[Ada] Add special bypass for obsolete code pattern
[official-gcc.git] / gcc / function.c
blob8274975ce33b43bcae3779eed623547279740145
1 /* Expands front end tree to back end RTL for GCC.
2 Copyright (C) 1987-2019 Free Software Foundation, Inc.
4 This file is part of GCC.
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.
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.
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/>. */
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.
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.
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. */
34 #include "config.h"
35 #include "system.h"
36 #include "coretypes.h"
37 #include "backend.h"
38 #include "target.h"
39 #include "rtl.h"
40 #include "tree.h"
41 #include "gimple-expr.h"
42 #include "cfghooks.h"
43 #include "df.h"
44 #include "memmodel.h"
45 #include "tm_p.h"
46 #include "stringpool.h"
47 #include "expmed.h"
48 #include "optabs.h"
49 #include "regs.h"
50 #include "emit-rtl.h"
51 #include "recog.h"
52 #include "rtl-error.h"
53 #include "alias.h"
54 #include "fold-const.h"
55 #include "stor-layout.h"
56 #include "varasm.h"
57 #include "except.h"
58 #include "dojump.h"
59 #include "explow.h"
60 #include "calls.h"
61 #include "expr.h"
62 #include "optabs-tree.h"
63 #include "output.h"
64 #include "langhooks.h"
65 #include "common/common-target.h"
66 #include "gimplify.h"
67 #include "tree-pass.h"
68 #include "cfgrtl.h"
69 #include "cfganal.h"
70 #include "cfgbuild.h"
71 #include "cfgcleanup.h"
72 #include "cfgexpand.h"
73 #include "shrink-wrap.h"
74 #include "toplev.h"
75 #include "rtl-iter.h"
76 #include "tree-dfa.h"
77 #include "tree-ssa.h"
78 #include "stringpool.h"
79 #include "attribs.h"
80 #include "gimple.h"
81 #include "options.h"
83 /* So we can assign to cfun in this file. */
84 #undef cfun
86 #ifndef STACK_ALIGNMENT_NEEDED
87 #define STACK_ALIGNMENT_NEEDED 1
88 #endif
90 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
92 /* Round a value to the lowest integer less than it that is a multiple of
93 the required alignment. Avoid using division in case the value is
94 negative. Assume the alignment is a power of two. */
95 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
97 /* Similar, but round to the next highest integer that meets the
98 alignment. */
99 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
101 /* Nonzero once virtual register instantiation has been done.
102 assign_stack_local uses frame_pointer_rtx when this is nonzero.
103 calls.c:emit_library_call_value_1 uses it to set up
104 post-instantiation libcalls. */
105 int virtuals_instantiated;
107 /* Assign unique numbers to labels generated for profiling, debugging, etc. */
108 static GTY(()) int funcdef_no;
110 /* These variables hold pointers to functions to create and destroy
111 target specific, per-function data structures. */
112 struct machine_function * (*init_machine_status) (void);
114 /* The currently compiled function. */
115 struct function *cfun = 0;
117 /* These hashes record the prologue and epilogue insns. */
119 struct insn_cache_hasher : ggc_cache_ptr_hash<rtx_def>
121 static hashval_t hash (rtx x) { return htab_hash_pointer (x); }
122 static bool equal (rtx a, rtx b) { return a == b; }
125 static GTY((cache))
126 hash_table<insn_cache_hasher> *prologue_insn_hash;
127 static GTY((cache))
128 hash_table<insn_cache_hasher> *epilogue_insn_hash;
131 hash_table<used_type_hasher> *types_used_by_vars_hash = NULL;
132 vec<tree, va_gc> *types_used_by_cur_var_decl;
134 /* Forward declarations. */
136 static class temp_slot *find_temp_slot_from_address (rtx);
137 static void pad_to_arg_alignment (struct args_size *, int, struct args_size *);
138 static void pad_below (struct args_size *, machine_mode, tree);
139 static void reorder_blocks_1 (rtx_insn *, tree, vec<tree> *);
140 static int all_blocks (tree, tree *);
141 static tree *get_block_vector (tree, int *);
142 extern tree debug_find_var_in_block_tree (tree, tree);
143 /* We always define `record_insns' even if it's not used so that we
144 can always export `prologue_epilogue_contains'. */
145 static void record_insns (rtx_insn *, rtx, hash_table<insn_cache_hasher> **)
146 ATTRIBUTE_UNUSED;
147 static bool contains (const rtx_insn *, hash_table<insn_cache_hasher> *);
148 static void prepare_function_start (void);
149 static void do_clobber_return_reg (rtx, void *);
150 static void do_use_return_reg (rtx, void *);
153 /* Stack of nested functions. */
154 /* Keep track of the cfun stack. */
156 static vec<function *> function_context_stack;
158 /* Save the current context for compilation of a nested function.
159 This is called from language-specific code. */
161 void
162 push_function_context (void)
164 if (cfun == 0)
165 allocate_struct_function (NULL, false);
167 function_context_stack.safe_push (cfun);
168 set_cfun (NULL);
171 /* Restore the last saved context, at the end of a nested function.
172 This function is called from language-specific code. */
174 void
175 pop_function_context (void)
177 struct function *p = function_context_stack.pop ();
178 set_cfun (p);
179 current_function_decl = p->decl;
181 /* Reset variables that have known state during rtx generation. */
182 virtuals_instantiated = 0;
183 generating_concat_p = 1;
186 /* Clear out all parts of the state in F that can safely be discarded
187 after the function has been parsed, but not compiled, to let
188 garbage collection reclaim the memory. */
190 void
191 free_after_parsing (struct function *f)
193 f->language = 0;
196 /* Clear out all parts of the state in F that can safely be discarded
197 after the function has been compiled, to let garbage collection
198 reclaim the memory. */
200 void
201 free_after_compilation (struct function *f)
203 prologue_insn_hash = NULL;
204 epilogue_insn_hash = NULL;
206 free (crtl->emit.regno_pointer_align);
208 memset (crtl, 0, sizeof (struct rtl_data));
209 f->eh = NULL;
210 f->machine = NULL;
211 f->cfg = NULL;
212 f->curr_properties &= ~PROP_cfg;
214 regno_reg_rtx = NULL;
217 /* Return size needed for stack frame based on slots so far allocated.
218 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
219 the caller may have to do that. */
221 poly_int64
222 get_frame_size (void)
224 if (FRAME_GROWS_DOWNWARD)
225 return -frame_offset;
226 else
227 return frame_offset;
230 /* Issue an error message and return TRUE if frame OFFSET overflows in
231 the signed target pointer arithmetics for function FUNC. Otherwise
232 return FALSE. */
234 bool
235 frame_offset_overflow (poly_int64 offset, tree func)
237 poly_uint64 size = FRAME_GROWS_DOWNWARD ? -offset : offset;
238 unsigned HOST_WIDE_INT limit
239 = ((HOST_WIDE_INT_1U << (GET_MODE_BITSIZE (Pmode) - 1))
240 /* Leave room for the fixed part of the frame. */
241 - 64 * UNITS_PER_WORD);
243 if (!coeffs_in_range_p (size, 0U, limit))
245 unsigned HOST_WIDE_INT hwisize;
246 if (size.is_constant (&hwisize))
247 error_at (DECL_SOURCE_LOCATION (func),
248 "total size of local objects %wu exceeds maximum %wu",
249 hwisize, limit);
250 else
251 error_at (DECL_SOURCE_LOCATION (func),
252 "total size of local objects exceeds maximum %wu",
253 limit);
254 return true;
257 return false;
260 /* Return the minimum spill slot alignment for a register of mode MODE. */
262 unsigned int
263 spill_slot_alignment (machine_mode mode ATTRIBUTE_UNUSED)
265 return STACK_SLOT_ALIGNMENT (NULL_TREE, mode, GET_MODE_ALIGNMENT (mode));
268 /* Return stack slot alignment in bits for TYPE and MODE. */
270 static unsigned int
271 get_stack_local_alignment (tree type, machine_mode mode)
273 unsigned int alignment;
275 if (mode == BLKmode)
276 alignment = BIGGEST_ALIGNMENT;
277 else
278 alignment = GET_MODE_ALIGNMENT (mode);
280 /* Allow the frond-end to (possibly) increase the alignment of this
281 stack slot. */
282 if (! type)
283 type = lang_hooks.types.type_for_mode (mode, 0);
285 return STACK_SLOT_ALIGNMENT (type, mode, alignment);
288 /* Determine whether it is possible to fit a stack slot of size SIZE and
289 alignment ALIGNMENT into an area in the stack frame that starts at
290 frame offset START and has a length of LENGTH. If so, store the frame
291 offset to be used for the stack slot in *POFFSET and return true;
292 return false otherwise. This function will extend the frame size when
293 given a start/length pair that lies at the end of the frame. */
295 static bool
296 try_fit_stack_local (poly_int64 start, poly_int64 length,
297 poly_int64 size, unsigned int alignment,
298 poly_int64_pod *poffset)
300 poly_int64 this_frame_offset;
301 int frame_off, frame_alignment, frame_phase;
303 /* Calculate how many bytes the start of local variables is off from
304 stack alignment. */
305 frame_alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
306 frame_off = targetm.starting_frame_offset () % frame_alignment;
307 frame_phase = frame_off ? frame_alignment - frame_off : 0;
309 /* Round the frame offset to the specified alignment. */
311 if (FRAME_GROWS_DOWNWARD)
312 this_frame_offset
313 = (aligned_lower_bound (start + length - size - frame_phase, alignment)
314 + frame_phase);
315 else
316 this_frame_offset
317 = aligned_upper_bound (start - frame_phase, alignment) + frame_phase;
319 /* See if it fits. If this space is at the edge of the frame,
320 consider extending the frame to make it fit. Our caller relies on
321 this when allocating a new slot. */
322 if (maybe_lt (this_frame_offset, start))
324 if (known_eq (frame_offset, start))
325 frame_offset = this_frame_offset;
326 else
327 return false;
329 else if (maybe_gt (this_frame_offset + size, start + length))
331 if (known_eq (frame_offset, start + length))
332 frame_offset = this_frame_offset + size;
333 else
334 return false;
337 *poffset = this_frame_offset;
338 return true;
341 /* Create a new frame_space structure describing free space in the stack
342 frame beginning at START and ending at END, and chain it into the
343 function's frame_space_list. */
345 static void
346 add_frame_space (poly_int64 start, poly_int64 end)
348 class frame_space *space = ggc_alloc<frame_space> ();
349 space->next = crtl->frame_space_list;
350 crtl->frame_space_list = space;
351 space->start = start;
352 space->length = end - start;
355 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
356 with machine mode MODE.
358 ALIGN controls the amount of alignment for the address of the slot:
359 0 means according to MODE,
360 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
361 -2 means use BITS_PER_UNIT,
362 positive specifies alignment boundary in bits.
364 KIND has ASLK_REDUCE_ALIGN bit set if it is OK to reduce
365 alignment and ASLK_RECORD_PAD bit set if we should remember
366 extra space we allocated for alignment purposes. When we are
367 called from assign_stack_temp_for_type, it is not set so we don't
368 track the same stack slot in two independent lists.
370 We do not round to stack_boundary here. */
373 assign_stack_local_1 (machine_mode mode, poly_int64 size,
374 int align, int kind)
376 rtx x, addr;
377 poly_int64 bigend_correction = 0;
378 poly_int64 slot_offset = 0, old_frame_offset;
379 unsigned int alignment, alignment_in_bits;
381 if (align == 0)
383 alignment = get_stack_local_alignment (NULL, mode);
384 alignment /= BITS_PER_UNIT;
386 else if (align == -1)
388 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
389 size = aligned_upper_bound (size, alignment);
391 else if (align == -2)
392 alignment = 1; /* BITS_PER_UNIT / BITS_PER_UNIT */
393 else
394 alignment = align / BITS_PER_UNIT;
396 alignment_in_bits = alignment * BITS_PER_UNIT;
398 /* Ignore alignment if it exceeds MAX_SUPPORTED_STACK_ALIGNMENT. */
399 if (alignment_in_bits > MAX_SUPPORTED_STACK_ALIGNMENT)
401 alignment_in_bits = MAX_SUPPORTED_STACK_ALIGNMENT;
402 alignment = MAX_SUPPORTED_STACK_ALIGNMENT / BITS_PER_UNIT;
405 if (SUPPORTS_STACK_ALIGNMENT)
407 if (crtl->stack_alignment_estimated < alignment_in_bits)
409 if (!crtl->stack_realign_processed)
410 crtl->stack_alignment_estimated = alignment_in_bits;
411 else
413 /* If stack is realigned and stack alignment value
414 hasn't been finalized, it is OK not to increase
415 stack_alignment_estimated. The bigger alignment
416 requirement is recorded in stack_alignment_needed
417 below. */
418 gcc_assert (!crtl->stack_realign_finalized);
419 if (!crtl->stack_realign_needed)
421 /* It is OK to reduce the alignment as long as the
422 requested size is 0 or the estimated stack
423 alignment >= mode alignment. */
424 gcc_assert ((kind & ASLK_REDUCE_ALIGN)
425 || known_eq (size, 0)
426 || (crtl->stack_alignment_estimated
427 >= GET_MODE_ALIGNMENT (mode)));
428 alignment_in_bits = crtl->stack_alignment_estimated;
429 alignment = alignment_in_bits / BITS_PER_UNIT;
435 if (crtl->stack_alignment_needed < alignment_in_bits)
436 crtl->stack_alignment_needed = alignment_in_bits;
437 if (crtl->max_used_stack_slot_alignment < alignment_in_bits)
438 crtl->max_used_stack_slot_alignment = alignment_in_bits;
440 if (mode != BLKmode || maybe_ne (size, 0))
442 if (kind & ASLK_RECORD_PAD)
444 class frame_space **psp;
446 for (psp = &crtl->frame_space_list; *psp; psp = &(*psp)->next)
448 class frame_space *space = *psp;
449 if (!try_fit_stack_local (space->start, space->length, size,
450 alignment, &slot_offset))
451 continue;
452 *psp = space->next;
453 if (known_gt (slot_offset, space->start))
454 add_frame_space (space->start, slot_offset);
455 if (known_lt (slot_offset + size, space->start + space->length))
456 add_frame_space (slot_offset + size,
457 space->start + space->length);
458 goto found_space;
462 else if (!STACK_ALIGNMENT_NEEDED)
464 slot_offset = frame_offset;
465 goto found_space;
468 old_frame_offset = frame_offset;
470 if (FRAME_GROWS_DOWNWARD)
472 frame_offset -= size;
473 try_fit_stack_local (frame_offset, size, size, alignment, &slot_offset);
475 if (kind & ASLK_RECORD_PAD)
477 if (known_gt (slot_offset, frame_offset))
478 add_frame_space (frame_offset, slot_offset);
479 if (known_lt (slot_offset + size, old_frame_offset))
480 add_frame_space (slot_offset + size, old_frame_offset);
483 else
485 frame_offset += size;
486 try_fit_stack_local (old_frame_offset, size, size, alignment, &slot_offset);
488 if (kind & ASLK_RECORD_PAD)
490 if (known_gt (slot_offset, old_frame_offset))
491 add_frame_space (old_frame_offset, slot_offset);
492 if (known_lt (slot_offset + size, frame_offset))
493 add_frame_space (slot_offset + size, frame_offset);
497 found_space:
498 /* On a big-endian machine, if we are allocating more space than we will use,
499 use the least significant bytes of those that are allocated. */
500 if (mode != BLKmode)
502 /* The slot size can sometimes be smaller than the mode size;
503 e.g. the rs6000 port allocates slots with a vector mode
504 that have the size of only one element. However, the slot
505 size must always be ordered wrt to the mode size, in the
506 same way as for a subreg. */
507 gcc_checking_assert (ordered_p (GET_MODE_SIZE (mode), size));
508 if (BYTES_BIG_ENDIAN && maybe_lt (GET_MODE_SIZE (mode), size))
509 bigend_correction = size - GET_MODE_SIZE (mode);
512 /* If we have already instantiated virtual registers, return the actual
513 address relative to the frame pointer. */
514 if (virtuals_instantiated)
515 addr = plus_constant (Pmode, frame_pointer_rtx,
516 trunc_int_for_mode
517 (slot_offset + bigend_correction
518 + targetm.starting_frame_offset (), Pmode));
519 else
520 addr = plus_constant (Pmode, virtual_stack_vars_rtx,
521 trunc_int_for_mode
522 (slot_offset + bigend_correction,
523 Pmode));
525 x = gen_rtx_MEM (mode, addr);
526 set_mem_align (x, alignment_in_bits);
527 MEM_NOTRAP_P (x) = 1;
529 vec_safe_push (stack_slot_list, x);
531 if (frame_offset_overflow (frame_offset, current_function_decl))
532 frame_offset = 0;
534 return x;
537 /* Wrap up assign_stack_local_1 with last parameter as false. */
540 assign_stack_local (machine_mode mode, poly_int64 size, int align)
542 return assign_stack_local_1 (mode, size, align, ASLK_RECORD_PAD);
545 /* In order to evaluate some expressions, such as function calls returning
546 structures in memory, we need to temporarily allocate stack locations.
547 We record each allocated temporary in the following structure.
549 Associated with each temporary slot is a nesting level. When we pop up
550 one level, all temporaries associated with the previous level are freed.
551 Normally, all temporaries are freed after the execution of the statement
552 in which they were created. However, if we are inside a ({...}) grouping,
553 the result may be in a temporary and hence must be preserved. If the
554 result could be in a temporary, we preserve it if we can determine which
555 one it is in. If we cannot determine which temporary may contain the
556 result, all temporaries are preserved. A temporary is preserved by
557 pretending it was allocated at the previous nesting level. */
559 class GTY(()) temp_slot {
560 public:
561 /* Points to next temporary slot. */
562 class temp_slot *next;
563 /* Points to previous temporary slot. */
564 class temp_slot *prev;
565 /* The rtx to used to reference the slot. */
566 rtx slot;
567 /* The size, in units, of the slot. */
568 poly_int64 size;
569 /* The type of the object in the slot, or zero if it doesn't correspond
570 to a type. We use this to determine whether a slot can be reused.
571 It can be reused if objects of the type of the new slot will always
572 conflict with objects of the type of the old slot. */
573 tree type;
574 /* The alignment (in bits) of the slot. */
575 unsigned int align;
576 /* Nonzero if this temporary is currently in use. */
577 char in_use;
578 /* Nesting level at which this slot is being used. */
579 int level;
580 /* The offset of the slot from the frame_pointer, including extra space
581 for alignment. This info is for combine_temp_slots. */
582 poly_int64 base_offset;
583 /* The size of the slot, including extra space for alignment. This
584 info is for combine_temp_slots. */
585 poly_int64 full_size;
588 /* Entry for the below hash table. */
589 struct GTY((for_user)) temp_slot_address_entry {
590 hashval_t hash;
591 rtx address;
592 class temp_slot *temp_slot;
595 struct temp_address_hasher : ggc_ptr_hash<temp_slot_address_entry>
597 static hashval_t hash (temp_slot_address_entry *);
598 static bool equal (temp_slot_address_entry *, temp_slot_address_entry *);
601 /* A table of addresses that represent a stack slot. The table is a mapping
602 from address RTXen to a temp slot. */
603 static GTY(()) hash_table<temp_address_hasher> *temp_slot_address_table;
604 static size_t n_temp_slots_in_use;
606 /* Removes temporary slot TEMP from LIST. */
608 static void
609 cut_slot_from_list (class temp_slot *temp, class temp_slot **list)
611 if (temp->next)
612 temp->next->prev = temp->prev;
613 if (temp->prev)
614 temp->prev->next = temp->next;
615 else
616 *list = temp->next;
618 temp->prev = temp->next = NULL;
621 /* Inserts temporary slot TEMP to LIST. */
623 static void
624 insert_slot_to_list (class temp_slot *temp, class temp_slot **list)
626 temp->next = *list;
627 if (*list)
628 (*list)->prev = temp;
629 temp->prev = NULL;
630 *list = temp;
633 /* Returns the list of used temp slots at LEVEL. */
635 static class temp_slot **
636 temp_slots_at_level (int level)
638 if (level >= (int) vec_safe_length (used_temp_slots))
639 vec_safe_grow_cleared (used_temp_slots, level + 1);
641 return &(*used_temp_slots)[level];
644 /* Returns the maximal temporary slot level. */
646 static int
647 max_slot_level (void)
649 if (!used_temp_slots)
650 return -1;
652 return used_temp_slots->length () - 1;
655 /* Moves temporary slot TEMP to LEVEL. */
657 static void
658 move_slot_to_level (class temp_slot *temp, int level)
660 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
661 insert_slot_to_list (temp, temp_slots_at_level (level));
662 temp->level = level;
665 /* Make temporary slot TEMP available. */
667 static void
668 make_slot_available (class temp_slot *temp)
670 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
671 insert_slot_to_list (temp, &avail_temp_slots);
672 temp->in_use = 0;
673 temp->level = -1;
674 n_temp_slots_in_use--;
677 /* Compute the hash value for an address -> temp slot mapping.
678 The value is cached on the mapping entry. */
679 static hashval_t
680 temp_slot_address_compute_hash (struct temp_slot_address_entry *t)
682 int do_not_record = 0;
683 return hash_rtx (t->address, GET_MODE (t->address),
684 &do_not_record, NULL, false);
687 /* Return the hash value for an address -> temp slot mapping. */
688 hashval_t
689 temp_address_hasher::hash (temp_slot_address_entry *t)
691 return t->hash;
694 /* Compare two address -> temp slot mapping entries. */
695 bool
696 temp_address_hasher::equal (temp_slot_address_entry *t1,
697 temp_slot_address_entry *t2)
699 return exp_equiv_p (t1->address, t2->address, 0, true);
702 /* Add ADDRESS as an alias of TEMP_SLOT to the addess -> temp slot mapping. */
703 static void
704 insert_temp_slot_address (rtx address, class temp_slot *temp_slot)
706 struct temp_slot_address_entry *t = ggc_alloc<temp_slot_address_entry> ();
707 t->address = copy_rtx (address);
708 t->temp_slot = temp_slot;
709 t->hash = temp_slot_address_compute_hash (t);
710 *temp_slot_address_table->find_slot_with_hash (t, t->hash, INSERT) = t;
713 /* Remove an address -> temp slot mapping entry if the temp slot is
714 not in use anymore. Callback for remove_unused_temp_slot_addresses. */
716 remove_unused_temp_slot_addresses_1 (temp_slot_address_entry **slot, void *)
718 const struct temp_slot_address_entry *t = *slot;
719 if (! t->temp_slot->in_use)
720 temp_slot_address_table->clear_slot (slot);
721 return 1;
724 /* Remove all mappings of addresses to unused temp slots. */
725 static void
726 remove_unused_temp_slot_addresses (void)
728 /* Use quicker clearing if there aren't any active temp slots. */
729 if (n_temp_slots_in_use)
730 temp_slot_address_table->traverse
731 <void *, remove_unused_temp_slot_addresses_1> (NULL);
732 else
733 temp_slot_address_table->empty ();
736 /* Find the temp slot corresponding to the object at address X. */
738 static class temp_slot *
739 find_temp_slot_from_address (rtx x)
741 class temp_slot *p;
742 struct temp_slot_address_entry tmp, *t;
744 /* First try the easy way:
745 See if X exists in the address -> temp slot mapping. */
746 tmp.address = x;
747 tmp.temp_slot = NULL;
748 tmp.hash = temp_slot_address_compute_hash (&tmp);
749 t = temp_slot_address_table->find_with_hash (&tmp, tmp.hash);
750 if (t)
751 return t->temp_slot;
753 /* If we have a sum involving a register, see if it points to a temp
754 slot. */
755 if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 0))
756 && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
757 return p;
758 else if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 1))
759 && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
760 return p;
762 /* Last resort: Address is a virtual stack var address. */
763 poly_int64 offset;
764 if (strip_offset (x, &offset) == virtual_stack_vars_rtx)
766 int i;
767 for (i = max_slot_level (); i >= 0; i--)
768 for (p = *temp_slots_at_level (i); p; p = p->next)
769 if (known_in_range_p (offset, p->base_offset, p->full_size))
770 return p;
773 return NULL;
776 /* Allocate a temporary stack slot and record it for possible later
777 reuse.
779 MODE is the machine mode to be given to the returned rtx.
781 SIZE is the size in units of the space required. We do no rounding here
782 since assign_stack_local will do any required rounding.
784 TYPE is the type that will be used for the stack slot. */
787 assign_stack_temp_for_type (machine_mode mode, poly_int64 size, tree type)
789 unsigned int align;
790 class temp_slot *p, *best_p = 0, *selected = NULL, **pp;
791 rtx slot;
793 gcc_assert (known_size_p (size));
795 align = get_stack_local_alignment (type, mode);
797 /* Try to find an available, already-allocated temporary of the proper
798 mode which meets the size and alignment requirements. Choose the
799 smallest one with the closest alignment.
801 If assign_stack_temp is called outside of the tree->rtl expansion,
802 we cannot reuse the stack slots (that may still refer to
803 VIRTUAL_STACK_VARS_REGNUM). */
804 if (!virtuals_instantiated)
806 for (p = avail_temp_slots; p; p = p->next)
808 if (p->align >= align
809 && known_ge (p->size, size)
810 && GET_MODE (p->slot) == mode
811 && objects_must_conflict_p (p->type, type)
812 && (best_p == 0
813 || (known_eq (best_p->size, p->size)
814 ? best_p->align > p->align
815 : known_ge (best_p->size, p->size))))
817 if (p->align == align && known_eq (p->size, size))
819 selected = p;
820 cut_slot_from_list (selected, &avail_temp_slots);
821 best_p = 0;
822 break;
824 best_p = p;
829 /* Make our best, if any, the one to use. */
830 if (best_p)
832 selected = best_p;
833 cut_slot_from_list (selected, &avail_temp_slots);
835 /* If there are enough aligned bytes left over, make them into a new
836 temp_slot so that the extra bytes don't get wasted. Do this only
837 for BLKmode slots, so that we can be sure of the alignment. */
838 if (GET_MODE (best_p->slot) == BLKmode)
840 int alignment = best_p->align / BITS_PER_UNIT;
841 poly_int64 rounded_size = aligned_upper_bound (size, alignment);
843 if (known_ge (best_p->size - rounded_size, alignment))
845 p = ggc_alloc<temp_slot> ();
846 p->in_use = 0;
847 p->size = best_p->size - rounded_size;
848 p->base_offset = best_p->base_offset + rounded_size;
849 p->full_size = best_p->full_size - rounded_size;
850 p->slot = adjust_address_nv (best_p->slot, BLKmode, rounded_size);
851 p->align = best_p->align;
852 p->type = best_p->type;
853 insert_slot_to_list (p, &avail_temp_slots);
855 vec_safe_push (stack_slot_list, p->slot);
857 best_p->size = rounded_size;
858 best_p->full_size = rounded_size;
863 /* If we still didn't find one, make a new temporary. */
864 if (selected == 0)
866 poly_int64 frame_offset_old = frame_offset;
868 p = ggc_alloc<temp_slot> ();
870 /* We are passing an explicit alignment request to assign_stack_local.
871 One side effect of that is assign_stack_local will not round SIZE
872 to ensure the frame offset remains suitably aligned.
874 So for requests which depended on the rounding of SIZE, we go ahead
875 and round it now. We also make sure ALIGNMENT is at least
876 BIGGEST_ALIGNMENT. */
877 gcc_assert (mode != BLKmode || align == BIGGEST_ALIGNMENT);
878 p->slot = assign_stack_local_1 (mode,
879 (mode == BLKmode
880 ? aligned_upper_bound (size,
881 (int) align
882 / BITS_PER_UNIT)
883 : size),
884 align, 0);
886 p->align = align;
888 /* The following slot size computation is necessary because we don't
889 know the actual size of the temporary slot until assign_stack_local
890 has performed all the frame alignment and size rounding for the
891 requested temporary. Note that extra space added for alignment
892 can be either above or below this stack slot depending on which
893 way the frame grows. We include the extra space if and only if it
894 is above this slot. */
895 if (FRAME_GROWS_DOWNWARD)
896 p->size = frame_offset_old - frame_offset;
897 else
898 p->size = size;
900 /* Now define the fields used by combine_temp_slots. */
901 if (FRAME_GROWS_DOWNWARD)
903 p->base_offset = frame_offset;
904 p->full_size = frame_offset_old - frame_offset;
906 else
908 p->base_offset = frame_offset_old;
909 p->full_size = frame_offset - frame_offset_old;
912 selected = p;
915 p = selected;
916 p->in_use = 1;
917 p->type = type;
918 p->level = temp_slot_level;
919 n_temp_slots_in_use++;
921 pp = temp_slots_at_level (p->level);
922 insert_slot_to_list (p, pp);
923 insert_temp_slot_address (XEXP (p->slot, 0), p);
925 /* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
926 slot = gen_rtx_MEM (mode, XEXP (p->slot, 0));
927 vec_safe_push (stack_slot_list, slot);
929 /* If we know the alias set for the memory that will be used, use
930 it. If there's no TYPE, then we don't know anything about the
931 alias set for the memory. */
932 set_mem_alias_set (slot, type ? get_alias_set (type) : 0);
933 set_mem_align (slot, align);
935 /* If a type is specified, set the relevant flags. */
936 if (type != 0)
937 MEM_VOLATILE_P (slot) = TYPE_VOLATILE (type);
938 MEM_NOTRAP_P (slot) = 1;
940 return slot;
943 /* Allocate a temporary stack slot and record it for possible later
944 reuse. First two arguments are same as in preceding function. */
947 assign_stack_temp (machine_mode mode, poly_int64 size)
949 return assign_stack_temp_for_type (mode, size, NULL_TREE);
952 /* Assign a temporary.
953 If TYPE_OR_DECL is a decl, then we are doing it on behalf of the decl
954 and so that should be used in error messages. In either case, we
955 allocate of the given type.
956 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
957 it is 0 if a register is OK.
958 DONT_PROMOTE is 1 if we should not promote values in register
959 to wider modes. */
962 assign_temp (tree type_or_decl, int memory_required,
963 int dont_promote ATTRIBUTE_UNUSED)
965 tree type, decl;
966 machine_mode mode;
967 #ifdef PROMOTE_MODE
968 int unsignedp;
969 #endif
971 if (DECL_P (type_or_decl))
972 decl = type_or_decl, type = TREE_TYPE (decl);
973 else
974 decl = NULL, type = type_or_decl;
976 mode = TYPE_MODE (type);
977 #ifdef PROMOTE_MODE
978 unsignedp = TYPE_UNSIGNED (type);
979 #endif
981 /* Allocating temporaries of TREE_ADDRESSABLE type must be done in the front
982 end. See also create_tmp_var for the gimplification-time check. */
983 gcc_assert (!TREE_ADDRESSABLE (type) && COMPLETE_TYPE_P (type));
985 if (mode == BLKmode || memory_required)
987 poly_int64 size;
988 rtx tmp;
990 /* Unfortunately, we don't yet know how to allocate variable-sized
991 temporaries. However, sometimes we can find a fixed upper limit on
992 the size, so try that instead. */
993 if (!poly_int_tree_p (TYPE_SIZE_UNIT (type), &size))
994 size = max_int_size_in_bytes (type);
996 /* Zero sized arrays are a GNU C extension. Set size to 1 to avoid
997 problems with allocating the stack space. */
998 if (known_eq (size, 0))
999 size = 1;
1001 /* The size of the temporary may be too large to fit into an integer. */
1002 /* ??? Not sure this should happen except for user silliness, so limit
1003 this to things that aren't compiler-generated temporaries. The
1004 rest of the time we'll die in assign_stack_temp_for_type. */
1005 if (decl
1006 && !known_size_p (size)
1007 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST)
1009 error ("size of variable %q+D is too large", decl);
1010 size = 1;
1013 tmp = assign_stack_temp_for_type (mode, size, type);
1014 return tmp;
1017 #ifdef PROMOTE_MODE
1018 if (! dont_promote)
1019 mode = promote_mode (type, mode, &unsignedp);
1020 #endif
1022 return gen_reg_rtx (mode);
1025 /* Combine temporary stack slots which are adjacent on the stack.
1027 This allows for better use of already allocated stack space. This is only
1028 done for BLKmode slots because we can be sure that we won't have alignment
1029 problems in this case. */
1031 static void
1032 combine_temp_slots (void)
1034 class temp_slot *p, *q, *next, *next_q;
1035 int num_slots;
1037 /* We can't combine slots, because the information about which slot
1038 is in which alias set will be lost. */
1039 if (flag_strict_aliasing)
1040 return;
1042 /* If there are a lot of temp slots, don't do anything unless
1043 high levels of optimization. */
1044 if (! flag_expensive_optimizations)
1045 for (p = avail_temp_slots, num_slots = 0; p; p = p->next, num_slots++)
1046 if (num_slots > 100 || (num_slots > 10 && optimize == 0))
1047 return;
1049 for (p = avail_temp_slots; p; p = next)
1051 int delete_p = 0;
1053 next = p->next;
1055 if (GET_MODE (p->slot) != BLKmode)
1056 continue;
1058 for (q = p->next; q; q = next_q)
1060 int delete_q = 0;
1062 next_q = q->next;
1064 if (GET_MODE (q->slot) != BLKmode)
1065 continue;
1067 if (known_eq (p->base_offset + p->full_size, q->base_offset))
1069 /* Q comes after P; combine Q into P. */
1070 p->size += q->size;
1071 p->full_size += q->full_size;
1072 delete_q = 1;
1074 else if (known_eq (q->base_offset + q->full_size, p->base_offset))
1076 /* P comes after Q; combine P into Q. */
1077 q->size += p->size;
1078 q->full_size += p->full_size;
1079 delete_p = 1;
1080 break;
1082 if (delete_q)
1083 cut_slot_from_list (q, &avail_temp_slots);
1086 /* Either delete P or advance past it. */
1087 if (delete_p)
1088 cut_slot_from_list (p, &avail_temp_slots);
1092 /* Indicate that NEW_RTX is an alternate way of referring to the temp
1093 slot that previously was known by OLD_RTX. */
1095 void
1096 update_temp_slot_address (rtx old_rtx, rtx new_rtx)
1098 class temp_slot *p;
1100 if (rtx_equal_p (old_rtx, new_rtx))
1101 return;
1103 p = find_temp_slot_from_address (old_rtx);
1105 /* If we didn't find one, see if both OLD_RTX is a PLUS. If so, and
1106 NEW_RTX is a register, see if one operand of the PLUS is a
1107 temporary location. If so, NEW_RTX points into it. Otherwise,
1108 if both OLD_RTX and NEW_RTX are a PLUS and if there is a register
1109 in common between them. If so, try a recursive call on those
1110 values. */
1111 if (p == 0)
1113 if (GET_CODE (old_rtx) != PLUS)
1114 return;
1116 if (REG_P (new_rtx))
1118 update_temp_slot_address (XEXP (old_rtx, 0), new_rtx);
1119 update_temp_slot_address (XEXP (old_rtx, 1), new_rtx);
1120 return;
1122 else if (GET_CODE (new_rtx) != PLUS)
1123 return;
1125 if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 0)))
1126 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 1));
1127 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 0)))
1128 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 1));
1129 else if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 1)))
1130 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 0));
1131 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 1)))
1132 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 0));
1134 return;
1137 /* Otherwise add an alias for the temp's address. */
1138 insert_temp_slot_address (new_rtx, p);
1141 /* If X could be a reference to a temporary slot, mark that slot as
1142 belonging to the to one level higher than the current level. If X
1143 matched one of our slots, just mark that one. Otherwise, we can't
1144 easily predict which it is, so upgrade all of them.
1146 This is called when an ({...}) construct occurs and a statement
1147 returns a value in memory. */
1149 void
1150 preserve_temp_slots (rtx x)
1152 class temp_slot *p = 0, *next;
1154 if (x == 0)
1155 return;
1157 /* If X is a register that is being used as a pointer, see if we have
1158 a temporary slot we know it points to. */
1159 if (REG_P (x) && REG_POINTER (x))
1160 p = find_temp_slot_from_address (x);
1162 /* If X is not in memory or is at a constant address, it cannot be in
1163 a temporary slot. */
1164 if (p == 0 && (!MEM_P (x) || CONSTANT_P (XEXP (x, 0))))
1165 return;
1167 /* First see if we can find a match. */
1168 if (p == 0)
1169 p = find_temp_slot_from_address (XEXP (x, 0));
1171 if (p != 0)
1173 if (p->level == temp_slot_level)
1174 move_slot_to_level (p, temp_slot_level - 1);
1175 return;
1178 /* Otherwise, preserve all non-kept slots at this level. */
1179 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1181 next = p->next;
1182 move_slot_to_level (p, temp_slot_level - 1);
1186 /* Free all temporaries used so far. This is normally called at the
1187 end of generating code for a statement. */
1189 void
1190 free_temp_slots (void)
1192 class temp_slot *p, *next;
1193 bool some_available = false;
1195 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1197 next = p->next;
1198 make_slot_available (p);
1199 some_available = true;
1202 if (some_available)
1204 remove_unused_temp_slot_addresses ();
1205 combine_temp_slots ();
1209 /* Push deeper into the nesting level for stack temporaries. */
1211 void
1212 push_temp_slots (void)
1214 temp_slot_level++;
1217 /* Pop a temporary nesting level. All slots in use in the current level
1218 are freed. */
1220 void
1221 pop_temp_slots (void)
1223 free_temp_slots ();
1224 temp_slot_level--;
1227 /* Initialize temporary slots. */
1229 void
1230 init_temp_slots (void)
1232 /* We have not allocated any temporaries yet. */
1233 avail_temp_slots = 0;
1234 vec_alloc (used_temp_slots, 0);
1235 temp_slot_level = 0;
1236 n_temp_slots_in_use = 0;
1238 /* Set up the table to map addresses to temp slots. */
1239 if (! temp_slot_address_table)
1240 temp_slot_address_table = hash_table<temp_address_hasher>::create_ggc (32);
1241 else
1242 temp_slot_address_table->empty ();
1245 /* Functions and data structures to keep track of the values hard regs
1246 had at the start of the function. */
1248 /* Private type used by get_hard_reg_initial_reg, get_hard_reg_initial_val,
1249 and has_hard_reg_initial_val.. */
1250 struct GTY(()) initial_value_pair {
1251 rtx hard_reg;
1252 rtx pseudo;
1254 /* ??? This could be a VEC but there is currently no way to define an
1255 opaque VEC type. This could be worked around by defining struct
1256 initial_value_pair in function.h. */
1257 struct GTY(()) initial_value_struct {
1258 int num_entries;
1259 int max_entries;
1260 initial_value_pair * GTY ((length ("%h.num_entries"))) entries;
1263 /* If a pseudo represents an initial hard reg (or expression), return
1264 it, else return NULL_RTX. */
1267 get_hard_reg_initial_reg (rtx reg)
1269 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1270 int i;
1272 if (ivs == 0)
1273 return NULL_RTX;
1275 for (i = 0; i < ivs->num_entries; i++)
1276 if (rtx_equal_p (ivs->entries[i].pseudo, reg))
1277 return ivs->entries[i].hard_reg;
1279 return NULL_RTX;
1282 /* Make sure that there's a pseudo register of mode MODE that stores the
1283 initial value of hard register REGNO. Return an rtx for such a pseudo. */
1286 get_hard_reg_initial_val (machine_mode mode, unsigned int regno)
1288 struct initial_value_struct *ivs;
1289 rtx rv;
1291 rv = has_hard_reg_initial_val (mode, regno);
1292 if (rv)
1293 return rv;
1295 ivs = crtl->hard_reg_initial_vals;
1296 if (ivs == 0)
1298 ivs = ggc_alloc<initial_value_struct> ();
1299 ivs->num_entries = 0;
1300 ivs->max_entries = 5;
1301 ivs->entries = ggc_vec_alloc<initial_value_pair> (5);
1302 crtl->hard_reg_initial_vals = ivs;
1305 if (ivs->num_entries >= ivs->max_entries)
1307 ivs->max_entries += 5;
1308 ivs->entries = GGC_RESIZEVEC (initial_value_pair, ivs->entries,
1309 ivs->max_entries);
1312 ivs->entries[ivs->num_entries].hard_reg = gen_rtx_REG (mode, regno);
1313 ivs->entries[ivs->num_entries].pseudo = gen_reg_rtx (mode);
1315 return ivs->entries[ivs->num_entries++].pseudo;
1318 /* See if get_hard_reg_initial_val has been used to create a pseudo
1319 for the initial value of hard register REGNO in mode MODE. Return
1320 the associated pseudo if so, otherwise return NULL. */
1323 has_hard_reg_initial_val (machine_mode mode, unsigned int regno)
1325 struct initial_value_struct *ivs;
1326 int i;
1328 ivs = crtl->hard_reg_initial_vals;
1329 if (ivs != 0)
1330 for (i = 0; i < ivs->num_entries; i++)
1331 if (GET_MODE (ivs->entries[i].hard_reg) == mode
1332 && REGNO (ivs->entries[i].hard_reg) == regno)
1333 return ivs->entries[i].pseudo;
1335 return NULL_RTX;
1338 unsigned int
1339 emit_initial_value_sets (void)
1341 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1342 int i;
1343 rtx_insn *seq;
1345 if (ivs == 0)
1346 return 0;
1348 start_sequence ();
1349 for (i = 0; i < ivs->num_entries; i++)
1350 emit_move_insn (ivs->entries[i].pseudo, ivs->entries[i].hard_reg);
1351 seq = get_insns ();
1352 end_sequence ();
1354 emit_insn_at_entry (seq);
1355 return 0;
1358 /* Return the hardreg-pseudoreg initial values pair entry I and
1359 TRUE if I is a valid entry, or FALSE if I is not a valid entry. */
1360 bool
1361 initial_value_entry (int i, rtx *hreg, rtx *preg)
1363 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1364 if (!ivs || i >= ivs->num_entries)
1365 return false;
1367 *hreg = ivs->entries[i].hard_reg;
1368 *preg = ivs->entries[i].pseudo;
1369 return true;
1372 /* These routines are responsible for converting virtual register references
1373 to the actual hard register references once RTL generation is complete.
1375 The following four variables are used for communication between the
1376 routines. They contain the offsets of the virtual registers from their
1377 respective hard registers. */
1379 static poly_int64 in_arg_offset;
1380 static poly_int64 var_offset;
1381 static poly_int64 dynamic_offset;
1382 static poly_int64 out_arg_offset;
1383 static poly_int64 cfa_offset;
1385 /* In most machines, the stack pointer register is equivalent to the bottom
1386 of the stack. */
1388 #ifndef STACK_POINTER_OFFSET
1389 #define STACK_POINTER_OFFSET 0
1390 #endif
1392 #if defined (REG_PARM_STACK_SPACE) && !defined (INCOMING_REG_PARM_STACK_SPACE)
1393 #define INCOMING_REG_PARM_STACK_SPACE REG_PARM_STACK_SPACE
1394 #endif
1396 /* If not defined, pick an appropriate default for the offset of dynamically
1397 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
1398 INCOMING_REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
1400 #ifndef STACK_DYNAMIC_OFFSET
1402 /* The bottom of the stack points to the actual arguments. If
1403 REG_PARM_STACK_SPACE is defined, this includes the space for the register
1404 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
1405 stack space for register parameters is not pushed by the caller, but
1406 rather part of the fixed stack areas and hence not included in
1407 `crtl->outgoing_args_size'. Nevertheless, we must allow
1408 for it when allocating stack dynamic objects. */
1410 #ifdef INCOMING_REG_PARM_STACK_SPACE
1411 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1412 ((ACCUMULATE_OUTGOING_ARGS \
1413 ? (crtl->outgoing_args_size \
1414 + (OUTGOING_REG_PARM_STACK_SPACE ((!(FNDECL) ? NULL_TREE : TREE_TYPE (FNDECL))) ? 0 \
1415 : INCOMING_REG_PARM_STACK_SPACE (FNDECL))) \
1416 : 0) + (STACK_POINTER_OFFSET))
1417 #else
1418 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1419 ((ACCUMULATE_OUTGOING_ARGS ? crtl->outgoing_args_size : poly_int64 (0)) \
1420 + (STACK_POINTER_OFFSET))
1421 #endif
1422 #endif
1425 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
1426 is a virtual register, return the equivalent hard register and set the
1427 offset indirectly through the pointer. Otherwise, return 0. */
1429 static rtx
1430 instantiate_new_reg (rtx x, poly_int64_pod *poffset)
1432 rtx new_rtx;
1433 poly_int64 offset;
1435 if (x == virtual_incoming_args_rtx)
1437 if (stack_realign_drap)
1439 /* Replace virtual_incoming_args_rtx with internal arg
1440 pointer if DRAP is used to realign stack. */
1441 new_rtx = crtl->args.internal_arg_pointer;
1442 offset = 0;
1444 else
1445 new_rtx = arg_pointer_rtx, offset = in_arg_offset;
1447 else if (x == virtual_stack_vars_rtx)
1448 new_rtx = frame_pointer_rtx, offset = var_offset;
1449 else if (x == virtual_stack_dynamic_rtx)
1450 new_rtx = stack_pointer_rtx, offset = dynamic_offset;
1451 else if (x == virtual_outgoing_args_rtx)
1452 new_rtx = stack_pointer_rtx, offset = out_arg_offset;
1453 else if (x == virtual_cfa_rtx)
1455 #ifdef FRAME_POINTER_CFA_OFFSET
1456 new_rtx = frame_pointer_rtx;
1457 #else
1458 new_rtx = arg_pointer_rtx;
1459 #endif
1460 offset = cfa_offset;
1462 else if (x == virtual_preferred_stack_boundary_rtx)
1464 new_rtx = GEN_INT (crtl->preferred_stack_boundary / BITS_PER_UNIT);
1465 offset = 0;
1467 else
1468 return NULL_RTX;
1470 *poffset = offset;
1471 return new_rtx;
1474 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1475 registers present inside of *LOC. The expression is simplified,
1476 as much as possible, but is not to be considered "valid" in any sense
1477 implied by the target. Return true if any change is made. */
1479 static bool
1480 instantiate_virtual_regs_in_rtx (rtx *loc)
1482 if (!*loc)
1483 return false;
1484 bool changed = false;
1485 subrtx_ptr_iterator::array_type array;
1486 FOR_EACH_SUBRTX_PTR (iter, array, loc, NONCONST)
1488 rtx *loc = *iter;
1489 if (rtx x = *loc)
1491 rtx new_rtx;
1492 poly_int64 offset;
1493 switch (GET_CODE (x))
1495 case REG:
1496 new_rtx = instantiate_new_reg (x, &offset);
1497 if (new_rtx)
1499 *loc = plus_constant (GET_MODE (x), new_rtx, offset);
1500 changed = true;
1502 iter.skip_subrtxes ();
1503 break;
1505 case PLUS:
1506 new_rtx = instantiate_new_reg (XEXP (x, 0), &offset);
1507 if (new_rtx)
1509 XEXP (x, 0) = new_rtx;
1510 *loc = plus_constant (GET_MODE (x), x, offset, true);
1511 changed = true;
1512 iter.skip_subrtxes ();
1513 break;
1516 /* FIXME -- from old code */
1517 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
1518 we can commute the PLUS and SUBREG because pointers into the
1519 frame are well-behaved. */
1520 break;
1522 default:
1523 break;
1527 return changed;
1530 /* A subroutine of instantiate_virtual_regs_in_insn. Return true if X
1531 matches the predicate for insn CODE operand OPERAND. */
1533 static int
1534 safe_insn_predicate (int code, int operand, rtx x)
1536 return code < 0 || insn_operand_matches ((enum insn_code) code, operand, x);
1539 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1540 registers present inside of insn. The result will be a valid insn. */
1542 static void
1543 instantiate_virtual_regs_in_insn (rtx_insn *insn)
1545 poly_int64 offset;
1546 int insn_code, i;
1547 bool any_change = false;
1548 rtx set, new_rtx, x;
1549 rtx_insn *seq;
1551 /* There are some special cases to be handled first. */
1552 set = single_set (insn);
1553 if (set)
1555 /* We're allowed to assign to a virtual register. This is interpreted
1556 to mean that the underlying register gets assigned the inverse
1557 transformation. This is used, for example, in the handling of
1558 non-local gotos. */
1559 new_rtx = instantiate_new_reg (SET_DEST (set), &offset);
1560 if (new_rtx)
1562 start_sequence ();
1564 instantiate_virtual_regs_in_rtx (&SET_SRC (set));
1565 x = simplify_gen_binary (PLUS, GET_MODE (new_rtx), SET_SRC (set),
1566 gen_int_mode (-offset, GET_MODE (new_rtx)));
1567 x = force_operand (x, new_rtx);
1568 if (x != new_rtx)
1569 emit_move_insn (new_rtx, x);
1571 seq = get_insns ();
1572 end_sequence ();
1574 emit_insn_before (seq, insn);
1575 delete_insn (insn);
1576 return;
1579 /* Handle a straight copy from a virtual register by generating a
1580 new add insn. The difference between this and falling through
1581 to the generic case is avoiding a new pseudo and eliminating a
1582 move insn in the initial rtl stream. */
1583 new_rtx = instantiate_new_reg (SET_SRC (set), &offset);
1584 if (new_rtx
1585 && maybe_ne (offset, 0)
1586 && REG_P (SET_DEST (set))
1587 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1589 start_sequence ();
1591 x = expand_simple_binop (GET_MODE (SET_DEST (set)), PLUS, new_rtx,
1592 gen_int_mode (offset,
1593 GET_MODE (SET_DEST (set))),
1594 SET_DEST (set), 1, OPTAB_LIB_WIDEN);
1595 if (x != SET_DEST (set))
1596 emit_move_insn (SET_DEST (set), x);
1598 seq = get_insns ();
1599 end_sequence ();
1601 emit_insn_before (seq, insn);
1602 delete_insn (insn);
1603 return;
1606 extract_insn (insn);
1607 insn_code = INSN_CODE (insn);
1609 /* Handle a plus involving a virtual register by determining if the
1610 operands remain valid if they're modified in place. */
1611 poly_int64 delta;
1612 if (GET_CODE (SET_SRC (set)) == PLUS
1613 && recog_data.n_operands >= 3
1614 && recog_data.operand_loc[1] == &XEXP (SET_SRC (set), 0)
1615 && recog_data.operand_loc[2] == &XEXP (SET_SRC (set), 1)
1616 && poly_int_rtx_p (recog_data.operand[2], &delta)
1617 && (new_rtx = instantiate_new_reg (recog_data.operand[1], &offset)))
1619 offset += delta;
1621 /* If the sum is zero, then replace with a plain move. */
1622 if (known_eq (offset, 0)
1623 && REG_P (SET_DEST (set))
1624 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1626 start_sequence ();
1627 emit_move_insn (SET_DEST (set), new_rtx);
1628 seq = get_insns ();
1629 end_sequence ();
1631 emit_insn_before (seq, insn);
1632 delete_insn (insn);
1633 return;
1636 x = gen_int_mode (offset, recog_data.operand_mode[2]);
1638 /* Using validate_change and apply_change_group here leaves
1639 recog_data in an invalid state. Since we know exactly what
1640 we want to check, do those two by hand. */
1641 if (safe_insn_predicate (insn_code, 1, new_rtx)
1642 && safe_insn_predicate (insn_code, 2, x))
1644 *recog_data.operand_loc[1] = recog_data.operand[1] = new_rtx;
1645 *recog_data.operand_loc[2] = recog_data.operand[2] = x;
1646 any_change = true;
1648 /* Fall through into the regular operand fixup loop in
1649 order to take care of operands other than 1 and 2. */
1653 else
1655 extract_insn (insn);
1656 insn_code = INSN_CODE (insn);
1659 /* In the general case, we expect virtual registers to appear only in
1660 operands, and then only as either bare registers or inside memories. */
1661 for (i = 0; i < recog_data.n_operands; ++i)
1663 x = recog_data.operand[i];
1664 switch (GET_CODE (x))
1666 case MEM:
1668 rtx addr = XEXP (x, 0);
1670 if (!instantiate_virtual_regs_in_rtx (&addr))
1671 continue;
1673 start_sequence ();
1674 x = replace_equiv_address (x, addr, true);
1675 /* It may happen that the address with the virtual reg
1676 was valid (e.g. based on the virtual stack reg, which might
1677 be acceptable to the predicates with all offsets), whereas
1678 the address now isn't anymore, for instance when the address
1679 is still offsetted, but the base reg isn't virtual-stack-reg
1680 anymore. Below we would do a force_reg on the whole operand,
1681 but this insn might actually only accept memory. Hence,
1682 before doing that last resort, try to reload the address into
1683 a register, so this operand stays a MEM. */
1684 if (!safe_insn_predicate (insn_code, i, x))
1686 addr = force_reg (GET_MODE (addr), addr);
1687 x = replace_equiv_address (x, addr, true);
1689 seq = get_insns ();
1690 end_sequence ();
1691 if (seq)
1692 emit_insn_before (seq, insn);
1694 break;
1696 case REG:
1697 new_rtx = instantiate_new_reg (x, &offset);
1698 if (new_rtx == NULL)
1699 continue;
1700 if (known_eq (offset, 0))
1701 x = new_rtx;
1702 else
1704 start_sequence ();
1706 /* Careful, special mode predicates may have stuff in
1707 insn_data[insn_code].operand[i].mode that isn't useful
1708 to us for computing a new value. */
1709 /* ??? Recognize address_operand and/or "p" constraints
1710 to see if (plus new offset) is a valid before we put
1711 this through expand_simple_binop. */
1712 x = expand_simple_binop (GET_MODE (x), PLUS, new_rtx,
1713 gen_int_mode (offset, GET_MODE (x)),
1714 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1715 seq = get_insns ();
1716 end_sequence ();
1717 emit_insn_before (seq, insn);
1719 break;
1721 case SUBREG:
1722 new_rtx = instantiate_new_reg (SUBREG_REG (x), &offset);
1723 if (new_rtx == NULL)
1724 continue;
1725 if (maybe_ne (offset, 0))
1727 start_sequence ();
1728 new_rtx = expand_simple_binop
1729 (GET_MODE (new_rtx), PLUS, new_rtx,
1730 gen_int_mode (offset, GET_MODE (new_rtx)),
1731 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1732 seq = get_insns ();
1733 end_sequence ();
1734 emit_insn_before (seq, insn);
1736 x = simplify_gen_subreg (recog_data.operand_mode[i], new_rtx,
1737 GET_MODE (new_rtx), SUBREG_BYTE (x));
1738 gcc_assert (x);
1739 break;
1741 default:
1742 continue;
1745 /* At this point, X contains the new value for the operand.
1746 Validate the new value vs the insn predicate. Note that
1747 asm insns will have insn_code -1 here. */
1748 if (!safe_insn_predicate (insn_code, i, x))
1750 start_sequence ();
1751 if (REG_P (x))
1753 gcc_assert (REGNO (x) <= LAST_VIRTUAL_REGISTER);
1754 x = copy_to_reg (x);
1756 else
1757 x = force_reg (insn_data[insn_code].operand[i].mode, x);
1758 seq = get_insns ();
1759 end_sequence ();
1760 if (seq)
1761 emit_insn_before (seq, insn);
1764 *recog_data.operand_loc[i] = recog_data.operand[i] = x;
1765 any_change = true;
1768 if (any_change)
1770 /* Propagate operand changes into the duplicates. */
1771 for (i = 0; i < recog_data.n_dups; ++i)
1772 *recog_data.dup_loc[i]
1773 = copy_rtx (recog_data.operand[(unsigned)recog_data.dup_num[i]]);
1775 /* Force re-recognition of the instruction for validation. */
1776 INSN_CODE (insn) = -1;
1779 if (asm_noperands (PATTERN (insn)) >= 0)
1781 if (!check_asm_operands (PATTERN (insn)))
1783 error_for_asm (insn, "impossible constraint in %<asm%>");
1784 /* For asm goto, instead of fixing up all the edges
1785 just clear the template and clear input operands
1786 (asm goto doesn't have any output operands). */
1787 if (JUMP_P (insn))
1789 rtx asm_op = extract_asm_operands (PATTERN (insn));
1790 ASM_OPERANDS_TEMPLATE (asm_op) = ggc_strdup ("");
1791 ASM_OPERANDS_INPUT_VEC (asm_op) = rtvec_alloc (0);
1792 ASM_OPERANDS_INPUT_CONSTRAINT_VEC (asm_op) = rtvec_alloc (0);
1794 else
1795 delete_insn (insn);
1798 else
1800 if (recog_memoized (insn) < 0)
1801 fatal_insn_not_found (insn);
1805 /* Subroutine of instantiate_decls. Given RTL representing a decl,
1806 do any instantiation required. */
1808 void
1809 instantiate_decl_rtl (rtx x)
1811 rtx addr;
1813 if (x == 0)
1814 return;
1816 /* If this is a CONCAT, recurse for the pieces. */
1817 if (GET_CODE (x) == CONCAT)
1819 instantiate_decl_rtl (XEXP (x, 0));
1820 instantiate_decl_rtl (XEXP (x, 1));
1821 return;
1824 /* If this is not a MEM, no need to do anything. Similarly if the
1825 address is a constant or a register that is not a virtual register. */
1826 if (!MEM_P (x))
1827 return;
1829 addr = XEXP (x, 0);
1830 if (CONSTANT_P (addr)
1831 || (REG_P (addr)
1832 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
1833 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
1834 return;
1836 instantiate_virtual_regs_in_rtx (&XEXP (x, 0));
1839 /* Helper for instantiate_decls called via walk_tree: Process all decls
1840 in the given DECL_VALUE_EXPR. */
1842 static tree
1843 instantiate_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1845 tree t = *tp;
1846 if (! EXPR_P (t))
1848 *walk_subtrees = 0;
1849 if (DECL_P (t))
1851 if (DECL_RTL_SET_P (t))
1852 instantiate_decl_rtl (DECL_RTL (t));
1853 if (TREE_CODE (t) == PARM_DECL && DECL_NAMELESS (t)
1854 && DECL_INCOMING_RTL (t))
1855 instantiate_decl_rtl (DECL_INCOMING_RTL (t));
1856 if ((VAR_P (t) || TREE_CODE (t) == RESULT_DECL)
1857 && DECL_HAS_VALUE_EXPR_P (t))
1859 tree v = DECL_VALUE_EXPR (t);
1860 walk_tree (&v, instantiate_expr, NULL, NULL);
1864 return NULL;
1867 /* Subroutine of instantiate_decls: Process all decls in the given
1868 BLOCK node and all its subblocks. */
1870 static void
1871 instantiate_decls_1 (tree let)
1873 tree t;
1875 for (t = BLOCK_VARS (let); t; t = DECL_CHAIN (t))
1877 if (DECL_RTL_SET_P (t))
1878 instantiate_decl_rtl (DECL_RTL (t));
1879 if (VAR_P (t) && DECL_HAS_VALUE_EXPR_P (t))
1881 tree v = DECL_VALUE_EXPR (t);
1882 walk_tree (&v, instantiate_expr, NULL, NULL);
1886 /* Process all subblocks. */
1887 for (t = BLOCK_SUBBLOCKS (let); t; t = BLOCK_CHAIN (t))
1888 instantiate_decls_1 (t);
1891 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1892 all virtual registers in their DECL_RTL's. */
1894 static void
1895 instantiate_decls (tree fndecl)
1897 tree decl;
1898 unsigned ix;
1900 /* Process all parameters of the function. */
1901 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = DECL_CHAIN (decl))
1903 instantiate_decl_rtl (DECL_RTL (decl));
1904 instantiate_decl_rtl (DECL_INCOMING_RTL (decl));
1905 if (DECL_HAS_VALUE_EXPR_P (decl))
1907 tree v = DECL_VALUE_EXPR (decl);
1908 walk_tree (&v, instantiate_expr, NULL, NULL);
1912 if ((decl = DECL_RESULT (fndecl))
1913 && TREE_CODE (decl) == RESULT_DECL)
1915 if (DECL_RTL_SET_P (decl))
1916 instantiate_decl_rtl (DECL_RTL (decl));
1917 if (DECL_HAS_VALUE_EXPR_P (decl))
1919 tree v = DECL_VALUE_EXPR (decl);
1920 walk_tree (&v, instantiate_expr, NULL, NULL);
1924 /* Process the saved static chain if it exists. */
1925 decl = DECL_STRUCT_FUNCTION (fndecl)->static_chain_decl;
1926 if (decl && DECL_HAS_VALUE_EXPR_P (decl))
1927 instantiate_decl_rtl (DECL_RTL (DECL_VALUE_EXPR (decl)));
1929 /* Now process all variables defined in the function or its subblocks. */
1930 if (DECL_INITIAL (fndecl))
1931 instantiate_decls_1 (DECL_INITIAL (fndecl));
1933 FOR_EACH_LOCAL_DECL (cfun, ix, decl)
1934 if (DECL_RTL_SET_P (decl))
1935 instantiate_decl_rtl (DECL_RTL (decl));
1936 vec_free (cfun->local_decls);
1939 /* Pass through the INSNS of function FNDECL and convert virtual register
1940 references to hard register references. */
1942 static unsigned int
1943 instantiate_virtual_regs (void)
1945 rtx_insn *insn;
1947 /* Compute the offsets to use for this function. */
1948 in_arg_offset = FIRST_PARM_OFFSET (current_function_decl);
1949 var_offset = targetm.starting_frame_offset ();
1950 dynamic_offset = STACK_DYNAMIC_OFFSET (current_function_decl);
1951 out_arg_offset = STACK_POINTER_OFFSET;
1952 #ifdef FRAME_POINTER_CFA_OFFSET
1953 cfa_offset = FRAME_POINTER_CFA_OFFSET (current_function_decl);
1954 #else
1955 cfa_offset = ARG_POINTER_CFA_OFFSET (current_function_decl);
1956 #endif
1958 /* Initialize recognition, indicating that volatile is OK. */
1959 init_recog ();
1961 /* Scan through all the insns, instantiating every virtual register still
1962 present. */
1963 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
1964 if (INSN_P (insn))
1966 /* These patterns in the instruction stream can never be recognized.
1967 Fortunately, they shouldn't contain virtual registers either. */
1968 if (GET_CODE (PATTERN (insn)) == USE
1969 || GET_CODE (PATTERN (insn)) == CLOBBER
1970 || GET_CODE (PATTERN (insn)) == ASM_INPUT
1971 || DEBUG_MARKER_INSN_P (insn))
1972 continue;
1973 else if (DEBUG_BIND_INSN_P (insn))
1974 instantiate_virtual_regs_in_rtx (INSN_VAR_LOCATION_PTR (insn));
1975 else
1976 instantiate_virtual_regs_in_insn (insn);
1978 if (insn->deleted ())
1979 continue;
1981 instantiate_virtual_regs_in_rtx (&REG_NOTES (insn));
1983 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
1984 if (CALL_P (insn))
1985 instantiate_virtual_regs_in_rtx (&CALL_INSN_FUNCTION_USAGE (insn));
1988 /* Instantiate the virtual registers in the DECLs for debugging purposes. */
1989 instantiate_decls (current_function_decl);
1991 targetm.instantiate_decls ();
1993 /* Indicate that, from now on, assign_stack_local should use
1994 frame_pointer_rtx. */
1995 virtuals_instantiated = 1;
1997 return 0;
2000 namespace {
2002 const pass_data pass_data_instantiate_virtual_regs =
2004 RTL_PASS, /* type */
2005 "vregs", /* name */
2006 OPTGROUP_NONE, /* optinfo_flags */
2007 TV_NONE, /* tv_id */
2008 0, /* properties_required */
2009 0, /* properties_provided */
2010 0, /* properties_destroyed */
2011 0, /* todo_flags_start */
2012 0, /* todo_flags_finish */
2015 class pass_instantiate_virtual_regs : public rtl_opt_pass
2017 public:
2018 pass_instantiate_virtual_regs (gcc::context *ctxt)
2019 : rtl_opt_pass (pass_data_instantiate_virtual_regs, ctxt)
2022 /* opt_pass methods: */
2023 virtual unsigned int execute (function *)
2025 return instantiate_virtual_regs ();
2028 }; // class pass_instantiate_virtual_regs
2030 } // anon namespace
2032 rtl_opt_pass *
2033 make_pass_instantiate_virtual_regs (gcc::context *ctxt)
2035 return new pass_instantiate_virtual_regs (ctxt);
2039 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
2040 This means a type for which function calls must pass an address to the
2041 function or get an address back from the function.
2042 EXP may be a type node or an expression (whose type is tested). */
2045 aggregate_value_p (const_tree exp, const_tree fntype)
2047 const_tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
2048 int i, regno, nregs;
2049 rtx reg;
2051 if (fntype)
2052 switch (TREE_CODE (fntype))
2054 case CALL_EXPR:
2056 tree fndecl = get_callee_fndecl (fntype);
2057 if (fndecl)
2058 fntype = TREE_TYPE (fndecl);
2059 else if (CALL_EXPR_FN (fntype))
2060 fntype = TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (fntype)));
2061 else
2062 /* For internal functions, assume nothing needs to be
2063 returned in memory. */
2064 return 0;
2066 break;
2067 case FUNCTION_DECL:
2068 fntype = TREE_TYPE (fntype);
2069 break;
2070 case FUNCTION_TYPE:
2071 case METHOD_TYPE:
2072 break;
2073 case IDENTIFIER_NODE:
2074 fntype = NULL_TREE;
2075 break;
2076 default:
2077 /* We don't expect other tree types here. */
2078 gcc_unreachable ();
2081 if (VOID_TYPE_P (type))
2082 return 0;
2084 /* If a record should be passed the same as its first (and only) member
2085 don't pass it as an aggregate. */
2086 if (TREE_CODE (type) == RECORD_TYPE && TYPE_TRANSPARENT_AGGR (type))
2087 return aggregate_value_p (first_field (type), fntype);
2089 /* If the front end has decided that this needs to be passed by
2090 reference, do so. */
2091 if ((TREE_CODE (exp) == PARM_DECL || TREE_CODE (exp) == RESULT_DECL)
2092 && DECL_BY_REFERENCE (exp))
2093 return 1;
2095 /* Function types that are TREE_ADDRESSABLE force return in memory. */
2096 if (fntype && TREE_ADDRESSABLE (fntype))
2097 return 1;
2099 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
2100 and thus can't be returned in registers. */
2101 if (TREE_ADDRESSABLE (type))
2102 return 1;
2104 if (TYPE_EMPTY_P (type))
2105 return 0;
2107 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
2108 return 1;
2110 if (targetm.calls.return_in_memory (type, fntype))
2111 return 1;
2113 /* Make sure we have suitable call-clobbered regs to return
2114 the value in; if not, we must return it in memory. */
2115 reg = hard_function_value (type, 0, fntype, 0);
2117 /* If we have something other than a REG (e.g. a PARALLEL), then assume
2118 it is OK. */
2119 if (!REG_P (reg))
2120 return 0;
2122 regno = REGNO (reg);
2123 nregs = hard_regno_nregs (regno, TYPE_MODE (type));
2124 for (i = 0; i < nregs; i++)
2125 if (! call_used_regs[regno + i])
2126 return 1;
2128 return 0;
2131 /* Return true if we should assign DECL a pseudo register; false if it
2132 should live on the local stack. */
2134 bool
2135 use_register_for_decl (const_tree decl)
2137 if (TREE_CODE (decl) == SSA_NAME)
2139 /* We often try to use the SSA_NAME, instead of its underlying
2140 decl, to get type information and guide decisions, to avoid
2141 differences of behavior between anonymous and named
2142 variables, but in this one case we have to go for the actual
2143 variable if there is one. The main reason is that, at least
2144 at -O0, we want to place user variables on the stack, but we
2145 don't mind using pseudos for anonymous or ignored temps.
2146 Should we take the SSA_NAME, we'd conclude all SSA_NAMEs
2147 should go in pseudos, whereas their corresponding variables
2148 might have to go on the stack. So, disregarding the decl
2149 here would negatively impact debug info at -O0, enable
2150 coalescing between SSA_NAMEs that ought to get different
2151 stack/pseudo assignments, and get the incoming argument
2152 processing thoroughly confused by PARM_DECLs expected to live
2153 in stack slots but assigned to pseudos. */
2154 if (!SSA_NAME_VAR (decl))
2155 return TYPE_MODE (TREE_TYPE (decl)) != BLKmode
2156 && !(flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)));
2158 decl = SSA_NAME_VAR (decl);
2161 /* Honor volatile. */
2162 if (TREE_SIDE_EFFECTS (decl))
2163 return false;
2165 /* Honor addressability. */
2166 if (TREE_ADDRESSABLE (decl))
2167 return false;
2169 /* RESULT_DECLs are a bit special in that they're assigned without
2170 regard to use_register_for_decl, but we generally only store in
2171 them. If we coalesce their SSA NAMEs, we'd better return a
2172 result that matches the assignment in expand_function_start. */
2173 if (TREE_CODE (decl) == RESULT_DECL)
2175 /* If it's not an aggregate, we're going to use a REG or a
2176 PARALLEL containing a REG. */
2177 if (!aggregate_value_p (decl, current_function_decl))
2178 return true;
2180 /* If expand_function_start determines the return value, we'll
2181 use MEM if it's not by reference. */
2182 if (cfun->returns_pcc_struct
2183 || (targetm.calls.struct_value_rtx
2184 (TREE_TYPE (current_function_decl), 1)))
2185 return DECL_BY_REFERENCE (decl);
2187 /* Otherwise, we're taking an extra all.function_result_decl
2188 argument. It's set up in assign_parms_augmented_arg_list,
2189 under the (negated) conditions above, and then it's used to
2190 set up the RESULT_DECL rtl in assign_params, after looping
2191 over all parameters. Now, if the RESULT_DECL is not by
2192 reference, we'll use a MEM either way. */
2193 if (!DECL_BY_REFERENCE (decl))
2194 return false;
2196 /* Otherwise, if RESULT_DECL is DECL_BY_REFERENCE, it will take
2197 the function_result_decl's assignment. Since it's a pointer,
2198 we can short-circuit a number of the tests below, and we must
2199 duplicat e them because we don't have the
2200 function_result_decl to test. */
2201 if (!targetm.calls.allocate_stack_slots_for_args ())
2202 return true;
2203 /* We don't set DECL_IGNORED_P for the function_result_decl. */
2204 if (optimize)
2205 return true;
2206 /* We don't set DECL_REGISTER for the function_result_decl. */
2207 return false;
2210 /* Only register-like things go in registers. */
2211 if (DECL_MODE (decl) == BLKmode)
2212 return false;
2214 /* If -ffloat-store specified, don't put explicit float variables
2215 into registers. */
2216 /* ??? This should be checked after DECL_ARTIFICIAL, but tree-ssa
2217 propagates values across these stores, and it probably shouldn't. */
2218 if (flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)))
2219 return false;
2221 if (!targetm.calls.allocate_stack_slots_for_args ())
2222 return true;
2224 /* If we're not interested in tracking debugging information for
2225 this decl, then we can certainly put it in a register. */
2226 if (DECL_IGNORED_P (decl))
2227 return true;
2229 if (optimize)
2230 return true;
2232 if (!DECL_REGISTER (decl))
2233 return false;
2235 /* When not optimizing, disregard register keyword for types that
2236 could have methods, otherwise the methods won't be callable from
2237 the debugger. */
2238 if (RECORD_OR_UNION_TYPE_P (TREE_TYPE (decl)))
2239 return false;
2241 return true;
2244 /* Structures to communicate between the subroutines of assign_parms.
2245 The first holds data persistent across all parameters, the second
2246 is cleared out for each parameter. */
2248 struct assign_parm_data_all
2250 /* When INIT_CUMULATIVE_ARGS gets revamped, allocating CUMULATIVE_ARGS
2251 should become a job of the target or otherwise encapsulated. */
2252 CUMULATIVE_ARGS args_so_far_v;
2253 cumulative_args_t args_so_far;
2254 struct args_size stack_args_size;
2255 tree function_result_decl;
2256 tree orig_fnargs;
2257 rtx_insn *first_conversion_insn;
2258 rtx_insn *last_conversion_insn;
2259 HOST_WIDE_INT pretend_args_size;
2260 HOST_WIDE_INT extra_pretend_bytes;
2261 int reg_parm_stack_space;
2264 struct assign_parm_data_one
2266 tree nominal_type;
2267 tree passed_type;
2268 rtx entry_parm;
2269 rtx stack_parm;
2270 machine_mode nominal_mode;
2271 machine_mode passed_mode;
2272 machine_mode promoted_mode;
2273 struct locate_and_pad_arg_data locate;
2274 int partial;
2275 BOOL_BITFIELD named_arg : 1;
2276 BOOL_BITFIELD passed_pointer : 1;
2279 /* A subroutine of assign_parms. Initialize ALL. */
2281 static void
2282 assign_parms_initialize_all (struct assign_parm_data_all *all)
2284 tree fntype ATTRIBUTE_UNUSED;
2286 memset (all, 0, sizeof (*all));
2288 fntype = TREE_TYPE (current_function_decl);
2290 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
2291 INIT_CUMULATIVE_INCOMING_ARGS (all->args_so_far_v, fntype, NULL_RTX);
2292 #else
2293 INIT_CUMULATIVE_ARGS (all->args_so_far_v, fntype, NULL_RTX,
2294 current_function_decl, -1);
2295 #endif
2296 all->args_so_far = pack_cumulative_args (&all->args_so_far_v);
2298 #ifdef INCOMING_REG_PARM_STACK_SPACE
2299 all->reg_parm_stack_space
2300 = INCOMING_REG_PARM_STACK_SPACE (current_function_decl);
2301 #endif
2304 /* If ARGS contains entries with complex types, split the entry into two
2305 entries of the component type. Return a new list of substitutions are
2306 needed, else the old list. */
2308 static void
2309 split_complex_args (vec<tree> *args)
2311 unsigned i;
2312 tree p;
2314 FOR_EACH_VEC_ELT (*args, i, p)
2316 tree type = TREE_TYPE (p);
2317 if (TREE_CODE (type) == COMPLEX_TYPE
2318 && targetm.calls.split_complex_arg (type))
2320 tree decl;
2321 tree subtype = TREE_TYPE (type);
2322 bool addressable = TREE_ADDRESSABLE (p);
2324 /* Rewrite the PARM_DECL's type with its component. */
2325 p = copy_node (p);
2326 TREE_TYPE (p) = subtype;
2327 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
2328 SET_DECL_MODE (p, VOIDmode);
2329 DECL_SIZE (p) = NULL;
2330 DECL_SIZE_UNIT (p) = NULL;
2331 /* If this arg must go in memory, put it in a pseudo here.
2332 We can't allow it to go in memory as per normal parms,
2333 because the usual place might not have the imag part
2334 adjacent to the real part. */
2335 DECL_ARTIFICIAL (p) = addressable;
2336 DECL_IGNORED_P (p) = addressable;
2337 TREE_ADDRESSABLE (p) = 0;
2338 layout_decl (p, 0);
2339 (*args)[i] = p;
2341 /* Build a second synthetic decl. */
2342 decl = build_decl (EXPR_LOCATION (p),
2343 PARM_DECL, NULL_TREE, subtype);
2344 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
2345 DECL_ARTIFICIAL (decl) = addressable;
2346 DECL_IGNORED_P (decl) = addressable;
2347 layout_decl (decl, 0);
2348 args->safe_insert (++i, decl);
2353 /* A subroutine of assign_parms. Adjust the parameter list to incorporate
2354 the hidden struct return argument, and (abi willing) complex args.
2355 Return the new parameter list. */
2357 static vec<tree>
2358 assign_parms_augmented_arg_list (struct assign_parm_data_all *all)
2360 tree fndecl = current_function_decl;
2361 tree fntype = TREE_TYPE (fndecl);
2362 vec<tree> fnargs = vNULL;
2363 tree arg;
2365 for (arg = DECL_ARGUMENTS (fndecl); arg; arg = DECL_CHAIN (arg))
2366 fnargs.safe_push (arg);
2368 all->orig_fnargs = DECL_ARGUMENTS (fndecl);
2370 /* If struct value address is treated as the first argument, make it so. */
2371 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
2372 && ! cfun->returns_pcc_struct
2373 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
2375 tree type = build_pointer_type (TREE_TYPE (fntype));
2376 tree decl;
2378 decl = build_decl (DECL_SOURCE_LOCATION (fndecl),
2379 PARM_DECL, get_identifier (".result_ptr"), type);
2380 DECL_ARG_TYPE (decl) = type;
2381 DECL_ARTIFICIAL (decl) = 1;
2382 DECL_NAMELESS (decl) = 1;
2383 TREE_CONSTANT (decl) = 1;
2384 /* We don't set DECL_IGNORED_P or DECL_REGISTER here. If this
2385 changes, the end of the RESULT_DECL handling block in
2386 use_register_for_decl must be adjusted to match. */
2388 DECL_CHAIN (decl) = all->orig_fnargs;
2389 all->orig_fnargs = decl;
2390 fnargs.safe_insert (0, decl);
2392 all->function_result_decl = decl;
2395 /* If the target wants to split complex arguments into scalars, do so. */
2396 if (targetm.calls.split_complex_arg)
2397 split_complex_args (&fnargs);
2399 return fnargs;
2402 /* A subroutine of assign_parms. Examine PARM and pull out type and mode
2403 data for the parameter. Incorporate ABI specifics such as pass-by-
2404 reference and type promotion. */
2406 static void
2407 assign_parm_find_data_types (struct assign_parm_data_all *all, tree parm,
2408 struct assign_parm_data_one *data)
2410 tree nominal_type, passed_type;
2411 machine_mode nominal_mode, passed_mode, promoted_mode;
2412 int unsignedp;
2414 memset (data, 0, sizeof (*data));
2416 /* NAMED_ARG is a misnomer. We really mean 'non-variadic'. */
2417 if (!cfun->stdarg)
2418 data->named_arg = 1; /* No variadic parms. */
2419 else if (DECL_CHAIN (parm))
2420 data->named_arg = 1; /* Not the last non-variadic parm. */
2421 else if (targetm.calls.strict_argument_naming (all->args_so_far))
2422 data->named_arg = 1; /* Only variadic ones are unnamed. */
2423 else
2424 data->named_arg = 0; /* Treat as variadic. */
2426 nominal_type = TREE_TYPE (parm);
2427 passed_type = DECL_ARG_TYPE (parm);
2429 /* Look out for errors propagating this far. Also, if the parameter's
2430 type is void then its value doesn't matter. */
2431 if (TREE_TYPE (parm) == error_mark_node
2432 /* This can happen after weird syntax errors
2433 or if an enum type is defined among the parms. */
2434 || TREE_CODE (parm) != PARM_DECL
2435 || passed_type == NULL
2436 || VOID_TYPE_P (nominal_type))
2438 nominal_type = passed_type = void_type_node;
2439 nominal_mode = passed_mode = promoted_mode = VOIDmode;
2440 goto egress;
2443 /* Find mode of arg as it is passed, and mode of arg as it should be
2444 during execution of this function. */
2445 passed_mode = TYPE_MODE (passed_type);
2446 nominal_mode = TYPE_MODE (nominal_type);
2448 /* If the parm is to be passed as a transparent union or record, use the
2449 type of the first field for the tests below. We have already verified
2450 that the modes are the same. */
2451 if ((TREE_CODE (passed_type) == UNION_TYPE
2452 || TREE_CODE (passed_type) == RECORD_TYPE)
2453 && TYPE_TRANSPARENT_AGGR (passed_type))
2454 passed_type = TREE_TYPE (first_field (passed_type));
2456 /* See if this arg was passed by invisible reference. */
2457 if (pass_by_reference (&all->args_so_far_v, passed_mode,
2458 passed_type, data->named_arg))
2460 passed_type = nominal_type = build_pointer_type (passed_type);
2461 data->passed_pointer = true;
2462 passed_mode = nominal_mode = TYPE_MODE (nominal_type);
2465 /* Find mode as it is passed by the ABI. */
2466 unsignedp = TYPE_UNSIGNED (passed_type);
2467 promoted_mode = promote_function_mode (passed_type, passed_mode, &unsignedp,
2468 TREE_TYPE (current_function_decl), 0);
2470 egress:
2471 data->nominal_type = nominal_type;
2472 data->passed_type = passed_type;
2473 data->nominal_mode = nominal_mode;
2474 data->passed_mode = passed_mode;
2475 data->promoted_mode = promoted_mode;
2478 /* A subroutine of assign_parms. Invoke setup_incoming_varargs. */
2480 static void
2481 assign_parms_setup_varargs (struct assign_parm_data_all *all,
2482 struct assign_parm_data_one *data, bool no_rtl)
2484 int varargs_pretend_bytes = 0;
2486 targetm.calls.setup_incoming_varargs (all->args_so_far,
2487 data->promoted_mode,
2488 data->passed_type,
2489 &varargs_pretend_bytes, no_rtl);
2491 /* If the back-end has requested extra stack space, record how much is
2492 needed. Do not change pretend_args_size otherwise since it may be
2493 nonzero from an earlier partial argument. */
2494 if (varargs_pretend_bytes > 0)
2495 all->pretend_args_size = varargs_pretend_bytes;
2498 /* A subroutine of assign_parms. Set DATA->ENTRY_PARM corresponding to
2499 the incoming location of the current parameter. */
2501 static void
2502 assign_parm_find_entry_rtl (struct assign_parm_data_all *all,
2503 struct assign_parm_data_one *data)
2505 HOST_WIDE_INT pretend_bytes = 0;
2506 rtx entry_parm;
2507 bool in_regs;
2509 if (data->promoted_mode == VOIDmode)
2511 data->entry_parm = data->stack_parm = const0_rtx;
2512 return;
2515 targetm.calls.warn_parameter_passing_abi (all->args_so_far,
2516 data->passed_type);
2518 entry_parm = targetm.calls.function_incoming_arg (all->args_so_far,
2519 data->promoted_mode,
2520 data->passed_type,
2521 data->named_arg);
2523 if (entry_parm == 0)
2524 data->promoted_mode = data->passed_mode;
2526 /* Determine parm's home in the stack, in case it arrives in the stack
2527 or we should pretend it did. Compute the stack position and rtx where
2528 the argument arrives and its size.
2530 There is one complexity here: If this was a parameter that would
2531 have been passed in registers, but wasn't only because it is
2532 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2533 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2534 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of 0
2535 as it was the previous time. */
2536 in_regs = (entry_parm != 0);
2537 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2538 in_regs = true;
2539 #endif
2540 if (!in_regs && !data->named_arg)
2542 if (targetm.calls.pretend_outgoing_varargs_named (all->args_so_far))
2544 rtx tem;
2545 tem = targetm.calls.function_incoming_arg (all->args_so_far,
2546 data->promoted_mode,
2547 data->passed_type, true);
2548 in_regs = tem != NULL;
2552 /* If this parameter was passed both in registers and in the stack, use
2553 the copy on the stack. */
2554 if (targetm.calls.must_pass_in_stack (data->promoted_mode,
2555 data->passed_type))
2556 entry_parm = 0;
2558 if (entry_parm)
2560 int partial;
2562 partial = targetm.calls.arg_partial_bytes (all->args_so_far,
2563 data->promoted_mode,
2564 data->passed_type,
2565 data->named_arg);
2566 data->partial = partial;
2568 /* The caller might already have allocated stack space for the
2569 register parameters. */
2570 if (partial != 0 && all->reg_parm_stack_space == 0)
2572 /* Part of this argument is passed in registers and part
2573 is passed on the stack. Ask the prologue code to extend
2574 the stack part so that we can recreate the full value.
2576 PRETEND_BYTES is the size of the registers we need to store.
2577 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
2578 stack space that the prologue should allocate.
2580 Internally, gcc assumes that the argument pointer is aligned
2581 to STACK_BOUNDARY bits. This is used both for alignment
2582 optimizations (see init_emit) and to locate arguments that are
2583 aligned to more than PARM_BOUNDARY bits. We must preserve this
2584 invariant by rounding CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to
2585 a stack boundary. */
2587 /* We assume at most one partial arg, and it must be the first
2588 argument on the stack. */
2589 gcc_assert (!all->extra_pretend_bytes && !all->pretend_args_size);
2591 pretend_bytes = partial;
2592 all->pretend_args_size = CEIL_ROUND (pretend_bytes, STACK_BYTES);
2594 /* We want to align relative to the actual stack pointer, so
2595 don't include this in the stack size until later. */
2596 all->extra_pretend_bytes = all->pretend_args_size;
2600 locate_and_pad_parm (data->promoted_mode, data->passed_type, in_regs,
2601 all->reg_parm_stack_space,
2602 entry_parm ? data->partial : 0, current_function_decl,
2603 &all->stack_args_size, &data->locate);
2605 /* Update parm_stack_boundary if this parameter is passed in the
2606 stack. */
2607 if (!in_regs && crtl->parm_stack_boundary < data->locate.boundary)
2608 crtl->parm_stack_boundary = data->locate.boundary;
2610 /* Adjust offsets to include the pretend args. */
2611 pretend_bytes = all->extra_pretend_bytes - pretend_bytes;
2612 data->locate.slot_offset.constant += pretend_bytes;
2613 data->locate.offset.constant += pretend_bytes;
2615 data->entry_parm = entry_parm;
2618 /* A subroutine of assign_parms. If there is actually space on the stack
2619 for this parm, count it in stack_args_size and return true. */
2621 static bool
2622 assign_parm_is_stack_parm (struct assign_parm_data_all *all,
2623 struct assign_parm_data_one *data)
2625 /* Trivially true if we've no incoming register. */
2626 if (data->entry_parm == NULL)
2628 /* Also true if we're partially in registers and partially not,
2629 since we've arranged to drop the entire argument on the stack. */
2630 else if (data->partial != 0)
2632 /* Also true if the target says that it's passed in both registers
2633 and on the stack. */
2634 else if (GET_CODE (data->entry_parm) == PARALLEL
2635 && XEXP (XVECEXP (data->entry_parm, 0, 0), 0) == NULL_RTX)
2637 /* Also true if the target says that there's stack allocated for
2638 all register parameters. */
2639 else if (all->reg_parm_stack_space > 0)
2641 /* Otherwise, no, this parameter has no ABI defined stack slot. */
2642 else
2643 return false;
2645 all->stack_args_size.constant += data->locate.size.constant;
2646 if (data->locate.size.var)
2647 ADD_PARM_SIZE (all->stack_args_size, data->locate.size.var);
2649 return true;
2652 /* A subroutine of assign_parms. Given that this parameter is allocated
2653 stack space by the ABI, find it. */
2655 static void
2656 assign_parm_find_stack_rtl (tree parm, struct assign_parm_data_one *data)
2658 rtx offset_rtx, stack_parm;
2659 unsigned int align, boundary;
2661 /* If we're passing this arg using a reg, make its stack home the
2662 aligned stack slot. */
2663 if (data->entry_parm)
2664 offset_rtx = ARGS_SIZE_RTX (data->locate.slot_offset);
2665 else
2666 offset_rtx = ARGS_SIZE_RTX (data->locate.offset);
2668 stack_parm = crtl->args.internal_arg_pointer;
2669 if (offset_rtx != const0_rtx)
2670 stack_parm = gen_rtx_PLUS (Pmode, stack_parm, offset_rtx);
2671 stack_parm = gen_rtx_MEM (data->promoted_mode, stack_parm);
2673 if (!data->passed_pointer)
2675 set_mem_attributes (stack_parm, parm, 1);
2676 /* set_mem_attributes could set MEM_SIZE to the passed mode's size,
2677 while promoted mode's size is needed. */
2678 if (data->promoted_mode != BLKmode
2679 && data->promoted_mode != DECL_MODE (parm))
2681 set_mem_size (stack_parm, GET_MODE_SIZE (data->promoted_mode));
2682 if (MEM_EXPR (stack_parm) && MEM_OFFSET_KNOWN_P (stack_parm))
2684 poly_int64 offset = subreg_lowpart_offset (DECL_MODE (parm),
2685 data->promoted_mode);
2686 if (maybe_ne (offset, 0))
2687 set_mem_offset (stack_parm, MEM_OFFSET (stack_parm) - offset);
2692 boundary = data->locate.boundary;
2693 align = BITS_PER_UNIT;
2695 /* If we're padding upward, we know that the alignment of the slot
2696 is TARGET_FUNCTION_ARG_BOUNDARY. If we're using slot_offset, we're
2697 intentionally forcing upward padding. Otherwise we have to come
2698 up with a guess at the alignment based on OFFSET_RTX. */
2699 poly_int64 offset;
2700 if (data->locate.where_pad != PAD_DOWNWARD || data->entry_parm)
2701 align = boundary;
2702 else if (poly_int_rtx_p (offset_rtx, &offset))
2704 align = least_bit_hwi (boundary);
2705 unsigned int offset_align = known_alignment (offset) * BITS_PER_UNIT;
2706 if (offset_align != 0)
2707 align = MIN (align, offset_align);
2709 set_mem_align (stack_parm, align);
2711 if (data->entry_parm)
2712 set_reg_attrs_for_parm (data->entry_parm, stack_parm);
2714 data->stack_parm = stack_parm;
2717 /* A subroutine of assign_parms. Adjust DATA->ENTRY_RTL such that it's
2718 always valid and contiguous. */
2720 static void
2721 assign_parm_adjust_entry_rtl (struct assign_parm_data_one *data)
2723 rtx entry_parm = data->entry_parm;
2724 rtx stack_parm = data->stack_parm;
2726 /* If this parm was passed part in regs and part in memory, pretend it
2727 arrived entirely in memory by pushing the register-part onto the stack.
2728 In the special case of a DImode or DFmode that is split, we could put
2729 it together in a pseudoreg directly, but for now that's not worth
2730 bothering with. */
2731 if (data->partial != 0)
2733 /* Handle calls that pass values in multiple non-contiguous
2734 locations. The Irix 6 ABI has examples of this. */
2735 if (GET_CODE (entry_parm) == PARALLEL)
2736 emit_group_store (validize_mem (copy_rtx (stack_parm)), entry_parm,
2737 data->passed_type,
2738 int_size_in_bytes (data->passed_type));
2739 else
2741 gcc_assert (data->partial % UNITS_PER_WORD == 0);
2742 move_block_from_reg (REGNO (entry_parm),
2743 validize_mem (copy_rtx (stack_parm)),
2744 data->partial / UNITS_PER_WORD);
2747 entry_parm = stack_parm;
2750 /* If we didn't decide this parm came in a register, by default it came
2751 on the stack. */
2752 else if (entry_parm == NULL)
2753 entry_parm = stack_parm;
2755 /* When an argument is passed in multiple locations, we can't make use
2756 of this information, but we can save some copying if the whole argument
2757 is passed in a single register. */
2758 else if (GET_CODE (entry_parm) == PARALLEL
2759 && data->nominal_mode != BLKmode
2760 && data->passed_mode != BLKmode)
2762 size_t i, len = XVECLEN (entry_parm, 0);
2764 for (i = 0; i < len; i++)
2765 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
2766 && REG_P (XEXP (XVECEXP (entry_parm, 0, i), 0))
2767 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
2768 == data->passed_mode)
2769 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
2771 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
2772 break;
2776 data->entry_parm = entry_parm;
2779 /* A subroutine of assign_parms. Reconstitute any values which were
2780 passed in multiple registers and would fit in a single register. */
2782 static void
2783 assign_parm_remove_parallels (struct assign_parm_data_one *data)
2785 rtx entry_parm = data->entry_parm;
2787 /* Convert the PARALLEL to a REG of the same mode as the parallel.
2788 This can be done with register operations rather than on the
2789 stack, even if we will store the reconstituted parameter on the
2790 stack later. */
2791 if (GET_CODE (entry_parm) == PARALLEL && GET_MODE (entry_parm) != BLKmode)
2793 rtx parmreg = gen_reg_rtx (GET_MODE (entry_parm));
2794 emit_group_store (parmreg, entry_parm, data->passed_type,
2795 GET_MODE_SIZE (GET_MODE (entry_parm)));
2796 entry_parm = parmreg;
2799 data->entry_parm = entry_parm;
2802 /* A subroutine of assign_parms. Adjust DATA->STACK_RTL such that it's
2803 always valid and properly aligned. */
2805 static void
2806 assign_parm_adjust_stack_rtl (struct assign_parm_data_one *data)
2808 rtx stack_parm = data->stack_parm;
2810 /* If we can't trust the parm stack slot to be aligned enough for its
2811 ultimate type, don't use that slot after entry. We'll make another
2812 stack slot, if we need one. */
2813 if (stack_parm
2814 && ((GET_MODE_ALIGNMENT (data->nominal_mode) > MEM_ALIGN (stack_parm)
2815 && targetm.slow_unaligned_access (data->nominal_mode,
2816 MEM_ALIGN (stack_parm)))
2817 || (data->nominal_type
2818 && TYPE_ALIGN (data->nominal_type) > MEM_ALIGN (stack_parm)
2819 && MEM_ALIGN (stack_parm) < PREFERRED_STACK_BOUNDARY)))
2820 stack_parm = NULL;
2822 /* If parm was passed in memory, and we need to convert it on entry,
2823 don't store it back in that same slot. */
2824 else if (data->entry_parm == stack_parm
2825 && data->nominal_mode != BLKmode
2826 && data->nominal_mode != data->passed_mode)
2827 stack_parm = NULL;
2829 /* If stack protection is in effect for this function, don't leave any
2830 pointers in their passed stack slots. */
2831 else if (crtl->stack_protect_guard
2832 && (flag_stack_protect == 2
2833 || data->passed_pointer
2834 || POINTER_TYPE_P (data->nominal_type)))
2835 stack_parm = NULL;
2837 data->stack_parm = stack_parm;
2840 /* A subroutine of assign_parms. Return true if the current parameter
2841 should be stored as a BLKmode in the current frame. */
2843 static bool
2844 assign_parm_setup_block_p (struct assign_parm_data_one *data)
2846 if (data->nominal_mode == BLKmode)
2847 return true;
2848 if (GET_MODE (data->entry_parm) == BLKmode)
2849 return true;
2851 #ifdef BLOCK_REG_PADDING
2852 /* Only assign_parm_setup_block knows how to deal with register arguments
2853 that are padded at the least significant end. */
2854 if (REG_P (data->entry_parm)
2855 && known_lt (GET_MODE_SIZE (data->promoted_mode), UNITS_PER_WORD)
2856 && (BLOCK_REG_PADDING (data->passed_mode, data->passed_type, 1)
2857 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
2858 return true;
2859 #endif
2861 return false;
2864 /* A subroutine of assign_parms. Arrange for the parameter to be
2865 present and valid in DATA->STACK_RTL. */
2867 static void
2868 assign_parm_setup_block (struct assign_parm_data_all *all,
2869 tree parm, struct assign_parm_data_one *data)
2871 rtx entry_parm = data->entry_parm;
2872 rtx stack_parm = data->stack_parm;
2873 rtx target_reg = NULL_RTX;
2874 bool in_conversion_seq = false;
2875 HOST_WIDE_INT size;
2876 HOST_WIDE_INT size_stored;
2878 if (GET_CODE (entry_parm) == PARALLEL)
2879 entry_parm = emit_group_move_into_temps (entry_parm);
2881 /* If we want the parameter in a pseudo, don't use a stack slot. */
2882 if (is_gimple_reg (parm) && use_register_for_decl (parm))
2884 tree def = ssa_default_def (cfun, parm);
2885 gcc_assert (def);
2886 machine_mode mode = promote_ssa_mode (def, NULL);
2887 rtx reg = gen_reg_rtx (mode);
2888 if (GET_CODE (reg) != CONCAT)
2889 stack_parm = reg;
2890 else
2892 target_reg = reg;
2893 /* Avoid allocating a stack slot, if there isn't one
2894 preallocated by the ABI. It might seem like we should
2895 always prefer a pseudo, but converting between
2896 floating-point and integer modes goes through the stack
2897 on various machines, so it's better to use the reserved
2898 stack slot than to risk wasting it and allocating more
2899 for the conversion. */
2900 if (stack_parm == NULL_RTX)
2902 int save = generating_concat_p;
2903 generating_concat_p = 0;
2904 stack_parm = gen_reg_rtx (mode);
2905 generating_concat_p = save;
2908 data->stack_parm = NULL;
2911 size = int_size_in_bytes (data->passed_type);
2912 size_stored = CEIL_ROUND (size, UNITS_PER_WORD);
2913 if (stack_parm == 0)
2915 HOST_WIDE_INT parm_align
2916 = (STRICT_ALIGNMENT
2917 ? MAX (DECL_ALIGN (parm), BITS_PER_WORD) : DECL_ALIGN (parm));
2919 SET_DECL_ALIGN (parm, parm_align);
2920 if (DECL_ALIGN (parm) > MAX_SUPPORTED_STACK_ALIGNMENT)
2922 rtx allocsize = gen_int_mode (size_stored, Pmode);
2923 get_dynamic_stack_size (&allocsize, 0, DECL_ALIGN (parm), NULL);
2924 stack_parm = assign_stack_local (BLKmode, UINTVAL (allocsize),
2925 MAX_SUPPORTED_STACK_ALIGNMENT);
2926 rtx addr = align_dynamic_address (XEXP (stack_parm, 0),
2927 DECL_ALIGN (parm));
2928 mark_reg_pointer (addr, DECL_ALIGN (parm));
2929 stack_parm = gen_rtx_MEM (GET_MODE (stack_parm), addr);
2930 MEM_NOTRAP_P (stack_parm) = 1;
2932 else
2933 stack_parm = assign_stack_local (BLKmode, size_stored,
2934 DECL_ALIGN (parm));
2935 if (known_eq (GET_MODE_SIZE (GET_MODE (entry_parm)), size))
2936 PUT_MODE (stack_parm, GET_MODE (entry_parm));
2937 set_mem_attributes (stack_parm, parm, 1);
2940 /* If a BLKmode arrives in registers, copy it to a stack slot. Handle
2941 calls that pass values in multiple non-contiguous locations. */
2942 if (REG_P (entry_parm) || GET_CODE (entry_parm) == PARALLEL)
2944 rtx mem;
2946 /* Note that we will be storing an integral number of words.
2947 So we have to be careful to ensure that we allocate an
2948 integral number of words. We do this above when we call
2949 assign_stack_local if space was not allocated in the argument
2950 list. If it was, this will not work if PARM_BOUNDARY is not
2951 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2952 if it becomes a problem. Exception is when BLKmode arrives
2953 with arguments not conforming to word_mode. */
2955 if (data->stack_parm == 0)
2957 else if (GET_CODE (entry_parm) == PARALLEL)
2959 else
2960 gcc_assert (!size || !(PARM_BOUNDARY % BITS_PER_WORD));
2962 mem = validize_mem (copy_rtx (stack_parm));
2964 /* Handle values in multiple non-contiguous locations. */
2965 if (GET_CODE (entry_parm) == PARALLEL && !MEM_P (mem))
2966 emit_group_store (mem, entry_parm, data->passed_type, size);
2967 else if (GET_CODE (entry_parm) == PARALLEL)
2969 push_to_sequence2 (all->first_conversion_insn,
2970 all->last_conversion_insn);
2971 emit_group_store (mem, entry_parm, data->passed_type, size);
2972 all->first_conversion_insn = get_insns ();
2973 all->last_conversion_insn = get_last_insn ();
2974 end_sequence ();
2975 in_conversion_seq = true;
2978 else if (size == 0)
2981 /* If SIZE is that of a mode no bigger than a word, just use
2982 that mode's store operation. */
2983 else if (size <= UNITS_PER_WORD)
2985 unsigned int bits = size * BITS_PER_UNIT;
2986 machine_mode mode = int_mode_for_size (bits, 0).else_blk ();
2988 if (mode != BLKmode
2989 #ifdef BLOCK_REG_PADDING
2990 && (size == UNITS_PER_WORD
2991 || (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2992 != (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
2993 #endif
2996 rtx reg;
2998 /* We are really truncating a word_mode value containing
2999 SIZE bytes into a value of mode MODE. If such an
3000 operation requires no actual instructions, we can refer
3001 to the value directly in mode MODE, otherwise we must
3002 start with the register in word_mode and explicitly
3003 convert it. */
3004 if (targetm.truly_noop_truncation (size * BITS_PER_UNIT,
3005 BITS_PER_WORD))
3006 reg = gen_rtx_REG (mode, REGNO (entry_parm));
3007 else
3009 reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
3010 reg = convert_to_mode (mode, copy_to_reg (reg), 1);
3012 emit_move_insn (change_address (mem, mode, 0), reg);
3015 #ifdef BLOCK_REG_PADDING
3016 /* Storing the register in memory as a full word, as
3017 move_block_from_reg below would do, and then using the
3018 MEM in a smaller mode, has the effect of shifting right
3019 if BYTES_BIG_ENDIAN. If we're bypassing memory, the
3020 shifting must be explicit. */
3021 else if (!MEM_P (mem))
3023 rtx x;
3025 /* If the assert below fails, we should have taken the
3026 mode != BLKmode path above, unless we have downward
3027 padding of smaller-than-word arguments on a machine
3028 with little-endian bytes, which would likely require
3029 additional changes to work correctly. */
3030 gcc_checking_assert (BYTES_BIG_ENDIAN
3031 && (BLOCK_REG_PADDING (mode,
3032 data->passed_type, 1)
3033 == PAD_UPWARD));
3035 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
3037 x = gen_rtx_REG (word_mode, REGNO (entry_parm));
3038 x = expand_shift (RSHIFT_EXPR, word_mode, x, by,
3039 NULL_RTX, 1);
3040 x = force_reg (word_mode, x);
3041 x = gen_lowpart_SUBREG (GET_MODE (mem), x);
3043 emit_move_insn (mem, x);
3045 #endif
3047 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
3048 machine must be aligned to the left before storing
3049 to memory. Note that the previous test doesn't
3050 handle all cases (e.g. SIZE == 3). */
3051 else if (size != UNITS_PER_WORD
3052 #ifdef BLOCK_REG_PADDING
3053 && (BLOCK_REG_PADDING (mode, data->passed_type, 1)
3054 == PAD_DOWNWARD)
3055 #else
3056 && BYTES_BIG_ENDIAN
3057 #endif
3060 rtx tem, x;
3061 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
3062 rtx reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
3064 x = expand_shift (LSHIFT_EXPR, word_mode, reg, by, NULL_RTX, 1);
3065 tem = change_address (mem, word_mode, 0);
3066 emit_move_insn (tem, x);
3068 else
3069 move_block_from_reg (REGNO (entry_parm), mem,
3070 size_stored / UNITS_PER_WORD);
3072 else if (!MEM_P (mem))
3074 gcc_checking_assert (size > UNITS_PER_WORD);
3075 #ifdef BLOCK_REG_PADDING
3076 gcc_checking_assert (BLOCK_REG_PADDING (GET_MODE (mem),
3077 data->passed_type, 0)
3078 == PAD_UPWARD);
3079 #endif
3080 emit_move_insn (mem, entry_parm);
3082 else
3083 move_block_from_reg (REGNO (entry_parm), mem,
3084 size_stored / UNITS_PER_WORD);
3086 else if (data->stack_parm == 0)
3088 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3089 emit_block_move (stack_parm, data->entry_parm, GEN_INT (size),
3090 BLOCK_OP_NORMAL);
3091 all->first_conversion_insn = get_insns ();
3092 all->last_conversion_insn = get_last_insn ();
3093 end_sequence ();
3094 in_conversion_seq = true;
3097 if (target_reg)
3099 if (!in_conversion_seq)
3100 emit_move_insn (target_reg, stack_parm);
3101 else
3103 push_to_sequence2 (all->first_conversion_insn,
3104 all->last_conversion_insn);
3105 emit_move_insn (target_reg, stack_parm);
3106 all->first_conversion_insn = get_insns ();
3107 all->last_conversion_insn = get_last_insn ();
3108 end_sequence ();
3110 stack_parm = target_reg;
3113 data->stack_parm = stack_parm;
3114 set_parm_rtl (parm, stack_parm);
3117 /* A subroutine of assign_parms. Allocate a pseudo to hold the current
3118 parameter. Get it there. Perform all ABI specified conversions. */
3120 static void
3121 assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm,
3122 struct assign_parm_data_one *data)
3124 rtx parmreg, validated_mem;
3125 rtx equiv_stack_parm;
3126 machine_mode promoted_nominal_mode;
3127 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (parm));
3128 bool did_conversion = false;
3129 bool need_conversion, moved;
3130 rtx rtl;
3132 /* Store the parm in a pseudoregister during the function, but we may
3133 need to do it in a wider mode. Using 2 here makes the result
3134 consistent with promote_decl_mode and thus expand_expr_real_1. */
3135 promoted_nominal_mode
3136 = promote_function_mode (data->nominal_type, data->nominal_mode, &unsignedp,
3137 TREE_TYPE (current_function_decl), 2);
3139 parmreg = gen_reg_rtx (promoted_nominal_mode);
3140 if (!DECL_ARTIFICIAL (parm))
3141 mark_user_reg (parmreg);
3143 /* If this was an item that we received a pointer to,
3144 set rtl appropriately. */
3145 if (data->passed_pointer)
3147 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data->passed_type)), parmreg);
3148 set_mem_attributes (rtl, parm, 1);
3150 else
3151 rtl = parmreg;
3153 assign_parm_remove_parallels (data);
3155 /* Copy the value into the register, thus bridging between
3156 assign_parm_find_data_types and expand_expr_real_1. */
3158 equiv_stack_parm = data->stack_parm;
3159 validated_mem = validize_mem (copy_rtx (data->entry_parm));
3161 need_conversion = (data->nominal_mode != data->passed_mode
3162 || promoted_nominal_mode != data->promoted_mode);
3163 moved = false;
3165 if (need_conversion
3166 && GET_MODE_CLASS (data->nominal_mode) == MODE_INT
3167 && data->nominal_mode == data->passed_mode
3168 && data->nominal_mode == GET_MODE (data->entry_parm))
3170 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
3171 mode, by the caller. We now have to convert it to
3172 NOMINAL_MODE, if different. However, PARMREG may be in
3173 a different mode than NOMINAL_MODE if it is being stored
3174 promoted.
3176 If ENTRY_PARM is a hard register, it might be in a register
3177 not valid for operating in its mode (e.g., an odd-numbered
3178 register for a DFmode). In that case, moves are the only
3179 thing valid, so we can't do a convert from there. This
3180 occurs when the calling sequence allow such misaligned
3181 usages.
3183 In addition, the conversion may involve a call, which could
3184 clobber parameters which haven't been copied to pseudo
3185 registers yet.
3187 First, we try to emit an insn which performs the necessary
3188 conversion. We verify that this insn does not clobber any
3189 hard registers. */
3191 enum insn_code icode;
3192 rtx op0, op1;
3194 icode = can_extend_p (promoted_nominal_mode, data->passed_mode,
3195 unsignedp);
3197 op0 = parmreg;
3198 op1 = validated_mem;
3199 if (icode != CODE_FOR_nothing
3200 && insn_operand_matches (icode, 0, op0)
3201 && insn_operand_matches (icode, 1, op1))
3203 enum rtx_code code = unsignedp ? ZERO_EXTEND : SIGN_EXTEND;
3204 rtx_insn *insn, *insns;
3205 rtx t = op1;
3206 HARD_REG_SET hardregs;
3208 start_sequence ();
3209 /* If op1 is a hard register that is likely spilled, first
3210 force it into a pseudo, otherwise combiner might extend
3211 its lifetime too much. */
3212 if (GET_CODE (t) == SUBREG)
3213 t = SUBREG_REG (t);
3214 if (REG_P (t)
3215 && HARD_REGISTER_P (t)
3216 && ! TEST_HARD_REG_BIT (fixed_reg_set, REGNO (t))
3217 && targetm.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (t))))
3219 t = gen_reg_rtx (GET_MODE (op1));
3220 emit_move_insn (t, op1);
3222 else
3223 t = op1;
3224 rtx_insn *pat = gen_extend_insn (op0, t, promoted_nominal_mode,
3225 data->passed_mode, unsignedp);
3226 emit_insn (pat);
3227 insns = get_insns ();
3229 moved = true;
3230 CLEAR_HARD_REG_SET (hardregs);
3231 for (insn = insns; insn && moved; insn = NEXT_INSN (insn))
3233 if (INSN_P (insn))
3234 note_stores (PATTERN (insn), record_hard_reg_sets,
3235 &hardregs);
3236 if (!hard_reg_set_empty_p (hardregs))
3237 moved = false;
3240 end_sequence ();
3242 if (moved)
3244 emit_insn (insns);
3245 if (equiv_stack_parm != NULL_RTX)
3246 equiv_stack_parm = gen_rtx_fmt_e (code, GET_MODE (parmreg),
3247 equiv_stack_parm);
3252 if (moved)
3253 /* Nothing to do. */
3255 else if (need_conversion)
3257 /* We did not have an insn to convert directly, or the sequence
3258 generated appeared unsafe. We must first copy the parm to a
3259 pseudo reg, and save the conversion until after all
3260 parameters have been moved. */
3262 int save_tree_used;
3263 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
3265 emit_move_insn (tempreg, validated_mem);
3267 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3268 tempreg = convert_to_mode (data->nominal_mode, tempreg, unsignedp);
3270 if (partial_subreg_p (tempreg)
3271 && GET_MODE (tempreg) == data->nominal_mode
3272 && REG_P (SUBREG_REG (tempreg))
3273 && data->nominal_mode == data->passed_mode
3274 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (data->entry_parm))
3276 /* The argument is already sign/zero extended, so note it
3277 into the subreg. */
3278 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
3279 SUBREG_PROMOTED_SET (tempreg, unsignedp);
3282 /* TREE_USED gets set erroneously during expand_assignment. */
3283 save_tree_used = TREE_USED (parm);
3284 SET_DECL_RTL (parm, rtl);
3285 expand_assignment (parm, make_tree (data->nominal_type, tempreg), false);
3286 SET_DECL_RTL (parm, NULL_RTX);
3287 TREE_USED (parm) = save_tree_used;
3288 all->first_conversion_insn = get_insns ();
3289 all->last_conversion_insn = get_last_insn ();
3290 end_sequence ();
3292 did_conversion = true;
3294 else
3295 emit_move_insn (parmreg, validated_mem);
3297 /* If we were passed a pointer but the actual value can safely live
3298 in a register, retrieve it and use it directly. */
3299 if (data->passed_pointer && TYPE_MODE (TREE_TYPE (parm)) != BLKmode)
3301 /* We can't use nominal_mode, because it will have been set to
3302 Pmode above. We must use the actual mode of the parm. */
3303 if (use_register_for_decl (parm))
3305 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
3306 mark_user_reg (parmreg);
3308 else
3310 int align = STACK_SLOT_ALIGNMENT (TREE_TYPE (parm),
3311 TYPE_MODE (TREE_TYPE (parm)),
3312 TYPE_ALIGN (TREE_TYPE (parm)));
3313 parmreg
3314 = assign_stack_local (TYPE_MODE (TREE_TYPE (parm)),
3315 GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (parm))),
3316 align);
3317 set_mem_attributes (parmreg, parm, 1);
3320 /* We need to preserve an address based on VIRTUAL_STACK_VARS_REGNUM for
3321 the debug info in case it is not legitimate. */
3322 if (GET_MODE (parmreg) != GET_MODE (rtl))
3324 rtx tempreg = gen_reg_rtx (GET_MODE (rtl));
3325 int unsigned_p = TYPE_UNSIGNED (TREE_TYPE (parm));
3327 push_to_sequence2 (all->first_conversion_insn,
3328 all->last_conversion_insn);
3329 emit_move_insn (tempreg, rtl);
3330 tempreg = convert_to_mode (GET_MODE (parmreg), tempreg, unsigned_p);
3331 emit_move_insn (MEM_P (parmreg) ? copy_rtx (parmreg) : parmreg,
3332 tempreg);
3333 all->first_conversion_insn = get_insns ();
3334 all->last_conversion_insn = get_last_insn ();
3335 end_sequence ();
3337 did_conversion = true;
3339 else
3340 emit_move_insn (MEM_P (parmreg) ? copy_rtx (parmreg) : parmreg, rtl);
3342 rtl = parmreg;
3344 /* STACK_PARM is the pointer, not the parm, and PARMREG is
3345 now the parm. */
3346 data->stack_parm = NULL;
3349 set_parm_rtl (parm, rtl);
3351 /* Mark the register as eliminable if we did no conversion and it was
3352 copied from memory at a fixed offset, and the arg pointer was not
3353 copied to a pseudo-reg. If the arg pointer is a pseudo reg or the
3354 offset formed an invalid address, such memory-equivalences as we
3355 make here would screw up life analysis for it. */
3356 if (data->nominal_mode == data->passed_mode
3357 && !did_conversion
3358 && data->stack_parm != 0
3359 && MEM_P (data->stack_parm)
3360 && data->locate.offset.var == 0
3361 && reg_mentioned_p (virtual_incoming_args_rtx,
3362 XEXP (data->stack_parm, 0)))
3364 rtx_insn *linsn = get_last_insn ();
3365 rtx_insn *sinsn;
3366 rtx set;
3368 /* Mark complex types separately. */
3369 if (GET_CODE (parmreg) == CONCAT)
3371 scalar_mode submode = GET_MODE_INNER (GET_MODE (parmreg));
3372 int regnor = REGNO (XEXP (parmreg, 0));
3373 int regnoi = REGNO (XEXP (parmreg, 1));
3374 rtx stackr = adjust_address_nv (data->stack_parm, submode, 0);
3375 rtx stacki = adjust_address_nv (data->stack_parm, submode,
3376 GET_MODE_SIZE (submode));
3378 /* Scan backwards for the set of the real and
3379 imaginary parts. */
3380 for (sinsn = linsn; sinsn != 0;
3381 sinsn = prev_nonnote_insn (sinsn))
3383 set = single_set (sinsn);
3384 if (set == 0)
3385 continue;
3387 if (SET_DEST (set) == regno_reg_rtx [regnoi])
3388 set_unique_reg_note (sinsn, REG_EQUIV, stacki);
3389 else if (SET_DEST (set) == regno_reg_rtx [regnor])
3390 set_unique_reg_note (sinsn, REG_EQUIV, stackr);
3393 else
3394 set_dst_reg_note (linsn, REG_EQUIV, equiv_stack_parm, parmreg);
3397 /* For pointer data type, suggest pointer register. */
3398 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3399 mark_reg_pointer (parmreg,
3400 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
3403 /* A subroutine of assign_parms. Allocate stack space to hold the current
3404 parameter. Get it there. Perform all ABI specified conversions. */
3406 static void
3407 assign_parm_setup_stack (struct assign_parm_data_all *all, tree parm,
3408 struct assign_parm_data_one *data)
3410 /* Value must be stored in the stack slot STACK_PARM during function
3411 execution. */
3412 bool to_conversion = false;
3414 assign_parm_remove_parallels (data);
3416 if (data->promoted_mode != data->nominal_mode)
3418 /* Conversion is required. */
3419 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
3421 emit_move_insn (tempreg, validize_mem (copy_rtx (data->entry_parm)));
3423 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3424 to_conversion = true;
3426 data->entry_parm = convert_to_mode (data->nominal_mode, tempreg,
3427 TYPE_UNSIGNED (TREE_TYPE (parm)));
3429 if (data->stack_parm)
3431 poly_int64 offset
3432 = subreg_lowpart_offset (data->nominal_mode,
3433 GET_MODE (data->stack_parm));
3434 /* ??? This may need a big-endian conversion on sparc64. */
3435 data->stack_parm
3436 = adjust_address (data->stack_parm, data->nominal_mode, 0);
3437 if (maybe_ne (offset, 0) && MEM_OFFSET_KNOWN_P (data->stack_parm))
3438 set_mem_offset (data->stack_parm,
3439 MEM_OFFSET (data->stack_parm) + offset);
3443 if (data->entry_parm != data->stack_parm)
3445 rtx src, dest;
3447 if (data->stack_parm == 0)
3449 int align = STACK_SLOT_ALIGNMENT (data->passed_type,
3450 GET_MODE (data->entry_parm),
3451 TYPE_ALIGN (data->passed_type));
3452 data->stack_parm
3453 = assign_stack_local (GET_MODE (data->entry_parm),
3454 GET_MODE_SIZE (GET_MODE (data->entry_parm)),
3455 align);
3456 set_mem_attributes (data->stack_parm, parm, 1);
3459 dest = validize_mem (copy_rtx (data->stack_parm));
3460 src = validize_mem (copy_rtx (data->entry_parm));
3462 if (MEM_P (src))
3464 /* Use a block move to handle potentially misaligned entry_parm. */
3465 if (!to_conversion)
3466 push_to_sequence2 (all->first_conversion_insn,
3467 all->last_conversion_insn);
3468 to_conversion = true;
3470 emit_block_move (dest, src,
3471 GEN_INT (int_size_in_bytes (data->passed_type)),
3472 BLOCK_OP_NORMAL);
3474 else
3476 if (!REG_P (src))
3477 src = force_reg (GET_MODE (src), src);
3478 emit_move_insn (dest, src);
3482 if (to_conversion)
3484 all->first_conversion_insn = get_insns ();
3485 all->last_conversion_insn = get_last_insn ();
3486 end_sequence ();
3489 set_parm_rtl (parm, data->stack_parm);
3492 /* A subroutine of assign_parms. If the ABI splits complex arguments, then
3493 undo the frobbing that we did in assign_parms_augmented_arg_list. */
3495 static void
3496 assign_parms_unsplit_complex (struct assign_parm_data_all *all,
3497 vec<tree> fnargs)
3499 tree parm;
3500 tree orig_fnargs = all->orig_fnargs;
3501 unsigned i = 0;
3503 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm), ++i)
3505 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
3506 && targetm.calls.split_complex_arg (TREE_TYPE (parm)))
3508 rtx tmp, real, imag;
3509 scalar_mode inner = GET_MODE_INNER (DECL_MODE (parm));
3511 real = DECL_RTL (fnargs[i]);
3512 imag = DECL_RTL (fnargs[i + 1]);
3513 if (inner != GET_MODE (real))
3515 real = gen_lowpart_SUBREG (inner, real);
3516 imag = gen_lowpart_SUBREG (inner, imag);
3519 if (TREE_ADDRESSABLE (parm))
3521 rtx rmem, imem;
3522 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (parm));
3523 int align = STACK_SLOT_ALIGNMENT (TREE_TYPE (parm),
3524 DECL_MODE (parm),
3525 TYPE_ALIGN (TREE_TYPE (parm)));
3527 /* split_complex_arg put the real and imag parts in
3528 pseudos. Move them to memory. */
3529 tmp = assign_stack_local (DECL_MODE (parm), size, align);
3530 set_mem_attributes (tmp, parm, 1);
3531 rmem = adjust_address_nv (tmp, inner, 0);
3532 imem = adjust_address_nv (tmp, inner, GET_MODE_SIZE (inner));
3533 push_to_sequence2 (all->first_conversion_insn,
3534 all->last_conversion_insn);
3535 emit_move_insn (rmem, real);
3536 emit_move_insn (imem, imag);
3537 all->first_conversion_insn = get_insns ();
3538 all->last_conversion_insn = get_last_insn ();
3539 end_sequence ();
3541 else
3542 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
3543 set_parm_rtl (parm, tmp);
3545 real = DECL_INCOMING_RTL (fnargs[i]);
3546 imag = DECL_INCOMING_RTL (fnargs[i + 1]);
3547 if (inner != GET_MODE (real))
3549 real = gen_lowpart_SUBREG (inner, real);
3550 imag = gen_lowpart_SUBREG (inner, imag);
3552 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
3553 set_decl_incoming_rtl (parm, tmp, false);
3554 i++;
3559 /* Assign RTL expressions to the function's parameters. This may involve
3560 copying them into registers and using those registers as the DECL_RTL. */
3562 static void
3563 assign_parms (tree fndecl)
3565 struct assign_parm_data_all all;
3566 tree parm;
3567 vec<tree> fnargs;
3568 unsigned i;
3570 crtl->args.internal_arg_pointer
3571 = targetm.calls.internal_arg_pointer ();
3573 assign_parms_initialize_all (&all);
3574 fnargs = assign_parms_augmented_arg_list (&all);
3576 FOR_EACH_VEC_ELT (fnargs, i, parm)
3578 struct assign_parm_data_one data;
3580 /* Extract the type of PARM; adjust it according to ABI. */
3581 assign_parm_find_data_types (&all, parm, &data);
3583 /* Early out for errors and void parameters. */
3584 if (data.passed_mode == VOIDmode)
3586 SET_DECL_RTL (parm, const0_rtx);
3587 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
3588 continue;
3591 /* Estimate stack alignment from parameter alignment. */
3592 if (SUPPORTS_STACK_ALIGNMENT)
3594 unsigned int align
3595 = targetm.calls.function_arg_boundary (data.promoted_mode,
3596 data.passed_type);
3597 align = MINIMUM_ALIGNMENT (data.passed_type, data.promoted_mode,
3598 align);
3599 if (TYPE_ALIGN (data.nominal_type) > align)
3600 align = MINIMUM_ALIGNMENT (data.nominal_type,
3601 TYPE_MODE (data.nominal_type),
3602 TYPE_ALIGN (data.nominal_type));
3603 if (crtl->stack_alignment_estimated < align)
3605 gcc_assert (!crtl->stack_realign_processed);
3606 crtl->stack_alignment_estimated = align;
3610 /* Find out where the parameter arrives in this function. */
3611 assign_parm_find_entry_rtl (&all, &data);
3613 /* Find out where stack space for this parameter might be. */
3614 if (assign_parm_is_stack_parm (&all, &data))
3616 assign_parm_find_stack_rtl (parm, &data);
3617 assign_parm_adjust_entry_rtl (&data);
3619 /* Record permanently how this parm was passed. */
3620 if (data.passed_pointer)
3622 rtx incoming_rtl
3623 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data.passed_type)),
3624 data.entry_parm);
3625 set_decl_incoming_rtl (parm, incoming_rtl, true);
3627 else
3628 set_decl_incoming_rtl (parm, data.entry_parm, false);
3630 assign_parm_adjust_stack_rtl (&data);
3632 if (assign_parm_setup_block_p (&data))
3633 assign_parm_setup_block (&all, parm, &data);
3634 else if (data.passed_pointer || use_register_for_decl (parm))
3635 assign_parm_setup_reg (&all, parm, &data);
3636 else
3637 assign_parm_setup_stack (&all, parm, &data);
3639 if (cfun->stdarg && !DECL_CHAIN (parm))
3640 assign_parms_setup_varargs (&all, &data, false);
3642 /* Update info on where next arg arrives in registers. */
3643 targetm.calls.function_arg_advance (all.args_so_far, data.promoted_mode,
3644 data.passed_type, data.named_arg);
3647 if (targetm.calls.split_complex_arg)
3648 assign_parms_unsplit_complex (&all, fnargs);
3650 fnargs.release ();
3652 /* Output all parameter conversion instructions (possibly including calls)
3653 now that all parameters have been copied out of hard registers. */
3654 emit_insn (all.first_conversion_insn);
3656 /* Estimate reload stack alignment from scalar return mode. */
3657 if (SUPPORTS_STACK_ALIGNMENT)
3659 if (DECL_RESULT (fndecl))
3661 tree type = TREE_TYPE (DECL_RESULT (fndecl));
3662 machine_mode mode = TYPE_MODE (type);
3664 if (mode != BLKmode
3665 && mode != VOIDmode
3666 && !AGGREGATE_TYPE_P (type))
3668 unsigned int align = GET_MODE_ALIGNMENT (mode);
3669 if (crtl->stack_alignment_estimated < align)
3671 gcc_assert (!crtl->stack_realign_processed);
3672 crtl->stack_alignment_estimated = align;
3678 /* If we are receiving a struct value address as the first argument, set up
3679 the RTL for the function result. As this might require code to convert
3680 the transmitted address to Pmode, we do this here to ensure that possible
3681 preliminary conversions of the address have been emitted already. */
3682 if (all.function_result_decl)
3684 tree result = DECL_RESULT (current_function_decl);
3685 rtx addr = DECL_RTL (all.function_result_decl);
3686 rtx x;
3688 if (DECL_BY_REFERENCE (result))
3690 SET_DECL_VALUE_EXPR (result, all.function_result_decl);
3691 x = addr;
3693 else
3695 SET_DECL_VALUE_EXPR (result,
3696 build1 (INDIRECT_REF, TREE_TYPE (result),
3697 all.function_result_decl));
3698 addr = convert_memory_address (Pmode, addr);
3699 x = gen_rtx_MEM (DECL_MODE (result), addr);
3700 set_mem_attributes (x, result, 1);
3703 DECL_HAS_VALUE_EXPR_P (result) = 1;
3705 set_parm_rtl (result, x);
3708 /* We have aligned all the args, so add space for the pretend args. */
3709 crtl->args.pretend_args_size = all.pretend_args_size;
3710 all.stack_args_size.constant += all.extra_pretend_bytes;
3711 crtl->args.size = all.stack_args_size.constant;
3713 /* Adjust function incoming argument size for alignment and
3714 minimum length. */
3716 crtl->args.size = upper_bound (crtl->args.size, all.reg_parm_stack_space);
3717 crtl->args.size = aligned_upper_bound (crtl->args.size,
3718 PARM_BOUNDARY / BITS_PER_UNIT);
3720 if (ARGS_GROW_DOWNWARD)
3722 crtl->args.arg_offset_rtx
3723 = (all.stack_args_size.var == 0
3724 ? gen_int_mode (-all.stack_args_size.constant, Pmode)
3725 : expand_expr (size_diffop (all.stack_args_size.var,
3726 size_int (-all.stack_args_size.constant)),
3727 NULL_RTX, VOIDmode, EXPAND_NORMAL));
3729 else
3730 crtl->args.arg_offset_rtx = ARGS_SIZE_RTX (all.stack_args_size);
3732 /* See how many bytes, if any, of its args a function should try to pop
3733 on return. */
3735 crtl->args.pops_args = targetm.calls.return_pops_args (fndecl,
3736 TREE_TYPE (fndecl),
3737 crtl->args.size);
3739 /* For stdarg.h function, save info about
3740 regs and stack space used by the named args. */
3742 crtl->args.info = all.args_so_far_v;
3744 /* Set the rtx used for the function return value. Put this in its
3745 own variable so any optimizers that need this information don't have
3746 to include tree.h. Do this here so it gets done when an inlined
3747 function gets output. */
3749 crtl->return_rtx
3750 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
3751 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
3753 /* If scalar return value was computed in a pseudo-reg, or was a named
3754 return value that got dumped to the stack, copy that to the hard
3755 return register. */
3756 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
3758 tree decl_result = DECL_RESULT (fndecl);
3759 rtx decl_rtl = DECL_RTL (decl_result);
3761 if (REG_P (decl_rtl)
3762 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
3763 : DECL_REGISTER (decl_result))
3765 rtx real_decl_rtl;
3767 real_decl_rtl = targetm.calls.function_value (TREE_TYPE (decl_result),
3768 fndecl, true);
3769 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
3770 /* The delay slot scheduler assumes that crtl->return_rtx
3771 holds the hard register containing the return value, not a
3772 temporary pseudo. */
3773 crtl->return_rtx = real_decl_rtl;
3778 /* A subroutine of gimplify_parameters, invoked via walk_tree.
3779 For all seen types, gimplify their sizes. */
3781 static tree
3782 gimplify_parm_type (tree *tp, int *walk_subtrees, void *data)
3784 tree t = *tp;
3786 *walk_subtrees = 0;
3787 if (TYPE_P (t))
3789 if (POINTER_TYPE_P (t))
3790 *walk_subtrees = 1;
3791 else if (TYPE_SIZE (t) && !TREE_CONSTANT (TYPE_SIZE (t))
3792 && !TYPE_SIZES_GIMPLIFIED (t))
3794 gimplify_type_sizes (t, (gimple_seq *) data);
3795 *walk_subtrees = 1;
3799 return NULL;
3802 /* Gimplify the parameter list for current_function_decl. This involves
3803 evaluating SAVE_EXPRs of variable sized parameters and generating code
3804 to implement callee-copies reference parameters. Returns a sequence of
3805 statements to add to the beginning of the function. */
3807 gimple_seq
3808 gimplify_parameters (gimple_seq *cleanup)
3810 struct assign_parm_data_all all;
3811 tree parm;
3812 gimple_seq stmts = NULL;
3813 vec<tree> fnargs;
3814 unsigned i;
3816 assign_parms_initialize_all (&all);
3817 fnargs = assign_parms_augmented_arg_list (&all);
3819 FOR_EACH_VEC_ELT (fnargs, i, parm)
3821 struct assign_parm_data_one data;
3823 /* Extract the type of PARM; adjust it according to ABI. */
3824 assign_parm_find_data_types (&all, parm, &data);
3826 /* Early out for errors and void parameters. */
3827 if (data.passed_mode == VOIDmode || DECL_SIZE (parm) == NULL)
3828 continue;
3830 /* Update info on where next arg arrives in registers. */
3831 targetm.calls.function_arg_advance (all.args_so_far, data.promoted_mode,
3832 data.passed_type, data.named_arg);
3834 /* ??? Once upon a time variable_size stuffed parameter list
3835 SAVE_EXPRs (amongst others) onto a pending sizes list. This
3836 turned out to be less than manageable in the gimple world.
3837 Now we have to hunt them down ourselves. */
3838 walk_tree_without_duplicates (&data.passed_type,
3839 gimplify_parm_type, &stmts);
3841 if (TREE_CODE (DECL_SIZE_UNIT (parm)) != INTEGER_CST)
3843 gimplify_one_sizepos (&DECL_SIZE (parm), &stmts);
3844 gimplify_one_sizepos (&DECL_SIZE_UNIT (parm), &stmts);
3847 if (data.passed_pointer)
3849 tree type = TREE_TYPE (data.passed_type);
3850 if (reference_callee_copied (&all.args_so_far_v, TYPE_MODE (type),
3851 type, data.named_arg))
3853 tree local, t;
3855 /* For constant-sized objects, this is trivial; for
3856 variable-sized objects, we have to play games. */
3857 if (TREE_CODE (DECL_SIZE_UNIT (parm)) == INTEGER_CST
3858 && !(flag_stack_check == GENERIC_STACK_CHECK
3859 && compare_tree_int (DECL_SIZE_UNIT (parm),
3860 STACK_CHECK_MAX_VAR_SIZE) > 0))
3862 local = create_tmp_var (type, get_name (parm));
3863 DECL_IGNORED_P (local) = 0;
3864 /* If PARM was addressable, move that flag over
3865 to the local copy, as its address will be taken,
3866 not the PARMs. Keep the parms address taken
3867 as we'll query that flag during gimplification. */
3868 if (TREE_ADDRESSABLE (parm))
3869 TREE_ADDRESSABLE (local) = 1;
3870 else if (TREE_CODE (type) == COMPLEX_TYPE
3871 || TREE_CODE (type) == VECTOR_TYPE)
3872 DECL_GIMPLE_REG_P (local) = 1;
3874 if (!is_gimple_reg (local)
3875 && flag_stack_reuse != SR_NONE)
3877 tree clobber = build_constructor (type, NULL);
3878 gimple *clobber_stmt;
3879 TREE_THIS_VOLATILE (clobber) = 1;
3880 clobber_stmt = gimple_build_assign (local, clobber);
3881 gimple_seq_add_stmt (cleanup, clobber_stmt);
3884 else
3886 tree ptr_type, addr;
3888 ptr_type = build_pointer_type (type);
3889 addr = create_tmp_reg (ptr_type, get_name (parm));
3890 DECL_IGNORED_P (addr) = 0;
3891 local = build_fold_indirect_ref (addr);
3893 t = build_alloca_call_expr (DECL_SIZE_UNIT (parm),
3894 DECL_ALIGN (parm),
3895 max_int_size_in_bytes (type));
3896 /* The call has been built for a variable-sized object. */
3897 CALL_ALLOCA_FOR_VAR_P (t) = 1;
3898 t = fold_convert (ptr_type, t);
3899 t = build2 (MODIFY_EXPR, TREE_TYPE (addr), addr, t);
3900 gimplify_and_add (t, &stmts);
3903 gimplify_assign (local, parm, &stmts);
3905 SET_DECL_VALUE_EXPR (parm, local);
3906 DECL_HAS_VALUE_EXPR_P (parm) = 1;
3911 fnargs.release ();
3913 return stmts;
3916 /* Compute the size and offset from the start of the stacked arguments for a
3917 parm passed in mode PASSED_MODE and with type TYPE.
3919 INITIAL_OFFSET_PTR points to the current offset into the stacked
3920 arguments.
3922 The starting offset and size for this parm are returned in
3923 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
3924 nonzero, the offset is that of stack slot, which is returned in
3925 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
3926 padding required from the initial offset ptr to the stack slot.
3928 IN_REGS is nonzero if the argument will be passed in registers. It will
3929 never be set if REG_PARM_STACK_SPACE is not defined.
3931 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
3932 for arguments which are passed in registers.
3934 FNDECL is the function in which the argument was defined.
3936 There are two types of rounding that are done. The first, controlled by
3937 TARGET_FUNCTION_ARG_BOUNDARY, forces the offset from the start of the
3938 argument list to be aligned to the specific boundary (in bits). This
3939 rounding affects the initial and starting offsets, but not the argument
3940 size.
3942 The second, controlled by TARGET_FUNCTION_ARG_PADDING and PARM_BOUNDARY,
3943 optionally rounds the size of the parm to PARM_BOUNDARY. The
3944 initial offset is not affected by this rounding, while the size always
3945 is and the starting offset may be. */
3947 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
3948 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
3949 callers pass in the total size of args so far as
3950 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
3952 void
3953 locate_and_pad_parm (machine_mode passed_mode, tree type, int in_regs,
3954 int reg_parm_stack_space, int partial,
3955 tree fndecl ATTRIBUTE_UNUSED,
3956 struct args_size *initial_offset_ptr,
3957 struct locate_and_pad_arg_data *locate)
3959 tree sizetree;
3960 pad_direction where_pad;
3961 unsigned int boundary, round_boundary;
3962 int part_size_in_regs;
3964 /* If we have found a stack parm before we reach the end of the
3965 area reserved for registers, skip that area. */
3966 if (! in_regs)
3968 if (reg_parm_stack_space > 0)
3970 if (initial_offset_ptr->var
3971 || !ordered_p (initial_offset_ptr->constant,
3972 reg_parm_stack_space))
3974 initial_offset_ptr->var
3975 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
3976 ssize_int (reg_parm_stack_space));
3977 initial_offset_ptr->constant = 0;
3979 else
3980 initial_offset_ptr->constant
3981 = ordered_max (initial_offset_ptr->constant,
3982 reg_parm_stack_space);
3986 part_size_in_regs = (reg_parm_stack_space == 0 ? partial : 0);
3988 sizetree = (type
3989 ? arg_size_in_bytes (type)
3990 : size_int (GET_MODE_SIZE (passed_mode)));
3991 where_pad = targetm.calls.function_arg_padding (passed_mode, type);
3992 boundary = targetm.calls.function_arg_boundary (passed_mode, type);
3993 round_boundary = targetm.calls.function_arg_round_boundary (passed_mode,
3994 type);
3995 locate->where_pad = where_pad;
3997 /* Alignment can't exceed MAX_SUPPORTED_STACK_ALIGNMENT. */
3998 if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
3999 boundary = MAX_SUPPORTED_STACK_ALIGNMENT;
4001 locate->boundary = boundary;
4003 if (SUPPORTS_STACK_ALIGNMENT)
4005 /* stack_alignment_estimated can't change after stack has been
4006 realigned. */
4007 if (crtl->stack_alignment_estimated < boundary)
4009 if (!crtl->stack_realign_processed)
4010 crtl->stack_alignment_estimated = boundary;
4011 else
4013 /* If stack is realigned and stack alignment value
4014 hasn't been finalized, it is OK not to increase
4015 stack_alignment_estimated. The bigger alignment
4016 requirement is recorded in stack_alignment_needed
4017 below. */
4018 gcc_assert (!crtl->stack_realign_finalized
4019 && crtl->stack_realign_needed);
4024 if (ARGS_GROW_DOWNWARD)
4026 locate->slot_offset.constant = -initial_offset_ptr->constant;
4027 if (initial_offset_ptr->var)
4028 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
4029 initial_offset_ptr->var);
4032 tree s2 = sizetree;
4033 if (where_pad != PAD_NONE
4034 && (!tree_fits_uhwi_p (sizetree)
4035 || (tree_to_uhwi (sizetree) * BITS_PER_UNIT) % round_boundary))
4036 s2 = round_up (s2, round_boundary / BITS_PER_UNIT);
4037 SUB_PARM_SIZE (locate->slot_offset, s2);
4040 locate->slot_offset.constant += part_size_in_regs;
4042 if (!in_regs || reg_parm_stack_space > 0)
4043 pad_to_arg_alignment (&locate->slot_offset, boundary,
4044 &locate->alignment_pad);
4046 locate->size.constant = (-initial_offset_ptr->constant
4047 - locate->slot_offset.constant);
4048 if (initial_offset_ptr->var)
4049 locate->size.var = size_binop (MINUS_EXPR,
4050 size_binop (MINUS_EXPR,
4051 ssize_int (0),
4052 initial_offset_ptr->var),
4053 locate->slot_offset.var);
4055 /* Pad_below needs the pre-rounded size to know how much to pad
4056 below. */
4057 locate->offset = locate->slot_offset;
4058 if (where_pad == PAD_DOWNWARD)
4059 pad_below (&locate->offset, passed_mode, sizetree);
4062 else
4064 if (!in_regs || reg_parm_stack_space > 0)
4065 pad_to_arg_alignment (initial_offset_ptr, boundary,
4066 &locate->alignment_pad);
4067 locate->slot_offset = *initial_offset_ptr;
4069 #ifdef PUSH_ROUNDING
4070 if (passed_mode != BLKmode)
4071 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
4072 #endif
4074 /* Pad_below needs the pre-rounded size to know how much to pad below
4075 so this must be done before rounding up. */
4076 locate->offset = locate->slot_offset;
4077 if (where_pad == PAD_DOWNWARD)
4078 pad_below (&locate->offset, passed_mode, sizetree);
4080 if (where_pad != PAD_NONE
4081 && (!tree_fits_uhwi_p (sizetree)
4082 || (tree_to_uhwi (sizetree) * BITS_PER_UNIT) % round_boundary))
4083 sizetree = round_up (sizetree, round_boundary / BITS_PER_UNIT);
4085 ADD_PARM_SIZE (locate->size, sizetree);
4087 locate->size.constant -= part_size_in_regs;
4090 locate->offset.constant
4091 += targetm.calls.function_arg_offset (passed_mode, type);
4094 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
4095 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
4097 static void
4098 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
4099 struct args_size *alignment_pad)
4101 tree save_var = NULL_TREE;
4102 poly_int64 save_constant = 0;
4103 int boundary_in_bytes = boundary / BITS_PER_UNIT;
4104 poly_int64 sp_offset = STACK_POINTER_OFFSET;
4106 #ifdef SPARC_STACK_BOUNDARY_HACK
4107 /* ??? The SPARC port may claim a STACK_BOUNDARY higher than
4108 the real alignment of %sp. However, when it does this, the
4109 alignment of %sp+STACK_POINTER_OFFSET is STACK_BOUNDARY. */
4110 if (SPARC_STACK_BOUNDARY_HACK)
4111 sp_offset = 0;
4112 #endif
4114 if (boundary > PARM_BOUNDARY)
4116 save_var = offset_ptr->var;
4117 save_constant = offset_ptr->constant;
4120 alignment_pad->var = NULL_TREE;
4121 alignment_pad->constant = 0;
4123 if (boundary > BITS_PER_UNIT)
4125 int misalign;
4126 if (offset_ptr->var
4127 || !known_misalignment (offset_ptr->constant + sp_offset,
4128 boundary_in_bytes, &misalign))
4130 tree sp_offset_tree = ssize_int (sp_offset);
4131 tree offset = size_binop (PLUS_EXPR,
4132 ARGS_SIZE_TREE (*offset_ptr),
4133 sp_offset_tree);
4134 tree rounded;
4135 if (ARGS_GROW_DOWNWARD)
4136 rounded = round_down (offset, boundary / BITS_PER_UNIT);
4137 else
4138 rounded = round_up (offset, boundary / BITS_PER_UNIT);
4140 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
4141 /* ARGS_SIZE_TREE includes constant term. */
4142 offset_ptr->constant = 0;
4143 if (boundary > PARM_BOUNDARY)
4144 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
4145 save_var);
4147 else
4149 if (ARGS_GROW_DOWNWARD)
4150 offset_ptr->constant -= misalign;
4151 else
4152 offset_ptr->constant += -misalign & (boundary_in_bytes - 1);
4154 if (boundary > PARM_BOUNDARY)
4155 alignment_pad->constant = offset_ptr->constant - save_constant;
4160 static void
4161 pad_below (struct args_size *offset_ptr, machine_mode passed_mode, tree sizetree)
4163 unsigned int align = PARM_BOUNDARY / BITS_PER_UNIT;
4164 int misalign;
4165 if (passed_mode != BLKmode
4166 && known_misalignment (GET_MODE_SIZE (passed_mode), align, &misalign))
4167 offset_ptr->constant += -misalign & (align - 1);
4168 else
4170 if (TREE_CODE (sizetree) != INTEGER_CST
4171 || (TREE_INT_CST_LOW (sizetree) & (align - 1)) != 0)
4173 /* Round the size up to multiple of PARM_BOUNDARY bits. */
4174 tree s2 = round_up (sizetree, align);
4175 /* Add it in. */
4176 ADD_PARM_SIZE (*offset_ptr, s2);
4177 SUB_PARM_SIZE (*offset_ptr, sizetree);
4183 /* True if register REGNO was alive at a place where `setjmp' was
4184 called and was set more than once or is an argument. Such regs may
4185 be clobbered by `longjmp'. */
4187 static bool
4188 regno_clobbered_at_setjmp (bitmap setjmp_crosses, int regno)
4190 /* There appear to be cases where some local vars never reach the
4191 backend but have bogus regnos. */
4192 if (regno >= max_reg_num ())
4193 return false;
4195 return ((REG_N_SETS (regno) > 1
4196 || REGNO_REG_SET_P (df_get_live_out (ENTRY_BLOCK_PTR_FOR_FN (cfun)),
4197 regno))
4198 && REGNO_REG_SET_P (setjmp_crosses, regno));
4201 /* Walk the tree of blocks describing the binding levels within a
4202 function and warn about variables the might be killed by setjmp or
4203 vfork. This is done after calling flow_analysis before register
4204 allocation since that will clobber the pseudo-regs to hard
4205 regs. */
4207 static void
4208 setjmp_vars_warning (bitmap setjmp_crosses, tree block)
4210 tree decl, sub;
4212 for (decl = BLOCK_VARS (block); decl; decl = DECL_CHAIN (decl))
4214 if (VAR_P (decl)
4215 && DECL_RTL_SET_P (decl)
4216 && REG_P (DECL_RTL (decl))
4217 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
4218 warning (OPT_Wclobbered, "variable %q+D might be clobbered by"
4219 " %<longjmp%> or %<vfork%>", decl);
4222 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = BLOCK_CHAIN (sub))
4223 setjmp_vars_warning (setjmp_crosses, sub);
4226 /* Do the appropriate part of setjmp_vars_warning
4227 but for arguments instead of local variables. */
4229 static void
4230 setjmp_args_warning (bitmap setjmp_crosses)
4232 tree decl;
4233 for (decl = DECL_ARGUMENTS (current_function_decl);
4234 decl; decl = DECL_CHAIN (decl))
4235 if (DECL_RTL (decl) != 0
4236 && REG_P (DECL_RTL (decl))
4237 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
4238 warning (OPT_Wclobbered,
4239 "argument %q+D might be clobbered by %<longjmp%> or %<vfork%>",
4240 decl);
4243 /* Generate warning messages for variables live across setjmp. */
4245 void
4246 generate_setjmp_warnings (void)
4248 bitmap setjmp_crosses = regstat_get_setjmp_crosses ();
4250 if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS
4251 || bitmap_empty_p (setjmp_crosses))
4252 return;
4254 setjmp_vars_warning (setjmp_crosses, DECL_INITIAL (current_function_decl));
4255 setjmp_args_warning (setjmp_crosses);
4259 /* Reverse the order of elements in the fragment chain T of blocks,
4260 and return the new head of the chain (old last element).
4261 In addition to that clear BLOCK_SAME_RANGE flags when needed
4262 and adjust BLOCK_SUPERCONTEXT from the super fragment to
4263 its super fragment origin. */
4265 static tree
4266 block_fragments_nreverse (tree t)
4268 tree prev = 0, block, next, prev_super = 0;
4269 tree super = BLOCK_SUPERCONTEXT (t);
4270 if (BLOCK_FRAGMENT_ORIGIN (super))
4271 super = BLOCK_FRAGMENT_ORIGIN (super);
4272 for (block = t; block; block = next)
4274 next = BLOCK_FRAGMENT_CHAIN (block);
4275 BLOCK_FRAGMENT_CHAIN (block) = prev;
4276 if ((prev && !BLOCK_SAME_RANGE (prev))
4277 || (BLOCK_FRAGMENT_CHAIN (BLOCK_SUPERCONTEXT (block))
4278 != prev_super))
4279 BLOCK_SAME_RANGE (block) = 0;
4280 prev_super = BLOCK_SUPERCONTEXT (block);
4281 BLOCK_SUPERCONTEXT (block) = super;
4282 prev = block;
4284 t = BLOCK_FRAGMENT_ORIGIN (t);
4285 if (BLOCK_FRAGMENT_CHAIN (BLOCK_SUPERCONTEXT (t))
4286 != prev_super)
4287 BLOCK_SAME_RANGE (t) = 0;
4288 BLOCK_SUPERCONTEXT (t) = super;
4289 return prev;
4292 /* Reverse the order of elements in the chain T of blocks,
4293 and return the new head of the chain (old last element).
4294 Also do the same on subblocks and reverse the order of elements
4295 in BLOCK_FRAGMENT_CHAIN as well. */
4297 static tree
4298 blocks_nreverse_all (tree t)
4300 tree prev = 0, block, next;
4301 for (block = t; block; block = next)
4303 next = BLOCK_CHAIN (block);
4304 BLOCK_CHAIN (block) = prev;
4305 if (BLOCK_FRAGMENT_CHAIN (block)
4306 && BLOCK_FRAGMENT_ORIGIN (block) == NULL_TREE)
4308 BLOCK_FRAGMENT_CHAIN (block)
4309 = block_fragments_nreverse (BLOCK_FRAGMENT_CHAIN (block));
4310 if (!BLOCK_SAME_RANGE (BLOCK_FRAGMENT_CHAIN (block)))
4311 BLOCK_SAME_RANGE (block) = 0;
4313 BLOCK_SUBBLOCKS (block) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block));
4314 prev = block;
4316 return prev;
4320 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
4321 and create duplicate blocks. */
4322 /* ??? Need an option to either create block fragments or to create
4323 abstract origin duplicates of a source block. It really depends
4324 on what optimization has been performed. */
4326 void
4327 reorder_blocks (void)
4329 tree block = DECL_INITIAL (current_function_decl);
4331 if (block == NULL_TREE)
4332 return;
4334 auto_vec<tree, 10> block_stack;
4336 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
4337 clear_block_marks (block);
4339 /* Prune the old trees away, so that they don't get in the way. */
4340 BLOCK_SUBBLOCKS (block) = NULL_TREE;
4341 BLOCK_CHAIN (block) = NULL_TREE;
4343 /* Recreate the block tree from the note nesting. */
4344 reorder_blocks_1 (get_insns (), block, &block_stack);
4345 BLOCK_SUBBLOCKS (block) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block));
4348 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
4350 void
4351 clear_block_marks (tree block)
4353 while (block)
4355 TREE_ASM_WRITTEN (block) = 0;
4356 clear_block_marks (BLOCK_SUBBLOCKS (block));
4357 block = BLOCK_CHAIN (block);
4361 static void
4362 reorder_blocks_1 (rtx_insn *insns, tree current_block,
4363 vec<tree> *p_block_stack)
4365 rtx_insn *insn;
4366 tree prev_beg = NULL_TREE, prev_end = NULL_TREE;
4368 for (insn = insns; insn; insn = NEXT_INSN (insn))
4370 if (NOTE_P (insn))
4372 if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_BEG)
4374 tree block = NOTE_BLOCK (insn);
4375 tree origin;
4377 gcc_assert (BLOCK_FRAGMENT_ORIGIN (block) == NULL_TREE);
4378 origin = block;
4380 if (prev_end)
4381 BLOCK_SAME_RANGE (prev_end) = 0;
4382 prev_end = NULL_TREE;
4384 /* If we have seen this block before, that means it now
4385 spans multiple address regions. Create a new fragment. */
4386 if (TREE_ASM_WRITTEN (block))
4388 tree new_block = copy_node (block);
4390 BLOCK_SAME_RANGE (new_block) = 0;
4391 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
4392 BLOCK_FRAGMENT_CHAIN (new_block)
4393 = BLOCK_FRAGMENT_CHAIN (origin);
4394 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
4396 NOTE_BLOCK (insn) = new_block;
4397 block = new_block;
4400 if (prev_beg == current_block && prev_beg)
4401 BLOCK_SAME_RANGE (block) = 1;
4403 prev_beg = origin;
4405 BLOCK_SUBBLOCKS (block) = 0;
4406 TREE_ASM_WRITTEN (block) = 1;
4407 /* When there's only one block for the entire function,
4408 current_block == block and we mustn't do this, it
4409 will cause infinite recursion. */
4410 if (block != current_block)
4412 tree super;
4413 if (block != origin)
4414 gcc_assert (BLOCK_SUPERCONTEXT (origin) == current_block
4415 || BLOCK_FRAGMENT_ORIGIN (BLOCK_SUPERCONTEXT
4416 (origin))
4417 == current_block);
4418 if (p_block_stack->is_empty ())
4419 super = current_block;
4420 else
4422 super = p_block_stack->last ();
4423 gcc_assert (super == current_block
4424 || BLOCK_FRAGMENT_ORIGIN (super)
4425 == current_block);
4427 BLOCK_SUPERCONTEXT (block) = super;
4428 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
4429 BLOCK_SUBBLOCKS (current_block) = block;
4430 current_block = origin;
4432 p_block_stack->safe_push (block);
4434 else if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_END)
4436 NOTE_BLOCK (insn) = p_block_stack->pop ();
4437 current_block = BLOCK_SUPERCONTEXT (current_block);
4438 if (BLOCK_FRAGMENT_ORIGIN (current_block))
4439 current_block = BLOCK_FRAGMENT_ORIGIN (current_block);
4440 prev_beg = NULL_TREE;
4441 prev_end = BLOCK_SAME_RANGE (NOTE_BLOCK (insn))
4442 ? NOTE_BLOCK (insn) : NULL_TREE;
4445 else
4447 prev_beg = NULL_TREE;
4448 if (prev_end)
4449 BLOCK_SAME_RANGE (prev_end) = 0;
4450 prev_end = NULL_TREE;
4455 /* Reverse the order of elements in the chain T of blocks,
4456 and return the new head of the chain (old last element). */
4458 tree
4459 blocks_nreverse (tree t)
4461 tree prev = 0, block, next;
4462 for (block = t; block; block = next)
4464 next = BLOCK_CHAIN (block);
4465 BLOCK_CHAIN (block) = prev;
4466 prev = block;
4468 return prev;
4471 /* Concatenate two chains of blocks (chained through BLOCK_CHAIN)
4472 by modifying the last node in chain 1 to point to chain 2. */
4474 tree
4475 block_chainon (tree op1, tree op2)
4477 tree t1;
4479 if (!op1)
4480 return op2;
4481 if (!op2)
4482 return op1;
4484 for (t1 = op1; BLOCK_CHAIN (t1); t1 = BLOCK_CHAIN (t1))
4485 continue;
4486 BLOCK_CHAIN (t1) = op2;
4488 #ifdef ENABLE_TREE_CHECKING
4490 tree t2;
4491 for (t2 = op2; t2; t2 = BLOCK_CHAIN (t2))
4492 gcc_assert (t2 != t1);
4494 #endif
4496 return op1;
4499 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
4500 non-NULL, list them all into VECTOR, in a depth-first preorder
4501 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
4502 blocks. */
4504 static int
4505 all_blocks (tree block, tree *vector)
4507 int n_blocks = 0;
4509 while (block)
4511 TREE_ASM_WRITTEN (block) = 0;
4513 /* Record this block. */
4514 if (vector)
4515 vector[n_blocks] = block;
4517 ++n_blocks;
4519 /* Record the subblocks, and their subblocks... */
4520 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
4521 vector ? vector + n_blocks : 0);
4522 block = BLOCK_CHAIN (block);
4525 return n_blocks;
4528 /* Return a vector containing all the blocks rooted at BLOCK. The
4529 number of elements in the vector is stored in N_BLOCKS_P. The
4530 vector is dynamically allocated; it is the caller's responsibility
4531 to call `free' on the pointer returned. */
4533 static tree *
4534 get_block_vector (tree block, int *n_blocks_p)
4536 tree *block_vector;
4538 *n_blocks_p = all_blocks (block, NULL);
4539 block_vector = XNEWVEC (tree, *n_blocks_p);
4540 all_blocks (block, block_vector);
4542 return block_vector;
4545 static GTY(()) int next_block_index = 2;
4547 /* Set BLOCK_NUMBER for all the blocks in FN. */
4549 void
4550 number_blocks (tree fn)
4552 int i;
4553 int n_blocks;
4554 tree *block_vector;
4556 /* For XCOFF debugging output, we start numbering the blocks
4557 from 1 within each function, rather than keeping a running
4558 count. */
4559 #if defined (XCOFF_DEBUGGING_INFO)
4560 if (write_symbols == XCOFF_DEBUG)
4561 next_block_index = 1;
4562 #endif
4564 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
4566 /* The top-level BLOCK isn't numbered at all. */
4567 for (i = 1; i < n_blocks; ++i)
4568 /* We number the blocks from two. */
4569 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
4571 free (block_vector);
4573 return;
4576 /* If VAR is present in a subblock of BLOCK, return the subblock. */
4578 DEBUG_FUNCTION tree
4579 debug_find_var_in_block_tree (tree var, tree block)
4581 tree t;
4583 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
4584 if (t == var)
4585 return block;
4587 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
4589 tree ret = debug_find_var_in_block_tree (var, t);
4590 if (ret)
4591 return ret;
4594 return NULL_TREE;
4597 /* Keep track of whether we're in a dummy function context. If we are,
4598 we don't want to invoke the set_current_function hook, because we'll
4599 get into trouble if the hook calls target_reinit () recursively or
4600 when the initial initialization is not yet complete. */
4602 static bool in_dummy_function;
4604 /* Invoke the target hook when setting cfun. Update the optimization options
4605 if the function uses different options than the default. */
4607 static void
4608 invoke_set_current_function_hook (tree fndecl)
4610 if (!in_dummy_function)
4612 tree opts = ((fndecl)
4613 ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (fndecl)
4614 : optimization_default_node);
4616 if (!opts)
4617 opts = optimization_default_node;
4619 /* Change optimization options if needed. */
4620 if (optimization_current_node != opts)
4622 optimization_current_node = opts;
4623 cl_optimization_restore (&global_options, TREE_OPTIMIZATION (opts));
4626 targetm.set_current_function (fndecl);
4627 this_fn_optabs = this_target_optabs;
4629 /* Initialize global alignment variables after op. */
4630 parse_alignment_opts ();
4632 if (opts != optimization_default_node)
4634 init_tree_optimization_optabs (opts);
4635 if (TREE_OPTIMIZATION_OPTABS (opts))
4636 this_fn_optabs = (struct target_optabs *)
4637 TREE_OPTIMIZATION_OPTABS (opts);
4642 /* cfun should never be set directly; use this function. */
4644 void
4645 set_cfun (struct function *new_cfun, bool force)
4647 if (cfun != new_cfun || force)
4649 cfun = new_cfun;
4650 invoke_set_current_function_hook (new_cfun ? new_cfun->decl : NULL_TREE);
4651 redirect_edge_var_map_empty ();
4655 /* Initialized with NOGC, making this poisonous to the garbage collector. */
4657 static vec<function *> cfun_stack;
4659 /* Push the current cfun onto the stack, and set cfun to new_cfun. Also set
4660 current_function_decl accordingly. */
4662 void
4663 push_cfun (struct function *new_cfun)
4665 gcc_assert ((!cfun && !current_function_decl)
4666 || (cfun && current_function_decl == cfun->decl));
4667 cfun_stack.safe_push (cfun);
4668 current_function_decl = new_cfun ? new_cfun->decl : NULL_TREE;
4669 set_cfun (new_cfun);
4672 /* Pop cfun from the stack. Also set current_function_decl accordingly. */
4674 void
4675 pop_cfun (void)
4677 struct function *new_cfun = cfun_stack.pop ();
4678 /* When in_dummy_function, we do have a cfun but current_function_decl is
4679 NULL. We also allow pushing NULL cfun and subsequently changing
4680 current_function_decl to something else and have both restored by
4681 pop_cfun. */
4682 gcc_checking_assert (in_dummy_function
4683 || !cfun
4684 || current_function_decl == cfun->decl);
4685 set_cfun (new_cfun);
4686 current_function_decl = new_cfun ? new_cfun->decl : NULL_TREE;
4689 /* Return value of funcdef and increase it. */
4691 get_next_funcdef_no (void)
4693 return funcdef_no++;
4696 /* Return value of funcdef. */
4698 get_last_funcdef_no (void)
4700 return funcdef_no;
4703 /* Allocate a function structure for FNDECL and set its contents
4704 to the defaults. Set cfun to the newly-allocated object.
4705 Some of the helper functions invoked during initialization assume
4706 that cfun has already been set. Therefore, assign the new object
4707 directly into cfun and invoke the back end hook explicitly at the
4708 very end, rather than initializing a temporary and calling set_cfun
4709 on it.
4711 ABSTRACT_P is true if this is a function that will never be seen by
4712 the middle-end. Such functions are front-end concepts (like C++
4713 function templates) that do not correspond directly to functions
4714 placed in object files. */
4716 void
4717 allocate_struct_function (tree fndecl, bool abstract_p)
4719 tree fntype = fndecl ? TREE_TYPE (fndecl) : NULL_TREE;
4721 cfun = ggc_cleared_alloc<function> ();
4723 init_eh_for_function ();
4725 if (init_machine_status)
4726 cfun->machine = (*init_machine_status) ();
4728 #ifdef OVERRIDE_ABI_FORMAT
4729 OVERRIDE_ABI_FORMAT (fndecl);
4730 #endif
4732 if (fndecl != NULL_TREE)
4734 DECL_STRUCT_FUNCTION (fndecl) = cfun;
4735 cfun->decl = fndecl;
4736 current_function_funcdef_no = get_next_funcdef_no ();
4739 invoke_set_current_function_hook (fndecl);
4741 if (fndecl != NULL_TREE)
4743 tree result = DECL_RESULT (fndecl);
4745 if (!abstract_p)
4747 /* Now that we have activated any function-specific attributes
4748 that might affect layout, particularly vector modes, relayout
4749 each of the parameters and the result. */
4750 relayout_decl (result);
4751 for (tree parm = DECL_ARGUMENTS (fndecl); parm;
4752 parm = DECL_CHAIN (parm))
4753 relayout_decl (parm);
4755 /* Similarly relayout the function decl. */
4756 targetm.target_option.relayout_function (fndecl);
4759 if (!abstract_p && aggregate_value_p (result, fndecl))
4761 #ifdef PCC_STATIC_STRUCT_RETURN
4762 cfun->returns_pcc_struct = 1;
4763 #endif
4764 cfun->returns_struct = 1;
4767 cfun->stdarg = stdarg_p (fntype);
4769 /* Assume all registers in stdarg functions need to be saved. */
4770 cfun->va_list_gpr_size = VA_LIST_MAX_GPR_SIZE;
4771 cfun->va_list_fpr_size = VA_LIST_MAX_FPR_SIZE;
4773 /* ??? This could be set on a per-function basis by the front-end
4774 but is this worth the hassle? */
4775 cfun->can_throw_non_call_exceptions = flag_non_call_exceptions;
4776 cfun->can_delete_dead_exceptions = flag_delete_dead_exceptions;
4778 if (!profile_flag && !flag_instrument_function_entry_exit)
4779 DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl) = 1;
4782 /* Don't enable begin stmt markers if var-tracking at assignments is
4783 disabled. The markers make little sense without the variable
4784 binding annotations among them. */
4785 cfun->debug_nonbind_markers = lang_hooks.emits_begin_stmt
4786 && MAY_HAVE_DEBUG_MARKER_STMTS;
4789 /* This is like allocate_struct_function, but pushes a new cfun for FNDECL
4790 instead of just setting it. */
4792 void
4793 push_struct_function (tree fndecl)
4795 /* When in_dummy_function we might be in the middle of a pop_cfun and
4796 current_function_decl and cfun may not match. */
4797 gcc_assert (in_dummy_function
4798 || (!cfun && !current_function_decl)
4799 || (cfun && current_function_decl == cfun->decl));
4800 cfun_stack.safe_push (cfun);
4801 current_function_decl = fndecl;
4802 allocate_struct_function (fndecl, false);
4805 /* Reset crtl and other non-struct-function variables to defaults as
4806 appropriate for emitting rtl at the start of a function. */
4808 static void
4809 prepare_function_start (void)
4811 gcc_assert (!get_last_insn ());
4812 init_temp_slots ();
4813 init_emit ();
4814 init_varasm_status ();
4815 init_expr ();
4816 default_rtl_profile ();
4818 if (flag_stack_usage_info)
4820 cfun->su = ggc_cleared_alloc<stack_usage> ();
4821 cfun->su->static_stack_size = -1;
4824 cse_not_expected = ! optimize;
4826 /* Caller save not needed yet. */
4827 caller_save_needed = 0;
4829 /* We haven't done register allocation yet. */
4830 reg_renumber = 0;
4832 /* Indicate that we have not instantiated virtual registers yet. */
4833 virtuals_instantiated = 0;
4835 /* Indicate that we want CONCATs now. */
4836 generating_concat_p = 1;
4838 /* Indicate we have no need of a frame pointer yet. */
4839 frame_pointer_needed = 0;
4842 void
4843 push_dummy_function (bool with_decl)
4845 tree fn_decl, fn_type, fn_result_decl;
4847 gcc_assert (!in_dummy_function);
4848 in_dummy_function = true;
4850 if (with_decl)
4852 fn_type = build_function_type_list (void_type_node, NULL_TREE);
4853 fn_decl = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL, NULL_TREE,
4854 fn_type);
4855 fn_result_decl = build_decl (UNKNOWN_LOCATION, RESULT_DECL,
4856 NULL_TREE, void_type_node);
4857 DECL_RESULT (fn_decl) = fn_result_decl;
4859 else
4860 fn_decl = NULL_TREE;
4862 push_struct_function (fn_decl);
4865 /* Initialize the rtl expansion mechanism so that we can do simple things
4866 like generate sequences. This is used to provide a context during global
4867 initialization of some passes. You must call expand_dummy_function_end
4868 to exit this context. */
4870 void
4871 init_dummy_function_start (void)
4873 push_dummy_function (false);
4874 prepare_function_start ();
4877 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
4878 and initialize static variables for generating RTL for the statements
4879 of the function. */
4881 void
4882 init_function_start (tree subr)
4884 /* Initialize backend, if needed. */
4885 initialize_rtl ();
4887 prepare_function_start ();
4888 decide_function_section (subr);
4890 /* Warn if this value is an aggregate type,
4891 regardless of which calling convention we are using for it. */
4892 if (AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
4893 warning (OPT_Waggregate_return, "function returns an aggregate");
4896 /* Expand code to verify the stack_protect_guard. This is invoked at
4897 the end of a function to be protected. */
4899 void
4900 stack_protect_epilogue (void)
4902 tree guard_decl = crtl->stack_protect_guard_decl;
4903 rtx_code_label *label = gen_label_rtx ();
4904 rtx x, y;
4905 rtx_insn *seq = NULL;
4907 x = expand_normal (crtl->stack_protect_guard);
4909 if (targetm.have_stack_protect_combined_test () && guard_decl)
4911 gcc_assert (DECL_P (guard_decl));
4912 y = DECL_RTL (guard_decl);
4913 /* Allow the target to compute address of Y and compare it with X without
4914 leaking Y into a register. This combined address + compare pattern
4915 allows the target to prevent spilling of any intermediate results by
4916 splitting it after register allocator. */
4917 seq = targetm.gen_stack_protect_combined_test (x, y, label);
4919 else
4921 if (guard_decl)
4922 y = expand_normal (guard_decl);
4923 else
4924 y = const0_rtx;
4926 /* Allow the target to compare Y with X without leaking either into
4927 a register. */
4928 if (targetm.have_stack_protect_test ())
4929 seq = targetm.gen_stack_protect_test (x, y, label);
4932 if (seq)
4933 emit_insn (seq);
4934 else
4935 emit_cmp_and_jump_insns (x, y, EQ, NULL_RTX, ptr_mode, 1, label);
4937 /* The noreturn predictor has been moved to the tree level. The rtl-level
4938 predictors estimate this branch about 20%, which isn't enough to get
4939 things moved out of line. Since this is the only extant case of adding
4940 a noreturn function at the rtl level, it doesn't seem worth doing ought
4941 except adding the prediction by hand. */
4942 rtx_insn *tmp = get_last_insn ();
4943 if (JUMP_P (tmp))
4944 predict_insn_def (tmp, PRED_NORETURN, TAKEN);
4946 expand_call (targetm.stack_protect_fail (), NULL_RTX, /*ignore=*/true);
4947 free_temp_slots ();
4948 emit_label (label);
4951 /* Start the RTL for a new function, and set variables used for
4952 emitting RTL.
4953 SUBR is the FUNCTION_DECL node.
4954 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
4955 the function's parameters, which must be run at any return statement. */
4957 void
4958 expand_function_start (tree subr)
4960 /* Make sure volatile mem refs aren't considered
4961 valid operands of arithmetic insns. */
4962 init_recog_no_volatile ();
4964 crtl->profile
4965 = (profile_flag
4966 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
4968 crtl->limit_stack
4969 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
4971 /* Make the label for return statements to jump to. Do not special
4972 case machines with special return instructions -- they will be
4973 handled later during jump, ifcvt, or epilogue creation. */
4974 return_label = gen_label_rtx ();
4976 /* Initialize rtx used to return the value. */
4977 /* Do this before assign_parms so that we copy the struct value address
4978 before any library calls that assign parms might generate. */
4980 /* Decide whether to return the value in memory or in a register. */
4981 tree res = DECL_RESULT (subr);
4982 if (aggregate_value_p (res, subr))
4984 /* Returning something that won't go in a register. */
4985 rtx value_address = 0;
4987 #ifdef PCC_STATIC_STRUCT_RETURN
4988 if (cfun->returns_pcc_struct)
4990 int size = int_size_in_bytes (TREE_TYPE (res));
4991 value_address = assemble_static_space (size);
4993 else
4994 #endif
4996 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 2);
4997 /* Expect to be passed the address of a place to store the value.
4998 If it is passed as an argument, assign_parms will take care of
4999 it. */
5000 if (sv)
5002 value_address = gen_reg_rtx (Pmode);
5003 emit_move_insn (value_address, sv);
5006 if (value_address)
5008 rtx x = value_address;
5009 if (!DECL_BY_REFERENCE (res))
5011 x = gen_rtx_MEM (DECL_MODE (res), x);
5012 set_mem_attributes (x, res, 1);
5014 set_parm_rtl (res, x);
5017 else if (DECL_MODE (res) == VOIDmode)
5018 /* If return mode is void, this decl rtl should not be used. */
5019 set_parm_rtl (res, NULL_RTX);
5020 else
5022 /* Compute the return values into a pseudo reg, which we will copy
5023 into the true return register after the cleanups are done. */
5024 tree return_type = TREE_TYPE (res);
5026 /* If we may coalesce this result, make sure it has the expected mode
5027 in case it was promoted. But we need not bother about BLKmode. */
5028 machine_mode promoted_mode
5029 = flag_tree_coalesce_vars && is_gimple_reg (res)
5030 ? promote_ssa_mode (ssa_default_def (cfun, res), NULL)
5031 : BLKmode;
5033 if (promoted_mode != BLKmode)
5034 set_parm_rtl (res, gen_reg_rtx (promoted_mode));
5035 else if (TYPE_MODE (return_type) != BLKmode
5036 && targetm.calls.return_in_msb (return_type))
5037 /* expand_function_end will insert the appropriate padding in
5038 this case. Use the return value's natural (unpadded) mode
5039 within the function proper. */
5040 set_parm_rtl (res, gen_reg_rtx (TYPE_MODE (return_type)));
5041 else
5043 /* In order to figure out what mode to use for the pseudo, we
5044 figure out what the mode of the eventual return register will
5045 actually be, and use that. */
5046 rtx hard_reg = hard_function_value (return_type, subr, 0, 1);
5048 /* Structures that are returned in registers are not
5049 aggregate_value_p, so we may see a PARALLEL or a REG. */
5050 if (REG_P (hard_reg))
5051 set_parm_rtl (res, gen_reg_rtx (GET_MODE (hard_reg)));
5052 else
5054 gcc_assert (GET_CODE (hard_reg) == PARALLEL);
5055 set_parm_rtl (res, gen_group_rtx (hard_reg));
5059 /* Set DECL_REGISTER flag so that expand_function_end will copy the
5060 result to the real return register(s). */
5061 DECL_REGISTER (res) = 1;
5064 /* Initialize rtx for parameters and local variables.
5065 In some cases this requires emitting insns. */
5066 assign_parms (subr);
5068 /* If function gets a static chain arg, store it. */
5069 if (cfun->static_chain_decl)
5071 tree parm = cfun->static_chain_decl;
5072 rtx local, chain;
5073 rtx_insn *insn;
5074 int unsignedp;
5076 local = gen_reg_rtx (promote_decl_mode (parm, &unsignedp));
5077 chain = targetm.calls.static_chain (current_function_decl, true);
5079 set_decl_incoming_rtl (parm, chain, false);
5080 set_parm_rtl (parm, local);
5081 mark_reg_pointer (local, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
5083 if (GET_MODE (local) != GET_MODE (chain))
5085 convert_move (local, chain, unsignedp);
5086 insn = get_last_insn ();
5088 else
5089 insn = emit_move_insn (local, chain);
5091 /* Mark the register as eliminable, similar to parameters. */
5092 if (MEM_P (chain)
5093 && reg_mentioned_p (arg_pointer_rtx, XEXP (chain, 0)))
5094 set_dst_reg_note (insn, REG_EQUIV, chain, local);
5096 /* If we aren't optimizing, save the static chain onto the stack. */
5097 if (!optimize)
5099 tree saved_static_chain_decl
5100 = build_decl (DECL_SOURCE_LOCATION (parm), VAR_DECL,
5101 DECL_NAME (parm), TREE_TYPE (parm));
5102 rtx saved_static_chain_rtx
5103 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
5104 SET_DECL_RTL (saved_static_chain_decl, saved_static_chain_rtx);
5105 emit_move_insn (saved_static_chain_rtx, chain);
5106 SET_DECL_VALUE_EXPR (parm, saved_static_chain_decl);
5107 DECL_HAS_VALUE_EXPR_P (parm) = 1;
5111 /* The following was moved from init_function_start.
5112 The move was supposed to make sdb output more accurate. */
5113 /* Indicate the beginning of the function body,
5114 as opposed to parm setup. */
5115 emit_note (NOTE_INSN_FUNCTION_BEG);
5117 gcc_assert (NOTE_P (get_last_insn ()));
5119 parm_birth_insn = get_last_insn ();
5121 /* If the function receives a non-local goto, then store the
5122 bits we need to restore the frame pointer. */
5123 if (cfun->nonlocal_goto_save_area)
5125 tree t_save;
5126 rtx r_save;
5128 tree var = TREE_OPERAND (cfun->nonlocal_goto_save_area, 0);
5129 gcc_assert (DECL_RTL_SET_P (var));
5131 t_save = build4 (ARRAY_REF,
5132 TREE_TYPE (TREE_TYPE (cfun->nonlocal_goto_save_area)),
5133 cfun->nonlocal_goto_save_area,
5134 integer_zero_node, NULL_TREE, NULL_TREE);
5135 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
5136 gcc_assert (GET_MODE (r_save) == Pmode);
5138 emit_move_insn (r_save, hard_frame_pointer_rtx);
5139 update_nonlocal_goto_save_area ();
5142 if (crtl->profile)
5144 #ifdef PROFILE_HOOK
5145 PROFILE_HOOK (current_function_funcdef_no);
5146 #endif
5149 /* If we are doing generic stack checking, the probe should go here. */
5150 if (flag_stack_check == GENERIC_STACK_CHECK)
5151 stack_check_probe_note = emit_note (NOTE_INSN_DELETED);
5154 void
5155 pop_dummy_function (void)
5157 pop_cfun ();
5158 in_dummy_function = false;
5161 /* Undo the effects of init_dummy_function_start. */
5162 void
5163 expand_dummy_function_end (void)
5165 gcc_assert (in_dummy_function);
5167 /* End any sequences that failed to be closed due to syntax errors. */
5168 while (in_sequence_p ())
5169 end_sequence ();
5171 /* Outside function body, can't compute type's actual size
5172 until next function's body starts. */
5174 free_after_parsing (cfun);
5175 free_after_compilation (cfun);
5176 pop_dummy_function ();
5179 /* Helper for diddle_return_value. */
5181 void
5182 diddle_return_value_1 (void (*doit) (rtx, void *), void *arg, rtx outgoing)
5184 if (! outgoing)
5185 return;
5187 if (REG_P (outgoing))
5188 (*doit) (outgoing, arg);
5189 else if (GET_CODE (outgoing) == PARALLEL)
5191 int i;
5193 for (i = 0; i < XVECLEN (outgoing, 0); i++)
5195 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
5197 if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
5198 (*doit) (x, arg);
5203 /* Call DOIT for each hard register used as a return value from
5204 the current function. */
5206 void
5207 diddle_return_value (void (*doit) (rtx, void *), void *arg)
5209 diddle_return_value_1 (doit, arg, crtl->return_rtx);
5212 static void
5213 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
5215 emit_clobber (reg);
5218 void
5219 clobber_return_register (void)
5221 diddle_return_value (do_clobber_return_reg, NULL);
5223 /* In case we do use pseudo to return value, clobber it too. */
5224 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
5226 tree decl_result = DECL_RESULT (current_function_decl);
5227 rtx decl_rtl = DECL_RTL (decl_result);
5228 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
5230 do_clobber_return_reg (decl_rtl, NULL);
5235 static void
5236 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
5238 emit_use (reg);
5241 static void
5242 use_return_register (void)
5244 diddle_return_value (do_use_return_reg, NULL);
5247 /* Generate RTL for the end of the current function. */
5249 void
5250 expand_function_end (void)
5252 /* If arg_pointer_save_area was referenced only from a nested
5253 function, we will not have initialized it yet. Do that now. */
5254 if (arg_pointer_save_area && ! crtl->arg_pointer_save_area_init)
5255 get_arg_pointer_save_area ();
5257 /* If we are doing generic stack checking and this function makes calls,
5258 do a stack probe at the start of the function to ensure we have enough
5259 space for another stack frame. */
5260 if (flag_stack_check == GENERIC_STACK_CHECK)
5262 rtx_insn *insn, *seq;
5264 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
5265 if (CALL_P (insn))
5267 rtx max_frame_size = GEN_INT (STACK_CHECK_MAX_FRAME_SIZE);
5268 start_sequence ();
5269 if (STACK_CHECK_MOVING_SP)
5270 anti_adjust_stack_and_probe (max_frame_size, true);
5271 else
5272 probe_stack_range (STACK_OLD_CHECK_PROTECT, max_frame_size);
5273 seq = get_insns ();
5274 end_sequence ();
5275 set_insn_locations (seq, prologue_location);
5276 emit_insn_before (seq, stack_check_probe_note);
5277 break;
5281 /* End any sequences that failed to be closed due to syntax errors. */
5282 while (in_sequence_p ())
5283 end_sequence ();
5285 clear_pending_stack_adjust ();
5286 do_pending_stack_adjust ();
5288 /* Output a linenumber for the end of the function.
5289 SDB depended on this. */
5290 set_curr_insn_location (input_location);
5292 /* Before the return label (if any), clobber the return
5293 registers so that they are not propagated live to the rest of
5294 the function. This can only happen with functions that drop
5295 through; if there had been a return statement, there would
5296 have either been a return rtx, or a jump to the return label.
5298 We delay actual code generation after the current_function_value_rtx
5299 is computed. */
5300 rtx_insn *clobber_after = get_last_insn ();
5302 /* Output the label for the actual return from the function. */
5303 emit_label (return_label);
5305 if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ)
5307 /* Let except.c know where it should emit the call to unregister
5308 the function context for sjlj exceptions. */
5309 if (flag_exceptions)
5310 sjlj_emit_function_exit_after (get_last_insn ());
5313 /* If this is an implementation of throw, do what's necessary to
5314 communicate between __builtin_eh_return and the epilogue. */
5315 expand_eh_return ();
5317 /* If stack protection is enabled for this function, check the guard. */
5318 if (crtl->stack_protect_guard
5319 && targetm.stack_protect_runtime_enabled_p ()
5320 && naked_return_label == NULL_RTX)
5321 stack_protect_epilogue ();
5323 /* If scalar return value was computed in a pseudo-reg, or was a named
5324 return value that got dumped to the stack, copy that to the hard
5325 return register. */
5326 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
5328 tree decl_result = DECL_RESULT (current_function_decl);
5329 rtx decl_rtl = DECL_RTL (decl_result);
5331 if (REG_P (decl_rtl)
5332 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
5333 : DECL_REGISTER (decl_result))
5335 rtx real_decl_rtl = crtl->return_rtx;
5336 complex_mode cmode;
5338 /* This should be set in assign_parms. */
5339 gcc_assert (REG_FUNCTION_VALUE_P (real_decl_rtl));
5341 /* If this is a BLKmode structure being returned in registers,
5342 then use the mode computed in expand_return. Note that if
5343 decl_rtl is memory, then its mode may have been changed,
5344 but that crtl->return_rtx has not. */
5345 if (GET_MODE (real_decl_rtl) == BLKmode)
5346 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
5348 /* If a non-BLKmode return value should be padded at the least
5349 significant end of the register, shift it left by the appropriate
5350 amount. BLKmode results are handled using the group load/store
5351 machinery. */
5352 if (TYPE_MODE (TREE_TYPE (decl_result)) != BLKmode
5353 && REG_P (real_decl_rtl)
5354 && targetm.calls.return_in_msb (TREE_TYPE (decl_result)))
5356 emit_move_insn (gen_rtx_REG (GET_MODE (decl_rtl),
5357 REGNO (real_decl_rtl)),
5358 decl_rtl);
5359 shift_return_value (GET_MODE (decl_rtl), true, real_decl_rtl);
5361 else if (GET_CODE (real_decl_rtl) == PARALLEL)
5363 /* If expand_function_start has created a PARALLEL for decl_rtl,
5364 move the result to the real return registers. Otherwise, do
5365 a group load from decl_rtl for a named return. */
5366 if (GET_CODE (decl_rtl) == PARALLEL)
5367 emit_group_move (real_decl_rtl, decl_rtl);
5368 else
5369 emit_group_load (real_decl_rtl, decl_rtl,
5370 TREE_TYPE (decl_result),
5371 int_size_in_bytes (TREE_TYPE (decl_result)));
5373 /* In the case of complex integer modes smaller than a word, we'll
5374 need to generate some non-trivial bitfield insertions. Do that
5375 on a pseudo and not the hard register. */
5376 else if (GET_CODE (decl_rtl) == CONCAT
5377 && is_complex_int_mode (GET_MODE (decl_rtl), &cmode)
5378 && GET_MODE_BITSIZE (cmode) <= BITS_PER_WORD)
5380 int old_generating_concat_p;
5381 rtx tmp;
5383 old_generating_concat_p = generating_concat_p;
5384 generating_concat_p = 0;
5385 tmp = gen_reg_rtx (GET_MODE (decl_rtl));
5386 generating_concat_p = old_generating_concat_p;
5388 emit_move_insn (tmp, decl_rtl);
5389 emit_move_insn (real_decl_rtl, tmp);
5391 /* If a named return value dumped decl_return to memory, then
5392 we may need to re-do the PROMOTE_MODE signed/unsigned
5393 extension. */
5394 else if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
5396 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
5397 promote_function_mode (TREE_TYPE (decl_result),
5398 GET_MODE (decl_rtl), &unsignedp,
5399 TREE_TYPE (current_function_decl), 1);
5401 convert_move (real_decl_rtl, decl_rtl, unsignedp);
5403 else
5404 emit_move_insn (real_decl_rtl, decl_rtl);
5408 /* If returning a structure, arrange to return the address of the value
5409 in a place where debuggers expect to find it.
5411 If returning a structure PCC style,
5412 the caller also depends on this value.
5413 And cfun->returns_pcc_struct is not necessarily set. */
5414 if ((cfun->returns_struct || cfun->returns_pcc_struct)
5415 && !targetm.calls.omit_struct_return_reg)
5417 rtx value_address = DECL_RTL (DECL_RESULT (current_function_decl));
5418 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
5419 rtx outgoing;
5421 if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
5422 type = TREE_TYPE (type);
5423 else
5424 value_address = XEXP (value_address, 0);
5426 outgoing = targetm.calls.function_value (build_pointer_type (type),
5427 current_function_decl, true);
5429 /* Mark this as a function return value so integrate will delete the
5430 assignment and USE below when inlining this function. */
5431 REG_FUNCTION_VALUE_P (outgoing) = 1;
5433 /* The address may be ptr_mode and OUTGOING may be Pmode. */
5434 scalar_int_mode mode = as_a <scalar_int_mode> (GET_MODE (outgoing));
5435 value_address = convert_memory_address (mode, value_address);
5437 emit_move_insn (outgoing, value_address);
5439 /* Show return register used to hold result (in this case the address
5440 of the result. */
5441 crtl->return_rtx = outgoing;
5444 /* Emit the actual code to clobber return register. Don't emit
5445 it if clobber_after is a barrier, then the previous basic block
5446 certainly doesn't fall thru into the exit block. */
5447 if (!BARRIER_P (clobber_after))
5449 start_sequence ();
5450 clobber_return_register ();
5451 rtx_insn *seq = get_insns ();
5452 end_sequence ();
5454 emit_insn_after (seq, clobber_after);
5457 /* Output the label for the naked return from the function. */
5458 if (naked_return_label)
5459 emit_label (naked_return_label);
5461 /* @@@ This is a kludge. We want to ensure that instructions that
5462 may trap are not moved into the epilogue by scheduling, because
5463 we don't always emit unwind information for the epilogue. */
5464 if (cfun->can_throw_non_call_exceptions
5465 && targetm_common.except_unwind_info (&global_options) != UI_SJLJ)
5466 emit_insn (gen_blockage ());
5468 /* If stack protection is enabled for this function, check the guard. */
5469 if (crtl->stack_protect_guard
5470 && targetm.stack_protect_runtime_enabled_p ()
5471 && naked_return_label)
5472 stack_protect_epilogue ();
5474 /* If we had calls to alloca, and this machine needs
5475 an accurate stack pointer to exit the function,
5476 insert some code to save and restore the stack pointer. */
5477 if (! EXIT_IGNORE_STACK
5478 && cfun->calls_alloca)
5480 rtx tem = 0;
5482 start_sequence ();
5483 emit_stack_save (SAVE_FUNCTION, &tem);
5484 rtx_insn *seq = get_insns ();
5485 end_sequence ();
5486 emit_insn_before (seq, parm_birth_insn);
5488 emit_stack_restore (SAVE_FUNCTION, tem);
5491 /* ??? This should no longer be necessary since stupid is no longer with
5492 us, but there are some parts of the compiler (eg reload_combine, and
5493 sh mach_dep_reorg) that still try and compute their own lifetime info
5494 instead of using the general framework. */
5495 use_return_register ();
5499 get_arg_pointer_save_area (void)
5501 rtx ret = arg_pointer_save_area;
5503 if (! ret)
5505 ret = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
5506 arg_pointer_save_area = ret;
5509 if (! crtl->arg_pointer_save_area_init)
5511 /* Save the arg pointer at the beginning of the function. The
5512 generated stack slot may not be a valid memory address, so we
5513 have to check it and fix it if necessary. */
5514 start_sequence ();
5515 emit_move_insn (validize_mem (copy_rtx (ret)),
5516 crtl->args.internal_arg_pointer);
5517 rtx_insn *seq = get_insns ();
5518 end_sequence ();
5520 push_topmost_sequence ();
5521 emit_insn_after (seq, entry_of_function ());
5522 pop_topmost_sequence ();
5524 crtl->arg_pointer_save_area_init = true;
5527 return ret;
5531 /* If debugging dumps are requested, dump information about how the
5532 target handled -fstack-check=clash for the prologue.
5534 PROBES describes what if any probes were emitted.
5536 RESIDUALS indicates if the prologue had any residual allocation
5537 (i.e. total allocation was not a multiple of PROBE_INTERVAL). */
5539 void
5540 dump_stack_clash_frame_info (enum stack_clash_probes probes, bool residuals)
5542 if (!dump_file)
5543 return;
5545 switch (probes)
5547 case NO_PROBE_NO_FRAME:
5548 fprintf (dump_file,
5549 "Stack clash no probe no stack adjustment in prologue.\n");
5550 break;
5551 case NO_PROBE_SMALL_FRAME:
5552 fprintf (dump_file,
5553 "Stack clash no probe small stack adjustment in prologue.\n");
5554 break;
5555 case PROBE_INLINE:
5556 fprintf (dump_file, "Stack clash inline probes in prologue.\n");
5557 break;
5558 case PROBE_LOOP:
5559 fprintf (dump_file, "Stack clash probe loop in prologue.\n");
5560 break;
5563 if (residuals)
5564 fprintf (dump_file, "Stack clash residual allocation in prologue.\n");
5565 else
5566 fprintf (dump_file, "Stack clash no residual allocation in prologue.\n");
5568 if (frame_pointer_needed)
5569 fprintf (dump_file, "Stack clash frame pointer needed.\n");
5570 else
5571 fprintf (dump_file, "Stack clash no frame pointer needed.\n");
5573 if (TREE_THIS_VOLATILE (cfun->decl))
5574 fprintf (dump_file,
5575 "Stack clash noreturn prologue, assuming no implicit"
5576 " probes in caller.\n");
5577 else
5578 fprintf (dump_file,
5579 "Stack clash not noreturn prologue.\n");
5582 /* Add a list of INSNS to the hash HASHP, possibly allocating HASHP
5583 for the first time. */
5585 static void
5586 record_insns (rtx_insn *insns, rtx end, hash_table<insn_cache_hasher> **hashp)
5588 rtx_insn *tmp;
5589 hash_table<insn_cache_hasher> *hash = *hashp;
5591 if (hash == NULL)
5592 *hashp = hash = hash_table<insn_cache_hasher>::create_ggc (17);
5594 for (tmp = insns; tmp != end; tmp = NEXT_INSN (tmp))
5596 rtx *slot = hash->find_slot (tmp, INSERT);
5597 gcc_assert (*slot == NULL);
5598 *slot = tmp;
5602 /* INSN has been duplicated or replaced by as COPY, perhaps by duplicating a
5603 basic block, splitting or peepholes. If INSN is a prologue or epilogue
5604 insn, then record COPY as well. */
5606 void
5607 maybe_copy_prologue_epilogue_insn (rtx insn, rtx copy)
5609 hash_table<insn_cache_hasher> *hash;
5610 rtx *slot;
5612 hash = epilogue_insn_hash;
5613 if (!hash || !hash->find (insn))
5615 hash = prologue_insn_hash;
5616 if (!hash || !hash->find (insn))
5617 return;
5620 slot = hash->find_slot (copy, INSERT);
5621 gcc_assert (*slot == NULL);
5622 *slot = copy;
5625 /* Determine if any INSNs in HASH are, or are part of, INSN. Because
5626 we can be running after reorg, SEQUENCE rtl is possible. */
5628 static bool
5629 contains (const rtx_insn *insn, hash_table<insn_cache_hasher> *hash)
5631 if (hash == NULL)
5632 return false;
5634 if (NONJUMP_INSN_P (insn) && GET_CODE (PATTERN (insn)) == SEQUENCE)
5636 rtx_sequence *seq = as_a <rtx_sequence *> (PATTERN (insn));
5637 int i;
5638 for (i = seq->len () - 1; i >= 0; i--)
5639 if (hash->find (seq->element (i)))
5640 return true;
5641 return false;
5644 return hash->find (const_cast<rtx_insn *> (insn)) != NULL;
5648 prologue_contains (const rtx_insn *insn)
5650 return contains (insn, prologue_insn_hash);
5654 epilogue_contains (const rtx_insn *insn)
5656 return contains (insn, epilogue_insn_hash);
5660 prologue_epilogue_contains (const rtx_insn *insn)
5662 if (contains (insn, prologue_insn_hash))
5663 return 1;
5664 if (contains (insn, epilogue_insn_hash))
5665 return 1;
5666 return 0;
5669 void
5670 record_prologue_seq (rtx_insn *seq)
5672 record_insns (seq, NULL, &prologue_insn_hash);
5675 void
5676 record_epilogue_seq (rtx_insn *seq)
5678 record_insns (seq, NULL, &epilogue_insn_hash);
5681 /* Set JUMP_LABEL for a return insn. */
5683 void
5684 set_return_jump_label (rtx_insn *returnjump)
5686 rtx pat = PATTERN (returnjump);
5687 if (GET_CODE (pat) == PARALLEL)
5688 pat = XVECEXP (pat, 0, 0);
5689 if (ANY_RETURN_P (pat))
5690 JUMP_LABEL (returnjump) = pat;
5691 else
5692 JUMP_LABEL (returnjump) = ret_rtx;
5695 /* Return a sequence to be used as the split prologue for the current
5696 function, or NULL. */
5698 static rtx_insn *
5699 make_split_prologue_seq (void)
5701 if (!flag_split_stack
5702 || lookup_attribute ("no_split_stack", DECL_ATTRIBUTES (cfun->decl)))
5703 return NULL;
5705 start_sequence ();
5706 emit_insn (targetm.gen_split_stack_prologue ());
5707 rtx_insn *seq = get_insns ();
5708 end_sequence ();
5710 record_insns (seq, NULL, &prologue_insn_hash);
5711 set_insn_locations (seq, prologue_location);
5713 return seq;
5716 /* Return a sequence to be used as the prologue for the current function,
5717 or NULL. */
5719 static rtx_insn *
5720 make_prologue_seq (void)
5722 if (!targetm.have_prologue ())
5723 return NULL;
5725 start_sequence ();
5726 rtx_insn *seq = targetm.gen_prologue ();
5727 emit_insn (seq);
5729 /* Insert an explicit USE for the frame pointer
5730 if the profiling is on and the frame pointer is required. */
5731 if (crtl->profile && frame_pointer_needed)
5732 emit_use (hard_frame_pointer_rtx);
5734 /* Retain a map of the prologue insns. */
5735 record_insns (seq, NULL, &prologue_insn_hash);
5736 emit_note (NOTE_INSN_PROLOGUE_END);
5738 /* Ensure that instructions are not moved into the prologue when
5739 profiling is on. The call to the profiling routine can be
5740 emitted within the live range of a call-clobbered register. */
5741 if (!targetm.profile_before_prologue () && crtl->profile)
5742 emit_insn (gen_blockage ());
5744 seq = get_insns ();
5745 end_sequence ();
5746 set_insn_locations (seq, prologue_location);
5748 return seq;
5751 /* Return a sequence to be used as the epilogue for the current function,
5752 or NULL. */
5754 static rtx_insn *
5755 make_epilogue_seq (void)
5757 if (!targetm.have_epilogue ())
5758 return NULL;
5760 start_sequence ();
5761 emit_note (NOTE_INSN_EPILOGUE_BEG);
5762 rtx_insn *seq = targetm.gen_epilogue ();
5763 if (seq)
5764 emit_jump_insn (seq);
5766 /* Retain a map of the epilogue insns. */
5767 record_insns (seq, NULL, &epilogue_insn_hash);
5768 set_insn_locations (seq, epilogue_location);
5770 seq = get_insns ();
5771 rtx_insn *returnjump = get_last_insn ();
5772 end_sequence ();
5774 if (JUMP_P (returnjump))
5775 set_return_jump_label (returnjump);
5777 return seq;
5781 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
5782 this into place with notes indicating where the prologue ends and where
5783 the epilogue begins. Update the basic block information when possible.
5785 Notes on epilogue placement:
5786 There are several kinds of edges to the exit block:
5787 * a single fallthru edge from LAST_BB
5788 * possibly, edges from blocks containing sibcalls
5789 * possibly, fake edges from infinite loops
5791 The epilogue is always emitted on the fallthru edge from the last basic
5792 block in the function, LAST_BB, into the exit block.
5794 If LAST_BB is empty except for a label, it is the target of every
5795 other basic block in the function that ends in a return. If a
5796 target has a return or simple_return pattern (possibly with
5797 conditional variants), these basic blocks can be changed so that a
5798 return insn is emitted into them, and their target is adjusted to
5799 the real exit block.
5801 Notes on shrink wrapping: We implement a fairly conservative
5802 version of shrink-wrapping rather than the textbook one. We only
5803 generate a single prologue and a single epilogue. This is
5804 sufficient to catch a number of interesting cases involving early
5805 exits.
5807 First, we identify the blocks that require the prologue to occur before
5808 them. These are the ones that modify a call-saved register, or reference
5809 any of the stack or frame pointer registers. To simplify things, we then
5810 mark everything reachable from these blocks as also requiring a prologue.
5811 This takes care of loops automatically, and avoids the need to examine
5812 whether MEMs reference the frame, since it is sufficient to check for
5813 occurrences of the stack or frame pointer.
5815 We then compute the set of blocks for which the need for a prologue
5816 is anticipatable (borrowing terminology from the shrink-wrapping
5817 description in Muchnick's book). These are the blocks which either
5818 require a prologue themselves, or those that have only successors
5819 where the prologue is anticipatable. The prologue needs to be
5820 inserted on all edges from BB1->BB2 where BB2 is in ANTIC and BB1
5821 is not. For the moment, we ensure that only one such edge exists.
5823 The epilogue is placed as described above, but we make a
5824 distinction between inserting return and simple_return patterns
5825 when modifying other blocks that end in a return. Blocks that end
5826 in a sibcall omit the sibcall_epilogue if the block is not in
5827 ANTIC. */
5829 void
5830 thread_prologue_and_epilogue_insns (void)
5832 df_analyze ();
5834 /* Can't deal with multiple successors of the entry block at the
5835 moment. Function should always have at least one entry
5836 point. */
5837 gcc_assert (single_succ_p (ENTRY_BLOCK_PTR_FOR_FN (cfun)));
5839 edge entry_edge = single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun));
5840 edge orig_entry_edge = entry_edge;
5842 rtx_insn *split_prologue_seq = make_split_prologue_seq ();
5843 rtx_insn *prologue_seq = make_prologue_seq ();
5844 rtx_insn *epilogue_seq = make_epilogue_seq ();
5846 /* Try to perform a kind of shrink-wrapping, making sure the
5847 prologue/epilogue is emitted only around those parts of the
5848 function that require it. */
5849 try_shrink_wrapping (&entry_edge, prologue_seq);
5851 /* If the target can handle splitting the prologue/epilogue into separate
5852 components, try to shrink-wrap these components separately. */
5853 try_shrink_wrapping_separate (entry_edge->dest);
5855 /* If that did anything for any component we now need the generate the
5856 "main" prologue again. Because some targets require some of these
5857 to be called in a specific order (i386 requires the split prologue
5858 to be first, for example), we create all three sequences again here.
5859 If this does not work for some target, that target should not enable
5860 separate shrink-wrapping. */
5861 if (crtl->shrink_wrapped_separate)
5863 split_prologue_seq = make_split_prologue_seq ();
5864 prologue_seq = make_prologue_seq ();
5865 epilogue_seq = make_epilogue_seq ();
5868 rtl_profile_for_bb (EXIT_BLOCK_PTR_FOR_FN (cfun));
5870 /* A small fib -- epilogue is not yet completed, but we wish to re-use
5871 this marker for the splits of EH_RETURN patterns, and nothing else
5872 uses the flag in the meantime. */
5873 epilogue_completed = 1;
5875 /* Find non-fallthru edges that end with EH_RETURN instructions. On
5876 some targets, these get split to a special version of the epilogue
5877 code. In order to be able to properly annotate these with unwind
5878 info, try to split them now. If we get a valid split, drop an
5879 EPILOGUE_BEG note and mark the insns as epilogue insns. */
5880 edge e;
5881 edge_iterator ei;
5882 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
5884 rtx_insn *prev, *last, *trial;
5886 if (e->flags & EDGE_FALLTHRU)
5887 continue;
5888 last = BB_END (e->src);
5889 if (!eh_returnjump_p (last))
5890 continue;
5892 prev = PREV_INSN (last);
5893 trial = try_split (PATTERN (last), last, 1);
5894 if (trial == last)
5895 continue;
5897 record_insns (NEXT_INSN (prev), NEXT_INSN (trial), &epilogue_insn_hash);
5898 emit_note_after (NOTE_INSN_EPILOGUE_BEG, prev);
5901 edge exit_fallthru_edge = find_fallthru_edge (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds);
5903 if (exit_fallthru_edge)
5905 if (epilogue_seq)
5907 insert_insn_on_edge (epilogue_seq, exit_fallthru_edge);
5908 commit_edge_insertions ();
5910 /* The epilogue insns we inserted may cause the exit edge to no longer
5911 be fallthru. */
5912 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
5914 if (((e->flags & EDGE_FALLTHRU) != 0)
5915 && returnjump_p (BB_END (e->src)))
5916 e->flags &= ~EDGE_FALLTHRU;
5919 else if (next_active_insn (BB_END (exit_fallthru_edge->src)))
5921 /* We have a fall-through edge to the exit block, the source is not
5922 at the end of the function, and there will be an assembler epilogue
5923 at the end of the function.
5924 We can't use force_nonfallthru here, because that would try to
5925 use return. Inserting a jump 'by hand' is extremely messy, so
5926 we take advantage of cfg_layout_finalize using
5927 fixup_fallthru_exit_predecessor. */
5928 cfg_layout_initialize (0);
5929 basic_block cur_bb;
5930 FOR_EACH_BB_FN (cur_bb, cfun)
5931 if (cur_bb->index >= NUM_FIXED_BLOCKS
5932 && cur_bb->next_bb->index >= NUM_FIXED_BLOCKS)
5933 cur_bb->aux = cur_bb->next_bb;
5934 cfg_layout_finalize ();
5938 /* Insert the prologue. */
5940 rtl_profile_for_bb (ENTRY_BLOCK_PTR_FOR_FN (cfun));
5942 if (split_prologue_seq || prologue_seq)
5944 rtx_insn *split_prologue_insn = split_prologue_seq;
5945 if (split_prologue_seq)
5947 while (split_prologue_insn && !NONDEBUG_INSN_P (split_prologue_insn))
5948 split_prologue_insn = NEXT_INSN (split_prologue_insn);
5949 insert_insn_on_edge (split_prologue_seq, orig_entry_edge);
5952 rtx_insn *prologue_insn = prologue_seq;
5953 if (prologue_seq)
5955 while (prologue_insn && !NONDEBUG_INSN_P (prologue_insn))
5956 prologue_insn = NEXT_INSN (prologue_insn);
5957 insert_insn_on_edge (prologue_seq, entry_edge);
5960 commit_edge_insertions ();
5962 /* Look for basic blocks within the prologue insns. */
5963 if (split_prologue_insn
5964 && BLOCK_FOR_INSN (split_prologue_insn) == NULL)
5965 split_prologue_insn = NULL;
5966 if (prologue_insn
5967 && BLOCK_FOR_INSN (prologue_insn) == NULL)
5968 prologue_insn = NULL;
5969 if (split_prologue_insn || prologue_insn)
5971 auto_sbitmap blocks (last_basic_block_for_fn (cfun));
5972 bitmap_clear (blocks);
5973 if (split_prologue_insn)
5974 bitmap_set_bit (blocks,
5975 BLOCK_FOR_INSN (split_prologue_insn)->index);
5976 if (prologue_insn)
5977 bitmap_set_bit (blocks, BLOCK_FOR_INSN (prologue_insn)->index);
5978 find_many_sub_basic_blocks (blocks);
5982 default_rtl_profile ();
5984 /* Emit sibling epilogues before any sibling call sites. */
5985 for (ei = ei_start (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds);
5986 (e = ei_safe_edge (ei));
5987 ei_next (&ei))
5989 /* Skip those already handled, the ones that run without prologue. */
5990 if (e->flags & EDGE_IGNORE)
5992 e->flags &= ~EDGE_IGNORE;
5993 continue;
5996 rtx_insn *insn = BB_END (e->src);
5998 if (!(CALL_P (insn) && SIBLING_CALL_P (insn)))
5999 continue;
6001 if (rtx_insn *ep_seq = targetm.gen_sibcall_epilogue ())
6003 start_sequence ();
6004 emit_note (NOTE_INSN_EPILOGUE_BEG);
6005 emit_insn (ep_seq);
6006 rtx_insn *seq = get_insns ();
6007 end_sequence ();
6009 /* Retain a map of the epilogue insns. Used in life analysis to
6010 avoid getting rid of sibcall epilogue insns. Do this before we
6011 actually emit the sequence. */
6012 record_insns (seq, NULL, &epilogue_insn_hash);
6013 set_insn_locations (seq, epilogue_location);
6015 emit_insn_before (seq, insn);
6019 if (epilogue_seq)
6021 rtx_insn *insn, *next;
6023 /* Similarly, move any line notes that appear after the epilogue.
6024 There is no need, however, to be quite so anal about the existence
6025 of such a note. Also possibly move
6026 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
6027 info generation. */
6028 for (insn = epilogue_seq; insn; insn = next)
6030 next = NEXT_INSN (insn);
6031 if (NOTE_P (insn)
6032 && (NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG))
6033 reorder_insns (insn, insn, PREV_INSN (epilogue_seq));
6037 /* Threading the prologue and epilogue changes the artificial refs
6038 in the entry and exit blocks. */
6039 epilogue_completed = 1;
6040 df_update_entry_exit_and_calls ();
6043 /* Reposition the prologue-end and epilogue-begin notes after
6044 instruction scheduling. */
6046 void
6047 reposition_prologue_and_epilogue_notes (void)
6049 if (!targetm.have_prologue ()
6050 && !targetm.have_epilogue ()
6051 && !targetm.have_sibcall_epilogue ())
6052 return;
6054 /* Since the hash table is created on demand, the fact that it is
6055 non-null is a signal that it is non-empty. */
6056 if (prologue_insn_hash != NULL)
6058 size_t len = prologue_insn_hash->elements ();
6059 rtx_insn *insn, *last = NULL, *note = NULL;
6061 /* Scan from the beginning until we reach the last prologue insn. */
6062 /* ??? While we do have the CFG intact, there are two problems:
6063 (1) The prologue can contain loops (typically probing the stack),
6064 which means that the end of the prologue isn't in the first bb.
6065 (2) Sometimes the PROLOGUE_END note gets pushed into the next bb. */
6066 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
6068 if (NOTE_P (insn))
6070 if (NOTE_KIND (insn) == NOTE_INSN_PROLOGUE_END)
6071 note = insn;
6073 else if (contains (insn, prologue_insn_hash))
6075 last = insn;
6076 if (--len == 0)
6077 break;
6081 if (last)
6083 if (note == NULL)
6085 /* Scan forward looking for the PROLOGUE_END note. It should
6086 be right at the beginning of the block, possibly with other
6087 insn notes that got moved there. */
6088 for (note = NEXT_INSN (last); ; note = NEXT_INSN (note))
6090 if (NOTE_P (note)
6091 && NOTE_KIND (note) == NOTE_INSN_PROLOGUE_END)
6092 break;
6096 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
6097 if (LABEL_P (last))
6098 last = NEXT_INSN (last);
6099 reorder_insns (note, note, last);
6103 if (epilogue_insn_hash != NULL)
6105 edge_iterator ei;
6106 edge e;
6108 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
6110 rtx_insn *insn, *first = NULL, *note = NULL;
6111 basic_block bb = e->src;
6113 /* Scan from the beginning until we reach the first epilogue insn. */
6114 FOR_BB_INSNS (bb, insn)
6116 if (NOTE_P (insn))
6118 if (NOTE_KIND (insn) == NOTE_INSN_EPILOGUE_BEG)
6120 note = insn;
6121 if (first != NULL)
6122 break;
6125 else if (first == NULL && contains (insn, epilogue_insn_hash))
6127 first = insn;
6128 if (note != NULL)
6129 break;
6133 if (note)
6135 /* If the function has a single basic block, and no real
6136 epilogue insns (e.g. sibcall with no cleanup), the
6137 epilogue note can get scheduled before the prologue
6138 note. If we have frame related prologue insns, having
6139 them scanned during the epilogue will result in a crash.
6140 In this case re-order the epilogue note to just before
6141 the last insn in the block. */
6142 if (first == NULL)
6143 first = BB_END (bb);
6145 if (PREV_INSN (first) != note)
6146 reorder_insns (note, note, PREV_INSN (first));
6152 /* Returns the name of function declared by FNDECL. */
6153 const char *
6154 fndecl_name (tree fndecl)
6156 if (fndecl == NULL)
6157 return "(nofn)";
6158 return lang_hooks.decl_printable_name (fndecl, 1);
6161 /* Returns the name of function FN. */
6162 const char *
6163 function_name (struct function *fn)
6165 tree fndecl = (fn == NULL) ? NULL : fn->decl;
6166 return fndecl_name (fndecl);
6169 /* Returns the name of the current function. */
6170 const char *
6171 current_function_name (void)
6173 return function_name (cfun);
6177 static unsigned int
6178 rest_of_handle_check_leaf_regs (void)
6180 #ifdef LEAF_REGISTERS
6181 crtl->uses_only_leaf_regs
6182 = optimize > 0 && only_leaf_regs_used () && leaf_function_p ();
6183 #endif
6184 return 0;
6187 /* Insert a TYPE into the used types hash table of CFUN. */
6189 static void
6190 used_types_insert_helper (tree type, struct function *func)
6192 if (type != NULL && func != NULL)
6194 if (func->used_types_hash == NULL)
6195 func->used_types_hash = hash_set<tree>::create_ggc (37);
6197 func->used_types_hash->add (type);
6201 /* Given a type, insert it into the used hash table in cfun. */
6202 void
6203 used_types_insert (tree t)
6205 while (POINTER_TYPE_P (t) || TREE_CODE (t) == ARRAY_TYPE)
6206 if (TYPE_NAME (t))
6207 break;
6208 else
6209 t = TREE_TYPE (t);
6210 if (TREE_CODE (t) == ERROR_MARK)
6211 return;
6212 if (TYPE_NAME (t) == NULL_TREE
6213 || TYPE_NAME (t) == TYPE_NAME (TYPE_MAIN_VARIANT (t)))
6214 t = TYPE_MAIN_VARIANT (t);
6215 if (debug_info_level > DINFO_LEVEL_NONE)
6217 if (cfun)
6218 used_types_insert_helper (t, cfun);
6219 else
6221 /* So this might be a type referenced by a global variable.
6222 Record that type so that we can later decide to emit its
6223 debug information. */
6224 vec_safe_push (types_used_by_cur_var_decl, t);
6229 /* Helper to Hash a struct types_used_by_vars_entry. */
6231 static hashval_t
6232 hash_types_used_by_vars_entry (const struct types_used_by_vars_entry *entry)
6234 gcc_assert (entry && entry->var_decl && entry->type);
6236 return iterative_hash_object (entry->type,
6237 iterative_hash_object (entry->var_decl, 0));
6240 /* Hash function of the types_used_by_vars_entry hash table. */
6242 hashval_t
6243 used_type_hasher::hash (types_used_by_vars_entry *entry)
6245 return hash_types_used_by_vars_entry (entry);
6248 /*Equality function of the types_used_by_vars_entry hash table. */
6250 bool
6251 used_type_hasher::equal (types_used_by_vars_entry *e1,
6252 types_used_by_vars_entry *e2)
6254 return (e1->var_decl == e2->var_decl && e1->type == e2->type);
6257 /* Inserts an entry into the types_used_by_vars_hash hash table. */
6259 void
6260 types_used_by_var_decl_insert (tree type, tree var_decl)
6262 if (type != NULL && var_decl != NULL)
6264 types_used_by_vars_entry **slot;
6265 struct types_used_by_vars_entry e;
6266 e.var_decl = var_decl;
6267 e.type = type;
6268 if (types_used_by_vars_hash == NULL)
6269 types_used_by_vars_hash
6270 = hash_table<used_type_hasher>::create_ggc (37);
6272 slot = types_used_by_vars_hash->find_slot (&e, INSERT);
6273 if (*slot == NULL)
6275 struct types_used_by_vars_entry *entry;
6276 entry = ggc_alloc<types_used_by_vars_entry> ();
6277 entry->type = type;
6278 entry->var_decl = var_decl;
6279 *slot = entry;
6284 namespace {
6286 const pass_data pass_data_leaf_regs =
6288 RTL_PASS, /* type */
6289 "*leaf_regs", /* name */
6290 OPTGROUP_NONE, /* optinfo_flags */
6291 TV_NONE, /* tv_id */
6292 0, /* properties_required */
6293 0, /* properties_provided */
6294 0, /* properties_destroyed */
6295 0, /* todo_flags_start */
6296 0, /* todo_flags_finish */
6299 class pass_leaf_regs : public rtl_opt_pass
6301 public:
6302 pass_leaf_regs (gcc::context *ctxt)
6303 : rtl_opt_pass (pass_data_leaf_regs, ctxt)
6306 /* opt_pass methods: */
6307 virtual unsigned int execute (function *)
6309 return rest_of_handle_check_leaf_regs ();
6312 }; // class pass_leaf_regs
6314 } // anon namespace
6316 rtl_opt_pass *
6317 make_pass_leaf_regs (gcc::context *ctxt)
6319 return new pass_leaf_regs (ctxt);
6322 static unsigned int
6323 rest_of_handle_thread_prologue_and_epilogue (void)
6325 /* prepare_shrink_wrap is sensitive to the block structure of the control
6326 flow graph, so clean it up first. */
6327 if (optimize)
6328 cleanup_cfg (0);
6330 /* On some machines, the prologue and epilogue code, or parts thereof,
6331 can be represented as RTL. Doing so lets us schedule insns between
6332 it and the rest of the code and also allows delayed branch
6333 scheduling to operate in the epilogue. */
6334 thread_prologue_and_epilogue_insns ();
6336 /* Some non-cold blocks may now be only reachable from cold blocks.
6337 Fix that up. */
6338 fixup_partitions ();
6340 /* Shrink-wrapping can result in unreachable edges in the epilogue,
6341 see PR57320. */
6342 cleanup_cfg (optimize ? CLEANUP_EXPENSIVE : 0);
6344 /* The stack usage info is finalized during prologue expansion. */
6345 if (flag_stack_usage_info)
6346 output_stack_usage ();
6348 return 0;
6351 namespace {
6353 const pass_data pass_data_thread_prologue_and_epilogue =
6355 RTL_PASS, /* type */
6356 "pro_and_epilogue", /* name */
6357 OPTGROUP_NONE, /* optinfo_flags */
6358 TV_THREAD_PROLOGUE_AND_EPILOGUE, /* tv_id */
6359 0, /* properties_required */
6360 0, /* properties_provided */
6361 0, /* properties_destroyed */
6362 0, /* todo_flags_start */
6363 ( TODO_df_verify | TODO_df_finish ), /* todo_flags_finish */
6366 class pass_thread_prologue_and_epilogue : public rtl_opt_pass
6368 public:
6369 pass_thread_prologue_and_epilogue (gcc::context *ctxt)
6370 : rtl_opt_pass (pass_data_thread_prologue_and_epilogue, ctxt)
6373 /* opt_pass methods: */
6374 virtual unsigned int execute (function *)
6376 return rest_of_handle_thread_prologue_and_epilogue ();
6379 }; // class pass_thread_prologue_and_epilogue
6381 } // anon namespace
6383 rtl_opt_pass *
6384 make_pass_thread_prologue_and_epilogue (gcc::context *ctxt)
6386 return new pass_thread_prologue_and_epilogue (ctxt);
6390 /* If CONSTRAINT is a matching constraint, then return its number.
6391 Otherwise, return -1. */
6393 static int
6394 matching_constraint_num (const char *constraint)
6396 if (*constraint == '%')
6397 constraint++;
6399 if (IN_RANGE (*constraint, '0', '9'))
6400 return strtoul (constraint, NULL, 10);
6402 return -1;
6405 /* This mini-pass fixes fall-out from SSA in asm statements that have
6406 in-out constraints. Say you start with
6408 orig = inout;
6409 asm ("": "+mr" (inout));
6410 use (orig);
6412 which is transformed very early to use explicit output and match operands:
6414 orig = inout;
6415 asm ("": "=mr" (inout) : "0" (inout));
6416 use (orig);
6418 Or, after SSA and copyprop,
6420 asm ("": "=mr" (inout_2) : "0" (inout_1));
6421 use (inout_1);
6423 Clearly inout_2 and inout_1 can't be coalesced easily anymore, as
6424 they represent two separate values, so they will get different pseudo
6425 registers during expansion. Then, since the two operands need to match
6426 per the constraints, but use different pseudo registers, reload can
6427 only register a reload for these operands. But reloads can only be
6428 satisfied by hardregs, not by memory, so we need a register for this
6429 reload, just because we are presented with non-matching operands.
6430 So, even though we allow memory for this operand, no memory can be
6431 used for it, just because the two operands don't match. This can
6432 cause reload failures on register-starved targets.
6434 So it's a symptom of reload not being able to use memory for reloads
6435 or, alternatively it's also a symptom of both operands not coming into
6436 reload as matching (in which case the pseudo could go to memory just
6437 fine, as the alternative allows it, and no reload would be necessary).
6438 We fix the latter problem here, by transforming
6440 asm ("": "=mr" (inout_2) : "0" (inout_1));
6442 back to
6444 inout_2 = inout_1;
6445 asm ("": "=mr" (inout_2) : "0" (inout_2)); */
6447 static void
6448 match_asm_constraints_1 (rtx_insn *insn, rtx *p_sets, int noutputs)
6450 int i;
6451 bool changed = false;
6452 rtx op = SET_SRC (p_sets[0]);
6453 int ninputs = ASM_OPERANDS_INPUT_LENGTH (op);
6454 rtvec inputs = ASM_OPERANDS_INPUT_VEC (op);
6455 bool *output_matched = XALLOCAVEC (bool, noutputs);
6457 memset (output_matched, 0, noutputs * sizeof (bool));
6458 for (i = 0; i < ninputs; i++)
6460 rtx input, output;
6461 rtx_insn *insns;
6462 const char *constraint = ASM_OPERANDS_INPUT_CONSTRAINT (op, i);
6463 int match, j;
6465 match = matching_constraint_num (constraint);
6466 if (match < 0)
6467 continue;
6469 gcc_assert (match < noutputs);
6470 output = SET_DEST (p_sets[match]);
6471 input = RTVEC_ELT (inputs, i);
6472 /* Only do the transformation for pseudos. */
6473 if (! REG_P (output)
6474 || rtx_equal_p (output, input)
6475 || !(REG_P (input) || SUBREG_P (input)
6476 || MEM_P (input) || CONSTANT_P (input))
6477 || !general_operand (input, GET_MODE (output)))
6478 continue;
6480 /* We can't do anything if the output is also used as input,
6481 as we're going to overwrite it. */
6482 for (j = 0; j < ninputs; j++)
6483 if (reg_overlap_mentioned_p (output, RTVEC_ELT (inputs, j)))
6484 break;
6485 if (j != ninputs)
6486 continue;
6488 /* Avoid changing the same input several times. For
6489 asm ("" : "=mr" (out1), "=mr" (out2) : "0" (in), "1" (in));
6490 only change it once (to out1), rather than changing it
6491 first to out1 and afterwards to out2. */
6492 if (i > 0)
6494 for (j = 0; j < noutputs; j++)
6495 if (output_matched[j] && input == SET_DEST (p_sets[j]))
6496 break;
6497 if (j != noutputs)
6498 continue;
6500 output_matched[match] = true;
6502 start_sequence ();
6503 emit_move_insn (output, copy_rtx (input));
6504 insns = get_insns ();
6505 end_sequence ();
6506 emit_insn_before (insns, insn);
6508 constraint = ASM_OPERANDS_OUTPUT_CONSTRAINT(SET_SRC(p_sets[match]));
6509 bool early_clobber_p = strchr (constraint, '&') != NULL;
6511 /* Now replace all mentions of the input with output. We can't
6512 just replace the occurrence in inputs[i], as the register might
6513 also be used in some other input (or even in an address of an
6514 output), which would mean possibly increasing the number of
6515 inputs by one (namely 'output' in addition), which might pose
6516 a too complicated problem for reload to solve. E.g. this situation:
6518 asm ("" : "=r" (output), "=m" (input) : "0" (input))
6520 Here 'input' is used in two occurrences as input (once for the
6521 input operand, once for the address in the second output operand).
6522 If we would replace only the occurrence of the input operand (to
6523 make the matching) we would be left with this:
6525 output = input
6526 asm ("" : "=r" (output), "=m" (input) : "0" (output))
6528 Now we suddenly have two different input values (containing the same
6529 value, but different pseudos) where we formerly had only one.
6530 With more complicated asms this might lead to reload failures
6531 which wouldn't have happen without this pass. So, iterate over
6532 all operands and replace all occurrences of the register used.
6534 However, if one or more of the 'input' uses have a non-matching
6535 constraint and the matched output operand is an early clobber
6536 operand, then do not replace the input operand, since by definition
6537 it conflicts with the output operand and cannot share the same
6538 register. See PR89313 for details. */
6540 for (j = 0; j < noutputs; j++)
6541 if (!rtx_equal_p (SET_DEST (p_sets[j]), input)
6542 && reg_overlap_mentioned_p (input, SET_DEST (p_sets[j])))
6543 SET_DEST (p_sets[j]) = replace_rtx (SET_DEST (p_sets[j]),
6544 input, output);
6545 for (j = 0; j < ninputs; j++)
6546 if (reg_overlap_mentioned_p (input, RTVEC_ELT (inputs, j)))
6548 if (!early_clobber_p
6549 || match == matching_constraint_num
6550 (ASM_OPERANDS_INPUT_CONSTRAINT (op, j)))
6551 RTVEC_ELT (inputs, j) = replace_rtx (RTVEC_ELT (inputs, j),
6552 input, output);
6555 changed = true;
6558 if (changed)
6559 df_insn_rescan (insn);
6562 /* Add the decl D to the local_decls list of FUN. */
6564 void
6565 add_local_decl (struct function *fun, tree d)
6567 gcc_assert (VAR_P (d));
6568 vec_safe_push (fun->local_decls, d);
6571 namespace {
6573 const pass_data pass_data_match_asm_constraints =
6575 RTL_PASS, /* type */
6576 "asmcons", /* name */
6577 OPTGROUP_NONE, /* optinfo_flags */
6578 TV_NONE, /* tv_id */
6579 0, /* properties_required */
6580 0, /* properties_provided */
6581 0, /* properties_destroyed */
6582 0, /* todo_flags_start */
6583 0, /* todo_flags_finish */
6586 class pass_match_asm_constraints : public rtl_opt_pass
6588 public:
6589 pass_match_asm_constraints (gcc::context *ctxt)
6590 : rtl_opt_pass (pass_data_match_asm_constraints, ctxt)
6593 /* opt_pass methods: */
6594 virtual unsigned int execute (function *);
6596 }; // class pass_match_asm_constraints
6598 unsigned
6599 pass_match_asm_constraints::execute (function *fun)
6601 basic_block bb;
6602 rtx_insn *insn;
6603 rtx pat, *p_sets;
6604 int noutputs;
6606 if (!crtl->has_asm_statement)
6607 return 0;
6609 df_set_flags (DF_DEFER_INSN_RESCAN);
6610 FOR_EACH_BB_FN (bb, fun)
6612 FOR_BB_INSNS (bb, insn)
6614 if (!INSN_P (insn))
6615 continue;
6617 pat = PATTERN (insn);
6618 if (GET_CODE (pat) == PARALLEL)
6619 p_sets = &XVECEXP (pat, 0, 0), noutputs = XVECLEN (pat, 0);
6620 else if (GET_CODE (pat) == SET)
6621 p_sets = &PATTERN (insn), noutputs = 1;
6622 else
6623 continue;
6625 if (GET_CODE (*p_sets) == SET
6626 && GET_CODE (SET_SRC (*p_sets)) == ASM_OPERANDS)
6627 match_asm_constraints_1 (insn, p_sets, noutputs);
6631 return TODO_df_finish;
6634 } // anon namespace
6636 rtl_opt_pass *
6637 make_pass_match_asm_constraints (gcc::context *ctxt)
6639 return new pass_match_asm_constraints (ctxt);
6643 #include "gt-function.h"