1 /* Convert function calls to rtl insns, for GNU C compiler.
2 Copyright (C) 1989-2020 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/>. */
22 #include "coretypes.h"
31 #include "stringpool.h"
36 #include "diagnostic-core.h"
37 #include "fold-const.h"
38 #include "stor-layout.h"
40 #include "internal-fn.h"
46 #include "langhooks.h"
51 #include "tree-ssanames.h"
52 #include "tree-ssa-strlen.h"
54 #include "stringpool.h"
56 #include "hash-traits.h"
59 #include "gimple-fold.h"
61 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
62 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
64 /* Data structure and subroutines used within expand_call. */
68 /* Tree node for this argument. */
70 /* Mode for value; TYPE_MODE unless promoted. */
72 /* Current RTL value for argument, or 0 if it isn't precomputed. */
74 /* Initially-compute RTL value for argument; only for const functions. */
76 /* Register to pass this argument in, 0 if passed on stack, or an
77 PARALLEL if the arg is to be copied into multiple non-contiguous
80 /* Register to pass this argument in when generating tail call sequence.
81 This is not the same register as for normal calls on machines with
84 /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct
85 form for emit_group_move. */
87 /* If REG was promoted from the actual mode of the argument expression,
88 indicates whether the promotion is sign- or zero-extended. */
90 /* Number of bytes to put in registers. 0 means put the whole arg
91 in registers. Also 0 if not passed in registers. */
93 /* Nonzero if argument must be passed on stack.
94 Note that some arguments may be passed on the stack
95 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
96 pass_on_stack identifies arguments that *cannot* go in registers. */
98 /* Some fields packaged up for locate_and_pad_parm. */
99 struct locate_and_pad_arg_data locate
;
100 /* Location on the stack at which parameter should be stored. The store
101 has already been done if STACK == VALUE. */
103 /* Location on the stack of the start of this argument slot. This can
104 differ from STACK if this arg pads downward. This location is known
105 to be aligned to TARGET_FUNCTION_ARG_BOUNDARY. */
107 /* Place that this stack area has been saved, if needed. */
109 /* If an argument's alignment does not permit direct copying into registers,
110 copy in smaller-sized pieces into pseudos. These are stored in a
111 block pointed to by this field. The next field says how many
112 word-sized pseudos we made. */
117 /* A vector of one char per byte of stack space. A byte if nonzero if
118 the corresponding stack location has been used.
119 This vector is used to prevent a function call within an argument from
120 clobbering any stack already set up. */
121 static char *stack_usage_map
;
123 /* Size of STACK_USAGE_MAP. */
124 static unsigned int highest_outgoing_arg_in_use
;
126 /* Assume that any stack location at this byte index is used,
127 without checking the contents of stack_usage_map. */
128 static unsigned HOST_WIDE_INT stack_usage_watermark
= HOST_WIDE_INT_M1U
;
130 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
131 stack location's tail call argument has been already stored into the stack.
132 This bitmap is used to prevent sibling call optimization if function tries
133 to use parent's incoming argument slots when they have been already
134 overwritten with tail call arguments. */
135 static sbitmap stored_args_map
;
137 /* Assume that any virtual-incoming location at this byte index has been
138 stored, without checking the contents of stored_args_map. */
139 static unsigned HOST_WIDE_INT stored_args_watermark
;
141 /* stack_arg_under_construction is nonzero when an argument may be
142 initialized with a constructor call (including a C function that
143 returns a BLKmode struct) and expand_call must take special action
144 to make sure the object being constructed does not overlap the
145 argument list for the constructor call. */
146 static int stack_arg_under_construction
;
148 static void precompute_register_parameters (int, struct arg_data
*, int *);
149 static int store_one_arg (struct arg_data
*, rtx
, int, int, int);
150 static void store_unaligned_arguments_into_pseudos (struct arg_data
*, int);
151 static int finalize_must_preallocate (int, int, struct arg_data
*,
153 static void precompute_arguments (int, struct arg_data
*);
154 static void compute_argument_addresses (struct arg_data
*, rtx
, int);
155 static rtx
rtx_for_function_call (tree
, tree
);
156 static void load_register_parameters (struct arg_data
*, int, rtx
*, int,
158 static int special_function_p (const_tree
, int);
159 static int check_sibcall_argument_overlap_1 (rtx
);
160 static int check_sibcall_argument_overlap (rtx_insn
*, struct arg_data
*, int);
162 static tree
split_complex_types (tree
);
164 #ifdef REG_PARM_STACK_SPACE
165 static rtx
save_fixed_argument_area (int, rtx
, int *, int *);
166 static void restore_fixed_argument_area (rtx
, rtx
, int, int);
169 /* Return true if bytes [LOWER_BOUND, UPPER_BOUND) of the outgoing
170 stack region might already be in use. */
173 stack_region_maybe_used_p (poly_uint64 lower_bound
, poly_uint64 upper_bound
,
174 unsigned int reg_parm_stack_space
)
176 unsigned HOST_WIDE_INT const_lower
, const_upper
;
177 const_lower
= constant_lower_bound (lower_bound
);
178 if (!upper_bound
.is_constant (&const_upper
))
179 const_upper
= HOST_WIDE_INT_M1U
;
181 if (const_upper
> stack_usage_watermark
)
184 /* Don't worry about things in the fixed argument area;
185 it has already been saved. */
186 const_lower
= MAX (const_lower
, reg_parm_stack_space
);
187 const_upper
= MIN (const_upper
, highest_outgoing_arg_in_use
);
188 for (unsigned HOST_WIDE_INT i
= const_lower
; i
< const_upper
; ++i
)
189 if (stack_usage_map
[i
])
194 /* Record that bytes [LOWER_BOUND, UPPER_BOUND) of the outgoing
195 stack region are now in use. */
198 mark_stack_region_used (poly_uint64 lower_bound
, poly_uint64 upper_bound
)
200 unsigned HOST_WIDE_INT const_lower
, const_upper
;
201 const_lower
= constant_lower_bound (lower_bound
);
202 if (upper_bound
.is_constant (&const_upper
))
203 for (unsigned HOST_WIDE_INT i
= const_lower
; i
< const_upper
; ++i
)
204 stack_usage_map
[i
] = 1;
206 stack_usage_watermark
= MIN (stack_usage_watermark
, const_lower
);
209 /* Force FUNEXP into a form suitable for the address of a CALL,
210 and return that as an rtx. Also load the static chain register
211 if FNDECL is a nested function.
213 CALL_FUSAGE points to a variable holding the prospective
214 CALL_INSN_FUNCTION_USAGE information. */
217 prepare_call_address (tree fndecl_or_type
, rtx funexp
, rtx static_chain_value
,
218 rtx
*call_fusage
, int reg_parm_seen
, int flags
)
220 /* Make a valid memory address and copy constants through pseudo-regs,
221 but not for a constant address if -fno-function-cse. */
222 if (GET_CODE (funexp
) != SYMBOL_REF
)
224 /* If it's an indirect call by descriptor, generate code to perform
225 runtime identification of the pointer and load the descriptor. */
226 if ((flags
& ECF_BY_DESCRIPTOR
) && !flag_trampolines
)
228 const int bit_val
= targetm
.calls
.custom_function_descriptors
;
229 rtx call_lab
= gen_label_rtx ();
231 gcc_assert (fndecl_or_type
&& TYPE_P (fndecl_or_type
));
233 = build_decl (UNKNOWN_LOCATION
, FUNCTION_DECL
, NULL_TREE
,
235 DECL_STATIC_CHAIN (fndecl_or_type
) = 1;
236 rtx chain
= targetm
.calls
.static_chain (fndecl_or_type
, false);
238 if (GET_MODE (funexp
) != Pmode
)
239 funexp
= convert_memory_address (Pmode
, funexp
);
241 /* Avoid long live ranges around function calls. */
242 funexp
= copy_to_mode_reg (Pmode
, funexp
);
245 emit_insn (gen_rtx_CLOBBER (VOIDmode
, chain
));
247 /* Emit the runtime identification pattern. */
248 rtx mask
= gen_rtx_AND (Pmode
, funexp
, GEN_INT (bit_val
));
249 emit_cmp_and_jump_insns (mask
, const0_rtx
, EQ
, NULL_RTX
, Pmode
, 1,
252 /* Statically predict the branch to very likely taken. */
253 rtx_insn
*insn
= get_last_insn ();
255 predict_insn_def (insn
, PRED_BUILTIN_EXPECT
, TAKEN
);
257 /* Load the descriptor. */
258 rtx mem
= gen_rtx_MEM (ptr_mode
,
259 plus_constant (Pmode
, funexp
, - bit_val
));
260 MEM_NOTRAP_P (mem
) = 1;
261 mem
= convert_memory_address (Pmode
, mem
);
262 emit_move_insn (chain
, mem
);
264 mem
= gen_rtx_MEM (ptr_mode
,
265 plus_constant (Pmode
, funexp
,
266 POINTER_SIZE
/ BITS_PER_UNIT
268 MEM_NOTRAP_P (mem
) = 1;
269 mem
= convert_memory_address (Pmode
, mem
);
270 emit_move_insn (funexp
, mem
);
272 emit_label (call_lab
);
276 use_reg (call_fusage
, chain
);
277 STATIC_CHAIN_REG_P (chain
) = 1;
280 /* Make sure we're not going to be overwritten below. */
281 gcc_assert (!static_chain_value
);
284 /* If we are using registers for parameters, force the
285 function address into a register now. */
286 funexp
= ((reg_parm_seen
287 && targetm
.small_register_classes_for_mode_p (FUNCTION_MODE
))
288 ? force_not_mem (memory_address (FUNCTION_MODE
, funexp
))
289 : memory_address (FUNCTION_MODE
, funexp
));
293 /* funexp could be a SYMBOL_REF represents a function pointer which is
294 of ptr_mode. In this case, it should be converted into address mode
295 to be a valid address for memory rtx pattern. See PR 64971. */
296 if (GET_MODE (funexp
) != Pmode
)
297 funexp
= convert_memory_address (Pmode
, funexp
);
299 if (!(flags
& ECF_SIBCALL
))
301 if (!NO_FUNCTION_CSE
&& optimize
&& ! flag_no_function_cse
)
302 funexp
= force_reg (Pmode
, funexp
);
306 if (static_chain_value
!= 0
307 && (TREE_CODE (fndecl_or_type
) != FUNCTION_DECL
308 || DECL_STATIC_CHAIN (fndecl_or_type
)))
312 chain
= targetm
.calls
.static_chain (fndecl_or_type
, false);
313 static_chain_value
= convert_memory_address (Pmode
, static_chain_value
);
315 emit_move_insn (chain
, static_chain_value
);
318 use_reg (call_fusage
, chain
);
319 STATIC_CHAIN_REG_P (chain
) = 1;
326 /* Generate instructions to call function FUNEXP,
327 and optionally pop the results.
328 The CALL_INSN is the first insn generated.
330 FNDECL is the declaration node of the function. This is given to the
331 hook TARGET_RETURN_POPS_ARGS to determine whether this function pops
334 FUNTYPE is the data type of the function. This is given to the hook
335 TARGET_RETURN_POPS_ARGS to determine whether this function pops its
336 own args. We used to allow an identifier for library functions, but
337 that doesn't work when the return type is an aggregate type and the
338 calling convention says that the pointer to this aggregate is to be
339 popped by the callee.
341 STACK_SIZE is the number of bytes of arguments on the stack,
342 ROUNDED_STACK_SIZE is that number rounded up to
343 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
344 both to put into the call insn and to generate explicit popping
347 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
348 It is zero if this call doesn't want a structure value.
350 NEXT_ARG_REG is the rtx that results from executing
351 targetm.calls.function_arg (&args_so_far,
352 function_arg_info::end_marker ());
353 just after all the args have had their registers assigned.
354 This could be whatever you like, but normally it is the first
355 arg-register beyond those used for args in this call,
356 or 0 if all the arg-registers are used in this call.
357 It is passed on to `gen_call' so you can put this info in the call insn.
359 VALREG is a hard register in which a value is returned,
360 or 0 if the call does not return a value.
362 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
363 the args to this call were processed.
364 We restore `inhibit_defer_pop' to that value.
366 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
367 denote registers used by the called function. */
370 emit_call_1 (rtx funexp
, tree fntree ATTRIBUTE_UNUSED
, tree fndecl ATTRIBUTE_UNUSED
,
371 tree funtype ATTRIBUTE_UNUSED
,
372 poly_int64 stack_size ATTRIBUTE_UNUSED
,
373 poly_int64 rounded_stack_size
,
374 poly_int64 struct_value_size ATTRIBUTE_UNUSED
,
375 rtx next_arg_reg ATTRIBUTE_UNUSED
, rtx valreg
,
376 int old_inhibit_defer_pop
, rtx call_fusage
, int ecf_flags
,
377 cumulative_args_t args_so_far ATTRIBUTE_UNUSED
)
379 rtx rounded_stack_size_rtx
= gen_int_mode (rounded_stack_size
, Pmode
);
380 rtx call
, funmem
, pat
;
381 int already_popped
= 0;
382 poly_int64 n_popped
= 0;
384 /* Sibling call patterns never pop arguments (no sibcall(_value)_pop
385 patterns exist). Any popping that the callee does on return will
386 be from our caller's frame rather than ours. */
387 if (!(ecf_flags
& ECF_SIBCALL
))
389 n_popped
+= targetm
.calls
.return_pops_args (fndecl
, funtype
, stack_size
);
391 #ifdef CALL_POPS_ARGS
392 n_popped
+= CALL_POPS_ARGS (*get_cumulative_args (args_so_far
));
396 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
397 and we don't want to load it into a register as an optimization,
398 because prepare_call_address already did it if it should be done. */
399 if (GET_CODE (funexp
) != SYMBOL_REF
)
400 funexp
= memory_address (FUNCTION_MODE
, funexp
);
402 funmem
= gen_rtx_MEM (FUNCTION_MODE
, funexp
);
403 if (fndecl
&& TREE_CODE (fndecl
) == FUNCTION_DECL
)
407 /* Although a built-in FUNCTION_DECL and its non-__builtin
408 counterpart compare equal and get a shared mem_attrs, they
409 produce different dump output in compare-debug compilations,
410 if an entry gets garbage collected in one compilation, then
411 adds a different (but equivalent) entry, while the other
412 doesn't run the garbage collector at the same spot and then
413 shares the mem_attr with the equivalent entry. */
414 if (DECL_BUILT_IN_CLASS (t
) == BUILT_IN_NORMAL
)
416 tree t2
= builtin_decl_explicit (DECL_FUNCTION_CODE (t
));
421 set_mem_expr (funmem
, t
);
424 set_mem_expr (funmem
, build_simple_mem_ref (CALL_EXPR_FN (fntree
)));
426 if (ecf_flags
& ECF_SIBCALL
)
429 pat
= targetm
.gen_sibcall_value (valreg
, funmem
,
430 rounded_stack_size_rtx
,
431 next_arg_reg
, NULL_RTX
);
433 pat
= targetm
.gen_sibcall (funmem
, rounded_stack_size_rtx
,
435 gen_int_mode (struct_value_size
, Pmode
));
437 /* If the target has "call" or "call_value" insns, then prefer them
438 if no arguments are actually popped. If the target does not have
439 "call" or "call_value" insns, then we must use the popping versions
440 even if the call has no arguments to pop. */
441 else if (maybe_ne (n_popped
, 0)
443 ? targetm
.have_call_value ()
444 : targetm
.have_call ()))
446 rtx n_pop
= gen_int_mode (n_popped
, Pmode
);
448 /* If this subroutine pops its own args, record that in the call insn
449 if possible, for the sake of frame pointer elimination. */
452 pat
= targetm
.gen_call_value_pop (valreg
, funmem
,
453 rounded_stack_size_rtx
,
454 next_arg_reg
, n_pop
);
456 pat
= targetm
.gen_call_pop (funmem
, rounded_stack_size_rtx
,
457 next_arg_reg
, n_pop
);
464 pat
= targetm
.gen_call_value (valreg
, funmem
, rounded_stack_size_rtx
,
465 next_arg_reg
, NULL_RTX
);
467 pat
= targetm
.gen_call (funmem
, rounded_stack_size_rtx
, next_arg_reg
,
468 gen_int_mode (struct_value_size
, Pmode
));
472 /* Find the call we just emitted. */
473 rtx_call_insn
*call_insn
= last_call_insn ();
475 /* Some target create a fresh MEM instead of reusing the one provided
476 above. Set its MEM_EXPR. */
477 call
= get_call_rtx_from (call_insn
);
479 && MEM_EXPR (XEXP (call
, 0)) == NULL_TREE
480 && MEM_EXPR (funmem
) != NULL_TREE
)
481 set_mem_expr (XEXP (call
, 0), MEM_EXPR (funmem
));
483 /* Put the register usage information there. */
484 add_function_usage_to (call_insn
, call_fusage
);
486 /* If this is a const call, then set the insn's unchanging bit. */
487 if (ecf_flags
& ECF_CONST
)
488 RTL_CONST_CALL_P (call_insn
) = 1;
490 /* If this is a pure call, then set the insn's unchanging bit. */
491 if (ecf_flags
& ECF_PURE
)
492 RTL_PURE_CALL_P (call_insn
) = 1;
494 /* If this is a const call, then set the insn's unchanging bit. */
495 if (ecf_flags
& ECF_LOOPING_CONST_OR_PURE
)
496 RTL_LOOPING_CONST_OR_PURE_CALL_P (call_insn
) = 1;
498 /* Create a nothrow REG_EH_REGION note, if needed. */
499 make_reg_eh_region_note (call_insn
, ecf_flags
, 0);
501 if (ecf_flags
& ECF_NORETURN
)
502 add_reg_note (call_insn
, REG_NORETURN
, const0_rtx
);
504 if (ecf_flags
& ECF_RETURNS_TWICE
)
506 add_reg_note (call_insn
, REG_SETJMP
, const0_rtx
);
507 cfun
->calls_setjmp
= 1;
510 SIBLING_CALL_P (call_insn
) = ((ecf_flags
& ECF_SIBCALL
) != 0);
512 /* Restore this now, so that we do defer pops for this call's args
513 if the context of the call as a whole permits. */
514 inhibit_defer_pop
= old_inhibit_defer_pop
;
516 if (maybe_ne (n_popped
, 0))
519 CALL_INSN_FUNCTION_USAGE (call_insn
)
520 = gen_rtx_EXPR_LIST (VOIDmode
,
521 gen_rtx_CLOBBER (VOIDmode
, stack_pointer_rtx
),
522 CALL_INSN_FUNCTION_USAGE (call_insn
));
523 rounded_stack_size
-= n_popped
;
524 rounded_stack_size_rtx
= gen_int_mode (rounded_stack_size
, Pmode
);
525 stack_pointer_delta
-= n_popped
;
527 add_args_size_note (call_insn
, stack_pointer_delta
);
529 /* If popup is needed, stack realign must use DRAP */
530 if (SUPPORTS_STACK_ALIGNMENT
)
531 crtl
->need_drap
= true;
533 /* For noreturn calls when not accumulating outgoing args force
534 REG_ARGS_SIZE note to prevent crossjumping of calls with different
536 else if (!ACCUMULATE_OUTGOING_ARGS
&& (ecf_flags
& ECF_NORETURN
) != 0)
537 add_args_size_note (call_insn
, stack_pointer_delta
);
539 if (!ACCUMULATE_OUTGOING_ARGS
)
541 /* If returning from the subroutine does not automatically pop the args,
542 we need an instruction to pop them sooner or later.
543 Perhaps do it now; perhaps just record how much space to pop later.
545 If returning from the subroutine does pop the args, indicate that the
546 stack pointer will be changed. */
548 if (maybe_ne (rounded_stack_size
, 0))
550 if (ecf_flags
& ECF_NORETURN
)
551 /* Just pretend we did the pop. */
552 stack_pointer_delta
-= rounded_stack_size
;
553 else if (flag_defer_pop
&& inhibit_defer_pop
== 0
554 && ! (ecf_flags
& (ECF_CONST
| ECF_PURE
)))
555 pending_stack_adjust
+= rounded_stack_size
;
557 adjust_stack (rounded_stack_size_rtx
);
560 /* When we accumulate outgoing args, we must avoid any stack manipulations.
561 Restore the stack pointer to its original value now. Usually
562 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
563 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
564 popping variants of functions exist as well.
566 ??? We may optimize similar to defer_pop above, but it is
567 probably not worthwhile.
569 ??? It will be worthwhile to enable combine_stack_adjustments even for
571 else if (maybe_ne (n_popped
, 0))
572 anti_adjust_stack (gen_int_mode (n_popped
, Pmode
));
575 /* Determine if the function identified by FNDECL is one with
576 special properties we wish to know about. Modify FLAGS accordingly.
578 For example, if the function might return more than one time (setjmp), then
579 set ECF_RETURNS_TWICE.
581 Set ECF_MAY_BE_ALLOCA for any memory allocation function that might allocate
582 space from the stack such as alloca. */
585 special_function_p (const_tree fndecl
, int flags
)
587 tree name_decl
= DECL_NAME (fndecl
);
589 if (maybe_special_function_p (fndecl
)
590 && IDENTIFIER_LENGTH (name_decl
) <= 11)
592 const char *name
= IDENTIFIER_POINTER (name_decl
);
593 const char *tname
= name
;
595 /* We assume that alloca will always be called by name. It
596 makes no sense to pass it as a pointer-to-function to
597 anything that does not understand its behavior. */
598 if (IDENTIFIER_LENGTH (name_decl
) == 6
600 && ! strcmp (name
, "alloca"))
601 flags
|= ECF_MAY_BE_ALLOCA
;
603 /* Disregard prefix _ or __. */
612 /* ECF_RETURNS_TWICE is safe even for -ffreestanding. */
613 if (! strcmp (tname
, "setjmp")
614 || ! strcmp (tname
, "sigsetjmp")
615 || ! strcmp (name
, "savectx")
616 || ! strcmp (name
, "vfork")
617 || ! strcmp (name
, "getcontext"))
618 flags
|= ECF_RETURNS_TWICE
;
621 if (DECL_BUILT_IN_CLASS (fndecl
) == BUILT_IN_NORMAL
622 && ALLOCA_FUNCTION_CODE_P (DECL_FUNCTION_CODE (fndecl
)))
623 flags
|= ECF_MAY_BE_ALLOCA
;
628 /* Similar to special_function_p; return a set of ERF_ flags for the
631 decl_return_flags (tree fndecl
)
634 tree type
= TREE_TYPE (fndecl
);
638 attr
= lookup_attribute ("fn spec", TYPE_ATTRIBUTES (type
));
642 attr
= TREE_VALUE (TREE_VALUE (attr
));
643 if (!attr
|| TREE_STRING_LENGTH (attr
) < 1)
646 switch (TREE_STRING_POINTER (attr
)[0])
652 return ERF_RETURNS_ARG
| (TREE_STRING_POINTER (attr
)[0] - '1');
663 /* Return nonzero when FNDECL represents a call to setjmp. */
666 setjmp_call_p (const_tree fndecl
)
668 if (DECL_IS_RETURNS_TWICE (fndecl
))
669 return ECF_RETURNS_TWICE
;
670 return special_function_p (fndecl
, 0) & ECF_RETURNS_TWICE
;
674 /* Return true if STMT may be an alloca call. */
677 gimple_maybe_alloca_call_p (const gimple
*stmt
)
681 if (!is_gimple_call (stmt
))
684 fndecl
= gimple_call_fndecl (stmt
);
685 if (fndecl
&& (special_function_p (fndecl
, 0) & ECF_MAY_BE_ALLOCA
))
691 /* Return true if STMT is a builtin alloca call. */
694 gimple_alloca_call_p (const gimple
*stmt
)
698 if (!is_gimple_call (stmt
))
701 fndecl
= gimple_call_fndecl (stmt
);
702 if (fndecl
&& fndecl_built_in_p (fndecl
, BUILT_IN_NORMAL
))
703 switch (DECL_FUNCTION_CODE (fndecl
))
705 CASE_BUILT_IN_ALLOCA
:
706 return gimple_call_num_args (stmt
) > 0;
714 /* Return true when exp contains a builtin alloca call. */
717 alloca_call_p (const_tree exp
)
720 if (TREE_CODE (exp
) == CALL_EXPR
721 && (fndecl
= get_callee_fndecl (exp
))
722 && DECL_BUILT_IN_CLASS (fndecl
) == BUILT_IN_NORMAL
)
723 switch (DECL_FUNCTION_CODE (fndecl
))
725 CASE_BUILT_IN_ALLOCA
:
734 /* Return TRUE if FNDECL is either a TM builtin or a TM cloned
735 function. Return FALSE otherwise. */
738 is_tm_builtin (const_tree fndecl
)
743 if (decl_is_tm_clone (fndecl
))
746 if (DECL_BUILT_IN_CLASS (fndecl
) == BUILT_IN_NORMAL
)
748 switch (DECL_FUNCTION_CODE (fndecl
))
750 case BUILT_IN_TM_COMMIT
:
751 case BUILT_IN_TM_COMMIT_EH
:
752 case BUILT_IN_TM_ABORT
:
753 case BUILT_IN_TM_IRREVOCABLE
:
754 case BUILT_IN_TM_GETTMCLONE_IRR
:
755 case BUILT_IN_TM_MEMCPY
:
756 case BUILT_IN_TM_MEMMOVE
:
757 case BUILT_IN_TM_MEMSET
:
758 CASE_BUILT_IN_TM_STORE (1):
759 CASE_BUILT_IN_TM_STORE (2):
760 CASE_BUILT_IN_TM_STORE (4):
761 CASE_BUILT_IN_TM_STORE (8):
762 CASE_BUILT_IN_TM_STORE (FLOAT
):
763 CASE_BUILT_IN_TM_STORE (DOUBLE
):
764 CASE_BUILT_IN_TM_STORE (LDOUBLE
):
765 CASE_BUILT_IN_TM_STORE (M64
):
766 CASE_BUILT_IN_TM_STORE (M128
):
767 CASE_BUILT_IN_TM_STORE (M256
):
768 CASE_BUILT_IN_TM_LOAD (1):
769 CASE_BUILT_IN_TM_LOAD (2):
770 CASE_BUILT_IN_TM_LOAD (4):
771 CASE_BUILT_IN_TM_LOAD (8):
772 CASE_BUILT_IN_TM_LOAD (FLOAT
):
773 CASE_BUILT_IN_TM_LOAD (DOUBLE
):
774 CASE_BUILT_IN_TM_LOAD (LDOUBLE
):
775 CASE_BUILT_IN_TM_LOAD (M64
):
776 CASE_BUILT_IN_TM_LOAD (M128
):
777 CASE_BUILT_IN_TM_LOAD (M256
):
778 case BUILT_IN_TM_LOG
:
779 case BUILT_IN_TM_LOG_1
:
780 case BUILT_IN_TM_LOG_2
:
781 case BUILT_IN_TM_LOG_4
:
782 case BUILT_IN_TM_LOG_8
:
783 case BUILT_IN_TM_LOG_FLOAT
:
784 case BUILT_IN_TM_LOG_DOUBLE
:
785 case BUILT_IN_TM_LOG_LDOUBLE
:
786 case BUILT_IN_TM_LOG_M64
:
787 case BUILT_IN_TM_LOG_M128
:
788 case BUILT_IN_TM_LOG_M256
:
797 /* Detect flags (function attributes) from the function decl or type node. */
800 flags_from_decl_or_type (const_tree exp
)
806 /* The function exp may have the `malloc' attribute. */
807 if (DECL_IS_MALLOC (exp
))
810 /* The function exp may have the `returns_twice' attribute. */
811 if (DECL_IS_RETURNS_TWICE (exp
))
812 flags
|= ECF_RETURNS_TWICE
;
814 /* Process the pure and const attributes. */
815 if (TREE_READONLY (exp
))
817 if (DECL_PURE_P (exp
))
819 if (DECL_LOOPING_CONST_OR_PURE_P (exp
))
820 flags
|= ECF_LOOPING_CONST_OR_PURE
;
822 if (DECL_IS_NOVOPS (exp
))
824 if (lookup_attribute ("leaf", DECL_ATTRIBUTES (exp
)))
826 if (lookup_attribute ("cold", DECL_ATTRIBUTES (exp
)))
829 if (TREE_NOTHROW (exp
))
830 flags
|= ECF_NOTHROW
;
834 if (is_tm_builtin (exp
))
835 flags
|= ECF_TM_BUILTIN
;
836 else if ((flags
& (ECF_CONST
|ECF_NOVOPS
)) != 0
837 || lookup_attribute ("transaction_pure",
838 TYPE_ATTRIBUTES (TREE_TYPE (exp
))))
839 flags
|= ECF_TM_PURE
;
842 flags
= special_function_p (exp
, flags
);
844 else if (TYPE_P (exp
))
846 if (TYPE_READONLY (exp
))
850 && ((flags
& ECF_CONST
) != 0
851 || lookup_attribute ("transaction_pure", TYPE_ATTRIBUTES (exp
))))
852 flags
|= ECF_TM_PURE
;
857 if (TREE_THIS_VOLATILE (exp
))
859 flags
|= ECF_NORETURN
;
860 if (flags
& (ECF_CONST
|ECF_PURE
))
861 flags
|= ECF_LOOPING_CONST_OR_PURE
;
867 /* Detect flags from a CALL_EXPR. */
870 call_expr_flags (const_tree t
)
873 tree decl
= get_callee_fndecl (t
);
876 flags
= flags_from_decl_or_type (decl
);
877 else if (CALL_EXPR_FN (t
) == NULL_TREE
)
878 flags
= internal_fn_flags (CALL_EXPR_IFN (t
));
881 tree type
= TREE_TYPE (CALL_EXPR_FN (t
));
882 if (type
&& TREE_CODE (type
) == POINTER_TYPE
)
883 flags
= flags_from_decl_or_type (TREE_TYPE (type
));
886 if (CALL_EXPR_BY_DESCRIPTOR (t
))
887 flags
|= ECF_BY_DESCRIPTOR
;
893 /* Return true if ARG should be passed by invisible reference. */
896 pass_by_reference (CUMULATIVE_ARGS
*ca
, function_arg_info arg
)
898 if (tree type
= arg
.type
)
900 /* If this type contains non-trivial constructors, then it is
901 forbidden for the middle-end to create any new copies. */
902 if (TREE_ADDRESSABLE (type
))
905 /* GCC post 3.4 passes *all* variable sized types by reference. */
906 if (!TYPE_SIZE (type
) || !poly_int_tree_p (TYPE_SIZE (type
)))
909 /* If a record type should be passed the same as its first (and only)
910 member, use the type and mode of that member. */
911 if (TREE_CODE (type
) == RECORD_TYPE
&& TYPE_TRANSPARENT_AGGR (type
))
913 arg
.type
= TREE_TYPE (first_field (type
));
914 arg
.mode
= TYPE_MODE (arg
.type
);
918 return targetm
.calls
.pass_by_reference (pack_cumulative_args (ca
), arg
);
921 /* Return true if TYPE should be passed by reference when passed to
922 the "..." arguments of a function. */
925 pass_va_arg_by_reference (tree type
)
927 return pass_by_reference (NULL
, function_arg_info (type
, /*named=*/false));
930 /* Decide whether ARG, which occurs in the state described by CA,
931 should be passed by reference. Return true if so and update
935 apply_pass_by_reference_rules (CUMULATIVE_ARGS
*ca
, function_arg_info
&arg
)
937 if (pass_by_reference (ca
, arg
))
939 arg
.type
= build_pointer_type (arg
.type
);
940 arg
.mode
= TYPE_MODE (arg
.type
);
941 arg
.pass_by_reference
= true;
947 /* Return true if ARG, which is passed by reference, should be callee
948 copied instead of caller copied. */
951 reference_callee_copied (CUMULATIVE_ARGS
*ca
, const function_arg_info
&arg
)
953 if (arg
.type
&& TREE_ADDRESSABLE (arg
.type
))
955 return targetm
.calls
.callee_copies (pack_cumulative_args (ca
), arg
);
959 /* Precompute all register parameters as described by ARGS, storing values
960 into fields within the ARGS array.
962 NUM_ACTUALS indicates the total number elements in the ARGS array.
964 Set REG_PARM_SEEN if we encounter a register parameter. */
967 precompute_register_parameters (int num_actuals
, struct arg_data
*args
,
974 for (i
= 0; i
< num_actuals
; i
++)
975 if (args
[i
].reg
!= 0 && ! args
[i
].pass_on_stack
)
979 if (args
[i
].value
== 0)
982 args
[i
].value
= expand_normal (args
[i
].tree_value
);
983 preserve_temp_slots (args
[i
].value
);
987 /* If we are to promote the function arg to a wider mode,
990 if (args
[i
].mode
!= TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)))
992 = convert_modes (args
[i
].mode
,
993 TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)),
994 args
[i
].value
, args
[i
].unsignedp
);
996 /* If the value is a non-legitimate constant, force it into a
997 pseudo now. TLS symbols sometimes need a call to resolve. */
998 if (CONSTANT_P (args
[i
].value
)
999 && !targetm
.legitimate_constant_p (args
[i
].mode
, args
[i
].value
))
1000 args
[i
].value
= force_reg (args
[i
].mode
, args
[i
].value
);
1002 /* If we're going to have to load the value by parts, pull the
1003 parts into pseudos. The part extraction process can involve
1004 non-trivial computation. */
1005 if (GET_CODE (args
[i
].reg
) == PARALLEL
)
1007 tree type
= TREE_TYPE (args
[i
].tree_value
);
1008 args
[i
].parallel_value
1009 = emit_group_load_into_temps (args
[i
].reg
, args
[i
].value
,
1010 type
, int_size_in_bytes (type
));
1013 /* If the value is expensive, and we are inside an appropriately
1014 short loop, put the value into a pseudo and then put the pseudo
1017 For small register classes, also do this if this call uses
1018 register parameters. This is to avoid reload conflicts while
1019 loading the parameters registers. */
1021 else if ((! (REG_P (args
[i
].value
)
1022 || (GET_CODE (args
[i
].value
) == SUBREG
1023 && REG_P (SUBREG_REG (args
[i
].value
)))))
1024 && args
[i
].mode
!= BLKmode
1025 && (set_src_cost (args
[i
].value
, args
[i
].mode
,
1026 optimize_insn_for_speed_p ())
1027 > COSTS_N_INSNS (1))
1029 && targetm
.small_register_classes_for_mode_p (args
[i
].mode
))
1031 args
[i
].value
= copy_to_mode_reg (args
[i
].mode
, args
[i
].value
);
1035 #ifdef REG_PARM_STACK_SPACE
1037 /* The argument list is the property of the called routine and it
1038 may clobber it. If the fixed area has been used for previous
1039 parameters, we must save and restore it. */
1042 save_fixed_argument_area (int reg_parm_stack_space
, rtx argblock
, int *low_to_save
, int *high_to_save
)
1047 /* Compute the boundary of the area that needs to be saved, if any. */
1048 high
= reg_parm_stack_space
;
1049 if (ARGS_GROW_DOWNWARD
)
1052 if (high
> highest_outgoing_arg_in_use
)
1053 high
= highest_outgoing_arg_in_use
;
1055 for (low
= 0; low
< high
; low
++)
1056 if (stack_usage_map
[low
] != 0 || low
>= stack_usage_watermark
)
1059 machine_mode save_mode
;
1065 while (stack_usage_map
[--high
] == 0)
1069 *high_to_save
= high
;
1071 num_to_save
= high
- low
+ 1;
1073 /* If we don't have the required alignment, must do this
1075 scalar_int_mode imode
;
1076 if (int_mode_for_size (num_to_save
* BITS_PER_UNIT
, 1).exists (&imode
)
1077 && (low
& (MIN (GET_MODE_SIZE (imode
),
1078 BIGGEST_ALIGNMENT
/ UNITS_PER_WORD
) - 1)) == 0)
1081 save_mode
= BLKmode
;
1083 if (ARGS_GROW_DOWNWARD
)
1088 addr
= plus_constant (Pmode
, argblock
, delta
);
1089 stack_area
= gen_rtx_MEM (save_mode
, memory_address (save_mode
, addr
));
1091 set_mem_align (stack_area
, PARM_BOUNDARY
);
1092 if (save_mode
== BLKmode
)
1094 save_area
= assign_stack_temp (BLKmode
, num_to_save
);
1095 emit_block_move (validize_mem (save_area
), stack_area
,
1096 GEN_INT (num_to_save
), BLOCK_OP_CALL_PARM
);
1100 save_area
= gen_reg_rtx (save_mode
);
1101 emit_move_insn (save_area
, stack_area
);
1111 restore_fixed_argument_area (rtx save_area
, rtx argblock
, int high_to_save
, int low_to_save
)
1113 machine_mode save_mode
= GET_MODE (save_area
);
1115 rtx addr
, stack_area
;
1117 if (ARGS_GROW_DOWNWARD
)
1118 delta
= -high_to_save
;
1120 delta
= low_to_save
;
1122 addr
= plus_constant (Pmode
, argblock
, delta
);
1123 stack_area
= gen_rtx_MEM (save_mode
, memory_address (save_mode
, addr
));
1124 set_mem_align (stack_area
, PARM_BOUNDARY
);
1126 if (save_mode
!= BLKmode
)
1127 emit_move_insn (stack_area
, save_area
);
1129 emit_block_move (stack_area
, validize_mem (save_area
),
1130 GEN_INT (high_to_save
- low_to_save
+ 1),
1131 BLOCK_OP_CALL_PARM
);
1133 #endif /* REG_PARM_STACK_SPACE */
1135 /* If any elements in ARGS refer to parameters that are to be passed in
1136 registers, but not in memory, and whose alignment does not permit a
1137 direct copy into registers. Copy the values into a group of pseudos
1138 which we will later copy into the appropriate hard registers.
1140 Pseudos for each unaligned argument will be stored into the array
1141 args[argnum].aligned_regs. The caller is responsible for deallocating
1142 the aligned_regs array if it is nonzero. */
1145 store_unaligned_arguments_into_pseudos (struct arg_data
*args
, int num_actuals
)
1149 for (i
= 0; i
< num_actuals
; i
++)
1150 if (args
[i
].reg
!= 0 && ! args
[i
].pass_on_stack
1151 && GET_CODE (args
[i
].reg
) != PARALLEL
1152 && args
[i
].mode
== BLKmode
1153 && MEM_P (args
[i
].value
)
1154 && (MEM_ALIGN (args
[i
].value
)
1155 < (unsigned int) MIN (BIGGEST_ALIGNMENT
, BITS_PER_WORD
)))
1157 int bytes
= int_size_in_bytes (TREE_TYPE (args
[i
].tree_value
));
1158 int endian_correction
= 0;
1160 if (args
[i
].partial
)
1162 gcc_assert (args
[i
].partial
% UNITS_PER_WORD
== 0);
1163 args
[i
].n_aligned_regs
= args
[i
].partial
/ UNITS_PER_WORD
;
1167 args
[i
].n_aligned_regs
1168 = (bytes
+ UNITS_PER_WORD
- 1) / UNITS_PER_WORD
;
1171 args
[i
].aligned_regs
= XNEWVEC (rtx
, args
[i
].n_aligned_regs
);
1173 /* Structures smaller than a word are normally aligned to the
1174 least significant byte. On a BYTES_BIG_ENDIAN machine,
1175 this means we must skip the empty high order bytes when
1176 calculating the bit offset. */
1177 if (bytes
< UNITS_PER_WORD
1178 #ifdef BLOCK_REG_PADDING
1179 && (BLOCK_REG_PADDING (args
[i
].mode
,
1180 TREE_TYPE (args
[i
].tree_value
), 1)
1186 endian_correction
= BITS_PER_WORD
- bytes
* BITS_PER_UNIT
;
1188 for (j
= 0; j
< args
[i
].n_aligned_regs
; j
++)
1190 rtx reg
= gen_reg_rtx (word_mode
);
1191 rtx word
= operand_subword_force (args
[i
].value
, j
, BLKmode
);
1192 int bitsize
= MIN (bytes
* BITS_PER_UNIT
, BITS_PER_WORD
);
1194 args
[i
].aligned_regs
[j
] = reg
;
1195 word
= extract_bit_field (word
, bitsize
, 0, 1, NULL_RTX
,
1196 word_mode
, word_mode
, false, NULL
);
1198 /* There is no need to restrict this code to loading items
1199 in TYPE_ALIGN sized hunks. The bitfield instructions can
1200 load up entire word sized registers efficiently.
1202 ??? This may not be needed anymore.
1203 We use to emit a clobber here but that doesn't let later
1204 passes optimize the instructions we emit. By storing 0 into
1205 the register later passes know the first AND to zero out the
1206 bitfield being set in the register is unnecessary. The store
1207 of 0 will be deleted as will at least the first AND. */
1209 emit_move_insn (reg
, const0_rtx
);
1211 bytes
-= bitsize
/ BITS_PER_UNIT
;
1212 store_bit_field (reg
, bitsize
, endian_correction
, 0, 0,
1213 word_mode
, word
, false);
1218 /* The limit set by -Walloc-larger-than=. */
1219 static GTY(()) tree alloc_object_size_limit
;
1221 /* Initialize ALLOC_OBJECT_SIZE_LIMIT based on the -Walloc-size-larger-than=
1222 setting if the option is specified, or to the maximum object size if it
1223 is not. Return the initialized value. */
1226 alloc_max_size (void)
1228 if (alloc_object_size_limit
)
1229 return alloc_object_size_limit
;
1231 HOST_WIDE_INT limit
= warn_alloc_size_limit
;
1232 if (limit
== HOST_WIDE_INT_MAX
)
1233 limit
= tree_to_shwi (TYPE_MAX_VALUE (ptrdiff_type_node
));
1235 alloc_object_size_limit
= build_int_cst (size_type_node
, limit
);
1237 return alloc_object_size_limit
;
1240 /* Return true when EXP's range can be determined and set RANGE[] to it
1241 after adjusting it if necessary to make EXP a represents a valid size
1242 of object, or a valid size argument to an allocation function declared
1243 with attribute alloc_size (whose argument may be signed), or to a string
1244 manipulation function like memset. When ALLOW_ZERO is true, allow
1245 returning a range of [0, 0] for a size in an anti-range [1, N] where
1246 N > PTRDIFF_MAX. A zero range is a (nearly) invalid argument to
1247 allocation functions like malloc but it is a valid argument to
1248 functions like memset. */
1251 get_size_range (tree exp
, tree range
[2], bool allow_zero
/* = false */)
1256 if (tree_fits_uhwi_p (exp
))
1258 /* EXP is a constant. */
1259 range
[0] = range
[1] = exp
;
1263 tree exptype
= TREE_TYPE (exp
);
1264 bool integral
= INTEGRAL_TYPE_P (exptype
);
1267 enum value_range_kind range_type
;
1270 range_type
= determine_value_range (exp
, &min
, &max
);
1272 range_type
= VR_VARYING
;
1274 if (range_type
== VR_VARYING
)
1278 /* Use the full range of the type of the expression when
1279 no value range information is available. */
1280 range
[0] = TYPE_MIN_VALUE (exptype
);
1281 range
[1] = TYPE_MAX_VALUE (exptype
);
1285 range
[0] = NULL_TREE
;
1286 range
[1] = NULL_TREE
;
1290 unsigned expprec
= TYPE_PRECISION (exptype
);
1292 bool signed_p
= !TYPE_UNSIGNED (exptype
);
1294 if (range_type
== VR_ANTI_RANGE
)
1298 if (wi::les_p (max
, 0))
1300 /* EXP is not in a strictly negative range. That means
1301 it must be in some (not necessarily strictly) positive
1302 range which includes zero. Since in signed to unsigned
1303 conversions negative values end up converted to large
1304 positive values, and otherwise they are not valid sizes,
1305 the resulting range is in both cases [0, TYPE_MAX]. */
1306 min
= wi::zero (expprec
);
1307 max
= wi::to_wide (TYPE_MAX_VALUE (exptype
));
1309 else if (wi::les_p (min
- 1, 0))
1311 /* EXP is not in a negative-positive range. That means EXP
1312 is either negative, or greater than max. Since negative
1313 sizes are invalid make the range [MAX + 1, TYPE_MAX]. */
1315 max
= wi::to_wide (TYPE_MAX_VALUE (exptype
));
1320 min
= wi::zero (expprec
);
1323 else if (wi::eq_p (0, min
- 1))
1325 /* EXP is unsigned and not in the range [1, MAX]. That means
1326 it's either zero or greater than MAX. Even though 0 would
1327 normally be detected by -Walloc-zero, unless ALLOW_ZERO
1328 is true, set the range to [MAX, TYPE_MAX] so that when MAX
1329 is greater than the limit the whole range is diagnosed. */
1331 min
= max
= wi::zero (expprec
);
1335 max
= wi::to_wide (TYPE_MAX_VALUE (exptype
));
1341 min
= wi::zero (expprec
);
1345 range
[0] = wide_int_to_tree (exptype
, min
);
1346 range
[1] = wide_int_to_tree (exptype
, max
);
1351 /* Diagnose a call EXP to function FN decorated with attribute alloc_size
1352 whose argument numbers given by IDX with values given by ARGS exceed
1353 the maximum object size or cause an unsigned oveflow (wrapping) when
1354 multiplied. FN is null when EXP is a call via a function pointer.
1355 When ARGS[0] is null the function does nothing. ARGS[1] may be null
1356 for functions like malloc, and non-null for those like calloc that
1357 are decorated with a two-argument attribute alloc_size. */
1360 maybe_warn_alloc_args_overflow (tree fn
, tree exp
, tree args
[2], int idx
[2])
1362 /* The range each of the (up to) two arguments is known to be in. */
1363 tree argrange
[2][2] = { { NULL_TREE
, NULL_TREE
}, { NULL_TREE
, NULL_TREE
} };
1365 /* Maximum object size set by -Walloc-size-larger-than= or SIZE_MAX / 2. */
1366 tree maxobjsize
= alloc_max_size ();
1368 location_t loc
= EXPR_LOCATION (exp
);
1370 tree fntype
= fn
? TREE_TYPE (fn
) : TREE_TYPE (TREE_TYPE (exp
));
1371 bool warned
= false;
1373 /* Validate each argument individually. */
1374 for (unsigned i
= 0; i
!= 2 && args
[i
]; ++i
)
1376 if (TREE_CODE (args
[i
]) == INTEGER_CST
)
1378 argrange
[i
][0] = args
[i
];
1379 argrange
[i
][1] = args
[i
];
1381 if (tree_int_cst_lt (args
[i
], integer_zero_node
))
1383 warned
= warning_at (loc
, OPT_Walloc_size_larger_than_
,
1384 "%Kargument %i value %qE is negative",
1385 exp
, idx
[i
] + 1, args
[i
]);
1387 else if (integer_zerop (args
[i
]))
1389 /* Avoid issuing -Walloc-zero for allocation functions other
1390 than __builtin_alloca that are declared with attribute
1391 returns_nonnull because there's no portability risk. This
1392 avoids warning for such calls to libiberty's xmalloc and
1394 Also avoid issuing the warning for calls to function named
1396 if (fn
&& fndecl_built_in_p (fn
, BUILT_IN_ALLOCA
)
1397 ? IDENTIFIER_LENGTH (DECL_NAME (fn
)) != 6
1398 : !lookup_attribute ("returns_nonnull",
1399 TYPE_ATTRIBUTES (fntype
)))
1400 warned
= warning_at (loc
, OPT_Walloc_zero
,
1401 "%Kargument %i value is zero",
1404 else if (tree_int_cst_lt (maxobjsize
, args
[i
]))
1406 /* G++ emits calls to ::operator new[](SIZE_MAX) in C++98
1407 mode and with -fno-exceptions as a way to indicate array
1408 size overflow. There's no good way to detect C++98 here
1409 so avoid diagnosing these calls for all C++ modes. */
1414 && DECL_IS_OPERATOR_NEW_P (fn
)
1415 && integer_all_onesp (args
[i
]))
1418 warned
= warning_at (loc
, OPT_Walloc_size_larger_than_
,
1419 "%Kargument %i value %qE exceeds "
1420 "maximum object size %E",
1421 exp
, idx
[i
] + 1, args
[i
], maxobjsize
);
1424 else if (TREE_CODE (args
[i
]) == SSA_NAME
1425 && get_size_range (args
[i
], argrange
[i
]))
1427 /* Verify that the argument's range is not negative (including
1428 upper bound of zero). */
1429 if (tree_int_cst_lt (argrange
[i
][0], integer_zero_node
)
1430 && tree_int_cst_le (argrange
[i
][1], integer_zero_node
))
1432 warned
= warning_at (loc
, OPT_Walloc_size_larger_than_
,
1433 "%Kargument %i range [%E, %E] is negative",
1435 argrange
[i
][0], argrange
[i
][1]);
1437 else if (tree_int_cst_lt (maxobjsize
, argrange
[i
][0]))
1439 warned
= warning_at (loc
, OPT_Walloc_size_larger_than_
,
1440 "%Kargument %i range [%E, %E] exceeds "
1441 "maximum object size %E",
1443 argrange
[i
][0], argrange
[i
][1],
1452 /* For a two-argument alloc_size, validate the product of the two
1453 arguments if both of their values or ranges are known. */
1454 if (!warned
&& tree_fits_uhwi_p (argrange
[0][0])
1455 && argrange
[1][0] && tree_fits_uhwi_p (argrange
[1][0])
1456 && !integer_onep (argrange
[0][0])
1457 && !integer_onep (argrange
[1][0]))
1459 /* Check for overflow in the product of a function decorated with
1460 attribute alloc_size (X, Y). */
1461 unsigned szprec
= TYPE_PRECISION (size_type_node
);
1462 wide_int x
= wi::to_wide (argrange
[0][0], szprec
);
1463 wide_int y
= wi::to_wide (argrange
[1][0], szprec
);
1465 wi::overflow_type vflow
;
1466 wide_int prod
= wi::umul (x
, y
, &vflow
);
1469 warned
= warning_at (loc
, OPT_Walloc_size_larger_than_
,
1470 "%Kproduct %<%E * %E%> of arguments %i and %i "
1471 "exceeds %<SIZE_MAX%>",
1472 exp
, argrange
[0][0], argrange
[1][0],
1473 idx
[0] + 1, idx
[1] + 1);
1474 else if (wi::ltu_p (wi::to_wide (maxobjsize
, szprec
), prod
))
1475 warned
= warning_at (loc
, OPT_Walloc_size_larger_than_
,
1476 "%Kproduct %<%E * %E%> of arguments %i and %i "
1477 "exceeds maximum object size %E",
1478 exp
, argrange
[0][0], argrange
[1][0],
1479 idx
[0] + 1, idx
[1] + 1,
1484 /* Print the full range of each of the two arguments to make
1485 it clear when it is, in fact, in a range and not constant. */
1486 if (argrange
[0][0] != argrange
[0][1])
1487 inform (loc
, "argument %i in the range [%E, %E]",
1488 idx
[0] + 1, argrange
[0][0], argrange
[0][1]);
1489 if (argrange
[1][0] != argrange
[1][1])
1490 inform (loc
, "argument %i in the range [%E, %E]",
1491 idx
[1] + 1, argrange
[1][0], argrange
[1][1]);
1497 location_t fnloc
= DECL_SOURCE_LOCATION (fn
);
1499 if (DECL_IS_BUILTIN (fn
))
1501 "in a call to built-in allocation function %qD", fn
);
1504 "in a call to allocation function %qD declared here", fn
);
1508 /* If EXPR refers to a character array or pointer declared attribute
1509 nonstring return a decl for that array or pointer and set *REF to
1510 the referenced enclosing object or pointer. Otherwise returns
1514 get_attr_nonstring_decl (tree expr
, tree
*ref
)
1517 tree var
= NULL_TREE
;
1518 if (TREE_CODE (decl
) == SSA_NAME
)
1520 gimple
*def
= SSA_NAME_DEF_STMT (decl
);
1522 if (is_gimple_assign (def
))
1524 tree_code code
= gimple_assign_rhs_code (def
);
1525 if (code
== ADDR_EXPR
1526 || code
== COMPONENT_REF
1527 || code
== VAR_DECL
)
1528 decl
= gimple_assign_rhs1 (def
);
1531 var
= SSA_NAME_VAR (decl
);
1534 if (TREE_CODE (decl
) == ADDR_EXPR
)
1535 decl
= TREE_OPERAND (decl
, 0);
1537 /* To simplify calling code, store the referenced DECL regardless of
1538 the attribute determined below, but avoid storing the SSA_NAME_VAR
1539 obtained above (it's not useful for dataflow purposes). */
1543 /* Use the SSA_NAME_VAR that was determined above to see if it's
1544 declared nonstring. Otherwise drill down into the referenced
1548 else if (TREE_CODE (decl
) == ARRAY_REF
)
1549 decl
= TREE_OPERAND (decl
, 0);
1550 else if (TREE_CODE (decl
) == COMPONENT_REF
)
1551 decl
= TREE_OPERAND (decl
, 1);
1552 else if (TREE_CODE (decl
) == MEM_REF
)
1553 return get_attr_nonstring_decl (TREE_OPERAND (decl
, 0), ref
);
1556 && lookup_attribute ("nonstring", DECL_ATTRIBUTES (decl
)))
1562 /* Warn about passing a non-string array/pointer to a function that
1563 expects a nul-terminated string argument. */
1566 maybe_warn_nonstring_arg (tree fndecl
, tree exp
)
1568 if (!fndecl
|| !fndecl_built_in_p (fndecl
, BUILT_IN_NORMAL
))
1571 if (TREE_NO_WARNING (exp
) || !warn_stringop_overflow
)
1574 /* Avoid clearly invalid calls (more checking done below). */
1575 unsigned nargs
= call_expr_nargs (exp
);
1579 /* The bound argument to a bounded string function like strncpy. */
1580 tree bound
= NULL_TREE
;
1582 /* The longest known or possible string argument to one of the comparison
1583 functions. If the length is less than the bound it is used instead.
1584 Since the length is only used for warning and not for code generation
1585 disable strict mode in the calls to get_range_strlen below. */
1586 tree maxlen
= NULL_TREE
;
1588 /* It's safe to call "bounded" string functions with a non-string
1589 argument since the functions provide an explicit bound for this
1590 purpose. The exception is strncat where the bound may refer to
1591 either the destination or the source. */
1592 int fncode
= DECL_FUNCTION_CODE (fndecl
);
1595 case BUILT_IN_STRCMP
:
1596 case BUILT_IN_STRNCMP
:
1597 case BUILT_IN_STRNCASECMP
:
1599 /* For these, if one argument refers to one or more of a set
1600 of string constants or arrays of known size, determine
1601 the range of their known or possible lengths and use it
1602 conservatively as the bound for the unbounded function,
1603 and to adjust the range of the bound of the bounded ones. */
1604 for (unsigned argno
= 0;
1605 argno
< MIN (nargs
, 2)
1606 && !(maxlen
&& TREE_CODE (maxlen
) == INTEGER_CST
); argno
++)
1608 tree arg
= CALL_EXPR_ARG (exp
, argno
);
1609 if (!get_attr_nonstring_decl (arg
))
1611 c_strlen_data lendata
= { };
1612 /* Set MAXBOUND to an arbitrary non-null non-integer
1613 node as a request to have it set to the length of
1614 the longest string in a PHI. */
1615 lendata
.maxbound
= arg
;
1616 get_range_strlen (arg
, &lendata
, /* eltsize = */ 1);
1617 maxlen
= lendata
.maxbound
;
1623 case BUILT_IN_STRNCAT
:
1624 case BUILT_IN_STPNCPY
:
1625 case BUILT_IN_STRNCPY
:
1627 bound
= CALL_EXPR_ARG (exp
, 2);
1630 case BUILT_IN_STRNDUP
:
1632 bound
= CALL_EXPR_ARG (exp
, 1);
1635 case BUILT_IN_STRNLEN
:
1637 tree arg
= CALL_EXPR_ARG (exp
, 0);
1638 if (!get_attr_nonstring_decl (arg
))
1640 c_strlen_data lendata
= { };
1641 /* Set MAXBOUND to an arbitrary non-null non-integer
1642 node as a request to have it set to the length of
1643 the longest string in a PHI. */
1644 lendata
.maxbound
= arg
;
1645 get_range_strlen (arg
, &lendata
, /* eltsize = */ 1);
1646 maxlen
= lendata
.maxbound
;
1649 bound
= CALL_EXPR_ARG (exp
, 1);
1657 /* Determine the range of the bound argument (if specified). */
1658 tree bndrng
[2] = { NULL_TREE
, NULL_TREE
};
1662 get_size_range (bound
, bndrng
);
1665 location_t loc
= EXPR_LOCATION (exp
);
1669 /* Diagnose excessive bound prior the adjustment below and
1670 regardless of attribute nonstring. */
1671 tree maxobjsize
= max_object_size ();
1672 if (tree_int_cst_lt (maxobjsize
, bndrng
[0]))
1674 if (tree_int_cst_equal (bndrng
[0], bndrng
[1]))
1675 warning_at (loc
, OPT_Wstringop_overflow_
,
1676 "%K%qD specified bound %E "
1677 "exceeds maximum object size %E",
1678 exp
, fndecl
, bndrng
[0], maxobjsize
);
1680 warning_at (loc
, OPT_Wstringop_overflow_
,
1681 "%K%qD specified bound [%E, %E] "
1682 "exceeds maximum object size %E",
1683 exp
, fndecl
, bndrng
[0], bndrng
[1], maxobjsize
);
1688 if (maxlen
&& !integer_all_onesp (maxlen
))
1690 /* Add one for the nul. */
1691 maxlen
= const_binop (PLUS_EXPR
, TREE_TYPE (maxlen
), maxlen
,
1696 /* Conservatively use the upper bound of the lengths for
1697 both the lower and the upper bound of the operation. */
1700 bound
= void_type_node
;
1704 /* Replace the bound on the operation with the upper bound
1705 of the length of the string if the latter is smaller. */
1706 if (tree_int_cst_lt (maxlen
, bndrng
[0]))
1708 else if (tree_int_cst_lt (maxlen
, bndrng
[1]))
1713 /* Iterate over the built-in function's formal arguments and check
1714 each const char* against the actual argument. If the actual
1715 argument is declared attribute non-string issue a warning unless
1716 the argument's maximum length is bounded. */
1717 function_args_iterator it
;
1718 function_args_iter_init (&it
, TREE_TYPE (fndecl
));
1720 for (unsigned argno
= 0; ; ++argno
, function_args_iter_next (&it
))
1722 /* Avoid iterating past the declared argument in a call
1723 to function declared without a prototype. */
1727 tree argtype
= function_args_iter_cond (&it
);
1731 if (TREE_CODE (argtype
) != POINTER_TYPE
)
1734 argtype
= TREE_TYPE (argtype
);
1736 if (TREE_CODE (argtype
) != INTEGER_TYPE
1737 || !TYPE_READONLY (argtype
))
1740 argtype
= TYPE_MAIN_VARIANT (argtype
);
1741 if (argtype
!= char_type_node
)
1744 tree callarg
= CALL_EXPR_ARG (exp
, argno
);
1745 if (TREE_CODE (callarg
) == ADDR_EXPR
)
1746 callarg
= TREE_OPERAND (callarg
, 0);
1748 /* See if the destination is declared with attribute "nonstring". */
1749 tree decl
= get_attr_nonstring_decl (callarg
);
1753 /* The maximum number of array elements accessed. */
1754 offset_int wibnd
= 0;
1756 if (argno
&& fncode
== BUILT_IN_STRNCAT
)
1758 /* See if the bound in strncat is derived from the length
1759 of the strlen of the destination (as it's expected to be).
1760 If so, reset BOUND and FNCODE to trigger a warning. */
1761 tree dstarg
= CALL_EXPR_ARG (exp
, 0);
1762 if (is_strlen_related_p (dstarg
, bound
))
1764 /* The bound applies to the destination, not to the source,
1765 so reset these to trigger a warning without mentioning
1771 /* Use the upper bound of the range for strncat. */
1772 wibnd
= wi::to_offset (bndrng
[1]);
1775 /* Use the lower bound of the range for functions other than
1777 wibnd
= wi::to_offset (bndrng
[0]);
1779 /* Determine the size of the argument array if it is one. */
1780 offset_int asize
= wibnd
;
1781 bool known_size
= false;
1782 tree type
= TREE_TYPE (decl
);
1784 /* Determine the array size. For arrays of unknown bound and
1785 pointers reset BOUND to trigger the appropriate warning. */
1786 if (TREE_CODE (type
) == ARRAY_TYPE
)
1788 if (tree arrbnd
= TYPE_DOMAIN (type
))
1790 if ((arrbnd
= TYPE_MAX_VALUE (arrbnd
)))
1792 asize
= wi::to_offset (arrbnd
) + 1;
1796 else if (bound
== void_type_node
)
1799 else if (bound
== void_type_node
)
1802 /* In a call to strncat with a bound in a range whose lower but
1803 not upper bound is less than the array size, reset ASIZE to
1804 be the same as the bound and the other variable to trigger
1805 the apprpriate warning below. */
1806 if (fncode
== BUILT_IN_STRNCAT
1807 && bndrng
[0] != bndrng
[1]
1808 && wi::ltu_p (wi::to_offset (bndrng
[0]), asize
)
1810 || wi::ltu_p (asize
, wibnd
)))
1817 bool warned
= false;
1819 auto_diagnostic_group d
;
1820 if (wi::ltu_p (asize
, wibnd
))
1822 if (bndrng
[0] == bndrng
[1])
1823 warned
= warning_at (loc
, OPT_Wstringop_overflow_
,
1824 "%qD argument %i declared attribute "
1825 "%<nonstring%> is smaller than the specified "
1827 fndecl
, argno
+ 1, wibnd
.to_uhwi ());
1828 else if (wi::ltu_p (asize
, wi::to_offset (bndrng
[0])))
1829 warned
= warning_at (loc
, OPT_Wstringop_overflow_
,
1830 "%qD argument %i declared attribute "
1831 "%<nonstring%> is smaller than "
1832 "the specified bound [%E, %E]",
1833 fndecl
, argno
+ 1, bndrng
[0], bndrng
[1]);
1835 warned
= warning_at (loc
, OPT_Wstringop_overflow_
,
1836 "%qD argument %i declared attribute "
1837 "%<nonstring%> may be smaller than "
1838 "the specified bound [%E, %E]",
1839 fndecl
, argno
+ 1, bndrng
[0], bndrng
[1]);
1841 else if (fncode
== BUILT_IN_STRNCAT
)
1842 ; /* Avoid warning for calls to strncat() when the bound
1843 is equal to the size of the non-string argument. */
1845 warned
= warning_at (loc
, OPT_Wstringop_overflow_
,
1846 "%qD argument %i declared attribute %<nonstring%>",
1850 inform (DECL_SOURCE_LOCATION (decl
),
1851 "argument %qD declared here", decl
);
1855 /* Issue an error if CALL_EXPR was flagged as requiring
1856 tall-call optimization. */
1859 maybe_complain_about_tail_call (tree call_expr
, const char *reason
)
1861 gcc_assert (TREE_CODE (call_expr
) == CALL_EXPR
);
1862 if (!CALL_EXPR_MUST_TAIL_CALL (call_expr
))
1865 error_at (EXPR_LOCATION (call_expr
), "cannot tail-call: %s", reason
);
1868 /* Returns the type of the argument ARGNO to function with type FNTYPE
1869 or null when the typoe cannot be determined or no such argument exists. */
1872 fntype_argno_type (tree fntype
, unsigned argno
)
1874 if (!prototype_p (fntype
))
1878 function_args_iterator it
;
1879 FOREACH_FUNCTION_ARGS (fntype
, argtype
, it
)
1886 /* Helper to append the "rdwr" attribute specification described
1887 by ACCESS to the array ATTRSTR with size STRSIZE. Used in
1891 append_attrname (const std::pair
<int, attr_access
> &access
,
1892 char *attrstr
, size_t strsize
)
1894 /* Append the relevant attribute to the string. This (deliberately)
1895 appends the attribute pointer operand even when none was specified. */
1896 size_t len
= strlen (attrstr
);
1898 const char* const atname
1899 = (access
.second
.mode
== attr_access::read_only
1901 : (access
.second
.mode
== attr_access::write_only
1903 : (access
.second
.mode
== attr_access::read_write
1904 ? "read_write" : "none")));
1906 const char *sep
= len
? ", " : "";
1908 if (access
.second
.sizarg
== UINT_MAX
)
1909 snprintf (attrstr
+ len
, strsize
- len
,
1910 "%s%s (%i)", sep
, atname
,
1911 access
.second
.ptrarg
+ 1);
1913 snprintf (attrstr
+ len
, strsize
- len
,
1914 "%s%s (%i, %i)", sep
, atname
,
1915 access
.second
.ptrarg
+ 1, access
.second
.sizarg
+ 1);
1918 /* Iterate over attribute access read-only, read-write, and write-only
1919 arguments and diagnose past-the-end accesses and related problems
1920 in the function call EXP. */
1923 maybe_warn_rdwr_sizes (rdwr_map
*rwm
, tree exp
)
1925 tree fndecl
= NULL_TREE
;
1926 tree fntype
= NULL_TREE
;
1927 if (tree fnaddr
= CALL_EXPR_FN (exp
))
1929 if (TREE_CODE (fnaddr
) == ADDR_EXPR
)
1931 fndecl
= TREE_OPERAND (fnaddr
, 0);
1932 fntype
= TREE_TYPE (fndecl
);
1935 fntype
= TREE_TYPE (TREE_TYPE (fnaddr
));
1941 auto_diagnostic_group adg
;
1943 /* A string describing the attributes that the warnings issued by this
1944 function apply to. Used to print one informational note per function
1945 call, rather than one per warning. That reduces clutter. */
1949 for (rdwr_map::iterator it
= rwm
->begin (); it
!= rwm
->end (); ++it
)
1951 std::pair
<int, attr_access
> access
= *it
;
1953 /* Get the function call arguments corresponding to the attribute's
1954 positional arguments. When both arguments have been specified
1955 there will be two entries in *RWM, one for each. They are
1956 cross-referenced by their respective argument numbers in
1957 ACCESS.PTRARG and ACCESS.SIZARG. */
1958 const int ptridx
= access
.second
.ptrarg
;
1959 const int sizidx
= access
.second
.sizarg
;
1961 gcc_assert (ptridx
!= -1);
1962 gcc_assert (access
.first
== ptridx
|| access
.first
== sizidx
);
1964 /* The pointer is set to null for the entry corresponding to
1965 the size argument. Skip it. It's handled when the entry
1966 corresponding to the pointer argument comes up. */
1967 if (!access
.second
.ptr
)
1970 tree argtype
= fntype_argno_type (fntype
, ptridx
);
1971 argtype
= TREE_TYPE (argtype
);
1976 /* If only the pointer attribute operand was specified
1977 and not size, set SIZE to the size of one element of
1978 the pointed to type to detect smaller objects (null
1979 pointers are diagnosed in this case only if
1980 the pointer is also declared with attribute nonnull. */
1981 size
= size_one_node
;
1984 size
= rwm
->get (sizidx
)->size
;
1986 tree ptr
= access
.second
.ptr
;
1987 tree sizrng
[2] = { size_zero_node
, build_all_ones_cst (sizetype
) };
1988 if (get_size_range (size
, sizrng
, true)
1989 && tree_int_cst_sgn (sizrng
[0]) < 0
1990 && tree_int_cst_sgn (sizrng
[1]) < 0)
1992 /* Warn about negative sizes. */
1993 bool warned
= false;
1994 location_t loc
= EXPR_LOCATION (exp
);
1995 if (tree_int_cst_equal (sizrng
[0], sizrng
[1]))
1996 warned
= warning_at (loc
, OPT_Wstringop_overflow_
,
1997 "%Kargument %i value %E is negative",
1998 exp
, sizidx
+ 1, size
);
2000 warned
= warning_at (loc
, OPT_Wstringop_overflow_
,
2001 "%Kargument %i range [%E, %E] is negative",
2002 exp
, sizidx
+ 1, sizrng
[0], sizrng
[1]);
2005 append_attrname (access
, attrstr
, sizeof attrstr
);
2006 /* Avoid warning again for the same attribute. */
2011 if (tree_int_cst_sgn (sizrng
[0]) >= 0)
2013 if (COMPLETE_TYPE_P (argtype
))
2015 /* Multiple SIZE by the size of the type the pointer
2016 argument points to. If it's incomplete the size
2019 if (tree argsize
= TYPE_SIZE_UNIT (argtype
))
2020 if (TREE_CODE (argsize
) == INTEGER_CST
)
2022 const int prec
= TYPE_PRECISION (sizetype
);
2023 wide_int minsize
= wi::to_wide (sizrng
[0], prec
);
2024 minsize
*= wi::to_wide (argsize
, prec
);
2025 size
= wide_int_to_tree (sizetype
, minsize
);
2033 && integer_zerop (ptr
)
2034 && tree_int_cst_sgn (sizrng
[0]) > 0)
2036 /* Warn about null pointers with positive sizes. This is
2037 different from also declaring the pointer argument with
2038 attribute nonnull when the function accepts null pointers
2039 only when the corresponding size is zero. */
2040 bool warned
= false;
2041 const location_t loc
= EXPR_LOC_OR_LOC (ptr
, EXPR_LOCATION (exp
));
2042 if (tree_int_cst_equal (sizrng
[0], sizrng
[1]))
2043 warned
= warning_at (loc
, OPT_Wnonnull
,
2044 "%Kargument %i is null but the corresponding "
2045 "size argument %i value is %E",
2046 exp
, ptridx
+ 1, sizidx
+ 1, size
);
2048 warned
= warning_at (loc
, OPT_Wnonnull
,
2049 "%Kargument %i is null but the corresponding "
2050 "size argument %i range is [%E, %E]",
2051 exp
, ptridx
+ 1, sizidx
+ 1,
2052 sizrng
[0], sizrng
[1]);
2055 append_attrname (access
, attrstr
, sizeof attrstr
);
2056 /* Avoid warning again for the same attribute. */
2061 tree objsize
= compute_objsize (ptr
, 0);
2064 if (access
.second
.mode
== attr_access::write_only
)
2066 /* For a write-only argument there is no source. */
2067 srcsize
= NULL_TREE
;
2071 /* For read-only and read-write attributes also set the source
2074 if (access
.second
.mode
== attr_access::read_only
2075 || access
.second
.mode
== attr_access::none
)
2077 /* For a read-only attribute there is no destination so
2078 clear OBJSIZE. This emits "reading N bytes" kind of
2079 diagnostics instead of the "writing N bytes" kind,
2080 unless MODE is none. */
2081 objsize
= NULL_TREE
;
2085 /* Clear the no-warning bit in case it was set in a prior
2086 iteration so that accesses via different arguments are
2088 TREE_NO_WARNING (exp
) = false;
2089 check_access (exp
, NULL_TREE
, NULL_TREE
, size
, /*maxread=*/ NULL_TREE
,
2090 srcsize
, objsize
, access
.second
.mode
!= attr_access::none
);
2092 if (TREE_NO_WARNING (exp
))
2093 /* If check_access issued a warning above, append the relevant
2094 attribute to the string. */
2095 append_attrname (access
, attrstr
, sizeof attrstr
);
2102 inform (DECL_SOURCE_LOCATION (fndecl
),
2103 "in a call to function %qD declared with attribute %qs",
2106 inform (EXPR_LOCATION (fndecl
),
2107 "in a call with type %qT and attribute %qs",
2110 /* Set the bit in case if was cleared and not set above. */
2111 TREE_NO_WARNING (exp
) = true;
2114 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
2117 NUM_ACTUALS is the total number of parameters.
2119 N_NAMED_ARGS is the total number of named arguments.
2121 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
2124 FNDECL is the tree code for the target of this call (if known)
2126 ARGS_SO_FAR holds state needed by the target to know where to place
2129 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
2130 for arguments which are passed in registers.
2132 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
2133 and may be modified by this routine.
2135 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
2136 flags which may be modified by this routine.
2138 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
2139 that requires allocation of stack space.
2141 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
2142 the thunked-to function. */
2145 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED
,
2146 struct arg_data
*args
,
2147 struct args_size
*args_size
,
2148 int n_named_args ATTRIBUTE_UNUSED
,
2149 tree exp
, tree struct_value_addr_value
,
2150 tree fndecl
, tree fntype
,
2151 cumulative_args_t args_so_far
,
2152 int reg_parm_stack_space
,
2153 rtx
*old_stack_level
,
2154 poly_int64_pod
*old_pending_adj
,
2155 int *must_preallocate
, int *ecf_flags
,
2156 bool *may_tailcall
, bool call_from_thunk_p
)
2158 CUMULATIVE_ARGS
*args_so_far_pnt
= get_cumulative_args (args_so_far
);
2159 location_t loc
= EXPR_LOCATION (exp
);
2161 /* Count arg position in order args appear. */
2166 args_size
->constant
= 0;
2169 bitmap_obstack_initialize (NULL
);
2171 /* In this loop, we consider args in the order they are written.
2172 We fill up ARGS from the back. */
2174 i
= num_actuals
- 1;
2177 call_expr_arg_iterator iter
;
2179 bitmap slots
= NULL
;
2181 if (struct_value_addr_value
)
2183 args
[j
].tree_value
= struct_value_addr_value
;
2187 FOR_EACH_CALL_EXPR_ARG (arg
, iter
, exp
)
2189 tree argtype
= TREE_TYPE (arg
);
2191 if (targetm
.calls
.split_complex_arg
2193 && TREE_CODE (argtype
) == COMPLEX_TYPE
2194 && targetm
.calls
.split_complex_arg (argtype
))
2196 tree subtype
= TREE_TYPE (argtype
);
2197 args
[j
].tree_value
= build1 (REALPART_EXPR
, subtype
, arg
);
2199 args
[j
].tree_value
= build1 (IMAGPART_EXPR
, subtype
, arg
);
2202 args
[j
].tree_value
= arg
;
2208 BITMAP_FREE (slots
);
2211 bitmap_obstack_release (NULL
);
2213 /* Extract attribute alloc_size from the type of the called expression
2214 (which could be a function or a function pointer) and if set, store
2215 the indices of the corresponding arguments in ALLOC_IDX, and then
2216 the actual argument(s) at those indices in ALLOC_ARGS. */
2217 int alloc_idx
[2] = { -1, -1 };
2218 if (tree alloc_size
= lookup_attribute ("alloc_size",
2219 TYPE_ATTRIBUTES (fntype
)))
2221 tree args
= TREE_VALUE (alloc_size
);
2222 alloc_idx
[0] = TREE_INT_CST_LOW (TREE_VALUE (args
)) - 1;
2223 if (TREE_CHAIN (args
))
2224 alloc_idx
[1] = TREE_INT_CST_LOW (TREE_VALUE (TREE_CHAIN (args
))) - 1;
2227 /* Array for up to the two attribute alloc_size arguments. */
2228 tree alloc_args
[] = { NULL_TREE
, NULL_TREE
};
2230 /* Map of attribute accewss specifications for function arguments. */
2232 init_attr_rdwr_indices (&rdwr_idx
, fntype
);
2234 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
2235 for (argpos
= 0; argpos
< num_actuals
; i
--, argpos
++)
2237 tree type
= TREE_TYPE (args
[i
].tree_value
);
2240 /* Replace erroneous argument with constant zero. */
2241 if (type
== error_mark_node
|| !COMPLETE_TYPE_P (type
))
2242 args
[i
].tree_value
= integer_zero_node
, type
= integer_type_node
;
2244 /* If TYPE is a transparent union or record, pass things the way
2245 we would pass the first field of the union or record. We have
2246 already verified that the modes are the same. */
2247 if (RECORD_OR_UNION_TYPE_P (type
) && TYPE_TRANSPARENT_AGGR (type
))
2248 type
= TREE_TYPE (first_field (type
));
2250 /* Decide where to pass this arg.
2252 args[i].reg is nonzero if all or part is passed in registers.
2254 args[i].partial is nonzero if part but not all is passed in registers,
2255 and the exact value says how many bytes are passed in registers.
2257 args[i].pass_on_stack is nonzero if the argument must at least be
2258 computed on the stack. It may then be loaded back into registers
2259 if args[i].reg is nonzero.
2261 These decisions are driven by the FUNCTION_... macros and must agree
2262 with those made by function.c. */
2264 /* See if this argument should be passed by invisible reference. */
2265 function_arg_info
arg (type
, argpos
< n_named_args
);
2266 if (pass_by_reference (args_so_far_pnt
, arg
))
2269 tree base
= NULL_TREE
;
2271 callee_copies
= reference_callee_copied (args_so_far_pnt
, arg
);
2273 /* If we're compiling a thunk, pass through invisible references
2274 instead of making a copy. */
2275 if (call_from_thunk_p
2277 && !TREE_ADDRESSABLE (type
)
2278 && (base
= get_base_address (args
[i
].tree_value
))
2279 && TREE_CODE (base
) != SSA_NAME
2280 && (!DECL_P (base
) || MEM_P (DECL_RTL (base
)))))
2282 /* We may have turned the parameter value into an SSA name.
2283 Go back to the original parameter so we can take the
2285 if (TREE_CODE (args
[i
].tree_value
) == SSA_NAME
)
2287 gcc_assert (SSA_NAME_IS_DEFAULT_DEF (args
[i
].tree_value
));
2288 args
[i
].tree_value
= SSA_NAME_VAR (args
[i
].tree_value
);
2289 gcc_assert (TREE_CODE (args
[i
].tree_value
) == PARM_DECL
);
2291 /* Argument setup code may have copied the value to register. We
2292 revert that optimization now because the tail call code must
2293 use the original location. */
2294 if (TREE_CODE (args
[i
].tree_value
) == PARM_DECL
2295 && !MEM_P (DECL_RTL (args
[i
].tree_value
))
2296 && DECL_INCOMING_RTL (args
[i
].tree_value
)
2297 && MEM_P (DECL_INCOMING_RTL (args
[i
].tree_value
)))
2298 set_decl_rtl (args
[i
].tree_value
,
2299 DECL_INCOMING_RTL (args
[i
].tree_value
));
2301 mark_addressable (args
[i
].tree_value
);
2303 /* We can't use sibcalls if a callee-copied argument is
2304 stored in the current function's frame. */
2305 if (!call_from_thunk_p
&& DECL_P (base
) && !TREE_STATIC (base
))
2307 *may_tailcall
= false;
2308 maybe_complain_about_tail_call (exp
,
2309 "a callee-copied argument is"
2310 " stored in the current"
2311 " function's frame");
2314 args
[i
].tree_value
= build_fold_addr_expr_loc (loc
,
2315 args
[i
].tree_value
);
2316 type
= TREE_TYPE (args
[i
].tree_value
);
2318 if (*ecf_flags
& ECF_CONST
)
2319 *ecf_flags
&= ~(ECF_CONST
| ECF_LOOPING_CONST_OR_PURE
);
2323 /* We make a copy of the object and pass the address to the
2324 function being called. */
2327 if (!COMPLETE_TYPE_P (type
)
2328 || TREE_CODE (TYPE_SIZE_UNIT (type
)) != INTEGER_CST
2329 || (flag_stack_check
== GENERIC_STACK_CHECK
2330 && compare_tree_int (TYPE_SIZE_UNIT (type
),
2331 STACK_CHECK_MAX_VAR_SIZE
) > 0))
2333 /* This is a variable-sized object. Make space on the stack
2335 rtx size_rtx
= expr_size (args
[i
].tree_value
);
2337 if (*old_stack_level
== 0)
2339 emit_stack_save (SAVE_BLOCK
, old_stack_level
);
2340 *old_pending_adj
= pending_stack_adjust
;
2341 pending_stack_adjust
= 0;
2344 /* We can pass TRUE as the 4th argument because we just
2345 saved the stack pointer and will restore it right after
2347 copy
= allocate_dynamic_stack_space (size_rtx
,
2350 max_int_size_in_bytes
2353 copy
= gen_rtx_MEM (BLKmode
, copy
);
2354 set_mem_attributes (copy
, type
, 1);
2357 copy
= assign_temp (type
, 1, 0);
2359 store_expr (args
[i
].tree_value
, copy
, 0, false, false);
2361 /* Just change the const function to pure and then let
2362 the next test clear the pure based on
2364 if (*ecf_flags
& ECF_CONST
)
2366 *ecf_flags
&= ~ECF_CONST
;
2367 *ecf_flags
|= ECF_PURE
;
2370 if (!callee_copies
&& *ecf_flags
& ECF_PURE
)
2371 *ecf_flags
&= ~(ECF_PURE
| ECF_LOOPING_CONST_OR_PURE
);
2374 = build_fold_addr_expr_loc (loc
, make_tree (type
, copy
));
2375 type
= TREE_TYPE (args
[i
].tree_value
);
2376 *may_tailcall
= false;
2377 maybe_complain_about_tail_call (exp
,
2378 "argument must be passed"
2381 arg
.pass_by_reference
= true;
2384 unsignedp
= TYPE_UNSIGNED (type
);
2387 = promote_function_mode (type
, TYPE_MODE (type
), &unsignedp
,
2388 fndecl
? TREE_TYPE (fndecl
) : fntype
, 0);
2390 args
[i
].unsignedp
= unsignedp
;
2391 args
[i
].mode
= arg
.mode
;
2393 targetm
.calls
.warn_parameter_passing_abi (args_so_far
, type
);
2395 args
[i
].reg
= targetm
.calls
.function_arg (args_so_far
, arg
);
2397 if (args
[i
].reg
&& CONST_INT_P (args
[i
].reg
))
2400 /* If this is a sibling call and the machine has register windows, the
2401 register window has to be unwinded before calling the routine, so
2402 arguments have to go into the incoming registers. */
2403 if (targetm
.calls
.function_incoming_arg
!= targetm
.calls
.function_arg
)
2404 args
[i
].tail_call_reg
2405 = targetm
.calls
.function_incoming_arg (args_so_far
, arg
);
2407 args
[i
].tail_call_reg
= args
[i
].reg
;
2410 args
[i
].partial
= targetm
.calls
.arg_partial_bytes (args_so_far
, arg
);
2412 args
[i
].pass_on_stack
= targetm
.calls
.must_pass_in_stack (arg
);
2414 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
2415 it means that we are to pass this arg in the register(s) designated
2416 by the PARALLEL, but also to pass it in the stack. */
2417 if (args
[i
].reg
&& GET_CODE (args
[i
].reg
) == PARALLEL
2418 && XEXP (XVECEXP (args
[i
].reg
, 0, 0), 0) == 0)
2419 args
[i
].pass_on_stack
= 1;
2421 /* If this is an addressable type, we must preallocate the stack
2422 since we must evaluate the object into its final location.
2424 If this is to be passed in both registers and the stack, it is simpler
2426 if (TREE_ADDRESSABLE (type
)
2427 || (args
[i
].pass_on_stack
&& args
[i
].reg
!= 0))
2428 *must_preallocate
= 1;
2430 /* Compute the stack-size of this argument. */
2431 if (args
[i
].reg
== 0 || args
[i
].partial
!= 0
2432 || reg_parm_stack_space
> 0
2433 || args
[i
].pass_on_stack
)
2434 locate_and_pad_parm (arg
.mode
, type
,
2435 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2440 reg_parm_stack_space
,
2441 args
[i
].pass_on_stack
? 0 : args
[i
].partial
,
2442 fndecl
, args_size
, &args
[i
].locate
);
2443 #ifdef BLOCK_REG_PADDING
2445 /* The argument is passed entirely in registers. See at which
2446 end it should be padded. */
2447 args
[i
].locate
.where_pad
=
2448 BLOCK_REG_PADDING (arg
.mode
, type
,
2449 int_size_in_bytes (type
) <= UNITS_PER_WORD
);
2452 /* Update ARGS_SIZE, the total stack space for args so far. */
2454 args_size
->constant
+= args
[i
].locate
.size
.constant
;
2455 if (args
[i
].locate
.size
.var
)
2456 ADD_PARM_SIZE (*args_size
, args
[i
].locate
.size
.var
);
2458 /* Increment ARGS_SO_FAR, which has info about which arg-registers
2459 have been used, etc. */
2461 /* ??? Traditionally we've passed TYPE_MODE here, instead of the
2462 promoted_mode used for function_arg above. However, the
2463 corresponding handling of incoming arguments in function.c
2464 does pass the promoted mode. */
2465 arg
.mode
= TYPE_MODE (type
);
2466 targetm
.calls
.function_arg_advance (args_so_far
, arg
);
2468 /* Store argument values for functions decorated with attribute
2470 if (argpos
== alloc_idx
[0])
2471 alloc_args
[0] = args
[i
].tree_value
;
2472 else if (argpos
== alloc_idx
[1])
2473 alloc_args
[1] = args
[i
].tree_value
;
2475 /* Save the actual argument that corresponds to the access attribute
2476 operand for later processing. */
2477 if (attr_access
*access
= rdwr_idx
.get (argpos
))
2479 if (POINTER_TYPE_P (type
))
2481 access
->ptr
= args
[i
].tree_value
;
2482 gcc_assert (access
->size
== NULL_TREE
);
2486 access
->size
= args
[i
].tree_value
;
2487 gcc_assert (access
->ptr
== NULL_TREE
);
2494 /* Check the arguments of functions decorated with attribute
2496 maybe_warn_alloc_args_overflow (fndecl
, exp
, alloc_args
, alloc_idx
);
2499 /* Detect passing non-string arguments to functions expecting
2500 nul-terminated strings. */
2501 maybe_warn_nonstring_arg (fndecl
, exp
);
2503 /* Check attribute access arguments. */
2504 maybe_warn_rdwr_sizes (&rdwr_idx
, exp
);
2507 /* Update ARGS_SIZE to contain the total size for the argument block.
2508 Return the original constant component of the argument block's size.
2510 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
2511 for arguments passed in registers. */
2514 compute_argument_block_size (int reg_parm_stack_space
,
2515 struct args_size
*args_size
,
2516 tree fndecl ATTRIBUTE_UNUSED
,
2517 tree fntype ATTRIBUTE_UNUSED
,
2518 int preferred_stack_boundary ATTRIBUTE_UNUSED
)
2520 poly_int64 unadjusted_args_size
= args_size
->constant
;
2522 /* For accumulate outgoing args mode we don't need to align, since the frame
2523 will be already aligned. Align to STACK_BOUNDARY in order to prevent
2524 backends from generating misaligned frame sizes. */
2525 if (ACCUMULATE_OUTGOING_ARGS
&& preferred_stack_boundary
> STACK_BOUNDARY
)
2526 preferred_stack_boundary
= STACK_BOUNDARY
;
2528 /* Compute the actual size of the argument block required. The variable
2529 and constant sizes must be combined, the size may have to be rounded,
2530 and there may be a minimum required size. */
2534 args_size
->var
= ARGS_SIZE_TREE (*args_size
);
2535 args_size
->constant
= 0;
2537 preferred_stack_boundary
/= BITS_PER_UNIT
;
2538 if (preferred_stack_boundary
> 1)
2540 /* We don't handle this case yet. To handle it correctly we have
2541 to add the delta, round and subtract the delta.
2542 Currently no machine description requires this support. */
2543 gcc_assert (multiple_p (stack_pointer_delta
,
2544 preferred_stack_boundary
));
2545 args_size
->var
= round_up (args_size
->var
, preferred_stack_boundary
);
2548 if (reg_parm_stack_space
> 0)
2551 = size_binop (MAX_EXPR
, args_size
->var
,
2552 ssize_int (reg_parm_stack_space
));
2554 /* The area corresponding to register parameters is not to count in
2555 the size of the block we need. So make the adjustment. */
2556 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl
? fntype
: TREE_TYPE (fndecl
))))
2558 = size_binop (MINUS_EXPR
, args_size
->var
,
2559 ssize_int (reg_parm_stack_space
));
2564 preferred_stack_boundary
/= BITS_PER_UNIT
;
2565 if (preferred_stack_boundary
< 1)
2566 preferred_stack_boundary
= 1;
2567 args_size
->constant
= (aligned_upper_bound (args_size
->constant
2568 + stack_pointer_delta
,
2569 preferred_stack_boundary
)
2570 - stack_pointer_delta
);
2572 args_size
->constant
= upper_bound (args_size
->constant
,
2573 reg_parm_stack_space
);
2575 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl
? fntype
: TREE_TYPE (fndecl
))))
2576 args_size
->constant
-= reg_parm_stack_space
;
2578 return unadjusted_args_size
;
2581 /* Precompute parameters as needed for a function call.
2583 FLAGS is mask of ECF_* constants.
2585 NUM_ACTUALS is the number of arguments.
2587 ARGS is an array containing information for each argument; this
2588 routine fills in the INITIAL_VALUE and VALUE fields for each
2589 precomputed argument. */
2592 precompute_arguments (int num_actuals
, struct arg_data
*args
)
2596 /* If this is a libcall, then precompute all arguments so that we do not
2597 get extraneous instructions emitted as part of the libcall sequence. */
2599 /* If we preallocated the stack space, and some arguments must be passed
2600 on the stack, then we must precompute any parameter which contains a
2601 function call which will store arguments on the stack.
2602 Otherwise, evaluating the parameter may clobber previous parameters
2603 which have already been stored into the stack. (we have code to avoid
2604 such case by saving the outgoing stack arguments, but it results in
2606 if (!ACCUMULATE_OUTGOING_ARGS
)
2609 for (i
= 0; i
< num_actuals
; i
++)
2614 if (TREE_CODE (args
[i
].tree_value
) != CALL_EXPR
)
2617 /* If this is an addressable type, we cannot pre-evaluate it. */
2618 type
= TREE_TYPE (args
[i
].tree_value
);
2619 gcc_assert (!TREE_ADDRESSABLE (type
));
2621 args
[i
].initial_value
= args
[i
].value
2622 = expand_normal (args
[i
].tree_value
);
2624 mode
= TYPE_MODE (type
);
2625 if (mode
!= args
[i
].mode
)
2627 int unsignedp
= args
[i
].unsignedp
;
2629 = convert_modes (args
[i
].mode
, mode
,
2630 args
[i
].value
, args
[i
].unsignedp
);
2632 /* CSE will replace this only if it contains args[i].value
2633 pseudo, so convert it down to the declared mode using
2635 if (REG_P (args
[i
].value
)
2636 && GET_MODE_CLASS (args
[i
].mode
) == MODE_INT
2637 && promote_mode (type
, mode
, &unsignedp
) != args
[i
].mode
)
2639 args
[i
].initial_value
2640 = gen_lowpart_SUBREG (mode
, args
[i
].value
);
2641 SUBREG_PROMOTED_VAR_P (args
[i
].initial_value
) = 1;
2642 SUBREG_PROMOTED_SET (args
[i
].initial_value
, args
[i
].unsignedp
);
2648 /* Given the current state of MUST_PREALLOCATE and information about
2649 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
2650 compute and return the final value for MUST_PREALLOCATE. */
2653 finalize_must_preallocate (int must_preallocate
, int num_actuals
,
2654 struct arg_data
*args
, struct args_size
*args_size
)
2656 /* See if we have or want to preallocate stack space.
2658 If we would have to push a partially-in-regs parm
2659 before other stack parms, preallocate stack space instead.
2661 If the size of some parm is not a multiple of the required stack
2662 alignment, we must preallocate.
2664 If the total size of arguments that would otherwise create a copy in
2665 a temporary (such as a CALL) is more than half the total argument list
2666 size, preallocation is faster.
2668 Another reason to preallocate is if we have a machine (like the m88k)
2669 where stack alignment is required to be maintained between every
2670 pair of insns, not just when the call is made. However, we assume here
2671 that such machines either do not have push insns (and hence preallocation
2672 would occur anyway) or the problem is taken care of with
2675 if (! must_preallocate
)
2677 int partial_seen
= 0;
2678 poly_int64 copy_to_evaluate_size
= 0;
2681 for (i
= 0; i
< num_actuals
&& ! must_preallocate
; i
++)
2683 if (args
[i
].partial
> 0 && ! args
[i
].pass_on_stack
)
2685 else if (partial_seen
&& args
[i
].reg
== 0)
2686 must_preallocate
= 1;
2688 if (TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)) == BLKmode
2689 && (TREE_CODE (args
[i
].tree_value
) == CALL_EXPR
2690 || TREE_CODE (args
[i
].tree_value
) == TARGET_EXPR
2691 || TREE_CODE (args
[i
].tree_value
) == COND_EXPR
2692 || TREE_ADDRESSABLE (TREE_TYPE (args
[i
].tree_value
))))
2693 copy_to_evaluate_size
2694 += int_size_in_bytes (TREE_TYPE (args
[i
].tree_value
));
2697 if (maybe_ne (args_size
->constant
, 0)
2698 && maybe_ge (copy_to_evaluate_size
* 2, args_size
->constant
))
2699 must_preallocate
= 1;
2701 return must_preallocate
;
2704 /* If we preallocated stack space, compute the address of each argument
2705 and store it into the ARGS array.
2707 We need not ensure it is a valid memory address here; it will be
2708 validized when it is used.
2710 ARGBLOCK is an rtx for the address of the outgoing arguments. */
2713 compute_argument_addresses (struct arg_data
*args
, rtx argblock
, int num_actuals
)
2717 rtx arg_reg
= argblock
;
2719 poly_int64 arg_offset
= 0;
2721 if (GET_CODE (argblock
) == PLUS
)
2723 arg_reg
= XEXP (argblock
, 0);
2724 arg_offset
= rtx_to_poly_int64 (XEXP (argblock
, 1));
2727 for (i
= 0; i
< num_actuals
; i
++)
2729 rtx offset
= ARGS_SIZE_RTX (args
[i
].locate
.offset
);
2730 rtx slot_offset
= ARGS_SIZE_RTX (args
[i
].locate
.slot_offset
);
2732 unsigned int align
, boundary
;
2733 poly_uint64 units_on_stack
= 0;
2734 machine_mode partial_mode
= VOIDmode
;
2736 /* Skip this parm if it will not be passed on the stack. */
2737 if (! args
[i
].pass_on_stack
2739 && args
[i
].partial
== 0)
2742 if (TYPE_EMPTY_P (TREE_TYPE (args
[i
].tree_value
)))
2745 addr
= simplify_gen_binary (PLUS
, Pmode
, arg_reg
, offset
);
2746 addr
= plus_constant (Pmode
, addr
, arg_offset
);
2748 if (args
[i
].partial
!= 0)
2750 /* Only part of the parameter is being passed on the stack.
2751 Generate a simple memory reference of the correct size. */
2752 units_on_stack
= args
[i
].locate
.size
.constant
;
2753 poly_uint64 bits_on_stack
= units_on_stack
* BITS_PER_UNIT
;
2754 partial_mode
= int_mode_for_size (bits_on_stack
, 1).else_blk ();
2755 args
[i
].stack
= gen_rtx_MEM (partial_mode
, addr
);
2756 set_mem_size (args
[i
].stack
, units_on_stack
);
2760 args
[i
].stack
= gen_rtx_MEM (args
[i
].mode
, addr
);
2761 set_mem_attributes (args
[i
].stack
,
2762 TREE_TYPE (args
[i
].tree_value
), 1);
2764 align
= BITS_PER_UNIT
;
2765 boundary
= args
[i
].locate
.boundary
;
2766 poly_int64 offset_val
;
2767 if (args
[i
].locate
.where_pad
!= PAD_DOWNWARD
)
2769 else if (poly_int_rtx_p (offset
, &offset_val
))
2771 align
= least_bit_hwi (boundary
);
2772 unsigned int offset_align
2773 = known_alignment (offset_val
) * BITS_PER_UNIT
;
2774 if (offset_align
!= 0)
2775 align
= MIN (align
, offset_align
);
2777 set_mem_align (args
[i
].stack
, align
);
2779 addr
= simplify_gen_binary (PLUS
, Pmode
, arg_reg
, slot_offset
);
2780 addr
= plus_constant (Pmode
, addr
, arg_offset
);
2782 if (args
[i
].partial
!= 0)
2784 /* Only part of the parameter is being passed on the stack.
2785 Generate a simple memory reference of the correct size.
2787 args
[i
].stack_slot
= gen_rtx_MEM (partial_mode
, addr
);
2788 set_mem_size (args
[i
].stack_slot
, units_on_stack
);
2792 args
[i
].stack_slot
= gen_rtx_MEM (args
[i
].mode
, addr
);
2793 set_mem_attributes (args
[i
].stack_slot
,
2794 TREE_TYPE (args
[i
].tree_value
), 1);
2796 set_mem_align (args
[i
].stack_slot
, args
[i
].locate
.boundary
);
2798 /* Function incoming arguments may overlap with sibling call
2799 outgoing arguments and we cannot allow reordering of reads
2800 from function arguments with stores to outgoing arguments
2801 of sibling calls. */
2802 set_mem_alias_set (args
[i
].stack
, 0);
2803 set_mem_alias_set (args
[i
].stack_slot
, 0);
2808 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
2809 in a call instruction.
2811 FNDECL is the tree node for the target function. For an indirect call
2812 FNDECL will be NULL_TREE.
2814 ADDR is the operand 0 of CALL_EXPR for this call. */
2817 rtx_for_function_call (tree fndecl
, tree addr
)
2821 /* Get the function to call, in the form of RTL. */
2824 if (!TREE_USED (fndecl
) && fndecl
!= current_function_decl
)
2825 TREE_USED (fndecl
) = 1;
2827 /* Get a SYMBOL_REF rtx for the function address. */
2828 funexp
= XEXP (DECL_RTL (fndecl
), 0);
2831 /* Generate an rtx (probably a pseudo-register) for the address. */
2834 funexp
= expand_normal (addr
);
2835 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
2840 /* Return the static chain for this function, if any. */
2843 rtx_for_static_chain (const_tree fndecl_or_type
, bool incoming_p
)
2845 if (DECL_P (fndecl_or_type
) && !DECL_STATIC_CHAIN (fndecl_or_type
))
2848 return targetm
.calls
.static_chain (fndecl_or_type
, incoming_p
);
2851 /* Internal state for internal_arg_pointer_based_exp and its helpers. */
2854 /* Last insn that has been scanned by internal_arg_pointer_based_exp_scan,
2855 or NULL_RTX if none has been scanned yet. */
2856 rtx_insn
*scan_start
;
2857 /* Vector indexed by REGNO - FIRST_PSEUDO_REGISTER, recording if a pseudo is
2858 based on crtl->args.internal_arg_pointer. The element is NULL_RTX if the
2859 pseudo isn't based on it, a CONST_INT offset if the pseudo is based on it
2860 with fixed offset, or PC if this is with variable or unknown offset. */
2862 } internal_arg_pointer_exp_state
;
2864 static rtx
internal_arg_pointer_based_exp (const_rtx
, bool);
2866 /* Helper function for internal_arg_pointer_based_exp. Scan insns in
2867 the tail call sequence, starting with first insn that hasn't been
2868 scanned yet, and note for each pseudo on the LHS whether it is based
2869 on crtl->args.internal_arg_pointer or not, and what offset from that
2870 that pointer it has. */
2873 internal_arg_pointer_based_exp_scan (void)
2875 rtx_insn
*insn
, *scan_start
= internal_arg_pointer_exp_state
.scan_start
;
2877 if (scan_start
== NULL_RTX
)
2878 insn
= get_insns ();
2880 insn
= NEXT_INSN (scan_start
);
2884 rtx set
= single_set (insn
);
2885 if (set
&& REG_P (SET_DEST (set
)) && !HARD_REGISTER_P (SET_DEST (set
)))
2888 unsigned int idx
= REGNO (SET_DEST (set
)) - FIRST_PSEUDO_REGISTER
;
2889 /* Punt on pseudos set multiple times. */
2890 if (idx
< internal_arg_pointer_exp_state
.cache
.length ()
2891 && (internal_arg_pointer_exp_state
.cache
[idx
]
2895 val
= internal_arg_pointer_based_exp (SET_SRC (set
), false);
2896 if (val
!= NULL_RTX
)
2898 if (idx
>= internal_arg_pointer_exp_state
.cache
.length ())
2899 internal_arg_pointer_exp_state
.cache
2900 .safe_grow_cleared (idx
+ 1);
2901 internal_arg_pointer_exp_state
.cache
[idx
] = val
;
2904 if (NEXT_INSN (insn
) == NULL_RTX
)
2906 insn
= NEXT_INSN (insn
);
2909 internal_arg_pointer_exp_state
.scan_start
= scan_start
;
2912 /* Compute whether RTL is based on crtl->args.internal_arg_pointer. Return
2913 NULL_RTX if RTL isn't based on it, a CONST_INT offset if RTL is based on
2914 it with fixed offset, or PC if this is with variable or unknown offset.
2915 TOPLEVEL is true if the function is invoked at the topmost level. */
2918 internal_arg_pointer_based_exp (const_rtx rtl
, bool toplevel
)
2920 if (CONSTANT_P (rtl
))
2923 if (rtl
== crtl
->args
.internal_arg_pointer
)
2926 if (REG_P (rtl
) && HARD_REGISTER_P (rtl
))
2930 if (GET_CODE (rtl
) == PLUS
&& poly_int_rtx_p (XEXP (rtl
, 1), &offset
))
2932 rtx val
= internal_arg_pointer_based_exp (XEXP (rtl
, 0), toplevel
);
2933 if (val
== NULL_RTX
|| val
== pc_rtx
)
2935 return plus_constant (Pmode
, val
, offset
);
2938 /* When called at the topmost level, scan pseudo assignments in between the
2939 last scanned instruction in the tail call sequence and the latest insn
2940 in that sequence. */
2942 internal_arg_pointer_based_exp_scan ();
2946 unsigned int idx
= REGNO (rtl
) - FIRST_PSEUDO_REGISTER
;
2947 if (idx
< internal_arg_pointer_exp_state
.cache
.length ())
2948 return internal_arg_pointer_exp_state
.cache
[idx
];
2953 subrtx_iterator::array_type array
;
2954 FOR_EACH_SUBRTX (iter
, array
, rtl
, NONCONST
)
2956 const_rtx x
= *iter
;
2957 if (REG_P (x
) && internal_arg_pointer_based_exp (x
, false) != NULL_RTX
)
2960 iter
.skip_subrtxes ();
2966 /* Return true if SIZE bytes starting from address ADDR might overlap an
2967 already-clobbered argument area. This function is used to determine
2968 if we should give up a sibcall. */
2971 mem_might_overlap_already_clobbered_arg_p (rtx addr
, poly_uint64 size
)
2974 unsigned HOST_WIDE_INT start
, end
;
2977 if (bitmap_empty_p (stored_args_map
)
2978 && stored_args_watermark
== HOST_WIDE_INT_M1U
)
2980 val
= internal_arg_pointer_based_exp (addr
, true);
2981 if (val
== NULL_RTX
)
2983 else if (!poly_int_rtx_p (val
, &i
))
2986 if (known_eq (size
, 0U))
2989 if (STACK_GROWS_DOWNWARD
)
2990 i
-= crtl
->args
.pretend_args_size
;
2992 i
+= crtl
->args
.pretend_args_size
;
2994 if (ARGS_GROW_DOWNWARD
)
2997 /* We can ignore any references to the function's pretend args,
2998 which at this point would manifest as negative values of I. */
2999 if (known_le (i
, 0) && known_le (size
, poly_uint64 (-i
)))
3002 start
= maybe_lt (i
, 0) ? 0 : constant_lower_bound (i
);
3003 if (!(i
+ size
).is_constant (&end
))
3004 end
= HOST_WIDE_INT_M1U
;
3006 if (end
> stored_args_watermark
)
3009 end
= MIN (end
, SBITMAP_SIZE (stored_args_map
));
3010 for (unsigned HOST_WIDE_INT k
= start
; k
< end
; ++k
)
3011 if (bitmap_bit_p (stored_args_map
, k
))
3017 /* Do the register loads required for any wholly-register parms or any
3018 parms which are passed both on the stack and in a register. Their
3019 expressions were already evaluated.
3021 Mark all register-parms as living through the call, putting these USE
3022 insns in the CALL_INSN_FUNCTION_USAGE field.
3024 When IS_SIBCALL, perform the check_sibcall_argument_overlap
3025 checking, setting *SIBCALL_FAILURE if appropriate. */
3028 load_register_parameters (struct arg_data
*args
, int num_actuals
,
3029 rtx
*call_fusage
, int flags
, int is_sibcall
,
3030 int *sibcall_failure
)
3034 for (i
= 0; i
< num_actuals
; i
++)
3036 rtx reg
= ((flags
& ECF_SIBCALL
)
3037 ? args
[i
].tail_call_reg
: args
[i
].reg
);
3040 int partial
= args
[i
].partial
;
3042 poly_int64 size
= 0;
3043 HOST_WIDE_INT const_size
= 0;
3044 rtx_insn
*before_arg
= get_last_insn ();
3045 tree type
= TREE_TYPE (args
[i
].tree_value
);
3046 if (RECORD_OR_UNION_TYPE_P (type
) && TYPE_TRANSPARENT_AGGR (type
))
3047 type
= TREE_TYPE (first_field (type
));
3048 /* Set non-negative if we must move a word at a time, even if
3049 just one word (e.g, partial == 4 && mode == DFmode). Set
3050 to -1 if we just use a normal move insn. This value can be
3051 zero if the argument is a zero size structure. */
3053 if (GET_CODE (reg
) == PARALLEL
)
3057 gcc_assert (partial
% UNITS_PER_WORD
== 0);
3058 nregs
= partial
/ UNITS_PER_WORD
;
3060 else if (TYPE_MODE (type
) == BLKmode
)
3062 /* Variable-sized parameters should be described by a
3063 PARALLEL instead. */
3064 const_size
= int_size_in_bytes (type
);
3065 gcc_assert (const_size
>= 0);
3066 nregs
= (const_size
+ (UNITS_PER_WORD
- 1)) / UNITS_PER_WORD
;
3070 size
= GET_MODE_SIZE (args
[i
].mode
);
3072 /* Handle calls that pass values in multiple non-contiguous
3073 locations. The Irix 6 ABI has examples of this. */
3075 if (GET_CODE (reg
) == PARALLEL
)
3076 emit_group_move (reg
, args
[i
].parallel_value
);
3078 /* If simple case, just do move. If normal partial, store_one_arg
3079 has already loaded the register for us. In all other cases,
3080 load the register(s) from memory. */
3082 else if (nregs
== -1)
3084 emit_move_insn (reg
, args
[i
].value
);
3085 #ifdef BLOCK_REG_PADDING
3086 /* Handle case where we have a value that needs shifting
3087 up to the msb. eg. a QImode value and we're padding
3088 upward on a BYTES_BIG_ENDIAN machine. */
3089 if (args
[i
].locate
.where_pad
3090 == (BYTES_BIG_ENDIAN
? PAD_UPWARD
: PAD_DOWNWARD
))
3092 gcc_checking_assert (ordered_p (size
, UNITS_PER_WORD
));
3093 if (maybe_lt (size
, UNITS_PER_WORD
))
3097 = (UNITS_PER_WORD
- size
) * BITS_PER_UNIT
;
3099 /* Assigning REG here rather than a temp makes
3100 CALL_FUSAGE report the whole reg as used.
3101 Strictly speaking, the call only uses SIZE
3102 bytes at the msb end, but it doesn't seem worth
3103 generating rtl to say that. */
3104 reg
= gen_rtx_REG (word_mode
, REGNO (reg
));
3105 x
= expand_shift (LSHIFT_EXPR
, word_mode
,
3106 reg
, shift
, reg
, 1);
3108 emit_move_insn (reg
, x
);
3114 /* If we have pre-computed the values to put in the registers in
3115 the case of non-aligned structures, copy them in now. */
3117 else if (args
[i
].n_aligned_regs
!= 0)
3118 for (j
= 0; j
< args
[i
].n_aligned_regs
; j
++)
3119 emit_move_insn (gen_rtx_REG (word_mode
, REGNO (reg
) + j
),
3120 args
[i
].aligned_regs
[j
]);
3122 else if (partial
== 0 || args
[i
].pass_on_stack
)
3124 /* SIZE and CONST_SIZE are 0 for partial arguments and
3125 the size of a BLKmode type otherwise. */
3126 gcc_checking_assert (known_eq (size
, const_size
));
3127 rtx mem
= validize_mem (copy_rtx (args
[i
].value
));
3129 /* Check for overlap with already clobbered argument area,
3130 providing that this has non-zero size. */
3133 && (mem_might_overlap_already_clobbered_arg_p
3134 (XEXP (args
[i
].value
, 0), const_size
)))
3135 *sibcall_failure
= 1;
3137 if (const_size
% UNITS_PER_WORD
== 0
3138 || MEM_ALIGN (mem
) % BITS_PER_WORD
== 0)
3139 move_block_to_reg (REGNO (reg
), mem
, nregs
, args
[i
].mode
);
3143 move_block_to_reg (REGNO (reg
), mem
, nregs
- 1,
3145 rtx dest
= gen_rtx_REG (word_mode
, REGNO (reg
) + nregs
- 1);
3146 unsigned int bitoff
= (nregs
- 1) * BITS_PER_WORD
;
3147 unsigned int bitsize
= const_size
* BITS_PER_UNIT
- bitoff
;
3148 rtx x
= extract_bit_field (mem
, bitsize
, bitoff
, 1, dest
,
3149 word_mode
, word_mode
, false,
3151 if (BYTES_BIG_ENDIAN
)
3152 x
= expand_shift (LSHIFT_EXPR
, word_mode
, x
,
3153 BITS_PER_WORD
- bitsize
, dest
, 1);
3155 emit_move_insn (dest
, x
);
3158 /* Handle a BLKmode that needs shifting. */
3159 if (nregs
== 1 && const_size
< UNITS_PER_WORD
3160 #ifdef BLOCK_REG_PADDING
3161 && args
[i
].locate
.where_pad
== PAD_DOWNWARD
3167 rtx dest
= gen_rtx_REG (word_mode
, REGNO (reg
));
3168 int shift
= (UNITS_PER_WORD
- const_size
) * BITS_PER_UNIT
;
3169 enum tree_code dir
= (BYTES_BIG_ENDIAN
3170 ? RSHIFT_EXPR
: LSHIFT_EXPR
);
3173 x
= expand_shift (dir
, word_mode
, dest
, shift
, dest
, 1);
3175 emit_move_insn (dest
, x
);
3179 /* When a parameter is a block, and perhaps in other cases, it is
3180 possible that it did a load from an argument slot that was
3181 already clobbered. */
3183 && check_sibcall_argument_overlap (before_arg
, &args
[i
], 0))
3184 *sibcall_failure
= 1;
3186 /* Handle calls that pass values in multiple non-contiguous
3187 locations. The Irix 6 ABI has examples of this. */
3188 if (GET_CODE (reg
) == PARALLEL
)
3189 use_group_regs (call_fusage
, reg
);
3190 else if (nregs
== -1)
3191 use_reg_mode (call_fusage
, reg
, TYPE_MODE (type
));
3193 use_regs (call_fusage
, REGNO (reg
), nregs
);
3198 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
3199 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
3200 bytes, then we would need to push some additional bytes to pad the
3201 arguments. So, we try to compute an adjust to the stack pointer for an
3202 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
3203 bytes. Then, when the arguments are pushed the stack will be perfectly
3206 Return true if this optimization is possible, storing the adjustment
3207 in ADJUSTMENT_OUT and setting ARGS_SIZE->CONSTANT to the number of
3208 bytes that should be popped after the call. */
3211 combine_pending_stack_adjustment_and_call (poly_int64_pod
*adjustment_out
,
3212 poly_int64 unadjusted_args_size
,
3213 struct args_size
*args_size
,
3214 unsigned int preferred_unit_stack_boundary
)
3216 /* The number of bytes to pop so that the stack will be
3217 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
3218 poly_int64 adjustment
;
3219 /* The alignment of the stack after the arguments are pushed, if we
3220 just pushed the arguments without adjust the stack here. */
3221 unsigned HOST_WIDE_INT unadjusted_alignment
;
3223 if (!known_misalignment (stack_pointer_delta
+ unadjusted_args_size
,
3224 preferred_unit_stack_boundary
,
3225 &unadjusted_alignment
))
3228 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
3229 as possible -- leaving just enough left to cancel out the
3230 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
3231 PENDING_STACK_ADJUST is non-negative, and congruent to
3232 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
3234 /* Begin by trying to pop all the bytes. */
3235 unsigned HOST_WIDE_INT tmp_misalignment
;
3236 if (!known_misalignment (pending_stack_adjust
,
3237 preferred_unit_stack_boundary
,
3240 unadjusted_alignment
-= tmp_misalignment
;
3241 adjustment
= pending_stack_adjust
;
3242 /* Push enough additional bytes that the stack will be aligned
3243 after the arguments are pushed. */
3244 if (preferred_unit_stack_boundary
> 1 && unadjusted_alignment
)
3245 adjustment
-= preferred_unit_stack_boundary
- unadjusted_alignment
;
3247 /* We need to know whether the adjusted argument size
3248 (UNADJUSTED_ARGS_SIZE - ADJUSTMENT) constitutes an allocation
3249 or a deallocation. */
3250 if (!ordered_p (adjustment
, unadjusted_args_size
))
3253 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
3254 bytes after the call. The right number is the entire
3255 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
3256 by the arguments in the first place. */
3258 = pending_stack_adjust
- adjustment
+ unadjusted_args_size
;
3260 *adjustment_out
= adjustment
;
3264 /* Scan X expression if it does not dereference any argument slots
3265 we already clobbered by tail call arguments (as noted in stored_args_map
3267 Return nonzero if X expression dereferences such argument slots,
3271 check_sibcall_argument_overlap_1 (rtx x
)
3280 code
= GET_CODE (x
);
3282 /* We need not check the operands of the CALL expression itself. */
3287 return (mem_might_overlap_already_clobbered_arg_p
3288 (XEXP (x
, 0), GET_MODE_SIZE (GET_MODE (x
))));
3290 /* Scan all subexpressions. */
3291 fmt
= GET_RTX_FORMAT (code
);
3292 for (i
= 0; i
< GET_RTX_LENGTH (code
); i
++, fmt
++)
3296 if (check_sibcall_argument_overlap_1 (XEXP (x
, i
)))
3299 else if (*fmt
== 'E')
3301 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
3302 if (check_sibcall_argument_overlap_1 (XVECEXP (x
, i
, j
)))
3309 /* Scan sequence after INSN if it does not dereference any argument slots
3310 we already clobbered by tail call arguments (as noted in stored_args_map
3311 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
3312 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
3313 should be 0). Return nonzero if sequence after INSN dereferences such argument
3314 slots, zero otherwise. */
3317 check_sibcall_argument_overlap (rtx_insn
*insn
, struct arg_data
*arg
,
3318 int mark_stored_args_map
)
3320 poly_uint64 low
, high
;
3321 unsigned HOST_WIDE_INT const_low
, const_high
;
3323 if (insn
== NULL_RTX
)
3324 insn
= get_insns ();
3326 insn
= NEXT_INSN (insn
);
3328 for (; insn
; insn
= NEXT_INSN (insn
))
3330 && check_sibcall_argument_overlap_1 (PATTERN (insn
)))
3333 if (mark_stored_args_map
)
3335 if (ARGS_GROW_DOWNWARD
)
3336 low
= -arg
->locate
.slot_offset
.constant
- arg
->locate
.size
.constant
;
3338 low
= arg
->locate
.slot_offset
.constant
;
3339 high
= low
+ arg
->locate
.size
.constant
;
3341 const_low
= constant_lower_bound (low
);
3342 if (high
.is_constant (&const_high
))
3343 for (unsigned HOST_WIDE_INT i
= const_low
; i
< const_high
; ++i
)
3344 bitmap_set_bit (stored_args_map
, i
);
3346 stored_args_watermark
= MIN (stored_args_watermark
, const_low
);
3348 return insn
!= NULL_RTX
;
3351 /* Given that a function returns a value of mode MODE at the most
3352 significant end of hard register VALUE, shift VALUE left or right
3353 as specified by LEFT_P. Return true if some action was needed. */
3356 shift_return_value (machine_mode mode
, bool left_p
, rtx value
)
3358 gcc_assert (REG_P (value
) && HARD_REGISTER_P (value
));
3359 machine_mode value_mode
= GET_MODE (value
);
3360 poly_int64 shift
= GET_MODE_BITSIZE (value_mode
) - GET_MODE_BITSIZE (mode
);
3362 if (known_eq (shift
, 0))
3365 /* Use ashr rather than lshr for right shifts. This is for the benefit
3366 of the MIPS port, which requires SImode values to be sign-extended
3367 when stored in 64-bit registers. */
3368 if (!force_expand_binop (value_mode
, left_p
? ashl_optab
: ashr_optab
,
3369 value
, gen_int_shift_amount (value_mode
, shift
),
3370 value
, 1, OPTAB_WIDEN
))
3375 /* If X is a likely-spilled register value, copy it to a pseudo
3376 register and return that register. Return X otherwise. */
3379 avoid_likely_spilled_reg (rtx x
)
3384 && HARD_REGISTER_P (x
)
3385 && targetm
.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (x
))))
3387 /* Make sure that we generate a REG rather than a CONCAT.
3388 Moves into CONCATs can need nontrivial instructions,
3389 and the whole point of this function is to avoid
3390 using the hard register directly in such a situation. */
3391 generating_concat_p
= 0;
3392 new_rtx
= gen_reg_rtx (GET_MODE (x
));
3393 generating_concat_p
= 1;
3394 emit_move_insn (new_rtx
, x
);
3400 /* Helper function for expand_call.
3401 Return false is EXP is not implementable as a sibling call. */
3404 can_implement_as_sibling_call_p (tree exp
,
3405 rtx structure_value_addr
,
3407 int reg_parm_stack_space ATTRIBUTE_UNUSED
,
3411 const args_size
&args_size
)
3413 if (!targetm
.have_sibcall_epilogue ())
3415 maybe_complain_about_tail_call
3417 "machine description does not have"
3418 " a sibcall_epilogue instruction pattern");
3422 /* Doing sibling call optimization needs some work, since
3423 structure_value_addr can be allocated on the stack.
3424 It does not seem worth the effort since few optimizable
3425 sibling calls will return a structure. */
3426 if (structure_value_addr
!= NULL_RTX
)
3428 maybe_complain_about_tail_call (exp
, "callee returns a structure");
3432 #ifdef REG_PARM_STACK_SPACE
3433 /* If outgoing reg parm stack space changes, we cannot do sibcall. */
3434 if (OUTGOING_REG_PARM_STACK_SPACE (funtype
)
3435 != OUTGOING_REG_PARM_STACK_SPACE (TREE_TYPE (current_function_decl
))
3436 || (reg_parm_stack_space
!= REG_PARM_STACK_SPACE (current_function_decl
)))
3438 maybe_complain_about_tail_call (exp
,
3439 "inconsistent size of stack space"
3440 " allocated for arguments which are"
3441 " passed in registers");
3446 /* Check whether the target is able to optimize the call
3448 if (!targetm
.function_ok_for_sibcall (fndecl
, exp
))
3450 maybe_complain_about_tail_call (exp
,
3451 "target is not able to optimize the"
3452 " call into a sibling call");
3456 /* Functions that do not return exactly once may not be sibcall
3458 if (flags
& ECF_RETURNS_TWICE
)
3460 maybe_complain_about_tail_call (exp
, "callee returns twice");
3463 if (flags
& ECF_NORETURN
)
3465 maybe_complain_about_tail_call (exp
, "callee does not return");
3469 if (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr
))))
3471 maybe_complain_about_tail_call (exp
, "volatile function type");
3475 /* If the called function is nested in the current one, it might access
3476 some of the caller's arguments, but could clobber them beforehand if
3477 the argument areas are shared. */
3478 if (fndecl
&& decl_function_context (fndecl
) == current_function_decl
)
3480 maybe_complain_about_tail_call (exp
, "nested function");
3484 /* If this function requires more stack slots than the current
3485 function, we cannot change it into a sibling call.
3486 crtl->args.pretend_args_size is not part of the
3487 stack allocated by our caller. */
3488 if (maybe_gt (args_size
.constant
,
3489 crtl
->args
.size
- crtl
->args
.pretend_args_size
))
3491 maybe_complain_about_tail_call (exp
,
3492 "callee required more stack slots"
3493 " than the caller");
3497 /* If the callee pops its own arguments, then it must pop exactly
3498 the same number of arguments as the current function. */
3499 if (maybe_ne (targetm
.calls
.return_pops_args (fndecl
, funtype
,
3500 args_size
.constant
),
3501 targetm
.calls
.return_pops_args (current_function_decl
,
3503 (current_function_decl
),
3506 maybe_complain_about_tail_call (exp
,
3507 "inconsistent number of"
3508 " popped arguments");
3512 if (!lang_hooks
.decls
.ok_for_sibcall (fndecl
))
3514 maybe_complain_about_tail_call (exp
, "frontend does not support"
3519 /* All checks passed. */
3523 /* Update stack alignment when the parameter is passed in the stack
3524 since the outgoing parameter requires extra alignment on the calling
3528 update_stack_alignment_for_call (struct locate_and_pad_arg_data
*locate
)
3530 if (crtl
->stack_alignment_needed
< locate
->boundary
)
3531 crtl
->stack_alignment_needed
= locate
->boundary
;
3532 if (crtl
->preferred_stack_boundary
< locate
->boundary
)
3533 crtl
->preferred_stack_boundary
= locate
->boundary
;
3536 /* Generate all the code for a CALL_EXPR exp
3537 and return an rtx for its value.
3538 Store the value in TARGET (specified as an rtx) if convenient.
3539 If the value is stored in TARGET then TARGET is returned.
3540 If IGNORE is nonzero, then we ignore the value of the function call. */
3543 expand_call (tree exp
, rtx target
, int ignore
)
3545 /* Nonzero if we are currently expanding a call. */
3546 static int currently_expanding_call
= 0;
3548 /* RTX for the function to be called. */
3550 /* Sequence of insns to perform a normal "call". */
3551 rtx_insn
*normal_call_insns
= NULL
;
3552 /* Sequence of insns to perform a tail "call". */
3553 rtx_insn
*tail_call_insns
= NULL
;
3554 /* Data type of the function. */
3556 tree type_arg_types
;
3558 /* Declaration of the function being called,
3559 or 0 if the function is computed (not known by name). */
3561 /* The type of the function being called. */
3563 bool try_tail_call
= CALL_EXPR_TAILCALL (exp
);
3564 bool must_tail_call
= CALL_EXPR_MUST_TAIL_CALL (exp
);
3567 /* Register in which non-BLKmode value will be returned,
3568 or 0 if no value or if value is BLKmode. */
3570 /* Address where we should return a BLKmode value;
3571 0 if value not BLKmode. */
3572 rtx structure_value_addr
= 0;
3573 /* Nonzero if that address is being passed by treating it as
3574 an extra, implicit first parameter. Otherwise,
3575 it is passed by being copied directly into struct_value_rtx. */
3576 int structure_value_addr_parm
= 0;
3577 /* Holds the value of implicit argument for the struct value. */
3578 tree structure_value_addr_value
= NULL_TREE
;
3579 /* Size of aggregate value wanted, or zero if none wanted
3580 or if we are using the non-reentrant PCC calling convention
3581 or expecting the value in registers. */
3582 poly_int64 struct_value_size
= 0;
3583 /* Nonzero if called function returns an aggregate in memory PCC style,
3584 by returning the address of where to find it. */
3585 int pcc_struct_value
= 0;
3586 rtx struct_value
= 0;
3588 /* Number of actual parameters in this call, including struct value addr. */
3590 /* Number of named args. Args after this are anonymous ones
3591 and they must all go on the stack. */
3593 /* Number of complex actual arguments that need to be split. */
3594 int num_complex_actuals
= 0;
3596 /* Vector of information about each argument.
3597 Arguments are numbered in the order they will be pushed,
3598 not the order they are written. */
3599 struct arg_data
*args
;
3601 /* Total size in bytes of all the stack-parms scanned so far. */
3602 struct args_size args_size
;
3603 struct args_size adjusted_args_size
;
3604 /* Size of arguments before any adjustments (such as rounding). */
3605 poly_int64 unadjusted_args_size
;
3606 /* Data on reg parms scanned so far. */
3607 CUMULATIVE_ARGS args_so_far_v
;
3608 cumulative_args_t args_so_far
;
3609 /* Nonzero if a reg parm has been scanned. */
3611 /* Nonzero if this is an indirect function call. */
3613 /* Nonzero if we must avoid push-insns in the args for this call.
3614 If stack space is allocated for register parameters, but not by the
3615 caller, then it is preallocated in the fixed part of the stack frame.
3616 So the entire argument block must then be preallocated (i.e., we
3617 ignore PUSH_ROUNDING in that case). */
3619 int must_preallocate
= !PUSH_ARGS
;
3621 /* Size of the stack reserved for parameter registers. */
3622 int reg_parm_stack_space
= 0;
3624 /* Address of space preallocated for stack parms
3625 (on machines that lack push insns), or 0 if space not preallocated. */
3628 /* Mask of ECF_ and ERF_ flags. */
3630 int return_flags
= 0;
3631 #ifdef REG_PARM_STACK_SPACE
3632 /* Define the boundary of the register parm stack space that needs to be
3634 int low_to_save
, high_to_save
;
3635 rtx save_area
= 0; /* Place that it is saved */
3638 unsigned int initial_highest_arg_in_use
= highest_outgoing_arg_in_use
;
3639 char *initial_stack_usage_map
= stack_usage_map
;
3640 unsigned HOST_WIDE_INT initial_stack_usage_watermark
= stack_usage_watermark
;
3641 char *stack_usage_map_buf
= NULL
;
3643 poly_int64 old_stack_allocated
;
3645 /* State variables to track stack modifications. */
3646 rtx old_stack_level
= 0;
3647 int old_stack_arg_under_construction
= 0;
3648 poly_int64 old_pending_adj
= 0;
3649 int old_inhibit_defer_pop
= inhibit_defer_pop
;
3651 /* Some stack pointer alterations we make are performed via
3652 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
3653 which we then also need to save/restore along the way. */
3654 poly_int64 old_stack_pointer_delta
= 0;
3657 tree addr
= CALL_EXPR_FN (exp
);
3659 /* The alignment of the stack, in bits. */
3660 unsigned HOST_WIDE_INT preferred_stack_boundary
;
3661 /* The alignment of the stack, in bytes. */
3662 unsigned HOST_WIDE_INT preferred_unit_stack_boundary
;
3663 /* The static chain value to use for this call. */
3664 rtx static_chain_value
;
3665 /* See if this is "nothrow" function call. */
3666 if (TREE_NOTHROW (exp
))
3667 flags
|= ECF_NOTHROW
;
3669 /* See if we can find a DECL-node for the actual function, and get the
3670 function attributes (flags) from the function decl or type node. */
3671 fndecl
= get_callee_fndecl (exp
);
3674 fntype
= TREE_TYPE (fndecl
);
3675 flags
|= flags_from_decl_or_type (fndecl
);
3676 return_flags
|= decl_return_flags (fndecl
);
3680 fntype
= TREE_TYPE (TREE_TYPE (addr
));
3681 flags
|= flags_from_decl_or_type (fntype
);
3682 if (CALL_EXPR_BY_DESCRIPTOR (exp
))
3683 flags
|= ECF_BY_DESCRIPTOR
;
3685 rettype
= TREE_TYPE (exp
);
3687 struct_value
= targetm
.calls
.struct_value_rtx (fntype
, 0);
3689 /* Warn if this value is an aggregate type,
3690 regardless of which calling convention we are using for it. */
3691 if (AGGREGATE_TYPE_P (rettype
))
3692 warning (OPT_Waggregate_return
, "function call has aggregate value");
3694 /* If the result of a non looping pure or const function call is
3695 ignored (or void), and none of its arguments are volatile, we can
3696 avoid expanding the call and just evaluate the arguments for
3698 if ((flags
& (ECF_CONST
| ECF_PURE
))
3699 && (!(flags
& ECF_LOOPING_CONST_OR_PURE
))
3700 && (ignore
|| target
== const0_rtx
3701 || TYPE_MODE (rettype
) == VOIDmode
))
3703 bool volatilep
= false;
3705 call_expr_arg_iterator iter
;
3707 FOR_EACH_CALL_EXPR_ARG (arg
, iter
, exp
)
3708 if (TREE_THIS_VOLATILE (arg
))
3716 FOR_EACH_CALL_EXPR_ARG (arg
, iter
, exp
)
3717 expand_expr (arg
, const0_rtx
, VOIDmode
, EXPAND_NORMAL
);
3722 #ifdef REG_PARM_STACK_SPACE
3723 reg_parm_stack_space
= REG_PARM_STACK_SPACE (!fndecl
? fntype
: fndecl
);
3726 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl
? fntype
: TREE_TYPE (fndecl
)))
3727 && reg_parm_stack_space
> 0 && PUSH_ARGS
)
3728 must_preallocate
= 1;
3730 /* Set up a place to return a structure. */
3732 /* Cater to broken compilers. */
3733 if (aggregate_value_p (exp
, fntype
))
3735 /* This call returns a big structure. */
3736 flags
&= ~(ECF_CONST
| ECF_PURE
| ECF_LOOPING_CONST_OR_PURE
);
3738 #ifdef PCC_STATIC_STRUCT_RETURN
3740 pcc_struct_value
= 1;
3742 #else /* not PCC_STATIC_STRUCT_RETURN */
3744 if (!poly_int_tree_p (TYPE_SIZE_UNIT (rettype
), &struct_value_size
))
3745 struct_value_size
= -1;
3747 /* Even if it is semantically safe to use the target as the return
3748 slot, it may be not sufficiently aligned for the return type. */
3749 if (CALL_EXPR_RETURN_SLOT_OPT (exp
)
3752 /* If rettype is addressable, we may not create a temporary.
3753 If target is properly aligned at runtime and the compiler
3754 just doesn't know about it, it will work fine, otherwise it
3756 && (TREE_ADDRESSABLE (rettype
)
3757 || !(MEM_ALIGN (target
) < TYPE_ALIGN (rettype
)
3758 && targetm
.slow_unaligned_access (TYPE_MODE (rettype
),
3759 MEM_ALIGN (target
)))))
3760 structure_value_addr
= XEXP (target
, 0);
3763 /* For variable-sized objects, we must be called with a target
3764 specified. If we were to allocate space on the stack here,
3765 we would have no way of knowing when to free it. */
3766 rtx d
= assign_temp (rettype
, 1, 1);
3767 structure_value_addr
= XEXP (d
, 0);
3771 #endif /* not PCC_STATIC_STRUCT_RETURN */
3774 /* Figure out the amount to which the stack should be aligned. */
3775 preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
3778 struct cgraph_rtl_info
*i
= cgraph_node::rtl_info (fndecl
);
3779 /* Without automatic stack alignment, we can't increase preferred
3780 stack boundary. With automatic stack alignment, it is
3781 unnecessary since unless we can guarantee that all callers will
3782 align the outgoing stack properly, callee has to align its
3785 && i
->preferred_incoming_stack_boundary
3786 && i
->preferred_incoming_stack_boundary
< preferred_stack_boundary
)
3787 preferred_stack_boundary
= i
->preferred_incoming_stack_boundary
;
3790 /* Operand 0 is a pointer-to-function; get the type of the function. */
3791 funtype
= TREE_TYPE (addr
);
3792 gcc_assert (POINTER_TYPE_P (funtype
));
3793 funtype
= TREE_TYPE (funtype
);
3795 /* Count whether there are actual complex arguments that need to be split
3796 into their real and imaginary parts. Munge the type_arg_types
3797 appropriately here as well. */
3798 if (targetm
.calls
.split_complex_arg
)
3800 call_expr_arg_iterator iter
;
3802 FOR_EACH_CALL_EXPR_ARG (arg
, iter
, exp
)
3804 tree type
= TREE_TYPE (arg
);
3805 if (type
&& TREE_CODE (type
) == COMPLEX_TYPE
3806 && targetm
.calls
.split_complex_arg (type
))
3807 num_complex_actuals
++;
3809 type_arg_types
= split_complex_types (TYPE_ARG_TYPES (funtype
));
3812 type_arg_types
= TYPE_ARG_TYPES (funtype
);
3814 if (flags
& ECF_MAY_BE_ALLOCA
)
3815 cfun
->calls_alloca
= 1;
3817 /* If struct_value_rtx is 0, it means pass the address
3818 as if it were an extra parameter. Put the argument expression
3819 in structure_value_addr_value. */
3820 if (structure_value_addr
&& struct_value
== 0)
3822 /* If structure_value_addr is a REG other than
3823 virtual_outgoing_args_rtx, we can use always use it. If it
3824 is not a REG, we must always copy it into a register.
3825 If it is virtual_outgoing_args_rtx, we must copy it to another
3826 register in some cases. */
3827 rtx temp
= (!REG_P (structure_value_addr
)
3828 || (ACCUMULATE_OUTGOING_ARGS
3829 && stack_arg_under_construction
3830 && structure_value_addr
== virtual_outgoing_args_rtx
)
3831 ? copy_addr_to_reg (convert_memory_address
3832 (Pmode
, structure_value_addr
))
3833 : structure_value_addr
);
3835 structure_value_addr_value
=
3836 make_tree (build_pointer_type (TREE_TYPE (funtype
)), temp
);
3837 structure_value_addr_parm
= 1;
3840 /* Count the arguments and set NUM_ACTUALS. */
3842 call_expr_nargs (exp
) + num_complex_actuals
+ structure_value_addr_parm
;
3844 /* Compute number of named args.
3845 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
3847 if (type_arg_types
!= 0)
3849 = (list_length (type_arg_types
)
3850 /* Count the struct value address, if it is passed as a parm. */
3851 + structure_value_addr_parm
);
3853 /* If we know nothing, treat all args as named. */
3854 n_named_args
= num_actuals
;
3856 /* Start updating where the next arg would go.
3858 On some machines (such as the PA) indirect calls have a different
3859 calling convention than normal calls. The fourth argument in
3860 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
3862 INIT_CUMULATIVE_ARGS (args_so_far_v
, funtype
, NULL_RTX
, fndecl
, n_named_args
);
3863 args_so_far
= pack_cumulative_args (&args_so_far_v
);
3865 /* Now possibly adjust the number of named args.
3866 Normally, don't include the last named arg if anonymous args follow.
3867 We do include the last named arg if
3868 targetm.calls.strict_argument_naming() returns nonzero.
3869 (If no anonymous args follow, the result of list_length is actually
3870 one too large. This is harmless.)
3872 If targetm.calls.pretend_outgoing_varargs_named() returns
3873 nonzero, and targetm.calls.strict_argument_naming() returns zero,
3874 this machine will be able to place unnamed args that were passed
3875 in registers into the stack. So treat all args as named. This
3876 allows the insns emitting for a specific argument list to be
3877 independent of the function declaration.
3879 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
3880 we do not have any reliable way to pass unnamed args in
3881 registers, so we must force them into memory. */
3883 if (type_arg_types
!= 0
3884 && targetm
.calls
.strict_argument_naming (args_so_far
))
3886 else if (type_arg_types
!= 0
3887 && ! targetm
.calls
.pretend_outgoing_varargs_named (args_so_far
))
3888 /* Don't include the last named arg. */
3891 /* Treat all args as named. */
3892 n_named_args
= num_actuals
;
3894 /* Make a vector to hold all the information about each arg. */
3895 args
= XCNEWVEC (struct arg_data
, num_actuals
);
3897 /* Build up entries in the ARGS array, compute the size of the
3898 arguments into ARGS_SIZE, etc. */
3899 initialize_argument_information (num_actuals
, args
, &args_size
,
3901 structure_value_addr_value
, fndecl
, fntype
,
3902 args_so_far
, reg_parm_stack_space
,
3903 &old_stack_level
, &old_pending_adj
,
3904 &must_preallocate
, &flags
,
3905 &try_tail_call
, CALL_FROM_THUNK_P (exp
));
3908 must_preallocate
= 1;
3910 /* Now make final decision about preallocating stack space. */
3911 must_preallocate
= finalize_must_preallocate (must_preallocate
,
3915 /* If the structure value address will reference the stack pointer, we
3916 must stabilize it. We don't need to do this if we know that we are
3917 not going to adjust the stack pointer in processing this call. */
3919 if (structure_value_addr
3920 && (reg_mentioned_p (virtual_stack_dynamic_rtx
, structure_value_addr
)
3921 || reg_mentioned_p (virtual_outgoing_args_rtx
,
3922 structure_value_addr
))
3924 || (!ACCUMULATE_OUTGOING_ARGS
3925 && maybe_ne (args_size
.constant
, 0))))
3926 structure_value_addr
= copy_to_reg (structure_value_addr
);
3928 /* Tail calls can make things harder to debug, and we've traditionally
3929 pushed these optimizations into -O2. Don't try if we're already
3930 expanding a call, as that means we're an argument. Don't try if
3931 there's cleanups, as we know there's code to follow the call. */
3932 if (currently_expanding_call
++ != 0
3933 || (!flag_optimize_sibling_calls
&& !CALL_FROM_THUNK_P (exp
))
3935 || dbg_cnt (tail_call
) == false)
3938 /* Workaround buggy C/C++ wrappers around Fortran routines with
3939 character(len=constant) arguments if the hidden string length arguments
3940 are passed on the stack; if the callers forget to pass those arguments,
3941 attempting to tail call in such routines leads to stack corruption.
3942 Avoid tail calls in functions where at least one such hidden string
3943 length argument is passed (partially or fully) on the stack in the
3944 caller and the callee needs to pass any arguments on the stack.
3946 if (try_tail_call
&& maybe_ne (args_size
.constant
, 0))
3947 for (tree arg
= DECL_ARGUMENTS (current_function_decl
);
3948 arg
; arg
= DECL_CHAIN (arg
))
3949 if (DECL_HIDDEN_STRING_LENGTH (arg
) && DECL_INCOMING_RTL (arg
))
3951 subrtx_iterator::array_type array
;
3952 FOR_EACH_SUBRTX (iter
, array
, DECL_INCOMING_RTL (arg
), NONCONST
)
3960 /* If the user has marked the function as requiring tail-call
3961 optimization, attempt it. */
3965 /* Rest of purposes for tail call optimizations to fail. */
3967 try_tail_call
= can_implement_as_sibling_call_p (exp
,
3968 structure_value_addr
,
3970 reg_parm_stack_space
,
3972 flags
, addr
, args_size
);
3974 /* Check if caller and callee disagree in promotion of function
3978 machine_mode caller_mode
, caller_promoted_mode
;
3979 machine_mode callee_mode
, callee_promoted_mode
;
3980 int caller_unsignedp
, callee_unsignedp
;
3981 tree caller_res
= DECL_RESULT (current_function_decl
);
3983 caller_unsignedp
= TYPE_UNSIGNED (TREE_TYPE (caller_res
));
3984 caller_mode
= DECL_MODE (caller_res
);
3985 callee_unsignedp
= TYPE_UNSIGNED (TREE_TYPE (funtype
));
3986 callee_mode
= TYPE_MODE (TREE_TYPE (funtype
));
3987 caller_promoted_mode
3988 = promote_function_mode (TREE_TYPE (caller_res
), caller_mode
,
3990 TREE_TYPE (current_function_decl
), 1);
3991 callee_promoted_mode
3992 = promote_function_mode (TREE_TYPE (funtype
), callee_mode
,
3995 if (caller_mode
!= VOIDmode
3996 && (caller_promoted_mode
!= callee_promoted_mode
3997 || ((caller_mode
!= caller_promoted_mode
3998 || callee_mode
!= callee_promoted_mode
)
3999 && (caller_unsignedp
!= callee_unsignedp
4000 || partial_subreg_p (caller_mode
, callee_mode
)))))
4003 maybe_complain_about_tail_call (exp
,
4004 "caller and callee disagree in"
4005 " promotion of function"
4010 /* Ensure current function's preferred stack boundary is at least
4011 what we need. Stack alignment may also increase preferred stack
4013 for (i
= 0; i
< num_actuals
; i
++)
4014 if (reg_parm_stack_space
> 0
4016 || args
[i
].partial
!= 0
4017 || args
[i
].pass_on_stack
)
4018 update_stack_alignment_for_call (&args
[i
].locate
);
4019 if (crtl
->preferred_stack_boundary
< preferred_stack_boundary
)
4020 crtl
->preferred_stack_boundary
= preferred_stack_boundary
;
4022 preferred_stack_boundary
= crtl
->preferred_stack_boundary
;
4024 preferred_unit_stack_boundary
= preferred_stack_boundary
/ BITS_PER_UNIT
;
4026 if (flag_callgraph_info
)
4027 record_final_call (fndecl
, EXPR_LOCATION (exp
));
4029 /* We want to make two insn chains; one for a sibling call, the other
4030 for a normal call. We will select one of the two chains after
4031 initial RTL generation is complete. */
4032 for (pass
= try_tail_call
? 0 : 1; pass
< 2; pass
++)
4034 int sibcall_failure
= 0;
4035 /* We want to emit any pending stack adjustments before the tail
4036 recursion "call". That way we know any adjustment after the tail
4037 recursion call can be ignored if we indeed use the tail
4039 saved_pending_stack_adjust save
;
4040 rtx_insn
*insns
, *before_call
, *after_args
;
4045 /* State variables we need to save and restore between
4047 save_pending_stack_adjust (&save
);
4050 flags
&= ~ECF_SIBCALL
;
4052 flags
|= ECF_SIBCALL
;
4054 /* Other state variables that we must reinitialize each time
4055 through the loop (that are not initialized by the loop itself). */
4059 /* Start a new sequence for the normal call case.
4061 From this point on, if the sibling call fails, we want to set
4062 sibcall_failure instead of continuing the loop. */
4065 /* Don't let pending stack adjusts add up to too much.
4066 Also, do all pending adjustments now if there is any chance
4067 this might be a call to alloca or if we are expanding a sibling
4069 Also do the adjustments before a throwing call, otherwise
4070 exception handling can fail; PR 19225. */
4071 if (maybe_ge (pending_stack_adjust
, 32)
4072 || (maybe_ne (pending_stack_adjust
, 0)
4073 && (flags
& ECF_MAY_BE_ALLOCA
))
4074 || (maybe_ne (pending_stack_adjust
, 0)
4075 && flag_exceptions
&& !(flags
& ECF_NOTHROW
))
4077 do_pending_stack_adjust ();
4079 /* Precompute any arguments as needed. */
4081 precompute_arguments (num_actuals
, args
);
4083 /* Now we are about to start emitting insns that can be deleted
4084 if a libcall is deleted. */
4085 if (pass
&& (flags
& ECF_MALLOC
))
4089 && crtl
->stack_protect_guard
4090 && targetm
.stack_protect_runtime_enabled_p ())
4091 stack_protect_epilogue ();
4093 adjusted_args_size
= args_size
;
4094 /* Compute the actual size of the argument block required. The variable
4095 and constant sizes must be combined, the size may have to be rounded,
4096 and there may be a minimum required size. When generating a sibcall
4097 pattern, do not round up, since we'll be re-using whatever space our
4099 unadjusted_args_size
4100 = compute_argument_block_size (reg_parm_stack_space
,
4101 &adjusted_args_size
,
4104 : preferred_stack_boundary
));
4106 old_stack_allocated
= stack_pointer_delta
- pending_stack_adjust
;
4108 /* The argument block when performing a sibling call is the
4109 incoming argument block. */
4112 argblock
= crtl
->args
.internal_arg_pointer
;
4113 if (STACK_GROWS_DOWNWARD
)
4115 = plus_constant (Pmode
, argblock
, crtl
->args
.pretend_args_size
);
4118 = plus_constant (Pmode
, argblock
, -crtl
->args
.pretend_args_size
);
4120 HOST_WIDE_INT map_size
= constant_lower_bound (args_size
.constant
);
4121 stored_args_map
= sbitmap_alloc (map_size
);
4122 bitmap_clear (stored_args_map
);
4123 stored_args_watermark
= HOST_WIDE_INT_M1U
;
4126 /* If we have no actual push instructions, or shouldn't use them,
4127 make space for all args right now. */
4128 else if (adjusted_args_size
.var
!= 0)
4130 if (old_stack_level
== 0)
4132 emit_stack_save (SAVE_BLOCK
, &old_stack_level
);
4133 old_stack_pointer_delta
= stack_pointer_delta
;
4134 old_pending_adj
= pending_stack_adjust
;
4135 pending_stack_adjust
= 0;
4136 /* stack_arg_under_construction says whether a stack arg is
4137 being constructed at the old stack level. Pushing the stack
4138 gets a clean outgoing argument block. */
4139 old_stack_arg_under_construction
= stack_arg_under_construction
;
4140 stack_arg_under_construction
= 0;
4142 argblock
= push_block (ARGS_SIZE_RTX (adjusted_args_size
), 0, 0);
4143 if (flag_stack_usage_info
)
4144 current_function_has_unbounded_dynamic_stack_size
= 1;
4148 /* Note that we must go through the motions of allocating an argument
4149 block even if the size is zero because we may be storing args
4150 in the area reserved for register arguments, which may be part of
4153 poly_int64 needed
= adjusted_args_size
.constant
;
4155 /* Store the maximum argument space used. It will be pushed by
4156 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
4159 crtl
->outgoing_args_size
= upper_bound (crtl
->outgoing_args_size
,
4162 if (must_preallocate
)
4164 if (ACCUMULATE_OUTGOING_ARGS
)
4166 /* Since the stack pointer will never be pushed, it is
4167 possible for the evaluation of a parm to clobber
4168 something we have already written to the stack.
4169 Since most function calls on RISC machines do not use
4170 the stack, this is uncommon, but must work correctly.
4172 Therefore, we save any area of the stack that was already
4173 written and that we are using. Here we set up to do this
4174 by making a new stack usage map from the old one. The
4175 actual save will be done by store_one_arg.
4177 Another approach might be to try to reorder the argument
4178 evaluations to avoid this conflicting stack usage. */
4180 /* Since we will be writing into the entire argument area,
4181 the map must be allocated for its entire size, not just
4182 the part that is the responsibility of the caller. */
4183 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl
? fntype
: TREE_TYPE (fndecl
))))
4184 needed
+= reg_parm_stack_space
;
4186 poly_int64 limit
= needed
;
4187 if (ARGS_GROW_DOWNWARD
)
4190 /* For polynomial sizes, this is the maximum possible
4191 size needed for arguments with a constant size
4193 HOST_WIDE_INT const_limit
= constant_lower_bound (limit
);
4194 highest_outgoing_arg_in_use
4195 = MAX (initial_highest_arg_in_use
, const_limit
);
4197 free (stack_usage_map_buf
);
4198 stack_usage_map_buf
= XNEWVEC (char, highest_outgoing_arg_in_use
);
4199 stack_usage_map
= stack_usage_map_buf
;
4201 if (initial_highest_arg_in_use
)
4202 memcpy (stack_usage_map
, initial_stack_usage_map
,
4203 initial_highest_arg_in_use
);
4205 if (initial_highest_arg_in_use
!= highest_outgoing_arg_in_use
)
4206 memset (&stack_usage_map
[initial_highest_arg_in_use
], 0,
4207 (highest_outgoing_arg_in_use
4208 - initial_highest_arg_in_use
));
4211 /* The address of the outgoing argument list must not be
4212 copied to a register here, because argblock would be left
4213 pointing to the wrong place after the call to
4214 allocate_dynamic_stack_space below. */
4216 argblock
= virtual_outgoing_args_rtx
;
4220 /* Try to reuse some or all of the pending_stack_adjust
4221 to get this space. */
4222 if (inhibit_defer_pop
== 0
4223 && (combine_pending_stack_adjustment_and_call
4225 unadjusted_args_size
,
4226 &adjusted_args_size
,
4227 preferred_unit_stack_boundary
)))
4229 /* combine_pending_stack_adjustment_and_call computes
4230 an adjustment before the arguments are allocated.
4231 Account for them and see whether or not the stack
4232 needs to go up or down. */
4233 needed
= unadjusted_args_size
- needed
;
4236 combine_pending_stack_adjustment_and_call. */
4237 gcc_checking_assert (ordered_p (needed
, 0));
4238 if (maybe_lt (needed
, 0))
4240 /* We're releasing stack space. */
4241 /* ??? We can avoid any adjustment at all if we're
4242 already aligned. FIXME. */
4243 pending_stack_adjust
= -needed
;
4244 do_pending_stack_adjust ();
4248 /* We need to allocate space. We'll do that in
4249 push_block below. */
4250 pending_stack_adjust
= 0;
4253 /* Special case this because overhead of `push_block' in
4254 this case is non-trivial. */
4255 if (known_eq (needed
, 0))
4256 argblock
= virtual_outgoing_args_rtx
;
4259 rtx needed_rtx
= gen_int_mode (needed
, Pmode
);
4260 argblock
= push_block (needed_rtx
, 0, 0);
4261 if (ARGS_GROW_DOWNWARD
)
4262 argblock
= plus_constant (Pmode
, argblock
, needed
);
4265 /* We only really need to call `copy_to_reg' in the case
4266 where push insns are going to be used to pass ARGBLOCK
4267 to a function call in ARGS. In that case, the stack
4268 pointer changes value from the allocation point to the
4269 call point, and hence the value of
4270 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
4271 as well always do it. */
4272 argblock
= copy_to_reg (argblock
);
4277 if (ACCUMULATE_OUTGOING_ARGS
)
4279 /* The save/restore code in store_one_arg handles all
4280 cases except one: a constructor call (including a C
4281 function returning a BLKmode struct) to initialize
4283 if (stack_arg_under_construction
)
4287 (adjusted_args_size
.constant
4288 + (OUTGOING_REG_PARM_STACK_SPACE (!fndecl
? fntype
4289 : TREE_TYPE (fndecl
))
4290 ? 0 : reg_parm_stack_space
), Pmode
));
4291 if (old_stack_level
== 0)
4293 emit_stack_save (SAVE_BLOCK
, &old_stack_level
);
4294 old_stack_pointer_delta
= stack_pointer_delta
;
4295 old_pending_adj
= pending_stack_adjust
;
4296 pending_stack_adjust
= 0;
4297 /* stack_arg_under_construction says whether a stack
4298 arg is being constructed at the old stack level.
4299 Pushing the stack gets a clean outgoing argument
4301 old_stack_arg_under_construction
4302 = stack_arg_under_construction
;
4303 stack_arg_under_construction
= 0;
4304 /* Make a new map for the new argument list. */
4305 free (stack_usage_map_buf
);
4306 stack_usage_map_buf
= XCNEWVEC (char, highest_outgoing_arg_in_use
);
4307 stack_usage_map
= stack_usage_map_buf
;
4308 highest_outgoing_arg_in_use
= 0;
4309 stack_usage_watermark
= HOST_WIDE_INT_M1U
;
4311 /* We can pass TRUE as the 4th argument because we just
4312 saved the stack pointer and will restore it right after
4314 allocate_dynamic_stack_space (push_size
, 0, BIGGEST_ALIGNMENT
,
4318 /* If argument evaluation might modify the stack pointer,
4319 copy the address of the argument list to a register. */
4320 for (i
= 0; i
< num_actuals
; i
++)
4321 if (args
[i
].pass_on_stack
)
4323 argblock
= copy_addr_to_reg (argblock
);
4328 compute_argument_addresses (args
, argblock
, num_actuals
);
4330 /* Stack is properly aligned, pops can't safely be deferred during
4331 the evaluation of the arguments. */
4334 /* Precompute all register parameters. It isn't safe to compute
4335 anything once we have started filling any specific hard regs.
4336 TLS symbols sometimes need a call to resolve. Precompute
4337 register parameters before any stack pointer manipulation
4338 to avoid unaligned stack in the called function. */
4339 precompute_register_parameters (num_actuals
, args
, ®_parm_seen
);
4343 /* Perform stack alignment before the first push (the last arg). */
4345 && maybe_gt (adjusted_args_size
.constant
, reg_parm_stack_space
)
4346 && maybe_ne (adjusted_args_size
.constant
, unadjusted_args_size
))
4348 /* When the stack adjustment is pending, we get better code
4349 by combining the adjustments. */
4350 if (maybe_ne (pending_stack_adjust
, 0)
4351 && ! inhibit_defer_pop
4352 && (combine_pending_stack_adjustment_and_call
4353 (&pending_stack_adjust
,
4354 unadjusted_args_size
,
4355 &adjusted_args_size
,
4356 preferred_unit_stack_boundary
)))
4357 do_pending_stack_adjust ();
4358 else if (argblock
== 0)
4359 anti_adjust_stack (gen_int_mode (adjusted_args_size
.constant
4360 - unadjusted_args_size
,
4363 /* Now that the stack is properly aligned, pops can't safely
4364 be deferred during the evaluation of the arguments. */
4367 /* Record the maximum pushed stack space size. We need to delay
4368 doing it this far to take into account the optimization done
4369 by combine_pending_stack_adjustment_and_call. */
4370 if (flag_stack_usage_info
4371 && !ACCUMULATE_OUTGOING_ARGS
4373 && adjusted_args_size
.var
== 0)
4375 poly_int64 pushed
= (adjusted_args_size
.constant
4376 + pending_stack_adjust
);
4377 current_function_pushed_stack_size
4378 = upper_bound (current_function_pushed_stack_size
, pushed
);
4381 funexp
= rtx_for_function_call (fndecl
, addr
);
4383 if (CALL_EXPR_STATIC_CHAIN (exp
))
4384 static_chain_value
= expand_normal (CALL_EXPR_STATIC_CHAIN (exp
));
4386 static_chain_value
= 0;
4388 #ifdef REG_PARM_STACK_SPACE
4389 /* Save the fixed argument area if it's part of the caller's frame and
4390 is clobbered by argument setup for this call. */
4391 if (ACCUMULATE_OUTGOING_ARGS
&& pass
)
4392 save_area
= save_fixed_argument_area (reg_parm_stack_space
, argblock
,
4393 &low_to_save
, &high_to_save
);
4396 /* Now store (and compute if necessary) all non-register parms.
4397 These come before register parms, since they can require block-moves,
4398 which could clobber the registers used for register parms.
4399 Parms which have partial registers are not stored here,
4400 but we do preallocate space here if they want that. */
4402 for (i
= 0; i
< num_actuals
; i
++)
4404 if (args
[i
].reg
== 0 || args
[i
].pass_on_stack
)
4406 rtx_insn
*before_arg
= get_last_insn ();
4408 /* We don't allow passing huge (> 2^30 B) arguments
4409 by value. It would cause an overflow later on. */
4410 if (constant_lower_bound (adjusted_args_size
.constant
)
4411 >= (1 << (HOST_BITS_PER_INT
- 2)))
4413 sorry ("passing too large argument on stack");
4417 if (store_one_arg (&args
[i
], argblock
, flags
,
4418 adjusted_args_size
.var
!= 0,
4419 reg_parm_stack_space
)
4421 && check_sibcall_argument_overlap (before_arg
,
4423 sibcall_failure
= 1;
4428 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)),
4429 gen_rtx_USE (VOIDmode
, args
[i
].stack
),
4433 /* If we have a parm that is passed in registers but not in memory
4434 and whose alignment does not permit a direct copy into registers,
4435 make a group of pseudos that correspond to each register that we
4437 if (STRICT_ALIGNMENT
)
4438 store_unaligned_arguments_into_pseudos (args
, num_actuals
);
4440 /* Now store any partially-in-registers parm.
4441 This is the last place a block-move can happen. */
4443 for (i
= 0; i
< num_actuals
; i
++)
4444 if (args
[i
].partial
!= 0 && ! args
[i
].pass_on_stack
)
4446 rtx_insn
*before_arg
= get_last_insn ();
4448 /* On targets with weird calling conventions (e.g. PA) it's
4449 hard to ensure that all cases of argument overlap between
4450 stack and registers work. Play it safe and bail out. */
4451 if (ARGS_GROW_DOWNWARD
&& !STACK_GROWS_DOWNWARD
)
4453 sibcall_failure
= 1;
4457 if (store_one_arg (&args
[i
], argblock
, flags
,
4458 adjusted_args_size
.var
!= 0,
4459 reg_parm_stack_space
)
4461 && check_sibcall_argument_overlap (before_arg
,
4463 sibcall_failure
= 1;
4466 bool any_regs
= false;
4467 for (i
= 0; i
< num_actuals
; i
++)
4468 if (args
[i
].reg
!= NULL_RTX
)
4471 targetm
.calls
.call_args (args
[i
].reg
, funtype
);
4474 targetm
.calls
.call_args (pc_rtx
, funtype
);
4476 /* Figure out the register where the value, if any, will come back. */
4478 if (TYPE_MODE (rettype
) != VOIDmode
4479 && ! structure_value_addr
)
4481 if (pcc_struct_value
)
4482 valreg
= hard_function_value (build_pointer_type (rettype
),
4483 fndecl
, NULL
, (pass
== 0));
4485 valreg
= hard_function_value (rettype
, fndecl
, fntype
,
4488 /* If VALREG is a PARALLEL whose first member has a zero
4489 offset, use that. This is for targets such as m68k that
4490 return the same value in multiple places. */
4491 if (GET_CODE (valreg
) == PARALLEL
)
4493 rtx elem
= XVECEXP (valreg
, 0, 0);
4494 rtx where
= XEXP (elem
, 0);
4495 rtx offset
= XEXP (elem
, 1);
4496 if (offset
== const0_rtx
4497 && GET_MODE (where
) == GET_MODE (valreg
))
4502 /* If register arguments require space on the stack and stack space
4503 was not preallocated, allocate stack space here for arguments
4504 passed in registers. */
4505 if (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl
? fntype
: TREE_TYPE (fndecl
)))
4506 && !ACCUMULATE_OUTGOING_ARGS
4507 && must_preallocate
== 0 && reg_parm_stack_space
> 0)
4508 anti_adjust_stack (GEN_INT (reg_parm_stack_space
));
4510 /* Pass the function the address in which to return a
4512 if (pass
!= 0 && structure_value_addr
&& ! structure_value_addr_parm
)
4514 structure_value_addr
4515 = convert_memory_address (Pmode
, structure_value_addr
);
4516 emit_move_insn (struct_value
,
4518 force_operand (structure_value_addr
,
4521 if (REG_P (struct_value
))
4522 use_reg (&call_fusage
, struct_value
);
4525 after_args
= get_last_insn ();
4526 funexp
= prepare_call_address (fndecl
? fndecl
: fntype
, funexp
,
4527 static_chain_value
, &call_fusage
,
4528 reg_parm_seen
, flags
);
4530 load_register_parameters (args
, num_actuals
, &call_fusage
, flags
,
4531 pass
== 0, &sibcall_failure
);
4533 /* Save a pointer to the last insn before the call, so that we can
4534 later safely search backwards to find the CALL_INSN. */
4535 before_call
= get_last_insn ();
4537 /* Set up next argument register. For sibling calls on machines
4538 with register windows this should be the incoming register. */
4540 next_arg_reg
= targetm
.calls
.function_incoming_arg
4541 (args_so_far
, function_arg_info::end_marker ());
4543 next_arg_reg
= targetm
.calls
.function_arg
4544 (args_so_far
, function_arg_info::end_marker ());
4546 if (pass
== 1 && (return_flags
& ERF_RETURNS_ARG
))
4548 int arg_nr
= return_flags
& ERF_RETURN_ARG_MASK
;
4549 arg_nr
= num_actuals
- arg_nr
- 1;
4551 && arg_nr
< num_actuals
4555 && GET_MODE (args
[arg_nr
].reg
) == GET_MODE (valreg
))
4557 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args
[arg_nr
].tree_value
)),
4558 gen_rtx_SET (valreg
, args
[arg_nr
].reg
),
4561 /* All arguments and registers used for the call must be set up by
4564 /* Stack must be properly aligned now. */
4566 || multiple_p (stack_pointer_delta
,
4567 preferred_unit_stack_boundary
));
4569 /* Generate the actual call instruction. */
4570 emit_call_1 (funexp
, exp
, fndecl
, funtype
, unadjusted_args_size
,
4571 adjusted_args_size
.constant
, struct_value_size
,
4572 next_arg_reg
, valreg
, old_inhibit_defer_pop
, call_fusage
,
4573 flags
, args_so_far
);
4577 rtx_call_insn
*last
;
4578 rtx datum
= NULL_RTX
;
4579 if (fndecl
!= NULL_TREE
)
4581 datum
= XEXP (DECL_RTL (fndecl
), 0);
4582 gcc_assert (datum
!= NULL_RTX
4583 && GET_CODE (datum
) == SYMBOL_REF
);
4585 last
= last_call_insn ();
4586 add_reg_note (last
, REG_CALL_DECL
, datum
);
4589 /* If the call setup or the call itself overlaps with anything
4590 of the argument setup we probably clobbered our call address.
4591 In that case we can't do sibcalls. */
4593 && check_sibcall_argument_overlap (after_args
, 0, 0))
4594 sibcall_failure
= 1;
4596 /* If a non-BLKmode value is returned at the most significant end
4597 of a register, shift the register right by the appropriate amount
4598 and update VALREG accordingly. BLKmode values are handled by the
4599 group load/store machinery below. */
4600 if (!structure_value_addr
4601 && !pcc_struct_value
4602 && TYPE_MODE (rettype
) != VOIDmode
4603 && TYPE_MODE (rettype
) != BLKmode
4605 && targetm
.calls
.return_in_msb (rettype
))
4607 if (shift_return_value (TYPE_MODE (rettype
), false, valreg
))
4608 sibcall_failure
= 1;
4609 valreg
= gen_rtx_REG (TYPE_MODE (rettype
), REGNO (valreg
));
4612 if (pass
&& (flags
& ECF_MALLOC
))
4614 rtx temp
= gen_reg_rtx (GET_MODE (valreg
));
4615 rtx_insn
*last
, *insns
;
4617 /* The return value from a malloc-like function is a pointer. */
4618 if (TREE_CODE (rettype
) == POINTER_TYPE
)
4619 mark_reg_pointer (temp
, MALLOC_ABI_ALIGNMENT
);
4621 emit_move_insn (temp
, valreg
);
4623 /* The return value from a malloc-like function cannot alias
4625 last
= get_last_insn ();
4626 add_reg_note (last
, REG_NOALIAS
, temp
);
4628 /* Write out the sequence. */
4629 insns
= get_insns ();
4635 /* For calls to `setjmp', etc., inform
4636 function.c:setjmp_warnings that it should complain if
4637 nonvolatile values are live. For functions that cannot
4638 return, inform flow that control does not fall through. */
4640 if ((flags
& ECF_NORETURN
) || pass
== 0)
4642 /* The barrier must be emitted
4643 immediately after the CALL_INSN. Some ports emit more
4644 than just a CALL_INSN above, so we must search for it here. */
4646 rtx_insn
*last
= get_last_insn ();
4647 while (!CALL_P (last
))
4649 last
= PREV_INSN (last
);
4650 /* There was no CALL_INSN? */
4651 gcc_assert (last
!= before_call
);
4654 emit_barrier_after (last
);
4656 /* Stack adjustments after a noreturn call are dead code.
4657 However when NO_DEFER_POP is in effect, we must preserve
4658 stack_pointer_delta. */
4659 if (inhibit_defer_pop
== 0)
4661 stack_pointer_delta
= old_stack_allocated
;
4662 pending_stack_adjust
= 0;
4666 /* If value type not void, return an rtx for the value. */
4668 if (TYPE_MODE (rettype
) == VOIDmode
4670 target
= const0_rtx
;
4671 else if (structure_value_addr
)
4673 if (target
== 0 || !MEM_P (target
))
4676 = gen_rtx_MEM (TYPE_MODE (rettype
),
4677 memory_address (TYPE_MODE (rettype
),
4678 structure_value_addr
));
4679 set_mem_attributes (target
, rettype
, 1);
4682 else if (pcc_struct_value
)
4684 /* This is the special C++ case where we need to
4685 know what the true target was. We take care to
4686 never use this value more than once in one expression. */
4687 target
= gen_rtx_MEM (TYPE_MODE (rettype
),
4688 copy_to_reg (valreg
));
4689 set_mem_attributes (target
, rettype
, 1);
4691 /* Handle calls that return values in multiple non-contiguous locations.
4692 The Irix 6 ABI has examples of this. */
4693 else if (GET_CODE (valreg
) == PARALLEL
)
4696 target
= emit_group_move_into_temps (valreg
);
4697 else if (rtx_equal_p (target
, valreg
))
4699 else if (GET_CODE (target
) == PARALLEL
)
4700 /* Handle the result of a emit_group_move_into_temps
4701 call in the previous pass. */
4702 emit_group_move (target
, valreg
);
4704 emit_group_store (target
, valreg
, rettype
,
4705 int_size_in_bytes (rettype
));
4708 && GET_MODE (target
) == TYPE_MODE (rettype
)
4709 && GET_MODE (target
) == GET_MODE (valreg
))
4711 bool may_overlap
= false;
4713 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
4714 reg to a plain register. */
4715 if (!REG_P (target
) || HARD_REGISTER_P (target
))
4716 valreg
= avoid_likely_spilled_reg (valreg
);
4718 /* If TARGET is a MEM in the argument area, and we have
4719 saved part of the argument area, then we can't store
4720 directly into TARGET as it may get overwritten when we
4721 restore the argument save area below. Don't work too
4722 hard though and simply force TARGET to a register if it
4723 is a MEM; the optimizer is quite likely to sort it out. */
4724 if (ACCUMULATE_OUTGOING_ARGS
&& pass
&& MEM_P (target
))
4725 for (i
= 0; i
< num_actuals
; i
++)
4726 if (args
[i
].save_area
)
4733 target
= copy_to_reg (valreg
);
4736 /* TARGET and VALREG cannot be equal at this point
4737 because the latter would not have
4738 REG_FUNCTION_VALUE_P true, while the former would if
4739 it were referring to the same register.
4741 If they refer to the same register, this move will be
4742 a no-op, except when function inlining is being
4744 emit_move_insn (target
, valreg
);
4746 /* If we are setting a MEM, this code must be executed.
4747 Since it is emitted after the call insn, sibcall
4748 optimization cannot be performed in that case. */
4750 sibcall_failure
= 1;
4754 target
= copy_to_reg (avoid_likely_spilled_reg (valreg
));
4756 /* If we promoted this return value, make the proper SUBREG.
4757 TARGET might be const0_rtx here, so be careful. */
4759 && TYPE_MODE (rettype
) != BLKmode
4760 && GET_MODE (target
) != TYPE_MODE (rettype
))
4762 tree type
= rettype
;
4763 int unsignedp
= TYPE_UNSIGNED (type
);
4766 /* Ensure we promote as expected, and get the new unsignedness. */
4767 pmode
= promote_function_mode (type
, TYPE_MODE (type
), &unsignedp
,
4769 gcc_assert (GET_MODE (target
) == pmode
);
4771 poly_uint64 offset
= subreg_lowpart_offset (TYPE_MODE (type
),
4773 target
= gen_rtx_SUBREG (TYPE_MODE (type
), target
, offset
);
4774 SUBREG_PROMOTED_VAR_P (target
) = 1;
4775 SUBREG_PROMOTED_SET (target
, unsignedp
);
4778 /* If size of args is variable or this was a constructor call for a stack
4779 argument, restore saved stack-pointer value. */
4781 if (old_stack_level
)
4783 rtx_insn
*prev
= get_last_insn ();
4785 emit_stack_restore (SAVE_BLOCK
, old_stack_level
);
4786 stack_pointer_delta
= old_stack_pointer_delta
;
4788 fixup_args_size_notes (prev
, get_last_insn (), stack_pointer_delta
);
4790 pending_stack_adjust
= old_pending_adj
;
4791 old_stack_allocated
= stack_pointer_delta
- pending_stack_adjust
;
4792 stack_arg_under_construction
= old_stack_arg_under_construction
;
4793 highest_outgoing_arg_in_use
= initial_highest_arg_in_use
;
4794 stack_usage_map
= initial_stack_usage_map
;
4795 stack_usage_watermark
= initial_stack_usage_watermark
;
4796 sibcall_failure
= 1;
4798 else if (ACCUMULATE_OUTGOING_ARGS
&& pass
)
4800 #ifdef REG_PARM_STACK_SPACE
4802 restore_fixed_argument_area (save_area
, argblock
,
4803 high_to_save
, low_to_save
);
4806 /* If we saved any argument areas, restore them. */
4807 for (i
= 0; i
< num_actuals
; i
++)
4808 if (args
[i
].save_area
)
4810 machine_mode save_mode
= GET_MODE (args
[i
].save_area
);
4812 = gen_rtx_MEM (save_mode
,
4813 memory_address (save_mode
,
4814 XEXP (args
[i
].stack_slot
, 0)));
4816 if (save_mode
!= BLKmode
)
4817 emit_move_insn (stack_area
, args
[i
].save_area
);
4819 emit_block_move (stack_area
, args
[i
].save_area
,
4821 (args
[i
].locate
.size
.constant
, Pmode
)),
4822 BLOCK_OP_CALL_PARM
);
4825 highest_outgoing_arg_in_use
= initial_highest_arg_in_use
;
4826 stack_usage_map
= initial_stack_usage_map
;
4827 stack_usage_watermark
= initial_stack_usage_watermark
;
4830 /* If this was alloca, record the new stack level. */
4831 if (flags
& ECF_MAY_BE_ALLOCA
)
4832 record_new_stack_level ();
4834 /* Free up storage we no longer need. */
4835 for (i
= 0; i
< num_actuals
; ++i
)
4836 free (args
[i
].aligned_regs
);
4838 targetm
.calls
.end_call_args ();
4840 insns
= get_insns ();
4845 tail_call_insns
= insns
;
4847 /* Restore the pending stack adjustment now that we have
4848 finished generating the sibling call sequence. */
4850 restore_pending_stack_adjust (&save
);
4852 /* Prepare arg structure for next iteration. */
4853 for (i
= 0; i
< num_actuals
; i
++)
4856 args
[i
].aligned_regs
= 0;
4860 sbitmap_free (stored_args_map
);
4861 internal_arg_pointer_exp_state
.scan_start
= NULL
;
4862 internal_arg_pointer_exp_state
.cache
.release ();
4866 normal_call_insns
= insns
;
4868 /* Verify that we've deallocated all the stack we used. */
4869 gcc_assert ((flags
& ECF_NORETURN
)
4870 || known_eq (old_stack_allocated
,
4872 - pending_stack_adjust
));
4875 /* If something prevents making this a sibling call,
4876 zero out the sequence. */
4877 if (sibcall_failure
)
4878 tail_call_insns
= NULL
;
4883 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
4884 arguments too, as argument area is now clobbered by the call. */
4885 if (tail_call_insns
)
4887 emit_insn (tail_call_insns
);
4888 crtl
->tail_call_emit
= true;
4892 emit_insn (normal_call_insns
);
4894 /* Ideally we'd emit a message for all of the ways that it could
4896 maybe_complain_about_tail_call (exp
, "tail call production failed");
4899 currently_expanding_call
--;
4901 free (stack_usage_map_buf
);
4906 /* A sibling call sequence invalidates any REG_EQUIV notes made for
4907 this function's incoming arguments.
4909 At the start of RTL generation we know the only REG_EQUIV notes
4910 in the rtl chain are those for incoming arguments, so we can look
4911 for REG_EQUIV notes between the start of the function and the
4912 NOTE_INSN_FUNCTION_BEG.
4914 This is (slight) overkill. We could keep track of the highest
4915 argument we clobber and be more selective in removing notes, but it
4916 does not seem to be worth the effort. */
4919 fixup_tail_calls (void)
4923 for (insn
= get_insns (); insn
; insn
= NEXT_INSN (insn
))
4927 /* There are never REG_EQUIV notes for the incoming arguments
4928 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
4930 && NOTE_KIND (insn
) == NOTE_INSN_FUNCTION_BEG
)
4933 note
= find_reg_note (insn
, REG_EQUIV
, 0);
4935 remove_note (insn
, note
);
4936 note
= find_reg_note (insn
, REG_EQUIV
, 0);
4941 /* Traverse a list of TYPES and expand all complex types into their
4944 split_complex_types (tree types
)
4948 /* Before allocating memory, check for the common case of no complex. */
4949 for (p
= types
; p
; p
= TREE_CHAIN (p
))
4951 tree type
= TREE_VALUE (p
);
4952 if (TREE_CODE (type
) == COMPLEX_TYPE
4953 && targetm
.calls
.split_complex_arg (type
))
4959 types
= copy_list (types
);
4961 for (p
= types
; p
; p
= TREE_CHAIN (p
))
4963 tree complex_type
= TREE_VALUE (p
);
4965 if (TREE_CODE (complex_type
) == COMPLEX_TYPE
4966 && targetm
.calls
.split_complex_arg (complex_type
))
4970 /* Rewrite complex type with component type. */
4971 TREE_VALUE (p
) = TREE_TYPE (complex_type
);
4972 next
= TREE_CHAIN (p
);
4974 /* Add another component type for the imaginary part. */
4975 imag
= build_tree_list (NULL_TREE
, TREE_VALUE (p
));
4976 TREE_CHAIN (p
) = imag
;
4977 TREE_CHAIN (imag
) = next
;
4979 /* Skip the newly created node. */
4987 /* Output a library call to function ORGFUN (a SYMBOL_REF rtx)
4988 for a value of mode OUTMODE,
4989 with NARGS different arguments, passed as ARGS.
4990 Store the return value if RETVAL is nonzero: store it in VALUE if
4991 VALUE is nonnull, otherwise pick a convenient location. In either
4992 case return the location of the stored value.
4994 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
4995 `const' calls, LCT_PURE for `pure' calls, or another LCT_ value for
4996 other types of library calls. */
4999 emit_library_call_value_1 (int retval
, rtx orgfun
, rtx value
,
5000 enum libcall_type fn_type
,
5001 machine_mode outmode
, int nargs
, rtx_mode_t
*args
)
5003 /* Total size in bytes of all the stack-parms scanned so far. */
5004 struct args_size args_size
;
5005 /* Size of arguments before any adjustments (such as rounding). */
5006 struct args_size original_args_size
;
5009 /* Todo, choose the correct decl type of orgfun. Sadly this information
5010 isn't present here, so we default to native calling abi here. */
5011 tree fndecl ATTRIBUTE_UNUSED
= NULL_TREE
; /* library calls default to host calling abi ? */
5012 tree fntype ATTRIBUTE_UNUSED
= NULL_TREE
; /* library calls default to host calling abi ? */
5015 CUMULATIVE_ARGS args_so_far_v
;
5016 cumulative_args_t args_so_far
;
5023 struct locate_and_pad_arg_data locate
;
5027 int old_inhibit_defer_pop
= inhibit_defer_pop
;
5028 rtx call_fusage
= 0;
5031 int pcc_struct_value
= 0;
5032 poly_int64 struct_value_size
= 0;
5034 int reg_parm_stack_space
= 0;
5036 rtx_insn
*before_call
;
5037 bool have_push_fusage
;
5038 tree tfom
; /* type_for_mode (outmode, 0) */
5040 #ifdef REG_PARM_STACK_SPACE
5041 /* Define the boundary of the register parm stack space that needs to be
5043 int low_to_save
= 0, high_to_save
= 0;
5044 rtx save_area
= 0; /* Place that it is saved. */
5047 /* Size of the stack reserved for parameter registers. */
5048 unsigned int initial_highest_arg_in_use
= highest_outgoing_arg_in_use
;
5049 char *initial_stack_usage_map
= stack_usage_map
;
5050 unsigned HOST_WIDE_INT initial_stack_usage_watermark
= stack_usage_watermark
;
5051 char *stack_usage_map_buf
= NULL
;
5053 rtx struct_value
= targetm
.calls
.struct_value_rtx (0, 0);
5055 #ifdef REG_PARM_STACK_SPACE
5056 reg_parm_stack_space
= REG_PARM_STACK_SPACE ((tree
) 0);
5059 /* By default, library functions cannot throw. */
5060 flags
= ECF_NOTHROW
;
5073 flags
|= ECF_NORETURN
;
5076 flags
&= ~ECF_NOTHROW
;
5078 case LCT_RETURNS_TWICE
:
5079 flags
= ECF_RETURNS_TWICE
;
5084 /* Ensure current function's preferred stack boundary is at least
5086 if (crtl
->preferred_stack_boundary
< PREFERRED_STACK_BOUNDARY
)
5087 crtl
->preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
5089 /* If this kind of value comes back in memory,
5090 decide where in memory it should come back. */
5091 if (outmode
!= VOIDmode
)
5093 tfom
= lang_hooks
.types
.type_for_mode (outmode
, 0);
5094 if (aggregate_value_p (tfom
, 0))
5096 #ifdef PCC_STATIC_STRUCT_RETURN
5098 = hard_function_value (build_pointer_type (tfom
), 0, 0, 0);
5099 mem_value
= gen_rtx_MEM (outmode
, pointer_reg
);
5100 pcc_struct_value
= 1;
5102 value
= gen_reg_rtx (outmode
);
5103 #else /* not PCC_STATIC_STRUCT_RETURN */
5104 struct_value_size
= GET_MODE_SIZE (outmode
);
5105 if (value
!= 0 && MEM_P (value
))
5108 mem_value
= assign_temp (tfom
, 1, 1);
5110 /* This call returns a big structure. */
5111 flags
&= ~(ECF_CONST
| ECF_PURE
| ECF_LOOPING_CONST_OR_PURE
);
5115 tfom
= void_type_node
;
5117 /* ??? Unfinished: must pass the memory address as an argument. */
5119 /* Copy all the libcall-arguments out of the varargs data
5120 and into a vector ARGVEC.
5122 Compute how to pass each argument. We only support a very small subset
5123 of the full argument passing conventions to limit complexity here since
5124 library functions shouldn't have many args. */
5126 argvec
= XALLOCAVEC (struct arg
, nargs
+ 1);
5127 memset (argvec
, 0, (nargs
+ 1) * sizeof (struct arg
));
5129 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
5130 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far_v
, outmode
, fun
);
5132 INIT_CUMULATIVE_ARGS (args_so_far_v
, NULL_TREE
, fun
, 0, nargs
);
5134 args_so_far
= pack_cumulative_args (&args_so_far_v
);
5136 args_size
.constant
= 0;
5143 /* If there's a structure value address to be passed,
5144 either pass it in the special place, or pass it as an extra argument. */
5145 if (mem_value
&& struct_value
== 0 && ! pcc_struct_value
)
5147 rtx addr
= XEXP (mem_value
, 0);
5151 /* Make sure it is a reasonable operand for a move or push insn. */
5152 if (!REG_P (addr
) && !MEM_P (addr
)
5153 && !(CONSTANT_P (addr
)
5154 && targetm
.legitimate_constant_p (Pmode
, addr
)))
5155 addr
= force_operand (addr
, NULL_RTX
);
5157 argvec
[count
].value
= addr
;
5158 argvec
[count
].mode
= Pmode
;
5159 argvec
[count
].partial
= 0;
5161 function_arg_info
ptr_arg (Pmode
, /*named=*/true);
5162 argvec
[count
].reg
= targetm
.calls
.function_arg (args_so_far
, ptr_arg
);
5163 gcc_assert (targetm
.calls
.arg_partial_bytes (args_so_far
, ptr_arg
) == 0);
5165 locate_and_pad_parm (Pmode
, NULL_TREE
,
5166 #ifdef STACK_PARMS_IN_REG_PARM_AREA
5169 argvec
[count
].reg
!= 0,
5171 reg_parm_stack_space
, 0,
5172 NULL_TREE
, &args_size
, &argvec
[count
].locate
);
5174 if (argvec
[count
].reg
== 0 || argvec
[count
].partial
!= 0
5175 || reg_parm_stack_space
> 0)
5176 args_size
.constant
+= argvec
[count
].locate
.size
.constant
;
5178 targetm
.calls
.function_arg_advance (args_so_far
, ptr_arg
);
5183 for (unsigned int i
= 0; count
< nargs
; i
++, count
++)
5185 rtx val
= args
[i
].first
;
5186 function_arg_info
arg (args
[i
].second
, /*named=*/true);
5189 /* We cannot convert the arg value to the mode the library wants here;
5190 must do it earlier where we know the signedness of the arg. */
5191 gcc_assert (arg
.mode
!= BLKmode
5192 && (GET_MODE (val
) == arg
.mode
5193 || GET_MODE (val
) == VOIDmode
));
5195 /* Make sure it is a reasonable operand for a move or push insn. */
5196 if (!REG_P (val
) && !MEM_P (val
)
5197 && !(CONSTANT_P (val
)
5198 && targetm
.legitimate_constant_p (arg
.mode
, val
)))
5199 val
= force_operand (val
, NULL_RTX
);
5201 if (pass_by_reference (&args_so_far_v
, arg
))
5204 int must_copy
= !reference_callee_copied (&args_so_far_v
, arg
);
5206 /* If this was a CONST function, it is now PURE since it now
5208 if (flags
& ECF_CONST
)
5210 flags
&= ~ECF_CONST
;
5214 if (MEM_P (val
) && !must_copy
)
5216 tree val_expr
= MEM_EXPR (val
);
5218 mark_addressable (val_expr
);
5223 slot
= assign_temp (lang_hooks
.types
.type_for_mode (arg
.mode
, 0),
5225 emit_move_insn (slot
, val
);
5228 call_fusage
= gen_rtx_EXPR_LIST (VOIDmode
,
5229 gen_rtx_USE (VOIDmode
, slot
),
5232 call_fusage
= gen_rtx_EXPR_LIST (VOIDmode
,
5233 gen_rtx_CLOBBER (VOIDmode
,
5238 arg
.pass_by_reference
= true;
5239 val
= force_operand (XEXP (slot
, 0), NULL_RTX
);
5242 arg
.mode
= promote_function_mode (NULL_TREE
, arg
.mode
, &unsigned_p
,
5244 argvec
[count
].mode
= arg
.mode
;
5245 argvec
[count
].value
= convert_modes (arg
.mode
, GET_MODE (val
), val
,
5247 argvec
[count
].reg
= targetm
.calls
.function_arg (args_so_far
, arg
);
5249 argvec
[count
].partial
5250 = targetm
.calls
.arg_partial_bytes (args_so_far
, arg
);
5252 if (argvec
[count
].reg
== 0
5253 || argvec
[count
].partial
!= 0
5254 || reg_parm_stack_space
> 0)
5256 locate_and_pad_parm (arg
.mode
, NULL_TREE
,
5257 #ifdef STACK_PARMS_IN_REG_PARM_AREA
5260 argvec
[count
].reg
!= 0,
5262 reg_parm_stack_space
, argvec
[count
].partial
,
5263 NULL_TREE
, &args_size
, &argvec
[count
].locate
);
5264 args_size
.constant
+= argvec
[count
].locate
.size
.constant
;
5265 gcc_assert (!argvec
[count
].locate
.size
.var
);
5267 #ifdef BLOCK_REG_PADDING
5269 /* The argument is passed entirely in registers. See at which
5270 end it should be padded. */
5271 argvec
[count
].locate
.where_pad
=
5272 BLOCK_REG_PADDING (arg
.mode
, NULL_TREE
,
5273 known_le (GET_MODE_SIZE (arg
.mode
),
5277 targetm
.calls
.function_arg_advance (args_so_far
, arg
);
5280 for (int i
= 0; i
< nargs
; i
++)
5281 if (reg_parm_stack_space
> 0
5282 || argvec
[i
].reg
== 0
5283 || argvec
[i
].partial
!= 0)
5284 update_stack_alignment_for_call (&argvec
[i
].locate
);
5286 /* If this machine requires an external definition for library
5287 functions, write one out. */
5288 assemble_external_libcall (fun
);
5290 original_args_size
= args_size
;
5291 args_size
.constant
= (aligned_upper_bound (args_size
.constant
5292 + stack_pointer_delta
,
5294 - stack_pointer_delta
);
5296 args_size
.constant
= upper_bound (args_size
.constant
,
5297 reg_parm_stack_space
);
5299 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl
? fntype
: TREE_TYPE (fndecl
))))
5300 args_size
.constant
-= reg_parm_stack_space
;
5302 crtl
->outgoing_args_size
= upper_bound (crtl
->outgoing_args_size
,
5303 args_size
.constant
);
5305 if (flag_stack_usage_info
&& !ACCUMULATE_OUTGOING_ARGS
)
5307 poly_int64 pushed
= args_size
.constant
+ pending_stack_adjust
;
5308 current_function_pushed_stack_size
5309 = upper_bound (current_function_pushed_stack_size
, pushed
);
5312 if (ACCUMULATE_OUTGOING_ARGS
)
5314 /* Since the stack pointer will never be pushed, it is possible for
5315 the evaluation of a parm to clobber something we have already
5316 written to the stack. Since most function calls on RISC machines
5317 do not use the stack, this is uncommon, but must work correctly.
5319 Therefore, we save any area of the stack that was already written
5320 and that we are using. Here we set up to do this by making a new
5321 stack usage map from the old one.
5323 Another approach might be to try to reorder the argument
5324 evaluations to avoid this conflicting stack usage. */
5326 needed
= args_size
.constant
;
5328 /* Since we will be writing into the entire argument area, the
5329 map must be allocated for its entire size, not just the part that
5330 is the responsibility of the caller. */
5331 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl
? fntype
: TREE_TYPE (fndecl
))))
5332 needed
+= reg_parm_stack_space
;
5334 poly_int64 limit
= needed
;
5335 if (ARGS_GROW_DOWNWARD
)
5338 /* For polynomial sizes, this is the maximum possible size needed
5339 for arguments with a constant size and offset. */
5340 HOST_WIDE_INT const_limit
= constant_lower_bound (limit
);
5341 highest_outgoing_arg_in_use
= MAX (initial_highest_arg_in_use
,
5344 stack_usage_map_buf
= XNEWVEC (char, highest_outgoing_arg_in_use
);
5345 stack_usage_map
= stack_usage_map_buf
;
5347 if (initial_highest_arg_in_use
)
5348 memcpy (stack_usage_map
, initial_stack_usage_map
,
5349 initial_highest_arg_in_use
);
5351 if (initial_highest_arg_in_use
!= highest_outgoing_arg_in_use
)
5352 memset (&stack_usage_map
[initial_highest_arg_in_use
], 0,
5353 highest_outgoing_arg_in_use
- initial_highest_arg_in_use
);
5356 /* We must be careful to use virtual regs before they're instantiated,
5357 and real regs afterwards. Loop optimization, for example, can create
5358 new libcalls after we've instantiated the virtual regs, and if we
5359 use virtuals anyway, they won't match the rtl patterns. */
5361 if (virtuals_instantiated
)
5362 argblock
= plus_constant (Pmode
, stack_pointer_rtx
,
5363 STACK_POINTER_OFFSET
);
5365 argblock
= virtual_outgoing_args_rtx
;
5370 argblock
= push_block (gen_int_mode (args_size
.constant
, Pmode
), 0, 0);
5373 /* We push args individually in reverse order, perform stack alignment
5374 before the first push (the last arg). */
5376 anti_adjust_stack (gen_int_mode (args_size
.constant
5377 - original_args_size
.constant
,
5382 #ifdef REG_PARM_STACK_SPACE
5383 if (ACCUMULATE_OUTGOING_ARGS
)
5385 /* The argument list is the property of the called routine and it
5386 may clobber it. If the fixed area has been used for previous
5387 parameters, we must save and restore it. */
5388 save_area
= save_fixed_argument_area (reg_parm_stack_space
, argblock
,
5389 &low_to_save
, &high_to_save
);
5393 /* When expanding a normal call, args are stored in push order,
5394 which is the reverse of what we have here. */
5395 bool any_regs
= false;
5396 for (int i
= nargs
; i
-- > 0; )
5397 if (argvec
[i
].reg
!= NULL_RTX
)
5399 targetm
.calls
.call_args (argvec
[i
].reg
, NULL_TREE
);
5403 targetm
.calls
.call_args (pc_rtx
, NULL_TREE
);
5405 /* Push the args that need to be pushed. */
5407 have_push_fusage
= false;
5409 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
5410 are to be pushed. */
5411 for (count
= 0; count
< nargs
; count
++, argnum
--)
5413 machine_mode mode
= argvec
[argnum
].mode
;
5414 rtx val
= argvec
[argnum
].value
;
5415 rtx reg
= argvec
[argnum
].reg
;
5416 int partial
= argvec
[argnum
].partial
;
5417 unsigned int parm_align
= argvec
[argnum
].locate
.boundary
;
5418 poly_int64 lower_bound
= 0, upper_bound
= 0;
5420 if (! (reg
!= 0 && partial
== 0))
5424 if (ACCUMULATE_OUTGOING_ARGS
)
5426 /* If this is being stored into a pre-allocated, fixed-size,
5427 stack area, save any previous data at that location. */
5429 if (ARGS_GROW_DOWNWARD
)
5431 /* stack_slot is negative, but we want to index stack_usage_map
5432 with positive values. */
5433 upper_bound
= -argvec
[argnum
].locate
.slot_offset
.constant
+ 1;
5434 lower_bound
= upper_bound
- argvec
[argnum
].locate
.size
.constant
;
5438 lower_bound
= argvec
[argnum
].locate
.slot_offset
.constant
;
5439 upper_bound
= lower_bound
+ argvec
[argnum
].locate
.size
.constant
;
5442 if (stack_region_maybe_used_p (lower_bound
, upper_bound
,
5443 reg_parm_stack_space
))
5445 /* We need to make a save area. */
5447 = argvec
[argnum
].locate
.size
.constant
* BITS_PER_UNIT
;
5448 machine_mode save_mode
5449 = int_mode_for_size (size
, 1).else_blk ();
5451 = plus_constant (Pmode
, argblock
,
5452 argvec
[argnum
].locate
.offset
.constant
);
5454 = gen_rtx_MEM (save_mode
, memory_address (save_mode
, adr
));
5456 if (save_mode
== BLKmode
)
5458 argvec
[argnum
].save_area
5459 = assign_stack_temp (BLKmode
,
5460 argvec
[argnum
].locate
.size
.constant
5463 emit_block_move (validize_mem
5464 (copy_rtx (argvec
[argnum
].save_area
)),
5467 (argvec
[argnum
].locate
.size
.constant
,
5469 BLOCK_OP_CALL_PARM
);
5473 argvec
[argnum
].save_area
= gen_reg_rtx (save_mode
);
5475 emit_move_insn (argvec
[argnum
].save_area
, stack_area
);
5480 emit_push_insn (val
, mode
, NULL_TREE
, NULL_RTX
, parm_align
,
5481 partial
, reg
, 0, argblock
,
5483 (argvec
[argnum
].locate
.offset
.constant
, Pmode
)),
5484 reg_parm_stack_space
,
5485 ARGS_SIZE_RTX (argvec
[argnum
].locate
.alignment_pad
), false);
5487 /* Now mark the segment we just used. */
5488 if (ACCUMULATE_OUTGOING_ARGS
)
5489 mark_stack_region_used (lower_bound
, upper_bound
);
5493 /* Indicate argument access so that alias.c knows that these
5496 use
= plus_constant (Pmode
, argblock
,
5497 argvec
[argnum
].locate
.offset
.constant
);
5498 else if (have_push_fusage
)
5502 /* When arguments are pushed, trying to tell alias.c where
5503 exactly this argument is won't work, because the
5504 auto-increment causes confusion. So we merely indicate
5505 that we access something with a known mode somewhere on
5507 use
= gen_rtx_PLUS (Pmode
, stack_pointer_rtx
,
5508 gen_rtx_SCRATCH (Pmode
));
5509 have_push_fusage
= true;
5511 use
= gen_rtx_MEM (argvec
[argnum
].mode
, use
);
5512 use
= gen_rtx_USE (VOIDmode
, use
);
5513 call_fusage
= gen_rtx_EXPR_LIST (VOIDmode
, use
, call_fusage
);
5519 fun
= prepare_call_address (NULL
, fun
, NULL
, &call_fusage
, 0, 0);
5521 /* Now load any reg parms into their regs. */
5523 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
5524 are to be pushed. */
5525 for (count
= 0; count
< nargs
; count
++, argnum
--)
5527 machine_mode mode
= argvec
[argnum
].mode
;
5528 rtx val
= argvec
[argnum
].value
;
5529 rtx reg
= argvec
[argnum
].reg
;
5530 int partial
= argvec
[argnum
].partial
;
5532 /* Handle calls that pass values in multiple non-contiguous
5533 locations. The PA64 has examples of this for library calls. */
5534 if (reg
!= 0 && GET_CODE (reg
) == PARALLEL
)
5535 emit_group_load (reg
, val
, NULL_TREE
, GET_MODE_SIZE (mode
));
5536 else if (reg
!= 0 && partial
== 0)
5538 emit_move_insn (reg
, val
);
5539 #ifdef BLOCK_REG_PADDING
5540 poly_int64 size
= GET_MODE_SIZE (argvec
[argnum
].mode
);
5542 /* Copied from load_register_parameters. */
5544 /* Handle case where we have a value that needs shifting
5545 up to the msb. eg. a QImode value and we're padding
5546 upward on a BYTES_BIG_ENDIAN machine. */
5547 if (known_lt (size
, UNITS_PER_WORD
)
5548 && (argvec
[argnum
].locate
.where_pad
5549 == (BYTES_BIG_ENDIAN
? PAD_UPWARD
: PAD_DOWNWARD
)))
5552 poly_int64 shift
= (UNITS_PER_WORD
- size
) * BITS_PER_UNIT
;
5554 /* Assigning REG here rather than a temp makes CALL_FUSAGE
5555 report the whole reg as used. Strictly speaking, the
5556 call only uses SIZE bytes at the msb end, but it doesn't
5557 seem worth generating rtl to say that. */
5558 reg
= gen_rtx_REG (word_mode
, REGNO (reg
));
5559 x
= expand_shift (LSHIFT_EXPR
, word_mode
, reg
, shift
, reg
, 1);
5561 emit_move_insn (reg
, x
);
5569 /* Any regs containing parms remain in use through the call. */
5570 for (count
= 0; count
< nargs
; count
++)
5572 rtx reg
= argvec
[count
].reg
;
5573 if (reg
!= 0 && GET_CODE (reg
) == PARALLEL
)
5574 use_group_regs (&call_fusage
, reg
);
5577 int partial
= argvec
[count
].partial
;
5581 gcc_assert (partial
% UNITS_PER_WORD
== 0);
5582 nregs
= partial
/ UNITS_PER_WORD
;
5583 use_regs (&call_fusage
, REGNO (reg
), nregs
);
5586 use_reg (&call_fusage
, reg
);
5590 /* Pass the function the address in which to return a structure value. */
5591 if (mem_value
!= 0 && struct_value
!= 0 && ! pcc_struct_value
)
5593 emit_move_insn (struct_value
,
5595 force_operand (XEXP (mem_value
, 0),
5597 if (REG_P (struct_value
))
5598 use_reg (&call_fusage
, struct_value
);
5601 /* Don't allow popping to be deferred, since then
5602 cse'ing of library calls could delete a call and leave the pop. */
5604 valreg
= (mem_value
== 0 && outmode
!= VOIDmode
5605 ? hard_libcall_value (outmode
, orgfun
) : NULL_RTX
);
5607 /* Stack must be properly aligned now. */
5608 gcc_assert (multiple_p (stack_pointer_delta
,
5609 PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
));
5611 before_call
= get_last_insn ();
5613 if (flag_callgraph_info
)
5614 record_final_call (SYMBOL_REF_DECL (orgfun
), UNKNOWN_LOCATION
);
5616 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
5617 will set inhibit_defer_pop to that value. */
5618 /* The return type is needed to decide how many bytes the function pops.
5619 Signedness plays no role in that, so for simplicity, we pretend it's
5620 always signed. We also assume that the list of arguments passed has
5621 no impact, so we pretend it is unknown. */
5623 emit_call_1 (fun
, NULL
,
5624 get_identifier (XSTR (orgfun
, 0)),
5625 build_function_type (tfom
, NULL_TREE
),
5626 original_args_size
.constant
, args_size
.constant
,
5628 targetm
.calls
.function_arg (args_so_far
,
5629 function_arg_info::end_marker ()),
5631 old_inhibit_defer_pop
+ 1, call_fusage
, flags
, args_so_far
);
5636 gcc_assert (GET_CODE (datum
) == SYMBOL_REF
);
5637 rtx_call_insn
*last
= last_call_insn ();
5638 add_reg_note (last
, REG_CALL_DECL
, datum
);
5641 /* Right-shift returned value if necessary. */
5642 if (!pcc_struct_value
5643 && TYPE_MODE (tfom
) != BLKmode
5644 && targetm
.calls
.return_in_msb (tfom
))
5646 shift_return_value (TYPE_MODE (tfom
), false, valreg
);
5647 valreg
= gen_rtx_REG (TYPE_MODE (tfom
), REGNO (valreg
));
5650 targetm
.calls
.end_call_args ();
5652 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
5653 that it should complain if nonvolatile values are live. For
5654 functions that cannot return, inform flow that control does not
5656 if (flags
& ECF_NORETURN
)
5658 /* The barrier note must be emitted
5659 immediately after the CALL_INSN. Some ports emit more than
5660 just a CALL_INSN above, so we must search for it here. */
5661 rtx_insn
*last
= get_last_insn ();
5662 while (!CALL_P (last
))
5664 last
= PREV_INSN (last
);
5665 /* There was no CALL_INSN? */
5666 gcc_assert (last
!= before_call
);
5669 emit_barrier_after (last
);
5672 /* Consider that "regular" libcalls, i.e. all of them except for LCT_THROW
5673 and LCT_RETURNS_TWICE, cannot perform non-local gotos. */
5674 if (flags
& ECF_NOTHROW
)
5676 rtx_insn
*last
= get_last_insn ();
5677 while (!CALL_P (last
))
5679 last
= PREV_INSN (last
);
5680 /* There was no CALL_INSN? */
5681 gcc_assert (last
!= before_call
);
5684 make_reg_eh_region_note_nothrow_nononlocal (last
);
5687 /* Now restore inhibit_defer_pop to its actual original value. */
5692 /* Copy the value to the right place. */
5693 if (outmode
!= VOIDmode
&& retval
)
5699 if (value
!= mem_value
)
5700 emit_move_insn (value
, mem_value
);
5702 else if (GET_CODE (valreg
) == PARALLEL
)
5705 value
= gen_reg_rtx (outmode
);
5706 emit_group_store (value
, valreg
, NULL_TREE
, GET_MODE_SIZE (outmode
));
5710 /* Convert to the proper mode if a promotion has been active. */
5711 if (GET_MODE (valreg
) != outmode
)
5713 int unsignedp
= TYPE_UNSIGNED (tfom
);
5715 gcc_assert (promote_function_mode (tfom
, outmode
, &unsignedp
,
5716 fndecl
? TREE_TYPE (fndecl
) : fntype
, 1)
5717 == GET_MODE (valreg
));
5718 valreg
= convert_modes (outmode
, GET_MODE (valreg
), valreg
, 0);
5722 emit_move_insn (value
, valreg
);
5728 if (ACCUMULATE_OUTGOING_ARGS
)
5730 #ifdef REG_PARM_STACK_SPACE
5732 restore_fixed_argument_area (save_area
, argblock
,
5733 high_to_save
, low_to_save
);
5736 /* If we saved any argument areas, restore them. */
5737 for (count
= 0; count
< nargs
; count
++)
5738 if (argvec
[count
].save_area
)
5740 machine_mode save_mode
= GET_MODE (argvec
[count
].save_area
);
5741 rtx adr
= plus_constant (Pmode
, argblock
,
5742 argvec
[count
].locate
.offset
.constant
);
5743 rtx stack_area
= gen_rtx_MEM (save_mode
,
5744 memory_address (save_mode
, adr
));
5746 if (save_mode
== BLKmode
)
5747 emit_block_move (stack_area
,
5749 (copy_rtx (argvec
[count
].save_area
)),
5751 (argvec
[count
].locate
.size
.constant
, Pmode
)),
5752 BLOCK_OP_CALL_PARM
);
5754 emit_move_insn (stack_area
, argvec
[count
].save_area
);
5757 highest_outgoing_arg_in_use
= initial_highest_arg_in_use
;
5758 stack_usage_map
= initial_stack_usage_map
;
5759 stack_usage_watermark
= initial_stack_usage_watermark
;
5762 free (stack_usage_map_buf
);
5769 /* Store a single argument for a function call
5770 into the register or memory area where it must be passed.
5771 *ARG describes the argument value and where to pass it.
5773 ARGBLOCK is the address of the stack-block for all the arguments,
5774 or 0 on a machine where arguments are pushed individually.
5776 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
5777 so must be careful about how the stack is used.
5779 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
5780 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
5781 that we need not worry about saving and restoring the stack.
5783 FNDECL is the declaration of the function we are calling.
5785 Return nonzero if this arg should cause sibcall failure,
5789 store_one_arg (struct arg_data
*arg
, rtx argblock
, int flags
,
5790 int variable_size ATTRIBUTE_UNUSED
, int reg_parm_stack_space
)
5792 tree pval
= arg
->tree_value
;
5795 poly_int64 used
= 0;
5796 poly_int64 lower_bound
= 0, upper_bound
= 0;
5797 int sibcall_failure
= 0;
5799 if (TREE_CODE (pval
) == ERROR_MARK
)
5802 /* Push a new temporary level for any temporaries we make for
5806 if (ACCUMULATE_OUTGOING_ARGS
&& !(flags
& ECF_SIBCALL
))
5808 /* If this is being stored into a pre-allocated, fixed-size, stack area,
5809 save any previous data at that location. */
5810 if (argblock
&& ! variable_size
&& arg
->stack
)
5812 if (ARGS_GROW_DOWNWARD
)
5814 /* stack_slot is negative, but we want to index stack_usage_map
5815 with positive values. */
5816 if (GET_CODE (XEXP (arg
->stack_slot
, 0)) == PLUS
)
5818 rtx offset
= XEXP (XEXP (arg
->stack_slot
, 0), 1);
5819 upper_bound
= -rtx_to_poly_int64 (offset
) + 1;
5824 lower_bound
= upper_bound
- arg
->locate
.size
.constant
;
5828 if (GET_CODE (XEXP (arg
->stack_slot
, 0)) == PLUS
)
5830 rtx offset
= XEXP (XEXP (arg
->stack_slot
, 0), 1);
5831 lower_bound
= rtx_to_poly_int64 (offset
);
5836 upper_bound
= lower_bound
+ arg
->locate
.size
.constant
;
5839 if (stack_region_maybe_used_p (lower_bound
, upper_bound
,
5840 reg_parm_stack_space
))
5842 /* We need to make a save area. */
5843 poly_uint64 size
= arg
->locate
.size
.constant
* BITS_PER_UNIT
;
5844 machine_mode save_mode
5845 = int_mode_for_size (size
, 1).else_blk ();
5846 rtx adr
= memory_address (save_mode
, XEXP (arg
->stack_slot
, 0));
5847 rtx stack_area
= gen_rtx_MEM (save_mode
, adr
);
5849 if (save_mode
== BLKmode
)
5852 = assign_temp (TREE_TYPE (arg
->tree_value
), 1, 1);
5853 preserve_temp_slots (arg
->save_area
);
5854 emit_block_move (validize_mem (copy_rtx (arg
->save_area
)),
5857 (arg
->locate
.size
.constant
, Pmode
)),
5858 BLOCK_OP_CALL_PARM
);
5862 arg
->save_area
= gen_reg_rtx (save_mode
);
5863 emit_move_insn (arg
->save_area
, stack_area
);
5869 /* If this isn't going to be placed on both the stack and in registers,
5870 set up the register and number of words. */
5871 if (! arg
->pass_on_stack
)
5873 if (flags
& ECF_SIBCALL
)
5874 reg
= arg
->tail_call_reg
;
5877 partial
= arg
->partial
;
5880 /* Being passed entirely in a register. We shouldn't be called in
5882 gcc_assert (reg
== 0 || partial
!= 0);
5884 /* If this arg needs special alignment, don't load the registers
5886 if (arg
->n_aligned_regs
!= 0)
5889 /* If this is being passed partially in a register, we can't evaluate
5890 it directly into its stack slot. Otherwise, we can. */
5891 if (arg
->value
== 0)
5893 /* stack_arg_under_construction is nonzero if a function argument is
5894 being evaluated directly into the outgoing argument list and
5895 expand_call must take special action to preserve the argument list
5896 if it is called recursively.
5898 For scalar function arguments stack_usage_map is sufficient to
5899 determine which stack slots must be saved and restored. Scalar
5900 arguments in general have pass_on_stack == 0.
5902 If this argument is initialized by a function which takes the
5903 address of the argument (a C++ constructor or a C function
5904 returning a BLKmode structure), then stack_usage_map is
5905 insufficient and expand_call must push the stack around the
5906 function call. Such arguments have pass_on_stack == 1.
5908 Note that it is always safe to set stack_arg_under_construction,
5909 but this generates suboptimal code if set when not needed. */
5911 if (arg
->pass_on_stack
)
5912 stack_arg_under_construction
++;
5914 arg
->value
= expand_expr (pval
,
5916 || TYPE_MODE (TREE_TYPE (pval
)) != arg
->mode
)
5917 ? NULL_RTX
: arg
->stack
,
5918 VOIDmode
, EXPAND_STACK_PARM
);
5920 /* If we are promoting object (or for any other reason) the mode
5921 doesn't agree, convert the mode. */
5923 if (arg
->mode
!= TYPE_MODE (TREE_TYPE (pval
)))
5924 arg
->value
= convert_modes (arg
->mode
, TYPE_MODE (TREE_TYPE (pval
)),
5925 arg
->value
, arg
->unsignedp
);
5927 if (arg
->pass_on_stack
)
5928 stack_arg_under_construction
--;
5931 /* Check for overlap with already clobbered argument area. */
5932 if ((flags
& ECF_SIBCALL
)
5933 && MEM_P (arg
->value
)
5934 && mem_might_overlap_already_clobbered_arg_p (XEXP (arg
->value
, 0),
5935 arg
->locate
.size
.constant
))
5936 sibcall_failure
= 1;
5938 /* Don't allow anything left on stack from computation
5939 of argument to alloca. */
5940 if (flags
& ECF_MAY_BE_ALLOCA
)
5941 do_pending_stack_adjust ();
5943 if (arg
->value
== arg
->stack
)
5944 /* If the value is already in the stack slot, we are done. */
5946 else if (arg
->mode
!= BLKmode
)
5948 unsigned int parm_align
;
5950 /* Argument is a scalar, not entirely passed in registers.
5951 (If part is passed in registers, arg->partial says how much
5952 and emit_push_insn will take care of putting it there.)
5954 Push it, and if its size is less than the
5955 amount of space allocated to it,
5956 also bump stack pointer by the additional space.
5957 Note that in C the default argument promotions
5958 will prevent such mismatches. */
5960 poly_int64 size
= (TYPE_EMPTY_P (TREE_TYPE (pval
))
5961 ? 0 : GET_MODE_SIZE (arg
->mode
));
5963 /* Compute how much space the push instruction will push.
5964 On many machines, pushing a byte will advance the stack
5965 pointer by a halfword. */
5966 #ifdef PUSH_ROUNDING
5967 size
= PUSH_ROUNDING (size
);
5971 /* Compute how much space the argument should get:
5972 round up to a multiple of the alignment for arguments. */
5973 if (targetm
.calls
.function_arg_padding (arg
->mode
, TREE_TYPE (pval
))
5975 /* At the moment we don't (need to) support ABIs for which the
5976 padding isn't known at compile time. In principle it should
5977 be easy to add though. */
5978 used
= force_align_up (size
, PARM_BOUNDARY
/ BITS_PER_UNIT
);
5980 /* Compute the alignment of the pushed argument. */
5981 parm_align
= arg
->locate
.boundary
;
5982 if (targetm
.calls
.function_arg_padding (arg
->mode
, TREE_TYPE (pval
))
5985 poly_int64 pad
= used
- size
;
5986 unsigned int pad_align
= known_alignment (pad
) * BITS_PER_UNIT
;
5988 parm_align
= MIN (parm_align
, pad_align
);
5991 /* This isn't already where we want it on the stack, so put it there.
5992 This can either be done with push or copy insns. */
5993 if (maybe_ne (used
, 0)
5994 && !emit_push_insn (arg
->value
, arg
->mode
, TREE_TYPE (pval
),
5995 NULL_RTX
, parm_align
, partial
, reg
, used
- size
,
5996 argblock
, ARGS_SIZE_RTX (arg
->locate
.offset
),
5997 reg_parm_stack_space
,
5998 ARGS_SIZE_RTX (arg
->locate
.alignment_pad
), true))
5999 sibcall_failure
= 1;
6001 /* Unless this is a partially-in-register argument, the argument is now
6004 arg
->value
= arg
->stack
;
6008 /* BLKmode, at least partly to be pushed. */
6010 unsigned int parm_align
;
6014 /* Pushing a nonscalar.
6015 If part is passed in registers, PARTIAL says how much
6016 and emit_push_insn will take care of putting it there. */
6018 /* Round its size up to a multiple
6019 of the allocation unit for arguments. */
6021 if (arg
->locate
.size
.var
!= 0)
6024 size_rtx
= ARGS_SIZE_RTX (arg
->locate
.size
);
6028 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
6029 for BLKmode is careful to avoid it. */
6030 excess
= (arg
->locate
.size
.constant
6031 - arg_int_size_in_bytes (TREE_TYPE (pval
))
6033 size_rtx
= expand_expr (arg_size_in_bytes (TREE_TYPE (pval
)),
6034 NULL_RTX
, TYPE_MODE (sizetype
),
6038 parm_align
= arg
->locate
.boundary
;
6040 /* When an argument is padded down, the block is aligned to
6041 PARM_BOUNDARY, but the actual argument isn't. */
6042 if (targetm
.calls
.function_arg_padding (arg
->mode
, TREE_TYPE (pval
))
6045 if (arg
->locate
.size
.var
)
6046 parm_align
= BITS_PER_UNIT
;
6049 unsigned int excess_align
6050 = known_alignment (excess
) * BITS_PER_UNIT
;
6051 if (excess_align
!= 0)
6052 parm_align
= MIN (parm_align
, excess_align
);
6056 if ((flags
& ECF_SIBCALL
) && MEM_P (arg
->value
))
6058 /* emit_push_insn might not work properly if arg->value and
6059 argblock + arg->locate.offset areas overlap. */
6063 if (strip_offset (XEXP (x
, 0), &i
)
6064 == crtl
->args
.internal_arg_pointer
)
6066 /* arg.locate doesn't contain the pretend_args_size offset,
6067 it's part of argblock. Ensure we don't count it in I. */
6068 if (STACK_GROWS_DOWNWARD
)
6069 i
-= crtl
->args
.pretend_args_size
;
6071 i
+= crtl
->args
.pretend_args_size
;
6073 /* expand_call should ensure this. */
6074 gcc_assert (!arg
->locate
.offset
.var
6075 && arg
->locate
.size
.var
== 0);
6076 poly_int64 size_val
= rtx_to_poly_int64 (size_rtx
);
6078 if (known_eq (arg
->locate
.offset
.constant
, i
))
6080 /* Even though they appear to be at the same location,
6081 if part of the outgoing argument is in registers,
6082 they aren't really at the same location. Check for
6083 this by making sure that the incoming size is the
6084 same as the outgoing size. */
6085 if (maybe_ne (arg
->locate
.size
.constant
, size_val
))
6086 sibcall_failure
= 1;
6088 else if (maybe_in_range_p (arg
->locate
.offset
.constant
,
6090 sibcall_failure
= 1;
6091 /* Use arg->locate.size.constant instead of size_rtx
6092 because we only care about the part of the argument
6094 else if (maybe_in_range_p (i
, arg
->locate
.offset
.constant
,
6095 arg
->locate
.size
.constant
))
6096 sibcall_failure
= 1;
6100 if (!CONST_INT_P (size_rtx
) || INTVAL (size_rtx
) != 0)
6101 emit_push_insn (arg
->value
, arg
->mode
, TREE_TYPE (pval
), size_rtx
,
6102 parm_align
, partial
, reg
, excess
, argblock
,
6103 ARGS_SIZE_RTX (arg
->locate
.offset
),
6104 reg_parm_stack_space
,
6105 ARGS_SIZE_RTX (arg
->locate
.alignment_pad
), false);
6107 /* Unless this is a partially-in-register argument, the argument is now
6110 ??? Unlike the case above, in which we want the actual
6111 address of the data, so that we can load it directly into a
6112 register, here we want the address of the stack slot, so that
6113 it's properly aligned for word-by-word copying or something
6114 like that. It's not clear that this is always correct. */
6116 arg
->value
= arg
->stack_slot
;
6119 if (arg
->reg
&& GET_CODE (arg
->reg
) == PARALLEL
)
6121 tree type
= TREE_TYPE (arg
->tree_value
);
6123 = emit_group_load_into_temps (arg
->reg
, arg
->value
, type
,
6124 int_size_in_bytes (type
));
6127 /* Mark all slots this store used. */
6128 if (ACCUMULATE_OUTGOING_ARGS
&& !(flags
& ECF_SIBCALL
)
6129 && argblock
&& ! variable_size
&& arg
->stack
)
6130 mark_stack_region_used (lower_bound
, upper_bound
);
6132 /* Once we have pushed something, pops can't safely
6133 be deferred during the rest of the arguments. */
6136 /* Free any temporary slots made in processing this argument. */
6139 return sibcall_failure
;
6142 /* Nonzero if we do not know how to pass ARG solely in registers. */
6145 must_pass_in_stack_var_size (const function_arg_info
&arg
)
6150 /* If the type has variable size... */
6151 if (!poly_int_tree_p (TYPE_SIZE (arg
.type
)))
6154 /* If the type is marked as addressable (it is required
6155 to be constructed into the stack)... */
6156 if (TREE_ADDRESSABLE (arg
.type
))
6162 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
6163 takes trailing padding of a structure into account. */
6164 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
6167 must_pass_in_stack_var_size_or_pad (const function_arg_info
&arg
)
6172 /* If the type has variable size... */
6173 if (TREE_CODE (TYPE_SIZE (arg
.type
)) != INTEGER_CST
)
6176 /* If the type is marked as addressable (it is required
6177 to be constructed into the stack)... */
6178 if (TREE_ADDRESSABLE (arg
.type
))
6181 if (TYPE_EMPTY_P (arg
.type
))
6184 /* If the padding and mode of the type is such that a copy into
6185 a register would put it into the wrong part of the register. */
6186 if (arg
.mode
== BLKmode
6187 && int_size_in_bytes (arg
.type
) % (PARM_BOUNDARY
/ BITS_PER_UNIT
)
6188 && (targetm
.calls
.function_arg_padding (arg
.mode
, arg
.type
)
6189 == (BYTES_BIG_ENDIAN
? PAD_UPWARD
: PAD_DOWNWARD
)))
6195 /* Return true if TYPE must be passed on the stack when passed to
6196 the "..." arguments of a function. */
6199 must_pass_va_arg_in_stack (tree type
)
6201 function_arg_info
arg (type
, /*named=*/false);
6202 return targetm
.calls
.must_pass_in_stack (arg
);
6205 /* Return true if FIELD is the C++17 empty base field that should
6206 be ignored for ABI calling convention decisions in order to
6207 maintain ABI compatibility between C++14 and earlier, which doesn't
6208 add this FIELD to classes with empty bases, and C++17 and later
6212 cxx17_empty_base_field_p (const_tree field
)
6214 return (DECL_FIELD_ABI_IGNORED (field
)
6215 && DECL_ARTIFICIAL (field
)
6216 && RECORD_OR_UNION_TYPE_P (TREE_TYPE (field
))
6217 && !lookup_attribute ("no_unique_address", DECL_ATTRIBUTES (field
)));
6220 /* Tell the garbage collector about GTY markers in this source file. */
6221 #include "gt-calls.h"