2016-04-27 Hristian Kirtchev <kirtchev@adacore.com>
[official-gcc.git] / gcc / function.c
blob43a80b428751f4ad73f9015f0cc38ec28520fbef
1 /* Expands front end tree to back end RTL for GCC.
2 Copyright (C) 1987-2016 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 "tm_p.h"
45 #include "stringpool.h"
46 #include "expmed.h"
47 #include "optabs.h"
48 #include "regs.h"
49 #include "emit-rtl.h"
50 #include "recog.h"
51 #include "rtl-error.h"
52 #include "alias.h"
53 #include "fold-const.h"
54 #include "stor-layout.h"
55 #include "varasm.h"
56 #include "except.h"
57 #include "dojump.h"
58 #include "explow.h"
59 #include "calls.h"
60 #include "expr.h"
61 #include "optabs-tree.h"
62 #include "output.h"
63 #include "langhooks.h"
64 #include "common/common-target.h"
65 #include "gimplify.h"
66 #include "tree-pass.h"
67 #include "cfgrtl.h"
68 #include "cfganal.h"
69 #include "cfgbuild.h"
70 #include "cfgcleanup.h"
71 #include "cfgexpand.h"
72 #include "shrink-wrap.h"
73 #include "toplev.h"
74 #include "rtl-iter.h"
75 #include "tree-chkp.h"
76 #include "rtl-chkp.h"
77 #include "tree-dfa.h"
78 #include "tree-ssa.h"
80 /* So we can assign to cfun in this file. */
81 #undef cfun
83 #ifndef STACK_ALIGNMENT_NEEDED
84 #define STACK_ALIGNMENT_NEEDED 1
85 #endif
87 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
89 /* Round a value to the lowest integer less than it that is a multiple of
90 the required alignment. Avoid using division in case the value is
91 negative. Assume the alignment is a power of two. */
92 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
94 /* Similar, but round to the next highest integer that meets the
95 alignment. */
96 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
98 /* Nonzero once virtual register instantiation has been done.
99 assign_stack_local uses frame_pointer_rtx when this is nonzero.
100 calls.c:emit_library_call_value_1 uses it to set up
101 post-instantiation libcalls. */
102 int virtuals_instantiated;
104 /* Assign unique numbers to labels generated for profiling, debugging, etc. */
105 static GTY(()) int funcdef_no;
107 /* These variables hold pointers to functions to create and destroy
108 target specific, per-function data structures. */
109 struct machine_function * (*init_machine_status) (void);
111 /* The currently compiled function. */
112 struct function *cfun = 0;
114 /* These hashes record the prologue and epilogue insns. */
116 struct insn_cache_hasher : ggc_cache_ptr_hash<rtx_def>
118 static hashval_t hash (rtx x) { return htab_hash_pointer (x); }
119 static bool equal (rtx a, rtx b) { return a == b; }
122 static GTY((cache))
123 hash_table<insn_cache_hasher> *prologue_insn_hash;
124 static GTY((cache))
125 hash_table<insn_cache_hasher> *epilogue_insn_hash;
128 hash_table<used_type_hasher> *types_used_by_vars_hash = NULL;
129 vec<tree, va_gc> *types_used_by_cur_var_decl;
131 /* Forward declarations. */
133 static struct temp_slot *find_temp_slot_from_address (rtx);
134 static void pad_to_arg_alignment (struct args_size *, int, struct args_size *);
135 static void pad_below (struct args_size *, machine_mode, tree);
136 static void reorder_blocks_1 (rtx_insn *, tree, vec<tree> *);
137 static int all_blocks (tree, tree *);
138 static tree *get_block_vector (tree, int *);
139 extern tree debug_find_var_in_block_tree (tree, tree);
140 /* We always define `record_insns' even if it's not used so that we
141 can always export `prologue_epilogue_contains'. */
142 static void record_insns (rtx_insn *, rtx, hash_table<insn_cache_hasher> **)
143 ATTRIBUTE_UNUSED;
144 static bool contains (const_rtx, hash_table<insn_cache_hasher> *);
145 static void prepare_function_start (void);
146 static void do_clobber_return_reg (rtx, void *);
147 static void do_use_return_reg (rtx, void *);
150 /* Stack of nested functions. */
151 /* Keep track of the cfun stack. */
153 static vec<function *> function_context_stack;
155 /* Save the current context for compilation of a nested function.
156 This is called from language-specific code. */
158 void
159 push_function_context (void)
161 if (cfun == 0)
162 allocate_struct_function (NULL, false);
164 function_context_stack.safe_push (cfun);
165 set_cfun (NULL);
168 /* Restore the last saved context, at the end of a nested function.
169 This function is called from language-specific code. */
171 void
172 pop_function_context (void)
174 struct function *p = function_context_stack.pop ();
175 set_cfun (p);
176 current_function_decl = p->decl;
178 /* Reset variables that have known state during rtx generation. */
179 virtuals_instantiated = 0;
180 generating_concat_p = 1;
183 /* Clear out all parts of the state in F that can safely be discarded
184 after the function has been parsed, but not compiled, to let
185 garbage collection reclaim the memory. */
187 void
188 free_after_parsing (struct function *f)
190 f->language = 0;
193 /* Clear out all parts of the state in F that can safely be discarded
194 after the function has been compiled, to let garbage collection
195 reclaim the memory. */
197 void
198 free_after_compilation (struct function *f)
200 prologue_insn_hash = NULL;
201 epilogue_insn_hash = NULL;
203 free (crtl->emit.regno_pointer_align);
205 memset (crtl, 0, sizeof (struct rtl_data));
206 f->eh = NULL;
207 f->machine = NULL;
208 f->cfg = NULL;
209 f->curr_properties &= ~PROP_cfg;
211 regno_reg_rtx = NULL;
214 /* Return size needed for stack frame based on slots so far allocated.
215 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
216 the caller may have to do that. */
218 HOST_WIDE_INT
219 get_frame_size (void)
221 if (FRAME_GROWS_DOWNWARD)
222 return -frame_offset;
223 else
224 return frame_offset;
227 /* Issue an error message and return TRUE if frame OFFSET overflows in
228 the signed target pointer arithmetics for function FUNC. Otherwise
229 return FALSE. */
231 bool
232 frame_offset_overflow (HOST_WIDE_INT offset, tree func)
234 unsigned HOST_WIDE_INT size = FRAME_GROWS_DOWNWARD ? -offset : offset;
236 if (size > ((unsigned HOST_WIDE_INT) 1 << (GET_MODE_BITSIZE (Pmode) - 1))
237 /* Leave room for the fixed part of the frame. */
238 - 64 * UNITS_PER_WORD)
240 error_at (DECL_SOURCE_LOCATION (func),
241 "total size of local objects too large");
242 return TRUE;
245 return FALSE;
248 /* Return stack slot alignment in bits for TYPE and MODE. */
250 static unsigned int
251 get_stack_local_alignment (tree type, machine_mode mode)
253 unsigned int alignment;
255 if (mode == BLKmode)
256 alignment = BIGGEST_ALIGNMENT;
257 else
258 alignment = GET_MODE_ALIGNMENT (mode);
260 /* Allow the frond-end to (possibly) increase the alignment of this
261 stack slot. */
262 if (! type)
263 type = lang_hooks.types.type_for_mode (mode, 0);
265 return STACK_SLOT_ALIGNMENT (type, mode, alignment);
268 /* Determine whether it is possible to fit a stack slot of size SIZE and
269 alignment ALIGNMENT into an area in the stack frame that starts at
270 frame offset START and has a length of LENGTH. If so, store the frame
271 offset to be used for the stack slot in *POFFSET and return true;
272 return false otherwise. This function will extend the frame size when
273 given a start/length pair that lies at the end of the frame. */
275 static bool
276 try_fit_stack_local (HOST_WIDE_INT start, HOST_WIDE_INT length,
277 HOST_WIDE_INT size, unsigned int alignment,
278 HOST_WIDE_INT *poffset)
280 HOST_WIDE_INT this_frame_offset;
281 int frame_off, frame_alignment, frame_phase;
283 /* Calculate how many bytes the start of local variables is off from
284 stack alignment. */
285 frame_alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
286 frame_off = STARTING_FRAME_OFFSET % frame_alignment;
287 frame_phase = frame_off ? frame_alignment - frame_off : 0;
289 /* Round the frame offset to the specified alignment. */
291 /* We must be careful here, since FRAME_OFFSET might be negative and
292 division with a negative dividend isn't as well defined as we might
293 like. So we instead assume that ALIGNMENT is a power of two and
294 use logical operations which are unambiguous. */
295 if (FRAME_GROWS_DOWNWARD)
296 this_frame_offset
297 = (FLOOR_ROUND (start + length - size - frame_phase,
298 (unsigned HOST_WIDE_INT) alignment)
299 + frame_phase);
300 else
301 this_frame_offset
302 = (CEIL_ROUND (start - frame_phase,
303 (unsigned HOST_WIDE_INT) alignment)
304 + frame_phase);
306 /* See if it fits. If this space is at the edge of the frame,
307 consider extending the frame to make it fit. Our caller relies on
308 this when allocating a new slot. */
309 if (frame_offset == start && this_frame_offset < frame_offset)
310 frame_offset = this_frame_offset;
311 else if (this_frame_offset < start)
312 return false;
313 else if (start + length == frame_offset
314 && this_frame_offset + size > start + length)
315 frame_offset = this_frame_offset + size;
316 else if (this_frame_offset + size > start + length)
317 return false;
319 *poffset = this_frame_offset;
320 return true;
323 /* Create a new frame_space structure describing free space in the stack
324 frame beginning at START and ending at END, and chain it into the
325 function's frame_space_list. */
327 static void
328 add_frame_space (HOST_WIDE_INT start, HOST_WIDE_INT end)
330 struct frame_space *space = ggc_alloc<frame_space> ();
331 space->next = crtl->frame_space_list;
332 crtl->frame_space_list = space;
333 space->start = start;
334 space->length = end - start;
337 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
338 with machine mode MODE.
340 ALIGN controls the amount of alignment for the address of the slot:
341 0 means according to MODE,
342 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
343 -2 means use BITS_PER_UNIT,
344 positive specifies alignment boundary in bits.
346 KIND has ASLK_REDUCE_ALIGN bit set if it is OK to reduce
347 alignment and ASLK_RECORD_PAD bit set if we should remember
348 extra space we allocated for alignment purposes. When we are
349 called from assign_stack_temp_for_type, it is not set so we don't
350 track the same stack slot in two independent lists.
352 We do not round to stack_boundary here. */
355 assign_stack_local_1 (machine_mode mode, HOST_WIDE_INT size,
356 int align, int kind)
358 rtx x, addr;
359 int bigend_correction = 0;
360 HOST_WIDE_INT slot_offset = 0, old_frame_offset;
361 unsigned int alignment, alignment_in_bits;
363 if (align == 0)
365 alignment = get_stack_local_alignment (NULL, mode);
366 alignment /= BITS_PER_UNIT;
368 else if (align == -1)
370 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
371 size = CEIL_ROUND (size, alignment);
373 else if (align == -2)
374 alignment = 1; /* BITS_PER_UNIT / BITS_PER_UNIT */
375 else
376 alignment = align / BITS_PER_UNIT;
378 alignment_in_bits = alignment * BITS_PER_UNIT;
380 /* Ignore alignment if it exceeds MAX_SUPPORTED_STACK_ALIGNMENT. */
381 if (alignment_in_bits > MAX_SUPPORTED_STACK_ALIGNMENT)
383 alignment_in_bits = MAX_SUPPORTED_STACK_ALIGNMENT;
384 alignment = alignment_in_bits / BITS_PER_UNIT;
387 if (SUPPORTS_STACK_ALIGNMENT)
389 if (crtl->stack_alignment_estimated < alignment_in_bits)
391 if (!crtl->stack_realign_processed)
392 crtl->stack_alignment_estimated = alignment_in_bits;
393 else
395 /* If stack is realigned and stack alignment value
396 hasn't been finalized, it is OK not to increase
397 stack_alignment_estimated. The bigger alignment
398 requirement is recorded in stack_alignment_needed
399 below. */
400 gcc_assert (!crtl->stack_realign_finalized);
401 if (!crtl->stack_realign_needed)
403 /* It is OK to reduce the alignment as long as the
404 requested size is 0 or the estimated stack
405 alignment >= mode alignment. */
406 gcc_assert ((kind & ASLK_REDUCE_ALIGN)
407 || size == 0
408 || (crtl->stack_alignment_estimated
409 >= GET_MODE_ALIGNMENT (mode)));
410 alignment_in_bits = crtl->stack_alignment_estimated;
411 alignment = alignment_in_bits / BITS_PER_UNIT;
417 if (crtl->stack_alignment_needed < alignment_in_bits)
418 crtl->stack_alignment_needed = alignment_in_bits;
419 if (crtl->max_used_stack_slot_alignment < alignment_in_bits)
420 crtl->max_used_stack_slot_alignment = alignment_in_bits;
422 if (mode != BLKmode || size != 0)
424 if (kind & ASLK_RECORD_PAD)
426 struct frame_space **psp;
428 for (psp = &crtl->frame_space_list; *psp; psp = &(*psp)->next)
430 struct frame_space *space = *psp;
431 if (!try_fit_stack_local (space->start, space->length, size,
432 alignment, &slot_offset))
433 continue;
434 *psp = space->next;
435 if (slot_offset > space->start)
436 add_frame_space (space->start, slot_offset);
437 if (slot_offset + size < space->start + space->length)
438 add_frame_space (slot_offset + size,
439 space->start + space->length);
440 goto found_space;
444 else if (!STACK_ALIGNMENT_NEEDED)
446 slot_offset = frame_offset;
447 goto found_space;
450 old_frame_offset = frame_offset;
452 if (FRAME_GROWS_DOWNWARD)
454 frame_offset -= size;
455 try_fit_stack_local (frame_offset, size, size, alignment, &slot_offset);
457 if (kind & ASLK_RECORD_PAD)
459 if (slot_offset > frame_offset)
460 add_frame_space (frame_offset, slot_offset);
461 if (slot_offset + size < old_frame_offset)
462 add_frame_space (slot_offset + size, old_frame_offset);
465 else
467 frame_offset += size;
468 try_fit_stack_local (old_frame_offset, size, size, alignment, &slot_offset);
470 if (kind & ASLK_RECORD_PAD)
472 if (slot_offset > old_frame_offset)
473 add_frame_space (old_frame_offset, slot_offset);
474 if (slot_offset + size < frame_offset)
475 add_frame_space (slot_offset + size, frame_offset);
479 found_space:
480 /* On a big-endian machine, if we are allocating more space than we will use,
481 use the least significant bytes of those that are allocated. */
482 if (BYTES_BIG_ENDIAN && mode != BLKmode && GET_MODE_SIZE (mode) < size)
483 bigend_correction = size - GET_MODE_SIZE (mode);
485 /* If we have already instantiated virtual registers, return the actual
486 address relative to the frame pointer. */
487 if (virtuals_instantiated)
488 addr = plus_constant (Pmode, frame_pointer_rtx,
489 trunc_int_for_mode
490 (slot_offset + bigend_correction
491 + STARTING_FRAME_OFFSET, Pmode));
492 else
493 addr = plus_constant (Pmode, virtual_stack_vars_rtx,
494 trunc_int_for_mode
495 (slot_offset + bigend_correction,
496 Pmode));
498 x = gen_rtx_MEM (mode, addr);
499 set_mem_align (x, alignment_in_bits);
500 MEM_NOTRAP_P (x) = 1;
502 stack_slot_list
503 = gen_rtx_EXPR_LIST (VOIDmode, x, stack_slot_list);
505 if (frame_offset_overflow (frame_offset, current_function_decl))
506 frame_offset = 0;
508 return x;
511 /* Wrap up assign_stack_local_1 with last parameter as false. */
514 assign_stack_local (machine_mode mode, HOST_WIDE_INT size, int align)
516 return assign_stack_local_1 (mode, size, align, ASLK_RECORD_PAD);
519 /* In order to evaluate some expressions, such as function calls returning
520 structures in memory, we need to temporarily allocate stack locations.
521 We record each allocated temporary in the following structure.
523 Associated with each temporary slot is a nesting level. When we pop up
524 one level, all temporaries associated with the previous level are freed.
525 Normally, all temporaries are freed after the execution of the statement
526 in which they were created. However, if we are inside a ({...}) grouping,
527 the result may be in a temporary and hence must be preserved. If the
528 result could be in a temporary, we preserve it if we can determine which
529 one it is in. If we cannot determine which temporary may contain the
530 result, all temporaries are preserved. A temporary is preserved by
531 pretending it was allocated at the previous nesting level. */
533 struct GTY(()) temp_slot {
534 /* Points to next temporary slot. */
535 struct temp_slot *next;
536 /* Points to previous temporary slot. */
537 struct temp_slot *prev;
538 /* The rtx to used to reference the slot. */
539 rtx slot;
540 /* The size, in units, of the slot. */
541 HOST_WIDE_INT size;
542 /* The type of the object in the slot, or zero if it doesn't correspond
543 to a type. We use this to determine whether a slot can be reused.
544 It can be reused if objects of the type of the new slot will always
545 conflict with objects of the type of the old slot. */
546 tree type;
547 /* The alignment (in bits) of the slot. */
548 unsigned int align;
549 /* Nonzero if this temporary is currently in use. */
550 char in_use;
551 /* Nesting level at which this slot is being used. */
552 int level;
553 /* The offset of the slot from the frame_pointer, including extra space
554 for alignment. This info is for combine_temp_slots. */
555 HOST_WIDE_INT base_offset;
556 /* The size of the slot, including extra space for alignment. This
557 info is for combine_temp_slots. */
558 HOST_WIDE_INT full_size;
561 /* Entry for the below hash table. */
562 struct GTY((for_user)) temp_slot_address_entry {
563 hashval_t hash;
564 rtx address;
565 struct temp_slot *temp_slot;
568 struct temp_address_hasher : ggc_ptr_hash<temp_slot_address_entry>
570 static hashval_t hash (temp_slot_address_entry *);
571 static bool equal (temp_slot_address_entry *, temp_slot_address_entry *);
574 /* A table of addresses that represent a stack slot. The table is a mapping
575 from address RTXen to a temp slot. */
576 static GTY(()) hash_table<temp_address_hasher> *temp_slot_address_table;
577 static size_t n_temp_slots_in_use;
579 /* Removes temporary slot TEMP from LIST. */
581 static void
582 cut_slot_from_list (struct temp_slot *temp, struct temp_slot **list)
584 if (temp->next)
585 temp->next->prev = temp->prev;
586 if (temp->prev)
587 temp->prev->next = temp->next;
588 else
589 *list = temp->next;
591 temp->prev = temp->next = NULL;
594 /* Inserts temporary slot TEMP to LIST. */
596 static void
597 insert_slot_to_list (struct temp_slot *temp, struct temp_slot **list)
599 temp->next = *list;
600 if (*list)
601 (*list)->prev = temp;
602 temp->prev = NULL;
603 *list = temp;
606 /* Returns the list of used temp slots at LEVEL. */
608 static struct temp_slot **
609 temp_slots_at_level (int level)
611 if (level >= (int) vec_safe_length (used_temp_slots))
612 vec_safe_grow_cleared (used_temp_slots, level + 1);
614 return &(*used_temp_slots)[level];
617 /* Returns the maximal temporary slot level. */
619 static int
620 max_slot_level (void)
622 if (!used_temp_slots)
623 return -1;
625 return used_temp_slots->length () - 1;
628 /* Moves temporary slot TEMP to LEVEL. */
630 static void
631 move_slot_to_level (struct temp_slot *temp, int level)
633 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
634 insert_slot_to_list (temp, temp_slots_at_level (level));
635 temp->level = level;
638 /* Make temporary slot TEMP available. */
640 static void
641 make_slot_available (struct temp_slot *temp)
643 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
644 insert_slot_to_list (temp, &avail_temp_slots);
645 temp->in_use = 0;
646 temp->level = -1;
647 n_temp_slots_in_use--;
650 /* Compute the hash value for an address -> temp slot mapping.
651 The value is cached on the mapping entry. */
652 static hashval_t
653 temp_slot_address_compute_hash (struct temp_slot_address_entry *t)
655 int do_not_record = 0;
656 return hash_rtx (t->address, GET_MODE (t->address),
657 &do_not_record, NULL, false);
660 /* Return the hash value for an address -> temp slot mapping. */
661 hashval_t
662 temp_address_hasher::hash (temp_slot_address_entry *t)
664 return t->hash;
667 /* Compare two address -> temp slot mapping entries. */
668 bool
669 temp_address_hasher::equal (temp_slot_address_entry *t1,
670 temp_slot_address_entry *t2)
672 return exp_equiv_p (t1->address, t2->address, 0, true);
675 /* Add ADDRESS as an alias of TEMP_SLOT to the addess -> temp slot mapping. */
676 static void
677 insert_temp_slot_address (rtx address, struct temp_slot *temp_slot)
679 struct temp_slot_address_entry *t = ggc_alloc<temp_slot_address_entry> ();
680 t->address = address;
681 t->temp_slot = temp_slot;
682 t->hash = temp_slot_address_compute_hash (t);
683 *temp_slot_address_table->find_slot_with_hash (t, t->hash, INSERT) = t;
686 /* Remove an address -> temp slot mapping entry if the temp slot is
687 not in use anymore. Callback for remove_unused_temp_slot_addresses. */
689 remove_unused_temp_slot_addresses_1 (temp_slot_address_entry **slot, void *)
691 const struct temp_slot_address_entry *t = *slot;
692 if (! t->temp_slot->in_use)
693 temp_slot_address_table->clear_slot (slot);
694 return 1;
697 /* Remove all mappings of addresses to unused temp slots. */
698 static void
699 remove_unused_temp_slot_addresses (void)
701 /* Use quicker clearing if there aren't any active temp slots. */
702 if (n_temp_slots_in_use)
703 temp_slot_address_table->traverse
704 <void *, remove_unused_temp_slot_addresses_1> (NULL);
705 else
706 temp_slot_address_table->empty ();
709 /* Find the temp slot corresponding to the object at address X. */
711 static struct temp_slot *
712 find_temp_slot_from_address (rtx x)
714 struct temp_slot *p;
715 struct temp_slot_address_entry tmp, *t;
717 /* First try the easy way:
718 See if X exists in the address -> temp slot mapping. */
719 tmp.address = x;
720 tmp.temp_slot = NULL;
721 tmp.hash = temp_slot_address_compute_hash (&tmp);
722 t = temp_slot_address_table->find_with_hash (&tmp, tmp.hash);
723 if (t)
724 return t->temp_slot;
726 /* If we have a sum involving a register, see if it points to a temp
727 slot. */
728 if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 0))
729 && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
730 return p;
731 else if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 1))
732 && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
733 return p;
735 /* Last resort: Address is a virtual stack var address. */
736 if (GET_CODE (x) == PLUS
737 && XEXP (x, 0) == virtual_stack_vars_rtx
738 && CONST_INT_P (XEXP (x, 1)))
740 int i;
741 for (i = max_slot_level (); i >= 0; i--)
742 for (p = *temp_slots_at_level (i); p; p = p->next)
744 if (INTVAL (XEXP (x, 1)) >= p->base_offset
745 && INTVAL (XEXP (x, 1)) < p->base_offset + p->full_size)
746 return p;
750 return NULL;
753 /* Allocate a temporary stack slot and record it for possible later
754 reuse.
756 MODE is the machine mode to be given to the returned rtx.
758 SIZE is the size in units of the space required. We do no rounding here
759 since assign_stack_local will do any required rounding.
761 TYPE is the type that will be used for the stack slot. */
764 assign_stack_temp_for_type (machine_mode mode, HOST_WIDE_INT size,
765 tree type)
767 unsigned int align;
768 struct temp_slot *p, *best_p = 0, *selected = NULL, **pp;
769 rtx slot;
771 /* If SIZE is -1 it means that somebody tried to allocate a temporary
772 of a variable size. */
773 gcc_assert (size != -1);
775 align = get_stack_local_alignment (type, mode);
777 /* Try to find an available, already-allocated temporary of the proper
778 mode which meets the size and alignment requirements. Choose the
779 smallest one with the closest alignment.
781 If assign_stack_temp is called outside of the tree->rtl expansion,
782 we cannot reuse the stack slots (that may still refer to
783 VIRTUAL_STACK_VARS_REGNUM). */
784 if (!virtuals_instantiated)
786 for (p = avail_temp_slots; p; p = p->next)
788 if (p->align >= align && p->size >= size
789 && GET_MODE (p->slot) == mode
790 && objects_must_conflict_p (p->type, type)
791 && (best_p == 0 || best_p->size > p->size
792 || (best_p->size == p->size && best_p->align > p->align)))
794 if (p->align == align && p->size == size)
796 selected = p;
797 cut_slot_from_list (selected, &avail_temp_slots);
798 best_p = 0;
799 break;
801 best_p = p;
806 /* Make our best, if any, the one to use. */
807 if (best_p)
809 selected = best_p;
810 cut_slot_from_list (selected, &avail_temp_slots);
812 /* If there are enough aligned bytes left over, make them into a new
813 temp_slot so that the extra bytes don't get wasted. Do this only
814 for BLKmode slots, so that we can be sure of the alignment. */
815 if (GET_MODE (best_p->slot) == BLKmode)
817 int alignment = best_p->align / BITS_PER_UNIT;
818 HOST_WIDE_INT rounded_size = CEIL_ROUND (size, alignment);
820 if (best_p->size - rounded_size >= alignment)
822 p = ggc_alloc<temp_slot> ();
823 p->in_use = 0;
824 p->size = best_p->size - rounded_size;
825 p->base_offset = best_p->base_offset + rounded_size;
826 p->full_size = best_p->full_size - rounded_size;
827 p->slot = adjust_address_nv (best_p->slot, BLKmode, rounded_size);
828 p->align = best_p->align;
829 p->type = best_p->type;
830 insert_slot_to_list (p, &avail_temp_slots);
832 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, p->slot,
833 stack_slot_list);
835 best_p->size = rounded_size;
836 best_p->full_size = rounded_size;
841 /* If we still didn't find one, make a new temporary. */
842 if (selected == 0)
844 HOST_WIDE_INT frame_offset_old = frame_offset;
846 p = ggc_alloc<temp_slot> ();
848 /* We are passing an explicit alignment request to assign_stack_local.
849 One side effect of that is assign_stack_local will not round SIZE
850 to ensure the frame offset remains suitably aligned.
852 So for requests which depended on the rounding of SIZE, we go ahead
853 and round it now. We also make sure ALIGNMENT is at least
854 BIGGEST_ALIGNMENT. */
855 gcc_assert (mode != BLKmode || align == BIGGEST_ALIGNMENT);
856 p->slot = assign_stack_local_1 (mode,
857 (mode == BLKmode
858 ? CEIL_ROUND (size,
859 (int) align
860 / BITS_PER_UNIT)
861 : size),
862 align, 0);
864 p->align = align;
866 /* The following slot size computation is necessary because we don't
867 know the actual size of the temporary slot until assign_stack_local
868 has performed all the frame alignment and size rounding for the
869 requested temporary. Note that extra space added for alignment
870 can be either above or below this stack slot depending on which
871 way the frame grows. We include the extra space if and only if it
872 is above this slot. */
873 if (FRAME_GROWS_DOWNWARD)
874 p->size = frame_offset_old - frame_offset;
875 else
876 p->size = size;
878 /* Now define the fields used by combine_temp_slots. */
879 if (FRAME_GROWS_DOWNWARD)
881 p->base_offset = frame_offset;
882 p->full_size = frame_offset_old - frame_offset;
884 else
886 p->base_offset = frame_offset_old;
887 p->full_size = frame_offset - frame_offset_old;
890 selected = p;
893 p = selected;
894 p->in_use = 1;
895 p->type = type;
896 p->level = temp_slot_level;
897 n_temp_slots_in_use++;
899 pp = temp_slots_at_level (p->level);
900 insert_slot_to_list (p, pp);
901 insert_temp_slot_address (XEXP (p->slot, 0), p);
903 /* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
904 slot = gen_rtx_MEM (mode, XEXP (p->slot, 0));
905 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, slot, stack_slot_list);
907 /* If we know the alias set for the memory that will be used, use
908 it. If there's no TYPE, then we don't know anything about the
909 alias set for the memory. */
910 set_mem_alias_set (slot, type ? get_alias_set (type) : 0);
911 set_mem_align (slot, align);
913 /* If a type is specified, set the relevant flags. */
914 if (type != 0)
915 MEM_VOLATILE_P (slot) = TYPE_VOLATILE (type);
916 MEM_NOTRAP_P (slot) = 1;
918 return slot;
921 /* Allocate a temporary stack slot and record it for possible later
922 reuse. First two arguments are same as in preceding function. */
925 assign_stack_temp (machine_mode mode, HOST_WIDE_INT size)
927 return assign_stack_temp_for_type (mode, size, NULL_TREE);
930 /* Assign a temporary.
931 If TYPE_OR_DECL is a decl, then we are doing it on behalf of the decl
932 and so that should be used in error messages. In either case, we
933 allocate of the given type.
934 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
935 it is 0 if a register is OK.
936 DONT_PROMOTE is 1 if we should not promote values in register
937 to wider modes. */
940 assign_temp (tree type_or_decl, int memory_required,
941 int dont_promote ATTRIBUTE_UNUSED)
943 tree type, decl;
944 machine_mode mode;
945 #ifdef PROMOTE_MODE
946 int unsignedp;
947 #endif
949 if (DECL_P (type_or_decl))
950 decl = type_or_decl, type = TREE_TYPE (decl);
951 else
952 decl = NULL, type = type_or_decl;
954 mode = TYPE_MODE (type);
955 #ifdef PROMOTE_MODE
956 unsignedp = TYPE_UNSIGNED (type);
957 #endif
959 /* Allocating temporaries of TREE_ADDRESSABLE type must be done in the front
960 end. See also create_tmp_var for the gimplification-time check. */
961 gcc_assert (!TREE_ADDRESSABLE (type) && COMPLETE_TYPE_P (type));
963 if (mode == BLKmode || memory_required)
965 HOST_WIDE_INT size = int_size_in_bytes (type);
966 rtx tmp;
968 /* Zero sized arrays are GNU C extension. Set size to 1 to avoid
969 problems with allocating the stack space. */
970 if (size == 0)
971 size = 1;
973 /* Unfortunately, we don't yet know how to allocate variable-sized
974 temporaries. However, sometimes we can find a fixed upper limit on
975 the size, so try that instead. */
976 else if (size == -1)
977 size = max_int_size_in_bytes (type);
979 /* The size of the temporary may be too large to fit into an integer. */
980 /* ??? Not sure this should happen except for user silliness, so limit
981 this to things that aren't compiler-generated temporaries. The
982 rest of the time we'll die in assign_stack_temp_for_type. */
983 if (decl && size == -1
984 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST)
986 error ("size of variable %q+D is too large", decl);
987 size = 1;
990 tmp = assign_stack_temp_for_type (mode, size, type);
991 return tmp;
994 #ifdef PROMOTE_MODE
995 if (! dont_promote)
996 mode = promote_mode (type, mode, &unsignedp);
997 #endif
999 return gen_reg_rtx (mode);
1002 /* Combine temporary stack slots which are adjacent on the stack.
1004 This allows for better use of already allocated stack space. This is only
1005 done for BLKmode slots because we can be sure that we won't have alignment
1006 problems in this case. */
1008 static void
1009 combine_temp_slots (void)
1011 struct temp_slot *p, *q, *next, *next_q;
1012 int num_slots;
1014 /* We can't combine slots, because the information about which slot
1015 is in which alias set will be lost. */
1016 if (flag_strict_aliasing)
1017 return;
1019 /* If there are a lot of temp slots, don't do anything unless
1020 high levels of optimization. */
1021 if (! flag_expensive_optimizations)
1022 for (p = avail_temp_slots, num_slots = 0; p; p = p->next, num_slots++)
1023 if (num_slots > 100 || (num_slots > 10 && optimize == 0))
1024 return;
1026 for (p = avail_temp_slots; p; p = next)
1028 int delete_p = 0;
1030 next = p->next;
1032 if (GET_MODE (p->slot) != BLKmode)
1033 continue;
1035 for (q = p->next; q; q = next_q)
1037 int delete_q = 0;
1039 next_q = q->next;
1041 if (GET_MODE (q->slot) != BLKmode)
1042 continue;
1044 if (p->base_offset + p->full_size == q->base_offset)
1046 /* Q comes after P; combine Q into P. */
1047 p->size += q->size;
1048 p->full_size += q->full_size;
1049 delete_q = 1;
1051 else if (q->base_offset + q->full_size == p->base_offset)
1053 /* P comes after Q; combine P into Q. */
1054 q->size += p->size;
1055 q->full_size += p->full_size;
1056 delete_p = 1;
1057 break;
1059 if (delete_q)
1060 cut_slot_from_list (q, &avail_temp_slots);
1063 /* Either delete P or advance past it. */
1064 if (delete_p)
1065 cut_slot_from_list (p, &avail_temp_slots);
1069 /* Indicate that NEW_RTX is an alternate way of referring to the temp
1070 slot that previously was known by OLD_RTX. */
1072 void
1073 update_temp_slot_address (rtx old_rtx, rtx new_rtx)
1075 struct temp_slot *p;
1077 if (rtx_equal_p (old_rtx, new_rtx))
1078 return;
1080 p = find_temp_slot_from_address (old_rtx);
1082 /* If we didn't find one, see if both OLD_RTX is a PLUS. If so, and
1083 NEW_RTX is a register, see if one operand of the PLUS is a
1084 temporary location. If so, NEW_RTX points into it. Otherwise,
1085 if both OLD_RTX and NEW_RTX are a PLUS and if there is a register
1086 in common between them. If so, try a recursive call on those
1087 values. */
1088 if (p == 0)
1090 if (GET_CODE (old_rtx) != PLUS)
1091 return;
1093 if (REG_P (new_rtx))
1095 update_temp_slot_address (XEXP (old_rtx, 0), new_rtx);
1096 update_temp_slot_address (XEXP (old_rtx, 1), new_rtx);
1097 return;
1099 else if (GET_CODE (new_rtx) != PLUS)
1100 return;
1102 if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 0)))
1103 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 1));
1104 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 0)))
1105 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 1));
1106 else if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 1)))
1107 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 0));
1108 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 1)))
1109 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 0));
1111 return;
1114 /* Otherwise add an alias for the temp's address. */
1115 insert_temp_slot_address (new_rtx, p);
1118 /* If X could be a reference to a temporary slot, mark that slot as
1119 belonging to the to one level higher than the current level. If X
1120 matched one of our slots, just mark that one. Otherwise, we can't
1121 easily predict which it is, so upgrade all of them.
1123 This is called when an ({...}) construct occurs and a statement
1124 returns a value in memory. */
1126 void
1127 preserve_temp_slots (rtx x)
1129 struct temp_slot *p = 0, *next;
1131 if (x == 0)
1132 return;
1134 /* If X is a register that is being used as a pointer, see if we have
1135 a temporary slot we know it points to. */
1136 if (REG_P (x) && REG_POINTER (x))
1137 p = find_temp_slot_from_address (x);
1139 /* If X is not in memory or is at a constant address, it cannot be in
1140 a temporary slot. */
1141 if (p == 0 && (!MEM_P (x) || CONSTANT_P (XEXP (x, 0))))
1142 return;
1144 /* First see if we can find a match. */
1145 if (p == 0)
1146 p = find_temp_slot_from_address (XEXP (x, 0));
1148 if (p != 0)
1150 if (p->level == temp_slot_level)
1151 move_slot_to_level (p, temp_slot_level - 1);
1152 return;
1155 /* Otherwise, preserve all non-kept slots at this level. */
1156 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1158 next = p->next;
1159 move_slot_to_level (p, temp_slot_level - 1);
1163 /* Free all temporaries used so far. This is normally called at the
1164 end of generating code for a statement. */
1166 void
1167 free_temp_slots (void)
1169 struct temp_slot *p, *next;
1170 bool some_available = false;
1172 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1174 next = p->next;
1175 make_slot_available (p);
1176 some_available = true;
1179 if (some_available)
1181 remove_unused_temp_slot_addresses ();
1182 combine_temp_slots ();
1186 /* Push deeper into the nesting level for stack temporaries. */
1188 void
1189 push_temp_slots (void)
1191 temp_slot_level++;
1194 /* Pop a temporary nesting level. All slots in use in the current level
1195 are freed. */
1197 void
1198 pop_temp_slots (void)
1200 free_temp_slots ();
1201 temp_slot_level--;
1204 /* Initialize temporary slots. */
1206 void
1207 init_temp_slots (void)
1209 /* We have not allocated any temporaries yet. */
1210 avail_temp_slots = 0;
1211 vec_alloc (used_temp_slots, 0);
1212 temp_slot_level = 0;
1213 n_temp_slots_in_use = 0;
1215 /* Set up the table to map addresses to temp slots. */
1216 if (! temp_slot_address_table)
1217 temp_slot_address_table = hash_table<temp_address_hasher>::create_ggc (32);
1218 else
1219 temp_slot_address_table->empty ();
1222 /* Functions and data structures to keep track of the values hard regs
1223 had at the start of the function. */
1225 /* Private type used by get_hard_reg_initial_reg, get_hard_reg_initial_val,
1226 and has_hard_reg_initial_val.. */
1227 struct GTY(()) initial_value_pair {
1228 rtx hard_reg;
1229 rtx pseudo;
1231 /* ??? This could be a VEC but there is currently no way to define an
1232 opaque VEC type. This could be worked around by defining struct
1233 initial_value_pair in function.h. */
1234 struct GTY(()) initial_value_struct {
1235 int num_entries;
1236 int max_entries;
1237 initial_value_pair * GTY ((length ("%h.num_entries"))) entries;
1240 /* If a pseudo represents an initial hard reg (or expression), return
1241 it, else return NULL_RTX. */
1244 get_hard_reg_initial_reg (rtx reg)
1246 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1247 int i;
1249 if (ivs == 0)
1250 return NULL_RTX;
1252 for (i = 0; i < ivs->num_entries; i++)
1253 if (rtx_equal_p (ivs->entries[i].pseudo, reg))
1254 return ivs->entries[i].hard_reg;
1256 return NULL_RTX;
1259 /* Make sure that there's a pseudo register of mode MODE that stores the
1260 initial value of hard register REGNO. Return an rtx for such a pseudo. */
1263 get_hard_reg_initial_val (machine_mode mode, unsigned int regno)
1265 struct initial_value_struct *ivs;
1266 rtx rv;
1268 rv = has_hard_reg_initial_val (mode, regno);
1269 if (rv)
1270 return rv;
1272 ivs = crtl->hard_reg_initial_vals;
1273 if (ivs == 0)
1275 ivs = ggc_alloc<initial_value_struct> ();
1276 ivs->num_entries = 0;
1277 ivs->max_entries = 5;
1278 ivs->entries = ggc_vec_alloc<initial_value_pair> (5);
1279 crtl->hard_reg_initial_vals = ivs;
1282 if (ivs->num_entries >= ivs->max_entries)
1284 ivs->max_entries += 5;
1285 ivs->entries = GGC_RESIZEVEC (initial_value_pair, ivs->entries,
1286 ivs->max_entries);
1289 ivs->entries[ivs->num_entries].hard_reg = gen_rtx_REG (mode, regno);
1290 ivs->entries[ivs->num_entries].pseudo = gen_reg_rtx (mode);
1292 return ivs->entries[ivs->num_entries++].pseudo;
1295 /* See if get_hard_reg_initial_val has been used to create a pseudo
1296 for the initial value of hard register REGNO in mode MODE. Return
1297 the associated pseudo if so, otherwise return NULL. */
1300 has_hard_reg_initial_val (machine_mode mode, unsigned int regno)
1302 struct initial_value_struct *ivs;
1303 int i;
1305 ivs = crtl->hard_reg_initial_vals;
1306 if (ivs != 0)
1307 for (i = 0; i < ivs->num_entries; i++)
1308 if (GET_MODE (ivs->entries[i].hard_reg) == mode
1309 && REGNO (ivs->entries[i].hard_reg) == regno)
1310 return ivs->entries[i].pseudo;
1312 return NULL_RTX;
1315 unsigned int
1316 emit_initial_value_sets (void)
1318 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1319 int i;
1320 rtx_insn *seq;
1322 if (ivs == 0)
1323 return 0;
1325 start_sequence ();
1326 for (i = 0; i < ivs->num_entries; i++)
1327 emit_move_insn (ivs->entries[i].pseudo, ivs->entries[i].hard_reg);
1328 seq = get_insns ();
1329 end_sequence ();
1331 emit_insn_at_entry (seq);
1332 return 0;
1335 /* Return the hardreg-pseudoreg initial values pair entry I and
1336 TRUE if I is a valid entry, or FALSE if I is not a valid entry. */
1337 bool
1338 initial_value_entry (int i, rtx *hreg, rtx *preg)
1340 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1341 if (!ivs || i >= ivs->num_entries)
1342 return false;
1344 *hreg = ivs->entries[i].hard_reg;
1345 *preg = ivs->entries[i].pseudo;
1346 return true;
1349 /* These routines are responsible for converting virtual register references
1350 to the actual hard register references once RTL generation is complete.
1352 The following four variables are used for communication between the
1353 routines. They contain the offsets of the virtual registers from their
1354 respective hard registers. */
1356 static int in_arg_offset;
1357 static int var_offset;
1358 static int dynamic_offset;
1359 static int out_arg_offset;
1360 static int cfa_offset;
1362 /* In most machines, the stack pointer register is equivalent to the bottom
1363 of the stack. */
1365 #ifndef STACK_POINTER_OFFSET
1366 #define STACK_POINTER_OFFSET 0
1367 #endif
1369 #if defined (REG_PARM_STACK_SPACE) && !defined (INCOMING_REG_PARM_STACK_SPACE)
1370 #define INCOMING_REG_PARM_STACK_SPACE REG_PARM_STACK_SPACE
1371 #endif
1373 /* If not defined, pick an appropriate default for the offset of dynamically
1374 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
1375 INCOMING_REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
1377 #ifndef STACK_DYNAMIC_OFFSET
1379 /* The bottom of the stack points to the actual arguments. If
1380 REG_PARM_STACK_SPACE is defined, this includes the space for the register
1381 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
1382 stack space for register parameters is not pushed by the caller, but
1383 rather part of the fixed stack areas and hence not included in
1384 `crtl->outgoing_args_size'. Nevertheless, we must allow
1385 for it when allocating stack dynamic objects. */
1387 #ifdef INCOMING_REG_PARM_STACK_SPACE
1388 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1389 ((ACCUMULATE_OUTGOING_ARGS \
1390 ? (crtl->outgoing_args_size \
1391 + (OUTGOING_REG_PARM_STACK_SPACE ((!(FNDECL) ? NULL_TREE : TREE_TYPE (FNDECL))) ? 0 \
1392 : INCOMING_REG_PARM_STACK_SPACE (FNDECL))) \
1393 : 0) + (STACK_POINTER_OFFSET))
1394 #else
1395 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1396 ((ACCUMULATE_OUTGOING_ARGS ? crtl->outgoing_args_size : 0) \
1397 + (STACK_POINTER_OFFSET))
1398 #endif
1399 #endif
1402 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
1403 is a virtual register, return the equivalent hard register and set the
1404 offset indirectly through the pointer. Otherwise, return 0. */
1406 static rtx
1407 instantiate_new_reg (rtx x, HOST_WIDE_INT *poffset)
1409 rtx new_rtx;
1410 HOST_WIDE_INT offset;
1412 if (x == virtual_incoming_args_rtx)
1414 if (stack_realign_drap)
1416 /* Replace virtual_incoming_args_rtx with internal arg
1417 pointer if DRAP is used to realign stack. */
1418 new_rtx = crtl->args.internal_arg_pointer;
1419 offset = 0;
1421 else
1422 new_rtx = arg_pointer_rtx, offset = in_arg_offset;
1424 else if (x == virtual_stack_vars_rtx)
1425 new_rtx = frame_pointer_rtx, offset = var_offset;
1426 else if (x == virtual_stack_dynamic_rtx)
1427 new_rtx = stack_pointer_rtx, offset = dynamic_offset;
1428 else if (x == virtual_outgoing_args_rtx)
1429 new_rtx = stack_pointer_rtx, offset = out_arg_offset;
1430 else if (x == virtual_cfa_rtx)
1432 #ifdef FRAME_POINTER_CFA_OFFSET
1433 new_rtx = frame_pointer_rtx;
1434 #else
1435 new_rtx = arg_pointer_rtx;
1436 #endif
1437 offset = cfa_offset;
1439 else if (x == virtual_preferred_stack_boundary_rtx)
1441 new_rtx = GEN_INT (crtl->preferred_stack_boundary / BITS_PER_UNIT);
1442 offset = 0;
1444 else
1445 return NULL_RTX;
1447 *poffset = offset;
1448 return new_rtx;
1451 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1452 registers present inside of *LOC. The expression is simplified,
1453 as much as possible, but is not to be considered "valid" in any sense
1454 implied by the target. Return true if any change is made. */
1456 static bool
1457 instantiate_virtual_regs_in_rtx (rtx *loc)
1459 if (!*loc)
1460 return false;
1461 bool changed = false;
1462 subrtx_ptr_iterator::array_type array;
1463 FOR_EACH_SUBRTX_PTR (iter, array, loc, NONCONST)
1465 rtx *loc = *iter;
1466 if (rtx x = *loc)
1468 rtx new_rtx;
1469 HOST_WIDE_INT offset;
1470 switch (GET_CODE (x))
1472 case REG:
1473 new_rtx = instantiate_new_reg (x, &offset);
1474 if (new_rtx)
1476 *loc = plus_constant (GET_MODE (x), new_rtx, offset);
1477 changed = true;
1479 iter.skip_subrtxes ();
1480 break;
1482 case PLUS:
1483 new_rtx = instantiate_new_reg (XEXP (x, 0), &offset);
1484 if (new_rtx)
1486 XEXP (x, 0) = new_rtx;
1487 *loc = plus_constant (GET_MODE (x), x, offset, true);
1488 changed = true;
1489 iter.skip_subrtxes ();
1490 break;
1493 /* FIXME -- from old code */
1494 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
1495 we can commute the PLUS and SUBREG because pointers into the
1496 frame are well-behaved. */
1497 break;
1499 default:
1500 break;
1504 return changed;
1507 /* A subroutine of instantiate_virtual_regs_in_insn. Return true if X
1508 matches the predicate for insn CODE operand OPERAND. */
1510 static int
1511 safe_insn_predicate (int code, int operand, rtx x)
1513 return code < 0 || insn_operand_matches ((enum insn_code) code, operand, x);
1516 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1517 registers present inside of insn. The result will be a valid insn. */
1519 static void
1520 instantiate_virtual_regs_in_insn (rtx_insn *insn)
1522 HOST_WIDE_INT offset;
1523 int insn_code, i;
1524 bool any_change = false;
1525 rtx set, new_rtx, x;
1526 rtx_insn *seq;
1528 /* There are some special cases to be handled first. */
1529 set = single_set (insn);
1530 if (set)
1532 /* We're allowed to assign to a virtual register. This is interpreted
1533 to mean that the underlying register gets assigned the inverse
1534 transformation. This is used, for example, in the handling of
1535 non-local gotos. */
1536 new_rtx = instantiate_new_reg (SET_DEST (set), &offset);
1537 if (new_rtx)
1539 start_sequence ();
1541 instantiate_virtual_regs_in_rtx (&SET_SRC (set));
1542 x = simplify_gen_binary (PLUS, GET_MODE (new_rtx), SET_SRC (set),
1543 gen_int_mode (-offset, GET_MODE (new_rtx)));
1544 x = force_operand (x, new_rtx);
1545 if (x != new_rtx)
1546 emit_move_insn (new_rtx, x);
1548 seq = get_insns ();
1549 end_sequence ();
1551 emit_insn_before (seq, insn);
1552 delete_insn (insn);
1553 return;
1556 /* Handle a straight copy from a virtual register by generating a
1557 new add insn. The difference between this and falling through
1558 to the generic case is avoiding a new pseudo and eliminating a
1559 move insn in the initial rtl stream. */
1560 new_rtx = instantiate_new_reg (SET_SRC (set), &offset);
1561 if (new_rtx && offset != 0
1562 && REG_P (SET_DEST (set))
1563 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1565 start_sequence ();
1567 x = expand_simple_binop (GET_MODE (SET_DEST (set)), PLUS, new_rtx,
1568 gen_int_mode (offset,
1569 GET_MODE (SET_DEST (set))),
1570 SET_DEST (set), 1, OPTAB_LIB_WIDEN);
1571 if (x != SET_DEST (set))
1572 emit_move_insn (SET_DEST (set), x);
1574 seq = get_insns ();
1575 end_sequence ();
1577 emit_insn_before (seq, insn);
1578 delete_insn (insn);
1579 return;
1582 extract_insn (insn);
1583 insn_code = INSN_CODE (insn);
1585 /* Handle a plus involving a virtual register by determining if the
1586 operands remain valid if they're modified in place. */
1587 if (GET_CODE (SET_SRC (set)) == PLUS
1588 && recog_data.n_operands >= 3
1589 && recog_data.operand_loc[1] == &XEXP (SET_SRC (set), 0)
1590 && recog_data.operand_loc[2] == &XEXP (SET_SRC (set), 1)
1591 && CONST_INT_P (recog_data.operand[2])
1592 && (new_rtx = instantiate_new_reg (recog_data.operand[1], &offset)))
1594 offset += INTVAL (recog_data.operand[2]);
1596 /* If the sum is zero, then replace with a plain move. */
1597 if (offset == 0
1598 && REG_P (SET_DEST (set))
1599 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1601 start_sequence ();
1602 emit_move_insn (SET_DEST (set), new_rtx);
1603 seq = get_insns ();
1604 end_sequence ();
1606 emit_insn_before (seq, insn);
1607 delete_insn (insn);
1608 return;
1611 x = gen_int_mode (offset, recog_data.operand_mode[2]);
1613 /* Using validate_change and apply_change_group here leaves
1614 recog_data in an invalid state. Since we know exactly what
1615 we want to check, do those two by hand. */
1616 if (safe_insn_predicate (insn_code, 1, new_rtx)
1617 && safe_insn_predicate (insn_code, 2, x))
1619 *recog_data.operand_loc[1] = recog_data.operand[1] = new_rtx;
1620 *recog_data.operand_loc[2] = recog_data.operand[2] = x;
1621 any_change = true;
1623 /* Fall through into the regular operand fixup loop in
1624 order to take care of operands other than 1 and 2. */
1628 else
1630 extract_insn (insn);
1631 insn_code = INSN_CODE (insn);
1634 /* In the general case, we expect virtual registers to appear only in
1635 operands, and then only as either bare registers or inside memories. */
1636 for (i = 0; i < recog_data.n_operands; ++i)
1638 x = recog_data.operand[i];
1639 switch (GET_CODE (x))
1641 case MEM:
1643 rtx addr = XEXP (x, 0);
1645 if (!instantiate_virtual_regs_in_rtx (&addr))
1646 continue;
1648 start_sequence ();
1649 x = replace_equiv_address (x, addr, true);
1650 /* It may happen that the address with the virtual reg
1651 was valid (e.g. based on the virtual stack reg, which might
1652 be acceptable to the predicates with all offsets), whereas
1653 the address now isn't anymore, for instance when the address
1654 is still offsetted, but the base reg isn't virtual-stack-reg
1655 anymore. Below we would do a force_reg on the whole operand,
1656 but this insn might actually only accept memory. Hence,
1657 before doing that last resort, try to reload the address into
1658 a register, so this operand stays a MEM. */
1659 if (!safe_insn_predicate (insn_code, i, x))
1661 addr = force_reg (GET_MODE (addr), addr);
1662 x = replace_equiv_address (x, addr, true);
1664 seq = get_insns ();
1665 end_sequence ();
1666 if (seq)
1667 emit_insn_before (seq, insn);
1669 break;
1671 case REG:
1672 new_rtx = instantiate_new_reg (x, &offset);
1673 if (new_rtx == NULL)
1674 continue;
1675 if (offset == 0)
1676 x = new_rtx;
1677 else
1679 start_sequence ();
1681 /* Careful, special mode predicates may have stuff in
1682 insn_data[insn_code].operand[i].mode that isn't useful
1683 to us for computing a new value. */
1684 /* ??? Recognize address_operand and/or "p" constraints
1685 to see if (plus new offset) is a valid before we put
1686 this through expand_simple_binop. */
1687 x = expand_simple_binop (GET_MODE (x), PLUS, new_rtx,
1688 gen_int_mode (offset, GET_MODE (x)),
1689 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1690 seq = get_insns ();
1691 end_sequence ();
1692 emit_insn_before (seq, insn);
1694 break;
1696 case SUBREG:
1697 new_rtx = instantiate_new_reg (SUBREG_REG (x), &offset);
1698 if (new_rtx == NULL)
1699 continue;
1700 if (offset != 0)
1702 start_sequence ();
1703 new_rtx = expand_simple_binop
1704 (GET_MODE (new_rtx), PLUS, new_rtx,
1705 gen_int_mode (offset, GET_MODE (new_rtx)),
1706 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1707 seq = get_insns ();
1708 end_sequence ();
1709 emit_insn_before (seq, insn);
1711 x = simplify_gen_subreg (recog_data.operand_mode[i], new_rtx,
1712 GET_MODE (new_rtx), SUBREG_BYTE (x));
1713 gcc_assert (x);
1714 break;
1716 default:
1717 continue;
1720 /* At this point, X contains the new value for the operand.
1721 Validate the new value vs the insn predicate. Note that
1722 asm insns will have insn_code -1 here. */
1723 if (!safe_insn_predicate (insn_code, i, x))
1725 start_sequence ();
1726 if (REG_P (x))
1728 gcc_assert (REGNO (x) <= LAST_VIRTUAL_REGISTER);
1729 x = copy_to_reg (x);
1731 else
1732 x = force_reg (insn_data[insn_code].operand[i].mode, x);
1733 seq = get_insns ();
1734 end_sequence ();
1735 if (seq)
1736 emit_insn_before (seq, insn);
1739 *recog_data.operand_loc[i] = recog_data.operand[i] = x;
1740 any_change = true;
1743 if (any_change)
1745 /* Propagate operand changes into the duplicates. */
1746 for (i = 0; i < recog_data.n_dups; ++i)
1747 *recog_data.dup_loc[i]
1748 = copy_rtx (recog_data.operand[(unsigned)recog_data.dup_num[i]]);
1750 /* Force re-recognition of the instruction for validation. */
1751 INSN_CODE (insn) = -1;
1754 if (asm_noperands (PATTERN (insn)) >= 0)
1756 if (!check_asm_operands (PATTERN (insn)))
1758 error_for_asm (insn, "impossible constraint in %<asm%>");
1759 /* For asm goto, instead of fixing up all the edges
1760 just clear the template and clear input operands
1761 (asm goto doesn't have any output operands). */
1762 if (JUMP_P (insn))
1764 rtx asm_op = extract_asm_operands (PATTERN (insn));
1765 ASM_OPERANDS_TEMPLATE (asm_op) = ggc_strdup ("");
1766 ASM_OPERANDS_INPUT_VEC (asm_op) = rtvec_alloc (0);
1767 ASM_OPERANDS_INPUT_CONSTRAINT_VEC (asm_op) = rtvec_alloc (0);
1769 else
1770 delete_insn (insn);
1773 else
1775 if (recog_memoized (insn) < 0)
1776 fatal_insn_not_found (insn);
1780 /* Subroutine of instantiate_decls. Given RTL representing a decl,
1781 do any instantiation required. */
1783 void
1784 instantiate_decl_rtl (rtx x)
1786 rtx addr;
1788 if (x == 0)
1789 return;
1791 /* If this is a CONCAT, recurse for the pieces. */
1792 if (GET_CODE (x) == CONCAT)
1794 instantiate_decl_rtl (XEXP (x, 0));
1795 instantiate_decl_rtl (XEXP (x, 1));
1796 return;
1799 /* If this is not a MEM, no need to do anything. Similarly if the
1800 address is a constant or a register that is not a virtual register. */
1801 if (!MEM_P (x))
1802 return;
1804 addr = XEXP (x, 0);
1805 if (CONSTANT_P (addr)
1806 || (REG_P (addr)
1807 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
1808 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
1809 return;
1811 instantiate_virtual_regs_in_rtx (&XEXP (x, 0));
1814 /* Helper for instantiate_decls called via walk_tree: Process all decls
1815 in the given DECL_VALUE_EXPR. */
1817 static tree
1818 instantiate_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1820 tree t = *tp;
1821 if (! EXPR_P (t))
1823 *walk_subtrees = 0;
1824 if (DECL_P (t))
1826 if (DECL_RTL_SET_P (t))
1827 instantiate_decl_rtl (DECL_RTL (t));
1828 if (TREE_CODE (t) == PARM_DECL && DECL_NAMELESS (t)
1829 && DECL_INCOMING_RTL (t))
1830 instantiate_decl_rtl (DECL_INCOMING_RTL (t));
1831 if ((TREE_CODE (t) == VAR_DECL
1832 || TREE_CODE (t) == RESULT_DECL)
1833 && DECL_HAS_VALUE_EXPR_P (t))
1835 tree v = DECL_VALUE_EXPR (t);
1836 walk_tree (&v, instantiate_expr, NULL, NULL);
1840 return NULL;
1843 /* Subroutine of instantiate_decls: Process all decls in the given
1844 BLOCK node and all its subblocks. */
1846 static void
1847 instantiate_decls_1 (tree let)
1849 tree t;
1851 for (t = BLOCK_VARS (let); t; t = DECL_CHAIN (t))
1853 if (DECL_RTL_SET_P (t))
1854 instantiate_decl_rtl (DECL_RTL (t));
1855 if (TREE_CODE (t) == VAR_DECL && DECL_HAS_VALUE_EXPR_P (t))
1857 tree v = DECL_VALUE_EXPR (t);
1858 walk_tree (&v, instantiate_expr, NULL, NULL);
1862 /* Process all subblocks. */
1863 for (t = BLOCK_SUBBLOCKS (let); t; t = BLOCK_CHAIN (t))
1864 instantiate_decls_1 (t);
1867 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1868 all virtual registers in their DECL_RTL's. */
1870 static void
1871 instantiate_decls (tree fndecl)
1873 tree decl;
1874 unsigned ix;
1876 /* Process all parameters of the function. */
1877 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = DECL_CHAIN (decl))
1879 instantiate_decl_rtl (DECL_RTL (decl));
1880 instantiate_decl_rtl (DECL_INCOMING_RTL (decl));
1881 if (DECL_HAS_VALUE_EXPR_P (decl))
1883 tree v = DECL_VALUE_EXPR (decl);
1884 walk_tree (&v, instantiate_expr, NULL, NULL);
1888 if ((decl = DECL_RESULT (fndecl))
1889 && TREE_CODE (decl) == RESULT_DECL)
1891 if (DECL_RTL_SET_P (decl))
1892 instantiate_decl_rtl (DECL_RTL (decl));
1893 if (DECL_HAS_VALUE_EXPR_P (decl))
1895 tree v = DECL_VALUE_EXPR (decl);
1896 walk_tree (&v, instantiate_expr, NULL, NULL);
1900 /* Process the saved static chain if it exists. */
1901 decl = DECL_STRUCT_FUNCTION (fndecl)->static_chain_decl;
1902 if (decl && DECL_HAS_VALUE_EXPR_P (decl))
1903 instantiate_decl_rtl (DECL_RTL (DECL_VALUE_EXPR (decl)));
1905 /* Now process all variables defined in the function or its subblocks. */
1906 instantiate_decls_1 (DECL_INITIAL (fndecl));
1908 FOR_EACH_LOCAL_DECL (cfun, ix, decl)
1909 if (DECL_RTL_SET_P (decl))
1910 instantiate_decl_rtl (DECL_RTL (decl));
1911 vec_free (cfun->local_decls);
1914 /* Pass through the INSNS of function FNDECL and convert virtual register
1915 references to hard register references. */
1917 static unsigned int
1918 instantiate_virtual_regs (void)
1920 rtx_insn *insn;
1922 /* Compute the offsets to use for this function. */
1923 in_arg_offset = FIRST_PARM_OFFSET (current_function_decl);
1924 var_offset = STARTING_FRAME_OFFSET;
1925 dynamic_offset = STACK_DYNAMIC_OFFSET (current_function_decl);
1926 out_arg_offset = STACK_POINTER_OFFSET;
1927 #ifdef FRAME_POINTER_CFA_OFFSET
1928 cfa_offset = FRAME_POINTER_CFA_OFFSET (current_function_decl);
1929 #else
1930 cfa_offset = ARG_POINTER_CFA_OFFSET (current_function_decl);
1931 #endif
1933 /* Initialize recognition, indicating that volatile is OK. */
1934 init_recog ();
1936 /* Scan through all the insns, instantiating every virtual register still
1937 present. */
1938 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
1939 if (INSN_P (insn))
1941 /* These patterns in the instruction stream can never be recognized.
1942 Fortunately, they shouldn't contain virtual registers either. */
1943 if (GET_CODE (PATTERN (insn)) == USE
1944 || GET_CODE (PATTERN (insn)) == CLOBBER
1945 || GET_CODE (PATTERN (insn)) == ASM_INPUT)
1946 continue;
1947 else if (DEBUG_INSN_P (insn))
1948 instantiate_virtual_regs_in_rtx (&INSN_VAR_LOCATION (insn));
1949 else
1950 instantiate_virtual_regs_in_insn (insn);
1952 if (insn->deleted ())
1953 continue;
1955 instantiate_virtual_regs_in_rtx (&REG_NOTES (insn));
1957 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
1958 if (CALL_P (insn))
1959 instantiate_virtual_regs_in_rtx (&CALL_INSN_FUNCTION_USAGE (insn));
1962 /* Instantiate the virtual registers in the DECLs for debugging purposes. */
1963 instantiate_decls (current_function_decl);
1965 targetm.instantiate_decls ();
1967 /* Indicate that, from now on, assign_stack_local should use
1968 frame_pointer_rtx. */
1969 virtuals_instantiated = 1;
1971 return 0;
1974 namespace {
1976 const pass_data pass_data_instantiate_virtual_regs =
1978 RTL_PASS, /* type */
1979 "vregs", /* name */
1980 OPTGROUP_NONE, /* optinfo_flags */
1981 TV_NONE, /* tv_id */
1982 0, /* properties_required */
1983 0, /* properties_provided */
1984 0, /* properties_destroyed */
1985 0, /* todo_flags_start */
1986 0, /* todo_flags_finish */
1989 class pass_instantiate_virtual_regs : public rtl_opt_pass
1991 public:
1992 pass_instantiate_virtual_regs (gcc::context *ctxt)
1993 : rtl_opt_pass (pass_data_instantiate_virtual_regs, ctxt)
1996 /* opt_pass methods: */
1997 virtual unsigned int execute (function *)
1999 return instantiate_virtual_regs ();
2002 }; // class pass_instantiate_virtual_regs
2004 } // anon namespace
2006 rtl_opt_pass *
2007 make_pass_instantiate_virtual_regs (gcc::context *ctxt)
2009 return new pass_instantiate_virtual_regs (ctxt);
2013 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
2014 This means a type for which function calls must pass an address to the
2015 function or get an address back from the function.
2016 EXP may be a type node or an expression (whose type is tested). */
2019 aggregate_value_p (const_tree exp, const_tree fntype)
2021 const_tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
2022 int i, regno, nregs;
2023 rtx reg;
2025 if (fntype)
2026 switch (TREE_CODE (fntype))
2028 case CALL_EXPR:
2030 tree fndecl = get_callee_fndecl (fntype);
2031 if (fndecl)
2032 fntype = TREE_TYPE (fndecl);
2033 else if (CALL_EXPR_FN (fntype))
2034 fntype = TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (fntype)));
2035 else
2036 /* For internal functions, assume nothing needs to be
2037 returned in memory. */
2038 return 0;
2040 break;
2041 case FUNCTION_DECL:
2042 fntype = TREE_TYPE (fntype);
2043 break;
2044 case FUNCTION_TYPE:
2045 case METHOD_TYPE:
2046 break;
2047 case IDENTIFIER_NODE:
2048 fntype = NULL_TREE;
2049 break;
2050 default:
2051 /* We don't expect other tree types here. */
2052 gcc_unreachable ();
2055 if (VOID_TYPE_P (type))
2056 return 0;
2058 /* If a record should be passed the same as its first (and only) member
2059 don't pass it as an aggregate. */
2060 if (TREE_CODE (type) == RECORD_TYPE && TYPE_TRANSPARENT_AGGR (type))
2061 return aggregate_value_p (first_field (type), fntype);
2063 /* If the front end has decided that this needs to be passed by
2064 reference, do so. */
2065 if ((TREE_CODE (exp) == PARM_DECL || TREE_CODE (exp) == RESULT_DECL)
2066 && DECL_BY_REFERENCE (exp))
2067 return 1;
2069 /* Function types that are TREE_ADDRESSABLE force return in memory. */
2070 if (fntype && TREE_ADDRESSABLE (fntype))
2071 return 1;
2073 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
2074 and thus can't be returned in registers. */
2075 if (TREE_ADDRESSABLE (type))
2076 return 1;
2078 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
2079 return 1;
2081 if (targetm.calls.return_in_memory (type, fntype))
2082 return 1;
2084 /* Make sure we have suitable call-clobbered regs to return
2085 the value in; if not, we must return it in memory. */
2086 reg = hard_function_value (type, 0, fntype, 0);
2088 /* If we have something other than a REG (e.g. a PARALLEL), then assume
2089 it is OK. */
2090 if (!REG_P (reg))
2091 return 0;
2093 regno = REGNO (reg);
2094 nregs = hard_regno_nregs[regno][TYPE_MODE (type)];
2095 for (i = 0; i < nregs; i++)
2096 if (! call_used_regs[regno + i])
2097 return 1;
2099 return 0;
2102 /* Return true if we should assign DECL a pseudo register; false if it
2103 should live on the local stack. */
2105 bool
2106 use_register_for_decl (const_tree decl)
2108 if (TREE_CODE (decl) == SSA_NAME)
2110 /* We often try to use the SSA_NAME, instead of its underlying
2111 decl, to get type information and guide decisions, to avoid
2112 differences of behavior between anonymous and named
2113 variables, but in this one case we have to go for the actual
2114 variable if there is one. The main reason is that, at least
2115 at -O0, we want to place user variables on the stack, but we
2116 don't mind using pseudos for anonymous or ignored temps.
2117 Should we take the SSA_NAME, we'd conclude all SSA_NAMEs
2118 should go in pseudos, whereas their corresponding variables
2119 might have to go on the stack. So, disregarding the decl
2120 here would negatively impact debug info at -O0, enable
2121 coalescing between SSA_NAMEs that ought to get different
2122 stack/pseudo assignments, and get the incoming argument
2123 processing thoroughly confused by PARM_DECLs expected to live
2124 in stack slots but assigned to pseudos. */
2125 if (!SSA_NAME_VAR (decl))
2126 return TYPE_MODE (TREE_TYPE (decl)) != BLKmode
2127 && !(flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)));
2129 decl = SSA_NAME_VAR (decl);
2132 /* Honor volatile. */
2133 if (TREE_SIDE_EFFECTS (decl))
2134 return false;
2136 /* Honor addressability. */
2137 if (TREE_ADDRESSABLE (decl))
2138 return false;
2140 /* RESULT_DECLs are a bit special in that they're assigned without
2141 regard to use_register_for_decl, but we generally only store in
2142 them. If we coalesce their SSA NAMEs, we'd better return a
2143 result that matches the assignment in expand_function_start. */
2144 if (TREE_CODE (decl) == RESULT_DECL)
2146 /* If it's not an aggregate, we're going to use a REG or a
2147 PARALLEL containing a REG. */
2148 if (!aggregate_value_p (decl, current_function_decl))
2149 return true;
2151 /* If expand_function_start determines the return value, we'll
2152 use MEM if it's not by reference. */
2153 if (cfun->returns_pcc_struct
2154 || (targetm.calls.struct_value_rtx
2155 (TREE_TYPE (current_function_decl), 1)))
2156 return DECL_BY_REFERENCE (decl);
2158 /* Otherwise, we're taking an extra all.function_result_decl
2159 argument. It's set up in assign_parms_augmented_arg_list,
2160 under the (negated) conditions above, and then it's used to
2161 set up the RESULT_DECL rtl in assign_params, after looping
2162 over all parameters. Now, if the RESULT_DECL is not by
2163 reference, we'll use a MEM either way. */
2164 if (!DECL_BY_REFERENCE (decl))
2165 return false;
2167 /* Otherwise, if RESULT_DECL is DECL_BY_REFERENCE, it will take
2168 the function_result_decl's assignment. Since it's a pointer,
2169 we can short-circuit a number of the tests below, and we must
2170 duplicat e them because we don't have the
2171 function_result_decl to test. */
2172 if (!targetm.calls.allocate_stack_slots_for_args ())
2173 return true;
2174 /* We don't set DECL_IGNORED_P for the function_result_decl. */
2175 if (optimize)
2176 return true;
2177 /* We don't set DECL_REGISTER for the function_result_decl. */
2178 return false;
2181 /* Decl is implicitly addressible by bound stores and loads
2182 if it is an aggregate holding bounds. */
2183 if (chkp_function_instrumented_p (current_function_decl)
2184 && TREE_TYPE (decl)
2185 && !BOUNDED_P (decl)
2186 && chkp_type_has_pointer (TREE_TYPE (decl)))
2187 return false;
2189 /* Only register-like things go in registers. */
2190 if (DECL_MODE (decl) == BLKmode)
2191 return false;
2193 /* If -ffloat-store specified, don't put explicit float variables
2194 into registers. */
2195 /* ??? This should be checked after DECL_ARTIFICIAL, but tree-ssa
2196 propagates values across these stores, and it probably shouldn't. */
2197 if (flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)))
2198 return false;
2200 if (!targetm.calls.allocate_stack_slots_for_args ())
2201 return true;
2203 /* If we're not interested in tracking debugging information for
2204 this decl, then we can certainly put it in a register. */
2205 if (DECL_IGNORED_P (decl))
2206 return true;
2208 if (optimize)
2209 return true;
2211 if (!DECL_REGISTER (decl))
2212 return false;
2214 switch (TREE_CODE (TREE_TYPE (decl)))
2216 case RECORD_TYPE:
2217 case UNION_TYPE:
2218 case QUAL_UNION_TYPE:
2219 /* When not optimizing, disregard register keyword for variables with
2220 types containing methods, otherwise the methods won't be callable
2221 from the debugger. */
2222 if (TYPE_METHODS (TYPE_MAIN_VARIANT (TREE_TYPE (decl))))
2223 return false;
2224 break;
2225 default:
2226 break;
2229 return true;
2232 /* Structures to communicate between the subroutines of assign_parms.
2233 The first holds data persistent across all parameters, the second
2234 is cleared out for each parameter. */
2236 struct assign_parm_data_all
2238 /* When INIT_CUMULATIVE_ARGS gets revamped, allocating CUMULATIVE_ARGS
2239 should become a job of the target or otherwise encapsulated. */
2240 CUMULATIVE_ARGS args_so_far_v;
2241 cumulative_args_t args_so_far;
2242 struct args_size stack_args_size;
2243 tree function_result_decl;
2244 tree orig_fnargs;
2245 rtx_insn *first_conversion_insn;
2246 rtx_insn *last_conversion_insn;
2247 HOST_WIDE_INT pretend_args_size;
2248 HOST_WIDE_INT extra_pretend_bytes;
2249 int reg_parm_stack_space;
2252 struct assign_parm_data_one
2254 tree nominal_type;
2255 tree passed_type;
2256 rtx entry_parm;
2257 rtx stack_parm;
2258 machine_mode nominal_mode;
2259 machine_mode passed_mode;
2260 machine_mode promoted_mode;
2261 struct locate_and_pad_arg_data locate;
2262 int partial;
2263 BOOL_BITFIELD named_arg : 1;
2264 BOOL_BITFIELD passed_pointer : 1;
2265 BOOL_BITFIELD on_stack : 1;
2266 BOOL_BITFIELD loaded_in_reg : 1;
2269 struct bounds_parm_data
2271 assign_parm_data_one parm_data;
2272 tree bounds_parm;
2273 tree ptr_parm;
2274 rtx ptr_entry;
2275 int bound_no;
2278 /* A subroutine of assign_parms. Initialize ALL. */
2280 static void
2281 assign_parms_initialize_all (struct assign_parm_data_all *all)
2283 tree fntype ATTRIBUTE_UNUSED;
2285 memset (all, 0, sizeof (*all));
2287 fntype = TREE_TYPE (current_function_decl);
2289 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
2290 INIT_CUMULATIVE_INCOMING_ARGS (all->args_so_far_v, fntype, NULL_RTX);
2291 #else
2292 INIT_CUMULATIVE_ARGS (all->args_so_far_v, fntype, NULL_RTX,
2293 current_function_decl, -1);
2294 #endif
2295 all->args_so_far = pack_cumulative_args (&all->args_so_far_v);
2297 #ifdef INCOMING_REG_PARM_STACK_SPACE
2298 all->reg_parm_stack_space
2299 = INCOMING_REG_PARM_STACK_SPACE (current_function_decl);
2300 #endif
2303 /* If ARGS contains entries with complex types, split the entry into two
2304 entries of the component type. Return a new list of substitutions are
2305 needed, else the old list. */
2307 static void
2308 split_complex_args (vec<tree> *args)
2310 unsigned i;
2311 tree p;
2313 FOR_EACH_VEC_ELT (*args, i, p)
2315 tree type = TREE_TYPE (p);
2316 if (TREE_CODE (type) == COMPLEX_TYPE
2317 && targetm.calls.split_complex_arg (type))
2319 tree decl;
2320 tree subtype = TREE_TYPE (type);
2321 bool addressable = TREE_ADDRESSABLE (p);
2323 /* Rewrite the PARM_DECL's type with its component. */
2324 p = copy_node (p);
2325 TREE_TYPE (p) = subtype;
2326 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
2327 DECL_MODE (p) = VOIDmode;
2328 DECL_SIZE (p) = NULL;
2329 DECL_SIZE_UNIT (p) = NULL;
2330 /* If this arg must go in memory, put it in a pseudo here.
2331 We can't allow it to go in memory as per normal parms,
2332 because the usual place might not have the imag part
2333 adjacent to the real part. */
2334 DECL_ARTIFICIAL (p) = addressable;
2335 DECL_IGNORED_P (p) = addressable;
2336 TREE_ADDRESSABLE (p) = 0;
2337 layout_decl (p, 0);
2338 (*args)[i] = p;
2340 /* Build a second synthetic decl. */
2341 decl = build_decl (EXPR_LOCATION (p),
2342 PARM_DECL, NULL_TREE, subtype);
2343 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
2344 DECL_ARTIFICIAL (decl) = addressable;
2345 DECL_IGNORED_P (decl) = addressable;
2346 layout_decl (decl, 0);
2347 args->safe_insert (++i, decl);
2352 /* A subroutine of assign_parms. Adjust the parameter list to incorporate
2353 the hidden struct return argument, and (abi willing) complex args.
2354 Return the new parameter list. */
2356 static vec<tree>
2357 assign_parms_augmented_arg_list (struct assign_parm_data_all *all)
2359 tree fndecl = current_function_decl;
2360 tree fntype = TREE_TYPE (fndecl);
2361 vec<tree> fnargs = vNULL;
2362 tree arg;
2364 for (arg = DECL_ARGUMENTS (fndecl); arg; arg = DECL_CHAIN (arg))
2365 fnargs.safe_push (arg);
2367 all->orig_fnargs = DECL_ARGUMENTS (fndecl);
2369 /* If struct value address is treated as the first argument, make it so. */
2370 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
2371 && ! cfun->returns_pcc_struct
2372 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
2374 tree type = build_pointer_type (TREE_TYPE (fntype));
2375 tree decl;
2377 decl = build_decl (DECL_SOURCE_LOCATION (fndecl),
2378 PARM_DECL, get_identifier (".result_ptr"), type);
2379 DECL_ARG_TYPE (decl) = type;
2380 DECL_ARTIFICIAL (decl) = 1;
2381 DECL_NAMELESS (decl) = 1;
2382 TREE_CONSTANT (decl) = 1;
2383 /* We don't set DECL_IGNORED_P or DECL_REGISTER here. If this
2384 changes, the end of the RESULT_DECL handling block in
2385 use_register_for_decl must be adjusted to match. */
2387 DECL_CHAIN (decl) = all->orig_fnargs;
2388 all->orig_fnargs = decl;
2389 fnargs.safe_insert (0, decl);
2391 all->function_result_decl = decl;
2393 /* If function is instrumented then bounds of the
2394 passed structure address is the second argument. */
2395 if (chkp_function_instrumented_p (fndecl))
2397 decl = build_decl (DECL_SOURCE_LOCATION (fndecl),
2398 PARM_DECL, get_identifier (".result_bnd"),
2399 pointer_bounds_type_node);
2400 DECL_ARG_TYPE (decl) = pointer_bounds_type_node;
2401 DECL_ARTIFICIAL (decl) = 1;
2402 DECL_NAMELESS (decl) = 1;
2403 TREE_CONSTANT (decl) = 1;
2405 DECL_CHAIN (decl) = DECL_CHAIN (all->orig_fnargs);
2406 DECL_CHAIN (all->orig_fnargs) = decl;
2407 fnargs.safe_insert (1, decl);
2411 /* If the target wants to split complex arguments into scalars, do so. */
2412 if (targetm.calls.split_complex_arg)
2413 split_complex_args (&fnargs);
2415 return fnargs;
2418 /* A subroutine of assign_parms. Examine PARM and pull out type and mode
2419 data for the parameter. Incorporate ABI specifics such as pass-by-
2420 reference and type promotion. */
2422 static void
2423 assign_parm_find_data_types (struct assign_parm_data_all *all, tree parm,
2424 struct assign_parm_data_one *data)
2426 tree nominal_type, passed_type;
2427 machine_mode nominal_mode, passed_mode, promoted_mode;
2428 int unsignedp;
2430 memset (data, 0, sizeof (*data));
2432 /* NAMED_ARG is a misnomer. We really mean 'non-variadic'. */
2433 if (!cfun->stdarg)
2434 data->named_arg = 1; /* No variadic parms. */
2435 else if (DECL_CHAIN (parm))
2436 data->named_arg = 1; /* Not the last non-variadic parm. */
2437 else if (targetm.calls.strict_argument_naming (all->args_so_far))
2438 data->named_arg = 1; /* Only variadic ones are unnamed. */
2439 else
2440 data->named_arg = 0; /* Treat as variadic. */
2442 nominal_type = TREE_TYPE (parm);
2443 passed_type = DECL_ARG_TYPE (parm);
2445 /* Look out for errors propagating this far. Also, if the parameter's
2446 type is void then its value doesn't matter. */
2447 if (TREE_TYPE (parm) == error_mark_node
2448 /* This can happen after weird syntax errors
2449 or if an enum type is defined among the parms. */
2450 || TREE_CODE (parm) != PARM_DECL
2451 || passed_type == NULL
2452 || VOID_TYPE_P (nominal_type))
2454 nominal_type = passed_type = void_type_node;
2455 nominal_mode = passed_mode = promoted_mode = VOIDmode;
2456 goto egress;
2459 /* Find mode of arg as it is passed, and mode of arg as it should be
2460 during execution of this function. */
2461 passed_mode = TYPE_MODE (passed_type);
2462 nominal_mode = TYPE_MODE (nominal_type);
2464 /* If the parm is to be passed as a transparent union or record, use the
2465 type of the first field for the tests below. We have already verified
2466 that the modes are the same. */
2467 if ((TREE_CODE (passed_type) == UNION_TYPE
2468 || TREE_CODE (passed_type) == RECORD_TYPE)
2469 && TYPE_TRANSPARENT_AGGR (passed_type))
2470 passed_type = TREE_TYPE (first_field (passed_type));
2472 /* See if this arg was passed by invisible reference. */
2473 if (pass_by_reference (&all->args_so_far_v, passed_mode,
2474 passed_type, data->named_arg))
2476 passed_type = nominal_type = build_pointer_type (passed_type);
2477 data->passed_pointer = true;
2478 passed_mode = nominal_mode = TYPE_MODE (nominal_type);
2481 /* Find mode as it is passed by the ABI. */
2482 unsignedp = TYPE_UNSIGNED (passed_type);
2483 promoted_mode = promote_function_mode (passed_type, passed_mode, &unsignedp,
2484 TREE_TYPE (current_function_decl), 0);
2486 egress:
2487 data->nominal_type = nominal_type;
2488 data->passed_type = passed_type;
2489 data->nominal_mode = nominal_mode;
2490 data->passed_mode = passed_mode;
2491 data->promoted_mode = promoted_mode;
2494 /* A subroutine of assign_parms. Invoke setup_incoming_varargs. */
2496 static void
2497 assign_parms_setup_varargs (struct assign_parm_data_all *all,
2498 struct assign_parm_data_one *data, bool no_rtl)
2500 int varargs_pretend_bytes = 0;
2502 targetm.calls.setup_incoming_varargs (all->args_so_far,
2503 data->promoted_mode,
2504 data->passed_type,
2505 &varargs_pretend_bytes, no_rtl);
2507 /* If the back-end has requested extra stack space, record how much is
2508 needed. Do not change pretend_args_size otherwise since it may be
2509 nonzero from an earlier partial argument. */
2510 if (varargs_pretend_bytes > 0)
2511 all->pretend_args_size = varargs_pretend_bytes;
2514 /* A subroutine of assign_parms. Set DATA->ENTRY_PARM corresponding to
2515 the incoming location of the current parameter. */
2517 static void
2518 assign_parm_find_entry_rtl (struct assign_parm_data_all *all,
2519 struct assign_parm_data_one *data)
2521 HOST_WIDE_INT pretend_bytes = 0;
2522 rtx entry_parm;
2523 bool in_regs;
2525 if (data->promoted_mode == VOIDmode)
2527 data->entry_parm = data->stack_parm = const0_rtx;
2528 return;
2531 entry_parm = targetm.calls.function_incoming_arg (all->args_so_far,
2532 data->promoted_mode,
2533 data->passed_type,
2534 data->named_arg);
2536 if (entry_parm == 0)
2537 data->promoted_mode = data->passed_mode;
2539 /* Determine parm's home in the stack, in case it arrives in the stack
2540 or we should pretend it did. Compute the stack position and rtx where
2541 the argument arrives and its size.
2543 There is one complexity here: If this was a parameter that would
2544 have been passed in registers, but wasn't only because it is
2545 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2546 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2547 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of 0
2548 as it was the previous time. */
2549 in_regs = (entry_parm != 0) || POINTER_BOUNDS_TYPE_P (data->passed_type);
2550 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2551 in_regs = true;
2552 #endif
2553 if (!in_regs && !data->named_arg)
2555 if (targetm.calls.pretend_outgoing_varargs_named (all->args_so_far))
2557 rtx tem;
2558 tem = targetm.calls.function_incoming_arg (all->args_so_far,
2559 data->promoted_mode,
2560 data->passed_type, true);
2561 in_regs = tem != NULL;
2565 /* If this parameter was passed both in registers and in the stack, use
2566 the copy on the stack. */
2567 if (targetm.calls.must_pass_in_stack (data->promoted_mode,
2568 data->passed_type))
2569 entry_parm = 0;
2571 if (entry_parm)
2573 int partial;
2575 partial = targetm.calls.arg_partial_bytes (all->args_so_far,
2576 data->promoted_mode,
2577 data->passed_type,
2578 data->named_arg);
2579 data->partial = partial;
2581 /* The caller might already have allocated stack space for the
2582 register parameters. */
2583 if (partial != 0 && all->reg_parm_stack_space == 0)
2585 /* Part of this argument is passed in registers and part
2586 is passed on the stack. Ask the prologue code to extend
2587 the stack part so that we can recreate the full value.
2589 PRETEND_BYTES is the size of the registers we need to store.
2590 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
2591 stack space that the prologue should allocate.
2593 Internally, gcc assumes that the argument pointer is aligned
2594 to STACK_BOUNDARY bits. This is used both for alignment
2595 optimizations (see init_emit) and to locate arguments that are
2596 aligned to more than PARM_BOUNDARY bits. We must preserve this
2597 invariant by rounding CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to
2598 a stack boundary. */
2600 /* We assume at most one partial arg, and it must be the first
2601 argument on the stack. */
2602 gcc_assert (!all->extra_pretend_bytes && !all->pretend_args_size);
2604 pretend_bytes = partial;
2605 all->pretend_args_size = CEIL_ROUND (pretend_bytes, STACK_BYTES);
2607 /* We want to align relative to the actual stack pointer, so
2608 don't include this in the stack size until later. */
2609 all->extra_pretend_bytes = all->pretend_args_size;
2613 locate_and_pad_parm (data->promoted_mode, data->passed_type, in_regs,
2614 all->reg_parm_stack_space,
2615 entry_parm ? data->partial : 0, current_function_decl,
2616 &all->stack_args_size, &data->locate);
2618 /* Update parm_stack_boundary if this parameter is passed in the
2619 stack. */
2620 if (!in_regs && crtl->parm_stack_boundary < data->locate.boundary)
2621 crtl->parm_stack_boundary = data->locate.boundary;
2623 /* Adjust offsets to include the pretend args. */
2624 pretend_bytes = all->extra_pretend_bytes - pretend_bytes;
2625 data->locate.slot_offset.constant += pretend_bytes;
2626 data->locate.offset.constant += pretend_bytes;
2628 data->entry_parm = entry_parm;
2631 /* A subroutine of assign_parms. If there is actually space on the stack
2632 for this parm, count it in stack_args_size and return true. */
2634 static bool
2635 assign_parm_is_stack_parm (struct assign_parm_data_all *all,
2636 struct assign_parm_data_one *data)
2638 /* Bounds are never passed on the stack to keep compatibility
2639 with not instrumented code. */
2640 if (POINTER_BOUNDS_TYPE_P (data->passed_type))
2641 return false;
2642 /* Trivially true if we've no incoming register. */
2643 else if (data->entry_parm == NULL)
2645 /* Also true if we're partially in registers and partially not,
2646 since we've arranged to drop the entire argument on the stack. */
2647 else if (data->partial != 0)
2649 /* Also true if the target says that it's passed in both registers
2650 and on the stack. */
2651 else if (GET_CODE (data->entry_parm) == PARALLEL
2652 && XEXP (XVECEXP (data->entry_parm, 0, 0), 0) == NULL_RTX)
2654 /* Also true if the target says that there's stack allocated for
2655 all register parameters. */
2656 else if (all->reg_parm_stack_space > 0)
2658 /* Otherwise, no, this parameter has no ABI defined stack slot. */
2659 else
2660 return false;
2662 all->stack_args_size.constant += data->locate.size.constant;
2663 if (data->locate.size.var)
2664 ADD_PARM_SIZE (all->stack_args_size, data->locate.size.var);
2666 return true;
2669 /* A subroutine of assign_parms. Given that this parameter is allocated
2670 stack space by the ABI, find it. */
2672 static void
2673 assign_parm_find_stack_rtl (tree parm, struct assign_parm_data_one *data)
2675 rtx offset_rtx, stack_parm;
2676 unsigned int align, boundary;
2678 /* If we're passing this arg using a reg, make its stack home the
2679 aligned stack slot. */
2680 if (data->entry_parm)
2681 offset_rtx = ARGS_SIZE_RTX (data->locate.slot_offset);
2682 else
2683 offset_rtx = ARGS_SIZE_RTX (data->locate.offset);
2685 stack_parm = crtl->args.internal_arg_pointer;
2686 if (offset_rtx != const0_rtx)
2687 stack_parm = gen_rtx_PLUS (Pmode, stack_parm, offset_rtx);
2688 stack_parm = gen_rtx_MEM (data->promoted_mode, stack_parm);
2690 if (!data->passed_pointer)
2692 set_mem_attributes (stack_parm, parm, 1);
2693 /* set_mem_attributes could set MEM_SIZE to the passed mode's size,
2694 while promoted mode's size is needed. */
2695 if (data->promoted_mode != BLKmode
2696 && data->promoted_mode != DECL_MODE (parm))
2698 set_mem_size (stack_parm, GET_MODE_SIZE (data->promoted_mode));
2699 if (MEM_EXPR (stack_parm) && MEM_OFFSET_KNOWN_P (stack_parm))
2701 int offset = subreg_lowpart_offset (DECL_MODE (parm),
2702 data->promoted_mode);
2703 if (offset)
2704 set_mem_offset (stack_parm, MEM_OFFSET (stack_parm) - offset);
2709 boundary = data->locate.boundary;
2710 align = BITS_PER_UNIT;
2712 /* If we're padding upward, we know that the alignment of the slot
2713 is TARGET_FUNCTION_ARG_BOUNDARY. If we're using slot_offset, we're
2714 intentionally forcing upward padding. Otherwise we have to come
2715 up with a guess at the alignment based on OFFSET_RTX. */
2716 if (data->locate.where_pad != downward || data->entry_parm)
2717 align = boundary;
2718 else if (CONST_INT_P (offset_rtx))
2720 align = INTVAL (offset_rtx) * BITS_PER_UNIT | boundary;
2721 align = align & -align;
2723 set_mem_align (stack_parm, align);
2725 if (data->entry_parm)
2726 set_reg_attrs_for_parm (data->entry_parm, stack_parm);
2728 data->stack_parm = stack_parm;
2731 /* A subroutine of assign_parms. Adjust DATA->ENTRY_RTL such that it's
2732 always valid and contiguous. */
2734 static void
2735 assign_parm_adjust_entry_rtl (struct assign_parm_data_one *data)
2737 rtx entry_parm = data->entry_parm;
2738 rtx stack_parm = data->stack_parm;
2740 /* If this parm was passed part in regs and part in memory, pretend it
2741 arrived entirely in memory by pushing the register-part onto the stack.
2742 In the special case of a DImode or DFmode that is split, we could put
2743 it together in a pseudoreg directly, but for now that's not worth
2744 bothering with. */
2745 if (data->partial != 0)
2747 /* Handle calls that pass values in multiple non-contiguous
2748 locations. The Irix 6 ABI has examples of this. */
2749 if (GET_CODE (entry_parm) == PARALLEL)
2750 emit_group_store (validize_mem (copy_rtx (stack_parm)), entry_parm,
2751 data->passed_type,
2752 int_size_in_bytes (data->passed_type));
2753 else
2755 gcc_assert (data->partial % UNITS_PER_WORD == 0);
2756 move_block_from_reg (REGNO (entry_parm),
2757 validize_mem (copy_rtx (stack_parm)),
2758 data->partial / UNITS_PER_WORD);
2761 entry_parm = stack_parm;
2764 /* If we didn't decide this parm came in a register, by default it came
2765 on the stack. */
2766 else if (entry_parm == NULL)
2767 entry_parm = stack_parm;
2769 /* When an argument is passed in multiple locations, we can't make use
2770 of this information, but we can save some copying if the whole argument
2771 is passed in a single register. */
2772 else if (GET_CODE (entry_parm) == PARALLEL
2773 && data->nominal_mode != BLKmode
2774 && data->passed_mode != BLKmode)
2776 size_t i, len = XVECLEN (entry_parm, 0);
2778 for (i = 0; i < len; i++)
2779 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
2780 && REG_P (XEXP (XVECEXP (entry_parm, 0, i), 0))
2781 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
2782 == data->passed_mode)
2783 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
2785 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
2786 break;
2790 data->entry_parm = entry_parm;
2793 /* A subroutine of assign_parms. Reconstitute any values which were
2794 passed in multiple registers and would fit in a single register. */
2796 static void
2797 assign_parm_remove_parallels (struct assign_parm_data_one *data)
2799 rtx entry_parm = data->entry_parm;
2801 /* Convert the PARALLEL to a REG of the same mode as the parallel.
2802 This can be done with register operations rather than on the
2803 stack, even if we will store the reconstituted parameter on the
2804 stack later. */
2805 if (GET_CODE (entry_parm) == PARALLEL && GET_MODE (entry_parm) != BLKmode)
2807 rtx parmreg = gen_reg_rtx (GET_MODE (entry_parm));
2808 emit_group_store (parmreg, entry_parm, data->passed_type,
2809 GET_MODE_SIZE (GET_MODE (entry_parm)));
2810 entry_parm = parmreg;
2813 data->entry_parm = entry_parm;
2816 /* A subroutine of assign_parms. Adjust DATA->STACK_RTL such that it's
2817 always valid and properly aligned. */
2819 static void
2820 assign_parm_adjust_stack_rtl (struct assign_parm_data_one *data)
2822 rtx stack_parm = data->stack_parm;
2824 /* If we can't trust the parm stack slot to be aligned enough for its
2825 ultimate type, don't use that slot after entry. We'll make another
2826 stack slot, if we need one. */
2827 if (stack_parm
2828 && ((STRICT_ALIGNMENT
2829 && GET_MODE_ALIGNMENT (data->nominal_mode) > MEM_ALIGN (stack_parm))
2830 || (data->nominal_type
2831 && TYPE_ALIGN (data->nominal_type) > MEM_ALIGN (stack_parm)
2832 && MEM_ALIGN (stack_parm) < PREFERRED_STACK_BOUNDARY)))
2833 stack_parm = NULL;
2835 /* If parm was passed in memory, and we need to convert it on entry,
2836 don't store it back in that same slot. */
2837 else if (data->entry_parm == stack_parm
2838 && data->nominal_mode != BLKmode
2839 && data->nominal_mode != data->passed_mode)
2840 stack_parm = NULL;
2842 /* If stack protection is in effect for this function, don't leave any
2843 pointers in their passed stack slots. */
2844 else if (crtl->stack_protect_guard
2845 && (flag_stack_protect == 2
2846 || data->passed_pointer
2847 || POINTER_TYPE_P (data->nominal_type)))
2848 stack_parm = NULL;
2850 data->stack_parm = stack_parm;
2853 /* A subroutine of assign_parms. Return true if the current parameter
2854 should be stored as a BLKmode in the current frame. */
2856 static bool
2857 assign_parm_setup_block_p (struct assign_parm_data_one *data)
2859 if (data->nominal_mode == BLKmode)
2860 return true;
2861 if (GET_MODE (data->entry_parm) == BLKmode)
2862 return true;
2864 #ifdef BLOCK_REG_PADDING
2865 /* Only assign_parm_setup_block knows how to deal with register arguments
2866 that are padded at the least significant end. */
2867 if (REG_P (data->entry_parm)
2868 && GET_MODE_SIZE (data->promoted_mode) < UNITS_PER_WORD
2869 && (BLOCK_REG_PADDING (data->passed_mode, data->passed_type, 1)
2870 == (BYTES_BIG_ENDIAN ? upward : downward)))
2871 return true;
2872 #endif
2874 return false;
2877 /* A subroutine of assign_parms. Arrange for the parameter to be
2878 present and valid in DATA->STACK_RTL. */
2880 static void
2881 assign_parm_setup_block (struct assign_parm_data_all *all,
2882 tree parm, struct assign_parm_data_one *data)
2884 rtx entry_parm = data->entry_parm;
2885 rtx stack_parm = data->stack_parm;
2886 rtx target_reg = NULL_RTX;
2887 bool in_conversion_seq = false;
2888 HOST_WIDE_INT size;
2889 HOST_WIDE_INT size_stored;
2891 if (GET_CODE (entry_parm) == PARALLEL)
2892 entry_parm = emit_group_move_into_temps (entry_parm);
2894 /* If we want the parameter in a pseudo, don't use a stack slot. */
2895 if (is_gimple_reg (parm) && use_register_for_decl (parm))
2897 tree def = ssa_default_def (cfun, parm);
2898 gcc_assert (def);
2899 machine_mode mode = promote_ssa_mode (def, NULL);
2900 rtx reg = gen_reg_rtx (mode);
2901 if (GET_CODE (reg) != CONCAT)
2902 stack_parm = reg;
2903 else
2905 target_reg = reg;
2906 /* Avoid allocating a stack slot, if there isn't one
2907 preallocated by the ABI. It might seem like we should
2908 always prefer a pseudo, but converting between
2909 floating-point and integer modes goes through the stack
2910 on various machines, so it's better to use the reserved
2911 stack slot than to risk wasting it and allocating more
2912 for the conversion. */
2913 if (stack_parm == NULL_RTX)
2915 int save = generating_concat_p;
2916 generating_concat_p = 0;
2917 stack_parm = gen_reg_rtx (mode);
2918 generating_concat_p = save;
2921 data->stack_parm = NULL;
2924 size = int_size_in_bytes (data->passed_type);
2925 size_stored = CEIL_ROUND (size, UNITS_PER_WORD);
2926 if (stack_parm == 0)
2928 SET_DECL_ALIGN (parm, MAX (DECL_ALIGN (parm), BITS_PER_WORD));
2929 stack_parm = assign_stack_local (BLKmode, size_stored,
2930 DECL_ALIGN (parm));
2931 if (GET_MODE_SIZE (GET_MODE (entry_parm)) == size)
2932 PUT_MODE (stack_parm, GET_MODE (entry_parm));
2933 set_mem_attributes (stack_parm, parm, 1);
2936 /* If a BLKmode arrives in registers, copy it to a stack slot. Handle
2937 calls that pass values in multiple non-contiguous locations. */
2938 if (REG_P (entry_parm) || GET_CODE (entry_parm) == PARALLEL)
2940 rtx mem;
2942 /* Note that we will be storing an integral number of words.
2943 So we have to be careful to ensure that we allocate an
2944 integral number of words. We do this above when we call
2945 assign_stack_local if space was not allocated in the argument
2946 list. If it was, this will not work if PARM_BOUNDARY is not
2947 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2948 if it becomes a problem. Exception is when BLKmode arrives
2949 with arguments not conforming to word_mode. */
2951 if (data->stack_parm == 0)
2953 else if (GET_CODE (entry_parm) == PARALLEL)
2955 else
2956 gcc_assert (!size || !(PARM_BOUNDARY % BITS_PER_WORD));
2958 mem = validize_mem (copy_rtx (stack_parm));
2960 /* Handle values in multiple non-contiguous locations. */
2961 if (GET_CODE (entry_parm) == PARALLEL && !MEM_P (mem))
2962 emit_group_store (mem, entry_parm, data->passed_type, size);
2963 else if (GET_CODE (entry_parm) == PARALLEL)
2965 push_to_sequence2 (all->first_conversion_insn,
2966 all->last_conversion_insn);
2967 emit_group_store (mem, entry_parm, data->passed_type, size);
2968 all->first_conversion_insn = get_insns ();
2969 all->last_conversion_insn = get_last_insn ();
2970 end_sequence ();
2971 in_conversion_seq = true;
2974 else if (size == 0)
2977 /* If SIZE is that of a mode no bigger than a word, just use
2978 that mode's store operation. */
2979 else if (size <= UNITS_PER_WORD)
2981 machine_mode mode
2982 = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
2984 if (mode != BLKmode
2985 #ifdef BLOCK_REG_PADDING
2986 && (size == UNITS_PER_WORD
2987 || (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2988 != (BYTES_BIG_ENDIAN ? upward : downward)))
2989 #endif
2992 rtx reg;
2994 /* We are really truncating a word_mode value containing
2995 SIZE bytes into a value of mode MODE. If such an
2996 operation requires no actual instructions, we can refer
2997 to the value directly in mode MODE, otherwise we must
2998 start with the register in word_mode and explicitly
2999 convert it. */
3000 if (TRULY_NOOP_TRUNCATION (size * BITS_PER_UNIT, BITS_PER_WORD))
3001 reg = gen_rtx_REG (mode, REGNO (entry_parm));
3002 else
3004 reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
3005 reg = convert_to_mode (mode, copy_to_reg (reg), 1);
3007 emit_move_insn (change_address (mem, mode, 0), reg);
3010 #ifdef BLOCK_REG_PADDING
3011 /* Storing the register in memory as a full word, as
3012 move_block_from_reg below would do, and then using the
3013 MEM in a smaller mode, has the effect of shifting right
3014 if BYTES_BIG_ENDIAN. If we're bypassing memory, the
3015 shifting must be explicit. */
3016 else if (!MEM_P (mem))
3018 rtx x;
3020 /* If the assert below fails, we should have taken the
3021 mode != BLKmode path above, unless we have downward
3022 padding of smaller-than-word arguments on a machine
3023 with little-endian bytes, which would likely require
3024 additional changes to work correctly. */
3025 gcc_checking_assert (BYTES_BIG_ENDIAN
3026 && (BLOCK_REG_PADDING (mode,
3027 data->passed_type, 1)
3028 == upward));
3030 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
3032 x = gen_rtx_REG (word_mode, REGNO (entry_parm));
3033 x = expand_shift (RSHIFT_EXPR, word_mode, x, by,
3034 NULL_RTX, 1);
3035 x = force_reg (word_mode, x);
3036 x = gen_lowpart_SUBREG (GET_MODE (mem), x);
3038 emit_move_insn (mem, x);
3040 #endif
3042 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
3043 machine must be aligned to the left before storing
3044 to memory. Note that the previous test doesn't
3045 handle all cases (e.g. SIZE == 3). */
3046 else if (size != UNITS_PER_WORD
3047 #ifdef BLOCK_REG_PADDING
3048 && (BLOCK_REG_PADDING (mode, data->passed_type, 1)
3049 == downward)
3050 #else
3051 && BYTES_BIG_ENDIAN
3052 #endif
3055 rtx tem, x;
3056 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
3057 rtx reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
3059 x = expand_shift (LSHIFT_EXPR, word_mode, reg, by, NULL_RTX, 1);
3060 tem = change_address (mem, word_mode, 0);
3061 emit_move_insn (tem, x);
3063 else
3064 move_block_from_reg (REGNO (entry_parm), mem,
3065 size_stored / UNITS_PER_WORD);
3067 else if (!MEM_P (mem))
3069 gcc_checking_assert (size > UNITS_PER_WORD);
3070 #ifdef BLOCK_REG_PADDING
3071 gcc_checking_assert (BLOCK_REG_PADDING (GET_MODE (mem),
3072 data->passed_type, 0)
3073 == upward);
3074 #endif
3075 emit_move_insn (mem, entry_parm);
3077 else
3078 move_block_from_reg (REGNO (entry_parm), mem,
3079 size_stored / UNITS_PER_WORD);
3081 else if (data->stack_parm == 0)
3083 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3084 emit_block_move (stack_parm, data->entry_parm, GEN_INT (size),
3085 BLOCK_OP_NORMAL);
3086 all->first_conversion_insn = get_insns ();
3087 all->last_conversion_insn = get_last_insn ();
3088 end_sequence ();
3089 in_conversion_seq = true;
3092 if (target_reg)
3094 if (!in_conversion_seq)
3095 emit_move_insn (target_reg, stack_parm);
3096 else
3098 push_to_sequence2 (all->first_conversion_insn,
3099 all->last_conversion_insn);
3100 emit_move_insn (target_reg, stack_parm);
3101 all->first_conversion_insn = get_insns ();
3102 all->last_conversion_insn = get_last_insn ();
3103 end_sequence ();
3105 stack_parm = target_reg;
3108 data->stack_parm = stack_parm;
3109 set_parm_rtl (parm, stack_parm);
3112 /* A subroutine of assign_parms. Allocate a pseudo to hold the current
3113 parameter. Get it there. Perform all ABI specified conversions. */
3115 static void
3116 assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm,
3117 struct assign_parm_data_one *data)
3119 rtx parmreg, validated_mem;
3120 rtx equiv_stack_parm;
3121 machine_mode promoted_nominal_mode;
3122 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (parm));
3123 bool did_conversion = false;
3124 bool need_conversion, moved;
3125 rtx rtl;
3127 /* Store the parm in a pseudoregister during the function, but we may
3128 need to do it in a wider mode. Using 2 here makes the result
3129 consistent with promote_decl_mode and thus expand_expr_real_1. */
3130 promoted_nominal_mode
3131 = promote_function_mode (data->nominal_type, data->nominal_mode, &unsignedp,
3132 TREE_TYPE (current_function_decl), 2);
3134 parmreg = gen_reg_rtx (promoted_nominal_mode);
3135 if (!DECL_ARTIFICIAL (parm))
3136 mark_user_reg (parmreg);
3138 /* If this was an item that we received a pointer to,
3139 set rtl appropriately. */
3140 if (data->passed_pointer)
3142 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data->passed_type)), parmreg);
3143 set_mem_attributes (rtl, parm, 1);
3145 else
3146 rtl = parmreg;
3148 assign_parm_remove_parallels (data);
3150 /* Copy the value into the register, thus bridging between
3151 assign_parm_find_data_types and expand_expr_real_1. */
3153 equiv_stack_parm = data->stack_parm;
3154 validated_mem = validize_mem (copy_rtx (data->entry_parm));
3156 need_conversion = (data->nominal_mode != data->passed_mode
3157 || promoted_nominal_mode != data->promoted_mode);
3158 moved = false;
3160 if (need_conversion
3161 && GET_MODE_CLASS (data->nominal_mode) == MODE_INT
3162 && data->nominal_mode == data->passed_mode
3163 && data->nominal_mode == GET_MODE (data->entry_parm))
3165 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
3166 mode, by the caller. We now have to convert it to
3167 NOMINAL_MODE, if different. However, PARMREG may be in
3168 a different mode than NOMINAL_MODE if it is being stored
3169 promoted.
3171 If ENTRY_PARM is a hard register, it might be in a register
3172 not valid for operating in its mode (e.g., an odd-numbered
3173 register for a DFmode). In that case, moves are the only
3174 thing valid, so we can't do a convert from there. This
3175 occurs when the calling sequence allow such misaligned
3176 usages.
3178 In addition, the conversion may involve a call, which could
3179 clobber parameters which haven't been copied to pseudo
3180 registers yet.
3182 First, we try to emit an insn which performs the necessary
3183 conversion. We verify that this insn does not clobber any
3184 hard registers. */
3186 enum insn_code icode;
3187 rtx op0, op1;
3189 icode = can_extend_p (promoted_nominal_mode, data->passed_mode,
3190 unsignedp);
3192 op0 = parmreg;
3193 op1 = validated_mem;
3194 if (icode != CODE_FOR_nothing
3195 && insn_operand_matches (icode, 0, op0)
3196 && insn_operand_matches (icode, 1, op1))
3198 enum rtx_code code = unsignedp ? ZERO_EXTEND : SIGN_EXTEND;
3199 rtx_insn *insn, *insns;
3200 rtx t = op1;
3201 HARD_REG_SET hardregs;
3203 start_sequence ();
3204 /* If op1 is a hard register that is likely spilled, first
3205 force it into a pseudo, otherwise combiner might extend
3206 its lifetime too much. */
3207 if (GET_CODE (t) == SUBREG)
3208 t = SUBREG_REG (t);
3209 if (REG_P (t)
3210 && HARD_REGISTER_P (t)
3211 && ! TEST_HARD_REG_BIT (fixed_reg_set, REGNO (t))
3212 && targetm.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (t))))
3214 t = gen_reg_rtx (GET_MODE (op1));
3215 emit_move_insn (t, op1);
3217 else
3218 t = op1;
3219 rtx_insn *pat = gen_extend_insn (op0, t, promoted_nominal_mode,
3220 data->passed_mode, unsignedp);
3221 emit_insn (pat);
3222 insns = get_insns ();
3224 moved = true;
3225 CLEAR_HARD_REG_SET (hardregs);
3226 for (insn = insns; insn && moved; insn = NEXT_INSN (insn))
3228 if (INSN_P (insn))
3229 note_stores (PATTERN (insn), record_hard_reg_sets,
3230 &hardregs);
3231 if (!hard_reg_set_empty_p (hardregs))
3232 moved = false;
3235 end_sequence ();
3237 if (moved)
3239 emit_insn (insns);
3240 if (equiv_stack_parm != NULL_RTX)
3241 equiv_stack_parm = gen_rtx_fmt_e (code, GET_MODE (parmreg),
3242 equiv_stack_parm);
3247 if (moved)
3248 /* Nothing to do. */
3250 else if (need_conversion)
3252 /* We did not have an insn to convert directly, or the sequence
3253 generated appeared unsafe. We must first copy the parm to a
3254 pseudo reg, and save the conversion until after all
3255 parameters have been moved. */
3257 int save_tree_used;
3258 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
3260 emit_move_insn (tempreg, validated_mem);
3262 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3263 tempreg = convert_to_mode (data->nominal_mode, tempreg, unsignedp);
3265 if (GET_CODE (tempreg) == SUBREG
3266 && GET_MODE (tempreg) == data->nominal_mode
3267 && REG_P (SUBREG_REG (tempreg))
3268 && data->nominal_mode == data->passed_mode
3269 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (data->entry_parm)
3270 && GET_MODE_SIZE (GET_MODE (tempreg))
3271 < GET_MODE_SIZE (GET_MODE (data->entry_parm)))
3273 /* The argument is already sign/zero extended, so note it
3274 into the subreg. */
3275 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
3276 SUBREG_PROMOTED_SET (tempreg, unsignedp);
3279 /* TREE_USED gets set erroneously during expand_assignment. */
3280 save_tree_used = TREE_USED (parm);
3281 SET_DECL_RTL (parm, rtl);
3282 expand_assignment (parm, make_tree (data->nominal_type, tempreg), false);
3283 SET_DECL_RTL (parm, NULL_RTX);
3284 TREE_USED (parm) = save_tree_used;
3285 all->first_conversion_insn = get_insns ();
3286 all->last_conversion_insn = get_last_insn ();
3287 end_sequence ();
3289 did_conversion = true;
3291 else
3292 emit_move_insn (parmreg, validated_mem);
3294 /* If we were passed a pointer but the actual value can safely live
3295 in a register, retrieve it and use it directly. */
3296 if (data->passed_pointer && TYPE_MODE (TREE_TYPE (parm)) != BLKmode)
3298 /* We can't use nominal_mode, because it will have been set to
3299 Pmode above. We must use the actual mode of the parm. */
3300 if (use_register_for_decl (parm))
3302 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
3303 mark_user_reg (parmreg);
3305 else
3307 int align = STACK_SLOT_ALIGNMENT (TREE_TYPE (parm),
3308 TYPE_MODE (TREE_TYPE (parm)),
3309 TYPE_ALIGN (TREE_TYPE (parm)));
3310 parmreg
3311 = assign_stack_local (TYPE_MODE (TREE_TYPE (parm)),
3312 GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (parm))),
3313 align);
3314 set_mem_attributes (parmreg, parm, 1);
3317 if (GET_MODE (parmreg) != GET_MODE (rtl))
3319 rtx tempreg = gen_reg_rtx (GET_MODE (rtl));
3320 int unsigned_p = TYPE_UNSIGNED (TREE_TYPE (parm));
3322 push_to_sequence2 (all->first_conversion_insn,
3323 all->last_conversion_insn);
3324 emit_move_insn (tempreg, rtl);
3325 tempreg = convert_to_mode (GET_MODE (parmreg), tempreg, unsigned_p);
3326 emit_move_insn (parmreg, tempreg);
3327 all->first_conversion_insn = get_insns ();
3328 all->last_conversion_insn = get_last_insn ();
3329 end_sequence ();
3331 did_conversion = true;
3333 else
3334 emit_move_insn (parmreg, rtl);
3336 rtl = parmreg;
3338 /* STACK_PARM is the pointer, not the parm, and PARMREG is
3339 now the parm. */
3340 data->stack_parm = NULL;
3343 set_parm_rtl (parm, rtl);
3345 /* Mark the register as eliminable if we did no conversion and it was
3346 copied from memory at a fixed offset, and the arg pointer was not
3347 copied to a pseudo-reg. If the arg pointer is a pseudo reg or the
3348 offset formed an invalid address, such memory-equivalences as we
3349 make here would screw up life analysis for it. */
3350 if (data->nominal_mode == data->passed_mode
3351 && !did_conversion
3352 && data->stack_parm != 0
3353 && MEM_P (data->stack_parm)
3354 && data->locate.offset.var == 0
3355 && reg_mentioned_p (virtual_incoming_args_rtx,
3356 XEXP (data->stack_parm, 0)))
3358 rtx_insn *linsn = get_last_insn ();
3359 rtx_insn *sinsn;
3360 rtx set;
3362 /* Mark complex types separately. */
3363 if (GET_CODE (parmreg) == CONCAT)
3365 machine_mode submode
3366 = GET_MODE_INNER (GET_MODE (parmreg));
3367 int regnor = REGNO (XEXP (parmreg, 0));
3368 int regnoi = REGNO (XEXP (parmreg, 1));
3369 rtx stackr = adjust_address_nv (data->stack_parm, submode, 0);
3370 rtx stacki = adjust_address_nv (data->stack_parm, submode,
3371 GET_MODE_SIZE (submode));
3373 /* Scan backwards for the set of the real and
3374 imaginary parts. */
3375 for (sinsn = linsn; sinsn != 0;
3376 sinsn = prev_nonnote_insn (sinsn))
3378 set = single_set (sinsn);
3379 if (set == 0)
3380 continue;
3382 if (SET_DEST (set) == regno_reg_rtx [regnoi])
3383 set_unique_reg_note (sinsn, REG_EQUIV, stacki);
3384 else if (SET_DEST (set) == regno_reg_rtx [regnor])
3385 set_unique_reg_note (sinsn, REG_EQUIV, stackr);
3388 else
3389 set_dst_reg_note (linsn, REG_EQUIV, equiv_stack_parm, parmreg);
3392 /* For pointer data type, suggest pointer register. */
3393 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3394 mark_reg_pointer (parmreg,
3395 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
3398 /* A subroutine of assign_parms. Allocate stack space to hold the current
3399 parameter. Get it there. Perform all ABI specified conversions. */
3401 static void
3402 assign_parm_setup_stack (struct assign_parm_data_all *all, tree parm,
3403 struct assign_parm_data_one *data)
3405 /* Value must be stored in the stack slot STACK_PARM during function
3406 execution. */
3407 bool to_conversion = false;
3409 assign_parm_remove_parallels (data);
3411 if (data->promoted_mode != data->nominal_mode)
3413 /* Conversion is required. */
3414 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
3416 emit_move_insn (tempreg, validize_mem (copy_rtx (data->entry_parm)));
3418 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3419 to_conversion = true;
3421 data->entry_parm = convert_to_mode (data->nominal_mode, tempreg,
3422 TYPE_UNSIGNED (TREE_TYPE (parm)));
3424 if (data->stack_parm)
3426 int offset = subreg_lowpart_offset (data->nominal_mode,
3427 GET_MODE (data->stack_parm));
3428 /* ??? This may need a big-endian conversion on sparc64. */
3429 data->stack_parm
3430 = adjust_address (data->stack_parm, data->nominal_mode, 0);
3431 if (offset && MEM_OFFSET_KNOWN_P (data->stack_parm))
3432 set_mem_offset (data->stack_parm,
3433 MEM_OFFSET (data->stack_parm) + offset);
3437 if (data->entry_parm != data->stack_parm)
3439 rtx src, dest;
3441 if (data->stack_parm == 0)
3443 int align = STACK_SLOT_ALIGNMENT (data->passed_type,
3444 GET_MODE (data->entry_parm),
3445 TYPE_ALIGN (data->passed_type));
3446 data->stack_parm
3447 = assign_stack_local (GET_MODE (data->entry_parm),
3448 GET_MODE_SIZE (GET_MODE (data->entry_parm)),
3449 align);
3450 set_mem_attributes (data->stack_parm, parm, 1);
3453 dest = validize_mem (copy_rtx (data->stack_parm));
3454 src = validize_mem (copy_rtx (data->entry_parm));
3456 if (MEM_P (src))
3458 /* Use a block move to handle potentially misaligned entry_parm. */
3459 if (!to_conversion)
3460 push_to_sequence2 (all->first_conversion_insn,
3461 all->last_conversion_insn);
3462 to_conversion = true;
3464 emit_block_move (dest, src,
3465 GEN_INT (int_size_in_bytes (data->passed_type)),
3466 BLOCK_OP_NORMAL);
3468 else
3469 emit_move_insn (dest, src);
3472 if (to_conversion)
3474 all->first_conversion_insn = get_insns ();
3475 all->last_conversion_insn = get_last_insn ();
3476 end_sequence ();
3479 set_parm_rtl (parm, data->stack_parm);
3482 /* A subroutine of assign_parms. If the ABI splits complex arguments, then
3483 undo the frobbing that we did in assign_parms_augmented_arg_list. */
3485 static void
3486 assign_parms_unsplit_complex (struct assign_parm_data_all *all,
3487 vec<tree> fnargs)
3489 tree parm;
3490 tree orig_fnargs = all->orig_fnargs;
3491 unsigned i = 0;
3493 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm), ++i)
3495 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
3496 && targetm.calls.split_complex_arg (TREE_TYPE (parm)))
3498 rtx tmp, real, imag;
3499 machine_mode inner = GET_MODE_INNER (DECL_MODE (parm));
3501 real = DECL_RTL (fnargs[i]);
3502 imag = DECL_RTL (fnargs[i + 1]);
3503 if (inner != GET_MODE (real))
3505 real = gen_lowpart_SUBREG (inner, real);
3506 imag = gen_lowpart_SUBREG (inner, imag);
3509 if (TREE_ADDRESSABLE (parm))
3511 rtx rmem, imem;
3512 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (parm));
3513 int align = STACK_SLOT_ALIGNMENT (TREE_TYPE (parm),
3514 DECL_MODE (parm),
3515 TYPE_ALIGN (TREE_TYPE (parm)));
3517 /* split_complex_arg put the real and imag parts in
3518 pseudos. Move them to memory. */
3519 tmp = assign_stack_local (DECL_MODE (parm), size, align);
3520 set_mem_attributes (tmp, parm, 1);
3521 rmem = adjust_address_nv (tmp, inner, 0);
3522 imem = adjust_address_nv (tmp, inner, GET_MODE_SIZE (inner));
3523 push_to_sequence2 (all->first_conversion_insn,
3524 all->last_conversion_insn);
3525 emit_move_insn (rmem, real);
3526 emit_move_insn (imem, imag);
3527 all->first_conversion_insn = get_insns ();
3528 all->last_conversion_insn = get_last_insn ();
3529 end_sequence ();
3531 else
3532 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
3533 set_parm_rtl (parm, tmp);
3535 real = DECL_INCOMING_RTL (fnargs[i]);
3536 imag = DECL_INCOMING_RTL (fnargs[i + 1]);
3537 if (inner != GET_MODE (real))
3539 real = gen_lowpart_SUBREG (inner, real);
3540 imag = gen_lowpart_SUBREG (inner, imag);
3542 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
3543 set_decl_incoming_rtl (parm, tmp, false);
3544 i++;
3549 /* Load bounds of PARM from bounds table. */
3550 static void
3551 assign_parm_load_bounds (struct assign_parm_data_one *data,
3552 tree parm,
3553 rtx entry,
3554 unsigned bound_no)
3556 bitmap_iterator bi;
3557 unsigned i, offs = 0;
3558 int bnd_no = -1;
3559 rtx slot = NULL, ptr = NULL;
3561 if (parm)
3563 bitmap slots;
3564 bitmap_obstack_initialize (NULL);
3565 slots = BITMAP_ALLOC (NULL);
3566 chkp_find_bound_slots (TREE_TYPE (parm), slots);
3567 EXECUTE_IF_SET_IN_BITMAP (slots, 0, i, bi)
3569 if (bound_no)
3570 bound_no--;
3571 else
3573 bnd_no = i;
3574 break;
3577 BITMAP_FREE (slots);
3578 bitmap_obstack_release (NULL);
3581 /* We may have bounds not associated with any pointer. */
3582 if (bnd_no != -1)
3583 offs = bnd_no * POINTER_SIZE / BITS_PER_UNIT;
3585 /* Find associated pointer. */
3586 if (bnd_no == -1)
3588 /* If bounds are not associated with any bounds,
3589 then it is passed in a register or special slot. */
3590 gcc_assert (data->entry_parm);
3591 ptr = const0_rtx;
3593 else if (MEM_P (entry))
3594 slot = adjust_address (entry, Pmode, offs);
3595 else if (REG_P (entry))
3596 ptr = gen_rtx_REG (Pmode, REGNO (entry) + bnd_no);
3597 else if (GET_CODE (entry) == PARALLEL)
3598 ptr = chkp_get_value_with_offs (entry, GEN_INT (offs));
3599 else
3600 gcc_unreachable ();
3601 data->entry_parm = targetm.calls.load_bounds_for_arg (slot, ptr,
3602 data->entry_parm);
3605 /* Assign RTL expressions to the function's bounds parameters BNDARGS. */
3607 static void
3608 assign_bounds (vec<bounds_parm_data> &bndargs,
3609 struct assign_parm_data_all &all,
3610 bool assign_regs, bool assign_special,
3611 bool assign_bt)
3613 unsigned i, pass;
3614 bounds_parm_data *pbdata;
3616 if (!bndargs.exists ())
3617 return;
3619 /* We make few passes to store input bounds. Firstly handle bounds
3620 passed in registers. After that we load bounds passed in special
3621 slots. Finally we load bounds from Bounds Table. */
3622 for (pass = 0; pass < 3; pass++)
3623 FOR_EACH_VEC_ELT (bndargs, i, pbdata)
3625 /* Pass 0 => regs only. */
3626 if (pass == 0
3627 && (!assign_regs
3628 ||(!pbdata->parm_data.entry_parm
3629 || GET_CODE (pbdata->parm_data.entry_parm) != REG)))
3630 continue;
3631 /* Pass 1 => slots only. */
3632 else if (pass == 1
3633 && (!assign_special
3634 || (!pbdata->parm_data.entry_parm
3635 || GET_CODE (pbdata->parm_data.entry_parm) == REG)))
3636 continue;
3637 /* Pass 2 => BT only. */
3638 else if (pass == 2
3639 && (!assign_bt
3640 || pbdata->parm_data.entry_parm))
3641 continue;
3643 if (!pbdata->parm_data.entry_parm
3644 || GET_CODE (pbdata->parm_data.entry_parm) != REG)
3645 assign_parm_load_bounds (&pbdata->parm_data, pbdata->ptr_parm,
3646 pbdata->ptr_entry, pbdata->bound_no);
3648 set_decl_incoming_rtl (pbdata->bounds_parm,
3649 pbdata->parm_data.entry_parm, false);
3651 if (assign_parm_setup_block_p (&pbdata->parm_data))
3652 assign_parm_setup_block (&all, pbdata->bounds_parm,
3653 &pbdata->parm_data);
3654 else if (pbdata->parm_data.passed_pointer
3655 || use_register_for_decl (pbdata->bounds_parm))
3656 assign_parm_setup_reg (&all, pbdata->bounds_parm,
3657 &pbdata->parm_data);
3658 else
3659 assign_parm_setup_stack (&all, pbdata->bounds_parm,
3660 &pbdata->parm_data);
3664 /* Assign RTL expressions to the function's parameters. This may involve
3665 copying them into registers and using those registers as the DECL_RTL. */
3667 static void
3668 assign_parms (tree fndecl)
3670 struct assign_parm_data_all all;
3671 tree parm;
3672 vec<tree> fnargs;
3673 unsigned i, bound_no = 0;
3674 tree last_arg = NULL;
3675 rtx last_arg_entry = NULL;
3676 vec<bounds_parm_data> bndargs = vNULL;
3677 bounds_parm_data bdata;
3679 crtl->args.internal_arg_pointer
3680 = targetm.calls.internal_arg_pointer ();
3682 assign_parms_initialize_all (&all);
3683 fnargs = assign_parms_augmented_arg_list (&all);
3685 FOR_EACH_VEC_ELT (fnargs, i, parm)
3687 struct assign_parm_data_one data;
3689 /* Extract the type of PARM; adjust it according to ABI. */
3690 assign_parm_find_data_types (&all, parm, &data);
3692 /* Early out for errors and void parameters. */
3693 if (data.passed_mode == VOIDmode)
3695 SET_DECL_RTL (parm, const0_rtx);
3696 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
3697 continue;
3700 /* Estimate stack alignment from parameter alignment. */
3701 if (SUPPORTS_STACK_ALIGNMENT)
3703 unsigned int align
3704 = targetm.calls.function_arg_boundary (data.promoted_mode,
3705 data.passed_type);
3706 align = MINIMUM_ALIGNMENT (data.passed_type, data.promoted_mode,
3707 align);
3708 if (TYPE_ALIGN (data.nominal_type) > align)
3709 align = MINIMUM_ALIGNMENT (data.nominal_type,
3710 TYPE_MODE (data.nominal_type),
3711 TYPE_ALIGN (data.nominal_type));
3712 if (crtl->stack_alignment_estimated < align)
3714 gcc_assert (!crtl->stack_realign_processed);
3715 crtl->stack_alignment_estimated = align;
3719 /* Find out where the parameter arrives in this function. */
3720 assign_parm_find_entry_rtl (&all, &data);
3722 /* Find out where stack space for this parameter might be. */
3723 if (assign_parm_is_stack_parm (&all, &data))
3725 assign_parm_find_stack_rtl (parm, &data);
3726 assign_parm_adjust_entry_rtl (&data);
3728 if (!POINTER_BOUNDS_TYPE_P (data.passed_type))
3730 /* Remember where last non bounds arg was passed in case
3731 we have to load associated bounds for it from Bounds
3732 Table. */
3733 last_arg = parm;
3734 last_arg_entry = data.entry_parm;
3735 bound_no = 0;
3737 /* Record permanently how this parm was passed. */
3738 if (data.passed_pointer)
3740 rtx incoming_rtl
3741 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data.passed_type)),
3742 data.entry_parm);
3743 set_decl_incoming_rtl (parm, incoming_rtl, true);
3745 else
3746 set_decl_incoming_rtl (parm, data.entry_parm, false);
3748 assign_parm_adjust_stack_rtl (&data);
3750 /* Bounds should be loaded in the particular order to
3751 have registers allocated correctly. Collect info about
3752 input bounds and load them later. */
3753 if (POINTER_BOUNDS_TYPE_P (data.passed_type))
3755 /* Expect bounds in instrumented functions only. */
3756 gcc_assert (chkp_function_instrumented_p (fndecl));
3758 bdata.parm_data = data;
3759 bdata.bounds_parm = parm;
3760 bdata.ptr_parm = last_arg;
3761 bdata.ptr_entry = last_arg_entry;
3762 bdata.bound_no = bound_no;
3763 bndargs.safe_push (bdata);
3765 else
3767 if (assign_parm_setup_block_p (&data))
3768 assign_parm_setup_block (&all, parm, &data);
3769 else if (data.passed_pointer || use_register_for_decl (parm))
3770 assign_parm_setup_reg (&all, parm, &data);
3771 else
3772 assign_parm_setup_stack (&all, parm, &data);
3775 if (cfun->stdarg && !DECL_CHAIN (parm))
3777 int pretend_bytes = 0;
3779 assign_parms_setup_varargs (&all, &data, false);
3781 if (chkp_function_instrumented_p (fndecl))
3783 /* We expect this is the last parm. Otherwise it is wrong
3784 to assign bounds right now. */
3785 gcc_assert (i == (fnargs.length () - 1));
3786 assign_bounds (bndargs, all, true, false, false);
3787 targetm.calls.setup_incoming_vararg_bounds (all.args_so_far,
3788 data.promoted_mode,
3789 data.passed_type,
3790 &pretend_bytes,
3791 false);
3792 assign_bounds (bndargs, all, false, true, true);
3793 bndargs.release ();
3797 /* Update info on where next arg arrives in registers. */
3798 targetm.calls.function_arg_advance (all.args_so_far, data.promoted_mode,
3799 data.passed_type, data.named_arg);
3801 if (POINTER_BOUNDS_TYPE_P (data.passed_type))
3802 bound_no++;
3805 assign_bounds (bndargs, all, true, true, true);
3806 bndargs.release ();
3808 if (targetm.calls.split_complex_arg)
3809 assign_parms_unsplit_complex (&all, fnargs);
3811 fnargs.release ();
3813 /* Output all parameter conversion instructions (possibly including calls)
3814 now that all parameters have been copied out of hard registers. */
3815 emit_insn (all.first_conversion_insn);
3817 /* Estimate reload stack alignment from scalar return mode. */
3818 if (SUPPORTS_STACK_ALIGNMENT)
3820 if (DECL_RESULT (fndecl))
3822 tree type = TREE_TYPE (DECL_RESULT (fndecl));
3823 machine_mode mode = TYPE_MODE (type);
3825 if (mode != BLKmode
3826 && mode != VOIDmode
3827 && !AGGREGATE_TYPE_P (type))
3829 unsigned int align = GET_MODE_ALIGNMENT (mode);
3830 if (crtl->stack_alignment_estimated < align)
3832 gcc_assert (!crtl->stack_realign_processed);
3833 crtl->stack_alignment_estimated = align;
3839 /* If we are receiving a struct value address as the first argument, set up
3840 the RTL for the function result. As this might require code to convert
3841 the transmitted address to Pmode, we do this here to ensure that possible
3842 preliminary conversions of the address have been emitted already. */
3843 if (all.function_result_decl)
3845 tree result = DECL_RESULT (current_function_decl);
3846 rtx addr = DECL_RTL (all.function_result_decl);
3847 rtx x;
3849 if (DECL_BY_REFERENCE (result))
3851 SET_DECL_VALUE_EXPR (result, all.function_result_decl);
3852 x = addr;
3854 else
3856 SET_DECL_VALUE_EXPR (result,
3857 build1 (INDIRECT_REF, TREE_TYPE (result),
3858 all.function_result_decl));
3859 addr = convert_memory_address (Pmode, addr);
3860 x = gen_rtx_MEM (DECL_MODE (result), addr);
3861 set_mem_attributes (x, result, 1);
3864 DECL_HAS_VALUE_EXPR_P (result) = 1;
3866 set_parm_rtl (result, x);
3869 /* We have aligned all the args, so add space for the pretend args. */
3870 crtl->args.pretend_args_size = all.pretend_args_size;
3871 all.stack_args_size.constant += all.extra_pretend_bytes;
3872 crtl->args.size = all.stack_args_size.constant;
3874 /* Adjust function incoming argument size for alignment and
3875 minimum length. */
3877 crtl->args.size = MAX (crtl->args.size, all.reg_parm_stack_space);
3878 crtl->args.size = CEIL_ROUND (crtl->args.size,
3879 PARM_BOUNDARY / BITS_PER_UNIT);
3881 if (ARGS_GROW_DOWNWARD)
3883 crtl->args.arg_offset_rtx
3884 = (all.stack_args_size.var == 0 ? GEN_INT (-all.stack_args_size.constant)
3885 : expand_expr (size_diffop (all.stack_args_size.var,
3886 size_int (-all.stack_args_size.constant)),
3887 NULL_RTX, VOIDmode, EXPAND_NORMAL));
3889 else
3890 crtl->args.arg_offset_rtx = ARGS_SIZE_RTX (all.stack_args_size);
3892 /* See how many bytes, if any, of its args a function should try to pop
3893 on return. */
3895 crtl->args.pops_args = targetm.calls.return_pops_args (fndecl,
3896 TREE_TYPE (fndecl),
3897 crtl->args.size);
3899 /* For stdarg.h function, save info about
3900 regs and stack space used by the named args. */
3902 crtl->args.info = all.args_so_far_v;
3904 /* Set the rtx used for the function return value. Put this in its
3905 own variable so any optimizers that need this information don't have
3906 to include tree.h. Do this here so it gets done when an inlined
3907 function gets output. */
3909 crtl->return_rtx
3910 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
3911 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
3913 /* If scalar return value was computed in a pseudo-reg, or was a named
3914 return value that got dumped to the stack, copy that to the hard
3915 return register. */
3916 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
3918 tree decl_result = DECL_RESULT (fndecl);
3919 rtx decl_rtl = DECL_RTL (decl_result);
3921 if (REG_P (decl_rtl)
3922 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
3923 : DECL_REGISTER (decl_result))
3925 rtx real_decl_rtl;
3927 real_decl_rtl = targetm.calls.function_value (TREE_TYPE (decl_result),
3928 fndecl, true);
3929 if (chkp_function_instrumented_p (fndecl))
3930 crtl->return_bnd
3931 = targetm.calls.chkp_function_value_bounds (TREE_TYPE (decl_result),
3932 fndecl, true);
3933 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
3934 /* The delay slot scheduler assumes that crtl->return_rtx
3935 holds the hard register containing the return value, not a
3936 temporary pseudo. */
3937 crtl->return_rtx = real_decl_rtl;
3942 /* A subroutine of gimplify_parameters, invoked via walk_tree.
3943 For all seen types, gimplify their sizes. */
3945 static tree
3946 gimplify_parm_type (tree *tp, int *walk_subtrees, void *data)
3948 tree t = *tp;
3950 *walk_subtrees = 0;
3951 if (TYPE_P (t))
3953 if (POINTER_TYPE_P (t))
3954 *walk_subtrees = 1;
3955 else if (TYPE_SIZE (t) && !TREE_CONSTANT (TYPE_SIZE (t))
3956 && !TYPE_SIZES_GIMPLIFIED (t))
3958 gimplify_type_sizes (t, (gimple_seq *) data);
3959 *walk_subtrees = 1;
3963 return NULL;
3966 /* Gimplify the parameter list for current_function_decl. This involves
3967 evaluating SAVE_EXPRs of variable sized parameters and generating code
3968 to implement callee-copies reference parameters. Returns a sequence of
3969 statements to add to the beginning of the function. */
3971 gimple_seq
3972 gimplify_parameters (void)
3974 struct assign_parm_data_all all;
3975 tree parm;
3976 gimple_seq stmts = NULL;
3977 vec<tree> fnargs;
3978 unsigned i;
3980 assign_parms_initialize_all (&all);
3981 fnargs = assign_parms_augmented_arg_list (&all);
3983 FOR_EACH_VEC_ELT (fnargs, i, parm)
3985 struct assign_parm_data_one data;
3987 /* Extract the type of PARM; adjust it according to ABI. */
3988 assign_parm_find_data_types (&all, parm, &data);
3990 /* Early out for errors and void parameters. */
3991 if (data.passed_mode == VOIDmode || DECL_SIZE (parm) == NULL)
3992 continue;
3994 /* Update info on where next arg arrives in registers. */
3995 targetm.calls.function_arg_advance (all.args_so_far, data.promoted_mode,
3996 data.passed_type, data.named_arg);
3998 /* ??? Once upon a time variable_size stuffed parameter list
3999 SAVE_EXPRs (amongst others) onto a pending sizes list. This
4000 turned out to be less than manageable in the gimple world.
4001 Now we have to hunt them down ourselves. */
4002 walk_tree_without_duplicates (&data.passed_type,
4003 gimplify_parm_type, &stmts);
4005 if (TREE_CODE (DECL_SIZE_UNIT (parm)) != INTEGER_CST)
4007 gimplify_one_sizepos (&DECL_SIZE (parm), &stmts);
4008 gimplify_one_sizepos (&DECL_SIZE_UNIT (parm), &stmts);
4011 if (data.passed_pointer)
4013 tree type = TREE_TYPE (data.passed_type);
4014 if (reference_callee_copied (&all.args_so_far_v, TYPE_MODE (type),
4015 type, data.named_arg))
4017 tree local, t;
4019 /* For constant-sized objects, this is trivial; for
4020 variable-sized objects, we have to play games. */
4021 if (TREE_CODE (DECL_SIZE_UNIT (parm)) == INTEGER_CST
4022 && !(flag_stack_check == GENERIC_STACK_CHECK
4023 && compare_tree_int (DECL_SIZE_UNIT (parm),
4024 STACK_CHECK_MAX_VAR_SIZE) > 0))
4026 local = create_tmp_var (type, get_name (parm));
4027 DECL_IGNORED_P (local) = 0;
4028 /* If PARM was addressable, move that flag over
4029 to the local copy, as its address will be taken,
4030 not the PARMs. Keep the parms address taken
4031 as we'll query that flag during gimplification. */
4032 if (TREE_ADDRESSABLE (parm))
4033 TREE_ADDRESSABLE (local) = 1;
4034 else if (TREE_CODE (type) == COMPLEX_TYPE
4035 || TREE_CODE (type) == VECTOR_TYPE)
4036 DECL_GIMPLE_REG_P (local) = 1;
4038 else
4040 tree ptr_type, addr;
4042 ptr_type = build_pointer_type (type);
4043 addr = create_tmp_reg (ptr_type, get_name (parm));
4044 DECL_IGNORED_P (addr) = 0;
4045 local = build_fold_indirect_ref (addr);
4047 t = builtin_decl_explicit (BUILT_IN_ALLOCA_WITH_ALIGN);
4048 t = build_call_expr (t, 2, DECL_SIZE_UNIT (parm),
4049 size_int (DECL_ALIGN (parm)));
4051 /* The call has been built for a variable-sized object. */
4052 CALL_ALLOCA_FOR_VAR_P (t) = 1;
4053 t = fold_convert (ptr_type, t);
4054 t = build2 (MODIFY_EXPR, TREE_TYPE (addr), addr, t);
4055 gimplify_and_add (t, &stmts);
4058 gimplify_assign (local, parm, &stmts);
4060 SET_DECL_VALUE_EXPR (parm, local);
4061 DECL_HAS_VALUE_EXPR_P (parm) = 1;
4066 fnargs.release ();
4068 return stmts;
4071 /* Compute the size and offset from the start of the stacked arguments for a
4072 parm passed in mode PASSED_MODE and with type TYPE.
4074 INITIAL_OFFSET_PTR points to the current offset into the stacked
4075 arguments.
4077 The starting offset and size for this parm are returned in
4078 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
4079 nonzero, the offset is that of stack slot, which is returned in
4080 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
4081 padding required from the initial offset ptr to the stack slot.
4083 IN_REGS is nonzero if the argument will be passed in registers. It will
4084 never be set if REG_PARM_STACK_SPACE is not defined.
4086 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
4087 for arguments which are passed in registers.
4089 FNDECL is the function in which the argument was defined.
4091 There are two types of rounding that are done. The first, controlled by
4092 TARGET_FUNCTION_ARG_BOUNDARY, forces the offset from the start of the
4093 argument list to be aligned to the specific boundary (in bits). This
4094 rounding affects the initial and starting offsets, but not the argument
4095 size.
4097 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
4098 optionally rounds the size of the parm to PARM_BOUNDARY. The
4099 initial offset is not affected by this rounding, while the size always
4100 is and the starting offset may be. */
4102 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
4103 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
4104 callers pass in the total size of args so far as
4105 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
4107 void
4108 locate_and_pad_parm (machine_mode passed_mode, tree type, int in_regs,
4109 int reg_parm_stack_space, int partial,
4110 tree fndecl ATTRIBUTE_UNUSED,
4111 struct args_size *initial_offset_ptr,
4112 struct locate_and_pad_arg_data *locate)
4114 tree sizetree;
4115 enum direction where_pad;
4116 unsigned int boundary, round_boundary;
4117 int part_size_in_regs;
4119 /* If we have found a stack parm before we reach the end of the
4120 area reserved for registers, skip that area. */
4121 if (! in_regs)
4123 if (reg_parm_stack_space > 0)
4125 if (initial_offset_ptr->var)
4127 initial_offset_ptr->var
4128 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
4129 ssize_int (reg_parm_stack_space));
4130 initial_offset_ptr->constant = 0;
4132 else if (initial_offset_ptr->constant < reg_parm_stack_space)
4133 initial_offset_ptr->constant = reg_parm_stack_space;
4137 part_size_in_regs = (reg_parm_stack_space == 0 ? partial : 0);
4139 sizetree
4140 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
4141 where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
4142 boundary = targetm.calls.function_arg_boundary (passed_mode, type);
4143 round_boundary = targetm.calls.function_arg_round_boundary (passed_mode,
4144 type);
4145 locate->where_pad = where_pad;
4147 /* Alignment can't exceed MAX_SUPPORTED_STACK_ALIGNMENT. */
4148 if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
4149 boundary = MAX_SUPPORTED_STACK_ALIGNMENT;
4151 locate->boundary = boundary;
4153 if (SUPPORTS_STACK_ALIGNMENT)
4155 /* stack_alignment_estimated can't change after stack has been
4156 realigned. */
4157 if (crtl->stack_alignment_estimated < boundary)
4159 if (!crtl->stack_realign_processed)
4160 crtl->stack_alignment_estimated = boundary;
4161 else
4163 /* If stack is realigned and stack alignment value
4164 hasn't been finalized, it is OK not to increase
4165 stack_alignment_estimated. The bigger alignment
4166 requirement is recorded in stack_alignment_needed
4167 below. */
4168 gcc_assert (!crtl->stack_realign_finalized
4169 && crtl->stack_realign_needed);
4174 /* Remember if the outgoing parameter requires extra alignment on the
4175 calling function side. */
4176 if (crtl->stack_alignment_needed < boundary)
4177 crtl->stack_alignment_needed = boundary;
4178 if (crtl->preferred_stack_boundary < boundary)
4179 crtl->preferred_stack_boundary = boundary;
4181 if (ARGS_GROW_DOWNWARD)
4183 locate->slot_offset.constant = -initial_offset_ptr->constant;
4184 if (initial_offset_ptr->var)
4185 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
4186 initial_offset_ptr->var);
4189 tree s2 = sizetree;
4190 if (where_pad != none
4191 && (!tree_fits_uhwi_p (sizetree)
4192 || (tree_to_uhwi (sizetree) * BITS_PER_UNIT) % round_boundary))
4193 s2 = round_up (s2, round_boundary / BITS_PER_UNIT);
4194 SUB_PARM_SIZE (locate->slot_offset, s2);
4197 locate->slot_offset.constant += part_size_in_regs;
4199 if (!in_regs || reg_parm_stack_space > 0)
4200 pad_to_arg_alignment (&locate->slot_offset, boundary,
4201 &locate->alignment_pad);
4203 locate->size.constant = (-initial_offset_ptr->constant
4204 - locate->slot_offset.constant);
4205 if (initial_offset_ptr->var)
4206 locate->size.var = size_binop (MINUS_EXPR,
4207 size_binop (MINUS_EXPR,
4208 ssize_int (0),
4209 initial_offset_ptr->var),
4210 locate->slot_offset.var);
4212 /* Pad_below needs the pre-rounded size to know how much to pad
4213 below. */
4214 locate->offset = locate->slot_offset;
4215 if (where_pad == downward)
4216 pad_below (&locate->offset, passed_mode, sizetree);
4219 else
4221 if (!in_regs || reg_parm_stack_space > 0)
4222 pad_to_arg_alignment (initial_offset_ptr, boundary,
4223 &locate->alignment_pad);
4224 locate->slot_offset = *initial_offset_ptr;
4226 #ifdef PUSH_ROUNDING
4227 if (passed_mode != BLKmode)
4228 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
4229 #endif
4231 /* Pad_below needs the pre-rounded size to know how much to pad below
4232 so this must be done before rounding up. */
4233 locate->offset = locate->slot_offset;
4234 if (where_pad == downward)
4235 pad_below (&locate->offset, passed_mode, sizetree);
4237 if (where_pad != none
4238 && (!tree_fits_uhwi_p (sizetree)
4239 || (tree_to_uhwi (sizetree) * BITS_PER_UNIT) % round_boundary))
4240 sizetree = round_up (sizetree, round_boundary / BITS_PER_UNIT);
4242 ADD_PARM_SIZE (locate->size, sizetree);
4244 locate->size.constant -= part_size_in_regs;
4247 #ifdef FUNCTION_ARG_OFFSET
4248 locate->offset.constant += FUNCTION_ARG_OFFSET (passed_mode, type);
4249 #endif
4252 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
4253 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
4255 static void
4256 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
4257 struct args_size *alignment_pad)
4259 tree save_var = NULL_TREE;
4260 HOST_WIDE_INT save_constant = 0;
4261 int boundary_in_bytes = boundary / BITS_PER_UNIT;
4262 HOST_WIDE_INT sp_offset = STACK_POINTER_OFFSET;
4264 #ifdef SPARC_STACK_BOUNDARY_HACK
4265 /* ??? The SPARC port may claim a STACK_BOUNDARY higher than
4266 the real alignment of %sp. However, when it does this, the
4267 alignment of %sp+STACK_POINTER_OFFSET is STACK_BOUNDARY. */
4268 if (SPARC_STACK_BOUNDARY_HACK)
4269 sp_offset = 0;
4270 #endif
4272 if (boundary > PARM_BOUNDARY)
4274 save_var = offset_ptr->var;
4275 save_constant = offset_ptr->constant;
4278 alignment_pad->var = NULL_TREE;
4279 alignment_pad->constant = 0;
4281 if (boundary > BITS_PER_UNIT)
4283 if (offset_ptr->var)
4285 tree sp_offset_tree = ssize_int (sp_offset);
4286 tree offset = size_binop (PLUS_EXPR,
4287 ARGS_SIZE_TREE (*offset_ptr),
4288 sp_offset_tree);
4289 tree rounded;
4290 if (ARGS_GROW_DOWNWARD)
4291 rounded = round_down (offset, boundary / BITS_PER_UNIT);
4292 else
4293 rounded = round_up (offset, boundary / BITS_PER_UNIT);
4295 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
4296 /* ARGS_SIZE_TREE includes constant term. */
4297 offset_ptr->constant = 0;
4298 if (boundary > PARM_BOUNDARY)
4299 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
4300 save_var);
4302 else
4304 offset_ptr->constant = -sp_offset +
4305 (ARGS_GROW_DOWNWARD
4306 ? FLOOR_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes)
4307 : CEIL_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes));
4309 if (boundary > PARM_BOUNDARY)
4310 alignment_pad->constant = offset_ptr->constant - save_constant;
4315 static void
4316 pad_below (struct args_size *offset_ptr, machine_mode passed_mode, tree sizetree)
4318 if (passed_mode != BLKmode)
4320 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
4321 offset_ptr->constant
4322 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
4323 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
4324 - GET_MODE_SIZE (passed_mode));
4326 else
4328 if (TREE_CODE (sizetree) != INTEGER_CST
4329 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
4331 /* Round the size up to multiple of PARM_BOUNDARY bits. */
4332 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
4333 /* Add it in. */
4334 ADD_PARM_SIZE (*offset_ptr, s2);
4335 SUB_PARM_SIZE (*offset_ptr, sizetree);
4341 /* True if register REGNO was alive at a place where `setjmp' was
4342 called and was set more than once or is an argument. Such regs may
4343 be clobbered by `longjmp'. */
4345 static bool
4346 regno_clobbered_at_setjmp (bitmap setjmp_crosses, int regno)
4348 /* There appear to be cases where some local vars never reach the
4349 backend but have bogus regnos. */
4350 if (regno >= max_reg_num ())
4351 return false;
4353 return ((REG_N_SETS (regno) > 1
4354 || REGNO_REG_SET_P (df_get_live_out (ENTRY_BLOCK_PTR_FOR_FN (cfun)),
4355 regno))
4356 && REGNO_REG_SET_P (setjmp_crosses, regno));
4359 /* Walk the tree of blocks describing the binding levels within a
4360 function and warn about variables the might be killed by setjmp or
4361 vfork. This is done after calling flow_analysis before register
4362 allocation since that will clobber the pseudo-regs to hard
4363 regs. */
4365 static void
4366 setjmp_vars_warning (bitmap setjmp_crosses, tree block)
4368 tree decl, sub;
4370 for (decl = BLOCK_VARS (block); decl; decl = DECL_CHAIN (decl))
4372 if (TREE_CODE (decl) == VAR_DECL
4373 && DECL_RTL_SET_P (decl)
4374 && REG_P (DECL_RTL (decl))
4375 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
4376 warning (OPT_Wclobbered, "variable %q+D might be clobbered by"
4377 " %<longjmp%> or %<vfork%>", decl);
4380 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = BLOCK_CHAIN (sub))
4381 setjmp_vars_warning (setjmp_crosses, sub);
4384 /* Do the appropriate part of setjmp_vars_warning
4385 but for arguments instead of local variables. */
4387 static void
4388 setjmp_args_warning (bitmap setjmp_crosses)
4390 tree decl;
4391 for (decl = DECL_ARGUMENTS (current_function_decl);
4392 decl; decl = DECL_CHAIN (decl))
4393 if (DECL_RTL (decl) != 0
4394 && REG_P (DECL_RTL (decl))
4395 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
4396 warning (OPT_Wclobbered,
4397 "argument %q+D might be clobbered by %<longjmp%> or %<vfork%>",
4398 decl);
4401 /* Generate warning messages for variables live across setjmp. */
4403 void
4404 generate_setjmp_warnings (void)
4406 bitmap setjmp_crosses = regstat_get_setjmp_crosses ();
4408 if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS
4409 || bitmap_empty_p (setjmp_crosses))
4410 return;
4412 setjmp_vars_warning (setjmp_crosses, DECL_INITIAL (current_function_decl));
4413 setjmp_args_warning (setjmp_crosses);
4417 /* Reverse the order of elements in the fragment chain T of blocks,
4418 and return the new head of the chain (old last element).
4419 In addition to that clear BLOCK_SAME_RANGE flags when needed
4420 and adjust BLOCK_SUPERCONTEXT from the super fragment to
4421 its super fragment origin. */
4423 static tree
4424 block_fragments_nreverse (tree t)
4426 tree prev = 0, block, next, prev_super = 0;
4427 tree super = BLOCK_SUPERCONTEXT (t);
4428 if (BLOCK_FRAGMENT_ORIGIN (super))
4429 super = BLOCK_FRAGMENT_ORIGIN (super);
4430 for (block = t; block; block = next)
4432 next = BLOCK_FRAGMENT_CHAIN (block);
4433 BLOCK_FRAGMENT_CHAIN (block) = prev;
4434 if ((prev && !BLOCK_SAME_RANGE (prev))
4435 || (BLOCK_FRAGMENT_CHAIN (BLOCK_SUPERCONTEXT (block))
4436 != prev_super))
4437 BLOCK_SAME_RANGE (block) = 0;
4438 prev_super = BLOCK_SUPERCONTEXT (block);
4439 BLOCK_SUPERCONTEXT (block) = super;
4440 prev = block;
4442 t = BLOCK_FRAGMENT_ORIGIN (t);
4443 if (BLOCK_FRAGMENT_CHAIN (BLOCK_SUPERCONTEXT (t))
4444 != prev_super)
4445 BLOCK_SAME_RANGE (t) = 0;
4446 BLOCK_SUPERCONTEXT (t) = super;
4447 return prev;
4450 /* Reverse the order of elements in the chain T of blocks,
4451 and return the new head of the chain (old last element).
4452 Also do the same on subblocks and reverse the order of elements
4453 in BLOCK_FRAGMENT_CHAIN as well. */
4455 static tree
4456 blocks_nreverse_all (tree t)
4458 tree prev = 0, block, next;
4459 for (block = t; block; block = next)
4461 next = BLOCK_CHAIN (block);
4462 BLOCK_CHAIN (block) = prev;
4463 if (BLOCK_FRAGMENT_CHAIN (block)
4464 && BLOCK_FRAGMENT_ORIGIN (block) == NULL_TREE)
4466 BLOCK_FRAGMENT_CHAIN (block)
4467 = block_fragments_nreverse (BLOCK_FRAGMENT_CHAIN (block));
4468 if (!BLOCK_SAME_RANGE (BLOCK_FRAGMENT_CHAIN (block)))
4469 BLOCK_SAME_RANGE (block) = 0;
4471 BLOCK_SUBBLOCKS (block) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block));
4472 prev = block;
4474 return prev;
4478 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
4479 and create duplicate blocks. */
4480 /* ??? Need an option to either create block fragments or to create
4481 abstract origin duplicates of a source block. It really depends
4482 on what optimization has been performed. */
4484 void
4485 reorder_blocks (void)
4487 tree block = DECL_INITIAL (current_function_decl);
4489 if (block == NULL_TREE)
4490 return;
4492 auto_vec<tree, 10> block_stack;
4494 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
4495 clear_block_marks (block);
4497 /* Prune the old trees away, so that they don't get in the way. */
4498 BLOCK_SUBBLOCKS (block) = NULL_TREE;
4499 BLOCK_CHAIN (block) = NULL_TREE;
4501 /* Recreate the block tree from the note nesting. */
4502 reorder_blocks_1 (get_insns (), block, &block_stack);
4503 BLOCK_SUBBLOCKS (block) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block));
4506 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
4508 void
4509 clear_block_marks (tree block)
4511 while (block)
4513 TREE_ASM_WRITTEN (block) = 0;
4514 clear_block_marks (BLOCK_SUBBLOCKS (block));
4515 block = BLOCK_CHAIN (block);
4519 static void
4520 reorder_blocks_1 (rtx_insn *insns, tree current_block,
4521 vec<tree> *p_block_stack)
4523 rtx_insn *insn;
4524 tree prev_beg = NULL_TREE, prev_end = NULL_TREE;
4526 for (insn = insns; insn; insn = NEXT_INSN (insn))
4528 if (NOTE_P (insn))
4530 if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_BEG)
4532 tree block = NOTE_BLOCK (insn);
4533 tree origin;
4535 gcc_assert (BLOCK_FRAGMENT_ORIGIN (block) == NULL_TREE);
4536 origin = block;
4538 if (prev_end)
4539 BLOCK_SAME_RANGE (prev_end) = 0;
4540 prev_end = NULL_TREE;
4542 /* If we have seen this block before, that means it now
4543 spans multiple address regions. Create a new fragment. */
4544 if (TREE_ASM_WRITTEN (block))
4546 tree new_block = copy_node (block);
4548 BLOCK_SAME_RANGE (new_block) = 0;
4549 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
4550 BLOCK_FRAGMENT_CHAIN (new_block)
4551 = BLOCK_FRAGMENT_CHAIN (origin);
4552 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
4554 NOTE_BLOCK (insn) = new_block;
4555 block = new_block;
4558 if (prev_beg == current_block && prev_beg)
4559 BLOCK_SAME_RANGE (block) = 1;
4561 prev_beg = origin;
4563 BLOCK_SUBBLOCKS (block) = 0;
4564 TREE_ASM_WRITTEN (block) = 1;
4565 /* When there's only one block for the entire function,
4566 current_block == block and we mustn't do this, it
4567 will cause infinite recursion. */
4568 if (block != current_block)
4570 tree super;
4571 if (block != origin)
4572 gcc_assert (BLOCK_SUPERCONTEXT (origin) == current_block
4573 || BLOCK_FRAGMENT_ORIGIN (BLOCK_SUPERCONTEXT
4574 (origin))
4575 == current_block);
4576 if (p_block_stack->is_empty ())
4577 super = current_block;
4578 else
4580 super = p_block_stack->last ();
4581 gcc_assert (super == current_block
4582 || BLOCK_FRAGMENT_ORIGIN (super)
4583 == current_block);
4585 BLOCK_SUPERCONTEXT (block) = super;
4586 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
4587 BLOCK_SUBBLOCKS (current_block) = block;
4588 current_block = origin;
4590 p_block_stack->safe_push (block);
4592 else if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_END)
4594 NOTE_BLOCK (insn) = p_block_stack->pop ();
4595 current_block = BLOCK_SUPERCONTEXT (current_block);
4596 if (BLOCK_FRAGMENT_ORIGIN (current_block))
4597 current_block = BLOCK_FRAGMENT_ORIGIN (current_block);
4598 prev_beg = NULL_TREE;
4599 prev_end = BLOCK_SAME_RANGE (NOTE_BLOCK (insn))
4600 ? NOTE_BLOCK (insn) : NULL_TREE;
4603 else
4605 prev_beg = NULL_TREE;
4606 if (prev_end)
4607 BLOCK_SAME_RANGE (prev_end) = 0;
4608 prev_end = NULL_TREE;
4613 /* Reverse the order of elements in the chain T of blocks,
4614 and return the new head of the chain (old last element). */
4616 tree
4617 blocks_nreverse (tree t)
4619 tree prev = 0, block, next;
4620 for (block = t; block; block = next)
4622 next = BLOCK_CHAIN (block);
4623 BLOCK_CHAIN (block) = prev;
4624 prev = block;
4626 return prev;
4629 /* Concatenate two chains of blocks (chained through BLOCK_CHAIN)
4630 by modifying the last node in chain 1 to point to chain 2. */
4632 tree
4633 block_chainon (tree op1, tree op2)
4635 tree t1;
4637 if (!op1)
4638 return op2;
4639 if (!op2)
4640 return op1;
4642 for (t1 = op1; BLOCK_CHAIN (t1); t1 = BLOCK_CHAIN (t1))
4643 continue;
4644 BLOCK_CHAIN (t1) = op2;
4646 #ifdef ENABLE_TREE_CHECKING
4648 tree t2;
4649 for (t2 = op2; t2; t2 = BLOCK_CHAIN (t2))
4650 gcc_assert (t2 != t1);
4652 #endif
4654 return op1;
4657 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
4658 non-NULL, list them all into VECTOR, in a depth-first preorder
4659 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
4660 blocks. */
4662 static int
4663 all_blocks (tree block, tree *vector)
4665 int n_blocks = 0;
4667 while (block)
4669 TREE_ASM_WRITTEN (block) = 0;
4671 /* Record this block. */
4672 if (vector)
4673 vector[n_blocks] = block;
4675 ++n_blocks;
4677 /* Record the subblocks, and their subblocks... */
4678 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
4679 vector ? vector + n_blocks : 0);
4680 block = BLOCK_CHAIN (block);
4683 return n_blocks;
4686 /* Return a vector containing all the blocks rooted at BLOCK. The
4687 number of elements in the vector is stored in N_BLOCKS_P. The
4688 vector is dynamically allocated; it is the caller's responsibility
4689 to call `free' on the pointer returned. */
4691 static tree *
4692 get_block_vector (tree block, int *n_blocks_p)
4694 tree *block_vector;
4696 *n_blocks_p = all_blocks (block, NULL);
4697 block_vector = XNEWVEC (tree, *n_blocks_p);
4698 all_blocks (block, block_vector);
4700 return block_vector;
4703 static GTY(()) int next_block_index = 2;
4705 /* Set BLOCK_NUMBER for all the blocks in FN. */
4707 void
4708 number_blocks (tree fn)
4710 int i;
4711 int n_blocks;
4712 tree *block_vector;
4714 /* For SDB and XCOFF debugging output, we start numbering the blocks
4715 from 1 within each function, rather than keeping a running
4716 count. */
4717 #if SDB_DEBUGGING_INFO || defined (XCOFF_DEBUGGING_INFO)
4718 if (write_symbols == SDB_DEBUG || write_symbols == XCOFF_DEBUG)
4719 next_block_index = 1;
4720 #endif
4722 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
4724 /* The top-level BLOCK isn't numbered at all. */
4725 for (i = 1; i < n_blocks; ++i)
4726 /* We number the blocks from two. */
4727 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
4729 free (block_vector);
4731 return;
4734 /* If VAR is present in a subblock of BLOCK, return the subblock. */
4736 DEBUG_FUNCTION tree
4737 debug_find_var_in_block_tree (tree var, tree block)
4739 tree t;
4741 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
4742 if (t == var)
4743 return block;
4745 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
4747 tree ret = debug_find_var_in_block_tree (var, t);
4748 if (ret)
4749 return ret;
4752 return NULL_TREE;
4755 /* Keep track of whether we're in a dummy function context. If we are,
4756 we don't want to invoke the set_current_function hook, because we'll
4757 get into trouble if the hook calls target_reinit () recursively or
4758 when the initial initialization is not yet complete. */
4760 static bool in_dummy_function;
4762 /* Invoke the target hook when setting cfun. Update the optimization options
4763 if the function uses different options than the default. */
4765 static void
4766 invoke_set_current_function_hook (tree fndecl)
4768 if (!in_dummy_function)
4770 tree opts = ((fndecl)
4771 ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (fndecl)
4772 : optimization_default_node);
4774 if (!opts)
4775 opts = optimization_default_node;
4777 /* Change optimization options if needed. */
4778 if (optimization_current_node != opts)
4780 optimization_current_node = opts;
4781 cl_optimization_restore (&global_options, TREE_OPTIMIZATION (opts));
4784 targetm.set_current_function (fndecl);
4785 this_fn_optabs = this_target_optabs;
4787 if (opts != optimization_default_node)
4789 init_tree_optimization_optabs (opts);
4790 if (TREE_OPTIMIZATION_OPTABS (opts))
4791 this_fn_optabs = (struct target_optabs *)
4792 TREE_OPTIMIZATION_OPTABS (opts);
4797 /* cfun should never be set directly; use this function. */
4799 void
4800 set_cfun (struct function *new_cfun)
4802 if (cfun != new_cfun)
4804 cfun = new_cfun;
4805 invoke_set_current_function_hook (new_cfun ? new_cfun->decl : NULL_TREE);
4806 redirect_edge_var_map_empty ();
4810 /* Initialized with NOGC, making this poisonous to the garbage collector. */
4812 static vec<function *> cfun_stack;
4814 /* Push the current cfun onto the stack, and set cfun to new_cfun. Also set
4815 current_function_decl accordingly. */
4817 void
4818 push_cfun (struct function *new_cfun)
4820 gcc_assert ((!cfun && !current_function_decl)
4821 || (cfun && current_function_decl == cfun->decl));
4822 cfun_stack.safe_push (cfun);
4823 current_function_decl = new_cfun ? new_cfun->decl : NULL_TREE;
4824 set_cfun (new_cfun);
4827 /* Pop cfun from the stack. Also set current_function_decl accordingly. */
4829 void
4830 pop_cfun (void)
4832 struct function *new_cfun = cfun_stack.pop ();
4833 /* When in_dummy_function, we do have a cfun but current_function_decl is
4834 NULL. We also allow pushing NULL cfun and subsequently changing
4835 current_function_decl to something else and have both restored by
4836 pop_cfun. */
4837 gcc_checking_assert (in_dummy_function
4838 || !cfun
4839 || current_function_decl == cfun->decl);
4840 set_cfun (new_cfun);
4841 current_function_decl = new_cfun ? new_cfun->decl : NULL_TREE;
4844 /* Return value of funcdef and increase it. */
4846 get_next_funcdef_no (void)
4848 return funcdef_no++;
4851 /* Return value of funcdef. */
4853 get_last_funcdef_no (void)
4855 return funcdef_no;
4858 /* Allocate a function structure for FNDECL and set its contents
4859 to the defaults. Set cfun to the newly-allocated object.
4860 Some of the helper functions invoked during initialization assume
4861 that cfun has already been set. Therefore, assign the new object
4862 directly into cfun and invoke the back end hook explicitly at the
4863 very end, rather than initializing a temporary and calling set_cfun
4864 on it.
4866 ABSTRACT_P is true if this is a function that will never be seen by
4867 the middle-end. Such functions are front-end concepts (like C++
4868 function templates) that do not correspond directly to functions
4869 placed in object files. */
4871 void
4872 allocate_struct_function (tree fndecl, bool abstract_p)
4874 tree fntype = fndecl ? TREE_TYPE (fndecl) : NULL_TREE;
4876 cfun = ggc_cleared_alloc<function> ();
4878 init_eh_for_function ();
4880 if (init_machine_status)
4881 cfun->machine = (*init_machine_status) ();
4883 #ifdef OVERRIDE_ABI_FORMAT
4884 OVERRIDE_ABI_FORMAT (fndecl);
4885 #endif
4887 if (fndecl != NULL_TREE)
4889 DECL_STRUCT_FUNCTION (fndecl) = cfun;
4890 cfun->decl = fndecl;
4891 current_function_funcdef_no = get_next_funcdef_no ();
4894 invoke_set_current_function_hook (fndecl);
4896 if (fndecl != NULL_TREE)
4898 tree result = DECL_RESULT (fndecl);
4900 if (!abstract_p)
4902 /* Now that we have activated any function-specific attributes
4903 that might affect layout, particularly vector modes, relayout
4904 each of the parameters and the result. */
4905 relayout_decl (result);
4906 for (tree parm = DECL_ARGUMENTS (fndecl); parm;
4907 parm = DECL_CHAIN (parm))
4908 relayout_decl (parm);
4910 /* Similarly relayout the function decl. */
4911 targetm.target_option.relayout_function (fndecl);
4914 if (!abstract_p && aggregate_value_p (result, fndecl))
4916 #ifdef PCC_STATIC_STRUCT_RETURN
4917 cfun->returns_pcc_struct = 1;
4918 #endif
4919 cfun->returns_struct = 1;
4922 cfun->stdarg = stdarg_p (fntype);
4924 /* Assume all registers in stdarg functions need to be saved. */
4925 cfun->va_list_gpr_size = VA_LIST_MAX_GPR_SIZE;
4926 cfun->va_list_fpr_size = VA_LIST_MAX_FPR_SIZE;
4928 /* ??? This could be set on a per-function basis by the front-end
4929 but is this worth the hassle? */
4930 cfun->can_throw_non_call_exceptions = flag_non_call_exceptions;
4931 cfun->can_delete_dead_exceptions = flag_delete_dead_exceptions;
4933 if (!profile_flag && !flag_instrument_function_entry_exit)
4934 DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl) = 1;
4938 /* This is like allocate_struct_function, but pushes a new cfun for FNDECL
4939 instead of just setting it. */
4941 void
4942 push_struct_function (tree fndecl)
4944 /* When in_dummy_function we might be in the middle of a pop_cfun and
4945 current_function_decl and cfun may not match. */
4946 gcc_assert (in_dummy_function
4947 || (!cfun && !current_function_decl)
4948 || (cfun && current_function_decl == cfun->decl));
4949 cfun_stack.safe_push (cfun);
4950 current_function_decl = fndecl;
4951 allocate_struct_function (fndecl, false);
4954 /* Reset crtl and other non-struct-function variables to defaults as
4955 appropriate for emitting rtl at the start of a function. */
4957 static void
4958 prepare_function_start (void)
4960 gcc_assert (!get_last_insn ());
4961 init_temp_slots ();
4962 init_emit ();
4963 init_varasm_status ();
4964 init_expr ();
4965 default_rtl_profile ();
4967 if (flag_stack_usage_info)
4969 cfun->su = ggc_cleared_alloc<stack_usage> ();
4970 cfun->su->static_stack_size = -1;
4973 cse_not_expected = ! optimize;
4975 /* Caller save not needed yet. */
4976 caller_save_needed = 0;
4978 /* We haven't done register allocation yet. */
4979 reg_renumber = 0;
4981 /* Indicate that we have not instantiated virtual registers yet. */
4982 virtuals_instantiated = 0;
4984 /* Indicate that we want CONCATs now. */
4985 generating_concat_p = 1;
4987 /* Indicate we have no need of a frame pointer yet. */
4988 frame_pointer_needed = 0;
4991 void
4992 push_dummy_function (bool with_decl)
4994 tree fn_decl, fn_type, fn_result_decl;
4996 gcc_assert (!in_dummy_function);
4997 in_dummy_function = true;
4999 if (with_decl)
5001 fn_type = build_function_type_list (void_type_node, NULL_TREE);
5002 fn_decl = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL, NULL_TREE,
5003 fn_type);
5004 fn_result_decl = build_decl (UNKNOWN_LOCATION, RESULT_DECL,
5005 NULL_TREE, void_type_node);
5006 DECL_RESULT (fn_decl) = fn_result_decl;
5008 else
5009 fn_decl = NULL_TREE;
5011 push_struct_function (fn_decl);
5014 /* Initialize the rtl expansion mechanism so that we can do simple things
5015 like generate sequences. This is used to provide a context during global
5016 initialization of some passes. You must call expand_dummy_function_end
5017 to exit this context. */
5019 void
5020 init_dummy_function_start (void)
5022 push_dummy_function (false);
5023 prepare_function_start ();
5026 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
5027 and initialize static variables for generating RTL for the statements
5028 of the function. */
5030 void
5031 init_function_start (tree subr)
5033 /* Initialize backend, if needed. */
5034 initialize_rtl ();
5036 prepare_function_start ();
5037 decide_function_section (subr);
5039 /* Warn if this value is an aggregate type,
5040 regardless of which calling convention we are using for it. */
5041 if (AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
5042 warning (OPT_Waggregate_return, "function returns an aggregate");
5045 /* Expand code to verify the stack_protect_guard. This is invoked at
5046 the end of a function to be protected. */
5048 void
5049 stack_protect_epilogue (void)
5051 tree guard_decl = targetm.stack_protect_guard ();
5052 rtx_code_label *label = gen_label_rtx ();
5053 rtx x, y;
5054 rtx_insn *seq;
5056 x = expand_normal (crtl->stack_protect_guard);
5057 y = expand_normal (guard_decl);
5059 /* Allow the target to compare Y with X without leaking either into
5060 a register. */
5061 if (targetm.have_stack_protect_test ()
5062 && ((seq = targetm.gen_stack_protect_test (x, y, label)) != NULL_RTX))
5063 emit_insn (seq);
5064 else
5065 emit_cmp_and_jump_insns (x, y, EQ, NULL_RTX, ptr_mode, 1, label);
5067 /* The noreturn predictor has been moved to the tree level. The rtl-level
5068 predictors estimate this branch about 20%, which isn't enough to get
5069 things moved out of line. Since this is the only extant case of adding
5070 a noreturn function at the rtl level, it doesn't seem worth doing ought
5071 except adding the prediction by hand. */
5072 rtx_insn *tmp = get_last_insn ();
5073 if (JUMP_P (tmp))
5074 predict_insn_def (tmp, PRED_NORETURN, TAKEN);
5076 expand_call (targetm.stack_protect_fail (), NULL_RTX, /*ignore=*/true);
5077 free_temp_slots ();
5078 emit_label (label);
5081 /* Start the RTL for a new function, and set variables used for
5082 emitting RTL.
5083 SUBR is the FUNCTION_DECL node.
5084 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
5085 the function's parameters, which must be run at any return statement. */
5087 void
5088 expand_function_start (tree subr)
5090 /* Make sure volatile mem refs aren't considered
5091 valid operands of arithmetic insns. */
5092 init_recog_no_volatile ();
5094 crtl->profile
5095 = (profile_flag
5096 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
5098 crtl->limit_stack
5099 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
5101 /* Make the label for return statements to jump to. Do not special
5102 case machines with special return instructions -- they will be
5103 handled later during jump, ifcvt, or epilogue creation. */
5104 return_label = gen_label_rtx ();
5106 /* Initialize rtx used to return the value. */
5107 /* Do this before assign_parms so that we copy the struct value address
5108 before any library calls that assign parms might generate. */
5110 /* Decide whether to return the value in memory or in a register. */
5111 tree res = DECL_RESULT (subr);
5112 if (aggregate_value_p (res, subr))
5114 /* Returning something that won't go in a register. */
5115 rtx value_address = 0;
5117 #ifdef PCC_STATIC_STRUCT_RETURN
5118 if (cfun->returns_pcc_struct)
5120 int size = int_size_in_bytes (TREE_TYPE (res));
5121 value_address = assemble_static_space (size);
5123 else
5124 #endif
5126 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 2);
5127 /* Expect to be passed the address of a place to store the value.
5128 If it is passed as an argument, assign_parms will take care of
5129 it. */
5130 if (sv)
5132 value_address = gen_reg_rtx (Pmode);
5133 emit_move_insn (value_address, sv);
5136 if (value_address)
5138 rtx x = value_address;
5139 if (!DECL_BY_REFERENCE (res))
5141 x = gen_rtx_MEM (DECL_MODE (res), x);
5142 set_mem_attributes (x, res, 1);
5144 set_parm_rtl (res, x);
5147 else if (DECL_MODE (res) == VOIDmode)
5148 /* If return mode is void, this decl rtl should not be used. */
5149 set_parm_rtl (res, NULL_RTX);
5150 else
5152 /* Compute the return values into a pseudo reg, which we will copy
5153 into the true return register after the cleanups are done. */
5154 tree return_type = TREE_TYPE (res);
5156 /* If we may coalesce this result, make sure it has the expected mode
5157 in case it was promoted. But we need not bother about BLKmode. */
5158 machine_mode promoted_mode
5159 = flag_tree_coalesce_vars && is_gimple_reg (res)
5160 ? promote_ssa_mode (ssa_default_def (cfun, res), NULL)
5161 : BLKmode;
5163 if (promoted_mode != BLKmode)
5164 set_parm_rtl (res, gen_reg_rtx (promoted_mode));
5165 else if (TYPE_MODE (return_type) != BLKmode
5166 && targetm.calls.return_in_msb (return_type))
5167 /* expand_function_end will insert the appropriate padding in
5168 this case. Use the return value's natural (unpadded) mode
5169 within the function proper. */
5170 set_parm_rtl (res, gen_reg_rtx (TYPE_MODE (return_type)));
5171 else
5173 /* In order to figure out what mode to use for the pseudo, we
5174 figure out what the mode of the eventual return register will
5175 actually be, and use that. */
5176 rtx hard_reg = hard_function_value (return_type, subr, 0, 1);
5178 /* Structures that are returned in registers are not
5179 aggregate_value_p, so we may see a PARALLEL or a REG. */
5180 if (REG_P (hard_reg))
5181 set_parm_rtl (res, gen_reg_rtx (GET_MODE (hard_reg)));
5182 else
5184 gcc_assert (GET_CODE (hard_reg) == PARALLEL);
5185 set_parm_rtl (res, gen_group_rtx (hard_reg));
5189 /* Set DECL_REGISTER flag so that expand_function_end will copy the
5190 result to the real return register(s). */
5191 DECL_REGISTER (res) = 1;
5193 if (chkp_function_instrumented_p (current_function_decl))
5195 tree return_type = TREE_TYPE (res);
5196 rtx bounds = targetm.calls.chkp_function_value_bounds (return_type,
5197 subr, 1);
5198 SET_DECL_BOUNDS_RTL (res, bounds);
5202 /* Initialize rtx for parameters and local variables.
5203 In some cases this requires emitting insns. */
5204 assign_parms (subr);
5206 /* If function gets a static chain arg, store it. */
5207 if (cfun->static_chain_decl)
5209 tree parm = cfun->static_chain_decl;
5210 rtx local, chain;
5211 rtx_insn *insn;
5212 int unsignedp;
5214 local = gen_reg_rtx (promote_decl_mode (parm, &unsignedp));
5215 chain = targetm.calls.static_chain (current_function_decl, true);
5217 set_decl_incoming_rtl (parm, chain, false);
5218 set_parm_rtl (parm, local);
5219 mark_reg_pointer (local, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
5221 if (GET_MODE (local) != GET_MODE (chain))
5223 convert_move (local, chain, unsignedp);
5224 insn = get_last_insn ();
5226 else
5227 insn = emit_move_insn (local, chain);
5229 /* Mark the register as eliminable, similar to parameters. */
5230 if (MEM_P (chain)
5231 && reg_mentioned_p (arg_pointer_rtx, XEXP (chain, 0)))
5232 set_dst_reg_note (insn, REG_EQUIV, chain, local);
5234 /* If we aren't optimizing, save the static chain onto the stack. */
5235 if (!optimize)
5237 tree saved_static_chain_decl
5238 = build_decl (DECL_SOURCE_LOCATION (parm), VAR_DECL,
5239 DECL_NAME (parm), TREE_TYPE (parm));
5240 rtx saved_static_chain_rtx
5241 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
5242 SET_DECL_RTL (saved_static_chain_decl, saved_static_chain_rtx);
5243 emit_move_insn (saved_static_chain_rtx, chain);
5244 SET_DECL_VALUE_EXPR (parm, saved_static_chain_decl);
5245 DECL_HAS_VALUE_EXPR_P (parm) = 1;
5249 /* If the function receives a non-local goto, then store the
5250 bits we need to restore the frame pointer. */
5251 if (cfun->nonlocal_goto_save_area)
5253 tree t_save;
5254 rtx r_save;
5256 tree var = TREE_OPERAND (cfun->nonlocal_goto_save_area, 0);
5257 gcc_assert (DECL_RTL_SET_P (var));
5259 t_save = build4 (ARRAY_REF,
5260 TREE_TYPE (TREE_TYPE (cfun->nonlocal_goto_save_area)),
5261 cfun->nonlocal_goto_save_area,
5262 integer_zero_node, NULL_TREE, NULL_TREE);
5263 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
5264 gcc_assert (GET_MODE (r_save) == Pmode);
5266 emit_move_insn (r_save, targetm.builtin_setjmp_frame_value ());
5267 update_nonlocal_goto_save_area ();
5270 /* The following was moved from init_function_start.
5271 The move is supposed to make sdb output more accurate. */
5272 /* Indicate the beginning of the function body,
5273 as opposed to parm setup. */
5274 emit_note (NOTE_INSN_FUNCTION_BEG);
5276 gcc_assert (NOTE_P (get_last_insn ()));
5278 parm_birth_insn = get_last_insn ();
5280 if (crtl->profile)
5282 #ifdef PROFILE_HOOK
5283 PROFILE_HOOK (current_function_funcdef_no);
5284 #endif
5287 /* If we are doing generic stack checking, the probe should go here. */
5288 if (flag_stack_check == GENERIC_STACK_CHECK)
5289 stack_check_probe_note = emit_note (NOTE_INSN_DELETED);
5292 void
5293 pop_dummy_function (void)
5295 pop_cfun ();
5296 in_dummy_function = false;
5299 /* Undo the effects of init_dummy_function_start. */
5300 void
5301 expand_dummy_function_end (void)
5303 gcc_assert (in_dummy_function);
5305 /* End any sequences that failed to be closed due to syntax errors. */
5306 while (in_sequence_p ())
5307 end_sequence ();
5309 /* Outside function body, can't compute type's actual size
5310 until next function's body starts. */
5312 free_after_parsing (cfun);
5313 free_after_compilation (cfun);
5314 pop_dummy_function ();
5317 /* Helper for diddle_return_value. */
5319 void
5320 diddle_return_value_1 (void (*doit) (rtx, void *), void *arg, rtx outgoing)
5322 if (! outgoing)
5323 return;
5325 if (REG_P (outgoing))
5326 (*doit) (outgoing, arg);
5327 else if (GET_CODE (outgoing) == PARALLEL)
5329 int i;
5331 for (i = 0; i < XVECLEN (outgoing, 0); i++)
5333 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
5335 if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
5336 (*doit) (x, arg);
5341 /* Call DOIT for each hard register used as a return value from
5342 the current function. */
5344 void
5345 diddle_return_value (void (*doit) (rtx, void *), void *arg)
5347 diddle_return_value_1 (doit, arg, crtl->return_bnd);
5348 diddle_return_value_1 (doit, arg, crtl->return_rtx);
5351 static void
5352 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
5354 emit_clobber (reg);
5357 void
5358 clobber_return_register (void)
5360 diddle_return_value (do_clobber_return_reg, NULL);
5362 /* In case we do use pseudo to return value, clobber it too. */
5363 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
5365 tree decl_result = DECL_RESULT (current_function_decl);
5366 rtx decl_rtl = DECL_RTL (decl_result);
5367 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
5369 do_clobber_return_reg (decl_rtl, NULL);
5374 static void
5375 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
5377 emit_use (reg);
5380 static void
5381 use_return_register (void)
5383 diddle_return_value (do_use_return_reg, NULL);
5386 /* Set the location of the insn chain starting at INSN to LOC. */
5388 static void
5389 set_insn_locations (rtx_insn *insn, int loc)
5391 while (insn != NULL)
5393 if (INSN_P (insn))
5394 INSN_LOCATION (insn) = loc;
5395 insn = NEXT_INSN (insn);
5399 /* Generate RTL for the end of the current function. */
5401 void
5402 expand_function_end (void)
5404 /* If arg_pointer_save_area was referenced only from a nested
5405 function, we will not have initialized it yet. Do that now. */
5406 if (arg_pointer_save_area && ! crtl->arg_pointer_save_area_init)
5407 get_arg_pointer_save_area ();
5409 /* If we are doing generic stack checking and this function makes calls,
5410 do a stack probe at the start of the function to ensure we have enough
5411 space for another stack frame. */
5412 if (flag_stack_check == GENERIC_STACK_CHECK)
5414 rtx_insn *insn, *seq;
5416 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
5417 if (CALL_P (insn))
5419 rtx max_frame_size = GEN_INT (STACK_CHECK_MAX_FRAME_SIZE);
5420 start_sequence ();
5421 if (STACK_CHECK_MOVING_SP)
5422 anti_adjust_stack_and_probe (max_frame_size, true);
5423 else
5424 probe_stack_range (STACK_OLD_CHECK_PROTECT, max_frame_size);
5425 seq = get_insns ();
5426 end_sequence ();
5427 set_insn_locations (seq, prologue_location);
5428 emit_insn_before (seq, stack_check_probe_note);
5429 break;
5433 /* End any sequences that failed to be closed due to syntax errors. */
5434 while (in_sequence_p ())
5435 end_sequence ();
5437 clear_pending_stack_adjust ();
5438 do_pending_stack_adjust ();
5440 /* Output a linenumber for the end of the function.
5441 SDB depends on this. */
5442 set_curr_insn_location (input_location);
5444 /* Before the return label (if any), clobber the return
5445 registers so that they are not propagated live to the rest of
5446 the function. This can only happen with functions that drop
5447 through; if there had been a return statement, there would
5448 have either been a return rtx, or a jump to the return label.
5450 We delay actual code generation after the current_function_value_rtx
5451 is computed. */
5452 rtx_insn *clobber_after = get_last_insn ();
5454 /* Output the label for the actual return from the function. */
5455 emit_label (return_label);
5457 if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ)
5459 /* Let except.c know where it should emit the call to unregister
5460 the function context for sjlj exceptions. */
5461 if (flag_exceptions)
5462 sjlj_emit_function_exit_after (get_last_insn ());
5464 else
5466 /* We want to ensure that instructions that may trap are not
5467 moved into the epilogue by scheduling, because we don't
5468 always emit unwind information for the epilogue. */
5469 if (cfun->can_throw_non_call_exceptions)
5470 emit_insn (gen_blockage ());
5473 /* If this is an implementation of throw, do what's necessary to
5474 communicate between __builtin_eh_return and the epilogue. */
5475 expand_eh_return ();
5477 /* If scalar return value was computed in a pseudo-reg, or was a named
5478 return value that got dumped to the stack, copy that to the hard
5479 return register. */
5480 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
5482 tree decl_result = DECL_RESULT (current_function_decl);
5483 rtx decl_rtl = DECL_RTL (decl_result);
5485 if (REG_P (decl_rtl)
5486 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
5487 : DECL_REGISTER (decl_result))
5489 rtx real_decl_rtl = crtl->return_rtx;
5491 /* This should be set in assign_parms. */
5492 gcc_assert (REG_FUNCTION_VALUE_P (real_decl_rtl));
5494 /* If this is a BLKmode structure being returned in registers,
5495 then use the mode computed in expand_return. Note that if
5496 decl_rtl is memory, then its mode may have been changed,
5497 but that crtl->return_rtx has not. */
5498 if (GET_MODE (real_decl_rtl) == BLKmode)
5499 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
5501 /* If a non-BLKmode return value should be padded at the least
5502 significant end of the register, shift it left by the appropriate
5503 amount. BLKmode results are handled using the group load/store
5504 machinery. */
5505 if (TYPE_MODE (TREE_TYPE (decl_result)) != BLKmode
5506 && REG_P (real_decl_rtl)
5507 && targetm.calls.return_in_msb (TREE_TYPE (decl_result)))
5509 emit_move_insn (gen_rtx_REG (GET_MODE (decl_rtl),
5510 REGNO (real_decl_rtl)),
5511 decl_rtl);
5512 shift_return_value (GET_MODE (decl_rtl), true, real_decl_rtl);
5514 else if (GET_CODE (real_decl_rtl) == PARALLEL)
5516 /* If expand_function_start has created a PARALLEL for decl_rtl,
5517 move the result to the real return registers. Otherwise, do
5518 a group load from decl_rtl for a named return. */
5519 if (GET_CODE (decl_rtl) == PARALLEL)
5520 emit_group_move (real_decl_rtl, decl_rtl);
5521 else
5522 emit_group_load (real_decl_rtl, decl_rtl,
5523 TREE_TYPE (decl_result),
5524 int_size_in_bytes (TREE_TYPE (decl_result)));
5526 /* In the case of complex integer modes smaller than a word, we'll
5527 need to generate some non-trivial bitfield insertions. Do that
5528 on a pseudo and not the hard register. */
5529 else if (GET_CODE (decl_rtl) == CONCAT
5530 && GET_MODE_CLASS (GET_MODE (decl_rtl)) == MODE_COMPLEX_INT
5531 && GET_MODE_BITSIZE (GET_MODE (decl_rtl)) <= BITS_PER_WORD)
5533 int old_generating_concat_p;
5534 rtx tmp;
5536 old_generating_concat_p = generating_concat_p;
5537 generating_concat_p = 0;
5538 tmp = gen_reg_rtx (GET_MODE (decl_rtl));
5539 generating_concat_p = old_generating_concat_p;
5541 emit_move_insn (tmp, decl_rtl);
5542 emit_move_insn (real_decl_rtl, tmp);
5544 /* If a named return value dumped decl_return to memory, then
5545 we may need to re-do the PROMOTE_MODE signed/unsigned
5546 extension. */
5547 else if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
5549 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
5550 promote_function_mode (TREE_TYPE (decl_result),
5551 GET_MODE (decl_rtl), &unsignedp,
5552 TREE_TYPE (current_function_decl), 1);
5554 convert_move (real_decl_rtl, decl_rtl, unsignedp);
5556 else
5557 emit_move_insn (real_decl_rtl, decl_rtl);
5561 /* If returning a structure, arrange to return the address of the value
5562 in a place where debuggers expect to find it.
5564 If returning a structure PCC style,
5565 the caller also depends on this value.
5566 And cfun->returns_pcc_struct is not necessarily set. */
5567 if ((cfun->returns_struct || cfun->returns_pcc_struct)
5568 && !targetm.calls.omit_struct_return_reg)
5570 rtx value_address = DECL_RTL (DECL_RESULT (current_function_decl));
5571 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
5572 rtx outgoing;
5574 if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
5575 type = TREE_TYPE (type);
5576 else
5577 value_address = XEXP (value_address, 0);
5579 outgoing = targetm.calls.function_value (build_pointer_type (type),
5580 current_function_decl, true);
5582 /* Mark this as a function return value so integrate will delete the
5583 assignment and USE below when inlining this function. */
5584 REG_FUNCTION_VALUE_P (outgoing) = 1;
5586 /* The address may be ptr_mode and OUTGOING may be Pmode. */
5587 value_address = convert_memory_address (GET_MODE (outgoing),
5588 value_address);
5590 emit_move_insn (outgoing, value_address);
5592 /* Show return register used to hold result (in this case the address
5593 of the result. */
5594 crtl->return_rtx = outgoing;
5597 /* Emit the actual code to clobber return register. Don't emit
5598 it if clobber_after is a barrier, then the previous basic block
5599 certainly doesn't fall thru into the exit block. */
5600 if (!BARRIER_P (clobber_after))
5602 start_sequence ();
5603 clobber_return_register ();
5604 rtx_insn *seq = get_insns ();
5605 end_sequence ();
5607 emit_insn_after (seq, clobber_after);
5610 /* Output the label for the naked return from the function. */
5611 if (naked_return_label)
5612 emit_label (naked_return_label);
5614 /* @@@ This is a kludge. We want to ensure that instructions that
5615 may trap are not moved into the epilogue by scheduling, because
5616 we don't always emit unwind information for the epilogue. */
5617 if (cfun->can_throw_non_call_exceptions
5618 && targetm_common.except_unwind_info (&global_options) != UI_SJLJ)
5619 emit_insn (gen_blockage ());
5621 /* If stack protection is enabled for this function, check the guard. */
5622 if (crtl->stack_protect_guard)
5623 stack_protect_epilogue ();
5625 /* If we had calls to alloca, and this machine needs
5626 an accurate stack pointer to exit the function,
5627 insert some code to save and restore the stack pointer. */
5628 if (! EXIT_IGNORE_STACK
5629 && cfun->calls_alloca)
5631 rtx tem = 0;
5633 start_sequence ();
5634 emit_stack_save (SAVE_FUNCTION, &tem);
5635 rtx_insn *seq = get_insns ();
5636 end_sequence ();
5637 emit_insn_before (seq, parm_birth_insn);
5639 emit_stack_restore (SAVE_FUNCTION, tem);
5642 /* ??? This should no longer be necessary since stupid is no longer with
5643 us, but there are some parts of the compiler (eg reload_combine, and
5644 sh mach_dep_reorg) that still try and compute their own lifetime info
5645 instead of using the general framework. */
5646 use_return_register ();
5650 get_arg_pointer_save_area (void)
5652 rtx ret = arg_pointer_save_area;
5654 if (! ret)
5656 ret = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
5657 arg_pointer_save_area = ret;
5660 if (! crtl->arg_pointer_save_area_init)
5662 /* Save the arg pointer at the beginning of the function. The
5663 generated stack slot may not be a valid memory address, so we
5664 have to check it and fix it if necessary. */
5665 start_sequence ();
5666 emit_move_insn (validize_mem (copy_rtx (ret)),
5667 crtl->args.internal_arg_pointer);
5668 rtx_insn *seq = get_insns ();
5669 end_sequence ();
5671 push_topmost_sequence ();
5672 emit_insn_after (seq, entry_of_function ());
5673 pop_topmost_sequence ();
5675 crtl->arg_pointer_save_area_init = true;
5678 return ret;
5681 /* Add a list of INSNS to the hash HASHP, possibly allocating HASHP
5682 for the first time. */
5684 static void
5685 record_insns (rtx_insn *insns, rtx end, hash_table<insn_cache_hasher> **hashp)
5687 rtx_insn *tmp;
5688 hash_table<insn_cache_hasher> *hash = *hashp;
5690 if (hash == NULL)
5691 *hashp = hash = hash_table<insn_cache_hasher>::create_ggc (17);
5693 for (tmp = insns; tmp != end; tmp = NEXT_INSN (tmp))
5695 rtx *slot = hash->find_slot (tmp, INSERT);
5696 gcc_assert (*slot == NULL);
5697 *slot = tmp;
5701 /* INSN has been duplicated or replaced by as COPY, perhaps by duplicating a
5702 basic block, splitting or peepholes. If INSN is a prologue or epilogue
5703 insn, then record COPY as well. */
5705 void
5706 maybe_copy_prologue_epilogue_insn (rtx insn, rtx copy)
5708 hash_table<insn_cache_hasher> *hash;
5709 rtx *slot;
5711 hash = epilogue_insn_hash;
5712 if (!hash || !hash->find (insn))
5714 hash = prologue_insn_hash;
5715 if (!hash || !hash->find (insn))
5716 return;
5719 slot = hash->find_slot (copy, INSERT);
5720 gcc_assert (*slot == NULL);
5721 *slot = copy;
5724 /* Determine if any INSNs in HASH are, or are part of, INSN. Because
5725 we can be running after reorg, SEQUENCE rtl is possible. */
5727 static bool
5728 contains (const_rtx insn, hash_table<insn_cache_hasher> *hash)
5730 if (hash == NULL)
5731 return false;
5733 if (NONJUMP_INSN_P (insn) && GET_CODE (PATTERN (insn)) == SEQUENCE)
5735 rtx_sequence *seq = as_a <rtx_sequence *> (PATTERN (insn));
5736 int i;
5737 for (i = seq->len () - 1; i >= 0; i--)
5738 if (hash->find (seq->element (i)))
5739 return true;
5740 return false;
5743 return hash->find (const_cast<rtx> (insn)) != NULL;
5747 prologue_epilogue_contains (const_rtx insn)
5749 if (contains (insn, prologue_insn_hash))
5750 return 1;
5751 if (contains (insn, epilogue_insn_hash))
5752 return 1;
5753 return 0;
5756 /* Insert use of return register before the end of BB. */
5758 static void
5759 emit_use_return_register_into_block (basic_block bb)
5761 start_sequence ();
5762 use_return_register ();
5763 rtx_insn *seq = get_insns ();
5764 end_sequence ();
5765 rtx_insn *insn = BB_END (bb);
5766 if (HAVE_cc0 && reg_mentioned_p (cc0_rtx, PATTERN (insn)))
5767 insn = prev_cc0_setter (insn);
5769 emit_insn_before (seq, insn);
5773 /* Create a return pattern, either simple_return or return, depending on
5774 simple_p. */
5776 static rtx_insn *
5777 gen_return_pattern (bool simple_p)
5779 return (simple_p
5780 ? targetm.gen_simple_return ()
5781 : targetm.gen_return ());
5784 /* Insert an appropriate return pattern at the end of block BB. This
5785 also means updating block_for_insn appropriately. SIMPLE_P is
5786 the same as in gen_return_pattern and passed to it. */
5788 void
5789 emit_return_into_block (bool simple_p, basic_block bb)
5791 rtx_jump_insn *jump = emit_jump_insn_after (gen_return_pattern (simple_p),
5792 BB_END (bb));
5793 rtx pat = PATTERN (jump);
5794 if (GET_CODE (pat) == PARALLEL)
5795 pat = XVECEXP (pat, 0, 0);
5796 gcc_assert (ANY_RETURN_P (pat));
5797 JUMP_LABEL (jump) = pat;
5800 /* Set JUMP_LABEL for a return insn. */
5802 void
5803 set_return_jump_label (rtx_insn *returnjump)
5805 rtx pat = PATTERN (returnjump);
5806 if (GET_CODE (pat) == PARALLEL)
5807 pat = XVECEXP (pat, 0, 0);
5808 if (ANY_RETURN_P (pat))
5809 JUMP_LABEL (returnjump) = pat;
5810 else
5811 JUMP_LABEL (returnjump) = ret_rtx;
5814 /* Return true if there are any active insns between HEAD and TAIL. */
5815 bool
5816 active_insn_between (rtx_insn *head, rtx_insn *tail)
5818 while (tail)
5820 if (active_insn_p (tail))
5821 return true;
5822 if (tail == head)
5823 return false;
5824 tail = PREV_INSN (tail);
5826 return false;
5829 /* LAST_BB is a block that exits, and empty of active instructions.
5830 Examine its predecessors for jumps that can be converted to
5831 (conditional) returns. */
5832 vec<edge>
5833 convert_jumps_to_returns (basic_block last_bb, bool simple_p,
5834 vec<edge> unconverted ATTRIBUTE_UNUSED)
5836 int i;
5837 basic_block bb;
5838 edge_iterator ei;
5839 edge e;
5840 auto_vec<basic_block> src_bbs (EDGE_COUNT (last_bb->preds));
5842 FOR_EACH_EDGE (e, ei, last_bb->preds)
5843 if (e->src != ENTRY_BLOCK_PTR_FOR_FN (cfun))
5844 src_bbs.quick_push (e->src);
5846 rtx_insn *label = BB_HEAD (last_bb);
5848 FOR_EACH_VEC_ELT (src_bbs, i, bb)
5850 rtx_insn *jump = BB_END (bb);
5852 if (!JUMP_P (jump) || JUMP_LABEL (jump) != label)
5853 continue;
5855 e = find_edge (bb, last_bb);
5857 /* If we have an unconditional jump, we can replace that
5858 with a simple return instruction. */
5859 if (simplejump_p (jump))
5861 /* The use of the return register might be present in the exit
5862 fallthru block. Either:
5863 - removing the use is safe, and we should remove the use in
5864 the exit fallthru block, or
5865 - removing the use is not safe, and we should add it here.
5866 For now, we conservatively choose the latter. Either of the
5867 2 helps in crossjumping. */
5868 emit_use_return_register_into_block (bb);
5870 emit_return_into_block (simple_p, bb);
5871 delete_insn (jump);
5874 /* If we have a conditional jump branching to the last
5875 block, we can try to replace that with a conditional
5876 return instruction. */
5877 else if (condjump_p (jump))
5879 rtx dest;
5881 if (simple_p)
5882 dest = simple_return_rtx;
5883 else
5884 dest = ret_rtx;
5885 if (!redirect_jump (as_a <rtx_jump_insn *> (jump), dest, 0))
5887 if (targetm.have_simple_return () && simple_p)
5889 if (dump_file)
5890 fprintf (dump_file,
5891 "Failed to redirect bb %d branch.\n", bb->index);
5892 unconverted.safe_push (e);
5894 continue;
5897 /* See comment in simplejump_p case above. */
5898 emit_use_return_register_into_block (bb);
5900 /* If this block has only one successor, it both jumps
5901 and falls through to the fallthru block, so we can't
5902 delete the edge. */
5903 if (single_succ_p (bb))
5904 continue;
5906 else
5908 if (targetm.have_simple_return () && simple_p)
5910 if (dump_file)
5911 fprintf (dump_file,
5912 "Failed to redirect bb %d branch.\n", bb->index);
5913 unconverted.safe_push (e);
5915 continue;
5918 /* Fix up the CFG for the successful change we just made. */
5919 redirect_edge_succ (e, EXIT_BLOCK_PTR_FOR_FN (cfun));
5920 e->flags &= ~EDGE_CROSSING;
5922 src_bbs.release ();
5923 return unconverted;
5926 /* Emit a return insn for the exit fallthru block. */
5927 basic_block
5928 emit_return_for_exit (edge exit_fallthru_edge, bool simple_p)
5930 basic_block last_bb = exit_fallthru_edge->src;
5932 if (JUMP_P (BB_END (last_bb)))
5934 last_bb = split_edge (exit_fallthru_edge);
5935 exit_fallthru_edge = single_succ_edge (last_bb);
5937 emit_barrier_after (BB_END (last_bb));
5938 emit_return_into_block (simple_p, last_bb);
5939 exit_fallthru_edge->flags &= ~EDGE_FALLTHRU;
5940 return last_bb;
5944 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
5945 this into place with notes indicating where the prologue ends and where
5946 the epilogue begins. Update the basic block information when possible.
5948 Notes on epilogue placement:
5949 There are several kinds of edges to the exit block:
5950 * a single fallthru edge from LAST_BB
5951 * possibly, edges from blocks containing sibcalls
5952 * possibly, fake edges from infinite loops
5954 The epilogue is always emitted on the fallthru edge from the last basic
5955 block in the function, LAST_BB, into the exit block.
5957 If LAST_BB is empty except for a label, it is the target of every
5958 other basic block in the function that ends in a return. If a
5959 target has a return or simple_return pattern (possibly with
5960 conditional variants), these basic blocks can be changed so that a
5961 return insn is emitted into them, and their target is adjusted to
5962 the real exit block.
5964 Notes on shrink wrapping: We implement a fairly conservative
5965 version of shrink-wrapping rather than the textbook one. We only
5966 generate a single prologue and a single epilogue. This is
5967 sufficient to catch a number of interesting cases involving early
5968 exits.
5970 First, we identify the blocks that require the prologue to occur before
5971 them. These are the ones that modify a call-saved register, or reference
5972 any of the stack or frame pointer registers. To simplify things, we then
5973 mark everything reachable from these blocks as also requiring a prologue.
5974 This takes care of loops automatically, and avoids the need to examine
5975 whether MEMs reference the frame, since it is sufficient to check for
5976 occurrences of the stack or frame pointer.
5978 We then compute the set of blocks for which the need for a prologue
5979 is anticipatable (borrowing terminology from the shrink-wrapping
5980 description in Muchnick's book). These are the blocks which either
5981 require a prologue themselves, or those that have only successors
5982 where the prologue is anticipatable. The prologue needs to be
5983 inserted on all edges from BB1->BB2 where BB2 is in ANTIC and BB1
5984 is not. For the moment, we ensure that only one such edge exists.
5986 The epilogue is placed as described above, but we make a
5987 distinction between inserting return and simple_return patterns
5988 when modifying other blocks that end in a return. Blocks that end
5989 in a sibcall omit the sibcall_epilogue if the block is not in
5990 ANTIC. */
5992 void
5993 thread_prologue_and_epilogue_insns (void)
5995 bool inserted;
5996 vec<edge> unconverted_simple_returns = vNULL;
5997 bitmap_head bb_flags;
5998 rtx_insn *returnjump;
5999 rtx_insn *epilogue_end ATTRIBUTE_UNUSED;
6000 rtx_insn *prologue_seq ATTRIBUTE_UNUSED, *split_prologue_seq ATTRIBUTE_UNUSED;
6001 edge e, entry_edge, orig_entry_edge, exit_fallthru_edge;
6002 edge_iterator ei;
6004 df_analyze ();
6006 rtl_profile_for_bb (ENTRY_BLOCK_PTR_FOR_FN (cfun));
6008 inserted = false;
6009 epilogue_end = NULL;
6010 returnjump = NULL;
6012 /* Can't deal with multiple successors of the entry block at the
6013 moment. Function should always have at least one entry
6014 point. */
6015 gcc_assert (single_succ_p (ENTRY_BLOCK_PTR_FOR_FN (cfun)));
6016 entry_edge = single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun));
6017 orig_entry_edge = entry_edge;
6019 split_prologue_seq = NULL;
6020 if (flag_split_stack
6021 && (lookup_attribute ("no_split_stack", DECL_ATTRIBUTES (cfun->decl))
6022 == NULL))
6024 start_sequence ();
6025 emit_insn (targetm.gen_split_stack_prologue ());
6026 split_prologue_seq = get_insns ();
6027 end_sequence ();
6029 record_insns (split_prologue_seq, NULL, &prologue_insn_hash);
6030 set_insn_locations (split_prologue_seq, prologue_location);
6033 prologue_seq = NULL;
6034 if (targetm.have_prologue ())
6036 start_sequence ();
6037 rtx_insn *seq = targetm.gen_prologue ();
6038 emit_insn (seq);
6040 /* Insert an explicit USE for the frame pointer
6041 if the profiling is on and the frame pointer is required. */
6042 if (crtl->profile && frame_pointer_needed)
6043 emit_use (hard_frame_pointer_rtx);
6045 /* Retain a map of the prologue insns. */
6046 record_insns (seq, NULL, &prologue_insn_hash);
6047 emit_note (NOTE_INSN_PROLOGUE_END);
6049 /* Ensure that instructions are not moved into the prologue when
6050 profiling is on. The call to the profiling routine can be
6051 emitted within the live range of a call-clobbered register. */
6052 if (!targetm.profile_before_prologue () && crtl->profile)
6053 emit_insn (gen_blockage ());
6055 prologue_seq = get_insns ();
6056 end_sequence ();
6057 set_insn_locations (prologue_seq, prologue_location);
6060 bitmap_initialize (&bb_flags, &bitmap_default_obstack);
6062 /* Try to perform a kind of shrink-wrapping, making sure the
6063 prologue/epilogue is emitted only around those parts of the
6064 function that require it. */
6066 try_shrink_wrapping (&entry_edge, &bb_flags, prologue_seq);
6068 if (split_prologue_seq != NULL_RTX)
6070 insert_insn_on_edge (split_prologue_seq, orig_entry_edge);
6071 inserted = true;
6073 if (prologue_seq != NULL_RTX)
6075 insert_insn_on_edge (prologue_seq, entry_edge);
6076 inserted = true;
6079 /* If the exit block has no non-fake predecessors, we don't need
6080 an epilogue. */
6081 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
6082 if ((e->flags & EDGE_FAKE) == 0)
6083 break;
6084 if (e == NULL)
6085 goto epilogue_done;
6087 rtl_profile_for_bb (EXIT_BLOCK_PTR_FOR_FN (cfun));
6089 exit_fallthru_edge = find_fallthru_edge (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds);
6091 if (targetm.have_simple_return () && entry_edge != orig_entry_edge)
6092 exit_fallthru_edge
6093 = get_unconverted_simple_return (exit_fallthru_edge, bb_flags,
6094 &unconverted_simple_returns,
6095 &returnjump);
6096 if (targetm.have_return ())
6098 if (exit_fallthru_edge == NULL)
6099 goto epilogue_done;
6101 if (optimize)
6103 basic_block last_bb = exit_fallthru_edge->src;
6105 if (LABEL_P (BB_HEAD (last_bb))
6106 && !active_insn_between (BB_HEAD (last_bb), BB_END (last_bb)))
6107 convert_jumps_to_returns (last_bb, false, vNULL);
6109 if (EDGE_COUNT (last_bb->preds) != 0
6110 && single_succ_p (last_bb))
6112 last_bb = emit_return_for_exit (exit_fallthru_edge, false);
6113 epilogue_end = returnjump = BB_END (last_bb);
6115 /* Emitting the return may add a basic block.
6116 Fix bb_flags for the added block. */
6117 if (targetm.have_simple_return ()
6118 && last_bb != exit_fallthru_edge->src)
6119 bitmap_set_bit (&bb_flags, last_bb->index);
6121 goto epilogue_done;
6126 /* A small fib -- epilogue is not yet completed, but we wish to re-use
6127 this marker for the splits of EH_RETURN patterns, and nothing else
6128 uses the flag in the meantime. */
6129 epilogue_completed = 1;
6131 /* Find non-fallthru edges that end with EH_RETURN instructions. On
6132 some targets, these get split to a special version of the epilogue
6133 code. In order to be able to properly annotate these with unwind
6134 info, try to split them now. If we get a valid split, drop an
6135 EPILOGUE_BEG note and mark the insns as epilogue insns. */
6136 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
6138 rtx_insn *prev, *last, *trial;
6140 if (e->flags & EDGE_FALLTHRU)
6141 continue;
6142 last = BB_END (e->src);
6143 if (!eh_returnjump_p (last))
6144 continue;
6146 prev = PREV_INSN (last);
6147 trial = try_split (PATTERN (last), last, 1);
6148 if (trial == last)
6149 continue;
6151 record_insns (NEXT_INSN (prev), NEXT_INSN (trial), &epilogue_insn_hash);
6152 emit_note_after (NOTE_INSN_EPILOGUE_BEG, prev);
6155 /* If nothing falls through into the exit block, we don't need an
6156 epilogue. */
6158 if (exit_fallthru_edge == NULL)
6159 goto epilogue_done;
6161 if (targetm.have_epilogue ())
6163 start_sequence ();
6164 epilogue_end = emit_note (NOTE_INSN_EPILOGUE_BEG);
6165 rtx_insn *seq = targetm.gen_epilogue ();
6166 if (seq)
6167 emit_jump_insn (seq);
6169 /* Retain a map of the epilogue insns. */
6170 record_insns (seq, NULL, &epilogue_insn_hash);
6171 set_insn_locations (seq, epilogue_location);
6173 seq = get_insns ();
6174 returnjump = get_last_insn ();
6175 end_sequence ();
6177 insert_insn_on_edge (seq, exit_fallthru_edge);
6178 inserted = true;
6180 if (JUMP_P (returnjump))
6181 set_return_jump_label (returnjump);
6183 else
6185 basic_block cur_bb;
6187 if (! next_active_insn (BB_END (exit_fallthru_edge->src)))
6188 goto epilogue_done;
6189 /* We have a fall-through edge to the exit block, the source is not
6190 at the end of the function, and there will be an assembler epilogue
6191 at the end of the function.
6192 We can't use force_nonfallthru here, because that would try to
6193 use return. Inserting a jump 'by hand' is extremely messy, so
6194 we take advantage of cfg_layout_finalize using
6195 fixup_fallthru_exit_predecessor. */
6196 cfg_layout_initialize (0);
6197 FOR_EACH_BB_FN (cur_bb, cfun)
6198 if (cur_bb->index >= NUM_FIXED_BLOCKS
6199 && cur_bb->next_bb->index >= NUM_FIXED_BLOCKS)
6200 cur_bb->aux = cur_bb->next_bb;
6201 cfg_layout_finalize ();
6204 epilogue_done:
6206 default_rtl_profile ();
6208 if (inserted)
6210 sbitmap blocks;
6212 commit_edge_insertions ();
6214 /* Look for basic blocks within the prologue insns. */
6215 blocks = sbitmap_alloc (last_basic_block_for_fn (cfun));
6216 bitmap_clear (blocks);
6217 bitmap_set_bit (blocks, entry_edge->dest->index);
6218 bitmap_set_bit (blocks, orig_entry_edge->dest->index);
6219 find_many_sub_basic_blocks (blocks);
6220 sbitmap_free (blocks);
6222 /* The epilogue insns we inserted may cause the exit edge to no longer
6223 be fallthru. */
6224 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
6226 if (((e->flags & EDGE_FALLTHRU) != 0)
6227 && returnjump_p (BB_END (e->src)))
6228 e->flags &= ~EDGE_FALLTHRU;
6232 if (targetm.have_simple_return ())
6233 convert_to_simple_return (entry_edge, orig_entry_edge, bb_flags,
6234 returnjump, unconverted_simple_returns);
6236 /* Emit sibling epilogues before any sibling call sites. */
6237 for (ei = ei_start (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds); (e =
6238 ei_safe_edge (ei));
6241 basic_block bb = e->src;
6242 rtx_insn *insn = BB_END (bb);
6244 if (!CALL_P (insn)
6245 || ! SIBLING_CALL_P (insn)
6246 || (targetm.have_simple_return ()
6247 && entry_edge != orig_entry_edge
6248 && !bitmap_bit_p (&bb_flags, bb->index)))
6250 ei_next (&ei);
6251 continue;
6254 if (rtx_insn *ep_seq = targetm.gen_sibcall_epilogue ())
6256 start_sequence ();
6257 emit_note (NOTE_INSN_EPILOGUE_BEG);
6258 emit_insn (ep_seq);
6259 rtx_insn *seq = get_insns ();
6260 end_sequence ();
6262 /* Retain a map of the epilogue insns. Used in life analysis to
6263 avoid getting rid of sibcall epilogue insns. Do this before we
6264 actually emit the sequence. */
6265 record_insns (seq, NULL, &epilogue_insn_hash);
6266 set_insn_locations (seq, epilogue_location);
6268 emit_insn_before (seq, insn);
6270 ei_next (&ei);
6273 if (epilogue_end)
6275 rtx_insn *insn, *next;
6277 /* Similarly, move any line notes that appear after the epilogue.
6278 There is no need, however, to be quite so anal about the existence
6279 of such a note. Also possibly move
6280 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
6281 info generation. */
6282 for (insn = epilogue_end; insn; insn = next)
6284 next = NEXT_INSN (insn);
6285 if (NOTE_P (insn)
6286 && (NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG))
6287 reorder_insns (insn, insn, PREV_INSN (epilogue_end));
6291 bitmap_clear (&bb_flags);
6293 /* Threading the prologue and epilogue changes the artificial refs
6294 in the entry and exit blocks. */
6295 epilogue_completed = 1;
6296 df_update_entry_exit_and_calls ();
6299 /* Reposition the prologue-end and epilogue-begin notes after
6300 instruction scheduling. */
6302 void
6303 reposition_prologue_and_epilogue_notes (void)
6305 if (!targetm.have_prologue ()
6306 && !targetm.have_epilogue ()
6307 && !targetm.have_sibcall_epilogue ())
6308 return;
6310 /* Since the hash table is created on demand, the fact that it is
6311 non-null is a signal that it is non-empty. */
6312 if (prologue_insn_hash != NULL)
6314 size_t len = prologue_insn_hash->elements ();
6315 rtx_insn *insn, *last = NULL, *note = NULL;
6317 /* Scan from the beginning until we reach the last prologue insn. */
6318 /* ??? While we do have the CFG intact, there are two problems:
6319 (1) The prologue can contain loops (typically probing the stack),
6320 which means that the end of the prologue isn't in the first bb.
6321 (2) Sometimes the PROLOGUE_END note gets pushed into the next bb. */
6322 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
6324 if (NOTE_P (insn))
6326 if (NOTE_KIND (insn) == NOTE_INSN_PROLOGUE_END)
6327 note = insn;
6329 else if (contains (insn, prologue_insn_hash))
6331 last = insn;
6332 if (--len == 0)
6333 break;
6337 if (last)
6339 if (note == NULL)
6341 /* Scan forward looking for the PROLOGUE_END note. It should
6342 be right at the beginning of the block, possibly with other
6343 insn notes that got moved there. */
6344 for (note = NEXT_INSN (last); ; note = NEXT_INSN (note))
6346 if (NOTE_P (note)
6347 && NOTE_KIND (note) == NOTE_INSN_PROLOGUE_END)
6348 break;
6352 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
6353 if (LABEL_P (last))
6354 last = NEXT_INSN (last);
6355 reorder_insns (note, note, last);
6359 if (epilogue_insn_hash != NULL)
6361 edge_iterator ei;
6362 edge e;
6364 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
6366 rtx_insn *insn, *first = NULL, *note = NULL;
6367 basic_block bb = e->src;
6369 /* Scan from the beginning until we reach the first epilogue insn. */
6370 FOR_BB_INSNS (bb, insn)
6372 if (NOTE_P (insn))
6374 if (NOTE_KIND (insn) == NOTE_INSN_EPILOGUE_BEG)
6376 note = insn;
6377 if (first != NULL)
6378 break;
6381 else if (first == NULL && contains (insn, epilogue_insn_hash))
6383 first = insn;
6384 if (note != NULL)
6385 break;
6389 if (note)
6391 /* If the function has a single basic block, and no real
6392 epilogue insns (e.g. sibcall with no cleanup), the
6393 epilogue note can get scheduled before the prologue
6394 note. If we have frame related prologue insns, having
6395 them scanned during the epilogue will result in a crash.
6396 In this case re-order the epilogue note to just before
6397 the last insn in the block. */
6398 if (first == NULL)
6399 first = BB_END (bb);
6401 if (PREV_INSN (first) != note)
6402 reorder_insns (note, note, PREV_INSN (first));
6408 /* Returns the name of function declared by FNDECL. */
6409 const char *
6410 fndecl_name (tree fndecl)
6412 if (fndecl == NULL)
6413 return "(nofn)";
6414 return lang_hooks.decl_printable_name (fndecl, 2);
6417 /* Returns the name of function FN. */
6418 const char *
6419 function_name (struct function *fn)
6421 tree fndecl = (fn == NULL) ? NULL : fn->decl;
6422 return fndecl_name (fndecl);
6425 /* Returns the name of the current function. */
6426 const char *
6427 current_function_name (void)
6429 return function_name (cfun);
6433 static unsigned int
6434 rest_of_handle_check_leaf_regs (void)
6436 #ifdef LEAF_REGISTERS
6437 crtl->uses_only_leaf_regs
6438 = optimize > 0 && only_leaf_regs_used () && leaf_function_p ();
6439 #endif
6440 return 0;
6443 /* Insert a TYPE into the used types hash table of CFUN. */
6445 static void
6446 used_types_insert_helper (tree type, struct function *func)
6448 if (type != NULL && func != NULL)
6450 if (func->used_types_hash == NULL)
6451 func->used_types_hash = hash_set<tree>::create_ggc (37);
6453 func->used_types_hash->add (type);
6457 /* Given a type, insert it into the used hash table in cfun. */
6458 void
6459 used_types_insert (tree t)
6461 while (POINTER_TYPE_P (t) || TREE_CODE (t) == ARRAY_TYPE)
6462 if (TYPE_NAME (t))
6463 break;
6464 else
6465 t = TREE_TYPE (t);
6466 if (TREE_CODE (t) == ERROR_MARK)
6467 return;
6468 if (TYPE_NAME (t) == NULL_TREE
6469 || TYPE_NAME (t) == TYPE_NAME (TYPE_MAIN_VARIANT (t)))
6470 t = TYPE_MAIN_VARIANT (t);
6471 if (debug_info_level > DINFO_LEVEL_NONE)
6473 if (cfun)
6474 used_types_insert_helper (t, cfun);
6475 else
6477 /* So this might be a type referenced by a global variable.
6478 Record that type so that we can later decide to emit its
6479 debug information. */
6480 vec_safe_push (types_used_by_cur_var_decl, t);
6485 /* Helper to Hash a struct types_used_by_vars_entry. */
6487 static hashval_t
6488 hash_types_used_by_vars_entry (const struct types_used_by_vars_entry *entry)
6490 gcc_assert (entry && entry->var_decl && entry->type);
6492 return iterative_hash_object (entry->type,
6493 iterative_hash_object (entry->var_decl, 0));
6496 /* Hash function of the types_used_by_vars_entry hash table. */
6498 hashval_t
6499 used_type_hasher::hash (types_used_by_vars_entry *entry)
6501 return hash_types_used_by_vars_entry (entry);
6504 /*Equality function of the types_used_by_vars_entry hash table. */
6506 bool
6507 used_type_hasher::equal (types_used_by_vars_entry *e1,
6508 types_used_by_vars_entry *e2)
6510 return (e1->var_decl == e2->var_decl && e1->type == e2->type);
6513 /* Inserts an entry into the types_used_by_vars_hash hash table. */
6515 void
6516 types_used_by_var_decl_insert (tree type, tree var_decl)
6518 if (type != NULL && var_decl != NULL)
6520 types_used_by_vars_entry **slot;
6521 struct types_used_by_vars_entry e;
6522 e.var_decl = var_decl;
6523 e.type = type;
6524 if (types_used_by_vars_hash == NULL)
6525 types_used_by_vars_hash
6526 = hash_table<used_type_hasher>::create_ggc (37);
6528 slot = types_used_by_vars_hash->find_slot (&e, INSERT);
6529 if (*slot == NULL)
6531 struct types_used_by_vars_entry *entry;
6532 entry = ggc_alloc<types_used_by_vars_entry> ();
6533 entry->type = type;
6534 entry->var_decl = var_decl;
6535 *slot = entry;
6540 namespace {
6542 const pass_data pass_data_leaf_regs =
6544 RTL_PASS, /* type */
6545 "*leaf_regs", /* name */
6546 OPTGROUP_NONE, /* optinfo_flags */
6547 TV_NONE, /* tv_id */
6548 0, /* properties_required */
6549 0, /* properties_provided */
6550 0, /* properties_destroyed */
6551 0, /* todo_flags_start */
6552 0, /* todo_flags_finish */
6555 class pass_leaf_regs : public rtl_opt_pass
6557 public:
6558 pass_leaf_regs (gcc::context *ctxt)
6559 : rtl_opt_pass (pass_data_leaf_regs, ctxt)
6562 /* opt_pass methods: */
6563 virtual unsigned int execute (function *)
6565 return rest_of_handle_check_leaf_regs ();
6568 }; // class pass_leaf_regs
6570 } // anon namespace
6572 rtl_opt_pass *
6573 make_pass_leaf_regs (gcc::context *ctxt)
6575 return new pass_leaf_regs (ctxt);
6578 static unsigned int
6579 rest_of_handle_thread_prologue_and_epilogue (void)
6581 if (optimize)
6582 cleanup_cfg (CLEANUP_EXPENSIVE);
6584 /* On some machines, the prologue and epilogue code, or parts thereof,
6585 can be represented as RTL. Doing so lets us schedule insns between
6586 it and the rest of the code and also allows delayed branch
6587 scheduling to operate in the epilogue. */
6588 thread_prologue_and_epilogue_insns ();
6590 /* Some non-cold blocks may now be only reachable from cold blocks.
6591 Fix that up. */
6592 fixup_partitions ();
6594 /* Shrink-wrapping can result in unreachable edges in the epilogue,
6595 see PR57320. */
6596 cleanup_cfg (0);
6598 /* The stack usage info is finalized during prologue expansion. */
6599 if (flag_stack_usage_info)
6600 output_stack_usage ();
6602 return 0;
6605 namespace {
6607 const pass_data pass_data_thread_prologue_and_epilogue =
6609 RTL_PASS, /* type */
6610 "pro_and_epilogue", /* name */
6611 OPTGROUP_NONE, /* optinfo_flags */
6612 TV_THREAD_PROLOGUE_AND_EPILOGUE, /* tv_id */
6613 0, /* properties_required */
6614 0, /* properties_provided */
6615 0, /* properties_destroyed */
6616 0, /* todo_flags_start */
6617 ( TODO_df_verify | TODO_df_finish ), /* todo_flags_finish */
6620 class pass_thread_prologue_and_epilogue : public rtl_opt_pass
6622 public:
6623 pass_thread_prologue_and_epilogue (gcc::context *ctxt)
6624 : rtl_opt_pass (pass_data_thread_prologue_and_epilogue, ctxt)
6627 /* opt_pass methods: */
6628 virtual unsigned int execute (function *)
6630 return rest_of_handle_thread_prologue_and_epilogue ();
6633 }; // class pass_thread_prologue_and_epilogue
6635 } // anon namespace
6637 rtl_opt_pass *
6638 make_pass_thread_prologue_and_epilogue (gcc::context *ctxt)
6640 return new pass_thread_prologue_and_epilogue (ctxt);
6644 /* This mini-pass fixes fall-out from SSA in asm statements that have
6645 in-out constraints. Say you start with
6647 orig = inout;
6648 asm ("": "+mr" (inout));
6649 use (orig);
6651 which is transformed very early to use explicit output and match operands:
6653 orig = inout;
6654 asm ("": "=mr" (inout) : "0" (inout));
6655 use (orig);
6657 Or, after SSA and copyprop,
6659 asm ("": "=mr" (inout_2) : "0" (inout_1));
6660 use (inout_1);
6662 Clearly inout_2 and inout_1 can't be coalesced easily anymore, as
6663 they represent two separate values, so they will get different pseudo
6664 registers during expansion. Then, since the two operands need to match
6665 per the constraints, but use different pseudo registers, reload can
6666 only register a reload for these operands. But reloads can only be
6667 satisfied by hardregs, not by memory, so we need a register for this
6668 reload, just because we are presented with non-matching operands.
6669 So, even though we allow memory for this operand, no memory can be
6670 used for it, just because the two operands don't match. This can
6671 cause reload failures on register-starved targets.
6673 So it's a symptom of reload not being able to use memory for reloads
6674 or, alternatively it's also a symptom of both operands not coming into
6675 reload as matching (in which case the pseudo could go to memory just
6676 fine, as the alternative allows it, and no reload would be necessary).
6677 We fix the latter problem here, by transforming
6679 asm ("": "=mr" (inout_2) : "0" (inout_1));
6681 back to
6683 inout_2 = inout_1;
6684 asm ("": "=mr" (inout_2) : "0" (inout_2)); */
6686 static void
6687 match_asm_constraints_1 (rtx_insn *insn, rtx *p_sets, int noutputs)
6689 int i;
6690 bool changed = false;
6691 rtx op = SET_SRC (p_sets[0]);
6692 int ninputs = ASM_OPERANDS_INPUT_LENGTH (op);
6693 rtvec inputs = ASM_OPERANDS_INPUT_VEC (op);
6694 bool *output_matched = XALLOCAVEC (bool, noutputs);
6696 memset (output_matched, 0, noutputs * sizeof (bool));
6697 for (i = 0; i < ninputs; i++)
6699 rtx input, output;
6700 rtx_insn *insns;
6701 const char *constraint = ASM_OPERANDS_INPUT_CONSTRAINT (op, i);
6702 char *end;
6703 int match, j;
6705 if (*constraint == '%')
6706 constraint++;
6708 match = strtoul (constraint, &end, 10);
6709 if (end == constraint)
6710 continue;
6712 gcc_assert (match < noutputs);
6713 output = SET_DEST (p_sets[match]);
6714 input = RTVEC_ELT (inputs, i);
6715 /* Only do the transformation for pseudos. */
6716 if (! REG_P (output)
6717 || rtx_equal_p (output, input)
6718 || (GET_MODE (input) != VOIDmode
6719 && GET_MODE (input) != GET_MODE (output)))
6720 continue;
6722 /* We can't do anything if the output is also used as input,
6723 as we're going to overwrite it. */
6724 for (j = 0; j < ninputs; j++)
6725 if (reg_overlap_mentioned_p (output, RTVEC_ELT (inputs, j)))
6726 break;
6727 if (j != ninputs)
6728 continue;
6730 /* Avoid changing the same input several times. For
6731 asm ("" : "=mr" (out1), "=mr" (out2) : "0" (in), "1" (in));
6732 only change in once (to out1), rather than changing it
6733 first to out1 and afterwards to out2. */
6734 if (i > 0)
6736 for (j = 0; j < noutputs; j++)
6737 if (output_matched[j] && input == SET_DEST (p_sets[j]))
6738 break;
6739 if (j != noutputs)
6740 continue;
6742 output_matched[match] = true;
6744 start_sequence ();
6745 emit_move_insn (output, input);
6746 insns = get_insns ();
6747 end_sequence ();
6748 emit_insn_before (insns, insn);
6750 /* Now replace all mentions of the input with output. We can't
6751 just replace the occurrence in inputs[i], as the register might
6752 also be used in some other input (or even in an address of an
6753 output), which would mean possibly increasing the number of
6754 inputs by one (namely 'output' in addition), which might pose
6755 a too complicated problem for reload to solve. E.g. this situation:
6757 asm ("" : "=r" (output), "=m" (input) : "0" (input))
6759 Here 'input' is used in two occurrences as input (once for the
6760 input operand, once for the address in the second output operand).
6761 If we would replace only the occurrence of the input operand (to
6762 make the matching) we would be left with this:
6764 output = input
6765 asm ("" : "=r" (output), "=m" (input) : "0" (output))
6767 Now we suddenly have two different input values (containing the same
6768 value, but different pseudos) where we formerly had only one.
6769 With more complicated asms this might lead to reload failures
6770 which wouldn't have happen without this pass. So, iterate over
6771 all operands and replace all occurrences of the register used. */
6772 for (j = 0; j < noutputs; j++)
6773 if (!rtx_equal_p (SET_DEST (p_sets[j]), input)
6774 && reg_overlap_mentioned_p (input, SET_DEST (p_sets[j])))
6775 SET_DEST (p_sets[j]) = replace_rtx (SET_DEST (p_sets[j]),
6776 input, output);
6777 for (j = 0; j < ninputs; j++)
6778 if (reg_overlap_mentioned_p (input, RTVEC_ELT (inputs, j)))
6779 RTVEC_ELT (inputs, j) = replace_rtx (RTVEC_ELT (inputs, j),
6780 input, output);
6782 changed = true;
6785 if (changed)
6786 df_insn_rescan (insn);
6789 /* Add the decl D to the local_decls list of FUN. */
6791 void
6792 add_local_decl (struct function *fun, tree d)
6794 gcc_assert (TREE_CODE (d) == VAR_DECL);
6795 vec_safe_push (fun->local_decls, d);
6798 namespace {
6800 const pass_data pass_data_match_asm_constraints =
6802 RTL_PASS, /* type */
6803 "asmcons", /* name */
6804 OPTGROUP_NONE, /* optinfo_flags */
6805 TV_NONE, /* tv_id */
6806 0, /* properties_required */
6807 0, /* properties_provided */
6808 0, /* properties_destroyed */
6809 0, /* todo_flags_start */
6810 0, /* todo_flags_finish */
6813 class pass_match_asm_constraints : public rtl_opt_pass
6815 public:
6816 pass_match_asm_constraints (gcc::context *ctxt)
6817 : rtl_opt_pass (pass_data_match_asm_constraints, ctxt)
6820 /* opt_pass methods: */
6821 virtual unsigned int execute (function *);
6823 }; // class pass_match_asm_constraints
6825 unsigned
6826 pass_match_asm_constraints::execute (function *fun)
6828 basic_block bb;
6829 rtx_insn *insn;
6830 rtx pat, *p_sets;
6831 int noutputs;
6833 if (!crtl->has_asm_statement)
6834 return 0;
6836 df_set_flags (DF_DEFER_INSN_RESCAN);
6837 FOR_EACH_BB_FN (bb, fun)
6839 FOR_BB_INSNS (bb, insn)
6841 if (!INSN_P (insn))
6842 continue;
6844 pat = PATTERN (insn);
6845 if (GET_CODE (pat) == PARALLEL)
6846 p_sets = &XVECEXP (pat, 0, 0), noutputs = XVECLEN (pat, 0);
6847 else if (GET_CODE (pat) == SET)
6848 p_sets = &PATTERN (insn), noutputs = 1;
6849 else
6850 continue;
6852 if (GET_CODE (*p_sets) == SET
6853 && GET_CODE (SET_SRC (*p_sets)) == ASM_OPERANDS)
6854 match_asm_constraints_1 (insn, p_sets, noutputs);
6858 return TODO_df_finish;
6861 } // anon namespace
6863 rtl_opt_pass *
6864 make_pass_match_asm_constraints (gcc::context *ctxt)
6866 return new pass_match_asm_constraints (ctxt);
6870 #include "gt-function.h"