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 built-in function
1563 that expects a nul-terminated string argument. Returns true if
1564 a warning has been issued.*/
1567 maybe_warn_nonstring_arg (tree fndecl
, tree exp
)
1569 if (!fndecl
|| !fndecl_built_in_p (fndecl
, BUILT_IN_NORMAL
))
1572 if (TREE_NO_WARNING (exp
) || !warn_stringop_overread
)
1575 /* Avoid clearly invalid calls (more checking done below). */
1576 unsigned nargs
= call_expr_nargs (exp
);
1580 /* The bound argument to a bounded string function like strncpy. */
1581 tree bound
= NULL_TREE
;
1583 /* The longest known or possible string argument to one of the comparison
1584 functions. If the length is less than the bound it is used instead.
1585 Since the length is only used for warning and not for code generation
1586 disable strict mode in the calls to get_range_strlen below. */
1587 tree maxlen
= NULL_TREE
;
1589 /* It's safe to call "bounded" string functions with a non-string
1590 argument since the functions provide an explicit bound for this
1591 purpose. The exception is strncat where the bound may refer to
1592 either the destination or the source. */
1593 int fncode
= DECL_FUNCTION_CODE (fndecl
);
1596 case BUILT_IN_STRCMP
:
1597 case BUILT_IN_STRNCMP
:
1598 case BUILT_IN_STRNCASECMP
:
1600 /* For these, if one argument refers to one or more of a set
1601 of string constants or arrays of known size, determine
1602 the range of their known or possible lengths and use it
1603 conservatively as the bound for the unbounded function,
1604 and to adjust the range of the bound of the bounded ones. */
1605 for (unsigned argno
= 0;
1606 argno
< MIN (nargs
, 2)
1607 && !(maxlen
&& TREE_CODE (maxlen
) == INTEGER_CST
); argno
++)
1609 tree arg
= CALL_EXPR_ARG (exp
, argno
);
1610 if (!get_attr_nonstring_decl (arg
))
1612 c_strlen_data lendata
= { };
1613 /* Set MAXBOUND to an arbitrary non-null non-integer
1614 node as a request to have it set to the length of
1615 the longest string in a PHI. */
1616 lendata
.maxbound
= arg
;
1617 get_range_strlen (arg
, &lendata
, /* eltsize = */ 1);
1618 maxlen
= lendata
.maxbound
;
1624 case BUILT_IN_STRNCAT
:
1625 case BUILT_IN_STPNCPY
:
1626 case BUILT_IN_STRNCPY
:
1628 bound
= CALL_EXPR_ARG (exp
, 2);
1631 case BUILT_IN_STRNDUP
:
1633 bound
= CALL_EXPR_ARG (exp
, 1);
1636 case BUILT_IN_STRNLEN
:
1638 tree arg
= CALL_EXPR_ARG (exp
, 0);
1639 if (!get_attr_nonstring_decl (arg
))
1641 c_strlen_data lendata
= { };
1642 /* Set MAXBOUND to an arbitrary non-null non-integer
1643 node as a request to have it set to the length of
1644 the longest string in a PHI. */
1645 lendata
.maxbound
= arg
;
1646 get_range_strlen (arg
, &lendata
, /* eltsize = */ 1);
1647 maxlen
= lendata
.maxbound
;
1650 bound
= CALL_EXPR_ARG (exp
, 1);
1658 /* Determine the range of the bound argument (if specified). */
1659 tree bndrng
[2] = { NULL_TREE
, NULL_TREE
};
1663 get_size_range (bound
, bndrng
);
1666 location_t loc
= EXPR_LOCATION (exp
);
1670 /* Diagnose excessive bound prior to the adjustment below and
1671 regardless of attribute nonstring. */
1672 tree maxobjsize
= max_object_size ();
1673 if (tree_int_cst_lt (maxobjsize
, bndrng
[0]))
1675 bool warned
= false;
1676 if (tree_int_cst_equal (bndrng
[0], bndrng
[1]))
1677 warned
= warning_at (loc
, OPT_Wstringop_overread
,
1678 "%K%qD specified bound %E "
1679 "exceeds maximum object size %E",
1680 exp
, fndecl
, bndrng
[0], maxobjsize
);
1682 warned
= warning_at (loc
, OPT_Wstringop_overread
,
1683 "%K%qD specified bound [%E, %E] "
1684 "exceeds maximum object size %E",
1685 exp
, fndecl
, bndrng
[0], bndrng
[1],
1688 TREE_NO_WARNING (exp
) = true;
1694 if (maxlen
&& !integer_all_onesp (maxlen
))
1696 /* Add one for the nul. */
1697 maxlen
= const_binop (PLUS_EXPR
, TREE_TYPE (maxlen
), maxlen
,
1702 /* Conservatively use the upper bound of the lengths for
1703 both the lower and the upper bound of the operation. */
1706 bound
= void_type_node
;
1710 /* Replace the bound on the operation with the upper bound
1711 of the length of the string if the latter is smaller. */
1712 if (tree_int_cst_lt (maxlen
, bndrng
[0]))
1714 else if (tree_int_cst_lt (maxlen
, bndrng
[1]))
1719 bool any_arg_warned
= false;
1720 /* Iterate over the built-in function's formal arguments and check
1721 each const char* against the actual argument. If the actual
1722 argument is declared attribute non-string issue a warning unless
1723 the argument's maximum length is bounded. */
1724 function_args_iterator it
;
1725 function_args_iter_init (&it
, TREE_TYPE (fndecl
));
1727 for (unsigned argno
= 0; ; ++argno
, function_args_iter_next (&it
))
1729 /* Avoid iterating past the declared argument in a call
1730 to function declared without a prototype. */
1734 tree argtype
= function_args_iter_cond (&it
);
1738 if (TREE_CODE (argtype
) != POINTER_TYPE
)
1741 argtype
= TREE_TYPE (argtype
);
1743 if (TREE_CODE (argtype
) != INTEGER_TYPE
1744 || !TYPE_READONLY (argtype
))
1747 argtype
= TYPE_MAIN_VARIANT (argtype
);
1748 if (argtype
!= char_type_node
)
1751 tree callarg
= CALL_EXPR_ARG (exp
, argno
);
1752 if (TREE_CODE (callarg
) == ADDR_EXPR
)
1753 callarg
= TREE_OPERAND (callarg
, 0);
1755 /* See if the destination is declared with attribute "nonstring". */
1756 tree decl
= get_attr_nonstring_decl (callarg
);
1760 /* The maximum number of array elements accessed. */
1761 offset_int wibnd
= 0;
1763 if (argno
&& fncode
== BUILT_IN_STRNCAT
)
1765 /* See if the bound in strncat is derived from the length
1766 of the strlen of the destination (as it's expected to be).
1767 If so, reset BOUND and FNCODE to trigger a warning. */
1768 tree dstarg
= CALL_EXPR_ARG (exp
, 0);
1769 if (is_strlen_related_p (dstarg
, bound
))
1771 /* The bound applies to the destination, not to the source,
1772 so reset these to trigger a warning without mentioning
1778 /* Use the upper bound of the range for strncat. */
1779 wibnd
= wi::to_offset (bndrng
[1]);
1782 /* Use the lower bound of the range for functions other than
1784 wibnd
= wi::to_offset (bndrng
[0]);
1786 /* Determine the size of the argument array if it is one. */
1787 offset_int asize
= wibnd
;
1788 bool known_size
= false;
1789 tree type
= TREE_TYPE (decl
);
1791 /* Determine the array size. For arrays of unknown bound and
1792 pointers reset BOUND to trigger the appropriate warning. */
1793 if (TREE_CODE (type
) == ARRAY_TYPE
)
1795 if (tree arrbnd
= TYPE_DOMAIN (type
))
1797 if ((arrbnd
= TYPE_MAX_VALUE (arrbnd
)))
1799 asize
= wi::to_offset (arrbnd
) + 1;
1803 else if (bound
== void_type_node
)
1806 else if (bound
== void_type_node
)
1809 /* In a call to strncat with a bound in a range whose lower but
1810 not upper bound is less than the array size, reset ASIZE to
1811 be the same as the bound and the other variable to trigger
1812 the apprpriate warning below. */
1813 if (fncode
== BUILT_IN_STRNCAT
1814 && bndrng
[0] != bndrng
[1]
1815 && wi::ltu_p (wi::to_offset (bndrng
[0]), asize
)
1817 || wi::ltu_p (asize
, wibnd
)))
1824 bool warned
= false;
1826 auto_diagnostic_group d
;
1827 if (wi::ltu_p (asize
, wibnd
))
1829 if (bndrng
[0] == bndrng
[1])
1830 warned
= warning_at (loc
, OPT_Wstringop_overread
,
1831 "%qD argument %i declared attribute "
1832 "%<nonstring%> is smaller than the specified "
1834 fndecl
, argno
+ 1, wibnd
.to_uhwi ());
1835 else if (wi::ltu_p (asize
, wi::to_offset (bndrng
[0])))
1836 warned
= warning_at (loc
, OPT_Wstringop_overread
,
1837 "%qD argument %i declared attribute "
1838 "%<nonstring%> is smaller than "
1839 "the specified bound [%E, %E]",
1840 fndecl
, argno
+ 1, bndrng
[0], bndrng
[1]);
1842 warned
= warning_at (loc
, OPT_Wstringop_overread
,
1843 "%qD argument %i declared attribute "
1844 "%<nonstring%> may be smaller than "
1845 "the specified bound [%E, %E]",
1846 fndecl
, argno
+ 1, bndrng
[0], bndrng
[1]);
1848 else if (fncode
== BUILT_IN_STRNCAT
)
1849 ; /* Avoid warning for calls to strncat() when the bound
1850 is equal to the size of the non-string argument. */
1852 warned
= warning_at (loc
, OPT_Wstringop_overread
,
1853 "%qD argument %i declared attribute %<nonstring%>",
1858 inform (DECL_SOURCE_LOCATION (decl
),
1859 "argument %qD declared here", decl
);
1860 any_arg_warned
= true;
1865 TREE_NO_WARNING (exp
) = true;
1867 return any_arg_warned
;
1870 /* Issue an error if CALL_EXPR was flagged as requiring
1871 tall-call optimization. */
1874 maybe_complain_about_tail_call (tree call_expr
, const char *reason
)
1876 gcc_assert (TREE_CODE (call_expr
) == CALL_EXPR
);
1877 if (!CALL_EXPR_MUST_TAIL_CALL (call_expr
))
1880 error_at (EXPR_LOCATION (call_expr
), "cannot tail-call: %s", reason
);
1883 /* Returns the type of the argument ARGNO to function with type FNTYPE
1884 or null when the typoe cannot be determined or no such argument exists. */
1887 fntype_argno_type (tree fntype
, unsigned argno
)
1889 if (!prototype_p (fntype
))
1893 function_args_iterator it
;
1894 FOREACH_FUNCTION_ARGS (fntype
, argtype
, it
)
1901 /* Helper to append the "rdwr" attribute specification described
1902 by ACCESS to the array ATTRSTR with size STRSIZE. Used in
1906 append_attrname (const std::pair
<int, attr_access
> &access
,
1907 char *attrstr
, size_t strsize
)
1909 /* Append the relevant attribute to the string. This (deliberately)
1910 appends the attribute pointer operand even when none was specified. */
1911 size_t len
= strlen (attrstr
);
1913 const char* const atname
1914 = (access
.second
.mode
== access_read_only
1916 : (access
.second
.mode
== access_write_only
1918 : (access
.second
.mode
== access_read_write
1919 ? "read_write" : "none")));
1921 const char *sep
= len
? ", " : "";
1923 if (access
.second
.sizarg
== UINT_MAX
)
1924 snprintf (attrstr
+ len
, strsize
- len
,
1925 "%s%s (%i)", sep
, atname
,
1926 access
.second
.ptrarg
+ 1);
1928 snprintf (attrstr
+ len
, strsize
- len
,
1929 "%s%s (%i, %i)", sep
, atname
,
1930 access
.second
.ptrarg
+ 1, access
.second
.sizarg
+ 1);
1933 /* Iterate over attribute access read-only, read-write, and write-only
1934 arguments and diagnose past-the-end accesses and related problems
1935 in the function call EXP. */
1938 maybe_warn_rdwr_sizes (rdwr_map
*rwm
, tree fndecl
, tree fntype
, tree exp
)
1940 auto_diagnostic_group adg
;
1942 /* A string describing the attributes that the warnings issued by this
1943 function apply to. Used to print one informational note per function
1944 call, rather than one per warning. That reduces clutter. */
1948 for (rdwr_map::iterator it
= rwm
->begin (); it
!= rwm
->end (); ++it
)
1950 std::pair
<int, attr_access
> access
= *it
;
1952 /* Get the function call arguments corresponding to the attribute's
1953 positional arguments. When both arguments have been specified
1954 there will be two entries in *RWM, one for each. They are
1955 cross-referenced by their respective argument numbers in
1956 ACCESS.PTRARG and ACCESS.SIZARG. */
1957 const int ptridx
= access
.second
.ptrarg
;
1958 const int sizidx
= access
.second
.sizarg
;
1960 gcc_assert (ptridx
!= -1);
1961 gcc_assert (access
.first
== ptridx
|| access
.first
== sizidx
);
1963 /* The pointer is set to null for the entry corresponding to
1964 the size argument. Skip it. It's handled when the entry
1965 corresponding to the pointer argument comes up. */
1966 if (!access
.second
.ptr
)
1969 tree argtype
= fntype_argno_type (fntype
, ptridx
);
1970 argtype
= TREE_TYPE (argtype
);
1975 /* If only the pointer attribute operand was specified
1976 and not size, set SIZE to the size of one element of
1977 the pointed to type to detect smaller objects (null
1978 pointers are diagnosed in this case only if
1979 the pointer is also declared with attribute nonnull. */
1980 size
= size_one_node
;
1983 size
= rwm
->get (sizidx
)->size
;
1985 tree ptr
= access
.second
.ptr
;
1986 tree sizrng
[2] = { size_zero_node
, build_all_ones_cst (sizetype
) };
1987 if (get_size_range (size
, sizrng
, true)
1988 && tree_int_cst_sgn (sizrng
[0]) < 0
1989 && tree_int_cst_sgn (sizrng
[1]) < 0)
1991 /* Warn about negative sizes. */
1992 bool warned
= false;
1993 location_t loc
= EXPR_LOCATION (exp
);
1994 if (tree_int_cst_equal (sizrng
[0], sizrng
[1]))
1995 warned
= warning_at (loc
, OPT_Wstringop_overflow_
,
1996 "%Kargument %i value %E is negative",
1997 exp
, sizidx
+ 1, size
);
1999 warned
= warning_at (loc
, OPT_Wstringop_overflow_
,
2000 "%Kargument %i range [%E, %E] is negative",
2001 exp
, sizidx
+ 1, sizrng
[0], sizrng
[1]);
2004 append_attrname (access
, attrstr
, sizeof attrstr
);
2005 /* Avoid warning again for the same attribute. */
2010 if (tree_int_cst_sgn (sizrng
[0]) >= 0)
2012 if (COMPLETE_TYPE_P (argtype
))
2014 /* Multiple SIZE by the size of the type the pointer
2015 argument points to. If it's incomplete the size
2018 if (tree argsize
= TYPE_SIZE_UNIT (argtype
))
2019 if (TREE_CODE (argsize
) == INTEGER_CST
)
2021 const int prec
= TYPE_PRECISION (sizetype
);
2022 wide_int minsize
= wi::to_wide (sizrng
[0], prec
);
2023 minsize
*= wi::to_wide (argsize
, prec
);
2024 size
= wide_int_to_tree (sizetype
, minsize
);
2032 && integer_zerop (ptr
)
2033 && tree_int_cst_sgn (sizrng
[0]) > 0)
2035 /* Warn about null pointers with positive sizes. This is
2036 different from also declaring the pointer argument with
2037 attribute nonnull when the function accepts null pointers
2038 only when the corresponding size is zero. */
2039 bool warned
= false;
2040 const location_t loc
= EXPR_LOC_OR_LOC (ptr
, EXPR_LOCATION (exp
));
2041 if (tree_int_cst_equal (sizrng
[0], sizrng
[1]))
2042 warned
= warning_at (loc
, OPT_Wnonnull
,
2043 "%Kargument %i is null but the corresponding "
2044 "size argument %i value is %E",
2045 exp
, ptridx
+ 1, sizidx
+ 1, size
);
2047 warned
= warning_at (loc
, OPT_Wnonnull
,
2048 "%Kargument %i is null but the corresponding "
2049 "size argument %i range is [%E, %E]",
2050 exp
, ptridx
+ 1, sizidx
+ 1,
2051 sizrng
[0], sizrng
[1]);
2054 append_attrname (access
, attrstr
, sizeof attrstr
);
2055 /* Avoid warning again for the same attribute. */
2060 tree objsize
= compute_objsize (ptr
, 0);
2063 if (access
.second
.mode
== access_write_only
)
2065 /* For a write-only argument there is no source. */
2066 srcsize
= NULL_TREE
;
2070 /* For read-only and read-write attributes also set the source
2073 if (access
.second
.mode
== access_read_only
2074 || access
.second
.mode
== access_none
)
2076 /* For a read-only attribute there is no destination so
2077 clear OBJSIZE. This emits "reading N bytes" kind of
2078 diagnostics instead of the "writing N bytes" kind,
2079 unless MODE is none. */
2080 objsize
= NULL_TREE
;
2084 /* Clear the no-warning bit in case it was set in a prior
2085 iteration so that accesses via different arguments are
2087 TREE_NO_WARNING (exp
) = false;
2088 check_access (exp
, size
, /*maxread=*/ NULL_TREE
, srcsize
, objsize
,
2089 access
.second
.mode
);
2091 if (TREE_NO_WARNING (exp
))
2092 /* If check_access issued a warning above, append the relevant
2093 attribute to the string. */
2094 append_attrname (access
, attrstr
, sizeof attrstr
);
2101 inform (DECL_SOURCE_LOCATION (fndecl
),
2102 "in a call to function %qD declared with attribute %qs",
2105 inform (EXPR_LOCATION (fndecl
),
2106 "in a call with type %qT and attribute %qs",
2109 /* Set the bit in case if was cleared and not set above. */
2110 TREE_NO_WARNING (exp
) = true;
2113 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
2116 NUM_ACTUALS is the total number of parameters.
2118 N_NAMED_ARGS is the total number of named arguments.
2120 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
2123 FNDECL is the tree code for the target of this call (if known)
2125 ARGS_SO_FAR holds state needed by the target to know where to place
2128 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
2129 for arguments which are passed in registers.
2131 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
2132 and may be modified by this routine.
2134 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
2135 flags which may be modified by this routine.
2137 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
2138 that requires allocation of stack space.
2140 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
2141 the thunked-to function. */
2144 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED
,
2145 struct arg_data
*args
,
2146 struct args_size
*args_size
,
2147 int n_named_args ATTRIBUTE_UNUSED
,
2148 tree exp
, tree struct_value_addr_value
,
2149 tree fndecl
, tree fntype
,
2150 cumulative_args_t args_so_far
,
2151 int reg_parm_stack_space
,
2152 rtx
*old_stack_level
,
2153 poly_int64_pod
*old_pending_adj
,
2154 int *must_preallocate
, int *ecf_flags
,
2155 bool *may_tailcall
, bool call_from_thunk_p
)
2157 CUMULATIVE_ARGS
*args_so_far_pnt
= get_cumulative_args (args_so_far
);
2158 location_t loc
= EXPR_LOCATION (exp
);
2160 /* Count arg position in order args appear. */
2165 args_size
->constant
= 0;
2168 bitmap_obstack_initialize (NULL
);
2170 /* In this loop, we consider args in the order they are written.
2171 We fill up ARGS from the back. */
2173 i
= num_actuals
- 1;
2176 call_expr_arg_iterator iter
;
2178 bitmap slots
= NULL
;
2180 if (struct_value_addr_value
)
2182 args
[j
].tree_value
= struct_value_addr_value
;
2186 FOR_EACH_CALL_EXPR_ARG (arg
, iter
, exp
)
2188 tree argtype
= TREE_TYPE (arg
);
2190 if (targetm
.calls
.split_complex_arg
2192 && TREE_CODE (argtype
) == COMPLEX_TYPE
2193 && targetm
.calls
.split_complex_arg (argtype
))
2195 tree subtype
= TREE_TYPE (argtype
);
2196 args
[j
].tree_value
= build1 (REALPART_EXPR
, subtype
, arg
);
2198 args
[j
].tree_value
= build1 (IMAGPART_EXPR
, subtype
, arg
);
2201 args
[j
].tree_value
= arg
;
2207 BITMAP_FREE (slots
);
2210 bitmap_obstack_release (NULL
);
2212 /* Extract attribute alloc_size from the type of the called expression
2213 (which could be a function or a function pointer) and if set, store
2214 the indices of the corresponding arguments in ALLOC_IDX, and then
2215 the actual argument(s) at those indices in ALLOC_ARGS. */
2216 int alloc_idx
[2] = { -1, -1 };
2217 if (tree alloc_size
= lookup_attribute ("alloc_size",
2218 TYPE_ATTRIBUTES (fntype
)))
2220 tree args
= TREE_VALUE (alloc_size
);
2221 alloc_idx
[0] = TREE_INT_CST_LOW (TREE_VALUE (args
)) - 1;
2222 if (TREE_CHAIN (args
))
2223 alloc_idx
[1] = TREE_INT_CST_LOW (TREE_VALUE (TREE_CHAIN (args
))) - 1;
2226 /* Array for up to the two attribute alloc_size arguments. */
2227 tree alloc_args
[] = { NULL_TREE
, NULL_TREE
};
2229 /* Map of attribute accewss specifications for function arguments. */
2231 init_attr_rdwr_indices (&rdwr_idx
, fntype
);
2233 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
2234 for (argpos
= 0; argpos
< num_actuals
; i
--, argpos
++)
2236 tree type
= TREE_TYPE (args
[i
].tree_value
);
2239 /* Replace erroneous argument with constant zero. */
2240 if (type
== error_mark_node
|| !COMPLETE_TYPE_P (type
))
2241 args
[i
].tree_value
= integer_zero_node
, type
= integer_type_node
;
2243 /* If TYPE is a transparent union or record, pass things the way
2244 we would pass the first field of the union or record. We have
2245 already verified that the modes are the same. */
2246 if (RECORD_OR_UNION_TYPE_P (type
) && TYPE_TRANSPARENT_AGGR (type
))
2247 type
= TREE_TYPE (first_field (type
));
2249 /* Decide where to pass this arg.
2251 args[i].reg is nonzero if all or part is passed in registers.
2253 args[i].partial is nonzero if part but not all is passed in registers,
2254 and the exact value says how many bytes are passed in registers.
2256 args[i].pass_on_stack is nonzero if the argument must at least be
2257 computed on the stack. It may then be loaded back into registers
2258 if args[i].reg is nonzero.
2260 These decisions are driven by the FUNCTION_... macros and must agree
2261 with those made by function.c. */
2263 /* See if this argument should be passed by invisible reference. */
2264 function_arg_info
arg (type
, argpos
< n_named_args
);
2265 if (pass_by_reference (args_so_far_pnt
, arg
))
2268 tree base
= NULL_TREE
;
2270 callee_copies
= reference_callee_copied (args_so_far_pnt
, arg
);
2272 /* If we're compiling a thunk, pass through invisible references
2273 instead of making a copy. */
2274 if (call_from_thunk_p
2276 && !TREE_ADDRESSABLE (type
)
2277 && (base
= get_base_address (args
[i
].tree_value
))
2278 && TREE_CODE (base
) != SSA_NAME
2279 && (!DECL_P (base
) || MEM_P (DECL_RTL (base
)))))
2281 /* We may have turned the parameter value into an SSA name.
2282 Go back to the original parameter so we can take the
2284 if (TREE_CODE (args
[i
].tree_value
) == SSA_NAME
)
2286 gcc_assert (SSA_NAME_IS_DEFAULT_DEF (args
[i
].tree_value
));
2287 args
[i
].tree_value
= SSA_NAME_VAR (args
[i
].tree_value
);
2288 gcc_assert (TREE_CODE (args
[i
].tree_value
) == PARM_DECL
);
2290 /* Argument setup code may have copied the value to register. We
2291 revert that optimization now because the tail call code must
2292 use the original location. */
2293 if (TREE_CODE (args
[i
].tree_value
) == PARM_DECL
2294 && !MEM_P (DECL_RTL (args
[i
].tree_value
))
2295 && DECL_INCOMING_RTL (args
[i
].tree_value
)
2296 && MEM_P (DECL_INCOMING_RTL (args
[i
].tree_value
)))
2297 set_decl_rtl (args
[i
].tree_value
,
2298 DECL_INCOMING_RTL (args
[i
].tree_value
));
2300 mark_addressable (args
[i
].tree_value
);
2302 /* We can't use sibcalls if a callee-copied argument is
2303 stored in the current function's frame. */
2304 if (!call_from_thunk_p
&& DECL_P (base
) && !TREE_STATIC (base
))
2306 *may_tailcall
= false;
2307 maybe_complain_about_tail_call (exp
,
2308 "a callee-copied argument is"
2309 " stored in the current"
2310 " function's frame");
2313 args
[i
].tree_value
= build_fold_addr_expr_loc (loc
,
2314 args
[i
].tree_value
);
2315 type
= TREE_TYPE (args
[i
].tree_value
);
2317 if (*ecf_flags
& ECF_CONST
)
2318 *ecf_flags
&= ~(ECF_CONST
| ECF_LOOPING_CONST_OR_PURE
);
2322 /* We make a copy of the object and pass the address to the
2323 function being called. */
2326 if (!COMPLETE_TYPE_P (type
)
2327 || TREE_CODE (TYPE_SIZE_UNIT (type
)) != INTEGER_CST
2328 || (flag_stack_check
== GENERIC_STACK_CHECK
2329 && compare_tree_int (TYPE_SIZE_UNIT (type
),
2330 STACK_CHECK_MAX_VAR_SIZE
) > 0))
2332 /* This is a variable-sized object. Make space on the stack
2334 rtx size_rtx
= expr_size (args
[i
].tree_value
);
2336 if (*old_stack_level
== 0)
2338 emit_stack_save (SAVE_BLOCK
, old_stack_level
);
2339 *old_pending_adj
= pending_stack_adjust
;
2340 pending_stack_adjust
= 0;
2343 /* We can pass TRUE as the 4th argument because we just
2344 saved the stack pointer and will restore it right after
2346 copy
= allocate_dynamic_stack_space (size_rtx
,
2349 max_int_size_in_bytes
2352 copy
= gen_rtx_MEM (BLKmode
, copy
);
2353 set_mem_attributes (copy
, type
, 1);
2356 copy
= assign_temp (type
, 1, 0);
2358 store_expr (args
[i
].tree_value
, copy
, 0, false, false);
2360 /* Just change the const function to pure and then let
2361 the next test clear the pure based on
2363 if (*ecf_flags
& ECF_CONST
)
2365 *ecf_flags
&= ~ECF_CONST
;
2366 *ecf_flags
|= ECF_PURE
;
2369 if (!callee_copies
&& *ecf_flags
& ECF_PURE
)
2370 *ecf_flags
&= ~(ECF_PURE
| ECF_LOOPING_CONST_OR_PURE
);
2373 = build_fold_addr_expr_loc (loc
, make_tree (type
, copy
));
2374 type
= TREE_TYPE (args
[i
].tree_value
);
2375 *may_tailcall
= false;
2376 maybe_complain_about_tail_call (exp
,
2377 "argument must be passed"
2380 arg
.pass_by_reference
= true;
2383 unsignedp
= TYPE_UNSIGNED (type
);
2386 = promote_function_mode (type
, TYPE_MODE (type
), &unsignedp
,
2387 fndecl
? TREE_TYPE (fndecl
) : fntype
, 0);
2389 args
[i
].unsignedp
= unsignedp
;
2390 args
[i
].mode
= arg
.mode
;
2392 targetm
.calls
.warn_parameter_passing_abi (args_so_far
, type
);
2394 args
[i
].reg
= targetm
.calls
.function_arg (args_so_far
, arg
);
2396 if (args
[i
].reg
&& CONST_INT_P (args
[i
].reg
))
2399 /* If this is a sibling call and the machine has register windows, the
2400 register window has to be unwinded before calling the routine, so
2401 arguments have to go into the incoming registers. */
2402 if (targetm
.calls
.function_incoming_arg
!= targetm
.calls
.function_arg
)
2403 args
[i
].tail_call_reg
2404 = targetm
.calls
.function_incoming_arg (args_so_far
, arg
);
2406 args
[i
].tail_call_reg
= args
[i
].reg
;
2409 args
[i
].partial
= targetm
.calls
.arg_partial_bytes (args_so_far
, arg
);
2411 args
[i
].pass_on_stack
= targetm
.calls
.must_pass_in_stack (arg
);
2413 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
2414 it means that we are to pass this arg in the register(s) designated
2415 by the PARALLEL, but also to pass it in the stack. */
2416 if (args
[i
].reg
&& GET_CODE (args
[i
].reg
) == PARALLEL
2417 && XEXP (XVECEXP (args
[i
].reg
, 0, 0), 0) == 0)
2418 args
[i
].pass_on_stack
= 1;
2420 /* If this is an addressable type, we must preallocate the stack
2421 since we must evaluate the object into its final location.
2423 If this is to be passed in both registers and the stack, it is simpler
2425 if (TREE_ADDRESSABLE (type
)
2426 || (args
[i
].pass_on_stack
&& args
[i
].reg
!= 0))
2427 *must_preallocate
= 1;
2429 /* Compute the stack-size of this argument. */
2430 if (args
[i
].reg
== 0 || args
[i
].partial
!= 0
2431 || reg_parm_stack_space
> 0
2432 || args
[i
].pass_on_stack
)
2433 locate_and_pad_parm (arg
.mode
, type
,
2434 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2439 reg_parm_stack_space
,
2440 args
[i
].pass_on_stack
? 0 : args
[i
].partial
,
2441 fndecl
, args_size
, &args
[i
].locate
);
2442 #ifdef BLOCK_REG_PADDING
2444 /* The argument is passed entirely in registers. See at which
2445 end it should be padded. */
2446 args
[i
].locate
.where_pad
=
2447 BLOCK_REG_PADDING (arg
.mode
, type
,
2448 int_size_in_bytes (type
) <= UNITS_PER_WORD
);
2451 /* Update ARGS_SIZE, the total stack space for args so far. */
2453 args_size
->constant
+= args
[i
].locate
.size
.constant
;
2454 if (args
[i
].locate
.size
.var
)
2455 ADD_PARM_SIZE (*args_size
, args
[i
].locate
.size
.var
);
2457 /* Increment ARGS_SO_FAR, which has info about which arg-registers
2458 have been used, etc. */
2460 /* ??? Traditionally we've passed TYPE_MODE here, instead of the
2461 promoted_mode used for function_arg above. However, the
2462 corresponding handling of incoming arguments in function.c
2463 does pass the promoted mode. */
2464 arg
.mode
= TYPE_MODE (type
);
2465 targetm
.calls
.function_arg_advance (args_so_far
, arg
);
2467 /* Store argument values for functions decorated with attribute
2469 if (argpos
== alloc_idx
[0])
2470 alloc_args
[0] = args
[i
].tree_value
;
2471 else if (argpos
== alloc_idx
[1])
2472 alloc_args
[1] = args
[i
].tree_value
;
2474 /* Save the actual argument that corresponds to the access attribute
2475 operand for later processing. */
2476 if (attr_access
*access
= rdwr_idx
.get (argpos
))
2478 if (POINTER_TYPE_P (type
))
2480 access
->ptr
= args
[i
].tree_value
;
2481 gcc_assert (access
->size
== NULL_TREE
);
2485 access
->size
= args
[i
].tree_value
;
2486 gcc_assert (access
->ptr
== NULL_TREE
);
2493 /* Check the arguments of functions decorated with attribute
2495 maybe_warn_alloc_args_overflow (fndecl
, exp
, alloc_args
, alloc_idx
);
2498 /* Detect passing non-string arguments to functions expecting
2499 nul-terminated strings. */
2500 maybe_warn_nonstring_arg (fndecl
, exp
);
2502 /* Check attribute access arguments. */
2503 maybe_warn_rdwr_sizes (&rdwr_idx
, fndecl
, fntype
, exp
);
2506 /* Update ARGS_SIZE to contain the total size for the argument block.
2507 Return the original constant component of the argument block's size.
2509 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
2510 for arguments passed in registers. */
2513 compute_argument_block_size (int reg_parm_stack_space
,
2514 struct args_size
*args_size
,
2515 tree fndecl ATTRIBUTE_UNUSED
,
2516 tree fntype ATTRIBUTE_UNUSED
,
2517 int preferred_stack_boundary ATTRIBUTE_UNUSED
)
2519 poly_int64 unadjusted_args_size
= args_size
->constant
;
2521 /* For accumulate outgoing args mode we don't need to align, since the frame
2522 will be already aligned. Align to STACK_BOUNDARY in order to prevent
2523 backends from generating misaligned frame sizes. */
2524 if (ACCUMULATE_OUTGOING_ARGS
&& preferred_stack_boundary
> STACK_BOUNDARY
)
2525 preferred_stack_boundary
= STACK_BOUNDARY
;
2527 /* Compute the actual size of the argument block required. The variable
2528 and constant sizes must be combined, the size may have to be rounded,
2529 and there may be a minimum required size. */
2533 args_size
->var
= ARGS_SIZE_TREE (*args_size
);
2534 args_size
->constant
= 0;
2536 preferred_stack_boundary
/= BITS_PER_UNIT
;
2537 if (preferred_stack_boundary
> 1)
2539 /* We don't handle this case yet. To handle it correctly we have
2540 to add the delta, round and subtract the delta.
2541 Currently no machine description requires this support. */
2542 gcc_assert (multiple_p (stack_pointer_delta
,
2543 preferred_stack_boundary
));
2544 args_size
->var
= round_up (args_size
->var
, preferred_stack_boundary
);
2547 if (reg_parm_stack_space
> 0)
2550 = size_binop (MAX_EXPR
, args_size
->var
,
2551 ssize_int (reg_parm_stack_space
));
2553 /* The area corresponding to register parameters is not to count in
2554 the size of the block we need. So make the adjustment. */
2555 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl
? fntype
: TREE_TYPE (fndecl
))))
2557 = size_binop (MINUS_EXPR
, args_size
->var
,
2558 ssize_int (reg_parm_stack_space
));
2563 preferred_stack_boundary
/= BITS_PER_UNIT
;
2564 if (preferred_stack_boundary
< 1)
2565 preferred_stack_boundary
= 1;
2566 args_size
->constant
= (aligned_upper_bound (args_size
->constant
2567 + stack_pointer_delta
,
2568 preferred_stack_boundary
)
2569 - stack_pointer_delta
);
2571 args_size
->constant
= upper_bound (args_size
->constant
,
2572 reg_parm_stack_space
);
2574 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl
? fntype
: TREE_TYPE (fndecl
))))
2575 args_size
->constant
-= reg_parm_stack_space
;
2577 return unadjusted_args_size
;
2580 /* Precompute parameters as needed for a function call.
2582 FLAGS is mask of ECF_* constants.
2584 NUM_ACTUALS is the number of arguments.
2586 ARGS is an array containing information for each argument; this
2587 routine fills in the INITIAL_VALUE and VALUE fields for each
2588 precomputed argument. */
2591 precompute_arguments (int num_actuals
, struct arg_data
*args
)
2595 /* If this is a libcall, then precompute all arguments so that we do not
2596 get extraneous instructions emitted as part of the libcall sequence. */
2598 /* If we preallocated the stack space, and some arguments must be passed
2599 on the stack, then we must precompute any parameter which contains a
2600 function call which will store arguments on the stack.
2601 Otherwise, evaluating the parameter may clobber previous parameters
2602 which have already been stored into the stack. (we have code to avoid
2603 such case by saving the outgoing stack arguments, but it results in
2605 if (!ACCUMULATE_OUTGOING_ARGS
)
2608 for (i
= 0; i
< num_actuals
; i
++)
2613 if (TREE_CODE (args
[i
].tree_value
) != CALL_EXPR
)
2616 /* If this is an addressable type, we cannot pre-evaluate it. */
2617 type
= TREE_TYPE (args
[i
].tree_value
);
2618 gcc_assert (!TREE_ADDRESSABLE (type
));
2620 args
[i
].initial_value
= args
[i
].value
2621 = expand_normal (args
[i
].tree_value
);
2623 mode
= TYPE_MODE (type
);
2624 if (mode
!= args
[i
].mode
)
2626 int unsignedp
= args
[i
].unsignedp
;
2628 = convert_modes (args
[i
].mode
, mode
,
2629 args
[i
].value
, args
[i
].unsignedp
);
2631 /* CSE will replace this only if it contains args[i].value
2632 pseudo, so convert it down to the declared mode using
2634 if (REG_P (args
[i
].value
)
2635 && GET_MODE_CLASS (args
[i
].mode
) == MODE_INT
2636 && promote_mode (type
, mode
, &unsignedp
) != args
[i
].mode
)
2638 args
[i
].initial_value
2639 = gen_lowpart_SUBREG (mode
, args
[i
].value
);
2640 SUBREG_PROMOTED_VAR_P (args
[i
].initial_value
) = 1;
2641 SUBREG_PROMOTED_SET (args
[i
].initial_value
, args
[i
].unsignedp
);
2647 /* Given the current state of MUST_PREALLOCATE and information about
2648 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
2649 compute and return the final value for MUST_PREALLOCATE. */
2652 finalize_must_preallocate (int must_preallocate
, int num_actuals
,
2653 struct arg_data
*args
, struct args_size
*args_size
)
2655 /* See if we have or want to preallocate stack space.
2657 If we would have to push a partially-in-regs parm
2658 before other stack parms, preallocate stack space instead.
2660 If the size of some parm is not a multiple of the required stack
2661 alignment, we must preallocate.
2663 If the total size of arguments that would otherwise create a copy in
2664 a temporary (such as a CALL) is more than half the total argument list
2665 size, preallocation is faster.
2667 Another reason to preallocate is if we have a machine (like the m88k)
2668 where stack alignment is required to be maintained between every
2669 pair of insns, not just when the call is made. However, we assume here
2670 that such machines either do not have push insns (and hence preallocation
2671 would occur anyway) or the problem is taken care of with
2674 if (! must_preallocate
)
2676 int partial_seen
= 0;
2677 poly_int64 copy_to_evaluate_size
= 0;
2680 for (i
= 0; i
< num_actuals
&& ! must_preallocate
; i
++)
2682 if (args
[i
].partial
> 0 && ! args
[i
].pass_on_stack
)
2684 else if (partial_seen
&& args
[i
].reg
== 0)
2685 must_preallocate
= 1;
2687 if (TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)) == BLKmode
2688 && (TREE_CODE (args
[i
].tree_value
) == CALL_EXPR
2689 || TREE_CODE (args
[i
].tree_value
) == TARGET_EXPR
2690 || TREE_CODE (args
[i
].tree_value
) == COND_EXPR
2691 || TREE_ADDRESSABLE (TREE_TYPE (args
[i
].tree_value
))))
2692 copy_to_evaluate_size
2693 += int_size_in_bytes (TREE_TYPE (args
[i
].tree_value
));
2696 if (maybe_ne (args_size
->constant
, 0)
2697 && maybe_ge (copy_to_evaluate_size
* 2, args_size
->constant
))
2698 must_preallocate
= 1;
2700 return must_preallocate
;
2703 /* If we preallocated stack space, compute the address of each argument
2704 and store it into the ARGS array.
2706 We need not ensure it is a valid memory address here; it will be
2707 validized when it is used.
2709 ARGBLOCK is an rtx for the address of the outgoing arguments. */
2712 compute_argument_addresses (struct arg_data
*args
, rtx argblock
, int num_actuals
)
2716 rtx arg_reg
= argblock
;
2718 poly_int64 arg_offset
= 0;
2720 if (GET_CODE (argblock
) == PLUS
)
2722 arg_reg
= XEXP (argblock
, 0);
2723 arg_offset
= rtx_to_poly_int64 (XEXP (argblock
, 1));
2726 for (i
= 0; i
< num_actuals
; i
++)
2728 rtx offset
= ARGS_SIZE_RTX (args
[i
].locate
.offset
);
2729 rtx slot_offset
= ARGS_SIZE_RTX (args
[i
].locate
.slot_offset
);
2731 unsigned int align
, boundary
;
2732 poly_uint64 units_on_stack
= 0;
2733 machine_mode partial_mode
= VOIDmode
;
2735 /* Skip this parm if it will not be passed on the stack. */
2736 if (! args
[i
].pass_on_stack
2738 && args
[i
].partial
== 0)
2741 if (TYPE_EMPTY_P (TREE_TYPE (args
[i
].tree_value
)))
2744 addr
= simplify_gen_binary (PLUS
, Pmode
, arg_reg
, offset
);
2745 addr
= plus_constant (Pmode
, addr
, arg_offset
);
2747 if (args
[i
].partial
!= 0)
2749 /* Only part of the parameter is being passed on the stack.
2750 Generate a simple memory reference of the correct size. */
2751 units_on_stack
= args
[i
].locate
.size
.constant
;
2752 poly_uint64 bits_on_stack
= units_on_stack
* BITS_PER_UNIT
;
2753 partial_mode
= int_mode_for_size (bits_on_stack
, 1).else_blk ();
2754 args
[i
].stack
= gen_rtx_MEM (partial_mode
, addr
);
2755 set_mem_size (args
[i
].stack
, units_on_stack
);
2759 args
[i
].stack
= gen_rtx_MEM (args
[i
].mode
, addr
);
2760 set_mem_attributes (args
[i
].stack
,
2761 TREE_TYPE (args
[i
].tree_value
), 1);
2763 align
= BITS_PER_UNIT
;
2764 boundary
= args
[i
].locate
.boundary
;
2765 poly_int64 offset_val
;
2766 if (args
[i
].locate
.where_pad
!= PAD_DOWNWARD
)
2768 else if (poly_int_rtx_p (offset
, &offset_val
))
2770 align
= least_bit_hwi (boundary
);
2771 unsigned int offset_align
2772 = known_alignment (offset_val
) * BITS_PER_UNIT
;
2773 if (offset_align
!= 0)
2774 align
= MIN (align
, offset_align
);
2776 set_mem_align (args
[i
].stack
, align
);
2778 addr
= simplify_gen_binary (PLUS
, Pmode
, arg_reg
, slot_offset
);
2779 addr
= plus_constant (Pmode
, addr
, arg_offset
);
2781 if (args
[i
].partial
!= 0)
2783 /* Only part of the parameter is being passed on the stack.
2784 Generate a simple memory reference of the correct size.
2786 args
[i
].stack_slot
= gen_rtx_MEM (partial_mode
, addr
);
2787 set_mem_size (args
[i
].stack_slot
, units_on_stack
);
2791 args
[i
].stack_slot
= gen_rtx_MEM (args
[i
].mode
, addr
);
2792 set_mem_attributes (args
[i
].stack_slot
,
2793 TREE_TYPE (args
[i
].tree_value
), 1);
2795 set_mem_align (args
[i
].stack_slot
, args
[i
].locate
.boundary
);
2797 /* Function incoming arguments may overlap with sibling call
2798 outgoing arguments and we cannot allow reordering of reads
2799 from function arguments with stores to outgoing arguments
2800 of sibling calls. */
2801 set_mem_alias_set (args
[i
].stack
, 0);
2802 set_mem_alias_set (args
[i
].stack_slot
, 0);
2807 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
2808 in a call instruction.
2810 FNDECL is the tree node for the target function. For an indirect call
2811 FNDECL will be NULL_TREE.
2813 ADDR is the operand 0 of CALL_EXPR for this call. */
2816 rtx_for_function_call (tree fndecl
, tree addr
)
2820 /* Get the function to call, in the form of RTL. */
2823 if (!TREE_USED (fndecl
) && fndecl
!= current_function_decl
)
2824 TREE_USED (fndecl
) = 1;
2826 /* Get a SYMBOL_REF rtx for the function address. */
2827 funexp
= XEXP (DECL_RTL (fndecl
), 0);
2830 /* Generate an rtx (probably a pseudo-register) for the address. */
2833 funexp
= expand_normal (addr
);
2834 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
2839 /* Return the static chain for this function, if any. */
2842 rtx_for_static_chain (const_tree fndecl_or_type
, bool incoming_p
)
2844 if (DECL_P (fndecl_or_type
) && !DECL_STATIC_CHAIN (fndecl_or_type
))
2847 return targetm
.calls
.static_chain (fndecl_or_type
, incoming_p
);
2850 /* Internal state for internal_arg_pointer_based_exp and its helpers. */
2853 /* Last insn that has been scanned by internal_arg_pointer_based_exp_scan,
2854 or NULL_RTX if none has been scanned yet. */
2855 rtx_insn
*scan_start
;
2856 /* Vector indexed by REGNO - FIRST_PSEUDO_REGISTER, recording if a pseudo is
2857 based on crtl->args.internal_arg_pointer. The element is NULL_RTX if the
2858 pseudo isn't based on it, a CONST_INT offset if the pseudo is based on it
2859 with fixed offset, or PC if this is with variable or unknown offset. */
2861 } internal_arg_pointer_exp_state
;
2863 static rtx
internal_arg_pointer_based_exp (const_rtx
, bool);
2865 /* Helper function for internal_arg_pointer_based_exp. Scan insns in
2866 the tail call sequence, starting with first insn that hasn't been
2867 scanned yet, and note for each pseudo on the LHS whether it is based
2868 on crtl->args.internal_arg_pointer or not, and what offset from that
2869 that pointer it has. */
2872 internal_arg_pointer_based_exp_scan (void)
2874 rtx_insn
*insn
, *scan_start
= internal_arg_pointer_exp_state
.scan_start
;
2876 if (scan_start
== NULL_RTX
)
2877 insn
= get_insns ();
2879 insn
= NEXT_INSN (scan_start
);
2883 rtx set
= single_set (insn
);
2884 if (set
&& REG_P (SET_DEST (set
)) && !HARD_REGISTER_P (SET_DEST (set
)))
2887 unsigned int idx
= REGNO (SET_DEST (set
)) - FIRST_PSEUDO_REGISTER
;
2888 /* Punt on pseudos set multiple times. */
2889 if (idx
< internal_arg_pointer_exp_state
.cache
.length ()
2890 && (internal_arg_pointer_exp_state
.cache
[idx
]
2894 val
= internal_arg_pointer_based_exp (SET_SRC (set
), false);
2895 if (val
!= NULL_RTX
)
2897 if (idx
>= internal_arg_pointer_exp_state
.cache
.length ())
2898 internal_arg_pointer_exp_state
.cache
2899 .safe_grow_cleared (idx
+ 1, true);
2900 internal_arg_pointer_exp_state
.cache
[idx
] = val
;
2903 if (NEXT_INSN (insn
) == NULL_RTX
)
2905 insn
= NEXT_INSN (insn
);
2908 internal_arg_pointer_exp_state
.scan_start
= scan_start
;
2911 /* Compute whether RTL is based on crtl->args.internal_arg_pointer. Return
2912 NULL_RTX if RTL isn't based on it, a CONST_INT offset if RTL is based on
2913 it with fixed offset, or PC if this is with variable or unknown offset.
2914 TOPLEVEL is true if the function is invoked at the topmost level. */
2917 internal_arg_pointer_based_exp (const_rtx rtl
, bool toplevel
)
2919 if (CONSTANT_P (rtl
))
2922 if (rtl
== crtl
->args
.internal_arg_pointer
)
2925 if (REG_P (rtl
) && HARD_REGISTER_P (rtl
))
2929 if (GET_CODE (rtl
) == PLUS
&& poly_int_rtx_p (XEXP (rtl
, 1), &offset
))
2931 rtx val
= internal_arg_pointer_based_exp (XEXP (rtl
, 0), toplevel
);
2932 if (val
== NULL_RTX
|| val
== pc_rtx
)
2934 return plus_constant (Pmode
, val
, offset
);
2937 /* When called at the topmost level, scan pseudo assignments in between the
2938 last scanned instruction in the tail call sequence and the latest insn
2939 in that sequence. */
2941 internal_arg_pointer_based_exp_scan ();
2945 unsigned int idx
= REGNO (rtl
) - FIRST_PSEUDO_REGISTER
;
2946 if (idx
< internal_arg_pointer_exp_state
.cache
.length ())
2947 return internal_arg_pointer_exp_state
.cache
[idx
];
2952 subrtx_iterator::array_type array
;
2953 FOR_EACH_SUBRTX (iter
, array
, rtl
, NONCONST
)
2955 const_rtx x
= *iter
;
2956 if (REG_P (x
) && internal_arg_pointer_based_exp (x
, false) != NULL_RTX
)
2959 iter
.skip_subrtxes ();
2965 /* Return true if SIZE bytes starting from address ADDR might overlap an
2966 already-clobbered argument area. This function is used to determine
2967 if we should give up a sibcall. */
2970 mem_might_overlap_already_clobbered_arg_p (rtx addr
, poly_uint64 size
)
2973 unsigned HOST_WIDE_INT start
, end
;
2976 if (bitmap_empty_p (stored_args_map
)
2977 && stored_args_watermark
== HOST_WIDE_INT_M1U
)
2979 val
= internal_arg_pointer_based_exp (addr
, true);
2980 if (val
== NULL_RTX
)
2982 else if (!poly_int_rtx_p (val
, &i
))
2985 if (known_eq (size
, 0U))
2988 if (STACK_GROWS_DOWNWARD
)
2989 i
-= crtl
->args
.pretend_args_size
;
2991 i
+= crtl
->args
.pretend_args_size
;
2993 if (ARGS_GROW_DOWNWARD
)
2996 /* We can ignore any references to the function's pretend args,
2997 which at this point would manifest as negative values of I. */
2998 if (known_le (i
, 0) && known_le (size
, poly_uint64 (-i
)))
3001 start
= maybe_lt (i
, 0) ? 0 : constant_lower_bound (i
);
3002 if (!(i
+ size
).is_constant (&end
))
3003 end
= HOST_WIDE_INT_M1U
;
3005 if (end
> stored_args_watermark
)
3008 end
= MIN (end
, SBITMAP_SIZE (stored_args_map
));
3009 for (unsigned HOST_WIDE_INT k
= start
; k
< end
; ++k
)
3010 if (bitmap_bit_p (stored_args_map
, k
))
3016 /* Do the register loads required for any wholly-register parms or any
3017 parms which are passed both on the stack and in a register. Their
3018 expressions were already evaluated.
3020 Mark all register-parms as living through the call, putting these USE
3021 insns in the CALL_INSN_FUNCTION_USAGE field.
3023 When IS_SIBCALL, perform the check_sibcall_argument_overlap
3024 checking, setting *SIBCALL_FAILURE if appropriate. */
3027 load_register_parameters (struct arg_data
*args
, int num_actuals
,
3028 rtx
*call_fusage
, int flags
, int is_sibcall
,
3029 int *sibcall_failure
)
3033 for (i
= 0; i
< num_actuals
; i
++)
3035 rtx reg
= ((flags
& ECF_SIBCALL
)
3036 ? args
[i
].tail_call_reg
: args
[i
].reg
);
3039 int partial
= args
[i
].partial
;
3041 poly_int64 size
= 0;
3042 HOST_WIDE_INT const_size
= 0;
3043 rtx_insn
*before_arg
= get_last_insn ();
3044 tree type
= TREE_TYPE (args
[i
].tree_value
);
3045 if (RECORD_OR_UNION_TYPE_P (type
) && TYPE_TRANSPARENT_AGGR (type
))
3046 type
= TREE_TYPE (first_field (type
));
3047 /* Set non-negative if we must move a word at a time, even if
3048 just one word (e.g, partial == 4 && mode == DFmode). Set
3049 to -1 if we just use a normal move insn. This value can be
3050 zero if the argument is a zero size structure. */
3052 if (GET_CODE (reg
) == PARALLEL
)
3056 gcc_assert (partial
% UNITS_PER_WORD
== 0);
3057 nregs
= partial
/ UNITS_PER_WORD
;
3059 else if (TYPE_MODE (type
) == BLKmode
)
3061 /* Variable-sized parameters should be described by a
3062 PARALLEL instead. */
3063 const_size
= int_size_in_bytes (type
);
3064 gcc_assert (const_size
>= 0);
3065 nregs
= (const_size
+ (UNITS_PER_WORD
- 1)) / UNITS_PER_WORD
;
3069 size
= GET_MODE_SIZE (args
[i
].mode
);
3071 /* Handle calls that pass values in multiple non-contiguous
3072 locations. The Irix 6 ABI has examples of this. */
3074 if (GET_CODE (reg
) == PARALLEL
)
3075 emit_group_move (reg
, args
[i
].parallel_value
);
3077 /* If simple case, just do move. If normal partial, store_one_arg
3078 has already loaded the register for us. In all other cases,
3079 load the register(s) from memory. */
3081 else if (nregs
== -1)
3083 emit_move_insn (reg
, args
[i
].value
);
3084 #ifdef BLOCK_REG_PADDING
3085 /* Handle case where we have a value that needs shifting
3086 up to the msb. eg. a QImode value and we're padding
3087 upward on a BYTES_BIG_ENDIAN machine. */
3088 if (args
[i
].locate
.where_pad
3089 == (BYTES_BIG_ENDIAN
? PAD_UPWARD
: PAD_DOWNWARD
))
3091 gcc_checking_assert (ordered_p (size
, UNITS_PER_WORD
));
3092 if (maybe_lt (size
, UNITS_PER_WORD
))
3096 = (UNITS_PER_WORD
- size
) * BITS_PER_UNIT
;
3098 /* Assigning REG here rather than a temp makes
3099 CALL_FUSAGE report the whole reg as used.
3100 Strictly speaking, the call only uses SIZE
3101 bytes at the msb end, but it doesn't seem worth
3102 generating rtl to say that. */
3103 reg
= gen_rtx_REG (word_mode
, REGNO (reg
));
3104 x
= expand_shift (LSHIFT_EXPR
, word_mode
,
3105 reg
, shift
, reg
, 1);
3107 emit_move_insn (reg
, x
);
3113 /* If we have pre-computed the values to put in the registers in
3114 the case of non-aligned structures, copy them in now. */
3116 else if (args
[i
].n_aligned_regs
!= 0)
3117 for (j
= 0; j
< args
[i
].n_aligned_regs
; j
++)
3118 emit_move_insn (gen_rtx_REG (word_mode
, REGNO (reg
) + j
),
3119 args
[i
].aligned_regs
[j
]);
3121 else if (partial
== 0 || args
[i
].pass_on_stack
)
3123 /* SIZE and CONST_SIZE are 0 for partial arguments and
3124 the size of a BLKmode type otherwise. */
3125 gcc_checking_assert (known_eq (size
, const_size
));
3126 rtx mem
= validize_mem (copy_rtx (args
[i
].value
));
3128 /* Check for overlap with already clobbered argument area,
3129 providing that this has non-zero size. */
3132 && (mem_might_overlap_already_clobbered_arg_p
3133 (XEXP (args
[i
].value
, 0), const_size
)))
3134 *sibcall_failure
= 1;
3136 if (const_size
% UNITS_PER_WORD
== 0
3137 || MEM_ALIGN (mem
) % BITS_PER_WORD
== 0)
3138 move_block_to_reg (REGNO (reg
), mem
, nregs
, args
[i
].mode
);
3142 move_block_to_reg (REGNO (reg
), mem
, nregs
- 1,
3144 rtx dest
= gen_rtx_REG (word_mode
, REGNO (reg
) + nregs
- 1);
3145 unsigned int bitoff
= (nregs
- 1) * BITS_PER_WORD
;
3146 unsigned int bitsize
= const_size
* BITS_PER_UNIT
- bitoff
;
3147 rtx x
= extract_bit_field (mem
, bitsize
, bitoff
, 1, dest
,
3148 word_mode
, word_mode
, false,
3150 if (BYTES_BIG_ENDIAN
)
3151 x
= expand_shift (LSHIFT_EXPR
, word_mode
, x
,
3152 BITS_PER_WORD
- bitsize
, dest
, 1);
3154 emit_move_insn (dest
, x
);
3157 /* Handle a BLKmode that needs shifting. */
3158 if (nregs
== 1 && const_size
< UNITS_PER_WORD
3159 #ifdef BLOCK_REG_PADDING
3160 && args
[i
].locate
.where_pad
== PAD_DOWNWARD
3166 rtx dest
= gen_rtx_REG (word_mode
, REGNO (reg
));
3167 int shift
= (UNITS_PER_WORD
- const_size
) * BITS_PER_UNIT
;
3168 enum tree_code dir
= (BYTES_BIG_ENDIAN
3169 ? RSHIFT_EXPR
: LSHIFT_EXPR
);
3172 x
= expand_shift (dir
, word_mode
, dest
, shift
, dest
, 1);
3174 emit_move_insn (dest
, x
);
3178 /* When a parameter is a block, and perhaps in other cases, it is
3179 possible that it did a load from an argument slot that was
3180 already clobbered. */
3182 && check_sibcall_argument_overlap (before_arg
, &args
[i
], 0))
3183 *sibcall_failure
= 1;
3185 /* Handle calls that pass values in multiple non-contiguous
3186 locations. The Irix 6 ABI has examples of this. */
3187 if (GET_CODE (reg
) == PARALLEL
)
3188 use_group_regs (call_fusage
, reg
);
3189 else if (nregs
== -1)
3190 use_reg_mode (call_fusage
, reg
, TYPE_MODE (type
));
3192 use_regs (call_fusage
, REGNO (reg
), nregs
);
3197 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
3198 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
3199 bytes, then we would need to push some additional bytes to pad the
3200 arguments. So, we try to compute an adjust to the stack pointer for an
3201 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
3202 bytes. Then, when the arguments are pushed the stack will be perfectly
3205 Return true if this optimization is possible, storing the adjustment
3206 in ADJUSTMENT_OUT and setting ARGS_SIZE->CONSTANT to the number of
3207 bytes that should be popped after the call. */
3210 combine_pending_stack_adjustment_and_call (poly_int64_pod
*adjustment_out
,
3211 poly_int64 unadjusted_args_size
,
3212 struct args_size
*args_size
,
3213 unsigned int preferred_unit_stack_boundary
)
3215 /* The number of bytes to pop so that the stack will be
3216 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
3217 poly_int64 adjustment
;
3218 /* The alignment of the stack after the arguments are pushed, if we
3219 just pushed the arguments without adjust the stack here. */
3220 unsigned HOST_WIDE_INT unadjusted_alignment
;
3222 if (!known_misalignment (stack_pointer_delta
+ unadjusted_args_size
,
3223 preferred_unit_stack_boundary
,
3224 &unadjusted_alignment
))
3227 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
3228 as possible -- leaving just enough left to cancel out the
3229 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
3230 PENDING_STACK_ADJUST is non-negative, and congruent to
3231 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
3233 /* Begin by trying to pop all the bytes. */
3234 unsigned HOST_WIDE_INT tmp_misalignment
;
3235 if (!known_misalignment (pending_stack_adjust
,
3236 preferred_unit_stack_boundary
,
3239 unadjusted_alignment
-= tmp_misalignment
;
3240 adjustment
= pending_stack_adjust
;
3241 /* Push enough additional bytes that the stack will be aligned
3242 after the arguments are pushed. */
3243 if (preferred_unit_stack_boundary
> 1 && unadjusted_alignment
)
3244 adjustment
-= preferred_unit_stack_boundary
- unadjusted_alignment
;
3246 /* We need to know whether the adjusted argument size
3247 (UNADJUSTED_ARGS_SIZE - ADJUSTMENT) constitutes an allocation
3248 or a deallocation. */
3249 if (!ordered_p (adjustment
, unadjusted_args_size
))
3252 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
3253 bytes after the call. The right number is the entire
3254 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
3255 by the arguments in the first place. */
3257 = pending_stack_adjust
- adjustment
+ unadjusted_args_size
;
3259 *adjustment_out
= adjustment
;
3263 /* Scan X expression if it does not dereference any argument slots
3264 we already clobbered by tail call arguments (as noted in stored_args_map
3266 Return nonzero if X expression dereferences such argument slots,
3270 check_sibcall_argument_overlap_1 (rtx x
)
3279 code
= GET_CODE (x
);
3281 /* We need not check the operands of the CALL expression itself. */
3286 return (mem_might_overlap_already_clobbered_arg_p
3287 (XEXP (x
, 0), GET_MODE_SIZE (GET_MODE (x
))));
3289 /* Scan all subexpressions. */
3290 fmt
= GET_RTX_FORMAT (code
);
3291 for (i
= 0; i
< GET_RTX_LENGTH (code
); i
++, fmt
++)
3295 if (check_sibcall_argument_overlap_1 (XEXP (x
, i
)))
3298 else if (*fmt
== 'E')
3300 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
3301 if (check_sibcall_argument_overlap_1 (XVECEXP (x
, i
, j
)))
3308 /* Scan sequence after INSN if it does not dereference any argument slots
3309 we already clobbered by tail call arguments (as noted in stored_args_map
3310 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
3311 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
3312 should be 0). Return nonzero if sequence after INSN dereferences such argument
3313 slots, zero otherwise. */
3316 check_sibcall_argument_overlap (rtx_insn
*insn
, struct arg_data
*arg
,
3317 int mark_stored_args_map
)
3319 poly_uint64 low
, high
;
3320 unsigned HOST_WIDE_INT const_low
, const_high
;
3322 if (insn
== NULL_RTX
)
3323 insn
= get_insns ();
3325 insn
= NEXT_INSN (insn
);
3327 for (; insn
; insn
= NEXT_INSN (insn
))
3329 && check_sibcall_argument_overlap_1 (PATTERN (insn
)))
3332 if (mark_stored_args_map
)
3334 if (ARGS_GROW_DOWNWARD
)
3335 low
= -arg
->locate
.slot_offset
.constant
- arg
->locate
.size
.constant
;
3337 low
= arg
->locate
.slot_offset
.constant
;
3338 high
= low
+ arg
->locate
.size
.constant
;
3340 const_low
= constant_lower_bound (low
);
3341 if (high
.is_constant (&const_high
))
3342 for (unsigned HOST_WIDE_INT i
= const_low
; i
< const_high
; ++i
)
3343 bitmap_set_bit (stored_args_map
, i
);
3345 stored_args_watermark
= MIN (stored_args_watermark
, const_low
);
3347 return insn
!= NULL_RTX
;
3350 /* Given that a function returns a value of mode MODE at the most
3351 significant end of hard register VALUE, shift VALUE left or right
3352 as specified by LEFT_P. Return true if some action was needed. */
3355 shift_return_value (machine_mode mode
, bool left_p
, rtx value
)
3357 gcc_assert (REG_P (value
) && HARD_REGISTER_P (value
));
3358 machine_mode value_mode
= GET_MODE (value
);
3359 poly_int64 shift
= GET_MODE_BITSIZE (value_mode
) - GET_MODE_BITSIZE (mode
);
3361 if (known_eq (shift
, 0))
3364 /* Use ashr rather than lshr for right shifts. This is for the benefit
3365 of the MIPS port, which requires SImode values to be sign-extended
3366 when stored in 64-bit registers. */
3367 if (!force_expand_binop (value_mode
, left_p
? ashl_optab
: ashr_optab
,
3368 value
, gen_int_shift_amount (value_mode
, shift
),
3369 value
, 1, OPTAB_WIDEN
))
3374 /* If X is a likely-spilled register value, copy it to a pseudo
3375 register and return that register. Return X otherwise. */
3378 avoid_likely_spilled_reg (rtx x
)
3383 && HARD_REGISTER_P (x
)
3384 && targetm
.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (x
))))
3386 /* Make sure that we generate a REG rather than a CONCAT.
3387 Moves into CONCATs can need nontrivial instructions,
3388 and the whole point of this function is to avoid
3389 using the hard register directly in such a situation. */
3390 generating_concat_p
= 0;
3391 new_rtx
= gen_reg_rtx (GET_MODE (x
));
3392 generating_concat_p
= 1;
3393 emit_move_insn (new_rtx
, x
);
3399 /* Helper function for expand_call.
3400 Return false is EXP is not implementable as a sibling call. */
3403 can_implement_as_sibling_call_p (tree exp
,
3404 rtx structure_value_addr
,
3406 int reg_parm_stack_space ATTRIBUTE_UNUSED
,
3410 const args_size
&args_size
)
3412 if (!targetm
.have_sibcall_epilogue ())
3414 maybe_complain_about_tail_call
3416 "machine description does not have"
3417 " a sibcall_epilogue instruction pattern");
3421 /* Doing sibling call optimization needs some work, since
3422 structure_value_addr can be allocated on the stack.
3423 It does not seem worth the effort since few optimizable
3424 sibling calls will return a structure. */
3425 if (structure_value_addr
!= NULL_RTX
)
3427 maybe_complain_about_tail_call (exp
, "callee returns a structure");
3431 #ifdef REG_PARM_STACK_SPACE
3432 /* If outgoing reg parm stack space changes, we cannot do sibcall. */
3433 if (OUTGOING_REG_PARM_STACK_SPACE (funtype
)
3434 != OUTGOING_REG_PARM_STACK_SPACE (TREE_TYPE (current_function_decl
))
3435 || (reg_parm_stack_space
!= REG_PARM_STACK_SPACE (current_function_decl
)))
3437 maybe_complain_about_tail_call (exp
,
3438 "inconsistent size of stack space"
3439 " allocated for arguments which are"
3440 " passed in registers");
3445 /* Check whether the target is able to optimize the call
3447 if (!targetm
.function_ok_for_sibcall (fndecl
, exp
))
3449 maybe_complain_about_tail_call (exp
,
3450 "target is not able to optimize the"
3451 " call into a sibling call");
3455 /* Functions that do not return exactly once may not be sibcall
3457 if (flags
& ECF_RETURNS_TWICE
)
3459 maybe_complain_about_tail_call (exp
, "callee returns twice");
3462 if (flags
& ECF_NORETURN
)
3464 maybe_complain_about_tail_call (exp
, "callee does not return");
3468 if (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr
))))
3470 maybe_complain_about_tail_call (exp
, "volatile function type");
3474 /* If the called function is nested in the current one, it might access
3475 some of the caller's arguments, but could clobber them beforehand if
3476 the argument areas are shared. */
3477 if (fndecl
&& decl_function_context (fndecl
) == current_function_decl
)
3479 maybe_complain_about_tail_call (exp
, "nested function");
3483 /* If this function requires more stack slots than the current
3484 function, we cannot change it into a sibling call.
3485 crtl->args.pretend_args_size is not part of the
3486 stack allocated by our caller. */
3487 if (maybe_gt (args_size
.constant
,
3488 crtl
->args
.size
- crtl
->args
.pretend_args_size
))
3490 maybe_complain_about_tail_call (exp
,
3491 "callee required more stack slots"
3492 " than the caller");
3496 /* If the callee pops its own arguments, then it must pop exactly
3497 the same number of arguments as the current function. */
3498 if (maybe_ne (targetm
.calls
.return_pops_args (fndecl
, funtype
,
3499 args_size
.constant
),
3500 targetm
.calls
.return_pops_args (current_function_decl
,
3502 (current_function_decl
),
3505 maybe_complain_about_tail_call (exp
,
3506 "inconsistent number of"
3507 " popped arguments");
3511 if (!lang_hooks
.decls
.ok_for_sibcall (fndecl
))
3513 maybe_complain_about_tail_call (exp
, "frontend does not support"
3518 /* All checks passed. */
3522 /* Update stack alignment when the parameter is passed in the stack
3523 since the outgoing parameter requires extra alignment on the calling
3527 update_stack_alignment_for_call (struct locate_and_pad_arg_data
*locate
)
3529 if (crtl
->stack_alignment_needed
< locate
->boundary
)
3530 crtl
->stack_alignment_needed
= locate
->boundary
;
3531 if (crtl
->preferred_stack_boundary
< locate
->boundary
)
3532 crtl
->preferred_stack_boundary
= locate
->boundary
;
3535 /* Generate all the code for a CALL_EXPR exp
3536 and return an rtx for its value.
3537 Store the value in TARGET (specified as an rtx) if convenient.
3538 If the value is stored in TARGET then TARGET is returned.
3539 If IGNORE is nonzero, then we ignore the value of the function call. */
3542 expand_call (tree exp
, rtx target
, int ignore
)
3544 /* Nonzero if we are currently expanding a call. */
3545 static int currently_expanding_call
= 0;
3547 /* RTX for the function to be called. */
3549 /* Sequence of insns to perform a normal "call". */
3550 rtx_insn
*normal_call_insns
= NULL
;
3551 /* Sequence of insns to perform a tail "call". */
3552 rtx_insn
*tail_call_insns
= NULL
;
3553 /* Data type of the function. */
3555 tree type_arg_types
;
3557 /* Declaration of the function being called,
3558 or 0 if the function is computed (not known by name). */
3560 /* The type of the function being called. */
3562 bool try_tail_call
= CALL_EXPR_TAILCALL (exp
);
3563 bool must_tail_call
= CALL_EXPR_MUST_TAIL_CALL (exp
);
3566 /* Register in which non-BLKmode value will be returned,
3567 or 0 if no value or if value is BLKmode. */
3569 /* Address where we should return a BLKmode value;
3570 0 if value not BLKmode. */
3571 rtx structure_value_addr
= 0;
3572 /* Nonzero if that address is being passed by treating it as
3573 an extra, implicit first parameter. Otherwise,
3574 it is passed by being copied directly into struct_value_rtx. */
3575 int structure_value_addr_parm
= 0;
3576 /* Holds the value of implicit argument for the struct value. */
3577 tree structure_value_addr_value
= NULL_TREE
;
3578 /* Size of aggregate value wanted, or zero if none wanted
3579 or if we are using the non-reentrant PCC calling convention
3580 or expecting the value in registers. */
3581 poly_int64 struct_value_size
= 0;
3582 /* Nonzero if called function returns an aggregate in memory PCC style,
3583 by returning the address of where to find it. */
3584 int pcc_struct_value
= 0;
3585 rtx struct_value
= 0;
3587 /* Number of actual parameters in this call, including struct value addr. */
3589 /* Number of named args. Args after this are anonymous ones
3590 and they must all go on the stack. */
3592 /* Number of complex actual arguments that need to be split. */
3593 int num_complex_actuals
= 0;
3595 /* Vector of information about each argument.
3596 Arguments are numbered in the order they will be pushed,
3597 not the order they are written. */
3598 struct arg_data
*args
;
3600 /* Total size in bytes of all the stack-parms scanned so far. */
3601 struct args_size args_size
;
3602 struct args_size adjusted_args_size
;
3603 /* Size of arguments before any adjustments (such as rounding). */
3604 poly_int64 unadjusted_args_size
;
3605 /* Data on reg parms scanned so far. */
3606 CUMULATIVE_ARGS args_so_far_v
;
3607 cumulative_args_t args_so_far
;
3608 /* Nonzero if a reg parm has been scanned. */
3610 /* Nonzero if this is an indirect function call. */
3612 /* Nonzero if we must avoid push-insns in the args for this call.
3613 If stack space is allocated for register parameters, but not by the
3614 caller, then it is preallocated in the fixed part of the stack frame.
3615 So the entire argument block must then be preallocated (i.e., we
3616 ignore PUSH_ROUNDING in that case). */
3618 int must_preallocate
= !PUSH_ARGS
;
3620 /* Size of the stack reserved for parameter registers. */
3621 int reg_parm_stack_space
= 0;
3623 /* Address of space preallocated for stack parms
3624 (on machines that lack push insns), or 0 if space not preallocated. */
3627 /* Mask of ECF_ and ERF_ flags. */
3629 int return_flags
= 0;
3630 #ifdef REG_PARM_STACK_SPACE
3631 /* Define the boundary of the register parm stack space that needs to be
3633 int low_to_save
, high_to_save
;
3634 rtx save_area
= 0; /* Place that it is saved */
3637 unsigned int initial_highest_arg_in_use
= highest_outgoing_arg_in_use
;
3638 char *initial_stack_usage_map
= stack_usage_map
;
3639 unsigned HOST_WIDE_INT initial_stack_usage_watermark
= stack_usage_watermark
;
3640 char *stack_usage_map_buf
= NULL
;
3642 poly_int64 old_stack_allocated
;
3644 /* State variables to track stack modifications. */
3645 rtx old_stack_level
= 0;
3646 int old_stack_arg_under_construction
= 0;
3647 poly_int64 old_pending_adj
= 0;
3648 int old_inhibit_defer_pop
= inhibit_defer_pop
;
3650 /* Some stack pointer alterations we make are performed via
3651 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
3652 which we then also need to save/restore along the way. */
3653 poly_int64 old_stack_pointer_delta
= 0;
3656 tree addr
= CALL_EXPR_FN (exp
);
3658 /* The alignment of the stack, in bits. */
3659 unsigned HOST_WIDE_INT preferred_stack_boundary
;
3660 /* The alignment of the stack, in bytes. */
3661 unsigned HOST_WIDE_INT preferred_unit_stack_boundary
;
3662 /* The static chain value to use for this call. */
3663 rtx static_chain_value
;
3664 /* See if this is "nothrow" function call. */
3665 if (TREE_NOTHROW (exp
))
3666 flags
|= ECF_NOTHROW
;
3668 /* See if we can find a DECL-node for the actual function, and get the
3669 function attributes (flags) from the function decl or type node. */
3670 fndecl
= get_callee_fndecl (exp
);
3673 fntype
= TREE_TYPE (fndecl
);
3674 flags
|= flags_from_decl_or_type (fndecl
);
3675 return_flags
|= decl_return_flags (fndecl
);
3679 fntype
= TREE_TYPE (TREE_TYPE (addr
));
3680 flags
|= flags_from_decl_or_type (fntype
);
3681 if (CALL_EXPR_BY_DESCRIPTOR (exp
))
3682 flags
|= ECF_BY_DESCRIPTOR
;
3684 rettype
= TREE_TYPE (exp
);
3686 struct_value
= targetm
.calls
.struct_value_rtx (fntype
, 0);
3688 /* Warn if this value is an aggregate type,
3689 regardless of which calling convention we are using for it. */
3690 if (AGGREGATE_TYPE_P (rettype
))
3691 warning (OPT_Waggregate_return
, "function call has aggregate value");
3693 /* If the result of a non looping pure or const function call is
3694 ignored (or void), and none of its arguments are volatile, we can
3695 avoid expanding the call and just evaluate the arguments for
3697 if ((flags
& (ECF_CONST
| ECF_PURE
))
3698 && (!(flags
& ECF_LOOPING_CONST_OR_PURE
))
3699 && (ignore
|| target
== const0_rtx
3700 || TYPE_MODE (rettype
) == VOIDmode
))
3702 bool volatilep
= false;
3704 call_expr_arg_iterator iter
;
3706 FOR_EACH_CALL_EXPR_ARG (arg
, iter
, exp
)
3707 if (TREE_THIS_VOLATILE (arg
))
3715 FOR_EACH_CALL_EXPR_ARG (arg
, iter
, exp
)
3716 expand_expr (arg
, const0_rtx
, VOIDmode
, EXPAND_NORMAL
);
3721 #ifdef REG_PARM_STACK_SPACE
3722 reg_parm_stack_space
= REG_PARM_STACK_SPACE (!fndecl
? fntype
: fndecl
);
3725 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl
? fntype
: TREE_TYPE (fndecl
)))
3726 && reg_parm_stack_space
> 0 && PUSH_ARGS
)
3727 must_preallocate
= 1;
3729 /* Set up a place to return a structure. */
3731 /* Cater to broken compilers. */
3732 if (aggregate_value_p (exp
, fntype
))
3734 /* This call returns a big structure. */
3735 flags
&= ~(ECF_CONST
| ECF_PURE
| ECF_LOOPING_CONST_OR_PURE
);
3737 #ifdef PCC_STATIC_STRUCT_RETURN
3739 pcc_struct_value
= 1;
3741 #else /* not PCC_STATIC_STRUCT_RETURN */
3743 if (!poly_int_tree_p (TYPE_SIZE_UNIT (rettype
), &struct_value_size
))
3744 struct_value_size
= -1;
3746 /* Even if it is semantically safe to use the target as the return
3747 slot, it may be not sufficiently aligned for the return type. */
3748 if (CALL_EXPR_RETURN_SLOT_OPT (exp
)
3751 /* If rettype is addressable, we may not create a temporary.
3752 If target is properly aligned at runtime and the compiler
3753 just doesn't know about it, it will work fine, otherwise it
3755 && (TREE_ADDRESSABLE (rettype
)
3756 || !(MEM_ALIGN (target
) < TYPE_ALIGN (rettype
)
3757 && targetm
.slow_unaligned_access (TYPE_MODE (rettype
),
3758 MEM_ALIGN (target
)))))
3759 structure_value_addr
= XEXP (target
, 0);
3762 /* For variable-sized objects, we must be called with a target
3763 specified. If we were to allocate space on the stack here,
3764 we would have no way of knowing when to free it. */
3765 rtx d
= assign_temp (rettype
, 1, 1);
3766 structure_value_addr
= XEXP (d
, 0);
3770 #endif /* not PCC_STATIC_STRUCT_RETURN */
3773 /* Figure out the amount to which the stack should be aligned. */
3774 preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
3777 struct cgraph_rtl_info
*i
= cgraph_node::rtl_info (fndecl
);
3778 /* Without automatic stack alignment, we can't increase preferred
3779 stack boundary. With automatic stack alignment, it is
3780 unnecessary since unless we can guarantee that all callers will
3781 align the outgoing stack properly, callee has to align its
3784 && i
->preferred_incoming_stack_boundary
3785 && i
->preferred_incoming_stack_boundary
< preferred_stack_boundary
)
3786 preferred_stack_boundary
= i
->preferred_incoming_stack_boundary
;
3789 /* Operand 0 is a pointer-to-function; get the type of the function. */
3790 funtype
= TREE_TYPE (addr
);
3791 gcc_assert (POINTER_TYPE_P (funtype
));
3792 funtype
= TREE_TYPE (funtype
);
3794 /* Count whether there are actual complex arguments that need to be split
3795 into their real and imaginary parts. Munge the type_arg_types
3796 appropriately here as well. */
3797 if (targetm
.calls
.split_complex_arg
)
3799 call_expr_arg_iterator iter
;
3801 FOR_EACH_CALL_EXPR_ARG (arg
, iter
, exp
)
3803 tree type
= TREE_TYPE (arg
);
3804 if (type
&& TREE_CODE (type
) == COMPLEX_TYPE
3805 && targetm
.calls
.split_complex_arg (type
))
3806 num_complex_actuals
++;
3808 type_arg_types
= split_complex_types (TYPE_ARG_TYPES (funtype
));
3811 type_arg_types
= TYPE_ARG_TYPES (funtype
);
3813 if (flags
& ECF_MAY_BE_ALLOCA
)
3814 cfun
->calls_alloca
= 1;
3816 /* If struct_value_rtx is 0, it means pass the address
3817 as if it were an extra parameter. Put the argument expression
3818 in structure_value_addr_value. */
3819 if (structure_value_addr
&& struct_value
== 0)
3821 /* If structure_value_addr is a REG other than
3822 virtual_outgoing_args_rtx, we can use always use it. If it
3823 is not a REG, we must always copy it into a register.
3824 If it is virtual_outgoing_args_rtx, we must copy it to another
3825 register in some cases. */
3826 rtx temp
= (!REG_P (structure_value_addr
)
3827 || (ACCUMULATE_OUTGOING_ARGS
3828 && stack_arg_under_construction
3829 && structure_value_addr
== virtual_outgoing_args_rtx
)
3830 ? copy_addr_to_reg (convert_memory_address
3831 (Pmode
, structure_value_addr
))
3832 : structure_value_addr
);
3834 structure_value_addr_value
=
3835 make_tree (build_pointer_type (TREE_TYPE (funtype
)), temp
);
3836 structure_value_addr_parm
= 1;
3839 /* Count the arguments and set NUM_ACTUALS. */
3841 call_expr_nargs (exp
) + num_complex_actuals
+ structure_value_addr_parm
;
3843 /* Compute number of named args.
3844 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
3846 if (type_arg_types
!= 0)
3848 = (list_length (type_arg_types
)
3849 /* Count the struct value address, if it is passed as a parm. */
3850 + structure_value_addr_parm
);
3852 /* If we know nothing, treat all args as named. */
3853 n_named_args
= num_actuals
;
3855 /* Start updating where the next arg would go.
3857 On some machines (such as the PA) indirect calls have a different
3858 calling convention than normal calls. The fourth argument in
3859 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
3861 INIT_CUMULATIVE_ARGS (args_so_far_v
, funtype
, NULL_RTX
, fndecl
, n_named_args
);
3862 args_so_far
= pack_cumulative_args (&args_so_far_v
);
3864 /* Now possibly adjust the number of named args.
3865 Normally, don't include the last named arg if anonymous args follow.
3866 We do include the last named arg if
3867 targetm.calls.strict_argument_naming() returns nonzero.
3868 (If no anonymous args follow, the result of list_length is actually
3869 one too large. This is harmless.)
3871 If targetm.calls.pretend_outgoing_varargs_named() returns
3872 nonzero, and targetm.calls.strict_argument_naming() returns zero,
3873 this machine will be able to place unnamed args that were passed
3874 in registers into the stack. So treat all args as named. This
3875 allows the insns emitting for a specific argument list to be
3876 independent of the function declaration.
3878 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
3879 we do not have any reliable way to pass unnamed args in
3880 registers, so we must force them into memory. */
3882 if (type_arg_types
!= 0
3883 && targetm
.calls
.strict_argument_naming (args_so_far
))
3885 else if (type_arg_types
!= 0
3886 && ! targetm
.calls
.pretend_outgoing_varargs_named (args_so_far
))
3887 /* Don't include the last named arg. */
3890 /* Treat all args as named. */
3891 n_named_args
= num_actuals
;
3893 /* Make a vector to hold all the information about each arg. */
3894 args
= XCNEWVEC (struct arg_data
, num_actuals
);
3896 /* Build up entries in the ARGS array, compute the size of the
3897 arguments into ARGS_SIZE, etc. */
3898 initialize_argument_information (num_actuals
, args
, &args_size
,
3900 structure_value_addr_value
, fndecl
, fntype
,
3901 args_so_far
, reg_parm_stack_space
,
3902 &old_stack_level
, &old_pending_adj
,
3903 &must_preallocate
, &flags
,
3904 &try_tail_call
, CALL_FROM_THUNK_P (exp
));
3907 must_preallocate
= 1;
3909 /* Now make final decision about preallocating stack space. */
3910 must_preallocate
= finalize_must_preallocate (must_preallocate
,
3914 /* If the structure value address will reference the stack pointer, we
3915 must stabilize it. We don't need to do this if we know that we are
3916 not going to adjust the stack pointer in processing this call. */
3918 if (structure_value_addr
3919 && (reg_mentioned_p (virtual_stack_dynamic_rtx
, structure_value_addr
)
3920 || reg_mentioned_p (virtual_outgoing_args_rtx
,
3921 structure_value_addr
))
3923 || (!ACCUMULATE_OUTGOING_ARGS
3924 && maybe_ne (args_size
.constant
, 0))))
3925 structure_value_addr
= copy_to_reg (structure_value_addr
);
3927 /* Tail calls can make things harder to debug, and we've traditionally
3928 pushed these optimizations into -O2. Don't try if we're already
3929 expanding a call, as that means we're an argument. Don't try if
3930 there's cleanups, as we know there's code to follow the call. */
3931 if (currently_expanding_call
++ != 0
3932 || (!flag_optimize_sibling_calls
&& !CALL_FROM_THUNK_P (exp
))
3934 || dbg_cnt (tail_call
) == false)
3937 /* Workaround buggy C/C++ wrappers around Fortran routines with
3938 character(len=constant) arguments if the hidden string length arguments
3939 are passed on the stack; if the callers forget to pass those arguments,
3940 attempting to tail call in such routines leads to stack corruption.
3941 Avoid tail calls in functions where at least one such hidden string
3942 length argument is passed (partially or fully) on the stack in the
3943 caller and the callee needs to pass any arguments on the stack.
3945 if (try_tail_call
&& maybe_ne (args_size
.constant
, 0))
3946 for (tree arg
= DECL_ARGUMENTS (current_function_decl
);
3947 arg
; arg
= DECL_CHAIN (arg
))
3948 if (DECL_HIDDEN_STRING_LENGTH (arg
) && DECL_INCOMING_RTL (arg
))
3950 subrtx_iterator::array_type array
;
3951 FOR_EACH_SUBRTX (iter
, array
, DECL_INCOMING_RTL (arg
), NONCONST
)
3959 /* If the user has marked the function as requiring tail-call
3960 optimization, attempt it. */
3964 /* Rest of purposes for tail call optimizations to fail. */
3966 try_tail_call
= can_implement_as_sibling_call_p (exp
,
3967 structure_value_addr
,
3969 reg_parm_stack_space
,
3971 flags
, addr
, args_size
);
3973 /* Check if caller and callee disagree in promotion of function
3977 machine_mode caller_mode
, caller_promoted_mode
;
3978 machine_mode callee_mode
, callee_promoted_mode
;
3979 int caller_unsignedp
, callee_unsignedp
;
3980 tree caller_res
= DECL_RESULT (current_function_decl
);
3982 caller_unsignedp
= TYPE_UNSIGNED (TREE_TYPE (caller_res
));
3983 caller_mode
= DECL_MODE (caller_res
);
3984 callee_unsignedp
= TYPE_UNSIGNED (TREE_TYPE (funtype
));
3985 callee_mode
= TYPE_MODE (TREE_TYPE (funtype
));
3986 caller_promoted_mode
3987 = promote_function_mode (TREE_TYPE (caller_res
), caller_mode
,
3989 TREE_TYPE (current_function_decl
), 1);
3990 callee_promoted_mode
3991 = promote_function_mode (TREE_TYPE (funtype
), callee_mode
,
3994 if (caller_mode
!= VOIDmode
3995 && (caller_promoted_mode
!= callee_promoted_mode
3996 || ((caller_mode
!= caller_promoted_mode
3997 || callee_mode
!= callee_promoted_mode
)
3998 && (caller_unsignedp
!= callee_unsignedp
3999 || partial_subreg_p (caller_mode
, callee_mode
)))))
4002 maybe_complain_about_tail_call (exp
,
4003 "caller and callee disagree in"
4004 " promotion of function"
4009 /* Ensure current function's preferred stack boundary is at least
4010 what we need. Stack alignment may also increase preferred stack
4012 for (i
= 0; i
< num_actuals
; i
++)
4013 if (reg_parm_stack_space
> 0
4015 || args
[i
].partial
!= 0
4016 || args
[i
].pass_on_stack
)
4017 update_stack_alignment_for_call (&args
[i
].locate
);
4018 if (crtl
->preferred_stack_boundary
< preferred_stack_boundary
)
4019 crtl
->preferred_stack_boundary
= preferred_stack_boundary
;
4021 preferred_stack_boundary
= crtl
->preferred_stack_boundary
;
4023 preferred_unit_stack_boundary
= preferred_stack_boundary
/ BITS_PER_UNIT
;
4025 if (flag_callgraph_info
)
4026 record_final_call (fndecl
, EXPR_LOCATION (exp
));
4028 /* We want to make two insn chains; one for a sibling call, the other
4029 for a normal call. We will select one of the two chains after
4030 initial RTL generation is complete. */
4031 for (pass
= try_tail_call
? 0 : 1; pass
< 2; pass
++)
4033 int sibcall_failure
= 0;
4034 /* We want to emit any pending stack adjustments before the tail
4035 recursion "call". That way we know any adjustment after the tail
4036 recursion call can be ignored if we indeed use the tail
4038 saved_pending_stack_adjust save
;
4039 rtx_insn
*insns
, *before_call
, *after_args
;
4044 /* State variables we need to save and restore between
4046 save_pending_stack_adjust (&save
);
4049 flags
&= ~ECF_SIBCALL
;
4051 flags
|= ECF_SIBCALL
;
4053 /* Other state variables that we must reinitialize each time
4054 through the loop (that are not initialized by the loop itself). */
4058 /* Start a new sequence for the normal call case.
4060 From this point on, if the sibling call fails, we want to set
4061 sibcall_failure instead of continuing the loop. */
4064 /* Don't let pending stack adjusts add up to too much.
4065 Also, do all pending adjustments now if there is any chance
4066 this might be a call to alloca or if we are expanding a sibling
4068 Also do the adjustments before a throwing call, otherwise
4069 exception handling can fail; PR 19225. */
4070 if (maybe_ge (pending_stack_adjust
, 32)
4071 || (maybe_ne (pending_stack_adjust
, 0)
4072 && (flags
& ECF_MAY_BE_ALLOCA
))
4073 || (maybe_ne (pending_stack_adjust
, 0)
4074 && flag_exceptions
&& !(flags
& ECF_NOTHROW
))
4076 do_pending_stack_adjust ();
4078 /* Precompute any arguments as needed. */
4080 precompute_arguments (num_actuals
, args
);
4082 /* Now we are about to start emitting insns that can be deleted
4083 if a libcall is deleted. */
4084 if (pass
&& (flags
& ECF_MALLOC
))
4088 && crtl
->stack_protect_guard
4089 && targetm
.stack_protect_runtime_enabled_p ())
4090 stack_protect_epilogue ();
4092 adjusted_args_size
= args_size
;
4093 /* Compute the actual size of the argument block required. The variable
4094 and constant sizes must be combined, the size may have to be rounded,
4095 and there may be a minimum required size. When generating a sibcall
4096 pattern, do not round up, since we'll be re-using whatever space our
4098 unadjusted_args_size
4099 = compute_argument_block_size (reg_parm_stack_space
,
4100 &adjusted_args_size
,
4103 : preferred_stack_boundary
));
4105 old_stack_allocated
= stack_pointer_delta
- pending_stack_adjust
;
4107 /* The argument block when performing a sibling call is the
4108 incoming argument block. */
4111 argblock
= crtl
->args
.internal_arg_pointer
;
4112 if (STACK_GROWS_DOWNWARD
)
4114 = plus_constant (Pmode
, argblock
, crtl
->args
.pretend_args_size
);
4117 = plus_constant (Pmode
, argblock
, -crtl
->args
.pretend_args_size
);
4119 HOST_WIDE_INT map_size
= constant_lower_bound (args_size
.constant
);
4120 stored_args_map
= sbitmap_alloc (map_size
);
4121 bitmap_clear (stored_args_map
);
4122 stored_args_watermark
= HOST_WIDE_INT_M1U
;
4125 /* If we have no actual push instructions, or shouldn't use them,
4126 make space for all args right now. */
4127 else if (adjusted_args_size
.var
!= 0)
4129 if (old_stack_level
== 0)
4131 emit_stack_save (SAVE_BLOCK
, &old_stack_level
);
4132 old_stack_pointer_delta
= stack_pointer_delta
;
4133 old_pending_adj
= pending_stack_adjust
;
4134 pending_stack_adjust
= 0;
4135 /* stack_arg_under_construction says whether a stack arg is
4136 being constructed at the old stack level. Pushing the stack
4137 gets a clean outgoing argument block. */
4138 old_stack_arg_under_construction
= stack_arg_under_construction
;
4139 stack_arg_under_construction
= 0;
4141 argblock
= push_block (ARGS_SIZE_RTX (adjusted_args_size
), 0, 0);
4142 if (flag_stack_usage_info
)
4143 current_function_has_unbounded_dynamic_stack_size
= 1;
4147 /* Note that we must go through the motions of allocating an argument
4148 block even if the size is zero because we may be storing args
4149 in the area reserved for register arguments, which may be part of
4152 poly_int64 needed
= adjusted_args_size
.constant
;
4154 /* Store the maximum argument space used. It will be pushed by
4155 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
4158 crtl
->outgoing_args_size
= upper_bound (crtl
->outgoing_args_size
,
4161 if (must_preallocate
)
4163 if (ACCUMULATE_OUTGOING_ARGS
)
4165 /* Since the stack pointer will never be pushed, it is
4166 possible for the evaluation of a parm to clobber
4167 something we have already written to the stack.
4168 Since most function calls on RISC machines do not use
4169 the stack, this is uncommon, but must work correctly.
4171 Therefore, we save any area of the stack that was already
4172 written and that we are using. Here we set up to do this
4173 by making a new stack usage map from the old one. The
4174 actual save will be done by store_one_arg.
4176 Another approach might be to try to reorder the argument
4177 evaluations to avoid this conflicting stack usage. */
4179 /* Since we will be writing into the entire argument area,
4180 the map must be allocated for its entire size, not just
4181 the part that is the responsibility of the caller. */
4182 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl
? fntype
: TREE_TYPE (fndecl
))))
4183 needed
+= reg_parm_stack_space
;
4185 poly_int64 limit
= needed
;
4186 if (ARGS_GROW_DOWNWARD
)
4189 /* For polynomial sizes, this is the maximum possible
4190 size needed for arguments with a constant size
4192 HOST_WIDE_INT const_limit
= constant_lower_bound (limit
);
4193 highest_outgoing_arg_in_use
4194 = MAX (initial_highest_arg_in_use
, const_limit
);
4196 free (stack_usage_map_buf
);
4197 stack_usage_map_buf
= XNEWVEC (char, highest_outgoing_arg_in_use
);
4198 stack_usage_map
= stack_usage_map_buf
;
4200 if (initial_highest_arg_in_use
)
4201 memcpy (stack_usage_map
, initial_stack_usage_map
,
4202 initial_highest_arg_in_use
);
4204 if (initial_highest_arg_in_use
!= highest_outgoing_arg_in_use
)
4205 memset (&stack_usage_map
[initial_highest_arg_in_use
], 0,
4206 (highest_outgoing_arg_in_use
4207 - initial_highest_arg_in_use
));
4210 /* The address of the outgoing argument list must not be
4211 copied to a register here, because argblock would be left
4212 pointing to the wrong place after the call to
4213 allocate_dynamic_stack_space below. */
4215 argblock
= virtual_outgoing_args_rtx
;
4219 /* Try to reuse some or all of the pending_stack_adjust
4220 to get this space. */
4221 if (inhibit_defer_pop
== 0
4222 && (combine_pending_stack_adjustment_and_call
4224 unadjusted_args_size
,
4225 &adjusted_args_size
,
4226 preferred_unit_stack_boundary
)))
4228 /* combine_pending_stack_adjustment_and_call computes
4229 an adjustment before the arguments are allocated.
4230 Account for them and see whether or not the stack
4231 needs to go up or down. */
4232 needed
= unadjusted_args_size
- needed
;
4235 combine_pending_stack_adjustment_and_call. */
4236 gcc_checking_assert (ordered_p (needed
, 0));
4237 if (maybe_lt (needed
, 0))
4239 /* We're releasing stack space. */
4240 /* ??? We can avoid any adjustment at all if we're
4241 already aligned. FIXME. */
4242 pending_stack_adjust
= -needed
;
4243 do_pending_stack_adjust ();
4247 /* We need to allocate space. We'll do that in
4248 push_block below. */
4249 pending_stack_adjust
= 0;
4252 /* Special case this because overhead of `push_block' in
4253 this case is non-trivial. */
4254 if (known_eq (needed
, 0))
4255 argblock
= virtual_outgoing_args_rtx
;
4258 rtx needed_rtx
= gen_int_mode (needed
, Pmode
);
4259 argblock
= push_block (needed_rtx
, 0, 0);
4260 if (ARGS_GROW_DOWNWARD
)
4261 argblock
= plus_constant (Pmode
, argblock
, needed
);
4264 /* We only really need to call `copy_to_reg' in the case
4265 where push insns are going to be used to pass ARGBLOCK
4266 to a function call in ARGS. In that case, the stack
4267 pointer changes value from the allocation point to the
4268 call point, and hence the value of
4269 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
4270 as well always do it. */
4271 argblock
= copy_to_reg (argblock
);
4276 if (ACCUMULATE_OUTGOING_ARGS
)
4278 /* The save/restore code in store_one_arg handles all
4279 cases except one: a constructor call (including a C
4280 function returning a BLKmode struct) to initialize
4282 if (stack_arg_under_construction
)
4286 (adjusted_args_size
.constant
4287 + (OUTGOING_REG_PARM_STACK_SPACE (!fndecl
? fntype
4288 : TREE_TYPE (fndecl
))
4289 ? 0 : reg_parm_stack_space
), Pmode
));
4290 if (old_stack_level
== 0)
4292 emit_stack_save (SAVE_BLOCK
, &old_stack_level
);
4293 old_stack_pointer_delta
= stack_pointer_delta
;
4294 old_pending_adj
= pending_stack_adjust
;
4295 pending_stack_adjust
= 0;
4296 /* stack_arg_under_construction says whether a stack
4297 arg is being constructed at the old stack level.
4298 Pushing the stack gets a clean outgoing argument
4300 old_stack_arg_under_construction
4301 = stack_arg_under_construction
;
4302 stack_arg_under_construction
= 0;
4303 /* Make a new map for the new argument list. */
4304 free (stack_usage_map_buf
);
4305 stack_usage_map_buf
= XCNEWVEC (char, highest_outgoing_arg_in_use
);
4306 stack_usage_map
= stack_usage_map_buf
;
4307 highest_outgoing_arg_in_use
= 0;
4308 stack_usage_watermark
= HOST_WIDE_INT_M1U
;
4310 /* We can pass TRUE as the 4th argument because we just
4311 saved the stack pointer and will restore it right after
4313 allocate_dynamic_stack_space (push_size
, 0, BIGGEST_ALIGNMENT
,
4317 /* If argument evaluation might modify the stack pointer,
4318 copy the address of the argument list to a register. */
4319 for (i
= 0; i
< num_actuals
; i
++)
4320 if (args
[i
].pass_on_stack
)
4322 argblock
= copy_addr_to_reg (argblock
);
4327 compute_argument_addresses (args
, argblock
, num_actuals
);
4329 /* Stack is properly aligned, pops can't safely be deferred during
4330 the evaluation of the arguments. */
4333 /* Precompute all register parameters. It isn't safe to compute
4334 anything once we have started filling any specific hard regs.
4335 TLS symbols sometimes need a call to resolve. Precompute
4336 register parameters before any stack pointer manipulation
4337 to avoid unaligned stack in the called function. */
4338 precompute_register_parameters (num_actuals
, args
, ®_parm_seen
);
4342 /* Perform stack alignment before the first push (the last arg). */
4344 && maybe_gt (adjusted_args_size
.constant
, reg_parm_stack_space
)
4345 && maybe_ne (adjusted_args_size
.constant
, unadjusted_args_size
))
4347 /* When the stack adjustment is pending, we get better code
4348 by combining the adjustments. */
4349 if (maybe_ne (pending_stack_adjust
, 0)
4350 && ! inhibit_defer_pop
4351 && (combine_pending_stack_adjustment_and_call
4352 (&pending_stack_adjust
,
4353 unadjusted_args_size
,
4354 &adjusted_args_size
,
4355 preferred_unit_stack_boundary
)))
4356 do_pending_stack_adjust ();
4357 else if (argblock
== 0)
4358 anti_adjust_stack (gen_int_mode (adjusted_args_size
.constant
4359 - unadjusted_args_size
,
4362 /* Now that the stack is properly aligned, pops can't safely
4363 be deferred during the evaluation of the arguments. */
4366 /* Record the maximum pushed stack space size. We need to delay
4367 doing it this far to take into account the optimization done
4368 by combine_pending_stack_adjustment_and_call. */
4369 if (flag_stack_usage_info
4370 && !ACCUMULATE_OUTGOING_ARGS
4372 && adjusted_args_size
.var
== 0)
4374 poly_int64 pushed
= (adjusted_args_size
.constant
4375 + pending_stack_adjust
);
4376 current_function_pushed_stack_size
4377 = upper_bound (current_function_pushed_stack_size
, pushed
);
4380 funexp
= rtx_for_function_call (fndecl
, addr
);
4382 if (CALL_EXPR_STATIC_CHAIN (exp
))
4383 static_chain_value
= expand_normal (CALL_EXPR_STATIC_CHAIN (exp
));
4385 static_chain_value
= 0;
4387 #ifdef REG_PARM_STACK_SPACE
4388 /* Save the fixed argument area if it's part of the caller's frame and
4389 is clobbered by argument setup for this call. */
4390 if (ACCUMULATE_OUTGOING_ARGS
&& pass
)
4391 save_area
= save_fixed_argument_area (reg_parm_stack_space
, argblock
,
4392 &low_to_save
, &high_to_save
);
4395 /* Now store (and compute if necessary) all non-register parms.
4396 These come before register parms, since they can require block-moves,
4397 which could clobber the registers used for register parms.
4398 Parms which have partial registers are not stored here,
4399 but we do preallocate space here if they want that. */
4401 for (i
= 0; i
< num_actuals
; i
++)
4403 if (args
[i
].reg
== 0 || args
[i
].pass_on_stack
)
4405 rtx_insn
*before_arg
= get_last_insn ();
4407 /* We don't allow passing huge (> 2^30 B) arguments
4408 by value. It would cause an overflow later on. */
4409 if (constant_lower_bound (adjusted_args_size
.constant
)
4410 >= (1 << (HOST_BITS_PER_INT
- 2)))
4412 sorry ("passing too large argument on stack");
4416 if (store_one_arg (&args
[i
], argblock
, flags
,
4417 adjusted_args_size
.var
!= 0,
4418 reg_parm_stack_space
)
4420 && check_sibcall_argument_overlap (before_arg
,
4422 sibcall_failure
= 1;
4427 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)),
4428 gen_rtx_USE (VOIDmode
, args
[i
].stack
),
4432 /* If we have a parm that is passed in registers but not in memory
4433 and whose alignment does not permit a direct copy into registers,
4434 make a group of pseudos that correspond to each register that we
4436 if (STRICT_ALIGNMENT
)
4437 store_unaligned_arguments_into_pseudos (args
, num_actuals
);
4439 /* Now store any partially-in-registers parm.
4440 This is the last place a block-move can happen. */
4442 for (i
= 0; i
< num_actuals
; i
++)
4443 if (args
[i
].partial
!= 0 && ! args
[i
].pass_on_stack
)
4445 rtx_insn
*before_arg
= get_last_insn ();
4447 /* On targets with weird calling conventions (e.g. PA) it's
4448 hard to ensure that all cases of argument overlap between
4449 stack and registers work. Play it safe and bail out. */
4450 if (ARGS_GROW_DOWNWARD
&& !STACK_GROWS_DOWNWARD
)
4452 sibcall_failure
= 1;
4456 if (store_one_arg (&args
[i
], argblock
, flags
,
4457 adjusted_args_size
.var
!= 0,
4458 reg_parm_stack_space
)
4460 && check_sibcall_argument_overlap (before_arg
,
4462 sibcall_failure
= 1;
4465 bool any_regs
= false;
4466 for (i
= 0; i
< num_actuals
; i
++)
4467 if (args
[i
].reg
!= NULL_RTX
)
4470 targetm
.calls
.call_args (args
[i
].reg
, funtype
);
4473 targetm
.calls
.call_args (pc_rtx
, funtype
);
4475 /* Figure out the register where the value, if any, will come back. */
4477 if (TYPE_MODE (rettype
) != VOIDmode
4478 && ! structure_value_addr
)
4480 if (pcc_struct_value
)
4481 valreg
= hard_function_value (build_pointer_type (rettype
),
4482 fndecl
, NULL
, (pass
== 0));
4484 valreg
= hard_function_value (rettype
, fndecl
, fntype
,
4487 /* If VALREG is a PARALLEL whose first member has a zero
4488 offset, use that. This is for targets such as m68k that
4489 return the same value in multiple places. */
4490 if (GET_CODE (valreg
) == PARALLEL
)
4492 rtx elem
= XVECEXP (valreg
, 0, 0);
4493 rtx where
= XEXP (elem
, 0);
4494 rtx offset
= XEXP (elem
, 1);
4495 if (offset
== const0_rtx
4496 && GET_MODE (where
) == GET_MODE (valreg
))
4501 /* If register arguments require space on the stack and stack space
4502 was not preallocated, allocate stack space here for arguments
4503 passed in registers. */
4504 if (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl
? fntype
: TREE_TYPE (fndecl
)))
4505 && !ACCUMULATE_OUTGOING_ARGS
4506 && must_preallocate
== 0 && reg_parm_stack_space
> 0)
4507 anti_adjust_stack (GEN_INT (reg_parm_stack_space
));
4509 /* Pass the function the address in which to return a
4511 if (pass
!= 0 && structure_value_addr
&& ! structure_value_addr_parm
)
4513 structure_value_addr
4514 = convert_memory_address (Pmode
, structure_value_addr
);
4515 emit_move_insn (struct_value
,
4517 force_operand (structure_value_addr
,
4520 if (REG_P (struct_value
))
4521 use_reg (&call_fusage
, struct_value
);
4524 after_args
= get_last_insn ();
4525 funexp
= prepare_call_address (fndecl
? fndecl
: fntype
, funexp
,
4526 static_chain_value
, &call_fusage
,
4527 reg_parm_seen
, flags
);
4529 load_register_parameters (args
, num_actuals
, &call_fusage
, flags
,
4530 pass
== 0, &sibcall_failure
);
4532 /* Save a pointer to the last insn before the call, so that we can
4533 later safely search backwards to find the CALL_INSN. */
4534 before_call
= get_last_insn ();
4536 /* Set up next argument register. For sibling calls on machines
4537 with register windows this should be the incoming register. */
4539 next_arg_reg
= targetm
.calls
.function_incoming_arg
4540 (args_so_far
, function_arg_info::end_marker ());
4542 next_arg_reg
= targetm
.calls
.function_arg
4543 (args_so_far
, function_arg_info::end_marker ());
4545 if (pass
== 1 && (return_flags
& ERF_RETURNS_ARG
))
4547 int arg_nr
= return_flags
& ERF_RETURN_ARG_MASK
;
4548 arg_nr
= num_actuals
- arg_nr
- 1;
4550 && arg_nr
< num_actuals
4554 && GET_MODE (args
[arg_nr
].reg
) == GET_MODE (valreg
))
4556 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args
[arg_nr
].tree_value
)),
4557 gen_rtx_SET (valreg
, args
[arg_nr
].reg
),
4560 /* All arguments and registers used for the call must be set up by
4563 /* Stack must be properly aligned now. */
4565 || multiple_p (stack_pointer_delta
,
4566 preferred_unit_stack_boundary
));
4568 /* Generate the actual call instruction. */
4569 emit_call_1 (funexp
, exp
, fndecl
, funtype
, unadjusted_args_size
,
4570 adjusted_args_size
.constant
, struct_value_size
,
4571 next_arg_reg
, valreg
, old_inhibit_defer_pop
, call_fusage
,
4572 flags
, args_so_far
);
4576 rtx_call_insn
*last
;
4577 rtx datum
= NULL_RTX
;
4578 if (fndecl
!= NULL_TREE
)
4580 datum
= XEXP (DECL_RTL (fndecl
), 0);
4581 gcc_assert (datum
!= NULL_RTX
4582 && GET_CODE (datum
) == SYMBOL_REF
);
4584 last
= last_call_insn ();
4585 add_reg_note (last
, REG_CALL_DECL
, datum
);
4588 /* If the call setup or the call itself overlaps with anything
4589 of the argument setup we probably clobbered our call address.
4590 In that case we can't do sibcalls. */
4592 && check_sibcall_argument_overlap (after_args
, 0, 0))
4593 sibcall_failure
= 1;
4595 /* If a non-BLKmode value is returned at the most significant end
4596 of a register, shift the register right by the appropriate amount
4597 and update VALREG accordingly. BLKmode values are handled by the
4598 group load/store machinery below. */
4599 if (!structure_value_addr
4600 && !pcc_struct_value
4601 && TYPE_MODE (rettype
) != VOIDmode
4602 && TYPE_MODE (rettype
) != BLKmode
4604 && targetm
.calls
.return_in_msb (rettype
))
4606 if (shift_return_value (TYPE_MODE (rettype
), false, valreg
))
4607 sibcall_failure
= 1;
4608 valreg
= gen_rtx_REG (TYPE_MODE (rettype
), REGNO (valreg
));
4611 if (pass
&& (flags
& ECF_MALLOC
))
4613 rtx temp
= gen_reg_rtx (GET_MODE (valreg
));
4614 rtx_insn
*last
, *insns
;
4616 /* The return value from a malloc-like function is a pointer. */
4617 if (TREE_CODE (rettype
) == POINTER_TYPE
)
4618 mark_reg_pointer (temp
, MALLOC_ABI_ALIGNMENT
);
4620 emit_move_insn (temp
, valreg
);
4622 /* The return value from a malloc-like function cannot alias
4624 last
= get_last_insn ();
4625 add_reg_note (last
, REG_NOALIAS
, temp
);
4627 /* Write out the sequence. */
4628 insns
= get_insns ();
4634 /* For calls to `setjmp', etc., inform
4635 function.c:setjmp_warnings that it should complain if
4636 nonvolatile values are live. For functions that cannot
4637 return, inform flow that control does not fall through. */
4639 if ((flags
& ECF_NORETURN
) || pass
== 0)
4641 /* The barrier must be emitted
4642 immediately after the CALL_INSN. Some ports emit more
4643 than just a CALL_INSN above, so we must search for it here. */
4645 rtx_insn
*last
= get_last_insn ();
4646 while (!CALL_P (last
))
4648 last
= PREV_INSN (last
);
4649 /* There was no CALL_INSN? */
4650 gcc_assert (last
!= before_call
);
4653 emit_barrier_after (last
);
4655 /* Stack adjustments after a noreturn call are dead code.
4656 However when NO_DEFER_POP is in effect, we must preserve
4657 stack_pointer_delta. */
4658 if (inhibit_defer_pop
== 0)
4660 stack_pointer_delta
= old_stack_allocated
;
4661 pending_stack_adjust
= 0;
4665 /* If value type not void, return an rtx for the value. */
4667 if (TYPE_MODE (rettype
) == VOIDmode
4669 target
= const0_rtx
;
4670 else if (structure_value_addr
)
4672 if (target
== 0 || !MEM_P (target
))
4675 = gen_rtx_MEM (TYPE_MODE (rettype
),
4676 memory_address (TYPE_MODE (rettype
),
4677 structure_value_addr
));
4678 set_mem_attributes (target
, rettype
, 1);
4681 else if (pcc_struct_value
)
4683 /* This is the special C++ case where we need to
4684 know what the true target was. We take care to
4685 never use this value more than once in one expression. */
4686 target
= gen_rtx_MEM (TYPE_MODE (rettype
),
4687 copy_to_reg (valreg
));
4688 set_mem_attributes (target
, rettype
, 1);
4690 /* Handle calls that return values in multiple non-contiguous locations.
4691 The Irix 6 ABI has examples of this. */
4692 else if (GET_CODE (valreg
) == PARALLEL
)
4695 target
= emit_group_move_into_temps (valreg
);
4696 else if (rtx_equal_p (target
, valreg
))
4698 else if (GET_CODE (target
) == PARALLEL
)
4699 /* Handle the result of a emit_group_move_into_temps
4700 call in the previous pass. */
4701 emit_group_move (target
, valreg
);
4703 emit_group_store (target
, valreg
, rettype
,
4704 int_size_in_bytes (rettype
));
4707 && GET_MODE (target
) == TYPE_MODE (rettype
)
4708 && GET_MODE (target
) == GET_MODE (valreg
))
4710 bool may_overlap
= false;
4712 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
4713 reg to a plain register. */
4714 if (!REG_P (target
) || HARD_REGISTER_P (target
))
4715 valreg
= avoid_likely_spilled_reg (valreg
);
4717 /* If TARGET is a MEM in the argument area, and we have
4718 saved part of the argument area, then we can't store
4719 directly into TARGET as it may get overwritten when we
4720 restore the argument save area below. Don't work too
4721 hard though and simply force TARGET to a register if it
4722 is a MEM; the optimizer is quite likely to sort it out. */
4723 if (ACCUMULATE_OUTGOING_ARGS
&& pass
&& MEM_P (target
))
4724 for (i
= 0; i
< num_actuals
; i
++)
4725 if (args
[i
].save_area
)
4732 target
= copy_to_reg (valreg
);
4735 /* TARGET and VALREG cannot be equal at this point
4736 because the latter would not have
4737 REG_FUNCTION_VALUE_P true, while the former would if
4738 it were referring to the same register.
4740 If they refer to the same register, this move will be
4741 a no-op, except when function inlining is being
4743 emit_move_insn (target
, valreg
);
4745 /* If we are setting a MEM, this code must be executed.
4746 Since it is emitted after the call insn, sibcall
4747 optimization cannot be performed in that case. */
4749 sibcall_failure
= 1;
4753 target
= copy_to_reg (avoid_likely_spilled_reg (valreg
));
4755 /* If we promoted this return value, make the proper SUBREG.
4756 TARGET might be const0_rtx here, so be careful. */
4758 && TYPE_MODE (rettype
) != BLKmode
4759 && GET_MODE (target
) != TYPE_MODE (rettype
))
4761 tree type
= rettype
;
4762 int unsignedp
= TYPE_UNSIGNED (type
);
4765 /* Ensure we promote as expected, and get the new unsignedness. */
4766 pmode
= promote_function_mode (type
, TYPE_MODE (type
), &unsignedp
,
4768 gcc_assert (GET_MODE (target
) == pmode
);
4770 poly_uint64 offset
= subreg_lowpart_offset (TYPE_MODE (type
),
4772 target
= gen_rtx_SUBREG (TYPE_MODE (type
), target
, offset
);
4773 SUBREG_PROMOTED_VAR_P (target
) = 1;
4774 SUBREG_PROMOTED_SET (target
, unsignedp
);
4777 /* If size of args is variable or this was a constructor call for a stack
4778 argument, restore saved stack-pointer value. */
4780 if (old_stack_level
)
4782 rtx_insn
*prev
= get_last_insn ();
4784 emit_stack_restore (SAVE_BLOCK
, old_stack_level
);
4785 stack_pointer_delta
= old_stack_pointer_delta
;
4787 fixup_args_size_notes (prev
, get_last_insn (), stack_pointer_delta
);
4789 pending_stack_adjust
= old_pending_adj
;
4790 old_stack_allocated
= stack_pointer_delta
- pending_stack_adjust
;
4791 stack_arg_under_construction
= old_stack_arg_under_construction
;
4792 highest_outgoing_arg_in_use
= initial_highest_arg_in_use
;
4793 stack_usage_map
= initial_stack_usage_map
;
4794 stack_usage_watermark
= initial_stack_usage_watermark
;
4795 sibcall_failure
= 1;
4797 else if (ACCUMULATE_OUTGOING_ARGS
&& pass
)
4799 #ifdef REG_PARM_STACK_SPACE
4801 restore_fixed_argument_area (save_area
, argblock
,
4802 high_to_save
, low_to_save
);
4805 /* If we saved any argument areas, restore them. */
4806 for (i
= 0; i
< num_actuals
; i
++)
4807 if (args
[i
].save_area
)
4809 machine_mode save_mode
= GET_MODE (args
[i
].save_area
);
4811 = gen_rtx_MEM (save_mode
,
4812 memory_address (save_mode
,
4813 XEXP (args
[i
].stack_slot
, 0)));
4815 if (save_mode
!= BLKmode
)
4816 emit_move_insn (stack_area
, args
[i
].save_area
);
4818 emit_block_move (stack_area
, args
[i
].save_area
,
4820 (args
[i
].locate
.size
.constant
, Pmode
)),
4821 BLOCK_OP_CALL_PARM
);
4824 highest_outgoing_arg_in_use
= initial_highest_arg_in_use
;
4825 stack_usage_map
= initial_stack_usage_map
;
4826 stack_usage_watermark
= initial_stack_usage_watermark
;
4829 /* If this was alloca, record the new stack level. */
4830 if (flags
& ECF_MAY_BE_ALLOCA
)
4831 record_new_stack_level ();
4833 /* Free up storage we no longer need. */
4834 for (i
= 0; i
< num_actuals
; ++i
)
4835 free (args
[i
].aligned_regs
);
4837 targetm
.calls
.end_call_args ();
4839 insns
= get_insns ();
4844 tail_call_insns
= insns
;
4846 /* Restore the pending stack adjustment now that we have
4847 finished generating the sibling call sequence. */
4849 restore_pending_stack_adjust (&save
);
4851 /* Prepare arg structure for next iteration. */
4852 for (i
= 0; i
< num_actuals
; i
++)
4855 args
[i
].aligned_regs
= 0;
4859 sbitmap_free (stored_args_map
);
4860 internal_arg_pointer_exp_state
.scan_start
= NULL
;
4861 internal_arg_pointer_exp_state
.cache
.release ();
4865 normal_call_insns
= insns
;
4867 /* Verify that we've deallocated all the stack we used. */
4868 gcc_assert ((flags
& ECF_NORETURN
)
4869 || known_eq (old_stack_allocated
,
4871 - pending_stack_adjust
));
4874 /* If something prevents making this a sibling call,
4875 zero out the sequence. */
4876 if (sibcall_failure
)
4877 tail_call_insns
= NULL
;
4882 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
4883 arguments too, as argument area is now clobbered by the call. */
4884 if (tail_call_insns
)
4886 emit_insn (tail_call_insns
);
4887 crtl
->tail_call_emit
= true;
4891 emit_insn (normal_call_insns
);
4893 /* Ideally we'd emit a message for all of the ways that it could
4895 maybe_complain_about_tail_call (exp
, "tail call production failed");
4898 currently_expanding_call
--;
4900 free (stack_usage_map_buf
);
4905 /* A sibling call sequence invalidates any REG_EQUIV notes made for
4906 this function's incoming arguments.
4908 At the start of RTL generation we know the only REG_EQUIV notes
4909 in the rtl chain are those for incoming arguments, so we can look
4910 for REG_EQUIV notes between the start of the function and the
4911 NOTE_INSN_FUNCTION_BEG.
4913 This is (slight) overkill. We could keep track of the highest
4914 argument we clobber and be more selective in removing notes, but it
4915 does not seem to be worth the effort. */
4918 fixup_tail_calls (void)
4922 for (insn
= get_insns (); insn
; insn
= NEXT_INSN (insn
))
4926 /* There are never REG_EQUIV notes for the incoming arguments
4927 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
4929 && NOTE_KIND (insn
) == NOTE_INSN_FUNCTION_BEG
)
4932 note
= find_reg_note (insn
, REG_EQUIV
, 0);
4934 remove_note (insn
, note
);
4935 note
= find_reg_note (insn
, REG_EQUIV
, 0);
4940 /* Traverse a list of TYPES and expand all complex types into their
4943 split_complex_types (tree types
)
4947 /* Before allocating memory, check for the common case of no complex. */
4948 for (p
= types
; p
; p
= TREE_CHAIN (p
))
4950 tree type
= TREE_VALUE (p
);
4951 if (TREE_CODE (type
) == COMPLEX_TYPE
4952 && targetm
.calls
.split_complex_arg (type
))
4958 types
= copy_list (types
);
4960 for (p
= types
; p
; p
= TREE_CHAIN (p
))
4962 tree complex_type
= TREE_VALUE (p
);
4964 if (TREE_CODE (complex_type
) == COMPLEX_TYPE
4965 && targetm
.calls
.split_complex_arg (complex_type
))
4969 /* Rewrite complex type with component type. */
4970 TREE_VALUE (p
) = TREE_TYPE (complex_type
);
4971 next
= TREE_CHAIN (p
);
4973 /* Add another component type for the imaginary part. */
4974 imag
= build_tree_list (NULL_TREE
, TREE_VALUE (p
));
4975 TREE_CHAIN (p
) = imag
;
4976 TREE_CHAIN (imag
) = next
;
4978 /* Skip the newly created node. */
4986 /* Output a library call to function ORGFUN (a SYMBOL_REF rtx)
4987 for a value of mode OUTMODE,
4988 with NARGS different arguments, passed as ARGS.
4989 Store the return value if RETVAL is nonzero: store it in VALUE if
4990 VALUE is nonnull, otherwise pick a convenient location. In either
4991 case return the location of the stored value.
4993 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
4994 `const' calls, LCT_PURE for `pure' calls, or another LCT_ value for
4995 other types of library calls. */
4998 emit_library_call_value_1 (int retval
, rtx orgfun
, rtx value
,
4999 enum libcall_type fn_type
,
5000 machine_mode outmode
, int nargs
, rtx_mode_t
*args
)
5002 /* Total size in bytes of all the stack-parms scanned so far. */
5003 struct args_size args_size
;
5004 /* Size of arguments before any adjustments (such as rounding). */
5005 struct args_size original_args_size
;
5008 /* Todo, choose the correct decl type of orgfun. Sadly this information
5009 isn't present here, so we default to native calling abi here. */
5010 tree fndecl ATTRIBUTE_UNUSED
= NULL_TREE
; /* library calls default to host calling abi ? */
5011 tree fntype ATTRIBUTE_UNUSED
= NULL_TREE
; /* library calls default to host calling abi ? */
5014 CUMULATIVE_ARGS args_so_far_v
;
5015 cumulative_args_t args_so_far
;
5022 struct locate_and_pad_arg_data locate
;
5026 int old_inhibit_defer_pop
= inhibit_defer_pop
;
5027 rtx call_fusage
= 0;
5030 int pcc_struct_value
= 0;
5031 poly_int64 struct_value_size
= 0;
5033 int reg_parm_stack_space
= 0;
5035 rtx_insn
*before_call
;
5036 bool have_push_fusage
;
5037 tree tfom
; /* type_for_mode (outmode, 0) */
5039 #ifdef REG_PARM_STACK_SPACE
5040 /* Define the boundary of the register parm stack space that needs to be
5042 int low_to_save
= 0, high_to_save
= 0;
5043 rtx save_area
= 0; /* Place that it is saved. */
5046 /* Size of the stack reserved for parameter registers. */
5047 unsigned int initial_highest_arg_in_use
= highest_outgoing_arg_in_use
;
5048 char *initial_stack_usage_map
= stack_usage_map
;
5049 unsigned HOST_WIDE_INT initial_stack_usage_watermark
= stack_usage_watermark
;
5050 char *stack_usage_map_buf
= NULL
;
5052 rtx struct_value
= targetm
.calls
.struct_value_rtx (0, 0);
5054 #ifdef REG_PARM_STACK_SPACE
5055 reg_parm_stack_space
= REG_PARM_STACK_SPACE ((tree
) 0);
5058 /* By default, library functions cannot throw. */
5059 flags
= ECF_NOTHROW
;
5072 flags
|= ECF_NORETURN
;
5075 flags
&= ~ECF_NOTHROW
;
5077 case LCT_RETURNS_TWICE
:
5078 flags
= ECF_RETURNS_TWICE
;
5083 /* Ensure current function's preferred stack boundary is at least
5085 if (crtl
->preferred_stack_boundary
< PREFERRED_STACK_BOUNDARY
)
5086 crtl
->preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
5088 /* If this kind of value comes back in memory,
5089 decide where in memory it should come back. */
5090 if (outmode
!= VOIDmode
)
5092 tfom
= lang_hooks
.types
.type_for_mode (outmode
, 0);
5093 if (aggregate_value_p (tfom
, 0))
5095 #ifdef PCC_STATIC_STRUCT_RETURN
5097 = hard_function_value (build_pointer_type (tfom
), 0, 0, 0);
5098 mem_value
= gen_rtx_MEM (outmode
, pointer_reg
);
5099 pcc_struct_value
= 1;
5101 value
= gen_reg_rtx (outmode
);
5102 #else /* not PCC_STATIC_STRUCT_RETURN */
5103 struct_value_size
= GET_MODE_SIZE (outmode
);
5104 if (value
!= 0 && MEM_P (value
))
5107 mem_value
= assign_temp (tfom
, 1, 1);
5109 /* This call returns a big structure. */
5110 flags
&= ~(ECF_CONST
| ECF_PURE
| ECF_LOOPING_CONST_OR_PURE
);
5114 tfom
= void_type_node
;
5116 /* ??? Unfinished: must pass the memory address as an argument. */
5118 /* Copy all the libcall-arguments out of the varargs data
5119 and into a vector ARGVEC.
5121 Compute how to pass each argument. We only support a very small subset
5122 of the full argument passing conventions to limit complexity here since
5123 library functions shouldn't have many args. */
5125 argvec
= XALLOCAVEC (struct arg
, nargs
+ 1);
5126 memset (argvec
, 0, (nargs
+ 1) * sizeof (struct arg
));
5128 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
5129 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far_v
, outmode
, fun
);
5131 INIT_CUMULATIVE_ARGS (args_so_far_v
, NULL_TREE
, fun
, 0, nargs
);
5133 args_so_far
= pack_cumulative_args (&args_so_far_v
);
5135 args_size
.constant
= 0;
5142 /* If there's a structure value address to be passed,
5143 either pass it in the special place, or pass it as an extra argument. */
5144 if (mem_value
&& struct_value
== 0 && ! pcc_struct_value
)
5146 rtx addr
= XEXP (mem_value
, 0);
5150 /* Make sure it is a reasonable operand for a move or push insn. */
5151 if (!REG_P (addr
) && !MEM_P (addr
)
5152 && !(CONSTANT_P (addr
)
5153 && targetm
.legitimate_constant_p (Pmode
, addr
)))
5154 addr
= force_operand (addr
, NULL_RTX
);
5156 argvec
[count
].value
= addr
;
5157 argvec
[count
].mode
= Pmode
;
5158 argvec
[count
].partial
= 0;
5160 function_arg_info
ptr_arg (Pmode
, /*named=*/true);
5161 argvec
[count
].reg
= targetm
.calls
.function_arg (args_so_far
, ptr_arg
);
5162 gcc_assert (targetm
.calls
.arg_partial_bytes (args_so_far
, ptr_arg
) == 0);
5164 locate_and_pad_parm (Pmode
, NULL_TREE
,
5165 #ifdef STACK_PARMS_IN_REG_PARM_AREA
5168 argvec
[count
].reg
!= 0,
5170 reg_parm_stack_space
, 0,
5171 NULL_TREE
, &args_size
, &argvec
[count
].locate
);
5173 if (argvec
[count
].reg
== 0 || argvec
[count
].partial
!= 0
5174 || reg_parm_stack_space
> 0)
5175 args_size
.constant
+= argvec
[count
].locate
.size
.constant
;
5177 targetm
.calls
.function_arg_advance (args_so_far
, ptr_arg
);
5182 for (unsigned int i
= 0; count
< nargs
; i
++, count
++)
5184 rtx val
= args
[i
].first
;
5185 function_arg_info
arg (args
[i
].second
, /*named=*/true);
5188 /* We cannot convert the arg value to the mode the library wants here;
5189 must do it earlier where we know the signedness of the arg. */
5190 gcc_assert (arg
.mode
!= BLKmode
5191 && (GET_MODE (val
) == arg
.mode
5192 || GET_MODE (val
) == VOIDmode
));
5194 /* Make sure it is a reasonable operand for a move or push insn. */
5195 if (!REG_P (val
) && !MEM_P (val
)
5196 && !(CONSTANT_P (val
)
5197 && targetm
.legitimate_constant_p (arg
.mode
, val
)))
5198 val
= force_operand (val
, NULL_RTX
);
5200 if (pass_by_reference (&args_so_far_v
, arg
))
5203 int must_copy
= !reference_callee_copied (&args_so_far_v
, arg
);
5205 /* If this was a CONST function, it is now PURE since it now
5207 if (flags
& ECF_CONST
)
5209 flags
&= ~ECF_CONST
;
5213 if (MEM_P (val
) && !must_copy
)
5215 tree val_expr
= MEM_EXPR (val
);
5217 mark_addressable (val_expr
);
5222 slot
= assign_temp (lang_hooks
.types
.type_for_mode (arg
.mode
, 0),
5224 emit_move_insn (slot
, val
);
5227 call_fusage
= gen_rtx_EXPR_LIST (VOIDmode
,
5228 gen_rtx_USE (VOIDmode
, slot
),
5231 call_fusage
= gen_rtx_EXPR_LIST (VOIDmode
,
5232 gen_rtx_CLOBBER (VOIDmode
,
5237 arg
.pass_by_reference
= true;
5238 val
= force_operand (XEXP (slot
, 0), NULL_RTX
);
5241 arg
.mode
= promote_function_mode (NULL_TREE
, arg
.mode
, &unsigned_p
,
5243 argvec
[count
].mode
= arg
.mode
;
5244 argvec
[count
].value
= convert_modes (arg
.mode
, GET_MODE (val
), val
,
5246 argvec
[count
].reg
= targetm
.calls
.function_arg (args_so_far
, arg
);
5248 argvec
[count
].partial
5249 = targetm
.calls
.arg_partial_bytes (args_so_far
, arg
);
5251 if (argvec
[count
].reg
== 0
5252 || argvec
[count
].partial
!= 0
5253 || reg_parm_stack_space
> 0)
5255 locate_and_pad_parm (arg
.mode
, NULL_TREE
,
5256 #ifdef STACK_PARMS_IN_REG_PARM_AREA
5259 argvec
[count
].reg
!= 0,
5261 reg_parm_stack_space
, argvec
[count
].partial
,
5262 NULL_TREE
, &args_size
, &argvec
[count
].locate
);
5263 args_size
.constant
+= argvec
[count
].locate
.size
.constant
;
5264 gcc_assert (!argvec
[count
].locate
.size
.var
);
5266 #ifdef BLOCK_REG_PADDING
5268 /* The argument is passed entirely in registers. See at which
5269 end it should be padded. */
5270 argvec
[count
].locate
.where_pad
=
5271 BLOCK_REG_PADDING (arg
.mode
, NULL_TREE
,
5272 known_le (GET_MODE_SIZE (arg
.mode
),
5276 targetm
.calls
.function_arg_advance (args_so_far
, arg
);
5279 for (int i
= 0; i
< nargs
; i
++)
5280 if (reg_parm_stack_space
> 0
5281 || argvec
[i
].reg
== 0
5282 || argvec
[i
].partial
!= 0)
5283 update_stack_alignment_for_call (&argvec
[i
].locate
);
5285 /* If this machine requires an external definition for library
5286 functions, write one out. */
5287 assemble_external_libcall (fun
);
5289 original_args_size
= args_size
;
5290 args_size
.constant
= (aligned_upper_bound (args_size
.constant
5291 + stack_pointer_delta
,
5293 - stack_pointer_delta
);
5295 args_size
.constant
= upper_bound (args_size
.constant
,
5296 reg_parm_stack_space
);
5298 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl
? fntype
: TREE_TYPE (fndecl
))))
5299 args_size
.constant
-= reg_parm_stack_space
;
5301 crtl
->outgoing_args_size
= upper_bound (crtl
->outgoing_args_size
,
5302 args_size
.constant
);
5304 if (flag_stack_usage_info
&& !ACCUMULATE_OUTGOING_ARGS
)
5306 poly_int64 pushed
= args_size
.constant
+ pending_stack_adjust
;
5307 current_function_pushed_stack_size
5308 = upper_bound (current_function_pushed_stack_size
, pushed
);
5311 if (ACCUMULATE_OUTGOING_ARGS
)
5313 /* Since the stack pointer will never be pushed, it is possible for
5314 the evaluation of a parm to clobber something we have already
5315 written to the stack. Since most function calls on RISC machines
5316 do not use the stack, this is uncommon, but must work correctly.
5318 Therefore, we save any area of the stack that was already written
5319 and that we are using. Here we set up to do this by making a new
5320 stack usage map from the old one.
5322 Another approach might be to try to reorder the argument
5323 evaluations to avoid this conflicting stack usage. */
5325 needed
= args_size
.constant
;
5327 /* Since we will be writing into the entire argument area, the
5328 map must be allocated for its entire size, not just the part that
5329 is the responsibility of the caller. */
5330 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl
? fntype
: TREE_TYPE (fndecl
))))
5331 needed
+= reg_parm_stack_space
;
5333 poly_int64 limit
= needed
;
5334 if (ARGS_GROW_DOWNWARD
)
5337 /* For polynomial sizes, this is the maximum possible size needed
5338 for arguments with a constant size and offset. */
5339 HOST_WIDE_INT const_limit
= constant_lower_bound (limit
);
5340 highest_outgoing_arg_in_use
= MAX (initial_highest_arg_in_use
,
5343 stack_usage_map_buf
= XNEWVEC (char, highest_outgoing_arg_in_use
);
5344 stack_usage_map
= stack_usage_map_buf
;
5346 if (initial_highest_arg_in_use
)
5347 memcpy (stack_usage_map
, initial_stack_usage_map
,
5348 initial_highest_arg_in_use
);
5350 if (initial_highest_arg_in_use
!= highest_outgoing_arg_in_use
)
5351 memset (&stack_usage_map
[initial_highest_arg_in_use
], 0,
5352 highest_outgoing_arg_in_use
- initial_highest_arg_in_use
);
5355 /* We must be careful to use virtual regs before they're instantiated,
5356 and real regs afterwards. Loop optimization, for example, can create
5357 new libcalls after we've instantiated the virtual regs, and if we
5358 use virtuals anyway, they won't match the rtl patterns. */
5360 if (virtuals_instantiated
)
5361 argblock
= plus_constant (Pmode
, stack_pointer_rtx
,
5362 STACK_POINTER_OFFSET
);
5364 argblock
= virtual_outgoing_args_rtx
;
5369 argblock
= push_block (gen_int_mode (args_size
.constant
, Pmode
), 0, 0);
5372 /* We push args individually in reverse order, perform stack alignment
5373 before the first push (the last arg). */
5375 anti_adjust_stack (gen_int_mode (args_size
.constant
5376 - original_args_size
.constant
,
5381 #ifdef REG_PARM_STACK_SPACE
5382 if (ACCUMULATE_OUTGOING_ARGS
)
5384 /* The argument list is the property of the called routine and it
5385 may clobber it. If the fixed area has been used for previous
5386 parameters, we must save and restore it. */
5387 save_area
= save_fixed_argument_area (reg_parm_stack_space
, argblock
,
5388 &low_to_save
, &high_to_save
);
5392 /* When expanding a normal call, args are stored in push order,
5393 which is the reverse of what we have here. */
5394 bool any_regs
= false;
5395 for (int i
= nargs
; i
-- > 0; )
5396 if (argvec
[i
].reg
!= NULL_RTX
)
5398 targetm
.calls
.call_args (argvec
[i
].reg
, NULL_TREE
);
5402 targetm
.calls
.call_args (pc_rtx
, NULL_TREE
);
5404 /* Push the args that need to be pushed. */
5406 have_push_fusage
= false;
5408 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
5409 are to be pushed. */
5410 for (count
= 0; count
< nargs
; count
++, argnum
--)
5412 machine_mode mode
= argvec
[argnum
].mode
;
5413 rtx val
= argvec
[argnum
].value
;
5414 rtx reg
= argvec
[argnum
].reg
;
5415 int partial
= argvec
[argnum
].partial
;
5416 unsigned int parm_align
= argvec
[argnum
].locate
.boundary
;
5417 poly_int64 lower_bound
= 0, upper_bound
= 0;
5419 if (! (reg
!= 0 && partial
== 0))
5423 if (ACCUMULATE_OUTGOING_ARGS
)
5425 /* If this is being stored into a pre-allocated, fixed-size,
5426 stack area, save any previous data at that location. */
5428 if (ARGS_GROW_DOWNWARD
)
5430 /* stack_slot is negative, but we want to index stack_usage_map
5431 with positive values. */
5432 upper_bound
= -argvec
[argnum
].locate
.slot_offset
.constant
+ 1;
5433 lower_bound
= upper_bound
- argvec
[argnum
].locate
.size
.constant
;
5437 lower_bound
= argvec
[argnum
].locate
.slot_offset
.constant
;
5438 upper_bound
= lower_bound
+ argvec
[argnum
].locate
.size
.constant
;
5441 if (stack_region_maybe_used_p (lower_bound
, upper_bound
,
5442 reg_parm_stack_space
))
5444 /* We need to make a save area. */
5446 = argvec
[argnum
].locate
.size
.constant
* BITS_PER_UNIT
;
5447 machine_mode save_mode
5448 = int_mode_for_size (size
, 1).else_blk ();
5450 = plus_constant (Pmode
, argblock
,
5451 argvec
[argnum
].locate
.offset
.constant
);
5453 = gen_rtx_MEM (save_mode
, memory_address (save_mode
, adr
));
5455 if (save_mode
== BLKmode
)
5457 argvec
[argnum
].save_area
5458 = assign_stack_temp (BLKmode
,
5459 argvec
[argnum
].locate
.size
.constant
5462 emit_block_move (validize_mem
5463 (copy_rtx (argvec
[argnum
].save_area
)),
5466 (argvec
[argnum
].locate
.size
.constant
,
5468 BLOCK_OP_CALL_PARM
);
5472 argvec
[argnum
].save_area
= gen_reg_rtx (save_mode
);
5474 emit_move_insn (argvec
[argnum
].save_area
, stack_area
);
5479 emit_push_insn (val
, mode
, NULL_TREE
, NULL_RTX
, parm_align
,
5480 partial
, reg
, 0, argblock
,
5482 (argvec
[argnum
].locate
.offset
.constant
, Pmode
)),
5483 reg_parm_stack_space
,
5484 ARGS_SIZE_RTX (argvec
[argnum
].locate
.alignment_pad
), false);
5486 /* Now mark the segment we just used. */
5487 if (ACCUMULATE_OUTGOING_ARGS
)
5488 mark_stack_region_used (lower_bound
, upper_bound
);
5492 /* Indicate argument access so that alias.c knows that these
5495 use
= plus_constant (Pmode
, argblock
,
5496 argvec
[argnum
].locate
.offset
.constant
);
5497 else if (have_push_fusage
)
5501 /* When arguments are pushed, trying to tell alias.c where
5502 exactly this argument is won't work, because the
5503 auto-increment causes confusion. So we merely indicate
5504 that we access something with a known mode somewhere on
5506 use
= gen_rtx_PLUS (Pmode
, stack_pointer_rtx
,
5507 gen_rtx_SCRATCH (Pmode
));
5508 have_push_fusage
= true;
5510 use
= gen_rtx_MEM (argvec
[argnum
].mode
, use
);
5511 use
= gen_rtx_USE (VOIDmode
, use
);
5512 call_fusage
= gen_rtx_EXPR_LIST (VOIDmode
, use
, call_fusage
);
5518 fun
= prepare_call_address (NULL
, fun
, NULL
, &call_fusage
, 0, 0);
5520 /* Now load any reg parms into their regs. */
5522 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
5523 are to be pushed. */
5524 for (count
= 0; count
< nargs
; count
++, argnum
--)
5526 machine_mode mode
= argvec
[argnum
].mode
;
5527 rtx val
= argvec
[argnum
].value
;
5528 rtx reg
= argvec
[argnum
].reg
;
5529 int partial
= argvec
[argnum
].partial
;
5531 /* Handle calls that pass values in multiple non-contiguous
5532 locations. The PA64 has examples of this for library calls. */
5533 if (reg
!= 0 && GET_CODE (reg
) == PARALLEL
)
5534 emit_group_load (reg
, val
, NULL_TREE
, GET_MODE_SIZE (mode
));
5535 else if (reg
!= 0 && partial
== 0)
5537 emit_move_insn (reg
, val
);
5538 #ifdef BLOCK_REG_PADDING
5539 poly_int64 size
= GET_MODE_SIZE (argvec
[argnum
].mode
);
5541 /* Copied from load_register_parameters. */
5543 /* Handle case where we have a value that needs shifting
5544 up to the msb. eg. a QImode value and we're padding
5545 upward on a BYTES_BIG_ENDIAN machine. */
5546 if (known_lt (size
, UNITS_PER_WORD
)
5547 && (argvec
[argnum
].locate
.where_pad
5548 == (BYTES_BIG_ENDIAN
? PAD_UPWARD
: PAD_DOWNWARD
)))
5551 poly_int64 shift
= (UNITS_PER_WORD
- size
) * BITS_PER_UNIT
;
5553 /* Assigning REG here rather than a temp makes CALL_FUSAGE
5554 report the whole reg as used. Strictly speaking, the
5555 call only uses SIZE bytes at the msb end, but it doesn't
5556 seem worth generating rtl to say that. */
5557 reg
= gen_rtx_REG (word_mode
, REGNO (reg
));
5558 x
= expand_shift (LSHIFT_EXPR
, word_mode
, reg
, shift
, reg
, 1);
5560 emit_move_insn (reg
, x
);
5568 /* Any regs containing parms remain in use through the call. */
5569 for (count
= 0; count
< nargs
; count
++)
5571 rtx reg
= argvec
[count
].reg
;
5572 if (reg
!= 0 && GET_CODE (reg
) == PARALLEL
)
5573 use_group_regs (&call_fusage
, reg
);
5576 int partial
= argvec
[count
].partial
;
5580 gcc_assert (partial
% UNITS_PER_WORD
== 0);
5581 nregs
= partial
/ UNITS_PER_WORD
;
5582 use_regs (&call_fusage
, REGNO (reg
), nregs
);
5585 use_reg (&call_fusage
, reg
);
5589 /* Pass the function the address in which to return a structure value. */
5590 if (mem_value
!= 0 && struct_value
!= 0 && ! pcc_struct_value
)
5592 emit_move_insn (struct_value
,
5594 force_operand (XEXP (mem_value
, 0),
5596 if (REG_P (struct_value
))
5597 use_reg (&call_fusage
, struct_value
);
5600 /* Don't allow popping to be deferred, since then
5601 cse'ing of library calls could delete a call and leave the pop. */
5603 valreg
= (mem_value
== 0 && outmode
!= VOIDmode
5604 ? hard_libcall_value (outmode
, orgfun
) : NULL_RTX
);
5606 /* Stack must be properly aligned now. */
5607 gcc_assert (multiple_p (stack_pointer_delta
,
5608 PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
));
5610 before_call
= get_last_insn ();
5612 if (flag_callgraph_info
)
5613 record_final_call (SYMBOL_REF_DECL (orgfun
), UNKNOWN_LOCATION
);
5615 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
5616 will set inhibit_defer_pop to that value. */
5617 /* The return type is needed to decide how many bytes the function pops.
5618 Signedness plays no role in that, so for simplicity, we pretend it's
5619 always signed. We also assume that the list of arguments passed has
5620 no impact, so we pretend it is unknown. */
5622 emit_call_1 (fun
, NULL
,
5623 get_identifier (XSTR (orgfun
, 0)),
5624 build_function_type (tfom
, NULL_TREE
),
5625 original_args_size
.constant
, args_size
.constant
,
5627 targetm
.calls
.function_arg (args_so_far
,
5628 function_arg_info::end_marker ()),
5630 old_inhibit_defer_pop
+ 1, call_fusage
, flags
, args_so_far
);
5635 gcc_assert (GET_CODE (datum
) == SYMBOL_REF
);
5636 rtx_call_insn
*last
= last_call_insn ();
5637 add_reg_note (last
, REG_CALL_DECL
, datum
);
5640 /* Right-shift returned value if necessary. */
5641 if (!pcc_struct_value
5642 && TYPE_MODE (tfom
) != BLKmode
5643 && targetm
.calls
.return_in_msb (tfom
))
5645 shift_return_value (TYPE_MODE (tfom
), false, valreg
);
5646 valreg
= gen_rtx_REG (TYPE_MODE (tfom
), REGNO (valreg
));
5649 targetm
.calls
.end_call_args ();
5651 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
5652 that it should complain if nonvolatile values are live. For
5653 functions that cannot return, inform flow that control does not
5655 if (flags
& ECF_NORETURN
)
5657 /* The barrier note must be emitted
5658 immediately after the CALL_INSN. Some ports emit more than
5659 just a CALL_INSN above, so we must search for it here. */
5660 rtx_insn
*last
= get_last_insn ();
5661 while (!CALL_P (last
))
5663 last
= PREV_INSN (last
);
5664 /* There was no CALL_INSN? */
5665 gcc_assert (last
!= before_call
);
5668 emit_barrier_after (last
);
5671 /* Consider that "regular" libcalls, i.e. all of them except for LCT_THROW
5672 and LCT_RETURNS_TWICE, cannot perform non-local gotos. */
5673 if (flags
& ECF_NOTHROW
)
5675 rtx_insn
*last
= get_last_insn ();
5676 while (!CALL_P (last
))
5678 last
= PREV_INSN (last
);
5679 /* There was no CALL_INSN? */
5680 gcc_assert (last
!= before_call
);
5683 make_reg_eh_region_note_nothrow_nononlocal (last
);
5686 /* Now restore inhibit_defer_pop to its actual original value. */
5691 /* Copy the value to the right place. */
5692 if (outmode
!= VOIDmode
&& retval
)
5698 if (value
!= mem_value
)
5699 emit_move_insn (value
, mem_value
);
5701 else if (GET_CODE (valreg
) == PARALLEL
)
5704 value
= gen_reg_rtx (outmode
);
5705 emit_group_store (value
, valreg
, NULL_TREE
, GET_MODE_SIZE (outmode
));
5709 /* Convert to the proper mode if a promotion has been active. */
5710 if (GET_MODE (valreg
) != outmode
)
5712 int unsignedp
= TYPE_UNSIGNED (tfom
);
5714 gcc_assert (promote_function_mode (tfom
, outmode
, &unsignedp
,
5715 fndecl
? TREE_TYPE (fndecl
) : fntype
, 1)
5716 == GET_MODE (valreg
));
5717 valreg
= convert_modes (outmode
, GET_MODE (valreg
), valreg
, 0);
5721 emit_move_insn (value
, valreg
);
5727 if (ACCUMULATE_OUTGOING_ARGS
)
5729 #ifdef REG_PARM_STACK_SPACE
5731 restore_fixed_argument_area (save_area
, argblock
,
5732 high_to_save
, low_to_save
);
5735 /* If we saved any argument areas, restore them. */
5736 for (count
= 0; count
< nargs
; count
++)
5737 if (argvec
[count
].save_area
)
5739 machine_mode save_mode
= GET_MODE (argvec
[count
].save_area
);
5740 rtx adr
= plus_constant (Pmode
, argblock
,
5741 argvec
[count
].locate
.offset
.constant
);
5742 rtx stack_area
= gen_rtx_MEM (save_mode
,
5743 memory_address (save_mode
, adr
));
5745 if (save_mode
== BLKmode
)
5746 emit_block_move (stack_area
,
5748 (copy_rtx (argvec
[count
].save_area
)),
5750 (argvec
[count
].locate
.size
.constant
, Pmode
)),
5751 BLOCK_OP_CALL_PARM
);
5753 emit_move_insn (stack_area
, argvec
[count
].save_area
);
5756 highest_outgoing_arg_in_use
= initial_highest_arg_in_use
;
5757 stack_usage_map
= initial_stack_usage_map
;
5758 stack_usage_watermark
= initial_stack_usage_watermark
;
5761 free (stack_usage_map_buf
);
5768 /* Store a single argument for a function call
5769 into the register or memory area where it must be passed.
5770 *ARG describes the argument value and where to pass it.
5772 ARGBLOCK is the address of the stack-block for all the arguments,
5773 or 0 on a machine where arguments are pushed individually.
5775 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
5776 so must be careful about how the stack is used.
5778 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
5779 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
5780 that we need not worry about saving and restoring the stack.
5782 FNDECL is the declaration of the function we are calling.
5784 Return nonzero if this arg should cause sibcall failure,
5788 store_one_arg (struct arg_data
*arg
, rtx argblock
, int flags
,
5789 int variable_size ATTRIBUTE_UNUSED
, int reg_parm_stack_space
)
5791 tree pval
= arg
->tree_value
;
5794 poly_int64 used
= 0;
5795 poly_int64 lower_bound
= 0, upper_bound
= 0;
5796 int sibcall_failure
= 0;
5798 if (TREE_CODE (pval
) == ERROR_MARK
)
5801 /* Push a new temporary level for any temporaries we make for
5805 if (ACCUMULATE_OUTGOING_ARGS
&& !(flags
& ECF_SIBCALL
))
5807 /* If this is being stored into a pre-allocated, fixed-size, stack area,
5808 save any previous data at that location. */
5809 if (argblock
&& ! variable_size
&& arg
->stack
)
5811 if (ARGS_GROW_DOWNWARD
)
5813 /* stack_slot is negative, but we want to index stack_usage_map
5814 with positive values. */
5815 if (GET_CODE (XEXP (arg
->stack_slot
, 0)) == PLUS
)
5817 rtx offset
= XEXP (XEXP (arg
->stack_slot
, 0), 1);
5818 upper_bound
= -rtx_to_poly_int64 (offset
) + 1;
5823 lower_bound
= upper_bound
- arg
->locate
.size
.constant
;
5827 if (GET_CODE (XEXP (arg
->stack_slot
, 0)) == PLUS
)
5829 rtx offset
= XEXP (XEXP (arg
->stack_slot
, 0), 1);
5830 lower_bound
= rtx_to_poly_int64 (offset
);
5835 upper_bound
= lower_bound
+ arg
->locate
.size
.constant
;
5838 if (stack_region_maybe_used_p (lower_bound
, upper_bound
,
5839 reg_parm_stack_space
))
5841 /* We need to make a save area. */
5842 poly_uint64 size
= arg
->locate
.size
.constant
* BITS_PER_UNIT
;
5843 machine_mode save_mode
5844 = int_mode_for_size (size
, 1).else_blk ();
5845 rtx adr
= memory_address (save_mode
, XEXP (arg
->stack_slot
, 0));
5846 rtx stack_area
= gen_rtx_MEM (save_mode
, adr
);
5848 if (save_mode
== BLKmode
)
5851 = assign_temp (TREE_TYPE (arg
->tree_value
), 1, 1);
5852 preserve_temp_slots (arg
->save_area
);
5853 emit_block_move (validize_mem (copy_rtx (arg
->save_area
)),
5856 (arg
->locate
.size
.constant
, Pmode
)),
5857 BLOCK_OP_CALL_PARM
);
5861 arg
->save_area
= gen_reg_rtx (save_mode
);
5862 emit_move_insn (arg
->save_area
, stack_area
);
5868 /* If this isn't going to be placed on both the stack and in registers,
5869 set up the register and number of words. */
5870 if (! arg
->pass_on_stack
)
5872 if (flags
& ECF_SIBCALL
)
5873 reg
= arg
->tail_call_reg
;
5876 partial
= arg
->partial
;
5879 /* Being passed entirely in a register. We shouldn't be called in
5881 gcc_assert (reg
== 0 || partial
!= 0);
5883 /* If this arg needs special alignment, don't load the registers
5885 if (arg
->n_aligned_regs
!= 0)
5888 /* If this is being passed partially in a register, we can't evaluate
5889 it directly into its stack slot. Otherwise, we can. */
5890 if (arg
->value
== 0)
5892 /* stack_arg_under_construction is nonzero if a function argument is
5893 being evaluated directly into the outgoing argument list and
5894 expand_call must take special action to preserve the argument list
5895 if it is called recursively.
5897 For scalar function arguments stack_usage_map is sufficient to
5898 determine which stack slots must be saved and restored. Scalar
5899 arguments in general have pass_on_stack == 0.
5901 If this argument is initialized by a function which takes the
5902 address of the argument (a C++ constructor or a C function
5903 returning a BLKmode structure), then stack_usage_map is
5904 insufficient and expand_call must push the stack around the
5905 function call. Such arguments have pass_on_stack == 1.
5907 Note that it is always safe to set stack_arg_under_construction,
5908 but this generates suboptimal code if set when not needed. */
5910 if (arg
->pass_on_stack
)
5911 stack_arg_under_construction
++;
5913 arg
->value
= expand_expr (pval
,
5915 || TYPE_MODE (TREE_TYPE (pval
)) != arg
->mode
)
5916 ? NULL_RTX
: arg
->stack
,
5917 VOIDmode
, EXPAND_STACK_PARM
);
5919 /* If we are promoting object (or for any other reason) the mode
5920 doesn't agree, convert the mode. */
5922 if (arg
->mode
!= TYPE_MODE (TREE_TYPE (pval
)))
5923 arg
->value
= convert_modes (arg
->mode
, TYPE_MODE (TREE_TYPE (pval
)),
5924 arg
->value
, arg
->unsignedp
);
5926 if (arg
->pass_on_stack
)
5927 stack_arg_under_construction
--;
5930 /* Check for overlap with already clobbered argument area. */
5931 if ((flags
& ECF_SIBCALL
)
5932 && MEM_P (arg
->value
)
5933 && mem_might_overlap_already_clobbered_arg_p (XEXP (arg
->value
, 0),
5934 arg
->locate
.size
.constant
))
5935 sibcall_failure
= 1;
5937 /* Don't allow anything left on stack from computation
5938 of argument to alloca. */
5939 if (flags
& ECF_MAY_BE_ALLOCA
)
5940 do_pending_stack_adjust ();
5942 if (arg
->value
== arg
->stack
)
5943 /* If the value is already in the stack slot, we are done. */
5945 else if (arg
->mode
!= BLKmode
)
5947 unsigned int parm_align
;
5949 /* Argument is a scalar, not entirely passed in registers.
5950 (If part is passed in registers, arg->partial says how much
5951 and emit_push_insn will take care of putting it there.)
5953 Push it, and if its size is less than the
5954 amount of space allocated to it,
5955 also bump stack pointer by the additional space.
5956 Note that in C the default argument promotions
5957 will prevent such mismatches. */
5959 poly_int64 size
= (TYPE_EMPTY_P (TREE_TYPE (pval
))
5960 ? 0 : GET_MODE_SIZE (arg
->mode
));
5962 /* Compute how much space the push instruction will push.
5963 On many machines, pushing a byte will advance the stack
5964 pointer by a halfword. */
5965 #ifdef PUSH_ROUNDING
5966 size
= PUSH_ROUNDING (size
);
5970 /* Compute how much space the argument should get:
5971 round up to a multiple of the alignment for arguments. */
5972 if (targetm
.calls
.function_arg_padding (arg
->mode
, TREE_TYPE (pval
))
5974 /* At the moment we don't (need to) support ABIs for which the
5975 padding isn't known at compile time. In principle it should
5976 be easy to add though. */
5977 used
= force_align_up (size
, PARM_BOUNDARY
/ BITS_PER_UNIT
);
5979 /* Compute the alignment of the pushed argument. */
5980 parm_align
= arg
->locate
.boundary
;
5981 if (targetm
.calls
.function_arg_padding (arg
->mode
, TREE_TYPE (pval
))
5984 poly_int64 pad
= used
- size
;
5985 unsigned int pad_align
= known_alignment (pad
) * BITS_PER_UNIT
;
5987 parm_align
= MIN (parm_align
, pad_align
);
5990 /* This isn't already where we want it on the stack, so put it there.
5991 This can either be done with push or copy insns. */
5992 if (maybe_ne (used
, 0)
5993 && !emit_push_insn (arg
->value
, arg
->mode
, TREE_TYPE (pval
),
5994 NULL_RTX
, parm_align
, partial
, reg
, used
- size
,
5995 argblock
, ARGS_SIZE_RTX (arg
->locate
.offset
),
5996 reg_parm_stack_space
,
5997 ARGS_SIZE_RTX (arg
->locate
.alignment_pad
), true))
5998 sibcall_failure
= 1;
6000 /* Unless this is a partially-in-register argument, the argument is now
6003 arg
->value
= arg
->stack
;
6007 /* BLKmode, at least partly to be pushed. */
6009 unsigned int parm_align
;
6013 /* Pushing a nonscalar.
6014 If part is passed in registers, PARTIAL says how much
6015 and emit_push_insn will take care of putting it there. */
6017 /* Round its size up to a multiple
6018 of the allocation unit for arguments. */
6020 if (arg
->locate
.size
.var
!= 0)
6023 size_rtx
= ARGS_SIZE_RTX (arg
->locate
.size
);
6027 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
6028 for BLKmode is careful to avoid it. */
6029 excess
= (arg
->locate
.size
.constant
6030 - arg_int_size_in_bytes (TREE_TYPE (pval
))
6032 size_rtx
= expand_expr (arg_size_in_bytes (TREE_TYPE (pval
)),
6033 NULL_RTX
, TYPE_MODE (sizetype
),
6037 parm_align
= arg
->locate
.boundary
;
6039 /* When an argument is padded down, the block is aligned to
6040 PARM_BOUNDARY, but the actual argument isn't. */
6041 if (targetm
.calls
.function_arg_padding (arg
->mode
, TREE_TYPE (pval
))
6044 if (arg
->locate
.size
.var
)
6045 parm_align
= BITS_PER_UNIT
;
6048 unsigned int excess_align
6049 = known_alignment (excess
) * BITS_PER_UNIT
;
6050 if (excess_align
!= 0)
6051 parm_align
= MIN (parm_align
, excess_align
);
6055 if ((flags
& ECF_SIBCALL
) && MEM_P (arg
->value
))
6057 /* emit_push_insn might not work properly if arg->value and
6058 argblock + arg->locate.offset areas overlap. */
6062 if (strip_offset (XEXP (x
, 0), &i
)
6063 == crtl
->args
.internal_arg_pointer
)
6065 /* arg.locate doesn't contain the pretend_args_size offset,
6066 it's part of argblock. Ensure we don't count it in I. */
6067 if (STACK_GROWS_DOWNWARD
)
6068 i
-= crtl
->args
.pretend_args_size
;
6070 i
+= crtl
->args
.pretend_args_size
;
6072 /* expand_call should ensure this. */
6073 gcc_assert (!arg
->locate
.offset
.var
6074 && arg
->locate
.size
.var
== 0);
6075 poly_int64 size_val
= rtx_to_poly_int64 (size_rtx
);
6077 if (known_eq (arg
->locate
.offset
.constant
, i
))
6079 /* Even though they appear to be at the same location,
6080 if part of the outgoing argument is in registers,
6081 they aren't really at the same location. Check for
6082 this by making sure that the incoming size is the
6083 same as the outgoing size. */
6084 if (maybe_ne (arg
->locate
.size
.constant
, size_val
))
6085 sibcall_failure
= 1;
6087 else if (maybe_in_range_p (arg
->locate
.offset
.constant
,
6089 sibcall_failure
= 1;
6090 /* Use arg->locate.size.constant instead of size_rtx
6091 because we only care about the part of the argument
6093 else if (maybe_in_range_p (i
, arg
->locate
.offset
.constant
,
6094 arg
->locate
.size
.constant
))
6095 sibcall_failure
= 1;
6099 if (!CONST_INT_P (size_rtx
) || INTVAL (size_rtx
) != 0)
6100 emit_push_insn (arg
->value
, arg
->mode
, TREE_TYPE (pval
), size_rtx
,
6101 parm_align
, partial
, reg
, excess
, argblock
,
6102 ARGS_SIZE_RTX (arg
->locate
.offset
),
6103 reg_parm_stack_space
,
6104 ARGS_SIZE_RTX (arg
->locate
.alignment_pad
), false);
6106 /* Unless this is a partially-in-register argument, the argument is now
6109 ??? Unlike the case above, in which we want the actual
6110 address of the data, so that we can load it directly into a
6111 register, here we want the address of the stack slot, so that
6112 it's properly aligned for word-by-word copying or something
6113 like that. It's not clear that this is always correct. */
6115 arg
->value
= arg
->stack_slot
;
6118 if (arg
->reg
&& GET_CODE (arg
->reg
) == PARALLEL
)
6120 tree type
= TREE_TYPE (arg
->tree_value
);
6122 = emit_group_load_into_temps (arg
->reg
, arg
->value
, type
,
6123 int_size_in_bytes (type
));
6126 /* Mark all slots this store used. */
6127 if (ACCUMULATE_OUTGOING_ARGS
&& !(flags
& ECF_SIBCALL
)
6128 && argblock
&& ! variable_size
&& arg
->stack
)
6129 mark_stack_region_used (lower_bound
, upper_bound
);
6131 /* Once we have pushed something, pops can't safely
6132 be deferred during the rest of the arguments. */
6135 /* Free any temporary slots made in processing this argument. */
6138 return sibcall_failure
;
6141 /* Nonzero if we do not know how to pass ARG solely in registers. */
6144 must_pass_in_stack_var_size (const function_arg_info
&arg
)
6149 /* If the type has variable size... */
6150 if (!poly_int_tree_p (TYPE_SIZE (arg
.type
)))
6153 /* If the type is marked as addressable (it is required
6154 to be constructed into the stack)... */
6155 if (TREE_ADDRESSABLE (arg
.type
))
6161 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
6162 takes trailing padding of a structure into account. */
6163 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
6166 must_pass_in_stack_var_size_or_pad (const function_arg_info
&arg
)
6171 /* If the type has variable size... */
6172 if (TREE_CODE (TYPE_SIZE (arg
.type
)) != INTEGER_CST
)
6175 /* If the type is marked as addressable (it is required
6176 to be constructed into the stack)... */
6177 if (TREE_ADDRESSABLE (arg
.type
))
6180 if (TYPE_EMPTY_P (arg
.type
))
6183 /* If the padding and mode of the type is such that a copy into
6184 a register would put it into the wrong part of the register. */
6185 if (arg
.mode
== BLKmode
6186 && int_size_in_bytes (arg
.type
) % (PARM_BOUNDARY
/ BITS_PER_UNIT
)
6187 && (targetm
.calls
.function_arg_padding (arg
.mode
, arg
.type
)
6188 == (BYTES_BIG_ENDIAN
? PAD_UPWARD
: PAD_DOWNWARD
)))
6194 /* Return true if TYPE must be passed on the stack when passed to
6195 the "..." arguments of a function. */
6198 must_pass_va_arg_in_stack (tree type
)
6200 function_arg_info
arg (type
, /*named=*/false);
6201 return targetm
.calls
.must_pass_in_stack (arg
);
6204 /* Return true if FIELD is the C++17 empty base field that should
6205 be ignored for ABI calling convention decisions in order to
6206 maintain ABI compatibility between C++14 and earlier, which doesn't
6207 add this FIELD to classes with empty bases, and C++17 and later
6211 cxx17_empty_base_field_p (const_tree field
)
6213 return (DECL_FIELD_ABI_IGNORED (field
)
6214 && DECL_ARTIFICIAL (field
)
6215 && RECORD_OR_UNION_TYPE_P (TREE_TYPE (field
))
6216 && !lookup_attribute ("no_unique_address", DECL_ATTRIBUTES (field
)));
6219 /* Tell the garbage collector about GTY markers in this source file. */
6220 #include "gt-calls.h"