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[official-gcc.git] / gcc / target.def
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1 /* Target hook definitions.
2 Copyright (C) 2001-2017 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
7 later version.
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"
26 #undef HOOK_TYPE
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. */
36 DEFHOOKPOD
37 (open_paren,
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.",
41 const char *, "(")
42 DEFHOOKPODX (close_paren, const char *, ")")
44 /* Assembler instructions for creating various kinds of integer object. */
45 DEFHOOKPOD
46 (byte_op,
47 "@deftypevrx {Target Hook} {const char *} TARGET_ASM_ALIGNED_HI_OP\n\
48 @deftypevrx {Target Hook} {const char *} TARGET_ASM_ALIGNED_SI_OP\n\
49 @deftypevrx {Target Hook} {const char *} TARGET_ASM_ALIGNED_DI_OP\n\
50 @deftypevrx {Target Hook} {const char *} TARGET_ASM_ALIGNED_TI_OP\n\
51 @deftypevrx {Target Hook} {const char *} TARGET_ASM_UNALIGNED_HI_OP\n\
52 @deftypevrx {Target Hook} {const char *} TARGET_ASM_UNALIGNED_SI_OP\n\
53 @deftypevrx {Target Hook} {const char *} TARGET_ASM_UNALIGNED_DI_OP\n\
54 @deftypevrx {Target Hook} {const char *} TARGET_ASM_UNALIGNED_TI_OP\n\
55 These hooks specify assembly directives for creating certain kinds\n\
56 of integer object. The @code{TARGET_ASM_BYTE_OP} directive creates a\n\
57 byte-sized object, the @code{TARGET_ASM_ALIGNED_HI_OP} one creates an\n\
58 aligned two-byte object, and so on. Any of the hooks may be\n\
59 @code{NULL}, indicating that no suitable directive is available.\n\
60 \n\
61 The compiler will print these strings at the start of a new line,\n\
62 followed immediately by the object's initial value. In most cases,\n\
63 the string should contain a tab, a pseudo-op, and then another tab.",
64 const char *, "\t.byte\t")
65 DEFHOOKPOD (aligned_op, "*", struct asm_int_op, TARGET_ASM_ALIGNED_INT_OP)
66 DEFHOOKPOD (unaligned_op, "*", struct asm_int_op, TARGET_ASM_UNALIGNED_INT_OP)
68 /* The maximum number of bytes to skip when applying
69 LABEL_ALIGN_AFTER_BARRIER. */
70 DEFHOOK
71 (label_align_after_barrier_max_skip,
72 "The maximum number of bytes to skip before @var{label} when applying\n\
73 @code{LABEL_ALIGN_AFTER_BARRIER}. This works only if\n\
74 @code{ASM_OUTPUT_MAX_SKIP_ALIGN} is defined.",
75 int, (rtx_insn *label),
76 default_label_align_after_barrier_max_skip)
78 /* The maximum number of bytes to skip when applying
79 LOOP_ALIGN. */
80 DEFHOOK
81 (loop_align_max_skip,
82 "The maximum number of bytes to skip when applying @code{LOOP_ALIGN} to\n\
83 @var{label}. This works only if @code{ASM_OUTPUT_MAX_SKIP_ALIGN} is\n\
84 defined.",
85 int, (rtx_insn *label),
86 default_loop_align_max_skip)
88 /* The maximum number of bytes to skip when applying
89 LABEL_ALIGN. */
90 DEFHOOK
91 (label_align_max_skip,
92 "The maximum number of bytes to skip when applying @code{LABEL_ALIGN}\n\
93 to @var{label}. This works only if @code{ASM_OUTPUT_MAX_SKIP_ALIGN}\n\
94 is defined.",
95 int, (rtx_insn *label),
96 default_label_align_max_skip)
98 /* The maximum number of bytes to skip when applying
99 JUMP_ALIGN. */
100 DEFHOOK
101 (jump_align_max_skip,
102 "The maximum number of bytes to skip before @var{label} when applying\n\
103 @code{JUMP_ALIGN}. This works only if\n\
104 @code{ASM_OUTPUT_MAX_SKIP_ALIGN} is defined.",
105 int, (rtx_insn *label),
106 default_jump_align_max_skip)
108 /* Try to output the assembler code for an integer object whose
109 value is given by X. SIZE is the size of the object in bytes and
110 ALIGNED_P indicates whether it is aligned. Return true if
111 successful. Only handles cases for which BYTE_OP, ALIGNED_OP
112 and UNALIGNED_OP are NULL. */
113 DEFHOOK
114 (integer,
115 "The @code{assemble_integer} function uses this hook to output an\n\
116 integer object. @var{x} is the object's value, @var{size} is its size\n\
117 in bytes and @var{aligned_p} indicates whether it is aligned. The\n\
118 function should return @code{true} if it was able to output the\n\
119 object. If it returns false, @code{assemble_integer} will try to\n\
120 split the object into smaller parts.\n\
122 The default implementation of this hook will use the\n\
123 @code{TARGET_ASM_BYTE_OP} family of strings, returning @code{false}\n\
124 when the relevant string is @code{NULL}.",
125 /* Only handles cases for which BYTE_OP, ALIGNED_OP and UNALIGNED_OP are
126 NULL. */
127 bool, (rtx x, unsigned int size, int aligned_p),
128 default_assemble_integer)
130 /* Notify the backend that we have completed emitting the data for a
131 decl. */
132 DEFHOOK
133 (decl_end,
134 "Define this hook if the target assembler requires a special marker to\n\
135 terminate an initialized variable declaration.",
136 void, (void),
137 hook_void_void)
139 /* Output code that will globalize a label. */
140 DEFHOOK
141 (globalize_label,
142 "This target hook is a function to output to the stdio stream\n\
143 @var{stream} some commands that will make the label @var{name} global;\n\
144 that is, available for reference from other files.\n\
146 The default implementation relies on a proper definition of\n\
147 @code{GLOBAL_ASM_OP}.",
148 void, (FILE *stream, const char *name),
149 default_globalize_label)
151 /* Output code that will globalize a declaration. */
152 DEFHOOK
153 (globalize_decl_name,
154 "This target hook is a function to output to the stdio stream\n\
155 @var{stream} some commands that will make the name associated with @var{decl}\n\
156 global; that is, available for reference from other files.\n\
158 The default implementation uses the TARGET_ASM_GLOBALIZE_LABEL target hook.",
159 void, (FILE *stream, tree decl), default_globalize_decl_name)
161 /* Output code that will declare an external variable. */
162 DEFHOOK
163 (assemble_undefined_decl,
164 "This target hook is a function to output to the stdio stream\n\
165 @var{stream} some commands that will declare the name associated with\n\
166 @var{decl} which is not defined in the current translation unit. Most\n\
167 assemblers do not require anything to be output in this case.",
168 void, (FILE *stream, const char *name, const_tree decl),
169 hook_void_FILEptr_constcharptr_const_tree)
171 /* Output code that will emit a label for unwind info, if this
172 target requires such labels. Second argument is the decl the
173 unwind info is associated with, third is a boolean: true if
174 this is for exception handling, fourth is a boolean: true if
175 this is only a placeholder for an omitted FDE. */
176 DEFHOOK
177 (emit_unwind_label,
178 "This target hook emits a label at the beginning of each FDE@. It\n\
179 should be defined on targets where FDEs need special labels, and it\n\
180 should write the appropriate label, for the FDE associated with the\n\
181 function declaration @var{decl}, to the stdio stream @var{stream}.\n\
182 The third argument, @var{for_eh}, is a boolean: true if this is for an\n\
183 exception table. The fourth argument, @var{empty}, is a boolean:\n\
184 true if this is a placeholder label for an omitted FDE@.\n\
186 The default is that FDEs are not given nonlocal labels.",
187 void, (FILE *stream, tree decl, int for_eh, int empty),
188 default_emit_unwind_label)
190 /* Output code that will emit a label to divide up the exception table. */
191 DEFHOOK
192 (emit_except_table_label,
193 "This target hook emits a label at the beginning of the exception table.\n\
194 It should be defined on targets where it is desirable for the table\n\
195 to be broken up according to function.\n\
197 The default is that no label is emitted.",
198 void, (FILE *stream),
199 default_emit_except_table_label)
201 /* Emit a directive for setting the personality for the function. */
202 DEFHOOK
203 (emit_except_personality,
204 "If the target implements @code{TARGET_ASM_UNWIND_EMIT}, this hook may be\
205 used to emit a directive to install a personality hook into the unwind\
206 info. This hook should not be used if dwarf2 unwind info is used.",
207 void, (rtx personality),
208 NULL)
210 /* Emit any directives required to unwind this instruction. */
211 DEFHOOK
212 (unwind_emit,
213 "This target hook emits assembly directives required to unwind the\n\
214 given instruction. This is only used when @code{TARGET_EXCEPT_UNWIND_INFO}\n\
215 returns @code{UI_TARGET}.",
216 void, (FILE *stream, rtx_insn *insn),
217 NULL)
219 DEFHOOKPOD
220 (unwind_emit_before_insn,
221 "True if the @code{TARGET_ASM_UNWIND_EMIT} hook should be called before\
222 the assembly for @var{insn} has been emitted, false if the hook should\
223 be called afterward.",
224 bool, true)
226 /* Generate an internal label.
227 For now this is just a wrapper for ASM_GENERATE_INTERNAL_LABEL. */
228 DEFHOOK_UNDOC
229 (generate_internal_label,
231 void, (char *buf, const char *prefix, unsigned long labelno),
232 default_generate_internal_label)
234 /* Output an internal label. */
235 DEFHOOK
236 (internal_label,
237 "A function to output to the stdio stream @var{stream} a label whose\n\
238 name is made from the string @var{prefix} and the number @var{labelno}.\n\
240 It is absolutely essential that these labels be distinct from the labels\n\
241 used for user-level functions and variables. Otherwise, certain programs\n\
242 will have name conflicts with internal labels.\n\
244 It is desirable to exclude internal labels from the symbol table of the\n\
245 object file. Most assemblers have a naming convention for labels that\n\
246 should be excluded; on many systems, the letter @samp{L} at the\n\
247 beginning of a label has this effect. You should find out what\n\
248 convention your system uses, and follow it.\n\
250 The default version of this function utilizes @code{ASM_GENERATE_INTERNAL_LABEL}.",
251 void, (FILE *stream, const char *prefix, unsigned long labelno),
252 default_internal_label)
254 /* Output label for the constant. */
255 DEFHOOK
256 (declare_constant_name,
257 "A target hook to output to the stdio stream @var{file} any text necessary\n\
258 for declaring the name @var{name} of a constant which is being defined. This\n\
259 target hook is responsible for outputting the label definition (perhaps using\n\
260 @code{assemble_label}). The argument @var{exp} is the value of the constant,\n\
261 and @var{size} is the size of the constant in bytes. The @var{name}\n\
262 will be an internal label.\n\
264 The default version of this target hook, define the @var{name} in the\n\
265 usual manner as a label (by means of @code{assemble_label}).\n\
267 You may wish to use @code{ASM_OUTPUT_TYPE_DIRECTIVE} in this target hook.",
268 void, (FILE *file, const char *name, const_tree expr, HOST_WIDE_INT size),
269 default_asm_declare_constant_name)
271 /* Emit a ttype table reference to a typeinfo object. */
272 DEFHOOK
273 (ttype,
274 "This hook is used to output a reference from a frame unwinding table to\n\
275 the type_info object identified by @var{sym}. It should return @code{true}\n\
276 if the reference was output. Returning @code{false} will cause the\n\
277 reference to be output using the normal Dwarf2 routines.",
278 bool, (rtx sym),
279 hook_bool_rtx_false)
281 /* Emit an assembler directive to set visibility for the symbol
282 associated with the tree decl. */
283 DEFHOOK
284 (assemble_visibility,
285 "This target hook is a function to output to @var{asm_out_file} some\n\
286 commands that will make the symbol(s) associated with @var{decl} have\n\
287 hidden, protected or internal visibility as specified by @var{visibility}.",
288 void, (tree decl, int visibility),
289 default_assemble_visibility)
291 /* Output the assembler code for entry to a function. */
292 DEFHOOK
293 (function_prologue,
294 "If defined, a function that outputs the assembler code for entry to a\n\
295 function. The prologue is responsible for setting up the stack frame,\n\
296 initializing the frame pointer register, saving registers that must be\n\
297 saved, and allocating @var{size} additional bytes of storage for the\n\
298 local variables. @var{size} is an integer. @var{file} is a stdio\n\
299 stream to which the assembler code should be output.\n\
301 The label for the beginning of the function need not be output by this\n\
302 macro. That has already been done when the macro is run.\n\
304 @findex regs_ever_live\n\
305 To determine which registers to save, the macro can refer to the array\n\
306 @code{regs_ever_live}: element @var{r} is nonzero if hard register\n\
307 @var{r} is used anywhere within the function. This implies the function\n\
308 prologue should save register @var{r}, provided it is not one of the\n\
309 call-used registers. (@code{TARGET_ASM_FUNCTION_EPILOGUE} must likewise use\n\
310 @code{regs_ever_live}.)\n\
312 On machines that have ``register windows'', the function entry code does\n\
313 not save on the stack the registers that are in the windows, even if\n\
314 they are supposed to be preserved by function calls; instead it takes\n\
315 appropriate steps to ``push'' the register stack, if any non-call-used\n\
316 registers are used in the function.\n\
318 @findex frame_pointer_needed\n\
319 On machines where functions may or may not have frame-pointers, the\n\
320 function entry code must vary accordingly; it must set up the frame\n\
321 pointer if one is wanted, and not otherwise. To determine whether a\n\
322 frame pointer is in wanted, the macro can refer to the variable\n\
323 @code{frame_pointer_needed}. The variable's value will be 1 at run\n\
324 time in a function that needs a frame pointer. @xref{Elimination}.\n\
326 The function entry code is responsible for allocating any stack space\n\
327 required for the function. This stack space consists of the regions\n\
328 listed below. In most cases, these regions are allocated in the\n\
329 order listed, with the last listed region closest to the top of the\n\
330 stack (the lowest address if @code{STACK_GROWS_DOWNWARD} is defined, and\n\
331 the highest address if it is not defined). You can use a different order\n\
332 for a machine if doing so is more convenient or required for\n\
333 compatibility reasons. Except in cases where required by standard\n\
334 or by a debugger, there is no reason why the stack layout used by GCC\n\
335 need agree with that used by other compilers for a machine.",
336 void, (FILE *file, HOST_WIDE_INT size),
337 default_function_pro_epilogue)
339 /* Output the assembler code for end of prologue. */
340 DEFHOOK
341 (function_end_prologue,
342 "If defined, a function that outputs assembler code at the end of a\n\
343 prologue. This should be used when the function prologue is being\n\
344 emitted as RTL, and you have some extra assembler that needs to be\n\
345 emitted. @xref{prologue instruction pattern}.",
346 void, (FILE *file),
347 no_asm_to_stream)
349 /* Output the assembler code for start of epilogue. */
350 DEFHOOK
351 (function_begin_epilogue,
352 "If defined, a function that outputs assembler code at the start of an\n\
353 epilogue. This should be used when the function epilogue is being\n\
354 emitted as RTL, and you have some extra assembler that needs to be\n\
355 emitted. @xref{epilogue instruction pattern}.",
356 void, (FILE *file),
357 no_asm_to_stream)
359 /* Output the assembler code for function exit. */
360 DEFHOOK
361 (function_epilogue,
362 "If defined, a function that outputs the assembler code for exit from a\n\
363 function. The epilogue is responsible for restoring the saved\n\
364 registers and stack pointer to their values when the function was\n\
365 called, and returning control to the caller. This macro takes the\n\
366 same arguments as the macro @code{TARGET_ASM_FUNCTION_PROLOGUE}, and the\n\
367 registers to restore are determined from @code{regs_ever_live} and\n\
368 @code{CALL_USED_REGISTERS} in the same way.\n\
370 On some machines, there is a single instruction that does all the work\n\
371 of returning from the function. On these machines, give that\n\
372 instruction the name @samp{return} and do not define the macro\n\
373 @code{TARGET_ASM_FUNCTION_EPILOGUE} at all.\n\
375 Do not define a pattern named @samp{return} if you want the\n\
376 @code{TARGET_ASM_FUNCTION_EPILOGUE} to be used. If you want the target\n\
377 switches to control whether return instructions or epilogues are used,\n\
378 define a @samp{return} pattern with a validity condition that tests the\n\
379 target switches appropriately. If the @samp{return} pattern's validity\n\
380 condition is false, epilogues will be used.\n\
382 On machines where functions may or may not have frame-pointers, the\n\
383 function exit code must vary accordingly. Sometimes the code for these\n\
384 two cases is completely different. To determine whether a frame pointer\n\
385 is wanted, the macro can refer to the variable\n\
386 @code{frame_pointer_needed}. The variable's value will be 1 when compiling\n\
387 a function that needs a frame pointer.\n\
389 Normally, @code{TARGET_ASM_FUNCTION_PROLOGUE} and\n\
390 @code{TARGET_ASM_FUNCTION_EPILOGUE} must treat leaf functions specially.\n\
391 The C variable @code{current_function_is_leaf} is nonzero for such a\n\
392 function. @xref{Leaf Functions}.\n\
394 On some machines, some functions pop their arguments on exit while\n\
395 others leave that for the caller to do. For example, the 68020 when\n\
396 given @option{-mrtd} pops arguments in functions that take a fixed\n\
397 number of arguments.\n\
399 @findex pops_args\n\
400 @findex crtl->args.pops_args\n\
401 Your definition of the macro @code{RETURN_POPS_ARGS} decides which\n\
402 functions pop their own arguments. @code{TARGET_ASM_FUNCTION_EPILOGUE}\n\
403 needs to know what was decided. The number of bytes of the current\n\
404 function's arguments that this function should pop is available in\n\
405 @code{crtl->args.pops_args}. @xref{Scalar Return}.",
406 void, (FILE *file, HOST_WIDE_INT size),
407 default_function_pro_epilogue)
409 /* Initialize target-specific sections. */
410 DEFHOOK
411 (init_sections,
412 "Define this hook if you need to do something special to set up the\n\
413 @file{varasm.c} sections, or if your target has some special sections\n\
414 of its own that you need to create.\n\
416 GCC calls this hook after processing the command line, but before writing\n\
417 any assembly code, and before calling any of the section-returning hooks\n\
418 described below.",
419 void, (void),
420 hook_void_void)
422 /* Tell assembler to change to section NAME with attributes FLAGS.
423 If DECL is non-NULL, it is the VAR_DECL or FUNCTION_DECL with
424 which this section is associated. */
425 DEFHOOK
426 (named_section,
427 "Output assembly directives to switch to section @var{name}. The section\n\
428 should have attributes as specified by @var{flags}, which is a bit mask\n\
429 of the @code{SECTION_*} flags defined in @file{output.h}. If @var{decl}\n\
430 is non-NULL, it is the @code{VAR_DECL} or @code{FUNCTION_DECL} with which\n\
431 this section is associated.",
432 void, (const char *name, unsigned int flags, tree decl),
433 default_no_named_section)
435 /* Tell assembler what section attributes to assign this elf section
436 declaration, using their numerical value. */
437 DEFHOOK
438 (elf_flags_numeric,
439 "This hook can be used to encode ELF section flags for which no letter\n\
440 code has been defined in the assembler. It is called by\n\
441 @code{default_asm_named_section} whenever the section flags need to be\n\
442 emitted in the assembler output. If the hook returns true, then the\n\
443 numerical value for ELF section flags should be calculated from\n\
444 @var{flags} and saved in @var{*num}; the value is printed out instead of the\n\
445 normal sequence of letter codes. If the hook is not defined, or if it\n\
446 returns false, then @var{num} is ignored and the traditional letter sequence\n\
447 is emitted.",
448 bool, (unsigned int flags, unsigned int *num),
449 hook_bool_uint_uintp_false)
451 /* Return preferred text (sub)section for function DECL.
452 Main purpose of this function is to separate cold, normal and hot
453 functions. STARTUP is true when function is known to be used only
454 at startup (from static constructors or it is main()).
455 EXIT is true when function is known to be used only at exit
456 (from static destructors).
457 Return NULL if function should go to default text section. */
458 DEFHOOK
459 (function_section,
460 "Return preferred text (sub)section for function @var{decl}.\n\
461 Main purpose of this function is to separate cold, normal and hot\n\
462 functions. @var{startup} is true when function is known to be used only\n\
463 at startup (from static constructors or it is @code{main()}).\n\
464 @var{exit} is true when function is known to be used only at exit\n\
465 (from static destructors).\n\
466 Return NULL if function should go to default text section.",
467 section *, (tree decl, enum node_frequency freq, bool startup, bool exit),
468 default_function_section)
470 /* Output the assembler code for function exit. */
471 DEFHOOK
472 (function_switched_text_sections,
473 "Used by the target to emit any assembler directives or additional\
474 labels needed when a function is partitioned between different\
475 sections. Output should be written to @var{file}. The function\
476 decl is available as @var{decl} and the new section is `cold' if\
477 @var{new_is_cold} is @code{true}.",
478 void, (FILE *file, tree decl, bool new_is_cold),
479 default_function_switched_text_sections)
481 /* Return a mask describing how relocations should be treated when
482 selecting sections. Bit 1 should be set if global relocations
483 should be placed in a read-write section; bit 0 should be set if
484 local relocations should be placed in a read-write section. */
485 DEFHOOK
486 (reloc_rw_mask,
487 "Return a mask describing how relocations should be treated when\n\
488 selecting sections. Bit 1 should be set if global relocations\n\
489 should be placed in a read-write section; bit 0 should be set if\n\
490 local relocations should be placed in a read-write section.\n\
492 The default version of this function returns 3 when @option{-fpic}\n\
493 is in effect, and 0 otherwise. The hook is typically redefined\n\
494 when the target cannot support (some kinds of) dynamic relocations\n\
495 in read-only sections even in executables.",
496 int, (void),
497 default_reloc_rw_mask)
499 /* Return a section for EXP. It may be a DECL or a constant. RELOC
500 is nonzero if runtime relocations must be applied; bit 1 will be
501 set if the runtime relocations require non-local name resolution.
502 ALIGN is the required alignment of the data. */
503 DEFHOOK
504 (select_section,
505 "Return the section into which @var{exp} should be placed. You can\n\
506 assume that @var{exp} is either a @code{VAR_DECL} node or a constant of\n\
507 some sort. @var{reloc} indicates whether the initial value of @var{exp}\n\
508 requires link-time relocations. Bit 0 is set when variable contains\n\
509 local relocations only, while bit 1 is set for global relocations.\n\
510 @var{align} is the constant alignment in bits.\n\
512 The default version of this function takes care of putting read-only\n\
513 variables in @code{readonly_data_section}.\n\
515 See also @var{USE_SELECT_SECTION_FOR_FUNCTIONS}.",
516 section *, (tree exp, int reloc, unsigned HOST_WIDE_INT align),
517 default_select_section)
519 /* Return a section for X. MODE is X's mode and ALIGN is its
520 alignment in bits. */
521 DEFHOOK
522 (select_rtx_section,
523 "Return the section into which a constant @var{x}, of mode @var{mode},\n\
524 should be placed. You can assume that @var{x} is some kind of\n\
525 constant in RTL@. The argument @var{mode} is redundant except in the\n\
526 case of a @code{const_int} rtx. @var{align} is the constant alignment\n\
527 in bits.\n\
529 The default version of this function takes care of putting symbolic\n\
530 constants in @code{flag_pic} mode in @code{data_section} and everything\n\
531 else in @code{readonly_data_section}.",
532 section *, (machine_mode mode, rtx x, unsigned HOST_WIDE_INT align),
533 default_select_rtx_section)
535 /* Select a unique section name for DECL. RELOC is the same as
536 for SELECT_SECTION. */
537 DEFHOOK
538 (unique_section,
539 "Build up a unique section name, expressed as a @code{STRING_CST} node,\n\
540 and assign it to @samp{DECL_SECTION_NAME (@var{decl})}.\n\
541 As with @code{TARGET_ASM_SELECT_SECTION}, @var{reloc} indicates whether\n\
542 the initial value of @var{exp} requires link-time relocations.\n\
544 The default version of this function appends the symbol name to the\n\
545 ELF section name that would normally be used for the symbol. For\n\
546 example, the function @code{foo} would be placed in @code{.text.foo}.\n\
547 Whatever the actual target object format, this is often good enough.",
548 void, (tree decl, int reloc),
549 default_unique_section)
551 /* Return the readonly data section associated with function DECL. */
552 DEFHOOK
553 (function_rodata_section,
554 "Return the readonly data section associated with\n\
555 @samp{DECL_SECTION_NAME (@var{decl})}.\n\
556 The default version of this function selects @code{.gnu.linkonce.r.name} if\n\
557 the function's section is @code{.gnu.linkonce.t.name}, @code{.rodata.name}\n\
558 if function is in @code{.text.name}, and the normal readonly-data section\n\
559 otherwise.",
560 section *, (tree decl),
561 default_function_rodata_section)
563 /* Nonnull if the target wants to override the default ".rodata" prefix
564 for mergeable data sections. */
565 DEFHOOKPOD
566 (mergeable_rodata_prefix,
567 "Usually, the compiler uses the prefix @code{\".rodata\"} to construct\n\
568 section names for mergeable constant data. Define this macro to override\n\
569 the string if a different section name should be used.",
570 const char *, ".rodata")
572 /* Return the section to be used for transactional memory clone tables. */
573 DEFHOOK
574 (tm_clone_table_section,
575 "Return the section that should be used for transactional memory clone\
576 tables.",
577 section *, (void), default_clone_table_section)
579 /* Output a constructor for a symbol with a given priority. */
580 DEFHOOK
581 (constructor,
582 "If defined, a function that outputs assembler code to arrange to call\n\
583 the function referenced by @var{symbol} at initialization time.\n\
585 Assume that @var{symbol} is a @code{SYMBOL_REF} for a function taking\n\
586 no arguments and with no return value. If the target supports initialization\n\
587 priorities, @var{priority} is a value between 0 and @code{MAX_INIT_PRIORITY};\n\
588 otherwise it must be @code{DEFAULT_INIT_PRIORITY}.\n\
590 If this macro is not defined by the target, a suitable default will\n\
591 be chosen if (1) the target supports arbitrary section names, (2) the\n\
592 target defines @code{CTORS_SECTION_ASM_OP}, or (3) @code{USE_COLLECT2}\n\
593 is not defined.",
594 void, (rtx symbol, int priority), NULL)
596 /* Output a destructor for a symbol with a given priority. */
597 DEFHOOK
598 (destructor,
599 "This is like @code{TARGET_ASM_CONSTRUCTOR} but used for termination\n\
600 functions rather than initialization functions.",
601 void, (rtx symbol, int priority), NULL)
603 /* Output the assembler code for a thunk function. THUNK_DECL is the
604 declaration for the thunk function itself, FUNCTION is the decl for
605 the target function. DELTA is an immediate constant offset to be
606 added to THIS. If VCALL_OFFSET is nonzero, the word at
607 *(*this + vcall_offset) should be added to THIS. */
608 DEFHOOK
609 (output_mi_thunk,
610 "A function that outputs the assembler code for a thunk\n\
611 function, used to implement C++ virtual function calls with multiple\n\
612 inheritance. The thunk acts as a wrapper around a virtual function,\n\
613 adjusting the implicit object parameter before handing control off to\n\
614 the real function.\n\
616 First, emit code to add the integer @var{delta} to the location that\n\
617 contains the incoming first argument. Assume that this argument\n\
618 contains a pointer, and is the one used to pass the @code{this} pointer\n\
619 in C++. This is the incoming argument @emph{before} the function prologue,\n\
620 e.g.@: @samp{%o0} on a sparc. The addition must preserve the values of\n\
621 all other incoming arguments.\n\
623 Then, if @var{vcall_offset} is nonzero, an additional adjustment should be\n\
624 made after adding @code{delta}. In particular, if @var{p} is the\n\
625 adjusted pointer, the following adjustment should be made:\n\
627 @smallexample\n\
628 p += (*((ptrdiff_t **)p))[vcall_offset/sizeof(ptrdiff_t)]\n\
629 @end smallexample\n\
631 After the additions, emit code to jump to @var{function}, which is a\n\
632 @code{FUNCTION_DECL}. This is a direct pure jump, not a call, and does\n\
633 not touch the return address. Hence returning from @var{FUNCTION} will\n\
634 return to whoever called the current @samp{thunk}.\n\
636 The effect must be as if @var{function} had been called directly with\n\
637 the adjusted first argument. This macro is responsible for emitting all\n\
638 of the code for a thunk function; @code{TARGET_ASM_FUNCTION_PROLOGUE}\n\
639 and @code{TARGET_ASM_FUNCTION_EPILOGUE} are not invoked.\n\
641 The @var{thunk_fndecl} is redundant. (@var{delta} and @var{function}\n\
642 have already been extracted from it.) It might possibly be useful on\n\
643 some targets, but probably not.\n\
645 If you do not define this macro, the target-independent code in the C++\n\
646 front end will generate a less efficient heavyweight thunk that calls\n\
647 @var{function} instead of jumping to it. The generic approach does\n\
648 not support varargs.",
649 void, (FILE *file, tree thunk_fndecl, HOST_WIDE_INT delta,
650 HOST_WIDE_INT vcall_offset, tree function),
651 NULL)
653 /* Determine whether output_mi_thunk would succeed. */
654 /* ??? Ideally, this hook would not exist, and success or failure
655 would be returned from output_mi_thunk directly. But there's
656 too much undo-able setup involved in invoking output_mi_thunk.
657 Could be fixed by making output_mi_thunk emit rtl instead of
658 text to the output file. */
659 DEFHOOK
660 (can_output_mi_thunk,
661 "A function that returns true if TARGET_ASM_OUTPUT_MI_THUNK would be able\n\
662 to output the assembler code for the thunk function specified by the\n\
663 arguments it is passed, and false otherwise. In the latter case, the\n\
664 generic approach will be used by the C++ front end, with the limitations\n\
665 previously exposed.",
666 bool, (const_tree thunk_fndecl, HOST_WIDE_INT delta,
667 HOST_WIDE_INT vcall_offset, const_tree function),
668 hook_bool_const_tree_hwi_hwi_const_tree_false)
670 /* Output any boilerplate text needed at the beginning of a
671 translation unit. */
672 DEFHOOK
673 (file_start,
674 "Output to @code{asm_out_file} any text which the assembler expects to\n\
675 find at the beginning of a file. The default behavior is controlled\n\
676 by two flags, documented below. Unless your target's assembler is\n\
677 quite unusual, if you override the default, you should call\n\
678 @code{default_file_start} at some point in your target hook. This\n\
679 lets other target files rely on these variables.",
680 void, (void),
681 default_file_start)
683 /* Output any boilerplate text needed at the end of a translation unit. */
684 DEFHOOK
685 (file_end,
686 "Output to @code{asm_out_file} any text which the assembler expects\n\
687 to find at the end of a file. The default is to output nothing.",
688 void, (void),
689 hook_void_void)
691 /* Output any boilerplate text needed at the beginning of an
692 LTO output stream. */
693 DEFHOOK
694 (lto_start,
695 "Output to @code{asm_out_file} any text which the assembler expects\n\
696 to find at the start of an LTO section. The default is to output\n\
697 nothing.",
698 void, (void),
699 hook_void_void)
701 /* Output any boilerplate text needed at the end of an
702 LTO output stream. */
703 DEFHOOK
704 (lto_end,
705 "Output to @code{asm_out_file} any text which the assembler expects\n\
706 to find at the end of an LTO section. The default is to output\n\
707 nothing.",
708 void, (void),
709 hook_void_void)
711 /* Output any boilerplace text needed at the end of a
712 translation unit before debug and unwind info is emitted. */
713 DEFHOOK
714 (code_end,
715 "Output to @code{asm_out_file} any text which is needed before emitting\n\
716 unwind info and debug info at the end of a file. Some targets emit\n\
717 here PIC setup thunks that cannot be emitted at the end of file,\n\
718 because they couldn't have unwind info then. The default is to output\n\
719 nothing.",
720 void, (void),
721 hook_void_void)
723 /* Output an assembler pseudo-op to declare a library function name
724 external. */
725 DEFHOOK
726 (external_libcall,
727 "This target hook is a function to output to @var{asm_out_file} an assembler\n\
728 pseudo-op to declare a library function name external. The name of the\n\
729 library function is given by @var{symref}, which is a @code{symbol_ref}.",
730 void, (rtx symref),
731 default_external_libcall)
733 /* Output an assembler directive to mark decl live. This instructs
734 linker to not dead code strip this symbol. */
735 DEFHOOK
736 (mark_decl_preserved,
737 "This target hook is a function to output to @var{asm_out_file} an assembler\n\
738 directive to annotate @var{symbol} as used. The Darwin target uses the\n\
739 .no_dead_code_strip directive.",
740 void, (const char *symbol),
741 hook_void_constcharptr)
743 /* Output a record of the command line switches that have been passed. */
744 DEFHOOK
745 (record_gcc_switches,
746 "Provides the target with the ability to record the gcc command line\n\
747 switches that have been passed to the compiler, and options that are\n\
748 enabled. The @var{type} argument specifies what is being recorded.\n\
749 It can take the following values:\n\
751 @table @gcctabopt\n\
752 @item SWITCH_TYPE_PASSED\n\
753 @var{text} is a command line switch that has been set by the user.\n\
755 @item SWITCH_TYPE_ENABLED\n\
756 @var{text} is an option which has been enabled. This might be as a\n\
757 direct result of a command line switch, or because it is enabled by\n\
758 default or because it has been enabled as a side effect of a different\n\
759 command line switch. For example, the @option{-O2} switch enables\n\
760 various different individual optimization passes.\n\
762 @item SWITCH_TYPE_DESCRIPTIVE\n\
763 @var{text} is either NULL or some descriptive text which should be\n\
764 ignored. If @var{text} is NULL then it is being used to warn the\n\
765 target hook that either recording is starting or ending. The first\n\
766 time @var{type} is SWITCH_TYPE_DESCRIPTIVE and @var{text} is NULL, the\n\
767 warning is for start up and the second time the warning is for\n\
768 wind down. This feature is to allow the target hook to make any\n\
769 necessary preparations before it starts to record switches and to\n\
770 perform any necessary tidying up after it has finished recording\n\
771 switches.\n\
773 @item SWITCH_TYPE_LINE_START\n\
774 This option can be ignored by this target hook.\n\
776 @item SWITCH_TYPE_LINE_END\n\
777 This option can be ignored by this target hook.\n\
778 @end table\n\
780 The hook's return value must be zero. Other return values may be\n\
781 supported in the future.\n\
783 By default this hook is set to NULL, but an example implementation is\n\
784 provided for ELF based targets. Called @var{elf_record_gcc_switches},\n\
785 it records the switches as ASCII text inside a new, string mergeable\n\
786 section in the assembler output file. The name of the new section is\n\
787 provided by the @code{TARGET_ASM_RECORD_GCC_SWITCHES_SECTION} target\n\
788 hook.",
789 int, (print_switch_type type, const char *text),
790 NULL)
792 /* The name of the section that the example ELF implementation of
793 record_gcc_switches will use to store the information. Target
794 specific versions of record_gcc_switches may or may not use
795 this information. */
796 DEFHOOKPOD
797 (record_gcc_switches_section,
798 "This is the name of the section that will be created by the example\n\
799 ELF implementation of the @code{TARGET_ASM_RECORD_GCC_SWITCHES} target\n\
800 hook.",
801 const char *, ".GCC.command.line")
803 /* Output the definition of a section anchor. */
804 DEFHOOK
805 (output_anchor,
806 "Write the assembly code to define section anchor @var{x}, which is a\n\
807 @code{SYMBOL_REF} for which @samp{SYMBOL_REF_ANCHOR_P (@var{x})} is true.\n\
808 The hook is called with the assembly output position set to the beginning\n\
809 of @code{SYMBOL_REF_BLOCK (@var{x})}.\n\
811 If @code{ASM_OUTPUT_DEF} is available, the hook's default definition uses\n\
812 it to define the symbol as @samp{. + SYMBOL_REF_BLOCK_OFFSET (@var{x})}.\n\
813 If @code{ASM_OUTPUT_DEF} is not available, the hook's default definition\n\
814 is @code{NULL}, which disables the use of section anchors altogether.",
815 void, (rtx x),
816 default_asm_output_anchor)
818 DEFHOOK
819 (output_ident,
820 "Output a string based on @var{name}, suitable for the @samp{#ident} \
821 directive, or the equivalent directive or pragma in non-C-family languages. \
822 If this hook is not defined, nothing is output for the @samp{#ident} \
823 directive.",
824 void, (const char *name),
825 hook_void_constcharptr)
827 /* Output a DTP-relative reference to a TLS symbol. */
828 DEFHOOK
829 (output_dwarf_dtprel,
830 "If defined, this target hook is a function which outputs a DTP-relative\n\
831 reference to the given TLS symbol of the specified size.",
832 void, (FILE *file, int size, rtx x),
833 NULL)
835 /* Some target machines need to postscan each insn after it is output. */
836 DEFHOOK
837 (final_postscan_insn,
838 "If defined, this target hook is a function which is executed just after the\n\
839 output of assembler code for @var{insn}, to change the mode of the assembler\n\
840 if necessary.\n\
842 Here the argument @var{opvec} is the vector containing the operands\n\
843 extracted from @var{insn}, and @var{noperands} is the number of\n\
844 elements of the vector which contain meaningful data for this insn.\n\
845 The contents of this vector are what was used to convert the insn\n\
846 template into assembler code, so you can change the assembler mode\n\
847 by checking the contents of the vector.",
848 void, (FILE *file, rtx_insn *insn, rtx *opvec, int noperands),
849 NULL)
851 /* Emit the trampoline template. This hook may be NULL. */
852 DEFHOOK
853 (trampoline_template,
854 "This hook is called by @code{assemble_trampoline_template} to output,\n\
855 on the stream @var{f}, assembler code for a block of data that contains\n\
856 the constant parts of a trampoline. This code should not include a\n\
857 label---the label is taken care of automatically.\n\
859 If you do not define this hook, it means no template is needed\n\
860 for the target. Do not define this hook on systems where the block move\n\
861 code to copy the trampoline into place would be larger than the code\n\
862 to generate it on the spot.",
863 void, (FILE *f),
864 NULL)
866 DEFHOOK
867 (output_source_filename,
868 "Output COFF information or DWARF debugging information which indicates\
869 that filename @var{name} is the current source file to the stdio\
870 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)
877 DEFHOOK
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
893 initializers. */
894 #undef HOOK_PREFIX
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. */
900 DEFHOOK_UNDOC
901 (print_operand,
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. */
909 DEFHOOK_UNDOC
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,
918 not this hook. */
919 DEFHOOK_UNDOC
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. */
927 DEFHOOK
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. */
941 #undef HOOK_PREFIX
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. */
948 DEFHOOK
949 (adjust_cost,
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,
963 unsigned int dw),
964 NULL)
966 /* Adjust the priority of an insn as you see fit. Returns the new priority. */
967 DEFHOOK
968 (adjust_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. */
979 DEFHOOK
980 (issue_rate,
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}.",
990 int, (void), NULL)
992 /* Calculate how much this insn affects how many more insns we
993 can emit this cycle. Default is they all cost the same. */
994 DEFHOOK
995 (variable_issue,
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\
1006 was scheduled.",
1007 int, (FILE *file, int verbose, rtx_insn *insn, int more), NULL)
1009 /* Initialize machine-dependent scheduling code. */
1010 DEFHOOK
1011 (init,
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. */
1022 DEFHOOK
1023 (finish,
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. */
1033 DEFHOOK
1034 (init_global,
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. */
1042 DEFHOOK
1043 (finish_global,
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. */
1051 DEFHOOK
1052 (reorder,
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)
1069 DEFHOOK
1070 (reorder2,
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)
1081 DEFHOOK
1082 (macro_fusion_p,
1083 "This hook is used to check whether target platform supports macro fusion.",
1084 bool, (void), NULL)
1086 DEFHOOK
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). */
1099 DEFHOOK
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\
1107 calculated.",
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. */
1120 DEFHOOK
1121 (init_dfa_pre_cycle_insn,
1122 "The hook can be used to initialize data used by the previous hook.",
1123 void, (void), NULL)
1125 DEFHOOK
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.",
1134 rtx, (void), NULL)
1136 DEFHOOK
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.",
1140 void, (void), NULL)
1142 DEFHOOK
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. */
1154 DEFHOOK
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.",
1160 void, (void), NULL)
1162 DEFHOOK
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.",
1168 void, (void), NULL)
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. */
1177 DEFHOOK
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.",
1205 int, (void), NULL)
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. */
1211 DEFHOOK
1212 (first_cycle_multipass_dfa_lookahead_guard,
1213 "\n\
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
1229 scheduling.
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. */
1237 DEFHOOK
1238 (first_cycle_multipass_begin,
1239 "This hook prepares the target backend for a new round of multipass\n\
1240 scheduling.",
1241 void, (void *data, signed char *ready_try, int n_ready, bool first_cycle_insn_p),
1242 NULL)
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. */
1254 DEFHOOK
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
1264 described in DFA.
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. */
1269 DEFHOOK
1270 (first_cycle_multipass_backtrack,
1271 "This is called when multipass scheduling backtracks from evaluation of\n\
1272 an instruction.",
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.
1277 DATA is a pointer.
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. */
1283 DEFHOOK
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. */
1294 DEFHOOK
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. */
1304 DEFHOOK
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. */
1320 DEFHOOK
1321 (dfa_new_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),
1334 NULL)
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). */
1345 DEFHOOK
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. */
1370 DEFHOOK
1371 (h_i_d_extended,
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.",
1375 void, (void), NULL)
1377 /* Next 5 functions are for multi-point scheduling. */
1379 /* Allocate memory for scheduler context. */
1380 DEFHOOK
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. */
1386 DEFHOOK
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. */
1394 DEFHOOK
1395 (set_sched_context,
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. */
1400 DEFHOOK
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. */
1406 DEFHOOK
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).
1416 It should return
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
1420 generated one. */
1421 DEFHOOK
1422 (speculate_insn,
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. */
1436 DEFHOOK
1437 (needs_block_p,
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
1445 instruction.
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. */
1450 DEFHOOK
1451 (gen_spec_check,
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. */
1465 DEFHOOK
1466 (set_sched_flags,
1467 "This hook is used by the insn scheduler to find out what features should be\n\
1468 enabled/used.\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)
1473 DEFHOOK_UNDOC
1474 (get_insn_spec_ds,
1475 "Return speculation types of instruction @var{insn}.",
1476 unsigned int, (rtx_insn *insn), NULL)
1478 DEFHOOK_UNDOC
1479 (get_insn_checked_ds,
1480 "Return speculation types that are checked for instruction @var{insn}",
1481 unsigned int, (rtx_insn *insn), NULL)
1483 DEFHOOK_UNDOC
1484 (skip_rtx_p,
1485 "Return bool if rtx scanning should just skip current layer and\
1486 advance to the inner rtxes.",
1487 bool, (const_rtx x), NULL)
1489 /* The following member value is a pointer to a function that provides
1490 information about the target resource-based lower bound which is
1491 used by the swing modulo scheduler. The parameter is a pointer
1492 to ddg variable. */
1493 DEFHOOK
1494 (sms_res_mii,
1495 "This hook is called by the swing modulo scheduler to calculate a\n\
1496 resource-based lower bound which is based on the resources available in\n\
1497 the machine and the resources required by each instruction. The target\n\
1498 backend can use @var{g} to calculate such bound. A very simple lower\n\
1499 bound will be used in case this hook is not implemented: the total number\n\
1500 of instructions divided by the issue rate.",
1501 int, (struct ddg *g), NULL)
1503 /* The following member value is a function that initializes dispatch
1504 schedling and adds instructions to dispatch window according to its
1505 parameters. */
1506 DEFHOOK
1507 (dispatch_do,
1508 "This hook is called by Haifa Scheduler. It performs the operation specified\n\
1509 in its second parameter.",
1510 void, (rtx_insn *insn, int x),
1511 hook_void_rtx_insn_int)
1513 /* The following member value is a a function that returns true is
1514 dispatch schedling is supported in hardware and condition passed
1515 as the second parameter is true. */
1516 DEFHOOK
1517 (dispatch,
1518 "This hook is called by Haifa Scheduler. It returns true if dispatch scheduling\n\
1519 is supported in hardware and the condition specified in the parameter is true.",
1520 bool, (rtx_insn *insn, int x),
1521 hook_bool_rtx_insn_int_false)
1523 DEFHOOKPOD
1524 (exposed_pipeline,
1525 "True if the processor has an exposed pipeline, which means that not just\n\
1526 the order of instructions is important for correctness when scheduling, but\n\
1527 also the latencies of operations.",
1528 bool, false)
1530 /* The following member value is a function that returns number
1531 of operations reassociator should try to put in parallel for
1532 statements of the given type. By default 1 is used. */
1533 DEFHOOK
1534 (reassociation_width,
1535 "This hook is called by tree reassociator to determine a level of\n\
1536 parallelism required in output calculations chain.",
1537 int, (unsigned int opc, machine_mode mode),
1538 hook_int_uint_mode_1)
1540 /* The following member value is a function that returns priority for
1541 fusion of each instruction via pointer parameters. */
1542 DEFHOOK
1543 (fusion_priority,
1544 "This hook is called by scheduling fusion pass. It calculates fusion\n\
1545 priorities for each instruction passed in by parameter. The priorities\n\
1546 are returned via pointer parameters.\n\
1548 @var{insn} is the instruction whose priorities need to be calculated.\n\
1549 @var{max_pri} is the maximum priority can be returned in any cases.\n\
1550 @var{fusion_pri} is the pointer parameter through which @var{insn}'s\n\
1551 fusion priority should be calculated and returned.\n\
1552 @var{pri} is the pointer parameter through which @var{insn}'s priority\n\
1553 should be calculated and returned.\n\
1555 Same @var{fusion_pri} should be returned for instructions which should\n\
1556 be scheduled together. Different @var{pri} should be returned for\n\
1557 instructions with same @var{fusion_pri}. @var{fusion_pri} is the major\n\
1558 sort key, @var{pri} is the minor sort key. All instructions will be\n\
1559 scheduled according to the two priorities. All priorities calculated\n\
1560 should be between 0 (exclusive) and @var{max_pri} (inclusive). To avoid\n\
1561 false dependencies, @var{fusion_pri} of instructions which need to be\n\
1562 scheduled together should be smaller than @var{fusion_pri} of irrelevant\n\
1563 instructions.\n\
1565 Given below example:\n\
1567 @smallexample\n\
1568 ldr r10, [r1, 4]\n\
1569 add r4, r4, r10\n\
1570 ldr r15, [r2, 8]\n\
1571 sub r5, r5, r15\n\
1572 ldr r11, [r1, 0]\n\
1573 add r4, r4, r11\n\
1574 ldr r16, [r2, 12]\n\
1575 sub r5, r5, r16\n\
1576 @end smallexample\n\
1578 On targets like ARM/AArch64, the two pairs of consecutive loads should be\n\
1579 merged. Since peephole2 pass can't help in this case unless consecutive\n\
1580 loads are actually next to each other in instruction flow. That's where\n\
1581 this scheduling fusion pass works. This hook calculates priority for each\n\
1582 instruction based on its fustion type, like:\n\
1584 @smallexample\n\
1585 ldr r10, [r1, 4] ; fusion_pri=99, pri=96\n\
1586 add r4, r4, r10 ; fusion_pri=100, pri=100\n\
1587 ldr r15, [r2, 8] ; fusion_pri=98, pri=92\n\
1588 sub r5, r5, r15 ; fusion_pri=100, pri=100\n\
1589 ldr r11, [r1, 0] ; fusion_pri=99, pri=100\n\
1590 add r4, r4, r11 ; fusion_pri=100, pri=100\n\
1591 ldr r16, [r2, 12] ; fusion_pri=98, pri=88\n\
1592 sub r5, r5, r16 ; fusion_pri=100, pri=100\n\
1593 @end smallexample\n\
1595 Scheduling fusion pass then sorts all ready to issue instructions according\n\
1596 to the priorities. As a result, instructions of same fusion type will be\n\
1597 pushed together in instruction flow, like:\n\
1599 @smallexample\n\
1600 ldr r11, [r1, 0]\n\
1601 ldr r10, [r1, 4]\n\
1602 ldr r15, [r2, 8]\n\
1603 ldr r16, [r2, 12]\n\
1604 add r4, r4, r10\n\
1605 sub r5, r5, r15\n\
1606 add r4, r4, r11\n\
1607 sub r5, r5, r16\n\
1608 @end smallexample\n\
1610 Now peephole2 pass can simply merge the two pairs of loads.\n\
1612 Since scheduling fusion pass relies on peephole2 to do real fusion\n\
1613 work, it is only enabled by default when peephole2 is in effect.\n\
1615 This is firstly introduced on ARM/AArch64 targets, please refer to\n\
1616 the hook implementation for how different fusion types are supported.",
1617 void, (rtx_insn *insn, int max_pri, int *fusion_pri, int *pri), NULL)
1619 HOOK_VECTOR_END (sched)
1621 /* Functions relating to OpenMP and Cilk Plus SIMD clones. */
1622 #undef HOOK_PREFIX
1623 #define HOOK_PREFIX "TARGET_SIMD_CLONE_"
1624 HOOK_VECTOR (TARGET_SIMD_CLONE, simd_clone)
1626 DEFHOOK
1627 (compute_vecsize_and_simdlen,
1628 "This hook should set @var{vecsize_mangle}, @var{vecsize_int}, @var{vecsize_float}\n\
1629 fields in @var{simd_clone} structure pointed by @var{clone_info} argument and also\n\
1630 @var{simdlen} field if it was previously 0.\n\
1631 The hook should return 0 if SIMD clones shouldn't be emitted,\n\
1632 or number of @var{vecsize_mangle} variants that should be emitted.",
1633 int, (struct cgraph_node *, struct cgraph_simd_clone *, tree, int), NULL)
1635 DEFHOOK
1636 (adjust,
1637 "This hook should add implicit @code{attribute(target(\"...\"))} attribute\n\
1638 to SIMD clone @var{node} if needed.",
1639 void, (struct cgraph_node *), NULL)
1641 DEFHOOK
1642 (usable,
1643 "This hook should return -1 if SIMD clone @var{node} shouldn't be used\n\
1644 in vectorized loops in current function, or non-negative number if it is\n\
1645 usable. In that case, the smaller the number is, the more desirable it is\n\
1646 to use it.",
1647 int, (struct cgraph_node *), NULL)
1649 HOOK_VECTOR_END (simd_clone)
1651 /* Functions relating to OpenMP SIMT vectorization transform. */
1652 #undef HOOK_PREFIX
1653 #define HOOK_PREFIX "TARGET_SIMT_"
1654 HOOK_VECTOR (TARGET_SIMT, simt)
1656 DEFHOOK
1657 (vf,
1658 "Return number of threads in SIMT thread group on the target.",
1659 int, (void), NULL)
1661 HOOK_VECTOR_END (simt)
1663 /* Functions relating to openacc. */
1664 #undef HOOK_PREFIX
1665 #define HOOK_PREFIX "TARGET_GOACC_"
1666 HOOK_VECTOR (TARGET_GOACC, goacc)
1668 DEFHOOK
1669 (validate_dims,
1670 "This hook should check the launch dimensions provided for an OpenACC\n\
1671 compute region, or routine. Defaulted values are represented as -1\n\
1672 and non-constant values as 0. The @var{fn_level} is negative for the\n\
1673 function corresponding to the compute region. For a routine is is the\n\
1674 outermost level at which partitioned execution may be spawned. The hook\n\
1675 should verify non-default values. If DECL is NULL, global defaults\n\
1676 are being validated and unspecified defaults should be filled in.\n\
1677 Diagnostics should be issued as appropriate. Return\n\
1678 true, if changes have been made. You must override this hook to\n\
1679 provide dimensions larger than 1.",
1680 bool, (tree decl, int *dims, int fn_level),
1681 default_goacc_validate_dims)
1683 DEFHOOK
1684 (dim_limit,
1685 "This hook should return the maximum size of a particular dimension,\n\
1686 or zero if unbounded.",
1687 int, (int axis),
1688 default_goacc_dim_limit)
1690 DEFHOOK
1691 (fork_join,
1692 "This hook can be used to convert IFN_GOACC_FORK and IFN_GOACC_JOIN\n\
1693 function calls to target-specific gimple, or indicate whether they\n\
1694 should be retained. It is executed during the oacc_device_lower pass.\n\
1695 It should return true, if the call should be retained. It should\n\
1696 return false, if it is to be deleted (either because target-specific\n\
1697 gimple has been inserted before it, or there is no need for it).\n\
1698 The default hook returns false, if there are no RTL expanders for them.",
1699 bool, (gcall *call, const int *dims, bool is_fork),
1700 default_goacc_fork_join)
1702 DEFHOOK
1703 (reduction,
1704 "This hook is used by the oacc_transform pass to expand calls to the\n\
1705 @var{GOACC_REDUCTION} internal function, into a sequence of gimple\n\
1706 instructions. @var{call} is gimple statement containing the call to\n\
1707 the function. This hook removes statement @var{call} after the\n\
1708 expanded sequence has been inserted. This hook is also responsible\n\
1709 for allocating any storage for reductions when necessary.",
1710 void, (gcall *call),
1711 default_goacc_reduction)
1713 HOOK_VECTOR_END (goacc)
1715 /* Functions relating to vectorization. */
1716 #undef HOOK_PREFIX
1717 #define HOOK_PREFIX "TARGET_VECTORIZE_"
1718 HOOK_VECTOR (TARGET_VECTORIZE, vectorize)
1720 /* The following member value is a pointer to a function called
1721 by the vectorizer, and return the decl of the target builtin
1722 function. */
1723 DEFHOOK
1724 (builtin_mask_for_load,
1725 "This hook should return the DECL of a function @var{f} that given an\n\
1726 address @var{addr} as an argument returns a mask @var{m} that can be\n\
1727 used to extract from two vectors the relevant data that resides in\n\
1728 @var{addr} in case @var{addr} is not properly aligned.\n\
1730 The autovectorizer, when vectorizing a load operation from an address\n\
1731 @var{addr} that may be unaligned, will generate two vector loads from\n\
1732 the two aligned addresses around @var{addr}. It then generates a\n\
1733 @code{REALIGN_LOAD} operation to extract the relevant data from the\n\
1734 two loaded vectors. The first two arguments to @code{REALIGN_LOAD},\n\
1735 @var{v1} and @var{v2}, are the two vectors, each of size @var{VS}, and\n\
1736 the third argument, @var{OFF}, defines how the data will be extracted\n\
1737 from these two vectors: if @var{OFF} is 0, then the returned vector is\n\
1738 @var{v2}; otherwise, the returned vector is composed from the last\n\
1739 @var{VS}-@var{OFF} elements of @var{v1} concatenated to the first\n\
1740 @var{OFF} elements of @var{v2}.\n\
1742 If this hook is defined, the autovectorizer will generate a call\n\
1743 to @var{f} (using the DECL tree that this hook returns) and will\n\
1744 use the return value of @var{f} as the argument @var{OFF} to\n\
1745 @code{REALIGN_LOAD}. Therefore, the mask @var{m} returned by @var{f}\n\
1746 should comply with the semantics expected by @code{REALIGN_LOAD}\n\
1747 described above.\n\
1748 If this hook is not defined, then @var{addr} will be used as\n\
1749 the argument @var{OFF} to @code{REALIGN_LOAD}, in which case the low\n\
1750 log2(@var{VS}) @minus{} 1 bits of @var{addr} will be considered.",
1751 tree, (void), NULL)
1753 /* Returns a built-in function that realizes the vectorized version of
1754 a target-independent function, or NULL_TREE if not available. */
1755 DEFHOOK
1756 (builtin_vectorized_function,
1757 "This hook should return the decl of a function that implements the\n\
1758 vectorized variant of the function with the @code{combined_fn} code\n\
1759 @var{code} or @code{NULL_TREE} if such a function is not available.\n\
1760 The return type of the vectorized function shall be of vector type\n\
1761 @var{vec_type_out} and the argument types should be @var{vec_type_in}.",
1762 tree, (unsigned code, tree vec_type_out, tree vec_type_in),
1763 default_builtin_vectorized_function)
1765 /* Returns a built-in function that realizes the vectorized version of
1766 a target-specific function, or NULL_TREE if not available. */
1767 DEFHOOK
1768 (builtin_md_vectorized_function,
1769 "This hook should return the decl of a function that implements the\n\
1770 vectorized variant of target built-in function @code{fndecl}. The\n\
1771 return type of the vectorized function shall be of vector type\n\
1772 @var{vec_type_out} and the argument types should be @var{vec_type_in}.",
1773 tree, (tree fndecl, tree vec_type_out, tree vec_type_in),
1774 default_builtin_md_vectorized_function)
1776 /* Returns a function declaration for a builtin that realizes the
1777 vector conversion, or NULL_TREE if not available. */
1778 DEFHOOK
1779 (builtin_conversion,
1780 "This hook should return the DECL of a function that implements conversion of the\n\
1781 input vector of type @var{src_type} to type @var{dest_type}.\n\
1782 The value of @var{code} is one of the enumerators in @code{enum tree_code} and\n\
1783 specifies how the conversion is to be applied\n\
1784 (truncation, rounding, etc.).\n\
1786 If this hook is defined, the autovectorizer will use the\n\
1787 @code{TARGET_VECTORIZE_BUILTIN_CONVERSION} target hook when vectorizing\n\
1788 conversion. Otherwise, it will return @code{NULL_TREE}.",
1789 tree, (unsigned code, tree dest_type, tree src_type),
1790 default_builtin_vectorized_conversion)
1792 /* Cost of different vector/scalar statements in vectorization cost
1793 model. In case of misaligned vector loads and stores the cost depends
1794 on the data type and misalignment value. */
1795 DEFHOOK
1796 (builtin_vectorization_cost,
1797 "Returns cost of different scalar or vector statements for vectorization cost model.\n\
1798 For vector memory operations the cost may depend on type (@var{vectype}) and\n\
1799 misalignment value (@var{misalign}).",
1800 int, (enum vect_cost_for_stmt type_of_cost, tree vectype, int misalign),
1801 default_builtin_vectorization_cost)
1803 /* Return true if vector alignment is reachable (by peeling N
1804 iterations) for the given scalar type. */
1805 DEFHOOK
1806 (vector_alignment_reachable,
1807 "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.",
1808 bool, (const_tree type, bool is_packed),
1809 default_builtin_vector_alignment_reachable)
1811 /* Return true if a vector created for vec_perm_const is valid.
1812 A NULL indicates that all constants are valid permutations. */
1813 DEFHOOK
1814 (vec_perm_const_ok,
1815 "Return true if a vector created for @code{vec_perm_const} is valid.",
1816 bool, (machine_mode, const unsigned char *sel),
1817 NULL)
1819 /* Return true if the target supports misaligned store/load of a
1820 specific factor denoted in the third parameter. The last parameter
1821 is true if the access is defined in a packed struct. */
1822 DEFHOOK
1823 (support_vector_misalignment,
1824 "This hook should return true if the target supports misaligned vector\n\
1825 store/load of a specific factor denoted in the @var{misalignment}\n\
1826 parameter. The vector store/load should be of machine mode @var{mode} and\n\
1827 the elements in the vectors should be of type @var{type}. @var{is_packed}\n\
1828 parameter is true if the memory access is defined in a packed struct.",
1829 bool,
1830 (machine_mode mode, const_tree type, int misalignment, bool is_packed),
1831 default_builtin_support_vector_misalignment)
1833 /* Returns the preferred mode for SIMD operations for the specified
1834 scalar mode. */
1835 DEFHOOK
1836 (preferred_simd_mode,
1837 "This hook should return the preferred mode for vectorizing scalar\n\
1838 mode @var{mode}. The default is\n\
1839 equal to @code{word_mode}, because the vectorizer can do some\n\
1840 transformations even in absence of specialized @acronym{SIMD} hardware.",
1841 machine_mode,
1842 (machine_mode mode),
1843 default_preferred_simd_mode)
1845 /* Returns a mask of vector sizes to iterate over when auto-vectorizing
1846 after processing the preferred one derived from preferred_simd_mode. */
1847 DEFHOOK
1848 (autovectorize_vector_sizes,
1849 "This hook should return a mask of sizes that should be iterated over\n\
1850 after trying to autovectorize using the vector size derived from the\n\
1851 mode returned by @code{TARGET_VECTORIZE_PREFERRED_SIMD_MODE}.\n\
1852 The default is zero which means to not iterate over other vector sizes.",
1853 unsigned int,
1854 (void),
1855 default_autovectorize_vector_sizes)
1857 /* Function to get a target mode for a vector mask. */
1858 DEFHOOK
1859 (get_mask_mode,
1860 "This hook returns mode to be used for a mask to be used for a vector\n\
1861 of specified @var{length} with @var{nunits} elements. By default an integer\n\
1862 vector mode of a proper size is returned.",
1863 machine_mode,
1864 (unsigned nunits, unsigned length),
1865 default_get_mask_mode)
1867 /* Target builtin that implements vector gather operation. */
1868 DEFHOOK
1869 (builtin_gather,
1870 "Target builtin that implements vector gather operation. @var{mem_vectype}\n\
1871 is the vector type of the load and @var{index_type} is scalar type of\n\
1872 the index, scaled by @var{scale}.\n\
1873 The default is @code{NULL_TREE} which means to not vectorize gather\n\
1874 loads.",
1875 tree,
1876 (const_tree mem_vectype, const_tree index_type, int scale),
1877 NULL)
1879 /* Target builtin that implements vector scatter operation. */
1880 DEFHOOK
1881 (builtin_scatter,
1882 "Target builtin that implements vector scatter operation. @var{vectype}\n\
1883 is the vector type of the store and @var{index_type} is scalar type of\n\
1884 the index, scaled by @var{scale}.\n\
1885 The default is @code{NULL_TREE} which means to not vectorize scatter\n\
1886 stores.",
1887 tree,
1888 (const_tree vectype, const_tree index_type, int scale),
1889 NULL)
1891 /* Target function to initialize the cost model for a loop or block. */
1892 DEFHOOK
1893 (init_cost,
1894 "This hook should initialize target-specific data structures in preparation "
1895 "for modeling the costs of vectorizing a loop or basic block. The default "
1896 "allocates three unsigned integers for accumulating costs for the prologue, "
1897 "body, and epilogue of the loop or basic block. If @var{loop_info} is "
1898 "non-NULL, it identifies the loop being vectorized; otherwise a single block "
1899 "is being vectorized.",
1900 void *,
1901 (struct loop *loop_info),
1902 default_init_cost)
1904 /* Target function to record N statements of the given kind using the
1905 given vector type within the cost model data for the current loop or
1906 block. */
1907 DEFHOOK
1908 (add_stmt_cost,
1909 "This hook should update the target-specific @var{data} in response to "
1910 "adding @var{count} copies of the given @var{kind} of statement to a "
1911 "loop or basic block. The default adds the builtin vectorizer cost for "
1912 "the copies of the statement to the accumulator specified by @var{where}, "
1913 "(the prologue, body, or epilogue) and returns the amount added. The "
1914 "return value should be viewed as a tentative cost that may later be "
1915 "revised.",
1916 unsigned,
1917 (void *data, int count, enum vect_cost_for_stmt kind,
1918 struct _stmt_vec_info *stmt_info, int misalign,
1919 enum vect_cost_model_location where),
1920 default_add_stmt_cost)
1922 /* Target function to calculate the total cost of the current vectorized
1923 loop or block. */
1924 DEFHOOK
1925 (finish_cost,
1926 "This hook should complete calculations of the cost of vectorizing a loop "
1927 "or basic block based on @var{data}, and return the prologue, body, and "
1928 "epilogue costs as unsigned integers. The default returns the value of "
1929 "the three accumulators.",
1930 void,
1931 (void *data, unsigned *prologue_cost, unsigned *body_cost,
1932 unsigned *epilogue_cost),
1933 default_finish_cost)
1935 /* Function to delete target-specific cost modeling data. */
1936 DEFHOOK
1937 (destroy_cost_data,
1938 "This hook should release @var{data} and any related data structures "
1939 "allocated by TARGET_VECTORIZE_INIT_COST. The default releases the "
1940 "accumulator.",
1941 void,
1942 (void *data),
1943 default_destroy_cost_data)
1945 HOOK_VECTOR_END (vectorize)
1947 #undef HOOK_PREFIX
1948 #define HOOK_PREFIX "TARGET_"
1950 DEFHOOK
1951 (record_offload_symbol,
1952 "Used when offloaded functions are seen in the compilation unit and no named\n\
1953 sections are available. It is called once for each symbol that must be\n\
1954 recorded in the offload function and variable table.",
1955 void, (tree),
1956 hook_void_tree)
1958 DEFHOOKPOD
1959 (absolute_biggest_alignment,
1960 "If defined, this target hook specifies the absolute biggest alignment\n\
1961 that a type or variable can have on this machine, otherwise,\n\
1962 @code{BIGGEST_ALIGNMENT} is used.",
1963 HOST_WIDE_INT, BIGGEST_ALIGNMENT)
1965 /* Allow target specific overriding of option settings after options have
1966 been changed by an attribute or pragma or when it is reset at the
1967 end of the code affected by an attribute or pragma. */
1968 DEFHOOK
1969 (override_options_after_change,
1970 "This target function is similar to the hook @code{TARGET_OPTION_OVERRIDE}\n\
1971 but is called when the optimize level is changed via an attribute or\n\
1972 pragma or when it is reset at the end of the code affected by the\n\
1973 attribute or pragma. It is not called at the beginning of compilation\n\
1974 when @code{TARGET_OPTION_OVERRIDE} is called so if you want to perform these\n\
1975 actions then, you should have @code{TARGET_OPTION_OVERRIDE} call\n\
1976 @code{TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE}.",
1977 void, (void),
1978 hook_void_void)
1980 DEFHOOK
1981 (offload_options,
1982 "Used when writing out the list of options into an LTO file. It should\n\
1983 translate any relevant target-specific options (such as the ABI in use)\n\
1984 into one of the @option{-foffload} options that exist as a common interface\n\
1985 to express such options. It should return a string containing these options,\n\
1986 separated by spaces, which the caller will free.\n",
1987 char *, (void), hook_charptr_void_null)
1989 DEFHOOK_UNDOC
1990 (eh_return_filter_mode,
1991 "Return machine mode for filter value.",
1992 machine_mode, (void),
1993 default_eh_return_filter_mode)
1995 /* Return machine mode for libgcc expanded cmp instructions. */
1996 DEFHOOK
1997 (libgcc_cmp_return_mode,
1998 "This target hook should return the mode to be used for the return value\n\
1999 of compare instructions expanded to libgcc calls. If not defined\n\
2000 @code{word_mode} is returned which is the right choice for a majority of\n\
2001 targets.",
2002 machine_mode, (void),
2003 default_libgcc_cmp_return_mode)
2005 /* Return machine mode for libgcc expanded shift instructions. */
2006 DEFHOOK
2007 (libgcc_shift_count_mode,
2008 "This target hook should return the mode to be used for the shift count operand\n\
2009 of shift instructions expanded to libgcc calls. If not defined\n\
2010 @code{word_mode} is returned which is the right choice for a majority of\n\
2011 targets.",
2012 machine_mode, (void),
2013 default_libgcc_shift_count_mode)
2015 /* Return machine mode to be used for _Unwind_Word type. */
2016 DEFHOOK
2017 (unwind_word_mode,
2018 "Return machine mode to be used for @code{_Unwind_Word} type.\n\
2019 The default is to use @code{word_mode}.",
2020 machine_mode, (void),
2021 default_unwind_word_mode)
2023 /* Given two decls, merge their attributes and return the result. */
2024 DEFHOOK
2025 (merge_decl_attributes,
2026 "Define this target hook if the merging of decl attributes needs special\n\
2027 handling. If defined, the result is a list of the combined\n\
2028 @code{DECL_ATTRIBUTES} of @var{olddecl} and @var{newdecl}.\n\
2029 @var{newdecl} is a duplicate declaration of @var{olddecl}. Examples of\n\
2030 when this is needed are when one attribute overrides another, or when an\n\
2031 attribute is nullified by a subsequent definition. This function may\n\
2032 call @code{merge_attributes} to handle machine-independent merging.\n\
2034 @findex TARGET_DLLIMPORT_DECL_ATTRIBUTES\n\
2035 If the only target-specific handling you require is @samp{dllimport}\n\
2036 for Microsoft Windows targets, you should define the macro\n\
2037 @code{TARGET_DLLIMPORT_DECL_ATTRIBUTES} to @code{1}. The compiler\n\
2038 will then define a function called\n\
2039 @code{merge_dllimport_decl_attributes} which can then be defined as\n\
2040 the expansion of @code{TARGET_MERGE_DECL_ATTRIBUTES}. You can also\n\
2041 add @code{handle_dll_attribute} in the attribute table for your port\n\
2042 to perform initial processing of the @samp{dllimport} and\n\
2043 @samp{dllexport} attributes. This is done in @file{i386/cygwin.h} and\n\
2044 @file{i386/i386.c}, for example.",
2045 tree, (tree olddecl, tree newdecl),
2046 merge_decl_attributes)
2048 /* Given two types, merge their attributes and return the result. */
2049 DEFHOOK
2050 (merge_type_attributes,
2051 "Define this target hook if the merging of type attributes needs special\n\
2052 handling. If defined, the result is a list of the combined\n\
2053 @code{TYPE_ATTRIBUTES} of @var{type1} and @var{type2}. It is assumed\n\
2054 that @code{comptypes} has already been called and returned 1. This\n\
2055 function may call @code{merge_attributes} to handle machine-independent\n\
2056 merging.",
2057 tree, (tree type1, tree type2),
2058 merge_type_attributes)
2060 /* Table of machine attributes and functions to handle them.
2061 Ignored if NULL. */
2062 DEFHOOKPOD
2063 (attribute_table,
2064 "If defined, this target hook points to an array of @samp{struct\n\
2065 attribute_spec} (defined in @file{tree-core.h}) specifying the machine\n\
2066 specific attributes for this target and some of the restrictions on the\n\
2067 entities to which these attributes are applied and the arguments they\n\
2068 take.",
2069 const struct attribute_spec *, NULL)
2071 /* Return true iff attribute NAME expects a plain identifier as its first
2072 argument. */
2073 DEFHOOK
2074 (attribute_takes_identifier_p,
2075 "If defined, this target hook is a function which returns true if the\n\
2076 machine-specific attribute named @var{name} expects an identifier\n\
2077 given as its first argument to be passed on as a plain identifier, not\n\
2078 subjected to name lookup. If this is not defined, the default is\n\
2079 false for all machine-specific attributes.",
2080 bool, (const_tree name),
2081 hook_bool_const_tree_false)
2083 /* Return zero if the attributes on TYPE1 and TYPE2 are incompatible,
2084 one if they are compatible and two if they are nearly compatible
2085 (which causes a warning to be generated). */
2086 DEFHOOK
2087 (comp_type_attributes,
2088 "If defined, this target hook is a function which returns zero if the attributes on\n\
2089 @var{type1} and @var{type2} are incompatible, one if they are compatible,\n\
2090 and two if they are nearly compatible (which causes a warning to be\n\
2091 generated). If this is not defined, machine-specific attributes are\n\
2092 supposed always to be compatible.",
2093 int, (const_tree type1, const_tree type2),
2094 hook_int_const_tree_const_tree_1)
2096 /* Assign default attributes to the newly defined TYPE. */
2097 DEFHOOK
2098 (set_default_type_attributes,
2099 "If defined, this target hook is a function which assigns default attributes to\n\
2100 the newly defined @var{type}.",
2101 void, (tree type),
2102 hook_void_tree)
2104 /* Insert attributes on the newly created DECL. */
2105 DEFHOOK
2106 (insert_attributes,
2107 "Define this target hook if you want to be able to add attributes to a decl\n\
2108 when it is being created. This is normally useful for back ends which\n\
2109 wish to implement a pragma by using the attributes which correspond to\n\
2110 the pragma's effect. The @var{node} argument is the decl which is being\n\
2111 created. The @var{attr_ptr} argument is a pointer to the attribute list\n\
2112 for this decl. The list itself should not be modified, since it may be\n\
2113 shared with other decls, but attributes may be chained on the head of\n\
2114 the list and @code{*@var{attr_ptr}} modified to point to the new\n\
2115 attributes, or a copy of the list may be made if further changes are\n\
2116 needed.",
2117 void, (tree node, tree *attr_ptr),
2118 hook_void_tree_treeptr)
2120 /* Return true if FNDECL (which has at least one machine attribute)
2121 can be inlined despite its machine attributes, false otherwise. */
2122 DEFHOOK
2123 (function_attribute_inlinable_p,
2124 "@cindex inlining\n\
2125 This target hook returns @code{true} if it is OK to inline @var{fndecl}\n\
2126 into the current function, despite its having target-specific\n\
2127 attributes, @code{false} otherwise. By default, if a function has a\n\
2128 target specific attribute attached to it, it will not be inlined.",
2129 bool, (const_tree fndecl),
2130 hook_bool_const_tree_false)
2132 /* Return true if bitfields in RECORD_TYPE should follow the
2133 Microsoft Visual C++ bitfield layout rules. */
2134 DEFHOOK
2135 (ms_bitfield_layout_p,
2136 "This target hook returns @code{true} if bit-fields in the given\n\
2137 @var{record_type} are to be laid out following the rules of Microsoft\n\
2138 Visual C/C++, namely: (i) a bit-field won't share the same storage\n\
2139 unit with the previous bit-field if their underlying types have\n\
2140 different sizes, and the bit-field will be aligned to the highest\n\
2141 alignment of the underlying types of itself and of the previous\n\
2142 bit-field; (ii) a zero-sized bit-field will affect the alignment of\n\
2143 the whole enclosing structure, even if it is unnamed; except that\n\
2144 (iii) a zero-sized bit-field will be disregarded unless it follows\n\
2145 another bit-field of nonzero size. If this hook returns @code{true},\n\
2146 other macros that control bit-field layout are ignored.\n\
2148 When a bit-field is inserted into a packed record, the whole size\n\
2149 of the underlying type is used by one or more same-size adjacent\n\
2150 bit-fields (that is, if its long:3, 32 bits is used in the record,\n\
2151 and any additional adjacent long bit-fields are packed into the same\n\
2152 chunk of 32 bits. However, if the size changes, a new field of that\n\
2153 size is allocated). In an unpacked record, this is the same as using\n\
2154 alignment, but not equivalent when packing.\n\
2156 If both MS bit-fields and @samp{__attribute__((packed))} are used,\n\
2157 the latter will take precedence. If @samp{__attribute__((packed))} is\n\
2158 used on a single field when MS bit-fields are in use, it will take\n\
2159 precedence for that field, but the alignment of the rest of the structure\n\
2160 may affect its placement.",
2161 bool, (const_tree record_type),
2162 hook_bool_const_tree_false)
2164 /* For now this is only an interface to WORDS_BIG_ENDIAN for
2165 target-independent code like the front ends, need performance testing
2166 before switching completely to the target hook. */
2167 DEFHOOK_UNDOC
2168 (words_big_endian,
2170 bool, (void),
2171 targhook_words_big_endian)
2173 /* Likewise for FLOAT_WORDS_BIG_ENDIAN. */
2174 DEFHOOK_UNDOC
2175 (float_words_big_endian,
2177 bool, (void),
2178 targhook_float_words_big_endian)
2180 DEFHOOK
2181 (float_exceptions_rounding_supported_p,
2182 "Returns true if the target supports IEEE 754 floating-point exceptions\
2183 and rounding modes, false otherwise. This is intended to relate to the\
2184 @code{float} and @code{double} types, but not necessarily @code{long double}.\
2185 By default, returns true if the @code{adddf3} instruction pattern is\
2186 available and false otherwise, on the assumption that hardware floating\
2187 point supports exceptions and rounding modes but software floating point\
2188 does not.",
2189 bool, (void),
2190 default_float_exceptions_rounding_supported_p)
2192 /* True if the target supports decimal floating point. */
2193 DEFHOOK
2194 (decimal_float_supported_p,
2195 "Returns true if the target supports decimal floating point.",
2196 bool, (void),
2197 default_decimal_float_supported_p)
2199 /* True if the target supports fixed-point. */
2200 DEFHOOK
2201 (fixed_point_supported_p,
2202 "Returns true if the target supports fixed-point arithmetic.",
2203 bool, (void),
2204 default_fixed_point_supported_p)
2206 /* Return true if anonymous bitfields affect structure alignment. */
2207 DEFHOOK
2208 (align_anon_bitfield,
2209 "When @code{PCC_BITFIELD_TYPE_MATTERS} is true this hook will determine\n\
2210 whether unnamed bitfields affect the alignment of the containing\n\
2211 structure. The hook should return true if the structure should inherit\n\
2212 the alignment requirements of an unnamed bitfield's type.",
2213 bool, (void),
2214 hook_bool_void_false)
2216 /* Return true if volatile bitfields should use the narrowest type possible.
2217 Return false if they should use the container type. */
2218 DEFHOOK
2219 (narrow_volatile_bitfield,
2220 "This target hook should return @code{true} if accesses to volatile bitfields\n\
2221 should use the narrowest mode possible. It should return @code{false} if\n\
2222 these accesses should use the bitfield container type.\n\
2224 The default is @code{false}.",
2225 bool, (void),
2226 hook_bool_void_false)
2228 /* Set up target-specific built-in functions. */
2229 DEFHOOK
2230 (init_builtins,
2231 "Define this hook if you have any machine-specific built-in functions\n\
2232 that need to be defined. It should be a function that performs the\n\
2233 necessary setup.\n\
2235 Machine specific built-in functions can be useful to expand special machine\n\
2236 instructions that would otherwise not normally be generated because\n\
2237 they have no equivalent in the source language (for example, SIMD vector\n\
2238 instructions or prefetch instructions).\n\
2240 To create a built-in function, call the function\n\
2241 @code{lang_hooks.builtin_function}\n\
2242 which is defined by the language front end. You can use any type nodes set\n\
2243 up by @code{build_common_tree_nodes};\n\
2244 only language front ends that use those two functions will call\n\
2245 @samp{TARGET_INIT_BUILTINS}.",
2246 void, (void),
2247 hook_void_void)
2249 /* Initialize (if INITIALIZE_P is true) and return the target-specific
2250 built-in function decl for CODE.
2251 Return NULL if that is not possible. Return error_mark_node if CODE
2252 is outside of the range of valid target builtin function codes. */
2253 DEFHOOK
2254 (builtin_decl,
2255 "Define this hook if you have any machine-specific built-in functions\n\
2256 that need to be defined. It should be a function that returns the\n\
2257 builtin function declaration for the builtin function code @var{code}.\n\
2258 If there is no such builtin and it cannot be initialized at this time\n\
2259 if @var{initialize_p} is true the function should return @code{NULL_TREE}.\n\
2260 If @var{code} is out of range the function should return\n\
2261 @code{error_mark_node}.",
2262 tree, (unsigned code, bool initialize_p), NULL)
2264 /* Expand a target-specific builtin. */
2265 DEFHOOK
2266 (expand_builtin,
2267 "\n\
2268 Expand a call to a machine specific built-in function that was set up by\n\
2269 @samp{TARGET_INIT_BUILTINS}. @var{exp} is the expression for the\n\
2270 function call; the result should go to @var{target} if that is\n\
2271 convenient, and have mode @var{mode} if that is convenient.\n\
2272 @var{subtarget} may be used as the target for computing one of\n\
2273 @var{exp}'s operands. @var{ignore} is nonzero if the value is to be\n\
2274 ignored. This function should return the result of the call to the\n\
2275 built-in function.",
2276 rtx,
2277 (tree exp, rtx target, rtx subtarget, machine_mode mode, int ignore),
2278 default_expand_builtin)
2280 DEFHOOK
2281 (builtin_chkp_function,
2282 "This hook allows target to redefine built-in functions used by\n\
2283 Pointer Bounds Checker for code instrumentation. Hook should return\n\
2284 fndecl of function implementing generic builtin whose code is\n\
2285 passed in @var{fcode}. Currently following built-in functions are\n\
2286 obtained using this hook:\n\
2287 @deftypefn {Built-in Function} __bounds_type __chkp_bndmk (const void *@var{lb}, size_t @var{size})\n\
2288 Function code - BUILT_IN_CHKP_BNDMK. This built-in function is used\n\
2289 by Pointer Bounds Checker to create bound values. @var{lb} holds low\n\
2290 bound of the resulting bounds. @var{size} holds size of created bounds.\n\
2291 @end deftypefn\n\
2293 @deftypefn {Built-in Function} void __chkp_bndstx (const void *@var{ptr}, __bounds_type @var{b}, const void **@var{loc})\n\
2294 Function code - @code{BUILT_IN_CHKP_BNDSTX}. This built-in function is used\n\
2295 by Pointer Bounds Checker to store bounds @var{b} for pointer @var{ptr}\n\
2296 when @var{ptr} is stored by address @var{loc}.\n\
2297 @end deftypefn\n\
2299 @deftypefn {Built-in Function} __bounds_type __chkp_bndldx (const void **@var{loc}, const void *@var{ptr})\n\
2300 Function code - @code{BUILT_IN_CHKP_BNDLDX}. This built-in function is used\n\
2301 by Pointer Bounds Checker to get bounds of pointer @var{ptr} loaded by\n\
2302 address @var{loc}.\n\
2303 @end deftypefn\n\
2305 @deftypefn {Built-in Function} void __chkp_bndcl (const void *@var{ptr}, __bounds_type @var{b})\n\
2306 Function code - @code{BUILT_IN_CHKP_BNDCL}. This built-in function is used\n\
2307 by Pointer Bounds Checker to perform check for pointer @var{ptr} against\n\
2308 lower bound of bounds @var{b}.\n\
2309 @end deftypefn\n\
2311 @deftypefn {Built-in Function} void __chkp_bndcu (const void *@var{ptr}, __bounds_type @var{b})\n\
2312 Function code - @code{BUILT_IN_CHKP_BNDCU}. This built-in function is used\n\
2313 by Pointer Bounds Checker to perform check for pointer @var{ptr} against\n\
2314 upper bound of bounds @var{b}.\n\
2315 @end deftypefn\n\
2317 @deftypefn {Built-in Function} __bounds_type __chkp_bndret (void *@var{ptr})\n\
2318 Function code - @code{BUILT_IN_CHKP_BNDRET}. This built-in function is used\n\
2319 by Pointer Bounds Checker to obtain bounds returned by a call statement.\n\
2320 @var{ptr} passed to built-in is @code{SSA_NAME} returned by the call.\n\
2321 @end deftypefn\n\
2323 @deftypefn {Built-in Function} __bounds_type __chkp_intersect (__bounds_type @var{b1}, __bounds_type @var{b2})\n\
2324 Function code - @code{BUILT_IN_CHKP_INTERSECT}. This built-in function\n\
2325 returns intersection of bounds @var{b1} and @var{b2}.\n\
2326 @end deftypefn\n\
2328 @deftypefn {Built-in Function} __bounds_type __chkp_narrow (const void *@var{ptr}, __bounds_type @var{b}, size_t @var{s})\n\
2329 Function code - @code{BUILT_IN_CHKP_NARROW}. This built-in function\n\
2330 returns intersection of bounds @var{b} and\n\
2331 [@var{ptr}, @var{ptr} + @var{s} - @code{1}].\n\
2332 @end deftypefn\n\
2334 @deftypefn {Built-in Function} size_t __chkp_sizeof (const void *@var{ptr})\n\
2335 Function code - @code{BUILT_IN_CHKP_SIZEOF}. This built-in function\n\
2336 returns size of object referenced by @var{ptr}. @var{ptr} is always\n\
2337 @code{ADDR_EXPR} of @code{VAR_DECL}. This built-in is used by\n\
2338 Pointer Bounds Checker when bounds of object cannot be computed statically\n\
2339 (e.g. object has incomplete type).\n\
2340 @end deftypefn\n\
2342 @deftypefn {Built-in Function} const void *__chkp_extract_lower (__bounds_type @var{b})\n\
2343 Function code - @code{BUILT_IN_CHKP_EXTRACT_LOWER}. This built-in function\n\
2344 returns lower bound of bounds @var{b}.\n\
2345 @end deftypefn\n\
2347 @deftypefn {Built-in Function} const void *__chkp_extract_upper (__bounds_type @var{b})\n\
2348 Function code - @code{BUILT_IN_CHKP_EXTRACT_UPPER}. This built-in function\n\
2349 returns upper bound of bounds @var{b}.\n\
2350 @end deftypefn",
2351 tree, (unsigned fcode),
2352 default_builtin_chkp_function)
2354 DEFHOOK
2355 (chkp_bound_type,
2356 "Return type to be used for bounds",
2357 tree, (void),
2358 default_chkp_bound_type)
2360 DEFHOOK
2361 (chkp_bound_mode,
2362 "Return mode to be used for bounds.",
2363 enum machine_mode, (void),
2364 default_chkp_bound_mode)
2366 DEFHOOK
2367 (chkp_make_bounds_constant,
2368 "Return constant used to statically initialize constant bounds\n\
2369 with specified lower bound @var{lb} and upper bounds @var{ub}.",
2370 tree, (HOST_WIDE_INT lb, HOST_WIDE_INT ub),
2371 default_chkp_make_bounds_constant)
2373 DEFHOOK
2374 (chkp_initialize_bounds,
2375 "Generate a list of statements @var{stmts} to initialize pointer\n\
2376 bounds variable @var{var} with bounds @var{lb} and @var{ub}. Return\n\
2377 the number of generated statements.",
2378 int, (tree var, tree lb, tree ub, tree *stmts),
2379 default_chkp_initialize_bounds)
2381 /* Select a replacement for a target-specific builtin. This is done
2382 *before* regular type checking, and so allows the target to
2383 implement a crude form of function overloading. The result is a
2384 complete expression that implements the operation. PARAMS really
2385 has type VEC(tree,gc)*, but we don't want to include tree.h here. */
2386 DEFHOOK
2387 (resolve_overloaded_builtin,
2388 "Select a replacement for a machine specific built-in function that\n\
2389 was set up by @samp{TARGET_INIT_BUILTINS}. This is done\n\
2390 @emph{before} regular type checking, and so allows the target to\n\
2391 implement a crude form of function overloading. @var{fndecl} is the\n\
2392 declaration of the built-in function. @var{arglist} is the list of\n\
2393 arguments passed to the built-in function. The result is a\n\
2394 complete expression that implements the operation, usually\n\
2395 another @code{CALL_EXPR}.\n\
2396 @var{arglist} really has type @samp{VEC(tree,gc)*}",
2397 tree, (unsigned int /*location_t*/ loc, tree fndecl, void *arglist), NULL)
2399 /* Fold a target-specific builtin to a tree valid for both GIMPLE
2400 and GENERIC. */
2401 DEFHOOK
2402 (fold_builtin,
2403 "Fold a call to a machine specific built-in function that was set up by\n\
2404 @samp{TARGET_INIT_BUILTINS}. @var{fndecl} is the declaration of the\n\
2405 built-in function. @var{n_args} is the number of arguments passed to\n\
2406 the function; the arguments themselves are pointed to by @var{argp}.\n\
2407 The result is another tree, valid for both GIMPLE and GENERIC,\n\
2408 containing a simplified expression for the call's result. If\n\
2409 @var{ignore} is true the value will be ignored.",
2410 tree, (tree fndecl, int n_args, tree *argp, bool ignore),
2411 hook_tree_tree_int_treep_bool_null)
2413 /* Fold a target-specific builtin to a valid GIMPLE tree. */
2414 DEFHOOK
2415 (gimple_fold_builtin,
2416 "Fold a call to a machine specific built-in function that was set up\n\
2417 by @samp{TARGET_INIT_BUILTINS}. @var{gsi} points to the gimple\n\
2418 statement holding the function call. Returns true if any change\n\
2419 was made to the GIMPLE stream.",
2420 bool, (gimple_stmt_iterator *gsi),
2421 hook_bool_gsiptr_false)
2423 /* Target hook is used to compare the target attributes in two functions to
2424 determine which function's features get higher priority. This is used
2425 during function multi-versioning to figure out the order in which two
2426 versions must be dispatched. A function version with a higher priority
2427 is checked for dispatching earlier. DECL1 and DECL2 are
2428 the two function decls that will be compared. It returns positive value
2429 if DECL1 is higher priority, negative value if DECL2 is higher priority
2430 and 0 if they are the same. */
2431 DEFHOOK
2432 (compare_version_priority,
2433 "This hook is used to compare the target attributes in two functions to\n\
2434 determine which function's features get higher priority. This is used\n\
2435 during function multi-versioning to figure out the order in which two\n\
2436 versions must be dispatched. A function version with a higher priority\n\
2437 is checked for dispatching earlier. @var{decl1} and @var{decl2} are\n\
2438 the two function decls that will be compared.",
2439 int, (tree decl1, tree decl2), NULL)
2441 /* Target hook is used to generate the dispatcher logic to invoke the right
2442 function version at run-time for a given set of function versions.
2443 ARG points to the callgraph node of the dispatcher function whose body
2444 must be generated. */
2445 DEFHOOK
2446 (generate_version_dispatcher_body,
2447 "This hook is used to generate the dispatcher logic to invoke the right\n\
2448 function version at run-time for a given set of function versions.\n\
2449 @var{arg} points to the callgraph node of the dispatcher function whose\n\
2450 body must be generated.",
2451 tree, (void *arg), NULL)
2453 /* Target hook is used to get the dispatcher function for a set of function
2454 versions. The dispatcher function is called to invoke the right function
2455 version at run-time. DECL is one version from a set of semantically
2456 identical versions. */
2457 DEFHOOK
2458 (get_function_versions_dispatcher,
2459 "This hook is used to get the dispatcher function for a set of function\n\
2460 versions. The dispatcher function is called to invoke the right function\n\
2461 version at run-time. @var{decl} is one version from a set of semantically\n\
2462 identical versions.",
2463 tree, (void *decl), NULL)
2465 /* Returns a code for a target-specific builtin that implements
2466 reciprocal of a target-specific function, or NULL_TREE if not available. */
2467 DEFHOOK
2468 (builtin_reciprocal,
2469 "This hook should return the DECL of a function that implements the\n\
2470 reciprocal of the machine-specific builtin function @var{fndecl}, or\n\
2471 @code{NULL_TREE} if such a function is not available.",
2472 tree, (tree fndecl),
2473 default_builtin_reciprocal)
2475 /* For a vendor-specific TYPE, return a pointer to a statically-allocated
2476 string containing the C++ mangling for TYPE. In all other cases, return
2477 NULL. */
2478 DEFHOOK
2479 (mangle_type,
2480 "If your target defines any fundamental types, or any types your target\n\
2481 uses should be mangled differently from the default, define this hook\n\
2482 to return the appropriate encoding for these types as part of a C++\n\
2483 mangled name. The @var{type} argument is the tree structure representing\n\
2484 the type to be mangled. The hook may be applied to trees which are\n\
2485 not target-specific fundamental types; it should return @code{NULL}\n\
2486 for all such types, as well as arguments it does not recognize. If the\n\
2487 return value is not @code{NULL}, it must point to a statically-allocated\n\
2488 string constant.\n\
2490 Target-specific fundamental types might be new fundamental types or\n\
2491 qualified versions of ordinary fundamental types. Encode new\n\
2492 fundamental types as @samp{@w{u @var{n} @var{name}}}, where @var{name}\n\
2493 is the name used for the type in source code, and @var{n} is the\n\
2494 length of @var{name} in decimal. Encode qualified versions of\n\
2495 ordinary types as @samp{@w{U @var{n} @var{name} @var{code}}}, where\n\
2496 @var{name} is the name used for the type qualifier in source code,\n\
2497 @var{n} is the length of @var{name} as above, and @var{code} is the\n\
2498 code used to represent the unqualified version of this type. (See\n\
2499 @code{write_builtin_type} in @file{cp/mangle.c} for the list of\n\
2500 codes.) In both cases the spaces are for clarity; do not include any\n\
2501 spaces in your string.\n\
2503 This hook is applied to types prior to typedef resolution. If the mangled\n\
2504 name for a particular type depends only on that type's main variant, you\n\
2505 can perform typedef resolution yourself using @code{TYPE_MAIN_VARIANT}\n\
2506 before mangling.\n\
2508 The default version of this hook always returns @code{NULL}, which is\n\
2509 appropriate for a target that does not define any new fundamental\n\
2510 types.",
2511 const char *, (const_tree type),
2512 hook_constcharptr_const_tree_null)
2514 /* Make any adjustments to libfunc names needed for this target. */
2515 DEFHOOK
2516 (init_libfuncs,
2517 "This hook should declare additional library routines or rename\n\
2518 existing ones, using the functions @code{set_optab_libfunc} and\n\
2519 @code{init_one_libfunc} defined in @file{optabs.c}.\n\
2520 @code{init_optabs} calls this macro after initializing all the normal\n\
2521 library routines.\n\
2523 The default is to do nothing. Most ports don't need to define this hook.",
2524 void, (void),
2525 hook_void_void)
2527 /* Add a __gnu_ prefix to library functions rather than just __. */
2528 DEFHOOKPOD
2529 (libfunc_gnu_prefix,
2530 "If false (the default), internal library routines start with two\n\
2531 underscores. If set to true, these routines start with @code{__gnu_}\n\
2532 instead. E.g., @code{__muldi3} changes to @code{__gnu_muldi3}. This\n\
2533 currently only affects functions defined in @file{libgcc2.c}. If this\n\
2534 is set to true, the @file{tm.h} file must also\n\
2535 @code{#define LIBGCC2_GNU_PREFIX}.",
2536 bool, false)
2538 /* Given a decl, a section name, and whether the decl initializer
2539 has relocs, choose attributes for the section. */
2540 /* ??? Should be merged with SELECT_SECTION and UNIQUE_SECTION. */
2541 DEFHOOK
2542 (section_type_flags,
2543 "Choose a set of section attributes for use by @code{TARGET_ASM_NAMED_SECTION}\n\
2544 based on a variable or function decl, a section name, and whether or not the\n\
2545 declaration's initializer may contain runtime relocations. @var{decl} may be\n\
2546 null, in which case read-write data should be assumed.\n\
2548 The default version of this function handles choosing code vs data,\n\
2549 read-only vs read-write data, and @code{flag_pic}. You should only\n\
2550 need to override this if your target has special flags that might be\n\
2551 set via @code{__attribute__}.",
2552 unsigned int, (tree decl, const char *name, int reloc),
2553 default_section_type_flags)
2555 DEFHOOK
2556 (libc_has_function,
2557 "This hook determines whether a function from a class of functions\n\
2558 @var{fn_class} is present at the runtime.",
2559 bool, (enum function_class fn_class),
2560 default_libc_has_function)
2562 /* True if new jumps cannot be created, to replace existing ones or
2563 not, at the current point in the compilation. */
2564 DEFHOOK
2565 (cannot_modify_jumps_p,
2566 "This target hook returns @code{true} past the point in which new jump\n\
2567 instructions could be created. On machines that require a register for\n\
2568 every jump such as the SHmedia ISA of SH5, this point would typically be\n\
2569 reload, so this target hook should be defined to a function such as:\n\
2571 @smallexample\n\
2572 static bool\n\
2573 cannot_modify_jumps_past_reload_p ()\n\
2574 @{\n\
2575 return (reload_completed || reload_in_progress);\n\
2576 @}\n\
2577 @end smallexample",
2578 bool, (void),
2579 hook_bool_void_false)
2581 /* True if FOLLOWER may be modified to follow FOLLOWEE. */
2582 DEFHOOK
2583 (can_follow_jump,
2584 "FOLLOWER and FOLLOWEE are JUMP_INSN instructions;\
2585 return true if FOLLOWER may be modified to follow FOLLOWEE;\
2586 false, if it can't.\
2587 For example, on some targets, certain kinds of branches can't be made to\
2588 follow through a hot/cold partitioning.",
2589 bool, (const rtx_insn *follower, const rtx_insn *followee),
2590 hook_bool_const_rtx_insn_const_rtx_insn_true)
2592 /* Return a register class for which branch target register
2593 optimizations should be applied. */
2594 DEFHOOK
2595 (branch_target_register_class,
2596 "This target hook returns a register class for which branch target register\n\
2597 optimizations should be applied. All registers in this class should be\n\
2598 usable interchangeably. After reload, registers in this class will be\n\
2599 re-allocated and loads will be hoisted out of loops and be subjected\n\
2600 to inter-block scheduling.",
2601 reg_class_t, (void),
2602 default_branch_target_register_class)
2604 /* Return true if branch target register optimizations should include
2605 callee-saved registers that are not already live during the current
2606 function. AFTER_PE_GEN is true if prologues and epilogues have
2607 already been generated. */
2608 DEFHOOK
2609 (branch_target_register_callee_saved,
2610 "Branch target register optimization will by default exclude callee-saved\n\
2611 registers\n\
2612 that are not already live during the current function; if this target hook\n\
2613 returns true, they will be included. The target code must than make sure\n\
2614 that all target registers in the class returned by\n\
2615 @samp{TARGET_BRANCH_TARGET_REGISTER_CLASS} that might need saving are\n\
2616 saved. @var{after_prologue_epilogue_gen} indicates if prologues and\n\
2617 epilogues have already been generated. Note, even if you only return\n\
2618 true when @var{after_prologue_epilogue_gen} is false, you still are likely\n\
2619 to have to make special provisions in @code{INITIAL_ELIMINATION_OFFSET}\n\
2620 to reserve space for caller-saved target registers.",
2621 bool, (bool after_prologue_epilogue_gen),
2622 hook_bool_bool_false)
2624 /* Return true if the target supports conditional execution. */
2625 DEFHOOK
2626 (have_conditional_execution,
2627 "This target hook returns true if the target supports conditional execution.\n\
2628 This target hook is required only when the target has several different\n\
2629 modes and they have different conditional execution capability, such as ARM.",
2630 bool, (void),
2631 default_have_conditional_execution)
2633 DEFHOOK
2634 (gen_ccmp_first,
2635 "This function prepares to emit a comparison insn for the first compare in a\n\
2636 sequence of conditional comparisions. It returns an appropriate comparison\n\
2637 with @code{CC} for passing to @code{gen_ccmp_next} or @code{cbranch_optab}.\n\
2638 The insns to prepare the compare are saved in @var{prep_seq} and the compare\n\
2639 insns are saved in @var{gen_seq}. They will be emitted when all the\n\
2640 compares in the the conditional comparision are generated without error.\n\
2641 @var{code} is the @code{rtx_code} of the compare for @var{op0} and @var{op1}.",
2642 rtx, (rtx_insn **prep_seq, rtx_insn **gen_seq, int code, tree op0, tree op1),
2643 NULL)
2645 DEFHOOK
2646 (gen_ccmp_next,
2647 "This function prepares to emit a conditional comparison within a sequence\n\
2648 of conditional comparisons. It returns an appropriate comparison with\n\
2649 @code{CC} for passing to @code{gen_ccmp_next} or @code{cbranch_optab}.\n\
2650 The insns to prepare the compare are saved in @var{prep_seq} and the compare\n\
2651 insns are saved in @var{gen_seq}. They will be emitted when all the\n\
2652 compares in the conditional comparision are generated without error. The\n\
2653 @var{prev} expression is the result of a prior call to @code{gen_ccmp_first}\n\
2654 or @code{gen_ccmp_next}. It may return @code{NULL} if the combination of\n\
2655 @var{prev} and this comparison is not supported, otherwise the result must\n\
2656 be appropriate for passing to @code{gen_ccmp_next} or @code{cbranch_optab}.\n\
2657 @var{code} is the @code{rtx_code} of the compare for @var{op0} and @var{op1}.\n\
2658 @var{bit_code} is @code{AND} or @code{IOR}, which is the op on the compares.",
2659 rtx, (rtx_insn **prep_seq, rtx_insn **gen_seq, rtx prev, int cmp_code, tree op0, tree op1, int bit_code),
2660 NULL)
2662 /* Return a new value for loop unroll size. */
2663 DEFHOOK
2664 (loop_unroll_adjust,
2665 "This target hook returns a new value for the number of times @var{loop}\n\
2666 should be unrolled. The parameter @var{nunroll} is the number of times\n\
2667 the loop is to be unrolled. The parameter @var{loop} is a pointer to\n\
2668 the loop, which is going to be checked for unrolling. This target hook\n\
2669 is required only when the target has special constraints like maximum\n\
2670 number of memory accesses.",
2671 unsigned, (unsigned nunroll, struct loop *loop),
2672 NULL)
2674 /* True if X is a legitimate MODE-mode immediate operand. */
2675 DEFHOOK
2676 (legitimate_constant_p,
2677 "This hook returns true if @var{x} is a legitimate constant for a\n\
2678 @var{mode}-mode immediate operand on the target machine. You can assume that\n\
2679 @var{x} satisfies @code{CONSTANT_P}, so you need not check this.\n\
2681 The default definition returns true.",
2682 bool, (machine_mode mode, rtx x),
2683 hook_bool_mode_rtx_true)
2685 /* True if the constant X cannot be placed in the constant pool. */
2686 DEFHOOK
2687 (cannot_force_const_mem,
2688 "This hook should return true if @var{x} is of a form that cannot (or\n\
2689 should not) be spilled to the constant pool. @var{mode} is the mode\n\
2690 of @var{x}.\n\
2692 The default version of this hook returns false.\n\
2694 The primary reason to define this hook is to prevent reload from\n\
2695 deciding that a non-legitimate constant would be better reloaded\n\
2696 from the constant pool instead of spilling and reloading a register\n\
2697 holding the constant. This restriction is often true of addresses\n\
2698 of TLS symbols for various targets.",
2699 bool, (machine_mode mode, rtx x),
2700 hook_bool_mode_rtx_false)
2702 DEFHOOK_UNDOC
2703 (cannot_copy_insn_p,
2704 "True if the insn @var{x} cannot be duplicated.",
2705 bool, (rtx_insn *), NULL)
2707 /* True if X is considered to be commutative. */
2708 DEFHOOK
2709 (commutative_p,
2710 "This target hook returns @code{true} if @var{x} is considered to be commutative.\n\
2711 Usually, this is just COMMUTATIVE_P (@var{x}), but the HP PA doesn't consider\n\
2712 PLUS to be commutative inside a MEM@. @var{outer_code} is the rtx code\n\
2713 of the enclosing rtl, if known, otherwise it is UNKNOWN.",
2714 bool, (const_rtx x, int outer_code),
2715 hook_bool_const_rtx_commutative_p)
2717 /* True if ADDR is an address-expression whose effect depends
2718 on the mode of the memory reference it is used in. */
2719 DEFHOOK
2720 (mode_dependent_address_p,
2721 "This hook returns @code{true} if memory address @var{addr} in address\n\
2722 space @var{addrspace} can have\n\
2723 different meanings depending on the machine mode of the memory\n\
2724 reference it is used for or if the address is valid for some modes\n\
2725 but not others.\n\
2727 Autoincrement and autodecrement addresses typically have mode-dependent\n\
2728 effects because the amount of the increment or decrement is the size\n\
2729 of the operand being addressed. Some machines have other mode-dependent\n\
2730 addresses. Many RISC machines have no mode-dependent addresses.\n\
2732 You may assume that @var{addr} is a valid address for the machine.\n\
2734 The default version of this hook returns @code{false}.",
2735 bool, (const_rtx addr, addr_space_t addrspace),
2736 default_mode_dependent_address_p)
2738 /* Given an invalid address X for a given machine mode, try machine-specific
2739 ways to make it legitimate. Return X or an invalid address on failure. */
2740 DEFHOOK
2741 (legitimize_address,
2742 "This hook is given an invalid memory address @var{x} for an\n\
2743 operand of mode @var{mode} and should try to return a valid memory\n\
2744 address.\n\
2746 @findex break_out_memory_refs\n\
2747 @var{x} will always be the result of a call to @code{break_out_memory_refs},\n\
2748 and @var{oldx} will be the operand that was given to that function to produce\n\
2749 @var{x}.\n\
2751 The code of the hook should not alter the substructure of\n\
2752 @var{x}. If it transforms @var{x} into a more legitimate form, it\n\
2753 should return the new @var{x}.\n\
2755 It is not necessary for this hook to come up with a legitimate address,\n\
2756 with the exception of native TLS addresses (@pxref{Emulated TLS}).\n\
2757 The compiler has standard ways of doing so in all cases. In fact, if\n\
2758 the target supports only emulated TLS, it\n\
2759 is safe to omit this hook or make it return @var{x} if it cannot find\n\
2760 a valid way to legitimize the address. But often a machine-dependent\n\
2761 strategy can generate better code.",
2762 rtx, (rtx x, rtx oldx, machine_mode mode),
2763 default_legitimize_address)
2765 /* Given an address RTX, undo the effects of LEGITIMIZE_ADDRESS. */
2766 DEFHOOK
2767 (delegitimize_address,
2768 "This hook is used to undo the possibly obfuscating effects of the\n\
2769 @code{LEGITIMIZE_ADDRESS} and @code{LEGITIMIZE_RELOAD_ADDRESS} target\n\
2770 macros. Some backend implementations of these macros wrap symbol\n\
2771 references inside an @code{UNSPEC} rtx to represent PIC or similar\n\
2772 addressing modes. This target hook allows GCC's optimizers to understand\n\
2773 the semantics of these opaque @code{UNSPEC}s by converting them back\n\
2774 into their original form.",
2775 rtx, (rtx x),
2776 delegitimize_mem_from_attrs)
2778 /* Given an RTX, return true if it is not ok to emit it into debug info
2779 section. */
2780 DEFHOOK
2781 (const_not_ok_for_debug_p,
2782 "This hook should return true if @var{x} should not be emitted into\n\
2783 debug sections.",
2784 bool, (rtx x),
2785 hook_bool_rtx_false)
2787 /* Given an address RTX, say whether it is valid. */
2788 DEFHOOK
2789 (legitimate_address_p,
2790 "A function that returns whether @var{x} (an RTX) is a legitimate memory\n\
2791 address on the target machine for a memory operand of mode @var{mode}.\n\
2793 Legitimate addresses are defined in two variants: a strict variant and a\n\
2794 non-strict one. The @var{strict} parameter chooses which variant is\n\
2795 desired by the caller.\n\
2797 The strict variant is used in the reload pass. It must be defined so\n\
2798 that any pseudo-register that has not been allocated a hard register is\n\
2799 considered a memory reference. This is because in contexts where some\n\
2800 kind of register is required, a pseudo-register with no hard register\n\
2801 must be rejected. For non-hard registers, the strict variant should look\n\
2802 up the @code{reg_renumber} array; it should then proceed using the hard\n\
2803 register number in the array, or treat the pseudo as a memory reference\n\
2804 if the array holds @code{-1}.\n\
2806 The non-strict variant is used in other passes. It must be defined to\n\
2807 accept all pseudo-registers in every context where some kind of\n\
2808 register is required.\n\
2810 Normally, constant addresses which are the sum of a @code{symbol_ref}\n\
2811 and an integer are stored inside a @code{const} RTX to mark them as\n\
2812 constant. Therefore, there is no need to recognize such sums\n\
2813 specifically as legitimate addresses. Normally you would simply\n\
2814 recognize any @code{const} as legitimate.\n\
2816 Usually @code{PRINT_OPERAND_ADDRESS} is not prepared to handle constant\n\
2817 sums that are not marked with @code{const}. It assumes that a naked\n\
2818 @code{plus} indicates indexing. If so, then you @emph{must} reject such\n\
2819 naked constant sums as illegitimate addresses, so that none of them will\n\
2820 be given to @code{PRINT_OPERAND_ADDRESS}.\n\
2822 @cindex @code{TARGET_ENCODE_SECTION_INFO} and address validation\n\
2823 On some machines, whether a symbolic address is legitimate depends on\n\
2824 the section that the address refers to. On these machines, define the\n\
2825 target hook @code{TARGET_ENCODE_SECTION_INFO} to store the information\n\
2826 into the @code{symbol_ref}, and then check for it here. When you see a\n\
2827 @code{const}, you will have to look inside it to find the\n\
2828 @code{symbol_ref} in order to determine the section. @xref{Assembler\n\
2829 Format}.\n\
2831 @cindex @code{GO_IF_LEGITIMATE_ADDRESS}\n\
2832 Some ports are still using a deprecated legacy substitute for\n\
2833 this hook, the @code{GO_IF_LEGITIMATE_ADDRESS} macro. This macro\n\
2834 has this syntax:\n\
2836 @example\n\
2837 #define GO_IF_LEGITIMATE_ADDRESS (@var{mode}, @var{x}, @var{label})\n\
2838 @end example\n\
2840 @noindent\n\
2841 and should @code{goto @var{label}} if the address @var{x} is a valid\n\
2842 address on the target machine for a memory operand of mode @var{mode}.\n\
2844 @findex REG_OK_STRICT\n\
2845 Compiler source files that want to use the strict variant of this\n\
2846 macro define the macro @code{REG_OK_STRICT}. You should use an\n\
2847 @code{#ifdef REG_OK_STRICT} conditional to define the strict variant in\n\
2848 that case and the non-strict variant otherwise.\n\
2850 Using the hook is usually simpler because it limits the number of\n\
2851 files that are recompiled when changes are made.",
2852 bool, (machine_mode mode, rtx x, bool strict),
2853 default_legitimate_address_p)
2855 /* True if the given constant can be put into an object_block. */
2856 DEFHOOK
2857 (use_blocks_for_constant_p,
2858 "This hook should return true if pool entries for constant @var{x} can\n\
2859 be placed in an @code{object_block} structure. @var{mode} is the mode\n\
2860 of @var{x}.\n\
2862 The default version returns false for all constants.",
2863 bool, (machine_mode mode, const_rtx x),
2864 hook_bool_mode_const_rtx_false)
2866 /* True if the given decl can be put into an object_block. */
2867 DEFHOOK
2868 (use_blocks_for_decl_p,
2869 "This hook should return true if pool entries for @var{decl} should\n\
2870 be placed in an @code{object_block} structure.\n\
2872 The default version returns true for all decls.",
2873 bool, (const_tree decl),
2874 hook_bool_const_tree_true)
2876 /* The minimum and maximum byte offsets for anchored addresses. */
2877 DEFHOOKPOD
2878 (min_anchor_offset,
2879 "The minimum offset that should be applied to a section anchor.\n\
2880 On most targets, it should be the smallest offset that can be\n\
2881 applied to a base register while still giving a legitimate address\n\
2882 for every mode. The default value is 0.",
2883 HOST_WIDE_INT, 0)
2885 DEFHOOKPOD
2886 (max_anchor_offset,
2887 "Like @code{TARGET_MIN_ANCHOR_OFFSET}, but the maximum (inclusive)\n\
2888 offset that should be applied to section anchors. The default\n\
2889 value is 0.",
2890 HOST_WIDE_INT, 0)
2892 /* True if section anchors can be used to access the given symbol. */
2893 DEFHOOK
2894 (use_anchors_for_symbol_p,
2895 "Return true if GCC should attempt to use anchors to access @code{SYMBOL_REF}\n\
2896 @var{x}. You can assume @samp{SYMBOL_REF_HAS_BLOCK_INFO_P (@var{x})} and\n\
2897 @samp{!SYMBOL_REF_ANCHOR_P (@var{x})}.\n\
2899 The default version is correct for most targets, but you might need to\n\
2900 intercept this hook to handle things like target-specific attributes\n\
2901 or target-specific sections.",
2902 bool, (const_rtx x),
2903 default_use_anchors_for_symbol_p)
2905 /* True if target supports indirect functions. */
2906 DEFHOOK
2907 (has_ifunc_p,
2908 "It returns true if the target supports GNU indirect functions.\n\
2909 The support includes the assembler, linker and dynamic linker.\n\
2910 The default value of this hook is based on target's libc.",
2911 bool, (void),
2912 default_has_ifunc_p)
2914 /* True if it is OK to do sibling call optimization for the specified
2915 call expression EXP. DECL will be the called function, or NULL if
2916 this is an indirect call. */
2917 DEFHOOK
2918 (function_ok_for_sibcall,
2919 "True if it is OK to do sibling call optimization for the specified\n\
2920 call expression @var{exp}. @var{decl} will be the called function,\n\
2921 or @code{NULL} if this is an indirect call.\n\
2923 It is not uncommon for limitations of calling conventions to prevent\n\
2924 tail calls to functions outside the current unit of translation, or\n\
2925 during PIC compilation. The hook is used to enforce these restrictions,\n\
2926 as the @code{sibcall} md pattern can not fail, or fall over to a\n\
2927 ``normal'' call. The criteria for successful sibling call optimization\n\
2928 may vary greatly between different architectures.",
2929 bool, (tree decl, tree exp),
2930 hook_bool_tree_tree_false)
2932 /* Establish appropriate back-end context for processing the function
2933 FNDECL. The argument might be NULL to indicate processing at top
2934 level, outside of any function scope. */
2935 DEFHOOK
2936 (set_current_function,
2937 "The compiler invokes this hook whenever it changes its current function\n\
2938 context (@code{cfun}). You can define this function if\n\
2939 the back end needs to perform any initialization or reset actions on a\n\
2940 per-function basis. For example, it may be used to implement function\n\
2941 attributes that affect register usage or code generation patterns.\n\
2942 The argument @var{decl} is the declaration for the new function context,\n\
2943 and may be null to indicate that the compiler has left a function context\n\
2944 and is returning to processing at the top level.\n\
2945 The default hook function does nothing.\n\
2947 GCC sets @code{cfun} to a dummy function context during initialization of\n\
2948 some parts of the back end. The hook function is not invoked in this\n\
2949 situation; you need not worry about the hook being invoked recursively,\n\
2950 or when the back end is in a partially-initialized state.\n\
2951 @code{cfun} might be @code{NULL} to indicate processing at top level,\n\
2952 outside of any function scope.",
2953 void, (tree decl), hook_void_tree)
2955 /* True if EXP should be placed in a "small data" section. */
2956 DEFHOOK
2957 (in_small_data_p,
2958 "Returns true if @var{exp} should be placed into a ``small data'' section.\n\
2959 The default version of this hook always returns false.",
2960 bool, (const_tree exp),
2961 hook_bool_const_tree_false)
2963 /* True if EXP names an object for which name resolution must resolve
2964 to the current executable or shared library. */
2965 DEFHOOK
2966 (binds_local_p,
2967 "Returns true if @var{exp} names an object for which name resolution\n\
2968 rules must resolve to the current ``module'' (dynamic shared library\n\
2969 or executable image).\n\
2971 The default version of this hook implements the name resolution rules\n\
2972 for ELF, which has a looser model of global name binding than other\n\
2973 currently supported object file formats.",
2974 bool, (const_tree exp),
2975 default_binds_local_p)
2977 /* Check if profiling code is before or after prologue. */
2978 DEFHOOK
2979 (profile_before_prologue,
2980 "It returns true if target wants profile code emitted before prologue.\n\n\
2981 The default version of this hook use the target macro\n\
2982 @code{PROFILE_BEFORE_PROLOGUE}.",
2983 bool, (void),
2984 default_profile_before_prologue)
2986 /* Return true if a leaf function should stay leaf even with profiling
2987 enabled. */
2988 DEFHOOK
2989 (keep_leaf_when_profiled,
2990 "This target hook returns true if the target wants the leaf flag for\
2991 the current function to stay true even if it calls mcount. This might\
2992 make sense for targets using the leaf flag only to determine whether a\
2993 stack frame needs to be generated or not and for which the call to\
2994 mcount is generated before the function prologue.",
2995 bool, (void),
2996 default_keep_leaf_when_profiled)
2998 /* Modify and return the identifier of a DECL's external name,
2999 originally identified by ID, as required by the target,
3000 (eg, append @nn to windows32 stdcall function names).
3001 The default is to return ID without modification. */
3002 DEFHOOK
3003 (mangle_decl_assembler_name,
3004 "Define this hook if you need to postprocess the assembler name generated\n\
3005 by target-independent code. The @var{id} provided to this hook will be\n\
3006 the computed name (e.g., the macro @code{DECL_NAME} of the @var{decl} in C,\n\
3007 or the mangled name of the @var{decl} in C++). The return value of the\n\
3008 hook is an @code{IDENTIFIER_NODE} for the appropriate mangled name on\n\
3009 your target system. The default implementation of this hook just\n\
3010 returns the @var{id} provided.",
3011 tree, (tree decl, tree id),
3012 default_mangle_decl_assembler_name)
3014 /* Do something target-specific to record properties of the DECL into
3015 the associated SYMBOL_REF. */
3016 DEFHOOK
3017 (encode_section_info,
3018 "Define this hook if references to a symbol or a constant must be\n\
3019 treated differently depending on something about the variable or\n\
3020 function named by the symbol (such as what section it is in).\n\
3022 The hook is executed immediately after rtl has been created for\n\
3023 @var{decl}, which may be a variable or function declaration or\n\
3024 an entry in the constant pool. In either case, @var{rtl} is the\n\
3025 rtl in question. Do @emph{not} use @code{DECL_RTL (@var{decl})}\n\
3026 in this hook; that field may not have been initialized yet.\n\
3028 In the case of a constant, it is safe to assume that the rtl is\n\
3029 a @code{mem} whose address is a @code{symbol_ref}. Most decls\n\
3030 will also have this form, but that is not guaranteed. Global\n\
3031 register variables, for instance, will have a @code{reg} for their\n\
3032 rtl. (Normally the right thing to do with such unusual rtl is\n\
3033 leave it alone.)\n\
3035 The @var{new_decl_p} argument will be true if this is the first time\n\
3036 that @code{TARGET_ENCODE_SECTION_INFO} has been invoked on this decl. It will\n\
3037 be false for subsequent invocations, which will happen for duplicate\n\
3038 declarations. Whether or not anything must be done for the duplicate\n\
3039 declaration depends on whether the hook examines @code{DECL_ATTRIBUTES}.\n\
3040 @var{new_decl_p} is always true when the hook is called for a constant.\n\
3042 @cindex @code{SYMBOL_REF_FLAG}, in @code{TARGET_ENCODE_SECTION_INFO}\n\
3043 The usual thing for this hook to do is to record flags in the\n\
3044 @code{symbol_ref}, using @code{SYMBOL_REF_FLAG} or @code{SYMBOL_REF_FLAGS}.\n\
3045 Historically, the name string was modified if it was necessary to\n\
3046 encode more than one bit of information, but this practice is now\n\
3047 discouraged; use @code{SYMBOL_REF_FLAGS}.\n\
3049 The default definition of this hook, @code{default_encode_section_info}\n\
3050 in @file{varasm.c}, sets a number of commonly-useful bits in\n\
3051 @code{SYMBOL_REF_FLAGS}. Check whether the default does what you need\n\
3052 before overriding it.",
3053 void, (tree decl, rtx rtl, int new_decl_p),
3054 default_encode_section_info)
3056 /* Undo the effects of encode_section_info on the symbol string. */
3057 DEFHOOK
3058 (strip_name_encoding,
3059 "Decode @var{name} and return the real name part, sans\n\
3060 the characters that @code{TARGET_ENCODE_SECTION_INFO}\n\
3061 may have added.",
3062 const char *, (const char *name),
3063 default_strip_name_encoding)
3065 /* If shift optabs for MODE are known to always truncate the shift count,
3066 return the mask that they apply. Return 0 otherwise. */
3067 DEFHOOK
3068 (shift_truncation_mask,
3069 "This function describes how the standard shift patterns for @var{mode}\n\
3070 deal with shifts by negative amounts or by more than the width of the mode.\n\
3071 @xref{shift patterns}.\n\
3073 On many machines, the shift patterns will apply a mask @var{m} to the\n\
3074 shift count, meaning that a fixed-width shift of @var{x} by @var{y} is\n\
3075 equivalent to an arbitrary-width shift of @var{x} by @var{y & m}. If\n\
3076 this is true for mode @var{mode}, the function should return @var{m},\n\
3077 otherwise it should return 0. A return value of 0 indicates that no\n\
3078 particular behavior is guaranteed.\n\
3080 Note that, unlike @code{SHIFT_COUNT_TRUNCATED}, this function does\n\
3081 @emph{not} apply to general shift rtxes; it applies only to instructions\n\
3082 that are generated by the named shift patterns.\n\
3084 The default implementation of this function returns\n\
3085 @code{GET_MODE_BITSIZE (@var{mode}) - 1} if @code{SHIFT_COUNT_TRUNCATED}\n\
3086 and 0 otherwise. This definition is always safe, but if\n\
3087 @code{SHIFT_COUNT_TRUNCATED} is false, and some shift patterns\n\
3088 nevertheless truncate the shift count, you may get better code\n\
3089 by overriding it.",
3090 unsigned HOST_WIDE_INT, (machine_mode mode),
3091 default_shift_truncation_mask)
3093 /* Return the number of divisions in the given MODE that should be present,
3094 so that it is profitable to turn the division into a multiplication by
3095 the reciprocal. */
3096 DEFHOOK
3097 (min_divisions_for_recip_mul,
3098 "When @option{-ffast-math} is in effect, GCC tries to optimize\n\
3099 divisions by the same divisor, by turning them into multiplications by\n\
3100 the reciprocal. This target hook specifies the minimum number of divisions\n\
3101 that should be there for GCC to perform the optimization for a variable\n\
3102 of mode @var{mode}. The default implementation returns 3 if the machine\n\
3103 has an instruction for the division, and 2 if it does not.",
3104 unsigned int, (machine_mode mode),
3105 default_min_divisions_for_recip_mul)
3107 /* If the representation of integral MODE is such that values are
3108 always sign-extended to a wider mode MODE_REP then return
3109 SIGN_EXTEND. Return UNKNOWN otherwise. */
3110 /* Note that the return type ought to be RTX_CODE, but that's not
3111 necessarily defined at this point. */
3112 DEFHOOK
3113 (mode_rep_extended,
3114 "The representation of an integral mode can be such that the values\n\
3115 are always extended to a wider integral mode. Return\n\
3116 @code{SIGN_EXTEND} if values of @var{mode} are represented in\n\
3117 sign-extended form to @var{rep_mode}. Return @code{UNKNOWN}\n\
3118 otherwise. (Currently, none of the targets use zero-extended\n\
3119 representation this way so unlike @code{LOAD_EXTEND_OP},\n\
3120 @code{TARGET_MODE_REP_EXTENDED} is expected to return either\n\
3121 @code{SIGN_EXTEND} or @code{UNKNOWN}. Also no target extends\n\
3122 @var{mode} to @var{rep_mode} so that @var{rep_mode} is not the next\n\
3123 widest integral mode and currently we take advantage of this fact.)\n\
3125 Similarly to @code{LOAD_EXTEND_OP} you may return a non-@code{UNKNOWN}\n\
3126 value even if the extension is not performed on certain hard registers\n\
3127 as long as for the @code{REGNO_REG_CLASS} of these hard registers\n\
3128 @code{CANNOT_CHANGE_MODE_CLASS} returns nonzero.\n\
3130 Note that @code{TARGET_MODE_REP_EXTENDED} and @code{LOAD_EXTEND_OP}\n\
3131 describe two related properties. If you define\n\
3132 @code{TARGET_MODE_REP_EXTENDED (mode, word_mode)} you probably also want\n\
3133 to define @code{LOAD_EXTEND_OP (mode)} to return the same type of\n\
3134 extension.\n\
3136 In order to enforce the representation of @code{mode},\n\
3137 @code{TRULY_NOOP_TRUNCATION} should return false when truncating to\n\
3138 @code{mode}.",
3139 int, (machine_mode mode, machine_mode rep_mode),
3140 default_mode_rep_extended)
3142 /* True if MODE is valid for a pointer in __attribute__((mode("MODE"))). */
3143 DEFHOOK
3144 (valid_pointer_mode,
3145 "Define this to return nonzero if the port can handle pointers\n\
3146 with machine mode @var{mode}. The default version of this\n\
3147 hook returns true for both @code{ptr_mode} and @code{Pmode}.",
3148 bool, (machine_mode mode),
3149 default_valid_pointer_mode)
3151 /* Disambiguate with errno. */
3152 DEFHOOK
3153 (ref_may_alias_errno,
3154 "Define this to return nonzero if the memory reference @var{ref}\
3155 may alias with the system C library errno location. The default\
3156 version of this hook assumes the system C library errno location\
3157 is either a declaration of type int or accessed by dereferencing\
3158 a pointer to int.",
3159 bool, (struct ao_ref *ref),
3160 default_ref_may_alias_errno)
3162 /* Support for named address spaces. */
3163 #undef HOOK_PREFIX
3164 #define HOOK_PREFIX "TARGET_ADDR_SPACE_"
3165 HOOK_VECTOR (TARGET_ADDR_SPACE_HOOKS, addr_space)
3167 /* MODE to use for a pointer into another address space. */
3168 DEFHOOK
3169 (pointer_mode,
3170 "Define this to return the machine mode to use for pointers to\n\
3171 @var{address_space} if the target supports named address spaces.\n\
3172 The default version of this hook returns @code{ptr_mode}.",
3173 machine_mode, (addr_space_t address_space),
3174 default_addr_space_pointer_mode)
3176 /* MODE to use for an address in another address space. */
3177 DEFHOOK
3178 (address_mode,
3179 "Define this to return the machine mode to use for addresses in\n\
3180 @var{address_space} if the target supports named address spaces.\n\
3181 The default version of this hook returns @code{Pmode}.",
3182 machine_mode, (addr_space_t address_space),
3183 default_addr_space_address_mode)
3185 /* True if MODE is valid for a pointer in __attribute__((mode("MODE")))
3186 in another address space. */
3187 DEFHOOK
3188 (valid_pointer_mode,
3189 "Define this to return nonzero if the port can handle pointers\n\
3190 with machine mode @var{mode} to address space @var{as}. This target\n\
3191 hook is the same as the @code{TARGET_VALID_POINTER_MODE} target hook,\n\
3192 except that it includes explicit named address space support. The default\n\
3193 version of this hook returns true for the modes returned by either the\n\
3194 @code{TARGET_ADDR_SPACE_POINTER_MODE} or @code{TARGET_ADDR_SPACE_ADDRESS_MODE}\n\
3195 target hooks for the given address space.",
3196 bool, (machine_mode mode, addr_space_t as),
3197 default_addr_space_valid_pointer_mode)
3199 /* True if an address is a valid memory address to a given named address
3200 space for a given mode. */
3201 DEFHOOK
3202 (legitimate_address_p,
3203 "Define this to return true if @var{exp} is a valid address for mode\n\
3204 @var{mode} in the named address space @var{as}. The @var{strict}\n\
3205 parameter says whether strict addressing is in effect after reload has\n\
3206 finished. This target hook is the same as the\n\
3207 @code{TARGET_LEGITIMATE_ADDRESS_P} target hook, except that it includes\n\
3208 explicit named address space support.",
3209 bool, (machine_mode mode, rtx exp, bool strict, addr_space_t as),
3210 default_addr_space_legitimate_address_p)
3212 /* Return an updated address to convert an invalid pointer to a named
3213 address space to a valid one. If NULL_RTX is returned use machine
3214 independent methods to make the address valid. */
3215 DEFHOOK
3216 (legitimize_address,
3217 "Define this to modify an invalid address @var{x} to be a valid address\n\
3218 with mode @var{mode} in the named address space @var{as}. This target\n\
3219 hook is the same as the @code{TARGET_LEGITIMIZE_ADDRESS} target hook,\n\
3220 except that it includes explicit named address space support.",
3221 rtx, (rtx x, rtx oldx, machine_mode mode, addr_space_t as),
3222 default_addr_space_legitimize_address)
3224 /* True if one named address space is a subset of another named address. */
3225 DEFHOOK
3226 (subset_p,
3227 "Define this to return whether the @var{subset} named address space is\n\
3228 contained within the @var{superset} named address space. Pointers to\n\
3229 a named address space that is a subset of another named address space\n\
3230 will be converted automatically without a cast if used together in\n\
3231 arithmetic operations. Pointers to a superset address space can be\n\
3232 converted to pointers to a subset address space via explicit casts.",
3233 bool, (addr_space_t subset, addr_space_t superset),
3234 default_addr_space_subset_p)
3236 /* True if 0 is a valid address in the address space, or false if
3237 0 is a NULL in the address space. */
3238 DEFHOOK
3239 (zero_address_valid,
3240 "Define this to modify the default handling of address 0 for the\n\
3241 address space. Return true if 0 should be considered a valid address.",
3242 bool, (addr_space_t as),
3243 default_addr_space_zero_address_valid)
3245 /* Function to convert an rtl expression from one address space to another. */
3246 DEFHOOK
3247 (convert,
3248 "Define this to convert the pointer expression represented by the RTL\n\
3249 @var{op} with type @var{from_type} that points to a named address\n\
3250 space to a new pointer expression with type @var{to_type} that points\n\
3251 to a different named address space. When this hook it called, it is\n\
3252 guaranteed that one of the two address spaces is a subset of the other,\n\
3253 as determined by the @code{TARGET_ADDR_SPACE_SUBSET_P} target hook.",
3254 rtx, (rtx op, tree from_type, tree to_type),
3255 default_addr_space_convert)
3257 /* Function to encode an address space into dwarf. */
3258 DEFHOOK
3259 (debug,
3260 "Define this to define how the address space is encoded in dwarf.\n\
3261 The result is the value to be used with @code{DW_AT_address_class}.",
3262 int, (addr_space_t as),
3263 default_addr_space_debug)
3265 /* Function to emit custom diagnostic if an address space is used. */
3266 DEFHOOK
3267 (diagnose_usage,
3268 "Define this hook if the availability of an address space depends on\n\
3269 command line options and some diagnostics should be printed when the\n\
3270 address space is used. This hook is called during parsing and allows\n\
3271 to emit a better diagnostic compared to the case where the address space\n\
3272 was not registered with @code{c_register_addr_space}. @var{as} is\n\
3273 the address space as registered with @code{c_register_addr_space}.\n\
3274 @var{loc} is the location of the address space qualifier token.\n\
3275 The default implementation does nothing.",
3276 void, (addr_space_t as, location_t loc),
3277 default_addr_space_diagnose_usage)
3279 HOOK_VECTOR_END (addr_space)
3281 #undef HOOK_PREFIX
3282 #define HOOK_PREFIX "TARGET_"
3284 /* True if MODE is valid for the target. By "valid", we mean able to
3285 be manipulated in non-trivial ways. In particular, this means all
3286 the arithmetic is supported. */
3287 DEFHOOK
3288 (scalar_mode_supported_p,
3289 "Define this to return nonzero if the port is prepared to handle\n\
3290 insns involving scalar mode @var{mode}. For a scalar mode to be\n\
3291 considered supported, all the basic arithmetic and comparisons\n\
3292 must work.\n\
3294 The default version of this hook returns true for any mode\n\
3295 required to handle the basic C types (as defined by the port).\n\
3296 Included here are the double-word arithmetic supported by the\n\
3297 code in @file{optabs.c}.",
3298 bool, (machine_mode mode),
3299 default_scalar_mode_supported_p)
3301 /* Similarly for vector modes. "Supported" here is less strict. At
3302 least some operations are supported; need to check optabs or builtins
3303 for further details. */
3304 DEFHOOK
3305 (vector_mode_supported_p,
3306 "Define this to return nonzero if the port is prepared to handle\n\
3307 insns involving vector mode @var{mode}. At the very least, it\n\
3308 must have move patterns for this mode.",
3309 bool, (machine_mode mode),
3310 hook_bool_mode_false)
3312 DEFHOOK
3313 (vector_alignment,
3314 "This hook can be used to define the alignment for a vector of type\n\
3315 @var{type}, in order to comply with a platform ABI. The default is to\n\
3316 require natural alignment for vector types. The alignment returned by\n\
3317 this hook must be a power-of-two multiple of the default alignment of\n\
3318 the vector element type.",
3319 HOST_WIDE_INT, (const_tree type),
3320 default_vector_alignment)
3322 /* True if we should try to use a scalar mode to represent an array,
3323 overriding the usual MAX_FIXED_MODE limit. */
3324 DEFHOOK
3325 (array_mode_supported_p,
3326 "Return true if GCC should try to use a scalar mode to store an array\n\
3327 of @var{nelems} elements, given that each element has mode @var{mode}.\n\
3328 Returning true here overrides the usual @code{MAX_FIXED_MODE} limit\n\
3329 and allows GCC to use any defined integer mode.\n\
3331 One use of this hook is to support vector load and store operations\n\
3332 that operate on several homogeneous vectors. For example, ARM NEON\n\
3333 has operations like:\n\
3335 @smallexample\n\
3336 int8x8x3_t vld3_s8 (const int8_t *)\n\
3337 @end smallexample\n\
3339 where the return type is defined as:\n\
3341 @smallexample\n\
3342 typedef struct int8x8x3_t\n\
3343 @{\n\
3344 int8x8_t val[3];\n\
3345 @} int8x8x3_t;\n\
3346 @end smallexample\n\
3348 If this hook allows @code{val} to have a scalar mode, then\n\
3349 @code{int8x8x3_t} can have the same mode. GCC can then store\n\
3350 @code{int8x8x3_t}s in registers rather than forcing them onto the stack.",
3351 bool, (machine_mode mode, unsigned HOST_WIDE_INT nelems),
3352 hook_bool_mode_uhwi_false)
3354 DEFHOOK
3355 (libgcc_floating_mode_supported_p,
3356 "Define this to return nonzero if libgcc provides support for the \n\
3357 floating-point mode @var{mode}, which is known to pass \n\
3358 @code{TARGET_SCALAR_MODE_SUPPORTED_P}. The default version of this \n\
3359 hook returns true for all of @code{SFmode}, @code{DFmode}, \n\
3360 @code{XFmode} and @code{TFmode}, if such modes exist.",
3361 bool, (machine_mode mode),
3362 default_libgcc_floating_mode_supported_p)
3364 DEFHOOK
3365 (floatn_mode,
3366 "Define this to return the machine mode to use for the type \n\
3367 @code{_Float@var{n}}, if @var{extended} is false, or the type \n\
3368 @code{_Float@var{n}x}, if @var{extended} is true. If such a type \n\
3369 is not supported, return @code{VOIDmode}. The default version of this \n\
3370 hook returns @code{SFmode} for @code{_Float32}, @code{DFmode} for \n\
3371 @code{_Float64} and @code{_Float32x} and @code{TFmode} for \n\
3372 @code{_Float128}, if those modes exist and satisfy the requirements for \n\
3373 those types and pass @code{TARGET_SCALAR_MODE_SUPPORTED_P} and \n\
3374 @code{TARGET_LIBGCC_FLOATING_MODE_SUPPORTED_P}; for @code{_Float64x}, it \n\
3375 returns the first of @code{XFmode} and @code{TFmode} that exists and \n\
3376 satisfies the same requirements; for other types, it returns \n\
3377 @code{VOIDmode}. The hook is only called for values of @var{n} and \n\
3378 @var{extended} that are valid according to ISO/IEC TS 18661-3:2015; that \n\
3379 is, @var{n} is one of 32, 64, 128, or, if @var{extended} is false, 16 or \n\
3380 greater than 128 and a multiple of 32.",
3381 machine_mode, (int n, bool extended),
3382 default_floatn_mode)
3384 /* Compute cost of moving data from a register of class FROM to one of
3385 TO, using MODE. */
3386 DEFHOOK
3387 (register_move_cost,
3388 "This target hook should return the cost of moving data of mode @var{mode}\n\
3389 from a register in class @var{from} to one in class @var{to}. The classes\n\
3390 are expressed using the enumeration values such as @code{GENERAL_REGS}.\n\
3391 A value of 2 is the default; other values are interpreted relative to\n\
3392 that.\n\
3394 It is not required that the cost always equal 2 when @var{from} is the\n\
3395 same as @var{to}; on some machines it is expensive to move between\n\
3396 registers if they are not general registers.\n\
3398 If reload sees an insn consisting of a single @code{set} between two\n\
3399 hard registers, and if @code{TARGET_REGISTER_MOVE_COST} applied to their\n\
3400 classes returns a value of 2, reload does not check to ensure that the\n\
3401 constraints of the insn are met. Setting a cost of other than 2 will\n\
3402 allow reload to verify that the constraints are met. You should do this\n\
3403 if the @samp{mov@var{m}} pattern's constraints do not allow such copying.\n\
3405 The default version of this function returns 2.",
3406 int, (machine_mode mode, reg_class_t from, reg_class_t to),
3407 default_register_move_cost)
3409 /* Compute cost of moving registers to/from memory. */
3410 /* ??? Documenting the argument types for this hook requires a GFDL
3411 license grant. Also, the documentation uses a different name for RCLASS. */
3412 DEFHOOK
3413 (memory_move_cost,
3414 "This target hook should return the cost of moving data of mode @var{mode}\n\
3415 between a register of class @var{rclass} and memory; @var{in} is @code{false}\n\
3416 if the value is to be written to memory, @code{true} if it is to be read in.\n\
3417 This cost is relative to those in @code{TARGET_REGISTER_MOVE_COST}.\n\
3418 If moving between registers and memory is more expensive than between two\n\
3419 registers, you should add this target hook to express the relative cost.\n\
3421 If you do not add this target hook, GCC uses a default cost of 4 plus\n\
3422 the cost of copying via a secondary reload register, if one is\n\
3423 needed. If your machine requires a secondary reload register to copy\n\
3424 between memory and a register of @var{rclass} but the reload mechanism is\n\
3425 more complex than copying via an intermediate, use this target hook to\n\
3426 reflect the actual cost of the move.\n\
3428 GCC defines the function @code{memory_move_secondary_cost} if\n\
3429 secondary reloads are needed. It computes the costs due to copying via\n\
3430 a secondary register. If your machine copies from memory using a\n\
3431 secondary register in the conventional way but the default base value of\n\
3432 4 is not correct for your machine, use this target hook to add some other\n\
3433 value to the result of that function. The arguments to that function\n\
3434 are the same as to this target hook.",
3435 int, (machine_mode mode, reg_class_t rclass, bool in),
3436 default_memory_move_cost)
3438 DEFHOOK
3439 (use_by_pieces_infrastructure_p,
3440 "GCC will attempt several strategies when asked to copy between\n\
3441 two areas of memory, or to set, clear or store to memory, for example\n\
3442 when copying a @code{struct}. The @code{by_pieces} infrastructure\n\
3443 implements such memory operations as a sequence of load, store or move\n\
3444 insns. Alternate strategies are to expand the\n\
3445 @code{movmem} or @code{setmem} optabs, to emit a library call, or to emit\n\
3446 unit-by-unit, loop-based operations.\n\
3448 This target hook should return true if, for a memory operation with a\n\
3449 given @var{size} and @var{alignment}, using the @code{by_pieces}\n\
3450 infrastructure is expected to result in better code generation.\n\
3451 Both @var{size} and @var{alignment} are measured in terms of storage\n\
3452 units.\n\
3454 The parameter @var{op} is one of: @code{CLEAR_BY_PIECES},\n\
3455 @code{MOVE_BY_PIECES}, @code{SET_BY_PIECES}, @code{STORE_BY_PIECES} or\n\
3456 @code{COMPARE_BY_PIECES}. These describe the type of memory operation\n\
3457 under consideration.\n\
3459 The parameter @var{speed_p} is true if the code is currently being\n\
3460 optimized for speed rather than size.\n\
3462 Returning true for higher values of @var{size} can improve code generation\n\
3463 for speed if the target does not provide an implementation of the\n\
3464 @code{movmem} or @code{setmem} standard names, if the @code{movmem} or\n\
3465 @code{setmem} implementation would be more expensive than a sequence of\n\
3466 insns, or if the overhead of a library call would dominate that of\n\
3467 the body of the memory operation.\n\
3469 Returning true for higher values of @code{size} may also cause an increase\n\
3470 in code size, for example where the number of insns emitted to perform a\n\
3471 move would be greater than that of a library call.",
3472 bool, (unsigned HOST_WIDE_INT size, unsigned int alignment,
3473 enum by_pieces_operation op, bool speed_p),
3474 default_use_by_pieces_infrastructure_p)
3476 DEFHOOK
3477 (compare_by_pieces_branch_ratio,
3478 "When expanding a block comparison in MODE, gcc can try to reduce the\n\
3479 number of branches at the expense of more memory operations. This hook\n\
3480 allows the target to override the default choice. It should return the\n\
3481 factor by which branches should be reduced over the plain expansion with\n\
3482 one comparison per @var{mode}-sized piece. A port can also prevent a\n\
3483 particular mode from being used for block comparisons by returning a\n\
3484 negative number from this hook.",
3485 int, (machine_mode mode),
3486 default_compare_by_pieces_branch_ratio)
3488 DEFHOOK
3489 (optab_supported_p,
3490 "Return true if the optimizers should use optab @var{op} with\n\
3491 modes @var{mode1} and @var{mode2} for optimization type @var{opt_type}.\n\
3492 The optab is known to have an associated @file{.md} instruction\n\
3493 whose C condition is true. @var{mode2} is only meaningful for conversion\n\
3494 optabs; for direct optabs it is a copy of @var{mode1}.\n\
3496 For example, when called with @var{op} equal to @code{rint_optab} and\n\
3497 @var{mode1} equal to @code{DFmode}, the hook should say whether the\n\
3498 optimizers should use optab @code{rintdf2}.\n\
3500 The default hook returns true for all inputs.",
3501 bool, (int op, machine_mode mode1, machine_mode mode2,
3502 optimization_type opt_type),
3503 default_optab_supported_p)
3505 /* True for MODE if the target expects that registers in this mode will
3506 be allocated to registers in a small register class. The compiler is
3507 allowed to use registers explicitly used in the rtl as spill registers
3508 but it should prevent extending the lifetime of these registers. */
3509 DEFHOOK
3510 (small_register_classes_for_mode_p,
3511 "Define this to return nonzero for machine modes for which the port has\n\
3512 small register classes. If this target hook returns nonzero for a given\n\
3513 @var{mode}, the compiler will try to minimize the lifetime of registers\n\
3514 in @var{mode}. The hook may be called with @code{VOIDmode} as argument.\n\
3515 In this case, the hook is expected to return nonzero if it returns nonzero\n\
3516 for any mode.\n\
3518 On some machines, it is risky to let hard registers live across arbitrary\n\
3519 insns. Typically, these machines have instructions that require values\n\
3520 to be in specific registers (like an accumulator), and reload will fail\n\
3521 if the required hard register is used for another purpose across such an\n\
3522 insn.\n\
3524 Passes before reload do not know which hard registers will be used\n\
3525 in an instruction, but the machine modes of the registers set or used in\n\
3526 the instruction are already known. And for some machines, register\n\
3527 classes are small for, say, integer registers but not for floating point\n\
3528 registers. For example, the AMD x86-64 architecture requires specific\n\
3529 registers for the legacy x86 integer instructions, but there are many\n\
3530 SSE registers for floating point operations. On such targets, a good\n\
3531 strategy may be to return nonzero from this hook for @code{INTEGRAL_MODE_P}\n\
3532 machine modes but zero for the SSE register classes.\n\
3534 The default version of this hook returns false for any mode. It is always\n\
3535 safe to redefine this hook to return with a nonzero value. But if you\n\
3536 unnecessarily define it, you will reduce the amount of optimizations\n\
3537 that can be performed in some cases. If you do not define this hook\n\
3538 to return a nonzero value when it is required, the compiler will run out\n\
3539 of spill registers and print a fatal error message.",
3540 bool, (machine_mode mode),
3541 hook_bool_mode_false)
3543 /* Register number for a flags register. Only needs to be defined if the
3544 target is constrainted to use post-reload comparison elimination. */
3545 DEFHOOKPOD
3546 (flags_regnum,
3547 "If the target has a dedicated flags register, and it needs to use the\
3548 post-reload comparison elimination pass, then this value should be set\
3549 appropriately.",
3550 unsigned int, INVALID_REGNUM)
3552 /* Compute a (partial) cost for rtx X. Return true if the complete
3553 cost has been computed, and false if subexpressions should be
3554 scanned. In either case, *TOTAL contains the cost result. */
3555 /* Note that OUTER_CODE ought to be RTX_CODE, but that's
3556 not necessarily defined at this point. */
3557 DEFHOOK
3558 (rtx_costs,
3559 "This target hook describes the relative costs of RTL expressions.\n\
3561 The cost may depend on the precise form of the expression, which is\n\
3562 available for examination in @var{x}, and the fact that @var{x} appears\n\
3563 as operand @var{opno} of an expression with rtx code @var{outer_code}.\n\
3564 That is, the hook can assume that there is some rtx @var{y} such\n\
3565 that @samp{GET_CODE (@var{y}) == @var{outer_code}} and such that\n\
3566 either (a) @samp{XEXP (@var{y}, @var{opno}) == @var{x}} or\n\
3567 (b) @samp{XVEC (@var{y}, @var{opno})} contains @var{x}.\n\
3569 @var{mode} is @var{x}'s machine mode, or for cases like @code{const_int} that\n\
3570 do not have a mode, the mode in which @var{x} is used.\n\
3572 In implementing this hook, you can use the construct\n\
3573 @code{COSTS_N_INSNS (@var{n})} to specify a cost equal to @var{n} fast\n\
3574 instructions.\n\
3576 On entry to the hook, @code{*@var{total}} contains a default estimate\n\
3577 for the cost of the expression. The hook should modify this value as\n\
3578 necessary. Traditionally, the default costs are @code{COSTS_N_INSNS (5)}\n\
3579 for multiplications, @code{COSTS_N_INSNS (7)} for division and modulus\n\
3580 operations, and @code{COSTS_N_INSNS (1)} for all other operations.\n\
3582 When optimizing for code size, i.e.@: when @code{speed} is\n\
3583 false, this target hook should be used to estimate the relative\n\
3584 size cost of an expression, again relative to @code{COSTS_N_INSNS}.\n\
3586 The hook returns true when all subexpressions of @var{x} have been\n\
3587 processed, and false when @code{rtx_cost} should recurse.",
3588 bool, (rtx x, machine_mode mode, int outer_code, int opno, int *total, bool speed),
3589 hook_bool_rtx_mode_int_int_intp_bool_false)
3591 /* Compute the cost of X, used as an address. Never called with
3592 invalid addresses. */
3593 DEFHOOK
3594 (address_cost,
3595 "This hook computes the cost of an addressing mode that contains\n\
3596 @var{address}. If not defined, the cost is computed from\n\
3597 the @var{address} expression and the @code{TARGET_RTX_COST} hook.\n\
3599 For most CISC machines, the default cost is a good approximation of the\n\
3600 true cost of the addressing mode. However, on RISC machines, all\n\
3601 instructions normally have the same length and execution time. Hence\n\
3602 all addresses will have equal costs.\n\
3604 In cases where more than one form of an address is known, the form with\n\
3605 the lowest cost will be used. If multiple forms have the same, lowest,\n\
3606 cost, the one that is the most complex will be used.\n\
3608 For example, suppose an address that is equal to the sum of a register\n\
3609 and a constant is used twice in the same basic block. When this macro\n\
3610 is not defined, the address will be computed in a register and memory\n\
3611 references will be indirect through that register. On machines where\n\
3612 the cost of the addressing mode containing the sum is no higher than\n\
3613 that of a simple indirect reference, this will produce an additional\n\
3614 instruction and possibly require an additional register. Proper\n\
3615 specification of this macro eliminates this overhead for such machines.\n\
3617 This hook is never called with an invalid address.\n\
3619 On machines where an address involving more than one register is as\n\
3620 cheap as an address computation involving only one register, defining\n\
3621 @code{TARGET_ADDRESS_COST} to reflect this can cause two registers to\n\
3622 be live over a region of code where only one would have been if\n\
3623 @code{TARGET_ADDRESS_COST} were not defined in that manner. This effect\n\
3624 should be considered in the definition of this macro. Equivalent costs\n\
3625 should probably only be given to addresses with different numbers of\n\
3626 registers on machines with lots of registers.",
3627 int, (rtx address, machine_mode mode, addr_space_t as, bool speed),
3628 default_address_cost)
3630 /* Give a cost, in RTX Costs units, for an edge. Like BRANCH_COST, but with
3631 well defined units. */
3632 DEFHOOK
3633 (max_noce_ifcvt_seq_cost,
3634 "This hook returns a value in the same units as @code{TARGET_RTX_COSTS},\n\
3635 giving the maximum acceptable cost for a sequence generated by the RTL\n\
3636 if-conversion pass when conditional execution is not available.\n\
3637 The RTL if-conversion pass attempts to convert conditional operations\n\
3638 that would require a branch to a series of unconditional operations and\n\
3639 @code{mov@var{mode}cc} insns. This hook returns the maximum cost of the\n\
3640 unconditional instructions and the @code{mov@var{mode}cc} insns.\n\
3641 RTL if-conversion is cancelled if the cost of the converted sequence\n\
3642 is greater than the value returned by this hook.\n\
3644 @code{e} is the edge between the basic block containing the conditional\n\
3645 branch to the basic block which would be executed if the condition\n\
3646 were true.\n\
3648 The default implementation of this hook uses the\n\
3649 @code{max-rtl-if-conversion-[un]predictable} parameters if they are set,\n\
3650 and uses a multiple of @code{BRANCH_COST} otherwise.",
3651 unsigned int, (edge e),
3652 default_max_noce_ifcvt_seq_cost)
3654 /* Permit speculative instructions in delay slots during delayed-branch
3655 scheduling. */
3656 DEFHOOK
3657 (no_speculation_in_delay_slots_p,
3658 "This predicate controls the use of the eager delay slot filler to disallow\n\
3659 speculatively executed instructions being placed in delay slots. Targets\n\
3660 such as certain MIPS architectures possess both branches with and without\n\
3661 delay slots. As the eager delay slot filler can decrease performance,\n\
3662 disabling it is beneficial when ordinary branches are available. Use of\n\
3663 delay slot branches filled using the basic filler is often still desirable\n\
3664 as the delay slot can hide a pipeline bubble.", bool, (void),
3665 hook_bool_void_false)
3667 /* Return where to allocate pseudo for a given hard register initial value. */
3668 DEFHOOK
3669 (allocate_initial_value,
3670 "\n\
3671 When the initial value of a hard register has been copied in a pseudo\n\
3672 register, it is often not necessary to actually allocate another register\n\
3673 to this pseudo register, because the original hard register or a stack slot\n\
3674 it has been saved into can be used. @code{TARGET_ALLOCATE_INITIAL_VALUE}\n\
3675 is called at the start of register allocation once for each hard register\n\
3676 that had its initial value copied by using\n\
3677 @code{get_func_hard_reg_initial_val} or @code{get_hard_reg_initial_val}.\n\
3678 Possible values are @code{NULL_RTX}, if you don't want\n\
3679 to do any special allocation, a @code{REG} rtx---that would typically be\n\
3680 the hard register itself, if it is known not to be clobbered---or a\n\
3681 @code{MEM}.\n\
3682 If you are returning a @code{MEM}, this is only a hint for the allocator;\n\
3683 it might decide to use another register anyways.\n\
3684 You may use @code{current_function_is_leaf} or \n\
3685 @code{REG_N_SETS} in the hook to determine if the hard\n\
3686 register in question will not be clobbered.\n\
3687 The default value of this hook is @code{NULL}, which disables any special\n\
3688 allocation.",
3689 rtx, (rtx hard_reg), NULL)
3691 /* Return nonzero if evaluating UNSPEC X might cause a trap.
3692 FLAGS has the same meaning as in rtlanal.c: may_trap_p_1. */
3693 DEFHOOK
3694 (unspec_may_trap_p,
3695 "This target hook returns nonzero if @var{x}, an @code{unspec} or\n\
3696 @code{unspec_volatile} operation, might cause a trap. Targets can use\n\
3697 this hook to enhance precision of analysis for @code{unspec} and\n\
3698 @code{unspec_volatile} operations. You may call @code{may_trap_p_1}\n\
3699 to analyze inner elements of @var{x} in which case @var{flags} should be\n\
3700 passed along.",
3701 int, (const_rtx x, unsigned flags),
3702 default_unspec_may_trap_p)
3704 /* Given a register, this hook should return a parallel of registers
3705 to represent where to find the register pieces. Define this hook
3706 if the register and its mode are represented in Dwarf in
3707 non-contiguous locations, or if the register should be
3708 represented in more than one register in Dwarf. Otherwise, this
3709 hook should return NULL_RTX. */
3710 DEFHOOK
3711 (dwarf_register_span,
3712 "Given a register, this hook should return a parallel of registers to\n\
3713 represent where to find the register pieces. Define this hook if the\n\
3714 register and its mode are represented in Dwarf in non-contiguous\n\
3715 locations, or if the register should be represented in more than one\n\
3716 register in Dwarf. Otherwise, this hook should return @code{NULL_RTX}.\n\
3717 If not defined, the default is to return @code{NULL_RTX}.",
3718 rtx, (rtx reg),
3719 hook_rtx_rtx_null)
3721 /* Given a register return the mode of the corresponding DWARF frame
3722 register. */
3723 DEFHOOK
3724 (dwarf_frame_reg_mode,
3725 "Given a register, this hook should return the mode which the\n\
3726 corresponding Dwarf frame register should have. This is normally\n\
3727 used to return a smaller mode than the raw mode to prevent call\n\
3728 clobbered parts of a register altering the frame register size",
3729 machine_mode, (int regno),
3730 default_dwarf_frame_reg_mode)
3732 /* If expand_builtin_init_dwarf_reg_sizes needs to fill in table
3733 entries not corresponding directly to registers below
3734 FIRST_PSEUDO_REGISTER, this hook should generate the necessary
3735 code, given the address of the table. */
3736 DEFHOOK
3737 (init_dwarf_reg_sizes_extra,
3738 "If some registers are represented in Dwarf-2 unwind information in\n\
3739 multiple pieces, define this hook to fill in information about the\n\
3740 sizes of those pieces in the table used by the unwinder at runtime.\n\
3741 It will be called by @code{expand_builtin_init_dwarf_reg_sizes} after\n\
3742 filling in a single size corresponding to each hard register;\n\
3743 @var{address} is the address of the table.",
3744 void, (tree address),
3745 hook_void_tree)
3747 /* Fetch the fixed register(s) which hold condition codes, for
3748 targets where it makes sense to look for duplicate assignments to
3749 the condition codes. This should return true if there is such a
3750 register, false otherwise. The arguments should be set to the
3751 fixed register numbers. Up to two condition code registers are
3752 supported. If there is only one for this target, the int pointed
3753 at by the second argument should be set to -1. */
3754 DEFHOOK
3755 (fixed_condition_code_regs,
3756 "On targets which do not use @code{(cc0)}, and which use a hard\n\
3757 register rather than a pseudo-register to hold condition codes, the\n\
3758 regular CSE passes are often not able to identify cases in which the\n\
3759 hard register is set to a common value. Use this hook to enable a\n\
3760 small pass which optimizes such cases. This hook should return true\n\
3761 to enable this pass, and it should set the integers to which its\n\
3762 arguments point to the hard register numbers used for condition codes.\n\
3763 When there is only one such register, as is true on most systems, the\n\
3764 integer pointed to by @var{p2} should be set to\n\
3765 @code{INVALID_REGNUM}.\n\
3767 The default version of this hook returns false.",
3768 bool, (unsigned int *p1, unsigned int *p2),
3769 hook_bool_uintp_uintp_false)
3771 /* If two condition code modes are compatible, return a condition
3772 code mode which is compatible with both, such that a comparison
3773 done in the returned mode will work for both of the original
3774 modes. If the condition code modes are not compatible, return
3775 VOIDmode. */
3776 DEFHOOK
3777 (cc_modes_compatible,
3778 "On targets which use multiple condition code modes in class\n\
3779 @code{MODE_CC}, it is sometimes the case that a comparison can be\n\
3780 validly done in more than one mode. On such a system, define this\n\
3781 target hook to take two mode arguments and to return a mode in which\n\
3782 both comparisons may be validly done. If there is no such mode,\n\
3783 return @code{VOIDmode}.\n\
3785 The default version of this hook checks whether the modes are the\n\
3786 same. If they are, it returns that mode. If they are different, it\n\
3787 returns @code{VOIDmode}.",
3788 machine_mode, (machine_mode m1, machine_mode m2),
3789 default_cc_modes_compatible)
3791 /* Do machine-dependent code transformations. Called just before
3792 delayed-branch scheduling. */
3793 DEFHOOK
3794 (machine_dependent_reorg,
3795 "If non-null, this hook performs a target-specific pass over the\n\
3796 instruction stream. The compiler will run it at all optimization levels,\n\
3797 just before the point at which it normally does delayed-branch scheduling.\n\
3799 The exact purpose of the hook varies from target to target. Some use\n\
3800 it to do transformations that are necessary for correctness, such as\n\
3801 laying out in-function constant pools or avoiding hardware hazards.\n\
3802 Others use it as an opportunity to do some machine-dependent optimizations.\n\
3804 You need not implement the hook if it has nothing to do. The default\n\
3805 definition is null.",
3806 void, (void), NULL)
3808 /* Create the __builtin_va_list type. */
3809 DEFHOOK
3810 (build_builtin_va_list,
3811 "This hook returns a type node for @code{va_list} for the target.\n\
3812 The default version of the hook returns @code{void*}.",
3813 tree, (void),
3814 std_build_builtin_va_list)
3816 /* Enumerate the va list variants. */
3817 DEFHOOK
3818 (enum_va_list_p,
3819 "This target hook is used in function @code{c_common_nodes_and_builtins}\n\
3820 to iterate through the target specific builtin types for va_list. The\n\
3821 variable @var{idx} is used as iterator. @var{pname} has to be a pointer\n\
3822 to a @code{const char *} and @var{ptree} a pointer to a @code{tree} typed\n\
3823 variable.\n\
3824 The arguments @var{pname} and @var{ptree} are used to store the result of\n\
3825 this macro and are set to the name of the va_list builtin type and its\n\
3826 internal type.\n\
3827 If the return value of this macro is zero, then there is no more element.\n\
3828 Otherwise the @var{IDX} should be increased for the next call of this\n\
3829 macro to iterate through all types.",
3830 int, (int idx, const char **pname, tree *ptree),
3831 NULL)
3833 /* Get the cfun/fndecl calling abi __builtin_va_list type. */
3834 DEFHOOK
3835 (fn_abi_va_list,
3836 "This hook returns the va_list type of the calling convention specified by\n\
3837 @var{fndecl}.\n\
3838 The default version of this hook returns @code{va_list_type_node}.",
3839 tree, (tree fndecl),
3840 std_fn_abi_va_list)
3842 /* Get the __builtin_va_list type dependent on input type. */
3843 DEFHOOK
3844 (canonical_va_list_type,
3845 "This hook returns the va_list type of the calling convention specified by the\n\
3846 type of @var{type}. If @var{type} is not a valid va_list type, it returns\n\
3847 @code{NULL_TREE}.",
3848 tree, (tree type),
3849 std_canonical_va_list_type)
3851 /* ??? Documenting this hook requires a GFDL license grant. */
3852 DEFHOOK_UNDOC
3853 (expand_builtin_va_start,
3854 "Expand the @code{__builtin_va_start} builtin.",
3855 void, (tree valist, rtx nextarg), NULL)
3857 /* Gimplifies a VA_ARG_EXPR. */
3858 DEFHOOK
3859 (gimplify_va_arg_expr,
3860 "This hook performs target-specific gimplification of\n\
3861 @code{VA_ARG_EXPR}. The first two parameters correspond to the\n\
3862 arguments to @code{va_arg}; the latter two are as in\n\
3863 @code{gimplify.c:gimplify_expr}.",
3864 tree, (tree valist, tree type, gimple_seq *pre_p, gimple_seq *post_p),
3865 std_gimplify_va_arg_expr)
3867 /* Validity-checking routines for PCH files, target-specific.
3868 get_pch_validity returns a pointer to the data to be stored,
3869 and stores the size in its argument. pch_valid_p gets the same
3870 information back and returns NULL if the PCH is valid,
3871 or an error message if not. */
3872 DEFHOOK
3873 (get_pch_validity,
3874 "This hook returns a pointer to the data needed by\n\
3875 @code{TARGET_PCH_VALID_P} and sets\n\
3876 @samp{*@var{sz}} to the size of the data in bytes.",
3877 void *, (size_t *sz),
3878 default_get_pch_validity)
3880 DEFHOOK
3881 (pch_valid_p,
3882 "This hook checks whether the options used to create a PCH file are\n\
3883 compatible with the current settings. It returns @code{NULL}\n\
3884 if so and a suitable error message if not. Error messages will\n\
3885 be presented to the user and must be localized using @samp{_(@var{msg})}.\n\
3887 @var{data} is the data that was returned by @code{TARGET_GET_PCH_VALIDITY}\n\
3888 when the PCH file was created and @var{sz} is the size of that data in bytes.\n\
3889 It's safe to assume that the data was created by the same version of the\n\
3890 compiler, so no format checking is needed.\n\
3892 The default definition of @code{default_pch_valid_p} should be\n\
3893 suitable for most targets.",
3894 const char *, (const void *data, size_t sz),
3895 default_pch_valid_p)
3897 DEFHOOK
3898 (prepare_pch_save,
3899 "Called before writing out a PCH file. If the target has some\n\
3900 garbage-collected data that needs to be in a particular state on PCH loads,\n\
3901 it can use this hook to enforce that state. Very few targets need\n\
3902 to do anything here.",
3903 void, (void),
3904 hook_void_void)
3906 /* If nonnull, this function checks whether a PCH file with the
3907 given set of target flags can be used. It returns NULL if so,
3908 otherwise it returns an error message. */
3909 DEFHOOK
3910 (check_pch_target_flags,
3911 "If this hook is nonnull, the default implementation of\n\
3912 @code{TARGET_PCH_VALID_P} will use it to check for compatible values\n\
3913 of @code{target_flags}. @var{pch_flags} specifies the value that\n\
3914 @code{target_flags} had when the PCH file was created. The return\n\
3915 value is the same as for @code{TARGET_PCH_VALID_P}.",
3916 const char *, (int pch_flags), NULL)
3918 /* True if the compiler should give an enum type only as many
3919 bytes as it takes to represent the range of possible values of
3920 that type. */
3921 DEFHOOK
3922 (default_short_enums,
3923 "This target hook should return true if the compiler should give an\n\
3924 @code{enum} type only as many bytes as it takes to represent the range\n\
3925 of possible values of that type. It should return false if all\n\
3926 @code{enum} types should be allocated like @code{int}.\n\
3928 The default is to return false.",
3929 bool, (void),
3930 hook_bool_void_false)
3932 /* This target hook returns an rtx that is used to store the address
3933 of the current frame into the built-in setjmp buffer. */
3934 DEFHOOK
3935 (builtin_setjmp_frame_value,
3936 "This target hook should return an rtx that is used to store\n\
3937 the address of the current frame into the built in @code{setjmp} buffer.\n\
3938 The default value, @code{virtual_stack_vars_rtx}, is correct for most\n\
3939 machines. One reason you may need to define this target hook is if\n\
3940 @code{hard_frame_pointer_rtx} is the appropriate value on your machine.",
3941 rtx, (void),
3942 default_builtin_setjmp_frame_value)
3944 /* This target hook should manipulate the outputs, inputs, constraints,
3945 and clobbers the port wishes for pre-processing the asm. */
3946 DEFHOOK
3947 (md_asm_adjust,
3948 "This target hook may add @dfn{clobbers} to @var{clobbers} and\n\
3949 @var{clobbered_regs} for any hard regs the port wishes to automatically\n\
3950 clobber for an asm. The @var{outputs} and @var{inputs} may be inspected\n\
3951 to avoid clobbering a register that is already used by the asm.\n\
3953 It may modify the @var{outputs}, @var{inputs}, and @var{constraints}\n\
3954 as necessary for other pre-processing. In this case the return value is\n\
3955 a sequence of insns to emit after the asm.",
3956 rtx_insn *,
3957 (vec<rtx>& outputs, vec<rtx>& inputs, vec<const char *>& constraints,
3958 vec<rtx>& clobbers, HARD_REG_SET& clobbered_regs),
3959 NULL)
3961 /* This target hook allows the backend to specify a calling convention
3962 in the debug information. This function actually returns an
3963 enum dwarf_calling_convention, but because of forward declarations
3964 and not wanting to include dwarf2.h everywhere target.h is included
3965 the function is being declared as an int. */
3966 DEFHOOK
3967 (dwarf_calling_convention,
3968 "Define this to enable the dwarf attribute @code{DW_AT_calling_convention} to\n\
3969 be emitted for each function. Instead of an integer return the enum\n\
3970 value for the @code{DW_CC_} tag.",
3971 int, (const_tree function),
3972 hook_int_const_tree_0)
3974 /* This target hook allows the backend to emit frame-related insns that
3975 contain UNSPECs or UNSPEC_VOLATILEs. The call frame debugging info
3976 engine will invoke it on insns of the form
3977 (set (reg) (unspec [...] UNSPEC_INDEX))
3979 (set (reg) (unspec_volatile [...] UNSPECV_INDEX))
3980 to let the backend emit the call frame instructions. */
3981 DEFHOOK
3982 (dwarf_handle_frame_unspec,
3983 "This target hook allows the backend to emit frame-related insns that\n\
3984 contain UNSPECs or UNSPEC_VOLATILEs. The DWARF 2 call frame debugging\n\
3985 info engine will invoke it on insns of the form\n\
3986 @smallexample\n\
3987 (set (reg) (unspec [@dots{}] UNSPEC_INDEX))\n\
3988 @end smallexample\n\
3989 and\n\
3990 @smallexample\n\
3991 (set (reg) (unspec_volatile [@dots{}] UNSPECV_INDEX)).\n\
3992 @end smallexample\n\
3993 to let the backend emit the call frame instructions. @var{label} is\n\
3994 the CFI label attached to the insn, @var{pattern} is the pattern of\n\
3995 the insn and @var{index} is @code{UNSPEC_INDEX} or @code{UNSPECV_INDEX}.",
3996 void, (const char *label, rtx pattern, int index), NULL)
3998 /* ??? Documenting this hook requires a GFDL license grant. */
3999 DEFHOOK_UNDOC
4000 (stdarg_optimize_hook,
4001 "Perform architecture specific checking of statements gimplified\
4002 from @code{VA_ARG_EXPR}. @var{stmt} is the statement. Returns true if\
4003 the statement doesn't need to be checked for @code{va_list} references.",
4004 bool, (struct stdarg_info *ai, const gimple *stmt), NULL)
4006 /* This target hook allows the operating system to override the DECL
4007 that represents the external variable that contains the stack
4008 protection guard variable. The type of this DECL is ptr_type_node. */
4009 DEFHOOK
4010 (stack_protect_guard,
4011 "This hook returns a @code{DECL} node for the external variable to use\n\
4012 for the stack protection guard. This variable is initialized by the\n\
4013 runtime to some random value and is used to initialize the guard value\n\
4014 that is placed at the top of the local stack frame. The type of this\n\
4015 variable must be @code{ptr_type_node}.\n\
4017 The default version of this hook creates a variable called\n\
4018 @samp{__stack_chk_guard}, which is normally defined in @file{libgcc2.c}.",
4019 tree, (void),
4020 default_stack_protect_guard)
4022 /* This target hook allows the operating system to override the CALL_EXPR
4023 that is invoked when a check vs the guard variable fails. */
4024 DEFHOOK
4025 (stack_protect_fail,
4026 "This hook returns a @code{CALL_EXPR} that alerts the runtime that the\n\
4027 stack protect guard variable has been modified. This expression should\n\
4028 involve a call to a @code{noreturn} function.\n\
4030 The default version of this hook invokes a function called\n\
4031 @samp{__stack_chk_fail}, taking no arguments. This function is\n\
4032 normally defined in @file{libgcc2.c}.",
4033 tree, (void),
4034 default_external_stack_protect_fail)
4036 /* This target hook allows the operating system to disable the default stack
4037 protector runtime support. */
4038 DEFHOOK
4039 (stack_protect_runtime_enabled_p,
4040 "Returns true if the target wants GCC's default stack protect runtime support,\
4041 otherwise return false. The default implementation always returns true.",
4042 bool, (void),
4043 hook_bool_void_true)
4045 DEFHOOK
4046 (can_use_doloop_p,
4047 "Return true if it is possible to use low-overhead loops (@code{doloop_end}\n\
4048 and @code{doloop_begin}) for a particular loop. @var{iterations} gives the\n\
4049 exact number of iterations, or 0 if not known. @var{iterations_max} gives\n\
4050 the maximum number of iterations, or 0 if not known. @var{loop_depth} is\n\
4051 the nesting depth of the loop, with 1 for innermost loops, 2 for loops that\n\
4052 contain innermost loops, and so on. @var{entered_at_top} is true if the\n\
4053 loop is only entered from the top.\n\
4055 This hook is only used if @code{doloop_end} is available. The default\n\
4056 implementation returns true. You can use @code{can_use_doloop_if_innermost}\n\
4057 if the loop must be the innermost, and if there are no other restrictions.",
4058 bool, (const widest_int &iterations, const widest_int &iterations_max,
4059 unsigned int loop_depth, bool entered_at_top),
4060 hook_bool_wint_wint_uint_bool_true)
4062 /* Returns NULL if target supports the insn within a doloop block,
4063 otherwise it returns an error message. */
4064 DEFHOOK
4065 (invalid_within_doloop,
4066 "\n\
4067 Take an instruction in @var{insn} and return NULL if it is valid within a\n\
4068 low-overhead loop, otherwise return a string explaining why doloop\n\
4069 could not be applied.\n\
4071 Many targets use special registers for low-overhead looping. For any\n\
4072 instruction that clobbers these this function should return a string indicating\n\
4073 the reason why the doloop could not be applied.\n\
4074 By default, the RTL loop optimizer does not use a present doloop pattern for\n\
4075 loops containing function calls or branch on table instructions.",
4076 const char *, (const rtx_insn *insn),
4077 default_invalid_within_doloop)
4079 /* Returns true for a legitimate combined insn. */
4080 DEFHOOK
4081 (legitimate_combined_insn,
4082 "Take an instruction in @var{insn} and return @code{false} if the instruction\
4083 is not appropriate as a combination of two or more instructions. The\
4084 default is to accept all instructions.",
4085 bool, (rtx_insn *insn),
4086 hook_bool_rtx_insn_true)
4088 DEFHOOK
4089 (valid_dllimport_attribute_p,
4090 "@var{decl} is a variable or function with @code{__attribute__((dllimport))}\
4091 specified. Use this hook if the target needs to add extra validation\
4092 checks to @code{handle_dll_attribute}.",
4093 bool, (const_tree decl),
4094 hook_bool_const_tree_true)
4096 /* If non-zero, align constant anchors in CSE to a multiple of this
4097 value. */
4098 DEFHOOKPOD
4099 (const_anchor,
4100 "On some architectures it can take multiple instructions to synthesize\n\
4101 a constant. If there is another constant already in a register that\n\
4102 is close enough in value then it is preferable that the new constant\n\
4103 is computed from this register using immediate addition or\n\
4104 subtraction. We accomplish this through CSE. Besides the value of\n\
4105 the constant we also add a lower and an upper constant anchor to the\n\
4106 available expressions. These are then queried when encountering new\n\
4107 constants. The anchors are computed by rounding the constant up and\n\
4108 down to a multiple of the value of @code{TARGET_CONST_ANCHOR}.\n\
4109 @code{TARGET_CONST_ANCHOR} should be the maximum positive value\n\
4110 accepted by immediate-add plus one. We currently assume that the\n\
4111 value of @code{TARGET_CONST_ANCHOR} is a power of 2. For example, on\n\
4112 MIPS, where add-immediate takes a 16-bit signed value,\n\
4113 @code{TARGET_CONST_ANCHOR} is set to @samp{0x8000}. The default value\n\
4114 is zero, which disables this optimization.",
4115 unsigned HOST_WIDE_INT, 0)
4117 /* Defines, which target-dependent bits (upper 16) are used by port */
4118 DEFHOOK
4119 (memmodel_check,
4120 "Validate target specific memory model mask bits. When NULL no target specific\n\
4121 memory model bits are allowed.",
4122 unsigned HOST_WIDE_INT, (unsigned HOST_WIDE_INT val), NULL)
4124 /* Defines an offset bitwise ored into shifted address to get corresponding
4125 Address Sanitizer shadow address, or -1 if Address Sanitizer is not
4126 supported by the target. */
4127 DEFHOOK
4128 (asan_shadow_offset,
4129 "Return the offset bitwise ored into shifted address to get corresponding\n\
4130 Address Sanitizer shadow memory address. NULL if Address Sanitizer is not\n\
4131 supported by the target.",
4132 unsigned HOST_WIDE_INT, (void),
4133 NULL)
4135 /* Functions relating to calls - argument passing, returns, etc. */
4136 /* Members of struct call have no special macro prefix. */
4137 HOOK_VECTOR (TARGET_CALLS, calls)
4139 DEFHOOK
4140 (promote_function_mode,
4141 "Like @code{PROMOTE_MODE}, but it is applied to outgoing function arguments or\n\
4142 function return values. The target hook should return the new mode\n\
4143 and possibly change @code{*@var{punsignedp}} if the promotion should\n\
4144 change signedness. This function is called only for scalar @emph{or\n\
4145 pointer} types.\n\
4147 @var{for_return} allows to distinguish the promotion of arguments and\n\
4148 return values. If it is @code{1}, a return value is being promoted and\n\
4149 @code{TARGET_FUNCTION_VALUE} must perform the same promotions done here.\n\
4150 If it is @code{2}, the returned mode should be that of the register in\n\
4151 which an incoming parameter is copied, or the outgoing result is computed;\n\
4152 then the hook should return the same mode as @code{promote_mode}, though\n\
4153 the signedness may be different.\n\
4155 @var{type} can be NULL when promoting function arguments of libcalls.\n\
4157 The default is to not promote arguments and return values. You can\n\
4158 also define the hook to @code{default_promote_function_mode_always_promote}\n\
4159 if you would like to apply the same rules given by @code{PROMOTE_MODE}.",
4160 machine_mode, (const_tree type, machine_mode mode, int *punsignedp,
4161 const_tree funtype, int for_return),
4162 default_promote_function_mode)
4164 DEFHOOK
4165 (promote_prototypes,
4166 "This target hook returns @code{true} if an argument declared in a\n\
4167 prototype as an integral type smaller than @code{int} should actually be\n\
4168 passed as an @code{int}. In addition to avoiding errors in certain\n\
4169 cases of mismatch, it also makes for better code on certain machines.\n\
4170 The default is to not promote prototypes.",
4171 bool, (const_tree fntype),
4172 hook_bool_const_tree_false)
4174 DEFHOOK
4175 (struct_value_rtx,
4176 "This target hook should return the location of the structure value\n\
4177 address (normally a @code{mem} or @code{reg}), or 0 if the address is\n\
4178 passed as an ``invisible'' first argument. Note that @var{fndecl} may\n\
4179 be @code{NULL}, for libcalls. You do not need to define this target\n\
4180 hook if the address is always passed as an ``invisible'' first\n\
4181 argument.\n\
4183 On some architectures the place where the structure value address\n\
4184 is found by the called function is not the same place that the\n\
4185 caller put it. This can be due to register windows, or it could\n\
4186 be because the function prologue moves it to a different place.\n\
4187 @var{incoming} is @code{1} or @code{2} when the location is needed in\n\
4188 the context of the called function, and @code{0} in the context of\n\
4189 the caller.\n\
4191 If @var{incoming} is nonzero and the address is to be found on the\n\
4192 stack, return a @code{mem} which refers to the frame pointer. If\n\
4193 @var{incoming} is @code{2}, the result is being used to fetch the\n\
4194 structure value address at the beginning of a function. If you need\n\
4195 to emit adjusting code, you should do it at this point.",
4196 rtx, (tree fndecl, int incoming),
4197 hook_rtx_tree_int_null)
4199 DEFHOOKPOD
4200 (omit_struct_return_reg,
4201 "Normally, when a function returns a structure by memory, the address\n\
4202 is passed as an invisible pointer argument, but the compiler also\n\
4203 arranges to return the address from the function like it would a normal\n\
4204 pointer return value. Define this to true if that behavior is\n\
4205 undesirable on your target.",
4206 bool, false)
4208 DEFHOOK
4209 (return_in_memory,
4210 "This target hook should return a nonzero value to say to return the\n\
4211 function value in memory, just as large structures are always returned.\n\
4212 Here @var{type} will be the data type of the value, and @var{fntype}\n\
4213 will be the type of the function doing the returning, or @code{NULL} for\n\
4214 libcalls.\n\
4216 Note that values of mode @code{BLKmode} must be explicitly handled\n\
4217 by this function. Also, the option @option{-fpcc-struct-return}\n\
4218 takes effect regardless of this macro. On most systems, it is\n\
4219 possible to leave the hook undefined; this causes a default\n\
4220 definition to be used, whose value is the constant 1 for @code{BLKmode}\n\
4221 values, and 0 otherwise.\n\
4223 Do not use this hook to indicate that structures and unions should always\n\
4224 be returned in memory. You should instead use @code{DEFAULT_PCC_STRUCT_RETURN}\n\
4225 to indicate this.",
4226 bool, (const_tree type, const_tree fntype),
4227 default_return_in_memory)
4229 DEFHOOK
4230 (return_in_msb,
4231 "This hook should return true if values of type @var{type} are returned\n\
4232 at the most significant end of a register (in other words, if they are\n\
4233 padded at the least significant end). You can assume that @var{type}\n\
4234 is returned in a register; the caller is required to check this.\n\
4236 Note that the register provided by @code{TARGET_FUNCTION_VALUE} must\n\
4237 be able to hold the complete return value. For example, if a 1-, 2-\n\
4238 or 3-byte structure is returned at the most significant end of a\n\
4239 4-byte register, @code{TARGET_FUNCTION_VALUE} should provide an\n\
4240 @code{SImode} rtx.",
4241 bool, (const_tree type),
4242 hook_bool_const_tree_false)
4244 /* Return true if a parameter must be passed by reference. TYPE may
4245 be null if this is a libcall. CA may be null if this query is
4246 from __builtin_va_arg. */
4247 DEFHOOK
4248 (pass_by_reference,
4249 "This target hook should return @code{true} if an argument at the\n\
4250 position indicated by @var{cum} should be passed by reference. This\n\
4251 predicate is queried after target independent reasons for being\n\
4252 passed by reference, such as @code{TREE_ADDRESSABLE (type)}.\n\
4254 If the hook returns true, a copy of that argument is made in memory and a\n\
4255 pointer to the argument is passed instead of the argument itself.\n\
4256 The pointer is passed in whatever way is appropriate for passing a pointer\n\
4257 to that type.",
4258 bool,
4259 (cumulative_args_t cum, machine_mode mode, const_tree type, bool named),
4260 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false)
4262 DEFHOOK
4263 (expand_builtin_saveregs,
4264 "If defined, this hook produces the machine-specific code for a call to\n\
4265 @code{__builtin_saveregs}. This code will be moved to the very\n\
4266 beginning of the function, before any parameter access are made. The\n\
4267 return value of this function should be an RTX that contains the value\n\
4268 to use as the return of @code{__builtin_saveregs}.",
4269 rtx, (void),
4270 default_expand_builtin_saveregs)
4272 /* Returns pretend_argument_size. */
4273 DEFHOOK
4274 (setup_incoming_varargs,
4275 "This target hook offers an alternative to using\n\
4276 @code{__builtin_saveregs} and defining the hook\n\
4277 @code{TARGET_EXPAND_BUILTIN_SAVEREGS}. Use it to store the anonymous\n\
4278 register arguments into the stack so that all the arguments appear to\n\
4279 have been passed consecutively on the stack. Once this is done, you can\n\
4280 use the standard implementation of varargs that works for machines that\n\
4281 pass all their arguments on the stack.\n\
4283 The argument @var{args_so_far} points to the @code{CUMULATIVE_ARGS} data\n\
4284 structure, containing the values that are obtained after processing the\n\
4285 named arguments. The arguments @var{mode} and @var{type} describe the\n\
4286 last named argument---its machine mode and its data type as a tree node.\n\
4288 The target hook should do two things: first, push onto the stack all the\n\
4289 argument registers @emph{not} used for the named arguments, and second,\n\
4290 store the size of the data thus pushed into the @code{int}-valued\n\
4291 variable pointed to by @var{pretend_args_size}. The value that you\n\
4292 store here will serve as additional offset for setting up the stack\n\
4293 frame.\n\
4295 Because you must generate code to push the anonymous arguments at\n\
4296 compile time without knowing their data types,\n\
4297 @code{TARGET_SETUP_INCOMING_VARARGS} is only useful on machines that\n\
4298 have just a single category of argument register and use it uniformly\n\
4299 for all data types.\n\
4301 If the argument @var{second_time} is nonzero, it means that the\n\
4302 arguments of the function are being analyzed for the second time. This\n\
4303 happens for an inline function, which is not actually compiled until the\n\
4304 end of the source file. The hook @code{TARGET_SETUP_INCOMING_VARARGS} should\n\
4305 not generate any instructions in this case.",
4306 void, (cumulative_args_t args_so_far, machine_mode mode, tree type,
4307 int *pretend_args_size, int second_time),
4308 default_setup_incoming_varargs)
4310 DEFHOOK
4311 (load_bounds_for_arg,
4312 "This hook is used by expand pass to emit insn to load bounds of\n\
4313 @var{arg} passed in @var{slot}. Expand pass uses this hook in case\n\
4314 bounds of @var{arg} are not passed in register. If @var{slot} is a\n\
4315 memory, then bounds are loaded as for regular pointer loaded from\n\
4316 memory. If @var{slot} is not a memory then @var{slot_no} is an integer\n\
4317 constant holding number of the target dependent special slot which\n\
4318 should be used to obtain bounds. Hook returns RTX holding loaded bounds.",
4319 rtx, (rtx slot, rtx arg, rtx slot_no),
4320 default_load_bounds_for_arg)
4322 DEFHOOK
4323 (store_bounds_for_arg,
4324 "This hook is used by expand pass to emit insns to store @var{bounds} of\n\
4325 @var{arg} passed in @var{slot}. Expand pass uses this hook in case\n\
4326 @var{bounds} of @var{arg} are not passed in register. If @var{slot} is a\n\
4327 memory, then @var{bounds} are stored as for regular pointer stored in\n\
4328 memory. If @var{slot} is not a memory then @var{slot_no} is an integer\n\
4329 constant holding number of the target dependent special slot which\n\
4330 should be used to store @var{bounds}.",
4331 void, (rtx arg, rtx slot, rtx bounds, rtx slot_no),
4332 default_store_bounds_for_arg)
4334 DEFHOOK
4335 (load_returned_bounds,
4336 "This hook is used by expand pass to emit insn to load bounds\n\
4337 returned by function call in @var{slot}. Hook returns RTX holding\n\
4338 loaded bounds.",
4339 rtx, (rtx slot),
4340 default_load_returned_bounds)
4342 DEFHOOK
4343 (store_returned_bounds,
4344 "This hook is used by expand pass to emit insn to store @var{bounds}\n\
4345 returned by function call into @var{slot}.",
4346 void, (rtx slot, rtx bounds),
4347 default_store_returned_bounds)
4349 DEFHOOK
4350 (setup_incoming_vararg_bounds,
4351 "Use it to store bounds for anonymous register arguments stored\n\
4352 into the stack. Arguments meaning is similar to\n\
4353 @code{TARGET_SETUP_INCOMING_VARARGS}.",
4354 void, (cumulative_args_t args_so_far, enum machine_mode mode, tree type,
4355 int *pretend_args_size, int second_time),
4356 default_setup_incoming_vararg_bounds)
4358 DEFHOOK
4359 (call_args,
4360 "While generating RTL for a function call, this target hook is invoked once\n\
4361 for each argument passed to the function, either a register returned by\n\
4362 @code{TARGET_FUNCTION_ARG} or a memory location. It is called just\n\
4363 before the point where argument registers are stored. The type of the\n\
4364 function to be called is also passed as the second argument; it is\n\
4365 @code{NULL_TREE} for libcalls. The @code{TARGET_END_CALL_ARGS} hook is\n\
4366 invoked just after the code to copy the return reg has been emitted.\n\
4367 This functionality can be used to perform special setup of call argument\n\
4368 registers if a target needs it.\n\
4369 For functions without arguments, the hook is called once with @code{pc_rtx}\n\
4370 passed instead of an argument register.\n\
4371 Most ports do not need to implement anything for this hook.",
4372 void, (rtx, tree),
4373 hook_void_rtx_tree)
4375 DEFHOOK
4376 (end_call_args,
4377 "This target hook is invoked while generating RTL for a function call,\n\
4378 just after the point where the return reg is copied into a pseudo. It\n\
4379 signals that all the call argument and return registers for the just\n\
4380 emitted call are now no longer in use.\n\
4381 Most ports do not need to implement anything for this hook.",
4382 void, (void),
4383 hook_void_void)
4385 DEFHOOK
4386 (strict_argument_naming,
4387 "Define this hook to return @code{true} if the location where a function\n\
4388 argument is passed depends on whether or not it is a named argument.\n\
4390 This hook controls how the @var{named} argument to @code{TARGET_FUNCTION_ARG}\n\
4391 is set for varargs and stdarg functions. If this hook returns\n\
4392 @code{true}, the @var{named} argument is always true for named\n\
4393 arguments, and false for unnamed arguments. If it returns @code{false},\n\
4394 but @code{TARGET_PRETEND_OUTGOING_VARARGS_NAMED} returns @code{true},\n\
4395 then all arguments are treated as named. Otherwise, all named arguments\n\
4396 except the last are treated as named.\n\
4398 You need not define this hook if it always returns @code{false}.",
4399 bool, (cumulative_args_t ca),
4400 hook_bool_CUMULATIVE_ARGS_false)
4402 /* Returns true if we should use
4403 targetm.calls.setup_incoming_varargs() and/or
4404 targetm.calls.strict_argument_naming(). */
4405 DEFHOOK
4406 (pretend_outgoing_varargs_named,
4407 "If you need to conditionally change ABIs so that one works with\n\
4408 @code{TARGET_SETUP_INCOMING_VARARGS}, but the other works like neither\n\
4409 @code{TARGET_SETUP_INCOMING_VARARGS} nor @code{TARGET_STRICT_ARGUMENT_NAMING} was\n\
4410 defined, then define this hook to return @code{true} if\n\
4411 @code{TARGET_SETUP_INCOMING_VARARGS} is used, @code{false} otherwise.\n\
4412 Otherwise, you should not define this hook.",
4413 bool, (cumulative_args_t ca),
4414 default_pretend_outgoing_varargs_named)
4416 /* Given a complex type T, return true if a parameter of type T
4417 should be passed as two scalars. */
4418 DEFHOOK
4419 (split_complex_arg,
4420 "This hook should return true if parameter of type @var{type} are passed\n\
4421 as two scalar parameters. By default, GCC will attempt to pack complex\n\
4422 arguments into the target's word size. Some ABIs require complex arguments\n\
4423 to be split and treated as their individual components. For example, on\n\
4424 AIX64, complex floats should be passed in a pair of floating point\n\
4425 registers, even though a complex float would fit in one 64-bit floating\n\
4426 point register.\n\
4428 The default value of this hook is @code{NULL}, which is treated as always\n\
4429 false.",
4430 bool, (const_tree type), NULL)
4432 /* Return true if type T, mode MODE, may not be passed in registers,
4433 but must be passed on the stack. */
4434 /* ??? This predicate should be applied strictly after pass-by-reference.
4435 Need audit to verify that this is the case. */
4436 DEFHOOK
4437 (must_pass_in_stack,
4438 "This target hook should return @code{true} if we should not pass @var{type}\n\
4439 solely in registers. The file @file{expr.h} defines a\n\
4440 definition that is usually appropriate, refer to @file{expr.h} for additional\n\
4441 documentation.",
4442 bool, (machine_mode mode, const_tree type),
4443 must_pass_in_stack_var_size_or_pad)
4445 /* Return true if type TYPE, mode MODE, which is passed by reference,
4446 should have the object copy generated by the callee rather than
4447 the caller. It is never called for TYPE requiring constructors. */
4448 DEFHOOK
4449 (callee_copies,
4450 "The function argument described by the parameters to this hook is\n\
4451 known to be passed by reference. The hook should return true if the\n\
4452 function argument should be copied by the callee instead of copied\n\
4453 by the caller.\n\
4455 For any argument for which the hook returns true, if it can be\n\
4456 determined that the argument is not modified, then a copy need\n\
4457 not be generated.\n\
4459 The default version of this hook always returns false.",
4460 bool,
4461 (cumulative_args_t cum, machine_mode mode, const_tree type, bool named),
4462 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false)
4464 /* Return zero for arguments passed entirely on the stack or entirely
4465 in registers. If passed in both, return the number of bytes passed
4466 in registers; the balance is therefore passed on the stack. */
4467 DEFHOOK
4468 (arg_partial_bytes,
4469 "This target hook returns the number of bytes at the beginning of an\n\
4470 argument that must be put in registers. The value must be zero for\n\
4471 arguments that are passed entirely in registers or that are entirely\n\
4472 pushed on the stack.\n\
4474 On some machines, certain arguments must be passed partially in\n\
4475 registers and partially in memory. On these machines, typically the\n\
4476 first few words of arguments are passed in registers, and the rest\n\
4477 on the stack. If a multi-word argument (a @code{double} or a\n\
4478 structure) crosses that boundary, its first few words must be passed\n\
4479 in registers and the rest must be pushed. This macro tells the\n\
4480 compiler when this occurs, and how many bytes should go in registers.\n\
4482 @code{TARGET_FUNCTION_ARG} for these arguments should return the first\n\
4483 register to be used by the caller for this argument; likewise\n\
4484 @code{TARGET_FUNCTION_INCOMING_ARG}, for the called function.",
4485 int, (cumulative_args_t cum, machine_mode mode, tree type, bool named),
4486 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0)
4488 /* Update the state in CA to advance past an argument in the
4489 argument list. The values MODE, TYPE, and NAMED describe that
4490 argument. */
4491 DEFHOOK
4492 (function_arg_advance,
4493 "This hook updates the summarizer variable pointed to by @var{ca} to\n\
4494 advance past an argument in the argument list. The values @var{mode},\n\
4495 @var{type} and @var{named} describe that argument. Once this is done,\n\
4496 the variable @var{cum} is suitable for analyzing the @emph{following}\n\
4497 argument with @code{TARGET_FUNCTION_ARG}, etc.\n\
4499 This hook need not do anything if the argument in question was passed\n\
4500 on the stack. The compiler knows how to track the amount of stack space\n\
4501 used for arguments without any special help.",
4502 void,
4503 (cumulative_args_t ca, machine_mode mode, const_tree type, bool named),
4504 default_function_arg_advance)
4506 /* Return zero if the argument described by the state of CA should
4507 be placed on a stack, or a hard register in which to store the
4508 argument. The values MODE, TYPE, and NAMED describe that
4509 argument. */
4510 DEFHOOK
4511 (function_arg,
4512 "Return an RTX indicating whether a function argument is passed in a\n\
4513 register and if so, which register.\n\
4515 The arguments are @var{ca}, which summarizes all the previous\n\
4516 arguments; @var{mode}, the machine mode of the argument; @var{type},\n\
4517 the data type of the argument as a tree node or 0 if that is not known\n\
4518 (which happens for C support library functions); and @var{named},\n\
4519 which is @code{true} for an ordinary argument and @code{false} for\n\
4520 nameless arguments that correspond to @samp{@dots{}} in the called\n\
4521 function's prototype. @var{type} can be an incomplete type if a\n\
4522 syntax error has previously occurred.\n\
4524 The return value is usually either a @code{reg} RTX for the hard\n\
4525 register in which to pass the argument, or zero to pass the argument\n\
4526 on the stack.\n\
4528 The return value can be a @code{const_int} which means argument is\n\
4529 passed in a target specific slot with specified number. Target hooks\n\
4530 should be used to store or load argument in such case. See\n\
4531 @code{TARGET_STORE_BOUNDS_FOR_ARG} and @code{TARGET_LOAD_BOUNDS_FOR_ARG}\n\
4532 for more information.\n\
4534 The value of the expression can also be a @code{parallel} RTX@. This is\n\
4535 used when an argument is passed in multiple locations. The mode of the\n\
4536 @code{parallel} should be the mode of the entire argument. The\n\
4537 @code{parallel} holds any number of @code{expr_list} pairs; each one\n\
4538 describes where part of the argument is passed. In each\n\
4539 @code{expr_list} the first operand must be a @code{reg} RTX for the hard\n\
4540 register in which to pass this part of the argument, and the mode of the\n\
4541 register RTX indicates how large this part of the argument is. The\n\
4542 second operand of the @code{expr_list} is a @code{const_int} which gives\n\
4543 the offset in bytes into the entire argument of where this part starts.\n\
4544 As a special exception the first @code{expr_list} in the @code{parallel}\n\
4545 RTX may have a first operand of zero. This indicates that the entire\n\
4546 argument is also stored on the stack.\n\
4548 The last time this hook is called, it is called with @code{MODE ==\n\
4549 VOIDmode}, and its result is passed to the @code{call} or @code{call_value}\n\
4550 pattern as operands 2 and 3 respectively.\n\
4552 @cindex @file{stdarg.h} and register arguments\n\
4553 The usual way to make the ISO library @file{stdarg.h} work on a\n\
4554 machine where some arguments are usually passed in registers, is to\n\
4555 cause nameless arguments to be passed on the stack instead. This is\n\
4556 done by making @code{TARGET_FUNCTION_ARG} return 0 whenever\n\
4557 @var{named} is @code{false}.\n\
4559 @cindex @code{TARGET_MUST_PASS_IN_STACK}, and @code{TARGET_FUNCTION_ARG}\n\
4560 @cindex @code{REG_PARM_STACK_SPACE}, and @code{TARGET_FUNCTION_ARG}\n\
4561 You may use the hook @code{targetm.calls.must_pass_in_stack}\n\
4562 in the definition of this macro to determine if this argument is of a\n\
4563 type that must be passed in the stack. If @code{REG_PARM_STACK_SPACE}\n\
4564 is not defined and @code{TARGET_FUNCTION_ARG} returns nonzero for such an\n\
4565 argument, the compiler will abort. If @code{REG_PARM_STACK_SPACE} is\n\
4566 defined, the argument will be computed in the stack and then loaded into\n\
4567 a register.",
4568 rtx, (cumulative_args_t ca, machine_mode mode, const_tree type,
4569 bool named),
4570 default_function_arg)
4572 DEFHOOK
4573 (function_incoming_arg,
4574 "Define this hook if the caller and callee on the target have different\n\
4575 views of where arguments are passed. Also define this hook if there are\n\
4576 functions that are never directly called, but are invoked by the hardware\n\
4577 and which have nonstandard calling conventions.\n\
4579 In this case @code{TARGET_FUNCTION_ARG} computes the register in\n\
4580 which the caller passes the value, and\n\
4581 @code{TARGET_FUNCTION_INCOMING_ARG} should be defined in a similar\n\
4582 fashion to tell the function being called where the arguments will\n\
4583 arrive.\n\
4585 @code{TARGET_FUNCTION_INCOMING_ARG} can also return arbitrary address\n\
4586 computation using hard register, which can be forced into a register,\n\
4587 so that it can be used to pass special arguments.\n\
4589 If @code{TARGET_FUNCTION_INCOMING_ARG} is not defined,\n\
4590 @code{TARGET_FUNCTION_ARG} serves both purposes.",
4591 rtx, (cumulative_args_t ca, machine_mode mode, const_tree type,
4592 bool named),
4593 default_function_incoming_arg)
4595 DEFHOOK
4596 (function_arg_boundary,
4597 "This hook returns the alignment boundary, in bits, of an argument\n\
4598 with the specified mode and type. The default hook returns\n\
4599 @code{PARM_BOUNDARY} for all arguments.",
4600 unsigned int, (machine_mode mode, const_tree type),
4601 default_function_arg_boundary)
4603 DEFHOOK
4604 (function_arg_round_boundary,
4605 "Normally, the size of an argument is rounded up to @code{PARM_BOUNDARY},\n\
4606 which is the default value for this hook. You can define this hook to\n\
4607 return a different value if an argument size must be rounded to a larger\n\
4608 value.",
4609 unsigned int, (machine_mode mode, const_tree type),
4610 default_function_arg_round_boundary)
4612 /* Return the diagnostic message string if function without a prototype
4613 is not allowed for this 'val' argument; NULL otherwise. */
4614 DEFHOOK
4615 (invalid_arg_for_unprototyped_fn,
4616 "If defined, this macro returns the diagnostic message when it is\n\
4617 illegal to pass argument @var{val} to function @var{funcdecl}\n\
4618 with prototype @var{typelist}.",
4619 const char *, (const_tree typelist, const_tree funcdecl, const_tree val),
4620 hook_invalid_arg_for_unprototyped_fn)
4622 /* Return an rtx for the return value location of the function
4623 specified by FN_DECL_OR_TYPE with a return type of RET_TYPE. */
4624 DEFHOOK
4625 (function_value,
4626 "\n\
4627 Define this to return an RTX representing the place where a function\n\
4628 returns or receives a value of data type @var{ret_type}, a tree node\n\
4629 representing a data type. @var{fn_decl_or_type} is a tree node\n\
4630 representing @code{FUNCTION_DECL} or @code{FUNCTION_TYPE} of a\n\
4631 function being called. If @var{outgoing} is false, the hook should\n\
4632 compute the register in which the caller will see the return value.\n\
4633 Otherwise, the hook should return an RTX representing the place where\n\
4634 a function returns a value.\n\
4636 On many machines, only @code{TYPE_MODE (@var{ret_type})} is relevant.\n\
4637 (Actually, on most machines, scalar values are returned in the same\n\
4638 place regardless of mode.) The value of the expression is usually a\n\
4639 @code{reg} RTX for the hard register where the return value is stored.\n\
4640 The value can also be a @code{parallel} RTX, if the return value is in\n\
4641 multiple places. See @code{TARGET_FUNCTION_ARG} for an explanation of the\n\
4642 @code{parallel} form. Note that the callee will populate every\n\
4643 location specified in the @code{parallel}, but if the first element of\n\
4644 the @code{parallel} contains the whole return value, callers will use\n\
4645 that element as the canonical location and ignore the others. The m68k\n\
4646 port uses this type of @code{parallel} to return pointers in both\n\
4647 @samp{%a0} (the canonical location) and @samp{%d0}.\n\
4649 If @code{TARGET_PROMOTE_FUNCTION_RETURN} returns true, you must apply\n\
4650 the same promotion rules specified in @code{PROMOTE_MODE} if\n\
4651 @var{valtype} is a scalar type.\n\
4653 If the precise function being called is known, @var{func} is a tree\n\
4654 node (@code{FUNCTION_DECL}) for it; otherwise, @var{func} is a null\n\
4655 pointer. This makes it possible to use a different value-returning\n\
4656 convention for specific functions when all their calls are\n\
4657 known.\n\
4659 Some target machines have ``register windows'' so that the register in\n\
4660 which a function returns its value is not the same as the one in which\n\
4661 the caller sees the value. For such machines, you should return\n\
4662 different RTX depending on @var{outgoing}.\n\
4664 @code{TARGET_FUNCTION_VALUE} is not used for return values with\n\
4665 aggregate data types, because these are returned in another way. See\n\
4666 @code{TARGET_STRUCT_VALUE_RTX} and related macros, below.",
4667 rtx, (const_tree ret_type, const_tree fn_decl_or_type, bool outgoing),
4668 default_function_value)
4670 /* Return the rtx for bounds of returned pointer. */
4671 DEFHOOK
4672 (chkp_function_value_bounds,
4673 "Define this to return an RTX representing the place where a function\n\
4674 returns bounds for returned pointers. Arguments meaning is similar to\n\
4675 @code{TARGET_FUNCTION_VALUE}.",
4676 rtx, (const_tree ret_type, const_tree fn_decl_or_type, bool outgoing),
4677 default_chkp_function_value_bounds)
4679 /* Return the rtx for the result of a libcall of mode MODE,
4680 calling the function FN_NAME. */
4681 DEFHOOK
4682 (libcall_value,
4683 "Define this hook if the back-end needs to know the name of the libcall\n\
4684 function in order to determine where the result should be returned.\n\
4686 The mode of the result is given by @var{mode} and the name of the called\n\
4687 library function is given by @var{fun}. The hook should return an RTX\n\
4688 representing the place where the library function result will be returned.\n\
4690 If this hook is not defined, then LIBCALL_VALUE will be used.",
4691 rtx, (machine_mode mode, const_rtx fun),
4692 default_libcall_value)
4694 /* Return true if REGNO is a possible register number for
4695 a function value as seen by the caller. */
4696 DEFHOOK
4697 (function_value_regno_p,
4698 "A target hook that return @code{true} if @var{regno} is the number of a hard\n\
4699 register in which the values of called function may come back.\n\
4701 A register whose use for returning values is limited to serving as the\n\
4702 second of a pair (for a value of type @code{double}, say) need not be\n\
4703 recognized by this target hook.\n\
4705 If the machine has register windows, so that the caller and the called\n\
4706 function use different registers for the return value, this target hook\n\
4707 should recognize only the caller's register numbers.\n\
4709 If this hook is not defined, then FUNCTION_VALUE_REGNO_P will be used.",
4710 bool, (const unsigned int regno),
4711 default_function_value_regno_p)
4713 /* ??? Documenting this hook requires a GFDL license grant. */
4714 DEFHOOK_UNDOC
4715 (internal_arg_pointer,
4716 "Return an rtx for the argument pointer incoming to the\
4717 current function.",
4718 rtx, (void),
4719 default_internal_arg_pointer)
4721 /* Update the current function stack boundary if needed. */
4722 DEFHOOK
4723 (update_stack_boundary,
4724 "Define this macro to update the current function stack boundary if\n\
4725 necessary.",
4726 void, (void), NULL)
4728 /* Handle stack alignment and return an rtx for Dynamic Realign
4729 Argument Pointer if necessary. */
4730 DEFHOOK
4731 (get_drap_rtx,
4732 "This hook should return an rtx for Dynamic Realign Argument Pointer (DRAP) if a\n\
4733 different argument pointer register is needed to access the function's\n\
4734 argument list due to stack realignment. Return @code{NULL} if no DRAP\n\
4735 is needed.",
4736 rtx, (void), NULL)
4738 /* Return true if all function parameters should be spilled to the
4739 stack. */
4740 DEFHOOK
4741 (allocate_stack_slots_for_args,
4742 "When optimization is disabled, this hook indicates whether or not\n\
4743 arguments should be allocated to stack slots. Normally, GCC allocates\n\
4744 stacks slots for arguments when not optimizing in order to make\n\
4745 debugging easier. However, when a function is declared with\n\
4746 @code{__attribute__((naked))}, there is no stack frame, and the compiler\n\
4747 cannot safely move arguments from the registers in which they are passed\n\
4748 to the stack. Therefore, this hook should return true in general, but\n\
4749 false for naked functions. The default implementation always returns true.",
4750 bool, (void),
4751 hook_bool_void_true)
4753 /* Return an rtx for the static chain for FNDECL_OR_TYPE. If INCOMING_P
4754 is true, then it should be for the callee; otherwise for the caller. */
4755 DEFHOOK
4756 (static_chain,
4757 "This hook replaces the use of @code{STATIC_CHAIN_REGNUM} et al for\n\
4758 targets that may use different static chain locations for different\n\
4759 nested functions. This may be required if the target has function\n\
4760 attributes that affect the calling conventions of the function and\n\
4761 those calling conventions use different static chain locations.\n\
4763 The default version of this hook uses @code{STATIC_CHAIN_REGNUM} et al.\n\
4765 If the static chain is passed in memory, this hook should be used to\n\
4766 provide rtx giving @code{mem} expressions that denote where they are stored.\n\
4767 Often the @code{mem} expression as seen by the caller will be at an offset\n\
4768 from the stack pointer and the @code{mem} expression as seen by the callee\n\
4769 will be at an offset from the frame pointer.\n\
4770 @findex stack_pointer_rtx\n\
4771 @findex frame_pointer_rtx\n\
4772 @findex arg_pointer_rtx\n\
4773 The variables @code{stack_pointer_rtx}, @code{frame_pointer_rtx}, and\n\
4774 @code{arg_pointer_rtx} will have been initialized and should be used\n\
4775 to refer to those items.",
4776 rtx, (const_tree fndecl_or_type, bool incoming_p),
4777 default_static_chain)
4779 /* Fill in the trampoline at MEM with a call to FNDECL and a
4780 static chain value of CHAIN. */
4781 DEFHOOK
4782 (trampoline_init,
4783 "This hook is called to initialize a trampoline.\n\
4784 @var{m_tramp} is an RTX for the memory block for the trampoline; @var{fndecl}\n\
4785 is the @code{FUNCTION_DECL} for the nested function; @var{static_chain} is an\n\
4786 RTX for the static chain value that should be passed to the function\n\
4787 when it is called.\n\
4789 If the target defines @code{TARGET_ASM_TRAMPOLINE_TEMPLATE}, then the\n\
4790 first thing this hook should do is emit a block move into @var{m_tramp}\n\
4791 from the memory block returned by @code{assemble_trampoline_template}.\n\
4792 Note that the block move need only cover the constant parts of the\n\
4793 trampoline. If the target isolates the variable parts of the trampoline\n\
4794 to the end, not all @code{TRAMPOLINE_SIZE} bytes need be copied.\n\
4796 If the target requires any other actions, such as flushing caches or\n\
4797 enabling stack execution, these actions should be performed after\n\
4798 initializing the trampoline proper.",
4799 void, (rtx m_tramp, tree fndecl, rtx static_chain),
4800 default_trampoline_init)
4802 /* Adjust the address of the trampoline in a target-specific way. */
4803 DEFHOOK
4804 (trampoline_adjust_address,
4805 "This hook should perform any machine-specific adjustment in\n\
4806 the address of the trampoline. Its argument contains the address of the\n\
4807 memory block that was passed to @code{TARGET_TRAMPOLINE_INIT}. In case\n\
4808 the address to be used for a function call should be different from the\n\
4809 address at which the template was stored, the different address should\n\
4810 be returned; otherwise @var{addr} should be returned unchanged.\n\
4811 If this hook is not defined, @var{addr} will be used for function calls.",
4812 rtx, (rtx addr), NULL)
4814 DEFHOOKPOD
4815 (custom_function_descriptors,
4816 "This hook should be defined to a power of 2 if the target will benefit\n\
4817 from the use of custom descriptors for nested functions instead of the\n\
4818 standard trampolines. Such descriptors are created at run time on the\n\
4819 stack and made up of data only, but they are non-standard so the generated\n\
4820 code must be prepared to deal with them. This hook should be defined to 0\n\
4821 if the target uses function descriptors for its standard calling sequence,\n\
4822 like for example HP-PA or IA-64. Using descriptors for nested functions\n\
4823 eliminates the need for trampolines that reside on the stack and require\n\
4824 it to be made executable.\n\
4826 The value of the macro is used to parameterize the run-time identification\n\
4827 scheme implemented to distinguish descriptors from function addresses: it\n\
4828 gives the number of bytes by which their address is misaligned compared\n\
4829 with function addresses. The value of 1 will generally work, unless it is\n\
4830 already reserved by the target for another purpose, like for example on ARM.",\
4831 int, -1)
4833 /* Return the number of bytes of its own arguments that a function
4834 pops on returning, or 0 if the function pops no arguments and the
4835 caller must therefore pop them all after the function returns. */
4836 /* ??? tm.texi has no types for the parameters. */
4837 DEFHOOK
4838 (return_pops_args,
4839 "This target hook returns the number of bytes of its own arguments that\n\
4840 a function pops on returning, or 0 if the function pops no arguments\n\
4841 and the caller must therefore pop them all after the function returns.\n\
4843 @var{fundecl} is a C variable whose value is a tree node that describes\n\
4844 the function in question. Normally it is a node of type\n\
4845 @code{FUNCTION_DECL} that describes the declaration of the function.\n\
4846 From this you can obtain the @code{DECL_ATTRIBUTES} of the function.\n\
4848 @var{funtype} is a C variable whose value is a tree node that\n\
4849 describes the function in question. Normally it is a node of type\n\
4850 @code{FUNCTION_TYPE} that describes the data type of the function.\n\
4851 From this it is possible to obtain the data types of the value and\n\
4852 arguments (if known).\n\
4854 When a call to a library function is being considered, @var{fundecl}\n\
4855 will contain an identifier node for the library function. Thus, if\n\
4856 you need to distinguish among various library functions, you can do so\n\
4857 by their names. Note that ``library function'' in this context means\n\
4858 a function used to perform arithmetic, whose name is known specially\n\
4859 in the compiler and was not mentioned in the C code being compiled.\n\
4861 @var{size} is the number of bytes of arguments passed on the\n\
4862 stack. If a variable number of bytes is passed, it is zero, and\n\
4863 argument popping will always be the responsibility of the calling function.\n\
4865 On the VAX, all functions always pop their arguments, so the definition\n\
4866 of this macro is @var{size}. On the 68000, using the standard\n\
4867 calling convention, no functions pop their arguments, so the value of\n\
4868 the macro is always 0 in this case. But an alternative calling\n\
4869 convention is available in which functions that take a fixed number of\n\
4870 arguments pop them but other functions (such as @code{printf}) pop\n\
4871 nothing (the caller pops all). When this convention is in use,\n\
4872 @var{funtype} is examined to determine whether a function takes a fixed\n\
4873 number of arguments.",
4874 int, (tree fundecl, tree funtype, int size),
4875 default_return_pops_args)
4877 /* Return a mode wide enough to copy any function value that might be
4878 returned. */
4879 DEFHOOK
4880 (get_raw_result_mode,
4881 "This target hook returns the mode to be used when accessing raw return\
4882 registers in @code{__builtin_return}. Define this macro if the value\
4883 in @var{reg_raw_mode} is not correct.",
4884 machine_mode, (int regno),
4885 default_get_reg_raw_mode)
4887 /* Return a mode wide enough to copy any argument value that might be
4888 passed. */
4889 DEFHOOK
4890 (get_raw_arg_mode,
4891 "This target hook returns the mode to be used when accessing raw argument\
4892 registers in @code{__builtin_apply_args}. Define this macro if the value\
4893 in @var{reg_raw_mode} is not correct.",
4894 machine_mode, (int regno),
4895 default_get_reg_raw_mode)
4897 HOOK_VECTOR_END (calls)
4899 DEFHOOK
4900 (use_pseudo_pic_reg,
4901 "This hook should return 1 in case pseudo register should be created\n\
4902 for pic_offset_table_rtx during function expand.",
4903 bool, (void),
4904 hook_bool_void_false)
4906 DEFHOOK
4907 (init_pic_reg,
4908 "Perform a target dependent initialization of pic_offset_table_rtx.\n\
4909 This hook is called at the start of register allocation.",
4910 void, (void),
4911 hook_void_void)
4913 /* Return the diagnostic message string if conversion from FROMTYPE
4914 to TOTYPE is not allowed, NULL otherwise. */
4915 DEFHOOK
4916 (invalid_conversion,
4917 "If defined, this macro returns the diagnostic message when it is\n\
4918 invalid to convert from @var{fromtype} to @var{totype}, or @code{NULL}\n\
4919 if validity should be determined by the front end.",
4920 const char *, (const_tree fromtype, const_tree totype),
4921 hook_constcharptr_const_tree_const_tree_null)
4923 /* Return the diagnostic message string if the unary operation OP is
4924 not permitted on TYPE, NULL otherwise. */
4925 DEFHOOK
4926 (invalid_unary_op,
4927 "If defined, this macro returns the diagnostic message when it is\n\
4928 invalid to apply operation @var{op} (where unary plus is denoted by\n\
4929 @code{CONVERT_EXPR}) to an operand of type @var{type}, or @code{NULL}\n\
4930 if validity should be determined by the front end.",
4931 const char *, (int op, const_tree type),
4932 hook_constcharptr_int_const_tree_null)
4934 /* Return the diagnostic message string if the binary operation OP
4935 is not permitted on TYPE1 and TYPE2, NULL otherwise. */
4936 DEFHOOK
4937 (invalid_binary_op,
4938 "If defined, this macro returns the diagnostic message when it is\n\
4939 invalid to apply operation @var{op} to operands of types @var{type1}\n\
4940 and @var{type2}, or @code{NULL} if validity should be determined by\n\
4941 the front end.",
4942 const char *, (int op, const_tree type1, const_tree type2),
4943 hook_constcharptr_int_const_tree_const_tree_null)
4945 /* If values of TYPE are promoted to some other type when used in
4946 expressions (analogous to the integer promotions), return that type,
4947 or NULL_TREE otherwise. */
4948 DEFHOOK
4949 (promoted_type,
4950 "If defined, this target hook returns the type to which values of\n\
4951 @var{type} should be promoted when they appear in expressions,\n\
4952 analogous to the integer promotions, or @code{NULL_TREE} to use the\n\
4953 front end's normal promotion rules. This hook is useful when there are\n\
4954 target-specific types with special promotion rules.\n\
4955 This is currently used only by the C and C++ front ends.",
4956 tree, (const_tree type),
4957 hook_tree_const_tree_null)
4959 /* Convert EXPR to TYPE, if target-specific types with special conversion
4960 rules are involved. Return the converted expression, or NULL to apply
4961 the standard conversion rules. */
4962 DEFHOOK
4963 (convert_to_type,
4964 "If defined, this hook returns the result of converting @var{expr} to\n\
4965 @var{type}. It should return the converted expression,\n\
4966 or @code{NULL_TREE} to apply the front end's normal conversion rules.\n\
4967 This hook is useful when there are target-specific types with special\n\
4968 conversion rules.\n\
4969 This is currently used only by the C and C++ front ends.",
4970 tree, (tree type, tree expr),
4971 hook_tree_tree_tree_null)
4973 /* Change pseudo allocno class calculated by IRA. */
4974 DEFHOOK
4975 (ira_change_pseudo_allocno_class,
4976 "A target hook which can change allocno class for given pseudo from\n\
4977 allocno and best class calculated by IRA.\n\
4979 The default version of this target hook always returns given class.",
4980 reg_class_t, (int, reg_class_t, reg_class_t),
4981 default_ira_change_pseudo_allocno_class)
4983 /* Return true if we use LRA instead of reload. */
4984 DEFHOOK
4985 (lra_p,
4986 "A target hook which returns true if we use LRA instead of reload pass.\
4988 The default version of this target hook returns true. New ports\
4989 should use LRA, and existing ports are encouraged to convert.",
4990 bool, (void),
4991 default_lra_p)
4993 /* Return register priority of given hard regno for the current target. */
4994 DEFHOOK
4995 (register_priority,
4996 "A target hook which returns the register priority number to which the\
4997 register @var{hard_regno} belongs to. The bigger the number, the\
4998 more preferable the hard register usage (when all other conditions are\
4999 the same). This hook can be used to prefer some hard register over\
5000 others in LRA. For example, some x86-64 register usage needs\
5001 additional prefix which makes instructions longer. The hook can\
5002 return lower priority number for such registers make them less favorable\
5003 and as result making the generated code smaller.\
5005 The default version of this target hook returns always zero.",
5006 int, (int),
5007 default_register_priority)
5009 /* Return true if we need register usage leveling. */
5010 DEFHOOK
5011 (register_usage_leveling_p,
5012 "A target hook which returns true if we need register usage leveling.\
5013 That means if a few hard registers are equally good for the\
5014 assignment, we choose the least used hard register. The register\
5015 usage leveling may be profitable for some targets. Don't use the\
5016 usage leveling for targets with conditional execution or targets\
5017 with big register files as it hurts if-conversion and cross-jumping\
5018 optimizations.\
5020 The default version of this target hook returns always false.",
5021 bool, (void),
5022 default_register_usage_leveling_p)
5024 /* Return true if maximal address displacement can be different. */
5025 DEFHOOK
5026 (different_addr_displacement_p,
5027 "A target hook which returns true if an address with the same structure\
5028 can have different maximal legitimate displacement. For example, the\
5029 displacement can depend on memory mode or on operand combinations in\
5030 the insn.\
5032 The default version of this target hook returns always false.",
5033 bool, (void),
5034 default_different_addr_displacement_p)
5036 /* Determine class for spilling pseudos of given mode into registers
5037 instead of memory. */
5038 DEFHOOK
5039 (spill_class,
5040 "This hook defines a class of registers which could be used for spilling\
5041 pseudos of the given mode and class, or @code{NO_REGS} if only memory\
5042 should be used. Not defining this hook is equivalent to returning\
5043 @code{NO_REGS} for all inputs.",
5044 reg_class_t, (reg_class_t, machine_mode),
5045 NULL)
5047 /* Determine an additional allocno class. */
5048 DEFHOOK
5049 (additional_allocno_class_p,
5050 "This hook should return @code{true} if given class of registers should\
5051 be an allocno class in any way. Usually RA uses only one register\
5052 class from all classes containing the same register set. In some\
5053 complicated cases, you need to have two or more such classes as\
5054 allocno ones for RA correct work. Not defining this hook is\
5055 equivalent to returning @code{false} for all inputs.",
5056 bool, (reg_class_t),
5057 hook_bool_reg_class_t_false)
5059 DEFHOOK
5060 (cstore_mode,
5061 "This hook defines the machine mode to use for the boolean result of\
5062 conditional store patterns. The ICODE argument is the instruction code\
5063 for the cstore being performed. Not definiting this hook is the same\
5064 as accepting the mode encoded into operand 0 of the cstore expander\
5065 patterns.",
5066 machine_mode, (enum insn_code icode),
5067 default_cstore_mode)
5069 /* This target hook allows the backend to compute the register pressure
5070 classes to use. */
5071 DEFHOOK
5072 (compute_pressure_classes,
5073 "A target hook which lets a backend compute the set of pressure classes to\
5074 be used by those optimization passes which take register pressure into\
5075 account, as opposed to letting IRA compute them. It returns the number of\
5076 register classes stored in the array @var{pressure_classes}.",
5077 int, (enum reg_class *pressure_classes), NULL)
5079 /* True if a structure, union or array with MODE containing FIELD should
5080 be accessed using BLKmode. */
5081 DEFHOOK
5082 (member_type_forces_blk,
5083 "Return true if a structure, union or array containing @var{field} should\n\
5084 be accessed using @code{BLKMODE}.\n\
5086 If @var{field} is the only field in the structure, @var{mode} is its\n\
5087 mode, otherwise @var{mode} is VOIDmode. @var{mode} is provided in the\n\
5088 case where structures of one field would require the structure's mode to\n\
5089 retain the field's mode.\n\
5091 Normally, this is not needed.",
5092 bool, (const_tree field, machine_mode mode),
5093 default_member_type_forces_blk)
5095 /* See tree-ssa-math-opts.c:divmod_candidate_p for conditions
5096 that gate the divod transform. */
5097 DEFHOOK
5098 (expand_divmod_libfunc,
5099 "Define this hook for enabling divmod transform if the port does not have\n\
5100 hardware divmod insn but defines target-specific divmod libfuncs.",
5101 void, (rtx libfunc, machine_mode mode, rtx op0, rtx op1, rtx *quot, rtx *rem),
5102 NULL)
5104 /* Return the class for a secondary reload, and fill in extra information. */
5105 DEFHOOK
5106 (secondary_reload,
5107 "Many machines have some registers that cannot be copied directly to or\n\
5108 from memory or even from other types of registers. An example is the\n\
5109 @samp{MQ} register, which on most machines, can only be copied to or\n\
5110 from general registers, but not memory. Below, we shall be using the\n\
5111 term 'intermediate register' when a move operation cannot be performed\n\
5112 directly, but has to be done by copying the source into the intermediate\n\
5113 register first, and then copying the intermediate register to the\n\
5114 destination. An intermediate register always has the same mode as\n\
5115 source and destination. Since it holds the actual value being copied,\n\
5116 reload might apply optimizations to re-use an intermediate register\n\
5117 and eliding the copy from the source when it can determine that the\n\
5118 intermediate register still holds the required value.\n\
5120 Another kind of secondary reload is required on some machines which\n\
5121 allow copying all registers to and from memory, but require a scratch\n\
5122 register for stores to some memory locations (e.g., those with symbolic\n\
5123 address on the RT, and those with certain symbolic address on the SPARC\n\
5124 when compiling PIC)@. Scratch registers need not have the same mode\n\
5125 as the value being copied, and usually hold a different value than\n\
5126 that being copied. Special patterns in the md file are needed to\n\
5127 describe how the copy is performed with the help of the scratch register;\n\
5128 these patterns also describe the number, register class(es) and mode(s)\n\
5129 of the scratch register(s).\n\
5131 In some cases, both an intermediate and a scratch register are required.\n\
5133 For input reloads, this target hook is called with nonzero @var{in_p},\n\
5134 and @var{x} is an rtx that needs to be copied to a register of class\n\
5135 @var{reload_class} in @var{reload_mode}. For output reloads, this target\n\
5136 hook is called with zero @var{in_p}, and a register of class @var{reload_class}\n\
5137 needs to be copied to rtx @var{x} in @var{reload_mode}.\n\
5139 If copying a register of @var{reload_class} from/to @var{x} requires\n\
5140 an intermediate register, the hook @code{secondary_reload} should\n\
5141 return the register class required for this intermediate register.\n\
5142 If no intermediate register is required, it should return NO_REGS.\n\
5143 If more than one intermediate register is required, describe the one\n\
5144 that is closest in the copy chain to the reload register.\n\
5146 If scratch registers are needed, you also have to describe how to\n\
5147 perform the copy from/to the reload register to/from this\n\
5148 closest intermediate register. Or if no intermediate register is\n\
5149 required, but still a scratch register is needed, describe the\n\
5150 copy from/to the reload register to/from the reload operand @var{x}.\n\
5152 You do this by setting @code{sri->icode} to the instruction code of a pattern\n\
5153 in the md file which performs the move. Operands 0 and 1 are the output\n\
5154 and input of this copy, respectively. Operands from operand 2 onward are\n\
5155 for scratch operands. These scratch operands must have a mode, and a\n\
5156 single-register-class\n\
5157 @c [later: or memory]\n\
5158 output constraint.\n\
5160 When an intermediate register is used, the @code{secondary_reload}\n\
5161 hook will be called again to determine how to copy the intermediate\n\
5162 register to/from the reload operand @var{x}, so your hook must also\n\
5163 have code to handle the register class of the intermediate operand.\n\
5165 @c [For later: maybe we'll allow multi-alternative reload patterns -\n\
5166 @c the port maintainer could name a mov<mode> pattern that has clobbers -\n\
5167 @c and match the constraints of input and output to determine the required\n\
5168 @c alternative. A restriction would be that constraints used to match\n\
5169 @c against reloads registers would have to be written as register class\n\
5170 @c constraints, or we need a new target macro / hook that tells us if an\n\
5171 @c arbitrary constraint can match an unknown register of a given class.\n\
5172 @c Such a macro / hook would also be useful in other places.]\n\
5175 @var{x} might be a pseudo-register or a @code{subreg} of a\n\
5176 pseudo-register, which could either be in a hard register or in memory.\n\
5177 Use @code{true_regnum} to find out; it will return @minus{}1 if the pseudo is\n\
5178 in memory and the hard register number if it is in a register.\n\
5180 Scratch operands in memory (constraint @code{\"=m\"} / @code{\"=&m\"}) are\n\
5181 currently not supported. For the time being, you will have to continue\n\
5182 to use @code{SECONDARY_MEMORY_NEEDED} for that purpose.\n\
5184 @code{copy_cost} also uses this target hook to find out how values are\n\
5185 copied. If you want it to include some extra cost for the need to allocate\n\
5186 (a) scratch register(s), set @code{sri->extra_cost} to the additional cost.\n\
5187 Or if two dependent moves are supposed to have a lower cost than the sum\n\
5188 of the individual moves due to expected fortuitous scheduling and/or special\n\
5189 forwarding logic, you can set @code{sri->extra_cost} to a negative amount.",
5190 reg_class_t,
5191 (bool in_p, rtx x, reg_class_t reload_class, machine_mode reload_mode,
5192 secondary_reload_info *sri),
5193 default_secondary_reload)
5195 /* Given an rtx X being reloaded into a reg required to be in class CLASS,
5196 return the class of reg to actually use. */
5197 DEFHOOK
5198 (preferred_reload_class,
5199 "A target hook that places additional restrictions on the register class\n\
5200 to use when it is necessary to copy value @var{x} into a register in class\n\
5201 @var{rclass}. The value is a register class; perhaps @var{rclass}, or perhaps\n\
5202 another, smaller class.\n\
5204 The default version of this hook always returns value of @code{rclass} argument.\n\
5206 Sometimes returning a more restrictive class makes better code. For\n\
5207 example, on the 68000, when @var{x} is an integer constant that is in range\n\
5208 for a @samp{moveq} instruction, the value of this macro is always\n\
5209 @code{DATA_REGS} as long as @var{rclass} includes the data registers.\n\
5210 Requiring a data register guarantees that a @samp{moveq} will be used.\n\
5212 One case where @code{TARGET_PREFERRED_RELOAD_CLASS} must not return\n\
5213 @var{rclass} is if @var{x} is a legitimate constant which cannot be\n\
5214 loaded into some register class. By returning @code{NO_REGS} you can\n\
5215 force @var{x} into a memory location. For example, rs6000 can load\n\
5216 immediate values into general-purpose registers, but does not have an\n\
5217 instruction for loading an immediate value into a floating-point\n\
5218 register, so @code{TARGET_PREFERRED_RELOAD_CLASS} returns @code{NO_REGS} when\n\
5219 @var{x} is a floating-point constant. If the constant can't be loaded\n\
5220 into any kind of register, code generation will be better if\n\
5221 @code{TARGET_LEGITIMATE_CONSTANT_P} makes the constant illegitimate instead\n\
5222 of using @code{TARGET_PREFERRED_RELOAD_CLASS}.\n\
5224 If an insn has pseudos in it after register allocation, reload will go\n\
5225 through the alternatives and call repeatedly @code{TARGET_PREFERRED_RELOAD_CLASS}\n\
5226 to find the best one. Returning @code{NO_REGS}, in this case, makes\n\
5227 reload add a @code{!} in front of the constraint: the x86 back-end uses\n\
5228 this feature to discourage usage of 387 registers when math is done in\n\
5229 the SSE registers (and vice versa).",
5230 reg_class_t,
5231 (rtx x, reg_class_t rclass),
5232 default_preferred_reload_class)
5234 /* Like TARGET_PREFERRED_RELOAD_CLASS, but for output reloads instead of
5235 input reloads. */
5236 DEFHOOK
5237 (preferred_output_reload_class,
5238 "Like @code{TARGET_PREFERRED_RELOAD_CLASS}, but for output reloads instead of\n\
5239 input reloads.\n\
5241 The default version of this hook always returns value of @code{rclass}\n\
5242 argument.\n\
5244 You can also use @code{TARGET_PREFERRED_OUTPUT_RELOAD_CLASS} to discourage\n\
5245 reload from using some alternatives, like @code{TARGET_PREFERRED_RELOAD_CLASS}.",
5246 reg_class_t,
5247 (rtx x, reg_class_t rclass),
5248 default_preferred_output_reload_class)
5250 DEFHOOK
5251 (class_likely_spilled_p,
5252 "A target hook which returns @code{true} if pseudos that have been assigned\n\
5253 to registers of class @var{rclass} would likely be spilled because\n\
5254 registers of @var{rclass} are needed for spill registers.\n\
5256 The default version of this target hook returns @code{true} if @var{rclass}\n\
5257 has exactly one register and @code{false} otherwise. On most machines, this\n\
5258 default should be used. For generally register-starved machines, such as\n\
5259 i386, or machines with right register constraints, such as SH, this hook\n\
5260 can be used to avoid excessive spilling.\n\
5262 This hook is also used by some of the global intra-procedural code\n\
5263 transformations to throtle code motion, to avoid increasing register\n\
5264 pressure.",
5265 bool, (reg_class_t rclass),
5266 default_class_likely_spilled_p)
5268 /* Return the maximum number of consecutive registers
5269 needed to represent mode MODE in a register of class RCLASS. */
5270 DEFHOOK
5271 (class_max_nregs,
5272 "A target hook returns the maximum number of consecutive registers\n\
5273 of class @var{rclass} needed to hold a value of mode @var{mode}.\n\
5275 This is closely related to the macro @code{HARD_REGNO_NREGS}. In fact,\n\
5276 the value returned by @code{TARGET_CLASS_MAX_NREGS (@var{rclass},\n\
5277 @var{mode})} target hook should be the maximum value of\n\
5278 @code{HARD_REGNO_NREGS (@var{regno}, @var{mode})} for all @var{regno}\n\
5279 values in the class @var{rclass}.\n\
5281 This target hook helps control the handling of multiple-word values\n\
5282 in the reload pass.\n\
5284 The default version of this target hook returns the size of @var{mode}\n\
5285 in words.",
5286 unsigned char, (reg_class_t rclass, machine_mode mode),
5287 default_class_max_nregs)
5289 DEFHOOK
5290 (preferred_rename_class,
5291 "A target hook that places additional preference on the register\
5292 class to use when it is necessary to rename a register in class\
5293 @var{rclass} to another class, or perhaps @var{NO_REGS}, if no\
5294 preferred register class is found or hook @code{preferred_rename_class}\
5295 is not implemented.\
5296 Sometimes returning a more restrictive class makes better code. For\
5297 example, on ARM, thumb-2 instructions using @code{LO_REGS} may be\
5298 smaller than instructions using @code{GENERIC_REGS}. By returning\
5299 @code{LO_REGS} from @code{preferred_rename_class}, code size can\
5300 be reduced.",
5301 reg_class_t, (reg_class_t rclass),
5302 default_preferred_rename_class)
5304 /* This target hook allows the backend to avoid unsafe substitution
5305 during register allocation. */
5306 DEFHOOK
5307 (cannot_substitute_mem_equiv_p,
5308 "A target hook which returns @code{true} if @var{subst} can't\n\
5309 substitute safely pseudos with equivalent memory values during\n\
5310 register allocation.\n\
5311 The default version of this target hook returns @code{false}.\n\
5312 On most machines, this default should be used. For generally\n\
5313 machines with non orthogonal register usage for addressing, such\n\
5314 as SH, this hook can be used to avoid excessive spilling.",
5315 bool, (rtx subst),
5316 hook_bool_rtx_false)
5318 /* This target hook allows the backend to legitimize base plus
5319 displacement addressing. */
5320 DEFHOOK
5321 (legitimize_address_displacement,
5322 "A target hook which returns @code{true} if *@var{disp} is\n\
5323 legitimezed to valid address displacement with subtracting *@var{offset}\n\
5324 at memory mode @var{mode}.\n\
5325 The default version of this target hook returns @code{false}.\n\
5326 This hook will benefit machines with limited base plus displacement\n\
5327 addressing.",
5328 bool, (rtx *disp, rtx *offset, machine_mode mode),
5329 default_legitimize_address_displacement)
5331 /* This target hook allows the backend to perform additional
5332 processing while initializing for variable expansion. */
5333 DEFHOOK
5334 (expand_to_rtl_hook,
5335 "This hook is called just before expansion into rtl, allowing the target\n\
5336 to perform additional initializations or analysis before the expansion.\n\
5337 For example, the rs6000 port uses it to allocate a scratch stack slot\n\
5338 for use in copying SDmode values between memory and floating point\n\
5339 registers whenever the function being expanded has any SDmode\n\
5340 usage.",
5341 void, (void),
5342 hook_void_void)
5344 /* This target hook allows the backend to perform additional
5345 instantiations on rtx that are not actually in insns yet,
5346 but will be later. */
5347 DEFHOOK
5348 (instantiate_decls,
5349 "This hook allows the backend to perform additional instantiations on rtl\n\
5350 that are not actually in any insns yet, but will be later.",
5351 void, (void),
5352 hook_void_void)
5354 /* Return true if is OK to use a hard register REGNO as scratch register
5355 in peephole2. */
5356 DEFHOOK
5357 (hard_regno_scratch_ok,
5358 "This target hook should return @code{true} if it is OK to use a hard register\n\
5359 @var{regno} as scratch reg in peephole2.\n\
5361 One common use of this macro is to prevent using of a register that\n\
5362 is not saved by a prologue in an interrupt handler.\n\
5364 The default version of this hook always returns @code{true}.",
5365 bool, (unsigned int regno),
5366 default_hard_regno_scratch_ok)
5368 /* Return the smallest number of different values for which it is best to
5369 use a jump-table instead of a tree of conditional branches. */
5370 DEFHOOK
5371 (case_values_threshold,
5372 "This function return the smallest number of different values for which it\n\
5373 is best to use a jump-table instead of a tree of conditional branches.\n\
5374 The default is four for machines with a @code{casesi} instruction and\n\
5375 five otherwise. This is best for most machines.",
5376 unsigned int, (void),
5377 default_case_values_threshold)
5379 /* Return true if a function must have and use a frame pointer. */
5380 DEFHOOK
5381 (frame_pointer_required,
5382 "This target hook should return @code{true} if a function must have and use\n\
5383 a frame pointer. This target hook is called in the reload pass. If its return\n\
5384 value is @code{true} the function will have a frame pointer.\n\
5386 This target hook can in principle examine the current function and decide\n\
5387 according to the facts, but on most machines the constant @code{false} or the\n\
5388 constant @code{true} suffices. Use @code{false} when the machine allows code\n\
5389 to be generated with no frame pointer, and doing so saves some time or space.\n\
5390 Use @code{true} when there is no possible advantage to avoiding a frame\n\
5391 pointer.\n\
5393 In certain cases, the compiler does not know how to produce valid code\n\
5394 without a frame pointer. The compiler recognizes those cases and\n\
5395 automatically gives the function a frame pointer regardless of what\n\
5396 @code{targetm.frame_pointer_required} returns. You don't need to worry about\n\
5397 them.\n\
5399 In a function that does not require a frame pointer, the frame pointer\n\
5400 register can be allocated for ordinary usage, unless you mark it as a\n\
5401 fixed register. See @code{FIXED_REGISTERS} for more information.\n\
5403 Default return value is @code{false}.",
5404 bool, (void),
5405 hook_bool_void_false)
5407 /* Returns true if the compiler is allowed to try to replace register number
5408 from-reg with register number to-reg. */
5409 DEFHOOK
5410 (can_eliminate,
5411 "This target hook should return @code{true} if the compiler is allowed to\n\
5412 try to replace register number @var{from_reg} with register number\n\
5413 @var{to_reg}. This target hook will usually be @code{true}, since most of the\n\
5414 cases preventing register elimination are things that the compiler already\n\
5415 knows about.\n\
5417 Default return value is @code{true}.",
5418 bool, (const int from_reg, const int to_reg),
5419 hook_bool_const_int_const_int_true)
5421 /* Modify any or all of fixed_regs, call_used_regs, global_regs,
5422 reg_names, and reg_class_contents to account of the vagaries of the
5423 target. */
5424 DEFHOOK
5425 (conditional_register_usage,
5426 "This hook may conditionally modify five variables\n\
5427 @code{fixed_regs}, @code{call_used_regs}, @code{global_regs},\n\
5428 @code{reg_names}, and @code{reg_class_contents}, to take into account\n\
5429 any dependence of these register sets on target flags. The first three\n\
5430 of these are of type @code{char []} (interpreted as boolean vectors).\n\
5431 @code{global_regs} is a @code{const char *[]}, and\n\
5432 @code{reg_class_contents} is a @code{HARD_REG_SET}. Before the macro is\n\
5433 called, @code{fixed_regs}, @code{call_used_regs},\n\
5434 @code{reg_class_contents}, and @code{reg_names} have been initialized\n\
5435 from @code{FIXED_REGISTERS}, @code{CALL_USED_REGISTERS},\n\
5436 @code{REG_CLASS_CONTENTS}, and @code{REGISTER_NAMES}, respectively.\n\
5437 @code{global_regs} has been cleared, and any @option{-ffixed-@var{reg}},\n\
5438 @option{-fcall-used-@var{reg}} and @option{-fcall-saved-@var{reg}}\n\
5439 command options have been applied.\n\
5441 @cindex disabling certain registers\n\
5442 @cindex controlling register usage\n\
5443 If the usage of an entire class of registers depends on the target\n\
5444 flags, you may indicate this to GCC by using this macro to modify\n\
5445 @code{fixed_regs} and @code{call_used_regs} to 1 for each of the\n\
5446 registers in the classes which should not be used by GCC@. Also make\n\
5447 @code{define_register_constraint}s return @code{NO_REGS} for constraints\n\
5448 that shouldn't be used.\n\
5450 (However, if this class is not included in @code{GENERAL_REGS} and all\n\
5451 of the insn patterns whose constraints permit this class are\n\
5452 controlled by target switches, then GCC will automatically avoid using\n\
5453 these registers when the target switches are opposed to them.)",
5454 void, (void),
5455 hook_void_void)
5457 /* Functions specific to the C family of frontends. */
5458 #undef HOOK_PREFIX
5459 #define HOOK_PREFIX "TARGET_C_"
5460 HOOK_VECTOR (TARGET_C, c)
5462 /* ??? Documenting this hook requires a GFDL license grant. */
5463 DEFHOOK_UNDOC
5464 (mode_for_suffix,
5465 "Return machine mode for non-standard constant literal suffix @var{c},\
5466 or VOIDmode if non-standard suffixes are unsupported.",
5467 machine_mode, (char c),
5468 default_mode_for_suffix)
5470 DEFHOOK
5471 (excess_precision,
5472 "Return a value, with the same meaning as the C99 macro\
5473 @code{FLT_EVAL_METHOD} that describes which excess precision should be\
5474 applied. @var{type} is either @code{EXCESS_PRECISION_TYPE_IMPLICIT},\
5475 @code{EXCESS_PRECISION_TYPE_FAST}, or\
5476 @code{EXCESS_PRECISION_TYPE_STANDARD}. For\
5477 @code{EXCESS_PRECISION_TYPE_IMPLICIT}, the target should return which\
5478 precision and range operations will be implictly evaluated in regardless\
5479 of the excess precision explicitly added. For\
5480 @code{EXCESS_PRECISION_TYPE_STANDARD} and\
5481 @code{EXCESS_PRECISION_TYPE_FAST}, the target should return the\
5482 explicit excess precision that should be added depending on the\
5483 value set for @option{-fexcess-precision=@r{[}standard@r{|}fast@r{]}}.\
5484 Note that unpredictable explicit excess precision does not make sense,\
5485 so a target should never return @code{FLT_EVAL_METHOD_UNPREDICTABLE}\
5486 when @var{type} is @code{EXCESS_PRECISION_TYPE_STANDARD} or\
5487 @code{EXCESS_PRECISION_TYPE_FAST}.",
5488 enum flt_eval_method, (enum excess_precision_type type),
5489 default_excess_precision)
5491 HOOK_VECTOR_END (c)
5493 /* Functions specific to the C++ frontend. */
5494 #undef HOOK_PREFIX
5495 #define HOOK_PREFIX "TARGET_CXX_"
5496 HOOK_VECTOR (TARGET_CXX, cxx)
5498 /* Return the integer type used for guard variables. */
5499 DEFHOOK
5500 (guard_type,
5501 "Define this hook to override the integer type used for guard variables.\n\
5502 These are used to implement one-time construction of static objects. The\n\
5503 default is long_long_integer_type_node.",
5504 tree, (void),
5505 default_cxx_guard_type)
5507 /* Return true if only the low bit of the guard should be tested. */
5508 DEFHOOK
5509 (guard_mask_bit,
5510 "This hook determines how guard variables are used. It should return\n\
5511 @code{false} (the default) if the first byte should be used. A return value of\n\
5512 @code{true} indicates that only the least significant bit should be used.",
5513 bool, (void),
5514 hook_bool_void_false)
5516 /* Returns the size of the array cookie for an array of type. */
5517 DEFHOOK
5518 (get_cookie_size,
5519 "This hook returns the size of the cookie to use when allocating an array\n\
5520 whose elements have the indicated @var{type}. Assumes that it is already\n\
5521 known that a cookie is needed. The default is\n\
5522 @code{max(sizeof (size_t), alignof(type))}, as defined in section 2.7 of the\n\
5523 IA64/Generic C++ ABI@.",
5524 tree, (tree type),
5525 default_cxx_get_cookie_size)
5527 /* Returns true if the element size should be stored in the array cookie. */
5528 DEFHOOK
5529 (cookie_has_size,
5530 "This hook should return @code{true} if the element size should be stored in\n\
5531 array cookies. The default is to return @code{false}.",
5532 bool, (void),
5533 hook_bool_void_false)
5535 /* Allows backends to perform additional processing when
5536 deciding if a class should be exported or imported. */
5537 DEFHOOK
5538 (import_export_class,
5539 "If defined by a backend this hook allows the decision made to export\n\
5540 class @var{type} to be overruled. Upon entry @var{import_export}\n\
5541 will contain 1 if the class is going to be exported, @minus{}1 if it is going\n\
5542 to be imported and 0 otherwise. This function should return the\n\
5543 modified value and perform any other actions necessary to support the\n\
5544 backend's targeted operating system.",
5545 int, (tree type, int import_export), NULL)
5547 /* Returns true if constructors and destructors return "this". */
5548 DEFHOOK
5549 (cdtor_returns_this,
5550 "This hook should return @code{true} if constructors and destructors return\n\
5551 the address of the object created/destroyed. The default is to return\n\
5552 @code{false}.",
5553 bool, (void),
5554 hook_bool_void_false)
5556 /* Returns true if the key method for a class can be an inline
5557 function, so long as it is not declared inline in the class
5558 itself. Returning true is the behavior required by the Itanium C++ ABI. */
5559 DEFHOOK
5560 (key_method_may_be_inline,
5561 "This hook returns true if the key method for a class (i.e., the method\n\
5562 which, if defined in the current translation unit, causes the virtual\n\
5563 table to be emitted) may be an inline function. Under the standard\n\
5564 Itanium C++ ABI the key method may be an inline function so long as\n\
5565 the function is not declared inline in the class definition. Under\n\
5566 some variants of the ABI, an inline function can never be the key\n\
5567 method. The default is to return @code{true}.",
5568 bool, (void),
5569 hook_bool_void_true)
5571 DEFHOOK
5572 (determine_class_data_visibility,
5573 "@var{decl} is a virtual table, virtual table table, typeinfo object,\
5574 or other similar implicit class data object that will be emitted with\
5575 external linkage in this translation unit. No ELF visibility has been\
5576 explicitly specified. If the target needs to specify a visibility\
5577 other than that of the containing class, use this hook to set\
5578 @code{DECL_VISIBILITY} and @code{DECL_VISIBILITY_SPECIFIED}.",
5579 void, (tree decl),
5580 hook_void_tree)
5582 /* Returns true (the default) if virtual tables and other
5583 similar implicit class data objects are always COMDAT if they
5584 have external linkage. If this hook returns false, then
5585 class data for classes whose virtual table will be emitted in
5586 only one translation unit will not be COMDAT. */
5587 DEFHOOK
5588 (class_data_always_comdat,
5589 "This hook returns true (the default) if virtual tables and other\n\
5590 similar implicit class data objects are always COMDAT if they have\n\
5591 external linkage. If this hook returns false, then class data for\n\
5592 classes whose virtual table will be emitted in only one translation\n\
5593 unit will not be COMDAT.",
5594 bool, (void),
5595 hook_bool_void_true)
5597 /* Returns true (the default) if the RTTI for the basic types,
5598 which is always defined in the C++ runtime, should be COMDAT;
5599 false if it should not be COMDAT. */
5600 DEFHOOK
5601 (library_rtti_comdat,
5602 "This hook returns true (the default) if the RTTI information for\n\
5603 the basic types which is defined in the C++ runtime should always\n\
5604 be COMDAT, false if it should not be COMDAT.",
5605 bool, (void),
5606 hook_bool_void_true)
5608 /* Returns true if __aeabi_atexit should be used to register static
5609 destructors. */
5610 DEFHOOK
5611 (use_aeabi_atexit,
5612 "This hook returns true if @code{__aeabi_atexit} (as defined by the ARM EABI)\n\
5613 should be used to register static destructors when @option{-fuse-cxa-atexit}\n\
5614 is in effect. The default is to return false to use @code{__cxa_atexit}.",
5615 bool, (void),
5616 hook_bool_void_false)
5618 /* Returns true if target may use atexit in the same manner as
5619 __cxa_atexit to register static destructors. */
5620 DEFHOOK
5621 (use_atexit_for_cxa_atexit,
5622 "This hook returns true if the target @code{atexit} function can be used\n\
5623 in the same manner as @code{__cxa_atexit} to register C++ static\n\
5624 destructors. This requires that @code{atexit}-registered functions in\n\
5625 shared libraries are run in the correct order when the libraries are\n\
5626 unloaded. The default is to return false.",
5627 bool, (void),
5628 hook_bool_void_false)
5630 DEFHOOK
5631 (adjust_class_at_definition,
5632 "@var{type} is a C++ class (i.e., RECORD_TYPE or UNION_TYPE) that has just\
5633 been defined. Use this hook to make adjustments to the class (eg, tweak\
5634 visibility or perform any other required target modifications).",
5635 void, (tree type),
5636 hook_void_tree)
5638 DEFHOOK
5639 (decl_mangling_context,
5640 "Return target-specific mangling context of @var{decl} or @code{NULL_TREE}.",
5641 tree, (const_tree decl),
5642 hook_tree_const_tree_null)
5644 HOOK_VECTOR_END (cxx)
5646 /* Functions and data for emulated TLS support. */
5647 #undef HOOK_PREFIX
5648 #define HOOK_PREFIX "TARGET_EMUTLS_"
5649 HOOK_VECTOR (TARGET_EMUTLS, emutls)
5651 /* Name of the address and common functions. */
5652 DEFHOOKPOD
5653 (get_address,
5654 "Contains the name of the helper function that uses a TLS control\n\
5655 object to locate a TLS instance. The default causes libgcc's\n\
5656 emulated TLS helper function to be used.",
5657 const char *, "__builtin___emutls_get_address")
5659 DEFHOOKPOD
5660 (register_common,
5661 "Contains the name of the helper function that should be used at\n\
5662 program startup to register TLS objects that are implicitly\n\
5663 initialized to zero. If this is @code{NULL}, all TLS objects will\n\
5664 have explicit initializers. The default causes libgcc's emulated TLS\n\
5665 registration function to be used.",
5666 const char *, "__builtin___emutls_register_common")
5668 /* Prefixes for proxy variable and template. */
5669 DEFHOOKPOD
5670 (var_section,
5671 "Contains the name of the section in which TLS control variables should\n\
5672 be placed. The default of @code{NULL} allows these to be placed in\n\
5673 any section.",
5674 const char *, NULL)
5676 DEFHOOKPOD
5677 (tmpl_section,
5678 "Contains the name of the section in which TLS initializers should be\n\
5679 placed. The default of @code{NULL} allows these to be placed in any\n\
5680 section.",
5681 const char *, NULL)
5683 /* Prefixes for proxy variable and template. */
5684 DEFHOOKPOD
5685 (var_prefix,
5686 "Contains the prefix to be prepended to TLS control variable names.\n\
5687 The default of @code{NULL} uses a target-specific prefix.",
5688 const char *, NULL)
5690 DEFHOOKPOD
5691 (tmpl_prefix,
5692 "Contains the prefix to be prepended to TLS initializer objects. The\n\
5693 default of @code{NULL} uses a target-specific prefix.",
5694 const char *, NULL)
5696 /* Function to generate field definitions of the proxy variable. */
5697 DEFHOOK
5698 (var_fields,
5699 "Specifies a function that generates the FIELD_DECLs for a TLS control\n\
5700 object type. @var{type} is the RECORD_TYPE the fields are for and\n\
5701 @var{name} should be filled with the structure tag, if the default of\n\
5702 @code{__emutls_object} is unsuitable. The default creates a type suitable\n\
5703 for libgcc's emulated TLS function.",
5704 tree, (tree type, tree *name),
5705 default_emutls_var_fields)
5707 /* Function to initialize a proxy variable. */
5708 DEFHOOK
5709 (var_init,
5710 "Specifies a function that generates the CONSTRUCTOR to initialize a\n\
5711 TLS control object. @var{var} is the TLS control object, @var{decl}\n\
5712 is the TLS object and @var{tmpl_addr} is the address of the\n\
5713 initializer. The default initializes libgcc's emulated TLS control object.",
5714 tree, (tree var, tree decl, tree tmpl_addr),
5715 default_emutls_var_init)
5717 /* Whether we are allowed to alter the usual alignment of the
5718 proxy variable. */
5719 DEFHOOKPOD
5720 (var_align_fixed,
5721 "Specifies whether the alignment of TLS control variable objects is\n\
5722 fixed and should not be increased as some backends may do to optimize\n\
5723 single objects. The default is false.",
5724 bool, false)
5726 /* Whether we can emit debug information for TLS vars. */
5727 DEFHOOKPOD
5728 (debug_form_tls_address,
5729 "Specifies whether a DWARF @code{DW_OP_form_tls_address} location descriptor\n\
5730 may be used to describe emulated TLS control objects.",
5731 bool, false)
5733 HOOK_VECTOR_END (emutls)
5735 #undef HOOK_PREFIX
5736 #define HOOK_PREFIX "TARGET_OPTION_"
5737 HOOK_VECTOR (TARGET_OPTION_HOOKS, target_option_hooks)
5739 /* Function to validate the attribute((target(...))) strings. If
5740 the option is validated, the hook should also fill in
5741 DECL_FUNCTION_SPECIFIC_TARGET in the function decl node. */
5742 DEFHOOK
5743 (valid_attribute_p,
5744 "This hook is called to parse @code{attribute(target(\"...\"))}, which\n\
5745 allows setting target-specific options on individual functions.\n\
5746 These function-specific options may differ\n\
5747 from the options specified on the command line. The hook should return\n\
5748 @code{true} if the options are valid.\n\
5750 The hook should set the @code{DECL_FUNCTION_SPECIFIC_TARGET} field in\n\
5751 the function declaration to hold a pointer to a target-specific\n\
5752 @code{struct cl_target_option} structure.",
5753 bool, (tree fndecl, tree name, tree args, int flags),
5754 default_target_option_valid_attribute_p)
5756 /* Function to save any extra target state in the target options structure. */
5757 DEFHOOK
5758 (save,
5759 "This hook is called to save any additional target-specific information\n\
5760 in the @code{struct cl_target_option} structure for function-specific\n\
5761 options from the @code{struct gcc_options} structure.\n\
5762 @xref{Option file format}.",
5763 void, (struct cl_target_option *ptr, struct gcc_options *opts), NULL)
5765 /* Function to restore any extra target state from the target options
5766 structure. */
5767 DEFHOOK
5768 (restore,
5769 "This hook is called to restore any additional target-specific\n\
5770 information in the @code{struct cl_target_option} structure for\n\
5771 function-specific options to the @code{struct gcc_options} structure.",
5772 void, (struct gcc_options *opts, struct cl_target_option *ptr), NULL)
5774 /* Function to update target-specific option information after being
5775 streamed in. */
5776 DEFHOOK
5777 (post_stream_in,
5778 "This hook is called to update target-specific information in the\n\
5779 @code{struct cl_target_option} structure after it is streamed in from\n\
5780 LTO bytecode.",
5781 void, (struct cl_target_option *ptr), NULL)
5783 /* Function to print any extra target state from the target options
5784 structure. */
5785 DEFHOOK
5786 (print,
5787 "This hook is called to print any additional target-specific\n\
5788 information in the @code{struct cl_target_option} structure for\n\
5789 function-specific options.",
5790 void, (FILE *file, int indent, struct cl_target_option *ptr), NULL)
5792 /* Function to parse arguments to be validated for #pragma target, and to
5793 change the state if the options are valid. If the first argument is
5794 NULL, the second argument specifies the default options to use. Return
5795 true if the options are valid, and set the current state. */
5796 DEFHOOK
5797 (pragma_parse,
5798 "This target hook parses the options for @code{#pragma GCC target}, which\n\
5799 sets the target-specific options for functions that occur later in the\n\
5800 input stream. The options accepted should be the same as those handled by the\n\
5801 @code{TARGET_OPTION_VALID_ATTRIBUTE_P} hook.",
5802 bool, (tree args, tree pop_target),
5803 default_target_option_pragma_parse)
5805 /* Do option overrides for the target. */
5806 DEFHOOK
5807 (override,
5808 "Sometimes certain combinations of command options do not make sense on\n\
5809 a particular target machine. You can override the hook\n\
5810 @code{TARGET_OPTION_OVERRIDE} to take account of this. This hooks is called\n\
5811 once just after all the command options have been parsed.\n\
5813 Don't use this hook to turn on various extra optimizations for\n\
5814 @option{-O}. That is what @code{TARGET_OPTION_OPTIMIZATION} is for.\n\
5816 If you need to do something whenever the optimization level is\n\
5817 changed via the optimize attribute or pragma, see\n\
5818 @code{TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE}",
5819 void, (void),
5820 hook_void_void)
5822 /* This function returns true if DECL1 and DECL2 are versions of the same
5823 function. DECL1 and DECL2 are function versions if and only if they
5824 have the same function signature and different target specific attributes,
5825 that is, they are compiled for different target machines. */
5826 DEFHOOK
5827 (function_versions,
5828 "This target hook returns @code{true} if @var{DECL1} and @var{DECL2} are\n\
5829 versions of the same function. @var{DECL1} and @var{DECL2} are function\n\
5830 versions if and only if they have the same function signature and\n\
5831 different target specific attributes, that is, they are compiled for\n\
5832 different target machines.",
5833 bool, (tree decl1, tree decl2),
5834 hook_bool_tree_tree_false)
5836 /* Function to determine if one function can inline another function. */
5837 #undef HOOK_PREFIX
5838 #define HOOK_PREFIX "TARGET_"
5839 DEFHOOK
5840 (can_inline_p,
5841 "This target hook returns @code{false} if the @var{caller} function\n\
5842 cannot inline @var{callee}, based on target specific information. By\n\
5843 default, inlining is not allowed if the callee function has function\n\
5844 specific target options and the caller does not use the same options.",
5845 bool, (tree caller, tree callee),
5846 default_target_can_inline_p)
5848 DEFHOOK
5849 (relayout_function,
5850 "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.",
5851 void, (tree fndecl),
5852 hook_void_tree)
5854 HOOK_VECTOR_END (target_option)
5856 /* For targets that need to mark extra registers as live on entry to
5857 the function, they should define this target hook and set their
5858 bits in the bitmap passed in. */
5859 DEFHOOK
5860 (extra_live_on_entry,
5861 "Add any hard registers to @var{regs} that are live on entry to the\n\
5862 function. This hook only needs to be defined to provide registers that\n\
5863 cannot be found by examination of FUNCTION_ARG_REGNO_P, the callee saved\n\
5864 registers, STATIC_CHAIN_INCOMING_REGNUM, STATIC_CHAIN_REGNUM,\n\
5865 TARGET_STRUCT_VALUE_RTX, FRAME_POINTER_REGNUM, EH_USES,\n\
5866 FRAME_POINTER_REGNUM, ARG_POINTER_REGNUM, and the PIC_OFFSET_TABLE_REGNUM.",
5867 void, (bitmap regs),
5868 hook_void_bitmap)
5870 /* Targets should define this target hook to mark that non-callee clobbers are
5871 present in CALL_INSN_FUNCTION_USAGE for all the calls that bind to a local
5872 definition. */
5873 DEFHOOKPOD
5874 (call_fusage_contains_non_callee_clobbers,
5875 "Set to true if each call that binds to a local definition explicitly\n\
5876 clobbers or sets all non-fixed registers modified by performing the call.\n\
5877 That is, by the call pattern itself, or by code that might be inserted by the\n\
5878 linker (e.g. stubs, veneers, branch islands), but not including those\n\
5879 modifiable by the callee. The affected registers may be mentioned explicitly\n\
5880 in the call pattern, or included as clobbers in CALL_INSN_FUNCTION_USAGE.\n\
5881 The default version of this hook is set to false. The purpose of this hook\n\
5882 is to enable the fipa-ra optimization.",
5883 bool,
5884 false)
5886 /* Fill in additional registers set up by prologue into a regset. */
5887 DEFHOOK
5888 (set_up_by_prologue,
5889 "This hook should add additional registers that are computed by the prologue\
5890 to the hard regset for shrink-wrapping optimization purposes.",
5891 void, (struct hard_reg_set_container *),
5892 NULL)
5894 /* For targets that have attributes that can affect whether a
5895 function's return statements need checking. For instance a 'naked'
5896 function attribute. */
5897 DEFHOOK
5898 (warn_func_return,
5899 "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.",
5900 bool, (tree),
5901 hook_bool_tree_true)
5903 #undef HOOK_PREFIX
5904 #define HOOK_PREFIX "TARGET_SHRINK_WRAP_"
5905 HOOK_VECTOR (TARGET_SHRINK_WRAP_HOOKS, shrink_wrap)
5907 DEFHOOK
5908 (get_separate_components,
5909 "This hook should return an @code{sbitmap} with the bits set for those\n\
5910 components that can be separately shrink-wrapped in the current function.\n\
5911 Return @code{NULL} if the current function should not get any separate\n\
5912 shrink-wrapping.\n\
5913 Don't define this hook if it would always return @code{NULL}.\n\
5914 If it is defined, the other hooks in this group have to be defined as well.",
5915 sbitmap, (void),
5916 NULL)
5918 DEFHOOK
5919 (components_for_bb,
5920 "This hook should return an @code{sbitmap} with the bits set for those\n\
5921 components where either the prologue component has to be executed before\n\
5922 the @code{basic_block}, or the epilogue component after it, or both.",
5923 sbitmap, (basic_block),
5924 NULL)
5926 DEFHOOK
5927 (disqualify_components,
5928 "This hook should clear the bits in the @var{components} bitmap for those\n\
5929 components in @var{edge_components} that the target cannot handle on edge\n\
5930 @var{e}, where @var{is_prologue} says if this is for a prologue or an\n\
5931 epilogue instead.",
5932 void, (sbitmap components, edge e, sbitmap edge_components, bool is_prologue),
5933 NULL)
5935 DEFHOOK
5936 (emit_prologue_components,
5937 "Emit prologue insns for the components indicated by the parameter.",
5938 void, (sbitmap),
5939 NULL)
5941 DEFHOOK
5942 (emit_epilogue_components,
5943 "Emit epilogue insns for the components indicated by the parameter.",
5944 void, (sbitmap),
5945 NULL)
5947 DEFHOOK
5948 (set_handled_components,
5949 "Mark the components in the parameter as handled, so that the\n\
5950 @code{prologue} and @code{epilogue} named patterns know to ignore those\n\
5951 components. The target code should not hang on to the @code{sbitmap}, it\n\
5952 will be deleted after this call.",
5953 void, (sbitmap),
5954 NULL)
5956 HOOK_VECTOR_END (shrink_wrap)
5957 #undef HOOK_PREFIX
5958 #define HOOK_PREFIX "TARGET_"
5960 /* Determine the type of unwind info to emit for debugging. */
5961 DEFHOOK
5962 (debug_unwind_info,
5963 "This hook defines the mechanism that will be used for describing frame\n\
5964 unwind information to the debugger. Normally the hook will return\n\
5965 @code{UI_DWARF2} if DWARF 2 debug information is enabled, and\n\
5966 return @code{UI_NONE} otherwise.\n\
5968 A target may return @code{UI_DWARF2} even when DWARF 2 debug information\n\
5969 is disabled in order to always output DWARF 2 frame information.\n\
5971 A target may return @code{UI_TARGET} if it has ABI specified unwind tables.\n\
5972 This will suppress generation of the normal debug frame unwind information.",
5973 enum unwind_info_type, (void),
5974 default_debug_unwind_info)
5976 /* The code parameter should be of type enum rtx_code but this is not
5977 defined at this time. */
5978 DEFHOOK
5979 (canonicalize_comparison,
5980 "On some machines not all possible comparisons are defined, but you can\n\
5981 convert an invalid comparison into a valid one. For example, the Alpha\n\
5982 does not have a @code{GT} comparison, but you can use an @code{LT}\n\
5983 comparison instead and swap the order of the operands.\n\
5985 On such machines, implement this hook to do any required conversions.\n\
5986 @var{code} is the initial comparison code and @var{op0} and @var{op1}\n\
5987 are the left and right operands of the comparison, respectively. If\n\
5988 @var{op0_preserve_value} is @code{true} the implementation is not\n\
5989 allowed to change the value of @var{op0} since the value might be used\n\
5990 in RTXs which aren't comparisons. E.g. the implementation is not\n\
5991 allowed to swap operands in that case.\n\
5993 GCC will not assume that the comparison resulting from this macro is\n\
5994 valid but will see if the resulting insn matches a pattern in the\n\
5995 @file{md} file.\n\
5997 You need not to implement this hook if it would never change the\n\
5998 comparison code or operands.",
5999 void, (int *code, rtx *op0, rtx *op1, bool op0_preserve_value),
6000 default_canonicalize_comparison)
6002 DEFHOOK
6003 (min_arithmetic_precision,
6004 "On some RISC architectures with 64-bit registers, the processor also\n\
6005 maintains 32-bit condition codes that make it possible to do real 32-bit\n\
6006 arithmetic, although the operations are performed on the full registers.\n\
6008 On such architectures, defining this hook to 32 tells the compiler to try\n\
6009 using 32-bit arithmetical operations setting the condition codes instead\n\
6010 of doing full 64-bit arithmetic.\n\
6012 More generally, define this hook on RISC architectures if you want the\n\
6013 compiler to try using arithmetical operations setting the condition codes\n\
6014 with a precision lower than the word precision.\n\
6016 You need not define this hook if @code{WORD_REGISTER_OPERATIONS} is not\n\
6017 defined to 1.",
6018 unsigned int, (void), default_min_arithmetic_precision)
6020 DEFHOOKPOD
6021 (atomic_test_and_set_trueval,
6022 "This value should be set if the result written by\
6023 @code{atomic_test_and_set} is not exactly 1, i.e. the\
6024 @code{bool} @code{true}.",
6025 unsigned char, 1)
6027 /* Return an unsigned int representing the alignment (in bits) of the atomic
6028 type which maps to machine MODE. This allows alignment to be overridden
6029 as needed. */
6030 DEFHOOK
6031 (atomic_align_for_mode,
6032 "If defined, this function returns an appropriate alignment in bits for an\
6033 atomic object of machine_mode @var{mode}. If 0 is returned then the\
6034 default alignment for the specified mode is used. ",
6035 unsigned int, (machine_mode mode),
6036 hook_uint_mode_0)
6038 DEFHOOK
6039 (atomic_assign_expand_fenv,
6040 "ISO C11 requires atomic compound assignments that may raise floating-point\
6041 exceptions to raise exceptions corresponding to the arithmetic operation\
6042 whose result was successfully stored in a compare-and-exchange sequence. \
6043 This requires code equivalent to calls to @code{feholdexcept},\
6044 @code{feclearexcept} and @code{feupdateenv} to be generated at\
6045 appropriate points in the compare-and-exchange sequence. This hook should\
6046 set @code{*@var{hold}} to an expression equivalent to the call to\
6047 @code{feholdexcept}, @code{*@var{clear}} to an expression equivalent to\
6048 the call to @code{feclearexcept} and @code{*@var{update}} to an expression\
6049 equivalent to the call to @code{feupdateenv}. The three expressions are\
6050 @code{NULL_TREE} on entry to the hook and may be left as @code{NULL_TREE}\
6051 if no code is required in a particular place. The default implementation\
6052 leaves all three expressions as @code{NULL_TREE}. The\
6053 @code{__atomic_feraiseexcept} function from @code{libatomic} may be of use\
6054 as part of the code generated in @code{*@var{update}}.",
6055 void, (tree *hold, tree *clear, tree *update),
6056 default_atomic_assign_expand_fenv)
6058 /* Leave the boolean fields at the end. */
6060 /* True if we can create zeroed data by switching to a BSS section
6061 and then using ASM_OUTPUT_SKIP to allocate the space. */
6062 DEFHOOKPOD
6063 (have_switchable_bss_sections,
6064 "This flag is true if we can create zeroed data by switching to a BSS\n\
6065 section and then using @code{ASM_OUTPUT_SKIP} to allocate the space.\n\
6066 This is true on most ELF targets.",
6067 bool, false)
6069 /* True if "native" constructors and destructors are supported,
6070 false if we're using collect2 for the job. */
6071 DEFHOOKPOD
6072 (have_ctors_dtors,
6073 "This value is true if the target supports some ``native'' method of\n\
6074 collecting constructors and destructors to be run at startup and exit.\n\
6075 It is false if we must use @command{collect2}.",
6076 bool, false)
6078 /* True if thread-local storage is supported. */
6079 DEFHOOKPOD
6080 (have_tls,
6081 "Contains the value true if the target supports thread-local storage.\n\
6082 The default value is false.",
6083 bool, false)
6085 /* True if a small readonly data section is supported. */
6086 DEFHOOKPOD
6087 (have_srodata_section,
6088 "Contains the value true if the target places read-only\n\
6089 ``small data'' into a separate section. The default value is false.",
6090 bool, false)
6092 /* True if EH frame info sections should be zero-terminated. */
6093 DEFHOOKPOD
6094 (terminate_dw2_eh_frame_info,
6095 "Contains the value true if the target should add a zero word onto the\n\
6096 end of a Dwarf-2 frame info section when used for exception handling.\n\
6097 Default value is false if @code{EH_FRAME_SECTION_NAME} is defined, and\n\
6098 true otherwise.",
6099 bool, true)
6101 /* True if #NO_APP should be emitted at the beginning of assembly output. */
6102 DEFHOOKPOD
6103 (asm_file_start_app_off,
6104 "If this flag is true, the text of the macro @code{ASM_APP_OFF} will be\n\
6105 printed as the very first line in the assembly file, unless\n\
6106 @option{-fverbose-asm} is in effect. (If that macro has been defined\n\
6107 to the empty string, this variable has no effect.) With the normal\n\
6108 definition of @code{ASM_APP_OFF}, the effect is to notify the GNU\n\
6109 assembler that it need not bother stripping comments or extra\n\
6110 whitespace from its input. This allows it to work a bit faster.\n\
6112 The default is false. You should not set it to true unless you have\n\
6113 verified that your port does not generate any extra whitespace or\n\
6114 comments that will cause GAS to issue errors in NO_APP mode.",
6115 bool, false)
6117 /* True if output_file_directive should be called for main_input_filename
6118 at the beginning of assembly output. */
6119 DEFHOOKPOD
6120 (asm_file_start_file_directive,
6121 "If this flag is true, @code{output_file_directive} will be called\n\
6122 for the primary source file, immediately after printing\n\
6123 @code{ASM_APP_OFF} (if that is enabled). Most ELF assemblers expect\n\
6124 this to be done. The default is false.",
6125 bool, false)
6127 /* Returns true if we should generate exception tables for use with the
6128 ARM EABI. The effects the encoding of function exception specifications. */
6129 DEFHOOKPOD
6130 (arm_eabi_unwinder,
6131 "This flag should be set to @code{true} on targets that use an ARM EABI\n\
6132 based unwinding library, and @code{false} on other targets. This effects\n\
6133 the format of unwinding tables, and how the unwinder in entered after\n\
6134 running a cleanup. The default is @code{false}.",
6135 bool, false)
6137 DEFHOOKPOD
6138 (want_debug_pub_sections,
6139 "True if the @code{.debug_pubtypes} and @code{.debug_pubnames} sections\
6140 should be emitted. These sections are not used on most platforms, and\
6141 in particular GDB does not use them.",
6142 bool, false)
6144 DEFHOOKPOD
6145 (delay_sched2, "True if sched2 is not to be run at its normal place.\n\
6146 This usually means it will be run as part of machine-specific reorg.",
6147 bool, false)
6149 DEFHOOKPOD
6150 (delay_vartrack, "True if vartrack is not to be run at its normal place.\n\
6151 This usually means it will be run as part of machine-specific reorg.",
6152 bool, false)
6154 DEFHOOKPOD
6155 (no_register_allocation, "True if register allocation and the passes\n\
6156 following it should not be run. Usually true only for virtual assembler\n\
6157 targets.",
6158 bool, false)
6160 /* Leave the boolean fields at the end. */
6162 /* Functions related to mode switching. */
6163 #undef HOOK_PREFIX
6164 #define HOOK_PREFIX "TARGET_MODE_"
6165 HOOK_VECTOR (TARGET_TOGGLE_, mode_switching)
6167 DEFHOOK
6168 (emit,
6169 "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.",
6170 void, (int entity, int mode, int prev_mode, HARD_REG_SET regs_live), NULL)
6172 DEFHOOK
6173 (needed,
6174 "@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}.",
6175 int, (int entity, rtx_insn *insn), NULL)
6177 DEFHOOK
6178 (after,
6179 "@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).",
6180 int, (int entity, int mode, rtx_insn *insn), NULL)
6182 DEFHOOK
6183 (entry,
6184 "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.",
6185 int, (int entity), NULL)
6187 DEFHOOK
6188 (exit,
6189 "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.",
6190 int, (int entity), NULL)
6192 DEFHOOK
6193 (priority,
6194 "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}.",
6195 int, (int entity, int n), NULL)
6197 HOOK_VECTOR_END (mode_switching)
6199 #undef HOOK_PREFIX
6200 #define HOOK_PREFIX "TARGET_"
6202 #define DEF_TARGET_INSN(NAME, PROTO) \
6203 DEFHOOK_UNDOC (have_##NAME, "", bool, (void), false)
6204 #include "target-insns.def"
6205 #undef DEF_TARGET_INSN
6207 #define DEF_TARGET_INSN(NAME, PROTO) \
6208 DEFHOOK_UNDOC (gen_##NAME, "", rtx_insn *, PROTO, NULL)
6209 #include "target-insns.def"
6210 #undef DEF_TARGET_INSN
6212 #define DEF_TARGET_INSN(NAME, PROTO) \
6213 DEFHOOKPOD (code_for_##NAME, "*", enum insn_code, CODE_FOR_nothing)
6214 #include "target-insns.def"
6215 #undef DEF_TARGET_INSN
6217 DEFHOOK
6218 (run_target_selftests,
6219 "If selftests are enabled, run any selftests for this target.",
6220 void, (void),
6221 NULL)
6223 /* Close the 'struct gcc_target' definition. */
6224 HOOK_VECTOR_END (C90_EMPTY_HACK)