversion
5299 rules are involved. Return the converted expression, or NULL to apply
5300 the standard conversion rules. */
5303 "If defined, this hook returns the result of converting @var{expr} to\n\
5304 @var{type}. It should return the converted expression,\n\
5305 or @code{NULL_TREE} to apply the front end's normal conversion rules.\n\
5306 This hook is useful when there are target-specific types with special\n\
5307 conversion rules.\n\
5308 This is currently used only by the C and C++ front ends.",
5309 tree, (tree type, tree expr),
5310 hook_tree_tree_tree_null)
5313 (verify_type_context,
5314 "If defined, this hook returns false if there is a target-specific reason\n\
5315 why type @var{type} cannot be used in the source language context described\n\
5316 by @var{context}. When @var{silent_p} is false, the hook also reports an\n\
5317 error against @var{loc} for invalid uses of @var{type}.\n\
5319 Calls to this hook should be made through the global function\n\
5320 @code{verify_type_context}, which makes the @var{silent_p} parameter\n\
5321 default to false and also handles @code{error_mark_node}.\n\
5323 The default implementation always returns true.",
5324 bool, (location_t loc, type_context_kind context, const_tree type,
5329 (can_change_mode_class,
5330 "This hook returns true if it is possible to bitcast values held in\n\
5331 registers of class @var{rclass} from mode @var{from} to mode @var{to}\n\
5332 and if doing so preserves the low-order bits that are common to both modes.\n\
5333 The result is only meaningful if @var{rclass} has registers that can hold\n\
5334 both @code{from} and @code{to}. The default implementation returns true.\n\
5336 As an example of when such bitcasting is invalid, loading 32-bit integer or\n\
5337 floating-point objects into floating-point registers on Alpha extends them\n\
5338 to 64 bits. Therefore loading a 64-bit object and then storing it as a\n\
5339 32-bit object does not store the low-order 32 bits, as would be the case\n\
5340 for a normal register. Therefore, @file{alpha.h} defines\n\
5341 @code{TARGET_CAN_CHANGE_MODE_CLASS} to return:\n\
5344 (GET_MODE_SIZE (from) == GET_MODE_SIZE (to)\n\
5345 || !reg_classes_intersect_p (FLOAT_REGS, rclass))\n\
5346 @end smallexample\n\
5348 Even if storing from a register in mode @var{to} would be valid,\n\
5349 if both @var{from} and @code{raw_reg_mode} for @var{rclass} are wider\n\
5350 than @code{word_mode}, then we must prevent @var{to} narrowing the\n\
5351 mode. This happens when the middle-end assumes that it can load\n\
5352 or store pieces of an @var{N}-word pseudo, and that the pseudo will\n\
5353 eventually be allocated to @var{N} @code{word_mode} hard registers.\n\
5354 Failure to prevent this kind of mode change will result in the\n\
5355 entire @code{raw_reg_mode} being modified instead of the partial\n\
5356 value that the middle-end intended.",
5357 bool, (machine_mode from, machine_mode to, reg_class_t rclass),
5358 hook_bool_mode_mode_reg_class_t_true)
5360 /* Change pseudo allocno class calculated by IRA. */
5362 (ira_change_pseudo_allocno_class,
5363 "A target hook which can change allocno class for given pseudo from\n\
5364 allocno and best class calculated by IRA.\n\
5366 The default version of this target hook always returns given class.",
5367 reg_class_t, (int, reg_class_t, reg_class_t),
5368 default_ira_change_pseudo_allocno_class)
5370 /* Return true if we use LRA instead of reload. */
5373 "A target hook which returns true if we use LRA instead of reload pass.\
5375 The default version of this target hook returns true. New ports\
5376 should use LRA, and existing ports are encouraged to convert.",
5380 /* Return register priority of given hard regno for the current target. */
5383 "A target hook which returns the register priority number to which the\
5384 register @var{hard_regno} belongs to. The bigger the number, the\
5385 more preferable the hard register usage (when all other conditions are\
5386 the same). This hook can be used to prefer some hard register over\
5387 others in LRA. For example, some x86-64 register usage needs\
5388 additional prefix which makes instructions longer. The hook can\
5389 return lower priority number for such registers make them less favorable\
5390 and as result making the generated code smaller.\
5392 The default version of this target hook returns always zero.",
5394 default_register_priority)
5396 /* Return true if we need register usage leveling. */
5398 (register_usage_leveling_p,
5399 "A target hook which returns true if we need register usage leveling.\
5400 That means if a few hard registers are equally good for the\
5401 assignment, we choose the least used hard register. The register\
5402 usage leveling may be profitable for some targets. Don't use the\
5403 usage leveling for targets with conditional execution or targets\
5404 with big register files as it hurts if-conversion and cross-jumping\
5407 The default version of this target hook returns always false.",
5409 default_register_usage_leveling_p)
5411 /* Return true if maximal address displacement can be different. */
5413 (different_addr_displacement_p,
5414 "A target hook which returns true if an address with the same structure\
5415 can have different maximal legitimate displacement. For example, the\
5416 displacement can depend on memory mode or on operand combinations in\
5419 The default version of this target hook returns always false.",
5421 default_different_addr_displacement_p)
5423 /* Determine class for spilling pseudos of given mode into registers
5424 instead of memory. */
5427 "This hook defines a class of registers which could be used for spilling\
5428 pseudos of the given mode and class, or @code{NO_REGS} if only memory\
5429 should be used. Not defining this hook is equivalent to returning\
5430 @code{NO_REGS} for all inputs.",
5431 reg_class_t, (reg_class_t, machine_mode),
5434 /* Determine an additional allocno class. */
5436 (additional_allocno_class_p,
5437 "This hook should return @code{true} if given class of registers should\
5438 be an allocno class in any way. Usually RA uses only one register\
5439 class from all classes containing the same register set. In some\
5440 complicated cases, you need to have two or more such classes as\
5441 allocno ones for RA correct work. Not defining this hook is\
5442 equivalent to returning @code{false} for all inputs.",
5443 bool, (reg_class_t),
5444 hook_bool_reg_class_t_false)
5448 "This hook defines the machine mode to use for the boolean result of\
5449 conditional store patterns. The ICODE argument is the instruction code\
5450 for the cstore being performed. Not definiting this hook is the same\
5451 as accepting the mode encoded into operand 0 of the cstore expander\
5453 scalar_int_mode, (enum insn_code icode),
5454 default_cstore_mode)
5456 /* This target hook allows the backend to compute the register pressure
5459 (compute_pressure_classes,
5460 "A target hook which lets a backend compute the set of pressure classes to\
5461 be used by those optimization passes which take register pressure into\
5462 account, as opposed to letting IRA compute them. It returns the number of\
5463 register classes stored in the array @var{pressure_classes}.",
5464 int, (enum reg_class *pressure_classes), NULL)
5466 /* True if a structure, union or array with MODE containing FIELD should
5467 be accessed using BLKmode. */
5469 (member_type_forces_blk,
5470 "Return true if a structure, union or array containing @var{field} should\n\
5471 be accessed using @code{BLKMODE}.\n\
5473 If @var{field} is the only field in the structure, @var{mode} is its\n\
5474 mode, otherwise @var{mode} is VOIDmode. @var{mode} is provided in the\n\
5475 case where structures of one field would require the structure's mode to\n\
5476 retain the field's mode.\n\
5478 Normally, this is not needed.",
5479 bool, (const_tree field, machine_mode mode),
5480 default_member_type_forces_blk)
5482 /* See tree-ssa-math-opts.c:divmod_candidate_p for conditions
5483 that gate the divod transform. */
5485 (expand_divmod_libfunc,
5486 "Define this hook for enabling divmod transform if the port does not have\n\
5487 hardware divmod insn but defines target-specific divmod libfuncs.",
5488 void, (rtx libfunc, machine_mode mode, rtx op0, rtx op1, rtx *quot, rtx *rem),
5491 /* Return the class for a secondary reload, and fill in extra information. */
5494 "Many machines have some registers that cannot be copied directly to or\n\
5495 from memory or even from other types of registers. An example is the\n\
5496 @samp{MQ} register, which on most machines, can only be copied to or\n\
5497 from general registers, but not memory. Below, we shall be using the\n\
5498 term 'intermediate register' when a move operation cannot be performed\n\
5499 directly, but has to be done by copying the source into the intermediate\n\
5500 register first, and then copying the intermediate register to the\n\
5501 destination. An intermediate register always has the same mode as\n\
5502 source and destination. Since it holds the actual value being copied,\n\
5503 reload might apply optimizations to re-use an intermediate register\n\
5504 and eliding the copy from the source when it can determine that the\n\
5505 intermediate register still holds the required value.\n\
5507 Another kind of secondary reload is required on some machines which\n\
5508 allow copying all registers to and from memory, but require a scratch\n\
5509 register for stores to some memory locations (e.g., those with symbolic\n\
5510 address on the RT, and those with certain symbolic address on the SPARC\n\
5511 when compiling PIC)@. Scratch registers need not have the same mode\n\
5512 as the value being copied, and usually hold a different value than\n\
5513 that being copied. Special patterns in the md file are needed to\n\
5514 describe how the copy is performed with the help of the scratch register;\n\
5515 these patterns also describe the number, register class(es) and mode(s)\n\
5516 of the scratch register(s).\n\
5518 In some cases, both an intermediate and a scratch register are required.\n\
5520 For input reloads, this target hook is called with nonzero @var{in_p},\n\
5521 and @var{x} is an rtx that needs to be copied to a register of class\n\
5522 @var{reload_class} in @var{reload_mode}. For output reloads, this target\n\
5523 hook is called with zero @var{in_p}, and a register of class @var{reload_class}\n\
5524 needs to be copied to rtx @var{x} in @var{reload_mode}.\n\
5526 If copying a register of @var{reload_class} from/to @var{x} requires\n\
5527 an intermediate register, the hook @code{secondary_reload} should\n\
5528 return the register class required for this intermediate register.\n\
5529 If no intermediate register is required, it should return NO_REGS.\n\
5530 If more than one intermediate register is required, describe the one\n\
5531 that is closest in the copy chain to the reload register.\n\
5533 If scratch registers are needed, you also have to describe how to\n\
5534 perform the copy from/to the reload register to/from this\n\
5535 closest intermediate register. Or if no intermediate register is\n\
5536 required, but still a scratch register is needed, describe the\n\
5537 copy from/to the reload register to/from the reload operand @var{x}.\n\
5539 You do this by setting @code{sri->icode} to the instruction code of a pattern\n\
5540 in the md file which performs the move. Operands 0 and 1 are the output\n\
5541 and input of this copy, respectively. Operands from operand 2 onward are\n\
5542 for scratch operands. These scratch operands must have a mode, and a\n\
5543 single-register-class\n\
5544 @c [later: or memory]\n\
5545 output constraint.\n\
5547 When an intermediate register is used, the @code{secondary_reload}\n\
5548 hook will be called again to determine how to copy the intermediate\n\
5549 register to/from the reload operand @var{x}, so your hook must also\n\
5550 have code to handle the register class of the intermediate operand.\n\
5552 @c [For later: maybe we'll allow multi-alternative reload patterns -\n\
5553 @c the port maintainer could name a mov<mode> pattern that has clobbers -\n\
5554 @c and match the constraints of input and output to determine the required\n\
5555 @c alternative. A restriction would be that constraints used to match\n\
5556 @c against reloads registers would have to be written as register class\n\
5557 @c constraints, or we need a new target macro / hook that tells us if an\n\
5558 @c arbitrary constraint can match an unknown register of a given class.\n\
5559 @c Such a macro / hook would also be useful in other places.]\n\
5562 @var{x} might be a pseudo-register or a @code{subreg} of a\n\
5563 pseudo-register, which could either be in a hard register or in memory.\n\
5564 Use @code{true_regnum} to find out; it will return @minus{}1 if the pseudo is\n\
5565 in memory and the hard register number if it is in a register.\n\
5567 Scratch operands in memory (constraint @code{\"=m\"} / @code{\"=&m\"}) are\n\
5568 currently not supported. For the time being, you will have to continue\n\
5569 to use @code{TARGET_SECONDARY_MEMORY_NEEDED} for that purpose.\n\
5571 @code{copy_cost} also uses this target hook to find out how values are\n\
5572 copied. If you want it to include some extra cost for the need to allocate\n\
5573 (a) scratch register(s), set @code{sri->extra_cost} to the additional cost.\n\
5574 Or if two dependent moves are supposed to have a lower cost than the sum\n\
5575 of the individual moves due to expected fortuitous scheduling and/or special\n\
5576 forwarding logic, you can set @code{sri->extra_cost} to a negative amount.",
5578 (bool in_p, rtx x, reg_class_t reload_class, machine_mode reload_mode,
5579 secondary_reload_info *sri),
5580 default_secondary_reload)
5583 (secondary_memory_needed,
5584 "Certain machines have the property that some registers cannot be copied\n\
5585 to some other registers without using memory. Define this hook on\n\
5586 those machines to return true if objects of mode @var{m} in registers\n\
5587 of @var{class1} can only be copied to registers of class @var{class2} by\n\
5588 storing a register of @var{class1} into memory and loading that memory\n\
5589 location into a register of @var{class2}. The default definition returns\n\
5590 false for all inputs.",
5591 bool, (machine_mode mode, reg_class_t class1, reg_class_t class2),
5592 hook_bool_mode_reg_class_t_reg_class_t_false)
5595 (secondary_memory_needed_mode,
5596 "If @code{TARGET_SECONDARY_MEMORY_NEEDED} tells the compiler to use memory\n\
5597 when moving between two particular registers of mode @var{mode},\n\
5598 this hook specifies the mode that the memory should have.\n\
5600 The default depends on @code{TARGET_LRA_P}. Without LRA, the default\n\
5601 is to use a word-sized mode for integral modes that are smaller than a\n\
5602 a word. This is right thing to do on most machines because it ensures\n\
5603 that all bits of the register are copied and prevents accesses to the\n\
5604 registers in a narrower mode, which some machines prohibit for\n\
5605 floating-point registers.\n\
5607 However, this default behavior is not correct on some machines, such as\n\
5608 the DEC Alpha, that store short integers in floating-point registers\n\
5609 differently than in integer registers. On those machines, the default\n\
5610 widening will not work correctly and you must define this hook to\n\
5611 suppress that widening in some cases. See the file @file{alpha.c} for\n\
5614 With LRA, the default is to use @var{mode} unmodified.",
5615 machine_mode, (machine_mode mode),
5616 default_secondary_memory_needed_mode)
5618 /* Given an rtx X being reloaded into a reg required to be in class CLASS,
5619 return the class of reg to actually use. */
5621 (preferred_reload_class,
5622 "A target hook that places additional restrictions on the register class\n\
5623 to use when it is necessary to copy value @var{x} into a register in class\n\
5624 @var{rclass}. The value is a register class; perhaps @var{rclass}, or perhaps\n\
5625 another, smaller class.\n\
5627 The default version of this hook always returns value of @code{rclass} argument.\n\
5629 Sometimes returning a more restrictive class makes better code. For\n\
5630 example, on the 68000, when @var{x} is an integer constant that is in range\n\
5631 for a @samp{moveq} instruction, the value of this macro is always\n\
5632 @code{DATA_REGS} as long as @var{rclass} includes the data registers.\n\
5633 Requiring a data register guarantees that a @samp{moveq} will be used.\n\
5635 One case where @code{TARGET_PREFERRED_RELOAD_CLASS} must not return\n\
5636 @var{rclass} is if @var{x} is a legitimate constant which cannot be\n\
5637 loaded into some register class. By returning @code{NO_REGS} you can\n\
5638 force @var{x} into a memory location. For example, rs6000 can load\n\
5639 immediate values into general-purpose registers, but does not have an\n\
5640 instruction for loading an immediate value into a floating-point\n\
5641 register, so @code{TARGET_PREFERRED_RELOAD_CLASS} returns @code{NO_REGS} when\n\
5642 @var{x} is a floating-point constant. If the constant can't be loaded\n\
5643 into any kind of register, code generation will be better if\n\
5644 @code{TARGET_LEGITIMATE_CONSTANT_P} makes the constant illegitimate instead\n\
5645 of using @code{TARGET_PREFERRED_RELOAD_CLASS}.\n\
5647 If an insn has pseudos in it after register allocation, reload will go\n\
5648 through the alternatives and call repeatedly @code{TARGET_PREFERRED_RELOAD_CLASS}\n\
5649 to find the best one. Returning @code{NO_REGS}, in this case, makes\n\
5650 reload add a @code{!} in front of the constraint: the x86 back-end uses\n\
5651 this feature to discourage usage of 387 registers when math is done in\n\
5652 the SSE registers (and vice versa).",
5654 (rtx x, reg_class_t rclass),
5655 default_preferred_reload_class)
5657 /* Like TARGET_PREFERRED_RELOAD_CLASS, but for output reloads instead of
5660 (preferred_output_reload_class,
5661 "Like @code{TARGET_PREFERRED_RELOAD_CLASS}, but for output reloads instead of\n\
5664 The default version of this hook always returns value of @code{rclass}\n\
5667 You can also use @code{TARGET_PREFERRED_OUTPUT_RELOAD_CLASS} to discourage\n\
5668 reload from using some alternatives, like @code{TARGET_PREFERRED_RELOAD_CLASS}.",
5670 (rtx x, reg_class_t rclass),
5671 default_preferred_output_reload_class)
5674 (select_early_remat_modes,
5675 "On some targets, certain modes cannot be held in registers around a\n\
5676 standard ABI call and are relatively expensive to spill to the stack.\n\
5677 The early rematerialization pass can help in such cases by aggressively\n\
5678 recomputing values after calls, so that they don't need to be spilled.\n\
5680 This hook returns the set of such modes by setting the associated bits\n\
5681 in @var{modes}. The default implementation selects no modes, which has\n\
5682 the effect of disabling the early rematerialization pass.",
5683 void, (sbitmap modes),
5684 default_select_early_remat_modes)
5687 (class_likely_spilled_p,
5688 "A target hook which returns @code{true} if pseudos that have been assigned\n\
5689 to registers of class @var{rclass} would likely be spilled because\n\
5690 registers of @var{rclass} are needed for spill registers.\n\
5692 The default version of this target hook returns @code{true} if @var{rclass}\n\
5693 has exactly one register and @code{false} otherwise. On most machines, this\n\
5694 default should be used. For generally register-starved machines, such as\n\
5695 i386, or machines with right register constraints, such as SH, this hook\n\
5696 can be used to avoid excessive spilling.\n\
5698 This hook is also used by some of the global intra-procedural code\n\
5699 transformations to throtle code motion, to avoid increasing register\n\
5701 bool, (reg_class_t rclass),
5702 default_class_likely_spilled_p)
5704 /* Return the maximum number of consecutive registers
5705 needed to represent mode MODE in a register of class RCLASS. */
5708 "A target hook returns the maximum number of consecutive registers\n\
5709 of class @var{rclass} needed to hold a value of mode @var{mode}.\n\
5711 This is closely related to the macro @code{TARGET_HARD_REGNO_NREGS}.\n\
5712 In fact, the value returned by @code{TARGET_CLASS_MAX_NREGS (@var{rclass},\n\
5713 @var{mode})} target hook should be the maximum value of\n\
5714 @code{TARGET_HARD_REGNO_NREGS (@var{regno}, @var{mode})} for all @var{regno}\n\
5715 values in the class @var{rclass}.\n\
5717 This target hook helps control the handling of multiple-word values\n\
5718 in the reload pass.\n\
5720 The default version of this target hook returns the size of @var{mode}\n\
5722 unsigned char, (reg_class_t rclass, machine_mode mode),
5723 default_class_max_nregs)
5726 (preferred_rename_class,
5727 "A target hook that places additional preference on the register\
5728 class to use when it is necessary to rename a register in class\
5729 @var{rclass} to another class, or perhaps @var{NO_REGS}, if no\
5730 preferred register class is found or hook @code{preferred_rename_class}\
5731 is not implemented.\
5732 Sometimes returning a more restrictive class makes better code. For\
5733 example, on ARM, thumb-2 instructions using @code{LO_REGS} may be\
5734 smaller than instructions using @code{GENERIC_REGS}. By returning\
5735 @code{LO_REGS} from @code{preferred_rename_class}, code size can\
5737 reg_class_t, (reg_class_t rclass),
5738 default_preferred_rename_class)
5740 /* This target hook allows the backend to avoid unsafe substitution
5741 during register allocation. */
5743 (cannot_substitute_mem_equiv_p,
5744 "A target hook which returns @code{true} if @var{subst} can't\n\
5745 substitute safely pseudos with equivalent memory values during\n\
5746 register allocation.\n\
5747 The default version of this target hook returns @code{false}.\n\
5748 On most machines, this default should be used. For generally\n\
5749 machines with non orthogonal register usage for addressing, such\n\
5750 as SH, this hook can be used to avoid excessive spilling.",
5752 hook_bool_rtx_false)
5754 /* This target hook allows the backend to legitimize base plus
5755 displacement addressing. */
5757 (legitimize_address_displacement,
5758 "This hook tries to split address offset @var{orig_offset} into\n\
5759 two parts: one that should be added to the base address to create\n\
5760 a local anchor point, and an additional offset that can be applied\n\
5761 to the anchor to address a value of mode @var{mode}. The idea is that\n\
5762 the local anchor could be shared by other accesses to nearby locations.\n\
5764 The hook returns true if it succeeds, storing the offset of the\n\
5765 anchor from the base in @var{offset1} and the offset of the final address\n\
5766 from the anchor in @var{offset2}. The default implementation returns false.",
5767 bool, (rtx *offset1, rtx *offset2, poly_int64 orig_offset, machine_mode mode),
5768 default_legitimize_address_displacement)
5770 /* This target hook allows the backend to perform additional
5771 processing while initializing for variable expansion. */
5773 (expand_to_rtl_hook,
5774 "This hook is called just before expansion into rtl, allowing the target\n\
5775 to perform additional initializations or analysis before the expansion.\n\
5776 For example, the rs6000 port uses it to allocate a scratch stack slot\n\
5777 for use in copying SDmode values between memory and floating point\n\
5778 registers whenever the function being expanded has any SDmode\n\
5783 /* This target hook allows the backend to perform additional
5784 instantiations on rtx that are not actually in insns yet,
5785 but will be later. */
5788 "This hook allows the backend to perform additional instantiations on rtl\n\
5789 that are not actually in any insns yet, but will be later.",
5795 "This hook returns the number of consecutive hard registers, starting\n\
5796 at register number @var{regno}, required to hold a value of mode\n\
5797 @var{mode}. This hook must never return zero, even if a register\n\
5798 cannot hold the requested mode - indicate that with\n\
5799 @code{TARGET_HARD_REGNO_MODE_OK} and/or\n\
5800 @code{TARGET_CAN_CHANGE_MODE_CLASS} instead.\n\
5802 The default definition returns the number of words in @var{mode}.",
5803 unsigned int, (unsigned int regno, machine_mode mode),
5804 default_hard_regno_nregs)
5807 (hard_regno_mode_ok,
5808 "This hook returns true if it is permissible to store a value\n\
5809 of mode @var{mode} in hard register number @var{regno} (or in several\n\
5810 registers starting with that one). The default definition returns true\n\
5813 You need not include code to check for the numbers of fixed registers,\n\
5814 because the allocation mechanism considers them to be always occupied.\n\
5816 @cindex register pairs\n\
5817 On some machines, double-precision values must be kept in even/odd\n\
5818 register pairs. You can implement that by defining this hook to reject\n\
5819 odd register numbers for such modes.\n\
5821 The minimum requirement for a mode to be OK in a register is that the\n\
5822 @samp{mov@var{mode}} instruction pattern support moves between the\n\
5823 register and other hard register in the same class and that moving a\n\
5824 value into the register and back out not alter it.\n\
5826 Since the same instruction used to move @code{word_mode} will work for\n\
5827 all narrower integer modes, it is not necessary on any machine for\n\
5828 this hook to distinguish between these modes, provided you define\n\
5829 patterns @samp{movhi}, etc., to take advantage of this. This is\n\
5830 useful because of the interaction between @code{TARGET_HARD_REGNO_MODE_OK}\n\
5831 and @code{TARGET_MODES_TIEABLE_P}; it is very desirable for all integer\n\
5832 modes to be tieable.\n\
5834 Many machines have special registers for floating point arithmetic.\n\
5835 Often people assume that floating point machine modes are allowed only\n\
5836 in floating point registers. This is not true. Any registers that\n\
5837 can hold integers can safely @emph{hold} a floating point machine\n\
5838 mode, whether or not floating arithmetic can be done on it in those\n\
5839 registers. Integer move instructions can be used to move the values.\n\
5841 On some machines, though, the converse is true: fixed-point machine\n\
5842 modes may not go in floating registers. This is true if the floating\n\
5843 registers normalize any value stored in them, because storing a\n\
5844 non-floating value there would garble it. In this case,\n\
5845 @code{TARGET_HARD_REGNO_MODE_OK} should reject fixed-point machine modes in\n\
5846 floating registers. But if the floating registers do not automatically\n\
5847 normalize, if you can store any bit pattern in one and retrieve it\n\
5848 unchanged without a trap, then any machine mode may go in a floating\n\
5849 register, so you can define this hook to say so.\n\
5851 The primary significance of special floating registers is rather that\n\
5852 they are the registers acceptable in floating point arithmetic\n\
5853 instructions. However, this is of no concern to\n\
5854 @code{TARGET_HARD_REGNO_MODE_OK}. You handle it by writing the proper\n\
5855 constraints for those instructions.\n\
5857 On some machines, the floating registers are especially slow to access,\n\
5858 so that it is better to store a value in a stack frame than in such a\n\
5859 register if floating point arithmetic is not being done. As long as the\n\
5860 floating registers are not in class @code{GENERAL_REGS}, they will not\n\
5861 be used unless some pattern's constraint asks for one.",
5862 bool, (unsigned int regno, machine_mode mode),
5863 hook_bool_uint_mode_true)
5867 "This hook returns true if a value of mode @var{mode1} is accessible\n\
5868 in mode @var{mode2} without copying.\n\
5870 If @code{TARGET_HARD_REGNO_MODE_OK (@var{r}, @var{mode1})} and\n\
5871 @code{TARGET_HARD_REGNO_MODE_OK (@var{r}, @var{mode2})} are always\n\
5872 the same for any @var{r}, then\n\
5873 @code{TARGET_MODES_TIEABLE_P (@var{mode1}, @var{mode2})}\n\
5874 should be true. If they differ for any @var{r}, you should define\n\
5875 this hook to return false unless some other mechanism ensures the\n\
5876 accessibility of the value in a narrower mode.\n\
5878 You should define this hook to return true in as many cases as\n\
5879 possible since doing so will allow GCC to perform better register\n\
5880 allocation. The default definition returns true unconditionally.",
5881 bool, (machine_mode mode1, machine_mode mode2),
5882 hook_bool_mode_mode_true)
5884 /* Return true if is OK to use a hard register REGNO as scratch register
5887 (hard_regno_scratch_ok,
5888 "This target hook should return @code{true} if it is OK to use a hard register\n\
5889 @var{regno} as scratch reg in peephole2.\n\
5891 One common use of this macro is to prevent using of a register that\n\
5892 is not saved by a prologue in an interrupt handler.\n\
5894 The default version of this hook always returns @code{true}.",
5895 bool, (unsigned int regno),
5896 default_hard_regno_scratch_ok)
5899 (hard_regno_call_part_clobbered,
5900 "ABIs usually specify that calls must preserve the full contents\n\
5901 of a particular register, or that calls can alter any part of a\n\
5902 particular register. This information is captured by the target macro\n\
5903 @code{CALL_REALLY_USED_REGISTERS}. However, some ABIs specify that calls\n\
5904 must preserve certain bits of a particular register but can alter others.\n\
5905 This hook should return true if this applies to at least one of the\n\
5906 registers in @samp{(reg:@var{mode} @var{regno})}, and if as a result the\n\
5907 call would alter part of the @var{mode} value. For example, if a call\n\
5908 preserves the low 32 bits of a 64-bit hard register @var{regno} but can\n\
5909 clobber the upper 32 bits, this hook should return true for a 64-bit mode\n\
5910 but false for a 32-bit mode.\n\
5912 The value of @var{abi_id} comes from the @code{predefined_function_abi}\n\
5913 structure that describes the ABI of the call; see the definition of the\n\
5914 structure for more details. If (as is usual) the target uses the same ABI\n\
5915 for all functions in a translation unit, @var{abi_id} is always 0.\n\
5917 The default implementation returns false, which is correct\n\
5918 for targets that don't have partly call-clobbered registers.",
5919 bool, (unsigned int abi_id, unsigned int regno, machine_mode mode),
5920 hook_bool_uint_uint_mode_false)
5923 (get_multilib_abi_name,
5924 "This hook returns name of multilib ABI name.",
5925 const char *, (void),
5926 hook_constcharptr_void_null)
5928 /* Return the smallest number of different values for which it is best to
5929 use a jump-table instead of a tree of conditional branches. */
5931 (case_values_threshold,
5932 "This function return the smallest number of different values for which it\n\
5933 is best to use a jump-table instead of a tree of conditional branches.\n\
5934 The default is four for machines with a @code{casesi} instruction and\n\
5935 five otherwise. This is best for most machines.",
5936 unsigned int, (void),
5937 default_case_values_threshold)
5940 (starting_frame_offset,
5941 "This hook returns the offset from the frame pointer to the first local\n\
5942 variable slot to be allocated. If @code{FRAME_GROWS_DOWNWARD}, it is the\n\
5943 offset to @emph{end} of the first slot allocated, otherwise it is the\n\
5944 offset to @emph{beginning} of the first slot allocated. The default\n\
5945 implementation returns 0.",
5946 HOST_WIDE_INT, (void),
5949 /* Optional callback to advise the target to compute the frame layout. */
5951 (compute_frame_layout,
5952 "This target hook is called once each time the frame layout needs to be\n\
5953 recalculated. The calculations can be cached by the target and can then\n\
5954 be used by @code{INITIAL_ELIMINATION_OFFSET} instead of re-computing the\n\
5955 layout on every invocation of that hook. This is particularly useful\n\
5956 for targets that have an expensive frame layout function. Implementing\n\
5957 this callback is optional.",
5961 /* Return true if a function must have and use a frame pointer. */
5963 (frame_pointer_required,
5964 "This target hook should return @code{true} if a function must have and use\n\
5965 a frame pointer. This target hook is called in the reload pass. If its return\n\
5966 value is @code{true} the function will have a frame pointer.\n\
5968 This target hook can in principle examine the current function and decide\n\
5969 according to the facts, but on most machines the constant @code{false} or the\n\
5970 constant @code{true} suffices. Use @code{false} when the machine allows code\n\
5971 to be generated with no frame pointer, and doing so saves some time or space.\n\
5972 Use @code{true} when there is no possible advantage to avoiding a frame\n\
5975 In certain cases, the compiler does not know how to produce valid code\n\
5976 without a frame pointer. The compiler recognizes those cases and\n\
5977 automatically gives the function a frame pointer regardless of what\n\
5978 @code{targetm.frame_pointer_required} returns. You don't need to worry about\n\
5981 In a function that does not require a frame pointer, the frame pointer\n\
5982 register can be allocated for ordinary usage, unless you mark it as a\n\
5983 fixed register. See @code{FIXED_REGISTERS} for more information.\n\
5985 Default return value is @code{false}.",
5987 hook_bool_void_false)
5989 /* Returns true if the compiler is allowed to try to replace register number
5990 from-reg with register number to-reg. */
5993 "This target hook should return @code{true} if the compiler is allowed to\n\
5994 try to replace register number @var{from_reg} with register number\n\
5995 @var{to_reg}. This target hook will usually be @code{true}, since most of the\n\
5996 cases preventing register elimination are things that the compiler already\n\
5999 Default return value is @code{true}.",
6000 bool, (const int from_reg, const int to_reg),
6001 hook_bool_const_int_const_int_true)
6003 /* Modify any or all of fixed_regs, call_used_regs, global_regs,
6004 reg_names, and reg_class_contents to account of the vagaries of the
6007 (conditional_register_usage,
6008 "This hook may conditionally modify five variables\n\
6009 @code{fixed_regs}, @code{call_used_regs}, @code{global_regs},\n\
6010 @code{reg_names}, and @code{reg_class_contents}, to take into account\n\
6011 any dependence of these register sets on target flags. The first three\n\
6012 of these are of type @code{char []} (interpreted as boolean vectors).\n\
6013 @code{global_regs} is a @code{const char *[]}, and\n\
6014 @code{reg_class_contents} is a @code{HARD_REG_SET}. Before the macro is\n\
6015 called, @code{fixed_regs}, @code{call_used_regs},\n\
6016 @code{reg_class_contents}, and @code{reg_names} have been initialized\n\
6017 from @code{FIXED_REGISTERS}, @code{CALL_USED_REGISTERS},\n\
6018 @code{REG_CLASS_CONTENTS}, and @code{REGISTER_NAMES}, respectively.\n\
6019 @code{global_regs} has been cleared, and any @option{-ffixed-@var{reg}},\n\
6020 @option{-fcall-used-@var{reg}} and @option{-fcall-saved-@var{reg}}\n\
6021 command options have been applied.\n\
6023 @cindex disabling certain registers\n\
6024 @cindex controlling register usage\n\
6025 If the usage of an entire class of registers depends on the target\n\
6026 flags, you may indicate this to GCC by using this macro to modify\n\
6027 @code{fixed_regs} and @code{call_used_regs} to 1 for each of the\n\
6028 registers in the classes which should not be used by GCC@. Also make\n\
6029 @code{define_register_constraint}s return @code{NO_REGS} for constraints\n\
6030 that shouldn't be used.\n\
6032 (However, if this class is not included in @code{GENERAL_REGS} and all\n\
6033 of the insn patterns whose constraints permit this class are\n\
6034 controlled by target switches, then GCC will automatically avoid using\n\
6035 these registers when the target switches are opposed to them.)",
6040 (stack_clash_protection_alloca_probe_range,
6041 "Some targets have an ABI defined interval for which no probing needs to be done.\n\
6042 When a probe does need to be done this same interval is used as the probe distance \
6043 up when doing stack clash protection for alloca.\n\
6044 On such targets this value can be set to override the default probing up interval.\n\
6045 Define this variable to return nonzero if such a probe range is required or zero otherwise. \
6046 Defining this hook also requires your functions which make use of alloca to have at least 8 byes\
6047 of outgoing arguments. If this is not the case the stack will be corrupted.\n\
6048 You need not define this macro if it would always have the value zero.",
6049 HOST_WIDE_INT, (void),
6050 default_stack_clash_protection_alloca_probe_range)
6053 /* Functions specific to the C family of frontends. */
6055 #define HOOK_PREFIX "TARGET_C_"
6056 HOOK_VECTOR (TARGET_C, c)
6058 /* ??? Documenting this hook requires a GFDL license grant. */
6061 "Return machine mode for non-standard constant literal suffix @var{c},\
6062 or VOIDmode if non-standard suffixes are unsupported.",
6063 machine_mode, (char c),
6064 default_mode_for_suffix)
6068 "Return a value, with the same meaning as the C99 macro\
6069 @code{FLT_EVAL_METHOD} that describes which excess precision should be\
6070 applied. @var{type} is either @code{EXCESS_PRECISION_TYPE_IMPLICIT},\
6071 @code{EXCESS_PRECISION_TYPE_FAST}, or\
6072 @code{EXCESS_PRECISION_TYPE_STANDARD}. For\
6073 @code{EXCESS_PRECISION_TYPE_IMPLICIT}, the target should return which\
6074 precision and range operations will be implictly evaluated in regardless\
6075 of the excess precision explicitly added. For\
6076 @code{EXCESS_PRECISION_TYPE_STANDARD} and\
6077 @code{EXCESS_PRECISION_TYPE_FAST}, the target should return the\
6078 explicit excess precision that should be added depending on the\
6079 value set for @option{-fexcess-precision=@r{[}standard@r{|}fast@r{]}}.\
6080 Note that unpredictable explicit excess precision does not make sense,\
6081 so a target should never return @code{FLT_EVAL_METHOD_UNPREDICTABLE}\
6082 when @var{type} is @code{EXCESS_PRECISION_TYPE_STANDARD} or\
6083 @code{EXCESS_PRECISION_TYPE_FAST}.",
6084 enum flt_eval_method, (enum excess_precision_type type),
6085 default_excess_precision)
6089 /* Functions specific to the C++ frontend. */
6091 #define HOOK_PREFIX "TARGET_CXX_"
6092 HOOK_VECTOR (TARGET_CXX, cxx)
6094 /* Return the integer type used for guard variables. */
6097 "Define this hook to override the integer type used for guard variables.\n\
6098 These are used to implement one-time construction of static objects. The\n\
6099 default is long_long_integer_type_node.",
6101 default_cxx_guard_type)
6103 /* Return true if only the low bit of the guard should be tested. */
6106 "This hook determines how guard variables are used. It should return\n\
6107 @code{false} (the default) if the first byte should be used. A return value of\n\
6108 @code{true} indicates that only the least significant bit should be used.",
6110 hook_bool_void_false)
6112 /* Returns the size of the array cookie for an array of type. */
6115 "This hook returns the size of the cookie to use when allocating an array\n\
6116 whose elements have the indicated @var{type}. Assumes that it is already\n\
6117 known that a cookie is needed. The default is\n\
6118 @code{max(sizeof (size_t), alignof(type))}, as defined in section 2.7 of the\n\
6119 IA64/Generic C++ ABI@.",
6121 default_cxx_get_cookie_size)
6123 /* Returns true if the element size should be stored in the array cookie. */
6126 "This hook should return @code{true} if the element size should be stored in\n\
6127 array cookies. The default is to return @code{false}.",
6129 hook_bool_void_false)
6131 /* Allows backends to perform additional processing when
6132 deciding if a class should be exported or imported. */
6134 (import_export_class,
6135 "If defined by a backend this hook allows the decision made to export\n\
6136 class @var{type} to be overruled. Upon entry @var{import_export}\n\
6137 will contain 1 if the class is going to be exported, @minus{}1 if it is going\n\
6138 to be imported and 0 otherwise. This function should return the\n\
6139 modified value and perform any other actions necessary to support the\n\
6140 backend's targeted operating system.",
6141 int, (tree type, int import_export), NULL)
6143 /* Returns true if constructors and destructors return "this". */
6145 (cdtor_returns_this,
6146 "This hook should return @code{true} if constructors and destructors return\n\
6147 the address of the object created/destroyed. The default is to return\n\
6150 hook_bool_void_false)
6152 /* Returns true if the key method for a class can be an inline
6153 function, so long as it is not declared inline in the class
6154 itself. Returning true is the behavior required by the Itanium C++ ABI. */
6156 (key_method_may_be_inline,
6157 "This hook returns true if the key method for a class (i.e., the method\n\
6158 which, if defined in the current translation unit, causes the virtual\n\
6159 table to be emitted) may be an inline function. Under the standard\n\
6160 Itanium C++ ABI the key method may be an inline function so long as\n\
6161 the function is not declared inline in the class definition. Under\n\
6162 some variants of the ABI, an inline function can never be the key\n\
6163 method. The default is to return @code{true}.",
6165 hook_bool_void_true)
6168 (determine_class_data_visibility,
6169 "@var{decl} is a virtual table, virtual table table, typeinfo object,\
6170 or other similar implicit class data object that will be emitted with\
6171 external linkage in this translation unit. No ELF visibility has been\
6172 explicitly specified. If the target needs to specify a visibility\
6173 other than that of the containing class, use this hook to set\
6174 @code{DECL_VISIBILITY} and @code{DECL_VISIBILITY_SPECIFIED}.",
6178 /* Returns true (the default) if virtual tables and other
6179 similar implicit class data objects are always COMDAT if they
6180 have external linkage. If this hook returns false, then
6181 class data for classes whose virtual table will be emitted in
6182 only one translation unit will not be COMDAT. */
6184 (class_data_always_comdat,
6185 "This hook returns true (the default) if virtual tables and other\n\
6186 similar implicit class data objects are always COMDAT if they have\n\
6187 external linkage. If this hook returns false, then class data for\n\
6188 classes whose virtual table will be emitted in only one translation\n\
6189 unit will not be COMDAT.",
6191 hook_bool_void_true)
6193 /* Returns true (the default) if the RTTI for the basic types,
6194 which is always defined in the C++ runtime, should be COMDAT;
6195 false if it should not be COMDAT. */
6197 (library_rtti_comdat,
6198 "This hook returns true (the default) if the RTTI information for\n\
6199 the basic types which is defined in the C++ runtime should always\n\
6200 be COMDAT, false if it should not be COMDAT.",
6202 hook_bool_void_true)
6204 /* Returns true if __aeabi_atexit should be used to register static
6208 "This hook returns true if @code{__aeabi_atexit} (as defined by the ARM EABI)\n\
6209 should be used to register static destructors when @option{-fuse-cxa-atexit}\n\
6210 is in effect. The default is to return false to use @code{__cxa_atexit}.",
6212 hook_bool_void_false)
6214 /* Returns true if target may use atexit in the same manner as
6215 __cxa_atexit to register static destructors. */
6217 (use_atexit_for_cxa_atexit,
6218 "This hook returns true if the target @code{atexit} function can be used\n\
6219 in the same manner as @code{__cxa_atexit} to register C++ static\n\
6220 destructors. This requires that @code{atexit}-registered functions in\n\
6221 shared libraries are run in the correct order when the libraries are\n\
6222 unloaded. The default is to return false.",
6224 hook_bool_void_false)
6227 (adjust_class_at_definition,
6228 "@var{type} is a C++ class (i.e., RECORD_TYPE or UNION_TYPE) that has just\
6229 been defined. Use this hook to make adjustments to the class (eg, tweak\
6230 visibility or perform any other required target modifications).",
6235 (decl_mangling_context,
6236 "Return target-specific mangling context of @var{decl} or @code{NULL_TREE}.",
6237 tree, (const_tree decl),
6238 hook_tree_const_tree_null)
6240 HOOK_VECTOR_END (cxx)
6242 /* Functions and data for emulated TLS support. */
6244 #define HOOK_PREFIX "TARGET_EMUTLS_"
6245 HOOK_VECTOR (TARGET_EMUTLS, emutls)
6247 /* Name of the address and common functions. */
6250 "Contains the name of the helper function that uses a TLS control\n\
6251 object to locate a TLS instance. The default causes libgcc's\n\
6252 emulated TLS helper function to be used.",
6253 const char *, "__builtin___emutls_get_address")
6257 "Contains the name of the helper function that should be used at\n\
6258 program startup to register TLS objects that are implicitly\n\
6259 initialized to zero. If this is @code{NULL}, all TLS objects will\n\
6260 have explicit initializers. The default causes libgcc's emulated TLS\n\
6261 registration function to be used.",
6262 const char *, "__builtin___emutls_register_common")
6264 /* Prefixes for proxy variable and template. */
6267 "Contains the name of the section in which TLS control variables should\n\
6268 be placed. The default of @code{NULL} allows these to be placed in\n\
6274 "Contains the name of the section in which TLS initializers should be\n\
6275 placed. The default of @code{NULL} allows these to be placed in any\n\
6279 /* Prefixes for proxy variable and template. */
6282 "Contains the prefix to be prepended to TLS control variable names.\n\
6283 The default of @code{NULL} uses a target-specific prefix.",
6288 "Contains the prefix to be prepended to TLS initializer objects. The\n\
6289 default of @code{NULL} uses a target-specific prefix.",
6292 /* Function to generate field definitions of the proxy variable. */
6295 "Specifies a function that generates the FIELD_DECLs for a TLS control\n\
6296 object type. @var{type} is the RECORD_TYPE the fields are for and\n\
6297 @var{name} should be filled with the structure tag, if the default of\n\
6298 @code{__emutls_object} is unsuitable. The default creates a type suitable\n\
6299 for libgcc's emulated TLS function.",
6300 tree, (tree type, tree *name),
6301 default_emutls_var_fields)
6303 /* Function to initialize a proxy variable. */
6306 "Specifies a function that generates the CONSTRUCTOR to initialize a\n\
6307 TLS control object. @var{var} is the TLS control object, @var{decl}\n\
6308 is the TLS object and @var{tmpl_addr} is the address of the\n\
6309 initializer. The default initializes libgcc's emulated TLS control object.",
6310 tree, (tree var, tree decl, tree tmpl_addr),
6311 default_emutls_var_init)
6313 /* Whether we are allowed to alter the usual alignment of the
6317 "Specifies whether the alignment of TLS control variable objects is\n\
6318 fixed and should not be increased as some backends may do to optimize\n\
6319 single objects. The default is false.",
6322 /* Whether we can emit debug information for TLS vars. */
6324 (debug_form_tls_address,
6325 "Specifies whether a DWARF @code{DW_OP_form_tls_address} location descriptor\n\
6326 may be used to describe emulated TLS control objects.",
6329 HOOK_VECTOR_END (emutls)
6332 #define HOOK_PREFIX "TARGET_OPTION_"
6333 HOOK_VECTOR (TARGET_OPTION_HOOKS, target_option_hooks)
6335 /* Function to validate the attribute((target(...))) strings. If
6336 the option is validated, the hook should also fill in
6337 DECL_FUNCTION_SPECIFIC_TARGET in the function decl node. */
6340 "This hook is called to parse @code{attribute(target(\"...\"))}, which\n\
6341 allows setting target-specific options on individual functions.\n\
6342 These function-specific options may differ\n\
6343 from the options specified on the command line. The hook should return\n\
6344 @code{true} if the options are valid.\n\
6346 The hook should set the @code{DECL_FUNCTION_SPECIFIC_TARGET} field in\n\
6347 the function declaration to hold a pointer to a target-specific\n\
6348 @code{struct cl_target_option} structure.",
6349 bool, (tree fndecl, tree name, tree args, int flags),
6350 default_target_option_valid_attribute_p)
6352 /* Function to save any extra target state in the target options structure. */
6355 "This hook is called to save any additional target-specific information\n\
6356 in the @code{struct cl_target_option} structure for function-specific\n\
6357 options from the @code{struct gcc_options} structure.\n\
6358 @xref{Option file format}.",
6359 void, (struct cl_target_option *ptr, struct gcc_options *opts), NULL)
6361 /* Function to restore any extra target state from the target options
6365 "This hook is called to restore any additional target-specific\n\
6366 information in the @code{struct cl_target_option} structure for\n\
6367 function-specific options to the @code{struct gcc_options} structure.",
6368 void, (struct gcc_options *opts, struct cl_target_option *ptr), NULL)
6370 /* Function to update target-specific option information after being
6374 "This hook is called to update target-specific information in the\n\
6375 @code{struct cl_target_option} structure after it is streamed in from\n\
6377 void, (struct cl_target_option *ptr), NULL)
6379 /* Function to print any extra target state from the target options
6383 "This hook is called to print any additional target-specific\n\
6384 information in the @code{struct cl_target_option} structure for\n\
6385 function-specific options.",
6386 void, (FILE *file, int indent, struct cl_target_option *ptr), NULL)
6388 /* Function to parse arguments to be validated for #pragma target, and to
6389 change the state if the options are valid. If the first argument is
6390 NULL, the second argument specifies the default options to use. Return
6391 true if the options are valid, and set the current state. */
6394 "This target hook parses the options for @code{#pragma GCC target}, which\n\
6395 sets the target-specific options for functions that occur later in the\n\
6396 input stream. The options accepted should be the same as those handled by the\n\
6397 @code{TARGET_OPTION_VALID_ATTRIBUTE_P} hook.",
6398 bool, (tree args, tree pop_target),
6399 default_target_option_pragma_parse)
6401 /* Do option overrides for the target. */
6404 "Sometimes certain combinations of command options do not make sense on\n\
6405 a particular target machine. You can override the hook\n\
6406 @code{TARGET_OPTION_OVERRIDE} to take account of this. This hooks is called\n\
6407 once just after all the command options have been parsed.\n\
6409 Don't use this hook to turn on various extra optimizations for\n\
6410 @option{-O}. That is what @code{TARGET_OPTION_OPTIMIZATION} is for.\n\
6412 If you need to do something whenever the optimization level is\n\
6413 changed via the optimize attribute or pragma, see\n\
6414 @code{TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE}",
6418 /* This function returns true if DECL1 and DECL2 are versions of the same
6419 function. DECL1 and DECL2 are function versions if and only if they
6420 have the same function signature and different target specific attributes,
6421 that is, they are compiled for different target machines. */
6424 "This target hook returns @code{true} if @var{DECL1} and @var{DECL2} are\n\
6425 versions of the same function. @var{DECL1} and @var{DECL2} are function\n\
6426 versions if and only if they have the same function signature and\n\
6427 different target specific attributes, that is, they are compiled for\n\
6428 different target machines.",
6429 bool, (tree decl1, tree decl2),
6430 hook_bool_tree_tree_false)
6432 /* Function to determine if one function can inline another function. */
6434 #define HOOK_PREFIX "TARGET_"
6437 "This target hook returns @code{false} if the @var{caller} function\n\
6438 cannot inline @var{callee}, based on target specific information. By\n\
6439 default, inlining is not allowed if the callee function has function\n\
6440 specific target options and the caller does not use the same options.",
6441 bool, (tree caller, tree callee),
6442 default_target_can_inline_p)
6446 "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.",
6447 void, (tree fndecl),
6450 HOOK_VECTOR_END (target_option)
6452 /* For targets that need to mark extra registers as live on entry to
6453 the function, they should define this target hook and set their
6454 bits in the bitmap passed in. */
6456 (extra_live_on_entry,
6457 "Add any hard registers to @var{regs} that are live on entry to the\n\
6458 function. This hook only needs to be defined to provide registers that\n\
6459 cannot be found by examination of FUNCTION_ARG_REGNO_P, the callee saved\n\
6460 registers, STATIC_CHAIN_INCOMING_REGNUM, STATIC_CHAIN_REGNUM,\n\
6461 TARGET_STRUCT_VALUE_RTX, FRAME_POINTER_REGNUM, EH_USES,\n\
6462 FRAME_POINTER_REGNUM, ARG_POINTER_REGNUM, and the PIC_OFFSET_TABLE_REGNUM.",
6463 void, (bitmap regs),
6466 /* Targets should define this target hook to mark that non-callee clobbers are
6467 present in CALL_INSN_FUNCTION_USAGE for all the calls that bind to a local
6470 (call_fusage_contains_non_callee_clobbers,
6471 "Set to true if each call that binds to a local definition explicitly\n\
6472 clobbers or sets all non-fixed registers modified by performing the call.\n\
6473 That is, by the call pattern itself, or by code that might be inserted by the\n\
6474 linker (e.g.@: stubs, veneers, branch islands), but not including those\n\
6475 modifiable by the callee. The affected registers may be mentioned explicitly\n\
6476 in the call pattern, or included as clobbers in CALL_INSN_FUNCTION_USAGE.\n\
6477 The default version of this hook is set to false. The purpose of this hook\n\
6478 is to enable the fipa-ra optimization.",
6482 /* Fill in additional registers set up by prologue into a regset. */
6484 (set_up_by_prologue,
6485 "This hook should add additional registers that are computed by the prologue\
6486 to the hard regset for shrink-wrapping optimization purposes.",
6487 void, (struct hard_reg_set_container *),
6490 /* For targets that have attributes that can affect whether a
6491 function's return statements need checking. For instance a 'naked'
6492 function attribute. */
6495 "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.",
6497 hook_bool_tree_true)
6500 #define HOOK_PREFIX "TARGET_SHRINK_WRAP_"
6501 HOOK_VECTOR (TARGET_SHRINK_WRAP_HOOKS, shrink_wrap)
6504 (get_separate_components,
6505 "This hook should return an @code{sbitmap} with the bits set for those\n\
6506 components that can be separately shrink-wrapped in the current function.\n\
6507 Return @code{NULL} if the current function should not get any separate\n\
6509 Don't define this hook if it would always return @code{NULL}.\n\
6510 If it is defined, the other hooks in this group have to be defined as well.",
6516 "This hook should return an @code{sbitmap} with the bits set for those\n\
6517 components where either the prologue component has to be executed before\n\
6518 the @code{basic_block}, or the epilogue component after it, or both.",
6519 sbitmap, (basic_block),
6523 (disqualify_components,
6524 "This hook should clear the bits in the @var{components} bitmap for those\n\
6525 components in @var{edge_components} that the target cannot handle on edge\n\
6526 @var{e}, where @var{is_prologue} says if this is for a prologue or an\n\
6528 void, (sbitmap components, edge e, sbitmap edge_components, bool is_prologue),
6532 (emit_prologue_components,
6533 "Emit prologue insns for the components indicated by the parameter.",
6538 (emit_epilogue_components,
6539 "Emit epilogue insns for the components indicated by the parameter.",
6544 (set_handled_components,
6545 "Mark the components in the parameter as handled, so that the\n\
6546 @code{prologue} and @code{epilogue} named patterns know to ignore those\n\
6547 components. The target code should not hang on to the @code{sbitmap}, it\n\
6548 will be deleted after this call.",
6552 HOOK_VECTOR_END (shrink_wrap)
6554 #define HOOK_PREFIX "TARGET_"
6556 /* Determine the type of unwind info to emit for debugging. */
6559 "This hook defines the mechanism that will be used for describing frame\n\
6560 unwind information to the debugger. Normally the hook will return\n\
6561 @code{UI_DWARF2} if DWARF 2 debug information is enabled, and\n\
6562 return @code{UI_NONE} otherwise.\n\
6564 A target may return @code{UI_DWARF2} even when DWARF 2 debug information\n\
6565 is disabled in order to always output DWARF 2 frame information.\n\
6567 A target may return @code{UI_TARGET} if it has ABI specified unwind tables.\n\
6568 This will suppress generation of the normal debug frame unwind information.",
6569 enum unwind_info_type, (void),
6570 default_debug_unwind_info)
6573 (reset_location_view, "\
6574 This hook, if defined, enables -ginternal-reset-location-views, and\n\
6575 uses its result to override cases in which the estimated min insn\n\
6576 length might be nonzero even when a PC advance (i.e., a view reset)\n\
6577 cannot be taken for granted.\n\
6579 If the hook is defined, it must return a positive value to indicate\n\
6580 the insn definitely advances the PC, and so the view number can be\n\
6581 safely assumed to be reset; a negative value to mean the insn\n\
6582 definitely does not advance the PC, and os the view number must not\n\
6583 be reset; or zero to decide based on the estimated insn length.\n\
6585 If insn length is to be regarded as reliable, set the hook to\n\
6586 @code{hook_int_rtx_insn_0}.",
6587 int, (rtx_insn *), NULL)
6589 /* The code parameter should be of type enum rtx_code but this is not
6590 defined at this time. */
6592 (canonicalize_comparison,
6593 "On some machines not all possible comparisons are defined, but you can\n\
6594 convert an invalid comparison into a valid one. For example, the Alpha\n\
6595 does not have a @code{GT} comparison, but you can use an @code{LT}\n\
6596 comparison instead and swap the order of the operands.\n\
6598 On such machines, implement this hook to do any required conversions.\n\
6599 @var{code} is the initial comparison code and @var{op0} and @var{op1}\n\
6600 are the left and right operands of the comparison, respectively. If\n\
6601 @var{op0_preserve_value} is @code{true} the implementation is not\n\
6602 allowed to change the value of @var{op0} since the value might be used\n\
6603 in RTXs which aren't comparisons. E.g. the implementation is not\n\
6604 allowed to swap operands in that case.\n\
6606 GCC will not assume that the comparison resulting from this macro is\n\
6607 valid but will see if the resulting insn matches a pattern in the\n\
6610 You need not to implement this hook if it would never change the\n\
6611 comparison code or operands.",
6612 void, (int *code, rtx *op0, rtx *op1, bool op0_preserve_value),
6613 default_canonicalize_comparison)
6616 (min_arithmetic_precision,
6617 "On some RISC architectures with 64-bit registers, the processor also\n\
6618 maintains 32-bit condition codes that make it possible to do real 32-bit\n\
6619 arithmetic, although the operations are performed on the full registers.\n\
6621 On such architectures, defining this hook to 32 tells the compiler to try\n\
6622 using 32-bit arithmetical operations setting the condition codes instead\n\
6623 of doing full 64-bit arithmetic.\n\
6625 More generally, define this hook on RISC architectures if you want the\n\
6626 compiler to try using arithmetical operations setting the condition codes\n\
6627 with a precision lower than the word precision.\n\
6629 You need not define this hook if @code{WORD_REGISTER_OPERATIONS} is not\n\
6631 unsigned int, (void), default_min_arithmetic_precision)
6634 (atomic_test_and_set_trueval,
6635 "This value should be set if the result written by\
6636 @code{atomic_test_and_set} is not exactly 1, i.e.@: the\
6637 @code{bool} @code{true}.",
6640 /* Return an unsigned int representing the alignment (in bits) of the atomic
6641 type which maps to machine MODE. This allows alignment to be overridden
6644 (atomic_align_for_mode,
6645 "If defined, this function returns an appropriate alignment in bits for an\
6646 atomic object of machine_mode @var{mode}. If 0 is returned then the\
6647 default alignment for the specified mode is used. ",
6648 unsigned int, (machine_mode mode),
6652 (atomic_assign_expand_fenv,
6653 "ISO C11 requires atomic compound assignments that may raise floating-point\
6654 exceptions to raise exceptions corresponding to the arithmetic operation\
6655 whose result was successfully stored in a compare-and-exchange sequence. \
6656 This requires code equivalent to calls to @code{feholdexcept},\
6657 @code{feclearexcept} and @code{feupdateenv} to be generated at\
6658 appropriate points in the compare-and-exchange sequence. This hook should\
6659 set @code{*@var{hold}} to an expression equivalent to the call to\
6660 @code{feholdexcept}, @code{*@var{clear}} to an expression equivalent to\
6661 the call to @code{feclearexcept} and @code{*@var{update}} to an expression\
6662 equivalent to the call to @code{feupdateenv}. The three expressions are\
6663 @code{NULL_TREE} on entry to the hook and may be left as @code{NULL_TREE}\
6664 if no code is required in a particular place. The default implementation\
6665 leaves all three expressions as @code{NULL_TREE}. The\
6666 @code{__atomic_feraiseexcept} function from @code{libatomic} may be of use\
6667 as part of the code generated in @code{*@var{update}}.",
6668 void, (tree *hold, tree *clear, tree *update),
6669 default_atomic_assign_expand_fenv)
6671 /* Leave the boolean fields at the end. */
6673 /* True if we can create zeroed data by switching to a BSS section
6674 and then using ASM_OUTPUT_SKIP to allocate the space. */
6676 (have_switchable_bss_sections,
6677 "This flag is true if we can create zeroed data by switching to a BSS\n\
6678 section and then using @code{ASM_OUTPUT_SKIP} to allocate the space.\n\
6679 This is true on most ELF targets.",
6682 /* True if "native" constructors and destructors are supported,
6683 false if we're using collect2 for the job. */
6686 "This value is true if the target supports some ``native'' method of\n\
6687 collecting constructors and destructors to be run at startup and exit.\n\
6688 It is false if we must use @command{collect2}.",
6691 /* True if thread-local storage is supported. */
6694 "Contains the value true if the target supports thread-local storage.\n\
6695 The default value is false.",
6698 /* True if a small readonly data section is supported. */
6700 (have_srodata_section,
6701 "Contains the value true if the target places read-only\n\
6702 ``small data'' into a separate section. The default value is false.",
6705 /* True if EH frame info sections should be zero-terminated. */
6707 (terminate_dw2_eh_frame_info,
6708 "Contains the value true if the target should add a zero word onto the\n\
6709 end of a Dwarf-2 frame info section when used for exception handling.\n\
6710 Default value is false if @code{EH_FRAME_SECTION_NAME} is defined, and\n\
6714 /* True if #NO_APP should be emitted at the beginning of assembly output. */
6716 (asm_file_start_app_off,
6717 "If this flag is true, the text of the macro @code{ASM_APP_OFF} will be\n\
6718 printed as the very first line in the assembly file, unless\n\
6719 @option{-fverbose-asm} is in effect. (If that macro has been defined\n\
6720 to the empty string, this variable has no effect.) With the normal\n\
6721 definition of @code{ASM_APP_OFF}, the effect is to notify the GNU\n\
6722 assembler that it need not bother stripping comments or extra\n\
6723 whitespace from its input. This allows it to work a bit faster.\n\
6725 The default is false. You should not set it to true unless you have\n\
6726 verified that your port does not generate any extra whitespace or\n\
6727 comments that will cause GAS to issue errors in NO_APP mode.",
6730 /* True if output_file_directive should be called for main_input_filename
6731 at the beginning of assembly output. */
6733 (asm_file_start_file_directive,
6734 "If this flag is true, @code{output_file_directive} will be called\n\
6735 for the primary source file, immediately after printing\n\
6736 @code{ASM_APP_OFF} (if that is enabled). Most ELF assemblers expect\n\
6737 this to be done. The default is false.",
6740 /* Returns true if we should generate exception tables for use with the
6741 ARM EABI. The effects the encoding of function exception specifications. */
6744 "This flag should be set to @code{true} on targets that use an ARM EABI\n\
6745 based unwinding library, and @code{false} on other targets. This effects\n\
6746 the format of unwinding tables, and how the unwinder in entered after\n\
6747 running a cleanup. The default is @code{false}.",
6751 (want_debug_pub_sections,
6752 "True if the @code{.debug_pubtypes} and @code{.debug_pubnames} sections\
6753 should be emitted. These sections are not used on most platforms, and\
6754 in particular GDB does not use them.",
6758 (delay_sched2, "True if sched2 is not to be run at its normal place.\n\
6759 This usually means it will be run as part of machine-specific reorg.",
6763 (delay_vartrack, "True if vartrack is not to be run at its normal place.\n\
6764 This usually means it will be run as part of machine-specific reorg.",
6768 (no_register_allocation, "True if register allocation and the passes\n\
6769 following it should not be run. Usually true only for virtual assembler\n\
6773 /* Leave the boolean fields at the end. */
6775 /* Functions related to mode switching. */
6777 #define HOOK_PREFIX "TARGET_MODE_"
6778 HOOK_VECTOR (TARGET_TOGGLE_, mode_switching)
6782 "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.",
6783 void, (int entity, int mode, int prev_mode, HARD_REG_SET regs_live), NULL)
6787 "@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}.",
6788 int, (int entity, rtx_insn *insn), NULL)
6792 "@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).",
6793 int, (int entity, int mode, rtx_insn *insn), NULL)
6797 "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.",
6798 int, (int entity), NULL)
6802 "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.",
6803 int, (int entity), NULL)
6807 "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}.",
6808 int, (int entity, int n), NULL)
6810 HOOK_VECTOR_END (mode_switching)
6813 #define HOOK_PREFIX "TARGET_"
6815 #define DEF_TARGET_INSN(NAME, PROTO) \
6816 DEFHOOK_UNDOC (have_##NAME, "", bool, (void), false)
6817 #include "target-insns.def"
6818 #undef DEF_TARGET_INSN
6820 #define DEF_TARGET_INSN(NAME, PROTO) \
6821 DEFHOOK_UNDOC (gen_##NAME, "", rtx_insn *, PROTO, NULL)
6822 #include "target-insns.def"
6823 #undef DEF_TARGET_INSN
6825 #define DEF_TARGET_INSN(NAME, PROTO) \
6826 DEFHOOKPOD (code_for_##NAME, "*", enum insn_code, CODE_FOR_nothing)
6827 #include "target-insns.def"
6828 #undef DEF_TARGET_INSN
6831 (run_target_selftests,
6832 "If selftests are enabled, run any selftests for this target.",
6836 /* Close the 'struct gcc_target' definition. */
6837 HOOK_VECTOR_END (C90_EMPTY_HACK)