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Add a apply_pass_by_reference_rules helper
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1 /* Convert function calls to rtl insns, for GNU C compiler.
2 Copyright (C) 1989-2019 Free Software Foundation, Inc.
3
4 This file is part of GCC.
5
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
9 version.
10
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
14 for more details.
15
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/>. */
19
20 #include "config.h"
21 #include "system.h"
22 #include "coretypes.h"
23 #include "backend.h"
24 #include "target.h"
25 #include "rtl.h"
26 #include "tree.h"
27 #include "gimple.h"
28 #include "predict.h"
29 #include "memmodel.h"
30 #include "tm_p.h"
31 #include "stringpool.h"
32 #include "expmed.h"
33 #include "optabs.h"
34 #include "emit-rtl.h"
35 #include "cgraph.h"
36 #include "diagnostic-core.h"
37 #include "fold-const.h"
38 #include "stor-layout.h"
39 #include "varasm.h"
40 #include "internal-fn.h"
41 #include "dojump.h"
42 #include "explow.h"
43 #include "calls.h"
44 #include "expr.h"
45 #include "output.h"
46 #include "langhooks.h"
47 #include "except.h"
48 #include "dbgcnt.h"
49 #include "rtl-iter.h"
50 #include "tree-vrp.h"
51 #include "tree-ssanames.h"
52 #include "tree-ssa-strlen.h"
53 #include "intl.h"
54 #include "stringpool.h"
55 #include "attribs.h"
56 #include "builtins.h"
57 #include "gimple-fold.h"
58
59 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
60 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
61
62 /* Data structure and subroutines used within expand_call. */
63
64 struct arg_data
65 {
66 /* Tree node for this argument. */
67 tree tree_value;
68 /* Mode for value; TYPE_MODE unless promoted. */
69 machine_mode mode;
70 /* Current RTL value for argument, or 0 if it isn't precomputed. */
71 rtx value;
72 /* Initially-compute RTL value for argument; only for const functions. */
73 rtx initial_value;
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
76 registers. */
77 rtx reg;
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
80 register windows. */
81 rtx tail_call_reg;
82 /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct
83 form for emit_group_move. */
84 rtx parallel_value;
85 /* If REG was promoted from the actual mode of the argument expression,
86 indicates whether the promotion is sign- or zero-extended. */
87 int unsignedp;
88 /* Number of bytes to put in registers. 0 means put the whole arg
89 in registers. Also 0 if not passed in registers. */
90 int partial;
91 /* Nonzero if argument must be passed on stack.
92 Note that some arguments may be passed on the stack
93 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
94 pass_on_stack identifies arguments that *cannot* go in registers. */
95 int pass_on_stack;
96 /* Some fields packaged up for locate_and_pad_parm. */
97 struct locate_and_pad_arg_data locate;
98 /* Location on the stack at which parameter should be stored. The store
99 has already been done if STACK == VALUE. */
100 rtx stack;
101 /* Location on the stack of the start of this argument slot. This can
102 differ from STACK if this arg pads downward. This location is known
103 to be aligned to TARGET_FUNCTION_ARG_BOUNDARY. */
104 rtx stack_slot;
105 /* Place that this stack area has been saved, if needed. */
106 rtx save_area;
107 /* If an argument's alignment does not permit direct copying into registers,
108 copy in smaller-sized pieces into pseudos. These are stored in a
109 block pointed to by this field. The next field says how many
110 word-sized pseudos we made. */
111 rtx *aligned_regs;
112 int n_aligned_regs;
113 };
114
115 /* A vector of one char per byte of stack space. A byte if nonzero if
116 the corresponding stack location has been used.
117 This vector is used to prevent a function call within an argument from
118 clobbering any stack already set up. */
119 static char *stack_usage_map;
120
121 /* Size of STACK_USAGE_MAP. */
122 static unsigned int highest_outgoing_arg_in_use;
123
124 /* Assume that any stack location at this byte index is used,
125 without checking the contents of stack_usage_map. */
126 static unsigned HOST_WIDE_INT stack_usage_watermark = HOST_WIDE_INT_M1U;
127
128 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
129 stack location's tail call argument has been already stored into the stack.
130 This bitmap is used to prevent sibling call optimization if function tries
131 to use parent's incoming argument slots when they have been already
132 overwritten with tail call arguments. */
133 static sbitmap stored_args_map;
134
135 /* Assume that any virtual-incoming location at this byte index has been
136 stored, without checking the contents of stored_args_map. */
137 static unsigned HOST_WIDE_INT stored_args_watermark;
138
139 /* stack_arg_under_construction is nonzero when an argument may be
140 initialized with a constructor call (including a C function that
141 returns a BLKmode struct) and expand_call must take special action
142 to make sure the object being constructed does not overlap the
143 argument list for the constructor call. */
144 static int stack_arg_under_construction;
145
146 static void precompute_register_parameters (int, struct arg_data *, int *);
147 static int store_one_arg (struct arg_data *, rtx, int, int, int);
148 static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
149 static int finalize_must_preallocate (int, int, struct arg_data *,
150 struct args_size *);
151 static void precompute_arguments (int, struct arg_data *);
152 static void compute_argument_addresses (struct arg_data *, rtx, int);
153 static rtx rtx_for_function_call (tree, tree);
154 static void load_register_parameters (struct arg_data *, int, rtx *, int,
155 int, int *);
156 static int special_function_p (const_tree, int);
157 static int check_sibcall_argument_overlap_1 (rtx);
158 static int check_sibcall_argument_overlap (rtx_insn *, struct arg_data *, int);
159
160 static tree split_complex_types (tree);
161
162 #ifdef REG_PARM_STACK_SPACE
163 static rtx save_fixed_argument_area (int, rtx, int *, int *);
164 static void restore_fixed_argument_area (rtx, rtx, int, int);
165 #endif
166 \f
167 /* Return true if bytes [LOWER_BOUND, UPPER_BOUND) of the outgoing
168 stack region might already be in use. */
169
170 static bool
171 stack_region_maybe_used_p (poly_uint64 lower_bound, poly_uint64 upper_bound,
172 unsigned int reg_parm_stack_space)
173 {
174 unsigned HOST_WIDE_INT const_lower, const_upper;
175 const_lower = constant_lower_bound (lower_bound);
176 if (!upper_bound.is_constant (&const_upper))
177 const_upper = HOST_WIDE_INT_M1U;
178
179 if (const_upper > stack_usage_watermark)
180 return true;
181
182 /* Don't worry about things in the fixed argument area;
183 it has already been saved. */
184 const_lower = MAX (const_lower, reg_parm_stack_space);
185 const_upper = MIN (const_upper, highest_outgoing_arg_in_use);
186 for (unsigned HOST_WIDE_INT i = const_lower; i < const_upper; ++i)
187 if (stack_usage_map[i])
188 return true;
189 return false;
190 }
191
192 /* Record that bytes [LOWER_BOUND, UPPER_BOUND) of the outgoing
193 stack region are now in use. */
194
195 static void
196 mark_stack_region_used (poly_uint64 lower_bound, poly_uint64 upper_bound)
197 {
198 unsigned HOST_WIDE_INT const_lower, const_upper;
199 const_lower = constant_lower_bound (lower_bound);
200 if (upper_bound.is_constant (&const_upper))
201 for (unsigned HOST_WIDE_INT i = const_lower; i < const_upper; ++i)
202 stack_usage_map[i] = 1;
203 else
204 stack_usage_watermark = MIN (stack_usage_watermark, const_lower);
205 }
206
207 /* Force FUNEXP into a form suitable for the address of a CALL,
208 and return that as an rtx. Also load the static chain register
209 if FNDECL is a nested function.
210
211 CALL_FUSAGE points to a variable holding the prospective
212 CALL_INSN_FUNCTION_USAGE information. */
213
214 rtx
215 prepare_call_address (tree fndecl_or_type, rtx funexp, rtx static_chain_value,
216 rtx *call_fusage, int reg_parm_seen, int flags)
217 {
218 /* Make a valid memory address and copy constants through pseudo-regs,
219 but not for a constant address if -fno-function-cse. */
220 if (GET_CODE (funexp) != SYMBOL_REF)
221 {
222 /* If it's an indirect call by descriptor, generate code to perform
223 runtime identification of the pointer and load the descriptor. */
224 if ((flags & ECF_BY_DESCRIPTOR) && !flag_trampolines)
225 {
226 const int bit_val = targetm.calls.custom_function_descriptors;
227 rtx call_lab = gen_label_rtx ();
228
229 gcc_assert (fndecl_or_type && TYPE_P (fndecl_or_type));
230 fndecl_or_type
231 = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL, NULL_TREE,
232 fndecl_or_type);
233 DECL_STATIC_CHAIN (fndecl_or_type) = 1;
234 rtx chain = targetm.calls.static_chain (fndecl_or_type, false);
235
236 if (GET_MODE (funexp) != Pmode)
237 funexp = convert_memory_address (Pmode, funexp);
238
239 /* Avoid long live ranges around function calls. */
240 funexp = copy_to_mode_reg (Pmode, funexp);
241
242 if (REG_P (chain))
243 emit_insn (gen_rtx_CLOBBER (VOIDmode, chain));
244
245 /* Emit the runtime identification pattern. */
246 rtx mask = gen_rtx_AND (Pmode, funexp, GEN_INT (bit_val));
247 emit_cmp_and_jump_insns (mask, const0_rtx, EQ, NULL_RTX, Pmode, 1,
248 call_lab);
249
250 /* Statically predict the branch to very likely taken. */
251 rtx_insn *insn = get_last_insn ();
252 if (JUMP_P (insn))
253 predict_insn_def (insn, PRED_BUILTIN_EXPECT, TAKEN);
254
255 /* Load the descriptor. */
256 rtx mem = gen_rtx_MEM (ptr_mode,
257 plus_constant (Pmode, funexp, - bit_val));
258 MEM_NOTRAP_P (mem) = 1;
259 mem = convert_memory_address (Pmode, mem);
260 emit_move_insn (chain, mem);
261
262 mem = gen_rtx_MEM (ptr_mode,
263 plus_constant (Pmode, funexp,
264 POINTER_SIZE / BITS_PER_UNIT
265 - bit_val));
266 MEM_NOTRAP_P (mem) = 1;
267 mem = convert_memory_address (Pmode, mem);
268 emit_move_insn (funexp, mem);
269
270 emit_label (call_lab);
271
272 if (REG_P (chain))
273 {
274 use_reg (call_fusage, chain);
275 STATIC_CHAIN_REG_P (chain) = 1;
276 }
277
278 /* Make sure we're not going to be overwritten below. */
279 gcc_assert (!static_chain_value);
280 }
281
282 /* If we are using registers for parameters, force the
283 function address into a register now. */
284 funexp = ((reg_parm_seen
285 && targetm.small_register_classes_for_mode_p (FUNCTION_MODE))
286 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
287 : memory_address (FUNCTION_MODE, funexp));
288 }
289 else
290 {
291 /* funexp could be a SYMBOL_REF represents a function pointer which is
292 of ptr_mode. In this case, it should be converted into address mode
293 to be a valid address for memory rtx pattern. See PR 64971. */
294 if (GET_MODE (funexp) != Pmode)
295 funexp = convert_memory_address (Pmode, funexp);
296
297 if (!(flags & ECF_SIBCALL))
298 {
299 if (!NO_FUNCTION_CSE && optimize && ! flag_no_function_cse)
300 funexp = force_reg (Pmode, funexp);
301 }
302 }
303
304 if (static_chain_value != 0
305 && (TREE_CODE (fndecl_or_type) != FUNCTION_DECL
306 || DECL_STATIC_CHAIN (fndecl_or_type)))
307 {
308 rtx chain;
309
310 chain = targetm.calls.static_chain (fndecl_or_type, false);
311 static_chain_value = convert_memory_address (Pmode, static_chain_value);
312
313 emit_move_insn (chain, static_chain_value);
314 if (REG_P (chain))
315 {
316 use_reg (call_fusage, chain);
317 STATIC_CHAIN_REG_P (chain) = 1;
318 }
319 }
320
321 return funexp;
322 }
323
324 /* Generate instructions to call function FUNEXP,
325 and optionally pop the results.
326 The CALL_INSN is the first insn generated.
327
328 FNDECL is the declaration node of the function. This is given to the
329 hook TARGET_RETURN_POPS_ARGS to determine whether this function pops
330 its own args.
331
332 FUNTYPE is the data type of the function. This is given to the hook
333 TARGET_RETURN_POPS_ARGS to determine whether this function pops its
334 own args. We used to allow an identifier for library functions, but
335 that doesn't work when the return type is an aggregate type and the
336 calling convention says that the pointer to this aggregate is to be
337 popped by the callee.
338
339 STACK_SIZE is the number of bytes of arguments on the stack,
340 ROUNDED_STACK_SIZE is that number rounded up to
341 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
342 both to put into the call insn and to generate explicit popping
343 code if necessary.
344
345 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
346 It is zero if this call doesn't want a structure value.
347
348 NEXT_ARG_REG is the rtx that results from executing
349 targetm.calls.function_arg (&args_so_far,
350 function_arg_info::end_marker ());
351 just after all the args have had their registers assigned.
352 This could be whatever you like, but normally it is the first
353 arg-register beyond those used for args in this call,
354 or 0 if all the arg-registers are used in this call.
355 It is passed on to `gen_call' so you can put this info in the call insn.
356
357 VALREG is a hard register in which a value is returned,
358 or 0 if the call does not return a value.
359
360 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
361 the args to this call were processed.
362 We restore `inhibit_defer_pop' to that value.
363
364 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
365 denote registers used by the called function. */
366
367 static void
368 emit_call_1 (rtx funexp, tree fntree ATTRIBUTE_UNUSED, tree fndecl ATTRIBUTE_UNUSED,
369 tree funtype ATTRIBUTE_UNUSED,
370 poly_int64 stack_size ATTRIBUTE_UNUSED,
371 poly_int64 rounded_stack_size,
372 poly_int64 struct_value_size ATTRIBUTE_UNUSED,
373 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
374 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
375 cumulative_args_t args_so_far ATTRIBUTE_UNUSED)
376 {
377 rtx rounded_stack_size_rtx = gen_int_mode (rounded_stack_size, Pmode);
378 rtx call, funmem, pat;
379 int already_popped = 0;
380 poly_int64 n_popped = 0;
381
382 /* Sibling call patterns never pop arguments (no sibcall(_value)_pop
383 patterns exist). Any popping that the callee does on return will
384 be from our caller's frame rather than ours. */
385 if (!(ecf_flags & ECF_SIBCALL))
386 {
387 n_popped += targetm.calls.return_pops_args (fndecl, funtype, stack_size);
388
389 #ifdef CALL_POPS_ARGS
390 n_popped += CALL_POPS_ARGS (*get_cumulative_args (args_so_far));
391 #endif
392 }
393
394 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
395 and we don't want to load it into a register as an optimization,
396 because prepare_call_address already did it if it should be done. */
397 if (GET_CODE (funexp) != SYMBOL_REF)
398 funexp = memory_address (FUNCTION_MODE, funexp);
399
400 funmem = gen_rtx_MEM (FUNCTION_MODE, funexp);
401 if (fndecl && TREE_CODE (fndecl) == FUNCTION_DECL)
402 {
403 tree t = fndecl;
404
405 /* Although a built-in FUNCTION_DECL and its non-__builtin
406 counterpart compare equal and get a shared mem_attrs, they
407 produce different dump output in compare-debug compilations,
408 if an entry gets garbage collected in one compilation, then
409 adds a different (but equivalent) entry, while the other
410 doesn't run the garbage collector at the same spot and then
411 shares the mem_attr with the equivalent entry. */
412 if (DECL_BUILT_IN_CLASS (t) == BUILT_IN_NORMAL)
413 {
414 tree t2 = builtin_decl_explicit (DECL_FUNCTION_CODE (t));
415 if (t2)
416 t = t2;
417 }
418
419 set_mem_expr (funmem, t);
420 }
421 else if (fntree)
422 set_mem_expr (funmem, build_simple_mem_ref (CALL_EXPR_FN (fntree)));
423
424 if (ecf_flags & ECF_SIBCALL)
425 {
426 if (valreg)
427 pat = targetm.gen_sibcall_value (valreg, funmem,
428 rounded_stack_size_rtx,
429 next_arg_reg, NULL_RTX);
430 else
431 pat = targetm.gen_sibcall (funmem, rounded_stack_size_rtx,
432 next_arg_reg,
433 gen_int_mode (struct_value_size, Pmode));
434 }
435 /* If the target has "call" or "call_value" insns, then prefer them
436 if no arguments are actually popped. If the target does not have
437 "call" or "call_value" insns, then we must use the popping versions
438 even if the call has no arguments to pop. */
439 else if (maybe_ne (n_popped, 0)
440 || !(valreg
441 ? targetm.have_call_value ()
442 : targetm.have_call ()))
443 {
444 rtx n_pop = gen_int_mode (n_popped, Pmode);
445
446 /* If this subroutine pops its own args, record that in the call insn
447 if possible, for the sake of frame pointer elimination. */
448
449 if (valreg)
450 pat = targetm.gen_call_value_pop (valreg, funmem,
451 rounded_stack_size_rtx,
452 next_arg_reg, n_pop);
453 else
454 pat = targetm.gen_call_pop (funmem, rounded_stack_size_rtx,
455 next_arg_reg, n_pop);
456
457 already_popped = 1;
458 }
459 else
460 {
461 if (valreg)
462 pat = targetm.gen_call_value (valreg, funmem, rounded_stack_size_rtx,
463 next_arg_reg, NULL_RTX);
464 else
465 pat = targetm.gen_call (funmem, rounded_stack_size_rtx, next_arg_reg,
466 gen_int_mode (struct_value_size, Pmode));
467 }
468 emit_insn (pat);
469
470 /* Find the call we just emitted. */
471 rtx_call_insn *call_insn = last_call_insn ();
472
473 /* Some target create a fresh MEM instead of reusing the one provided
474 above. Set its MEM_EXPR. */
475 call = get_call_rtx_from (call_insn);
476 if (call
477 && MEM_EXPR (XEXP (call, 0)) == NULL_TREE
478 && MEM_EXPR (funmem) != NULL_TREE)
479 set_mem_expr (XEXP (call, 0), MEM_EXPR (funmem));
480
481 /* Put the register usage information there. */
482 add_function_usage_to (call_insn, call_fusage);
483
484 /* If this is a const call, then set the insn's unchanging bit. */
485 if (ecf_flags & ECF_CONST)
486 RTL_CONST_CALL_P (call_insn) = 1;
487
488 /* If this is a pure call, then set the insn's unchanging bit. */
489 if (ecf_flags & ECF_PURE)
490 RTL_PURE_CALL_P (call_insn) = 1;
491
492 /* If this is a const call, then set the insn's unchanging bit. */
493 if (ecf_flags & ECF_LOOPING_CONST_OR_PURE)
494 RTL_LOOPING_CONST_OR_PURE_CALL_P (call_insn) = 1;
495
496 /* Create a nothrow REG_EH_REGION note, if needed. */
497 make_reg_eh_region_note (call_insn, ecf_flags, 0);
498
499 if (ecf_flags & ECF_NORETURN)
500 add_reg_note (call_insn, REG_NORETURN, const0_rtx);
501
502 if (ecf_flags & ECF_RETURNS_TWICE)
503 {
504 add_reg_note (call_insn, REG_SETJMP, const0_rtx);
505 cfun->calls_setjmp = 1;
506 }
507
508 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
509
510 /* Restore this now, so that we do defer pops for this call's args
511 if the context of the call as a whole permits. */
512 inhibit_defer_pop = old_inhibit_defer_pop;
513
514 if (maybe_ne (n_popped, 0))
515 {
516 if (!already_popped)
517 CALL_INSN_FUNCTION_USAGE (call_insn)
518 = gen_rtx_EXPR_LIST (VOIDmode,
519 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
520 CALL_INSN_FUNCTION_USAGE (call_insn));
521 rounded_stack_size -= n_popped;
522 rounded_stack_size_rtx = gen_int_mode (rounded_stack_size, Pmode);
523 stack_pointer_delta -= n_popped;
524
525 add_args_size_note (call_insn, stack_pointer_delta);
526
527 /* If popup is needed, stack realign must use DRAP */
528 if (SUPPORTS_STACK_ALIGNMENT)
529 crtl->need_drap = true;
530 }
531 /* For noreturn calls when not accumulating outgoing args force
532 REG_ARGS_SIZE note to prevent crossjumping of calls with different
533 args sizes. */
534 else if (!ACCUMULATE_OUTGOING_ARGS && (ecf_flags & ECF_NORETURN) != 0)
535 add_args_size_note (call_insn, stack_pointer_delta);
536
537 if (!ACCUMULATE_OUTGOING_ARGS)
538 {
539 /* If returning from the subroutine does not automatically pop the args,
540 we need an instruction to pop them sooner or later.
541 Perhaps do it now; perhaps just record how much space to pop later.
542
543 If returning from the subroutine does pop the args, indicate that the
544 stack pointer will be changed. */
545
546 if (maybe_ne (rounded_stack_size, 0))
547 {
548 if (ecf_flags & ECF_NORETURN)
549 /* Just pretend we did the pop. */
550 stack_pointer_delta -= rounded_stack_size;
551 else if (flag_defer_pop && inhibit_defer_pop == 0
552 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
553 pending_stack_adjust += rounded_stack_size;
554 else
555 adjust_stack (rounded_stack_size_rtx);
556 }
557 }
558 /* When we accumulate outgoing args, we must avoid any stack manipulations.
559 Restore the stack pointer to its original value now. Usually
560 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
561 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
562 popping variants of functions exist as well.
563
564 ??? We may optimize similar to defer_pop above, but it is
565 probably not worthwhile.
566
567 ??? It will be worthwhile to enable combine_stack_adjustments even for
568 such machines. */
569 else if (maybe_ne (n_popped, 0))
570 anti_adjust_stack (gen_int_mode (n_popped, Pmode));
571 }
572
573 /* Determine if the function identified by FNDECL is one with
574 special properties we wish to know about. Modify FLAGS accordingly.
575
576 For example, if the function might return more than one time (setjmp), then
577 set ECF_RETURNS_TWICE.
578
579 Set ECF_MAY_BE_ALLOCA for any memory allocation function that might allocate
580 space from the stack such as alloca. */
581
582 static int
583 special_function_p (const_tree fndecl, int flags)
584 {
585 tree name_decl = DECL_NAME (fndecl);
586
587 if (fndecl && name_decl
588 && IDENTIFIER_LENGTH (name_decl) <= 11
589 /* Exclude functions not at the file scope, or not `extern',
590 since they are not the magic functions we would otherwise
591 think they are.
592 FIXME: this should be handled with attributes, not with this
593 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
594 because you can declare fork() inside a function if you
595 wish. */
596 && (DECL_CONTEXT (fndecl) == NULL_TREE
597 || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
598 && TREE_PUBLIC (fndecl))
599 {
600 const char *name = IDENTIFIER_POINTER (name_decl);
601 const char *tname = name;
602
603 /* We assume that alloca will always be called by name. It
604 makes no sense to pass it as a pointer-to-function to
605 anything that does not understand its behavior. */
606 if (IDENTIFIER_LENGTH (name_decl) == 6
607 && name[0] == 'a'
608 && ! strcmp (name, "alloca"))
609 flags |= ECF_MAY_BE_ALLOCA;
610
611 /* Disregard prefix _ or __. */
612 if (name[0] == '_')
613 {
614 if (name[1] == '_')
615 tname += 2;
616 else
617 tname += 1;
618 }
619
620 /* ECF_RETURNS_TWICE is safe even for -ffreestanding. */
621 if (! strcmp (tname, "setjmp")
622 || ! strcmp (tname, "sigsetjmp")
623 || ! strcmp (name, "savectx")
624 || ! strcmp (name, "vfork")
625 || ! strcmp (name, "getcontext"))
626 flags |= ECF_RETURNS_TWICE;
627 }
628
629 if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
630 && ALLOCA_FUNCTION_CODE_P (DECL_FUNCTION_CODE (fndecl)))
631 flags |= ECF_MAY_BE_ALLOCA;
632
633 return flags;
634 }
635
636 /* Similar to special_function_p; return a set of ERF_ flags for the
637 function FNDECL. */
638 static int
639 decl_return_flags (tree fndecl)
640 {
641 tree attr;
642 tree type = TREE_TYPE (fndecl);
643 if (!type)
644 return 0;
645
646 attr = lookup_attribute ("fn spec", TYPE_ATTRIBUTES (type));
647 if (!attr)
648 return 0;
649
650 attr = TREE_VALUE (TREE_VALUE (attr));
651 if (!attr || TREE_STRING_LENGTH (attr) < 1)
652 return 0;
653
654 switch (TREE_STRING_POINTER (attr)[0])
655 {
656 case '1':
657 case '2':
658 case '3':
659 case '4':
660 return ERF_RETURNS_ARG | (TREE_STRING_POINTER (attr)[0] - '1');
661
662 case 'm':
663 return ERF_NOALIAS;
664
665 case '.':
666 default:
667 return 0;
668 }
669 }
670
671 /* Return nonzero when FNDECL represents a call to setjmp. */
672
673 int
674 setjmp_call_p (const_tree fndecl)
675 {
676 if (DECL_IS_RETURNS_TWICE (fndecl))
677 return ECF_RETURNS_TWICE;
678 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
679 }
680
681
682 /* Return true if STMT may be an alloca call. */
683
684 bool
685 gimple_maybe_alloca_call_p (const gimple *stmt)
686 {
687 tree fndecl;
688
689 if (!is_gimple_call (stmt))
690 return false;
691
692 fndecl = gimple_call_fndecl (stmt);
693 if (fndecl && (special_function_p (fndecl, 0) & ECF_MAY_BE_ALLOCA))
694 return true;
695
696 return false;
697 }
698
699 /* Return true if STMT is a builtin alloca call. */
700
701 bool
702 gimple_alloca_call_p (const gimple *stmt)
703 {
704 tree fndecl;
705
706 if (!is_gimple_call (stmt))
707 return false;
708
709 fndecl = gimple_call_fndecl (stmt);
710 if (fndecl && fndecl_built_in_p (fndecl, BUILT_IN_NORMAL))
711 switch (DECL_FUNCTION_CODE (fndecl))
712 {
713 CASE_BUILT_IN_ALLOCA:
714 return gimple_call_num_args (stmt) > 0;
715 default:
716 break;
717 }
718
719 return false;
720 }
721
722 /* Return true when exp contains a builtin alloca call. */
723
724 bool
725 alloca_call_p (const_tree exp)
726 {
727 tree fndecl;
728 if (TREE_CODE (exp) == CALL_EXPR
729 && (fndecl = get_callee_fndecl (exp))
730 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
731 switch (DECL_FUNCTION_CODE (fndecl))
732 {
733 CASE_BUILT_IN_ALLOCA:
734 return true;
735 default:
736 break;
737 }
738
739 return false;
740 }
741
742 /* Return TRUE if FNDECL is either a TM builtin or a TM cloned
743 function. Return FALSE otherwise. */
744
745 static bool
746 is_tm_builtin (const_tree fndecl)
747 {
748 if (fndecl == NULL)
749 return false;
750
751 if (decl_is_tm_clone (fndecl))
752 return true;
753
754 if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
755 {
756 switch (DECL_FUNCTION_CODE (fndecl))
757 {
758 case BUILT_IN_TM_COMMIT:
759 case BUILT_IN_TM_COMMIT_EH:
760 case BUILT_IN_TM_ABORT:
761 case BUILT_IN_TM_IRREVOCABLE:
762 case BUILT_IN_TM_GETTMCLONE_IRR:
763 case BUILT_IN_TM_MEMCPY:
764 case BUILT_IN_TM_MEMMOVE:
765 case BUILT_IN_TM_MEMSET:
766 CASE_BUILT_IN_TM_STORE (1):
767 CASE_BUILT_IN_TM_STORE (2):
768 CASE_BUILT_IN_TM_STORE (4):
769 CASE_BUILT_IN_TM_STORE (8):
770 CASE_BUILT_IN_TM_STORE (FLOAT):
771 CASE_BUILT_IN_TM_STORE (DOUBLE):
772 CASE_BUILT_IN_TM_STORE (LDOUBLE):
773 CASE_BUILT_IN_TM_STORE (M64):
774 CASE_BUILT_IN_TM_STORE (M128):
775 CASE_BUILT_IN_TM_STORE (M256):
776 CASE_BUILT_IN_TM_LOAD (1):
777 CASE_BUILT_IN_TM_LOAD (2):
778 CASE_BUILT_IN_TM_LOAD (4):
779 CASE_BUILT_IN_TM_LOAD (8):
780 CASE_BUILT_IN_TM_LOAD (FLOAT):
781 CASE_BUILT_IN_TM_LOAD (DOUBLE):
782 CASE_BUILT_IN_TM_LOAD (LDOUBLE):
783 CASE_BUILT_IN_TM_LOAD (M64):
784 CASE_BUILT_IN_TM_LOAD (M128):
785 CASE_BUILT_IN_TM_LOAD (M256):
786 case BUILT_IN_TM_LOG:
787 case BUILT_IN_TM_LOG_1:
788 case BUILT_IN_TM_LOG_2:
789 case BUILT_IN_TM_LOG_4:
790 case BUILT_IN_TM_LOG_8:
791 case BUILT_IN_TM_LOG_FLOAT:
792 case BUILT_IN_TM_LOG_DOUBLE:
793 case BUILT_IN_TM_LOG_LDOUBLE:
794 case BUILT_IN_TM_LOG_M64:
795 case BUILT_IN_TM_LOG_M128:
796 case BUILT_IN_TM_LOG_M256:
797 return true;
798 default:
799 break;
800 }
801 }
802 return false;
803 }
804
805 /* Detect flags (function attributes) from the function decl or type node. */
806
807 int
808 flags_from_decl_or_type (const_tree exp)
809 {
810 int flags = 0;
811
812 if (DECL_P (exp))
813 {
814 /* The function exp may have the `malloc' attribute. */
815 if (DECL_IS_MALLOC (exp))
816 flags |= ECF_MALLOC;
817
818 /* The function exp may have the `returns_twice' attribute. */
819 if (DECL_IS_RETURNS_TWICE (exp))
820 flags |= ECF_RETURNS_TWICE;
821
822 /* Process the pure and const attributes. */
823 if (TREE_READONLY (exp))
824 flags |= ECF_CONST;
825 if (DECL_PURE_P (exp))
826 flags |= ECF_PURE;
827 if (DECL_LOOPING_CONST_OR_PURE_P (exp))
828 flags |= ECF_LOOPING_CONST_OR_PURE;
829
830 if (DECL_IS_NOVOPS (exp))
831 flags |= ECF_NOVOPS;
832 if (lookup_attribute ("leaf", DECL_ATTRIBUTES (exp)))
833 flags |= ECF_LEAF;
834 if (lookup_attribute ("cold", DECL_ATTRIBUTES (exp)))
835 flags |= ECF_COLD;
836
837 if (TREE_NOTHROW (exp))
838 flags |= ECF_NOTHROW;
839
840 if (flag_tm)
841 {
842 if (is_tm_builtin (exp))
843 flags |= ECF_TM_BUILTIN;
844 else if ((flags & (ECF_CONST|ECF_NOVOPS)) != 0
845 || lookup_attribute ("transaction_pure",
846 TYPE_ATTRIBUTES (TREE_TYPE (exp))))
847 flags |= ECF_TM_PURE;
848 }
849
850 flags = special_function_p (exp, flags);
851 }
852 else if (TYPE_P (exp))
853 {
854 if (TYPE_READONLY (exp))
855 flags |= ECF_CONST;
856
857 if (flag_tm
858 && ((flags & ECF_CONST) != 0
859 || lookup_attribute ("transaction_pure", TYPE_ATTRIBUTES (exp))))
860 flags |= ECF_TM_PURE;
861 }
862 else
863 gcc_unreachable ();
864
865 if (TREE_THIS_VOLATILE (exp))
866 {
867 flags |= ECF_NORETURN;
868 if (flags & (ECF_CONST|ECF_PURE))
869 flags |= ECF_LOOPING_CONST_OR_PURE;
870 }
871
872 return flags;
873 }
874
875 /* Detect flags from a CALL_EXPR. */
876
877 int
878 call_expr_flags (const_tree t)
879 {
880 int flags;
881 tree decl = get_callee_fndecl (t);
882
883 if (decl)
884 flags = flags_from_decl_or_type (decl);
885 else if (CALL_EXPR_FN (t) == NULL_TREE)
886 flags = internal_fn_flags (CALL_EXPR_IFN (t));
887 else
888 {
889 tree type = TREE_TYPE (CALL_EXPR_FN (t));
890 if (type && TREE_CODE (type) == POINTER_TYPE)
891 flags = flags_from_decl_or_type (TREE_TYPE (type));
892 else
893 flags = 0;
894 if (CALL_EXPR_BY_DESCRIPTOR (t))
895 flags |= ECF_BY_DESCRIPTOR;
896 }
897
898 return flags;
899 }
900
901 /* Return true if ARG should be passed by invisible reference. */
902
903 bool
904 pass_by_reference (CUMULATIVE_ARGS *ca, function_arg_info arg)
905 {
906 if (tree type = arg.type)
907 {
908 /* If this type contains non-trivial constructors, then it is
909 forbidden for the middle-end to create any new copies. */
910 if (TREE_ADDRESSABLE (type))
911 return true;
912
913 /* GCC post 3.4 passes *all* variable sized types by reference. */
914 if (!TYPE_SIZE (type) || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
915 return true;
916
917 /* If a record type should be passed the same as its first (and only)
918 member, use the type and mode of that member. */
919 if (TREE_CODE (type) == RECORD_TYPE && TYPE_TRANSPARENT_AGGR (type))
920 {
921 arg.type = TREE_TYPE (first_field (type));
922 arg.mode = TYPE_MODE (arg.type);
923 }
924 }
925
926 return targetm.calls.pass_by_reference (pack_cumulative_args (ca), arg);
927 }
928
929 /* Return true if TYPE should be passed by reference when passed to
930 the "..." arguments of a function. */
931
932 bool
933 pass_va_arg_by_reference (tree type)
934 {
935 return pass_by_reference (NULL, function_arg_info (type, /*named=*/false));
936 }
937
938 /* Decide whether ARG, which occurs in the state described by CA,
939 should be passed by reference. Return true if so and update
940 ARG accordingly. */
941
942 bool
943 apply_pass_by_reference_rules (CUMULATIVE_ARGS *ca, function_arg_info &arg)
944 {
945 if (pass_by_reference (ca, arg))
946 {
947 arg.type = build_pointer_type (arg.type);
948 arg.mode = TYPE_MODE (arg.type);
949 return true;
950 }
951 return false;
952 }
953
954 /* Return true if ARG, which is passed by reference, should be callee
955 copied instead of caller copied. */
956
957 bool
958 reference_callee_copied (CUMULATIVE_ARGS *ca, const function_arg_info &arg)
959 {
960 if (arg.type && TREE_ADDRESSABLE (arg.type))
961 return false;
962 return targetm.calls.callee_copies (pack_cumulative_args (ca), arg);
963 }
964
965
966 /* Precompute all register parameters as described by ARGS, storing values
967 into fields within the ARGS array.
968
969 NUM_ACTUALS indicates the total number elements in the ARGS array.
970
971 Set REG_PARM_SEEN if we encounter a register parameter. */
972
973 static void
974 precompute_register_parameters (int num_actuals, struct arg_data *args,
975 int *reg_parm_seen)
976 {
977 int i;
978
979 *reg_parm_seen = 0;
980
981 for (i = 0; i < num_actuals; i++)
982 if (args[i].reg != 0 && ! args[i].pass_on_stack)
983 {
984 *reg_parm_seen = 1;
985
986 if (args[i].value == 0)
987 {
988 push_temp_slots ();
989 args[i].value = expand_normal (args[i].tree_value);
990 preserve_temp_slots (args[i].value);
991 pop_temp_slots ();
992 }
993
994 /* If we are to promote the function arg to a wider mode,
995 do it now. */
996
997 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
998 args[i].value
999 = convert_modes (args[i].mode,
1000 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
1001 args[i].value, args[i].unsignedp);
1002
1003 /* If the value is a non-legitimate constant, force it into a
1004 pseudo now. TLS symbols sometimes need a call to resolve. */
1005 if (CONSTANT_P (args[i].value)
1006 && !targetm.legitimate_constant_p (args[i].mode, args[i].value))
1007 args[i].value = force_reg (args[i].mode, args[i].value);
1008
1009 /* If we're going to have to load the value by parts, pull the
1010 parts into pseudos. The part extraction process can involve
1011 non-trivial computation. */
1012 if (GET_CODE (args[i].reg) == PARALLEL)
1013 {
1014 tree type = TREE_TYPE (args[i].tree_value);
1015 args[i].parallel_value
1016 = emit_group_load_into_temps (args[i].reg, args[i].value,
1017 type, int_size_in_bytes (type));
1018 }
1019
1020 /* If the value is expensive, and we are inside an appropriately
1021 short loop, put the value into a pseudo and then put the pseudo
1022 into the hard reg.
1023
1024 For small register classes, also do this if this call uses
1025 register parameters. This is to avoid reload conflicts while
1026 loading the parameters registers. */
1027
1028 else if ((! (REG_P (args[i].value)
1029 || (GET_CODE (args[i].value) == SUBREG
1030 && REG_P (SUBREG_REG (args[i].value)))))
1031 && args[i].mode != BLKmode
1032 && (set_src_cost (args[i].value, args[i].mode,
1033 optimize_insn_for_speed_p ())
1034 > COSTS_N_INSNS (1))
1035 && ((*reg_parm_seen
1036 && targetm.small_register_classes_for_mode_p (args[i].mode))
1037 || optimize))
1038 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
1039 }
1040 }
1041
1042 #ifdef REG_PARM_STACK_SPACE
1043
1044 /* The argument list is the property of the called routine and it
1045 may clobber it. If the fixed area has been used for previous
1046 parameters, we must save and restore it. */
1047
1048 static rtx
1049 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
1050 {
1051 unsigned int low;
1052 unsigned int high;
1053
1054 /* Compute the boundary of the area that needs to be saved, if any. */
1055 high = reg_parm_stack_space;
1056 if (ARGS_GROW_DOWNWARD)
1057 high += 1;
1058
1059 if (high > highest_outgoing_arg_in_use)
1060 high = highest_outgoing_arg_in_use;
1061
1062 for (low = 0; low < high; low++)
1063 if (stack_usage_map[low] != 0 || low >= stack_usage_watermark)
1064 {
1065 int num_to_save;
1066 machine_mode save_mode;
1067 int delta;
1068 rtx addr;
1069 rtx stack_area;
1070 rtx save_area;
1071
1072 while (stack_usage_map[--high] == 0)
1073 ;
1074
1075 *low_to_save = low;
1076 *high_to_save = high;
1077
1078 num_to_save = high - low + 1;
1079
1080 /* If we don't have the required alignment, must do this
1081 in BLKmode. */
1082 scalar_int_mode imode;
1083 if (int_mode_for_size (num_to_save * BITS_PER_UNIT, 1).exists (&imode)
1084 && (low & (MIN (GET_MODE_SIZE (imode),
1085 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)) == 0)
1086 save_mode = imode;
1087 else
1088 save_mode = BLKmode;
1089
1090 if (ARGS_GROW_DOWNWARD)
1091 delta = -high;
1092 else
1093 delta = low;
1094
1095 addr = plus_constant (Pmode, argblock, delta);
1096 stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, addr));
1097
1098 set_mem_align (stack_area, PARM_BOUNDARY);
1099 if (save_mode == BLKmode)
1100 {
1101 save_area = assign_stack_temp (BLKmode, num_to_save);
1102 emit_block_move (validize_mem (save_area), stack_area,
1103 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
1104 }
1105 else
1106 {
1107 save_area = gen_reg_rtx (save_mode);
1108 emit_move_insn (save_area, stack_area);
1109 }
1110
1111 return save_area;
1112 }
1113
1114 return NULL_RTX;
1115 }
1116
1117 static void
1118 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
1119 {
1120 machine_mode save_mode = GET_MODE (save_area);
1121 int delta;
1122 rtx addr, stack_area;
1123
1124 if (ARGS_GROW_DOWNWARD)
1125 delta = -high_to_save;
1126 else
1127 delta = low_to_save;
1128
1129 addr = plus_constant (Pmode, argblock, delta);
1130 stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, addr));
1131 set_mem_align (stack_area, PARM_BOUNDARY);
1132
1133 if (save_mode != BLKmode)
1134 emit_move_insn (stack_area, save_area);
1135 else
1136 emit_block_move (stack_area, validize_mem (save_area),
1137 GEN_INT (high_to_save - low_to_save + 1),
1138 BLOCK_OP_CALL_PARM);
1139 }
1140 #endif /* REG_PARM_STACK_SPACE */
1141
1142 /* If any elements in ARGS refer to parameters that are to be passed in
1143 registers, but not in memory, and whose alignment does not permit a
1144 direct copy into registers. Copy the values into a group of pseudos
1145 which we will later copy into the appropriate hard registers.
1146
1147 Pseudos for each unaligned argument will be stored into the array
1148 args[argnum].aligned_regs. The caller is responsible for deallocating
1149 the aligned_regs array if it is nonzero. */
1150
1151 static void
1152 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
1153 {
1154 int i, j;
1155
1156 for (i = 0; i < num_actuals; i++)
1157 if (args[i].reg != 0 && ! args[i].pass_on_stack
1158 && GET_CODE (args[i].reg) != PARALLEL
1159 && args[i].mode == BLKmode
1160 && MEM_P (args[i].value)
1161 && (MEM_ALIGN (args[i].value)
1162 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
1163 {
1164 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1165 int endian_correction = 0;
1166
1167 if (args[i].partial)
1168 {
1169 gcc_assert (args[i].partial % UNITS_PER_WORD == 0);
1170 args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD;
1171 }
1172 else
1173 {
1174 args[i].n_aligned_regs
1175 = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
1176 }
1177
1178 args[i].aligned_regs = XNEWVEC (rtx, args[i].n_aligned_regs);
1179
1180 /* Structures smaller than a word are normally aligned to the
1181 least significant byte. On a BYTES_BIG_ENDIAN machine,
1182 this means we must skip the empty high order bytes when
1183 calculating the bit offset. */
1184 if (bytes < UNITS_PER_WORD
1185 #ifdef BLOCK_REG_PADDING
1186 && (BLOCK_REG_PADDING (args[i].mode,
1187 TREE_TYPE (args[i].tree_value), 1)
1188 == PAD_DOWNWARD)
1189 #else
1190 && BYTES_BIG_ENDIAN
1191 #endif
1192 )
1193 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
1194
1195 for (j = 0; j < args[i].n_aligned_regs; j++)
1196 {
1197 rtx reg = gen_reg_rtx (word_mode);
1198 rtx word = operand_subword_force (args[i].value, j, BLKmode);
1199 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
1200
1201 args[i].aligned_regs[j] = reg;
1202 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
1203 word_mode, word_mode, false, NULL);
1204
1205 /* There is no need to restrict this code to loading items
1206 in TYPE_ALIGN sized hunks. The bitfield instructions can
1207 load up entire word sized registers efficiently.
1208
1209 ??? This may not be needed anymore.
1210 We use to emit a clobber here but that doesn't let later
1211 passes optimize the instructions we emit. By storing 0 into
1212 the register later passes know the first AND to zero out the
1213 bitfield being set in the register is unnecessary. The store
1214 of 0 will be deleted as will at least the first AND. */
1215
1216 emit_move_insn (reg, const0_rtx);
1217
1218 bytes -= bitsize / BITS_PER_UNIT;
1219 store_bit_field (reg, bitsize, endian_correction, 0, 0,
1220 word_mode, word, false);
1221 }
1222 }
1223 }
1224
1225 /* The limit set by -Walloc-larger-than=. */
1226 static GTY(()) tree alloc_object_size_limit;
1227
1228 /* Initialize ALLOC_OBJECT_SIZE_LIMIT based on the -Walloc-size-larger-than=
1229 setting if the option is specified, or to the maximum object size if it
1230 is not. Return the initialized value. */
1231
1232 static tree
1233 alloc_max_size (void)
1234 {
1235 if (alloc_object_size_limit)
1236 return alloc_object_size_limit;
1237
1238 HOST_WIDE_INT limit = warn_alloc_size_limit;
1239 if (limit == HOST_WIDE_INT_MAX)
1240 limit = tree_to_shwi (TYPE_MAX_VALUE (ptrdiff_type_node));
1241
1242 alloc_object_size_limit = build_int_cst (size_type_node, limit);
1243
1244 return alloc_object_size_limit;
1245 }
1246
1247 /* Return true when EXP's range can be determined and set RANGE[] to it
1248 after adjusting it if necessary to make EXP a represents a valid size
1249 of object, or a valid size argument to an allocation function declared
1250 with attribute alloc_size (whose argument may be signed), or to a string
1251 manipulation function like memset. When ALLOW_ZERO is true, allow
1252 returning a range of [0, 0] for a size in an anti-range [1, N] where
1253 N > PTRDIFF_MAX. A zero range is a (nearly) invalid argument to
1254 allocation functions like malloc but it is a valid argument to
1255 functions like memset. */
1256
1257 bool
1258 get_size_range (tree exp, tree range[2], bool allow_zero /* = false */)
1259 {
1260 if (tree_fits_uhwi_p (exp))
1261 {
1262 /* EXP is a constant. */
1263 range[0] = range[1] = exp;
1264 return true;
1265 }
1266
1267 tree exptype = TREE_TYPE (exp);
1268 bool integral = INTEGRAL_TYPE_P (exptype);
1269
1270 wide_int min, max;
1271 enum value_range_kind range_type;
1272
1273 if (integral)
1274 range_type = determine_value_range (exp, &min, &max);
1275 else
1276 range_type = VR_VARYING;
1277
1278 if (range_type == VR_VARYING)
1279 {
1280 if (integral)
1281 {
1282 /* Use the full range of the type of the expression when
1283 no value range information is available. */
1284 range[0] = TYPE_MIN_VALUE (exptype);
1285 range[1] = TYPE_MAX_VALUE (exptype);
1286 return true;
1287 }
1288
1289 range[0] = NULL_TREE;
1290 range[1] = NULL_TREE;
1291 return false;
1292 }
1293
1294 unsigned expprec = TYPE_PRECISION (exptype);
1295
1296 bool signed_p = !TYPE_UNSIGNED (exptype);
1297
1298 if (range_type == VR_ANTI_RANGE)
1299 {
1300 if (signed_p)
1301 {
1302 if (wi::les_p (max, 0))
1303 {
1304 /* EXP is not in a strictly negative range. That means
1305 it must be in some (not necessarily strictly) positive
1306 range which includes zero. Since in signed to unsigned
1307 conversions negative values end up converted to large
1308 positive values, and otherwise they are not valid sizes,
1309 the resulting range is in both cases [0, TYPE_MAX]. */
1310 min = wi::zero (expprec);
1311 max = wi::to_wide (TYPE_MAX_VALUE (exptype));
1312 }
1313 else if (wi::les_p (min - 1, 0))
1314 {
1315 /* EXP is not in a negative-positive range. That means EXP
1316 is either negative, or greater than max. Since negative
1317 sizes are invalid make the range [MAX + 1, TYPE_MAX]. */
1318 min = max + 1;
1319 max = wi::to_wide (TYPE_MAX_VALUE (exptype));
1320 }
1321 else
1322 {
1323 max = min - 1;
1324 min = wi::zero (expprec);
1325 }
1326 }
1327 else if (wi::eq_p (0, min - 1))
1328 {
1329 /* EXP is unsigned and not in the range [1, MAX]. That means
1330 it's either zero or greater than MAX. Even though 0 would
1331 normally be detected by -Walloc-zero, unless ALLOW_ZERO
1332 is true, set the range to [MAX, TYPE_MAX] so that when MAX
1333 is greater than the limit the whole range is diagnosed. */
1334 if (allow_zero)
1335 min = max = wi::zero (expprec);
1336 else
1337 {
1338 min = max + 1;
1339 max = wi::to_wide (TYPE_MAX_VALUE (exptype));
1340 }
1341 }
1342 else
1343 {
1344 max = min - 1;
1345 min = wi::zero (expprec);
1346 }
1347 }
1348
1349 range[0] = wide_int_to_tree (exptype, min);
1350 range[1] = wide_int_to_tree (exptype, max);
1351
1352 return true;
1353 }
1354
1355 /* Diagnose a call EXP to function FN decorated with attribute alloc_size
1356 whose argument numbers given by IDX with values given by ARGS exceed
1357 the maximum object size or cause an unsigned oveflow (wrapping) when
1358 multiplied. FN is null when EXP is a call via a function pointer.
1359 When ARGS[0] is null the function does nothing. ARGS[1] may be null
1360 for functions like malloc, and non-null for those like calloc that
1361 are decorated with a two-argument attribute alloc_size. */
1362
1363 void
1364 maybe_warn_alloc_args_overflow (tree fn, tree exp, tree args[2], int idx[2])
1365 {
1366 /* The range each of the (up to) two arguments is known to be in. */
1367 tree argrange[2][2] = { { NULL_TREE, NULL_TREE }, { NULL_TREE, NULL_TREE } };
1368
1369 /* Maximum object size set by -Walloc-size-larger-than= or SIZE_MAX / 2. */
1370 tree maxobjsize = alloc_max_size ();
1371
1372 location_t loc = EXPR_LOCATION (exp);
1373
1374 tree fntype = fn ? TREE_TYPE (fn) : TREE_TYPE (TREE_TYPE (exp));
1375 bool warned = false;
1376
1377 /* Validate each argument individually. */
1378 for (unsigned i = 0; i != 2 && args[i]; ++i)
1379 {
1380 if (TREE_CODE (args[i]) == INTEGER_CST)
1381 {
1382 argrange[i][0] = args[i];
1383 argrange[i][1] = args[i];
1384
1385 if (tree_int_cst_lt (args[i], integer_zero_node))
1386 {
1387 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1388 "%Kargument %i value %qE is negative",
1389 exp, idx[i] + 1, args[i]);
1390 }
1391 else if (integer_zerop (args[i]))
1392 {
1393 /* Avoid issuing -Walloc-zero for allocation functions other
1394 than __builtin_alloca that are declared with attribute
1395 returns_nonnull because there's no portability risk. This
1396 avoids warning for such calls to libiberty's xmalloc and
1397 friends.
1398 Also avoid issuing the warning for calls to function named
1399 "alloca". */
1400 if (fn && fndecl_built_in_p (fn, BUILT_IN_ALLOCA)
1401 ? IDENTIFIER_LENGTH (DECL_NAME (fn)) != 6
1402 : !lookup_attribute ("returns_nonnull",
1403 TYPE_ATTRIBUTES (fntype)))
1404 warned = warning_at (loc, OPT_Walloc_zero,
1405 "%Kargument %i value is zero",
1406 exp, idx[i] + 1);
1407 }
1408 else if (tree_int_cst_lt (maxobjsize, args[i]))
1409 {
1410 /* G++ emits calls to ::operator new[](SIZE_MAX) in C++98
1411 mode and with -fno-exceptions as a way to indicate array
1412 size overflow. There's no good way to detect C++98 here
1413 so avoid diagnosing these calls for all C++ modes. */
1414 if (i == 0
1415 && fn
1416 && !args[1]
1417 && lang_GNU_CXX ()
1418 && DECL_IS_OPERATOR_NEW_P (fn)
1419 && integer_all_onesp (args[i]))
1420 continue;
1421
1422 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1423 "%Kargument %i value %qE exceeds "
1424 "maximum object size %E",
1425 exp, idx[i] + 1, args[i], maxobjsize);
1426 }
1427 }
1428 else if (TREE_CODE (args[i]) == SSA_NAME
1429 && get_size_range (args[i], argrange[i]))
1430 {
1431 /* Verify that the argument's range is not negative (including
1432 upper bound of zero). */
1433 if (tree_int_cst_lt (argrange[i][0], integer_zero_node)
1434 && tree_int_cst_le (argrange[i][1], integer_zero_node))
1435 {
1436 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1437 "%Kargument %i range [%E, %E] is negative",
1438 exp, idx[i] + 1,
1439 argrange[i][0], argrange[i][1]);
1440 }
1441 else if (tree_int_cst_lt (maxobjsize, argrange[i][0]))
1442 {
1443 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1444 "%Kargument %i range [%E, %E] exceeds "
1445 "maximum object size %E",
1446 exp, idx[i] + 1,
1447 argrange[i][0], argrange[i][1],
1448 maxobjsize);
1449 }
1450 }
1451 }
1452
1453 if (!argrange[0])
1454 return;
1455
1456 /* For a two-argument alloc_size, validate the product of the two
1457 arguments if both of their values or ranges are known. */
1458 if (!warned && tree_fits_uhwi_p (argrange[0][0])
1459 && argrange[1][0] && tree_fits_uhwi_p (argrange[1][0])
1460 && !integer_onep (argrange[0][0])
1461 && !integer_onep (argrange[1][0]))
1462 {
1463 /* Check for overflow in the product of a function decorated with
1464 attribute alloc_size (X, Y). */
1465 unsigned szprec = TYPE_PRECISION (size_type_node);
1466 wide_int x = wi::to_wide (argrange[0][0], szprec);
1467 wide_int y = wi::to_wide (argrange[1][0], szprec);
1468
1469 wi::overflow_type vflow;
1470 wide_int prod = wi::umul (x, y, &vflow);
1471
1472 if (vflow)
1473 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1474 "%Kproduct %<%E * %E%> of arguments %i and %i "
1475 "exceeds %<SIZE_MAX%>",
1476 exp, argrange[0][0], argrange[1][0],
1477 idx[0] + 1, idx[1] + 1);
1478 else if (wi::ltu_p (wi::to_wide (maxobjsize, szprec), prod))
1479 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1480 "%Kproduct %<%E * %E%> of arguments %i and %i "
1481 "exceeds maximum object size %E",
1482 exp, argrange[0][0], argrange[1][0],
1483 idx[0] + 1, idx[1] + 1,
1484 maxobjsize);
1485
1486 if (warned)
1487 {
1488 /* Print the full range of each of the two arguments to make
1489 it clear when it is, in fact, in a range and not constant. */
1490 if (argrange[0][0] != argrange [0][1])
1491 inform (loc, "argument %i in the range [%E, %E]",
1492 idx[0] + 1, argrange[0][0], argrange[0][1]);
1493 if (argrange[1][0] != argrange [1][1])
1494 inform (loc, "argument %i in the range [%E, %E]",
1495 idx[1] + 1, argrange[1][0], argrange[1][1]);
1496 }
1497 }
1498
1499 if (warned && fn)
1500 {
1501 location_t fnloc = DECL_SOURCE_LOCATION (fn);
1502
1503 if (DECL_IS_BUILTIN (fn))
1504 inform (loc,
1505 "in a call to built-in allocation function %qD", fn);
1506 else
1507 inform (fnloc,
1508 "in a call to allocation function %qD declared here", fn);
1509 }
1510 }
1511
1512 /* If EXPR refers to a character array or pointer declared attribute
1513 nonstring return a decl for that array or pointer and set *REF to
1514 the referenced enclosing object or pointer. Otherwise returns
1515 null. */
1516
1517 tree
1518 get_attr_nonstring_decl (tree expr, tree *ref)
1519 {
1520 tree decl = expr;
1521 tree var = NULL_TREE;
1522 if (TREE_CODE (decl) == SSA_NAME)
1523 {
1524 gimple *def = SSA_NAME_DEF_STMT (decl);
1525
1526 if (is_gimple_assign (def))
1527 {
1528 tree_code code = gimple_assign_rhs_code (def);
1529 if (code == ADDR_EXPR
1530 || code == COMPONENT_REF
1531 || code == VAR_DECL)
1532 decl = gimple_assign_rhs1 (def);
1533 }
1534 else
1535 var = SSA_NAME_VAR (decl);
1536 }
1537
1538 if (TREE_CODE (decl) == ADDR_EXPR)
1539 decl = TREE_OPERAND (decl, 0);
1540
1541 /* To simplify calling code, store the referenced DECL regardless of
1542 the attribute determined below, but avoid storing the SSA_NAME_VAR
1543 obtained above (it's not useful for dataflow purposes). */
1544 if (ref)
1545 *ref = decl;
1546
1547 /* Use the SSA_NAME_VAR that was determined above to see if it's
1548 declared nonstring. Otherwise drill down into the referenced
1549 DECL. */
1550 if (var)
1551 decl = var;
1552 else if (TREE_CODE (decl) == ARRAY_REF)
1553 decl = TREE_OPERAND (decl, 0);
1554 else if (TREE_CODE (decl) == COMPONENT_REF)
1555 decl = TREE_OPERAND (decl, 1);
1556 else if (TREE_CODE (decl) == MEM_REF)
1557 return get_attr_nonstring_decl (TREE_OPERAND (decl, 0), ref);
1558
1559 if (DECL_P (decl)
1560 && lookup_attribute ("nonstring", DECL_ATTRIBUTES (decl)))
1561 return decl;
1562
1563 return NULL_TREE;
1564 }
1565
1566 /* Warn about passing a non-string array/pointer to a function that
1567 expects a nul-terminated string argument. */
1568
1569 void
1570 maybe_warn_nonstring_arg (tree fndecl, tree exp)
1571 {
1572 if (!fndecl || !fndecl_built_in_p (fndecl, BUILT_IN_NORMAL))
1573 return;
1574
1575 if (TREE_NO_WARNING (exp) || !warn_stringop_overflow)
1576 return;
1577
1578 /* Avoid clearly invalid calls (more checking done below). */
1579 unsigned nargs = call_expr_nargs (exp);
1580 if (!nargs)
1581 return;
1582
1583 /* The bound argument to a bounded string function like strncpy. */
1584 tree bound = NULL_TREE;
1585
1586 /* The longest known or possible string argument to one of the comparison
1587 functions. If the length is less than the bound it is used instead.
1588 Since the length is only used for warning and not for code generation
1589 disable strict mode in the calls to get_range_strlen below. */
1590 tree maxlen = NULL_TREE;
1591
1592 /* It's safe to call "bounded" string functions with a non-string
1593 argument since the functions provide an explicit bound for this
1594 purpose. The exception is strncat where the bound may refer to
1595 either the destination or the source. */
1596 int fncode = DECL_FUNCTION_CODE (fndecl);
1597 switch (fncode)
1598 {
1599 case BUILT_IN_STRCMP:
1600 case BUILT_IN_STRNCMP:
1601 case BUILT_IN_STRNCASECMP:
1602 {
1603 /* For these, if one argument refers to one or more of a set
1604 of string constants or arrays of known size, determine
1605 the range of their known or possible lengths and use it
1606 conservatively as the bound for the unbounded function,
1607 and to adjust the range of the bound of the bounded ones. */
1608 for (unsigned argno = 0;
1609 argno < MIN (nargs, 2)
1610 && !(maxlen && TREE_CODE (maxlen) == INTEGER_CST); argno++)
1611 {
1612 tree arg = CALL_EXPR_ARG (exp, argno);
1613 if (!get_attr_nonstring_decl (arg))
1614 {
1615 c_strlen_data lendata = { };
1616 get_range_strlen (arg, &lendata, /* eltsize = */ 1);
1617 maxlen = lendata.maxbound;
1618 }
1619 }
1620 }
1621 /* Fall through. */
1622
1623 case BUILT_IN_STRNCAT:
1624 case BUILT_IN_STPNCPY:
1625 case BUILT_IN_STRNCPY:
1626 if (nargs > 2)
1627 bound = CALL_EXPR_ARG (exp, 2);
1628 break;
1629
1630 case BUILT_IN_STRNDUP:
1631 if (nargs > 1)
1632 bound = CALL_EXPR_ARG (exp, 1);
1633 break;
1634
1635 case BUILT_IN_STRNLEN:
1636 {
1637 tree arg = CALL_EXPR_ARG (exp, 0);
1638 if (!get_attr_nonstring_decl (arg))
1639 {
1640 c_strlen_data lendata = { };
1641 get_range_strlen (arg, &lendata, /* eltsize = */ 1);
1642 maxlen = lendata.maxbound;
1643 }
1644 if (nargs > 1)
1645 bound = CALL_EXPR_ARG (exp, 1);
1646 break;
1647 }
1648
1649 default:
1650 break;
1651 }
1652
1653 /* Determine the range of the bound argument (if specified). */
1654 tree bndrng[2] = { NULL_TREE, NULL_TREE };
1655 if (bound)
1656 {
1657 STRIP_NOPS (bound);
1658 get_size_range (bound, bndrng);
1659 }
1660
1661 location_t loc = EXPR_LOCATION (exp);
1662
1663 if (bndrng[0])
1664 {
1665 /* Diagnose excessive bound prior the adjustment below and
1666 regardless of attribute nonstring. */
1667 tree maxobjsize = max_object_size ();
1668 if (tree_int_cst_lt (maxobjsize, bndrng[0]))
1669 {
1670 if (tree_int_cst_equal (bndrng[0], bndrng[1]))
1671 warning_at (loc, OPT_Wstringop_overflow_,
1672 "%K%qD specified bound %E "
1673 "exceeds maximum object size %E",
1674 exp, fndecl, bndrng[0], maxobjsize);
1675 else
1676 warning_at (loc, OPT_Wstringop_overflow_,
1677 "%K%qD specified bound [%E, %E] "
1678 "exceeds maximum object size %E",
1679 exp, fndecl, bndrng[0], bndrng[1], maxobjsize);
1680 return;
1681 }
1682 }
1683
1684 if (maxlen && !integer_all_onesp (maxlen))
1685 {
1686 /* Add one for the nul. */
1687 maxlen = const_binop (PLUS_EXPR, TREE_TYPE (maxlen), maxlen,
1688 size_one_node);
1689
1690 if (!bndrng[0])
1691 {
1692 /* Conservatively use the upper bound of the lengths for
1693 both the lower and the upper bound of the operation. */
1694 bndrng[0] = maxlen;
1695 bndrng[1] = maxlen;
1696 bound = void_type_node;
1697 }
1698 else if (maxlen)
1699 {
1700 /* Replace the bound on the operation with the upper bound
1701 of the length of the string if the latter is smaller. */
1702 if (tree_int_cst_lt (maxlen, bndrng[0]))
1703 bndrng[0] = maxlen;
1704 else if (tree_int_cst_lt (maxlen, bndrng[1]))
1705 bndrng[1] = maxlen;
1706 }
1707 }
1708
1709 /* Iterate over the built-in function's formal arguments and check
1710 each const char* against the actual argument. If the actual
1711 argument is declared attribute non-string issue a warning unless
1712 the argument's maximum length is bounded. */
1713 function_args_iterator it;
1714 function_args_iter_init (&it, TREE_TYPE (fndecl));
1715
1716 for (unsigned argno = 0; ; ++argno, function_args_iter_next (&it))
1717 {
1718 /* Avoid iterating past the declared argument in a call
1719 to function declared without a prototype. */
1720 if (argno >= nargs)
1721 break;
1722
1723 tree argtype = function_args_iter_cond (&it);
1724 if (!argtype)
1725 break;
1726
1727 if (TREE_CODE (argtype) != POINTER_TYPE)
1728 continue;
1729
1730 argtype = TREE_TYPE (argtype);
1731
1732 if (TREE_CODE (argtype) != INTEGER_TYPE
1733 || !TYPE_READONLY (argtype))
1734 continue;
1735
1736 argtype = TYPE_MAIN_VARIANT (argtype);
1737 if (argtype != char_type_node)
1738 continue;
1739
1740 tree callarg = CALL_EXPR_ARG (exp, argno);
1741 if (TREE_CODE (callarg) == ADDR_EXPR)
1742 callarg = TREE_OPERAND (callarg, 0);
1743
1744 /* See if the destination is declared with attribute "nonstring". */
1745 tree decl = get_attr_nonstring_decl (callarg);
1746 if (!decl)
1747 continue;
1748
1749 /* The maximum number of array elements accessed. */
1750 offset_int wibnd = 0;
1751
1752 if (argno && fncode == BUILT_IN_STRNCAT)
1753 {
1754 /* See if the bound in strncat is derived from the length
1755 of the strlen of the destination (as it's expected to be).
1756 If so, reset BOUND and FNCODE to trigger a warning. */
1757 tree dstarg = CALL_EXPR_ARG (exp, 0);
1758 if (is_strlen_related_p (dstarg, bound))
1759 {
1760 /* The bound applies to the destination, not to the source,
1761 so reset these to trigger a warning without mentioning
1762 the bound. */
1763 bound = NULL;
1764 fncode = 0;
1765 }
1766 else if (bndrng[1])
1767 /* Use the upper bound of the range for strncat. */
1768 wibnd = wi::to_offset (bndrng[1]);
1769 }
1770 else if (bndrng[0])
1771 /* Use the lower bound of the range for functions other than
1772 strncat. */
1773 wibnd = wi::to_offset (bndrng[0]);
1774
1775 /* Determine the size of the argument array if it is one. */
1776 offset_int asize = wibnd;
1777 bool known_size = false;
1778 tree type = TREE_TYPE (decl);
1779
1780 /* Determine the array size. For arrays of unknown bound and
1781 pointers reset BOUND to trigger the appropriate warning. */
1782 if (TREE_CODE (type) == ARRAY_TYPE)
1783 {
1784 if (tree arrbnd = TYPE_DOMAIN (type))
1785 {
1786 if ((arrbnd = TYPE_MAX_VALUE (arrbnd)))
1787 {
1788 asize = wi::to_offset (arrbnd) + 1;
1789 known_size = true;
1790 }
1791 }
1792 else if (bound == void_type_node)
1793 bound = NULL_TREE;
1794 }
1795 else if (bound == void_type_node)
1796 bound = NULL_TREE;
1797
1798 /* In a call to strncat with a bound in a range whose lower but
1799 not upper bound is less than the array size, reset ASIZE to
1800 be the same as the bound and the other variable to trigger
1801 the apprpriate warning below. */
1802 if (fncode == BUILT_IN_STRNCAT
1803 && bndrng[0] != bndrng[1]
1804 && wi::ltu_p (wi::to_offset (bndrng[0]), asize)
1805 && (!known_size
1806 || wi::ltu_p (asize, wibnd)))
1807 {
1808 asize = wibnd;
1809 bound = NULL_TREE;
1810 fncode = 0;
1811 }
1812
1813 bool warned = false;
1814
1815 auto_diagnostic_group d;
1816 if (wi::ltu_p (asize, wibnd))
1817 {
1818 if (bndrng[0] == bndrng[1])
1819 warned = warning_at (loc, OPT_Wstringop_overflow_,
1820 "%qD argument %i declared attribute "
1821 "%<nonstring%> is smaller than the specified "
1822 "bound %wu",
1823 fndecl, argno + 1, wibnd.to_uhwi ());
1824 else if (wi::ltu_p (asize, wi::to_offset (bndrng[0])))
1825 warned = warning_at (loc, OPT_Wstringop_overflow_,
1826 "%qD argument %i declared attribute "
1827 "%<nonstring%> is smaller than "
1828 "the specified bound [%E, %E]",
1829 fndecl, argno + 1, bndrng[0], bndrng[1]);
1830 else
1831 warned = warning_at (loc, OPT_Wstringop_overflow_,
1832 "%qD argument %i declared attribute "
1833 "%<nonstring%> may be smaller than "
1834 "the specified bound [%E, %E]",
1835 fndecl, argno + 1, bndrng[0], bndrng[1]);
1836 }
1837 else if (fncode == BUILT_IN_STRNCAT)
1838 ; /* Avoid warning for calls to strncat() when the bound
1839 is equal to the size of the non-string argument. */
1840 else if (!bound)
1841 warned = warning_at (loc, OPT_Wstringop_overflow_,
1842 "%qD argument %i declared attribute %<nonstring%>",
1843 fndecl, argno + 1);
1844
1845 if (warned)
1846 inform (DECL_SOURCE_LOCATION (decl),
1847 "argument %qD declared here", decl);
1848 }
1849 }
1850
1851 /* Issue an error if CALL_EXPR was flagged as requiring
1852 tall-call optimization. */
1853
1854 static void
1855 maybe_complain_about_tail_call (tree call_expr, const char *reason)
1856 {
1857 gcc_assert (TREE_CODE (call_expr) == CALL_EXPR);
1858 if (!CALL_EXPR_MUST_TAIL_CALL (call_expr))
1859 return;
1860
1861 error_at (EXPR_LOCATION (call_expr), "cannot tail-call: %s", reason);
1862 }
1863
1864 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
1865 CALL_EXPR EXP.
1866
1867 NUM_ACTUALS is the total number of parameters.
1868
1869 N_NAMED_ARGS is the total number of named arguments.
1870
1871 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
1872 value, or null.
1873
1874 FNDECL is the tree code for the target of this call (if known)
1875
1876 ARGS_SO_FAR holds state needed by the target to know where to place
1877 the next argument.
1878
1879 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1880 for arguments which are passed in registers.
1881
1882 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1883 and may be modified by this routine.
1884
1885 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1886 flags which may be modified by this routine.
1887
1888 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
1889 that requires allocation of stack space.
1890
1891 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
1892 the thunked-to function. */
1893
1894 static void
1895 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
1896 struct arg_data *args,
1897 struct args_size *args_size,
1898 int n_named_args ATTRIBUTE_UNUSED,
1899 tree exp, tree struct_value_addr_value,
1900 tree fndecl, tree fntype,
1901 cumulative_args_t args_so_far,
1902 int reg_parm_stack_space,
1903 rtx *old_stack_level,
1904 poly_int64_pod *old_pending_adj,
1905 int *must_preallocate, int *ecf_flags,
1906 bool *may_tailcall, bool call_from_thunk_p)
1907 {
1908 CUMULATIVE_ARGS *args_so_far_pnt = get_cumulative_args (args_so_far);
1909 location_t loc = EXPR_LOCATION (exp);
1910
1911 /* Count arg position in order args appear. */
1912 int argpos;
1913
1914 int i;
1915
1916 args_size->constant = 0;
1917 args_size->var = 0;
1918
1919 bitmap_obstack_initialize (NULL);
1920
1921 /* In this loop, we consider args in the order they are written.
1922 We fill up ARGS from the back. */
1923
1924 i = num_actuals - 1;
1925 {
1926 int j = i;
1927 call_expr_arg_iterator iter;
1928 tree arg;
1929 bitmap slots = NULL;
1930
1931 if (struct_value_addr_value)
1932 {
1933 args[j].tree_value = struct_value_addr_value;
1934 j--;
1935 }
1936 argpos = 0;
1937 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
1938 {
1939 tree argtype = TREE_TYPE (arg);
1940
1941 if (targetm.calls.split_complex_arg
1942 && argtype
1943 && TREE_CODE (argtype) == COMPLEX_TYPE
1944 && targetm.calls.split_complex_arg (argtype))
1945 {
1946 tree subtype = TREE_TYPE (argtype);
1947 args[j].tree_value = build1 (REALPART_EXPR, subtype, arg);
1948 j--;
1949 args[j].tree_value = build1 (IMAGPART_EXPR, subtype, arg);
1950 }
1951 else
1952 args[j].tree_value = arg;
1953 j--;
1954 argpos++;
1955 }
1956
1957 if (slots)
1958 BITMAP_FREE (slots);
1959 }
1960
1961 bitmap_obstack_release (NULL);
1962
1963 /* Extract attribute alloc_size from the type of the called expression
1964 (which could be a function or a function pointer) and if set, store
1965 the indices of the corresponding arguments in ALLOC_IDX, and then
1966 the actual argument(s) at those indices in ALLOC_ARGS. */
1967 int alloc_idx[2] = { -1, -1 };
1968 if (tree alloc_size = lookup_attribute ("alloc_size",
1969 TYPE_ATTRIBUTES (fntype)))
1970 {
1971 tree args = TREE_VALUE (alloc_size);
1972 alloc_idx[0] = TREE_INT_CST_LOW (TREE_VALUE (args)) - 1;
1973 if (TREE_CHAIN (args))
1974 alloc_idx[1] = TREE_INT_CST_LOW (TREE_VALUE (TREE_CHAIN (args))) - 1;
1975 }
1976
1977 /* Array for up to the two attribute alloc_size arguments. */
1978 tree alloc_args[] = { NULL_TREE, NULL_TREE };
1979
1980 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1981 for (argpos = 0; argpos < num_actuals; i--, argpos++)
1982 {
1983 tree type = TREE_TYPE (args[i].tree_value);
1984 int unsignedp;
1985 machine_mode mode;
1986
1987 /* Replace erroneous argument with constant zero. */
1988 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1989 args[i].tree_value = integer_zero_node, type = integer_type_node;
1990
1991 /* If TYPE is a transparent union or record, pass things the way
1992 we would pass the first field of the union or record. We have
1993 already verified that the modes are the same. */
1994 if ((TREE_CODE (type) == UNION_TYPE || TREE_CODE (type) == RECORD_TYPE)
1995 && TYPE_TRANSPARENT_AGGR (type))
1996 type = TREE_TYPE (first_field (type));
1997
1998 /* Decide where to pass this arg.
1999
2000 args[i].reg is nonzero if all or part is passed in registers.
2001
2002 args[i].partial is nonzero if part but not all is passed in registers,
2003 and the exact value says how many bytes are passed in registers.
2004
2005 args[i].pass_on_stack is nonzero if the argument must at least be
2006 computed on the stack. It may then be loaded back into registers
2007 if args[i].reg is nonzero.
2008
2009 These decisions are driven by the FUNCTION_... macros and must agree
2010 with those made by function.c. */
2011
2012 /* See if this argument should be passed by invisible reference. */
2013 function_arg_info orig_arg (type, argpos < n_named_args);
2014 if (pass_by_reference (args_so_far_pnt, orig_arg))
2015 {
2016 bool callee_copies;
2017 tree base = NULL_TREE;
2018
2019 callee_copies = reference_callee_copied (args_so_far_pnt, orig_arg);
2020
2021 /* If we're compiling a thunk, pass through invisible references
2022 instead of making a copy. */
2023 if (call_from_thunk_p
2024 || (callee_copies
2025 && !TREE_ADDRESSABLE (type)
2026 && (base = get_base_address (args[i].tree_value))
2027 && TREE_CODE (base) != SSA_NAME
2028 && (!DECL_P (base) || MEM_P (DECL_RTL (base)))))
2029 {
2030 /* We may have turned the parameter value into an SSA name.
2031 Go back to the original parameter so we can take the
2032 address. */
2033 if (TREE_CODE (args[i].tree_value) == SSA_NAME)
2034 {
2035 gcc_assert (SSA_NAME_IS_DEFAULT_DEF (args[i].tree_value));
2036 args[i].tree_value = SSA_NAME_VAR (args[i].tree_value);
2037 gcc_assert (TREE_CODE (args[i].tree_value) == PARM_DECL);
2038 }
2039 /* Argument setup code may have copied the value to register. We
2040 revert that optimization now because the tail call code must
2041 use the original location. */
2042 if (TREE_CODE (args[i].tree_value) == PARM_DECL
2043 && !MEM_P (DECL_RTL (args[i].tree_value))
2044 && DECL_INCOMING_RTL (args[i].tree_value)
2045 && MEM_P (DECL_INCOMING_RTL (args[i].tree_value)))
2046 set_decl_rtl (args[i].tree_value,
2047 DECL_INCOMING_RTL (args[i].tree_value));
2048
2049 mark_addressable (args[i].tree_value);
2050
2051 /* We can't use sibcalls if a callee-copied argument is
2052 stored in the current function's frame. */
2053 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
2054 {
2055 *may_tailcall = false;
2056 maybe_complain_about_tail_call (exp,
2057 "a callee-copied argument is"
2058 " stored in the current"
2059 " function's frame");
2060 }
2061
2062 args[i].tree_value = build_fold_addr_expr_loc (loc,
2063 args[i].tree_value);
2064 type = TREE_TYPE (args[i].tree_value);
2065
2066 if (*ecf_flags & ECF_CONST)
2067 *ecf_flags &= ~(ECF_CONST | ECF_LOOPING_CONST_OR_PURE);
2068 }
2069 else
2070 {
2071 /* We make a copy of the object and pass the address to the
2072 function being called. */
2073 rtx copy;
2074
2075 if (!COMPLETE_TYPE_P (type)
2076 || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST
2077 || (flag_stack_check == GENERIC_STACK_CHECK
2078 && compare_tree_int (TYPE_SIZE_UNIT (type),
2079 STACK_CHECK_MAX_VAR_SIZE) > 0))
2080 {
2081 /* This is a variable-sized object. Make space on the stack
2082 for it. */
2083 rtx size_rtx = expr_size (args[i].tree_value);
2084
2085 if (*old_stack_level == 0)
2086 {
2087 emit_stack_save (SAVE_BLOCK, old_stack_level);
2088 *old_pending_adj = pending_stack_adjust;
2089 pending_stack_adjust = 0;
2090 }
2091
2092 /* We can pass TRUE as the 4th argument because we just
2093 saved the stack pointer and will restore it right after
2094 the call. */
2095 copy = allocate_dynamic_stack_space (size_rtx,
2096 TYPE_ALIGN (type),
2097 TYPE_ALIGN (type),
2098 max_int_size_in_bytes
2099 (type),
2100 true);
2101 copy = gen_rtx_MEM (BLKmode, copy);
2102 set_mem_attributes (copy, type, 1);
2103 }
2104 else
2105 copy = assign_temp (type, 1, 0);
2106
2107 store_expr (args[i].tree_value, copy, 0, false, false);
2108
2109 /* Just change the const function to pure and then let
2110 the next test clear the pure based on
2111 callee_copies. */
2112 if (*ecf_flags & ECF_CONST)
2113 {
2114 *ecf_flags &= ~ECF_CONST;
2115 *ecf_flags |= ECF_PURE;
2116 }
2117
2118 if (!callee_copies && *ecf_flags & ECF_PURE)
2119 *ecf_flags &= ~(ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
2120
2121 args[i].tree_value
2122 = build_fold_addr_expr_loc (loc, make_tree (type, copy));
2123 type = TREE_TYPE (args[i].tree_value);
2124 *may_tailcall = false;
2125 maybe_complain_about_tail_call (exp,
2126 "argument must be passed"
2127 " by copying");
2128 }
2129 }
2130
2131 unsignedp = TYPE_UNSIGNED (type);
2132 mode = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
2133 fndecl ? TREE_TYPE (fndecl) : fntype, 0);
2134
2135 args[i].unsignedp = unsignedp;
2136 args[i].mode = mode;
2137
2138 targetm.calls.warn_parameter_passing_abi (args_so_far, type);
2139
2140 function_arg_info arg (type, mode, argpos < n_named_args);
2141 args[i].reg = targetm.calls.function_arg (args_so_far, arg);
2142
2143 if (args[i].reg && CONST_INT_P (args[i].reg))
2144 args[i].reg = NULL;
2145
2146 /* If this is a sibling call and the machine has register windows, the
2147 register window has to be unwinded before calling the routine, so
2148 arguments have to go into the incoming registers. */
2149 if (targetm.calls.function_incoming_arg != targetm.calls.function_arg)
2150 args[i].tail_call_reg
2151 = targetm.calls.function_incoming_arg (args_so_far, arg);
2152 else
2153 args[i].tail_call_reg = args[i].reg;
2154
2155 if (args[i].reg)
2156 args[i].partial = targetm.calls.arg_partial_bytes (args_so_far, arg);
2157
2158 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (arg);
2159
2160 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
2161 it means that we are to pass this arg in the register(s) designated
2162 by the PARALLEL, but also to pass it in the stack. */
2163 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
2164 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
2165 args[i].pass_on_stack = 1;
2166
2167 /* If this is an addressable type, we must preallocate the stack
2168 since we must evaluate the object into its final location.
2169
2170 If this is to be passed in both registers and the stack, it is simpler
2171 to preallocate. */
2172 if (TREE_ADDRESSABLE (type)
2173 || (args[i].pass_on_stack && args[i].reg != 0))
2174 *must_preallocate = 1;
2175
2176 /* Compute the stack-size of this argument. */
2177 if (args[i].reg == 0 || args[i].partial != 0
2178 || reg_parm_stack_space > 0
2179 || args[i].pass_on_stack)
2180 locate_and_pad_parm (mode, type,
2181 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2182 1,
2183 #else
2184 args[i].reg != 0,
2185 #endif
2186 reg_parm_stack_space,
2187 args[i].pass_on_stack ? 0 : args[i].partial,
2188 fndecl, args_size, &args[i].locate);
2189 #ifdef BLOCK_REG_PADDING
2190 else
2191 /* The argument is passed entirely in registers. See at which
2192 end it should be padded. */
2193 args[i].locate.where_pad =
2194 BLOCK_REG_PADDING (mode, type,
2195 int_size_in_bytes (type) <= UNITS_PER_WORD);
2196 #endif
2197
2198 /* Update ARGS_SIZE, the total stack space for args so far. */
2199
2200 args_size->constant += args[i].locate.size.constant;
2201 if (args[i].locate.size.var)
2202 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
2203
2204 /* Increment ARGS_SO_FAR, which has info about which arg-registers
2205 have been used, etc. */
2206
2207 /* ??? Traditionally we've passed TYPE_MODE here, instead of the
2208 promoted_mode used for function_arg above. However, the
2209 corresponding handling of incoming arguments in function.c
2210 does pass the promoted mode. */
2211 function_arg_info arg_to_skip (type, TYPE_MODE (type),
2212 argpos < n_named_args);
2213 targetm.calls.function_arg_advance (args_so_far, arg_to_skip);
2214
2215 /* Store argument values for functions decorated with attribute
2216 alloc_size. */
2217 if (argpos == alloc_idx[0])
2218 alloc_args[0] = args[i].tree_value;
2219 else if (argpos == alloc_idx[1])
2220 alloc_args[1] = args[i].tree_value;
2221 }
2222
2223 if (alloc_args[0])
2224 {
2225 /* Check the arguments of functions decorated with attribute
2226 alloc_size. */
2227 maybe_warn_alloc_args_overflow (fndecl, exp, alloc_args, alloc_idx);
2228 }
2229
2230 /* Detect passing non-string arguments to functions expecting
2231 nul-terminated strings. */
2232 maybe_warn_nonstring_arg (fndecl, exp);
2233 }
2234
2235 /* Update ARGS_SIZE to contain the total size for the argument block.
2236 Return the original constant component of the argument block's size.
2237
2238 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
2239 for arguments passed in registers. */
2240
2241 static poly_int64
2242 compute_argument_block_size (int reg_parm_stack_space,
2243 struct args_size *args_size,
2244 tree fndecl ATTRIBUTE_UNUSED,
2245 tree fntype ATTRIBUTE_UNUSED,
2246 int preferred_stack_boundary ATTRIBUTE_UNUSED)
2247 {
2248 poly_int64 unadjusted_args_size = args_size->constant;
2249
2250 /* For accumulate outgoing args mode we don't need to align, since the frame
2251 will be already aligned. Align to STACK_BOUNDARY in order to prevent
2252 backends from generating misaligned frame sizes. */
2253 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
2254 preferred_stack_boundary = STACK_BOUNDARY;
2255
2256 /* Compute the actual size of the argument block required. The variable
2257 and constant sizes must be combined, the size may have to be rounded,
2258 and there may be a minimum required size. */
2259
2260 if (args_size->var)
2261 {
2262 args_size->var = ARGS_SIZE_TREE (*args_size);
2263 args_size->constant = 0;
2264
2265 preferred_stack_boundary /= BITS_PER_UNIT;
2266 if (preferred_stack_boundary > 1)
2267 {
2268 /* We don't handle this case yet. To handle it correctly we have
2269 to add the delta, round and subtract the delta.
2270 Currently no machine description requires this support. */
2271 gcc_assert (multiple_p (stack_pointer_delta,
2272 preferred_stack_boundary));
2273 args_size->var = round_up (args_size->var, preferred_stack_boundary);
2274 }
2275
2276 if (reg_parm_stack_space > 0)
2277 {
2278 args_size->var
2279 = size_binop (MAX_EXPR, args_size->var,
2280 ssize_int (reg_parm_stack_space));
2281
2282 /* The area corresponding to register parameters is not to count in
2283 the size of the block we need. So make the adjustment. */
2284 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
2285 args_size->var
2286 = size_binop (MINUS_EXPR, args_size->var,
2287 ssize_int (reg_parm_stack_space));
2288 }
2289 }
2290 else
2291 {
2292 preferred_stack_boundary /= BITS_PER_UNIT;
2293 if (preferred_stack_boundary < 1)
2294 preferred_stack_boundary = 1;
2295 args_size->constant = (aligned_upper_bound (args_size->constant
2296 + stack_pointer_delta,
2297 preferred_stack_boundary)
2298 - stack_pointer_delta);
2299
2300 args_size->constant = upper_bound (args_size->constant,
2301 reg_parm_stack_space);
2302
2303 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
2304 args_size->constant -= reg_parm_stack_space;
2305 }
2306 return unadjusted_args_size;
2307 }
2308
2309 /* Precompute parameters as needed for a function call.
2310
2311 FLAGS is mask of ECF_* constants.
2312
2313 NUM_ACTUALS is the number of arguments.
2314
2315 ARGS is an array containing information for each argument; this
2316 routine fills in the INITIAL_VALUE and VALUE fields for each
2317 precomputed argument. */
2318
2319 static void
2320 precompute_arguments (int num_actuals, struct arg_data *args)
2321 {
2322 int i;
2323
2324 /* If this is a libcall, then precompute all arguments so that we do not
2325 get extraneous instructions emitted as part of the libcall sequence. */
2326
2327 /* If we preallocated the stack space, and some arguments must be passed
2328 on the stack, then we must precompute any parameter which contains a
2329 function call which will store arguments on the stack.
2330 Otherwise, evaluating the parameter may clobber previous parameters
2331 which have already been stored into the stack. (we have code to avoid
2332 such case by saving the outgoing stack arguments, but it results in
2333 worse code) */
2334 if (!ACCUMULATE_OUTGOING_ARGS)
2335 return;
2336
2337 for (i = 0; i < num_actuals; i++)
2338 {
2339 tree type;
2340 machine_mode mode;
2341
2342 if (TREE_CODE (args[i].tree_value) != CALL_EXPR)
2343 continue;
2344
2345 /* If this is an addressable type, we cannot pre-evaluate it. */
2346 type = TREE_TYPE (args[i].tree_value);
2347 gcc_assert (!TREE_ADDRESSABLE (type));
2348
2349 args[i].initial_value = args[i].value
2350 = expand_normal (args[i].tree_value);
2351
2352 mode = TYPE_MODE (type);
2353 if (mode != args[i].mode)
2354 {
2355 int unsignedp = args[i].unsignedp;
2356 args[i].value
2357 = convert_modes (args[i].mode, mode,
2358 args[i].value, args[i].unsignedp);
2359
2360 /* CSE will replace this only if it contains args[i].value
2361 pseudo, so convert it down to the declared mode using
2362 a SUBREG. */
2363 if (REG_P (args[i].value)
2364 && GET_MODE_CLASS (args[i].mode) == MODE_INT
2365 && promote_mode (type, mode, &unsignedp) != args[i].mode)
2366 {
2367 args[i].initial_value
2368 = gen_lowpart_SUBREG (mode, args[i].value);
2369 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
2370 SUBREG_PROMOTED_SET (args[i].initial_value, args[i].unsignedp);
2371 }
2372 }
2373 }
2374 }
2375
2376 /* Given the current state of MUST_PREALLOCATE and information about
2377 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
2378 compute and return the final value for MUST_PREALLOCATE. */
2379
2380 static int
2381 finalize_must_preallocate (int must_preallocate, int num_actuals,
2382 struct arg_data *args, struct args_size *args_size)
2383 {
2384 /* See if we have or want to preallocate stack space.
2385
2386 If we would have to push a partially-in-regs parm
2387 before other stack parms, preallocate stack space instead.
2388
2389 If the size of some parm is not a multiple of the required stack
2390 alignment, we must preallocate.
2391
2392 If the total size of arguments that would otherwise create a copy in
2393 a temporary (such as a CALL) is more than half the total argument list
2394 size, preallocation is faster.
2395
2396 Another reason to preallocate is if we have a machine (like the m88k)
2397 where stack alignment is required to be maintained between every
2398 pair of insns, not just when the call is made. However, we assume here
2399 that such machines either do not have push insns (and hence preallocation
2400 would occur anyway) or the problem is taken care of with
2401 PUSH_ROUNDING. */
2402
2403 if (! must_preallocate)
2404 {
2405 int partial_seen = 0;
2406 poly_int64 copy_to_evaluate_size = 0;
2407 int i;
2408
2409 for (i = 0; i < num_actuals && ! must_preallocate; i++)
2410 {
2411 if (args[i].partial > 0 && ! args[i].pass_on_stack)
2412 partial_seen = 1;
2413 else if (partial_seen && args[i].reg == 0)
2414 must_preallocate = 1;
2415
2416 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
2417 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
2418 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
2419 || TREE_CODE (args[i].tree_value) == COND_EXPR
2420 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
2421 copy_to_evaluate_size
2422 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
2423 }
2424
2425 if (maybe_ne (args_size->constant, 0)
2426 && maybe_ge (copy_to_evaluate_size * 2, args_size->constant))
2427 must_preallocate = 1;
2428 }
2429 return must_preallocate;
2430 }
2431
2432 /* If we preallocated stack space, compute the address of each argument
2433 and store it into the ARGS array.
2434
2435 We need not ensure it is a valid memory address here; it will be
2436 validized when it is used.
2437
2438 ARGBLOCK is an rtx for the address of the outgoing arguments. */
2439
2440 static void
2441 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
2442 {
2443 if (argblock)
2444 {
2445 rtx arg_reg = argblock;
2446 int i;
2447 poly_int64 arg_offset = 0;
2448
2449 if (GET_CODE (argblock) == PLUS)
2450 {
2451 arg_reg = XEXP (argblock, 0);
2452 arg_offset = rtx_to_poly_int64 (XEXP (argblock, 1));
2453 }
2454
2455 for (i = 0; i < num_actuals; i++)
2456 {
2457 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
2458 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
2459 rtx addr;
2460 unsigned int align, boundary;
2461 poly_uint64 units_on_stack = 0;
2462 machine_mode partial_mode = VOIDmode;
2463
2464 /* Skip this parm if it will not be passed on the stack. */
2465 if (! args[i].pass_on_stack
2466 && args[i].reg != 0
2467 && args[i].partial == 0)
2468 continue;
2469
2470 if (TYPE_EMPTY_P (TREE_TYPE (args[i].tree_value)))
2471 continue;
2472
2473 addr = simplify_gen_binary (PLUS, Pmode, arg_reg, offset);
2474 addr = plus_constant (Pmode, addr, arg_offset);
2475
2476 if (args[i].partial != 0)
2477 {
2478 /* Only part of the parameter is being passed on the stack.
2479 Generate a simple memory reference of the correct size. */
2480 units_on_stack = args[i].locate.size.constant;
2481 poly_uint64 bits_on_stack = units_on_stack * BITS_PER_UNIT;
2482 partial_mode = int_mode_for_size (bits_on_stack, 1).else_blk ();
2483 args[i].stack = gen_rtx_MEM (partial_mode, addr);
2484 set_mem_size (args[i].stack, units_on_stack);
2485 }
2486 else
2487 {
2488 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
2489 set_mem_attributes (args[i].stack,
2490 TREE_TYPE (args[i].tree_value), 1);
2491 }
2492 align = BITS_PER_UNIT;
2493 boundary = args[i].locate.boundary;
2494 poly_int64 offset_val;
2495 if (args[i].locate.where_pad != PAD_DOWNWARD)
2496 align = boundary;
2497 else if (poly_int_rtx_p (offset, &offset_val))
2498 {
2499 align = least_bit_hwi (boundary);
2500 unsigned int offset_align
2501 = known_alignment (offset_val) * BITS_PER_UNIT;
2502 if (offset_align != 0)
2503 align = MIN (align, offset_align);
2504 }
2505 set_mem_align (args[i].stack, align);
2506
2507 addr = simplify_gen_binary (PLUS, Pmode, arg_reg, slot_offset);
2508 addr = plus_constant (Pmode, addr, arg_offset);
2509
2510 if (args[i].partial != 0)
2511 {
2512 /* Only part of the parameter is being passed on the stack.
2513 Generate a simple memory reference of the correct size.
2514 */
2515 args[i].stack_slot = gen_rtx_MEM (partial_mode, addr);
2516 set_mem_size (args[i].stack_slot, units_on_stack);
2517 }
2518 else
2519 {
2520 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
2521 set_mem_attributes (args[i].stack_slot,
2522 TREE_TYPE (args[i].tree_value), 1);
2523 }
2524 set_mem_align (args[i].stack_slot, args[i].locate.boundary);
2525
2526 /* Function incoming arguments may overlap with sibling call
2527 outgoing arguments and we cannot allow reordering of reads
2528 from function arguments with stores to outgoing arguments
2529 of sibling calls. */
2530 set_mem_alias_set (args[i].stack, 0);
2531 set_mem_alias_set (args[i].stack_slot, 0);
2532 }
2533 }
2534 }
2535
2536 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
2537 in a call instruction.
2538
2539 FNDECL is the tree node for the target function. For an indirect call
2540 FNDECL will be NULL_TREE.
2541
2542 ADDR is the operand 0 of CALL_EXPR for this call. */
2543
2544 static rtx
2545 rtx_for_function_call (tree fndecl, tree addr)
2546 {
2547 rtx funexp;
2548
2549 /* Get the function to call, in the form of RTL. */
2550 if (fndecl)
2551 {
2552 if (!TREE_USED (fndecl) && fndecl != current_function_decl)
2553 TREE_USED (fndecl) = 1;
2554
2555 /* Get a SYMBOL_REF rtx for the function address. */
2556 funexp = XEXP (DECL_RTL (fndecl), 0);
2557 }
2558 else
2559 /* Generate an rtx (probably a pseudo-register) for the address. */
2560 {
2561 push_temp_slots ();
2562 funexp = expand_normal (addr);
2563 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
2564 }
2565 return funexp;
2566 }
2567
2568 /* Return the static chain for this function, if any. */
2569
2570 rtx
2571 rtx_for_static_chain (const_tree fndecl_or_type, bool incoming_p)
2572 {
2573 if (DECL_P (fndecl_or_type) && !DECL_STATIC_CHAIN (fndecl_or_type))
2574 return NULL;
2575
2576 return targetm.calls.static_chain (fndecl_or_type, incoming_p);
2577 }
2578
2579 /* Internal state for internal_arg_pointer_based_exp and its helpers. */
2580 static struct
2581 {
2582 /* Last insn that has been scanned by internal_arg_pointer_based_exp_scan,
2583 or NULL_RTX if none has been scanned yet. */
2584 rtx_insn *scan_start;
2585 /* Vector indexed by REGNO - FIRST_PSEUDO_REGISTER, recording if a pseudo is
2586 based on crtl->args.internal_arg_pointer. The element is NULL_RTX if the
2587 pseudo isn't based on it, a CONST_INT offset if the pseudo is based on it
2588 with fixed offset, or PC if this is with variable or unknown offset. */
2589 vec<rtx> cache;
2590 } internal_arg_pointer_exp_state;
2591
2592 static rtx internal_arg_pointer_based_exp (const_rtx, bool);
2593
2594 /* Helper function for internal_arg_pointer_based_exp. Scan insns in
2595 the tail call sequence, starting with first insn that hasn't been
2596 scanned yet, and note for each pseudo on the LHS whether it is based
2597 on crtl->args.internal_arg_pointer or not, and what offset from that
2598 that pointer it has. */
2599
2600 static void
2601 internal_arg_pointer_based_exp_scan (void)
2602 {
2603 rtx_insn *insn, *scan_start = internal_arg_pointer_exp_state.scan_start;
2604
2605 if (scan_start == NULL_RTX)
2606 insn = get_insns ();
2607 else
2608 insn = NEXT_INSN (scan_start);
2609
2610 while (insn)
2611 {
2612 rtx set = single_set (insn);
2613 if (set && REG_P (SET_DEST (set)) && !HARD_REGISTER_P (SET_DEST (set)))
2614 {
2615 rtx val = NULL_RTX;
2616 unsigned int idx = REGNO (SET_DEST (set)) - FIRST_PSEUDO_REGISTER;
2617 /* Punt on pseudos set multiple times. */
2618 if (idx < internal_arg_pointer_exp_state.cache.length ()
2619 && (internal_arg_pointer_exp_state.cache[idx]
2620 != NULL_RTX))
2621 val = pc_rtx;
2622 else
2623 val = internal_arg_pointer_based_exp (SET_SRC (set), false);
2624 if (val != NULL_RTX)
2625 {
2626 if (idx >= internal_arg_pointer_exp_state.cache.length ())
2627 internal_arg_pointer_exp_state.cache
2628 .safe_grow_cleared (idx + 1);
2629 internal_arg_pointer_exp_state.cache[idx] = val;
2630 }
2631 }
2632 if (NEXT_INSN (insn) == NULL_RTX)
2633 scan_start = insn;
2634 insn = NEXT_INSN (insn);
2635 }
2636
2637 internal_arg_pointer_exp_state.scan_start = scan_start;
2638 }
2639
2640 /* Compute whether RTL is based on crtl->args.internal_arg_pointer. Return
2641 NULL_RTX if RTL isn't based on it, a CONST_INT offset if RTL is based on
2642 it with fixed offset, or PC if this is with variable or unknown offset.
2643 TOPLEVEL is true if the function is invoked at the topmost level. */
2644
2645 static rtx
2646 internal_arg_pointer_based_exp (const_rtx rtl, bool toplevel)
2647 {
2648 if (CONSTANT_P (rtl))
2649 return NULL_RTX;
2650
2651 if (rtl == crtl->args.internal_arg_pointer)
2652 return const0_rtx;
2653
2654 if (REG_P (rtl) && HARD_REGISTER_P (rtl))
2655 return NULL_RTX;
2656
2657 poly_int64 offset;
2658 if (GET_CODE (rtl) == PLUS && poly_int_rtx_p (XEXP (rtl, 1), &offset))
2659 {
2660 rtx val = internal_arg_pointer_based_exp (XEXP (rtl, 0), toplevel);
2661 if (val == NULL_RTX || val == pc_rtx)
2662 return val;
2663 return plus_constant (Pmode, val, offset);
2664 }
2665
2666 /* When called at the topmost level, scan pseudo assignments in between the
2667 last scanned instruction in the tail call sequence and the latest insn
2668 in that sequence. */
2669 if (toplevel)
2670 internal_arg_pointer_based_exp_scan ();
2671
2672 if (REG_P (rtl))
2673 {
2674 unsigned int idx = REGNO (rtl) - FIRST_PSEUDO_REGISTER;
2675 if (idx < internal_arg_pointer_exp_state.cache.length ())
2676 return internal_arg_pointer_exp_state.cache[idx];
2677
2678 return NULL_RTX;
2679 }
2680
2681 subrtx_iterator::array_type array;
2682 FOR_EACH_SUBRTX (iter, array, rtl, NONCONST)
2683 {
2684 const_rtx x = *iter;
2685 if (REG_P (x) && internal_arg_pointer_based_exp (x, false) != NULL_RTX)
2686 return pc_rtx;
2687 if (MEM_P (x))
2688 iter.skip_subrtxes ();
2689 }
2690
2691 return NULL_RTX;
2692 }
2693
2694 /* Return true if SIZE bytes starting from address ADDR might overlap an
2695 already-clobbered argument area. This function is used to determine
2696 if we should give up a sibcall. */
2697
2698 static bool
2699 mem_might_overlap_already_clobbered_arg_p (rtx addr, poly_uint64 size)
2700 {
2701 poly_int64 i;
2702 unsigned HOST_WIDE_INT start, end;
2703 rtx val;
2704
2705 if (bitmap_empty_p (stored_args_map)
2706 && stored_args_watermark == HOST_WIDE_INT_M1U)
2707 return false;
2708 val = internal_arg_pointer_based_exp (addr, true);
2709 if (val == NULL_RTX)
2710 return false;
2711 else if (!poly_int_rtx_p (val, &i))
2712 return true;
2713
2714 if (known_eq (size, 0U))
2715 return false;
2716
2717 if (STACK_GROWS_DOWNWARD)
2718 i -= crtl->args.pretend_args_size;
2719 else
2720 i += crtl->args.pretend_args_size;
2721
2722 if (ARGS_GROW_DOWNWARD)
2723 i = -i - size;
2724
2725 /* We can ignore any references to the function's pretend args,
2726 which at this point would manifest as negative values of I. */
2727 if (known_le (i, 0) && known_le (size, poly_uint64 (-i)))
2728 return false;
2729
2730 start = maybe_lt (i, 0) ? 0 : constant_lower_bound (i);
2731 if (!(i + size).is_constant (&end))
2732 end = HOST_WIDE_INT_M1U;
2733
2734 if (end > stored_args_watermark)
2735 return true;
2736
2737 end = MIN (end, SBITMAP_SIZE (stored_args_map));
2738 for (unsigned HOST_WIDE_INT k = start; k < end; ++k)
2739 if (bitmap_bit_p (stored_args_map, k))
2740 return true;
2741
2742 return false;
2743 }
2744
2745 /* Do the register loads required for any wholly-register parms or any
2746 parms which are passed both on the stack and in a register. Their
2747 expressions were already evaluated.
2748
2749 Mark all register-parms as living through the call, putting these USE
2750 insns in the CALL_INSN_FUNCTION_USAGE field.
2751
2752 When IS_SIBCALL, perform the check_sibcall_argument_overlap
2753 checking, setting *SIBCALL_FAILURE if appropriate. */
2754
2755 static void
2756 load_register_parameters (struct arg_data *args, int num_actuals,
2757 rtx *call_fusage, int flags, int is_sibcall,
2758 int *sibcall_failure)
2759 {
2760 int i, j;
2761
2762 for (i = 0; i < num_actuals; i++)
2763 {
2764 rtx reg = ((flags & ECF_SIBCALL)
2765 ? args[i].tail_call_reg : args[i].reg);
2766 if (reg)
2767 {
2768 int partial = args[i].partial;
2769 int nregs;
2770 poly_int64 size = 0;
2771 HOST_WIDE_INT const_size = 0;
2772 rtx_insn *before_arg = get_last_insn ();
2773 /* Set non-negative if we must move a word at a time, even if
2774 just one word (e.g, partial == 4 && mode == DFmode). Set
2775 to -1 if we just use a normal move insn. This value can be
2776 zero if the argument is a zero size structure. */
2777 nregs = -1;
2778 if (GET_CODE (reg) == PARALLEL)
2779 ;
2780 else if (partial)
2781 {
2782 gcc_assert (partial % UNITS_PER_WORD == 0);
2783 nregs = partial / UNITS_PER_WORD;
2784 }
2785 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
2786 {
2787 /* Variable-sized parameters should be described by a
2788 PARALLEL instead. */
2789 const_size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
2790 gcc_assert (const_size >= 0);
2791 nregs = (const_size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
2792 size = const_size;
2793 }
2794 else
2795 size = GET_MODE_SIZE (args[i].mode);
2796
2797 /* Handle calls that pass values in multiple non-contiguous
2798 locations. The Irix 6 ABI has examples of this. */
2799
2800 if (GET_CODE (reg) == PARALLEL)
2801 emit_group_move (reg, args[i].parallel_value);
2802
2803 /* If simple case, just do move. If normal partial, store_one_arg
2804 has already loaded the register for us. In all other cases,
2805 load the register(s) from memory. */
2806
2807 else if (nregs == -1)
2808 {
2809 emit_move_insn (reg, args[i].value);
2810 #ifdef BLOCK_REG_PADDING
2811 /* Handle case where we have a value that needs shifting
2812 up to the msb. eg. a QImode value and we're padding
2813 upward on a BYTES_BIG_ENDIAN machine. */
2814 if (args[i].locate.where_pad
2815 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD))
2816 {
2817 gcc_checking_assert (ordered_p (size, UNITS_PER_WORD));
2818 if (maybe_lt (size, UNITS_PER_WORD))
2819 {
2820 rtx x;
2821 poly_int64 shift
2822 = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
2823
2824 /* Assigning REG here rather than a temp makes
2825 CALL_FUSAGE report the whole reg as used.
2826 Strictly speaking, the call only uses SIZE
2827 bytes at the msb end, but it doesn't seem worth
2828 generating rtl to say that. */
2829 reg = gen_rtx_REG (word_mode, REGNO (reg));
2830 x = expand_shift (LSHIFT_EXPR, word_mode,
2831 reg, shift, reg, 1);
2832 if (x != reg)
2833 emit_move_insn (reg, x);
2834 }
2835 }
2836 #endif
2837 }
2838
2839 /* If we have pre-computed the values to put in the registers in
2840 the case of non-aligned structures, copy them in now. */
2841
2842 else if (args[i].n_aligned_regs != 0)
2843 for (j = 0; j < args[i].n_aligned_regs; j++)
2844 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
2845 args[i].aligned_regs[j]);
2846
2847 else if (partial == 0 || args[i].pass_on_stack)
2848 {
2849 /* SIZE and CONST_SIZE are 0 for partial arguments and
2850 the size of a BLKmode type otherwise. */
2851 gcc_checking_assert (known_eq (size, const_size));
2852 rtx mem = validize_mem (copy_rtx (args[i].value));
2853
2854 /* Check for overlap with already clobbered argument area,
2855 providing that this has non-zero size. */
2856 if (is_sibcall
2857 && const_size != 0
2858 && (mem_might_overlap_already_clobbered_arg_p
2859 (XEXP (args[i].value, 0), const_size)))
2860 *sibcall_failure = 1;
2861
2862 if (const_size % UNITS_PER_WORD == 0
2863 || MEM_ALIGN (mem) % BITS_PER_WORD == 0)
2864 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
2865 else
2866 {
2867 if (nregs > 1)
2868 move_block_to_reg (REGNO (reg), mem, nregs - 1,
2869 args[i].mode);
2870 rtx dest = gen_rtx_REG (word_mode, REGNO (reg) + nregs - 1);
2871 unsigned int bitoff = (nregs - 1) * BITS_PER_WORD;
2872 unsigned int bitsize = const_size * BITS_PER_UNIT - bitoff;
2873 rtx x = extract_bit_field (mem, bitsize, bitoff, 1, dest,
2874 word_mode, word_mode, false,
2875 NULL);
2876 if (BYTES_BIG_ENDIAN)
2877 x = expand_shift (LSHIFT_EXPR, word_mode, x,
2878 BITS_PER_WORD - bitsize, dest, 1);
2879 if (x != dest)
2880 emit_move_insn (dest, x);
2881 }
2882
2883 /* Handle a BLKmode that needs shifting. */
2884 if (nregs == 1 && const_size < UNITS_PER_WORD
2885 #ifdef BLOCK_REG_PADDING
2886 && args[i].locate.where_pad == PAD_DOWNWARD
2887 #else
2888 && BYTES_BIG_ENDIAN
2889 #endif
2890 )
2891 {
2892 rtx dest = gen_rtx_REG (word_mode, REGNO (reg));
2893 int shift = (UNITS_PER_WORD - const_size) * BITS_PER_UNIT;
2894 enum tree_code dir = (BYTES_BIG_ENDIAN
2895 ? RSHIFT_EXPR : LSHIFT_EXPR);
2896 rtx x;
2897
2898 x = expand_shift (dir, word_mode, dest, shift, dest, 1);
2899 if (x != dest)
2900 emit_move_insn (dest, x);
2901 }
2902 }
2903
2904 /* When a parameter is a block, and perhaps in other cases, it is
2905 possible that it did a load from an argument slot that was
2906 already clobbered. */
2907 if (is_sibcall
2908 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
2909 *sibcall_failure = 1;
2910
2911 /* Handle calls that pass values in multiple non-contiguous
2912 locations. The Irix 6 ABI has examples of this. */
2913 if (GET_CODE (reg) == PARALLEL)
2914 use_group_regs (call_fusage, reg);
2915 else if (nregs == -1)
2916 use_reg_mode (call_fusage, reg,
2917 TYPE_MODE (TREE_TYPE (args[i].tree_value)));
2918 else if (nregs > 0)
2919 use_regs (call_fusage, REGNO (reg), nregs);
2920 }
2921 }
2922 }
2923
2924 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
2925 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
2926 bytes, then we would need to push some additional bytes to pad the
2927 arguments. So, we try to compute an adjust to the stack pointer for an
2928 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
2929 bytes. Then, when the arguments are pushed the stack will be perfectly
2930 aligned.
2931
2932 Return true if this optimization is possible, storing the adjustment
2933 in ADJUSTMENT_OUT and setting ARGS_SIZE->CONSTANT to the number of
2934 bytes that should be popped after the call. */
2935
2936 static bool
2937 combine_pending_stack_adjustment_and_call (poly_int64_pod *adjustment_out,
2938 poly_int64 unadjusted_args_size,
2939 struct args_size *args_size,
2940 unsigned int preferred_unit_stack_boundary)
2941 {
2942 /* The number of bytes to pop so that the stack will be
2943 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
2944 poly_int64 adjustment;
2945 /* The alignment of the stack after the arguments are pushed, if we
2946 just pushed the arguments without adjust the stack here. */
2947 unsigned HOST_WIDE_INT unadjusted_alignment;
2948
2949 if (!known_misalignment (stack_pointer_delta + unadjusted_args_size,
2950 preferred_unit_stack_boundary,
2951 &unadjusted_alignment))
2952 return false;
2953
2954 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
2955 as possible -- leaving just enough left to cancel out the
2956 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
2957 PENDING_STACK_ADJUST is non-negative, and congruent to
2958 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
2959
2960 /* Begin by trying to pop all the bytes. */
2961 unsigned HOST_WIDE_INT tmp_misalignment;
2962 if (!known_misalignment (pending_stack_adjust,
2963 preferred_unit_stack_boundary,
2964 &tmp_misalignment))
2965 return false;
2966 unadjusted_alignment -= tmp_misalignment;
2967 adjustment = pending_stack_adjust;
2968 /* Push enough additional bytes that the stack will be aligned
2969 after the arguments are pushed. */
2970 if (preferred_unit_stack_boundary > 1 && unadjusted_alignment)
2971 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
2972
2973 /* We need to know whether the adjusted argument size
2974 (UNADJUSTED_ARGS_SIZE - ADJUSTMENT) constitutes an allocation
2975 or a deallocation. */
2976 if (!ordered_p (adjustment, unadjusted_args_size))
2977 return false;
2978
2979 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
2980 bytes after the call. The right number is the entire
2981 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
2982 by the arguments in the first place. */
2983 args_size->constant
2984 = pending_stack_adjust - adjustment + unadjusted_args_size;
2985
2986 *adjustment_out = adjustment;
2987 return true;
2988 }
2989
2990 /* Scan X expression if it does not dereference any argument slots
2991 we already clobbered by tail call arguments (as noted in stored_args_map
2992 bitmap).
2993 Return nonzero if X expression dereferences such argument slots,
2994 zero otherwise. */
2995
2996 static int
2997 check_sibcall_argument_overlap_1 (rtx x)
2998 {
2999 RTX_CODE code;
3000 int i, j;
3001 const char *fmt;
3002
3003 if (x == NULL_RTX)
3004 return 0;
3005
3006 code = GET_CODE (x);
3007
3008 /* We need not check the operands of the CALL expression itself. */
3009 if (code == CALL)
3010 return 0;
3011
3012 if (code == MEM)
3013 return (mem_might_overlap_already_clobbered_arg_p
3014 (XEXP (x, 0), GET_MODE_SIZE (GET_MODE (x))));
3015
3016 /* Scan all subexpressions. */
3017 fmt = GET_RTX_FORMAT (code);
3018 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
3019 {
3020 if (*fmt == 'e')
3021 {
3022 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
3023 return 1;
3024 }
3025 else if (*fmt == 'E')
3026 {
3027 for (j = 0; j < XVECLEN (x, i); j++)
3028 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
3029 return 1;
3030 }
3031 }
3032 return 0;
3033 }
3034
3035 /* Scan sequence after INSN if it does not dereference any argument slots
3036 we already clobbered by tail call arguments (as noted in stored_args_map
3037 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
3038 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
3039 should be 0). Return nonzero if sequence after INSN dereferences such argument
3040 slots, zero otherwise. */
3041
3042 static int
3043 check_sibcall_argument_overlap (rtx_insn *insn, struct arg_data *arg,
3044 int mark_stored_args_map)
3045 {
3046 poly_uint64 low, high;
3047 unsigned HOST_WIDE_INT const_low, const_high;
3048
3049 if (insn == NULL_RTX)
3050 insn = get_insns ();
3051 else
3052 insn = NEXT_INSN (insn);
3053
3054 for (; insn; insn = NEXT_INSN (insn))
3055 if (INSN_P (insn)
3056 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
3057 break;
3058
3059 if (mark_stored_args_map)
3060 {
3061 if (ARGS_GROW_DOWNWARD)
3062 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
3063 else
3064 low = arg->locate.slot_offset.constant;
3065 high = low + arg->locate.size.constant;
3066
3067 const_low = constant_lower_bound (low);
3068 if (high.is_constant (&const_high))
3069 for (unsigned HOST_WIDE_INT i = const_low; i < const_high; ++i)
3070 bitmap_set_bit (stored_args_map, i);
3071 else
3072 stored_args_watermark = MIN (stored_args_watermark, const_low);
3073 }
3074 return insn != NULL_RTX;
3075 }
3076
3077 /* Given that a function returns a value of mode MODE at the most
3078 significant end of hard register VALUE, shift VALUE left or right
3079 as specified by LEFT_P. Return true if some action was needed. */
3080
3081 bool
3082 shift_return_value (machine_mode mode, bool left_p, rtx value)
3083 {
3084 gcc_assert (REG_P (value) && HARD_REGISTER_P (value));
3085 machine_mode value_mode = GET_MODE (value);
3086 poly_int64 shift = GET_MODE_BITSIZE (value_mode) - GET_MODE_BITSIZE (mode);
3087
3088 if (known_eq (shift, 0))
3089 return false;
3090
3091 /* Use ashr rather than lshr for right shifts. This is for the benefit
3092 of the MIPS port, which requires SImode values to be sign-extended
3093 when stored in 64-bit registers. */
3094 if (!force_expand_binop (value_mode, left_p ? ashl_optab : ashr_optab,
3095 value, gen_int_shift_amount (value_mode, shift),
3096 value, 1, OPTAB_WIDEN))
3097 gcc_unreachable ();
3098 return true;
3099 }
3100
3101 /* If X is a likely-spilled register value, copy it to a pseudo
3102 register and return that register. Return X otherwise. */
3103
3104 static rtx
3105 avoid_likely_spilled_reg (rtx x)
3106 {
3107 rtx new_rtx;
3108
3109 if (REG_P (x)
3110 && HARD_REGISTER_P (x)
3111 && targetm.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (x))))
3112 {
3113 /* Make sure that we generate a REG rather than a CONCAT.
3114 Moves into CONCATs can need nontrivial instructions,
3115 and the whole point of this function is to avoid
3116 using the hard register directly in such a situation. */
3117 generating_concat_p = 0;
3118 new_rtx = gen_reg_rtx (GET_MODE (x));
3119 generating_concat_p = 1;
3120 emit_move_insn (new_rtx, x);
3121 return new_rtx;
3122 }
3123 return x;
3124 }
3125
3126 /* Helper function for expand_call.
3127 Return false is EXP is not implementable as a sibling call. */
3128
3129 static bool
3130 can_implement_as_sibling_call_p (tree exp,
3131 rtx structure_value_addr,
3132 tree funtype,
3133 int reg_parm_stack_space ATTRIBUTE_UNUSED,
3134 tree fndecl,
3135 int flags,
3136 tree addr,
3137 const args_size &args_size)
3138 {
3139 if (!targetm.have_sibcall_epilogue ())
3140 {
3141 maybe_complain_about_tail_call
3142 (exp,
3143 "machine description does not have"
3144 " a sibcall_epilogue instruction pattern");
3145 return false;
3146 }
3147
3148 /* Doing sibling call optimization needs some work, since
3149 structure_value_addr can be allocated on the stack.
3150 It does not seem worth the effort since few optimizable
3151 sibling calls will return a structure. */
3152 if (structure_value_addr != NULL_RTX)
3153 {
3154 maybe_complain_about_tail_call (exp, "callee returns a structure");
3155 return false;
3156 }
3157
3158 #ifdef REG_PARM_STACK_SPACE
3159 /* If outgoing reg parm stack space changes, we cannot do sibcall. */
3160 if (OUTGOING_REG_PARM_STACK_SPACE (funtype)
3161 != OUTGOING_REG_PARM_STACK_SPACE (TREE_TYPE (current_function_decl))
3162 || (reg_parm_stack_space != REG_PARM_STACK_SPACE (current_function_decl)))
3163 {
3164 maybe_complain_about_tail_call (exp,
3165 "inconsistent size of stack space"
3166 " allocated for arguments which are"
3167 " passed in registers");
3168 return false;
3169 }
3170 #endif
3171
3172 /* Check whether the target is able to optimize the call
3173 into a sibcall. */
3174 if (!targetm.function_ok_for_sibcall (fndecl, exp))
3175 {
3176 maybe_complain_about_tail_call (exp,
3177 "target is not able to optimize the"
3178 " call into a sibling call");
3179 return false;
3180 }
3181
3182 /* Functions that do not return exactly once may not be sibcall
3183 optimized. */
3184 if (flags & ECF_RETURNS_TWICE)
3185 {
3186 maybe_complain_about_tail_call (exp, "callee returns twice");
3187 return false;
3188 }
3189 if (flags & ECF_NORETURN)
3190 {
3191 maybe_complain_about_tail_call (exp, "callee does not return");
3192 return false;
3193 }
3194
3195 if (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr))))
3196 {
3197 maybe_complain_about_tail_call (exp, "volatile function type");
3198 return false;
3199 }
3200
3201 /* If the called function is nested in the current one, it might access
3202 some of the caller's arguments, but could clobber them beforehand if
3203 the argument areas are shared. */
3204 if (fndecl && decl_function_context (fndecl) == current_function_decl)
3205 {
3206 maybe_complain_about_tail_call (exp, "nested function");
3207 return false;
3208 }
3209
3210 /* If this function requires more stack slots than the current
3211 function, we cannot change it into a sibling call.
3212 crtl->args.pretend_args_size is not part of the
3213 stack allocated by our caller. */
3214 if (maybe_gt (args_size.constant,
3215 crtl->args.size - crtl->args.pretend_args_size))
3216 {
3217 maybe_complain_about_tail_call (exp,
3218 "callee required more stack slots"
3219 " than the caller");
3220 return false;
3221 }
3222
3223 /* If the callee pops its own arguments, then it must pop exactly
3224 the same number of arguments as the current function. */
3225 if (maybe_ne (targetm.calls.return_pops_args (fndecl, funtype,
3226 args_size.constant),
3227 targetm.calls.return_pops_args (current_function_decl,
3228 TREE_TYPE
3229 (current_function_decl),
3230 crtl->args.size)))
3231 {
3232 maybe_complain_about_tail_call (exp,
3233 "inconsistent number of"
3234 " popped arguments");
3235 return false;
3236 }
3237
3238 if (!lang_hooks.decls.ok_for_sibcall (fndecl))
3239 {
3240 maybe_complain_about_tail_call (exp, "frontend does not support"
3241 " sibling call");
3242 return false;
3243 }
3244
3245 /* All checks passed. */
3246 return true;
3247 }
3248
3249 /* Update stack alignment when the parameter is passed in the stack
3250 since the outgoing parameter requires extra alignment on the calling
3251 function side. */
3252
3253 static void
3254 update_stack_alignment_for_call (struct locate_and_pad_arg_data *locate)
3255 {
3256 if (crtl->stack_alignment_needed < locate->boundary)
3257 crtl->stack_alignment_needed = locate->boundary;
3258 if (crtl->preferred_stack_boundary < locate->boundary)
3259 crtl->preferred_stack_boundary = locate->boundary;
3260 }
3261
3262 /* Generate all the code for a CALL_EXPR exp
3263 and return an rtx for its value.
3264 Store the value in TARGET (specified as an rtx) if convenient.
3265 If the value is stored in TARGET then TARGET is returned.
3266 If IGNORE is nonzero, then we ignore the value of the function call. */
3267
3268 rtx
3269 expand_call (tree exp, rtx target, int ignore)
3270 {
3271 /* Nonzero if we are currently expanding a call. */
3272 static int currently_expanding_call = 0;
3273
3274 /* RTX for the function to be called. */
3275 rtx funexp;
3276 /* Sequence of insns to perform a normal "call". */
3277 rtx_insn *normal_call_insns = NULL;
3278 /* Sequence of insns to perform a tail "call". */
3279 rtx_insn *tail_call_insns = NULL;
3280 /* Data type of the function. */
3281 tree funtype;
3282 tree type_arg_types;
3283 tree rettype;
3284 /* Declaration of the function being called,
3285 or 0 if the function is computed (not known by name). */
3286 tree fndecl = 0;
3287 /* The type of the function being called. */
3288 tree fntype;
3289 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
3290 bool must_tail_call = CALL_EXPR_MUST_TAIL_CALL (exp);
3291 int pass;
3292
3293 /* Register in which non-BLKmode value will be returned,
3294 or 0 if no value or if value is BLKmode. */
3295 rtx valreg;
3296 /* Address where we should return a BLKmode value;
3297 0 if value not BLKmode. */
3298 rtx structure_value_addr = 0;
3299 /* Nonzero if that address is being passed by treating it as
3300 an extra, implicit first parameter. Otherwise,
3301 it is passed by being copied directly into struct_value_rtx. */
3302 int structure_value_addr_parm = 0;
3303 /* Holds the value of implicit argument for the struct value. */
3304 tree structure_value_addr_value = NULL_TREE;
3305 /* Size of aggregate value wanted, or zero if none wanted
3306 or if we are using the non-reentrant PCC calling convention
3307 or expecting the value in registers. */
3308 poly_int64 struct_value_size = 0;
3309 /* Nonzero if called function returns an aggregate in memory PCC style,
3310 by returning the address of where to find it. */
3311 int pcc_struct_value = 0;
3312 rtx struct_value = 0;
3313
3314 /* Number of actual parameters in this call, including struct value addr. */
3315 int num_actuals;
3316 /* Number of named args. Args after this are anonymous ones
3317 and they must all go on the stack. */
3318 int n_named_args;
3319 /* Number of complex actual arguments that need to be split. */
3320 int num_complex_actuals = 0;
3321
3322 /* Vector of information about each argument.
3323 Arguments are numbered in the order they will be pushed,
3324 not the order they are written. */
3325 struct arg_data *args;
3326
3327 /* Total size in bytes of all the stack-parms scanned so far. */
3328 struct args_size args_size;
3329 struct args_size adjusted_args_size;
3330 /* Size of arguments before any adjustments (such as rounding). */
3331 poly_int64 unadjusted_args_size;
3332 /* Data on reg parms scanned so far. */
3333 CUMULATIVE_ARGS args_so_far_v;
3334 cumulative_args_t args_so_far;
3335 /* Nonzero if a reg parm has been scanned. */
3336 int reg_parm_seen;
3337 /* Nonzero if this is an indirect function call. */
3338
3339 /* Nonzero if we must avoid push-insns in the args for this call.
3340 If stack space is allocated for register parameters, but not by the
3341 caller, then it is preallocated in the fixed part of the stack frame.
3342 So the entire argument block must then be preallocated (i.e., we
3343 ignore PUSH_ROUNDING in that case). */
3344
3345 int must_preallocate = !PUSH_ARGS;
3346
3347 /* Size of the stack reserved for parameter registers. */
3348 int reg_parm_stack_space = 0;
3349
3350 /* Address of space preallocated for stack parms
3351 (on machines that lack push insns), or 0 if space not preallocated. */
3352 rtx argblock = 0;
3353
3354 /* Mask of ECF_ and ERF_ flags. */
3355 int flags = 0;
3356 int return_flags = 0;
3357 #ifdef REG_PARM_STACK_SPACE
3358 /* Define the boundary of the register parm stack space that needs to be
3359 saved, if any. */
3360 int low_to_save, high_to_save;
3361 rtx save_area = 0; /* Place that it is saved */
3362 #endif
3363
3364 unsigned int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3365 char *initial_stack_usage_map = stack_usage_map;
3366 unsigned HOST_WIDE_INT initial_stack_usage_watermark = stack_usage_watermark;
3367 char *stack_usage_map_buf = NULL;
3368
3369 poly_int64 old_stack_allocated;
3370
3371 /* State variables to track stack modifications. */
3372 rtx old_stack_level = 0;
3373 int old_stack_arg_under_construction = 0;
3374 poly_int64 old_pending_adj = 0;
3375 int old_inhibit_defer_pop = inhibit_defer_pop;
3376
3377 /* Some stack pointer alterations we make are performed via
3378 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
3379 which we then also need to save/restore along the way. */
3380 poly_int64 old_stack_pointer_delta = 0;
3381
3382 rtx call_fusage;
3383 tree addr = CALL_EXPR_FN (exp);
3384 int i;
3385 /* The alignment of the stack, in bits. */
3386 unsigned HOST_WIDE_INT preferred_stack_boundary;
3387 /* The alignment of the stack, in bytes. */
3388 unsigned HOST_WIDE_INT preferred_unit_stack_boundary;
3389 /* The static chain value to use for this call. */
3390 rtx static_chain_value;
3391 /* See if this is "nothrow" function call. */
3392 if (TREE_NOTHROW (exp))
3393 flags |= ECF_NOTHROW;
3394
3395 /* See if we can find a DECL-node for the actual function, and get the
3396 function attributes (flags) from the function decl or type node. */
3397 fndecl = get_callee_fndecl (exp);
3398 if (fndecl)
3399 {
3400 fntype = TREE_TYPE (fndecl);
3401 flags |= flags_from_decl_or_type (fndecl);
3402 return_flags |= decl_return_flags (fndecl);
3403 }
3404 else
3405 {
3406 fntype = TREE_TYPE (TREE_TYPE (addr));
3407 flags |= flags_from_decl_or_type (fntype);
3408 if (CALL_EXPR_BY_DESCRIPTOR (exp))
3409 flags |= ECF_BY_DESCRIPTOR;
3410 }
3411 rettype = TREE_TYPE (exp);
3412
3413 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
3414
3415 /* Warn if this value is an aggregate type,
3416 regardless of which calling convention we are using for it. */
3417 if (AGGREGATE_TYPE_P (rettype))
3418 warning (OPT_Waggregate_return, "function call has aggregate value");
3419
3420 /* If the result of a non looping pure or const function call is
3421 ignored (or void), and none of its arguments are volatile, we can
3422 avoid expanding the call and just evaluate the arguments for
3423 side-effects. */
3424 if ((flags & (ECF_CONST | ECF_PURE))
3425 && (!(flags & ECF_LOOPING_CONST_OR_PURE))
3426 && (ignore || target == const0_rtx
3427 || TYPE_MODE (rettype) == VOIDmode))
3428 {
3429 bool volatilep = false;
3430 tree arg;
3431 call_expr_arg_iterator iter;
3432
3433 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
3434 if (TREE_THIS_VOLATILE (arg))
3435 {
3436 volatilep = true;
3437 break;
3438 }
3439
3440 if (! volatilep)
3441 {
3442 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
3443 expand_expr (arg, const0_rtx, VOIDmode, EXPAND_NORMAL);
3444 return const0_rtx;
3445 }
3446 }
3447
3448 #ifdef REG_PARM_STACK_SPACE
3449 reg_parm_stack_space = REG_PARM_STACK_SPACE (!fndecl ? fntype : fndecl);
3450 #endif
3451
3452 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
3453 && reg_parm_stack_space > 0 && PUSH_ARGS)
3454 must_preallocate = 1;
3455
3456 /* Set up a place to return a structure. */
3457
3458 /* Cater to broken compilers. */
3459 if (aggregate_value_p (exp, fntype))
3460 {
3461 /* This call returns a big structure. */
3462 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
3463
3464 #ifdef PCC_STATIC_STRUCT_RETURN
3465 {
3466 pcc_struct_value = 1;
3467 }
3468 #else /* not PCC_STATIC_STRUCT_RETURN */
3469 {
3470 if (!poly_int_tree_p (TYPE_SIZE_UNIT (rettype), &struct_value_size))
3471 struct_value_size = -1;
3472
3473 /* Even if it is semantically safe to use the target as the return
3474 slot, it may be not sufficiently aligned for the return type. */
3475 if (CALL_EXPR_RETURN_SLOT_OPT (exp)
3476 && target
3477 && MEM_P (target)
3478 /* If rettype is addressable, we may not create a temporary.
3479 If target is properly aligned at runtime and the compiler
3480 just doesn't know about it, it will work fine, otherwise it
3481 will be UB. */
3482 && (TREE_ADDRESSABLE (rettype)
3483 || !(MEM_ALIGN (target) < TYPE_ALIGN (rettype)
3484 && targetm.slow_unaligned_access (TYPE_MODE (rettype),
3485 MEM_ALIGN (target)))))
3486 structure_value_addr = XEXP (target, 0);
3487 else
3488 {
3489 /* For variable-sized objects, we must be called with a target
3490 specified. If we were to allocate space on the stack here,
3491 we would have no way of knowing when to free it. */
3492 rtx d = assign_temp (rettype, 1, 1);
3493 structure_value_addr = XEXP (d, 0);
3494 target = 0;
3495 }
3496 }
3497 #endif /* not PCC_STATIC_STRUCT_RETURN */
3498 }
3499
3500 /* Figure out the amount to which the stack should be aligned. */
3501 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3502 if (fndecl)
3503 {
3504 struct cgraph_rtl_info *i = cgraph_node::rtl_info (fndecl);
3505 /* Without automatic stack alignment, we can't increase preferred
3506 stack boundary. With automatic stack alignment, it is
3507 unnecessary since unless we can guarantee that all callers will
3508 align the outgoing stack properly, callee has to align its
3509 stack anyway. */
3510 if (i
3511 && i->preferred_incoming_stack_boundary
3512 && i->preferred_incoming_stack_boundary < preferred_stack_boundary)
3513 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
3514 }
3515
3516 /* Operand 0 is a pointer-to-function; get the type of the function. */
3517 funtype = TREE_TYPE (addr);
3518 gcc_assert (POINTER_TYPE_P (funtype));
3519 funtype = TREE_TYPE (funtype);
3520
3521 /* Count whether there are actual complex arguments that need to be split
3522 into their real and imaginary parts. Munge the type_arg_types
3523 appropriately here as well. */
3524 if (targetm.calls.split_complex_arg)
3525 {
3526 call_expr_arg_iterator iter;
3527 tree arg;
3528 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
3529 {
3530 tree type = TREE_TYPE (arg);
3531 if (type && TREE_CODE (type) == COMPLEX_TYPE
3532 && targetm.calls.split_complex_arg (type))
3533 num_complex_actuals++;
3534 }
3535 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
3536 }
3537 else
3538 type_arg_types = TYPE_ARG_TYPES (funtype);
3539
3540 if (flags & ECF_MAY_BE_ALLOCA)
3541 cfun->calls_alloca = 1;
3542
3543 /* If struct_value_rtx is 0, it means pass the address
3544 as if it were an extra parameter. Put the argument expression
3545 in structure_value_addr_value. */
3546 if (structure_value_addr && struct_value == 0)
3547 {
3548 /* If structure_value_addr is a REG other than
3549 virtual_outgoing_args_rtx, we can use always use it. If it
3550 is not a REG, we must always copy it into a register.
3551 If it is virtual_outgoing_args_rtx, we must copy it to another
3552 register in some cases. */
3553 rtx temp = (!REG_P (structure_value_addr)
3554 || (ACCUMULATE_OUTGOING_ARGS
3555 && stack_arg_under_construction
3556 && structure_value_addr == virtual_outgoing_args_rtx)
3557 ? copy_addr_to_reg (convert_memory_address
3558 (Pmode, structure_value_addr))
3559 : structure_value_addr);
3560
3561 structure_value_addr_value =
3562 make_tree (build_pointer_type (TREE_TYPE (funtype)), temp);
3563 structure_value_addr_parm = 1;
3564 }
3565
3566 /* Count the arguments and set NUM_ACTUALS. */
3567 num_actuals =
3568 call_expr_nargs (exp) + num_complex_actuals + structure_value_addr_parm;
3569
3570 /* Compute number of named args.
3571 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
3572
3573 if (type_arg_types != 0)
3574 n_named_args
3575 = (list_length (type_arg_types)
3576 /* Count the struct value address, if it is passed as a parm. */
3577 + structure_value_addr_parm);
3578 else
3579 /* If we know nothing, treat all args as named. */
3580 n_named_args = num_actuals;
3581
3582 /* Start updating where the next arg would go.
3583
3584 On some machines (such as the PA) indirect calls have a different
3585 calling convention than normal calls. The fourth argument in
3586 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
3587 or not. */
3588 INIT_CUMULATIVE_ARGS (args_so_far_v, funtype, NULL_RTX, fndecl, n_named_args);
3589 args_so_far = pack_cumulative_args (&args_so_far_v);
3590
3591 /* Now possibly adjust the number of named args.
3592 Normally, don't include the last named arg if anonymous args follow.
3593 We do include the last named arg if
3594 targetm.calls.strict_argument_naming() returns nonzero.
3595 (If no anonymous args follow, the result of list_length is actually
3596 one too large. This is harmless.)
3597
3598 If targetm.calls.pretend_outgoing_varargs_named() returns
3599 nonzero, and targetm.calls.strict_argument_naming() returns zero,
3600 this machine will be able to place unnamed args that were passed
3601 in registers into the stack. So treat all args as named. This
3602 allows the insns emitting for a specific argument list to be
3603 independent of the function declaration.
3604
3605 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
3606 we do not have any reliable way to pass unnamed args in
3607 registers, so we must force them into memory. */
3608
3609 if (type_arg_types != 0
3610 && targetm.calls.strict_argument_naming (args_so_far))
3611 ;
3612 else if (type_arg_types != 0
3613 && ! targetm.calls.pretend_outgoing_varargs_named (args_so_far))
3614 /* Don't include the last named arg. */
3615 --n_named_args;
3616 else
3617 /* Treat all args as named. */
3618 n_named_args = num_actuals;
3619
3620 /* Make a vector to hold all the information about each arg. */
3621 args = XCNEWVEC (struct arg_data, num_actuals);
3622
3623 /* Build up entries in the ARGS array, compute the size of the
3624 arguments into ARGS_SIZE, etc. */
3625 initialize_argument_information (num_actuals, args, &args_size,
3626 n_named_args, exp,
3627 structure_value_addr_value, fndecl, fntype,
3628 args_so_far, reg_parm_stack_space,
3629 &old_stack_level, &old_pending_adj,
3630 &must_preallocate, &flags,
3631 &try_tail_call, CALL_FROM_THUNK_P (exp));
3632
3633 if (args_size.var)
3634 must_preallocate = 1;
3635
3636 /* Now make final decision about preallocating stack space. */
3637 must_preallocate = finalize_must_preallocate (must_preallocate,
3638 num_actuals, args,
3639 &args_size);
3640
3641 /* If the structure value address will reference the stack pointer, we
3642 must stabilize it. We don't need to do this if we know that we are
3643 not going to adjust the stack pointer in processing this call. */
3644
3645 if (structure_value_addr
3646 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
3647 || reg_mentioned_p (virtual_outgoing_args_rtx,
3648 structure_value_addr))
3649 && (args_size.var
3650 || (!ACCUMULATE_OUTGOING_ARGS
3651 && maybe_ne (args_size.constant, 0))))
3652 structure_value_addr = copy_to_reg (structure_value_addr);
3653
3654 /* Tail calls can make things harder to debug, and we've traditionally
3655 pushed these optimizations into -O2. Don't try if we're already
3656 expanding a call, as that means we're an argument. Don't try if
3657 there's cleanups, as we know there's code to follow the call. */
3658 if (currently_expanding_call++ != 0
3659 || (!flag_optimize_sibling_calls && !CALL_FROM_THUNK_P (exp))
3660 || args_size.var
3661 || dbg_cnt (tail_call) == false)
3662 try_tail_call = 0;
3663
3664 /* Workaround buggy C/C++ wrappers around Fortran routines with
3665 character(len=constant) arguments if the hidden string length arguments
3666 are passed on the stack; if the callers forget to pass those arguments,
3667 attempting to tail call in such routines leads to stack corruption.
3668 Avoid tail calls in functions where at least one such hidden string
3669 length argument is passed (partially or fully) on the stack in the
3670 caller and the callee needs to pass any arguments on the stack.
3671 See PR90329. */
3672 if (try_tail_call && maybe_ne (args_size.constant, 0))
3673 for (tree arg = DECL_ARGUMENTS (current_function_decl);
3674 arg; arg = DECL_CHAIN (arg))
3675 if (DECL_HIDDEN_STRING_LENGTH (arg) && DECL_INCOMING_RTL (arg))
3676 {
3677 subrtx_iterator::array_type array;
3678 FOR_EACH_SUBRTX (iter, array, DECL_INCOMING_RTL (arg), NONCONST)
3679 if (MEM_P (*iter))
3680 {
3681 try_tail_call = 0;
3682 break;
3683 }
3684 }
3685
3686 /* If the user has marked the function as requiring tail-call
3687 optimization, attempt it. */
3688 if (must_tail_call)
3689 try_tail_call = 1;
3690
3691 /* Rest of purposes for tail call optimizations to fail. */
3692 if (try_tail_call)
3693 try_tail_call = can_implement_as_sibling_call_p (exp,
3694 structure_value_addr,
3695 funtype,
3696 reg_parm_stack_space,
3697 fndecl,
3698 flags, addr, args_size);
3699
3700 /* Check if caller and callee disagree in promotion of function
3701 return value. */
3702 if (try_tail_call)
3703 {
3704 machine_mode caller_mode, caller_promoted_mode;
3705 machine_mode callee_mode, callee_promoted_mode;
3706 int caller_unsignedp, callee_unsignedp;
3707 tree caller_res = DECL_RESULT (current_function_decl);
3708
3709 caller_unsignedp = TYPE_UNSIGNED (TREE_TYPE (caller_res));
3710 caller_mode = DECL_MODE (caller_res);
3711 callee_unsignedp = TYPE_UNSIGNED (TREE_TYPE (funtype));
3712 callee_mode = TYPE_MODE (TREE_TYPE (funtype));
3713 caller_promoted_mode
3714 = promote_function_mode (TREE_TYPE (caller_res), caller_mode,
3715 &caller_unsignedp,
3716 TREE_TYPE (current_function_decl), 1);
3717 callee_promoted_mode
3718 = promote_function_mode (TREE_TYPE (funtype), callee_mode,
3719 &callee_unsignedp,
3720 funtype, 1);
3721 if (caller_mode != VOIDmode
3722 && (caller_promoted_mode != callee_promoted_mode
3723 || ((caller_mode != caller_promoted_mode
3724 || callee_mode != callee_promoted_mode)
3725 && (caller_unsignedp != callee_unsignedp
3726 || partial_subreg_p (caller_mode, callee_mode)))))
3727 {
3728 try_tail_call = 0;
3729 maybe_complain_about_tail_call (exp,
3730 "caller and callee disagree in"
3731 " promotion of function"
3732 " return value");
3733 }
3734 }
3735
3736 /* Ensure current function's preferred stack boundary is at least
3737 what we need. Stack alignment may also increase preferred stack
3738 boundary. */
3739 for (i = 0; i < num_actuals; i++)
3740 if (reg_parm_stack_space > 0
3741 || args[i].reg == 0
3742 || args[i].partial != 0
3743 || args[i].pass_on_stack)
3744 update_stack_alignment_for_call (&args[i].locate);
3745 if (crtl->preferred_stack_boundary < preferred_stack_boundary)
3746 crtl->preferred_stack_boundary = preferred_stack_boundary;
3747 else
3748 preferred_stack_boundary = crtl->preferred_stack_boundary;
3749
3750 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
3751
3752 /* We want to make two insn chains; one for a sibling call, the other
3753 for a normal call. We will select one of the two chains after
3754 initial RTL generation is complete. */
3755 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
3756 {
3757 int sibcall_failure = 0;
3758 /* We want to emit any pending stack adjustments before the tail
3759 recursion "call". That way we know any adjustment after the tail
3760 recursion call can be ignored if we indeed use the tail
3761 call expansion. */
3762 saved_pending_stack_adjust save;
3763 rtx_insn *insns, *before_call, *after_args;
3764 rtx next_arg_reg;
3765
3766 if (pass == 0)
3767 {
3768 /* State variables we need to save and restore between
3769 iterations. */
3770 save_pending_stack_adjust (&save);
3771 }
3772 if (pass)
3773 flags &= ~ECF_SIBCALL;
3774 else
3775 flags |= ECF_SIBCALL;
3776
3777 /* Other state variables that we must reinitialize each time
3778 through the loop (that are not initialized by the loop itself). */
3779 argblock = 0;
3780 call_fusage = 0;
3781
3782 /* Start a new sequence for the normal call case.
3783
3784 From this point on, if the sibling call fails, we want to set
3785 sibcall_failure instead of continuing the loop. */
3786 start_sequence ();
3787
3788 /* Don't let pending stack adjusts add up to too much.
3789 Also, do all pending adjustments now if there is any chance
3790 this might be a call to alloca or if we are expanding a sibling
3791 call sequence.
3792 Also do the adjustments before a throwing call, otherwise
3793 exception handling can fail; PR 19225. */
3794 if (maybe_ge (pending_stack_adjust, 32)
3795 || (maybe_ne (pending_stack_adjust, 0)
3796 && (flags & ECF_MAY_BE_ALLOCA))
3797 || (maybe_ne (pending_stack_adjust, 0)
3798 && flag_exceptions && !(flags & ECF_NOTHROW))
3799 || pass == 0)
3800 do_pending_stack_adjust ();
3801
3802 /* Precompute any arguments as needed. */
3803 if (pass)
3804 precompute_arguments (num_actuals, args);
3805
3806 /* Now we are about to start emitting insns that can be deleted
3807 if a libcall is deleted. */
3808 if (pass && (flags & ECF_MALLOC))
3809 start_sequence ();
3810
3811 if (pass == 0
3812 && crtl->stack_protect_guard
3813 && targetm.stack_protect_runtime_enabled_p ())
3814 stack_protect_epilogue ();
3815
3816 adjusted_args_size = args_size;
3817 /* Compute the actual size of the argument block required. The variable
3818 and constant sizes must be combined, the size may have to be rounded,
3819 and there may be a minimum required size. When generating a sibcall
3820 pattern, do not round up, since we'll be re-using whatever space our
3821 caller provided. */
3822 unadjusted_args_size
3823 = compute_argument_block_size (reg_parm_stack_space,
3824 &adjusted_args_size,
3825 fndecl, fntype,
3826 (pass == 0 ? 0
3827 : preferred_stack_boundary));
3828
3829 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
3830
3831 /* The argument block when performing a sibling call is the
3832 incoming argument block. */
3833 if (pass == 0)
3834 {
3835 argblock = crtl->args.internal_arg_pointer;
3836 if (STACK_GROWS_DOWNWARD)
3837 argblock
3838 = plus_constant (Pmode, argblock, crtl->args.pretend_args_size);
3839 else
3840 argblock
3841 = plus_constant (Pmode, argblock, -crtl->args.pretend_args_size);
3842
3843 HOST_WIDE_INT map_size = constant_lower_bound (args_size.constant);
3844 stored_args_map = sbitmap_alloc (map_size);
3845 bitmap_clear (stored_args_map);
3846 stored_args_watermark = HOST_WIDE_INT_M1U;
3847 }
3848
3849 /* If we have no actual push instructions, or shouldn't use them,
3850 make space for all args right now. */
3851 else if (adjusted_args_size.var != 0)
3852 {
3853 if (old_stack_level == 0)
3854 {
3855 emit_stack_save (SAVE_BLOCK, &old_stack_level);
3856 old_stack_pointer_delta = stack_pointer_delta;
3857 old_pending_adj = pending_stack_adjust;
3858 pending_stack_adjust = 0;
3859 /* stack_arg_under_construction says whether a stack arg is
3860 being constructed at the old stack level. Pushing the stack
3861 gets a clean outgoing argument block. */
3862 old_stack_arg_under_construction = stack_arg_under_construction;
3863 stack_arg_under_construction = 0;
3864 }
3865 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
3866 if (flag_stack_usage_info)
3867 current_function_has_unbounded_dynamic_stack_size = 1;
3868 }
3869 else
3870 {
3871 /* Note that we must go through the motions of allocating an argument
3872 block even if the size is zero because we may be storing args
3873 in the area reserved for register arguments, which may be part of
3874 the stack frame. */
3875
3876 poly_int64 needed = adjusted_args_size.constant;
3877
3878 /* Store the maximum argument space used. It will be pushed by
3879 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
3880 checking). */
3881
3882 crtl->outgoing_args_size = upper_bound (crtl->outgoing_args_size,
3883 needed);
3884
3885 if (must_preallocate)
3886 {
3887 if (ACCUMULATE_OUTGOING_ARGS)
3888 {
3889 /* Since the stack pointer will never be pushed, it is
3890 possible for the evaluation of a parm to clobber
3891 something we have already written to the stack.
3892 Since most function calls on RISC machines do not use
3893 the stack, this is uncommon, but must work correctly.
3894
3895 Therefore, we save any area of the stack that was already
3896 written and that we are using. Here we set up to do this
3897 by making a new stack usage map from the old one. The
3898 actual save will be done by store_one_arg.
3899
3900 Another approach might be to try to reorder the argument
3901 evaluations to avoid this conflicting stack usage. */
3902
3903 /* Since we will be writing into the entire argument area,
3904 the map must be allocated for its entire size, not just
3905 the part that is the responsibility of the caller. */
3906 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3907 needed += reg_parm_stack_space;
3908
3909 poly_int64 limit = needed;
3910 if (ARGS_GROW_DOWNWARD)
3911 limit += 1;
3912
3913 /* For polynomial sizes, this is the maximum possible
3914 size needed for arguments with a constant size
3915 and offset. */
3916 HOST_WIDE_INT const_limit = constant_lower_bound (limit);
3917 highest_outgoing_arg_in_use
3918 = MAX (initial_highest_arg_in_use, const_limit);
3919
3920 free (stack_usage_map_buf);
3921 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
3922 stack_usage_map = stack_usage_map_buf;
3923
3924 if (initial_highest_arg_in_use)
3925 memcpy (stack_usage_map, initial_stack_usage_map,
3926 initial_highest_arg_in_use);
3927
3928 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3929 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3930 (highest_outgoing_arg_in_use
3931 - initial_highest_arg_in_use));
3932 needed = 0;
3933
3934 /* The address of the outgoing argument list must not be
3935 copied to a register here, because argblock would be left
3936 pointing to the wrong place after the call to
3937 allocate_dynamic_stack_space below. */
3938
3939 argblock = virtual_outgoing_args_rtx;
3940 }
3941 else
3942 {
3943 /* Try to reuse some or all of the pending_stack_adjust
3944 to get this space. */
3945 if (inhibit_defer_pop == 0
3946 && (combine_pending_stack_adjustment_and_call
3947 (&needed,
3948 unadjusted_args_size,
3949 &adjusted_args_size,
3950 preferred_unit_stack_boundary)))
3951 {
3952 /* combine_pending_stack_adjustment_and_call computes
3953 an adjustment before the arguments are allocated.
3954 Account for them and see whether or not the stack
3955 needs to go up or down. */
3956 needed = unadjusted_args_size - needed;
3957
3958 /* Checked by
3959 combine_pending_stack_adjustment_and_call. */
3960 gcc_checking_assert (ordered_p (needed, 0));
3961 if (maybe_lt (needed, 0))
3962 {
3963 /* We're releasing stack space. */
3964 /* ??? We can avoid any adjustment at all if we're
3965 already aligned. FIXME. */
3966 pending_stack_adjust = -needed;
3967 do_pending_stack_adjust ();
3968 needed = 0;
3969 }
3970 else
3971 /* We need to allocate space. We'll do that in
3972 push_block below. */
3973 pending_stack_adjust = 0;
3974 }
3975
3976 /* Special case this because overhead of `push_block' in
3977 this case is non-trivial. */
3978 if (known_eq (needed, 0))
3979 argblock = virtual_outgoing_args_rtx;
3980 else
3981 {
3982 rtx needed_rtx = gen_int_mode (needed, Pmode);
3983 argblock = push_block (needed_rtx, 0, 0);
3984 if (ARGS_GROW_DOWNWARD)
3985 argblock = plus_constant (Pmode, argblock, needed);
3986 }
3987
3988 /* We only really need to call `copy_to_reg' in the case
3989 where push insns are going to be used to pass ARGBLOCK
3990 to a function call in ARGS. In that case, the stack
3991 pointer changes value from the allocation point to the
3992 call point, and hence the value of
3993 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
3994 as well always do it. */
3995 argblock = copy_to_reg (argblock);
3996 }
3997 }
3998 }
3999
4000 if (ACCUMULATE_OUTGOING_ARGS)
4001 {
4002 /* The save/restore code in store_one_arg handles all
4003 cases except one: a constructor call (including a C
4004 function returning a BLKmode struct) to initialize
4005 an argument. */
4006 if (stack_arg_under_construction)
4007 {
4008 rtx push_size
4009 = (gen_int_mode
4010 (adjusted_args_size.constant
4011 + (OUTGOING_REG_PARM_STACK_SPACE (!fndecl ? fntype
4012 : TREE_TYPE (fndecl))
4013 ? 0 : reg_parm_stack_space), Pmode));
4014 if (old_stack_level == 0)
4015 {
4016 emit_stack_save (SAVE_BLOCK, &old_stack_level);
4017 old_stack_pointer_delta = stack_pointer_delta;
4018 old_pending_adj = pending_stack_adjust;
4019 pending_stack_adjust = 0;
4020 /* stack_arg_under_construction says whether a stack
4021 arg is being constructed at the old stack level.
4022 Pushing the stack gets a clean outgoing argument
4023 block. */
4024 old_stack_arg_under_construction
4025 = stack_arg_under_construction;
4026 stack_arg_under_construction = 0;
4027 /* Make a new map for the new argument list. */
4028 free (stack_usage_map_buf);
4029 stack_usage_map_buf = XCNEWVEC (char, highest_outgoing_arg_in_use);
4030 stack_usage_map = stack_usage_map_buf;
4031 highest_outgoing_arg_in_use = 0;
4032 stack_usage_watermark = HOST_WIDE_INT_M1U;
4033 }
4034 /* We can pass TRUE as the 4th argument because we just
4035 saved the stack pointer and will restore it right after
4036 the call. */
4037 allocate_dynamic_stack_space (push_size, 0, BIGGEST_ALIGNMENT,
4038 -1, true);
4039 }
4040
4041 /* If argument evaluation might modify the stack pointer,
4042 copy the address of the argument list to a register. */
4043 for (i = 0; i < num_actuals; i++)
4044 if (args[i].pass_on_stack)
4045 {
4046 argblock = copy_addr_to_reg (argblock);
4047 break;
4048 }
4049 }
4050
4051 compute_argument_addresses (args, argblock, num_actuals);
4052
4053 /* Stack is properly aligned, pops can't safely be deferred during
4054 the evaluation of the arguments. */
4055 NO_DEFER_POP;
4056
4057 /* Precompute all register parameters. It isn't safe to compute
4058 anything once we have started filling any specific hard regs.
4059 TLS symbols sometimes need a call to resolve. Precompute
4060 register parameters before any stack pointer manipulation
4061 to avoid unaligned stack in the called function. */
4062 precompute_register_parameters (num_actuals, args, &reg_parm_seen);
4063
4064 OK_DEFER_POP;
4065
4066 /* Perform stack alignment before the first push (the last arg). */
4067 if (argblock == 0
4068 && maybe_gt (adjusted_args_size.constant, reg_parm_stack_space)
4069 && maybe_ne (adjusted_args_size.constant, unadjusted_args_size))
4070 {
4071 /* When the stack adjustment is pending, we get better code
4072 by combining the adjustments. */
4073 if (maybe_ne (pending_stack_adjust, 0)
4074 && ! inhibit_defer_pop
4075 && (combine_pending_stack_adjustment_and_call
4076 (&pending_stack_adjust,
4077 unadjusted_args_size,
4078 &adjusted_args_size,
4079 preferred_unit_stack_boundary)))
4080 do_pending_stack_adjust ();
4081 else if (argblock == 0)
4082 anti_adjust_stack (gen_int_mode (adjusted_args_size.constant
4083 - unadjusted_args_size,
4084 Pmode));
4085 }
4086 /* Now that the stack is properly aligned, pops can't safely
4087 be deferred during the evaluation of the arguments. */
4088 NO_DEFER_POP;
4089
4090 /* Record the maximum pushed stack space size. We need to delay
4091 doing it this far to take into account the optimization done
4092 by combine_pending_stack_adjustment_and_call. */
4093 if (flag_stack_usage_info
4094 && !ACCUMULATE_OUTGOING_ARGS
4095 && pass
4096 && adjusted_args_size.var == 0)
4097 {
4098 poly_int64 pushed = (adjusted_args_size.constant
4099 + pending_stack_adjust);
4100 current_function_pushed_stack_size
4101 = upper_bound (current_function_pushed_stack_size, pushed);
4102 }
4103
4104 funexp = rtx_for_function_call (fndecl, addr);
4105
4106 if (CALL_EXPR_STATIC_CHAIN (exp))
4107 static_chain_value = expand_normal (CALL_EXPR_STATIC_CHAIN (exp));
4108 else
4109 static_chain_value = 0;
4110
4111 #ifdef REG_PARM_STACK_SPACE
4112 /* Save the fixed argument area if it's part of the caller's frame and
4113 is clobbered by argument setup for this call. */
4114 if (ACCUMULATE_OUTGOING_ARGS && pass)
4115 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
4116 &low_to_save, &high_to_save);
4117 #endif
4118
4119 /* Now store (and compute if necessary) all non-register parms.
4120 These come before register parms, since they can require block-moves,
4121 which could clobber the registers used for register parms.
4122 Parms which have partial registers are not stored here,
4123 but we do preallocate space here if they want that. */
4124
4125 for (i = 0; i < num_actuals; i++)
4126 {
4127 if (args[i].reg == 0 || args[i].pass_on_stack)
4128 {
4129 rtx_insn *before_arg = get_last_insn ();
4130
4131 /* We don't allow passing huge (> 2^30 B) arguments
4132 by value. It would cause an overflow later on. */
4133 if (constant_lower_bound (adjusted_args_size.constant)
4134 >= (1 << (HOST_BITS_PER_INT - 2)))
4135 {
4136 sorry ("passing too large argument on stack");
4137 continue;
4138 }
4139
4140 if (store_one_arg (&args[i], argblock, flags,
4141 adjusted_args_size.var != 0,
4142 reg_parm_stack_space)
4143 || (pass == 0
4144 && check_sibcall_argument_overlap (before_arg,
4145 &args[i], 1)))
4146 sibcall_failure = 1;
4147 }
4148
4149 if (args[i].stack)
4150 call_fusage
4151 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args[i].tree_value)),
4152 gen_rtx_USE (VOIDmode, args[i].stack),
4153 call_fusage);
4154 }
4155
4156 /* If we have a parm that is passed in registers but not in memory
4157 and whose alignment does not permit a direct copy into registers,
4158 make a group of pseudos that correspond to each register that we
4159 will later fill. */
4160 if (STRICT_ALIGNMENT)
4161 store_unaligned_arguments_into_pseudos (args, num_actuals);
4162
4163 /* Now store any partially-in-registers parm.
4164 This is the last place a block-move can happen. */
4165 if (reg_parm_seen)
4166 for (i = 0; i < num_actuals; i++)
4167 if (args[i].partial != 0 && ! args[i].pass_on_stack)
4168 {
4169 rtx_insn *before_arg = get_last_insn ();
4170
4171 /* On targets with weird calling conventions (e.g. PA) it's
4172 hard to ensure that all cases of argument overlap between
4173 stack and registers work. Play it safe and bail out. */
4174 if (ARGS_GROW_DOWNWARD && !STACK_GROWS_DOWNWARD)
4175 {
4176 sibcall_failure = 1;
4177 break;
4178 }
4179
4180 if (store_one_arg (&args[i], argblock, flags,
4181 adjusted_args_size.var != 0,
4182 reg_parm_stack_space)
4183 || (pass == 0
4184 && check_sibcall_argument_overlap (before_arg,
4185 &args[i], 1)))
4186 sibcall_failure = 1;
4187 }
4188
4189 bool any_regs = false;
4190 for (i = 0; i < num_actuals; i++)
4191 if (args[i].reg != NULL_RTX)
4192 {
4193 any_regs = true;
4194 targetm.calls.call_args (args[i].reg, funtype);
4195 }
4196 if (!any_regs)
4197 targetm.calls.call_args (pc_rtx, funtype);
4198
4199 /* Figure out the register where the value, if any, will come back. */
4200 valreg = 0;
4201 if (TYPE_MODE (rettype) != VOIDmode
4202 && ! structure_value_addr)
4203 {
4204 if (pcc_struct_value)
4205 valreg = hard_function_value (build_pointer_type (rettype),
4206 fndecl, NULL, (pass == 0));
4207 else
4208 valreg = hard_function_value (rettype, fndecl, fntype,
4209 (pass == 0));
4210
4211 /* If VALREG is a PARALLEL whose first member has a zero
4212 offset, use that. This is for targets such as m68k that
4213 return the same value in multiple places. */
4214 if (GET_CODE (valreg) == PARALLEL)
4215 {
4216 rtx elem = XVECEXP (valreg, 0, 0);
4217 rtx where = XEXP (elem, 0);
4218 rtx offset = XEXP (elem, 1);
4219 if (offset == const0_rtx
4220 && GET_MODE (where) == GET_MODE (valreg))
4221 valreg = where;
4222 }
4223 }
4224
4225 /* If register arguments require space on the stack and stack space
4226 was not preallocated, allocate stack space here for arguments
4227 passed in registers. */
4228 if (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
4229 && !ACCUMULATE_OUTGOING_ARGS
4230 && must_preallocate == 0 && reg_parm_stack_space > 0)
4231 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
4232
4233 /* Pass the function the address in which to return a
4234 structure value. */
4235 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
4236 {
4237 structure_value_addr
4238 = convert_memory_address (Pmode, structure_value_addr);
4239 emit_move_insn (struct_value,
4240 force_reg (Pmode,
4241 force_operand (structure_value_addr,
4242 NULL_RTX)));
4243
4244 if (REG_P (struct_value))
4245 use_reg (&call_fusage, struct_value);
4246 }
4247
4248 after_args = get_last_insn ();
4249 funexp = prepare_call_address (fndecl ? fndecl : fntype, funexp,
4250 static_chain_value, &call_fusage,
4251 reg_parm_seen, flags);
4252
4253 load_register_parameters (args, num_actuals, &call_fusage, flags,
4254 pass == 0, &sibcall_failure);
4255
4256 /* Save a pointer to the last insn before the call, so that we can
4257 later safely search backwards to find the CALL_INSN. */
4258 before_call = get_last_insn ();
4259
4260 /* Set up next argument register. For sibling calls on machines
4261 with register windows this should be the incoming register. */
4262 if (pass == 0)
4263 next_arg_reg = targetm.calls.function_incoming_arg
4264 (args_so_far, function_arg_info::end_marker ());
4265 else
4266 next_arg_reg = targetm.calls.function_arg
4267 (args_so_far, function_arg_info::end_marker ());
4268
4269 if (pass == 1 && (return_flags & ERF_RETURNS_ARG))
4270 {
4271 int arg_nr = return_flags & ERF_RETURN_ARG_MASK;
4272 arg_nr = num_actuals - arg_nr - 1;
4273 if (arg_nr >= 0
4274 && arg_nr < num_actuals
4275 && args[arg_nr].reg
4276 && valreg
4277 && REG_P (valreg)
4278 && GET_MODE (args[arg_nr].reg) == GET_MODE (valreg))
4279 call_fusage
4280 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args[arg_nr].tree_value)),
4281 gen_rtx_SET (valreg, args[arg_nr].reg),
4282 call_fusage);
4283 }
4284 /* All arguments and registers used for the call must be set up by
4285 now! */
4286
4287 /* Stack must be properly aligned now. */
4288 gcc_assert (!pass
4289 || multiple_p (stack_pointer_delta,
4290 preferred_unit_stack_boundary));
4291
4292 /* Generate the actual call instruction. */
4293 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
4294 adjusted_args_size.constant, struct_value_size,
4295 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
4296 flags, args_so_far);
4297
4298 if (flag_ipa_ra)
4299 {
4300 rtx_call_insn *last;
4301 rtx datum = NULL_RTX;
4302 if (fndecl != NULL_TREE)
4303 {
4304 datum = XEXP (DECL_RTL (fndecl), 0);
4305 gcc_assert (datum != NULL_RTX
4306 && GET_CODE (datum) == SYMBOL_REF);
4307 }
4308 last = last_call_insn ();
4309 add_reg_note (last, REG_CALL_DECL, datum);
4310 }
4311
4312 /* If the call setup or the call itself overlaps with anything
4313 of the argument setup we probably clobbered our call address.
4314 In that case we can't do sibcalls. */
4315 if (pass == 0
4316 && check_sibcall_argument_overlap (after_args, 0, 0))
4317 sibcall_failure = 1;
4318
4319 /* If a non-BLKmode value is returned at the most significant end
4320 of a register, shift the register right by the appropriate amount
4321 and update VALREG accordingly. BLKmode values are handled by the
4322 group load/store machinery below. */
4323 if (!structure_value_addr
4324 && !pcc_struct_value
4325 && TYPE_MODE (rettype) != VOIDmode
4326 && TYPE_MODE (rettype) != BLKmode
4327 && REG_P (valreg)
4328 && targetm.calls.return_in_msb (rettype))
4329 {
4330 if (shift_return_value (TYPE_MODE (rettype), false, valreg))
4331 sibcall_failure = 1;
4332 valreg = gen_rtx_REG (TYPE_MODE (rettype), REGNO (valreg));
4333 }
4334
4335 if (pass && (flags & ECF_MALLOC))
4336 {
4337 rtx temp = gen_reg_rtx (GET_MODE (valreg));
4338 rtx_insn *last, *insns;
4339
4340 /* The return value from a malloc-like function is a pointer. */
4341 if (TREE_CODE (rettype) == POINTER_TYPE)
4342 mark_reg_pointer (temp, MALLOC_ABI_ALIGNMENT);
4343
4344 emit_move_insn (temp, valreg);
4345
4346 /* The return value from a malloc-like function cannot alias
4347 anything else. */
4348 last = get_last_insn ();
4349 add_reg_note (last, REG_NOALIAS, temp);
4350
4351 /* Write out the sequence. */
4352 insns = get_insns ();
4353 end_sequence ();
4354 emit_insn (insns);
4355 valreg = temp;
4356 }
4357
4358 /* For calls to `setjmp', etc., inform
4359 function.c:setjmp_warnings that it should complain if
4360 nonvolatile values are live. For functions that cannot
4361 return, inform flow that control does not fall through. */
4362
4363 if ((flags & ECF_NORETURN) || pass == 0)
4364 {
4365 /* The barrier must be emitted
4366 immediately after the CALL_INSN. Some ports emit more
4367 than just a CALL_INSN above, so we must search for it here. */
4368
4369 rtx_insn *last = get_last_insn ();
4370 while (!CALL_P (last))
4371 {
4372 last = PREV_INSN (last);
4373 /* There was no CALL_INSN? */
4374 gcc_assert (last != before_call);
4375 }
4376
4377 emit_barrier_after (last);
4378
4379 /* Stack adjustments after a noreturn call are dead code.
4380 However when NO_DEFER_POP is in effect, we must preserve
4381 stack_pointer_delta. */
4382 if (inhibit_defer_pop == 0)
4383 {
4384 stack_pointer_delta = old_stack_allocated;
4385 pending_stack_adjust = 0;
4386 }
4387 }
4388
4389 /* If value type not void, return an rtx for the value. */
4390
4391 if (TYPE_MODE (rettype) == VOIDmode
4392 || ignore)
4393 target = const0_rtx;
4394 else if (structure_value_addr)
4395 {
4396 if (target == 0 || !MEM_P (target))
4397 {
4398 target
4399 = gen_rtx_MEM (TYPE_MODE (rettype),
4400 memory_address (TYPE_MODE (rettype),
4401 structure_value_addr));
4402 set_mem_attributes (target, rettype, 1);
4403 }
4404 }
4405 else if (pcc_struct_value)
4406 {
4407 /* This is the special C++ case where we need to
4408 know what the true target was. We take care to
4409 never use this value more than once in one expression. */
4410 target = gen_rtx_MEM (TYPE_MODE (rettype),
4411 copy_to_reg (valreg));
4412 set_mem_attributes (target, rettype, 1);
4413 }
4414 /* Handle calls that return values in multiple non-contiguous locations.
4415 The Irix 6 ABI has examples of this. */
4416 else if (GET_CODE (valreg) == PARALLEL)
4417 {
4418 if (target == 0)
4419 target = emit_group_move_into_temps (valreg);
4420 else if (rtx_equal_p (target, valreg))
4421 ;
4422 else if (GET_CODE (target) == PARALLEL)
4423 /* Handle the result of a emit_group_move_into_temps
4424 call in the previous pass. */
4425 emit_group_move (target, valreg);
4426 else
4427 emit_group_store (target, valreg, rettype,
4428 int_size_in_bytes (rettype));
4429 }
4430 else if (target
4431 && GET_MODE (target) == TYPE_MODE (rettype)
4432 && GET_MODE (target) == GET_MODE (valreg))
4433 {
4434 bool may_overlap = false;
4435
4436 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
4437 reg to a plain register. */
4438 if (!REG_P (target) || HARD_REGISTER_P (target))
4439 valreg = avoid_likely_spilled_reg (valreg);
4440
4441 /* If TARGET is a MEM in the argument area, and we have
4442 saved part of the argument area, then we can't store
4443 directly into TARGET as it may get overwritten when we
4444 restore the argument save area below. Don't work too
4445 hard though and simply force TARGET to a register if it
4446 is a MEM; the optimizer is quite likely to sort it out. */
4447 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target))
4448 for (i = 0; i < num_actuals; i++)
4449 if (args[i].save_area)
4450 {
4451 may_overlap = true;
4452 break;
4453 }
4454
4455 if (may_overlap)
4456 target = copy_to_reg (valreg);
4457 else
4458 {
4459 /* TARGET and VALREG cannot be equal at this point
4460 because the latter would not have
4461 REG_FUNCTION_VALUE_P true, while the former would if
4462 it were referring to the same register.
4463
4464 If they refer to the same register, this move will be
4465 a no-op, except when function inlining is being
4466 done. */
4467 emit_move_insn (target, valreg);
4468
4469 /* If we are setting a MEM, this code must be executed.
4470 Since it is emitted after the call insn, sibcall
4471 optimization cannot be performed in that case. */
4472 if (MEM_P (target))
4473 sibcall_failure = 1;
4474 }
4475 }
4476 else
4477 target = copy_to_reg (avoid_likely_spilled_reg (valreg));
4478
4479 /* If we promoted this return value, make the proper SUBREG.
4480 TARGET might be const0_rtx here, so be careful. */
4481 if (REG_P (target)
4482 && TYPE_MODE (rettype) != BLKmode
4483 && GET_MODE (target) != TYPE_MODE (rettype))
4484 {
4485 tree type = rettype;
4486 int unsignedp = TYPE_UNSIGNED (type);
4487 machine_mode pmode;
4488
4489 /* Ensure we promote as expected, and get the new unsignedness. */
4490 pmode = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
4491 funtype, 1);
4492 gcc_assert (GET_MODE (target) == pmode);
4493
4494 poly_uint64 offset = subreg_lowpart_offset (TYPE_MODE (type),
4495 GET_MODE (target));
4496 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
4497 SUBREG_PROMOTED_VAR_P (target) = 1;
4498 SUBREG_PROMOTED_SET (target, unsignedp);
4499 }
4500
4501 /* If size of args is variable or this was a constructor call for a stack
4502 argument, restore saved stack-pointer value. */
4503
4504 if (old_stack_level)
4505 {
4506 rtx_insn *prev = get_last_insn ();
4507
4508 emit_stack_restore (SAVE_BLOCK, old_stack_level);
4509 stack_pointer_delta = old_stack_pointer_delta;
4510
4511 fixup_args_size_notes (prev, get_last_insn (), stack_pointer_delta);
4512
4513 pending_stack_adjust = old_pending_adj;
4514 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
4515 stack_arg_under_construction = old_stack_arg_under_construction;
4516 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4517 stack_usage_map = initial_stack_usage_map;
4518 stack_usage_watermark = initial_stack_usage_watermark;
4519 sibcall_failure = 1;
4520 }
4521 else if (ACCUMULATE_OUTGOING_ARGS && pass)
4522 {
4523 #ifdef REG_PARM_STACK_SPACE
4524 if (save_area)
4525 restore_fixed_argument_area (save_area, argblock,
4526 high_to_save, low_to_save);
4527 #endif
4528
4529 /* If we saved any argument areas, restore them. */
4530 for (i = 0; i < num_actuals; i++)
4531 if (args[i].save_area)
4532 {
4533 machine_mode save_mode = GET_MODE (args[i].save_area);
4534 rtx stack_area
4535 = gen_rtx_MEM (save_mode,
4536 memory_address (save_mode,
4537 XEXP (args[i].stack_slot, 0)));
4538
4539 if (save_mode != BLKmode)
4540 emit_move_insn (stack_area, args[i].save_area);
4541 else
4542 emit_block_move (stack_area, args[i].save_area,
4543 (gen_int_mode
4544 (args[i].locate.size.constant, Pmode)),
4545 BLOCK_OP_CALL_PARM);
4546 }
4547
4548 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4549 stack_usage_map = initial_stack_usage_map;
4550 stack_usage_watermark = initial_stack_usage_watermark;
4551 }
4552
4553 /* If this was alloca, record the new stack level. */
4554 if (flags & ECF_MAY_BE_ALLOCA)
4555 record_new_stack_level ();
4556
4557 /* Free up storage we no longer need. */
4558 for (i = 0; i < num_actuals; ++i)
4559 free (args[i].aligned_regs);
4560
4561 targetm.calls.end_call_args ();
4562
4563 insns = get_insns ();
4564 end_sequence ();
4565
4566 if (pass == 0)
4567 {
4568 tail_call_insns = insns;
4569
4570 /* Restore the pending stack adjustment now that we have
4571 finished generating the sibling call sequence. */
4572
4573 restore_pending_stack_adjust (&save);
4574
4575 /* Prepare arg structure for next iteration. */
4576 for (i = 0; i < num_actuals; i++)
4577 {
4578 args[i].value = 0;
4579 args[i].aligned_regs = 0;
4580 args[i].stack = 0;
4581 }
4582
4583 sbitmap_free (stored_args_map);
4584 internal_arg_pointer_exp_state.scan_start = NULL;
4585 internal_arg_pointer_exp_state.cache.release ();
4586 }
4587 else
4588 {
4589 normal_call_insns = insns;
4590
4591 /* Verify that we've deallocated all the stack we used. */
4592 gcc_assert ((flags & ECF_NORETURN)
4593 || known_eq (old_stack_allocated,
4594 stack_pointer_delta
4595 - pending_stack_adjust));
4596 }
4597
4598 /* If something prevents making this a sibling call,
4599 zero out the sequence. */
4600 if (sibcall_failure)
4601 tail_call_insns = NULL;
4602 else
4603 break;
4604 }
4605
4606 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
4607 arguments too, as argument area is now clobbered by the call. */
4608 if (tail_call_insns)
4609 {
4610 emit_insn (tail_call_insns);
4611 crtl->tail_call_emit = true;
4612 }
4613 else
4614 {
4615 emit_insn (normal_call_insns);
4616 if (try_tail_call)
4617 /* Ideally we'd emit a message for all of the ways that it could
4618 have failed. */
4619 maybe_complain_about_tail_call (exp, "tail call production failed");
4620 }
4621
4622 currently_expanding_call--;
4623
4624 free (stack_usage_map_buf);
4625 free (args);
4626 return target;
4627 }
4628
4629 /* A sibling call sequence invalidates any REG_EQUIV notes made for
4630 this function's incoming arguments.
4631
4632 At the start of RTL generation we know the only REG_EQUIV notes
4633 in the rtl chain are those for incoming arguments, so we can look
4634 for REG_EQUIV notes between the start of the function and the
4635 NOTE_INSN_FUNCTION_BEG.
4636
4637 This is (slight) overkill. We could keep track of the highest
4638 argument we clobber and be more selective in removing notes, but it
4639 does not seem to be worth the effort. */
4640
4641 void
4642 fixup_tail_calls (void)
4643 {
4644 rtx_insn *insn;
4645
4646 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
4647 {
4648 rtx note;
4649
4650 /* There are never REG_EQUIV notes for the incoming arguments
4651 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
4652 if (NOTE_P (insn)
4653 && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG)
4654 break;
4655
4656 note = find_reg_note (insn, REG_EQUIV, 0);
4657 if (note)
4658 remove_note (insn, note);
4659 note = find_reg_note (insn, REG_EQUIV, 0);
4660 gcc_assert (!note);
4661 }
4662 }
4663
4664 /* Traverse a list of TYPES and expand all complex types into their
4665 components. */
4666 static tree
4667 split_complex_types (tree types)
4668 {
4669 tree p;
4670
4671 /* Before allocating memory, check for the common case of no complex. */
4672 for (p = types; p; p = TREE_CHAIN (p))
4673 {
4674 tree type = TREE_VALUE (p);
4675 if (TREE_CODE (type) == COMPLEX_TYPE
4676 && targetm.calls.split_complex_arg (type))
4677 goto found;
4678 }
4679 return types;
4680
4681 found:
4682 types = copy_list (types);
4683
4684 for (p = types; p; p = TREE_CHAIN (p))
4685 {
4686 tree complex_type = TREE_VALUE (p);
4687
4688 if (TREE_CODE (complex_type) == COMPLEX_TYPE
4689 && targetm.calls.split_complex_arg (complex_type))
4690 {
4691 tree next, imag;
4692
4693 /* Rewrite complex type with component type. */
4694 TREE_VALUE (p) = TREE_TYPE (complex_type);
4695 next = TREE_CHAIN (p);
4696
4697 /* Add another component type for the imaginary part. */
4698 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
4699 TREE_CHAIN (p) = imag;
4700 TREE_CHAIN (imag) = next;
4701
4702 /* Skip the newly created node. */
4703 p = TREE_CHAIN (p);
4704 }
4705 }
4706
4707 return types;
4708 }
4709 \f
4710 /* Output a library call to function ORGFUN (a SYMBOL_REF rtx)
4711 for a value of mode OUTMODE,
4712 with NARGS different arguments, passed as ARGS.
4713 Store the return value if RETVAL is nonzero: store it in VALUE if
4714 VALUE is nonnull, otherwise pick a convenient location. In either
4715 case return the location of the stored value.
4716
4717 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
4718 `const' calls, LCT_PURE for `pure' calls, or another LCT_ value for
4719 other types of library calls. */
4720
4721 rtx
4722 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
4723 enum libcall_type fn_type,
4724 machine_mode outmode, int nargs, rtx_mode_t *args)
4725 {
4726 /* Total size in bytes of all the stack-parms scanned so far. */
4727 struct args_size args_size;
4728 /* Size of arguments before any adjustments (such as rounding). */
4729 struct args_size original_args_size;
4730 int argnum;
4731 rtx fun;
4732 /* Todo, choose the correct decl type of orgfun. Sadly this information
4733 isn't present here, so we default to native calling abi here. */
4734 tree fndecl ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
4735 tree fntype ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
4736 int count;
4737 rtx argblock = 0;
4738 CUMULATIVE_ARGS args_so_far_v;
4739 cumulative_args_t args_so_far;
4740 struct arg
4741 {
4742 rtx value;
4743 machine_mode mode;
4744 rtx reg;
4745 int partial;
4746 struct locate_and_pad_arg_data locate;
4747 rtx save_area;
4748 };
4749 struct arg *argvec;
4750 int old_inhibit_defer_pop = inhibit_defer_pop;
4751 rtx call_fusage = 0;
4752 rtx mem_value = 0;
4753 rtx valreg;
4754 int pcc_struct_value = 0;
4755 poly_int64 struct_value_size = 0;
4756 int flags;
4757 int reg_parm_stack_space = 0;
4758 poly_int64 needed;
4759 rtx_insn *before_call;
4760 bool have_push_fusage;
4761 tree tfom; /* type_for_mode (outmode, 0) */
4762
4763 #ifdef REG_PARM_STACK_SPACE
4764 /* Define the boundary of the register parm stack space that needs to be
4765 save, if any. */
4766 int low_to_save = 0, high_to_save = 0;
4767 rtx save_area = 0; /* Place that it is saved. */
4768 #endif
4769
4770 /* Size of the stack reserved for parameter registers. */
4771 unsigned int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
4772 char *initial_stack_usage_map = stack_usage_map;
4773 unsigned HOST_WIDE_INT initial_stack_usage_watermark = stack_usage_watermark;
4774 char *stack_usage_map_buf = NULL;
4775
4776 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
4777
4778 #ifdef REG_PARM_STACK_SPACE
4779 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
4780 #endif
4781
4782 /* By default, library functions cannot throw. */
4783 flags = ECF_NOTHROW;
4784
4785 switch (fn_type)
4786 {
4787 case LCT_NORMAL:
4788 break;
4789 case LCT_CONST:
4790 flags |= ECF_CONST;
4791 break;
4792 case LCT_PURE:
4793 flags |= ECF_PURE;
4794 break;
4795 case LCT_NORETURN:
4796 flags |= ECF_NORETURN;
4797 break;
4798 case LCT_THROW:
4799 flags &= ~ECF_NOTHROW;
4800 break;
4801 case LCT_RETURNS_TWICE:
4802 flags = ECF_RETURNS_TWICE;
4803 break;
4804 }
4805 fun = orgfun;
4806
4807 /* Ensure current function's preferred stack boundary is at least
4808 what we need. */
4809 if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
4810 crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
4811
4812 /* If this kind of value comes back in memory,
4813 decide where in memory it should come back. */
4814 if (outmode != VOIDmode)
4815 {
4816 tfom = lang_hooks.types.type_for_mode (outmode, 0);
4817 if (aggregate_value_p (tfom, 0))
4818 {
4819 #ifdef PCC_STATIC_STRUCT_RETURN
4820 rtx pointer_reg
4821 = hard_function_value (build_pointer_type (tfom), 0, 0, 0);
4822 mem_value = gen_rtx_MEM (outmode, pointer_reg);
4823 pcc_struct_value = 1;
4824 if (value == 0)
4825 value = gen_reg_rtx (outmode);
4826 #else /* not PCC_STATIC_STRUCT_RETURN */
4827 struct_value_size = GET_MODE_SIZE (outmode);
4828 if (value != 0 && MEM_P (value))
4829 mem_value = value;
4830 else
4831 mem_value = assign_temp (tfom, 1, 1);
4832 #endif
4833 /* This call returns a big structure. */
4834 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
4835 }
4836 }
4837 else
4838 tfom = void_type_node;
4839
4840 /* ??? Unfinished: must pass the memory address as an argument. */
4841
4842 /* Copy all the libcall-arguments out of the varargs data
4843 and into a vector ARGVEC.
4844
4845 Compute how to pass each argument. We only support a very small subset
4846 of the full argument passing conventions to limit complexity here since
4847 library functions shouldn't have many args. */
4848
4849 argvec = XALLOCAVEC (struct arg, nargs + 1);
4850 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
4851
4852 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
4853 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far_v, outmode, fun);
4854 #else
4855 INIT_CUMULATIVE_ARGS (args_so_far_v, NULL_TREE, fun, 0, nargs);
4856 #endif
4857 args_so_far = pack_cumulative_args (&args_so_far_v);
4858
4859 args_size.constant = 0;
4860 args_size.var = 0;
4861
4862 count = 0;
4863
4864 push_temp_slots ();
4865
4866 /* If there's a structure value address to be passed,
4867 either pass it in the special place, or pass it as an extra argument. */
4868 if (mem_value && struct_value == 0 && ! pcc_struct_value)
4869 {
4870 rtx addr = XEXP (mem_value, 0);
4871
4872 nargs++;
4873
4874 /* Make sure it is a reasonable operand for a move or push insn. */
4875 if (!REG_P (addr) && !MEM_P (addr)
4876 && !(CONSTANT_P (addr)
4877 && targetm.legitimate_constant_p (Pmode, addr)))
4878 addr = force_operand (addr, NULL_RTX);
4879
4880 argvec[count].value = addr;
4881 argvec[count].mode = Pmode;
4882 argvec[count].partial = 0;
4883
4884 function_arg_info ptr_arg (Pmode, /*named=*/true);
4885 argvec[count].reg = targetm.calls.function_arg (args_so_far, ptr_arg);
4886 gcc_assert (targetm.calls.arg_partial_bytes (args_so_far, ptr_arg) == 0);
4887
4888 locate_and_pad_parm (Pmode, NULL_TREE,
4889 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4890 1,
4891 #else
4892 argvec[count].reg != 0,
4893 #endif
4894 reg_parm_stack_space, 0,
4895 NULL_TREE, &args_size, &argvec[count].locate);
4896
4897 if (argvec[count].reg == 0 || argvec[count].partial != 0
4898 || reg_parm_stack_space > 0)
4899 args_size.constant += argvec[count].locate.size.constant;
4900
4901 targetm.calls.function_arg_advance (args_so_far, ptr_arg);
4902
4903 count++;
4904 }
4905
4906 for (unsigned int i = 0; count < nargs; i++, count++)
4907 {
4908 rtx val = args[i].first;
4909 machine_mode mode = args[i].second;
4910 int unsigned_p = 0;
4911
4912 /* We cannot convert the arg value to the mode the library wants here;
4913 must do it earlier where we know the signedness of the arg. */
4914 gcc_assert (mode != BLKmode
4915 && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode));
4916
4917 /* Make sure it is a reasonable operand for a move or push insn. */
4918 if (!REG_P (val) && !MEM_P (val)
4919 && !(CONSTANT_P (val) && targetm.legitimate_constant_p (mode, val)))
4920 val = force_operand (val, NULL_RTX);
4921
4922 function_arg_info orig_arg (mode, /*named=*/true);
4923 if (pass_by_reference (&args_so_far_v, orig_arg))
4924 {
4925 rtx slot;
4926 int must_copy = !reference_callee_copied (&args_so_far_v, orig_arg);
4927
4928 /* If this was a CONST function, it is now PURE since it now
4929 reads memory. */
4930 if (flags & ECF_CONST)
4931 {
4932 flags &= ~ECF_CONST;
4933 flags |= ECF_PURE;
4934 }
4935
4936 if (MEM_P (val) && !must_copy)
4937 {
4938 tree val_expr = MEM_EXPR (val);
4939 if (val_expr)
4940 mark_addressable (val_expr);
4941 slot = val;
4942 }
4943 else
4944 {
4945 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0),
4946 1, 1);
4947 emit_move_insn (slot, val);
4948 }
4949
4950 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
4951 gen_rtx_USE (VOIDmode, slot),
4952 call_fusage);
4953 if (must_copy)
4954 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
4955 gen_rtx_CLOBBER (VOIDmode,
4956 slot),
4957 call_fusage);
4958
4959 mode = Pmode;
4960 val = force_operand (XEXP (slot, 0), NULL_RTX);
4961 }
4962
4963 mode = promote_function_mode (NULL_TREE, mode, &unsigned_p, NULL_TREE, 0);
4964 function_arg_info arg (mode, /*named=*/true);
4965 argvec[count].mode = mode;
4966 argvec[count].value = convert_modes (mode, GET_MODE (val), val, unsigned_p);
4967 argvec[count].reg = targetm.calls.function_arg (args_so_far, arg);
4968
4969 argvec[count].partial
4970 = targetm.calls.arg_partial_bytes (args_so_far, arg);
4971
4972 if (argvec[count].reg == 0
4973 || argvec[count].partial != 0
4974 || reg_parm_stack_space > 0)
4975 {
4976 locate_and_pad_parm (mode, NULL_TREE,
4977 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4978 1,
4979 #else
4980 argvec[count].reg != 0,
4981 #endif
4982 reg_parm_stack_space, argvec[count].partial,
4983 NULL_TREE, &args_size, &argvec[count].locate);
4984 args_size.constant += argvec[count].locate.size.constant;
4985 gcc_assert (!argvec[count].locate.size.var);
4986 }
4987 #ifdef BLOCK_REG_PADDING
4988 else
4989 /* The argument is passed entirely in registers. See at which
4990 end it should be padded. */
4991 argvec[count].locate.where_pad =
4992 BLOCK_REG_PADDING (mode, NULL_TREE,
4993 known_le (GET_MODE_SIZE (mode), UNITS_PER_WORD));
4994 #endif
4995
4996 targetm.calls.function_arg_advance (args_so_far, arg);
4997 }
4998
4999 for (int i = 0; i < nargs; i++)
5000 if (reg_parm_stack_space > 0
5001 || argvec[i].reg == 0
5002 || argvec[i].partial != 0)
5003 update_stack_alignment_for_call (&argvec[i].locate);
5004
5005 /* If this machine requires an external definition for library
5006 functions, write one out. */
5007 assemble_external_libcall (fun);
5008
5009 original_args_size = args_size;
5010 args_size.constant = (aligned_upper_bound (args_size.constant
5011 + stack_pointer_delta,
5012 STACK_BYTES)
5013 - stack_pointer_delta);
5014
5015 args_size.constant = upper_bound (args_size.constant,
5016 reg_parm_stack_space);
5017
5018 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
5019 args_size.constant -= reg_parm_stack_space;
5020
5021 crtl->outgoing_args_size = upper_bound (crtl->outgoing_args_size,
5022 args_size.constant);
5023
5024 if (flag_stack_usage_info && !ACCUMULATE_OUTGOING_ARGS)
5025 {
5026 poly_int64 pushed = args_size.constant + pending_stack_adjust;
5027 current_function_pushed_stack_size
5028 = upper_bound (current_function_pushed_stack_size, pushed);
5029 }
5030
5031 if (ACCUMULATE_OUTGOING_ARGS)
5032 {
5033 /* Since the stack pointer will never be pushed, it is possible for
5034 the evaluation of a parm to clobber something we have already
5035 written to the stack. Since most function calls on RISC machines
5036 do not use the stack, this is uncommon, but must work correctly.
5037
5038 Therefore, we save any area of the stack that was already written
5039 and that we are using. Here we set up to do this by making a new
5040 stack usage map from the old one.
5041
5042 Another approach might be to try to reorder the argument
5043 evaluations to avoid this conflicting stack usage. */
5044
5045 needed = args_size.constant;
5046
5047 /* Since we will be writing into the entire argument area, the
5048 map must be allocated for its entire size, not just the part that
5049 is the responsibility of the caller. */
5050 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
5051 needed += reg_parm_stack_space;
5052
5053 poly_int64 limit = needed;
5054 if (ARGS_GROW_DOWNWARD)
5055 limit += 1;
5056
5057 /* For polynomial sizes, this is the maximum possible size needed
5058 for arguments with a constant size and offset. */
5059 HOST_WIDE_INT const_limit = constant_lower_bound (limit);
5060 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
5061 const_limit);
5062
5063 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
5064 stack_usage_map = stack_usage_map_buf;
5065
5066 if (initial_highest_arg_in_use)
5067 memcpy (stack_usage_map, initial_stack_usage_map,
5068 initial_highest_arg_in_use);
5069
5070 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
5071 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
5072 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
5073 needed = 0;
5074
5075 /* We must be careful to use virtual regs before they're instantiated,
5076 and real regs afterwards. Loop optimization, for example, can create
5077 new libcalls after we've instantiated the virtual regs, and if we
5078 use virtuals anyway, they won't match the rtl patterns. */
5079
5080 if (virtuals_instantiated)
5081 argblock = plus_constant (Pmode, stack_pointer_rtx,
5082 STACK_POINTER_OFFSET);
5083 else
5084 argblock = virtual_outgoing_args_rtx;
5085 }
5086 else
5087 {
5088 if (!PUSH_ARGS)
5089 argblock = push_block (gen_int_mode (args_size.constant, Pmode), 0, 0);
5090 }
5091
5092 /* We push args individually in reverse order, perform stack alignment
5093 before the first push (the last arg). */
5094 if (argblock == 0)
5095 anti_adjust_stack (gen_int_mode (args_size.constant
5096 - original_args_size.constant,
5097 Pmode));
5098
5099 argnum = nargs - 1;
5100
5101 #ifdef REG_PARM_STACK_SPACE
5102 if (ACCUMULATE_OUTGOING_ARGS)
5103 {
5104 /* The argument list is the property of the called routine and it
5105 may clobber it. If the fixed area has been used for previous
5106 parameters, we must save and restore it. */
5107 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
5108 &low_to_save, &high_to_save);
5109 }
5110 #endif
5111
5112 /* When expanding a normal call, args are stored in push order,
5113 which is the reverse of what we have here. */
5114 bool any_regs = false;
5115 for (int i = nargs; i-- > 0; )
5116 if (argvec[i].reg != NULL_RTX)
5117 {
5118 targetm.calls.call_args (argvec[i].reg, NULL_TREE);
5119 any_regs = true;
5120 }
5121 if (!any_regs)
5122 targetm.calls.call_args (pc_rtx, NULL_TREE);
5123
5124 /* Push the args that need to be pushed. */
5125
5126 have_push_fusage = false;
5127
5128 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
5129 are to be pushed. */
5130 for (count = 0; count < nargs; count++, argnum--)
5131 {
5132 machine_mode mode = argvec[argnum].mode;
5133 rtx val = argvec[argnum].value;
5134 rtx reg = argvec[argnum].reg;
5135 int partial = argvec[argnum].partial;
5136 unsigned int parm_align = argvec[argnum].locate.boundary;
5137 poly_int64 lower_bound = 0, upper_bound = 0;
5138
5139 if (! (reg != 0 && partial == 0))
5140 {
5141 rtx use;
5142
5143 if (ACCUMULATE_OUTGOING_ARGS)
5144 {
5145 /* If this is being stored into a pre-allocated, fixed-size,
5146 stack area, save any previous data at that location. */
5147
5148 if (ARGS_GROW_DOWNWARD)
5149 {
5150 /* stack_slot is negative, but we want to index stack_usage_map
5151 with positive values. */
5152 upper_bound = -argvec[argnum].locate.slot_offset.constant + 1;
5153 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
5154 }
5155 else
5156 {
5157 lower_bound = argvec[argnum].locate.slot_offset.constant;
5158 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
5159 }
5160
5161 if (stack_region_maybe_used_p (lower_bound, upper_bound,
5162 reg_parm_stack_space))
5163 {
5164 /* We need to make a save area. */
5165 poly_uint64 size
5166 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
5167 machine_mode save_mode
5168 = int_mode_for_size (size, 1).else_blk ();
5169 rtx adr
5170 = plus_constant (Pmode, argblock,
5171 argvec[argnum].locate.offset.constant);
5172 rtx stack_area
5173 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
5174
5175 if (save_mode == BLKmode)
5176 {
5177 argvec[argnum].save_area
5178 = assign_stack_temp (BLKmode,
5179 argvec[argnum].locate.size.constant
5180 );
5181
5182 emit_block_move (validize_mem
5183 (copy_rtx (argvec[argnum].save_area)),
5184 stack_area,
5185 (gen_int_mode
5186 (argvec[argnum].locate.size.constant,
5187 Pmode)),
5188 BLOCK_OP_CALL_PARM);
5189 }
5190 else
5191 {
5192 argvec[argnum].save_area = gen_reg_rtx (save_mode);
5193
5194 emit_move_insn (argvec[argnum].save_area, stack_area);
5195 }
5196 }
5197 }
5198
5199 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, parm_align,
5200 partial, reg, 0, argblock,
5201 (gen_int_mode
5202 (argvec[argnum].locate.offset.constant, Pmode)),
5203 reg_parm_stack_space,
5204 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad), false);
5205
5206 /* Now mark the segment we just used. */
5207 if (ACCUMULATE_OUTGOING_ARGS)
5208 mark_stack_region_used (lower_bound, upper_bound);
5209
5210 NO_DEFER_POP;
5211
5212 /* Indicate argument access so that alias.c knows that these
5213 values are live. */
5214 if (argblock)
5215 use = plus_constant (Pmode, argblock,
5216 argvec[argnum].locate.offset.constant);
5217 else if (have_push_fusage)
5218 continue;
5219 else
5220 {
5221 /* When arguments are pushed, trying to tell alias.c where
5222 exactly this argument is won't work, because the
5223 auto-increment causes confusion. So we merely indicate
5224 that we access something with a known mode somewhere on
5225 the stack. */
5226 use = gen_rtx_PLUS (Pmode, stack_pointer_rtx,
5227 gen_rtx_SCRATCH (Pmode));
5228 have_push_fusage = true;
5229 }
5230 use = gen_rtx_MEM (argvec[argnum].mode, use);
5231 use = gen_rtx_USE (VOIDmode, use);
5232 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage);
5233 }
5234 }
5235
5236 argnum = nargs - 1;
5237
5238 fun = prepare_call_address (NULL, fun, NULL, &call_fusage, 0, 0);
5239
5240 /* Now load any reg parms into their regs. */
5241
5242 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
5243 are to be pushed. */
5244 for (count = 0; count < nargs; count++, argnum--)
5245 {
5246 machine_mode mode = argvec[argnum].mode;
5247 rtx val = argvec[argnum].value;
5248 rtx reg = argvec[argnum].reg;
5249 int partial = argvec[argnum].partial;
5250
5251 /* Handle calls that pass values in multiple non-contiguous
5252 locations. The PA64 has examples of this for library calls. */
5253 if (reg != 0 && GET_CODE (reg) == PARALLEL)
5254 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
5255 else if (reg != 0 && partial == 0)
5256 {
5257 emit_move_insn (reg, val);
5258 #ifdef BLOCK_REG_PADDING
5259 poly_int64 size = GET_MODE_SIZE (argvec[argnum].mode);
5260
5261 /* Copied from load_register_parameters. */
5262
5263 /* Handle case where we have a value that needs shifting
5264 up to the msb. eg. a QImode value and we're padding
5265 upward on a BYTES_BIG_ENDIAN machine. */
5266 if (known_lt (size, UNITS_PER_WORD)
5267 && (argvec[argnum].locate.where_pad
5268 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
5269 {
5270 rtx x;
5271 poly_int64 shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
5272
5273 /* Assigning REG here rather than a temp makes CALL_FUSAGE
5274 report the whole reg as used. Strictly speaking, the
5275 call only uses SIZE bytes at the msb end, but it doesn't
5276 seem worth generating rtl to say that. */
5277 reg = gen_rtx_REG (word_mode, REGNO (reg));
5278 x = expand_shift (LSHIFT_EXPR, word_mode, reg, shift, reg, 1);
5279 if (x != reg)
5280 emit_move_insn (reg, x);
5281 }
5282 #endif
5283 }
5284
5285 NO_DEFER_POP;
5286 }
5287
5288 /* Any regs containing parms remain in use through the call. */
5289 for (count = 0; count < nargs; count++)
5290 {
5291 rtx reg = argvec[count].reg;
5292 if (reg != 0 && GET_CODE (reg) == PARALLEL)
5293 use_group_regs (&call_fusage, reg);
5294 else if (reg != 0)
5295 {
5296 int partial = argvec[count].partial;
5297 if (partial)
5298 {
5299 int nregs;
5300 gcc_assert (partial % UNITS_PER_WORD == 0);
5301 nregs = partial / UNITS_PER_WORD;
5302 use_regs (&call_fusage, REGNO (reg), nregs);
5303 }
5304 else
5305 use_reg (&call_fusage, reg);
5306 }
5307 }
5308
5309 /* Pass the function the address in which to return a structure value. */
5310 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
5311 {
5312 emit_move_insn (struct_value,
5313 force_reg (Pmode,
5314 force_operand (XEXP (mem_value, 0),
5315 NULL_RTX)));
5316 if (REG_P (struct_value))
5317 use_reg (&call_fusage, struct_value);
5318 }
5319
5320 /* Don't allow popping to be deferred, since then
5321 cse'ing of library calls could delete a call and leave the pop. */
5322 NO_DEFER_POP;
5323 valreg = (mem_value == 0 && outmode != VOIDmode
5324 ? hard_libcall_value (outmode, orgfun) : NULL_RTX);
5325
5326 /* Stack must be properly aligned now. */
5327 gcc_assert (multiple_p (stack_pointer_delta,
5328 PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT));
5329
5330 before_call = get_last_insn ();
5331
5332 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
5333 will set inhibit_defer_pop to that value. */
5334 /* The return type is needed to decide how many bytes the function pops.
5335 Signedness plays no role in that, so for simplicity, we pretend it's
5336 always signed. We also assume that the list of arguments passed has
5337 no impact, so we pretend it is unknown. */
5338
5339 emit_call_1 (fun, NULL,
5340 get_identifier (XSTR (orgfun, 0)),
5341 build_function_type (tfom, NULL_TREE),
5342 original_args_size.constant, args_size.constant,
5343 struct_value_size,
5344 targetm.calls.function_arg (args_so_far,
5345 function_arg_info::end_marker ()),
5346 valreg,
5347 old_inhibit_defer_pop + 1, call_fusage, flags, args_so_far);
5348
5349 if (flag_ipa_ra)
5350 {
5351 rtx datum = orgfun;
5352 gcc_assert (GET_CODE (datum) == SYMBOL_REF);
5353 rtx_call_insn *last = last_call_insn ();
5354 add_reg_note (last, REG_CALL_DECL, datum);
5355 }
5356
5357 /* Right-shift returned value if necessary. */
5358 if (!pcc_struct_value
5359 && TYPE_MODE (tfom) != BLKmode
5360 && targetm.calls.return_in_msb (tfom))
5361 {
5362 shift_return_value (TYPE_MODE (tfom), false, valreg);
5363 valreg = gen_rtx_REG (TYPE_MODE (tfom), REGNO (valreg));
5364 }
5365
5366 targetm.calls.end_call_args ();
5367
5368 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
5369 that it should complain if nonvolatile values are live. For
5370 functions that cannot return, inform flow that control does not
5371 fall through. */
5372 if (flags & ECF_NORETURN)
5373 {
5374 /* The barrier note must be emitted
5375 immediately after the CALL_INSN. Some ports emit more than
5376 just a CALL_INSN above, so we must search for it here. */
5377 rtx_insn *last = get_last_insn ();
5378 while (!CALL_P (last))
5379 {
5380 last = PREV_INSN (last);
5381 /* There was no CALL_INSN? */
5382 gcc_assert (last != before_call);
5383 }
5384
5385 emit_barrier_after (last);
5386 }
5387
5388 /* Consider that "regular" libcalls, i.e. all of them except for LCT_THROW
5389 and LCT_RETURNS_TWICE, cannot perform non-local gotos. */
5390 if (flags & ECF_NOTHROW)
5391 {
5392 rtx_insn *last = get_last_insn ();
5393 while (!CALL_P (last))
5394 {
5395 last = PREV_INSN (last);
5396 /* There was no CALL_INSN? */
5397 gcc_assert (last != before_call);
5398 }
5399
5400 make_reg_eh_region_note_nothrow_nononlocal (last);
5401 }
5402
5403 /* Now restore inhibit_defer_pop to its actual original value. */
5404 OK_DEFER_POP;
5405
5406 pop_temp_slots ();
5407
5408 /* Copy the value to the right place. */
5409 if (outmode != VOIDmode && retval)
5410 {
5411 if (mem_value)
5412 {
5413 if (value == 0)
5414 value = mem_value;
5415 if (value != mem_value)
5416 emit_move_insn (value, mem_value);
5417 }
5418 else if (GET_CODE (valreg) == PARALLEL)
5419 {
5420 if (value == 0)
5421 value = gen_reg_rtx (outmode);
5422 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
5423 }
5424 else
5425 {
5426 /* Convert to the proper mode if a promotion has been active. */
5427 if (GET_MODE (valreg) != outmode)
5428 {
5429 int unsignedp = TYPE_UNSIGNED (tfom);
5430
5431 gcc_assert (promote_function_mode (tfom, outmode, &unsignedp,
5432 fndecl ? TREE_TYPE (fndecl) : fntype, 1)
5433 == GET_MODE (valreg));
5434 valreg = convert_modes (outmode, GET_MODE (valreg), valreg, 0);
5435 }
5436
5437 if (value != 0)
5438 emit_move_insn (value, valreg);
5439 else
5440 value = valreg;
5441 }
5442 }
5443
5444 if (ACCUMULATE_OUTGOING_ARGS)
5445 {
5446 #ifdef REG_PARM_STACK_SPACE
5447 if (save_area)
5448 restore_fixed_argument_area (save_area, argblock,
5449 high_to_save, low_to_save);
5450 #endif
5451
5452 /* If we saved any argument areas, restore them. */
5453 for (count = 0; count < nargs; count++)
5454 if (argvec[count].save_area)
5455 {
5456 machine_mode save_mode = GET_MODE (argvec[count].save_area);
5457 rtx adr = plus_constant (Pmode, argblock,
5458 argvec[count].locate.offset.constant);
5459 rtx stack_area = gen_rtx_MEM (save_mode,
5460 memory_address (save_mode, adr));
5461
5462 if (save_mode == BLKmode)
5463 emit_block_move (stack_area,
5464 validize_mem
5465 (copy_rtx (argvec[count].save_area)),
5466 (gen_int_mode
5467 (argvec[count].locate.size.constant, Pmode)),
5468 BLOCK_OP_CALL_PARM);
5469 else
5470 emit_move_insn (stack_area, argvec[count].save_area);
5471 }
5472
5473 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
5474 stack_usage_map = initial_stack_usage_map;
5475 stack_usage_watermark = initial_stack_usage_watermark;
5476 }
5477
5478 free (stack_usage_map_buf);
5479
5480 return value;
5481
5482 }
5483 \f
5484
5485 /* Store a single argument for a function call
5486 into the register or memory area where it must be passed.
5487 *ARG describes the argument value and where to pass it.
5488
5489 ARGBLOCK is the address of the stack-block for all the arguments,
5490 or 0 on a machine where arguments are pushed individually.
5491
5492 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
5493 so must be careful about how the stack is used.
5494
5495 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
5496 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
5497 that we need not worry about saving and restoring the stack.
5498
5499 FNDECL is the declaration of the function we are calling.
5500
5501 Return nonzero if this arg should cause sibcall failure,
5502 zero otherwise. */
5503
5504 static int
5505 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
5506 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
5507 {
5508 tree pval = arg->tree_value;
5509 rtx reg = 0;
5510 int partial = 0;
5511 poly_int64 used = 0;
5512 poly_int64 lower_bound = 0, upper_bound = 0;
5513 int sibcall_failure = 0;
5514
5515 if (TREE_CODE (pval) == ERROR_MARK)
5516 return 1;
5517
5518 /* Push a new temporary level for any temporaries we make for
5519 this argument. */
5520 push_temp_slots ();
5521
5522 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
5523 {
5524 /* If this is being stored into a pre-allocated, fixed-size, stack area,
5525 save any previous data at that location. */
5526 if (argblock && ! variable_size && arg->stack)
5527 {
5528 if (ARGS_GROW_DOWNWARD)
5529 {
5530 /* stack_slot is negative, but we want to index stack_usage_map
5531 with positive values. */
5532 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
5533 {
5534 rtx offset = XEXP (XEXP (arg->stack_slot, 0), 1);
5535 upper_bound = -rtx_to_poly_int64 (offset) + 1;
5536 }
5537 else
5538 upper_bound = 0;
5539
5540 lower_bound = upper_bound - arg->locate.size.constant;
5541 }
5542 else
5543 {
5544 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
5545 {
5546 rtx offset = XEXP (XEXP (arg->stack_slot, 0), 1);
5547 lower_bound = rtx_to_poly_int64 (offset);
5548 }
5549 else
5550 lower_bound = 0;
5551
5552 upper_bound = lower_bound + arg->locate.size.constant;
5553 }
5554
5555 if (stack_region_maybe_used_p (lower_bound, upper_bound,
5556 reg_parm_stack_space))
5557 {
5558 /* We need to make a save area. */
5559 poly_uint64 size = arg->locate.size.constant * BITS_PER_UNIT;
5560 machine_mode save_mode
5561 = int_mode_for_size (size, 1).else_blk ();
5562 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
5563 rtx stack_area = gen_rtx_MEM (save_mode, adr);
5564
5565 if (save_mode == BLKmode)
5566 {
5567 arg->save_area
5568 = assign_temp (TREE_TYPE (arg->tree_value), 1, 1);
5569 preserve_temp_slots (arg->save_area);
5570 emit_block_move (validize_mem (copy_rtx (arg->save_area)),
5571 stack_area,
5572 (gen_int_mode
5573 (arg->locate.size.constant, Pmode)),
5574 BLOCK_OP_CALL_PARM);
5575 }
5576 else
5577 {
5578 arg->save_area = gen_reg_rtx (save_mode);
5579 emit_move_insn (arg->save_area, stack_area);
5580 }
5581 }
5582 }
5583 }
5584
5585 /* If this isn't going to be placed on both the stack and in registers,
5586 set up the register and number of words. */
5587 if (! arg->pass_on_stack)
5588 {
5589 if (flags & ECF_SIBCALL)
5590 reg = arg->tail_call_reg;
5591 else
5592 reg = arg->reg;
5593 partial = arg->partial;
5594 }
5595
5596 /* Being passed entirely in a register. We shouldn't be called in
5597 this case. */
5598 gcc_assert (reg == 0 || partial != 0);
5599
5600 /* If this arg needs special alignment, don't load the registers
5601 here. */
5602 if (arg->n_aligned_regs != 0)
5603 reg = 0;
5604
5605 /* If this is being passed partially in a register, we can't evaluate
5606 it directly into its stack slot. Otherwise, we can. */
5607 if (arg->value == 0)
5608 {
5609 /* stack_arg_under_construction is nonzero if a function argument is
5610 being evaluated directly into the outgoing argument list and
5611 expand_call must take special action to preserve the argument list
5612 if it is called recursively.
5613
5614 For scalar function arguments stack_usage_map is sufficient to
5615 determine which stack slots must be saved and restored. Scalar
5616 arguments in general have pass_on_stack == 0.
5617
5618 If this argument is initialized by a function which takes the
5619 address of the argument (a C++ constructor or a C function
5620 returning a BLKmode structure), then stack_usage_map is
5621 insufficient and expand_call must push the stack around the
5622 function call. Such arguments have pass_on_stack == 1.
5623
5624 Note that it is always safe to set stack_arg_under_construction,
5625 but this generates suboptimal code if set when not needed. */
5626
5627 if (arg->pass_on_stack)
5628 stack_arg_under_construction++;
5629
5630 arg->value = expand_expr (pval,
5631 (partial
5632 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
5633 ? NULL_RTX : arg->stack,
5634 VOIDmode, EXPAND_STACK_PARM);
5635
5636 /* If we are promoting object (or for any other reason) the mode
5637 doesn't agree, convert the mode. */
5638
5639 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
5640 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
5641 arg->value, arg->unsignedp);
5642
5643 if (arg->pass_on_stack)
5644 stack_arg_under_construction--;
5645 }
5646
5647 /* Check for overlap with already clobbered argument area. */
5648 if ((flags & ECF_SIBCALL)
5649 && MEM_P (arg->value)
5650 && mem_might_overlap_already_clobbered_arg_p (XEXP (arg->value, 0),
5651 arg->locate.size.constant))
5652 sibcall_failure = 1;
5653
5654 /* Don't allow anything left on stack from computation
5655 of argument to alloca. */
5656 if (flags & ECF_MAY_BE_ALLOCA)
5657 do_pending_stack_adjust ();
5658
5659 if (arg->value == arg->stack)
5660 /* If the value is already in the stack slot, we are done. */
5661 ;
5662 else if (arg->mode != BLKmode)
5663 {
5664 unsigned int parm_align;
5665
5666 /* Argument is a scalar, not entirely passed in registers.
5667 (If part is passed in registers, arg->partial says how much
5668 and emit_push_insn will take care of putting it there.)
5669
5670 Push it, and if its size is less than the
5671 amount of space allocated to it,
5672 also bump stack pointer by the additional space.
5673 Note that in C the default argument promotions
5674 will prevent such mismatches. */
5675
5676 poly_int64 size = (TYPE_EMPTY_P (TREE_TYPE (pval))
5677 ? 0 : GET_MODE_SIZE (arg->mode));
5678
5679 /* Compute how much space the push instruction will push.
5680 On many machines, pushing a byte will advance the stack
5681 pointer by a halfword. */
5682 #ifdef PUSH_ROUNDING
5683 size = PUSH_ROUNDING (size);
5684 #endif
5685 used = size;
5686
5687 /* Compute how much space the argument should get:
5688 round up to a multiple of the alignment for arguments. */
5689 if (targetm.calls.function_arg_padding (arg->mode, TREE_TYPE (pval))
5690 != PAD_NONE)
5691 /* At the moment we don't (need to) support ABIs for which the
5692 padding isn't known at compile time. In principle it should
5693 be easy to add though. */
5694 used = force_align_up (size, PARM_BOUNDARY / BITS_PER_UNIT);
5695
5696 /* Compute the alignment of the pushed argument. */
5697 parm_align = arg->locate.boundary;
5698 if (targetm.calls.function_arg_padding (arg->mode, TREE_TYPE (pval))
5699 == PAD_DOWNWARD)
5700 {
5701 poly_int64 pad = used - size;
5702 unsigned int pad_align = known_alignment (pad) * BITS_PER_UNIT;
5703 if (pad_align != 0)
5704 parm_align = MIN (parm_align, pad_align);
5705 }
5706
5707 /* This isn't already where we want it on the stack, so put it there.
5708 This can either be done with push or copy insns. */
5709 if (maybe_ne (used, 0)
5710 && !emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval),
5711 NULL_RTX, parm_align, partial, reg, used - size,
5712 argblock, ARGS_SIZE_RTX (arg->locate.offset),
5713 reg_parm_stack_space,
5714 ARGS_SIZE_RTX (arg->locate.alignment_pad), true))
5715 sibcall_failure = 1;
5716
5717 /* Unless this is a partially-in-register argument, the argument is now
5718 in the stack. */
5719 if (partial == 0)
5720 arg->value = arg->stack;
5721 }
5722 else
5723 {
5724 /* BLKmode, at least partly to be pushed. */
5725
5726 unsigned int parm_align;
5727 poly_int64 excess;
5728 rtx size_rtx;
5729
5730 /* Pushing a nonscalar.
5731 If part is passed in registers, PARTIAL says how much
5732 and emit_push_insn will take care of putting it there. */
5733
5734 /* Round its size up to a multiple
5735 of the allocation unit for arguments. */
5736
5737 if (arg->locate.size.var != 0)
5738 {
5739 excess = 0;
5740 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
5741 }
5742 else
5743 {
5744 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
5745 for BLKmode is careful to avoid it. */
5746 excess = (arg->locate.size.constant
5747 - arg_int_size_in_bytes (TREE_TYPE (pval))
5748 + partial);
5749 size_rtx = expand_expr (arg_size_in_bytes (TREE_TYPE (pval)),
5750 NULL_RTX, TYPE_MODE (sizetype),
5751 EXPAND_NORMAL);
5752 }
5753
5754 parm_align = arg->locate.boundary;
5755
5756 /* When an argument is padded down, the block is aligned to
5757 PARM_BOUNDARY, but the actual argument isn't. */
5758 if (targetm.calls.function_arg_padding (arg->mode, TREE_TYPE (pval))
5759 == PAD_DOWNWARD)
5760 {
5761 if (arg->locate.size.var)
5762 parm_align = BITS_PER_UNIT;
5763 else
5764 {
5765 unsigned int excess_align
5766 = known_alignment (excess) * BITS_PER_UNIT;
5767 if (excess_align != 0)
5768 parm_align = MIN (parm_align, excess_align);
5769 }
5770 }
5771
5772 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
5773 {
5774 /* emit_push_insn might not work properly if arg->value and
5775 argblock + arg->locate.offset areas overlap. */
5776 rtx x = arg->value;
5777 poly_int64 i = 0;
5778
5779 if (strip_offset (XEXP (x, 0), &i)
5780 == crtl->args.internal_arg_pointer)
5781 {
5782 /* arg.locate doesn't contain the pretend_args_size offset,
5783 it's part of argblock. Ensure we don't count it in I. */
5784 if (STACK_GROWS_DOWNWARD)
5785 i -= crtl->args.pretend_args_size;
5786 else
5787 i += crtl->args.pretend_args_size;
5788
5789 /* expand_call should ensure this. */
5790 gcc_assert (!arg->locate.offset.var
5791 && arg->locate.size.var == 0);
5792 poly_int64 size_val = rtx_to_poly_int64 (size_rtx);
5793
5794 if (known_eq (arg->locate.offset.constant, i))
5795 {
5796 /* Even though they appear to be at the same location,
5797 if part of the outgoing argument is in registers,
5798 they aren't really at the same location. Check for
5799 this by making sure that the incoming size is the
5800 same as the outgoing size. */
5801 if (maybe_ne (arg->locate.size.constant, size_val))
5802 sibcall_failure = 1;
5803 }
5804 else if (maybe_in_range_p (arg->locate.offset.constant,
5805 i, size_val))
5806 sibcall_failure = 1;
5807 /* Use arg->locate.size.constant instead of size_rtx
5808 because we only care about the part of the argument
5809 on the stack. */
5810 else if (maybe_in_range_p (i, arg->locate.offset.constant,
5811 arg->locate.size.constant))
5812 sibcall_failure = 1;
5813 }
5814 }
5815
5816 if (!CONST_INT_P (size_rtx) || INTVAL (size_rtx) != 0)
5817 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
5818 parm_align, partial, reg, excess, argblock,
5819 ARGS_SIZE_RTX (arg->locate.offset),
5820 reg_parm_stack_space,
5821 ARGS_SIZE_RTX (arg->locate.alignment_pad), false);
5822
5823 /* Unless this is a partially-in-register argument, the argument is now
5824 in the stack.
5825
5826 ??? Unlike the case above, in which we want the actual
5827 address of the data, so that we can load it directly into a
5828 register, here we want the address of the stack slot, so that
5829 it's properly aligned for word-by-word copying or something
5830 like that. It's not clear that this is always correct. */
5831 if (partial == 0)
5832 arg->value = arg->stack_slot;
5833 }
5834
5835 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
5836 {
5837 tree type = TREE_TYPE (arg->tree_value);
5838 arg->parallel_value
5839 = emit_group_load_into_temps (arg->reg, arg->value, type,
5840 int_size_in_bytes (type));
5841 }
5842
5843 /* Mark all slots this store used. */
5844 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
5845 && argblock && ! variable_size && arg->stack)
5846 mark_stack_region_used (lower_bound, upper_bound);
5847
5848 /* Once we have pushed something, pops can't safely
5849 be deferred during the rest of the arguments. */
5850 NO_DEFER_POP;
5851
5852 /* Free any temporary slots made in processing this argument. */
5853 pop_temp_slots ();
5854
5855 return sibcall_failure;
5856 }
5857
5858 /* Nonzero if we do not know how to pass ARG solely in registers. */
5859
5860 bool
5861 must_pass_in_stack_var_size (const function_arg_info &arg)
5862 {
5863 if (!arg.type)
5864 return false;
5865
5866 /* If the type has variable size... */
5867 if (TREE_CODE (TYPE_SIZE (arg.type)) != INTEGER_CST)
5868 return true;
5869
5870 /* If the type is marked as addressable (it is required
5871 to be constructed into the stack)... */
5872 if (TREE_ADDRESSABLE (arg.type))
5873 return true;
5874
5875 return false;
5876 }
5877
5878 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
5879 takes trailing padding of a structure into account. */
5880 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
5881
5882 bool
5883 must_pass_in_stack_var_size_or_pad (const function_arg_info &arg)
5884 {
5885 if (!arg.type)
5886 return false;
5887
5888 /* If the type has variable size... */
5889 if (TREE_CODE (TYPE_SIZE (arg.type)) != INTEGER_CST)
5890 return true;
5891
5892 /* If the type is marked as addressable (it is required
5893 to be constructed into the stack)... */
5894 if (TREE_ADDRESSABLE (arg.type))
5895 return true;
5896
5897 if (TYPE_EMPTY_P (arg.type))
5898 return false;
5899
5900 /* If the padding and mode of the type is such that a copy into
5901 a register would put it into the wrong part of the register. */
5902 if (arg.mode == BLKmode
5903 && int_size_in_bytes (arg.type) % (PARM_BOUNDARY / BITS_PER_UNIT)
5904 && (targetm.calls.function_arg_padding (arg.mode, arg.type)
5905 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
5906 return true;
5907
5908 return false;
5909 }
5910
5911 /* Return true if TYPE must be passed on the stack when passed to
5912 the "..." arguments of a function. */
5913
5914 bool
5915 must_pass_va_arg_in_stack (tree type)
5916 {
5917 function_arg_info arg (type, /*named=*/false);
5918 return targetm.calls.must_pass_in_stack (arg);
5919 }
5920
5921 /* Tell the garbage collector about GTY markers in this source file. */
5922 #include "gt-calls.h"