[SFN] boilerplate changes in preparation to introduce nonbind markers
[official-gcc.git] / gcc / function.c
blob88f93db6cf0fd674ae0c5e8116417868c0ed249d
1 /* Expands front end tree to back end RTL for GCC.
2 Copyright (C) 1987-2017 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 for more details.
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
20 /* This file handles the generation of rtl code from tree structure
21 at the level of the function as a whole.
22 It creates the rtl expressions for parameters and auto variables
23 and has full responsibility for allocating stack slots.
25 `expand_function_start' is called at the beginning of a function,
26 before the function body is parsed, and `expand_function_end' is
27 called after parsing the body.
29 Call `assign_stack_local' to allocate a stack slot for a local variable.
30 This is usually done during the RTL generation for the function body,
31 but it can also be done in the reload pass when a pseudo-register does
32 not get a hard register. */
34 #include "config.h"
35 #include "system.h"
36 #include "coretypes.h"
37 #include "backend.h"
38 #include "target.h"
39 #include "rtl.h"
40 #include "tree.h"
41 #include "gimple-expr.h"
42 #include "cfghooks.h"
43 #include "df.h"
44 #include "memmodel.h"
45 #include "tm_p.h"
46 #include "stringpool.h"
47 #include "expmed.h"
48 #include "optabs.h"
49 #include "regs.h"
50 #include "emit-rtl.h"
51 #include "recog.h"
52 #include "rtl-error.h"
53 #include "alias.h"
54 #include "fold-const.h"
55 #include "stor-layout.h"
56 #include "varasm.h"
57 #include "except.h"
58 #include "dojump.h"
59 #include "explow.h"
60 #include "calls.h"
61 #include "expr.h"
62 #include "optabs-tree.h"
63 #include "output.h"
64 #include "langhooks.h"
65 #include "common/common-target.h"
66 #include "gimplify.h"
67 #include "tree-pass.h"
68 #include "cfgrtl.h"
69 #include "cfganal.h"
70 #include "cfgbuild.h"
71 #include "cfgcleanup.h"
72 #include "cfgexpand.h"
73 #include "shrink-wrap.h"
74 #include "toplev.h"
75 #include "rtl-iter.h"
76 #include "tree-chkp.h"
77 #include "rtl-chkp.h"
78 #include "tree-dfa.h"
79 #include "tree-ssa.h"
80 #include "stringpool.h"
81 #include "attribs.h"
83 /* So we can assign to cfun in this file. */
84 #undef cfun
86 #ifndef STACK_ALIGNMENT_NEEDED
87 #define STACK_ALIGNMENT_NEEDED 1
88 #endif
90 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
92 /* Round a value to the lowest integer less than it that is a multiple of
93 the required alignment. Avoid using division in case the value is
94 negative. Assume the alignment is a power of two. */
95 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
97 /* Similar, but round to the next highest integer that meets the
98 alignment. */
99 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
101 /* Nonzero once virtual register instantiation has been done.
102 assign_stack_local uses frame_pointer_rtx when this is nonzero.
103 calls.c:emit_library_call_value_1 uses it to set up
104 post-instantiation libcalls. */
105 int virtuals_instantiated;
107 /* Assign unique numbers to labels generated for profiling, debugging, etc. */
108 static GTY(()) int funcdef_no;
110 /* These variables hold pointers to functions to create and destroy
111 target specific, per-function data structures. */
112 struct machine_function * (*init_machine_status) (void);
114 /* The currently compiled function. */
115 struct function *cfun = 0;
117 /* These hashes record the prologue and epilogue insns. */
119 struct insn_cache_hasher : ggc_cache_ptr_hash<rtx_def>
121 static hashval_t hash (rtx x) { return htab_hash_pointer (x); }
122 static bool equal (rtx a, rtx b) { return a == b; }
125 static GTY((cache))
126 hash_table<insn_cache_hasher> *prologue_insn_hash;
127 static GTY((cache))
128 hash_table<insn_cache_hasher> *epilogue_insn_hash;
131 hash_table<used_type_hasher> *types_used_by_vars_hash = NULL;
132 vec<tree, va_gc> *types_used_by_cur_var_decl;
134 /* Forward declarations. */
136 static struct temp_slot *find_temp_slot_from_address (rtx);
137 static void pad_to_arg_alignment (struct args_size *, int, struct args_size *);
138 static void pad_below (struct args_size *, machine_mode, tree);
139 static void reorder_blocks_1 (rtx_insn *, tree, vec<tree> *);
140 static int all_blocks (tree, tree *);
141 static tree *get_block_vector (tree, int *);
142 extern tree debug_find_var_in_block_tree (tree, tree);
143 /* We always define `record_insns' even if it's not used so that we
144 can always export `prologue_epilogue_contains'. */
145 static void record_insns (rtx_insn *, rtx, hash_table<insn_cache_hasher> **)
146 ATTRIBUTE_UNUSED;
147 static bool contains (const rtx_insn *, hash_table<insn_cache_hasher> *);
148 static void prepare_function_start (void);
149 static void do_clobber_return_reg (rtx, void *);
150 static void do_use_return_reg (rtx, void *);
153 /* Stack of nested functions. */
154 /* Keep track of the cfun stack. */
156 static vec<function *> function_context_stack;
158 /* Save the current context for compilation of a nested function.
159 This is called from language-specific code. */
161 void
162 push_function_context (void)
164 if (cfun == 0)
165 allocate_struct_function (NULL, false);
167 function_context_stack.safe_push (cfun);
168 set_cfun (NULL);
171 /* Restore the last saved context, at the end of a nested function.
172 This function is called from language-specific code. */
174 void
175 pop_function_context (void)
177 struct function *p = function_context_stack.pop ();
178 set_cfun (p);
179 current_function_decl = p->decl;
181 /* Reset variables that have known state during rtx generation. */
182 virtuals_instantiated = 0;
183 generating_concat_p = 1;
186 /* Clear out all parts of the state in F that can safely be discarded
187 after the function has been parsed, but not compiled, to let
188 garbage collection reclaim the memory. */
190 void
191 free_after_parsing (struct function *f)
193 f->language = 0;
196 /* Clear out all parts of the state in F that can safely be discarded
197 after the function has been compiled, to let garbage collection
198 reclaim the memory. */
200 void
201 free_after_compilation (struct function *f)
203 prologue_insn_hash = NULL;
204 epilogue_insn_hash = NULL;
206 free (crtl->emit.regno_pointer_align);
208 memset (crtl, 0, sizeof (struct rtl_data));
209 f->eh = NULL;
210 f->machine = NULL;
211 f->cfg = NULL;
212 f->curr_properties &= ~PROP_cfg;
214 regno_reg_rtx = NULL;
217 /* Return size needed for stack frame based on slots so far allocated.
218 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
219 the caller may have to do that. */
221 HOST_WIDE_INT
222 get_frame_size (void)
224 if (FRAME_GROWS_DOWNWARD)
225 return -frame_offset;
226 else
227 return frame_offset;
230 /* Issue an error message and return TRUE if frame OFFSET overflows in
231 the signed target pointer arithmetics for function FUNC. Otherwise
232 return FALSE. */
234 bool
235 frame_offset_overflow (HOST_WIDE_INT offset, tree func)
237 unsigned HOST_WIDE_INT size = FRAME_GROWS_DOWNWARD ? -offset : offset;
239 if (size > (HOST_WIDE_INT_1U << (GET_MODE_BITSIZE (Pmode) - 1))
240 /* Leave room for the fixed part of the frame. */
241 - 64 * UNITS_PER_WORD)
243 error_at (DECL_SOURCE_LOCATION (func),
244 "total size of local objects too large");
245 return TRUE;
248 return FALSE;
251 /* Return the minimum spill slot alignment for a register of mode MODE. */
253 unsigned int
254 spill_slot_alignment (machine_mode mode ATTRIBUTE_UNUSED)
256 return STACK_SLOT_ALIGNMENT (NULL_TREE, mode, GET_MODE_ALIGNMENT (mode));
259 /* Return stack slot alignment in bits for TYPE and MODE. */
261 static unsigned int
262 get_stack_local_alignment (tree type, machine_mode mode)
264 unsigned int alignment;
266 if (mode == BLKmode)
267 alignment = BIGGEST_ALIGNMENT;
268 else
269 alignment = GET_MODE_ALIGNMENT (mode);
271 /* Allow the frond-end to (possibly) increase the alignment of this
272 stack slot. */
273 if (! type)
274 type = lang_hooks.types.type_for_mode (mode, 0);
276 return STACK_SLOT_ALIGNMENT (type, mode, alignment);
279 /* Determine whether it is possible to fit a stack slot of size SIZE and
280 alignment ALIGNMENT into an area in the stack frame that starts at
281 frame offset START and has a length of LENGTH. If so, store the frame
282 offset to be used for the stack slot in *POFFSET and return true;
283 return false otherwise. This function will extend the frame size when
284 given a start/length pair that lies at the end of the frame. */
286 static bool
287 try_fit_stack_local (HOST_WIDE_INT start, HOST_WIDE_INT length,
288 HOST_WIDE_INT size, unsigned int alignment,
289 HOST_WIDE_INT *poffset)
291 HOST_WIDE_INT this_frame_offset;
292 int frame_off, frame_alignment, frame_phase;
294 /* Calculate how many bytes the start of local variables is off from
295 stack alignment. */
296 frame_alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
297 frame_off = targetm.starting_frame_offset () % frame_alignment;
298 frame_phase = frame_off ? frame_alignment - frame_off : 0;
300 /* Round the frame offset to the specified alignment. */
302 /* We must be careful here, since FRAME_OFFSET might be negative and
303 division with a negative dividend isn't as well defined as we might
304 like. So we instead assume that ALIGNMENT is a power of two and
305 use logical operations which are unambiguous. */
306 if (FRAME_GROWS_DOWNWARD)
307 this_frame_offset
308 = (FLOOR_ROUND (start + length - size - frame_phase,
309 (unsigned HOST_WIDE_INT) alignment)
310 + frame_phase);
311 else
312 this_frame_offset
313 = (CEIL_ROUND (start - frame_phase,
314 (unsigned HOST_WIDE_INT) alignment)
315 + frame_phase);
317 /* See if it fits. If this space is at the edge of the frame,
318 consider extending the frame to make it fit. Our caller relies on
319 this when allocating a new slot. */
320 if (frame_offset == start && this_frame_offset < frame_offset)
321 frame_offset = this_frame_offset;
322 else if (this_frame_offset < start)
323 return false;
324 else if (start + length == frame_offset
325 && this_frame_offset + size > start + length)
326 frame_offset = this_frame_offset + size;
327 else if (this_frame_offset + size > start + length)
328 return false;
330 *poffset = this_frame_offset;
331 return true;
334 /* Create a new frame_space structure describing free space in the stack
335 frame beginning at START and ending at END, and chain it into the
336 function's frame_space_list. */
338 static void
339 add_frame_space (HOST_WIDE_INT start, HOST_WIDE_INT end)
341 struct frame_space *space = ggc_alloc<frame_space> ();
342 space->next = crtl->frame_space_list;
343 crtl->frame_space_list = space;
344 space->start = start;
345 space->length = end - start;
348 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
349 with machine mode MODE.
351 ALIGN controls the amount of alignment for the address of the slot:
352 0 means according to MODE,
353 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
354 -2 means use BITS_PER_UNIT,
355 positive specifies alignment boundary in bits.
357 KIND has ASLK_REDUCE_ALIGN bit set if it is OK to reduce
358 alignment and ASLK_RECORD_PAD bit set if we should remember
359 extra space we allocated for alignment purposes. When we are
360 called from assign_stack_temp_for_type, it is not set so we don't
361 track the same stack slot in two independent lists.
363 We do not round to stack_boundary here. */
366 assign_stack_local_1 (machine_mode mode, HOST_WIDE_INT size,
367 int align, int kind)
369 rtx x, addr;
370 int bigend_correction = 0;
371 HOST_WIDE_INT slot_offset = 0, old_frame_offset;
372 unsigned int alignment, alignment_in_bits;
374 if (align == 0)
376 alignment = get_stack_local_alignment (NULL, mode);
377 alignment /= BITS_PER_UNIT;
379 else if (align == -1)
381 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
382 size = CEIL_ROUND (size, alignment);
384 else if (align == -2)
385 alignment = 1; /* BITS_PER_UNIT / BITS_PER_UNIT */
386 else
387 alignment = align / BITS_PER_UNIT;
389 alignment_in_bits = alignment * BITS_PER_UNIT;
391 /* Ignore alignment if it exceeds MAX_SUPPORTED_STACK_ALIGNMENT. */
392 if (alignment_in_bits > MAX_SUPPORTED_STACK_ALIGNMENT)
394 alignment_in_bits = MAX_SUPPORTED_STACK_ALIGNMENT;
395 alignment = alignment_in_bits / BITS_PER_UNIT;
398 if (SUPPORTS_STACK_ALIGNMENT)
400 if (crtl->stack_alignment_estimated < alignment_in_bits)
402 if (!crtl->stack_realign_processed)
403 crtl->stack_alignment_estimated = alignment_in_bits;
404 else
406 /* If stack is realigned and stack alignment value
407 hasn't been finalized, it is OK not to increase
408 stack_alignment_estimated. The bigger alignment
409 requirement is recorded in stack_alignment_needed
410 below. */
411 gcc_assert (!crtl->stack_realign_finalized);
412 if (!crtl->stack_realign_needed)
414 /* It is OK to reduce the alignment as long as the
415 requested size is 0 or the estimated stack
416 alignment >= mode alignment. */
417 gcc_assert ((kind & ASLK_REDUCE_ALIGN)
418 || size == 0
419 || (crtl->stack_alignment_estimated
420 >= GET_MODE_ALIGNMENT (mode)));
421 alignment_in_bits = crtl->stack_alignment_estimated;
422 alignment = alignment_in_bits / BITS_PER_UNIT;
428 if (crtl->stack_alignment_needed < alignment_in_bits)
429 crtl->stack_alignment_needed = alignment_in_bits;
430 if (crtl->max_used_stack_slot_alignment < alignment_in_bits)
431 crtl->max_used_stack_slot_alignment = alignment_in_bits;
433 if (mode != BLKmode || size != 0)
435 if (kind & ASLK_RECORD_PAD)
437 struct frame_space **psp;
439 for (psp = &crtl->frame_space_list; *psp; psp = &(*psp)->next)
441 struct frame_space *space = *psp;
442 if (!try_fit_stack_local (space->start, space->length, size,
443 alignment, &slot_offset))
444 continue;
445 *psp = space->next;
446 if (slot_offset > space->start)
447 add_frame_space (space->start, slot_offset);
448 if (slot_offset + size < space->start + space->length)
449 add_frame_space (slot_offset + size,
450 space->start + space->length);
451 goto found_space;
455 else if (!STACK_ALIGNMENT_NEEDED)
457 slot_offset = frame_offset;
458 goto found_space;
461 old_frame_offset = frame_offset;
463 if (FRAME_GROWS_DOWNWARD)
465 frame_offset -= size;
466 try_fit_stack_local (frame_offset, size, size, alignment, &slot_offset);
468 if (kind & ASLK_RECORD_PAD)
470 if (slot_offset > frame_offset)
471 add_frame_space (frame_offset, slot_offset);
472 if (slot_offset + size < old_frame_offset)
473 add_frame_space (slot_offset + size, old_frame_offset);
476 else
478 frame_offset += size;
479 try_fit_stack_local (old_frame_offset, size, size, alignment, &slot_offset);
481 if (kind & ASLK_RECORD_PAD)
483 if (slot_offset > old_frame_offset)
484 add_frame_space (old_frame_offset, slot_offset);
485 if (slot_offset + size < frame_offset)
486 add_frame_space (slot_offset + size, frame_offset);
490 found_space:
491 /* On a big-endian machine, if we are allocating more space than we will use,
492 use the least significant bytes of those that are allocated. */
493 if (BYTES_BIG_ENDIAN && mode != BLKmode && GET_MODE_SIZE (mode) < size)
494 bigend_correction = size - GET_MODE_SIZE (mode);
496 /* If we have already instantiated virtual registers, return the actual
497 address relative to the frame pointer. */
498 if (virtuals_instantiated)
499 addr = plus_constant (Pmode, frame_pointer_rtx,
500 trunc_int_for_mode
501 (slot_offset + bigend_correction
502 + targetm.starting_frame_offset (), Pmode));
503 else
504 addr = plus_constant (Pmode, virtual_stack_vars_rtx,
505 trunc_int_for_mode
506 (slot_offset + bigend_correction,
507 Pmode));
509 x = gen_rtx_MEM (mode, addr);
510 set_mem_align (x, alignment_in_bits);
511 MEM_NOTRAP_P (x) = 1;
513 vec_safe_push (stack_slot_list, x);
515 if (frame_offset_overflow (frame_offset, current_function_decl))
516 frame_offset = 0;
518 return x;
521 /* Wrap up assign_stack_local_1 with last parameter as false. */
524 assign_stack_local (machine_mode mode, HOST_WIDE_INT size, int align)
526 return assign_stack_local_1 (mode, size, align, ASLK_RECORD_PAD);
529 /* In order to evaluate some expressions, such as function calls returning
530 structures in memory, we need to temporarily allocate stack locations.
531 We record each allocated temporary in the following structure.
533 Associated with each temporary slot is a nesting level. When we pop up
534 one level, all temporaries associated with the previous level are freed.
535 Normally, all temporaries are freed after the execution of the statement
536 in which they were created. However, if we are inside a ({...}) grouping,
537 the result may be in a temporary and hence must be preserved. If the
538 result could be in a temporary, we preserve it if we can determine which
539 one it is in. If we cannot determine which temporary may contain the
540 result, all temporaries are preserved. A temporary is preserved by
541 pretending it was allocated at the previous nesting level. */
543 struct GTY(()) temp_slot {
544 /* Points to next temporary slot. */
545 struct temp_slot *next;
546 /* Points to previous temporary slot. */
547 struct temp_slot *prev;
548 /* The rtx to used to reference the slot. */
549 rtx slot;
550 /* The size, in units, of the slot. */
551 HOST_WIDE_INT size;
552 /* The type of the object in the slot, or zero if it doesn't correspond
553 to a type. We use this to determine whether a slot can be reused.
554 It can be reused if objects of the type of the new slot will always
555 conflict with objects of the type of the old slot. */
556 tree type;
557 /* The alignment (in bits) of the slot. */
558 unsigned int align;
559 /* Nonzero if this temporary is currently in use. */
560 char in_use;
561 /* Nesting level at which this slot is being used. */
562 int level;
563 /* The offset of the slot from the frame_pointer, including extra space
564 for alignment. This info is for combine_temp_slots. */
565 HOST_WIDE_INT base_offset;
566 /* The size of the slot, including extra space for alignment. This
567 info is for combine_temp_slots. */
568 HOST_WIDE_INT full_size;
571 /* Entry for the below hash table. */
572 struct GTY((for_user)) temp_slot_address_entry {
573 hashval_t hash;
574 rtx address;
575 struct temp_slot *temp_slot;
578 struct temp_address_hasher : ggc_ptr_hash<temp_slot_address_entry>
580 static hashval_t hash (temp_slot_address_entry *);
581 static bool equal (temp_slot_address_entry *, temp_slot_address_entry *);
584 /* A table of addresses that represent a stack slot. The table is a mapping
585 from address RTXen to a temp slot. */
586 static GTY(()) hash_table<temp_address_hasher> *temp_slot_address_table;
587 static size_t n_temp_slots_in_use;
589 /* Removes temporary slot TEMP from LIST. */
591 static void
592 cut_slot_from_list (struct temp_slot *temp, struct temp_slot **list)
594 if (temp->next)
595 temp->next->prev = temp->prev;
596 if (temp->prev)
597 temp->prev->next = temp->next;
598 else
599 *list = temp->next;
601 temp->prev = temp->next = NULL;
604 /* Inserts temporary slot TEMP to LIST. */
606 static void
607 insert_slot_to_list (struct temp_slot *temp, struct temp_slot **list)
609 temp->next = *list;
610 if (*list)
611 (*list)->prev = temp;
612 temp->prev = NULL;
613 *list = temp;
616 /* Returns the list of used temp slots at LEVEL. */
618 static struct temp_slot **
619 temp_slots_at_level (int level)
621 if (level >= (int) vec_safe_length (used_temp_slots))
622 vec_safe_grow_cleared (used_temp_slots, level + 1);
624 return &(*used_temp_slots)[level];
627 /* Returns the maximal temporary slot level. */
629 static int
630 max_slot_level (void)
632 if (!used_temp_slots)
633 return -1;
635 return used_temp_slots->length () - 1;
638 /* Moves temporary slot TEMP to LEVEL. */
640 static void
641 move_slot_to_level (struct temp_slot *temp, int level)
643 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
644 insert_slot_to_list (temp, temp_slots_at_level (level));
645 temp->level = level;
648 /* Make temporary slot TEMP available. */
650 static void
651 make_slot_available (struct temp_slot *temp)
653 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
654 insert_slot_to_list (temp, &avail_temp_slots);
655 temp->in_use = 0;
656 temp->level = -1;
657 n_temp_slots_in_use--;
660 /* Compute the hash value for an address -> temp slot mapping.
661 The value is cached on the mapping entry. */
662 static hashval_t
663 temp_slot_address_compute_hash (struct temp_slot_address_entry *t)
665 int do_not_record = 0;
666 return hash_rtx (t->address, GET_MODE (t->address),
667 &do_not_record, NULL, false);
670 /* Return the hash value for an address -> temp slot mapping. */
671 hashval_t
672 temp_address_hasher::hash (temp_slot_address_entry *t)
674 return t->hash;
677 /* Compare two address -> temp slot mapping entries. */
678 bool
679 temp_address_hasher::equal (temp_slot_address_entry *t1,
680 temp_slot_address_entry *t2)
682 return exp_equiv_p (t1->address, t2->address, 0, true);
685 /* Add ADDRESS as an alias of TEMP_SLOT to the addess -> temp slot mapping. */
686 static void
687 insert_temp_slot_address (rtx address, struct temp_slot *temp_slot)
689 struct temp_slot_address_entry *t = ggc_alloc<temp_slot_address_entry> ();
690 t->address = address;
691 t->temp_slot = temp_slot;
692 t->hash = temp_slot_address_compute_hash (t);
693 *temp_slot_address_table->find_slot_with_hash (t, t->hash, INSERT) = t;
696 /* Remove an address -> temp slot mapping entry if the temp slot is
697 not in use anymore. Callback for remove_unused_temp_slot_addresses. */
699 remove_unused_temp_slot_addresses_1 (temp_slot_address_entry **slot, void *)
701 const struct temp_slot_address_entry *t = *slot;
702 if (! t->temp_slot->in_use)
703 temp_slot_address_table->clear_slot (slot);
704 return 1;
707 /* Remove all mappings of addresses to unused temp slots. */
708 static void
709 remove_unused_temp_slot_addresses (void)
711 /* Use quicker clearing if there aren't any active temp slots. */
712 if (n_temp_slots_in_use)
713 temp_slot_address_table->traverse
714 <void *, remove_unused_temp_slot_addresses_1> (NULL);
715 else
716 temp_slot_address_table->empty ();
719 /* Find the temp slot corresponding to the object at address X. */
721 static struct temp_slot *
722 find_temp_slot_from_address (rtx x)
724 struct temp_slot *p;
725 struct temp_slot_address_entry tmp, *t;
727 /* First try the easy way:
728 See if X exists in the address -> temp slot mapping. */
729 tmp.address = x;
730 tmp.temp_slot = NULL;
731 tmp.hash = temp_slot_address_compute_hash (&tmp);
732 t = temp_slot_address_table->find_with_hash (&tmp, tmp.hash);
733 if (t)
734 return t->temp_slot;
736 /* If we have a sum involving a register, see if it points to a temp
737 slot. */
738 if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 0))
739 && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
740 return p;
741 else if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 1))
742 && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
743 return p;
745 /* Last resort: Address is a virtual stack var address. */
746 if (GET_CODE (x) == PLUS
747 && XEXP (x, 0) == virtual_stack_vars_rtx
748 && CONST_INT_P (XEXP (x, 1)))
750 int i;
751 for (i = max_slot_level (); i >= 0; i--)
752 for (p = *temp_slots_at_level (i); p; p = p->next)
754 if (INTVAL (XEXP (x, 1)) >= p->base_offset
755 && INTVAL (XEXP (x, 1)) < p->base_offset + p->full_size)
756 return p;
760 return NULL;
763 /* Allocate a temporary stack slot and record it for possible later
764 reuse.
766 MODE is the machine mode to be given to the returned rtx.
768 SIZE is the size in units of the space required. We do no rounding here
769 since assign_stack_local will do any required rounding.
771 TYPE is the type that will be used for the stack slot. */
774 assign_stack_temp_for_type (machine_mode mode, HOST_WIDE_INT size,
775 tree type)
777 unsigned int align;
778 struct temp_slot *p, *best_p = 0, *selected = NULL, **pp;
779 rtx slot;
781 /* If SIZE is -1 it means that somebody tried to allocate a temporary
782 of a variable size. */
783 gcc_assert (size != -1);
785 align = get_stack_local_alignment (type, mode);
787 /* Try to find an available, already-allocated temporary of the proper
788 mode which meets the size and alignment requirements. Choose the
789 smallest one with the closest alignment.
791 If assign_stack_temp is called outside of the tree->rtl expansion,
792 we cannot reuse the stack slots (that may still refer to
793 VIRTUAL_STACK_VARS_REGNUM). */
794 if (!virtuals_instantiated)
796 for (p = avail_temp_slots; p; p = p->next)
798 if (p->align >= align && p->size >= size
799 && GET_MODE (p->slot) == mode
800 && objects_must_conflict_p (p->type, type)
801 && (best_p == 0 || best_p->size > p->size
802 || (best_p->size == p->size && best_p->align > p->align)))
804 if (p->align == align && p->size == size)
806 selected = p;
807 cut_slot_from_list (selected, &avail_temp_slots);
808 best_p = 0;
809 break;
811 best_p = p;
816 /* Make our best, if any, the one to use. */
817 if (best_p)
819 selected = best_p;
820 cut_slot_from_list (selected, &avail_temp_slots);
822 /* If there are enough aligned bytes left over, make them into a new
823 temp_slot so that the extra bytes don't get wasted. Do this only
824 for BLKmode slots, so that we can be sure of the alignment. */
825 if (GET_MODE (best_p->slot) == BLKmode)
827 int alignment = best_p->align / BITS_PER_UNIT;
828 HOST_WIDE_INT rounded_size = CEIL_ROUND (size, alignment);
830 if (best_p->size - rounded_size >= alignment)
832 p = ggc_alloc<temp_slot> ();
833 p->in_use = 0;
834 p->size = best_p->size - rounded_size;
835 p->base_offset = best_p->base_offset + rounded_size;
836 p->full_size = best_p->full_size - rounded_size;
837 p->slot = adjust_address_nv (best_p->slot, BLKmode, rounded_size);
838 p->align = best_p->align;
839 p->type = best_p->type;
840 insert_slot_to_list (p, &avail_temp_slots);
842 vec_safe_push (stack_slot_list, p->slot);
844 best_p->size = rounded_size;
845 best_p->full_size = rounded_size;
850 /* If we still didn't find one, make a new temporary. */
851 if (selected == 0)
853 HOST_WIDE_INT frame_offset_old = frame_offset;
855 p = ggc_alloc<temp_slot> ();
857 /* We are passing an explicit alignment request to assign_stack_local.
858 One side effect of that is assign_stack_local will not round SIZE
859 to ensure the frame offset remains suitably aligned.
861 So for requests which depended on the rounding of SIZE, we go ahead
862 and round it now. We also make sure ALIGNMENT is at least
863 BIGGEST_ALIGNMENT. */
864 gcc_assert (mode != BLKmode || align == BIGGEST_ALIGNMENT);
865 p->slot = assign_stack_local_1 (mode,
866 (mode == BLKmode
867 ? CEIL_ROUND (size,
868 (int) align
869 / BITS_PER_UNIT)
870 : size),
871 align, 0);
873 p->align = align;
875 /* The following slot size computation is necessary because we don't
876 know the actual size of the temporary slot until assign_stack_local
877 has performed all the frame alignment and size rounding for the
878 requested temporary. Note that extra space added for alignment
879 can be either above or below this stack slot depending on which
880 way the frame grows. We include the extra space if and only if it
881 is above this slot. */
882 if (FRAME_GROWS_DOWNWARD)
883 p->size = frame_offset_old - frame_offset;
884 else
885 p->size = size;
887 /* Now define the fields used by combine_temp_slots. */
888 if (FRAME_GROWS_DOWNWARD)
890 p->base_offset = frame_offset;
891 p->full_size = frame_offset_old - frame_offset;
893 else
895 p->base_offset = frame_offset_old;
896 p->full_size = frame_offset - frame_offset_old;
899 selected = p;
902 p = selected;
903 p->in_use = 1;
904 p->type = type;
905 p->level = temp_slot_level;
906 n_temp_slots_in_use++;
908 pp = temp_slots_at_level (p->level);
909 insert_slot_to_list (p, pp);
910 insert_temp_slot_address (XEXP (p->slot, 0), p);
912 /* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
913 slot = gen_rtx_MEM (mode, XEXP (p->slot, 0));
914 vec_safe_push (stack_slot_list, slot);
916 /* If we know the alias set for the memory that will be used, use
917 it. If there's no TYPE, then we don't know anything about the
918 alias set for the memory. */
919 set_mem_alias_set (slot, type ? get_alias_set (type) : 0);
920 set_mem_align (slot, align);
922 /* If a type is specified, set the relevant flags. */
923 if (type != 0)
924 MEM_VOLATILE_P (slot) = TYPE_VOLATILE (type);
925 MEM_NOTRAP_P (slot) = 1;
927 return slot;
930 /* Allocate a temporary stack slot and record it for possible later
931 reuse. First two arguments are same as in preceding function. */
934 assign_stack_temp (machine_mode mode, HOST_WIDE_INT size)
936 return assign_stack_temp_for_type (mode, size, NULL_TREE);
939 /* Assign a temporary.
940 If TYPE_OR_DECL is a decl, then we are doing it on behalf of the decl
941 and so that should be used in error messages. In either case, we
942 allocate of the given type.
943 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
944 it is 0 if a register is OK.
945 DONT_PROMOTE is 1 if we should not promote values in register
946 to wider modes. */
949 assign_temp (tree type_or_decl, int memory_required,
950 int dont_promote ATTRIBUTE_UNUSED)
952 tree type, decl;
953 machine_mode mode;
954 #ifdef PROMOTE_MODE
955 int unsignedp;
956 #endif
958 if (DECL_P (type_or_decl))
959 decl = type_or_decl, type = TREE_TYPE (decl);
960 else
961 decl = NULL, type = type_or_decl;
963 mode = TYPE_MODE (type);
964 #ifdef PROMOTE_MODE
965 unsignedp = TYPE_UNSIGNED (type);
966 #endif
968 /* Allocating temporaries of TREE_ADDRESSABLE type must be done in the front
969 end. See also create_tmp_var for the gimplification-time check. */
970 gcc_assert (!TREE_ADDRESSABLE (type) && COMPLETE_TYPE_P (type));
972 if (mode == BLKmode || memory_required)
974 HOST_WIDE_INT size = int_size_in_bytes (type);
975 rtx tmp;
977 /* Zero sized arrays are GNU C extension. Set size to 1 to avoid
978 problems with allocating the stack space. */
979 if (size == 0)
980 size = 1;
982 /* Unfortunately, we don't yet know how to allocate variable-sized
983 temporaries. However, sometimes we can find a fixed upper limit on
984 the size, so try that instead. */
985 else if (size == -1)
986 size = max_int_size_in_bytes (type);
988 /* The size of the temporary may be too large to fit into an integer. */
989 /* ??? Not sure this should happen except for user silliness, so limit
990 this to things that aren't compiler-generated temporaries. The
991 rest of the time we'll die in assign_stack_temp_for_type. */
992 if (decl && size == -1
993 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST)
995 error ("size of variable %q+D is too large", decl);
996 size = 1;
999 tmp = assign_stack_temp_for_type (mode, size, type);
1000 return tmp;
1003 #ifdef PROMOTE_MODE
1004 if (! dont_promote)
1005 mode = promote_mode (type, mode, &unsignedp);
1006 #endif
1008 return gen_reg_rtx (mode);
1011 /* Combine temporary stack slots which are adjacent on the stack.
1013 This allows for better use of already allocated stack space. This is only
1014 done for BLKmode slots because we can be sure that we won't have alignment
1015 problems in this case. */
1017 static void
1018 combine_temp_slots (void)
1020 struct temp_slot *p, *q, *next, *next_q;
1021 int num_slots;
1023 /* We can't combine slots, because the information about which slot
1024 is in which alias set will be lost. */
1025 if (flag_strict_aliasing)
1026 return;
1028 /* If there are a lot of temp slots, don't do anything unless
1029 high levels of optimization. */
1030 if (! flag_expensive_optimizations)
1031 for (p = avail_temp_slots, num_slots = 0; p; p = p->next, num_slots++)
1032 if (num_slots > 100 || (num_slots > 10 && optimize == 0))
1033 return;
1035 for (p = avail_temp_slots; p; p = next)
1037 int delete_p = 0;
1039 next = p->next;
1041 if (GET_MODE (p->slot) != BLKmode)
1042 continue;
1044 for (q = p->next; q; q = next_q)
1046 int delete_q = 0;
1048 next_q = q->next;
1050 if (GET_MODE (q->slot) != BLKmode)
1051 continue;
1053 if (p->base_offset + p->full_size == q->base_offset)
1055 /* Q comes after P; combine Q into P. */
1056 p->size += q->size;
1057 p->full_size += q->full_size;
1058 delete_q = 1;
1060 else if (q->base_offset + q->full_size == p->base_offset)
1062 /* P comes after Q; combine P into Q. */
1063 q->size += p->size;
1064 q->full_size += p->full_size;
1065 delete_p = 1;
1066 break;
1068 if (delete_q)
1069 cut_slot_from_list (q, &avail_temp_slots);
1072 /* Either delete P or advance past it. */
1073 if (delete_p)
1074 cut_slot_from_list (p, &avail_temp_slots);
1078 /* Indicate that NEW_RTX is an alternate way of referring to the temp
1079 slot that previously was known by OLD_RTX. */
1081 void
1082 update_temp_slot_address (rtx old_rtx, rtx new_rtx)
1084 struct temp_slot *p;
1086 if (rtx_equal_p (old_rtx, new_rtx))
1087 return;
1089 p = find_temp_slot_from_address (old_rtx);
1091 /* If we didn't find one, see if both OLD_RTX is a PLUS. If so, and
1092 NEW_RTX is a register, see if one operand of the PLUS is a
1093 temporary location. If so, NEW_RTX points into it. Otherwise,
1094 if both OLD_RTX and NEW_RTX are a PLUS and if there is a register
1095 in common between them. If so, try a recursive call on those
1096 values. */
1097 if (p == 0)
1099 if (GET_CODE (old_rtx) != PLUS)
1100 return;
1102 if (REG_P (new_rtx))
1104 update_temp_slot_address (XEXP (old_rtx, 0), new_rtx);
1105 update_temp_slot_address (XEXP (old_rtx, 1), new_rtx);
1106 return;
1108 else if (GET_CODE (new_rtx) != PLUS)
1109 return;
1111 if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 0)))
1112 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 1));
1113 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 0)))
1114 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 1));
1115 else if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 1)))
1116 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 0));
1117 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 1)))
1118 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 0));
1120 return;
1123 /* Otherwise add an alias for the temp's address. */
1124 insert_temp_slot_address (new_rtx, p);
1127 /* If X could be a reference to a temporary slot, mark that slot as
1128 belonging to the to one level higher than the current level. If X
1129 matched one of our slots, just mark that one. Otherwise, we can't
1130 easily predict which it is, so upgrade all of them.
1132 This is called when an ({...}) construct occurs and a statement
1133 returns a value in memory. */
1135 void
1136 preserve_temp_slots (rtx x)
1138 struct temp_slot *p = 0, *next;
1140 if (x == 0)
1141 return;
1143 /* If X is a register that is being used as a pointer, see if we have
1144 a temporary slot we know it points to. */
1145 if (REG_P (x) && REG_POINTER (x))
1146 p = find_temp_slot_from_address (x);
1148 /* If X is not in memory or is at a constant address, it cannot be in
1149 a temporary slot. */
1150 if (p == 0 && (!MEM_P (x) || CONSTANT_P (XEXP (x, 0))))
1151 return;
1153 /* First see if we can find a match. */
1154 if (p == 0)
1155 p = find_temp_slot_from_address (XEXP (x, 0));
1157 if (p != 0)
1159 if (p->level == temp_slot_level)
1160 move_slot_to_level (p, temp_slot_level - 1);
1161 return;
1164 /* Otherwise, preserve all non-kept slots at this level. */
1165 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1167 next = p->next;
1168 move_slot_to_level (p, temp_slot_level - 1);
1172 /* Free all temporaries used so far. This is normally called at the
1173 end of generating code for a statement. */
1175 void
1176 free_temp_slots (void)
1178 struct temp_slot *p, *next;
1179 bool some_available = false;
1181 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1183 next = p->next;
1184 make_slot_available (p);
1185 some_available = true;
1188 if (some_available)
1190 remove_unused_temp_slot_addresses ();
1191 combine_temp_slots ();
1195 /* Push deeper into the nesting level for stack temporaries. */
1197 void
1198 push_temp_slots (void)
1200 temp_slot_level++;
1203 /* Pop a temporary nesting level. All slots in use in the current level
1204 are freed. */
1206 void
1207 pop_temp_slots (void)
1209 free_temp_slots ();
1210 temp_slot_level--;
1213 /* Initialize temporary slots. */
1215 void
1216 init_temp_slots (void)
1218 /* We have not allocated any temporaries yet. */
1219 avail_temp_slots = 0;
1220 vec_alloc (used_temp_slots, 0);
1221 temp_slot_level = 0;
1222 n_temp_slots_in_use = 0;
1224 /* Set up the table to map addresses to temp slots. */
1225 if (! temp_slot_address_table)
1226 temp_slot_address_table = hash_table<temp_address_hasher>::create_ggc (32);
1227 else
1228 temp_slot_address_table->empty ();
1231 /* Functions and data structures to keep track of the values hard regs
1232 had at the start of the function. */
1234 /* Private type used by get_hard_reg_initial_reg, get_hard_reg_initial_val,
1235 and has_hard_reg_initial_val.. */
1236 struct GTY(()) initial_value_pair {
1237 rtx hard_reg;
1238 rtx pseudo;
1240 /* ??? This could be a VEC but there is currently no way to define an
1241 opaque VEC type. This could be worked around by defining struct
1242 initial_value_pair in function.h. */
1243 struct GTY(()) initial_value_struct {
1244 int num_entries;
1245 int max_entries;
1246 initial_value_pair * GTY ((length ("%h.num_entries"))) entries;
1249 /* If a pseudo represents an initial hard reg (or expression), return
1250 it, else return NULL_RTX. */
1253 get_hard_reg_initial_reg (rtx reg)
1255 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1256 int i;
1258 if (ivs == 0)
1259 return NULL_RTX;
1261 for (i = 0; i < ivs->num_entries; i++)
1262 if (rtx_equal_p (ivs->entries[i].pseudo, reg))
1263 return ivs->entries[i].hard_reg;
1265 return NULL_RTX;
1268 /* Make sure that there's a pseudo register of mode MODE that stores the
1269 initial value of hard register REGNO. Return an rtx for such a pseudo. */
1272 get_hard_reg_initial_val (machine_mode mode, unsigned int regno)
1274 struct initial_value_struct *ivs;
1275 rtx rv;
1277 rv = has_hard_reg_initial_val (mode, regno);
1278 if (rv)
1279 return rv;
1281 ivs = crtl->hard_reg_initial_vals;
1282 if (ivs == 0)
1284 ivs = ggc_alloc<initial_value_struct> ();
1285 ivs->num_entries = 0;
1286 ivs->max_entries = 5;
1287 ivs->entries = ggc_vec_alloc<initial_value_pair> (5);
1288 crtl->hard_reg_initial_vals = ivs;
1291 if (ivs->num_entries >= ivs->max_entries)
1293 ivs->max_entries += 5;
1294 ivs->entries = GGC_RESIZEVEC (initial_value_pair, ivs->entries,
1295 ivs->max_entries);
1298 ivs->entries[ivs->num_entries].hard_reg = gen_rtx_REG (mode, regno);
1299 ivs->entries[ivs->num_entries].pseudo = gen_reg_rtx (mode);
1301 return ivs->entries[ivs->num_entries++].pseudo;
1304 /* See if get_hard_reg_initial_val has been used to create a pseudo
1305 for the initial value of hard register REGNO in mode MODE. Return
1306 the associated pseudo if so, otherwise return NULL. */
1309 has_hard_reg_initial_val (machine_mode mode, unsigned int regno)
1311 struct initial_value_struct *ivs;
1312 int i;
1314 ivs = crtl->hard_reg_initial_vals;
1315 if (ivs != 0)
1316 for (i = 0; i < ivs->num_entries; i++)
1317 if (GET_MODE (ivs->entries[i].hard_reg) == mode
1318 && REGNO (ivs->entries[i].hard_reg) == regno)
1319 return ivs->entries[i].pseudo;
1321 return NULL_RTX;
1324 unsigned int
1325 emit_initial_value_sets (void)
1327 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1328 int i;
1329 rtx_insn *seq;
1331 if (ivs == 0)
1332 return 0;
1334 start_sequence ();
1335 for (i = 0; i < ivs->num_entries; i++)
1336 emit_move_insn (ivs->entries[i].pseudo, ivs->entries[i].hard_reg);
1337 seq = get_insns ();
1338 end_sequence ();
1340 emit_insn_at_entry (seq);
1341 return 0;
1344 /* Return the hardreg-pseudoreg initial values pair entry I and
1345 TRUE if I is a valid entry, or FALSE if I is not a valid entry. */
1346 bool
1347 initial_value_entry (int i, rtx *hreg, rtx *preg)
1349 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1350 if (!ivs || i >= ivs->num_entries)
1351 return false;
1353 *hreg = ivs->entries[i].hard_reg;
1354 *preg = ivs->entries[i].pseudo;
1355 return true;
1358 /* These routines are responsible for converting virtual register references
1359 to the actual hard register references once RTL generation is complete.
1361 The following four variables are used for communication between the
1362 routines. They contain the offsets of the virtual registers from their
1363 respective hard registers. */
1365 static int in_arg_offset;
1366 static int var_offset;
1367 static int dynamic_offset;
1368 static int out_arg_offset;
1369 static int cfa_offset;
1371 /* In most machines, the stack pointer register is equivalent to the bottom
1372 of the stack. */
1374 #ifndef STACK_POINTER_OFFSET
1375 #define STACK_POINTER_OFFSET 0
1376 #endif
1378 #if defined (REG_PARM_STACK_SPACE) && !defined (INCOMING_REG_PARM_STACK_SPACE)
1379 #define INCOMING_REG_PARM_STACK_SPACE REG_PARM_STACK_SPACE
1380 #endif
1382 /* If not defined, pick an appropriate default for the offset of dynamically
1383 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
1384 INCOMING_REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
1386 #ifndef STACK_DYNAMIC_OFFSET
1388 /* The bottom of the stack points to the actual arguments. If
1389 REG_PARM_STACK_SPACE is defined, this includes the space for the register
1390 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
1391 stack space for register parameters is not pushed by the caller, but
1392 rather part of the fixed stack areas and hence not included in
1393 `crtl->outgoing_args_size'. Nevertheless, we must allow
1394 for it when allocating stack dynamic objects. */
1396 #ifdef INCOMING_REG_PARM_STACK_SPACE
1397 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1398 ((ACCUMULATE_OUTGOING_ARGS \
1399 ? (crtl->outgoing_args_size \
1400 + (OUTGOING_REG_PARM_STACK_SPACE ((!(FNDECL) ? NULL_TREE : TREE_TYPE (FNDECL))) ? 0 \
1401 : INCOMING_REG_PARM_STACK_SPACE (FNDECL))) \
1402 : 0) + (STACK_POINTER_OFFSET))
1403 #else
1404 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1405 ((ACCUMULATE_OUTGOING_ARGS ? crtl->outgoing_args_size : 0) \
1406 + (STACK_POINTER_OFFSET))
1407 #endif
1408 #endif
1411 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
1412 is a virtual register, return the equivalent hard register and set the
1413 offset indirectly through the pointer. Otherwise, return 0. */
1415 static rtx
1416 instantiate_new_reg (rtx x, HOST_WIDE_INT *poffset)
1418 rtx new_rtx;
1419 HOST_WIDE_INT offset;
1421 if (x == virtual_incoming_args_rtx)
1423 if (stack_realign_drap)
1425 /* Replace virtual_incoming_args_rtx with internal arg
1426 pointer if DRAP is used to realign stack. */
1427 new_rtx = crtl->args.internal_arg_pointer;
1428 offset = 0;
1430 else
1431 new_rtx = arg_pointer_rtx, offset = in_arg_offset;
1433 else if (x == virtual_stack_vars_rtx)
1434 new_rtx = frame_pointer_rtx, offset = var_offset;
1435 else if (x == virtual_stack_dynamic_rtx)
1436 new_rtx = stack_pointer_rtx, offset = dynamic_offset;
1437 else if (x == virtual_outgoing_args_rtx)
1438 new_rtx = stack_pointer_rtx, offset = out_arg_offset;
1439 else if (x == virtual_cfa_rtx)
1441 #ifdef FRAME_POINTER_CFA_OFFSET
1442 new_rtx = frame_pointer_rtx;
1443 #else
1444 new_rtx = arg_pointer_rtx;
1445 #endif
1446 offset = cfa_offset;
1448 else if (x == virtual_preferred_stack_boundary_rtx)
1450 new_rtx = GEN_INT (crtl->preferred_stack_boundary / BITS_PER_UNIT);
1451 offset = 0;
1453 else
1454 return NULL_RTX;
1456 *poffset = offset;
1457 return new_rtx;
1460 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1461 registers present inside of *LOC. The expression is simplified,
1462 as much as possible, but is not to be considered "valid" in any sense
1463 implied by the target. Return true if any change is made. */
1465 static bool
1466 instantiate_virtual_regs_in_rtx (rtx *loc)
1468 if (!*loc)
1469 return false;
1470 bool changed = false;
1471 subrtx_ptr_iterator::array_type array;
1472 FOR_EACH_SUBRTX_PTR (iter, array, loc, NONCONST)
1474 rtx *loc = *iter;
1475 if (rtx x = *loc)
1477 rtx new_rtx;
1478 HOST_WIDE_INT offset;
1479 switch (GET_CODE (x))
1481 case REG:
1482 new_rtx = instantiate_new_reg (x, &offset);
1483 if (new_rtx)
1485 *loc = plus_constant (GET_MODE (x), new_rtx, offset);
1486 changed = true;
1488 iter.skip_subrtxes ();
1489 break;
1491 case PLUS:
1492 new_rtx = instantiate_new_reg (XEXP (x, 0), &offset);
1493 if (new_rtx)
1495 XEXP (x, 0) = new_rtx;
1496 *loc = plus_constant (GET_MODE (x), x, offset, true);
1497 changed = true;
1498 iter.skip_subrtxes ();
1499 break;
1502 /* FIXME -- from old code */
1503 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
1504 we can commute the PLUS and SUBREG because pointers into the
1505 frame are well-behaved. */
1506 break;
1508 default:
1509 break;
1513 return changed;
1516 /* A subroutine of instantiate_virtual_regs_in_insn. Return true if X
1517 matches the predicate for insn CODE operand OPERAND. */
1519 static int
1520 safe_insn_predicate (int code, int operand, rtx x)
1522 return code < 0 || insn_operand_matches ((enum insn_code) code, operand, x);
1525 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1526 registers present inside of insn. The result will be a valid insn. */
1528 static void
1529 instantiate_virtual_regs_in_insn (rtx_insn *insn)
1531 HOST_WIDE_INT offset;
1532 int insn_code, i;
1533 bool any_change = false;
1534 rtx set, new_rtx, x;
1535 rtx_insn *seq;
1537 /* There are some special cases to be handled first. */
1538 set = single_set (insn);
1539 if (set)
1541 /* We're allowed to assign to a virtual register. This is interpreted
1542 to mean that the underlying register gets assigned the inverse
1543 transformation. This is used, for example, in the handling of
1544 non-local gotos. */
1545 new_rtx = instantiate_new_reg (SET_DEST (set), &offset);
1546 if (new_rtx)
1548 start_sequence ();
1550 instantiate_virtual_regs_in_rtx (&SET_SRC (set));
1551 x = simplify_gen_binary (PLUS, GET_MODE (new_rtx), SET_SRC (set),
1552 gen_int_mode (-offset, GET_MODE (new_rtx)));
1553 x = force_operand (x, new_rtx);
1554 if (x != new_rtx)
1555 emit_move_insn (new_rtx, x);
1557 seq = get_insns ();
1558 end_sequence ();
1560 emit_insn_before (seq, insn);
1561 delete_insn (insn);
1562 return;
1565 /* Handle a straight copy from a virtual register by generating a
1566 new add insn. The difference between this and falling through
1567 to the generic case is avoiding a new pseudo and eliminating a
1568 move insn in the initial rtl stream. */
1569 new_rtx = instantiate_new_reg (SET_SRC (set), &offset);
1570 if (new_rtx && offset != 0
1571 && REG_P (SET_DEST (set))
1572 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1574 start_sequence ();
1576 x = expand_simple_binop (GET_MODE (SET_DEST (set)), PLUS, new_rtx,
1577 gen_int_mode (offset,
1578 GET_MODE (SET_DEST (set))),
1579 SET_DEST (set), 1, OPTAB_LIB_WIDEN);
1580 if (x != SET_DEST (set))
1581 emit_move_insn (SET_DEST (set), x);
1583 seq = get_insns ();
1584 end_sequence ();
1586 emit_insn_before (seq, insn);
1587 delete_insn (insn);
1588 return;
1591 extract_insn (insn);
1592 insn_code = INSN_CODE (insn);
1594 /* Handle a plus involving a virtual register by determining if the
1595 operands remain valid if they're modified in place. */
1596 if (GET_CODE (SET_SRC (set)) == PLUS
1597 && recog_data.n_operands >= 3
1598 && recog_data.operand_loc[1] == &XEXP (SET_SRC (set), 0)
1599 && recog_data.operand_loc[2] == &XEXP (SET_SRC (set), 1)
1600 && CONST_INT_P (recog_data.operand[2])
1601 && (new_rtx = instantiate_new_reg (recog_data.operand[1], &offset)))
1603 offset += INTVAL (recog_data.operand[2]);
1605 /* If the sum is zero, then replace with a plain move. */
1606 if (offset == 0
1607 && REG_P (SET_DEST (set))
1608 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1610 start_sequence ();
1611 emit_move_insn (SET_DEST (set), new_rtx);
1612 seq = get_insns ();
1613 end_sequence ();
1615 emit_insn_before (seq, insn);
1616 delete_insn (insn);
1617 return;
1620 x = gen_int_mode (offset, recog_data.operand_mode[2]);
1622 /* Using validate_change and apply_change_group here leaves
1623 recog_data in an invalid state. Since we know exactly what
1624 we want to check, do those two by hand. */
1625 if (safe_insn_predicate (insn_code, 1, new_rtx)
1626 && safe_insn_predicate (insn_code, 2, x))
1628 *recog_data.operand_loc[1] = recog_data.operand[1] = new_rtx;
1629 *recog_data.operand_loc[2] = recog_data.operand[2] = x;
1630 any_change = true;
1632 /* Fall through into the regular operand fixup loop in
1633 order to take care of operands other than 1 and 2. */
1637 else
1639 extract_insn (insn);
1640 insn_code = INSN_CODE (insn);
1643 /* In the general case, we expect virtual registers to appear only in
1644 operands, and then only as either bare registers or inside memories. */
1645 for (i = 0; i < recog_data.n_operands; ++i)
1647 x = recog_data.operand[i];
1648 switch (GET_CODE (x))
1650 case MEM:
1652 rtx addr = XEXP (x, 0);
1654 if (!instantiate_virtual_regs_in_rtx (&addr))
1655 continue;
1657 start_sequence ();
1658 x = replace_equiv_address (x, addr, true);
1659 /* It may happen that the address with the virtual reg
1660 was valid (e.g. based on the virtual stack reg, which might
1661 be acceptable to the predicates with all offsets), whereas
1662 the address now isn't anymore, for instance when the address
1663 is still offsetted, but the base reg isn't virtual-stack-reg
1664 anymore. Below we would do a force_reg on the whole operand,
1665 but this insn might actually only accept memory. Hence,
1666 before doing that last resort, try to reload the address into
1667 a register, so this operand stays a MEM. */
1668 if (!safe_insn_predicate (insn_code, i, x))
1670 addr = force_reg (GET_MODE (addr), addr);
1671 x = replace_equiv_address (x, addr, true);
1673 seq = get_insns ();
1674 end_sequence ();
1675 if (seq)
1676 emit_insn_before (seq, insn);
1678 break;
1680 case REG:
1681 new_rtx = instantiate_new_reg (x, &offset);
1682 if (new_rtx == NULL)
1683 continue;
1684 if (offset == 0)
1685 x = new_rtx;
1686 else
1688 start_sequence ();
1690 /* Careful, special mode predicates may have stuff in
1691 insn_data[insn_code].operand[i].mode that isn't useful
1692 to us for computing a new value. */
1693 /* ??? Recognize address_operand and/or "p" constraints
1694 to see if (plus new offset) is a valid before we put
1695 this through expand_simple_binop. */
1696 x = expand_simple_binop (GET_MODE (x), PLUS, new_rtx,
1697 gen_int_mode (offset, GET_MODE (x)),
1698 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1699 seq = get_insns ();
1700 end_sequence ();
1701 emit_insn_before (seq, insn);
1703 break;
1705 case SUBREG:
1706 new_rtx = instantiate_new_reg (SUBREG_REG (x), &offset);
1707 if (new_rtx == NULL)
1708 continue;
1709 if (offset != 0)
1711 start_sequence ();
1712 new_rtx = expand_simple_binop
1713 (GET_MODE (new_rtx), PLUS, new_rtx,
1714 gen_int_mode (offset, GET_MODE (new_rtx)),
1715 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1716 seq = get_insns ();
1717 end_sequence ();
1718 emit_insn_before (seq, insn);
1720 x = simplify_gen_subreg (recog_data.operand_mode[i], new_rtx,
1721 GET_MODE (new_rtx), SUBREG_BYTE (x));
1722 gcc_assert (x);
1723 break;
1725 default:
1726 continue;
1729 /* At this point, X contains the new value for the operand.
1730 Validate the new value vs the insn predicate. Note that
1731 asm insns will have insn_code -1 here. */
1732 if (!safe_insn_predicate (insn_code, i, x))
1734 start_sequence ();
1735 if (REG_P (x))
1737 gcc_assert (REGNO (x) <= LAST_VIRTUAL_REGISTER);
1738 x = copy_to_reg (x);
1740 else
1741 x = force_reg (insn_data[insn_code].operand[i].mode, x);
1742 seq = get_insns ();
1743 end_sequence ();
1744 if (seq)
1745 emit_insn_before (seq, insn);
1748 *recog_data.operand_loc[i] = recog_data.operand[i] = x;
1749 any_change = true;
1752 if (any_change)
1754 /* Propagate operand changes into the duplicates. */
1755 for (i = 0; i < recog_data.n_dups; ++i)
1756 *recog_data.dup_loc[i]
1757 = copy_rtx (recog_data.operand[(unsigned)recog_data.dup_num[i]]);
1759 /* Force re-recognition of the instruction for validation. */
1760 INSN_CODE (insn) = -1;
1763 if (asm_noperands (PATTERN (insn)) >= 0)
1765 if (!check_asm_operands (PATTERN (insn)))
1767 error_for_asm (insn, "impossible constraint in %<asm%>");
1768 /* For asm goto, instead of fixing up all the edges
1769 just clear the template and clear input operands
1770 (asm goto doesn't have any output operands). */
1771 if (JUMP_P (insn))
1773 rtx asm_op = extract_asm_operands (PATTERN (insn));
1774 ASM_OPERANDS_TEMPLATE (asm_op) = ggc_strdup ("");
1775 ASM_OPERANDS_INPUT_VEC (asm_op) = rtvec_alloc (0);
1776 ASM_OPERANDS_INPUT_CONSTRAINT_VEC (asm_op) = rtvec_alloc (0);
1778 else
1779 delete_insn (insn);
1782 else
1784 if (recog_memoized (insn) < 0)
1785 fatal_insn_not_found (insn);
1789 /* Subroutine of instantiate_decls. Given RTL representing a decl,
1790 do any instantiation required. */
1792 void
1793 instantiate_decl_rtl (rtx x)
1795 rtx addr;
1797 if (x == 0)
1798 return;
1800 /* If this is a CONCAT, recurse for the pieces. */
1801 if (GET_CODE (x) == CONCAT)
1803 instantiate_decl_rtl (XEXP (x, 0));
1804 instantiate_decl_rtl (XEXP (x, 1));
1805 return;
1808 /* If this is not a MEM, no need to do anything. Similarly if the
1809 address is a constant or a register that is not a virtual register. */
1810 if (!MEM_P (x))
1811 return;
1813 addr = XEXP (x, 0);
1814 if (CONSTANT_P (addr)
1815 || (REG_P (addr)
1816 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
1817 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
1818 return;
1820 instantiate_virtual_regs_in_rtx (&XEXP (x, 0));
1823 /* Helper for instantiate_decls called via walk_tree: Process all decls
1824 in the given DECL_VALUE_EXPR. */
1826 static tree
1827 instantiate_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1829 tree t = *tp;
1830 if (! EXPR_P (t))
1832 *walk_subtrees = 0;
1833 if (DECL_P (t))
1835 if (DECL_RTL_SET_P (t))
1836 instantiate_decl_rtl (DECL_RTL (t));
1837 if (TREE_CODE (t) == PARM_DECL && DECL_NAMELESS (t)
1838 && DECL_INCOMING_RTL (t))
1839 instantiate_decl_rtl (DECL_INCOMING_RTL (t));
1840 if ((VAR_P (t) || TREE_CODE (t) == RESULT_DECL)
1841 && DECL_HAS_VALUE_EXPR_P (t))
1843 tree v = DECL_VALUE_EXPR (t);
1844 walk_tree (&v, instantiate_expr, NULL, NULL);
1848 return NULL;
1851 /* Subroutine of instantiate_decls: Process all decls in the given
1852 BLOCK node and all its subblocks. */
1854 static void
1855 instantiate_decls_1 (tree let)
1857 tree t;
1859 for (t = BLOCK_VARS (let); t; t = DECL_CHAIN (t))
1861 if (DECL_RTL_SET_P (t))
1862 instantiate_decl_rtl (DECL_RTL (t));
1863 if (VAR_P (t) && DECL_HAS_VALUE_EXPR_P (t))
1865 tree v = DECL_VALUE_EXPR (t);
1866 walk_tree (&v, instantiate_expr, NULL, NULL);
1870 /* Process all subblocks. */
1871 for (t = BLOCK_SUBBLOCKS (let); t; t = BLOCK_CHAIN (t))
1872 instantiate_decls_1 (t);
1875 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1876 all virtual registers in their DECL_RTL's. */
1878 static void
1879 instantiate_decls (tree fndecl)
1881 tree decl;
1882 unsigned ix;
1884 /* Process all parameters of the function. */
1885 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = DECL_CHAIN (decl))
1887 instantiate_decl_rtl (DECL_RTL (decl));
1888 instantiate_decl_rtl (DECL_INCOMING_RTL (decl));
1889 if (DECL_HAS_VALUE_EXPR_P (decl))
1891 tree v = DECL_VALUE_EXPR (decl);
1892 walk_tree (&v, instantiate_expr, NULL, NULL);
1896 if ((decl = DECL_RESULT (fndecl))
1897 && TREE_CODE (decl) == RESULT_DECL)
1899 if (DECL_RTL_SET_P (decl))
1900 instantiate_decl_rtl (DECL_RTL (decl));
1901 if (DECL_HAS_VALUE_EXPR_P (decl))
1903 tree v = DECL_VALUE_EXPR (decl);
1904 walk_tree (&v, instantiate_expr, NULL, NULL);
1908 /* Process the saved static chain if it exists. */
1909 decl = DECL_STRUCT_FUNCTION (fndecl)->static_chain_decl;
1910 if (decl && DECL_HAS_VALUE_EXPR_P (decl))
1911 instantiate_decl_rtl (DECL_RTL (DECL_VALUE_EXPR (decl)));
1913 /* Now process all variables defined in the function or its subblocks. */
1914 if (DECL_INITIAL (fndecl))
1915 instantiate_decls_1 (DECL_INITIAL (fndecl));
1917 FOR_EACH_LOCAL_DECL (cfun, ix, decl)
1918 if (DECL_RTL_SET_P (decl))
1919 instantiate_decl_rtl (DECL_RTL (decl));
1920 vec_free (cfun->local_decls);
1923 /* Pass through the INSNS of function FNDECL and convert virtual register
1924 references to hard register references. */
1926 static unsigned int
1927 instantiate_virtual_regs (void)
1929 rtx_insn *insn;
1931 /* Compute the offsets to use for this function. */
1932 in_arg_offset = FIRST_PARM_OFFSET (current_function_decl);
1933 var_offset = targetm.starting_frame_offset ();
1934 dynamic_offset = STACK_DYNAMIC_OFFSET (current_function_decl);
1935 out_arg_offset = STACK_POINTER_OFFSET;
1936 #ifdef FRAME_POINTER_CFA_OFFSET
1937 cfa_offset = FRAME_POINTER_CFA_OFFSET (current_function_decl);
1938 #else
1939 cfa_offset = ARG_POINTER_CFA_OFFSET (current_function_decl);
1940 #endif
1942 /* Initialize recognition, indicating that volatile is OK. */
1943 init_recog ();
1945 /* Scan through all the insns, instantiating every virtual register still
1946 present. */
1947 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
1948 if (INSN_P (insn))
1950 /* These patterns in the instruction stream can never be recognized.
1951 Fortunately, they shouldn't contain virtual registers either. */
1952 if (GET_CODE (PATTERN (insn)) == USE
1953 || GET_CODE (PATTERN (insn)) == CLOBBER
1954 || GET_CODE (PATTERN (insn)) == ASM_INPUT
1955 || DEBUG_MARKER_INSN_P (insn))
1956 continue;
1957 else if (DEBUG_BIND_INSN_P (insn))
1958 instantiate_virtual_regs_in_rtx (INSN_VAR_LOCATION_PTR (insn));
1959 else
1960 instantiate_virtual_regs_in_insn (insn);
1962 if (insn->deleted ())
1963 continue;
1965 instantiate_virtual_regs_in_rtx (&REG_NOTES (insn));
1967 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
1968 if (CALL_P (insn))
1969 instantiate_virtual_regs_in_rtx (&CALL_INSN_FUNCTION_USAGE (insn));
1972 /* Instantiate the virtual registers in the DECLs for debugging purposes. */
1973 instantiate_decls (current_function_decl);
1975 targetm.instantiate_decls ();
1977 /* Indicate that, from now on, assign_stack_local should use
1978 frame_pointer_rtx. */
1979 virtuals_instantiated = 1;
1981 return 0;
1984 namespace {
1986 const pass_data pass_data_instantiate_virtual_regs =
1988 RTL_PASS, /* type */
1989 "vregs", /* name */
1990 OPTGROUP_NONE, /* optinfo_flags */
1991 TV_NONE, /* tv_id */
1992 0, /* properties_required */
1993 0, /* properties_provided */
1994 0, /* properties_destroyed */
1995 0, /* todo_flags_start */
1996 0, /* todo_flags_finish */
1999 class pass_instantiate_virtual_regs : public rtl_opt_pass
2001 public:
2002 pass_instantiate_virtual_regs (gcc::context *ctxt)
2003 : rtl_opt_pass (pass_data_instantiate_virtual_regs, ctxt)
2006 /* opt_pass methods: */
2007 virtual unsigned int execute (function *)
2009 return instantiate_virtual_regs ();
2012 }; // class pass_instantiate_virtual_regs
2014 } // anon namespace
2016 rtl_opt_pass *
2017 make_pass_instantiate_virtual_regs (gcc::context *ctxt)
2019 return new pass_instantiate_virtual_regs (ctxt);
2023 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
2024 This means a type for which function calls must pass an address to the
2025 function or get an address back from the function.
2026 EXP may be a type node or an expression (whose type is tested). */
2029 aggregate_value_p (const_tree exp, const_tree fntype)
2031 const_tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
2032 int i, regno, nregs;
2033 rtx reg;
2035 if (fntype)
2036 switch (TREE_CODE (fntype))
2038 case CALL_EXPR:
2040 tree fndecl = get_callee_fndecl (fntype);
2041 if (fndecl)
2042 fntype = TREE_TYPE (fndecl);
2043 else if (CALL_EXPR_FN (fntype))
2044 fntype = TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (fntype)));
2045 else
2046 /* For internal functions, assume nothing needs to be
2047 returned in memory. */
2048 return 0;
2050 break;
2051 case FUNCTION_DECL:
2052 fntype = TREE_TYPE (fntype);
2053 break;
2054 case FUNCTION_TYPE:
2055 case METHOD_TYPE:
2056 break;
2057 case IDENTIFIER_NODE:
2058 fntype = NULL_TREE;
2059 break;
2060 default:
2061 /* We don't expect other tree types here. */
2062 gcc_unreachable ();
2065 if (VOID_TYPE_P (type))
2066 return 0;
2068 /* If a record should be passed the same as its first (and only) member
2069 don't pass it as an aggregate. */
2070 if (TREE_CODE (type) == RECORD_TYPE && TYPE_TRANSPARENT_AGGR (type))
2071 return aggregate_value_p (first_field (type), fntype);
2073 /* If the front end has decided that this needs to be passed by
2074 reference, do so. */
2075 if ((TREE_CODE (exp) == PARM_DECL || TREE_CODE (exp) == RESULT_DECL)
2076 && DECL_BY_REFERENCE (exp))
2077 return 1;
2079 /* Function types that are TREE_ADDRESSABLE force return in memory. */
2080 if (fntype && TREE_ADDRESSABLE (fntype))
2081 return 1;
2083 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
2084 and thus can't be returned in registers. */
2085 if (TREE_ADDRESSABLE (type))
2086 return 1;
2088 if (TYPE_EMPTY_P (type))
2089 return 0;
2091 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
2092 return 1;
2094 if (targetm.calls.return_in_memory (type, fntype))
2095 return 1;
2097 /* Make sure we have suitable call-clobbered regs to return
2098 the value in; if not, we must return it in memory. */
2099 reg = hard_function_value (type, 0, fntype, 0);
2101 /* If we have something other than a REG (e.g. a PARALLEL), then assume
2102 it is OK. */
2103 if (!REG_P (reg))
2104 return 0;
2106 regno = REGNO (reg);
2107 nregs = hard_regno_nregs (regno, TYPE_MODE (type));
2108 for (i = 0; i < nregs; i++)
2109 if (! call_used_regs[regno + i])
2110 return 1;
2112 return 0;
2115 /* Return true if we should assign DECL a pseudo register; false if it
2116 should live on the local stack. */
2118 bool
2119 use_register_for_decl (const_tree decl)
2121 if (TREE_CODE (decl) == SSA_NAME)
2123 /* We often try to use the SSA_NAME, instead of its underlying
2124 decl, to get type information and guide decisions, to avoid
2125 differences of behavior between anonymous and named
2126 variables, but in this one case we have to go for the actual
2127 variable if there is one. The main reason is that, at least
2128 at -O0, we want to place user variables on the stack, but we
2129 don't mind using pseudos for anonymous or ignored temps.
2130 Should we take the SSA_NAME, we'd conclude all SSA_NAMEs
2131 should go in pseudos, whereas their corresponding variables
2132 might have to go on the stack. So, disregarding the decl
2133 here would negatively impact debug info at -O0, enable
2134 coalescing between SSA_NAMEs that ought to get different
2135 stack/pseudo assignments, and get the incoming argument
2136 processing thoroughly confused by PARM_DECLs expected to live
2137 in stack slots but assigned to pseudos. */
2138 if (!SSA_NAME_VAR (decl))
2139 return TYPE_MODE (TREE_TYPE (decl)) != BLKmode
2140 && !(flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)));
2142 decl = SSA_NAME_VAR (decl);
2145 /* Honor volatile. */
2146 if (TREE_SIDE_EFFECTS (decl))
2147 return false;
2149 /* Honor addressability. */
2150 if (TREE_ADDRESSABLE (decl))
2151 return false;
2153 /* RESULT_DECLs are a bit special in that they're assigned without
2154 regard to use_register_for_decl, but we generally only store in
2155 them. If we coalesce their SSA NAMEs, we'd better return a
2156 result that matches the assignment in expand_function_start. */
2157 if (TREE_CODE (decl) == RESULT_DECL)
2159 /* If it's not an aggregate, we're going to use a REG or a
2160 PARALLEL containing a REG. */
2161 if (!aggregate_value_p (decl, current_function_decl))
2162 return true;
2164 /* If expand_function_start determines the return value, we'll
2165 use MEM if it's not by reference. */
2166 if (cfun->returns_pcc_struct
2167 || (targetm.calls.struct_value_rtx
2168 (TREE_TYPE (current_function_decl), 1)))
2169 return DECL_BY_REFERENCE (decl);
2171 /* Otherwise, we're taking an extra all.function_result_decl
2172 argument. It's set up in assign_parms_augmented_arg_list,
2173 under the (negated) conditions above, and then it's used to
2174 set up the RESULT_DECL rtl in assign_params, after looping
2175 over all parameters. Now, if the RESULT_DECL is not by
2176 reference, we'll use a MEM either way. */
2177 if (!DECL_BY_REFERENCE (decl))
2178 return false;
2180 /* Otherwise, if RESULT_DECL is DECL_BY_REFERENCE, it will take
2181 the function_result_decl's assignment. Since it's a pointer,
2182 we can short-circuit a number of the tests below, and we must
2183 duplicat e them because we don't have the
2184 function_result_decl to test. */
2185 if (!targetm.calls.allocate_stack_slots_for_args ())
2186 return true;
2187 /* We don't set DECL_IGNORED_P for the function_result_decl. */
2188 if (optimize)
2189 return true;
2190 /* We don't set DECL_REGISTER for the function_result_decl. */
2191 return false;
2194 /* Decl is implicitly addressible by bound stores and loads
2195 if it is an aggregate holding bounds. */
2196 if (chkp_function_instrumented_p (current_function_decl)
2197 && TREE_TYPE (decl)
2198 && !BOUNDED_P (decl)
2199 && chkp_type_has_pointer (TREE_TYPE (decl)))
2200 return false;
2202 /* Only register-like things go in registers. */
2203 if (DECL_MODE (decl) == BLKmode)
2204 return false;
2206 /* If -ffloat-store specified, don't put explicit float variables
2207 into registers. */
2208 /* ??? This should be checked after DECL_ARTIFICIAL, but tree-ssa
2209 propagates values across these stores, and it probably shouldn't. */
2210 if (flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)))
2211 return false;
2213 if (!targetm.calls.allocate_stack_slots_for_args ())
2214 return true;
2216 /* If we're not interested in tracking debugging information for
2217 this decl, then we can certainly put it in a register. */
2218 if (DECL_IGNORED_P (decl))
2219 return true;
2221 if (optimize)
2222 return true;
2224 if (!DECL_REGISTER (decl))
2225 return false;
2227 /* When not optimizing, disregard register keyword for types that
2228 could have methods, otherwise the methods won't be callable from
2229 the debugger. */
2230 if (RECORD_OR_UNION_TYPE_P (TREE_TYPE (decl)))
2231 return false;
2233 return true;
2236 /* Structures to communicate between the subroutines of assign_parms.
2237 The first holds data persistent across all parameters, the second
2238 is cleared out for each parameter. */
2240 struct assign_parm_data_all
2242 /* When INIT_CUMULATIVE_ARGS gets revamped, allocating CUMULATIVE_ARGS
2243 should become a job of the target or otherwise encapsulated. */
2244 CUMULATIVE_ARGS args_so_far_v;
2245 cumulative_args_t args_so_far;
2246 struct args_size stack_args_size;
2247 tree function_result_decl;
2248 tree orig_fnargs;
2249 rtx_insn *first_conversion_insn;
2250 rtx_insn *last_conversion_insn;
2251 HOST_WIDE_INT pretend_args_size;
2252 HOST_WIDE_INT extra_pretend_bytes;
2253 int reg_parm_stack_space;
2256 struct assign_parm_data_one
2258 tree nominal_type;
2259 tree passed_type;
2260 rtx entry_parm;
2261 rtx stack_parm;
2262 machine_mode nominal_mode;
2263 machine_mode passed_mode;
2264 machine_mode promoted_mode;
2265 struct locate_and_pad_arg_data locate;
2266 int partial;
2267 BOOL_BITFIELD named_arg : 1;
2268 BOOL_BITFIELD passed_pointer : 1;
2269 BOOL_BITFIELD on_stack : 1;
2270 BOOL_BITFIELD loaded_in_reg : 1;
2273 struct bounds_parm_data
2275 assign_parm_data_one parm_data;
2276 tree bounds_parm;
2277 tree ptr_parm;
2278 rtx ptr_entry;
2279 int bound_no;
2282 /* A subroutine of assign_parms. Initialize ALL. */
2284 static void
2285 assign_parms_initialize_all (struct assign_parm_data_all *all)
2287 tree fntype ATTRIBUTE_UNUSED;
2289 memset (all, 0, sizeof (*all));
2291 fntype = TREE_TYPE (current_function_decl);
2293 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
2294 INIT_CUMULATIVE_INCOMING_ARGS (all->args_so_far_v, fntype, NULL_RTX);
2295 #else
2296 INIT_CUMULATIVE_ARGS (all->args_so_far_v, fntype, NULL_RTX,
2297 current_function_decl, -1);
2298 #endif
2299 all->args_so_far = pack_cumulative_args (&all->args_so_far_v);
2301 #ifdef INCOMING_REG_PARM_STACK_SPACE
2302 all->reg_parm_stack_space
2303 = INCOMING_REG_PARM_STACK_SPACE (current_function_decl);
2304 #endif
2307 /* If ARGS contains entries with complex types, split the entry into two
2308 entries of the component type. Return a new list of substitutions are
2309 needed, else the old list. */
2311 static void
2312 split_complex_args (vec<tree> *args)
2314 unsigned i;
2315 tree p;
2317 FOR_EACH_VEC_ELT (*args, i, p)
2319 tree type = TREE_TYPE (p);
2320 if (TREE_CODE (type) == COMPLEX_TYPE
2321 && targetm.calls.split_complex_arg (type))
2323 tree decl;
2324 tree subtype = TREE_TYPE (type);
2325 bool addressable = TREE_ADDRESSABLE (p);
2327 /* Rewrite the PARM_DECL's type with its component. */
2328 p = copy_node (p);
2329 TREE_TYPE (p) = subtype;
2330 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
2331 SET_DECL_MODE (p, VOIDmode);
2332 DECL_SIZE (p) = NULL;
2333 DECL_SIZE_UNIT (p) = NULL;
2334 /* If this arg must go in memory, put it in a pseudo here.
2335 We can't allow it to go in memory as per normal parms,
2336 because the usual place might not have the imag part
2337 adjacent to the real part. */
2338 DECL_ARTIFICIAL (p) = addressable;
2339 DECL_IGNORED_P (p) = addressable;
2340 TREE_ADDRESSABLE (p) = 0;
2341 layout_decl (p, 0);
2342 (*args)[i] = p;
2344 /* Build a second synthetic decl. */
2345 decl = build_decl (EXPR_LOCATION (p),
2346 PARM_DECL, NULL_TREE, subtype);
2347 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
2348 DECL_ARTIFICIAL (decl) = addressable;
2349 DECL_IGNORED_P (decl) = addressable;
2350 layout_decl (decl, 0);
2351 args->safe_insert (++i, decl);
2356 /* A subroutine of assign_parms. Adjust the parameter list to incorporate
2357 the hidden struct return argument, and (abi willing) complex args.
2358 Return the new parameter list. */
2360 static vec<tree>
2361 assign_parms_augmented_arg_list (struct assign_parm_data_all *all)
2363 tree fndecl = current_function_decl;
2364 tree fntype = TREE_TYPE (fndecl);
2365 vec<tree> fnargs = vNULL;
2366 tree arg;
2368 for (arg = DECL_ARGUMENTS (fndecl); arg; arg = DECL_CHAIN (arg))
2369 fnargs.safe_push (arg);
2371 all->orig_fnargs = DECL_ARGUMENTS (fndecl);
2373 /* If struct value address is treated as the first argument, make it so. */
2374 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
2375 && ! cfun->returns_pcc_struct
2376 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
2378 tree type = build_pointer_type (TREE_TYPE (fntype));
2379 tree decl;
2381 decl = build_decl (DECL_SOURCE_LOCATION (fndecl),
2382 PARM_DECL, get_identifier (".result_ptr"), type);
2383 DECL_ARG_TYPE (decl) = type;
2384 DECL_ARTIFICIAL (decl) = 1;
2385 DECL_NAMELESS (decl) = 1;
2386 TREE_CONSTANT (decl) = 1;
2387 /* We don't set DECL_IGNORED_P or DECL_REGISTER here. If this
2388 changes, the end of the RESULT_DECL handling block in
2389 use_register_for_decl must be adjusted to match. */
2391 DECL_CHAIN (decl) = all->orig_fnargs;
2392 all->orig_fnargs = decl;
2393 fnargs.safe_insert (0, decl);
2395 all->function_result_decl = decl;
2397 /* If function is instrumented then bounds of the
2398 passed structure address is the second argument. */
2399 if (chkp_function_instrumented_p (fndecl))
2401 decl = build_decl (DECL_SOURCE_LOCATION (fndecl),
2402 PARM_DECL, get_identifier (".result_bnd"),
2403 pointer_bounds_type_node);
2404 DECL_ARG_TYPE (decl) = pointer_bounds_type_node;
2405 DECL_ARTIFICIAL (decl) = 1;
2406 DECL_NAMELESS (decl) = 1;
2407 TREE_CONSTANT (decl) = 1;
2409 DECL_CHAIN (decl) = DECL_CHAIN (all->orig_fnargs);
2410 DECL_CHAIN (all->orig_fnargs) = decl;
2411 fnargs.safe_insert (1, decl);
2415 /* If the target wants to split complex arguments into scalars, do so. */
2416 if (targetm.calls.split_complex_arg)
2417 split_complex_args (&fnargs);
2419 return fnargs;
2422 /* A subroutine of assign_parms. Examine PARM and pull out type and mode
2423 data for the parameter. Incorporate ABI specifics such as pass-by-
2424 reference and type promotion. */
2426 static void
2427 assign_parm_find_data_types (struct assign_parm_data_all *all, tree parm,
2428 struct assign_parm_data_one *data)
2430 tree nominal_type, passed_type;
2431 machine_mode nominal_mode, passed_mode, promoted_mode;
2432 int unsignedp;
2434 memset (data, 0, sizeof (*data));
2436 /* NAMED_ARG is a misnomer. We really mean 'non-variadic'. */
2437 if (!cfun->stdarg)
2438 data->named_arg = 1; /* No variadic parms. */
2439 else if (DECL_CHAIN (parm))
2440 data->named_arg = 1; /* Not the last non-variadic parm. */
2441 else if (targetm.calls.strict_argument_naming (all->args_so_far))
2442 data->named_arg = 1; /* Only variadic ones are unnamed. */
2443 else
2444 data->named_arg = 0; /* Treat as variadic. */
2446 nominal_type = TREE_TYPE (parm);
2447 passed_type = DECL_ARG_TYPE (parm);
2449 /* Look out for errors propagating this far. Also, if the parameter's
2450 type is void then its value doesn't matter. */
2451 if (TREE_TYPE (parm) == error_mark_node
2452 /* This can happen after weird syntax errors
2453 or if an enum type is defined among the parms. */
2454 || TREE_CODE (parm) != PARM_DECL
2455 || passed_type == NULL
2456 || VOID_TYPE_P (nominal_type))
2458 nominal_type = passed_type = void_type_node;
2459 nominal_mode = passed_mode = promoted_mode = VOIDmode;
2460 goto egress;
2463 /* Find mode of arg as it is passed, and mode of arg as it should be
2464 during execution of this function. */
2465 passed_mode = TYPE_MODE (passed_type);
2466 nominal_mode = TYPE_MODE (nominal_type);
2468 /* If the parm is to be passed as a transparent union or record, use the
2469 type of the first field for the tests below. We have already verified
2470 that the modes are the same. */
2471 if ((TREE_CODE (passed_type) == UNION_TYPE
2472 || TREE_CODE (passed_type) == RECORD_TYPE)
2473 && TYPE_TRANSPARENT_AGGR (passed_type))
2474 passed_type = TREE_TYPE (first_field (passed_type));
2476 /* See if this arg was passed by invisible reference. */
2477 if (pass_by_reference (&all->args_so_far_v, passed_mode,
2478 passed_type, data->named_arg))
2480 passed_type = nominal_type = build_pointer_type (passed_type);
2481 data->passed_pointer = true;
2482 passed_mode = nominal_mode = TYPE_MODE (nominal_type);
2485 /* Find mode as it is passed by the ABI. */
2486 unsignedp = TYPE_UNSIGNED (passed_type);
2487 promoted_mode = promote_function_mode (passed_type, passed_mode, &unsignedp,
2488 TREE_TYPE (current_function_decl), 0);
2490 egress:
2491 data->nominal_type = nominal_type;
2492 data->passed_type = passed_type;
2493 data->nominal_mode = nominal_mode;
2494 data->passed_mode = passed_mode;
2495 data->promoted_mode = promoted_mode;
2498 /* A subroutine of assign_parms. Invoke setup_incoming_varargs. */
2500 static void
2501 assign_parms_setup_varargs (struct assign_parm_data_all *all,
2502 struct assign_parm_data_one *data, bool no_rtl)
2504 int varargs_pretend_bytes = 0;
2506 targetm.calls.setup_incoming_varargs (all->args_so_far,
2507 data->promoted_mode,
2508 data->passed_type,
2509 &varargs_pretend_bytes, no_rtl);
2511 /* If the back-end has requested extra stack space, record how much is
2512 needed. Do not change pretend_args_size otherwise since it may be
2513 nonzero from an earlier partial argument. */
2514 if (varargs_pretend_bytes > 0)
2515 all->pretend_args_size = varargs_pretend_bytes;
2518 /* A subroutine of assign_parms. Set DATA->ENTRY_PARM corresponding to
2519 the incoming location of the current parameter. */
2521 static void
2522 assign_parm_find_entry_rtl (struct assign_parm_data_all *all,
2523 struct assign_parm_data_one *data)
2525 HOST_WIDE_INT pretend_bytes = 0;
2526 rtx entry_parm;
2527 bool in_regs;
2529 if (data->promoted_mode == VOIDmode)
2531 data->entry_parm = data->stack_parm = const0_rtx;
2532 return;
2535 targetm.calls.warn_parameter_passing_abi (all->args_so_far,
2536 data->passed_type);
2538 entry_parm = targetm.calls.function_incoming_arg (all->args_so_far,
2539 data->promoted_mode,
2540 data->passed_type,
2541 data->named_arg);
2543 if (entry_parm == 0)
2544 data->promoted_mode = data->passed_mode;
2546 /* Determine parm's home in the stack, in case it arrives in the stack
2547 or we should pretend it did. Compute the stack position and rtx where
2548 the argument arrives and its size.
2550 There is one complexity here: If this was a parameter that would
2551 have been passed in registers, but wasn't only because it is
2552 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2553 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2554 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of 0
2555 as it was the previous time. */
2556 in_regs = (entry_parm != 0) || POINTER_BOUNDS_TYPE_P (data->passed_type);
2557 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2558 in_regs = true;
2559 #endif
2560 if (!in_regs && !data->named_arg)
2562 if (targetm.calls.pretend_outgoing_varargs_named (all->args_so_far))
2564 rtx tem;
2565 tem = targetm.calls.function_incoming_arg (all->args_so_far,
2566 data->promoted_mode,
2567 data->passed_type, true);
2568 in_regs = tem != NULL;
2572 /* If this parameter was passed both in registers and in the stack, use
2573 the copy on the stack. */
2574 if (targetm.calls.must_pass_in_stack (data->promoted_mode,
2575 data->passed_type))
2576 entry_parm = 0;
2578 if (entry_parm)
2580 int partial;
2582 partial = targetm.calls.arg_partial_bytes (all->args_so_far,
2583 data->promoted_mode,
2584 data->passed_type,
2585 data->named_arg);
2586 data->partial = partial;
2588 /* The caller might already have allocated stack space for the
2589 register parameters. */
2590 if (partial != 0 && all->reg_parm_stack_space == 0)
2592 /* Part of this argument is passed in registers and part
2593 is passed on the stack. Ask the prologue code to extend
2594 the stack part so that we can recreate the full value.
2596 PRETEND_BYTES is the size of the registers we need to store.
2597 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
2598 stack space that the prologue should allocate.
2600 Internally, gcc assumes that the argument pointer is aligned
2601 to STACK_BOUNDARY bits. This is used both for alignment
2602 optimizations (see init_emit) and to locate arguments that are
2603 aligned to more than PARM_BOUNDARY bits. We must preserve this
2604 invariant by rounding CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to
2605 a stack boundary. */
2607 /* We assume at most one partial arg, and it must be the first
2608 argument on the stack. */
2609 gcc_assert (!all->extra_pretend_bytes && !all->pretend_args_size);
2611 pretend_bytes = partial;
2612 all->pretend_args_size = CEIL_ROUND (pretend_bytes, STACK_BYTES);
2614 /* We want to align relative to the actual stack pointer, so
2615 don't include this in the stack size until later. */
2616 all->extra_pretend_bytes = all->pretend_args_size;
2620 locate_and_pad_parm (data->promoted_mode, data->passed_type, in_regs,
2621 all->reg_parm_stack_space,
2622 entry_parm ? data->partial : 0, current_function_decl,
2623 &all->stack_args_size, &data->locate);
2625 /* Update parm_stack_boundary if this parameter is passed in the
2626 stack. */
2627 if (!in_regs && crtl->parm_stack_boundary < data->locate.boundary)
2628 crtl->parm_stack_boundary = data->locate.boundary;
2630 /* Adjust offsets to include the pretend args. */
2631 pretend_bytes = all->extra_pretend_bytes - pretend_bytes;
2632 data->locate.slot_offset.constant += pretend_bytes;
2633 data->locate.offset.constant += pretend_bytes;
2635 data->entry_parm = entry_parm;
2638 /* A subroutine of assign_parms. If there is actually space on the stack
2639 for this parm, count it in stack_args_size and return true. */
2641 static bool
2642 assign_parm_is_stack_parm (struct assign_parm_data_all *all,
2643 struct assign_parm_data_one *data)
2645 /* Bounds are never passed on the stack to keep compatibility
2646 with not instrumented code. */
2647 if (POINTER_BOUNDS_TYPE_P (data->passed_type))
2648 return false;
2649 /* Trivially true if we've no incoming register. */
2650 else if (data->entry_parm == NULL)
2652 /* Also true if we're partially in registers and partially not,
2653 since we've arranged to drop the entire argument on the stack. */
2654 else if (data->partial != 0)
2656 /* Also true if the target says that it's passed in both registers
2657 and on the stack. */
2658 else if (GET_CODE (data->entry_parm) == PARALLEL
2659 && XEXP (XVECEXP (data->entry_parm, 0, 0), 0) == NULL_RTX)
2661 /* Also true if the target says that there's stack allocated for
2662 all register parameters. */
2663 else if (all->reg_parm_stack_space > 0)
2665 /* Otherwise, no, this parameter has no ABI defined stack slot. */
2666 else
2667 return false;
2669 all->stack_args_size.constant += data->locate.size.constant;
2670 if (data->locate.size.var)
2671 ADD_PARM_SIZE (all->stack_args_size, data->locate.size.var);
2673 return true;
2676 /* A subroutine of assign_parms. Given that this parameter is allocated
2677 stack space by the ABI, find it. */
2679 static void
2680 assign_parm_find_stack_rtl (tree parm, struct assign_parm_data_one *data)
2682 rtx offset_rtx, stack_parm;
2683 unsigned int align, boundary;
2685 /* If we're passing this arg using a reg, make its stack home the
2686 aligned stack slot. */
2687 if (data->entry_parm)
2688 offset_rtx = ARGS_SIZE_RTX (data->locate.slot_offset);
2689 else
2690 offset_rtx = ARGS_SIZE_RTX (data->locate.offset);
2692 stack_parm = crtl->args.internal_arg_pointer;
2693 if (offset_rtx != const0_rtx)
2694 stack_parm = gen_rtx_PLUS (Pmode, stack_parm, offset_rtx);
2695 stack_parm = gen_rtx_MEM (data->promoted_mode, stack_parm);
2697 if (!data->passed_pointer)
2699 set_mem_attributes (stack_parm, parm, 1);
2700 /* set_mem_attributes could set MEM_SIZE to the passed mode's size,
2701 while promoted mode's size is needed. */
2702 if (data->promoted_mode != BLKmode
2703 && data->promoted_mode != DECL_MODE (parm))
2705 set_mem_size (stack_parm, GET_MODE_SIZE (data->promoted_mode));
2706 if (MEM_EXPR (stack_parm) && MEM_OFFSET_KNOWN_P (stack_parm))
2708 int offset = subreg_lowpart_offset (DECL_MODE (parm),
2709 data->promoted_mode);
2710 if (offset)
2711 set_mem_offset (stack_parm, MEM_OFFSET (stack_parm) - offset);
2716 boundary = data->locate.boundary;
2717 align = BITS_PER_UNIT;
2719 /* If we're padding upward, we know that the alignment of the slot
2720 is TARGET_FUNCTION_ARG_BOUNDARY. If we're using slot_offset, we're
2721 intentionally forcing upward padding. Otherwise we have to come
2722 up with a guess at the alignment based on OFFSET_RTX. */
2723 if (data->locate.where_pad != PAD_DOWNWARD || data->entry_parm)
2724 align = boundary;
2725 else if (CONST_INT_P (offset_rtx))
2727 align = INTVAL (offset_rtx) * BITS_PER_UNIT | boundary;
2728 align = least_bit_hwi (align);
2730 set_mem_align (stack_parm, align);
2732 if (data->entry_parm)
2733 set_reg_attrs_for_parm (data->entry_parm, stack_parm);
2735 data->stack_parm = stack_parm;
2738 /* A subroutine of assign_parms. Adjust DATA->ENTRY_RTL such that it's
2739 always valid and contiguous. */
2741 static void
2742 assign_parm_adjust_entry_rtl (struct assign_parm_data_one *data)
2744 rtx entry_parm = data->entry_parm;
2745 rtx stack_parm = data->stack_parm;
2747 /* If this parm was passed part in regs and part in memory, pretend it
2748 arrived entirely in memory by pushing the register-part onto the stack.
2749 In the special case of a DImode or DFmode that is split, we could put
2750 it together in a pseudoreg directly, but for now that's not worth
2751 bothering with. */
2752 if (data->partial != 0)
2754 /* Handle calls that pass values in multiple non-contiguous
2755 locations. The Irix 6 ABI has examples of this. */
2756 if (GET_CODE (entry_parm) == PARALLEL)
2757 emit_group_store (validize_mem (copy_rtx (stack_parm)), entry_parm,
2758 data->passed_type,
2759 int_size_in_bytes (data->passed_type));
2760 else
2762 gcc_assert (data->partial % UNITS_PER_WORD == 0);
2763 move_block_from_reg (REGNO (entry_parm),
2764 validize_mem (copy_rtx (stack_parm)),
2765 data->partial / UNITS_PER_WORD);
2768 entry_parm = stack_parm;
2771 /* If we didn't decide this parm came in a register, by default it came
2772 on the stack. */
2773 else if (entry_parm == NULL)
2774 entry_parm = stack_parm;
2776 /* When an argument is passed in multiple locations, we can't make use
2777 of this information, but we can save some copying if the whole argument
2778 is passed in a single register. */
2779 else if (GET_CODE (entry_parm) == PARALLEL
2780 && data->nominal_mode != BLKmode
2781 && data->passed_mode != BLKmode)
2783 size_t i, len = XVECLEN (entry_parm, 0);
2785 for (i = 0; i < len; i++)
2786 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
2787 && REG_P (XEXP (XVECEXP (entry_parm, 0, i), 0))
2788 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
2789 == data->passed_mode)
2790 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
2792 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
2793 break;
2797 data->entry_parm = entry_parm;
2800 /* A subroutine of assign_parms. Reconstitute any values which were
2801 passed in multiple registers and would fit in a single register. */
2803 static void
2804 assign_parm_remove_parallels (struct assign_parm_data_one *data)
2806 rtx entry_parm = data->entry_parm;
2808 /* Convert the PARALLEL to a REG of the same mode as the parallel.
2809 This can be done with register operations rather than on the
2810 stack, even if we will store the reconstituted parameter on the
2811 stack later. */
2812 if (GET_CODE (entry_parm) == PARALLEL && GET_MODE (entry_parm) != BLKmode)
2814 rtx parmreg = gen_reg_rtx (GET_MODE (entry_parm));
2815 emit_group_store (parmreg, entry_parm, data->passed_type,
2816 GET_MODE_SIZE (GET_MODE (entry_parm)));
2817 entry_parm = parmreg;
2820 data->entry_parm = entry_parm;
2823 /* A subroutine of assign_parms. Adjust DATA->STACK_RTL such that it's
2824 always valid and properly aligned. */
2826 static void
2827 assign_parm_adjust_stack_rtl (struct assign_parm_data_one *data)
2829 rtx stack_parm = data->stack_parm;
2831 /* If we can't trust the parm stack slot to be aligned enough for its
2832 ultimate type, don't use that slot after entry. We'll make another
2833 stack slot, if we need one. */
2834 if (stack_parm
2835 && ((STRICT_ALIGNMENT
2836 && GET_MODE_ALIGNMENT (data->nominal_mode) > MEM_ALIGN (stack_parm))
2837 || (data->nominal_type
2838 && TYPE_ALIGN (data->nominal_type) > MEM_ALIGN (stack_parm)
2839 && MEM_ALIGN (stack_parm) < PREFERRED_STACK_BOUNDARY)))
2840 stack_parm = NULL;
2842 /* If parm was passed in memory, and we need to convert it on entry,
2843 don't store it back in that same slot. */
2844 else if (data->entry_parm == stack_parm
2845 && data->nominal_mode != BLKmode
2846 && data->nominal_mode != data->passed_mode)
2847 stack_parm = NULL;
2849 /* If stack protection is in effect for this function, don't leave any
2850 pointers in their passed stack slots. */
2851 else if (crtl->stack_protect_guard
2852 && (flag_stack_protect == 2
2853 || data->passed_pointer
2854 || POINTER_TYPE_P (data->nominal_type)))
2855 stack_parm = NULL;
2857 data->stack_parm = stack_parm;
2860 /* A subroutine of assign_parms. Return true if the current parameter
2861 should be stored as a BLKmode in the current frame. */
2863 static bool
2864 assign_parm_setup_block_p (struct assign_parm_data_one *data)
2866 if (data->nominal_mode == BLKmode)
2867 return true;
2868 if (GET_MODE (data->entry_parm) == BLKmode)
2869 return true;
2871 #ifdef BLOCK_REG_PADDING
2872 /* Only assign_parm_setup_block knows how to deal with register arguments
2873 that are padded at the least significant end. */
2874 if (REG_P (data->entry_parm)
2875 && GET_MODE_SIZE (data->promoted_mode) < UNITS_PER_WORD
2876 && (BLOCK_REG_PADDING (data->passed_mode, data->passed_type, 1)
2877 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
2878 return true;
2879 #endif
2881 return false;
2884 /* A subroutine of assign_parms. Arrange for the parameter to be
2885 present and valid in DATA->STACK_RTL. */
2887 static void
2888 assign_parm_setup_block (struct assign_parm_data_all *all,
2889 tree parm, struct assign_parm_data_one *data)
2891 rtx entry_parm = data->entry_parm;
2892 rtx stack_parm = data->stack_parm;
2893 rtx target_reg = NULL_RTX;
2894 bool in_conversion_seq = false;
2895 HOST_WIDE_INT size;
2896 HOST_WIDE_INT size_stored;
2898 if (GET_CODE (entry_parm) == PARALLEL)
2899 entry_parm = emit_group_move_into_temps (entry_parm);
2901 /* If we want the parameter in a pseudo, don't use a stack slot. */
2902 if (is_gimple_reg (parm) && use_register_for_decl (parm))
2904 tree def = ssa_default_def (cfun, parm);
2905 gcc_assert (def);
2906 machine_mode mode = promote_ssa_mode (def, NULL);
2907 rtx reg = gen_reg_rtx (mode);
2908 if (GET_CODE (reg) != CONCAT)
2909 stack_parm = reg;
2910 else
2912 target_reg = reg;
2913 /* Avoid allocating a stack slot, if there isn't one
2914 preallocated by the ABI. It might seem like we should
2915 always prefer a pseudo, but converting between
2916 floating-point and integer modes goes through the stack
2917 on various machines, so it's better to use the reserved
2918 stack slot than to risk wasting it and allocating more
2919 for the conversion. */
2920 if (stack_parm == NULL_RTX)
2922 int save = generating_concat_p;
2923 generating_concat_p = 0;
2924 stack_parm = gen_reg_rtx (mode);
2925 generating_concat_p = save;
2928 data->stack_parm = NULL;
2931 size = int_size_in_bytes (data->passed_type);
2932 size_stored = CEIL_ROUND (size, UNITS_PER_WORD);
2933 if (stack_parm == 0)
2935 SET_DECL_ALIGN (parm, MAX (DECL_ALIGN (parm), BITS_PER_WORD));
2936 stack_parm = assign_stack_local (BLKmode, size_stored,
2937 DECL_ALIGN (parm));
2938 if (GET_MODE_SIZE (GET_MODE (entry_parm)) == size)
2939 PUT_MODE (stack_parm, GET_MODE (entry_parm));
2940 set_mem_attributes (stack_parm, parm, 1);
2943 /* If a BLKmode arrives in registers, copy it to a stack slot. Handle
2944 calls that pass values in multiple non-contiguous locations. */
2945 if (REG_P (entry_parm) || GET_CODE (entry_parm) == PARALLEL)
2947 rtx mem;
2949 /* Note that we will be storing an integral number of words.
2950 So we have to be careful to ensure that we allocate an
2951 integral number of words. We do this above when we call
2952 assign_stack_local if space was not allocated in the argument
2953 list. If it was, this will not work if PARM_BOUNDARY is not
2954 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2955 if it becomes a problem. Exception is when BLKmode arrives
2956 with arguments not conforming to word_mode. */
2958 if (data->stack_parm == 0)
2960 else if (GET_CODE (entry_parm) == PARALLEL)
2962 else
2963 gcc_assert (!size || !(PARM_BOUNDARY % BITS_PER_WORD));
2965 mem = validize_mem (copy_rtx (stack_parm));
2967 /* Handle values in multiple non-contiguous locations. */
2968 if (GET_CODE (entry_parm) == PARALLEL && !MEM_P (mem))
2969 emit_group_store (mem, entry_parm, data->passed_type, size);
2970 else if (GET_CODE (entry_parm) == PARALLEL)
2972 push_to_sequence2 (all->first_conversion_insn,
2973 all->last_conversion_insn);
2974 emit_group_store (mem, entry_parm, data->passed_type, size);
2975 all->first_conversion_insn = get_insns ();
2976 all->last_conversion_insn = get_last_insn ();
2977 end_sequence ();
2978 in_conversion_seq = true;
2981 else if (size == 0)
2984 /* If SIZE is that of a mode no bigger than a word, just use
2985 that mode's store operation. */
2986 else if (size <= UNITS_PER_WORD)
2988 unsigned int bits = size * BITS_PER_UNIT;
2989 machine_mode mode = int_mode_for_size (bits, 0).else_blk ();
2991 if (mode != BLKmode
2992 #ifdef BLOCK_REG_PADDING
2993 && (size == UNITS_PER_WORD
2994 || (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2995 != (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
2996 #endif
2999 rtx reg;
3001 /* We are really truncating a word_mode value containing
3002 SIZE bytes into a value of mode MODE. If such an
3003 operation requires no actual instructions, we can refer
3004 to the value directly in mode MODE, otherwise we must
3005 start with the register in word_mode and explicitly
3006 convert it. */
3007 if (targetm.truly_noop_truncation (size * BITS_PER_UNIT,
3008 BITS_PER_WORD))
3009 reg = gen_rtx_REG (mode, REGNO (entry_parm));
3010 else
3012 reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
3013 reg = convert_to_mode (mode, copy_to_reg (reg), 1);
3015 emit_move_insn (change_address (mem, mode, 0), reg);
3018 #ifdef BLOCK_REG_PADDING
3019 /* Storing the register in memory as a full word, as
3020 move_block_from_reg below would do, and then using the
3021 MEM in a smaller mode, has the effect of shifting right
3022 if BYTES_BIG_ENDIAN. If we're bypassing memory, the
3023 shifting must be explicit. */
3024 else if (!MEM_P (mem))
3026 rtx x;
3028 /* If the assert below fails, we should have taken the
3029 mode != BLKmode path above, unless we have downward
3030 padding of smaller-than-word arguments on a machine
3031 with little-endian bytes, which would likely require
3032 additional changes to work correctly. */
3033 gcc_checking_assert (BYTES_BIG_ENDIAN
3034 && (BLOCK_REG_PADDING (mode,
3035 data->passed_type, 1)
3036 == PAD_UPWARD));
3038 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
3040 x = gen_rtx_REG (word_mode, REGNO (entry_parm));
3041 x = expand_shift (RSHIFT_EXPR, word_mode, x, by,
3042 NULL_RTX, 1);
3043 x = force_reg (word_mode, x);
3044 x = gen_lowpart_SUBREG (GET_MODE (mem), x);
3046 emit_move_insn (mem, x);
3048 #endif
3050 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
3051 machine must be aligned to the left before storing
3052 to memory. Note that the previous test doesn't
3053 handle all cases (e.g. SIZE == 3). */
3054 else if (size != UNITS_PER_WORD
3055 #ifdef BLOCK_REG_PADDING
3056 && (BLOCK_REG_PADDING (mode, data->passed_type, 1)
3057 == PAD_DOWNWARD)
3058 #else
3059 && BYTES_BIG_ENDIAN
3060 #endif
3063 rtx tem, x;
3064 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
3065 rtx reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
3067 x = expand_shift (LSHIFT_EXPR, word_mode, reg, by, NULL_RTX, 1);
3068 tem = change_address (mem, word_mode, 0);
3069 emit_move_insn (tem, x);
3071 else
3072 move_block_from_reg (REGNO (entry_parm), mem,
3073 size_stored / UNITS_PER_WORD);
3075 else if (!MEM_P (mem))
3077 gcc_checking_assert (size > UNITS_PER_WORD);
3078 #ifdef BLOCK_REG_PADDING
3079 gcc_checking_assert (BLOCK_REG_PADDING (GET_MODE (mem),
3080 data->passed_type, 0)
3081 == PAD_UPWARD);
3082 #endif
3083 emit_move_insn (mem, entry_parm);
3085 else
3086 move_block_from_reg (REGNO (entry_parm), mem,
3087 size_stored / UNITS_PER_WORD);
3089 else if (data->stack_parm == 0)
3091 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3092 emit_block_move (stack_parm, data->entry_parm, GEN_INT (size),
3093 BLOCK_OP_NORMAL);
3094 all->first_conversion_insn = get_insns ();
3095 all->last_conversion_insn = get_last_insn ();
3096 end_sequence ();
3097 in_conversion_seq = true;
3100 if (target_reg)
3102 if (!in_conversion_seq)
3103 emit_move_insn (target_reg, stack_parm);
3104 else
3106 push_to_sequence2 (all->first_conversion_insn,
3107 all->last_conversion_insn);
3108 emit_move_insn (target_reg, stack_parm);
3109 all->first_conversion_insn = get_insns ();
3110 all->last_conversion_insn = get_last_insn ();
3111 end_sequence ();
3113 stack_parm = target_reg;
3116 data->stack_parm = stack_parm;
3117 set_parm_rtl (parm, stack_parm);
3120 /* A subroutine of assign_parms. Allocate a pseudo to hold the current
3121 parameter. Get it there. Perform all ABI specified conversions. */
3123 static void
3124 assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm,
3125 struct assign_parm_data_one *data)
3127 rtx parmreg, validated_mem;
3128 rtx equiv_stack_parm;
3129 machine_mode promoted_nominal_mode;
3130 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (parm));
3131 bool did_conversion = false;
3132 bool need_conversion, moved;
3133 rtx rtl;
3135 /* Store the parm in a pseudoregister during the function, but we may
3136 need to do it in a wider mode. Using 2 here makes the result
3137 consistent with promote_decl_mode and thus expand_expr_real_1. */
3138 promoted_nominal_mode
3139 = promote_function_mode (data->nominal_type, data->nominal_mode, &unsignedp,
3140 TREE_TYPE (current_function_decl), 2);
3142 parmreg = gen_reg_rtx (promoted_nominal_mode);
3143 if (!DECL_ARTIFICIAL (parm))
3144 mark_user_reg (parmreg);
3146 /* If this was an item that we received a pointer to,
3147 set rtl appropriately. */
3148 if (data->passed_pointer)
3150 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data->passed_type)), parmreg);
3151 set_mem_attributes (rtl, parm, 1);
3153 else
3154 rtl = parmreg;
3156 assign_parm_remove_parallels (data);
3158 /* Copy the value into the register, thus bridging between
3159 assign_parm_find_data_types and expand_expr_real_1. */
3161 equiv_stack_parm = data->stack_parm;
3162 validated_mem = validize_mem (copy_rtx (data->entry_parm));
3164 need_conversion = (data->nominal_mode != data->passed_mode
3165 || promoted_nominal_mode != data->promoted_mode);
3166 moved = false;
3168 if (need_conversion
3169 && GET_MODE_CLASS (data->nominal_mode) == MODE_INT
3170 && data->nominal_mode == data->passed_mode
3171 && data->nominal_mode == GET_MODE (data->entry_parm))
3173 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
3174 mode, by the caller. We now have to convert it to
3175 NOMINAL_MODE, if different. However, PARMREG may be in
3176 a different mode than NOMINAL_MODE if it is being stored
3177 promoted.
3179 If ENTRY_PARM is a hard register, it might be in a register
3180 not valid for operating in its mode (e.g., an odd-numbered
3181 register for a DFmode). In that case, moves are the only
3182 thing valid, so we can't do a convert from there. This
3183 occurs when the calling sequence allow such misaligned
3184 usages.
3186 In addition, the conversion may involve a call, which could
3187 clobber parameters which haven't been copied to pseudo
3188 registers yet.
3190 First, we try to emit an insn which performs the necessary
3191 conversion. We verify that this insn does not clobber any
3192 hard registers. */
3194 enum insn_code icode;
3195 rtx op0, op1;
3197 icode = can_extend_p (promoted_nominal_mode, data->passed_mode,
3198 unsignedp);
3200 op0 = parmreg;
3201 op1 = validated_mem;
3202 if (icode != CODE_FOR_nothing
3203 && insn_operand_matches (icode, 0, op0)
3204 && insn_operand_matches (icode, 1, op1))
3206 enum rtx_code code = unsignedp ? ZERO_EXTEND : SIGN_EXTEND;
3207 rtx_insn *insn, *insns;
3208 rtx t = op1;
3209 HARD_REG_SET hardregs;
3211 start_sequence ();
3212 /* If op1 is a hard register that is likely spilled, first
3213 force it into a pseudo, otherwise combiner might extend
3214 its lifetime too much. */
3215 if (GET_CODE (t) == SUBREG)
3216 t = SUBREG_REG (t);
3217 if (REG_P (t)
3218 && HARD_REGISTER_P (t)
3219 && ! TEST_HARD_REG_BIT (fixed_reg_set, REGNO (t))
3220 && targetm.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (t))))
3222 t = gen_reg_rtx (GET_MODE (op1));
3223 emit_move_insn (t, op1);
3225 else
3226 t = op1;
3227 rtx_insn *pat = gen_extend_insn (op0, t, promoted_nominal_mode,
3228 data->passed_mode, unsignedp);
3229 emit_insn (pat);
3230 insns = get_insns ();
3232 moved = true;
3233 CLEAR_HARD_REG_SET (hardregs);
3234 for (insn = insns; insn && moved; insn = NEXT_INSN (insn))
3236 if (INSN_P (insn))
3237 note_stores (PATTERN (insn), record_hard_reg_sets,
3238 &hardregs);
3239 if (!hard_reg_set_empty_p (hardregs))
3240 moved = false;
3243 end_sequence ();
3245 if (moved)
3247 emit_insn (insns);
3248 if (equiv_stack_parm != NULL_RTX)
3249 equiv_stack_parm = gen_rtx_fmt_e (code, GET_MODE (parmreg),
3250 equiv_stack_parm);
3255 if (moved)
3256 /* Nothing to do. */
3258 else if (need_conversion)
3260 /* We did not have an insn to convert directly, or the sequence
3261 generated appeared unsafe. We must first copy the parm to a
3262 pseudo reg, and save the conversion until after all
3263 parameters have been moved. */
3265 int save_tree_used;
3266 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
3268 emit_move_insn (tempreg, validated_mem);
3270 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3271 tempreg = convert_to_mode (data->nominal_mode, tempreg, unsignedp);
3273 if (partial_subreg_p (tempreg)
3274 && GET_MODE (tempreg) == data->nominal_mode
3275 && REG_P (SUBREG_REG (tempreg))
3276 && data->nominal_mode == data->passed_mode
3277 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (data->entry_parm))
3279 /* The argument is already sign/zero extended, so note it
3280 into the subreg. */
3281 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
3282 SUBREG_PROMOTED_SET (tempreg, unsignedp);
3285 /* TREE_USED gets set erroneously during expand_assignment. */
3286 save_tree_used = TREE_USED (parm);
3287 SET_DECL_RTL (parm, rtl);
3288 expand_assignment (parm, make_tree (data->nominal_type, tempreg), false);
3289 SET_DECL_RTL (parm, NULL_RTX);
3290 TREE_USED (parm) = save_tree_used;
3291 all->first_conversion_insn = get_insns ();
3292 all->last_conversion_insn = get_last_insn ();
3293 end_sequence ();
3295 did_conversion = true;
3297 else
3298 emit_move_insn (parmreg, validated_mem);
3300 /* If we were passed a pointer but the actual value can safely live
3301 in a register, retrieve it and use it directly. */
3302 if (data->passed_pointer && TYPE_MODE (TREE_TYPE (parm)) != BLKmode)
3304 /* We can't use nominal_mode, because it will have been set to
3305 Pmode above. We must use the actual mode of the parm. */
3306 if (use_register_for_decl (parm))
3308 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
3309 mark_user_reg (parmreg);
3311 else
3313 int align = STACK_SLOT_ALIGNMENT (TREE_TYPE (parm),
3314 TYPE_MODE (TREE_TYPE (parm)),
3315 TYPE_ALIGN (TREE_TYPE (parm)));
3316 parmreg
3317 = assign_stack_local (TYPE_MODE (TREE_TYPE (parm)),
3318 GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (parm))),
3319 align);
3320 set_mem_attributes (parmreg, parm, 1);
3323 /* We need to preserve an address based on VIRTUAL_STACK_VARS_REGNUM for
3324 the debug info in case it is not legitimate. */
3325 if (GET_MODE (parmreg) != GET_MODE (rtl))
3327 rtx tempreg = gen_reg_rtx (GET_MODE (rtl));
3328 int unsigned_p = TYPE_UNSIGNED (TREE_TYPE (parm));
3330 push_to_sequence2 (all->first_conversion_insn,
3331 all->last_conversion_insn);
3332 emit_move_insn (tempreg, rtl);
3333 tempreg = convert_to_mode (GET_MODE (parmreg), tempreg, unsigned_p);
3334 emit_move_insn (MEM_P (parmreg) ? copy_rtx (parmreg) : parmreg,
3335 tempreg);
3336 all->first_conversion_insn = get_insns ();
3337 all->last_conversion_insn = get_last_insn ();
3338 end_sequence ();
3340 did_conversion = true;
3342 else
3343 emit_move_insn (MEM_P (parmreg) ? copy_rtx (parmreg) : parmreg, rtl);
3345 rtl = parmreg;
3347 /* STACK_PARM is the pointer, not the parm, and PARMREG is
3348 now the parm. */
3349 data->stack_parm = NULL;
3352 set_parm_rtl (parm, rtl);
3354 /* Mark the register as eliminable if we did no conversion and it was
3355 copied from memory at a fixed offset, and the arg pointer was not
3356 copied to a pseudo-reg. If the arg pointer is a pseudo reg or the
3357 offset formed an invalid address, such memory-equivalences as we
3358 make here would screw up life analysis for it. */
3359 if (data->nominal_mode == data->passed_mode
3360 && !did_conversion
3361 && data->stack_parm != 0
3362 && MEM_P (data->stack_parm)
3363 && data->locate.offset.var == 0
3364 && reg_mentioned_p (virtual_incoming_args_rtx,
3365 XEXP (data->stack_parm, 0)))
3367 rtx_insn *linsn = get_last_insn ();
3368 rtx_insn *sinsn;
3369 rtx set;
3371 /* Mark complex types separately. */
3372 if (GET_CODE (parmreg) == CONCAT)
3374 scalar_mode submode = GET_MODE_INNER (GET_MODE (parmreg));
3375 int regnor = REGNO (XEXP (parmreg, 0));
3376 int regnoi = REGNO (XEXP (parmreg, 1));
3377 rtx stackr = adjust_address_nv (data->stack_parm, submode, 0);
3378 rtx stacki = adjust_address_nv (data->stack_parm, submode,
3379 GET_MODE_SIZE (submode));
3381 /* Scan backwards for the set of the real and
3382 imaginary parts. */
3383 for (sinsn = linsn; sinsn != 0;
3384 sinsn = prev_nonnote_insn (sinsn))
3386 set = single_set (sinsn);
3387 if (set == 0)
3388 continue;
3390 if (SET_DEST (set) == regno_reg_rtx [regnoi])
3391 set_unique_reg_note (sinsn, REG_EQUIV, stacki);
3392 else if (SET_DEST (set) == regno_reg_rtx [regnor])
3393 set_unique_reg_note (sinsn, REG_EQUIV, stackr);
3396 else
3397 set_dst_reg_note (linsn, REG_EQUIV, equiv_stack_parm, parmreg);
3400 /* For pointer data type, suggest pointer register. */
3401 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3402 mark_reg_pointer (parmreg,
3403 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
3406 /* A subroutine of assign_parms. Allocate stack space to hold the current
3407 parameter. Get it there. Perform all ABI specified conversions. */
3409 static void
3410 assign_parm_setup_stack (struct assign_parm_data_all *all, tree parm,
3411 struct assign_parm_data_one *data)
3413 /* Value must be stored in the stack slot STACK_PARM during function
3414 execution. */
3415 bool to_conversion = false;
3417 assign_parm_remove_parallels (data);
3419 if (data->promoted_mode != data->nominal_mode)
3421 /* Conversion is required. */
3422 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
3424 emit_move_insn (tempreg, validize_mem (copy_rtx (data->entry_parm)));
3426 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3427 to_conversion = true;
3429 data->entry_parm = convert_to_mode (data->nominal_mode, tempreg,
3430 TYPE_UNSIGNED (TREE_TYPE (parm)));
3432 if (data->stack_parm)
3434 int offset = subreg_lowpart_offset (data->nominal_mode,
3435 GET_MODE (data->stack_parm));
3436 /* ??? This may need a big-endian conversion on sparc64. */
3437 data->stack_parm
3438 = adjust_address (data->stack_parm, data->nominal_mode, 0);
3439 if (offset && MEM_OFFSET_KNOWN_P (data->stack_parm))
3440 set_mem_offset (data->stack_parm,
3441 MEM_OFFSET (data->stack_parm) + offset);
3445 if (data->entry_parm != data->stack_parm)
3447 rtx src, dest;
3449 if (data->stack_parm == 0)
3451 int align = STACK_SLOT_ALIGNMENT (data->passed_type,
3452 GET_MODE (data->entry_parm),
3453 TYPE_ALIGN (data->passed_type));
3454 data->stack_parm
3455 = assign_stack_local (GET_MODE (data->entry_parm),
3456 GET_MODE_SIZE (GET_MODE (data->entry_parm)),
3457 align);
3458 set_mem_attributes (data->stack_parm, parm, 1);
3461 dest = validize_mem (copy_rtx (data->stack_parm));
3462 src = validize_mem (copy_rtx (data->entry_parm));
3464 if (MEM_P (src))
3466 /* Use a block move to handle potentially misaligned entry_parm. */
3467 if (!to_conversion)
3468 push_to_sequence2 (all->first_conversion_insn,
3469 all->last_conversion_insn);
3470 to_conversion = true;
3472 emit_block_move (dest, src,
3473 GEN_INT (int_size_in_bytes (data->passed_type)),
3474 BLOCK_OP_NORMAL);
3476 else
3478 if (!REG_P (src))
3479 src = force_reg (GET_MODE (src), src);
3480 emit_move_insn (dest, src);
3484 if (to_conversion)
3486 all->first_conversion_insn = get_insns ();
3487 all->last_conversion_insn = get_last_insn ();
3488 end_sequence ();
3491 set_parm_rtl (parm, data->stack_parm);
3494 /* A subroutine of assign_parms. If the ABI splits complex arguments, then
3495 undo the frobbing that we did in assign_parms_augmented_arg_list. */
3497 static void
3498 assign_parms_unsplit_complex (struct assign_parm_data_all *all,
3499 vec<tree> fnargs)
3501 tree parm;
3502 tree orig_fnargs = all->orig_fnargs;
3503 unsigned i = 0;
3505 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm), ++i)
3507 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
3508 && targetm.calls.split_complex_arg (TREE_TYPE (parm)))
3510 rtx tmp, real, imag;
3511 scalar_mode inner = GET_MODE_INNER (DECL_MODE (parm));
3513 real = DECL_RTL (fnargs[i]);
3514 imag = DECL_RTL (fnargs[i + 1]);
3515 if (inner != GET_MODE (real))
3517 real = gen_lowpart_SUBREG (inner, real);
3518 imag = gen_lowpart_SUBREG (inner, imag);
3521 if (TREE_ADDRESSABLE (parm))
3523 rtx rmem, imem;
3524 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (parm));
3525 int align = STACK_SLOT_ALIGNMENT (TREE_TYPE (parm),
3526 DECL_MODE (parm),
3527 TYPE_ALIGN (TREE_TYPE (parm)));
3529 /* split_complex_arg put the real and imag parts in
3530 pseudos. Move them to memory. */
3531 tmp = assign_stack_local (DECL_MODE (parm), size, align);
3532 set_mem_attributes (tmp, parm, 1);
3533 rmem = adjust_address_nv (tmp, inner, 0);
3534 imem = adjust_address_nv (tmp, inner, GET_MODE_SIZE (inner));
3535 push_to_sequence2 (all->first_conversion_insn,
3536 all->last_conversion_insn);
3537 emit_move_insn (rmem, real);
3538 emit_move_insn (imem, imag);
3539 all->first_conversion_insn = get_insns ();
3540 all->last_conversion_insn = get_last_insn ();
3541 end_sequence ();
3543 else
3544 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
3545 set_parm_rtl (parm, tmp);
3547 real = DECL_INCOMING_RTL (fnargs[i]);
3548 imag = DECL_INCOMING_RTL (fnargs[i + 1]);
3549 if (inner != GET_MODE (real))
3551 real = gen_lowpart_SUBREG (inner, real);
3552 imag = gen_lowpart_SUBREG (inner, imag);
3554 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
3555 set_decl_incoming_rtl (parm, tmp, false);
3556 i++;
3561 /* Load bounds of PARM from bounds table. */
3562 static void
3563 assign_parm_load_bounds (struct assign_parm_data_one *data,
3564 tree parm,
3565 rtx entry,
3566 unsigned bound_no)
3568 bitmap_iterator bi;
3569 unsigned i, offs = 0;
3570 int bnd_no = -1;
3571 rtx slot = NULL, ptr = NULL;
3573 if (parm)
3575 bitmap slots;
3576 bitmap_obstack_initialize (NULL);
3577 slots = BITMAP_ALLOC (NULL);
3578 chkp_find_bound_slots (TREE_TYPE (parm), slots);
3579 EXECUTE_IF_SET_IN_BITMAP (slots, 0, i, bi)
3581 if (bound_no)
3582 bound_no--;
3583 else
3585 bnd_no = i;
3586 break;
3589 BITMAP_FREE (slots);
3590 bitmap_obstack_release (NULL);
3593 /* We may have bounds not associated with any pointer. */
3594 if (bnd_no != -1)
3595 offs = bnd_no * POINTER_SIZE / BITS_PER_UNIT;
3597 /* Find associated pointer. */
3598 if (bnd_no == -1)
3600 /* If bounds are not associated with any bounds,
3601 then it is passed in a register or special slot. */
3602 gcc_assert (data->entry_parm);
3603 ptr = const0_rtx;
3605 else if (MEM_P (entry))
3606 slot = adjust_address (entry, Pmode, offs);
3607 else if (REG_P (entry))
3608 ptr = gen_rtx_REG (Pmode, REGNO (entry) + bnd_no);
3609 else if (GET_CODE (entry) == PARALLEL)
3610 ptr = chkp_get_value_with_offs (entry, GEN_INT (offs));
3611 else
3612 gcc_unreachable ();
3613 data->entry_parm = targetm.calls.load_bounds_for_arg (slot, ptr,
3614 data->entry_parm);
3617 /* Assign RTL expressions to the function's bounds parameters BNDARGS. */
3619 static void
3620 assign_bounds (vec<bounds_parm_data> &bndargs,
3621 struct assign_parm_data_all &all,
3622 bool assign_regs, bool assign_special,
3623 bool assign_bt)
3625 unsigned i, pass;
3626 bounds_parm_data *pbdata;
3628 if (!bndargs.exists ())
3629 return;
3631 /* We make few passes to store input bounds. Firstly handle bounds
3632 passed in registers. After that we load bounds passed in special
3633 slots. Finally we load bounds from Bounds Table. */
3634 for (pass = 0; pass < 3; pass++)
3635 FOR_EACH_VEC_ELT (bndargs, i, pbdata)
3637 /* Pass 0 => regs only. */
3638 if (pass == 0
3639 && (!assign_regs
3640 ||(!pbdata->parm_data.entry_parm
3641 || GET_CODE (pbdata->parm_data.entry_parm) != REG)))
3642 continue;
3643 /* Pass 1 => slots only. */
3644 else if (pass == 1
3645 && (!assign_special
3646 || (!pbdata->parm_data.entry_parm
3647 || GET_CODE (pbdata->parm_data.entry_parm) == REG)))
3648 continue;
3649 /* Pass 2 => BT only. */
3650 else if (pass == 2
3651 && (!assign_bt
3652 || pbdata->parm_data.entry_parm))
3653 continue;
3655 if (!pbdata->parm_data.entry_parm
3656 || GET_CODE (pbdata->parm_data.entry_parm) != REG)
3657 assign_parm_load_bounds (&pbdata->parm_data, pbdata->ptr_parm,
3658 pbdata->ptr_entry, pbdata->bound_no);
3660 set_decl_incoming_rtl (pbdata->bounds_parm,
3661 pbdata->parm_data.entry_parm, false);
3663 if (assign_parm_setup_block_p (&pbdata->parm_data))
3664 assign_parm_setup_block (&all, pbdata->bounds_parm,
3665 &pbdata->parm_data);
3666 else if (pbdata->parm_data.passed_pointer
3667 || use_register_for_decl (pbdata->bounds_parm))
3668 assign_parm_setup_reg (&all, pbdata->bounds_parm,
3669 &pbdata->parm_data);
3670 else
3671 assign_parm_setup_stack (&all, pbdata->bounds_parm,
3672 &pbdata->parm_data);
3676 /* Assign RTL expressions to the function's parameters. This may involve
3677 copying them into registers and using those registers as the DECL_RTL. */
3679 static void
3680 assign_parms (tree fndecl)
3682 struct assign_parm_data_all all;
3683 tree parm;
3684 vec<tree> fnargs;
3685 unsigned i, bound_no = 0;
3686 tree last_arg = NULL;
3687 rtx last_arg_entry = NULL;
3688 vec<bounds_parm_data> bndargs = vNULL;
3689 bounds_parm_data bdata;
3691 crtl->args.internal_arg_pointer
3692 = targetm.calls.internal_arg_pointer ();
3694 assign_parms_initialize_all (&all);
3695 fnargs = assign_parms_augmented_arg_list (&all);
3697 FOR_EACH_VEC_ELT (fnargs, i, parm)
3699 struct assign_parm_data_one data;
3701 /* Extract the type of PARM; adjust it according to ABI. */
3702 assign_parm_find_data_types (&all, parm, &data);
3704 /* Early out for errors and void parameters. */
3705 if (data.passed_mode == VOIDmode)
3707 SET_DECL_RTL (parm, const0_rtx);
3708 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
3709 continue;
3712 /* Estimate stack alignment from parameter alignment. */
3713 if (SUPPORTS_STACK_ALIGNMENT)
3715 unsigned int align
3716 = targetm.calls.function_arg_boundary (data.promoted_mode,
3717 data.passed_type);
3718 align = MINIMUM_ALIGNMENT (data.passed_type, data.promoted_mode,
3719 align);
3720 if (TYPE_ALIGN (data.nominal_type) > align)
3721 align = MINIMUM_ALIGNMENT (data.nominal_type,
3722 TYPE_MODE (data.nominal_type),
3723 TYPE_ALIGN (data.nominal_type));
3724 if (crtl->stack_alignment_estimated < align)
3726 gcc_assert (!crtl->stack_realign_processed);
3727 crtl->stack_alignment_estimated = align;
3731 /* Find out where the parameter arrives in this function. */
3732 assign_parm_find_entry_rtl (&all, &data);
3734 /* Find out where stack space for this parameter might be. */
3735 if (assign_parm_is_stack_parm (&all, &data))
3737 assign_parm_find_stack_rtl (parm, &data);
3738 assign_parm_adjust_entry_rtl (&data);
3740 if (!POINTER_BOUNDS_TYPE_P (data.passed_type))
3742 /* Remember where last non bounds arg was passed in case
3743 we have to load associated bounds for it from Bounds
3744 Table. */
3745 last_arg = parm;
3746 last_arg_entry = data.entry_parm;
3747 bound_no = 0;
3749 /* Record permanently how this parm was passed. */
3750 if (data.passed_pointer)
3752 rtx incoming_rtl
3753 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data.passed_type)),
3754 data.entry_parm);
3755 set_decl_incoming_rtl (parm, incoming_rtl, true);
3757 else
3758 set_decl_incoming_rtl (parm, data.entry_parm, false);
3760 assign_parm_adjust_stack_rtl (&data);
3762 /* Bounds should be loaded in the particular order to
3763 have registers allocated correctly. Collect info about
3764 input bounds and load them later. */
3765 if (POINTER_BOUNDS_TYPE_P (data.passed_type))
3767 /* Expect bounds in instrumented functions only. */
3768 gcc_assert (chkp_function_instrumented_p (fndecl));
3770 bdata.parm_data = data;
3771 bdata.bounds_parm = parm;
3772 bdata.ptr_parm = last_arg;
3773 bdata.ptr_entry = last_arg_entry;
3774 bdata.bound_no = bound_no;
3775 bndargs.safe_push (bdata);
3777 else
3779 if (assign_parm_setup_block_p (&data))
3780 assign_parm_setup_block (&all, parm, &data);
3781 else if (data.passed_pointer || use_register_for_decl (parm))
3782 assign_parm_setup_reg (&all, parm, &data);
3783 else
3784 assign_parm_setup_stack (&all, parm, &data);
3787 if (cfun->stdarg && !DECL_CHAIN (parm))
3789 int pretend_bytes = 0;
3791 assign_parms_setup_varargs (&all, &data, false);
3793 if (chkp_function_instrumented_p (fndecl))
3795 /* We expect this is the last parm. Otherwise it is wrong
3796 to assign bounds right now. */
3797 gcc_assert (i == (fnargs.length () - 1));
3798 assign_bounds (bndargs, all, true, false, false);
3799 targetm.calls.setup_incoming_vararg_bounds (all.args_so_far,
3800 data.promoted_mode,
3801 data.passed_type,
3802 &pretend_bytes,
3803 false);
3804 assign_bounds (bndargs, all, false, true, true);
3805 bndargs.release ();
3809 /* Update info on where next arg arrives in registers. */
3810 targetm.calls.function_arg_advance (all.args_so_far, data.promoted_mode,
3811 data.passed_type, data.named_arg);
3813 if (POINTER_BOUNDS_TYPE_P (data.passed_type))
3814 bound_no++;
3817 assign_bounds (bndargs, all, true, true, true);
3818 bndargs.release ();
3820 if (targetm.calls.split_complex_arg)
3821 assign_parms_unsplit_complex (&all, fnargs);
3823 fnargs.release ();
3825 /* Output all parameter conversion instructions (possibly including calls)
3826 now that all parameters have been copied out of hard registers. */
3827 emit_insn (all.first_conversion_insn);
3829 /* Estimate reload stack alignment from scalar return mode. */
3830 if (SUPPORTS_STACK_ALIGNMENT)
3832 if (DECL_RESULT (fndecl))
3834 tree type = TREE_TYPE (DECL_RESULT (fndecl));
3835 machine_mode mode = TYPE_MODE (type);
3837 if (mode != BLKmode
3838 && mode != VOIDmode
3839 && !AGGREGATE_TYPE_P (type))
3841 unsigned int align = GET_MODE_ALIGNMENT (mode);
3842 if (crtl->stack_alignment_estimated < align)
3844 gcc_assert (!crtl->stack_realign_processed);
3845 crtl->stack_alignment_estimated = align;
3851 /* If we are receiving a struct value address as the first argument, set up
3852 the RTL for the function result. As this might require code to convert
3853 the transmitted address to Pmode, we do this here to ensure that possible
3854 preliminary conversions of the address have been emitted already. */
3855 if (all.function_result_decl)
3857 tree result = DECL_RESULT (current_function_decl);
3858 rtx addr = DECL_RTL (all.function_result_decl);
3859 rtx x;
3861 if (DECL_BY_REFERENCE (result))
3863 SET_DECL_VALUE_EXPR (result, all.function_result_decl);
3864 x = addr;
3866 else
3868 SET_DECL_VALUE_EXPR (result,
3869 build1 (INDIRECT_REF, TREE_TYPE (result),
3870 all.function_result_decl));
3871 addr = convert_memory_address (Pmode, addr);
3872 x = gen_rtx_MEM (DECL_MODE (result), addr);
3873 set_mem_attributes (x, result, 1);
3876 DECL_HAS_VALUE_EXPR_P (result) = 1;
3878 set_parm_rtl (result, x);
3881 /* We have aligned all the args, so add space for the pretend args. */
3882 crtl->args.pretend_args_size = all.pretend_args_size;
3883 all.stack_args_size.constant += all.extra_pretend_bytes;
3884 crtl->args.size = all.stack_args_size.constant;
3886 /* Adjust function incoming argument size for alignment and
3887 minimum length. */
3889 crtl->args.size = MAX (crtl->args.size, all.reg_parm_stack_space);
3890 crtl->args.size = CEIL_ROUND (crtl->args.size,
3891 PARM_BOUNDARY / BITS_PER_UNIT);
3893 if (ARGS_GROW_DOWNWARD)
3895 crtl->args.arg_offset_rtx
3896 = (all.stack_args_size.var == 0 ? GEN_INT (-all.stack_args_size.constant)
3897 : expand_expr (size_diffop (all.stack_args_size.var,
3898 size_int (-all.stack_args_size.constant)),
3899 NULL_RTX, VOIDmode, EXPAND_NORMAL));
3901 else
3902 crtl->args.arg_offset_rtx = ARGS_SIZE_RTX (all.stack_args_size);
3904 /* See how many bytes, if any, of its args a function should try to pop
3905 on return. */
3907 crtl->args.pops_args = targetm.calls.return_pops_args (fndecl,
3908 TREE_TYPE (fndecl),
3909 crtl->args.size);
3911 /* For stdarg.h function, save info about
3912 regs and stack space used by the named args. */
3914 crtl->args.info = all.args_so_far_v;
3916 /* Set the rtx used for the function return value. Put this in its
3917 own variable so any optimizers that need this information don't have
3918 to include tree.h. Do this here so it gets done when an inlined
3919 function gets output. */
3921 crtl->return_rtx
3922 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
3923 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
3925 /* If scalar return value was computed in a pseudo-reg, or was a named
3926 return value that got dumped to the stack, copy that to the hard
3927 return register. */
3928 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
3930 tree decl_result = DECL_RESULT (fndecl);
3931 rtx decl_rtl = DECL_RTL (decl_result);
3933 if (REG_P (decl_rtl)
3934 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
3935 : DECL_REGISTER (decl_result))
3937 rtx real_decl_rtl;
3939 real_decl_rtl = targetm.calls.function_value (TREE_TYPE (decl_result),
3940 fndecl, true);
3941 if (chkp_function_instrumented_p (fndecl))
3942 crtl->return_bnd
3943 = targetm.calls.chkp_function_value_bounds (TREE_TYPE (decl_result),
3944 fndecl, true);
3945 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
3946 /* The delay slot scheduler assumes that crtl->return_rtx
3947 holds the hard register containing the return value, not a
3948 temporary pseudo. */
3949 crtl->return_rtx = real_decl_rtl;
3954 /* A subroutine of gimplify_parameters, invoked via walk_tree.
3955 For all seen types, gimplify their sizes. */
3957 static tree
3958 gimplify_parm_type (tree *tp, int *walk_subtrees, void *data)
3960 tree t = *tp;
3962 *walk_subtrees = 0;
3963 if (TYPE_P (t))
3965 if (POINTER_TYPE_P (t))
3966 *walk_subtrees = 1;
3967 else if (TYPE_SIZE (t) && !TREE_CONSTANT (TYPE_SIZE (t))
3968 && !TYPE_SIZES_GIMPLIFIED (t))
3970 gimplify_type_sizes (t, (gimple_seq *) data);
3971 *walk_subtrees = 1;
3975 return NULL;
3978 /* Gimplify the parameter list for current_function_decl. This involves
3979 evaluating SAVE_EXPRs of variable sized parameters and generating code
3980 to implement callee-copies reference parameters. Returns a sequence of
3981 statements to add to the beginning of the function. */
3983 gimple_seq
3984 gimplify_parameters (void)
3986 struct assign_parm_data_all all;
3987 tree parm;
3988 gimple_seq stmts = NULL;
3989 vec<tree> fnargs;
3990 unsigned i;
3992 assign_parms_initialize_all (&all);
3993 fnargs = assign_parms_augmented_arg_list (&all);
3995 FOR_EACH_VEC_ELT (fnargs, i, parm)
3997 struct assign_parm_data_one data;
3999 /* Extract the type of PARM; adjust it according to ABI. */
4000 assign_parm_find_data_types (&all, parm, &data);
4002 /* Early out for errors and void parameters. */
4003 if (data.passed_mode == VOIDmode || DECL_SIZE (parm) == NULL)
4004 continue;
4006 /* Update info on where next arg arrives in registers. */
4007 targetm.calls.function_arg_advance (all.args_so_far, data.promoted_mode,
4008 data.passed_type, data.named_arg);
4010 /* ??? Once upon a time variable_size stuffed parameter list
4011 SAVE_EXPRs (amongst others) onto a pending sizes list. This
4012 turned out to be less than manageable in the gimple world.
4013 Now we have to hunt them down ourselves. */
4014 walk_tree_without_duplicates (&data.passed_type,
4015 gimplify_parm_type, &stmts);
4017 if (TREE_CODE (DECL_SIZE_UNIT (parm)) != INTEGER_CST)
4019 gimplify_one_sizepos (&DECL_SIZE (parm), &stmts);
4020 gimplify_one_sizepos (&DECL_SIZE_UNIT (parm), &stmts);
4023 if (data.passed_pointer)
4025 tree type = TREE_TYPE (data.passed_type);
4026 if (reference_callee_copied (&all.args_so_far_v, TYPE_MODE (type),
4027 type, data.named_arg))
4029 tree local, t;
4031 /* For constant-sized objects, this is trivial; for
4032 variable-sized objects, we have to play games. */
4033 if (TREE_CODE (DECL_SIZE_UNIT (parm)) == INTEGER_CST
4034 && !(flag_stack_check == GENERIC_STACK_CHECK
4035 && compare_tree_int (DECL_SIZE_UNIT (parm),
4036 STACK_CHECK_MAX_VAR_SIZE) > 0))
4038 local = create_tmp_var (type, get_name (parm));
4039 DECL_IGNORED_P (local) = 0;
4040 /* If PARM was addressable, move that flag over
4041 to the local copy, as its address will be taken,
4042 not the PARMs. Keep the parms address taken
4043 as we'll query that flag during gimplification. */
4044 if (TREE_ADDRESSABLE (parm))
4045 TREE_ADDRESSABLE (local) = 1;
4046 else if (TREE_CODE (type) == COMPLEX_TYPE
4047 || TREE_CODE (type) == VECTOR_TYPE)
4048 DECL_GIMPLE_REG_P (local) = 1;
4050 else
4052 tree ptr_type, addr;
4054 ptr_type = build_pointer_type (type);
4055 addr = create_tmp_reg (ptr_type, get_name (parm));
4056 DECL_IGNORED_P (addr) = 0;
4057 local = build_fold_indirect_ref (addr);
4059 t = build_alloca_call_expr (DECL_SIZE_UNIT (parm),
4060 DECL_ALIGN (parm),
4061 max_int_size_in_bytes (type));
4062 /* The call has been built for a variable-sized object. */
4063 CALL_ALLOCA_FOR_VAR_P (t) = 1;
4064 t = fold_convert (ptr_type, t);
4065 t = build2 (MODIFY_EXPR, TREE_TYPE (addr), addr, t);
4066 gimplify_and_add (t, &stmts);
4069 gimplify_assign (local, parm, &stmts);
4071 SET_DECL_VALUE_EXPR (parm, local);
4072 DECL_HAS_VALUE_EXPR_P (parm) = 1;
4077 fnargs.release ();
4079 return stmts;
4082 /* Compute the size and offset from the start of the stacked arguments for a
4083 parm passed in mode PASSED_MODE and with type TYPE.
4085 INITIAL_OFFSET_PTR points to the current offset into the stacked
4086 arguments.
4088 The starting offset and size for this parm are returned in
4089 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
4090 nonzero, the offset is that of stack slot, which is returned in
4091 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
4092 padding required from the initial offset ptr to the stack slot.
4094 IN_REGS is nonzero if the argument will be passed in registers. It will
4095 never be set if REG_PARM_STACK_SPACE is not defined.
4097 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
4098 for arguments which are passed in registers.
4100 FNDECL is the function in which the argument was defined.
4102 There are two types of rounding that are done. The first, controlled by
4103 TARGET_FUNCTION_ARG_BOUNDARY, forces the offset from the start of the
4104 argument list to be aligned to the specific boundary (in bits). This
4105 rounding affects the initial and starting offsets, but not the argument
4106 size.
4108 The second, controlled by TARGET_FUNCTION_ARG_PADDING and PARM_BOUNDARY,
4109 optionally rounds the size of the parm to PARM_BOUNDARY. The
4110 initial offset is not affected by this rounding, while the size always
4111 is and the starting offset may be. */
4113 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
4114 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
4115 callers pass in the total size of args so far as
4116 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
4118 void
4119 locate_and_pad_parm (machine_mode passed_mode, tree type, int in_regs,
4120 int reg_parm_stack_space, int partial,
4121 tree fndecl ATTRIBUTE_UNUSED,
4122 struct args_size *initial_offset_ptr,
4123 struct locate_and_pad_arg_data *locate)
4125 tree sizetree;
4126 pad_direction where_pad;
4127 unsigned int boundary, round_boundary;
4128 int part_size_in_regs;
4130 /* If we have found a stack parm before we reach the end of the
4131 area reserved for registers, skip that area. */
4132 if (! in_regs)
4134 if (reg_parm_stack_space > 0)
4136 if (initial_offset_ptr->var)
4138 initial_offset_ptr->var
4139 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
4140 ssize_int (reg_parm_stack_space));
4141 initial_offset_ptr->constant = 0;
4143 else if (initial_offset_ptr->constant < reg_parm_stack_space)
4144 initial_offset_ptr->constant = reg_parm_stack_space;
4148 part_size_in_regs = (reg_parm_stack_space == 0 ? partial : 0);
4150 sizetree = (type
4151 ? arg_size_in_bytes (type)
4152 : size_int (GET_MODE_SIZE (passed_mode)));
4153 where_pad = targetm.calls.function_arg_padding (passed_mode, type);
4154 boundary = targetm.calls.function_arg_boundary (passed_mode, type);
4155 round_boundary = targetm.calls.function_arg_round_boundary (passed_mode,
4156 type);
4157 locate->where_pad = where_pad;
4159 /* Alignment can't exceed MAX_SUPPORTED_STACK_ALIGNMENT. */
4160 if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
4161 boundary = MAX_SUPPORTED_STACK_ALIGNMENT;
4163 locate->boundary = boundary;
4165 if (SUPPORTS_STACK_ALIGNMENT)
4167 /* stack_alignment_estimated can't change after stack has been
4168 realigned. */
4169 if (crtl->stack_alignment_estimated < boundary)
4171 if (!crtl->stack_realign_processed)
4172 crtl->stack_alignment_estimated = boundary;
4173 else
4175 /* If stack is realigned and stack alignment value
4176 hasn't been finalized, it is OK not to increase
4177 stack_alignment_estimated. The bigger alignment
4178 requirement is recorded in stack_alignment_needed
4179 below. */
4180 gcc_assert (!crtl->stack_realign_finalized
4181 && crtl->stack_realign_needed);
4186 /* Remember if the outgoing parameter requires extra alignment on the
4187 calling function side. */
4188 if (crtl->stack_alignment_needed < boundary)
4189 crtl->stack_alignment_needed = boundary;
4190 if (crtl->preferred_stack_boundary < boundary)
4191 crtl->preferred_stack_boundary = boundary;
4193 if (ARGS_GROW_DOWNWARD)
4195 locate->slot_offset.constant = -initial_offset_ptr->constant;
4196 if (initial_offset_ptr->var)
4197 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
4198 initial_offset_ptr->var);
4201 tree s2 = sizetree;
4202 if (where_pad != PAD_NONE
4203 && (!tree_fits_uhwi_p (sizetree)
4204 || (tree_to_uhwi (sizetree) * BITS_PER_UNIT) % round_boundary))
4205 s2 = round_up (s2, round_boundary / BITS_PER_UNIT);
4206 SUB_PARM_SIZE (locate->slot_offset, s2);
4209 locate->slot_offset.constant += part_size_in_regs;
4211 if (!in_regs || reg_parm_stack_space > 0)
4212 pad_to_arg_alignment (&locate->slot_offset, boundary,
4213 &locate->alignment_pad);
4215 locate->size.constant = (-initial_offset_ptr->constant
4216 - locate->slot_offset.constant);
4217 if (initial_offset_ptr->var)
4218 locate->size.var = size_binop (MINUS_EXPR,
4219 size_binop (MINUS_EXPR,
4220 ssize_int (0),
4221 initial_offset_ptr->var),
4222 locate->slot_offset.var);
4224 /* Pad_below needs the pre-rounded size to know how much to pad
4225 below. */
4226 locate->offset = locate->slot_offset;
4227 if (where_pad == PAD_DOWNWARD)
4228 pad_below (&locate->offset, passed_mode, sizetree);
4231 else
4233 if (!in_regs || reg_parm_stack_space > 0)
4234 pad_to_arg_alignment (initial_offset_ptr, boundary,
4235 &locate->alignment_pad);
4236 locate->slot_offset = *initial_offset_ptr;
4238 #ifdef PUSH_ROUNDING
4239 if (passed_mode != BLKmode)
4240 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
4241 #endif
4243 /* Pad_below needs the pre-rounded size to know how much to pad below
4244 so this must be done before rounding up. */
4245 locate->offset = locate->slot_offset;
4246 if (where_pad == PAD_DOWNWARD)
4247 pad_below (&locate->offset, passed_mode, sizetree);
4249 if (where_pad != PAD_NONE
4250 && (!tree_fits_uhwi_p (sizetree)
4251 || (tree_to_uhwi (sizetree) * BITS_PER_UNIT) % round_boundary))
4252 sizetree = round_up (sizetree, round_boundary / BITS_PER_UNIT);
4254 ADD_PARM_SIZE (locate->size, sizetree);
4256 locate->size.constant -= part_size_in_regs;
4259 locate->offset.constant
4260 += targetm.calls.function_arg_offset (passed_mode, type);
4263 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
4264 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
4266 static void
4267 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
4268 struct args_size *alignment_pad)
4270 tree save_var = NULL_TREE;
4271 HOST_WIDE_INT save_constant = 0;
4272 int boundary_in_bytes = boundary / BITS_PER_UNIT;
4273 HOST_WIDE_INT sp_offset = STACK_POINTER_OFFSET;
4275 #ifdef SPARC_STACK_BOUNDARY_HACK
4276 /* ??? The SPARC port may claim a STACK_BOUNDARY higher than
4277 the real alignment of %sp. However, when it does this, the
4278 alignment of %sp+STACK_POINTER_OFFSET is STACK_BOUNDARY. */
4279 if (SPARC_STACK_BOUNDARY_HACK)
4280 sp_offset = 0;
4281 #endif
4283 if (boundary > PARM_BOUNDARY)
4285 save_var = offset_ptr->var;
4286 save_constant = offset_ptr->constant;
4289 alignment_pad->var = NULL_TREE;
4290 alignment_pad->constant = 0;
4292 if (boundary > BITS_PER_UNIT)
4294 if (offset_ptr->var)
4296 tree sp_offset_tree = ssize_int (sp_offset);
4297 tree offset = size_binop (PLUS_EXPR,
4298 ARGS_SIZE_TREE (*offset_ptr),
4299 sp_offset_tree);
4300 tree rounded;
4301 if (ARGS_GROW_DOWNWARD)
4302 rounded = round_down (offset, boundary / BITS_PER_UNIT);
4303 else
4304 rounded = round_up (offset, boundary / BITS_PER_UNIT);
4306 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
4307 /* ARGS_SIZE_TREE includes constant term. */
4308 offset_ptr->constant = 0;
4309 if (boundary > PARM_BOUNDARY)
4310 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
4311 save_var);
4313 else
4315 offset_ptr->constant = -sp_offset +
4316 (ARGS_GROW_DOWNWARD
4317 ? FLOOR_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes)
4318 : CEIL_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes));
4320 if (boundary > PARM_BOUNDARY)
4321 alignment_pad->constant = offset_ptr->constant - save_constant;
4326 static void
4327 pad_below (struct args_size *offset_ptr, machine_mode passed_mode, tree sizetree)
4329 unsigned int align = PARM_BOUNDARY / BITS_PER_UNIT;
4330 if (passed_mode != BLKmode)
4331 offset_ptr->constant += -GET_MODE_SIZE (passed_mode) & (align - 1);
4332 else
4334 if (TREE_CODE (sizetree) != INTEGER_CST
4335 || (TREE_INT_CST_LOW (sizetree) & (align - 1)) != 0)
4337 /* Round the size up to multiple of PARM_BOUNDARY bits. */
4338 tree s2 = round_up (sizetree, align);
4339 /* Add it in. */
4340 ADD_PARM_SIZE (*offset_ptr, s2);
4341 SUB_PARM_SIZE (*offset_ptr, sizetree);
4347 /* True if register REGNO was alive at a place where `setjmp' was
4348 called and was set more than once or is an argument. Such regs may
4349 be clobbered by `longjmp'. */
4351 static bool
4352 regno_clobbered_at_setjmp (bitmap setjmp_crosses, int regno)
4354 /* There appear to be cases where some local vars never reach the
4355 backend but have bogus regnos. */
4356 if (regno >= max_reg_num ())
4357 return false;
4359 return ((REG_N_SETS (regno) > 1
4360 || REGNO_REG_SET_P (df_get_live_out (ENTRY_BLOCK_PTR_FOR_FN (cfun)),
4361 regno))
4362 && REGNO_REG_SET_P (setjmp_crosses, regno));
4365 /* Walk the tree of blocks describing the binding levels within a
4366 function and warn about variables the might be killed by setjmp or
4367 vfork. This is done after calling flow_analysis before register
4368 allocation since that will clobber the pseudo-regs to hard
4369 regs. */
4371 static void
4372 setjmp_vars_warning (bitmap setjmp_crosses, tree block)
4374 tree decl, sub;
4376 for (decl = BLOCK_VARS (block); decl; decl = DECL_CHAIN (decl))
4378 if (VAR_P (decl)
4379 && DECL_RTL_SET_P (decl)
4380 && REG_P (DECL_RTL (decl))
4381 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
4382 warning (OPT_Wclobbered, "variable %q+D might be clobbered by"
4383 " %<longjmp%> or %<vfork%>", decl);
4386 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = BLOCK_CHAIN (sub))
4387 setjmp_vars_warning (setjmp_crosses, sub);
4390 /* Do the appropriate part of setjmp_vars_warning
4391 but for arguments instead of local variables. */
4393 static void
4394 setjmp_args_warning (bitmap setjmp_crosses)
4396 tree decl;
4397 for (decl = DECL_ARGUMENTS (current_function_decl);
4398 decl; decl = DECL_CHAIN (decl))
4399 if (DECL_RTL (decl) != 0
4400 && REG_P (DECL_RTL (decl))
4401 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
4402 warning (OPT_Wclobbered,
4403 "argument %q+D might be clobbered by %<longjmp%> or %<vfork%>",
4404 decl);
4407 /* Generate warning messages for variables live across setjmp. */
4409 void
4410 generate_setjmp_warnings (void)
4412 bitmap setjmp_crosses = regstat_get_setjmp_crosses ();
4414 if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS
4415 || bitmap_empty_p (setjmp_crosses))
4416 return;
4418 setjmp_vars_warning (setjmp_crosses, DECL_INITIAL (current_function_decl));
4419 setjmp_args_warning (setjmp_crosses);
4423 /* Reverse the order of elements in the fragment chain T of blocks,
4424 and return the new head of the chain (old last element).
4425 In addition to that clear BLOCK_SAME_RANGE flags when needed
4426 and adjust BLOCK_SUPERCONTEXT from the super fragment to
4427 its super fragment origin. */
4429 static tree
4430 block_fragments_nreverse (tree t)
4432 tree prev = 0, block, next, prev_super = 0;
4433 tree super = BLOCK_SUPERCONTEXT (t);
4434 if (BLOCK_FRAGMENT_ORIGIN (super))
4435 super = BLOCK_FRAGMENT_ORIGIN (super);
4436 for (block = t; block; block = next)
4438 next = BLOCK_FRAGMENT_CHAIN (block);
4439 BLOCK_FRAGMENT_CHAIN (block) = prev;
4440 if ((prev && !BLOCK_SAME_RANGE (prev))
4441 || (BLOCK_FRAGMENT_CHAIN (BLOCK_SUPERCONTEXT (block))
4442 != prev_super))
4443 BLOCK_SAME_RANGE (block) = 0;
4444 prev_super = BLOCK_SUPERCONTEXT (block);
4445 BLOCK_SUPERCONTEXT (block) = super;
4446 prev = block;
4448 t = BLOCK_FRAGMENT_ORIGIN (t);
4449 if (BLOCK_FRAGMENT_CHAIN (BLOCK_SUPERCONTEXT (t))
4450 != prev_super)
4451 BLOCK_SAME_RANGE (t) = 0;
4452 BLOCK_SUPERCONTEXT (t) = super;
4453 return prev;
4456 /* Reverse the order of elements in the chain T of blocks,
4457 and return the new head of the chain (old last element).
4458 Also do the same on subblocks and reverse the order of elements
4459 in BLOCK_FRAGMENT_CHAIN as well. */
4461 static tree
4462 blocks_nreverse_all (tree t)
4464 tree prev = 0, block, next;
4465 for (block = t; block; block = next)
4467 next = BLOCK_CHAIN (block);
4468 BLOCK_CHAIN (block) = prev;
4469 if (BLOCK_FRAGMENT_CHAIN (block)
4470 && BLOCK_FRAGMENT_ORIGIN (block) == NULL_TREE)
4472 BLOCK_FRAGMENT_CHAIN (block)
4473 = block_fragments_nreverse (BLOCK_FRAGMENT_CHAIN (block));
4474 if (!BLOCK_SAME_RANGE (BLOCK_FRAGMENT_CHAIN (block)))
4475 BLOCK_SAME_RANGE (block) = 0;
4477 BLOCK_SUBBLOCKS (block) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block));
4478 prev = block;
4480 return prev;
4484 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
4485 and create duplicate blocks. */
4486 /* ??? Need an option to either create block fragments or to create
4487 abstract origin duplicates of a source block. It really depends
4488 on what optimization has been performed. */
4490 void
4491 reorder_blocks (void)
4493 tree block = DECL_INITIAL (current_function_decl);
4495 if (block == NULL_TREE)
4496 return;
4498 auto_vec<tree, 10> block_stack;
4500 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
4501 clear_block_marks (block);
4503 /* Prune the old trees away, so that they don't get in the way. */
4504 BLOCK_SUBBLOCKS (block) = NULL_TREE;
4505 BLOCK_CHAIN (block) = NULL_TREE;
4507 /* Recreate the block tree from the note nesting. */
4508 reorder_blocks_1 (get_insns (), block, &block_stack);
4509 BLOCK_SUBBLOCKS (block) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block));
4512 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
4514 void
4515 clear_block_marks (tree block)
4517 while (block)
4519 TREE_ASM_WRITTEN (block) = 0;
4520 clear_block_marks (BLOCK_SUBBLOCKS (block));
4521 block = BLOCK_CHAIN (block);
4525 static void
4526 reorder_blocks_1 (rtx_insn *insns, tree current_block,
4527 vec<tree> *p_block_stack)
4529 rtx_insn *insn;
4530 tree prev_beg = NULL_TREE, prev_end = NULL_TREE;
4532 for (insn = insns; insn; insn = NEXT_INSN (insn))
4534 if (NOTE_P (insn))
4536 if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_BEG)
4538 tree block = NOTE_BLOCK (insn);
4539 tree origin;
4541 gcc_assert (BLOCK_FRAGMENT_ORIGIN (block) == NULL_TREE);
4542 origin = block;
4544 if (prev_end)
4545 BLOCK_SAME_RANGE (prev_end) = 0;
4546 prev_end = NULL_TREE;
4548 /* If we have seen this block before, that means it now
4549 spans multiple address regions. Create a new fragment. */
4550 if (TREE_ASM_WRITTEN (block))
4552 tree new_block = copy_node (block);
4554 BLOCK_SAME_RANGE (new_block) = 0;
4555 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
4556 BLOCK_FRAGMENT_CHAIN (new_block)
4557 = BLOCK_FRAGMENT_CHAIN (origin);
4558 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
4560 NOTE_BLOCK (insn) = new_block;
4561 block = new_block;
4564 if (prev_beg == current_block && prev_beg)
4565 BLOCK_SAME_RANGE (block) = 1;
4567 prev_beg = origin;
4569 BLOCK_SUBBLOCKS (block) = 0;
4570 TREE_ASM_WRITTEN (block) = 1;
4571 /* When there's only one block for the entire function,
4572 current_block == block and we mustn't do this, it
4573 will cause infinite recursion. */
4574 if (block != current_block)
4576 tree super;
4577 if (block != origin)
4578 gcc_assert (BLOCK_SUPERCONTEXT (origin) == current_block
4579 || BLOCK_FRAGMENT_ORIGIN (BLOCK_SUPERCONTEXT
4580 (origin))
4581 == current_block);
4582 if (p_block_stack->is_empty ())
4583 super = current_block;
4584 else
4586 super = p_block_stack->last ();
4587 gcc_assert (super == current_block
4588 || BLOCK_FRAGMENT_ORIGIN (super)
4589 == current_block);
4591 BLOCK_SUPERCONTEXT (block) = super;
4592 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
4593 BLOCK_SUBBLOCKS (current_block) = block;
4594 current_block = origin;
4596 p_block_stack->safe_push (block);
4598 else if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_END)
4600 NOTE_BLOCK (insn) = p_block_stack->pop ();
4601 current_block = BLOCK_SUPERCONTEXT (current_block);
4602 if (BLOCK_FRAGMENT_ORIGIN (current_block))
4603 current_block = BLOCK_FRAGMENT_ORIGIN (current_block);
4604 prev_beg = NULL_TREE;
4605 prev_end = BLOCK_SAME_RANGE (NOTE_BLOCK (insn))
4606 ? NOTE_BLOCK (insn) : NULL_TREE;
4609 else
4611 prev_beg = NULL_TREE;
4612 if (prev_end)
4613 BLOCK_SAME_RANGE (prev_end) = 0;
4614 prev_end = NULL_TREE;
4619 /* Reverse the order of elements in the chain T of blocks,
4620 and return the new head of the chain (old last element). */
4622 tree
4623 blocks_nreverse (tree t)
4625 tree prev = 0, block, next;
4626 for (block = t; block; block = next)
4628 next = BLOCK_CHAIN (block);
4629 BLOCK_CHAIN (block) = prev;
4630 prev = block;
4632 return prev;
4635 /* Concatenate two chains of blocks (chained through BLOCK_CHAIN)
4636 by modifying the last node in chain 1 to point to chain 2. */
4638 tree
4639 block_chainon (tree op1, tree op2)
4641 tree t1;
4643 if (!op1)
4644 return op2;
4645 if (!op2)
4646 return op1;
4648 for (t1 = op1; BLOCK_CHAIN (t1); t1 = BLOCK_CHAIN (t1))
4649 continue;
4650 BLOCK_CHAIN (t1) = op2;
4652 #ifdef ENABLE_TREE_CHECKING
4654 tree t2;
4655 for (t2 = op2; t2; t2 = BLOCK_CHAIN (t2))
4656 gcc_assert (t2 != t1);
4658 #endif
4660 return op1;
4663 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
4664 non-NULL, list them all into VECTOR, in a depth-first preorder
4665 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
4666 blocks. */
4668 static int
4669 all_blocks (tree block, tree *vector)
4671 int n_blocks = 0;
4673 while (block)
4675 TREE_ASM_WRITTEN (block) = 0;
4677 /* Record this block. */
4678 if (vector)
4679 vector[n_blocks] = block;
4681 ++n_blocks;
4683 /* Record the subblocks, and their subblocks... */
4684 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
4685 vector ? vector + n_blocks : 0);
4686 block = BLOCK_CHAIN (block);
4689 return n_blocks;
4692 /* Return a vector containing all the blocks rooted at BLOCK. The
4693 number of elements in the vector is stored in N_BLOCKS_P. The
4694 vector is dynamically allocated; it is the caller's responsibility
4695 to call `free' on the pointer returned. */
4697 static tree *
4698 get_block_vector (tree block, int *n_blocks_p)
4700 tree *block_vector;
4702 *n_blocks_p = all_blocks (block, NULL);
4703 block_vector = XNEWVEC (tree, *n_blocks_p);
4704 all_blocks (block, block_vector);
4706 return block_vector;
4709 static GTY(()) int next_block_index = 2;
4711 /* Set BLOCK_NUMBER for all the blocks in FN. */
4713 void
4714 number_blocks (tree fn)
4716 int i;
4717 int n_blocks;
4718 tree *block_vector;
4720 /* For XCOFF debugging output, we start numbering the blocks
4721 from 1 within each function, rather than keeping a running
4722 count. */
4723 #if defined (XCOFF_DEBUGGING_INFO)
4724 if (write_symbols == XCOFF_DEBUG)
4725 next_block_index = 1;
4726 #endif
4728 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
4730 /* The top-level BLOCK isn't numbered at all. */
4731 for (i = 1; i < n_blocks; ++i)
4732 /* We number the blocks from two. */
4733 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
4735 free (block_vector);
4737 return;
4740 /* If VAR is present in a subblock of BLOCK, return the subblock. */
4742 DEBUG_FUNCTION tree
4743 debug_find_var_in_block_tree (tree var, tree block)
4745 tree t;
4747 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
4748 if (t == var)
4749 return block;
4751 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
4753 tree ret = debug_find_var_in_block_tree (var, t);
4754 if (ret)
4755 return ret;
4758 return NULL_TREE;
4761 /* Keep track of whether we're in a dummy function context. If we are,
4762 we don't want to invoke the set_current_function hook, because we'll
4763 get into trouble if the hook calls target_reinit () recursively or
4764 when the initial initialization is not yet complete. */
4766 static bool in_dummy_function;
4768 /* Invoke the target hook when setting cfun. Update the optimization options
4769 if the function uses different options than the default. */
4771 static void
4772 invoke_set_current_function_hook (tree fndecl)
4774 if (!in_dummy_function)
4776 tree opts = ((fndecl)
4777 ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (fndecl)
4778 : optimization_default_node);
4780 if (!opts)
4781 opts = optimization_default_node;
4783 /* Change optimization options if needed. */
4784 if (optimization_current_node != opts)
4786 optimization_current_node = opts;
4787 cl_optimization_restore (&global_options, TREE_OPTIMIZATION (opts));
4790 targetm.set_current_function (fndecl);
4791 this_fn_optabs = this_target_optabs;
4793 if (opts != optimization_default_node)
4795 init_tree_optimization_optabs (opts);
4796 if (TREE_OPTIMIZATION_OPTABS (opts))
4797 this_fn_optabs = (struct target_optabs *)
4798 TREE_OPTIMIZATION_OPTABS (opts);
4803 /* cfun should never be set directly; use this function. */
4805 void
4806 set_cfun (struct function *new_cfun, bool force)
4808 if (cfun != new_cfun || force)
4810 cfun = new_cfun;
4811 invoke_set_current_function_hook (new_cfun ? new_cfun->decl : NULL_TREE);
4812 redirect_edge_var_map_empty ();
4816 /* Initialized with NOGC, making this poisonous to the garbage collector. */
4818 static vec<function *> cfun_stack;
4820 /* Push the current cfun onto the stack, and set cfun to new_cfun. Also set
4821 current_function_decl accordingly. */
4823 void
4824 push_cfun (struct function *new_cfun)
4826 gcc_assert ((!cfun && !current_function_decl)
4827 || (cfun && current_function_decl == cfun->decl));
4828 cfun_stack.safe_push (cfun);
4829 current_function_decl = new_cfun ? new_cfun->decl : NULL_TREE;
4830 set_cfun (new_cfun);
4833 /* Pop cfun from the stack. Also set current_function_decl accordingly. */
4835 void
4836 pop_cfun (void)
4838 struct function *new_cfun = cfun_stack.pop ();
4839 /* When in_dummy_function, we do have a cfun but current_function_decl is
4840 NULL. We also allow pushing NULL cfun and subsequently changing
4841 current_function_decl to something else and have both restored by
4842 pop_cfun. */
4843 gcc_checking_assert (in_dummy_function
4844 || !cfun
4845 || current_function_decl == cfun->decl);
4846 set_cfun (new_cfun);
4847 current_function_decl = new_cfun ? new_cfun->decl : NULL_TREE;
4850 /* Return value of funcdef and increase it. */
4852 get_next_funcdef_no (void)
4854 return funcdef_no++;
4857 /* Return value of funcdef. */
4859 get_last_funcdef_no (void)
4861 return funcdef_no;
4864 /* Allocate a function structure for FNDECL and set its contents
4865 to the defaults. Set cfun to the newly-allocated object.
4866 Some of the helper functions invoked during initialization assume
4867 that cfun has already been set. Therefore, assign the new object
4868 directly into cfun and invoke the back end hook explicitly at the
4869 very end, rather than initializing a temporary and calling set_cfun
4870 on it.
4872 ABSTRACT_P is true if this is a function that will never be seen by
4873 the middle-end. Such functions are front-end concepts (like C++
4874 function templates) that do not correspond directly to functions
4875 placed in object files. */
4877 void
4878 allocate_struct_function (tree fndecl, bool abstract_p)
4880 tree fntype = fndecl ? TREE_TYPE (fndecl) : NULL_TREE;
4882 cfun = ggc_cleared_alloc<function> ();
4884 init_eh_for_function ();
4886 if (init_machine_status)
4887 cfun->machine = (*init_machine_status) ();
4889 #ifdef OVERRIDE_ABI_FORMAT
4890 OVERRIDE_ABI_FORMAT (fndecl);
4891 #endif
4893 if (fndecl != NULL_TREE)
4895 DECL_STRUCT_FUNCTION (fndecl) = cfun;
4896 cfun->decl = fndecl;
4897 current_function_funcdef_no = get_next_funcdef_no ();
4900 invoke_set_current_function_hook (fndecl);
4902 if (fndecl != NULL_TREE)
4904 tree result = DECL_RESULT (fndecl);
4906 if (!abstract_p)
4908 /* Now that we have activated any function-specific attributes
4909 that might affect layout, particularly vector modes, relayout
4910 each of the parameters and the result. */
4911 relayout_decl (result);
4912 for (tree parm = DECL_ARGUMENTS (fndecl); parm;
4913 parm = DECL_CHAIN (parm))
4914 relayout_decl (parm);
4916 /* Similarly relayout the function decl. */
4917 targetm.target_option.relayout_function (fndecl);
4920 if (!abstract_p && aggregate_value_p (result, fndecl))
4922 #ifdef PCC_STATIC_STRUCT_RETURN
4923 cfun->returns_pcc_struct = 1;
4924 #endif
4925 cfun->returns_struct = 1;
4928 cfun->stdarg = stdarg_p (fntype);
4930 /* Assume all registers in stdarg functions need to be saved. */
4931 cfun->va_list_gpr_size = VA_LIST_MAX_GPR_SIZE;
4932 cfun->va_list_fpr_size = VA_LIST_MAX_FPR_SIZE;
4934 /* ??? This could be set on a per-function basis by the front-end
4935 but is this worth the hassle? */
4936 cfun->can_throw_non_call_exceptions = flag_non_call_exceptions;
4937 cfun->can_delete_dead_exceptions = flag_delete_dead_exceptions;
4939 if (!profile_flag && !flag_instrument_function_entry_exit)
4940 DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl) = 1;
4944 /* This is like allocate_struct_function, but pushes a new cfun for FNDECL
4945 instead of just setting it. */
4947 void
4948 push_struct_function (tree fndecl)
4950 /* When in_dummy_function we might be in the middle of a pop_cfun and
4951 current_function_decl and cfun may not match. */
4952 gcc_assert (in_dummy_function
4953 || (!cfun && !current_function_decl)
4954 || (cfun && current_function_decl == cfun->decl));
4955 cfun_stack.safe_push (cfun);
4956 current_function_decl = fndecl;
4957 allocate_struct_function (fndecl, false);
4960 /* Reset crtl and other non-struct-function variables to defaults as
4961 appropriate for emitting rtl at the start of a function. */
4963 static void
4964 prepare_function_start (void)
4966 gcc_assert (!get_last_insn ());
4967 init_temp_slots ();
4968 init_emit ();
4969 init_varasm_status ();
4970 init_expr ();
4971 default_rtl_profile ();
4973 if (flag_stack_usage_info)
4975 cfun->su = ggc_cleared_alloc<stack_usage> ();
4976 cfun->su->static_stack_size = -1;
4979 cse_not_expected = ! optimize;
4981 /* Caller save not needed yet. */
4982 caller_save_needed = 0;
4984 /* We haven't done register allocation yet. */
4985 reg_renumber = 0;
4987 /* Indicate that we have not instantiated virtual registers yet. */
4988 virtuals_instantiated = 0;
4990 /* Indicate that we want CONCATs now. */
4991 generating_concat_p = 1;
4993 /* Indicate we have no need of a frame pointer yet. */
4994 frame_pointer_needed = 0;
4997 void
4998 push_dummy_function (bool with_decl)
5000 tree fn_decl, fn_type, fn_result_decl;
5002 gcc_assert (!in_dummy_function);
5003 in_dummy_function = true;
5005 if (with_decl)
5007 fn_type = build_function_type_list (void_type_node, NULL_TREE);
5008 fn_decl = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL, NULL_TREE,
5009 fn_type);
5010 fn_result_decl = build_decl (UNKNOWN_LOCATION, RESULT_DECL,
5011 NULL_TREE, void_type_node);
5012 DECL_RESULT (fn_decl) = fn_result_decl;
5014 else
5015 fn_decl = NULL_TREE;
5017 push_struct_function (fn_decl);
5020 /* Initialize the rtl expansion mechanism so that we can do simple things
5021 like generate sequences. This is used to provide a context during global
5022 initialization of some passes. You must call expand_dummy_function_end
5023 to exit this context. */
5025 void
5026 init_dummy_function_start (void)
5028 push_dummy_function (false);
5029 prepare_function_start ();
5032 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
5033 and initialize static variables for generating RTL for the statements
5034 of the function. */
5036 void
5037 init_function_start (tree subr)
5039 /* Initialize backend, if needed. */
5040 initialize_rtl ();
5042 prepare_function_start ();
5043 decide_function_section (subr);
5045 /* Warn if this value is an aggregate type,
5046 regardless of which calling convention we are using for it. */
5047 if (AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
5048 warning (OPT_Waggregate_return, "function returns an aggregate");
5051 /* Expand code to verify the stack_protect_guard. This is invoked at
5052 the end of a function to be protected. */
5054 void
5055 stack_protect_epilogue (void)
5057 tree guard_decl = targetm.stack_protect_guard ();
5058 rtx_code_label *label = gen_label_rtx ();
5059 rtx x, y;
5060 rtx_insn *seq;
5062 x = expand_normal (crtl->stack_protect_guard);
5063 if (guard_decl)
5064 y = expand_normal (guard_decl);
5065 else
5066 y = const0_rtx;
5068 /* Allow the target to compare Y with X without leaking either into
5069 a register. */
5070 if (targetm.have_stack_protect_test ()
5071 && ((seq = targetm.gen_stack_protect_test (x, y, label)) != NULL_RTX))
5072 emit_insn (seq);
5073 else
5074 emit_cmp_and_jump_insns (x, y, EQ, NULL_RTX, ptr_mode, 1, label);
5076 /* The noreturn predictor has been moved to the tree level. The rtl-level
5077 predictors estimate this branch about 20%, which isn't enough to get
5078 things moved out of line. Since this is the only extant case of adding
5079 a noreturn function at the rtl level, it doesn't seem worth doing ought
5080 except adding the prediction by hand. */
5081 rtx_insn *tmp = get_last_insn ();
5082 if (JUMP_P (tmp))
5083 predict_insn_def (tmp, PRED_NORETURN, TAKEN);
5085 expand_call (targetm.stack_protect_fail (), NULL_RTX, /*ignore=*/true);
5086 free_temp_slots ();
5087 emit_label (label);
5090 /* Start the RTL for a new function, and set variables used for
5091 emitting RTL.
5092 SUBR is the FUNCTION_DECL node.
5093 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
5094 the function's parameters, which must be run at any return statement. */
5096 void
5097 expand_function_start (tree subr)
5099 /* Make sure volatile mem refs aren't considered
5100 valid operands of arithmetic insns. */
5101 init_recog_no_volatile ();
5103 crtl->profile
5104 = (profile_flag
5105 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
5107 crtl->limit_stack
5108 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
5110 /* Make the label for return statements to jump to. Do not special
5111 case machines with special return instructions -- they will be
5112 handled later during jump, ifcvt, or epilogue creation. */
5113 return_label = gen_label_rtx ();
5115 /* Initialize rtx used to return the value. */
5116 /* Do this before assign_parms so that we copy the struct value address
5117 before any library calls that assign parms might generate. */
5119 /* Decide whether to return the value in memory or in a register. */
5120 tree res = DECL_RESULT (subr);
5121 if (aggregate_value_p (res, subr))
5123 /* Returning something that won't go in a register. */
5124 rtx value_address = 0;
5126 #ifdef PCC_STATIC_STRUCT_RETURN
5127 if (cfun->returns_pcc_struct)
5129 int size = int_size_in_bytes (TREE_TYPE (res));
5130 value_address = assemble_static_space (size);
5132 else
5133 #endif
5135 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 2);
5136 /* Expect to be passed the address of a place to store the value.
5137 If it is passed as an argument, assign_parms will take care of
5138 it. */
5139 if (sv)
5141 value_address = gen_reg_rtx (Pmode);
5142 emit_move_insn (value_address, sv);
5145 if (value_address)
5147 rtx x = value_address;
5148 if (!DECL_BY_REFERENCE (res))
5150 x = gen_rtx_MEM (DECL_MODE (res), x);
5151 set_mem_attributes (x, res, 1);
5153 set_parm_rtl (res, x);
5156 else if (DECL_MODE (res) == VOIDmode)
5157 /* If return mode is void, this decl rtl should not be used. */
5158 set_parm_rtl (res, NULL_RTX);
5159 else
5161 /* Compute the return values into a pseudo reg, which we will copy
5162 into the true return register after the cleanups are done. */
5163 tree return_type = TREE_TYPE (res);
5165 /* If we may coalesce this result, make sure it has the expected mode
5166 in case it was promoted. But we need not bother about BLKmode. */
5167 machine_mode promoted_mode
5168 = flag_tree_coalesce_vars && is_gimple_reg (res)
5169 ? promote_ssa_mode (ssa_default_def (cfun, res), NULL)
5170 : BLKmode;
5172 if (promoted_mode != BLKmode)
5173 set_parm_rtl (res, gen_reg_rtx (promoted_mode));
5174 else if (TYPE_MODE (return_type) != BLKmode
5175 && targetm.calls.return_in_msb (return_type))
5176 /* expand_function_end will insert the appropriate padding in
5177 this case. Use the return value's natural (unpadded) mode
5178 within the function proper. */
5179 set_parm_rtl (res, gen_reg_rtx (TYPE_MODE (return_type)));
5180 else
5182 /* In order to figure out what mode to use for the pseudo, we
5183 figure out what the mode of the eventual return register will
5184 actually be, and use that. */
5185 rtx hard_reg = hard_function_value (return_type, subr, 0, 1);
5187 /* Structures that are returned in registers are not
5188 aggregate_value_p, so we may see a PARALLEL or a REG. */
5189 if (REG_P (hard_reg))
5190 set_parm_rtl (res, gen_reg_rtx (GET_MODE (hard_reg)));
5191 else
5193 gcc_assert (GET_CODE (hard_reg) == PARALLEL);
5194 set_parm_rtl (res, gen_group_rtx (hard_reg));
5198 /* Set DECL_REGISTER flag so that expand_function_end will copy the
5199 result to the real return register(s). */
5200 DECL_REGISTER (res) = 1;
5202 if (chkp_function_instrumented_p (current_function_decl))
5204 tree return_type = TREE_TYPE (res);
5205 rtx bounds = targetm.calls.chkp_function_value_bounds (return_type,
5206 subr, 1);
5207 SET_DECL_BOUNDS_RTL (res, bounds);
5211 /* Initialize rtx for parameters and local variables.
5212 In some cases this requires emitting insns. */
5213 assign_parms (subr);
5215 /* If function gets a static chain arg, store it. */
5216 if (cfun->static_chain_decl)
5218 tree parm = cfun->static_chain_decl;
5219 rtx local, chain;
5220 rtx_insn *insn;
5221 int unsignedp;
5223 local = gen_reg_rtx (promote_decl_mode (parm, &unsignedp));
5224 chain = targetm.calls.static_chain (current_function_decl, true);
5226 set_decl_incoming_rtl (parm, chain, false);
5227 set_parm_rtl (parm, local);
5228 mark_reg_pointer (local, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
5230 if (GET_MODE (local) != GET_MODE (chain))
5232 convert_move (local, chain, unsignedp);
5233 insn = get_last_insn ();
5235 else
5236 insn = emit_move_insn (local, chain);
5238 /* Mark the register as eliminable, similar to parameters. */
5239 if (MEM_P (chain)
5240 && reg_mentioned_p (arg_pointer_rtx, XEXP (chain, 0)))
5241 set_dst_reg_note (insn, REG_EQUIV, chain, local);
5243 /* If we aren't optimizing, save the static chain onto the stack. */
5244 if (!optimize)
5246 tree saved_static_chain_decl
5247 = build_decl (DECL_SOURCE_LOCATION (parm), VAR_DECL,
5248 DECL_NAME (parm), TREE_TYPE (parm));
5249 rtx saved_static_chain_rtx
5250 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
5251 SET_DECL_RTL (saved_static_chain_decl, saved_static_chain_rtx);
5252 emit_move_insn (saved_static_chain_rtx, chain);
5253 SET_DECL_VALUE_EXPR (parm, saved_static_chain_decl);
5254 DECL_HAS_VALUE_EXPR_P (parm) = 1;
5258 /* The following was moved from init_function_start.
5259 The move was supposed to make sdb output more accurate. */
5260 /* Indicate the beginning of the function body,
5261 as opposed to parm setup. */
5262 emit_note (NOTE_INSN_FUNCTION_BEG);
5264 gcc_assert (NOTE_P (get_last_insn ()));
5266 parm_birth_insn = get_last_insn ();
5268 /* If the function receives a non-local goto, then store the
5269 bits we need to restore the frame pointer. */
5270 if (cfun->nonlocal_goto_save_area)
5272 tree t_save;
5273 rtx r_save;
5275 tree var = TREE_OPERAND (cfun->nonlocal_goto_save_area, 0);
5276 gcc_assert (DECL_RTL_SET_P (var));
5278 t_save = build4 (ARRAY_REF,
5279 TREE_TYPE (TREE_TYPE (cfun->nonlocal_goto_save_area)),
5280 cfun->nonlocal_goto_save_area,
5281 integer_zero_node, NULL_TREE, NULL_TREE);
5282 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
5283 gcc_assert (GET_MODE (r_save) == Pmode);
5285 emit_move_insn (r_save, targetm.builtin_setjmp_frame_value ());
5286 update_nonlocal_goto_save_area ();
5289 if (crtl->profile)
5291 #ifdef PROFILE_HOOK
5292 PROFILE_HOOK (current_function_funcdef_no);
5293 #endif
5296 /* If we are doing generic stack checking, the probe should go here. */
5297 if (flag_stack_check == GENERIC_STACK_CHECK)
5298 stack_check_probe_note = emit_note (NOTE_INSN_DELETED);
5301 void
5302 pop_dummy_function (void)
5304 pop_cfun ();
5305 in_dummy_function = false;
5308 /* Undo the effects of init_dummy_function_start. */
5309 void
5310 expand_dummy_function_end (void)
5312 gcc_assert (in_dummy_function);
5314 /* End any sequences that failed to be closed due to syntax errors. */
5315 while (in_sequence_p ())
5316 end_sequence ();
5318 /* Outside function body, can't compute type's actual size
5319 until next function's body starts. */
5321 free_after_parsing (cfun);
5322 free_after_compilation (cfun);
5323 pop_dummy_function ();
5326 /* Helper for diddle_return_value. */
5328 void
5329 diddle_return_value_1 (void (*doit) (rtx, void *), void *arg, rtx outgoing)
5331 if (! outgoing)
5332 return;
5334 if (REG_P (outgoing))
5335 (*doit) (outgoing, arg);
5336 else if (GET_CODE (outgoing) == PARALLEL)
5338 int i;
5340 for (i = 0; i < XVECLEN (outgoing, 0); i++)
5342 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
5344 if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
5345 (*doit) (x, arg);
5350 /* Call DOIT for each hard register used as a return value from
5351 the current function. */
5353 void
5354 diddle_return_value (void (*doit) (rtx, void *), void *arg)
5356 diddle_return_value_1 (doit, arg, crtl->return_bnd);
5357 diddle_return_value_1 (doit, arg, crtl->return_rtx);
5360 static void
5361 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
5363 emit_clobber (reg);
5366 void
5367 clobber_return_register (void)
5369 diddle_return_value (do_clobber_return_reg, NULL);
5371 /* In case we do use pseudo to return value, clobber it too. */
5372 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
5374 tree decl_result = DECL_RESULT (current_function_decl);
5375 rtx decl_rtl = DECL_RTL (decl_result);
5376 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
5378 do_clobber_return_reg (decl_rtl, NULL);
5383 static void
5384 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
5386 emit_use (reg);
5389 static void
5390 use_return_register (void)
5392 diddle_return_value (do_use_return_reg, NULL);
5395 /* Set the location of the insn chain starting at INSN to LOC. */
5397 static void
5398 set_insn_locations (rtx_insn *insn, int loc)
5400 while (insn != NULL)
5402 if (INSN_P (insn))
5403 INSN_LOCATION (insn) = loc;
5404 insn = NEXT_INSN (insn);
5408 /* Generate RTL for the end of the current function. */
5410 void
5411 expand_function_end (void)
5413 /* If arg_pointer_save_area was referenced only from a nested
5414 function, we will not have initialized it yet. Do that now. */
5415 if (arg_pointer_save_area && ! crtl->arg_pointer_save_area_init)
5416 get_arg_pointer_save_area ();
5418 /* If we are doing generic stack checking and this function makes calls,
5419 do a stack probe at the start of the function to ensure we have enough
5420 space for another stack frame. */
5421 if (flag_stack_check == GENERIC_STACK_CHECK)
5423 rtx_insn *insn, *seq;
5425 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
5426 if (CALL_P (insn))
5428 rtx max_frame_size = GEN_INT (STACK_CHECK_MAX_FRAME_SIZE);
5429 start_sequence ();
5430 if (STACK_CHECK_MOVING_SP)
5431 anti_adjust_stack_and_probe (max_frame_size, true);
5432 else
5433 probe_stack_range (STACK_OLD_CHECK_PROTECT, max_frame_size);
5434 seq = get_insns ();
5435 end_sequence ();
5436 set_insn_locations (seq, prologue_location);
5437 emit_insn_before (seq, stack_check_probe_note);
5438 break;
5442 /* End any sequences that failed to be closed due to syntax errors. */
5443 while (in_sequence_p ())
5444 end_sequence ();
5446 clear_pending_stack_adjust ();
5447 do_pending_stack_adjust ();
5449 /* Output a linenumber for the end of the function.
5450 SDB depended on this. */
5451 set_curr_insn_location (input_location);
5453 /* Before the return label (if any), clobber the return
5454 registers so that they are not propagated live to the rest of
5455 the function. This can only happen with functions that drop
5456 through; if there had been a return statement, there would
5457 have either been a return rtx, or a jump to the return label.
5459 We delay actual code generation after the current_function_value_rtx
5460 is computed. */
5461 rtx_insn *clobber_after = get_last_insn ();
5463 /* Output the label for the actual return from the function. */
5464 emit_label (return_label);
5466 if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ)
5468 /* Let except.c know where it should emit the call to unregister
5469 the function context for sjlj exceptions. */
5470 if (flag_exceptions)
5471 sjlj_emit_function_exit_after (get_last_insn ());
5473 else
5475 /* We want to ensure that instructions that may trap are not
5476 moved into the epilogue by scheduling, because we don't
5477 always emit unwind information for the epilogue. */
5478 if (cfun->can_throw_non_call_exceptions)
5479 emit_insn (gen_blockage ());
5482 /* If this is an implementation of throw, do what's necessary to
5483 communicate between __builtin_eh_return and the epilogue. */
5484 expand_eh_return ();
5486 /* If scalar return value was computed in a pseudo-reg, or was a named
5487 return value that got dumped to the stack, copy that to the hard
5488 return register. */
5489 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
5491 tree decl_result = DECL_RESULT (current_function_decl);
5492 rtx decl_rtl = DECL_RTL (decl_result);
5494 if (REG_P (decl_rtl)
5495 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
5496 : DECL_REGISTER (decl_result))
5498 rtx real_decl_rtl = crtl->return_rtx;
5499 complex_mode cmode;
5501 /* This should be set in assign_parms. */
5502 gcc_assert (REG_FUNCTION_VALUE_P (real_decl_rtl));
5504 /* If this is a BLKmode structure being returned in registers,
5505 then use the mode computed in expand_return. Note that if
5506 decl_rtl is memory, then its mode may have been changed,
5507 but that crtl->return_rtx has not. */
5508 if (GET_MODE (real_decl_rtl) == BLKmode)
5509 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
5511 /* If a non-BLKmode return value should be padded at the least
5512 significant end of the register, shift it left by the appropriate
5513 amount. BLKmode results are handled using the group load/store
5514 machinery. */
5515 if (TYPE_MODE (TREE_TYPE (decl_result)) != BLKmode
5516 && REG_P (real_decl_rtl)
5517 && targetm.calls.return_in_msb (TREE_TYPE (decl_result)))
5519 emit_move_insn (gen_rtx_REG (GET_MODE (decl_rtl),
5520 REGNO (real_decl_rtl)),
5521 decl_rtl);
5522 shift_return_value (GET_MODE (decl_rtl), true, real_decl_rtl);
5524 else if (GET_CODE (real_decl_rtl) == PARALLEL)
5526 /* If expand_function_start has created a PARALLEL for decl_rtl,
5527 move the result to the real return registers. Otherwise, do
5528 a group load from decl_rtl for a named return. */
5529 if (GET_CODE (decl_rtl) == PARALLEL)
5530 emit_group_move (real_decl_rtl, decl_rtl);
5531 else
5532 emit_group_load (real_decl_rtl, decl_rtl,
5533 TREE_TYPE (decl_result),
5534 int_size_in_bytes (TREE_TYPE (decl_result)));
5536 /* In the case of complex integer modes smaller than a word, we'll
5537 need to generate some non-trivial bitfield insertions. Do that
5538 on a pseudo and not the hard register. */
5539 else if (GET_CODE (decl_rtl) == CONCAT
5540 && is_complex_int_mode (GET_MODE (decl_rtl), &cmode)
5541 && GET_MODE_BITSIZE (cmode) <= BITS_PER_WORD)
5543 int old_generating_concat_p;
5544 rtx tmp;
5546 old_generating_concat_p = generating_concat_p;
5547 generating_concat_p = 0;
5548 tmp = gen_reg_rtx (GET_MODE (decl_rtl));
5549 generating_concat_p = old_generating_concat_p;
5551 emit_move_insn (tmp, decl_rtl);
5552 emit_move_insn (real_decl_rtl, tmp);
5554 /* If a named return value dumped decl_return to memory, then
5555 we may need to re-do the PROMOTE_MODE signed/unsigned
5556 extension. */
5557 else if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
5559 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
5560 promote_function_mode (TREE_TYPE (decl_result),
5561 GET_MODE (decl_rtl), &unsignedp,
5562 TREE_TYPE (current_function_decl), 1);
5564 convert_move (real_decl_rtl, decl_rtl, unsignedp);
5566 else
5567 emit_move_insn (real_decl_rtl, decl_rtl);
5571 /* If returning a structure, arrange to return the address of the value
5572 in a place where debuggers expect to find it.
5574 If returning a structure PCC style,
5575 the caller also depends on this value.
5576 And cfun->returns_pcc_struct is not necessarily set. */
5577 if ((cfun->returns_struct || cfun->returns_pcc_struct)
5578 && !targetm.calls.omit_struct_return_reg)
5580 rtx value_address = DECL_RTL (DECL_RESULT (current_function_decl));
5581 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
5582 rtx outgoing;
5584 if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
5585 type = TREE_TYPE (type);
5586 else
5587 value_address = XEXP (value_address, 0);
5589 outgoing = targetm.calls.function_value (build_pointer_type (type),
5590 current_function_decl, true);
5592 /* Mark this as a function return value so integrate will delete the
5593 assignment and USE below when inlining this function. */
5594 REG_FUNCTION_VALUE_P (outgoing) = 1;
5596 /* The address may be ptr_mode and OUTGOING may be Pmode. */
5597 scalar_int_mode mode = as_a <scalar_int_mode> (GET_MODE (outgoing));
5598 value_address = convert_memory_address (mode, value_address);
5600 emit_move_insn (outgoing, value_address);
5602 /* Show return register used to hold result (in this case the address
5603 of the result. */
5604 crtl->return_rtx = outgoing;
5607 /* Emit the actual code to clobber return register. Don't emit
5608 it if clobber_after is a barrier, then the previous basic block
5609 certainly doesn't fall thru into the exit block. */
5610 if (!BARRIER_P (clobber_after))
5612 start_sequence ();
5613 clobber_return_register ();
5614 rtx_insn *seq = get_insns ();
5615 end_sequence ();
5617 emit_insn_after (seq, clobber_after);
5620 /* Output the label for the naked return from the function. */
5621 if (naked_return_label)
5622 emit_label (naked_return_label);
5624 /* @@@ This is a kludge. We want to ensure that instructions that
5625 may trap are not moved into the epilogue by scheduling, because
5626 we don't always emit unwind information for the epilogue. */
5627 if (cfun->can_throw_non_call_exceptions
5628 && targetm_common.except_unwind_info (&global_options) != UI_SJLJ)
5629 emit_insn (gen_blockage ());
5631 /* If stack protection is enabled for this function, check the guard. */
5632 if (crtl->stack_protect_guard && targetm.stack_protect_runtime_enabled_p ())
5633 stack_protect_epilogue ();
5635 /* If we had calls to alloca, and this machine needs
5636 an accurate stack pointer to exit the function,
5637 insert some code to save and restore the stack pointer. */
5638 if (! EXIT_IGNORE_STACK
5639 && cfun->calls_alloca)
5641 rtx tem = 0;
5643 start_sequence ();
5644 emit_stack_save (SAVE_FUNCTION, &tem);
5645 rtx_insn *seq = get_insns ();
5646 end_sequence ();
5647 emit_insn_before (seq, parm_birth_insn);
5649 emit_stack_restore (SAVE_FUNCTION, tem);
5652 /* ??? This should no longer be necessary since stupid is no longer with
5653 us, but there are some parts of the compiler (eg reload_combine, and
5654 sh mach_dep_reorg) that still try and compute their own lifetime info
5655 instead of using the general framework. */
5656 use_return_register ();
5660 get_arg_pointer_save_area (void)
5662 rtx ret = arg_pointer_save_area;
5664 if (! ret)
5666 ret = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
5667 arg_pointer_save_area = ret;
5670 if (! crtl->arg_pointer_save_area_init)
5672 /* Save the arg pointer at the beginning of the function. The
5673 generated stack slot may not be a valid memory address, so we
5674 have to check it and fix it if necessary. */
5675 start_sequence ();
5676 emit_move_insn (validize_mem (copy_rtx (ret)),
5677 crtl->args.internal_arg_pointer);
5678 rtx_insn *seq = get_insns ();
5679 end_sequence ();
5681 push_topmost_sequence ();
5682 emit_insn_after (seq, entry_of_function ());
5683 pop_topmost_sequence ();
5685 crtl->arg_pointer_save_area_init = true;
5688 return ret;
5692 /* If debugging dumps are requested, dump information about how the
5693 target handled -fstack-check=clash for the prologue.
5695 PROBES describes what if any probes were emitted.
5697 RESIDUALS indicates if the prologue had any residual allocation
5698 (i.e. total allocation was not a multiple of PROBE_INTERVAL). */
5700 void
5701 dump_stack_clash_frame_info (enum stack_clash_probes probes, bool residuals)
5703 if (!dump_file)
5704 return;
5706 switch (probes)
5708 case NO_PROBE_NO_FRAME:
5709 fprintf (dump_file,
5710 "Stack clash no probe no stack adjustment in prologue.\n");
5711 break;
5712 case NO_PROBE_SMALL_FRAME:
5713 fprintf (dump_file,
5714 "Stack clash no probe small stack adjustment in prologue.\n");
5715 break;
5716 case PROBE_INLINE:
5717 fprintf (dump_file, "Stack clash inline probes in prologue.\n");
5718 break;
5719 case PROBE_LOOP:
5720 fprintf (dump_file, "Stack clash probe loop in prologue.\n");
5721 break;
5724 if (residuals)
5725 fprintf (dump_file, "Stack clash residual allocation in prologue.\n");
5726 else
5727 fprintf (dump_file, "Stack clash no residual allocation in prologue.\n");
5729 if (frame_pointer_needed)
5730 fprintf (dump_file, "Stack clash frame pointer needed.\n");
5731 else
5732 fprintf (dump_file, "Stack clash no frame pointer needed.\n");
5734 if (TREE_THIS_VOLATILE (cfun->decl))
5735 fprintf (dump_file,
5736 "Stack clash noreturn prologue, assuming no implicit"
5737 " probes in caller.\n");
5738 else
5739 fprintf (dump_file,
5740 "Stack clash not noreturn prologue.\n");
5743 /* Add a list of INSNS to the hash HASHP, possibly allocating HASHP
5744 for the first time. */
5746 static void
5747 record_insns (rtx_insn *insns, rtx end, hash_table<insn_cache_hasher> **hashp)
5749 rtx_insn *tmp;
5750 hash_table<insn_cache_hasher> *hash = *hashp;
5752 if (hash == NULL)
5753 *hashp = hash = hash_table<insn_cache_hasher>::create_ggc (17);
5755 for (tmp = insns; tmp != end; tmp = NEXT_INSN (tmp))
5757 rtx *slot = hash->find_slot (tmp, INSERT);
5758 gcc_assert (*slot == NULL);
5759 *slot = tmp;
5763 /* INSN has been duplicated or replaced by as COPY, perhaps by duplicating a
5764 basic block, splitting or peepholes. If INSN is a prologue or epilogue
5765 insn, then record COPY as well. */
5767 void
5768 maybe_copy_prologue_epilogue_insn (rtx insn, rtx copy)
5770 hash_table<insn_cache_hasher> *hash;
5771 rtx *slot;
5773 hash = epilogue_insn_hash;
5774 if (!hash || !hash->find (insn))
5776 hash = prologue_insn_hash;
5777 if (!hash || !hash->find (insn))
5778 return;
5781 slot = hash->find_slot (copy, INSERT);
5782 gcc_assert (*slot == NULL);
5783 *slot = copy;
5786 /* Determine if any INSNs in HASH are, or are part of, INSN. Because
5787 we can be running after reorg, SEQUENCE rtl is possible. */
5789 static bool
5790 contains (const rtx_insn *insn, hash_table<insn_cache_hasher> *hash)
5792 if (hash == NULL)
5793 return false;
5795 if (NONJUMP_INSN_P (insn) && GET_CODE (PATTERN (insn)) == SEQUENCE)
5797 rtx_sequence *seq = as_a <rtx_sequence *> (PATTERN (insn));
5798 int i;
5799 for (i = seq->len () - 1; i >= 0; i--)
5800 if (hash->find (seq->element (i)))
5801 return true;
5802 return false;
5805 return hash->find (const_cast<rtx_insn *> (insn)) != NULL;
5809 prologue_contains (const rtx_insn *insn)
5811 return contains (insn, prologue_insn_hash);
5815 epilogue_contains (const rtx_insn *insn)
5817 return contains (insn, epilogue_insn_hash);
5821 prologue_epilogue_contains (const rtx_insn *insn)
5823 if (contains (insn, prologue_insn_hash))
5824 return 1;
5825 if (contains (insn, epilogue_insn_hash))
5826 return 1;
5827 return 0;
5830 void
5831 record_prologue_seq (rtx_insn *seq)
5833 record_insns (seq, NULL, &prologue_insn_hash);
5836 void
5837 record_epilogue_seq (rtx_insn *seq)
5839 record_insns (seq, NULL, &epilogue_insn_hash);
5842 /* Set JUMP_LABEL for a return insn. */
5844 void
5845 set_return_jump_label (rtx_insn *returnjump)
5847 rtx pat = PATTERN (returnjump);
5848 if (GET_CODE (pat) == PARALLEL)
5849 pat = XVECEXP (pat, 0, 0);
5850 if (ANY_RETURN_P (pat))
5851 JUMP_LABEL (returnjump) = pat;
5852 else
5853 JUMP_LABEL (returnjump) = ret_rtx;
5856 /* Return a sequence to be used as the split prologue for the current
5857 function, or NULL. */
5859 static rtx_insn *
5860 make_split_prologue_seq (void)
5862 if (!flag_split_stack
5863 || lookup_attribute ("no_split_stack", DECL_ATTRIBUTES (cfun->decl)))
5864 return NULL;
5866 start_sequence ();
5867 emit_insn (targetm.gen_split_stack_prologue ());
5868 rtx_insn *seq = get_insns ();
5869 end_sequence ();
5871 record_insns (seq, NULL, &prologue_insn_hash);
5872 set_insn_locations (seq, prologue_location);
5874 return seq;
5877 /* Return a sequence to be used as the prologue for the current function,
5878 or NULL. */
5880 static rtx_insn *
5881 make_prologue_seq (void)
5883 if (!targetm.have_prologue ())
5884 return NULL;
5886 start_sequence ();
5887 rtx_insn *seq = targetm.gen_prologue ();
5888 emit_insn (seq);
5890 /* Insert an explicit USE for the frame pointer
5891 if the profiling is on and the frame pointer is required. */
5892 if (crtl->profile && frame_pointer_needed)
5893 emit_use (hard_frame_pointer_rtx);
5895 /* Retain a map of the prologue insns. */
5896 record_insns (seq, NULL, &prologue_insn_hash);
5897 emit_note (NOTE_INSN_PROLOGUE_END);
5899 /* Ensure that instructions are not moved into the prologue when
5900 profiling is on. The call to the profiling routine can be
5901 emitted within the live range of a call-clobbered register. */
5902 if (!targetm.profile_before_prologue () && crtl->profile)
5903 emit_insn (gen_blockage ());
5905 seq = get_insns ();
5906 end_sequence ();
5907 set_insn_locations (seq, prologue_location);
5909 return seq;
5912 /* Return a sequence to be used as the epilogue for the current function,
5913 or NULL. */
5915 static rtx_insn *
5916 make_epilogue_seq (void)
5918 if (!targetm.have_epilogue ())
5919 return NULL;
5921 start_sequence ();
5922 emit_note (NOTE_INSN_EPILOGUE_BEG);
5923 rtx_insn *seq = targetm.gen_epilogue ();
5924 if (seq)
5925 emit_jump_insn (seq);
5927 /* Retain a map of the epilogue insns. */
5928 record_insns (seq, NULL, &epilogue_insn_hash);
5929 set_insn_locations (seq, epilogue_location);
5931 seq = get_insns ();
5932 rtx_insn *returnjump = get_last_insn ();
5933 end_sequence ();
5935 if (JUMP_P (returnjump))
5936 set_return_jump_label (returnjump);
5938 return seq;
5942 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
5943 this into place with notes indicating where the prologue ends and where
5944 the epilogue begins. Update the basic block information when possible.
5946 Notes on epilogue placement:
5947 There are several kinds of edges to the exit block:
5948 * a single fallthru edge from LAST_BB
5949 * possibly, edges from blocks containing sibcalls
5950 * possibly, fake edges from infinite loops
5952 The epilogue is always emitted on the fallthru edge from the last basic
5953 block in the function, LAST_BB, into the exit block.
5955 If LAST_BB is empty except for a label, it is the target of every
5956 other basic block in the function that ends in a return. If a
5957 target has a return or simple_return pattern (possibly with
5958 conditional variants), these basic blocks can be changed so that a
5959 return insn is emitted into them, and their target is adjusted to
5960 the real exit block.
5962 Notes on shrink wrapping: We implement a fairly conservative
5963 version of shrink-wrapping rather than the textbook one. We only
5964 generate a single prologue and a single epilogue. This is
5965 sufficient to catch a number of interesting cases involving early
5966 exits.
5968 First, we identify the blocks that require the prologue to occur before
5969 them. These are the ones that modify a call-saved register, or reference
5970 any of the stack or frame pointer registers. To simplify things, we then
5971 mark everything reachable from these blocks as also requiring a prologue.
5972 This takes care of loops automatically, and avoids the need to examine
5973 whether MEMs reference the frame, since it is sufficient to check for
5974 occurrences of the stack or frame pointer.
5976 We then compute the set of blocks for which the need for a prologue
5977 is anticipatable (borrowing terminology from the shrink-wrapping
5978 description in Muchnick's book). These are the blocks which either
5979 require a prologue themselves, or those that have only successors
5980 where the prologue is anticipatable. The prologue needs to be
5981 inserted on all edges from BB1->BB2 where BB2 is in ANTIC and BB1
5982 is not. For the moment, we ensure that only one such edge exists.
5984 The epilogue is placed as described above, but we make a
5985 distinction between inserting return and simple_return patterns
5986 when modifying other blocks that end in a return. Blocks that end
5987 in a sibcall omit the sibcall_epilogue if the block is not in
5988 ANTIC. */
5990 void
5991 thread_prologue_and_epilogue_insns (void)
5993 df_analyze ();
5995 /* Can't deal with multiple successors of the entry block at the
5996 moment. Function should always have at least one entry
5997 point. */
5998 gcc_assert (single_succ_p (ENTRY_BLOCK_PTR_FOR_FN (cfun)));
6000 edge entry_edge = single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun));
6001 edge orig_entry_edge = entry_edge;
6003 rtx_insn *split_prologue_seq = make_split_prologue_seq ();
6004 rtx_insn *prologue_seq = make_prologue_seq ();
6005 rtx_insn *epilogue_seq = make_epilogue_seq ();
6007 /* Try to perform a kind of shrink-wrapping, making sure the
6008 prologue/epilogue is emitted only around those parts of the
6009 function that require it. */
6010 try_shrink_wrapping (&entry_edge, prologue_seq);
6012 /* If the target can handle splitting the prologue/epilogue into separate
6013 components, try to shrink-wrap these components separately. */
6014 try_shrink_wrapping_separate (entry_edge->dest);
6016 /* If that did anything for any component we now need the generate the
6017 "main" prologue again. Because some targets require some of these
6018 to be called in a specific order (i386 requires the split prologue
6019 to be first, for example), we create all three sequences again here.
6020 If this does not work for some target, that target should not enable
6021 separate shrink-wrapping. */
6022 if (crtl->shrink_wrapped_separate)
6024 split_prologue_seq = make_split_prologue_seq ();
6025 prologue_seq = make_prologue_seq ();
6026 epilogue_seq = make_epilogue_seq ();
6029 rtl_profile_for_bb (EXIT_BLOCK_PTR_FOR_FN (cfun));
6031 /* A small fib -- epilogue is not yet completed, but we wish to re-use
6032 this marker for the splits of EH_RETURN patterns, and nothing else
6033 uses the flag in the meantime. */
6034 epilogue_completed = 1;
6036 /* Find non-fallthru edges that end with EH_RETURN instructions. On
6037 some targets, these get split to a special version of the epilogue
6038 code. In order to be able to properly annotate these with unwind
6039 info, try to split them now. If we get a valid split, drop an
6040 EPILOGUE_BEG note and mark the insns as epilogue insns. */
6041 edge e;
6042 edge_iterator ei;
6043 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
6045 rtx_insn *prev, *last, *trial;
6047 if (e->flags & EDGE_FALLTHRU)
6048 continue;
6049 last = BB_END (e->src);
6050 if (!eh_returnjump_p (last))
6051 continue;
6053 prev = PREV_INSN (last);
6054 trial = try_split (PATTERN (last), last, 1);
6055 if (trial == last)
6056 continue;
6058 record_insns (NEXT_INSN (prev), NEXT_INSN (trial), &epilogue_insn_hash);
6059 emit_note_after (NOTE_INSN_EPILOGUE_BEG, prev);
6062 edge exit_fallthru_edge = find_fallthru_edge (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds);
6064 if (exit_fallthru_edge)
6066 if (epilogue_seq)
6068 insert_insn_on_edge (epilogue_seq, exit_fallthru_edge);
6069 commit_edge_insertions ();
6071 /* The epilogue insns we inserted may cause the exit edge to no longer
6072 be fallthru. */
6073 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
6075 if (((e->flags & EDGE_FALLTHRU) != 0)
6076 && returnjump_p (BB_END (e->src)))
6077 e->flags &= ~EDGE_FALLTHRU;
6080 else if (next_active_insn (BB_END (exit_fallthru_edge->src)))
6082 /* We have a fall-through edge to the exit block, the source is not
6083 at the end of the function, and there will be an assembler epilogue
6084 at the end of the function.
6085 We can't use force_nonfallthru here, because that would try to
6086 use return. Inserting a jump 'by hand' is extremely messy, so
6087 we take advantage of cfg_layout_finalize using
6088 fixup_fallthru_exit_predecessor. */
6089 cfg_layout_initialize (0);
6090 basic_block cur_bb;
6091 FOR_EACH_BB_FN (cur_bb, cfun)
6092 if (cur_bb->index >= NUM_FIXED_BLOCKS
6093 && cur_bb->next_bb->index >= NUM_FIXED_BLOCKS)
6094 cur_bb->aux = cur_bb->next_bb;
6095 cfg_layout_finalize ();
6099 /* Insert the prologue. */
6101 rtl_profile_for_bb (ENTRY_BLOCK_PTR_FOR_FN (cfun));
6103 if (split_prologue_seq || prologue_seq)
6105 rtx_insn *split_prologue_insn = split_prologue_seq;
6106 if (split_prologue_seq)
6108 while (split_prologue_insn && !NONDEBUG_INSN_P (split_prologue_insn))
6109 split_prologue_insn = NEXT_INSN (split_prologue_insn);
6110 insert_insn_on_edge (split_prologue_seq, orig_entry_edge);
6113 rtx_insn *prologue_insn = prologue_seq;
6114 if (prologue_seq)
6116 while (prologue_insn && !NONDEBUG_INSN_P (prologue_insn))
6117 prologue_insn = NEXT_INSN (prologue_insn);
6118 insert_insn_on_edge (prologue_seq, entry_edge);
6121 commit_edge_insertions ();
6123 /* Look for basic blocks within the prologue insns. */
6124 if (split_prologue_insn
6125 && BLOCK_FOR_INSN (split_prologue_insn) == NULL)
6126 split_prologue_insn = NULL;
6127 if (prologue_insn
6128 && BLOCK_FOR_INSN (prologue_insn) == NULL)
6129 prologue_insn = NULL;
6130 if (split_prologue_insn || prologue_insn)
6132 auto_sbitmap blocks (last_basic_block_for_fn (cfun));
6133 bitmap_clear (blocks);
6134 if (split_prologue_insn)
6135 bitmap_set_bit (blocks,
6136 BLOCK_FOR_INSN (split_prologue_insn)->index);
6137 if (prologue_insn)
6138 bitmap_set_bit (blocks, BLOCK_FOR_INSN (prologue_insn)->index);
6139 find_many_sub_basic_blocks (blocks);
6143 default_rtl_profile ();
6145 /* Emit sibling epilogues before any sibling call sites. */
6146 for (ei = ei_start (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds);
6147 (e = ei_safe_edge (ei));
6148 ei_next (&ei))
6150 /* Skip those already handled, the ones that run without prologue. */
6151 if (e->flags & EDGE_IGNORE)
6153 e->flags &= ~EDGE_IGNORE;
6154 continue;
6157 rtx_insn *insn = BB_END (e->src);
6159 if (!(CALL_P (insn) && SIBLING_CALL_P (insn)))
6160 continue;
6162 if (rtx_insn *ep_seq = targetm.gen_sibcall_epilogue ())
6164 start_sequence ();
6165 emit_note (NOTE_INSN_EPILOGUE_BEG);
6166 emit_insn (ep_seq);
6167 rtx_insn *seq = get_insns ();
6168 end_sequence ();
6170 /* Retain a map of the epilogue insns. Used in life analysis to
6171 avoid getting rid of sibcall epilogue insns. Do this before we
6172 actually emit the sequence. */
6173 record_insns (seq, NULL, &epilogue_insn_hash);
6174 set_insn_locations (seq, epilogue_location);
6176 emit_insn_before (seq, insn);
6180 if (epilogue_seq)
6182 rtx_insn *insn, *next;
6184 /* Similarly, move any line notes that appear after the epilogue.
6185 There is no need, however, to be quite so anal about the existence
6186 of such a note. Also possibly move
6187 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
6188 info generation. */
6189 for (insn = epilogue_seq; insn; insn = next)
6191 next = NEXT_INSN (insn);
6192 if (NOTE_P (insn)
6193 && (NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG))
6194 reorder_insns (insn, insn, PREV_INSN (epilogue_seq));
6198 /* Threading the prologue and epilogue changes the artificial refs
6199 in the entry and exit blocks. */
6200 epilogue_completed = 1;
6201 df_update_entry_exit_and_calls ();
6204 /* Reposition the prologue-end and epilogue-begin notes after
6205 instruction scheduling. */
6207 void
6208 reposition_prologue_and_epilogue_notes (void)
6210 if (!targetm.have_prologue ()
6211 && !targetm.have_epilogue ()
6212 && !targetm.have_sibcall_epilogue ())
6213 return;
6215 /* Since the hash table is created on demand, the fact that it is
6216 non-null is a signal that it is non-empty. */
6217 if (prologue_insn_hash != NULL)
6219 size_t len = prologue_insn_hash->elements ();
6220 rtx_insn *insn, *last = NULL, *note = NULL;
6222 /* Scan from the beginning until we reach the last prologue insn. */
6223 /* ??? While we do have the CFG intact, there are two problems:
6224 (1) The prologue can contain loops (typically probing the stack),
6225 which means that the end of the prologue isn't in the first bb.
6226 (2) Sometimes the PROLOGUE_END note gets pushed into the next bb. */
6227 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
6229 if (NOTE_P (insn))
6231 if (NOTE_KIND (insn) == NOTE_INSN_PROLOGUE_END)
6232 note = insn;
6234 else if (contains (insn, prologue_insn_hash))
6236 last = insn;
6237 if (--len == 0)
6238 break;
6242 if (last)
6244 if (note == NULL)
6246 /* Scan forward looking for the PROLOGUE_END note. It should
6247 be right at the beginning of the block, possibly with other
6248 insn notes that got moved there. */
6249 for (note = NEXT_INSN (last); ; note = NEXT_INSN (note))
6251 if (NOTE_P (note)
6252 && NOTE_KIND (note) == NOTE_INSN_PROLOGUE_END)
6253 break;
6257 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
6258 if (LABEL_P (last))
6259 last = NEXT_INSN (last);
6260 reorder_insns (note, note, last);
6264 if (epilogue_insn_hash != NULL)
6266 edge_iterator ei;
6267 edge e;
6269 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
6271 rtx_insn *insn, *first = NULL, *note = NULL;
6272 basic_block bb = e->src;
6274 /* Scan from the beginning until we reach the first epilogue insn. */
6275 FOR_BB_INSNS (bb, insn)
6277 if (NOTE_P (insn))
6279 if (NOTE_KIND (insn) == NOTE_INSN_EPILOGUE_BEG)
6281 note = insn;
6282 if (first != NULL)
6283 break;
6286 else if (first == NULL && contains (insn, epilogue_insn_hash))
6288 first = insn;
6289 if (note != NULL)
6290 break;
6294 if (note)
6296 /* If the function has a single basic block, and no real
6297 epilogue insns (e.g. sibcall with no cleanup), the
6298 epilogue note can get scheduled before the prologue
6299 note. If we have frame related prologue insns, having
6300 them scanned during the epilogue will result in a crash.
6301 In this case re-order the epilogue note to just before
6302 the last insn in the block. */
6303 if (first == NULL)
6304 first = BB_END (bb);
6306 if (PREV_INSN (first) != note)
6307 reorder_insns (note, note, PREV_INSN (first));
6313 /* Returns the name of function declared by FNDECL. */
6314 const char *
6315 fndecl_name (tree fndecl)
6317 if (fndecl == NULL)
6318 return "(nofn)";
6319 return lang_hooks.decl_printable_name (fndecl, 1);
6322 /* Returns the name of function FN. */
6323 const char *
6324 function_name (struct function *fn)
6326 tree fndecl = (fn == NULL) ? NULL : fn->decl;
6327 return fndecl_name (fndecl);
6330 /* Returns the name of the current function. */
6331 const char *
6332 current_function_name (void)
6334 return function_name (cfun);
6338 static unsigned int
6339 rest_of_handle_check_leaf_regs (void)
6341 #ifdef LEAF_REGISTERS
6342 crtl->uses_only_leaf_regs
6343 = optimize > 0 && only_leaf_regs_used () && leaf_function_p ();
6344 #endif
6345 return 0;
6348 /* Insert a TYPE into the used types hash table of CFUN. */
6350 static void
6351 used_types_insert_helper (tree type, struct function *func)
6353 if (type != NULL && func != NULL)
6355 if (func->used_types_hash == NULL)
6356 func->used_types_hash = hash_set<tree>::create_ggc (37);
6358 func->used_types_hash->add (type);
6362 /* Given a type, insert it into the used hash table in cfun. */
6363 void
6364 used_types_insert (tree t)
6366 while (POINTER_TYPE_P (t) || TREE_CODE (t) == ARRAY_TYPE)
6367 if (TYPE_NAME (t))
6368 break;
6369 else
6370 t = TREE_TYPE (t);
6371 if (TREE_CODE (t) == ERROR_MARK)
6372 return;
6373 if (TYPE_NAME (t) == NULL_TREE
6374 || TYPE_NAME (t) == TYPE_NAME (TYPE_MAIN_VARIANT (t)))
6375 t = TYPE_MAIN_VARIANT (t);
6376 if (debug_info_level > DINFO_LEVEL_NONE)
6378 if (cfun)
6379 used_types_insert_helper (t, cfun);
6380 else
6382 /* So this might be a type referenced by a global variable.
6383 Record that type so that we can later decide to emit its
6384 debug information. */
6385 vec_safe_push (types_used_by_cur_var_decl, t);
6390 /* Helper to Hash a struct types_used_by_vars_entry. */
6392 static hashval_t
6393 hash_types_used_by_vars_entry (const struct types_used_by_vars_entry *entry)
6395 gcc_assert (entry && entry->var_decl && entry->type);
6397 return iterative_hash_object (entry->type,
6398 iterative_hash_object (entry->var_decl, 0));
6401 /* Hash function of the types_used_by_vars_entry hash table. */
6403 hashval_t
6404 used_type_hasher::hash (types_used_by_vars_entry *entry)
6406 return hash_types_used_by_vars_entry (entry);
6409 /*Equality function of the types_used_by_vars_entry hash table. */
6411 bool
6412 used_type_hasher::equal (types_used_by_vars_entry *e1,
6413 types_used_by_vars_entry *e2)
6415 return (e1->var_decl == e2->var_decl && e1->type == e2->type);
6418 /* Inserts an entry into the types_used_by_vars_hash hash table. */
6420 void
6421 types_used_by_var_decl_insert (tree type, tree var_decl)
6423 if (type != NULL && var_decl != NULL)
6425 types_used_by_vars_entry **slot;
6426 struct types_used_by_vars_entry e;
6427 e.var_decl = var_decl;
6428 e.type = type;
6429 if (types_used_by_vars_hash == NULL)
6430 types_used_by_vars_hash
6431 = hash_table<used_type_hasher>::create_ggc (37);
6433 slot = types_used_by_vars_hash->find_slot (&e, INSERT);
6434 if (*slot == NULL)
6436 struct types_used_by_vars_entry *entry;
6437 entry = ggc_alloc<types_used_by_vars_entry> ();
6438 entry->type = type;
6439 entry->var_decl = var_decl;
6440 *slot = entry;
6445 namespace {
6447 const pass_data pass_data_leaf_regs =
6449 RTL_PASS, /* type */
6450 "*leaf_regs", /* name */
6451 OPTGROUP_NONE, /* optinfo_flags */
6452 TV_NONE, /* tv_id */
6453 0, /* properties_required */
6454 0, /* properties_provided */
6455 0, /* properties_destroyed */
6456 0, /* todo_flags_start */
6457 0, /* todo_flags_finish */
6460 class pass_leaf_regs : public rtl_opt_pass
6462 public:
6463 pass_leaf_regs (gcc::context *ctxt)
6464 : rtl_opt_pass (pass_data_leaf_regs, ctxt)
6467 /* opt_pass methods: */
6468 virtual unsigned int execute (function *)
6470 return rest_of_handle_check_leaf_regs ();
6473 }; // class pass_leaf_regs
6475 } // anon namespace
6477 rtl_opt_pass *
6478 make_pass_leaf_regs (gcc::context *ctxt)
6480 return new pass_leaf_regs (ctxt);
6483 static unsigned int
6484 rest_of_handle_thread_prologue_and_epilogue (void)
6486 /* prepare_shrink_wrap is sensitive to the block structure of the control
6487 flow graph, so clean it up first. */
6488 if (optimize)
6489 cleanup_cfg (0);
6491 /* On some machines, the prologue and epilogue code, or parts thereof,
6492 can be represented as RTL. Doing so lets us schedule insns between
6493 it and the rest of the code and also allows delayed branch
6494 scheduling to operate in the epilogue. */
6495 thread_prologue_and_epilogue_insns ();
6497 /* Some non-cold blocks may now be only reachable from cold blocks.
6498 Fix that up. */
6499 fixup_partitions ();
6501 /* Shrink-wrapping can result in unreachable edges in the epilogue,
6502 see PR57320. */
6503 cleanup_cfg (optimize ? CLEANUP_EXPENSIVE : 0);
6505 /* The stack usage info is finalized during prologue expansion. */
6506 if (flag_stack_usage_info)
6507 output_stack_usage ();
6509 return 0;
6512 namespace {
6514 const pass_data pass_data_thread_prologue_and_epilogue =
6516 RTL_PASS, /* type */
6517 "pro_and_epilogue", /* name */
6518 OPTGROUP_NONE, /* optinfo_flags */
6519 TV_THREAD_PROLOGUE_AND_EPILOGUE, /* tv_id */
6520 0, /* properties_required */
6521 0, /* properties_provided */
6522 0, /* properties_destroyed */
6523 0, /* todo_flags_start */
6524 ( TODO_df_verify | TODO_df_finish ), /* todo_flags_finish */
6527 class pass_thread_prologue_and_epilogue : public rtl_opt_pass
6529 public:
6530 pass_thread_prologue_and_epilogue (gcc::context *ctxt)
6531 : rtl_opt_pass (pass_data_thread_prologue_and_epilogue, ctxt)
6534 /* opt_pass methods: */
6535 virtual unsigned int execute (function *)
6537 return rest_of_handle_thread_prologue_and_epilogue ();
6540 }; // class pass_thread_prologue_and_epilogue
6542 } // anon namespace
6544 rtl_opt_pass *
6545 make_pass_thread_prologue_and_epilogue (gcc::context *ctxt)
6547 return new pass_thread_prologue_and_epilogue (ctxt);
6551 /* This mini-pass fixes fall-out from SSA in asm statements that have
6552 in-out constraints. Say you start with
6554 orig = inout;
6555 asm ("": "+mr" (inout));
6556 use (orig);
6558 which is transformed very early to use explicit output and match operands:
6560 orig = inout;
6561 asm ("": "=mr" (inout) : "0" (inout));
6562 use (orig);
6564 Or, after SSA and copyprop,
6566 asm ("": "=mr" (inout_2) : "0" (inout_1));
6567 use (inout_1);
6569 Clearly inout_2 and inout_1 can't be coalesced easily anymore, as
6570 they represent two separate values, so they will get different pseudo
6571 registers during expansion. Then, since the two operands need to match
6572 per the constraints, but use different pseudo registers, reload can
6573 only register a reload for these operands. But reloads can only be
6574 satisfied by hardregs, not by memory, so we need a register for this
6575 reload, just because we are presented with non-matching operands.
6576 So, even though we allow memory for this operand, no memory can be
6577 used for it, just because the two operands don't match. This can
6578 cause reload failures on register-starved targets.
6580 So it's a symptom of reload not being able to use memory for reloads
6581 or, alternatively it's also a symptom of both operands not coming into
6582 reload as matching (in which case the pseudo could go to memory just
6583 fine, as the alternative allows it, and no reload would be necessary).
6584 We fix the latter problem here, by transforming
6586 asm ("": "=mr" (inout_2) : "0" (inout_1));
6588 back to
6590 inout_2 = inout_1;
6591 asm ("": "=mr" (inout_2) : "0" (inout_2)); */
6593 static void
6594 match_asm_constraints_1 (rtx_insn *insn, rtx *p_sets, int noutputs)
6596 int i;
6597 bool changed = false;
6598 rtx op = SET_SRC (p_sets[0]);
6599 int ninputs = ASM_OPERANDS_INPUT_LENGTH (op);
6600 rtvec inputs = ASM_OPERANDS_INPUT_VEC (op);
6601 bool *output_matched = XALLOCAVEC (bool, noutputs);
6603 memset (output_matched, 0, noutputs * sizeof (bool));
6604 for (i = 0; i < ninputs; i++)
6606 rtx input, output;
6607 rtx_insn *insns;
6608 const char *constraint = ASM_OPERANDS_INPUT_CONSTRAINT (op, i);
6609 char *end;
6610 int match, j;
6612 if (*constraint == '%')
6613 constraint++;
6615 match = strtoul (constraint, &end, 10);
6616 if (end == constraint)
6617 continue;
6619 gcc_assert (match < noutputs);
6620 output = SET_DEST (p_sets[match]);
6621 input = RTVEC_ELT (inputs, i);
6622 /* Only do the transformation for pseudos. */
6623 if (! REG_P (output)
6624 || rtx_equal_p (output, input)
6625 || (GET_MODE (input) != VOIDmode
6626 && GET_MODE (input) != GET_MODE (output)))
6627 continue;
6629 /* We can't do anything if the output is also used as input,
6630 as we're going to overwrite it. */
6631 for (j = 0; j < ninputs; j++)
6632 if (reg_overlap_mentioned_p (output, RTVEC_ELT (inputs, j)))
6633 break;
6634 if (j != ninputs)
6635 continue;
6637 /* Avoid changing the same input several times. For
6638 asm ("" : "=mr" (out1), "=mr" (out2) : "0" (in), "1" (in));
6639 only change in once (to out1), rather than changing it
6640 first to out1 and afterwards to out2. */
6641 if (i > 0)
6643 for (j = 0; j < noutputs; j++)
6644 if (output_matched[j] && input == SET_DEST (p_sets[j]))
6645 break;
6646 if (j != noutputs)
6647 continue;
6649 output_matched[match] = true;
6651 start_sequence ();
6652 emit_move_insn (output, input);
6653 insns = get_insns ();
6654 end_sequence ();
6655 emit_insn_before (insns, insn);
6657 /* Now replace all mentions of the input with output. We can't
6658 just replace the occurrence in inputs[i], as the register might
6659 also be used in some other input (or even in an address of an
6660 output), which would mean possibly increasing the number of
6661 inputs by one (namely 'output' in addition), which might pose
6662 a too complicated problem for reload to solve. E.g. this situation:
6664 asm ("" : "=r" (output), "=m" (input) : "0" (input))
6666 Here 'input' is used in two occurrences as input (once for the
6667 input operand, once for the address in the second output operand).
6668 If we would replace only the occurrence of the input operand (to
6669 make the matching) we would be left with this:
6671 output = input
6672 asm ("" : "=r" (output), "=m" (input) : "0" (output))
6674 Now we suddenly have two different input values (containing the same
6675 value, but different pseudos) where we formerly had only one.
6676 With more complicated asms this might lead to reload failures
6677 which wouldn't have happen without this pass. So, iterate over
6678 all operands and replace all occurrences of the register used. */
6679 for (j = 0; j < noutputs; j++)
6680 if (!rtx_equal_p (SET_DEST (p_sets[j]), input)
6681 && reg_overlap_mentioned_p (input, SET_DEST (p_sets[j])))
6682 SET_DEST (p_sets[j]) = replace_rtx (SET_DEST (p_sets[j]),
6683 input, output);
6684 for (j = 0; j < ninputs; j++)
6685 if (reg_overlap_mentioned_p (input, RTVEC_ELT (inputs, j)))
6686 RTVEC_ELT (inputs, j) = replace_rtx (RTVEC_ELT (inputs, j),
6687 input, output);
6689 changed = true;
6692 if (changed)
6693 df_insn_rescan (insn);
6696 /* Add the decl D to the local_decls list of FUN. */
6698 void
6699 add_local_decl (struct function *fun, tree d)
6701 gcc_assert (VAR_P (d));
6702 vec_safe_push (fun->local_decls, d);
6705 namespace {
6707 const pass_data pass_data_match_asm_constraints =
6709 RTL_PASS, /* type */
6710 "asmcons", /* name */
6711 OPTGROUP_NONE, /* optinfo_flags */
6712 TV_NONE, /* tv_id */
6713 0, /* properties_required */
6714 0, /* properties_provided */
6715 0, /* properties_destroyed */
6716 0, /* todo_flags_start */
6717 0, /* todo_flags_finish */
6720 class pass_match_asm_constraints : public rtl_opt_pass
6722 public:
6723 pass_match_asm_constraints (gcc::context *ctxt)
6724 : rtl_opt_pass (pass_data_match_asm_constraints, ctxt)
6727 /* opt_pass methods: */
6728 virtual unsigned int execute (function *);
6730 }; // class pass_match_asm_constraints
6732 unsigned
6733 pass_match_asm_constraints::execute (function *fun)
6735 basic_block bb;
6736 rtx_insn *insn;
6737 rtx pat, *p_sets;
6738 int noutputs;
6740 if (!crtl->has_asm_statement)
6741 return 0;
6743 df_set_flags (DF_DEFER_INSN_RESCAN);
6744 FOR_EACH_BB_FN (bb, fun)
6746 FOR_BB_INSNS (bb, insn)
6748 if (!INSN_P (insn))
6749 continue;
6751 pat = PATTERN (insn);
6752 if (GET_CODE (pat) == PARALLEL)
6753 p_sets = &XVECEXP (pat, 0, 0), noutputs = XVECLEN (pat, 0);
6754 else if (GET_CODE (pat) == SET)
6755 p_sets = &PATTERN (insn), noutputs = 1;
6756 else
6757 continue;
6759 if (GET_CODE (*p_sets) == SET
6760 && GET_CODE (SET_SRC (*p_sets)) == ASM_OPERANDS)
6761 match_asm_constraints_1 (insn, p_sets, noutputs);
6765 return TODO_df_finish;
6768 } // anon namespace
6770 rtl_opt_pass *
6771 make_pass_match_asm_constraints (gcc::context *ctxt)
6773 return new pass_match_asm_constraints (ctxt);
6777 #include "gt-function.h"