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Make function.c use function_arg_info internally
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1 /* Expands front end tree to back end RTL for GCC.
2 Copyright (C) 1987-2019 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 /* This file handles the generation of rtl code from tree structure
21 at the level of the function as a whole.
22 It creates the rtl expressions for parameters and auto variables
23 and has full responsibility for allocating stack slots.
24
25 `expand_function_start' is called at the beginning of a function,
26 before the function body is parsed, and `expand_function_end' is
27 called after parsing the body.
28
29 Call `assign_stack_local' to allocate a stack slot for a local variable.
30 This is usually done during the RTL generation for the function body,
31 but it can also be done in the reload pass when a pseudo-register does
32 not get a hard register. */
33
34 #include "config.h"
35 #include "system.h"
36 #include "coretypes.h"
37 #include "backend.h"
38 #include "target.h"
39 #include "rtl.h"
40 #include "tree.h"
41 #include "gimple-expr.h"
42 #include "cfghooks.h"
43 #include "df.h"
44 #include "memmodel.h"
45 #include "tm_p.h"
46 #include "stringpool.h"
47 #include "expmed.h"
48 #include "optabs.h"
49 #include "regs.h"
50 #include "emit-rtl.h"
51 #include "recog.h"
52 #include "rtl-error.h"
53 #include "alias.h"
54 #include "fold-const.h"
55 #include "stor-layout.h"
56 #include "varasm.h"
57 #include "except.h"
58 #include "dojump.h"
59 #include "explow.h"
60 #include "calls.h"
61 #include "expr.h"
62 #include "optabs-tree.h"
63 #include "output.h"
64 #include "langhooks.h"
65 #include "common/common-target.h"
66 #include "gimplify.h"
67 #include "tree-pass.h"
68 #include "cfgrtl.h"
69 #include "cfganal.h"
70 #include "cfgbuild.h"
71 #include "cfgcleanup.h"
72 #include "cfgexpand.h"
73 #include "shrink-wrap.h"
74 #include "toplev.h"
75 #include "rtl-iter.h"
76 #include "tree-dfa.h"
77 #include "tree-ssa.h"
78 #include "stringpool.h"
79 #include "attribs.h"
80 #include "gimple.h"
81 #include "options.h"
82
83 /* So we can assign to cfun in this file. */
84 #undef cfun
85
86 #ifndef STACK_ALIGNMENT_NEEDED
87 #define STACK_ALIGNMENT_NEEDED 1
88 #endif
89
90 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
91
92 /* Round a value to the lowest integer less than it that is a multiple of
93 the required alignment. Avoid using division in case the value is
94 negative. Assume the alignment is a power of two. */
95 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
96
97 /* Similar, but round to the next highest integer that meets the
98 alignment. */
99 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
100
101 /* Nonzero once virtual register instantiation has been done.
102 assign_stack_local uses frame_pointer_rtx when this is nonzero.
103 calls.c:emit_library_call_value_1 uses it to set up
104 post-instantiation libcalls. */
105 int virtuals_instantiated;
106
107 /* Assign unique numbers to labels generated for profiling, debugging, etc. */
108 static GTY(()) int funcdef_no;
109
110 /* These variables hold pointers to functions to create and destroy
111 target specific, per-function data structures. */
112 struct machine_function * (*init_machine_status) (void);
113
114 /* The currently compiled function. */
115 struct function *cfun = 0;
116
117 /* These hashes record the prologue and epilogue insns. */
118
119 struct insn_cache_hasher : ggc_cache_ptr_hash<rtx_def>
120 {
121 static hashval_t hash (rtx x) { return htab_hash_pointer (x); }
122 static bool equal (rtx a, rtx b) { return a == b; }
123 };
124
125 static GTY((cache))
126 hash_table<insn_cache_hasher> *prologue_insn_hash;
127 static GTY((cache))
128 hash_table<insn_cache_hasher> *epilogue_insn_hash;
129 \f
130
131 hash_table<used_type_hasher> *types_used_by_vars_hash = NULL;
132 vec<tree, va_gc> *types_used_by_cur_var_decl;
133
134 /* Forward declarations. */
135
136 static class temp_slot *find_temp_slot_from_address (rtx);
137 static void pad_to_arg_alignment (struct args_size *, int, struct args_size *);
138 static void pad_below (struct args_size *, machine_mode, tree);
139 static void reorder_blocks_1 (rtx_insn *, tree, vec<tree> *);
140 static int all_blocks (tree, tree *);
141 static tree *get_block_vector (tree, int *);
142 extern tree debug_find_var_in_block_tree (tree, tree);
143 /* We always define `record_insns' even if it's not used so that we
144 can always export `prologue_epilogue_contains'. */
145 static void record_insns (rtx_insn *, rtx, hash_table<insn_cache_hasher> **)
146 ATTRIBUTE_UNUSED;
147 static bool contains (const rtx_insn *, hash_table<insn_cache_hasher> *);
148 static void prepare_function_start (void);
149 static void do_clobber_return_reg (rtx, void *);
150 static void do_use_return_reg (rtx, void *);
151
152 \f
153 /* Stack of nested functions. */
154 /* Keep track of the cfun stack. */
155
156 static vec<function *> function_context_stack;
157
158 /* Save the current context for compilation of a nested function.
159 This is called from language-specific code. */
160
161 void
162 push_function_context (void)
163 {
164 if (cfun == 0)
165 allocate_struct_function (NULL, false);
166
167 function_context_stack.safe_push (cfun);
168 set_cfun (NULL);
169 }
170
171 /* Restore the last saved context, at the end of a nested function.
172 This function is called from language-specific code. */
173
174 void
175 pop_function_context (void)
176 {
177 struct function *p = function_context_stack.pop ();
178 set_cfun (p);
179 current_function_decl = p->decl;
180
181 /* Reset variables that have known state during rtx generation. */
182 virtuals_instantiated = 0;
183 generating_concat_p = 1;
184 }
185
186 /* Clear out all parts of the state in F that can safely be discarded
187 after the function has been parsed, but not compiled, to let
188 garbage collection reclaim the memory. */
189
190 void
191 free_after_parsing (struct function *f)
192 {
193 f->language = 0;
194 }
195
196 /* Clear out all parts of the state in F that can safely be discarded
197 after the function has been compiled, to let garbage collection
198 reclaim the memory. */
199
200 void
201 free_after_compilation (struct function *f)
202 {
203 prologue_insn_hash = NULL;
204 epilogue_insn_hash = NULL;
205
206 free (crtl->emit.regno_pointer_align);
207
208 memset (crtl, 0, sizeof (struct rtl_data));
209 f->eh = NULL;
210 f->machine = NULL;
211 f->cfg = NULL;
212 f->curr_properties &= ~PROP_cfg;
213
214 regno_reg_rtx = NULL;
215 }
216 \f
217 /* Return size needed for stack frame based on slots so far allocated.
218 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
219 the caller may have to do that. */
220
221 poly_int64
222 get_frame_size (void)
223 {
224 if (FRAME_GROWS_DOWNWARD)
225 return -frame_offset;
226 else
227 return frame_offset;
228 }
229
230 /* Issue an error message and return TRUE if frame OFFSET overflows in
231 the signed target pointer arithmetics for function FUNC. Otherwise
232 return FALSE. */
233
234 bool
235 frame_offset_overflow (poly_int64 offset, tree func)
236 {
237 poly_uint64 size = FRAME_GROWS_DOWNWARD ? -offset : offset;
238 unsigned HOST_WIDE_INT limit
239 = ((HOST_WIDE_INT_1U << (GET_MODE_BITSIZE (Pmode) - 1))
240 /* Leave room for the fixed part of the frame. */
241 - 64 * UNITS_PER_WORD);
242
243 if (!coeffs_in_range_p (size, 0U, limit))
244 {
245 unsigned HOST_WIDE_INT hwisize;
246 if (size.is_constant (&hwisize))
247 error_at (DECL_SOURCE_LOCATION (func),
248 "total size of local objects %wu exceeds maximum %wu",
249 hwisize, limit);
250 else
251 error_at (DECL_SOURCE_LOCATION (func),
252 "total size of local objects exceeds maximum %wu",
253 limit);
254 return true;
255 }
256
257 return false;
258 }
259
260 /* Return the minimum spill slot alignment for a register of mode MODE. */
261
262 unsigned int
263 spill_slot_alignment (machine_mode mode ATTRIBUTE_UNUSED)
264 {
265 return STACK_SLOT_ALIGNMENT (NULL_TREE, mode, GET_MODE_ALIGNMENT (mode));
266 }
267
268 /* Return stack slot alignment in bits for TYPE and MODE. */
269
270 static unsigned int
271 get_stack_local_alignment (tree type, machine_mode mode)
272 {
273 unsigned int alignment;
274
275 if (mode == BLKmode)
276 alignment = BIGGEST_ALIGNMENT;
277 else
278 alignment = GET_MODE_ALIGNMENT (mode);
279
280 /* Allow the frond-end to (possibly) increase the alignment of this
281 stack slot. */
282 if (! type)
283 type = lang_hooks.types.type_for_mode (mode, 0);
284
285 return STACK_SLOT_ALIGNMENT (type, mode, alignment);
286 }
287
288 /* Determine whether it is possible to fit a stack slot of size SIZE and
289 alignment ALIGNMENT into an area in the stack frame that starts at
290 frame offset START and has a length of LENGTH. If so, store the frame
291 offset to be used for the stack slot in *POFFSET and return true;
292 return false otherwise. This function will extend the frame size when
293 given a start/length pair that lies at the end of the frame. */
294
295 static bool
296 try_fit_stack_local (poly_int64 start, poly_int64 length,
297 poly_int64 size, unsigned int alignment,
298 poly_int64_pod *poffset)
299 {
300 poly_int64 this_frame_offset;
301 int frame_off, frame_alignment, frame_phase;
302
303 /* Calculate how many bytes the start of local variables is off from
304 stack alignment. */
305 frame_alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
306 frame_off = targetm.starting_frame_offset () % frame_alignment;
307 frame_phase = frame_off ? frame_alignment - frame_off : 0;
308
309 /* Round the frame offset to the specified alignment. */
310
311 if (FRAME_GROWS_DOWNWARD)
312 this_frame_offset
313 = (aligned_lower_bound (start + length - size - frame_phase, alignment)
314 + frame_phase);
315 else
316 this_frame_offset
317 = aligned_upper_bound (start - frame_phase, alignment) + frame_phase;
318
319 /* See if it fits. If this space is at the edge of the frame,
320 consider extending the frame to make it fit. Our caller relies on
321 this when allocating a new slot. */
322 if (maybe_lt (this_frame_offset, start))
323 {
324 if (known_eq (frame_offset, start))
325 frame_offset = this_frame_offset;
326 else
327 return false;
328 }
329 else if (maybe_gt (this_frame_offset + size, start + length))
330 {
331 if (known_eq (frame_offset, start + length))
332 frame_offset = this_frame_offset + size;
333 else
334 return false;
335 }
336
337 *poffset = this_frame_offset;
338 return true;
339 }
340
341 /* Create a new frame_space structure describing free space in the stack
342 frame beginning at START and ending at END, and chain it into the
343 function's frame_space_list. */
344
345 static void
346 add_frame_space (poly_int64 start, poly_int64 end)
347 {
348 class frame_space *space = ggc_alloc<frame_space> ();
349 space->next = crtl->frame_space_list;
350 crtl->frame_space_list = space;
351 space->start = start;
352 space->length = end - start;
353 }
354
355 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
356 with machine mode MODE.
357
358 ALIGN controls the amount of alignment for the address of the slot:
359 0 means according to MODE,
360 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
361 -2 means use BITS_PER_UNIT,
362 positive specifies alignment boundary in bits.
363
364 KIND has ASLK_REDUCE_ALIGN bit set if it is OK to reduce
365 alignment and ASLK_RECORD_PAD bit set if we should remember
366 extra space we allocated for alignment purposes. When we are
367 called from assign_stack_temp_for_type, it is not set so we don't
368 track the same stack slot in two independent lists.
369
370 We do not round to stack_boundary here. */
371
372 rtx
373 assign_stack_local_1 (machine_mode mode, poly_int64 size,
374 int align, int kind)
375 {
376 rtx x, addr;
377 poly_int64 bigend_correction = 0;
378 poly_int64 slot_offset = 0, old_frame_offset;
379 unsigned int alignment, alignment_in_bits;
380
381 if (align == 0)
382 {
383 alignment = get_stack_local_alignment (NULL, mode);
384 alignment /= BITS_PER_UNIT;
385 }
386 else if (align == -1)
387 {
388 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
389 size = aligned_upper_bound (size, alignment);
390 }
391 else if (align == -2)
392 alignment = 1; /* BITS_PER_UNIT / BITS_PER_UNIT */
393 else
394 alignment = align / BITS_PER_UNIT;
395
396 alignment_in_bits = alignment * BITS_PER_UNIT;
397
398 /* Ignore alignment if it exceeds MAX_SUPPORTED_STACK_ALIGNMENT. */
399 if (alignment_in_bits > MAX_SUPPORTED_STACK_ALIGNMENT)
400 {
401 alignment_in_bits = MAX_SUPPORTED_STACK_ALIGNMENT;
402 alignment = MAX_SUPPORTED_STACK_ALIGNMENT / BITS_PER_UNIT;
403 }
404
405 if (SUPPORTS_STACK_ALIGNMENT)
406 {
407 if (crtl->stack_alignment_estimated < alignment_in_bits)
408 {
409 if (!crtl->stack_realign_processed)
410 crtl->stack_alignment_estimated = alignment_in_bits;
411 else
412 {
413 /* If stack is realigned and stack alignment value
414 hasn't been finalized, it is OK not to increase
415 stack_alignment_estimated. The bigger alignment
416 requirement is recorded in stack_alignment_needed
417 below. */
418 gcc_assert (!crtl->stack_realign_finalized);
419 if (!crtl->stack_realign_needed)
420 {
421 /* It is OK to reduce the alignment as long as the
422 requested size is 0 or the estimated stack
423 alignment >= mode alignment. */
424 gcc_assert ((kind & ASLK_REDUCE_ALIGN)
425 || known_eq (size, 0)
426 || (crtl->stack_alignment_estimated
427 >= GET_MODE_ALIGNMENT (mode)));
428 alignment_in_bits = crtl->stack_alignment_estimated;
429 alignment = alignment_in_bits / BITS_PER_UNIT;
430 }
431 }
432 }
433 }
434
435 if (crtl->stack_alignment_needed < alignment_in_bits)
436 crtl->stack_alignment_needed = alignment_in_bits;
437 if (crtl->max_used_stack_slot_alignment < alignment_in_bits)
438 crtl->max_used_stack_slot_alignment = alignment_in_bits;
439
440 if (mode != BLKmode || maybe_ne (size, 0))
441 {
442 if (kind & ASLK_RECORD_PAD)
443 {
444 class frame_space **psp;
445
446 for (psp = &crtl->frame_space_list; *psp; psp = &(*psp)->next)
447 {
448 class frame_space *space = *psp;
449 if (!try_fit_stack_local (space->start, space->length, size,
450 alignment, &slot_offset))
451 continue;
452 *psp = space->next;
453 if (known_gt (slot_offset, space->start))
454 add_frame_space (space->start, slot_offset);
455 if (known_lt (slot_offset + size, space->start + space->length))
456 add_frame_space (slot_offset + size,
457 space->start + space->length);
458 goto found_space;
459 }
460 }
461 }
462 else if (!STACK_ALIGNMENT_NEEDED)
463 {
464 slot_offset = frame_offset;
465 goto found_space;
466 }
467
468 old_frame_offset = frame_offset;
469
470 if (FRAME_GROWS_DOWNWARD)
471 {
472 frame_offset -= size;
473 try_fit_stack_local (frame_offset, size, size, alignment, &slot_offset);
474
475 if (kind & ASLK_RECORD_PAD)
476 {
477 if (known_gt (slot_offset, frame_offset))
478 add_frame_space (frame_offset, slot_offset);
479 if (known_lt (slot_offset + size, old_frame_offset))
480 add_frame_space (slot_offset + size, old_frame_offset);
481 }
482 }
483 else
484 {
485 frame_offset += size;
486 try_fit_stack_local (old_frame_offset, size, size, alignment, &slot_offset);
487
488 if (kind & ASLK_RECORD_PAD)
489 {
490 if (known_gt (slot_offset, old_frame_offset))
491 add_frame_space (old_frame_offset, slot_offset);
492 if (known_lt (slot_offset + size, frame_offset))
493 add_frame_space (slot_offset + size, frame_offset);
494 }
495 }
496
497 found_space:
498 /* On a big-endian machine, if we are allocating more space than we will use,
499 use the least significant bytes of those that are allocated. */
500 if (mode != BLKmode)
501 {
502 /* The slot size can sometimes be smaller than the mode size;
503 e.g. the rs6000 port allocates slots with a vector mode
504 that have the size of only one element. However, the slot
505 size must always be ordered wrt to the mode size, in the
506 same way as for a subreg. */
507 gcc_checking_assert (ordered_p (GET_MODE_SIZE (mode), size));
508 if (BYTES_BIG_ENDIAN && maybe_lt (GET_MODE_SIZE (mode), size))
509 bigend_correction = size - GET_MODE_SIZE (mode);
510 }
511
512 /* If we have already instantiated virtual registers, return the actual
513 address relative to the frame pointer. */
514 if (virtuals_instantiated)
515 addr = plus_constant (Pmode, frame_pointer_rtx,
516 trunc_int_for_mode
517 (slot_offset + bigend_correction
518 + targetm.starting_frame_offset (), Pmode));
519 else
520 addr = plus_constant (Pmode, virtual_stack_vars_rtx,
521 trunc_int_for_mode
522 (slot_offset + bigend_correction,
523 Pmode));
524
525 x = gen_rtx_MEM (mode, addr);
526 set_mem_align (x, alignment_in_bits);
527 MEM_NOTRAP_P (x) = 1;
528
529 vec_safe_push (stack_slot_list, x);
530
531 if (frame_offset_overflow (frame_offset, current_function_decl))
532 frame_offset = 0;
533
534 return x;
535 }
536
537 /* Wrap up assign_stack_local_1 with last parameter as false. */
538
539 rtx
540 assign_stack_local (machine_mode mode, poly_int64 size, int align)
541 {
542 return assign_stack_local_1 (mode, size, align, ASLK_RECORD_PAD);
543 }
544 \f
545 /* In order to evaluate some expressions, such as function calls returning
546 structures in memory, we need to temporarily allocate stack locations.
547 We record each allocated temporary in the following structure.
548
549 Associated with each temporary slot is a nesting level. When we pop up
550 one level, all temporaries associated with the previous level are freed.
551 Normally, all temporaries are freed after the execution of the statement
552 in which they were created. However, if we are inside a ({...}) grouping,
553 the result may be in a temporary and hence must be preserved. If the
554 result could be in a temporary, we preserve it if we can determine which
555 one it is in. If we cannot determine which temporary may contain the
556 result, all temporaries are preserved. A temporary is preserved by
557 pretending it was allocated at the previous nesting level. */
558
559 class GTY(()) temp_slot {
560 public:
561 /* Points to next temporary slot. */
562 class temp_slot *next;
563 /* Points to previous temporary slot. */
564 class temp_slot *prev;
565 /* The rtx to used to reference the slot. */
566 rtx slot;
567 /* The size, in units, of the slot. */
568 poly_int64 size;
569 /* The type of the object in the slot, or zero if it doesn't correspond
570 to a type. We use this to determine whether a slot can be reused.
571 It can be reused if objects of the type of the new slot will always
572 conflict with objects of the type of the old slot. */
573 tree type;
574 /* The alignment (in bits) of the slot. */
575 unsigned int align;
576 /* Nonzero if this temporary is currently in use. */
577 char in_use;
578 /* Nesting level at which this slot is being used. */
579 int level;
580 /* The offset of the slot from the frame_pointer, including extra space
581 for alignment. This info is for combine_temp_slots. */
582 poly_int64 base_offset;
583 /* The size of the slot, including extra space for alignment. This
584 info is for combine_temp_slots. */
585 poly_int64 full_size;
586 };
587
588 /* Entry for the below hash table. */
589 struct GTY((for_user)) temp_slot_address_entry {
590 hashval_t hash;
591 rtx address;
592 class temp_slot *temp_slot;
593 };
594
595 struct temp_address_hasher : ggc_ptr_hash<temp_slot_address_entry>
596 {
597 static hashval_t hash (temp_slot_address_entry *);
598 static bool equal (temp_slot_address_entry *, temp_slot_address_entry *);
599 };
600
601 /* A table of addresses that represent a stack slot. The table is a mapping
602 from address RTXen to a temp slot. */
603 static GTY(()) hash_table<temp_address_hasher> *temp_slot_address_table;
604 static size_t n_temp_slots_in_use;
605
606 /* Removes temporary slot TEMP from LIST. */
607
608 static void
609 cut_slot_from_list (class temp_slot *temp, class temp_slot **list)
610 {
611 if (temp->next)
612 temp->next->prev = temp->prev;
613 if (temp->prev)
614 temp->prev->next = temp->next;
615 else
616 *list = temp->next;
617
618 temp->prev = temp->next = NULL;
619 }
620
621 /* Inserts temporary slot TEMP to LIST. */
622
623 static void
624 insert_slot_to_list (class temp_slot *temp, class temp_slot **list)
625 {
626 temp->next = *list;
627 if (*list)
628 (*list)->prev = temp;
629 temp->prev = NULL;
630 *list = temp;
631 }
632
633 /* Returns the list of used temp slots at LEVEL. */
634
635 static class temp_slot **
636 temp_slots_at_level (int level)
637 {
638 if (level >= (int) vec_safe_length (used_temp_slots))
639 vec_safe_grow_cleared (used_temp_slots, level + 1);
640
641 return &(*used_temp_slots)[level];
642 }
643
644 /* Returns the maximal temporary slot level. */
645
646 static int
647 max_slot_level (void)
648 {
649 if (!used_temp_slots)
650 return -1;
651
652 return used_temp_slots->length () - 1;
653 }
654
655 /* Moves temporary slot TEMP to LEVEL. */
656
657 static void
658 move_slot_to_level (class temp_slot *temp, int level)
659 {
660 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
661 insert_slot_to_list (temp, temp_slots_at_level (level));
662 temp->level = level;
663 }
664
665 /* Make temporary slot TEMP available. */
666
667 static void
668 make_slot_available (class temp_slot *temp)
669 {
670 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
671 insert_slot_to_list (temp, &avail_temp_slots);
672 temp->in_use = 0;
673 temp->level = -1;
674 n_temp_slots_in_use--;
675 }
676
677 /* Compute the hash value for an address -> temp slot mapping.
678 The value is cached on the mapping entry. */
679 static hashval_t
680 temp_slot_address_compute_hash (struct temp_slot_address_entry *t)
681 {
682 int do_not_record = 0;
683 return hash_rtx (t->address, GET_MODE (t->address),
684 &do_not_record, NULL, false);
685 }
686
687 /* Return the hash value for an address -> temp slot mapping. */
688 hashval_t
689 temp_address_hasher::hash (temp_slot_address_entry *t)
690 {
691 return t->hash;
692 }
693
694 /* Compare two address -> temp slot mapping entries. */
695 bool
696 temp_address_hasher::equal (temp_slot_address_entry *t1,
697 temp_slot_address_entry *t2)
698 {
699 return exp_equiv_p (t1->address, t2->address, 0, true);
700 }
701
702 /* Add ADDRESS as an alias of TEMP_SLOT to the addess -> temp slot mapping. */
703 static void
704 insert_temp_slot_address (rtx address, class temp_slot *temp_slot)
705 {
706 struct temp_slot_address_entry *t = ggc_alloc<temp_slot_address_entry> ();
707 t->address = copy_rtx (address);
708 t->temp_slot = temp_slot;
709 t->hash = temp_slot_address_compute_hash (t);
710 *temp_slot_address_table->find_slot_with_hash (t, t->hash, INSERT) = t;
711 }
712
713 /* Remove an address -> temp slot mapping entry if the temp slot is
714 not in use anymore. Callback for remove_unused_temp_slot_addresses. */
715 int
716 remove_unused_temp_slot_addresses_1 (temp_slot_address_entry **slot, void *)
717 {
718 const struct temp_slot_address_entry *t = *slot;
719 if (! t->temp_slot->in_use)
720 temp_slot_address_table->clear_slot (slot);
721 return 1;
722 }
723
724 /* Remove all mappings of addresses to unused temp slots. */
725 static void
726 remove_unused_temp_slot_addresses (void)
727 {
728 /* Use quicker clearing if there aren't any active temp slots. */
729 if (n_temp_slots_in_use)
730 temp_slot_address_table->traverse
731 <void *, remove_unused_temp_slot_addresses_1> (NULL);
732 else
733 temp_slot_address_table->empty ();
734 }
735
736 /* Find the temp slot corresponding to the object at address X. */
737
738 static class temp_slot *
739 find_temp_slot_from_address (rtx x)
740 {
741 class temp_slot *p;
742 struct temp_slot_address_entry tmp, *t;
743
744 /* First try the easy way:
745 See if X exists in the address -> temp slot mapping. */
746 tmp.address = x;
747 tmp.temp_slot = NULL;
748 tmp.hash = temp_slot_address_compute_hash (&tmp);
749 t = temp_slot_address_table->find_with_hash (&tmp, tmp.hash);
750 if (t)
751 return t->temp_slot;
752
753 /* If we have a sum involving a register, see if it points to a temp
754 slot. */
755 if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 0))
756 && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
757 return p;
758 else if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 1))
759 && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
760 return p;
761
762 /* Last resort: Address is a virtual stack var address. */
763 poly_int64 offset;
764 if (strip_offset (x, &offset) == virtual_stack_vars_rtx)
765 {
766 int i;
767 for (i = max_slot_level (); i >= 0; i--)
768 for (p = *temp_slots_at_level (i); p; p = p->next)
769 if (known_in_range_p (offset, p->base_offset, p->full_size))
770 return p;
771 }
772
773 return NULL;
774 }
775 \f
776 /* Allocate a temporary stack slot and record it for possible later
777 reuse.
778
779 MODE is the machine mode to be given to the returned rtx.
780
781 SIZE is the size in units of the space required. We do no rounding here
782 since assign_stack_local will do any required rounding.
783
784 TYPE is the type that will be used for the stack slot. */
785
786 rtx
787 assign_stack_temp_for_type (machine_mode mode, poly_int64 size, tree type)
788 {
789 unsigned int align;
790 class temp_slot *p, *best_p = 0, *selected = NULL, **pp;
791 rtx slot;
792
793 gcc_assert (known_size_p (size));
794
795 align = get_stack_local_alignment (type, mode);
796
797 /* Try to find an available, already-allocated temporary of the proper
798 mode which meets the size and alignment requirements. Choose the
799 smallest one with the closest alignment.
800
801 If assign_stack_temp is called outside of the tree->rtl expansion,
802 we cannot reuse the stack slots (that may still refer to
803 VIRTUAL_STACK_VARS_REGNUM). */
804 if (!virtuals_instantiated)
805 {
806 for (p = avail_temp_slots; p; p = p->next)
807 {
808 if (p->align >= align
809 && known_ge (p->size, size)
810 && GET_MODE (p->slot) == mode
811 && objects_must_conflict_p (p->type, type)
812 && (best_p == 0
813 || (known_eq (best_p->size, p->size)
814 ? best_p->align > p->align
815 : known_ge (best_p->size, p->size))))
816 {
817 if (p->align == align && known_eq (p->size, size))
818 {
819 selected = p;
820 cut_slot_from_list (selected, &avail_temp_slots);
821 best_p = 0;
822 break;
823 }
824 best_p = p;
825 }
826 }
827 }
828
829 /* Make our best, if any, the one to use. */
830 if (best_p)
831 {
832 selected = best_p;
833 cut_slot_from_list (selected, &avail_temp_slots);
834
835 /* If there are enough aligned bytes left over, make them into a new
836 temp_slot so that the extra bytes don't get wasted. Do this only
837 for BLKmode slots, so that we can be sure of the alignment. */
838 if (GET_MODE (best_p->slot) == BLKmode)
839 {
840 int alignment = best_p->align / BITS_PER_UNIT;
841 poly_int64 rounded_size = aligned_upper_bound (size, alignment);
842
843 if (known_ge (best_p->size - rounded_size, alignment))
844 {
845 p = ggc_alloc<temp_slot> ();
846 p->in_use = 0;
847 p->size = best_p->size - rounded_size;
848 p->base_offset = best_p->base_offset + rounded_size;
849 p->full_size = best_p->full_size - rounded_size;
850 p->slot = adjust_address_nv (best_p->slot, BLKmode, rounded_size);
851 p->align = best_p->align;
852 p->type = best_p->type;
853 insert_slot_to_list (p, &avail_temp_slots);
854
855 vec_safe_push (stack_slot_list, p->slot);
856
857 best_p->size = rounded_size;
858 best_p->full_size = rounded_size;
859 }
860 }
861 }
862
863 /* If we still didn't find one, make a new temporary. */
864 if (selected == 0)
865 {
866 poly_int64 frame_offset_old = frame_offset;
867
868 p = ggc_alloc<temp_slot> ();
869
870 /* We are passing an explicit alignment request to assign_stack_local.
871 One side effect of that is assign_stack_local will not round SIZE
872 to ensure the frame offset remains suitably aligned.
873
874 So for requests which depended on the rounding of SIZE, we go ahead
875 and round it now. We also make sure ALIGNMENT is at least
876 BIGGEST_ALIGNMENT. */
877 gcc_assert (mode != BLKmode || align == BIGGEST_ALIGNMENT);
878 p->slot = assign_stack_local_1 (mode,
879 (mode == BLKmode
880 ? aligned_upper_bound (size,
881 (int) align
882 / BITS_PER_UNIT)
883 : size),
884 align, 0);
885
886 p->align = align;
887
888 /* The following slot size computation is necessary because we don't
889 know the actual size of the temporary slot until assign_stack_local
890 has performed all the frame alignment and size rounding for the
891 requested temporary. Note that extra space added for alignment
892 can be either above or below this stack slot depending on which
893 way the frame grows. We include the extra space if and only if it
894 is above this slot. */
895 if (FRAME_GROWS_DOWNWARD)
896 p->size = frame_offset_old - frame_offset;
897 else
898 p->size = size;
899
900 /* Now define the fields used by combine_temp_slots. */
901 if (FRAME_GROWS_DOWNWARD)
902 {
903 p->base_offset = frame_offset;
904 p->full_size = frame_offset_old - frame_offset;
905 }
906 else
907 {
908 p->base_offset = frame_offset_old;
909 p->full_size = frame_offset - frame_offset_old;
910 }
911
912 selected = p;
913 }
914
915 p = selected;
916 p->in_use = 1;
917 p->type = type;
918 p->level = temp_slot_level;
919 n_temp_slots_in_use++;
920
921 pp = temp_slots_at_level (p->level);
922 insert_slot_to_list (p, pp);
923 insert_temp_slot_address (XEXP (p->slot, 0), p);
924
925 /* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
926 slot = gen_rtx_MEM (mode, XEXP (p->slot, 0));
927 vec_safe_push (stack_slot_list, slot);
928
929 /* If we know the alias set for the memory that will be used, use
930 it. If there's no TYPE, then we don't know anything about the
931 alias set for the memory. */
932 set_mem_alias_set (slot, type ? get_alias_set (type) : 0);
933 set_mem_align (slot, align);
934
935 /* If a type is specified, set the relevant flags. */
936 if (type != 0)
937 MEM_VOLATILE_P (slot) = TYPE_VOLATILE (type);
938 MEM_NOTRAP_P (slot) = 1;
939
940 return slot;
941 }
942
943 /* Allocate a temporary stack slot and record it for possible later
944 reuse. First two arguments are same as in preceding function. */
945
946 rtx
947 assign_stack_temp (machine_mode mode, poly_int64 size)
948 {
949 return assign_stack_temp_for_type (mode, size, NULL_TREE);
950 }
951 \f
952 /* Assign a temporary.
953 If TYPE_OR_DECL is a decl, then we are doing it on behalf of the decl
954 and so that should be used in error messages. In either case, we
955 allocate of the given type.
956 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
957 it is 0 if a register is OK.
958 DONT_PROMOTE is 1 if we should not promote values in register
959 to wider modes. */
960
961 rtx
962 assign_temp (tree type_or_decl, int memory_required,
963 int dont_promote ATTRIBUTE_UNUSED)
964 {
965 tree type, decl;
966 machine_mode mode;
967 #ifdef PROMOTE_MODE
968 int unsignedp;
969 #endif
970
971 if (DECL_P (type_or_decl))
972 decl = type_or_decl, type = TREE_TYPE (decl);
973 else
974 decl = NULL, type = type_or_decl;
975
976 mode = TYPE_MODE (type);
977 #ifdef PROMOTE_MODE
978 unsignedp = TYPE_UNSIGNED (type);
979 #endif
980
981 /* Allocating temporaries of TREE_ADDRESSABLE type must be done in the front
982 end. See also create_tmp_var for the gimplification-time check. */
983 gcc_assert (!TREE_ADDRESSABLE (type) && COMPLETE_TYPE_P (type));
984
985 if (mode == BLKmode || memory_required)
986 {
987 poly_int64 size;
988 rtx tmp;
989
990 /* Unfortunately, we don't yet know how to allocate variable-sized
991 temporaries. However, sometimes we can find a fixed upper limit on
992 the size, so try that instead. */
993 if (!poly_int_tree_p (TYPE_SIZE_UNIT (type), &size))
994 size = max_int_size_in_bytes (type);
995
996 /* Zero sized arrays are a GNU C extension. Set size to 1 to avoid
997 problems with allocating the stack space. */
998 if (known_eq (size, 0))
999 size = 1;
1000
1001 /* The size of the temporary may be too large to fit into an integer. */
1002 /* ??? Not sure this should happen except for user silliness, so limit
1003 this to things that aren't compiler-generated temporaries. The
1004 rest of the time we'll die in assign_stack_temp_for_type. */
1005 if (decl
1006 && !known_size_p (size)
1007 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST)
1008 {
1009 error ("size of variable %q+D is too large", decl);
1010 size = 1;
1011 }
1012
1013 tmp = assign_stack_temp_for_type (mode, size, type);
1014 return tmp;
1015 }
1016
1017 #ifdef PROMOTE_MODE
1018 if (! dont_promote)
1019 mode = promote_mode (type, mode, &unsignedp);
1020 #endif
1021
1022 return gen_reg_rtx (mode);
1023 }
1024 \f
1025 /* Combine temporary stack slots which are adjacent on the stack.
1026
1027 This allows for better use of already allocated stack space. This is only
1028 done for BLKmode slots because we can be sure that we won't have alignment
1029 problems in this case. */
1030
1031 static void
1032 combine_temp_slots (void)
1033 {
1034 class temp_slot *p, *q, *next, *next_q;
1035 int num_slots;
1036
1037 /* We can't combine slots, because the information about which slot
1038 is in which alias set will be lost. */
1039 if (flag_strict_aliasing)
1040 return;
1041
1042 /* If there are a lot of temp slots, don't do anything unless
1043 high levels of optimization. */
1044 if (! flag_expensive_optimizations)
1045 for (p = avail_temp_slots, num_slots = 0; p; p = p->next, num_slots++)
1046 if (num_slots > 100 || (num_slots > 10 && optimize == 0))
1047 return;
1048
1049 for (p = avail_temp_slots; p; p = next)
1050 {
1051 int delete_p = 0;
1052
1053 next = p->next;
1054
1055 if (GET_MODE (p->slot) != BLKmode)
1056 continue;
1057
1058 for (q = p->next; q; q = next_q)
1059 {
1060 int delete_q = 0;
1061
1062 next_q = q->next;
1063
1064 if (GET_MODE (q->slot) != BLKmode)
1065 continue;
1066
1067 if (known_eq (p->base_offset + p->full_size, q->base_offset))
1068 {
1069 /* Q comes after P; combine Q into P. */
1070 p->size += q->size;
1071 p->full_size += q->full_size;
1072 delete_q = 1;
1073 }
1074 else if (known_eq (q->base_offset + q->full_size, p->base_offset))
1075 {
1076 /* P comes after Q; combine P into Q. */
1077 q->size += p->size;
1078 q->full_size += p->full_size;
1079 delete_p = 1;
1080 break;
1081 }
1082 if (delete_q)
1083 cut_slot_from_list (q, &avail_temp_slots);
1084 }
1085
1086 /* Either delete P or advance past it. */
1087 if (delete_p)
1088 cut_slot_from_list (p, &avail_temp_slots);
1089 }
1090 }
1091 \f
1092 /* Indicate that NEW_RTX is an alternate way of referring to the temp
1093 slot that previously was known by OLD_RTX. */
1094
1095 void
1096 update_temp_slot_address (rtx old_rtx, rtx new_rtx)
1097 {
1098 class temp_slot *p;
1099
1100 if (rtx_equal_p (old_rtx, new_rtx))
1101 return;
1102
1103 p = find_temp_slot_from_address (old_rtx);
1104
1105 /* If we didn't find one, see if both OLD_RTX is a PLUS. If so, and
1106 NEW_RTX is a register, see if one operand of the PLUS is a
1107 temporary location. If so, NEW_RTX points into it. Otherwise,
1108 if both OLD_RTX and NEW_RTX are a PLUS and if there is a register
1109 in common between them. If so, try a recursive call on those
1110 values. */
1111 if (p == 0)
1112 {
1113 if (GET_CODE (old_rtx) != PLUS)
1114 return;
1115
1116 if (REG_P (new_rtx))
1117 {
1118 update_temp_slot_address (XEXP (old_rtx, 0), new_rtx);
1119 update_temp_slot_address (XEXP (old_rtx, 1), new_rtx);
1120 return;
1121 }
1122 else if (GET_CODE (new_rtx) != PLUS)
1123 return;
1124
1125 if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 0)))
1126 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 1));
1127 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 0)))
1128 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 1));
1129 else if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 1)))
1130 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 0));
1131 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 1)))
1132 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 0));
1133
1134 return;
1135 }
1136
1137 /* Otherwise add an alias for the temp's address. */
1138 insert_temp_slot_address (new_rtx, p);
1139 }
1140
1141 /* If X could be a reference to a temporary slot, mark that slot as
1142 belonging to the to one level higher than the current level. If X
1143 matched one of our slots, just mark that one. Otherwise, we can't
1144 easily predict which it is, so upgrade all of them.
1145
1146 This is called when an ({...}) construct occurs and a statement
1147 returns a value in memory. */
1148
1149 void
1150 preserve_temp_slots (rtx x)
1151 {
1152 class temp_slot *p = 0, *next;
1153
1154 if (x == 0)
1155 return;
1156
1157 /* If X is a register that is being used as a pointer, see if we have
1158 a temporary slot we know it points to. */
1159 if (REG_P (x) && REG_POINTER (x))
1160 p = find_temp_slot_from_address (x);
1161
1162 /* If X is not in memory or is at a constant address, it cannot be in
1163 a temporary slot. */
1164 if (p == 0 && (!MEM_P (x) || CONSTANT_P (XEXP (x, 0))))
1165 return;
1166
1167 /* First see if we can find a match. */
1168 if (p == 0)
1169 p = find_temp_slot_from_address (XEXP (x, 0));
1170
1171 if (p != 0)
1172 {
1173 if (p->level == temp_slot_level)
1174 move_slot_to_level (p, temp_slot_level - 1);
1175 return;
1176 }
1177
1178 /* Otherwise, preserve all non-kept slots at this level. */
1179 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1180 {
1181 next = p->next;
1182 move_slot_to_level (p, temp_slot_level - 1);
1183 }
1184 }
1185
1186 /* Free all temporaries used so far. This is normally called at the
1187 end of generating code for a statement. */
1188
1189 void
1190 free_temp_slots (void)
1191 {
1192 class temp_slot *p, *next;
1193 bool some_available = false;
1194
1195 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1196 {
1197 next = p->next;
1198 make_slot_available (p);
1199 some_available = true;
1200 }
1201
1202 if (some_available)
1203 {
1204 remove_unused_temp_slot_addresses ();
1205 combine_temp_slots ();
1206 }
1207 }
1208
1209 /* Push deeper into the nesting level for stack temporaries. */
1210
1211 void
1212 push_temp_slots (void)
1213 {
1214 temp_slot_level++;
1215 }
1216
1217 /* Pop a temporary nesting level. All slots in use in the current level
1218 are freed. */
1219
1220 void
1221 pop_temp_slots (void)
1222 {
1223 free_temp_slots ();
1224 temp_slot_level--;
1225 }
1226
1227 /* Initialize temporary slots. */
1228
1229 void
1230 init_temp_slots (void)
1231 {
1232 /* We have not allocated any temporaries yet. */
1233 avail_temp_slots = 0;
1234 vec_alloc (used_temp_slots, 0);
1235 temp_slot_level = 0;
1236 n_temp_slots_in_use = 0;
1237
1238 /* Set up the table to map addresses to temp slots. */
1239 if (! temp_slot_address_table)
1240 temp_slot_address_table = hash_table<temp_address_hasher>::create_ggc (32);
1241 else
1242 temp_slot_address_table->empty ();
1243 }
1244 \f
1245 /* Functions and data structures to keep track of the values hard regs
1246 had at the start of the function. */
1247
1248 /* Private type used by get_hard_reg_initial_reg, get_hard_reg_initial_val,
1249 and has_hard_reg_initial_val.. */
1250 struct GTY(()) initial_value_pair {
1251 rtx hard_reg;
1252 rtx pseudo;
1253 };
1254 /* ??? This could be a VEC but there is currently no way to define an
1255 opaque VEC type. This could be worked around by defining struct
1256 initial_value_pair in function.h. */
1257 struct GTY(()) initial_value_struct {
1258 int num_entries;
1259 int max_entries;
1260 initial_value_pair * GTY ((length ("%h.num_entries"))) entries;
1261 };
1262
1263 /* If a pseudo represents an initial hard reg (or expression), return
1264 it, else return NULL_RTX. */
1265
1266 rtx
1267 get_hard_reg_initial_reg (rtx reg)
1268 {
1269 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1270 int i;
1271
1272 if (ivs == 0)
1273 return NULL_RTX;
1274
1275 for (i = 0; i < ivs->num_entries; i++)
1276 if (rtx_equal_p (ivs->entries[i].pseudo, reg))
1277 return ivs->entries[i].hard_reg;
1278
1279 return NULL_RTX;
1280 }
1281
1282 /* Make sure that there's a pseudo register of mode MODE that stores the
1283 initial value of hard register REGNO. Return an rtx for such a pseudo. */
1284
1285 rtx
1286 get_hard_reg_initial_val (machine_mode mode, unsigned int regno)
1287 {
1288 struct initial_value_struct *ivs;
1289 rtx rv;
1290
1291 rv = has_hard_reg_initial_val (mode, regno);
1292 if (rv)
1293 return rv;
1294
1295 ivs = crtl->hard_reg_initial_vals;
1296 if (ivs == 0)
1297 {
1298 ivs = ggc_alloc<initial_value_struct> ();
1299 ivs->num_entries = 0;
1300 ivs->max_entries = 5;
1301 ivs->entries = ggc_vec_alloc<initial_value_pair> (5);
1302 crtl->hard_reg_initial_vals = ivs;
1303 }
1304
1305 if (ivs->num_entries >= ivs->max_entries)
1306 {
1307 ivs->max_entries += 5;
1308 ivs->entries = GGC_RESIZEVEC (initial_value_pair, ivs->entries,
1309 ivs->max_entries);
1310 }
1311
1312 ivs->entries[ivs->num_entries].hard_reg = gen_rtx_REG (mode, regno);
1313 ivs->entries[ivs->num_entries].pseudo = gen_reg_rtx (mode);
1314
1315 return ivs->entries[ivs->num_entries++].pseudo;
1316 }
1317
1318 /* See if get_hard_reg_initial_val has been used to create a pseudo
1319 for the initial value of hard register REGNO in mode MODE. Return
1320 the associated pseudo if so, otherwise return NULL. */
1321
1322 rtx
1323 has_hard_reg_initial_val (machine_mode mode, unsigned int regno)
1324 {
1325 struct initial_value_struct *ivs;
1326 int i;
1327
1328 ivs = crtl->hard_reg_initial_vals;
1329 if (ivs != 0)
1330 for (i = 0; i < ivs->num_entries; i++)
1331 if (GET_MODE (ivs->entries[i].hard_reg) == mode
1332 && REGNO (ivs->entries[i].hard_reg) == regno)
1333 return ivs->entries[i].pseudo;
1334
1335 return NULL_RTX;
1336 }
1337
1338 unsigned int
1339 emit_initial_value_sets (void)
1340 {
1341 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1342 int i;
1343 rtx_insn *seq;
1344
1345 if (ivs == 0)
1346 return 0;
1347
1348 start_sequence ();
1349 for (i = 0; i < ivs->num_entries; i++)
1350 emit_move_insn (ivs->entries[i].pseudo, ivs->entries[i].hard_reg);
1351 seq = get_insns ();
1352 end_sequence ();
1353
1354 emit_insn_at_entry (seq);
1355 return 0;
1356 }
1357
1358 /* Return the hardreg-pseudoreg initial values pair entry I and
1359 TRUE if I is a valid entry, or FALSE if I is not a valid entry. */
1360 bool
1361 initial_value_entry (int i, rtx *hreg, rtx *preg)
1362 {
1363 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1364 if (!ivs || i >= ivs->num_entries)
1365 return false;
1366
1367 *hreg = ivs->entries[i].hard_reg;
1368 *preg = ivs->entries[i].pseudo;
1369 return true;
1370 }
1371 \f
1372 /* These routines are responsible for converting virtual register references
1373 to the actual hard register references once RTL generation is complete.
1374
1375 The following four variables are used for communication between the
1376 routines. They contain the offsets of the virtual registers from their
1377 respective hard registers. */
1378
1379 static poly_int64 in_arg_offset;
1380 static poly_int64 var_offset;
1381 static poly_int64 dynamic_offset;
1382 static poly_int64 out_arg_offset;
1383 static poly_int64 cfa_offset;
1384
1385 /* In most machines, the stack pointer register is equivalent to the bottom
1386 of the stack. */
1387
1388 #ifndef STACK_POINTER_OFFSET
1389 #define STACK_POINTER_OFFSET 0
1390 #endif
1391
1392 #if defined (REG_PARM_STACK_SPACE) && !defined (INCOMING_REG_PARM_STACK_SPACE)
1393 #define INCOMING_REG_PARM_STACK_SPACE REG_PARM_STACK_SPACE
1394 #endif
1395
1396 /* If not defined, pick an appropriate default for the offset of dynamically
1397 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
1398 INCOMING_REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
1399
1400 #ifndef STACK_DYNAMIC_OFFSET
1401
1402 /* The bottom of the stack points to the actual arguments. If
1403 REG_PARM_STACK_SPACE is defined, this includes the space for the register
1404 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
1405 stack space for register parameters is not pushed by the caller, but
1406 rather part of the fixed stack areas and hence not included in
1407 `crtl->outgoing_args_size'. Nevertheless, we must allow
1408 for it when allocating stack dynamic objects. */
1409
1410 #ifdef INCOMING_REG_PARM_STACK_SPACE
1411 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1412 ((ACCUMULATE_OUTGOING_ARGS \
1413 ? (crtl->outgoing_args_size \
1414 + (OUTGOING_REG_PARM_STACK_SPACE ((!(FNDECL) ? NULL_TREE : TREE_TYPE (FNDECL))) ? 0 \
1415 : INCOMING_REG_PARM_STACK_SPACE (FNDECL))) \
1416 : 0) + (STACK_POINTER_OFFSET))
1417 #else
1418 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1419 ((ACCUMULATE_OUTGOING_ARGS ? crtl->outgoing_args_size : poly_int64 (0)) \
1420 + (STACK_POINTER_OFFSET))
1421 #endif
1422 #endif
1423
1424 \f
1425 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
1426 is a virtual register, return the equivalent hard register and set the
1427 offset indirectly through the pointer. Otherwise, return 0. */
1428
1429 static rtx
1430 instantiate_new_reg (rtx x, poly_int64_pod *poffset)
1431 {
1432 rtx new_rtx;
1433 poly_int64 offset;
1434
1435 if (x == virtual_incoming_args_rtx)
1436 {
1437 if (stack_realign_drap)
1438 {
1439 /* Replace virtual_incoming_args_rtx with internal arg
1440 pointer if DRAP is used to realign stack. */
1441 new_rtx = crtl->args.internal_arg_pointer;
1442 offset = 0;
1443 }
1444 else
1445 new_rtx = arg_pointer_rtx, offset = in_arg_offset;
1446 }
1447 else if (x == virtual_stack_vars_rtx)
1448 new_rtx = frame_pointer_rtx, offset = var_offset;
1449 else if (x == virtual_stack_dynamic_rtx)
1450 new_rtx = stack_pointer_rtx, offset = dynamic_offset;
1451 else if (x == virtual_outgoing_args_rtx)
1452 new_rtx = stack_pointer_rtx, offset = out_arg_offset;
1453 else if (x == virtual_cfa_rtx)
1454 {
1455 #ifdef FRAME_POINTER_CFA_OFFSET
1456 new_rtx = frame_pointer_rtx;
1457 #else
1458 new_rtx = arg_pointer_rtx;
1459 #endif
1460 offset = cfa_offset;
1461 }
1462 else if (x == virtual_preferred_stack_boundary_rtx)
1463 {
1464 new_rtx = GEN_INT (crtl->preferred_stack_boundary / BITS_PER_UNIT);
1465 offset = 0;
1466 }
1467 else
1468 return NULL_RTX;
1469
1470 *poffset = offset;
1471 return new_rtx;
1472 }
1473
1474 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1475 registers present inside of *LOC. The expression is simplified,
1476 as much as possible, but is not to be considered "valid" in any sense
1477 implied by the target. Return true if any change is made. */
1478
1479 static bool
1480 instantiate_virtual_regs_in_rtx (rtx *loc)
1481 {
1482 if (!*loc)
1483 return false;
1484 bool changed = false;
1485 subrtx_ptr_iterator::array_type array;
1486 FOR_EACH_SUBRTX_PTR (iter, array, loc, NONCONST)
1487 {
1488 rtx *loc = *iter;
1489 if (rtx x = *loc)
1490 {
1491 rtx new_rtx;
1492 poly_int64 offset;
1493 switch (GET_CODE (x))
1494 {
1495 case REG:
1496 new_rtx = instantiate_new_reg (x, &offset);
1497 if (new_rtx)
1498 {
1499 *loc = plus_constant (GET_MODE (x), new_rtx, offset);
1500 changed = true;
1501 }
1502 iter.skip_subrtxes ();
1503 break;
1504
1505 case PLUS:
1506 new_rtx = instantiate_new_reg (XEXP (x, 0), &offset);
1507 if (new_rtx)
1508 {
1509 XEXP (x, 0) = new_rtx;
1510 *loc = plus_constant (GET_MODE (x), x, offset, true);
1511 changed = true;
1512 iter.skip_subrtxes ();
1513 break;
1514 }
1515
1516 /* FIXME -- from old code */
1517 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
1518 we can commute the PLUS and SUBREG because pointers into the
1519 frame are well-behaved. */
1520 break;
1521
1522 default:
1523 break;
1524 }
1525 }
1526 }
1527 return changed;
1528 }
1529
1530 /* A subroutine of instantiate_virtual_regs_in_insn. Return true if X
1531 matches the predicate for insn CODE operand OPERAND. */
1532
1533 static int
1534 safe_insn_predicate (int code, int operand, rtx x)
1535 {
1536 return code < 0 || insn_operand_matches ((enum insn_code) code, operand, x);
1537 }
1538
1539 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1540 registers present inside of insn. The result will be a valid insn. */
1541
1542 static void
1543 instantiate_virtual_regs_in_insn (rtx_insn *insn)
1544 {
1545 poly_int64 offset;
1546 int insn_code, i;
1547 bool any_change = false;
1548 rtx set, new_rtx, x;
1549 rtx_insn *seq;
1550
1551 /* There are some special cases to be handled first. */
1552 set = single_set (insn);
1553 if (set)
1554 {
1555 /* We're allowed to assign to a virtual register. This is interpreted
1556 to mean that the underlying register gets assigned the inverse
1557 transformation. This is used, for example, in the handling of
1558 non-local gotos. */
1559 new_rtx = instantiate_new_reg (SET_DEST (set), &offset);
1560 if (new_rtx)
1561 {
1562 start_sequence ();
1563
1564 instantiate_virtual_regs_in_rtx (&SET_SRC (set));
1565 x = simplify_gen_binary (PLUS, GET_MODE (new_rtx), SET_SRC (set),
1566 gen_int_mode (-offset, GET_MODE (new_rtx)));
1567 x = force_operand (x, new_rtx);
1568 if (x != new_rtx)
1569 emit_move_insn (new_rtx, x);
1570
1571 seq = get_insns ();
1572 end_sequence ();
1573
1574 emit_insn_before (seq, insn);
1575 delete_insn (insn);
1576 return;
1577 }
1578
1579 /* Handle a straight copy from a virtual register by generating a
1580 new add insn. The difference between this and falling through
1581 to the generic case is avoiding a new pseudo and eliminating a
1582 move insn in the initial rtl stream. */
1583 new_rtx = instantiate_new_reg (SET_SRC (set), &offset);
1584 if (new_rtx
1585 && maybe_ne (offset, 0)
1586 && REG_P (SET_DEST (set))
1587 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1588 {
1589 start_sequence ();
1590
1591 x = expand_simple_binop (GET_MODE (SET_DEST (set)), PLUS, new_rtx,
1592 gen_int_mode (offset,
1593 GET_MODE (SET_DEST (set))),
1594 SET_DEST (set), 1, OPTAB_LIB_WIDEN);
1595 if (x != SET_DEST (set))
1596 emit_move_insn (SET_DEST (set), x);
1597
1598 seq = get_insns ();
1599 end_sequence ();
1600
1601 emit_insn_before (seq, insn);
1602 delete_insn (insn);
1603 return;
1604 }
1605
1606 extract_insn (insn);
1607 insn_code = INSN_CODE (insn);
1608
1609 /* Handle a plus involving a virtual register by determining if the
1610 operands remain valid if they're modified in place. */
1611 poly_int64 delta;
1612 if (GET_CODE (SET_SRC (set)) == PLUS
1613 && recog_data.n_operands >= 3
1614 && recog_data.operand_loc[1] == &XEXP (SET_SRC (set), 0)
1615 && recog_data.operand_loc[2] == &XEXP (SET_SRC (set), 1)
1616 && poly_int_rtx_p (recog_data.operand[2], &delta)
1617 && (new_rtx = instantiate_new_reg (recog_data.operand[1], &offset)))
1618 {
1619 offset += delta;
1620
1621 /* If the sum is zero, then replace with a plain move. */
1622 if (known_eq (offset, 0)
1623 && REG_P (SET_DEST (set))
1624 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1625 {
1626 start_sequence ();
1627 emit_move_insn (SET_DEST (set), new_rtx);
1628 seq = get_insns ();
1629 end_sequence ();
1630
1631 emit_insn_before (seq, insn);
1632 delete_insn (insn);
1633 return;
1634 }
1635
1636 x = gen_int_mode (offset, recog_data.operand_mode[2]);
1637
1638 /* Using validate_change and apply_change_group here leaves
1639 recog_data in an invalid state. Since we know exactly what
1640 we want to check, do those two by hand. */
1641 if (safe_insn_predicate (insn_code, 1, new_rtx)
1642 && safe_insn_predicate (insn_code, 2, x))
1643 {
1644 *recog_data.operand_loc[1] = recog_data.operand[1] = new_rtx;
1645 *recog_data.operand_loc[2] = recog_data.operand[2] = x;
1646 any_change = true;
1647
1648 /* Fall through into the regular operand fixup loop in
1649 order to take care of operands other than 1 and 2. */
1650 }
1651 }
1652 }
1653 else
1654 {
1655 extract_insn (insn);
1656 insn_code = INSN_CODE (insn);
1657 }
1658
1659 /* In the general case, we expect virtual registers to appear only in
1660 operands, and then only as either bare registers or inside memories. */
1661 for (i = 0; i < recog_data.n_operands; ++i)
1662 {
1663 x = recog_data.operand[i];
1664 switch (GET_CODE (x))
1665 {
1666 case MEM:
1667 {
1668 rtx addr = XEXP (x, 0);
1669
1670 if (!instantiate_virtual_regs_in_rtx (&addr))
1671 continue;
1672
1673 start_sequence ();
1674 x = replace_equiv_address (x, addr, true);
1675 /* It may happen that the address with the virtual reg
1676 was valid (e.g. based on the virtual stack reg, which might
1677 be acceptable to the predicates with all offsets), whereas
1678 the address now isn't anymore, for instance when the address
1679 is still offsetted, but the base reg isn't virtual-stack-reg
1680 anymore. Below we would do a force_reg on the whole operand,
1681 but this insn might actually only accept memory. Hence,
1682 before doing that last resort, try to reload the address into
1683 a register, so this operand stays a MEM. */
1684 if (!safe_insn_predicate (insn_code, i, x))
1685 {
1686 addr = force_reg (GET_MODE (addr), addr);
1687 x = replace_equiv_address (x, addr, true);
1688 }
1689 seq = get_insns ();
1690 end_sequence ();
1691 if (seq)
1692 emit_insn_before (seq, insn);
1693 }
1694 break;
1695
1696 case REG:
1697 new_rtx = instantiate_new_reg (x, &offset);
1698 if (new_rtx == NULL)
1699 continue;
1700 if (known_eq (offset, 0))
1701 x = new_rtx;
1702 else
1703 {
1704 start_sequence ();
1705
1706 /* Careful, special mode predicates may have stuff in
1707 insn_data[insn_code].operand[i].mode that isn't useful
1708 to us for computing a new value. */
1709 /* ??? Recognize address_operand and/or "p" constraints
1710 to see if (plus new offset) is a valid before we put
1711 this through expand_simple_binop. */
1712 x = expand_simple_binop (GET_MODE (x), PLUS, new_rtx,
1713 gen_int_mode (offset, GET_MODE (x)),
1714 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1715 seq = get_insns ();
1716 end_sequence ();
1717 emit_insn_before (seq, insn);
1718 }
1719 break;
1720
1721 case SUBREG:
1722 new_rtx = instantiate_new_reg (SUBREG_REG (x), &offset);
1723 if (new_rtx == NULL)
1724 continue;
1725 if (maybe_ne (offset, 0))
1726 {
1727 start_sequence ();
1728 new_rtx = expand_simple_binop
1729 (GET_MODE (new_rtx), PLUS, new_rtx,
1730 gen_int_mode (offset, GET_MODE (new_rtx)),
1731 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1732 seq = get_insns ();
1733 end_sequence ();
1734 emit_insn_before (seq, insn);
1735 }
1736 x = simplify_gen_subreg (recog_data.operand_mode[i], new_rtx,
1737 GET_MODE (new_rtx), SUBREG_BYTE (x));
1738 gcc_assert (x);
1739 break;
1740
1741 default:
1742 continue;
1743 }
1744
1745 /* At this point, X contains the new value for the operand.
1746 Validate the new value vs the insn predicate. Note that
1747 asm insns will have insn_code -1 here. */
1748 if (!safe_insn_predicate (insn_code, i, x))
1749 {
1750 start_sequence ();
1751 if (REG_P (x))
1752 {
1753 gcc_assert (REGNO (x) <= LAST_VIRTUAL_REGISTER);
1754 x = copy_to_reg (x);
1755 }
1756 else
1757 x = force_reg (insn_data[insn_code].operand[i].mode, x);
1758 seq = get_insns ();
1759 end_sequence ();
1760 if (seq)
1761 emit_insn_before (seq, insn);
1762 }
1763
1764 *recog_data.operand_loc[i] = recog_data.operand[i] = x;
1765 any_change = true;
1766 }
1767
1768 if (any_change)
1769 {
1770 /* Propagate operand changes into the duplicates. */
1771 for (i = 0; i < recog_data.n_dups; ++i)
1772 *recog_data.dup_loc[i]
1773 = copy_rtx (recog_data.operand[(unsigned)recog_data.dup_num[i]]);
1774
1775 /* Force re-recognition of the instruction for validation. */
1776 INSN_CODE (insn) = -1;
1777 }
1778
1779 if (asm_noperands (PATTERN (insn)) >= 0)
1780 {
1781 if (!check_asm_operands (PATTERN (insn)))
1782 {
1783 error_for_asm (insn, "impossible constraint in %<asm%>");
1784 /* For asm goto, instead of fixing up all the edges
1785 just clear the template and clear input operands
1786 (asm goto doesn't have any output operands). */
1787 if (JUMP_P (insn))
1788 {
1789 rtx asm_op = extract_asm_operands (PATTERN (insn));
1790 ASM_OPERANDS_TEMPLATE (asm_op) = ggc_strdup ("");
1791 ASM_OPERANDS_INPUT_VEC (asm_op) = rtvec_alloc (0);
1792 ASM_OPERANDS_INPUT_CONSTRAINT_VEC (asm_op) = rtvec_alloc (0);
1793 }
1794 else
1795 delete_insn (insn);
1796 }
1797 }
1798 else
1799 {
1800 if (recog_memoized (insn) < 0)
1801 fatal_insn_not_found (insn);
1802 }
1803 }
1804
1805 /* Subroutine of instantiate_decls. Given RTL representing a decl,
1806 do any instantiation required. */
1807
1808 void
1809 instantiate_decl_rtl (rtx x)
1810 {
1811 rtx addr;
1812
1813 if (x == 0)
1814 return;
1815
1816 /* If this is a CONCAT, recurse for the pieces. */
1817 if (GET_CODE (x) == CONCAT)
1818 {
1819 instantiate_decl_rtl (XEXP (x, 0));
1820 instantiate_decl_rtl (XEXP (x, 1));
1821 return;
1822 }
1823
1824 /* If this is not a MEM, no need to do anything. Similarly if the
1825 address is a constant or a register that is not a virtual register. */
1826 if (!MEM_P (x))
1827 return;
1828
1829 addr = XEXP (x, 0);
1830 if (CONSTANT_P (addr)
1831 || (REG_P (addr)
1832 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
1833 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
1834 return;
1835
1836 instantiate_virtual_regs_in_rtx (&XEXP (x, 0));
1837 }
1838
1839 /* Helper for instantiate_decls called via walk_tree: Process all decls
1840 in the given DECL_VALUE_EXPR. */
1841
1842 static tree
1843 instantiate_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1844 {
1845 tree t = *tp;
1846 if (! EXPR_P (t))
1847 {
1848 *walk_subtrees = 0;
1849 if (DECL_P (t))
1850 {
1851 if (DECL_RTL_SET_P (t))
1852 instantiate_decl_rtl (DECL_RTL (t));
1853 if (TREE_CODE (t) == PARM_DECL && DECL_NAMELESS (t)
1854 && DECL_INCOMING_RTL (t))
1855 instantiate_decl_rtl (DECL_INCOMING_RTL (t));
1856 if ((VAR_P (t) || TREE_CODE (t) == RESULT_DECL)
1857 && DECL_HAS_VALUE_EXPR_P (t))
1858 {
1859 tree v = DECL_VALUE_EXPR (t);
1860 walk_tree (&v, instantiate_expr, NULL, NULL);
1861 }
1862 }
1863 }
1864 return NULL;
1865 }
1866
1867 /* Subroutine of instantiate_decls: Process all decls in the given
1868 BLOCK node and all its subblocks. */
1869
1870 static void
1871 instantiate_decls_1 (tree let)
1872 {
1873 tree t;
1874
1875 for (t = BLOCK_VARS (let); t; t = DECL_CHAIN (t))
1876 {
1877 if (DECL_RTL_SET_P (t))
1878 instantiate_decl_rtl (DECL_RTL (t));
1879 if (VAR_P (t) && DECL_HAS_VALUE_EXPR_P (t))
1880 {
1881 tree v = DECL_VALUE_EXPR (t);
1882 walk_tree (&v, instantiate_expr, NULL, NULL);
1883 }
1884 }
1885
1886 /* Process all subblocks. */
1887 for (t = BLOCK_SUBBLOCKS (let); t; t = BLOCK_CHAIN (t))
1888 instantiate_decls_1 (t);
1889 }
1890
1891 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1892 all virtual registers in their DECL_RTL's. */
1893
1894 static void
1895 instantiate_decls (tree fndecl)
1896 {
1897 tree decl;
1898 unsigned ix;
1899
1900 /* Process all parameters of the function. */
1901 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = DECL_CHAIN (decl))
1902 {
1903 instantiate_decl_rtl (DECL_RTL (decl));
1904 instantiate_decl_rtl (DECL_INCOMING_RTL (decl));
1905 if (DECL_HAS_VALUE_EXPR_P (decl))
1906 {
1907 tree v = DECL_VALUE_EXPR (decl);
1908 walk_tree (&v, instantiate_expr, NULL, NULL);
1909 }
1910 }
1911
1912 if ((decl = DECL_RESULT (fndecl))
1913 && TREE_CODE (decl) == RESULT_DECL)
1914 {
1915 if (DECL_RTL_SET_P (decl))
1916 instantiate_decl_rtl (DECL_RTL (decl));
1917 if (DECL_HAS_VALUE_EXPR_P (decl))
1918 {
1919 tree v = DECL_VALUE_EXPR (decl);
1920 walk_tree (&v, instantiate_expr, NULL, NULL);
1921 }
1922 }
1923
1924 /* Process the saved static chain if it exists. */
1925 decl = DECL_STRUCT_FUNCTION (fndecl)->static_chain_decl;
1926 if (decl && DECL_HAS_VALUE_EXPR_P (decl))
1927 instantiate_decl_rtl (DECL_RTL (DECL_VALUE_EXPR (decl)));
1928
1929 /* Now process all variables defined in the function or its subblocks. */
1930 if (DECL_INITIAL (fndecl))
1931 instantiate_decls_1 (DECL_INITIAL (fndecl));
1932
1933 FOR_EACH_LOCAL_DECL (cfun, ix, decl)
1934 if (DECL_RTL_SET_P (decl))
1935 instantiate_decl_rtl (DECL_RTL (decl));
1936 vec_free (cfun->local_decls);
1937 }
1938
1939 /* Pass through the INSNS of function FNDECL and convert virtual register
1940 references to hard register references. */
1941
1942 static unsigned int
1943 instantiate_virtual_regs (void)
1944 {
1945 rtx_insn *insn;
1946
1947 /* Compute the offsets to use for this function. */
1948 in_arg_offset = FIRST_PARM_OFFSET (current_function_decl);
1949 var_offset = targetm.starting_frame_offset ();
1950 dynamic_offset = STACK_DYNAMIC_OFFSET (current_function_decl);
1951 out_arg_offset = STACK_POINTER_OFFSET;
1952 #ifdef FRAME_POINTER_CFA_OFFSET
1953 cfa_offset = FRAME_POINTER_CFA_OFFSET (current_function_decl);
1954 #else
1955 cfa_offset = ARG_POINTER_CFA_OFFSET (current_function_decl);
1956 #endif
1957
1958 /* Initialize recognition, indicating that volatile is OK. */
1959 init_recog ();
1960
1961 /* Scan through all the insns, instantiating every virtual register still
1962 present. */
1963 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
1964 if (INSN_P (insn))
1965 {
1966 /* These patterns in the instruction stream can never be recognized.
1967 Fortunately, they shouldn't contain virtual registers either. */
1968 if (GET_CODE (PATTERN (insn)) == USE
1969 || GET_CODE (PATTERN (insn)) == CLOBBER
1970 || GET_CODE (PATTERN (insn)) == ASM_INPUT
1971 || DEBUG_MARKER_INSN_P (insn))
1972 continue;
1973 else if (DEBUG_BIND_INSN_P (insn))
1974 instantiate_virtual_regs_in_rtx (INSN_VAR_LOCATION_PTR (insn));
1975 else
1976 instantiate_virtual_regs_in_insn (insn);
1977
1978 if (insn->deleted ())
1979 continue;
1980
1981 instantiate_virtual_regs_in_rtx (&REG_NOTES (insn));
1982
1983 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
1984 if (CALL_P (insn))
1985 instantiate_virtual_regs_in_rtx (&CALL_INSN_FUNCTION_USAGE (insn));
1986 }
1987
1988 /* Instantiate the virtual registers in the DECLs for debugging purposes. */
1989 instantiate_decls (current_function_decl);
1990
1991 targetm.instantiate_decls ();
1992
1993 /* Indicate that, from now on, assign_stack_local should use
1994 frame_pointer_rtx. */
1995 virtuals_instantiated = 1;
1996
1997 return 0;
1998 }
1999
2000 namespace {
2001
2002 const pass_data pass_data_instantiate_virtual_regs =
2003 {
2004 RTL_PASS, /* type */
2005 "vregs", /* name */
2006 OPTGROUP_NONE, /* optinfo_flags */
2007 TV_NONE, /* tv_id */
2008 0, /* properties_required */
2009 0, /* properties_provided */
2010 0, /* properties_destroyed */
2011 0, /* todo_flags_start */
2012 0, /* todo_flags_finish */
2013 };
2014
2015 class pass_instantiate_virtual_regs : public rtl_opt_pass
2016 {
2017 public:
2018 pass_instantiate_virtual_regs (gcc::context *ctxt)
2019 : rtl_opt_pass (pass_data_instantiate_virtual_regs, ctxt)
2020 {}
2021
2022 /* opt_pass methods: */
2023 virtual unsigned int execute (function *)
2024 {
2025 return instantiate_virtual_regs ();
2026 }
2027
2028 }; // class pass_instantiate_virtual_regs
2029
2030 } // anon namespace
2031
2032 rtl_opt_pass *
2033 make_pass_instantiate_virtual_regs (gcc::context *ctxt)
2034 {
2035 return new pass_instantiate_virtual_regs (ctxt);
2036 }
2037
2038 \f
2039 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
2040 This means a type for which function calls must pass an address to the
2041 function or get an address back from the function.
2042 EXP may be a type node or an expression (whose type is tested). */
2043
2044 int
2045 aggregate_value_p (const_tree exp, const_tree fntype)
2046 {
2047 const_tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
2048 int i, regno, nregs;
2049 rtx reg;
2050
2051 if (fntype)
2052 switch (TREE_CODE (fntype))
2053 {
2054 case CALL_EXPR:
2055 {
2056 tree fndecl = get_callee_fndecl (fntype);
2057 if (fndecl)
2058 fntype = TREE_TYPE (fndecl);
2059 else if (CALL_EXPR_FN (fntype))
2060 fntype = TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (fntype)));
2061 else
2062 /* For internal functions, assume nothing needs to be
2063 returned in memory. */
2064 return 0;
2065 }
2066 break;
2067 case FUNCTION_DECL:
2068 fntype = TREE_TYPE (fntype);
2069 break;
2070 case FUNCTION_TYPE:
2071 case METHOD_TYPE:
2072 break;
2073 case IDENTIFIER_NODE:
2074 fntype = NULL_TREE;
2075 break;
2076 default:
2077 /* We don't expect other tree types here. */
2078 gcc_unreachable ();
2079 }
2080
2081 if (VOID_TYPE_P (type))
2082 return 0;
2083
2084 /* If a record should be passed the same as its first (and only) member
2085 don't pass it as an aggregate. */
2086 if (TREE_CODE (type) == RECORD_TYPE && TYPE_TRANSPARENT_AGGR (type))
2087 return aggregate_value_p (first_field (type), fntype);
2088
2089 /* If the front end has decided that this needs to be passed by
2090 reference, do so. */
2091 if ((TREE_CODE (exp) == PARM_DECL || TREE_CODE (exp) == RESULT_DECL)
2092 && DECL_BY_REFERENCE (exp))
2093 return 1;
2094
2095 /* Function types that are TREE_ADDRESSABLE force return in memory. */
2096 if (fntype && TREE_ADDRESSABLE (fntype))
2097 return 1;
2098
2099 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
2100 and thus can't be returned in registers. */
2101 if (TREE_ADDRESSABLE (type))
2102 return 1;
2103
2104 if (TYPE_EMPTY_P (type))
2105 return 0;
2106
2107 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
2108 return 1;
2109
2110 if (targetm.calls.return_in_memory (type, fntype))
2111 return 1;
2112
2113 /* Make sure we have suitable call-clobbered regs to return
2114 the value in; if not, we must return it in memory. */
2115 reg = hard_function_value (type, 0, fntype, 0);
2116
2117 /* If we have something other than a REG (e.g. a PARALLEL), then assume
2118 it is OK. */
2119 if (!REG_P (reg))
2120 return 0;
2121
2122 regno = REGNO (reg);
2123 nregs = hard_regno_nregs (regno, TYPE_MODE (type));
2124 for (i = 0; i < nregs; i++)
2125 if (! call_used_regs[regno + i])
2126 return 1;
2127
2128 return 0;
2129 }
2130 \f
2131 /* Return true if we should assign DECL a pseudo register; false if it
2132 should live on the local stack. */
2133
2134 bool
2135 use_register_for_decl (const_tree decl)
2136 {
2137 if (TREE_CODE (decl) == SSA_NAME)
2138 {
2139 /* We often try to use the SSA_NAME, instead of its underlying
2140 decl, to get type information and guide decisions, to avoid
2141 differences of behavior between anonymous and named
2142 variables, but in this one case we have to go for the actual
2143 variable if there is one. The main reason is that, at least
2144 at -O0, we want to place user variables on the stack, but we
2145 don't mind using pseudos for anonymous or ignored temps.
2146 Should we take the SSA_NAME, we'd conclude all SSA_NAMEs
2147 should go in pseudos, whereas their corresponding variables
2148 might have to go on the stack. So, disregarding the decl
2149 here would negatively impact debug info at -O0, enable
2150 coalescing between SSA_NAMEs that ought to get different
2151 stack/pseudo assignments, and get the incoming argument
2152 processing thoroughly confused by PARM_DECLs expected to live
2153 in stack slots but assigned to pseudos. */
2154 if (!SSA_NAME_VAR (decl))
2155 return TYPE_MODE (TREE_TYPE (decl)) != BLKmode
2156 && !(flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)));
2157
2158 decl = SSA_NAME_VAR (decl);
2159 }
2160
2161 /* Honor volatile. */
2162 if (TREE_SIDE_EFFECTS (decl))
2163 return false;
2164
2165 /* Honor addressability. */
2166 if (TREE_ADDRESSABLE (decl))
2167 return false;
2168
2169 /* RESULT_DECLs are a bit special in that they're assigned without
2170 regard to use_register_for_decl, but we generally only store in
2171 them. If we coalesce their SSA NAMEs, we'd better return a
2172 result that matches the assignment in expand_function_start. */
2173 if (TREE_CODE (decl) == RESULT_DECL)
2174 {
2175 /* If it's not an aggregate, we're going to use a REG or a
2176 PARALLEL containing a REG. */
2177 if (!aggregate_value_p (decl, current_function_decl))
2178 return true;
2179
2180 /* If expand_function_start determines the return value, we'll
2181 use MEM if it's not by reference. */
2182 if (cfun->returns_pcc_struct
2183 || (targetm.calls.struct_value_rtx
2184 (TREE_TYPE (current_function_decl), 1)))
2185 return DECL_BY_REFERENCE (decl);
2186
2187 /* Otherwise, we're taking an extra all.function_result_decl
2188 argument. It's set up in assign_parms_augmented_arg_list,
2189 under the (negated) conditions above, and then it's used to
2190 set up the RESULT_DECL rtl in assign_params, after looping
2191 over all parameters. Now, if the RESULT_DECL is not by
2192 reference, we'll use a MEM either way. */
2193 if (!DECL_BY_REFERENCE (decl))
2194 return false;
2195
2196 /* Otherwise, if RESULT_DECL is DECL_BY_REFERENCE, it will take
2197 the function_result_decl's assignment. Since it's a pointer,
2198 we can short-circuit a number of the tests below, and we must
2199 duplicat e them because we don't have the
2200 function_result_decl to test. */
2201 if (!targetm.calls.allocate_stack_slots_for_args ())
2202 return true;
2203 /* We don't set DECL_IGNORED_P for the function_result_decl. */
2204 if (optimize)
2205 return true;
2206 /* We don't set DECL_REGISTER for the function_result_decl. */
2207 return false;
2208 }
2209
2210 /* Only register-like things go in registers. */
2211 if (DECL_MODE (decl) == BLKmode)
2212 return false;
2213
2214 /* If -ffloat-store specified, don't put explicit float variables
2215 into registers. */
2216 /* ??? This should be checked after DECL_ARTIFICIAL, but tree-ssa
2217 propagates values across these stores, and it probably shouldn't. */
2218 if (flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)))
2219 return false;
2220
2221 if (!targetm.calls.allocate_stack_slots_for_args ())
2222 return true;
2223
2224 /* If we're not interested in tracking debugging information for
2225 this decl, then we can certainly put it in a register. */
2226 if (DECL_IGNORED_P (decl))
2227 return true;
2228
2229 if (optimize)
2230 return true;
2231
2232 if (!DECL_REGISTER (decl))
2233 return false;
2234
2235 /* When not optimizing, disregard register keyword for types that
2236 could have methods, otherwise the methods won't be callable from
2237 the debugger. */
2238 if (RECORD_OR_UNION_TYPE_P (TREE_TYPE (decl)))
2239 return false;
2240
2241 return true;
2242 }
2243
2244 /* Structures to communicate between the subroutines of assign_parms.
2245 The first holds data persistent across all parameters, the second
2246 is cleared out for each parameter. */
2247
2248 struct assign_parm_data_all
2249 {
2250 /* When INIT_CUMULATIVE_ARGS gets revamped, allocating CUMULATIVE_ARGS
2251 should become a job of the target or otherwise encapsulated. */
2252 CUMULATIVE_ARGS args_so_far_v;
2253 cumulative_args_t args_so_far;
2254 struct args_size stack_args_size;
2255 tree function_result_decl;
2256 tree orig_fnargs;
2257 rtx_insn *first_conversion_insn;
2258 rtx_insn *last_conversion_insn;
2259 HOST_WIDE_INT pretend_args_size;
2260 HOST_WIDE_INT extra_pretend_bytes;
2261 int reg_parm_stack_space;
2262 };
2263
2264 struct assign_parm_data_one
2265 {
2266 tree nominal_type;
2267 function_arg_info arg;
2268 rtx entry_parm;
2269 rtx stack_parm;
2270 machine_mode nominal_mode;
2271 machine_mode passed_mode;
2272 struct locate_and_pad_arg_data locate;
2273 int partial;
2274 BOOL_BITFIELD passed_pointer : 1;
2275 };
2276
2277 /* A subroutine of assign_parms. Initialize ALL. */
2278
2279 static void
2280 assign_parms_initialize_all (struct assign_parm_data_all *all)
2281 {
2282 tree fntype ATTRIBUTE_UNUSED;
2283
2284 memset (all, 0, sizeof (*all));
2285
2286 fntype = TREE_TYPE (current_function_decl);
2287
2288 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
2289 INIT_CUMULATIVE_INCOMING_ARGS (all->args_so_far_v, fntype, NULL_RTX);
2290 #else
2291 INIT_CUMULATIVE_ARGS (all->args_so_far_v, fntype, NULL_RTX,
2292 current_function_decl, -1);
2293 #endif
2294 all->args_so_far = pack_cumulative_args (&all->args_so_far_v);
2295
2296 #ifdef INCOMING_REG_PARM_STACK_SPACE
2297 all->reg_parm_stack_space
2298 = INCOMING_REG_PARM_STACK_SPACE (current_function_decl);
2299 #endif
2300 }
2301
2302 /* If ARGS contains entries with complex types, split the entry into two
2303 entries of the component type. Return a new list of substitutions are
2304 needed, else the old list. */
2305
2306 static void
2307 split_complex_args (vec<tree> *args)
2308 {
2309 unsigned i;
2310 tree p;
2311
2312 FOR_EACH_VEC_ELT (*args, i, p)
2313 {
2314 tree type = TREE_TYPE (p);
2315 if (TREE_CODE (type) == COMPLEX_TYPE
2316 && targetm.calls.split_complex_arg (type))
2317 {
2318 tree decl;
2319 tree subtype = TREE_TYPE (type);
2320 bool addressable = TREE_ADDRESSABLE (p);
2321
2322 /* Rewrite the PARM_DECL's type with its component. */
2323 p = copy_node (p);
2324 TREE_TYPE (p) = subtype;
2325 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
2326 SET_DECL_MODE (p, VOIDmode);
2327 DECL_SIZE (p) = NULL;
2328 DECL_SIZE_UNIT (p) = NULL;
2329 /* If this arg must go in memory, put it in a pseudo here.
2330 We can't allow it to go in memory as per normal parms,
2331 because the usual place might not have the imag part
2332 adjacent to the real part. */
2333 DECL_ARTIFICIAL (p) = addressable;
2334 DECL_IGNORED_P (p) = addressable;
2335 TREE_ADDRESSABLE (p) = 0;
2336 layout_decl (p, 0);
2337 (*args)[i] = p;
2338
2339 /* Build a second synthetic decl. */
2340 decl = build_decl (EXPR_LOCATION (p),
2341 PARM_DECL, NULL_TREE, subtype);
2342 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
2343 DECL_ARTIFICIAL (decl) = addressable;
2344 DECL_IGNORED_P (decl) = addressable;
2345 layout_decl (decl, 0);
2346 args->safe_insert (++i, decl);
2347 }
2348 }
2349 }
2350
2351 /* A subroutine of assign_parms. Adjust the parameter list to incorporate
2352 the hidden struct return argument, and (abi willing) complex args.
2353 Return the new parameter list. */
2354
2355 static vec<tree>
2356 assign_parms_augmented_arg_list (struct assign_parm_data_all *all)
2357 {
2358 tree fndecl = current_function_decl;
2359 tree fntype = TREE_TYPE (fndecl);
2360 vec<tree> fnargs = vNULL;
2361 tree arg;
2362
2363 for (arg = DECL_ARGUMENTS (fndecl); arg; arg = DECL_CHAIN (arg))
2364 fnargs.safe_push (arg);
2365
2366 all->orig_fnargs = DECL_ARGUMENTS (fndecl);
2367
2368 /* If struct value address is treated as the first argument, make it so. */
2369 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
2370 && ! cfun->returns_pcc_struct
2371 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
2372 {
2373 tree type = build_pointer_type (TREE_TYPE (fntype));
2374 tree decl;
2375
2376 decl = build_decl (DECL_SOURCE_LOCATION (fndecl),
2377 PARM_DECL, get_identifier (".result_ptr"), type);
2378 DECL_ARG_TYPE (decl) = type;
2379 DECL_ARTIFICIAL (decl) = 1;
2380 DECL_NAMELESS (decl) = 1;
2381 TREE_CONSTANT (decl) = 1;
2382 /* We don't set DECL_IGNORED_P or DECL_REGISTER here. If this
2383 changes, the end of the RESULT_DECL handling block in
2384 use_register_for_decl must be adjusted to match. */
2385
2386 DECL_CHAIN (decl) = all->orig_fnargs;
2387 all->orig_fnargs = decl;
2388 fnargs.safe_insert (0, decl);
2389
2390 all->function_result_decl = decl;
2391 }
2392
2393 /* If the target wants to split complex arguments into scalars, do so. */
2394 if (targetm.calls.split_complex_arg)
2395 split_complex_args (&fnargs);
2396
2397 return fnargs;
2398 }
2399
2400 /* A subroutine of assign_parms. Examine PARM and pull out type and mode
2401 data for the parameter. Incorporate ABI specifics such as pass-by-
2402 reference and type promotion. */
2403
2404 static void
2405 assign_parm_find_data_types (struct assign_parm_data_all *all, tree parm,
2406 struct assign_parm_data_one *data)
2407 {
2408 int unsignedp;
2409
2410 *data = assign_parm_data_one ();
2411
2412 /* NAMED_ARG is a misnomer. We really mean 'non-variadic'. */
2413 if (!cfun->stdarg)
2414 data->arg.named = 1; /* No variadic parms. */
2415 else if (DECL_CHAIN (parm))
2416 data->arg.named = 1; /* Not the last non-variadic parm. */
2417 else if (targetm.calls.strict_argument_naming (all->args_so_far))
2418 data->arg.named = 1; /* Only variadic ones are unnamed. */
2419 else
2420 data->arg.named = 0; /* Treat as variadic. */
2421
2422 data->nominal_type = TREE_TYPE (parm);
2423 data->arg.type = DECL_ARG_TYPE (parm);
2424
2425 /* Look out for errors propagating this far. Also, if the parameter's
2426 type is void then its value doesn't matter. */
2427 if (TREE_TYPE (parm) == error_mark_node
2428 /* This can happen after weird syntax errors
2429 or if an enum type is defined among the parms. */
2430 || TREE_CODE (parm) != PARM_DECL
2431 || data->arg.type == NULL
2432 || VOID_TYPE_P (data->nominal_type))
2433 {
2434 data->nominal_type = data->arg.type = void_type_node;
2435 data->nominal_mode = data->passed_mode = data->arg.mode = VOIDmode;
2436 return;
2437 }
2438
2439 /* Find mode of arg as it is passed, and mode of arg as it should be
2440 during execution of this function. */
2441 data->passed_mode = data->arg.mode = TYPE_MODE (data->arg.type);
2442 data->nominal_mode = TYPE_MODE (data->nominal_type);
2443
2444 /* If the parm is to be passed as a transparent union or record, use the
2445 type of the first field for the tests below. We have already verified
2446 that the modes are the same. */
2447 if ((TREE_CODE (data->arg.type) == UNION_TYPE
2448 || TREE_CODE (data->arg.type) == RECORD_TYPE)
2449 && TYPE_TRANSPARENT_AGGR (data->arg.type))
2450 data->arg.type = TREE_TYPE (first_field (data->arg.type));
2451
2452 /* See if this arg was passed by invisible reference. */
2453 if (apply_pass_by_reference_rules (&all->args_so_far_v, data->arg))
2454 {
2455 data->nominal_type = data->arg.type;
2456 data->passed_pointer = true;
2457 data->passed_mode = data->nominal_mode = data->arg.mode;
2458 }
2459
2460 /* Find mode as it is passed by the ABI. */
2461 unsignedp = TYPE_UNSIGNED (data->arg.type);
2462 data->arg.mode
2463 = promote_function_mode (data->arg.type, data->arg.mode, &unsignedp,
2464 TREE_TYPE (current_function_decl), 0);
2465 }
2466
2467 /* A subroutine of assign_parms. Invoke setup_incoming_varargs. */
2468
2469 static void
2470 assign_parms_setup_varargs (struct assign_parm_data_all *all,
2471 struct assign_parm_data_one *data, bool no_rtl)
2472 {
2473 int varargs_pretend_bytes = 0;
2474
2475 function_arg_info last_named_arg = data->arg;
2476 last_named_arg.named = true;
2477 targetm.calls.setup_incoming_varargs (all->args_so_far, last_named_arg,
2478 &varargs_pretend_bytes, no_rtl);
2479
2480 /* If the back-end has requested extra stack space, record how much is
2481 needed. Do not change pretend_args_size otherwise since it may be
2482 nonzero from an earlier partial argument. */
2483 if (varargs_pretend_bytes > 0)
2484 all->pretend_args_size = varargs_pretend_bytes;
2485 }
2486
2487 /* A subroutine of assign_parms. Set DATA->ENTRY_PARM corresponding to
2488 the incoming location of the current parameter. */
2489
2490 static void
2491 assign_parm_find_entry_rtl (struct assign_parm_data_all *all,
2492 struct assign_parm_data_one *data)
2493 {
2494 HOST_WIDE_INT pretend_bytes = 0;
2495 rtx entry_parm;
2496 bool in_regs;
2497
2498 if (data->arg.mode == VOIDmode)
2499 {
2500 data->entry_parm = data->stack_parm = const0_rtx;
2501 return;
2502 }
2503
2504 targetm.calls.warn_parameter_passing_abi (all->args_so_far,
2505 data->arg.type);
2506
2507 entry_parm = targetm.calls.function_incoming_arg (all->args_so_far,
2508 data->arg);
2509 if (entry_parm == 0)
2510 data->arg.mode = data->passed_mode;
2511
2512 /* Determine parm's home in the stack, in case it arrives in the stack
2513 or we should pretend it did. Compute the stack position and rtx where
2514 the argument arrives and its size.
2515
2516 There is one complexity here: If this was a parameter that would
2517 have been passed in registers, but wasn't only because it is
2518 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2519 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2520 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of 0
2521 as it was the previous time. */
2522 in_regs = (entry_parm != 0);
2523 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2524 in_regs = true;
2525 #endif
2526 if (!in_regs && !data->arg.named)
2527 {
2528 if (targetm.calls.pretend_outgoing_varargs_named (all->args_so_far))
2529 {
2530 rtx tem;
2531 function_arg_info named_arg = data->arg;
2532 named_arg.named = true;
2533 tem = targetm.calls.function_incoming_arg (all->args_so_far,
2534 named_arg);
2535 in_regs = tem != NULL;
2536 }
2537 }
2538
2539 /* If this parameter was passed both in registers and in the stack, use
2540 the copy on the stack. */
2541 if (targetm.calls.must_pass_in_stack (data->arg))
2542 entry_parm = 0;
2543
2544 if (entry_parm)
2545 {
2546 int partial;
2547
2548 partial = targetm.calls.arg_partial_bytes (all->args_so_far, data->arg);
2549 data->partial = partial;
2550
2551 /* The caller might already have allocated stack space for the
2552 register parameters. */
2553 if (partial != 0 && all->reg_parm_stack_space == 0)
2554 {
2555 /* Part of this argument is passed in registers and part
2556 is passed on the stack. Ask the prologue code to extend
2557 the stack part so that we can recreate the full value.
2558
2559 PRETEND_BYTES is the size of the registers we need to store.
2560 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
2561 stack space that the prologue should allocate.
2562
2563 Internally, gcc assumes that the argument pointer is aligned
2564 to STACK_BOUNDARY bits. This is used both for alignment
2565 optimizations (see init_emit) and to locate arguments that are
2566 aligned to more than PARM_BOUNDARY bits. We must preserve this
2567 invariant by rounding CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to
2568 a stack boundary. */
2569
2570 /* We assume at most one partial arg, and it must be the first
2571 argument on the stack. */
2572 gcc_assert (!all->extra_pretend_bytes && !all->pretend_args_size);
2573
2574 pretend_bytes = partial;
2575 all->pretend_args_size = CEIL_ROUND (pretend_bytes, STACK_BYTES);
2576
2577 /* We want to align relative to the actual stack pointer, so
2578 don't include this in the stack size until later. */
2579 all->extra_pretend_bytes = all->pretend_args_size;
2580 }
2581 }
2582
2583 locate_and_pad_parm (data->arg.mode, data->arg.type, in_regs,
2584 all->reg_parm_stack_space,
2585 entry_parm ? data->partial : 0, current_function_decl,
2586 &all->stack_args_size, &data->locate);
2587
2588 /* Update parm_stack_boundary if this parameter is passed in the
2589 stack. */
2590 if (!in_regs && crtl->parm_stack_boundary < data->locate.boundary)
2591 crtl->parm_stack_boundary = data->locate.boundary;
2592
2593 /* Adjust offsets to include the pretend args. */
2594 pretend_bytes = all->extra_pretend_bytes - pretend_bytes;
2595 data->locate.slot_offset.constant += pretend_bytes;
2596 data->locate.offset.constant += pretend_bytes;
2597
2598 data->entry_parm = entry_parm;
2599 }
2600
2601 /* A subroutine of assign_parms. If there is actually space on the stack
2602 for this parm, count it in stack_args_size and return true. */
2603
2604 static bool
2605 assign_parm_is_stack_parm (struct assign_parm_data_all *all,
2606 struct assign_parm_data_one *data)
2607 {
2608 /* Trivially true if we've no incoming register. */
2609 if (data->entry_parm == NULL)
2610 ;
2611 /* Also true if we're partially in registers and partially not,
2612 since we've arranged to drop the entire argument on the stack. */
2613 else if (data->partial != 0)
2614 ;
2615 /* Also true if the target says that it's passed in both registers
2616 and on the stack. */
2617 else if (GET_CODE (data->entry_parm) == PARALLEL
2618 && XEXP (XVECEXP (data->entry_parm, 0, 0), 0) == NULL_RTX)
2619 ;
2620 /* Also true if the target says that there's stack allocated for
2621 all register parameters. */
2622 else if (all->reg_parm_stack_space > 0)
2623 ;
2624 /* Otherwise, no, this parameter has no ABI defined stack slot. */
2625 else
2626 return false;
2627
2628 all->stack_args_size.constant += data->locate.size.constant;
2629 if (data->locate.size.var)
2630 ADD_PARM_SIZE (all->stack_args_size, data->locate.size.var);
2631
2632 return true;
2633 }
2634
2635 /* A subroutine of assign_parms. Given that this parameter is allocated
2636 stack space by the ABI, find it. */
2637
2638 static void
2639 assign_parm_find_stack_rtl (tree parm, struct assign_parm_data_one *data)
2640 {
2641 rtx offset_rtx, stack_parm;
2642 unsigned int align, boundary;
2643
2644 /* If we're passing this arg using a reg, make its stack home the
2645 aligned stack slot. */
2646 if (data->entry_parm)
2647 offset_rtx = ARGS_SIZE_RTX (data->locate.slot_offset);
2648 else
2649 offset_rtx = ARGS_SIZE_RTX (data->locate.offset);
2650
2651 stack_parm = crtl->args.internal_arg_pointer;
2652 if (offset_rtx != const0_rtx)
2653 stack_parm = gen_rtx_PLUS (Pmode, stack_parm, offset_rtx);
2654 stack_parm = gen_rtx_MEM (data->arg.mode, stack_parm);
2655
2656 if (!data->passed_pointer)
2657 {
2658 set_mem_attributes (stack_parm, parm, 1);
2659 /* set_mem_attributes could set MEM_SIZE to the passed mode's size,
2660 while promoted mode's size is needed. */
2661 if (data->arg.mode != BLKmode
2662 && data->arg.mode != DECL_MODE (parm))
2663 {
2664 set_mem_size (stack_parm, GET_MODE_SIZE (data->arg.mode));
2665 if (MEM_EXPR (stack_parm) && MEM_OFFSET_KNOWN_P (stack_parm))
2666 {
2667 poly_int64 offset = subreg_lowpart_offset (DECL_MODE (parm),
2668 data->arg.mode);
2669 if (maybe_ne (offset, 0))
2670 set_mem_offset (stack_parm, MEM_OFFSET (stack_parm) - offset);
2671 }
2672 }
2673 }
2674
2675 boundary = data->locate.boundary;
2676 align = BITS_PER_UNIT;
2677
2678 /* If we're padding upward, we know that the alignment of the slot
2679 is TARGET_FUNCTION_ARG_BOUNDARY. If we're using slot_offset, we're
2680 intentionally forcing upward padding. Otherwise we have to come
2681 up with a guess at the alignment based on OFFSET_RTX. */
2682 poly_int64 offset;
2683 if (data->locate.where_pad == PAD_NONE || data->entry_parm)
2684 align = boundary;
2685 else if (data->locate.where_pad == PAD_UPWARD)
2686 {
2687 align = boundary;
2688 /* If the argument offset is actually more aligned than the nominal
2689 stack slot boundary, take advantage of that excess alignment.
2690 Don't make any assumptions if STACK_POINTER_OFFSET is in use. */
2691 if (poly_int_rtx_p (offset_rtx, &offset)
2692 && STACK_POINTER_OFFSET == 0)
2693 {
2694 unsigned int offset_align = known_alignment (offset) * BITS_PER_UNIT;
2695 if (offset_align == 0 || offset_align > STACK_BOUNDARY)
2696 offset_align = STACK_BOUNDARY;
2697 align = MAX (align, offset_align);
2698 }
2699 }
2700 else if (poly_int_rtx_p (offset_rtx, &offset))
2701 {
2702 align = least_bit_hwi (boundary);
2703 unsigned int offset_align = known_alignment (offset) * BITS_PER_UNIT;
2704 if (offset_align != 0)
2705 align = MIN (align, offset_align);
2706 }
2707 set_mem_align (stack_parm, align);
2708
2709 if (data->entry_parm)
2710 set_reg_attrs_for_parm (data->entry_parm, stack_parm);
2711
2712 data->stack_parm = stack_parm;
2713 }
2714
2715 /* A subroutine of assign_parms. Adjust DATA->ENTRY_RTL such that it's
2716 always valid and contiguous. */
2717
2718 static void
2719 assign_parm_adjust_entry_rtl (struct assign_parm_data_one *data)
2720 {
2721 rtx entry_parm = data->entry_parm;
2722 rtx stack_parm = data->stack_parm;
2723
2724 /* If this parm was passed part in regs and part in memory, pretend it
2725 arrived entirely in memory by pushing the register-part onto the stack.
2726 In the special case of a DImode or DFmode that is split, we could put
2727 it together in a pseudoreg directly, but for now that's not worth
2728 bothering with. */
2729 if (data->partial != 0)
2730 {
2731 /* Handle calls that pass values in multiple non-contiguous
2732 locations. The Irix 6 ABI has examples of this. */
2733 if (GET_CODE (entry_parm) == PARALLEL)
2734 emit_group_store (validize_mem (copy_rtx (stack_parm)), entry_parm,
2735 data->arg.type, int_size_in_bytes (data->arg.type));
2736 else
2737 {
2738 gcc_assert (data->partial % UNITS_PER_WORD == 0);
2739 move_block_from_reg (REGNO (entry_parm),
2740 validize_mem (copy_rtx (stack_parm)),
2741 data->partial / UNITS_PER_WORD);
2742 }
2743
2744 entry_parm = stack_parm;
2745 }
2746
2747 /* If we didn't decide this parm came in a register, by default it came
2748 on the stack. */
2749 else if (entry_parm == NULL)
2750 entry_parm = stack_parm;
2751
2752 /* When an argument is passed in multiple locations, we can't make use
2753 of this information, but we can save some copying if the whole argument
2754 is passed in a single register. */
2755 else if (GET_CODE (entry_parm) == PARALLEL
2756 && data->nominal_mode != BLKmode
2757 && data->passed_mode != BLKmode)
2758 {
2759 size_t i, len = XVECLEN (entry_parm, 0);
2760
2761 for (i = 0; i < len; i++)
2762 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
2763 && REG_P (XEXP (XVECEXP (entry_parm, 0, i), 0))
2764 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
2765 == data->passed_mode)
2766 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
2767 {
2768 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
2769 break;
2770 }
2771 }
2772
2773 data->entry_parm = entry_parm;
2774 }
2775
2776 /* A subroutine of assign_parms. Reconstitute any values which were
2777 passed in multiple registers and would fit in a single register. */
2778
2779 static void
2780 assign_parm_remove_parallels (struct assign_parm_data_one *data)
2781 {
2782 rtx entry_parm = data->entry_parm;
2783
2784 /* Convert the PARALLEL to a REG of the same mode as the parallel.
2785 This can be done with register operations rather than on the
2786 stack, even if we will store the reconstituted parameter on the
2787 stack later. */
2788 if (GET_CODE (entry_parm) == PARALLEL && GET_MODE (entry_parm) != BLKmode)
2789 {
2790 rtx parmreg = gen_reg_rtx (GET_MODE (entry_parm));
2791 emit_group_store (parmreg, entry_parm, data->arg.type,
2792 GET_MODE_SIZE (GET_MODE (entry_parm)));
2793 entry_parm = parmreg;
2794 }
2795
2796 data->entry_parm = entry_parm;
2797 }
2798
2799 /* A subroutine of assign_parms. Adjust DATA->STACK_RTL such that it's
2800 always valid and properly aligned. */
2801
2802 static void
2803 assign_parm_adjust_stack_rtl (struct assign_parm_data_one *data)
2804 {
2805 rtx stack_parm = data->stack_parm;
2806
2807 /* If we can't trust the parm stack slot to be aligned enough for its
2808 ultimate type, don't use that slot after entry. We'll make another
2809 stack slot, if we need one. */
2810 if (stack_parm
2811 && ((GET_MODE_ALIGNMENT (data->nominal_mode) > MEM_ALIGN (stack_parm)
2812 && targetm.slow_unaligned_access (data->nominal_mode,
2813 MEM_ALIGN (stack_parm)))
2814 || (data->nominal_type
2815 && TYPE_ALIGN (data->nominal_type) > MEM_ALIGN (stack_parm)
2816 && MEM_ALIGN (stack_parm) < PREFERRED_STACK_BOUNDARY)))
2817 stack_parm = NULL;
2818
2819 /* If parm was passed in memory, and we need to convert it on entry,
2820 don't store it back in that same slot. */
2821 else if (data->entry_parm == stack_parm
2822 && data->nominal_mode != BLKmode
2823 && data->nominal_mode != data->passed_mode)
2824 stack_parm = NULL;
2825
2826 /* If stack protection is in effect for this function, don't leave any
2827 pointers in their passed stack slots. */
2828 else if (crtl->stack_protect_guard
2829 && (flag_stack_protect == 2
2830 || data->passed_pointer
2831 || POINTER_TYPE_P (data->nominal_type)))
2832 stack_parm = NULL;
2833
2834 data->stack_parm = stack_parm;
2835 }
2836
2837 /* A subroutine of assign_parms. Return true if the current parameter
2838 should be stored as a BLKmode in the current frame. */
2839
2840 static bool
2841 assign_parm_setup_block_p (struct assign_parm_data_one *data)
2842 {
2843 if (data->nominal_mode == BLKmode)
2844 return true;
2845 if (GET_MODE (data->entry_parm) == BLKmode)
2846 return true;
2847
2848 #ifdef BLOCK_REG_PADDING
2849 /* Only assign_parm_setup_block knows how to deal with register arguments
2850 that are padded at the least significant end. */
2851 if (REG_P (data->entry_parm)
2852 && known_lt (GET_MODE_SIZE (data->arg.mode), UNITS_PER_WORD)
2853 && (BLOCK_REG_PADDING (data->passed_mode, data->arg.type, 1)
2854 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
2855 return true;
2856 #endif
2857
2858 return false;
2859 }
2860
2861 /* A subroutine of assign_parms. Arrange for the parameter to be
2862 present and valid in DATA->STACK_RTL. */
2863
2864 static void
2865 assign_parm_setup_block (struct assign_parm_data_all *all,
2866 tree parm, struct assign_parm_data_one *data)
2867 {
2868 rtx entry_parm = data->entry_parm;
2869 rtx stack_parm = data->stack_parm;
2870 rtx target_reg = NULL_RTX;
2871 bool in_conversion_seq = false;
2872 HOST_WIDE_INT size;
2873 HOST_WIDE_INT size_stored;
2874
2875 if (GET_CODE (entry_parm) == PARALLEL)
2876 entry_parm = emit_group_move_into_temps (entry_parm);
2877
2878 /* If we want the parameter in a pseudo, don't use a stack slot. */
2879 if (is_gimple_reg (parm) && use_register_for_decl (parm))
2880 {
2881 tree def = ssa_default_def (cfun, parm);
2882 gcc_assert (def);
2883 machine_mode mode = promote_ssa_mode (def, NULL);
2884 rtx reg = gen_reg_rtx (mode);
2885 if (GET_CODE (reg) != CONCAT)
2886 stack_parm = reg;
2887 else
2888 {
2889 target_reg = reg;
2890 /* Avoid allocating a stack slot, if there isn't one
2891 preallocated by the ABI. It might seem like we should
2892 always prefer a pseudo, but converting between
2893 floating-point and integer modes goes through the stack
2894 on various machines, so it's better to use the reserved
2895 stack slot than to risk wasting it and allocating more
2896 for the conversion. */
2897 if (stack_parm == NULL_RTX)
2898 {
2899 int save = generating_concat_p;
2900 generating_concat_p = 0;
2901 stack_parm = gen_reg_rtx (mode);
2902 generating_concat_p = save;
2903 }
2904 }
2905 data->stack_parm = NULL;
2906 }
2907
2908 size = int_size_in_bytes (data->arg.type);
2909 size_stored = CEIL_ROUND (size, UNITS_PER_WORD);
2910 if (stack_parm == 0)
2911 {
2912 HOST_WIDE_INT parm_align
2913 = (STRICT_ALIGNMENT
2914 ? MAX (DECL_ALIGN (parm), BITS_PER_WORD) : DECL_ALIGN (parm));
2915
2916 SET_DECL_ALIGN (parm, parm_align);
2917 if (DECL_ALIGN (parm) > MAX_SUPPORTED_STACK_ALIGNMENT)
2918 {
2919 rtx allocsize = gen_int_mode (size_stored, Pmode);
2920 get_dynamic_stack_size (&allocsize, 0, DECL_ALIGN (parm), NULL);
2921 stack_parm = assign_stack_local (BLKmode, UINTVAL (allocsize),
2922 MAX_SUPPORTED_STACK_ALIGNMENT);
2923 rtx addr = align_dynamic_address (XEXP (stack_parm, 0),
2924 DECL_ALIGN (parm));
2925 mark_reg_pointer (addr, DECL_ALIGN (parm));
2926 stack_parm = gen_rtx_MEM (GET_MODE (stack_parm), addr);
2927 MEM_NOTRAP_P (stack_parm) = 1;
2928 }
2929 else
2930 stack_parm = assign_stack_local (BLKmode, size_stored,
2931 DECL_ALIGN (parm));
2932 if (known_eq (GET_MODE_SIZE (GET_MODE (entry_parm)), size))
2933 PUT_MODE (stack_parm, GET_MODE (entry_parm));
2934 set_mem_attributes (stack_parm, parm, 1);
2935 }
2936
2937 /* If a BLKmode arrives in registers, copy it to a stack slot. Handle
2938 calls that pass values in multiple non-contiguous locations. */
2939 if (REG_P (entry_parm) || GET_CODE (entry_parm) == PARALLEL)
2940 {
2941 rtx mem;
2942
2943 /* Note that we will be storing an integral number of words.
2944 So we have to be careful to ensure that we allocate an
2945 integral number of words. We do this above when we call
2946 assign_stack_local if space was not allocated in the argument
2947 list. If it was, this will not work if PARM_BOUNDARY is not
2948 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2949 if it becomes a problem. Exception is when BLKmode arrives
2950 with arguments not conforming to word_mode. */
2951
2952 if (data->stack_parm == 0)
2953 ;
2954 else if (GET_CODE (entry_parm) == PARALLEL)
2955 ;
2956 else
2957 gcc_assert (!size || !(PARM_BOUNDARY % BITS_PER_WORD));
2958
2959 mem = validize_mem (copy_rtx (stack_parm));
2960
2961 /* Handle values in multiple non-contiguous locations. */
2962 if (GET_CODE (entry_parm) == PARALLEL && !MEM_P (mem))
2963 emit_group_store (mem, entry_parm, data->arg.type, size);
2964 else if (GET_CODE (entry_parm) == PARALLEL)
2965 {
2966 push_to_sequence2 (all->first_conversion_insn,
2967 all->last_conversion_insn);
2968 emit_group_store (mem, entry_parm, data->arg.type, size);
2969 all->first_conversion_insn = get_insns ();
2970 all->last_conversion_insn = get_last_insn ();
2971 end_sequence ();
2972 in_conversion_seq = true;
2973 }
2974
2975 else if (size == 0)
2976 ;
2977
2978 /* If SIZE is that of a mode no bigger than a word, just use
2979 that mode's store operation. */
2980 else if (size <= UNITS_PER_WORD)
2981 {
2982 unsigned int bits = size * BITS_PER_UNIT;
2983 machine_mode mode = int_mode_for_size (bits, 0).else_blk ();
2984
2985 if (mode != BLKmode
2986 #ifdef BLOCK_REG_PADDING
2987 && (size == UNITS_PER_WORD
2988 || (BLOCK_REG_PADDING (mode, data->arg.type, 1)
2989 != (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
2990 #endif
2991 )
2992 {
2993 rtx reg;
2994
2995 /* We are really truncating a word_mode value containing
2996 SIZE bytes into a value of mode MODE. If such an
2997 operation requires no actual instructions, we can refer
2998 to the value directly in mode MODE, otherwise we must
2999 start with the register in word_mode and explicitly
3000 convert it. */
3001 if (targetm.truly_noop_truncation (size * BITS_PER_UNIT,
3002 BITS_PER_WORD))
3003 reg = gen_rtx_REG (mode, REGNO (entry_parm));
3004 else
3005 {
3006 reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
3007 reg = convert_to_mode (mode, copy_to_reg (reg), 1);
3008 }
3009 emit_move_insn (change_address (mem, mode, 0), reg);
3010 }
3011
3012 #ifdef BLOCK_REG_PADDING
3013 /* Storing the register in memory as a full word, as
3014 move_block_from_reg below would do, and then using the
3015 MEM in a smaller mode, has the effect of shifting right
3016 if BYTES_BIG_ENDIAN. If we're bypassing memory, the
3017 shifting must be explicit. */
3018 else if (!MEM_P (mem))
3019 {
3020 rtx x;
3021
3022 /* If the assert below fails, we should have taken the
3023 mode != BLKmode path above, unless we have downward
3024 padding of smaller-than-word arguments on a machine
3025 with little-endian bytes, which would likely require
3026 additional changes to work correctly. */
3027 gcc_checking_assert (BYTES_BIG_ENDIAN
3028 && (BLOCK_REG_PADDING (mode,
3029 data->arg.type, 1)
3030 == PAD_UPWARD));
3031
3032 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
3033
3034 x = gen_rtx_REG (word_mode, REGNO (entry_parm));
3035 x = expand_shift (RSHIFT_EXPR, word_mode, x, by,
3036 NULL_RTX, 1);
3037 x = force_reg (word_mode, x);
3038 x = gen_lowpart_SUBREG (GET_MODE (mem), x);
3039
3040 emit_move_insn (mem, x);
3041 }
3042 #endif
3043
3044 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
3045 machine must be aligned to the left before storing
3046 to memory. Note that the previous test doesn't
3047 handle all cases (e.g. SIZE == 3). */
3048 else if (size != UNITS_PER_WORD
3049 #ifdef BLOCK_REG_PADDING
3050 && (BLOCK_REG_PADDING (mode, data->arg.type, 1)
3051 == PAD_DOWNWARD)
3052 #else
3053 && BYTES_BIG_ENDIAN
3054 #endif
3055 )
3056 {
3057 rtx tem, x;
3058 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
3059 rtx reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
3060
3061 x = expand_shift (LSHIFT_EXPR, word_mode, reg, by, NULL_RTX, 1);
3062 tem = change_address (mem, word_mode, 0);
3063 emit_move_insn (tem, x);
3064 }
3065 else
3066 move_block_from_reg (REGNO (entry_parm), mem,
3067 size_stored / UNITS_PER_WORD);
3068 }
3069 else if (!MEM_P (mem))
3070 {
3071 gcc_checking_assert (size > UNITS_PER_WORD);
3072 #ifdef BLOCK_REG_PADDING
3073 gcc_checking_assert (BLOCK_REG_PADDING (GET_MODE (mem),
3074 data->arg.type, 0)
3075 == PAD_UPWARD);
3076 #endif
3077 emit_move_insn (mem, entry_parm);
3078 }
3079 else
3080 move_block_from_reg (REGNO (entry_parm), mem,
3081 size_stored / UNITS_PER_WORD);
3082 }
3083 else if (data->stack_parm == 0)
3084 {
3085 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3086 emit_block_move (stack_parm, data->entry_parm, GEN_INT (size),
3087 BLOCK_OP_NORMAL);
3088 all->first_conversion_insn = get_insns ();
3089 all->last_conversion_insn = get_last_insn ();
3090 end_sequence ();
3091 in_conversion_seq = true;
3092 }
3093
3094 if (target_reg)
3095 {
3096 if (!in_conversion_seq)
3097 emit_move_insn (target_reg, stack_parm);
3098 else
3099 {
3100 push_to_sequence2 (all->first_conversion_insn,
3101 all->last_conversion_insn);
3102 emit_move_insn (target_reg, stack_parm);
3103 all->first_conversion_insn = get_insns ();
3104 all->last_conversion_insn = get_last_insn ();
3105 end_sequence ();
3106 }
3107 stack_parm = target_reg;
3108 }
3109
3110 data->stack_parm = stack_parm;
3111 set_parm_rtl (parm, stack_parm);
3112 }
3113
3114 /* A subroutine of assign_parms. Allocate a pseudo to hold the current
3115 parameter. Get it there. Perform all ABI specified conversions. */
3116
3117 static void
3118 assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm,
3119 struct assign_parm_data_one *data)
3120 {
3121 rtx parmreg, validated_mem;
3122 rtx equiv_stack_parm;
3123 machine_mode promoted_nominal_mode;
3124 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (parm));
3125 bool did_conversion = false;
3126 bool need_conversion, moved;
3127 enum insn_code icode;
3128 rtx rtl;
3129
3130 /* Store the parm in a pseudoregister during the function, but we may
3131 need to do it in a wider mode. Using 2 here makes the result
3132 consistent with promote_decl_mode and thus expand_expr_real_1. */
3133 promoted_nominal_mode
3134 = promote_function_mode (data->nominal_type, data->nominal_mode, &unsignedp,
3135 TREE_TYPE (current_function_decl), 2);
3136
3137 parmreg = gen_reg_rtx (promoted_nominal_mode);
3138 if (!DECL_ARTIFICIAL (parm))
3139 mark_user_reg (parmreg);
3140
3141 /* If this was an item that we received a pointer to,
3142 set rtl appropriately. */
3143 if (data->passed_pointer)
3144 {
3145 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data->arg.type)), parmreg);
3146 set_mem_attributes (rtl, parm, 1);
3147 }
3148 else
3149 rtl = parmreg;
3150
3151 assign_parm_remove_parallels (data);
3152
3153 /* Copy the value into the register, thus bridging between
3154 assign_parm_find_data_types and expand_expr_real_1. */
3155
3156 equiv_stack_parm = data->stack_parm;
3157 validated_mem = validize_mem (copy_rtx (data->entry_parm));
3158
3159 need_conversion = (data->nominal_mode != data->passed_mode
3160 || promoted_nominal_mode != data->arg.mode);
3161 moved = false;
3162
3163 if (need_conversion
3164 && GET_MODE_CLASS (data->nominal_mode) == MODE_INT
3165 && data->nominal_mode == data->passed_mode
3166 && data->nominal_mode == GET_MODE (data->entry_parm))
3167 {
3168 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
3169 mode, by the caller. We now have to convert it to
3170 NOMINAL_MODE, if different. However, PARMREG may be in
3171 a different mode than NOMINAL_MODE if it is being stored
3172 promoted.
3173
3174 If ENTRY_PARM is a hard register, it might be in a register
3175 not valid for operating in its mode (e.g., an odd-numbered
3176 register for a DFmode). In that case, moves are the only
3177 thing valid, so we can't do a convert from there. This
3178 occurs when the calling sequence allow such misaligned
3179 usages.
3180
3181 In addition, the conversion may involve a call, which could
3182 clobber parameters which haven't been copied to pseudo
3183 registers yet.
3184
3185 First, we try to emit an insn which performs the necessary
3186 conversion. We verify that this insn does not clobber any
3187 hard registers. */
3188
3189 rtx op0, op1;
3190
3191 icode = can_extend_p (promoted_nominal_mode, data->passed_mode,
3192 unsignedp);
3193
3194 op0 = parmreg;
3195 op1 = validated_mem;
3196 if (icode != CODE_FOR_nothing
3197 && insn_operand_matches (icode, 0, op0)
3198 && insn_operand_matches (icode, 1, op1))
3199 {
3200 enum rtx_code code = unsignedp ? ZERO_EXTEND : SIGN_EXTEND;
3201 rtx_insn *insn, *insns;
3202 rtx t = op1;
3203 HARD_REG_SET hardregs;
3204
3205 start_sequence ();
3206 /* If op1 is a hard register that is likely spilled, first
3207 force it into a pseudo, otherwise combiner might extend
3208 its lifetime too much. */
3209 if (GET_CODE (t) == SUBREG)
3210 t = SUBREG_REG (t);
3211 if (REG_P (t)
3212 && HARD_REGISTER_P (t)
3213 && ! TEST_HARD_REG_BIT (fixed_reg_set, REGNO (t))
3214 && targetm.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (t))))
3215 {
3216 t = gen_reg_rtx (GET_MODE (op1));
3217 emit_move_insn (t, op1);
3218 }
3219 else
3220 t = op1;
3221 rtx_insn *pat = gen_extend_insn (op0, t, promoted_nominal_mode,
3222 data->passed_mode, unsignedp);
3223 emit_insn (pat);
3224 insns = get_insns ();
3225
3226 moved = true;
3227 CLEAR_HARD_REG_SET (hardregs);
3228 for (insn = insns; insn && moved; insn = NEXT_INSN (insn))
3229 {
3230 if (INSN_P (insn))
3231 note_stores (PATTERN (insn), record_hard_reg_sets,
3232 &hardregs);
3233 if (!hard_reg_set_empty_p (hardregs))
3234 moved = false;
3235 }
3236
3237 end_sequence ();
3238
3239 if (moved)
3240 {
3241 emit_insn (insns);
3242 if (equiv_stack_parm != NULL_RTX)
3243 equiv_stack_parm = gen_rtx_fmt_e (code, GET_MODE (parmreg),
3244 equiv_stack_parm);
3245 }
3246 }
3247 }
3248
3249 if (moved)
3250 /* Nothing to do. */
3251 ;
3252 else if (need_conversion)
3253 {
3254 /* We did not have an insn to convert directly, or the sequence
3255 generated appeared unsafe. We must first copy the parm to a
3256 pseudo reg, and save the conversion until after all
3257 parameters have been moved. */
3258
3259 int save_tree_used;
3260 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
3261
3262 emit_move_insn (tempreg, validated_mem);
3263
3264 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3265 tempreg = convert_to_mode (data->nominal_mode, tempreg, unsignedp);
3266
3267 if (partial_subreg_p (tempreg)
3268 && GET_MODE (tempreg) == data->nominal_mode
3269 && REG_P (SUBREG_REG (tempreg))
3270 && data->nominal_mode == data->passed_mode
3271 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (data->entry_parm))
3272 {
3273 /* The argument is already sign/zero extended, so note it
3274 into the subreg. */
3275 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
3276 SUBREG_PROMOTED_SET (tempreg, unsignedp);
3277 }
3278
3279 /* TREE_USED gets set erroneously during expand_assignment. */
3280 save_tree_used = TREE_USED (parm);
3281 SET_DECL_RTL (parm, rtl);
3282 expand_assignment (parm, make_tree (data->nominal_type, tempreg), false);
3283 SET_DECL_RTL (parm, NULL_RTX);
3284 TREE_USED (parm) = save_tree_used;
3285 all->first_conversion_insn = get_insns ();
3286 all->last_conversion_insn = get_last_insn ();
3287 end_sequence ();
3288
3289 did_conversion = true;
3290 }
3291 else if (MEM_P (data->entry_parm)
3292 && GET_MODE_ALIGNMENT (promoted_nominal_mode)
3293 > MEM_ALIGN (data->entry_parm)
3294 && (((icode = optab_handler (movmisalign_optab,
3295 promoted_nominal_mode))
3296 != CODE_FOR_nothing)
3297 || targetm.slow_unaligned_access (promoted_nominal_mode,
3298 MEM_ALIGN (data->entry_parm))))
3299 {
3300 if (icode != CODE_FOR_nothing)
3301 emit_insn (GEN_FCN (icode) (parmreg, validated_mem));
3302 else
3303 rtl = parmreg = extract_bit_field (validated_mem,
3304 GET_MODE_BITSIZE (promoted_nominal_mode), 0,
3305 unsignedp, parmreg,
3306 promoted_nominal_mode, VOIDmode, false, NULL);
3307 }
3308 else
3309 emit_move_insn (parmreg, validated_mem);
3310
3311 /* If we were passed a pointer but the actual value can safely live
3312 in a register, retrieve it and use it directly. */
3313 if (data->passed_pointer && TYPE_MODE (TREE_TYPE (parm)) != BLKmode)
3314 {
3315 /* We can't use nominal_mode, because it will have been set to
3316 Pmode above. We must use the actual mode of the parm. */
3317 if (use_register_for_decl (parm))
3318 {
3319 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
3320 mark_user_reg (parmreg);
3321 }
3322 else
3323 {
3324 int align = STACK_SLOT_ALIGNMENT (TREE_TYPE (parm),
3325 TYPE_MODE (TREE_TYPE (parm)),
3326 TYPE_ALIGN (TREE_TYPE (parm)));
3327 parmreg
3328 = assign_stack_local (TYPE_MODE (TREE_TYPE (parm)),
3329 GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (parm))),
3330 align);
3331 set_mem_attributes (parmreg, parm, 1);
3332 }
3333
3334 /* We need to preserve an address based on VIRTUAL_STACK_VARS_REGNUM for
3335 the debug info in case it is not legitimate. */
3336 if (GET_MODE (parmreg) != GET_MODE (rtl))
3337 {
3338 rtx tempreg = gen_reg_rtx (GET_MODE (rtl));
3339 int unsigned_p = TYPE_UNSIGNED (TREE_TYPE (parm));
3340
3341 push_to_sequence2 (all->first_conversion_insn,
3342 all->last_conversion_insn);
3343 emit_move_insn (tempreg, rtl);
3344 tempreg = convert_to_mode (GET_MODE (parmreg), tempreg, unsigned_p);
3345 emit_move_insn (MEM_P (parmreg) ? copy_rtx (parmreg) : parmreg,
3346 tempreg);
3347 all->first_conversion_insn = get_insns ();
3348 all->last_conversion_insn = get_last_insn ();
3349 end_sequence ();
3350
3351 did_conversion = true;
3352 }
3353 else
3354 emit_move_insn (MEM_P (parmreg) ? copy_rtx (parmreg) : parmreg, rtl);
3355
3356 rtl = parmreg;
3357
3358 /* STACK_PARM is the pointer, not the parm, and PARMREG is
3359 now the parm. */
3360 data->stack_parm = NULL;
3361 }
3362
3363 set_parm_rtl (parm, rtl);
3364
3365 /* Mark the register as eliminable if we did no conversion and it was
3366 copied from memory at a fixed offset, and the arg pointer was not
3367 copied to a pseudo-reg. If the arg pointer is a pseudo reg or the
3368 offset formed an invalid address, such memory-equivalences as we
3369 make here would screw up life analysis for it. */
3370 if (data->nominal_mode == data->passed_mode
3371 && !did_conversion
3372 && data->stack_parm != 0
3373 && MEM_P (data->stack_parm)
3374 && data->locate.offset.var == 0
3375 && reg_mentioned_p (virtual_incoming_args_rtx,
3376 XEXP (data->stack_parm, 0)))
3377 {
3378 rtx_insn *linsn = get_last_insn ();
3379 rtx_insn *sinsn;
3380 rtx set;
3381
3382 /* Mark complex types separately. */
3383 if (GET_CODE (parmreg) == CONCAT)
3384 {
3385 scalar_mode submode = GET_MODE_INNER (GET_MODE (parmreg));
3386 int regnor = REGNO (XEXP (parmreg, 0));
3387 int regnoi = REGNO (XEXP (parmreg, 1));
3388 rtx stackr = adjust_address_nv (data->stack_parm, submode, 0);
3389 rtx stacki = adjust_address_nv (data->stack_parm, submode,
3390 GET_MODE_SIZE (submode));
3391
3392 /* Scan backwards for the set of the real and
3393 imaginary parts. */
3394 for (sinsn = linsn; sinsn != 0;
3395 sinsn = prev_nonnote_insn (sinsn))
3396 {
3397 set = single_set (sinsn);
3398 if (set == 0)
3399 continue;
3400
3401 if (SET_DEST (set) == regno_reg_rtx [regnoi])
3402 set_unique_reg_note (sinsn, REG_EQUIV, stacki);
3403 else if (SET_DEST (set) == regno_reg_rtx [regnor])
3404 set_unique_reg_note (sinsn, REG_EQUIV, stackr);
3405 }
3406 }
3407 else
3408 set_dst_reg_note (linsn, REG_EQUIV, equiv_stack_parm, parmreg);
3409 }
3410
3411 /* For pointer data type, suggest pointer register. */
3412 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3413 mark_reg_pointer (parmreg,
3414 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
3415 }
3416
3417 /* A subroutine of assign_parms. Allocate stack space to hold the current
3418 parameter. Get it there. Perform all ABI specified conversions. */
3419
3420 static void
3421 assign_parm_setup_stack (struct assign_parm_data_all *all, tree parm,
3422 struct assign_parm_data_one *data)
3423 {
3424 /* Value must be stored in the stack slot STACK_PARM during function
3425 execution. */
3426 bool to_conversion = false;
3427
3428 assign_parm_remove_parallels (data);
3429
3430 if (data->arg.mode != data->nominal_mode)
3431 {
3432 /* Conversion is required. */
3433 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
3434
3435 emit_move_insn (tempreg, validize_mem (copy_rtx (data->entry_parm)));
3436
3437 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3438 to_conversion = true;
3439
3440 data->entry_parm = convert_to_mode (data->nominal_mode, tempreg,
3441 TYPE_UNSIGNED (TREE_TYPE (parm)));
3442
3443 if (data->stack_parm)
3444 {
3445 poly_int64 offset
3446 = subreg_lowpart_offset (data->nominal_mode,
3447 GET_MODE (data->stack_parm));
3448 /* ??? This may need a big-endian conversion on sparc64. */
3449 data->stack_parm
3450 = adjust_address (data->stack_parm, data->nominal_mode, 0);
3451 if (maybe_ne (offset, 0) && MEM_OFFSET_KNOWN_P (data->stack_parm))
3452 set_mem_offset (data->stack_parm,
3453 MEM_OFFSET (data->stack_parm) + offset);
3454 }
3455 }
3456
3457 if (data->entry_parm != data->stack_parm)
3458 {
3459 rtx src, dest;
3460
3461 if (data->stack_parm == 0)
3462 {
3463 int align = STACK_SLOT_ALIGNMENT (data->arg.type,
3464 GET_MODE (data->entry_parm),
3465 TYPE_ALIGN (data->arg.type));
3466 data->stack_parm
3467 = assign_stack_local (GET_MODE (data->entry_parm),
3468 GET_MODE_SIZE (GET_MODE (data->entry_parm)),
3469 align);
3470 set_mem_attributes (data->stack_parm, parm, 1);
3471 }
3472
3473 dest = validize_mem (copy_rtx (data->stack_parm));
3474 src = validize_mem (copy_rtx (data->entry_parm));
3475
3476 if (MEM_P (src))
3477 {
3478 /* Use a block move to handle potentially misaligned entry_parm. */
3479 if (!to_conversion)
3480 push_to_sequence2 (all->first_conversion_insn,
3481 all->last_conversion_insn);
3482 to_conversion = true;
3483
3484 emit_block_move (dest, src,
3485 GEN_INT (int_size_in_bytes (data->arg.type)),
3486 BLOCK_OP_NORMAL);
3487 }
3488 else
3489 {
3490 if (!REG_P (src))
3491 src = force_reg (GET_MODE (src), src);
3492 emit_move_insn (dest, src);
3493 }
3494 }
3495
3496 if (to_conversion)
3497 {
3498 all->first_conversion_insn = get_insns ();
3499 all->last_conversion_insn = get_last_insn ();
3500 end_sequence ();
3501 }
3502
3503 set_parm_rtl (parm, data->stack_parm);
3504 }
3505
3506 /* A subroutine of assign_parms. If the ABI splits complex arguments, then
3507 undo the frobbing that we did in assign_parms_augmented_arg_list. */
3508
3509 static void
3510 assign_parms_unsplit_complex (struct assign_parm_data_all *all,
3511 vec<tree> fnargs)
3512 {
3513 tree parm;
3514 tree orig_fnargs = all->orig_fnargs;
3515 unsigned i = 0;
3516
3517 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm), ++i)
3518 {
3519 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
3520 && targetm.calls.split_complex_arg (TREE_TYPE (parm)))
3521 {
3522 rtx tmp, real, imag;
3523 scalar_mode inner = GET_MODE_INNER (DECL_MODE (parm));
3524
3525 real = DECL_RTL (fnargs[i]);
3526 imag = DECL_RTL (fnargs[i + 1]);
3527 if (inner != GET_MODE (real))
3528 {
3529 real = gen_lowpart_SUBREG (inner, real);
3530 imag = gen_lowpart_SUBREG (inner, imag);
3531 }
3532
3533 if (TREE_ADDRESSABLE (parm))
3534 {
3535 rtx rmem, imem;
3536 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (parm));
3537 int align = STACK_SLOT_ALIGNMENT (TREE_TYPE (parm),
3538 DECL_MODE (parm),
3539 TYPE_ALIGN (TREE_TYPE (parm)));
3540
3541 /* split_complex_arg put the real and imag parts in
3542 pseudos. Move them to memory. */
3543 tmp = assign_stack_local (DECL_MODE (parm), size, align);
3544 set_mem_attributes (tmp, parm, 1);
3545 rmem = adjust_address_nv (tmp, inner, 0);
3546 imem = adjust_address_nv (tmp, inner, GET_MODE_SIZE (inner));
3547 push_to_sequence2 (all->first_conversion_insn,
3548 all->last_conversion_insn);
3549 emit_move_insn (rmem, real);
3550 emit_move_insn (imem, imag);
3551 all->first_conversion_insn = get_insns ();
3552 all->last_conversion_insn = get_last_insn ();
3553 end_sequence ();
3554 }
3555 else
3556 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
3557 set_parm_rtl (parm, tmp);
3558
3559 real = DECL_INCOMING_RTL (fnargs[i]);
3560 imag = DECL_INCOMING_RTL (fnargs[i + 1]);
3561 if (inner != GET_MODE (real))
3562 {
3563 real = gen_lowpart_SUBREG (inner, real);
3564 imag = gen_lowpart_SUBREG (inner, imag);
3565 }
3566 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
3567 set_decl_incoming_rtl (parm, tmp, false);
3568 i++;
3569 }
3570 }
3571 }
3572
3573 /* Assign RTL expressions to the function's parameters. This may involve
3574 copying them into registers and using those registers as the DECL_RTL. */
3575
3576 static void
3577 assign_parms (tree fndecl)
3578 {
3579 struct assign_parm_data_all all;
3580 tree parm;
3581 vec<tree> fnargs;
3582 unsigned i;
3583
3584 crtl->args.internal_arg_pointer
3585 = targetm.calls.internal_arg_pointer ();
3586
3587 assign_parms_initialize_all (&all);
3588 fnargs = assign_parms_augmented_arg_list (&all);
3589
3590 FOR_EACH_VEC_ELT (fnargs, i, parm)
3591 {
3592 struct assign_parm_data_one data;
3593
3594 /* Extract the type of PARM; adjust it according to ABI. */
3595 assign_parm_find_data_types (&all, parm, &data);
3596
3597 /* Early out for errors and void parameters. */
3598 if (data.passed_mode == VOIDmode)
3599 {
3600 SET_DECL_RTL (parm, const0_rtx);
3601 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
3602 continue;
3603 }
3604
3605 /* Estimate stack alignment from parameter alignment. */
3606 if (SUPPORTS_STACK_ALIGNMENT)
3607 {
3608 unsigned int align
3609 = targetm.calls.function_arg_boundary (data.arg.mode,
3610 data.arg.type);
3611 align = MINIMUM_ALIGNMENT (data.arg.type, data.arg.mode, align);
3612 if (TYPE_ALIGN (data.nominal_type) > align)
3613 align = MINIMUM_ALIGNMENT (data.nominal_type,
3614 TYPE_MODE (data.nominal_type),
3615 TYPE_ALIGN (data.nominal_type));
3616 if (crtl->stack_alignment_estimated < align)
3617 {
3618 gcc_assert (!crtl->stack_realign_processed);
3619 crtl->stack_alignment_estimated = align;
3620 }
3621 }
3622
3623 /* Find out where the parameter arrives in this function. */
3624 assign_parm_find_entry_rtl (&all, &data);
3625
3626 /* Find out where stack space for this parameter might be. */
3627 if (assign_parm_is_stack_parm (&all, &data))
3628 {
3629 assign_parm_find_stack_rtl (parm, &data);
3630 assign_parm_adjust_entry_rtl (&data);
3631 }
3632 /* Record permanently how this parm was passed. */
3633 if (data.passed_pointer)
3634 {
3635 rtx incoming_rtl
3636 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data.arg.type)),
3637 data.entry_parm);
3638 set_decl_incoming_rtl (parm, incoming_rtl, true);
3639 }
3640 else
3641 set_decl_incoming_rtl (parm, data.entry_parm, false);
3642
3643 assign_parm_adjust_stack_rtl (&data);
3644
3645 if (assign_parm_setup_block_p (&data))
3646 assign_parm_setup_block (&all, parm, &data);
3647 else if (data.passed_pointer || use_register_for_decl (parm))
3648 assign_parm_setup_reg (&all, parm, &data);
3649 else
3650 assign_parm_setup_stack (&all, parm, &data);
3651
3652 if (cfun->stdarg && !DECL_CHAIN (parm))
3653 assign_parms_setup_varargs (&all, &data, false);
3654
3655 /* Update info on where next arg arrives in registers. */
3656 targetm.calls.function_arg_advance (all.args_so_far, data.arg);
3657 }
3658
3659 if (targetm.calls.split_complex_arg)
3660 assign_parms_unsplit_complex (&all, fnargs);
3661
3662 fnargs.release ();
3663
3664 /* Output all parameter conversion instructions (possibly including calls)
3665 now that all parameters have been copied out of hard registers. */
3666 emit_insn (all.first_conversion_insn);
3667
3668 /* Estimate reload stack alignment from scalar return mode. */
3669 if (SUPPORTS_STACK_ALIGNMENT)
3670 {
3671 if (DECL_RESULT (fndecl))
3672 {
3673 tree type = TREE_TYPE (DECL_RESULT (fndecl));
3674 machine_mode mode = TYPE_MODE (type);
3675
3676 if (mode != BLKmode
3677 && mode != VOIDmode
3678 && !AGGREGATE_TYPE_P (type))
3679 {
3680 unsigned int align = GET_MODE_ALIGNMENT (mode);
3681 if (crtl->stack_alignment_estimated < align)
3682 {
3683 gcc_assert (!crtl->stack_realign_processed);
3684 crtl->stack_alignment_estimated = align;
3685 }
3686 }
3687 }
3688 }
3689
3690 /* If we are receiving a struct value address as the first argument, set up
3691 the RTL for the function result. As this might require code to convert
3692 the transmitted address to Pmode, we do this here to ensure that possible
3693 preliminary conversions of the address have been emitted already. */
3694 if (all.function_result_decl)
3695 {
3696 tree result = DECL_RESULT (current_function_decl);
3697 rtx addr = DECL_RTL (all.function_result_decl);
3698 rtx x;
3699
3700 if (DECL_BY_REFERENCE (result))
3701 {
3702 SET_DECL_VALUE_EXPR (result, all.function_result_decl);
3703 x = addr;
3704 }
3705 else
3706 {
3707 SET_DECL_VALUE_EXPR (result,
3708 build1 (INDIRECT_REF, TREE_TYPE (result),
3709 all.function_result_decl));
3710 addr = convert_memory_address (Pmode, addr);
3711 x = gen_rtx_MEM (DECL_MODE (result), addr);
3712 set_mem_attributes (x, result, 1);
3713 }
3714
3715 DECL_HAS_VALUE_EXPR_P (result) = 1;
3716
3717 set_parm_rtl (result, x);
3718 }
3719
3720 /* We have aligned all the args, so add space for the pretend args. */
3721 crtl->args.pretend_args_size = all.pretend_args_size;
3722 all.stack_args_size.constant += all.extra_pretend_bytes;
3723 crtl->args.size = all.stack_args_size.constant;
3724
3725 /* Adjust function incoming argument size for alignment and
3726 minimum length. */
3727
3728 crtl->args.size = upper_bound (crtl->args.size, all.reg_parm_stack_space);
3729 crtl->args.size = aligned_upper_bound (crtl->args.size,
3730 PARM_BOUNDARY / BITS_PER_UNIT);
3731
3732 if (ARGS_GROW_DOWNWARD)
3733 {
3734 crtl->args.arg_offset_rtx
3735 = (all.stack_args_size.var == 0
3736 ? gen_int_mode (-all.stack_args_size.constant, Pmode)
3737 : expand_expr (size_diffop (all.stack_args_size.var,
3738 size_int (-all.stack_args_size.constant)),
3739 NULL_RTX, VOIDmode, EXPAND_NORMAL));
3740 }
3741 else
3742 crtl->args.arg_offset_rtx = ARGS_SIZE_RTX (all.stack_args_size);
3743
3744 /* See how many bytes, if any, of its args a function should try to pop
3745 on return. */
3746
3747 crtl->args.pops_args = targetm.calls.return_pops_args (fndecl,
3748 TREE_TYPE (fndecl),
3749 crtl->args.size);
3750
3751 /* For stdarg.h function, save info about
3752 regs and stack space used by the named args. */
3753
3754 crtl->args.info = all.args_so_far_v;
3755
3756 /* Set the rtx used for the function return value. Put this in its
3757 own variable so any optimizers that need this information don't have
3758 to include tree.h. Do this here so it gets done when an inlined
3759 function gets output. */
3760
3761 crtl->return_rtx
3762 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
3763 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
3764
3765 /* If scalar return value was computed in a pseudo-reg, or was a named
3766 return value that got dumped to the stack, copy that to the hard
3767 return register. */
3768 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
3769 {
3770 tree decl_result = DECL_RESULT (fndecl);
3771 rtx decl_rtl = DECL_RTL (decl_result);
3772
3773 if (REG_P (decl_rtl)
3774 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
3775 : DECL_REGISTER (decl_result))
3776 {
3777 rtx real_decl_rtl;
3778
3779 real_decl_rtl = targetm.calls.function_value (TREE_TYPE (decl_result),
3780 fndecl, true);
3781 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
3782 /* The delay slot scheduler assumes that crtl->return_rtx
3783 holds the hard register containing the return value, not a
3784 temporary pseudo. */
3785 crtl->return_rtx = real_decl_rtl;
3786 }
3787 }
3788 }
3789
3790 /* A subroutine of gimplify_parameters, invoked via walk_tree.
3791 For all seen types, gimplify their sizes. */
3792
3793 static tree
3794 gimplify_parm_type (tree *tp, int *walk_subtrees, void *data)
3795 {
3796 tree t = *tp;
3797
3798 *walk_subtrees = 0;
3799 if (TYPE_P (t))
3800 {
3801 if (POINTER_TYPE_P (t))
3802 *walk_subtrees = 1;
3803 else if (TYPE_SIZE (t) && !TREE_CONSTANT (TYPE_SIZE (t))
3804 && !TYPE_SIZES_GIMPLIFIED (t))
3805 {
3806 gimplify_type_sizes (t, (gimple_seq *) data);
3807 *walk_subtrees = 1;
3808 }
3809 }
3810
3811 return NULL;
3812 }
3813
3814 /* Gimplify the parameter list for current_function_decl. This involves
3815 evaluating SAVE_EXPRs of variable sized parameters and generating code
3816 to implement callee-copies reference parameters. Returns a sequence of
3817 statements to add to the beginning of the function. */
3818
3819 gimple_seq
3820 gimplify_parameters (gimple_seq *cleanup)
3821 {
3822 struct assign_parm_data_all all;
3823 tree parm;
3824 gimple_seq stmts = NULL;
3825 vec<tree> fnargs;
3826 unsigned i;
3827
3828 assign_parms_initialize_all (&all);
3829 fnargs = assign_parms_augmented_arg_list (&all);
3830
3831 FOR_EACH_VEC_ELT (fnargs, i, parm)
3832 {
3833 struct assign_parm_data_one data;
3834
3835 /* Extract the type of PARM; adjust it according to ABI. */
3836 assign_parm_find_data_types (&all, parm, &data);
3837
3838 /* Early out for errors and void parameters. */
3839 if (data.passed_mode == VOIDmode || DECL_SIZE (parm) == NULL)
3840 continue;
3841
3842 /* Update info on where next arg arrives in registers. */
3843 targetm.calls.function_arg_advance (all.args_so_far, data.arg);
3844
3845 /* ??? Once upon a time variable_size stuffed parameter list
3846 SAVE_EXPRs (amongst others) onto a pending sizes list. This
3847 turned out to be less than manageable in the gimple world.
3848 Now we have to hunt them down ourselves. */
3849 walk_tree_without_duplicates (&data.arg.type,
3850 gimplify_parm_type, &stmts);
3851
3852 if (TREE_CODE (DECL_SIZE_UNIT (parm)) != INTEGER_CST)
3853 {
3854 gimplify_one_sizepos (&DECL_SIZE (parm), &stmts);
3855 gimplify_one_sizepos (&DECL_SIZE_UNIT (parm), &stmts);
3856 }
3857
3858 if (data.passed_pointer)
3859 {
3860 tree type = TREE_TYPE (data.arg.type);
3861 function_arg_info orig_arg (type, data.arg.named);
3862 if (reference_callee_copied (&all.args_so_far_v, orig_arg))
3863 {
3864 tree local, t;
3865
3866 /* For constant-sized objects, this is trivial; for
3867 variable-sized objects, we have to play games. */
3868 if (TREE_CODE (DECL_SIZE_UNIT (parm)) == INTEGER_CST
3869 && !(flag_stack_check == GENERIC_STACK_CHECK
3870 && compare_tree_int (DECL_SIZE_UNIT (parm),
3871 STACK_CHECK_MAX_VAR_SIZE) > 0))
3872 {
3873 local = create_tmp_var (type, get_name (parm));
3874 DECL_IGNORED_P (local) = 0;
3875 /* If PARM was addressable, move that flag over
3876 to the local copy, as its address will be taken,
3877 not the PARMs. Keep the parms address taken
3878 as we'll query that flag during gimplification. */
3879 if (TREE_ADDRESSABLE (parm))
3880 TREE_ADDRESSABLE (local) = 1;
3881 else if (TREE_CODE (type) == COMPLEX_TYPE
3882 || TREE_CODE (type) == VECTOR_TYPE)
3883 DECL_GIMPLE_REG_P (local) = 1;
3884
3885 if (!is_gimple_reg (local)
3886 && flag_stack_reuse != SR_NONE)
3887 {
3888 tree clobber = build_constructor (type, NULL);
3889 gimple *clobber_stmt;
3890 TREE_THIS_VOLATILE (clobber) = 1;
3891 clobber_stmt = gimple_build_assign (local, clobber);
3892 gimple_seq_add_stmt (cleanup, clobber_stmt);
3893 }
3894 }
3895 else
3896 {
3897 tree ptr_type, addr;
3898
3899 ptr_type = build_pointer_type (type);
3900 addr = create_tmp_reg (ptr_type, get_name (parm));
3901 DECL_IGNORED_P (addr) = 0;
3902 local = build_fold_indirect_ref (addr);
3903
3904 t = build_alloca_call_expr (DECL_SIZE_UNIT (parm),
3905 DECL_ALIGN (parm),
3906 max_int_size_in_bytes (type));
3907 /* The call has been built for a variable-sized object. */
3908 CALL_ALLOCA_FOR_VAR_P (t) = 1;
3909 t = fold_convert (ptr_type, t);
3910 t = build2 (MODIFY_EXPR, TREE_TYPE (addr), addr, t);
3911 gimplify_and_add (t, &stmts);
3912 }
3913
3914 gimplify_assign (local, parm, &stmts);
3915
3916 SET_DECL_VALUE_EXPR (parm, local);
3917 DECL_HAS_VALUE_EXPR_P (parm) = 1;
3918 }
3919 }
3920 }
3921
3922 fnargs.release ();
3923
3924 return stmts;
3925 }
3926 \f
3927 /* Compute the size and offset from the start of the stacked arguments for a
3928 parm passed in mode PASSED_MODE and with type TYPE.
3929
3930 INITIAL_OFFSET_PTR points to the current offset into the stacked
3931 arguments.
3932
3933 The starting offset and size for this parm are returned in
3934 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
3935 nonzero, the offset is that of stack slot, which is returned in
3936 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
3937 padding required from the initial offset ptr to the stack slot.
3938
3939 IN_REGS is nonzero if the argument will be passed in registers. It will
3940 never be set if REG_PARM_STACK_SPACE is not defined.
3941
3942 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
3943 for arguments which are passed in registers.
3944
3945 FNDECL is the function in which the argument was defined.
3946
3947 There are two types of rounding that are done. The first, controlled by
3948 TARGET_FUNCTION_ARG_BOUNDARY, forces the offset from the start of the
3949 argument list to be aligned to the specific boundary (in bits). This
3950 rounding affects the initial and starting offsets, but not the argument
3951 size.
3952
3953 The second, controlled by TARGET_FUNCTION_ARG_PADDING and PARM_BOUNDARY,
3954 optionally rounds the size of the parm to PARM_BOUNDARY. The
3955 initial offset is not affected by this rounding, while the size always
3956 is and the starting offset may be. */
3957
3958 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
3959 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
3960 callers pass in the total size of args so far as
3961 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
3962
3963 void
3964 locate_and_pad_parm (machine_mode passed_mode, tree type, int in_regs,
3965 int reg_parm_stack_space, int partial,
3966 tree fndecl ATTRIBUTE_UNUSED,
3967 struct args_size *initial_offset_ptr,
3968 struct locate_and_pad_arg_data *locate)
3969 {
3970 tree sizetree;
3971 pad_direction where_pad;
3972 unsigned int boundary, round_boundary;
3973 int part_size_in_regs;
3974
3975 /* If we have found a stack parm before we reach the end of the
3976 area reserved for registers, skip that area. */
3977 if (! in_regs)
3978 {
3979 if (reg_parm_stack_space > 0)
3980 {
3981 if (initial_offset_ptr->var
3982 || !ordered_p (initial_offset_ptr->constant,
3983 reg_parm_stack_space))
3984 {
3985 initial_offset_ptr->var
3986 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
3987 ssize_int (reg_parm_stack_space));
3988 initial_offset_ptr->constant = 0;
3989 }
3990 else
3991 initial_offset_ptr->constant
3992 = ordered_max (initial_offset_ptr->constant,
3993 reg_parm_stack_space);
3994 }
3995 }
3996
3997 part_size_in_regs = (reg_parm_stack_space == 0 ? partial : 0);
3998
3999 sizetree = (type
4000 ? arg_size_in_bytes (type)
4001 : size_int (GET_MODE_SIZE (passed_mode)));
4002 where_pad = targetm.calls.function_arg_padding (passed_mode, type);
4003 boundary = targetm.calls.function_arg_boundary (passed_mode, type);
4004 round_boundary = targetm.calls.function_arg_round_boundary (passed_mode,
4005 type);
4006 locate->where_pad = where_pad;
4007
4008 /* Alignment can't exceed MAX_SUPPORTED_STACK_ALIGNMENT. */
4009 if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
4010 boundary = MAX_SUPPORTED_STACK_ALIGNMENT;
4011
4012 locate->boundary = boundary;
4013
4014 if (SUPPORTS_STACK_ALIGNMENT)
4015 {
4016 /* stack_alignment_estimated can't change after stack has been
4017 realigned. */
4018 if (crtl->stack_alignment_estimated < boundary)
4019 {
4020 if (!crtl->stack_realign_processed)
4021 crtl->stack_alignment_estimated = boundary;
4022 else
4023 {
4024 /* If stack is realigned and stack alignment value
4025 hasn't been finalized, it is OK not to increase
4026 stack_alignment_estimated. The bigger alignment
4027 requirement is recorded in stack_alignment_needed
4028 below. */
4029 gcc_assert (!crtl->stack_realign_finalized
4030 && crtl->stack_realign_needed);
4031 }
4032 }
4033 }
4034
4035 if (ARGS_GROW_DOWNWARD)
4036 {
4037 locate->slot_offset.constant = -initial_offset_ptr->constant;
4038 if (initial_offset_ptr->var)
4039 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
4040 initial_offset_ptr->var);
4041
4042 {
4043 tree s2 = sizetree;
4044 if (where_pad != PAD_NONE
4045 && (!tree_fits_uhwi_p (sizetree)
4046 || (tree_to_uhwi (sizetree) * BITS_PER_UNIT) % round_boundary))
4047 s2 = round_up (s2, round_boundary / BITS_PER_UNIT);
4048 SUB_PARM_SIZE (locate->slot_offset, s2);
4049 }
4050
4051 locate->slot_offset.constant += part_size_in_regs;
4052
4053 if (!in_regs || reg_parm_stack_space > 0)
4054 pad_to_arg_alignment (&locate->slot_offset, boundary,
4055 &locate->alignment_pad);
4056
4057 locate->size.constant = (-initial_offset_ptr->constant
4058 - locate->slot_offset.constant);
4059 if (initial_offset_ptr->var)
4060 locate->size.var = size_binop (MINUS_EXPR,
4061 size_binop (MINUS_EXPR,
4062 ssize_int (0),
4063 initial_offset_ptr->var),
4064 locate->slot_offset.var);
4065
4066 /* Pad_below needs the pre-rounded size to know how much to pad
4067 below. */
4068 locate->offset = locate->slot_offset;
4069 if (where_pad == PAD_DOWNWARD)
4070 pad_below (&locate->offset, passed_mode, sizetree);
4071
4072 }
4073 else
4074 {
4075 if (!in_regs || reg_parm_stack_space > 0)
4076 pad_to_arg_alignment (initial_offset_ptr, boundary,
4077 &locate->alignment_pad);
4078 locate->slot_offset = *initial_offset_ptr;
4079
4080 #ifdef PUSH_ROUNDING
4081 if (passed_mode != BLKmode)
4082 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
4083 #endif
4084
4085 /* Pad_below needs the pre-rounded size to know how much to pad below
4086 so this must be done before rounding up. */
4087 locate->offset = locate->slot_offset;
4088 if (where_pad == PAD_DOWNWARD)
4089 pad_below (&locate->offset, passed_mode, sizetree);
4090
4091 if (where_pad != PAD_NONE
4092 && (!tree_fits_uhwi_p (sizetree)
4093 || (tree_to_uhwi (sizetree) * BITS_PER_UNIT) % round_boundary))
4094 sizetree = round_up (sizetree, round_boundary / BITS_PER_UNIT);
4095
4096 ADD_PARM_SIZE (locate->size, sizetree);
4097
4098 locate->size.constant -= part_size_in_regs;
4099 }
4100
4101 locate->offset.constant
4102 += targetm.calls.function_arg_offset (passed_mode, type);
4103 }
4104
4105 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
4106 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
4107
4108 static void
4109 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
4110 struct args_size *alignment_pad)
4111 {
4112 tree save_var = NULL_TREE;
4113 poly_int64 save_constant = 0;
4114 int boundary_in_bytes = boundary / BITS_PER_UNIT;
4115 poly_int64 sp_offset = STACK_POINTER_OFFSET;
4116
4117 #ifdef SPARC_STACK_BOUNDARY_HACK
4118 /* ??? The SPARC port may claim a STACK_BOUNDARY higher than
4119 the real alignment of %sp. However, when it does this, the
4120 alignment of %sp+STACK_POINTER_OFFSET is STACK_BOUNDARY. */
4121 if (SPARC_STACK_BOUNDARY_HACK)
4122 sp_offset = 0;
4123 #endif
4124
4125 if (boundary > PARM_BOUNDARY)
4126 {
4127 save_var = offset_ptr->var;
4128 save_constant = offset_ptr->constant;
4129 }
4130
4131 alignment_pad->var = NULL_TREE;
4132 alignment_pad->constant = 0;
4133
4134 if (boundary > BITS_PER_UNIT)
4135 {
4136 int misalign;
4137 if (offset_ptr->var
4138 || !known_misalignment (offset_ptr->constant + sp_offset,
4139 boundary_in_bytes, &misalign))
4140 {
4141 tree sp_offset_tree = ssize_int (sp_offset);
4142 tree offset = size_binop (PLUS_EXPR,
4143 ARGS_SIZE_TREE (*offset_ptr),
4144 sp_offset_tree);
4145 tree rounded;
4146 if (ARGS_GROW_DOWNWARD)
4147 rounded = round_down (offset, boundary / BITS_PER_UNIT);
4148 else
4149 rounded = round_up (offset, boundary / BITS_PER_UNIT);
4150
4151 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
4152 /* ARGS_SIZE_TREE includes constant term. */
4153 offset_ptr->constant = 0;
4154 if (boundary > PARM_BOUNDARY)
4155 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
4156 save_var);
4157 }
4158 else
4159 {
4160 if (ARGS_GROW_DOWNWARD)
4161 offset_ptr->constant -= misalign;
4162 else
4163 offset_ptr->constant += -misalign & (boundary_in_bytes - 1);
4164
4165 if (boundary > PARM_BOUNDARY)
4166 alignment_pad->constant = offset_ptr->constant - save_constant;
4167 }
4168 }
4169 }
4170
4171 static void
4172 pad_below (struct args_size *offset_ptr, machine_mode passed_mode, tree sizetree)
4173 {
4174 unsigned int align = PARM_BOUNDARY / BITS_PER_UNIT;
4175 int misalign;
4176 if (passed_mode != BLKmode
4177 && known_misalignment (GET_MODE_SIZE (passed_mode), align, &misalign))
4178 offset_ptr->constant += -misalign & (align - 1);
4179 else
4180 {
4181 if (TREE_CODE (sizetree) != INTEGER_CST
4182 || (TREE_INT_CST_LOW (sizetree) & (align - 1)) != 0)
4183 {
4184 /* Round the size up to multiple of PARM_BOUNDARY bits. */
4185 tree s2 = round_up (sizetree, align);
4186 /* Add it in. */
4187 ADD_PARM_SIZE (*offset_ptr, s2);
4188 SUB_PARM_SIZE (*offset_ptr, sizetree);
4189 }
4190 }
4191 }
4192 \f
4193
4194 /* True if register REGNO was alive at a place where `setjmp' was
4195 called and was set more than once or is an argument. Such regs may
4196 be clobbered by `longjmp'. */
4197
4198 static bool
4199 regno_clobbered_at_setjmp (bitmap setjmp_crosses, int regno)
4200 {
4201 /* There appear to be cases where some local vars never reach the
4202 backend but have bogus regnos. */
4203 if (regno >= max_reg_num ())
4204 return false;
4205
4206 return ((REG_N_SETS (regno) > 1
4207 || REGNO_REG_SET_P (df_get_live_out (ENTRY_BLOCK_PTR_FOR_FN (cfun)),
4208 regno))
4209 && REGNO_REG_SET_P (setjmp_crosses, regno));
4210 }
4211
4212 /* Walk the tree of blocks describing the binding levels within a
4213 function and warn about variables the might be killed by setjmp or
4214 vfork. This is done after calling flow_analysis before register
4215 allocation since that will clobber the pseudo-regs to hard
4216 regs. */
4217
4218 static void
4219 setjmp_vars_warning (bitmap setjmp_crosses, tree block)
4220 {
4221 tree decl, sub;
4222
4223 for (decl = BLOCK_VARS (block); decl; decl = DECL_CHAIN (decl))
4224 {
4225 if (VAR_P (decl)
4226 && DECL_RTL_SET_P (decl)
4227 && REG_P (DECL_RTL (decl))
4228 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
4229 warning (OPT_Wclobbered, "variable %q+D might be clobbered by"
4230 " %<longjmp%> or %<vfork%>", decl);
4231 }
4232
4233 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = BLOCK_CHAIN (sub))
4234 setjmp_vars_warning (setjmp_crosses, sub);
4235 }
4236
4237 /* Do the appropriate part of setjmp_vars_warning
4238 but for arguments instead of local variables. */
4239
4240 static void
4241 setjmp_args_warning (bitmap setjmp_crosses)
4242 {
4243 tree decl;
4244 for (decl = DECL_ARGUMENTS (current_function_decl);
4245 decl; decl = DECL_CHAIN (decl))
4246 if (DECL_RTL (decl) != 0
4247 && REG_P (DECL_RTL (decl))
4248 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
4249 warning (OPT_Wclobbered,
4250 "argument %q+D might be clobbered by %<longjmp%> or %<vfork%>",
4251 decl);
4252 }
4253
4254 /* Generate warning messages for variables live across setjmp. */
4255
4256 void
4257 generate_setjmp_warnings (void)
4258 {
4259 bitmap setjmp_crosses = regstat_get_setjmp_crosses ();
4260
4261 if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS
4262 || bitmap_empty_p (setjmp_crosses))
4263 return;
4264
4265 setjmp_vars_warning (setjmp_crosses, DECL_INITIAL (current_function_decl));
4266 setjmp_args_warning (setjmp_crosses);
4267 }
4268
4269 \f
4270 /* Reverse the order of elements in the fragment chain T of blocks,
4271 and return the new head of the chain (old last element).
4272 In addition to that clear BLOCK_SAME_RANGE flags when needed
4273 and adjust BLOCK_SUPERCONTEXT from the super fragment to
4274 its super fragment origin. */
4275
4276 static tree
4277 block_fragments_nreverse (tree t)
4278 {
4279 tree prev = 0, block, next, prev_super = 0;
4280 tree super = BLOCK_SUPERCONTEXT (t);
4281 if (BLOCK_FRAGMENT_ORIGIN (super))
4282 super = BLOCK_FRAGMENT_ORIGIN (super);
4283 for (block = t; block; block = next)
4284 {
4285 next = BLOCK_FRAGMENT_CHAIN (block);
4286 BLOCK_FRAGMENT_CHAIN (block) = prev;
4287 if ((prev && !BLOCK_SAME_RANGE (prev))
4288 || (BLOCK_FRAGMENT_CHAIN (BLOCK_SUPERCONTEXT (block))
4289 != prev_super))
4290 BLOCK_SAME_RANGE (block) = 0;
4291 prev_super = BLOCK_SUPERCONTEXT (block);
4292 BLOCK_SUPERCONTEXT (block) = super;
4293 prev = block;
4294 }
4295 t = BLOCK_FRAGMENT_ORIGIN (t);
4296 if (BLOCK_FRAGMENT_CHAIN (BLOCK_SUPERCONTEXT (t))
4297 != prev_super)
4298 BLOCK_SAME_RANGE (t) = 0;
4299 BLOCK_SUPERCONTEXT (t) = super;
4300 return prev;
4301 }
4302
4303 /* Reverse the order of elements in the chain T of blocks,
4304 and return the new head of the chain (old last element).
4305 Also do the same on subblocks and reverse the order of elements
4306 in BLOCK_FRAGMENT_CHAIN as well. */
4307
4308 static tree
4309 blocks_nreverse_all (tree t)
4310 {
4311 tree prev = 0, block, next;
4312 for (block = t; block; block = next)
4313 {
4314 next = BLOCK_CHAIN (block);
4315 BLOCK_CHAIN (block) = prev;
4316 if (BLOCK_FRAGMENT_CHAIN (block)
4317 && BLOCK_FRAGMENT_ORIGIN (block) == NULL_TREE)
4318 {
4319 BLOCK_FRAGMENT_CHAIN (block)
4320 = block_fragments_nreverse (BLOCK_FRAGMENT_CHAIN (block));
4321 if (!BLOCK_SAME_RANGE (BLOCK_FRAGMENT_CHAIN (block)))
4322 BLOCK_SAME_RANGE (block) = 0;
4323 }
4324 BLOCK_SUBBLOCKS (block) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block));
4325 prev = block;
4326 }
4327 return prev;
4328 }
4329
4330
4331 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
4332 and create duplicate blocks. */
4333 /* ??? Need an option to either create block fragments or to create
4334 abstract origin duplicates of a source block. It really depends
4335 on what optimization has been performed. */
4336
4337 void
4338 reorder_blocks (void)
4339 {
4340 tree block = DECL_INITIAL (current_function_decl);
4341
4342 if (block == NULL_TREE)
4343 return;
4344
4345 auto_vec<tree, 10> block_stack;
4346
4347 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
4348 clear_block_marks (block);
4349
4350 /* Prune the old trees away, so that they don't get in the way. */
4351 BLOCK_SUBBLOCKS (block) = NULL_TREE;
4352 BLOCK_CHAIN (block) = NULL_TREE;
4353
4354 /* Recreate the block tree from the note nesting. */
4355 reorder_blocks_1 (get_insns (), block, &block_stack);
4356 BLOCK_SUBBLOCKS (block) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block));
4357 }
4358
4359 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
4360
4361 void
4362 clear_block_marks (tree block)
4363 {
4364 while (block)
4365 {
4366 TREE_ASM_WRITTEN (block) = 0;
4367 clear_block_marks (BLOCK_SUBBLOCKS (block));
4368 block = BLOCK_CHAIN (block);
4369 }
4370 }
4371
4372 static void
4373 reorder_blocks_1 (rtx_insn *insns, tree current_block,
4374 vec<tree> *p_block_stack)
4375 {
4376 rtx_insn *insn;
4377 tree prev_beg = NULL_TREE, prev_end = NULL_TREE;
4378
4379 for (insn = insns; insn; insn = NEXT_INSN (insn))
4380 {
4381 if (NOTE_P (insn))
4382 {
4383 if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_BEG)
4384 {
4385 tree block = NOTE_BLOCK (insn);
4386 tree origin;
4387
4388 gcc_assert (BLOCK_FRAGMENT_ORIGIN (block) == NULL_TREE);
4389 origin = block;
4390
4391 if (prev_end)
4392 BLOCK_SAME_RANGE (prev_end) = 0;
4393 prev_end = NULL_TREE;
4394
4395 /* If we have seen this block before, that means it now
4396 spans multiple address regions. Create a new fragment. */
4397 if (TREE_ASM_WRITTEN (block))
4398 {
4399 tree new_block = copy_node (block);
4400
4401 BLOCK_SAME_RANGE (new_block) = 0;
4402 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
4403 BLOCK_FRAGMENT_CHAIN (new_block)
4404 = BLOCK_FRAGMENT_CHAIN (origin);
4405 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
4406
4407 NOTE_BLOCK (insn) = new_block;
4408 block = new_block;
4409 }
4410
4411 if (prev_beg == current_block && prev_beg)
4412 BLOCK_SAME_RANGE (block) = 1;
4413
4414 prev_beg = origin;
4415
4416 BLOCK_SUBBLOCKS (block) = 0;
4417 TREE_ASM_WRITTEN (block) = 1;
4418 /* When there's only one block for the entire function,
4419 current_block == block and we mustn't do this, it
4420 will cause infinite recursion. */
4421 if (block != current_block)
4422 {
4423 tree super;
4424 if (block != origin)
4425 gcc_assert (BLOCK_SUPERCONTEXT (origin) == current_block
4426 || BLOCK_FRAGMENT_ORIGIN (BLOCK_SUPERCONTEXT
4427 (origin))
4428 == current_block);
4429 if (p_block_stack->is_empty ())
4430 super = current_block;
4431 else
4432 {
4433 super = p_block_stack->last ();
4434 gcc_assert (super == current_block
4435 || BLOCK_FRAGMENT_ORIGIN (super)
4436 == current_block);
4437 }
4438 BLOCK_SUPERCONTEXT (block) = super;
4439 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
4440 BLOCK_SUBBLOCKS (current_block) = block;
4441 current_block = origin;
4442 }
4443 p_block_stack->safe_push (block);
4444 }
4445 else if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_END)
4446 {
4447 NOTE_BLOCK (insn) = p_block_stack->pop ();
4448 current_block = BLOCK_SUPERCONTEXT (current_block);
4449 if (BLOCK_FRAGMENT_ORIGIN (current_block))
4450 current_block = BLOCK_FRAGMENT_ORIGIN (current_block);
4451 prev_beg = NULL_TREE;
4452 prev_end = BLOCK_SAME_RANGE (NOTE_BLOCK (insn))
4453 ? NOTE_BLOCK (insn) : NULL_TREE;
4454 }
4455 }
4456 else
4457 {
4458 prev_beg = NULL_TREE;
4459 if (prev_end)
4460 BLOCK_SAME_RANGE (prev_end) = 0;
4461 prev_end = NULL_TREE;
4462 }
4463 }
4464 }
4465
4466 /* Reverse the order of elements in the chain T of blocks,
4467 and return the new head of the chain (old last element). */
4468
4469 tree
4470 blocks_nreverse (tree t)
4471 {
4472 tree prev = 0, block, next;
4473 for (block = t; block; block = next)
4474 {
4475 next = BLOCK_CHAIN (block);
4476 BLOCK_CHAIN (block) = prev;
4477 prev = block;
4478 }
4479 return prev;
4480 }
4481
4482 /* Concatenate two chains of blocks (chained through BLOCK_CHAIN)
4483 by modifying the last node in chain 1 to point to chain 2. */
4484
4485 tree
4486 block_chainon (tree op1, tree op2)
4487 {
4488 tree t1;
4489
4490 if (!op1)
4491 return op2;
4492 if (!op2)
4493 return op1;
4494
4495 for (t1 = op1; BLOCK_CHAIN (t1); t1 = BLOCK_CHAIN (t1))
4496 continue;
4497 BLOCK_CHAIN (t1) = op2;
4498
4499 #ifdef ENABLE_TREE_CHECKING
4500 {
4501 tree t2;
4502 for (t2 = op2; t2; t2 = BLOCK_CHAIN (t2))
4503 gcc_assert (t2 != t1);
4504 }
4505 #endif
4506
4507 return op1;
4508 }
4509
4510 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
4511 non-NULL, list them all into VECTOR, in a depth-first preorder
4512 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
4513 blocks. */
4514
4515 static int
4516 all_blocks (tree block, tree *vector)
4517 {
4518 int n_blocks = 0;
4519
4520 while (block)
4521 {
4522 TREE_ASM_WRITTEN (block) = 0;
4523
4524 /* Record this block. */
4525 if (vector)
4526 vector[n_blocks] = block;
4527
4528 ++n_blocks;
4529
4530 /* Record the subblocks, and their subblocks... */
4531 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
4532 vector ? vector + n_blocks : 0);
4533 block = BLOCK_CHAIN (block);
4534 }
4535
4536 return n_blocks;
4537 }
4538
4539 /* Return a vector containing all the blocks rooted at BLOCK. The
4540 number of elements in the vector is stored in N_BLOCKS_P. The
4541 vector is dynamically allocated; it is the caller's responsibility
4542 to call `free' on the pointer returned. */
4543
4544 static tree *
4545 get_block_vector (tree block, int *n_blocks_p)
4546 {
4547 tree *block_vector;
4548
4549 *n_blocks_p = all_blocks (block, NULL);
4550 block_vector = XNEWVEC (tree, *n_blocks_p);
4551 all_blocks (block, block_vector);
4552
4553 return block_vector;
4554 }
4555
4556 static GTY(()) int next_block_index = 2;
4557
4558 /* Set BLOCK_NUMBER for all the blocks in FN. */
4559
4560 void
4561 number_blocks (tree fn)
4562 {
4563 int i;
4564 int n_blocks;
4565 tree *block_vector;
4566
4567 /* For XCOFF debugging output, we start numbering the blocks
4568 from 1 within each function, rather than keeping a running
4569 count. */
4570 #if defined (XCOFF_DEBUGGING_INFO)
4571 if (write_symbols == XCOFF_DEBUG)
4572 next_block_index = 1;
4573 #endif
4574
4575 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
4576
4577 /* The top-level BLOCK isn't numbered at all. */
4578 for (i = 1; i < n_blocks; ++i)
4579 /* We number the blocks from two. */
4580 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
4581
4582 free (block_vector);
4583
4584 return;
4585 }
4586
4587 /* If VAR is present in a subblock of BLOCK, return the subblock. */
4588
4589 DEBUG_FUNCTION tree
4590 debug_find_var_in_block_tree (tree var, tree block)
4591 {
4592 tree t;
4593
4594 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
4595 if (t == var)
4596 return block;
4597
4598 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
4599 {
4600 tree ret = debug_find_var_in_block_tree (var, t);
4601 if (ret)
4602 return ret;
4603 }
4604
4605 return NULL_TREE;
4606 }
4607 \f
4608 /* Keep track of whether we're in a dummy function context. If we are,
4609 we don't want to invoke the set_current_function hook, because we'll
4610 get into trouble if the hook calls target_reinit () recursively or
4611 when the initial initialization is not yet complete. */
4612
4613 static bool in_dummy_function;
4614
4615 /* Invoke the target hook when setting cfun. Update the optimization options
4616 if the function uses different options than the default. */
4617
4618 static void
4619 invoke_set_current_function_hook (tree fndecl)
4620 {
4621 if (!in_dummy_function)
4622 {
4623 tree opts = ((fndecl)
4624 ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (fndecl)
4625 : optimization_default_node);
4626
4627 if (!opts)
4628 opts = optimization_default_node;
4629
4630 /* Change optimization options if needed. */
4631 if (optimization_current_node != opts)
4632 {
4633 optimization_current_node = opts;
4634 cl_optimization_restore (&global_options, TREE_OPTIMIZATION (opts));
4635 }
4636
4637 targetm.set_current_function (fndecl);
4638 this_fn_optabs = this_target_optabs;
4639
4640 /* Initialize global alignment variables after op. */
4641 parse_alignment_opts ();
4642
4643 if (opts != optimization_default_node)
4644 {
4645 init_tree_optimization_optabs (opts);
4646 if (TREE_OPTIMIZATION_OPTABS (opts))
4647 this_fn_optabs = (struct target_optabs *)
4648 TREE_OPTIMIZATION_OPTABS (opts);
4649 }
4650 }
4651 }
4652
4653 /* cfun should never be set directly; use this function. */
4654
4655 void
4656 set_cfun (struct function *new_cfun, bool force)
4657 {
4658 if (cfun != new_cfun || force)
4659 {
4660 cfun = new_cfun;
4661 invoke_set_current_function_hook (new_cfun ? new_cfun->decl : NULL_TREE);
4662 redirect_edge_var_map_empty ();
4663 }
4664 }
4665
4666 /* Initialized with NOGC, making this poisonous to the garbage collector. */
4667
4668 static vec<function *> cfun_stack;
4669
4670 /* Push the current cfun onto the stack, and set cfun to new_cfun. Also set
4671 current_function_decl accordingly. */
4672
4673 void
4674 push_cfun (struct function *new_cfun)
4675 {
4676 gcc_assert ((!cfun && !current_function_decl)
4677 || (cfun && current_function_decl == cfun->decl));
4678 cfun_stack.safe_push (cfun);
4679 current_function_decl = new_cfun ? new_cfun->decl : NULL_TREE;
4680 set_cfun (new_cfun);
4681 }
4682
4683 /* Pop cfun from the stack. Also set current_function_decl accordingly. */
4684
4685 void
4686 pop_cfun (void)
4687 {
4688 struct function *new_cfun = cfun_stack.pop ();
4689 /* When in_dummy_function, we do have a cfun but current_function_decl is
4690 NULL. We also allow pushing NULL cfun and subsequently changing
4691 current_function_decl to something else and have both restored by
4692 pop_cfun. */
4693 gcc_checking_assert (in_dummy_function
4694 || !cfun
4695 || current_function_decl == cfun->decl);
4696 set_cfun (new_cfun);
4697 current_function_decl = new_cfun ? new_cfun->decl : NULL_TREE;
4698 }
4699
4700 /* Return value of funcdef and increase it. */
4701 int
4702 get_next_funcdef_no (void)
4703 {
4704 return funcdef_no++;
4705 }
4706
4707 /* Return value of funcdef. */
4708 int
4709 get_last_funcdef_no (void)
4710 {
4711 return funcdef_no;
4712 }
4713
4714 /* Allocate a function structure for FNDECL and set its contents
4715 to the defaults. Set cfun to the newly-allocated object.
4716 Some of the helper functions invoked during initialization assume
4717 that cfun has already been set. Therefore, assign the new object
4718 directly into cfun and invoke the back end hook explicitly at the
4719 very end, rather than initializing a temporary and calling set_cfun
4720 on it.
4721
4722 ABSTRACT_P is true if this is a function that will never be seen by
4723 the middle-end. Such functions are front-end concepts (like C++
4724 function templates) that do not correspond directly to functions
4725 placed in object files. */
4726
4727 void
4728 allocate_struct_function (tree fndecl, bool abstract_p)
4729 {
4730 tree fntype = fndecl ? TREE_TYPE (fndecl) : NULL_TREE;
4731
4732 cfun = ggc_cleared_alloc<function> ();
4733
4734 init_eh_for_function ();
4735
4736 if (init_machine_status)
4737 cfun->machine = (*init_machine_status) ();
4738
4739 #ifdef OVERRIDE_ABI_FORMAT
4740 OVERRIDE_ABI_FORMAT (fndecl);
4741 #endif
4742
4743 if (fndecl != NULL_TREE)
4744 {
4745 DECL_STRUCT_FUNCTION (fndecl) = cfun;
4746 cfun->decl = fndecl;
4747 current_function_funcdef_no = get_next_funcdef_no ();
4748 }
4749
4750 invoke_set_current_function_hook (fndecl);
4751
4752 if (fndecl != NULL_TREE)
4753 {
4754 tree result = DECL_RESULT (fndecl);
4755
4756 if (!abstract_p)
4757 {
4758 /* Now that we have activated any function-specific attributes
4759 that might affect layout, particularly vector modes, relayout
4760 each of the parameters and the result. */
4761 relayout_decl (result);
4762 for (tree parm = DECL_ARGUMENTS (fndecl); parm;
4763 parm = DECL_CHAIN (parm))
4764 relayout_decl (parm);
4765
4766 /* Similarly relayout the function decl. */
4767 targetm.target_option.relayout_function (fndecl);
4768 }
4769
4770 if (!abstract_p && aggregate_value_p (result, fndecl))
4771 {
4772 #ifdef PCC_STATIC_STRUCT_RETURN
4773 cfun->returns_pcc_struct = 1;
4774 #endif
4775 cfun->returns_struct = 1;
4776 }
4777
4778 cfun->stdarg = stdarg_p (fntype);
4779
4780 /* Assume all registers in stdarg functions need to be saved. */
4781 cfun->va_list_gpr_size = VA_LIST_MAX_GPR_SIZE;
4782 cfun->va_list_fpr_size = VA_LIST_MAX_FPR_SIZE;
4783
4784 /* ??? This could be set on a per-function basis by the front-end
4785 but is this worth the hassle? */
4786 cfun->can_throw_non_call_exceptions = flag_non_call_exceptions;
4787 cfun->can_delete_dead_exceptions = flag_delete_dead_exceptions;
4788
4789 if (!profile_flag && !flag_instrument_function_entry_exit)
4790 DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl) = 1;
4791 }
4792
4793 /* Don't enable begin stmt markers if var-tracking at assignments is
4794 disabled. The markers make little sense without the variable
4795 binding annotations among them. */
4796 cfun->debug_nonbind_markers = lang_hooks.emits_begin_stmt
4797 && MAY_HAVE_DEBUG_MARKER_STMTS;
4798 }
4799
4800 /* This is like allocate_struct_function, but pushes a new cfun for FNDECL
4801 instead of just setting it. */
4802
4803 void
4804 push_struct_function (tree fndecl)
4805 {
4806 /* When in_dummy_function we might be in the middle of a pop_cfun and
4807 current_function_decl and cfun may not match. */
4808 gcc_assert (in_dummy_function
4809 || (!cfun && !current_function_decl)
4810 || (cfun && current_function_decl == cfun->decl));
4811 cfun_stack.safe_push (cfun);
4812 current_function_decl = fndecl;
4813 allocate_struct_function (fndecl, false);
4814 }
4815
4816 /* Reset crtl and other non-struct-function variables to defaults as
4817 appropriate for emitting rtl at the start of a function. */
4818
4819 static void
4820 prepare_function_start (void)
4821 {
4822 gcc_assert (!get_last_insn ());
4823 init_temp_slots ();
4824 init_emit ();
4825 init_varasm_status ();
4826 init_expr ();
4827 default_rtl_profile ();
4828
4829 if (flag_stack_usage_info)
4830 {
4831 cfun->su = ggc_cleared_alloc<stack_usage> ();
4832 cfun->su->static_stack_size = -1;
4833 }
4834
4835 cse_not_expected = ! optimize;
4836
4837 /* Caller save not needed yet. */
4838 caller_save_needed = 0;
4839
4840 /* We haven't done register allocation yet. */
4841 reg_renumber = 0;
4842
4843 /* Indicate that we have not instantiated virtual registers yet. */
4844 virtuals_instantiated = 0;
4845
4846 /* Indicate that we want CONCATs now. */
4847 generating_concat_p = 1;
4848
4849 /* Indicate we have no need of a frame pointer yet. */
4850 frame_pointer_needed = 0;
4851 }
4852
4853 void
4854 push_dummy_function (bool with_decl)
4855 {
4856 tree fn_decl, fn_type, fn_result_decl;
4857
4858 gcc_assert (!in_dummy_function);
4859 in_dummy_function = true;
4860
4861 if (with_decl)
4862 {
4863 fn_type = build_function_type_list (void_type_node, NULL_TREE);
4864 fn_decl = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL, NULL_TREE,
4865 fn_type);
4866 fn_result_decl = build_decl (UNKNOWN_LOCATION, RESULT_DECL,
4867 NULL_TREE, void_type_node);
4868 DECL_RESULT (fn_decl) = fn_result_decl;
4869 }
4870 else
4871 fn_decl = NULL_TREE;
4872
4873 push_struct_function (fn_decl);
4874 }
4875
4876 /* Initialize the rtl expansion mechanism so that we can do simple things
4877 like generate sequences. This is used to provide a context during global
4878 initialization of some passes. You must call expand_dummy_function_end
4879 to exit this context. */
4880
4881 void
4882 init_dummy_function_start (void)
4883 {
4884 push_dummy_function (false);
4885 prepare_function_start ();
4886 }
4887
4888 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
4889 and initialize static variables for generating RTL for the statements
4890 of the function. */
4891
4892 void
4893 init_function_start (tree subr)
4894 {
4895 /* Initialize backend, if needed. */
4896 initialize_rtl ();
4897
4898 prepare_function_start ();
4899 decide_function_section (subr);
4900
4901 /* Warn if this value is an aggregate type,
4902 regardless of which calling convention we are using for it. */
4903 if (AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
4904 warning (OPT_Waggregate_return, "function returns an aggregate");
4905 }
4906
4907 /* Expand code to verify the stack_protect_guard. This is invoked at
4908 the end of a function to be protected. */
4909
4910 void
4911 stack_protect_epilogue (void)
4912 {
4913 tree guard_decl = crtl->stack_protect_guard_decl;
4914 rtx_code_label *label = gen_label_rtx ();
4915 rtx x, y;
4916 rtx_insn *seq = NULL;
4917
4918 x = expand_normal (crtl->stack_protect_guard);
4919
4920 if (targetm.have_stack_protect_combined_test () && guard_decl)
4921 {
4922 gcc_assert (DECL_P (guard_decl));
4923 y = DECL_RTL (guard_decl);
4924 /* Allow the target to compute address of Y and compare it with X without
4925 leaking Y into a register. This combined address + compare pattern
4926 allows the target to prevent spilling of any intermediate results by
4927 splitting it after register allocator. */
4928 seq = targetm.gen_stack_protect_combined_test (x, y, label);
4929 }
4930 else
4931 {
4932 if (guard_decl)
4933 y = expand_normal (guard_decl);
4934 else
4935 y = const0_rtx;
4936
4937 /* Allow the target to compare Y with X without leaking either into
4938 a register. */
4939 if (targetm.have_stack_protect_test ())
4940 seq = targetm.gen_stack_protect_test (x, y, label);
4941 }
4942
4943 if (seq)
4944 emit_insn (seq);
4945 else
4946 emit_cmp_and_jump_insns (x, y, EQ, NULL_RTX, ptr_mode, 1, label);
4947
4948 /* The noreturn predictor has been moved to the tree level. The rtl-level
4949 predictors estimate this branch about 20%, which isn't enough to get
4950 things moved out of line. Since this is the only extant case of adding
4951 a noreturn function at the rtl level, it doesn't seem worth doing ought
4952 except adding the prediction by hand. */
4953 rtx_insn *tmp = get_last_insn ();
4954 if (JUMP_P (tmp))
4955 predict_insn_def (tmp, PRED_NORETURN, TAKEN);
4956
4957 expand_call (targetm.stack_protect_fail (), NULL_RTX, /*ignore=*/true);
4958 free_temp_slots ();
4959 emit_label (label);
4960 }
4961 \f
4962 /* Start the RTL for a new function, and set variables used for
4963 emitting RTL.
4964 SUBR is the FUNCTION_DECL node.
4965 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
4966 the function's parameters, which must be run at any return statement. */
4967
4968 void
4969 expand_function_start (tree subr)
4970 {
4971 /* Make sure volatile mem refs aren't considered
4972 valid operands of arithmetic insns. */
4973 init_recog_no_volatile ();
4974
4975 crtl->profile
4976 = (profile_flag
4977 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
4978
4979 crtl->limit_stack
4980 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
4981
4982 /* Make the label for return statements to jump to. Do not special
4983 case machines with special return instructions -- they will be
4984 handled later during jump, ifcvt, or epilogue creation. */
4985 return_label = gen_label_rtx ();
4986
4987 /* Initialize rtx used to return the value. */
4988 /* Do this before assign_parms so that we copy the struct value address
4989 before any library calls that assign parms might generate. */
4990
4991 /* Decide whether to return the value in memory or in a register. */
4992 tree res = DECL_RESULT (subr);
4993 if (aggregate_value_p (res, subr))
4994 {
4995 /* Returning something that won't go in a register. */
4996 rtx value_address = 0;
4997
4998 #ifdef PCC_STATIC_STRUCT_RETURN
4999 if (cfun->returns_pcc_struct)
5000 {
5001 int size = int_size_in_bytes (TREE_TYPE (res));
5002 value_address = assemble_static_space (size);
5003 }
5004 else
5005 #endif
5006 {
5007 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 2);
5008 /* Expect to be passed the address of a place to store the value.
5009 If it is passed as an argument, assign_parms will take care of
5010 it. */
5011 if (sv)
5012 {
5013 value_address = gen_reg_rtx (Pmode);
5014 emit_move_insn (value_address, sv);
5015 }
5016 }
5017 if (value_address)
5018 {
5019 rtx x = value_address;
5020 if (!DECL_BY_REFERENCE (res))
5021 {
5022 x = gen_rtx_MEM (DECL_MODE (res), x);
5023 set_mem_attributes (x, res, 1);
5024 }
5025 set_parm_rtl (res, x);
5026 }
5027 }
5028 else if (DECL_MODE (res) == VOIDmode)
5029 /* If return mode is void, this decl rtl should not be used. */
5030 set_parm_rtl (res, NULL_RTX);
5031 else
5032 {
5033 /* Compute the return values into a pseudo reg, which we will copy
5034 into the true return register after the cleanups are done. */
5035 tree return_type = TREE_TYPE (res);
5036
5037 /* If we may coalesce this result, make sure it has the expected mode
5038 in case it was promoted. But we need not bother about BLKmode. */
5039 machine_mode promoted_mode
5040 = flag_tree_coalesce_vars && is_gimple_reg (res)
5041 ? promote_ssa_mode (ssa_default_def (cfun, res), NULL)
5042 : BLKmode;
5043
5044 if (promoted_mode != BLKmode)
5045 set_parm_rtl (res, gen_reg_rtx (promoted_mode));
5046 else if (TYPE_MODE (return_type) != BLKmode
5047 && targetm.calls.return_in_msb (return_type))
5048 /* expand_function_end will insert the appropriate padding in
5049 this case. Use the return value's natural (unpadded) mode
5050 within the function proper. */
5051 set_parm_rtl (res, gen_reg_rtx (TYPE_MODE (return_type)));
5052 else
5053 {
5054 /* In order to figure out what mode to use for the pseudo, we
5055 figure out what the mode of the eventual return register will
5056 actually be, and use that. */
5057 rtx hard_reg = hard_function_value (return_type, subr, 0, 1);
5058
5059 /* Structures that are returned in registers are not
5060 aggregate_value_p, so we may see a PARALLEL or a REG. */
5061 if (REG_P (hard_reg))
5062 set_parm_rtl (res, gen_reg_rtx (GET_MODE (hard_reg)));
5063 else
5064 {
5065 gcc_assert (GET_CODE (hard_reg) == PARALLEL);
5066 set_parm_rtl (res, gen_group_rtx (hard_reg));
5067 }
5068 }
5069
5070 /* Set DECL_REGISTER flag so that expand_function_end will copy the
5071 result to the real return register(s). */
5072 DECL_REGISTER (res) = 1;
5073 }
5074
5075 /* Initialize rtx for parameters and local variables.
5076 In some cases this requires emitting insns. */
5077 assign_parms (subr);
5078
5079 /* If function gets a static chain arg, store it. */
5080 if (cfun->static_chain_decl)
5081 {
5082 tree parm = cfun->static_chain_decl;
5083 rtx local, chain;
5084 rtx_insn *insn;
5085 int unsignedp;
5086
5087 local = gen_reg_rtx (promote_decl_mode (parm, &unsignedp));
5088 chain = targetm.calls.static_chain (current_function_decl, true);
5089
5090 set_decl_incoming_rtl (parm, chain, false);
5091 set_parm_rtl (parm, local);
5092 mark_reg_pointer (local, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
5093
5094 if (GET_MODE (local) != GET_MODE (chain))
5095 {
5096 convert_move (local, chain, unsignedp);
5097 insn = get_last_insn ();
5098 }
5099 else
5100 insn = emit_move_insn (local, chain);
5101
5102 /* Mark the register as eliminable, similar to parameters. */
5103 if (MEM_P (chain)
5104 && reg_mentioned_p (arg_pointer_rtx, XEXP (chain, 0)))
5105 set_dst_reg_note (insn, REG_EQUIV, chain, local);
5106
5107 /* If we aren't optimizing, save the static chain onto the stack. */
5108 if (!optimize)
5109 {
5110 tree saved_static_chain_decl
5111 = build_decl (DECL_SOURCE_LOCATION (parm), VAR_DECL,
5112 DECL_NAME (parm), TREE_TYPE (parm));
5113 rtx saved_static_chain_rtx
5114 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
5115 SET_DECL_RTL (saved_static_chain_decl, saved_static_chain_rtx);
5116 emit_move_insn (saved_static_chain_rtx, chain);
5117 SET_DECL_VALUE_EXPR (parm, saved_static_chain_decl);
5118 DECL_HAS_VALUE_EXPR_P (parm) = 1;
5119 }
5120 }
5121
5122 /* The following was moved from init_function_start.
5123 The move was supposed to make sdb output more accurate. */
5124 /* Indicate the beginning of the function body,
5125 as opposed to parm setup. */
5126 emit_note (NOTE_INSN_FUNCTION_BEG);
5127
5128 gcc_assert (NOTE_P (get_last_insn ()));
5129
5130 parm_birth_insn = get_last_insn ();
5131
5132 /* If the function receives a non-local goto, then store the
5133 bits we need to restore the frame pointer. */
5134 if (cfun->nonlocal_goto_save_area)
5135 {
5136 tree t_save;
5137 rtx r_save;
5138
5139 tree var = TREE_OPERAND (cfun->nonlocal_goto_save_area, 0);
5140 gcc_assert (DECL_RTL_SET_P (var));
5141
5142 t_save = build4 (ARRAY_REF,
5143 TREE_TYPE (TREE_TYPE (cfun->nonlocal_goto_save_area)),
5144 cfun->nonlocal_goto_save_area,
5145 integer_zero_node, NULL_TREE, NULL_TREE);
5146 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
5147 gcc_assert (GET_MODE (r_save) == Pmode);
5148
5149 emit_move_insn (r_save, hard_frame_pointer_rtx);
5150 update_nonlocal_goto_save_area ();
5151 }
5152
5153 if (crtl->profile)
5154 {
5155 #ifdef PROFILE_HOOK
5156 PROFILE_HOOK (current_function_funcdef_no);
5157 #endif
5158 }
5159
5160 /* If we are doing generic stack checking, the probe should go here. */
5161 if (flag_stack_check == GENERIC_STACK_CHECK)
5162 stack_check_probe_note = emit_note (NOTE_INSN_DELETED);
5163 }
5164 \f
5165 void
5166 pop_dummy_function (void)
5167 {
5168 pop_cfun ();
5169 in_dummy_function = false;
5170 }
5171
5172 /* Undo the effects of init_dummy_function_start. */
5173 void
5174 expand_dummy_function_end (void)
5175 {
5176 gcc_assert (in_dummy_function);
5177
5178 /* End any sequences that failed to be closed due to syntax errors. */
5179 while (in_sequence_p ())
5180 end_sequence ();
5181
5182 /* Outside function body, can't compute type's actual size
5183 until next function's body starts. */
5184
5185 free_after_parsing (cfun);
5186 free_after_compilation (cfun);
5187 pop_dummy_function ();
5188 }
5189
5190 /* Helper for diddle_return_value. */
5191
5192 void
5193 diddle_return_value_1 (void (*doit) (rtx, void *), void *arg, rtx outgoing)
5194 {
5195 if (! outgoing)
5196 return;
5197
5198 if (REG_P (outgoing))
5199 (*doit) (outgoing, arg);
5200 else if (GET_CODE (outgoing) == PARALLEL)
5201 {
5202 int i;
5203
5204 for (i = 0; i < XVECLEN (outgoing, 0); i++)
5205 {
5206 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
5207
5208 if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
5209 (*doit) (x, arg);
5210 }
5211 }
5212 }
5213
5214 /* Call DOIT for each hard register used as a return value from
5215 the current function. */
5216
5217 void
5218 diddle_return_value (void (*doit) (rtx, void *), void *arg)
5219 {
5220 diddle_return_value_1 (doit, arg, crtl->return_rtx);
5221 }
5222
5223 static void
5224 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
5225 {
5226 emit_clobber (reg);
5227 }
5228
5229 void
5230 clobber_return_register (void)
5231 {
5232 diddle_return_value (do_clobber_return_reg, NULL);
5233
5234 /* In case we do use pseudo to return value, clobber it too. */
5235 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
5236 {
5237 tree decl_result = DECL_RESULT (current_function_decl);
5238 rtx decl_rtl = DECL_RTL (decl_result);
5239 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
5240 {
5241 do_clobber_return_reg (decl_rtl, NULL);
5242 }
5243 }
5244 }
5245
5246 static void
5247 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
5248 {
5249 emit_use (reg);
5250 }
5251
5252 static void
5253 use_return_register (void)
5254 {
5255 diddle_return_value (do_use_return_reg, NULL);
5256 }
5257
5258 /* Generate RTL for the end of the current function. */
5259
5260 void
5261 expand_function_end (void)
5262 {
5263 /* If arg_pointer_save_area was referenced only from a nested
5264 function, we will not have initialized it yet. Do that now. */
5265 if (arg_pointer_save_area && ! crtl->arg_pointer_save_area_init)
5266 get_arg_pointer_save_area ();
5267
5268 /* If we are doing generic stack checking and this function makes calls,
5269 do a stack probe at the start of the function to ensure we have enough
5270 space for another stack frame. */
5271 if (flag_stack_check == GENERIC_STACK_CHECK)
5272 {
5273 rtx_insn *insn, *seq;
5274
5275 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
5276 if (CALL_P (insn))
5277 {
5278 rtx max_frame_size = GEN_INT (STACK_CHECK_MAX_FRAME_SIZE);
5279 start_sequence ();
5280 if (STACK_CHECK_MOVING_SP)
5281 anti_adjust_stack_and_probe (max_frame_size, true);
5282 else
5283 probe_stack_range (STACK_OLD_CHECK_PROTECT, max_frame_size);
5284 seq = get_insns ();
5285 end_sequence ();
5286 set_insn_locations (seq, prologue_location);
5287 emit_insn_before (seq, stack_check_probe_note);
5288 break;
5289 }
5290 }
5291
5292 /* End any sequences that failed to be closed due to syntax errors. */
5293 while (in_sequence_p ())
5294 end_sequence ();
5295
5296 clear_pending_stack_adjust ();
5297 do_pending_stack_adjust ();
5298
5299 /* Output a linenumber for the end of the function.
5300 SDB depended on this. */
5301 set_curr_insn_location (input_location);
5302
5303 /* Before the return label (if any), clobber the return
5304 registers so that they are not propagated live to the rest of
5305 the function. This can only happen with functions that drop
5306 through; if there had been a return statement, there would
5307 have either been a return rtx, or a jump to the return label.
5308
5309 We delay actual code generation after the current_function_value_rtx
5310 is computed. */
5311 rtx_insn *clobber_after = get_last_insn ();
5312
5313 /* Output the label for the actual return from the function. */
5314 emit_label (return_label);
5315
5316 if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ)
5317 {
5318 /* Let except.c know where it should emit the call to unregister
5319 the function context for sjlj exceptions. */
5320 if (flag_exceptions)
5321 sjlj_emit_function_exit_after (get_last_insn ());
5322 }
5323
5324 /* If this is an implementation of throw, do what's necessary to
5325 communicate between __builtin_eh_return and the epilogue. */
5326 expand_eh_return ();
5327
5328 /* If stack protection is enabled for this function, check the guard. */
5329 if (crtl->stack_protect_guard
5330 && targetm.stack_protect_runtime_enabled_p ()
5331 && naked_return_label == NULL_RTX)
5332 stack_protect_epilogue ();
5333
5334 /* If scalar return value was computed in a pseudo-reg, or was a named
5335 return value that got dumped to the stack, copy that to the hard
5336 return register. */
5337 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
5338 {
5339 tree decl_result = DECL_RESULT (current_function_decl);
5340 rtx decl_rtl = DECL_RTL (decl_result);
5341
5342 if (REG_P (decl_rtl)
5343 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
5344 : DECL_REGISTER (decl_result))
5345 {
5346 rtx real_decl_rtl = crtl->return_rtx;
5347 complex_mode cmode;
5348
5349 /* This should be set in assign_parms. */
5350 gcc_assert (REG_FUNCTION_VALUE_P (real_decl_rtl));
5351
5352 /* If this is a BLKmode structure being returned in registers,
5353 then use the mode computed in expand_return. Note that if
5354 decl_rtl is memory, then its mode may have been changed,
5355 but that crtl->return_rtx has not. */
5356 if (GET_MODE (real_decl_rtl) == BLKmode)
5357 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
5358
5359 /* If a non-BLKmode return value should be padded at the least
5360 significant end of the register, shift it left by the appropriate
5361 amount. BLKmode results are handled using the group load/store
5362 machinery. */
5363 if (TYPE_MODE (TREE_TYPE (decl_result)) != BLKmode
5364 && REG_P (real_decl_rtl)
5365 && targetm.calls.return_in_msb (TREE_TYPE (decl_result)))
5366 {
5367 emit_move_insn (gen_rtx_REG (GET_MODE (decl_rtl),
5368 REGNO (real_decl_rtl)),
5369 decl_rtl);
5370 shift_return_value (GET_MODE (decl_rtl), true, real_decl_rtl);
5371 }
5372 else if (GET_CODE (real_decl_rtl) == PARALLEL)
5373 {
5374 /* If expand_function_start has created a PARALLEL for decl_rtl,
5375 move the result to the real return registers. Otherwise, do
5376 a group load from decl_rtl for a named return. */
5377 if (GET_CODE (decl_rtl) == PARALLEL)
5378 emit_group_move (real_decl_rtl, decl_rtl);
5379 else
5380 emit_group_load (real_decl_rtl, decl_rtl,
5381 TREE_TYPE (decl_result),
5382 int_size_in_bytes (TREE_TYPE (decl_result)));
5383 }
5384 /* In the case of complex integer modes smaller than a word, we'll
5385 need to generate some non-trivial bitfield insertions. Do that
5386 on a pseudo and not the hard register. */
5387 else if (GET_CODE (decl_rtl) == CONCAT
5388 && is_complex_int_mode (GET_MODE (decl_rtl), &cmode)
5389 && GET_MODE_BITSIZE (cmode) <= BITS_PER_WORD)
5390 {
5391 int old_generating_concat_p;
5392 rtx tmp;
5393
5394 old_generating_concat_p = generating_concat_p;
5395 generating_concat_p = 0;
5396 tmp = gen_reg_rtx (GET_MODE (decl_rtl));
5397 generating_concat_p = old_generating_concat_p;
5398
5399 emit_move_insn (tmp, decl_rtl);
5400 emit_move_insn (real_decl_rtl, tmp);
5401 }
5402 /* If a named return value dumped decl_return to memory, then
5403 we may need to re-do the PROMOTE_MODE signed/unsigned
5404 extension. */
5405 else if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
5406 {
5407 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
5408 promote_function_mode (TREE_TYPE (decl_result),
5409 GET_MODE (decl_rtl), &unsignedp,
5410 TREE_TYPE (current_function_decl), 1);
5411
5412 convert_move (real_decl_rtl, decl_rtl, unsignedp);
5413 }
5414 else
5415 emit_move_insn (real_decl_rtl, decl_rtl);
5416 }
5417 }
5418
5419 /* If returning a structure, arrange to return the address of the value
5420 in a place where debuggers expect to find it.
5421
5422 If returning a structure PCC style,
5423 the caller also depends on this value.
5424 And cfun->returns_pcc_struct is not necessarily set. */
5425 if ((cfun->returns_struct || cfun->returns_pcc_struct)
5426 && !targetm.calls.omit_struct_return_reg)
5427 {
5428 rtx value_address = DECL_RTL (DECL_RESULT (current_function_decl));
5429 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
5430 rtx outgoing;
5431
5432 if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
5433 type = TREE_TYPE (type);
5434 else
5435 value_address = XEXP (value_address, 0);
5436
5437 outgoing = targetm.calls.function_value (build_pointer_type (type),
5438 current_function_decl, true);
5439
5440 /* Mark this as a function return value so integrate will delete the
5441 assignment and USE below when inlining this function. */
5442 REG_FUNCTION_VALUE_P (outgoing) = 1;
5443
5444 /* The address may be ptr_mode and OUTGOING may be Pmode. */
5445 scalar_int_mode mode = as_a <scalar_int_mode> (GET_MODE (outgoing));
5446 value_address = convert_memory_address (mode, value_address);
5447
5448 emit_move_insn (outgoing, value_address);
5449
5450 /* Show return register used to hold result (in this case the address
5451 of the result. */
5452 crtl->return_rtx = outgoing;
5453 }
5454
5455 /* Emit the actual code to clobber return register. Don't emit
5456 it if clobber_after is a barrier, then the previous basic block
5457 certainly doesn't fall thru into the exit block. */
5458 if (!BARRIER_P (clobber_after))
5459 {
5460 start_sequence ();
5461 clobber_return_register ();
5462 rtx_insn *seq = get_insns ();
5463 end_sequence ();
5464
5465 emit_insn_after (seq, clobber_after);
5466 }
5467
5468 /* Output the label for the naked return from the function. */
5469 if (naked_return_label)
5470 emit_label (naked_return_label);
5471
5472 /* @@@ This is a kludge. We want to ensure that instructions that
5473 may trap are not moved into the epilogue by scheduling, because
5474 we don't always emit unwind information for the epilogue. */
5475 if (cfun->can_throw_non_call_exceptions
5476 && targetm_common.except_unwind_info (&global_options) != UI_SJLJ)
5477 emit_insn (gen_blockage ());
5478
5479 /* If stack protection is enabled for this function, check the guard. */
5480 if (crtl->stack_protect_guard
5481 && targetm.stack_protect_runtime_enabled_p ()
5482 && naked_return_label)
5483 stack_protect_epilogue ();
5484
5485 /* If we had calls to alloca, and this machine needs
5486 an accurate stack pointer to exit the function,
5487 insert some code to save and restore the stack pointer. */
5488 if (! EXIT_IGNORE_STACK
5489 && cfun->calls_alloca)
5490 {
5491 rtx tem = 0;
5492
5493 start_sequence ();
5494 emit_stack_save (SAVE_FUNCTION, &tem);
5495 rtx_insn *seq = get_insns ();
5496 end_sequence ();
5497 emit_insn_before (seq, parm_birth_insn);
5498
5499 emit_stack_restore (SAVE_FUNCTION, tem);
5500 }
5501
5502 /* ??? This should no longer be necessary since stupid is no longer with
5503 us, but there are some parts of the compiler (eg reload_combine, and
5504 sh mach_dep_reorg) that still try and compute their own lifetime info
5505 instead of using the general framework. */
5506 use_return_register ();
5507 }
5508
5509 rtx
5510 get_arg_pointer_save_area (void)
5511 {
5512 rtx ret = arg_pointer_save_area;
5513
5514 if (! ret)
5515 {
5516 ret = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
5517 arg_pointer_save_area = ret;
5518 }
5519
5520 if (! crtl->arg_pointer_save_area_init)
5521 {
5522 /* Save the arg pointer at the beginning of the function. The
5523 generated stack slot may not be a valid memory address, so we
5524 have to check it and fix it if necessary. */
5525 start_sequence ();
5526 emit_move_insn (validize_mem (copy_rtx (ret)),
5527 crtl->args.internal_arg_pointer);
5528 rtx_insn *seq = get_insns ();
5529 end_sequence ();
5530
5531 push_topmost_sequence ();
5532 emit_insn_after (seq, entry_of_function ());
5533 pop_topmost_sequence ();
5534
5535 crtl->arg_pointer_save_area_init = true;
5536 }
5537
5538 return ret;
5539 }
5540 \f
5541
5542 /* If debugging dumps are requested, dump information about how the
5543 target handled -fstack-check=clash for the prologue.
5544
5545 PROBES describes what if any probes were emitted.
5546
5547 RESIDUALS indicates if the prologue had any residual allocation
5548 (i.e. total allocation was not a multiple of PROBE_INTERVAL). */
5549
5550 void
5551 dump_stack_clash_frame_info (enum stack_clash_probes probes, bool residuals)
5552 {
5553 if (!dump_file)
5554 return;
5555
5556 switch (probes)
5557 {
5558 case NO_PROBE_NO_FRAME:
5559 fprintf (dump_file,
5560 "Stack clash no probe no stack adjustment in prologue.\n");
5561 break;
5562 case NO_PROBE_SMALL_FRAME:
5563 fprintf (dump_file,
5564 "Stack clash no probe small stack adjustment in prologue.\n");
5565 break;
5566 case PROBE_INLINE:
5567 fprintf (dump_file, "Stack clash inline probes in prologue.\n");
5568 break;
5569 case PROBE_LOOP:
5570 fprintf (dump_file, "Stack clash probe loop in prologue.\n");
5571 break;
5572 }
5573
5574 if (residuals)
5575 fprintf (dump_file, "Stack clash residual allocation in prologue.\n");
5576 else
5577 fprintf (dump_file, "Stack clash no residual allocation in prologue.\n");
5578
5579 if (frame_pointer_needed)
5580 fprintf (dump_file, "Stack clash frame pointer needed.\n");
5581 else
5582 fprintf (dump_file, "Stack clash no frame pointer needed.\n");
5583
5584 if (TREE_THIS_VOLATILE (cfun->decl))
5585 fprintf (dump_file,
5586 "Stack clash noreturn prologue, assuming no implicit"
5587 " probes in caller.\n");
5588 else
5589 fprintf (dump_file,
5590 "Stack clash not noreturn prologue.\n");
5591 }
5592
5593 /* Add a list of INSNS to the hash HASHP, possibly allocating HASHP
5594 for the first time. */
5595
5596 static void
5597 record_insns (rtx_insn *insns, rtx end, hash_table<insn_cache_hasher> **hashp)
5598 {
5599 rtx_insn *tmp;
5600 hash_table<insn_cache_hasher> *hash = *hashp;
5601
5602 if (hash == NULL)
5603 *hashp = hash = hash_table<insn_cache_hasher>::create_ggc (17);
5604
5605 for (tmp = insns; tmp != end; tmp = NEXT_INSN (tmp))
5606 {
5607 rtx *slot = hash->find_slot (tmp, INSERT);
5608 gcc_assert (*slot == NULL);
5609 *slot = tmp;
5610 }
5611 }
5612
5613 /* INSN has been duplicated or replaced by as COPY, perhaps by duplicating a
5614 basic block, splitting or peepholes. If INSN is a prologue or epilogue
5615 insn, then record COPY as well. */
5616
5617 void
5618 maybe_copy_prologue_epilogue_insn (rtx insn, rtx copy)
5619 {
5620 hash_table<insn_cache_hasher> *hash;
5621 rtx *slot;
5622
5623 hash = epilogue_insn_hash;
5624 if (!hash || !hash->find (insn))
5625 {
5626 hash = prologue_insn_hash;
5627 if (!hash || !hash->find (insn))
5628 return;
5629 }
5630
5631 slot = hash->find_slot (copy, INSERT);
5632 gcc_assert (*slot == NULL);
5633 *slot = copy;
5634 }
5635
5636 /* Determine if any INSNs in HASH are, or are part of, INSN. Because
5637 we can be running after reorg, SEQUENCE rtl is possible. */
5638
5639 static bool
5640 contains (const rtx_insn *insn, hash_table<insn_cache_hasher> *hash)
5641 {
5642 if (hash == NULL)
5643 return false;
5644
5645 if (NONJUMP_INSN_P (insn) && GET_CODE (PATTERN (insn)) == SEQUENCE)
5646 {
5647 rtx_sequence *seq = as_a <rtx_sequence *> (PATTERN (insn));
5648 int i;
5649 for (i = seq->len () - 1; i >= 0; i--)
5650 if (hash->find (seq->element (i)))
5651 return true;
5652 return false;
5653 }
5654
5655 return hash->find (const_cast<rtx_insn *> (insn)) != NULL;
5656 }
5657
5658 int
5659 prologue_contains (const rtx_insn *insn)
5660 {
5661 return contains (insn, prologue_insn_hash);
5662 }
5663
5664 int
5665 epilogue_contains (const rtx_insn *insn)
5666 {
5667 return contains (insn, epilogue_insn_hash);
5668 }
5669
5670 int
5671 prologue_epilogue_contains (const rtx_insn *insn)
5672 {
5673 if (contains (insn, prologue_insn_hash))
5674 return 1;
5675 if (contains (insn, epilogue_insn_hash))
5676 return 1;
5677 return 0;
5678 }
5679
5680 void
5681 record_prologue_seq (rtx_insn *seq)
5682 {
5683 record_insns (seq, NULL, &prologue_insn_hash);
5684 }
5685
5686 void
5687 record_epilogue_seq (rtx_insn *seq)
5688 {
5689 record_insns (seq, NULL, &epilogue_insn_hash);
5690 }
5691
5692 /* Set JUMP_LABEL for a return insn. */
5693
5694 void
5695 set_return_jump_label (rtx_insn *returnjump)
5696 {
5697 rtx pat = PATTERN (returnjump);
5698 if (GET_CODE (pat) == PARALLEL)
5699 pat = XVECEXP (pat, 0, 0);
5700 if (ANY_RETURN_P (pat))
5701 JUMP_LABEL (returnjump) = pat;
5702 else
5703 JUMP_LABEL (returnjump) = ret_rtx;
5704 }
5705
5706 /* Return a sequence to be used as the split prologue for the current
5707 function, or NULL. */
5708
5709 static rtx_insn *
5710 make_split_prologue_seq (void)
5711 {
5712 if (!flag_split_stack
5713 || lookup_attribute ("no_split_stack", DECL_ATTRIBUTES (cfun->decl)))
5714 return NULL;
5715
5716 start_sequence ();
5717 emit_insn (targetm.gen_split_stack_prologue ());
5718 rtx_insn *seq = get_insns ();
5719 end_sequence ();
5720
5721 record_insns (seq, NULL, &prologue_insn_hash);
5722 set_insn_locations (seq, prologue_location);
5723
5724 return seq;
5725 }
5726
5727 /* Return a sequence to be used as the prologue for the current function,
5728 or NULL. */
5729
5730 static rtx_insn *
5731 make_prologue_seq (void)
5732 {
5733 if (!targetm.have_prologue ())
5734 return NULL;
5735
5736 start_sequence ();
5737 rtx_insn *seq = targetm.gen_prologue ();
5738 emit_insn (seq);
5739
5740 /* Insert an explicit USE for the frame pointer
5741 if the profiling is on and the frame pointer is required. */
5742 if (crtl->profile && frame_pointer_needed)
5743 emit_use (hard_frame_pointer_rtx);
5744
5745 /* Retain a map of the prologue insns. */
5746 record_insns (seq, NULL, &prologue_insn_hash);
5747 emit_note (NOTE_INSN_PROLOGUE_END);
5748
5749 /* Ensure that instructions are not moved into the prologue when
5750 profiling is on. The call to the profiling routine can be
5751 emitted within the live range of a call-clobbered register. */
5752 if (!targetm.profile_before_prologue () && crtl->profile)
5753 emit_insn (gen_blockage ());
5754
5755 seq = get_insns ();
5756 end_sequence ();
5757 set_insn_locations (seq, prologue_location);
5758
5759 return seq;
5760 }
5761
5762 /* Return a sequence to be used as the epilogue for the current function,
5763 or NULL. */
5764
5765 static rtx_insn *
5766 make_epilogue_seq (void)
5767 {
5768 if (!targetm.have_epilogue ())
5769 return NULL;
5770
5771 start_sequence ();
5772 emit_note (NOTE_INSN_EPILOGUE_BEG);
5773 rtx_insn *seq = targetm.gen_epilogue ();
5774 if (seq)
5775 emit_jump_insn (seq);
5776
5777 /* Retain a map of the epilogue insns. */
5778 record_insns (seq, NULL, &epilogue_insn_hash);
5779 set_insn_locations (seq, epilogue_location);
5780
5781 seq = get_insns ();
5782 rtx_insn *returnjump = get_last_insn ();
5783 end_sequence ();
5784
5785 if (JUMP_P (returnjump))
5786 set_return_jump_label (returnjump);
5787
5788 return seq;
5789 }
5790
5791
5792 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
5793 this into place with notes indicating where the prologue ends and where
5794 the epilogue begins. Update the basic block information when possible.
5795
5796 Notes on epilogue placement:
5797 There are several kinds of edges to the exit block:
5798 * a single fallthru edge from LAST_BB
5799 * possibly, edges from blocks containing sibcalls
5800 * possibly, fake edges from infinite loops
5801
5802 The epilogue is always emitted on the fallthru edge from the last basic
5803 block in the function, LAST_BB, into the exit block.
5804
5805 If LAST_BB is empty except for a label, it is the target of every
5806 other basic block in the function that ends in a return. If a
5807 target has a return or simple_return pattern (possibly with
5808 conditional variants), these basic blocks can be changed so that a
5809 return insn is emitted into them, and their target is adjusted to
5810 the real exit block.
5811
5812 Notes on shrink wrapping: We implement a fairly conservative
5813 version of shrink-wrapping rather than the textbook one. We only
5814 generate a single prologue and a single epilogue. This is
5815 sufficient to catch a number of interesting cases involving early
5816 exits.
5817
5818 First, we identify the blocks that require the prologue to occur before
5819 them. These are the ones that modify a call-saved register, or reference
5820 any of the stack or frame pointer registers. To simplify things, we then
5821 mark everything reachable from these blocks as also requiring a prologue.
5822 This takes care of loops automatically, and avoids the need to examine
5823 whether MEMs reference the frame, since it is sufficient to check for
5824 occurrences of the stack or frame pointer.
5825
5826 We then compute the set of blocks for which the need for a prologue
5827 is anticipatable (borrowing terminology from the shrink-wrapping
5828 description in Muchnick's book). These are the blocks which either
5829 require a prologue themselves, or those that have only successors
5830 where the prologue is anticipatable. The prologue needs to be
5831 inserted on all edges from BB1->BB2 where BB2 is in ANTIC and BB1
5832 is not. For the moment, we ensure that only one such edge exists.
5833
5834 The epilogue is placed as described above, but we make a
5835 distinction between inserting return and simple_return patterns
5836 when modifying other blocks that end in a return. Blocks that end
5837 in a sibcall omit the sibcall_epilogue if the block is not in
5838 ANTIC. */
5839
5840 void
5841 thread_prologue_and_epilogue_insns (void)
5842 {
5843 df_analyze ();
5844
5845 /* Can't deal with multiple successors of the entry block at the
5846 moment. Function should always have at least one entry
5847 point. */
5848 gcc_assert (single_succ_p (ENTRY_BLOCK_PTR_FOR_FN (cfun)));
5849
5850 edge entry_edge = single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun));
5851 edge orig_entry_edge = entry_edge;
5852
5853 rtx_insn *split_prologue_seq = make_split_prologue_seq ();
5854 rtx_insn *prologue_seq = make_prologue_seq ();
5855 rtx_insn *epilogue_seq = make_epilogue_seq ();
5856
5857 /* Try to perform a kind of shrink-wrapping, making sure the
5858 prologue/epilogue is emitted only around those parts of the
5859 function that require it. */
5860 try_shrink_wrapping (&entry_edge, prologue_seq);
5861
5862 /* If the target can handle splitting the prologue/epilogue into separate
5863 components, try to shrink-wrap these components separately. */
5864 try_shrink_wrapping_separate (entry_edge->dest);
5865
5866 /* If that did anything for any component we now need the generate the
5867 "main" prologue again. Because some targets require some of these
5868 to be called in a specific order (i386 requires the split prologue
5869 to be first, for example), we create all three sequences again here.
5870 If this does not work for some target, that target should not enable
5871 separate shrink-wrapping. */
5872 if (crtl->shrink_wrapped_separate)
5873 {
5874 split_prologue_seq = make_split_prologue_seq ();
5875 prologue_seq = make_prologue_seq ();
5876 epilogue_seq = make_epilogue_seq ();
5877 }
5878
5879 rtl_profile_for_bb (EXIT_BLOCK_PTR_FOR_FN (cfun));
5880
5881 /* A small fib -- epilogue is not yet completed, but we wish to re-use
5882 this marker for the splits of EH_RETURN patterns, and nothing else
5883 uses the flag in the meantime. */
5884 epilogue_completed = 1;
5885
5886 /* Find non-fallthru edges that end with EH_RETURN instructions. On
5887 some targets, these get split to a special version of the epilogue
5888 code. In order to be able to properly annotate these with unwind
5889 info, try to split them now. If we get a valid split, drop an
5890 EPILOGUE_BEG note and mark the insns as epilogue insns. */
5891 edge e;
5892 edge_iterator ei;
5893 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
5894 {
5895 rtx_insn *prev, *last, *trial;
5896
5897 if (e->flags & EDGE_FALLTHRU)
5898 continue;
5899 last = BB_END (e->src);
5900 if (!eh_returnjump_p (last))
5901 continue;
5902
5903 prev = PREV_INSN (last);
5904 trial = try_split (PATTERN (last), last, 1);
5905 if (trial == last)
5906 continue;
5907
5908 record_insns (NEXT_INSN (prev), NEXT_INSN (trial), &epilogue_insn_hash);
5909 emit_note_after (NOTE_INSN_EPILOGUE_BEG, prev);
5910 }
5911
5912 edge exit_fallthru_edge = find_fallthru_edge (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds);
5913
5914 if (exit_fallthru_edge)
5915 {
5916 if (epilogue_seq)
5917 {
5918 insert_insn_on_edge (epilogue_seq, exit_fallthru_edge);
5919 commit_edge_insertions ();
5920
5921 /* The epilogue insns we inserted may cause the exit edge to no longer
5922 be fallthru. */
5923 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
5924 {
5925 if (((e->flags & EDGE_FALLTHRU) != 0)
5926 && returnjump_p (BB_END (e->src)))
5927 e->flags &= ~EDGE_FALLTHRU;
5928 }
5929 }
5930 else if (next_active_insn (BB_END (exit_fallthru_edge->src)))
5931 {
5932 /* We have a fall-through edge to the exit block, the source is not
5933 at the end of the function, and there will be an assembler epilogue
5934 at the end of the function.
5935 We can't use force_nonfallthru here, because that would try to
5936 use return. Inserting a jump 'by hand' is extremely messy, so
5937 we take advantage of cfg_layout_finalize using
5938 fixup_fallthru_exit_predecessor. */
5939 cfg_layout_initialize (0);
5940 basic_block cur_bb;
5941 FOR_EACH_BB_FN (cur_bb, cfun)
5942 if (cur_bb->index >= NUM_FIXED_BLOCKS
5943 && cur_bb->next_bb->index >= NUM_FIXED_BLOCKS)
5944 cur_bb->aux = cur_bb->next_bb;
5945 cfg_layout_finalize ();
5946 }
5947 }
5948
5949 /* Insert the prologue. */
5950
5951 rtl_profile_for_bb (ENTRY_BLOCK_PTR_FOR_FN (cfun));
5952
5953 if (split_prologue_seq || prologue_seq)
5954 {
5955 rtx_insn *split_prologue_insn = split_prologue_seq;
5956 if (split_prologue_seq)
5957 {
5958 while (split_prologue_insn && !NONDEBUG_INSN_P (split_prologue_insn))
5959 split_prologue_insn = NEXT_INSN (split_prologue_insn);
5960 insert_insn_on_edge (split_prologue_seq, orig_entry_edge);
5961 }
5962
5963 rtx_insn *prologue_insn = prologue_seq;
5964 if (prologue_seq)
5965 {
5966 while (prologue_insn && !NONDEBUG_INSN_P (prologue_insn))
5967 prologue_insn = NEXT_INSN (prologue_insn);
5968 insert_insn_on_edge (prologue_seq, entry_edge);
5969 }
5970
5971 commit_edge_insertions ();
5972
5973 /* Look for basic blocks within the prologue insns. */
5974 if (split_prologue_insn
5975 && BLOCK_FOR_INSN (split_prologue_insn) == NULL)
5976 split_prologue_insn = NULL;
5977 if (prologue_insn
5978 && BLOCK_FOR_INSN (prologue_insn) == NULL)
5979 prologue_insn = NULL;
5980 if (split_prologue_insn || prologue_insn)
5981 {
5982 auto_sbitmap blocks (last_basic_block_for_fn (cfun));
5983 bitmap_clear (blocks);
5984 if (split_prologue_insn)
5985 bitmap_set_bit (blocks,
5986 BLOCK_FOR_INSN (split_prologue_insn)->index);
5987 if (prologue_insn)
5988 bitmap_set_bit (blocks, BLOCK_FOR_INSN (prologue_insn)->index);
5989 find_many_sub_basic_blocks (blocks);
5990 }
5991 }
5992
5993 default_rtl_profile ();
5994
5995 /* Emit sibling epilogues before any sibling call sites. */
5996 for (ei = ei_start (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds);
5997 (e = ei_safe_edge (ei));
5998 ei_next (&ei))
5999 {
6000 /* Skip those already handled, the ones that run without prologue. */
6001 if (e->flags & EDGE_IGNORE)
6002 {
6003 e->flags &= ~EDGE_IGNORE;
6004 continue;
6005 }
6006
6007 rtx_insn *insn = BB_END (e->src);
6008
6009 if (!(CALL_P (insn) && SIBLING_CALL_P (insn)))
6010 continue;
6011
6012 if (rtx_insn *ep_seq = targetm.gen_sibcall_epilogue ())
6013 {
6014 start_sequence ();
6015 emit_note (NOTE_INSN_EPILOGUE_BEG);
6016 emit_insn (ep_seq);
6017 rtx_insn *seq = get_insns ();
6018 end_sequence ();
6019
6020 /* Retain a map of the epilogue insns. Used in life analysis to
6021 avoid getting rid of sibcall epilogue insns. Do this before we
6022 actually emit the sequence. */
6023 record_insns (seq, NULL, &epilogue_insn_hash);
6024 set_insn_locations (seq, epilogue_location);
6025
6026 emit_insn_before (seq, insn);
6027 }
6028 }
6029
6030 if (epilogue_seq)
6031 {
6032 rtx_insn *insn, *next;
6033
6034 /* Similarly, move any line notes that appear after the epilogue.
6035 There is no need, however, to be quite so anal about the existence
6036 of such a note. Also possibly move
6037 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
6038 info generation. */
6039 for (insn = epilogue_seq; insn; insn = next)
6040 {
6041 next = NEXT_INSN (insn);
6042 if (NOTE_P (insn)
6043 && (NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG))
6044 reorder_insns (insn, insn, PREV_INSN (epilogue_seq));
6045 }
6046 }
6047
6048 /* Threading the prologue and epilogue changes the artificial refs
6049 in the entry and exit blocks. */
6050 epilogue_completed = 1;
6051 df_update_entry_exit_and_calls ();
6052 }
6053
6054 /* Reposition the prologue-end and epilogue-begin notes after
6055 instruction scheduling. */
6056
6057 void
6058 reposition_prologue_and_epilogue_notes (void)
6059 {
6060 if (!targetm.have_prologue ()
6061 && !targetm.have_epilogue ()
6062 && !targetm.have_sibcall_epilogue ())
6063 return;
6064
6065 /* Since the hash table is created on demand, the fact that it is
6066 non-null is a signal that it is non-empty. */
6067 if (prologue_insn_hash != NULL)
6068 {
6069 size_t len = prologue_insn_hash->elements ();
6070 rtx_insn *insn, *last = NULL, *note = NULL;
6071
6072 /* Scan from the beginning until we reach the last prologue insn. */
6073 /* ??? While we do have the CFG intact, there are two problems:
6074 (1) The prologue can contain loops (typically probing the stack),
6075 which means that the end of the prologue isn't in the first bb.
6076 (2) Sometimes the PROLOGUE_END note gets pushed into the next bb. */
6077 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
6078 {
6079 if (NOTE_P (insn))
6080 {
6081 if (NOTE_KIND (insn) == NOTE_INSN_PROLOGUE_END)
6082 note = insn;
6083 }
6084 else if (contains (insn, prologue_insn_hash))
6085 {
6086 last = insn;
6087 if (--len == 0)
6088 break;
6089 }
6090 }
6091
6092 if (last)
6093 {
6094 if (note == NULL)
6095 {
6096 /* Scan forward looking for the PROLOGUE_END note. It should
6097 be right at the beginning of the block, possibly with other
6098 insn notes that got moved there. */
6099 for (note = NEXT_INSN (last); ; note = NEXT_INSN (note))
6100 {
6101 if (NOTE_P (note)
6102 && NOTE_KIND (note) == NOTE_INSN_PROLOGUE_END)
6103 break;
6104 }
6105 }
6106
6107 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
6108 if (LABEL_P (last))
6109 last = NEXT_INSN (last);
6110 reorder_insns (note, note, last);
6111 }
6112 }
6113
6114 if (epilogue_insn_hash != NULL)
6115 {
6116 edge_iterator ei;
6117 edge e;
6118
6119 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
6120 {
6121 rtx_insn *insn, *first = NULL, *note = NULL;
6122 basic_block bb = e->src;
6123
6124 /* Scan from the beginning until we reach the first epilogue insn. */
6125 FOR_BB_INSNS (bb, insn)
6126 {
6127 if (NOTE_P (insn))
6128 {
6129 if (NOTE_KIND (insn) == NOTE_INSN_EPILOGUE_BEG)
6130 {
6131 note = insn;
6132 if (first != NULL)
6133 break;
6134 }
6135 }
6136 else if (first == NULL && contains (insn, epilogue_insn_hash))
6137 {
6138 first = insn;
6139 if (note != NULL)
6140 break;
6141 }
6142 }
6143
6144 if (note)
6145 {
6146 /* If the function has a single basic block, and no real
6147 epilogue insns (e.g. sibcall with no cleanup), the
6148 epilogue note can get scheduled before the prologue
6149 note. If we have frame related prologue insns, having
6150 them scanned during the epilogue will result in a crash.
6151 In this case re-order the epilogue note to just before
6152 the last insn in the block. */
6153 if (first == NULL)
6154 first = BB_END (bb);
6155
6156 if (PREV_INSN (first) != note)
6157 reorder_insns (note, note, PREV_INSN (first));
6158 }
6159 }
6160 }
6161 }
6162
6163 /* Returns the name of function declared by FNDECL. */
6164 const char *
6165 fndecl_name (tree fndecl)
6166 {
6167 if (fndecl == NULL)
6168 return "(nofn)";
6169 return lang_hooks.decl_printable_name (fndecl, 1);
6170 }
6171
6172 /* Returns the name of function FN. */
6173 const char *
6174 function_name (struct function *fn)
6175 {
6176 tree fndecl = (fn == NULL) ? NULL : fn->decl;
6177 return fndecl_name (fndecl);
6178 }
6179
6180 /* Returns the name of the current function. */
6181 const char *
6182 current_function_name (void)
6183 {
6184 return function_name (cfun);
6185 }
6186 \f
6187
6188 static unsigned int
6189 rest_of_handle_check_leaf_regs (void)
6190 {
6191 #ifdef LEAF_REGISTERS
6192 crtl->uses_only_leaf_regs
6193 = optimize > 0 && only_leaf_regs_used () && leaf_function_p ();
6194 #endif
6195 return 0;
6196 }
6197
6198 /* Insert a TYPE into the used types hash table of CFUN. */
6199
6200 static void
6201 used_types_insert_helper (tree type, struct function *func)
6202 {
6203 if (type != NULL && func != NULL)
6204 {
6205 if (func->used_types_hash == NULL)
6206 func->used_types_hash = hash_set<tree>::create_ggc (37);
6207
6208 func->used_types_hash->add (type);
6209 }
6210 }
6211
6212 /* Given a type, insert it into the used hash table in cfun. */
6213 void
6214 used_types_insert (tree t)
6215 {
6216 while (POINTER_TYPE_P (t) || TREE_CODE (t) == ARRAY_TYPE)
6217 if (TYPE_NAME (t))
6218 break;
6219 else
6220 t = TREE_TYPE (t);
6221 if (TREE_CODE (t) == ERROR_MARK)
6222 return;
6223 if (TYPE_NAME (t) == NULL_TREE
6224 || TYPE_NAME (t) == TYPE_NAME (TYPE_MAIN_VARIANT (t)))
6225 t = TYPE_MAIN_VARIANT (t);
6226 if (debug_info_level > DINFO_LEVEL_NONE)
6227 {
6228 if (cfun)
6229 used_types_insert_helper (t, cfun);
6230 else
6231 {
6232 /* So this might be a type referenced by a global variable.
6233 Record that type so that we can later decide to emit its
6234 debug information. */
6235 vec_safe_push (types_used_by_cur_var_decl, t);
6236 }
6237 }
6238 }
6239
6240 /* Helper to Hash a struct types_used_by_vars_entry. */
6241
6242 static hashval_t
6243 hash_types_used_by_vars_entry (const struct types_used_by_vars_entry *entry)
6244 {
6245 gcc_assert (entry && entry->var_decl && entry->type);
6246
6247 return iterative_hash_object (entry->type,
6248 iterative_hash_object (entry->var_decl, 0));
6249 }
6250
6251 /* Hash function of the types_used_by_vars_entry hash table. */
6252
6253 hashval_t
6254 used_type_hasher::hash (types_used_by_vars_entry *entry)
6255 {
6256 return hash_types_used_by_vars_entry (entry);
6257 }
6258
6259 /*Equality function of the types_used_by_vars_entry hash table. */
6260
6261 bool
6262 used_type_hasher::equal (types_used_by_vars_entry *e1,
6263 types_used_by_vars_entry *e2)
6264 {
6265 return (e1->var_decl == e2->var_decl && e1->type == e2->type);
6266 }
6267
6268 /* Inserts an entry into the types_used_by_vars_hash hash table. */
6269
6270 void
6271 types_used_by_var_decl_insert (tree type, tree var_decl)
6272 {
6273 if (type != NULL && var_decl != NULL)
6274 {
6275 types_used_by_vars_entry **slot;
6276 struct types_used_by_vars_entry e;
6277 e.var_decl = var_decl;
6278 e.type = type;
6279 if (types_used_by_vars_hash == NULL)
6280 types_used_by_vars_hash
6281 = hash_table<used_type_hasher>::create_ggc (37);
6282
6283 slot = types_used_by_vars_hash->find_slot (&e, INSERT);
6284 if (*slot == NULL)
6285 {
6286 struct types_used_by_vars_entry *entry;
6287 entry = ggc_alloc<types_used_by_vars_entry> ();
6288 entry->type = type;
6289 entry->var_decl = var_decl;
6290 *slot = entry;
6291 }
6292 }
6293 }
6294
6295 namespace {
6296
6297 const pass_data pass_data_leaf_regs =
6298 {
6299 RTL_PASS, /* type */
6300 "*leaf_regs", /* name */
6301 OPTGROUP_NONE, /* optinfo_flags */
6302 TV_NONE, /* tv_id */
6303 0, /* properties_required */
6304 0, /* properties_provided */
6305 0, /* properties_destroyed */
6306 0, /* todo_flags_start */
6307 0, /* todo_flags_finish */
6308 };
6309
6310 class pass_leaf_regs : public rtl_opt_pass
6311 {
6312 public:
6313 pass_leaf_regs (gcc::context *ctxt)
6314 : rtl_opt_pass (pass_data_leaf_regs, ctxt)
6315 {}
6316
6317 /* opt_pass methods: */
6318 virtual unsigned int execute (function *)
6319 {
6320 return rest_of_handle_check_leaf_regs ();
6321 }
6322
6323 }; // class pass_leaf_regs
6324
6325 } // anon namespace
6326
6327 rtl_opt_pass *
6328 make_pass_leaf_regs (gcc::context *ctxt)
6329 {
6330 return new pass_leaf_regs (ctxt);
6331 }
6332
6333 static unsigned int
6334 rest_of_handle_thread_prologue_and_epilogue (void)
6335 {
6336 /* prepare_shrink_wrap is sensitive to the block structure of the control
6337 flow graph, so clean it up first. */
6338 if (optimize)
6339 cleanup_cfg (0);
6340
6341 /* On some machines, the prologue and epilogue code, or parts thereof,
6342 can be represented as RTL. Doing so lets us schedule insns between
6343 it and the rest of the code and also allows delayed branch
6344 scheduling to operate in the epilogue. */
6345 thread_prologue_and_epilogue_insns ();
6346
6347 /* Some non-cold blocks may now be only reachable from cold blocks.
6348 Fix that up. */
6349 fixup_partitions ();
6350
6351 /* Shrink-wrapping can result in unreachable edges in the epilogue,
6352 see PR57320. */
6353 cleanup_cfg (optimize ? CLEANUP_EXPENSIVE : 0);
6354
6355 /* The stack usage info is finalized during prologue expansion. */
6356 if (flag_stack_usage_info)
6357 output_stack_usage ();
6358
6359 return 0;
6360 }
6361
6362 namespace {
6363
6364 const pass_data pass_data_thread_prologue_and_epilogue =
6365 {
6366 RTL_PASS, /* type */
6367 "pro_and_epilogue", /* name */
6368 OPTGROUP_NONE, /* optinfo_flags */
6369 TV_THREAD_PROLOGUE_AND_EPILOGUE, /* tv_id */
6370 0, /* properties_required */
6371 0, /* properties_provided */
6372 0, /* properties_destroyed */
6373 0, /* todo_flags_start */
6374 ( TODO_df_verify | TODO_df_finish ), /* todo_flags_finish */
6375 };
6376
6377 class pass_thread_prologue_and_epilogue : public rtl_opt_pass
6378 {
6379 public:
6380 pass_thread_prologue_and_epilogue (gcc::context *ctxt)
6381 : rtl_opt_pass (pass_data_thread_prologue_and_epilogue, ctxt)
6382 {}
6383
6384 /* opt_pass methods: */
6385 virtual unsigned int execute (function *)
6386 {
6387 return rest_of_handle_thread_prologue_and_epilogue ();
6388 }
6389
6390 }; // class pass_thread_prologue_and_epilogue
6391
6392 } // anon namespace
6393
6394 rtl_opt_pass *
6395 make_pass_thread_prologue_and_epilogue (gcc::context *ctxt)
6396 {
6397 return new pass_thread_prologue_and_epilogue (ctxt);
6398 }
6399 \f
6400
6401 /* If CONSTRAINT is a matching constraint, then return its number.
6402 Otherwise, return -1. */
6403
6404 static int
6405 matching_constraint_num (const char *constraint)
6406 {
6407 if (*constraint == '%')
6408 constraint++;
6409
6410 if (IN_RANGE (*constraint, '0', '9'))
6411 return strtoul (constraint, NULL, 10);
6412
6413 return -1;
6414 }
6415
6416 /* This mini-pass fixes fall-out from SSA in asm statements that have
6417 in-out constraints. Say you start with
6418
6419 orig = inout;
6420 asm ("": "+mr" (inout));
6421 use (orig);
6422
6423 which is transformed very early to use explicit output and match operands:
6424
6425 orig = inout;
6426 asm ("": "=mr" (inout) : "0" (inout));
6427 use (orig);
6428
6429 Or, after SSA and copyprop,
6430
6431 asm ("": "=mr" (inout_2) : "0" (inout_1));
6432 use (inout_1);
6433
6434 Clearly inout_2 and inout_1 can't be coalesced easily anymore, as
6435 they represent two separate values, so they will get different pseudo
6436 registers during expansion. Then, since the two operands need to match
6437 per the constraints, but use different pseudo registers, reload can
6438 only register a reload for these operands. But reloads can only be
6439 satisfied by hardregs, not by memory, so we need a register for this
6440 reload, just because we are presented with non-matching operands.
6441 So, even though we allow memory for this operand, no memory can be
6442 used for it, just because the two operands don't match. This can
6443 cause reload failures on register-starved targets.
6444
6445 So it's a symptom of reload not being able to use memory for reloads
6446 or, alternatively it's also a symptom of both operands not coming into
6447 reload as matching (in which case the pseudo could go to memory just
6448 fine, as the alternative allows it, and no reload would be necessary).
6449 We fix the latter problem here, by transforming
6450
6451 asm ("": "=mr" (inout_2) : "0" (inout_1));
6452
6453 back to
6454
6455 inout_2 = inout_1;
6456 asm ("": "=mr" (inout_2) : "0" (inout_2)); */
6457
6458 static void
6459 match_asm_constraints_1 (rtx_insn *insn, rtx *p_sets, int noutputs)
6460 {
6461 int i;
6462 bool changed = false;
6463 rtx op = SET_SRC (p_sets[0]);
6464 int ninputs = ASM_OPERANDS_INPUT_LENGTH (op);
6465 rtvec inputs = ASM_OPERANDS_INPUT_VEC (op);
6466 bool *output_matched = XALLOCAVEC (bool, noutputs);
6467
6468 memset (output_matched, 0, noutputs * sizeof (bool));
6469 for (i = 0; i < ninputs; i++)
6470 {
6471 rtx input, output;
6472 rtx_insn *insns;
6473 const char *constraint = ASM_OPERANDS_INPUT_CONSTRAINT (op, i);
6474 int match, j;
6475
6476 match = matching_constraint_num (constraint);
6477 if (match < 0)
6478 continue;
6479
6480 gcc_assert (match < noutputs);
6481 output = SET_DEST (p_sets[match]);
6482 input = RTVEC_ELT (inputs, i);
6483 /* Only do the transformation for pseudos. */
6484 if (! REG_P (output)
6485 || rtx_equal_p (output, input)
6486 || !(REG_P (input) || SUBREG_P (input)
6487 || MEM_P (input) || CONSTANT_P (input))
6488 || !general_operand (input, GET_MODE (output)))
6489 continue;
6490
6491 /* We can't do anything if the output is also used as input,
6492 as we're going to overwrite it. */
6493 for (j = 0; j < ninputs; j++)
6494 if (reg_overlap_mentioned_p (output, RTVEC_ELT (inputs, j)))
6495 break;
6496 if (j != ninputs)
6497 continue;
6498
6499 /* Avoid changing the same input several times. For
6500 asm ("" : "=mr" (out1), "=mr" (out2) : "0" (in), "1" (in));
6501 only change it once (to out1), rather than changing it
6502 first to out1 and afterwards to out2. */
6503 if (i > 0)
6504 {
6505 for (j = 0; j < noutputs; j++)
6506 if (output_matched[j] && input == SET_DEST (p_sets[j]))
6507 break;
6508 if (j != noutputs)
6509 continue;
6510 }
6511 output_matched[match] = true;
6512
6513 start_sequence ();
6514 emit_move_insn (output, copy_rtx (input));
6515 insns = get_insns ();
6516 end_sequence ();
6517 emit_insn_before (insns, insn);
6518
6519 constraint = ASM_OPERANDS_OUTPUT_CONSTRAINT(SET_SRC(p_sets[match]));
6520 bool early_clobber_p = strchr (constraint, '&') != NULL;
6521
6522 /* Now replace all mentions of the input with output. We can't
6523 just replace the occurrence in inputs[i], as the register might
6524 also be used in some other input (or even in an address of an
6525 output), which would mean possibly increasing the number of
6526 inputs by one (namely 'output' in addition), which might pose
6527 a too complicated problem for reload to solve. E.g. this situation:
6528
6529 asm ("" : "=r" (output), "=m" (input) : "0" (input))
6530
6531 Here 'input' is used in two occurrences as input (once for the
6532 input operand, once for the address in the second output operand).
6533 If we would replace only the occurrence of the input operand (to
6534 make the matching) we would be left with this:
6535
6536 output = input
6537 asm ("" : "=r" (output), "=m" (input) : "0" (output))
6538
6539 Now we suddenly have two different input values (containing the same
6540 value, but different pseudos) where we formerly had only one.
6541 With more complicated asms this might lead to reload failures
6542 which wouldn't have happen without this pass. So, iterate over
6543 all operands and replace all occurrences of the register used.
6544
6545 However, if one or more of the 'input' uses have a non-matching
6546 constraint and the matched output operand is an early clobber
6547 operand, then do not replace the input operand, since by definition
6548 it conflicts with the output operand and cannot share the same
6549 register. See PR89313 for details. */
6550
6551 for (j = 0; j < noutputs; j++)
6552 if (!rtx_equal_p (SET_DEST (p_sets[j]), input)
6553 && reg_overlap_mentioned_p (input, SET_DEST (p_sets[j])))
6554 SET_DEST (p_sets[j]) = replace_rtx (SET_DEST (p_sets[j]),
6555 input, output);
6556 for (j = 0; j < ninputs; j++)
6557 if (reg_overlap_mentioned_p (input, RTVEC_ELT (inputs, j)))
6558 {
6559 if (!early_clobber_p
6560 || match == matching_constraint_num
6561 (ASM_OPERANDS_INPUT_CONSTRAINT (op, j)))
6562 RTVEC_ELT (inputs, j) = replace_rtx (RTVEC_ELT (inputs, j),
6563 input, output);
6564 }
6565
6566 changed = true;
6567 }
6568
6569 if (changed)
6570 df_insn_rescan (insn);
6571 }
6572
6573 /* Add the decl D to the local_decls list of FUN. */
6574
6575 void
6576 add_local_decl (struct function *fun, tree d)
6577 {
6578 gcc_assert (VAR_P (d));
6579 vec_safe_push (fun->local_decls, d);
6580 }
6581
6582 namespace {
6583
6584 const pass_data pass_data_match_asm_constraints =
6585 {
6586 RTL_PASS, /* type */
6587 "asmcons", /* name */
6588 OPTGROUP_NONE, /* optinfo_flags */
6589 TV_NONE, /* tv_id */
6590 0, /* properties_required */
6591 0, /* properties_provided */
6592 0, /* properties_destroyed */
6593 0, /* todo_flags_start */
6594 0, /* todo_flags_finish */
6595 };
6596
6597 class pass_match_asm_constraints : public rtl_opt_pass
6598 {
6599 public:
6600 pass_match_asm_constraints (gcc::context *ctxt)
6601 : rtl_opt_pass (pass_data_match_asm_constraints, ctxt)
6602 {}
6603
6604 /* opt_pass methods: */
6605 virtual unsigned int execute (function *);
6606
6607 }; // class pass_match_asm_constraints
6608
6609 unsigned
6610 pass_match_asm_constraints::execute (function *fun)
6611 {
6612 basic_block bb;
6613 rtx_insn *insn;
6614 rtx pat, *p_sets;
6615 int noutputs;
6616
6617 if (!crtl->has_asm_statement)
6618 return 0;
6619
6620 df_set_flags (DF_DEFER_INSN_RESCAN);
6621 FOR_EACH_BB_FN (bb, fun)
6622 {
6623 FOR_BB_INSNS (bb, insn)
6624 {
6625 if (!INSN_P (insn))
6626 continue;
6627
6628 pat = PATTERN (insn);
6629 if (GET_CODE (pat) == PARALLEL)
6630 p_sets = &XVECEXP (pat, 0, 0), noutputs = XVECLEN (pat, 0);
6631 else if (GET_CODE (pat) == SET)
6632 p_sets = &PATTERN (insn), noutputs = 1;
6633 else
6634 continue;
6635
6636 if (GET_CODE (*p_sets) == SET
6637 && GET_CODE (SET_SRC (*p_sets)) == ASM_OPERANDS)
6638 match_asm_constraints_1 (insn, p_sets, noutputs);
6639 }
6640 }
6641
6642 return TODO_df_finish;
6643 }
6644
6645 } // anon namespace
6646
6647 rtl_opt_pass *
6648 make_pass_match_asm_constraints (gcc::context *ctxt)
6649 {
6650 return new pass_match_asm_constraints (ctxt);
6651 }
6652
6653
6654 #include "gt-function.h"