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1 /* Expands front end tree to back end RTL for GCC.
2 Copyright (C) 1987-2018 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 struct temp_slot *find_temp_slot_from_address (rtx);
137 static void pad_to_arg_alignment (struct args_size *, int, struct args_size *);
138 static void pad_below (struct args_size *, machine_mode, tree);
139 static void reorder_blocks_1 (rtx_insn *, tree, vec<tree> *);
140 static int all_blocks (tree, tree *);
141 static tree *get_block_vector (tree, int *);
142 extern tree debug_find_var_in_block_tree (tree, tree);
143 /* We always define `record_insns' even if it's not used so that we
144 can always export `prologue_epilogue_contains'. */
145 static void record_insns (rtx_insn *, rtx, hash_table<insn_cache_hasher> **)
146 ATTRIBUTE_UNUSED;
147 static bool contains (const rtx_insn *, hash_table<insn_cache_hasher> *);
148 static void prepare_function_start (void);
149 static void do_clobber_return_reg (rtx, void *);
150 static void do_use_return_reg (rtx, void *);
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 struct frame_space *space = ggc_alloc<frame_space> ();
349 space->next = crtl->frame_space_list;
350 crtl->frame_space_list = space;
351 space->start = start;
352 space->length = end - start;
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;
380 bool dynamic_align_addr = false;
382 if (align == 0)
384 alignment = get_stack_local_alignment (NULL, mode);
385 alignment /= BITS_PER_UNIT;
387 else if (align == -1)
389 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
390 size = aligned_upper_bound (size, alignment);
392 else if (align == -2)
393 alignment = 1; /* BITS_PER_UNIT / BITS_PER_UNIT */
394 else
395 alignment = align / BITS_PER_UNIT;
397 alignment_in_bits = alignment * BITS_PER_UNIT;
399 if (alignment_in_bits > MAX_SUPPORTED_STACK_ALIGNMENT)
401 /* If the required alignment exceeds MAX_SUPPORTED_STACK_ALIGNMENT and
402 it is not OK to reduce it. Align the slot dynamically. */
403 if (mode == BLKmode && (kind & ASLK_REDUCE_ALIGN) == 0)
404 dynamic_align_addr = true;
405 else
407 alignment_in_bits = MAX_SUPPORTED_STACK_ALIGNMENT;
408 alignment = MAX_SUPPORTED_STACK_ALIGNMENT / BITS_PER_UNIT;
412 if (SUPPORTS_STACK_ALIGNMENT && !dynamic_align_addr)
414 if (crtl->stack_alignment_estimated < alignment_in_bits)
416 if (!crtl->stack_realign_processed)
417 crtl->stack_alignment_estimated = alignment_in_bits;
418 else
420 /* If stack is realigned and stack alignment value
421 hasn't been finalized, it is OK not to increase
422 stack_alignment_estimated. The bigger alignment
423 requirement is recorded in stack_alignment_needed
424 below. */
425 gcc_assert (!crtl->stack_realign_finalized);
426 if (!crtl->stack_realign_needed)
428 /* It is OK to reduce the alignment as long as the
429 requested size is 0 or the estimated stack
430 alignment >= mode alignment. */
431 gcc_assert ((kind & ASLK_REDUCE_ALIGN)
432 || known_eq (size, 0)
433 || (crtl->stack_alignment_estimated
434 >= GET_MODE_ALIGNMENT (mode)));
435 alignment_in_bits = crtl->stack_alignment_estimated;
436 alignment = alignment_in_bits / BITS_PER_UNIT;
442 /* Handle overalignment here for parameter copy on the stack.
443 Reserved enough space for it and dynamically align the address.
444 No free frame_space is added here. */
445 if (dynamic_align_addr)
447 rtx allocsize = gen_int_mode (size, Pmode);
448 get_dynamic_stack_size (&allocsize, 0, alignment_in_bits, NULL);
450 /* This is the size of space needed to accommodate required size of data
451 with given alignment. */
452 poly_int64 len = rtx_to_poly_int64 (allocsize);
453 old_frame_offset = frame_offset;
455 if (FRAME_GROWS_DOWNWARD)
457 frame_offset -= len;
458 try_fit_stack_local (frame_offset, len, len,
459 PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT,
460 &slot_offset);
462 else
464 frame_offset += len;
465 try_fit_stack_local (old_frame_offset, len, len,
466 PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT,
467 &slot_offset);
469 goto found_space;
471 else
473 if (crtl->stack_alignment_needed < alignment_in_bits)
474 crtl->stack_alignment_needed = alignment_in_bits;
475 if (crtl->max_used_stack_slot_alignment < alignment_in_bits)
476 crtl->max_used_stack_slot_alignment = alignment_in_bits;
479 if (mode != BLKmode || maybe_ne (size, 0))
481 if (kind & ASLK_RECORD_PAD)
483 struct frame_space **psp;
485 for (psp = &crtl->frame_space_list; *psp; psp = &(*psp)->next)
487 struct frame_space *space = *psp;
488 if (!try_fit_stack_local (space->start, space->length, size,
489 alignment, &slot_offset))
490 continue;
491 *psp = space->next;
492 if (known_gt (slot_offset, space->start))
493 add_frame_space (space->start, slot_offset);
494 if (known_lt (slot_offset + size, space->start + space->length))
495 add_frame_space (slot_offset + size,
496 space->start + space->length);
497 goto found_space;
501 else if (!STACK_ALIGNMENT_NEEDED)
503 slot_offset = frame_offset;
504 goto found_space;
507 old_frame_offset = frame_offset;
509 if (FRAME_GROWS_DOWNWARD)
511 frame_offset -= size;
512 try_fit_stack_local (frame_offset, size, size, alignment, &slot_offset);
514 if (kind & ASLK_RECORD_PAD)
516 if (known_gt (slot_offset, frame_offset))
517 add_frame_space (frame_offset, slot_offset);
518 if (known_lt (slot_offset + size, old_frame_offset))
519 add_frame_space (slot_offset + size, old_frame_offset);
522 else
524 frame_offset += size;
525 try_fit_stack_local (old_frame_offset, size, size, alignment, &slot_offset);
527 if (kind & ASLK_RECORD_PAD)
529 if (known_gt (slot_offset, old_frame_offset))
530 add_frame_space (old_frame_offset, slot_offset);
531 if (known_lt (slot_offset + size, frame_offset))
532 add_frame_space (slot_offset + size, frame_offset);
536 found_space:
537 /* On a big-endian machine, if we are allocating more space than we will use,
538 use the least significant bytes of those that are allocated. */
539 if (mode != BLKmode)
541 /* The slot size can sometimes be smaller than the mode size;
542 e.g. the rs6000 port allocates slots with a vector mode
543 that have the size of only one element. However, the slot
544 size must always be ordered wrt to the mode size, in the
545 same way as for a subreg. */
546 gcc_checking_assert (ordered_p (GET_MODE_SIZE (mode), size));
547 if (BYTES_BIG_ENDIAN && maybe_lt (GET_MODE_SIZE (mode), size))
548 bigend_correction = size - GET_MODE_SIZE (mode);
551 /* If we have already instantiated virtual registers, return the actual
552 address relative to the frame pointer. */
553 if (virtuals_instantiated)
554 addr = plus_constant (Pmode, frame_pointer_rtx,
555 trunc_int_for_mode
556 (slot_offset + bigend_correction
557 + targetm.starting_frame_offset (), Pmode));
558 else
559 addr = plus_constant (Pmode, virtual_stack_vars_rtx,
560 trunc_int_for_mode
561 (slot_offset + bigend_correction,
562 Pmode));
564 if (dynamic_align_addr)
566 addr = align_dynamic_address (addr, alignment_in_bits);
567 mark_reg_pointer (addr, alignment_in_bits);
570 x = gen_rtx_MEM (mode, addr);
571 set_mem_align (x, alignment_in_bits);
572 MEM_NOTRAP_P (x) = 1;
574 vec_safe_push (stack_slot_list, x);
576 if (frame_offset_overflow (frame_offset, current_function_decl))
577 frame_offset = 0;
579 return x;
582 /* Wrap up assign_stack_local_1 with last parameter as false. */
585 assign_stack_local (machine_mode mode, poly_int64 size, int align)
587 return assign_stack_local_1 (mode, size, align, ASLK_RECORD_PAD);
590 /* In order to evaluate some expressions, such as function calls returning
591 structures in memory, we need to temporarily allocate stack locations.
592 We record each allocated temporary in the following structure.
594 Associated with each temporary slot is a nesting level. When we pop up
595 one level, all temporaries associated with the previous level are freed.
596 Normally, all temporaries are freed after the execution of the statement
597 in which they were created. However, if we are inside a ({...}) grouping,
598 the result may be in a temporary and hence must be preserved. If the
599 result could be in a temporary, we preserve it if we can determine which
600 one it is in. If we cannot determine which temporary may contain the
601 result, all temporaries are preserved. A temporary is preserved by
602 pretending it was allocated at the previous nesting level. */
604 struct GTY(()) temp_slot {
605 /* Points to next temporary slot. */
606 struct temp_slot *next;
607 /* Points to previous temporary slot. */
608 struct temp_slot *prev;
609 /* The rtx to used to reference the slot. */
610 rtx slot;
611 /* The size, in units, of the slot. */
612 poly_int64 size;
613 /* The type of the object in the slot, or zero if it doesn't correspond
614 to a type. We use this to determine whether a slot can be reused.
615 It can be reused if objects of the type of the new slot will always
616 conflict with objects of the type of the old slot. */
617 tree type;
618 /* The alignment (in bits) of the slot. */
619 unsigned int align;
620 /* Nonzero if this temporary is currently in use. */
621 char in_use;
622 /* Nesting level at which this slot is being used. */
623 int level;
624 /* The offset of the slot from the frame_pointer, including extra space
625 for alignment. This info is for combine_temp_slots. */
626 poly_int64 base_offset;
627 /* The size of the slot, including extra space for alignment. This
628 info is for combine_temp_slots. */
629 poly_int64 full_size;
632 /* Entry for the below hash table. */
633 struct GTY((for_user)) temp_slot_address_entry {
634 hashval_t hash;
635 rtx address;
636 struct temp_slot *temp_slot;
639 struct temp_address_hasher : ggc_ptr_hash<temp_slot_address_entry>
641 static hashval_t hash (temp_slot_address_entry *);
642 static bool equal (temp_slot_address_entry *, temp_slot_address_entry *);
645 /* A table of addresses that represent a stack slot. The table is a mapping
646 from address RTXen to a temp slot. */
647 static GTY(()) hash_table<temp_address_hasher> *temp_slot_address_table;
648 static size_t n_temp_slots_in_use;
650 /* Removes temporary slot TEMP from LIST. */
652 static void
653 cut_slot_from_list (struct temp_slot *temp, struct temp_slot **list)
655 if (temp->next)
656 temp->next->prev = temp->prev;
657 if (temp->prev)
658 temp->prev->next = temp->next;
659 else
660 *list = temp->next;
662 temp->prev = temp->next = NULL;
665 /* Inserts temporary slot TEMP to LIST. */
667 static void
668 insert_slot_to_list (struct temp_slot *temp, struct temp_slot **list)
670 temp->next = *list;
671 if (*list)
672 (*list)->prev = temp;
673 temp->prev = NULL;
674 *list = temp;
677 /* Returns the list of used temp slots at LEVEL. */
679 static struct temp_slot **
680 temp_slots_at_level (int level)
682 if (level >= (int) vec_safe_length (used_temp_slots))
683 vec_safe_grow_cleared (used_temp_slots, level + 1);
685 return &(*used_temp_slots)[level];
688 /* Returns the maximal temporary slot level. */
690 static int
691 max_slot_level (void)
693 if (!used_temp_slots)
694 return -1;
696 return used_temp_slots->length () - 1;
699 /* Moves temporary slot TEMP to LEVEL. */
701 static void
702 move_slot_to_level (struct temp_slot *temp, int level)
704 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
705 insert_slot_to_list (temp, temp_slots_at_level (level));
706 temp->level = level;
709 /* Make temporary slot TEMP available. */
711 static void
712 make_slot_available (struct temp_slot *temp)
714 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
715 insert_slot_to_list (temp, &avail_temp_slots);
716 temp->in_use = 0;
717 temp->level = -1;
718 n_temp_slots_in_use--;
721 /* Compute the hash value for an address -> temp slot mapping.
722 The value is cached on the mapping entry. */
723 static hashval_t
724 temp_slot_address_compute_hash (struct temp_slot_address_entry *t)
726 int do_not_record = 0;
727 return hash_rtx (t->address, GET_MODE (t->address),
728 &do_not_record, NULL, false);
731 /* Return the hash value for an address -> temp slot mapping. */
732 hashval_t
733 temp_address_hasher::hash (temp_slot_address_entry *t)
735 return t->hash;
738 /* Compare two address -> temp slot mapping entries. */
739 bool
740 temp_address_hasher::equal (temp_slot_address_entry *t1,
741 temp_slot_address_entry *t2)
743 return exp_equiv_p (t1->address, t2->address, 0, true);
746 /* Add ADDRESS as an alias of TEMP_SLOT to the addess -> temp slot mapping. */
747 static void
748 insert_temp_slot_address (rtx address, struct temp_slot *temp_slot)
750 struct temp_slot_address_entry *t = ggc_alloc<temp_slot_address_entry> ();
751 t->address = address;
752 t->temp_slot = temp_slot;
753 t->hash = temp_slot_address_compute_hash (t);
754 *temp_slot_address_table->find_slot_with_hash (t, t->hash, INSERT) = t;
757 /* Remove an address -> temp slot mapping entry if the temp slot is
758 not in use anymore. Callback for remove_unused_temp_slot_addresses. */
760 remove_unused_temp_slot_addresses_1 (temp_slot_address_entry **slot, void *)
762 const struct temp_slot_address_entry *t = *slot;
763 if (! t->temp_slot->in_use)
764 temp_slot_address_table->clear_slot (slot);
765 return 1;
768 /* Remove all mappings of addresses to unused temp slots. */
769 static void
770 remove_unused_temp_slot_addresses (void)
772 /* Use quicker clearing if there aren't any active temp slots. */
773 if (n_temp_slots_in_use)
774 temp_slot_address_table->traverse
775 <void *, remove_unused_temp_slot_addresses_1> (NULL);
776 else
777 temp_slot_address_table->empty ();
780 /* Find the temp slot corresponding to the object at address X. */
782 static struct temp_slot *
783 find_temp_slot_from_address (rtx x)
785 struct temp_slot *p;
786 struct temp_slot_address_entry tmp, *t;
788 /* First try the easy way:
789 See if X exists in the address -> temp slot mapping. */
790 tmp.address = x;
791 tmp.temp_slot = NULL;
792 tmp.hash = temp_slot_address_compute_hash (&tmp);
793 t = temp_slot_address_table->find_with_hash (&tmp, tmp.hash);
794 if (t)
795 return t->temp_slot;
797 /* If we have a sum involving a register, see if it points to a temp
798 slot. */
799 if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 0))
800 && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
801 return p;
802 else if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 1))
803 && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
804 return p;
806 /* Last resort: Address is a virtual stack var address. */
807 poly_int64 offset;
808 if (strip_offset (x, &offset) == virtual_stack_vars_rtx)
810 int i;
811 for (i = max_slot_level (); i >= 0; i--)
812 for (p = *temp_slots_at_level (i); p; p = p->next)
813 if (known_in_range_p (offset, p->base_offset, p->full_size))
814 return p;
817 return NULL;
820 /* Allocate a temporary stack slot and record it for possible later
821 reuse.
823 MODE is the machine mode to be given to the returned rtx.
825 SIZE is the size in units of the space required. We do no rounding here
826 since assign_stack_local will do any required rounding.
828 TYPE is the type that will be used for the stack slot. */
831 assign_stack_temp_for_type (machine_mode mode, poly_int64 size, tree type)
833 unsigned int align;
834 struct temp_slot *p, *best_p = 0, *selected = NULL, **pp;
835 rtx slot;
837 gcc_assert (known_size_p (size));
839 align = get_stack_local_alignment (type, mode);
841 /* Try to find an available, already-allocated temporary of the proper
842 mode which meets the size and alignment requirements. Choose the
843 smallest one with the closest alignment.
845 If assign_stack_temp is called outside of the tree->rtl expansion,
846 we cannot reuse the stack slots (that may still refer to
847 VIRTUAL_STACK_VARS_REGNUM). */
848 if (!virtuals_instantiated)
850 for (p = avail_temp_slots; p; p = p->next)
852 if (p->align >= align
853 && known_ge (p->size, size)
854 && GET_MODE (p->slot) == mode
855 && objects_must_conflict_p (p->type, type)
856 && (best_p == 0
857 || (known_eq (best_p->size, p->size)
858 ? best_p->align > p->align
859 : known_ge (best_p->size, p->size))))
861 if (p->align == align && known_eq (p->size, size))
863 selected = p;
864 cut_slot_from_list (selected, &avail_temp_slots);
865 best_p = 0;
866 break;
868 best_p = p;
873 /* Make our best, if any, the one to use. */
874 if (best_p)
876 selected = best_p;
877 cut_slot_from_list (selected, &avail_temp_slots);
879 /* If there are enough aligned bytes left over, make them into a new
880 temp_slot so that the extra bytes don't get wasted. Do this only
881 for BLKmode slots, so that we can be sure of the alignment. */
882 if (GET_MODE (best_p->slot) == BLKmode)
884 int alignment = best_p->align / BITS_PER_UNIT;
885 poly_int64 rounded_size = aligned_upper_bound (size, alignment);
887 if (known_ge (best_p->size - rounded_size, alignment))
889 p = ggc_alloc<temp_slot> ();
890 p->in_use = 0;
891 p->size = best_p->size - rounded_size;
892 p->base_offset = best_p->base_offset + rounded_size;
893 p->full_size = best_p->full_size - rounded_size;
894 p->slot = adjust_address_nv (best_p->slot, BLKmode, rounded_size);
895 p->align = best_p->align;
896 p->type = best_p->type;
897 insert_slot_to_list (p, &avail_temp_slots);
899 vec_safe_push (stack_slot_list, p->slot);
901 best_p->size = rounded_size;
902 best_p->full_size = rounded_size;
907 /* If we still didn't find one, make a new temporary. */
908 if (selected == 0)
910 poly_int64 frame_offset_old = frame_offset;
912 p = ggc_alloc<temp_slot> ();
914 /* We are passing an explicit alignment request to assign_stack_local.
915 One side effect of that is assign_stack_local will not round SIZE
916 to ensure the frame offset remains suitably aligned.
918 So for requests which depended on the rounding of SIZE, we go ahead
919 and round it now. We also make sure ALIGNMENT is at least
920 BIGGEST_ALIGNMENT. */
921 gcc_assert (mode != BLKmode || align == BIGGEST_ALIGNMENT);
922 p->slot = assign_stack_local_1 (mode,
923 (mode == BLKmode
924 ? aligned_upper_bound (size,
925 (int) align
926 / BITS_PER_UNIT)
927 : size),
928 align, 0);
930 p->align = align;
932 /* The following slot size computation is necessary because we don't
933 know the actual size of the temporary slot until assign_stack_local
934 has performed all the frame alignment and size rounding for the
935 requested temporary. Note that extra space added for alignment
936 can be either above or below this stack slot depending on which
937 way the frame grows. We include the extra space if and only if it
938 is above this slot. */
939 if (FRAME_GROWS_DOWNWARD)
940 p->size = frame_offset_old - frame_offset;
941 else
942 p->size = size;
944 /* Now define the fields used by combine_temp_slots. */
945 if (FRAME_GROWS_DOWNWARD)
947 p->base_offset = frame_offset;
948 p->full_size = frame_offset_old - frame_offset;
950 else
952 p->base_offset = frame_offset_old;
953 p->full_size = frame_offset - frame_offset_old;
956 selected = p;
959 p = selected;
960 p->in_use = 1;
961 p->type = type;
962 p->level = temp_slot_level;
963 n_temp_slots_in_use++;
965 pp = temp_slots_at_level (p->level);
966 insert_slot_to_list (p, pp);
967 insert_temp_slot_address (XEXP (p->slot, 0), p);
969 /* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
970 slot = gen_rtx_MEM (mode, XEXP (p->slot, 0));
971 vec_safe_push (stack_slot_list, slot);
973 /* If we know the alias set for the memory that will be used, use
974 it. If there's no TYPE, then we don't know anything about the
975 alias set for the memory. */
976 set_mem_alias_set (slot, type ? get_alias_set (type) : 0);
977 set_mem_align (slot, align);
979 /* If a type is specified, set the relevant flags. */
980 if (type != 0)
981 MEM_VOLATILE_P (slot) = TYPE_VOLATILE (type);
982 MEM_NOTRAP_P (slot) = 1;
984 return slot;
987 /* Allocate a temporary stack slot and record it for possible later
988 reuse. First two arguments are same as in preceding function. */
991 assign_stack_temp (machine_mode mode, poly_int64 size)
993 return assign_stack_temp_for_type (mode, size, NULL_TREE);
996 /* Assign a temporary.
997 If TYPE_OR_DECL is a decl, then we are doing it on behalf of the decl
998 and so that should be used in error messages. In either case, we
999 allocate of the given type.
1000 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
1001 it is 0 if a register is OK.
1002 DONT_PROMOTE is 1 if we should not promote values in register
1003 to wider modes. */
1006 assign_temp (tree type_or_decl, int memory_required,
1007 int dont_promote ATTRIBUTE_UNUSED)
1009 tree type, decl;
1010 machine_mode mode;
1011 #ifdef PROMOTE_MODE
1012 int unsignedp;
1013 #endif
1015 if (DECL_P (type_or_decl))
1016 decl = type_or_decl, type = TREE_TYPE (decl);
1017 else
1018 decl = NULL, type = type_or_decl;
1020 mode = TYPE_MODE (type);
1021 #ifdef PROMOTE_MODE
1022 unsignedp = TYPE_UNSIGNED (type);
1023 #endif
1025 /* Allocating temporaries of TREE_ADDRESSABLE type must be done in the front
1026 end. See also create_tmp_var for the gimplification-time check. */
1027 gcc_assert (!TREE_ADDRESSABLE (type) && COMPLETE_TYPE_P (type));
1029 if (mode == BLKmode || memory_required)
1031 poly_int64 size;
1032 rtx tmp;
1034 /* Unfortunately, we don't yet know how to allocate variable-sized
1035 temporaries. However, sometimes we can find a fixed upper limit on
1036 the size, so try that instead. */
1037 if (!poly_int_tree_p (TYPE_SIZE_UNIT (type), &size))
1038 size = max_int_size_in_bytes (type);
1040 /* Zero sized arrays are a GNU C extension. Set size to 1 to avoid
1041 problems with allocating the stack space. */
1042 if (known_eq (size, 0))
1043 size = 1;
1045 /* The size of the temporary may be too large to fit into an integer. */
1046 /* ??? Not sure this should happen except for user silliness, so limit
1047 this to things that aren't compiler-generated temporaries. The
1048 rest of the time we'll die in assign_stack_temp_for_type. */
1049 if (decl
1050 && !known_size_p (size)
1051 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST)
1053 error ("size of variable %q+D is too large", decl);
1054 size = 1;
1057 tmp = assign_stack_temp_for_type (mode, size, type);
1058 return tmp;
1061 #ifdef PROMOTE_MODE
1062 if (! dont_promote)
1063 mode = promote_mode (type, mode, &unsignedp);
1064 #endif
1066 return gen_reg_rtx (mode);
1069 /* Combine temporary stack slots which are adjacent on the stack.
1071 This allows for better use of already allocated stack space. This is only
1072 done for BLKmode slots because we can be sure that we won't have alignment
1073 problems in this case. */
1075 static void
1076 combine_temp_slots (void)
1078 struct temp_slot *p, *q, *next, *next_q;
1079 int num_slots;
1081 /* We can't combine slots, because the information about which slot
1082 is in which alias set will be lost. */
1083 if (flag_strict_aliasing)
1084 return;
1086 /* If there are a lot of temp slots, don't do anything unless
1087 high levels of optimization. */
1088 if (! flag_expensive_optimizations)
1089 for (p = avail_temp_slots, num_slots = 0; p; p = p->next, num_slots++)
1090 if (num_slots > 100 || (num_slots > 10 && optimize == 0))
1091 return;
1093 for (p = avail_temp_slots; p; p = next)
1095 int delete_p = 0;
1097 next = p->next;
1099 if (GET_MODE (p->slot) != BLKmode)
1100 continue;
1102 for (q = p->next; q; q = next_q)
1104 int delete_q = 0;
1106 next_q = q->next;
1108 if (GET_MODE (q->slot) != BLKmode)
1109 continue;
1111 if (known_eq (p->base_offset + p->full_size, q->base_offset))
1113 /* Q comes after P; combine Q into P. */
1114 p->size += q->size;
1115 p->full_size += q->full_size;
1116 delete_q = 1;
1118 else if (known_eq (q->base_offset + q->full_size, p->base_offset))
1120 /* P comes after Q; combine P into Q. */
1121 q->size += p->size;
1122 q->full_size += p->full_size;
1123 delete_p = 1;
1124 break;
1126 if (delete_q)
1127 cut_slot_from_list (q, &avail_temp_slots);
1130 /* Either delete P or advance past it. */
1131 if (delete_p)
1132 cut_slot_from_list (p, &avail_temp_slots);
1136 /* Indicate that NEW_RTX is an alternate way of referring to the temp
1137 slot that previously was known by OLD_RTX. */
1139 void
1140 update_temp_slot_address (rtx old_rtx, rtx new_rtx)
1142 struct temp_slot *p;
1144 if (rtx_equal_p (old_rtx, new_rtx))
1145 return;
1147 p = find_temp_slot_from_address (old_rtx);
1149 /* If we didn't find one, see if both OLD_RTX is a PLUS. If so, and
1150 NEW_RTX is a register, see if one operand of the PLUS is a
1151 temporary location. If so, NEW_RTX points into it. Otherwise,
1152 if both OLD_RTX and NEW_RTX are a PLUS and if there is a register
1153 in common between them. If so, try a recursive call on those
1154 values. */
1155 if (p == 0)
1157 if (GET_CODE (old_rtx) != PLUS)
1158 return;
1160 if (REG_P (new_rtx))
1162 update_temp_slot_address (XEXP (old_rtx, 0), new_rtx);
1163 update_temp_slot_address (XEXP (old_rtx, 1), new_rtx);
1164 return;
1166 else if (GET_CODE (new_rtx) != PLUS)
1167 return;
1169 if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 0)))
1170 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 1));
1171 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 0)))
1172 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 1));
1173 else if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 1)))
1174 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 0));
1175 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 1)))
1176 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 0));
1178 return;
1181 /* Otherwise add an alias for the temp's address. */
1182 insert_temp_slot_address (new_rtx, p);
1185 /* If X could be a reference to a temporary slot, mark that slot as
1186 belonging to the to one level higher than the current level. If X
1187 matched one of our slots, just mark that one. Otherwise, we can't
1188 easily predict which it is, so upgrade all of them.
1190 This is called when an ({...}) construct occurs and a statement
1191 returns a value in memory. */
1193 void
1194 preserve_temp_slots (rtx x)
1196 struct temp_slot *p = 0, *next;
1198 if (x == 0)
1199 return;
1201 /* If X is a register that is being used as a pointer, see if we have
1202 a temporary slot we know it points to. */
1203 if (REG_P (x) && REG_POINTER (x))
1204 p = find_temp_slot_from_address (x);
1206 /* If X is not in memory or is at a constant address, it cannot be in
1207 a temporary slot. */
1208 if (p == 0 && (!MEM_P (x) || CONSTANT_P (XEXP (x, 0))))
1209 return;
1211 /* First see if we can find a match. */
1212 if (p == 0)
1213 p = find_temp_slot_from_address (XEXP (x, 0));
1215 if (p != 0)
1217 if (p->level == temp_slot_level)
1218 move_slot_to_level (p, temp_slot_level - 1);
1219 return;
1222 /* Otherwise, preserve all non-kept slots at this level. */
1223 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1225 next = p->next;
1226 move_slot_to_level (p, temp_slot_level - 1);
1230 /* Free all temporaries used so far. This is normally called at the
1231 end of generating code for a statement. */
1233 void
1234 free_temp_slots (void)
1236 struct temp_slot *p, *next;
1237 bool some_available = false;
1239 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1241 next = p->next;
1242 make_slot_available (p);
1243 some_available = true;
1246 if (some_available)
1248 remove_unused_temp_slot_addresses ();
1249 combine_temp_slots ();
1253 /* Push deeper into the nesting level for stack temporaries. */
1255 void
1256 push_temp_slots (void)
1258 temp_slot_level++;
1261 /* Pop a temporary nesting level. All slots in use in the current level
1262 are freed. */
1264 void
1265 pop_temp_slots (void)
1267 free_temp_slots ();
1268 temp_slot_level--;
1271 /* Initialize temporary slots. */
1273 void
1274 init_temp_slots (void)
1276 /* We have not allocated any temporaries yet. */
1277 avail_temp_slots = 0;
1278 vec_alloc (used_temp_slots, 0);
1279 temp_slot_level = 0;
1280 n_temp_slots_in_use = 0;
1282 /* Set up the table to map addresses to temp slots. */
1283 if (! temp_slot_address_table)
1284 temp_slot_address_table = hash_table<temp_address_hasher>::create_ggc (32);
1285 else
1286 temp_slot_address_table->empty ();
1289 /* Functions and data structures to keep track of the values hard regs
1290 had at the start of the function. */
1292 /* Private type used by get_hard_reg_initial_reg, get_hard_reg_initial_val,
1293 and has_hard_reg_initial_val.. */
1294 struct GTY(()) initial_value_pair {
1295 rtx hard_reg;
1296 rtx pseudo;
1298 /* ??? This could be a VEC but there is currently no way to define an
1299 opaque VEC type. This could be worked around by defining struct
1300 initial_value_pair in function.h. */
1301 struct GTY(()) initial_value_struct {
1302 int num_entries;
1303 int max_entries;
1304 initial_value_pair * GTY ((length ("%h.num_entries"))) entries;
1307 /* If a pseudo represents an initial hard reg (or expression), return
1308 it, else return NULL_RTX. */
1311 get_hard_reg_initial_reg (rtx reg)
1313 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1314 int i;
1316 if (ivs == 0)
1317 return NULL_RTX;
1319 for (i = 0; i < ivs->num_entries; i++)
1320 if (rtx_equal_p (ivs->entries[i].pseudo, reg))
1321 return ivs->entries[i].hard_reg;
1323 return NULL_RTX;
1326 /* Make sure that there's a pseudo register of mode MODE that stores the
1327 initial value of hard register REGNO. Return an rtx for such a pseudo. */
1330 get_hard_reg_initial_val (machine_mode mode, unsigned int regno)
1332 struct initial_value_struct *ivs;
1333 rtx rv;
1335 rv = has_hard_reg_initial_val (mode, regno);
1336 if (rv)
1337 return rv;
1339 ivs = crtl->hard_reg_initial_vals;
1340 if (ivs == 0)
1342 ivs = ggc_alloc<initial_value_struct> ();
1343 ivs->num_entries = 0;
1344 ivs->max_entries = 5;
1345 ivs->entries = ggc_vec_alloc<initial_value_pair> (5);
1346 crtl->hard_reg_initial_vals = ivs;
1349 if (ivs->num_entries >= ivs->max_entries)
1351 ivs->max_entries += 5;
1352 ivs->entries = GGC_RESIZEVEC (initial_value_pair, ivs->entries,
1353 ivs->max_entries);
1356 ivs->entries[ivs->num_entries].hard_reg = gen_rtx_REG (mode, regno);
1357 ivs->entries[ivs->num_entries].pseudo = gen_reg_rtx (mode);
1359 return ivs->entries[ivs->num_entries++].pseudo;
1362 /* See if get_hard_reg_initial_val has been used to create a pseudo
1363 for the initial value of hard register REGNO in mode MODE. Return
1364 the associated pseudo if so, otherwise return NULL. */
1367 has_hard_reg_initial_val (machine_mode mode, unsigned int regno)
1369 struct initial_value_struct *ivs;
1370 int i;
1372 ivs = crtl->hard_reg_initial_vals;
1373 if (ivs != 0)
1374 for (i = 0; i < ivs->num_entries; i++)
1375 if (GET_MODE (ivs->entries[i].hard_reg) == mode
1376 && REGNO (ivs->entries[i].hard_reg) == regno)
1377 return ivs->entries[i].pseudo;
1379 return NULL_RTX;
1382 unsigned int
1383 emit_initial_value_sets (void)
1385 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1386 int i;
1387 rtx_insn *seq;
1389 if (ivs == 0)
1390 return 0;
1392 start_sequence ();
1393 for (i = 0; i < ivs->num_entries; i++)
1394 emit_move_insn (ivs->entries[i].pseudo, ivs->entries[i].hard_reg);
1395 seq = get_insns ();
1396 end_sequence ();
1398 emit_insn_at_entry (seq);
1399 return 0;
1402 /* Return the hardreg-pseudoreg initial values pair entry I and
1403 TRUE if I is a valid entry, or FALSE if I is not a valid entry. */
1404 bool
1405 initial_value_entry (int i, rtx *hreg, rtx *preg)
1407 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1408 if (!ivs || i >= ivs->num_entries)
1409 return false;
1411 *hreg = ivs->entries[i].hard_reg;
1412 *preg = ivs->entries[i].pseudo;
1413 return true;
1416 /* These routines are responsible for converting virtual register references
1417 to the actual hard register references once RTL generation is complete.
1419 The following four variables are used for communication between the
1420 routines. They contain the offsets of the virtual registers from their
1421 respective hard registers. */
1423 static poly_int64 in_arg_offset;
1424 static poly_int64 var_offset;
1425 static poly_int64 dynamic_offset;
1426 static poly_int64 out_arg_offset;
1427 static poly_int64 cfa_offset;
1429 /* In most machines, the stack pointer register is equivalent to the bottom
1430 of the stack. */
1432 #ifndef STACK_POINTER_OFFSET
1433 #define STACK_POINTER_OFFSET 0
1434 #endif
1436 #if defined (REG_PARM_STACK_SPACE) && !defined (INCOMING_REG_PARM_STACK_SPACE)
1437 #define INCOMING_REG_PARM_STACK_SPACE REG_PARM_STACK_SPACE
1438 #endif
1440 /* If not defined, pick an appropriate default for the offset of dynamically
1441 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
1442 INCOMING_REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
1444 #ifndef STACK_DYNAMIC_OFFSET
1446 /* The bottom of the stack points to the actual arguments. If
1447 REG_PARM_STACK_SPACE is defined, this includes the space for the register
1448 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
1449 stack space for register parameters is not pushed by the caller, but
1450 rather part of the fixed stack areas and hence not included in
1451 `crtl->outgoing_args_size'. Nevertheless, we must allow
1452 for it when allocating stack dynamic objects. */
1454 #ifdef INCOMING_REG_PARM_STACK_SPACE
1455 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1456 ((ACCUMULATE_OUTGOING_ARGS \
1457 ? (crtl->outgoing_args_size \
1458 + (OUTGOING_REG_PARM_STACK_SPACE ((!(FNDECL) ? NULL_TREE : TREE_TYPE (FNDECL))) ? 0 \
1459 : INCOMING_REG_PARM_STACK_SPACE (FNDECL))) \
1460 : 0) + (STACK_POINTER_OFFSET))
1461 #else
1462 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1463 ((ACCUMULATE_OUTGOING_ARGS ? crtl->outgoing_args_size : poly_int64 (0)) \
1464 + (STACK_POINTER_OFFSET))
1465 #endif
1466 #endif
1469 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
1470 is a virtual register, return the equivalent hard register and set the
1471 offset indirectly through the pointer. Otherwise, return 0. */
1473 static rtx
1474 instantiate_new_reg (rtx x, poly_int64_pod *poffset)
1476 rtx new_rtx;
1477 poly_int64 offset;
1479 if (x == virtual_incoming_args_rtx)
1481 if (stack_realign_drap)
1483 /* Replace virtual_incoming_args_rtx with internal arg
1484 pointer if DRAP is used to realign stack. */
1485 new_rtx = crtl->args.internal_arg_pointer;
1486 offset = 0;
1488 else
1489 new_rtx = arg_pointer_rtx, offset = in_arg_offset;
1491 else if (x == virtual_stack_vars_rtx)
1492 new_rtx = frame_pointer_rtx, offset = var_offset;
1493 else if (x == virtual_stack_dynamic_rtx)
1494 new_rtx = stack_pointer_rtx, offset = dynamic_offset;
1495 else if (x == virtual_outgoing_args_rtx)
1496 new_rtx = stack_pointer_rtx, offset = out_arg_offset;
1497 else if (x == virtual_cfa_rtx)
1499 #ifdef FRAME_POINTER_CFA_OFFSET
1500 new_rtx = frame_pointer_rtx;
1501 #else
1502 new_rtx = arg_pointer_rtx;
1503 #endif
1504 offset = cfa_offset;
1506 else if (x == virtual_preferred_stack_boundary_rtx)
1508 new_rtx = GEN_INT (crtl->preferred_stack_boundary / BITS_PER_UNIT);
1509 offset = 0;
1511 else
1512 return NULL_RTX;
1514 *poffset = offset;
1515 return new_rtx;
1518 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1519 registers present inside of *LOC. The expression is simplified,
1520 as much as possible, but is not to be considered "valid" in any sense
1521 implied by the target. Return true if any change is made. */
1523 static bool
1524 instantiate_virtual_regs_in_rtx (rtx *loc)
1526 if (!*loc)
1527 return false;
1528 bool changed = false;
1529 subrtx_ptr_iterator::array_type array;
1530 FOR_EACH_SUBRTX_PTR (iter, array, loc, NONCONST)
1532 rtx *loc = *iter;
1533 if (rtx x = *loc)
1535 rtx new_rtx;
1536 poly_int64 offset;
1537 switch (GET_CODE (x))
1539 case REG:
1540 new_rtx = instantiate_new_reg (x, &offset);
1541 if (new_rtx)
1543 *loc = plus_constant (GET_MODE (x), new_rtx, offset);
1544 changed = true;
1546 iter.skip_subrtxes ();
1547 break;
1549 case PLUS:
1550 new_rtx = instantiate_new_reg (XEXP (x, 0), &offset);
1551 if (new_rtx)
1553 XEXP (x, 0) = new_rtx;
1554 *loc = plus_constant (GET_MODE (x), x, offset, true);
1555 changed = true;
1556 iter.skip_subrtxes ();
1557 break;
1560 /* FIXME -- from old code */
1561 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
1562 we can commute the PLUS and SUBREG because pointers into the
1563 frame are well-behaved. */
1564 break;
1566 default:
1567 break;
1571 return changed;
1574 /* A subroutine of instantiate_virtual_regs_in_insn. Return true if X
1575 matches the predicate for insn CODE operand OPERAND. */
1577 static int
1578 safe_insn_predicate (int code, int operand, rtx x)
1580 return code < 0 || insn_operand_matches ((enum insn_code) code, operand, x);
1583 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1584 registers present inside of insn. The result will be a valid insn. */
1586 static void
1587 instantiate_virtual_regs_in_insn (rtx_insn *insn)
1589 poly_int64 offset;
1590 int insn_code, i;
1591 bool any_change = false;
1592 rtx set, new_rtx, x;
1593 rtx_insn *seq;
1595 /* There are some special cases to be handled first. */
1596 set = single_set (insn);
1597 if (set)
1599 /* We're allowed to assign to a virtual register. This is interpreted
1600 to mean that the underlying register gets assigned the inverse
1601 transformation. This is used, for example, in the handling of
1602 non-local gotos. */
1603 new_rtx = instantiate_new_reg (SET_DEST (set), &offset);
1604 if (new_rtx)
1606 start_sequence ();
1608 instantiate_virtual_regs_in_rtx (&SET_SRC (set));
1609 x = simplify_gen_binary (PLUS, GET_MODE (new_rtx), SET_SRC (set),
1610 gen_int_mode (-offset, GET_MODE (new_rtx)));
1611 x = force_operand (x, new_rtx);
1612 if (x != new_rtx)
1613 emit_move_insn (new_rtx, x);
1615 seq = get_insns ();
1616 end_sequence ();
1618 emit_insn_before (seq, insn);
1619 delete_insn (insn);
1620 return;
1623 /* Handle a straight copy from a virtual register by generating a
1624 new add insn. The difference between this and falling through
1625 to the generic case is avoiding a new pseudo and eliminating a
1626 move insn in the initial rtl stream. */
1627 new_rtx = instantiate_new_reg (SET_SRC (set), &offset);
1628 if (new_rtx
1629 && maybe_ne (offset, 0)
1630 && REG_P (SET_DEST (set))
1631 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1633 start_sequence ();
1635 x = expand_simple_binop (GET_MODE (SET_DEST (set)), PLUS, new_rtx,
1636 gen_int_mode (offset,
1637 GET_MODE (SET_DEST (set))),
1638 SET_DEST (set), 1, OPTAB_LIB_WIDEN);
1639 if (x != SET_DEST (set))
1640 emit_move_insn (SET_DEST (set), x);
1642 seq = get_insns ();
1643 end_sequence ();
1645 emit_insn_before (seq, insn);
1646 delete_insn (insn);
1647 return;
1650 extract_insn (insn);
1651 insn_code = INSN_CODE (insn);
1653 /* Handle a plus involving a virtual register by determining if the
1654 operands remain valid if they're modified in place. */
1655 poly_int64 delta;
1656 if (GET_CODE (SET_SRC (set)) == PLUS
1657 && recog_data.n_operands >= 3
1658 && recog_data.operand_loc[1] == &XEXP (SET_SRC (set), 0)
1659 && recog_data.operand_loc[2] == &XEXP (SET_SRC (set), 1)
1660 && poly_int_rtx_p (recog_data.operand[2], &delta)
1661 && (new_rtx = instantiate_new_reg (recog_data.operand[1], &offset)))
1663 offset += delta;
1665 /* If the sum is zero, then replace with a plain move. */
1666 if (known_eq (offset, 0)
1667 && REG_P (SET_DEST (set))
1668 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1670 start_sequence ();
1671 emit_move_insn (SET_DEST (set), new_rtx);
1672 seq = get_insns ();
1673 end_sequence ();
1675 emit_insn_before (seq, insn);
1676 delete_insn (insn);
1677 return;
1680 x = gen_int_mode (offset, recog_data.operand_mode[2]);
1682 /* Using validate_change and apply_change_group here leaves
1683 recog_data in an invalid state. Since we know exactly what
1684 we want to check, do those two by hand. */
1685 if (safe_insn_predicate (insn_code, 1, new_rtx)
1686 && safe_insn_predicate (insn_code, 2, x))
1688 *recog_data.operand_loc[1] = recog_data.operand[1] = new_rtx;
1689 *recog_data.operand_loc[2] = recog_data.operand[2] = x;
1690 any_change = true;
1692 /* Fall through into the regular operand fixup loop in
1693 order to take care of operands other than 1 and 2. */
1697 else
1699 extract_insn (insn);
1700 insn_code = INSN_CODE (insn);
1703 /* In the general case, we expect virtual registers to appear only in
1704 operands, and then only as either bare registers or inside memories. */
1705 for (i = 0; i < recog_data.n_operands; ++i)
1707 x = recog_data.operand[i];
1708 switch (GET_CODE (x))
1710 case MEM:
1712 rtx addr = XEXP (x, 0);
1714 if (!instantiate_virtual_regs_in_rtx (&addr))
1715 continue;
1717 start_sequence ();
1718 x = replace_equiv_address (x, addr, true);
1719 /* It may happen that the address with the virtual reg
1720 was valid (e.g. based on the virtual stack reg, which might
1721 be acceptable to the predicates with all offsets), whereas
1722 the address now isn't anymore, for instance when the address
1723 is still offsetted, but the base reg isn't virtual-stack-reg
1724 anymore. Below we would do a force_reg on the whole operand,
1725 but this insn might actually only accept memory. Hence,
1726 before doing that last resort, try to reload the address into
1727 a register, so this operand stays a MEM. */
1728 if (!safe_insn_predicate (insn_code, i, x))
1730 addr = force_reg (GET_MODE (addr), addr);
1731 x = replace_equiv_address (x, addr, true);
1733 seq = get_insns ();
1734 end_sequence ();
1735 if (seq)
1736 emit_insn_before (seq, insn);
1738 break;
1740 case REG:
1741 new_rtx = instantiate_new_reg (x, &offset);
1742 if (new_rtx == NULL)
1743 continue;
1744 if (known_eq (offset, 0))
1745 x = new_rtx;
1746 else
1748 start_sequence ();
1750 /* Careful, special mode predicates may have stuff in
1751 insn_data[insn_code].operand[i].mode that isn't useful
1752 to us for computing a new value. */
1753 /* ??? Recognize address_operand and/or "p" constraints
1754 to see if (plus new offset) is a valid before we put
1755 this through expand_simple_binop. */
1756 x = expand_simple_binop (GET_MODE (x), PLUS, new_rtx,
1757 gen_int_mode (offset, GET_MODE (x)),
1758 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1759 seq = get_insns ();
1760 end_sequence ();
1761 emit_insn_before (seq, insn);
1763 break;
1765 case SUBREG:
1766 new_rtx = instantiate_new_reg (SUBREG_REG (x), &offset);
1767 if (new_rtx == NULL)
1768 continue;
1769 if (maybe_ne (offset, 0))
1771 start_sequence ();
1772 new_rtx = expand_simple_binop
1773 (GET_MODE (new_rtx), PLUS, new_rtx,
1774 gen_int_mode (offset, GET_MODE (new_rtx)),
1775 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1776 seq = get_insns ();
1777 end_sequence ();
1778 emit_insn_before (seq, insn);
1780 x = simplify_gen_subreg (recog_data.operand_mode[i], new_rtx,
1781 GET_MODE (new_rtx), SUBREG_BYTE (x));
1782 gcc_assert (x);
1783 break;
1785 default:
1786 continue;
1789 /* At this point, X contains the new value for the operand.
1790 Validate the new value vs the insn predicate. Note that
1791 asm insns will have insn_code -1 here. */
1792 if (!safe_insn_predicate (insn_code, i, x))
1794 start_sequence ();
1795 if (REG_P (x))
1797 gcc_assert (REGNO (x) <= LAST_VIRTUAL_REGISTER);
1798 x = copy_to_reg (x);
1800 else
1801 x = force_reg (insn_data[insn_code].operand[i].mode, x);
1802 seq = get_insns ();
1803 end_sequence ();
1804 if (seq)
1805 emit_insn_before (seq, insn);
1808 *recog_data.operand_loc[i] = recog_data.operand[i] = x;
1809 any_change = true;
1812 if (any_change)
1814 /* Propagate operand changes into the duplicates. */
1815 for (i = 0; i < recog_data.n_dups; ++i)
1816 *recog_data.dup_loc[i]
1817 = copy_rtx (recog_data.operand[(unsigned)recog_data.dup_num[i]]);
1819 /* Force re-recognition of the instruction for validation. */
1820 INSN_CODE (insn) = -1;
1823 if (asm_noperands (PATTERN (insn)) >= 0)
1825 if (!check_asm_operands (PATTERN (insn)))
1827 error_for_asm (insn, "impossible constraint in %<asm%>");
1828 /* For asm goto, instead of fixing up all the edges
1829 just clear the template and clear input operands
1830 (asm goto doesn't have any output operands). */
1831 if (JUMP_P (insn))
1833 rtx asm_op = extract_asm_operands (PATTERN (insn));
1834 ASM_OPERANDS_TEMPLATE (asm_op) = ggc_strdup ("");
1835 ASM_OPERANDS_INPUT_VEC (asm_op) = rtvec_alloc (0);
1836 ASM_OPERANDS_INPUT_CONSTRAINT_VEC (asm_op) = rtvec_alloc (0);
1838 else
1839 delete_insn (insn);
1842 else
1844 if (recog_memoized (insn) < 0)
1845 fatal_insn_not_found (insn);
1849 /* Subroutine of instantiate_decls. Given RTL representing a decl,
1850 do any instantiation required. */
1852 void
1853 instantiate_decl_rtl (rtx x)
1855 rtx addr;
1857 if (x == 0)
1858 return;
1860 /* If this is a CONCAT, recurse for the pieces. */
1861 if (GET_CODE (x) == CONCAT)
1863 instantiate_decl_rtl (XEXP (x, 0));
1864 instantiate_decl_rtl (XEXP (x, 1));
1865 return;
1868 /* If this is not a MEM, no need to do anything. Similarly if the
1869 address is a constant or a register that is not a virtual register. */
1870 if (!MEM_P (x))
1871 return;
1873 addr = XEXP (x, 0);
1874 if (CONSTANT_P (addr)
1875 || (REG_P (addr)
1876 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
1877 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
1878 return;
1880 instantiate_virtual_regs_in_rtx (&XEXP (x, 0));
1883 /* Helper for instantiate_decls called via walk_tree: Process all decls
1884 in the given DECL_VALUE_EXPR. */
1886 static tree
1887 instantiate_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1889 tree t = *tp;
1890 if (! EXPR_P (t))
1892 *walk_subtrees = 0;
1893 if (DECL_P (t))
1895 if (DECL_RTL_SET_P (t))
1896 instantiate_decl_rtl (DECL_RTL (t));
1897 if (TREE_CODE (t) == PARM_DECL && DECL_NAMELESS (t)
1898 && DECL_INCOMING_RTL (t))
1899 instantiate_decl_rtl (DECL_INCOMING_RTL (t));
1900 if ((VAR_P (t) || TREE_CODE (t) == RESULT_DECL)
1901 && DECL_HAS_VALUE_EXPR_P (t))
1903 tree v = DECL_VALUE_EXPR (t);
1904 walk_tree (&v, instantiate_expr, NULL, NULL);
1908 return NULL;
1911 /* Subroutine of instantiate_decls: Process all decls in the given
1912 BLOCK node and all its subblocks. */
1914 static void
1915 instantiate_decls_1 (tree let)
1917 tree t;
1919 for (t = BLOCK_VARS (let); t; t = DECL_CHAIN (t))
1921 if (DECL_RTL_SET_P (t))
1922 instantiate_decl_rtl (DECL_RTL (t));
1923 if (VAR_P (t) && DECL_HAS_VALUE_EXPR_P (t))
1925 tree v = DECL_VALUE_EXPR (t);
1926 walk_tree (&v, instantiate_expr, NULL, NULL);
1930 /* Process all subblocks. */
1931 for (t = BLOCK_SUBBLOCKS (let); t; t = BLOCK_CHAIN (t))
1932 instantiate_decls_1 (t);
1935 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1936 all virtual registers in their DECL_RTL's. */
1938 static void
1939 instantiate_decls (tree fndecl)
1941 tree decl;
1942 unsigned ix;
1944 /* Process all parameters of the function. */
1945 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = DECL_CHAIN (decl))
1947 instantiate_decl_rtl (DECL_RTL (decl));
1948 instantiate_decl_rtl (DECL_INCOMING_RTL (decl));
1949 if (DECL_HAS_VALUE_EXPR_P (decl))
1951 tree v = DECL_VALUE_EXPR (decl);
1952 walk_tree (&v, instantiate_expr, NULL, NULL);
1956 if ((decl = DECL_RESULT (fndecl))
1957 && TREE_CODE (decl) == RESULT_DECL)
1959 if (DECL_RTL_SET_P (decl))
1960 instantiate_decl_rtl (DECL_RTL (decl));
1961 if (DECL_HAS_VALUE_EXPR_P (decl))
1963 tree v = DECL_VALUE_EXPR (decl);
1964 walk_tree (&v, instantiate_expr, NULL, NULL);
1968 /* Process the saved static chain if it exists. */
1969 decl = DECL_STRUCT_FUNCTION (fndecl)->static_chain_decl;
1970 if (decl && DECL_HAS_VALUE_EXPR_P (decl))
1971 instantiate_decl_rtl (DECL_RTL (DECL_VALUE_EXPR (decl)));
1973 /* Now process all variables defined in the function or its subblocks. */
1974 if (DECL_INITIAL (fndecl))
1975 instantiate_decls_1 (DECL_INITIAL (fndecl));
1977 FOR_EACH_LOCAL_DECL (cfun, ix, decl)
1978 if (DECL_RTL_SET_P (decl))
1979 instantiate_decl_rtl (DECL_RTL (decl));
1980 vec_free (cfun->local_decls);
1983 /* Pass through the INSNS of function FNDECL and convert virtual register
1984 references to hard register references. */
1986 static unsigned int
1987 instantiate_virtual_regs (void)
1989 rtx_insn *insn;
1991 /* Compute the offsets to use for this function. */
1992 in_arg_offset = FIRST_PARM_OFFSET (current_function_decl);
1993 var_offset = targetm.starting_frame_offset ();
1994 dynamic_offset = STACK_DYNAMIC_OFFSET (current_function_decl);
1995 out_arg_offset = STACK_POINTER_OFFSET;
1996 #ifdef FRAME_POINTER_CFA_OFFSET
1997 cfa_offset = FRAME_POINTER_CFA_OFFSET (current_function_decl);
1998 #else
1999 cfa_offset = ARG_POINTER_CFA_OFFSET (current_function_decl);
2000 #endif
2002 /* Initialize recognition, indicating that volatile is OK. */
2003 init_recog ();
2005 /* Scan through all the insns, instantiating every virtual register still
2006 present. */
2007 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
2008 if (INSN_P (insn))
2010 /* These patterns in the instruction stream can never be recognized.
2011 Fortunately, they shouldn't contain virtual registers either. */
2012 if (GET_CODE (PATTERN (insn)) == USE
2013 || GET_CODE (PATTERN (insn)) == CLOBBER
2014 || GET_CODE (PATTERN (insn)) == ASM_INPUT
2015 || DEBUG_MARKER_INSN_P (insn))
2016 continue;
2017 else if (DEBUG_BIND_INSN_P (insn))
2018 instantiate_virtual_regs_in_rtx (INSN_VAR_LOCATION_PTR (insn));
2019 else
2020 instantiate_virtual_regs_in_insn (insn);
2022 if (insn->deleted ())
2023 continue;
2025 instantiate_virtual_regs_in_rtx (&REG_NOTES (insn));
2027 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
2028 if (CALL_P (insn))
2029 instantiate_virtual_regs_in_rtx (&CALL_INSN_FUNCTION_USAGE (insn));
2032 /* Instantiate the virtual registers in the DECLs for debugging purposes. */
2033 instantiate_decls (current_function_decl);
2035 targetm.instantiate_decls ();
2037 /* Indicate that, from now on, assign_stack_local should use
2038 frame_pointer_rtx. */
2039 virtuals_instantiated = 1;
2041 return 0;
2044 namespace {
2046 const pass_data pass_data_instantiate_virtual_regs =
2048 RTL_PASS, /* type */
2049 "vregs", /* name */
2050 OPTGROUP_NONE, /* optinfo_flags */
2051 TV_NONE, /* tv_id */
2052 0, /* properties_required */
2053 0, /* properties_provided */
2054 0, /* properties_destroyed */
2055 0, /* todo_flags_start */
2056 0, /* todo_flags_finish */
2059 class pass_instantiate_virtual_regs : public rtl_opt_pass
2061 public:
2062 pass_instantiate_virtual_regs (gcc::context *ctxt)
2063 : rtl_opt_pass (pass_data_instantiate_virtual_regs, ctxt)
2066 /* opt_pass methods: */
2067 virtual unsigned int execute (function *)
2069 return instantiate_virtual_regs ();
2072 }; // class pass_instantiate_virtual_regs
2074 } // anon namespace
2076 rtl_opt_pass *
2077 make_pass_instantiate_virtual_regs (gcc::context *ctxt)
2079 return new pass_instantiate_virtual_regs (ctxt);
2083 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
2084 This means a type for which function calls must pass an address to the
2085 function or get an address back from the function.
2086 EXP may be a type node or an expression (whose type is tested). */
2089 aggregate_value_p (const_tree exp, const_tree fntype)
2091 const_tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
2092 int i, regno, nregs;
2093 rtx reg;
2095 if (fntype)
2096 switch (TREE_CODE (fntype))
2098 case CALL_EXPR:
2100 tree fndecl = get_callee_fndecl (fntype);
2101 if (fndecl)
2102 fntype = TREE_TYPE (fndecl);
2103 else if (CALL_EXPR_FN (fntype))
2104 fntype = TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (fntype)));
2105 else
2106 /* For internal functions, assume nothing needs to be
2107 returned in memory. */
2108 return 0;
2110 break;
2111 case FUNCTION_DECL:
2112 fntype = TREE_TYPE (fntype);
2113 break;
2114 case FUNCTION_TYPE:
2115 case METHOD_TYPE:
2116 break;
2117 case IDENTIFIER_NODE:
2118 fntype = NULL_TREE;
2119 break;
2120 default:
2121 /* We don't expect other tree types here. */
2122 gcc_unreachable ();
2125 if (VOID_TYPE_P (type))
2126 return 0;
2128 /* If a record should be passed the same as its first (and only) member
2129 don't pass it as an aggregate. */
2130 if (TREE_CODE (type) == RECORD_TYPE && TYPE_TRANSPARENT_AGGR (type))
2131 return aggregate_value_p (first_field (type), fntype);
2133 /* If the front end has decided that this needs to be passed by
2134 reference, do so. */
2135 if ((TREE_CODE (exp) == PARM_DECL || TREE_CODE (exp) == RESULT_DECL)
2136 && DECL_BY_REFERENCE (exp))
2137 return 1;
2139 /* Function types that are TREE_ADDRESSABLE force return in memory. */
2140 if (fntype && TREE_ADDRESSABLE (fntype))
2141 return 1;
2143 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
2144 and thus can't be returned in registers. */
2145 if (TREE_ADDRESSABLE (type))
2146 return 1;
2148 if (TYPE_EMPTY_P (type))
2149 return 0;
2151 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
2152 return 1;
2154 if (targetm.calls.return_in_memory (type, fntype))
2155 return 1;
2157 /* Make sure we have suitable call-clobbered regs to return
2158 the value in; if not, we must return it in memory. */
2159 reg = hard_function_value (type, 0, fntype, 0);
2161 /* If we have something other than a REG (e.g. a PARALLEL), then assume
2162 it is OK. */
2163 if (!REG_P (reg))
2164 return 0;
2166 regno = REGNO (reg);
2167 nregs = hard_regno_nregs (regno, TYPE_MODE (type));
2168 for (i = 0; i < nregs; i++)
2169 if (! call_used_regs[regno + i])
2170 return 1;
2172 return 0;
2175 /* Return true if we should assign DECL a pseudo register; false if it
2176 should live on the local stack. */
2178 bool
2179 use_register_for_decl (const_tree decl)
2181 if (TREE_CODE (decl) == SSA_NAME)
2183 /* We often try to use the SSA_NAME, instead of its underlying
2184 decl, to get type information and guide decisions, to avoid
2185 differences of behavior between anonymous and named
2186 variables, but in this one case we have to go for the actual
2187 variable if there is one. The main reason is that, at least
2188 at -O0, we want to place user variables on the stack, but we
2189 don't mind using pseudos for anonymous or ignored temps.
2190 Should we take the SSA_NAME, we'd conclude all SSA_NAMEs
2191 should go in pseudos, whereas their corresponding variables
2192 might have to go on the stack. So, disregarding the decl
2193 here would negatively impact debug info at -O0, enable
2194 coalescing between SSA_NAMEs that ought to get different
2195 stack/pseudo assignments, and get the incoming argument
2196 processing thoroughly confused by PARM_DECLs expected to live
2197 in stack slots but assigned to pseudos. */
2198 if (!SSA_NAME_VAR (decl))
2199 return TYPE_MODE (TREE_TYPE (decl)) != BLKmode
2200 && !(flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)));
2202 decl = SSA_NAME_VAR (decl);
2205 /* Honor volatile. */
2206 if (TREE_SIDE_EFFECTS (decl))
2207 return false;
2209 /* Honor addressability. */
2210 if (TREE_ADDRESSABLE (decl))
2211 return false;
2213 /* RESULT_DECLs are a bit special in that they're assigned without
2214 regard to use_register_for_decl, but we generally only store in
2215 them. If we coalesce their SSA NAMEs, we'd better return a
2216 result that matches the assignment in expand_function_start. */
2217 if (TREE_CODE (decl) == RESULT_DECL)
2219 /* If it's not an aggregate, we're going to use a REG or a
2220 PARALLEL containing a REG. */
2221 if (!aggregate_value_p (decl, current_function_decl))
2222 return true;
2224 /* If expand_function_start determines the return value, we'll
2225 use MEM if it's not by reference. */
2226 if (cfun->returns_pcc_struct
2227 || (targetm.calls.struct_value_rtx
2228 (TREE_TYPE (current_function_decl), 1)))
2229 return DECL_BY_REFERENCE (decl);
2231 /* Otherwise, we're taking an extra all.function_result_decl
2232 argument. It's set up in assign_parms_augmented_arg_list,
2233 under the (negated) conditions above, and then it's used to
2234 set up the RESULT_DECL rtl in assign_params, after looping
2235 over all parameters. Now, if the RESULT_DECL is not by
2236 reference, we'll use a MEM either way. */
2237 if (!DECL_BY_REFERENCE (decl))
2238 return false;
2240 /* Otherwise, if RESULT_DECL is DECL_BY_REFERENCE, it will take
2241 the function_result_decl's assignment. Since it's a pointer,
2242 we can short-circuit a number of the tests below, and we must
2243 duplicat e them because we don't have the
2244 function_result_decl to test. */
2245 if (!targetm.calls.allocate_stack_slots_for_args ())
2246 return true;
2247 /* We don't set DECL_IGNORED_P for the function_result_decl. */
2248 if (optimize)
2249 return true;
2250 /* We don't set DECL_REGISTER for the function_result_decl. */
2251 return false;
2254 /* Only register-like things go in registers. */
2255 if (DECL_MODE (decl) == BLKmode)
2256 return false;
2258 /* If -ffloat-store specified, don't put explicit float variables
2259 into registers. */
2260 /* ??? This should be checked after DECL_ARTIFICIAL, but tree-ssa
2261 propagates values across these stores, and it probably shouldn't. */
2262 if (flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)))
2263 return false;
2265 if (!targetm.calls.allocate_stack_slots_for_args ())
2266 return true;
2268 /* If we're not interested in tracking debugging information for
2269 this decl, then we can certainly put it in a register. */
2270 if (DECL_IGNORED_P (decl))
2271 return true;
2273 if (optimize)
2274 return true;
2276 if (!DECL_REGISTER (decl))
2277 return false;
2279 /* When not optimizing, disregard register keyword for types that
2280 could have methods, otherwise the methods won't be callable from
2281 the debugger. */
2282 if (RECORD_OR_UNION_TYPE_P (TREE_TYPE (decl)))
2283 return false;
2285 return true;
2288 /* Structures to communicate between the subroutines of assign_parms.
2289 The first holds data persistent across all parameters, the second
2290 is cleared out for each parameter. */
2292 struct assign_parm_data_all
2294 /* When INIT_CUMULATIVE_ARGS gets revamped, allocating CUMULATIVE_ARGS
2295 should become a job of the target or otherwise encapsulated. */
2296 CUMULATIVE_ARGS args_so_far_v;
2297 cumulative_args_t args_so_far;
2298 struct args_size stack_args_size;
2299 tree function_result_decl;
2300 tree orig_fnargs;
2301 rtx_insn *first_conversion_insn;
2302 rtx_insn *last_conversion_insn;
2303 HOST_WIDE_INT pretend_args_size;
2304 HOST_WIDE_INT extra_pretend_bytes;
2305 int reg_parm_stack_space;
2308 struct assign_parm_data_one
2310 tree nominal_type;
2311 tree passed_type;
2312 rtx entry_parm;
2313 rtx stack_parm;
2314 machine_mode nominal_mode;
2315 machine_mode passed_mode;
2316 machine_mode promoted_mode;
2317 struct locate_and_pad_arg_data locate;
2318 int partial;
2319 BOOL_BITFIELD named_arg : 1;
2320 BOOL_BITFIELD passed_pointer : 1;
2321 BOOL_BITFIELD on_stack : 1;
2322 BOOL_BITFIELD loaded_in_reg : 1;
2325 /* A subroutine of assign_parms. Initialize ALL. */
2327 static void
2328 assign_parms_initialize_all (struct assign_parm_data_all *all)
2330 tree fntype ATTRIBUTE_UNUSED;
2332 memset (all, 0, sizeof (*all));
2334 fntype = TREE_TYPE (current_function_decl);
2336 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
2337 INIT_CUMULATIVE_INCOMING_ARGS (all->args_so_far_v, fntype, NULL_RTX);
2338 #else
2339 INIT_CUMULATIVE_ARGS (all->args_so_far_v, fntype, NULL_RTX,
2340 current_function_decl, -1);
2341 #endif
2342 all->args_so_far = pack_cumulative_args (&all->args_so_far_v);
2344 #ifdef INCOMING_REG_PARM_STACK_SPACE
2345 all->reg_parm_stack_space
2346 = INCOMING_REG_PARM_STACK_SPACE (current_function_decl);
2347 #endif
2350 /* If ARGS contains entries with complex types, split the entry into two
2351 entries of the component type. Return a new list of substitutions are
2352 needed, else the old list. */
2354 static void
2355 split_complex_args (vec<tree> *args)
2357 unsigned i;
2358 tree p;
2360 FOR_EACH_VEC_ELT (*args, i, p)
2362 tree type = TREE_TYPE (p);
2363 if (TREE_CODE (type) == COMPLEX_TYPE
2364 && targetm.calls.split_complex_arg (type))
2366 tree decl;
2367 tree subtype = TREE_TYPE (type);
2368 bool addressable = TREE_ADDRESSABLE (p);
2370 /* Rewrite the PARM_DECL's type with its component. */
2371 p = copy_node (p);
2372 TREE_TYPE (p) = subtype;
2373 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
2374 SET_DECL_MODE (p, VOIDmode);
2375 DECL_SIZE (p) = NULL;
2376 DECL_SIZE_UNIT (p) = NULL;
2377 /* If this arg must go in memory, put it in a pseudo here.
2378 We can't allow it to go in memory as per normal parms,
2379 because the usual place might not have the imag part
2380 adjacent to the real part. */
2381 DECL_ARTIFICIAL (p) = addressable;
2382 DECL_IGNORED_P (p) = addressable;
2383 TREE_ADDRESSABLE (p) = 0;
2384 layout_decl (p, 0);
2385 (*args)[i] = p;
2387 /* Build a second synthetic decl. */
2388 decl = build_decl (EXPR_LOCATION (p),
2389 PARM_DECL, NULL_TREE, subtype);
2390 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
2391 DECL_ARTIFICIAL (decl) = addressable;
2392 DECL_IGNORED_P (decl) = addressable;
2393 layout_decl (decl, 0);
2394 args->safe_insert (++i, decl);
2399 /* A subroutine of assign_parms. Adjust the parameter list to incorporate
2400 the hidden struct return argument, and (abi willing) complex args.
2401 Return the new parameter list. */
2403 static vec<tree>
2404 assign_parms_augmented_arg_list (struct assign_parm_data_all *all)
2406 tree fndecl = current_function_decl;
2407 tree fntype = TREE_TYPE (fndecl);
2408 vec<tree> fnargs = vNULL;
2409 tree arg;
2411 for (arg = DECL_ARGUMENTS (fndecl); arg; arg = DECL_CHAIN (arg))
2412 fnargs.safe_push (arg);
2414 all->orig_fnargs = DECL_ARGUMENTS (fndecl);
2416 /* If struct value address is treated as the first argument, make it so. */
2417 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
2418 && ! cfun->returns_pcc_struct
2419 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
2421 tree type = build_pointer_type (TREE_TYPE (fntype));
2422 tree decl;
2424 decl = build_decl (DECL_SOURCE_LOCATION (fndecl),
2425 PARM_DECL, get_identifier (".result_ptr"), type);
2426 DECL_ARG_TYPE (decl) = type;
2427 DECL_ARTIFICIAL (decl) = 1;
2428 DECL_NAMELESS (decl) = 1;
2429 TREE_CONSTANT (decl) = 1;
2430 /* We don't set DECL_IGNORED_P or DECL_REGISTER here. If this
2431 changes, the end of the RESULT_DECL handling block in
2432 use_register_for_decl must be adjusted to match. */
2434 DECL_CHAIN (decl) = all->orig_fnargs;
2435 all->orig_fnargs = decl;
2436 fnargs.safe_insert (0, decl);
2438 all->function_result_decl = decl;
2441 /* If the target wants to split complex arguments into scalars, do so. */
2442 if (targetm.calls.split_complex_arg)
2443 split_complex_args (&fnargs);
2445 return fnargs;
2448 /* A subroutine of assign_parms. Examine PARM and pull out type and mode
2449 data for the parameter. Incorporate ABI specifics such as pass-by-
2450 reference and type promotion. */
2452 static void
2453 assign_parm_find_data_types (struct assign_parm_data_all *all, tree parm,
2454 struct assign_parm_data_one *data)
2456 tree nominal_type, passed_type;
2457 machine_mode nominal_mode, passed_mode, promoted_mode;
2458 int unsignedp;
2460 memset (data, 0, sizeof (*data));
2462 /* NAMED_ARG is a misnomer. We really mean 'non-variadic'. */
2463 if (!cfun->stdarg)
2464 data->named_arg = 1; /* No variadic parms. */
2465 else if (DECL_CHAIN (parm))
2466 data->named_arg = 1; /* Not the last non-variadic parm. */
2467 else if (targetm.calls.strict_argument_naming (all->args_so_far))
2468 data->named_arg = 1; /* Only variadic ones are unnamed. */
2469 else
2470 data->named_arg = 0; /* Treat as variadic. */
2472 nominal_type = TREE_TYPE (parm);
2473 passed_type = DECL_ARG_TYPE (parm);
2475 /* Look out for errors propagating this far. Also, if the parameter's
2476 type is void then its value doesn't matter. */
2477 if (TREE_TYPE (parm) == error_mark_node
2478 /* This can happen after weird syntax errors
2479 or if an enum type is defined among the parms. */
2480 || TREE_CODE (parm) != PARM_DECL
2481 || passed_type == NULL
2482 || VOID_TYPE_P (nominal_type))
2484 nominal_type = passed_type = void_type_node;
2485 nominal_mode = passed_mode = promoted_mode = VOIDmode;
2486 goto egress;
2489 /* Find mode of arg as it is passed, and mode of arg as it should be
2490 during execution of this function. */
2491 passed_mode = TYPE_MODE (passed_type);
2492 nominal_mode = TYPE_MODE (nominal_type);
2494 /* If the parm is to be passed as a transparent union or record, use the
2495 type of the first field for the tests below. We have already verified
2496 that the modes are the same. */
2497 if ((TREE_CODE (passed_type) == UNION_TYPE
2498 || TREE_CODE (passed_type) == RECORD_TYPE)
2499 && TYPE_TRANSPARENT_AGGR (passed_type))
2500 passed_type = TREE_TYPE (first_field (passed_type));
2502 /* See if this arg was passed by invisible reference. */
2503 if (pass_by_reference (&all->args_so_far_v, passed_mode,
2504 passed_type, data->named_arg))
2506 passed_type = nominal_type = build_pointer_type (passed_type);
2507 data->passed_pointer = true;
2508 passed_mode = nominal_mode = TYPE_MODE (nominal_type);
2511 /* Find mode as it is passed by the ABI. */
2512 unsignedp = TYPE_UNSIGNED (passed_type);
2513 promoted_mode = promote_function_mode (passed_type, passed_mode, &unsignedp,
2514 TREE_TYPE (current_function_decl), 0);
2516 egress:
2517 data->nominal_type = nominal_type;
2518 data->passed_type = passed_type;
2519 data->nominal_mode = nominal_mode;
2520 data->passed_mode = passed_mode;
2521 data->promoted_mode = promoted_mode;
2524 /* A subroutine of assign_parms. Invoke setup_incoming_varargs. */
2526 static void
2527 assign_parms_setup_varargs (struct assign_parm_data_all *all,
2528 struct assign_parm_data_one *data, bool no_rtl)
2530 int varargs_pretend_bytes = 0;
2532 targetm.calls.setup_incoming_varargs (all->args_so_far,
2533 data->promoted_mode,
2534 data->passed_type,
2535 &varargs_pretend_bytes, no_rtl);
2537 /* If the back-end has requested extra stack space, record how much is
2538 needed. Do not change pretend_args_size otherwise since it may be
2539 nonzero from an earlier partial argument. */
2540 if (varargs_pretend_bytes > 0)
2541 all->pretend_args_size = varargs_pretend_bytes;
2544 /* A subroutine of assign_parms. Set DATA->ENTRY_PARM corresponding to
2545 the incoming location of the current parameter. */
2547 static void
2548 assign_parm_find_entry_rtl (struct assign_parm_data_all *all,
2549 struct assign_parm_data_one *data)
2551 HOST_WIDE_INT pretend_bytes = 0;
2552 rtx entry_parm;
2553 bool in_regs;
2555 if (data->promoted_mode == VOIDmode)
2557 data->entry_parm = data->stack_parm = const0_rtx;
2558 return;
2561 targetm.calls.warn_parameter_passing_abi (all->args_so_far,
2562 data->passed_type);
2564 entry_parm = targetm.calls.function_incoming_arg (all->args_so_far,
2565 data->promoted_mode,
2566 data->passed_type,
2567 data->named_arg);
2569 if (entry_parm == 0)
2570 data->promoted_mode = data->passed_mode;
2572 /* Determine parm's home in the stack, in case it arrives in the stack
2573 or we should pretend it did. Compute the stack position and rtx where
2574 the argument arrives and its size.
2576 There is one complexity here: If this was a parameter that would
2577 have been passed in registers, but wasn't only because it is
2578 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2579 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2580 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of 0
2581 as it was the previous time. */
2582 in_regs = (entry_parm != 0);
2583 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2584 in_regs = true;
2585 #endif
2586 if (!in_regs && !data->named_arg)
2588 if (targetm.calls.pretend_outgoing_varargs_named (all->args_so_far))
2590 rtx tem;
2591 tem = targetm.calls.function_incoming_arg (all->args_so_far,
2592 data->promoted_mode,
2593 data->passed_type, true);
2594 in_regs = tem != NULL;
2598 /* If this parameter was passed both in registers and in the stack, use
2599 the copy on the stack. */
2600 if (targetm.calls.must_pass_in_stack (data->promoted_mode,
2601 data->passed_type))
2602 entry_parm = 0;
2604 if (entry_parm)
2606 int partial;
2608 partial = targetm.calls.arg_partial_bytes (all->args_so_far,
2609 data->promoted_mode,
2610 data->passed_type,
2611 data->named_arg);
2612 data->partial = partial;
2614 /* The caller might already have allocated stack space for the
2615 register parameters. */
2616 if (partial != 0 && all->reg_parm_stack_space == 0)
2618 /* Part of this argument is passed in registers and part
2619 is passed on the stack. Ask the prologue code to extend
2620 the stack part so that we can recreate the full value.
2622 PRETEND_BYTES is the size of the registers we need to store.
2623 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
2624 stack space that the prologue should allocate.
2626 Internally, gcc assumes that the argument pointer is aligned
2627 to STACK_BOUNDARY bits. This is used both for alignment
2628 optimizations (see init_emit) and to locate arguments that are
2629 aligned to more than PARM_BOUNDARY bits. We must preserve this
2630 invariant by rounding CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to
2631 a stack boundary. */
2633 /* We assume at most one partial arg, and it must be the first
2634 argument on the stack. */
2635 gcc_assert (!all->extra_pretend_bytes && !all->pretend_args_size);
2637 pretend_bytes = partial;
2638 all->pretend_args_size = CEIL_ROUND (pretend_bytes, STACK_BYTES);
2640 /* We want to align relative to the actual stack pointer, so
2641 don't include this in the stack size until later. */
2642 all->extra_pretend_bytes = all->pretend_args_size;
2646 locate_and_pad_parm (data->promoted_mode, data->passed_type, in_regs,
2647 all->reg_parm_stack_space,
2648 entry_parm ? data->partial : 0, current_function_decl,
2649 &all->stack_args_size, &data->locate);
2651 /* Update parm_stack_boundary if this parameter is passed in the
2652 stack. */
2653 if (!in_regs && crtl->parm_stack_boundary < data->locate.boundary)
2654 crtl->parm_stack_boundary = data->locate.boundary;
2656 /* Adjust offsets to include the pretend args. */
2657 pretend_bytes = all->extra_pretend_bytes - pretend_bytes;
2658 data->locate.slot_offset.constant += pretend_bytes;
2659 data->locate.offset.constant += pretend_bytes;
2661 data->entry_parm = entry_parm;
2664 /* A subroutine of assign_parms. If there is actually space on the stack
2665 for this parm, count it in stack_args_size and return true. */
2667 static bool
2668 assign_parm_is_stack_parm (struct assign_parm_data_all *all,
2669 struct assign_parm_data_one *data)
2671 /* Trivially true if we've no incoming register. */
2672 if (data->entry_parm == NULL)
2674 /* Also true if we're partially in registers and partially not,
2675 since we've arranged to drop the entire argument on the stack. */
2676 else if (data->partial != 0)
2678 /* Also true if the target says that it's passed in both registers
2679 and on the stack. */
2680 else if (GET_CODE (data->entry_parm) == PARALLEL
2681 && XEXP (XVECEXP (data->entry_parm, 0, 0), 0) == NULL_RTX)
2683 /* Also true if the target says that there's stack allocated for
2684 all register parameters. */
2685 else if (all->reg_parm_stack_space > 0)
2687 /* Otherwise, no, this parameter has no ABI defined stack slot. */
2688 else
2689 return false;
2691 all->stack_args_size.constant += data->locate.size.constant;
2692 if (data->locate.size.var)
2693 ADD_PARM_SIZE (all->stack_args_size, data->locate.size.var);
2695 return true;
2698 /* A subroutine of assign_parms. Given that this parameter is allocated
2699 stack space by the ABI, find it. */
2701 static void
2702 assign_parm_find_stack_rtl (tree parm, struct assign_parm_data_one *data)
2704 rtx offset_rtx, stack_parm;
2705 unsigned int align, boundary;
2707 /* If we're passing this arg using a reg, make its stack home the
2708 aligned stack slot. */
2709 if (data->entry_parm)
2710 offset_rtx = ARGS_SIZE_RTX (data->locate.slot_offset);
2711 else
2712 offset_rtx = ARGS_SIZE_RTX (data->locate.offset);
2714 stack_parm = crtl->args.internal_arg_pointer;
2715 if (offset_rtx != const0_rtx)
2716 stack_parm = gen_rtx_PLUS (Pmode, stack_parm, offset_rtx);
2717 stack_parm = gen_rtx_MEM (data->promoted_mode, stack_parm);
2719 if (!data->passed_pointer)
2721 set_mem_attributes (stack_parm, parm, 1);
2722 /* set_mem_attributes could set MEM_SIZE to the passed mode's size,
2723 while promoted mode's size is needed. */
2724 if (data->promoted_mode != BLKmode
2725 && data->promoted_mode != DECL_MODE (parm))
2727 set_mem_size (stack_parm, GET_MODE_SIZE (data->promoted_mode));
2728 if (MEM_EXPR (stack_parm) && MEM_OFFSET_KNOWN_P (stack_parm))
2730 poly_int64 offset = subreg_lowpart_offset (DECL_MODE (parm),
2731 data->promoted_mode);
2732 if (maybe_ne (offset, 0))
2733 set_mem_offset (stack_parm, MEM_OFFSET (stack_parm) - offset);
2738 boundary = data->locate.boundary;
2739 align = BITS_PER_UNIT;
2741 /* If we're padding upward, we know that the alignment of the slot
2742 is TARGET_FUNCTION_ARG_BOUNDARY. If we're using slot_offset, we're
2743 intentionally forcing upward padding. Otherwise we have to come
2744 up with a guess at the alignment based on OFFSET_RTX. */
2745 poly_int64 offset;
2746 if (data->locate.where_pad != PAD_DOWNWARD || data->entry_parm)
2747 align = boundary;
2748 else if (poly_int_rtx_p (offset_rtx, &offset))
2750 align = least_bit_hwi (boundary);
2751 unsigned int offset_align = known_alignment (offset) * BITS_PER_UNIT;
2752 if (offset_align != 0)
2753 align = MIN (align, offset_align);
2755 set_mem_align (stack_parm, align);
2757 if (data->entry_parm)
2758 set_reg_attrs_for_parm (data->entry_parm, stack_parm);
2760 data->stack_parm = stack_parm;
2763 /* A subroutine of assign_parms. Adjust DATA->ENTRY_RTL such that it's
2764 always valid and contiguous. */
2766 static void
2767 assign_parm_adjust_entry_rtl (struct assign_parm_data_one *data)
2769 rtx entry_parm = data->entry_parm;
2770 rtx stack_parm = data->stack_parm;
2772 /* If this parm was passed part in regs and part in memory, pretend it
2773 arrived entirely in memory by pushing the register-part onto the stack.
2774 In the special case of a DImode or DFmode that is split, we could put
2775 it together in a pseudoreg directly, but for now that's not worth
2776 bothering with. */
2777 if (data->partial != 0)
2779 /* Handle calls that pass values in multiple non-contiguous
2780 locations. The Irix 6 ABI has examples of this. */
2781 if (GET_CODE (entry_parm) == PARALLEL)
2782 emit_group_store (validize_mem (copy_rtx (stack_parm)), entry_parm,
2783 data->passed_type,
2784 int_size_in_bytes (data->passed_type));
2785 else
2787 gcc_assert (data->partial % UNITS_PER_WORD == 0);
2788 move_block_from_reg (REGNO (entry_parm),
2789 validize_mem (copy_rtx (stack_parm)),
2790 data->partial / UNITS_PER_WORD);
2793 entry_parm = stack_parm;
2796 /* If we didn't decide this parm came in a register, by default it came
2797 on the stack. */
2798 else if (entry_parm == NULL)
2799 entry_parm = stack_parm;
2801 /* When an argument is passed in multiple locations, we can't make use
2802 of this information, but we can save some copying if the whole argument
2803 is passed in a single register. */
2804 else if (GET_CODE (entry_parm) == PARALLEL
2805 && data->nominal_mode != BLKmode
2806 && data->passed_mode != BLKmode)
2808 size_t i, len = XVECLEN (entry_parm, 0);
2810 for (i = 0; i < len; i++)
2811 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
2812 && REG_P (XEXP (XVECEXP (entry_parm, 0, i), 0))
2813 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
2814 == data->passed_mode)
2815 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
2817 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
2818 break;
2822 data->entry_parm = entry_parm;
2825 /* A subroutine of assign_parms. Reconstitute any values which were
2826 passed in multiple registers and would fit in a single register. */
2828 static void
2829 assign_parm_remove_parallels (struct assign_parm_data_one *data)
2831 rtx entry_parm = data->entry_parm;
2833 /* Convert the PARALLEL to a REG of the same mode as the parallel.
2834 This can be done with register operations rather than on the
2835 stack, even if we will store the reconstituted parameter on the
2836 stack later. */
2837 if (GET_CODE (entry_parm) == PARALLEL && GET_MODE (entry_parm) != BLKmode)
2839 rtx parmreg = gen_reg_rtx (GET_MODE (entry_parm));
2840 emit_group_store (parmreg, entry_parm, data->passed_type,
2841 GET_MODE_SIZE (GET_MODE (entry_parm)));
2842 entry_parm = parmreg;
2845 data->entry_parm = entry_parm;
2848 /* A subroutine of assign_parms. Adjust DATA->STACK_RTL such that it's
2849 always valid and properly aligned. */
2851 static void
2852 assign_parm_adjust_stack_rtl (struct assign_parm_data_one *data)
2854 rtx stack_parm = data->stack_parm;
2856 /* If we can't trust the parm stack slot to be aligned enough for its
2857 ultimate type, don't use that slot after entry. We'll make another
2858 stack slot, if we need one. */
2859 if (stack_parm
2860 && ((STRICT_ALIGNMENT
2861 && GET_MODE_ALIGNMENT (data->nominal_mode) > MEM_ALIGN (stack_parm))
2862 || (data->nominal_type
2863 && TYPE_ALIGN (data->nominal_type) > MEM_ALIGN (stack_parm)
2864 && MEM_ALIGN (stack_parm) < PREFERRED_STACK_BOUNDARY)))
2865 stack_parm = NULL;
2867 /* If parm was passed in memory, and we need to convert it on entry,
2868 don't store it back in that same slot. */
2869 else if (data->entry_parm == stack_parm
2870 && data->nominal_mode != BLKmode
2871 && data->nominal_mode != data->passed_mode)
2872 stack_parm = NULL;
2874 /* If stack protection is in effect for this function, don't leave any
2875 pointers in their passed stack slots. */
2876 else if (crtl->stack_protect_guard
2877 && (flag_stack_protect == 2
2878 || data->passed_pointer
2879 || POINTER_TYPE_P (data->nominal_type)))
2880 stack_parm = NULL;
2882 data->stack_parm = stack_parm;
2885 /* A subroutine of assign_parms. Return true if the current parameter
2886 should be stored as a BLKmode in the current frame. */
2888 static bool
2889 assign_parm_setup_block_p (struct assign_parm_data_one *data)
2891 if (data->nominal_mode == BLKmode)
2892 return true;
2893 if (GET_MODE (data->entry_parm) == BLKmode)
2894 return true;
2896 #ifdef BLOCK_REG_PADDING
2897 /* Only assign_parm_setup_block knows how to deal with register arguments
2898 that are padded at the least significant end. */
2899 if (REG_P (data->entry_parm)
2900 && known_lt (GET_MODE_SIZE (data->promoted_mode), UNITS_PER_WORD)
2901 && (BLOCK_REG_PADDING (data->passed_mode, data->passed_type, 1)
2902 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
2903 return true;
2904 #endif
2906 return false;
2909 /* A subroutine of assign_parms. Arrange for the parameter to be
2910 present and valid in DATA->STACK_RTL. */
2912 static void
2913 assign_parm_setup_block (struct assign_parm_data_all *all,
2914 tree parm, struct assign_parm_data_one *data)
2916 rtx entry_parm = data->entry_parm;
2917 rtx stack_parm = data->stack_parm;
2918 rtx target_reg = NULL_RTX;
2919 bool in_conversion_seq = false;
2920 HOST_WIDE_INT size;
2921 HOST_WIDE_INT size_stored;
2923 if (GET_CODE (entry_parm) == PARALLEL)
2924 entry_parm = emit_group_move_into_temps (entry_parm);
2926 /* If we want the parameter in a pseudo, don't use a stack slot. */
2927 if (is_gimple_reg (parm) && use_register_for_decl (parm))
2929 tree def = ssa_default_def (cfun, parm);
2930 gcc_assert (def);
2931 machine_mode mode = promote_ssa_mode (def, NULL);
2932 rtx reg = gen_reg_rtx (mode);
2933 if (GET_CODE (reg) != CONCAT)
2934 stack_parm = reg;
2935 else
2937 target_reg = reg;
2938 /* Avoid allocating a stack slot, if there isn't one
2939 preallocated by the ABI. It might seem like we should
2940 always prefer a pseudo, but converting between
2941 floating-point and integer modes goes through the stack
2942 on various machines, so it's better to use the reserved
2943 stack slot than to risk wasting it and allocating more
2944 for the conversion. */
2945 if (stack_parm == NULL_RTX)
2947 int save = generating_concat_p;
2948 generating_concat_p = 0;
2949 stack_parm = gen_reg_rtx (mode);
2950 generating_concat_p = save;
2953 data->stack_parm = NULL;
2956 size = int_size_in_bytes (data->passed_type);
2957 size_stored = CEIL_ROUND (size, UNITS_PER_WORD);
2958 if (stack_parm == 0)
2960 SET_DECL_ALIGN (parm, MAX (DECL_ALIGN (parm), BITS_PER_WORD));
2961 stack_parm = assign_stack_local (BLKmode, size_stored,
2962 DECL_ALIGN (parm));
2963 if (known_eq (GET_MODE_SIZE (GET_MODE (entry_parm)), size))
2964 PUT_MODE (stack_parm, GET_MODE (entry_parm));
2965 set_mem_attributes (stack_parm, parm, 1);
2968 /* If a BLKmode arrives in registers, copy it to a stack slot. Handle
2969 calls that pass values in multiple non-contiguous locations. */
2970 if (REG_P (entry_parm) || GET_CODE (entry_parm) == PARALLEL)
2972 rtx mem;
2974 /* Note that we will be storing an integral number of words.
2975 So we have to be careful to ensure that we allocate an
2976 integral number of words. We do this above when we call
2977 assign_stack_local if space was not allocated in the argument
2978 list. If it was, this will not work if PARM_BOUNDARY is not
2979 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2980 if it becomes a problem. Exception is when BLKmode arrives
2981 with arguments not conforming to word_mode. */
2983 if (data->stack_parm == 0)
2985 else if (GET_CODE (entry_parm) == PARALLEL)
2987 else
2988 gcc_assert (!size || !(PARM_BOUNDARY % BITS_PER_WORD));
2990 mem = validize_mem (copy_rtx (stack_parm));
2992 /* Handle values in multiple non-contiguous locations. */
2993 if (GET_CODE (entry_parm) == PARALLEL && !MEM_P (mem))
2994 emit_group_store (mem, entry_parm, data->passed_type, size);
2995 else if (GET_CODE (entry_parm) == PARALLEL)
2997 push_to_sequence2 (all->first_conversion_insn,
2998 all->last_conversion_insn);
2999 emit_group_store (mem, entry_parm, data->passed_type, size);
3000 all->first_conversion_insn = get_insns ();
3001 all->last_conversion_insn = get_last_insn ();
3002 end_sequence ();
3003 in_conversion_seq = true;
3006 else if (size == 0)
3009 /* If SIZE is that of a mode no bigger than a word, just use
3010 that mode's store operation. */
3011 else if (size <= UNITS_PER_WORD)
3013 unsigned int bits = size * BITS_PER_UNIT;
3014 machine_mode mode = int_mode_for_size (bits, 0).else_blk ();
3016 if (mode != BLKmode
3017 #ifdef BLOCK_REG_PADDING
3018 && (size == UNITS_PER_WORD
3019 || (BLOCK_REG_PADDING (mode, data->passed_type, 1)
3020 != (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
3021 #endif
3024 rtx reg;
3026 /* We are really truncating a word_mode value containing
3027 SIZE bytes into a value of mode MODE. If such an
3028 operation requires no actual instructions, we can refer
3029 to the value directly in mode MODE, otherwise we must
3030 start with the register in word_mode and explicitly
3031 convert it. */
3032 if (targetm.truly_noop_truncation (size * BITS_PER_UNIT,
3033 BITS_PER_WORD))
3034 reg = gen_rtx_REG (mode, REGNO (entry_parm));
3035 else
3037 reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
3038 reg = convert_to_mode (mode, copy_to_reg (reg), 1);
3040 emit_move_insn (change_address (mem, mode, 0), reg);
3043 #ifdef BLOCK_REG_PADDING
3044 /* Storing the register in memory as a full word, as
3045 move_block_from_reg below would do, and then using the
3046 MEM in a smaller mode, has the effect of shifting right
3047 if BYTES_BIG_ENDIAN. If we're bypassing memory, the
3048 shifting must be explicit. */
3049 else if (!MEM_P (mem))
3051 rtx x;
3053 /* If the assert below fails, we should have taken the
3054 mode != BLKmode path above, unless we have downward
3055 padding of smaller-than-word arguments on a machine
3056 with little-endian bytes, which would likely require
3057 additional changes to work correctly. */
3058 gcc_checking_assert (BYTES_BIG_ENDIAN
3059 && (BLOCK_REG_PADDING (mode,
3060 data->passed_type, 1)
3061 == PAD_UPWARD));
3063 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
3065 x = gen_rtx_REG (word_mode, REGNO (entry_parm));
3066 x = expand_shift (RSHIFT_EXPR, word_mode, x, by,
3067 NULL_RTX, 1);
3068 x = force_reg (word_mode, x);
3069 x = gen_lowpart_SUBREG (GET_MODE (mem), x);
3071 emit_move_insn (mem, x);
3073 #endif
3075 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
3076 machine must be aligned to the left before storing
3077 to memory. Note that the previous test doesn't
3078 handle all cases (e.g. SIZE == 3). */
3079 else if (size != UNITS_PER_WORD
3080 #ifdef BLOCK_REG_PADDING
3081 && (BLOCK_REG_PADDING (mode, data->passed_type, 1)
3082 == PAD_DOWNWARD)
3083 #else
3084 && BYTES_BIG_ENDIAN
3085 #endif
3088 rtx tem, x;
3089 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
3090 rtx reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
3092 x = expand_shift (LSHIFT_EXPR, word_mode, reg, by, NULL_RTX, 1);
3093 tem = change_address (mem, word_mode, 0);
3094 emit_move_insn (tem, x);
3096 else
3097 move_block_from_reg (REGNO (entry_parm), mem,
3098 size_stored / UNITS_PER_WORD);
3100 else if (!MEM_P (mem))
3102 gcc_checking_assert (size > UNITS_PER_WORD);
3103 #ifdef BLOCK_REG_PADDING
3104 gcc_checking_assert (BLOCK_REG_PADDING (GET_MODE (mem),
3105 data->passed_type, 0)
3106 == PAD_UPWARD);
3107 #endif
3108 emit_move_insn (mem, entry_parm);
3110 else
3111 move_block_from_reg (REGNO (entry_parm), mem,
3112 size_stored / UNITS_PER_WORD);
3114 else if (data->stack_parm == 0)
3116 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3117 emit_block_move (stack_parm, data->entry_parm, GEN_INT (size),
3118 BLOCK_OP_NORMAL);
3119 all->first_conversion_insn = get_insns ();
3120 all->last_conversion_insn = get_last_insn ();
3121 end_sequence ();
3122 in_conversion_seq = true;
3125 if (target_reg)
3127 if (!in_conversion_seq)
3128 emit_move_insn (target_reg, stack_parm);
3129 else
3131 push_to_sequence2 (all->first_conversion_insn,
3132 all->last_conversion_insn);
3133 emit_move_insn (target_reg, stack_parm);
3134 all->first_conversion_insn = get_insns ();
3135 all->last_conversion_insn = get_last_insn ();
3136 end_sequence ();
3138 stack_parm = target_reg;
3141 data->stack_parm = stack_parm;
3142 set_parm_rtl (parm, stack_parm);
3145 /* A subroutine of assign_parms. Allocate a pseudo to hold the current
3146 parameter. Get it there. Perform all ABI specified conversions. */
3148 static void
3149 assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm,
3150 struct assign_parm_data_one *data)
3152 rtx parmreg, validated_mem;
3153 rtx equiv_stack_parm;
3154 machine_mode promoted_nominal_mode;
3155 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (parm));
3156 bool did_conversion = false;
3157 bool need_conversion, moved;
3158 rtx rtl;
3160 /* Store the parm in a pseudoregister during the function, but we may
3161 need to do it in a wider mode. Using 2 here makes the result
3162 consistent with promote_decl_mode and thus expand_expr_real_1. */
3163 promoted_nominal_mode
3164 = promote_function_mode (data->nominal_type, data->nominal_mode, &unsignedp,
3165 TREE_TYPE (current_function_decl), 2);
3167 parmreg = gen_reg_rtx (promoted_nominal_mode);
3168 if (!DECL_ARTIFICIAL (parm))
3169 mark_user_reg (parmreg);
3171 /* If this was an item that we received a pointer to,
3172 set rtl appropriately. */
3173 if (data->passed_pointer)
3175 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data->passed_type)), parmreg);
3176 set_mem_attributes (rtl, parm, 1);
3178 else
3179 rtl = parmreg;
3181 assign_parm_remove_parallels (data);
3183 /* Copy the value into the register, thus bridging between
3184 assign_parm_find_data_types and expand_expr_real_1. */
3186 equiv_stack_parm = data->stack_parm;
3187 validated_mem = validize_mem (copy_rtx (data->entry_parm));
3189 need_conversion = (data->nominal_mode != data->passed_mode
3190 || promoted_nominal_mode != data->promoted_mode);
3191 moved = false;
3193 if (need_conversion
3194 && GET_MODE_CLASS (data->nominal_mode) == MODE_INT
3195 && data->nominal_mode == data->passed_mode
3196 && data->nominal_mode == GET_MODE (data->entry_parm))
3198 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
3199 mode, by the caller. We now have to convert it to
3200 NOMINAL_MODE, if different. However, PARMREG may be in
3201 a different mode than NOMINAL_MODE if it is being stored
3202 promoted.
3204 If ENTRY_PARM is a hard register, it might be in a register
3205 not valid for operating in its mode (e.g., an odd-numbered
3206 register for a DFmode). In that case, moves are the only
3207 thing valid, so we can't do a convert from there. This
3208 occurs when the calling sequence allow such misaligned
3209 usages.
3211 In addition, the conversion may involve a call, which could
3212 clobber parameters which haven't been copied to pseudo
3213 registers yet.
3215 First, we try to emit an insn which performs the necessary
3216 conversion. We verify that this insn does not clobber any
3217 hard registers. */
3219 enum insn_code icode;
3220 rtx op0, op1;
3222 icode = can_extend_p (promoted_nominal_mode, data->passed_mode,
3223 unsignedp);
3225 op0 = parmreg;
3226 op1 = validated_mem;
3227 if (icode != CODE_FOR_nothing
3228 && insn_operand_matches (icode, 0, op0)
3229 && insn_operand_matches (icode, 1, op1))
3231 enum rtx_code code = unsignedp ? ZERO_EXTEND : SIGN_EXTEND;
3232 rtx_insn *insn, *insns;
3233 rtx t = op1;
3234 HARD_REG_SET hardregs;
3236 start_sequence ();
3237 /* If op1 is a hard register that is likely spilled, first
3238 force it into a pseudo, otherwise combiner might extend
3239 its lifetime too much. */
3240 if (GET_CODE (t) == SUBREG)
3241 t = SUBREG_REG (t);
3242 if (REG_P (t)
3243 && HARD_REGISTER_P (t)
3244 && ! TEST_HARD_REG_BIT (fixed_reg_set, REGNO (t))
3245 && targetm.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (t))))
3247 t = gen_reg_rtx (GET_MODE (op1));
3248 emit_move_insn (t, op1);
3250 else
3251 t = op1;
3252 rtx_insn *pat = gen_extend_insn (op0, t, promoted_nominal_mode,
3253 data->passed_mode, unsignedp);
3254 emit_insn (pat);
3255 insns = get_insns ();
3257 moved = true;
3258 CLEAR_HARD_REG_SET (hardregs);
3259 for (insn = insns; insn && moved; insn = NEXT_INSN (insn))
3261 if (INSN_P (insn))
3262 note_stores (PATTERN (insn), record_hard_reg_sets,
3263 &hardregs);
3264 if (!hard_reg_set_empty_p (hardregs))
3265 moved = false;
3268 end_sequence ();
3270 if (moved)
3272 emit_insn (insns);
3273 if (equiv_stack_parm != NULL_RTX)
3274 equiv_stack_parm = gen_rtx_fmt_e (code, GET_MODE (parmreg),
3275 equiv_stack_parm);
3280 if (moved)
3281 /* Nothing to do. */
3283 else if (need_conversion)
3285 /* We did not have an insn to convert directly, or the sequence
3286 generated appeared unsafe. We must first copy the parm to a
3287 pseudo reg, and save the conversion until after all
3288 parameters have been moved. */
3290 int save_tree_used;
3291 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
3293 emit_move_insn (tempreg, validated_mem);
3295 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3296 tempreg = convert_to_mode (data->nominal_mode, tempreg, unsignedp);
3298 if (partial_subreg_p (tempreg)
3299 && GET_MODE (tempreg) == data->nominal_mode
3300 && REG_P (SUBREG_REG (tempreg))
3301 && data->nominal_mode == data->passed_mode
3302 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (data->entry_parm))
3304 /* The argument is already sign/zero extended, so note it
3305 into the subreg. */
3306 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
3307 SUBREG_PROMOTED_SET (tempreg, unsignedp);
3310 /* TREE_USED gets set erroneously during expand_assignment. */
3311 save_tree_used = TREE_USED (parm);
3312 SET_DECL_RTL (parm, rtl);
3313 expand_assignment (parm, make_tree (data->nominal_type, tempreg), false);
3314 SET_DECL_RTL (parm, NULL_RTX);
3315 TREE_USED (parm) = save_tree_used;
3316 all->first_conversion_insn = get_insns ();
3317 all->last_conversion_insn = get_last_insn ();
3318 end_sequence ();
3320 did_conversion = true;
3322 else
3323 emit_move_insn (parmreg, validated_mem);
3325 /* If we were passed a pointer but the actual value can safely live
3326 in a register, retrieve it and use it directly. */
3327 if (data->passed_pointer && TYPE_MODE (TREE_TYPE (parm)) != BLKmode)
3329 /* We can't use nominal_mode, because it will have been set to
3330 Pmode above. We must use the actual mode of the parm. */
3331 if (use_register_for_decl (parm))
3333 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
3334 mark_user_reg (parmreg);
3336 else
3338 int align = STACK_SLOT_ALIGNMENT (TREE_TYPE (parm),
3339 TYPE_MODE (TREE_TYPE (parm)),
3340 TYPE_ALIGN (TREE_TYPE (parm)));
3341 parmreg
3342 = assign_stack_local (TYPE_MODE (TREE_TYPE (parm)),
3343 GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (parm))),
3344 align);
3345 set_mem_attributes (parmreg, parm, 1);
3348 /* We need to preserve an address based on VIRTUAL_STACK_VARS_REGNUM for
3349 the debug info in case it is not legitimate. */
3350 if (GET_MODE (parmreg) != GET_MODE (rtl))
3352 rtx tempreg = gen_reg_rtx (GET_MODE (rtl));
3353 int unsigned_p = TYPE_UNSIGNED (TREE_TYPE (parm));
3355 push_to_sequence2 (all->first_conversion_insn,
3356 all->last_conversion_insn);
3357 emit_move_insn (tempreg, rtl);
3358 tempreg = convert_to_mode (GET_MODE (parmreg), tempreg, unsigned_p);
3359 emit_move_insn (MEM_P (parmreg) ? copy_rtx (parmreg) : parmreg,
3360 tempreg);
3361 all->first_conversion_insn = get_insns ();
3362 all->last_conversion_insn = get_last_insn ();
3363 end_sequence ();
3365 did_conversion = true;
3367 else
3368 emit_move_insn (MEM_P (parmreg) ? copy_rtx (parmreg) : parmreg, rtl);
3370 rtl = parmreg;
3372 /* STACK_PARM is the pointer, not the parm, and PARMREG is
3373 now the parm. */
3374 data->stack_parm = NULL;
3377 set_parm_rtl (parm, rtl);
3379 /* Mark the register as eliminable if we did no conversion and it was
3380 copied from memory at a fixed offset, and the arg pointer was not
3381 copied to a pseudo-reg. If the arg pointer is a pseudo reg or the
3382 offset formed an invalid address, such memory-equivalences as we
3383 make here would screw up life analysis for it. */
3384 if (data->nominal_mode == data->passed_mode
3385 && !did_conversion
3386 && data->stack_parm != 0
3387 && MEM_P (data->stack_parm)
3388 && data->locate.offset.var == 0
3389 && reg_mentioned_p (virtual_incoming_args_rtx,
3390 XEXP (data->stack_parm, 0)))
3392 rtx_insn *linsn = get_last_insn ();
3393 rtx_insn *sinsn;
3394 rtx set;
3396 /* Mark complex types separately. */
3397 if (GET_CODE (parmreg) == CONCAT)
3399 scalar_mode submode = GET_MODE_INNER (GET_MODE (parmreg));
3400 int regnor = REGNO (XEXP (parmreg, 0));
3401 int regnoi = REGNO (XEXP (parmreg, 1));
3402 rtx stackr = adjust_address_nv (data->stack_parm, submode, 0);
3403 rtx stacki = adjust_address_nv (data->stack_parm, submode,
3404 GET_MODE_SIZE (submode));
3406 /* Scan backwards for the set of the real and
3407 imaginary parts. */
3408 for (sinsn = linsn; sinsn != 0;
3409 sinsn = prev_nonnote_insn (sinsn))
3411 set = single_set (sinsn);
3412 if (set == 0)
3413 continue;
3415 if (SET_DEST (set) == regno_reg_rtx [regnoi])
3416 set_unique_reg_note (sinsn, REG_EQUIV, stacki);
3417 else if (SET_DEST (set) == regno_reg_rtx [regnor])
3418 set_unique_reg_note (sinsn, REG_EQUIV, stackr);
3421 else
3422 set_dst_reg_note (linsn, REG_EQUIV, equiv_stack_parm, parmreg);
3425 /* For pointer data type, suggest pointer register. */
3426 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3427 mark_reg_pointer (parmreg,
3428 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
3431 /* A subroutine of assign_parms. Allocate stack space to hold the current
3432 parameter. Get it there. Perform all ABI specified conversions. */
3434 static void
3435 assign_parm_setup_stack (struct assign_parm_data_all *all, tree parm,
3436 struct assign_parm_data_one *data)
3438 /* Value must be stored in the stack slot STACK_PARM during function
3439 execution. */
3440 bool to_conversion = false;
3442 assign_parm_remove_parallels (data);
3444 if (data->promoted_mode != data->nominal_mode)
3446 /* Conversion is required. */
3447 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
3449 emit_move_insn (tempreg, validize_mem (copy_rtx (data->entry_parm)));
3451 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3452 to_conversion = true;
3454 data->entry_parm = convert_to_mode (data->nominal_mode, tempreg,
3455 TYPE_UNSIGNED (TREE_TYPE (parm)));
3457 if (data->stack_parm)
3459 poly_int64 offset
3460 = subreg_lowpart_offset (data->nominal_mode,
3461 GET_MODE (data->stack_parm));
3462 /* ??? This may need a big-endian conversion on sparc64. */
3463 data->stack_parm
3464 = adjust_address (data->stack_parm, data->nominal_mode, 0);
3465 if (maybe_ne (offset, 0) && MEM_OFFSET_KNOWN_P (data->stack_parm))
3466 set_mem_offset (data->stack_parm,
3467 MEM_OFFSET (data->stack_parm) + offset);
3471 if (data->entry_parm != data->stack_parm)
3473 rtx src, dest;
3475 if (data->stack_parm == 0)
3477 int align = STACK_SLOT_ALIGNMENT (data->passed_type,
3478 GET_MODE (data->entry_parm),
3479 TYPE_ALIGN (data->passed_type));
3480 data->stack_parm
3481 = assign_stack_local (GET_MODE (data->entry_parm),
3482 GET_MODE_SIZE (GET_MODE (data->entry_parm)),
3483 align);
3484 set_mem_attributes (data->stack_parm, parm, 1);
3487 dest = validize_mem (copy_rtx (data->stack_parm));
3488 src = validize_mem (copy_rtx (data->entry_parm));
3490 if (MEM_P (src))
3492 /* Use a block move to handle potentially misaligned entry_parm. */
3493 if (!to_conversion)
3494 push_to_sequence2 (all->first_conversion_insn,
3495 all->last_conversion_insn);
3496 to_conversion = true;
3498 emit_block_move (dest, src,
3499 GEN_INT (int_size_in_bytes (data->passed_type)),
3500 BLOCK_OP_NORMAL);
3502 else
3504 if (!REG_P (src))
3505 src = force_reg (GET_MODE (src), src);
3506 emit_move_insn (dest, src);
3510 if (to_conversion)
3512 all->first_conversion_insn = get_insns ();
3513 all->last_conversion_insn = get_last_insn ();
3514 end_sequence ();
3517 set_parm_rtl (parm, data->stack_parm);
3520 /* A subroutine of assign_parms. If the ABI splits complex arguments, then
3521 undo the frobbing that we did in assign_parms_augmented_arg_list. */
3523 static void
3524 assign_parms_unsplit_complex (struct assign_parm_data_all *all,
3525 vec<tree> fnargs)
3527 tree parm;
3528 tree orig_fnargs = all->orig_fnargs;
3529 unsigned i = 0;
3531 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm), ++i)
3533 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
3534 && targetm.calls.split_complex_arg (TREE_TYPE (parm)))
3536 rtx tmp, real, imag;
3537 scalar_mode inner = GET_MODE_INNER (DECL_MODE (parm));
3539 real = DECL_RTL (fnargs[i]);
3540 imag = DECL_RTL (fnargs[i + 1]);
3541 if (inner != GET_MODE (real))
3543 real = gen_lowpart_SUBREG (inner, real);
3544 imag = gen_lowpart_SUBREG (inner, imag);
3547 if (TREE_ADDRESSABLE (parm))
3549 rtx rmem, imem;
3550 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (parm));
3551 int align = STACK_SLOT_ALIGNMENT (TREE_TYPE (parm),
3552 DECL_MODE (parm),
3553 TYPE_ALIGN (TREE_TYPE (parm)));
3555 /* split_complex_arg put the real and imag parts in
3556 pseudos. Move them to memory. */
3557 tmp = assign_stack_local (DECL_MODE (parm), size, align);
3558 set_mem_attributes (tmp, parm, 1);
3559 rmem = adjust_address_nv (tmp, inner, 0);
3560 imem = adjust_address_nv (tmp, inner, GET_MODE_SIZE (inner));
3561 push_to_sequence2 (all->first_conversion_insn,
3562 all->last_conversion_insn);
3563 emit_move_insn (rmem, real);
3564 emit_move_insn (imem, imag);
3565 all->first_conversion_insn = get_insns ();
3566 all->last_conversion_insn = get_last_insn ();
3567 end_sequence ();
3569 else
3570 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
3571 set_parm_rtl (parm, tmp);
3573 real = DECL_INCOMING_RTL (fnargs[i]);
3574 imag = DECL_INCOMING_RTL (fnargs[i + 1]);
3575 if (inner != GET_MODE (real))
3577 real = gen_lowpart_SUBREG (inner, real);
3578 imag = gen_lowpart_SUBREG (inner, imag);
3580 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
3581 set_decl_incoming_rtl (parm, tmp, false);
3582 i++;
3587 /* Assign RTL expressions to the function's parameters. This may involve
3588 copying them into registers and using those registers as the DECL_RTL. */
3590 static void
3591 assign_parms (tree fndecl)
3593 struct assign_parm_data_all all;
3594 tree parm;
3595 vec<tree> fnargs;
3596 unsigned i;
3598 crtl->args.internal_arg_pointer
3599 = targetm.calls.internal_arg_pointer ();
3601 assign_parms_initialize_all (&all);
3602 fnargs = assign_parms_augmented_arg_list (&all);
3604 FOR_EACH_VEC_ELT (fnargs, i, parm)
3606 struct assign_parm_data_one data;
3608 /* Extract the type of PARM; adjust it according to ABI. */
3609 assign_parm_find_data_types (&all, parm, &data);
3611 /* Early out for errors and void parameters. */
3612 if (data.passed_mode == VOIDmode)
3614 SET_DECL_RTL (parm, const0_rtx);
3615 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
3616 continue;
3619 /* Estimate stack alignment from parameter alignment. */
3620 if (SUPPORTS_STACK_ALIGNMENT)
3622 unsigned int align
3623 = targetm.calls.function_arg_boundary (data.promoted_mode,
3624 data.passed_type);
3625 align = MINIMUM_ALIGNMENT (data.passed_type, data.promoted_mode,
3626 align);
3627 if (TYPE_ALIGN (data.nominal_type) > align)
3628 align = MINIMUM_ALIGNMENT (data.nominal_type,
3629 TYPE_MODE (data.nominal_type),
3630 TYPE_ALIGN (data.nominal_type));
3631 if (crtl->stack_alignment_estimated < align)
3633 gcc_assert (!crtl->stack_realign_processed);
3634 crtl->stack_alignment_estimated = align;
3638 /* Find out where the parameter arrives in this function. */
3639 assign_parm_find_entry_rtl (&all, &data);
3641 /* Find out where stack space for this parameter might be. */
3642 if (assign_parm_is_stack_parm (&all, &data))
3644 assign_parm_find_stack_rtl (parm, &data);
3645 assign_parm_adjust_entry_rtl (&data);
3647 /* Record permanently how this parm was passed. */
3648 if (data.passed_pointer)
3650 rtx incoming_rtl
3651 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data.passed_type)),
3652 data.entry_parm);
3653 set_decl_incoming_rtl (parm, incoming_rtl, true);
3655 else
3656 set_decl_incoming_rtl (parm, data.entry_parm, false);
3658 assign_parm_adjust_stack_rtl (&data);
3660 if (assign_parm_setup_block_p (&data))
3661 assign_parm_setup_block (&all, parm, &data);
3662 else if (data.passed_pointer || use_register_for_decl (parm))
3663 assign_parm_setup_reg (&all, parm, &data);
3664 else
3665 assign_parm_setup_stack (&all, parm, &data);
3667 if (cfun->stdarg && !DECL_CHAIN (parm))
3668 assign_parms_setup_varargs (&all, &data, false);
3670 /* Update info on where next arg arrives in registers. */
3671 targetm.calls.function_arg_advance (all.args_so_far, data.promoted_mode,
3672 data.passed_type, data.named_arg);
3675 if (targetm.calls.split_complex_arg)
3676 assign_parms_unsplit_complex (&all, fnargs);
3678 fnargs.release ();
3680 /* Output all parameter conversion instructions (possibly including calls)
3681 now that all parameters have been copied out of hard registers. */
3682 emit_insn (all.first_conversion_insn);
3684 /* Estimate reload stack alignment from scalar return mode. */
3685 if (SUPPORTS_STACK_ALIGNMENT)
3687 if (DECL_RESULT (fndecl))
3689 tree type = TREE_TYPE (DECL_RESULT (fndecl));
3690 machine_mode mode = TYPE_MODE (type);
3692 if (mode != BLKmode
3693 && mode != VOIDmode
3694 && !AGGREGATE_TYPE_P (type))
3696 unsigned int align = GET_MODE_ALIGNMENT (mode);
3697 if (crtl->stack_alignment_estimated < align)
3699 gcc_assert (!crtl->stack_realign_processed);
3700 crtl->stack_alignment_estimated = align;
3706 /* If we are receiving a struct value address as the first argument, set up
3707 the RTL for the function result. As this might require code to convert
3708 the transmitted address to Pmode, we do this here to ensure that possible
3709 preliminary conversions of the address have been emitted already. */
3710 if (all.function_result_decl)
3712 tree result = DECL_RESULT (current_function_decl);
3713 rtx addr = DECL_RTL (all.function_result_decl);
3714 rtx x;
3716 if (DECL_BY_REFERENCE (result))
3718 SET_DECL_VALUE_EXPR (result, all.function_result_decl);
3719 x = addr;
3721 else
3723 SET_DECL_VALUE_EXPR (result,
3724 build1 (INDIRECT_REF, TREE_TYPE (result),
3725 all.function_result_decl));
3726 addr = convert_memory_address (Pmode, addr);
3727 x = gen_rtx_MEM (DECL_MODE (result), addr);
3728 set_mem_attributes (x, result, 1);
3731 DECL_HAS_VALUE_EXPR_P (result) = 1;
3733 set_parm_rtl (result, x);
3736 /* We have aligned all the args, so add space for the pretend args. */
3737 crtl->args.pretend_args_size = all.pretend_args_size;
3738 all.stack_args_size.constant += all.extra_pretend_bytes;
3739 crtl->args.size = all.stack_args_size.constant;
3741 /* Adjust function incoming argument size for alignment and
3742 minimum length. */
3744 crtl->args.size = upper_bound (crtl->args.size, all.reg_parm_stack_space);
3745 crtl->args.size = aligned_upper_bound (crtl->args.size,
3746 PARM_BOUNDARY / BITS_PER_UNIT);
3748 if (ARGS_GROW_DOWNWARD)
3750 crtl->args.arg_offset_rtx
3751 = (all.stack_args_size.var == 0
3752 ? gen_int_mode (-all.stack_args_size.constant, Pmode)
3753 : expand_expr (size_diffop (all.stack_args_size.var,
3754 size_int (-all.stack_args_size.constant)),
3755 NULL_RTX, VOIDmode, EXPAND_NORMAL));
3757 else
3758 crtl->args.arg_offset_rtx = ARGS_SIZE_RTX (all.stack_args_size);
3760 /* See how many bytes, if any, of its args a function should try to pop
3761 on return. */
3763 crtl->args.pops_args = targetm.calls.return_pops_args (fndecl,
3764 TREE_TYPE (fndecl),
3765 crtl->args.size);
3767 /* For stdarg.h function, save info about
3768 regs and stack space used by the named args. */
3770 crtl->args.info = all.args_so_far_v;
3772 /* Set the rtx used for the function return value. Put this in its
3773 own variable so any optimizers that need this information don't have
3774 to include tree.h. Do this here so it gets done when an inlined
3775 function gets output. */
3777 crtl->return_rtx
3778 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
3779 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
3781 /* If scalar return value was computed in a pseudo-reg, or was a named
3782 return value that got dumped to the stack, copy that to the hard
3783 return register. */
3784 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
3786 tree decl_result = DECL_RESULT (fndecl);
3787 rtx decl_rtl = DECL_RTL (decl_result);
3789 if (REG_P (decl_rtl)
3790 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
3791 : DECL_REGISTER (decl_result))
3793 rtx real_decl_rtl;
3795 real_decl_rtl = targetm.calls.function_value (TREE_TYPE (decl_result),
3796 fndecl, true);
3797 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
3798 /* The delay slot scheduler assumes that crtl->return_rtx
3799 holds the hard register containing the return value, not a
3800 temporary pseudo. */
3801 crtl->return_rtx = real_decl_rtl;
3806 /* A subroutine of gimplify_parameters, invoked via walk_tree.
3807 For all seen types, gimplify their sizes. */
3809 static tree
3810 gimplify_parm_type (tree *tp, int *walk_subtrees, void *data)
3812 tree t = *tp;
3814 *walk_subtrees = 0;
3815 if (TYPE_P (t))
3817 if (POINTER_TYPE_P (t))
3818 *walk_subtrees = 1;
3819 else if (TYPE_SIZE (t) && !TREE_CONSTANT (TYPE_SIZE (t))
3820 && !TYPE_SIZES_GIMPLIFIED (t))
3822 gimplify_type_sizes (t, (gimple_seq *) data);
3823 *walk_subtrees = 1;
3827 return NULL;
3830 /* Gimplify the parameter list for current_function_decl. This involves
3831 evaluating SAVE_EXPRs of variable sized parameters and generating code
3832 to implement callee-copies reference parameters. Returns a sequence of
3833 statements to add to the beginning of the function. */
3835 gimple_seq
3836 gimplify_parameters (gimple_seq *cleanup)
3838 struct assign_parm_data_all all;
3839 tree parm;
3840 gimple_seq stmts = NULL;
3841 vec<tree> fnargs;
3842 unsigned i;
3844 assign_parms_initialize_all (&all);
3845 fnargs = assign_parms_augmented_arg_list (&all);
3847 FOR_EACH_VEC_ELT (fnargs, i, parm)
3849 struct assign_parm_data_one data;
3851 /* Extract the type of PARM; adjust it according to ABI. */
3852 assign_parm_find_data_types (&all, parm, &data);
3854 /* Early out for errors and void parameters. */
3855 if (data.passed_mode == VOIDmode || DECL_SIZE (parm) == NULL)
3856 continue;
3858 /* Update info on where next arg arrives in registers. */
3859 targetm.calls.function_arg_advance (all.args_so_far, data.promoted_mode,
3860 data.passed_type, data.named_arg);
3862 /* ??? Once upon a time variable_size stuffed parameter list
3863 SAVE_EXPRs (amongst others) onto a pending sizes list. This
3864 turned out to be less than manageable in the gimple world.
3865 Now we have to hunt them down ourselves. */
3866 walk_tree_without_duplicates (&data.passed_type,
3867 gimplify_parm_type, &stmts);
3869 if (TREE_CODE (DECL_SIZE_UNIT (parm)) != INTEGER_CST)
3871 gimplify_one_sizepos (&DECL_SIZE (parm), &stmts);
3872 gimplify_one_sizepos (&DECL_SIZE_UNIT (parm), &stmts);
3875 if (data.passed_pointer)
3877 tree type = TREE_TYPE (data.passed_type);
3878 if (reference_callee_copied (&all.args_so_far_v, TYPE_MODE (type),
3879 type, data.named_arg))
3881 tree local, t;
3883 /* For constant-sized objects, this is trivial; for
3884 variable-sized objects, we have to play games. */
3885 if (TREE_CODE (DECL_SIZE_UNIT (parm)) == INTEGER_CST
3886 && !(flag_stack_check == GENERIC_STACK_CHECK
3887 && compare_tree_int (DECL_SIZE_UNIT (parm),
3888 STACK_CHECK_MAX_VAR_SIZE) > 0))
3890 local = create_tmp_var (type, get_name (parm));
3891 DECL_IGNORED_P (local) = 0;
3892 /* If PARM was addressable, move that flag over
3893 to the local copy, as its address will be taken,
3894 not the PARMs. Keep the parms address taken
3895 as we'll query that flag during gimplification. */
3896 if (TREE_ADDRESSABLE (parm))
3897 TREE_ADDRESSABLE (local) = 1;
3898 else if (TREE_CODE (type) == COMPLEX_TYPE
3899 || TREE_CODE (type) == VECTOR_TYPE)
3900 DECL_GIMPLE_REG_P (local) = 1;
3902 if (!is_gimple_reg (local)
3903 && flag_stack_reuse != SR_NONE)
3905 tree clobber = build_constructor (type, NULL);
3906 gimple *clobber_stmt;
3907 TREE_THIS_VOLATILE (clobber) = 1;
3908 clobber_stmt = gimple_build_assign (local, clobber);
3909 gimple_seq_add_stmt (cleanup, clobber_stmt);
3912 else
3914 tree ptr_type, addr;
3916 ptr_type = build_pointer_type (type);
3917 addr = create_tmp_reg (ptr_type, get_name (parm));
3918 DECL_IGNORED_P (addr) = 0;
3919 local = build_fold_indirect_ref (addr);
3921 t = build_alloca_call_expr (DECL_SIZE_UNIT (parm),
3922 DECL_ALIGN (parm),
3923 max_int_size_in_bytes (type));
3924 /* The call has been built for a variable-sized object. */
3925 CALL_ALLOCA_FOR_VAR_P (t) = 1;
3926 t = fold_convert (ptr_type, t);
3927 t = build2 (MODIFY_EXPR, TREE_TYPE (addr), addr, t);
3928 gimplify_and_add (t, &stmts);
3931 gimplify_assign (local, parm, &stmts);
3933 SET_DECL_VALUE_EXPR (parm, local);
3934 DECL_HAS_VALUE_EXPR_P (parm) = 1;
3939 fnargs.release ();
3941 return stmts;
3944 /* Compute the size and offset from the start of the stacked arguments for a
3945 parm passed in mode PASSED_MODE and with type TYPE.
3947 INITIAL_OFFSET_PTR points to the current offset into the stacked
3948 arguments.
3950 The starting offset and size for this parm are returned in
3951 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
3952 nonzero, the offset is that of stack slot, which is returned in
3953 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
3954 padding required from the initial offset ptr to the stack slot.
3956 IN_REGS is nonzero if the argument will be passed in registers. It will
3957 never be set if REG_PARM_STACK_SPACE is not defined.
3959 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
3960 for arguments which are passed in registers.
3962 FNDECL is the function in which the argument was defined.
3964 There are two types of rounding that are done. The first, controlled by
3965 TARGET_FUNCTION_ARG_BOUNDARY, forces the offset from the start of the
3966 argument list to be aligned to the specific boundary (in bits). This
3967 rounding affects the initial and starting offsets, but not the argument
3968 size.
3970 The second, controlled by TARGET_FUNCTION_ARG_PADDING and PARM_BOUNDARY,
3971 optionally rounds the size of the parm to PARM_BOUNDARY. The
3972 initial offset is not affected by this rounding, while the size always
3973 is and the starting offset may be. */
3975 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
3976 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
3977 callers pass in the total size of args so far as
3978 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
3980 void
3981 locate_and_pad_parm (machine_mode passed_mode, tree type, int in_regs,
3982 int reg_parm_stack_space, int partial,
3983 tree fndecl ATTRIBUTE_UNUSED,
3984 struct args_size *initial_offset_ptr,
3985 struct locate_and_pad_arg_data *locate)
3987 tree sizetree;
3988 pad_direction where_pad;
3989 unsigned int boundary, round_boundary;
3990 int part_size_in_regs;
3992 /* If we have found a stack parm before we reach the end of the
3993 area reserved for registers, skip that area. */
3994 if (! in_regs)
3996 if (reg_parm_stack_space > 0)
3998 if (initial_offset_ptr->var
3999 || !ordered_p (initial_offset_ptr->constant,
4000 reg_parm_stack_space))
4002 initial_offset_ptr->var
4003 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
4004 ssize_int (reg_parm_stack_space));
4005 initial_offset_ptr->constant = 0;
4007 else
4008 initial_offset_ptr->constant
4009 = ordered_max (initial_offset_ptr->constant,
4010 reg_parm_stack_space);
4014 part_size_in_regs = (reg_parm_stack_space == 0 ? partial : 0);
4016 sizetree = (type
4017 ? arg_size_in_bytes (type)
4018 : size_int (GET_MODE_SIZE (passed_mode)));
4019 where_pad = targetm.calls.function_arg_padding (passed_mode, type);
4020 boundary = targetm.calls.function_arg_boundary (passed_mode, type);
4021 round_boundary = targetm.calls.function_arg_round_boundary (passed_mode,
4022 type);
4023 locate->where_pad = where_pad;
4025 /* Alignment can't exceed MAX_SUPPORTED_STACK_ALIGNMENT. */
4026 if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
4027 boundary = MAX_SUPPORTED_STACK_ALIGNMENT;
4029 locate->boundary = boundary;
4031 if (SUPPORTS_STACK_ALIGNMENT)
4033 /* stack_alignment_estimated can't change after stack has been
4034 realigned. */
4035 if (crtl->stack_alignment_estimated < boundary)
4037 if (!crtl->stack_realign_processed)
4038 crtl->stack_alignment_estimated = boundary;
4039 else
4041 /* If stack is realigned and stack alignment value
4042 hasn't been finalized, it is OK not to increase
4043 stack_alignment_estimated. The bigger alignment
4044 requirement is recorded in stack_alignment_needed
4045 below. */
4046 gcc_assert (!crtl->stack_realign_finalized
4047 && crtl->stack_realign_needed);
4052 /* Remember if the outgoing parameter requires extra alignment on the
4053 calling function side. */
4054 if (crtl->stack_alignment_needed < boundary)
4055 crtl->stack_alignment_needed = boundary;
4056 if (crtl->preferred_stack_boundary < boundary)
4057 crtl->preferred_stack_boundary = boundary;
4059 if (ARGS_GROW_DOWNWARD)
4061 locate->slot_offset.constant = -initial_offset_ptr->constant;
4062 if (initial_offset_ptr->var)
4063 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
4064 initial_offset_ptr->var);
4067 tree s2 = sizetree;
4068 if (where_pad != PAD_NONE
4069 && (!tree_fits_uhwi_p (sizetree)
4070 || (tree_to_uhwi (sizetree) * BITS_PER_UNIT) % round_boundary))
4071 s2 = round_up (s2, round_boundary / BITS_PER_UNIT);
4072 SUB_PARM_SIZE (locate->slot_offset, s2);
4075 locate->slot_offset.constant += part_size_in_regs;
4077 if (!in_regs || reg_parm_stack_space > 0)
4078 pad_to_arg_alignment (&locate->slot_offset, boundary,
4079 &locate->alignment_pad);
4081 locate->size.constant = (-initial_offset_ptr->constant
4082 - locate->slot_offset.constant);
4083 if (initial_offset_ptr->var)
4084 locate->size.var = size_binop (MINUS_EXPR,
4085 size_binop (MINUS_EXPR,
4086 ssize_int (0),
4087 initial_offset_ptr->var),
4088 locate->slot_offset.var);
4090 /* Pad_below needs the pre-rounded size to know how much to pad
4091 below. */
4092 locate->offset = locate->slot_offset;
4093 if (where_pad == PAD_DOWNWARD)
4094 pad_below (&locate->offset, passed_mode, sizetree);
4097 else
4099 if (!in_regs || reg_parm_stack_space > 0)
4100 pad_to_arg_alignment (initial_offset_ptr, boundary,
4101 &locate->alignment_pad);
4102 locate->slot_offset = *initial_offset_ptr;
4104 #ifdef PUSH_ROUNDING
4105 if (passed_mode != BLKmode)
4106 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
4107 #endif
4109 /* Pad_below needs the pre-rounded size to know how much to pad below
4110 so this must be done before rounding up. */
4111 locate->offset = locate->slot_offset;
4112 if (where_pad == PAD_DOWNWARD)
4113 pad_below (&locate->offset, passed_mode, sizetree);
4115 if (where_pad != PAD_NONE
4116 && (!tree_fits_uhwi_p (sizetree)
4117 || (tree_to_uhwi (sizetree) * BITS_PER_UNIT) % round_boundary))
4118 sizetree = round_up (sizetree, round_boundary / BITS_PER_UNIT);
4120 ADD_PARM_SIZE (locate->size, sizetree);
4122 locate->size.constant -= part_size_in_regs;
4125 locate->offset.constant
4126 += targetm.calls.function_arg_offset (passed_mode, type);
4129 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
4130 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
4132 static void
4133 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
4134 struct args_size *alignment_pad)
4136 tree save_var = NULL_TREE;
4137 poly_int64 save_constant = 0;
4138 int boundary_in_bytes = boundary / BITS_PER_UNIT;
4139 poly_int64 sp_offset = STACK_POINTER_OFFSET;
4141 #ifdef SPARC_STACK_BOUNDARY_HACK
4142 /* ??? The SPARC port may claim a STACK_BOUNDARY higher than
4143 the real alignment of %sp. However, when it does this, the
4144 alignment of %sp+STACK_POINTER_OFFSET is STACK_BOUNDARY. */
4145 if (SPARC_STACK_BOUNDARY_HACK)
4146 sp_offset = 0;
4147 #endif
4149 if (boundary > PARM_BOUNDARY)
4151 save_var = offset_ptr->var;
4152 save_constant = offset_ptr->constant;
4155 alignment_pad->var = NULL_TREE;
4156 alignment_pad->constant = 0;
4158 if (boundary > BITS_PER_UNIT)
4160 int misalign;
4161 if (offset_ptr->var
4162 || !known_misalignment (offset_ptr->constant + sp_offset,
4163 boundary_in_bytes, &misalign))
4165 tree sp_offset_tree = ssize_int (sp_offset);
4166 tree offset = size_binop (PLUS_EXPR,
4167 ARGS_SIZE_TREE (*offset_ptr),
4168 sp_offset_tree);
4169 tree rounded;
4170 if (ARGS_GROW_DOWNWARD)
4171 rounded = round_down (offset, boundary / BITS_PER_UNIT);
4172 else
4173 rounded = round_up (offset, boundary / BITS_PER_UNIT);
4175 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
4176 /* ARGS_SIZE_TREE includes constant term. */
4177 offset_ptr->constant = 0;
4178 if (boundary > PARM_BOUNDARY)
4179 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
4180 save_var);
4182 else
4184 if (ARGS_GROW_DOWNWARD)
4185 offset_ptr->constant -= misalign;
4186 else
4187 offset_ptr->constant += -misalign & (boundary_in_bytes - 1);
4189 if (boundary > PARM_BOUNDARY)
4190 alignment_pad->constant = offset_ptr->constant - save_constant;
4195 static void
4196 pad_below (struct args_size *offset_ptr, machine_mode passed_mode, tree sizetree)
4198 unsigned int align = PARM_BOUNDARY / BITS_PER_UNIT;
4199 int misalign;
4200 if (passed_mode != BLKmode
4201 && known_misalignment (GET_MODE_SIZE (passed_mode), align, &misalign))
4202 offset_ptr->constant += -misalign & (align - 1);
4203 else
4205 if (TREE_CODE (sizetree) != INTEGER_CST
4206 || (TREE_INT_CST_LOW (sizetree) & (align - 1)) != 0)
4208 /* Round the size up to multiple of PARM_BOUNDARY bits. */
4209 tree s2 = round_up (sizetree, align);
4210 /* Add it in. */
4211 ADD_PARM_SIZE (*offset_ptr, s2);
4212 SUB_PARM_SIZE (*offset_ptr, sizetree);
4218 /* True if register REGNO was alive at a place where `setjmp' was
4219 called and was set more than once or is an argument. Such regs may
4220 be clobbered by `longjmp'. */
4222 static bool
4223 regno_clobbered_at_setjmp (bitmap setjmp_crosses, int regno)
4225 /* There appear to be cases where some local vars never reach the
4226 backend but have bogus regnos. */
4227 if (regno >= max_reg_num ())
4228 return false;
4230 return ((REG_N_SETS (regno) > 1
4231 || REGNO_REG_SET_P (df_get_live_out (ENTRY_BLOCK_PTR_FOR_FN (cfun)),
4232 regno))
4233 && REGNO_REG_SET_P (setjmp_crosses, regno));
4236 /* Walk the tree of blocks describing the binding levels within a
4237 function and warn about variables the might be killed by setjmp or
4238 vfork. This is done after calling flow_analysis before register
4239 allocation since that will clobber the pseudo-regs to hard
4240 regs. */
4242 static void
4243 setjmp_vars_warning (bitmap setjmp_crosses, tree block)
4245 tree decl, sub;
4247 for (decl = BLOCK_VARS (block); decl; decl = DECL_CHAIN (decl))
4249 if (VAR_P (decl)
4250 && DECL_RTL_SET_P (decl)
4251 && REG_P (DECL_RTL (decl))
4252 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
4253 warning (OPT_Wclobbered, "variable %q+D might be clobbered by"
4254 " %<longjmp%> or %<vfork%>", decl);
4257 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = BLOCK_CHAIN (sub))
4258 setjmp_vars_warning (setjmp_crosses, sub);
4261 /* Do the appropriate part of setjmp_vars_warning
4262 but for arguments instead of local variables. */
4264 static void
4265 setjmp_args_warning (bitmap setjmp_crosses)
4267 tree decl;
4268 for (decl = DECL_ARGUMENTS (current_function_decl);
4269 decl; decl = DECL_CHAIN (decl))
4270 if (DECL_RTL (decl) != 0
4271 && REG_P (DECL_RTL (decl))
4272 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
4273 warning (OPT_Wclobbered,
4274 "argument %q+D might be clobbered by %<longjmp%> or %<vfork%>",
4275 decl);
4278 /* Generate warning messages for variables live across setjmp. */
4280 void
4281 generate_setjmp_warnings (void)
4283 bitmap setjmp_crosses = regstat_get_setjmp_crosses ();
4285 if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS
4286 || bitmap_empty_p (setjmp_crosses))
4287 return;
4289 setjmp_vars_warning (setjmp_crosses, DECL_INITIAL (current_function_decl));
4290 setjmp_args_warning (setjmp_crosses);
4294 /* Reverse the order of elements in the fragment chain T of blocks,
4295 and return the new head of the chain (old last element).
4296 In addition to that clear BLOCK_SAME_RANGE flags when needed
4297 and adjust BLOCK_SUPERCONTEXT from the super fragment to
4298 its super fragment origin. */
4300 static tree
4301 block_fragments_nreverse (tree t)
4303 tree prev = 0, block, next, prev_super = 0;
4304 tree super = BLOCK_SUPERCONTEXT (t);
4305 if (BLOCK_FRAGMENT_ORIGIN (super))
4306 super = BLOCK_FRAGMENT_ORIGIN (super);
4307 for (block = t; block; block = next)
4309 next = BLOCK_FRAGMENT_CHAIN (block);
4310 BLOCK_FRAGMENT_CHAIN (block) = prev;
4311 if ((prev && !BLOCK_SAME_RANGE (prev))
4312 || (BLOCK_FRAGMENT_CHAIN (BLOCK_SUPERCONTEXT (block))
4313 != prev_super))
4314 BLOCK_SAME_RANGE (block) = 0;
4315 prev_super = BLOCK_SUPERCONTEXT (block);
4316 BLOCK_SUPERCONTEXT (block) = super;
4317 prev = block;
4319 t = BLOCK_FRAGMENT_ORIGIN (t);
4320 if (BLOCK_FRAGMENT_CHAIN (BLOCK_SUPERCONTEXT (t))
4321 != prev_super)
4322 BLOCK_SAME_RANGE (t) = 0;
4323 BLOCK_SUPERCONTEXT (t) = super;
4324 return prev;
4327 /* Reverse the order of elements in the chain T of blocks,
4328 and return the new head of the chain (old last element).
4329 Also do the same on subblocks and reverse the order of elements
4330 in BLOCK_FRAGMENT_CHAIN as well. */
4332 static tree
4333 blocks_nreverse_all (tree t)
4335 tree prev = 0, block, next;
4336 for (block = t; block; block = next)
4338 next = BLOCK_CHAIN (block);
4339 BLOCK_CHAIN (block) = prev;
4340 if (BLOCK_FRAGMENT_CHAIN (block)
4341 && BLOCK_FRAGMENT_ORIGIN (block) == NULL_TREE)
4343 BLOCK_FRAGMENT_CHAIN (block)
4344 = block_fragments_nreverse (BLOCK_FRAGMENT_CHAIN (block));
4345 if (!BLOCK_SAME_RANGE (BLOCK_FRAGMENT_CHAIN (block)))
4346 BLOCK_SAME_RANGE (block) = 0;
4348 BLOCK_SUBBLOCKS (block) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block));
4349 prev = block;
4351 return prev;
4355 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
4356 and create duplicate blocks. */
4357 /* ??? Need an option to either create block fragments or to create
4358 abstract origin duplicates of a source block. It really depends
4359 on what optimization has been performed. */
4361 void
4362 reorder_blocks (void)
4364 tree block = DECL_INITIAL (current_function_decl);
4366 if (block == NULL_TREE)
4367 return;
4369 auto_vec<tree, 10> block_stack;
4371 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
4372 clear_block_marks (block);
4374 /* Prune the old trees away, so that they don't get in the way. */
4375 BLOCK_SUBBLOCKS (block) = NULL_TREE;
4376 BLOCK_CHAIN (block) = NULL_TREE;
4378 /* Recreate the block tree from the note nesting. */
4379 reorder_blocks_1 (get_insns (), block, &block_stack);
4380 BLOCK_SUBBLOCKS (block) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block));
4383 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
4385 void
4386 clear_block_marks (tree block)
4388 while (block)
4390 TREE_ASM_WRITTEN (block) = 0;
4391 clear_block_marks (BLOCK_SUBBLOCKS (block));
4392 block = BLOCK_CHAIN (block);
4396 static void
4397 reorder_blocks_1 (rtx_insn *insns, tree current_block,
4398 vec<tree> *p_block_stack)
4400 rtx_insn *insn;
4401 tree prev_beg = NULL_TREE, prev_end = NULL_TREE;
4403 for (insn = insns; insn; insn = NEXT_INSN (insn))
4405 if (NOTE_P (insn))
4407 if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_BEG)
4409 tree block = NOTE_BLOCK (insn);
4410 tree origin;
4412 gcc_assert (BLOCK_FRAGMENT_ORIGIN (block) == NULL_TREE);
4413 origin = block;
4415 if (prev_end)
4416 BLOCK_SAME_RANGE (prev_end) = 0;
4417 prev_end = NULL_TREE;
4419 /* If we have seen this block before, that means it now
4420 spans multiple address regions. Create a new fragment. */
4421 if (TREE_ASM_WRITTEN (block))
4423 tree new_block = copy_node (block);
4425 BLOCK_SAME_RANGE (new_block) = 0;
4426 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
4427 BLOCK_FRAGMENT_CHAIN (new_block)
4428 = BLOCK_FRAGMENT_CHAIN (origin);
4429 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
4431 NOTE_BLOCK (insn) = new_block;
4432 block = new_block;
4435 if (prev_beg == current_block && prev_beg)
4436 BLOCK_SAME_RANGE (block) = 1;
4438 prev_beg = origin;
4440 BLOCK_SUBBLOCKS (block) = 0;
4441 TREE_ASM_WRITTEN (block) = 1;
4442 /* When there's only one block for the entire function,
4443 current_block == block and we mustn't do this, it
4444 will cause infinite recursion. */
4445 if (block != current_block)
4447 tree super;
4448 if (block != origin)
4449 gcc_assert (BLOCK_SUPERCONTEXT (origin) == current_block
4450 || BLOCK_FRAGMENT_ORIGIN (BLOCK_SUPERCONTEXT
4451 (origin))
4452 == current_block);
4453 if (p_block_stack->is_empty ())
4454 super = current_block;
4455 else
4457 super = p_block_stack->last ();
4458 gcc_assert (super == current_block
4459 || BLOCK_FRAGMENT_ORIGIN (super)
4460 == current_block);
4462 BLOCK_SUPERCONTEXT (block) = super;
4463 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
4464 BLOCK_SUBBLOCKS (current_block) = block;
4465 current_block = origin;
4467 p_block_stack->safe_push (block);
4469 else if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_END)
4471 NOTE_BLOCK (insn) = p_block_stack->pop ();
4472 current_block = BLOCK_SUPERCONTEXT (current_block);
4473 if (BLOCK_FRAGMENT_ORIGIN (current_block))
4474 current_block = BLOCK_FRAGMENT_ORIGIN (current_block);
4475 prev_beg = NULL_TREE;
4476 prev_end = BLOCK_SAME_RANGE (NOTE_BLOCK (insn))
4477 ? NOTE_BLOCK (insn) : NULL_TREE;
4480 else
4482 prev_beg = NULL_TREE;
4483 if (prev_end)
4484 BLOCK_SAME_RANGE (prev_end) = 0;
4485 prev_end = NULL_TREE;
4490 /* Reverse the order of elements in the chain T of blocks,
4491 and return the new head of the chain (old last element). */
4493 tree
4494 blocks_nreverse (tree t)
4496 tree prev = 0, block, next;
4497 for (block = t; block; block = next)
4499 next = BLOCK_CHAIN (block);
4500 BLOCK_CHAIN (block) = prev;
4501 prev = block;
4503 return prev;
4506 /* Concatenate two chains of blocks (chained through BLOCK_CHAIN)
4507 by modifying the last node in chain 1 to point to chain 2. */
4509 tree
4510 block_chainon (tree op1, tree op2)
4512 tree t1;
4514 if (!op1)
4515 return op2;
4516 if (!op2)
4517 return op1;
4519 for (t1 = op1; BLOCK_CHAIN (t1); t1 = BLOCK_CHAIN (t1))
4520 continue;
4521 BLOCK_CHAIN (t1) = op2;
4523 #ifdef ENABLE_TREE_CHECKING
4525 tree t2;
4526 for (t2 = op2; t2; t2 = BLOCK_CHAIN (t2))
4527 gcc_assert (t2 != t1);
4529 #endif
4531 return op1;
4534 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
4535 non-NULL, list them all into VECTOR, in a depth-first preorder
4536 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
4537 blocks. */
4539 static int
4540 all_blocks (tree block, tree *vector)
4542 int n_blocks = 0;
4544 while (block)
4546 TREE_ASM_WRITTEN (block) = 0;
4548 /* Record this block. */
4549 if (vector)
4550 vector[n_blocks] = block;
4552 ++n_blocks;
4554 /* Record the subblocks, and their subblocks... */
4555 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
4556 vector ? vector + n_blocks : 0);
4557 block = BLOCK_CHAIN (block);
4560 return n_blocks;
4563 /* Return a vector containing all the blocks rooted at BLOCK. The
4564 number of elements in the vector is stored in N_BLOCKS_P. The
4565 vector is dynamically allocated; it is the caller's responsibility
4566 to call `free' on the pointer returned. */
4568 static tree *
4569 get_block_vector (tree block, int *n_blocks_p)
4571 tree *block_vector;
4573 *n_blocks_p = all_blocks (block, NULL);
4574 block_vector = XNEWVEC (tree, *n_blocks_p);
4575 all_blocks (block, block_vector);
4577 return block_vector;
4580 static GTY(()) int next_block_index = 2;
4582 /* Set BLOCK_NUMBER for all the blocks in FN. */
4584 void
4585 number_blocks (tree fn)
4587 int i;
4588 int n_blocks;
4589 tree *block_vector;
4591 /* For XCOFF debugging output, we start numbering the blocks
4592 from 1 within each function, rather than keeping a running
4593 count. */
4594 #if defined (XCOFF_DEBUGGING_INFO)
4595 if (write_symbols == XCOFF_DEBUG)
4596 next_block_index = 1;
4597 #endif
4599 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
4601 /* The top-level BLOCK isn't numbered at all. */
4602 for (i = 1; i < n_blocks; ++i)
4603 /* We number the blocks from two. */
4604 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
4606 free (block_vector);
4608 return;
4611 /* If VAR is present in a subblock of BLOCK, return the subblock. */
4613 DEBUG_FUNCTION tree
4614 debug_find_var_in_block_tree (tree var, tree block)
4616 tree t;
4618 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
4619 if (t == var)
4620 return block;
4622 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
4624 tree ret = debug_find_var_in_block_tree (var, t);
4625 if (ret)
4626 return ret;
4629 return NULL_TREE;
4632 /* Keep track of whether we're in a dummy function context. If we are,
4633 we don't want to invoke the set_current_function hook, because we'll
4634 get into trouble if the hook calls target_reinit () recursively or
4635 when the initial initialization is not yet complete. */
4637 static bool in_dummy_function;
4639 /* Invoke the target hook when setting cfun. Update the optimization options
4640 if the function uses different options than the default. */
4642 static void
4643 invoke_set_current_function_hook (tree fndecl)
4645 if (!in_dummy_function)
4647 tree opts = ((fndecl)
4648 ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (fndecl)
4649 : optimization_default_node);
4651 if (!opts)
4652 opts = optimization_default_node;
4654 /* Change optimization options if needed. */
4655 if (optimization_current_node != opts)
4657 optimization_current_node = opts;
4658 cl_optimization_restore (&global_options, TREE_OPTIMIZATION (opts));
4661 targetm.set_current_function (fndecl);
4662 this_fn_optabs = this_target_optabs;
4664 /* Initialize global alignment variables after op. */
4665 parse_alignment_opts ();
4667 if (opts != optimization_default_node)
4669 init_tree_optimization_optabs (opts);
4670 if (TREE_OPTIMIZATION_OPTABS (opts))
4671 this_fn_optabs = (struct target_optabs *)
4672 TREE_OPTIMIZATION_OPTABS (opts);
4677 /* cfun should never be set directly; use this function. */
4679 void
4680 set_cfun (struct function *new_cfun, bool force)
4682 if (cfun != new_cfun || force)
4684 cfun = new_cfun;
4685 invoke_set_current_function_hook (new_cfun ? new_cfun->decl : NULL_TREE);
4686 redirect_edge_var_map_empty ();
4690 /* Initialized with NOGC, making this poisonous to the garbage collector. */
4692 static vec<function *> cfun_stack;
4694 /* Push the current cfun onto the stack, and set cfun to new_cfun. Also set
4695 current_function_decl accordingly. */
4697 void
4698 push_cfun (struct function *new_cfun)
4700 gcc_assert ((!cfun && !current_function_decl)
4701 || (cfun && current_function_decl == cfun->decl));
4702 cfun_stack.safe_push (cfun);
4703 current_function_decl = new_cfun ? new_cfun->decl : NULL_TREE;
4704 set_cfun (new_cfun);
4707 /* Pop cfun from the stack. Also set current_function_decl accordingly. */
4709 void
4710 pop_cfun (void)
4712 struct function *new_cfun = cfun_stack.pop ();
4713 /* When in_dummy_function, we do have a cfun but current_function_decl is
4714 NULL. We also allow pushing NULL cfun and subsequently changing
4715 current_function_decl to something else and have both restored by
4716 pop_cfun. */
4717 gcc_checking_assert (in_dummy_function
4718 || !cfun
4719 || current_function_decl == cfun->decl);
4720 set_cfun (new_cfun);
4721 current_function_decl = new_cfun ? new_cfun->decl : NULL_TREE;
4724 /* Return value of funcdef and increase it. */
4726 get_next_funcdef_no (void)
4728 return funcdef_no++;
4731 /* Return value of funcdef. */
4733 get_last_funcdef_no (void)
4735 return funcdef_no;
4738 /* Allocate a function structure for FNDECL and set its contents
4739 to the defaults. Set cfun to the newly-allocated object.
4740 Some of the helper functions invoked during initialization assume
4741 that cfun has already been set. Therefore, assign the new object
4742 directly into cfun and invoke the back end hook explicitly at the
4743 very end, rather than initializing a temporary and calling set_cfun
4744 on it.
4746 ABSTRACT_P is true if this is a function that will never be seen by
4747 the middle-end. Such functions are front-end concepts (like C++
4748 function templates) that do not correspond directly to functions
4749 placed in object files. */
4751 void
4752 allocate_struct_function (tree fndecl, bool abstract_p)
4754 tree fntype = fndecl ? TREE_TYPE (fndecl) : NULL_TREE;
4756 cfun = ggc_cleared_alloc<function> ();
4758 init_eh_for_function ();
4760 if (init_machine_status)
4761 cfun->machine = (*init_machine_status) ();
4763 #ifdef OVERRIDE_ABI_FORMAT
4764 OVERRIDE_ABI_FORMAT (fndecl);
4765 #endif
4767 if (fndecl != NULL_TREE)
4769 DECL_STRUCT_FUNCTION (fndecl) = cfun;
4770 cfun->decl = fndecl;
4771 current_function_funcdef_no = get_next_funcdef_no ();
4774 invoke_set_current_function_hook (fndecl);
4776 if (fndecl != NULL_TREE)
4778 tree result = DECL_RESULT (fndecl);
4780 if (!abstract_p)
4782 /* Now that we have activated any function-specific attributes
4783 that might affect layout, particularly vector modes, relayout
4784 each of the parameters and the result. */
4785 relayout_decl (result);
4786 for (tree parm = DECL_ARGUMENTS (fndecl); parm;
4787 parm = DECL_CHAIN (parm))
4788 relayout_decl (parm);
4790 /* Similarly relayout the function decl. */
4791 targetm.target_option.relayout_function (fndecl);
4794 if (!abstract_p && aggregate_value_p (result, fndecl))
4796 #ifdef PCC_STATIC_STRUCT_RETURN
4797 cfun->returns_pcc_struct = 1;
4798 #endif
4799 cfun->returns_struct = 1;
4802 cfun->stdarg = stdarg_p (fntype);
4804 /* Assume all registers in stdarg functions need to be saved. */
4805 cfun->va_list_gpr_size = VA_LIST_MAX_GPR_SIZE;
4806 cfun->va_list_fpr_size = VA_LIST_MAX_FPR_SIZE;
4808 /* ??? This could be set on a per-function basis by the front-end
4809 but is this worth the hassle? */
4810 cfun->can_throw_non_call_exceptions = flag_non_call_exceptions;
4811 cfun->can_delete_dead_exceptions = flag_delete_dead_exceptions;
4813 if (!profile_flag && !flag_instrument_function_entry_exit)
4814 DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl) = 1;
4817 /* Don't enable begin stmt markers if var-tracking at assignments is
4818 disabled. The markers make little sense without the variable
4819 binding annotations among them. */
4820 cfun->debug_nonbind_markers = lang_hooks.emits_begin_stmt
4821 && MAY_HAVE_DEBUG_MARKER_STMTS;
4824 /* This is like allocate_struct_function, but pushes a new cfun for FNDECL
4825 instead of just setting it. */
4827 void
4828 push_struct_function (tree fndecl)
4830 /* When in_dummy_function we might be in the middle of a pop_cfun and
4831 current_function_decl and cfun may not match. */
4832 gcc_assert (in_dummy_function
4833 || (!cfun && !current_function_decl)
4834 || (cfun && current_function_decl == cfun->decl));
4835 cfun_stack.safe_push (cfun);
4836 current_function_decl = fndecl;
4837 allocate_struct_function (fndecl, false);
4840 /* Reset crtl and other non-struct-function variables to defaults as
4841 appropriate for emitting rtl at the start of a function. */
4843 static void
4844 prepare_function_start (void)
4846 gcc_assert (!get_last_insn ());
4847 init_temp_slots ();
4848 init_emit ();
4849 init_varasm_status ();
4850 init_expr ();
4851 default_rtl_profile ();
4853 if (flag_stack_usage_info)
4855 cfun->su = ggc_cleared_alloc<stack_usage> ();
4856 cfun->su->static_stack_size = -1;
4859 cse_not_expected = ! optimize;
4861 /* Caller save not needed yet. */
4862 caller_save_needed = 0;
4864 /* We haven't done register allocation yet. */
4865 reg_renumber = 0;
4867 /* Indicate that we have not instantiated virtual registers yet. */
4868 virtuals_instantiated = 0;
4870 /* Indicate that we want CONCATs now. */
4871 generating_concat_p = 1;
4873 /* Indicate we have no need of a frame pointer yet. */
4874 frame_pointer_needed = 0;
4877 void
4878 push_dummy_function (bool with_decl)
4880 tree fn_decl, fn_type, fn_result_decl;
4882 gcc_assert (!in_dummy_function);
4883 in_dummy_function = true;
4885 if (with_decl)
4887 fn_type = build_function_type_list (void_type_node, NULL_TREE);
4888 fn_decl = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL, NULL_TREE,
4889 fn_type);
4890 fn_result_decl = build_decl (UNKNOWN_LOCATION, RESULT_DECL,
4891 NULL_TREE, void_type_node);
4892 DECL_RESULT (fn_decl) = fn_result_decl;
4894 else
4895 fn_decl = NULL_TREE;
4897 push_struct_function (fn_decl);
4900 /* Initialize the rtl expansion mechanism so that we can do simple things
4901 like generate sequences. This is used to provide a context during global
4902 initialization of some passes. You must call expand_dummy_function_end
4903 to exit this context. */
4905 void
4906 init_dummy_function_start (void)
4908 push_dummy_function (false);
4909 prepare_function_start ();
4912 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
4913 and initialize static variables for generating RTL for the statements
4914 of the function. */
4916 void
4917 init_function_start (tree subr)
4919 /* Initialize backend, if needed. */
4920 initialize_rtl ();
4922 prepare_function_start ();
4923 decide_function_section (subr);
4925 /* Warn if this value is an aggregate type,
4926 regardless of which calling convention we are using for it. */
4927 if (AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
4928 warning (OPT_Waggregate_return, "function returns an aggregate");
4931 /* Expand code to verify the stack_protect_guard. This is invoked at
4932 the end of a function to be protected. */
4934 void
4935 stack_protect_epilogue (void)
4937 tree guard_decl = targetm.stack_protect_guard ();
4938 rtx_code_label *label = gen_label_rtx ();
4939 rtx x, y;
4940 rtx_insn *seq;
4942 x = expand_normal (crtl->stack_protect_guard);
4943 if (guard_decl)
4944 y = expand_normal (guard_decl);
4945 else
4946 y = const0_rtx;
4948 /* Allow the target to compare Y with X without leaking either into
4949 a register. */
4950 if (targetm.have_stack_protect_test ()
4951 && ((seq = targetm.gen_stack_protect_test (x, y, label)) != NULL_RTX))
4952 emit_insn (seq);
4953 else
4954 emit_cmp_and_jump_insns (x, y, EQ, NULL_RTX, ptr_mode, 1, label);
4956 /* The noreturn predictor has been moved to the tree level. The rtl-level
4957 predictors estimate this branch about 20%, which isn't enough to get
4958 things moved out of line. Since this is the only extant case of adding
4959 a noreturn function at the rtl level, it doesn't seem worth doing ought
4960 except adding the prediction by hand. */
4961 rtx_insn *tmp = get_last_insn ();
4962 if (JUMP_P (tmp))
4963 predict_insn_def (tmp, PRED_NORETURN, TAKEN);
4965 expand_call (targetm.stack_protect_fail (), NULL_RTX, /*ignore=*/true);
4966 free_temp_slots ();
4967 emit_label (label);
4970 /* Start the RTL for a new function, and set variables used for
4971 emitting RTL.
4972 SUBR is the FUNCTION_DECL node.
4973 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
4974 the function's parameters, which must be run at any return statement. */
4976 void
4977 expand_function_start (tree subr)
4979 /* Make sure volatile mem refs aren't considered
4980 valid operands of arithmetic insns. */
4981 init_recog_no_volatile ();
4983 crtl->profile
4984 = (profile_flag
4985 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
4987 crtl->limit_stack
4988 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
4990 /* Make the label for return statements to jump to. Do not special
4991 case machines with special return instructions -- they will be
4992 handled later during jump, ifcvt, or epilogue creation. */
4993 return_label = gen_label_rtx ();
4995 /* Initialize rtx used to return the value. */
4996 /* Do this before assign_parms so that we copy the struct value address
4997 before any library calls that assign parms might generate. */
4999 /* Decide whether to return the value in memory or in a register. */
5000 tree res = DECL_RESULT (subr);
5001 if (aggregate_value_p (res, subr))
5003 /* Returning something that won't go in a register. */
5004 rtx value_address = 0;
5006 #ifdef PCC_STATIC_STRUCT_RETURN
5007 if (cfun->returns_pcc_struct)
5009 int size = int_size_in_bytes (TREE_TYPE (res));
5010 value_address = assemble_static_space (size);
5012 else
5013 #endif
5015 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 2);
5016 /* Expect to be passed the address of a place to store the value.
5017 If it is passed as an argument, assign_parms will take care of
5018 it. */
5019 if (sv)
5021 value_address = gen_reg_rtx (Pmode);
5022 emit_move_insn (value_address, sv);
5025 if (value_address)
5027 rtx x = value_address;
5028 if (!DECL_BY_REFERENCE (res))
5030 x = gen_rtx_MEM (DECL_MODE (res), x);
5031 set_mem_attributes (x, res, 1);
5033 set_parm_rtl (res, x);
5036 else if (DECL_MODE (res) == VOIDmode)
5037 /* If return mode is void, this decl rtl should not be used. */
5038 set_parm_rtl (res, NULL_RTX);
5039 else
5041 /* Compute the return values into a pseudo reg, which we will copy
5042 into the true return register after the cleanups are done. */
5043 tree return_type = TREE_TYPE (res);
5045 /* If we may coalesce this result, make sure it has the expected mode
5046 in case it was promoted. But we need not bother about BLKmode. */
5047 machine_mode promoted_mode
5048 = flag_tree_coalesce_vars && is_gimple_reg (res)
5049 ? promote_ssa_mode (ssa_default_def (cfun, res), NULL)
5050 : BLKmode;
5052 if (promoted_mode != BLKmode)
5053 set_parm_rtl (res, gen_reg_rtx (promoted_mode));
5054 else if (TYPE_MODE (return_type) != BLKmode
5055 && targetm.calls.return_in_msb (return_type))
5056 /* expand_function_end will insert the appropriate padding in
5057 this case. Use the return value's natural (unpadded) mode
5058 within the function proper. */
5059 set_parm_rtl (res, gen_reg_rtx (TYPE_MODE (return_type)));
5060 else
5062 /* In order to figure out what mode to use for the pseudo, we
5063 figure out what the mode of the eventual return register will
5064 actually be, and use that. */
5065 rtx hard_reg = hard_function_value (return_type, subr, 0, 1);
5067 /* Structures that are returned in registers are not
5068 aggregate_value_p, so we may see a PARALLEL or a REG. */
5069 if (REG_P (hard_reg))
5070 set_parm_rtl (res, gen_reg_rtx (GET_MODE (hard_reg)));
5071 else
5073 gcc_assert (GET_CODE (hard_reg) == PARALLEL);
5074 set_parm_rtl (res, gen_group_rtx (hard_reg));
5078 /* Set DECL_REGISTER flag so that expand_function_end will copy the
5079 result to the real return register(s). */
5080 DECL_REGISTER (res) = 1;
5083 /* Initialize rtx for parameters and local variables.
5084 In some cases this requires emitting insns. */
5085 assign_parms (subr);
5087 /* If function gets a static chain arg, store it. */
5088 if (cfun->static_chain_decl)
5090 tree parm = cfun->static_chain_decl;
5091 rtx local, chain;
5092 rtx_insn *insn;
5093 int unsignedp;
5095 local = gen_reg_rtx (promote_decl_mode (parm, &unsignedp));
5096 chain = targetm.calls.static_chain (current_function_decl, true);
5098 set_decl_incoming_rtl (parm, chain, false);
5099 set_parm_rtl (parm, local);
5100 mark_reg_pointer (local, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
5102 if (GET_MODE (local) != GET_MODE (chain))
5104 convert_move (local, chain, unsignedp);
5105 insn = get_last_insn ();
5107 else
5108 insn = emit_move_insn (local, chain);
5110 /* Mark the register as eliminable, similar to parameters. */
5111 if (MEM_P (chain)
5112 && reg_mentioned_p (arg_pointer_rtx, XEXP (chain, 0)))
5113 set_dst_reg_note (insn, REG_EQUIV, chain, local);
5115 /* If we aren't optimizing, save the static chain onto the stack. */
5116 if (!optimize)
5118 tree saved_static_chain_decl
5119 = build_decl (DECL_SOURCE_LOCATION (parm), VAR_DECL,
5120 DECL_NAME (parm), TREE_TYPE (parm));
5121 rtx saved_static_chain_rtx
5122 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
5123 SET_DECL_RTL (saved_static_chain_decl, saved_static_chain_rtx);
5124 emit_move_insn (saved_static_chain_rtx, chain);
5125 SET_DECL_VALUE_EXPR (parm, saved_static_chain_decl);
5126 DECL_HAS_VALUE_EXPR_P (parm) = 1;
5130 /* The following was moved from init_function_start.
5131 The move was supposed to make sdb output more accurate. */
5132 /* Indicate the beginning of the function body,
5133 as opposed to parm setup. */
5134 emit_note (NOTE_INSN_FUNCTION_BEG);
5136 gcc_assert (NOTE_P (get_last_insn ()));
5138 parm_birth_insn = get_last_insn ();
5140 /* If the function receives a non-local goto, then store the
5141 bits we need to restore the frame pointer. */
5142 if (cfun->nonlocal_goto_save_area)
5144 tree t_save;
5145 rtx r_save;
5147 tree var = TREE_OPERAND (cfun->nonlocal_goto_save_area, 0);
5148 gcc_assert (DECL_RTL_SET_P (var));
5150 t_save = build4 (ARRAY_REF,
5151 TREE_TYPE (TREE_TYPE (cfun->nonlocal_goto_save_area)),
5152 cfun->nonlocal_goto_save_area,
5153 integer_zero_node, NULL_TREE, NULL_TREE);
5154 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
5155 gcc_assert (GET_MODE (r_save) == Pmode);
5157 emit_move_insn (r_save, targetm.builtin_setjmp_frame_value ());
5158 update_nonlocal_goto_save_area ();
5161 if (crtl->profile)
5163 #ifdef PROFILE_HOOK
5164 PROFILE_HOOK (current_function_funcdef_no);
5165 #endif
5168 /* If we are doing generic stack checking, the probe should go here. */
5169 if (flag_stack_check == GENERIC_STACK_CHECK)
5170 stack_check_probe_note = emit_note (NOTE_INSN_DELETED);
5173 void
5174 pop_dummy_function (void)
5176 pop_cfun ();
5177 in_dummy_function = false;
5180 /* Undo the effects of init_dummy_function_start. */
5181 void
5182 expand_dummy_function_end (void)
5184 gcc_assert (in_dummy_function);
5186 /* End any sequences that failed to be closed due to syntax errors. */
5187 while (in_sequence_p ())
5188 end_sequence ();
5190 /* Outside function body, can't compute type's actual size
5191 until next function's body starts. */
5193 free_after_parsing (cfun);
5194 free_after_compilation (cfun);
5195 pop_dummy_function ();
5198 /* Helper for diddle_return_value. */
5200 void
5201 diddle_return_value_1 (void (*doit) (rtx, void *), void *arg, rtx outgoing)
5203 if (! outgoing)
5204 return;
5206 if (REG_P (outgoing))
5207 (*doit) (outgoing, arg);
5208 else if (GET_CODE (outgoing) == PARALLEL)
5210 int i;
5212 for (i = 0; i < XVECLEN (outgoing, 0); i++)
5214 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
5216 if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
5217 (*doit) (x, arg);
5222 /* Call DOIT for each hard register used as a return value from
5223 the current function. */
5225 void
5226 diddle_return_value (void (*doit) (rtx, void *), void *arg)
5228 diddle_return_value_1 (doit, arg, crtl->return_rtx);
5231 static void
5232 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
5234 emit_clobber (reg);
5237 void
5238 clobber_return_register (void)
5240 diddle_return_value (do_clobber_return_reg, NULL);
5242 /* In case we do use pseudo to return value, clobber it too. */
5243 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
5245 tree decl_result = DECL_RESULT (current_function_decl);
5246 rtx decl_rtl = DECL_RTL (decl_result);
5247 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
5249 do_clobber_return_reg (decl_rtl, NULL);
5254 static void
5255 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
5257 emit_use (reg);
5260 static void
5261 use_return_register (void)
5263 diddle_return_value (do_use_return_reg, NULL);
5266 /* Set the location of the insn chain starting at INSN to LOC. */
5268 static void
5269 set_insn_locations (rtx_insn *insn, int loc)
5271 while (insn != NULL)
5273 if (INSN_P (insn))
5274 INSN_LOCATION (insn) = loc;
5275 insn = NEXT_INSN (insn);
5279 /* Generate RTL for the end of the current function. */
5281 void
5282 expand_function_end (void)
5284 /* If arg_pointer_save_area was referenced only from a nested
5285 function, we will not have initialized it yet. Do that now. */
5286 if (arg_pointer_save_area && ! crtl->arg_pointer_save_area_init)
5287 get_arg_pointer_save_area ();
5289 /* If we are doing generic stack checking and this function makes calls,
5290 do a stack probe at the start of the function to ensure we have enough
5291 space for another stack frame. */
5292 if (flag_stack_check == GENERIC_STACK_CHECK)
5294 rtx_insn *insn, *seq;
5296 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
5297 if (CALL_P (insn))
5299 rtx max_frame_size = GEN_INT (STACK_CHECK_MAX_FRAME_SIZE);
5300 start_sequence ();
5301 if (STACK_CHECK_MOVING_SP)
5302 anti_adjust_stack_and_probe (max_frame_size, true);
5303 else
5304 probe_stack_range (STACK_OLD_CHECK_PROTECT, max_frame_size);
5305 seq = get_insns ();
5306 end_sequence ();
5307 set_insn_locations (seq, prologue_location);
5308 emit_insn_before (seq, stack_check_probe_note);
5309 break;
5313 /* End any sequences that failed to be closed due to syntax errors. */
5314 while (in_sequence_p ())
5315 end_sequence ();
5317 clear_pending_stack_adjust ();
5318 do_pending_stack_adjust ();
5320 /* Output a linenumber for the end of the function.
5321 SDB depended on this. */
5322 set_curr_insn_location (input_location);
5324 /* Before the return label (if any), clobber the return
5325 registers so that they are not propagated live to the rest of
5326 the function. This can only happen with functions that drop
5327 through; if there had been a return statement, there would
5328 have either been a return rtx, or a jump to the return label.
5330 We delay actual code generation after the current_function_value_rtx
5331 is computed. */
5332 rtx_insn *clobber_after = get_last_insn ();
5334 /* Output the label for the actual return from the function. */
5335 emit_label (return_label);
5337 if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ)
5339 /* Let except.c know where it should emit the call to unregister
5340 the function context for sjlj exceptions. */
5341 if (flag_exceptions)
5342 sjlj_emit_function_exit_after (get_last_insn ());
5345 /* If this is an implementation of throw, do what's necessary to
5346 communicate between __builtin_eh_return and the epilogue. */
5347 expand_eh_return ();
5349 /* If scalar return value was computed in a pseudo-reg, or was a named
5350 return value that got dumped to the stack, copy that to the hard
5351 return register. */
5352 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
5354 tree decl_result = DECL_RESULT (current_function_decl);
5355 rtx decl_rtl = DECL_RTL (decl_result);
5357 if (REG_P (decl_rtl)
5358 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
5359 : DECL_REGISTER (decl_result))
5361 rtx real_decl_rtl = crtl->return_rtx;
5362 complex_mode cmode;
5364 /* This should be set in assign_parms. */
5365 gcc_assert (REG_FUNCTION_VALUE_P (real_decl_rtl));
5367 /* If this is a BLKmode structure being returned in registers,
5368 then use the mode computed in expand_return. Note that if
5369 decl_rtl is memory, then its mode may have been changed,
5370 but that crtl->return_rtx has not. */
5371 if (GET_MODE (real_decl_rtl) == BLKmode)
5372 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
5374 /* If a non-BLKmode return value should be padded at the least
5375 significant end of the register, shift it left by the appropriate
5376 amount. BLKmode results are handled using the group load/store
5377 machinery. */
5378 if (TYPE_MODE (TREE_TYPE (decl_result)) != BLKmode
5379 && REG_P (real_decl_rtl)
5380 && targetm.calls.return_in_msb (TREE_TYPE (decl_result)))
5382 emit_move_insn (gen_rtx_REG (GET_MODE (decl_rtl),
5383 REGNO (real_decl_rtl)),
5384 decl_rtl);
5385 shift_return_value (GET_MODE (decl_rtl), true, real_decl_rtl);
5387 else if (GET_CODE (real_decl_rtl) == PARALLEL)
5389 /* If expand_function_start has created a PARALLEL for decl_rtl,
5390 move the result to the real return registers. Otherwise, do
5391 a group load from decl_rtl for a named return. */
5392 if (GET_CODE (decl_rtl) == PARALLEL)
5393 emit_group_move (real_decl_rtl, decl_rtl);
5394 else
5395 emit_group_load (real_decl_rtl, decl_rtl,
5396 TREE_TYPE (decl_result),
5397 int_size_in_bytes (TREE_TYPE (decl_result)));
5399 /* In the case of complex integer modes smaller than a word, we'll
5400 need to generate some non-trivial bitfield insertions. Do that
5401 on a pseudo and not the hard register. */
5402 else if (GET_CODE (decl_rtl) == CONCAT
5403 && is_complex_int_mode (GET_MODE (decl_rtl), &cmode)
5404 && GET_MODE_BITSIZE (cmode) <= BITS_PER_WORD)
5406 int old_generating_concat_p;
5407 rtx tmp;
5409 old_generating_concat_p = generating_concat_p;
5410 generating_concat_p = 0;
5411 tmp = gen_reg_rtx (GET_MODE (decl_rtl));
5412 generating_concat_p = old_generating_concat_p;
5414 emit_move_insn (tmp, decl_rtl);
5415 emit_move_insn (real_decl_rtl, tmp);
5417 /* If a named return value dumped decl_return to memory, then
5418 we may need to re-do the PROMOTE_MODE signed/unsigned
5419 extension. */
5420 else if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
5422 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
5423 promote_function_mode (TREE_TYPE (decl_result),
5424 GET_MODE (decl_rtl), &unsignedp,
5425 TREE_TYPE (current_function_decl), 1);
5427 convert_move (real_decl_rtl, decl_rtl, unsignedp);
5429 else
5430 emit_move_insn (real_decl_rtl, decl_rtl);
5434 /* If returning a structure, arrange to return the address of the value
5435 in a place where debuggers expect to find it.
5437 If returning a structure PCC style,
5438 the caller also depends on this value.
5439 And cfun->returns_pcc_struct is not necessarily set. */
5440 if ((cfun->returns_struct || cfun->returns_pcc_struct)
5441 && !targetm.calls.omit_struct_return_reg)
5443 rtx value_address = DECL_RTL (DECL_RESULT (current_function_decl));
5444 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
5445 rtx outgoing;
5447 if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
5448 type = TREE_TYPE (type);
5449 else
5450 value_address = XEXP (value_address, 0);
5452 outgoing = targetm.calls.function_value (build_pointer_type (type),
5453 current_function_decl, true);
5455 /* Mark this as a function return value so integrate will delete the
5456 assignment and USE below when inlining this function. */
5457 REG_FUNCTION_VALUE_P (outgoing) = 1;
5459 /* The address may be ptr_mode and OUTGOING may be Pmode. */
5460 scalar_int_mode mode = as_a <scalar_int_mode> (GET_MODE (outgoing));
5461 value_address = convert_memory_address (mode, value_address);
5463 emit_move_insn (outgoing, value_address);
5465 /* Show return register used to hold result (in this case the address
5466 of the result. */
5467 crtl->return_rtx = outgoing;
5470 /* Emit the actual code to clobber return register. Don't emit
5471 it if clobber_after is a barrier, then the previous basic block
5472 certainly doesn't fall thru into the exit block. */
5473 if (!BARRIER_P (clobber_after))
5475 start_sequence ();
5476 clobber_return_register ();
5477 rtx_insn *seq = get_insns ();
5478 end_sequence ();
5480 emit_insn_after (seq, clobber_after);
5483 /* Output the label for the naked return from the function. */
5484 if (naked_return_label)
5485 emit_label (naked_return_label);
5487 /* @@@ This is a kludge. We want to ensure that instructions that
5488 may trap are not moved into the epilogue by scheduling, because
5489 we don't always emit unwind information for the epilogue. */
5490 if (cfun->can_throw_non_call_exceptions
5491 && targetm_common.except_unwind_info (&global_options) != UI_SJLJ)
5492 emit_insn (gen_blockage ());
5494 /* If stack protection is enabled for this function, check the guard. */
5495 if (crtl->stack_protect_guard && targetm.stack_protect_runtime_enabled_p ())
5496 stack_protect_epilogue ();
5498 /* If we had calls to alloca, and this machine needs
5499 an accurate stack pointer to exit the function,
5500 insert some code to save and restore the stack pointer. */
5501 if (! EXIT_IGNORE_STACK
5502 && cfun->calls_alloca)
5504 rtx tem = 0;
5506 start_sequence ();
5507 emit_stack_save (SAVE_FUNCTION, &tem);
5508 rtx_insn *seq = get_insns ();
5509 end_sequence ();
5510 emit_insn_before (seq, parm_birth_insn);
5512 emit_stack_restore (SAVE_FUNCTION, tem);
5515 /* ??? This should no longer be necessary since stupid is no longer with
5516 us, but there are some parts of the compiler (eg reload_combine, and
5517 sh mach_dep_reorg) that still try and compute their own lifetime info
5518 instead of using the general framework. */
5519 use_return_register ();
5523 get_arg_pointer_save_area (void)
5525 rtx ret = arg_pointer_save_area;
5527 if (! ret)
5529 ret = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
5530 arg_pointer_save_area = ret;
5533 if (! crtl->arg_pointer_save_area_init)
5535 /* Save the arg pointer at the beginning of the function. The
5536 generated stack slot may not be a valid memory address, so we
5537 have to check it and fix it if necessary. */
5538 start_sequence ();
5539 emit_move_insn (validize_mem (copy_rtx (ret)),
5540 crtl->args.internal_arg_pointer);
5541 rtx_insn *seq = get_insns ();
5542 end_sequence ();
5544 push_topmost_sequence ();
5545 emit_insn_after (seq, entry_of_function ());
5546 pop_topmost_sequence ();
5548 crtl->arg_pointer_save_area_init = true;
5551 return ret;
5555 /* If debugging dumps are requested, dump information about how the
5556 target handled -fstack-check=clash for the prologue.
5558 PROBES describes what if any probes were emitted.
5560 RESIDUALS indicates if the prologue had any residual allocation
5561 (i.e. total allocation was not a multiple of PROBE_INTERVAL). */
5563 void
5564 dump_stack_clash_frame_info (enum stack_clash_probes probes, bool residuals)
5566 if (!dump_file)
5567 return;
5569 switch (probes)
5571 case NO_PROBE_NO_FRAME:
5572 fprintf (dump_file,
5573 "Stack clash no probe no stack adjustment in prologue.\n");
5574 break;
5575 case NO_PROBE_SMALL_FRAME:
5576 fprintf (dump_file,
5577 "Stack clash no probe small stack adjustment in prologue.\n");
5578 break;
5579 case PROBE_INLINE:
5580 fprintf (dump_file, "Stack clash inline probes in prologue.\n");
5581 break;
5582 case PROBE_LOOP:
5583 fprintf (dump_file, "Stack clash probe loop in prologue.\n");
5584 break;
5587 if (residuals)
5588 fprintf (dump_file, "Stack clash residual allocation in prologue.\n");
5589 else
5590 fprintf (dump_file, "Stack clash no residual allocation in prologue.\n");
5592 if (frame_pointer_needed)
5593 fprintf (dump_file, "Stack clash frame pointer needed.\n");
5594 else
5595 fprintf (dump_file, "Stack clash no frame pointer needed.\n");
5597 if (TREE_THIS_VOLATILE (cfun->decl))
5598 fprintf (dump_file,
5599 "Stack clash noreturn prologue, assuming no implicit"
5600 " probes in caller.\n");
5601 else
5602 fprintf (dump_file,
5603 "Stack clash not noreturn prologue.\n");
5606 /* Add a list of INSNS to the hash HASHP, possibly allocating HASHP
5607 for the first time. */
5609 static void
5610 record_insns (rtx_insn *insns, rtx end, hash_table<insn_cache_hasher> **hashp)
5612 rtx_insn *tmp;
5613 hash_table<insn_cache_hasher> *hash = *hashp;
5615 if (hash == NULL)
5616 *hashp = hash = hash_table<insn_cache_hasher>::create_ggc (17);
5618 for (tmp = insns; tmp != end; tmp = NEXT_INSN (tmp))
5620 rtx *slot = hash->find_slot (tmp, INSERT);
5621 gcc_assert (*slot == NULL);
5622 *slot = tmp;
5626 /* INSN has been duplicated or replaced by as COPY, perhaps by duplicating a
5627 basic block, splitting or peepholes. If INSN is a prologue or epilogue
5628 insn, then record COPY as well. */
5630 void
5631 maybe_copy_prologue_epilogue_insn (rtx insn, rtx copy)
5633 hash_table<insn_cache_hasher> *hash;
5634 rtx *slot;
5636 hash = epilogue_insn_hash;
5637 if (!hash || !hash->find (insn))
5639 hash = prologue_insn_hash;
5640 if (!hash || !hash->find (insn))
5641 return;
5644 slot = hash->find_slot (copy, INSERT);
5645 gcc_assert (*slot == NULL);
5646 *slot = copy;
5649 /* Determine if any INSNs in HASH are, or are part of, INSN. Because
5650 we can be running after reorg, SEQUENCE rtl is possible. */
5652 static bool
5653 contains (const rtx_insn *insn, hash_table<insn_cache_hasher> *hash)
5655 if (hash == NULL)
5656 return false;
5658 if (NONJUMP_INSN_P (insn) && GET_CODE (PATTERN (insn)) == SEQUENCE)
5660 rtx_sequence *seq = as_a <rtx_sequence *> (PATTERN (insn));
5661 int i;
5662 for (i = seq->len () - 1; i >= 0; i--)
5663 if (hash->find (seq->element (i)))
5664 return true;
5665 return false;
5668 return hash->find (const_cast<rtx_insn *> (insn)) != NULL;
5672 prologue_contains (const rtx_insn *insn)
5674 return contains (insn, prologue_insn_hash);
5678 epilogue_contains (const rtx_insn *insn)
5680 return contains (insn, epilogue_insn_hash);
5684 prologue_epilogue_contains (const rtx_insn *insn)
5686 if (contains (insn, prologue_insn_hash))
5687 return 1;
5688 if (contains (insn, epilogue_insn_hash))
5689 return 1;
5690 return 0;
5693 void
5694 record_prologue_seq (rtx_insn *seq)
5696 record_insns (seq, NULL, &prologue_insn_hash);
5699 void
5700 record_epilogue_seq (rtx_insn *seq)
5702 record_insns (seq, NULL, &epilogue_insn_hash);
5705 /* Set JUMP_LABEL for a return insn. */
5707 void
5708 set_return_jump_label (rtx_insn *returnjump)
5710 rtx pat = PATTERN (returnjump);
5711 if (GET_CODE (pat) == PARALLEL)
5712 pat = XVECEXP (pat, 0, 0);
5713 if (ANY_RETURN_P (pat))
5714 JUMP_LABEL (returnjump) = pat;
5715 else
5716 JUMP_LABEL (returnjump) = ret_rtx;
5719 /* Return a sequence to be used as the split prologue for the current
5720 function, or NULL. */
5722 static rtx_insn *
5723 make_split_prologue_seq (void)
5725 if (!flag_split_stack
5726 || lookup_attribute ("no_split_stack", DECL_ATTRIBUTES (cfun->decl)))
5727 return NULL;
5729 start_sequence ();
5730 emit_insn (targetm.gen_split_stack_prologue ());
5731 rtx_insn *seq = get_insns ();
5732 end_sequence ();
5734 record_insns (seq, NULL, &prologue_insn_hash);
5735 set_insn_locations (seq, prologue_location);
5737 return seq;
5740 /* Return a sequence to be used as the prologue for the current function,
5741 or NULL. */
5743 static rtx_insn *
5744 make_prologue_seq (void)
5746 if (!targetm.have_prologue ())
5747 return NULL;
5749 start_sequence ();
5750 rtx_insn *seq = targetm.gen_prologue ();
5751 emit_insn (seq);
5753 /* Insert an explicit USE for the frame pointer
5754 if the profiling is on and the frame pointer is required. */
5755 if (crtl->profile && frame_pointer_needed)
5756 emit_use (hard_frame_pointer_rtx);
5758 /* Retain a map of the prologue insns. */
5759 record_insns (seq, NULL, &prologue_insn_hash);
5760 emit_note (NOTE_INSN_PROLOGUE_END);
5762 /* Ensure that instructions are not moved into the prologue when
5763 profiling is on. The call to the profiling routine can be
5764 emitted within the live range of a call-clobbered register. */
5765 if (!targetm.profile_before_prologue () && crtl->profile)
5766 emit_insn (gen_blockage ());
5768 seq = get_insns ();
5769 end_sequence ();
5770 set_insn_locations (seq, prologue_location);
5772 return seq;
5775 /* Return a sequence to be used as the epilogue for the current function,
5776 or NULL. */
5778 static rtx_insn *
5779 make_epilogue_seq (void)
5781 if (!targetm.have_epilogue ())
5782 return NULL;
5784 start_sequence ();
5785 emit_note (NOTE_INSN_EPILOGUE_BEG);
5786 rtx_insn *seq = targetm.gen_epilogue ();
5787 if (seq)
5788 emit_jump_insn (seq);
5790 /* Retain a map of the epilogue insns. */
5791 record_insns (seq, NULL, &epilogue_insn_hash);
5792 set_insn_locations (seq, epilogue_location);
5794 seq = get_insns ();
5795 rtx_insn *returnjump = get_last_insn ();
5796 end_sequence ();
5798 if (JUMP_P (returnjump))
5799 set_return_jump_label (returnjump);
5801 return seq;
5805 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
5806 this into place with notes indicating where the prologue ends and where
5807 the epilogue begins. Update the basic block information when possible.
5809 Notes on epilogue placement:
5810 There are several kinds of edges to the exit block:
5811 * a single fallthru edge from LAST_BB
5812 * possibly, edges from blocks containing sibcalls
5813 * possibly, fake edges from infinite loops
5815 The epilogue is always emitted on the fallthru edge from the last basic
5816 block in the function, LAST_BB, into the exit block.
5818 If LAST_BB is empty except for a label, it is the target of every
5819 other basic block in the function that ends in a return. If a
5820 target has a return or simple_return pattern (possibly with
5821 conditional variants), these basic blocks can be changed so that a
5822 return insn is emitted into them, and their target is adjusted to
5823 the real exit block.
5825 Notes on shrink wrapping: We implement a fairly conservative
5826 version of shrink-wrapping rather than the textbook one. We only
5827 generate a single prologue and a single epilogue. This is
5828 sufficient to catch a number of interesting cases involving early
5829 exits.
5831 First, we identify the blocks that require the prologue to occur before
5832 them. These are the ones that modify a call-saved register, or reference
5833 any of the stack or frame pointer registers. To simplify things, we then
5834 mark everything reachable from these blocks as also requiring a prologue.
5835 This takes care of loops automatically, and avoids the need to examine
5836 whether MEMs reference the frame, since it is sufficient to check for
5837 occurrences of the stack or frame pointer.
5839 We then compute the set of blocks for which the need for a prologue
5840 is anticipatable (borrowing terminology from the shrink-wrapping
5841 description in Muchnick's book). These are the blocks which either
5842 require a prologue themselves, or those that have only successors
5843 where the prologue is anticipatable. The prologue needs to be
5844 inserted on all edges from BB1->BB2 where BB2 is in ANTIC and BB1
5845 is not. For the moment, we ensure that only one such edge exists.
5847 The epilogue is placed as described above, but we make a
5848 distinction between inserting return and simple_return patterns
5849 when modifying other blocks that end in a return. Blocks that end
5850 in a sibcall omit the sibcall_epilogue if the block is not in
5851 ANTIC. */
5853 void
5854 thread_prologue_and_epilogue_insns (void)
5856 df_analyze ();
5858 /* Can't deal with multiple successors of the entry block at the
5859 moment. Function should always have at least one entry
5860 point. */
5861 gcc_assert (single_succ_p (ENTRY_BLOCK_PTR_FOR_FN (cfun)));
5863 edge entry_edge = single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun));
5864 edge orig_entry_edge = entry_edge;
5866 rtx_insn *split_prologue_seq = make_split_prologue_seq ();
5867 rtx_insn *prologue_seq = make_prologue_seq ();
5868 rtx_insn *epilogue_seq = make_epilogue_seq ();
5870 /* Try to perform a kind of shrink-wrapping, making sure the
5871 prologue/epilogue is emitted only around those parts of the
5872 function that require it. */
5873 try_shrink_wrapping (&entry_edge, prologue_seq);
5875 /* If the target can handle splitting the prologue/epilogue into separate
5876 components, try to shrink-wrap these components separately. */
5877 try_shrink_wrapping_separate (entry_edge->dest);
5879 /* If that did anything for any component we now need the generate the
5880 "main" prologue again. Because some targets require some of these
5881 to be called in a specific order (i386 requires the split prologue
5882 to be first, for example), we create all three sequences again here.
5883 If this does not work for some target, that target should not enable
5884 separate shrink-wrapping. */
5885 if (crtl->shrink_wrapped_separate)
5887 split_prologue_seq = make_split_prologue_seq ();
5888 prologue_seq = make_prologue_seq ();
5889 epilogue_seq = make_epilogue_seq ();
5892 rtl_profile_for_bb (EXIT_BLOCK_PTR_FOR_FN (cfun));
5894 /* A small fib -- epilogue is not yet completed, but we wish to re-use
5895 this marker for the splits of EH_RETURN patterns, and nothing else
5896 uses the flag in the meantime. */
5897 epilogue_completed = 1;
5899 /* Find non-fallthru edges that end with EH_RETURN instructions. On
5900 some targets, these get split to a special version of the epilogue
5901 code. In order to be able to properly annotate these with unwind
5902 info, try to split them now. If we get a valid split, drop an
5903 EPILOGUE_BEG note and mark the insns as epilogue insns. */
5904 edge e;
5905 edge_iterator ei;
5906 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
5908 rtx_insn *prev, *last, *trial;
5910 if (e->flags & EDGE_FALLTHRU)
5911 continue;
5912 last = BB_END (e->src);
5913 if (!eh_returnjump_p (last))
5914 continue;
5916 prev = PREV_INSN (last);
5917 trial = try_split (PATTERN (last), last, 1);
5918 if (trial == last)
5919 continue;
5921 record_insns (NEXT_INSN (prev), NEXT_INSN (trial), &epilogue_insn_hash);
5922 emit_note_after (NOTE_INSN_EPILOGUE_BEG, prev);
5925 edge exit_fallthru_edge = find_fallthru_edge (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds);
5927 if (exit_fallthru_edge)
5929 if (epilogue_seq)
5931 insert_insn_on_edge (epilogue_seq, exit_fallthru_edge);
5932 commit_edge_insertions ();
5934 /* The epilogue insns we inserted may cause the exit edge to no longer
5935 be fallthru. */
5936 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
5938 if (((e->flags & EDGE_FALLTHRU) != 0)
5939 && returnjump_p (BB_END (e->src)))
5940 e->flags &= ~EDGE_FALLTHRU;
5943 else if (next_active_insn (BB_END (exit_fallthru_edge->src)))
5945 /* We have a fall-through edge to the exit block, the source is not
5946 at the end of the function, and there will be an assembler epilogue
5947 at the end of the function.
5948 We can't use force_nonfallthru here, because that would try to
5949 use return. Inserting a jump 'by hand' is extremely messy, so
5950 we take advantage of cfg_layout_finalize using
5951 fixup_fallthru_exit_predecessor. */
5952 cfg_layout_initialize (0);
5953 basic_block cur_bb;
5954 FOR_EACH_BB_FN (cur_bb, cfun)
5955 if (cur_bb->index >= NUM_FIXED_BLOCKS
5956 && cur_bb->next_bb->index >= NUM_FIXED_BLOCKS)
5957 cur_bb->aux = cur_bb->next_bb;
5958 cfg_layout_finalize ();
5962 /* Insert the prologue. */
5964 rtl_profile_for_bb (ENTRY_BLOCK_PTR_FOR_FN (cfun));
5966 if (split_prologue_seq || prologue_seq)
5968 rtx_insn *split_prologue_insn = split_prologue_seq;
5969 if (split_prologue_seq)
5971 while (split_prologue_insn && !NONDEBUG_INSN_P (split_prologue_insn))
5972 split_prologue_insn = NEXT_INSN (split_prologue_insn);
5973 insert_insn_on_edge (split_prologue_seq, orig_entry_edge);
5976 rtx_insn *prologue_insn = prologue_seq;
5977 if (prologue_seq)
5979 while (prologue_insn && !NONDEBUG_INSN_P (prologue_insn))
5980 prologue_insn = NEXT_INSN (prologue_insn);
5981 insert_insn_on_edge (prologue_seq, entry_edge);
5984 commit_edge_insertions ();
5986 /* Look for basic blocks within the prologue insns. */
5987 if (split_prologue_insn
5988 && BLOCK_FOR_INSN (split_prologue_insn) == NULL)
5989 split_prologue_insn = NULL;
5990 if (prologue_insn
5991 && BLOCK_FOR_INSN (prologue_insn) == NULL)
5992 prologue_insn = NULL;
5993 if (split_prologue_insn || prologue_insn)
5995 auto_sbitmap blocks (last_basic_block_for_fn (cfun));
5996 bitmap_clear (blocks);
5997 if (split_prologue_insn)
5998 bitmap_set_bit (blocks,
5999 BLOCK_FOR_INSN (split_prologue_insn)->index);
6000 if (prologue_insn)
6001 bitmap_set_bit (blocks, BLOCK_FOR_INSN (prologue_insn)->index);
6002 find_many_sub_basic_blocks (blocks);
6006 default_rtl_profile ();
6008 /* Emit sibling epilogues before any sibling call sites. */
6009 for (ei = ei_start (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds);
6010 (e = ei_safe_edge (ei));
6011 ei_next (&ei))
6013 /* Skip those already handled, the ones that run without prologue. */
6014 if (e->flags & EDGE_IGNORE)
6016 e->flags &= ~EDGE_IGNORE;
6017 continue;
6020 rtx_insn *insn = BB_END (e->src);
6022 if (!(CALL_P (insn) && SIBLING_CALL_P (insn)))
6023 continue;
6025 if (rtx_insn *ep_seq = targetm.gen_sibcall_epilogue ())
6027 start_sequence ();
6028 emit_note (NOTE_INSN_EPILOGUE_BEG);
6029 emit_insn (ep_seq);
6030 rtx_insn *seq = get_insns ();
6031 end_sequence ();
6033 /* Retain a map of the epilogue insns. Used in life analysis to
6034 avoid getting rid of sibcall epilogue insns. Do this before we
6035 actually emit the sequence. */
6036 record_insns (seq, NULL, &epilogue_insn_hash);
6037 set_insn_locations (seq, epilogue_location);
6039 emit_insn_before (seq, insn);
6043 if (epilogue_seq)
6045 rtx_insn *insn, *next;
6047 /* Similarly, move any line notes that appear after the epilogue.
6048 There is no need, however, to be quite so anal about the existence
6049 of such a note. Also possibly move
6050 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
6051 info generation. */
6052 for (insn = epilogue_seq; insn; insn = next)
6054 next = NEXT_INSN (insn);
6055 if (NOTE_P (insn)
6056 && (NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG))
6057 reorder_insns (insn, insn, PREV_INSN (epilogue_seq));
6061 /* Threading the prologue and epilogue changes the artificial refs
6062 in the entry and exit blocks. */
6063 epilogue_completed = 1;
6064 df_update_entry_exit_and_calls ();
6067 /* Reposition the prologue-end and epilogue-begin notes after
6068 instruction scheduling. */
6070 void
6071 reposition_prologue_and_epilogue_notes (void)
6073 if (!targetm.have_prologue ()
6074 && !targetm.have_epilogue ()
6075 && !targetm.have_sibcall_epilogue ())
6076 return;
6078 /* Since the hash table is created on demand, the fact that it is
6079 non-null is a signal that it is non-empty. */
6080 if (prologue_insn_hash != NULL)
6082 size_t len = prologue_insn_hash->elements ();
6083 rtx_insn *insn, *last = NULL, *note = NULL;
6085 /* Scan from the beginning until we reach the last prologue insn. */
6086 /* ??? While we do have the CFG intact, there are two problems:
6087 (1) The prologue can contain loops (typically probing the stack),
6088 which means that the end of the prologue isn't in the first bb.
6089 (2) Sometimes the PROLOGUE_END note gets pushed into the next bb. */
6090 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
6092 if (NOTE_P (insn))
6094 if (NOTE_KIND (insn) == NOTE_INSN_PROLOGUE_END)
6095 note = insn;
6097 else if (contains (insn, prologue_insn_hash))
6099 last = insn;
6100 if (--len == 0)
6101 break;
6105 if (last)
6107 if (note == NULL)
6109 /* Scan forward looking for the PROLOGUE_END note. It should
6110 be right at the beginning of the block, possibly with other
6111 insn notes that got moved there. */
6112 for (note = NEXT_INSN (last); ; note = NEXT_INSN (note))
6114 if (NOTE_P (note)
6115 && NOTE_KIND (note) == NOTE_INSN_PROLOGUE_END)
6116 break;
6120 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
6121 if (LABEL_P (last))
6122 last = NEXT_INSN (last);
6123 reorder_insns (note, note, last);
6127 if (epilogue_insn_hash != NULL)
6129 edge_iterator ei;
6130 edge e;
6132 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
6134 rtx_insn *insn, *first = NULL, *note = NULL;
6135 basic_block bb = e->src;
6137 /* Scan from the beginning until we reach the first epilogue insn. */
6138 FOR_BB_INSNS (bb, insn)
6140 if (NOTE_P (insn))
6142 if (NOTE_KIND (insn) == NOTE_INSN_EPILOGUE_BEG)
6144 note = insn;
6145 if (first != NULL)
6146 break;
6149 else if (first == NULL && contains (insn, epilogue_insn_hash))
6151 first = insn;
6152 if (note != NULL)
6153 break;
6157 if (note)
6159 /* If the function has a single basic block, and no real
6160 epilogue insns (e.g. sibcall with no cleanup), the
6161 epilogue note can get scheduled before the prologue
6162 note. If we have frame related prologue insns, having
6163 them scanned during the epilogue will result in a crash.
6164 In this case re-order the epilogue note to just before
6165 the last insn in the block. */
6166 if (first == NULL)
6167 first = BB_END (bb);
6169 if (PREV_INSN (first) != note)
6170 reorder_insns (note, note, PREV_INSN (first));
6176 /* Returns the name of function declared by FNDECL. */
6177 const char *
6178 fndecl_name (tree fndecl)
6180 if (fndecl == NULL)
6181 return "(nofn)";
6182 return lang_hooks.decl_printable_name (fndecl, 1);
6185 /* Returns the name of function FN. */
6186 const char *
6187 function_name (struct function *fn)
6189 tree fndecl = (fn == NULL) ? NULL : fn->decl;
6190 return fndecl_name (fndecl);
6193 /* Returns the name of the current function. */
6194 const char *
6195 current_function_name (void)
6197 return function_name (cfun);
6201 static unsigned int
6202 rest_of_handle_check_leaf_regs (void)
6204 #ifdef LEAF_REGISTERS
6205 crtl->uses_only_leaf_regs
6206 = optimize > 0 && only_leaf_regs_used () && leaf_function_p ();
6207 #endif
6208 return 0;
6211 /* Insert a TYPE into the used types hash table of CFUN. */
6213 static void
6214 used_types_insert_helper (tree type, struct function *func)
6216 if (type != NULL && func != NULL)
6218 if (func->used_types_hash == NULL)
6219 func->used_types_hash = hash_set<tree>::create_ggc (37);
6221 func->used_types_hash->add (type);
6225 /* Given a type, insert it into the used hash table in cfun. */
6226 void
6227 used_types_insert (tree t)
6229 while (POINTER_TYPE_P (t) || TREE_CODE (t) == ARRAY_TYPE)
6230 if (TYPE_NAME (t))
6231 break;
6232 else
6233 t = TREE_TYPE (t);
6234 if (TREE_CODE (t) == ERROR_MARK)
6235 return;
6236 if (TYPE_NAME (t) == NULL_TREE
6237 || TYPE_NAME (t) == TYPE_NAME (TYPE_MAIN_VARIANT (t)))
6238 t = TYPE_MAIN_VARIANT (t);
6239 if (debug_info_level > DINFO_LEVEL_NONE)
6241 if (cfun)
6242 used_types_insert_helper (t, cfun);
6243 else
6245 /* So this might be a type referenced by a global variable.
6246 Record that type so that we can later decide to emit its
6247 debug information. */
6248 vec_safe_push (types_used_by_cur_var_decl, t);
6253 /* Helper to Hash a struct types_used_by_vars_entry. */
6255 static hashval_t
6256 hash_types_used_by_vars_entry (const struct types_used_by_vars_entry *entry)
6258 gcc_assert (entry && entry->var_decl && entry->type);
6260 return iterative_hash_object (entry->type,
6261 iterative_hash_object (entry->var_decl, 0));
6264 /* Hash function of the types_used_by_vars_entry hash table. */
6266 hashval_t
6267 used_type_hasher::hash (types_used_by_vars_entry *entry)
6269 return hash_types_used_by_vars_entry (entry);
6272 /*Equality function of the types_used_by_vars_entry hash table. */
6274 bool
6275 used_type_hasher::equal (types_used_by_vars_entry *e1,
6276 types_used_by_vars_entry *e2)
6278 return (e1->var_decl == e2->var_decl && e1->type == e2->type);
6281 /* Inserts an entry into the types_used_by_vars_hash hash table. */
6283 void
6284 types_used_by_var_decl_insert (tree type, tree var_decl)
6286 if (type != NULL && var_decl != NULL)
6288 types_used_by_vars_entry **slot;
6289 struct types_used_by_vars_entry e;
6290 e.var_decl = var_decl;
6291 e.type = type;
6292 if (types_used_by_vars_hash == NULL)
6293 types_used_by_vars_hash
6294 = hash_table<used_type_hasher>::create_ggc (37);
6296 slot = types_used_by_vars_hash->find_slot (&e, INSERT);
6297 if (*slot == NULL)
6299 struct types_used_by_vars_entry *entry;
6300 entry = ggc_alloc<types_used_by_vars_entry> ();
6301 entry->type = type;
6302 entry->var_decl = var_decl;
6303 *slot = entry;
6308 namespace {
6310 const pass_data pass_data_leaf_regs =
6312 RTL_PASS, /* type */
6313 "*leaf_regs", /* name */
6314 OPTGROUP_NONE, /* optinfo_flags */
6315 TV_NONE, /* tv_id */
6316 0, /* properties_required */
6317 0, /* properties_provided */
6318 0, /* properties_destroyed */
6319 0, /* todo_flags_start */
6320 0, /* todo_flags_finish */
6323 class pass_leaf_regs : public rtl_opt_pass
6325 public:
6326 pass_leaf_regs (gcc::context *ctxt)
6327 : rtl_opt_pass (pass_data_leaf_regs, ctxt)
6330 /* opt_pass methods: */
6331 virtual unsigned int execute (function *)
6333 return rest_of_handle_check_leaf_regs ();
6336 }; // class pass_leaf_regs
6338 } // anon namespace
6340 rtl_opt_pass *
6341 make_pass_leaf_regs (gcc::context *ctxt)
6343 return new pass_leaf_regs (ctxt);
6346 static unsigned int
6347 rest_of_handle_thread_prologue_and_epilogue (void)
6349 /* prepare_shrink_wrap is sensitive to the block structure of the control
6350 flow graph, so clean it up first. */
6351 if (optimize)
6352 cleanup_cfg (0);
6354 /* On some machines, the prologue and epilogue code, or parts thereof,
6355 can be represented as RTL. Doing so lets us schedule insns between
6356 it and the rest of the code and also allows delayed branch
6357 scheduling to operate in the epilogue. */
6358 thread_prologue_and_epilogue_insns ();
6360 /* Some non-cold blocks may now be only reachable from cold blocks.
6361 Fix that up. */
6362 fixup_partitions ();
6364 /* Shrink-wrapping can result in unreachable edges in the epilogue,
6365 see PR57320. */
6366 cleanup_cfg (optimize ? CLEANUP_EXPENSIVE : 0);
6368 /* The stack usage info is finalized during prologue expansion. */
6369 if (flag_stack_usage_info)
6370 output_stack_usage ();
6372 return 0;
6375 namespace {
6377 const pass_data pass_data_thread_prologue_and_epilogue =
6379 RTL_PASS, /* type */
6380 "pro_and_epilogue", /* name */
6381 OPTGROUP_NONE, /* optinfo_flags */
6382 TV_THREAD_PROLOGUE_AND_EPILOGUE, /* tv_id */
6383 0, /* properties_required */
6384 0, /* properties_provided */
6385 0, /* properties_destroyed */
6386 0, /* todo_flags_start */
6387 ( TODO_df_verify | TODO_df_finish ), /* todo_flags_finish */
6390 class pass_thread_prologue_and_epilogue : public rtl_opt_pass
6392 public:
6393 pass_thread_prologue_and_epilogue (gcc::context *ctxt)
6394 : rtl_opt_pass (pass_data_thread_prologue_and_epilogue, ctxt)
6397 /* opt_pass methods: */
6398 virtual unsigned int execute (function *)
6400 return rest_of_handle_thread_prologue_and_epilogue ();
6403 }; // class pass_thread_prologue_and_epilogue
6405 } // anon namespace
6407 rtl_opt_pass *
6408 make_pass_thread_prologue_and_epilogue (gcc::context *ctxt)
6410 return new pass_thread_prologue_and_epilogue (ctxt);
6414 /* This mini-pass fixes fall-out from SSA in asm statements that have
6415 in-out constraints. Say you start with
6417 orig = inout;
6418 asm ("": "+mr" (inout));
6419 use (orig);
6421 which is transformed very early to use explicit output and match operands:
6423 orig = inout;
6424 asm ("": "=mr" (inout) : "0" (inout));
6425 use (orig);
6427 Or, after SSA and copyprop,
6429 asm ("": "=mr" (inout_2) : "0" (inout_1));
6430 use (inout_1);
6432 Clearly inout_2 and inout_1 can't be coalesced easily anymore, as
6433 they represent two separate values, so they will get different pseudo
6434 registers during expansion. Then, since the two operands need to match
6435 per the constraints, but use different pseudo registers, reload can
6436 only register a reload for these operands. But reloads can only be
6437 satisfied by hardregs, not by memory, so we need a register for this
6438 reload, just because we are presented with non-matching operands.
6439 So, even though we allow memory for this operand, no memory can be
6440 used for it, just because the two operands don't match. This can
6441 cause reload failures on register-starved targets.
6443 So it's a symptom of reload not being able to use memory for reloads
6444 or, alternatively it's also a symptom of both operands not coming into
6445 reload as matching (in which case the pseudo could go to memory just
6446 fine, as the alternative allows it, and no reload would be necessary).
6447 We fix the latter problem here, by transforming
6449 asm ("": "=mr" (inout_2) : "0" (inout_1));
6451 back to
6453 inout_2 = inout_1;
6454 asm ("": "=mr" (inout_2) : "0" (inout_2)); */
6456 static void
6457 match_asm_constraints_1 (rtx_insn *insn, rtx *p_sets, int noutputs)
6459 int i;
6460 bool changed = false;
6461 rtx op = SET_SRC (p_sets[0]);
6462 int ninputs = ASM_OPERANDS_INPUT_LENGTH (op);
6463 rtvec inputs = ASM_OPERANDS_INPUT_VEC (op);
6464 bool *output_matched = XALLOCAVEC (bool, noutputs);
6466 memset (output_matched, 0, noutputs * sizeof (bool));
6467 for (i = 0; i < ninputs; i++)
6469 rtx input, output;
6470 rtx_insn *insns;
6471 const char *constraint = ASM_OPERANDS_INPUT_CONSTRAINT (op, i);
6472 char *end;
6473 int match, j;
6475 if (*constraint == '%')
6476 constraint++;
6478 match = strtoul (constraint, &end, 10);
6479 if (end == constraint)
6480 continue;
6482 gcc_assert (match < noutputs);
6483 output = SET_DEST (p_sets[match]);
6484 input = RTVEC_ELT (inputs, i);
6485 /* Only do the transformation for pseudos. */
6486 if (! REG_P (output)
6487 || rtx_equal_p (output, input)
6488 || !(REG_P (input) || SUBREG_P (input)
6489 || MEM_P (input) || CONSTANT_P (input))
6490 || !general_operand (input, GET_MODE (output)))
6491 continue;
6493 /* We can't do anything if the output is also used as input,
6494 as we're going to overwrite it. */
6495 for (j = 0; j < ninputs; j++)
6496 if (reg_overlap_mentioned_p (output, RTVEC_ELT (inputs, j)))
6497 break;
6498 if (j != ninputs)
6499 continue;
6501 /* Avoid changing the same input several times. For
6502 asm ("" : "=mr" (out1), "=mr" (out2) : "0" (in), "1" (in));
6503 only change in once (to out1), rather than changing it
6504 first to out1 and afterwards to out2. */
6505 if (i > 0)
6507 for (j = 0; j < noutputs; j++)
6508 if (output_matched[j] && input == SET_DEST (p_sets[j]))
6509 break;
6510 if (j != noutputs)
6511 continue;
6513 output_matched[match] = true;
6515 start_sequence ();
6516 emit_move_insn (output, input);
6517 insns = get_insns ();
6518 end_sequence ();
6519 emit_insn_before (insns, insn);
6521 /* Now replace all mentions of the input with output. We can't
6522 just replace the occurrence in inputs[i], as the register might
6523 also be used in some other input (or even in an address of an
6524 output), which would mean possibly increasing the number of
6525 inputs by one (namely 'output' in addition), which might pose
6526 a too complicated problem for reload to solve. E.g. this situation:
6528 asm ("" : "=r" (output), "=m" (input) : "0" (input))
6530 Here 'input' is used in two occurrences as input (once for the
6531 input operand, once for the address in the second output operand).
6532 If we would replace only the occurrence of the input operand (to
6533 make the matching) we would be left with this:
6535 output = input
6536 asm ("" : "=r" (output), "=m" (input) : "0" (output))
6538 Now we suddenly have two different input values (containing the same
6539 value, but different pseudos) where we formerly had only one.
6540 With more complicated asms this might lead to reload failures
6541 which wouldn't have happen without this pass. So, iterate over
6542 all operands and replace all occurrences of the register used. */
6543 for (j = 0; j < noutputs; j++)
6544 if (!rtx_equal_p (SET_DEST (p_sets[j]), input)
6545 && reg_overlap_mentioned_p (input, SET_DEST (p_sets[j])))
6546 SET_DEST (p_sets[j]) = replace_rtx (SET_DEST (p_sets[j]),
6547 input, output);
6548 for (j = 0; j < ninputs; j++)
6549 if (reg_overlap_mentioned_p (input, RTVEC_ELT (inputs, j)))
6550 RTVEC_ELT (inputs, j) = replace_rtx (RTVEC_ELT (inputs, j),
6551 input, output);
6553 changed = true;
6556 if (changed)
6557 df_insn_rescan (insn);
6560 /* Add the decl D to the local_decls list of FUN. */
6562 void
6563 add_local_decl (struct function *fun, tree d)
6565 gcc_assert (VAR_P (d));
6566 vec_safe_push (fun->local_decls, d);
6569 namespace {
6571 const pass_data pass_data_match_asm_constraints =
6573 RTL_PASS, /* type */
6574 "asmcons", /* name */
6575 OPTGROUP_NONE, /* optinfo_flags */
6576 TV_NONE, /* tv_id */
6577 0, /* properties_required */
6578 0, /* properties_provided */
6579 0, /* properties_destroyed */
6580 0, /* todo_flags_start */
6581 0, /* todo_flags_finish */
6584 class pass_match_asm_constraints : public rtl_opt_pass
6586 public:
6587 pass_match_asm_constraints (gcc::context *ctxt)
6588 : rtl_opt_pass (pass_data_match_asm_constraints, ctxt)
6591 /* opt_pass methods: */
6592 virtual unsigned int execute (function *);
6594 }; // class pass_match_asm_constraints
6596 unsigned
6597 pass_match_asm_constraints::execute (function *fun)
6599 basic_block bb;
6600 rtx_insn *insn;
6601 rtx pat, *p_sets;
6602 int noutputs;
6604 if (!crtl->has_asm_statement)
6605 return 0;
6607 df_set_flags (DF_DEFER_INSN_RESCAN);
6608 FOR_EACH_BB_FN (bb, fun)
6610 FOR_BB_INSNS (bb, insn)
6612 if (!INSN_P (insn))
6613 continue;
6615 pat = PATTERN (insn);
6616 if (GET_CODE (pat) == PARALLEL)
6617 p_sets = &XVECEXP (pat, 0, 0), noutputs = XVECLEN (pat, 0);
6618 else if (GET_CODE (pat) == SET)
6619 p_sets = &PATTERN (insn), noutputs = 1;
6620 else
6621 continue;
6623 if (GET_CODE (*p_sets) == SET
6624 && GET_CODE (SET_SRC (*p_sets)) == ASM_OPERANDS)
6625 match_asm_constraints_1 (insn, p_sets, noutputs);
6629 return TODO_df_finish;
6632 } // anon namespace
6634 rtl_opt_pass *
6635 make_pass_match_asm_constraints (gcc::context *ctxt)
6637 return new pass_match_asm_constraints (ctxt);
6641 #include "gt-function.h"