1 /* Default target hook functions.
2 Copyright (C) 2003-2024 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
20 /* The migration of target macros to target hooks works as follows:
22 1. Create a target hook that uses the existing target macros to
23 implement the same functionality.
25 2. Convert all the MI files to use the hook instead of the macro.
27 3. Repeat for a majority of the remaining target macros. This will
30 4. Tell target maintainers to start migrating.
32 5. Eventually convert the backends to override the hook instead of
33 defining the macros. This will take some time too.
35 6. TBD when, poison the macros. Unmigrated targets will break at
38 Note that we expect steps 1-3 to be done by the people that
39 understand what the MI does with each macro, and step 5 to be done
40 by the target maintainers for their respective targets.
42 Note that steps 1 and 2 don't have to be done together, but no
43 target can override the new hook until step 2 is complete for it.
45 Once the macros are poisoned, we will revert to the old migration
46 rules - migrate the macro, callers, and targets all at once. This
47 comment can thus be removed at that point. */
50 #define INCLUDE_MEMORY
52 #include "coretypes.h"
57 #include "tree-ssa-alias.h"
58 #include "gimple-expr.h"
64 #include "stringpool.h"
66 #include "tree-ssanames.h"
67 #include "profile-count.h"
71 #include "diagnostic-core.h"
72 #include "fold-const.h"
73 #include "stor-layout.h"
81 #include "common/common-target.h"
88 #include "langhooks.h"
90 #include "function-abi.h"
96 #include "tree-vectorizer.h"
98 #include "case-cfn-macros.h"
101 default_legitimate_address_p (machine_mode mode ATTRIBUTE_UNUSED
,
102 rtx addr ATTRIBUTE_UNUSED
,
103 bool strict ATTRIBUTE_UNUSED
,
104 code_helper ATTRIBUTE_UNUSED
)
106 #ifdef GO_IF_LEGITIMATE_ADDRESS
107 /* Defer to the old implementation using a goto. */
109 return strict_memory_address_p (mode
, addr
);
111 return memory_address_p (mode
, addr
);
118 default_external_libcall (rtx fun ATTRIBUTE_UNUSED
)
120 #ifdef ASM_OUTPUT_EXTERNAL_LIBCALL
121 ASM_OUTPUT_EXTERNAL_LIBCALL (asm_out_file
, fun
);
126 default_unspec_may_trap_p (const_rtx x
, unsigned flags
)
130 /* Any floating arithmetic may trap. */
131 if ((SCALAR_FLOAT_MODE_P (GET_MODE (x
)) && flag_trapping_math
))
134 for (i
= 0; i
< XVECLEN (x
, 0); ++i
)
136 if (may_trap_p_1 (XVECEXP (x
, 0, i
), flags
))
144 default_promote_function_mode (const_tree type ATTRIBUTE_UNUSED
,
146 int *punsignedp ATTRIBUTE_UNUSED
,
147 const_tree funtype ATTRIBUTE_UNUSED
,
148 int for_return ATTRIBUTE_UNUSED
)
150 if (type
!= NULL_TREE
&& for_return
== 2)
151 return promote_mode (type
, mode
, punsignedp
);
156 default_promote_function_mode_always_promote (const_tree type
,
159 const_tree funtype ATTRIBUTE_UNUSED
,
160 int for_return ATTRIBUTE_UNUSED
)
162 return promote_mode (type
, mode
, punsignedp
);
166 default_cc_modes_compatible (machine_mode m1
, machine_mode m2
)
174 default_return_in_memory (const_tree type
,
175 const_tree fntype ATTRIBUTE_UNUSED
)
177 return (TYPE_MODE (type
) == BLKmode
);
181 default_legitimize_address (rtx x
, rtx orig_x ATTRIBUTE_UNUSED
,
182 machine_mode mode ATTRIBUTE_UNUSED
)
188 default_legitimize_address_displacement (rtx
*, rtx
*, poly_int64
,
195 default_const_not_ok_for_debug_p (rtx x
)
197 if (GET_CODE (x
) == UNSPEC
)
203 default_expand_builtin_saveregs (void)
205 error ("%<__builtin_saveregs%> not supported by this target");
210 default_setup_incoming_varargs (cumulative_args_t
,
211 const function_arg_info
&, int *, int)
215 /* The default implementation of TARGET_BUILTIN_SETJMP_FRAME_VALUE. */
218 default_builtin_setjmp_frame_value (void)
220 return virtual_stack_vars_rtx
;
223 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns false. */
226 hook_bool_CUMULATIVE_ARGS_false (cumulative_args_t ca ATTRIBUTE_UNUSED
)
232 default_pretend_outgoing_varargs_named (cumulative_args_t ca ATTRIBUTE_UNUSED
)
234 return (targetm
.calls
.setup_incoming_varargs
235 != default_setup_incoming_varargs
);
239 default_eh_return_filter_mode (void)
241 return targetm
.unwind_word_mode ();
245 default_libgcc_cmp_return_mode (void)
251 default_libgcc_shift_count_mode (void)
257 default_unwind_word_mode (void)
262 /* The default implementation of TARGET_SHIFT_TRUNCATION_MASK. */
264 unsigned HOST_WIDE_INT
265 default_shift_truncation_mask (machine_mode mode
)
267 return SHIFT_COUNT_TRUNCATED
? GET_MODE_UNIT_BITSIZE (mode
) - 1 : 0;
270 /* The default implementation of TARGET_MIN_DIVISIONS_FOR_RECIP_MUL. */
273 default_min_divisions_for_recip_mul (machine_mode mode ATTRIBUTE_UNUSED
)
275 return have_insn_for (DIV
, mode
) ? 3 : 2;
278 /* The default implementation of TARGET_MODE_REP_EXTENDED. */
281 default_mode_rep_extended (scalar_int_mode
, scalar_int_mode
)
286 /* Generic hook that takes a CUMULATIVE_ARGS pointer and returns true. */
289 hook_bool_CUMULATIVE_ARGS_true (cumulative_args_t a ATTRIBUTE_UNUSED
)
294 /* Return machine mode for non-standard suffix
295 or VOIDmode if non-standard suffixes are unsupported. */
297 default_mode_for_suffix (char suffix ATTRIBUTE_UNUSED
)
302 /* Return machine mode for a floating type which is indicated
303 by the given enum tree_index. */
306 default_mode_for_floating_type (enum tree_index ti
)
308 if (ti
== TI_FLOAT_TYPE
)
310 gcc_assert (ti
== TI_DOUBLE_TYPE
|| ti
== TI_LONG_DOUBLE_TYPE
);
314 /* The generic C++ ABI specifies this is a 64-bit value. */
316 default_cxx_guard_type (void)
318 return long_long_integer_type_node
;
321 /* Returns the size of the cookie to use when allocating an array
322 whose elements have the indicated TYPE. Assumes that it is already
323 known that a cookie is needed. */
326 default_cxx_get_cookie_size (tree type
)
330 /* We need to allocate an additional max (sizeof (size_t), alignof
331 (true_type)) bytes. */
335 sizetype_size
= size_in_bytes (sizetype
);
336 type_align
= size_int (TYPE_ALIGN_UNIT (type
));
337 if (tree_int_cst_lt (type_align
, sizetype_size
))
338 cookie_size
= sizetype_size
;
340 cookie_size
= type_align
;
345 /* Returns modified FUNCTION_TYPE for cdtor callabi. */
348 default_cxx_adjust_cdtor_callabi_fntype (tree fntype
)
353 /* Return true if a parameter must be passed by reference. This version
354 of the TARGET_PASS_BY_REFERENCE hook uses just MUST_PASS_IN_STACK. */
357 hook_pass_by_reference_must_pass_in_stack (cumulative_args_t
,
358 const function_arg_info
&arg
)
360 return targetm
.calls
.must_pass_in_stack (arg
);
363 /* Return true if a parameter follows callee copies conventions. This
364 version of the hook is true for all named arguments. */
367 hook_callee_copies_named (cumulative_args_t
, const function_arg_info
&arg
)
372 /* Emit to STREAM the assembler syntax for insn operand X. */
375 default_print_operand (FILE *stream ATTRIBUTE_UNUSED
, rtx x ATTRIBUTE_UNUSED
,
376 int code ATTRIBUTE_UNUSED
)
379 PRINT_OPERAND (stream
, x
, code
);
385 /* Emit to STREAM the assembler syntax for an insn operand whose memory
389 default_print_operand_address (FILE *stream ATTRIBUTE_UNUSED
,
390 machine_mode
/*mode*/,
391 rtx x ATTRIBUTE_UNUSED
)
393 #ifdef PRINT_OPERAND_ADDRESS
394 PRINT_OPERAND_ADDRESS (stream
, x
);
400 /* Return true if CODE is a valid punctuation character for the
401 `print_operand' hook. */
404 default_print_operand_punct_valid_p (unsigned char code ATTRIBUTE_UNUSED
)
406 #ifdef PRINT_OPERAND_PUNCT_VALID_P
407 return PRINT_OPERAND_PUNCT_VALID_P (code
);
413 /* The default implementation of TARGET_MANGLE_ASSEMBLER_NAME. */
415 default_mangle_assembler_name (const char *name ATTRIBUTE_UNUSED
)
417 const char *skipped
= name
+ (*name
== '*' ? 1 : 0);
418 const char *stripped
= targetm
.strip_name_encoding (skipped
);
419 if (*name
!= '*' && user_label_prefix
[0])
420 stripped
= ACONCAT ((user_label_prefix
, stripped
, NULL
));
421 return get_identifier (stripped
);
424 /* The default implementation of TARGET_TRANSLATE_MODE_ATTRIBUTE. */
427 default_translate_mode_attribute (machine_mode mode
)
432 /* True if MODE is valid for the target. By "valid", we mean able to
433 be manipulated in non-trivial ways. In particular, this means all
434 the arithmetic is supported.
436 By default we guess this means that any C type is supported. If
437 we can't map the mode back to a type that would be available in C,
438 then reject it. Special case, here, is the double-word arithmetic
439 supported by optabs.cc. */
442 default_scalar_mode_supported_p (scalar_mode mode
)
444 int precision
= GET_MODE_PRECISION (mode
);
446 switch (GET_MODE_CLASS (mode
))
448 case MODE_PARTIAL_INT
:
450 if (precision
== CHAR_TYPE_SIZE
)
452 if (precision
== SHORT_TYPE_SIZE
)
454 if (precision
== INT_TYPE_SIZE
)
456 if (precision
== LONG_TYPE_SIZE
)
458 if (precision
== LONG_LONG_TYPE_SIZE
)
460 if (precision
== 2 * BITS_PER_WORD
)
465 if (mode
== targetm
.c
.mode_for_floating_type (TI_FLOAT_TYPE
))
467 if (mode
== targetm
.c
.mode_for_floating_type (TI_DOUBLE_TYPE
))
469 if (mode
== targetm
.c
.mode_for_floating_type (TI_LONG_DOUBLE_TYPE
))
473 case MODE_DECIMAL_FLOAT
:
485 /* Return true if libgcc supports floating-point mode MODE (known to
486 be supported as a scalar mode). */
489 default_libgcc_floating_mode_supported_p (scalar_float_mode mode
)
512 /* Return the machine mode to use for the type _FloatN, if EXTENDED is
513 false, or _FloatNx, if EXTENDED is true, or VOIDmode if not
515 opt_scalar_float_mode
516 default_floatn_mode (int n
, bool extended
)
520 opt_scalar_float_mode cand1
, cand2
;
521 scalar_float_mode mode
;
543 /* Those are the only valid _FloatNx types. */
546 if (cand1
.exists (&mode
)
547 && REAL_MODE_FORMAT (mode
)->ieee_bits
> n
548 && targetm
.scalar_mode_supported_p (mode
)
549 && targetm
.libgcc_floating_mode_supported_p (mode
))
551 if (cand2
.exists (&mode
)
552 && REAL_MODE_FORMAT (mode
)->ieee_bits
> n
553 && targetm
.scalar_mode_supported_p (mode
)
554 && targetm
.libgcc_floating_mode_supported_p (mode
))
559 opt_scalar_float_mode cand
;
560 scalar_float_mode mode
;
564 /* Always enable _Float16 if we have basic support for the mode.
565 Targets can control the range and precision of operations on
566 the _Float16 type using TARGET_C_EXCESS_PRECISION. */
593 if (cand
.exists (&mode
)
594 && REAL_MODE_FORMAT (mode
)->ieee_bits
== n
595 && targetm
.scalar_mode_supported_p (mode
)
596 && targetm
.libgcc_floating_mode_supported_p (mode
))
599 return opt_scalar_float_mode ();
602 /* Define this to return true if the _Floatn and _Floatnx built-in functions
603 should implicitly enable the built-in function without the __builtin_ prefix
604 in addition to the normal built-in function with the __builtin_ prefix. The
605 default is to only enable built-in functions without the __builtin_ prefix
606 for the GNU C langauge. The argument FUNC is the enum builtin_in_function
607 id of the function to be enabled. */
610 default_floatn_builtin_p (int func ATTRIBUTE_UNUSED
)
612 static bool first_time_p
= true;
613 static bool c_or_objective_c
;
617 first_time_p
= false;
618 c_or_objective_c
= lang_GNU_C () || lang_GNU_OBJC ();
621 return c_or_objective_c
;
624 /* Make some target macros useable by target-independent code. */
626 targhook_words_big_endian (void)
628 return !!WORDS_BIG_ENDIAN
;
632 targhook_float_words_big_endian (void)
634 return !!FLOAT_WORDS_BIG_ENDIAN
;
637 /* True if the target supports floating-point exceptions and rounding
641 default_float_exceptions_rounding_supported_p (void)
650 /* True if the target supports decimal floating point. */
653 default_decimal_float_supported_p (void)
655 return ENABLE_DECIMAL_FLOAT
;
658 /* True if the target supports fixed-point arithmetic. */
661 default_fixed_point_supported_p (void)
663 return ENABLE_FIXED_POINT
;
666 /* True if the target supports GNU indirect functions. */
669 default_has_ifunc_p (void)
671 return HAVE_GNU_INDIRECT_FUNCTION
;
674 /* Return true if we predict the loop LOOP will be transformed to a
675 low-overhead loop, otherwise return false.
677 By default, false is returned, as this hook's applicability should be
678 verified for each target. Target maintainers should re-define the hook
679 if the target can take advantage of it. */
682 default_predict_doloop_p (class loop
*loop ATTRIBUTE_UNUSED
)
687 /* By default, just use the input MODE itself. */
690 default_preferred_doloop_mode (machine_mode mode
)
695 /* NULL if INSN insn is valid within a low-overhead loop, otherwise returns
698 This function checks whether a given INSN is valid within a low-overhead
699 loop. If INSN is invalid it returns the reason for that, otherwise it
700 returns NULL. A called function may clobber any special registers required
701 for low-overhead looping. Additionally, some targets (eg, PPC) use the count
702 register for branch on table instructions. We reject the doloop pattern in
706 default_invalid_within_doloop (const rtx_insn
*insn
)
709 return "Function call in loop.";
711 if (tablejump_p (insn
, NULL
, NULL
) || computed_jump_p (insn
))
712 return "Computed branch in the loop.";
717 /* Mapping of builtin functions to vectorized variants. */
720 default_builtin_vectorized_function (unsigned int, tree
, tree
)
725 /* Mapping of target builtin functions to vectorized variants. */
728 default_builtin_md_vectorized_function (tree
, tree
, tree
)
733 /* Default vectorizer cost model values. */
736 default_builtin_vectorization_cost (enum vect_cost_for_stmt type_of_cost
,
738 int misalign ATTRIBUTE_UNUSED
)
740 switch (type_of_cost
)
750 case cond_branch_not_taken
:
752 case vec_promote_demote
:
756 case unaligned_store
:
759 case cond_branch_taken
:
763 return estimated_poly_value (TYPE_VECTOR_SUBPARTS (vectype
)) - 1;
773 default_builtin_reciprocal (tree
)
779 default_emit_support_tinfos (emit_support_tinfos_callback
)
784 hook_bool_CUMULATIVE_ARGS_arg_info_false (cumulative_args_t
,
785 const function_arg_info
&)
791 hook_bool_CUMULATIVE_ARGS_arg_info_true (cumulative_args_t
,
792 const function_arg_info
&)
798 hook_int_CUMULATIVE_ARGS_arg_info_0 (cumulative_args_t
,
799 const function_arg_info
&)
805 hook_void_CUMULATIVE_ARGS (cumulative_args_t
)
810 hook_void_CUMULATIVE_ARGS_tree (cumulative_args_t ca ATTRIBUTE_UNUSED
,
811 tree ATTRIBUTE_UNUSED
)
816 hook_void_CUMULATIVE_ARGS_rtx_tree (cumulative_args_t
, rtx
, tree
)
820 /* Default implementation of TARGET_PUSH_ARGUMENT. */
823 default_push_argument (unsigned int)
826 return !ACCUMULATE_OUTGOING_ARGS
;
833 default_function_arg_advance (cumulative_args_t
, const function_arg_info
&)
838 /* Default implementation of TARGET_FUNCTION_ARG_OFFSET. */
841 default_function_arg_offset (machine_mode
, const_tree
)
846 /* Default implementation of TARGET_FUNCTION_ARG_PADDING: usually pad
847 upward, but pad short args downward on big-endian machines. */
850 default_function_arg_padding (machine_mode mode
, const_tree type
)
852 if (!BYTES_BIG_ENDIAN
)
855 unsigned HOST_WIDE_INT size
;
858 if (!type
|| TREE_CODE (TYPE_SIZE (type
)) != INTEGER_CST
)
860 size
= int_size_in_bytes (type
);
863 /* Targets with variable-sized modes must override this hook
864 and handle variable-sized modes explicitly. */
865 size
= GET_MODE_SIZE (mode
).to_constant ();
867 if (size
< (PARM_BOUNDARY
/ BITS_PER_UNIT
))
874 default_function_arg (cumulative_args_t
, const function_arg_info
&)
880 default_function_incoming_arg (cumulative_args_t
, const function_arg_info
&)
886 default_function_arg_boundary (machine_mode mode ATTRIBUTE_UNUSED
,
887 const_tree type ATTRIBUTE_UNUSED
)
889 return PARM_BOUNDARY
;
893 default_function_arg_round_boundary (machine_mode mode ATTRIBUTE_UNUSED
,
894 const_tree type ATTRIBUTE_UNUSED
)
896 return PARM_BOUNDARY
;
900 hook_void_bitmap (bitmap regs ATTRIBUTE_UNUSED
)
905 hook_invalid_arg_for_unprototyped_fn (
906 const_tree typelist ATTRIBUTE_UNUSED
,
907 const_tree funcdecl ATTRIBUTE_UNUSED
,
908 const_tree val ATTRIBUTE_UNUSED
)
913 /* Initialize the stack protection decls. */
915 /* Stack protection related decls living in libgcc. */
916 static GTY(()) tree stack_chk_guard_decl
;
919 default_stack_protect_guard (void)
921 tree t
= stack_chk_guard_decl
;
927 t
= build_decl (UNKNOWN_LOCATION
,
928 VAR_DECL
, get_identifier ("__stack_chk_guard"),
932 DECL_EXTERNAL (t
) = 1;
934 TREE_THIS_VOLATILE (t
) = 1;
935 DECL_ARTIFICIAL (t
) = 1;
936 DECL_IGNORED_P (t
) = 1;
938 /* Do not share RTL as the declaration is visible outside of
941 RTX_FLAG (x
, used
) = 1;
943 stack_chk_guard_decl
= t
;
949 static GTY(()) tree stack_chk_fail_decl
;
952 default_external_stack_protect_fail (void)
954 tree t
= stack_chk_fail_decl
;
958 t
= build_function_type_list (void_type_node
, NULL_TREE
);
959 t
= build_decl (UNKNOWN_LOCATION
,
960 FUNCTION_DECL
, get_identifier ("__stack_chk_fail"), t
);
963 DECL_EXTERNAL (t
) = 1;
965 TREE_THIS_VOLATILE (t
) = 1;
966 TREE_NOTHROW (t
) = 1;
967 DECL_ARTIFICIAL (t
) = 1;
968 DECL_IGNORED_P (t
) = 1;
969 DECL_VISIBILITY (t
) = VISIBILITY_DEFAULT
;
970 DECL_VISIBILITY_SPECIFIED (t
) = 1;
972 stack_chk_fail_decl
= t
;
975 return build_call_expr (t
, 0);
979 default_hidden_stack_protect_fail (void)
981 #ifndef HAVE_GAS_HIDDEN
982 return default_external_stack_protect_fail ();
984 tree t
= stack_chk_fail_decl
;
987 return default_external_stack_protect_fail ();
991 t
= build_function_type_list (void_type_node
, NULL_TREE
);
992 t
= build_decl (UNKNOWN_LOCATION
, FUNCTION_DECL
,
993 get_identifier ("__stack_chk_fail_local"), t
);
996 DECL_EXTERNAL (t
) = 1;
998 TREE_THIS_VOLATILE (t
) = 1;
999 TREE_NOTHROW (t
) = 1;
1000 DECL_ARTIFICIAL (t
) = 1;
1001 DECL_IGNORED_P (t
) = 1;
1002 DECL_VISIBILITY_SPECIFIED (t
) = 1;
1003 DECL_VISIBILITY (t
) = VISIBILITY_HIDDEN
;
1005 stack_chk_fail_decl
= t
;
1008 return build_call_expr (t
, 0);
1013 hook_bool_const_rtx_commutative_p (const_rtx x
,
1014 int outer_code ATTRIBUTE_UNUSED
)
1016 return COMMUTATIVE_P (x
);
1020 default_function_value (const_tree ret_type ATTRIBUTE_UNUSED
,
1021 const_tree fn_decl_or_type
,
1022 bool outgoing ATTRIBUTE_UNUSED
)
1024 /* The old interface doesn't handle receiving the function type. */
1026 && !DECL_P (fn_decl_or_type
))
1027 fn_decl_or_type
= NULL
;
1029 #ifdef FUNCTION_VALUE
1030 return FUNCTION_VALUE (ret_type
, fn_decl_or_type
);
1037 default_libcall_value (machine_mode mode ATTRIBUTE_UNUSED
,
1038 const_rtx fun ATTRIBUTE_UNUSED
)
1040 #ifdef LIBCALL_VALUE
1041 return LIBCALL_VALUE (MACRO_MODE (mode
));
1047 /* The default hook for TARGET_FUNCTION_VALUE_REGNO_P. */
1050 default_function_value_regno_p (const unsigned int regno ATTRIBUTE_UNUSED
)
1052 #ifdef FUNCTION_VALUE_REGNO_P
1053 return FUNCTION_VALUE_REGNO_P (regno
);
1059 /* Choose the mode and rtx to use to zero REGNO, storing tem in PMODE and
1060 PREGNO_RTX and returning TRUE if successful, otherwise returning FALSE. If
1061 the natural mode for REGNO doesn't work, attempt to group it with subsequent
1062 adjacent registers set in TOZERO. */
1065 zcur_select_mode_rtx (unsigned int regno
, machine_mode
*pmode
,
1066 rtx
*pregno_rtx
, HARD_REG_SET tozero
)
1068 rtx regno_rtx
= regno_reg_rtx
[regno
];
1069 machine_mode mode
= GET_MODE (regno_rtx
);
1071 /* If the natural mode doesn't work, try some wider mode. */
1072 if (!targetm
.hard_regno_mode_ok (regno
, mode
))
1076 !found
&& nregs
<= hard_regno_max_nregs
1077 && regno
+ nregs
<= FIRST_PSEUDO_REGISTER
1078 && TEST_HARD_REG_BIT (tozero
,
1082 mode
= choose_hard_reg_mode (regno
, nregs
, 0);
1083 if (mode
== E_VOIDmode
)
1085 gcc_checking_assert (targetm
.hard_regno_mode_ok (regno
, mode
));
1086 regno_rtx
= gen_rtx_REG (mode
, regno
);
1094 *pregno_rtx
= regno_rtx
;
1098 /* The default hook for TARGET_ZERO_CALL_USED_REGS. */
1101 default_zero_call_used_regs (HARD_REG_SET need_zeroed_hardregs
)
1103 gcc_assert (!hard_reg_set_empty_p (need_zeroed_hardregs
));
1105 HARD_REG_SET failed
;
1106 CLEAR_HARD_REG_SET (failed
);
1107 bool progress
= false;
1109 /* First, try to zero each register in need_zeroed_hardregs by
1110 loading a zero into it, taking note of any failures in
1112 for (unsigned int regno
= 0; regno
< FIRST_PSEUDO_REGISTER
; regno
++)
1113 if (TEST_HARD_REG_BIT (need_zeroed_hardregs
, regno
))
1115 rtx_insn
*last_insn
= get_last_insn ();
1119 if (!zcur_select_mode_rtx (regno
, &mode
, ®no_rtx
,
1120 need_zeroed_hardregs
))
1122 SET_HARD_REG_BIT (failed
, regno
);
1126 rtx zero
= CONST0_RTX (mode
);
1127 rtx_insn
*insn
= emit_move_insn (regno_rtx
, zero
);
1128 if (!valid_insn_p (insn
))
1130 SET_HARD_REG_BIT (failed
, regno
);
1131 delete_insns_since (last_insn
);
1136 regno
+= hard_regno_nregs (regno
, mode
) - 1;
1140 /* Now retry with copies from zeroed registers, as long as we've
1141 made some PROGRESS, and registers remain to be zeroed in
1143 while (progress
&& !hard_reg_set_empty_p (failed
))
1145 HARD_REG_SET retrying
= failed
;
1147 CLEAR_HARD_REG_SET (failed
);
1150 for (unsigned int regno
= 0; regno
< FIRST_PSEUDO_REGISTER
; regno
++)
1151 if (TEST_HARD_REG_BIT (retrying
, regno
))
1156 /* This might select registers we've already zeroed. If grouping
1157 with them is what it takes to get regno zeroed, so be it. */
1158 if (!zcur_select_mode_rtx (regno
, &mode
, ®no_rtx
,
1159 need_zeroed_hardregs
))
1161 SET_HARD_REG_BIT (failed
, regno
);
1165 bool success
= false;
1166 /* Look for a source. */
1167 for (unsigned int src
= 0; src
< FIRST_PSEUDO_REGISTER
; src
++)
1169 /* If SRC hasn't been zeroed (yet?), skip it. */
1170 if (! TEST_HARD_REG_BIT (need_zeroed_hardregs
, src
))
1172 if (TEST_HARD_REG_BIT (retrying
, src
))
1175 /* Check that SRC can hold MODE, and that any other
1176 registers needed to hold MODE in SRC have also been
1178 if (!targetm
.hard_regno_mode_ok (src
, mode
))
1180 unsigned n
= targetm
.hard_regno_nregs (src
, mode
);
1182 for (unsigned i
= 1; ok
&& i
< n
; i
++)
1183 ok
= (TEST_HARD_REG_BIT (need_zeroed_hardregs
, src
+ i
)
1184 && !TEST_HARD_REG_BIT (retrying
, src
+ i
));
1188 /* SRC is usable, try to copy from it. */
1189 rtx_insn
*last_insn
= get_last_insn ();
1190 rtx src_rtx
= gen_rtx_REG (mode
, src
);
1191 rtx_insn
*insn
= emit_move_insn (regno_rtx
, src_rtx
);
1192 if (!valid_insn_p (insn
))
1193 /* It didn't work, remove any inserts. We'll look
1195 delete_insns_since (last_insn
);
1198 /* We're done for REGNO. */
1204 /* If nothing worked for REGNO this round, mark it to be
1205 retried if we get another round. */
1207 SET_HARD_REG_BIT (failed
, regno
);
1210 /* Take note so as to enable another round if needed. */
1212 regno
+= hard_regno_nregs (regno
, mode
) - 1;
1217 /* If any register remained, report it. */
1220 static bool issued_error
;
1223 const char *name
= NULL
;
1224 for (unsigned int i
= 0; zero_call_used_regs_opts
[i
].name
!= NULL
;
1226 if (flag_zero_call_used_regs
== zero_call_used_regs_opts
[i
].flag
)
1228 name
= zero_call_used_regs_opts
[i
].name
;
1235 issued_error
= true;
1236 sorry ("argument %qs is not supported for %qs on this target",
1237 name
, "-fzero-call-used-regs");
1241 return need_zeroed_hardregs
;
1245 default_internal_arg_pointer (void)
1247 /* If the reg that the virtual arg pointer will be translated into is
1248 not a fixed reg or is the stack pointer, make a copy of the virtual
1249 arg pointer, and address parms via the copy. The frame pointer is
1250 considered fixed even though it is not marked as such. */
1251 if ((ARG_POINTER_REGNUM
== STACK_POINTER_REGNUM
1252 || ! (fixed_regs
[ARG_POINTER_REGNUM
]
1253 || ARG_POINTER_REGNUM
== FRAME_POINTER_REGNUM
)))
1254 return copy_to_reg (virtual_incoming_args_rtx
);
1256 return virtual_incoming_args_rtx
;
1260 default_static_chain (const_tree
ARG_UNUSED (fndecl_or_type
), bool incoming_p
)
1264 #ifdef STATIC_CHAIN_INCOMING_REGNUM
1265 return gen_rtx_REG (Pmode
, STATIC_CHAIN_INCOMING_REGNUM
);
1269 #ifdef STATIC_CHAIN_REGNUM
1270 return gen_rtx_REG (Pmode
, STATIC_CHAIN_REGNUM
);
1274 static bool issued_error
;
1277 issued_error
= true;
1278 sorry ("nested functions not supported on this target");
1281 /* It really doesn't matter what we return here, so long at it
1282 doesn't cause the rest of the compiler to crash. */
1283 return gen_rtx_MEM (Pmode
, stack_pointer_rtx
);
1288 default_trampoline_init (rtx
ARG_UNUSED (m_tramp
), tree
ARG_UNUSED (t_func
),
1289 rtx
ARG_UNUSED (r_chain
))
1291 sorry ("nested function trampolines not supported on this target");
1295 default_return_pops_args (tree
, tree
, poly_int64
)
1301 default_ira_change_pseudo_allocno_class (int regno ATTRIBUTE_UNUSED
,
1303 reg_class_t best_cl ATTRIBUTE_UNUSED
)
1309 default_lra_p (void)
1315 default_register_priority (int hard_regno ATTRIBUTE_UNUSED
)
1321 default_register_usage_leveling_p (void)
1327 default_different_addr_displacement_p (void)
1333 default_secondary_reload (bool in_p ATTRIBUTE_UNUSED
, rtx x ATTRIBUTE_UNUSED
,
1334 reg_class_t reload_class_i ATTRIBUTE_UNUSED
,
1335 machine_mode reload_mode ATTRIBUTE_UNUSED
,
1336 secondary_reload_info
*sri
)
1338 enum reg_class rclass
= NO_REGS
;
1339 enum reg_class reload_class
= (enum reg_class
) reload_class_i
;
1341 if (sri
->prev_sri
&& sri
->prev_sri
->t_icode
!= CODE_FOR_nothing
)
1343 sri
->icode
= sri
->prev_sri
->t_icode
;
1346 #ifdef SECONDARY_INPUT_RELOAD_CLASS
1348 rclass
= SECONDARY_INPUT_RELOAD_CLASS (reload_class
,
1349 MACRO_MODE (reload_mode
), x
);
1351 #ifdef SECONDARY_OUTPUT_RELOAD_CLASS
1353 rclass
= SECONDARY_OUTPUT_RELOAD_CLASS (reload_class
,
1354 MACRO_MODE (reload_mode
), x
);
1356 if (rclass
!= NO_REGS
)
1358 enum insn_code icode
1359 = direct_optab_handler (in_p
? reload_in_optab
: reload_out_optab
,
1362 if (icode
!= CODE_FOR_nothing
1363 && !insn_operand_matches (icode
, in_p
, x
))
1364 icode
= CODE_FOR_nothing
;
1365 else if (icode
!= CODE_FOR_nothing
)
1367 const char *insn_constraint
, *scratch_constraint
;
1368 enum reg_class insn_class
, scratch_class
;
1370 gcc_assert (insn_data
[(int) icode
].n_operands
== 3);
1371 insn_constraint
= insn_data
[(int) icode
].operand
[!in_p
].constraint
;
1372 if (!*insn_constraint
)
1373 insn_class
= ALL_REGS
;
1378 gcc_assert (*insn_constraint
== '=');
1381 insn_class
= (reg_class_for_constraint
1382 (lookup_constraint (insn_constraint
)));
1383 gcc_assert (insn_class
!= NO_REGS
);
1386 scratch_constraint
= insn_data
[(int) icode
].operand
[2].constraint
;
1387 /* The scratch register's constraint must start with "=&",
1388 except for an input reload, where only "=" is necessary,
1389 and where it might be beneficial to re-use registers from
1391 gcc_assert (scratch_constraint
[0] == '='
1392 && (in_p
|| scratch_constraint
[1] == '&'));
1393 scratch_constraint
++;
1394 if (*scratch_constraint
== '&')
1395 scratch_constraint
++;
1396 scratch_class
= (reg_class_for_constraint
1397 (lookup_constraint (scratch_constraint
)));
1399 if (reg_class_subset_p (reload_class
, insn_class
))
1401 gcc_assert (scratch_class
== rclass
);
1405 rclass
= insn_class
;
1408 if (rclass
== NO_REGS
)
1411 sri
->t_icode
= icode
;
1416 /* The default implementation of TARGET_SECONDARY_MEMORY_NEEDED_MODE. */
1419 default_secondary_memory_needed_mode (machine_mode mode
)
1421 if (!targetm
.lra_p ()
1422 && known_lt (GET_MODE_BITSIZE (mode
), BITS_PER_WORD
)
1423 && INTEGRAL_MODE_P (mode
))
1424 return mode_for_size (BITS_PER_WORD
, GET_MODE_CLASS (mode
), 0).require ();
1428 /* By default, if flag_pic is true, then neither local nor global relocs
1429 should be placed in readonly memory. */
1432 default_reloc_rw_mask (void)
1434 return flag_pic
? 3 : 0;
1437 /* By default, address diff vectors are generated
1438 for jump tables when flag_pic is true. */
1441 default_generate_pic_addr_diff_vec (void)
1446 /* Record an element in the table of global constructors. SYMBOL is
1447 a SYMBOL_REF of the function to be called; PRIORITY is a number
1448 between 0 and MAX_INIT_PRIORITY. */
1451 default_asm_out_constructor (rtx symbol ATTRIBUTE_UNUSED
,
1452 int priority ATTRIBUTE_UNUSED
)
1454 sorry ("global constructors not supported on this target");
1457 /* Likewise for global destructors. */
1460 default_asm_out_destructor (rtx symbol ATTRIBUTE_UNUSED
,
1461 int priority ATTRIBUTE_UNUSED
)
1463 sorry ("global destructors not supported on this target");
1466 /* By default, do no modification. */
1467 tree
default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED
,
1473 /* The default implementation of TARGET_STATIC_RTX_ALIGNMENT. */
1476 default_static_rtx_alignment (machine_mode mode
)
1478 return GET_MODE_ALIGNMENT (mode
);
1481 /* The default implementation of TARGET_CONSTANT_ALIGNMENT. */
1484 default_constant_alignment (const_tree
, HOST_WIDE_INT align
)
1489 /* An implementation of TARGET_CONSTANT_ALIGNMENT that aligns strings
1490 to at least BITS_PER_WORD but otherwise makes no changes. */
1493 constant_alignment_word_strings (const_tree exp
, HOST_WIDE_INT align
)
1495 if (TREE_CODE (exp
) == STRING_CST
)
1496 return MAX (align
, BITS_PER_WORD
);
1500 /* Default to natural alignment for vector types, bounded by
1501 MAX_OFILE_ALIGNMENT. */
1504 default_vector_alignment (const_tree type
)
1506 unsigned HOST_WIDE_INT align
= MAX_OFILE_ALIGNMENT
;
1507 tree size
= TYPE_SIZE (type
);
1508 if (tree_fits_uhwi_p (size
))
1509 align
= tree_to_uhwi (size
);
1510 if (align
>= MAX_OFILE_ALIGNMENT
)
1511 return MAX_OFILE_ALIGNMENT
;
1512 return MAX (align
, GET_MODE_ALIGNMENT (TYPE_MODE (type
)));
1515 /* The default implementation of
1516 TARGET_VECTORIZE_PREFERRED_VECTOR_ALIGNMENT. */
1519 default_preferred_vector_alignment (const_tree type
)
1521 return TYPE_ALIGN (type
);
1524 /* The default implementation of
1525 TARGET_VECTORIZE_PREFERRED_DIV_AS_SHIFTS_OVER_MULT. */
1528 default_preferred_div_as_shifts_over_mult (const_tree type
)
1530 return !can_mult_highpart_p (TYPE_MODE (type
), TYPE_UNSIGNED (type
));
1533 /* By default assume vectors of element TYPE require a multiple of the natural
1534 alignment of TYPE. TYPE is naturally aligned if IS_PACKED is false. */
1536 default_builtin_vector_alignment_reachable (const_tree
/*type*/, bool is_packed
)
1541 /* By default, assume that a target supports any factor of misalignment
1542 memory access if it supports movmisalign patten.
1543 is_packed is true if the memory access is defined in a packed struct. */
1545 default_builtin_support_vector_misalignment (machine_mode mode
,
1553 if (optab_handler (movmisalign_optab
, mode
) != CODE_FOR_nothing
)
1558 /* By default, only attempt to parallelize bitwise operations, and
1559 possibly adds/subtracts using bit-twiddling. */
1562 default_preferred_simd_mode (scalar_mode
)
1567 /* By default do not split reductions further. */
1570 default_split_reduction (machine_mode mode
)
1575 /* By default only the preferred vector mode is tried. */
1578 default_autovectorize_vector_modes (vector_modes
*, bool)
1583 /* The default implementation of TARGET_VECTORIZE_RELATED_MODE. */
1586 default_vectorize_related_mode (machine_mode vector_mode
,
1587 scalar_mode element_mode
,
1590 machine_mode result_mode
;
1591 if ((maybe_ne (nunits
, 0U)
1592 || multiple_p (GET_MODE_SIZE (vector_mode
),
1593 GET_MODE_SIZE (element_mode
), &nunits
))
1594 && mode_for_vector (element_mode
, nunits
).exists (&result_mode
)
1595 && VECTOR_MODE_P (result_mode
)
1596 && targetm
.vector_mode_supported_p (result_mode
))
1599 return opt_machine_mode ();
1602 /* By default a vector of integers is used as a mask. */
1605 default_get_mask_mode (machine_mode mode
)
1607 return related_int_vector_mode (mode
);
1610 /* By default consider masked stores to be expensive. */
1613 default_conditional_operation_is_expensive (unsigned ifn
)
1615 return ifn
== IFN_MASK_STORE
;
1618 /* By default consider masked stores to be expensive. */
1621 default_empty_mask_is_expensive (unsigned ifn
)
1623 return ifn
== IFN_MASK_STORE
;
1626 /* By default, the cost model accumulates three separate costs (prologue,
1627 loop body, and epilogue) for a vectorized loop or block. So allocate an
1628 array of three unsigned ints, set it to zero, and return its address. */
1631 default_vectorize_create_costs (vec_info
*vinfo
, bool costing_for_scalar
)
1633 return new vector_costs (vinfo
, costing_for_scalar
);
1636 /* Determine whether or not a pointer mode is valid. Assume defaults
1637 of ptr_mode or Pmode - can be overridden. */
1639 default_valid_pointer_mode (scalar_int_mode mode
)
1641 return (mode
== ptr_mode
|| mode
== Pmode
);
1644 /* Determine whether the memory reference specified by REF may alias
1645 the C libraries errno location. */
1647 default_ref_may_alias_errno (ao_ref
*ref
)
1649 tree base
= ao_ref_base (ref
);
1650 /* The default implementation assumes the errno location is
1651 a declaration of type int or is always accessed via a
1652 pointer to int. We assume that accesses to errno are
1653 not deliberately obfuscated (even in conforming ways). */
1654 if (TYPE_UNSIGNED (TREE_TYPE (base
))
1655 || TYPE_MODE (TREE_TYPE (base
)) != TYPE_MODE (integer_type_node
))
1657 /* The default implementation assumes an errno location declaration
1658 is never defined in the current compilation unit and may not be
1659 aliased by a local variable. */
1661 && DECL_EXTERNAL (base
)
1662 && !TREE_STATIC (base
))
1664 else if (TREE_CODE (base
) == MEM_REF
1665 && TREE_CODE (TREE_OPERAND (base
, 0)) == SSA_NAME
)
1667 struct ptr_info_def
*pi
= SSA_NAME_PTR_INFO (TREE_OPERAND (base
, 0));
1668 return !pi
|| pi
->pt
.anything
|| pi
->pt
.nonlocal
;
1673 /* Return the mode for a pointer to a given ADDRSPACE,
1674 defaulting to ptr_mode for all address spaces. */
1677 default_addr_space_pointer_mode (addr_space_t addrspace ATTRIBUTE_UNUSED
)
1682 /* Return the mode for an address in a given ADDRSPACE,
1683 defaulting to Pmode for all address spaces. */
1686 default_addr_space_address_mode (addr_space_t addrspace ATTRIBUTE_UNUSED
)
1691 /* Named address space version of valid_pointer_mode.
1692 To match the above, the same modes apply to all address spaces. */
1695 default_addr_space_valid_pointer_mode (scalar_int_mode mode
,
1696 addr_space_t as ATTRIBUTE_UNUSED
)
1698 return targetm
.valid_pointer_mode (mode
);
1701 /* Some places still assume that all pointer or address modes are the
1702 standard Pmode and ptr_mode. These optimizations become invalid if
1703 the target actually supports multiple different modes. For now,
1704 we disable such optimizations on such targets, using this function. */
1707 target_default_pointer_address_modes_p (void)
1709 if (targetm
.addr_space
.address_mode
!= default_addr_space_address_mode
)
1711 if (targetm
.addr_space
.pointer_mode
!= default_addr_space_pointer_mode
)
1717 /* Named address space version of legitimate_address_p.
1718 By default, all address spaces have the same form. */
1721 default_addr_space_legitimate_address_p (machine_mode mode
, rtx mem
,
1723 addr_space_t as ATTRIBUTE_UNUSED
,
1726 return targetm
.legitimate_address_p (mode
, mem
, strict
, code
);
1729 /* Named address space version of LEGITIMIZE_ADDRESS.
1730 By default, all address spaces have the same form. */
1733 default_addr_space_legitimize_address (rtx x
, rtx oldx
, machine_mode mode
,
1734 addr_space_t as ATTRIBUTE_UNUSED
)
1736 return targetm
.legitimize_address (x
, oldx
, mode
);
1739 /* The default hook for determining if one named address space is a subset of
1740 another and to return which address space to use as the common address
1744 default_addr_space_subset_p (addr_space_t subset
, addr_space_t superset
)
1746 return (subset
== superset
);
1749 /* The default hook for determining if 0 within a named address
1750 space is a valid address. */
1753 default_addr_space_zero_address_valid (addr_space_t as ATTRIBUTE_UNUSED
)
1758 /* The default hook for debugging the address space is to return the
1759 address space number to indicate DW_AT_address_class. */
1761 default_addr_space_debug (addr_space_t as
)
1766 /* The default hook implementation for TARGET_ADDR_SPACE_DIAGNOSE_USAGE.
1767 Don't complain about any address space. */
1770 default_addr_space_diagnose_usage (addr_space_t
, location_t
)
1775 /* The default hook for TARGET_ADDR_SPACE_CONVERT. This hook should never be
1776 called for targets with only a generic address space. */
1779 default_addr_space_convert (rtx op ATTRIBUTE_UNUSED
,
1780 tree from_type ATTRIBUTE_UNUSED
,
1781 tree to_type ATTRIBUTE_UNUSED
)
1786 /* The defualt implementation of TARGET_HARD_REGNO_NREGS. */
1789 default_hard_regno_nregs (unsigned int, machine_mode mode
)
1791 /* Targets with variable-sized modes must provide their own definition
1793 return CEIL (GET_MODE_SIZE (mode
).to_constant (), UNITS_PER_WORD
);
1797 default_hard_regno_scratch_ok (unsigned int regno ATTRIBUTE_UNUSED
)
1802 /* The default implementation of TARGET_MODE_DEPENDENT_ADDRESS_P. */
1805 default_mode_dependent_address_p (const_rtx addr ATTRIBUTE_UNUSED
,
1806 addr_space_t addrspace ATTRIBUTE_UNUSED
)
1811 extern bool default_new_address_profitable_p (rtx
, rtx
);
1814 /* The default implementation of TARGET_NEW_ADDRESS_PROFITABLE_P. */
1817 default_new_address_profitable_p (rtx memref ATTRIBUTE_UNUSED
,
1818 rtx_insn
*insn ATTRIBUTE_UNUSED
,
1819 rtx new_addr ATTRIBUTE_UNUSED
)
1825 default_target_option_valid_attribute_p (tree
ARG_UNUSED (fndecl
),
1826 tree
ARG_UNUSED (name
),
1827 tree
ARG_UNUSED (args
),
1828 int ARG_UNUSED (flags
))
1830 warning (OPT_Wattributes
,
1831 "%<target%> attribute is not supported on this machine");
1837 default_target_option_valid_version_attribute_p (tree
ARG_UNUSED (fndecl
),
1838 tree
ARG_UNUSED (name
),
1839 tree
ARG_UNUSED (args
),
1840 int ARG_UNUSED (flags
))
1842 warning (OPT_Wattributes
,
1843 "%<target_version%> attribute is not supported on this machine");
1849 default_target_option_pragma_parse (tree
ARG_UNUSED (args
),
1850 tree
ARG_UNUSED (pop_target
))
1852 /* If args is NULL the caller is handle_pragma_pop_options (). In that case,
1853 emit no warning because "#pragma GCC pop_target" is valid on targets that
1854 do not have the "target" pragma. */
1856 warning (OPT_Wpragmas
,
1857 "%<#pragma GCC target%> is not supported for this machine");
1863 default_target_can_inline_p (tree caller
, tree callee
)
1865 tree callee_opts
= DECL_FUNCTION_SPECIFIC_TARGET (callee
);
1866 tree caller_opts
= DECL_FUNCTION_SPECIFIC_TARGET (caller
);
1868 callee_opts
= target_option_default_node
;
1870 caller_opts
= target_option_default_node
;
1872 /* If both caller and callee have attributes, assume that if the
1873 pointer is different, the two functions have different target
1874 options since build_target_option_node uses a hash table for the
1876 return callee_opts
== caller_opts
;
1879 /* By default, return false to not need to collect any target information
1880 for inlining. Target maintainer should re-define the hook if the
1881 target want to take advantage of it. */
1884 default_need_ipa_fn_target_info (const_tree
, unsigned int &)
1890 default_update_ipa_fn_target_info (unsigned int &, const gimple
*)
1895 /* If the machine does not have a case insn that compares the bounds,
1896 this means extra overhead for dispatch tables, which raises the
1897 threshold for using them. */
1900 default_case_values_threshold (void)
1902 return (targetm
.have_casesi () ? 4 : 5);
1906 default_have_conditional_execution (void)
1908 return HAVE_conditional_execution
;
1912 default_have_ccmp (void)
1914 return targetm
.gen_ccmp_first
!= NULL
;
1917 /* By default we assume that c99 functions are present at the runtime,
1918 but sincos is not. */
1920 default_libc_has_function (enum function_class fn_class
,
1921 tree type ATTRIBUTE_UNUSED
)
1923 if (fn_class
== function_c94
1924 || fn_class
== function_c99_misc
1925 || fn_class
== function_c99_math_complex
)
1931 /* By default assume that libc has not a fast implementation. */
1934 default_libc_has_fast_function (int fcode ATTRIBUTE_UNUSED
)
1940 gnu_libc_has_function (enum function_class fn_class ATTRIBUTE_UNUSED
,
1941 tree type ATTRIBUTE_UNUSED
)
1947 no_c99_libc_has_function (enum function_class fn_class ATTRIBUTE_UNUSED
,
1948 tree type ATTRIBUTE_UNUSED
)
1953 /* Assume some c99 functions are present at the runtime including sincos. */
1955 bsd_libc_has_function (enum function_class fn_class
,
1956 tree type ATTRIBUTE_UNUSED
)
1958 if (fn_class
== function_c94
1959 || fn_class
== function_c99_misc
1960 || fn_class
== function_sincos
)
1966 /* By default, -fhardened will add -D_FORTIFY_SOURCE=2. */
1969 default_fortify_source_default_level ()
1975 default_libm_function_max_error (unsigned, machine_mode
, bool)
1981 glibc_linux_libm_function_max_error (unsigned cfn
, machine_mode mode
,
1985 https://www.gnu.org/software/libc/manual/2.22/html_node/Errors-in-Math-Functions.html
1986 https://www.gnu.org/software/libc/manual/html_node/Errors-in-Math-Functions.html
1987 with usual values recorded here and significant outliers handled in
1988 target CPU specific overriders. The tables only record default
1989 rounding to nearest, for -frounding-math let's add some extra ulps.
1990 For boundary_p values (say finite results outside of [-1.,1.] for
1991 sin/cos, or [-0.,+Inf] for sqrt etc. let's use custom random testers. */
1992 int rnd
= flag_rounding_math
? 4 : 0;
1993 bool sf
= (REAL_MODE_FORMAT (mode
) == &ieee_single_format
1994 || REAL_MODE_FORMAT (mode
) == &mips_single_format
1995 || REAL_MODE_FORMAT (mode
) == &motorola_single_format
);
1996 bool df
= (REAL_MODE_FORMAT (mode
) == &ieee_double_format
1997 || REAL_MODE_FORMAT (mode
) == &mips_double_format
1998 || REAL_MODE_FORMAT (mode
) == &motorola_double_format
);
1999 bool xf
= (REAL_MODE_FORMAT (mode
) == &ieee_extended_intel_96_format
2000 || REAL_MODE_FORMAT (mode
) == &ieee_extended_intel_128_format
2001 || REAL_MODE_FORMAT (mode
) == &ieee_extended_motorola_format
);
2002 bool tf
= (REAL_MODE_FORMAT (mode
) == &ieee_quad_format
2003 || REAL_MODE_FORMAT (mode
) == &mips_quad_format
);
2010 /* https://gcc.gnu.org/pipermail/gcc-patches/2023-April/616595.html */
2012 if (sf
|| df
|| xf
|| tf
)
2017 /* cos is generally errors like sin, but far more arches have 2ulps
2019 if (!boundary_p
&& df
)
2026 https://sourceware.org/pipermail/gcc-patches/2023-April/616315.html
2027 seems default rounding sin/cos stay strictly in [-1.,1.] range,
2028 with rounding to infinity it can be 1ulp larger/smaller. */
2029 return flag_rounding_math
? 1 : 0;
2039 return default_libm_function_max_error (cfn
, mode
, boundary_p
);
2043 default_builtin_tm_load_store (tree
ARG_UNUSED (type
))
2048 /* Compute cost of moving registers to/from memory. */
2051 default_memory_move_cost (machine_mode mode ATTRIBUTE_UNUSED
,
2052 reg_class_t rclass ATTRIBUTE_UNUSED
,
2053 bool in ATTRIBUTE_UNUSED
)
2055 #ifndef MEMORY_MOVE_COST
2056 return (4 + memory_move_secondary_cost (mode
, (enum reg_class
) rclass
, in
));
2058 return MEMORY_MOVE_COST (MACRO_MODE (mode
), (enum reg_class
) rclass
, in
);
2062 /* Compute cost of moving data from a register of class FROM to one of
2066 default_register_move_cost (machine_mode mode ATTRIBUTE_UNUSED
,
2067 reg_class_t from ATTRIBUTE_UNUSED
,
2068 reg_class_t to ATTRIBUTE_UNUSED
)
2070 #ifndef REGISTER_MOVE_COST
2073 return REGISTER_MOVE_COST (MACRO_MODE (mode
),
2074 (enum reg_class
) from
, (enum reg_class
) to
);
2078 /* The default implementation of TARGET_SLOW_UNALIGNED_ACCESS. */
2081 default_slow_unaligned_access (machine_mode
, unsigned int)
2083 return STRICT_ALIGNMENT
;
2086 /* The default implementation of TARGET_ESTIMATED_POLY_VALUE. */
2089 default_estimated_poly_value (poly_int64 x
, poly_value_estimate_kind
)
2094 /* For hooks which use the MOVE_RATIO macro, this gives the legacy default
2095 behavior. SPEED_P is true if we are compiling for speed. */
2098 get_move_ratio (bool speed_p ATTRIBUTE_UNUSED
)
2100 unsigned int move_ratio
;
2102 move_ratio
= (unsigned int) MOVE_RATIO (speed_p
);
2104 #if defined (HAVE_cpymemqi) || defined (HAVE_cpymemhi) || defined (HAVE_cpymemsi) || defined (HAVE_cpymemdi) || defined (HAVE_cpymemti)
2106 #else /* No cpymem patterns, pick a default. */
2107 move_ratio
= ((speed_p
) ? 15 : 3);
2113 /* Return TRUE if the move_by_pieces/set_by_pieces infrastructure should be
2114 used; return FALSE if the cpymem/setmem optab should be expanded, or
2115 a call to memcpy emitted. */
2118 default_use_by_pieces_infrastructure_p (unsigned HOST_WIDE_INT size
,
2119 unsigned int alignment
,
2120 enum by_pieces_operation op
,
2123 unsigned int max_size
= 0;
2124 unsigned int ratio
= 0;
2128 case CLEAR_BY_PIECES
:
2129 max_size
= STORE_MAX_PIECES
;
2130 ratio
= CLEAR_RATIO (speed_p
);
2132 case MOVE_BY_PIECES
:
2133 max_size
= MOVE_MAX_PIECES
;
2134 ratio
= get_move_ratio (speed_p
);
2137 max_size
= STORE_MAX_PIECES
;
2138 ratio
= SET_RATIO (speed_p
);
2140 case STORE_BY_PIECES
:
2141 max_size
= STORE_MAX_PIECES
;
2142 ratio
= get_move_ratio (speed_p
);
2144 case COMPARE_BY_PIECES
:
2145 max_size
= COMPARE_MAX_PIECES
;
2146 /* Pick a likely default, just as in get_move_ratio. */
2147 ratio
= speed_p
? 15 : 3;
2151 return by_pieces_ninsns (size
, alignment
, max_size
+ 1, op
) < ratio
;
2154 /* This hook controls code generation for expanding a memcmp operation by
2155 pieces. Return 1 for the normal pattern of compare/jump after each pair
2156 of loads, or a higher number to reduce the number of branches. */
2159 default_compare_by_pieces_branch_ratio (machine_mode
)
2164 /* Write PATCH_AREA_SIZE NOPs into the asm outfile FILE around a function
2165 entry. If RECORD_P is true and the target supports named sections,
2166 the location of the NOPs will be recorded in a special object section
2167 called "__patchable_function_entries". This routine may be called
2168 twice per function to put NOPs before and after the function
2172 default_print_patchable_function_entry (FILE *file
,
2173 unsigned HOST_WIDE_INT patch_area_size
,
2176 const char *nop_templ
= 0;
2178 rtx_insn
*my_nop
= make_insn_raw (gen_nop ());
2180 /* We use the template alone, relying on the (currently sane) assumption
2181 that the NOP template does not have variable operands. */
2182 code_num
= recog_memoized (my_nop
);
2183 nop_templ
= get_insn_template (code_num
, my_nop
);
2185 if (record_p
&& targetm_common
.have_named_sections
)
2188 section
*previous_section
= in_section
;
2189 const char *asm_op
= integer_asm_op (POINTER_SIZE_UNITS
, false);
2191 gcc_assert (asm_op
!= NULL
);
2192 /* If SECTION_LINK_ORDER is supported, this internal label will
2193 be filled as the symbol for linked_to section. */
2194 ASM_GENERATE_INTERNAL_LABEL (buf
, "LPFE", current_function_funcdef_no
);
2196 unsigned int flags
= SECTION_WRITE
| SECTION_RELRO
;
2197 if (HAVE_GAS_SECTION_LINK_ORDER
)
2198 flags
|= SECTION_LINK_ORDER
;
2200 section
*sect
= get_section ("__patchable_function_entries",
2201 flags
, current_function_decl
);
2202 if (HAVE_COMDAT_GROUP
&& DECL_COMDAT_GROUP (current_function_decl
))
2203 switch_to_comdat_section (sect
, current_function_decl
);
2205 switch_to_section (sect
);
2206 assemble_align (POINTER_SIZE
);
2207 fputs (asm_op
, file
);
2208 assemble_name_raw (file
, buf
);
2211 switch_to_section (previous_section
);
2212 ASM_OUTPUT_LABEL (file
, buf
);
2216 for (i
= 0; i
< patch_area_size
; ++i
)
2217 output_asm_insn (nop_templ
, NULL
);
2221 default_profile_before_prologue (void)
2223 #ifdef PROFILE_BEFORE_PROLOGUE
2230 /* The default implementation of TARGET_PREFERRED_RELOAD_CLASS. */
2233 default_preferred_reload_class (rtx x ATTRIBUTE_UNUSED
,
2236 #ifdef PREFERRED_RELOAD_CLASS
2237 return (reg_class_t
) PREFERRED_RELOAD_CLASS (x
, (enum reg_class
) rclass
);
2243 /* The default implementation of TARGET_OUTPUT_PREFERRED_RELOAD_CLASS. */
2246 default_preferred_output_reload_class (rtx x ATTRIBUTE_UNUSED
,
2252 /* The default implementation of TARGET_PREFERRED_RENAME_CLASS. */
2254 default_preferred_rename_class (reg_class_t rclass ATTRIBUTE_UNUSED
)
2259 /* The default implementation of TARGET_CLASS_LIKELY_SPILLED_P. */
2262 default_class_likely_spilled_p (reg_class_t rclass
)
2264 return (reg_class_size
[(int) rclass
] == 1);
2267 /* The default implementation of TARGET_CLASS_MAX_NREGS. */
2270 default_class_max_nregs (reg_class_t rclass ATTRIBUTE_UNUSED
,
2271 machine_mode mode ATTRIBUTE_UNUSED
)
2273 #ifdef CLASS_MAX_NREGS
2274 return (unsigned char) CLASS_MAX_NREGS ((enum reg_class
) rclass
,
2277 /* Targets with variable-sized modes must provide their own definition
2279 unsigned int size
= GET_MODE_SIZE (mode
).to_constant ();
2280 return (size
+ UNITS_PER_WORD
- 1) / UNITS_PER_WORD
;
2284 /* Determine the debugging unwind mechanism for the target. */
2286 enum unwind_info_type
2287 default_debug_unwind_info (void)
2289 /* If the target wants to force the use of dwarf2 unwind info, let it. */
2290 /* ??? Change all users to the hook, then poison this. */
2291 #ifdef DWARF2_FRAME_INFO
2292 if (DWARF2_FRAME_INFO
)
2296 /* Otherwise, only turn it on if dwarf2 debugging is enabled. */
2297 #ifdef DWARF2_DEBUGGING_INFO
2298 if (dwarf_debuginfo_p ())
2305 /* Targets that set NUM_POLY_INT_COEFFS to something greater than 1
2306 must define this hook. */
2309 default_dwarf_poly_indeterminate_value (unsigned int, unsigned int *, int *)
2314 /* Determine the correct mode for a Dwarf frame register that represents
2318 default_dwarf_frame_reg_mode (int regno
)
2320 machine_mode save_mode
= reg_raw_mode
[regno
];
2322 if (targetm
.hard_regno_call_part_clobbered (eh_edge_abi
.id (),
2324 save_mode
= choose_hard_reg_mode (regno
, 1, &eh_edge_abi
);
2328 /* To be used by targets where reg_raw_mode doesn't return the right
2329 mode for registers used in apply_builtin_return and apply_builtin_arg. */
2332 default_get_reg_raw_mode (int regno
)
2334 /* Targets must override this hook if the underlying register is
2336 return as_a
<fixed_size_mode
> (reg_raw_mode
[regno
]);
2339 /* Return true if a leaf function should stay leaf even with profiling
2343 default_keep_leaf_when_profiled ()
2348 /* Return true if the state of option OPTION should be stored in PCH files
2349 and checked by default_pch_valid_p. Store the option's current state
2353 option_affects_pch_p (int option
, struct cl_option_state
*state
)
2355 if ((cl_options
[option
].flags
& CL_TARGET
) == 0)
2357 if ((cl_options
[option
].flags
& CL_PCH_IGNORE
) != 0)
2359 if (option_flag_var (option
, &global_options
) == &target_flags
)
2360 if (targetm
.check_pch_target_flags
)
2362 return get_option_state (&global_options
, option
, state
);
2365 /* Default version of get_pch_validity.
2366 By default, every flag difference is fatal; that will be mostly right for
2367 most targets, but completely right for very few. */
2370 default_get_pch_validity (size_t *sz
)
2372 struct cl_option_state state
;
2377 if (targetm
.check_pch_target_flags
)
2378 *sz
+= sizeof (target_flags
);
2379 for (i
= 0; i
< cl_options_count
; i
++)
2380 if (option_affects_pch_p (i
, &state
))
2383 result
= r
= XNEWVEC (char, *sz
);
2387 if (targetm
.check_pch_target_flags
)
2389 memcpy (r
, &target_flags
, sizeof (target_flags
));
2390 r
+= sizeof (target_flags
);
2393 for (i
= 0; i
< cl_options_count
; i
++)
2394 if (option_affects_pch_p (i
, &state
))
2396 memcpy (r
, state
.data
, state
.size
);
2403 /* Return a message which says that a PCH file was created with a different
2404 setting of OPTION. */
2407 pch_option_mismatch (const char *option
)
2409 return xasprintf (_("created and used with differing settings of '%s'"),
2413 /* Default version of pch_valid_p. */
2416 default_pch_valid_p (const void *data_p
, size_t len ATTRIBUTE_UNUSED
)
2418 struct cl_option_state state
;
2419 const char *data
= (const char *)data_p
;
2422 /* -fpic and -fpie also usually make a PCH invalid. */
2423 if (data
[0] != flag_pic
)
2424 return _("created and used with different settings of %<-fpic%>");
2425 if (data
[1] != flag_pie
)
2426 return _("created and used with different settings of %<-fpie%>");
2429 /* Check target_flags. */
2430 if (targetm
.check_pch_target_flags
)
2435 memcpy (&tf
, data
, sizeof (target_flags
));
2436 data
+= sizeof (target_flags
);
2437 r
= targetm
.check_pch_target_flags (tf
);
2442 for (i
= 0; i
< cl_options_count
; i
++)
2443 if (option_affects_pch_p (i
, &state
))
2445 if (memcmp (data
, state
.data
, state
.size
) != 0)
2446 return pch_option_mismatch (cl_options
[i
].opt_text
);
2453 /* Default version of cstore_mode. */
2456 default_cstore_mode (enum insn_code icode
)
2458 return as_a
<scalar_int_mode
> (insn_data
[(int) icode
].operand
[0].mode
);
2461 /* Default version of member_type_forces_blk. */
2464 default_member_type_forces_blk (const_tree
, machine_mode
)
2469 /* Default version of canonicalize_comparison. */
2472 default_canonicalize_comparison (int *, rtx
*, rtx
*, bool)
2476 /* Default implementation of TARGET_ATOMIC_ASSIGN_EXPAND_FENV. */
2479 default_atomic_assign_expand_fenv (tree
*, tree
*, tree
*)
2483 #ifndef PAD_VARARGS_DOWN
2484 #define PAD_VARARGS_DOWN BYTES_BIG_ENDIAN
2487 /* Build an indirect-ref expression over the given TREE, which represents a
2488 piece of a va_arg() expansion. */
2490 build_va_arg_indirect_ref (tree addr
)
2492 addr
= build_simple_mem_ref_loc (EXPR_LOCATION (addr
), addr
);
2496 /* The "standard" implementation of va_arg: read the value from the
2497 current (padded) address and increment by the (padded) size. */
2500 std_gimplify_va_arg_expr (tree valist
, tree type
, gimple_seq
*pre_p
,
2503 tree addr
, t
, type_size
, rounded_size
, valist_tmp
;
2504 unsigned HOST_WIDE_INT align
, boundary
;
2507 /* All of the alignment and movement below is for args-grow-up machines.
2508 As of 2004, there are only 3 ARGS_GROW_DOWNWARD targets, and they all
2509 implement their own specialized gimplify_va_arg_expr routines. */
2510 if (ARGS_GROW_DOWNWARD
)
2513 indirect
= pass_va_arg_by_reference (type
);
2515 type
= build_pointer_type (type
);
2517 if (targetm
.calls
.split_complex_arg
2518 && TREE_CODE (type
) == COMPLEX_TYPE
2519 && targetm
.calls
.split_complex_arg (type
))
2521 tree real_part
, imag_part
;
2523 real_part
= std_gimplify_va_arg_expr (valist
,
2524 TREE_TYPE (type
), pre_p
, NULL
);
2525 real_part
= get_initialized_tmp_var (real_part
, pre_p
);
2527 imag_part
= std_gimplify_va_arg_expr (unshare_expr (valist
),
2528 TREE_TYPE (type
), pre_p
, NULL
);
2529 imag_part
= get_initialized_tmp_var (imag_part
, pre_p
);
2531 return build2 (COMPLEX_EXPR
, type
, real_part
, imag_part
);
2534 align
= PARM_BOUNDARY
/ BITS_PER_UNIT
;
2535 boundary
= targetm
.calls
.function_arg_boundary (TYPE_MODE (type
), type
);
2537 /* When we align parameter on stack for caller, if the parameter
2538 alignment is beyond MAX_SUPPORTED_STACK_ALIGNMENT, it will be
2539 aligned at MAX_SUPPORTED_STACK_ALIGNMENT. We will match callee
2540 here with caller. */
2541 if (boundary
> MAX_SUPPORTED_STACK_ALIGNMENT
)
2542 boundary
= MAX_SUPPORTED_STACK_ALIGNMENT
;
2544 boundary
/= BITS_PER_UNIT
;
2546 /* Hoist the valist value into a temporary for the moment. */
2547 valist_tmp
= get_initialized_tmp_var (valist
, pre_p
);
2549 /* va_list pointer is aligned to PARM_BOUNDARY. If argument actually
2550 requires greater alignment, we must perform dynamic alignment. */
2551 if (boundary
> align
2552 && !TYPE_EMPTY_P (type
)
2553 && !integer_zerop (TYPE_SIZE (type
)))
2555 t
= build2 (MODIFY_EXPR
, TREE_TYPE (valist
), valist_tmp
,
2556 fold_build_pointer_plus_hwi (valist_tmp
, boundary
- 1));
2557 gimplify_and_add (t
, pre_p
);
2559 t
= build2 (MODIFY_EXPR
, TREE_TYPE (valist
), valist_tmp
,
2560 fold_build2 (BIT_AND_EXPR
, TREE_TYPE (valist
),
2562 build_int_cst (TREE_TYPE (valist
), -boundary
)));
2563 gimplify_and_add (t
, pre_p
);
2568 /* If the actual alignment is less than the alignment of the type,
2569 adjust the type accordingly so that we don't assume strict alignment
2570 when dereferencing the pointer. */
2571 boundary
*= BITS_PER_UNIT
;
2572 if (boundary
< TYPE_ALIGN (type
))
2574 type
= build_variant_type_copy (type
);
2575 SET_TYPE_ALIGN (type
, boundary
);
2578 /* Compute the rounded size of the type. */
2579 type_size
= arg_size_in_bytes (type
);
2580 rounded_size
= round_up (type_size
, align
);
2582 /* Reduce rounded_size so it's sharable with the postqueue. */
2583 gimplify_expr (&rounded_size
, pre_p
, post_p
, is_gimple_val
, fb_rvalue
);
2587 if (PAD_VARARGS_DOWN
&& !integer_zerop (rounded_size
))
2589 /* Small args are padded downward. */
2590 t
= fold_build2_loc (input_location
, GT_EXPR
, sizetype
,
2591 rounded_size
, size_int (align
));
2592 t
= fold_build3 (COND_EXPR
, sizetype
, t
, size_zero_node
,
2593 size_binop (MINUS_EXPR
, rounded_size
, type_size
));
2594 addr
= fold_build_pointer_plus (addr
, t
);
2597 /* Compute new value for AP. */
2598 t
= fold_build_pointer_plus (valist_tmp
, rounded_size
);
2599 t
= build2 (MODIFY_EXPR
, TREE_TYPE (valist
), valist
, t
);
2600 gimplify_and_add (t
, pre_p
);
2602 addr
= fold_convert (build_pointer_type (type
), addr
);
2605 addr
= build_va_arg_indirect_ref (addr
);
2607 return build_va_arg_indirect_ref (addr
);
2610 /* An implementation of TARGET_CAN_USE_DOLOOP_P for targets that do
2611 not support nested low-overhead loops. */
2614 can_use_doloop_if_innermost (const widest_int
&, const widest_int
&,
2615 unsigned int loop_depth
, bool)
2617 return loop_depth
== 1;
2620 /* Default implementation of TARGET_OPTAB_SUPPORTED_P. */
2623 default_optab_supported_p (int, machine_mode
, machine_mode
, optimization_type
)
2628 /* Default implementation of TARGET_MAX_NOCE_IFCVT_SEQ_COST. */
2631 default_max_noce_ifcvt_seq_cost (edge e
)
2633 bool predictable_p
= predictable_edge_p (e
);
2637 if (OPTION_SET_P (param_max_rtl_if_conversion_predictable_cost
))
2638 return param_max_rtl_if_conversion_predictable_cost
;
2642 if (OPTION_SET_P (param_max_rtl_if_conversion_unpredictable_cost
))
2643 return param_max_rtl_if_conversion_unpredictable_cost
;
2646 return BRANCH_COST (true, predictable_p
) * COSTS_N_INSNS (3);
2649 /* Default implementation of TARGET_MIN_ARITHMETIC_PRECISION. */
2652 default_min_arithmetic_precision (void)
2654 return WORD_REGISTER_OPERATIONS
? BITS_PER_WORD
: BITS_PER_UNIT
;
2657 /* Default implementation of TARGET_C_EXCESS_PRECISION. */
2659 enum flt_eval_method
2660 default_excess_precision (enum excess_precision_type ATTRIBUTE_UNUSED
)
2662 return FLT_EVAL_METHOD_PROMOTE_TO_FLOAT
;
2665 /* Return true if _BitInt(N) is supported and fill details about it into
2668 default_bitint_type_info (int, struct bitint_info
*)
2673 /* Default implementation for
2674 TARGET_STACK_CLASH_PROTECTION_ALLOCA_PROBE_RANGE. */
2676 default_stack_clash_protection_alloca_probe_range (void)
2681 /* The default implementation of TARGET_EARLY_REMAT_MODES. */
2684 default_select_early_remat_modes (sbitmap
)
2688 /* The default implementation of TARGET_PREFERRED_ELSE_VALUE. */
2691 default_preferred_else_value (unsigned, tree type
, unsigned, tree
*)
2693 return build_zero_cst (type
);
2696 /* Default implementation of TARGET_HAVE_SPECULATION_SAFE_VALUE. */
2698 default_have_speculation_safe_value (bool active ATTRIBUTE_UNUSED
)
2700 #ifdef HAVE_speculation_barrier
2701 return active
? HAVE_speculation_barrier
: true;
2706 /* Alternative implementation of TARGET_HAVE_SPECULATION_SAFE_VALUE
2707 that can be used on targets that never have speculative execution. */
2709 speculation_safe_value_not_needed (bool active
)
2714 /* Default implementation of the speculation-safe-load builtin. This
2715 implementation simply copies val to result and generates a
2716 speculation_barrier insn, if such a pattern is defined. */
2718 default_speculation_safe_value (machine_mode mode ATTRIBUTE_UNUSED
,
2719 rtx result
, rtx val
,
2720 rtx failval ATTRIBUTE_UNUSED
)
2722 emit_move_insn (result
, val
);
2724 #ifdef HAVE_speculation_barrier
2725 /* Assume the target knows what it is doing: if it defines a
2726 speculation barrier, but it is not enabled, then assume that one
2728 if (HAVE_speculation_barrier
)
2729 emit_insn (gen_speculation_barrier ());
2735 /* How many bits to shift in order to access the tag bits.
2736 The default is to store the tag in the top 8 bits of a 64 bit pointer, hence
2737 shifting 56 bits will leave just the tag. */
2738 #define HWASAN_SHIFT (GET_MODE_PRECISION (Pmode) - 8)
2739 #define HWASAN_SHIFT_RTX GEN_INT (HWASAN_SHIFT)
2742 default_memtag_can_tag_addresses ()
2748 default_memtag_tag_size ()
2754 default_memtag_granule_size ()
2759 /* The default implementation of TARGET_MEMTAG_INSERT_RANDOM_TAG. */
2761 default_memtag_insert_random_tag (rtx untagged
, rtx target
)
2763 gcc_assert (param_hwasan_instrument_stack
);
2764 if (param_hwasan_random_frame_tag
)
2766 rtx fn
= init_one_libfunc ("__hwasan_generate_tag");
2767 rtx new_tag
= emit_library_call_value (fn
, NULL_RTX
, LCT_NORMAL
, QImode
);
2768 return targetm
.memtag
.set_tag (untagged
, new_tag
, target
);
2772 /* NOTE: The kernel API does not have __hwasan_generate_tag exposed.
2773 In the future we may add the option emit random tags with inline
2774 instrumentation instead of function calls. This would be the same
2775 between the kernel and userland. */
2780 /* The default implementation of TARGET_MEMTAG_ADD_TAG. */
2782 default_memtag_add_tag (rtx base
, poly_int64 offset
, uint8_t tag_offset
)
2784 /* Need to look into what the most efficient code sequence is.
2785 This is a code sequence that would be emitted *many* times, so we
2786 want it as small as possible.
2788 There are two places where tag overflow is a question:
2789 - Tagging the shadow stack.
2790 (both tagging and untagging).
2791 - Tagging addressable pointers.
2793 We need to ensure both behaviors are the same (i.e. that the tag that
2794 ends up in a pointer after "overflowing" the tag bits with a tag addition
2795 is the same that ends up in the shadow space).
2797 The aim is that the behavior of tag addition should follow modulo
2798 wrapping in both instances.
2800 The libhwasan code doesn't have any path that increments a pointer's tag,
2801 which means it has no opinion on what happens when a tag increment
2802 overflows (and hence we can choose our own behavior). */
2804 offset
+= ((uint64_t)tag_offset
<< HWASAN_SHIFT
);
2805 return plus_constant (Pmode
, base
, offset
);
2808 /* The default implementation of TARGET_MEMTAG_SET_TAG. */
2810 default_memtag_set_tag (rtx untagged
, rtx tag
, rtx target
)
2812 gcc_assert (GET_MODE (untagged
) == Pmode
&& GET_MODE (tag
) == QImode
);
2813 tag
= expand_simple_binop (Pmode
, ASHIFT
, tag
, HWASAN_SHIFT_RTX
, NULL_RTX
,
2814 /* unsignedp = */1, OPTAB_WIDEN
);
2815 rtx ret
= expand_simple_binop (Pmode
, IOR
, untagged
, tag
, target
,
2816 /* unsignedp = */1, OPTAB_DIRECT
);
2821 /* The default implementation of TARGET_MEMTAG_EXTRACT_TAG. */
2823 default_memtag_extract_tag (rtx tagged_pointer
, rtx target
)
2825 rtx tag
= expand_simple_binop (Pmode
, LSHIFTRT
, tagged_pointer
,
2826 HWASAN_SHIFT_RTX
, target
,
2829 rtx ret
= gen_lowpart (QImode
, tag
);
2834 /* The default implementation of TARGET_MEMTAG_UNTAGGED_POINTER. */
2836 default_memtag_untagged_pointer (rtx tagged_pointer
, rtx target
)
2838 rtx tag_mask
= gen_int_mode ((HOST_WIDE_INT_1U
<< HWASAN_SHIFT
) - 1, Pmode
);
2839 rtx untagged_base
= expand_simple_binop (Pmode
, AND
, tagged_pointer
,
2840 tag_mask
, target
, true,
2842 gcc_assert (untagged_base
);
2843 return untagged_base
;
2846 #include "gt-targhooks.h"