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