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1 /* Expands front end tree to back end RTL for GCC.
2 Copyright (C) 1987-2019 Free Software Foundation, Inc.
3
4 This file is part of GCC.
5
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
10
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
19
20 /* This file handles the generation of rtl code from tree structure
21 at the level of the function as a whole.
22 It creates the rtl expressions for parameters and auto variables
23 and has full responsibility for allocating stack slots.
24
25 `expand_function_start' is called at the beginning of a function,
26 before the function body is parsed, and `expand_function_end' is
27 called after parsing the body.
28
29 Call `assign_stack_local' to allocate a stack slot for a local variable.
30 This is usually done during the RTL generation for the function body,
31 but it can also be done in the reload pass when a pseudo-register does
32 not get a hard register. */
33
34 #include "config.h"
35 #include "system.h"
36 #include "coretypes.h"
37 #include "backend.h"
38 #include "target.h"
39 #include "rtl.h"
40 #include "tree.h"
41 #include "gimple-expr.h"
42 #include "cfghooks.h"
43 #include "df.h"
44 #include "memmodel.h"
45 #include "tm_p.h"
46 #include "stringpool.h"
47 #include "expmed.h"
48 #include "optabs.h"
49 #include "regs.h"
50 #include "emit-rtl.h"
51 #include "recog.h"
52 #include "rtl-error.h"
53 #include "alias.h"
54 #include "fold-const.h"
55 #include "stor-layout.h"
56 #include "varasm.h"
57 #include "except.h"
58 #include "dojump.h"
59 #include "explow.h"
60 #include "calls.h"
61 #include "expr.h"
62 #include "optabs-tree.h"
63 #include "output.h"
64 #include "langhooks.h"
65 #include "common/common-target.h"
66 #include "gimplify.h"
67 #include "tree-pass.h"
68 #include "cfgrtl.h"
69 #include "cfganal.h"
70 #include "cfgbuild.h"
71 #include "cfgcleanup.h"
72 #include "cfgexpand.h"
73 #include "shrink-wrap.h"
74 #include "toplev.h"
75 #include "rtl-iter.h"
76 #include "tree-dfa.h"
77 #include "tree-ssa.h"
78 #include "stringpool.h"
79 #include "attribs.h"
80 #include "gimple.h"
81 #include "options.h"
82
83 /* So we can assign to cfun in this file. */
84 #undef cfun
85
86 #ifndef STACK_ALIGNMENT_NEEDED
87 #define STACK_ALIGNMENT_NEEDED 1
88 #endif
89
90 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
91
92 /* Round a value to the lowest integer less than it that is a multiple of
93 the required alignment. Avoid using division in case the value is
94 negative. Assume the alignment is a power of two. */
95 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
96
97 /* Similar, but round to the next highest integer that meets the
98 alignment. */
99 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
100
101 /* Nonzero once virtual register instantiation has been done.
102 assign_stack_local uses frame_pointer_rtx when this is nonzero.
103 calls.c:emit_library_call_value_1 uses it to set up
104 post-instantiation libcalls. */
105 int virtuals_instantiated;
106
107 /* Assign unique numbers to labels generated for profiling, debugging, etc. */
108 static GTY(()) int funcdef_no;
109
110 /* These variables hold pointers to functions to create and destroy
111 target specific, per-function data structures. */
112 struct machine_function * (*init_machine_status) (void);
113
114 /* The currently compiled function. */
115 struct function *cfun = 0;
116
117 /* These hashes record the prologue and epilogue insns. */
118
119 struct insn_cache_hasher : ggc_cache_ptr_hash<rtx_def>
120 {
121 static hashval_t hash (rtx x) { return htab_hash_pointer (x); }
122 static bool equal (rtx a, rtx b) { return a == b; }
123 };
124
125 static GTY((cache))
126 hash_table<insn_cache_hasher> *prologue_insn_hash;
127 static GTY((cache))
128 hash_table<insn_cache_hasher> *epilogue_insn_hash;
129 \f
130
131 hash_table<used_type_hasher> *types_used_by_vars_hash = NULL;
132 vec<tree, va_gc> *types_used_by_cur_var_decl;
133
134 /* Forward declarations. */
135
136 static class temp_slot *find_temp_slot_from_address (rtx);
137 static void pad_to_arg_alignment (struct args_size *, int, struct args_size *);
138 static void pad_below (struct args_size *, machine_mode, tree);
139 static void reorder_blocks_1 (rtx_insn *, tree, vec<tree> *);
140 static int all_blocks (tree, tree *);
141 static tree *get_block_vector (tree, int *);
142 extern tree debug_find_var_in_block_tree (tree, tree);
143 /* We always define `record_insns' even if it's not used so that we
144 can always export `prologue_epilogue_contains'. */
145 static void record_insns (rtx_insn *, rtx, hash_table<insn_cache_hasher> **)
146 ATTRIBUTE_UNUSED;
147 static bool contains (const rtx_insn *, hash_table<insn_cache_hasher> *);
148 static void prepare_function_start (void);
149 static void do_clobber_return_reg (rtx, void *);
150 static void do_use_return_reg (rtx, void *);
151
152 \f
153 /* Stack of nested functions. */
154 /* Keep track of the cfun stack. */
155
156 static vec<function *> function_context_stack;
157
158 /* Save the current context for compilation of a nested function.
159 This is called from language-specific code. */
160
161 void
162 push_function_context (void)
163 {
164 if (cfun == 0)
165 allocate_struct_function (NULL, false);
166
167 function_context_stack.safe_push (cfun);
168 set_cfun (NULL);
169 }
170
171 /* Restore the last saved context, at the end of a nested function.
172 This function is called from language-specific code. */
173
174 void
175 pop_function_context (void)
176 {
177 struct function *p = function_context_stack.pop ();
178 set_cfun (p);
179 current_function_decl = p->decl;
180
181 /* Reset variables that have known state during rtx generation. */
182 virtuals_instantiated = 0;
183 generating_concat_p = 1;
184 }
185
186 /* Clear out all parts of the state in F that can safely be discarded
187 after the function has been parsed, but not compiled, to let
188 garbage collection reclaim the memory. */
189
190 void
191 free_after_parsing (struct function *f)
192 {
193 f->language = 0;
194 }
195
196 /* Clear out all parts of the state in F that can safely be discarded
197 after the function has been compiled, to let garbage collection
198 reclaim the memory. */
199
200 void
201 free_after_compilation (struct function *f)
202 {
203 prologue_insn_hash = NULL;
204 epilogue_insn_hash = NULL;
205
206 free (crtl->emit.regno_pointer_align);
207
208 memset (crtl, 0, sizeof (struct rtl_data));
209 f->eh = NULL;
210 f->machine = NULL;
211 f->cfg = NULL;
212 f->curr_properties &= ~PROP_cfg;
213
214 regno_reg_rtx = NULL;
215 }
216 \f
217 /* Return size needed for stack frame based on slots so far allocated.
218 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
219 the caller may have to do that. */
220
221 poly_int64
222 get_frame_size (void)
223 {
224 if (FRAME_GROWS_DOWNWARD)
225 return -frame_offset;
226 else
227 return frame_offset;
228 }
229
230 /* Issue an error message and return TRUE if frame OFFSET overflows in
231 the signed target pointer arithmetics for function FUNC. Otherwise
232 return FALSE. */
233
234 bool
235 frame_offset_overflow (poly_int64 offset, tree func)
236 {
237 poly_uint64 size = FRAME_GROWS_DOWNWARD ? -offset : offset;
238 unsigned HOST_WIDE_INT limit
239 = ((HOST_WIDE_INT_1U << (GET_MODE_BITSIZE (Pmode) - 1))
240 /* Leave room for the fixed part of the frame. */
241 - 64 * UNITS_PER_WORD);
242
243 if (!coeffs_in_range_p (size, 0U, limit))
244 {
245 unsigned HOST_WIDE_INT hwisize;
246 if (size.is_constant (&hwisize))
247 error_at (DECL_SOURCE_LOCATION (func),
248 "total size of local objects %wu exceeds maximum %wu",
249 hwisize, limit);
250 else
251 error_at (DECL_SOURCE_LOCATION (func),
252 "total size of local objects exceeds maximum %wu",
253 limit);
254 return true;
255 }
256
257 return false;
258 }
259
260 /* Return the minimum spill slot alignment for a register of mode MODE. */
261
262 unsigned int
263 spill_slot_alignment (machine_mode mode ATTRIBUTE_UNUSED)
264 {
265 return STACK_SLOT_ALIGNMENT (NULL_TREE, mode, GET_MODE_ALIGNMENT (mode));
266 }
267
268 /* Return stack slot alignment in bits for TYPE and MODE. */
269
270 static unsigned int
271 get_stack_local_alignment (tree type, machine_mode mode)
272 {
273 unsigned int alignment;
274
275 if (mode == BLKmode)
276 alignment = BIGGEST_ALIGNMENT;
277 else
278 alignment = GET_MODE_ALIGNMENT (mode);
279
280 /* Allow the frond-end to (possibly) increase the alignment of this
281 stack slot. */
282 if (! type)
283 type = lang_hooks.types.type_for_mode (mode, 0);
284
285 return STACK_SLOT_ALIGNMENT (type, mode, alignment);
286 }
287
288 /* Determine whether it is possible to fit a stack slot of size SIZE and
289 alignment ALIGNMENT into an area in the stack frame that starts at
290 frame offset START and has a length of LENGTH. If so, store the frame
291 offset to be used for the stack slot in *POFFSET and return true;
292 return false otherwise. This function will extend the frame size when
293 given a start/length pair that lies at the end of the frame. */
294
295 static bool
296 try_fit_stack_local (poly_int64 start, poly_int64 length,
297 poly_int64 size, unsigned int alignment,
298 poly_int64_pod *poffset)
299 {
300 poly_int64 this_frame_offset;
301 int frame_off, frame_alignment, frame_phase;
302
303 /* Calculate how many bytes the start of local variables is off from
304 stack alignment. */
305 frame_alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
306 frame_off = targetm.starting_frame_offset () % frame_alignment;
307 frame_phase = frame_off ? frame_alignment - frame_off : 0;
308
309 /* Round the frame offset to the specified alignment. */
310
311 if (FRAME_GROWS_DOWNWARD)
312 this_frame_offset
313 = (aligned_lower_bound (start + length - size - frame_phase, alignment)
314 + frame_phase);
315 else
316 this_frame_offset
317 = aligned_upper_bound (start - frame_phase, alignment) + frame_phase;
318
319 /* See if it fits. If this space is at the edge of the frame,
320 consider extending the frame to make it fit. Our caller relies on
321 this when allocating a new slot. */
322 if (maybe_lt (this_frame_offset, start))
323 {
324 if (known_eq (frame_offset, start))
325 frame_offset = this_frame_offset;
326 else
327 return false;
328 }
329 else if (maybe_gt (this_frame_offset + size, start + length))
330 {
331 if (known_eq (frame_offset, start + length))
332 frame_offset = this_frame_offset + size;
333 else
334 return false;
335 }
336
337 *poffset = this_frame_offset;
338 return true;
339 }
340
341 /* Create a new frame_space structure describing free space in the stack
342 frame beginning at START and ending at END, and chain it into the
343 function's frame_space_list. */
344
345 static void
346 add_frame_space (poly_int64 start, poly_int64 end)
347 {
348 class frame_space *space = ggc_alloc<frame_space> ();
349 space->next = crtl->frame_space_list;
350 crtl->frame_space_list = space;
351 space->start = start;
352 space->length = end - start;
353 }
354
355 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
356 with machine mode MODE.
357
358 ALIGN controls the amount of alignment for the address of the slot:
359 0 means according to MODE,
360 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
361 -2 means use BITS_PER_UNIT,
362 positive specifies alignment boundary in bits.
363
364 KIND has ASLK_REDUCE_ALIGN bit set if it is OK to reduce
365 alignment and ASLK_RECORD_PAD bit set if we should remember
366 extra space we allocated for alignment purposes. When we are
367 called from assign_stack_temp_for_type, it is not set so we don't
368 track the same stack slot in two independent lists.
369
370 We do not round to stack_boundary here. */
371
372 rtx
373 assign_stack_local_1 (machine_mode mode, poly_int64 size,
374 int align, int kind)
375 {
376 rtx x, addr;
377 poly_int64 bigend_correction = 0;
378 poly_int64 slot_offset = 0, old_frame_offset;
379 unsigned int alignment, alignment_in_bits;
380
381 if (align == 0)
382 {
383 alignment = get_stack_local_alignment (NULL, mode);
384 alignment /= BITS_PER_UNIT;
385 }
386 else if (align == -1)
387 {
388 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
389 size = aligned_upper_bound (size, alignment);
390 }
391 else if (align == -2)
392 alignment = 1; /* BITS_PER_UNIT / BITS_PER_UNIT */
393 else
394 alignment = align / BITS_PER_UNIT;
395
396 alignment_in_bits = alignment * BITS_PER_UNIT;
397
398 /* Ignore alignment if it exceeds MAX_SUPPORTED_STACK_ALIGNMENT. */
399 if (alignment_in_bits > MAX_SUPPORTED_STACK_ALIGNMENT)
400 {
401 alignment_in_bits = MAX_SUPPORTED_STACK_ALIGNMENT;
402 alignment = MAX_SUPPORTED_STACK_ALIGNMENT / BITS_PER_UNIT;
403 }
404
405 if (SUPPORTS_STACK_ALIGNMENT)
406 {
407 if (crtl->stack_alignment_estimated < alignment_in_bits)
408 {
409 if (!crtl->stack_realign_processed)
410 crtl->stack_alignment_estimated = alignment_in_bits;
411 else
412 {
413 /* If stack is realigned and stack alignment value
414 hasn't been finalized, it is OK not to increase
415 stack_alignment_estimated. The bigger alignment
416 requirement is recorded in stack_alignment_needed
417 below. */
418 gcc_assert (!crtl->stack_realign_finalized);
419 if (!crtl->stack_realign_needed)
420 {
421 /* It is OK to reduce the alignment as long as the
422 requested size is 0 or the estimated stack
423 alignment >= mode alignment. */
424 gcc_assert ((kind & ASLK_REDUCE_ALIGN)
425 || known_eq (size, 0)
426 || (crtl->stack_alignment_estimated
427 >= GET_MODE_ALIGNMENT (mode)));
428 alignment_in_bits = crtl->stack_alignment_estimated;
429 alignment = alignment_in_bits / BITS_PER_UNIT;
430 }
431 }
432 }
433 }
434
435 if (crtl->stack_alignment_needed < alignment_in_bits)
436 crtl->stack_alignment_needed = alignment_in_bits;
437 if (crtl->max_used_stack_slot_alignment < alignment_in_bits)
438 crtl->max_used_stack_slot_alignment = alignment_in_bits;
439
440 if (mode != BLKmode || maybe_ne (size, 0))
441 {
442 if (kind & ASLK_RECORD_PAD)
443 {
444 class frame_space **psp;
445
446 for (psp = &crtl->frame_space_list; *psp; psp = &(*psp)->next)
447 {
448 class frame_space *space = *psp;
449 if (!try_fit_stack_local (space->start, space->length, size,
450 alignment, &slot_offset))
451 continue;
452 *psp = space->next;
453 if (known_gt (slot_offset, space->start))
454 add_frame_space (space->start, slot_offset);
455 if (known_lt (slot_offset + size, space->start + space->length))
456 add_frame_space (slot_offset + size,
457 space->start + space->length);
458 goto found_space;
459 }
460 }
461 }
462 else if (!STACK_ALIGNMENT_NEEDED)
463 {
464 slot_offset = frame_offset;
465 goto found_space;
466 }
467
468 old_frame_offset = frame_offset;
469
470 if (FRAME_GROWS_DOWNWARD)
471 {
472 frame_offset -= size;
473 try_fit_stack_local (frame_offset, size, size, alignment, &slot_offset);
474
475 if (kind & ASLK_RECORD_PAD)
476 {
477 if (known_gt (slot_offset, frame_offset))
478 add_frame_space (frame_offset, slot_offset);
479 if (known_lt (slot_offset + size, old_frame_offset))
480 add_frame_space (slot_offset + size, old_frame_offset);
481 }
482 }
483 else
484 {
485 frame_offset += size;
486 try_fit_stack_local (old_frame_offset, size, size, alignment, &slot_offset);
487
488 if (kind & ASLK_RECORD_PAD)
489 {
490 if (known_gt (slot_offset, old_frame_offset))
491 add_frame_space (old_frame_offset, slot_offset);
492 if (known_lt (slot_offset + size, frame_offset))
493 add_frame_space (slot_offset + size, frame_offset);
494 }
495 }
496
497 found_space:
498 /* On a big-endian machine, if we are allocating more space than we will use,
499 use the least significant bytes of those that are allocated. */
500 if (mode != BLKmode)
501 {
502 /* The slot size can sometimes be smaller than the mode size;
503 e.g. the rs6000 port allocates slots with a vector mode
504 that have the size of only one element. However, the slot
505 size must always be ordered wrt to the mode size, in the
506 same way as for a subreg. */
507 gcc_checking_assert (ordered_p (GET_MODE_SIZE (mode), size));
508 if (BYTES_BIG_ENDIAN && maybe_lt (GET_MODE_SIZE (mode), size))
509 bigend_correction = size - GET_MODE_SIZE (mode);
510 }
511
512 /* If we have already instantiated virtual registers, return the actual
513 address relative to the frame pointer. */
514 if (virtuals_instantiated)
515 addr = plus_constant (Pmode, frame_pointer_rtx,
516 trunc_int_for_mode
517 (slot_offset + bigend_correction
518 + targetm.starting_frame_offset (), Pmode));
519 else
520 addr = plus_constant (Pmode, virtual_stack_vars_rtx,
521 trunc_int_for_mode
522 (slot_offset + bigend_correction,
523 Pmode));
524
525 x = gen_rtx_MEM (mode, addr);
526 set_mem_align (x, alignment_in_bits);
527 MEM_NOTRAP_P (x) = 1;
528
529 vec_safe_push (stack_slot_list, x);
530
531 if (frame_offset_overflow (frame_offset, current_function_decl))
532 frame_offset = 0;
533
534 return x;
535 }
536
537 /* Wrap up assign_stack_local_1 with last parameter as false. */
538
539 rtx
540 assign_stack_local (machine_mode mode, poly_int64 size, int align)
541 {
542 return assign_stack_local_1 (mode, size, align, ASLK_RECORD_PAD);
543 }
544 \f
545 /* In order to evaluate some expressions, such as function calls returning
546 structures in memory, we need to temporarily allocate stack locations.
547 We record each allocated temporary in the following structure.
548
549 Associated with each temporary slot is a nesting level. When we pop up
550 one level, all temporaries associated with the previous level are freed.
551 Normally, all temporaries are freed after the execution of the statement
552 in which they were created. However, if we are inside a ({...}) grouping,
553 the result may be in a temporary and hence must be preserved. If the
554 result could be in a temporary, we preserve it if we can determine which
555 one it is in. If we cannot determine which temporary may contain the
556 result, all temporaries are preserved. A temporary is preserved by
557 pretending it was allocated at the previous nesting level. */
558
559 class GTY(()) temp_slot {
560 public:
561 /* Points to next temporary slot. */
562 class temp_slot *next;
563 /* Points to previous temporary slot. */
564 class temp_slot *prev;
565 /* The rtx to used to reference the slot. */
566 rtx slot;
567 /* The size, in units, of the slot. */
568 poly_int64 size;
569 /* The type of the object in the slot, or zero if it doesn't correspond
570 to a type. We use this to determine whether a slot can be reused.
571 It can be reused if objects of the type of the new slot will always
572 conflict with objects of the type of the old slot. */
573 tree type;
574 /* The alignment (in bits) of the slot. */
575 unsigned int align;
576 /* Nonzero if this temporary is currently in use. */
577 char in_use;
578 /* Nesting level at which this slot is being used. */
579 int level;
580 /* The offset of the slot from the frame_pointer, including extra space
581 for alignment. This info is for combine_temp_slots. */
582 poly_int64 base_offset;
583 /* The size of the slot, including extra space for alignment. This
584 info is for combine_temp_slots. */
585 poly_int64 full_size;
586 };
587
588 /* Entry for the below hash table. */
589 struct GTY((for_user)) temp_slot_address_entry {
590 hashval_t hash;
591 rtx address;
592 class temp_slot *temp_slot;
593 };
594
595 struct temp_address_hasher : ggc_ptr_hash<temp_slot_address_entry>
596 {
597 static hashval_t hash (temp_slot_address_entry *);
598 static bool equal (temp_slot_address_entry *, temp_slot_address_entry *);
599 };
600
601 /* A table of addresses that represent a stack slot. The table is a mapping
602 from address RTXen to a temp slot. */
603 static GTY(()) hash_table<temp_address_hasher> *temp_slot_address_table;
604 static size_t n_temp_slots_in_use;
605
606 /* Removes temporary slot TEMP from LIST. */
607
608 static void
609 cut_slot_from_list (class temp_slot *temp, class temp_slot **list)
610 {
611 if (temp->next)
612 temp->next->prev = temp->prev;
613 if (temp->prev)
614 temp->prev->next = temp->next;
615 else
616 *list = temp->next;
617
618 temp->prev = temp->next = NULL;
619 }
620
621 /* Inserts temporary slot TEMP to LIST. */
622
623 static void
624 insert_slot_to_list (class temp_slot *temp, class temp_slot **list)
625 {
626 temp->next = *list;
627 if (*list)
628 (*list)->prev = temp;
629 temp->prev = NULL;
630 *list = temp;
631 }
632
633 /* Returns the list of used temp slots at LEVEL. */
634
635 static class temp_slot **
636 temp_slots_at_level (int level)
637 {
638 if (level >= (int) vec_safe_length (used_temp_slots))
639 vec_safe_grow_cleared (used_temp_slots, level + 1);
640
641 return &(*used_temp_slots)[level];
642 }
643
644 /* Returns the maximal temporary slot level. */
645
646 static int
647 max_slot_level (void)
648 {
649 if (!used_temp_slots)
650 return -1;
651
652 return used_temp_slots->length () - 1;
653 }
654
655 /* Moves temporary slot TEMP to LEVEL. */
656
657 static void
658 move_slot_to_level (class temp_slot *temp, int level)
659 {
660 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
661 insert_slot_to_list (temp, temp_slots_at_level (level));
662 temp->level = level;
663 }
664
665 /* Make temporary slot TEMP available. */
666
667 static void
668 make_slot_available (class temp_slot *temp)
669 {
670 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
671 insert_slot_to_list (temp, &avail_temp_slots);
672 temp->in_use = 0;
673 temp->level = -1;
674 n_temp_slots_in_use--;
675 }
676
677 /* Compute the hash value for an address -> temp slot mapping.
678 The value is cached on the mapping entry. */
679 static hashval_t
680 temp_slot_address_compute_hash (struct temp_slot_address_entry *t)
681 {
682 int do_not_record = 0;
683 return hash_rtx (t->address, GET_MODE (t->address),
684 &do_not_record, NULL, false);
685 }
686
687 /* Return the hash value for an address -> temp slot mapping. */
688 hashval_t
689 temp_address_hasher::hash (temp_slot_address_entry *t)
690 {
691 return t->hash;
692 }
693
694 /* Compare two address -> temp slot mapping entries. */
695 bool
696 temp_address_hasher::equal (temp_slot_address_entry *t1,
697 temp_slot_address_entry *t2)
698 {
699 return exp_equiv_p (t1->address, t2->address, 0, true);
700 }
701
702 /* Add ADDRESS as an alias of TEMP_SLOT to the addess -> temp slot mapping. */
703 static void
704 insert_temp_slot_address (rtx address, class temp_slot *temp_slot)
705 {
706 struct temp_slot_address_entry *t = ggc_alloc<temp_slot_address_entry> ();
707 t->address = copy_rtx (address);
708 t->temp_slot = temp_slot;
709 t->hash = temp_slot_address_compute_hash (t);
710 *temp_slot_address_table->find_slot_with_hash (t, t->hash, INSERT) = t;
711 }
712
713 /* Remove an address -> temp slot mapping entry if the temp slot is
714 not in use anymore. Callback for remove_unused_temp_slot_addresses. */
715 int
716 remove_unused_temp_slot_addresses_1 (temp_slot_address_entry **slot, void *)
717 {
718 const struct temp_slot_address_entry *t = *slot;
719 if (! t->temp_slot->in_use)
720 temp_slot_address_table->clear_slot (slot);
721 return 1;
722 }
723
724 /* Remove all mappings of addresses to unused temp slots. */
725 static void
726 remove_unused_temp_slot_addresses (void)
727 {
728 /* Use quicker clearing if there aren't any active temp slots. */
729 if (n_temp_slots_in_use)
730 temp_slot_address_table->traverse
731 <void *, remove_unused_temp_slot_addresses_1> (NULL);
732 else
733 temp_slot_address_table->empty ();
734 }
735
736 /* Find the temp slot corresponding to the object at address X. */
737
738 static class temp_slot *
739 find_temp_slot_from_address (rtx x)
740 {
741 class temp_slot *p;
742 struct temp_slot_address_entry tmp, *t;
743
744 /* First try the easy way:
745 See if X exists in the address -> temp slot mapping. */
746 tmp.address = x;
747 tmp.temp_slot = NULL;
748 tmp.hash = temp_slot_address_compute_hash (&tmp);
749 t = temp_slot_address_table->find_with_hash (&tmp, tmp.hash);
750 if (t)
751 return t->temp_slot;
752
753 /* If we have a sum involving a register, see if it points to a temp
754 slot. */
755 if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 0))
756 && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
757 return p;
758 else if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 1))
759 && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
760 return p;
761
762 /* Last resort: Address is a virtual stack var address. */
763 poly_int64 offset;
764 if (strip_offset (x, &offset) == virtual_stack_vars_rtx)
765 {
766 int i;
767 for (i = max_slot_level (); i >= 0; i--)
768 for (p = *temp_slots_at_level (i); p; p = p->next)
769 if (known_in_range_p (offset, p->base_offset, p->full_size))
770 return p;
771 }
772
773 return NULL;
774 }
775 \f
776 /* Allocate a temporary stack slot and record it for possible later
777 reuse.
778
779 MODE is the machine mode to be given to the returned rtx.
780
781 SIZE is the size in units of the space required. We do no rounding here
782 since assign_stack_local will do any required rounding.
783
784 TYPE is the type that will be used for the stack slot. */
785
786 rtx
787 assign_stack_temp_for_type (machine_mode mode, poly_int64 size, tree type)
788 {
789 unsigned int align;
790 class temp_slot *p, *best_p = 0, *selected = NULL, **pp;
791 rtx slot;
792
793 gcc_assert (known_size_p (size));
794
795 align = get_stack_local_alignment (type, mode);
796
797 /* Try to find an available, already-allocated temporary of the proper
798 mode which meets the size and alignment requirements. Choose the
799 smallest one with the closest alignment.
800
801 If assign_stack_temp is called outside of the tree->rtl expansion,
802 we cannot reuse the stack slots (that may still refer to
803 VIRTUAL_STACK_VARS_REGNUM). */
804 if (!virtuals_instantiated)
805 {
806 for (p = avail_temp_slots; p; p = p->next)
807 {
808 if (p->align >= align
809 && known_ge (p->size, size)
810 && GET_MODE (p->slot) == mode
811 && objects_must_conflict_p (p->type, type)
812 && (best_p == 0
813 || (known_eq (best_p->size, p->size)
814 ? best_p->align > p->align
815 : known_ge (best_p->size, p->size))))
816 {
817 if (p->align == align && known_eq (p->size, size))
818 {
819 selected = p;
820 cut_slot_from_list (selected, &avail_temp_slots);
821 best_p = 0;
822 break;
823 }
824 best_p = p;
825 }
826 }
827 }
828
829 /* Make our best, if any, the one to use. */
830 if (best_p)
831 {
832 selected = best_p;
833 cut_slot_from_list (selected, &avail_temp_slots);
834
835 /* If there are enough aligned bytes left over, make them into a new
836 temp_slot so that the extra bytes don't get wasted. Do this only
837 for BLKmode slots, so that we can be sure of the alignment. */
838 if (GET_MODE (best_p->slot) == BLKmode)
839 {
840 int alignment = best_p->align / BITS_PER_UNIT;
841 poly_int64 rounded_size = aligned_upper_bound (size, alignment);
842
843 if (known_ge (best_p->size - rounded_size, alignment))
844 {
845 p = ggc_alloc<temp_slot> ();
846 p->in_use = 0;
847 p->size = best_p->size - rounded_size;
848 p->base_offset = best_p->base_offset + rounded_size;
849 p->full_size = best_p->full_size - rounded_size;
850 p->slot = adjust_address_nv (best_p->slot, BLKmode, rounded_size);
851 p->align = best_p->align;
852 p->type = best_p->type;
853 insert_slot_to_list (p, &avail_temp_slots);
854
855 vec_safe_push (stack_slot_list, p->slot);
856
857 best_p->size = rounded_size;
858 best_p->full_size = rounded_size;
859 }
860 }
861 }
862
863 /* If we still didn't find one, make a new temporary. */
864 if (selected == 0)
865 {
866 poly_int64 frame_offset_old = frame_offset;
867
868 p = ggc_alloc<temp_slot> ();
869
870 /* We are passing an explicit alignment request to assign_stack_local.
871 One side effect of that is assign_stack_local will not round SIZE
872 to ensure the frame offset remains suitably aligned.
873
874 So for requests which depended on the rounding of SIZE, we go ahead
875 and round it now. We also make sure ALIGNMENT is at least
876 BIGGEST_ALIGNMENT. */
877 gcc_assert (mode != BLKmode || align == BIGGEST_ALIGNMENT);
878 p->slot = assign_stack_local_1 (mode,
879 (mode == BLKmode
880 ? aligned_upper_bound (size,
881 (int) align
882 / BITS_PER_UNIT)
883 : size),
884 align, 0);
885
886 p->align = align;
887
888 /* The following slot size computation is necessary because we don't
889 know the actual size of the temporary slot until assign_stack_local
890 has performed all the frame alignment and size rounding for the
891 requested temporary. Note that extra space added for alignment
892 can be either above or below this stack slot depending on which
893 way the frame grows. We include the extra space if and only if it
894 is above this slot. */
895 if (FRAME_GROWS_DOWNWARD)
896 p->size = frame_offset_old - frame_offset;
897 else
898 p->size = size;
899
900 /* Now define the fields used by combine_temp_slots. */
901 if (FRAME_GROWS_DOWNWARD)
902 {
903 p->base_offset = frame_offset;
904 p->full_size = frame_offset_old - frame_offset;
905 }
906 else
907 {
908 p->base_offset = frame_offset_old;
909 p->full_size = frame_offset - frame_offset_old;
910 }
911
912 selected = p;
913 }
914
915 p = selected;
916 p->in_use = 1;
917 p->type = type;
918 p->level = temp_slot_level;
919 n_temp_slots_in_use++;
920
921 pp = temp_slots_at_level (p->level);
922 insert_slot_to_list (p, pp);
923 insert_temp_slot_address (XEXP (p->slot, 0), p);
924
925 /* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
926 slot = gen_rtx_MEM (mode, XEXP (p->slot, 0));
927 vec_safe_push (stack_slot_list, slot);
928
929 /* If we know the alias set for the memory that will be used, use
930 it. If there's no TYPE, then we don't know anything about the
931 alias set for the memory. */
932 set_mem_alias_set (slot, type ? get_alias_set (type) : 0);
933 set_mem_align (slot, align);
934
935 /* If a type is specified, set the relevant flags. */
936 if (type != 0)
937 MEM_VOLATILE_P (slot) = TYPE_VOLATILE (type);
938 MEM_NOTRAP_P (slot) = 1;
939
940 return slot;
941 }
942
943 /* Allocate a temporary stack slot and record it for possible later
944 reuse. First two arguments are same as in preceding function. */
945
946 rtx
947 assign_stack_temp (machine_mode mode, poly_int64 size)
948 {
949 return assign_stack_temp_for_type (mode, size, NULL_TREE);
950 }
951 \f
952 /* Assign a temporary.
953 If TYPE_OR_DECL is a decl, then we are doing it on behalf of the decl
954 and so that should be used in error messages. In either case, we
955 allocate of the given type.
956 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
957 it is 0 if a register is OK.
958 DONT_PROMOTE is 1 if we should not promote values in register
959 to wider modes. */
960
961 rtx
962 assign_temp (tree type_or_decl, int memory_required,
963 int dont_promote ATTRIBUTE_UNUSED)
964 {
965 tree type, decl;
966 machine_mode mode;
967 #ifdef PROMOTE_MODE
968 int unsignedp;
969 #endif
970
971 if (DECL_P (type_or_decl))
972 decl = type_or_decl, type = TREE_TYPE (decl);
973 else
974 decl = NULL, type = type_or_decl;
975
976 mode = TYPE_MODE (type);
977 #ifdef PROMOTE_MODE
978 unsignedp = TYPE_UNSIGNED (type);
979 #endif
980
981 /* Allocating temporaries of TREE_ADDRESSABLE type must be done in the front
982 end. See also create_tmp_var for the gimplification-time check. */
983 gcc_assert (!TREE_ADDRESSABLE (type) && COMPLETE_TYPE_P (type));
984
985 if (mode == BLKmode || memory_required)
986 {
987 poly_int64 size;
988 rtx tmp;
989
990 /* Unfortunately, we don't yet know how to allocate variable-sized
991 temporaries. However, sometimes we can find a fixed upper limit on
992 the size, so try that instead. */
993 if (!poly_int_tree_p (TYPE_SIZE_UNIT (type), &size))
994 size = max_int_size_in_bytes (type);
995
996 /* Zero sized arrays are a GNU C extension. Set size to 1 to avoid
997 problems with allocating the stack space. */
998 if (known_eq (size, 0))
999 size = 1;
1000
1001 /* The size of the temporary may be too large to fit into an integer. */
1002 /* ??? Not sure this should happen except for user silliness, so limit
1003 this to things that aren't compiler-generated temporaries. The
1004 rest of the time we'll die in assign_stack_temp_for_type. */
1005 if (decl
1006 && !known_size_p (size)
1007 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST)
1008 {
1009 error ("size of variable %q+D is too large", decl);
1010 size = 1;
1011 }
1012
1013 tmp = assign_stack_temp_for_type (mode, size, type);
1014 return tmp;
1015 }
1016
1017 #ifdef PROMOTE_MODE
1018 if (! dont_promote)
1019 mode = promote_mode (type, mode, &unsignedp);
1020 #endif
1021
1022 return gen_reg_rtx (mode);
1023 }
1024 \f
1025 /* Combine temporary stack slots which are adjacent on the stack.
1026
1027 This allows for better use of already allocated stack space. This is only
1028 done for BLKmode slots because we can be sure that we won't have alignment
1029 problems in this case. */
1030
1031 static void
1032 combine_temp_slots (void)
1033 {
1034 class temp_slot *p, *q, *next, *next_q;
1035 int num_slots;
1036
1037 /* We can't combine slots, because the information about which slot
1038 is in which alias set will be lost. */
1039 if (flag_strict_aliasing)
1040 return;
1041
1042 /* If there are a lot of temp slots, don't do anything unless
1043 high levels of optimization. */
1044 if (! flag_expensive_optimizations)
1045 for (p = avail_temp_slots, num_slots = 0; p; p = p->next, num_slots++)
1046 if (num_slots > 100 || (num_slots > 10 && optimize == 0))
1047 return;
1048
1049 for (p = avail_temp_slots; p; p = next)
1050 {
1051 int delete_p = 0;
1052
1053 next = p->next;
1054
1055 if (GET_MODE (p->slot) != BLKmode)
1056 continue;
1057
1058 for (q = p->next; q; q = next_q)
1059 {
1060 int delete_q = 0;
1061
1062 next_q = q->next;
1063
1064 if (GET_MODE (q->slot) != BLKmode)
1065 continue;
1066
1067 if (known_eq (p->base_offset + p->full_size, q->base_offset))
1068 {
1069 /* Q comes after P; combine Q into P. */
1070 p->size += q->size;
1071 p->full_size += q->full_size;
1072 delete_q = 1;
1073 }
1074 else if (known_eq (q->base_offset + q->full_size, p->base_offset))
1075 {
1076 /* P comes after Q; combine P into Q. */
1077 q->size += p->size;
1078 q->full_size += p->full_size;
1079 delete_p = 1;
1080 break;
1081 }
1082 if (delete_q)
1083 cut_slot_from_list (q, &avail_temp_slots);
1084 }
1085
1086 /* Either delete P or advance past it. */
1087 if (delete_p)
1088 cut_slot_from_list (p, &avail_temp_slots);
1089 }
1090 }
1091 \f
1092 /* Indicate that NEW_RTX is an alternate way of referring to the temp
1093 slot that previously was known by OLD_RTX. */
1094
1095 void
1096 update_temp_slot_address (rtx old_rtx, rtx new_rtx)
1097 {
1098 class temp_slot *p;
1099
1100 if (rtx_equal_p (old_rtx, new_rtx))
1101 return;
1102
1103 p = find_temp_slot_from_address (old_rtx);
1104
1105 /* If we didn't find one, see if both OLD_RTX is a PLUS. If so, and
1106 NEW_RTX is a register, see if one operand of the PLUS is a
1107 temporary location. If so, NEW_RTX points into it. Otherwise,
1108 if both OLD_RTX and NEW_RTX are a PLUS and if there is a register
1109 in common between them. If so, try a recursive call on those
1110 values. */
1111 if (p == 0)
1112 {
1113 if (GET_CODE (old_rtx) != PLUS)
1114 return;
1115
1116 if (REG_P (new_rtx))
1117 {
1118 update_temp_slot_address (XEXP (old_rtx, 0), new_rtx);
1119 update_temp_slot_address (XEXP (old_rtx, 1), new_rtx);
1120 return;
1121 }
1122 else if (GET_CODE (new_rtx) != PLUS)
1123 return;
1124
1125 if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 0)))
1126 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 1));
1127 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 0)))
1128 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 1));
1129 else if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 1)))
1130 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 0));
1131 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 1)))
1132 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 0));
1133
1134 return;
1135 }
1136
1137 /* Otherwise add an alias for the temp's address. */
1138 insert_temp_slot_address (new_rtx, p);
1139 }
1140
1141 /* If X could be a reference to a temporary slot, mark that slot as
1142 belonging to the to one level higher than the current level. If X
1143 matched one of our slots, just mark that one. Otherwise, we can't
1144 easily predict which it is, so upgrade all of them.
1145
1146 This is called when an ({...}) construct occurs and a statement
1147 returns a value in memory. */
1148
1149 void
1150 preserve_temp_slots (rtx x)
1151 {
1152 class temp_slot *p = 0, *next;
1153
1154 if (x == 0)
1155 return;
1156
1157 /* If X is a register that is being used as a pointer, see if we have
1158 a temporary slot we know it points to. */
1159 if (REG_P (x) && REG_POINTER (x))
1160 p = find_temp_slot_from_address (x);
1161
1162 /* If X is not in memory or is at a constant address, it cannot be in
1163 a temporary slot. */
1164 if (p == 0 && (!MEM_P (x) || CONSTANT_P (XEXP (x, 0))))
1165 return;
1166
1167 /* First see if we can find a match. */
1168 if (p == 0)
1169 p = find_temp_slot_from_address (XEXP (x, 0));
1170
1171 if (p != 0)
1172 {
1173 if (p->level == temp_slot_level)
1174 move_slot_to_level (p, temp_slot_level - 1);
1175 return;
1176 }
1177
1178 /* Otherwise, preserve all non-kept slots at this level. */
1179 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1180 {
1181 next = p->next;
1182 move_slot_to_level (p, temp_slot_level - 1);
1183 }
1184 }
1185
1186 /* Free all temporaries used so far. This is normally called at the
1187 end of generating code for a statement. */
1188
1189 void
1190 free_temp_slots (void)
1191 {
1192 class temp_slot *p, *next;
1193 bool some_available = false;
1194
1195 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1196 {
1197 next = p->next;
1198 make_slot_available (p);
1199 some_available = true;
1200 }
1201
1202 if (some_available)
1203 {
1204 remove_unused_temp_slot_addresses ();
1205 combine_temp_slots ();
1206 }
1207 }
1208
1209 /* Push deeper into the nesting level for stack temporaries. */
1210
1211 void
1212 push_temp_slots (void)
1213 {
1214 temp_slot_level++;
1215 }
1216
1217 /* Pop a temporary nesting level. All slots in use in the current level
1218 are freed. */
1219
1220 void
1221 pop_temp_slots (void)
1222 {
1223 free_temp_slots ();
1224 temp_slot_level--;
1225 }
1226
1227 /* Initialize temporary slots. */
1228
1229 void
1230 init_temp_slots (void)
1231 {
1232 /* We have not allocated any temporaries yet. */
1233 avail_temp_slots = 0;
1234 vec_alloc (used_temp_slots, 0);
1235 temp_slot_level = 0;
1236 n_temp_slots_in_use = 0;
1237
1238 /* Set up the table to map addresses to temp slots. */
1239 if (! temp_slot_address_table)
1240 temp_slot_address_table = hash_table<temp_address_hasher>::create_ggc (32);
1241 else
1242 temp_slot_address_table->empty ();
1243 }
1244 \f
1245 /* Functions and data structures to keep track of the values hard regs
1246 had at the start of the function. */
1247
1248 /* Private type used by get_hard_reg_initial_reg, get_hard_reg_initial_val,
1249 and has_hard_reg_initial_val.. */
1250 struct GTY(()) initial_value_pair {
1251 rtx hard_reg;
1252 rtx pseudo;
1253 };
1254 /* ??? This could be a VEC but there is currently no way to define an
1255 opaque VEC type. This could be worked around by defining struct
1256 initial_value_pair in function.h. */
1257 struct GTY(()) initial_value_struct {
1258 int num_entries;
1259 int max_entries;
1260 initial_value_pair * GTY ((length ("%h.num_entries"))) entries;
1261 };
1262
1263 /* If a pseudo represents an initial hard reg (or expression), return
1264 it, else return NULL_RTX. */
1265
1266 rtx
1267 get_hard_reg_initial_reg (rtx reg)
1268 {
1269 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1270 int i;
1271
1272 if (ivs == 0)
1273 return NULL_RTX;
1274
1275 for (i = 0; i < ivs->num_entries; i++)
1276 if (rtx_equal_p (ivs->entries[i].pseudo, reg))
1277 return ivs->entries[i].hard_reg;
1278
1279 return NULL_RTX;
1280 }
1281
1282 /* Make sure that there's a pseudo register of mode MODE that stores the
1283 initial value of hard register REGNO. Return an rtx for such a pseudo. */
1284
1285 rtx
1286 get_hard_reg_initial_val (machine_mode mode, unsigned int regno)
1287 {
1288 struct initial_value_struct *ivs;
1289 rtx rv;
1290
1291 rv = has_hard_reg_initial_val (mode, regno);
1292 if (rv)
1293 return rv;
1294
1295 ivs = crtl->hard_reg_initial_vals;
1296 if (ivs == 0)
1297 {
1298 ivs = ggc_alloc<initial_value_struct> ();
1299 ivs->num_entries = 0;
1300 ivs->max_entries = 5;
1301 ivs->entries = ggc_vec_alloc<initial_value_pair> (5);
1302 crtl->hard_reg_initial_vals = ivs;
1303 }
1304
1305 if (ivs->num_entries >= ivs->max_entries)
1306 {
1307 ivs->max_entries += 5;
1308 ivs->entries = GGC_RESIZEVEC (initial_value_pair, ivs->entries,
1309 ivs->max_entries);
1310 }
1311
1312 ivs->entries[ivs->num_entries].hard_reg = gen_rtx_REG (mode, regno);
1313 ivs->entries[ivs->num_entries].pseudo = gen_reg_rtx (mode);
1314
1315 return ivs->entries[ivs->num_entries++].pseudo;
1316 }
1317
1318 /* See if get_hard_reg_initial_val has been used to create a pseudo
1319 for the initial value of hard register REGNO in mode MODE. Return
1320 the associated pseudo if so, otherwise return NULL. */
1321
1322 rtx
1323 has_hard_reg_initial_val (machine_mode mode, unsigned int regno)
1324 {
1325 struct initial_value_struct *ivs;
1326 int i;
1327
1328 ivs = crtl->hard_reg_initial_vals;
1329 if (ivs != 0)
1330 for (i = 0; i < ivs->num_entries; i++)
1331 if (GET_MODE (ivs->entries[i].hard_reg) == mode
1332 && REGNO (ivs->entries[i].hard_reg) == regno)
1333 return ivs->entries[i].pseudo;
1334
1335 return NULL_RTX;
1336 }
1337
1338 unsigned int
1339 emit_initial_value_sets (void)
1340 {
1341 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1342 int i;
1343 rtx_insn *seq;
1344
1345 if (ivs == 0)
1346 return 0;
1347
1348 start_sequence ();
1349 for (i = 0; i < ivs->num_entries; i++)
1350 emit_move_insn (ivs->entries[i].pseudo, ivs->entries[i].hard_reg);
1351 seq = get_insns ();
1352 end_sequence ();
1353
1354 emit_insn_at_entry (seq);
1355 return 0;
1356 }
1357
1358 /* Return the hardreg-pseudoreg initial values pair entry I and
1359 TRUE if I is a valid entry, or FALSE if I is not a valid entry. */
1360 bool
1361 initial_value_entry (int i, rtx *hreg, rtx *preg)
1362 {
1363 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1364 if (!ivs || i >= ivs->num_entries)
1365 return false;
1366
1367 *hreg = ivs->entries[i].hard_reg;
1368 *preg = ivs->entries[i].pseudo;
1369 return true;
1370 }
1371 \f
1372 /* These routines are responsible for converting virtual register references
1373 to the actual hard register references once RTL generation is complete.
1374
1375 The following four variables are used for communication between the
1376 routines. They contain the offsets of the virtual registers from their
1377 respective hard registers. */
1378
1379 static poly_int64 in_arg_offset;
1380 static poly_int64 var_offset;
1381 static poly_int64 dynamic_offset;
1382 static poly_int64 out_arg_offset;
1383 static poly_int64 cfa_offset;
1384
1385 /* In most machines, the stack pointer register is equivalent to the bottom
1386 of the stack. */
1387
1388 #ifndef STACK_POINTER_OFFSET
1389 #define STACK_POINTER_OFFSET 0
1390 #endif
1391
1392 #if defined (REG_PARM_STACK_SPACE) && !defined (INCOMING_REG_PARM_STACK_SPACE)
1393 #define INCOMING_REG_PARM_STACK_SPACE REG_PARM_STACK_SPACE
1394 #endif
1395
1396 /* If not defined, pick an appropriate default for the offset of dynamically
1397 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
1398 INCOMING_REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
1399
1400 #ifndef STACK_DYNAMIC_OFFSET
1401
1402 /* The bottom of the stack points to the actual arguments. If
1403 REG_PARM_STACK_SPACE is defined, this includes the space for the register
1404 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
1405 stack space for register parameters is not pushed by the caller, but
1406 rather part of the fixed stack areas and hence not included in
1407 `crtl->outgoing_args_size'. Nevertheless, we must allow
1408 for it when allocating stack dynamic objects. */
1409
1410 #ifdef INCOMING_REG_PARM_STACK_SPACE
1411 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1412 ((ACCUMULATE_OUTGOING_ARGS \
1413 ? (crtl->outgoing_args_size \
1414 + (OUTGOING_REG_PARM_STACK_SPACE ((!(FNDECL) ? NULL_TREE : TREE_TYPE (FNDECL))) ? 0 \
1415 : INCOMING_REG_PARM_STACK_SPACE (FNDECL))) \
1416 : 0) + (STACK_POINTER_OFFSET))
1417 #else
1418 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1419 ((ACCUMULATE_OUTGOING_ARGS ? crtl->outgoing_args_size : poly_int64 (0)) \
1420 + (STACK_POINTER_OFFSET))
1421 #endif
1422 #endif
1423
1424 \f
1425 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
1426 is a virtual register, return the equivalent hard register and set the
1427 offset indirectly through the pointer. Otherwise, return 0. */
1428
1429 static rtx
1430 instantiate_new_reg (rtx x, poly_int64_pod *poffset)
1431 {
1432 rtx new_rtx;
1433 poly_int64 offset;
1434
1435 if (x == virtual_incoming_args_rtx)
1436 {
1437 if (stack_realign_drap)
1438 {
1439 /* Replace virtual_incoming_args_rtx with internal arg
1440 pointer if DRAP is used to realign stack. */
1441 new_rtx = crtl->args.internal_arg_pointer;
1442 offset = 0;
1443 }
1444 else
1445 new_rtx = arg_pointer_rtx, offset = in_arg_offset;
1446 }
1447 else if (x == virtual_stack_vars_rtx)
1448 new_rtx = frame_pointer_rtx, offset = var_offset;
1449 else if (x == virtual_stack_dynamic_rtx)
1450 new_rtx = stack_pointer_rtx, offset = dynamic_offset;
1451 else if (x == virtual_outgoing_args_rtx)
1452 new_rtx = stack_pointer_rtx, offset = out_arg_offset;
1453 else if (x == virtual_cfa_rtx)
1454 {
1455 #ifdef FRAME_POINTER_CFA_OFFSET
1456 new_rtx = frame_pointer_rtx;
1457 #else
1458 new_rtx = arg_pointer_rtx;
1459 #endif
1460 offset = cfa_offset;
1461 }
1462 else if (x == virtual_preferred_stack_boundary_rtx)
1463 {
1464 new_rtx = GEN_INT (crtl->preferred_stack_boundary / BITS_PER_UNIT);
1465 offset = 0;
1466 }
1467 else
1468 return NULL_RTX;
1469
1470 *poffset = offset;
1471 return new_rtx;
1472 }
1473
1474 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1475 registers present inside of *LOC. The expression is simplified,
1476 as much as possible, but is not to be considered "valid" in any sense
1477 implied by the target. Return true if any change is made. */
1478
1479 static bool
1480 instantiate_virtual_regs_in_rtx (rtx *loc)
1481 {
1482 if (!*loc)
1483 return false;
1484 bool changed = false;
1485 subrtx_ptr_iterator::array_type array;
1486 FOR_EACH_SUBRTX_PTR (iter, array, loc, NONCONST)
1487 {
1488 rtx *loc = *iter;
1489 if (rtx x = *loc)
1490 {
1491 rtx new_rtx;
1492 poly_int64 offset;
1493 switch (GET_CODE (x))
1494 {
1495 case REG:
1496 new_rtx = instantiate_new_reg (x, &offset);
1497 if (new_rtx)
1498 {
1499 *loc = plus_constant (GET_MODE (x), new_rtx, offset);
1500 changed = true;
1501 }
1502 iter.skip_subrtxes ();
1503 break;
1504
1505 case PLUS:
1506 new_rtx = instantiate_new_reg (XEXP (x, 0), &offset);
1507 if (new_rtx)
1508 {
1509 XEXP (x, 0) = new_rtx;
1510 *loc = plus_constant (GET_MODE (x), x, offset, true);
1511 changed = true;
1512 iter.skip_subrtxes ();
1513 break;
1514 }
1515
1516 /* FIXME -- from old code */
1517 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
1518 we can commute the PLUS and SUBREG because pointers into the
1519 frame are well-behaved. */
1520 break;
1521
1522 default:
1523 break;
1524 }
1525 }
1526 }
1527 return changed;
1528 }
1529
1530 /* A subroutine of instantiate_virtual_regs_in_insn. Return true if X
1531 matches the predicate for insn CODE operand OPERAND. */
1532
1533 static int
1534 safe_insn_predicate (int code, int operand, rtx x)
1535 {
1536 return code < 0 || insn_operand_matches ((enum insn_code) code, operand, x);
1537 }
1538
1539 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1540 registers present inside of insn. The result will be a valid insn. */
1541
1542 static void
1543 instantiate_virtual_regs_in_insn (rtx_insn *insn)
1544 {
1545 poly_int64 offset;
1546 int insn_code, i;
1547 bool any_change = false;
1548 rtx set, new_rtx, x;
1549 rtx_insn *seq;
1550
1551 /* There are some special cases to be handled first. */
1552 set = single_set (insn);
1553 if (set)
1554 {
1555 /* We're allowed to assign to a virtual register. This is interpreted
1556 to mean that the underlying register gets assigned the inverse
1557 transformation. This is used, for example, in the handling of
1558 non-local gotos. */
1559 new_rtx = instantiate_new_reg (SET_DEST (set), &offset);
1560 if (new_rtx)
1561 {
1562 start_sequence ();
1563
1564 instantiate_virtual_regs_in_rtx (&SET_SRC (set));
1565 x = simplify_gen_binary (PLUS, GET_MODE (new_rtx), SET_SRC (set),
1566 gen_int_mode (-offset, GET_MODE (new_rtx)));
1567 x = force_operand (x, new_rtx);
1568 if (x != new_rtx)
1569 emit_move_insn (new_rtx, x);
1570
1571 seq = get_insns ();
1572 end_sequence ();
1573
1574 emit_insn_before (seq, insn);
1575 delete_insn (insn);
1576 return;
1577 }
1578
1579 /* Handle a straight copy from a virtual register by generating a
1580 new add insn. The difference between this and falling through
1581 to the generic case is avoiding a new pseudo and eliminating a
1582 move insn in the initial rtl stream. */
1583 new_rtx = instantiate_new_reg (SET_SRC (set), &offset);
1584 if (new_rtx
1585 && maybe_ne (offset, 0)
1586 && REG_P (SET_DEST (set))
1587 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1588 {
1589 start_sequence ();
1590
1591 x = expand_simple_binop (GET_MODE (SET_DEST (set)), PLUS, new_rtx,
1592 gen_int_mode (offset,
1593 GET_MODE (SET_DEST (set))),
1594 SET_DEST (set), 1, OPTAB_LIB_WIDEN);
1595 if (x != SET_DEST (set))
1596 emit_move_insn (SET_DEST (set), x);
1597
1598 seq = get_insns ();
1599 end_sequence ();
1600
1601 emit_insn_before (seq, insn);
1602 delete_insn (insn);
1603 return;
1604 }
1605
1606 extract_insn (insn);
1607 insn_code = INSN_CODE (insn);
1608
1609 /* Handle a plus involving a virtual register by determining if the
1610 operands remain valid if they're modified in place. */
1611 poly_int64 delta;
1612 if (GET_CODE (SET_SRC (set)) == PLUS
1613 && recog_data.n_operands >= 3
1614 && recog_data.operand_loc[1] == &XEXP (SET_SRC (set), 0)
1615 && recog_data.operand_loc[2] == &XEXP (SET_SRC (set), 1)
1616 && poly_int_rtx_p (recog_data.operand[2], &delta)
1617 && (new_rtx = instantiate_new_reg (recog_data.operand[1], &offset)))
1618 {
1619 offset += delta;
1620
1621 /* If the sum is zero, then replace with a plain move. */
1622 if (known_eq (offset, 0)
1623 && REG_P (SET_DEST (set))
1624 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1625 {
1626 start_sequence ();
1627 emit_move_insn (SET_DEST (set), new_rtx);
1628 seq = get_insns ();
1629 end_sequence ();
1630
1631 emit_insn_before (seq, insn);
1632 delete_insn (insn);
1633 return;
1634 }
1635
1636 x = gen_int_mode (offset, recog_data.operand_mode[2]);
1637
1638 /* Using validate_change and apply_change_group here leaves
1639 recog_data in an invalid state. Since we know exactly what
1640 we want to check, do those two by hand. */
1641 if (safe_insn_predicate (insn_code, 1, new_rtx)
1642 && safe_insn_predicate (insn_code, 2, x))
1643 {
1644 *recog_data.operand_loc[1] = recog_data.operand[1] = new_rtx;
1645 *recog_data.operand_loc[2] = recog_data.operand[2] = x;
1646 any_change = true;
1647
1648 /* Fall through into the regular operand fixup loop in
1649 order to take care of operands other than 1 and 2. */
1650 }
1651 }
1652 }
1653 else
1654 {
1655 extract_insn (insn);
1656 insn_code = INSN_CODE (insn);
1657 }
1658
1659 /* In the general case, we expect virtual registers to appear only in
1660 operands, and then only as either bare registers or inside memories. */
1661 for (i = 0; i < recog_data.n_operands; ++i)
1662 {
1663 x = recog_data.operand[i];
1664 switch (GET_CODE (x))
1665 {
1666 case MEM:
1667 {
1668 rtx addr = XEXP (x, 0);
1669
1670 if (!instantiate_virtual_regs_in_rtx (&addr))
1671 continue;
1672
1673 start_sequence ();
1674 x = replace_equiv_address (x, addr, true);
1675 /* It may happen that the address with the virtual reg
1676 was valid (e.g. based on the virtual stack reg, which might
1677 be acceptable to the predicates with all offsets), whereas
1678 the address now isn't anymore, for instance when the address
1679 is still offsetted, but the base reg isn't virtual-stack-reg
1680 anymore. Below we would do a force_reg on the whole operand,
1681 but this insn might actually only accept memory. Hence,
1682 before doing that last resort, try to reload the address into
1683 a register, so this operand stays a MEM. */
1684 if (!safe_insn_predicate (insn_code, i, x))
1685 {
1686 addr = force_reg (GET_MODE (addr), addr);
1687 x = replace_equiv_address (x, addr, true);
1688 }
1689 seq = get_insns ();
1690 end_sequence ();
1691 if (seq)
1692 emit_insn_before (seq, insn);
1693 }
1694 break;
1695
1696 case REG:
1697 new_rtx = instantiate_new_reg (x, &offset);
1698 if (new_rtx == NULL)
1699 continue;
1700 if (known_eq (offset, 0))
1701 x = new_rtx;
1702 else
1703 {
1704 start_sequence ();
1705
1706 /* Careful, special mode predicates may have stuff in
1707 insn_data[insn_code].operand[i].mode that isn't useful
1708 to us for computing a new value. */
1709 /* ??? Recognize address_operand and/or "p" constraints
1710 to see if (plus new offset) is a valid before we put
1711 this through expand_simple_binop. */
1712 x = expand_simple_binop (GET_MODE (x), PLUS, new_rtx,
1713 gen_int_mode (offset, GET_MODE (x)),
1714 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1715 seq = get_insns ();
1716 end_sequence ();
1717 emit_insn_before (seq, insn);
1718 }
1719 break;
1720
1721 case SUBREG:
1722 new_rtx = instantiate_new_reg (SUBREG_REG (x), &offset);
1723 if (new_rtx == NULL)
1724 continue;
1725 if (maybe_ne (offset, 0))
1726 {
1727 start_sequence ();
1728 new_rtx = expand_simple_binop
1729 (GET_MODE (new_rtx), PLUS, new_rtx,
1730 gen_int_mode (offset, GET_MODE (new_rtx)),
1731 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1732 seq = get_insns ();
1733 end_sequence ();
1734 emit_insn_before (seq, insn);
1735 }
1736 x = simplify_gen_subreg (recog_data.operand_mode[i], new_rtx,
1737 GET_MODE (new_rtx), SUBREG_BYTE (x));
1738 gcc_assert (x);
1739 break;
1740
1741 default:
1742 continue;
1743 }
1744
1745 /* At this point, X contains the new value for the operand.
1746 Validate the new value vs the insn predicate. Note that
1747 asm insns will have insn_code -1 here. */
1748 if (!safe_insn_predicate (insn_code, i, x))
1749 {
1750 start_sequence ();
1751 if (REG_P (x))
1752 {
1753 gcc_assert (REGNO (x) <= LAST_VIRTUAL_REGISTER);
1754 x = copy_to_reg (x);
1755 }
1756 else
1757 x = force_reg (insn_data[insn_code].operand[i].mode, x);
1758 seq = get_insns ();
1759 end_sequence ();
1760 if (seq)
1761 emit_insn_before (seq, insn);
1762 }
1763
1764 *recog_data.operand_loc[i] = recog_data.operand[i] = x;
1765 any_change = true;
1766 }
1767
1768 if (any_change)
1769 {
1770 /* Propagate operand changes into the duplicates. */
1771 for (i = 0; i < recog_data.n_dups; ++i)
1772 *recog_data.dup_loc[i]
1773 = copy_rtx (recog_data.operand[(unsigned)recog_data.dup_num[i]]);
1774
1775 /* Force re-recognition of the instruction for validation. */
1776 INSN_CODE (insn) = -1;
1777 }
1778
1779 if (asm_noperands (PATTERN (insn)) >= 0)
1780 {
1781 if (!check_asm_operands (PATTERN (insn)))
1782 {
1783 error_for_asm (insn, "impossible constraint in %<asm%>");
1784 /* For asm goto, instead of fixing up all the edges
1785 just clear the template and clear input operands
1786 (asm goto doesn't have any output operands). */
1787 if (JUMP_P (insn))
1788 {
1789 rtx asm_op = extract_asm_operands (PATTERN (insn));
1790 ASM_OPERANDS_TEMPLATE (asm_op) = ggc_strdup ("");
1791 ASM_OPERANDS_INPUT_VEC (asm_op) = rtvec_alloc (0);
1792 ASM_OPERANDS_INPUT_CONSTRAINT_VEC (asm_op) = rtvec_alloc (0);
1793 }
1794 else
1795 delete_insn (insn);
1796 }
1797 }
1798 else
1799 {
1800 if (recog_memoized (insn) < 0)
1801 fatal_insn_not_found (insn);
1802 }
1803 }
1804
1805 /* Subroutine of instantiate_decls. Given RTL representing a decl,
1806 do any instantiation required. */
1807
1808 void
1809 instantiate_decl_rtl (rtx x)
1810 {
1811 rtx addr;
1812
1813 if (x == 0)
1814 return;
1815
1816 /* If this is a CONCAT, recurse for the pieces. */
1817 if (GET_CODE (x) == CONCAT)
1818 {
1819 instantiate_decl_rtl (XEXP (x, 0));
1820 instantiate_decl_rtl (XEXP (x, 1));
1821 return;
1822 }
1823
1824 /* If this is not a MEM, no need to do anything. Similarly if the
1825 address is a constant or a register that is not a virtual register. */
1826 if (!MEM_P (x))
1827 return;
1828
1829 addr = XEXP (x, 0);
1830 if (CONSTANT_P (addr)
1831 || (REG_P (addr)
1832 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
1833 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
1834 return;
1835
1836 instantiate_virtual_regs_in_rtx (&XEXP (x, 0));
1837 }
1838
1839 /* Helper for instantiate_decls called via walk_tree: Process all decls
1840 in the given DECL_VALUE_EXPR. */
1841
1842 static tree
1843 instantiate_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1844 {
1845 tree t = *tp;
1846 if (! EXPR_P (t))
1847 {
1848 *walk_subtrees = 0;
1849 if (DECL_P (t))
1850 {
1851 if (DECL_RTL_SET_P (t))
1852 instantiate_decl_rtl (DECL_RTL (t));
1853 if (TREE_CODE (t) == PARM_DECL && DECL_NAMELESS (t)
1854 && DECL_INCOMING_RTL (t))
1855 instantiate_decl_rtl (DECL_INCOMING_RTL (t));
1856 if ((VAR_P (t) || TREE_CODE (t) == RESULT_DECL)
1857 && DECL_HAS_VALUE_EXPR_P (t))
1858 {
1859 tree v = DECL_VALUE_EXPR (t);
1860 walk_tree (&v, instantiate_expr, NULL, NULL);
1861 }
1862 }
1863 }
1864 return NULL;
1865 }
1866
1867 /* Subroutine of instantiate_decls: Process all decls in the given
1868 BLOCK node and all its subblocks. */
1869
1870 static void
1871 instantiate_decls_1 (tree let)
1872 {
1873 tree t;
1874
1875 for (t = BLOCK_VARS (let); t; t = DECL_CHAIN (t))
1876 {
1877 if (DECL_RTL_SET_P (t))
1878 instantiate_decl_rtl (DECL_RTL (t));
1879 if (VAR_P (t) && DECL_HAS_VALUE_EXPR_P (t))
1880 {
1881 tree v = DECL_VALUE_EXPR (t);
1882 walk_tree (&v, instantiate_expr, NULL, NULL);
1883 }
1884 }
1885
1886 /* Process all subblocks. */
1887 for (t = BLOCK_SUBBLOCKS (let); t; t = BLOCK_CHAIN (t))
1888 instantiate_decls_1 (t);
1889 }
1890
1891 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1892 all virtual registers in their DECL_RTL's. */
1893
1894 static void
1895 instantiate_decls (tree fndecl)
1896 {
1897 tree decl;
1898 unsigned ix;
1899
1900 /* Process all parameters of the function. */
1901 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = DECL_CHAIN (decl))
1902 {
1903 instantiate_decl_rtl (DECL_RTL (decl));
1904 instantiate_decl_rtl (DECL_INCOMING_RTL (decl));
1905 if (DECL_HAS_VALUE_EXPR_P (decl))
1906 {
1907 tree v = DECL_VALUE_EXPR (decl);
1908 walk_tree (&v, instantiate_expr, NULL, NULL);
1909 }
1910 }
1911
1912 if ((decl = DECL_RESULT (fndecl))
1913 && TREE_CODE (decl) == RESULT_DECL)
1914 {
1915 if (DECL_RTL_SET_P (decl))
1916 instantiate_decl_rtl (DECL_RTL (decl));
1917 if (DECL_HAS_VALUE_EXPR_P (decl))
1918 {
1919 tree v = DECL_VALUE_EXPR (decl);
1920 walk_tree (&v, instantiate_expr, NULL, NULL);
1921 }
1922 }
1923
1924 /* Process the saved static chain if it exists. */
1925 decl = DECL_STRUCT_FUNCTION (fndecl)->static_chain_decl;
1926 if (decl && DECL_HAS_VALUE_EXPR_P (decl))
1927 instantiate_decl_rtl (DECL_RTL (DECL_VALUE_EXPR (decl)));
1928
1929 /* Now process all variables defined in the function or its subblocks. */
1930 if (DECL_INITIAL (fndecl))
1931 instantiate_decls_1 (DECL_INITIAL (fndecl));
1932
1933 FOR_EACH_LOCAL_DECL (cfun, ix, decl)
1934 if (DECL_RTL_SET_P (decl))
1935 instantiate_decl_rtl (DECL_RTL (decl));
1936 vec_free (cfun->local_decls);
1937 }
1938
1939 /* Pass through the INSNS of function FNDECL and convert virtual register
1940 references to hard register references. */
1941
1942 static unsigned int
1943 instantiate_virtual_regs (void)
1944 {
1945 rtx_insn *insn;
1946
1947 /* Compute the offsets to use for this function. */
1948 in_arg_offset = FIRST_PARM_OFFSET (current_function_decl);
1949 var_offset = targetm.starting_frame_offset ();
1950 dynamic_offset = STACK_DYNAMIC_OFFSET (current_function_decl);
1951 out_arg_offset = STACK_POINTER_OFFSET;
1952 #ifdef FRAME_POINTER_CFA_OFFSET
1953 cfa_offset = FRAME_POINTER_CFA_OFFSET (current_function_decl);
1954 #else
1955 cfa_offset = ARG_POINTER_CFA_OFFSET (current_function_decl);
1956 #endif
1957
1958 /* Initialize recognition, indicating that volatile is OK. */
1959 init_recog ();
1960
1961 /* Scan through all the insns, instantiating every virtual register still
1962 present. */
1963 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
1964 if (INSN_P (insn))
1965 {
1966 /* These patterns in the instruction stream can never be recognized.
1967 Fortunately, they shouldn't contain virtual registers either. */
1968 if (GET_CODE (PATTERN (insn)) == USE
1969 || GET_CODE (PATTERN (insn)) == CLOBBER
1970 || GET_CODE (PATTERN (insn)) == ASM_INPUT
1971 || DEBUG_MARKER_INSN_P (insn))
1972 continue;
1973 else if (DEBUG_BIND_INSN_P (insn))
1974 instantiate_virtual_regs_in_rtx (INSN_VAR_LOCATION_PTR (insn));
1975 else
1976 instantiate_virtual_regs_in_insn (insn);
1977
1978 if (insn->deleted ())
1979 continue;
1980
1981 instantiate_virtual_regs_in_rtx (&REG_NOTES (insn));
1982
1983 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
1984 if (CALL_P (insn))
1985 instantiate_virtual_regs_in_rtx (&CALL_INSN_FUNCTION_USAGE (insn));
1986 }
1987
1988 /* Instantiate the virtual registers in the DECLs for debugging purposes. */
1989 instantiate_decls (current_function_decl);
1990
1991 targetm.instantiate_decls ();
1992
1993 /* Indicate that, from now on, assign_stack_local should use
1994 frame_pointer_rtx. */
1995 virtuals_instantiated = 1;
1996
1997 return 0;
1998 }
1999
2000 namespace {
2001
2002 const pass_data pass_data_instantiate_virtual_regs =
2003 {
2004 RTL_PASS, /* type */
2005 "vregs", /* name */
2006 OPTGROUP_NONE, /* optinfo_flags */
2007 TV_NONE, /* tv_id */
2008 0, /* properties_required */
2009 0, /* properties_provided */
2010 0, /* properties_destroyed */
2011 0, /* todo_flags_start */
2012 0, /* todo_flags_finish */
2013 };
2014
2015 class pass_instantiate_virtual_regs : public rtl_opt_pass
2016 {
2017 public:
2018 pass_instantiate_virtual_regs (gcc::context *ctxt)
2019 : rtl_opt_pass (pass_data_instantiate_virtual_regs, ctxt)
2020 {}
2021
2022 /* opt_pass methods: */
2023 virtual unsigned int execute (function *)
2024 {
2025 return instantiate_virtual_regs ();
2026 }
2027
2028 }; // class pass_instantiate_virtual_regs
2029
2030 } // anon namespace
2031
2032 rtl_opt_pass *
2033 make_pass_instantiate_virtual_regs (gcc::context *ctxt)
2034 {
2035 return new pass_instantiate_virtual_regs (ctxt);
2036 }
2037
2038 \f
2039 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
2040 This means a type for which function calls must pass an address to the
2041 function or get an address back from the function.
2042 EXP may be a type node or an expression (whose type is tested). */
2043
2044 int
2045 aggregate_value_p (const_tree exp, const_tree fntype)
2046 {
2047 const_tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
2048 int i, regno, nregs;
2049 rtx reg;
2050
2051 if (fntype)
2052 switch (TREE_CODE (fntype))
2053 {
2054 case CALL_EXPR:
2055 {
2056 tree fndecl = get_callee_fndecl (fntype);
2057 if (fndecl)
2058 fntype = TREE_TYPE (fndecl);
2059 else if (CALL_EXPR_FN (fntype))
2060 fntype = TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (fntype)));
2061 else
2062 /* For internal functions, assume nothing needs to be
2063 returned in memory. */
2064 return 0;
2065 }
2066 break;
2067 case FUNCTION_DECL:
2068 fntype = TREE_TYPE (fntype);
2069 break;
2070 case FUNCTION_TYPE:
2071 case METHOD_TYPE:
2072 break;
2073 case IDENTIFIER_NODE:
2074 fntype = NULL_TREE;
2075 break;
2076 default:
2077 /* We don't expect other tree types here. */
2078 gcc_unreachable ();
2079 }
2080
2081 if (VOID_TYPE_P (type))
2082 return 0;
2083
2084 /* If a record should be passed the same as its first (and only) member
2085 don't pass it as an aggregate. */
2086 if (TREE_CODE (type) == RECORD_TYPE && TYPE_TRANSPARENT_AGGR (type))
2087 return aggregate_value_p (first_field (type), fntype);
2088
2089 /* If the front end has decided that this needs to be passed by
2090 reference, do so. */
2091 if ((TREE_CODE (exp) == PARM_DECL || TREE_CODE (exp) == RESULT_DECL)
2092 && DECL_BY_REFERENCE (exp))
2093 return 1;
2094
2095 /* Function types that are TREE_ADDRESSABLE force return in memory. */
2096 if (fntype && TREE_ADDRESSABLE (fntype))
2097 return 1;
2098
2099 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
2100 and thus can't be returned in registers. */
2101 if (TREE_ADDRESSABLE (type))
2102 return 1;
2103
2104 if (TYPE_EMPTY_P (type))
2105 return 0;
2106
2107 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
2108 return 1;
2109
2110 if (targetm.calls.return_in_memory (type, fntype))
2111 return 1;
2112
2113 /* Make sure we have suitable call-clobbered regs to return
2114 the value in; if not, we must return it in memory. */
2115 reg = hard_function_value (type, 0, fntype, 0);
2116
2117 /* If we have something other than a REG (e.g. a PARALLEL), then assume
2118 it is OK. */
2119 if (!REG_P (reg))
2120 return 0;
2121
2122 regno = REGNO (reg);
2123 nregs = hard_regno_nregs (regno, TYPE_MODE (type));
2124 for (i = 0; i < nregs; i++)
2125 if (! call_used_regs[regno + i])
2126 return 1;
2127
2128 return 0;
2129 }
2130 \f
2131 /* Return true if we should assign DECL a pseudo register; false if it
2132 should live on the local stack. */
2133
2134 bool
2135 use_register_for_decl (const_tree decl)
2136 {
2137 if (TREE_CODE (decl) == SSA_NAME)
2138 {
2139 /* We often try to use the SSA_NAME, instead of its underlying
2140 decl, to get type information and guide decisions, to avoid
2141 differences of behavior between anonymous and named
2142 variables, but in this one case we have to go for the actual
2143 variable if there is one. The main reason is that, at least
2144 at -O0, we want to place user variables on the stack, but we
2145 don't mind using pseudos for anonymous or ignored temps.
2146 Should we take the SSA_NAME, we'd conclude all SSA_NAMEs
2147 should go in pseudos, whereas their corresponding variables
2148 might have to go on the stack. So, disregarding the decl
2149 here would negatively impact debug info at -O0, enable
2150 coalescing between SSA_NAMEs that ought to get different
2151 stack/pseudo assignments, and get the incoming argument
2152 processing thoroughly confused by PARM_DECLs expected to live
2153 in stack slots but assigned to pseudos. */
2154 if (!SSA_NAME_VAR (decl))
2155 return TYPE_MODE (TREE_TYPE (decl)) != BLKmode
2156 && !(flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)));
2157
2158 decl = SSA_NAME_VAR (decl);
2159 }
2160
2161 /* Honor volatile. */
2162 if (TREE_SIDE_EFFECTS (decl))
2163 return false;
2164
2165 /* Honor addressability. */
2166 if (TREE_ADDRESSABLE (decl))
2167 return false;
2168
2169 /* RESULT_DECLs are a bit special in that they're assigned without
2170 regard to use_register_for_decl, but we generally only store in
2171 them. If we coalesce their SSA NAMEs, we'd better return a
2172 result that matches the assignment in expand_function_start. */
2173 if (TREE_CODE (decl) == RESULT_DECL)
2174 {
2175 /* If it's not an aggregate, we're going to use a REG or a
2176 PARALLEL containing a REG. */
2177 if (!aggregate_value_p (decl, current_function_decl))
2178 return true;
2179
2180 /* If expand_function_start determines the return value, we'll
2181 use MEM if it's not by reference. */
2182 if (cfun->returns_pcc_struct
2183 || (targetm.calls.struct_value_rtx
2184 (TREE_TYPE (current_function_decl), 1)))
2185 return DECL_BY_REFERENCE (decl);
2186
2187 /* Otherwise, we're taking an extra all.function_result_decl
2188 argument. It's set up in assign_parms_augmented_arg_list,
2189 under the (negated) conditions above, and then it's used to
2190 set up the RESULT_DECL rtl in assign_params, after looping
2191 over all parameters. Now, if the RESULT_DECL is not by
2192 reference, we'll use a MEM either way. */
2193 if (!DECL_BY_REFERENCE (decl))
2194 return false;
2195
2196 /* Otherwise, if RESULT_DECL is DECL_BY_REFERENCE, it will take
2197 the function_result_decl's assignment. Since it's a pointer,
2198 we can short-circuit a number of the tests below, and we must
2199 duplicat e them because we don't have the
2200 function_result_decl to test. */
2201 if (!targetm.calls.allocate_stack_slots_for_args ())
2202 return true;
2203 /* We don't set DECL_IGNORED_P for the function_result_decl. */
2204 if (optimize)
2205 return true;
2206 /* We don't set DECL_REGISTER for the function_result_decl. */
2207 return false;
2208 }
2209
2210 /* Only register-like things go in registers. */
2211 if (DECL_MODE (decl) == BLKmode)
2212 return false;
2213
2214 /* If -ffloat-store specified, don't put explicit float variables
2215 into registers. */
2216 /* ??? This should be checked after DECL_ARTIFICIAL, but tree-ssa
2217 propagates values across these stores, and it probably shouldn't. */
2218 if (flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)))
2219 return false;
2220
2221 if (!targetm.calls.allocate_stack_slots_for_args ())
2222 return true;
2223
2224 /* If we're not interested in tracking debugging information for
2225 this decl, then we can certainly put it in a register. */
2226 if (DECL_IGNORED_P (decl))
2227 return true;
2228
2229 if (optimize)
2230 return true;
2231
2232 if (!DECL_REGISTER (decl))
2233 return false;
2234
2235 /* When not optimizing, disregard register keyword for types that
2236 could have methods, otherwise the methods won't be callable from
2237 the debugger. */
2238 if (RECORD_OR_UNION_TYPE_P (TREE_TYPE (decl)))
2239 return false;
2240
2241 return true;
2242 }
2243
2244 /* Structures to communicate between the subroutines of assign_parms.
2245 The first holds data persistent across all parameters, the second
2246 is cleared out for each parameter. */
2247
2248 struct assign_parm_data_all
2249 {
2250 /* When INIT_CUMULATIVE_ARGS gets revamped, allocating CUMULATIVE_ARGS
2251 should become a job of the target or otherwise encapsulated. */
2252 CUMULATIVE_ARGS args_so_far_v;
2253 cumulative_args_t args_so_far;
2254 struct args_size stack_args_size;
2255 tree function_result_decl;
2256 tree orig_fnargs;
2257 rtx_insn *first_conversion_insn;
2258 rtx_insn *last_conversion_insn;
2259 HOST_WIDE_INT pretend_args_size;
2260 HOST_WIDE_INT extra_pretend_bytes;
2261 int reg_parm_stack_space;
2262 };
2263
2264 struct assign_parm_data_one
2265 {
2266 tree nominal_type;
2267 tree passed_type;
2268 rtx entry_parm;
2269 rtx stack_parm;
2270 machine_mode nominal_mode;
2271 machine_mode passed_mode;
2272 machine_mode promoted_mode;
2273 struct locate_and_pad_arg_data locate;
2274 int partial;
2275 BOOL_BITFIELD named_arg : 1;
2276 BOOL_BITFIELD passed_pointer : 1;
2277 };
2278
2279 /* A subroutine of assign_parms. Initialize ALL. */
2280
2281 static void
2282 assign_parms_initialize_all (struct assign_parm_data_all *all)
2283 {
2284 tree fntype ATTRIBUTE_UNUSED;
2285
2286 memset (all, 0, sizeof (*all));
2287
2288 fntype = TREE_TYPE (current_function_decl);
2289
2290 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
2291 INIT_CUMULATIVE_INCOMING_ARGS (all->args_so_far_v, fntype, NULL_RTX);
2292 #else
2293 INIT_CUMULATIVE_ARGS (all->args_so_far_v, fntype, NULL_RTX,
2294 current_function_decl, -1);
2295 #endif
2296 all->args_so_far = pack_cumulative_args (&all->args_so_far_v);
2297
2298 #ifdef INCOMING_REG_PARM_STACK_SPACE
2299 all->reg_parm_stack_space
2300 = INCOMING_REG_PARM_STACK_SPACE (current_function_decl);
2301 #endif
2302 }
2303
2304 /* If ARGS contains entries with complex types, split the entry into two
2305 entries of the component type. Return a new list of substitutions are
2306 needed, else the old list. */
2307
2308 static void
2309 split_complex_args (vec<tree> *args)
2310 {
2311 unsigned i;
2312 tree p;
2313
2314 FOR_EACH_VEC_ELT (*args, i, p)
2315 {
2316 tree type = TREE_TYPE (p);
2317 if (TREE_CODE (type) == COMPLEX_TYPE
2318 && targetm.calls.split_complex_arg (type))
2319 {
2320 tree decl;
2321 tree subtype = TREE_TYPE (type);
2322 bool addressable = TREE_ADDRESSABLE (p);
2323
2324 /* Rewrite the PARM_DECL's type with its component. */
2325 p = copy_node (p);
2326 TREE_TYPE (p) = subtype;
2327 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
2328 SET_DECL_MODE (p, VOIDmode);
2329 DECL_SIZE (p) = NULL;
2330 DECL_SIZE_UNIT (p) = NULL;
2331 /* If this arg must go in memory, put it in a pseudo here.
2332 We can't allow it to go in memory as per normal parms,
2333 because the usual place might not have the imag part
2334 adjacent to the real part. */
2335 DECL_ARTIFICIAL (p) = addressable;
2336 DECL_IGNORED_P (p) = addressable;
2337 TREE_ADDRESSABLE (p) = 0;
2338 layout_decl (p, 0);
2339 (*args)[i] = p;
2340
2341 /* Build a second synthetic decl. */
2342 decl = build_decl (EXPR_LOCATION (p),
2343 PARM_DECL, NULL_TREE, subtype);
2344 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
2345 DECL_ARTIFICIAL (decl) = addressable;
2346 DECL_IGNORED_P (decl) = addressable;
2347 layout_decl (decl, 0);
2348 args->safe_insert (++i, decl);
2349 }
2350 }
2351 }
2352
2353 /* A subroutine of assign_parms. Adjust the parameter list to incorporate
2354 the hidden struct return argument, and (abi willing) complex args.
2355 Return the new parameter list. */
2356
2357 static vec<tree>
2358 assign_parms_augmented_arg_list (struct assign_parm_data_all *all)
2359 {
2360 tree fndecl = current_function_decl;
2361 tree fntype = TREE_TYPE (fndecl);
2362 vec<tree> fnargs = vNULL;
2363 tree arg;
2364
2365 for (arg = DECL_ARGUMENTS (fndecl); arg; arg = DECL_CHAIN (arg))
2366 fnargs.safe_push (arg);
2367
2368 all->orig_fnargs = DECL_ARGUMENTS (fndecl);
2369
2370 /* If struct value address is treated as the first argument, make it so. */
2371 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
2372 && ! cfun->returns_pcc_struct
2373 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
2374 {
2375 tree type = build_pointer_type (TREE_TYPE (fntype));
2376 tree decl;
2377
2378 decl = build_decl (DECL_SOURCE_LOCATION (fndecl),
2379 PARM_DECL, get_identifier (".result_ptr"), type);
2380 DECL_ARG_TYPE (decl) = type;
2381 DECL_ARTIFICIAL (decl) = 1;
2382 DECL_NAMELESS (decl) = 1;
2383 TREE_CONSTANT (decl) = 1;
2384 /* We don't set DECL_IGNORED_P or DECL_REGISTER here. If this
2385 changes, the end of the RESULT_DECL handling block in
2386 use_register_for_decl must be adjusted to match. */
2387
2388 DECL_CHAIN (decl) = all->orig_fnargs;
2389 all->orig_fnargs = decl;
2390 fnargs.safe_insert (0, decl);
2391
2392 all->function_result_decl = decl;
2393 }
2394
2395 /* If the target wants to split complex arguments into scalars, do so. */
2396 if (targetm.calls.split_complex_arg)
2397 split_complex_args (&fnargs);
2398
2399 return fnargs;
2400 }
2401
2402 /* A subroutine of assign_parms. Examine PARM and pull out type and mode
2403 data for the parameter. Incorporate ABI specifics such as pass-by-
2404 reference and type promotion. */
2405
2406 static void
2407 assign_parm_find_data_types (struct assign_parm_data_all *all, tree parm,
2408 struct assign_parm_data_one *data)
2409 {
2410 tree nominal_type, passed_type;
2411 machine_mode nominal_mode, passed_mode, promoted_mode;
2412 int unsignedp;
2413
2414 memset (data, 0, sizeof (*data));
2415
2416 /* NAMED_ARG is a misnomer. We really mean 'non-variadic'. */
2417 if (!cfun->stdarg)
2418 data->named_arg = 1; /* No variadic parms. */
2419 else if (DECL_CHAIN (parm))
2420 data->named_arg = 1; /* Not the last non-variadic parm. */
2421 else if (targetm.calls.strict_argument_naming (all->args_so_far))
2422 data->named_arg = 1; /* Only variadic ones are unnamed. */
2423 else
2424 data->named_arg = 0; /* Treat as variadic. */
2425
2426 nominal_type = TREE_TYPE (parm);
2427 passed_type = DECL_ARG_TYPE (parm);
2428
2429 /* Look out for errors propagating this far. Also, if the parameter's
2430 type is void then its value doesn't matter. */
2431 if (TREE_TYPE (parm) == error_mark_node
2432 /* This can happen after weird syntax errors
2433 or if an enum type is defined among the parms. */
2434 || TREE_CODE (parm) != PARM_DECL
2435 || passed_type == NULL
2436 || VOID_TYPE_P (nominal_type))
2437 {
2438 nominal_type = passed_type = void_type_node;
2439 nominal_mode = passed_mode = promoted_mode = VOIDmode;
2440 goto egress;
2441 }
2442
2443 /* Find mode of arg as it is passed, and mode of arg as it should be
2444 during execution of this function. */
2445 passed_mode = TYPE_MODE (passed_type);
2446 nominal_mode = TYPE_MODE (nominal_type);
2447
2448 /* If the parm is to be passed as a transparent union or record, use the
2449 type of the first field for the tests below. We have already verified
2450 that the modes are the same. */
2451 if ((TREE_CODE (passed_type) == UNION_TYPE
2452 || TREE_CODE (passed_type) == RECORD_TYPE)
2453 && TYPE_TRANSPARENT_AGGR (passed_type))
2454 passed_type = TREE_TYPE (first_field (passed_type));
2455
2456 /* See if this arg was passed by invisible reference. */
2457 if (pass_by_reference (&all->args_so_far_v, passed_mode,
2458 passed_type, data->named_arg))
2459 {
2460 passed_type = nominal_type = build_pointer_type (passed_type);
2461 data->passed_pointer = true;
2462 passed_mode = nominal_mode = TYPE_MODE (nominal_type);
2463 }
2464
2465 /* Find mode as it is passed by the ABI. */
2466 unsignedp = TYPE_UNSIGNED (passed_type);
2467 promoted_mode = promote_function_mode (passed_type, passed_mode, &unsignedp,
2468 TREE_TYPE (current_function_decl), 0);
2469
2470 egress:
2471 data->nominal_type = nominal_type;
2472 data->passed_type = passed_type;
2473 data->nominal_mode = nominal_mode;
2474 data->passed_mode = passed_mode;
2475 data->promoted_mode = promoted_mode;
2476 }
2477
2478 /* A subroutine of assign_parms. Invoke setup_incoming_varargs. */
2479
2480 static void
2481 assign_parms_setup_varargs (struct assign_parm_data_all *all,
2482 struct assign_parm_data_one *data, bool no_rtl)
2483 {
2484 int varargs_pretend_bytes = 0;
2485
2486 targetm.calls.setup_incoming_varargs (all->args_so_far,
2487 data->promoted_mode,
2488 data->passed_type,
2489 &varargs_pretend_bytes, no_rtl);
2490
2491 /* If the back-end has requested extra stack space, record how much is
2492 needed. Do not change pretend_args_size otherwise since it may be
2493 nonzero from an earlier partial argument. */
2494 if (varargs_pretend_bytes > 0)
2495 all->pretend_args_size = varargs_pretend_bytes;
2496 }
2497
2498 /* A subroutine of assign_parms. Set DATA->ENTRY_PARM corresponding to
2499 the incoming location of the current parameter. */
2500
2501 static void
2502 assign_parm_find_entry_rtl (struct assign_parm_data_all *all,
2503 struct assign_parm_data_one *data)
2504 {
2505 HOST_WIDE_INT pretend_bytes = 0;
2506 rtx entry_parm;
2507 bool in_regs;
2508
2509 if (data->promoted_mode == VOIDmode)
2510 {
2511 data->entry_parm = data->stack_parm = const0_rtx;
2512 return;
2513 }
2514
2515 targetm.calls.warn_parameter_passing_abi (all->args_so_far,
2516 data->passed_type);
2517
2518 entry_parm = targetm.calls.function_incoming_arg (all->args_so_far,
2519 data->promoted_mode,
2520 data->passed_type,
2521 data->named_arg);
2522
2523 if (entry_parm == 0)
2524 data->promoted_mode = data->passed_mode;
2525
2526 /* Determine parm's home in the stack, in case it arrives in the stack
2527 or we should pretend it did. Compute the stack position and rtx where
2528 the argument arrives and its size.
2529
2530 There is one complexity here: If this was a parameter that would
2531 have been passed in registers, but wasn't only because it is
2532 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2533 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2534 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of 0
2535 as it was the previous time. */
2536 in_regs = (entry_parm != 0);
2537 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2538 in_regs = true;
2539 #endif
2540 if (!in_regs && !data->named_arg)
2541 {
2542 if (targetm.calls.pretend_outgoing_varargs_named (all->args_so_far))
2543 {
2544 rtx tem;
2545 tem = targetm.calls.function_incoming_arg (all->args_so_far,
2546 data->promoted_mode,
2547 data->passed_type, true);
2548 in_regs = tem != NULL;
2549 }
2550 }
2551
2552 /* If this parameter was passed both in registers and in the stack, use
2553 the copy on the stack. */
2554 if (targetm.calls.must_pass_in_stack (data->promoted_mode,
2555 data->passed_type))
2556 entry_parm = 0;
2557
2558 if (entry_parm)
2559 {
2560 int partial;
2561
2562 partial = targetm.calls.arg_partial_bytes (all->args_so_far,
2563 data->promoted_mode,
2564 data->passed_type,
2565 data->named_arg);
2566 data->partial = partial;
2567
2568 /* The caller might already have allocated stack space for the
2569 register parameters. */
2570 if (partial != 0 && all->reg_parm_stack_space == 0)
2571 {
2572 /* Part of this argument is passed in registers and part
2573 is passed on the stack. Ask the prologue code to extend
2574 the stack part so that we can recreate the full value.
2575
2576 PRETEND_BYTES is the size of the registers we need to store.
2577 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
2578 stack space that the prologue should allocate.
2579
2580 Internally, gcc assumes that the argument pointer is aligned
2581 to STACK_BOUNDARY bits. This is used both for alignment
2582 optimizations (see init_emit) and to locate arguments that are
2583 aligned to more than PARM_BOUNDARY bits. We must preserve this
2584 invariant by rounding CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to
2585 a stack boundary. */
2586
2587 /* We assume at most one partial arg, and it must be the first
2588 argument on the stack. */
2589 gcc_assert (!all->extra_pretend_bytes && !all->pretend_args_size);
2590
2591 pretend_bytes = partial;
2592 all->pretend_args_size = CEIL_ROUND (pretend_bytes, STACK_BYTES);
2593
2594 /* We want to align relative to the actual stack pointer, so
2595 don't include this in the stack size until later. */
2596 all->extra_pretend_bytes = all->pretend_args_size;
2597 }
2598 }
2599
2600 locate_and_pad_parm (data->promoted_mode, data->passed_type, in_regs,
2601 all->reg_parm_stack_space,
2602 entry_parm ? data->partial : 0, current_function_decl,
2603 &all->stack_args_size, &data->locate);
2604
2605 /* Update parm_stack_boundary if this parameter is passed in the
2606 stack. */
2607 if (!in_regs && crtl->parm_stack_boundary < data->locate.boundary)
2608 crtl->parm_stack_boundary = data->locate.boundary;
2609
2610 /* Adjust offsets to include the pretend args. */
2611 pretend_bytes = all->extra_pretend_bytes - pretend_bytes;
2612 data->locate.slot_offset.constant += pretend_bytes;
2613 data->locate.offset.constant += pretend_bytes;
2614
2615 data->entry_parm = entry_parm;
2616 }
2617
2618 /* A subroutine of assign_parms. If there is actually space on the stack
2619 for this parm, count it in stack_args_size and return true. */
2620
2621 static bool
2622 assign_parm_is_stack_parm (struct assign_parm_data_all *all,
2623 struct assign_parm_data_one *data)
2624 {
2625 /* Trivially true if we've no incoming register. */
2626 if (data->entry_parm == NULL)
2627 ;
2628 /* Also true if we're partially in registers and partially not,
2629 since we've arranged to drop the entire argument on the stack. */
2630 else if (data->partial != 0)
2631 ;
2632 /* Also true if the target says that it's passed in both registers
2633 and on the stack. */
2634 else if (GET_CODE (data->entry_parm) == PARALLEL
2635 && XEXP (XVECEXP (data->entry_parm, 0, 0), 0) == NULL_RTX)
2636 ;
2637 /* Also true if the target says that there's stack allocated for
2638 all register parameters. */
2639 else if (all->reg_parm_stack_space > 0)
2640 ;
2641 /* Otherwise, no, this parameter has no ABI defined stack slot. */
2642 else
2643 return false;
2644
2645 all->stack_args_size.constant += data->locate.size.constant;
2646 if (data->locate.size.var)
2647 ADD_PARM_SIZE (all->stack_args_size, data->locate.size.var);
2648
2649 return true;
2650 }
2651
2652 /* A subroutine of assign_parms. Given that this parameter is allocated
2653 stack space by the ABI, find it. */
2654
2655 static void
2656 assign_parm_find_stack_rtl (tree parm, struct assign_parm_data_one *data)
2657 {
2658 rtx offset_rtx, stack_parm;
2659 unsigned int align, boundary;
2660
2661 /* If we're passing this arg using a reg, make its stack home the
2662 aligned stack slot. */
2663 if (data->entry_parm)
2664 offset_rtx = ARGS_SIZE_RTX (data->locate.slot_offset);
2665 else
2666 offset_rtx = ARGS_SIZE_RTX (data->locate.offset);
2667
2668 stack_parm = crtl->args.internal_arg_pointer;
2669 if (offset_rtx != const0_rtx)
2670 stack_parm = gen_rtx_PLUS (Pmode, stack_parm, offset_rtx);
2671 stack_parm = gen_rtx_MEM (data->promoted_mode, stack_parm);
2672
2673 if (!data->passed_pointer)
2674 {
2675 set_mem_attributes (stack_parm, parm, 1);
2676 /* set_mem_attributes could set MEM_SIZE to the passed mode's size,
2677 while promoted mode's size is needed. */
2678 if (data->promoted_mode != BLKmode
2679 && data->promoted_mode != DECL_MODE (parm))
2680 {
2681 set_mem_size (stack_parm, GET_MODE_SIZE (data->promoted_mode));
2682 if (MEM_EXPR (stack_parm) && MEM_OFFSET_KNOWN_P (stack_parm))
2683 {
2684 poly_int64 offset = subreg_lowpart_offset (DECL_MODE (parm),
2685 data->promoted_mode);
2686 if (maybe_ne (offset, 0))
2687 set_mem_offset (stack_parm, MEM_OFFSET (stack_parm) - offset);
2688 }
2689 }
2690 }
2691
2692 boundary = data->locate.boundary;
2693 align = BITS_PER_UNIT;
2694
2695 /* If we're padding upward, we know that the alignment of the slot
2696 is TARGET_FUNCTION_ARG_BOUNDARY. If we're using slot_offset, we're
2697 intentionally forcing upward padding. Otherwise we have to come
2698 up with a guess at the alignment based on OFFSET_RTX. */
2699 poly_int64 offset;
2700 if (data->locate.where_pad == PAD_NONE || data->entry_parm)
2701 align = boundary;
2702 else if (data->locate.where_pad == PAD_UPWARD)
2703 {
2704 align = boundary;
2705 /* If the argument offset is actually more aligned than the nominal
2706 stack slot boundary, take advantage of that excess alignment.
2707 Don't make any assumptions if STACK_POINTER_OFFSET is in use. */
2708 if (poly_int_rtx_p (offset_rtx, &offset)
2709 && STACK_POINTER_OFFSET == 0)
2710 {
2711 unsigned int offset_align = known_alignment (offset) * BITS_PER_UNIT;
2712 if (offset_align == 0 || offset_align > STACK_BOUNDARY)
2713 offset_align = STACK_BOUNDARY;
2714 align = MAX (align, offset_align);
2715 }
2716 }
2717 else if (poly_int_rtx_p (offset_rtx, &offset))
2718 {
2719 align = least_bit_hwi (boundary);
2720 unsigned int offset_align = known_alignment (offset) * BITS_PER_UNIT;
2721 if (offset_align != 0)
2722 align = MIN (align, offset_align);
2723 }
2724 set_mem_align (stack_parm, align);
2725
2726 if (data->entry_parm)
2727 set_reg_attrs_for_parm (data->entry_parm, stack_parm);
2728
2729 data->stack_parm = stack_parm;
2730 }
2731
2732 /* A subroutine of assign_parms. Adjust DATA->ENTRY_RTL such that it's
2733 always valid and contiguous. */
2734
2735 static void
2736 assign_parm_adjust_entry_rtl (struct assign_parm_data_one *data)
2737 {
2738 rtx entry_parm = data->entry_parm;
2739 rtx stack_parm = data->stack_parm;
2740
2741 /* If this parm was passed part in regs and part in memory, pretend it
2742 arrived entirely in memory by pushing the register-part onto the stack.
2743 In the special case of a DImode or DFmode that is split, we could put
2744 it together in a pseudoreg directly, but for now that's not worth
2745 bothering with. */
2746 if (data->partial != 0)
2747 {
2748 /* Handle calls that pass values in multiple non-contiguous
2749 locations. The Irix 6 ABI has examples of this. */
2750 if (GET_CODE (entry_parm) == PARALLEL)
2751 emit_group_store (validize_mem (copy_rtx (stack_parm)), entry_parm,
2752 data->passed_type,
2753 int_size_in_bytes (data->passed_type));
2754 else
2755 {
2756 gcc_assert (data->partial % UNITS_PER_WORD == 0);
2757 move_block_from_reg (REGNO (entry_parm),
2758 validize_mem (copy_rtx (stack_parm)),
2759 data->partial / UNITS_PER_WORD);
2760 }
2761
2762 entry_parm = stack_parm;
2763 }
2764
2765 /* If we didn't decide this parm came in a register, by default it came
2766 on the stack. */
2767 else if (entry_parm == NULL)
2768 entry_parm = stack_parm;
2769
2770 /* When an argument is passed in multiple locations, we can't make use
2771 of this information, but we can save some copying if the whole argument
2772 is passed in a single register. */
2773 else if (GET_CODE (entry_parm) == PARALLEL
2774 && data->nominal_mode != BLKmode
2775 && data->passed_mode != BLKmode)
2776 {
2777 size_t i, len = XVECLEN (entry_parm, 0);
2778
2779 for (i = 0; i < len; i++)
2780 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
2781 && REG_P (XEXP (XVECEXP (entry_parm, 0, i), 0))
2782 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
2783 == data->passed_mode)
2784 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
2785 {
2786 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
2787 break;
2788 }
2789 }
2790
2791 data->entry_parm = entry_parm;
2792 }
2793
2794 /* A subroutine of assign_parms. Reconstitute any values which were
2795 passed in multiple registers and would fit in a single register. */
2796
2797 static void
2798 assign_parm_remove_parallels (struct assign_parm_data_one *data)
2799 {
2800 rtx entry_parm = data->entry_parm;
2801
2802 /* Convert the PARALLEL to a REG of the same mode as the parallel.
2803 This can be done with register operations rather than on the
2804 stack, even if we will store the reconstituted parameter on the
2805 stack later. */
2806 if (GET_CODE (entry_parm) == PARALLEL && GET_MODE (entry_parm) != BLKmode)
2807 {
2808 rtx parmreg = gen_reg_rtx (GET_MODE (entry_parm));
2809 emit_group_store (parmreg, entry_parm, data->passed_type,
2810 GET_MODE_SIZE (GET_MODE (entry_parm)));
2811 entry_parm = parmreg;
2812 }
2813
2814 data->entry_parm = entry_parm;
2815 }
2816
2817 /* A subroutine of assign_parms. Adjust DATA->STACK_RTL such that it's
2818 always valid and properly aligned. */
2819
2820 static void
2821 assign_parm_adjust_stack_rtl (struct assign_parm_data_one *data)
2822 {
2823 rtx stack_parm = data->stack_parm;
2824
2825 /* If we can't trust the parm stack slot to be aligned enough for its
2826 ultimate type, don't use that slot after entry. We'll make another
2827 stack slot, if we need one. */
2828 if (stack_parm
2829 && ((GET_MODE_ALIGNMENT (data->nominal_mode) > MEM_ALIGN (stack_parm)
2830 && targetm.slow_unaligned_access (data->nominal_mode,
2831 MEM_ALIGN (stack_parm)))
2832 || (data->nominal_type
2833 && TYPE_ALIGN (data->nominal_type) > MEM_ALIGN (stack_parm)
2834 && MEM_ALIGN (stack_parm) < PREFERRED_STACK_BOUNDARY)))
2835 stack_parm = NULL;
2836
2837 /* If parm was passed in memory, and we need to convert it on entry,
2838 don't store it back in that same slot. */
2839 else if (data->entry_parm == stack_parm
2840 && data->nominal_mode != BLKmode
2841 && data->nominal_mode != data->passed_mode)
2842 stack_parm = NULL;
2843
2844 /* If stack protection is in effect for this function, don't leave any
2845 pointers in their passed stack slots. */
2846 else if (crtl->stack_protect_guard
2847 && (flag_stack_protect == 2
2848 || data->passed_pointer
2849 || POINTER_TYPE_P (data->nominal_type)))
2850 stack_parm = NULL;
2851
2852 data->stack_parm = stack_parm;
2853 }
2854
2855 /* A subroutine of assign_parms. Return true if the current parameter
2856 should be stored as a BLKmode in the current frame. */
2857
2858 static bool
2859 assign_parm_setup_block_p (struct assign_parm_data_one *data)
2860 {
2861 if (data->nominal_mode == BLKmode)
2862 return true;
2863 if (GET_MODE (data->entry_parm) == BLKmode)
2864 return true;
2865
2866 #ifdef BLOCK_REG_PADDING
2867 /* Only assign_parm_setup_block knows how to deal with register arguments
2868 that are padded at the least significant end. */
2869 if (REG_P (data->entry_parm)
2870 && known_lt (GET_MODE_SIZE (data->promoted_mode), UNITS_PER_WORD)
2871 && (BLOCK_REG_PADDING (data->passed_mode, data->passed_type, 1)
2872 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
2873 return true;
2874 #endif
2875
2876 return false;
2877 }
2878
2879 /* A subroutine of assign_parms. Arrange for the parameter to be
2880 present and valid in DATA->STACK_RTL. */
2881
2882 static void
2883 assign_parm_setup_block (struct assign_parm_data_all *all,
2884 tree parm, struct assign_parm_data_one *data)
2885 {
2886 rtx entry_parm = data->entry_parm;
2887 rtx stack_parm = data->stack_parm;
2888 rtx target_reg = NULL_RTX;
2889 bool in_conversion_seq = false;
2890 HOST_WIDE_INT size;
2891 HOST_WIDE_INT size_stored;
2892
2893 if (GET_CODE (entry_parm) == PARALLEL)
2894 entry_parm = emit_group_move_into_temps (entry_parm);
2895
2896 /* If we want the parameter in a pseudo, don't use a stack slot. */
2897 if (is_gimple_reg (parm) && use_register_for_decl (parm))
2898 {
2899 tree def = ssa_default_def (cfun, parm);
2900 gcc_assert (def);
2901 machine_mode mode = promote_ssa_mode (def, NULL);
2902 rtx reg = gen_reg_rtx (mode);
2903 if (GET_CODE (reg) != CONCAT)
2904 stack_parm = reg;
2905 else
2906 {
2907 target_reg = reg;
2908 /* Avoid allocating a stack slot, if there isn't one
2909 preallocated by the ABI. It might seem like we should
2910 always prefer a pseudo, but converting between
2911 floating-point and integer modes goes through the stack
2912 on various machines, so it's better to use the reserved
2913 stack slot than to risk wasting it and allocating more
2914 for the conversion. */
2915 if (stack_parm == NULL_RTX)
2916 {
2917 int save = generating_concat_p;
2918 generating_concat_p = 0;
2919 stack_parm = gen_reg_rtx (mode);
2920 generating_concat_p = save;
2921 }
2922 }
2923 data->stack_parm = NULL;
2924 }
2925
2926 size = int_size_in_bytes (data->passed_type);
2927 size_stored = CEIL_ROUND (size, UNITS_PER_WORD);
2928 if (stack_parm == 0)
2929 {
2930 HOST_WIDE_INT parm_align
2931 = (STRICT_ALIGNMENT
2932 ? MAX (DECL_ALIGN (parm), BITS_PER_WORD) : DECL_ALIGN (parm));
2933
2934 SET_DECL_ALIGN (parm, parm_align);
2935 if (DECL_ALIGN (parm) > MAX_SUPPORTED_STACK_ALIGNMENT)
2936 {
2937 rtx allocsize = gen_int_mode (size_stored, Pmode);
2938 get_dynamic_stack_size (&allocsize, 0, DECL_ALIGN (parm), NULL);
2939 stack_parm = assign_stack_local (BLKmode, UINTVAL (allocsize),
2940 MAX_SUPPORTED_STACK_ALIGNMENT);
2941 rtx addr = align_dynamic_address (XEXP (stack_parm, 0),
2942 DECL_ALIGN (parm));
2943 mark_reg_pointer (addr, DECL_ALIGN (parm));
2944 stack_parm = gen_rtx_MEM (GET_MODE (stack_parm), addr);
2945 MEM_NOTRAP_P (stack_parm) = 1;
2946 }
2947 else
2948 stack_parm = assign_stack_local (BLKmode, size_stored,
2949 DECL_ALIGN (parm));
2950 if (known_eq (GET_MODE_SIZE (GET_MODE (entry_parm)), size))
2951 PUT_MODE (stack_parm, GET_MODE (entry_parm));
2952 set_mem_attributes (stack_parm, parm, 1);
2953 }
2954
2955 /* If a BLKmode arrives in registers, copy it to a stack slot. Handle
2956 calls that pass values in multiple non-contiguous locations. */
2957 if (REG_P (entry_parm) || GET_CODE (entry_parm) == PARALLEL)
2958 {
2959 rtx mem;
2960
2961 /* Note that we will be storing an integral number of words.
2962 So we have to be careful to ensure that we allocate an
2963 integral number of words. We do this above when we call
2964 assign_stack_local if space was not allocated in the argument
2965 list. If it was, this will not work if PARM_BOUNDARY is not
2966 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2967 if it becomes a problem. Exception is when BLKmode arrives
2968 with arguments not conforming to word_mode. */
2969
2970 if (data->stack_parm == 0)
2971 ;
2972 else if (GET_CODE (entry_parm) == PARALLEL)
2973 ;
2974 else
2975 gcc_assert (!size || !(PARM_BOUNDARY % BITS_PER_WORD));
2976
2977 mem = validize_mem (copy_rtx (stack_parm));
2978
2979 /* Handle values in multiple non-contiguous locations. */
2980 if (GET_CODE (entry_parm) == PARALLEL && !MEM_P (mem))
2981 emit_group_store (mem, entry_parm, data->passed_type, size);
2982 else if (GET_CODE (entry_parm) == PARALLEL)
2983 {
2984 push_to_sequence2 (all->first_conversion_insn,
2985 all->last_conversion_insn);
2986 emit_group_store (mem, entry_parm, data->passed_type, size);
2987 all->first_conversion_insn = get_insns ();
2988 all->last_conversion_insn = get_last_insn ();
2989 end_sequence ();
2990 in_conversion_seq = true;
2991 }
2992
2993 else if (size == 0)
2994 ;
2995
2996 /* If SIZE is that of a mode no bigger than a word, just use
2997 that mode's store operation. */
2998 else if (size <= UNITS_PER_WORD)
2999 {
3000 unsigned int bits = size * BITS_PER_UNIT;
3001 machine_mode mode = int_mode_for_size (bits, 0).else_blk ();
3002
3003 if (mode != BLKmode
3004 #ifdef BLOCK_REG_PADDING
3005 && (size == UNITS_PER_WORD
3006 || (BLOCK_REG_PADDING (mode, data->passed_type, 1)
3007 != (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
3008 #endif
3009 )
3010 {
3011 rtx reg;
3012
3013 /* We are really truncating a word_mode value containing
3014 SIZE bytes into a value of mode MODE. If such an
3015 operation requires no actual instructions, we can refer
3016 to the value directly in mode MODE, otherwise we must
3017 start with the register in word_mode and explicitly
3018 convert it. */
3019 if (targetm.truly_noop_truncation (size * BITS_PER_UNIT,
3020 BITS_PER_WORD))
3021 reg = gen_rtx_REG (mode, REGNO (entry_parm));
3022 else
3023 {
3024 reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
3025 reg = convert_to_mode (mode, copy_to_reg (reg), 1);
3026 }
3027 emit_move_insn (change_address (mem, mode, 0), reg);
3028 }
3029
3030 #ifdef BLOCK_REG_PADDING
3031 /* Storing the register in memory as a full word, as
3032 move_block_from_reg below would do, and then using the
3033 MEM in a smaller mode, has the effect of shifting right
3034 if BYTES_BIG_ENDIAN. If we're bypassing memory, the
3035 shifting must be explicit. */
3036 else if (!MEM_P (mem))
3037 {
3038 rtx x;
3039
3040 /* If the assert below fails, we should have taken the
3041 mode != BLKmode path above, unless we have downward
3042 padding of smaller-than-word arguments on a machine
3043 with little-endian bytes, which would likely require
3044 additional changes to work correctly. */
3045 gcc_checking_assert (BYTES_BIG_ENDIAN
3046 && (BLOCK_REG_PADDING (mode,
3047 data->passed_type, 1)
3048 == PAD_UPWARD));
3049
3050 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
3051
3052 x = gen_rtx_REG (word_mode, REGNO (entry_parm));
3053 x = expand_shift (RSHIFT_EXPR, word_mode, x, by,
3054 NULL_RTX, 1);
3055 x = force_reg (word_mode, x);
3056 x = gen_lowpart_SUBREG (GET_MODE (mem), x);
3057
3058 emit_move_insn (mem, x);
3059 }
3060 #endif
3061
3062 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
3063 machine must be aligned to the left before storing
3064 to memory. Note that the previous test doesn't
3065 handle all cases (e.g. SIZE == 3). */
3066 else if (size != UNITS_PER_WORD
3067 #ifdef BLOCK_REG_PADDING
3068 && (BLOCK_REG_PADDING (mode, data->passed_type, 1)
3069 == PAD_DOWNWARD)
3070 #else
3071 && BYTES_BIG_ENDIAN
3072 #endif
3073 )
3074 {
3075 rtx tem, x;
3076 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
3077 rtx reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
3078
3079 x = expand_shift (LSHIFT_EXPR, word_mode, reg, by, NULL_RTX, 1);
3080 tem = change_address (mem, word_mode, 0);
3081 emit_move_insn (tem, x);
3082 }
3083 else
3084 move_block_from_reg (REGNO (entry_parm), mem,
3085 size_stored / UNITS_PER_WORD);
3086 }
3087 else if (!MEM_P (mem))
3088 {
3089 gcc_checking_assert (size > UNITS_PER_WORD);
3090 #ifdef BLOCK_REG_PADDING
3091 gcc_checking_assert (BLOCK_REG_PADDING (GET_MODE (mem),
3092 data->passed_type, 0)
3093 == PAD_UPWARD);
3094 #endif
3095 emit_move_insn (mem, entry_parm);
3096 }
3097 else
3098 move_block_from_reg (REGNO (entry_parm), mem,
3099 size_stored / UNITS_PER_WORD);
3100 }
3101 else if (data->stack_parm == 0)
3102 {
3103 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3104 emit_block_move (stack_parm, data->entry_parm, GEN_INT (size),
3105 BLOCK_OP_NORMAL);
3106 all->first_conversion_insn = get_insns ();
3107 all->last_conversion_insn = get_last_insn ();
3108 end_sequence ();
3109 in_conversion_seq = true;
3110 }
3111
3112 if (target_reg)
3113 {
3114 if (!in_conversion_seq)
3115 emit_move_insn (target_reg, stack_parm);
3116 else
3117 {
3118 push_to_sequence2 (all->first_conversion_insn,
3119 all->last_conversion_insn);
3120 emit_move_insn (target_reg, stack_parm);
3121 all->first_conversion_insn = get_insns ();
3122 all->last_conversion_insn = get_last_insn ();
3123 end_sequence ();
3124 }
3125 stack_parm = target_reg;
3126 }
3127
3128 data->stack_parm = stack_parm;
3129 set_parm_rtl (parm, stack_parm);
3130 }
3131
3132 /* A subroutine of assign_parms. Allocate a pseudo to hold the current
3133 parameter. Get it there. Perform all ABI specified conversions. */
3134
3135 static void
3136 assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm,
3137 struct assign_parm_data_one *data)
3138 {
3139 rtx parmreg, validated_mem;
3140 rtx equiv_stack_parm;
3141 machine_mode promoted_nominal_mode;
3142 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (parm));
3143 bool did_conversion = false;
3144 bool need_conversion, moved;
3145 enum insn_code icode;
3146 rtx rtl;
3147
3148 /* Store the parm in a pseudoregister during the function, but we may
3149 need to do it in a wider mode. Using 2 here makes the result
3150 consistent with promote_decl_mode and thus expand_expr_real_1. */
3151 promoted_nominal_mode
3152 = promote_function_mode (data->nominal_type, data->nominal_mode, &unsignedp,
3153 TREE_TYPE (current_function_decl), 2);
3154
3155 parmreg = gen_reg_rtx (promoted_nominal_mode);
3156 if (!DECL_ARTIFICIAL (parm))
3157 mark_user_reg (parmreg);
3158
3159 /* If this was an item that we received a pointer to,
3160 set rtl appropriately. */
3161 if (data->passed_pointer)
3162 {
3163 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data->passed_type)), parmreg);
3164 set_mem_attributes (rtl, parm, 1);
3165 }
3166 else
3167 rtl = parmreg;
3168
3169 assign_parm_remove_parallels (data);
3170
3171 /* Copy the value into the register, thus bridging between
3172 assign_parm_find_data_types and expand_expr_real_1. */
3173
3174 equiv_stack_parm = data->stack_parm;
3175 validated_mem = validize_mem (copy_rtx (data->entry_parm));
3176
3177 need_conversion = (data->nominal_mode != data->passed_mode
3178 || promoted_nominal_mode != data->promoted_mode);
3179 moved = false;
3180
3181 if (need_conversion
3182 && GET_MODE_CLASS (data->nominal_mode) == MODE_INT
3183 && data->nominal_mode == data->passed_mode
3184 && data->nominal_mode == GET_MODE (data->entry_parm))
3185 {
3186 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
3187 mode, by the caller. We now have to convert it to
3188 NOMINAL_MODE, if different. However, PARMREG may be in
3189 a different mode than NOMINAL_MODE if it is being stored
3190 promoted.
3191
3192 If ENTRY_PARM is a hard register, it might be in a register
3193 not valid for operating in its mode (e.g., an odd-numbered
3194 register for a DFmode). In that case, moves are the only
3195 thing valid, so we can't do a convert from there. This
3196 occurs when the calling sequence allow such misaligned
3197 usages.
3198
3199 In addition, the conversion may involve a call, which could
3200 clobber parameters which haven't been copied to pseudo
3201 registers yet.
3202
3203 First, we try to emit an insn which performs the necessary
3204 conversion. We verify that this insn does not clobber any
3205 hard registers. */
3206
3207 rtx op0, op1;
3208
3209 icode = can_extend_p (promoted_nominal_mode, data->passed_mode,
3210 unsignedp);
3211
3212 op0 = parmreg;
3213 op1 = validated_mem;
3214 if (icode != CODE_FOR_nothing
3215 && insn_operand_matches (icode, 0, op0)
3216 && insn_operand_matches (icode, 1, op1))
3217 {
3218 enum rtx_code code = unsignedp ? ZERO_EXTEND : SIGN_EXTEND;
3219 rtx_insn *insn, *insns;
3220 rtx t = op1;
3221 HARD_REG_SET hardregs;
3222
3223 start_sequence ();
3224 /* If op1 is a hard register that is likely spilled, first
3225 force it into a pseudo, otherwise combiner might extend
3226 its lifetime too much. */
3227 if (GET_CODE (t) == SUBREG)
3228 t = SUBREG_REG (t);
3229 if (REG_P (t)
3230 && HARD_REGISTER_P (t)
3231 && ! TEST_HARD_REG_BIT (fixed_reg_set, REGNO (t))
3232 && targetm.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (t))))
3233 {
3234 t = gen_reg_rtx (GET_MODE (op1));
3235 emit_move_insn (t, op1);
3236 }
3237 else
3238 t = op1;
3239 rtx_insn *pat = gen_extend_insn (op0, t, promoted_nominal_mode,
3240 data->passed_mode, unsignedp);
3241 emit_insn (pat);
3242 insns = get_insns ();
3243
3244 moved = true;
3245 CLEAR_HARD_REG_SET (hardregs);
3246 for (insn = insns; insn && moved; insn = NEXT_INSN (insn))
3247 {
3248 if (INSN_P (insn))
3249 note_stores (PATTERN (insn), record_hard_reg_sets,
3250 &hardregs);
3251 if (!hard_reg_set_empty_p (hardregs))
3252 moved = false;
3253 }
3254
3255 end_sequence ();
3256
3257 if (moved)
3258 {
3259 emit_insn (insns);
3260 if (equiv_stack_parm != NULL_RTX)
3261 equiv_stack_parm = gen_rtx_fmt_e (code, GET_MODE (parmreg),
3262 equiv_stack_parm);
3263 }
3264 }
3265 }
3266
3267 if (moved)
3268 /* Nothing to do. */
3269 ;
3270 else if (need_conversion)
3271 {
3272 /* We did not have an insn to convert directly, or the sequence
3273 generated appeared unsafe. We must first copy the parm to a
3274 pseudo reg, and save the conversion until after all
3275 parameters have been moved. */
3276
3277 int save_tree_used;
3278 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
3279
3280 emit_move_insn (tempreg, validated_mem);
3281
3282 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3283 tempreg = convert_to_mode (data->nominal_mode, tempreg, unsignedp);
3284
3285 if (partial_subreg_p (tempreg)
3286 && GET_MODE (tempreg) == data->nominal_mode
3287 && REG_P (SUBREG_REG (tempreg))
3288 && data->nominal_mode == data->passed_mode
3289 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (data->entry_parm))
3290 {
3291 /* The argument is already sign/zero extended, so note it
3292 into the subreg. */
3293 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
3294 SUBREG_PROMOTED_SET (tempreg, unsignedp);
3295 }
3296
3297 /* TREE_USED gets set erroneously during expand_assignment. */
3298 save_tree_used = TREE_USED (parm);
3299 SET_DECL_RTL (parm, rtl);
3300 expand_assignment (parm, make_tree (data->nominal_type, tempreg), false);
3301 SET_DECL_RTL (parm, NULL_RTX);
3302 TREE_USED (parm) = save_tree_used;
3303 all->first_conversion_insn = get_insns ();
3304 all->last_conversion_insn = get_last_insn ();
3305 end_sequence ();
3306
3307 did_conversion = true;
3308 }
3309 else if (MEM_P (data->entry_parm)
3310 && GET_MODE_ALIGNMENT (promoted_nominal_mode)
3311 > MEM_ALIGN (data->entry_parm)
3312 && (((icode = optab_handler (movmisalign_optab,
3313 promoted_nominal_mode))
3314 != CODE_FOR_nothing)
3315 || targetm.slow_unaligned_access (promoted_nominal_mode,
3316 MEM_ALIGN (data->entry_parm))))
3317 {
3318 if (icode != CODE_FOR_nothing)
3319 emit_insn (GEN_FCN (icode) (parmreg, validated_mem));
3320 else
3321 rtl = parmreg = extract_bit_field (validated_mem,
3322 GET_MODE_BITSIZE (promoted_nominal_mode), 0,
3323 unsignedp, parmreg,
3324 promoted_nominal_mode, VOIDmode, false, NULL);
3325 }
3326 else
3327 emit_move_insn (parmreg, validated_mem);
3328
3329 /* If we were passed a pointer but the actual value can safely live
3330 in a register, retrieve it and use it directly. */
3331 if (data->passed_pointer && TYPE_MODE (TREE_TYPE (parm)) != BLKmode)
3332 {
3333 /* We can't use nominal_mode, because it will have been set to
3334 Pmode above. We must use the actual mode of the parm. */
3335 if (use_register_for_decl (parm))
3336 {
3337 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
3338 mark_user_reg (parmreg);
3339 }
3340 else
3341 {
3342 int align = STACK_SLOT_ALIGNMENT (TREE_TYPE (parm),
3343 TYPE_MODE (TREE_TYPE (parm)),
3344 TYPE_ALIGN (TREE_TYPE (parm)));
3345 parmreg
3346 = assign_stack_local (TYPE_MODE (TREE_TYPE (parm)),
3347 GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (parm))),
3348 align);
3349 set_mem_attributes (parmreg, parm, 1);
3350 }
3351
3352 /* We need to preserve an address based on VIRTUAL_STACK_VARS_REGNUM for
3353 the debug info in case it is not legitimate. */
3354 if (GET_MODE (parmreg) != GET_MODE (rtl))
3355 {
3356 rtx tempreg = gen_reg_rtx (GET_MODE (rtl));
3357 int unsigned_p = TYPE_UNSIGNED (TREE_TYPE (parm));
3358
3359 push_to_sequence2 (all->first_conversion_insn,
3360 all->last_conversion_insn);
3361 emit_move_insn (tempreg, rtl);
3362 tempreg = convert_to_mode (GET_MODE (parmreg), tempreg, unsigned_p);
3363 emit_move_insn (MEM_P (parmreg) ? copy_rtx (parmreg) : parmreg,
3364 tempreg);
3365 all->first_conversion_insn = get_insns ();
3366 all->last_conversion_insn = get_last_insn ();
3367 end_sequence ();
3368
3369 did_conversion = true;
3370 }
3371 else
3372 emit_move_insn (MEM_P (parmreg) ? copy_rtx (parmreg) : parmreg, rtl);
3373
3374 rtl = parmreg;
3375
3376 /* STACK_PARM is the pointer, not the parm, and PARMREG is
3377 now the parm. */
3378 data->stack_parm = NULL;
3379 }
3380
3381 set_parm_rtl (parm, rtl);
3382
3383 /* Mark the register as eliminable if we did no conversion and it was
3384 copied from memory at a fixed offset, and the arg pointer was not
3385 copied to a pseudo-reg. If the arg pointer is a pseudo reg or the
3386 offset formed an invalid address, such memory-equivalences as we
3387 make here would screw up life analysis for it. */
3388 if (data->nominal_mode == data->passed_mode
3389 && !did_conversion
3390 && data->stack_parm != 0
3391 && MEM_P (data->stack_parm)
3392 && data->locate.offset.var == 0
3393 && reg_mentioned_p (virtual_incoming_args_rtx,
3394 XEXP (data->stack_parm, 0)))
3395 {
3396 rtx_insn *linsn = get_last_insn ();
3397 rtx_insn *sinsn;
3398 rtx set;
3399
3400 /* Mark complex types separately. */
3401 if (GET_CODE (parmreg) == CONCAT)
3402 {
3403 scalar_mode submode = GET_MODE_INNER (GET_MODE (parmreg));
3404 int regnor = REGNO (XEXP (parmreg, 0));
3405 int regnoi = REGNO (XEXP (parmreg, 1));
3406 rtx stackr = adjust_address_nv (data->stack_parm, submode, 0);
3407 rtx stacki = adjust_address_nv (data->stack_parm, submode,
3408 GET_MODE_SIZE (submode));
3409
3410 /* Scan backwards for the set of the real and
3411 imaginary parts. */
3412 for (sinsn = linsn; sinsn != 0;
3413 sinsn = prev_nonnote_insn (sinsn))
3414 {
3415 set = single_set (sinsn);
3416 if (set == 0)
3417 continue;
3418
3419 if (SET_DEST (set) == regno_reg_rtx [regnoi])
3420 set_unique_reg_note (sinsn, REG_EQUIV, stacki);
3421 else if (SET_DEST (set) == regno_reg_rtx [regnor])
3422 set_unique_reg_note (sinsn, REG_EQUIV, stackr);
3423 }
3424 }
3425 else
3426 set_dst_reg_note (linsn, REG_EQUIV, equiv_stack_parm, parmreg);
3427 }
3428
3429 /* For pointer data type, suggest pointer register. */
3430 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3431 mark_reg_pointer (parmreg,
3432 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
3433 }
3434
3435 /* A subroutine of assign_parms. Allocate stack space to hold the current
3436 parameter. Get it there. Perform all ABI specified conversions. */
3437
3438 static void
3439 assign_parm_setup_stack (struct assign_parm_data_all *all, tree parm,
3440 struct assign_parm_data_one *data)
3441 {
3442 /* Value must be stored in the stack slot STACK_PARM during function
3443 execution. */
3444 bool to_conversion = false;
3445
3446 assign_parm_remove_parallels (data);
3447
3448 if (data->promoted_mode != data->nominal_mode)
3449 {
3450 /* Conversion is required. */
3451 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
3452
3453 emit_move_insn (tempreg, validize_mem (copy_rtx (data->entry_parm)));
3454
3455 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3456 to_conversion = true;
3457
3458 data->entry_parm = convert_to_mode (data->nominal_mode, tempreg,
3459 TYPE_UNSIGNED (TREE_TYPE (parm)));
3460
3461 if (data->stack_parm)
3462 {
3463 poly_int64 offset
3464 = subreg_lowpart_offset (data->nominal_mode,
3465 GET_MODE (data->stack_parm));
3466 /* ??? This may need a big-endian conversion on sparc64. */
3467 data->stack_parm
3468 = adjust_address (data->stack_parm, data->nominal_mode, 0);
3469 if (maybe_ne (offset, 0) && MEM_OFFSET_KNOWN_P (data->stack_parm))
3470 set_mem_offset (data->stack_parm,
3471 MEM_OFFSET (data->stack_parm) + offset);
3472 }
3473 }
3474
3475 if (data->entry_parm != data->stack_parm)
3476 {
3477 rtx src, dest;
3478
3479 if (data->stack_parm == 0)
3480 {
3481 int align = STACK_SLOT_ALIGNMENT (data->passed_type,
3482 GET_MODE (data->entry_parm),
3483 TYPE_ALIGN (data->passed_type));
3484 data->stack_parm
3485 = assign_stack_local (GET_MODE (data->entry_parm),
3486 GET_MODE_SIZE (GET_MODE (data->entry_parm)),
3487 align);
3488 set_mem_attributes (data->stack_parm, parm, 1);
3489 }
3490
3491 dest = validize_mem (copy_rtx (data->stack_parm));
3492 src = validize_mem (copy_rtx (data->entry_parm));
3493
3494 if (MEM_P (src))
3495 {
3496 /* Use a block move to handle potentially misaligned entry_parm. */
3497 if (!to_conversion)
3498 push_to_sequence2 (all->first_conversion_insn,
3499 all->last_conversion_insn);
3500 to_conversion = true;
3501
3502 emit_block_move (dest, src,
3503 GEN_INT (int_size_in_bytes (data->passed_type)),
3504 BLOCK_OP_NORMAL);
3505 }
3506 else
3507 {
3508 if (!REG_P (src))
3509 src = force_reg (GET_MODE (src), src);
3510 emit_move_insn (dest, src);
3511 }
3512 }
3513
3514 if (to_conversion)
3515 {
3516 all->first_conversion_insn = get_insns ();
3517 all->last_conversion_insn = get_last_insn ();
3518 end_sequence ();
3519 }
3520
3521 set_parm_rtl (parm, data->stack_parm);
3522 }
3523
3524 /* A subroutine of assign_parms. If the ABI splits complex arguments, then
3525 undo the frobbing that we did in assign_parms_augmented_arg_list. */
3526
3527 static void
3528 assign_parms_unsplit_complex (struct assign_parm_data_all *all,
3529 vec<tree> fnargs)
3530 {
3531 tree parm;
3532 tree orig_fnargs = all->orig_fnargs;
3533 unsigned i = 0;
3534
3535 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm), ++i)
3536 {
3537 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
3538 && targetm.calls.split_complex_arg (TREE_TYPE (parm)))
3539 {
3540 rtx tmp, real, imag;
3541 scalar_mode inner = GET_MODE_INNER (DECL_MODE (parm));
3542
3543 real = DECL_RTL (fnargs[i]);
3544 imag = DECL_RTL (fnargs[i + 1]);
3545 if (inner != GET_MODE (real))
3546 {
3547 real = gen_lowpart_SUBREG (inner, real);
3548 imag = gen_lowpart_SUBREG (inner, imag);
3549 }
3550
3551 if (TREE_ADDRESSABLE (parm))
3552 {
3553 rtx rmem, imem;
3554 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (parm));
3555 int align = STACK_SLOT_ALIGNMENT (TREE_TYPE (parm),
3556 DECL_MODE (parm),
3557 TYPE_ALIGN (TREE_TYPE (parm)));
3558
3559 /* split_complex_arg put the real and imag parts in
3560 pseudos. Move them to memory. */
3561 tmp = assign_stack_local (DECL_MODE (parm), size, align);
3562 set_mem_attributes (tmp, parm, 1);
3563 rmem = adjust_address_nv (tmp, inner, 0);
3564 imem = adjust_address_nv (tmp, inner, GET_MODE_SIZE (inner));
3565 push_to_sequence2 (all->first_conversion_insn,
3566 all->last_conversion_insn);
3567 emit_move_insn (rmem, real);
3568 emit_move_insn (imem, imag);
3569 all->first_conversion_insn = get_insns ();
3570 all->last_conversion_insn = get_last_insn ();
3571 end_sequence ();
3572 }
3573 else
3574 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
3575 set_parm_rtl (parm, tmp);
3576
3577 real = DECL_INCOMING_RTL (fnargs[i]);
3578 imag = DECL_INCOMING_RTL (fnargs[i + 1]);
3579 if (inner != GET_MODE (real))
3580 {
3581 real = gen_lowpart_SUBREG (inner, real);
3582 imag = gen_lowpart_SUBREG (inner, imag);
3583 }
3584 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
3585 set_decl_incoming_rtl (parm, tmp, false);
3586 i++;
3587 }
3588 }
3589 }
3590
3591 /* Assign RTL expressions to the function's parameters. This may involve
3592 copying them into registers and using those registers as the DECL_RTL. */
3593
3594 static void
3595 assign_parms (tree fndecl)
3596 {
3597 struct assign_parm_data_all all;
3598 tree parm;
3599 vec<tree> fnargs;
3600 unsigned i;
3601
3602 crtl->args.internal_arg_pointer
3603 = targetm.calls.internal_arg_pointer ();
3604
3605 assign_parms_initialize_all (&all);
3606 fnargs = assign_parms_augmented_arg_list (&all);
3607
3608 FOR_EACH_VEC_ELT (fnargs, i, parm)
3609 {
3610 struct assign_parm_data_one data;
3611
3612 /* Extract the type of PARM; adjust it according to ABI. */
3613 assign_parm_find_data_types (&all, parm, &data);
3614
3615 /* Early out for errors and void parameters. */
3616 if (data.passed_mode == VOIDmode)
3617 {
3618 SET_DECL_RTL (parm, const0_rtx);
3619 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
3620 continue;
3621 }
3622
3623 /* Estimate stack alignment from parameter alignment. */
3624 if (SUPPORTS_STACK_ALIGNMENT)
3625 {
3626 unsigned int align
3627 = targetm.calls.function_arg_boundary (data.promoted_mode,
3628 data.passed_type);
3629 align = MINIMUM_ALIGNMENT (data.passed_type, data.promoted_mode,
3630 align);
3631 if (TYPE_ALIGN (data.nominal_type) > align)
3632 align = MINIMUM_ALIGNMENT (data.nominal_type,
3633 TYPE_MODE (data.nominal_type),
3634 TYPE_ALIGN (data.nominal_type));
3635 if (crtl->stack_alignment_estimated < align)
3636 {
3637 gcc_assert (!crtl->stack_realign_processed);
3638 crtl->stack_alignment_estimated = align;
3639 }
3640 }
3641
3642 /* Find out where the parameter arrives in this function. */
3643 assign_parm_find_entry_rtl (&all, &data);
3644
3645 /* Find out where stack space for this parameter might be. */
3646 if (assign_parm_is_stack_parm (&all, &data))
3647 {
3648 assign_parm_find_stack_rtl (parm, &data);
3649 assign_parm_adjust_entry_rtl (&data);
3650 }
3651 /* Record permanently how this parm was passed. */
3652 if (data.passed_pointer)
3653 {
3654 rtx incoming_rtl
3655 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data.passed_type)),
3656 data.entry_parm);
3657 set_decl_incoming_rtl (parm, incoming_rtl, true);
3658 }
3659 else
3660 set_decl_incoming_rtl (parm, data.entry_parm, false);
3661
3662 assign_parm_adjust_stack_rtl (&data);
3663
3664 if (assign_parm_setup_block_p (&data))
3665 assign_parm_setup_block (&all, parm, &data);
3666 else if (data.passed_pointer || use_register_for_decl (parm))
3667 assign_parm_setup_reg (&all, parm, &data);
3668 else
3669 assign_parm_setup_stack (&all, parm, &data);
3670
3671 if (cfun->stdarg && !DECL_CHAIN (parm))
3672 assign_parms_setup_varargs (&all, &data, false);
3673
3674 /* Update info on where next arg arrives in registers. */
3675 targetm.calls.function_arg_advance (all.args_so_far, data.promoted_mode,
3676 data.passed_type, data.named_arg);
3677 }
3678
3679 if (targetm.calls.split_complex_arg)
3680 assign_parms_unsplit_complex (&all, fnargs);
3681
3682 fnargs.release ();
3683
3684 /* Output all parameter conversion instructions (possibly including calls)
3685 now that all parameters have been copied out of hard registers. */
3686 emit_insn (all.first_conversion_insn);
3687
3688 /* Estimate reload stack alignment from scalar return mode. */
3689 if (SUPPORTS_STACK_ALIGNMENT)
3690 {
3691 if (DECL_RESULT (fndecl))
3692 {
3693 tree type = TREE_TYPE (DECL_RESULT (fndecl));
3694 machine_mode mode = TYPE_MODE (type);
3695
3696 if (mode != BLKmode
3697 && mode != VOIDmode
3698 && !AGGREGATE_TYPE_P (type))
3699 {
3700 unsigned int align = GET_MODE_ALIGNMENT (mode);
3701 if (crtl->stack_alignment_estimated < align)
3702 {
3703 gcc_assert (!crtl->stack_realign_processed);
3704 crtl->stack_alignment_estimated = align;
3705 }
3706 }
3707 }
3708 }
3709
3710 /* If we are receiving a struct value address as the first argument, set up
3711 the RTL for the function result. As this might require code to convert
3712 the transmitted address to Pmode, we do this here to ensure that possible
3713 preliminary conversions of the address have been emitted already. */
3714 if (all.function_result_decl)
3715 {
3716 tree result = DECL_RESULT (current_function_decl);
3717 rtx addr = DECL_RTL (all.function_result_decl);
3718 rtx x;
3719
3720 if (DECL_BY_REFERENCE (result))
3721 {
3722 SET_DECL_VALUE_EXPR (result, all.function_result_decl);
3723 x = addr;
3724 }
3725 else
3726 {
3727 SET_DECL_VALUE_EXPR (result,
3728 build1 (INDIRECT_REF, TREE_TYPE (result),
3729 all.function_result_decl));
3730 addr = convert_memory_address (Pmode, addr);
3731 x = gen_rtx_MEM (DECL_MODE (result), addr);
3732 set_mem_attributes (x, result, 1);
3733 }
3734
3735 DECL_HAS_VALUE_EXPR_P (result) = 1;
3736
3737 set_parm_rtl (result, x);
3738 }
3739
3740 /* We have aligned all the args, so add space for the pretend args. */
3741 crtl->args.pretend_args_size = all.pretend_args_size;
3742 all.stack_args_size.constant += all.extra_pretend_bytes;
3743 crtl->args.size = all.stack_args_size.constant;
3744
3745 /* Adjust function incoming argument size for alignment and
3746 minimum length. */
3747
3748 crtl->args.size = upper_bound (crtl->args.size, all.reg_parm_stack_space);
3749 crtl->args.size = aligned_upper_bound (crtl->args.size,
3750 PARM_BOUNDARY / BITS_PER_UNIT);
3751
3752 if (ARGS_GROW_DOWNWARD)
3753 {
3754 crtl->args.arg_offset_rtx
3755 = (all.stack_args_size.var == 0
3756 ? gen_int_mode (-all.stack_args_size.constant, Pmode)
3757 : expand_expr (size_diffop (all.stack_args_size.var,
3758 size_int (-all.stack_args_size.constant)),
3759 NULL_RTX, VOIDmode, EXPAND_NORMAL));
3760 }
3761 else
3762 crtl->args.arg_offset_rtx = ARGS_SIZE_RTX (all.stack_args_size);
3763
3764 /* See how many bytes, if any, of its args a function should try to pop
3765 on return. */
3766
3767 crtl->args.pops_args = targetm.calls.return_pops_args (fndecl,
3768 TREE_TYPE (fndecl),
3769 crtl->args.size);
3770
3771 /* For stdarg.h function, save info about
3772 regs and stack space used by the named args. */
3773
3774 crtl->args.info = all.args_so_far_v;
3775
3776 /* Set the rtx used for the function return value. Put this in its
3777 own variable so any optimizers that need this information don't have
3778 to include tree.h. Do this here so it gets done when an inlined
3779 function gets output. */
3780
3781 crtl->return_rtx
3782 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
3783 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
3784
3785 /* If scalar return value was computed in a pseudo-reg, or was a named
3786 return value that got dumped to the stack, copy that to the hard
3787 return register. */
3788 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
3789 {
3790 tree decl_result = DECL_RESULT (fndecl);
3791 rtx decl_rtl = DECL_RTL (decl_result);
3792
3793 if (REG_P (decl_rtl)
3794 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
3795 : DECL_REGISTER (decl_result))
3796 {
3797 rtx real_decl_rtl;
3798
3799 real_decl_rtl = targetm.calls.function_value (TREE_TYPE (decl_result),
3800 fndecl, true);
3801 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
3802 /* The delay slot scheduler assumes that crtl->return_rtx
3803 holds the hard register containing the return value, not a
3804 temporary pseudo. */
3805 crtl->return_rtx = real_decl_rtl;
3806 }
3807 }
3808 }
3809
3810 /* A subroutine of gimplify_parameters, invoked via walk_tree.
3811 For all seen types, gimplify their sizes. */
3812
3813 static tree
3814 gimplify_parm_type (tree *tp, int *walk_subtrees, void *data)
3815 {
3816 tree t = *tp;
3817
3818 *walk_subtrees = 0;
3819 if (TYPE_P (t))
3820 {
3821 if (POINTER_TYPE_P (t))
3822 *walk_subtrees = 1;
3823 else if (TYPE_SIZE (t) && !TREE_CONSTANT (TYPE_SIZE (t))
3824 && !TYPE_SIZES_GIMPLIFIED (t))
3825 {
3826 gimplify_type_sizes (t, (gimple_seq *) data);
3827 *walk_subtrees = 1;
3828 }
3829 }
3830
3831 return NULL;
3832 }
3833
3834 /* Gimplify the parameter list for current_function_decl. This involves
3835 evaluating SAVE_EXPRs of variable sized parameters and generating code
3836 to implement callee-copies reference parameters. Returns a sequence of
3837 statements to add to the beginning of the function. */
3838
3839 gimple_seq
3840 gimplify_parameters (gimple_seq *cleanup)
3841 {
3842 struct assign_parm_data_all all;
3843 tree parm;
3844 gimple_seq stmts = NULL;
3845 vec<tree> fnargs;
3846 unsigned i;
3847
3848 assign_parms_initialize_all (&all);
3849 fnargs = assign_parms_augmented_arg_list (&all);
3850
3851 FOR_EACH_VEC_ELT (fnargs, i, parm)
3852 {
3853 struct assign_parm_data_one data;
3854
3855 /* Extract the type of PARM; adjust it according to ABI. */
3856 assign_parm_find_data_types (&all, parm, &data);
3857
3858 /* Early out for errors and void parameters. */
3859 if (data.passed_mode == VOIDmode || DECL_SIZE (parm) == NULL)
3860 continue;
3861
3862 /* Update info on where next arg arrives in registers. */
3863 targetm.calls.function_arg_advance (all.args_so_far, data.promoted_mode,
3864 data.passed_type, data.named_arg);
3865
3866 /* ??? Once upon a time variable_size stuffed parameter list
3867 SAVE_EXPRs (amongst others) onto a pending sizes list. This
3868 turned out to be less than manageable in the gimple world.
3869 Now we have to hunt them down ourselves. */
3870 walk_tree_without_duplicates (&data.passed_type,
3871 gimplify_parm_type, &stmts);
3872
3873 if (TREE_CODE (DECL_SIZE_UNIT (parm)) != INTEGER_CST)
3874 {
3875 gimplify_one_sizepos (&DECL_SIZE (parm), &stmts);
3876 gimplify_one_sizepos (&DECL_SIZE_UNIT (parm), &stmts);
3877 }
3878
3879 if (data.passed_pointer)
3880 {
3881 tree type = TREE_TYPE (data.passed_type);
3882 if (reference_callee_copied (&all.args_so_far_v, TYPE_MODE (type),
3883 type, data.named_arg))
3884 {
3885 tree local, t;
3886
3887 /* For constant-sized objects, this is trivial; for
3888 variable-sized objects, we have to play games. */
3889 if (TREE_CODE (DECL_SIZE_UNIT (parm)) == INTEGER_CST
3890 && !(flag_stack_check == GENERIC_STACK_CHECK
3891 && compare_tree_int (DECL_SIZE_UNIT (parm),
3892 STACK_CHECK_MAX_VAR_SIZE) > 0))
3893 {
3894 local = create_tmp_var (type, get_name (parm));
3895 DECL_IGNORED_P (local) = 0;
3896 /* If PARM was addressable, move that flag over
3897 to the local copy, as its address will be taken,
3898 not the PARMs. Keep the parms address taken
3899 as we'll query that flag during gimplification. */
3900 if (TREE_ADDRESSABLE (parm))
3901 TREE_ADDRESSABLE (local) = 1;
3902 else if (TREE_CODE (type) == COMPLEX_TYPE
3903 || TREE_CODE (type) == VECTOR_TYPE)
3904 DECL_GIMPLE_REG_P (local) = 1;
3905
3906 if (!is_gimple_reg (local)
3907 && flag_stack_reuse != SR_NONE)
3908 {
3909 tree clobber = build_constructor (type, NULL);
3910 gimple *clobber_stmt;
3911 TREE_THIS_VOLATILE (clobber) = 1;
3912 clobber_stmt = gimple_build_assign (local, clobber);
3913 gimple_seq_add_stmt (cleanup, clobber_stmt);
3914 }
3915 }
3916 else
3917 {
3918 tree ptr_type, addr;
3919
3920 ptr_type = build_pointer_type (type);
3921 addr = create_tmp_reg (ptr_type, get_name (parm));
3922 DECL_IGNORED_P (addr) = 0;
3923 local = build_fold_indirect_ref (addr);
3924
3925 t = build_alloca_call_expr (DECL_SIZE_UNIT (parm),
3926 DECL_ALIGN (parm),
3927 max_int_size_in_bytes (type));
3928 /* The call has been built for a variable-sized object. */
3929 CALL_ALLOCA_FOR_VAR_P (t) = 1;
3930 t = fold_convert (ptr_type, t);
3931 t = build2 (MODIFY_EXPR, TREE_TYPE (addr), addr, t);
3932 gimplify_and_add (t, &stmts);
3933 }
3934
3935 gimplify_assign (local, parm, &stmts);
3936
3937 SET_DECL_VALUE_EXPR (parm, local);
3938 DECL_HAS_VALUE_EXPR_P (parm) = 1;
3939 }
3940 }
3941 }
3942
3943 fnargs.release ();
3944
3945 return stmts;
3946 }
3947 \f
3948 /* Compute the size and offset from the start of the stacked arguments for a
3949 parm passed in mode PASSED_MODE and with type TYPE.
3950
3951 INITIAL_OFFSET_PTR points to the current offset into the stacked
3952 arguments.
3953
3954 The starting offset and size for this parm are returned in
3955 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
3956 nonzero, the offset is that of stack slot, which is returned in
3957 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
3958 padding required from the initial offset ptr to the stack slot.
3959
3960 IN_REGS is nonzero if the argument will be passed in registers. It will
3961 never be set if REG_PARM_STACK_SPACE is not defined.
3962
3963 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
3964 for arguments which are passed in registers.
3965
3966 FNDECL is the function in which the argument was defined.
3967
3968 There are two types of rounding that are done. The first, controlled by
3969 TARGET_FUNCTION_ARG_BOUNDARY, forces the offset from the start of the
3970 argument list to be aligned to the specific boundary (in bits). This
3971 rounding affects the initial and starting offsets, but not the argument
3972 size.
3973
3974 The second, controlled by TARGET_FUNCTION_ARG_PADDING and PARM_BOUNDARY,
3975 optionally rounds the size of the parm to PARM_BOUNDARY. The
3976 initial offset is not affected by this rounding, while the size always
3977 is and the starting offset may be. */
3978
3979 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
3980 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
3981 callers pass in the total size of args so far as
3982 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
3983
3984 void
3985 locate_and_pad_parm (machine_mode passed_mode, tree type, int in_regs,
3986 int reg_parm_stack_space, int partial,
3987 tree fndecl ATTRIBUTE_UNUSED,
3988 struct args_size *initial_offset_ptr,
3989 struct locate_and_pad_arg_data *locate)
3990 {
3991 tree sizetree;
3992 pad_direction where_pad;
3993 unsigned int boundary, round_boundary;
3994 int part_size_in_regs;
3995
3996 /* If we have found a stack parm before we reach the end of the
3997 area reserved for registers, skip that area. */
3998 if (! in_regs)
3999 {
4000 if (reg_parm_stack_space > 0)
4001 {
4002 if (initial_offset_ptr->var
4003 || !ordered_p (initial_offset_ptr->constant,
4004 reg_parm_stack_space))
4005 {
4006 initial_offset_ptr->var
4007 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
4008 ssize_int (reg_parm_stack_space));
4009 initial_offset_ptr->constant = 0;
4010 }
4011 else
4012 initial_offset_ptr->constant
4013 = ordered_max (initial_offset_ptr->constant,
4014 reg_parm_stack_space);
4015 }
4016 }
4017
4018 part_size_in_regs = (reg_parm_stack_space == 0 ? partial : 0);
4019
4020 sizetree = (type
4021 ? arg_size_in_bytes (type)
4022 : size_int (GET_MODE_SIZE (passed_mode)));
4023 where_pad = targetm.calls.function_arg_padding (passed_mode, type);
4024 boundary = targetm.calls.function_arg_boundary (passed_mode, type);
4025 round_boundary = targetm.calls.function_arg_round_boundary (passed_mode,
4026 type);
4027 locate->where_pad = where_pad;
4028
4029 /* Alignment can't exceed MAX_SUPPORTED_STACK_ALIGNMENT. */
4030 if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
4031 boundary = MAX_SUPPORTED_STACK_ALIGNMENT;
4032
4033 locate->boundary = boundary;
4034
4035 if (SUPPORTS_STACK_ALIGNMENT)
4036 {
4037 /* stack_alignment_estimated can't change after stack has been
4038 realigned. */
4039 if (crtl->stack_alignment_estimated < boundary)
4040 {
4041 if (!crtl->stack_realign_processed)
4042 crtl->stack_alignment_estimated = boundary;
4043 else
4044 {
4045 /* If stack is realigned and stack alignment value
4046 hasn't been finalized, it is OK not to increase
4047 stack_alignment_estimated. The bigger alignment
4048 requirement is recorded in stack_alignment_needed
4049 below. */
4050 gcc_assert (!crtl->stack_realign_finalized
4051 && crtl->stack_realign_needed);
4052 }
4053 }
4054 }
4055
4056 if (ARGS_GROW_DOWNWARD)
4057 {
4058 locate->slot_offset.constant = -initial_offset_ptr->constant;
4059 if (initial_offset_ptr->var)
4060 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
4061 initial_offset_ptr->var);
4062
4063 {
4064 tree s2 = sizetree;
4065 if (where_pad != PAD_NONE
4066 && (!tree_fits_uhwi_p (sizetree)
4067 || (tree_to_uhwi (sizetree) * BITS_PER_UNIT) % round_boundary))
4068 s2 = round_up (s2, round_boundary / BITS_PER_UNIT);
4069 SUB_PARM_SIZE (locate->slot_offset, s2);
4070 }
4071
4072 locate->slot_offset.constant += part_size_in_regs;
4073
4074 if (!in_regs || reg_parm_stack_space > 0)
4075 pad_to_arg_alignment (&locate->slot_offset, boundary,
4076 &locate->alignment_pad);
4077
4078 locate->size.constant = (-initial_offset_ptr->constant
4079 - locate->slot_offset.constant);
4080 if (initial_offset_ptr->var)
4081 locate->size.var = size_binop (MINUS_EXPR,
4082 size_binop (MINUS_EXPR,
4083 ssize_int (0),
4084 initial_offset_ptr->var),
4085 locate->slot_offset.var);
4086
4087 /* Pad_below needs the pre-rounded size to know how much to pad
4088 below. */
4089 locate->offset = locate->slot_offset;
4090 if (where_pad == PAD_DOWNWARD)
4091 pad_below (&locate->offset, passed_mode, sizetree);
4092
4093 }
4094 else
4095 {
4096 if (!in_regs || reg_parm_stack_space > 0)
4097 pad_to_arg_alignment (initial_offset_ptr, boundary,
4098 &locate->alignment_pad);
4099 locate->slot_offset = *initial_offset_ptr;
4100
4101 #ifdef PUSH_ROUNDING
4102 if (passed_mode != BLKmode)
4103 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
4104 #endif
4105
4106 /* Pad_below needs the pre-rounded size to know how much to pad below
4107 so this must be done before rounding up. */
4108 locate->offset = locate->slot_offset;
4109 if (where_pad == PAD_DOWNWARD)
4110 pad_below (&locate->offset, passed_mode, sizetree);
4111
4112 if (where_pad != PAD_NONE
4113 && (!tree_fits_uhwi_p (sizetree)
4114 || (tree_to_uhwi (sizetree) * BITS_PER_UNIT) % round_boundary))
4115 sizetree = round_up (sizetree, round_boundary / BITS_PER_UNIT);
4116
4117 ADD_PARM_SIZE (locate->size, sizetree);
4118
4119 locate->size.constant -= part_size_in_regs;
4120 }
4121
4122 locate->offset.constant
4123 += targetm.calls.function_arg_offset (passed_mode, type);
4124 }
4125
4126 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
4127 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
4128
4129 static void
4130 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
4131 struct args_size *alignment_pad)
4132 {
4133 tree save_var = NULL_TREE;
4134 poly_int64 save_constant = 0;
4135 int boundary_in_bytes = boundary / BITS_PER_UNIT;
4136 poly_int64 sp_offset = STACK_POINTER_OFFSET;
4137
4138 #ifdef SPARC_STACK_BOUNDARY_HACK
4139 /* ??? The SPARC port may claim a STACK_BOUNDARY higher than
4140 the real alignment of %sp. However, when it does this, the
4141 alignment of %sp+STACK_POINTER_OFFSET is STACK_BOUNDARY. */
4142 if (SPARC_STACK_BOUNDARY_HACK)
4143 sp_offset = 0;
4144 #endif
4145
4146 if (boundary > PARM_BOUNDARY)
4147 {
4148 save_var = offset_ptr->var;
4149 save_constant = offset_ptr->constant;
4150 }
4151
4152 alignment_pad->var = NULL_TREE;
4153 alignment_pad->constant = 0;
4154
4155 if (boundary > BITS_PER_UNIT)
4156 {
4157 int misalign;
4158 if (offset_ptr->var
4159 || !known_misalignment (offset_ptr->constant + sp_offset,
4160 boundary_in_bytes, &misalign))
4161 {
4162 tree sp_offset_tree = ssize_int (sp_offset);
4163 tree offset = size_binop (PLUS_EXPR,
4164 ARGS_SIZE_TREE (*offset_ptr),
4165 sp_offset_tree);
4166 tree rounded;
4167 if (ARGS_GROW_DOWNWARD)
4168 rounded = round_down (offset, boundary / BITS_PER_UNIT);
4169 else
4170 rounded = round_up (offset, boundary / BITS_PER_UNIT);
4171
4172 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
4173 /* ARGS_SIZE_TREE includes constant term. */
4174 offset_ptr->constant = 0;
4175 if (boundary > PARM_BOUNDARY)
4176 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
4177 save_var);
4178 }
4179 else
4180 {
4181 if (ARGS_GROW_DOWNWARD)
4182 offset_ptr->constant -= misalign;
4183 else
4184 offset_ptr->constant += -misalign & (boundary_in_bytes - 1);
4185
4186 if (boundary > PARM_BOUNDARY)
4187 alignment_pad->constant = offset_ptr->constant - save_constant;
4188 }
4189 }
4190 }
4191
4192 static void
4193 pad_below (struct args_size *offset_ptr, machine_mode passed_mode, tree sizetree)
4194 {
4195 unsigned int align = PARM_BOUNDARY / BITS_PER_UNIT;
4196 int misalign;
4197 if (passed_mode != BLKmode
4198 && known_misalignment (GET_MODE_SIZE (passed_mode), align, &misalign))
4199 offset_ptr->constant += -misalign & (align - 1);
4200 else
4201 {
4202 if (TREE_CODE (sizetree) != INTEGER_CST
4203 || (TREE_INT_CST_LOW (sizetree) & (align - 1)) != 0)
4204 {
4205 /* Round the size up to multiple of PARM_BOUNDARY bits. */
4206 tree s2 = round_up (sizetree, align);
4207 /* Add it in. */
4208 ADD_PARM_SIZE (*offset_ptr, s2);
4209 SUB_PARM_SIZE (*offset_ptr, sizetree);
4210 }
4211 }
4212 }
4213 \f
4214
4215 /* True if register REGNO was alive at a place where `setjmp' was
4216 called and was set more than once or is an argument. Such regs may
4217 be clobbered by `longjmp'. */
4218
4219 static bool
4220 regno_clobbered_at_setjmp (bitmap setjmp_crosses, int regno)
4221 {
4222 /* There appear to be cases where some local vars never reach the
4223 backend but have bogus regnos. */
4224 if (regno >= max_reg_num ())
4225 return false;
4226
4227 return ((REG_N_SETS (regno) > 1
4228 || REGNO_REG_SET_P (df_get_live_out (ENTRY_BLOCK_PTR_FOR_FN (cfun)),
4229 regno))
4230 && REGNO_REG_SET_P (setjmp_crosses, regno));
4231 }
4232
4233 /* Walk the tree of blocks describing the binding levels within a
4234 function and warn about variables the might be killed by setjmp or
4235 vfork. This is done after calling flow_analysis before register
4236 allocation since that will clobber the pseudo-regs to hard
4237 regs. */
4238
4239 static void
4240 setjmp_vars_warning (bitmap setjmp_crosses, tree block)
4241 {
4242 tree decl, sub;
4243
4244 for (decl = BLOCK_VARS (block); decl; decl = DECL_CHAIN (decl))
4245 {
4246 if (VAR_P (decl)
4247 && DECL_RTL_SET_P (decl)
4248 && REG_P (DECL_RTL (decl))
4249 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
4250 warning (OPT_Wclobbered, "variable %q+D might be clobbered by"
4251 " %<longjmp%> or %<vfork%>", decl);
4252 }
4253
4254 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = BLOCK_CHAIN (sub))
4255 setjmp_vars_warning (setjmp_crosses, sub);
4256 }
4257
4258 /* Do the appropriate part of setjmp_vars_warning
4259 but for arguments instead of local variables. */
4260
4261 static void
4262 setjmp_args_warning (bitmap setjmp_crosses)
4263 {
4264 tree decl;
4265 for (decl = DECL_ARGUMENTS (current_function_decl);
4266 decl; decl = DECL_CHAIN (decl))
4267 if (DECL_RTL (decl) != 0
4268 && REG_P (DECL_RTL (decl))
4269 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
4270 warning (OPT_Wclobbered,
4271 "argument %q+D might be clobbered by %<longjmp%> or %<vfork%>",
4272 decl);
4273 }
4274
4275 /* Generate warning messages for variables live across setjmp. */
4276
4277 void
4278 generate_setjmp_warnings (void)
4279 {
4280 bitmap setjmp_crosses = regstat_get_setjmp_crosses ();
4281
4282 if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS
4283 || bitmap_empty_p (setjmp_crosses))
4284 return;
4285
4286 setjmp_vars_warning (setjmp_crosses, DECL_INITIAL (current_function_decl));
4287 setjmp_args_warning (setjmp_crosses);
4288 }
4289
4290 \f
4291 /* Reverse the order of elements in the fragment chain T of blocks,
4292 and return the new head of the chain (old last element).
4293 In addition to that clear BLOCK_SAME_RANGE flags when needed
4294 and adjust BLOCK_SUPERCONTEXT from the super fragment to
4295 its super fragment origin. */
4296
4297 static tree
4298 block_fragments_nreverse (tree t)
4299 {
4300 tree prev = 0, block, next, prev_super = 0;
4301 tree super = BLOCK_SUPERCONTEXT (t);
4302 if (BLOCK_FRAGMENT_ORIGIN (super))
4303 super = BLOCK_FRAGMENT_ORIGIN (super);
4304 for (block = t; block; block = next)
4305 {
4306 next = BLOCK_FRAGMENT_CHAIN (block);
4307 BLOCK_FRAGMENT_CHAIN (block) = prev;
4308 if ((prev && !BLOCK_SAME_RANGE (prev))
4309 || (BLOCK_FRAGMENT_CHAIN (BLOCK_SUPERCONTEXT (block))
4310 != prev_super))
4311 BLOCK_SAME_RANGE (block) = 0;
4312 prev_super = BLOCK_SUPERCONTEXT (block);
4313 BLOCK_SUPERCONTEXT (block) = super;
4314 prev = block;
4315 }
4316 t = BLOCK_FRAGMENT_ORIGIN (t);
4317 if (BLOCK_FRAGMENT_CHAIN (BLOCK_SUPERCONTEXT (t))
4318 != prev_super)
4319 BLOCK_SAME_RANGE (t) = 0;
4320 BLOCK_SUPERCONTEXT (t) = super;
4321 return prev;
4322 }
4323
4324 /* Reverse the order of elements in the chain T of blocks,
4325 and return the new head of the chain (old last element).
4326 Also do the same on subblocks and reverse the order of elements
4327 in BLOCK_FRAGMENT_CHAIN as well. */
4328
4329 static tree
4330 blocks_nreverse_all (tree t)
4331 {
4332 tree prev = 0, block, next;
4333 for (block = t; block; block = next)
4334 {
4335 next = BLOCK_CHAIN (block);
4336 BLOCK_CHAIN (block) = prev;
4337 if (BLOCK_FRAGMENT_CHAIN (block)
4338 && BLOCK_FRAGMENT_ORIGIN (block) == NULL_TREE)
4339 {
4340 BLOCK_FRAGMENT_CHAIN (block)
4341 = block_fragments_nreverse (BLOCK_FRAGMENT_CHAIN (block));
4342 if (!BLOCK_SAME_RANGE (BLOCK_FRAGMENT_CHAIN (block)))
4343 BLOCK_SAME_RANGE (block) = 0;
4344 }
4345 BLOCK_SUBBLOCKS (block) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block));
4346 prev = block;
4347 }
4348 return prev;
4349 }
4350
4351
4352 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
4353 and create duplicate blocks. */
4354 /* ??? Need an option to either create block fragments or to create
4355 abstract origin duplicates of a source block. It really depends
4356 on what optimization has been performed. */
4357
4358 void
4359 reorder_blocks (void)
4360 {
4361 tree block = DECL_INITIAL (current_function_decl);
4362
4363 if (block == NULL_TREE)
4364 return;
4365
4366 auto_vec<tree, 10> block_stack;
4367
4368 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
4369 clear_block_marks (block);
4370
4371 /* Prune the old trees away, so that they don't get in the way. */
4372 BLOCK_SUBBLOCKS (block) = NULL_TREE;
4373 BLOCK_CHAIN (block) = NULL_TREE;
4374
4375 /* Recreate the block tree from the note nesting. */
4376 reorder_blocks_1 (get_insns (), block, &block_stack);
4377 BLOCK_SUBBLOCKS (block) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block));
4378 }
4379
4380 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
4381
4382 void
4383 clear_block_marks (tree block)
4384 {
4385 while (block)
4386 {
4387 TREE_ASM_WRITTEN (block) = 0;
4388 clear_block_marks (BLOCK_SUBBLOCKS (block));
4389 block = BLOCK_CHAIN (block);
4390 }
4391 }
4392
4393 static void
4394 reorder_blocks_1 (rtx_insn *insns, tree current_block,
4395 vec<tree> *p_block_stack)
4396 {
4397 rtx_insn *insn;
4398 tree prev_beg = NULL_TREE, prev_end = NULL_TREE;
4399
4400 for (insn = insns; insn; insn = NEXT_INSN (insn))
4401 {
4402 if (NOTE_P (insn))
4403 {
4404 if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_BEG)
4405 {
4406 tree block = NOTE_BLOCK (insn);
4407 tree origin;
4408
4409 gcc_assert (BLOCK_FRAGMENT_ORIGIN (block) == NULL_TREE);
4410 origin = block;
4411
4412 if (prev_end)
4413 BLOCK_SAME_RANGE (prev_end) = 0;
4414 prev_end = NULL_TREE;
4415
4416 /* If we have seen this block before, that means it now
4417 spans multiple address regions. Create a new fragment. */
4418 if (TREE_ASM_WRITTEN (block))
4419 {
4420 tree new_block = copy_node (block);
4421
4422 BLOCK_SAME_RANGE (new_block) = 0;
4423 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
4424 BLOCK_FRAGMENT_CHAIN (new_block)
4425 = BLOCK_FRAGMENT_CHAIN (origin);
4426 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
4427
4428 NOTE_BLOCK (insn) = new_block;
4429 block = new_block;
4430 }
4431
4432 if (prev_beg == current_block && prev_beg)
4433 BLOCK_SAME_RANGE (block) = 1;
4434
4435 prev_beg = origin;
4436
4437 BLOCK_SUBBLOCKS (block) = 0;
4438 TREE_ASM_WRITTEN (block) = 1;
4439 /* When there's only one block for the entire function,
4440 current_block == block and we mustn't do this, it
4441 will cause infinite recursion. */
4442 if (block != current_block)
4443 {
4444 tree super;
4445 if (block != origin)
4446 gcc_assert (BLOCK_SUPERCONTEXT (origin) == current_block
4447 || BLOCK_FRAGMENT_ORIGIN (BLOCK_SUPERCONTEXT
4448 (origin))
4449 == current_block);
4450 if (p_block_stack->is_empty ())
4451 super = current_block;
4452 else
4453 {
4454 super = p_block_stack->last ();
4455 gcc_assert (super == current_block
4456 || BLOCK_FRAGMENT_ORIGIN (super)
4457 == current_block);
4458 }
4459 BLOCK_SUPERCONTEXT (block) = super;
4460 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
4461 BLOCK_SUBBLOCKS (current_block) = block;
4462 current_block = origin;
4463 }
4464 p_block_stack->safe_push (block);
4465 }
4466 else if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_END)
4467 {
4468 NOTE_BLOCK (insn) = p_block_stack->pop ();
4469 current_block = BLOCK_SUPERCONTEXT (current_block);
4470 if (BLOCK_FRAGMENT_ORIGIN (current_block))
4471 current_block = BLOCK_FRAGMENT_ORIGIN (current_block);
4472 prev_beg = NULL_TREE;
4473 prev_end = BLOCK_SAME_RANGE (NOTE_BLOCK (insn))
4474 ? NOTE_BLOCK (insn) : NULL_TREE;
4475 }
4476 }
4477 else
4478 {
4479 prev_beg = NULL_TREE;
4480 if (prev_end)
4481 BLOCK_SAME_RANGE (prev_end) = 0;
4482 prev_end = NULL_TREE;
4483 }
4484 }
4485 }
4486
4487 /* Reverse the order of elements in the chain T of blocks,
4488 and return the new head of the chain (old last element). */
4489
4490 tree
4491 blocks_nreverse (tree t)
4492 {
4493 tree prev = 0, block, next;
4494 for (block = t; block; block = next)
4495 {
4496 next = BLOCK_CHAIN (block);
4497 BLOCK_CHAIN (block) = prev;
4498 prev = block;
4499 }
4500 return prev;
4501 }
4502
4503 /* Concatenate two chains of blocks (chained through BLOCK_CHAIN)
4504 by modifying the last node in chain 1 to point to chain 2. */
4505
4506 tree
4507 block_chainon (tree op1, tree op2)
4508 {
4509 tree t1;
4510
4511 if (!op1)
4512 return op2;
4513 if (!op2)
4514 return op1;
4515
4516 for (t1 = op1; BLOCK_CHAIN (t1); t1 = BLOCK_CHAIN (t1))
4517 continue;
4518 BLOCK_CHAIN (t1) = op2;
4519
4520 #ifdef ENABLE_TREE_CHECKING
4521 {
4522 tree t2;
4523 for (t2 = op2; t2; t2 = BLOCK_CHAIN (t2))
4524 gcc_assert (t2 != t1);
4525 }
4526 #endif
4527
4528 return op1;
4529 }
4530
4531 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
4532 non-NULL, list them all into VECTOR, in a depth-first preorder
4533 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
4534 blocks. */
4535
4536 static int
4537 all_blocks (tree block, tree *vector)
4538 {
4539 int n_blocks = 0;
4540
4541 while (block)
4542 {
4543 TREE_ASM_WRITTEN (block) = 0;
4544
4545 /* Record this block. */
4546 if (vector)
4547 vector[n_blocks] = block;
4548
4549 ++n_blocks;
4550
4551 /* Record the subblocks, and their subblocks... */
4552 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
4553 vector ? vector + n_blocks : 0);
4554 block = BLOCK_CHAIN (block);
4555 }
4556
4557 return n_blocks;
4558 }
4559
4560 /* Return a vector containing all the blocks rooted at BLOCK. The
4561 number of elements in the vector is stored in N_BLOCKS_P. The
4562 vector is dynamically allocated; it is the caller's responsibility
4563 to call `free' on the pointer returned. */
4564
4565 static tree *
4566 get_block_vector (tree block, int *n_blocks_p)
4567 {
4568 tree *block_vector;
4569
4570 *n_blocks_p = all_blocks (block, NULL);
4571 block_vector = XNEWVEC (tree, *n_blocks_p);
4572 all_blocks (block, block_vector);
4573
4574 return block_vector;
4575 }
4576
4577 static GTY(()) int next_block_index = 2;
4578
4579 /* Set BLOCK_NUMBER for all the blocks in FN. */
4580
4581 void
4582 number_blocks (tree fn)
4583 {
4584 int i;
4585 int n_blocks;
4586 tree *block_vector;
4587
4588 /* For XCOFF debugging output, we start numbering the blocks
4589 from 1 within each function, rather than keeping a running
4590 count. */
4591 #if defined (XCOFF_DEBUGGING_INFO)
4592 if (write_symbols == XCOFF_DEBUG)
4593 next_block_index = 1;
4594 #endif
4595
4596 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
4597
4598 /* The top-level BLOCK isn't numbered at all. */
4599 for (i = 1; i < n_blocks; ++i)
4600 /* We number the blocks from two. */
4601 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
4602
4603 free (block_vector);
4604
4605 return;
4606 }
4607
4608 /* If VAR is present in a subblock of BLOCK, return the subblock. */
4609
4610 DEBUG_FUNCTION tree
4611 debug_find_var_in_block_tree (tree var, tree block)
4612 {
4613 tree t;
4614
4615 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
4616 if (t == var)
4617 return block;
4618
4619 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
4620 {
4621 tree ret = debug_find_var_in_block_tree (var, t);
4622 if (ret)
4623 return ret;
4624 }
4625
4626 return NULL_TREE;
4627 }
4628 \f
4629 /* Keep track of whether we're in a dummy function context. If we are,
4630 we don't want to invoke the set_current_function hook, because we'll
4631 get into trouble if the hook calls target_reinit () recursively or
4632 when the initial initialization is not yet complete. */
4633
4634 static bool in_dummy_function;
4635
4636 /* Invoke the target hook when setting cfun. Update the optimization options
4637 if the function uses different options than the default. */
4638
4639 static void
4640 invoke_set_current_function_hook (tree fndecl)
4641 {
4642 if (!in_dummy_function)
4643 {
4644 tree opts = ((fndecl)
4645 ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (fndecl)
4646 : optimization_default_node);
4647
4648 if (!opts)
4649 opts = optimization_default_node;
4650
4651 /* Change optimization options if needed. */
4652 if (optimization_current_node != opts)
4653 {
4654 optimization_current_node = opts;
4655 cl_optimization_restore (&global_options, TREE_OPTIMIZATION (opts));
4656 }
4657
4658 targetm.set_current_function (fndecl);
4659 this_fn_optabs = this_target_optabs;
4660
4661 /* Initialize global alignment variables after op. */
4662 parse_alignment_opts ();
4663
4664 if (opts != optimization_default_node)
4665 {
4666 init_tree_optimization_optabs (opts);
4667 if (TREE_OPTIMIZATION_OPTABS (opts))
4668 this_fn_optabs = (struct target_optabs *)
4669 TREE_OPTIMIZATION_OPTABS (opts);
4670 }
4671 }
4672 }
4673
4674 /* cfun should never be set directly; use this function. */
4675
4676 void
4677 set_cfun (struct function *new_cfun, bool force)
4678 {
4679 if (cfun != new_cfun || force)
4680 {
4681 cfun = new_cfun;
4682 invoke_set_current_function_hook (new_cfun ? new_cfun->decl : NULL_TREE);
4683 redirect_edge_var_map_empty ();
4684 }
4685 }
4686
4687 /* Initialized with NOGC, making this poisonous to the garbage collector. */
4688
4689 static vec<function *> cfun_stack;
4690
4691 /* Push the current cfun onto the stack, and set cfun to new_cfun. Also set
4692 current_function_decl accordingly. */
4693
4694 void
4695 push_cfun (struct function *new_cfun)
4696 {
4697 gcc_assert ((!cfun && !current_function_decl)
4698 || (cfun && current_function_decl == cfun->decl));
4699 cfun_stack.safe_push (cfun);
4700 current_function_decl = new_cfun ? new_cfun->decl : NULL_TREE;
4701 set_cfun (new_cfun);
4702 }
4703
4704 /* Pop cfun from the stack. Also set current_function_decl accordingly. */
4705
4706 void
4707 pop_cfun (void)
4708 {
4709 struct function *new_cfun = cfun_stack.pop ();
4710 /* When in_dummy_function, we do have a cfun but current_function_decl is
4711 NULL. We also allow pushing NULL cfun and subsequently changing
4712 current_function_decl to something else and have both restored by
4713 pop_cfun. */
4714 gcc_checking_assert (in_dummy_function
4715 || !cfun
4716 || current_function_decl == cfun->decl);
4717 set_cfun (new_cfun);
4718 current_function_decl = new_cfun ? new_cfun->decl : NULL_TREE;
4719 }
4720
4721 /* Return value of funcdef and increase it. */
4722 int
4723 get_next_funcdef_no (void)
4724 {
4725 return funcdef_no++;
4726 }
4727
4728 /* Return value of funcdef. */
4729 int
4730 get_last_funcdef_no (void)
4731 {
4732 return funcdef_no;
4733 }
4734
4735 /* Allocate a function structure for FNDECL and set its contents
4736 to the defaults. Set cfun to the newly-allocated object.
4737 Some of the helper functions invoked during initialization assume
4738 that cfun has already been set. Therefore, assign the new object
4739 directly into cfun and invoke the back end hook explicitly at the
4740 very end, rather than initializing a temporary and calling set_cfun
4741 on it.
4742
4743 ABSTRACT_P is true if this is a function that will never be seen by
4744 the middle-end. Such functions are front-end concepts (like C++
4745 function templates) that do not correspond directly to functions
4746 placed in object files. */
4747
4748 void
4749 allocate_struct_function (tree fndecl, bool abstract_p)
4750 {
4751 tree fntype = fndecl ? TREE_TYPE (fndecl) : NULL_TREE;
4752
4753 cfun = ggc_cleared_alloc<function> ();
4754
4755 init_eh_for_function ();
4756
4757 if (init_machine_status)
4758 cfun->machine = (*init_machine_status) ();
4759
4760 #ifdef OVERRIDE_ABI_FORMAT
4761 OVERRIDE_ABI_FORMAT (fndecl);
4762 #endif
4763
4764 if (fndecl != NULL_TREE)
4765 {
4766 DECL_STRUCT_FUNCTION (fndecl) = cfun;
4767 cfun->decl = fndecl;
4768 current_function_funcdef_no = get_next_funcdef_no ();
4769 }
4770
4771 invoke_set_current_function_hook (fndecl);
4772
4773 if (fndecl != NULL_TREE)
4774 {
4775 tree result = DECL_RESULT (fndecl);
4776
4777 if (!abstract_p)
4778 {
4779 /* Now that we have activated any function-specific attributes
4780 that might affect layout, particularly vector modes, relayout
4781 each of the parameters and the result. */
4782 relayout_decl (result);
4783 for (tree parm = DECL_ARGUMENTS (fndecl); parm;
4784 parm = DECL_CHAIN (parm))
4785 relayout_decl (parm);
4786
4787 /* Similarly relayout the function decl. */
4788 targetm.target_option.relayout_function (fndecl);
4789 }
4790
4791 if (!abstract_p && aggregate_value_p (result, fndecl))
4792 {
4793 #ifdef PCC_STATIC_STRUCT_RETURN
4794 cfun->returns_pcc_struct = 1;
4795 #endif
4796 cfun->returns_struct = 1;
4797 }
4798
4799 cfun->stdarg = stdarg_p (fntype);
4800
4801 /* Assume all registers in stdarg functions need to be saved. */
4802 cfun->va_list_gpr_size = VA_LIST_MAX_GPR_SIZE;
4803 cfun->va_list_fpr_size = VA_LIST_MAX_FPR_SIZE;
4804
4805 /* ??? This could be set on a per-function basis by the front-end
4806 but is this worth the hassle? */
4807 cfun->can_throw_non_call_exceptions = flag_non_call_exceptions;
4808 cfun->can_delete_dead_exceptions = flag_delete_dead_exceptions;
4809
4810 if (!profile_flag && !flag_instrument_function_entry_exit)
4811 DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl) = 1;
4812 }
4813
4814 /* Don't enable begin stmt markers if var-tracking at assignments is
4815 disabled. The markers make little sense without the variable
4816 binding annotations among them. */
4817 cfun->debug_nonbind_markers = lang_hooks.emits_begin_stmt
4818 && MAY_HAVE_DEBUG_MARKER_STMTS;
4819 }
4820
4821 /* This is like allocate_struct_function, but pushes a new cfun for FNDECL
4822 instead of just setting it. */
4823
4824 void
4825 push_struct_function (tree fndecl)
4826 {
4827 /* When in_dummy_function we might be in the middle of a pop_cfun and
4828 current_function_decl and cfun may not match. */
4829 gcc_assert (in_dummy_function
4830 || (!cfun && !current_function_decl)
4831 || (cfun && current_function_decl == cfun->decl));
4832 cfun_stack.safe_push (cfun);
4833 current_function_decl = fndecl;
4834 allocate_struct_function (fndecl, false);
4835 }
4836
4837 /* Reset crtl and other non-struct-function variables to defaults as
4838 appropriate for emitting rtl at the start of a function. */
4839
4840 static void
4841 prepare_function_start (void)
4842 {
4843 gcc_assert (!get_last_insn ());
4844 init_temp_slots ();
4845 init_emit ();
4846 init_varasm_status ();
4847 init_expr ();
4848 default_rtl_profile ();
4849
4850 if (flag_stack_usage_info)
4851 {
4852 cfun->su = ggc_cleared_alloc<stack_usage> ();
4853 cfun->su->static_stack_size = -1;
4854 }
4855
4856 cse_not_expected = ! optimize;
4857
4858 /* Caller save not needed yet. */
4859 caller_save_needed = 0;
4860
4861 /* We haven't done register allocation yet. */
4862 reg_renumber = 0;
4863
4864 /* Indicate that we have not instantiated virtual registers yet. */
4865 virtuals_instantiated = 0;
4866
4867 /* Indicate that we want CONCATs now. */
4868 generating_concat_p = 1;
4869
4870 /* Indicate we have no need of a frame pointer yet. */
4871 frame_pointer_needed = 0;
4872 }
4873
4874 void
4875 push_dummy_function (bool with_decl)
4876 {
4877 tree fn_decl, fn_type, fn_result_decl;
4878
4879 gcc_assert (!in_dummy_function);
4880 in_dummy_function = true;
4881
4882 if (with_decl)
4883 {
4884 fn_type = build_function_type_list (void_type_node, NULL_TREE);
4885 fn_decl = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL, NULL_TREE,
4886 fn_type);
4887 fn_result_decl = build_decl (UNKNOWN_LOCATION, RESULT_DECL,
4888 NULL_TREE, void_type_node);
4889 DECL_RESULT (fn_decl) = fn_result_decl;
4890 }
4891 else
4892 fn_decl = NULL_TREE;
4893
4894 push_struct_function (fn_decl);
4895 }
4896
4897 /* Initialize the rtl expansion mechanism so that we can do simple things
4898 like generate sequences. This is used to provide a context during global
4899 initialization of some passes. You must call expand_dummy_function_end
4900 to exit this context. */
4901
4902 void
4903 init_dummy_function_start (void)
4904 {
4905 push_dummy_function (false);
4906 prepare_function_start ();
4907 }
4908
4909 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
4910 and initialize static variables for generating RTL for the statements
4911 of the function. */
4912
4913 void
4914 init_function_start (tree subr)
4915 {
4916 /* Initialize backend, if needed. */
4917 initialize_rtl ();
4918
4919 prepare_function_start ();
4920 decide_function_section (subr);
4921
4922 /* Warn if this value is an aggregate type,
4923 regardless of which calling convention we are using for it. */
4924 if (AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
4925 warning (OPT_Waggregate_return, "function returns an aggregate");
4926 }
4927
4928 /* Expand code to verify the stack_protect_guard. This is invoked at
4929 the end of a function to be protected. */
4930
4931 void
4932 stack_protect_epilogue (void)
4933 {
4934 tree guard_decl = crtl->stack_protect_guard_decl;
4935 rtx_code_label *label = gen_label_rtx ();
4936 rtx x, y;
4937 rtx_insn *seq = NULL;
4938
4939 x = expand_normal (crtl->stack_protect_guard);
4940
4941 if (targetm.have_stack_protect_combined_test () && guard_decl)
4942 {
4943 gcc_assert (DECL_P (guard_decl));
4944 y = DECL_RTL (guard_decl);
4945 /* Allow the target to compute address of Y and compare it with X without
4946 leaking Y into a register. This combined address + compare pattern
4947 allows the target to prevent spilling of any intermediate results by
4948 splitting it after register allocator. */
4949 seq = targetm.gen_stack_protect_combined_test (x, y, label);
4950 }
4951 else
4952 {
4953 if (guard_decl)
4954 y = expand_normal (guard_decl);
4955 else
4956 y = const0_rtx;
4957
4958 /* Allow the target to compare Y with X without leaking either into
4959 a register. */
4960 if (targetm.have_stack_protect_test ())
4961 seq = targetm.gen_stack_protect_test (x, y, label);
4962 }
4963
4964 if (seq)
4965 emit_insn (seq);
4966 else
4967 emit_cmp_and_jump_insns (x, y, EQ, NULL_RTX, ptr_mode, 1, label);
4968
4969 /* The noreturn predictor has been moved to the tree level. The rtl-level
4970 predictors estimate this branch about 20%, which isn't enough to get
4971 things moved out of line. Since this is the only extant case of adding
4972 a noreturn function at the rtl level, it doesn't seem worth doing ought
4973 except adding the prediction by hand. */
4974 rtx_insn *tmp = get_last_insn ();
4975 if (JUMP_P (tmp))
4976 predict_insn_def (tmp, PRED_NORETURN, TAKEN);
4977
4978 expand_call (targetm.stack_protect_fail (), NULL_RTX, /*ignore=*/true);
4979 free_temp_slots ();
4980 emit_label (label);
4981 }
4982 \f
4983 /* Start the RTL for a new function, and set variables used for
4984 emitting RTL.
4985 SUBR is the FUNCTION_DECL node.
4986 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
4987 the function's parameters, which must be run at any return statement. */
4988
4989 void
4990 expand_function_start (tree subr)
4991 {
4992 /* Make sure volatile mem refs aren't considered
4993 valid operands of arithmetic insns. */
4994 init_recog_no_volatile ();
4995
4996 crtl->profile
4997 = (profile_flag
4998 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
4999
5000 crtl->limit_stack
5001 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
5002
5003 /* Make the label for return statements to jump to. Do not special
5004 case machines with special return instructions -- they will be
5005 handled later during jump, ifcvt, or epilogue creation. */
5006 return_label = gen_label_rtx ();
5007
5008 /* Initialize rtx used to return the value. */
5009 /* Do this before assign_parms so that we copy the struct value address
5010 before any library calls that assign parms might generate. */
5011
5012 /* Decide whether to return the value in memory or in a register. */
5013 tree res = DECL_RESULT (subr);
5014 if (aggregate_value_p (res, subr))
5015 {
5016 /* Returning something that won't go in a register. */
5017 rtx value_address = 0;
5018
5019 #ifdef PCC_STATIC_STRUCT_RETURN
5020 if (cfun->returns_pcc_struct)
5021 {
5022 int size = int_size_in_bytes (TREE_TYPE (res));
5023 value_address = assemble_static_space (size);
5024 }
5025 else
5026 #endif
5027 {
5028 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 2);
5029 /* Expect to be passed the address of a place to store the value.
5030 If it is passed as an argument, assign_parms will take care of
5031 it. */
5032 if (sv)
5033 {
5034 value_address = gen_reg_rtx (Pmode);
5035 emit_move_insn (value_address, sv);
5036 }
5037 }
5038 if (value_address)
5039 {
5040 rtx x = value_address;
5041 if (!DECL_BY_REFERENCE (res))
5042 {
5043 x = gen_rtx_MEM (DECL_MODE (res), x);
5044 set_mem_attributes (x, res, 1);
5045 }
5046 set_parm_rtl (res, x);
5047 }
5048 }
5049 else if (DECL_MODE (res) == VOIDmode)
5050 /* If return mode is void, this decl rtl should not be used. */
5051 set_parm_rtl (res, NULL_RTX);
5052 else
5053 {
5054 /* Compute the return values into a pseudo reg, which we will copy
5055 into the true return register after the cleanups are done. */
5056 tree return_type = TREE_TYPE (res);
5057
5058 /* If we may coalesce this result, make sure it has the expected mode
5059 in case it was promoted. But we need not bother about BLKmode. */
5060 machine_mode promoted_mode
5061 = flag_tree_coalesce_vars && is_gimple_reg (res)
5062 ? promote_ssa_mode (ssa_default_def (cfun, res), NULL)
5063 : BLKmode;
5064
5065 if (promoted_mode != BLKmode)
5066 set_parm_rtl (res, gen_reg_rtx (promoted_mode));
5067 else if (TYPE_MODE (return_type) != BLKmode
5068 && targetm.calls.return_in_msb (return_type))
5069 /* expand_function_end will insert the appropriate padding in
5070 this case. Use the return value's natural (unpadded) mode
5071 within the function proper. */
5072 set_parm_rtl (res, gen_reg_rtx (TYPE_MODE (return_type)));
5073 else
5074 {
5075 /* In order to figure out what mode to use for the pseudo, we
5076 figure out what the mode of the eventual return register will
5077 actually be, and use that. */
5078 rtx hard_reg = hard_function_value (return_type, subr, 0, 1);
5079
5080 /* Structures that are returned in registers are not
5081 aggregate_value_p, so we may see a PARALLEL or a REG. */
5082 if (REG_P (hard_reg))
5083 set_parm_rtl (res, gen_reg_rtx (GET_MODE (hard_reg)));
5084 else
5085 {
5086 gcc_assert (GET_CODE (hard_reg) == PARALLEL);
5087 set_parm_rtl (res, gen_group_rtx (hard_reg));
5088 }
5089 }
5090
5091 /* Set DECL_REGISTER flag so that expand_function_end will copy the
5092 result to the real return register(s). */
5093 DECL_REGISTER (res) = 1;
5094 }
5095
5096 /* Initialize rtx for parameters and local variables.
5097 In some cases this requires emitting insns. */
5098 assign_parms (subr);
5099
5100 /* If function gets a static chain arg, store it. */
5101 if (cfun->static_chain_decl)
5102 {
5103 tree parm = cfun->static_chain_decl;
5104 rtx local, chain;
5105 rtx_insn *insn;
5106 int unsignedp;
5107
5108 local = gen_reg_rtx (promote_decl_mode (parm, &unsignedp));
5109 chain = targetm.calls.static_chain (current_function_decl, true);
5110
5111 set_decl_incoming_rtl (parm, chain, false);
5112 set_parm_rtl (parm, local);
5113 mark_reg_pointer (local, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
5114
5115 if (GET_MODE (local) != GET_MODE (chain))
5116 {
5117 convert_move (local, chain, unsignedp);
5118 insn = get_last_insn ();
5119 }
5120 else
5121 insn = emit_move_insn (local, chain);
5122
5123 /* Mark the register as eliminable, similar to parameters. */
5124 if (MEM_P (chain)
5125 && reg_mentioned_p (arg_pointer_rtx, XEXP (chain, 0)))
5126 set_dst_reg_note (insn, REG_EQUIV, chain, local);
5127
5128 /* If we aren't optimizing, save the static chain onto the stack. */
5129 if (!optimize)
5130 {
5131 tree saved_static_chain_decl
5132 = build_decl (DECL_SOURCE_LOCATION (parm), VAR_DECL,
5133 DECL_NAME (parm), TREE_TYPE (parm));
5134 rtx saved_static_chain_rtx
5135 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
5136 SET_DECL_RTL (saved_static_chain_decl, saved_static_chain_rtx);
5137 emit_move_insn (saved_static_chain_rtx, chain);
5138 SET_DECL_VALUE_EXPR (parm, saved_static_chain_decl);
5139 DECL_HAS_VALUE_EXPR_P (parm) = 1;
5140 }
5141 }
5142
5143 /* The following was moved from init_function_start.
5144 The move was supposed to make sdb output more accurate. */
5145 /* Indicate the beginning of the function body,
5146 as opposed to parm setup. */
5147 emit_note (NOTE_INSN_FUNCTION_BEG);
5148
5149 gcc_assert (NOTE_P (get_last_insn ()));
5150
5151 parm_birth_insn = get_last_insn ();
5152
5153 /* If the function receives a non-local goto, then store the
5154 bits we need to restore the frame pointer. */
5155 if (cfun->nonlocal_goto_save_area)
5156 {
5157 tree t_save;
5158 rtx r_save;
5159
5160 tree var = TREE_OPERAND (cfun->nonlocal_goto_save_area, 0);
5161 gcc_assert (DECL_RTL_SET_P (var));
5162
5163 t_save = build4 (ARRAY_REF,
5164 TREE_TYPE (TREE_TYPE (cfun->nonlocal_goto_save_area)),
5165 cfun->nonlocal_goto_save_area,
5166 integer_zero_node, NULL_TREE, NULL_TREE);
5167 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
5168 gcc_assert (GET_MODE (r_save) == Pmode);
5169
5170 emit_move_insn (r_save, hard_frame_pointer_rtx);
5171 update_nonlocal_goto_save_area ();
5172 }
5173
5174 if (crtl->profile)
5175 {
5176 #ifdef PROFILE_HOOK
5177 PROFILE_HOOK (current_function_funcdef_no);
5178 #endif
5179 }
5180
5181 /* If we are doing generic stack checking, the probe should go here. */
5182 if (flag_stack_check == GENERIC_STACK_CHECK)
5183 stack_check_probe_note = emit_note (NOTE_INSN_DELETED);
5184 }
5185 \f
5186 void
5187 pop_dummy_function (void)
5188 {
5189 pop_cfun ();
5190 in_dummy_function = false;
5191 }
5192
5193 /* Undo the effects of init_dummy_function_start. */
5194 void
5195 expand_dummy_function_end (void)
5196 {
5197 gcc_assert (in_dummy_function);
5198
5199 /* End any sequences that failed to be closed due to syntax errors. */
5200 while (in_sequence_p ())
5201 end_sequence ();
5202
5203 /* Outside function body, can't compute type's actual size
5204 until next function's body starts. */
5205
5206 free_after_parsing (cfun);
5207 free_after_compilation (cfun);
5208 pop_dummy_function ();
5209 }
5210
5211 /* Helper for diddle_return_value. */
5212
5213 void
5214 diddle_return_value_1 (void (*doit) (rtx, void *), void *arg, rtx outgoing)
5215 {
5216 if (! outgoing)
5217 return;
5218
5219 if (REG_P (outgoing))
5220 (*doit) (outgoing, arg);
5221 else if (GET_CODE (outgoing) == PARALLEL)
5222 {
5223 int i;
5224
5225 for (i = 0; i < XVECLEN (outgoing, 0); i++)
5226 {
5227 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
5228
5229 if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
5230 (*doit) (x, arg);
5231 }
5232 }
5233 }
5234
5235 /* Call DOIT for each hard register used as a return value from
5236 the current function. */
5237
5238 void
5239 diddle_return_value (void (*doit) (rtx, void *), void *arg)
5240 {
5241 diddle_return_value_1 (doit, arg, crtl->return_rtx);
5242 }
5243
5244 static void
5245 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
5246 {
5247 emit_clobber (reg);
5248 }
5249
5250 void
5251 clobber_return_register (void)
5252 {
5253 diddle_return_value (do_clobber_return_reg, NULL);
5254
5255 /* In case we do use pseudo to return value, clobber it too. */
5256 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
5257 {
5258 tree decl_result = DECL_RESULT (current_function_decl);
5259 rtx decl_rtl = DECL_RTL (decl_result);
5260 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
5261 {
5262 do_clobber_return_reg (decl_rtl, NULL);
5263 }
5264 }
5265 }
5266
5267 static void
5268 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
5269 {
5270 emit_use (reg);
5271 }
5272
5273 static void
5274 use_return_register (void)
5275 {
5276 diddle_return_value (do_use_return_reg, NULL);
5277 }
5278
5279 /* Generate RTL for the end of the current function. */
5280
5281 void
5282 expand_function_end (void)
5283 {
5284 /* If arg_pointer_save_area was referenced only from a nested
5285 function, we will not have initialized it yet. Do that now. */
5286 if (arg_pointer_save_area && ! crtl->arg_pointer_save_area_init)
5287 get_arg_pointer_save_area ();
5288
5289 /* If we are doing generic stack checking and this function makes calls,
5290 do a stack probe at the start of the function to ensure we have enough
5291 space for another stack frame. */
5292 if (flag_stack_check == GENERIC_STACK_CHECK)
5293 {
5294 rtx_insn *insn, *seq;
5295
5296 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
5297 if (CALL_P (insn))
5298 {
5299 rtx max_frame_size = GEN_INT (STACK_CHECK_MAX_FRAME_SIZE);
5300 start_sequence ();
5301 if (STACK_CHECK_MOVING_SP)
5302 anti_adjust_stack_and_probe (max_frame_size, true);
5303 else
5304 probe_stack_range (STACK_OLD_CHECK_PROTECT, max_frame_size);
5305 seq = get_insns ();
5306 end_sequence ();
5307 set_insn_locations (seq, prologue_location);
5308 emit_insn_before (seq, stack_check_probe_note);
5309 break;
5310 }
5311 }
5312
5313 /* End any sequences that failed to be closed due to syntax errors. */
5314 while (in_sequence_p ())
5315 end_sequence ();
5316
5317 clear_pending_stack_adjust ();
5318 do_pending_stack_adjust ();
5319
5320 /* Output a linenumber for the end of the function.
5321 SDB depended on this. */
5322 set_curr_insn_location (input_location);
5323
5324 /* Before the return label (if any), clobber the return
5325 registers so that they are not propagated live to the rest of
5326 the function. This can only happen with functions that drop
5327 through; if there had been a return statement, there would
5328 have either been a return rtx, or a jump to the return label.
5329
5330 We delay actual code generation after the current_function_value_rtx
5331 is computed. */
5332 rtx_insn *clobber_after = get_last_insn ();
5333
5334 /* Output the label for the actual return from the function. */
5335 emit_label (return_label);
5336
5337 if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ)
5338 {
5339 /* Let except.c know where it should emit the call to unregister
5340 the function context for sjlj exceptions. */
5341 if (flag_exceptions)
5342 sjlj_emit_function_exit_after (get_last_insn ());
5343 }
5344
5345 /* If this is an implementation of throw, do what's necessary to
5346 communicate between __builtin_eh_return and the epilogue. */
5347 expand_eh_return ();
5348
5349 /* If stack protection is enabled for this function, check the guard. */
5350 if (crtl->stack_protect_guard
5351 && targetm.stack_protect_runtime_enabled_p ()
5352 && naked_return_label == NULL_RTX)
5353 stack_protect_epilogue ();
5354
5355 /* If scalar return value was computed in a pseudo-reg, or was a named
5356 return value that got dumped to the stack, copy that to the hard
5357 return register. */
5358 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
5359 {
5360 tree decl_result = DECL_RESULT (current_function_decl);
5361 rtx decl_rtl = DECL_RTL (decl_result);
5362
5363 if (REG_P (decl_rtl)
5364 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
5365 : DECL_REGISTER (decl_result))
5366 {
5367 rtx real_decl_rtl = crtl->return_rtx;
5368 complex_mode cmode;
5369
5370 /* This should be set in assign_parms. */
5371 gcc_assert (REG_FUNCTION_VALUE_P (real_decl_rtl));
5372
5373 /* If this is a BLKmode structure being returned in registers,
5374 then use the mode computed in expand_return. Note that if
5375 decl_rtl is memory, then its mode may have been changed,
5376 but that crtl->return_rtx has not. */
5377 if (GET_MODE (real_decl_rtl) == BLKmode)
5378 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
5379
5380 /* If a non-BLKmode return value should be padded at the least
5381 significant end of the register, shift it left by the appropriate
5382 amount. BLKmode results are handled using the group load/store
5383 machinery. */
5384 if (TYPE_MODE (TREE_TYPE (decl_result)) != BLKmode
5385 && REG_P (real_decl_rtl)
5386 && targetm.calls.return_in_msb (TREE_TYPE (decl_result)))
5387 {
5388 emit_move_insn (gen_rtx_REG (GET_MODE (decl_rtl),
5389 REGNO (real_decl_rtl)),
5390 decl_rtl);
5391 shift_return_value (GET_MODE (decl_rtl), true, real_decl_rtl);
5392 }
5393 else if (GET_CODE (real_decl_rtl) == PARALLEL)
5394 {
5395 /* If expand_function_start has created a PARALLEL for decl_rtl,
5396 move the result to the real return registers. Otherwise, do
5397 a group load from decl_rtl for a named return. */
5398 if (GET_CODE (decl_rtl) == PARALLEL)
5399 emit_group_move (real_decl_rtl, decl_rtl);
5400 else
5401 emit_group_load (real_decl_rtl, decl_rtl,
5402 TREE_TYPE (decl_result),
5403 int_size_in_bytes (TREE_TYPE (decl_result)));
5404 }
5405 /* In the case of complex integer modes smaller than a word, we'll
5406 need to generate some non-trivial bitfield insertions. Do that
5407 on a pseudo and not the hard register. */
5408 else if (GET_CODE (decl_rtl) == CONCAT
5409 && is_complex_int_mode (GET_MODE (decl_rtl), &cmode)
5410 && GET_MODE_BITSIZE (cmode) <= BITS_PER_WORD)
5411 {
5412 int old_generating_concat_p;
5413 rtx tmp;
5414
5415 old_generating_concat_p = generating_concat_p;
5416 generating_concat_p = 0;
5417 tmp = gen_reg_rtx (GET_MODE (decl_rtl));
5418 generating_concat_p = old_generating_concat_p;
5419
5420 emit_move_insn (tmp, decl_rtl);
5421 emit_move_insn (real_decl_rtl, tmp);
5422 }
5423 /* If a named return value dumped decl_return to memory, then
5424 we may need to re-do the PROMOTE_MODE signed/unsigned
5425 extension. */
5426 else if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
5427 {
5428 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
5429 promote_function_mode (TREE_TYPE (decl_result),
5430 GET_MODE (decl_rtl), &unsignedp,
5431 TREE_TYPE (current_function_decl), 1);
5432
5433 convert_move (real_decl_rtl, decl_rtl, unsignedp);
5434 }
5435 else
5436 emit_move_insn (real_decl_rtl, decl_rtl);
5437 }
5438 }
5439
5440 /* If returning a structure, arrange to return the address of the value
5441 in a place where debuggers expect to find it.
5442
5443 If returning a structure PCC style,
5444 the caller also depends on this value.
5445 And cfun->returns_pcc_struct is not necessarily set. */
5446 if ((cfun->returns_struct || cfun->returns_pcc_struct)
5447 && !targetm.calls.omit_struct_return_reg)
5448 {
5449 rtx value_address = DECL_RTL (DECL_RESULT (current_function_decl));
5450 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
5451 rtx outgoing;
5452
5453 if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
5454 type = TREE_TYPE (type);
5455 else
5456 value_address = XEXP (value_address, 0);
5457
5458 outgoing = targetm.calls.function_value (build_pointer_type (type),
5459 current_function_decl, true);
5460
5461 /* Mark this as a function return value so integrate will delete the
5462 assignment and USE below when inlining this function. */
5463 REG_FUNCTION_VALUE_P (outgoing) = 1;
5464
5465 /* The address may be ptr_mode and OUTGOING may be Pmode. */
5466 scalar_int_mode mode = as_a <scalar_int_mode> (GET_MODE (outgoing));
5467 value_address = convert_memory_address (mode, value_address);
5468
5469 emit_move_insn (outgoing, value_address);
5470
5471 /* Show return register used to hold result (in this case the address
5472 of the result. */
5473 crtl->return_rtx = outgoing;
5474 }
5475
5476 /* Emit the actual code to clobber return register. Don't emit
5477 it if clobber_after is a barrier, then the previous basic block
5478 certainly doesn't fall thru into the exit block. */
5479 if (!BARRIER_P (clobber_after))
5480 {
5481 start_sequence ();
5482 clobber_return_register ();
5483 rtx_insn *seq = get_insns ();
5484 end_sequence ();
5485
5486 emit_insn_after (seq, clobber_after);
5487 }
5488
5489 /* Output the label for the naked return from the function. */
5490 if (naked_return_label)
5491 emit_label (naked_return_label);
5492
5493 /* @@@ This is a kludge. We want to ensure that instructions that
5494 may trap are not moved into the epilogue by scheduling, because
5495 we don't always emit unwind information for the epilogue. */
5496 if (cfun->can_throw_non_call_exceptions
5497 && targetm_common.except_unwind_info (&global_options) != UI_SJLJ)
5498 emit_insn (gen_blockage ());
5499
5500 /* If stack protection is enabled for this function, check the guard. */
5501 if (crtl->stack_protect_guard
5502 && targetm.stack_protect_runtime_enabled_p ()
5503 && naked_return_label)
5504 stack_protect_epilogue ();
5505
5506 /* If we had calls to alloca, and this machine needs
5507 an accurate stack pointer to exit the function,
5508 insert some code to save and restore the stack pointer. */
5509 if (! EXIT_IGNORE_STACK
5510 && cfun->calls_alloca)
5511 {
5512 rtx tem = 0;
5513
5514 start_sequence ();
5515 emit_stack_save (SAVE_FUNCTION, &tem);
5516 rtx_insn *seq = get_insns ();
5517 end_sequence ();
5518 emit_insn_before (seq, parm_birth_insn);
5519
5520 emit_stack_restore (SAVE_FUNCTION, tem);
5521 }
5522
5523 /* ??? This should no longer be necessary since stupid is no longer with
5524 us, but there are some parts of the compiler (eg reload_combine, and
5525 sh mach_dep_reorg) that still try and compute their own lifetime info
5526 instead of using the general framework. */
5527 use_return_register ();
5528 }
5529
5530 rtx
5531 get_arg_pointer_save_area (void)
5532 {
5533 rtx ret = arg_pointer_save_area;
5534
5535 if (! ret)
5536 {
5537 ret = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
5538 arg_pointer_save_area = ret;
5539 }
5540
5541 if (! crtl->arg_pointer_save_area_init)
5542 {
5543 /* Save the arg pointer at the beginning of the function. The
5544 generated stack slot may not be a valid memory address, so we
5545 have to check it and fix it if necessary. */
5546 start_sequence ();
5547 emit_move_insn (validize_mem (copy_rtx (ret)),
5548 crtl->args.internal_arg_pointer);
5549 rtx_insn *seq = get_insns ();
5550 end_sequence ();
5551
5552 push_topmost_sequence ();
5553 emit_insn_after (seq, entry_of_function ());
5554 pop_topmost_sequence ();
5555
5556 crtl->arg_pointer_save_area_init = true;
5557 }
5558
5559 return ret;
5560 }
5561 \f
5562
5563 /* If debugging dumps are requested, dump information about how the
5564 target handled -fstack-check=clash for the prologue.
5565
5566 PROBES describes what if any probes were emitted.
5567
5568 RESIDUALS indicates if the prologue had any residual allocation
5569 (i.e. total allocation was not a multiple of PROBE_INTERVAL). */
5570
5571 void
5572 dump_stack_clash_frame_info (enum stack_clash_probes probes, bool residuals)
5573 {
5574 if (!dump_file)
5575 return;
5576
5577 switch (probes)
5578 {
5579 case NO_PROBE_NO_FRAME:
5580 fprintf (dump_file,
5581 "Stack clash no probe no stack adjustment in prologue.\n");
5582 break;
5583 case NO_PROBE_SMALL_FRAME:
5584 fprintf (dump_file,
5585 "Stack clash no probe small stack adjustment in prologue.\n");
5586 break;
5587 case PROBE_INLINE:
5588 fprintf (dump_file, "Stack clash inline probes in prologue.\n");
5589 break;
5590 case PROBE_LOOP:
5591 fprintf (dump_file, "Stack clash probe loop in prologue.\n");
5592 break;
5593 }
5594
5595 if (residuals)
5596 fprintf (dump_file, "Stack clash residual allocation in prologue.\n");
5597 else
5598 fprintf (dump_file, "Stack clash no residual allocation in prologue.\n");
5599
5600 if (frame_pointer_needed)
5601 fprintf (dump_file, "Stack clash frame pointer needed.\n");
5602 else
5603 fprintf (dump_file, "Stack clash no frame pointer needed.\n");
5604
5605 if (TREE_THIS_VOLATILE (cfun->decl))
5606 fprintf (dump_file,
5607 "Stack clash noreturn prologue, assuming no implicit"
5608 " probes in caller.\n");
5609 else
5610 fprintf (dump_file,
5611 "Stack clash not noreturn prologue.\n");
5612 }
5613
5614 /* Add a list of INSNS to the hash HASHP, possibly allocating HASHP
5615 for the first time. */
5616
5617 static void
5618 record_insns (rtx_insn *insns, rtx end, hash_table<insn_cache_hasher> **hashp)
5619 {
5620 rtx_insn *tmp;
5621 hash_table<insn_cache_hasher> *hash = *hashp;
5622
5623 if (hash == NULL)
5624 *hashp = hash = hash_table<insn_cache_hasher>::create_ggc (17);
5625
5626 for (tmp = insns; tmp != end; tmp = NEXT_INSN (tmp))
5627 {
5628 rtx *slot = hash->find_slot (tmp, INSERT);
5629 gcc_assert (*slot == NULL);
5630 *slot = tmp;
5631 }
5632 }
5633
5634 /* INSN has been duplicated or replaced by as COPY, perhaps by duplicating a
5635 basic block, splitting or peepholes. If INSN is a prologue or epilogue
5636 insn, then record COPY as well. */
5637
5638 void
5639 maybe_copy_prologue_epilogue_insn (rtx insn, rtx copy)
5640 {
5641 hash_table<insn_cache_hasher> *hash;
5642 rtx *slot;
5643
5644 hash = epilogue_insn_hash;
5645 if (!hash || !hash->find (insn))
5646 {
5647 hash = prologue_insn_hash;
5648 if (!hash || !hash->find (insn))
5649 return;
5650 }
5651
5652 slot = hash->find_slot (copy, INSERT);
5653 gcc_assert (*slot == NULL);
5654 *slot = copy;
5655 }
5656
5657 /* Determine if any INSNs in HASH are, or are part of, INSN. Because
5658 we can be running after reorg, SEQUENCE rtl is possible. */
5659
5660 static bool
5661 contains (const rtx_insn *insn, hash_table<insn_cache_hasher> *hash)
5662 {
5663 if (hash == NULL)
5664 return false;
5665
5666 if (NONJUMP_INSN_P (insn) && GET_CODE (PATTERN (insn)) == SEQUENCE)
5667 {
5668 rtx_sequence *seq = as_a <rtx_sequence *> (PATTERN (insn));
5669 int i;
5670 for (i = seq->len () - 1; i >= 0; i--)
5671 if (hash->find (seq->element (i)))
5672 return true;
5673 return false;
5674 }
5675
5676 return hash->find (const_cast<rtx_insn *> (insn)) != NULL;
5677 }
5678
5679 int
5680 prologue_contains (const rtx_insn *insn)
5681 {
5682 return contains (insn, prologue_insn_hash);
5683 }
5684
5685 int
5686 epilogue_contains (const rtx_insn *insn)
5687 {
5688 return contains (insn, epilogue_insn_hash);
5689 }
5690
5691 int
5692 prologue_epilogue_contains (const rtx_insn *insn)
5693 {
5694 if (contains (insn, prologue_insn_hash))
5695 return 1;
5696 if (contains (insn, epilogue_insn_hash))
5697 return 1;
5698 return 0;
5699 }
5700
5701 void
5702 record_prologue_seq (rtx_insn *seq)
5703 {
5704 record_insns (seq, NULL, &prologue_insn_hash);
5705 }
5706
5707 void
5708 record_epilogue_seq (rtx_insn *seq)
5709 {
5710 record_insns (seq, NULL, &epilogue_insn_hash);
5711 }
5712
5713 /* Set JUMP_LABEL for a return insn. */
5714
5715 void
5716 set_return_jump_label (rtx_insn *returnjump)
5717 {
5718 rtx pat = PATTERN (returnjump);
5719 if (GET_CODE (pat) == PARALLEL)
5720 pat = XVECEXP (pat, 0, 0);
5721 if (ANY_RETURN_P (pat))
5722 JUMP_LABEL (returnjump) = pat;
5723 else
5724 JUMP_LABEL (returnjump) = ret_rtx;
5725 }
5726
5727 /* Return a sequence to be used as the split prologue for the current
5728 function, or NULL. */
5729
5730 static rtx_insn *
5731 make_split_prologue_seq (void)
5732 {
5733 if (!flag_split_stack
5734 || lookup_attribute ("no_split_stack", DECL_ATTRIBUTES (cfun->decl)))
5735 return NULL;
5736
5737 start_sequence ();
5738 emit_insn (targetm.gen_split_stack_prologue ());
5739 rtx_insn *seq = get_insns ();
5740 end_sequence ();
5741
5742 record_insns (seq, NULL, &prologue_insn_hash);
5743 set_insn_locations (seq, prologue_location);
5744
5745 return seq;
5746 }
5747
5748 /* Return a sequence to be used as the prologue for the current function,
5749 or NULL. */
5750
5751 static rtx_insn *
5752 make_prologue_seq (void)
5753 {
5754 if (!targetm.have_prologue ())
5755 return NULL;
5756
5757 start_sequence ();
5758 rtx_insn *seq = targetm.gen_prologue ();
5759 emit_insn (seq);
5760
5761 /* Insert an explicit USE for the frame pointer
5762 if the profiling is on and the frame pointer is required. */
5763 if (crtl->profile && frame_pointer_needed)
5764 emit_use (hard_frame_pointer_rtx);
5765
5766 /* Retain a map of the prologue insns. */
5767 record_insns (seq, NULL, &prologue_insn_hash);
5768 emit_note (NOTE_INSN_PROLOGUE_END);
5769
5770 /* Ensure that instructions are not moved into the prologue when
5771 profiling is on. The call to the profiling routine can be
5772 emitted within the live range of a call-clobbered register. */
5773 if (!targetm.profile_before_prologue () && crtl->profile)
5774 emit_insn (gen_blockage ());
5775
5776 seq = get_insns ();
5777 end_sequence ();
5778 set_insn_locations (seq, prologue_location);
5779
5780 return seq;
5781 }
5782
5783 /* Return a sequence to be used as the epilogue for the current function,
5784 or NULL. */
5785
5786 static rtx_insn *
5787 make_epilogue_seq (void)
5788 {
5789 if (!targetm.have_epilogue ())
5790 return NULL;
5791
5792 start_sequence ();
5793 emit_note (NOTE_INSN_EPILOGUE_BEG);
5794 rtx_insn *seq = targetm.gen_epilogue ();
5795 if (seq)
5796 emit_jump_insn (seq);
5797
5798 /* Retain a map of the epilogue insns. */
5799 record_insns (seq, NULL, &epilogue_insn_hash);
5800 set_insn_locations (seq, epilogue_location);
5801
5802 seq = get_insns ();
5803 rtx_insn *returnjump = get_last_insn ();
5804 end_sequence ();
5805
5806 if (JUMP_P (returnjump))
5807 set_return_jump_label (returnjump);
5808
5809 return seq;
5810 }
5811
5812
5813 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
5814 this into place with notes indicating where the prologue ends and where
5815 the epilogue begins. Update the basic block information when possible.
5816
5817 Notes on epilogue placement:
5818 There are several kinds of edges to the exit block:
5819 * a single fallthru edge from LAST_BB
5820 * possibly, edges from blocks containing sibcalls
5821 * possibly, fake edges from infinite loops
5822
5823 The epilogue is always emitted on the fallthru edge from the last basic
5824 block in the function, LAST_BB, into the exit block.
5825
5826 If LAST_BB is empty except for a label, it is the target of every
5827 other basic block in the function that ends in a return. If a
5828 target has a return or simple_return pattern (possibly with
5829 conditional variants), these basic blocks can be changed so that a
5830 return insn is emitted into them, and their target is adjusted to
5831 the real exit block.
5832
5833 Notes on shrink wrapping: We implement a fairly conservative
5834 version of shrink-wrapping rather than the textbook one. We only
5835 generate a single prologue and a single epilogue. This is
5836 sufficient to catch a number of interesting cases involving early
5837 exits.
5838
5839 First, we identify the blocks that require the prologue to occur before
5840 them. These are the ones that modify a call-saved register, or reference
5841 any of the stack or frame pointer registers. To simplify things, we then
5842 mark everything reachable from these blocks as also requiring a prologue.
5843 This takes care of loops automatically, and avoids the need to examine
5844 whether MEMs reference the frame, since it is sufficient to check for
5845 occurrences of the stack or frame pointer.
5846
5847 We then compute the set of blocks for which the need for a prologue
5848 is anticipatable (borrowing terminology from the shrink-wrapping
5849 description in Muchnick's book). These are the blocks which either
5850 require a prologue themselves, or those that have only successors
5851 where the prologue is anticipatable. The prologue needs to be
5852 inserted on all edges from BB1->BB2 where BB2 is in ANTIC and BB1
5853 is not. For the moment, we ensure that only one such edge exists.
5854
5855 The epilogue is placed as described above, but we make a
5856 distinction between inserting return and simple_return patterns
5857 when modifying other blocks that end in a return. Blocks that end
5858 in a sibcall omit the sibcall_epilogue if the block is not in
5859 ANTIC. */
5860
5861 void
5862 thread_prologue_and_epilogue_insns (void)
5863 {
5864 df_analyze ();
5865
5866 /* Can't deal with multiple successors of the entry block at the
5867 moment. Function should always have at least one entry
5868 point. */
5869 gcc_assert (single_succ_p (ENTRY_BLOCK_PTR_FOR_FN (cfun)));
5870
5871 edge entry_edge = single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun));
5872 edge orig_entry_edge = entry_edge;
5873
5874 rtx_insn *split_prologue_seq = make_split_prologue_seq ();
5875 rtx_insn *prologue_seq = make_prologue_seq ();
5876 rtx_insn *epilogue_seq = make_epilogue_seq ();
5877
5878 /* Try to perform a kind of shrink-wrapping, making sure the
5879 prologue/epilogue is emitted only around those parts of the
5880 function that require it. */
5881 try_shrink_wrapping (&entry_edge, prologue_seq);
5882
5883 /* If the target can handle splitting the prologue/epilogue into separate
5884 components, try to shrink-wrap these components separately. */
5885 try_shrink_wrapping_separate (entry_edge->dest);
5886
5887 /* If that did anything for any component we now need the generate the
5888 "main" prologue again. Because some targets require some of these
5889 to be called in a specific order (i386 requires the split prologue
5890 to be first, for example), we create all three sequences again here.
5891 If this does not work for some target, that target should not enable
5892 separate shrink-wrapping. */
5893 if (crtl->shrink_wrapped_separate)
5894 {
5895 split_prologue_seq = make_split_prologue_seq ();
5896 prologue_seq = make_prologue_seq ();
5897 epilogue_seq = make_epilogue_seq ();
5898 }
5899
5900 rtl_profile_for_bb (EXIT_BLOCK_PTR_FOR_FN (cfun));
5901
5902 /* A small fib -- epilogue is not yet completed, but we wish to re-use
5903 this marker for the splits of EH_RETURN patterns, and nothing else
5904 uses the flag in the meantime. */
5905 epilogue_completed = 1;
5906
5907 /* Find non-fallthru edges that end with EH_RETURN instructions. On
5908 some targets, these get split to a special version of the epilogue
5909 code. In order to be able to properly annotate these with unwind
5910 info, try to split them now. If we get a valid split, drop an
5911 EPILOGUE_BEG note and mark the insns as epilogue insns. */
5912 edge e;
5913 edge_iterator ei;
5914 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
5915 {
5916 rtx_insn *prev, *last, *trial;
5917
5918 if (e->flags & EDGE_FALLTHRU)
5919 continue;
5920 last = BB_END (e->src);
5921 if (!eh_returnjump_p (last))
5922 continue;
5923
5924 prev = PREV_INSN (last);
5925 trial = try_split (PATTERN (last), last, 1);
5926 if (trial == last)
5927 continue;
5928
5929 record_insns (NEXT_INSN (prev), NEXT_INSN (trial), &epilogue_insn_hash);
5930 emit_note_after (NOTE_INSN_EPILOGUE_BEG, prev);
5931 }
5932
5933 edge exit_fallthru_edge = find_fallthru_edge (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds);
5934
5935 if (exit_fallthru_edge)
5936 {
5937 if (epilogue_seq)
5938 {
5939 insert_insn_on_edge (epilogue_seq, exit_fallthru_edge);
5940 commit_edge_insertions ();
5941
5942 /* The epilogue insns we inserted may cause the exit edge to no longer
5943 be fallthru. */
5944 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
5945 {
5946 if (((e->flags & EDGE_FALLTHRU) != 0)
5947 && returnjump_p (BB_END (e->src)))
5948 e->flags &= ~EDGE_FALLTHRU;
5949 }
5950 }
5951 else if (next_active_insn (BB_END (exit_fallthru_edge->src)))
5952 {
5953 /* We have a fall-through edge to the exit block, the source is not
5954 at the end of the function, and there will be an assembler epilogue
5955 at the end of the function.
5956 We can't use force_nonfallthru here, because that would try to
5957 use return. Inserting a jump 'by hand' is extremely messy, so
5958 we take advantage of cfg_layout_finalize using
5959 fixup_fallthru_exit_predecessor. */
5960 cfg_layout_initialize (0);
5961 basic_block cur_bb;
5962 FOR_EACH_BB_FN (cur_bb, cfun)
5963 if (cur_bb->index >= NUM_FIXED_BLOCKS
5964 && cur_bb->next_bb->index >= NUM_FIXED_BLOCKS)
5965 cur_bb->aux = cur_bb->next_bb;
5966 cfg_layout_finalize ();
5967 }
5968 }
5969
5970 /* Insert the prologue. */
5971
5972 rtl_profile_for_bb (ENTRY_BLOCK_PTR_FOR_FN (cfun));
5973
5974 if (split_prologue_seq || prologue_seq)
5975 {
5976 rtx_insn *split_prologue_insn = split_prologue_seq;
5977 if (split_prologue_seq)
5978 {
5979 while (split_prologue_insn && !NONDEBUG_INSN_P (split_prologue_insn))
5980 split_prologue_insn = NEXT_INSN (split_prologue_insn);
5981 insert_insn_on_edge (split_prologue_seq, orig_entry_edge);
5982 }
5983
5984 rtx_insn *prologue_insn = prologue_seq;
5985 if (prologue_seq)
5986 {
5987 while (prologue_insn && !NONDEBUG_INSN_P (prologue_insn))
5988 prologue_insn = NEXT_INSN (prologue_insn);
5989 insert_insn_on_edge (prologue_seq, entry_edge);
5990 }
5991
5992 commit_edge_insertions ();
5993
5994 /* Look for basic blocks within the prologue insns. */
5995 if (split_prologue_insn
5996 && BLOCK_FOR_INSN (split_prologue_insn) == NULL)
5997 split_prologue_insn = NULL;
5998 if (prologue_insn
5999 && BLOCK_FOR_INSN (prologue_insn) == NULL)
6000 prologue_insn = NULL;
6001 if (split_prologue_insn || prologue_insn)
6002 {
6003 auto_sbitmap blocks (last_basic_block_for_fn (cfun));
6004 bitmap_clear (blocks);
6005 if (split_prologue_insn)
6006 bitmap_set_bit (blocks,
6007 BLOCK_FOR_INSN (split_prologue_insn)->index);
6008 if (prologue_insn)
6009 bitmap_set_bit (blocks, BLOCK_FOR_INSN (prologue_insn)->index);
6010 find_many_sub_basic_blocks (blocks);
6011 }
6012 }
6013
6014 default_rtl_profile ();
6015
6016 /* Emit sibling epilogues before any sibling call sites. */
6017 for (ei = ei_start (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds);
6018 (e = ei_safe_edge (ei));
6019 ei_next (&ei))
6020 {
6021 /* Skip those already handled, the ones that run without prologue. */
6022 if (e->flags & EDGE_IGNORE)
6023 {
6024 e->flags &= ~EDGE_IGNORE;
6025 continue;
6026 }
6027
6028 rtx_insn *insn = BB_END (e->src);
6029
6030 if (!(CALL_P (insn) && SIBLING_CALL_P (insn)))
6031 continue;
6032
6033 if (rtx_insn *ep_seq = targetm.gen_sibcall_epilogue ())
6034 {
6035 start_sequence ();
6036 emit_note (NOTE_INSN_EPILOGUE_BEG);
6037 emit_insn (ep_seq);
6038 rtx_insn *seq = get_insns ();
6039 end_sequence ();
6040
6041 /* Retain a map of the epilogue insns. Used in life analysis to
6042 avoid getting rid of sibcall epilogue insns. Do this before we
6043 actually emit the sequence. */
6044 record_insns (seq, NULL, &epilogue_insn_hash);
6045 set_insn_locations (seq, epilogue_location);
6046
6047 emit_insn_before (seq, insn);
6048 }
6049 }
6050
6051 if (epilogue_seq)
6052 {
6053 rtx_insn *insn, *next;
6054
6055 /* Similarly, move any line notes that appear after the epilogue.
6056 There is no need, however, to be quite so anal about the existence
6057 of such a note. Also possibly move
6058 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
6059 info generation. */
6060 for (insn = epilogue_seq; insn; insn = next)
6061 {
6062 next = NEXT_INSN (insn);
6063 if (NOTE_P (insn)
6064 && (NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG))
6065 reorder_insns (insn, insn, PREV_INSN (epilogue_seq));
6066 }
6067 }
6068
6069 /* Threading the prologue and epilogue changes the artificial refs
6070 in the entry and exit blocks. */
6071 epilogue_completed = 1;
6072 df_update_entry_exit_and_calls ();
6073 }
6074
6075 /* Reposition the prologue-end and epilogue-begin notes after
6076 instruction scheduling. */
6077
6078 void
6079 reposition_prologue_and_epilogue_notes (void)
6080 {
6081 if (!targetm.have_prologue ()
6082 && !targetm.have_epilogue ()
6083 && !targetm.have_sibcall_epilogue ())
6084 return;
6085
6086 /* Since the hash table is created on demand, the fact that it is
6087 non-null is a signal that it is non-empty. */
6088 if (prologue_insn_hash != NULL)
6089 {
6090 size_t len = prologue_insn_hash->elements ();
6091 rtx_insn *insn, *last = NULL, *note = NULL;
6092
6093 /* Scan from the beginning until we reach the last prologue insn. */
6094 /* ??? While we do have the CFG intact, there are two problems:
6095 (1) The prologue can contain loops (typically probing the stack),
6096 which means that the end of the prologue isn't in the first bb.
6097 (2) Sometimes the PROLOGUE_END note gets pushed into the next bb. */
6098 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
6099 {
6100 if (NOTE_P (insn))
6101 {
6102 if (NOTE_KIND (insn) == NOTE_INSN_PROLOGUE_END)
6103 note = insn;
6104 }
6105 else if (contains (insn, prologue_insn_hash))
6106 {
6107 last = insn;
6108 if (--len == 0)
6109 break;
6110 }
6111 }
6112
6113 if (last)
6114 {
6115 if (note == NULL)
6116 {
6117 /* Scan forward looking for the PROLOGUE_END note. It should
6118 be right at the beginning of the block, possibly with other
6119 insn notes that got moved there. */
6120 for (note = NEXT_INSN (last); ; note = NEXT_INSN (note))
6121 {
6122 if (NOTE_P (note)
6123 && NOTE_KIND (note) == NOTE_INSN_PROLOGUE_END)
6124 break;
6125 }
6126 }
6127
6128 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
6129 if (LABEL_P (last))
6130 last = NEXT_INSN (last);
6131 reorder_insns (note, note, last);
6132 }
6133 }
6134
6135 if (epilogue_insn_hash != NULL)
6136 {
6137 edge_iterator ei;
6138 edge e;
6139
6140 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
6141 {
6142 rtx_insn *insn, *first = NULL, *note = NULL;
6143 basic_block bb = e->src;
6144
6145 /* Scan from the beginning until we reach the first epilogue insn. */
6146 FOR_BB_INSNS (bb, insn)
6147 {
6148 if (NOTE_P (insn))
6149 {
6150 if (NOTE_KIND (insn) == NOTE_INSN_EPILOGUE_BEG)
6151 {
6152 note = insn;
6153 if (first != NULL)
6154 break;
6155 }
6156 }
6157 else if (first == NULL && contains (insn, epilogue_insn_hash))
6158 {
6159 first = insn;
6160 if (note != NULL)
6161 break;
6162 }
6163 }
6164
6165 if (note)
6166 {
6167 /* If the function has a single basic block, and no real
6168 epilogue insns (e.g. sibcall with no cleanup), the
6169 epilogue note can get scheduled before the prologue
6170 note. If we have frame related prologue insns, having
6171 them scanned during the epilogue will result in a crash.
6172 In this case re-order the epilogue note to just before
6173 the last insn in the block. */
6174 if (first == NULL)
6175 first = BB_END (bb);
6176
6177 if (PREV_INSN (first) != note)
6178 reorder_insns (note, note, PREV_INSN (first));
6179 }
6180 }
6181 }
6182 }
6183
6184 /* Returns the name of function declared by FNDECL. */
6185 const char *
6186 fndecl_name (tree fndecl)
6187 {
6188 if (fndecl == NULL)
6189 return "(nofn)";
6190 return lang_hooks.decl_printable_name (fndecl, 1);
6191 }
6192
6193 /* Returns the name of function FN. */
6194 const char *
6195 function_name (struct function *fn)
6196 {
6197 tree fndecl = (fn == NULL) ? NULL : fn->decl;
6198 return fndecl_name (fndecl);
6199 }
6200
6201 /* Returns the name of the current function. */
6202 const char *
6203 current_function_name (void)
6204 {
6205 return function_name (cfun);
6206 }
6207 \f
6208
6209 static unsigned int
6210 rest_of_handle_check_leaf_regs (void)
6211 {
6212 #ifdef LEAF_REGISTERS
6213 crtl->uses_only_leaf_regs
6214 = optimize > 0 && only_leaf_regs_used () && leaf_function_p ();
6215 #endif
6216 return 0;
6217 }
6218
6219 /* Insert a TYPE into the used types hash table of CFUN. */
6220
6221 static void
6222 used_types_insert_helper (tree type, struct function *func)
6223 {
6224 if (type != NULL && func != NULL)
6225 {
6226 if (func->used_types_hash == NULL)
6227 func->used_types_hash = hash_set<tree>::create_ggc (37);
6228
6229 func->used_types_hash->add (type);
6230 }
6231 }
6232
6233 /* Given a type, insert it into the used hash table in cfun. */
6234 void
6235 used_types_insert (tree t)
6236 {
6237 while (POINTER_TYPE_P (t) || TREE_CODE (t) == ARRAY_TYPE)
6238 if (TYPE_NAME (t))
6239 break;
6240 else
6241 t = TREE_TYPE (t);
6242 if (TREE_CODE (t) == ERROR_MARK)
6243 return;
6244 if (TYPE_NAME (t) == NULL_TREE
6245 || TYPE_NAME (t) == TYPE_NAME (TYPE_MAIN_VARIANT (t)))
6246 t = TYPE_MAIN_VARIANT (t);
6247 if (debug_info_level > DINFO_LEVEL_NONE)
6248 {
6249 if (cfun)
6250 used_types_insert_helper (t, cfun);
6251 else
6252 {
6253 /* So this might be a type referenced by a global variable.
6254 Record that type so that we can later decide to emit its
6255 debug information. */
6256 vec_safe_push (types_used_by_cur_var_decl, t);
6257 }
6258 }
6259 }
6260
6261 /* Helper to Hash a struct types_used_by_vars_entry. */
6262
6263 static hashval_t
6264 hash_types_used_by_vars_entry (const struct types_used_by_vars_entry *entry)
6265 {
6266 gcc_assert (entry && entry->var_decl && entry->type);
6267
6268 return iterative_hash_object (entry->type,
6269 iterative_hash_object (entry->var_decl, 0));
6270 }
6271
6272 /* Hash function of the types_used_by_vars_entry hash table. */
6273
6274 hashval_t
6275 used_type_hasher::hash (types_used_by_vars_entry *entry)
6276 {
6277 return hash_types_used_by_vars_entry (entry);
6278 }
6279
6280 /*Equality function of the types_used_by_vars_entry hash table. */
6281
6282 bool
6283 used_type_hasher::equal (types_used_by_vars_entry *e1,
6284 types_used_by_vars_entry *e2)
6285 {
6286 return (e1->var_decl == e2->var_decl && e1->type == e2->type);
6287 }
6288
6289 /* Inserts an entry into the types_used_by_vars_hash hash table. */
6290
6291 void
6292 types_used_by_var_decl_insert (tree type, tree var_decl)
6293 {
6294 if (type != NULL && var_decl != NULL)
6295 {
6296 types_used_by_vars_entry **slot;
6297 struct types_used_by_vars_entry e;
6298 e.var_decl = var_decl;
6299 e.type = type;
6300 if (types_used_by_vars_hash == NULL)
6301 types_used_by_vars_hash
6302 = hash_table<used_type_hasher>::create_ggc (37);
6303
6304 slot = types_used_by_vars_hash->find_slot (&e, INSERT);
6305 if (*slot == NULL)
6306 {
6307 struct types_used_by_vars_entry *entry;
6308 entry = ggc_alloc<types_used_by_vars_entry> ();
6309 entry->type = type;
6310 entry->var_decl = var_decl;
6311 *slot = entry;
6312 }
6313 }
6314 }
6315
6316 namespace {
6317
6318 const pass_data pass_data_leaf_regs =
6319 {
6320 RTL_PASS, /* type */
6321 "*leaf_regs", /* name */
6322 OPTGROUP_NONE, /* optinfo_flags */
6323 TV_NONE, /* tv_id */
6324 0, /* properties_required */
6325 0, /* properties_provided */
6326 0, /* properties_destroyed */
6327 0, /* todo_flags_start */
6328 0, /* todo_flags_finish */
6329 };
6330
6331 class pass_leaf_regs : public rtl_opt_pass
6332 {
6333 public:
6334 pass_leaf_regs (gcc::context *ctxt)
6335 : rtl_opt_pass (pass_data_leaf_regs, ctxt)
6336 {}
6337
6338 /* opt_pass methods: */
6339 virtual unsigned int execute (function *)
6340 {
6341 return rest_of_handle_check_leaf_regs ();
6342 }
6343
6344 }; // class pass_leaf_regs
6345
6346 } // anon namespace
6347
6348 rtl_opt_pass *
6349 make_pass_leaf_regs (gcc::context *ctxt)
6350 {
6351 return new pass_leaf_regs (ctxt);
6352 }
6353
6354 static unsigned int
6355 rest_of_handle_thread_prologue_and_epilogue (void)
6356 {
6357 /* prepare_shrink_wrap is sensitive to the block structure of the control
6358 flow graph, so clean it up first. */
6359 if (optimize)
6360 cleanup_cfg (0);
6361
6362 /* On some machines, the prologue and epilogue code, or parts thereof,
6363 can be represented as RTL. Doing so lets us schedule insns between
6364 it and the rest of the code and also allows delayed branch
6365 scheduling to operate in the epilogue. */
6366 thread_prologue_and_epilogue_insns ();
6367
6368 /* Some non-cold blocks may now be only reachable from cold blocks.
6369 Fix that up. */
6370 fixup_partitions ();
6371
6372 /* Shrink-wrapping can result in unreachable edges in the epilogue,
6373 see PR57320. */
6374 cleanup_cfg (optimize ? CLEANUP_EXPENSIVE : 0);
6375
6376 /* The stack usage info is finalized during prologue expansion. */
6377 if (flag_stack_usage_info)
6378 output_stack_usage ();
6379
6380 return 0;
6381 }
6382
6383 namespace {
6384
6385 const pass_data pass_data_thread_prologue_and_epilogue =
6386 {
6387 RTL_PASS, /* type */
6388 "pro_and_epilogue", /* name */
6389 OPTGROUP_NONE, /* optinfo_flags */
6390 TV_THREAD_PROLOGUE_AND_EPILOGUE, /* tv_id */
6391 0, /* properties_required */
6392 0, /* properties_provided */
6393 0, /* properties_destroyed */
6394 0, /* todo_flags_start */
6395 ( TODO_df_verify | TODO_df_finish ), /* todo_flags_finish */
6396 };
6397
6398 class pass_thread_prologue_and_epilogue : public rtl_opt_pass
6399 {
6400 public:
6401 pass_thread_prologue_and_epilogue (gcc::context *ctxt)
6402 : rtl_opt_pass (pass_data_thread_prologue_and_epilogue, ctxt)
6403 {}
6404
6405 /* opt_pass methods: */
6406 virtual unsigned int execute (function *)
6407 {
6408 return rest_of_handle_thread_prologue_and_epilogue ();
6409 }
6410
6411 }; // class pass_thread_prologue_and_epilogue
6412
6413 } // anon namespace
6414
6415 rtl_opt_pass *
6416 make_pass_thread_prologue_and_epilogue (gcc::context *ctxt)
6417 {
6418 return new pass_thread_prologue_and_epilogue (ctxt);
6419 }
6420 \f
6421
6422 /* If CONSTRAINT is a matching constraint, then return its number.
6423 Otherwise, return -1. */
6424
6425 static int
6426 matching_constraint_num (const char *constraint)
6427 {
6428 if (*constraint == '%')
6429 constraint++;
6430
6431 if (IN_RANGE (*constraint, '0', '9'))
6432 return strtoul (constraint, NULL, 10);
6433
6434 return -1;
6435 }
6436
6437 /* This mini-pass fixes fall-out from SSA in asm statements that have
6438 in-out constraints. Say you start with
6439
6440 orig = inout;
6441 asm ("": "+mr" (inout));
6442 use (orig);
6443
6444 which is transformed very early to use explicit output and match operands:
6445
6446 orig = inout;
6447 asm ("": "=mr" (inout) : "0" (inout));
6448 use (orig);
6449
6450 Or, after SSA and copyprop,
6451
6452 asm ("": "=mr" (inout_2) : "0" (inout_1));
6453 use (inout_1);
6454
6455 Clearly inout_2 and inout_1 can't be coalesced easily anymore, as
6456 they represent two separate values, so they will get different pseudo
6457 registers during expansion. Then, since the two operands need to match
6458 per the constraints, but use different pseudo registers, reload can
6459 only register a reload for these operands. But reloads can only be
6460 satisfied by hardregs, not by memory, so we need a register for this
6461 reload, just because we are presented with non-matching operands.
6462 So, even though we allow memory for this operand, no memory can be
6463 used for it, just because the two operands don't match. This can
6464 cause reload failures on register-starved targets.
6465
6466 So it's a symptom of reload not being able to use memory for reloads
6467 or, alternatively it's also a symptom of both operands not coming into
6468 reload as matching (in which case the pseudo could go to memory just
6469 fine, as the alternative allows it, and no reload would be necessary).
6470 We fix the latter problem here, by transforming
6471
6472 asm ("": "=mr" (inout_2) : "0" (inout_1));
6473
6474 back to
6475
6476 inout_2 = inout_1;
6477 asm ("": "=mr" (inout_2) : "0" (inout_2)); */
6478
6479 static void
6480 match_asm_constraints_1 (rtx_insn *insn, rtx *p_sets, int noutputs)
6481 {
6482 int i;
6483 bool changed = false;
6484 rtx op = SET_SRC (p_sets[0]);
6485 int ninputs = ASM_OPERANDS_INPUT_LENGTH (op);
6486 rtvec inputs = ASM_OPERANDS_INPUT_VEC (op);
6487 bool *output_matched = XALLOCAVEC (bool, noutputs);
6488
6489 memset (output_matched, 0, noutputs * sizeof (bool));
6490 for (i = 0; i < ninputs; i++)
6491 {
6492 rtx input, output;
6493 rtx_insn *insns;
6494 const char *constraint = ASM_OPERANDS_INPUT_CONSTRAINT (op, i);
6495 int match, j;
6496
6497 match = matching_constraint_num (constraint);
6498 if (match < 0)
6499 continue;
6500
6501 gcc_assert (match < noutputs);
6502 output = SET_DEST (p_sets[match]);
6503 input = RTVEC_ELT (inputs, i);
6504 /* Only do the transformation for pseudos. */
6505 if (! REG_P (output)
6506 || rtx_equal_p (output, input)
6507 || !(REG_P (input) || SUBREG_P (input)
6508 || MEM_P (input) || CONSTANT_P (input))
6509 || !general_operand (input, GET_MODE (output)))
6510 continue;
6511
6512 /* We can't do anything if the output is also used as input,
6513 as we're going to overwrite it. */
6514 for (j = 0; j < ninputs; j++)
6515 if (reg_overlap_mentioned_p (output, RTVEC_ELT (inputs, j)))
6516 break;
6517 if (j != ninputs)
6518 continue;
6519
6520 /* Avoid changing the same input several times. For
6521 asm ("" : "=mr" (out1), "=mr" (out2) : "0" (in), "1" (in));
6522 only change it once (to out1), rather than changing it
6523 first to out1 and afterwards to out2. */
6524 if (i > 0)
6525 {
6526 for (j = 0; j < noutputs; j++)
6527 if (output_matched[j] && input == SET_DEST (p_sets[j]))
6528 break;
6529 if (j != noutputs)
6530 continue;
6531 }
6532 output_matched[match] = true;
6533
6534 start_sequence ();
6535 emit_move_insn (output, copy_rtx (input));
6536 insns = get_insns ();
6537 end_sequence ();
6538 emit_insn_before (insns, insn);
6539
6540 constraint = ASM_OPERANDS_OUTPUT_CONSTRAINT(SET_SRC(p_sets[match]));
6541 bool early_clobber_p = strchr (constraint, '&') != NULL;
6542
6543 /* Now replace all mentions of the input with output. We can't
6544 just replace the occurrence in inputs[i], as the register might
6545 also be used in some other input (or even in an address of an
6546 output), which would mean possibly increasing the number of
6547 inputs by one (namely 'output' in addition), which might pose
6548 a too complicated problem for reload to solve. E.g. this situation:
6549
6550 asm ("" : "=r" (output), "=m" (input) : "0" (input))
6551
6552 Here 'input' is used in two occurrences as input (once for the
6553 input operand, once for the address in the second output operand).
6554 If we would replace only the occurrence of the input operand (to
6555 make the matching) we would be left with this:
6556
6557 output = input
6558 asm ("" : "=r" (output), "=m" (input) : "0" (output))
6559
6560 Now we suddenly have two different input values (containing the same
6561 value, but different pseudos) where we formerly had only one.
6562 With more complicated asms this might lead to reload failures
6563 which wouldn't have happen without this pass. So, iterate over
6564 all operands and replace all occurrences of the register used.
6565
6566 However, if one or more of the 'input' uses have a non-matching
6567 constraint and the matched output operand is an early clobber
6568 operand, then do not replace the input operand, since by definition
6569 it conflicts with the output operand and cannot share the same
6570 register. See PR89313 for details. */
6571
6572 for (j = 0; j < noutputs; j++)
6573 if (!rtx_equal_p (SET_DEST (p_sets[j]), input)
6574 && reg_overlap_mentioned_p (input, SET_DEST (p_sets[j])))
6575 SET_DEST (p_sets[j]) = replace_rtx (SET_DEST (p_sets[j]),
6576 input, output);
6577 for (j = 0; j < ninputs; j++)
6578 if (reg_overlap_mentioned_p (input, RTVEC_ELT (inputs, j)))
6579 {
6580 if (!early_clobber_p
6581 || match == matching_constraint_num
6582 (ASM_OPERANDS_INPUT_CONSTRAINT (op, j)))
6583 RTVEC_ELT (inputs, j) = replace_rtx (RTVEC_ELT (inputs, j),
6584 input, output);
6585 }
6586
6587 changed = true;
6588 }
6589
6590 if (changed)
6591 df_insn_rescan (insn);
6592 }
6593
6594 /* Add the decl D to the local_decls list of FUN. */
6595
6596 void
6597 add_local_decl (struct function *fun, tree d)
6598 {
6599 gcc_assert (VAR_P (d));
6600 vec_safe_push (fun->local_decls, d);
6601 }
6602
6603 namespace {
6604
6605 const pass_data pass_data_match_asm_constraints =
6606 {
6607 RTL_PASS, /* type */
6608 "asmcons", /* name */
6609 OPTGROUP_NONE, /* optinfo_flags */
6610 TV_NONE, /* tv_id */
6611 0, /* properties_required */
6612 0, /* properties_provided */
6613 0, /* properties_destroyed */
6614 0, /* todo_flags_start */
6615 0, /* todo_flags_finish */
6616 };
6617
6618 class pass_match_asm_constraints : public rtl_opt_pass
6619 {
6620 public:
6621 pass_match_asm_constraints (gcc::context *ctxt)
6622 : rtl_opt_pass (pass_data_match_asm_constraints, ctxt)
6623 {}
6624
6625 /* opt_pass methods: */
6626 virtual unsigned int execute (function *);
6627
6628 }; // class pass_match_asm_constraints
6629
6630 unsigned
6631 pass_match_asm_constraints::execute (function *fun)
6632 {
6633 basic_block bb;
6634 rtx_insn *insn;
6635 rtx pat, *p_sets;
6636 int noutputs;
6637
6638 if (!crtl->has_asm_statement)
6639 return 0;
6640
6641 df_set_flags (DF_DEFER_INSN_RESCAN);
6642 FOR_EACH_BB_FN (bb, fun)
6643 {
6644 FOR_BB_INSNS (bb, insn)
6645 {
6646 if (!INSN_P (insn))
6647 continue;
6648
6649 pat = PATTERN (insn);
6650 if (GET_CODE (pat) == PARALLEL)
6651 p_sets = &XVECEXP (pat, 0, 0), noutputs = XVECLEN (pat, 0);
6652 else if (GET_CODE (pat) == SET)
6653 p_sets = &PATTERN (insn), noutputs = 1;
6654 else
6655 continue;
6656
6657 if (GET_CODE (*p_sets) == SET
6658 && GET_CODE (SET_SRC (*p_sets)) == ASM_OPERANDS)
6659 match_asm_constraints_1 (insn, p_sets, noutputs);
6660 }
6661 }
6662
6663 return TODO_df_finish;
6664 }
6665
6666 } // anon namespace
6667
6668 rtl_opt_pass *
6669 make_pass_match_asm_constraints (gcc::context *ctxt)
6670 {
6671 return new pass_match_asm_constraints (ctxt);
6672 }
6673
6674
6675 #include "gt-function.h"