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Add inline functions for various bitwise operations.
[thirdparty/gcc.git] / gcc / function.c
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 ((TREE_CODE (t) == VAR_DECL
1830 || TREE_CODE (t) == RESULT_DECL)
1831 && DECL_HAS_VALUE_EXPR_P (t))
1832 {
1833 tree v = DECL_VALUE_EXPR (t);
1834 walk_tree (&v, instantiate_expr, NULL, NULL);
1835 }
1836 }
1837 }
1838 return NULL;
1839 }
1840
1841 /* Subroutine of instantiate_decls: Process all decls in the given
1842 BLOCK node and all its subblocks. */
1843
1844 static void
1845 instantiate_decls_1 (tree let)
1846 {
1847 tree t;
1848
1849 for (t = BLOCK_VARS (let); t; t = DECL_CHAIN (t))
1850 {
1851 if (DECL_RTL_SET_P (t))
1852 instantiate_decl_rtl (DECL_RTL (t));
1853 if (TREE_CODE (t) == VAR_DECL && DECL_HAS_VALUE_EXPR_P (t))
1854 {
1855 tree v = DECL_VALUE_EXPR (t);
1856 walk_tree (&v, instantiate_expr, NULL, NULL);
1857 }
1858 }
1859
1860 /* Process all subblocks. */
1861 for (t = BLOCK_SUBBLOCKS (let); t; t = BLOCK_CHAIN (t))
1862 instantiate_decls_1 (t);
1863 }
1864
1865 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1866 all virtual registers in their DECL_RTL's. */
1867
1868 static void
1869 instantiate_decls (tree fndecl)
1870 {
1871 tree decl;
1872 unsigned ix;
1873
1874 /* Process all parameters of the function. */
1875 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = DECL_CHAIN (decl))
1876 {
1877 instantiate_decl_rtl (DECL_RTL (decl));
1878 instantiate_decl_rtl (DECL_INCOMING_RTL (decl));
1879 if (DECL_HAS_VALUE_EXPR_P (decl))
1880 {
1881 tree v = DECL_VALUE_EXPR (decl);
1882 walk_tree (&v, instantiate_expr, NULL, NULL);
1883 }
1884 }
1885
1886 if ((decl = DECL_RESULT (fndecl))
1887 && TREE_CODE (decl) == RESULT_DECL)
1888 {
1889 if (DECL_RTL_SET_P (decl))
1890 instantiate_decl_rtl (DECL_RTL (decl));
1891 if (DECL_HAS_VALUE_EXPR_P (decl))
1892 {
1893 tree v = DECL_VALUE_EXPR (decl);
1894 walk_tree (&v, instantiate_expr, NULL, NULL);
1895 }
1896 }
1897
1898 /* Process the saved static chain if it exists. */
1899 decl = DECL_STRUCT_FUNCTION (fndecl)->static_chain_decl;
1900 if (decl && DECL_HAS_VALUE_EXPR_P (decl))
1901 instantiate_decl_rtl (DECL_RTL (DECL_VALUE_EXPR (decl)));
1902
1903 /* Now process all variables defined in the function or its subblocks. */
1904 instantiate_decls_1 (DECL_INITIAL (fndecl));
1905
1906 FOR_EACH_LOCAL_DECL (cfun, ix, decl)
1907 if (DECL_RTL_SET_P (decl))
1908 instantiate_decl_rtl (DECL_RTL (decl));
1909 vec_free (cfun->local_decls);
1910 }
1911
1912 /* Pass through the INSNS of function FNDECL and convert virtual register
1913 references to hard register references. */
1914
1915 static unsigned int
1916 instantiate_virtual_regs (void)
1917 {
1918 rtx_insn *insn;
1919
1920 /* Compute the offsets to use for this function. */
1921 in_arg_offset = FIRST_PARM_OFFSET (current_function_decl);
1922 var_offset = STARTING_FRAME_OFFSET;
1923 dynamic_offset = STACK_DYNAMIC_OFFSET (current_function_decl);
1924 out_arg_offset = STACK_POINTER_OFFSET;
1925 #ifdef FRAME_POINTER_CFA_OFFSET
1926 cfa_offset = FRAME_POINTER_CFA_OFFSET (current_function_decl);
1927 #else
1928 cfa_offset = ARG_POINTER_CFA_OFFSET (current_function_decl);
1929 #endif
1930
1931 /* Initialize recognition, indicating that volatile is OK. */
1932 init_recog ();
1933
1934 /* Scan through all the insns, instantiating every virtual register still
1935 present. */
1936 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
1937 if (INSN_P (insn))
1938 {
1939 /* These patterns in the instruction stream can never be recognized.
1940 Fortunately, they shouldn't contain virtual registers either. */
1941 if (GET_CODE (PATTERN (insn)) == USE
1942 || GET_CODE (PATTERN (insn)) == CLOBBER
1943 || GET_CODE (PATTERN (insn)) == ASM_INPUT)
1944 continue;
1945 else if (DEBUG_INSN_P (insn))
1946 instantiate_virtual_regs_in_rtx (&INSN_VAR_LOCATION (insn));
1947 else
1948 instantiate_virtual_regs_in_insn (insn);
1949
1950 if (insn->deleted ())
1951 continue;
1952
1953 instantiate_virtual_regs_in_rtx (&REG_NOTES (insn));
1954
1955 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
1956 if (CALL_P (insn))
1957 instantiate_virtual_regs_in_rtx (&CALL_INSN_FUNCTION_USAGE (insn));
1958 }
1959
1960 /* Instantiate the virtual registers in the DECLs for debugging purposes. */
1961 instantiate_decls (current_function_decl);
1962
1963 targetm.instantiate_decls ();
1964
1965 /* Indicate that, from now on, assign_stack_local should use
1966 frame_pointer_rtx. */
1967 virtuals_instantiated = 1;
1968
1969 return 0;
1970 }
1971
1972 namespace {
1973
1974 const pass_data pass_data_instantiate_virtual_regs =
1975 {
1976 RTL_PASS, /* type */
1977 "vregs", /* name */
1978 OPTGROUP_NONE, /* optinfo_flags */
1979 TV_NONE, /* tv_id */
1980 0, /* properties_required */
1981 0, /* properties_provided */
1982 0, /* properties_destroyed */
1983 0, /* todo_flags_start */
1984 0, /* todo_flags_finish */
1985 };
1986
1987 class pass_instantiate_virtual_regs : public rtl_opt_pass
1988 {
1989 public:
1990 pass_instantiate_virtual_regs (gcc::context *ctxt)
1991 : rtl_opt_pass (pass_data_instantiate_virtual_regs, ctxt)
1992 {}
1993
1994 /* opt_pass methods: */
1995 virtual unsigned int execute (function *)
1996 {
1997 return instantiate_virtual_regs ();
1998 }
1999
2000 }; // class pass_instantiate_virtual_regs
2001
2002 } // anon namespace
2003
2004 rtl_opt_pass *
2005 make_pass_instantiate_virtual_regs (gcc::context *ctxt)
2006 {
2007 return new pass_instantiate_virtual_regs (ctxt);
2008 }
2009
2010 \f
2011 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
2012 This means a type for which function calls must pass an address to the
2013 function or get an address back from the function.
2014 EXP may be a type node or an expression (whose type is tested). */
2015
2016 int
2017 aggregate_value_p (const_tree exp, const_tree fntype)
2018 {
2019 const_tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
2020 int i, regno, nregs;
2021 rtx reg;
2022
2023 if (fntype)
2024 switch (TREE_CODE (fntype))
2025 {
2026 case CALL_EXPR:
2027 {
2028 tree fndecl = get_callee_fndecl (fntype);
2029 if (fndecl)
2030 fntype = TREE_TYPE (fndecl);
2031 else if (CALL_EXPR_FN (fntype))
2032 fntype = TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (fntype)));
2033 else
2034 /* For internal functions, assume nothing needs to be
2035 returned in memory. */
2036 return 0;
2037 }
2038 break;
2039 case FUNCTION_DECL:
2040 fntype = TREE_TYPE (fntype);
2041 break;
2042 case FUNCTION_TYPE:
2043 case METHOD_TYPE:
2044 break;
2045 case IDENTIFIER_NODE:
2046 fntype = NULL_TREE;
2047 break;
2048 default:
2049 /* We don't expect other tree types here. */
2050 gcc_unreachable ();
2051 }
2052
2053 if (VOID_TYPE_P (type))
2054 return 0;
2055
2056 /* If a record should be passed the same as its first (and only) member
2057 don't pass it as an aggregate. */
2058 if (TREE_CODE (type) == RECORD_TYPE && TYPE_TRANSPARENT_AGGR (type))
2059 return aggregate_value_p (first_field (type), fntype);
2060
2061 /* If the front end has decided that this needs to be passed by
2062 reference, do so. */
2063 if ((TREE_CODE (exp) == PARM_DECL || TREE_CODE (exp) == RESULT_DECL)
2064 && DECL_BY_REFERENCE (exp))
2065 return 1;
2066
2067 /* Function types that are TREE_ADDRESSABLE force return in memory. */
2068 if (fntype && TREE_ADDRESSABLE (fntype))
2069 return 1;
2070
2071 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
2072 and thus can't be returned in registers. */
2073 if (TREE_ADDRESSABLE (type))
2074 return 1;
2075
2076 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
2077 return 1;
2078
2079 if (targetm.calls.return_in_memory (type, fntype))
2080 return 1;
2081
2082 /* Make sure we have suitable call-clobbered regs to return
2083 the value in; if not, we must return it in memory. */
2084 reg = hard_function_value (type, 0, fntype, 0);
2085
2086 /* If we have something other than a REG (e.g. a PARALLEL), then assume
2087 it is OK. */
2088 if (!REG_P (reg))
2089 return 0;
2090
2091 regno = REGNO (reg);
2092 nregs = hard_regno_nregs[regno][TYPE_MODE (type)];
2093 for (i = 0; i < nregs; i++)
2094 if (! call_used_regs[regno + i])
2095 return 1;
2096
2097 return 0;
2098 }
2099 \f
2100 /* Return true if we should assign DECL a pseudo register; false if it
2101 should live on the local stack. */
2102
2103 bool
2104 use_register_for_decl (const_tree decl)
2105 {
2106 if (TREE_CODE (decl) == SSA_NAME)
2107 {
2108 /* We often try to use the SSA_NAME, instead of its underlying
2109 decl, to get type information and guide decisions, to avoid
2110 differences of behavior between anonymous and named
2111 variables, but in this one case we have to go for the actual
2112 variable if there is one. The main reason is that, at least
2113 at -O0, we want to place user variables on the stack, but we
2114 don't mind using pseudos for anonymous or ignored temps.
2115 Should we take the SSA_NAME, we'd conclude all SSA_NAMEs
2116 should go in pseudos, whereas their corresponding variables
2117 might have to go on the stack. So, disregarding the decl
2118 here would negatively impact debug info at -O0, enable
2119 coalescing between SSA_NAMEs that ought to get different
2120 stack/pseudo assignments, and get the incoming argument
2121 processing thoroughly confused by PARM_DECLs expected to live
2122 in stack slots but assigned to pseudos. */
2123 if (!SSA_NAME_VAR (decl))
2124 return TYPE_MODE (TREE_TYPE (decl)) != BLKmode
2125 && !(flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)));
2126
2127 decl = SSA_NAME_VAR (decl);
2128 }
2129
2130 /* Honor volatile. */
2131 if (TREE_SIDE_EFFECTS (decl))
2132 return false;
2133
2134 /* Honor addressability. */
2135 if (TREE_ADDRESSABLE (decl))
2136 return false;
2137
2138 /* RESULT_DECLs are a bit special in that they're assigned without
2139 regard to use_register_for_decl, but we generally only store in
2140 them. If we coalesce their SSA NAMEs, we'd better return a
2141 result that matches the assignment in expand_function_start. */
2142 if (TREE_CODE (decl) == RESULT_DECL)
2143 {
2144 /* If it's not an aggregate, we're going to use a REG or a
2145 PARALLEL containing a REG. */
2146 if (!aggregate_value_p (decl, current_function_decl))
2147 return true;
2148
2149 /* If expand_function_start determines the return value, we'll
2150 use MEM if it's not by reference. */
2151 if (cfun->returns_pcc_struct
2152 || (targetm.calls.struct_value_rtx
2153 (TREE_TYPE (current_function_decl), 1)))
2154 return DECL_BY_REFERENCE (decl);
2155
2156 /* Otherwise, we're taking an extra all.function_result_decl
2157 argument. It's set up in assign_parms_augmented_arg_list,
2158 under the (negated) conditions above, and then it's used to
2159 set up the RESULT_DECL rtl in assign_params, after looping
2160 over all parameters. Now, if the RESULT_DECL is not by
2161 reference, we'll use a MEM either way. */
2162 if (!DECL_BY_REFERENCE (decl))
2163 return false;
2164
2165 /* Otherwise, if RESULT_DECL is DECL_BY_REFERENCE, it will take
2166 the function_result_decl's assignment. Since it's a pointer,
2167 we can short-circuit a number of the tests below, and we must
2168 duplicat e them because we don't have the
2169 function_result_decl to test. */
2170 if (!targetm.calls.allocate_stack_slots_for_args ())
2171 return true;
2172 /* We don't set DECL_IGNORED_P for the function_result_decl. */
2173 if (optimize)
2174 return true;
2175 /* We don't set DECL_REGISTER for the function_result_decl. */
2176 return false;
2177 }
2178
2179 /* Decl is implicitly addressible by bound stores and loads
2180 if it is an aggregate holding bounds. */
2181 if (chkp_function_instrumented_p (current_function_decl)
2182 && TREE_TYPE (decl)
2183 && !BOUNDED_P (decl)
2184 && chkp_type_has_pointer (TREE_TYPE (decl)))
2185 return false;
2186
2187 /* Only register-like things go in registers. */
2188 if (DECL_MODE (decl) == BLKmode)
2189 return false;
2190
2191 /* If -ffloat-store specified, don't put explicit float variables
2192 into registers. */
2193 /* ??? This should be checked after DECL_ARTIFICIAL, but tree-ssa
2194 propagates values across these stores, and it probably shouldn't. */
2195 if (flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)))
2196 return false;
2197
2198 if (!targetm.calls.allocate_stack_slots_for_args ())
2199 return true;
2200
2201 /* If we're not interested in tracking debugging information for
2202 this decl, then we can certainly put it in a register. */
2203 if (DECL_IGNORED_P (decl))
2204 return true;
2205
2206 if (optimize)
2207 return true;
2208
2209 if (!DECL_REGISTER (decl))
2210 return false;
2211
2212 switch (TREE_CODE (TREE_TYPE (decl)))
2213 {
2214 case RECORD_TYPE:
2215 case UNION_TYPE:
2216 case QUAL_UNION_TYPE:
2217 /* When not optimizing, disregard register keyword for variables with
2218 types containing methods, otherwise the methods won't be callable
2219 from the debugger. */
2220 if (TYPE_METHODS (TYPE_MAIN_VARIANT (TREE_TYPE (decl))))
2221 return false;
2222 break;
2223 default:
2224 break;
2225 }
2226
2227 return true;
2228 }
2229
2230 /* Structures to communicate between the subroutines of assign_parms.
2231 The first holds data persistent across all parameters, the second
2232 is cleared out for each parameter. */
2233
2234 struct assign_parm_data_all
2235 {
2236 /* When INIT_CUMULATIVE_ARGS gets revamped, allocating CUMULATIVE_ARGS
2237 should become a job of the target or otherwise encapsulated. */
2238 CUMULATIVE_ARGS args_so_far_v;
2239 cumulative_args_t args_so_far;
2240 struct args_size stack_args_size;
2241 tree function_result_decl;
2242 tree orig_fnargs;
2243 rtx_insn *first_conversion_insn;
2244 rtx_insn *last_conversion_insn;
2245 HOST_WIDE_INT pretend_args_size;
2246 HOST_WIDE_INT extra_pretend_bytes;
2247 int reg_parm_stack_space;
2248 };
2249
2250 struct assign_parm_data_one
2251 {
2252 tree nominal_type;
2253 tree passed_type;
2254 rtx entry_parm;
2255 rtx stack_parm;
2256 machine_mode nominal_mode;
2257 machine_mode passed_mode;
2258 machine_mode promoted_mode;
2259 struct locate_and_pad_arg_data locate;
2260 int partial;
2261 BOOL_BITFIELD named_arg : 1;
2262 BOOL_BITFIELD passed_pointer : 1;
2263 BOOL_BITFIELD on_stack : 1;
2264 BOOL_BITFIELD loaded_in_reg : 1;
2265 };
2266
2267 struct bounds_parm_data
2268 {
2269 assign_parm_data_one parm_data;
2270 tree bounds_parm;
2271 tree ptr_parm;
2272 rtx ptr_entry;
2273 int bound_no;
2274 };
2275
2276 /* A subroutine of assign_parms. Initialize ALL. */
2277
2278 static void
2279 assign_parms_initialize_all (struct assign_parm_data_all *all)
2280 {
2281 tree fntype ATTRIBUTE_UNUSED;
2282
2283 memset (all, 0, sizeof (*all));
2284
2285 fntype = TREE_TYPE (current_function_decl);
2286
2287 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
2288 INIT_CUMULATIVE_INCOMING_ARGS (all->args_so_far_v, fntype, NULL_RTX);
2289 #else
2290 INIT_CUMULATIVE_ARGS (all->args_so_far_v, fntype, NULL_RTX,
2291 current_function_decl, -1);
2292 #endif
2293 all->args_so_far = pack_cumulative_args (&all->args_so_far_v);
2294
2295 #ifdef INCOMING_REG_PARM_STACK_SPACE
2296 all->reg_parm_stack_space
2297 = INCOMING_REG_PARM_STACK_SPACE (current_function_decl);
2298 #endif
2299 }
2300
2301 /* If ARGS contains entries with complex types, split the entry into two
2302 entries of the component type. Return a new list of substitutions are
2303 needed, else the old list. */
2304
2305 static void
2306 split_complex_args (vec<tree> *args)
2307 {
2308 unsigned i;
2309 tree p;
2310
2311 FOR_EACH_VEC_ELT (*args, i, p)
2312 {
2313 tree type = TREE_TYPE (p);
2314 if (TREE_CODE (type) == COMPLEX_TYPE
2315 && targetm.calls.split_complex_arg (type))
2316 {
2317 tree decl;
2318 tree subtype = TREE_TYPE (type);
2319 bool addressable = TREE_ADDRESSABLE (p);
2320
2321 /* Rewrite the PARM_DECL's type with its component. */
2322 p = copy_node (p);
2323 TREE_TYPE (p) = subtype;
2324 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
2325 DECL_MODE (p) = VOIDmode;
2326 DECL_SIZE (p) = NULL;
2327 DECL_SIZE_UNIT (p) = NULL;
2328 /* If this arg must go in memory, put it in a pseudo here.
2329 We can't allow it to go in memory as per normal parms,
2330 because the usual place might not have the imag part
2331 adjacent to the real part. */
2332 DECL_ARTIFICIAL (p) = addressable;
2333 DECL_IGNORED_P (p) = addressable;
2334 TREE_ADDRESSABLE (p) = 0;
2335 layout_decl (p, 0);
2336 (*args)[i] = p;
2337
2338 /* Build a second synthetic decl. */
2339 decl = build_decl (EXPR_LOCATION (p),
2340 PARM_DECL, NULL_TREE, subtype);
2341 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
2342 DECL_ARTIFICIAL (decl) = addressable;
2343 DECL_IGNORED_P (decl) = addressable;
2344 layout_decl (decl, 0);
2345 args->safe_insert (++i, decl);
2346 }
2347 }
2348 }
2349
2350 /* A subroutine of assign_parms. Adjust the parameter list to incorporate
2351 the hidden struct return argument, and (abi willing) complex args.
2352 Return the new parameter list. */
2353
2354 static vec<tree>
2355 assign_parms_augmented_arg_list (struct assign_parm_data_all *all)
2356 {
2357 tree fndecl = current_function_decl;
2358 tree fntype = TREE_TYPE (fndecl);
2359 vec<tree> fnargs = vNULL;
2360 tree arg;
2361
2362 for (arg = DECL_ARGUMENTS (fndecl); arg; arg = DECL_CHAIN (arg))
2363 fnargs.safe_push (arg);
2364
2365 all->orig_fnargs = DECL_ARGUMENTS (fndecl);
2366
2367 /* If struct value address is treated as the first argument, make it so. */
2368 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
2369 && ! cfun->returns_pcc_struct
2370 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
2371 {
2372 tree type = build_pointer_type (TREE_TYPE (fntype));
2373 tree decl;
2374
2375 decl = build_decl (DECL_SOURCE_LOCATION (fndecl),
2376 PARM_DECL, get_identifier (".result_ptr"), type);
2377 DECL_ARG_TYPE (decl) = type;
2378 DECL_ARTIFICIAL (decl) = 1;
2379 DECL_NAMELESS (decl) = 1;
2380 TREE_CONSTANT (decl) = 1;
2381 /* We don't set DECL_IGNORED_P or DECL_REGISTER here. If this
2382 changes, the end of the RESULT_DECL handling block in
2383 use_register_for_decl must be adjusted to match. */
2384
2385 DECL_CHAIN (decl) = all->orig_fnargs;
2386 all->orig_fnargs = decl;
2387 fnargs.safe_insert (0, decl);
2388
2389 all->function_result_decl = decl;
2390
2391 /* If function is instrumented then bounds of the
2392 passed structure address is the second argument. */
2393 if (chkp_function_instrumented_p (fndecl))
2394 {
2395 decl = build_decl (DECL_SOURCE_LOCATION (fndecl),
2396 PARM_DECL, get_identifier (".result_bnd"),
2397 pointer_bounds_type_node);
2398 DECL_ARG_TYPE (decl) = pointer_bounds_type_node;
2399 DECL_ARTIFICIAL (decl) = 1;
2400 DECL_NAMELESS (decl) = 1;
2401 TREE_CONSTANT (decl) = 1;
2402
2403 DECL_CHAIN (decl) = DECL_CHAIN (all->orig_fnargs);
2404 DECL_CHAIN (all->orig_fnargs) = decl;
2405 fnargs.safe_insert (1, decl);
2406 }
2407 }
2408
2409 /* If the target wants to split complex arguments into scalars, do so. */
2410 if (targetm.calls.split_complex_arg)
2411 split_complex_args (&fnargs);
2412
2413 return fnargs;
2414 }
2415
2416 /* A subroutine of assign_parms. Examine PARM and pull out type and mode
2417 data for the parameter. Incorporate ABI specifics such as pass-by-
2418 reference and type promotion. */
2419
2420 static void
2421 assign_parm_find_data_types (struct assign_parm_data_all *all, tree parm,
2422 struct assign_parm_data_one *data)
2423 {
2424 tree nominal_type, passed_type;
2425 machine_mode nominal_mode, passed_mode, promoted_mode;
2426 int unsignedp;
2427
2428 memset (data, 0, sizeof (*data));
2429
2430 /* NAMED_ARG is a misnomer. We really mean 'non-variadic'. */
2431 if (!cfun->stdarg)
2432 data->named_arg = 1; /* No variadic parms. */
2433 else if (DECL_CHAIN (parm))
2434 data->named_arg = 1; /* Not the last non-variadic parm. */
2435 else if (targetm.calls.strict_argument_naming (all->args_so_far))
2436 data->named_arg = 1; /* Only variadic ones are unnamed. */
2437 else
2438 data->named_arg = 0; /* Treat as variadic. */
2439
2440 nominal_type = TREE_TYPE (parm);
2441 passed_type = DECL_ARG_TYPE (parm);
2442
2443 /* Look out for errors propagating this far. Also, if the parameter's
2444 type is void then its value doesn't matter. */
2445 if (TREE_TYPE (parm) == error_mark_node
2446 /* This can happen after weird syntax errors
2447 or if an enum type is defined among the parms. */
2448 || TREE_CODE (parm) != PARM_DECL
2449 || passed_type == NULL
2450 || VOID_TYPE_P (nominal_type))
2451 {
2452 nominal_type = passed_type = void_type_node;
2453 nominal_mode = passed_mode = promoted_mode = VOIDmode;
2454 goto egress;
2455 }
2456
2457 /* Find mode of arg as it is passed, and mode of arg as it should be
2458 during execution of this function. */
2459 passed_mode = TYPE_MODE (passed_type);
2460 nominal_mode = TYPE_MODE (nominal_type);
2461
2462 /* If the parm is to be passed as a transparent union or record, use the
2463 type of the first field for the tests below. We have already verified
2464 that the modes are the same. */
2465 if ((TREE_CODE (passed_type) == UNION_TYPE
2466 || TREE_CODE (passed_type) == RECORD_TYPE)
2467 && TYPE_TRANSPARENT_AGGR (passed_type))
2468 passed_type = TREE_TYPE (first_field (passed_type));
2469
2470 /* See if this arg was passed by invisible reference. */
2471 if (pass_by_reference (&all->args_so_far_v, passed_mode,
2472 passed_type, data->named_arg))
2473 {
2474 passed_type = nominal_type = build_pointer_type (passed_type);
2475 data->passed_pointer = true;
2476 passed_mode = nominal_mode = TYPE_MODE (nominal_type);
2477 }
2478
2479 /* Find mode as it is passed by the ABI. */
2480 unsignedp = TYPE_UNSIGNED (passed_type);
2481 promoted_mode = promote_function_mode (passed_type, passed_mode, &unsignedp,
2482 TREE_TYPE (current_function_decl), 0);
2483
2484 egress:
2485 data->nominal_type = nominal_type;
2486 data->passed_type = passed_type;
2487 data->nominal_mode = nominal_mode;
2488 data->passed_mode = passed_mode;
2489 data->promoted_mode = promoted_mode;
2490 }
2491
2492 /* A subroutine of assign_parms. Invoke setup_incoming_varargs. */
2493
2494 static void
2495 assign_parms_setup_varargs (struct assign_parm_data_all *all,
2496 struct assign_parm_data_one *data, bool no_rtl)
2497 {
2498 int varargs_pretend_bytes = 0;
2499
2500 targetm.calls.setup_incoming_varargs (all->args_so_far,
2501 data->promoted_mode,
2502 data->passed_type,
2503 &varargs_pretend_bytes, no_rtl);
2504
2505 /* If the back-end has requested extra stack space, record how much is
2506 needed. Do not change pretend_args_size otherwise since it may be
2507 nonzero from an earlier partial argument. */
2508 if (varargs_pretend_bytes > 0)
2509 all->pretend_args_size = varargs_pretend_bytes;
2510 }
2511
2512 /* A subroutine of assign_parms. Set DATA->ENTRY_PARM corresponding to
2513 the incoming location of the current parameter. */
2514
2515 static void
2516 assign_parm_find_entry_rtl (struct assign_parm_data_all *all,
2517 struct assign_parm_data_one *data)
2518 {
2519 HOST_WIDE_INT pretend_bytes = 0;
2520 rtx entry_parm;
2521 bool in_regs;
2522
2523 if (data->promoted_mode == VOIDmode)
2524 {
2525 data->entry_parm = data->stack_parm = const0_rtx;
2526 return;
2527 }
2528
2529 entry_parm = targetm.calls.function_incoming_arg (all->args_so_far,
2530 data->promoted_mode,
2531 data->passed_type,
2532 data->named_arg);
2533
2534 if (entry_parm == 0)
2535 data->promoted_mode = data->passed_mode;
2536
2537 /* Determine parm's home in the stack, in case it arrives in the stack
2538 or we should pretend it did. Compute the stack position and rtx where
2539 the argument arrives and its size.
2540
2541 There is one complexity here: If this was a parameter that would
2542 have been passed in registers, but wasn't only because it is
2543 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2544 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2545 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of 0
2546 as it was the previous time. */
2547 in_regs = (entry_parm != 0) || POINTER_BOUNDS_TYPE_P (data->passed_type);
2548 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2549 in_regs = true;
2550 #endif
2551 if (!in_regs && !data->named_arg)
2552 {
2553 if (targetm.calls.pretend_outgoing_varargs_named (all->args_so_far))
2554 {
2555 rtx tem;
2556 tem = targetm.calls.function_incoming_arg (all->args_so_far,
2557 data->promoted_mode,
2558 data->passed_type, true);
2559 in_regs = tem != NULL;
2560 }
2561 }
2562
2563 /* If this parameter was passed both in registers and in the stack, use
2564 the copy on the stack. */
2565 if (targetm.calls.must_pass_in_stack (data->promoted_mode,
2566 data->passed_type))
2567 entry_parm = 0;
2568
2569 if (entry_parm)
2570 {
2571 int partial;
2572
2573 partial = targetm.calls.arg_partial_bytes (all->args_so_far,
2574 data->promoted_mode,
2575 data->passed_type,
2576 data->named_arg);
2577 data->partial = partial;
2578
2579 /* The caller might already have allocated stack space for the
2580 register parameters. */
2581 if (partial != 0 && all->reg_parm_stack_space == 0)
2582 {
2583 /* Part of this argument is passed in registers and part
2584 is passed on the stack. Ask the prologue code to extend
2585 the stack part so that we can recreate the full value.
2586
2587 PRETEND_BYTES is the size of the registers we need to store.
2588 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
2589 stack space that the prologue should allocate.
2590
2591 Internally, gcc assumes that the argument pointer is aligned
2592 to STACK_BOUNDARY bits. This is used both for alignment
2593 optimizations (see init_emit) and to locate arguments that are
2594 aligned to more than PARM_BOUNDARY bits. We must preserve this
2595 invariant by rounding CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to
2596 a stack boundary. */
2597
2598 /* We assume at most one partial arg, and it must be the first
2599 argument on the stack. */
2600 gcc_assert (!all->extra_pretend_bytes && !all->pretend_args_size);
2601
2602 pretend_bytes = partial;
2603 all->pretend_args_size = CEIL_ROUND (pretend_bytes, STACK_BYTES);
2604
2605 /* We want to align relative to the actual stack pointer, so
2606 don't include this in the stack size until later. */
2607 all->extra_pretend_bytes = all->pretend_args_size;
2608 }
2609 }
2610
2611 locate_and_pad_parm (data->promoted_mode, data->passed_type, in_regs,
2612 all->reg_parm_stack_space,
2613 entry_parm ? data->partial : 0, current_function_decl,
2614 &all->stack_args_size, &data->locate);
2615
2616 /* Update parm_stack_boundary if this parameter is passed in the
2617 stack. */
2618 if (!in_regs && crtl->parm_stack_boundary < data->locate.boundary)
2619 crtl->parm_stack_boundary = data->locate.boundary;
2620
2621 /* Adjust offsets to include the pretend args. */
2622 pretend_bytes = all->extra_pretend_bytes - pretend_bytes;
2623 data->locate.slot_offset.constant += pretend_bytes;
2624 data->locate.offset.constant += pretend_bytes;
2625
2626 data->entry_parm = entry_parm;
2627 }
2628
2629 /* A subroutine of assign_parms. If there is actually space on the stack
2630 for this parm, count it in stack_args_size and return true. */
2631
2632 static bool
2633 assign_parm_is_stack_parm (struct assign_parm_data_all *all,
2634 struct assign_parm_data_one *data)
2635 {
2636 /* Bounds are never passed on the stack to keep compatibility
2637 with not instrumented code. */
2638 if (POINTER_BOUNDS_TYPE_P (data->passed_type))
2639 return false;
2640 /* Trivially true if we've no incoming register. */
2641 else if (data->entry_parm == NULL)
2642 ;
2643 /* Also true if we're partially in registers and partially not,
2644 since we've arranged to drop the entire argument on the stack. */
2645 else if (data->partial != 0)
2646 ;
2647 /* Also true if the target says that it's passed in both registers
2648 and on the stack. */
2649 else if (GET_CODE (data->entry_parm) == PARALLEL
2650 && XEXP (XVECEXP (data->entry_parm, 0, 0), 0) == NULL_RTX)
2651 ;
2652 /* Also true if the target says that there's stack allocated for
2653 all register parameters. */
2654 else if (all->reg_parm_stack_space > 0)
2655 ;
2656 /* Otherwise, no, this parameter has no ABI defined stack slot. */
2657 else
2658 return false;
2659
2660 all->stack_args_size.constant += data->locate.size.constant;
2661 if (data->locate.size.var)
2662 ADD_PARM_SIZE (all->stack_args_size, data->locate.size.var);
2663
2664 return true;
2665 }
2666
2667 /* A subroutine of assign_parms. Given that this parameter is allocated
2668 stack space by the ABI, find it. */
2669
2670 static void
2671 assign_parm_find_stack_rtl (tree parm, struct assign_parm_data_one *data)
2672 {
2673 rtx offset_rtx, stack_parm;
2674 unsigned int align, boundary;
2675
2676 /* If we're passing this arg using a reg, make its stack home the
2677 aligned stack slot. */
2678 if (data->entry_parm)
2679 offset_rtx = ARGS_SIZE_RTX (data->locate.slot_offset);
2680 else
2681 offset_rtx = ARGS_SIZE_RTX (data->locate.offset);
2682
2683 stack_parm = crtl->args.internal_arg_pointer;
2684 if (offset_rtx != const0_rtx)
2685 stack_parm = gen_rtx_PLUS (Pmode, stack_parm, offset_rtx);
2686 stack_parm = gen_rtx_MEM (data->promoted_mode, stack_parm);
2687
2688 if (!data->passed_pointer)
2689 {
2690 set_mem_attributes (stack_parm, parm, 1);
2691 /* set_mem_attributes could set MEM_SIZE to the passed mode's size,
2692 while promoted mode's size is needed. */
2693 if (data->promoted_mode != BLKmode
2694 && data->promoted_mode != DECL_MODE (parm))
2695 {
2696 set_mem_size (stack_parm, GET_MODE_SIZE (data->promoted_mode));
2697 if (MEM_EXPR (stack_parm) && MEM_OFFSET_KNOWN_P (stack_parm))
2698 {
2699 int offset = subreg_lowpart_offset (DECL_MODE (parm),
2700 data->promoted_mode);
2701 if (offset)
2702 set_mem_offset (stack_parm, MEM_OFFSET (stack_parm) - offset);
2703 }
2704 }
2705 }
2706
2707 boundary = data->locate.boundary;
2708 align = BITS_PER_UNIT;
2709
2710 /* If we're padding upward, we know that the alignment of the slot
2711 is TARGET_FUNCTION_ARG_BOUNDARY. If we're using slot_offset, we're
2712 intentionally forcing upward padding. Otherwise we have to come
2713 up with a guess at the alignment based on OFFSET_RTX. */
2714 if (data->locate.where_pad != downward || data->entry_parm)
2715 align = boundary;
2716 else if (CONST_INT_P (offset_rtx))
2717 {
2718 align = INTVAL (offset_rtx) * BITS_PER_UNIT | boundary;
2719 align = least_bit_hwi (align);
2720 }
2721 set_mem_align (stack_parm, align);
2722
2723 if (data->entry_parm)
2724 set_reg_attrs_for_parm (data->entry_parm, stack_parm);
2725
2726 data->stack_parm = stack_parm;
2727 }
2728
2729 /* A subroutine of assign_parms. Adjust DATA->ENTRY_RTL such that it's
2730 always valid and contiguous. */
2731
2732 static void
2733 assign_parm_adjust_entry_rtl (struct assign_parm_data_one *data)
2734 {
2735 rtx entry_parm = data->entry_parm;
2736 rtx stack_parm = data->stack_parm;
2737
2738 /* If this parm was passed part in regs and part in memory, pretend it
2739 arrived entirely in memory by pushing the register-part onto the stack.
2740 In the special case of a DImode or DFmode that is split, we could put
2741 it together in a pseudoreg directly, but for now that's not worth
2742 bothering with. */
2743 if (data->partial != 0)
2744 {
2745 /* Handle calls that pass values in multiple non-contiguous
2746 locations. The Irix 6 ABI has examples of this. */
2747 if (GET_CODE (entry_parm) == PARALLEL)
2748 emit_group_store (validize_mem (copy_rtx (stack_parm)), entry_parm,
2749 data->passed_type,
2750 int_size_in_bytes (data->passed_type));
2751 else
2752 {
2753 gcc_assert (data->partial % UNITS_PER_WORD == 0);
2754 move_block_from_reg (REGNO (entry_parm),
2755 validize_mem (copy_rtx (stack_parm)),
2756 data->partial / UNITS_PER_WORD);
2757 }
2758
2759 entry_parm = stack_parm;
2760 }
2761
2762 /* If we didn't decide this parm came in a register, by default it came
2763 on the stack. */
2764 else if (entry_parm == NULL)
2765 entry_parm = stack_parm;
2766
2767 /* When an argument is passed in multiple locations, we can't make use
2768 of this information, but we can save some copying if the whole argument
2769 is passed in a single register. */
2770 else if (GET_CODE (entry_parm) == PARALLEL
2771 && data->nominal_mode != BLKmode
2772 && data->passed_mode != BLKmode)
2773 {
2774 size_t i, len = XVECLEN (entry_parm, 0);
2775
2776 for (i = 0; i < len; i++)
2777 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
2778 && REG_P (XEXP (XVECEXP (entry_parm, 0, i), 0))
2779 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
2780 == data->passed_mode)
2781 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
2782 {
2783 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
2784 break;
2785 }
2786 }
2787
2788 data->entry_parm = entry_parm;
2789 }
2790
2791 /* A subroutine of assign_parms. Reconstitute any values which were
2792 passed in multiple registers and would fit in a single register. */
2793
2794 static void
2795 assign_parm_remove_parallels (struct assign_parm_data_one *data)
2796 {
2797 rtx entry_parm = data->entry_parm;
2798
2799 /* Convert the PARALLEL to a REG of the same mode as the parallel.
2800 This can be done with register operations rather than on the
2801 stack, even if we will store the reconstituted parameter on the
2802 stack later. */
2803 if (GET_CODE (entry_parm) == PARALLEL && GET_MODE (entry_parm) != BLKmode)
2804 {
2805 rtx parmreg = gen_reg_rtx (GET_MODE (entry_parm));
2806 emit_group_store (parmreg, entry_parm, data->passed_type,
2807 GET_MODE_SIZE (GET_MODE (entry_parm)));
2808 entry_parm = parmreg;
2809 }
2810
2811 data->entry_parm = entry_parm;
2812 }
2813
2814 /* A subroutine of assign_parms. Adjust DATA->STACK_RTL such that it's
2815 always valid and properly aligned. */
2816
2817 static void
2818 assign_parm_adjust_stack_rtl (struct assign_parm_data_one *data)
2819 {
2820 rtx stack_parm = data->stack_parm;
2821
2822 /* If we can't trust the parm stack slot to be aligned enough for its
2823 ultimate type, don't use that slot after entry. We'll make another
2824 stack slot, if we need one. */
2825 if (stack_parm
2826 && ((STRICT_ALIGNMENT
2827 && GET_MODE_ALIGNMENT (data->nominal_mode) > MEM_ALIGN (stack_parm))
2828 || (data->nominal_type
2829 && TYPE_ALIGN (data->nominal_type) > MEM_ALIGN (stack_parm)
2830 && MEM_ALIGN (stack_parm) < PREFERRED_STACK_BOUNDARY)))
2831 stack_parm = NULL;
2832
2833 /* If parm was passed in memory, and we need to convert it on entry,
2834 don't store it back in that same slot. */
2835 else if (data->entry_parm == stack_parm
2836 && data->nominal_mode != BLKmode
2837 && data->nominal_mode != data->passed_mode)
2838 stack_parm = NULL;
2839
2840 /* If stack protection is in effect for this function, don't leave any
2841 pointers in their passed stack slots. */
2842 else if (crtl->stack_protect_guard
2843 && (flag_stack_protect == 2
2844 || data->passed_pointer
2845 || POINTER_TYPE_P (data->nominal_type)))
2846 stack_parm = NULL;
2847
2848 data->stack_parm = stack_parm;
2849 }
2850
2851 /* A subroutine of assign_parms. Return true if the current parameter
2852 should be stored as a BLKmode in the current frame. */
2853
2854 static bool
2855 assign_parm_setup_block_p (struct assign_parm_data_one *data)
2856 {
2857 if (data->nominal_mode == BLKmode)
2858 return true;
2859 if (GET_MODE (data->entry_parm) == BLKmode)
2860 return true;
2861
2862 #ifdef BLOCK_REG_PADDING
2863 /* Only assign_parm_setup_block knows how to deal with register arguments
2864 that are padded at the least significant end. */
2865 if (REG_P (data->entry_parm)
2866 && GET_MODE_SIZE (data->promoted_mode) < UNITS_PER_WORD
2867 && (BLOCK_REG_PADDING (data->passed_mode, data->passed_type, 1)
2868 == (BYTES_BIG_ENDIAN ? upward : downward)))
2869 return true;
2870 #endif
2871
2872 return false;
2873 }
2874
2875 /* A subroutine of assign_parms. Arrange for the parameter to be
2876 present and valid in DATA->STACK_RTL. */
2877
2878 static void
2879 assign_parm_setup_block (struct assign_parm_data_all *all,
2880 tree parm, struct assign_parm_data_one *data)
2881 {
2882 rtx entry_parm = data->entry_parm;
2883 rtx stack_parm = data->stack_parm;
2884 rtx target_reg = NULL_RTX;
2885 bool in_conversion_seq = false;
2886 HOST_WIDE_INT size;
2887 HOST_WIDE_INT size_stored;
2888
2889 if (GET_CODE (entry_parm) == PARALLEL)
2890 entry_parm = emit_group_move_into_temps (entry_parm);
2891
2892 /* If we want the parameter in a pseudo, don't use a stack slot. */
2893 if (is_gimple_reg (parm) && use_register_for_decl (parm))
2894 {
2895 tree def = ssa_default_def (cfun, parm);
2896 gcc_assert (def);
2897 machine_mode mode = promote_ssa_mode (def, NULL);
2898 rtx reg = gen_reg_rtx (mode);
2899 if (GET_CODE (reg) != CONCAT)
2900 stack_parm = reg;
2901 else
2902 {
2903 target_reg = reg;
2904 /* Avoid allocating a stack slot, if there isn't one
2905 preallocated by the ABI. It might seem like we should
2906 always prefer a pseudo, but converting between
2907 floating-point and integer modes goes through the stack
2908 on various machines, so it's better to use the reserved
2909 stack slot than to risk wasting it and allocating more
2910 for the conversion. */
2911 if (stack_parm == NULL_RTX)
2912 {
2913 int save = generating_concat_p;
2914 generating_concat_p = 0;
2915 stack_parm = gen_reg_rtx (mode);
2916 generating_concat_p = save;
2917 }
2918 }
2919 data->stack_parm = NULL;
2920 }
2921
2922 size = int_size_in_bytes (data->passed_type);
2923 size_stored = CEIL_ROUND (size, UNITS_PER_WORD);
2924 if (stack_parm == 0)
2925 {
2926 SET_DECL_ALIGN (parm, MAX (DECL_ALIGN (parm), BITS_PER_WORD));
2927 stack_parm = assign_stack_local (BLKmode, size_stored,
2928 DECL_ALIGN (parm));
2929 if (GET_MODE_SIZE (GET_MODE (entry_parm)) == size)
2930 PUT_MODE (stack_parm, GET_MODE (entry_parm));
2931 set_mem_attributes (stack_parm, parm, 1);
2932 }
2933
2934 /* If a BLKmode arrives in registers, copy it to a stack slot. Handle
2935 calls that pass values in multiple non-contiguous locations. */
2936 if (REG_P (entry_parm) || GET_CODE (entry_parm) == PARALLEL)
2937 {
2938 rtx mem;
2939
2940 /* Note that we will be storing an integral number of words.
2941 So we have to be careful to ensure that we allocate an
2942 integral number of words. We do this above when we call
2943 assign_stack_local if space was not allocated in the argument
2944 list. If it was, this will not work if PARM_BOUNDARY is not
2945 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2946 if it becomes a problem. Exception is when BLKmode arrives
2947 with arguments not conforming to word_mode. */
2948
2949 if (data->stack_parm == 0)
2950 ;
2951 else if (GET_CODE (entry_parm) == PARALLEL)
2952 ;
2953 else
2954 gcc_assert (!size || !(PARM_BOUNDARY % BITS_PER_WORD));
2955
2956 mem = validize_mem (copy_rtx (stack_parm));
2957
2958 /* Handle values in multiple non-contiguous locations. */
2959 if (GET_CODE (entry_parm) == PARALLEL && !MEM_P (mem))
2960 emit_group_store (mem, entry_parm, data->passed_type, size);
2961 else if (GET_CODE (entry_parm) == PARALLEL)
2962 {
2963 push_to_sequence2 (all->first_conversion_insn,
2964 all->last_conversion_insn);
2965 emit_group_store (mem, entry_parm, data->passed_type, size);
2966 all->first_conversion_insn = get_insns ();
2967 all->last_conversion_insn = get_last_insn ();
2968 end_sequence ();
2969 in_conversion_seq = true;
2970 }
2971
2972 else if (size == 0)
2973 ;
2974
2975 /* If SIZE is that of a mode no bigger than a word, just use
2976 that mode's store operation. */
2977 else if (size <= UNITS_PER_WORD)
2978 {
2979 machine_mode mode
2980 = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
2981
2982 if (mode != BLKmode
2983 #ifdef BLOCK_REG_PADDING
2984 && (size == UNITS_PER_WORD
2985 || (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2986 != (BYTES_BIG_ENDIAN ? upward : downward)))
2987 #endif
2988 )
2989 {
2990 rtx reg;
2991
2992 /* We are really truncating a word_mode value containing
2993 SIZE bytes into a value of mode MODE. If such an
2994 operation requires no actual instructions, we can refer
2995 to the value directly in mode MODE, otherwise we must
2996 start with the register in word_mode and explicitly
2997 convert it. */
2998 if (TRULY_NOOP_TRUNCATION (size * BITS_PER_UNIT, BITS_PER_WORD))
2999 reg = gen_rtx_REG (mode, REGNO (entry_parm));
3000 else
3001 {
3002 reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
3003 reg = convert_to_mode (mode, copy_to_reg (reg), 1);
3004 }
3005 emit_move_insn (change_address (mem, mode, 0), reg);
3006 }
3007
3008 #ifdef BLOCK_REG_PADDING
3009 /* Storing the register in memory as a full word, as
3010 move_block_from_reg below would do, and then using the
3011 MEM in a smaller mode, has the effect of shifting right
3012 if BYTES_BIG_ENDIAN. If we're bypassing memory, the
3013 shifting must be explicit. */
3014 else if (!MEM_P (mem))
3015 {
3016 rtx x;
3017
3018 /* If the assert below fails, we should have taken the
3019 mode != BLKmode path above, unless we have downward
3020 padding of smaller-than-word arguments on a machine
3021 with little-endian bytes, which would likely require
3022 additional changes to work correctly. */
3023 gcc_checking_assert (BYTES_BIG_ENDIAN
3024 && (BLOCK_REG_PADDING (mode,
3025 data->passed_type, 1)
3026 == upward));
3027
3028 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
3029
3030 x = gen_rtx_REG (word_mode, REGNO (entry_parm));
3031 x = expand_shift (RSHIFT_EXPR, word_mode, x, by,
3032 NULL_RTX, 1);
3033 x = force_reg (word_mode, x);
3034 x = gen_lowpart_SUBREG (GET_MODE (mem), x);
3035
3036 emit_move_insn (mem, x);
3037 }
3038 #endif
3039
3040 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
3041 machine must be aligned to the left before storing
3042 to memory. Note that the previous test doesn't
3043 handle all cases (e.g. SIZE == 3). */
3044 else if (size != UNITS_PER_WORD
3045 #ifdef BLOCK_REG_PADDING
3046 && (BLOCK_REG_PADDING (mode, data->passed_type, 1)
3047 == downward)
3048 #else
3049 && BYTES_BIG_ENDIAN
3050 #endif
3051 )
3052 {
3053 rtx tem, x;
3054 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
3055 rtx reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
3056
3057 x = expand_shift (LSHIFT_EXPR, word_mode, reg, by, NULL_RTX, 1);
3058 tem = change_address (mem, word_mode, 0);
3059 emit_move_insn (tem, x);
3060 }
3061 else
3062 move_block_from_reg (REGNO (entry_parm), mem,
3063 size_stored / UNITS_PER_WORD);
3064 }
3065 else if (!MEM_P (mem))
3066 {
3067 gcc_checking_assert (size > UNITS_PER_WORD);
3068 #ifdef BLOCK_REG_PADDING
3069 gcc_checking_assert (BLOCK_REG_PADDING (GET_MODE (mem),
3070 data->passed_type, 0)
3071 == upward);
3072 #endif
3073 emit_move_insn (mem, entry_parm);
3074 }
3075 else
3076 move_block_from_reg (REGNO (entry_parm), mem,
3077 size_stored / UNITS_PER_WORD);
3078 }
3079 else if (data->stack_parm == 0)
3080 {
3081 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3082 emit_block_move (stack_parm, data->entry_parm, GEN_INT (size),
3083 BLOCK_OP_NORMAL);
3084 all->first_conversion_insn = get_insns ();
3085 all->last_conversion_insn = get_last_insn ();
3086 end_sequence ();
3087 in_conversion_seq = true;
3088 }
3089
3090 if (target_reg)
3091 {
3092 if (!in_conversion_seq)
3093 emit_move_insn (target_reg, stack_parm);
3094 else
3095 {
3096 push_to_sequence2 (all->first_conversion_insn,
3097 all->last_conversion_insn);
3098 emit_move_insn (target_reg, stack_parm);
3099 all->first_conversion_insn = get_insns ();
3100 all->last_conversion_insn = get_last_insn ();
3101 end_sequence ();
3102 }
3103 stack_parm = target_reg;
3104 }
3105
3106 data->stack_parm = stack_parm;
3107 set_parm_rtl (parm, stack_parm);
3108 }
3109
3110 /* A subroutine of assign_parms. Allocate a pseudo to hold the current
3111 parameter. Get it there. Perform all ABI specified conversions. */
3112
3113 static void
3114 assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm,
3115 struct assign_parm_data_one *data)
3116 {
3117 rtx parmreg, validated_mem;
3118 rtx equiv_stack_parm;
3119 machine_mode promoted_nominal_mode;
3120 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (parm));
3121 bool did_conversion = false;
3122 bool need_conversion, moved;
3123 rtx rtl;
3124
3125 /* Store the parm in a pseudoregister during the function, but we may
3126 need to do it in a wider mode. Using 2 here makes the result
3127 consistent with promote_decl_mode and thus expand_expr_real_1. */
3128 promoted_nominal_mode
3129 = promote_function_mode (data->nominal_type, data->nominal_mode, &unsignedp,
3130 TREE_TYPE (current_function_decl), 2);
3131
3132 parmreg = gen_reg_rtx (promoted_nominal_mode);
3133 if (!DECL_ARTIFICIAL (parm))
3134 mark_user_reg (parmreg);
3135
3136 /* If this was an item that we received a pointer to,
3137 set rtl appropriately. */
3138 if (data->passed_pointer)
3139 {
3140 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data->passed_type)), parmreg);
3141 set_mem_attributes (rtl, parm, 1);
3142 }
3143 else
3144 rtl = parmreg;
3145
3146 assign_parm_remove_parallels (data);
3147
3148 /* Copy the value into the register, thus bridging between
3149 assign_parm_find_data_types and expand_expr_real_1. */
3150
3151 equiv_stack_parm = data->stack_parm;
3152 validated_mem = validize_mem (copy_rtx (data->entry_parm));
3153
3154 need_conversion = (data->nominal_mode != data->passed_mode
3155 || promoted_nominal_mode != data->promoted_mode);
3156 moved = false;
3157
3158 if (need_conversion
3159 && GET_MODE_CLASS (data->nominal_mode) == MODE_INT
3160 && data->nominal_mode == data->passed_mode
3161 && data->nominal_mode == GET_MODE (data->entry_parm))
3162 {
3163 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
3164 mode, by the caller. We now have to convert it to
3165 NOMINAL_MODE, if different. However, PARMREG may be in
3166 a different mode than NOMINAL_MODE if it is being stored
3167 promoted.
3168
3169 If ENTRY_PARM is a hard register, it might be in a register
3170 not valid for operating in its mode (e.g., an odd-numbered
3171 register for a DFmode). In that case, moves are the only
3172 thing valid, so we can't do a convert from there. This
3173 occurs when the calling sequence allow such misaligned
3174 usages.
3175
3176 In addition, the conversion may involve a call, which could
3177 clobber parameters which haven't been copied to pseudo
3178 registers yet.
3179
3180 First, we try to emit an insn which performs the necessary
3181 conversion. We verify that this insn does not clobber any
3182 hard registers. */
3183
3184 enum insn_code icode;
3185 rtx op0, op1;
3186
3187 icode = can_extend_p (promoted_nominal_mode, data->passed_mode,
3188 unsignedp);
3189
3190 op0 = parmreg;
3191 op1 = validated_mem;
3192 if (icode != CODE_FOR_nothing
3193 && insn_operand_matches (icode, 0, op0)
3194 && insn_operand_matches (icode, 1, op1))
3195 {
3196 enum rtx_code code = unsignedp ? ZERO_EXTEND : SIGN_EXTEND;
3197 rtx_insn *insn, *insns;
3198 rtx t = op1;
3199 HARD_REG_SET hardregs;
3200
3201 start_sequence ();
3202 /* If op1 is a hard register that is likely spilled, first
3203 force it into a pseudo, otherwise combiner might extend
3204 its lifetime too much. */
3205 if (GET_CODE (t) == SUBREG)
3206 t = SUBREG_REG (t);
3207 if (REG_P (t)
3208 && HARD_REGISTER_P (t)
3209 && ! TEST_HARD_REG_BIT (fixed_reg_set, REGNO (t))
3210 && targetm.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (t))))
3211 {
3212 t = gen_reg_rtx (GET_MODE (op1));
3213 emit_move_insn (t, op1);
3214 }
3215 else
3216 t = op1;
3217 rtx_insn *pat = gen_extend_insn (op0, t, promoted_nominal_mode,
3218 data->passed_mode, unsignedp);
3219 emit_insn (pat);
3220 insns = get_insns ();
3221
3222 moved = true;
3223 CLEAR_HARD_REG_SET (hardregs);
3224 for (insn = insns; insn && moved; insn = NEXT_INSN (insn))
3225 {
3226 if (INSN_P (insn))
3227 note_stores (PATTERN (insn), record_hard_reg_sets,
3228 &hardregs);
3229 if (!hard_reg_set_empty_p (hardregs))
3230 moved = false;
3231 }
3232
3233 end_sequence ();
3234
3235 if (moved)
3236 {
3237 emit_insn (insns);
3238 if (equiv_stack_parm != NULL_RTX)
3239 equiv_stack_parm = gen_rtx_fmt_e (code, GET_MODE (parmreg),
3240 equiv_stack_parm);
3241 }
3242 }
3243 }
3244
3245 if (moved)
3246 /* Nothing to do. */
3247 ;
3248 else if (need_conversion)
3249 {
3250 /* We did not have an insn to convert directly, or the sequence
3251 generated appeared unsafe. We must first copy the parm to a
3252 pseudo reg, and save the conversion until after all
3253 parameters have been moved. */
3254
3255 int save_tree_used;
3256 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
3257
3258 emit_move_insn (tempreg, validated_mem);
3259
3260 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3261 tempreg = convert_to_mode (data->nominal_mode, tempreg, unsignedp);
3262
3263 if (GET_CODE (tempreg) == SUBREG
3264 && GET_MODE (tempreg) == data->nominal_mode
3265 && REG_P (SUBREG_REG (tempreg))
3266 && data->nominal_mode == data->passed_mode
3267 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (data->entry_parm)
3268 && GET_MODE_SIZE (GET_MODE (tempreg))
3269 < GET_MODE_SIZE (GET_MODE (data->entry_parm)))
3270 {
3271 /* The argument is already sign/zero extended, so note it
3272 into the subreg. */
3273 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
3274 SUBREG_PROMOTED_SET (tempreg, unsignedp);
3275 }
3276
3277 /* TREE_USED gets set erroneously during expand_assignment. */
3278 save_tree_used = TREE_USED (parm);
3279 SET_DECL_RTL (parm, rtl);
3280 expand_assignment (parm, make_tree (data->nominal_type, tempreg), false);
3281 SET_DECL_RTL (parm, NULL_RTX);
3282 TREE_USED (parm) = save_tree_used;
3283 all->first_conversion_insn = get_insns ();
3284 all->last_conversion_insn = get_last_insn ();
3285 end_sequence ();
3286
3287 did_conversion = true;
3288 }
3289 else
3290 emit_move_insn (parmreg, validated_mem);
3291
3292 /* If we were passed a pointer but the actual value can safely live
3293 in a register, retrieve it and use it directly. */
3294 if (data->passed_pointer && TYPE_MODE (TREE_TYPE (parm)) != BLKmode)
3295 {
3296 /* We can't use nominal_mode, because it will have been set to
3297 Pmode above. We must use the actual mode of the parm. */
3298 if (use_register_for_decl (parm))
3299 {
3300 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
3301 mark_user_reg (parmreg);
3302 }
3303 else
3304 {
3305 int align = STACK_SLOT_ALIGNMENT (TREE_TYPE (parm),
3306 TYPE_MODE (TREE_TYPE (parm)),
3307 TYPE_ALIGN (TREE_TYPE (parm)));
3308 parmreg
3309 = assign_stack_local (TYPE_MODE (TREE_TYPE (parm)),
3310 GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (parm))),
3311 align);
3312 set_mem_attributes (parmreg, parm, 1);
3313 }
3314
3315 /* We need to preserve an address based on VIRTUAL_STACK_VARS_REGNUM for
3316 the debug info in case it is not legitimate. */
3317 if (GET_MODE (parmreg) != GET_MODE (rtl))
3318 {
3319 rtx tempreg = gen_reg_rtx (GET_MODE (rtl));
3320 int unsigned_p = TYPE_UNSIGNED (TREE_TYPE (parm));
3321
3322 push_to_sequence2 (all->first_conversion_insn,
3323 all->last_conversion_insn);
3324 emit_move_insn (tempreg, rtl);
3325 tempreg = convert_to_mode (GET_MODE (parmreg), tempreg, unsigned_p);
3326 emit_move_insn (MEM_P (parmreg) ? copy_rtx (parmreg) : parmreg,
3327 tempreg);
3328 all->first_conversion_insn = get_insns ();
3329 all->last_conversion_insn = get_last_insn ();
3330 end_sequence ();
3331
3332 did_conversion = true;
3333 }
3334 else
3335 emit_move_insn (MEM_P (parmreg) ? copy_rtx (parmreg) : parmreg, rtl);
3336
3337 rtl = parmreg;
3338
3339 /* STACK_PARM is the pointer, not the parm, and PARMREG is
3340 now the parm. */
3341 data->stack_parm = NULL;
3342 }
3343
3344 set_parm_rtl (parm, rtl);
3345
3346 /* Mark the register as eliminable if we did no conversion and it was
3347 copied from memory at a fixed offset, and the arg pointer was not
3348 copied to a pseudo-reg. If the arg pointer is a pseudo reg or the
3349 offset formed an invalid address, such memory-equivalences as we
3350 make here would screw up life analysis for it. */
3351 if (data->nominal_mode == data->passed_mode
3352 && !did_conversion
3353 && data->stack_parm != 0
3354 && MEM_P (data->stack_parm)
3355 && data->locate.offset.var == 0
3356 && reg_mentioned_p (virtual_incoming_args_rtx,
3357 XEXP (data->stack_parm, 0)))
3358 {
3359 rtx_insn *linsn = get_last_insn ();
3360 rtx_insn *sinsn;
3361 rtx set;
3362
3363 /* Mark complex types separately. */
3364 if (GET_CODE (parmreg) == CONCAT)
3365 {
3366 machine_mode submode
3367 = GET_MODE_INNER (GET_MODE (parmreg));
3368 int regnor = REGNO (XEXP (parmreg, 0));
3369 int regnoi = REGNO (XEXP (parmreg, 1));
3370 rtx stackr = adjust_address_nv (data->stack_parm, submode, 0);
3371 rtx stacki = adjust_address_nv (data->stack_parm, submode,
3372 GET_MODE_SIZE (submode));
3373
3374 /* Scan backwards for the set of the real and
3375 imaginary parts. */
3376 for (sinsn = linsn; sinsn != 0;
3377 sinsn = prev_nonnote_insn (sinsn))
3378 {
3379 set = single_set (sinsn);
3380 if (set == 0)
3381 continue;
3382
3383 if (SET_DEST (set) == regno_reg_rtx [regnoi])
3384 set_unique_reg_note (sinsn, REG_EQUIV, stacki);
3385 else if (SET_DEST (set) == regno_reg_rtx [regnor])
3386 set_unique_reg_note (sinsn, REG_EQUIV, stackr);
3387 }
3388 }
3389 else
3390 set_dst_reg_note (linsn, REG_EQUIV, equiv_stack_parm, parmreg);
3391 }
3392
3393 /* For pointer data type, suggest pointer register. */
3394 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3395 mark_reg_pointer (parmreg,
3396 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
3397 }
3398
3399 /* A subroutine of assign_parms. Allocate stack space to hold the current
3400 parameter. Get it there. Perform all ABI specified conversions. */
3401
3402 static void
3403 assign_parm_setup_stack (struct assign_parm_data_all *all, tree parm,
3404 struct assign_parm_data_one *data)
3405 {
3406 /* Value must be stored in the stack slot STACK_PARM during function
3407 execution. */
3408 bool to_conversion = false;
3409
3410 assign_parm_remove_parallels (data);
3411
3412 if (data->promoted_mode != data->nominal_mode)
3413 {
3414 /* Conversion is required. */
3415 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
3416
3417 emit_move_insn (tempreg, validize_mem (copy_rtx (data->entry_parm)));
3418
3419 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3420 to_conversion = true;
3421
3422 data->entry_parm = convert_to_mode (data->nominal_mode, tempreg,
3423 TYPE_UNSIGNED (TREE_TYPE (parm)));
3424
3425 if (data->stack_parm)
3426 {
3427 int offset = subreg_lowpart_offset (data->nominal_mode,
3428 GET_MODE (data->stack_parm));
3429 /* ??? This may need a big-endian conversion on sparc64. */
3430 data->stack_parm
3431 = adjust_address (data->stack_parm, data->nominal_mode, 0);
3432 if (offset && MEM_OFFSET_KNOWN_P (data->stack_parm))
3433 set_mem_offset (data->stack_parm,
3434 MEM_OFFSET (data->stack_parm) + offset);
3435 }
3436 }
3437
3438 if (data->entry_parm != data->stack_parm)
3439 {
3440 rtx src, dest;
3441
3442 if (data->stack_parm == 0)
3443 {
3444 int align = STACK_SLOT_ALIGNMENT (data->passed_type,
3445 GET_MODE (data->entry_parm),
3446 TYPE_ALIGN (data->passed_type));
3447 data->stack_parm
3448 = assign_stack_local (GET_MODE (data->entry_parm),
3449 GET_MODE_SIZE (GET_MODE (data->entry_parm)),
3450 align);
3451 set_mem_attributes (data->stack_parm, parm, 1);
3452 }
3453
3454 dest = validize_mem (copy_rtx (data->stack_parm));
3455 src = validize_mem (copy_rtx (data->entry_parm));
3456
3457 if (MEM_P (src))
3458 {
3459 /* Use a block move to handle potentially misaligned entry_parm. */
3460 if (!to_conversion)
3461 push_to_sequence2 (all->first_conversion_insn,
3462 all->last_conversion_insn);
3463 to_conversion = true;
3464
3465 emit_block_move (dest, src,
3466 GEN_INT (int_size_in_bytes (data->passed_type)),
3467 BLOCK_OP_NORMAL);
3468 }
3469 else
3470 {
3471 if (!REG_P (src))
3472 src = force_reg (GET_MODE (src), src);
3473 emit_move_insn (dest, src);
3474 }
3475 }
3476
3477 if (to_conversion)
3478 {
3479 all->first_conversion_insn = get_insns ();
3480 all->last_conversion_insn = get_last_insn ();
3481 end_sequence ();
3482 }
3483
3484 set_parm_rtl (parm, data->stack_parm);
3485 }
3486
3487 /* A subroutine of assign_parms. If the ABI splits complex arguments, then
3488 undo the frobbing that we did in assign_parms_augmented_arg_list. */
3489
3490 static void
3491 assign_parms_unsplit_complex (struct assign_parm_data_all *all,
3492 vec<tree> fnargs)
3493 {
3494 tree parm;
3495 tree orig_fnargs = all->orig_fnargs;
3496 unsigned i = 0;
3497
3498 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm), ++i)
3499 {
3500 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
3501 && targetm.calls.split_complex_arg (TREE_TYPE (parm)))
3502 {
3503 rtx tmp, real, imag;
3504 machine_mode inner = GET_MODE_INNER (DECL_MODE (parm));
3505
3506 real = DECL_RTL (fnargs[i]);
3507 imag = DECL_RTL (fnargs[i + 1]);
3508 if (inner != GET_MODE (real))
3509 {
3510 real = gen_lowpart_SUBREG (inner, real);
3511 imag = gen_lowpart_SUBREG (inner, imag);
3512 }
3513
3514 if (TREE_ADDRESSABLE (parm))
3515 {
3516 rtx rmem, imem;
3517 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (parm));
3518 int align = STACK_SLOT_ALIGNMENT (TREE_TYPE (parm),
3519 DECL_MODE (parm),
3520 TYPE_ALIGN (TREE_TYPE (parm)));
3521
3522 /* split_complex_arg put the real and imag parts in
3523 pseudos. Move them to memory. */
3524 tmp = assign_stack_local (DECL_MODE (parm), size, align);
3525 set_mem_attributes (tmp, parm, 1);
3526 rmem = adjust_address_nv (tmp, inner, 0);
3527 imem = adjust_address_nv (tmp, inner, GET_MODE_SIZE (inner));
3528 push_to_sequence2 (all->first_conversion_insn,
3529 all->last_conversion_insn);
3530 emit_move_insn (rmem, real);
3531 emit_move_insn (imem, imag);
3532 all->first_conversion_insn = get_insns ();
3533 all->last_conversion_insn = get_last_insn ();
3534 end_sequence ();
3535 }
3536 else
3537 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
3538 set_parm_rtl (parm, tmp);
3539
3540 real = DECL_INCOMING_RTL (fnargs[i]);
3541 imag = DECL_INCOMING_RTL (fnargs[i + 1]);
3542 if (inner != GET_MODE (real))
3543 {
3544 real = gen_lowpart_SUBREG (inner, real);
3545 imag = gen_lowpart_SUBREG (inner, imag);
3546 }
3547 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
3548 set_decl_incoming_rtl (parm, tmp, false);
3549 i++;
3550 }
3551 }
3552 }
3553
3554 /* Load bounds of PARM from bounds table. */
3555 static void
3556 assign_parm_load_bounds (struct assign_parm_data_one *data,
3557 tree parm,
3558 rtx entry,
3559 unsigned bound_no)
3560 {
3561 bitmap_iterator bi;
3562 unsigned i, offs = 0;
3563 int bnd_no = -1;
3564 rtx slot = NULL, ptr = NULL;
3565
3566 if (parm)
3567 {
3568 bitmap slots;
3569 bitmap_obstack_initialize (NULL);
3570 slots = BITMAP_ALLOC (NULL);
3571 chkp_find_bound_slots (TREE_TYPE (parm), slots);
3572 EXECUTE_IF_SET_IN_BITMAP (slots, 0, i, bi)
3573 {
3574 if (bound_no)
3575 bound_no--;
3576 else
3577 {
3578 bnd_no = i;
3579 break;
3580 }
3581 }
3582 BITMAP_FREE (slots);
3583 bitmap_obstack_release (NULL);
3584 }
3585
3586 /* We may have bounds not associated with any pointer. */
3587 if (bnd_no != -1)
3588 offs = bnd_no * POINTER_SIZE / BITS_PER_UNIT;
3589
3590 /* Find associated pointer. */
3591 if (bnd_no == -1)
3592 {
3593 /* If bounds are not associated with any bounds,
3594 then it is passed in a register or special slot. */
3595 gcc_assert (data->entry_parm);
3596 ptr = const0_rtx;
3597 }
3598 else if (MEM_P (entry))
3599 slot = adjust_address (entry, Pmode, offs);
3600 else if (REG_P (entry))
3601 ptr = gen_rtx_REG (Pmode, REGNO (entry) + bnd_no);
3602 else if (GET_CODE (entry) == PARALLEL)
3603 ptr = chkp_get_value_with_offs (entry, GEN_INT (offs));
3604 else
3605 gcc_unreachable ();
3606 data->entry_parm = targetm.calls.load_bounds_for_arg (slot, ptr,
3607 data->entry_parm);
3608 }
3609
3610 /* Assign RTL expressions to the function's bounds parameters BNDARGS. */
3611
3612 static void
3613 assign_bounds (vec<bounds_parm_data> &bndargs,
3614 struct assign_parm_data_all &all,
3615 bool assign_regs, bool assign_special,
3616 bool assign_bt)
3617 {
3618 unsigned i, pass;
3619 bounds_parm_data *pbdata;
3620
3621 if (!bndargs.exists ())
3622 return;
3623
3624 /* We make few passes to store input bounds. Firstly handle bounds
3625 passed in registers. After that we load bounds passed in special
3626 slots. Finally we load bounds from Bounds Table. */
3627 for (pass = 0; pass < 3; pass++)
3628 FOR_EACH_VEC_ELT (bndargs, i, pbdata)
3629 {
3630 /* Pass 0 => regs only. */
3631 if (pass == 0
3632 && (!assign_regs
3633 ||(!pbdata->parm_data.entry_parm
3634 || GET_CODE (pbdata->parm_data.entry_parm) != REG)))
3635 continue;
3636 /* Pass 1 => slots only. */
3637 else if (pass == 1
3638 && (!assign_special
3639 || (!pbdata->parm_data.entry_parm
3640 || GET_CODE (pbdata->parm_data.entry_parm) == REG)))
3641 continue;
3642 /* Pass 2 => BT only. */
3643 else if (pass == 2
3644 && (!assign_bt
3645 || pbdata->parm_data.entry_parm))
3646 continue;
3647
3648 if (!pbdata->parm_data.entry_parm
3649 || GET_CODE (pbdata->parm_data.entry_parm) != REG)
3650 assign_parm_load_bounds (&pbdata->parm_data, pbdata->ptr_parm,
3651 pbdata->ptr_entry, pbdata->bound_no);
3652
3653 set_decl_incoming_rtl (pbdata->bounds_parm,
3654 pbdata->parm_data.entry_parm, false);
3655
3656 if (assign_parm_setup_block_p (&pbdata->parm_data))
3657 assign_parm_setup_block (&all, pbdata->bounds_parm,
3658 &pbdata->parm_data);
3659 else if (pbdata->parm_data.passed_pointer
3660 || use_register_for_decl (pbdata->bounds_parm))
3661 assign_parm_setup_reg (&all, pbdata->bounds_parm,
3662 &pbdata->parm_data);
3663 else
3664 assign_parm_setup_stack (&all, pbdata->bounds_parm,
3665 &pbdata->parm_data);
3666 }
3667 }
3668
3669 /* Assign RTL expressions to the function's parameters. This may involve
3670 copying them into registers and using those registers as the DECL_RTL. */
3671
3672 static void
3673 assign_parms (tree fndecl)
3674 {
3675 struct assign_parm_data_all all;
3676 tree parm;
3677 vec<tree> fnargs;
3678 unsigned i, bound_no = 0;
3679 tree last_arg = NULL;
3680 rtx last_arg_entry = NULL;
3681 vec<bounds_parm_data> bndargs = vNULL;
3682 bounds_parm_data bdata;
3683
3684 crtl->args.internal_arg_pointer
3685 = targetm.calls.internal_arg_pointer ();
3686
3687 assign_parms_initialize_all (&all);
3688 fnargs = assign_parms_augmented_arg_list (&all);
3689
3690 FOR_EACH_VEC_ELT (fnargs, i, parm)
3691 {
3692 struct assign_parm_data_one data;
3693
3694 /* Extract the type of PARM; adjust it according to ABI. */
3695 assign_parm_find_data_types (&all, parm, &data);
3696
3697 /* Early out for errors and void parameters. */
3698 if (data.passed_mode == VOIDmode)
3699 {
3700 SET_DECL_RTL (parm, const0_rtx);
3701 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
3702 continue;
3703 }
3704
3705 /* Estimate stack alignment from parameter alignment. */
3706 if (SUPPORTS_STACK_ALIGNMENT)
3707 {
3708 unsigned int align
3709 = targetm.calls.function_arg_boundary (data.promoted_mode,
3710 data.passed_type);
3711 align = MINIMUM_ALIGNMENT (data.passed_type, data.promoted_mode,
3712 align);
3713 if (TYPE_ALIGN (data.nominal_type) > align)
3714 align = MINIMUM_ALIGNMENT (data.nominal_type,
3715 TYPE_MODE (data.nominal_type),
3716 TYPE_ALIGN (data.nominal_type));
3717 if (crtl->stack_alignment_estimated < align)
3718 {
3719 gcc_assert (!crtl->stack_realign_processed);
3720 crtl->stack_alignment_estimated = align;
3721 }
3722 }
3723
3724 /* Find out where the parameter arrives in this function. */
3725 assign_parm_find_entry_rtl (&all, &data);
3726
3727 /* Find out where stack space for this parameter might be. */
3728 if (assign_parm_is_stack_parm (&all, &data))
3729 {
3730 assign_parm_find_stack_rtl (parm, &data);
3731 assign_parm_adjust_entry_rtl (&data);
3732 }
3733 if (!POINTER_BOUNDS_TYPE_P (data.passed_type))
3734 {
3735 /* Remember where last non bounds arg was passed in case
3736 we have to load associated bounds for it from Bounds
3737 Table. */
3738 last_arg = parm;
3739 last_arg_entry = data.entry_parm;
3740 bound_no = 0;
3741 }
3742 /* Record permanently how this parm was passed. */
3743 if (data.passed_pointer)
3744 {
3745 rtx incoming_rtl
3746 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data.passed_type)),
3747 data.entry_parm);
3748 set_decl_incoming_rtl (parm, incoming_rtl, true);
3749 }
3750 else
3751 set_decl_incoming_rtl (parm, data.entry_parm, false);
3752
3753 assign_parm_adjust_stack_rtl (&data);
3754
3755 /* Bounds should be loaded in the particular order to
3756 have registers allocated correctly. Collect info about
3757 input bounds and load them later. */
3758 if (POINTER_BOUNDS_TYPE_P (data.passed_type))
3759 {
3760 /* Expect bounds in instrumented functions only. */
3761 gcc_assert (chkp_function_instrumented_p (fndecl));
3762
3763 bdata.parm_data = data;
3764 bdata.bounds_parm = parm;
3765 bdata.ptr_parm = last_arg;
3766 bdata.ptr_entry = last_arg_entry;
3767 bdata.bound_no = bound_no;
3768 bndargs.safe_push (bdata);
3769 }
3770 else
3771 {
3772 if (assign_parm_setup_block_p (&data))
3773 assign_parm_setup_block (&all, parm, &data);
3774 else if (data.passed_pointer || use_register_for_decl (parm))
3775 assign_parm_setup_reg (&all, parm, &data);
3776 else
3777 assign_parm_setup_stack (&all, parm, &data);
3778 }
3779
3780 if (cfun->stdarg && !DECL_CHAIN (parm))
3781 {
3782 int pretend_bytes = 0;
3783
3784 assign_parms_setup_varargs (&all, &data, false);
3785
3786 if (chkp_function_instrumented_p (fndecl))
3787 {
3788 /* We expect this is the last parm. Otherwise it is wrong
3789 to assign bounds right now. */
3790 gcc_assert (i == (fnargs.length () - 1));
3791 assign_bounds (bndargs, all, true, false, false);
3792 targetm.calls.setup_incoming_vararg_bounds (all.args_so_far,
3793 data.promoted_mode,
3794 data.passed_type,
3795 &pretend_bytes,
3796 false);
3797 assign_bounds (bndargs, all, false, true, true);
3798 bndargs.release ();
3799 }
3800 }
3801
3802 /* Update info on where next arg arrives in registers. */
3803 targetm.calls.function_arg_advance (all.args_so_far, data.promoted_mode,
3804 data.passed_type, data.named_arg);
3805
3806 if (POINTER_BOUNDS_TYPE_P (data.passed_type))
3807 bound_no++;
3808 }
3809
3810 assign_bounds (bndargs, all, true, true, true);
3811 bndargs.release ();
3812
3813 if (targetm.calls.split_complex_arg)
3814 assign_parms_unsplit_complex (&all, fnargs);
3815
3816 fnargs.release ();
3817
3818 /* Output all parameter conversion instructions (possibly including calls)
3819 now that all parameters have been copied out of hard registers. */
3820 emit_insn (all.first_conversion_insn);
3821
3822 /* Estimate reload stack alignment from scalar return mode. */
3823 if (SUPPORTS_STACK_ALIGNMENT)
3824 {
3825 if (DECL_RESULT (fndecl))
3826 {
3827 tree type = TREE_TYPE (DECL_RESULT (fndecl));
3828 machine_mode mode = TYPE_MODE (type);
3829
3830 if (mode != BLKmode
3831 && mode != VOIDmode
3832 && !AGGREGATE_TYPE_P (type))
3833 {
3834 unsigned int align = GET_MODE_ALIGNMENT (mode);
3835 if (crtl->stack_alignment_estimated < align)
3836 {
3837 gcc_assert (!crtl->stack_realign_processed);
3838 crtl->stack_alignment_estimated = align;
3839 }
3840 }
3841 }
3842 }
3843
3844 /* If we are receiving a struct value address as the first argument, set up
3845 the RTL for the function result. As this might require code to convert
3846 the transmitted address to Pmode, we do this here to ensure that possible
3847 preliminary conversions of the address have been emitted already. */
3848 if (all.function_result_decl)
3849 {
3850 tree result = DECL_RESULT (current_function_decl);
3851 rtx addr = DECL_RTL (all.function_result_decl);
3852 rtx x;
3853
3854 if (DECL_BY_REFERENCE (result))
3855 {
3856 SET_DECL_VALUE_EXPR (result, all.function_result_decl);
3857 x = addr;
3858 }
3859 else
3860 {
3861 SET_DECL_VALUE_EXPR (result,
3862 build1 (INDIRECT_REF, TREE_TYPE (result),
3863 all.function_result_decl));
3864 addr = convert_memory_address (Pmode, addr);
3865 x = gen_rtx_MEM (DECL_MODE (result), addr);
3866 set_mem_attributes (x, result, 1);
3867 }
3868
3869 DECL_HAS_VALUE_EXPR_P (result) = 1;
3870
3871 set_parm_rtl (result, x);
3872 }
3873
3874 /* We have aligned all the args, so add space for the pretend args. */
3875 crtl->args.pretend_args_size = all.pretend_args_size;
3876 all.stack_args_size.constant += all.extra_pretend_bytes;
3877 crtl->args.size = all.stack_args_size.constant;
3878
3879 /* Adjust function incoming argument size for alignment and
3880 minimum length. */
3881
3882 crtl->args.size = MAX (crtl->args.size, all.reg_parm_stack_space);
3883 crtl->args.size = CEIL_ROUND (crtl->args.size,
3884 PARM_BOUNDARY / BITS_PER_UNIT);
3885
3886 if (ARGS_GROW_DOWNWARD)
3887 {
3888 crtl->args.arg_offset_rtx
3889 = (all.stack_args_size.var == 0 ? GEN_INT (-all.stack_args_size.constant)
3890 : expand_expr (size_diffop (all.stack_args_size.var,
3891 size_int (-all.stack_args_size.constant)),
3892 NULL_RTX, VOIDmode, EXPAND_NORMAL));
3893 }
3894 else
3895 crtl->args.arg_offset_rtx = ARGS_SIZE_RTX (all.stack_args_size);
3896
3897 /* See how many bytes, if any, of its args a function should try to pop
3898 on return. */
3899
3900 crtl->args.pops_args = targetm.calls.return_pops_args (fndecl,
3901 TREE_TYPE (fndecl),
3902 crtl->args.size);
3903
3904 /* For stdarg.h function, save info about
3905 regs and stack space used by the named args. */
3906
3907 crtl->args.info = all.args_so_far_v;
3908
3909 /* Set the rtx used for the function return value. Put this in its
3910 own variable so any optimizers that need this information don't have
3911 to include tree.h. Do this here so it gets done when an inlined
3912 function gets output. */
3913
3914 crtl->return_rtx
3915 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
3916 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
3917
3918 /* If scalar return value was computed in a pseudo-reg, or was a named
3919 return value that got dumped to the stack, copy that to the hard
3920 return register. */
3921 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
3922 {
3923 tree decl_result = DECL_RESULT (fndecl);
3924 rtx decl_rtl = DECL_RTL (decl_result);
3925
3926 if (REG_P (decl_rtl)
3927 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
3928 : DECL_REGISTER (decl_result))
3929 {
3930 rtx real_decl_rtl;
3931
3932 real_decl_rtl = targetm.calls.function_value (TREE_TYPE (decl_result),
3933 fndecl, true);
3934 if (chkp_function_instrumented_p (fndecl))
3935 crtl->return_bnd
3936 = targetm.calls.chkp_function_value_bounds (TREE_TYPE (decl_result),
3937 fndecl, true);
3938 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
3939 /* The delay slot scheduler assumes that crtl->return_rtx
3940 holds the hard register containing the return value, not a
3941 temporary pseudo. */
3942 crtl->return_rtx = real_decl_rtl;
3943 }
3944 }
3945 }
3946
3947 /* A subroutine of gimplify_parameters, invoked via walk_tree.
3948 For all seen types, gimplify their sizes. */
3949
3950 static tree
3951 gimplify_parm_type (tree *tp, int *walk_subtrees, void *data)
3952 {
3953 tree t = *tp;
3954
3955 *walk_subtrees = 0;
3956 if (TYPE_P (t))
3957 {
3958 if (POINTER_TYPE_P (t))
3959 *walk_subtrees = 1;
3960 else if (TYPE_SIZE (t) && !TREE_CONSTANT (TYPE_SIZE (t))
3961 && !TYPE_SIZES_GIMPLIFIED (t))
3962 {
3963 gimplify_type_sizes (t, (gimple_seq *) data);
3964 *walk_subtrees = 1;
3965 }
3966 }
3967
3968 return NULL;
3969 }
3970
3971 /* Gimplify the parameter list for current_function_decl. This involves
3972 evaluating SAVE_EXPRs of variable sized parameters and generating code
3973 to implement callee-copies reference parameters. Returns a sequence of
3974 statements to add to the beginning of the function. */
3975
3976 gimple_seq
3977 gimplify_parameters (void)
3978 {
3979 struct assign_parm_data_all all;
3980 tree parm;
3981 gimple_seq stmts = NULL;
3982 vec<tree> fnargs;
3983 unsigned i;
3984
3985 assign_parms_initialize_all (&all);
3986 fnargs = assign_parms_augmented_arg_list (&all);
3987
3988 FOR_EACH_VEC_ELT (fnargs, i, parm)
3989 {
3990 struct assign_parm_data_one data;
3991
3992 /* Extract the type of PARM; adjust it according to ABI. */
3993 assign_parm_find_data_types (&all, parm, &data);
3994
3995 /* Early out for errors and void parameters. */
3996 if (data.passed_mode == VOIDmode || DECL_SIZE (parm) == NULL)
3997 continue;
3998
3999 /* Update info on where next arg arrives in registers. */
4000 targetm.calls.function_arg_advance (all.args_so_far, data.promoted_mode,
4001 data.passed_type, data.named_arg);
4002
4003 /* ??? Once upon a time variable_size stuffed parameter list
4004 SAVE_EXPRs (amongst others) onto a pending sizes list. This
4005 turned out to be less than manageable in the gimple world.
4006 Now we have to hunt them down ourselves. */
4007 walk_tree_without_duplicates (&data.passed_type,
4008 gimplify_parm_type, &stmts);
4009
4010 if (TREE_CODE (DECL_SIZE_UNIT (parm)) != INTEGER_CST)
4011 {
4012 gimplify_one_sizepos (&DECL_SIZE (parm), &stmts);
4013 gimplify_one_sizepos (&DECL_SIZE_UNIT (parm), &stmts);
4014 }
4015
4016 if (data.passed_pointer)
4017 {
4018 tree type = TREE_TYPE (data.passed_type);
4019 if (reference_callee_copied (&all.args_so_far_v, TYPE_MODE (type),
4020 type, data.named_arg))
4021 {
4022 tree local, t;
4023
4024 /* For constant-sized objects, this is trivial; for
4025 variable-sized objects, we have to play games. */
4026 if (TREE_CODE (DECL_SIZE_UNIT (parm)) == INTEGER_CST
4027 && !(flag_stack_check == GENERIC_STACK_CHECK
4028 && compare_tree_int (DECL_SIZE_UNIT (parm),
4029 STACK_CHECK_MAX_VAR_SIZE) > 0))
4030 {
4031 local = create_tmp_var (type, get_name (parm));
4032 DECL_IGNORED_P (local) = 0;
4033 /* If PARM was addressable, move that flag over
4034 to the local copy, as its address will be taken,
4035 not the PARMs. Keep the parms address taken
4036 as we'll query that flag during gimplification. */
4037 if (TREE_ADDRESSABLE (parm))
4038 TREE_ADDRESSABLE (local) = 1;
4039 else if (TREE_CODE (type) == COMPLEX_TYPE
4040 || TREE_CODE (type) == VECTOR_TYPE)
4041 DECL_GIMPLE_REG_P (local) = 1;
4042 }
4043 else
4044 {
4045 tree ptr_type, addr;
4046
4047 ptr_type = build_pointer_type (type);
4048 addr = create_tmp_reg (ptr_type, get_name (parm));
4049 DECL_IGNORED_P (addr) = 0;
4050 local = build_fold_indirect_ref (addr);
4051
4052 t = builtin_decl_explicit (BUILT_IN_ALLOCA_WITH_ALIGN);
4053 t = build_call_expr (t, 2, DECL_SIZE_UNIT (parm),
4054 size_int (DECL_ALIGN (parm)));
4055
4056 /* The call has been built for a variable-sized object. */
4057 CALL_ALLOCA_FOR_VAR_P (t) = 1;
4058 t = fold_convert (ptr_type, t);
4059 t = build2 (MODIFY_EXPR, TREE_TYPE (addr), addr, t);
4060 gimplify_and_add (t, &stmts);
4061 }
4062
4063 gimplify_assign (local, parm, &stmts);
4064
4065 SET_DECL_VALUE_EXPR (parm, local);
4066 DECL_HAS_VALUE_EXPR_P (parm) = 1;
4067 }
4068 }
4069 }
4070
4071 fnargs.release ();
4072
4073 return stmts;
4074 }
4075 \f
4076 /* Compute the size and offset from the start of the stacked arguments for a
4077 parm passed in mode PASSED_MODE and with type TYPE.
4078
4079 INITIAL_OFFSET_PTR points to the current offset into the stacked
4080 arguments.
4081
4082 The starting offset and size for this parm are returned in
4083 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
4084 nonzero, the offset is that of stack slot, which is returned in
4085 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
4086 padding required from the initial offset ptr to the stack slot.
4087
4088 IN_REGS is nonzero if the argument will be passed in registers. It will
4089 never be set if REG_PARM_STACK_SPACE is not defined.
4090
4091 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
4092 for arguments which are passed in registers.
4093
4094 FNDECL is the function in which the argument was defined.
4095
4096 There are two types of rounding that are done. The first, controlled by
4097 TARGET_FUNCTION_ARG_BOUNDARY, forces the offset from the start of the
4098 argument list to be aligned to the specific boundary (in bits). This
4099 rounding affects the initial and starting offsets, but not the argument
4100 size.
4101
4102 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
4103 optionally rounds the size of the parm to PARM_BOUNDARY. The
4104 initial offset is not affected by this rounding, while the size always
4105 is and the starting offset may be. */
4106
4107 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
4108 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
4109 callers pass in the total size of args so far as
4110 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
4111
4112 void
4113 locate_and_pad_parm (machine_mode passed_mode, tree type, int in_regs,
4114 int reg_parm_stack_space, int partial,
4115 tree fndecl ATTRIBUTE_UNUSED,
4116 struct args_size *initial_offset_ptr,
4117 struct locate_and_pad_arg_data *locate)
4118 {
4119 tree sizetree;
4120 enum direction where_pad;
4121 unsigned int boundary, round_boundary;
4122 int part_size_in_regs;
4123
4124 /* If we have found a stack parm before we reach the end of the
4125 area reserved for registers, skip that area. */
4126 if (! in_regs)
4127 {
4128 if (reg_parm_stack_space > 0)
4129 {
4130 if (initial_offset_ptr->var)
4131 {
4132 initial_offset_ptr->var
4133 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
4134 ssize_int (reg_parm_stack_space));
4135 initial_offset_ptr->constant = 0;
4136 }
4137 else if (initial_offset_ptr->constant < reg_parm_stack_space)
4138 initial_offset_ptr->constant = reg_parm_stack_space;
4139 }
4140 }
4141
4142 part_size_in_regs = (reg_parm_stack_space == 0 ? partial : 0);
4143
4144 sizetree
4145 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
4146 where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
4147 boundary = targetm.calls.function_arg_boundary (passed_mode, type);
4148 round_boundary = targetm.calls.function_arg_round_boundary (passed_mode,
4149 type);
4150 locate->where_pad = where_pad;
4151
4152 /* Alignment can't exceed MAX_SUPPORTED_STACK_ALIGNMENT. */
4153 if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
4154 boundary = MAX_SUPPORTED_STACK_ALIGNMENT;
4155
4156 locate->boundary = boundary;
4157
4158 if (SUPPORTS_STACK_ALIGNMENT)
4159 {
4160 /* stack_alignment_estimated can't change after stack has been
4161 realigned. */
4162 if (crtl->stack_alignment_estimated < boundary)
4163 {
4164 if (!crtl->stack_realign_processed)
4165 crtl->stack_alignment_estimated = boundary;
4166 else
4167 {
4168 /* If stack is realigned and stack alignment value
4169 hasn't been finalized, it is OK not to increase
4170 stack_alignment_estimated. The bigger alignment
4171 requirement is recorded in stack_alignment_needed
4172 below. */
4173 gcc_assert (!crtl->stack_realign_finalized
4174 && crtl->stack_realign_needed);
4175 }
4176 }
4177 }
4178
4179 /* Remember if the outgoing parameter requires extra alignment on the
4180 calling function side. */
4181 if (crtl->stack_alignment_needed < boundary)
4182 crtl->stack_alignment_needed = boundary;
4183 if (crtl->preferred_stack_boundary < boundary)
4184 crtl->preferred_stack_boundary = boundary;
4185
4186 if (ARGS_GROW_DOWNWARD)
4187 {
4188 locate->slot_offset.constant = -initial_offset_ptr->constant;
4189 if (initial_offset_ptr->var)
4190 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
4191 initial_offset_ptr->var);
4192
4193 {
4194 tree s2 = sizetree;
4195 if (where_pad != none
4196 && (!tree_fits_uhwi_p (sizetree)
4197 || (tree_to_uhwi (sizetree) * BITS_PER_UNIT) % round_boundary))
4198 s2 = round_up (s2, round_boundary / BITS_PER_UNIT);
4199 SUB_PARM_SIZE (locate->slot_offset, s2);
4200 }
4201
4202 locate->slot_offset.constant += part_size_in_regs;
4203
4204 if (!in_regs || reg_parm_stack_space > 0)
4205 pad_to_arg_alignment (&locate->slot_offset, boundary,
4206 &locate->alignment_pad);
4207
4208 locate->size.constant = (-initial_offset_ptr->constant
4209 - locate->slot_offset.constant);
4210 if (initial_offset_ptr->var)
4211 locate->size.var = size_binop (MINUS_EXPR,
4212 size_binop (MINUS_EXPR,
4213 ssize_int (0),
4214 initial_offset_ptr->var),
4215 locate->slot_offset.var);
4216
4217 /* Pad_below needs the pre-rounded size to know how much to pad
4218 below. */
4219 locate->offset = locate->slot_offset;
4220 if (where_pad == downward)
4221 pad_below (&locate->offset, passed_mode, sizetree);
4222
4223 }
4224 else
4225 {
4226 if (!in_regs || reg_parm_stack_space > 0)
4227 pad_to_arg_alignment (initial_offset_ptr, boundary,
4228 &locate->alignment_pad);
4229 locate->slot_offset = *initial_offset_ptr;
4230
4231 #ifdef PUSH_ROUNDING
4232 if (passed_mode != BLKmode)
4233 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
4234 #endif
4235
4236 /* Pad_below needs the pre-rounded size to know how much to pad below
4237 so this must be done before rounding up. */
4238 locate->offset = locate->slot_offset;
4239 if (where_pad == downward)
4240 pad_below (&locate->offset, passed_mode, sizetree);
4241
4242 if (where_pad != none
4243 && (!tree_fits_uhwi_p (sizetree)
4244 || (tree_to_uhwi (sizetree) * BITS_PER_UNIT) % round_boundary))
4245 sizetree = round_up (sizetree, round_boundary / BITS_PER_UNIT);
4246
4247 ADD_PARM_SIZE (locate->size, sizetree);
4248
4249 locate->size.constant -= part_size_in_regs;
4250 }
4251
4252 #ifdef FUNCTION_ARG_OFFSET
4253 locate->offset.constant += FUNCTION_ARG_OFFSET (passed_mode, type);
4254 #endif
4255 }
4256
4257 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
4258 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
4259
4260 static void
4261 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
4262 struct args_size *alignment_pad)
4263 {
4264 tree save_var = NULL_TREE;
4265 HOST_WIDE_INT save_constant = 0;
4266 int boundary_in_bytes = boundary / BITS_PER_UNIT;
4267 HOST_WIDE_INT sp_offset = STACK_POINTER_OFFSET;
4268
4269 #ifdef SPARC_STACK_BOUNDARY_HACK
4270 /* ??? The SPARC port may claim a STACK_BOUNDARY higher than
4271 the real alignment of %sp. However, when it does this, the
4272 alignment of %sp+STACK_POINTER_OFFSET is STACK_BOUNDARY. */
4273 if (SPARC_STACK_BOUNDARY_HACK)
4274 sp_offset = 0;
4275 #endif
4276
4277 if (boundary > PARM_BOUNDARY)
4278 {
4279 save_var = offset_ptr->var;
4280 save_constant = offset_ptr->constant;
4281 }
4282
4283 alignment_pad->var = NULL_TREE;
4284 alignment_pad->constant = 0;
4285
4286 if (boundary > BITS_PER_UNIT)
4287 {
4288 if (offset_ptr->var)
4289 {
4290 tree sp_offset_tree = ssize_int (sp_offset);
4291 tree offset = size_binop (PLUS_EXPR,
4292 ARGS_SIZE_TREE (*offset_ptr),
4293 sp_offset_tree);
4294 tree rounded;
4295 if (ARGS_GROW_DOWNWARD)
4296 rounded = round_down (offset, boundary / BITS_PER_UNIT);
4297 else
4298 rounded = round_up (offset, boundary / BITS_PER_UNIT);
4299
4300 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
4301 /* ARGS_SIZE_TREE includes constant term. */
4302 offset_ptr->constant = 0;
4303 if (boundary > PARM_BOUNDARY)
4304 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
4305 save_var);
4306 }
4307 else
4308 {
4309 offset_ptr->constant = -sp_offset +
4310 (ARGS_GROW_DOWNWARD
4311 ? FLOOR_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes)
4312 : CEIL_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes));
4313
4314 if (boundary > PARM_BOUNDARY)
4315 alignment_pad->constant = offset_ptr->constant - save_constant;
4316 }
4317 }
4318 }
4319
4320 static void
4321 pad_below (struct args_size *offset_ptr, machine_mode passed_mode, tree sizetree)
4322 {
4323 if (passed_mode != BLKmode)
4324 {
4325 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
4326 offset_ptr->constant
4327 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
4328 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
4329 - GET_MODE_SIZE (passed_mode));
4330 }
4331 else
4332 {
4333 if (TREE_CODE (sizetree) != INTEGER_CST
4334 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
4335 {
4336 /* Round the size up to multiple of PARM_BOUNDARY bits. */
4337 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
4338 /* Add it in. */
4339 ADD_PARM_SIZE (*offset_ptr, s2);
4340 SUB_PARM_SIZE (*offset_ptr, sizetree);
4341 }
4342 }
4343 }
4344 \f
4345
4346 /* True if register REGNO was alive at a place where `setjmp' was
4347 called and was set more than once or is an argument. Such regs may
4348 be clobbered by `longjmp'. */
4349
4350 static bool
4351 regno_clobbered_at_setjmp (bitmap setjmp_crosses, int regno)
4352 {
4353 /* There appear to be cases where some local vars never reach the
4354 backend but have bogus regnos. */
4355 if (regno >= max_reg_num ())
4356 return false;
4357
4358 return ((REG_N_SETS (regno) > 1
4359 || REGNO_REG_SET_P (df_get_live_out (ENTRY_BLOCK_PTR_FOR_FN (cfun)),
4360 regno))
4361 && REGNO_REG_SET_P (setjmp_crosses, regno));
4362 }
4363
4364 /* Walk the tree of blocks describing the binding levels within a
4365 function and warn about variables the might be killed by setjmp or
4366 vfork. This is done after calling flow_analysis before register
4367 allocation since that will clobber the pseudo-regs to hard
4368 regs. */
4369
4370 static void
4371 setjmp_vars_warning (bitmap setjmp_crosses, tree block)
4372 {
4373 tree decl, sub;
4374
4375 for (decl = BLOCK_VARS (block); decl; decl = DECL_CHAIN (decl))
4376 {
4377 if (TREE_CODE (decl) == VAR_DECL
4378 && DECL_RTL_SET_P (decl)
4379 && REG_P (DECL_RTL (decl))
4380 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
4381 warning (OPT_Wclobbered, "variable %q+D might be clobbered by"
4382 " %<longjmp%> or %<vfork%>", decl);
4383 }
4384
4385 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = BLOCK_CHAIN (sub))
4386 setjmp_vars_warning (setjmp_crosses, sub);
4387 }
4388
4389 /* Do the appropriate part of setjmp_vars_warning
4390 but for arguments instead of local variables. */
4391
4392 static void
4393 setjmp_args_warning (bitmap setjmp_crosses)
4394 {
4395 tree decl;
4396 for (decl = DECL_ARGUMENTS (current_function_decl);
4397 decl; decl = DECL_CHAIN (decl))
4398 if (DECL_RTL (decl) != 0
4399 && REG_P (DECL_RTL (decl))
4400 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
4401 warning (OPT_Wclobbered,
4402 "argument %q+D might be clobbered by %<longjmp%> or %<vfork%>",
4403 decl);
4404 }
4405
4406 /* Generate warning messages for variables live across setjmp. */
4407
4408 void
4409 generate_setjmp_warnings (void)
4410 {
4411 bitmap setjmp_crosses = regstat_get_setjmp_crosses ();
4412
4413 if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS
4414 || bitmap_empty_p (setjmp_crosses))
4415 return;
4416
4417 setjmp_vars_warning (setjmp_crosses, DECL_INITIAL (current_function_decl));
4418 setjmp_args_warning (setjmp_crosses);
4419 }
4420
4421 \f
4422 /* Reverse the order of elements in the fragment chain T of blocks,
4423 and return the new head of the chain (old last element).
4424 In addition to that clear BLOCK_SAME_RANGE flags when needed
4425 and adjust BLOCK_SUPERCONTEXT from the super fragment to
4426 its super fragment origin. */
4427
4428 static tree
4429 block_fragments_nreverse (tree t)
4430 {
4431 tree prev = 0, block, next, prev_super = 0;
4432 tree super = BLOCK_SUPERCONTEXT (t);
4433 if (BLOCK_FRAGMENT_ORIGIN (super))
4434 super = BLOCK_FRAGMENT_ORIGIN (super);
4435 for (block = t; block; block = next)
4436 {
4437 next = BLOCK_FRAGMENT_CHAIN (block);
4438 BLOCK_FRAGMENT_CHAIN (block) = prev;
4439 if ((prev && !BLOCK_SAME_RANGE (prev))
4440 || (BLOCK_FRAGMENT_CHAIN (BLOCK_SUPERCONTEXT (block))
4441 != prev_super))
4442 BLOCK_SAME_RANGE (block) = 0;
4443 prev_super = BLOCK_SUPERCONTEXT (block);
4444 BLOCK_SUPERCONTEXT (block) = super;
4445 prev = block;
4446 }
4447 t = BLOCK_FRAGMENT_ORIGIN (t);
4448 if (BLOCK_FRAGMENT_CHAIN (BLOCK_SUPERCONTEXT (t))
4449 != prev_super)
4450 BLOCK_SAME_RANGE (t) = 0;
4451 BLOCK_SUPERCONTEXT (t) = super;
4452 return prev;
4453 }
4454
4455 /* Reverse the order of elements in the chain T of blocks,
4456 and return the new head of the chain (old last element).
4457 Also do the same on subblocks and reverse the order of elements
4458 in BLOCK_FRAGMENT_CHAIN as well. */
4459
4460 static tree
4461 blocks_nreverse_all (tree t)
4462 {
4463 tree prev = 0, block, next;
4464 for (block = t; block; block = next)
4465 {
4466 next = BLOCK_CHAIN (block);
4467 BLOCK_CHAIN (block) = prev;
4468 if (BLOCK_FRAGMENT_CHAIN (block)
4469 && BLOCK_FRAGMENT_ORIGIN (block) == NULL_TREE)
4470 {
4471 BLOCK_FRAGMENT_CHAIN (block)
4472 = block_fragments_nreverse (BLOCK_FRAGMENT_CHAIN (block));
4473 if (!BLOCK_SAME_RANGE (BLOCK_FRAGMENT_CHAIN (block)))
4474 BLOCK_SAME_RANGE (block) = 0;
4475 }
4476 BLOCK_SUBBLOCKS (block) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block));
4477 prev = block;
4478 }
4479 return prev;
4480 }
4481
4482
4483 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
4484 and create duplicate blocks. */
4485 /* ??? Need an option to either create block fragments or to create
4486 abstract origin duplicates of a source block. It really depends
4487 on what optimization has been performed. */
4488
4489 void
4490 reorder_blocks (void)
4491 {
4492 tree block = DECL_INITIAL (current_function_decl);
4493
4494 if (block == NULL_TREE)
4495 return;
4496
4497 auto_vec<tree, 10> block_stack;
4498
4499 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
4500 clear_block_marks (block);
4501
4502 /* Prune the old trees away, so that they don't get in the way. */
4503 BLOCK_SUBBLOCKS (block) = NULL_TREE;
4504 BLOCK_CHAIN (block) = NULL_TREE;
4505
4506 /* Recreate the block tree from the note nesting. */
4507 reorder_blocks_1 (get_insns (), block, &block_stack);
4508 BLOCK_SUBBLOCKS (block) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block));
4509 }
4510
4511 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
4512
4513 void
4514 clear_block_marks (tree block)
4515 {
4516 while (block)
4517 {
4518 TREE_ASM_WRITTEN (block) = 0;
4519 clear_block_marks (BLOCK_SUBBLOCKS (block));
4520 block = BLOCK_CHAIN (block);
4521 }
4522 }
4523
4524 static void
4525 reorder_blocks_1 (rtx_insn *insns, tree current_block,
4526 vec<tree> *p_block_stack)
4527 {
4528 rtx_insn *insn;
4529 tree prev_beg = NULL_TREE, prev_end = NULL_TREE;
4530
4531 for (insn = insns; insn; insn = NEXT_INSN (insn))
4532 {
4533 if (NOTE_P (insn))
4534 {
4535 if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_BEG)
4536 {
4537 tree block = NOTE_BLOCK (insn);
4538 tree origin;
4539
4540 gcc_assert (BLOCK_FRAGMENT_ORIGIN (block) == NULL_TREE);
4541 origin = block;
4542
4543 if (prev_end)
4544 BLOCK_SAME_RANGE (prev_end) = 0;
4545 prev_end = NULL_TREE;
4546
4547 /* If we have seen this block before, that means it now
4548 spans multiple address regions. Create a new fragment. */
4549 if (TREE_ASM_WRITTEN (block))
4550 {
4551 tree new_block = copy_node (block);
4552
4553 BLOCK_SAME_RANGE (new_block) = 0;
4554 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
4555 BLOCK_FRAGMENT_CHAIN (new_block)
4556 = BLOCK_FRAGMENT_CHAIN (origin);
4557 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
4558
4559 NOTE_BLOCK (insn) = new_block;
4560 block = new_block;
4561 }
4562
4563 if (prev_beg == current_block && prev_beg)
4564 BLOCK_SAME_RANGE (block) = 1;
4565
4566 prev_beg = origin;
4567
4568 BLOCK_SUBBLOCKS (block) = 0;
4569 TREE_ASM_WRITTEN (block) = 1;
4570 /* When there's only one block for the entire function,
4571 current_block == block and we mustn't do this, it
4572 will cause infinite recursion. */
4573 if (block != current_block)
4574 {
4575 tree super;
4576 if (block != origin)
4577 gcc_assert (BLOCK_SUPERCONTEXT (origin) == current_block
4578 || BLOCK_FRAGMENT_ORIGIN (BLOCK_SUPERCONTEXT
4579 (origin))
4580 == current_block);
4581 if (p_block_stack->is_empty ())
4582 super = current_block;
4583 else
4584 {
4585 super = p_block_stack->last ();
4586 gcc_assert (super == current_block
4587 || BLOCK_FRAGMENT_ORIGIN (super)
4588 == current_block);
4589 }
4590 BLOCK_SUPERCONTEXT (block) = super;
4591 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
4592 BLOCK_SUBBLOCKS (current_block) = block;
4593 current_block = origin;
4594 }
4595 p_block_stack->safe_push (block);
4596 }
4597 else if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_END)
4598 {
4599 NOTE_BLOCK (insn) = p_block_stack->pop ();
4600 current_block = BLOCK_SUPERCONTEXT (current_block);
4601 if (BLOCK_FRAGMENT_ORIGIN (current_block))
4602 current_block = BLOCK_FRAGMENT_ORIGIN (current_block);
4603 prev_beg = NULL_TREE;
4604 prev_end = BLOCK_SAME_RANGE (NOTE_BLOCK (insn))
4605 ? NOTE_BLOCK (insn) : NULL_TREE;
4606 }
4607 }
4608 else
4609 {
4610 prev_beg = NULL_TREE;
4611 if (prev_end)
4612 BLOCK_SAME_RANGE (prev_end) = 0;
4613 prev_end = NULL_TREE;
4614 }
4615 }
4616 }
4617
4618 /* Reverse the order of elements in the chain T of blocks,
4619 and return the new head of the chain (old last element). */
4620
4621 tree
4622 blocks_nreverse (tree t)
4623 {
4624 tree prev = 0, block, next;
4625 for (block = t; block; block = next)
4626 {
4627 next = BLOCK_CHAIN (block);
4628 BLOCK_CHAIN (block) = prev;
4629 prev = block;
4630 }
4631 return prev;
4632 }
4633
4634 /* Concatenate two chains of blocks (chained through BLOCK_CHAIN)
4635 by modifying the last node in chain 1 to point to chain 2. */
4636
4637 tree
4638 block_chainon (tree op1, tree op2)
4639 {
4640 tree t1;
4641
4642 if (!op1)
4643 return op2;
4644 if (!op2)
4645 return op1;
4646
4647 for (t1 = op1; BLOCK_CHAIN (t1); t1 = BLOCK_CHAIN (t1))
4648 continue;
4649 BLOCK_CHAIN (t1) = op2;
4650
4651 #ifdef ENABLE_TREE_CHECKING
4652 {
4653 tree t2;
4654 for (t2 = op2; t2; t2 = BLOCK_CHAIN (t2))
4655 gcc_assert (t2 != t1);
4656 }
4657 #endif
4658
4659 return op1;
4660 }
4661
4662 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
4663 non-NULL, list them all into VECTOR, in a depth-first preorder
4664 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
4665 blocks. */
4666
4667 static int
4668 all_blocks (tree block, tree *vector)
4669 {
4670 int n_blocks = 0;
4671
4672 while (block)
4673 {
4674 TREE_ASM_WRITTEN (block) = 0;
4675
4676 /* Record this block. */
4677 if (vector)
4678 vector[n_blocks] = block;
4679
4680 ++n_blocks;
4681
4682 /* Record the subblocks, and their subblocks... */
4683 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
4684 vector ? vector + n_blocks : 0);
4685 block = BLOCK_CHAIN (block);
4686 }
4687
4688 return n_blocks;
4689 }
4690
4691 /* Return a vector containing all the blocks rooted at BLOCK. The
4692 number of elements in the vector is stored in N_BLOCKS_P. The
4693 vector is dynamically allocated; it is the caller's responsibility
4694 to call `free' on the pointer returned. */
4695
4696 static tree *
4697 get_block_vector (tree block, int *n_blocks_p)
4698 {
4699 tree *block_vector;
4700
4701 *n_blocks_p = all_blocks (block, NULL);
4702 block_vector = XNEWVEC (tree, *n_blocks_p);
4703 all_blocks (block, block_vector);
4704
4705 return block_vector;
4706 }
4707
4708 static GTY(()) int next_block_index = 2;
4709
4710 /* Set BLOCK_NUMBER for all the blocks in FN. */
4711
4712 void
4713 number_blocks (tree fn)
4714 {
4715 int i;
4716 int n_blocks;
4717 tree *block_vector;
4718
4719 /* For SDB and XCOFF debugging output, we start numbering the blocks
4720 from 1 within each function, rather than keeping a running
4721 count. */
4722 #if SDB_DEBUGGING_INFO || defined (XCOFF_DEBUGGING_INFO)
4723 if (write_symbols == SDB_DEBUG || write_symbols == XCOFF_DEBUG)
4724 next_block_index = 1;
4725 #endif
4726
4727 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
4728
4729 /* The top-level BLOCK isn't numbered at all. */
4730 for (i = 1; i < n_blocks; ++i)
4731 /* We number the blocks from two. */
4732 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
4733
4734 free (block_vector);
4735
4736 return;
4737 }
4738
4739 /* If VAR is present in a subblock of BLOCK, return the subblock. */
4740
4741 DEBUG_FUNCTION tree
4742 debug_find_var_in_block_tree (tree var, tree block)
4743 {
4744 tree t;
4745
4746 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
4747 if (t == var)
4748 return block;
4749
4750 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
4751 {
4752 tree ret = debug_find_var_in_block_tree (var, t);
4753 if (ret)
4754 return ret;
4755 }
4756
4757 return NULL_TREE;
4758 }
4759 \f
4760 /* Keep track of whether we're in a dummy function context. If we are,
4761 we don't want to invoke the set_current_function hook, because we'll
4762 get into trouble if the hook calls target_reinit () recursively or
4763 when the initial initialization is not yet complete. */
4764
4765 static bool in_dummy_function;
4766
4767 /* Invoke the target hook when setting cfun. Update the optimization options
4768 if the function uses different options than the default. */
4769
4770 static void
4771 invoke_set_current_function_hook (tree fndecl)
4772 {
4773 if (!in_dummy_function)
4774 {
4775 tree opts = ((fndecl)
4776 ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (fndecl)
4777 : optimization_default_node);
4778
4779 if (!opts)
4780 opts = optimization_default_node;
4781
4782 /* Change optimization options if needed. */
4783 if (optimization_current_node != opts)
4784 {
4785 optimization_current_node = opts;
4786 cl_optimization_restore (&global_options, TREE_OPTIMIZATION (opts));
4787 }
4788
4789 targetm.set_current_function (fndecl);
4790 this_fn_optabs = this_target_optabs;
4791
4792 if (opts != optimization_default_node)
4793 {
4794 init_tree_optimization_optabs (opts);
4795 if (TREE_OPTIMIZATION_OPTABS (opts))
4796 this_fn_optabs = (struct target_optabs *)
4797 TREE_OPTIMIZATION_OPTABS (opts);
4798 }
4799 }
4800 }
4801
4802 /* cfun should never be set directly; use this function. */
4803
4804 void
4805 set_cfun (struct function *new_cfun)
4806 {
4807 if (cfun != new_cfun)
4808 {
4809 cfun = new_cfun;
4810 invoke_set_current_function_hook (new_cfun ? new_cfun->decl : NULL_TREE);
4811 redirect_edge_var_map_empty ();
4812 }
4813 }
4814
4815 /* Initialized with NOGC, making this poisonous to the garbage collector. */
4816
4817 static vec<function *> cfun_stack;
4818
4819 /* Push the current cfun onto the stack, and set cfun to new_cfun. Also set
4820 current_function_decl accordingly. */
4821
4822 void
4823 push_cfun (struct function *new_cfun)
4824 {
4825 gcc_assert ((!cfun && !current_function_decl)
4826 || (cfun && current_function_decl == cfun->decl));
4827 cfun_stack.safe_push (cfun);
4828 current_function_decl = new_cfun ? new_cfun->decl : NULL_TREE;
4829 set_cfun (new_cfun);
4830 }
4831
4832 /* Pop cfun from the stack. Also set current_function_decl accordingly. */
4833
4834 void
4835 pop_cfun (void)
4836 {
4837 struct function *new_cfun = cfun_stack.pop ();
4838 /* When in_dummy_function, we do have a cfun but current_function_decl is
4839 NULL. We also allow pushing NULL cfun and subsequently changing
4840 current_function_decl to something else and have both restored by
4841 pop_cfun. */
4842 gcc_checking_assert (in_dummy_function
4843 || !cfun
4844 || current_function_decl == cfun->decl);
4845 set_cfun (new_cfun);
4846 current_function_decl = new_cfun ? new_cfun->decl : NULL_TREE;
4847 }
4848
4849 /* Return value of funcdef and increase it. */
4850 int
4851 get_next_funcdef_no (void)
4852 {
4853 return funcdef_no++;
4854 }
4855
4856 /* Return value of funcdef. */
4857 int
4858 get_last_funcdef_no (void)
4859 {
4860 return funcdef_no;
4861 }
4862
4863 /* Allocate a function structure for FNDECL and set its contents
4864 to the defaults. Set cfun to the newly-allocated object.
4865 Some of the helper functions invoked during initialization assume
4866 that cfun has already been set. Therefore, assign the new object
4867 directly into cfun and invoke the back end hook explicitly at the
4868 very end, rather than initializing a temporary and calling set_cfun
4869 on it.
4870
4871 ABSTRACT_P is true if this is a function that will never be seen by
4872 the middle-end. Such functions are front-end concepts (like C++
4873 function templates) that do not correspond directly to functions
4874 placed in object files. */
4875
4876 void
4877 allocate_struct_function (tree fndecl, bool abstract_p)
4878 {
4879 tree fntype = fndecl ? TREE_TYPE (fndecl) : NULL_TREE;
4880
4881 cfun = ggc_cleared_alloc<function> ();
4882
4883 init_eh_for_function ();
4884
4885 if (init_machine_status)
4886 cfun->machine = (*init_machine_status) ();
4887
4888 #ifdef OVERRIDE_ABI_FORMAT
4889 OVERRIDE_ABI_FORMAT (fndecl);
4890 #endif
4891
4892 if (fndecl != NULL_TREE)
4893 {
4894 DECL_STRUCT_FUNCTION (fndecl) = cfun;
4895 cfun->decl = fndecl;
4896 current_function_funcdef_no = get_next_funcdef_no ();
4897 }
4898
4899 invoke_set_current_function_hook (fndecl);
4900
4901 if (fndecl != NULL_TREE)
4902 {
4903 tree result = DECL_RESULT (fndecl);
4904
4905 if (!abstract_p)
4906 {
4907 /* Now that we have activated any function-specific attributes
4908 that might affect layout, particularly vector modes, relayout
4909 each of the parameters and the result. */
4910 relayout_decl (result);
4911 for (tree parm = DECL_ARGUMENTS (fndecl); parm;
4912 parm = DECL_CHAIN (parm))
4913 relayout_decl (parm);
4914
4915 /* Similarly relayout the function decl. */
4916 targetm.target_option.relayout_function (fndecl);
4917 }
4918
4919 if (!abstract_p && aggregate_value_p (result, fndecl))
4920 {
4921 #ifdef PCC_STATIC_STRUCT_RETURN
4922 cfun->returns_pcc_struct = 1;
4923 #endif
4924 cfun->returns_struct = 1;
4925 }
4926
4927 cfun->stdarg = stdarg_p (fntype);
4928
4929 /* Assume all registers in stdarg functions need to be saved. */
4930 cfun->va_list_gpr_size = VA_LIST_MAX_GPR_SIZE;
4931 cfun->va_list_fpr_size = VA_LIST_MAX_FPR_SIZE;
4932
4933 /* ??? This could be set on a per-function basis by the front-end
4934 but is this worth the hassle? */
4935 cfun->can_throw_non_call_exceptions = flag_non_call_exceptions;
4936 cfun->can_delete_dead_exceptions = flag_delete_dead_exceptions;
4937
4938 if (!profile_flag && !flag_instrument_function_entry_exit)
4939 DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl) = 1;
4940 }
4941 }
4942
4943 /* This is like allocate_struct_function, but pushes a new cfun for FNDECL
4944 instead of just setting it. */
4945
4946 void
4947 push_struct_function (tree fndecl)
4948 {
4949 /* When in_dummy_function we might be in the middle of a pop_cfun and
4950 current_function_decl and cfun may not match. */
4951 gcc_assert (in_dummy_function
4952 || (!cfun && !current_function_decl)
4953 || (cfun && current_function_decl == cfun->decl));
4954 cfun_stack.safe_push (cfun);
4955 current_function_decl = fndecl;
4956 allocate_struct_function (fndecl, false);
4957 }
4958
4959 /* Reset crtl and other non-struct-function variables to defaults as
4960 appropriate for emitting rtl at the start of a function. */
4961
4962 static void
4963 prepare_function_start (void)
4964 {
4965 gcc_assert (!get_last_insn ());
4966 init_temp_slots ();
4967 init_emit ();
4968 init_varasm_status ();
4969 init_expr ();
4970 default_rtl_profile ();
4971
4972 if (flag_stack_usage_info)
4973 {
4974 cfun->su = ggc_cleared_alloc<stack_usage> ();
4975 cfun->su->static_stack_size = -1;
4976 }
4977
4978 cse_not_expected = ! optimize;
4979
4980 /* Caller save not needed yet. */
4981 caller_save_needed = 0;
4982
4983 /* We haven't done register allocation yet. */
4984 reg_renumber = 0;
4985
4986 /* Indicate that we have not instantiated virtual registers yet. */
4987 virtuals_instantiated = 0;
4988
4989 /* Indicate that we want CONCATs now. */
4990 generating_concat_p = 1;
4991
4992 /* Indicate we have no need of a frame pointer yet. */
4993 frame_pointer_needed = 0;
4994 }
4995
4996 void
4997 push_dummy_function (bool with_decl)
4998 {
4999 tree fn_decl, fn_type, fn_result_decl;
5000
5001 gcc_assert (!in_dummy_function);
5002 in_dummy_function = true;
5003
5004 if (with_decl)
5005 {
5006 fn_type = build_function_type_list (void_type_node, NULL_TREE);
5007 fn_decl = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL, NULL_TREE,
5008 fn_type);
5009 fn_result_decl = build_decl (UNKNOWN_LOCATION, RESULT_DECL,
5010 NULL_TREE, void_type_node);
5011 DECL_RESULT (fn_decl) = fn_result_decl;
5012 }
5013 else
5014 fn_decl = NULL_TREE;
5015
5016 push_struct_function (fn_decl);
5017 }
5018
5019 /* Initialize the rtl expansion mechanism so that we can do simple things
5020 like generate sequences. This is used to provide a context during global
5021 initialization of some passes. You must call expand_dummy_function_end
5022 to exit this context. */
5023
5024 void
5025 init_dummy_function_start (void)
5026 {
5027 push_dummy_function (false);
5028 prepare_function_start ();
5029 }
5030
5031 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
5032 and initialize static variables for generating RTL for the statements
5033 of the function. */
5034
5035 void
5036 init_function_start (tree subr)
5037 {
5038 /* Initialize backend, if needed. */
5039 initialize_rtl ();
5040
5041 prepare_function_start ();
5042 decide_function_section (subr);
5043
5044 /* Warn if this value is an aggregate type,
5045 regardless of which calling convention we are using for it. */
5046 if (AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
5047 warning (OPT_Waggregate_return, "function returns an aggregate");
5048 }
5049
5050 /* Expand code to verify the stack_protect_guard. This is invoked at
5051 the end of a function to be protected. */
5052
5053 void
5054 stack_protect_epilogue (void)
5055 {
5056 tree guard_decl = targetm.stack_protect_guard ();
5057 rtx_code_label *label = gen_label_rtx ();
5058 rtx x, y;
5059 rtx_insn *seq;
5060
5061 x = expand_normal (crtl->stack_protect_guard);
5062 y = expand_normal (guard_decl);
5063
5064 /* Allow the target to compare Y with X without leaking either into
5065 a register. */
5066 if (targetm.have_stack_protect_test ()
5067 && ((seq = targetm.gen_stack_protect_test (x, y, label)) != NULL_RTX))
5068 emit_insn (seq);
5069 else
5070 emit_cmp_and_jump_insns (x, y, EQ, NULL_RTX, ptr_mode, 1, label);
5071
5072 /* The noreturn predictor has been moved to the tree level. The rtl-level
5073 predictors estimate this branch about 20%, which isn't enough to get
5074 things moved out of line. Since this is the only extant case of adding
5075 a noreturn function at the rtl level, it doesn't seem worth doing ought
5076 except adding the prediction by hand. */
5077 rtx_insn *tmp = get_last_insn ();
5078 if (JUMP_P (tmp))
5079 predict_insn_def (tmp, PRED_NORETURN, TAKEN);
5080
5081 expand_call (targetm.stack_protect_fail (), NULL_RTX, /*ignore=*/true);
5082 free_temp_slots ();
5083 emit_label (label);
5084 }
5085 \f
5086 /* Start the RTL for a new function, and set variables used for
5087 emitting RTL.
5088 SUBR is the FUNCTION_DECL node.
5089 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
5090 the function's parameters, which must be run at any return statement. */
5091
5092 void
5093 expand_function_start (tree subr)
5094 {
5095 /* Make sure volatile mem refs aren't considered
5096 valid operands of arithmetic insns. */
5097 init_recog_no_volatile ();
5098
5099 crtl->profile
5100 = (profile_flag
5101 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
5102
5103 crtl->limit_stack
5104 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
5105
5106 /* Make the label for return statements to jump to. Do not special
5107 case machines with special return instructions -- they will be
5108 handled later during jump, ifcvt, or epilogue creation. */
5109 return_label = gen_label_rtx ();
5110
5111 /* Initialize rtx used to return the value. */
5112 /* Do this before assign_parms so that we copy the struct value address
5113 before any library calls that assign parms might generate. */
5114
5115 /* Decide whether to return the value in memory or in a register. */
5116 tree res = DECL_RESULT (subr);
5117 if (aggregate_value_p (res, subr))
5118 {
5119 /* Returning something that won't go in a register. */
5120 rtx value_address = 0;
5121
5122 #ifdef PCC_STATIC_STRUCT_RETURN
5123 if (cfun->returns_pcc_struct)
5124 {
5125 int size = int_size_in_bytes (TREE_TYPE (res));
5126 value_address = assemble_static_space (size);
5127 }
5128 else
5129 #endif
5130 {
5131 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 2);
5132 /* Expect to be passed the address of a place to store the value.
5133 If it is passed as an argument, assign_parms will take care of
5134 it. */
5135 if (sv)
5136 {
5137 value_address = gen_reg_rtx (Pmode);
5138 emit_move_insn (value_address, sv);
5139 }
5140 }
5141 if (value_address)
5142 {
5143 rtx x = value_address;
5144 if (!DECL_BY_REFERENCE (res))
5145 {
5146 x = gen_rtx_MEM (DECL_MODE (res), x);
5147 set_mem_attributes (x, res, 1);
5148 }
5149 set_parm_rtl (res, x);
5150 }
5151 }
5152 else if (DECL_MODE (res) == VOIDmode)
5153 /* If return mode is void, this decl rtl should not be used. */
5154 set_parm_rtl (res, NULL_RTX);
5155 else
5156 {
5157 /* Compute the return values into a pseudo reg, which we will copy
5158 into the true return register after the cleanups are done. */
5159 tree return_type = TREE_TYPE (res);
5160
5161 /* If we may coalesce this result, make sure it has the expected mode
5162 in case it was promoted. But we need not bother about BLKmode. */
5163 machine_mode promoted_mode
5164 = flag_tree_coalesce_vars && is_gimple_reg (res)
5165 ? promote_ssa_mode (ssa_default_def (cfun, res), NULL)
5166 : BLKmode;
5167
5168 if (promoted_mode != BLKmode)
5169 set_parm_rtl (res, gen_reg_rtx (promoted_mode));
5170 else if (TYPE_MODE (return_type) != BLKmode
5171 && targetm.calls.return_in_msb (return_type))
5172 /* expand_function_end will insert the appropriate padding in
5173 this case. Use the return value's natural (unpadded) mode
5174 within the function proper. */
5175 set_parm_rtl (res, gen_reg_rtx (TYPE_MODE (return_type)));
5176 else
5177 {
5178 /* In order to figure out what mode to use for the pseudo, we
5179 figure out what the mode of the eventual return register will
5180 actually be, and use that. */
5181 rtx hard_reg = hard_function_value (return_type, subr, 0, 1);
5182
5183 /* Structures that are returned in registers are not
5184 aggregate_value_p, so we may see a PARALLEL or a REG. */
5185 if (REG_P (hard_reg))
5186 set_parm_rtl (res, gen_reg_rtx (GET_MODE (hard_reg)));
5187 else
5188 {
5189 gcc_assert (GET_CODE (hard_reg) == PARALLEL);
5190 set_parm_rtl (res, gen_group_rtx (hard_reg));
5191 }
5192 }
5193
5194 /* Set DECL_REGISTER flag so that expand_function_end will copy the
5195 result to the real return register(s). */
5196 DECL_REGISTER (res) = 1;
5197
5198 if (chkp_function_instrumented_p (current_function_decl))
5199 {
5200 tree return_type = TREE_TYPE (res);
5201 rtx bounds = targetm.calls.chkp_function_value_bounds (return_type,
5202 subr, 1);
5203 SET_DECL_BOUNDS_RTL (res, bounds);
5204 }
5205 }
5206
5207 /* Initialize rtx for parameters and local variables.
5208 In some cases this requires emitting insns. */
5209 assign_parms (subr);
5210
5211 /* If function gets a static chain arg, store it. */
5212 if (cfun->static_chain_decl)
5213 {
5214 tree parm = cfun->static_chain_decl;
5215 rtx local, chain;
5216 rtx_insn *insn;
5217 int unsignedp;
5218
5219 local = gen_reg_rtx (promote_decl_mode (parm, &unsignedp));
5220 chain = targetm.calls.static_chain (current_function_decl, true);
5221
5222 set_decl_incoming_rtl (parm, chain, false);
5223 set_parm_rtl (parm, local);
5224 mark_reg_pointer (local, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
5225
5226 if (GET_MODE (local) != GET_MODE (chain))
5227 {
5228 convert_move (local, chain, unsignedp);
5229 insn = get_last_insn ();
5230 }
5231 else
5232 insn = emit_move_insn (local, chain);
5233
5234 /* Mark the register as eliminable, similar to parameters. */
5235 if (MEM_P (chain)
5236 && reg_mentioned_p (arg_pointer_rtx, XEXP (chain, 0)))
5237 set_dst_reg_note (insn, REG_EQUIV, chain, local);
5238
5239 /* If we aren't optimizing, save the static chain onto the stack. */
5240 if (!optimize)
5241 {
5242 tree saved_static_chain_decl
5243 = build_decl (DECL_SOURCE_LOCATION (parm), VAR_DECL,
5244 DECL_NAME (parm), TREE_TYPE (parm));
5245 rtx saved_static_chain_rtx
5246 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
5247 SET_DECL_RTL (saved_static_chain_decl, saved_static_chain_rtx);
5248 emit_move_insn (saved_static_chain_rtx, chain);
5249 SET_DECL_VALUE_EXPR (parm, saved_static_chain_decl);
5250 DECL_HAS_VALUE_EXPR_P (parm) = 1;
5251 }
5252 }
5253
5254 /* If the function receives a non-local goto, then store the
5255 bits we need to restore the frame pointer. */
5256 if (cfun->nonlocal_goto_save_area)
5257 {
5258 tree t_save;
5259 rtx r_save;
5260
5261 tree var = TREE_OPERAND (cfun->nonlocal_goto_save_area, 0);
5262 gcc_assert (DECL_RTL_SET_P (var));
5263
5264 t_save = build4 (ARRAY_REF,
5265 TREE_TYPE (TREE_TYPE (cfun->nonlocal_goto_save_area)),
5266 cfun->nonlocal_goto_save_area,
5267 integer_zero_node, NULL_TREE, NULL_TREE);
5268 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
5269 gcc_assert (GET_MODE (r_save) == Pmode);
5270
5271 emit_move_insn (r_save, targetm.builtin_setjmp_frame_value ());
5272 update_nonlocal_goto_save_area ();
5273 }
5274
5275 /* The following was moved from init_function_start.
5276 The move is supposed to make sdb output more accurate. */
5277 /* Indicate the beginning of the function body,
5278 as opposed to parm setup. */
5279 emit_note (NOTE_INSN_FUNCTION_BEG);
5280
5281 gcc_assert (NOTE_P (get_last_insn ()));
5282
5283 parm_birth_insn = get_last_insn ();
5284
5285 if (crtl->profile)
5286 {
5287 #ifdef PROFILE_HOOK
5288 PROFILE_HOOK (current_function_funcdef_no);
5289 #endif
5290 }
5291
5292 /* If we are doing generic stack checking, the probe should go here. */
5293 if (flag_stack_check == GENERIC_STACK_CHECK)
5294 stack_check_probe_note = emit_note (NOTE_INSN_DELETED);
5295 }
5296 \f
5297 void
5298 pop_dummy_function (void)
5299 {
5300 pop_cfun ();
5301 in_dummy_function = false;
5302 }
5303
5304 /* Undo the effects of init_dummy_function_start. */
5305 void
5306 expand_dummy_function_end (void)
5307 {
5308 gcc_assert (in_dummy_function);
5309
5310 /* End any sequences that failed to be closed due to syntax errors. */
5311 while (in_sequence_p ())
5312 end_sequence ();
5313
5314 /* Outside function body, can't compute type's actual size
5315 until next function's body starts. */
5316
5317 free_after_parsing (cfun);
5318 free_after_compilation (cfun);
5319 pop_dummy_function ();
5320 }
5321
5322 /* Helper for diddle_return_value. */
5323
5324 void
5325 diddle_return_value_1 (void (*doit) (rtx, void *), void *arg, rtx outgoing)
5326 {
5327 if (! outgoing)
5328 return;
5329
5330 if (REG_P (outgoing))
5331 (*doit) (outgoing, arg);
5332 else if (GET_CODE (outgoing) == PARALLEL)
5333 {
5334 int i;
5335
5336 for (i = 0; i < XVECLEN (outgoing, 0); i++)
5337 {
5338 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
5339
5340 if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
5341 (*doit) (x, arg);
5342 }
5343 }
5344 }
5345
5346 /* Call DOIT for each hard register used as a return value from
5347 the current function. */
5348
5349 void
5350 diddle_return_value (void (*doit) (rtx, void *), void *arg)
5351 {
5352 diddle_return_value_1 (doit, arg, crtl->return_bnd);
5353 diddle_return_value_1 (doit, arg, crtl->return_rtx);
5354 }
5355
5356 static void
5357 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
5358 {
5359 emit_clobber (reg);
5360 }
5361
5362 void
5363 clobber_return_register (void)
5364 {
5365 diddle_return_value (do_clobber_return_reg, NULL);
5366
5367 /* In case we do use pseudo to return value, clobber it too. */
5368 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
5369 {
5370 tree decl_result = DECL_RESULT (current_function_decl);
5371 rtx decl_rtl = DECL_RTL (decl_result);
5372 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
5373 {
5374 do_clobber_return_reg (decl_rtl, NULL);
5375 }
5376 }
5377 }
5378
5379 static void
5380 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
5381 {
5382 emit_use (reg);
5383 }
5384
5385 static void
5386 use_return_register (void)
5387 {
5388 diddle_return_value (do_use_return_reg, NULL);
5389 }
5390
5391 /* Set the location of the insn chain starting at INSN to LOC. */
5392
5393 static void
5394 set_insn_locations (rtx_insn *insn, int loc)
5395 {
5396 while (insn != NULL)
5397 {
5398 if (INSN_P (insn))
5399 INSN_LOCATION (insn) = loc;
5400 insn = NEXT_INSN (insn);
5401 }
5402 }
5403
5404 /* Generate RTL for the end of the current function. */
5405
5406 void
5407 expand_function_end (void)
5408 {
5409 /* If arg_pointer_save_area was referenced only from a nested
5410 function, we will not have initialized it yet. Do that now. */
5411 if (arg_pointer_save_area && ! crtl->arg_pointer_save_area_init)
5412 get_arg_pointer_save_area ();
5413
5414 /* If we are doing generic stack checking and this function makes calls,
5415 do a stack probe at the start of the function to ensure we have enough
5416 space for another stack frame. */
5417 if (flag_stack_check == GENERIC_STACK_CHECK)
5418 {
5419 rtx_insn *insn, *seq;
5420
5421 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
5422 if (CALL_P (insn))
5423 {
5424 rtx max_frame_size = GEN_INT (STACK_CHECK_MAX_FRAME_SIZE);
5425 start_sequence ();
5426 if (STACK_CHECK_MOVING_SP)
5427 anti_adjust_stack_and_probe (max_frame_size, true);
5428 else
5429 probe_stack_range (STACK_OLD_CHECK_PROTECT, max_frame_size);
5430 seq = get_insns ();
5431 end_sequence ();
5432 set_insn_locations (seq, prologue_location);
5433 emit_insn_before (seq, stack_check_probe_note);
5434 break;
5435 }
5436 }
5437
5438 /* End any sequences that failed to be closed due to syntax errors. */
5439 while (in_sequence_p ())
5440 end_sequence ();
5441
5442 clear_pending_stack_adjust ();
5443 do_pending_stack_adjust ();
5444
5445 /* Output a linenumber for the end of the function.
5446 SDB depends on this. */
5447 set_curr_insn_location (input_location);
5448
5449 /* Before the return label (if any), clobber the return
5450 registers so that they are not propagated live to the rest of
5451 the function. This can only happen with functions that drop
5452 through; if there had been a return statement, there would
5453 have either been a return rtx, or a jump to the return label.
5454
5455 We delay actual code generation after the current_function_value_rtx
5456 is computed. */
5457 rtx_insn *clobber_after = get_last_insn ();
5458
5459 /* Output the label for the actual return from the function. */
5460 emit_label (return_label);
5461
5462 if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ)
5463 {
5464 /* Let except.c know where it should emit the call to unregister
5465 the function context for sjlj exceptions. */
5466 if (flag_exceptions)
5467 sjlj_emit_function_exit_after (get_last_insn ());
5468 }
5469 else
5470 {
5471 /* We want to ensure that instructions that may trap are not
5472 moved into the epilogue by scheduling, because we don't
5473 always emit unwind information for the epilogue. */
5474 if (cfun->can_throw_non_call_exceptions)
5475 emit_insn (gen_blockage ());
5476 }
5477
5478 /* If this is an implementation of throw, do what's necessary to
5479 communicate between __builtin_eh_return and the epilogue. */
5480 expand_eh_return ();
5481
5482 /* If scalar return value was computed in a pseudo-reg, or was a named
5483 return value that got dumped to the stack, copy that to the hard
5484 return register. */
5485 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
5486 {
5487 tree decl_result = DECL_RESULT (current_function_decl);
5488 rtx decl_rtl = DECL_RTL (decl_result);
5489
5490 if (REG_P (decl_rtl)
5491 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
5492 : DECL_REGISTER (decl_result))
5493 {
5494 rtx real_decl_rtl = crtl->return_rtx;
5495
5496 /* This should be set in assign_parms. */
5497 gcc_assert (REG_FUNCTION_VALUE_P (real_decl_rtl));
5498
5499 /* If this is a BLKmode structure being returned in registers,
5500 then use the mode computed in expand_return. Note that if
5501 decl_rtl is memory, then its mode may have been changed,
5502 but that crtl->return_rtx has not. */
5503 if (GET_MODE (real_decl_rtl) == BLKmode)
5504 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
5505
5506 /* If a non-BLKmode return value should be padded at the least
5507 significant end of the register, shift it left by the appropriate
5508 amount. BLKmode results are handled using the group load/store
5509 machinery. */
5510 if (TYPE_MODE (TREE_TYPE (decl_result)) != BLKmode
5511 && REG_P (real_decl_rtl)
5512 && targetm.calls.return_in_msb (TREE_TYPE (decl_result)))
5513 {
5514 emit_move_insn (gen_rtx_REG (GET_MODE (decl_rtl),
5515 REGNO (real_decl_rtl)),
5516 decl_rtl);
5517 shift_return_value (GET_MODE (decl_rtl), true, real_decl_rtl);
5518 }
5519 else if (GET_CODE (real_decl_rtl) == PARALLEL)
5520 {
5521 /* If expand_function_start has created a PARALLEL for decl_rtl,
5522 move the result to the real return registers. Otherwise, do
5523 a group load from decl_rtl for a named return. */
5524 if (GET_CODE (decl_rtl) == PARALLEL)
5525 emit_group_move (real_decl_rtl, decl_rtl);
5526 else
5527 emit_group_load (real_decl_rtl, decl_rtl,
5528 TREE_TYPE (decl_result),
5529 int_size_in_bytes (TREE_TYPE (decl_result)));
5530 }
5531 /* In the case of complex integer modes smaller than a word, we'll
5532 need to generate some non-trivial bitfield insertions. Do that
5533 on a pseudo and not the hard register. */
5534 else if (GET_CODE (decl_rtl) == CONCAT
5535 && GET_MODE_CLASS (GET_MODE (decl_rtl)) == MODE_COMPLEX_INT
5536 && GET_MODE_BITSIZE (GET_MODE (decl_rtl)) <= BITS_PER_WORD)
5537 {
5538 int old_generating_concat_p;
5539 rtx tmp;
5540
5541 old_generating_concat_p = generating_concat_p;
5542 generating_concat_p = 0;
5543 tmp = gen_reg_rtx (GET_MODE (decl_rtl));
5544 generating_concat_p = old_generating_concat_p;
5545
5546 emit_move_insn (tmp, decl_rtl);
5547 emit_move_insn (real_decl_rtl, tmp);
5548 }
5549 /* If a named return value dumped decl_return to memory, then
5550 we may need to re-do the PROMOTE_MODE signed/unsigned
5551 extension. */
5552 else if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
5553 {
5554 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
5555 promote_function_mode (TREE_TYPE (decl_result),
5556 GET_MODE (decl_rtl), &unsignedp,
5557 TREE_TYPE (current_function_decl), 1);
5558
5559 convert_move (real_decl_rtl, decl_rtl, unsignedp);
5560 }
5561 else
5562 emit_move_insn (real_decl_rtl, decl_rtl);
5563 }
5564 }
5565
5566 /* If returning a structure, arrange to return the address of the value
5567 in a place where debuggers expect to find it.
5568
5569 If returning a structure PCC style,
5570 the caller also depends on this value.
5571 And cfun->returns_pcc_struct is not necessarily set. */
5572 if ((cfun->returns_struct || cfun->returns_pcc_struct)
5573 && !targetm.calls.omit_struct_return_reg)
5574 {
5575 rtx value_address = DECL_RTL (DECL_RESULT (current_function_decl));
5576 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
5577 rtx outgoing;
5578
5579 if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
5580 type = TREE_TYPE (type);
5581 else
5582 value_address = XEXP (value_address, 0);
5583
5584 outgoing = targetm.calls.function_value (build_pointer_type (type),
5585 current_function_decl, true);
5586
5587 /* Mark this as a function return value so integrate will delete the
5588 assignment and USE below when inlining this function. */
5589 REG_FUNCTION_VALUE_P (outgoing) = 1;
5590
5591 /* The address may be ptr_mode and OUTGOING may be Pmode. */
5592 value_address = convert_memory_address (GET_MODE (outgoing),
5593 value_address);
5594
5595 emit_move_insn (outgoing, value_address);
5596
5597 /* Show return register used to hold result (in this case the address
5598 of the result. */
5599 crtl->return_rtx = outgoing;
5600 }
5601
5602 /* Emit the actual code to clobber return register. Don't emit
5603 it if clobber_after is a barrier, then the previous basic block
5604 certainly doesn't fall thru into the exit block. */
5605 if (!BARRIER_P (clobber_after))
5606 {
5607 start_sequence ();
5608 clobber_return_register ();
5609 rtx_insn *seq = get_insns ();
5610 end_sequence ();
5611
5612 emit_insn_after (seq, clobber_after);
5613 }
5614
5615 /* Output the label for the naked return from the function. */
5616 if (naked_return_label)
5617 emit_label (naked_return_label);
5618
5619 /* @@@ This is a kludge. We want to ensure that instructions that
5620 may trap are not moved into the epilogue by scheduling, because
5621 we don't always emit unwind information for the epilogue. */
5622 if (cfun->can_throw_non_call_exceptions
5623 && targetm_common.except_unwind_info (&global_options) != UI_SJLJ)
5624 emit_insn (gen_blockage ());
5625
5626 /* If stack protection is enabled for this function, check the guard. */
5627 if (crtl->stack_protect_guard)
5628 stack_protect_epilogue ();
5629
5630 /* If we had calls to alloca, and this machine needs
5631 an accurate stack pointer to exit the function,
5632 insert some code to save and restore the stack pointer. */
5633 if (! EXIT_IGNORE_STACK
5634 && cfun->calls_alloca)
5635 {
5636 rtx tem = 0;
5637
5638 start_sequence ();
5639 emit_stack_save (SAVE_FUNCTION, &tem);
5640 rtx_insn *seq = get_insns ();
5641 end_sequence ();
5642 emit_insn_before (seq, parm_birth_insn);
5643
5644 emit_stack_restore (SAVE_FUNCTION, tem);
5645 }
5646
5647 /* ??? This should no longer be necessary since stupid is no longer with
5648 us, but there are some parts of the compiler (eg reload_combine, and
5649 sh mach_dep_reorg) that still try and compute their own lifetime info
5650 instead of using the general framework. */
5651 use_return_register ();
5652 }
5653
5654 rtx
5655 get_arg_pointer_save_area (void)
5656 {
5657 rtx ret = arg_pointer_save_area;
5658
5659 if (! ret)
5660 {
5661 ret = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
5662 arg_pointer_save_area = ret;
5663 }
5664
5665 if (! crtl->arg_pointer_save_area_init)
5666 {
5667 /* Save the arg pointer at the beginning of the function. The
5668 generated stack slot may not be a valid memory address, so we
5669 have to check it and fix it if necessary. */
5670 start_sequence ();
5671 emit_move_insn (validize_mem (copy_rtx (ret)),
5672 crtl->args.internal_arg_pointer);
5673 rtx_insn *seq = get_insns ();
5674 end_sequence ();
5675
5676 push_topmost_sequence ();
5677 emit_insn_after (seq, entry_of_function ());
5678 pop_topmost_sequence ();
5679
5680 crtl->arg_pointer_save_area_init = true;
5681 }
5682
5683 return ret;
5684 }
5685 \f
5686 /* Add a list of INSNS to the hash HASHP, possibly allocating HASHP
5687 for the first time. */
5688
5689 static void
5690 record_insns (rtx_insn *insns, rtx end, hash_table<insn_cache_hasher> **hashp)
5691 {
5692 rtx_insn *tmp;
5693 hash_table<insn_cache_hasher> *hash = *hashp;
5694
5695 if (hash == NULL)
5696 *hashp = hash = hash_table<insn_cache_hasher>::create_ggc (17);
5697
5698 for (tmp = insns; tmp != end; tmp = NEXT_INSN (tmp))
5699 {
5700 rtx *slot = hash->find_slot (tmp, INSERT);
5701 gcc_assert (*slot == NULL);
5702 *slot = tmp;
5703 }
5704 }
5705
5706 /* INSN has been duplicated or replaced by as COPY, perhaps by duplicating a
5707 basic block, splitting or peepholes. If INSN is a prologue or epilogue
5708 insn, then record COPY as well. */
5709
5710 void
5711 maybe_copy_prologue_epilogue_insn (rtx insn, rtx copy)
5712 {
5713 hash_table<insn_cache_hasher> *hash;
5714 rtx *slot;
5715
5716 hash = epilogue_insn_hash;
5717 if (!hash || !hash->find (insn))
5718 {
5719 hash = prologue_insn_hash;
5720 if (!hash || !hash->find (insn))
5721 return;
5722 }
5723
5724 slot = hash->find_slot (copy, INSERT);
5725 gcc_assert (*slot == NULL);
5726 *slot = copy;
5727 }
5728
5729 /* Determine if any INSNs in HASH are, or are part of, INSN. Because
5730 we can be running after reorg, SEQUENCE rtl is possible. */
5731
5732 static bool
5733 contains (const_rtx insn, hash_table<insn_cache_hasher> *hash)
5734 {
5735 if (hash == NULL)
5736 return false;
5737
5738 if (NONJUMP_INSN_P (insn) && GET_CODE (PATTERN (insn)) == SEQUENCE)
5739 {
5740 rtx_sequence *seq = as_a <rtx_sequence *> (PATTERN (insn));
5741 int i;
5742 for (i = seq->len () - 1; i >= 0; i--)
5743 if (hash->find (seq->element (i)))
5744 return true;
5745 return false;
5746 }
5747
5748 return hash->find (const_cast<rtx> (insn)) != NULL;
5749 }
5750
5751 int
5752 prologue_epilogue_contains (const_rtx insn)
5753 {
5754 if (contains (insn, prologue_insn_hash))
5755 return 1;
5756 if (contains (insn, epilogue_insn_hash))
5757 return 1;
5758 return 0;
5759 }
5760
5761
5762 /* Set JUMP_LABEL for a return insn. */
5763
5764 void
5765 set_return_jump_label (rtx_insn *returnjump)
5766 {
5767 rtx pat = PATTERN (returnjump);
5768 if (GET_CODE (pat) == PARALLEL)
5769 pat = XVECEXP (pat, 0, 0);
5770 if (ANY_RETURN_P (pat))
5771 JUMP_LABEL (returnjump) = pat;
5772 else
5773 JUMP_LABEL (returnjump) = ret_rtx;
5774 }
5775
5776 /* Return a sequence to be used as the split prologue for the current
5777 function, or NULL. */
5778
5779 static rtx_insn *
5780 make_split_prologue_seq (void)
5781 {
5782 if (!flag_split_stack
5783 || lookup_attribute ("no_split_stack", DECL_ATTRIBUTES (cfun->decl)))
5784 return NULL;
5785
5786 start_sequence ();
5787 emit_insn (targetm.gen_split_stack_prologue ());
5788 rtx_insn *seq = get_insns ();
5789 end_sequence ();
5790
5791 record_insns (seq, NULL, &prologue_insn_hash);
5792 set_insn_locations (seq, prologue_location);
5793
5794 return seq;
5795 }
5796
5797 /* Return a sequence to be used as the prologue for the current function,
5798 or NULL. */
5799
5800 static rtx_insn *
5801 make_prologue_seq (void)
5802 {
5803 if (!targetm.have_prologue ())
5804 return NULL;
5805
5806 start_sequence ();
5807 rtx_insn *seq = targetm.gen_prologue ();
5808 emit_insn (seq);
5809
5810 /* Insert an explicit USE for the frame pointer
5811 if the profiling is on and the frame pointer is required. */
5812 if (crtl->profile && frame_pointer_needed)
5813 emit_use (hard_frame_pointer_rtx);
5814
5815 /* Retain a map of the prologue insns. */
5816 record_insns (seq, NULL, &prologue_insn_hash);
5817 emit_note (NOTE_INSN_PROLOGUE_END);
5818
5819 /* Ensure that instructions are not moved into the prologue when
5820 profiling is on. The call to the profiling routine can be
5821 emitted within the live range of a call-clobbered register. */
5822 if (!targetm.profile_before_prologue () && crtl->profile)
5823 emit_insn (gen_blockage ());
5824
5825 seq = get_insns ();
5826 end_sequence ();
5827 set_insn_locations (seq, prologue_location);
5828
5829 return seq;
5830 }
5831
5832 /* Return a sequence to be used as the epilogue for the current function,
5833 or NULL. */
5834
5835 static rtx_insn *
5836 make_epilogue_seq (void)
5837 {
5838 if (!targetm.have_epilogue ())
5839 return NULL;
5840
5841 start_sequence ();
5842 emit_note (NOTE_INSN_EPILOGUE_BEG);
5843 rtx_insn *seq = targetm.gen_epilogue ();
5844 if (seq)
5845 emit_jump_insn (seq);
5846
5847 /* Retain a map of the epilogue insns. */
5848 record_insns (seq, NULL, &epilogue_insn_hash);
5849 set_insn_locations (seq, epilogue_location);
5850
5851 seq = get_insns ();
5852 rtx_insn *returnjump = get_last_insn ();
5853 end_sequence ();
5854
5855 if (JUMP_P (returnjump))
5856 set_return_jump_label (returnjump);
5857
5858 return seq;
5859 }
5860
5861
5862 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
5863 this into place with notes indicating where the prologue ends and where
5864 the epilogue begins. Update the basic block information when possible.
5865
5866 Notes on epilogue placement:
5867 There are several kinds of edges to the exit block:
5868 * a single fallthru edge from LAST_BB
5869 * possibly, edges from blocks containing sibcalls
5870 * possibly, fake edges from infinite loops
5871
5872 The epilogue is always emitted on the fallthru edge from the last basic
5873 block in the function, LAST_BB, into the exit block.
5874
5875 If LAST_BB is empty except for a label, it is the target of every
5876 other basic block in the function that ends in a return. If a
5877 target has a return or simple_return pattern (possibly with
5878 conditional variants), these basic blocks can be changed so that a
5879 return insn is emitted into them, and their target is adjusted to
5880 the real exit block.
5881
5882 Notes on shrink wrapping: We implement a fairly conservative
5883 version of shrink-wrapping rather than the textbook one. We only
5884 generate a single prologue and a single epilogue. This is
5885 sufficient to catch a number of interesting cases involving early
5886 exits.
5887
5888 First, we identify the blocks that require the prologue to occur before
5889 them. These are the ones that modify a call-saved register, or reference
5890 any of the stack or frame pointer registers. To simplify things, we then
5891 mark everything reachable from these blocks as also requiring a prologue.
5892 This takes care of loops automatically, and avoids the need to examine
5893 whether MEMs reference the frame, since it is sufficient to check for
5894 occurrences of the stack or frame pointer.
5895
5896 We then compute the set of blocks for which the need for a prologue
5897 is anticipatable (borrowing terminology from the shrink-wrapping
5898 description in Muchnick's book). These are the blocks which either
5899 require a prologue themselves, or those that have only successors
5900 where the prologue is anticipatable. The prologue needs to be
5901 inserted on all edges from BB1->BB2 where BB2 is in ANTIC and BB1
5902 is not. For the moment, we ensure that only one such edge exists.
5903
5904 The epilogue is placed as described above, but we make a
5905 distinction between inserting return and simple_return patterns
5906 when modifying other blocks that end in a return. Blocks that end
5907 in a sibcall omit the sibcall_epilogue if the block is not in
5908 ANTIC. */
5909
5910 void
5911 thread_prologue_and_epilogue_insns (void)
5912 {
5913 df_analyze ();
5914
5915 /* Can't deal with multiple successors of the entry block at the
5916 moment. Function should always have at least one entry
5917 point. */
5918 gcc_assert (single_succ_p (ENTRY_BLOCK_PTR_FOR_FN (cfun)));
5919
5920 edge entry_edge = single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun));
5921 edge orig_entry_edge = entry_edge;
5922
5923 rtx_insn *split_prologue_seq = make_split_prologue_seq ();
5924 rtx_insn *prologue_seq = make_prologue_seq ();
5925 rtx_insn *epilogue_seq = make_epilogue_seq ();
5926
5927 /* Try to perform a kind of shrink-wrapping, making sure the
5928 prologue/epilogue is emitted only around those parts of the
5929 function that require it. */
5930
5931 try_shrink_wrapping (&entry_edge, prologue_seq);
5932
5933
5934 rtl_profile_for_bb (EXIT_BLOCK_PTR_FOR_FN (cfun));
5935
5936 /* A small fib -- epilogue is not yet completed, but we wish to re-use
5937 this marker for the splits of EH_RETURN patterns, and nothing else
5938 uses the flag in the meantime. */
5939 epilogue_completed = 1;
5940
5941 /* Find non-fallthru edges that end with EH_RETURN instructions. On
5942 some targets, these get split to a special version of the epilogue
5943 code. In order to be able to properly annotate these with unwind
5944 info, try to split them now. If we get a valid split, drop an
5945 EPILOGUE_BEG note and mark the insns as epilogue insns. */
5946 edge e;
5947 edge_iterator ei;
5948 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
5949 {
5950 rtx_insn *prev, *last, *trial;
5951
5952 if (e->flags & EDGE_FALLTHRU)
5953 continue;
5954 last = BB_END (e->src);
5955 if (!eh_returnjump_p (last))
5956 continue;
5957
5958 prev = PREV_INSN (last);
5959 trial = try_split (PATTERN (last), last, 1);
5960 if (trial == last)
5961 continue;
5962
5963 record_insns (NEXT_INSN (prev), NEXT_INSN (trial), &epilogue_insn_hash);
5964 emit_note_after (NOTE_INSN_EPILOGUE_BEG, prev);
5965 }
5966
5967 edge exit_fallthru_edge = find_fallthru_edge (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds);
5968
5969 if (exit_fallthru_edge)
5970 {
5971 if (epilogue_seq)
5972 {
5973 insert_insn_on_edge (epilogue_seq, exit_fallthru_edge);
5974 commit_edge_insertions ();
5975
5976 /* The epilogue insns we inserted may cause the exit edge to no longer
5977 be fallthru. */
5978 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
5979 {
5980 if (((e->flags & EDGE_FALLTHRU) != 0)
5981 && returnjump_p (BB_END (e->src)))
5982 e->flags &= ~EDGE_FALLTHRU;
5983 }
5984 }
5985 else if (next_active_insn (BB_END (exit_fallthru_edge->src)))
5986 {
5987 /* We have a fall-through edge to the exit block, the source is not
5988 at the end of the function, and there will be an assembler epilogue
5989 at the end of the function.
5990 We can't use force_nonfallthru here, because that would try to
5991 use return. Inserting a jump 'by hand' is extremely messy, so
5992 we take advantage of cfg_layout_finalize using
5993 fixup_fallthru_exit_predecessor. */
5994 cfg_layout_initialize (0);
5995 basic_block cur_bb;
5996 FOR_EACH_BB_FN (cur_bb, cfun)
5997 if (cur_bb->index >= NUM_FIXED_BLOCKS
5998 && cur_bb->next_bb->index >= NUM_FIXED_BLOCKS)
5999 cur_bb->aux = cur_bb->next_bb;
6000 cfg_layout_finalize ();
6001 }
6002 }
6003
6004 /* Insert the prologue. */
6005
6006 rtl_profile_for_bb (ENTRY_BLOCK_PTR_FOR_FN (cfun));
6007
6008 if (split_prologue_seq || prologue_seq)
6009 {
6010 if (split_prologue_seq)
6011 insert_insn_on_edge (split_prologue_seq, orig_entry_edge);
6012
6013 if (prologue_seq)
6014 insert_insn_on_edge (prologue_seq, entry_edge);
6015
6016 commit_edge_insertions ();
6017
6018 /* Look for basic blocks within the prologue insns. */
6019 auto_sbitmap blocks (last_basic_block_for_fn (cfun));
6020 bitmap_clear (blocks);
6021 bitmap_set_bit (blocks, entry_edge->dest->index);
6022 bitmap_set_bit (blocks, orig_entry_edge->dest->index);
6023 find_many_sub_basic_blocks (blocks);
6024 }
6025
6026 default_rtl_profile ();
6027
6028 /* Emit sibling epilogues before any sibling call sites. */
6029 for (ei = ei_start (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds);
6030 (e = ei_safe_edge (ei));
6031 ei_next (&ei))
6032 {
6033 /* Skip those already handled, the ones that run without prologue. */
6034 if (e->flags & EDGE_IGNORE)
6035 {
6036 e->flags &= ~EDGE_IGNORE;
6037 continue;
6038 }
6039
6040 rtx_insn *insn = BB_END (e->src);
6041
6042 if (!(CALL_P (insn) && SIBLING_CALL_P (insn)))
6043 continue;
6044
6045 if (rtx_insn *ep_seq = targetm.gen_sibcall_epilogue ())
6046 {
6047 start_sequence ();
6048 emit_note (NOTE_INSN_EPILOGUE_BEG);
6049 emit_insn (ep_seq);
6050 rtx_insn *seq = get_insns ();
6051 end_sequence ();
6052
6053 /* Retain a map of the epilogue insns. Used in life analysis to
6054 avoid getting rid of sibcall epilogue insns. Do this before we
6055 actually emit the sequence. */
6056 record_insns (seq, NULL, &epilogue_insn_hash);
6057 set_insn_locations (seq, epilogue_location);
6058
6059 emit_insn_before (seq, insn);
6060 }
6061 }
6062
6063 if (epilogue_seq)
6064 {
6065 rtx_insn *insn, *next;
6066
6067 /* Similarly, move any line notes that appear after the epilogue.
6068 There is no need, however, to be quite so anal about the existence
6069 of such a note. Also possibly move
6070 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
6071 info generation. */
6072 for (insn = epilogue_seq; insn; insn = next)
6073 {
6074 next = NEXT_INSN (insn);
6075 if (NOTE_P (insn)
6076 && (NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG))
6077 reorder_insns (insn, insn, PREV_INSN (epilogue_seq));
6078 }
6079 }
6080
6081 /* Threading the prologue and epilogue changes the artificial refs
6082 in the entry and exit blocks. */
6083 epilogue_completed = 1;
6084 df_update_entry_exit_and_calls ();
6085 }
6086
6087 /* Reposition the prologue-end and epilogue-begin notes after
6088 instruction scheduling. */
6089
6090 void
6091 reposition_prologue_and_epilogue_notes (void)
6092 {
6093 if (!targetm.have_prologue ()
6094 && !targetm.have_epilogue ()
6095 && !targetm.have_sibcall_epilogue ())
6096 return;
6097
6098 /* Since the hash table is created on demand, the fact that it is
6099 non-null is a signal that it is non-empty. */
6100 if (prologue_insn_hash != NULL)
6101 {
6102 size_t len = prologue_insn_hash->elements ();
6103 rtx_insn *insn, *last = NULL, *note = NULL;
6104
6105 /* Scan from the beginning until we reach the last prologue insn. */
6106 /* ??? While we do have the CFG intact, there are two problems:
6107 (1) The prologue can contain loops (typically probing the stack),
6108 which means that the end of the prologue isn't in the first bb.
6109 (2) Sometimes the PROLOGUE_END note gets pushed into the next bb. */
6110 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
6111 {
6112 if (NOTE_P (insn))
6113 {
6114 if (NOTE_KIND (insn) == NOTE_INSN_PROLOGUE_END)
6115 note = insn;
6116 }
6117 else if (contains (insn, prologue_insn_hash))
6118 {
6119 last = insn;
6120 if (--len == 0)
6121 break;
6122 }
6123 }
6124
6125 if (last)
6126 {
6127 if (note == NULL)
6128 {
6129 /* Scan forward looking for the PROLOGUE_END note. It should
6130 be right at the beginning of the block, possibly with other
6131 insn notes that got moved there. */
6132 for (note = NEXT_INSN (last); ; note = NEXT_INSN (note))
6133 {
6134 if (NOTE_P (note)
6135 && NOTE_KIND (note) == NOTE_INSN_PROLOGUE_END)
6136 break;
6137 }
6138 }
6139
6140 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
6141 if (LABEL_P (last))
6142 last = NEXT_INSN (last);
6143 reorder_insns (note, note, last);
6144 }
6145 }
6146
6147 if (epilogue_insn_hash != NULL)
6148 {
6149 edge_iterator ei;
6150 edge e;
6151
6152 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
6153 {
6154 rtx_insn *insn, *first = NULL, *note = NULL;
6155 basic_block bb = e->src;
6156
6157 /* Scan from the beginning until we reach the first epilogue insn. */
6158 FOR_BB_INSNS (bb, insn)
6159 {
6160 if (NOTE_P (insn))
6161 {
6162 if (NOTE_KIND (insn) == NOTE_INSN_EPILOGUE_BEG)
6163 {
6164 note = insn;
6165 if (first != NULL)
6166 break;
6167 }
6168 }
6169 else if (first == NULL && contains (insn, epilogue_insn_hash))
6170 {
6171 first = insn;
6172 if (note != NULL)
6173 break;
6174 }
6175 }
6176
6177 if (note)
6178 {
6179 /* If the function has a single basic block, and no real
6180 epilogue insns (e.g. sibcall with no cleanup), the
6181 epilogue note can get scheduled before the prologue
6182 note. If we have frame related prologue insns, having
6183 them scanned during the epilogue will result in a crash.
6184 In this case re-order the epilogue note to just before
6185 the last insn in the block. */
6186 if (first == NULL)
6187 first = BB_END (bb);
6188
6189 if (PREV_INSN (first) != note)
6190 reorder_insns (note, note, PREV_INSN (first));
6191 }
6192 }
6193 }
6194 }
6195
6196 /* Returns the name of function declared by FNDECL. */
6197 const char *
6198 fndecl_name (tree fndecl)
6199 {
6200 if (fndecl == NULL)
6201 return "(nofn)";
6202 return lang_hooks.decl_printable_name (fndecl, 2);
6203 }
6204
6205 /* Returns the name of function FN. */
6206 const char *
6207 function_name (struct function *fn)
6208 {
6209 tree fndecl = (fn == NULL) ? NULL : fn->decl;
6210 return fndecl_name (fndecl);
6211 }
6212
6213 /* Returns the name of the current function. */
6214 const char *
6215 current_function_name (void)
6216 {
6217 return function_name (cfun);
6218 }
6219 \f
6220
6221 static unsigned int
6222 rest_of_handle_check_leaf_regs (void)
6223 {
6224 #ifdef LEAF_REGISTERS
6225 crtl->uses_only_leaf_regs
6226 = optimize > 0 && only_leaf_regs_used () && leaf_function_p ();
6227 #endif
6228 return 0;
6229 }
6230
6231 /* Insert a TYPE into the used types hash table of CFUN. */
6232
6233 static void
6234 used_types_insert_helper (tree type, struct function *func)
6235 {
6236 if (type != NULL && func != NULL)
6237 {
6238 if (func->used_types_hash == NULL)
6239 func->used_types_hash = hash_set<tree>::create_ggc (37);
6240
6241 func->used_types_hash->add (type);
6242 }
6243 }
6244
6245 /* Given a type, insert it into the used hash table in cfun. */
6246 void
6247 used_types_insert (tree t)
6248 {
6249 while (POINTER_TYPE_P (t) || TREE_CODE (t) == ARRAY_TYPE)
6250 if (TYPE_NAME (t))
6251 break;
6252 else
6253 t = TREE_TYPE (t);
6254 if (TREE_CODE (t) == ERROR_MARK)
6255 return;
6256 if (TYPE_NAME (t) == NULL_TREE
6257 || TYPE_NAME (t) == TYPE_NAME (TYPE_MAIN_VARIANT (t)))
6258 t = TYPE_MAIN_VARIANT (t);
6259 if (debug_info_level > DINFO_LEVEL_NONE)
6260 {
6261 if (cfun)
6262 used_types_insert_helper (t, cfun);
6263 else
6264 {
6265 /* So this might be a type referenced by a global variable.
6266 Record that type so that we can later decide to emit its
6267 debug information. */
6268 vec_safe_push (types_used_by_cur_var_decl, t);
6269 }
6270 }
6271 }
6272
6273 /* Helper to Hash a struct types_used_by_vars_entry. */
6274
6275 static hashval_t
6276 hash_types_used_by_vars_entry (const struct types_used_by_vars_entry *entry)
6277 {
6278 gcc_assert (entry && entry->var_decl && entry->type);
6279
6280 return iterative_hash_object (entry->type,
6281 iterative_hash_object (entry->var_decl, 0));
6282 }
6283
6284 /* Hash function of the types_used_by_vars_entry hash table. */
6285
6286 hashval_t
6287 used_type_hasher::hash (types_used_by_vars_entry *entry)
6288 {
6289 return hash_types_used_by_vars_entry (entry);
6290 }
6291
6292 /*Equality function of the types_used_by_vars_entry hash table. */
6293
6294 bool
6295 used_type_hasher::equal (types_used_by_vars_entry *e1,
6296 types_used_by_vars_entry *e2)
6297 {
6298 return (e1->var_decl == e2->var_decl && e1->type == e2->type);
6299 }
6300
6301 /* Inserts an entry into the types_used_by_vars_hash hash table. */
6302
6303 void
6304 types_used_by_var_decl_insert (tree type, tree var_decl)
6305 {
6306 if (type != NULL && var_decl != NULL)
6307 {
6308 types_used_by_vars_entry **slot;
6309 struct types_used_by_vars_entry e;
6310 e.var_decl = var_decl;
6311 e.type = type;
6312 if (types_used_by_vars_hash == NULL)
6313 types_used_by_vars_hash
6314 = hash_table<used_type_hasher>::create_ggc (37);
6315
6316 slot = types_used_by_vars_hash->find_slot (&e, INSERT);
6317 if (*slot == NULL)
6318 {
6319 struct types_used_by_vars_entry *entry;
6320 entry = ggc_alloc<types_used_by_vars_entry> ();
6321 entry->type = type;
6322 entry->var_decl = var_decl;
6323 *slot = entry;
6324 }
6325 }
6326 }
6327
6328 namespace {
6329
6330 const pass_data pass_data_leaf_regs =
6331 {
6332 RTL_PASS, /* type */
6333 "*leaf_regs", /* name */
6334 OPTGROUP_NONE, /* optinfo_flags */
6335 TV_NONE, /* tv_id */
6336 0, /* properties_required */
6337 0, /* properties_provided */
6338 0, /* properties_destroyed */
6339 0, /* todo_flags_start */
6340 0, /* todo_flags_finish */
6341 };
6342
6343 class pass_leaf_regs : public rtl_opt_pass
6344 {
6345 public:
6346 pass_leaf_regs (gcc::context *ctxt)
6347 : rtl_opt_pass (pass_data_leaf_regs, ctxt)
6348 {}
6349
6350 /* opt_pass methods: */
6351 virtual unsigned int execute (function *)
6352 {
6353 return rest_of_handle_check_leaf_regs ();
6354 }
6355
6356 }; // class pass_leaf_regs
6357
6358 } // anon namespace
6359
6360 rtl_opt_pass *
6361 make_pass_leaf_regs (gcc::context *ctxt)
6362 {
6363 return new pass_leaf_regs (ctxt);
6364 }
6365
6366 static unsigned int
6367 rest_of_handle_thread_prologue_and_epilogue (void)
6368 {
6369 /* prepare_shrink_wrap is sensitive to the block structure of the control
6370 flow graph, so clean it up first. */
6371 if (optimize)
6372 cleanup_cfg (0);
6373
6374 /* On some machines, the prologue and epilogue code, or parts thereof,
6375 can be represented as RTL. Doing so lets us schedule insns between
6376 it and the rest of the code and also allows delayed branch
6377 scheduling to operate in the epilogue. */
6378 thread_prologue_and_epilogue_insns ();
6379
6380 /* Some non-cold blocks may now be only reachable from cold blocks.
6381 Fix that up. */
6382 fixup_partitions ();
6383
6384 /* Shrink-wrapping can result in unreachable edges in the epilogue,
6385 see PR57320. */
6386 cleanup_cfg (optimize ? CLEANUP_EXPENSIVE : 0);
6387
6388 /* The stack usage info is finalized during prologue expansion. */
6389 if (flag_stack_usage_info)
6390 output_stack_usage ();
6391
6392 return 0;
6393 }
6394
6395 namespace {
6396
6397 const pass_data pass_data_thread_prologue_and_epilogue =
6398 {
6399 RTL_PASS, /* type */
6400 "pro_and_epilogue", /* name */
6401 OPTGROUP_NONE, /* optinfo_flags */
6402 TV_THREAD_PROLOGUE_AND_EPILOGUE, /* tv_id */
6403 0, /* properties_required */
6404 0, /* properties_provided */
6405 0, /* properties_destroyed */
6406 0, /* todo_flags_start */
6407 ( TODO_df_verify | TODO_df_finish ), /* todo_flags_finish */
6408 };
6409
6410 class pass_thread_prologue_and_epilogue : public rtl_opt_pass
6411 {
6412 public:
6413 pass_thread_prologue_and_epilogue (gcc::context *ctxt)
6414 : rtl_opt_pass (pass_data_thread_prologue_and_epilogue, ctxt)
6415 {}
6416
6417 /* opt_pass methods: */
6418 virtual unsigned int execute (function *)
6419 {
6420 return rest_of_handle_thread_prologue_and_epilogue ();
6421 }
6422
6423 }; // class pass_thread_prologue_and_epilogue
6424
6425 } // anon namespace
6426
6427 rtl_opt_pass *
6428 make_pass_thread_prologue_and_epilogue (gcc::context *ctxt)
6429 {
6430 return new pass_thread_prologue_and_epilogue (ctxt);
6431 }
6432 \f
6433
6434 /* This mini-pass fixes fall-out from SSA in asm statements that have
6435 in-out constraints. Say you start with
6436
6437 orig = inout;
6438 asm ("": "+mr" (inout));
6439 use (orig);
6440
6441 which is transformed very early to use explicit output and match operands:
6442
6443 orig = inout;
6444 asm ("": "=mr" (inout) : "0" (inout));
6445 use (orig);
6446
6447 Or, after SSA and copyprop,
6448
6449 asm ("": "=mr" (inout_2) : "0" (inout_1));
6450 use (inout_1);
6451
6452 Clearly inout_2 and inout_1 can't be coalesced easily anymore, as
6453 they represent two separate values, so they will get different pseudo
6454 registers during expansion. Then, since the two operands need to match
6455 per the constraints, but use different pseudo registers, reload can
6456 only register a reload for these operands. But reloads can only be
6457 satisfied by hardregs, not by memory, so we need a register for this
6458 reload, just because we are presented with non-matching operands.
6459 So, even though we allow memory for this operand, no memory can be
6460 used for it, just because the two operands don't match. This can
6461 cause reload failures on register-starved targets.
6462
6463 So it's a symptom of reload not being able to use memory for reloads
6464 or, alternatively it's also a symptom of both operands not coming into
6465 reload as matching (in which case the pseudo could go to memory just
6466 fine, as the alternative allows it, and no reload would be necessary).
6467 We fix the latter problem here, by transforming
6468
6469 asm ("": "=mr" (inout_2) : "0" (inout_1));
6470
6471 back to
6472
6473 inout_2 = inout_1;
6474 asm ("": "=mr" (inout_2) : "0" (inout_2)); */
6475
6476 static void
6477 match_asm_constraints_1 (rtx_insn *insn, rtx *p_sets, int noutputs)
6478 {
6479 int i;
6480 bool changed = false;
6481 rtx op = SET_SRC (p_sets[0]);
6482 int ninputs = ASM_OPERANDS_INPUT_LENGTH (op);
6483 rtvec inputs = ASM_OPERANDS_INPUT_VEC (op);
6484 bool *output_matched = XALLOCAVEC (bool, noutputs);
6485
6486 memset (output_matched, 0, noutputs * sizeof (bool));
6487 for (i = 0; i < ninputs; i++)
6488 {
6489 rtx input, output;
6490 rtx_insn *insns;
6491 const char *constraint = ASM_OPERANDS_INPUT_CONSTRAINT (op, i);
6492 char *end;
6493 int match, j;
6494
6495 if (*constraint == '%')
6496 constraint++;
6497
6498 match = strtoul (constraint, &end, 10);
6499 if (end == constraint)
6500 continue;
6501
6502 gcc_assert (match < noutputs);
6503 output = SET_DEST (p_sets[match]);
6504 input = RTVEC_ELT (inputs, i);
6505 /* Only do the transformation for pseudos. */
6506 if (! REG_P (output)
6507 || rtx_equal_p (output, input)
6508 || (GET_MODE (input) != VOIDmode
6509 && GET_MODE (input) != GET_MODE (output)))
6510 continue;
6511
6512 /* We can't do anything if the output is also used as input,
6513 as we're going to overwrite it. */
6514 for (j = 0; j < ninputs; j++)
6515 if (reg_overlap_mentioned_p (output, RTVEC_ELT (inputs, j)))
6516 break;
6517 if (j != ninputs)
6518 continue;
6519
6520 /* Avoid changing the same input several times. For
6521 asm ("" : "=mr" (out1), "=mr" (out2) : "0" (in), "1" (in));
6522 only change in once (to out1), rather than changing it
6523 first to out1 and afterwards to out2. */
6524 if (i > 0)
6525 {
6526 for (j = 0; j < noutputs; j++)
6527 if (output_matched[j] && input == SET_DEST (p_sets[j]))
6528 break;
6529 if (j != noutputs)
6530 continue;
6531 }
6532 output_matched[match] = true;
6533
6534 start_sequence ();
6535 emit_move_insn (output, input);
6536 insns = get_insns ();
6537 end_sequence ();
6538 emit_insn_before (insns, insn);
6539
6540 /* Now replace all mentions of the input with output. We can't
6541 just replace the occurrence in inputs[i], as the register might
6542 also be used in some other input (or even in an address of an
6543 output), which would mean possibly increasing the number of
6544 inputs by one (namely 'output' in addition), which might pose
6545 a too complicated problem for reload to solve. E.g. this situation:
6546
6547 asm ("" : "=r" (output), "=m" (input) : "0" (input))
6548
6549 Here 'input' is used in two occurrences as input (once for the
6550 input operand, once for the address in the second output operand).
6551 If we would replace only the occurrence of the input operand (to
6552 make the matching) we would be left with this:
6553
6554 output = input
6555 asm ("" : "=r" (output), "=m" (input) : "0" (output))
6556
6557 Now we suddenly have two different input values (containing the same
6558 value, but different pseudos) where we formerly had only one.
6559 With more complicated asms this might lead to reload failures
6560 which wouldn't have happen without this pass. So, iterate over
6561 all operands and replace all occurrences of the register used. */
6562 for (j = 0; j < noutputs; j++)
6563 if (!rtx_equal_p (SET_DEST (p_sets[j]), input)
6564 && reg_overlap_mentioned_p (input, SET_DEST (p_sets[j])))
6565 SET_DEST (p_sets[j]) = replace_rtx (SET_DEST (p_sets[j]),
6566 input, output);
6567 for (j = 0; j < ninputs; j++)
6568 if (reg_overlap_mentioned_p (input, RTVEC_ELT (inputs, j)))
6569 RTVEC_ELT (inputs, j) = replace_rtx (RTVEC_ELT (inputs, j),
6570 input, output);
6571
6572 changed = true;
6573 }
6574
6575 if (changed)
6576 df_insn_rescan (insn);
6577 }
6578
6579 /* Add the decl D to the local_decls list of FUN. */
6580
6581 void
6582 add_local_decl (struct function *fun, tree d)
6583 {
6584 gcc_assert (TREE_CODE (d) == VAR_DECL);
6585 vec_safe_push (fun->local_decls, d);
6586 }
6587
6588 namespace {
6589
6590 const pass_data pass_data_match_asm_constraints =
6591 {
6592 RTL_PASS, /* type */
6593 "asmcons", /* name */
6594 OPTGROUP_NONE, /* optinfo_flags */
6595 TV_NONE, /* tv_id */
6596 0, /* properties_required */
6597 0, /* properties_provided */
6598 0, /* properties_destroyed */
6599 0, /* todo_flags_start */
6600 0, /* todo_flags_finish */
6601 };
6602
6603 class pass_match_asm_constraints : public rtl_opt_pass
6604 {
6605 public:
6606 pass_match_asm_constraints (gcc::context *ctxt)
6607 : rtl_opt_pass (pass_data_match_asm_constraints, ctxt)
6608 {}
6609
6610 /* opt_pass methods: */
6611 virtual unsigned int execute (function *);
6612
6613 }; // class pass_match_asm_constraints
6614
6615 unsigned
6616 pass_match_asm_constraints::execute (function *fun)
6617 {
6618 basic_block bb;
6619 rtx_insn *insn;
6620 rtx pat, *p_sets;
6621 int noutputs;
6622
6623 if (!crtl->has_asm_statement)
6624 return 0;
6625
6626 df_set_flags (DF_DEFER_INSN_RESCAN);
6627 FOR_EACH_BB_FN (bb, fun)
6628 {
6629 FOR_BB_INSNS (bb, insn)
6630 {
6631 if (!INSN_P (insn))
6632 continue;
6633
6634 pat = PATTERN (insn);
6635 if (GET_CODE (pat) == PARALLEL)
6636 p_sets = &XVECEXP (pat, 0, 0), noutputs = XVECLEN (pat, 0);
6637 else if (GET_CODE (pat) == SET)
6638 p_sets = &PATTERN (insn), noutputs = 1;
6639 else
6640 continue;
6641
6642 if (GET_CODE (*p_sets) == SET
6643 && GET_CODE (SET_SRC (*p_sets)) == ASM_OPERANDS)
6644 match_asm_constraints_1 (insn, p_sets, noutputs);
6645 }
6646 }
6647
6648 return TODO_df_finish;
6649 }
6650
6651 } // anon namespace
6652
6653 rtl_opt_pass *
6654 make_pass_match_asm_constraints (gcc::context *ctxt)
6655 {
6656 return new pass_match_asm_constraints (ctxt);
6657 }
6658
6659
6660 #include "gt-function.h"