1 /* Convert function calls to rtl insns, for GNU C compiler.
2 Copyright (C) 1989-2018 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"
57 #include "gimple-fold.h"
59 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
60 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
62 /* Data structure and subroutines used within expand_call. */
66 /* Tree node for this argument. */
68 /* Mode for value; TYPE_MODE unless promoted. */
70 /* Current RTL value for argument, or 0 if it isn't precomputed. */
72 /* Initially-compute RTL value for argument; only for const functions. */
74 /* Register to pass this argument in, 0 if passed on stack, or an
75 PARALLEL if the arg is to be copied into multiple non-contiguous
78 /* Register to pass this argument in when generating tail call sequence.
79 This is not the same register as for normal calls on machines with
82 /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct
83 form for emit_group_move. */
85 /* If value is passed in neither reg nor stack, this field holds a number
86 of a special slot to be used. */
88 /* For pointer bounds hold an index of parm bounds are bound to. -1 if
89 there is no such pointer. */
91 /* If pointer_arg refers a structure, then pointer_offset holds an offset
92 of a pointer in this structure. */
94 /* If REG was promoted from the actual mode of the argument expression,
95 indicates whether the promotion is sign- or zero-extended. */
97 /* Number of bytes to put in registers. 0 means put the whole arg
98 in registers. Also 0 if not passed in registers. */
100 /* Nonzero if argument must be passed on stack.
101 Note that some arguments may be passed on the stack
102 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
103 pass_on_stack identifies arguments that *cannot* go in registers. */
105 /* Some fields packaged up for locate_and_pad_parm. */
106 struct locate_and_pad_arg_data locate
;
107 /* Location on the stack at which parameter should be stored. The store
108 has already been done if STACK == VALUE. */
110 /* Location on the stack of the start of this argument slot. This can
111 differ from STACK if this arg pads downward. This location is known
112 to be aligned to TARGET_FUNCTION_ARG_BOUNDARY. */
114 /* Place that this stack area has been saved, if needed. */
116 /* If an argument's alignment does not permit direct copying into registers,
117 copy in smaller-sized pieces into pseudos. These are stored in a
118 block pointed to by this field. The next field says how many
119 word-sized pseudos we made. */
124 /* A vector of one char per byte of stack space. A byte if nonzero if
125 the corresponding stack location has been used.
126 This vector is used to prevent a function call within an argument from
127 clobbering any stack already set up. */
128 static char *stack_usage_map
;
130 /* Size of STACK_USAGE_MAP. */
131 static unsigned int highest_outgoing_arg_in_use
;
133 /* Assume that any stack location at this byte index is used,
134 without checking the contents of stack_usage_map. */
135 static unsigned HOST_WIDE_INT stack_usage_watermark
= HOST_WIDE_INT_M1U
;
137 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
138 stack location's tail call argument has been already stored into the stack.
139 This bitmap is used to prevent sibling call optimization if function tries
140 to use parent's incoming argument slots when they have been already
141 overwritten with tail call arguments. */
142 static sbitmap stored_args_map
;
144 /* Assume that any virtual-incoming location at this byte index has been
145 stored, without checking the contents of stored_args_map. */
146 static unsigned HOST_WIDE_INT stored_args_watermark
;
148 /* stack_arg_under_construction is nonzero when an argument may be
149 initialized with a constructor call (including a C function that
150 returns a BLKmode struct) and expand_call must take special action
151 to make sure the object being constructed does not overlap the
152 argument list for the constructor call. */
153 static int stack_arg_under_construction
;
155 static void precompute_register_parameters (int, struct arg_data
*, int *);
156 static int store_one_arg (struct arg_data
*, rtx
, int, int, int);
157 static void store_unaligned_arguments_into_pseudos (struct arg_data
*, int);
158 static int finalize_must_preallocate (int, int, struct arg_data
*,
160 static void precompute_arguments (int, struct arg_data
*);
161 static void compute_argument_addresses (struct arg_data
*, rtx
, int);
162 static rtx
rtx_for_function_call (tree
, tree
);
163 static void load_register_parameters (struct arg_data
*, int, rtx
*, int,
165 static int special_function_p (const_tree
, int);
166 static int check_sibcall_argument_overlap_1 (rtx
);
167 static int check_sibcall_argument_overlap (rtx_insn
*, struct arg_data
*, int);
169 static tree
split_complex_types (tree
);
171 #ifdef REG_PARM_STACK_SPACE
172 static rtx
save_fixed_argument_area (int, rtx
, int *, int *);
173 static void restore_fixed_argument_area (rtx
, rtx
, int, int);
176 /* Return true if bytes [LOWER_BOUND, UPPER_BOUND) of the outgoing
177 stack region might already be in use. */
180 stack_region_maybe_used_p (poly_uint64 lower_bound
, poly_uint64 upper_bound
,
181 unsigned int reg_parm_stack_space
)
183 unsigned HOST_WIDE_INT const_lower
, const_upper
;
184 const_lower
= constant_lower_bound (lower_bound
);
185 if (!upper_bound
.is_constant (&const_upper
))
186 const_upper
= HOST_WIDE_INT_M1U
;
188 if (const_upper
> stack_usage_watermark
)
191 /* Don't worry about things in the fixed argument area;
192 it has already been saved. */
193 const_lower
= MAX (const_lower
, reg_parm_stack_space
);
194 const_upper
= MIN (const_upper
, highest_outgoing_arg_in_use
);
195 for (unsigned HOST_WIDE_INT i
= const_lower
; i
< const_upper
; ++i
)
196 if (stack_usage_map
[i
])
201 /* Record that bytes [LOWER_BOUND, UPPER_BOUND) of the outgoing
202 stack region are now in use. */
205 mark_stack_region_used (poly_uint64 lower_bound
, poly_uint64 upper_bound
)
207 unsigned HOST_WIDE_INT const_lower
, const_upper
;
208 const_lower
= constant_lower_bound (lower_bound
);
209 if (upper_bound
.is_constant (&const_upper
))
210 for (unsigned HOST_WIDE_INT i
= const_lower
; i
< const_upper
; ++i
)
211 stack_usage_map
[i
] = 1;
213 stack_usage_watermark
= MIN (stack_usage_watermark
, const_lower
);
216 /* Force FUNEXP into a form suitable for the address of a CALL,
217 and return that as an rtx. Also load the static chain register
218 if FNDECL is a nested function.
220 CALL_FUSAGE points to a variable holding the prospective
221 CALL_INSN_FUNCTION_USAGE information. */
224 prepare_call_address (tree fndecl_or_type
, rtx funexp
, rtx static_chain_value
,
225 rtx
*call_fusage
, int reg_parm_seen
, int flags
)
227 /* Make a valid memory address and copy constants through pseudo-regs,
228 but not for a constant address if -fno-function-cse. */
229 if (GET_CODE (funexp
) != SYMBOL_REF
)
231 /* If it's an indirect call by descriptor, generate code to perform
232 runtime identification of the pointer and load the descriptor. */
233 if ((flags
& ECF_BY_DESCRIPTOR
) && !flag_trampolines
)
235 const int bit_val
= targetm
.calls
.custom_function_descriptors
;
236 rtx call_lab
= gen_label_rtx ();
238 gcc_assert (fndecl_or_type
&& TYPE_P (fndecl_or_type
));
240 = build_decl (UNKNOWN_LOCATION
, FUNCTION_DECL
, NULL_TREE
,
242 DECL_STATIC_CHAIN (fndecl_or_type
) = 1;
243 rtx chain
= targetm
.calls
.static_chain (fndecl_or_type
, false);
245 if (GET_MODE (funexp
) != Pmode
)
246 funexp
= convert_memory_address (Pmode
, funexp
);
248 /* Avoid long live ranges around function calls. */
249 funexp
= copy_to_mode_reg (Pmode
, funexp
);
252 emit_insn (gen_rtx_CLOBBER (VOIDmode
, chain
));
254 /* Emit the runtime identification pattern. */
255 rtx mask
= gen_rtx_AND (Pmode
, funexp
, GEN_INT (bit_val
));
256 emit_cmp_and_jump_insns (mask
, const0_rtx
, EQ
, NULL_RTX
, Pmode
, 1,
259 /* Statically predict the branch to very likely taken. */
260 rtx_insn
*insn
= get_last_insn ();
262 predict_insn_def (insn
, PRED_BUILTIN_EXPECT
, TAKEN
);
264 /* Load the descriptor. */
265 rtx mem
= gen_rtx_MEM (ptr_mode
,
266 plus_constant (Pmode
, funexp
, - bit_val
));
267 MEM_NOTRAP_P (mem
) = 1;
268 mem
= convert_memory_address (Pmode
, mem
);
269 emit_move_insn (chain
, mem
);
271 mem
= gen_rtx_MEM (ptr_mode
,
272 plus_constant (Pmode
, funexp
,
273 POINTER_SIZE
/ BITS_PER_UNIT
275 MEM_NOTRAP_P (mem
) = 1;
276 mem
= convert_memory_address (Pmode
, mem
);
277 emit_move_insn (funexp
, mem
);
279 emit_label (call_lab
);
283 use_reg (call_fusage
, chain
);
284 STATIC_CHAIN_REG_P (chain
) = 1;
287 /* Make sure we're not going to be overwritten below. */
288 gcc_assert (!static_chain_value
);
291 /* If we are using registers for parameters, force the
292 function address into a register now. */
293 funexp
= ((reg_parm_seen
294 && targetm
.small_register_classes_for_mode_p (FUNCTION_MODE
))
295 ? force_not_mem (memory_address (FUNCTION_MODE
, funexp
))
296 : memory_address (FUNCTION_MODE
, funexp
));
300 /* funexp could be a SYMBOL_REF represents a function pointer which is
301 of ptr_mode. In this case, it should be converted into address mode
302 to be a valid address for memory rtx pattern. See PR 64971. */
303 if (GET_MODE (funexp
) != Pmode
)
304 funexp
= convert_memory_address (Pmode
, funexp
);
306 if (!(flags
& ECF_SIBCALL
))
308 if (!NO_FUNCTION_CSE
&& optimize
&& ! flag_no_function_cse
)
309 funexp
= force_reg (Pmode
, funexp
);
313 if (static_chain_value
!= 0
314 && (TREE_CODE (fndecl_or_type
) != FUNCTION_DECL
315 || DECL_STATIC_CHAIN (fndecl_or_type
)))
319 chain
= targetm
.calls
.static_chain (fndecl_or_type
, false);
320 static_chain_value
= convert_memory_address (Pmode
, static_chain_value
);
322 emit_move_insn (chain
, static_chain_value
);
325 use_reg (call_fusage
, chain
);
326 STATIC_CHAIN_REG_P (chain
) = 1;
333 /* Generate instructions to call function FUNEXP,
334 and optionally pop the results.
335 The CALL_INSN is the first insn generated.
337 FNDECL is the declaration node of the function. This is given to the
338 hook TARGET_RETURN_POPS_ARGS to determine whether this function pops
341 FUNTYPE is the data type of the function. This is given to the hook
342 TARGET_RETURN_POPS_ARGS to determine whether this function pops its
343 own args. We used to allow an identifier for library functions, but
344 that doesn't work when the return type is an aggregate type and the
345 calling convention says that the pointer to this aggregate is to be
346 popped by the callee.
348 STACK_SIZE is the number of bytes of arguments on the stack,
349 ROUNDED_STACK_SIZE is that number rounded up to
350 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
351 both to put into the call insn and to generate explicit popping
354 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
355 It is zero if this call doesn't want a structure value.
357 NEXT_ARG_REG is the rtx that results from executing
358 targetm.calls.function_arg (&args_so_far, VOIDmode, void_type_node, true)
359 just after all the args have had their registers assigned.
360 This could be whatever you like, but normally it is the first
361 arg-register beyond those used for args in this call,
362 or 0 if all the arg-registers are used in this call.
363 It is passed on to `gen_call' so you can put this info in the call insn.
365 VALREG is a hard register in which a value is returned,
366 or 0 if the call does not return a value.
368 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
369 the args to this call were processed.
370 We restore `inhibit_defer_pop' to that value.
372 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
373 denote registers used by the called function. */
376 emit_call_1 (rtx funexp
, tree fntree ATTRIBUTE_UNUSED
, tree fndecl ATTRIBUTE_UNUSED
,
377 tree funtype ATTRIBUTE_UNUSED
,
378 poly_int64 stack_size ATTRIBUTE_UNUSED
,
379 poly_int64 rounded_stack_size
,
380 poly_int64 struct_value_size ATTRIBUTE_UNUSED
,
381 rtx next_arg_reg ATTRIBUTE_UNUSED
, rtx valreg
,
382 int old_inhibit_defer_pop
, rtx call_fusage
, int ecf_flags
,
383 cumulative_args_t args_so_far ATTRIBUTE_UNUSED
)
385 rtx rounded_stack_size_rtx
= gen_int_mode (rounded_stack_size
, Pmode
);
386 rtx call
, funmem
, pat
;
387 int already_popped
= 0;
388 poly_int64 n_popped
= 0;
390 /* Sibling call patterns never pop arguments (no sibcall(_value)_pop
391 patterns exist). Any popping that the callee does on return will
392 be from our caller's frame rather than ours. */
393 if (!(ecf_flags
& ECF_SIBCALL
))
395 n_popped
+= targetm
.calls
.return_pops_args (fndecl
, funtype
, stack_size
);
397 #ifdef CALL_POPS_ARGS
398 n_popped
+= CALL_POPS_ARGS (*get_cumulative_args (args_so_far
));
402 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
403 and we don't want to load it into a register as an optimization,
404 because prepare_call_address already did it if it should be done. */
405 if (GET_CODE (funexp
) != SYMBOL_REF
)
406 funexp
= memory_address (FUNCTION_MODE
, funexp
);
408 funmem
= gen_rtx_MEM (FUNCTION_MODE
, funexp
);
409 if (fndecl
&& TREE_CODE (fndecl
) == FUNCTION_DECL
)
413 /* Although a built-in FUNCTION_DECL and its non-__builtin
414 counterpart compare equal and get a shared mem_attrs, they
415 produce different dump output in compare-debug compilations,
416 if an entry gets garbage collected in one compilation, then
417 adds a different (but equivalent) entry, while the other
418 doesn't run the garbage collector at the same spot and then
419 shares the mem_attr with the equivalent entry. */
420 if (DECL_BUILT_IN_CLASS (t
) == BUILT_IN_NORMAL
)
422 tree t2
= builtin_decl_explicit (DECL_FUNCTION_CODE (t
));
427 set_mem_expr (funmem
, t
);
430 set_mem_expr (funmem
, build_simple_mem_ref (CALL_EXPR_FN (fntree
)));
432 if (ecf_flags
& ECF_SIBCALL
)
435 pat
= targetm
.gen_sibcall_value (valreg
, funmem
,
436 rounded_stack_size_rtx
,
437 next_arg_reg
, NULL_RTX
);
439 pat
= targetm
.gen_sibcall (funmem
, rounded_stack_size_rtx
,
441 gen_int_mode (struct_value_size
, Pmode
));
443 /* If the target has "call" or "call_value" insns, then prefer them
444 if no arguments are actually popped. If the target does not have
445 "call" or "call_value" insns, then we must use the popping versions
446 even if the call has no arguments to pop. */
447 else if (maybe_ne (n_popped
, 0)
449 ? targetm
.have_call_value ()
450 : targetm
.have_call ()))
452 rtx n_pop
= gen_int_mode (n_popped
, Pmode
);
454 /* If this subroutine pops its own args, record that in the call insn
455 if possible, for the sake of frame pointer elimination. */
458 pat
= targetm
.gen_call_value_pop (valreg
, funmem
,
459 rounded_stack_size_rtx
,
460 next_arg_reg
, n_pop
);
462 pat
= targetm
.gen_call_pop (funmem
, rounded_stack_size_rtx
,
463 next_arg_reg
, n_pop
);
470 pat
= targetm
.gen_call_value (valreg
, funmem
, rounded_stack_size_rtx
,
471 next_arg_reg
, NULL_RTX
);
473 pat
= targetm
.gen_call (funmem
, rounded_stack_size_rtx
, next_arg_reg
,
474 gen_int_mode (struct_value_size
, Pmode
));
478 /* Find the call we just emitted. */
479 rtx_call_insn
*call_insn
= last_call_insn ();
481 /* Some target create a fresh MEM instead of reusing the one provided
482 above. Set its MEM_EXPR. */
483 call
= get_call_rtx_from (call_insn
);
485 && MEM_EXPR (XEXP (call
, 0)) == NULL_TREE
486 && MEM_EXPR (funmem
) != NULL_TREE
)
487 set_mem_expr (XEXP (call
, 0), MEM_EXPR (funmem
));
489 /* Put the register usage information there. */
490 add_function_usage_to (call_insn
, call_fusage
);
492 /* If this is a const call, then set the insn's unchanging bit. */
493 if (ecf_flags
& ECF_CONST
)
494 RTL_CONST_CALL_P (call_insn
) = 1;
496 /* If this is a pure call, then set the insn's unchanging bit. */
497 if (ecf_flags
& ECF_PURE
)
498 RTL_PURE_CALL_P (call_insn
) = 1;
500 /* If this is a const call, then set the insn's unchanging bit. */
501 if (ecf_flags
& ECF_LOOPING_CONST_OR_PURE
)
502 RTL_LOOPING_CONST_OR_PURE_CALL_P (call_insn
) = 1;
504 /* Create a nothrow REG_EH_REGION note, if needed. */
505 make_reg_eh_region_note (call_insn
, ecf_flags
, 0);
507 if (ecf_flags
& ECF_NORETURN
)
508 add_reg_note (call_insn
, REG_NORETURN
, const0_rtx
);
510 if (ecf_flags
& ECF_RETURNS_TWICE
)
512 add_reg_note (call_insn
, REG_SETJMP
, const0_rtx
);
513 cfun
->calls_setjmp
= 1;
516 SIBLING_CALL_P (call_insn
) = ((ecf_flags
& ECF_SIBCALL
) != 0);
518 /* Restore this now, so that we do defer pops for this call's args
519 if the context of the call as a whole permits. */
520 inhibit_defer_pop
= old_inhibit_defer_pop
;
522 if (maybe_ne (n_popped
, 0))
525 CALL_INSN_FUNCTION_USAGE (call_insn
)
526 = gen_rtx_EXPR_LIST (VOIDmode
,
527 gen_rtx_CLOBBER (VOIDmode
, stack_pointer_rtx
),
528 CALL_INSN_FUNCTION_USAGE (call_insn
));
529 rounded_stack_size
-= n_popped
;
530 rounded_stack_size_rtx
= gen_int_mode (rounded_stack_size
, Pmode
);
531 stack_pointer_delta
-= n_popped
;
533 add_args_size_note (call_insn
, stack_pointer_delta
);
535 /* If popup is needed, stack realign must use DRAP */
536 if (SUPPORTS_STACK_ALIGNMENT
)
537 crtl
->need_drap
= true;
539 /* For noreturn calls when not accumulating outgoing args force
540 REG_ARGS_SIZE note to prevent crossjumping of calls with different
542 else if (!ACCUMULATE_OUTGOING_ARGS
&& (ecf_flags
& ECF_NORETURN
) != 0)
543 add_args_size_note (call_insn
, stack_pointer_delta
);
545 if (!ACCUMULATE_OUTGOING_ARGS
)
547 /* If returning from the subroutine does not automatically pop the args,
548 we need an instruction to pop them sooner or later.
549 Perhaps do it now; perhaps just record how much space to pop later.
551 If returning from the subroutine does pop the args, indicate that the
552 stack pointer will be changed. */
554 if (maybe_ne (rounded_stack_size
, 0))
556 if (ecf_flags
& ECF_NORETURN
)
557 /* Just pretend we did the pop. */
558 stack_pointer_delta
-= rounded_stack_size
;
559 else if (flag_defer_pop
&& inhibit_defer_pop
== 0
560 && ! (ecf_flags
& (ECF_CONST
| ECF_PURE
)))
561 pending_stack_adjust
+= rounded_stack_size
;
563 adjust_stack (rounded_stack_size_rtx
);
566 /* When we accumulate outgoing args, we must avoid any stack manipulations.
567 Restore the stack pointer to its original value now. Usually
568 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
569 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
570 popping variants of functions exist as well.
572 ??? We may optimize similar to defer_pop above, but it is
573 probably not worthwhile.
575 ??? It will be worthwhile to enable combine_stack_adjustments even for
577 else if (maybe_ne (n_popped
, 0))
578 anti_adjust_stack (gen_int_mode (n_popped
, Pmode
));
581 /* Determine if the function identified by FNDECL is one with
582 special properties we wish to know about. Modify FLAGS accordingly.
584 For example, if the function might return more than one time (setjmp), then
585 set ECF_RETURNS_TWICE.
587 Set ECF_MAY_BE_ALLOCA for any memory allocation function that might allocate
588 space from the stack such as alloca. */
591 special_function_p (const_tree fndecl
, int flags
)
593 tree name_decl
= DECL_NAME (fndecl
);
595 if (fndecl
&& name_decl
596 && IDENTIFIER_LENGTH (name_decl
) <= 11
597 /* Exclude functions not at the file scope, or not `extern',
598 since they are not the magic functions we would otherwise
600 FIXME: this should be handled with attributes, not with this
601 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
602 because you can declare fork() inside a function if you
604 && (DECL_CONTEXT (fndecl
) == NULL_TREE
605 || TREE_CODE (DECL_CONTEXT (fndecl
)) == TRANSLATION_UNIT_DECL
)
606 && TREE_PUBLIC (fndecl
))
608 const char *name
= IDENTIFIER_POINTER (name_decl
);
609 const char *tname
= name
;
611 /* We assume that alloca will always be called by name. It
612 makes no sense to pass it as a pointer-to-function to
613 anything that does not understand its behavior. */
614 if (IDENTIFIER_LENGTH (name_decl
) == 6
616 && ! strcmp (name
, "alloca"))
617 flags
|= ECF_MAY_BE_ALLOCA
;
619 /* Disregard prefix _ or __. */
628 /* ECF_RETURNS_TWICE is safe even for -ffreestanding. */
629 if (! strcmp (tname
, "setjmp")
630 || ! strcmp (tname
, "sigsetjmp")
631 || ! strcmp (name
, "savectx")
632 || ! strcmp (name
, "vfork")
633 || ! strcmp (name
, "getcontext"))
634 flags
|= ECF_RETURNS_TWICE
;
637 if (DECL_BUILT_IN_CLASS (fndecl
) == BUILT_IN_NORMAL
638 && ALLOCA_FUNCTION_CODE_P (DECL_FUNCTION_CODE (fndecl
)))
639 flags
|= ECF_MAY_BE_ALLOCA
;
644 /* Similar to special_function_p; return a set of ERF_ flags for the
647 decl_return_flags (tree fndecl
)
650 tree type
= TREE_TYPE (fndecl
);
654 attr
= lookup_attribute ("fn spec", TYPE_ATTRIBUTES (type
));
658 attr
= TREE_VALUE (TREE_VALUE (attr
));
659 if (!attr
|| TREE_STRING_LENGTH (attr
) < 1)
662 switch (TREE_STRING_POINTER (attr
)[0])
668 return ERF_RETURNS_ARG
| (TREE_STRING_POINTER (attr
)[0] - '1');
679 /* Return nonzero when FNDECL represents a call to setjmp. */
682 setjmp_call_p (const_tree fndecl
)
684 if (DECL_IS_RETURNS_TWICE (fndecl
))
685 return ECF_RETURNS_TWICE
;
686 return special_function_p (fndecl
, 0) & ECF_RETURNS_TWICE
;
690 /* Return true if STMT may be an alloca call. */
693 gimple_maybe_alloca_call_p (const gimple
*stmt
)
697 if (!is_gimple_call (stmt
))
700 fndecl
= gimple_call_fndecl (stmt
);
701 if (fndecl
&& (special_function_p (fndecl
, 0) & ECF_MAY_BE_ALLOCA
))
707 /* Return true if STMT is a builtin alloca call. */
710 gimple_alloca_call_p (const gimple
*stmt
)
714 if (!is_gimple_call (stmt
))
717 fndecl
= gimple_call_fndecl (stmt
);
718 if (fndecl
&& fndecl_built_in_p (fndecl
, BUILT_IN_NORMAL
))
719 switch (DECL_FUNCTION_CODE (fndecl
))
721 CASE_BUILT_IN_ALLOCA
:
722 return gimple_call_num_args (stmt
) > 0;
730 /* Return true when exp contains a builtin alloca call. */
733 alloca_call_p (const_tree exp
)
736 if (TREE_CODE (exp
) == CALL_EXPR
737 && (fndecl
= get_callee_fndecl (exp
))
738 && DECL_BUILT_IN_CLASS (fndecl
) == BUILT_IN_NORMAL
)
739 switch (DECL_FUNCTION_CODE (fndecl
))
741 CASE_BUILT_IN_ALLOCA
:
750 /* Return TRUE if FNDECL is either a TM builtin or a TM cloned
751 function. Return FALSE otherwise. */
754 is_tm_builtin (const_tree fndecl
)
759 if (decl_is_tm_clone (fndecl
))
762 if (DECL_BUILT_IN_CLASS (fndecl
) == BUILT_IN_NORMAL
)
764 switch (DECL_FUNCTION_CODE (fndecl
))
766 case BUILT_IN_TM_COMMIT
:
767 case BUILT_IN_TM_COMMIT_EH
:
768 case BUILT_IN_TM_ABORT
:
769 case BUILT_IN_TM_IRREVOCABLE
:
770 case BUILT_IN_TM_GETTMCLONE_IRR
:
771 case BUILT_IN_TM_MEMCPY
:
772 case BUILT_IN_TM_MEMMOVE
:
773 case BUILT_IN_TM_MEMSET
:
774 CASE_BUILT_IN_TM_STORE (1):
775 CASE_BUILT_IN_TM_STORE (2):
776 CASE_BUILT_IN_TM_STORE (4):
777 CASE_BUILT_IN_TM_STORE (8):
778 CASE_BUILT_IN_TM_STORE (FLOAT
):
779 CASE_BUILT_IN_TM_STORE (DOUBLE
):
780 CASE_BUILT_IN_TM_STORE (LDOUBLE
):
781 CASE_BUILT_IN_TM_STORE (M64
):
782 CASE_BUILT_IN_TM_STORE (M128
):
783 CASE_BUILT_IN_TM_STORE (M256
):
784 CASE_BUILT_IN_TM_LOAD (1):
785 CASE_BUILT_IN_TM_LOAD (2):
786 CASE_BUILT_IN_TM_LOAD (4):
787 CASE_BUILT_IN_TM_LOAD (8):
788 CASE_BUILT_IN_TM_LOAD (FLOAT
):
789 CASE_BUILT_IN_TM_LOAD (DOUBLE
):
790 CASE_BUILT_IN_TM_LOAD (LDOUBLE
):
791 CASE_BUILT_IN_TM_LOAD (M64
):
792 CASE_BUILT_IN_TM_LOAD (M128
):
793 CASE_BUILT_IN_TM_LOAD (M256
):
794 case BUILT_IN_TM_LOG
:
795 case BUILT_IN_TM_LOG_1
:
796 case BUILT_IN_TM_LOG_2
:
797 case BUILT_IN_TM_LOG_4
:
798 case BUILT_IN_TM_LOG_8
:
799 case BUILT_IN_TM_LOG_FLOAT
:
800 case BUILT_IN_TM_LOG_DOUBLE
:
801 case BUILT_IN_TM_LOG_LDOUBLE
:
802 case BUILT_IN_TM_LOG_M64
:
803 case BUILT_IN_TM_LOG_M128
:
804 case BUILT_IN_TM_LOG_M256
:
813 /* Detect flags (function attributes) from the function decl or type node. */
816 flags_from_decl_or_type (const_tree exp
)
822 /* The function exp may have the `malloc' attribute. */
823 if (DECL_IS_MALLOC (exp
))
826 /* The function exp may have the `returns_twice' attribute. */
827 if (DECL_IS_RETURNS_TWICE (exp
))
828 flags
|= ECF_RETURNS_TWICE
;
830 /* Process the pure and const attributes. */
831 if (TREE_READONLY (exp
))
833 if (DECL_PURE_P (exp
))
835 if (DECL_LOOPING_CONST_OR_PURE_P (exp
))
836 flags
|= ECF_LOOPING_CONST_OR_PURE
;
838 if (DECL_IS_NOVOPS (exp
))
840 if (lookup_attribute ("leaf", DECL_ATTRIBUTES (exp
)))
842 if (lookup_attribute ("cold", DECL_ATTRIBUTES (exp
)))
845 if (TREE_NOTHROW (exp
))
846 flags
|= ECF_NOTHROW
;
850 if (is_tm_builtin (exp
))
851 flags
|= ECF_TM_BUILTIN
;
852 else if ((flags
& (ECF_CONST
|ECF_NOVOPS
)) != 0
853 || lookup_attribute ("transaction_pure",
854 TYPE_ATTRIBUTES (TREE_TYPE (exp
))))
855 flags
|= ECF_TM_PURE
;
858 flags
= special_function_p (exp
, flags
);
860 else if (TYPE_P (exp
))
862 if (TYPE_READONLY (exp
))
866 && ((flags
& ECF_CONST
) != 0
867 || lookup_attribute ("transaction_pure", TYPE_ATTRIBUTES (exp
))))
868 flags
|= ECF_TM_PURE
;
873 if (TREE_THIS_VOLATILE (exp
))
875 flags
|= ECF_NORETURN
;
876 if (flags
& (ECF_CONST
|ECF_PURE
))
877 flags
|= ECF_LOOPING_CONST_OR_PURE
;
883 /* Detect flags from a CALL_EXPR. */
886 call_expr_flags (const_tree t
)
889 tree decl
= get_callee_fndecl (t
);
892 flags
= flags_from_decl_or_type (decl
);
893 else if (CALL_EXPR_FN (t
) == NULL_TREE
)
894 flags
= internal_fn_flags (CALL_EXPR_IFN (t
));
897 tree type
= TREE_TYPE (CALL_EXPR_FN (t
));
898 if (type
&& TREE_CODE (type
) == POINTER_TYPE
)
899 flags
= flags_from_decl_or_type (TREE_TYPE (type
));
902 if (CALL_EXPR_BY_DESCRIPTOR (t
))
903 flags
|= ECF_BY_DESCRIPTOR
;
909 /* Return true if TYPE should be passed by invisible reference. */
912 pass_by_reference (CUMULATIVE_ARGS
*ca
, machine_mode mode
,
913 tree type
, bool named_arg
)
917 /* If this type contains non-trivial constructors, then it is
918 forbidden for the middle-end to create any new copies. */
919 if (TREE_ADDRESSABLE (type
))
922 /* GCC post 3.4 passes *all* variable sized types by reference. */
923 if (!TYPE_SIZE (type
) || TREE_CODE (TYPE_SIZE (type
)) != INTEGER_CST
)
926 /* If a record type should be passed the same as its first (and only)
927 member, use the type and mode of that member. */
928 if (TREE_CODE (type
) == RECORD_TYPE
&& TYPE_TRANSPARENT_AGGR (type
))
930 type
= TREE_TYPE (first_field (type
));
931 mode
= TYPE_MODE (type
);
935 return targetm
.calls
.pass_by_reference (pack_cumulative_args (ca
), mode
,
939 /* Return true if TYPE, which is passed by reference, should be callee
940 copied instead of caller copied. */
943 reference_callee_copied (CUMULATIVE_ARGS
*ca
, machine_mode mode
,
944 tree type
, bool named_arg
)
946 if (type
&& TREE_ADDRESSABLE (type
))
948 return targetm
.calls
.callee_copies (pack_cumulative_args (ca
), mode
, type
,
953 /* Precompute all register parameters as described by ARGS, storing values
954 into fields within the ARGS array.
956 NUM_ACTUALS indicates the total number elements in the ARGS array.
958 Set REG_PARM_SEEN if we encounter a register parameter. */
961 precompute_register_parameters (int num_actuals
, struct arg_data
*args
,
968 for (i
= 0; i
< num_actuals
; i
++)
969 if (args
[i
].reg
!= 0 && ! args
[i
].pass_on_stack
)
973 if (args
[i
].value
== 0)
976 args
[i
].value
= expand_normal (args
[i
].tree_value
);
977 preserve_temp_slots (args
[i
].value
);
981 /* If we are to promote the function arg to a wider mode,
984 if (args
[i
].mode
!= TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)))
986 = convert_modes (args
[i
].mode
,
987 TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)),
988 args
[i
].value
, args
[i
].unsignedp
);
990 /* If the value is a non-legitimate constant, force it into a
991 pseudo now. TLS symbols sometimes need a call to resolve. */
992 if (CONSTANT_P (args
[i
].value
)
993 && !targetm
.legitimate_constant_p (args
[i
].mode
, args
[i
].value
))
994 args
[i
].value
= force_reg (args
[i
].mode
, args
[i
].value
);
996 /* If we're going to have to load the value by parts, pull the
997 parts into pseudos. The part extraction process can involve
998 non-trivial computation. */
999 if (GET_CODE (args
[i
].reg
) == PARALLEL
)
1001 tree type
= TREE_TYPE (args
[i
].tree_value
);
1002 args
[i
].parallel_value
1003 = emit_group_load_into_temps (args
[i
].reg
, args
[i
].value
,
1004 type
, int_size_in_bytes (type
));
1007 /* If the value is expensive, and we are inside an appropriately
1008 short loop, put the value into a pseudo and then put the pseudo
1011 For small register classes, also do this if this call uses
1012 register parameters. This is to avoid reload conflicts while
1013 loading the parameters registers. */
1015 else if ((! (REG_P (args
[i
].value
)
1016 || (GET_CODE (args
[i
].value
) == SUBREG
1017 && REG_P (SUBREG_REG (args
[i
].value
)))))
1018 && args
[i
].mode
!= BLKmode
1019 && (set_src_cost (args
[i
].value
, args
[i
].mode
,
1020 optimize_insn_for_speed_p ())
1021 > COSTS_N_INSNS (1))
1023 && targetm
.small_register_classes_for_mode_p (args
[i
].mode
))
1025 args
[i
].value
= copy_to_mode_reg (args
[i
].mode
, args
[i
].value
);
1029 #ifdef REG_PARM_STACK_SPACE
1031 /* The argument list is the property of the called routine and it
1032 may clobber it. If the fixed area has been used for previous
1033 parameters, we must save and restore it. */
1036 save_fixed_argument_area (int reg_parm_stack_space
, rtx argblock
, int *low_to_save
, int *high_to_save
)
1041 /* Compute the boundary of the area that needs to be saved, if any. */
1042 high
= reg_parm_stack_space
;
1043 if (ARGS_GROW_DOWNWARD
)
1046 if (high
> highest_outgoing_arg_in_use
)
1047 high
= highest_outgoing_arg_in_use
;
1049 for (low
= 0; low
< high
; low
++)
1050 if (stack_usage_map
[low
] != 0 || low
>= stack_usage_watermark
)
1053 machine_mode save_mode
;
1059 while (stack_usage_map
[--high
] == 0)
1063 *high_to_save
= high
;
1065 num_to_save
= high
- low
+ 1;
1067 /* If we don't have the required alignment, must do this
1069 scalar_int_mode imode
;
1070 if (int_mode_for_size (num_to_save
* BITS_PER_UNIT
, 1).exists (&imode
)
1071 && (low
& (MIN (GET_MODE_SIZE (imode
),
1072 BIGGEST_ALIGNMENT
/ UNITS_PER_WORD
) - 1)) == 0)
1075 save_mode
= BLKmode
;
1077 if (ARGS_GROW_DOWNWARD
)
1082 addr
= plus_constant (Pmode
, argblock
, delta
);
1083 stack_area
= gen_rtx_MEM (save_mode
, memory_address (save_mode
, addr
));
1085 set_mem_align (stack_area
, PARM_BOUNDARY
);
1086 if (save_mode
== BLKmode
)
1088 save_area
= assign_stack_temp (BLKmode
, num_to_save
);
1089 emit_block_move (validize_mem (save_area
), stack_area
,
1090 GEN_INT (num_to_save
), BLOCK_OP_CALL_PARM
);
1094 save_area
= gen_reg_rtx (save_mode
);
1095 emit_move_insn (save_area
, stack_area
);
1105 restore_fixed_argument_area (rtx save_area
, rtx argblock
, int high_to_save
, int low_to_save
)
1107 machine_mode save_mode
= GET_MODE (save_area
);
1109 rtx addr
, stack_area
;
1111 if (ARGS_GROW_DOWNWARD
)
1112 delta
= -high_to_save
;
1114 delta
= low_to_save
;
1116 addr
= plus_constant (Pmode
, argblock
, delta
);
1117 stack_area
= gen_rtx_MEM (save_mode
, memory_address (save_mode
, addr
));
1118 set_mem_align (stack_area
, PARM_BOUNDARY
);
1120 if (save_mode
!= BLKmode
)
1121 emit_move_insn (stack_area
, save_area
);
1123 emit_block_move (stack_area
, validize_mem (save_area
),
1124 GEN_INT (high_to_save
- low_to_save
+ 1),
1125 BLOCK_OP_CALL_PARM
);
1127 #endif /* REG_PARM_STACK_SPACE */
1129 /* If any elements in ARGS refer to parameters that are to be passed in
1130 registers, but not in memory, and whose alignment does not permit a
1131 direct copy into registers. Copy the values into a group of pseudos
1132 which we will later copy into the appropriate hard registers.
1134 Pseudos for each unaligned argument will be stored into the array
1135 args[argnum].aligned_regs. The caller is responsible for deallocating
1136 the aligned_regs array if it is nonzero. */
1139 store_unaligned_arguments_into_pseudos (struct arg_data
*args
, int num_actuals
)
1143 for (i
= 0; i
< num_actuals
; i
++)
1144 if (args
[i
].reg
!= 0 && ! args
[i
].pass_on_stack
1145 && GET_CODE (args
[i
].reg
) != PARALLEL
1146 && args
[i
].mode
== BLKmode
1147 && MEM_P (args
[i
].value
)
1148 && (MEM_ALIGN (args
[i
].value
)
1149 < (unsigned int) MIN (BIGGEST_ALIGNMENT
, BITS_PER_WORD
)))
1151 int bytes
= int_size_in_bytes (TREE_TYPE (args
[i
].tree_value
));
1152 int endian_correction
= 0;
1154 if (args
[i
].partial
)
1156 gcc_assert (args
[i
].partial
% UNITS_PER_WORD
== 0);
1157 args
[i
].n_aligned_regs
= args
[i
].partial
/ UNITS_PER_WORD
;
1161 args
[i
].n_aligned_regs
1162 = (bytes
+ UNITS_PER_WORD
- 1) / UNITS_PER_WORD
;
1165 args
[i
].aligned_regs
= XNEWVEC (rtx
, args
[i
].n_aligned_regs
);
1167 /* Structures smaller than a word are normally aligned to the
1168 least significant byte. On a BYTES_BIG_ENDIAN machine,
1169 this means we must skip the empty high order bytes when
1170 calculating the bit offset. */
1171 if (bytes
< UNITS_PER_WORD
1172 #ifdef BLOCK_REG_PADDING
1173 && (BLOCK_REG_PADDING (args
[i
].mode
,
1174 TREE_TYPE (args
[i
].tree_value
), 1)
1180 endian_correction
= BITS_PER_WORD
- bytes
* BITS_PER_UNIT
;
1182 for (j
= 0; j
< args
[i
].n_aligned_regs
; j
++)
1184 rtx reg
= gen_reg_rtx (word_mode
);
1185 rtx word
= operand_subword_force (args
[i
].value
, j
, BLKmode
);
1186 int bitsize
= MIN (bytes
* BITS_PER_UNIT
, BITS_PER_WORD
);
1188 args
[i
].aligned_regs
[j
] = reg
;
1189 word
= extract_bit_field (word
, bitsize
, 0, 1, NULL_RTX
,
1190 word_mode
, word_mode
, false, NULL
);
1192 /* There is no need to restrict this code to loading items
1193 in TYPE_ALIGN sized hunks. The bitfield instructions can
1194 load up entire word sized registers efficiently.
1196 ??? This may not be needed anymore.
1197 We use to emit a clobber here but that doesn't let later
1198 passes optimize the instructions we emit. By storing 0 into
1199 the register later passes know the first AND to zero out the
1200 bitfield being set in the register is unnecessary. The store
1201 of 0 will be deleted as will at least the first AND. */
1203 emit_move_insn (reg
, const0_rtx
);
1205 bytes
-= bitsize
/ BITS_PER_UNIT
;
1206 store_bit_field (reg
, bitsize
, endian_correction
, 0, 0,
1207 word_mode
, word
, false);
1212 /* The limit set by -Walloc-larger-than=. */
1213 static GTY(()) tree alloc_object_size_limit
;
1215 /* Initialize ALLOC_OBJECT_SIZE_LIMIT based on the -Walloc-size-larger-than=
1216 setting if the option is specified, or to the maximum object size if it
1217 is not. Return the initialized value. */
1220 alloc_max_size (void)
1222 if (alloc_object_size_limit
)
1223 return alloc_object_size_limit
;
1225 HOST_WIDE_INT limit
= warn_alloc_size_limit
;
1226 if (limit
== HOST_WIDE_INT_MAX
)
1227 limit
= tree_to_shwi (TYPE_MAX_VALUE (ptrdiff_type_node
));
1229 alloc_object_size_limit
= build_int_cst (size_type_node
, limit
);
1231 return alloc_object_size_limit
;
1234 /* Return true when EXP's range can be determined and set RANGE[] to it
1235 after adjusting it if necessary to make EXP a represents a valid size
1236 of object, or a valid size argument to an allocation function declared
1237 with attribute alloc_size (whose argument may be signed), or to a string
1238 manipulation function like memset. When ALLOW_ZERO is true, allow
1239 returning a range of [0, 0] for a size in an anti-range [1, N] where
1240 N > PTRDIFF_MAX. A zero range is a (nearly) invalid argument to
1241 allocation functions like malloc but it is a valid argument to
1242 functions like memset. */
1245 get_size_range (tree exp
, tree range
[2], bool allow_zero
/* = false */)
1247 if (tree_fits_uhwi_p (exp
))
1249 /* EXP is a constant. */
1250 range
[0] = range
[1] = exp
;
1254 tree exptype
= TREE_TYPE (exp
);
1255 bool integral
= INTEGRAL_TYPE_P (exptype
);
1258 enum value_range_type range_type
;
1261 range_type
= determine_value_range (exp
, &min
, &max
);
1263 range_type
= VR_VARYING
;
1265 if (range_type
== VR_VARYING
)
1269 /* Use the full range of the type of the expression when
1270 no value range information is available. */
1271 range
[0] = TYPE_MIN_VALUE (exptype
);
1272 range
[1] = TYPE_MAX_VALUE (exptype
);
1276 range
[0] = NULL_TREE
;
1277 range
[1] = NULL_TREE
;
1281 unsigned expprec
= TYPE_PRECISION (exptype
);
1283 bool signed_p
= !TYPE_UNSIGNED (exptype
);
1285 if (range_type
== VR_ANTI_RANGE
)
1289 if (wi::les_p (max
, 0))
1291 /* EXP is not in a strictly negative range. That means
1292 it must be in some (not necessarily strictly) positive
1293 range which includes zero. Since in signed to unsigned
1294 conversions negative values end up converted to large
1295 positive values, and otherwise they are not valid sizes,
1296 the resulting range is in both cases [0, TYPE_MAX]. */
1297 min
= wi::zero (expprec
);
1298 max
= wi::to_wide (TYPE_MAX_VALUE (exptype
));
1300 else if (wi::les_p (min
- 1, 0))
1302 /* EXP is not in a negative-positive range. That means EXP
1303 is either negative, or greater than max. Since negative
1304 sizes are invalid make the range [MAX + 1, TYPE_MAX]. */
1306 max
= wi::to_wide (TYPE_MAX_VALUE (exptype
));
1311 min
= wi::zero (expprec
);
1314 else if (wi::eq_p (0, min
- 1))
1316 /* EXP is unsigned and not in the range [1, MAX]. That means
1317 it's either zero or greater than MAX. Even though 0 would
1318 normally be detected by -Walloc-zero, unless ALLOW_ZERO
1319 is true, set the range to [MAX, TYPE_MAX] so that when MAX
1320 is greater than the limit the whole range is diagnosed. */
1322 min
= max
= wi::zero (expprec
);
1326 max
= wi::to_wide (TYPE_MAX_VALUE (exptype
));
1332 min
= wi::zero (expprec
);
1336 range
[0] = wide_int_to_tree (exptype
, min
);
1337 range
[1] = wide_int_to_tree (exptype
, max
);
1342 /* Diagnose a call EXP to function FN decorated with attribute alloc_size
1343 whose argument numbers given by IDX with values given by ARGS exceed
1344 the maximum object size or cause an unsigned oveflow (wrapping) when
1345 multiplied. When ARGS[0] is null the function does nothing. ARGS[1]
1346 may be null for functions like malloc, and non-null for those like
1347 calloc that are decorated with a two-argument attribute alloc_size. */
1350 maybe_warn_alloc_args_overflow (tree fn
, tree exp
, tree args
[2], int idx
[2])
1352 /* The range each of the (up to) two arguments is known to be in. */
1353 tree argrange
[2][2] = { { NULL_TREE
, NULL_TREE
}, { NULL_TREE
, NULL_TREE
} };
1355 /* Maximum object size set by -Walloc-size-larger-than= or SIZE_MAX / 2. */
1356 tree maxobjsize
= alloc_max_size ();
1358 location_t loc
= EXPR_LOCATION (exp
);
1360 bool warned
= false;
1362 /* Validate each argument individually. */
1363 for (unsigned i
= 0; i
!= 2 && args
[i
]; ++i
)
1365 if (TREE_CODE (args
[i
]) == INTEGER_CST
)
1367 argrange
[i
][0] = args
[i
];
1368 argrange
[i
][1] = args
[i
];
1370 if (tree_int_cst_lt (args
[i
], integer_zero_node
))
1372 warned
= warning_at (loc
, OPT_Walloc_size_larger_than_
,
1373 "%Kargument %i value %qE is negative",
1374 exp
, idx
[i
] + 1, args
[i
]);
1376 else if (integer_zerop (args
[i
]))
1378 /* Avoid issuing -Walloc-zero for allocation functions other
1379 than __builtin_alloca that are declared with attribute
1380 returns_nonnull because there's no portability risk. This
1381 avoids warning for such calls to libiberty's xmalloc and
1383 Also avoid issuing the warning for calls to function named
1385 if ((DECL_FUNCTION_CODE (fn
) == BUILT_IN_ALLOCA
1386 && IDENTIFIER_LENGTH (DECL_NAME (fn
)) != 6)
1387 || (DECL_FUNCTION_CODE (fn
) != BUILT_IN_ALLOCA
1388 && !lookup_attribute ("returns_nonnull",
1389 TYPE_ATTRIBUTES (TREE_TYPE (fn
)))))
1390 warned
= warning_at (loc
, OPT_Walloc_zero
,
1391 "%Kargument %i value is zero",
1394 else if (tree_int_cst_lt (maxobjsize
, args
[i
]))
1396 /* G++ emits calls to ::operator new[](SIZE_MAX) in C++98
1397 mode and with -fno-exceptions as a way to indicate array
1398 size overflow. There's no good way to detect C++98 here
1399 so avoid diagnosing these calls for all C++ modes. */
1403 && DECL_IS_OPERATOR_NEW (fn
)
1404 && integer_all_onesp (args
[i
]))
1407 warned
= warning_at (loc
, OPT_Walloc_size_larger_than_
,
1408 "%Kargument %i value %qE exceeds "
1409 "maximum object size %E",
1410 exp
, idx
[i
] + 1, args
[i
], maxobjsize
);
1413 else if (TREE_CODE (args
[i
]) == SSA_NAME
1414 && get_size_range (args
[i
], argrange
[i
]))
1416 /* Verify that the argument's range is not negative (including
1417 upper bound of zero). */
1418 if (tree_int_cst_lt (argrange
[i
][0], integer_zero_node
)
1419 && tree_int_cst_le (argrange
[i
][1], integer_zero_node
))
1421 warned
= warning_at (loc
, OPT_Walloc_size_larger_than_
,
1422 "%Kargument %i range [%E, %E] is negative",
1424 argrange
[i
][0], argrange
[i
][1]);
1426 else if (tree_int_cst_lt (maxobjsize
, argrange
[i
][0]))
1428 warned
= warning_at (loc
, OPT_Walloc_size_larger_than_
,
1429 "%Kargument %i range [%E, %E] exceeds "
1430 "maximum object size %E",
1432 argrange
[i
][0], argrange
[i
][1],
1441 /* For a two-argument alloc_size, validate the product of the two
1442 arguments if both of their values or ranges are known. */
1443 if (!warned
&& tree_fits_uhwi_p (argrange
[0][0])
1444 && argrange
[1][0] && tree_fits_uhwi_p (argrange
[1][0])
1445 && !integer_onep (argrange
[0][0])
1446 && !integer_onep (argrange
[1][0]))
1448 /* Check for overflow in the product of a function decorated with
1449 attribute alloc_size (X, Y). */
1450 unsigned szprec
= TYPE_PRECISION (size_type_node
);
1451 wide_int x
= wi::to_wide (argrange
[0][0], szprec
);
1452 wide_int y
= wi::to_wide (argrange
[1][0], szprec
);
1454 wi::overflow_type vflow
;
1455 wide_int prod
= wi::umul (x
, y
, &vflow
);
1458 warned
= warning_at (loc
, OPT_Walloc_size_larger_than_
,
1459 "%Kproduct %<%E * %E%> of arguments %i and %i "
1460 "exceeds %<SIZE_MAX%>",
1461 exp
, argrange
[0][0], argrange
[1][0],
1462 idx
[0] + 1, idx
[1] + 1);
1463 else if (wi::ltu_p (wi::to_wide (maxobjsize
, szprec
), prod
))
1464 warned
= warning_at (loc
, OPT_Walloc_size_larger_than_
,
1465 "%Kproduct %<%E * %E%> of arguments %i and %i "
1466 "exceeds maximum object size %E",
1467 exp
, argrange
[0][0], argrange
[1][0],
1468 idx
[0] + 1, idx
[1] + 1,
1473 /* Print the full range of each of the two arguments to make
1474 it clear when it is, in fact, in a range and not constant. */
1475 if (argrange
[0][0] != argrange
[0][1])
1476 inform (loc
, "argument %i in the range [%E, %E]",
1477 idx
[0] + 1, argrange
[0][0], argrange
[0][1]);
1478 if (argrange
[1][0] != argrange
[1][1])
1479 inform (loc
, "argument %i in the range [%E, %E]",
1480 idx
[1] + 1, argrange
[1][0], argrange
[1][1]);
1486 location_t fnloc
= DECL_SOURCE_LOCATION (fn
);
1488 if (DECL_IS_BUILTIN (fn
))
1490 "in a call to built-in allocation function %qD", fn
);
1493 "in a call to allocation function %qD declared here", fn
);
1497 /* If EXPR refers to a character array or pointer declared attribute
1498 nonstring return a decl for that array or pointer and set *REF to
1499 the referenced enclosing object or pointer. Otherwise returns
1503 get_attr_nonstring_decl (tree expr
, tree
*ref
)
1506 if (TREE_CODE (decl
) == SSA_NAME
)
1508 gimple
*def
= SSA_NAME_DEF_STMT (decl
);
1510 if (is_gimple_assign (def
))
1512 tree_code code
= gimple_assign_rhs_code (def
);
1513 if (code
== ADDR_EXPR
1514 || code
== COMPONENT_REF
1515 || code
== VAR_DECL
)
1516 decl
= gimple_assign_rhs1 (def
);
1518 else if (tree var
= SSA_NAME_VAR (decl
))
1522 if (TREE_CODE (decl
) == ADDR_EXPR
)
1523 decl
= TREE_OPERAND (decl
, 0);
1528 if (TREE_CODE (decl
) == ARRAY_REF
)
1529 decl
= TREE_OPERAND (decl
, 0);
1530 else if (TREE_CODE (decl
) == COMPONENT_REF
)
1531 decl
= TREE_OPERAND (decl
, 1);
1532 else if (TREE_CODE (decl
) == MEM_REF
)
1533 return get_attr_nonstring_decl (TREE_OPERAND (decl
, 0), ref
);
1536 && lookup_attribute ("nonstring", DECL_ATTRIBUTES (decl
)))
1542 /* Warn about passing a non-string array/pointer to a function that
1543 expects a nul-terminated string argument. */
1546 maybe_warn_nonstring_arg (tree fndecl
, tree exp
)
1548 if (!fndecl
|| !fndecl_built_in_p (fndecl
, BUILT_IN_NORMAL
))
1551 if (TREE_NO_WARNING (exp
) || !warn_stringop_overflow
)
1554 unsigned nargs
= call_expr_nargs (exp
);
1556 /* The bound argument to a bounded string function like strncpy. */
1557 tree bound
= NULL_TREE
;
1559 /* The range of lengths of a string argument to one of the comparison
1560 functions. If the length is less than the bound it is used instead. */
1561 tree lenrng
[2] = { NULL_TREE
, NULL_TREE
};
1563 /* It's safe to call "bounded" string functions with a non-string
1564 argument since the functions provide an explicit bound for this
1565 purpose. The exception is strncat where the bound may refer to
1566 either the destination or the source. */
1567 int fncode
= DECL_FUNCTION_CODE (fndecl
);
1570 case BUILT_IN_STRCMP
:
1571 case BUILT_IN_STRNCMP
:
1572 case BUILT_IN_STRNCASECMP
:
1574 /* For these, if one argument refers to one or more of a set
1575 of string constants or arrays of known size, determine
1576 the range of their known or possible lengths and use it
1577 conservatively as the bound for the unbounded function,
1578 and to adjust the range of the bound of the bounded ones. */
1579 for (unsigned argno
= 0;
1580 argno
< MIN (nargs
, 2)
1581 && !(lenrng
[1] && TREE_CODE (lenrng
[1]) == INTEGER_CST
); argno
++)
1583 tree arg
= CALL_EXPR_ARG (exp
, argno
);
1584 if (!get_attr_nonstring_decl (arg
))
1585 get_range_strlen (arg
, lenrng
);
1590 case BUILT_IN_STRNCAT
:
1591 case BUILT_IN_STPNCPY
:
1592 case BUILT_IN_STRNCPY
:
1594 bound
= CALL_EXPR_ARG (exp
, 2);
1597 case BUILT_IN_STRNDUP
:
1599 bound
= CALL_EXPR_ARG (exp
, 1);
1602 case BUILT_IN_STRNLEN
:
1604 tree arg
= CALL_EXPR_ARG (exp
, 0);
1605 if (!get_attr_nonstring_decl (arg
))
1606 get_range_strlen (arg
, lenrng
);
1609 bound
= CALL_EXPR_ARG (exp
, 1);
1617 /* Determine the range of the bound argument (if specified). */
1618 tree bndrng
[2] = { NULL_TREE
, NULL_TREE
};
1622 get_size_range (bound
, bndrng
);
1625 location_t loc
= EXPR_LOCATION (exp
);
1629 /* Diagnose excessive bound prior the adjustment below and
1630 regardless of attribute nonstring. */
1631 tree maxobjsize
= max_object_size ();
1632 if (tree_int_cst_lt (maxobjsize
, bndrng
[0]))
1634 if (tree_int_cst_equal (bndrng
[0], bndrng
[1]))
1635 warning_at (loc
, OPT_Wstringop_overflow_
,
1636 "%K%qD specified bound %E "
1637 "exceeds maximum object size %E",
1638 exp
, fndecl
, bndrng
[0], maxobjsize
);
1640 warning_at (loc
, OPT_Wstringop_overflow_
,
1641 "%K%qD specified bound [%E, %E] "
1642 "exceeds maximum object size %E",
1643 exp
, fndecl
, bndrng
[0], bndrng
[1], maxobjsize
);
1648 if (lenrng
[1] && TREE_CODE (lenrng
[1]) == INTEGER_CST
)
1650 /* Add one for the nul. */
1651 lenrng
[1] = const_binop (PLUS_EXPR
, TREE_TYPE (lenrng
[1]),
1652 lenrng
[1], size_one_node
);
1656 /* Conservatively use the upper bound of the lengths for
1657 both the lower and the upper bound of the operation. */
1658 bndrng
[0] = lenrng
[1];
1659 bndrng
[1] = lenrng
[1];
1660 bound
= void_type_node
;
1664 /* Replace the bound on the operation with the upper bound
1665 of the length of the string if the latter is smaller. */
1666 if (tree_int_cst_lt (lenrng
[1], bndrng
[0]))
1667 bndrng
[0] = lenrng
[1];
1668 else if (tree_int_cst_lt (lenrng
[1], bndrng
[1]))
1669 bndrng
[1] = lenrng
[1];
1673 /* Iterate over the built-in function's formal arguments and check
1674 each const char* against the actual argument. If the actual
1675 argument is declared attribute non-string issue a warning unless
1676 the argument's maximum length is bounded. */
1677 function_args_iterator it
;
1678 function_args_iter_init (&it
, TREE_TYPE (fndecl
));
1680 for (unsigned argno
= 0; ; ++argno
, function_args_iter_next (&it
))
1682 /* Avoid iterating past the declared argument in a call
1683 to function declared without a prototype. */
1687 tree argtype
= function_args_iter_cond (&it
);
1691 if (TREE_CODE (argtype
) != POINTER_TYPE
)
1694 argtype
= TREE_TYPE (argtype
);
1696 if (TREE_CODE (argtype
) != INTEGER_TYPE
1697 || !TYPE_READONLY (argtype
))
1700 argtype
= TYPE_MAIN_VARIANT (argtype
);
1701 if (argtype
!= char_type_node
)
1704 tree callarg
= CALL_EXPR_ARG (exp
, argno
);
1705 if (TREE_CODE (callarg
) == ADDR_EXPR
)
1706 callarg
= TREE_OPERAND (callarg
, 0);
1708 /* See if the destination is declared with attribute "nonstring". */
1709 tree decl
= get_attr_nonstring_decl (callarg
);
1713 /* The maximum number of array elements accessed. */
1714 offset_int wibnd
= 0;
1716 if (argno
&& fncode
== BUILT_IN_STRNCAT
)
1718 /* See if the bound in strncat is derived from the length
1719 of the strlen of the destination (as it's expected to be).
1720 If so, reset BOUND and FNCODE to trigger a warning. */
1721 tree dstarg
= CALL_EXPR_ARG (exp
, 0);
1722 if (is_strlen_related_p (dstarg
, bound
))
1724 /* The bound applies to the destination, not to the source,
1725 so reset these to trigger a warning without mentioning
1731 /* Use the upper bound of the range for strncat. */
1732 wibnd
= wi::to_offset (bndrng
[1]);
1735 /* Use the lower bound of the range for functions other than
1737 wibnd
= wi::to_offset (bndrng
[0]);
1739 /* Determine the size of the argument array if it is one. */
1740 offset_int asize
= wibnd
;
1741 bool known_size
= false;
1742 tree type
= TREE_TYPE (decl
);
1744 /* Determine the array size. For arrays of unknown bound and
1745 pointers reset BOUND to trigger the appropriate warning. */
1746 if (TREE_CODE (type
) == ARRAY_TYPE
)
1748 if (tree arrbnd
= TYPE_DOMAIN (type
))
1750 if ((arrbnd
= TYPE_MAX_VALUE (arrbnd
)))
1752 asize
= wi::to_offset (arrbnd
) + 1;
1756 else if (bound
== void_type_node
)
1759 else if (bound
== void_type_node
)
1762 /* In a call to strncat with a bound in a range whose lower but
1763 not upper bound is less than the array size, reset ASIZE to
1764 be the same as the bound and the other variable to trigger
1765 the apprpriate warning below. */
1766 if (fncode
== BUILT_IN_STRNCAT
1767 && bndrng
[0] != bndrng
[1]
1768 && wi::ltu_p (wi::to_offset (bndrng
[0]), asize
)
1770 || wi::ltu_p (asize
, wibnd
)))
1777 bool warned
= false;
1779 auto_diagnostic_group d
;
1780 if (wi::ltu_p (asize
, wibnd
))
1782 if (bndrng
[0] == bndrng
[1])
1783 warned
= warning_at (loc
, OPT_Wstringop_overflow_
,
1784 "%qD argument %i declared attribute "
1785 "%<nonstring%> is smaller than the specified "
1787 fndecl
, argno
+ 1, wibnd
.to_uhwi ());
1788 else if (wi::ltu_p (asize
, wi::to_offset (bndrng
[0])))
1789 warned
= warning_at (loc
, OPT_Wstringop_overflow_
,
1790 "%qD argument %i declared attribute "
1791 "%<nonstring%> is smaller than "
1792 "the specified bound [%E, %E]",
1793 fndecl
, argno
+ 1, bndrng
[0], bndrng
[1]);
1795 warned
= warning_at (loc
, OPT_Wstringop_overflow_
,
1796 "%qD argument %i declared attribute "
1797 "%<nonstring%> may be smaller than "
1798 "the specified bound [%E, %E]",
1799 fndecl
, argno
+ 1, bndrng
[0], bndrng
[1]);
1801 else if (fncode
== BUILT_IN_STRNCAT
)
1802 ; /* Avoid warning for calls to strncat() when the bound
1803 is equal to the size of the non-string argument. */
1805 warned
= warning_at (loc
, OPT_Wstringop_overflow_
,
1806 "%qD argument %i declared attribute %<nonstring%>",
1810 inform (DECL_SOURCE_LOCATION (decl
),
1811 "argument %qD declared here", decl
);
1815 /* Issue an error if CALL_EXPR was flagged as requiring
1816 tall-call optimization. */
1819 maybe_complain_about_tail_call (tree call_expr
, const char *reason
)
1821 gcc_assert (TREE_CODE (call_expr
) == CALL_EXPR
);
1822 if (!CALL_EXPR_MUST_TAIL_CALL (call_expr
))
1825 error_at (EXPR_LOCATION (call_expr
), "cannot tail-call: %s", reason
);
1828 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
1831 NUM_ACTUALS is the total number of parameters.
1833 N_NAMED_ARGS is the total number of named arguments.
1835 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
1838 FNDECL is the tree code for the target of this call (if known)
1840 ARGS_SO_FAR holds state needed by the target to know where to place
1843 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1844 for arguments which are passed in registers.
1846 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1847 and may be modified by this routine.
1849 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1850 flags which may be modified by this routine.
1852 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
1853 that requires allocation of stack space.
1855 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
1856 the thunked-to function. */
1859 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED
,
1860 struct arg_data
*args
,
1861 struct args_size
*args_size
,
1862 int n_named_args ATTRIBUTE_UNUSED
,
1863 tree exp
, tree struct_value_addr_value
,
1864 tree fndecl
, tree fntype
,
1865 cumulative_args_t args_so_far
,
1866 int reg_parm_stack_space
,
1867 rtx
*old_stack_level
,
1868 poly_int64_pod
*old_pending_adj
,
1869 int *must_preallocate
, int *ecf_flags
,
1870 bool *may_tailcall
, bool call_from_thunk_p
)
1872 CUMULATIVE_ARGS
*args_so_far_pnt
= get_cumulative_args (args_so_far
);
1873 location_t loc
= EXPR_LOCATION (exp
);
1875 /* Count arg position in order args appear. */
1880 args_size
->constant
= 0;
1883 bitmap_obstack_initialize (NULL
);
1885 /* In this loop, we consider args in the order they are written.
1886 We fill up ARGS from the back. */
1888 i
= num_actuals
- 1;
1891 call_expr_arg_iterator iter
;
1893 bitmap slots
= NULL
;
1895 if (struct_value_addr_value
)
1897 args
[j
].tree_value
= struct_value_addr_value
;
1901 FOR_EACH_CALL_EXPR_ARG (arg
, iter
, exp
)
1903 tree argtype
= TREE_TYPE (arg
);
1905 if (targetm
.calls
.split_complex_arg
1907 && TREE_CODE (argtype
) == COMPLEX_TYPE
1908 && targetm
.calls
.split_complex_arg (argtype
))
1910 tree subtype
= TREE_TYPE (argtype
);
1911 args
[j
].tree_value
= build1 (REALPART_EXPR
, subtype
, arg
);
1913 args
[j
].tree_value
= build1 (IMAGPART_EXPR
, subtype
, arg
);
1916 args
[j
].tree_value
= arg
;
1922 BITMAP_FREE (slots
);
1925 bitmap_obstack_release (NULL
);
1927 /* Extract attribute alloc_size and if set, store the indices of
1928 the corresponding arguments in ALLOC_IDX, and then the actual
1929 argument(s) at those indices in ALLOC_ARGS. */
1930 int alloc_idx
[2] = { -1, -1 };
1932 = (fndecl
? lookup_attribute ("alloc_size",
1933 TYPE_ATTRIBUTES (TREE_TYPE (fndecl
)))
1936 tree args
= TREE_VALUE (alloc_size
);
1937 alloc_idx
[0] = TREE_INT_CST_LOW (TREE_VALUE (args
)) - 1;
1938 if (TREE_CHAIN (args
))
1939 alloc_idx
[1] = TREE_INT_CST_LOW (TREE_VALUE (TREE_CHAIN (args
))) - 1;
1942 /* Array for up to the two attribute alloc_size arguments. */
1943 tree alloc_args
[] = { NULL_TREE
, NULL_TREE
};
1945 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1946 for (argpos
= 0; argpos
< num_actuals
; i
--, argpos
++)
1948 tree type
= TREE_TYPE (args
[i
].tree_value
);
1952 /* Replace erroneous argument with constant zero. */
1953 if (type
== error_mark_node
|| !COMPLETE_TYPE_P (type
))
1954 args
[i
].tree_value
= integer_zero_node
, type
= integer_type_node
;
1956 /* If TYPE is a transparent union or record, pass things the way
1957 we would pass the first field of the union or record. We have
1958 already verified that the modes are the same. */
1959 if ((TREE_CODE (type
) == UNION_TYPE
|| TREE_CODE (type
) == RECORD_TYPE
)
1960 && TYPE_TRANSPARENT_AGGR (type
))
1961 type
= TREE_TYPE (first_field (type
));
1963 /* Decide where to pass this arg.
1965 args[i].reg is nonzero if all or part is passed in registers.
1967 args[i].partial is nonzero if part but not all is passed in registers,
1968 and the exact value says how many bytes are passed in registers.
1970 args[i].pass_on_stack is nonzero if the argument must at least be
1971 computed on the stack. It may then be loaded back into registers
1972 if args[i].reg is nonzero.
1974 These decisions are driven by the FUNCTION_... macros and must agree
1975 with those made by function.c. */
1977 /* See if this argument should be passed by invisible reference. */
1978 if (pass_by_reference (args_so_far_pnt
, TYPE_MODE (type
),
1979 type
, argpos
< n_named_args
))
1982 tree base
= NULL_TREE
;
1985 = reference_callee_copied (args_so_far_pnt
, TYPE_MODE (type
),
1986 type
, argpos
< n_named_args
);
1988 /* If we're compiling a thunk, pass through invisible references
1989 instead of making a copy. */
1990 if (call_from_thunk_p
1992 && !TREE_ADDRESSABLE (type
)
1993 && (base
= get_base_address (args
[i
].tree_value
))
1994 && TREE_CODE (base
) != SSA_NAME
1995 && (!DECL_P (base
) || MEM_P (DECL_RTL (base
)))))
1997 /* We may have turned the parameter value into an SSA name.
1998 Go back to the original parameter so we can take the
2000 if (TREE_CODE (args
[i
].tree_value
) == SSA_NAME
)
2002 gcc_assert (SSA_NAME_IS_DEFAULT_DEF (args
[i
].tree_value
));
2003 args
[i
].tree_value
= SSA_NAME_VAR (args
[i
].tree_value
);
2004 gcc_assert (TREE_CODE (args
[i
].tree_value
) == PARM_DECL
);
2006 /* Argument setup code may have copied the value to register. We
2007 revert that optimization now because the tail call code must
2008 use the original location. */
2009 if (TREE_CODE (args
[i
].tree_value
) == PARM_DECL
2010 && !MEM_P (DECL_RTL (args
[i
].tree_value
))
2011 && DECL_INCOMING_RTL (args
[i
].tree_value
)
2012 && MEM_P (DECL_INCOMING_RTL (args
[i
].tree_value
)))
2013 set_decl_rtl (args
[i
].tree_value
,
2014 DECL_INCOMING_RTL (args
[i
].tree_value
));
2016 mark_addressable (args
[i
].tree_value
);
2018 /* We can't use sibcalls if a callee-copied argument is
2019 stored in the current function's frame. */
2020 if (!call_from_thunk_p
&& DECL_P (base
) && !TREE_STATIC (base
))
2022 *may_tailcall
= false;
2023 maybe_complain_about_tail_call (exp
,
2024 "a callee-copied argument is"
2025 " stored in the current"
2026 " function's frame");
2029 args
[i
].tree_value
= build_fold_addr_expr_loc (loc
,
2030 args
[i
].tree_value
);
2031 type
= TREE_TYPE (args
[i
].tree_value
);
2033 if (*ecf_flags
& ECF_CONST
)
2034 *ecf_flags
&= ~(ECF_CONST
| ECF_LOOPING_CONST_OR_PURE
);
2038 /* We make a copy of the object and pass the address to the
2039 function being called. */
2042 if (!COMPLETE_TYPE_P (type
)
2043 || TREE_CODE (TYPE_SIZE_UNIT (type
)) != INTEGER_CST
2044 || (flag_stack_check
== GENERIC_STACK_CHECK
2045 && compare_tree_int (TYPE_SIZE_UNIT (type
),
2046 STACK_CHECK_MAX_VAR_SIZE
) > 0))
2048 /* This is a variable-sized object. Make space on the stack
2050 rtx size_rtx
= expr_size (args
[i
].tree_value
);
2052 if (*old_stack_level
== 0)
2054 emit_stack_save (SAVE_BLOCK
, old_stack_level
);
2055 *old_pending_adj
= pending_stack_adjust
;
2056 pending_stack_adjust
= 0;
2059 /* We can pass TRUE as the 4th argument because we just
2060 saved the stack pointer and will restore it right after
2062 copy
= allocate_dynamic_stack_space (size_rtx
,
2065 max_int_size_in_bytes
2068 copy
= gen_rtx_MEM (BLKmode
, copy
);
2069 set_mem_attributes (copy
, type
, 1);
2072 copy
= assign_temp (type
, 1, 0);
2074 store_expr (args
[i
].tree_value
, copy
, 0, false, false);
2076 /* Just change the const function to pure and then let
2077 the next test clear the pure based on
2079 if (*ecf_flags
& ECF_CONST
)
2081 *ecf_flags
&= ~ECF_CONST
;
2082 *ecf_flags
|= ECF_PURE
;
2085 if (!callee_copies
&& *ecf_flags
& ECF_PURE
)
2086 *ecf_flags
&= ~(ECF_PURE
| ECF_LOOPING_CONST_OR_PURE
);
2089 = build_fold_addr_expr_loc (loc
, make_tree (type
, copy
));
2090 type
= TREE_TYPE (args
[i
].tree_value
);
2091 *may_tailcall
= false;
2092 maybe_complain_about_tail_call (exp
,
2093 "argument must be passed"
2098 unsignedp
= TYPE_UNSIGNED (type
);
2099 mode
= promote_function_mode (type
, TYPE_MODE (type
), &unsignedp
,
2100 fndecl
? TREE_TYPE (fndecl
) : fntype
, 0);
2102 args
[i
].unsignedp
= unsignedp
;
2103 args
[i
].mode
= mode
;
2105 targetm
.calls
.warn_parameter_passing_abi (args_so_far
, type
);
2107 args
[i
].reg
= targetm
.calls
.function_arg (args_so_far
, mode
, type
,
2108 argpos
< n_named_args
);
2110 if (args
[i
].reg
&& CONST_INT_P (args
[i
].reg
))
2112 args
[i
].special_slot
= args
[i
].reg
;
2116 /* If this is a sibling call and the machine has register windows, the
2117 register window has to be unwinded before calling the routine, so
2118 arguments have to go into the incoming registers. */
2119 if (targetm
.calls
.function_incoming_arg
!= targetm
.calls
.function_arg
)
2120 args
[i
].tail_call_reg
2121 = targetm
.calls
.function_incoming_arg (args_so_far
, mode
, type
,
2122 argpos
< n_named_args
);
2124 args
[i
].tail_call_reg
= args
[i
].reg
;
2128 = targetm
.calls
.arg_partial_bytes (args_so_far
, mode
, type
,
2129 argpos
< n_named_args
);
2131 args
[i
].pass_on_stack
= targetm
.calls
.must_pass_in_stack (mode
, type
);
2133 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
2134 it means that we are to pass this arg in the register(s) designated
2135 by the PARALLEL, but also to pass it in the stack. */
2136 if (args
[i
].reg
&& GET_CODE (args
[i
].reg
) == PARALLEL
2137 && XEXP (XVECEXP (args
[i
].reg
, 0, 0), 0) == 0)
2138 args
[i
].pass_on_stack
= 1;
2140 /* If this is an addressable type, we must preallocate the stack
2141 since we must evaluate the object into its final location.
2143 If this is to be passed in both registers and the stack, it is simpler
2145 if (TREE_ADDRESSABLE (type
)
2146 || (args
[i
].pass_on_stack
&& args
[i
].reg
!= 0))
2147 *must_preallocate
= 1;
2149 /* Compute the stack-size of this argument. */
2150 if (args
[i
].reg
== 0 || args
[i
].partial
!= 0
2151 || reg_parm_stack_space
> 0
2152 || args
[i
].pass_on_stack
)
2153 locate_and_pad_parm (mode
, type
,
2154 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2159 reg_parm_stack_space
,
2160 args
[i
].pass_on_stack
? 0 : args
[i
].partial
,
2161 fndecl
, args_size
, &args
[i
].locate
);
2162 #ifdef BLOCK_REG_PADDING
2164 /* The argument is passed entirely in registers. See at which
2165 end it should be padded. */
2166 args
[i
].locate
.where_pad
=
2167 BLOCK_REG_PADDING (mode
, type
,
2168 int_size_in_bytes (type
) <= UNITS_PER_WORD
);
2171 /* Update ARGS_SIZE, the total stack space for args so far. */
2173 args_size
->constant
+= args
[i
].locate
.size
.constant
;
2174 if (args
[i
].locate
.size
.var
)
2175 ADD_PARM_SIZE (*args_size
, args
[i
].locate
.size
.var
);
2177 /* Increment ARGS_SO_FAR, which has info about which arg-registers
2178 have been used, etc. */
2180 targetm
.calls
.function_arg_advance (args_so_far
, TYPE_MODE (type
),
2181 type
, argpos
< n_named_args
);
2183 /* Store argument values for functions decorated with attribute
2185 if (argpos
== alloc_idx
[0])
2186 alloc_args
[0] = args
[i
].tree_value
;
2187 else if (argpos
== alloc_idx
[1])
2188 alloc_args
[1] = args
[i
].tree_value
;
2193 /* Check the arguments of functions decorated with attribute
2195 maybe_warn_alloc_args_overflow (fndecl
, exp
, alloc_args
, alloc_idx
);
2198 /* Detect passing non-string arguments to functions expecting
2199 nul-terminated strings. */
2200 maybe_warn_nonstring_arg (fndecl
, exp
);
2203 /* Update ARGS_SIZE to contain the total size for the argument block.
2204 Return the original constant component of the argument block's size.
2206 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
2207 for arguments passed in registers. */
2210 compute_argument_block_size (int reg_parm_stack_space
,
2211 struct args_size
*args_size
,
2212 tree fndecl ATTRIBUTE_UNUSED
,
2213 tree fntype ATTRIBUTE_UNUSED
,
2214 int preferred_stack_boundary ATTRIBUTE_UNUSED
)
2216 poly_int64 unadjusted_args_size
= args_size
->constant
;
2218 /* For accumulate outgoing args mode we don't need to align, since the frame
2219 will be already aligned. Align to STACK_BOUNDARY in order to prevent
2220 backends from generating misaligned frame sizes. */
2221 if (ACCUMULATE_OUTGOING_ARGS
&& preferred_stack_boundary
> STACK_BOUNDARY
)
2222 preferred_stack_boundary
= STACK_BOUNDARY
;
2224 /* Compute the actual size of the argument block required. The variable
2225 and constant sizes must be combined, the size may have to be rounded,
2226 and there may be a minimum required size. */
2230 args_size
->var
= ARGS_SIZE_TREE (*args_size
);
2231 args_size
->constant
= 0;
2233 preferred_stack_boundary
/= BITS_PER_UNIT
;
2234 if (preferred_stack_boundary
> 1)
2236 /* We don't handle this case yet. To handle it correctly we have
2237 to add the delta, round and subtract the delta.
2238 Currently no machine description requires this support. */
2239 gcc_assert (multiple_p (stack_pointer_delta
,
2240 preferred_stack_boundary
));
2241 args_size
->var
= round_up (args_size
->var
, preferred_stack_boundary
);
2244 if (reg_parm_stack_space
> 0)
2247 = size_binop (MAX_EXPR
, args_size
->var
,
2248 ssize_int (reg_parm_stack_space
));
2250 /* The area corresponding to register parameters is not to count in
2251 the size of the block we need. So make the adjustment. */
2252 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl
? fntype
: TREE_TYPE (fndecl
))))
2254 = size_binop (MINUS_EXPR
, args_size
->var
,
2255 ssize_int (reg_parm_stack_space
));
2260 preferred_stack_boundary
/= BITS_PER_UNIT
;
2261 if (preferred_stack_boundary
< 1)
2262 preferred_stack_boundary
= 1;
2263 args_size
->constant
= (aligned_upper_bound (args_size
->constant
2264 + stack_pointer_delta
,
2265 preferred_stack_boundary
)
2266 - stack_pointer_delta
);
2268 args_size
->constant
= upper_bound (args_size
->constant
,
2269 reg_parm_stack_space
);
2271 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl
? fntype
: TREE_TYPE (fndecl
))))
2272 args_size
->constant
-= reg_parm_stack_space
;
2274 return unadjusted_args_size
;
2277 /* Precompute parameters as needed for a function call.
2279 FLAGS is mask of ECF_* constants.
2281 NUM_ACTUALS is the number of arguments.
2283 ARGS is an array containing information for each argument; this
2284 routine fills in the INITIAL_VALUE and VALUE fields for each
2285 precomputed argument. */
2288 precompute_arguments (int num_actuals
, struct arg_data
*args
)
2292 /* If this is a libcall, then precompute all arguments so that we do not
2293 get extraneous instructions emitted as part of the libcall sequence. */
2295 /* If we preallocated the stack space, and some arguments must be passed
2296 on the stack, then we must precompute any parameter which contains a
2297 function call which will store arguments on the stack.
2298 Otherwise, evaluating the parameter may clobber previous parameters
2299 which have already been stored into the stack. (we have code to avoid
2300 such case by saving the outgoing stack arguments, but it results in
2302 if (!ACCUMULATE_OUTGOING_ARGS
)
2305 for (i
= 0; i
< num_actuals
; i
++)
2310 if (TREE_CODE (args
[i
].tree_value
) != CALL_EXPR
)
2313 /* If this is an addressable type, we cannot pre-evaluate it. */
2314 type
= TREE_TYPE (args
[i
].tree_value
);
2315 gcc_assert (!TREE_ADDRESSABLE (type
));
2317 args
[i
].initial_value
= args
[i
].value
2318 = expand_normal (args
[i
].tree_value
);
2320 mode
= TYPE_MODE (type
);
2321 if (mode
!= args
[i
].mode
)
2323 int unsignedp
= args
[i
].unsignedp
;
2325 = convert_modes (args
[i
].mode
, mode
,
2326 args
[i
].value
, args
[i
].unsignedp
);
2328 /* CSE will replace this only if it contains args[i].value
2329 pseudo, so convert it down to the declared mode using
2331 if (REG_P (args
[i
].value
)
2332 && GET_MODE_CLASS (args
[i
].mode
) == MODE_INT
2333 && promote_mode (type
, mode
, &unsignedp
) != args
[i
].mode
)
2335 args
[i
].initial_value
2336 = gen_lowpart_SUBREG (mode
, args
[i
].value
);
2337 SUBREG_PROMOTED_VAR_P (args
[i
].initial_value
) = 1;
2338 SUBREG_PROMOTED_SET (args
[i
].initial_value
, args
[i
].unsignedp
);
2344 /* Given the current state of MUST_PREALLOCATE and information about
2345 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
2346 compute and return the final value for MUST_PREALLOCATE. */
2349 finalize_must_preallocate (int must_preallocate
, int num_actuals
,
2350 struct arg_data
*args
, struct args_size
*args_size
)
2352 /* See if we have or want to preallocate stack space.
2354 If we would have to push a partially-in-regs parm
2355 before other stack parms, preallocate stack space instead.
2357 If the size of some parm is not a multiple of the required stack
2358 alignment, we must preallocate.
2360 If the total size of arguments that would otherwise create a copy in
2361 a temporary (such as a CALL) is more than half the total argument list
2362 size, preallocation is faster.
2364 Another reason to preallocate is if we have a machine (like the m88k)
2365 where stack alignment is required to be maintained between every
2366 pair of insns, not just when the call is made. However, we assume here
2367 that such machines either do not have push insns (and hence preallocation
2368 would occur anyway) or the problem is taken care of with
2371 if (! must_preallocate
)
2373 int partial_seen
= 0;
2374 poly_int64 copy_to_evaluate_size
= 0;
2377 for (i
= 0; i
< num_actuals
&& ! must_preallocate
; i
++)
2379 if (args
[i
].partial
> 0 && ! args
[i
].pass_on_stack
)
2381 else if (partial_seen
&& args
[i
].reg
== 0)
2382 must_preallocate
= 1;
2384 if (TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)) == BLKmode
2385 && (TREE_CODE (args
[i
].tree_value
) == CALL_EXPR
2386 || TREE_CODE (args
[i
].tree_value
) == TARGET_EXPR
2387 || TREE_CODE (args
[i
].tree_value
) == COND_EXPR
2388 || TREE_ADDRESSABLE (TREE_TYPE (args
[i
].tree_value
))))
2389 copy_to_evaluate_size
2390 += int_size_in_bytes (TREE_TYPE (args
[i
].tree_value
));
2393 if (maybe_ne (args_size
->constant
, 0)
2394 && maybe_ge (copy_to_evaluate_size
* 2, args_size
->constant
))
2395 must_preallocate
= 1;
2397 return must_preallocate
;
2400 /* If we preallocated stack space, compute the address of each argument
2401 and store it into the ARGS array.
2403 We need not ensure it is a valid memory address here; it will be
2404 validized when it is used.
2406 ARGBLOCK is an rtx for the address of the outgoing arguments. */
2409 compute_argument_addresses (struct arg_data
*args
, rtx argblock
, int num_actuals
)
2413 rtx arg_reg
= argblock
;
2415 poly_int64 arg_offset
= 0;
2417 if (GET_CODE (argblock
) == PLUS
)
2419 arg_reg
= XEXP (argblock
, 0);
2420 arg_offset
= rtx_to_poly_int64 (XEXP (argblock
, 1));
2423 for (i
= 0; i
< num_actuals
; i
++)
2425 rtx offset
= ARGS_SIZE_RTX (args
[i
].locate
.offset
);
2426 rtx slot_offset
= ARGS_SIZE_RTX (args
[i
].locate
.slot_offset
);
2428 unsigned int align
, boundary
;
2429 poly_uint64 units_on_stack
= 0;
2430 machine_mode partial_mode
= VOIDmode
;
2432 /* Skip this parm if it will not be passed on the stack. */
2433 if (! args
[i
].pass_on_stack
2435 && args
[i
].partial
== 0)
2438 if (TYPE_EMPTY_P (TREE_TYPE (args
[i
].tree_value
)))
2441 addr
= simplify_gen_binary (PLUS
, Pmode
, arg_reg
, offset
);
2442 addr
= plus_constant (Pmode
, addr
, arg_offset
);
2444 if (args
[i
].partial
!= 0)
2446 /* Only part of the parameter is being passed on the stack.
2447 Generate a simple memory reference of the correct size. */
2448 units_on_stack
= args
[i
].locate
.size
.constant
;
2449 poly_uint64 bits_on_stack
= units_on_stack
* BITS_PER_UNIT
;
2450 partial_mode
= int_mode_for_size (bits_on_stack
, 1).else_blk ();
2451 args
[i
].stack
= gen_rtx_MEM (partial_mode
, addr
);
2452 set_mem_size (args
[i
].stack
, units_on_stack
);
2456 args
[i
].stack
= gen_rtx_MEM (args
[i
].mode
, addr
);
2457 set_mem_attributes (args
[i
].stack
,
2458 TREE_TYPE (args
[i
].tree_value
), 1);
2460 align
= BITS_PER_UNIT
;
2461 boundary
= args
[i
].locate
.boundary
;
2462 poly_int64 offset_val
;
2463 if (args
[i
].locate
.where_pad
!= PAD_DOWNWARD
)
2465 else if (poly_int_rtx_p (offset
, &offset_val
))
2467 align
= least_bit_hwi (boundary
);
2468 unsigned int offset_align
2469 = known_alignment (offset_val
) * BITS_PER_UNIT
;
2470 if (offset_align
!= 0)
2471 align
= MIN (align
, offset_align
);
2473 set_mem_align (args
[i
].stack
, align
);
2475 addr
= simplify_gen_binary (PLUS
, Pmode
, arg_reg
, slot_offset
);
2476 addr
= plus_constant (Pmode
, addr
, arg_offset
);
2478 if (args
[i
].partial
!= 0)
2480 /* Only part of the parameter is being passed on the stack.
2481 Generate a simple memory reference of the correct size.
2483 args
[i
].stack_slot
= gen_rtx_MEM (partial_mode
, addr
);
2484 set_mem_size (args
[i
].stack_slot
, units_on_stack
);
2488 args
[i
].stack_slot
= gen_rtx_MEM (args
[i
].mode
, addr
);
2489 set_mem_attributes (args
[i
].stack_slot
,
2490 TREE_TYPE (args
[i
].tree_value
), 1);
2492 set_mem_align (args
[i
].stack_slot
, args
[i
].locate
.boundary
);
2494 /* Function incoming arguments may overlap with sibling call
2495 outgoing arguments and we cannot allow reordering of reads
2496 from function arguments with stores to outgoing arguments
2497 of sibling calls. */
2498 set_mem_alias_set (args
[i
].stack
, 0);
2499 set_mem_alias_set (args
[i
].stack_slot
, 0);
2504 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
2505 in a call instruction.
2507 FNDECL is the tree node for the target function. For an indirect call
2508 FNDECL will be NULL_TREE.
2510 ADDR is the operand 0 of CALL_EXPR for this call. */
2513 rtx_for_function_call (tree fndecl
, tree addr
)
2517 /* Get the function to call, in the form of RTL. */
2520 if (!TREE_USED (fndecl
) && fndecl
!= current_function_decl
)
2521 TREE_USED (fndecl
) = 1;
2523 /* Get a SYMBOL_REF rtx for the function address. */
2524 funexp
= XEXP (DECL_RTL (fndecl
), 0);
2527 /* Generate an rtx (probably a pseudo-register) for the address. */
2530 funexp
= expand_normal (addr
);
2531 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
2536 /* Return the static chain for this function, if any. */
2539 rtx_for_static_chain (const_tree fndecl_or_type
, bool incoming_p
)
2541 if (DECL_P (fndecl_or_type
) && !DECL_STATIC_CHAIN (fndecl_or_type
))
2544 return targetm
.calls
.static_chain (fndecl_or_type
, incoming_p
);
2547 /* Internal state for internal_arg_pointer_based_exp and its helpers. */
2550 /* Last insn that has been scanned by internal_arg_pointer_based_exp_scan,
2551 or NULL_RTX if none has been scanned yet. */
2552 rtx_insn
*scan_start
;
2553 /* Vector indexed by REGNO - FIRST_PSEUDO_REGISTER, recording if a pseudo is
2554 based on crtl->args.internal_arg_pointer. The element is NULL_RTX if the
2555 pseudo isn't based on it, a CONST_INT offset if the pseudo is based on it
2556 with fixed offset, or PC if this is with variable or unknown offset. */
2558 } internal_arg_pointer_exp_state
;
2560 static rtx
internal_arg_pointer_based_exp (const_rtx
, bool);
2562 /* Helper function for internal_arg_pointer_based_exp. Scan insns in
2563 the tail call sequence, starting with first insn that hasn't been
2564 scanned yet, and note for each pseudo on the LHS whether it is based
2565 on crtl->args.internal_arg_pointer or not, and what offset from that
2566 that pointer it has. */
2569 internal_arg_pointer_based_exp_scan (void)
2571 rtx_insn
*insn
, *scan_start
= internal_arg_pointer_exp_state
.scan_start
;
2573 if (scan_start
== NULL_RTX
)
2574 insn
= get_insns ();
2576 insn
= NEXT_INSN (scan_start
);
2580 rtx set
= single_set (insn
);
2581 if (set
&& REG_P (SET_DEST (set
)) && !HARD_REGISTER_P (SET_DEST (set
)))
2584 unsigned int idx
= REGNO (SET_DEST (set
)) - FIRST_PSEUDO_REGISTER
;
2585 /* Punt on pseudos set multiple times. */
2586 if (idx
< internal_arg_pointer_exp_state
.cache
.length ()
2587 && (internal_arg_pointer_exp_state
.cache
[idx
]
2591 val
= internal_arg_pointer_based_exp (SET_SRC (set
), false);
2592 if (val
!= NULL_RTX
)
2594 if (idx
>= internal_arg_pointer_exp_state
.cache
.length ())
2595 internal_arg_pointer_exp_state
.cache
2596 .safe_grow_cleared (idx
+ 1);
2597 internal_arg_pointer_exp_state
.cache
[idx
] = val
;
2600 if (NEXT_INSN (insn
) == NULL_RTX
)
2602 insn
= NEXT_INSN (insn
);
2605 internal_arg_pointer_exp_state
.scan_start
= scan_start
;
2608 /* Compute whether RTL is based on crtl->args.internal_arg_pointer. Return
2609 NULL_RTX if RTL isn't based on it, a CONST_INT offset if RTL is based on
2610 it with fixed offset, or PC if this is with variable or unknown offset.
2611 TOPLEVEL is true if the function is invoked at the topmost level. */
2614 internal_arg_pointer_based_exp (const_rtx rtl
, bool toplevel
)
2616 if (CONSTANT_P (rtl
))
2619 if (rtl
== crtl
->args
.internal_arg_pointer
)
2622 if (REG_P (rtl
) && HARD_REGISTER_P (rtl
))
2626 if (GET_CODE (rtl
) == PLUS
&& poly_int_rtx_p (XEXP (rtl
, 1), &offset
))
2628 rtx val
= internal_arg_pointer_based_exp (XEXP (rtl
, 0), toplevel
);
2629 if (val
== NULL_RTX
|| val
== pc_rtx
)
2631 return plus_constant (Pmode
, val
, offset
);
2634 /* When called at the topmost level, scan pseudo assignments in between the
2635 last scanned instruction in the tail call sequence and the latest insn
2636 in that sequence. */
2638 internal_arg_pointer_based_exp_scan ();
2642 unsigned int idx
= REGNO (rtl
) - FIRST_PSEUDO_REGISTER
;
2643 if (idx
< internal_arg_pointer_exp_state
.cache
.length ())
2644 return internal_arg_pointer_exp_state
.cache
[idx
];
2649 subrtx_iterator::array_type array
;
2650 FOR_EACH_SUBRTX (iter
, array
, rtl
, NONCONST
)
2652 const_rtx x
= *iter
;
2653 if (REG_P (x
) && internal_arg_pointer_based_exp (x
, false) != NULL_RTX
)
2656 iter
.skip_subrtxes ();
2662 /* Return true if SIZE bytes starting from address ADDR might overlap an
2663 already-clobbered argument area. This function is used to determine
2664 if we should give up a sibcall. */
2667 mem_might_overlap_already_clobbered_arg_p (rtx addr
, poly_uint64 size
)
2670 unsigned HOST_WIDE_INT start
, end
;
2673 if (bitmap_empty_p (stored_args_map
)
2674 && stored_args_watermark
== HOST_WIDE_INT_M1U
)
2676 val
= internal_arg_pointer_based_exp (addr
, true);
2677 if (val
== NULL_RTX
)
2679 else if (!poly_int_rtx_p (val
, &i
))
2682 if (known_eq (size
, 0U))
2685 if (STACK_GROWS_DOWNWARD
)
2686 i
-= crtl
->args
.pretend_args_size
;
2688 i
+= crtl
->args
.pretend_args_size
;
2690 if (ARGS_GROW_DOWNWARD
)
2693 /* We can ignore any references to the function's pretend args,
2694 which at this point would manifest as negative values of I. */
2695 if (known_le (i
, 0) && known_le (size
, poly_uint64 (-i
)))
2698 start
= maybe_lt (i
, 0) ? 0 : constant_lower_bound (i
);
2699 if (!(i
+ size
).is_constant (&end
))
2700 end
= HOST_WIDE_INT_M1U
;
2702 if (end
> stored_args_watermark
)
2705 end
= MIN (end
, SBITMAP_SIZE (stored_args_map
));
2706 for (unsigned HOST_WIDE_INT k
= start
; k
< end
; ++k
)
2707 if (bitmap_bit_p (stored_args_map
, k
))
2713 /* Do the register loads required for any wholly-register parms or any
2714 parms which are passed both on the stack and in a register. Their
2715 expressions were already evaluated.
2717 Mark all register-parms as living through the call, putting these USE
2718 insns in the CALL_INSN_FUNCTION_USAGE field.
2720 When IS_SIBCALL, perform the check_sibcall_argument_overlap
2721 checking, setting *SIBCALL_FAILURE if appropriate. */
2724 load_register_parameters (struct arg_data
*args
, int num_actuals
,
2725 rtx
*call_fusage
, int flags
, int is_sibcall
,
2726 int *sibcall_failure
)
2730 for (i
= 0; i
< num_actuals
; i
++)
2732 rtx reg
= ((flags
& ECF_SIBCALL
)
2733 ? args
[i
].tail_call_reg
: args
[i
].reg
);
2736 int partial
= args
[i
].partial
;
2738 poly_int64 size
= 0;
2739 HOST_WIDE_INT const_size
= 0;
2740 rtx_insn
*before_arg
= get_last_insn ();
2741 /* Set non-negative if we must move a word at a time, even if
2742 just one word (e.g, partial == 4 && mode == DFmode). Set
2743 to -1 if we just use a normal move insn. This value can be
2744 zero if the argument is a zero size structure. */
2746 if (GET_CODE (reg
) == PARALLEL
)
2750 gcc_assert (partial
% UNITS_PER_WORD
== 0);
2751 nregs
= partial
/ UNITS_PER_WORD
;
2753 else if (TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)) == BLKmode
)
2755 /* Variable-sized parameters should be described by a
2756 PARALLEL instead. */
2757 const_size
= int_size_in_bytes (TREE_TYPE (args
[i
].tree_value
));
2758 gcc_assert (const_size
>= 0);
2759 nregs
= (const_size
+ (UNITS_PER_WORD
- 1)) / UNITS_PER_WORD
;
2763 size
= GET_MODE_SIZE (args
[i
].mode
);
2765 /* Handle calls that pass values in multiple non-contiguous
2766 locations. The Irix 6 ABI has examples of this. */
2768 if (GET_CODE (reg
) == PARALLEL
)
2769 emit_group_move (reg
, args
[i
].parallel_value
);
2771 /* If simple case, just do move. If normal partial, store_one_arg
2772 has already loaded the register for us. In all other cases,
2773 load the register(s) from memory. */
2775 else if (nregs
== -1)
2777 emit_move_insn (reg
, args
[i
].value
);
2778 #ifdef BLOCK_REG_PADDING
2779 /* Handle case where we have a value that needs shifting
2780 up to the msb. eg. a QImode value and we're padding
2781 upward on a BYTES_BIG_ENDIAN machine. */
2782 if (args
[i
].locate
.where_pad
2783 == (BYTES_BIG_ENDIAN
? PAD_UPWARD
: PAD_DOWNWARD
))
2785 gcc_checking_assert (ordered_p (size
, UNITS_PER_WORD
));
2786 if (maybe_lt (size
, UNITS_PER_WORD
))
2790 = (UNITS_PER_WORD
- size
) * BITS_PER_UNIT
;
2792 /* Assigning REG here rather than a temp makes
2793 CALL_FUSAGE report the whole reg as used.
2794 Strictly speaking, the call only uses SIZE
2795 bytes at the msb end, but it doesn't seem worth
2796 generating rtl to say that. */
2797 reg
= gen_rtx_REG (word_mode
, REGNO (reg
));
2798 x
= expand_shift (LSHIFT_EXPR
, word_mode
,
2799 reg
, shift
, reg
, 1);
2801 emit_move_insn (reg
, x
);
2807 /* If we have pre-computed the values to put in the registers in
2808 the case of non-aligned structures, copy them in now. */
2810 else if (args
[i
].n_aligned_regs
!= 0)
2811 for (j
= 0; j
< args
[i
].n_aligned_regs
; j
++)
2812 emit_move_insn (gen_rtx_REG (word_mode
, REGNO (reg
) + j
),
2813 args
[i
].aligned_regs
[j
]);
2815 else if (partial
== 0 || args
[i
].pass_on_stack
)
2817 /* SIZE and CONST_SIZE are 0 for partial arguments and
2818 the size of a BLKmode type otherwise. */
2819 gcc_checking_assert (known_eq (size
, const_size
));
2820 rtx mem
= validize_mem (copy_rtx (args
[i
].value
));
2822 /* Check for overlap with already clobbered argument area,
2823 providing that this has non-zero size. */
2826 && (mem_might_overlap_already_clobbered_arg_p
2827 (XEXP (args
[i
].value
, 0), const_size
)))
2828 *sibcall_failure
= 1;
2830 if (const_size
% UNITS_PER_WORD
== 0
2831 || MEM_ALIGN (mem
) % BITS_PER_WORD
== 0)
2832 move_block_to_reg (REGNO (reg
), mem
, nregs
, args
[i
].mode
);
2836 move_block_to_reg (REGNO (reg
), mem
, nregs
- 1,
2838 rtx dest
= gen_rtx_REG (word_mode
, REGNO (reg
) + nregs
- 1);
2839 unsigned int bitoff
= (nregs
- 1) * BITS_PER_WORD
;
2840 unsigned int bitsize
= const_size
* BITS_PER_UNIT
- bitoff
;
2841 rtx x
= extract_bit_field (mem
, bitsize
, bitoff
, 1, dest
,
2842 word_mode
, word_mode
, false,
2844 if (BYTES_BIG_ENDIAN
)
2845 x
= expand_shift (LSHIFT_EXPR
, word_mode
, x
,
2846 BITS_PER_WORD
- bitsize
, dest
, 1);
2848 emit_move_insn (dest
, x
);
2851 /* Handle a BLKmode that needs shifting. */
2852 if (nregs
== 1 && const_size
< UNITS_PER_WORD
2853 #ifdef BLOCK_REG_PADDING
2854 && args
[i
].locate
.where_pad
== PAD_DOWNWARD
2860 rtx dest
= gen_rtx_REG (word_mode
, REGNO (reg
));
2861 int shift
= (UNITS_PER_WORD
- const_size
) * BITS_PER_UNIT
;
2862 enum tree_code dir
= (BYTES_BIG_ENDIAN
2863 ? RSHIFT_EXPR
: LSHIFT_EXPR
);
2866 x
= expand_shift (dir
, word_mode
, dest
, shift
, dest
, 1);
2868 emit_move_insn (dest
, x
);
2872 /* When a parameter is a block, and perhaps in other cases, it is
2873 possible that it did a load from an argument slot that was
2874 already clobbered. */
2876 && check_sibcall_argument_overlap (before_arg
, &args
[i
], 0))
2877 *sibcall_failure
= 1;
2879 /* Handle calls that pass values in multiple non-contiguous
2880 locations. The Irix 6 ABI has examples of this. */
2881 if (GET_CODE (reg
) == PARALLEL
)
2882 use_group_regs (call_fusage
, reg
);
2883 else if (nregs
== -1)
2884 use_reg_mode (call_fusage
, reg
,
2885 TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)));
2887 use_regs (call_fusage
, REGNO (reg
), nregs
);
2892 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
2893 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
2894 bytes, then we would need to push some additional bytes to pad the
2895 arguments. So, we try to compute an adjust to the stack pointer for an
2896 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
2897 bytes. Then, when the arguments are pushed the stack will be perfectly
2900 Return true if this optimization is possible, storing the adjustment
2901 in ADJUSTMENT_OUT and setting ARGS_SIZE->CONSTANT to the number of
2902 bytes that should be popped after the call. */
2905 combine_pending_stack_adjustment_and_call (poly_int64_pod
*adjustment_out
,
2906 poly_int64 unadjusted_args_size
,
2907 struct args_size
*args_size
,
2908 unsigned int preferred_unit_stack_boundary
)
2910 /* The number of bytes to pop so that the stack will be
2911 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
2912 poly_int64 adjustment
;
2913 /* The alignment of the stack after the arguments are pushed, if we
2914 just pushed the arguments without adjust the stack here. */
2915 unsigned HOST_WIDE_INT unadjusted_alignment
;
2917 if (!known_misalignment (stack_pointer_delta
+ unadjusted_args_size
,
2918 preferred_unit_stack_boundary
,
2919 &unadjusted_alignment
))
2922 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
2923 as possible -- leaving just enough left to cancel out the
2924 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
2925 PENDING_STACK_ADJUST is non-negative, and congruent to
2926 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
2928 /* Begin by trying to pop all the bytes. */
2929 unsigned HOST_WIDE_INT tmp_misalignment
;
2930 if (!known_misalignment (pending_stack_adjust
,
2931 preferred_unit_stack_boundary
,
2934 unadjusted_alignment
-= tmp_misalignment
;
2935 adjustment
= pending_stack_adjust
;
2936 /* Push enough additional bytes that the stack will be aligned
2937 after the arguments are pushed. */
2938 if (preferred_unit_stack_boundary
> 1 && unadjusted_alignment
)
2939 adjustment
-= preferred_unit_stack_boundary
- unadjusted_alignment
;
2941 /* We need to know whether the adjusted argument size
2942 (UNADJUSTED_ARGS_SIZE - ADJUSTMENT) constitutes an allocation
2943 or a deallocation. */
2944 if (!ordered_p (adjustment
, unadjusted_args_size
))
2947 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
2948 bytes after the call. The right number is the entire
2949 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
2950 by the arguments in the first place. */
2952 = pending_stack_adjust
- adjustment
+ unadjusted_args_size
;
2954 *adjustment_out
= adjustment
;
2958 /* Scan X expression if it does not dereference any argument slots
2959 we already clobbered by tail call arguments (as noted in stored_args_map
2961 Return nonzero if X expression dereferences such argument slots,
2965 check_sibcall_argument_overlap_1 (rtx x
)
2974 code
= GET_CODE (x
);
2976 /* We need not check the operands of the CALL expression itself. */
2981 return (mem_might_overlap_already_clobbered_arg_p
2982 (XEXP (x
, 0), GET_MODE_SIZE (GET_MODE (x
))));
2984 /* Scan all subexpressions. */
2985 fmt
= GET_RTX_FORMAT (code
);
2986 for (i
= 0; i
< GET_RTX_LENGTH (code
); i
++, fmt
++)
2990 if (check_sibcall_argument_overlap_1 (XEXP (x
, i
)))
2993 else if (*fmt
== 'E')
2995 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
2996 if (check_sibcall_argument_overlap_1 (XVECEXP (x
, i
, j
)))
3003 /* Scan sequence after INSN if it does not dereference any argument slots
3004 we already clobbered by tail call arguments (as noted in stored_args_map
3005 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
3006 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
3007 should be 0). Return nonzero if sequence after INSN dereferences such argument
3008 slots, zero otherwise. */
3011 check_sibcall_argument_overlap (rtx_insn
*insn
, struct arg_data
*arg
,
3012 int mark_stored_args_map
)
3014 poly_uint64 low
, high
;
3015 unsigned HOST_WIDE_INT const_low
, const_high
;
3017 if (insn
== NULL_RTX
)
3018 insn
= get_insns ();
3020 insn
= NEXT_INSN (insn
);
3022 for (; insn
; insn
= NEXT_INSN (insn
))
3024 && check_sibcall_argument_overlap_1 (PATTERN (insn
)))
3027 if (mark_stored_args_map
)
3029 if (ARGS_GROW_DOWNWARD
)
3030 low
= -arg
->locate
.slot_offset
.constant
- arg
->locate
.size
.constant
;
3032 low
= arg
->locate
.slot_offset
.constant
;
3033 high
= low
+ arg
->locate
.size
.constant
;
3035 const_low
= constant_lower_bound (low
);
3036 if (high
.is_constant (&const_high
))
3037 for (unsigned HOST_WIDE_INT i
= const_low
; i
< const_high
; ++i
)
3038 bitmap_set_bit (stored_args_map
, i
);
3040 stored_args_watermark
= MIN (stored_args_watermark
, const_low
);
3042 return insn
!= NULL_RTX
;
3045 /* Given that a function returns a value of mode MODE at the most
3046 significant end of hard register VALUE, shift VALUE left or right
3047 as specified by LEFT_P. Return true if some action was needed. */
3050 shift_return_value (machine_mode mode
, bool left_p
, rtx value
)
3052 gcc_assert (REG_P (value
) && HARD_REGISTER_P (value
));
3053 machine_mode value_mode
= GET_MODE (value
);
3054 poly_int64 shift
= GET_MODE_BITSIZE (value_mode
) - GET_MODE_BITSIZE (mode
);
3056 if (known_eq (shift
, 0))
3059 /* Use ashr rather than lshr for right shifts. This is for the benefit
3060 of the MIPS port, which requires SImode values to be sign-extended
3061 when stored in 64-bit registers. */
3062 if (!force_expand_binop (value_mode
, left_p
? ashl_optab
: ashr_optab
,
3063 value
, gen_int_shift_amount (value_mode
, shift
),
3064 value
, 1, OPTAB_WIDEN
))
3069 /* If X is a likely-spilled register value, copy it to a pseudo
3070 register and return that register. Return X otherwise. */
3073 avoid_likely_spilled_reg (rtx x
)
3078 && HARD_REGISTER_P (x
)
3079 && targetm
.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (x
))))
3081 /* Make sure that we generate a REG rather than a CONCAT.
3082 Moves into CONCATs can need nontrivial instructions,
3083 and the whole point of this function is to avoid
3084 using the hard register directly in such a situation. */
3085 generating_concat_p
= 0;
3086 new_rtx
= gen_reg_rtx (GET_MODE (x
));
3087 generating_concat_p
= 1;
3088 emit_move_insn (new_rtx
, x
);
3094 /* Helper function for expand_call.
3095 Return false is EXP is not implementable as a sibling call. */
3098 can_implement_as_sibling_call_p (tree exp
,
3099 rtx structure_value_addr
,
3101 int reg_parm_stack_space ATTRIBUTE_UNUSED
,
3105 const args_size
&args_size
)
3107 if (!targetm
.have_sibcall_epilogue ())
3109 maybe_complain_about_tail_call
3111 "machine description does not have"
3112 " a sibcall_epilogue instruction pattern");
3116 /* Doing sibling call optimization needs some work, since
3117 structure_value_addr can be allocated on the stack.
3118 It does not seem worth the effort since few optimizable
3119 sibling calls will return a structure. */
3120 if (structure_value_addr
!= NULL_RTX
)
3122 maybe_complain_about_tail_call (exp
, "callee returns a structure");
3126 #ifdef REG_PARM_STACK_SPACE
3127 /* If outgoing reg parm stack space changes, we can not do sibcall. */
3128 if (OUTGOING_REG_PARM_STACK_SPACE (funtype
)
3129 != OUTGOING_REG_PARM_STACK_SPACE (TREE_TYPE (current_function_decl
))
3130 || (reg_parm_stack_space
!= REG_PARM_STACK_SPACE (current_function_decl
)))
3132 maybe_complain_about_tail_call (exp
,
3133 "inconsistent size of stack space"
3134 " allocated for arguments which are"
3135 " passed in registers");
3140 /* Check whether the target is able to optimize the call
3142 if (!targetm
.function_ok_for_sibcall (fndecl
, exp
))
3144 maybe_complain_about_tail_call (exp
,
3145 "target is not able to optimize the"
3146 " call into a sibling call");
3150 /* Functions that do not return exactly once may not be sibcall
3152 if (flags
& ECF_RETURNS_TWICE
)
3154 maybe_complain_about_tail_call (exp
, "callee returns twice");
3157 if (flags
& ECF_NORETURN
)
3159 maybe_complain_about_tail_call (exp
, "callee does not return");
3163 if (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr
))))
3165 maybe_complain_about_tail_call (exp
, "volatile function type");
3169 /* If the called function is nested in the current one, it might access
3170 some of the caller's arguments, but could clobber them beforehand if
3171 the argument areas are shared. */
3172 if (fndecl
&& decl_function_context (fndecl
) == current_function_decl
)
3174 maybe_complain_about_tail_call (exp
, "nested function");
3178 /* If this function requires more stack slots than the current
3179 function, we cannot change it into a sibling call.
3180 crtl->args.pretend_args_size is not part of the
3181 stack allocated by our caller. */
3182 if (maybe_gt (args_size
.constant
,
3183 crtl
->args
.size
- crtl
->args
.pretend_args_size
))
3185 maybe_complain_about_tail_call (exp
,
3186 "callee required more stack slots"
3187 " than the caller");
3191 /* If the callee pops its own arguments, then it must pop exactly
3192 the same number of arguments as the current function. */
3193 if (maybe_ne (targetm
.calls
.return_pops_args (fndecl
, funtype
,
3194 args_size
.constant
),
3195 targetm
.calls
.return_pops_args (current_function_decl
,
3197 (current_function_decl
),
3200 maybe_complain_about_tail_call (exp
,
3201 "inconsistent number of"
3202 " popped arguments");
3206 if (!lang_hooks
.decls
.ok_for_sibcall (fndecl
))
3208 maybe_complain_about_tail_call (exp
, "frontend does not support"
3213 /* All checks passed. */
3217 /* Generate all the code for a CALL_EXPR exp
3218 and return an rtx for its value.
3219 Store the value in TARGET (specified as an rtx) if convenient.
3220 If the value is stored in TARGET then TARGET is returned.
3221 If IGNORE is nonzero, then we ignore the value of the function call. */
3224 expand_call (tree exp
, rtx target
, int ignore
)
3226 /* Nonzero if we are currently expanding a call. */
3227 static int currently_expanding_call
= 0;
3229 /* RTX for the function to be called. */
3231 /* Sequence of insns to perform a normal "call". */
3232 rtx_insn
*normal_call_insns
= NULL
;
3233 /* Sequence of insns to perform a tail "call". */
3234 rtx_insn
*tail_call_insns
= NULL
;
3235 /* Data type of the function. */
3237 tree type_arg_types
;
3239 /* Declaration of the function being called,
3240 or 0 if the function is computed (not known by name). */
3242 /* The type of the function being called. */
3244 bool try_tail_call
= CALL_EXPR_TAILCALL (exp
);
3245 bool must_tail_call
= CALL_EXPR_MUST_TAIL_CALL (exp
);
3248 /* Register in which non-BLKmode value will be returned,
3249 or 0 if no value or if value is BLKmode. */
3251 /* Address where we should return a BLKmode value;
3252 0 if value not BLKmode. */
3253 rtx structure_value_addr
= 0;
3254 /* Nonzero if that address is being passed by treating it as
3255 an extra, implicit first parameter. Otherwise,
3256 it is passed by being copied directly into struct_value_rtx. */
3257 int structure_value_addr_parm
= 0;
3258 /* Holds the value of implicit argument for the struct value. */
3259 tree structure_value_addr_value
= NULL_TREE
;
3260 /* Size of aggregate value wanted, or zero if none wanted
3261 or if we are using the non-reentrant PCC calling convention
3262 or expecting the value in registers. */
3263 poly_int64 struct_value_size
= 0;
3264 /* Nonzero if called function returns an aggregate in memory PCC style,
3265 by returning the address of where to find it. */
3266 int pcc_struct_value
= 0;
3267 rtx struct_value
= 0;
3269 /* Number of actual parameters in this call, including struct value addr. */
3271 /* Number of named args. Args after this are anonymous ones
3272 and they must all go on the stack. */
3274 /* Number of complex actual arguments that need to be split. */
3275 int num_complex_actuals
= 0;
3277 /* Vector of information about each argument.
3278 Arguments are numbered in the order they will be pushed,
3279 not the order they are written. */
3280 struct arg_data
*args
;
3282 /* Total size in bytes of all the stack-parms scanned so far. */
3283 struct args_size args_size
;
3284 struct args_size adjusted_args_size
;
3285 /* Size of arguments before any adjustments (such as rounding). */
3286 poly_int64 unadjusted_args_size
;
3287 /* Data on reg parms scanned so far. */
3288 CUMULATIVE_ARGS args_so_far_v
;
3289 cumulative_args_t args_so_far
;
3290 /* Nonzero if a reg parm has been scanned. */
3292 /* Nonzero if this is an indirect function call. */
3294 /* Nonzero if we must avoid push-insns in the args for this call.
3295 If stack space is allocated for register parameters, but not by the
3296 caller, then it is preallocated in the fixed part of the stack frame.
3297 So the entire argument block must then be preallocated (i.e., we
3298 ignore PUSH_ROUNDING in that case). */
3300 int must_preallocate
= !PUSH_ARGS
;
3302 /* Size of the stack reserved for parameter registers. */
3303 int reg_parm_stack_space
= 0;
3305 /* Address of space preallocated for stack parms
3306 (on machines that lack push insns), or 0 if space not preallocated. */
3309 /* Mask of ECF_ and ERF_ flags. */
3311 int return_flags
= 0;
3312 #ifdef REG_PARM_STACK_SPACE
3313 /* Define the boundary of the register parm stack space that needs to be
3315 int low_to_save
, high_to_save
;
3316 rtx save_area
= 0; /* Place that it is saved */
3319 unsigned int initial_highest_arg_in_use
= highest_outgoing_arg_in_use
;
3320 char *initial_stack_usage_map
= stack_usage_map
;
3321 unsigned HOST_WIDE_INT initial_stack_usage_watermark
= stack_usage_watermark
;
3322 char *stack_usage_map_buf
= NULL
;
3324 poly_int64 old_stack_allocated
;
3326 /* State variables to track stack modifications. */
3327 rtx old_stack_level
= 0;
3328 int old_stack_arg_under_construction
= 0;
3329 poly_int64 old_pending_adj
= 0;
3330 int old_inhibit_defer_pop
= inhibit_defer_pop
;
3332 /* Some stack pointer alterations we make are performed via
3333 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
3334 which we then also need to save/restore along the way. */
3335 poly_int64 old_stack_pointer_delta
= 0;
3338 tree addr
= CALL_EXPR_FN (exp
);
3340 /* The alignment of the stack, in bits. */
3341 unsigned HOST_WIDE_INT preferred_stack_boundary
;
3342 /* The alignment of the stack, in bytes. */
3343 unsigned HOST_WIDE_INT preferred_unit_stack_boundary
;
3344 /* The static chain value to use for this call. */
3345 rtx static_chain_value
;
3346 /* See if this is "nothrow" function call. */
3347 if (TREE_NOTHROW (exp
))
3348 flags
|= ECF_NOTHROW
;
3350 /* See if we can find a DECL-node for the actual function, and get the
3351 function attributes (flags) from the function decl or type node. */
3352 fndecl
= get_callee_fndecl (exp
);
3355 fntype
= TREE_TYPE (fndecl
);
3356 flags
|= flags_from_decl_or_type (fndecl
);
3357 return_flags
|= decl_return_flags (fndecl
);
3361 fntype
= TREE_TYPE (TREE_TYPE (addr
));
3362 flags
|= flags_from_decl_or_type (fntype
);
3363 if (CALL_EXPR_BY_DESCRIPTOR (exp
))
3364 flags
|= ECF_BY_DESCRIPTOR
;
3366 rettype
= TREE_TYPE (exp
);
3368 struct_value
= targetm
.calls
.struct_value_rtx (fntype
, 0);
3370 /* Warn if this value is an aggregate type,
3371 regardless of which calling convention we are using for it. */
3372 if (AGGREGATE_TYPE_P (rettype
))
3373 warning (OPT_Waggregate_return
, "function call has aggregate value");
3375 /* If the result of a non looping pure or const function call is
3376 ignored (or void), and none of its arguments are volatile, we can
3377 avoid expanding the call and just evaluate the arguments for
3379 if ((flags
& (ECF_CONST
| ECF_PURE
))
3380 && (!(flags
& ECF_LOOPING_CONST_OR_PURE
))
3381 && (ignore
|| target
== const0_rtx
3382 || TYPE_MODE (rettype
) == VOIDmode
))
3384 bool volatilep
= false;
3386 call_expr_arg_iterator iter
;
3388 FOR_EACH_CALL_EXPR_ARG (arg
, iter
, exp
)
3389 if (TREE_THIS_VOLATILE (arg
))
3397 FOR_EACH_CALL_EXPR_ARG (arg
, iter
, exp
)
3398 expand_expr (arg
, const0_rtx
, VOIDmode
, EXPAND_NORMAL
);
3403 #ifdef REG_PARM_STACK_SPACE
3404 reg_parm_stack_space
= REG_PARM_STACK_SPACE (!fndecl
? fntype
: fndecl
);
3407 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl
? fntype
: TREE_TYPE (fndecl
)))
3408 && reg_parm_stack_space
> 0 && PUSH_ARGS
)
3409 must_preallocate
= 1;
3411 /* Set up a place to return a structure. */
3413 /* Cater to broken compilers. */
3414 if (aggregate_value_p (exp
, fntype
))
3416 /* This call returns a big structure. */
3417 flags
&= ~(ECF_CONST
| ECF_PURE
| ECF_LOOPING_CONST_OR_PURE
);
3419 #ifdef PCC_STATIC_STRUCT_RETURN
3421 pcc_struct_value
= 1;
3423 #else /* not PCC_STATIC_STRUCT_RETURN */
3425 if (!poly_int_tree_p (TYPE_SIZE_UNIT (rettype
), &struct_value_size
))
3426 struct_value_size
= -1;
3428 /* Even if it is semantically safe to use the target as the return
3429 slot, it may be not sufficiently aligned for the return type. */
3430 if (CALL_EXPR_RETURN_SLOT_OPT (exp
)
3433 /* If rettype is addressable, we may not create a temporary.
3434 If target is properly aligned at runtime and the compiler
3435 just doesn't know about it, it will work fine, otherwise it
3437 && (TREE_ADDRESSABLE (rettype
)
3438 || !(MEM_ALIGN (target
) < TYPE_ALIGN (rettype
)
3439 && targetm
.slow_unaligned_access (TYPE_MODE (rettype
),
3440 MEM_ALIGN (target
)))))
3441 structure_value_addr
= XEXP (target
, 0);
3444 /* For variable-sized objects, we must be called with a target
3445 specified. If we were to allocate space on the stack here,
3446 we would have no way of knowing when to free it. */
3447 rtx d
= assign_temp (rettype
, 1, 1);
3448 structure_value_addr
= XEXP (d
, 0);
3452 #endif /* not PCC_STATIC_STRUCT_RETURN */
3455 /* Figure out the amount to which the stack should be aligned. */
3456 preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
3459 struct cgraph_rtl_info
*i
= cgraph_node::rtl_info (fndecl
);
3460 /* Without automatic stack alignment, we can't increase preferred
3461 stack boundary. With automatic stack alignment, it is
3462 unnecessary since unless we can guarantee that all callers will
3463 align the outgoing stack properly, callee has to align its
3466 && i
->preferred_incoming_stack_boundary
3467 && i
->preferred_incoming_stack_boundary
< preferred_stack_boundary
)
3468 preferred_stack_boundary
= i
->preferred_incoming_stack_boundary
;
3471 /* Operand 0 is a pointer-to-function; get the type of the function. */
3472 funtype
= TREE_TYPE (addr
);
3473 gcc_assert (POINTER_TYPE_P (funtype
));
3474 funtype
= TREE_TYPE (funtype
);
3476 /* Count whether there are actual complex arguments that need to be split
3477 into their real and imaginary parts. Munge the type_arg_types
3478 appropriately here as well. */
3479 if (targetm
.calls
.split_complex_arg
)
3481 call_expr_arg_iterator iter
;
3483 FOR_EACH_CALL_EXPR_ARG (arg
, iter
, exp
)
3485 tree type
= TREE_TYPE (arg
);
3486 if (type
&& TREE_CODE (type
) == COMPLEX_TYPE
3487 && targetm
.calls
.split_complex_arg (type
))
3488 num_complex_actuals
++;
3490 type_arg_types
= split_complex_types (TYPE_ARG_TYPES (funtype
));
3493 type_arg_types
= TYPE_ARG_TYPES (funtype
);
3495 if (flags
& ECF_MAY_BE_ALLOCA
)
3496 cfun
->calls_alloca
= 1;
3498 /* If struct_value_rtx is 0, it means pass the address
3499 as if it were an extra parameter. Put the argument expression
3500 in structure_value_addr_value. */
3501 if (structure_value_addr
&& struct_value
== 0)
3503 /* If structure_value_addr is a REG other than
3504 virtual_outgoing_args_rtx, we can use always use it. If it
3505 is not a REG, we must always copy it into a register.
3506 If it is virtual_outgoing_args_rtx, we must copy it to another
3507 register in some cases. */
3508 rtx temp
= (!REG_P (structure_value_addr
)
3509 || (ACCUMULATE_OUTGOING_ARGS
3510 && stack_arg_under_construction
3511 && structure_value_addr
== virtual_outgoing_args_rtx
)
3512 ? copy_addr_to_reg (convert_memory_address
3513 (Pmode
, structure_value_addr
))
3514 : structure_value_addr
);
3516 structure_value_addr_value
=
3517 make_tree (build_pointer_type (TREE_TYPE (funtype
)), temp
);
3518 structure_value_addr_parm
= 1;
3521 /* Count the arguments and set NUM_ACTUALS. */
3523 call_expr_nargs (exp
) + num_complex_actuals
+ structure_value_addr_parm
;
3525 /* Compute number of named args.
3526 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
3528 if (type_arg_types
!= 0)
3530 = (list_length (type_arg_types
)
3531 /* Count the struct value address, if it is passed as a parm. */
3532 + structure_value_addr_parm
);
3534 /* If we know nothing, treat all args as named. */
3535 n_named_args
= num_actuals
;
3537 /* Start updating where the next arg would go.
3539 On some machines (such as the PA) indirect calls have a different
3540 calling convention than normal calls. The fourth argument in
3541 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
3543 INIT_CUMULATIVE_ARGS (args_so_far_v
, funtype
, NULL_RTX
, fndecl
, n_named_args
);
3544 args_so_far
= pack_cumulative_args (&args_so_far_v
);
3546 /* Now possibly adjust the number of named args.
3547 Normally, don't include the last named arg if anonymous args follow.
3548 We do include the last named arg if
3549 targetm.calls.strict_argument_naming() returns nonzero.
3550 (If no anonymous args follow, the result of list_length is actually
3551 one too large. This is harmless.)
3553 If targetm.calls.pretend_outgoing_varargs_named() returns
3554 nonzero, and targetm.calls.strict_argument_naming() returns zero,
3555 this machine will be able to place unnamed args that were passed
3556 in registers into the stack. So treat all args as named. This
3557 allows the insns emitting for a specific argument list to be
3558 independent of the function declaration.
3560 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
3561 we do not have any reliable way to pass unnamed args in
3562 registers, so we must force them into memory. */
3564 if (type_arg_types
!= 0
3565 && targetm
.calls
.strict_argument_naming (args_so_far
))
3567 else if (type_arg_types
!= 0
3568 && ! targetm
.calls
.pretend_outgoing_varargs_named (args_so_far
))
3569 /* Don't include the last named arg. */
3572 /* Treat all args as named. */
3573 n_named_args
= num_actuals
;
3575 /* Make a vector to hold all the information about each arg. */
3576 args
= XCNEWVEC (struct arg_data
, num_actuals
);
3578 /* Build up entries in the ARGS array, compute the size of the
3579 arguments into ARGS_SIZE, etc. */
3580 initialize_argument_information (num_actuals
, args
, &args_size
,
3582 structure_value_addr_value
, fndecl
, fntype
,
3583 args_so_far
, reg_parm_stack_space
,
3584 &old_stack_level
, &old_pending_adj
,
3585 &must_preallocate
, &flags
,
3586 &try_tail_call
, CALL_FROM_THUNK_P (exp
));
3589 must_preallocate
= 1;
3591 /* Now make final decision about preallocating stack space. */
3592 must_preallocate
= finalize_must_preallocate (must_preallocate
,
3596 /* If the structure value address will reference the stack pointer, we
3597 must stabilize it. We don't need to do this if we know that we are
3598 not going to adjust the stack pointer in processing this call. */
3600 if (structure_value_addr
3601 && (reg_mentioned_p (virtual_stack_dynamic_rtx
, structure_value_addr
)
3602 || reg_mentioned_p (virtual_outgoing_args_rtx
,
3603 structure_value_addr
))
3605 || (!ACCUMULATE_OUTGOING_ARGS
3606 && maybe_ne (args_size
.constant
, 0))))
3607 structure_value_addr
= copy_to_reg (structure_value_addr
);
3609 /* Tail calls can make things harder to debug, and we've traditionally
3610 pushed these optimizations into -O2. Don't try if we're already
3611 expanding a call, as that means we're an argument. Don't try if
3612 there's cleanups, as we know there's code to follow the call. */
3614 if (currently_expanding_call
++ != 0
3615 || !flag_optimize_sibling_calls
3617 || dbg_cnt (tail_call
) == false)
3620 /* If the user has marked the function as requiring tail-call
3621 optimization, attempt it. */
3625 /* Rest of purposes for tail call optimizations to fail. */
3627 try_tail_call
= can_implement_as_sibling_call_p (exp
,
3628 structure_value_addr
,
3630 reg_parm_stack_space
,
3632 flags
, addr
, args_size
);
3634 /* Check if caller and callee disagree in promotion of function
3638 machine_mode caller_mode
, caller_promoted_mode
;
3639 machine_mode callee_mode
, callee_promoted_mode
;
3640 int caller_unsignedp
, callee_unsignedp
;
3641 tree caller_res
= DECL_RESULT (current_function_decl
);
3643 caller_unsignedp
= TYPE_UNSIGNED (TREE_TYPE (caller_res
));
3644 caller_mode
= DECL_MODE (caller_res
);
3645 callee_unsignedp
= TYPE_UNSIGNED (TREE_TYPE (funtype
));
3646 callee_mode
= TYPE_MODE (TREE_TYPE (funtype
));
3647 caller_promoted_mode
3648 = promote_function_mode (TREE_TYPE (caller_res
), caller_mode
,
3650 TREE_TYPE (current_function_decl
), 1);
3651 callee_promoted_mode
3652 = promote_function_mode (TREE_TYPE (funtype
), callee_mode
,
3655 if (caller_mode
!= VOIDmode
3656 && (caller_promoted_mode
!= callee_promoted_mode
3657 || ((caller_mode
!= caller_promoted_mode
3658 || callee_mode
!= callee_promoted_mode
)
3659 && (caller_unsignedp
!= callee_unsignedp
3660 || partial_subreg_p (caller_mode
, callee_mode
)))))
3663 maybe_complain_about_tail_call (exp
,
3664 "caller and callee disagree in"
3665 " promotion of function"
3670 /* Ensure current function's preferred stack boundary is at least
3671 what we need. Stack alignment may also increase preferred stack
3673 if (crtl
->preferred_stack_boundary
< preferred_stack_boundary
)
3674 crtl
->preferred_stack_boundary
= preferred_stack_boundary
;
3676 preferred_stack_boundary
= crtl
->preferred_stack_boundary
;
3678 preferred_unit_stack_boundary
= preferred_stack_boundary
/ BITS_PER_UNIT
;
3680 /* We want to make two insn chains; one for a sibling call, the other
3681 for a normal call. We will select one of the two chains after
3682 initial RTL generation is complete. */
3683 for (pass
= try_tail_call
? 0 : 1; pass
< 2; pass
++)
3685 int sibcall_failure
= 0;
3686 /* We want to emit any pending stack adjustments before the tail
3687 recursion "call". That way we know any adjustment after the tail
3688 recursion call can be ignored if we indeed use the tail
3690 saved_pending_stack_adjust save
;
3691 rtx_insn
*insns
, *before_call
, *after_args
;
3696 /* State variables we need to save and restore between
3698 save_pending_stack_adjust (&save
);
3701 flags
&= ~ECF_SIBCALL
;
3703 flags
|= ECF_SIBCALL
;
3705 /* Other state variables that we must reinitialize each time
3706 through the loop (that are not initialized by the loop itself). */
3710 /* Start a new sequence for the normal call case.
3712 From this point on, if the sibling call fails, we want to set
3713 sibcall_failure instead of continuing the loop. */
3716 /* Don't let pending stack adjusts add up to too much.
3717 Also, do all pending adjustments now if there is any chance
3718 this might be a call to alloca or if we are expanding a sibling
3720 Also do the adjustments before a throwing call, otherwise
3721 exception handling can fail; PR 19225. */
3722 if (maybe_ge (pending_stack_adjust
, 32)
3723 || (maybe_ne (pending_stack_adjust
, 0)
3724 && (flags
& ECF_MAY_BE_ALLOCA
))
3725 || (maybe_ne (pending_stack_adjust
, 0)
3726 && flag_exceptions
&& !(flags
& ECF_NOTHROW
))
3728 do_pending_stack_adjust ();
3730 /* Precompute any arguments as needed. */
3732 precompute_arguments (num_actuals
, args
);
3734 /* Now we are about to start emitting insns that can be deleted
3735 if a libcall is deleted. */
3736 if (pass
&& (flags
& ECF_MALLOC
))
3740 && crtl
->stack_protect_guard
3741 && targetm
.stack_protect_runtime_enabled_p ())
3742 stack_protect_epilogue ();
3744 adjusted_args_size
= args_size
;
3745 /* Compute the actual size of the argument block required. The variable
3746 and constant sizes must be combined, the size may have to be rounded,
3747 and there may be a minimum required size. When generating a sibcall
3748 pattern, do not round up, since we'll be re-using whatever space our
3750 unadjusted_args_size
3751 = compute_argument_block_size (reg_parm_stack_space
,
3752 &adjusted_args_size
,
3755 : preferred_stack_boundary
));
3757 old_stack_allocated
= stack_pointer_delta
- pending_stack_adjust
;
3759 /* The argument block when performing a sibling call is the
3760 incoming argument block. */
3763 argblock
= crtl
->args
.internal_arg_pointer
;
3764 if (STACK_GROWS_DOWNWARD
)
3766 = plus_constant (Pmode
, argblock
, crtl
->args
.pretend_args_size
);
3769 = plus_constant (Pmode
, argblock
, -crtl
->args
.pretend_args_size
);
3771 HOST_WIDE_INT map_size
= constant_lower_bound (args_size
.constant
);
3772 stored_args_map
= sbitmap_alloc (map_size
);
3773 bitmap_clear (stored_args_map
);
3774 stored_args_watermark
= HOST_WIDE_INT_M1U
;
3777 /* If we have no actual push instructions, or shouldn't use them,
3778 make space for all args right now. */
3779 else if (adjusted_args_size
.var
!= 0)
3781 if (old_stack_level
== 0)
3783 emit_stack_save (SAVE_BLOCK
, &old_stack_level
);
3784 old_stack_pointer_delta
= stack_pointer_delta
;
3785 old_pending_adj
= pending_stack_adjust
;
3786 pending_stack_adjust
= 0;
3787 /* stack_arg_under_construction says whether a stack arg is
3788 being constructed at the old stack level. Pushing the stack
3789 gets a clean outgoing argument block. */
3790 old_stack_arg_under_construction
= stack_arg_under_construction
;
3791 stack_arg_under_construction
= 0;
3793 argblock
= push_block (ARGS_SIZE_RTX (adjusted_args_size
), 0, 0);
3794 if (flag_stack_usage_info
)
3795 current_function_has_unbounded_dynamic_stack_size
= 1;
3799 /* Note that we must go through the motions of allocating an argument
3800 block even if the size is zero because we may be storing args
3801 in the area reserved for register arguments, which may be part of
3804 poly_int64 needed
= adjusted_args_size
.constant
;
3806 /* Store the maximum argument space used. It will be pushed by
3807 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
3810 crtl
->outgoing_args_size
= upper_bound (crtl
->outgoing_args_size
,
3813 if (must_preallocate
)
3815 if (ACCUMULATE_OUTGOING_ARGS
)
3817 /* Since the stack pointer will never be pushed, it is
3818 possible for the evaluation of a parm to clobber
3819 something we have already written to the stack.
3820 Since most function calls on RISC machines do not use
3821 the stack, this is uncommon, but must work correctly.
3823 Therefore, we save any area of the stack that was already
3824 written and that we are using. Here we set up to do this
3825 by making a new stack usage map from the old one. The
3826 actual save will be done by store_one_arg.
3828 Another approach might be to try to reorder the argument
3829 evaluations to avoid this conflicting stack usage. */
3831 /* Since we will be writing into the entire argument area,
3832 the map must be allocated for its entire size, not just
3833 the part that is the responsibility of the caller. */
3834 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl
? fntype
: TREE_TYPE (fndecl
))))
3835 needed
+= reg_parm_stack_space
;
3837 poly_int64 limit
= needed
;
3838 if (ARGS_GROW_DOWNWARD
)
3841 /* For polynomial sizes, this is the maximum possible
3842 size needed for arguments with a constant size
3844 HOST_WIDE_INT const_limit
= constant_lower_bound (limit
);
3845 highest_outgoing_arg_in_use
3846 = MAX (initial_highest_arg_in_use
, const_limit
);
3848 free (stack_usage_map_buf
);
3849 stack_usage_map_buf
= XNEWVEC (char, highest_outgoing_arg_in_use
);
3850 stack_usage_map
= stack_usage_map_buf
;
3852 if (initial_highest_arg_in_use
)
3853 memcpy (stack_usage_map
, initial_stack_usage_map
,
3854 initial_highest_arg_in_use
);
3856 if (initial_highest_arg_in_use
!= highest_outgoing_arg_in_use
)
3857 memset (&stack_usage_map
[initial_highest_arg_in_use
], 0,
3858 (highest_outgoing_arg_in_use
3859 - initial_highest_arg_in_use
));
3862 /* The address of the outgoing argument list must not be
3863 copied to a register here, because argblock would be left
3864 pointing to the wrong place after the call to
3865 allocate_dynamic_stack_space below. */
3867 argblock
= virtual_outgoing_args_rtx
;
3871 /* Try to reuse some or all of the pending_stack_adjust
3872 to get this space. */
3873 if (inhibit_defer_pop
== 0
3874 && (combine_pending_stack_adjustment_and_call
3876 unadjusted_args_size
,
3877 &adjusted_args_size
,
3878 preferred_unit_stack_boundary
)))
3880 /* combine_pending_stack_adjustment_and_call computes
3881 an adjustment before the arguments are allocated.
3882 Account for them and see whether or not the stack
3883 needs to go up or down. */
3884 needed
= unadjusted_args_size
- needed
;
3887 combine_pending_stack_adjustment_and_call. */
3888 gcc_checking_assert (ordered_p (needed
, 0));
3889 if (maybe_lt (needed
, 0))
3891 /* We're releasing stack space. */
3892 /* ??? We can avoid any adjustment at all if we're
3893 already aligned. FIXME. */
3894 pending_stack_adjust
= -needed
;
3895 do_pending_stack_adjust ();
3899 /* We need to allocate space. We'll do that in
3900 push_block below. */
3901 pending_stack_adjust
= 0;
3904 /* Special case this because overhead of `push_block' in
3905 this case is non-trivial. */
3906 if (known_eq (needed
, 0))
3907 argblock
= virtual_outgoing_args_rtx
;
3910 rtx needed_rtx
= gen_int_mode (needed
, Pmode
);
3911 argblock
= push_block (needed_rtx
, 0, 0);
3912 if (ARGS_GROW_DOWNWARD
)
3913 argblock
= plus_constant (Pmode
, argblock
, needed
);
3916 /* We only really need to call `copy_to_reg' in the case
3917 where push insns are going to be used to pass ARGBLOCK
3918 to a function call in ARGS. In that case, the stack
3919 pointer changes value from the allocation point to the
3920 call point, and hence the value of
3921 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
3922 as well always do it. */
3923 argblock
= copy_to_reg (argblock
);
3928 if (ACCUMULATE_OUTGOING_ARGS
)
3930 /* The save/restore code in store_one_arg handles all
3931 cases except one: a constructor call (including a C
3932 function returning a BLKmode struct) to initialize
3934 if (stack_arg_under_construction
)
3938 (adjusted_args_size
.constant
3939 + (OUTGOING_REG_PARM_STACK_SPACE (!fndecl
? fntype
3940 : TREE_TYPE (fndecl
))
3941 ? 0 : reg_parm_stack_space
), Pmode
));
3942 if (old_stack_level
== 0)
3944 emit_stack_save (SAVE_BLOCK
, &old_stack_level
);
3945 old_stack_pointer_delta
= stack_pointer_delta
;
3946 old_pending_adj
= pending_stack_adjust
;
3947 pending_stack_adjust
= 0;
3948 /* stack_arg_under_construction says whether a stack
3949 arg is being constructed at the old stack level.
3950 Pushing the stack gets a clean outgoing argument
3952 old_stack_arg_under_construction
3953 = stack_arg_under_construction
;
3954 stack_arg_under_construction
= 0;
3955 /* Make a new map for the new argument list. */
3956 free (stack_usage_map_buf
);
3957 stack_usage_map_buf
= XCNEWVEC (char, highest_outgoing_arg_in_use
);
3958 stack_usage_map
= stack_usage_map_buf
;
3959 highest_outgoing_arg_in_use
= 0;
3960 stack_usage_watermark
= HOST_WIDE_INT_M1U
;
3962 /* We can pass TRUE as the 4th argument because we just
3963 saved the stack pointer and will restore it right after
3965 allocate_dynamic_stack_space (push_size
, 0, BIGGEST_ALIGNMENT
,
3969 /* If argument evaluation might modify the stack pointer,
3970 copy the address of the argument list to a register. */
3971 for (i
= 0; i
< num_actuals
; i
++)
3972 if (args
[i
].pass_on_stack
)
3974 argblock
= copy_addr_to_reg (argblock
);
3979 compute_argument_addresses (args
, argblock
, num_actuals
);
3981 /* Stack is properly aligned, pops can't safely be deferred during
3982 the evaluation of the arguments. */
3985 /* Precompute all register parameters. It isn't safe to compute
3986 anything once we have started filling any specific hard regs.
3987 TLS symbols sometimes need a call to resolve. Precompute
3988 register parameters before any stack pointer manipulation
3989 to avoid unaligned stack in the called function. */
3990 precompute_register_parameters (num_actuals
, args
, ®_parm_seen
);
3994 /* Perform stack alignment before the first push (the last arg). */
3996 && maybe_gt (adjusted_args_size
.constant
, reg_parm_stack_space
)
3997 && maybe_ne (adjusted_args_size
.constant
, unadjusted_args_size
))
3999 /* When the stack adjustment is pending, we get better code
4000 by combining the adjustments. */
4001 if (maybe_ne (pending_stack_adjust
, 0)
4002 && ! inhibit_defer_pop
4003 && (combine_pending_stack_adjustment_and_call
4004 (&pending_stack_adjust
,
4005 unadjusted_args_size
,
4006 &adjusted_args_size
,
4007 preferred_unit_stack_boundary
)))
4008 do_pending_stack_adjust ();
4009 else if (argblock
== 0)
4010 anti_adjust_stack (gen_int_mode (adjusted_args_size
.constant
4011 - unadjusted_args_size
,
4014 /* Now that the stack is properly aligned, pops can't safely
4015 be deferred during the evaluation of the arguments. */
4018 /* Record the maximum pushed stack space size. We need to delay
4019 doing it this far to take into account the optimization done
4020 by combine_pending_stack_adjustment_and_call. */
4021 if (flag_stack_usage_info
4022 && !ACCUMULATE_OUTGOING_ARGS
4024 && adjusted_args_size
.var
== 0)
4026 poly_int64 pushed
= (adjusted_args_size
.constant
4027 + pending_stack_adjust
);
4028 current_function_pushed_stack_size
4029 = upper_bound (current_function_pushed_stack_size
, pushed
);
4032 funexp
= rtx_for_function_call (fndecl
, addr
);
4034 if (CALL_EXPR_STATIC_CHAIN (exp
))
4035 static_chain_value
= expand_normal (CALL_EXPR_STATIC_CHAIN (exp
));
4037 static_chain_value
= 0;
4039 #ifdef REG_PARM_STACK_SPACE
4040 /* Save the fixed argument area if it's part of the caller's frame and
4041 is clobbered by argument setup for this call. */
4042 if (ACCUMULATE_OUTGOING_ARGS
&& pass
)
4043 save_area
= save_fixed_argument_area (reg_parm_stack_space
, argblock
,
4044 &low_to_save
, &high_to_save
);
4047 /* Now store (and compute if necessary) all non-register parms.
4048 These come before register parms, since they can require block-moves,
4049 which could clobber the registers used for register parms.
4050 Parms which have partial registers are not stored here,
4051 but we do preallocate space here if they want that. */
4053 for (i
= 0; i
< num_actuals
; i
++)
4055 if (args
[i
].reg
== 0 || args
[i
].pass_on_stack
)
4057 rtx_insn
*before_arg
= get_last_insn ();
4059 /* We don't allow passing huge (> 2^30 B) arguments
4060 by value. It would cause an overflow later on. */
4061 if (constant_lower_bound (adjusted_args_size
.constant
)
4062 >= (1 << (HOST_BITS_PER_INT
- 2)))
4064 sorry ("passing too large argument on stack");
4068 if (store_one_arg (&args
[i
], argblock
, flags
,
4069 adjusted_args_size
.var
!= 0,
4070 reg_parm_stack_space
)
4072 && check_sibcall_argument_overlap (before_arg
,
4074 sibcall_failure
= 1;
4079 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)),
4080 gen_rtx_USE (VOIDmode
, args
[i
].stack
),
4084 /* If we have a parm that is passed in registers but not in memory
4085 and whose alignment does not permit a direct copy into registers,
4086 make a group of pseudos that correspond to each register that we
4088 if (STRICT_ALIGNMENT
)
4089 store_unaligned_arguments_into_pseudos (args
, num_actuals
);
4091 /* Now store any partially-in-registers parm.
4092 This is the last place a block-move can happen. */
4094 for (i
= 0; i
< num_actuals
; i
++)
4095 if (args
[i
].partial
!= 0 && ! args
[i
].pass_on_stack
)
4097 rtx_insn
*before_arg
= get_last_insn ();
4099 /* On targets with weird calling conventions (e.g. PA) it's
4100 hard to ensure that all cases of argument overlap between
4101 stack and registers work. Play it safe and bail out. */
4102 if (ARGS_GROW_DOWNWARD
&& !STACK_GROWS_DOWNWARD
)
4104 sibcall_failure
= 1;
4108 if (store_one_arg (&args
[i
], argblock
, flags
,
4109 adjusted_args_size
.var
!= 0,
4110 reg_parm_stack_space
)
4112 && check_sibcall_argument_overlap (before_arg
,
4114 sibcall_failure
= 1;
4117 bool any_regs
= false;
4118 for (i
= 0; i
< num_actuals
; i
++)
4119 if (args
[i
].reg
!= NULL_RTX
)
4122 targetm
.calls
.call_args (args
[i
].reg
, funtype
);
4125 targetm
.calls
.call_args (pc_rtx
, funtype
);
4127 /* Figure out the register where the value, if any, will come back. */
4129 if (TYPE_MODE (rettype
) != VOIDmode
4130 && ! structure_value_addr
)
4132 if (pcc_struct_value
)
4133 valreg
= hard_function_value (build_pointer_type (rettype
),
4134 fndecl
, NULL
, (pass
== 0));
4136 valreg
= hard_function_value (rettype
, fndecl
, fntype
,
4139 /* If VALREG is a PARALLEL whose first member has a zero
4140 offset, use that. This is for targets such as m68k that
4141 return the same value in multiple places. */
4142 if (GET_CODE (valreg
) == PARALLEL
)
4144 rtx elem
= XVECEXP (valreg
, 0, 0);
4145 rtx where
= XEXP (elem
, 0);
4146 rtx offset
= XEXP (elem
, 1);
4147 if (offset
== const0_rtx
4148 && GET_MODE (where
) == GET_MODE (valreg
))
4153 /* If register arguments require space on the stack and stack space
4154 was not preallocated, allocate stack space here for arguments
4155 passed in registers. */
4156 if (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl
? fntype
: TREE_TYPE (fndecl
)))
4157 && !ACCUMULATE_OUTGOING_ARGS
4158 && must_preallocate
== 0 && reg_parm_stack_space
> 0)
4159 anti_adjust_stack (GEN_INT (reg_parm_stack_space
));
4161 /* Pass the function the address in which to return a
4163 if (pass
!= 0 && structure_value_addr
&& ! structure_value_addr_parm
)
4165 structure_value_addr
4166 = convert_memory_address (Pmode
, structure_value_addr
);
4167 emit_move_insn (struct_value
,
4169 force_operand (structure_value_addr
,
4172 if (REG_P (struct_value
))
4173 use_reg (&call_fusage
, struct_value
);
4176 after_args
= get_last_insn ();
4177 funexp
= prepare_call_address (fndecl
? fndecl
: fntype
, funexp
,
4178 static_chain_value
, &call_fusage
,
4179 reg_parm_seen
, flags
);
4181 load_register_parameters (args
, num_actuals
, &call_fusage
, flags
,
4182 pass
== 0, &sibcall_failure
);
4184 /* Save a pointer to the last insn before the call, so that we can
4185 later safely search backwards to find the CALL_INSN. */
4186 before_call
= get_last_insn ();
4188 /* Set up next argument register. For sibling calls on machines
4189 with register windows this should be the incoming register. */
4191 next_arg_reg
= targetm
.calls
.function_incoming_arg (args_so_far
,
4196 next_arg_reg
= targetm
.calls
.function_arg (args_so_far
,
4197 VOIDmode
, void_type_node
,
4200 if (pass
== 1 && (return_flags
& ERF_RETURNS_ARG
))
4202 int arg_nr
= return_flags
& ERF_RETURN_ARG_MASK
;
4203 arg_nr
= num_actuals
- arg_nr
- 1;
4205 && arg_nr
< num_actuals
4209 && GET_MODE (args
[arg_nr
].reg
) == GET_MODE (valreg
))
4211 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args
[arg_nr
].tree_value
)),
4212 gen_rtx_SET (valreg
, args
[arg_nr
].reg
),
4215 /* All arguments and registers used for the call must be set up by
4218 /* Stack must be properly aligned now. */
4220 || multiple_p (stack_pointer_delta
,
4221 preferred_unit_stack_boundary
));
4223 /* Generate the actual call instruction. */
4224 emit_call_1 (funexp
, exp
, fndecl
, funtype
, unadjusted_args_size
,
4225 adjusted_args_size
.constant
, struct_value_size
,
4226 next_arg_reg
, valreg
, old_inhibit_defer_pop
, call_fusage
,
4227 flags
, args_so_far
);
4231 rtx_call_insn
*last
;
4232 rtx datum
= NULL_RTX
;
4233 if (fndecl
!= NULL_TREE
)
4235 datum
= XEXP (DECL_RTL (fndecl
), 0);
4236 gcc_assert (datum
!= NULL_RTX
4237 && GET_CODE (datum
) == SYMBOL_REF
);
4239 last
= last_call_insn ();
4240 add_reg_note (last
, REG_CALL_DECL
, datum
);
4243 /* If the call setup or the call itself overlaps with anything
4244 of the argument setup we probably clobbered our call address.
4245 In that case we can't do sibcalls. */
4247 && check_sibcall_argument_overlap (after_args
, 0, 0))
4248 sibcall_failure
= 1;
4250 /* If a non-BLKmode value is returned at the most significant end
4251 of a register, shift the register right by the appropriate amount
4252 and update VALREG accordingly. BLKmode values are handled by the
4253 group load/store machinery below. */
4254 if (!structure_value_addr
4255 && !pcc_struct_value
4256 && TYPE_MODE (rettype
) != VOIDmode
4257 && TYPE_MODE (rettype
) != BLKmode
4259 && targetm
.calls
.return_in_msb (rettype
))
4261 if (shift_return_value (TYPE_MODE (rettype
), false, valreg
))
4262 sibcall_failure
= 1;
4263 valreg
= gen_rtx_REG (TYPE_MODE (rettype
), REGNO (valreg
));
4266 if (pass
&& (flags
& ECF_MALLOC
))
4268 rtx temp
= gen_reg_rtx (GET_MODE (valreg
));
4269 rtx_insn
*last
, *insns
;
4271 /* The return value from a malloc-like function is a pointer. */
4272 if (TREE_CODE (rettype
) == POINTER_TYPE
)
4273 mark_reg_pointer (temp
, MALLOC_ABI_ALIGNMENT
);
4275 emit_move_insn (temp
, valreg
);
4277 /* The return value from a malloc-like function can not alias
4279 last
= get_last_insn ();
4280 add_reg_note (last
, REG_NOALIAS
, temp
);
4282 /* Write out the sequence. */
4283 insns
= get_insns ();
4289 /* For calls to `setjmp', etc., inform
4290 function.c:setjmp_warnings that it should complain if
4291 nonvolatile values are live. For functions that cannot
4292 return, inform flow that control does not fall through. */
4294 if ((flags
& ECF_NORETURN
) || pass
== 0)
4296 /* The barrier must be emitted
4297 immediately after the CALL_INSN. Some ports emit more
4298 than just a CALL_INSN above, so we must search for it here. */
4300 rtx_insn
*last
= get_last_insn ();
4301 while (!CALL_P (last
))
4303 last
= PREV_INSN (last
);
4304 /* There was no CALL_INSN? */
4305 gcc_assert (last
!= before_call
);
4308 emit_barrier_after (last
);
4310 /* Stack adjustments after a noreturn call are dead code.
4311 However when NO_DEFER_POP is in effect, we must preserve
4312 stack_pointer_delta. */
4313 if (inhibit_defer_pop
== 0)
4315 stack_pointer_delta
= old_stack_allocated
;
4316 pending_stack_adjust
= 0;
4320 /* If value type not void, return an rtx for the value. */
4322 if (TYPE_MODE (rettype
) == VOIDmode
4324 target
= const0_rtx
;
4325 else if (structure_value_addr
)
4327 if (target
== 0 || !MEM_P (target
))
4330 = gen_rtx_MEM (TYPE_MODE (rettype
),
4331 memory_address (TYPE_MODE (rettype
),
4332 structure_value_addr
));
4333 set_mem_attributes (target
, rettype
, 1);
4336 else if (pcc_struct_value
)
4338 /* This is the special C++ case where we need to
4339 know what the true target was. We take care to
4340 never use this value more than once in one expression. */
4341 target
= gen_rtx_MEM (TYPE_MODE (rettype
),
4342 copy_to_reg (valreg
));
4343 set_mem_attributes (target
, rettype
, 1);
4345 /* Handle calls that return values in multiple non-contiguous locations.
4346 The Irix 6 ABI has examples of this. */
4347 else if (GET_CODE (valreg
) == PARALLEL
)
4350 target
= emit_group_move_into_temps (valreg
);
4351 else if (rtx_equal_p (target
, valreg
))
4353 else if (GET_CODE (target
) == PARALLEL
)
4354 /* Handle the result of a emit_group_move_into_temps
4355 call in the previous pass. */
4356 emit_group_move (target
, valreg
);
4358 emit_group_store (target
, valreg
, rettype
,
4359 int_size_in_bytes (rettype
));
4362 && GET_MODE (target
) == TYPE_MODE (rettype
)
4363 && GET_MODE (target
) == GET_MODE (valreg
))
4365 bool may_overlap
= false;
4367 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
4368 reg to a plain register. */
4369 if (!REG_P (target
) || HARD_REGISTER_P (target
))
4370 valreg
= avoid_likely_spilled_reg (valreg
);
4372 /* If TARGET is a MEM in the argument area, and we have
4373 saved part of the argument area, then we can't store
4374 directly into TARGET as it may get overwritten when we
4375 restore the argument save area below. Don't work too
4376 hard though and simply force TARGET to a register if it
4377 is a MEM; the optimizer is quite likely to sort it out. */
4378 if (ACCUMULATE_OUTGOING_ARGS
&& pass
&& MEM_P (target
))
4379 for (i
= 0; i
< num_actuals
; i
++)
4380 if (args
[i
].save_area
)
4387 target
= copy_to_reg (valreg
);
4390 /* TARGET and VALREG cannot be equal at this point
4391 because the latter would not have
4392 REG_FUNCTION_VALUE_P true, while the former would if
4393 it were referring to the same register.
4395 If they refer to the same register, this move will be
4396 a no-op, except when function inlining is being
4398 emit_move_insn (target
, valreg
);
4400 /* If we are setting a MEM, this code must be executed.
4401 Since it is emitted after the call insn, sibcall
4402 optimization cannot be performed in that case. */
4404 sibcall_failure
= 1;
4408 target
= copy_to_reg (avoid_likely_spilled_reg (valreg
));
4410 /* If we promoted this return value, make the proper SUBREG.
4411 TARGET might be const0_rtx here, so be careful. */
4413 && TYPE_MODE (rettype
) != BLKmode
4414 && GET_MODE (target
) != TYPE_MODE (rettype
))
4416 tree type
= rettype
;
4417 int unsignedp
= TYPE_UNSIGNED (type
);
4420 /* Ensure we promote as expected, and get the new unsignedness. */
4421 pmode
= promote_function_mode (type
, TYPE_MODE (type
), &unsignedp
,
4423 gcc_assert (GET_MODE (target
) == pmode
);
4425 poly_uint64 offset
= subreg_lowpart_offset (TYPE_MODE (type
),
4427 target
= gen_rtx_SUBREG (TYPE_MODE (type
), target
, offset
);
4428 SUBREG_PROMOTED_VAR_P (target
) = 1;
4429 SUBREG_PROMOTED_SET (target
, unsignedp
);
4432 /* If size of args is variable or this was a constructor call for a stack
4433 argument, restore saved stack-pointer value. */
4435 if (old_stack_level
)
4437 rtx_insn
*prev
= get_last_insn ();
4439 emit_stack_restore (SAVE_BLOCK
, old_stack_level
);
4440 stack_pointer_delta
= old_stack_pointer_delta
;
4442 fixup_args_size_notes (prev
, get_last_insn (), stack_pointer_delta
);
4444 pending_stack_adjust
= old_pending_adj
;
4445 old_stack_allocated
= stack_pointer_delta
- pending_stack_adjust
;
4446 stack_arg_under_construction
= old_stack_arg_under_construction
;
4447 highest_outgoing_arg_in_use
= initial_highest_arg_in_use
;
4448 stack_usage_map
= initial_stack_usage_map
;
4449 stack_usage_watermark
= initial_stack_usage_watermark
;
4450 sibcall_failure
= 1;
4452 else if (ACCUMULATE_OUTGOING_ARGS
&& pass
)
4454 #ifdef REG_PARM_STACK_SPACE
4456 restore_fixed_argument_area (save_area
, argblock
,
4457 high_to_save
, low_to_save
);
4460 /* If we saved any argument areas, restore them. */
4461 for (i
= 0; i
< num_actuals
; i
++)
4462 if (args
[i
].save_area
)
4464 machine_mode save_mode
= GET_MODE (args
[i
].save_area
);
4466 = gen_rtx_MEM (save_mode
,
4467 memory_address (save_mode
,
4468 XEXP (args
[i
].stack_slot
, 0)));
4470 if (save_mode
!= BLKmode
)
4471 emit_move_insn (stack_area
, args
[i
].save_area
);
4473 emit_block_move (stack_area
, args
[i
].save_area
,
4475 (args
[i
].locate
.size
.constant
, Pmode
)),
4476 BLOCK_OP_CALL_PARM
);
4479 highest_outgoing_arg_in_use
= initial_highest_arg_in_use
;
4480 stack_usage_map
= initial_stack_usage_map
;
4481 stack_usage_watermark
= initial_stack_usage_watermark
;
4484 /* If this was alloca, record the new stack level. */
4485 if (flags
& ECF_MAY_BE_ALLOCA
)
4486 record_new_stack_level ();
4488 /* Free up storage we no longer need. */
4489 for (i
= 0; i
< num_actuals
; ++i
)
4490 free (args
[i
].aligned_regs
);
4492 targetm
.calls
.end_call_args ();
4494 insns
= get_insns ();
4499 tail_call_insns
= insns
;
4501 /* Restore the pending stack adjustment now that we have
4502 finished generating the sibling call sequence. */
4504 restore_pending_stack_adjust (&save
);
4506 /* Prepare arg structure for next iteration. */
4507 for (i
= 0; i
< num_actuals
; i
++)
4510 args
[i
].aligned_regs
= 0;
4514 sbitmap_free (stored_args_map
);
4515 internal_arg_pointer_exp_state
.scan_start
= NULL
;
4516 internal_arg_pointer_exp_state
.cache
.release ();
4520 normal_call_insns
= insns
;
4522 /* Verify that we've deallocated all the stack we used. */
4523 gcc_assert ((flags
& ECF_NORETURN
)
4524 || known_eq (old_stack_allocated
,
4526 - pending_stack_adjust
));
4529 /* If something prevents making this a sibling call,
4530 zero out the sequence. */
4531 if (sibcall_failure
)
4532 tail_call_insns
= NULL
;
4537 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
4538 arguments too, as argument area is now clobbered by the call. */
4539 if (tail_call_insns
)
4541 emit_insn (tail_call_insns
);
4542 crtl
->tail_call_emit
= true;
4546 emit_insn (normal_call_insns
);
4548 /* Ideally we'd emit a message for all of the ways that it could
4550 maybe_complain_about_tail_call (exp
, "tail call production failed");
4553 currently_expanding_call
--;
4555 free (stack_usage_map_buf
);
4560 /* A sibling call sequence invalidates any REG_EQUIV notes made for
4561 this function's incoming arguments.
4563 At the start of RTL generation we know the only REG_EQUIV notes
4564 in the rtl chain are those for incoming arguments, so we can look
4565 for REG_EQUIV notes between the start of the function and the
4566 NOTE_INSN_FUNCTION_BEG.
4568 This is (slight) overkill. We could keep track of the highest
4569 argument we clobber and be more selective in removing notes, but it
4570 does not seem to be worth the effort. */
4573 fixup_tail_calls (void)
4577 for (insn
= get_insns (); insn
; insn
= NEXT_INSN (insn
))
4581 /* There are never REG_EQUIV notes for the incoming arguments
4582 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
4584 && NOTE_KIND (insn
) == NOTE_INSN_FUNCTION_BEG
)
4587 note
= find_reg_note (insn
, REG_EQUIV
, 0);
4589 remove_note (insn
, note
);
4590 note
= find_reg_note (insn
, REG_EQUIV
, 0);
4595 /* Traverse a list of TYPES and expand all complex types into their
4598 split_complex_types (tree types
)
4602 /* Before allocating memory, check for the common case of no complex. */
4603 for (p
= types
; p
; p
= TREE_CHAIN (p
))
4605 tree type
= TREE_VALUE (p
);
4606 if (TREE_CODE (type
) == COMPLEX_TYPE
4607 && targetm
.calls
.split_complex_arg (type
))
4613 types
= copy_list (types
);
4615 for (p
= types
; p
; p
= TREE_CHAIN (p
))
4617 tree complex_type
= TREE_VALUE (p
);
4619 if (TREE_CODE (complex_type
) == COMPLEX_TYPE
4620 && targetm
.calls
.split_complex_arg (complex_type
))
4624 /* Rewrite complex type with component type. */
4625 TREE_VALUE (p
) = TREE_TYPE (complex_type
);
4626 next
= TREE_CHAIN (p
);
4628 /* Add another component type for the imaginary part. */
4629 imag
= build_tree_list (NULL_TREE
, TREE_VALUE (p
));
4630 TREE_CHAIN (p
) = imag
;
4631 TREE_CHAIN (imag
) = next
;
4633 /* Skip the newly created node. */
4641 /* Output a library call to function ORGFUN (a SYMBOL_REF rtx)
4642 for a value of mode OUTMODE,
4643 with NARGS different arguments, passed as ARGS.
4644 Store the return value if RETVAL is nonzero: store it in VALUE if
4645 VALUE is nonnull, otherwise pick a convenient location. In either
4646 case return the location of the stored value.
4648 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
4649 `const' calls, LCT_PURE for `pure' calls, or another LCT_ value for
4650 other types of library calls. */
4653 emit_library_call_value_1 (int retval
, rtx orgfun
, rtx value
,
4654 enum libcall_type fn_type
,
4655 machine_mode outmode
, int nargs
, rtx_mode_t
*args
)
4657 /* Total size in bytes of all the stack-parms scanned so far. */
4658 struct args_size args_size
;
4659 /* Size of arguments before any adjustments (such as rounding). */
4660 struct args_size original_args_size
;
4663 /* Todo, choose the correct decl type of orgfun. Sadly this information
4664 isn't present here, so we default to native calling abi here. */
4665 tree fndecl ATTRIBUTE_UNUSED
= NULL_TREE
; /* library calls default to host calling abi ? */
4666 tree fntype ATTRIBUTE_UNUSED
= NULL_TREE
; /* library calls default to host calling abi ? */
4669 CUMULATIVE_ARGS args_so_far_v
;
4670 cumulative_args_t args_so_far
;
4677 struct locate_and_pad_arg_data locate
;
4681 int old_inhibit_defer_pop
= inhibit_defer_pop
;
4682 rtx call_fusage
= 0;
4685 int pcc_struct_value
= 0;
4686 poly_int64 struct_value_size
= 0;
4688 int reg_parm_stack_space
= 0;
4690 rtx_insn
*before_call
;
4691 bool have_push_fusage
;
4692 tree tfom
; /* type_for_mode (outmode, 0) */
4694 #ifdef REG_PARM_STACK_SPACE
4695 /* Define the boundary of the register parm stack space that needs to be
4697 int low_to_save
= 0, high_to_save
= 0;
4698 rtx save_area
= 0; /* Place that it is saved. */
4701 /* Size of the stack reserved for parameter registers. */
4702 unsigned int initial_highest_arg_in_use
= highest_outgoing_arg_in_use
;
4703 char *initial_stack_usage_map
= stack_usage_map
;
4704 unsigned HOST_WIDE_INT initial_stack_usage_watermark
= stack_usage_watermark
;
4705 char *stack_usage_map_buf
= NULL
;
4707 rtx struct_value
= targetm
.calls
.struct_value_rtx (0, 0);
4709 #ifdef REG_PARM_STACK_SPACE
4710 reg_parm_stack_space
= REG_PARM_STACK_SPACE ((tree
) 0);
4713 /* By default, library functions cannot throw. */
4714 flags
= ECF_NOTHROW
;
4727 flags
|= ECF_NORETURN
;
4730 flags
&= ~ECF_NOTHROW
;
4732 case LCT_RETURNS_TWICE
:
4733 flags
= ECF_RETURNS_TWICE
;
4738 /* Ensure current function's preferred stack boundary is at least
4740 if (crtl
->preferred_stack_boundary
< PREFERRED_STACK_BOUNDARY
)
4741 crtl
->preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
4743 /* If this kind of value comes back in memory,
4744 decide where in memory it should come back. */
4745 if (outmode
!= VOIDmode
)
4747 tfom
= lang_hooks
.types
.type_for_mode (outmode
, 0);
4748 if (aggregate_value_p (tfom
, 0))
4750 #ifdef PCC_STATIC_STRUCT_RETURN
4752 = hard_function_value (build_pointer_type (tfom
), 0, 0, 0);
4753 mem_value
= gen_rtx_MEM (outmode
, pointer_reg
);
4754 pcc_struct_value
= 1;
4756 value
= gen_reg_rtx (outmode
);
4757 #else /* not PCC_STATIC_STRUCT_RETURN */
4758 struct_value_size
= GET_MODE_SIZE (outmode
);
4759 if (value
!= 0 && MEM_P (value
))
4762 mem_value
= assign_temp (tfom
, 1, 1);
4764 /* This call returns a big structure. */
4765 flags
&= ~(ECF_CONST
| ECF_PURE
| ECF_LOOPING_CONST_OR_PURE
);
4769 tfom
= void_type_node
;
4771 /* ??? Unfinished: must pass the memory address as an argument. */
4773 /* Copy all the libcall-arguments out of the varargs data
4774 and into a vector ARGVEC.
4776 Compute how to pass each argument. We only support a very small subset
4777 of the full argument passing conventions to limit complexity here since
4778 library functions shouldn't have many args. */
4780 argvec
= XALLOCAVEC (struct arg
, nargs
+ 1);
4781 memset (argvec
, 0, (nargs
+ 1) * sizeof (struct arg
));
4783 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
4784 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far_v
, outmode
, fun
);
4786 INIT_CUMULATIVE_ARGS (args_so_far_v
, NULL_TREE
, fun
, 0, nargs
);
4788 args_so_far
= pack_cumulative_args (&args_so_far_v
);
4790 args_size
.constant
= 0;
4797 /* If there's a structure value address to be passed,
4798 either pass it in the special place, or pass it as an extra argument. */
4799 if (mem_value
&& struct_value
== 0 && ! pcc_struct_value
)
4801 rtx addr
= XEXP (mem_value
, 0);
4805 /* Make sure it is a reasonable operand for a move or push insn. */
4806 if (!REG_P (addr
) && !MEM_P (addr
)
4807 && !(CONSTANT_P (addr
)
4808 && targetm
.legitimate_constant_p (Pmode
, addr
)))
4809 addr
= force_operand (addr
, NULL_RTX
);
4811 argvec
[count
].value
= addr
;
4812 argvec
[count
].mode
= Pmode
;
4813 argvec
[count
].partial
= 0;
4815 argvec
[count
].reg
= targetm
.calls
.function_arg (args_so_far
,
4816 Pmode
, NULL_TREE
, true);
4817 gcc_assert (targetm
.calls
.arg_partial_bytes (args_so_far
, Pmode
,
4818 NULL_TREE
, 1) == 0);
4820 locate_and_pad_parm (Pmode
, NULL_TREE
,
4821 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4824 argvec
[count
].reg
!= 0,
4826 reg_parm_stack_space
, 0,
4827 NULL_TREE
, &args_size
, &argvec
[count
].locate
);
4829 if (argvec
[count
].reg
== 0 || argvec
[count
].partial
!= 0
4830 || reg_parm_stack_space
> 0)
4831 args_size
.constant
+= argvec
[count
].locate
.size
.constant
;
4833 targetm
.calls
.function_arg_advance (args_so_far
, Pmode
, (tree
) 0, true);
4838 for (unsigned int i
= 0; count
< nargs
; i
++, count
++)
4840 rtx val
= args
[i
].first
;
4841 machine_mode mode
= args
[i
].second
;
4844 /* We cannot convert the arg value to the mode the library wants here;
4845 must do it earlier where we know the signedness of the arg. */
4846 gcc_assert (mode
!= BLKmode
4847 && (GET_MODE (val
) == mode
|| GET_MODE (val
) == VOIDmode
));
4849 /* Make sure it is a reasonable operand for a move or push insn. */
4850 if (!REG_P (val
) && !MEM_P (val
)
4851 && !(CONSTANT_P (val
) && targetm
.legitimate_constant_p (mode
, val
)))
4852 val
= force_operand (val
, NULL_RTX
);
4854 if (pass_by_reference (&args_so_far_v
, mode
, NULL_TREE
, 1))
4858 = !reference_callee_copied (&args_so_far_v
, mode
, NULL_TREE
, 1);
4860 /* If this was a CONST function, it is now PURE since it now
4862 if (flags
& ECF_CONST
)
4864 flags
&= ~ECF_CONST
;
4868 if (MEM_P (val
) && !must_copy
)
4870 tree val_expr
= MEM_EXPR (val
);
4872 mark_addressable (val_expr
);
4877 slot
= assign_temp (lang_hooks
.types
.type_for_mode (mode
, 0),
4879 emit_move_insn (slot
, val
);
4882 call_fusage
= gen_rtx_EXPR_LIST (VOIDmode
,
4883 gen_rtx_USE (VOIDmode
, slot
),
4886 call_fusage
= gen_rtx_EXPR_LIST (VOIDmode
,
4887 gen_rtx_CLOBBER (VOIDmode
,
4892 val
= force_operand (XEXP (slot
, 0), NULL_RTX
);
4895 mode
= promote_function_mode (NULL_TREE
, mode
, &unsigned_p
, NULL_TREE
, 0);
4896 argvec
[count
].mode
= mode
;
4897 argvec
[count
].value
= convert_modes (mode
, GET_MODE (val
), val
, unsigned_p
);
4898 argvec
[count
].reg
= targetm
.calls
.function_arg (args_so_far
, mode
,
4901 argvec
[count
].partial
4902 = targetm
.calls
.arg_partial_bytes (args_so_far
, mode
, NULL_TREE
, 1);
4904 if (argvec
[count
].reg
== 0
4905 || argvec
[count
].partial
!= 0
4906 || reg_parm_stack_space
> 0)
4908 locate_and_pad_parm (mode
, NULL_TREE
,
4909 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4912 argvec
[count
].reg
!= 0,
4914 reg_parm_stack_space
, argvec
[count
].partial
,
4915 NULL_TREE
, &args_size
, &argvec
[count
].locate
);
4916 args_size
.constant
+= argvec
[count
].locate
.size
.constant
;
4917 gcc_assert (!argvec
[count
].locate
.size
.var
);
4919 #ifdef BLOCK_REG_PADDING
4921 /* The argument is passed entirely in registers. See at which
4922 end it should be padded. */
4923 argvec
[count
].locate
.where_pad
=
4924 BLOCK_REG_PADDING (mode
, NULL_TREE
,
4925 known_le (GET_MODE_SIZE (mode
), UNITS_PER_WORD
));
4928 targetm
.calls
.function_arg_advance (args_so_far
, mode
, (tree
) 0, true);
4931 /* If this machine requires an external definition for library
4932 functions, write one out. */
4933 assemble_external_libcall (fun
);
4935 original_args_size
= args_size
;
4936 args_size
.constant
= (aligned_upper_bound (args_size
.constant
4937 + stack_pointer_delta
,
4939 - stack_pointer_delta
);
4941 args_size
.constant
= upper_bound (args_size
.constant
,
4942 reg_parm_stack_space
);
4944 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl
? fntype
: TREE_TYPE (fndecl
))))
4945 args_size
.constant
-= reg_parm_stack_space
;
4947 crtl
->outgoing_args_size
= upper_bound (crtl
->outgoing_args_size
,
4948 args_size
.constant
);
4950 if (flag_stack_usage_info
&& !ACCUMULATE_OUTGOING_ARGS
)
4952 poly_int64 pushed
= args_size
.constant
+ pending_stack_adjust
;
4953 current_function_pushed_stack_size
4954 = upper_bound (current_function_pushed_stack_size
, pushed
);
4957 if (ACCUMULATE_OUTGOING_ARGS
)
4959 /* Since the stack pointer will never be pushed, it is possible for
4960 the evaluation of a parm to clobber something we have already
4961 written to the stack. Since most function calls on RISC machines
4962 do not use the stack, this is uncommon, but must work correctly.
4964 Therefore, we save any area of the stack that was already written
4965 and that we are using. Here we set up to do this by making a new
4966 stack usage map from the old one.
4968 Another approach might be to try to reorder the argument
4969 evaluations to avoid this conflicting stack usage. */
4971 needed
= args_size
.constant
;
4973 /* Since we will be writing into the entire argument area, the
4974 map must be allocated for its entire size, not just the part that
4975 is the responsibility of the caller. */
4976 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl
? fntype
: TREE_TYPE (fndecl
))))
4977 needed
+= reg_parm_stack_space
;
4979 poly_int64 limit
= needed
;
4980 if (ARGS_GROW_DOWNWARD
)
4983 /* For polynomial sizes, this is the maximum possible size needed
4984 for arguments with a constant size and offset. */
4985 HOST_WIDE_INT const_limit
= constant_lower_bound (limit
);
4986 highest_outgoing_arg_in_use
= MAX (initial_highest_arg_in_use
,
4989 stack_usage_map_buf
= XNEWVEC (char, highest_outgoing_arg_in_use
);
4990 stack_usage_map
= stack_usage_map_buf
;
4992 if (initial_highest_arg_in_use
)
4993 memcpy (stack_usage_map
, initial_stack_usage_map
,
4994 initial_highest_arg_in_use
);
4996 if (initial_highest_arg_in_use
!= highest_outgoing_arg_in_use
)
4997 memset (&stack_usage_map
[initial_highest_arg_in_use
], 0,
4998 highest_outgoing_arg_in_use
- initial_highest_arg_in_use
);
5001 /* We must be careful to use virtual regs before they're instantiated,
5002 and real regs afterwards. Loop optimization, for example, can create
5003 new libcalls after we've instantiated the virtual regs, and if we
5004 use virtuals anyway, they won't match the rtl patterns. */
5006 if (virtuals_instantiated
)
5007 argblock
= plus_constant (Pmode
, stack_pointer_rtx
,
5008 STACK_POINTER_OFFSET
);
5010 argblock
= virtual_outgoing_args_rtx
;
5015 argblock
= push_block (gen_int_mode (args_size
.constant
, Pmode
), 0, 0);
5018 /* We push args individually in reverse order, perform stack alignment
5019 before the first push (the last arg). */
5021 anti_adjust_stack (gen_int_mode (args_size
.constant
5022 - original_args_size
.constant
,
5027 #ifdef REG_PARM_STACK_SPACE
5028 if (ACCUMULATE_OUTGOING_ARGS
)
5030 /* The argument list is the property of the called routine and it
5031 may clobber it. If the fixed area has been used for previous
5032 parameters, we must save and restore it. */
5033 save_area
= save_fixed_argument_area (reg_parm_stack_space
, argblock
,
5034 &low_to_save
, &high_to_save
);
5038 /* When expanding a normal call, args are stored in push order,
5039 which is the reverse of what we have here. */
5040 bool any_regs
= false;
5041 for (int i
= nargs
; i
-- > 0; )
5042 if (argvec
[i
].reg
!= NULL_RTX
)
5044 targetm
.calls
.call_args (argvec
[i
].reg
, NULL_TREE
);
5048 targetm
.calls
.call_args (pc_rtx
, NULL_TREE
);
5050 /* Push the args that need to be pushed. */
5052 have_push_fusage
= false;
5054 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
5055 are to be pushed. */
5056 for (count
= 0; count
< nargs
; count
++, argnum
--)
5058 machine_mode mode
= argvec
[argnum
].mode
;
5059 rtx val
= argvec
[argnum
].value
;
5060 rtx reg
= argvec
[argnum
].reg
;
5061 int partial
= argvec
[argnum
].partial
;
5062 unsigned int parm_align
= argvec
[argnum
].locate
.boundary
;
5063 poly_int64 lower_bound
= 0, upper_bound
= 0;
5065 if (! (reg
!= 0 && partial
== 0))
5069 if (ACCUMULATE_OUTGOING_ARGS
)
5071 /* If this is being stored into a pre-allocated, fixed-size,
5072 stack area, save any previous data at that location. */
5074 if (ARGS_GROW_DOWNWARD
)
5076 /* stack_slot is negative, but we want to index stack_usage_map
5077 with positive values. */
5078 upper_bound
= -argvec
[argnum
].locate
.slot_offset
.constant
+ 1;
5079 lower_bound
= upper_bound
- argvec
[argnum
].locate
.size
.constant
;
5083 lower_bound
= argvec
[argnum
].locate
.slot_offset
.constant
;
5084 upper_bound
= lower_bound
+ argvec
[argnum
].locate
.size
.constant
;
5087 if (stack_region_maybe_used_p (lower_bound
, upper_bound
,
5088 reg_parm_stack_space
))
5090 /* We need to make a save area. */
5092 = argvec
[argnum
].locate
.size
.constant
* BITS_PER_UNIT
;
5093 machine_mode save_mode
5094 = int_mode_for_size (size
, 1).else_blk ();
5096 = plus_constant (Pmode
, argblock
,
5097 argvec
[argnum
].locate
.offset
.constant
);
5099 = gen_rtx_MEM (save_mode
, memory_address (save_mode
, adr
));
5101 if (save_mode
== BLKmode
)
5103 argvec
[argnum
].save_area
5104 = assign_stack_temp (BLKmode
,
5105 argvec
[argnum
].locate
.size
.constant
5108 emit_block_move (validize_mem
5109 (copy_rtx (argvec
[argnum
].save_area
)),
5112 (argvec
[argnum
].locate
.size
.constant
,
5114 BLOCK_OP_CALL_PARM
);
5118 argvec
[argnum
].save_area
= gen_reg_rtx (save_mode
);
5120 emit_move_insn (argvec
[argnum
].save_area
, stack_area
);
5125 emit_push_insn (val
, mode
, NULL_TREE
, NULL_RTX
, parm_align
,
5126 partial
, reg
, 0, argblock
,
5128 (argvec
[argnum
].locate
.offset
.constant
, Pmode
)),
5129 reg_parm_stack_space
,
5130 ARGS_SIZE_RTX (argvec
[argnum
].locate
.alignment_pad
), false);
5132 /* Now mark the segment we just used. */
5133 if (ACCUMULATE_OUTGOING_ARGS
)
5134 mark_stack_region_used (lower_bound
, upper_bound
);
5138 /* Indicate argument access so that alias.c knows that these
5141 use
= plus_constant (Pmode
, argblock
,
5142 argvec
[argnum
].locate
.offset
.constant
);
5143 else if (have_push_fusage
)
5147 /* When arguments are pushed, trying to tell alias.c where
5148 exactly this argument is won't work, because the
5149 auto-increment causes confusion. So we merely indicate
5150 that we access something with a known mode somewhere on
5152 use
= gen_rtx_PLUS (Pmode
, stack_pointer_rtx
,
5153 gen_rtx_SCRATCH (Pmode
));
5154 have_push_fusage
= true;
5156 use
= gen_rtx_MEM (argvec
[argnum
].mode
, use
);
5157 use
= gen_rtx_USE (VOIDmode
, use
);
5158 call_fusage
= gen_rtx_EXPR_LIST (VOIDmode
, use
, call_fusage
);
5164 fun
= prepare_call_address (NULL
, fun
, NULL
, &call_fusage
, 0, 0);
5166 /* Now load any reg parms into their regs. */
5168 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
5169 are to be pushed. */
5170 for (count
= 0; count
< nargs
; count
++, argnum
--)
5172 machine_mode mode
= argvec
[argnum
].mode
;
5173 rtx val
= argvec
[argnum
].value
;
5174 rtx reg
= argvec
[argnum
].reg
;
5175 int partial
= argvec
[argnum
].partial
;
5177 /* Handle calls that pass values in multiple non-contiguous
5178 locations. The PA64 has examples of this for library calls. */
5179 if (reg
!= 0 && GET_CODE (reg
) == PARALLEL
)
5180 emit_group_load (reg
, val
, NULL_TREE
, GET_MODE_SIZE (mode
));
5181 else if (reg
!= 0 && partial
== 0)
5183 emit_move_insn (reg
, val
);
5184 #ifdef BLOCK_REG_PADDING
5185 poly_int64 size
= GET_MODE_SIZE (argvec
[argnum
].mode
);
5187 /* Copied from load_register_parameters. */
5189 /* Handle case where we have a value that needs shifting
5190 up to the msb. eg. a QImode value and we're padding
5191 upward on a BYTES_BIG_ENDIAN machine. */
5192 if (known_lt (size
, UNITS_PER_WORD
)
5193 && (argvec
[argnum
].locate
.where_pad
5194 == (BYTES_BIG_ENDIAN
? PAD_UPWARD
: PAD_DOWNWARD
)))
5197 poly_int64 shift
= (UNITS_PER_WORD
- size
) * BITS_PER_UNIT
;
5199 /* Assigning REG here rather than a temp makes CALL_FUSAGE
5200 report the whole reg as used. Strictly speaking, the
5201 call only uses SIZE bytes at the msb end, but it doesn't
5202 seem worth generating rtl to say that. */
5203 reg
= gen_rtx_REG (word_mode
, REGNO (reg
));
5204 x
= expand_shift (LSHIFT_EXPR
, word_mode
, reg
, shift
, reg
, 1);
5206 emit_move_insn (reg
, x
);
5214 /* Any regs containing parms remain in use through the call. */
5215 for (count
= 0; count
< nargs
; count
++)
5217 rtx reg
= argvec
[count
].reg
;
5218 if (reg
!= 0 && GET_CODE (reg
) == PARALLEL
)
5219 use_group_regs (&call_fusage
, reg
);
5222 int partial
= argvec
[count
].partial
;
5226 gcc_assert (partial
% UNITS_PER_WORD
== 0);
5227 nregs
= partial
/ UNITS_PER_WORD
;
5228 use_regs (&call_fusage
, REGNO (reg
), nregs
);
5231 use_reg (&call_fusage
, reg
);
5235 /* Pass the function the address in which to return a structure value. */
5236 if (mem_value
!= 0 && struct_value
!= 0 && ! pcc_struct_value
)
5238 emit_move_insn (struct_value
,
5240 force_operand (XEXP (mem_value
, 0),
5242 if (REG_P (struct_value
))
5243 use_reg (&call_fusage
, struct_value
);
5246 /* Don't allow popping to be deferred, since then
5247 cse'ing of library calls could delete a call and leave the pop. */
5249 valreg
= (mem_value
== 0 && outmode
!= VOIDmode
5250 ? hard_libcall_value (outmode
, orgfun
) : NULL_RTX
);
5252 /* Stack must be properly aligned now. */
5253 gcc_assert (multiple_p (stack_pointer_delta
,
5254 PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
));
5256 before_call
= get_last_insn ();
5258 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
5259 will set inhibit_defer_pop to that value. */
5260 /* The return type is needed to decide how many bytes the function pops.
5261 Signedness plays no role in that, so for simplicity, we pretend it's
5262 always signed. We also assume that the list of arguments passed has
5263 no impact, so we pretend it is unknown. */
5265 emit_call_1 (fun
, NULL
,
5266 get_identifier (XSTR (orgfun
, 0)),
5267 build_function_type (tfom
, NULL_TREE
),
5268 original_args_size
.constant
, args_size
.constant
,
5270 targetm
.calls
.function_arg (args_so_far
,
5271 VOIDmode
, void_type_node
, true),
5273 old_inhibit_defer_pop
+ 1, call_fusage
, flags
, args_so_far
);
5278 gcc_assert (GET_CODE (datum
) == SYMBOL_REF
);
5279 rtx_call_insn
*last
= last_call_insn ();
5280 add_reg_note (last
, REG_CALL_DECL
, datum
);
5283 /* Right-shift returned value if necessary. */
5284 if (!pcc_struct_value
5285 && TYPE_MODE (tfom
) != BLKmode
5286 && targetm
.calls
.return_in_msb (tfom
))
5288 shift_return_value (TYPE_MODE (tfom
), false, valreg
);
5289 valreg
= gen_rtx_REG (TYPE_MODE (tfom
), REGNO (valreg
));
5292 targetm
.calls
.end_call_args ();
5294 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
5295 that it should complain if nonvolatile values are live. For
5296 functions that cannot return, inform flow that control does not
5298 if (flags
& ECF_NORETURN
)
5300 /* The barrier note must be emitted
5301 immediately after the CALL_INSN. Some ports emit more than
5302 just a CALL_INSN above, so we must search for it here. */
5303 rtx_insn
*last
= get_last_insn ();
5304 while (!CALL_P (last
))
5306 last
= PREV_INSN (last
);
5307 /* There was no CALL_INSN? */
5308 gcc_assert (last
!= before_call
);
5311 emit_barrier_after (last
);
5314 /* Consider that "regular" libcalls, i.e. all of them except for LCT_THROW
5315 and LCT_RETURNS_TWICE, cannot perform non-local gotos. */
5316 if (flags
& ECF_NOTHROW
)
5318 rtx_insn
*last
= get_last_insn ();
5319 while (!CALL_P (last
))
5321 last
= PREV_INSN (last
);
5322 /* There was no CALL_INSN? */
5323 gcc_assert (last
!= before_call
);
5326 make_reg_eh_region_note_nothrow_nononlocal (last
);
5329 /* Now restore inhibit_defer_pop to its actual original value. */
5334 /* Copy the value to the right place. */
5335 if (outmode
!= VOIDmode
&& retval
)
5341 if (value
!= mem_value
)
5342 emit_move_insn (value
, mem_value
);
5344 else if (GET_CODE (valreg
) == PARALLEL
)
5347 value
= gen_reg_rtx (outmode
);
5348 emit_group_store (value
, valreg
, NULL_TREE
, GET_MODE_SIZE (outmode
));
5352 /* Convert to the proper mode if a promotion has been active. */
5353 if (GET_MODE (valreg
) != outmode
)
5355 int unsignedp
= TYPE_UNSIGNED (tfom
);
5357 gcc_assert (promote_function_mode (tfom
, outmode
, &unsignedp
,
5358 fndecl
? TREE_TYPE (fndecl
) : fntype
, 1)
5359 == GET_MODE (valreg
));
5360 valreg
= convert_modes (outmode
, GET_MODE (valreg
), valreg
, 0);
5364 emit_move_insn (value
, valreg
);
5370 if (ACCUMULATE_OUTGOING_ARGS
)
5372 #ifdef REG_PARM_STACK_SPACE
5374 restore_fixed_argument_area (save_area
, argblock
,
5375 high_to_save
, low_to_save
);
5378 /* If we saved any argument areas, restore them. */
5379 for (count
= 0; count
< nargs
; count
++)
5380 if (argvec
[count
].save_area
)
5382 machine_mode save_mode
= GET_MODE (argvec
[count
].save_area
);
5383 rtx adr
= plus_constant (Pmode
, argblock
,
5384 argvec
[count
].locate
.offset
.constant
);
5385 rtx stack_area
= gen_rtx_MEM (save_mode
,
5386 memory_address (save_mode
, adr
));
5388 if (save_mode
== BLKmode
)
5389 emit_block_move (stack_area
,
5391 (copy_rtx (argvec
[count
].save_area
)),
5393 (argvec
[count
].locate
.size
.constant
, Pmode
)),
5394 BLOCK_OP_CALL_PARM
);
5396 emit_move_insn (stack_area
, argvec
[count
].save_area
);
5399 highest_outgoing_arg_in_use
= initial_highest_arg_in_use
;
5400 stack_usage_map
= initial_stack_usage_map
;
5401 stack_usage_watermark
= initial_stack_usage_watermark
;
5404 free (stack_usage_map_buf
);
5411 /* Store a single argument for a function call
5412 into the register or memory area where it must be passed.
5413 *ARG describes the argument value and where to pass it.
5415 ARGBLOCK is the address of the stack-block for all the arguments,
5416 or 0 on a machine where arguments are pushed individually.
5418 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
5419 so must be careful about how the stack is used.
5421 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
5422 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
5423 that we need not worry about saving and restoring the stack.
5425 FNDECL is the declaration of the function we are calling.
5427 Return nonzero if this arg should cause sibcall failure,
5431 store_one_arg (struct arg_data
*arg
, rtx argblock
, int flags
,
5432 int variable_size ATTRIBUTE_UNUSED
, int reg_parm_stack_space
)
5434 tree pval
= arg
->tree_value
;
5437 poly_int64 used
= 0;
5438 poly_int64 lower_bound
= 0, upper_bound
= 0;
5439 int sibcall_failure
= 0;
5441 if (TREE_CODE (pval
) == ERROR_MARK
)
5444 /* Push a new temporary level for any temporaries we make for
5448 if (ACCUMULATE_OUTGOING_ARGS
&& !(flags
& ECF_SIBCALL
))
5450 /* If this is being stored into a pre-allocated, fixed-size, stack area,
5451 save any previous data at that location. */
5452 if (argblock
&& ! variable_size
&& arg
->stack
)
5454 if (ARGS_GROW_DOWNWARD
)
5456 /* stack_slot is negative, but we want to index stack_usage_map
5457 with positive values. */
5458 if (GET_CODE (XEXP (arg
->stack_slot
, 0)) == PLUS
)
5460 rtx offset
= XEXP (XEXP (arg
->stack_slot
, 0), 1);
5461 upper_bound
= -rtx_to_poly_int64 (offset
) + 1;
5466 lower_bound
= upper_bound
- arg
->locate
.size
.constant
;
5470 if (GET_CODE (XEXP (arg
->stack_slot
, 0)) == PLUS
)
5472 rtx offset
= XEXP (XEXP (arg
->stack_slot
, 0), 1);
5473 lower_bound
= rtx_to_poly_int64 (offset
);
5478 upper_bound
= lower_bound
+ arg
->locate
.size
.constant
;
5481 if (stack_region_maybe_used_p (lower_bound
, upper_bound
,
5482 reg_parm_stack_space
))
5484 /* We need to make a save area. */
5485 poly_uint64 size
= arg
->locate
.size
.constant
* BITS_PER_UNIT
;
5486 machine_mode save_mode
5487 = int_mode_for_size (size
, 1).else_blk ();
5488 rtx adr
= memory_address (save_mode
, XEXP (arg
->stack_slot
, 0));
5489 rtx stack_area
= gen_rtx_MEM (save_mode
, adr
);
5491 if (save_mode
== BLKmode
)
5494 = assign_temp (TREE_TYPE (arg
->tree_value
), 1, 1);
5495 preserve_temp_slots (arg
->save_area
);
5496 emit_block_move (validize_mem (copy_rtx (arg
->save_area
)),
5499 (arg
->locate
.size
.constant
, Pmode
)),
5500 BLOCK_OP_CALL_PARM
);
5504 arg
->save_area
= gen_reg_rtx (save_mode
);
5505 emit_move_insn (arg
->save_area
, stack_area
);
5511 /* If this isn't going to be placed on both the stack and in registers,
5512 set up the register and number of words. */
5513 if (! arg
->pass_on_stack
)
5515 if (flags
& ECF_SIBCALL
)
5516 reg
= arg
->tail_call_reg
;
5519 partial
= arg
->partial
;
5522 /* Being passed entirely in a register. We shouldn't be called in
5524 gcc_assert (reg
== 0 || partial
!= 0);
5526 /* If this arg needs special alignment, don't load the registers
5528 if (arg
->n_aligned_regs
!= 0)
5531 /* If this is being passed partially in a register, we can't evaluate
5532 it directly into its stack slot. Otherwise, we can. */
5533 if (arg
->value
== 0)
5535 /* stack_arg_under_construction is nonzero if a function argument is
5536 being evaluated directly into the outgoing argument list and
5537 expand_call must take special action to preserve the argument list
5538 if it is called recursively.
5540 For scalar function arguments stack_usage_map is sufficient to
5541 determine which stack slots must be saved and restored. Scalar
5542 arguments in general have pass_on_stack == 0.
5544 If this argument is initialized by a function which takes the
5545 address of the argument (a C++ constructor or a C function
5546 returning a BLKmode structure), then stack_usage_map is
5547 insufficient and expand_call must push the stack around the
5548 function call. Such arguments have pass_on_stack == 1.
5550 Note that it is always safe to set stack_arg_under_construction,
5551 but this generates suboptimal code if set when not needed. */
5553 if (arg
->pass_on_stack
)
5554 stack_arg_under_construction
++;
5556 arg
->value
= expand_expr (pval
,
5558 || TYPE_MODE (TREE_TYPE (pval
)) != arg
->mode
)
5559 ? NULL_RTX
: arg
->stack
,
5560 VOIDmode
, EXPAND_STACK_PARM
);
5562 /* If we are promoting object (or for any other reason) the mode
5563 doesn't agree, convert the mode. */
5565 if (arg
->mode
!= TYPE_MODE (TREE_TYPE (pval
)))
5566 arg
->value
= convert_modes (arg
->mode
, TYPE_MODE (TREE_TYPE (pval
)),
5567 arg
->value
, arg
->unsignedp
);
5569 if (arg
->pass_on_stack
)
5570 stack_arg_under_construction
--;
5573 /* Check for overlap with already clobbered argument area. */
5574 if ((flags
& ECF_SIBCALL
)
5575 && MEM_P (arg
->value
)
5576 && mem_might_overlap_already_clobbered_arg_p (XEXP (arg
->value
, 0),
5577 arg
->locate
.size
.constant
))
5578 sibcall_failure
= 1;
5580 /* Don't allow anything left on stack from computation
5581 of argument to alloca. */
5582 if (flags
& ECF_MAY_BE_ALLOCA
)
5583 do_pending_stack_adjust ();
5585 if (arg
->value
== arg
->stack
)
5586 /* If the value is already in the stack slot, we are done. */
5588 else if (arg
->mode
!= BLKmode
)
5590 unsigned int parm_align
;
5592 /* Argument is a scalar, not entirely passed in registers.
5593 (If part is passed in registers, arg->partial says how much
5594 and emit_push_insn will take care of putting it there.)
5596 Push it, and if its size is less than the
5597 amount of space allocated to it,
5598 also bump stack pointer by the additional space.
5599 Note that in C the default argument promotions
5600 will prevent such mismatches. */
5602 poly_int64 size
= (TYPE_EMPTY_P (TREE_TYPE (pval
))
5603 ? 0 : GET_MODE_SIZE (arg
->mode
));
5605 /* Compute how much space the push instruction will push.
5606 On many machines, pushing a byte will advance the stack
5607 pointer by a halfword. */
5608 #ifdef PUSH_ROUNDING
5609 size
= PUSH_ROUNDING (size
);
5613 /* Compute how much space the argument should get:
5614 round up to a multiple of the alignment for arguments. */
5615 if (targetm
.calls
.function_arg_padding (arg
->mode
, TREE_TYPE (pval
))
5617 /* At the moment we don't (need to) support ABIs for which the
5618 padding isn't known at compile time. In principle it should
5619 be easy to add though. */
5620 used
= force_align_up (size
, PARM_BOUNDARY
/ BITS_PER_UNIT
);
5622 /* Compute the alignment of the pushed argument. */
5623 parm_align
= arg
->locate
.boundary
;
5624 if (targetm
.calls
.function_arg_padding (arg
->mode
, TREE_TYPE (pval
))
5627 poly_int64 pad
= used
- size
;
5628 unsigned int pad_align
= known_alignment (pad
) * BITS_PER_UNIT
;
5630 parm_align
= MIN (parm_align
, pad_align
);
5633 /* This isn't already where we want it on the stack, so put it there.
5634 This can either be done with push or copy insns. */
5635 if (maybe_ne (used
, 0)
5636 && !emit_push_insn (arg
->value
, arg
->mode
, TREE_TYPE (pval
),
5637 NULL_RTX
, parm_align
, partial
, reg
, used
- size
,
5638 argblock
, ARGS_SIZE_RTX (arg
->locate
.offset
),
5639 reg_parm_stack_space
,
5640 ARGS_SIZE_RTX (arg
->locate
.alignment_pad
), true))
5641 sibcall_failure
= 1;
5643 /* Unless this is a partially-in-register argument, the argument is now
5646 arg
->value
= arg
->stack
;
5650 /* BLKmode, at least partly to be pushed. */
5652 unsigned int parm_align
;
5656 /* Pushing a nonscalar.
5657 If part is passed in registers, PARTIAL says how much
5658 and emit_push_insn will take care of putting it there. */
5660 /* Round its size up to a multiple
5661 of the allocation unit for arguments. */
5663 if (arg
->locate
.size
.var
!= 0)
5666 size_rtx
= ARGS_SIZE_RTX (arg
->locate
.size
);
5670 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
5671 for BLKmode is careful to avoid it. */
5672 excess
= (arg
->locate
.size
.constant
5673 - arg_int_size_in_bytes (TREE_TYPE (pval
))
5675 size_rtx
= expand_expr (arg_size_in_bytes (TREE_TYPE (pval
)),
5676 NULL_RTX
, TYPE_MODE (sizetype
),
5680 parm_align
= arg
->locate
.boundary
;
5682 /* When an argument is padded down, the block is aligned to
5683 PARM_BOUNDARY, but the actual argument isn't. */
5684 if (targetm
.calls
.function_arg_padding (arg
->mode
, TREE_TYPE (pval
))
5687 if (arg
->locate
.size
.var
)
5688 parm_align
= BITS_PER_UNIT
;
5691 unsigned int excess_align
5692 = known_alignment (excess
) * BITS_PER_UNIT
;
5693 if (excess_align
!= 0)
5694 parm_align
= MIN (parm_align
, excess_align
);
5698 if ((flags
& ECF_SIBCALL
) && MEM_P (arg
->value
))
5700 /* emit_push_insn might not work properly if arg->value and
5701 argblock + arg->locate.offset areas overlap. */
5705 if (strip_offset (XEXP (x
, 0), &i
)
5706 == crtl
->args
.internal_arg_pointer
)
5708 /* arg.locate doesn't contain the pretend_args_size offset,
5709 it's part of argblock. Ensure we don't count it in I. */
5710 if (STACK_GROWS_DOWNWARD
)
5711 i
-= crtl
->args
.pretend_args_size
;
5713 i
+= crtl
->args
.pretend_args_size
;
5715 /* expand_call should ensure this. */
5716 gcc_assert (!arg
->locate
.offset
.var
5717 && arg
->locate
.size
.var
== 0);
5718 poly_int64 size_val
= rtx_to_poly_int64 (size_rtx
);
5720 if (known_eq (arg
->locate
.offset
.constant
, i
))
5722 /* Even though they appear to be at the same location,
5723 if part of the outgoing argument is in registers,
5724 they aren't really at the same location. Check for
5725 this by making sure that the incoming size is the
5726 same as the outgoing size. */
5727 if (maybe_ne (arg
->locate
.size
.constant
, size_val
))
5728 sibcall_failure
= 1;
5730 else if (maybe_in_range_p (arg
->locate
.offset
.constant
,
5732 sibcall_failure
= 1;
5733 /* Use arg->locate.size.constant instead of size_rtx
5734 because we only care about the part of the argument
5736 else if (maybe_in_range_p (i
, arg
->locate
.offset
.constant
,
5737 arg
->locate
.size
.constant
))
5738 sibcall_failure
= 1;
5742 if (!CONST_INT_P (size_rtx
) || INTVAL (size_rtx
) != 0)
5743 emit_push_insn (arg
->value
, arg
->mode
, TREE_TYPE (pval
), size_rtx
,
5744 parm_align
, partial
, reg
, excess
, argblock
,
5745 ARGS_SIZE_RTX (arg
->locate
.offset
),
5746 reg_parm_stack_space
,
5747 ARGS_SIZE_RTX (arg
->locate
.alignment_pad
), false);
5749 /* Unless this is a partially-in-register argument, the argument is now
5752 ??? Unlike the case above, in which we want the actual
5753 address of the data, so that we can load it directly into a
5754 register, here we want the address of the stack slot, so that
5755 it's properly aligned for word-by-word copying or something
5756 like that. It's not clear that this is always correct. */
5758 arg
->value
= arg
->stack_slot
;
5761 if (arg
->reg
&& GET_CODE (arg
->reg
) == PARALLEL
)
5763 tree type
= TREE_TYPE (arg
->tree_value
);
5765 = emit_group_load_into_temps (arg
->reg
, arg
->value
, type
,
5766 int_size_in_bytes (type
));
5769 /* Mark all slots this store used. */
5770 if (ACCUMULATE_OUTGOING_ARGS
&& !(flags
& ECF_SIBCALL
)
5771 && argblock
&& ! variable_size
&& arg
->stack
)
5772 mark_stack_region_used (lower_bound
, upper_bound
);
5774 /* Once we have pushed something, pops can't safely
5775 be deferred during the rest of the arguments. */
5778 /* Free any temporary slots made in processing this argument. */
5781 return sibcall_failure
;
5784 /* Nonzero if we do not know how to pass TYPE solely in registers. */
5787 must_pass_in_stack_var_size (machine_mode mode ATTRIBUTE_UNUSED
,
5793 /* If the type has variable size... */
5794 if (TREE_CODE (TYPE_SIZE (type
)) != INTEGER_CST
)
5797 /* If the type is marked as addressable (it is required
5798 to be constructed into the stack)... */
5799 if (TREE_ADDRESSABLE (type
))
5805 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
5806 takes trailing padding of a structure into account. */
5807 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
5810 must_pass_in_stack_var_size_or_pad (machine_mode mode
, const_tree type
)
5815 /* If the type has variable size... */
5816 if (TREE_CODE (TYPE_SIZE (type
)) != INTEGER_CST
)
5819 /* If the type is marked as addressable (it is required
5820 to be constructed into the stack)... */
5821 if (TREE_ADDRESSABLE (type
))
5824 if (TYPE_EMPTY_P (type
))
5827 /* If the padding and mode of the type is such that a copy into
5828 a register would put it into the wrong part of the register. */
5830 && int_size_in_bytes (type
) % (PARM_BOUNDARY
/ BITS_PER_UNIT
)
5831 && (targetm
.calls
.function_arg_padding (mode
, type
)
5832 == (BYTES_BIG_ENDIAN
? PAD_UPWARD
: PAD_DOWNWARD
)))
5838 /* Tell the garbage collector about GTY markers in this source file. */
5839 #include "gt-calls.h"