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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 struct 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 struct 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 struct frame_space **psp;
445
446 for (psp = &crtl->frame_space_list; *psp; psp = &(*psp)->next)
447 {
448 struct 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 struct GTY(()) temp_slot {
560 /* Points to next temporary slot. */
561 struct temp_slot *next;
562 /* Points to previous temporary slot. */
563 struct temp_slot *prev;
564 /* The rtx to used to reference the slot. */
565 rtx slot;
566 /* The size, in units, of the slot. */
567 poly_int64 size;
568 /* The type of the object in the slot, or zero if it doesn't correspond
569 to a type. We use this to determine whether a slot can be reused.
570 It can be reused if objects of the type of the new slot will always
571 conflict with objects of the type of the old slot. */
572 tree type;
573 /* The alignment (in bits) of the slot. */
574 unsigned int align;
575 /* Nonzero if this temporary is currently in use. */
576 char in_use;
577 /* Nesting level at which this slot is being used. */
578 int level;
579 /* The offset of the slot from the frame_pointer, including extra space
580 for alignment. This info is for combine_temp_slots. */
581 poly_int64 base_offset;
582 /* The size of the slot, including extra space for alignment. This
583 info is for combine_temp_slots. */
584 poly_int64 full_size;
585 };
586
587 /* Entry for the below hash table. */
588 struct GTY((for_user)) temp_slot_address_entry {
589 hashval_t hash;
590 rtx address;
591 struct temp_slot *temp_slot;
592 };
593
594 struct temp_address_hasher : ggc_ptr_hash<temp_slot_address_entry>
595 {
596 static hashval_t hash (temp_slot_address_entry *);
597 static bool equal (temp_slot_address_entry *, temp_slot_address_entry *);
598 };
599
600 /* A table of addresses that represent a stack slot. The table is a mapping
601 from address RTXen to a temp slot. */
602 static GTY(()) hash_table<temp_address_hasher> *temp_slot_address_table;
603 static size_t n_temp_slots_in_use;
604
605 /* Removes temporary slot TEMP from LIST. */
606
607 static void
608 cut_slot_from_list (struct temp_slot *temp, struct temp_slot **list)
609 {
610 if (temp->next)
611 temp->next->prev = temp->prev;
612 if (temp->prev)
613 temp->prev->next = temp->next;
614 else
615 *list = temp->next;
616
617 temp->prev = temp->next = NULL;
618 }
619
620 /* Inserts temporary slot TEMP to LIST. */
621
622 static void
623 insert_slot_to_list (struct temp_slot *temp, struct temp_slot **list)
624 {
625 temp->next = *list;
626 if (*list)
627 (*list)->prev = temp;
628 temp->prev = NULL;
629 *list = temp;
630 }
631
632 /* Returns the list of used temp slots at LEVEL. */
633
634 static struct temp_slot **
635 temp_slots_at_level (int level)
636 {
637 if (level >= (int) vec_safe_length (used_temp_slots))
638 vec_safe_grow_cleared (used_temp_slots, level + 1);
639
640 return &(*used_temp_slots)[level];
641 }
642
643 /* Returns the maximal temporary slot level. */
644
645 static int
646 max_slot_level (void)
647 {
648 if (!used_temp_slots)
649 return -1;
650
651 return used_temp_slots->length () - 1;
652 }
653
654 /* Moves temporary slot TEMP to LEVEL. */
655
656 static void
657 move_slot_to_level (struct temp_slot *temp, int level)
658 {
659 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
660 insert_slot_to_list (temp, temp_slots_at_level (level));
661 temp->level = level;
662 }
663
664 /* Make temporary slot TEMP available. */
665
666 static void
667 make_slot_available (struct temp_slot *temp)
668 {
669 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
670 insert_slot_to_list (temp, &avail_temp_slots);
671 temp->in_use = 0;
672 temp->level = -1;
673 n_temp_slots_in_use--;
674 }
675
676 /* Compute the hash value for an address -> temp slot mapping.
677 The value is cached on the mapping entry. */
678 static hashval_t
679 temp_slot_address_compute_hash (struct temp_slot_address_entry *t)
680 {
681 int do_not_record = 0;
682 return hash_rtx (t->address, GET_MODE (t->address),
683 &do_not_record, NULL, false);
684 }
685
686 /* Return the hash value for an address -> temp slot mapping. */
687 hashval_t
688 temp_address_hasher::hash (temp_slot_address_entry *t)
689 {
690 return t->hash;
691 }
692
693 /* Compare two address -> temp slot mapping entries. */
694 bool
695 temp_address_hasher::equal (temp_slot_address_entry *t1,
696 temp_slot_address_entry *t2)
697 {
698 return exp_equiv_p (t1->address, t2->address, 0, true);
699 }
700
701 /* Add ADDRESS as an alias of TEMP_SLOT to the addess -> temp slot mapping. */
702 static void
703 insert_temp_slot_address (rtx address, struct temp_slot *temp_slot)
704 {
705 struct temp_slot_address_entry *t = ggc_alloc<temp_slot_address_entry> ();
706 t->address = address;
707 t->temp_slot = temp_slot;
708 t->hash = temp_slot_address_compute_hash (t);
709 *temp_slot_address_table->find_slot_with_hash (t, t->hash, INSERT) = t;
710 }
711
712 /* Remove an address -> temp slot mapping entry if the temp slot is
713 not in use anymore. Callback for remove_unused_temp_slot_addresses. */
714 int
715 remove_unused_temp_slot_addresses_1 (temp_slot_address_entry **slot, void *)
716 {
717 const struct temp_slot_address_entry *t = *slot;
718 if (! t->temp_slot->in_use)
719 temp_slot_address_table->clear_slot (slot);
720 return 1;
721 }
722
723 /* Remove all mappings of addresses to unused temp slots. */
724 static void
725 remove_unused_temp_slot_addresses (void)
726 {
727 /* Use quicker clearing if there aren't any active temp slots. */
728 if (n_temp_slots_in_use)
729 temp_slot_address_table->traverse
730 <void *, remove_unused_temp_slot_addresses_1> (NULL);
731 else
732 temp_slot_address_table->empty ();
733 }
734
735 /* Find the temp slot corresponding to the object at address X. */
736
737 static struct temp_slot *
738 find_temp_slot_from_address (rtx x)
739 {
740 struct temp_slot *p;
741 struct temp_slot_address_entry tmp, *t;
742
743 /* First try the easy way:
744 See if X exists in the address -> temp slot mapping. */
745 tmp.address = x;
746 tmp.temp_slot = NULL;
747 tmp.hash = temp_slot_address_compute_hash (&tmp);
748 t = temp_slot_address_table->find_with_hash (&tmp, tmp.hash);
749 if (t)
750 return t->temp_slot;
751
752 /* If we have a sum involving a register, see if it points to a temp
753 slot. */
754 if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 0))
755 && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
756 return p;
757 else if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 1))
758 && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
759 return p;
760
761 /* Last resort: Address is a virtual stack var address. */
762 poly_int64 offset;
763 if (strip_offset (x, &offset) == virtual_stack_vars_rtx)
764 {
765 int i;
766 for (i = max_slot_level (); i >= 0; i--)
767 for (p = *temp_slots_at_level (i); p; p = p->next)
768 if (known_in_range_p (offset, p->base_offset, p->full_size))
769 return p;
770 }
771
772 return NULL;
773 }
774 \f
775 /* Allocate a temporary stack slot and record it for possible later
776 reuse.
777
778 MODE is the machine mode to be given to the returned rtx.
779
780 SIZE is the size in units of the space required. We do no rounding here
781 since assign_stack_local will do any required rounding.
782
783 TYPE is the type that will be used for the stack slot. */
784
785 rtx
786 assign_stack_temp_for_type (machine_mode mode, poly_int64 size, tree type)
787 {
788 unsigned int align;
789 struct temp_slot *p, *best_p = 0, *selected = NULL, **pp;
790 rtx slot;
791
792 gcc_assert (known_size_p (size));
793
794 align = get_stack_local_alignment (type, mode);
795
796 /* Try to find an available, already-allocated temporary of the proper
797 mode which meets the size and alignment requirements. Choose the
798 smallest one with the closest alignment.
799
800 If assign_stack_temp is called outside of the tree->rtl expansion,
801 we cannot reuse the stack slots (that may still refer to
802 VIRTUAL_STACK_VARS_REGNUM). */
803 if (!virtuals_instantiated)
804 {
805 for (p = avail_temp_slots; p; p = p->next)
806 {
807 if (p->align >= align
808 && known_ge (p->size, size)
809 && GET_MODE (p->slot) == mode
810 && objects_must_conflict_p (p->type, type)
811 && (best_p == 0
812 || (known_eq (best_p->size, p->size)
813 ? best_p->align > p->align
814 : known_ge (best_p->size, p->size))))
815 {
816 if (p->align == align && known_eq (p->size, size))
817 {
818 selected = p;
819 cut_slot_from_list (selected, &avail_temp_slots);
820 best_p = 0;
821 break;
822 }
823 best_p = p;
824 }
825 }
826 }
827
828 /* Make our best, if any, the one to use. */
829 if (best_p)
830 {
831 selected = best_p;
832 cut_slot_from_list (selected, &avail_temp_slots);
833
834 /* If there are enough aligned bytes left over, make them into a new
835 temp_slot so that the extra bytes don't get wasted. Do this only
836 for BLKmode slots, so that we can be sure of the alignment. */
837 if (GET_MODE (best_p->slot) == BLKmode)
838 {
839 int alignment = best_p->align / BITS_PER_UNIT;
840 poly_int64 rounded_size = aligned_upper_bound (size, alignment);
841
842 if (known_ge (best_p->size - rounded_size, alignment))
843 {
844 p = ggc_alloc<temp_slot> ();
845 p->in_use = 0;
846 p->size = best_p->size - rounded_size;
847 p->base_offset = best_p->base_offset + rounded_size;
848 p->full_size = best_p->full_size - rounded_size;
849 p->slot = adjust_address_nv (best_p->slot, BLKmode, rounded_size);
850 p->align = best_p->align;
851 p->type = best_p->type;
852 insert_slot_to_list (p, &avail_temp_slots);
853
854 vec_safe_push (stack_slot_list, p->slot);
855
856 best_p->size = rounded_size;
857 best_p->full_size = rounded_size;
858 }
859 }
860 }
861
862 /* If we still didn't find one, make a new temporary. */
863 if (selected == 0)
864 {
865 poly_int64 frame_offset_old = frame_offset;
866
867 p = ggc_alloc<temp_slot> ();
868
869 /* We are passing an explicit alignment request to assign_stack_local.
870 One side effect of that is assign_stack_local will not round SIZE
871 to ensure the frame offset remains suitably aligned.
872
873 So for requests which depended on the rounding of SIZE, we go ahead
874 and round it now. We also make sure ALIGNMENT is at least
875 BIGGEST_ALIGNMENT. */
876 gcc_assert (mode != BLKmode || align == BIGGEST_ALIGNMENT);
877 p->slot = assign_stack_local_1 (mode,
878 (mode == BLKmode
879 ? aligned_upper_bound (size,
880 (int) align
881 / BITS_PER_UNIT)
882 : size),
883 align, 0);
884
885 p->align = align;
886
887 /* The following slot size computation is necessary because we don't
888 know the actual size of the temporary slot until assign_stack_local
889 has performed all the frame alignment and size rounding for the
890 requested temporary. Note that extra space added for alignment
891 can be either above or below this stack slot depending on which
892 way the frame grows. We include the extra space if and only if it
893 is above this slot. */
894 if (FRAME_GROWS_DOWNWARD)
895 p->size = frame_offset_old - frame_offset;
896 else
897 p->size = size;
898
899 /* Now define the fields used by combine_temp_slots. */
900 if (FRAME_GROWS_DOWNWARD)
901 {
902 p->base_offset = frame_offset;
903 p->full_size = frame_offset_old - frame_offset;
904 }
905 else
906 {
907 p->base_offset = frame_offset_old;
908 p->full_size = frame_offset - frame_offset_old;
909 }
910
911 selected = p;
912 }
913
914 p = selected;
915 p->in_use = 1;
916 p->type = type;
917 p->level = temp_slot_level;
918 n_temp_slots_in_use++;
919
920 pp = temp_slots_at_level (p->level);
921 insert_slot_to_list (p, pp);
922 insert_temp_slot_address (XEXP (p->slot, 0), p);
923
924 /* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
925 slot = gen_rtx_MEM (mode, XEXP (p->slot, 0));
926 vec_safe_push (stack_slot_list, slot);
927
928 /* If we know the alias set for the memory that will be used, use
929 it. If there's no TYPE, then we don't know anything about the
930 alias set for the memory. */
931 set_mem_alias_set (slot, type ? get_alias_set (type) : 0);
932 set_mem_align (slot, align);
933
934 /* If a type is specified, set the relevant flags. */
935 if (type != 0)
936 MEM_VOLATILE_P (slot) = TYPE_VOLATILE (type);
937 MEM_NOTRAP_P (slot) = 1;
938
939 return slot;
940 }
941
942 /* Allocate a temporary stack slot and record it for possible later
943 reuse. First two arguments are same as in preceding function. */
944
945 rtx
946 assign_stack_temp (machine_mode mode, poly_int64 size)
947 {
948 return assign_stack_temp_for_type (mode, size, NULL_TREE);
949 }
950 \f
951 /* Assign a temporary.
952 If TYPE_OR_DECL is a decl, then we are doing it on behalf of the decl
953 and so that should be used in error messages. In either case, we
954 allocate of the given type.
955 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
956 it is 0 if a register is OK.
957 DONT_PROMOTE is 1 if we should not promote values in register
958 to wider modes. */
959
960 rtx
961 assign_temp (tree type_or_decl, int memory_required,
962 int dont_promote ATTRIBUTE_UNUSED)
963 {
964 tree type, decl;
965 machine_mode mode;
966 #ifdef PROMOTE_MODE
967 int unsignedp;
968 #endif
969
970 if (DECL_P (type_or_decl))
971 decl = type_or_decl, type = TREE_TYPE (decl);
972 else
973 decl = NULL, type = type_or_decl;
974
975 mode = TYPE_MODE (type);
976 #ifdef PROMOTE_MODE
977 unsignedp = TYPE_UNSIGNED (type);
978 #endif
979
980 /* Allocating temporaries of TREE_ADDRESSABLE type must be done in the front
981 end. See also create_tmp_var for the gimplification-time check. */
982 gcc_assert (!TREE_ADDRESSABLE (type) && COMPLETE_TYPE_P (type));
983
984 if (mode == BLKmode || memory_required)
985 {
986 poly_int64 size;
987 rtx tmp;
988
989 /* Unfortunately, we don't yet know how to allocate variable-sized
990 temporaries. However, sometimes we can find a fixed upper limit on
991 the size, so try that instead. */
992 if (!poly_int_tree_p (TYPE_SIZE_UNIT (type), &size))
993 size = max_int_size_in_bytes (type);
994
995 /* Zero sized arrays are a GNU C extension. Set size to 1 to avoid
996 problems with allocating the stack space. */
997 if (known_eq (size, 0))
998 size = 1;
999
1000 /* The size of the temporary may be too large to fit into an integer. */
1001 /* ??? Not sure this should happen except for user silliness, so limit
1002 this to things that aren't compiler-generated temporaries. The
1003 rest of the time we'll die in assign_stack_temp_for_type. */
1004 if (decl
1005 && !known_size_p (size)
1006 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST)
1007 {
1008 error ("size of variable %q+D is too large", decl);
1009 size = 1;
1010 }
1011
1012 tmp = assign_stack_temp_for_type (mode, size, type);
1013 return tmp;
1014 }
1015
1016 #ifdef PROMOTE_MODE
1017 if (! dont_promote)
1018 mode = promote_mode (type, mode, &unsignedp);
1019 #endif
1020
1021 return gen_reg_rtx (mode);
1022 }
1023 \f
1024 /* Combine temporary stack slots which are adjacent on the stack.
1025
1026 This allows for better use of already allocated stack space. This is only
1027 done for BLKmode slots because we can be sure that we won't have alignment
1028 problems in this case. */
1029
1030 static void
1031 combine_temp_slots (void)
1032 {
1033 struct temp_slot *p, *q, *next, *next_q;
1034 int num_slots;
1035
1036 /* We can't combine slots, because the information about which slot
1037 is in which alias set will be lost. */
1038 if (flag_strict_aliasing)
1039 return;
1040
1041 /* If there are a lot of temp slots, don't do anything unless
1042 high levels of optimization. */
1043 if (! flag_expensive_optimizations)
1044 for (p = avail_temp_slots, num_slots = 0; p; p = p->next, num_slots++)
1045 if (num_slots > 100 || (num_slots > 10 && optimize == 0))
1046 return;
1047
1048 for (p = avail_temp_slots; p; p = next)
1049 {
1050 int delete_p = 0;
1051
1052 next = p->next;
1053
1054 if (GET_MODE (p->slot) != BLKmode)
1055 continue;
1056
1057 for (q = p->next; q; q = next_q)
1058 {
1059 int delete_q = 0;
1060
1061 next_q = q->next;
1062
1063 if (GET_MODE (q->slot) != BLKmode)
1064 continue;
1065
1066 if (known_eq (p->base_offset + p->full_size, q->base_offset))
1067 {
1068 /* Q comes after P; combine Q into P. */
1069 p->size += q->size;
1070 p->full_size += q->full_size;
1071 delete_q = 1;
1072 }
1073 else if (known_eq (q->base_offset + q->full_size, p->base_offset))
1074 {
1075 /* P comes after Q; combine P into Q. */
1076 q->size += p->size;
1077 q->full_size += p->full_size;
1078 delete_p = 1;
1079 break;
1080 }
1081 if (delete_q)
1082 cut_slot_from_list (q, &avail_temp_slots);
1083 }
1084
1085 /* Either delete P or advance past it. */
1086 if (delete_p)
1087 cut_slot_from_list (p, &avail_temp_slots);
1088 }
1089 }
1090 \f
1091 /* Indicate that NEW_RTX is an alternate way of referring to the temp
1092 slot that previously was known by OLD_RTX. */
1093
1094 void
1095 update_temp_slot_address (rtx old_rtx, rtx new_rtx)
1096 {
1097 struct temp_slot *p;
1098
1099 if (rtx_equal_p (old_rtx, new_rtx))
1100 return;
1101
1102 p = find_temp_slot_from_address (old_rtx);
1103
1104 /* If we didn't find one, see if both OLD_RTX is a PLUS. If so, and
1105 NEW_RTX is a register, see if one operand of the PLUS is a
1106 temporary location. If so, NEW_RTX points into it. Otherwise,
1107 if both OLD_RTX and NEW_RTX are a PLUS and if there is a register
1108 in common between them. If so, try a recursive call on those
1109 values. */
1110 if (p == 0)
1111 {
1112 if (GET_CODE (old_rtx) != PLUS)
1113 return;
1114
1115 if (REG_P (new_rtx))
1116 {
1117 update_temp_slot_address (XEXP (old_rtx, 0), new_rtx);
1118 update_temp_slot_address (XEXP (old_rtx, 1), new_rtx);
1119 return;
1120 }
1121 else if (GET_CODE (new_rtx) != PLUS)
1122 return;
1123
1124 if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 0)))
1125 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 1));
1126 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 0)))
1127 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 1));
1128 else if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 1)))
1129 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 0));
1130 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 1)))
1131 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 0));
1132
1133 return;
1134 }
1135
1136 /* Otherwise add an alias for the temp's address. */
1137 insert_temp_slot_address (new_rtx, p);
1138 }
1139
1140 /* If X could be a reference to a temporary slot, mark that slot as
1141 belonging to the to one level higher than the current level. If X
1142 matched one of our slots, just mark that one. Otherwise, we can't
1143 easily predict which it is, so upgrade all of them.
1144
1145 This is called when an ({...}) construct occurs and a statement
1146 returns a value in memory. */
1147
1148 void
1149 preserve_temp_slots (rtx x)
1150 {
1151 struct temp_slot *p = 0, *next;
1152
1153 if (x == 0)
1154 return;
1155
1156 /* If X is a register that is being used as a pointer, see if we have
1157 a temporary slot we know it points to. */
1158 if (REG_P (x) && REG_POINTER (x))
1159 p = find_temp_slot_from_address (x);
1160
1161 /* If X is not in memory or is at a constant address, it cannot be in
1162 a temporary slot. */
1163 if (p == 0 && (!MEM_P (x) || CONSTANT_P (XEXP (x, 0))))
1164 return;
1165
1166 /* First see if we can find a match. */
1167 if (p == 0)
1168 p = find_temp_slot_from_address (XEXP (x, 0));
1169
1170 if (p != 0)
1171 {
1172 if (p->level == temp_slot_level)
1173 move_slot_to_level (p, temp_slot_level - 1);
1174 return;
1175 }
1176
1177 /* Otherwise, preserve all non-kept slots at this level. */
1178 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1179 {
1180 next = p->next;
1181 move_slot_to_level (p, temp_slot_level - 1);
1182 }
1183 }
1184
1185 /* Free all temporaries used so far. This is normally called at the
1186 end of generating code for a statement. */
1187
1188 void
1189 free_temp_slots (void)
1190 {
1191 struct temp_slot *p, *next;
1192 bool some_available = false;
1193
1194 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1195 {
1196 next = p->next;
1197 make_slot_available (p);
1198 some_available = true;
1199 }
1200
1201 if (some_available)
1202 {
1203 remove_unused_temp_slot_addresses ();
1204 combine_temp_slots ();
1205 }
1206 }
1207
1208 /* Push deeper into the nesting level for stack temporaries. */
1209
1210 void
1211 push_temp_slots (void)
1212 {
1213 temp_slot_level++;
1214 }
1215
1216 /* Pop a temporary nesting level. All slots in use in the current level
1217 are freed. */
1218
1219 void
1220 pop_temp_slots (void)
1221 {
1222 free_temp_slots ();
1223 temp_slot_level--;
1224 }
1225
1226 /* Initialize temporary slots. */
1227
1228 void
1229 init_temp_slots (void)
1230 {
1231 /* We have not allocated any temporaries yet. */
1232 avail_temp_slots = 0;
1233 vec_alloc (used_temp_slots, 0);
1234 temp_slot_level = 0;
1235 n_temp_slots_in_use = 0;
1236
1237 /* Set up the table to map addresses to temp slots. */
1238 if (! temp_slot_address_table)
1239 temp_slot_address_table = hash_table<temp_address_hasher>::create_ggc (32);
1240 else
1241 temp_slot_address_table->empty ();
1242 }
1243 \f
1244 /* Functions and data structures to keep track of the values hard regs
1245 had at the start of the function. */
1246
1247 /* Private type used by get_hard_reg_initial_reg, get_hard_reg_initial_val,
1248 and has_hard_reg_initial_val.. */
1249 struct GTY(()) initial_value_pair {
1250 rtx hard_reg;
1251 rtx pseudo;
1252 };
1253 /* ??? This could be a VEC but there is currently no way to define an
1254 opaque VEC type. This could be worked around by defining struct
1255 initial_value_pair in function.h. */
1256 struct GTY(()) initial_value_struct {
1257 int num_entries;
1258 int max_entries;
1259 initial_value_pair * GTY ((length ("%h.num_entries"))) entries;
1260 };
1261
1262 /* If a pseudo represents an initial hard reg (or expression), return
1263 it, else return NULL_RTX. */
1264
1265 rtx
1266 get_hard_reg_initial_reg (rtx reg)
1267 {
1268 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1269 int i;
1270
1271 if (ivs == 0)
1272 return NULL_RTX;
1273
1274 for (i = 0; i < ivs->num_entries; i++)
1275 if (rtx_equal_p (ivs->entries[i].pseudo, reg))
1276 return ivs->entries[i].hard_reg;
1277
1278 return NULL_RTX;
1279 }
1280
1281 /* Make sure that there's a pseudo register of mode MODE that stores the
1282 initial value of hard register REGNO. Return an rtx for such a pseudo. */
1283
1284 rtx
1285 get_hard_reg_initial_val (machine_mode mode, unsigned int regno)
1286 {
1287 struct initial_value_struct *ivs;
1288 rtx rv;
1289
1290 rv = has_hard_reg_initial_val (mode, regno);
1291 if (rv)
1292 return rv;
1293
1294 ivs = crtl->hard_reg_initial_vals;
1295 if (ivs == 0)
1296 {
1297 ivs = ggc_alloc<initial_value_struct> ();
1298 ivs->num_entries = 0;
1299 ivs->max_entries = 5;
1300 ivs->entries = ggc_vec_alloc<initial_value_pair> (5);
1301 crtl->hard_reg_initial_vals = ivs;
1302 }
1303
1304 if (ivs->num_entries >= ivs->max_entries)
1305 {
1306 ivs->max_entries += 5;
1307 ivs->entries = GGC_RESIZEVEC (initial_value_pair, ivs->entries,
1308 ivs->max_entries);
1309 }
1310
1311 ivs->entries[ivs->num_entries].hard_reg = gen_rtx_REG (mode, regno);
1312 ivs->entries[ivs->num_entries].pseudo = gen_reg_rtx (mode);
1313
1314 return ivs->entries[ivs->num_entries++].pseudo;
1315 }
1316
1317 /* See if get_hard_reg_initial_val has been used to create a pseudo
1318 for the initial value of hard register REGNO in mode MODE. Return
1319 the associated pseudo if so, otherwise return NULL. */
1320
1321 rtx
1322 has_hard_reg_initial_val (machine_mode mode, unsigned int regno)
1323 {
1324 struct initial_value_struct *ivs;
1325 int i;
1326
1327 ivs = crtl->hard_reg_initial_vals;
1328 if (ivs != 0)
1329 for (i = 0; i < ivs->num_entries; i++)
1330 if (GET_MODE (ivs->entries[i].hard_reg) == mode
1331 && REGNO (ivs->entries[i].hard_reg) == regno)
1332 return ivs->entries[i].pseudo;
1333
1334 return NULL_RTX;
1335 }
1336
1337 unsigned int
1338 emit_initial_value_sets (void)
1339 {
1340 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1341 int i;
1342 rtx_insn *seq;
1343
1344 if (ivs == 0)
1345 return 0;
1346
1347 start_sequence ();
1348 for (i = 0; i < ivs->num_entries; i++)
1349 emit_move_insn (ivs->entries[i].pseudo, ivs->entries[i].hard_reg);
1350 seq = get_insns ();
1351 end_sequence ();
1352
1353 emit_insn_at_entry (seq);
1354 return 0;
1355 }
1356
1357 /* Return the hardreg-pseudoreg initial values pair entry I and
1358 TRUE if I is a valid entry, or FALSE if I is not a valid entry. */
1359 bool
1360 initial_value_entry (int i, rtx *hreg, rtx *preg)
1361 {
1362 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1363 if (!ivs || i >= ivs->num_entries)
1364 return false;
1365
1366 *hreg = ivs->entries[i].hard_reg;
1367 *preg = ivs->entries[i].pseudo;
1368 return true;
1369 }
1370 \f
1371 /* These routines are responsible for converting virtual register references
1372 to the actual hard register references once RTL generation is complete.
1373
1374 The following four variables are used for communication between the
1375 routines. They contain the offsets of the virtual registers from their
1376 respective hard registers. */
1377
1378 static poly_int64 in_arg_offset;
1379 static poly_int64 var_offset;
1380 static poly_int64 dynamic_offset;
1381 static poly_int64 out_arg_offset;
1382 static poly_int64 cfa_offset;
1383
1384 /* In most machines, the stack pointer register is equivalent to the bottom
1385 of the stack. */
1386
1387 #ifndef STACK_POINTER_OFFSET
1388 #define STACK_POINTER_OFFSET 0
1389 #endif
1390
1391 #if defined (REG_PARM_STACK_SPACE) && !defined (INCOMING_REG_PARM_STACK_SPACE)
1392 #define INCOMING_REG_PARM_STACK_SPACE REG_PARM_STACK_SPACE
1393 #endif
1394
1395 /* If not defined, pick an appropriate default for the offset of dynamically
1396 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
1397 INCOMING_REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
1398
1399 #ifndef STACK_DYNAMIC_OFFSET
1400
1401 /* The bottom of the stack points to the actual arguments. If
1402 REG_PARM_STACK_SPACE is defined, this includes the space for the register
1403 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
1404 stack space for register parameters is not pushed by the caller, but
1405 rather part of the fixed stack areas and hence not included in
1406 `crtl->outgoing_args_size'. Nevertheless, we must allow
1407 for it when allocating stack dynamic objects. */
1408
1409 #ifdef INCOMING_REG_PARM_STACK_SPACE
1410 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1411 ((ACCUMULATE_OUTGOING_ARGS \
1412 ? (crtl->outgoing_args_size \
1413 + (OUTGOING_REG_PARM_STACK_SPACE ((!(FNDECL) ? NULL_TREE : TREE_TYPE (FNDECL))) ? 0 \
1414 : INCOMING_REG_PARM_STACK_SPACE (FNDECL))) \
1415 : 0) + (STACK_POINTER_OFFSET))
1416 #else
1417 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1418 ((ACCUMULATE_OUTGOING_ARGS ? crtl->outgoing_args_size : poly_int64 (0)) \
1419 + (STACK_POINTER_OFFSET))
1420 #endif
1421 #endif
1422
1423 \f
1424 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
1425 is a virtual register, return the equivalent hard register and set the
1426 offset indirectly through the pointer. Otherwise, return 0. */
1427
1428 static rtx
1429 instantiate_new_reg (rtx x, poly_int64_pod *poffset)
1430 {
1431 rtx new_rtx;
1432 poly_int64 offset;
1433
1434 if (x == virtual_incoming_args_rtx)
1435 {
1436 if (stack_realign_drap)
1437 {
1438 /* Replace virtual_incoming_args_rtx with internal arg
1439 pointer if DRAP is used to realign stack. */
1440 new_rtx = crtl->args.internal_arg_pointer;
1441 offset = 0;
1442 }
1443 else
1444 new_rtx = arg_pointer_rtx, offset = in_arg_offset;
1445 }
1446 else if (x == virtual_stack_vars_rtx)
1447 new_rtx = frame_pointer_rtx, offset = var_offset;
1448 else if (x == virtual_stack_dynamic_rtx)
1449 new_rtx = stack_pointer_rtx, offset = dynamic_offset;
1450 else if (x == virtual_outgoing_args_rtx)
1451 new_rtx = stack_pointer_rtx, offset = out_arg_offset;
1452 else if (x == virtual_cfa_rtx)
1453 {
1454 #ifdef FRAME_POINTER_CFA_OFFSET
1455 new_rtx = frame_pointer_rtx;
1456 #else
1457 new_rtx = arg_pointer_rtx;
1458 #endif
1459 offset = cfa_offset;
1460 }
1461 else if (x == virtual_preferred_stack_boundary_rtx)
1462 {
1463 new_rtx = GEN_INT (crtl->preferred_stack_boundary / BITS_PER_UNIT);
1464 offset = 0;
1465 }
1466 else
1467 return NULL_RTX;
1468
1469 *poffset = offset;
1470 return new_rtx;
1471 }
1472
1473 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1474 registers present inside of *LOC. The expression is simplified,
1475 as much as possible, but is not to be considered "valid" in any sense
1476 implied by the target. Return true if any change is made. */
1477
1478 static bool
1479 instantiate_virtual_regs_in_rtx (rtx *loc)
1480 {
1481 if (!*loc)
1482 return false;
1483 bool changed = false;
1484 subrtx_ptr_iterator::array_type array;
1485 FOR_EACH_SUBRTX_PTR (iter, array, loc, NONCONST)
1486 {
1487 rtx *loc = *iter;
1488 if (rtx x = *loc)
1489 {
1490 rtx new_rtx;
1491 poly_int64 offset;
1492 switch (GET_CODE (x))
1493 {
1494 case REG:
1495 new_rtx = instantiate_new_reg (x, &offset);
1496 if (new_rtx)
1497 {
1498 *loc = plus_constant (GET_MODE (x), new_rtx, offset);
1499 changed = true;
1500 }
1501 iter.skip_subrtxes ();
1502 break;
1503
1504 case PLUS:
1505 new_rtx = instantiate_new_reg (XEXP (x, 0), &offset);
1506 if (new_rtx)
1507 {
1508 XEXP (x, 0) = new_rtx;
1509 *loc = plus_constant (GET_MODE (x), x, offset, true);
1510 changed = true;
1511 iter.skip_subrtxes ();
1512 break;
1513 }
1514
1515 /* FIXME -- from old code */
1516 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
1517 we can commute the PLUS and SUBREG because pointers into the
1518 frame are well-behaved. */
1519 break;
1520
1521 default:
1522 break;
1523 }
1524 }
1525 }
1526 return changed;
1527 }
1528
1529 /* A subroutine of instantiate_virtual_regs_in_insn. Return true if X
1530 matches the predicate for insn CODE operand OPERAND. */
1531
1532 static int
1533 safe_insn_predicate (int code, int operand, rtx x)
1534 {
1535 return code < 0 || insn_operand_matches ((enum insn_code) code, operand, x);
1536 }
1537
1538 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1539 registers present inside of insn. The result will be a valid insn. */
1540
1541 static void
1542 instantiate_virtual_regs_in_insn (rtx_insn *insn)
1543 {
1544 poly_int64 offset;
1545 int insn_code, i;
1546 bool any_change = false;
1547 rtx set, new_rtx, x;
1548 rtx_insn *seq;
1549
1550 /* There are some special cases to be handled first. */
1551 set = single_set (insn);
1552 if (set)
1553 {
1554 /* We're allowed to assign to a virtual register. This is interpreted
1555 to mean that the underlying register gets assigned the inverse
1556 transformation. This is used, for example, in the handling of
1557 non-local gotos. */
1558 new_rtx = instantiate_new_reg (SET_DEST (set), &offset);
1559 if (new_rtx)
1560 {
1561 start_sequence ();
1562
1563 instantiate_virtual_regs_in_rtx (&SET_SRC (set));
1564 x = simplify_gen_binary (PLUS, GET_MODE (new_rtx), SET_SRC (set),
1565 gen_int_mode (-offset, GET_MODE (new_rtx)));
1566 x = force_operand (x, new_rtx);
1567 if (x != new_rtx)
1568 emit_move_insn (new_rtx, x);
1569
1570 seq = get_insns ();
1571 end_sequence ();
1572
1573 emit_insn_before (seq, insn);
1574 delete_insn (insn);
1575 return;
1576 }
1577
1578 /* Handle a straight copy from a virtual register by generating a
1579 new add insn. The difference between this and falling through
1580 to the generic case is avoiding a new pseudo and eliminating a
1581 move insn in the initial rtl stream. */
1582 new_rtx = instantiate_new_reg (SET_SRC (set), &offset);
1583 if (new_rtx
1584 && maybe_ne (offset, 0)
1585 && REG_P (SET_DEST (set))
1586 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1587 {
1588 start_sequence ();
1589
1590 x = expand_simple_binop (GET_MODE (SET_DEST (set)), PLUS, new_rtx,
1591 gen_int_mode (offset,
1592 GET_MODE (SET_DEST (set))),
1593 SET_DEST (set), 1, OPTAB_LIB_WIDEN);
1594 if (x != SET_DEST (set))
1595 emit_move_insn (SET_DEST (set), x);
1596
1597 seq = get_insns ();
1598 end_sequence ();
1599
1600 emit_insn_before (seq, insn);
1601 delete_insn (insn);
1602 return;
1603 }
1604
1605 extract_insn (insn);
1606 insn_code = INSN_CODE (insn);
1607
1608 /* Handle a plus involving a virtual register by determining if the
1609 operands remain valid if they're modified in place. */
1610 poly_int64 delta;
1611 if (GET_CODE (SET_SRC (set)) == PLUS
1612 && recog_data.n_operands >= 3
1613 && recog_data.operand_loc[1] == &XEXP (SET_SRC (set), 0)
1614 && recog_data.operand_loc[2] == &XEXP (SET_SRC (set), 1)
1615 && poly_int_rtx_p (recog_data.operand[2], &delta)
1616 && (new_rtx = instantiate_new_reg (recog_data.operand[1], &offset)))
1617 {
1618 offset += delta;
1619
1620 /* If the sum is zero, then replace with a plain move. */
1621 if (known_eq (offset, 0)
1622 && REG_P (SET_DEST (set))
1623 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1624 {
1625 start_sequence ();
1626 emit_move_insn (SET_DEST (set), new_rtx);
1627 seq = get_insns ();
1628 end_sequence ();
1629
1630 emit_insn_before (seq, insn);
1631 delete_insn (insn);
1632 return;
1633 }
1634
1635 x = gen_int_mode (offset, recog_data.operand_mode[2]);
1636
1637 /* Using validate_change and apply_change_group here leaves
1638 recog_data in an invalid state. Since we know exactly what
1639 we want to check, do those two by hand. */
1640 if (safe_insn_predicate (insn_code, 1, new_rtx)
1641 && safe_insn_predicate (insn_code, 2, x))
1642 {
1643 *recog_data.operand_loc[1] = recog_data.operand[1] = new_rtx;
1644 *recog_data.operand_loc[2] = recog_data.operand[2] = x;
1645 any_change = true;
1646
1647 /* Fall through into the regular operand fixup loop in
1648 order to take care of operands other than 1 and 2. */
1649 }
1650 }
1651 }
1652 else
1653 {
1654 extract_insn (insn);
1655 insn_code = INSN_CODE (insn);
1656 }
1657
1658 /* In the general case, we expect virtual registers to appear only in
1659 operands, and then only as either bare registers or inside memories. */
1660 for (i = 0; i < recog_data.n_operands; ++i)
1661 {
1662 x = recog_data.operand[i];
1663 switch (GET_CODE (x))
1664 {
1665 case MEM:
1666 {
1667 rtx addr = XEXP (x, 0);
1668
1669 if (!instantiate_virtual_regs_in_rtx (&addr))
1670 continue;
1671
1672 start_sequence ();
1673 x = replace_equiv_address (x, addr, true);
1674 /* It may happen that the address with the virtual reg
1675 was valid (e.g. based on the virtual stack reg, which might
1676 be acceptable to the predicates with all offsets), whereas
1677 the address now isn't anymore, for instance when the address
1678 is still offsetted, but the base reg isn't virtual-stack-reg
1679 anymore. Below we would do a force_reg on the whole operand,
1680 but this insn might actually only accept memory. Hence,
1681 before doing that last resort, try to reload the address into
1682 a register, so this operand stays a MEM. */
1683 if (!safe_insn_predicate (insn_code, i, x))
1684 {
1685 addr = force_reg (GET_MODE (addr), addr);
1686 x = replace_equiv_address (x, addr, true);
1687 }
1688 seq = get_insns ();
1689 end_sequence ();
1690 if (seq)
1691 emit_insn_before (seq, insn);
1692 }
1693 break;
1694
1695 case REG:
1696 new_rtx = instantiate_new_reg (x, &offset);
1697 if (new_rtx == NULL)
1698 continue;
1699 if (known_eq (offset, 0))
1700 x = new_rtx;
1701 else
1702 {
1703 start_sequence ();
1704
1705 /* Careful, special mode predicates may have stuff in
1706 insn_data[insn_code].operand[i].mode that isn't useful
1707 to us for computing a new value. */
1708 /* ??? Recognize address_operand and/or "p" constraints
1709 to see if (plus new offset) is a valid before we put
1710 this through expand_simple_binop. */
1711 x = expand_simple_binop (GET_MODE (x), PLUS, new_rtx,
1712 gen_int_mode (offset, GET_MODE (x)),
1713 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1714 seq = get_insns ();
1715 end_sequence ();
1716 emit_insn_before (seq, insn);
1717 }
1718 break;
1719
1720 case SUBREG:
1721 new_rtx = instantiate_new_reg (SUBREG_REG (x), &offset);
1722 if (new_rtx == NULL)
1723 continue;
1724 if (maybe_ne (offset, 0))
1725 {
1726 start_sequence ();
1727 new_rtx = expand_simple_binop
1728 (GET_MODE (new_rtx), PLUS, new_rtx,
1729 gen_int_mode (offset, GET_MODE (new_rtx)),
1730 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1731 seq = get_insns ();
1732 end_sequence ();
1733 emit_insn_before (seq, insn);
1734 }
1735 x = simplify_gen_subreg (recog_data.operand_mode[i], new_rtx,
1736 GET_MODE (new_rtx), SUBREG_BYTE (x));
1737 gcc_assert (x);
1738 break;
1739
1740 default:
1741 continue;
1742 }
1743
1744 /* At this point, X contains the new value for the operand.
1745 Validate the new value vs the insn predicate. Note that
1746 asm insns will have insn_code -1 here. */
1747 if (!safe_insn_predicate (insn_code, i, x))
1748 {
1749 start_sequence ();
1750 if (REG_P (x))
1751 {
1752 gcc_assert (REGNO (x) <= LAST_VIRTUAL_REGISTER);
1753 x = copy_to_reg (x);
1754 }
1755 else
1756 x = force_reg (insn_data[insn_code].operand[i].mode, x);
1757 seq = get_insns ();
1758 end_sequence ();
1759 if (seq)
1760 emit_insn_before (seq, insn);
1761 }
1762
1763 *recog_data.operand_loc[i] = recog_data.operand[i] = x;
1764 any_change = true;
1765 }
1766
1767 if (any_change)
1768 {
1769 /* Propagate operand changes into the duplicates. */
1770 for (i = 0; i < recog_data.n_dups; ++i)
1771 *recog_data.dup_loc[i]
1772 = copy_rtx (recog_data.operand[(unsigned)recog_data.dup_num[i]]);
1773
1774 /* Force re-recognition of the instruction for validation. */
1775 INSN_CODE (insn) = -1;
1776 }
1777
1778 if (asm_noperands (PATTERN (insn)) >= 0)
1779 {
1780 if (!check_asm_operands (PATTERN (insn)))
1781 {
1782 error_for_asm (insn, "impossible constraint in %<asm%>");
1783 /* For asm goto, instead of fixing up all the edges
1784 just clear the template and clear input operands
1785 (asm goto doesn't have any output operands). */
1786 if (JUMP_P (insn))
1787 {
1788 rtx asm_op = extract_asm_operands (PATTERN (insn));
1789 ASM_OPERANDS_TEMPLATE (asm_op) = ggc_strdup ("");
1790 ASM_OPERANDS_INPUT_VEC (asm_op) = rtvec_alloc (0);
1791 ASM_OPERANDS_INPUT_CONSTRAINT_VEC (asm_op) = rtvec_alloc (0);
1792 }
1793 else
1794 delete_insn (insn);
1795 }
1796 }
1797 else
1798 {
1799 if (recog_memoized (insn) < 0)
1800 fatal_insn_not_found (insn);
1801 }
1802 }
1803
1804 /* Subroutine of instantiate_decls. Given RTL representing a decl,
1805 do any instantiation required. */
1806
1807 void
1808 instantiate_decl_rtl (rtx x)
1809 {
1810 rtx addr;
1811
1812 if (x == 0)
1813 return;
1814
1815 /* If this is a CONCAT, recurse for the pieces. */
1816 if (GET_CODE (x) == CONCAT)
1817 {
1818 instantiate_decl_rtl (XEXP (x, 0));
1819 instantiate_decl_rtl (XEXP (x, 1));
1820 return;
1821 }
1822
1823 /* If this is not a MEM, no need to do anything. Similarly if the
1824 address is a constant or a register that is not a virtual register. */
1825 if (!MEM_P (x))
1826 return;
1827
1828 addr = XEXP (x, 0);
1829 if (CONSTANT_P (addr)
1830 || (REG_P (addr)
1831 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
1832 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
1833 return;
1834
1835 instantiate_virtual_regs_in_rtx (&XEXP (x, 0));
1836 }
1837
1838 /* Helper for instantiate_decls called via walk_tree: Process all decls
1839 in the given DECL_VALUE_EXPR. */
1840
1841 static tree
1842 instantiate_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1843 {
1844 tree t = *tp;
1845 if (! EXPR_P (t))
1846 {
1847 *walk_subtrees = 0;
1848 if (DECL_P (t))
1849 {
1850 if (DECL_RTL_SET_P (t))
1851 instantiate_decl_rtl (DECL_RTL (t));
1852 if (TREE_CODE (t) == PARM_DECL && DECL_NAMELESS (t)
1853 && DECL_INCOMING_RTL (t))
1854 instantiate_decl_rtl (DECL_INCOMING_RTL (t));
1855 if ((VAR_P (t) || TREE_CODE (t) == RESULT_DECL)
1856 && DECL_HAS_VALUE_EXPR_P (t))
1857 {
1858 tree v = DECL_VALUE_EXPR (t);
1859 walk_tree (&v, instantiate_expr, NULL, NULL);
1860 }
1861 }
1862 }
1863 return NULL;
1864 }
1865
1866 /* Subroutine of instantiate_decls: Process all decls in the given
1867 BLOCK node and all its subblocks. */
1868
1869 static void
1870 instantiate_decls_1 (tree let)
1871 {
1872 tree t;
1873
1874 for (t = BLOCK_VARS (let); t; t = DECL_CHAIN (t))
1875 {
1876 if (DECL_RTL_SET_P (t))
1877 instantiate_decl_rtl (DECL_RTL (t));
1878 if (VAR_P (t) && DECL_HAS_VALUE_EXPR_P (t))
1879 {
1880 tree v = DECL_VALUE_EXPR (t);
1881 walk_tree (&v, instantiate_expr, NULL, NULL);
1882 }
1883 }
1884
1885 /* Process all subblocks. */
1886 for (t = BLOCK_SUBBLOCKS (let); t; t = BLOCK_CHAIN (t))
1887 instantiate_decls_1 (t);
1888 }
1889
1890 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1891 all virtual registers in their DECL_RTL's. */
1892
1893 static void
1894 instantiate_decls (tree fndecl)
1895 {
1896 tree decl;
1897 unsigned ix;
1898
1899 /* Process all parameters of the function. */
1900 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = DECL_CHAIN (decl))
1901 {
1902 instantiate_decl_rtl (DECL_RTL (decl));
1903 instantiate_decl_rtl (DECL_INCOMING_RTL (decl));
1904 if (DECL_HAS_VALUE_EXPR_P (decl))
1905 {
1906 tree v = DECL_VALUE_EXPR (decl);
1907 walk_tree (&v, instantiate_expr, NULL, NULL);
1908 }
1909 }
1910
1911 if ((decl = DECL_RESULT (fndecl))
1912 && TREE_CODE (decl) == RESULT_DECL)
1913 {
1914 if (DECL_RTL_SET_P (decl))
1915 instantiate_decl_rtl (DECL_RTL (decl));
1916 if (DECL_HAS_VALUE_EXPR_P (decl))
1917 {
1918 tree v = DECL_VALUE_EXPR (decl);
1919 walk_tree (&v, instantiate_expr, NULL, NULL);
1920 }
1921 }
1922
1923 /* Process the saved static chain if it exists. */
1924 decl = DECL_STRUCT_FUNCTION (fndecl)->static_chain_decl;
1925 if (decl && DECL_HAS_VALUE_EXPR_P (decl))
1926 instantiate_decl_rtl (DECL_RTL (DECL_VALUE_EXPR (decl)));
1927
1928 /* Now process all variables defined in the function or its subblocks. */
1929 if (DECL_INITIAL (fndecl))
1930 instantiate_decls_1 (DECL_INITIAL (fndecl));
1931
1932 FOR_EACH_LOCAL_DECL (cfun, ix, decl)
1933 if (DECL_RTL_SET_P (decl))
1934 instantiate_decl_rtl (DECL_RTL (decl));
1935 vec_free (cfun->local_decls);
1936 }
1937
1938 /* Pass through the INSNS of function FNDECL and convert virtual register
1939 references to hard register references. */
1940
1941 static unsigned int
1942 instantiate_virtual_regs (void)
1943 {
1944 rtx_insn *insn;
1945
1946 /* Compute the offsets to use for this function. */
1947 in_arg_offset = FIRST_PARM_OFFSET (current_function_decl);
1948 var_offset = targetm.starting_frame_offset ();
1949 dynamic_offset = STACK_DYNAMIC_OFFSET (current_function_decl);
1950 out_arg_offset = STACK_POINTER_OFFSET;
1951 #ifdef FRAME_POINTER_CFA_OFFSET
1952 cfa_offset = FRAME_POINTER_CFA_OFFSET (current_function_decl);
1953 #else
1954 cfa_offset = ARG_POINTER_CFA_OFFSET (current_function_decl);
1955 #endif
1956
1957 /* Initialize recognition, indicating that volatile is OK. */
1958 init_recog ();
1959
1960 /* Scan through all the insns, instantiating every virtual register still
1961 present. */
1962 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
1963 if (INSN_P (insn))
1964 {
1965 /* These patterns in the instruction stream can never be recognized.
1966 Fortunately, they shouldn't contain virtual registers either. */
1967 if (GET_CODE (PATTERN (insn)) == USE
1968 || GET_CODE (PATTERN (insn)) == CLOBBER
1969 || GET_CODE (PATTERN (insn)) == ASM_INPUT
1970 || DEBUG_MARKER_INSN_P (insn))
1971 continue;
1972 else if (DEBUG_BIND_INSN_P (insn))
1973 instantiate_virtual_regs_in_rtx (INSN_VAR_LOCATION_PTR (insn));
1974 else
1975 instantiate_virtual_regs_in_insn (insn);
1976
1977 if (insn->deleted ())
1978 continue;
1979
1980 instantiate_virtual_regs_in_rtx (&REG_NOTES (insn));
1981
1982 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
1983 if (CALL_P (insn))
1984 instantiate_virtual_regs_in_rtx (&CALL_INSN_FUNCTION_USAGE (insn));
1985 }
1986
1987 /* Instantiate the virtual registers in the DECLs for debugging purposes. */
1988 instantiate_decls (current_function_decl);
1989
1990 targetm.instantiate_decls ();
1991
1992 /* Indicate that, from now on, assign_stack_local should use
1993 frame_pointer_rtx. */
1994 virtuals_instantiated = 1;
1995
1996 return 0;
1997 }
1998
1999 namespace {
2000
2001 const pass_data pass_data_instantiate_virtual_regs =
2002 {
2003 RTL_PASS, /* type */
2004 "vregs", /* name */
2005 OPTGROUP_NONE, /* optinfo_flags */
2006 TV_NONE, /* tv_id */
2007 0, /* properties_required */
2008 0, /* properties_provided */
2009 0, /* properties_destroyed */
2010 0, /* todo_flags_start */
2011 0, /* todo_flags_finish */
2012 };
2013
2014 class pass_instantiate_virtual_regs : public rtl_opt_pass
2015 {
2016 public:
2017 pass_instantiate_virtual_regs (gcc::context *ctxt)
2018 : rtl_opt_pass (pass_data_instantiate_virtual_regs, ctxt)
2019 {}
2020
2021 /* opt_pass methods: */
2022 virtual unsigned int execute (function *)
2023 {
2024 return instantiate_virtual_regs ();
2025 }
2026
2027 }; // class pass_instantiate_virtual_regs
2028
2029 } // anon namespace
2030
2031 rtl_opt_pass *
2032 make_pass_instantiate_virtual_regs (gcc::context *ctxt)
2033 {
2034 return new pass_instantiate_virtual_regs (ctxt);
2035 }
2036
2037 \f
2038 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
2039 This means a type for which function calls must pass an address to the
2040 function or get an address back from the function.
2041 EXP may be a type node or an expression (whose type is tested). */
2042
2043 int
2044 aggregate_value_p (const_tree exp, const_tree fntype)
2045 {
2046 const_tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
2047 int i, regno, nregs;
2048 rtx reg;
2049
2050 if (fntype)
2051 switch (TREE_CODE (fntype))
2052 {
2053 case CALL_EXPR:
2054 {
2055 tree fndecl = get_callee_fndecl (fntype);
2056 if (fndecl)
2057 fntype = TREE_TYPE (fndecl);
2058 else if (CALL_EXPR_FN (fntype))
2059 fntype = TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (fntype)));
2060 else
2061 /* For internal functions, assume nothing needs to be
2062 returned in memory. */
2063 return 0;
2064 }
2065 break;
2066 case FUNCTION_DECL:
2067 fntype = TREE_TYPE (fntype);
2068 break;
2069 case FUNCTION_TYPE:
2070 case METHOD_TYPE:
2071 break;
2072 case IDENTIFIER_NODE:
2073 fntype = NULL_TREE;
2074 break;
2075 default:
2076 /* We don't expect other tree types here. */
2077 gcc_unreachable ();
2078 }
2079
2080 if (VOID_TYPE_P (type))
2081 return 0;
2082
2083 /* If a record should be passed the same as its first (and only) member
2084 don't pass it as an aggregate. */
2085 if (TREE_CODE (type) == RECORD_TYPE && TYPE_TRANSPARENT_AGGR (type))
2086 return aggregate_value_p (first_field (type), fntype);
2087
2088 /* If the front end has decided that this needs to be passed by
2089 reference, do so. */
2090 if ((TREE_CODE (exp) == PARM_DECL || TREE_CODE (exp) == RESULT_DECL)
2091 && DECL_BY_REFERENCE (exp))
2092 return 1;
2093
2094 /* Function types that are TREE_ADDRESSABLE force return in memory. */
2095 if (fntype && TREE_ADDRESSABLE (fntype))
2096 return 1;
2097
2098 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
2099 and thus can't be returned in registers. */
2100 if (TREE_ADDRESSABLE (type))
2101 return 1;
2102
2103 if (TYPE_EMPTY_P (type))
2104 return 0;
2105
2106 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
2107 return 1;
2108
2109 if (targetm.calls.return_in_memory (type, fntype))
2110 return 1;
2111
2112 /* Make sure we have suitable call-clobbered regs to return
2113 the value in; if not, we must return it in memory. */
2114 reg = hard_function_value (type, 0, fntype, 0);
2115
2116 /* If we have something other than a REG (e.g. a PARALLEL), then assume
2117 it is OK. */
2118 if (!REG_P (reg))
2119 return 0;
2120
2121 regno = REGNO (reg);
2122 nregs = hard_regno_nregs (regno, TYPE_MODE (type));
2123 for (i = 0; i < nregs; i++)
2124 if (! call_used_regs[regno + i])
2125 return 1;
2126
2127 return 0;
2128 }
2129 \f
2130 /* Return true if we should assign DECL a pseudo register; false if it
2131 should live on the local stack. */
2132
2133 bool
2134 use_register_for_decl (const_tree decl)
2135 {
2136 if (TREE_CODE (decl) == SSA_NAME)
2137 {
2138 /* We often try to use the SSA_NAME, instead of its underlying
2139 decl, to get type information and guide decisions, to avoid
2140 differences of behavior between anonymous and named
2141 variables, but in this one case we have to go for the actual
2142 variable if there is one. The main reason is that, at least
2143 at -O0, we want to place user variables on the stack, but we
2144 don't mind using pseudos for anonymous or ignored temps.
2145 Should we take the SSA_NAME, we'd conclude all SSA_NAMEs
2146 should go in pseudos, whereas their corresponding variables
2147 might have to go on the stack. So, disregarding the decl
2148 here would negatively impact debug info at -O0, enable
2149 coalescing between SSA_NAMEs that ought to get different
2150 stack/pseudo assignments, and get the incoming argument
2151 processing thoroughly confused by PARM_DECLs expected to live
2152 in stack slots but assigned to pseudos. */
2153 if (!SSA_NAME_VAR (decl))
2154 return TYPE_MODE (TREE_TYPE (decl)) != BLKmode
2155 && !(flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)));
2156
2157 decl = SSA_NAME_VAR (decl);
2158 }
2159
2160 /* Honor volatile. */
2161 if (TREE_SIDE_EFFECTS (decl))
2162 return false;
2163
2164 /* Honor addressability. */
2165 if (TREE_ADDRESSABLE (decl))
2166 return false;
2167
2168 /* RESULT_DECLs are a bit special in that they're assigned without
2169 regard to use_register_for_decl, but we generally only store in
2170 them. If we coalesce their SSA NAMEs, we'd better return a
2171 result that matches the assignment in expand_function_start. */
2172 if (TREE_CODE (decl) == RESULT_DECL)
2173 {
2174 /* If it's not an aggregate, we're going to use a REG or a
2175 PARALLEL containing a REG. */
2176 if (!aggregate_value_p (decl, current_function_decl))
2177 return true;
2178
2179 /* If expand_function_start determines the return value, we'll
2180 use MEM if it's not by reference. */
2181 if (cfun->returns_pcc_struct
2182 || (targetm.calls.struct_value_rtx
2183 (TREE_TYPE (current_function_decl), 1)))
2184 return DECL_BY_REFERENCE (decl);
2185
2186 /* Otherwise, we're taking an extra all.function_result_decl
2187 argument. It's set up in assign_parms_augmented_arg_list,
2188 under the (negated) conditions above, and then it's used to
2189 set up the RESULT_DECL rtl in assign_params, after looping
2190 over all parameters. Now, if the RESULT_DECL is not by
2191 reference, we'll use a MEM either way. */
2192 if (!DECL_BY_REFERENCE (decl))
2193 return false;
2194
2195 /* Otherwise, if RESULT_DECL is DECL_BY_REFERENCE, it will take
2196 the function_result_decl's assignment. Since it's a pointer,
2197 we can short-circuit a number of the tests below, and we must
2198 duplicat e them because we don't have the
2199 function_result_decl to test. */
2200 if (!targetm.calls.allocate_stack_slots_for_args ())
2201 return true;
2202 /* We don't set DECL_IGNORED_P for the function_result_decl. */
2203 if (optimize)
2204 return true;
2205 /* We don't set DECL_REGISTER for the function_result_decl. */
2206 return false;
2207 }
2208
2209 /* Only register-like things go in registers. */
2210 if (DECL_MODE (decl) == BLKmode)
2211 return false;
2212
2213 /* If -ffloat-store specified, don't put explicit float variables
2214 into registers. */
2215 /* ??? This should be checked after DECL_ARTIFICIAL, but tree-ssa
2216 propagates values across these stores, and it probably shouldn't. */
2217 if (flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)))
2218 return false;
2219
2220 if (!targetm.calls.allocate_stack_slots_for_args ())
2221 return true;
2222
2223 /* If we're not interested in tracking debugging information for
2224 this decl, then we can certainly put it in a register. */
2225 if (DECL_IGNORED_P (decl))
2226 return true;
2227
2228 if (optimize)
2229 return true;
2230
2231 if (!DECL_REGISTER (decl))
2232 return false;
2233
2234 /* When not optimizing, disregard register keyword for types that
2235 could have methods, otherwise the methods won't be callable from
2236 the debugger. */
2237 if (RECORD_OR_UNION_TYPE_P (TREE_TYPE (decl)))
2238 return false;
2239
2240 return true;
2241 }
2242
2243 /* Structures to communicate between the subroutines of assign_parms.
2244 The first holds data persistent across all parameters, the second
2245 is cleared out for each parameter. */
2246
2247 struct assign_parm_data_all
2248 {
2249 /* When INIT_CUMULATIVE_ARGS gets revamped, allocating CUMULATIVE_ARGS
2250 should become a job of the target or otherwise encapsulated. */
2251 CUMULATIVE_ARGS args_so_far_v;
2252 cumulative_args_t args_so_far;
2253 struct args_size stack_args_size;
2254 tree function_result_decl;
2255 tree orig_fnargs;
2256 rtx_insn *first_conversion_insn;
2257 rtx_insn *last_conversion_insn;
2258 HOST_WIDE_INT pretend_args_size;
2259 HOST_WIDE_INT extra_pretend_bytes;
2260 int reg_parm_stack_space;
2261 };
2262
2263 struct assign_parm_data_one
2264 {
2265 tree nominal_type;
2266 tree passed_type;
2267 rtx entry_parm;
2268 rtx stack_parm;
2269 machine_mode nominal_mode;
2270 machine_mode passed_mode;
2271 machine_mode promoted_mode;
2272 struct locate_and_pad_arg_data locate;
2273 int partial;
2274 BOOL_BITFIELD named_arg : 1;
2275 BOOL_BITFIELD passed_pointer : 1;
2276 BOOL_BITFIELD on_stack : 1;
2277 BOOL_BITFIELD loaded_in_reg : 1;
2278 };
2279
2280 /* A subroutine of assign_parms. Initialize ALL. */
2281
2282 static void
2283 assign_parms_initialize_all (struct assign_parm_data_all *all)
2284 {
2285 tree fntype ATTRIBUTE_UNUSED;
2286
2287 memset (all, 0, sizeof (*all));
2288
2289 fntype = TREE_TYPE (current_function_decl);
2290
2291 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
2292 INIT_CUMULATIVE_INCOMING_ARGS (all->args_so_far_v, fntype, NULL_RTX);
2293 #else
2294 INIT_CUMULATIVE_ARGS (all->args_so_far_v, fntype, NULL_RTX,
2295 current_function_decl, -1);
2296 #endif
2297 all->args_so_far = pack_cumulative_args (&all->args_so_far_v);
2298
2299 #ifdef INCOMING_REG_PARM_STACK_SPACE
2300 all->reg_parm_stack_space
2301 = INCOMING_REG_PARM_STACK_SPACE (current_function_decl);
2302 #endif
2303 }
2304
2305 /* If ARGS contains entries with complex types, split the entry into two
2306 entries of the component type. Return a new list of substitutions are
2307 needed, else the old list. */
2308
2309 static void
2310 split_complex_args (vec<tree> *args)
2311 {
2312 unsigned i;
2313 tree p;
2314
2315 FOR_EACH_VEC_ELT (*args, i, p)
2316 {
2317 tree type = TREE_TYPE (p);
2318 if (TREE_CODE (type) == COMPLEX_TYPE
2319 && targetm.calls.split_complex_arg (type))
2320 {
2321 tree decl;
2322 tree subtype = TREE_TYPE (type);
2323 bool addressable = TREE_ADDRESSABLE (p);
2324
2325 /* Rewrite the PARM_DECL's type with its component. */
2326 p = copy_node (p);
2327 TREE_TYPE (p) = subtype;
2328 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
2329 SET_DECL_MODE (p, VOIDmode);
2330 DECL_SIZE (p) = NULL;
2331 DECL_SIZE_UNIT (p) = NULL;
2332 /* If this arg must go in memory, put it in a pseudo here.
2333 We can't allow it to go in memory as per normal parms,
2334 because the usual place might not have the imag part
2335 adjacent to the real part. */
2336 DECL_ARTIFICIAL (p) = addressable;
2337 DECL_IGNORED_P (p) = addressable;
2338 TREE_ADDRESSABLE (p) = 0;
2339 layout_decl (p, 0);
2340 (*args)[i] = p;
2341
2342 /* Build a second synthetic decl. */
2343 decl = build_decl (EXPR_LOCATION (p),
2344 PARM_DECL, NULL_TREE, subtype);
2345 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
2346 DECL_ARTIFICIAL (decl) = addressable;
2347 DECL_IGNORED_P (decl) = addressable;
2348 layout_decl (decl, 0);
2349 args->safe_insert (++i, decl);
2350 }
2351 }
2352 }
2353
2354 /* A subroutine of assign_parms. Adjust the parameter list to incorporate
2355 the hidden struct return argument, and (abi willing) complex args.
2356 Return the new parameter list. */
2357
2358 static vec<tree>
2359 assign_parms_augmented_arg_list (struct assign_parm_data_all *all)
2360 {
2361 tree fndecl = current_function_decl;
2362 tree fntype = TREE_TYPE (fndecl);
2363 vec<tree> fnargs = vNULL;
2364 tree arg;
2365
2366 for (arg = DECL_ARGUMENTS (fndecl); arg; arg = DECL_CHAIN (arg))
2367 fnargs.safe_push (arg);
2368
2369 all->orig_fnargs = DECL_ARGUMENTS (fndecl);
2370
2371 /* If struct value address is treated as the first argument, make it so. */
2372 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
2373 && ! cfun->returns_pcc_struct
2374 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
2375 {
2376 tree type = build_pointer_type (TREE_TYPE (fntype));
2377 tree decl;
2378
2379 decl = build_decl (DECL_SOURCE_LOCATION (fndecl),
2380 PARM_DECL, get_identifier (".result_ptr"), type);
2381 DECL_ARG_TYPE (decl) = type;
2382 DECL_ARTIFICIAL (decl) = 1;
2383 DECL_NAMELESS (decl) = 1;
2384 TREE_CONSTANT (decl) = 1;
2385 /* We don't set DECL_IGNORED_P or DECL_REGISTER here. If this
2386 changes, the end of the RESULT_DECL handling block in
2387 use_register_for_decl must be adjusted to match. */
2388
2389 DECL_CHAIN (decl) = all->orig_fnargs;
2390 all->orig_fnargs = decl;
2391 fnargs.safe_insert (0, decl);
2392
2393 all->function_result_decl = decl;
2394 }
2395
2396 /* If the target wants to split complex arguments into scalars, do so. */
2397 if (targetm.calls.split_complex_arg)
2398 split_complex_args (&fnargs);
2399
2400 return fnargs;
2401 }
2402
2403 /* A subroutine of assign_parms. Examine PARM and pull out type and mode
2404 data for the parameter. Incorporate ABI specifics such as pass-by-
2405 reference and type promotion. */
2406
2407 static void
2408 assign_parm_find_data_types (struct assign_parm_data_all *all, tree parm,
2409 struct assign_parm_data_one *data)
2410 {
2411 tree nominal_type, passed_type;
2412 machine_mode nominal_mode, passed_mode, promoted_mode;
2413 int unsignedp;
2414
2415 memset (data, 0, sizeof (*data));
2416
2417 /* NAMED_ARG is a misnomer. We really mean 'non-variadic'. */
2418 if (!cfun->stdarg)
2419 data->named_arg = 1; /* No variadic parms. */
2420 else if (DECL_CHAIN (parm))
2421 data->named_arg = 1; /* Not the last non-variadic parm. */
2422 else if (targetm.calls.strict_argument_naming (all->args_so_far))
2423 data->named_arg = 1; /* Only variadic ones are unnamed. */
2424 else
2425 data->named_arg = 0; /* Treat as variadic. */
2426
2427 nominal_type = TREE_TYPE (parm);
2428 passed_type = DECL_ARG_TYPE (parm);
2429
2430 /* Look out for errors propagating this far. Also, if the parameter's
2431 type is void then its value doesn't matter. */
2432 if (TREE_TYPE (parm) == error_mark_node
2433 /* This can happen after weird syntax errors
2434 or if an enum type is defined among the parms. */
2435 || TREE_CODE (parm) != PARM_DECL
2436 || passed_type == NULL
2437 || VOID_TYPE_P (nominal_type))
2438 {
2439 nominal_type = passed_type = void_type_node;
2440 nominal_mode = passed_mode = promoted_mode = VOIDmode;
2441 goto egress;
2442 }
2443
2444 /* Find mode of arg as it is passed, and mode of arg as it should be
2445 during execution of this function. */
2446 passed_mode = TYPE_MODE (passed_type);
2447 nominal_mode = TYPE_MODE (nominal_type);
2448
2449 /* If the parm is to be passed as a transparent union or record, use the
2450 type of the first field for the tests below. We have already verified
2451 that the modes are the same. */
2452 if ((TREE_CODE (passed_type) == UNION_TYPE
2453 || TREE_CODE (passed_type) == RECORD_TYPE)
2454 && TYPE_TRANSPARENT_AGGR (passed_type))
2455 passed_type = TREE_TYPE (first_field (passed_type));
2456
2457 /* See if this arg was passed by invisible reference. */
2458 if (pass_by_reference (&all->args_so_far_v, passed_mode,
2459 passed_type, data->named_arg))
2460 {
2461 passed_type = nominal_type = build_pointer_type (passed_type);
2462 data->passed_pointer = true;
2463 passed_mode = nominal_mode = TYPE_MODE (nominal_type);
2464 }
2465
2466 /* Find mode as it is passed by the ABI. */
2467 unsignedp = TYPE_UNSIGNED (passed_type);
2468 promoted_mode = promote_function_mode (passed_type, passed_mode, &unsignedp,
2469 TREE_TYPE (current_function_decl), 0);
2470
2471 egress:
2472 data->nominal_type = nominal_type;
2473 data->passed_type = passed_type;
2474 data->nominal_mode = nominal_mode;
2475 data->passed_mode = passed_mode;
2476 data->promoted_mode = promoted_mode;
2477 }
2478
2479 /* A subroutine of assign_parms. Invoke setup_incoming_varargs. */
2480
2481 static void
2482 assign_parms_setup_varargs (struct assign_parm_data_all *all,
2483 struct assign_parm_data_one *data, bool no_rtl)
2484 {
2485 int varargs_pretend_bytes = 0;
2486
2487 targetm.calls.setup_incoming_varargs (all->args_so_far,
2488 data->promoted_mode,
2489 data->passed_type,
2490 &varargs_pretend_bytes, no_rtl);
2491
2492 /* If the back-end has requested extra stack space, record how much is
2493 needed. Do not change pretend_args_size otherwise since it may be
2494 nonzero from an earlier partial argument. */
2495 if (varargs_pretend_bytes > 0)
2496 all->pretend_args_size = varargs_pretend_bytes;
2497 }
2498
2499 /* A subroutine of assign_parms. Set DATA->ENTRY_PARM corresponding to
2500 the incoming location of the current parameter. */
2501
2502 static void
2503 assign_parm_find_entry_rtl (struct assign_parm_data_all *all,
2504 struct assign_parm_data_one *data)
2505 {
2506 HOST_WIDE_INT pretend_bytes = 0;
2507 rtx entry_parm;
2508 bool in_regs;
2509
2510 if (data->promoted_mode == VOIDmode)
2511 {
2512 data->entry_parm = data->stack_parm = const0_rtx;
2513 return;
2514 }
2515
2516 targetm.calls.warn_parameter_passing_abi (all->args_so_far,
2517 data->passed_type);
2518
2519 entry_parm = targetm.calls.function_incoming_arg (all->args_so_far,
2520 data->promoted_mode,
2521 data->passed_type,
2522 data->named_arg);
2523
2524 if (entry_parm == 0)
2525 data->promoted_mode = data->passed_mode;
2526
2527 /* Determine parm's home in the stack, in case it arrives in the stack
2528 or we should pretend it did. Compute the stack position and rtx where
2529 the argument arrives and its size.
2530
2531 There is one complexity here: If this was a parameter that would
2532 have been passed in registers, but wasn't only because it is
2533 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2534 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2535 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of 0
2536 as it was the previous time. */
2537 in_regs = (entry_parm != 0);
2538 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2539 in_regs = true;
2540 #endif
2541 if (!in_regs && !data->named_arg)
2542 {
2543 if (targetm.calls.pretend_outgoing_varargs_named (all->args_so_far))
2544 {
2545 rtx tem;
2546 tem = targetm.calls.function_incoming_arg (all->args_so_far,
2547 data->promoted_mode,
2548 data->passed_type, true);
2549 in_regs = tem != NULL;
2550 }
2551 }
2552
2553 /* If this parameter was passed both in registers and in the stack, use
2554 the copy on the stack. */
2555 if (targetm.calls.must_pass_in_stack (data->promoted_mode,
2556 data->passed_type))
2557 entry_parm = 0;
2558
2559 if (entry_parm)
2560 {
2561 int partial;
2562
2563 partial = targetm.calls.arg_partial_bytes (all->args_so_far,
2564 data->promoted_mode,
2565 data->passed_type,
2566 data->named_arg);
2567 data->partial = partial;
2568
2569 /* The caller might already have allocated stack space for the
2570 register parameters. */
2571 if (partial != 0 && all->reg_parm_stack_space == 0)
2572 {
2573 /* Part of this argument is passed in registers and part
2574 is passed on the stack. Ask the prologue code to extend
2575 the stack part so that we can recreate the full value.
2576
2577 PRETEND_BYTES is the size of the registers we need to store.
2578 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
2579 stack space that the prologue should allocate.
2580
2581 Internally, gcc assumes that the argument pointer is aligned
2582 to STACK_BOUNDARY bits. This is used both for alignment
2583 optimizations (see init_emit) and to locate arguments that are
2584 aligned to more than PARM_BOUNDARY bits. We must preserve this
2585 invariant by rounding CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to
2586 a stack boundary. */
2587
2588 /* We assume at most one partial arg, and it must be the first
2589 argument on the stack. */
2590 gcc_assert (!all->extra_pretend_bytes && !all->pretend_args_size);
2591
2592 pretend_bytes = partial;
2593 all->pretend_args_size = CEIL_ROUND (pretend_bytes, STACK_BYTES);
2594
2595 /* We want to align relative to the actual stack pointer, so
2596 don't include this in the stack size until later. */
2597 all->extra_pretend_bytes = all->pretend_args_size;
2598 }
2599 }
2600
2601 locate_and_pad_parm (data->promoted_mode, data->passed_type, in_regs,
2602 all->reg_parm_stack_space,
2603 entry_parm ? data->partial : 0, current_function_decl,
2604 &all->stack_args_size, &data->locate);
2605
2606 /* Update parm_stack_boundary if this parameter is passed in the
2607 stack. */
2608 if (!in_regs && crtl->parm_stack_boundary < data->locate.boundary)
2609 crtl->parm_stack_boundary = data->locate.boundary;
2610
2611 /* Adjust offsets to include the pretend args. */
2612 pretend_bytes = all->extra_pretend_bytes - pretend_bytes;
2613 data->locate.slot_offset.constant += pretend_bytes;
2614 data->locate.offset.constant += pretend_bytes;
2615
2616 data->entry_parm = entry_parm;
2617 }
2618
2619 /* A subroutine of assign_parms. If there is actually space on the stack
2620 for this parm, count it in stack_args_size and return true. */
2621
2622 static bool
2623 assign_parm_is_stack_parm (struct assign_parm_data_all *all,
2624 struct assign_parm_data_one *data)
2625 {
2626 /* Trivially true if we've no incoming register. */
2627 if (data->entry_parm == NULL)
2628 ;
2629 /* Also true if we're partially in registers and partially not,
2630 since we've arranged to drop the entire argument on the stack. */
2631 else if (data->partial != 0)
2632 ;
2633 /* Also true if the target says that it's passed in both registers
2634 and on the stack. */
2635 else if (GET_CODE (data->entry_parm) == PARALLEL
2636 && XEXP (XVECEXP (data->entry_parm, 0, 0), 0) == NULL_RTX)
2637 ;
2638 /* Also true if the target says that there's stack allocated for
2639 all register parameters. */
2640 else if (all->reg_parm_stack_space > 0)
2641 ;
2642 /* Otherwise, no, this parameter has no ABI defined stack slot. */
2643 else
2644 return false;
2645
2646 all->stack_args_size.constant += data->locate.size.constant;
2647 if (data->locate.size.var)
2648 ADD_PARM_SIZE (all->stack_args_size, data->locate.size.var);
2649
2650 return true;
2651 }
2652
2653 /* A subroutine of assign_parms. Given that this parameter is allocated
2654 stack space by the ABI, find it. */
2655
2656 static void
2657 assign_parm_find_stack_rtl (tree parm, struct assign_parm_data_one *data)
2658 {
2659 rtx offset_rtx, stack_parm;
2660 unsigned int align, boundary;
2661
2662 /* If we're passing this arg using a reg, make its stack home the
2663 aligned stack slot. */
2664 if (data->entry_parm)
2665 offset_rtx = ARGS_SIZE_RTX (data->locate.slot_offset);
2666 else
2667 offset_rtx = ARGS_SIZE_RTX (data->locate.offset);
2668
2669 stack_parm = crtl->args.internal_arg_pointer;
2670 if (offset_rtx != const0_rtx)
2671 stack_parm = gen_rtx_PLUS (Pmode, stack_parm, offset_rtx);
2672 stack_parm = gen_rtx_MEM (data->promoted_mode, stack_parm);
2673
2674 if (!data->passed_pointer)
2675 {
2676 set_mem_attributes (stack_parm, parm, 1);
2677 /* set_mem_attributes could set MEM_SIZE to the passed mode's size,
2678 while promoted mode's size is needed. */
2679 if (data->promoted_mode != BLKmode
2680 && data->promoted_mode != DECL_MODE (parm))
2681 {
2682 set_mem_size (stack_parm, GET_MODE_SIZE (data->promoted_mode));
2683 if (MEM_EXPR (stack_parm) && MEM_OFFSET_KNOWN_P (stack_parm))
2684 {
2685 poly_int64 offset = subreg_lowpart_offset (DECL_MODE (parm),
2686 data->promoted_mode);
2687 if (maybe_ne (offset, 0))
2688 set_mem_offset (stack_parm, MEM_OFFSET (stack_parm) - offset);
2689 }
2690 }
2691 }
2692
2693 boundary = data->locate.boundary;
2694 align = BITS_PER_UNIT;
2695
2696 /* If we're padding upward, we know that the alignment of the slot
2697 is TARGET_FUNCTION_ARG_BOUNDARY. If we're using slot_offset, we're
2698 intentionally forcing upward padding. Otherwise we have to come
2699 up with a guess at the alignment based on OFFSET_RTX. */
2700 poly_int64 offset;
2701 if (data->locate.where_pad != PAD_DOWNWARD || data->entry_parm)
2702 align = boundary;
2703 else if (poly_int_rtx_p (offset_rtx, &offset))
2704 {
2705 align = least_bit_hwi (boundary);
2706 unsigned int offset_align = known_alignment (offset) * BITS_PER_UNIT;
2707 if (offset_align != 0)
2708 align = MIN (align, offset_align);
2709 }
2710 set_mem_align (stack_parm, align);
2711
2712 if (data->entry_parm)
2713 set_reg_attrs_for_parm (data->entry_parm, stack_parm);
2714
2715 data->stack_parm = stack_parm;
2716 }
2717
2718 /* A subroutine of assign_parms. Adjust DATA->ENTRY_RTL such that it's
2719 always valid and contiguous. */
2720
2721 static void
2722 assign_parm_adjust_entry_rtl (struct assign_parm_data_one *data)
2723 {
2724 rtx entry_parm = data->entry_parm;
2725 rtx stack_parm = data->stack_parm;
2726
2727 /* If this parm was passed part in regs and part in memory, pretend it
2728 arrived entirely in memory by pushing the register-part onto the stack.
2729 In the special case of a DImode or DFmode that is split, we could put
2730 it together in a pseudoreg directly, but for now that's not worth
2731 bothering with. */
2732 if (data->partial != 0)
2733 {
2734 /* Handle calls that pass values in multiple non-contiguous
2735 locations. The Irix 6 ABI has examples of this. */
2736 if (GET_CODE (entry_parm) == PARALLEL)
2737 emit_group_store (validize_mem (copy_rtx (stack_parm)), entry_parm,
2738 data->passed_type,
2739 int_size_in_bytes (data->passed_type));
2740 else
2741 {
2742 gcc_assert (data->partial % UNITS_PER_WORD == 0);
2743 move_block_from_reg (REGNO (entry_parm),
2744 validize_mem (copy_rtx (stack_parm)),
2745 data->partial / UNITS_PER_WORD);
2746 }
2747
2748 entry_parm = stack_parm;
2749 }
2750
2751 /* If we didn't decide this parm came in a register, by default it came
2752 on the stack. */
2753 else if (entry_parm == NULL)
2754 entry_parm = stack_parm;
2755
2756 /* When an argument is passed in multiple locations, we can't make use
2757 of this information, but we can save some copying if the whole argument
2758 is passed in a single register. */
2759 else if (GET_CODE (entry_parm) == PARALLEL
2760 && data->nominal_mode != BLKmode
2761 && data->passed_mode != BLKmode)
2762 {
2763 size_t i, len = XVECLEN (entry_parm, 0);
2764
2765 for (i = 0; i < len; i++)
2766 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
2767 && REG_P (XEXP (XVECEXP (entry_parm, 0, i), 0))
2768 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
2769 == data->passed_mode)
2770 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
2771 {
2772 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
2773 break;
2774 }
2775 }
2776
2777 data->entry_parm = entry_parm;
2778 }
2779
2780 /* A subroutine of assign_parms. Reconstitute any values which were
2781 passed in multiple registers and would fit in a single register. */
2782
2783 static void
2784 assign_parm_remove_parallels (struct assign_parm_data_one *data)
2785 {
2786 rtx entry_parm = data->entry_parm;
2787
2788 /* Convert the PARALLEL to a REG of the same mode as the parallel.
2789 This can be done with register operations rather than on the
2790 stack, even if we will store the reconstituted parameter on the
2791 stack later. */
2792 if (GET_CODE (entry_parm) == PARALLEL && GET_MODE (entry_parm) != BLKmode)
2793 {
2794 rtx parmreg = gen_reg_rtx (GET_MODE (entry_parm));
2795 emit_group_store (parmreg, entry_parm, data->passed_type,
2796 GET_MODE_SIZE (GET_MODE (entry_parm)));
2797 entry_parm = parmreg;
2798 }
2799
2800 data->entry_parm = entry_parm;
2801 }
2802
2803 /* A subroutine of assign_parms. Adjust DATA->STACK_RTL such that it's
2804 always valid and properly aligned. */
2805
2806 static void
2807 assign_parm_adjust_stack_rtl (struct assign_parm_data_one *data)
2808 {
2809 rtx stack_parm = data->stack_parm;
2810
2811 /* If we can't trust the parm stack slot to be aligned enough for its
2812 ultimate type, don't use that slot after entry. We'll make another
2813 stack slot, if we need one. */
2814 if (stack_parm
2815 && ((STRICT_ALIGNMENT
2816 && GET_MODE_ALIGNMENT (data->nominal_mode) > MEM_ALIGN (stack_parm))
2817 || (data->nominal_type
2818 && TYPE_ALIGN (data->nominal_type) > MEM_ALIGN (stack_parm)
2819 && MEM_ALIGN (stack_parm) < PREFERRED_STACK_BOUNDARY)))
2820 stack_parm = NULL;
2821
2822 /* If parm was passed in memory, and we need to convert it on entry,
2823 don't store it back in that same slot. */
2824 else if (data->entry_parm == stack_parm
2825 && data->nominal_mode != BLKmode
2826 && data->nominal_mode != data->passed_mode)
2827 stack_parm = NULL;
2828
2829 /* If stack protection is in effect for this function, don't leave any
2830 pointers in their passed stack slots. */
2831 else if (crtl->stack_protect_guard
2832 && (flag_stack_protect == 2
2833 || data->passed_pointer
2834 || POINTER_TYPE_P (data->nominal_type)))
2835 stack_parm = NULL;
2836
2837 data->stack_parm = stack_parm;
2838 }
2839
2840 /* A subroutine of assign_parms. Return true if the current parameter
2841 should be stored as a BLKmode in the current frame. */
2842
2843 static bool
2844 assign_parm_setup_block_p (struct assign_parm_data_one *data)
2845 {
2846 if (data->nominal_mode == BLKmode)
2847 return true;
2848 if (GET_MODE (data->entry_parm) == BLKmode)
2849 return true;
2850
2851 #ifdef BLOCK_REG_PADDING
2852 /* Only assign_parm_setup_block knows how to deal with register arguments
2853 that are padded at the least significant end. */
2854 if (REG_P (data->entry_parm)
2855 && known_lt (GET_MODE_SIZE (data->promoted_mode), UNITS_PER_WORD)
2856 && (BLOCK_REG_PADDING (data->passed_mode, data->passed_type, 1)
2857 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
2858 return true;
2859 #endif
2860
2861 return false;
2862 }
2863
2864 /* A subroutine of assign_parms. Arrange for the parameter to be
2865 present and valid in DATA->STACK_RTL. */
2866
2867 static void
2868 assign_parm_setup_block (struct assign_parm_data_all *all,
2869 tree parm, struct assign_parm_data_one *data)
2870 {
2871 rtx entry_parm = data->entry_parm;
2872 rtx stack_parm = data->stack_parm;
2873 rtx target_reg = NULL_RTX;
2874 bool in_conversion_seq = false;
2875 HOST_WIDE_INT size;
2876 HOST_WIDE_INT size_stored;
2877
2878 if (GET_CODE (entry_parm) == PARALLEL)
2879 entry_parm = emit_group_move_into_temps (entry_parm);
2880
2881 /* If we want the parameter in a pseudo, don't use a stack slot. */
2882 if (is_gimple_reg (parm) && use_register_for_decl (parm))
2883 {
2884 tree def = ssa_default_def (cfun, parm);
2885 gcc_assert (def);
2886 machine_mode mode = promote_ssa_mode (def, NULL);
2887 rtx reg = gen_reg_rtx (mode);
2888 if (GET_CODE (reg) != CONCAT)
2889 stack_parm = reg;
2890 else
2891 {
2892 target_reg = reg;
2893 /* Avoid allocating a stack slot, if there isn't one
2894 preallocated by the ABI. It might seem like we should
2895 always prefer a pseudo, but converting between
2896 floating-point and integer modes goes through the stack
2897 on various machines, so it's better to use the reserved
2898 stack slot than to risk wasting it and allocating more
2899 for the conversion. */
2900 if (stack_parm == NULL_RTX)
2901 {
2902 int save = generating_concat_p;
2903 generating_concat_p = 0;
2904 stack_parm = gen_reg_rtx (mode);
2905 generating_concat_p = save;
2906 }
2907 }
2908 data->stack_parm = NULL;
2909 }
2910
2911 size = int_size_in_bytes (data->passed_type);
2912 size_stored = CEIL_ROUND (size, UNITS_PER_WORD);
2913 if (stack_parm == 0)
2914 {
2915 HOST_WIDE_INT parm_align
2916 = (STRICT_ALIGNMENT
2917 ? MAX (DECL_ALIGN (parm), BITS_PER_WORD) : DECL_ALIGN (parm));
2918
2919 SET_DECL_ALIGN (parm, parm_align);
2920 if (DECL_ALIGN (parm) > MAX_SUPPORTED_STACK_ALIGNMENT)
2921 {
2922 rtx allocsize = gen_int_mode (size_stored, Pmode);
2923 get_dynamic_stack_size (&allocsize, 0, DECL_ALIGN (parm), NULL);
2924 stack_parm = assign_stack_local (BLKmode, UINTVAL (allocsize),
2925 MAX_SUPPORTED_STACK_ALIGNMENT);
2926 rtx addr = align_dynamic_address (XEXP (stack_parm, 0),
2927 DECL_ALIGN (parm));
2928 mark_reg_pointer (addr, DECL_ALIGN (parm));
2929 stack_parm = gen_rtx_MEM (GET_MODE (stack_parm), addr);
2930 MEM_NOTRAP_P (stack_parm) = 1;
2931 }
2932 else
2933 stack_parm = assign_stack_local (BLKmode, size_stored,
2934 DECL_ALIGN (parm));
2935 if (known_eq (GET_MODE_SIZE (GET_MODE (entry_parm)), size))
2936 PUT_MODE (stack_parm, GET_MODE (entry_parm));
2937 set_mem_attributes (stack_parm, parm, 1);
2938 }
2939
2940 /* If a BLKmode arrives in registers, copy it to a stack slot. Handle
2941 calls that pass values in multiple non-contiguous locations. */
2942 if (REG_P (entry_parm) || GET_CODE (entry_parm) == PARALLEL)
2943 {
2944 rtx mem;
2945
2946 /* Note that we will be storing an integral number of words.
2947 So we have to be careful to ensure that we allocate an
2948 integral number of words. We do this above when we call
2949 assign_stack_local if space was not allocated in the argument
2950 list. If it was, this will not work if PARM_BOUNDARY is not
2951 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2952 if it becomes a problem. Exception is when BLKmode arrives
2953 with arguments not conforming to word_mode. */
2954
2955 if (data->stack_parm == 0)
2956 ;
2957 else if (GET_CODE (entry_parm) == PARALLEL)
2958 ;
2959 else
2960 gcc_assert (!size || !(PARM_BOUNDARY % BITS_PER_WORD));
2961
2962 mem = validize_mem (copy_rtx (stack_parm));
2963
2964 /* Handle values in multiple non-contiguous locations. */
2965 if (GET_CODE (entry_parm) == PARALLEL && !MEM_P (mem))
2966 emit_group_store (mem, entry_parm, data->passed_type, size);
2967 else if (GET_CODE (entry_parm) == PARALLEL)
2968 {
2969 push_to_sequence2 (all->first_conversion_insn,
2970 all->last_conversion_insn);
2971 emit_group_store (mem, entry_parm, data->passed_type, size);
2972 all->first_conversion_insn = get_insns ();
2973 all->last_conversion_insn = get_last_insn ();
2974 end_sequence ();
2975 in_conversion_seq = true;
2976 }
2977
2978 else if (size == 0)
2979 ;
2980
2981 /* If SIZE is that of a mode no bigger than a word, just use
2982 that mode's store operation. */
2983 else if (size <= UNITS_PER_WORD)
2984 {
2985 unsigned int bits = size * BITS_PER_UNIT;
2986 machine_mode mode = int_mode_for_size (bits, 0).else_blk ();
2987
2988 if (mode != BLKmode
2989 #ifdef BLOCK_REG_PADDING
2990 && (size == UNITS_PER_WORD
2991 || (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2992 != (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
2993 #endif
2994 )
2995 {
2996 rtx reg;
2997
2998 /* We are really truncating a word_mode value containing
2999 SIZE bytes into a value of mode MODE. If such an
3000 operation requires no actual instructions, we can refer
3001 to the value directly in mode MODE, otherwise we must
3002 start with the register in word_mode and explicitly
3003 convert it. */
3004 if (targetm.truly_noop_truncation (size * BITS_PER_UNIT,
3005 BITS_PER_WORD))
3006 reg = gen_rtx_REG (mode, REGNO (entry_parm));
3007 else
3008 {
3009 reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
3010 reg = convert_to_mode (mode, copy_to_reg (reg), 1);
3011 }
3012 emit_move_insn (change_address (mem, mode, 0), reg);
3013 }
3014
3015 #ifdef BLOCK_REG_PADDING
3016 /* Storing the register in memory as a full word, as
3017 move_block_from_reg below would do, and then using the
3018 MEM in a smaller mode, has the effect of shifting right
3019 if BYTES_BIG_ENDIAN. If we're bypassing memory, the
3020 shifting must be explicit. */
3021 else if (!MEM_P (mem))
3022 {
3023 rtx x;
3024
3025 /* If the assert below fails, we should have taken the
3026 mode != BLKmode path above, unless we have downward
3027 padding of smaller-than-word arguments on a machine
3028 with little-endian bytes, which would likely require
3029 additional changes to work correctly. */
3030 gcc_checking_assert (BYTES_BIG_ENDIAN
3031 && (BLOCK_REG_PADDING (mode,
3032 data->passed_type, 1)
3033 == PAD_UPWARD));
3034
3035 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
3036
3037 x = gen_rtx_REG (word_mode, REGNO (entry_parm));
3038 x = expand_shift (RSHIFT_EXPR, word_mode, x, by,
3039 NULL_RTX, 1);
3040 x = force_reg (word_mode, x);
3041 x = gen_lowpart_SUBREG (GET_MODE (mem), x);
3042
3043 emit_move_insn (mem, x);
3044 }
3045 #endif
3046
3047 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
3048 machine must be aligned to the left before storing
3049 to memory. Note that the previous test doesn't
3050 handle all cases (e.g. SIZE == 3). */
3051 else if (size != UNITS_PER_WORD
3052 #ifdef BLOCK_REG_PADDING
3053 && (BLOCK_REG_PADDING (mode, data->passed_type, 1)
3054 == PAD_DOWNWARD)
3055 #else
3056 && BYTES_BIG_ENDIAN
3057 #endif
3058 )
3059 {
3060 rtx tem, x;
3061 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
3062 rtx reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
3063
3064 x = expand_shift (LSHIFT_EXPR, word_mode, reg, by, NULL_RTX, 1);
3065 tem = change_address (mem, word_mode, 0);
3066 emit_move_insn (tem, x);
3067 }
3068 else
3069 move_block_from_reg (REGNO (entry_parm), mem,
3070 size_stored / UNITS_PER_WORD);
3071 }
3072 else if (!MEM_P (mem))
3073 {
3074 gcc_checking_assert (size > UNITS_PER_WORD);
3075 #ifdef BLOCK_REG_PADDING
3076 gcc_checking_assert (BLOCK_REG_PADDING (GET_MODE (mem),
3077 data->passed_type, 0)
3078 == PAD_UPWARD);
3079 #endif
3080 emit_move_insn (mem, entry_parm);
3081 }
3082 else
3083 move_block_from_reg (REGNO (entry_parm), mem,
3084 size_stored / UNITS_PER_WORD);
3085 }
3086 else if (data->stack_parm == 0)
3087 {
3088 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3089 emit_block_move (stack_parm, data->entry_parm, GEN_INT (size),
3090 BLOCK_OP_NORMAL);
3091 all->first_conversion_insn = get_insns ();
3092 all->last_conversion_insn = get_last_insn ();
3093 end_sequence ();
3094 in_conversion_seq = true;
3095 }
3096
3097 if (target_reg)
3098 {
3099 if (!in_conversion_seq)
3100 emit_move_insn (target_reg, stack_parm);
3101 else
3102 {
3103 push_to_sequence2 (all->first_conversion_insn,
3104 all->last_conversion_insn);
3105 emit_move_insn (target_reg, stack_parm);
3106 all->first_conversion_insn = get_insns ();
3107 all->last_conversion_insn = get_last_insn ();
3108 end_sequence ();
3109 }
3110 stack_parm = target_reg;
3111 }
3112
3113 data->stack_parm = stack_parm;
3114 set_parm_rtl (parm, stack_parm);
3115 }
3116
3117 /* A subroutine of assign_parms. Allocate a pseudo to hold the current
3118 parameter. Get it there. Perform all ABI specified conversions. */
3119
3120 static void
3121 assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm,
3122 struct assign_parm_data_one *data)
3123 {
3124 rtx parmreg, validated_mem;
3125 rtx equiv_stack_parm;
3126 machine_mode promoted_nominal_mode;
3127 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (parm));
3128 bool did_conversion = false;
3129 bool need_conversion, moved;
3130 rtx rtl;
3131
3132 /* Store the parm in a pseudoregister during the function, but we may
3133 need to do it in a wider mode. Using 2 here makes the result
3134 consistent with promote_decl_mode and thus expand_expr_real_1. */
3135 promoted_nominal_mode
3136 = promote_function_mode (data->nominal_type, data->nominal_mode, &unsignedp,
3137 TREE_TYPE (current_function_decl), 2);
3138
3139 parmreg = gen_reg_rtx (promoted_nominal_mode);
3140 if (!DECL_ARTIFICIAL (parm))
3141 mark_user_reg (parmreg);
3142
3143 /* If this was an item that we received a pointer to,
3144 set rtl appropriately. */
3145 if (data->passed_pointer)
3146 {
3147 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data->passed_type)), parmreg);
3148 set_mem_attributes (rtl, parm, 1);
3149 }
3150 else
3151 rtl = parmreg;
3152
3153 assign_parm_remove_parallels (data);
3154
3155 /* Copy the value into the register, thus bridging between
3156 assign_parm_find_data_types and expand_expr_real_1. */
3157
3158 equiv_stack_parm = data->stack_parm;
3159 validated_mem = validize_mem (copy_rtx (data->entry_parm));
3160
3161 need_conversion = (data->nominal_mode != data->passed_mode
3162 || promoted_nominal_mode != data->promoted_mode);
3163 moved = false;
3164
3165 if (need_conversion
3166 && GET_MODE_CLASS (data->nominal_mode) == MODE_INT
3167 && data->nominal_mode == data->passed_mode
3168 && data->nominal_mode == GET_MODE (data->entry_parm))
3169 {
3170 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
3171 mode, by the caller. We now have to convert it to
3172 NOMINAL_MODE, if different. However, PARMREG may be in
3173 a different mode than NOMINAL_MODE if it is being stored
3174 promoted.
3175
3176 If ENTRY_PARM is a hard register, it might be in a register
3177 not valid for operating in its mode (e.g., an odd-numbered
3178 register for a DFmode). In that case, moves are the only
3179 thing valid, so we can't do a convert from there. This
3180 occurs when the calling sequence allow such misaligned
3181 usages.
3182
3183 In addition, the conversion may involve a call, which could
3184 clobber parameters which haven't been copied to pseudo
3185 registers yet.
3186
3187 First, we try to emit an insn which performs the necessary
3188 conversion. We verify that this insn does not clobber any
3189 hard registers. */
3190
3191 enum insn_code icode;
3192 rtx op0, op1;
3193
3194 icode = can_extend_p (promoted_nominal_mode, data->passed_mode,
3195 unsignedp);
3196
3197 op0 = parmreg;
3198 op1 = validated_mem;
3199 if (icode != CODE_FOR_nothing
3200 && insn_operand_matches (icode, 0, op0)
3201 && insn_operand_matches (icode, 1, op1))
3202 {
3203 enum rtx_code code = unsignedp ? ZERO_EXTEND : SIGN_EXTEND;
3204 rtx_insn *insn, *insns;
3205 rtx t = op1;
3206 HARD_REG_SET hardregs;
3207
3208 start_sequence ();
3209 /* If op1 is a hard register that is likely spilled, first
3210 force it into a pseudo, otherwise combiner might extend
3211 its lifetime too much. */
3212 if (GET_CODE (t) == SUBREG)
3213 t = SUBREG_REG (t);
3214 if (REG_P (t)
3215 && HARD_REGISTER_P (t)
3216 && ! TEST_HARD_REG_BIT (fixed_reg_set, REGNO (t))
3217 && targetm.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (t))))
3218 {
3219 t = gen_reg_rtx (GET_MODE (op1));
3220 emit_move_insn (t, op1);
3221 }
3222 else
3223 t = op1;
3224 rtx_insn *pat = gen_extend_insn (op0, t, promoted_nominal_mode,
3225 data->passed_mode, unsignedp);
3226 emit_insn (pat);
3227 insns = get_insns ();
3228
3229 moved = true;
3230 CLEAR_HARD_REG_SET (hardregs);
3231 for (insn = insns; insn && moved; insn = NEXT_INSN (insn))
3232 {
3233 if (INSN_P (insn))
3234 note_stores (PATTERN (insn), record_hard_reg_sets,
3235 &hardregs);
3236 if (!hard_reg_set_empty_p (hardregs))
3237 moved = false;
3238 }
3239
3240 end_sequence ();
3241
3242 if (moved)
3243 {
3244 emit_insn (insns);
3245 if (equiv_stack_parm != NULL_RTX)
3246 equiv_stack_parm = gen_rtx_fmt_e (code, GET_MODE (parmreg),
3247 equiv_stack_parm);
3248 }
3249 }
3250 }
3251
3252 if (moved)
3253 /* Nothing to do. */
3254 ;
3255 else if (need_conversion)
3256 {
3257 /* We did not have an insn to convert directly, or the sequence
3258 generated appeared unsafe. We must first copy the parm to a
3259 pseudo reg, and save the conversion until after all
3260 parameters have been moved. */
3261
3262 int save_tree_used;
3263 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
3264
3265 emit_move_insn (tempreg, validated_mem);
3266
3267 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3268 tempreg = convert_to_mode (data->nominal_mode, tempreg, unsignedp);
3269
3270 if (partial_subreg_p (tempreg)
3271 && GET_MODE (tempreg) == data->nominal_mode
3272 && REG_P (SUBREG_REG (tempreg))
3273 && data->nominal_mode == data->passed_mode
3274 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (data->entry_parm))
3275 {
3276 /* The argument is already sign/zero extended, so note it
3277 into the subreg. */
3278 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
3279 SUBREG_PROMOTED_SET (tempreg, unsignedp);
3280 }
3281
3282 /* TREE_USED gets set erroneously during expand_assignment. */
3283 save_tree_used = TREE_USED (parm);
3284 SET_DECL_RTL (parm, rtl);
3285 expand_assignment (parm, make_tree (data->nominal_type, tempreg), false);
3286 SET_DECL_RTL (parm, NULL_RTX);
3287 TREE_USED (parm) = save_tree_used;
3288 all->first_conversion_insn = get_insns ();
3289 all->last_conversion_insn = get_last_insn ();
3290 end_sequence ();
3291
3292 did_conversion = true;
3293 }
3294 else
3295 emit_move_insn (parmreg, validated_mem);
3296
3297 /* If we were passed a pointer but the actual value can safely live
3298 in a register, retrieve it and use it directly. */
3299 if (data->passed_pointer && TYPE_MODE (TREE_TYPE (parm)) != BLKmode)
3300 {
3301 /* We can't use nominal_mode, because it will have been set to
3302 Pmode above. We must use the actual mode of the parm. */
3303 if (use_register_for_decl (parm))
3304 {
3305 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
3306 mark_user_reg (parmreg);
3307 }
3308 else
3309 {
3310 int align = STACK_SLOT_ALIGNMENT (TREE_TYPE (parm),
3311 TYPE_MODE (TREE_TYPE (parm)),
3312 TYPE_ALIGN (TREE_TYPE (parm)));
3313 parmreg
3314 = assign_stack_local (TYPE_MODE (TREE_TYPE (parm)),
3315 GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (parm))),
3316 align);
3317 set_mem_attributes (parmreg, parm, 1);
3318 }
3319
3320 /* We need to preserve an address based on VIRTUAL_STACK_VARS_REGNUM for
3321 the debug info in case it is not legitimate. */
3322 if (GET_MODE (parmreg) != GET_MODE (rtl))
3323 {
3324 rtx tempreg = gen_reg_rtx (GET_MODE (rtl));
3325 int unsigned_p = TYPE_UNSIGNED (TREE_TYPE (parm));
3326
3327 push_to_sequence2 (all->first_conversion_insn,
3328 all->last_conversion_insn);
3329 emit_move_insn (tempreg, rtl);
3330 tempreg = convert_to_mode (GET_MODE (parmreg), tempreg, unsigned_p);
3331 emit_move_insn (MEM_P (parmreg) ? copy_rtx (parmreg) : parmreg,
3332 tempreg);
3333 all->first_conversion_insn = get_insns ();
3334 all->last_conversion_insn = get_last_insn ();
3335 end_sequence ();
3336
3337 did_conversion = true;
3338 }
3339 else
3340 emit_move_insn (MEM_P (parmreg) ? copy_rtx (parmreg) : parmreg, rtl);
3341
3342 rtl = parmreg;
3343
3344 /* STACK_PARM is the pointer, not the parm, and PARMREG is
3345 now the parm. */
3346 data->stack_parm = NULL;
3347 }
3348
3349 set_parm_rtl (parm, rtl);
3350
3351 /* Mark the register as eliminable if we did no conversion and it was
3352 copied from memory at a fixed offset, and the arg pointer was not
3353 copied to a pseudo-reg. If the arg pointer is a pseudo reg or the
3354 offset formed an invalid address, such memory-equivalences as we
3355 make here would screw up life analysis for it. */
3356 if (data->nominal_mode == data->passed_mode
3357 && !did_conversion
3358 && data->stack_parm != 0
3359 && MEM_P (data->stack_parm)
3360 && data->locate.offset.var == 0
3361 && reg_mentioned_p (virtual_incoming_args_rtx,
3362 XEXP (data->stack_parm, 0)))
3363 {
3364 rtx_insn *linsn = get_last_insn ();
3365 rtx_insn *sinsn;
3366 rtx set;
3367
3368 /* Mark complex types separately. */
3369 if (GET_CODE (parmreg) == CONCAT)
3370 {
3371 scalar_mode submode = GET_MODE_INNER (GET_MODE (parmreg));
3372 int regnor = REGNO (XEXP (parmreg, 0));
3373 int regnoi = REGNO (XEXP (parmreg, 1));
3374 rtx stackr = adjust_address_nv (data->stack_parm, submode, 0);
3375 rtx stacki = adjust_address_nv (data->stack_parm, submode,
3376 GET_MODE_SIZE (submode));
3377
3378 /* Scan backwards for the set of the real and
3379 imaginary parts. */
3380 for (sinsn = linsn; sinsn != 0;
3381 sinsn = prev_nonnote_insn (sinsn))
3382 {
3383 set = single_set (sinsn);
3384 if (set == 0)
3385 continue;
3386
3387 if (SET_DEST (set) == regno_reg_rtx [regnoi])
3388 set_unique_reg_note (sinsn, REG_EQUIV, stacki);
3389 else if (SET_DEST (set) == regno_reg_rtx [regnor])
3390 set_unique_reg_note (sinsn, REG_EQUIV, stackr);
3391 }
3392 }
3393 else
3394 set_dst_reg_note (linsn, REG_EQUIV, equiv_stack_parm, parmreg);
3395 }
3396
3397 /* For pointer data type, suggest pointer register. */
3398 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3399 mark_reg_pointer (parmreg,
3400 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
3401 }
3402
3403 /* A subroutine of assign_parms. Allocate stack space to hold the current
3404 parameter. Get it there. Perform all ABI specified conversions. */
3405
3406 static void
3407 assign_parm_setup_stack (struct assign_parm_data_all *all, tree parm,
3408 struct assign_parm_data_one *data)
3409 {
3410 /* Value must be stored in the stack slot STACK_PARM during function
3411 execution. */
3412 bool to_conversion = false;
3413
3414 assign_parm_remove_parallels (data);
3415
3416 if (data->promoted_mode != data->nominal_mode)
3417 {
3418 /* Conversion is required. */
3419 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
3420
3421 emit_move_insn (tempreg, validize_mem (copy_rtx (data->entry_parm)));
3422
3423 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3424 to_conversion = true;
3425
3426 data->entry_parm = convert_to_mode (data->nominal_mode, tempreg,
3427 TYPE_UNSIGNED (TREE_TYPE (parm)));
3428
3429 if (data->stack_parm)
3430 {
3431 poly_int64 offset
3432 = subreg_lowpart_offset (data->nominal_mode,
3433 GET_MODE (data->stack_parm));
3434 /* ??? This may need a big-endian conversion on sparc64. */
3435 data->stack_parm
3436 = adjust_address (data->stack_parm, data->nominal_mode, 0);
3437 if (maybe_ne (offset, 0) && MEM_OFFSET_KNOWN_P (data->stack_parm))
3438 set_mem_offset (data->stack_parm,
3439 MEM_OFFSET (data->stack_parm) + offset);
3440 }
3441 }
3442
3443 if (data->entry_parm != data->stack_parm)
3444 {
3445 rtx src, dest;
3446
3447 if (data->stack_parm == 0)
3448 {
3449 int align = STACK_SLOT_ALIGNMENT (data->passed_type,
3450 GET_MODE (data->entry_parm),
3451 TYPE_ALIGN (data->passed_type));
3452 data->stack_parm
3453 = assign_stack_local (GET_MODE (data->entry_parm),
3454 GET_MODE_SIZE (GET_MODE (data->entry_parm)),
3455 align);
3456 set_mem_attributes (data->stack_parm, parm, 1);
3457 }
3458
3459 dest = validize_mem (copy_rtx (data->stack_parm));
3460 src = validize_mem (copy_rtx (data->entry_parm));
3461
3462 if (MEM_P (src))
3463 {
3464 /* Use a block move to handle potentially misaligned entry_parm. */
3465 if (!to_conversion)
3466 push_to_sequence2 (all->first_conversion_insn,
3467 all->last_conversion_insn);
3468 to_conversion = true;
3469
3470 emit_block_move (dest, src,
3471 GEN_INT (int_size_in_bytes (data->passed_type)),
3472 BLOCK_OP_NORMAL);
3473 }
3474 else
3475 {
3476 if (!REG_P (src))
3477 src = force_reg (GET_MODE (src), src);
3478 emit_move_insn (dest, src);
3479 }
3480 }
3481
3482 if (to_conversion)
3483 {
3484 all->first_conversion_insn = get_insns ();
3485 all->last_conversion_insn = get_last_insn ();
3486 end_sequence ();
3487 }
3488
3489 set_parm_rtl (parm, data->stack_parm);
3490 }
3491
3492 /* A subroutine of assign_parms. If the ABI splits complex arguments, then
3493 undo the frobbing that we did in assign_parms_augmented_arg_list. */
3494
3495 static void
3496 assign_parms_unsplit_complex (struct assign_parm_data_all *all,
3497 vec<tree> fnargs)
3498 {
3499 tree parm;
3500 tree orig_fnargs = all->orig_fnargs;
3501 unsigned i = 0;
3502
3503 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm), ++i)
3504 {
3505 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
3506 && targetm.calls.split_complex_arg (TREE_TYPE (parm)))
3507 {
3508 rtx tmp, real, imag;
3509 scalar_mode inner = GET_MODE_INNER (DECL_MODE (parm));
3510
3511 real = DECL_RTL (fnargs[i]);
3512 imag = DECL_RTL (fnargs[i + 1]);
3513 if (inner != GET_MODE (real))
3514 {
3515 real = gen_lowpart_SUBREG (inner, real);
3516 imag = gen_lowpart_SUBREG (inner, imag);
3517 }
3518
3519 if (TREE_ADDRESSABLE (parm))
3520 {
3521 rtx rmem, imem;
3522 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (parm));
3523 int align = STACK_SLOT_ALIGNMENT (TREE_TYPE (parm),
3524 DECL_MODE (parm),
3525 TYPE_ALIGN (TREE_TYPE (parm)));
3526
3527 /* split_complex_arg put the real and imag parts in
3528 pseudos. Move them to memory. */
3529 tmp = assign_stack_local (DECL_MODE (parm), size, align);
3530 set_mem_attributes (tmp, parm, 1);
3531 rmem = adjust_address_nv (tmp, inner, 0);
3532 imem = adjust_address_nv (tmp, inner, GET_MODE_SIZE (inner));
3533 push_to_sequence2 (all->first_conversion_insn,
3534 all->last_conversion_insn);
3535 emit_move_insn (rmem, real);
3536 emit_move_insn (imem, imag);
3537 all->first_conversion_insn = get_insns ();
3538 all->last_conversion_insn = get_last_insn ();
3539 end_sequence ();
3540 }
3541 else
3542 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
3543 set_parm_rtl (parm, tmp);
3544
3545 real = DECL_INCOMING_RTL (fnargs[i]);
3546 imag = DECL_INCOMING_RTL (fnargs[i + 1]);
3547 if (inner != GET_MODE (real))
3548 {
3549 real = gen_lowpart_SUBREG (inner, real);
3550 imag = gen_lowpart_SUBREG (inner, imag);
3551 }
3552 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
3553 set_decl_incoming_rtl (parm, tmp, false);
3554 i++;
3555 }
3556 }
3557 }
3558
3559 /* Assign RTL expressions to the function's parameters. This may involve
3560 copying them into registers and using those registers as the DECL_RTL. */
3561
3562 static void
3563 assign_parms (tree fndecl)
3564 {
3565 struct assign_parm_data_all all;
3566 tree parm;
3567 vec<tree> fnargs;
3568 unsigned i;
3569
3570 crtl->args.internal_arg_pointer
3571 = targetm.calls.internal_arg_pointer ();
3572
3573 assign_parms_initialize_all (&all);
3574 fnargs = assign_parms_augmented_arg_list (&all);
3575
3576 FOR_EACH_VEC_ELT (fnargs, i, parm)
3577 {
3578 struct assign_parm_data_one data;
3579
3580 /* Extract the type of PARM; adjust it according to ABI. */
3581 assign_parm_find_data_types (&all, parm, &data);
3582
3583 /* Early out for errors and void parameters. */
3584 if (data.passed_mode == VOIDmode)
3585 {
3586 SET_DECL_RTL (parm, const0_rtx);
3587 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
3588 continue;
3589 }
3590
3591 /* Estimate stack alignment from parameter alignment. */
3592 if (SUPPORTS_STACK_ALIGNMENT)
3593 {
3594 unsigned int align
3595 = targetm.calls.function_arg_boundary (data.promoted_mode,
3596 data.passed_type);
3597 align = MINIMUM_ALIGNMENT (data.passed_type, data.promoted_mode,
3598 align);
3599 if (TYPE_ALIGN (data.nominal_type) > align)
3600 align = MINIMUM_ALIGNMENT (data.nominal_type,
3601 TYPE_MODE (data.nominal_type),
3602 TYPE_ALIGN (data.nominal_type));
3603 if (crtl->stack_alignment_estimated < align)
3604 {
3605 gcc_assert (!crtl->stack_realign_processed);
3606 crtl->stack_alignment_estimated = align;
3607 }
3608 }
3609
3610 /* Find out where the parameter arrives in this function. */
3611 assign_parm_find_entry_rtl (&all, &data);
3612
3613 /* Find out where stack space for this parameter might be. */
3614 if (assign_parm_is_stack_parm (&all, &data))
3615 {
3616 assign_parm_find_stack_rtl (parm, &data);
3617 assign_parm_adjust_entry_rtl (&data);
3618 }
3619 /* Record permanently how this parm was passed. */
3620 if (data.passed_pointer)
3621 {
3622 rtx incoming_rtl
3623 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data.passed_type)),
3624 data.entry_parm);
3625 set_decl_incoming_rtl (parm, incoming_rtl, true);
3626 }
3627 else
3628 set_decl_incoming_rtl (parm, data.entry_parm, false);
3629
3630 assign_parm_adjust_stack_rtl (&data);
3631
3632 if (assign_parm_setup_block_p (&data))
3633 assign_parm_setup_block (&all, parm, &data);
3634 else if (data.passed_pointer || use_register_for_decl (parm))
3635 assign_parm_setup_reg (&all, parm, &data);
3636 else
3637 assign_parm_setup_stack (&all, parm, &data);
3638
3639 if (cfun->stdarg && !DECL_CHAIN (parm))
3640 assign_parms_setup_varargs (&all, &data, false);
3641
3642 /* Update info on where next arg arrives in registers. */
3643 targetm.calls.function_arg_advance (all.args_so_far, data.promoted_mode,
3644 data.passed_type, data.named_arg);
3645 }
3646
3647 if (targetm.calls.split_complex_arg)
3648 assign_parms_unsplit_complex (&all, fnargs);
3649
3650 fnargs.release ();
3651
3652 /* Output all parameter conversion instructions (possibly including calls)
3653 now that all parameters have been copied out of hard registers. */
3654 emit_insn (all.first_conversion_insn);
3655
3656 /* Estimate reload stack alignment from scalar return mode. */
3657 if (SUPPORTS_STACK_ALIGNMENT)
3658 {
3659 if (DECL_RESULT (fndecl))
3660 {
3661 tree type = TREE_TYPE (DECL_RESULT (fndecl));
3662 machine_mode mode = TYPE_MODE (type);
3663
3664 if (mode != BLKmode
3665 && mode != VOIDmode
3666 && !AGGREGATE_TYPE_P (type))
3667 {
3668 unsigned int align = GET_MODE_ALIGNMENT (mode);
3669 if (crtl->stack_alignment_estimated < align)
3670 {
3671 gcc_assert (!crtl->stack_realign_processed);
3672 crtl->stack_alignment_estimated = align;
3673 }
3674 }
3675 }
3676 }
3677
3678 /* If we are receiving a struct value address as the first argument, set up
3679 the RTL for the function result. As this might require code to convert
3680 the transmitted address to Pmode, we do this here to ensure that possible
3681 preliminary conversions of the address have been emitted already. */
3682 if (all.function_result_decl)
3683 {
3684 tree result = DECL_RESULT (current_function_decl);
3685 rtx addr = DECL_RTL (all.function_result_decl);
3686 rtx x;
3687
3688 if (DECL_BY_REFERENCE (result))
3689 {
3690 SET_DECL_VALUE_EXPR (result, all.function_result_decl);
3691 x = addr;
3692 }
3693 else
3694 {
3695 SET_DECL_VALUE_EXPR (result,
3696 build1 (INDIRECT_REF, TREE_TYPE (result),
3697 all.function_result_decl));
3698 addr = convert_memory_address (Pmode, addr);
3699 x = gen_rtx_MEM (DECL_MODE (result), addr);
3700 set_mem_attributes (x, result, 1);
3701 }
3702
3703 DECL_HAS_VALUE_EXPR_P (result) = 1;
3704
3705 set_parm_rtl (result, x);
3706 }
3707
3708 /* We have aligned all the args, so add space for the pretend args. */
3709 crtl->args.pretend_args_size = all.pretend_args_size;
3710 all.stack_args_size.constant += all.extra_pretend_bytes;
3711 crtl->args.size = all.stack_args_size.constant;
3712
3713 /* Adjust function incoming argument size for alignment and
3714 minimum length. */
3715
3716 crtl->args.size = upper_bound (crtl->args.size, all.reg_parm_stack_space);
3717 crtl->args.size = aligned_upper_bound (crtl->args.size,
3718 PARM_BOUNDARY / BITS_PER_UNIT);
3719
3720 if (ARGS_GROW_DOWNWARD)
3721 {
3722 crtl->args.arg_offset_rtx
3723 = (all.stack_args_size.var == 0
3724 ? gen_int_mode (-all.stack_args_size.constant, Pmode)
3725 : expand_expr (size_diffop (all.stack_args_size.var,
3726 size_int (-all.stack_args_size.constant)),
3727 NULL_RTX, VOIDmode, EXPAND_NORMAL));
3728 }
3729 else
3730 crtl->args.arg_offset_rtx = ARGS_SIZE_RTX (all.stack_args_size);
3731
3732 /* See how many bytes, if any, of its args a function should try to pop
3733 on return. */
3734
3735 crtl->args.pops_args = targetm.calls.return_pops_args (fndecl,
3736 TREE_TYPE (fndecl),
3737 crtl->args.size);
3738
3739 /* For stdarg.h function, save info about
3740 regs and stack space used by the named args. */
3741
3742 crtl->args.info = all.args_so_far_v;
3743
3744 /* Set the rtx used for the function return value. Put this in its
3745 own variable so any optimizers that need this information don't have
3746 to include tree.h. Do this here so it gets done when an inlined
3747 function gets output. */
3748
3749 crtl->return_rtx
3750 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
3751 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
3752
3753 /* If scalar return value was computed in a pseudo-reg, or was a named
3754 return value that got dumped to the stack, copy that to the hard
3755 return register. */
3756 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
3757 {
3758 tree decl_result = DECL_RESULT (fndecl);
3759 rtx decl_rtl = DECL_RTL (decl_result);
3760
3761 if (REG_P (decl_rtl)
3762 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
3763 : DECL_REGISTER (decl_result))
3764 {
3765 rtx real_decl_rtl;
3766
3767 real_decl_rtl = targetm.calls.function_value (TREE_TYPE (decl_result),
3768 fndecl, true);
3769 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
3770 /* The delay slot scheduler assumes that crtl->return_rtx
3771 holds the hard register containing the return value, not a
3772 temporary pseudo. */
3773 crtl->return_rtx = real_decl_rtl;
3774 }
3775 }
3776 }
3777
3778 /* A subroutine of gimplify_parameters, invoked via walk_tree.
3779 For all seen types, gimplify their sizes. */
3780
3781 static tree
3782 gimplify_parm_type (tree *tp, int *walk_subtrees, void *data)
3783 {
3784 tree t = *tp;
3785
3786 *walk_subtrees = 0;
3787 if (TYPE_P (t))
3788 {
3789 if (POINTER_TYPE_P (t))
3790 *walk_subtrees = 1;
3791 else if (TYPE_SIZE (t) && !TREE_CONSTANT (TYPE_SIZE (t))
3792 && !TYPE_SIZES_GIMPLIFIED (t))
3793 {
3794 gimplify_type_sizes (t, (gimple_seq *) data);
3795 *walk_subtrees = 1;
3796 }
3797 }
3798
3799 return NULL;
3800 }
3801
3802 /* Gimplify the parameter list for current_function_decl. This involves
3803 evaluating SAVE_EXPRs of variable sized parameters and generating code
3804 to implement callee-copies reference parameters. Returns a sequence of
3805 statements to add to the beginning of the function. */
3806
3807 gimple_seq
3808 gimplify_parameters (gimple_seq *cleanup)
3809 {
3810 struct assign_parm_data_all all;
3811 tree parm;
3812 gimple_seq stmts = NULL;
3813 vec<tree> fnargs;
3814 unsigned i;
3815
3816 assign_parms_initialize_all (&all);
3817 fnargs = assign_parms_augmented_arg_list (&all);
3818
3819 FOR_EACH_VEC_ELT (fnargs, i, parm)
3820 {
3821 struct assign_parm_data_one data;
3822
3823 /* Extract the type of PARM; adjust it according to ABI. */
3824 assign_parm_find_data_types (&all, parm, &data);
3825
3826 /* Early out for errors and void parameters. */
3827 if (data.passed_mode == VOIDmode || DECL_SIZE (parm) == NULL)
3828 continue;
3829
3830 /* Update info on where next arg arrives in registers. */
3831 targetm.calls.function_arg_advance (all.args_so_far, data.promoted_mode,
3832 data.passed_type, data.named_arg);
3833
3834 /* ??? Once upon a time variable_size stuffed parameter list
3835 SAVE_EXPRs (amongst others) onto a pending sizes list. This
3836 turned out to be less than manageable in the gimple world.
3837 Now we have to hunt them down ourselves. */
3838 walk_tree_without_duplicates (&data.passed_type,
3839 gimplify_parm_type, &stmts);
3840
3841 if (TREE_CODE (DECL_SIZE_UNIT (parm)) != INTEGER_CST)
3842 {
3843 gimplify_one_sizepos (&DECL_SIZE (parm), &stmts);
3844 gimplify_one_sizepos (&DECL_SIZE_UNIT (parm), &stmts);
3845 }
3846
3847 if (data.passed_pointer)
3848 {
3849 tree type = TREE_TYPE (data.passed_type);
3850 if (reference_callee_copied (&all.args_so_far_v, TYPE_MODE (type),
3851 type, data.named_arg))
3852 {
3853 tree local, t;
3854
3855 /* For constant-sized objects, this is trivial; for
3856 variable-sized objects, we have to play games. */
3857 if (TREE_CODE (DECL_SIZE_UNIT (parm)) == INTEGER_CST
3858 && !(flag_stack_check == GENERIC_STACK_CHECK
3859 && compare_tree_int (DECL_SIZE_UNIT (parm),
3860 STACK_CHECK_MAX_VAR_SIZE) > 0))
3861 {
3862 local = create_tmp_var (type, get_name (parm));
3863 DECL_IGNORED_P (local) = 0;
3864 /* If PARM was addressable, move that flag over
3865 to the local copy, as its address will be taken,
3866 not the PARMs. Keep the parms address taken
3867 as we'll query that flag during gimplification. */
3868 if (TREE_ADDRESSABLE (parm))
3869 TREE_ADDRESSABLE (local) = 1;
3870 else if (TREE_CODE (type) == COMPLEX_TYPE
3871 || TREE_CODE (type) == VECTOR_TYPE)
3872 DECL_GIMPLE_REG_P (local) = 1;
3873
3874 if (!is_gimple_reg (local)
3875 && flag_stack_reuse != SR_NONE)
3876 {
3877 tree clobber = build_constructor (type, NULL);
3878 gimple *clobber_stmt;
3879 TREE_THIS_VOLATILE (clobber) = 1;
3880 clobber_stmt = gimple_build_assign (local, clobber);
3881 gimple_seq_add_stmt (cleanup, clobber_stmt);
3882 }
3883 }
3884 else
3885 {
3886 tree ptr_type, addr;
3887
3888 ptr_type = build_pointer_type (type);
3889 addr = create_tmp_reg (ptr_type, get_name (parm));
3890 DECL_IGNORED_P (addr) = 0;
3891 local = build_fold_indirect_ref (addr);
3892
3893 t = build_alloca_call_expr (DECL_SIZE_UNIT (parm),
3894 DECL_ALIGN (parm),
3895 max_int_size_in_bytes (type));
3896 /* The call has been built for a variable-sized object. */
3897 CALL_ALLOCA_FOR_VAR_P (t) = 1;
3898 t = fold_convert (ptr_type, t);
3899 t = build2 (MODIFY_EXPR, TREE_TYPE (addr), addr, t);
3900 gimplify_and_add (t, &stmts);
3901 }
3902
3903 gimplify_assign (local, parm, &stmts);
3904
3905 SET_DECL_VALUE_EXPR (parm, local);
3906 DECL_HAS_VALUE_EXPR_P (parm) = 1;
3907 }
3908 }
3909 }
3910
3911 fnargs.release ();
3912
3913 return stmts;
3914 }
3915 \f
3916 /* Compute the size and offset from the start of the stacked arguments for a
3917 parm passed in mode PASSED_MODE and with type TYPE.
3918
3919 INITIAL_OFFSET_PTR points to the current offset into the stacked
3920 arguments.
3921
3922 The starting offset and size for this parm are returned in
3923 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
3924 nonzero, the offset is that of stack slot, which is returned in
3925 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
3926 padding required from the initial offset ptr to the stack slot.
3927
3928 IN_REGS is nonzero if the argument will be passed in registers. It will
3929 never be set if REG_PARM_STACK_SPACE is not defined.
3930
3931 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
3932 for arguments which are passed in registers.
3933
3934 FNDECL is the function in which the argument was defined.
3935
3936 There are two types of rounding that are done. The first, controlled by
3937 TARGET_FUNCTION_ARG_BOUNDARY, forces the offset from the start of the
3938 argument list to be aligned to the specific boundary (in bits). This
3939 rounding affects the initial and starting offsets, but not the argument
3940 size.
3941
3942 The second, controlled by TARGET_FUNCTION_ARG_PADDING and PARM_BOUNDARY,
3943 optionally rounds the size of the parm to PARM_BOUNDARY. The
3944 initial offset is not affected by this rounding, while the size always
3945 is and the starting offset may be. */
3946
3947 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
3948 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
3949 callers pass in the total size of args so far as
3950 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
3951
3952 void
3953 locate_and_pad_parm (machine_mode passed_mode, tree type, int in_regs,
3954 int reg_parm_stack_space, int partial,
3955 tree fndecl ATTRIBUTE_UNUSED,
3956 struct args_size *initial_offset_ptr,
3957 struct locate_and_pad_arg_data *locate)
3958 {
3959 tree sizetree;
3960 pad_direction where_pad;
3961 unsigned int boundary, round_boundary;
3962 int part_size_in_regs;
3963
3964 /* If we have found a stack parm before we reach the end of the
3965 area reserved for registers, skip that area. */
3966 if (! in_regs)
3967 {
3968 if (reg_parm_stack_space > 0)
3969 {
3970 if (initial_offset_ptr->var
3971 || !ordered_p (initial_offset_ptr->constant,
3972 reg_parm_stack_space))
3973 {
3974 initial_offset_ptr->var
3975 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
3976 ssize_int (reg_parm_stack_space));
3977 initial_offset_ptr->constant = 0;
3978 }
3979 else
3980 initial_offset_ptr->constant
3981 = ordered_max (initial_offset_ptr->constant,
3982 reg_parm_stack_space);
3983 }
3984 }
3985
3986 part_size_in_regs = (reg_parm_stack_space == 0 ? partial : 0);
3987
3988 sizetree = (type
3989 ? arg_size_in_bytes (type)
3990 : size_int (GET_MODE_SIZE (passed_mode)));
3991 where_pad = targetm.calls.function_arg_padding (passed_mode, type);
3992 boundary = targetm.calls.function_arg_boundary (passed_mode, type);
3993 round_boundary = targetm.calls.function_arg_round_boundary (passed_mode,
3994 type);
3995 locate->where_pad = where_pad;
3996
3997 /* Alignment can't exceed MAX_SUPPORTED_STACK_ALIGNMENT. */
3998 if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
3999 boundary = MAX_SUPPORTED_STACK_ALIGNMENT;
4000
4001 locate->boundary = boundary;
4002
4003 if (SUPPORTS_STACK_ALIGNMENT)
4004 {
4005 /* stack_alignment_estimated can't change after stack has been
4006 realigned. */
4007 if (crtl->stack_alignment_estimated < boundary)
4008 {
4009 if (!crtl->stack_realign_processed)
4010 crtl->stack_alignment_estimated = boundary;
4011 else
4012 {
4013 /* If stack is realigned and stack alignment value
4014 hasn't been finalized, it is OK not to increase
4015 stack_alignment_estimated. The bigger alignment
4016 requirement is recorded in stack_alignment_needed
4017 below. */
4018 gcc_assert (!crtl->stack_realign_finalized
4019 && crtl->stack_realign_needed);
4020 }
4021 }
4022 }
4023
4024 /* Remember if the outgoing parameter requires extra alignment on the
4025 calling function side. */
4026 if (crtl->stack_alignment_needed < boundary)
4027 crtl->stack_alignment_needed = boundary;
4028 if (crtl->preferred_stack_boundary < boundary)
4029 crtl->preferred_stack_boundary = boundary;
4030
4031 if (ARGS_GROW_DOWNWARD)
4032 {
4033 locate->slot_offset.constant = -initial_offset_ptr->constant;
4034 if (initial_offset_ptr->var)
4035 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
4036 initial_offset_ptr->var);
4037
4038 {
4039 tree s2 = sizetree;
4040 if (where_pad != PAD_NONE
4041 && (!tree_fits_uhwi_p (sizetree)
4042 || (tree_to_uhwi (sizetree) * BITS_PER_UNIT) % round_boundary))
4043 s2 = round_up (s2, round_boundary / BITS_PER_UNIT);
4044 SUB_PARM_SIZE (locate->slot_offset, s2);
4045 }
4046
4047 locate->slot_offset.constant += part_size_in_regs;
4048
4049 if (!in_regs || reg_parm_stack_space > 0)
4050 pad_to_arg_alignment (&locate->slot_offset, boundary,
4051 &locate->alignment_pad);
4052
4053 locate->size.constant = (-initial_offset_ptr->constant
4054 - locate->slot_offset.constant);
4055 if (initial_offset_ptr->var)
4056 locate->size.var = size_binop (MINUS_EXPR,
4057 size_binop (MINUS_EXPR,
4058 ssize_int (0),
4059 initial_offset_ptr->var),
4060 locate->slot_offset.var);
4061
4062 /* Pad_below needs the pre-rounded size to know how much to pad
4063 below. */
4064 locate->offset = locate->slot_offset;
4065 if (where_pad == PAD_DOWNWARD)
4066 pad_below (&locate->offset, passed_mode, sizetree);
4067
4068 }
4069 else
4070 {
4071 if (!in_regs || reg_parm_stack_space > 0)
4072 pad_to_arg_alignment (initial_offset_ptr, boundary,
4073 &locate->alignment_pad);
4074 locate->slot_offset = *initial_offset_ptr;
4075
4076 #ifdef PUSH_ROUNDING
4077 if (passed_mode != BLKmode)
4078 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
4079 #endif
4080
4081 /* Pad_below needs the pre-rounded size to know how much to pad below
4082 so this must be done before rounding up. */
4083 locate->offset = locate->slot_offset;
4084 if (where_pad == PAD_DOWNWARD)
4085 pad_below (&locate->offset, passed_mode, sizetree);
4086
4087 if (where_pad != PAD_NONE
4088 && (!tree_fits_uhwi_p (sizetree)
4089 || (tree_to_uhwi (sizetree) * BITS_PER_UNIT) % round_boundary))
4090 sizetree = round_up (sizetree, round_boundary / BITS_PER_UNIT);
4091
4092 ADD_PARM_SIZE (locate->size, sizetree);
4093
4094 locate->size.constant -= part_size_in_regs;
4095 }
4096
4097 locate->offset.constant
4098 += targetm.calls.function_arg_offset (passed_mode, type);
4099 }
4100
4101 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
4102 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
4103
4104 static void
4105 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
4106 struct args_size *alignment_pad)
4107 {
4108 tree save_var = NULL_TREE;
4109 poly_int64 save_constant = 0;
4110 int boundary_in_bytes = boundary / BITS_PER_UNIT;
4111 poly_int64 sp_offset = STACK_POINTER_OFFSET;
4112
4113 #ifdef SPARC_STACK_BOUNDARY_HACK
4114 /* ??? The SPARC port may claim a STACK_BOUNDARY higher than
4115 the real alignment of %sp. However, when it does this, the
4116 alignment of %sp+STACK_POINTER_OFFSET is STACK_BOUNDARY. */
4117 if (SPARC_STACK_BOUNDARY_HACK)
4118 sp_offset = 0;
4119 #endif
4120
4121 if (boundary > PARM_BOUNDARY)
4122 {
4123 save_var = offset_ptr->var;
4124 save_constant = offset_ptr->constant;
4125 }
4126
4127 alignment_pad->var = NULL_TREE;
4128 alignment_pad->constant = 0;
4129
4130 if (boundary > BITS_PER_UNIT)
4131 {
4132 int misalign;
4133 if (offset_ptr->var
4134 || !known_misalignment (offset_ptr->constant + sp_offset,
4135 boundary_in_bytes, &misalign))
4136 {
4137 tree sp_offset_tree = ssize_int (sp_offset);
4138 tree offset = size_binop (PLUS_EXPR,
4139 ARGS_SIZE_TREE (*offset_ptr),
4140 sp_offset_tree);
4141 tree rounded;
4142 if (ARGS_GROW_DOWNWARD)
4143 rounded = round_down (offset, boundary / BITS_PER_UNIT);
4144 else
4145 rounded = round_up (offset, boundary / BITS_PER_UNIT);
4146
4147 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
4148 /* ARGS_SIZE_TREE includes constant term. */
4149 offset_ptr->constant = 0;
4150 if (boundary > PARM_BOUNDARY)
4151 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
4152 save_var);
4153 }
4154 else
4155 {
4156 if (ARGS_GROW_DOWNWARD)
4157 offset_ptr->constant -= misalign;
4158 else
4159 offset_ptr->constant += -misalign & (boundary_in_bytes - 1);
4160
4161 if (boundary > PARM_BOUNDARY)
4162 alignment_pad->constant = offset_ptr->constant - save_constant;
4163 }
4164 }
4165 }
4166
4167 static void
4168 pad_below (struct args_size *offset_ptr, machine_mode passed_mode, tree sizetree)
4169 {
4170 unsigned int align = PARM_BOUNDARY / BITS_PER_UNIT;
4171 int misalign;
4172 if (passed_mode != BLKmode
4173 && known_misalignment (GET_MODE_SIZE (passed_mode), align, &misalign))
4174 offset_ptr->constant += -misalign & (align - 1);
4175 else
4176 {
4177 if (TREE_CODE (sizetree) != INTEGER_CST
4178 || (TREE_INT_CST_LOW (sizetree) & (align - 1)) != 0)
4179 {
4180 /* Round the size up to multiple of PARM_BOUNDARY bits. */
4181 tree s2 = round_up (sizetree, align);
4182 /* Add it in. */
4183 ADD_PARM_SIZE (*offset_ptr, s2);
4184 SUB_PARM_SIZE (*offset_ptr, sizetree);
4185 }
4186 }
4187 }
4188 \f
4189
4190 /* True if register REGNO was alive at a place where `setjmp' was
4191 called and was set more than once or is an argument. Such regs may
4192 be clobbered by `longjmp'. */
4193
4194 static bool
4195 regno_clobbered_at_setjmp (bitmap setjmp_crosses, int regno)
4196 {
4197 /* There appear to be cases where some local vars never reach the
4198 backend but have bogus regnos. */
4199 if (regno >= max_reg_num ())
4200 return false;
4201
4202 return ((REG_N_SETS (regno) > 1
4203 || REGNO_REG_SET_P (df_get_live_out (ENTRY_BLOCK_PTR_FOR_FN (cfun)),
4204 regno))
4205 && REGNO_REG_SET_P (setjmp_crosses, regno));
4206 }
4207
4208 /* Walk the tree of blocks describing the binding levels within a
4209 function and warn about variables the might be killed by setjmp or
4210 vfork. This is done after calling flow_analysis before register
4211 allocation since that will clobber the pseudo-regs to hard
4212 regs. */
4213
4214 static void
4215 setjmp_vars_warning (bitmap setjmp_crosses, tree block)
4216 {
4217 tree decl, sub;
4218
4219 for (decl = BLOCK_VARS (block); decl; decl = DECL_CHAIN (decl))
4220 {
4221 if (VAR_P (decl)
4222 && DECL_RTL_SET_P (decl)
4223 && REG_P (DECL_RTL (decl))
4224 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
4225 warning (OPT_Wclobbered, "variable %q+D might be clobbered by"
4226 " %<longjmp%> or %<vfork%>", decl);
4227 }
4228
4229 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = BLOCK_CHAIN (sub))
4230 setjmp_vars_warning (setjmp_crosses, sub);
4231 }
4232
4233 /* Do the appropriate part of setjmp_vars_warning
4234 but for arguments instead of local variables. */
4235
4236 static void
4237 setjmp_args_warning (bitmap setjmp_crosses)
4238 {
4239 tree decl;
4240 for (decl = DECL_ARGUMENTS (current_function_decl);
4241 decl; decl = DECL_CHAIN (decl))
4242 if (DECL_RTL (decl) != 0
4243 && REG_P (DECL_RTL (decl))
4244 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
4245 warning (OPT_Wclobbered,
4246 "argument %q+D might be clobbered by %<longjmp%> or %<vfork%>",
4247 decl);
4248 }
4249
4250 /* Generate warning messages for variables live across setjmp. */
4251
4252 void
4253 generate_setjmp_warnings (void)
4254 {
4255 bitmap setjmp_crosses = regstat_get_setjmp_crosses ();
4256
4257 if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS
4258 || bitmap_empty_p (setjmp_crosses))
4259 return;
4260
4261 setjmp_vars_warning (setjmp_crosses, DECL_INITIAL (current_function_decl));
4262 setjmp_args_warning (setjmp_crosses);
4263 }
4264
4265 \f
4266 /* Reverse the order of elements in the fragment chain T of blocks,
4267 and return the new head of the chain (old last element).
4268 In addition to that clear BLOCK_SAME_RANGE flags when needed
4269 and adjust BLOCK_SUPERCONTEXT from the super fragment to
4270 its super fragment origin. */
4271
4272 static tree
4273 block_fragments_nreverse (tree t)
4274 {
4275 tree prev = 0, block, next, prev_super = 0;
4276 tree super = BLOCK_SUPERCONTEXT (t);
4277 if (BLOCK_FRAGMENT_ORIGIN (super))
4278 super = BLOCK_FRAGMENT_ORIGIN (super);
4279 for (block = t; block; block = next)
4280 {
4281 next = BLOCK_FRAGMENT_CHAIN (block);
4282 BLOCK_FRAGMENT_CHAIN (block) = prev;
4283 if ((prev && !BLOCK_SAME_RANGE (prev))
4284 || (BLOCK_FRAGMENT_CHAIN (BLOCK_SUPERCONTEXT (block))
4285 != prev_super))
4286 BLOCK_SAME_RANGE (block) = 0;
4287 prev_super = BLOCK_SUPERCONTEXT (block);
4288 BLOCK_SUPERCONTEXT (block) = super;
4289 prev = block;
4290 }
4291 t = BLOCK_FRAGMENT_ORIGIN (t);
4292 if (BLOCK_FRAGMENT_CHAIN (BLOCK_SUPERCONTEXT (t))
4293 != prev_super)
4294 BLOCK_SAME_RANGE (t) = 0;
4295 BLOCK_SUPERCONTEXT (t) = super;
4296 return prev;
4297 }
4298
4299 /* Reverse the order of elements in the chain T of blocks,
4300 and return the new head of the chain (old last element).
4301 Also do the same on subblocks and reverse the order of elements
4302 in BLOCK_FRAGMENT_CHAIN as well. */
4303
4304 static tree
4305 blocks_nreverse_all (tree t)
4306 {
4307 tree prev = 0, block, next;
4308 for (block = t; block; block = next)
4309 {
4310 next = BLOCK_CHAIN (block);
4311 BLOCK_CHAIN (block) = prev;
4312 if (BLOCK_FRAGMENT_CHAIN (block)
4313 && BLOCK_FRAGMENT_ORIGIN (block) == NULL_TREE)
4314 {
4315 BLOCK_FRAGMENT_CHAIN (block)
4316 = block_fragments_nreverse (BLOCK_FRAGMENT_CHAIN (block));
4317 if (!BLOCK_SAME_RANGE (BLOCK_FRAGMENT_CHAIN (block)))
4318 BLOCK_SAME_RANGE (block) = 0;
4319 }
4320 BLOCK_SUBBLOCKS (block) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block));
4321 prev = block;
4322 }
4323 return prev;
4324 }
4325
4326
4327 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
4328 and create duplicate blocks. */
4329 /* ??? Need an option to either create block fragments or to create
4330 abstract origin duplicates of a source block. It really depends
4331 on what optimization has been performed. */
4332
4333 void
4334 reorder_blocks (void)
4335 {
4336 tree block = DECL_INITIAL (current_function_decl);
4337
4338 if (block == NULL_TREE)
4339 return;
4340
4341 auto_vec<tree, 10> block_stack;
4342
4343 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
4344 clear_block_marks (block);
4345
4346 /* Prune the old trees away, so that they don't get in the way. */
4347 BLOCK_SUBBLOCKS (block) = NULL_TREE;
4348 BLOCK_CHAIN (block) = NULL_TREE;
4349
4350 /* Recreate the block tree from the note nesting. */
4351 reorder_blocks_1 (get_insns (), block, &block_stack);
4352 BLOCK_SUBBLOCKS (block) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block));
4353 }
4354
4355 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
4356
4357 void
4358 clear_block_marks (tree block)
4359 {
4360 while (block)
4361 {
4362 TREE_ASM_WRITTEN (block) = 0;
4363 clear_block_marks (BLOCK_SUBBLOCKS (block));
4364 block = BLOCK_CHAIN (block);
4365 }
4366 }
4367
4368 static void
4369 reorder_blocks_1 (rtx_insn *insns, tree current_block,
4370 vec<tree> *p_block_stack)
4371 {
4372 rtx_insn *insn;
4373 tree prev_beg = NULL_TREE, prev_end = NULL_TREE;
4374
4375 for (insn = insns; insn; insn = NEXT_INSN (insn))
4376 {
4377 if (NOTE_P (insn))
4378 {
4379 if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_BEG)
4380 {
4381 tree block = NOTE_BLOCK (insn);
4382 tree origin;
4383
4384 gcc_assert (BLOCK_FRAGMENT_ORIGIN (block) == NULL_TREE);
4385 origin = block;
4386
4387 if (prev_end)
4388 BLOCK_SAME_RANGE (prev_end) = 0;
4389 prev_end = NULL_TREE;
4390
4391 /* If we have seen this block before, that means it now
4392 spans multiple address regions. Create a new fragment. */
4393 if (TREE_ASM_WRITTEN (block))
4394 {
4395 tree new_block = copy_node (block);
4396
4397 BLOCK_SAME_RANGE (new_block) = 0;
4398 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
4399 BLOCK_FRAGMENT_CHAIN (new_block)
4400 = BLOCK_FRAGMENT_CHAIN (origin);
4401 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
4402
4403 NOTE_BLOCK (insn) = new_block;
4404 block = new_block;
4405 }
4406
4407 if (prev_beg == current_block && prev_beg)
4408 BLOCK_SAME_RANGE (block) = 1;
4409
4410 prev_beg = origin;
4411
4412 BLOCK_SUBBLOCKS (block) = 0;
4413 TREE_ASM_WRITTEN (block) = 1;
4414 /* When there's only one block for the entire function,
4415 current_block == block and we mustn't do this, it
4416 will cause infinite recursion. */
4417 if (block != current_block)
4418 {
4419 tree super;
4420 if (block != origin)
4421 gcc_assert (BLOCK_SUPERCONTEXT (origin) == current_block
4422 || BLOCK_FRAGMENT_ORIGIN (BLOCK_SUPERCONTEXT
4423 (origin))
4424 == current_block);
4425 if (p_block_stack->is_empty ())
4426 super = current_block;
4427 else
4428 {
4429 super = p_block_stack->last ();
4430 gcc_assert (super == current_block
4431 || BLOCK_FRAGMENT_ORIGIN (super)
4432 == current_block);
4433 }
4434 BLOCK_SUPERCONTEXT (block) = super;
4435 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
4436 BLOCK_SUBBLOCKS (current_block) = block;
4437 current_block = origin;
4438 }
4439 p_block_stack->safe_push (block);
4440 }
4441 else if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_END)
4442 {
4443 NOTE_BLOCK (insn) = p_block_stack->pop ();
4444 current_block = BLOCK_SUPERCONTEXT (current_block);
4445 if (BLOCK_FRAGMENT_ORIGIN (current_block))
4446 current_block = BLOCK_FRAGMENT_ORIGIN (current_block);
4447 prev_beg = NULL_TREE;
4448 prev_end = BLOCK_SAME_RANGE (NOTE_BLOCK (insn))
4449 ? NOTE_BLOCK (insn) : NULL_TREE;
4450 }
4451 }
4452 else
4453 {
4454 prev_beg = NULL_TREE;
4455 if (prev_end)
4456 BLOCK_SAME_RANGE (prev_end) = 0;
4457 prev_end = NULL_TREE;
4458 }
4459 }
4460 }
4461
4462 /* Reverse the order of elements in the chain T of blocks,
4463 and return the new head of the chain (old last element). */
4464
4465 tree
4466 blocks_nreverse (tree t)
4467 {
4468 tree prev = 0, block, next;
4469 for (block = t; block; block = next)
4470 {
4471 next = BLOCK_CHAIN (block);
4472 BLOCK_CHAIN (block) = prev;
4473 prev = block;
4474 }
4475 return prev;
4476 }
4477
4478 /* Concatenate two chains of blocks (chained through BLOCK_CHAIN)
4479 by modifying the last node in chain 1 to point to chain 2. */
4480
4481 tree
4482 block_chainon (tree op1, tree op2)
4483 {
4484 tree t1;
4485
4486 if (!op1)
4487 return op2;
4488 if (!op2)
4489 return op1;
4490
4491 for (t1 = op1; BLOCK_CHAIN (t1); t1 = BLOCK_CHAIN (t1))
4492 continue;
4493 BLOCK_CHAIN (t1) = op2;
4494
4495 #ifdef ENABLE_TREE_CHECKING
4496 {
4497 tree t2;
4498 for (t2 = op2; t2; t2 = BLOCK_CHAIN (t2))
4499 gcc_assert (t2 != t1);
4500 }
4501 #endif
4502
4503 return op1;
4504 }
4505
4506 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
4507 non-NULL, list them all into VECTOR, in a depth-first preorder
4508 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
4509 blocks. */
4510
4511 static int
4512 all_blocks (tree block, tree *vector)
4513 {
4514 int n_blocks = 0;
4515
4516 while (block)
4517 {
4518 TREE_ASM_WRITTEN (block) = 0;
4519
4520 /* Record this block. */
4521 if (vector)
4522 vector[n_blocks] = block;
4523
4524 ++n_blocks;
4525
4526 /* Record the subblocks, and their subblocks... */
4527 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
4528 vector ? vector + n_blocks : 0);
4529 block = BLOCK_CHAIN (block);
4530 }
4531
4532 return n_blocks;
4533 }
4534
4535 /* Return a vector containing all the blocks rooted at BLOCK. The
4536 number of elements in the vector is stored in N_BLOCKS_P. The
4537 vector is dynamically allocated; it is the caller's responsibility
4538 to call `free' on the pointer returned. */
4539
4540 static tree *
4541 get_block_vector (tree block, int *n_blocks_p)
4542 {
4543 tree *block_vector;
4544
4545 *n_blocks_p = all_blocks (block, NULL);
4546 block_vector = XNEWVEC (tree, *n_blocks_p);
4547 all_blocks (block, block_vector);
4548
4549 return block_vector;
4550 }
4551
4552 static GTY(()) int next_block_index = 2;
4553
4554 /* Set BLOCK_NUMBER for all the blocks in FN. */
4555
4556 void
4557 number_blocks (tree fn)
4558 {
4559 int i;
4560 int n_blocks;
4561 tree *block_vector;
4562
4563 /* For XCOFF debugging output, we start numbering the blocks
4564 from 1 within each function, rather than keeping a running
4565 count. */
4566 #if defined (XCOFF_DEBUGGING_INFO)
4567 if (write_symbols == XCOFF_DEBUG)
4568 next_block_index = 1;
4569 #endif
4570
4571 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
4572
4573 /* The top-level BLOCK isn't numbered at all. */
4574 for (i = 1; i < n_blocks; ++i)
4575 /* We number the blocks from two. */
4576 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
4577
4578 free (block_vector);
4579
4580 return;
4581 }
4582
4583 /* If VAR is present in a subblock of BLOCK, return the subblock. */
4584
4585 DEBUG_FUNCTION tree
4586 debug_find_var_in_block_tree (tree var, tree block)
4587 {
4588 tree t;
4589
4590 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
4591 if (t == var)
4592 return block;
4593
4594 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
4595 {
4596 tree ret = debug_find_var_in_block_tree (var, t);
4597 if (ret)
4598 return ret;
4599 }
4600
4601 return NULL_TREE;
4602 }
4603 \f
4604 /* Keep track of whether we're in a dummy function context. If we are,
4605 we don't want to invoke the set_current_function hook, because we'll
4606 get into trouble if the hook calls target_reinit () recursively or
4607 when the initial initialization is not yet complete. */
4608
4609 static bool in_dummy_function;
4610
4611 /* Invoke the target hook when setting cfun. Update the optimization options
4612 if the function uses different options than the default. */
4613
4614 static void
4615 invoke_set_current_function_hook (tree fndecl)
4616 {
4617 if (!in_dummy_function)
4618 {
4619 tree opts = ((fndecl)
4620 ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (fndecl)
4621 : optimization_default_node);
4622
4623 if (!opts)
4624 opts = optimization_default_node;
4625
4626 /* Change optimization options if needed. */
4627 if (optimization_current_node != opts)
4628 {
4629 optimization_current_node = opts;
4630 cl_optimization_restore (&global_options, TREE_OPTIMIZATION (opts));
4631 }
4632
4633 targetm.set_current_function (fndecl);
4634 this_fn_optabs = this_target_optabs;
4635
4636 /* Initialize global alignment variables after op. */
4637 parse_alignment_opts ();
4638
4639 if (opts != optimization_default_node)
4640 {
4641 init_tree_optimization_optabs (opts);
4642 if (TREE_OPTIMIZATION_OPTABS (opts))
4643 this_fn_optabs = (struct target_optabs *)
4644 TREE_OPTIMIZATION_OPTABS (opts);
4645 }
4646 }
4647 }
4648
4649 /* cfun should never be set directly; use this function. */
4650
4651 void
4652 set_cfun (struct function *new_cfun, bool force)
4653 {
4654 if (cfun != new_cfun || force)
4655 {
4656 cfun = new_cfun;
4657 invoke_set_current_function_hook (new_cfun ? new_cfun->decl : NULL_TREE);
4658 redirect_edge_var_map_empty ();
4659 }
4660 }
4661
4662 /* Initialized with NOGC, making this poisonous to the garbage collector. */
4663
4664 static vec<function *> cfun_stack;
4665
4666 /* Push the current cfun onto the stack, and set cfun to new_cfun. Also set
4667 current_function_decl accordingly. */
4668
4669 void
4670 push_cfun (struct function *new_cfun)
4671 {
4672 gcc_assert ((!cfun && !current_function_decl)
4673 || (cfun && current_function_decl == cfun->decl));
4674 cfun_stack.safe_push (cfun);
4675 current_function_decl = new_cfun ? new_cfun->decl : NULL_TREE;
4676 set_cfun (new_cfun);
4677 }
4678
4679 /* Pop cfun from the stack. Also set current_function_decl accordingly. */
4680
4681 void
4682 pop_cfun (void)
4683 {
4684 struct function *new_cfun = cfun_stack.pop ();
4685 /* When in_dummy_function, we do have a cfun but current_function_decl is
4686 NULL. We also allow pushing NULL cfun and subsequently changing
4687 current_function_decl to something else and have both restored by
4688 pop_cfun. */
4689 gcc_checking_assert (in_dummy_function
4690 || !cfun
4691 || current_function_decl == cfun->decl);
4692 set_cfun (new_cfun);
4693 current_function_decl = new_cfun ? new_cfun->decl : NULL_TREE;
4694 }
4695
4696 /* Return value of funcdef and increase it. */
4697 int
4698 get_next_funcdef_no (void)
4699 {
4700 return funcdef_no++;
4701 }
4702
4703 /* Return value of funcdef. */
4704 int
4705 get_last_funcdef_no (void)
4706 {
4707 return funcdef_no;
4708 }
4709
4710 /* Allocate a function structure for FNDECL and set its contents
4711 to the defaults. Set cfun to the newly-allocated object.
4712 Some of the helper functions invoked during initialization assume
4713 that cfun has already been set. Therefore, assign the new object
4714 directly into cfun and invoke the back end hook explicitly at the
4715 very end, rather than initializing a temporary and calling set_cfun
4716 on it.
4717
4718 ABSTRACT_P is true if this is a function that will never be seen by
4719 the middle-end. Such functions are front-end concepts (like C++
4720 function templates) that do not correspond directly to functions
4721 placed in object files. */
4722
4723 void
4724 allocate_struct_function (tree fndecl, bool abstract_p)
4725 {
4726 tree fntype = fndecl ? TREE_TYPE (fndecl) : NULL_TREE;
4727
4728 cfun = ggc_cleared_alloc<function> ();
4729
4730 init_eh_for_function ();
4731
4732 if (init_machine_status)
4733 cfun->machine = (*init_machine_status) ();
4734
4735 #ifdef OVERRIDE_ABI_FORMAT
4736 OVERRIDE_ABI_FORMAT (fndecl);
4737 #endif
4738
4739 if (fndecl != NULL_TREE)
4740 {
4741 DECL_STRUCT_FUNCTION (fndecl) = cfun;
4742 cfun->decl = fndecl;
4743 current_function_funcdef_no = get_next_funcdef_no ();
4744 }
4745
4746 invoke_set_current_function_hook (fndecl);
4747
4748 if (fndecl != NULL_TREE)
4749 {
4750 tree result = DECL_RESULT (fndecl);
4751
4752 if (!abstract_p)
4753 {
4754 /* Now that we have activated any function-specific attributes
4755 that might affect layout, particularly vector modes, relayout
4756 each of the parameters and the result. */
4757 relayout_decl (result);
4758 for (tree parm = DECL_ARGUMENTS (fndecl); parm;
4759 parm = DECL_CHAIN (parm))
4760 relayout_decl (parm);
4761
4762 /* Similarly relayout the function decl. */
4763 targetm.target_option.relayout_function (fndecl);
4764 }
4765
4766 if (!abstract_p && aggregate_value_p (result, fndecl))
4767 {
4768 #ifdef PCC_STATIC_STRUCT_RETURN
4769 cfun->returns_pcc_struct = 1;
4770 #endif
4771 cfun->returns_struct = 1;
4772 }
4773
4774 cfun->stdarg = stdarg_p (fntype);
4775
4776 /* Assume all registers in stdarg functions need to be saved. */
4777 cfun->va_list_gpr_size = VA_LIST_MAX_GPR_SIZE;
4778 cfun->va_list_fpr_size = VA_LIST_MAX_FPR_SIZE;
4779
4780 /* ??? This could be set on a per-function basis by the front-end
4781 but is this worth the hassle? */
4782 cfun->can_throw_non_call_exceptions = flag_non_call_exceptions;
4783 cfun->can_delete_dead_exceptions = flag_delete_dead_exceptions;
4784
4785 if (!profile_flag && !flag_instrument_function_entry_exit)
4786 DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl) = 1;
4787 }
4788
4789 /* Don't enable begin stmt markers if var-tracking at assignments is
4790 disabled. The markers make little sense without the variable
4791 binding annotations among them. */
4792 cfun->debug_nonbind_markers = lang_hooks.emits_begin_stmt
4793 && MAY_HAVE_DEBUG_MARKER_STMTS;
4794 }
4795
4796 /* This is like allocate_struct_function, but pushes a new cfun for FNDECL
4797 instead of just setting it. */
4798
4799 void
4800 push_struct_function (tree fndecl)
4801 {
4802 /* When in_dummy_function we might be in the middle of a pop_cfun and
4803 current_function_decl and cfun may not match. */
4804 gcc_assert (in_dummy_function
4805 || (!cfun && !current_function_decl)
4806 || (cfun && current_function_decl == cfun->decl));
4807 cfun_stack.safe_push (cfun);
4808 current_function_decl = fndecl;
4809 allocate_struct_function (fndecl, false);
4810 }
4811
4812 /* Reset crtl and other non-struct-function variables to defaults as
4813 appropriate for emitting rtl at the start of a function. */
4814
4815 static void
4816 prepare_function_start (void)
4817 {
4818 gcc_assert (!get_last_insn ());
4819 init_temp_slots ();
4820 init_emit ();
4821 init_varasm_status ();
4822 init_expr ();
4823 default_rtl_profile ();
4824
4825 if (flag_stack_usage_info)
4826 {
4827 cfun->su = ggc_cleared_alloc<stack_usage> ();
4828 cfun->su->static_stack_size = -1;
4829 }
4830
4831 cse_not_expected = ! optimize;
4832
4833 /* Caller save not needed yet. */
4834 caller_save_needed = 0;
4835
4836 /* We haven't done register allocation yet. */
4837 reg_renumber = 0;
4838
4839 /* Indicate that we have not instantiated virtual registers yet. */
4840 virtuals_instantiated = 0;
4841
4842 /* Indicate that we want CONCATs now. */
4843 generating_concat_p = 1;
4844
4845 /* Indicate we have no need of a frame pointer yet. */
4846 frame_pointer_needed = 0;
4847 }
4848
4849 void
4850 push_dummy_function (bool with_decl)
4851 {
4852 tree fn_decl, fn_type, fn_result_decl;
4853
4854 gcc_assert (!in_dummy_function);
4855 in_dummy_function = true;
4856
4857 if (with_decl)
4858 {
4859 fn_type = build_function_type_list (void_type_node, NULL_TREE);
4860 fn_decl = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL, NULL_TREE,
4861 fn_type);
4862 fn_result_decl = build_decl (UNKNOWN_LOCATION, RESULT_DECL,
4863 NULL_TREE, void_type_node);
4864 DECL_RESULT (fn_decl) = fn_result_decl;
4865 }
4866 else
4867 fn_decl = NULL_TREE;
4868
4869 push_struct_function (fn_decl);
4870 }
4871
4872 /* Initialize the rtl expansion mechanism so that we can do simple things
4873 like generate sequences. This is used to provide a context during global
4874 initialization of some passes. You must call expand_dummy_function_end
4875 to exit this context. */
4876
4877 void
4878 init_dummy_function_start (void)
4879 {
4880 push_dummy_function (false);
4881 prepare_function_start ();
4882 }
4883
4884 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
4885 and initialize static variables for generating RTL for the statements
4886 of the function. */
4887
4888 void
4889 init_function_start (tree subr)
4890 {
4891 /* Initialize backend, if needed. */
4892 initialize_rtl ();
4893
4894 prepare_function_start ();
4895 decide_function_section (subr);
4896
4897 /* Warn if this value is an aggregate type,
4898 regardless of which calling convention we are using for it. */
4899 if (AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
4900 warning (OPT_Waggregate_return, "function returns an aggregate");
4901 }
4902
4903 /* Expand code to verify the stack_protect_guard. This is invoked at
4904 the end of a function to be protected. */
4905
4906 void
4907 stack_protect_epilogue (void)
4908 {
4909 tree guard_decl = crtl->stack_protect_guard_decl;
4910 rtx_code_label *label = gen_label_rtx ();
4911 rtx x, y;
4912 rtx_insn *seq = NULL;
4913
4914 x = expand_normal (crtl->stack_protect_guard);
4915
4916 if (targetm.have_stack_protect_combined_test () && guard_decl)
4917 {
4918 gcc_assert (DECL_P (guard_decl));
4919 y = DECL_RTL (guard_decl);
4920 /* Allow the target to compute address of Y and compare it with X without
4921 leaking Y into a register. This combined address + compare pattern
4922 allows the target to prevent spilling of any intermediate results by
4923 splitting it after register allocator. */
4924 seq = targetm.gen_stack_protect_combined_test (x, y, label);
4925 }
4926 else
4927 {
4928 if (guard_decl)
4929 y = expand_normal (guard_decl);
4930 else
4931 y = const0_rtx;
4932
4933 /* Allow the target to compare Y with X without leaking either into
4934 a register. */
4935 if (targetm.have_stack_protect_test ())
4936 seq = targetm.gen_stack_protect_test (x, y, label);
4937 }
4938
4939 if (seq)
4940 emit_insn (seq);
4941 else
4942 emit_cmp_and_jump_insns (x, y, EQ, NULL_RTX, ptr_mode, 1, label);
4943
4944 /* The noreturn predictor has been moved to the tree level. The rtl-level
4945 predictors estimate this branch about 20%, which isn't enough to get
4946 things moved out of line. Since this is the only extant case of adding
4947 a noreturn function at the rtl level, it doesn't seem worth doing ought
4948 except adding the prediction by hand. */
4949 rtx_insn *tmp = get_last_insn ();
4950 if (JUMP_P (tmp))
4951 predict_insn_def (tmp, PRED_NORETURN, TAKEN);
4952
4953 expand_call (targetm.stack_protect_fail (), NULL_RTX, /*ignore=*/true);
4954 free_temp_slots ();
4955 emit_label (label);
4956 }
4957 \f
4958 /* Start the RTL for a new function, and set variables used for
4959 emitting RTL.
4960 SUBR is the FUNCTION_DECL node.
4961 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
4962 the function's parameters, which must be run at any return statement. */
4963
4964 void
4965 expand_function_start (tree subr)
4966 {
4967 /* Make sure volatile mem refs aren't considered
4968 valid operands of arithmetic insns. */
4969 init_recog_no_volatile ();
4970
4971 crtl->profile
4972 = (profile_flag
4973 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
4974
4975 crtl->limit_stack
4976 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
4977
4978 /* Make the label for return statements to jump to. Do not special
4979 case machines with special return instructions -- they will be
4980 handled later during jump, ifcvt, or epilogue creation. */
4981 return_label = gen_label_rtx ();
4982
4983 /* Initialize rtx used to return the value. */
4984 /* Do this before assign_parms so that we copy the struct value address
4985 before any library calls that assign parms might generate. */
4986
4987 /* Decide whether to return the value in memory or in a register. */
4988 tree res = DECL_RESULT (subr);
4989 if (aggregate_value_p (res, subr))
4990 {
4991 /* Returning something that won't go in a register. */
4992 rtx value_address = 0;
4993
4994 #ifdef PCC_STATIC_STRUCT_RETURN
4995 if (cfun->returns_pcc_struct)
4996 {
4997 int size = int_size_in_bytes (TREE_TYPE (res));
4998 value_address = assemble_static_space (size);
4999 }
5000 else
5001 #endif
5002 {
5003 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 2);
5004 /* Expect to be passed the address of a place to store the value.
5005 If it is passed as an argument, assign_parms will take care of
5006 it. */
5007 if (sv)
5008 {
5009 value_address = gen_reg_rtx (Pmode);
5010 emit_move_insn (value_address, sv);
5011 }
5012 }
5013 if (value_address)
5014 {
5015 rtx x = value_address;
5016 if (!DECL_BY_REFERENCE (res))
5017 {
5018 x = gen_rtx_MEM (DECL_MODE (res), x);
5019 set_mem_attributes (x, res, 1);
5020 }
5021 set_parm_rtl (res, x);
5022 }
5023 }
5024 else if (DECL_MODE (res) == VOIDmode)
5025 /* If return mode is void, this decl rtl should not be used. */
5026 set_parm_rtl (res, NULL_RTX);
5027 else
5028 {
5029 /* Compute the return values into a pseudo reg, which we will copy
5030 into the true return register after the cleanups are done. */
5031 tree return_type = TREE_TYPE (res);
5032
5033 /* If we may coalesce this result, make sure it has the expected mode
5034 in case it was promoted. But we need not bother about BLKmode. */
5035 machine_mode promoted_mode
5036 = flag_tree_coalesce_vars && is_gimple_reg (res)
5037 ? promote_ssa_mode (ssa_default_def (cfun, res), NULL)
5038 : BLKmode;
5039
5040 if (promoted_mode != BLKmode)
5041 set_parm_rtl (res, gen_reg_rtx (promoted_mode));
5042 else if (TYPE_MODE (return_type) != BLKmode
5043 && targetm.calls.return_in_msb (return_type))
5044 /* expand_function_end will insert the appropriate padding in
5045 this case. Use the return value's natural (unpadded) mode
5046 within the function proper. */
5047 set_parm_rtl (res, gen_reg_rtx (TYPE_MODE (return_type)));
5048 else
5049 {
5050 /* In order to figure out what mode to use for the pseudo, we
5051 figure out what the mode of the eventual return register will
5052 actually be, and use that. */
5053 rtx hard_reg = hard_function_value (return_type, subr, 0, 1);
5054
5055 /* Structures that are returned in registers are not
5056 aggregate_value_p, so we may see a PARALLEL or a REG. */
5057 if (REG_P (hard_reg))
5058 set_parm_rtl (res, gen_reg_rtx (GET_MODE (hard_reg)));
5059 else
5060 {
5061 gcc_assert (GET_CODE (hard_reg) == PARALLEL);
5062 set_parm_rtl (res, gen_group_rtx (hard_reg));
5063 }
5064 }
5065
5066 /* Set DECL_REGISTER flag so that expand_function_end will copy the
5067 result to the real return register(s). */
5068 DECL_REGISTER (res) = 1;
5069 }
5070
5071 /* Initialize rtx for parameters and local variables.
5072 In some cases this requires emitting insns. */
5073 assign_parms (subr);
5074
5075 /* If function gets a static chain arg, store it. */
5076 if (cfun->static_chain_decl)
5077 {
5078 tree parm = cfun->static_chain_decl;
5079 rtx local, chain;
5080 rtx_insn *insn;
5081 int unsignedp;
5082
5083 local = gen_reg_rtx (promote_decl_mode (parm, &unsignedp));
5084 chain = targetm.calls.static_chain (current_function_decl, true);
5085
5086 set_decl_incoming_rtl (parm, chain, false);
5087 set_parm_rtl (parm, local);
5088 mark_reg_pointer (local, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
5089
5090 if (GET_MODE (local) != GET_MODE (chain))
5091 {
5092 convert_move (local, chain, unsignedp);
5093 insn = get_last_insn ();
5094 }
5095 else
5096 insn = emit_move_insn (local, chain);
5097
5098 /* Mark the register as eliminable, similar to parameters. */
5099 if (MEM_P (chain)
5100 && reg_mentioned_p (arg_pointer_rtx, XEXP (chain, 0)))
5101 set_dst_reg_note (insn, REG_EQUIV, chain, local);
5102
5103 /* If we aren't optimizing, save the static chain onto the stack. */
5104 if (!optimize)
5105 {
5106 tree saved_static_chain_decl
5107 = build_decl (DECL_SOURCE_LOCATION (parm), VAR_DECL,
5108 DECL_NAME (parm), TREE_TYPE (parm));
5109 rtx saved_static_chain_rtx
5110 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
5111 SET_DECL_RTL (saved_static_chain_decl, saved_static_chain_rtx);
5112 emit_move_insn (saved_static_chain_rtx, chain);
5113 SET_DECL_VALUE_EXPR (parm, saved_static_chain_decl);
5114 DECL_HAS_VALUE_EXPR_P (parm) = 1;
5115 }
5116 }
5117
5118 /* The following was moved from init_function_start.
5119 The move was supposed to make sdb output more accurate. */
5120 /* Indicate the beginning of the function body,
5121 as opposed to parm setup. */
5122 emit_note (NOTE_INSN_FUNCTION_BEG);
5123
5124 gcc_assert (NOTE_P (get_last_insn ()));
5125
5126 parm_birth_insn = get_last_insn ();
5127
5128 /* If the function receives a non-local goto, then store the
5129 bits we need to restore the frame pointer. */
5130 if (cfun->nonlocal_goto_save_area)
5131 {
5132 tree t_save;
5133 rtx r_save;
5134
5135 tree var = TREE_OPERAND (cfun->nonlocal_goto_save_area, 0);
5136 gcc_assert (DECL_RTL_SET_P (var));
5137
5138 t_save = build4 (ARRAY_REF,
5139 TREE_TYPE (TREE_TYPE (cfun->nonlocal_goto_save_area)),
5140 cfun->nonlocal_goto_save_area,
5141 integer_zero_node, NULL_TREE, NULL_TREE);
5142 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
5143 gcc_assert (GET_MODE (r_save) == Pmode);
5144
5145 emit_move_insn (r_save, targetm.builtin_setjmp_frame_value ());
5146 update_nonlocal_goto_save_area ();
5147 }
5148
5149 if (crtl->profile)
5150 {
5151 #ifdef PROFILE_HOOK
5152 PROFILE_HOOK (current_function_funcdef_no);
5153 #endif
5154 }
5155
5156 /* If we are doing generic stack checking, the probe should go here. */
5157 if (flag_stack_check == GENERIC_STACK_CHECK)
5158 stack_check_probe_note = emit_note (NOTE_INSN_DELETED);
5159 }
5160 \f
5161 void
5162 pop_dummy_function (void)
5163 {
5164 pop_cfun ();
5165 in_dummy_function = false;
5166 }
5167
5168 /* Undo the effects of init_dummy_function_start. */
5169 void
5170 expand_dummy_function_end (void)
5171 {
5172 gcc_assert (in_dummy_function);
5173
5174 /* End any sequences that failed to be closed due to syntax errors. */
5175 while (in_sequence_p ())
5176 end_sequence ();
5177
5178 /* Outside function body, can't compute type's actual size
5179 until next function's body starts. */
5180
5181 free_after_parsing (cfun);
5182 free_after_compilation (cfun);
5183 pop_dummy_function ();
5184 }
5185
5186 /* Helper for diddle_return_value. */
5187
5188 void
5189 diddle_return_value_1 (void (*doit) (rtx, void *), void *arg, rtx outgoing)
5190 {
5191 if (! outgoing)
5192 return;
5193
5194 if (REG_P (outgoing))
5195 (*doit) (outgoing, arg);
5196 else if (GET_CODE (outgoing) == PARALLEL)
5197 {
5198 int i;
5199
5200 for (i = 0; i < XVECLEN (outgoing, 0); i++)
5201 {
5202 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
5203
5204 if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
5205 (*doit) (x, arg);
5206 }
5207 }
5208 }
5209
5210 /* Call DOIT for each hard register used as a return value from
5211 the current function. */
5212
5213 void
5214 diddle_return_value (void (*doit) (rtx, void *), void *arg)
5215 {
5216 diddle_return_value_1 (doit, arg, crtl->return_rtx);
5217 }
5218
5219 static void
5220 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
5221 {
5222 emit_clobber (reg);
5223 }
5224
5225 void
5226 clobber_return_register (void)
5227 {
5228 diddle_return_value (do_clobber_return_reg, NULL);
5229
5230 /* In case we do use pseudo to return value, clobber it too. */
5231 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
5232 {
5233 tree decl_result = DECL_RESULT (current_function_decl);
5234 rtx decl_rtl = DECL_RTL (decl_result);
5235 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
5236 {
5237 do_clobber_return_reg (decl_rtl, NULL);
5238 }
5239 }
5240 }
5241
5242 static void
5243 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
5244 {
5245 emit_use (reg);
5246 }
5247
5248 static void
5249 use_return_register (void)
5250 {
5251 diddle_return_value (do_use_return_reg, NULL);
5252 }
5253
5254 /* Set the location of the insn chain starting at INSN to LOC. */
5255
5256 static void
5257 set_insn_locations (rtx_insn *insn, int loc)
5258 {
5259 while (insn != NULL)
5260 {
5261 if (INSN_P (insn))
5262 INSN_LOCATION (insn) = loc;
5263 insn = NEXT_INSN (insn);
5264 }
5265 }
5266
5267 /* Generate RTL for the end of the current function. */
5268
5269 void
5270 expand_function_end (void)
5271 {
5272 /* If arg_pointer_save_area was referenced only from a nested
5273 function, we will not have initialized it yet. Do that now. */
5274 if (arg_pointer_save_area && ! crtl->arg_pointer_save_area_init)
5275 get_arg_pointer_save_area ();
5276
5277 /* If we are doing generic stack checking and this function makes calls,
5278 do a stack probe at the start of the function to ensure we have enough
5279 space for another stack frame. */
5280 if (flag_stack_check == GENERIC_STACK_CHECK)
5281 {
5282 rtx_insn *insn, *seq;
5283
5284 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
5285 if (CALL_P (insn))
5286 {
5287 rtx max_frame_size = GEN_INT (STACK_CHECK_MAX_FRAME_SIZE);
5288 start_sequence ();
5289 if (STACK_CHECK_MOVING_SP)
5290 anti_adjust_stack_and_probe (max_frame_size, true);
5291 else
5292 probe_stack_range (STACK_OLD_CHECK_PROTECT, max_frame_size);
5293 seq = get_insns ();
5294 end_sequence ();
5295 set_insn_locations (seq, prologue_location);
5296 emit_insn_before (seq, stack_check_probe_note);
5297 break;
5298 }
5299 }
5300
5301 /* End any sequences that failed to be closed due to syntax errors. */
5302 while (in_sequence_p ())
5303 end_sequence ();
5304
5305 clear_pending_stack_adjust ();
5306 do_pending_stack_adjust ();
5307
5308 /* Output a linenumber for the end of the function.
5309 SDB depended on this. */
5310 set_curr_insn_location (input_location);
5311
5312 /* Before the return label (if any), clobber the return
5313 registers so that they are not propagated live to the rest of
5314 the function. This can only happen with functions that drop
5315 through; if there had been a return statement, there would
5316 have either been a return rtx, or a jump to the return label.
5317
5318 We delay actual code generation after the current_function_value_rtx
5319 is computed. */
5320 rtx_insn *clobber_after = get_last_insn ();
5321
5322 /* Output the label for the actual return from the function. */
5323 emit_label (return_label);
5324
5325 if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ)
5326 {
5327 /* Let except.c know where it should emit the call to unregister
5328 the function context for sjlj exceptions. */
5329 if (flag_exceptions)
5330 sjlj_emit_function_exit_after (get_last_insn ());
5331 }
5332
5333 /* If this is an implementation of throw, do what's necessary to
5334 communicate between __builtin_eh_return and the epilogue. */
5335 expand_eh_return ();
5336
5337 /* If stack protection is enabled for this function, check the guard. */
5338 if (crtl->stack_protect_guard
5339 && targetm.stack_protect_runtime_enabled_p ()
5340 && naked_return_label == NULL_RTX)
5341 stack_protect_epilogue ();
5342
5343 /* If scalar return value was computed in a pseudo-reg, or was a named
5344 return value that got dumped to the stack, copy that to the hard
5345 return register. */
5346 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
5347 {
5348 tree decl_result = DECL_RESULT (current_function_decl);
5349 rtx decl_rtl = DECL_RTL (decl_result);
5350
5351 if (REG_P (decl_rtl)
5352 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
5353 : DECL_REGISTER (decl_result))
5354 {
5355 rtx real_decl_rtl = crtl->return_rtx;
5356 complex_mode cmode;
5357
5358 /* This should be set in assign_parms. */
5359 gcc_assert (REG_FUNCTION_VALUE_P (real_decl_rtl));
5360
5361 /* If this is a BLKmode structure being returned in registers,
5362 then use the mode computed in expand_return. Note that if
5363 decl_rtl is memory, then its mode may have been changed,
5364 but that crtl->return_rtx has not. */
5365 if (GET_MODE (real_decl_rtl) == BLKmode)
5366 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
5367
5368 /* If a non-BLKmode return value should be padded at the least
5369 significant end of the register, shift it left by the appropriate
5370 amount. BLKmode results are handled using the group load/store
5371 machinery. */
5372 if (TYPE_MODE (TREE_TYPE (decl_result)) != BLKmode
5373 && REG_P (real_decl_rtl)
5374 && targetm.calls.return_in_msb (TREE_TYPE (decl_result)))
5375 {
5376 emit_move_insn (gen_rtx_REG (GET_MODE (decl_rtl),
5377 REGNO (real_decl_rtl)),
5378 decl_rtl);
5379 shift_return_value (GET_MODE (decl_rtl), true, real_decl_rtl);
5380 }
5381 else if (GET_CODE (real_decl_rtl) == PARALLEL)
5382 {
5383 /* If expand_function_start has created a PARALLEL for decl_rtl,
5384 move the result to the real return registers. Otherwise, do
5385 a group load from decl_rtl for a named return. */
5386 if (GET_CODE (decl_rtl) == PARALLEL)
5387 emit_group_move (real_decl_rtl, decl_rtl);
5388 else
5389 emit_group_load (real_decl_rtl, decl_rtl,
5390 TREE_TYPE (decl_result),
5391 int_size_in_bytes (TREE_TYPE (decl_result)));
5392 }
5393 /* In the case of complex integer modes smaller than a word, we'll
5394 need to generate some non-trivial bitfield insertions. Do that
5395 on a pseudo and not the hard register. */
5396 else if (GET_CODE (decl_rtl) == CONCAT
5397 && is_complex_int_mode (GET_MODE (decl_rtl), &cmode)
5398 && GET_MODE_BITSIZE (cmode) <= BITS_PER_WORD)
5399 {
5400 int old_generating_concat_p;
5401 rtx tmp;
5402
5403 old_generating_concat_p = generating_concat_p;
5404 generating_concat_p = 0;
5405 tmp = gen_reg_rtx (GET_MODE (decl_rtl));
5406 generating_concat_p = old_generating_concat_p;
5407
5408 emit_move_insn (tmp, decl_rtl);
5409 emit_move_insn (real_decl_rtl, tmp);
5410 }
5411 /* If a named return value dumped decl_return to memory, then
5412 we may need to re-do the PROMOTE_MODE signed/unsigned
5413 extension. */
5414 else if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
5415 {
5416 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
5417 promote_function_mode (TREE_TYPE (decl_result),
5418 GET_MODE (decl_rtl), &unsignedp,
5419 TREE_TYPE (current_function_decl), 1);
5420
5421 convert_move (real_decl_rtl, decl_rtl, unsignedp);
5422 }
5423 else
5424 emit_move_insn (real_decl_rtl, decl_rtl);
5425 }
5426 }
5427
5428 /* If returning a structure, arrange to return the address of the value
5429 in a place where debuggers expect to find it.
5430
5431 If returning a structure PCC style,
5432 the caller also depends on this value.
5433 And cfun->returns_pcc_struct is not necessarily set. */
5434 if ((cfun->returns_struct || cfun->returns_pcc_struct)
5435 && !targetm.calls.omit_struct_return_reg)
5436 {
5437 rtx value_address = DECL_RTL (DECL_RESULT (current_function_decl));
5438 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
5439 rtx outgoing;
5440
5441 if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
5442 type = TREE_TYPE (type);
5443 else
5444 value_address = XEXP (value_address, 0);
5445
5446 outgoing = targetm.calls.function_value (build_pointer_type (type),
5447 current_function_decl, true);
5448
5449 /* Mark this as a function return value so integrate will delete the
5450 assignment and USE below when inlining this function. */
5451 REG_FUNCTION_VALUE_P (outgoing) = 1;
5452
5453 /* The address may be ptr_mode and OUTGOING may be Pmode. */
5454 scalar_int_mode mode = as_a <scalar_int_mode> (GET_MODE (outgoing));
5455 value_address = convert_memory_address (mode, value_address);
5456
5457 emit_move_insn (outgoing, value_address);
5458
5459 /* Show return register used to hold result (in this case the address
5460 of the result. */
5461 crtl->return_rtx = outgoing;
5462 }
5463
5464 /* Emit the actual code to clobber return register. Don't emit
5465 it if clobber_after is a barrier, then the previous basic block
5466 certainly doesn't fall thru into the exit block. */
5467 if (!BARRIER_P (clobber_after))
5468 {
5469 start_sequence ();
5470 clobber_return_register ();
5471 rtx_insn *seq = get_insns ();
5472 end_sequence ();
5473
5474 emit_insn_after (seq, clobber_after);
5475 }
5476
5477 /* Output the label for the naked return from the function. */
5478 if (naked_return_label)
5479 emit_label (naked_return_label);
5480
5481 /* @@@ This is a kludge. We want to ensure that instructions that
5482 may trap are not moved into the epilogue by scheduling, because
5483 we don't always emit unwind information for the epilogue. */
5484 if (cfun->can_throw_non_call_exceptions
5485 && targetm_common.except_unwind_info (&global_options) != UI_SJLJ)
5486 emit_insn (gen_blockage ());
5487
5488 /* If stack protection is enabled for this function, check the guard. */
5489 if (crtl->stack_protect_guard
5490 && targetm.stack_protect_runtime_enabled_p ()
5491 && naked_return_label)
5492 stack_protect_epilogue ();
5493
5494 /* If we had calls to alloca, and this machine needs
5495 an accurate stack pointer to exit the function,
5496 insert some code to save and restore the stack pointer. */
5497 if (! EXIT_IGNORE_STACK
5498 && cfun->calls_alloca)
5499 {
5500 rtx tem = 0;
5501
5502 start_sequence ();
5503 emit_stack_save (SAVE_FUNCTION, &tem);
5504 rtx_insn *seq = get_insns ();
5505 end_sequence ();
5506 emit_insn_before (seq, parm_birth_insn);
5507
5508 emit_stack_restore (SAVE_FUNCTION, tem);
5509 }
5510
5511 /* ??? This should no longer be necessary since stupid is no longer with
5512 us, but there are some parts of the compiler (eg reload_combine, and
5513 sh mach_dep_reorg) that still try and compute their own lifetime info
5514 instead of using the general framework. */
5515 use_return_register ();
5516 }
5517
5518 rtx
5519 get_arg_pointer_save_area (void)
5520 {
5521 rtx ret = arg_pointer_save_area;
5522
5523 if (! ret)
5524 {
5525 ret = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
5526 arg_pointer_save_area = ret;
5527 }
5528
5529 if (! crtl->arg_pointer_save_area_init)
5530 {
5531 /* Save the arg pointer at the beginning of the function. The
5532 generated stack slot may not be a valid memory address, so we
5533 have to check it and fix it if necessary. */
5534 start_sequence ();
5535 emit_move_insn (validize_mem (copy_rtx (ret)),
5536 crtl->args.internal_arg_pointer);
5537 rtx_insn *seq = get_insns ();
5538 end_sequence ();
5539
5540 push_topmost_sequence ();
5541 emit_insn_after (seq, entry_of_function ());
5542 pop_topmost_sequence ();
5543
5544 crtl->arg_pointer_save_area_init = true;
5545 }
5546
5547 return ret;
5548 }
5549 \f
5550
5551 /* If debugging dumps are requested, dump information about how the
5552 target handled -fstack-check=clash for the prologue.
5553
5554 PROBES describes what if any probes were emitted.
5555
5556 RESIDUALS indicates if the prologue had any residual allocation
5557 (i.e. total allocation was not a multiple of PROBE_INTERVAL). */
5558
5559 void
5560 dump_stack_clash_frame_info (enum stack_clash_probes probes, bool residuals)
5561 {
5562 if (!dump_file)
5563 return;
5564
5565 switch (probes)
5566 {
5567 case NO_PROBE_NO_FRAME:
5568 fprintf (dump_file,
5569 "Stack clash no probe no stack adjustment in prologue.\n");
5570 break;
5571 case NO_PROBE_SMALL_FRAME:
5572 fprintf (dump_file,
5573 "Stack clash no probe small stack adjustment in prologue.\n");
5574 break;
5575 case PROBE_INLINE:
5576 fprintf (dump_file, "Stack clash inline probes in prologue.\n");
5577 break;
5578 case PROBE_LOOP:
5579 fprintf (dump_file, "Stack clash probe loop in prologue.\n");
5580 break;
5581 }
5582
5583 if (residuals)
5584 fprintf (dump_file, "Stack clash residual allocation in prologue.\n");
5585 else
5586 fprintf (dump_file, "Stack clash no residual allocation in prologue.\n");
5587
5588 if (frame_pointer_needed)
5589 fprintf (dump_file, "Stack clash frame pointer needed.\n");
5590 else
5591 fprintf (dump_file, "Stack clash no frame pointer needed.\n");
5592
5593 if (TREE_THIS_VOLATILE (cfun->decl))
5594 fprintf (dump_file,
5595 "Stack clash noreturn prologue, assuming no implicit"
5596 " probes in caller.\n");
5597 else
5598 fprintf (dump_file,
5599 "Stack clash not noreturn prologue.\n");
5600 }
5601
5602 /* Add a list of INSNS to the hash HASHP, possibly allocating HASHP
5603 for the first time. */
5604
5605 static void
5606 record_insns (rtx_insn *insns, rtx end, hash_table<insn_cache_hasher> **hashp)
5607 {
5608 rtx_insn *tmp;
5609 hash_table<insn_cache_hasher> *hash = *hashp;
5610
5611 if (hash == NULL)
5612 *hashp = hash = hash_table<insn_cache_hasher>::create_ggc (17);
5613
5614 for (tmp = insns; tmp != end; tmp = NEXT_INSN (tmp))
5615 {
5616 rtx *slot = hash->find_slot (tmp, INSERT);
5617 gcc_assert (*slot == NULL);
5618 *slot = tmp;
5619 }
5620 }
5621
5622 /* INSN has been duplicated or replaced by as COPY, perhaps by duplicating a
5623 basic block, splitting or peepholes. If INSN is a prologue or epilogue
5624 insn, then record COPY as well. */
5625
5626 void
5627 maybe_copy_prologue_epilogue_insn (rtx insn, rtx copy)
5628 {
5629 hash_table<insn_cache_hasher> *hash;
5630 rtx *slot;
5631
5632 hash = epilogue_insn_hash;
5633 if (!hash || !hash->find (insn))
5634 {
5635 hash = prologue_insn_hash;
5636 if (!hash || !hash->find (insn))
5637 return;
5638 }
5639
5640 slot = hash->find_slot (copy, INSERT);
5641 gcc_assert (*slot == NULL);
5642 *slot = copy;
5643 }
5644
5645 /* Determine if any INSNs in HASH are, or are part of, INSN. Because
5646 we can be running after reorg, SEQUENCE rtl is possible. */
5647
5648 static bool
5649 contains (const rtx_insn *insn, hash_table<insn_cache_hasher> *hash)
5650 {
5651 if (hash == NULL)
5652 return false;
5653
5654 if (NONJUMP_INSN_P (insn) && GET_CODE (PATTERN (insn)) == SEQUENCE)
5655 {
5656 rtx_sequence *seq = as_a <rtx_sequence *> (PATTERN (insn));
5657 int i;
5658 for (i = seq->len () - 1; i >= 0; i--)
5659 if (hash->find (seq->element (i)))
5660 return true;
5661 return false;
5662 }
5663
5664 return hash->find (const_cast<rtx_insn *> (insn)) != NULL;
5665 }
5666
5667 int
5668 prologue_contains (const rtx_insn *insn)
5669 {
5670 return contains (insn, prologue_insn_hash);
5671 }
5672
5673 int
5674 epilogue_contains (const rtx_insn *insn)
5675 {
5676 return contains (insn, epilogue_insn_hash);
5677 }
5678
5679 int
5680 prologue_epilogue_contains (const rtx_insn *insn)
5681 {
5682 if (contains (insn, prologue_insn_hash))
5683 return 1;
5684 if (contains (insn, epilogue_insn_hash))
5685 return 1;
5686 return 0;
5687 }
5688
5689 void
5690 record_prologue_seq (rtx_insn *seq)
5691 {
5692 record_insns (seq, NULL, &prologue_insn_hash);
5693 }
5694
5695 void
5696 record_epilogue_seq (rtx_insn *seq)
5697 {
5698 record_insns (seq, NULL, &epilogue_insn_hash);
5699 }
5700
5701 /* Set JUMP_LABEL for a return insn. */
5702
5703 void
5704 set_return_jump_label (rtx_insn *returnjump)
5705 {
5706 rtx pat = PATTERN (returnjump);
5707 if (GET_CODE (pat) == PARALLEL)
5708 pat = XVECEXP (pat, 0, 0);
5709 if (ANY_RETURN_P (pat))
5710 JUMP_LABEL (returnjump) = pat;
5711 else
5712 JUMP_LABEL (returnjump) = ret_rtx;
5713 }
5714
5715 /* Return a sequence to be used as the split prologue for the current
5716 function, or NULL. */
5717
5718 static rtx_insn *
5719 make_split_prologue_seq (void)
5720 {
5721 if (!flag_split_stack
5722 || lookup_attribute ("no_split_stack", DECL_ATTRIBUTES (cfun->decl)))
5723 return NULL;
5724
5725 start_sequence ();
5726 emit_insn (targetm.gen_split_stack_prologue ());
5727 rtx_insn *seq = get_insns ();
5728 end_sequence ();
5729
5730 record_insns (seq, NULL, &prologue_insn_hash);
5731 set_insn_locations (seq, prologue_location);
5732
5733 return seq;
5734 }
5735
5736 /* Return a sequence to be used as the prologue for the current function,
5737 or NULL. */
5738
5739 static rtx_insn *
5740 make_prologue_seq (void)
5741 {
5742 if (!targetm.have_prologue ())
5743 return NULL;
5744
5745 start_sequence ();
5746 rtx_insn *seq = targetm.gen_prologue ();
5747 emit_insn (seq);
5748
5749 /* Insert an explicit USE for the frame pointer
5750 if the profiling is on and the frame pointer is required. */
5751 if (crtl->profile && frame_pointer_needed)
5752 emit_use (hard_frame_pointer_rtx);
5753
5754 /* Retain a map of the prologue insns. */
5755 record_insns (seq, NULL, &prologue_insn_hash);
5756 emit_note (NOTE_INSN_PROLOGUE_END);
5757
5758 /* Ensure that instructions are not moved into the prologue when
5759 profiling is on. The call to the profiling routine can be
5760 emitted within the live range of a call-clobbered register. */
5761 if (!targetm.profile_before_prologue () && crtl->profile)
5762 emit_insn (gen_blockage ());
5763
5764 seq = get_insns ();
5765 end_sequence ();
5766 set_insn_locations (seq, prologue_location);
5767
5768 return seq;
5769 }
5770
5771 /* Return a sequence to be used as the epilogue for the current function,
5772 or NULL. */
5773
5774 static rtx_insn *
5775 make_epilogue_seq (void)
5776 {
5777 if (!targetm.have_epilogue ())
5778 return NULL;
5779
5780 start_sequence ();
5781 emit_note (NOTE_INSN_EPILOGUE_BEG);
5782 rtx_insn *seq = targetm.gen_epilogue ();
5783 if (seq)
5784 emit_jump_insn (seq);
5785
5786 /* Retain a map of the epilogue insns. */
5787 record_insns (seq, NULL, &epilogue_insn_hash);
5788 set_insn_locations (seq, epilogue_location);
5789
5790 seq = get_insns ();
5791 rtx_insn *returnjump = get_last_insn ();
5792 end_sequence ();
5793
5794 if (JUMP_P (returnjump))
5795 set_return_jump_label (returnjump);
5796
5797 return seq;
5798 }
5799
5800
5801 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
5802 this into place with notes indicating where the prologue ends and where
5803 the epilogue begins. Update the basic block information when possible.
5804
5805 Notes on epilogue placement:
5806 There are several kinds of edges to the exit block:
5807 * a single fallthru edge from LAST_BB
5808 * possibly, edges from blocks containing sibcalls
5809 * possibly, fake edges from infinite loops
5810
5811 The epilogue is always emitted on the fallthru edge from the last basic
5812 block in the function, LAST_BB, into the exit block.
5813
5814 If LAST_BB is empty except for a label, it is the target of every
5815 other basic block in the function that ends in a return. If a
5816 target has a return or simple_return pattern (possibly with
5817 conditional variants), these basic blocks can be changed so that a
5818 return insn is emitted into them, and their target is adjusted to
5819 the real exit block.
5820
5821 Notes on shrink wrapping: We implement a fairly conservative
5822 version of shrink-wrapping rather than the textbook one. We only
5823 generate a single prologue and a single epilogue. This is
5824 sufficient to catch a number of interesting cases involving early
5825 exits.
5826
5827 First, we identify the blocks that require the prologue to occur before
5828 them. These are the ones that modify a call-saved register, or reference
5829 any of the stack or frame pointer registers. To simplify things, we then
5830 mark everything reachable from these blocks as also requiring a prologue.
5831 This takes care of loops automatically, and avoids the need to examine
5832 whether MEMs reference the frame, since it is sufficient to check for
5833 occurrences of the stack or frame pointer.
5834
5835 We then compute the set of blocks for which the need for a prologue
5836 is anticipatable (borrowing terminology from the shrink-wrapping
5837 description in Muchnick's book). These are the blocks which either
5838 require a prologue themselves, or those that have only successors
5839 where the prologue is anticipatable. The prologue needs to be
5840 inserted on all edges from BB1->BB2 where BB2 is in ANTIC and BB1
5841 is not. For the moment, we ensure that only one such edge exists.
5842
5843 The epilogue is placed as described above, but we make a
5844 distinction between inserting return and simple_return patterns
5845 when modifying other blocks that end in a return. Blocks that end
5846 in a sibcall omit the sibcall_epilogue if the block is not in
5847 ANTIC. */
5848
5849 void
5850 thread_prologue_and_epilogue_insns (void)
5851 {
5852 df_analyze ();
5853
5854 /* Can't deal with multiple successors of the entry block at the
5855 moment. Function should always have at least one entry
5856 point. */
5857 gcc_assert (single_succ_p (ENTRY_BLOCK_PTR_FOR_FN (cfun)));
5858
5859 edge entry_edge = single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun));
5860 edge orig_entry_edge = entry_edge;
5861
5862 rtx_insn *split_prologue_seq = make_split_prologue_seq ();
5863 rtx_insn *prologue_seq = make_prologue_seq ();
5864 rtx_insn *epilogue_seq = make_epilogue_seq ();
5865
5866 /* Try to perform a kind of shrink-wrapping, making sure the
5867 prologue/epilogue is emitted only around those parts of the
5868 function that require it. */
5869 try_shrink_wrapping (&entry_edge, prologue_seq);
5870
5871 /* If the target can handle splitting the prologue/epilogue into separate
5872 components, try to shrink-wrap these components separately. */
5873 try_shrink_wrapping_separate (entry_edge->dest);
5874
5875 /* If that did anything for any component we now need the generate the
5876 "main" prologue again. Because some targets require some of these
5877 to be called in a specific order (i386 requires the split prologue
5878 to be first, for example), we create all three sequences again here.
5879 If this does not work for some target, that target should not enable
5880 separate shrink-wrapping. */
5881 if (crtl->shrink_wrapped_separate)
5882 {
5883 split_prologue_seq = make_split_prologue_seq ();
5884 prologue_seq = make_prologue_seq ();
5885 epilogue_seq = make_epilogue_seq ();
5886 }
5887
5888 rtl_profile_for_bb (EXIT_BLOCK_PTR_FOR_FN (cfun));
5889
5890 /* A small fib -- epilogue is not yet completed, but we wish to re-use
5891 this marker for the splits of EH_RETURN patterns, and nothing else
5892 uses the flag in the meantime. */
5893 epilogue_completed = 1;
5894
5895 /* Find non-fallthru edges that end with EH_RETURN instructions. On
5896 some targets, these get split to a special version of the epilogue
5897 code. In order to be able to properly annotate these with unwind
5898 info, try to split them now. If we get a valid split, drop an
5899 EPILOGUE_BEG note and mark the insns as epilogue insns. */
5900 edge e;
5901 edge_iterator ei;
5902 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
5903 {
5904 rtx_insn *prev, *last, *trial;
5905
5906 if (e->flags & EDGE_FALLTHRU)
5907 continue;
5908 last = BB_END (e->src);
5909 if (!eh_returnjump_p (last))
5910 continue;
5911
5912 prev = PREV_INSN (last);
5913 trial = try_split (PATTERN (last), last, 1);
5914 if (trial == last)
5915 continue;
5916
5917 record_insns (NEXT_INSN (prev), NEXT_INSN (trial), &epilogue_insn_hash);
5918 emit_note_after (NOTE_INSN_EPILOGUE_BEG, prev);
5919 }
5920
5921 edge exit_fallthru_edge = find_fallthru_edge (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds);
5922
5923 if (exit_fallthru_edge)
5924 {
5925 if (epilogue_seq)
5926 {
5927 insert_insn_on_edge (epilogue_seq, exit_fallthru_edge);
5928 commit_edge_insertions ();
5929
5930 /* The epilogue insns we inserted may cause the exit edge to no longer
5931 be fallthru. */
5932 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
5933 {
5934 if (((e->flags & EDGE_FALLTHRU) != 0)
5935 && returnjump_p (BB_END (e->src)))
5936 e->flags &= ~EDGE_FALLTHRU;
5937 }
5938 }
5939 else if (next_active_insn (BB_END (exit_fallthru_edge->src)))
5940 {
5941 /* We have a fall-through edge to the exit block, the source is not
5942 at the end of the function, and there will be an assembler epilogue
5943 at the end of the function.
5944 We can't use force_nonfallthru here, because that would try to
5945 use return. Inserting a jump 'by hand' is extremely messy, so
5946 we take advantage of cfg_layout_finalize using
5947 fixup_fallthru_exit_predecessor. */
5948 cfg_layout_initialize (0);
5949 basic_block cur_bb;
5950 FOR_EACH_BB_FN (cur_bb, cfun)
5951 if (cur_bb->index >= NUM_FIXED_BLOCKS
5952 && cur_bb->next_bb->index >= NUM_FIXED_BLOCKS)
5953 cur_bb->aux = cur_bb->next_bb;
5954 cfg_layout_finalize ();
5955 }
5956 }
5957
5958 /* Insert the prologue. */
5959
5960 rtl_profile_for_bb (ENTRY_BLOCK_PTR_FOR_FN (cfun));
5961
5962 if (split_prologue_seq || prologue_seq)
5963 {
5964 rtx_insn *split_prologue_insn = split_prologue_seq;
5965 if (split_prologue_seq)
5966 {
5967 while (split_prologue_insn && !NONDEBUG_INSN_P (split_prologue_insn))
5968 split_prologue_insn = NEXT_INSN (split_prologue_insn);
5969 insert_insn_on_edge (split_prologue_seq, orig_entry_edge);
5970 }
5971
5972 rtx_insn *prologue_insn = prologue_seq;
5973 if (prologue_seq)
5974 {
5975 while (prologue_insn && !NONDEBUG_INSN_P (prologue_insn))
5976 prologue_insn = NEXT_INSN (prologue_insn);
5977 insert_insn_on_edge (prologue_seq, entry_edge);
5978 }
5979
5980 commit_edge_insertions ();
5981
5982 /* Look for basic blocks within the prologue insns. */
5983 if (split_prologue_insn
5984 && BLOCK_FOR_INSN (split_prologue_insn) == NULL)
5985 split_prologue_insn = NULL;
5986 if (prologue_insn
5987 && BLOCK_FOR_INSN (prologue_insn) == NULL)
5988 prologue_insn = NULL;
5989 if (split_prologue_insn || prologue_insn)
5990 {
5991 auto_sbitmap blocks (last_basic_block_for_fn (cfun));
5992 bitmap_clear (blocks);
5993 if (split_prologue_insn)
5994 bitmap_set_bit (blocks,
5995 BLOCK_FOR_INSN (split_prologue_insn)->index);
5996 if (prologue_insn)
5997 bitmap_set_bit (blocks, BLOCK_FOR_INSN (prologue_insn)->index);
5998 find_many_sub_basic_blocks (blocks);
5999 }
6000 }
6001
6002 default_rtl_profile ();
6003
6004 /* Emit sibling epilogues before any sibling call sites. */
6005 for (ei = ei_start (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds);
6006 (e = ei_safe_edge (ei));
6007 ei_next (&ei))
6008 {
6009 /* Skip those already handled, the ones that run without prologue. */
6010 if (e->flags & EDGE_IGNORE)
6011 {
6012 e->flags &= ~EDGE_IGNORE;
6013 continue;
6014 }
6015
6016 rtx_insn *insn = BB_END (e->src);
6017
6018 if (!(CALL_P (insn) && SIBLING_CALL_P (insn)))
6019 continue;
6020
6021 if (rtx_insn *ep_seq = targetm.gen_sibcall_epilogue ())
6022 {
6023 start_sequence ();
6024 emit_note (NOTE_INSN_EPILOGUE_BEG);
6025 emit_insn (ep_seq);
6026 rtx_insn *seq = get_insns ();
6027 end_sequence ();
6028
6029 /* Retain a map of the epilogue insns. Used in life analysis to
6030 avoid getting rid of sibcall epilogue insns. Do this before we
6031 actually emit the sequence. */
6032 record_insns (seq, NULL, &epilogue_insn_hash);
6033 set_insn_locations (seq, epilogue_location);
6034
6035 emit_insn_before (seq, insn);
6036 }
6037 }
6038
6039 if (epilogue_seq)
6040 {
6041 rtx_insn *insn, *next;
6042
6043 /* Similarly, move any line notes that appear after the epilogue.
6044 There is no need, however, to be quite so anal about the existence
6045 of such a note. Also possibly move
6046 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
6047 info generation. */
6048 for (insn = epilogue_seq; insn; insn = next)
6049 {
6050 next = NEXT_INSN (insn);
6051 if (NOTE_P (insn)
6052 && (NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG))
6053 reorder_insns (insn, insn, PREV_INSN (epilogue_seq));
6054 }
6055 }
6056
6057 /* Threading the prologue and epilogue changes the artificial refs
6058 in the entry and exit blocks. */
6059 epilogue_completed = 1;
6060 df_update_entry_exit_and_calls ();
6061 }
6062
6063 /* Reposition the prologue-end and epilogue-begin notes after
6064 instruction scheduling. */
6065
6066 void
6067 reposition_prologue_and_epilogue_notes (void)
6068 {
6069 if (!targetm.have_prologue ()
6070 && !targetm.have_epilogue ()
6071 && !targetm.have_sibcall_epilogue ())
6072 return;
6073
6074 /* Since the hash table is created on demand, the fact that it is
6075 non-null is a signal that it is non-empty. */
6076 if (prologue_insn_hash != NULL)
6077 {
6078 size_t len = prologue_insn_hash->elements ();
6079 rtx_insn *insn, *last = NULL, *note = NULL;
6080
6081 /* Scan from the beginning until we reach the last prologue insn. */
6082 /* ??? While we do have the CFG intact, there are two problems:
6083 (1) The prologue can contain loops (typically probing the stack),
6084 which means that the end of the prologue isn't in the first bb.
6085 (2) Sometimes the PROLOGUE_END note gets pushed into the next bb. */
6086 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
6087 {
6088 if (NOTE_P (insn))
6089 {
6090 if (NOTE_KIND (insn) == NOTE_INSN_PROLOGUE_END)
6091 note = insn;
6092 }
6093 else if (contains (insn, prologue_insn_hash))
6094 {
6095 last = insn;
6096 if (--len == 0)
6097 break;
6098 }
6099 }
6100
6101 if (last)
6102 {
6103 if (note == NULL)
6104 {
6105 /* Scan forward looking for the PROLOGUE_END note. It should
6106 be right at the beginning of the block, possibly with other
6107 insn notes that got moved there. */
6108 for (note = NEXT_INSN (last); ; note = NEXT_INSN (note))
6109 {
6110 if (NOTE_P (note)
6111 && NOTE_KIND (note) == NOTE_INSN_PROLOGUE_END)
6112 break;
6113 }
6114 }
6115
6116 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
6117 if (LABEL_P (last))
6118 last = NEXT_INSN (last);
6119 reorder_insns (note, note, last);
6120 }
6121 }
6122
6123 if (epilogue_insn_hash != NULL)
6124 {
6125 edge_iterator ei;
6126 edge e;
6127
6128 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
6129 {
6130 rtx_insn *insn, *first = NULL, *note = NULL;
6131 basic_block bb = e->src;
6132
6133 /* Scan from the beginning until we reach the first epilogue insn. */
6134 FOR_BB_INSNS (bb, insn)
6135 {
6136 if (NOTE_P (insn))
6137 {
6138 if (NOTE_KIND (insn) == NOTE_INSN_EPILOGUE_BEG)
6139 {
6140 note = insn;
6141 if (first != NULL)
6142 break;
6143 }
6144 }
6145 else if (first == NULL && contains (insn, epilogue_insn_hash))
6146 {
6147 first = insn;
6148 if (note != NULL)
6149 break;
6150 }
6151 }
6152
6153 if (note)
6154 {
6155 /* If the function has a single basic block, and no real
6156 epilogue insns (e.g. sibcall with no cleanup), the
6157 epilogue note can get scheduled before the prologue
6158 note. If we have frame related prologue insns, having
6159 them scanned during the epilogue will result in a crash.
6160 In this case re-order the epilogue note to just before
6161 the last insn in the block. */
6162 if (first == NULL)
6163 first = BB_END (bb);
6164
6165 if (PREV_INSN (first) != note)
6166 reorder_insns (note, note, PREV_INSN (first));
6167 }
6168 }
6169 }
6170 }
6171
6172 /* Returns the name of function declared by FNDECL. */
6173 const char *
6174 fndecl_name (tree fndecl)
6175 {
6176 if (fndecl == NULL)
6177 return "(nofn)";
6178 return lang_hooks.decl_printable_name (fndecl, 1);
6179 }
6180
6181 /* Returns the name of function FN. */
6182 const char *
6183 function_name (struct function *fn)
6184 {
6185 tree fndecl = (fn == NULL) ? NULL : fn->decl;
6186 return fndecl_name (fndecl);
6187 }
6188
6189 /* Returns the name of the current function. */
6190 const char *
6191 current_function_name (void)
6192 {
6193 return function_name (cfun);
6194 }
6195 \f
6196
6197 static unsigned int
6198 rest_of_handle_check_leaf_regs (void)
6199 {
6200 #ifdef LEAF_REGISTERS
6201 crtl->uses_only_leaf_regs
6202 = optimize > 0 && only_leaf_regs_used () && leaf_function_p ();
6203 #endif
6204 return 0;
6205 }
6206
6207 /* Insert a TYPE into the used types hash table of CFUN. */
6208
6209 static void
6210 used_types_insert_helper (tree type, struct function *func)
6211 {
6212 if (type != NULL && func != NULL)
6213 {
6214 if (func->used_types_hash == NULL)
6215 func->used_types_hash = hash_set<tree>::create_ggc (37);
6216
6217 func->used_types_hash->add (type);
6218 }
6219 }
6220
6221 /* Given a type, insert it into the used hash table in cfun. */
6222 void
6223 used_types_insert (tree t)
6224 {
6225 while (POINTER_TYPE_P (t) || TREE_CODE (t) == ARRAY_TYPE)
6226 if (TYPE_NAME (t))
6227 break;
6228 else
6229 t = TREE_TYPE (t);
6230 if (TREE_CODE (t) == ERROR_MARK)
6231 return;
6232 if (TYPE_NAME (t) == NULL_TREE
6233 || TYPE_NAME (t) == TYPE_NAME (TYPE_MAIN_VARIANT (t)))
6234 t = TYPE_MAIN_VARIANT (t);
6235 if (debug_info_level > DINFO_LEVEL_NONE)
6236 {
6237 if (cfun)
6238 used_types_insert_helper (t, cfun);
6239 else
6240 {
6241 /* So this might be a type referenced by a global variable.
6242 Record that type so that we can later decide to emit its
6243 debug information. */
6244 vec_safe_push (types_used_by_cur_var_decl, t);
6245 }
6246 }
6247 }
6248
6249 /* Helper to Hash a struct types_used_by_vars_entry. */
6250
6251 static hashval_t
6252 hash_types_used_by_vars_entry (const struct types_used_by_vars_entry *entry)
6253 {
6254 gcc_assert (entry && entry->var_decl && entry->type);
6255
6256 return iterative_hash_object (entry->type,
6257 iterative_hash_object (entry->var_decl, 0));
6258 }
6259
6260 /* Hash function of the types_used_by_vars_entry hash table. */
6261
6262 hashval_t
6263 used_type_hasher::hash (types_used_by_vars_entry *entry)
6264 {
6265 return hash_types_used_by_vars_entry (entry);
6266 }
6267
6268 /*Equality function of the types_used_by_vars_entry hash table. */
6269
6270 bool
6271 used_type_hasher::equal (types_used_by_vars_entry *e1,
6272 types_used_by_vars_entry *e2)
6273 {
6274 return (e1->var_decl == e2->var_decl && e1->type == e2->type);
6275 }
6276
6277 /* Inserts an entry into the types_used_by_vars_hash hash table. */
6278
6279 void
6280 types_used_by_var_decl_insert (tree type, tree var_decl)
6281 {
6282 if (type != NULL && var_decl != NULL)
6283 {
6284 types_used_by_vars_entry **slot;
6285 struct types_used_by_vars_entry e;
6286 e.var_decl = var_decl;
6287 e.type = type;
6288 if (types_used_by_vars_hash == NULL)
6289 types_used_by_vars_hash
6290 = hash_table<used_type_hasher>::create_ggc (37);
6291
6292 slot = types_used_by_vars_hash->find_slot (&e, INSERT);
6293 if (*slot == NULL)
6294 {
6295 struct types_used_by_vars_entry *entry;
6296 entry = ggc_alloc<types_used_by_vars_entry> ();
6297 entry->type = type;
6298 entry->var_decl = var_decl;
6299 *slot = entry;
6300 }
6301 }
6302 }
6303
6304 namespace {
6305
6306 const pass_data pass_data_leaf_regs =
6307 {
6308 RTL_PASS, /* type */
6309 "*leaf_regs", /* name */
6310 OPTGROUP_NONE, /* optinfo_flags */
6311 TV_NONE, /* tv_id */
6312 0, /* properties_required */
6313 0, /* properties_provided */
6314 0, /* properties_destroyed */
6315 0, /* todo_flags_start */
6316 0, /* todo_flags_finish */
6317 };
6318
6319 class pass_leaf_regs : public rtl_opt_pass
6320 {
6321 public:
6322 pass_leaf_regs (gcc::context *ctxt)
6323 : rtl_opt_pass (pass_data_leaf_regs, ctxt)
6324 {}
6325
6326 /* opt_pass methods: */
6327 virtual unsigned int execute (function *)
6328 {
6329 return rest_of_handle_check_leaf_regs ();
6330 }
6331
6332 }; // class pass_leaf_regs
6333
6334 } // anon namespace
6335
6336 rtl_opt_pass *
6337 make_pass_leaf_regs (gcc::context *ctxt)
6338 {
6339 return new pass_leaf_regs (ctxt);
6340 }
6341
6342 static unsigned int
6343 rest_of_handle_thread_prologue_and_epilogue (void)
6344 {
6345 /* prepare_shrink_wrap is sensitive to the block structure of the control
6346 flow graph, so clean it up first. */
6347 if (optimize)
6348 cleanup_cfg (0);
6349
6350 /* On some machines, the prologue and epilogue code, or parts thereof,
6351 can be represented as RTL. Doing so lets us schedule insns between
6352 it and the rest of the code and also allows delayed branch
6353 scheduling to operate in the epilogue. */
6354 thread_prologue_and_epilogue_insns ();
6355
6356 /* Some non-cold blocks may now be only reachable from cold blocks.
6357 Fix that up. */
6358 fixup_partitions ();
6359
6360 /* Shrink-wrapping can result in unreachable edges in the epilogue,
6361 see PR57320. */
6362 cleanup_cfg (optimize ? CLEANUP_EXPENSIVE : 0);
6363
6364 /* The stack usage info is finalized during prologue expansion. */
6365 if (flag_stack_usage_info)
6366 output_stack_usage ();
6367
6368 return 0;
6369 }
6370
6371 namespace {
6372
6373 const pass_data pass_data_thread_prologue_and_epilogue =
6374 {
6375 RTL_PASS, /* type */
6376 "pro_and_epilogue", /* name */
6377 OPTGROUP_NONE, /* optinfo_flags */
6378 TV_THREAD_PROLOGUE_AND_EPILOGUE, /* tv_id */
6379 0, /* properties_required */
6380 0, /* properties_provided */
6381 0, /* properties_destroyed */
6382 0, /* todo_flags_start */
6383 ( TODO_df_verify | TODO_df_finish ), /* todo_flags_finish */
6384 };
6385
6386 class pass_thread_prologue_and_epilogue : public rtl_opt_pass
6387 {
6388 public:
6389 pass_thread_prologue_and_epilogue (gcc::context *ctxt)
6390 : rtl_opt_pass (pass_data_thread_prologue_and_epilogue, ctxt)
6391 {}
6392
6393 /* opt_pass methods: */
6394 virtual unsigned int execute (function *)
6395 {
6396 return rest_of_handle_thread_prologue_and_epilogue ();
6397 }
6398
6399 }; // class pass_thread_prologue_and_epilogue
6400
6401 } // anon namespace
6402
6403 rtl_opt_pass *
6404 make_pass_thread_prologue_and_epilogue (gcc::context *ctxt)
6405 {
6406 return new pass_thread_prologue_and_epilogue (ctxt);
6407 }
6408 \f
6409
6410 /* If CONSTRAINT is a matching constraint, then return its number.
6411 Otherwise, return -1. */
6412
6413 static int
6414 matching_constraint_num (const char *constraint)
6415 {
6416 if (*constraint == '%')
6417 constraint++;
6418
6419 if (IN_RANGE (*constraint, '0', '9'))
6420 return strtoul (constraint, NULL, 10);
6421
6422 return -1;
6423 }
6424
6425 /* This mini-pass fixes fall-out from SSA in asm statements that have
6426 in-out constraints. Say you start with
6427
6428 orig = inout;
6429 asm ("": "+mr" (inout));
6430 use (orig);
6431
6432 which is transformed very early to use explicit output and match operands:
6433
6434 orig = inout;
6435 asm ("": "=mr" (inout) : "0" (inout));
6436 use (orig);
6437
6438 Or, after SSA and copyprop,
6439
6440 asm ("": "=mr" (inout_2) : "0" (inout_1));
6441 use (inout_1);
6442
6443 Clearly inout_2 and inout_1 can't be coalesced easily anymore, as
6444 they represent two separate values, so they will get different pseudo
6445 registers during expansion. Then, since the two operands need to match
6446 per the constraints, but use different pseudo registers, reload can
6447 only register a reload for these operands. But reloads can only be
6448 satisfied by hardregs, not by memory, so we need a register for this
6449 reload, just because we are presented with non-matching operands.
6450 So, even though we allow memory for this operand, no memory can be
6451 used for it, just because the two operands don't match. This can
6452 cause reload failures on register-starved targets.
6453
6454 So it's a symptom of reload not being able to use memory for reloads
6455 or, alternatively it's also a symptom of both operands not coming into
6456 reload as matching (in which case the pseudo could go to memory just
6457 fine, as the alternative allows it, and no reload would be necessary).
6458 We fix the latter problem here, by transforming
6459
6460 asm ("": "=mr" (inout_2) : "0" (inout_1));
6461
6462 back to
6463
6464 inout_2 = inout_1;
6465 asm ("": "=mr" (inout_2) : "0" (inout_2)); */
6466
6467 static void
6468 match_asm_constraints_1 (rtx_insn *insn, rtx *p_sets, int noutputs)
6469 {
6470 int i;
6471 bool changed = false;
6472 rtx op = SET_SRC (p_sets[0]);
6473 int ninputs = ASM_OPERANDS_INPUT_LENGTH (op);
6474 rtvec inputs = ASM_OPERANDS_INPUT_VEC (op);
6475 bool *output_matched = XALLOCAVEC (bool, noutputs);
6476
6477 memset (output_matched, 0, noutputs * sizeof (bool));
6478 for (i = 0; i < ninputs; i++)
6479 {
6480 rtx input, output;
6481 rtx_insn *insns;
6482 const char *constraint = ASM_OPERANDS_INPUT_CONSTRAINT (op, i);
6483 int match, j;
6484
6485 match = matching_constraint_num (constraint);
6486 if (match < 0)
6487 continue;
6488
6489 gcc_assert (match < noutputs);
6490 output = SET_DEST (p_sets[match]);
6491 input = RTVEC_ELT (inputs, i);
6492 /* Only do the transformation for pseudos. */
6493 if (! REG_P (output)
6494 || rtx_equal_p (output, input)
6495 || !(REG_P (input) || SUBREG_P (input)
6496 || MEM_P (input) || CONSTANT_P (input))
6497 || !general_operand (input, GET_MODE (output)))
6498 continue;
6499
6500 /* We can't do anything if the output is also used as input,
6501 as we're going to overwrite it. */
6502 for (j = 0; j < ninputs; j++)
6503 if (reg_overlap_mentioned_p (output, RTVEC_ELT (inputs, j)))
6504 break;
6505 if (j != ninputs)
6506 continue;
6507
6508 /* Avoid changing the same input several times. For
6509 asm ("" : "=mr" (out1), "=mr" (out2) : "0" (in), "1" (in));
6510 only change it once (to out1), rather than changing it
6511 first to out1 and afterwards to out2. */
6512 if (i > 0)
6513 {
6514 for (j = 0; j < noutputs; j++)
6515 if (output_matched[j] && input == SET_DEST (p_sets[j]))
6516 break;
6517 if (j != noutputs)
6518 continue;
6519 }
6520 output_matched[match] = true;
6521
6522 start_sequence ();
6523 emit_move_insn (output, copy_rtx (input));
6524 insns = get_insns ();
6525 end_sequence ();
6526 emit_insn_before (insns, insn);
6527
6528 constraint = ASM_OPERANDS_OUTPUT_CONSTRAINT(SET_SRC(p_sets[match]));
6529 bool early_clobber_p = strchr (constraint, '&') != NULL;
6530
6531 /* Now replace all mentions of the input with output. We can't
6532 just replace the occurrence in inputs[i], as the register might
6533 also be used in some other input (or even in an address of an
6534 output), which would mean possibly increasing the number of
6535 inputs by one (namely 'output' in addition), which might pose
6536 a too complicated problem for reload to solve. E.g. this situation:
6537
6538 asm ("" : "=r" (output), "=m" (input) : "0" (input))
6539
6540 Here 'input' is used in two occurrences as input (once for the
6541 input operand, once for the address in the second output operand).
6542 If we would replace only the occurrence of the input operand (to
6543 make the matching) we would be left with this:
6544
6545 output = input
6546 asm ("" : "=r" (output), "=m" (input) : "0" (output))
6547
6548 Now we suddenly have two different input values (containing the same
6549 value, but different pseudos) where we formerly had only one.
6550 With more complicated asms this might lead to reload failures
6551 which wouldn't have happen without this pass. So, iterate over
6552 all operands and replace all occurrences of the register used.
6553
6554 However, if one or more of the 'input' uses have a non-matching
6555 constraint and the matched output operand is an early clobber
6556 operand, then do not replace the input operand, since by definition
6557 it conflicts with the output operand and cannot share the same
6558 register. See PR89313 for details. */
6559
6560 for (j = 0; j < noutputs; j++)
6561 if (!rtx_equal_p (SET_DEST (p_sets[j]), input)
6562 && reg_overlap_mentioned_p (input, SET_DEST (p_sets[j])))
6563 SET_DEST (p_sets[j]) = replace_rtx (SET_DEST (p_sets[j]),
6564 input, output);
6565 for (j = 0; j < ninputs; j++)
6566 if (reg_overlap_mentioned_p (input, RTVEC_ELT (inputs, j)))
6567 {
6568 if (!early_clobber_p
6569 || match == matching_constraint_num
6570 (ASM_OPERANDS_INPUT_CONSTRAINT (op, j)))
6571 RTVEC_ELT (inputs, j) = replace_rtx (RTVEC_ELT (inputs, j),
6572 input, output);
6573 }
6574
6575 changed = true;
6576 }
6577
6578 if (changed)
6579 df_insn_rescan (insn);
6580 }
6581
6582 /* Add the decl D to the local_decls list of FUN. */
6583
6584 void
6585 add_local_decl (struct function *fun, tree d)
6586 {
6587 gcc_assert (VAR_P (d));
6588 vec_safe_push (fun->local_decls, d);
6589 }
6590
6591 namespace {
6592
6593 const pass_data pass_data_match_asm_constraints =
6594 {
6595 RTL_PASS, /* type */
6596 "asmcons", /* name */
6597 OPTGROUP_NONE, /* optinfo_flags */
6598 TV_NONE, /* tv_id */
6599 0, /* properties_required */
6600 0, /* properties_provided */
6601 0, /* properties_destroyed */
6602 0, /* todo_flags_start */
6603 0, /* todo_flags_finish */
6604 };
6605
6606 class pass_match_asm_constraints : public rtl_opt_pass
6607 {
6608 public:
6609 pass_match_asm_constraints (gcc::context *ctxt)
6610 : rtl_opt_pass (pass_data_match_asm_constraints, ctxt)
6611 {}
6612
6613 /* opt_pass methods: */
6614 virtual unsigned int execute (function *);
6615
6616 }; // class pass_match_asm_constraints
6617
6618 unsigned
6619 pass_match_asm_constraints::execute (function *fun)
6620 {
6621 basic_block bb;
6622 rtx_insn *insn;
6623 rtx pat, *p_sets;
6624 int noutputs;
6625
6626 if (!crtl->has_asm_statement)
6627 return 0;
6628
6629 df_set_flags (DF_DEFER_INSN_RESCAN);
6630 FOR_EACH_BB_FN (bb, fun)
6631 {
6632 FOR_BB_INSNS (bb, insn)
6633 {
6634 if (!INSN_P (insn))
6635 continue;
6636
6637 pat = PATTERN (insn);
6638 if (GET_CODE (pat) == PARALLEL)
6639 p_sets = &XVECEXP (pat, 0, 0), noutputs = XVECLEN (pat, 0);
6640 else if (GET_CODE (pat) == SET)
6641 p_sets = &PATTERN (insn), noutputs = 1;
6642 else
6643 continue;
6644
6645 if (GET_CODE (*p_sets) == SET
6646 && GET_CODE (SET_SRC (*p_sets)) == ASM_OPERANDS)
6647 match_asm_constraints_1 (insn, p_sets, noutputs);
6648 }
6649 }
6650
6651 return TODO_df_finish;
6652 }
6653
6654 } // anon namespace
6655
6656 rtl_opt_pass *
6657 make_pass_match_asm_constraints (gcc::context *ctxt)
6658 {
6659 return new pass_match_asm_constraints (ctxt);
6660 }
6661
6662
6663 #include "gt-function.h"