Small ChangeLog tweak.
[official-gcc.git] / gcc / function.c
blobf625489205be3f31c17b39e102dd94d6a29cda59
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"
81 /* So we can assign to cfun in this file. */
82 #undef cfun
84 #ifndef STACK_ALIGNMENT_NEEDED
85 #define STACK_ALIGNMENT_NEEDED 1
86 #endif
88 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
90 /* Round a value to the lowest integer less than it that is a multiple of
91 the required alignment. Avoid using division in case the value is
92 negative. Assume the alignment is a power of two. */
93 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
95 /* Similar, but round to the next highest integer that meets the
96 alignment. */
97 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
99 /* Nonzero once virtual register instantiation has been done.
100 assign_stack_local uses frame_pointer_rtx when this is nonzero.
101 calls.c:emit_library_call_value_1 uses it to set up
102 post-instantiation libcalls. */
103 int virtuals_instantiated;
105 /* Assign unique numbers to labels generated for profiling, debugging, etc. */
106 static GTY(()) int funcdef_no;
108 /* These variables hold pointers to functions to create and destroy
109 target specific, per-function data structures. */
110 struct machine_function * (*init_machine_status) (void);
112 /* The currently compiled function. */
113 struct function *cfun = 0;
115 /* These hashes record the prologue and epilogue insns. */
117 struct insn_cache_hasher : ggc_cache_ptr_hash<rtx_def>
119 static hashval_t hash (rtx x) { return htab_hash_pointer (x); }
120 static bool equal (rtx a, rtx b) { return a == b; }
123 static GTY((cache))
124 hash_table<insn_cache_hasher> *prologue_insn_hash;
125 static GTY((cache))
126 hash_table<insn_cache_hasher> *epilogue_insn_hash;
129 hash_table<used_type_hasher> *types_used_by_vars_hash = NULL;
130 vec<tree, va_gc> *types_used_by_cur_var_decl;
132 /* Forward declarations. */
134 static struct temp_slot *find_temp_slot_from_address (rtx);
135 static void pad_to_arg_alignment (struct args_size *, int, struct args_size *);
136 static void pad_below (struct args_size *, machine_mode, tree);
137 static void reorder_blocks_1 (rtx_insn *, tree, vec<tree> *);
138 static int all_blocks (tree, tree *);
139 static tree *get_block_vector (tree, int *);
140 extern tree debug_find_var_in_block_tree (tree, tree);
141 /* We always define `record_insns' even if it's not used so that we
142 can always export `prologue_epilogue_contains'. */
143 static void record_insns (rtx_insn *, rtx, hash_table<insn_cache_hasher> **)
144 ATTRIBUTE_UNUSED;
145 static bool contains (const rtx_insn *, hash_table<insn_cache_hasher> *);
146 static void prepare_function_start (void);
147 static void do_clobber_return_reg (rtx, void *);
148 static void do_use_return_reg (rtx, void *);
151 /* Stack of nested functions. */
152 /* Keep track of the cfun stack. */
154 static vec<function *> function_context_stack;
156 /* Save the current context for compilation of a nested function.
157 This is called from language-specific code. */
159 void
160 push_function_context (void)
162 if (cfun == 0)
163 allocate_struct_function (NULL, false);
165 function_context_stack.safe_push (cfun);
166 set_cfun (NULL);
169 /* Restore the last saved context, at the end of a nested function.
170 This function is called from language-specific code. */
172 void
173 pop_function_context (void)
175 struct function *p = function_context_stack.pop ();
176 set_cfun (p);
177 current_function_decl = p->decl;
179 /* Reset variables that have known state during rtx generation. */
180 virtuals_instantiated = 0;
181 generating_concat_p = 1;
184 /* Clear out all parts of the state in F that can safely be discarded
185 after the function has been parsed, but not compiled, to let
186 garbage collection reclaim the memory. */
188 void
189 free_after_parsing (struct function *f)
191 f->language = 0;
194 /* Clear out all parts of the state in F that can safely be discarded
195 after the function has been compiled, to let garbage collection
196 reclaim the memory. */
198 void
199 free_after_compilation (struct function *f)
201 prologue_insn_hash = NULL;
202 epilogue_insn_hash = NULL;
204 free (crtl->emit.regno_pointer_align);
206 memset (crtl, 0, sizeof (struct rtl_data));
207 f->eh = NULL;
208 f->machine = NULL;
209 f->cfg = NULL;
210 f->curr_properties &= ~PROP_cfg;
212 regno_reg_rtx = NULL;
215 /* Return size needed for stack frame based on slots so far allocated.
216 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
217 the caller may have to do that. */
219 HOST_WIDE_INT
220 get_frame_size (void)
222 if (FRAME_GROWS_DOWNWARD)
223 return -frame_offset;
224 else
225 return frame_offset;
228 /* Issue an error message and return TRUE if frame OFFSET overflows in
229 the signed target pointer arithmetics for function FUNC. Otherwise
230 return FALSE. */
232 bool
233 frame_offset_overflow (HOST_WIDE_INT offset, tree func)
235 unsigned HOST_WIDE_INT size = FRAME_GROWS_DOWNWARD ? -offset : offset;
237 if (size > (HOST_WIDE_INT_1U << (GET_MODE_BITSIZE (Pmode) - 1))
238 /* Leave room for the fixed part of the frame. */
239 - 64 * UNITS_PER_WORD)
241 error_at (DECL_SOURCE_LOCATION (func),
242 "total size of local objects too large");
243 return TRUE;
246 return FALSE;
249 /* Return the minimum spill slot alignment for a register of mode MODE. */
251 unsigned int
252 spill_slot_alignment (machine_mode mode ATTRIBUTE_UNUSED)
254 return STACK_SLOT_ALIGNMENT (NULL_TREE, mode, GET_MODE_ALIGNMENT (mode));
257 /* Return stack slot alignment in bits for TYPE and MODE. */
259 static unsigned int
260 get_stack_local_alignment (tree type, machine_mode mode)
262 unsigned int alignment;
264 if (mode == BLKmode)
265 alignment = BIGGEST_ALIGNMENT;
266 else
267 alignment = GET_MODE_ALIGNMENT (mode);
269 /* Allow the frond-end to (possibly) increase the alignment of this
270 stack slot. */
271 if (! type)
272 type = lang_hooks.types.type_for_mode (mode, 0);
274 return STACK_SLOT_ALIGNMENT (type, mode, alignment);
277 /* Determine whether it is possible to fit a stack slot of size SIZE and
278 alignment ALIGNMENT into an area in the stack frame that starts at
279 frame offset START and has a length of LENGTH. If so, store the frame
280 offset to be used for the stack slot in *POFFSET and return true;
281 return false otherwise. This function will extend the frame size when
282 given a start/length pair that lies at the end of the frame. */
284 static bool
285 try_fit_stack_local (HOST_WIDE_INT start, HOST_WIDE_INT length,
286 HOST_WIDE_INT size, unsigned int alignment,
287 HOST_WIDE_INT *poffset)
289 HOST_WIDE_INT this_frame_offset;
290 int frame_off, frame_alignment, frame_phase;
292 /* Calculate how many bytes the start of local variables is off from
293 stack alignment. */
294 frame_alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
295 frame_off = STARTING_FRAME_OFFSET % frame_alignment;
296 frame_phase = frame_off ? frame_alignment - frame_off : 0;
298 /* Round the frame offset to the specified alignment. */
300 /* We must be careful here, since FRAME_OFFSET might be negative and
301 division with a negative dividend isn't as well defined as we might
302 like. So we instead assume that ALIGNMENT is a power of two and
303 use logical operations which are unambiguous. */
304 if (FRAME_GROWS_DOWNWARD)
305 this_frame_offset
306 = (FLOOR_ROUND (start + length - size - frame_phase,
307 (unsigned HOST_WIDE_INT) alignment)
308 + frame_phase);
309 else
310 this_frame_offset
311 = (CEIL_ROUND (start - frame_phase,
312 (unsigned HOST_WIDE_INT) alignment)
313 + frame_phase);
315 /* See if it fits. If this space is at the edge of the frame,
316 consider extending the frame to make it fit. Our caller relies on
317 this when allocating a new slot. */
318 if (frame_offset == start && this_frame_offset < frame_offset)
319 frame_offset = this_frame_offset;
320 else if (this_frame_offset < start)
321 return false;
322 else if (start + length == frame_offset
323 && this_frame_offset + size > start + length)
324 frame_offset = this_frame_offset + size;
325 else if (this_frame_offset + size > start + length)
326 return false;
328 *poffset = this_frame_offset;
329 return true;
332 /* Create a new frame_space structure describing free space in the stack
333 frame beginning at START and ending at END, and chain it into the
334 function's frame_space_list. */
336 static void
337 add_frame_space (HOST_WIDE_INT start, HOST_WIDE_INT end)
339 struct frame_space *space = ggc_alloc<frame_space> ();
340 space->next = crtl->frame_space_list;
341 crtl->frame_space_list = space;
342 space->start = start;
343 space->length = end - start;
346 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
347 with machine mode MODE.
349 ALIGN controls the amount of alignment for the address of the slot:
350 0 means according to MODE,
351 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
352 -2 means use BITS_PER_UNIT,
353 positive specifies alignment boundary in bits.
355 KIND has ASLK_REDUCE_ALIGN bit set if it is OK to reduce
356 alignment and ASLK_RECORD_PAD bit set if we should remember
357 extra space we allocated for alignment purposes. When we are
358 called from assign_stack_temp_for_type, it is not set so we don't
359 track the same stack slot in two independent lists.
361 We do not round to stack_boundary here. */
364 assign_stack_local_1 (machine_mode mode, HOST_WIDE_INT size,
365 int align, int kind)
367 rtx x, addr;
368 int bigend_correction = 0;
369 HOST_WIDE_INT slot_offset = 0, old_frame_offset;
370 unsigned int alignment, alignment_in_bits;
372 if (align == 0)
374 alignment = get_stack_local_alignment (NULL, mode);
375 alignment /= BITS_PER_UNIT;
377 else if (align == -1)
379 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
380 size = CEIL_ROUND (size, alignment);
382 else if (align == -2)
383 alignment = 1; /* BITS_PER_UNIT / BITS_PER_UNIT */
384 else
385 alignment = align / BITS_PER_UNIT;
387 alignment_in_bits = alignment * BITS_PER_UNIT;
389 /* Ignore alignment if it exceeds MAX_SUPPORTED_STACK_ALIGNMENT. */
390 if (alignment_in_bits > MAX_SUPPORTED_STACK_ALIGNMENT)
392 alignment_in_bits = MAX_SUPPORTED_STACK_ALIGNMENT;
393 alignment = alignment_in_bits / BITS_PER_UNIT;
396 if (SUPPORTS_STACK_ALIGNMENT)
398 if (crtl->stack_alignment_estimated < alignment_in_bits)
400 if (!crtl->stack_realign_processed)
401 crtl->stack_alignment_estimated = alignment_in_bits;
402 else
404 /* If stack is realigned and stack alignment value
405 hasn't been finalized, it is OK not to increase
406 stack_alignment_estimated. The bigger alignment
407 requirement is recorded in stack_alignment_needed
408 below. */
409 gcc_assert (!crtl->stack_realign_finalized);
410 if (!crtl->stack_realign_needed)
412 /* It is OK to reduce the alignment as long as the
413 requested size is 0 or the estimated stack
414 alignment >= mode alignment. */
415 gcc_assert ((kind & ASLK_REDUCE_ALIGN)
416 || size == 0
417 || (crtl->stack_alignment_estimated
418 >= GET_MODE_ALIGNMENT (mode)));
419 alignment_in_bits = crtl->stack_alignment_estimated;
420 alignment = alignment_in_bits / BITS_PER_UNIT;
426 if (crtl->stack_alignment_needed < alignment_in_bits)
427 crtl->stack_alignment_needed = alignment_in_bits;
428 if (crtl->max_used_stack_slot_alignment < alignment_in_bits)
429 crtl->max_used_stack_slot_alignment = alignment_in_bits;
431 if (mode != BLKmode || size != 0)
433 if (kind & ASLK_RECORD_PAD)
435 struct frame_space **psp;
437 for (psp = &crtl->frame_space_list; *psp; psp = &(*psp)->next)
439 struct frame_space *space = *psp;
440 if (!try_fit_stack_local (space->start, space->length, size,
441 alignment, &slot_offset))
442 continue;
443 *psp = space->next;
444 if (slot_offset > space->start)
445 add_frame_space (space->start, slot_offset);
446 if (slot_offset + size < space->start + space->length)
447 add_frame_space (slot_offset + size,
448 space->start + space->length);
449 goto found_space;
453 else if (!STACK_ALIGNMENT_NEEDED)
455 slot_offset = frame_offset;
456 goto found_space;
459 old_frame_offset = frame_offset;
461 if (FRAME_GROWS_DOWNWARD)
463 frame_offset -= size;
464 try_fit_stack_local (frame_offset, size, size, alignment, &slot_offset);
466 if (kind & ASLK_RECORD_PAD)
468 if (slot_offset > frame_offset)
469 add_frame_space (frame_offset, slot_offset);
470 if (slot_offset + size < old_frame_offset)
471 add_frame_space (slot_offset + size, old_frame_offset);
474 else
476 frame_offset += size;
477 try_fit_stack_local (old_frame_offset, size, size, alignment, &slot_offset);
479 if (kind & ASLK_RECORD_PAD)
481 if (slot_offset > old_frame_offset)
482 add_frame_space (old_frame_offset, slot_offset);
483 if (slot_offset + size < frame_offset)
484 add_frame_space (slot_offset + size, frame_offset);
488 found_space:
489 /* On a big-endian machine, if we are allocating more space than we will use,
490 use the least significant bytes of those that are allocated. */
491 if (BYTES_BIG_ENDIAN && mode != BLKmode && GET_MODE_SIZE (mode) < size)
492 bigend_correction = size - GET_MODE_SIZE (mode);
494 /* If we have already instantiated virtual registers, return the actual
495 address relative to the frame pointer. */
496 if (virtuals_instantiated)
497 addr = plus_constant (Pmode, frame_pointer_rtx,
498 trunc_int_for_mode
499 (slot_offset + bigend_correction
500 + STARTING_FRAME_OFFSET, Pmode));
501 else
502 addr = plus_constant (Pmode, virtual_stack_vars_rtx,
503 trunc_int_for_mode
504 (slot_offset + bigend_correction,
505 Pmode));
507 x = gen_rtx_MEM (mode, addr);
508 set_mem_align (x, alignment_in_bits);
509 MEM_NOTRAP_P (x) = 1;
511 vec_safe_push (stack_slot_list, x);
513 if (frame_offset_overflow (frame_offset, current_function_decl))
514 frame_offset = 0;
516 return x;
519 /* Wrap up assign_stack_local_1 with last parameter as false. */
522 assign_stack_local (machine_mode mode, HOST_WIDE_INT size, int align)
524 return assign_stack_local_1 (mode, size, align, ASLK_RECORD_PAD);
527 /* In order to evaluate some expressions, such as function calls returning
528 structures in memory, we need to temporarily allocate stack locations.
529 We record each allocated temporary in the following structure.
531 Associated with each temporary slot is a nesting level. When we pop up
532 one level, all temporaries associated with the previous level are freed.
533 Normally, all temporaries are freed after the execution of the statement
534 in which they were created. However, if we are inside a ({...}) grouping,
535 the result may be in a temporary and hence must be preserved. If the
536 result could be in a temporary, we preserve it if we can determine which
537 one it is in. If we cannot determine which temporary may contain the
538 result, all temporaries are preserved. A temporary is preserved by
539 pretending it was allocated at the previous nesting level. */
541 struct GTY(()) temp_slot {
542 /* Points to next temporary slot. */
543 struct temp_slot *next;
544 /* Points to previous temporary slot. */
545 struct temp_slot *prev;
546 /* The rtx to used to reference the slot. */
547 rtx slot;
548 /* The size, in units, of the slot. */
549 HOST_WIDE_INT size;
550 /* The type of the object in the slot, or zero if it doesn't correspond
551 to a type. We use this to determine whether a slot can be reused.
552 It can be reused if objects of the type of the new slot will always
553 conflict with objects of the type of the old slot. */
554 tree type;
555 /* The alignment (in bits) of the slot. */
556 unsigned int align;
557 /* Nonzero if this temporary is currently in use. */
558 char in_use;
559 /* Nesting level at which this slot is being used. */
560 int level;
561 /* The offset of the slot from the frame_pointer, including extra space
562 for alignment. This info is for combine_temp_slots. */
563 HOST_WIDE_INT base_offset;
564 /* The size of the slot, including extra space for alignment. This
565 info is for combine_temp_slots. */
566 HOST_WIDE_INT full_size;
569 /* Entry for the below hash table. */
570 struct GTY((for_user)) temp_slot_address_entry {
571 hashval_t hash;
572 rtx address;
573 struct temp_slot *temp_slot;
576 struct temp_address_hasher : ggc_ptr_hash<temp_slot_address_entry>
578 static hashval_t hash (temp_slot_address_entry *);
579 static bool equal (temp_slot_address_entry *, temp_slot_address_entry *);
582 /* A table of addresses that represent a stack slot. The table is a mapping
583 from address RTXen to a temp slot. */
584 static GTY(()) hash_table<temp_address_hasher> *temp_slot_address_table;
585 static size_t n_temp_slots_in_use;
587 /* Removes temporary slot TEMP from LIST. */
589 static void
590 cut_slot_from_list (struct temp_slot *temp, struct temp_slot **list)
592 if (temp->next)
593 temp->next->prev = temp->prev;
594 if (temp->prev)
595 temp->prev->next = temp->next;
596 else
597 *list = temp->next;
599 temp->prev = temp->next = NULL;
602 /* Inserts temporary slot TEMP to LIST. */
604 static void
605 insert_slot_to_list (struct temp_slot *temp, struct temp_slot **list)
607 temp->next = *list;
608 if (*list)
609 (*list)->prev = temp;
610 temp->prev = NULL;
611 *list = temp;
614 /* Returns the list of used temp slots at LEVEL. */
616 static struct temp_slot **
617 temp_slots_at_level (int level)
619 if (level >= (int) vec_safe_length (used_temp_slots))
620 vec_safe_grow_cleared (used_temp_slots, level + 1);
622 return &(*used_temp_slots)[level];
625 /* Returns the maximal temporary slot level. */
627 static int
628 max_slot_level (void)
630 if (!used_temp_slots)
631 return -1;
633 return used_temp_slots->length () - 1;
636 /* Moves temporary slot TEMP to LEVEL. */
638 static void
639 move_slot_to_level (struct temp_slot *temp, int level)
641 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
642 insert_slot_to_list (temp, temp_slots_at_level (level));
643 temp->level = level;
646 /* Make temporary slot TEMP available. */
648 static void
649 make_slot_available (struct temp_slot *temp)
651 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
652 insert_slot_to_list (temp, &avail_temp_slots);
653 temp->in_use = 0;
654 temp->level = -1;
655 n_temp_slots_in_use--;
658 /* Compute the hash value for an address -> temp slot mapping.
659 The value is cached on the mapping entry. */
660 static hashval_t
661 temp_slot_address_compute_hash (struct temp_slot_address_entry *t)
663 int do_not_record = 0;
664 return hash_rtx (t->address, GET_MODE (t->address),
665 &do_not_record, NULL, false);
668 /* Return the hash value for an address -> temp slot mapping. */
669 hashval_t
670 temp_address_hasher::hash (temp_slot_address_entry *t)
672 return t->hash;
675 /* Compare two address -> temp slot mapping entries. */
676 bool
677 temp_address_hasher::equal (temp_slot_address_entry *t1,
678 temp_slot_address_entry *t2)
680 return exp_equiv_p (t1->address, t2->address, 0, true);
683 /* Add ADDRESS as an alias of TEMP_SLOT to the addess -> temp slot mapping. */
684 static void
685 insert_temp_slot_address (rtx address, struct temp_slot *temp_slot)
687 struct temp_slot_address_entry *t = ggc_alloc<temp_slot_address_entry> ();
688 t->address = address;
689 t->temp_slot = temp_slot;
690 t->hash = temp_slot_address_compute_hash (t);
691 *temp_slot_address_table->find_slot_with_hash (t, t->hash, INSERT) = t;
694 /* Remove an address -> temp slot mapping entry if the temp slot is
695 not in use anymore. Callback for remove_unused_temp_slot_addresses. */
697 remove_unused_temp_slot_addresses_1 (temp_slot_address_entry **slot, void *)
699 const struct temp_slot_address_entry *t = *slot;
700 if (! t->temp_slot->in_use)
701 temp_slot_address_table->clear_slot (slot);
702 return 1;
705 /* Remove all mappings of addresses to unused temp slots. */
706 static void
707 remove_unused_temp_slot_addresses (void)
709 /* Use quicker clearing if there aren't any active temp slots. */
710 if (n_temp_slots_in_use)
711 temp_slot_address_table->traverse
712 <void *, remove_unused_temp_slot_addresses_1> (NULL);
713 else
714 temp_slot_address_table->empty ();
717 /* Find the temp slot corresponding to the object at address X. */
719 static struct temp_slot *
720 find_temp_slot_from_address (rtx x)
722 struct temp_slot *p;
723 struct temp_slot_address_entry tmp, *t;
725 /* First try the easy way:
726 See if X exists in the address -> temp slot mapping. */
727 tmp.address = x;
728 tmp.temp_slot = NULL;
729 tmp.hash = temp_slot_address_compute_hash (&tmp);
730 t = temp_slot_address_table->find_with_hash (&tmp, tmp.hash);
731 if (t)
732 return t->temp_slot;
734 /* If we have a sum involving a register, see if it points to a temp
735 slot. */
736 if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 0))
737 && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
738 return p;
739 else if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 1))
740 && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
741 return p;
743 /* Last resort: Address is a virtual stack var address. */
744 if (GET_CODE (x) == PLUS
745 && XEXP (x, 0) == virtual_stack_vars_rtx
746 && CONST_INT_P (XEXP (x, 1)))
748 int i;
749 for (i = max_slot_level (); i >= 0; i--)
750 for (p = *temp_slots_at_level (i); p; p = p->next)
752 if (INTVAL (XEXP (x, 1)) >= p->base_offset
753 && INTVAL (XEXP (x, 1)) < p->base_offset + p->full_size)
754 return p;
758 return NULL;
761 /* Allocate a temporary stack slot and record it for possible later
762 reuse.
764 MODE is the machine mode to be given to the returned rtx.
766 SIZE is the size in units of the space required. We do no rounding here
767 since assign_stack_local will do any required rounding.
769 TYPE is the type that will be used for the stack slot. */
772 assign_stack_temp_for_type (machine_mode mode, HOST_WIDE_INT size,
773 tree type)
775 unsigned int align;
776 struct temp_slot *p, *best_p = 0, *selected = NULL, **pp;
777 rtx slot;
779 /* If SIZE is -1 it means that somebody tried to allocate a temporary
780 of a variable size. */
781 gcc_assert (size != -1);
783 align = get_stack_local_alignment (type, mode);
785 /* Try to find an available, already-allocated temporary of the proper
786 mode which meets the size and alignment requirements. Choose the
787 smallest one with the closest alignment.
789 If assign_stack_temp is called outside of the tree->rtl expansion,
790 we cannot reuse the stack slots (that may still refer to
791 VIRTUAL_STACK_VARS_REGNUM). */
792 if (!virtuals_instantiated)
794 for (p = avail_temp_slots; p; p = p->next)
796 if (p->align >= align && p->size >= size
797 && GET_MODE (p->slot) == mode
798 && objects_must_conflict_p (p->type, type)
799 && (best_p == 0 || best_p->size > p->size
800 || (best_p->size == p->size && best_p->align > p->align)))
802 if (p->align == align && p->size == size)
804 selected = p;
805 cut_slot_from_list (selected, &avail_temp_slots);
806 best_p = 0;
807 break;
809 best_p = p;
814 /* Make our best, if any, the one to use. */
815 if (best_p)
817 selected = best_p;
818 cut_slot_from_list (selected, &avail_temp_slots);
820 /* If there are enough aligned bytes left over, make them into a new
821 temp_slot so that the extra bytes don't get wasted. Do this only
822 for BLKmode slots, so that we can be sure of the alignment. */
823 if (GET_MODE (best_p->slot) == BLKmode)
825 int alignment = best_p->align / BITS_PER_UNIT;
826 HOST_WIDE_INT rounded_size = CEIL_ROUND (size, alignment);
828 if (best_p->size - rounded_size >= alignment)
830 p = ggc_alloc<temp_slot> ();
831 p->in_use = 0;
832 p->size = best_p->size - rounded_size;
833 p->base_offset = best_p->base_offset + rounded_size;
834 p->full_size = best_p->full_size - rounded_size;
835 p->slot = adjust_address_nv (best_p->slot, BLKmode, rounded_size);
836 p->align = best_p->align;
837 p->type = best_p->type;
838 insert_slot_to_list (p, &avail_temp_slots);
840 vec_safe_push (stack_slot_list, p->slot);
842 best_p->size = rounded_size;
843 best_p->full_size = rounded_size;
848 /* If we still didn't find one, make a new temporary. */
849 if (selected == 0)
851 HOST_WIDE_INT frame_offset_old = frame_offset;
853 p = ggc_alloc<temp_slot> ();
855 /* We are passing an explicit alignment request to assign_stack_local.
856 One side effect of that is assign_stack_local will not round SIZE
857 to ensure the frame offset remains suitably aligned.
859 So for requests which depended on the rounding of SIZE, we go ahead
860 and round it now. We also make sure ALIGNMENT is at least
861 BIGGEST_ALIGNMENT. */
862 gcc_assert (mode != BLKmode || align == BIGGEST_ALIGNMENT);
863 p->slot = assign_stack_local_1 (mode,
864 (mode == BLKmode
865 ? CEIL_ROUND (size,
866 (int) align
867 / BITS_PER_UNIT)
868 : size),
869 align, 0);
871 p->align = align;
873 /* The following slot size computation is necessary because we don't
874 know the actual size of the temporary slot until assign_stack_local
875 has performed all the frame alignment and size rounding for the
876 requested temporary. Note that extra space added for alignment
877 can be either above or below this stack slot depending on which
878 way the frame grows. We include the extra space if and only if it
879 is above this slot. */
880 if (FRAME_GROWS_DOWNWARD)
881 p->size = frame_offset_old - frame_offset;
882 else
883 p->size = size;
885 /* Now define the fields used by combine_temp_slots. */
886 if (FRAME_GROWS_DOWNWARD)
888 p->base_offset = frame_offset;
889 p->full_size = frame_offset_old - frame_offset;
891 else
893 p->base_offset = frame_offset_old;
894 p->full_size = frame_offset - frame_offset_old;
897 selected = p;
900 p = selected;
901 p->in_use = 1;
902 p->type = type;
903 p->level = temp_slot_level;
904 n_temp_slots_in_use++;
906 pp = temp_slots_at_level (p->level);
907 insert_slot_to_list (p, pp);
908 insert_temp_slot_address (XEXP (p->slot, 0), p);
910 /* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
911 slot = gen_rtx_MEM (mode, XEXP (p->slot, 0));
912 vec_safe_push (stack_slot_list, slot);
914 /* If we know the alias set for the memory that will be used, use
915 it. If there's no TYPE, then we don't know anything about the
916 alias set for the memory. */
917 set_mem_alias_set (slot, type ? get_alias_set (type) : 0);
918 set_mem_align (slot, align);
920 /* If a type is specified, set the relevant flags. */
921 if (type != 0)
922 MEM_VOLATILE_P (slot) = TYPE_VOLATILE (type);
923 MEM_NOTRAP_P (slot) = 1;
925 return slot;
928 /* Allocate a temporary stack slot and record it for possible later
929 reuse. First two arguments are same as in preceding function. */
932 assign_stack_temp (machine_mode mode, HOST_WIDE_INT size)
934 return assign_stack_temp_for_type (mode, size, NULL_TREE);
937 /* Assign a temporary.
938 If TYPE_OR_DECL is a decl, then we are doing it on behalf of the decl
939 and so that should be used in error messages. In either case, we
940 allocate of the given type.
941 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
942 it is 0 if a register is OK.
943 DONT_PROMOTE is 1 if we should not promote values in register
944 to wider modes. */
947 assign_temp (tree type_or_decl, int memory_required,
948 int dont_promote ATTRIBUTE_UNUSED)
950 tree type, decl;
951 machine_mode mode;
952 #ifdef PROMOTE_MODE
953 int unsignedp;
954 #endif
956 if (DECL_P (type_or_decl))
957 decl = type_or_decl, type = TREE_TYPE (decl);
958 else
959 decl = NULL, type = type_or_decl;
961 mode = TYPE_MODE (type);
962 #ifdef PROMOTE_MODE
963 unsignedp = TYPE_UNSIGNED (type);
964 #endif
966 /* Allocating temporaries of TREE_ADDRESSABLE type must be done in the front
967 end. See also create_tmp_var for the gimplification-time check. */
968 gcc_assert (!TREE_ADDRESSABLE (type) && COMPLETE_TYPE_P (type));
970 if (mode == BLKmode || memory_required)
972 HOST_WIDE_INT size = int_size_in_bytes (type);
973 rtx tmp;
975 /* Zero sized arrays are GNU C extension. Set size to 1 to avoid
976 problems with allocating the stack space. */
977 if (size == 0)
978 size = 1;
980 /* Unfortunately, we don't yet know how to allocate variable-sized
981 temporaries. However, sometimes we can find a fixed upper limit on
982 the size, so try that instead. */
983 else if (size == -1)
984 size = max_int_size_in_bytes (type);
986 /* The size of the temporary may be too large to fit into an integer. */
987 /* ??? Not sure this should happen except for user silliness, so limit
988 this to things that aren't compiler-generated temporaries. The
989 rest of the time we'll die in assign_stack_temp_for_type. */
990 if (decl && size == -1
991 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST)
993 error ("size of variable %q+D is too large", decl);
994 size = 1;
997 tmp = assign_stack_temp_for_type (mode, size, type);
998 return tmp;
1001 #ifdef PROMOTE_MODE
1002 if (! dont_promote)
1003 mode = promote_mode (type, mode, &unsignedp);
1004 #endif
1006 return gen_reg_rtx (mode);
1009 /* Combine temporary stack slots which are adjacent on the stack.
1011 This allows for better use of already allocated stack space. This is only
1012 done for BLKmode slots because we can be sure that we won't have alignment
1013 problems in this case. */
1015 static void
1016 combine_temp_slots (void)
1018 struct temp_slot *p, *q, *next, *next_q;
1019 int num_slots;
1021 /* We can't combine slots, because the information about which slot
1022 is in which alias set will be lost. */
1023 if (flag_strict_aliasing)
1024 return;
1026 /* If there are a lot of temp slots, don't do anything unless
1027 high levels of optimization. */
1028 if (! flag_expensive_optimizations)
1029 for (p = avail_temp_slots, num_slots = 0; p; p = p->next, num_slots++)
1030 if (num_slots > 100 || (num_slots > 10 && optimize == 0))
1031 return;
1033 for (p = avail_temp_slots; p; p = next)
1035 int delete_p = 0;
1037 next = p->next;
1039 if (GET_MODE (p->slot) != BLKmode)
1040 continue;
1042 for (q = p->next; q; q = next_q)
1044 int delete_q = 0;
1046 next_q = q->next;
1048 if (GET_MODE (q->slot) != BLKmode)
1049 continue;
1051 if (p->base_offset + p->full_size == q->base_offset)
1053 /* Q comes after P; combine Q into P. */
1054 p->size += q->size;
1055 p->full_size += q->full_size;
1056 delete_q = 1;
1058 else if (q->base_offset + q->full_size == p->base_offset)
1060 /* P comes after Q; combine P into Q. */
1061 q->size += p->size;
1062 q->full_size += p->full_size;
1063 delete_p = 1;
1064 break;
1066 if (delete_q)
1067 cut_slot_from_list (q, &avail_temp_slots);
1070 /* Either delete P or advance past it. */
1071 if (delete_p)
1072 cut_slot_from_list (p, &avail_temp_slots);
1076 /* Indicate that NEW_RTX is an alternate way of referring to the temp
1077 slot that previously was known by OLD_RTX. */
1079 void
1080 update_temp_slot_address (rtx old_rtx, rtx new_rtx)
1082 struct temp_slot *p;
1084 if (rtx_equal_p (old_rtx, new_rtx))
1085 return;
1087 p = find_temp_slot_from_address (old_rtx);
1089 /* If we didn't find one, see if both OLD_RTX is a PLUS. If so, and
1090 NEW_RTX is a register, see if one operand of the PLUS is a
1091 temporary location. If so, NEW_RTX points into it. Otherwise,
1092 if both OLD_RTX and NEW_RTX are a PLUS and if there is a register
1093 in common between them. If so, try a recursive call on those
1094 values. */
1095 if (p == 0)
1097 if (GET_CODE (old_rtx) != PLUS)
1098 return;
1100 if (REG_P (new_rtx))
1102 update_temp_slot_address (XEXP (old_rtx, 0), new_rtx);
1103 update_temp_slot_address (XEXP (old_rtx, 1), new_rtx);
1104 return;
1106 else if (GET_CODE (new_rtx) != PLUS)
1107 return;
1109 if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 0)))
1110 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 1));
1111 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 0)))
1112 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 1));
1113 else if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 1)))
1114 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 0));
1115 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 1)))
1116 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 0));
1118 return;
1121 /* Otherwise add an alias for the temp's address. */
1122 insert_temp_slot_address (new_rtx, p);
1125 /* If X could be a reference to a temporary slot, mark that slot as
1126 belonging to the to one level higher than the current level. If X
1127 matched one of our slots, just mark that one. Otherwise, we can't
1128 easily predict which it is, so upgrade all of them.
1130 This is called when an ({...}) construct occurs and a statement
1131 returns a value in memory. */
1133 void
1134 preserve_temp_slots (rtx x)
1136 struct temp_slot *p = 0, *next;
1138 if (x == 0)
1139 return;
1141 /* If X is a register that is being used as a pointer, see if we have
1142 a temporary slot we know it points to. */
1143 if (REG_P (x) && REG_POINTER (x))
1144 p = find_temp_slot_from_address (x);
1146 /* If X is not in memory or is at a constant address, it cannot be in
1147 a temporary slot. */
1148 if (p == 0 && (!MEM_P (x) || CONSTANT_P (XEXP (x, 0))))
1149 return;
1151 /* First see if we can find a match. */
1152 if (p == 0)
1153 p = find_temp_slot_from_address (XEXP (x, 0));
1155 if (p != 0)
1157 if (p->level == temp_slot_level)
1158 move_slot_to_level (p, temp_slot_level - 1);
1159 return;
1162 /* Otherwise, preserve all non-kept slots at this level. */
1163 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1165 next = p->next;
1166 move_slot_to_level (p, temp_slot_level - 1);
1170 /* Free all temporaries used so far. This is normally called at the
1171 end of generating code for a statement. */
1173 void
1174 free_temp_slots (void)
1176 struct temp_slot *p, *next;
1177 bool some_available = false;
1179 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1181 next = p->next;
1182 make_slot_available (p);
1183 some_available = true;
1186 if (some_available)
1188 remove_unused_temp_slot_addresses ();
1189 combine_temp_slots ();
1193 /* Push deeper into the nesting level for stack temporaries. */
1195 void
1196 push_temp_slots (void)
1198 temp_slot_level++;
1201 /* Pop a temporary nesting level. All slots in use in the current level
1202 are freed. */
1204 void
1205 pop_temp_slots (void)
1207 free_temp_slots ();
1208 temp_slot_level--;
1211 /* Initialize temporary slots. */
1213 void
1214 init_temp_slots (void)
1216 /* We have not allocated any temporaries yet. */
1217 avail_temp_slots = 0;
1218 vec_alloc (used_temp_slots, 0);
1219 temp_slot_level = 0;
1220 n_temp_slots_in_use = 0;
1222 /* Set up the table to map addresses to temp slots. */
1223 if (! temp_slot_address_table)
1224 temp_slot_address_table = hash_table<temp_address_hasher>::create_ggc (32);
1225 else
1226 temp_slot_address_table->empty ();
1229 /* Functions and data structures to keep track of the values hard regs
1230 had at the start of the function. */
1232 /* Private type used by get_hard_reg_initial_reg, get_hard_reg_initial_val,
1233 and has_hard_reg_initial_val.. */
1234 struct GTY(()) initial_value_pair {
1235 rtx hard_reg;
1236 rtx pseudo;
1238 /* ??? This could be a VEC but there is currently no way to define an
1239 opaque VEC type. This could be worked around by defining struct
1240 initial_value_pair in function.h. */
1241 struct GTY(()) initial_value_struct {
1242 int num_entries;
1243 int max_entries;
1244 initial_value_pair * GTY ((length ("%h.num_entries"))) entries;
1247 /* If a pseudo represents an initial hard reg (or expression), return
1248 it, else return NULL_RTX. */
1251 get_hard_reg_initial_reg (rtx reg)
1253 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1254 int i;
1256 if (ivs == 0)
1257 return NULL_RTX;
1259 for (i = 0; i < ivs->num_entries; i++)
1260 if (rtx_equal_p (ivs->entries[i].pseudo, reg))
1261 return ivs->entries[i].hard_reg;
1263 return NULL_RTX;
1266 /* Make sure that there's a pseudo register of mode MODE that stores the
1267 initial value of hard register REGNO. Return an rtx for such a pseudo. */
1270 get_hard_reg_initial_val (machine_mode mode, unsigned int regno)
1272 struct initial_value_struct *ivs;
1273 rtx rv;
1275 rv = has_hard_reg_initial_val (mode, regno);
1276 if (rv)
1277 return rv;
1279 ivs = crtl->hard_reg_initial_vals;
1280 if (ivs == 0)
1282 ivs = ggc_alloc<initial_value_struct> ();
1283 ivs->num_entries = 0;
1284 ivs->max_entries = 5;
1285 ivs->entries = ggc_vec_alloc<initial_value_pair> (5);
1286 crtl->hard_reg_initial_vals = ivs;
1289 if (ivs->num_entries >= ivs->max_entries)
1291 ivs->max_entries += 5;
1292 ivs->entries = GGC_RESIZEVEC (initial_value_pair, ivs->entries,
1293 ivs->max_entries);
1296 ivs->entries[ivs->num_entries].hard_reg = gen_rtx_REG (mode, regno);
1297 ivs->entries[ivs->num_entries].pseudo = gen_reg_rtx (mode);
1299 return ivs->entries[ivs->num_entries++].pseudo;
1302 /* See if get_hard_reg_initial_val has been used to create a pseudo
1303 for the initial value of hard register REGNO in mode MODE. Return
1304 the associated pseudo if so, otherwise return NULL. */
1307 has_hard_reg_initial_val (machine_mode mode, unsigned int regno)
1309 struct initial_value_struct *ivs;
1310 int i;
1312 ivs = crtl->hard_reg_initial_vals;
1313 if (ivs != 0)
1314 for (i = 0; i < ivs->num_entries; i++)
1315 if (GET_MODE (ivs->entries[i].hard_reg) == mode
1316 && REGNO (ivs->entries[i].hard_reg) == regno)
1317 return ivs->entries[i].pseudo;
1319 return NULL_RTX;
1322 unsigned int
1323 emit_initial_value_sets (void)
1325 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1326 int i;
1327 rtx_insn *seq;
1329 if (ivs == 0)
1330 return 0;
1332 start_sequence ();
1333 for (i = 0; i < ivs->num_entries; i++)
1334 emit_move_insn (ivs->entries[i].pseudo, ivs->entries[i].hard_reg);
1335 seq = get_insns ();
1336 end_sequence ();
1338 emit_insn_at_entry (seq);
1339 return 0;
1342 /* Return the hardreg-pseudoreg initial values pair entry I and
1343 TRUE if I is a valid entry, or FALSE if I is not a valid entry. */
1344 bool
1345 initial_value_entry (int i, rtx *hreg, rtx *preg)
1347 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1348 if (!ivs || i >= ivs->num_entries)
1349 return false;
1351 *hreg = ivs->entries[i].hard_reg;
1352 *preg = ivs->entries[i].pseudo;
1353 return true;
1356 /* These routines are responsible for converting virtual register references
1357 to the actual hard register references once RTL generation is complete.
1359 The following four variables are used for communication between the
1360 routines. They contain the offsets of the virtual registers from their
1361 respective hard registers. */
1363 static int in_arg_offset;
1364 static int var_offset;
1365 static int dynamic_offset;
1366 static int out_arg_offset;
1367 static int cfa_offset;
1369 /* In most machines, the stack pointer register is equivalent to the bottom
1370 of the stack. */
1372 #ifndef STACK_POINTER_OFFSET
1373 #define STACK_POINTER_OFFSET 0
1374 #endif
1376 #if defined (REG_PARM_STACK_SPACE) && !defined (INCOMING_REG_PARM_STACK_SPACE)
1377 #define INCOMING_REG_PARM_STACK_SPACE REG_PARM_STACK_SPACE
1378 #endif
1380 /* If not defined, pick an appropriate default for the offset of dynamically
1381 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
1382 INCOMING_REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
1384 #ifndef STACK_DYNAMIC_OFFSET
1386 /* The bottom of the stack points to the actual arguments. If
1387 REG_PARM_STACK_SPACE is defined, this includes the space for the register
1388 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
1389 stack space for register parameters is not pushed by the caller, but
1390 rather part of the fixed stack areas and hence not included in
1391 `crtl->outgoing_args_size'. Nevertheless, we must allow
1392 for it when allocating stack dynamic objects. */
1394 #ifdef INCOMING_REG_PARM_STACK_SPACE
1395 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1396 ((ACCUMULATE_OUTGOING_ARGS \
1397 ? (crtl->outgoing_args_size \
1398 + (OUTGOING_REG_PARM_STACK_SPACE ((!(FNDECL) ? NULL_TREE : TREE_TYPE (FNDECL))) ? 0 \
1399 : INCOMING_REG_PARM_STACK_SPACE (FNDECL))) \
1400 : 0) + (STACK_POINTER_OFFSET))
1401 #else
1402 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1403 ((ACCUMULATE_OUTGOING_ARGS ? crtl->outgoing_args_size : 0) \
1404 + (STACK_POINTER_OFFSET))
1405 #endif
1406 #endif
1409 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
1410 is a virtual register, return the equivalent hard register and set the
1411 offset indirectly through the pointer. Otherwise, return 0. */
1413 static rtx
1414 instantiate_new_reg (rtx x, HOST_WIDE_INT *poffset)
1416 rtx new_rtx;
1417 HOST_WIDE_INT offset;
1419 if (x == virtual_incoming_args_rtx)
1421 if (stack_realign_drap)
1423 /* Replace virtual_incoming_args_rtx with internal arg
1424 pointer if DRAP is used to realign stack. */
1425 new_rtx = crtl->args.internal_arg_pointer;
1426 offset = 0;
1428 else
1429 new_rtx = arg_pointer_rtx, offset = in_arg_offset;
1431 else if (x == virtual_stack_vars_rtx)
1432 new_rtx = frame_pointer_rtx, offset = var_offset;
1433 else if (x == virtual_stack_dynamic_rtx)
1434 new_rtx = stack_pointer_rtx, offset = dynamic_offset;
1435 else if (x == virtual_outgoing_args_rtx)
1436 new_rtx = stack_pointer_rtx, offset = out_arg_offset;
1437 else if (x == virtual_cfa_rtx)
1439 #ifdef FRAME_POINTER_CFA_OFFSET
1440 new_rtx = frame_pointer_rtx;
1441 #else
1442 new_rtx = arg_pointer_rtx;
1443 #endif
1444 offset = cfa_offset;
1446 else if (x == virtual_preferred_stack_boundary_rtx)
1448 new_rtx = GEN_INT (crtl->preferred_stack_boundary / BITS_PER_UNIT);
1449 offset = 0;
1451 else
1452 return NULL_RTX;
1454 *poffset = offset;
1455 return new_rtx;
1458 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1459 registers present inside of *LOC. The expression is simplified,
1460 as much as possible, but is not to be considered "valid" in any sense
1461 implied by the target. Return true if any change is made. */
1463 static bool
1464 instantiate_virtual_regs_in_rtx (rtx *loc)
1466 if (!*loc)
1467 return false;
1468 bool changed = false;
1469 subrtx_ptr_iterator::array_type array;
1470 FOR_EACH_SUBRTX_PTR (iter, array, loc, NONCONST)
1472 rtx *loc = *iter;
1473 if (rtx x = *loc)
1475 rtx new_rtx;
1476 HOST_WIDE_INT offset;
1477 switch (GET_CODE (x))
1479 case REG:
1480 new_rtx = instantiate_new_reg (x, &offset);
1481 if (new_rtx)
1483 *loc = plus_constant (GET_MODE (x), new_rtx, offset);
1484 changed = true;
1486 iter.skip_subrtxes ();
1487 break;
1489 case PLUS:
1490 new_rtx = instantiate_new_reg (XEXP (x, 0), &offset);
1491 if (new_rtx)
1493 XEXP (x, 0) = new_rtx;
1494 *loc = plus_constant (GET_MODE (x), x, offset, true);
1495 changed = true;
1496 iter.skip_subrtxes ();
1497 break;
1500 /* FIXME -- from old code */
1501 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
1502 we can commute the PLUS and SUBREG because pointers into the
1503 frame are well-behaved. */
1504 break;
1506 default:
1507 break;
1511 return changed;
1514 /* A subroutine of instantiate_virtual_regs_in_insn. Return true if X
1515 matches the predicate for insn CODE operand OPERAND. */
1517 static int
1518 safe_insn_predicate (int code, int operand, rtx x)
1520 return code < 0 || insn_operand_matches ((enum insn_code) code, operand, x);
1523 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1524 registers present inside of insn. The result will be a valid insn. */
1526 static void
1527 instantiate_virtual_regs_in_insn (rtx_insn *insn)
1529 HOST_WIDE_INT offset;
1530 int insn_code, i;
1531 bool any_change = false;
1532 rtx set, new_rtx, x;
1533 rtx_insn *seq;
1535 /* There are some special cases to be handled first. */
1536 set = single_set (insn);
1537 if (set)
1539 /* We're allowed to assign to a virtual register. This is interpreted
1540 to mean that the underlying register gets assigned the inverse
1541 transformation. This is used, for example, in the handling of
1542 non-local gotos. */
1543 new_rtx = instantiate_new_reg (SET_DEST (set), &offset);
1544 if (new_rtx)
1546 start_sequence ();
1548 instantiate_virtual_regs_in_rtx (&SET_SRC (set));
1549 x = simplify_gen_binary (PLUS, GET_MODE (new_rtx), SET_SRC (set),
1550 gen_int_mode (-offset, GET_MODE (new_rtx)));
1551 x = force_operand (x, new_rtx);
1552 if (x != new_rtx)
1553 emit_move_insn (new_rtx, x);
1555 seq = get_insns ();
1556 end_sequence ();
1558 emit_insn_before (seq, insn);
1559 delete_insn (insn);
1560 return;
1563 /* Handle a straight copy from a virtual register by generating a
1564 new add insn. The difference between this and falling through
1565 to the generic case is avoiding a new pseudo and eliminating a
1566 move insn in the initial rtl stream. */
1567 new_rtx = instantiate_new_reg (SET_SRC (set), &offset);
1568 if (new_rtx && offset != 0
1569 && REG_P (SET_DEST (set))
1570 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1572 start_sequence ();
1574 x = expand_simple_binop (GET_MODE (SET_DEST (set)), PLUS, new_rtx,
1575 gen_int_mode (offset,
1576 GET_MODE (SET_DEST (set))),
1577 SET_DEST (set), 1, OPTAB_LIB_WIDEN);
1578 if (x != SET_DEST (set))
1579 emit_move_insn (SET_DEST (set), x);
1581 seq = get_insns ();
1582 end_sequence ();
1584 emit_insn_before (seq, insn);
1585 delete_insn (insn);
1586 return;
1589 extract_insn (insn);
1590 insn_code = INSN_CODE (insn);
1592 /* Handle a plus involving a virtual register by determining if the
1593 operands remain valid if they're modified in place. */
1594 if (GET_CODE (SET_SRC (set)) == PLUS
1595 && recog_data.n_operands >= 3
1596 && recog_data.operand_loc[1] == &XEXP (SET_SRC (set), 0)
1597 && recog_data.operand_loc[2] == &XEXP (SET_SRC (set), 1)
1598 && CONST_INT_P (recog_data.operand[2])
1599 && (new_rtx = instantiate_new_reg (recog_data.operand[1], &offset)))
1601 offset += INTVAL (recog_data.operand[2]);
1603 /* If the sum is zero, then replace with a plain move. */
1604 if (offset == 0
1605 && REG_P (SET_DEST (set))
1606 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1608 start_sequence ();
1609 emit_move_insn (SET_DEST (set), new_rtx);
1610 seq = get_insns ();
1611 end_sequence ();
1613 emit_insn_before (seq, insn);
1614 delete_insn (insn);
1615 return;
1618 x = gen_int_mode (offset, recog_data.operand_mode[2]);
1620 /* Using validate_change and apply_change_group here leaves
1621 recog_data in an invalid state. Since we know exactly what
1622 we want to check, do those two by hand. */
1623 if (safe_insn_predicate (insn_code, 1, new_rtx)
1624 && safe_insn_predicate (insn_code, 2, x))
1626 *recog_data.operand_loc[1] = recog_data.operand[1] = new_rtx;
1627 *recog_data.operand_loc[2] = recog_data.operand[2] = x;
1628 any_change = true;
1630 /* Fall through into the regular operand fixup loop in
1631 order to take care of operands other than 1 and 2. */
1635 else
1637 extract_insn (insn);
1638 insn_code = INSN_CODE (insn);
1641 /* In the general case, we expect virtual registers to appear only in
1642 operands, and then only as either bare registers or inside memories. */
1643 for (i = 0; i < recog_data.n_operands; ++i)
1645 x = recog_data.operand[i];
1646 switch (GET_CODE (x))
1648 case MEM:
1650 rtx addr = XEXP (x, 0);
1652 if (!instantiate_virtual_regs_in_rtx (&addr))
1653 continue;
1655 start_sequence ();
1656 x = replace_equiv_address (x, addr, true);
1657 /* It may happen that the address with the virtual reg
1658 was valid (e.g. based on the virtual stack reg, which might
1659 be acceptable to the predicates with all offsets), whereas
1660 the address now isn't anymore, for instance when the address
1661 is still offsetted, but the base reg isn't virtual-stack-reg
1662 anymore. Below we would do a force_reg on the whole operand,
1663 but this insn might actually only accept memory. Hence,
1664 before doing that last resort, try to reload the address into
1665 a register, so this operand stays a MEM. */
1666 if (!safe_insn_predicate (insn_code, i, x))
1668 addr = force_reg (GET_MODE (addr), addr);
1669 x = replace_equiv_address (x, addr, true);
1671 seq = get_insns ();
1672 end_sequence ();
1673 if (seq)
1674 emit_insn_before (seq, insn);
1676 break;
1678 case REG:
1679 new_rtx = instantiate_new_reg (x, &offset);
1680 if (new_rtx == NULL)
1681 continue;
1682 if (offset == 0)
1683 x = new_rtx;
1684 else
1686 start_sequence ();
1688 /* Careful, special mode predicates may have stuff in
1689 insn_data[insn_code].operand[i].mode that isn't useful
1690 to us for computing a new value. */
1691 /* ??? Recognize address_operand and/or "p" constraints
1692 to see if (plus new offset) is a valid before we put
1693 this through expand_simple_binop. */
1694 x = expand_simple_binop (GET_MODE (x), PLUS, new_rtx,
1695 gen_int_mode (offset, GET_MODE (x)),
1696 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1697 seq = get_insns ();
1698 end_sequence ();
1699 emit_insn_before (seq, insn);
1701 break;
1703 case SUBREG:
1704 new_rtx = instantiate_new_reg (SUBREG_REG (x), &offset);
1705 if (new_rtx == NULL)
1706 continue;
1707 if (offset != 0)
1709 start_sequence ();
1710 new_rtx = expand_simple_binop
1711 (GET_MODE (new_rtx), PLUS, new_rtx,
1712 gen_int_mode (offset, GET_MODE (new_rtx)),
1713 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1714 seq = get_insns ();
1715 end_sequence ();
1716 emit_insn_before (seq, insn);
1718 x = simplify_gen_subreg (recog_data.operand_mode[i], new_rtx,
1719 GET_MODE (new_rtx), SUBREG_BYTE (x));
1720 gcc_assert (x);
1721 break;
1723 default:
1724 continue;
1727 /* At this point, X contains the new value for the operand.
1728 Validate the new value vs the insn predicate. Note that
1729 asm insns will have insn_code -1 here. */
1730 if (!safe_insn_predicate (insn_code, i, x))
1732 start_sequence ();
1733 if (REG_P (x))
1735 gcc_assert (REGNO (x) <= LAST_VIRTUAL_REGISTER);
1736 x = copy_to_reg (x);
1738 else
1739 x = force_reg (insn_data[insn_code].operand[i].mode, x);
1740 seq = get_insns ();
1741 end_sequence ();
1742 if (seq)
1743 emit_insn_before (seq, insn);
1746 *recog_data.operand_loc[i] = recog_data.operand[i] = x;
1747 any_change = true;
1750 if (any_change)
1752 /* Propagate operand changes into the duplicates. */
1753 for (i = 0; i < recog_data.n_dups; ++i)
1754 *recog_data.dup_loc[i]
1755 = copy_rtx (recog_data.operand[(unsigned)recog_data.dup_num[i]]);
1757 /* Force re-recognition of the instruction for validation. */
1758 INSN_CODE (insn) = -1;
1761 if (asm_noperands (PATTERN (insn)) >= 0)
1763 if (!check_asm_operands (PATTERN (insn)))
1765 error_for_asm (insn, "impossible constraint in %<asm%>");
1766 /* For asm goto, instead of fixing up all the edges
1767 just clear the template and clear input operands
1768 (asm goto doesn't have any output operands). */
1769 if (JUMP_P (insn))
1771 rtx asm_op = extract_asm_operands (PATTERN (insn));
1772 ASM_OPERANDS_TEMPLATE (asm_op) = ggc_strdup ("");
1773 ASM_OPERANDS_INPUT_VEC (asm_op) = rtvec_alloc (0);
1774 ASM_OPERANDS_INPUT_CONSTRAINT_VEC (asm_op) = rtvec_alloc (0);
1776 else
1777 delete_insn (insn);
1780 else
1782 if (recog_memoized (insn) < 0)
1783 fatal_insn_not_found (insn);
1787 /* Subroutine of instantiate_decls. Given RTL representing a decl,
1788 do any instantiation required. */
1790 void
1791 instantiate_decl_rtl (rtx x)
1793 rtx addr;
1795 if (x == 0)
1796 return;
1798 /* If this is a CONCAT, recurse for the pieces. */
1799 if (GET_CODE (x) == CONCAT)
1801 instantiate_decl_rtl (XEXP (x, 0));
1802 instantiate_decl_rtl (XEXP (x, 1));
1803 return;
1806 /* If this is not a MEM, no need to do anything. Similarly if the
1807 address is a constant or a register that is not a virtual register. */
1808 if (!MEM_P (x))
1809 return;
1811 addr = XEXP (x, 0);
1812 if (CONSTANT_P (addr)
1813 || (REG_P (addr)
1814 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
1815 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
1816 return;
1818 instantiate_virtual_regs_in_rtx (&XEXP (x, 0));
1821 /* Helper for instantiate_decls called via walk_tree: Process all decls
1822 in the given DECL_VALUE_EXPR. */
1824 static tree
1825 instantiate_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1827 tree t = *tp;
1828 if (! EXPR_P (t))
1830 *walk_subtrees = 0;
1831 if (DECL_P (t))
1833 if (DECL_RTL_SET_P (t))
1834 instantiate_decl_rtl (DECL_RTL (t));
1835 if (TREE_CODE (t) == PARM_DECL && DECL_NAMELESS (t)
1836 && DECL_INCOMING_RTL (t))
1837 instantiate_decl_rtl (DECL_INCOMING_RTL (t));
1838 if ((VAR_P (t) || TREE_CODE (t) == RESULT_DECL)
1839 && DECL_HAS_VALUE_EXPR_P (t))
1841 tree v = DECL_VALUE_EXPR (t);
1842 walk_tree (&v, instantiate_expr, NULL, NULL);
1846 return NULL;
1849 /* Subroutine of instantiate_decls: Process all decls in the given
1850 BLOCK node and all its subblocks. */
1852 static void
1853 instantiate_decls_1 (tree let)
1855 tree t;
1857 for (t = BLOCK_VARS (let); t; t = DECL_CHAIN (t))
1859 if (DECL_RTL_SET_P (t))
1860 instantiate_decl_rtl (DECL_RTL (t));
1861 if (VAR_P (t) && DECL_HAS_VALUE_EXPR_P (t))
1863 tree v = DECL_VALUE_EXPR (t);
1864 walk_tree (&v, instantiate_expr, NULL, NULL);
1868 /* Process all subblocks. */
1869 for (t = BLOCK_SUBBLOCKS (let); t; t = BLOCK_CHAIN (t))
1870 instantiate_decls_1 (t);
1873 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1874 all virtual registers in their DECL_RTL's. */
1876 static void
1877 instantiate_decls (tree fndecl)
1879 tree decl;
1880 unsigned ix;
1882 /* Process all parameters of the function. */
1883 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = DECL_CHAIN (decl))
1885 instantiate_decl_rtl (DECL_RTL (decl));
1886 instantiate_decl_rtl (DECL_INCOMING_RTL (decl));
1887 if (DECL_HAS_VALUE_EXPR_P (decl))
1889 tree v = DECL_VALUE_EXPR (decl);
1890 walk_tree (&v, instantiate_expr, NULL, NULL);
1894 if ((decl = DECL_RESULT (fndecl))
1895 && TREE_CODE (decl) == RESULT_DECL)
1897 if (DECL_RTL_SET_P (decl))
1898 instantiate_decl_rtl (DECL_RTL (decl));
1899 if (DECL_HAS_VALUE_EXPR_P (decl))
1901 tree v = DECL_VALUE_EXPR (decl);
1902 walk_tree (&v, instantiate_expr, NULL, NULL);
1906 /* Process the saved static chain if it exists. */
1907 decl = DECL_STRUCT_FUNCTION (fndecl)->static_chain_decl;
1908 if (decl && DECL_HAS_VALUE_EXPR_P (decl))
1909 instantiate_decl_rtl (DECL_RTL (DECL_VALUE_EXPR (decl)));
1911 /* Now process all variables defined in the function or its subblocks. */
1912 if (DECL_INITIAL (fndecl))
1913 instantiate_decls_1 (DECL_INITIAL (fndecl));
1915 FOR_EACH_LOCAL_DECL (cfun, ix, decl)
1916 if (DECL_RTL_SET_P (decl))
1917 instantiate_decl_rtl (DECL_RTL (decl));
1918 vec_free (cfun->local_decls);
1921 /* Pass through the INSNS of function FNDECL and convert virtual register
1922 references to hard register references. */
1924 static unsigned int
1925 instantiate_virtual_regs (void)
1927 rtx_insn *insn;
1929 /* Compute the offsets to use for this function. */
1930 in_arg_offset = FIRST_PARM_OFFSET (current_function_decl);
1931 var_offset = STARTING_FRAME_OFFSET;
1932 dynamic_offset = STACK_DYNAMIC_OFFSET (current_function_decl);
1933 out_arg_offset = STACK_POINTER_OFFSET;
1934 #ifdef FRAME_POINTER_CFA_OFFSET
1935 cfa_offset = FRAME_POINTER_CFA_OFFSET (current_function_decl);
1936 #else
1937 cfa_offset = ARG_POINTER_CFA_OFFSET (current_function_decl);
1938 #endif
1940 /* Initialize recognition, indicating that volatile is OK. */
1941 init_recog ();
1943 /* Scan through all the insns, instantiating every virtual register still
1944 present. */
1945 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
1946 if (INSN_P (insn))
1948 /* These patterns in the instruction stream can never be recognized.
1949 Fortunately, they shouldn't contain virtual registers either. */
1950 if (GET_CODE (PATTERN (insn)) == USE
1951 || GET_CODE (PATTERN (insn)) == CLOBBER
1952 || GET_CODE (PATTERN (insn)) == ASM_INPUT)
1953 continue;
1954 else if (DEBUG_INSN_P (insn))
1955 instantiate_virtual_regs_in_rtx (&INSN_VAR_LOCATION (insn));
1956 else
1957 instantiate_virtual_regs_in_insn (insn);
1959 if (insn->deleted ())
1960 continue;
1962 instantiate_virtual_regs_in_rtx (&REG_NOTES (insn));
1964 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
1965 if (CALL_P (insn))
1966 instantiate_virtual_regs_in_rtx (&CALL_INSN_FUNCTION_USAGE (insn));
1969 /* Instantiate the virtual registers in the DECLs for debugging purposes. */
1970 instantiate_decls (current_function_decl);
1972 targetm.instantiate_decls ();
1974 /* Indicate that, from now on, assign_stack_local should use
1975 frame_pointer_rtx. */
1976 virtuals_instantiated = 1;
1978 return 0;
1981 namespace {
1983 const pass_data pass_data_instantiate_virtual_regs =
1985 RTL_PASS, /* type */
1986 "vregs", /* name */
1987 OPTGROUP_NONE, /* optinfo_flags */
1988 TV_NONE, /* tv_id */
1989 0, /* properties_required */
1990 0, /* properties_provided */
1991 0, /* properties_destroyed */
1992 0, /* todo_flags_start */
1993 0, /* todo_flags_finish */
1996 class pass_instantiate_virtual_regs : public rtl_opt_pass
1998 public:
1999 pass_instantiate_virtual_regs (gcc::context *ctxt)
2000 : rtl_opt_pass (pass_data_instantiate_virtual_regs, ctxt)
2003 /* opt_pass methods: */
2004 virtual unsigned int execute (function *)
2006 return instantiate_virtual_regs ();
2009 }; // class pass_instantiate_virtual_regs
2011 } // anon namespace
2013 rtl_opt_pass *
2014 make_pass_instantiate_virtual_regs (gcc::context *ctxt)
2016 return new pass_instantiate_virtual_regs (ctxt);
2020 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
2021 This means a type for which function calls must pass an address to the
2022 function or get an address back from the function.
2023 EXP may be a type node or an expression (whose type is tested). */
2026 aggregate_value_p (const_tree exp, const_tree fntype)
2028 const_tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
2029 int i, regno, nregs;
2030 rtx reg;
2032 if (fntype)
2033 switch (TREE_CODE (fntype))
2035 case CALL_EXPR:
2037 tree fndecl = get_callee_fndecl (fntype);
2038 if (fndecl)
2039 fntype = TREE_TYPE (fndecl);
2040 else if (CALL_EXPR_FN (fntype))
2041 fntype = TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (fntype)));
2042 else
2043 /* For internal functions, assume nothing needs to be
2044 returned in memory. */
2045 return 0;
2047 break;
2048 case FUNCTION_DECL:
2049 fntype = TREE_TYPE (fntype);
2050 break;
2051 case FUNCTION_TYPE:
2052 case METHOD_TYPE:
2053 break;
2054 case IDENTIFIER_NODE:
2055 fntype = NULL_TREE;
2056 break;
2057 default:
2058 /* We don't expect other tree types here. */
2059 gcc_unreachable ();
2062 if (VOID_TYPE_P (type))
2063 return 0;
2065 /* If a record should be passed the same as its first (and only) member
2066 don't pass it as an aggregate. */
2067 if (TREE_CODE (type) == RECORD_TYPE && TYPE_TRANSPARENT_AGGR (type))
2068 return aggregate_value_p (first_field (type), fntype);
2070 /* If the front end has decided that this needs to be passed by
2071 reference, do so. */
2072 if ((TREE_CODE (exp) == PARM_DECL || TREE_CODE (exp) == RESULT_DECL)
2073 && DECL_BY_REFERENCE (exp))
2074 return 1;
2076 /* Function types that are TREE_ADDRESSABLE force return in memory. */
2077 if (fntype && TREE_ADDRESSABLE (fntype))
2078 return 1;
2080 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
2081 and thus can't be returned in registers. */
2082 if (TREE_ADDRESSABLE (type))
2083 return 1;
2085 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
2086 return 1;
2088 if (targetm.calls.return_in_memory (type, fntype))
2089 return 1;
2091 /* Make sure we have suitable call-clobbered regs to return
2092 the value in; if not, we must return it in memory. */
2093 reg = hard_function_value (type, 0, fntype, 0);
2095 /* If we have something other than a REG (e.g. a PARALLEL), then assume
2096 it is OK. */
2097 if (!REG_P (reg))
2098 return 0;
2100 regno = REGNO (reg);
2101 nregs = hard_regno_nregs[regno][TYPE_MODE (type)];
2102 for (i = 0; i < nregs; i++)
2103 if (! call_used_regs[regno + i])
2104 return 1;
2106 return 0;
2109 /* Return true if we should assign DECL a pseudo register; false if it
2110 should live on the local stack. */
2112 bool
2113 use_register_for_decl (const_tree decl)
2115 if (TREE_CODE (decl) == SSA_NAME)
2117 /* We often try to use the SSA_NAME, instead of its underlying
2118 decl, to get type information and guide decisions, to avoid
2119 differences of behavior between anonymous and named
2120 variables, but in this one case we have to go for the actual
2121 variable if there is one. The main reason is that, at least
2122 at -O0, we want to place user variables on the stack, but we
2123 don't mind using pseudos for anonymous or ignored temps.
2124 Should we take the SSA_NAME, we'd conclude all SSA_NAMEs
2125 should go in pseudos, whereas their corresponding variables
2126 might have to go on the stack. So, disregarding the decl
2127 here would negatively impact debug info at -O0, enable
2128 coalescing between SSA_NAMEs that ought to get different
2129 stack/pseudo assignments, and get the incoming argument
2130 processing thoroughly confused by PARM_DECLs expected to live
2131 in stack slots but assigned to pseudos. */
2132 if (!SSA_NAME_VAR (decl))
2133 return TYPE_MODE (TREE_TYPE (decl)) != BLKmode
2134 && !(flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)));
2136 decl = SSA_NAME_VAR (decl);
2139 /* Honor volatile. */
2140 if (TREE_SIDE_EFFECTS (decl))
2141 return false;
2143 /* Honor addressability. */
2144 if (TREE_ADDRESSABLE (decl))
2145 return false;
2147 /* RESULT_DECLs are a bit special in that they're assigned without
2148 regard to use_register_for_decl, but we generally only store in
2149 them. If we coalesce their SSA NAMEs, we'd better return a
2150 result that matches the assignment in expand_function_start. */
2151 if (TREE_CODE (decl) == RESULT_DECL)
2153 /* If it's not an aggregate, we're going to use a REG or a
2154 PARALLEL containing a REG. */
2155 if (!aggregate_value_p (decl, current_function_decl))
2156 return true;
2158 /* If expand_function_start determines the return value, we'll
2159 use MEM if it's not by reference. */
2160 if (cfun->returns_pcc_struct
2161 || (targetm.calls.struct_value_rtx
2162 (TREE_TYPE (current_function_decl), 1)))
2163 return DECL_BY_REFERENCE (decl);
2165 /* Otherwise, we're taking an extra all.function_result_decl
2166 argument. It's set up in assign_parms_augmented_arg_list,
2167 under the (negated) conditions above, and then it's used to
2168 set up the RESULT_DECL rtl in assign_params, after looping
2169 over all parameters. Now, if the RESULT_DECL is not by
2170 reference, we'll use a MEM either way. */
2171 if (!DECL_BY_REFERENCE (decl))
2172 return false;
2174 /* Otherwise, if RESULT_DECL is DECL_BY_REFERENCE, it will take
2175 the function_result_decl's assignment. Since it's a pointer,
2176 we can short-circuit a number of the tests below, and we must
2177 duplicat e them because we don't have the
2178 function_result_decl to test. */
2179 if (!targetm.calls.allocate_stack_slots_for_args ())
2180 return true;
2181 /* We don't set DECL_IGNORED_P for the function_result_decl. */
2182 if (optimize)
2183 return true;
2184 /* We don't set DECL_REGISTER for the function_result_decl. */
2185 return false;
2188 /* Decl is implicitly addressible by bound stores and loads
2189 if it is an aggregate holding bounds. */
2190 if (chkp_function_instrumented_p (current_function_decl)
2191 && TREE_TYPE (decl)
2192 && !BOUNDED_P (decl)
2193 && chkp_type_has_pointer (TREE_TYPE (decl)))
2194 return false;
2196 /* Only register-like things go in registers. */
2197 if (DECL_MODE (decl) == BLKmode)
2198 return false;
2200 /* If -ffloat-store specified, don't put explicit float variables
2201 into registers. */
2202 /* ??? This should be checked after DECL_ARTIFICIAL, but tree-ssa
2203 propagates values across these stores, and it probably shouldn't. */
2204 if (flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)))
2205 return false;
2207 if (!targetm.calls.allocate_stack_slots_for_args ())
2208 return true;
2210 /* If we're not interested in tracking debugging information for
2211 this decl, then we can certainly put it in a register. */
2212 if (DECL_IGNORED_P (decl))
2213 return true;
2215 if (optimize)
2216 return true;
2218 if (!DECL_REGISTER (decl))
2219 return false;
2221 switch (TREE_CODE (TREE_TYPE (decl)))
2223 case RECORD_TYPE:
2224 case UNION_TYPE:
2225 case QUAL_UNION_TYPE:
2226 /* When not optimizing, disregard register keyword for variables with
2227 types containing methods, otherwise the methods won't be callable
2228 from the debugger. */
2229 if (TYPE_METHODS (TYPE_MAIN_VARIANT (TREE_TYPE (decl))))
2230 return false;
2231 break;
2232 default:
2233 break;
2236 return true;
2239 /* Structures to communicate between the subroutines of assign_parms.
2240 The first holds data persistent across all parameters, the second
2241 is cleared out for each parameter. */
2243 struct assign_parm_data_all
2245 /* When INIT_CUMULATIVE_ARGS gets revamped, allocating CUMULATIVE_ARGS
2246 should become a job of the target or otherwise encapsulated. */
2247 CUMULATIVE_ARGS args_so_far_v;
2248 cumulative_args_t args_so_far;
2249 struct args_size stack_args_size;
2250 tree function_result_decl;
2251 tree orig_fnargs;
2252 rtx_insn *first_conversion_insn;
2253 rtx_insn *last_conversion_insn;
2254 HOST_WIDE_INT pretend_args_size;
2255 HOST_WIDE_INT extra_pretend_bytes;
2256 int reg_parm_stack_space;
2259 struct assign_parm_data_one
2261 tree nominal_type;
2262 tree passed_type;
2263 rtx entry_parm;
2264 rtx stack_parm;
2265 machine_mode nominal_mode;
2266 machine_mode passed_mode;
2267 machine_mode promoted_mode;
2268 struct locate_and_pad_arg_data locate;
2269 int partial;
2270 BOOL_BITFIELD named_arg : 1;
2271 BOOL_BITFIELD passed_pointer : 1;
2272 BOOL_BITFIELD on_stack : 1;
2273 BOOL_BITFIELD loaded_in_reg : 1;
2276 struct bounds_parm_data
2278 assign_parm_data_one parm_data;
2279 tree bounds_parm;
2280 tree ptr_parm;
2281 rtx ptr_entry;
2282 int bound_no;
2285 /* A subroutine of assign_parms. Initialize ALL. */
2287 static void
2288 assign_parms_initialize_all (struct assign_parm_data_all *all)
2290 tree fntype ATTRIBUTE_UNUSED;
2292 memset (all, 0, sizeof (*all));
2294 fntype = TREE_TYPE (current_function_decl);
2296 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
2297 INIT_CUMULATIVE_INCOMING_ARGS (all->args_so_far_v, fntype, NULL_RTX);
2298 #else
2299 INIT_CUMULATIVE_ARGS (all->args_so_far_v, fntype, NULL_RTX,
2300 current_function_decl, -1);
2301 #endif
2302 all->args_so_far = pack_cumulative_args (&all->args_so_far_v);
2304 #ifdef INCOMING_REG_PARM_STACK_SPACE
2305 all->reg_parm_stack_space
2306 = INCOMING_REG_PARM_STACK_SPACE (current_function_decl);
2307 #endif
2310 /* If ARGS contains entries with complex types, split the entry into two
2311 entries of the component type. Return a new list of substitutions are
2312 needed, else the old list. */
2314 static void
2315 split_complex_args (vec<tree> *args)
2317 unsigned i;
2318 tree p;
2320 FOR_EACH_VEC_ELT (*args, i, p)
2322 tree type = TREE_TYPE (p);
2323 if (TREE_CODE (type) == COMPLEX_TYPE
2324 && targetm.calls.split_complex_arg (type))
2326 tree decl;
2327 tree subtype = TREE_TYPE (type);
2328 bool addressable = TREE_ADDRESSABLE (p);
2330 /* Rewrite the PARM_DECL's type with its component. */
2331 p = copy_node (p);
2332 TREE_TYPE (p) = subtype;
2333 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
2334 SET_DECL_MODE (p, VOIDmode);
2335 DECL_SIZE (p) = NULL;
2336 DECL_SIZE_UNIT (p) = NULL;
2337 /* If this arg must go in memory, put it in a pseudo here.
2338 We can't allow it to go in memory as per normal parms,
2339 because the usual place might not have the imag part
2340 adjacent to the real part. */
2341 DECL_ARTIFICIAL (p) = addressable;
2342 DECL_IGNORED_P (p) = addressable;
2343 TREE_ADDRESSABLE (p) = 0;
2344 layout_decl (p, 0);
2345 (*args)[i] = p;
2347 /* Build a second synthetic decl. */
2348 decl = build_decl (EXPR_LOCATION (p),
2349 PARM_DECL, NULL_TREE, subtype);
2350 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
2351 DECL_ARTIFICIAL (decl) = addressable;
2352 DECL_IGNORED_P (decl) = addressable;
2353 layout_decl (decl, 0);
2354 args->safe_insert (++i, decl);
2359 /* A subroutine of assign_parms. Adjust the parameter list to incorporate
2360 the hidden struct return argument, and (abi willing) complex args.
2361 Return the new parameter list. */
2363 static vec<tree>
2364 assign_parms_augmented_arg_list (struct assign_parm_data_all *all)
2366 tree fndecl = current_function_decl;
2367 tree fntype = TREE_TYPE (fndecl);
2368 vec<tree> fnargs = vNULL;
2369 tree arg;
2371 for (arg = DECL_ARGUMENTS (fndecl); arg; arg = DECL_CHAIN (arg))
2372 fnargs.safe_push (arg);
2374 all->orig_fnargs = DECL_ARGUMENTS (fndecl);
2376 /* If struct value address is treated as the first argument, make it so. */
2377 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
2378 && ! cfun->returns_pcc_struct
2379 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
2381 tree type = build_pointer_type (TREE_TYPE (fntype));
2382 tree decl;
2384 decl = build_decl (DECL_SOURCE_LOCATION (fndecl),
2385 PARM_DECL, get_identifier (".result_ptr"), type);
2386 DECL_ARG_TYPE (decl) = type;
2387 DECL_ARTIFICIAL (decl) = 1;
2388 DECL_NAMELESS (decl) = 1;
2389 TREE_CONSTANT (decl) = 1;
2390 /* We don't set DECL_IGNORED_P or DECL_REGISTER here. If this
2391 changes, the end of the RESULT_DECL handling block in
2392 use_register_for_decl must be adjusted to match. */
2394 DECL_CHAIN (decl) = all->orig_fnargs;
2395 all->orig_fnargs = decl;
2396 fnargs.safe_insert (0, decl);
2398 all->function_result_decl = decl;
2400 /* If function is instrumented then bounds of the
2401 passed structure address is the second argument. */
2402 if (chkp_function_instrumented_p (fndecl))
2404 decl = build_decl (DECL_SOURCE_LOCATION (fndecl),
2405 PARM_DECL, get_identifier (".result_bnd"),
2406 pointer_bounds_type_node);
2407 DECL_ARG_TYPE (decl) = pointer_bounds_type_node;
2408 DECL_ARTIFICIAL (decl) = 1;
2409 DECL_NAMELESS (decl) = 1;
2410 TREE_CONSTANT (decl) = 1;
2412 DECL_CHAIN (decl) = DECL_CHAIN (all->orig_fnargs);
2413 DECL_CHAIN (all->orig_fnargs) = decl;
2414 fnargs.safe_insert (1, decl);
2418 /* If the target wants to split complex arguments into scalars, do so. */
2419 if (targetm.calls.split_complex_arg)
2420 split_complex_args (&fnargs);
2422 return fnargs;
2425 /* A subroutine of assign_parms. Examine PARM and pull out type and mode
2426 data for the parameter. Incorporate ABI specifics such as pass-by-
2427 reference and type promotion. */
2429 static void
2430 assign_parm_find_data_types (struct assign_parm_data_all *all, tree parm,
2431 struct assign_parm_data_one *data)
2433 tree nominal_type, passed_type;
2434 machine_mode nominal_mode, passed_mode, promoted_mode;
2435 int unsignedp;
2437 memset (data, 0, sizeof (*data));
2439 /* NAMED_ARG is a misnomer. We really mean 'non-variadic'. */
2440 if (!cfun->stdarg)
2441 data->named_arg = 1; /* No variadic parms. */
2442 else if (DECL_CHAIN (parm))
2443 data->named_arg = 1; /* Not the last non-variadic parm. */
2444 else if (targetm.calls.strict_argument_naming (all->args_so_far))
2445 data->named_arg = 1; /* Only variadic ones are unnamed. */
2446 else
2447 data->named_arg = 0; /* Treat as variadic. */
2449 nominal_type = TREE_TYPE (parm);
2450 passed_type = DECL_ARG_TYPE (parm);
2452 /* Look out for errors propagating this far. Also, if the parameter's
2453 type is void then its value doesn't matter. */
2454 if (TREE_TYPE (parm) == error_mark_node
2455 /* This can happen after weird syntax errors
2456 or if an enum type is defined among the parms. */
2457 || TREE_CODE (parm) != PARM_DECL
2458 || passed_type == NULL
2459 || VOID_TYPE_P (nominal_type))
2461 nominal_type = passed_type = void_type_node;
2462 nominal_mode = passed_mode = promoted_mode = VOIDmode;
2463 goto egress;
2466 /* Find mode of arg as it is passed, and mode of arg as it should be
2467 during execution of this function. */
2468 passed_mode = TYPE_MODE (passed_type);
2469 nominal_mode = TYPE_MODE (nominal_type);
2471 /* If the parm is to be passed as a transparent union or record, use the
2472 type of the first field for the tests below. We have already verified
2473 that the modes are the same. */
2474 if ((TREE_CODE (passed_type) == UNION_TYPE
2475 || TREE_CODE (passed_type) == RECORD_TYPE)
2476 && TYPE_TRANSPARENT_AGGR (passed_type))
2477 passed_type = TREE_TYPE (first_field (passed_type));
2479 /* See if this arg was passed by invisible reference. */
2480 if (pass_by_reference (&all->args_so_far_v, passed_mode,
2481 passed_type, data->named_arg))
2483 passed_type = nominal_type = build_pointer_type (passed_type);
2484 data->passed_pointer = true;
2485 passed_mode = nominal_mode = TYPE_MODE (nominal_type);
2488 /* Find mode as it is passed by the ABI. */
2489 unsignedp = TYPE_UNSIGNED (passed_type);
2490 promoted_mode = promote_function_mode (passed_type, passed_mode, &unsignedp,
2491 TREE_TYPE (current_function_decl), 0);
2493 egress:
2494 data->nominal_type = nominal_type;
2495 data->passed_type = passed_type;
2496 data->nominal_mode = nominal_mode;
2497 data->passed_mode = passed_mode;
2498 data->promoted_mode = promoted_mode;
2501 /* A subroutine of assign_parms. Invoke setup_incoming_varargs. */
2503 static void
2504 assign_parms_setup_varargs (struct assign_parm_data_all *all,
2505 struct assign_parm_data_one *data, bool no_rtl)
2507 int varargs_pretend_bytes = 0;
2509 targetm.calls.setup_incoming_varargs (all->args_so_far,
2510 data->promoted_mode,
2511 data->passed_type,
2512 &varargs_pretend_bytes, no_rtl);
2514 /* If the back-end has requested extra stack space, record how much is
2515 needed. Do not change pretend_args_size otherwise since it may be
2516 nonzero from an earlier partial argument. */
2517 if (varargs_pretend_bytes > 0)
2518 all->pretend_args_size = varargs_pretend_bytes;
2521 /* A subroutine of assign_parms. Set DATA->ENTRY_PARM corresponding to
2522 the incoming location of the current parameter. */
2524 static void
2525 assign_parm_find_entry_rtl (struct assign_parm_data_all *all,
2526 struct assign_parm_data_one *data)
2528 HOST_WIDE_INT pretend_bytes = 0;
2529 rtx entry_parm;
2530 bool in_regs;
2532 if (data->promoted_mode == VOIDmode)
2534 data->entry_parm = data->stack_parm = const0_rtx;
2535 return;
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 != 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 ? upward : 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 machine_mode mode
2989 = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
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 ? upward : 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 (TRULY_NOOP_TRUNCATION (size * BITS_PER_UNIT, BITS_PER_WORD))
3008 reg = gen_rtx_REG (mode, REGNO (entry_parm));
3009 else
3011 reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
3012 reg = convert_to_mode (mode, copy_to_reg (reg), 1);
3014 emit_move_insn (change_address (mem, mode, 0), reg);
3017 #ifdef BLOCK_REG_PADDING
3018 /* Storing the register in memory as a full word, as
3019 move_block_from_reg below would do, and then using the
3020 MEM in a smaller mode, has the effect of shifting right
3021 if BYTES_BIG_ENDIAN. If we're bypassing memory, the
3022 shifting must be explicit. */
3023 else if (!MEM_P (mem))
3025 rtx x;
3027 /* If the assert below fails, we should have taken the
3028 mode != BLKmode path above, unless we have downward
3029 padding of smaller-than-word arguments on a machine
3030 with little-endian bytes, which would likely require
3031 additional changes to work correctly. */
3032 gcc_checking_assert (BYTES_BIG_ENDIAN
3033 && (BLOCK_REG_PADDING (mode,
3034 data->passed_type, 1)
3035 == upward));
3037 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
3039 x = gen_rtx_REG (word_mode, REGNO (entry_parm));
3040 x = expand_shift (RSHIFT_EXPR, word_mode, x, by,
3041 NULL_RTX, 1);
3042 x = force_reg (word_mode, x);
3043 x = gen_lowpart_SUBREG (GET_MODE (mem), x);
3045 emit_move_insn (mem, x);
3047 #endif
3049 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
3050 machine must be aligned to the left before storing
3051 to memory. Note that the previous test doesn't
3052 handle all cases (e.g. SIZE == 3). */
3053 else if (size != UNITS_PER_WORD
3054 #ifdef BLOCK_REG_PADDING
3055 && (BLOCK_REG_PADDING (mode, data->passed_type, 1)
3056 == downward)
3057 #else
3058 && BYTES_BIG_ENDIAN
3059 #endif
3062 rtx tem, x;
3063 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
3064 rtx reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
3066 x = expand_shift (LSHIFT_EXPR, word_mode, reg, by, NULL_RTX, 1);
3067 tem = change_address (mem, word_mode, 0);
3068 emit_move_insn (tem, x);
3070 else
3071 move_block_from_reg (REGNO (entry_parm), mem,
3072 size_stored / UNITS_PER_WORD);
3074 else if (!MEM_P (mem))
3076 gcc_checking_assert (size > UNITS_PER_WORD);
3077 #ifdef BLOCK_REG_PADDING
3078 gcc_checking_assert (BLOCK_REG_PADDING (GET_MODE (mem),
3079 data->passed_type, 0)
3080 == upward);
3081 #endif
3082 emit_move_insn (mem, entry_parm);
3084 else
3085 move_block_from_reg (REGNO (entry_parm), mem,
3086 size_stored / UNITS_PER_WORD);
3088 else if (data->stack_parm == 0)
3090 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3091 emit_block_move (stack_parm, data->entry_parm, GEN_INT (size),
3092 BLOCK_OP_NORMAL);
3093 all->first_conversion_insn = get_insns ();
3094 all->last_conversion_insn = get_last_insn ();
3095 end_sequence ();
3096 in_conversion_seq = true;
3099 if (target_reg)
3101 if (!in_conversion_seq)
3102 emit_move_insn (target_reg, stack_parm);
3103 else
3105 push_to_sequence2 (all->first_conversion_insn,
3106 all->last_conversion_insn);
3107 emit_move_insn (target_reg, stack_parm);
3108 all->first_conversion_insn = get_insns ();
3109 all->last_conversion_insn = get_last_insn ();
3110 end_sequence ();
3112 stack_parm = target_reg;
3115 data->stack_parm = stack_parm;
3116 set_parm_rtl (parm, stack_parm);
3119 /* A subroutine of assign_parms. Allocate a pseudo to hold the current
3120 parameter. Get it there. Perform all ABI specified conversions. */
3122 static void
3123 assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm,
3124 struct assign_parm_data_one *data)
3126 rtx parmreg, validated_mem;
3127 rtx equiv_stack_parm;
3128 machine_mode promoted_nominal_mode;
3129 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (parm));
3130 bool did_conversion = false;
3131 bool need_conversion, moved;
3132 rtx rtl;
3134 /* Store the parm in a pseudoregister during the function, but we may
3135 need to do it in a wider mode. Using 2 here makes the result
3136 consistent with promote_decl_mode and thus expand_expr_real_1. */
3137 promoted_nominal_mode
3138 = promote_function_mode (data->nominal_type, data->nominal_mode, &unsignedp,
3139 TREE_TYPE (current_function_decl), 2);
3141 parmreg = gen_reg_rtx (promoted_nominal_mode);
3142 if (!DECL_ARTIFICIAL (parm))
3143 mark_user_reg (parmreg);
3145 /* If this was an item that we received a pointer to,
3146 set rtl appropriately. */
3147 if (data->passed_pointer)
3149 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data->passed_type)), parmreg);
3150 set_mem_attributes (rtl, parm, 1);
3152 else
3153 rtl = parmreg;
3155 assign_parm_remove_parallels (data);
3157 /* Copy the value into the register, thus bridging between
3158 assign_parm_find_data_types and expand_expr_real_1. */
3160 equiv_stack_parm = data->stack_parm;
3161 validated_mem = validize_mem (copy_rtx (data->entry_parm));
3163 need_conversion = (data->nominal_mode != data->passed_mode
3164 || promoted_nominal_mode != data->promoted_mode);
3165 moved = false;
3167 if (need_conversion
3168 && GET_MODE_CLASS (data->nominal_mode) == MODE_INT
3169 && data->nominal_mode == data->passed_mode
3170 && data->nominal_mode == GET_MODE (data->entry_parm))
3172 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
3173 mode, by the caller. We now have to convert it to
3174 NOMINAL_MODE, if different. However, PARMREG may be in
3175 a different mode than NOMINAL_MODE if it is being stored
3176 promoted.
3178 If ENTRY_PARM is a hard register, it might be in a register
3179 not valid for operating in its mode (e.g., an odd-numbered
3180 register for a DFmode). In that case, moves are the only
3181 thing valid, so we can't do a convert from there. This
3182 occurs when the calling sequence allow such misaligned
3183 usages.
3185 In addition, the conversion may involve a call, which could
3186 clobber parameters which haven't been copied to pseudo
3187 registers yet.
3189 First, we try to emit an insn which performs the necessary
3190 conversion. We verify that this insn does not clobber any
3191 hard registers. */
3193 enum insn_code icode;
3194 rtx op0, op1;
3196 icode = can_extend_p (promoted_nominal_mode, data->passed_mode,
3197 unsignedp);
3199 op0 = parmreg;
3200 op1 = validated_mem;
3201 if (icode != CODE_FOR_nothing
3202 && insn_operand_matches (icode, 0, op0)
3203 && insn_operand_matches (icode, 1, op1))
3205 enum rtx_code code = unsignedp ? ZERO_EXTEND : SIGN_EXTEND;
3206 rtx_insn *insn, *insns;
3207 rtx t = op1;
3208 HARD_REG_SET hardregs;
3210 start_sequence ();
3211 /* If op1 is a hard register that is likely spilled, first
3212 force it into a pseudo, otherwise combiner might extend
3213 its lifetime too much. */
3214 if (GET_CODE (t) == SUBREG)
3215 t = SUBREG_REG (t);
3216 if (REG_P (t)
3217 && HARD_REGISTER_P (t)
3218 && ! TEST_HARD_REG_BIT (fixed_reg_set, REGNO (t))
3219 && targetm.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (t))))
3221 t = gen_reg_rtx (GET_MODE (op1));
3222 emit_move_insn (t, op1);
3224 else
3225 t = op1;
3226 rtx_insn *pat = gen_extend_insn (op0, t, promoted_nominal_mode,
3227 data->passed_mode, unsignedp);
3228 emit_insn (pat);
3229 insns = get_insns ();
3231 moved = true;
3232 CLEAR_HARD_REG_SET (hardregs);
3233 for (insn = insns; insn && moved; insn = NEXT_INSN (insn))
3235 if (INSN_P (insn))
3236 note_stores (PATTERN (insn), record_hard_reg_sets,
3237 &hardregs);
3238 if (!hard_reg_set_empty_p (hardregs))
3239 moved = false;
3242 end_sequence ();
3244 if (moved)
3246 emit_insn (insns);
3247 if (equiv_stack_parm != NULL_RTX)
3248 equiv_stack_parm = gen_rtx_fmt_e (code, GET_MODE (parmreg),
3249 equiv_stack_parm);
3254 if (moved)
3255 /* Nothing to do. */
3257 else if (need_conversion)
3259 /* We did not have an insn to convert directly, or the sequence
3260 generated appeared unsafe. We must first copy the parm to a
3261 pseudo reg, and save the conversion until after all
3262 parameters have been moved. */
3264 int save_tree_used;
3265 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
3267 emit_move_insn (tempreg, validated_mem);
3269 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3270 tempreg = convert_to_mode (data->nominal_mode, tempreg, unsignedp);
3272 if (GET_CODE (tempreg) == SUBREG
3273 && GET_MODE (tempreg) == data->nominal_mode
3274 && REG_P (SUBREG_REG (tempreg))
3275 && data->nominal_mode == data->passed_mode
3276 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (data->entry_parm)
3277 && GET_MODE_SIZE (GET_MODE (tempreg))
3278 < GET_MODE_SIZE (GET_MODE (data->entry_parm)))
3280 /* The argument is already sign/zero extended, so note it
3281 into the subreg. */
3282 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
3283 SUBREG_PROMOTED_SET (tempreg, unsignedp);
3286 /* TREE_USED gets set erroneously during expand_assignment. */
3287 save_tree_used = TREE_USED (parm);
3288 SET_DECL_RTL (parm, rtl);
3289 expand_assignment (parm, make_tree (data->nominal_type, tempreg), false);
3290 SET_DECL_RTL (parm, NULL_RTX);
3291 TREE_USED (parm) = save_tree_used;
3292 all->first_conversion_insn = get_insns ();
3293 all->last_conversion_insn = get_last_insn ();
3294 end_sequence ();
3296 did_conversion = true;
3298 else
3299 emit_move_insn (parmreg, validated_mem);
3301 /* If we were passed a pointer but the actual value can safely live
3302 in a register, retrieve it and use it directly. */
3303 if (data->passed_pointer && TYPE_MODE (TREE_TYPE (parm)) != BLKmode)
3305 /* We can't use nominal_mode, because it will have been set to
3306 Pmode above. We must use the actual mode of the parm. */
3307 if (use_register_for_decl (parm))
3309 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
3310 mark_user_reg (parmreg);
3312 else
3314 int align = STACK_SLOT_ALIGNMENT (TREE_TYPE (parm),
3315 TYPE_MODE (TREE_TYPE (parm)),
3316 TYPE_ALIGN (TREE_TYPE (parm)));
3317 parmreg
3318 = assign_stack_local (TYPE_MODE (TREE_TYPE (parm)),
3319 GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (parm))),
3320 align);
3321 set_mem_attributes (parmreg, parm, 1);
3324 /* We need to preserve an address based on VIRTUAL_STACK_VARS_REGNUM for
3325 the debug info in case it is not legitimate. */
3326 if (GET_MODE (parmreg) != GET_MODE (rtl))
3328 rtx tempreg = gen_reg_rtx (GET_MODE (rtl));
3329 int unsigned_p = TYPE_UNSIGNED (TREE_TYPE (parm));
3331 push_to_sequence2 (all->first_conversion_insn,
3332 all->last_conversion_insn);
3333 emit_move_insn (tempreg, rtl);
3334 tempreg = convert_to_mode (GET_MODE (parmreg), tempreg, unsigned_p);
3335 emit_move_insn (MEM_P (parmreg) ? copy_rtx (parmreg) : parmreg,
3336 tempreg);
3337 all->first_conversion_insn = get_insns ();
3338 all->last_conversion_insn = get_last_insn ();
3339 end_sequence ();
3341 did_conversion = true;
3343 else
3344 emit_move_insn (MEM_P (parmreg) ? copy_rtx (parmreg) : parmreg, rtl);
3346 rtl = parmreg;
3348 /* STACK_PARM is the pointer, not the parm, and PARMREG is
3349 now the parm. */
3350 data->stack_parm = NULL;
3353 set_parm_rtl (parm, rtl);
3355 /* Mark the register as eliminable if we did no conversion and it was
3356 copied from memory at a fixed offset, and the arg pointer was not
3357 copied to a pseudo-reg. If the arg pointer is a pseudo reg or the
3358 offset formed an invalid address, such memory-equivalences as we
3359 make here would screw up life analysis for it. */
3360 if (data->nominal_mode == data->passed_mode
3361 && !did_conversion
3362 && data->stack_parm != 0
3363 && MEM_P (data->stack_parm)
3364 && data->locate.offset.var == 0
3365 && reg_mentioned_p (virtual_incoming_args_rtx,
3366 XEXP (data->stack_parm, 0)))
3368 rtx_insn *linsn = get_last_insn ();
3369 rtx_insn *sinsn;
3370 rtx set;
3372 /* Mark complex types separately. */
3373 if (GET_CODE (parmreg) == CONCAT)
3375 machine_mode submode
3376 = GET_MODE_INNER (GET_MODE (parmreg));
3377 int regnor = REGNO (XEXP (parmreg, 0));
3378 int regnoi = REGNO (XEXP (parmreg, 1));
3379 rtx stackr = adjust_address_nv (data->stack_parm, submode, 0);
3380 rtx stacki = adjust_address_nv (data->stack_parm, submode,
3381 GET_MODE_SIZE (submode));
3383 /* Scan backwards for the set of the real and
3384 imaginary parts. */
3385 for (sinsn = linsn; sinsn != 0;
3386 sinsn = prev_nonnote_insn (sinsn))
3388 set = single_set (sinsn);
3389 if (set == 0)
3390 continue;
3392 if (SET_DEST (set) == regno_reg_rtx [regnoi])
3393 set_unique_reg_note (sinsn, REG_EQUIV, stacki);
3394 else if (SET_DEST (set) == regno_reg_rtx [regnor])
3395 set_unique_reg_note (sinsn, REG_EQUIV, stackr);
3398 else
3399 set_dst_reg_note (linsn, REG_EQUIV, equiv_stack_parm, parmreg);
3402 /* For pointer data type, suggest pointer register. */
3403 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3404 mark_reg_pointer (parmreg,
3405 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
3408 /* A subroutine of assign_parms. Allocate stack space to hold the current
3409 parameter. Get it there. Perform all ABI specified conversions. */
3411 static void
3412 assign_parm_setup_stack (struct assign_parm_data_all *all, tree parm,
3413 struct assign_parm_data_one *data)
3415 /* Value must be stored in the stack slot STACK_PARM during function
3416 execution. */
3417 bool to_conversion = false;
3419 assign_parm_remove_parallels (data);
3421 if (data->promoted_mode != data->nominal_mode)
3423 /* Conversion is required. */
3424 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
3426 emit_move_insn (tempreg, validize_mem (copy_rtx (data->entry_parm)));
3428 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3429 to_conversion = true;
3431 data->entry_parm = convert_to_mode (data->nominal_mode, tempreg,
3432 TYPE_UNSIGNED (TREE_TYPE (parm)));
3434 if (data->stack_parm)
3436 int offset = subreg_lowpart_offset (data->nominal_mode,
3437 GET_MODE (data->stack_parm));
3438 /* ??? This may need a big-endian conversion on sparc64. */
3439 data->stack_parm
3440 = adjust_address (data->stack_parm, data->nominal_mode, 0);
3441 if (offset && MEM_OFFSET_KNOWN_P (data->stack_parm))
3442 set_mem_offset (data->stack_parm,
3443 MEM_OFFSET (data->stack_parm) + offset);
3447 if (data->entry_parm != data->stack_parm)
3449 rtx src, dest;
3451 if (data->stack_parm == 0)
3453 int align = STACK_SLOT_ALIGNMENT (data->passed_type,
3454 GET_MODE (data->entry_parm),
3455 TYPE_ALIGN (data->passed_type));
3456 data->stack_parm
3457 = assign_stack_local (GET_MODE (data->entry_parm),
3458 GET_MODE_SIZE (GET_MODE (data->entry_parm)),
3459 align);
3460 set_mem_attributes (data->stack_parm, parm, 1);
3463 dest = validize_mem (copy_rtx (data->stack_parm));
3464 src = validize_mem (copy_rtx (data->entry_parm));
3466 if (MEM_P (src))
3468 /* Use a block move to handle potentially misaligned entry_parm. */
3469 if (!to_conversion)
3470 push_to_sequence2 (all->first_conversion_insn,
3471 all->last_conversion_insn);
3472 to_conversion = true;
3474 emit_block_move (dest, src,
3475 GEN_INT (int_size_in_bytes (data->passed_type)),
3476 BLOCK_OP_NORMAL);
3478 else
3480 if (!REG_P (src))
3481 src = force_reg (GET_MODE (src), src);
3482 emit_move_insn (dest, src);
3486 if (to_conversion)
3488 all->first_conversion_insn = get_insns ();
3489 all->last_conversion_insn = get_last_insn ();
3490 end_sequence ();
3493 set_parm_rtl (parm, data->stack_parm);
3496 /* A subroutine of assign_parms. If the ABI splits complex arguments, then
3497 undo the frobbing that we did in assign_parms_augmented_arg_list. */
3499 static void
3500 assign_parms_unsplit_complex (struct assign_parm_data_all *all,
3501 vec<tree> fnargs)
3503 tree parm;
3504 tree orig_fnargs = all->orig_fnargs;
3505 unsigned i = 0;
3507 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm), ++i)
3509 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
3510 && targetm.calls.split_complex_arg (TREE_TYPE (parm)))
3512 rtx tmp, real, imag;
3513 machine_mode inner = GET_MODE_INNER (DECL_MODE (parm));
3515 real = DECL_RTL (fnargs[i]);
3516 imag = DECL_RTL (fnargs[i + 1]);
3517 if (inner != GET_MODE (real))
3519 real = gen_lowpart_SUBREG (inner, real);
3520 imag = gen_lowpart_SUBREG (inner, imag);
3523 if (TREE_ADDRESSABLE (parm))
3525 rtx rmem, imem;
3526 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (parm));
3527 int align = STACK_SLOT_ALIGNMENT (TREE_TYPE (parm),
3528 DECL_MODE (parm),
3529 TYPE_ALIGN (TREE_TYPE (parm)));
3531 /* split_complex_arg put the real and imag parts in
3532 pseudos. Move them to memory. */
3533 tmp = assign_stack_local (DECL_MODE (parm), size, align);
3534 set_mem_attributes (tmp, parm, 1);
3535 rmem = adjust_address_nv (tmp, inner, 0);
3536 imem = adjust_address_nv (tmp, inner, GET_MODE_SIZE (inner));
3537 push_to_sequence2 (all->first_conversion_insn,
3538 all->last_conversion_insn);
3539 emit_move_insn (rmem, real);
3540 emit_move_insn (imem, imag);
3541 all->first_conversion_insn = get_insns ();
3542 all->last_conversion_insn = get_last_insn ();
3543 end_sequence ();
3545 else
3546 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
3547 set_parm_rtl (parm, tmp);
3549 real = DECL_INCOMING_RTL (fnargs[i]);
3550 imag = DECL_INCOMING_RTL (fnargs[i + 1]);
3551 if (inner != GET_MODE (real))
3553 real = gen_lowpart_SUBREG (inner, real);
3554 imag = gen_lowpart_SUBREG (inner, imag);
3556 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
3557 set_decl_incoming_rtl (parm, tmp, false);
3558 i++;
3563 /* Load bounds of PARM from bounds table. */
3564 static void
3565 assign_parm_load_bounds (struct assign_parm_data_one *data,
3566 tree parm,
3567 rtx entry,
3568 unsigned bound_no)
3570 bitmap_iterator bi;
3571 unsigned i, offs = 0;
3572 int bnd_no = -1;
3573 rtx slot = NULL, ptr = NULL;
3575 if (parm)
3577 bitmap slots;
3578 bitmap_obstack_initialize (NULL);
3579 slots = BITMAP_ALLOC (NULL);
3580 chkp_find_bound_slots (TREE_TYPE (parm), slots);
3581 EXECUTE_IF_SET_IN_BITMAP (slots, 0, i, bi)
3583 if (bound_no)
3584 bound_no--;
3585 else
3587 bnd_no = i;
3588 break;
3591 BITMAP_FREE (slots);
3592 bitmap_obstack_release (NULL);
3595 /* We may have bounds not associated with any pointer. */
3596 if (bnd_no != -1)
3597 offs = bnd_no * POINTER_SIZE / BITS_PER_UNIT;
3599 /* Find associated pointer. */
3600 if (bnd_no == -1)
3602 /* If bounds are not associated with any bounds,
3603 then it is passed in a register or special slot. */
3604 gcc_assert (data->entry_parm);
3605 ptr = const0_rtx;
3607 else if (MEM_P (entry))
3608 slot = adjust_address (entry, Pmode, offs);
3609 else if (REG_P (entry))
3610 ptr = gen_rtx_REG (Pmode, REGNO (entry) + bnd_no);
3611 else if (GET_CODE (entry) == PARALLEL)
3612 ptr = chkp_get_value_with_offs (entry, GEN_INT (offs));
3613 else
3614 gcc_unreachable ();
3615 data->entry_parm = targetm.calls.load_bounds_for_arg (slot, ptr,
3616 data->entry_parm);
3619 /* Assign RTL expressions to the function's bounds parameters BNDARGS. */
3621 static void
3622 assign_bounds (vec<bounds_parm_data> &bndargs,
3623 struct assign_parm_data_all &all,
3624 bool assign_regs, bool assign_special,
3625 bool assign_bt)
3627 unsigned i, pass;
3628 bounds_parm_data *pbdata;
3630 if (!bndargs.exists ())
3631 return;
3633 /* We make few passes to store input bounds. Firstly handle bounds
3634 passed in registers. After that we load bounds passed in special
3635 slots. Finally we load bounds from Bounds Table. */
3636 for (pass = 0; pass < 3; pass++)
3637 FOR_EACH_VEC_ELT (bndargs, i, pbdata)
3639 /* Pass 0 => regs only. */
3640 if (pass == 0
3641 && (!assign_regs
3642 ||(!pbdata->parm_data.entry_parm
3643 || GET_CODE (pbdata->parm_data.entry_parm) != REG)))
3644 continue;
3645 /* Pass 1 => slots only. */
3646 else if (pass == 1
3647 && (!assign_special
3648 || (!pbdata->parm_data.entry_parm
3649 || GET_CODE (pbdata->parm_data.entry_parm) == REG)))
3650 continue;
3651 /* Pass 2 => BT only. */
3652 else if (pass == 2
3653 && (!assign_bt
3654 || pbdata->parm_data.entry_parm))
3655 continue;
3657 if (!pbdata->parm_data.entry_parm
3658 || GET_CODE (pbdata->parm_data.entry_parm) != REG)
3659 assign_parm_load_bounds (&pbdata->parm_data, pbdata->ptr_parm,
3660 pbdata->ptr_entry, pbdata->bound_no);
3662 set_decl_incoming_rtl (pbdata->bounds_parm,
3663 pbdata->parm_data.entry_parm, false);
3665 if (assign_parm_setup_block_p (&pbdata->parm_data))
3666 assign_parm_setup_block (&all, pbdata->bounds_parm,
3667 &pbdata->parm_data);
3668 else if (pbdata->parm_data.passed_pointer
3669 || use_register_for_decl (pbdata->bounds_parm))
3670 assign_parm_setup_reg (&all, pbdata->bounds_parm,
3671 &pbdata->parm_data);
3672 else
3673 assign_parm_setup_stack (&all, pbdata->bounds_parm,
3674 &pbdata->parm_data);
3678 /* Assign RTL expressions to the function's parameters. This may involve
3679 copying them into registers and using those registers as the DECL_RTL. */
3681 static void
3682 assign_parms (tree fndecl)
3684 struct assign_parm_data_all all;
3685 tree parm;
3686 vec<tree> fnargs;
3687 unsigned i, bound_no = 0;
3688 tree last_arg = NULL;
3689 rtx last_arg_entry = NULL;
3690 vec<bounds_parm_data> bndargs = vNULL;
3691 bounds_parm_data bdata;
3693 crtl->args.internal_arg_pointer
3694 = targetm.calls.internal_arg_pointer ();
3696 assign_parms_initialize_all (&all);
3697 fnargs = assign_parms_augmented_arg_list (&all);
3699 FOR_EACH_VEC_ELT (fnargs, i, parm)
3701 struct assign_parm_data_one data;
3703 /* Extract the type of PARM; adjust it according to ABI. */
3704 assign_parm_find_data_types (&all, parm, &data);
3706 /* Early out for errors and void parameters. */
3707 if (data.passed_mode == VOIDmode)
3709 SET_DECL_RTL (parm, const0_rtx);
3710 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
3711 continue;
3714 /* Estimate stack alignment from parameter alignment. */
3715 if (SUPPORTS_STACK_ALIGNMENT)
3717 unsigned int align
3718 = targetm.calls.function_arg_boundary (data.promoted_mode,
3719 data.passed_type);
3720 align = MINIMUM_ALIGNMENT (data.passed_type, data.promoted_mode,
3721 align);
3722 if (TYPE_ALIGN (data.nominal_type) > align)
3723 align = MINIMUM_ALIGNMENT (data.nominal_type,
3724 TYPE_MODE (data.nominal_type),
3725 TYPE_ALIGN (data.nominal_type));
3726 if (crtl->stack_alignment_estimated < align)
3728 gcc_assert (!crtl->stack_realign_processed);
3729 crtl->stack_alignment_estimated = align;
3733 /* Find out where the parameter arrives in this function. */
3734 assign_parm_find_entry_rtl (&all, &data);
3736 /* Find out where stack space for this parameter might be. */
3737 if (assign_parm_is_stack_parm (&all, &data))
3739 assign_parm_find_stack_rtl (parm, &data);
3740 assign_parm_adjust_entry_rtl (&data);
3742 if (!POINTER_BOUNDS_TYPE_P (data.passed_type))
3744 /* Remember where last non bounds arg was passed in case
3745 we have to load associated bounds for it from Bounds
3746 Table. */
3747 last_arg = parm;
3748 last_arg_entry = data.entry_parm;
3749 bound_no = 0;
3751 /* Record permanently how this parm was passed. */
3752 if (data.passed_pointer)
3754 rtx incoming_rtl
3755 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data.passed_type)),
3756 data.entry_parm);
3757 set_decl_incoming_rtl (parm, incoming_rtl, true);
3759 else
3760 set_decl_incoming_rtl (parm, data.entry_parm, false);
3762 assign_parm_adjust_stack_rtl (&data);
3764 /* Bounds should be loaded in the particular order to
3765 have registers allocated correctly. Collect info about
3766 input bounds and load them later. */
3767 if (POINTER_BOUNDS_TYPE_P (data.passed_type))
3769 /* Expect bounds in instrumented functions only. */
3770 gcc_assert (chkp_function_instrumented_p (fndecl));
3772 bdata.parm_data = data;
3773 bdata.bounds_parm = parm;
3774 bdata.ptr_parm = last_arg;
3775 bdata.ptr_entry = last_arg_entry;
3776 bdata.bound_no = bound_no;
3777 bndargs.safe_push (bdata);
3779 else
3781 if (assign_parm_setup_block_p (&data))
3782 assign_parm_setup_block (&all, parm, &data);
3783 else if (data.passed_pointer || use_register_for_decl (parm))
3784 assign_parm_setup_reg (&all, parm, &data);
3785 else
3786 assign_parm_setup_stack (&all, parm, &data);
3789 if (cfun->stdarg && !DECL_CHAIN (parm))
3791 int pretend_bytes = 0;
3793 assign_parms_setup_varargs (&all, &data, false);
3795 if (chkp_function_instrumented_p (fndecl))
3797 /* We expect this is the last parm. Otherwise it is wrong
3798 to assign bounds right now. */
3799 gcc_assert (i == (fnargs.length () - 1));
3800 assign_bounds (bndargs, all, true, false, false);
3801 targetm.calls.setup_incoming_vararg_bounds (all.args_so_far,
3802 data.promoted_mode,
3803 data.passed_type,
3804 &pretend_bytes,
3805 false);
3806 assign_bounds (bndargs, all, false, true, true);
3807 bndargs.release ();
3811 /* Update info on where next arg arrives in registers. */
3812 targetm.calls.function_arg_advance (all.args_so_far, data.promoted_mode,
3813 data.passed_type, data.named_arg);
3815 if (POINTER_BOUNDS_TYPE_P (data.passed_type))
3816 bound_no++;
3819 assign_bounds (bndargs, all, true, true, true);
3820 bndargs.release ();
3822 if (targetm.calls.split_complex_arg)
3823 assign_parms_unsplit_complex (&all, fnargs);
3825 fnargs.release ();
3827 /* Output all parameter conversion instructions (possibly including calls)
3828 now that all parameters have been copied out of hard registers. */
3829 emit_insn (all.first_conversion_insn);
3831 /* Estimate reload stack alignment from scalar return mode. */
3832 if (SUPPORTS_STACK_ALIGNMENT)
3834 if (DECL_RESULT (fndecl))
3836 tree type = TREE_TYPE (DECL_RESULT (fndecl));
3837 machine_mode mode = TYPE_MODE (type);
3839 if (mode != BLKmode
3840 && mode != VOIDmode
3841 && !AGGREGATE_TYPE_P (type))
3843 unsigned int align = GET_MODE_ALIGNMENT (mode);
3844 if (crtl->stack_alignment_estimated < align)
3846 gcc_assert (!crtl->stack_realign_processed);
3847 crtl->stack_alignment_estimated = align;
3853 /* If we are receiving a struct value address as the first argument, set up
3854 the RTL for the function result. As this might require code to convert
3855 the transmitted address to Pmode, we do this here to ensure that possible
3856 preliminary conversions of the address have been emitted already. */
3857 if (all.function_result_decl)
3859 tree result = DECL_RESULT (current_function_decl);
3860 rtx addr = DECL_RTL (all.function_result_decl);
3861 rtx x;
3863 if (DECL_BY_REFERENCE (result))
3865 SET_DECL_VALUE_EXPR (result, all.function_result_decl);
3866 x = addr;
3868 else
3870 SET_DECL_VALUE_EXPR (result,
3871 build1 (INDIRECT_REF, TREE_TYPE (result),
3872 all.function_result_decl));
3873 addr = convert_memory_address (Pmode, addr);
3874 x = gen_rtx_MEM (DECL_MODE (result), addr);
3875 set_mem_attributes (x, result, 1);
3878 DECL_HAS_VALUE_EXPR_P (result) = 1;
3880 set_parm_rtl (result, x);
3883 /* We have aligned all the args, so add space for the pretend args. */
3884 crtl->args.pretend_args_size = all.pretend_args_size;
3885 all.stack_args_size.constant += all.extra_pretend_bytes;
3886 crtl->args.size = all.stack_args_size.constant;
3888 /* Adjust function incoming argument size for alignment and
3889 minimum length. */
3891 crtl->args.size = MAX (crtl->args.size, all.reg_parm_stack_space);
3892 crtl->args.size = CEIL_ROUND (crtl->args.size,
3893 PARM_BOUNDARY / BITS_PER_UNIT);
3895 if (ARGS_GROW_DOWNWARD)
3897 crtl->args.arg_offset_rtx
3898 = (all.stack_args_size.var == 0 ? GEN_INT (-all.stack_args_size.constant)
3899 : expand_expr (size_diffop (all.stack_args_size.var,
3900 size_int (-all.stack_args_size.constant)),
3901 NULL_RTX, VOIDmode, EXPAND_NORMAL));
3903 else
3904 crtl->args.arg_offset_rtx = ARGS_SIZE_RTX (all.stack_args_size);
3906 /* See how many bytes, if any, of its args a function should try to pop
3907 on return. */
3909 crtl->args.pops_args = targetm.calls.return_pops_args (fndecl,
3910 TREE_TYPE (fndecl),
3911 crtl->args.size);
3913 /* For stdarg.h function, save info about
3914 regs and stack space used by the named args. */
3916 crtl->args.info = all.args_so_far_v;
3918 /* Set the rtx used for the function return value. Put this in its
3919 own variable so any optimizers that need this information don't have
3920 to include tree.h. Do this here so it gets done when an inlined
3921 function gets output. */
3923 crtl->return_rtx
3924 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
3925 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
3927 /* If scalar return value was computed in a pseudo-reg, or was a named
3928 return value that got dumped to the stack, copy that to the hard
3929 return register. */
3930 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
3932 tree decl_result = DECL_RESULT (fndecl);
3933 rtx decl_rtl = DECL_RTL (decl_result);
3935 if (REG_P (decl_rtl)
3936 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
3937 : DECL_REGISTER (decl_result))
3939 rtx real_decl_rtl;
3941 real_decl_rtl = targetm.calls.function_value (TREE_TYPE (decl_result),
3942 fndecl, true);
3943 if (chkp_function_instrumented_p (fndecl))
3944 crtl->return_bnd
3945 = targetm.calls.chkp_function_value_bounds (TREE_TYPE (decl_result),
3946 fndecl, true);
3947 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
3948 /* The delay slot scheduler assumes that crtl->return_rtx
3949 holds the hard register containing the return value, not a
3950 temporary pseudo. */
3951 crtl->return_rtx = real_decl_rtl;
3956 /* A subroutine of gimplify_parameters, invoked via walk_tree.
3957 For all seen types, gimplify their sizes. */
3959 static tree
3960 gimplify_parm_type (tree *tp, int *walk_subtrees, void *data)
3962 tree t = *tp;
3964 *walk_subtrees = 0;
3965 if (TYPE_P (t))
3967 if (POINTER_TYPE_P (t))
3968 *walk_subtrees = 1;
3969 else if (TYPE_SIZE (t) && !TREE_CONSTANT (TYPE_SIZE (t))
3970 && !TYPE_SIZES_GIMPLIFIED (t))
3972 gimplify_type_sizes (t, (gimple_seq *) data);
3973 *walk_subtrees = 1;
3977 return NULL;
3980 /* Gimplify the parameter list for current_function_decl. This involves
3981 evaluating SAVE_EXPRs of variable sized parameters and generating code
3982 to implement callee-copies reference parameters. Returns a sequence of
3983 statements to add to the beginning of the function. */
3985 gimple_seq
3986 gimplify_parameters (void)
3988 struct assign_parm_data_all all;
3989 tree parm;
3990 gimple_seq stmts = NULL;
3991 vec<tree> fnargs;
3992 unsigned i;
3994 assign_parms_initialize_all (&all);
3995 fnargs = assign_parms_augmented_arg_list (&all);
3997 FOR_EACH_VEC_ELT (fnargs, i, parm)
3999 struct assign_parm_data_one data;
4001 /* Extract the type of PARM; adjust it according to ABI. */
4002 assign_parm_find_data_types (&all, parm, &data);
4004 /* Early out for errors and void parameters. */
4005 if (data.passed_mode == VOIDmode || DECL_SIZE (parm) == NULL)
4006 continue;
4008 /* Update info on where next arg arrives in registers. */
4009 targetm.calls.function_arg_advance (all.args_so_far, data.promoted_mode,
4010 data.passed_type, data.named_arg);
4012 /* ??? Once upon a time variable_size stuffed parameter list
4013 SAVE_EXPRs (amongst others) onto a pending sizes list. This
4014 turned out to be less than manageable in the gimple world.
4015 Now we have to hunt them down ourselves. */
4016 walk_tree_without_duplicates (&data.passed_type,
4017 gimplify_parm_type, &stmts);
4019 if (TREE_CODE (DECL_SIZE_UNIT (parm)) != INTEGER_CST)
4021 gimplify_one_sizepos (&DECL_SIZE (parm), &stmts);
4022 gimplify_one_sizepos (&DECL_SIZE_UNIT (parm), &stmts);
4025 if (data.passed_pointer)
4027 tree type = TREE_TYPE (data.passed_type);
4028 if (reference_callee_copied (&all.args_so_far_v, TYPE_MODE (type),
4029 type, data.named_arg))
4031 tree local, t;
4033 /* For constant-sized objects, this is trivial; for
4034 variable-sized objects, we have to play games. */
4035 if (TREE_CODE (DECL_SIZE_UNIT (parm)) == INTEGER_CST
4036 && !(flag_stack_check == GENERIC_STACK_CHECK
4037 && compare_tree_int (DECL_SIZE_UNIT (parm),
4038 STACK_CHECK_MAX_VAR_SIZE) > 0))
4040 local = create_tmp_var (type, get_name (parm));
4041 DECL_IGNORED_P (local) = 0;
4042 /* If PARM was addressable, move that flag over
4043 to the local copy, as its address will be taken,
4044 not the PARMs. Keep the parms address taken
4045 as we'll query that flag during gimplification. */
4046 if (TREE_ADDRESSABLE (parm))
4047 TREE_ADDRESSABLE (local) = 1;
4048 else if (TREE_CODE (type) == COMPLEX_TYPE
4049 || TREE_CODE (type) == VECTOR_TYPE)
4050 DECL_GIMPLE_REG_P (local) = 1;
4052 else
4054 tree ptr_type, addr;
4056 ptr_type = build_pointer_type (type);
4057 addr = create_tmp_reg (ptr_type, get_name (parm));
4058 DECL_IGNORED_P (addr) = 0;
4059 local = build_fold_indirect_ref (addr);
4061 t = builtin_decl_explicit (BUILT_IN_ALLOCA_WITH_ALIGN);
4062 t = build_call_expr (t, 2, DECL_SIZE_UNIT (parm),
4063 size_int (DECL_ALIGN (parm)));
4065 /* The call has been built for a variable-sized object. */
4066 CALL_ALLOCA_FOR_VAR_P (t) = 1;
4067 t = fold_convert (ptr_type, t);
4068 t = build2 (MODIFY_EXPR, TREE_TYPE (addr), addr, t);
4069 gimplify_and_add (t, &stmts);
4072 gimplify_assign (local, parm, &stmts);
4074 SET_DECL_VALUE_EXPR (parm, local);
4075 DECL_HAS_VALUE_EXPR_P (parm) = 1;
4080 fnargs.release ();
4082 return stmts;
4085 /* Compute the size and offset from the start of the stacked arguments for a
4086 parm passed in mode PASSED_MODE and with type TYPE.
4088 INITIAL_OFFSET_PTR points to the current offset into the stacked
4089 arguments.
4091 The starting offset and size for this parm are returned in
4092 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
4093 nonzero, the offset is that of stack slot, which is returned in
4094 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
4095 padding required from the initial offset ptr to the stack slot.
4097 IN_REGS is nonzero if the argument will be passed in registers. It will
4098 never be set if REG_PARM_STACK_SPACE is not defined.
4100 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
4101 for arguments which are passed in registers.
4103 FNDECL is the function in which the argument was defined.
4105 There are two types of rounding that are done. The first, controlled by
4106 TARGET_FUNCTION_ARG_BOUNDARY, forces the offset from the start of the
4107 argument list to be aligned to the specific boundary (in bits). This
4108 rounding affects the initial and starting offsets, but not the argument
4109 size.
4111 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
4112 optionally rounds the size of the parm to PARM_BOUNDARY. The
4113 initial offset is not affected by this rounding, while the size always
4114 is and the starting offset may be. */
4116 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
4117 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
4118 callers pass in the total size of args so far as
4119 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
4121 void
4122 locate_and_pad_parm (machine_mode passed_mode, tree type, int in_regs,
4123 int reg_parm_stack_space, int partial,
4124 tree fndecl ATTRIBUTE_UNUSED,
4125 struct args_size *initial_offset_ptr,
4126 struct locate_and_pad_arg_data *locate)
4128 tree sizetree;
4129 enum direction where_pad;
4130 unsigned int boundary, round_boundary;
4131 int part_size_in_regs;
4133 /* If we have found a stack parm before we reach the end of the
4134 area reserved for registers, skip that area. */
4135 if (! in_regs)
4137 if (reg_parm_stack_space > 0)
4139 if (initial_offset_ptr->var)
4141 initial_offset_ptr->var
4142 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
4143 ssize_int (reg_parm_stack_space));
4144 initial_offset_ptr->constant = 0;
4146 else if (initial_offset_ptr->constant < reg_parm_stack_space)
4147 initial_offset_ptr->constant = reg_parm_stack_space;
4151 part_size_in_regs = (reg_parm_stack_space == 0 ? partial : 0);
4153 sizetree
4154 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
4155 where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
4156 boundary = targetm.calls.function_arg_boundary (passed_mode, type);
4157 round_boundary = targetm.calls.function_arg_round_boundary (passed_mode,
4158 type);
4159 locate->where_pad = where_pad;
4161 /* Alignment can't exceed MAX_SUPPORTED_STACK_ALIGNMENT. */
4162 if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
4163 boundary = MAX_SUPPORTED_STACK_ALIGNMENT;
4165 locate->boundary = boundary;
4167 if (SUPPORTS_STACK_ALIGNMENT)
4169 /* stack_alignment_estimated can't change after stack has been
4170 realigned. */
4171 if (crtl->stack_alignment_estimated < boundary)
4173 if (!crtl->stack_realign_processed)
4174 crtl->stack_alignment_estimated = boundary;
4175 else
4177 /* If stack is realigned and stack alignment value
4178 hasn't been finalized, it is OK not to increase
4179 stack_alignment_estimated. The bigger alignment
4180 requirement is recorded in stack_alignment_needed
4181 below. */
4182 gcc_assert (!crtl->stack_realign_finalized
4183 && crtl->stack_realign_needed);
4188 /* Remember if the outgoing parameter requires extra alignment on the
4189 calling function side. */
4190 if (crtl->stack_alignment_needed < boundary)
4191 crtl->stack_alignment_needed = boundary;
4192 if (crtl->preferred_stack_boundary < boundary)
4193 crtl->preferred_stack_boundary = boundary;
4195 if (ARGS_GROW_DOWNWARD)
4197 locate->slot_offset.constant = -initial_offset_ptr->constant;
4198 if (initial_offset_ptr->var)
4199 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
4200 initial_offset_ptr->var);
4203 tree s2 = sizetree;
4204 if (where_pad != none
4205 && (!tree_fits_uhwi_p (sizetree)
4206 || (tree_to_uhwi (sizetree) * BITS_PER_UNIT) % round_boundary))
4207 s2 = round_up (s2, round_boundary / BITS_PER_UNIT);
4208 SUB_PARM_SIZE (locate->slot_offset, s2);
4211 locate->slot_offset.constant += part_size_in_regs;
4213 if (!in_regs || reg_parm_stack_space > 0)
4214 pad_to_arg_alignment (&locate->slot_offset, boundary,
4215 &locate->alignment_pad);
4217 locate->size.constant = (-initial_offset_ptr->constant
4218 - locate->slot_offset.constant);
4219 if (initial_offset_ptr->var)
4220 locate->size.var = size_binop (MINUS_EXPR,
4221 size_binop (MINUS_EXPR,
4222 ssize_int (0),
4223 initial_offset_ptr->var),
4224 locate->slot_offset.var);
4226 /* Pad_below needs the pre-rounded size to know how much to pad
4227 below. */
4228 locate->offset = locate->slot_offset;
4229 if (where_pad == downward)
4230 pad_below (&locate->offset, passed_mode, sizetree);
4233 else
4235 if (!in_regs || reg_parm_stack_space > 0)
4236 pad_to_arg_alignment (initial_offset_ptr, boundary,
4237 &locate->alignment_pad);
4238 locate->slot_offset = *initial_offset_ptr;
4240 #ifdef PUSH_ROUNDING
4241 if (passed_mode != BLKmode)
4242 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
4243 #endif
4245 /* Pad_below needs the pre-rounded size to know how much to pad below
4246 so this must be done before rounding up. */
4247 locate->offset = locate->slot_offset;
4248 if (where_pad == downward)
4249 pad_below (&locate->offset, passed_mode, sizetree);
4251 if (where_pad != none
4252 && (!tree_fits_uhwi_p (sizetree)
4253 || (tree_to_uhwi (sizetree) * BITS_PER_UNIT) % round_boundary))
4254 sizetree = round_up (sizetree, round_boundary / BITS_PER_UNIT);
4256 ADD_PARM_SIZE (locate->size, sizetree);
4258 locate->size.constant -= part_size_in_regs;
4261 #ifdef FUNCTION_ARG_OFFSET
4262 locate->offset.constant += FUNCTION_ARG_OFFSET (passed_mode, type);
4263 #endif
4266 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
4267 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
4269 static void
4270 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
4271 struct args_size *alignment_pad)
4273 tree save_var = NULL_TREE;
4274 HOST_WIDE_INT save_constant = 0;
4275 int boundary_in_bytes = boundary / BITS_PER_UNIT;
4276 HOST_WIDE_INT sp_offset = STACK_POINTER_OFFSET;
4278 #ifdef SPARC_STACK_BOUNDARY_HACK
4279 /* ??? The SPARC port may claim a STACK_BOUNDARY higher than
4280 the real alignment of %sp. However, when it does this, the
4281 alignment of %sp+STACK_POINTER_OFFSET is STACK_BOUNDARY. */
4282 if (SPARC_STACK_BOUNDARY_HACK)
4283 sp_offset = 0;
4284 #endif
4286 if (boundary > PARM_BOUNDARY)
4288 save_var = offset_ptr->var;
4289 save_constant = offset_ptr->constant;
4292 alignment_pad->var = NULL_TREE;
4293 alignment_pad->constant = 0;
4295 if (boundary > BITS_PER_UNIT)
4297 if (offset_ptr->var)
4299 tree sp_offset_tree = ssize_int (sp_offset);
4300 tree offset = size_binop (PLUS_EXPR,
4301 ARGS_SIZE_TREE (*offset_ptr),
4302 sp_offset_tree);
4303 tree rounded;
4304 if (ARGS_GROW_DOWNWARD)
4305 rounded = round_down (offset, boundary / BITS_PER_UNIT);
4306 else
4307 rounded = round_up (offset, boundary / BITS_PER_UNIT);
4309 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
4310 /* ARGS_SIZE_TREE includes constant term. */
4311 offset_ptr->constant = 0;
4312 if (boundary > PARM_BOUNDARY)
4313 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
4314 save_var);
4316 else
4318 offset_ptr->constant = -sp_offset +
4319 (ARGS_GROW_DOWNWARD
4320 ? FLOOR_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes)
4321 : CEIL_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes));
4323 if (boundary > PARM_BOUNDARY)
4324 alignment_pad->constant = offset_ptr->constant - save_constant;
4329 static void
4330 pad_below (struct args_size *offset_ptr, machine_mode passed_mode, tree sizetree)
4332 if (passed_mode != BLKmode)
4334 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
4335 offset_ptr->constant
4336 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
4337 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
4338 - GET_MODE_SIZE (passed_mode));
4340 else
4342 if (TREE_CODE (sizetree) != INTEGER_CST
4343 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
4345 /* Round the size up to multiple of PARM_BOUNDARY bits. */
4346 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
4347 /* Add it in. */
4348 ADD_PARM_SIZE (*offset_ptr, s2);
4349 SUB_PARM_SIZE (*offset_ptr, sizetree);
4355 /* True if register REGNO was alive at a place where `setjmp' was
4356 called and was set more than once or is an argument. Such regs may
4357 be clobbered by `longjmp'. */
4359 static bool
4360 regno_clobbered_at_setjmp (bitmap setjmp_crosses, int regno)
4362 /* There appear to be cases where some local vars never reach the
4363 backend but have bogus regnos. */
4364 if (regno >= max_reg_num ())
4365 return false;
4367 return ((REG_N_SETS (regno) > 1
4368 || REGNO_REG_SET_P (df_get_live_out (ENTRY_BLOCK_PTR_FOR_FN (cfun)),
4369 regno))
4370 && REGNO_REG_SET_P (setjmp_crosses, regno));
4373 /* Walk the tree of blocks describing the binding levels within a
4374 function and warn about variables the might be killed by setjmp or
4375 vfork. This is done after calling flow_analysis before register
4376 allocation since that will clobber the pseudo-regs to hard
4377 regs. */
4379 static void
4380 setjmp_vars_warning (bitmap setjmp_crosses, tree block)
4382 tree decl, sub;
4384 for (decl = BLOCK_VARS (block); decl; decl = DECL_CHAIN (decl))
4386 if (VAR_P (decl)
4387 && DECL_RTL_SET_P (decl)
4388 && REG_P (DECL_RTL (decl))
4389 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
4390 warning (OPT_Wclobbered, "variable %q+D might be clobbered by"
4391 " %<longjmp%> or %<vfork%>", decl);
4394 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = BLOCK_CHAIN (sub))
4395 setjmp_vars_warning (setjmp_crosses, sub);
4398 /* Do the appropriate part of setjmp_vars_warning
4399 but for arguments instead of local variables. */
4401 static void
4402 setjmp_args_warning (bitmap setjmp_crosses)
4404 tree decl;
4405 for (decl = DECL_ARGUMENTS (current_function_decl);
4406 decl; decl = DECL_CHAIN (decl))
4407 if (DECL_RTL (decl) != 0
4408 && REG_P (DECL_RTL (decl))
4409 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
4410 warning (OPT_Wclobbered,
4411 "argument %q+D might be clobbered by %<longjmp%> or %<vfork%>",
4412 decl);
4415 /* Generate warning messages for variables live across setjmp. */
4417 void
4418 generate_setjmp_warnings (void)
4420 bitmap setjmp_crosses = regstat_get_setjmp_crosses ();
4422 if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS
4423 || bitmap_empty_p (setjmp_crosses))
4424 return;
4426 setjmp_vars_warning (setjmp_crosses, DECL_INITIAL (current_function_decl));
4427 setjmp_args_warning (setjmp_crosses);
4431 /* Reverse the order of elements in the fragment chain T of blocks,
4432 and return the new head of the chain (old last element).
4433 In addition to that clear BLOCK_SAME_RANGE flags when needed
4434 and adjust BLOCK_SUPERCONTEXT from the super fragment to
4435 its super fragment origin. */
4437 static tree
4438 block_fragments_nreverse (tree t)
4440 tree prev = 0, block, next, prev_super = 0;
4441 tree super = BLOCK_SUPERCONTEXT (t);
4442 if (BLOCK_FRAGMENT_ORIGIN (super))
4443 super = BLOCK_FRAGMENT_ORIGIN (super);
4444 for (block = t; block; block = next)
4446 next = BLOCK_FRAGMENT_CHAIN (block);
4447 BLOCK_FRAGMENT_CHAIN (block) = prev;
4448 if ((prev && !BLOCK_SAME_RANGE (prev))
4449 || (BLOCK_FRAGMENT_CHAIN (BLOCK_SUPERCONTEXT (block))
4450 != prev_super))
4451 BLOCK_SAME_RANGE (block) = 0;
4452 prev_super = BLOCK_SUPERCONTEXT (block);
4453 BLOCK_SUPERCONTEXT (block) = super;
4454 prev = block;
4456 t = BLOCK_FRAGMENT_ORIGIN (t);
4457 if (BLOCK_FRAGMENT_CHAIN (BLOCK_SUPERCONTEXT (t))
4458 != prev_super)
4459 BLOCK_SAME_RANGE (t) = 0;
4460 BLOCK_SUPERCONTEXT (t) = super;
4461 return prev;
4464 /* Reverse the order of elements in the chain T of blocks,
4465 and return the new head of the chain (old last element).
4466 Also do the same on subblocks and reverse the order of elements
4467 in BLOCK_FRAGMENT_CHAIN as well. */
4469 static tree
4470 blocks_nreverse_all (tree t)
4472 tree prev = 0, block, next;
4473 for (block = t; block; block = next)
4475 next = BLOCK_CHAIN (block);
4476 BLOCK_CHAIN (block) = prev;
4477 if (BLOCK_FRAGMENT_CHAIN (block)
4478 && BLOCK_FRAGMENT_ORIGIN (block) == NULL_TREE)
4480 BLOCK_FRAGMENT_CHAIN (block)
4481 = block_fragments_nreverse (BLOCK_FRAGMENT_CHAIN (block));
4482 if (!BLOCK_SAME_RANGE (BLOCK_FRAGMENT_CHAIN (block)))
4483 BLOCK_SAME_RANGE (block) = 0;
4485 BLOCK_SUBBLOCKS (block) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block));
4486 prev = block;
4488 return prev;
4492 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
4493 and create duplicate blocks. */
4494 /* ??? Need an option to either create block fragments or to create
4495 abstract origin duplicates of a source block. It really depends
4496 on what optimization has been performed. */
4498 void
4499 reorder_blocks (void)
4501 tree block = DECL_INITIAL (current_function_decl);
4503 if (block == NULL_TREE)
4504 return;
4506 auto_vec<tree, 10> block_stack;
4508 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
4509 clear_block_marks (block);
4511 /* Prune the old trees away, so that they don't get in the way. */
4512 BLOCK_SUBBLOCKS (block) = NULL_TREE;
4513 BLOCK_CHAIN (block) = NULL_TREE;
4515 /* Recreate the block tree from the note nesting. */
4516 reorder_blocks_1 (get_insns (), block, &block_stack);
4517 BLOCK_SUBBLOCKS (block) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block));
4520 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
4522 void
4523 clear_block_marks (tree block)
4525 while (block)
4527 TREE_ASM_WRITTEN (block) = 0;
4528 clear_block_marks (BLOCK_SUBBLOCKS (block));
4529 block = BLOCK_CHAIN (block);
4533 static void
4534 reorder_blocks_1 (rtx_insn *insns, tree current_block,
4535 vec<tree> *p_block_stack)
4537 rtx_insn *insn;
4538 tree prev_beg = NULL_TREE, prev_end = NULL_TREE;
4540 for (insn = insns; insn; insn = NEXT_INSN (insn))
4542 if (NOTE_P (insn))
4544 if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_BEG)
4546 tree block = NOTE_BLOCK (insn);
4547 tree origin;
4549 gcc_assert (BLOCK_FRAGMENT_ORIGIN (block) == NULL_TREE);
4550 origin = block;
4552 if (prev_end)
4553 BLOCK_SAME_RANGE (prev_end) = 0;
4554 prev_end = NULL_TREE;
4556 /* If we have seen this block before, that means it now
4557 spans multiple address regions. Create a new fragment. */
4558 if (TREE_ASM_WRITTEN (block))
4560 tree new_block = copy_node (block);
4562 BLOCK_SAME_RANGE (new_block) = 0;
4563 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
4564 BLOCK_FRAGMENT_CHAIN (new_block)
4565 = BLOCK_FRAGMENT_CHAIN (origin);
4566 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
4568 NOTE_BLOCK (insn) = new_block;
4569 block = new_block;
4572 if (prev_beg == current_block && prev_beg)
4573 BLOCK_SAME_RANGE (block) = 1;
4575 prev_beg = origin;
4577 BLOCK_SUBBLOCKS (block) = 0;
4578 TREE_ASM_WRITTEN (block) = 1;
4579 /* When there's only one block for the entire function,
4580 current_block == block and we mustn't do this, it
4581 will cause infinite recursion. */
4582 if (block != current_block)
4584 tree super;
4585 if (block != origin)
4586 gcc_assert (BLOCK_SUPERCONTEXT (origin) == current_block
4587 || BLOCK_FRAGMENT_ORIGIN (BLOCK_SUPERCONTEXT
4588 (origin))
4589 == current_block);
4590 if (p_block_stack->is_empty ())
4591 super = current_block;
4592 else
4594 super = p_block_stack->last ();
4595 gcc_assert (super == current_block
4596 || BLOCK_FRAGMENT_ORIGIN (super)
4597 == current_block);
4599 BLOCK_SUPERCONTEXT (block) = super;
4600 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
4601 BLOCK_SUBBLOCKS (current_block) = block;
4602 current_block = origin;
4604 p_block_stack->safe_push (block);
4606 else if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_END)
4608 NOTE_BLOCK (insn) = p_block_stack->pop ();
4609 current_block = BLOCK_SUPERCONTEXT (current_block);
4610 if (BLOCK_FRAGMENT_ORIGIN (current_block))
4611 current_block = BLOCK_FRAGMENT_ORIGIN (current_block);
4612 prev_beg = NULL_TREE;
4613 prev_end = BLOCK_SAME_RANGE (NOTE_BLOCK (insn))
4614 ? NOTE_BLOCK (insn) : NULL_TREE;
4617 else
4619 prev_beg = NULL_TREE;
4620 if (prev_end)
4621 BLOCK_SAME_RANGE (prev_end) = 0;
4622 prev_end = NULL_TREE;
4627 /* Reverse the order of elements in the chain T of blocks,
4628 and return the new head of the chain (old last element). */
4630 tree
4631 blocks_nreverse (tree t)
4633 tree prev = 0, block, next;
4634 for (block = t; block; block = next)
4636 next = BLOCK_CHAIN (block);
4637 BLOCK_CHAIN (block) = prev;
4638 prev = block;
4640 return prev;
4643 /* Concatenate two chains of blocks (chained through BLOCK_CHAIN)
4644 by modifying the last node in chain 1 to point to chain 2. */
4646 tree
4647 block_chainon (tree op1, tree op2)
4649 tree t1;
4651 if (!op1)
4652 return op2;
4653 if (!op2)
4654 return op1;
4656 for (t1 = op1; BLOCK_CHAIN (t1); t1 = BLOCK_CHAIN (t1))
4657 continue;
4658 BLOCK_CHAIN (t1) = op2;
4660 #ifdef ENABLE_TREE_CHECKING
4662 tree t2;
4663 for (t2 = op2; t2; t2 = BLOCK_CHAIN (t2))
4664 gcc_assert (t2 != t1);
4666 #endif
4668 return op1;
4671 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
4672 non-NULL, list them all into VECTOR, in a depth-first preorder
4673 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
4674 blocks. */
4676 static int
4677 all_blocks (tree block, tree *vector)
4679 int n_blocks = 0;
4681 while (block)
4683 TREE_ASM_WRITTEN (block) = 0;
4685 /* Record this block. */
4686 if (vector)
4687 vector[n_blocks] = block;
4689 ++n_blocks;
4691 /* Record the subblocks, and their subblocks... */
4692 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
4693 vector ? vector + n_blocks : 0);
4694 block = BLOCK_CHAIN (block);
4697 return n_blocks;
4700 /* Return a vector containing all the blocks rooted at BLOCK. The
4701 number of elements in the vector is stored in N_BLOCKS_P. The
4702 vector is dynamically allocated; it is the caller's responsibility
4703 to call `free' on the pointer returned. */
4705 static tree *
4706 get_block_vector (tree block, int *n_blocks_p)
4708 tree *block_vector;
4710 *n_blocks_p = all_blocks (block, NULL);
4711 block_vector = XNEWVEC (tree, *n_blocks_p);
4712 all_blocks (block, block_vector);
4714 return block_vector;
4717 static GTY(()) int next_block_index = 2;
4719 /* Set BLOCK_NUMBER for all the blocks in FN. */
4721 void
4722 number_blocks (tree fn)
4724 int i;
4725 int n_blocks;
4726 tree *block_vector;
4728 /* For SDB and XCOFF debugging output, we start numbering the blocks
4729 from 1 within each function, rather than keeping a running
4730 count. */
4731 #if SDB_DEBUGGING_INFO || defined (XCOFF_DEBUGGING_INFO)
4732 if (write_symbols == SDB_DEBUG || write_symbols == XCOFF_DEBUG)
4733 next_block_index = 1;
4734 #endif
4736 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
4738 /* The top-level BLOCK isn't numbered at all. */
4739 for (i = 1; i < n_blocks; ++i)
4740 /* We number the blocks from two. */
4741 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
4743 free (block_vector);
4745 return;
4748 /* If VAR is present in a subblock of BLOCK, return the subblock. */
4750 DEBUG_FUNCTION tree
4751 debug_find_var_in_block_tree (tree var, tree block)
4753 tree t;
4755 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
4756 if (t == var)
4757 return block;
4759 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
4761 tree ret = debug_find_var_in_block_tree (var, t);
4762 if (ret)
4763 return ret;
4766 return NULL_TREE;
4769 /* Keep track of whether we're in a dummy function context. If we are,
4770 we don't want to invoke the set_current_function hook, because we'll
4771 get into trouble if the hook calls target_reinit () recursively or
4772 when the initial initialization is not yet complete. */
4774 static bool in_dummy_function;
4776 /* Invoke the target hook when setting cfun. Update the optimization options
4777 if the function uses different options than the default. */
4779 static void
4780 invoke_set_current_function_hook (tree fndecl)
4782 if (!in_dummy_function)
4784 tree opts = ((fndecl)
4785 ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (fndecl)
4786 : optimization_default_node);
4788 if (!opts)
4789 opts = optimization_default_node;
4791 /* Change optimization options if needed. */
4792 if (optimization_current_node != opts)
4794 optimization_current_node = opts;
4795 cl_optimization_restore (&global_options, TREE_OPTIMIZATION (opts));
4798 targetm.set_current_function (fndecl);
4799 this_fn_optabs = this_target_optabs;
4801 if (opts != optimization_default_node)
4803 init_tree_optimization_optabs (opts);
4804 if (TREE_OPTIMIZATION_OPTABS (opts))
4805 this_fn_optabs = (struct target_optabs *)
4806 TREE_OPTIMIZATION_OPTABS (opts);
4811 /* cfun should never be set directly; use this function. */
4813 void
4814 set_cfun (struct function *new_cfun, bool force)
4816 if (cfun != new_cfun || force)
4818 cfun = new_cfun;
4819 invoke_set_current_function_hook (new_cfun ? new_cfun->decl : NULL_TREE);
4820 redirect_edge_var_map_empty ();
4824 /* Initialized with NOGC, making this poisonous to the garbage collector. */
4826 static vec<function *> cfun_stack;
4828 /* Push the current cfun onto the stack, and set cfun to new_cfun. Also set
4829 current_function_decl accordingly. */
4831 void
4832 push_cfun (struct function *new_cfun)
4834 gcc_assert ((!cfun && !current_function_decl)
4835 || (cfun && current_function_decl == cfun->decl));
4836 cfun_stack.safe_push (cfun);
4837 current_function_decl = new_cfun ? new_cfun->decl : NULL_TREE;
4838 set_cfun (new_cfun);
4841 /* Pop cfun from the stack. Also set current_function_decl accordingly. */
4843 void
4844 pop_cfun (void)
4846 struct function *new_cfun = cfun_stack.pop ();
4847 /* When in_dummy_function, we do have a cfun but current_function_decl is
4848 NULL. We also allow pushing NULL cfun and subsequently changing
4849 current_function_decl to something else and have both restored by
4850 pop_cfun. */
4851 gcc_checking_assert (in_dummy_function
4852 || !cfun
4853 || current_function_decl == cfun->decl);
4854 set_cfun (new_cfun);
4855 current_function_decl = new_cfun ? new_cfun->decl : NULL_TREE;
4858 /* Return value of funcdef and increase it. */
4860 get_next_funcdef_no (void)
4862 return funcdef_no++;
4865 /* Return value of funcdef. */
4867 get_last_funcdef_no (void)
4869 return funcdef_no;
4872 /* Allocate a function structure for FNDECL and set its contents
4873 to the defaults. Set cfun to the newly-allocated object.
4874 Some of the helper functions invoked during initialization assume
4875 that cfun has already been set. Therefore, assign the new object
4876 directly into cfun and invoke the back end hook explicitly at the
4877 very end, rather than initializing a temporary and calling set_cfun
4878 on it.
4880 ABSTRACT_P is true if this is a function that will never be seen by
4881 the middle-end. Such functions are front-end concepts (like C++
4882 function templates) that do not correspond directly to functions
4883 placed in object files. */
4885 void
4886 allocate_struct_function (tree fndecl, bool abstract_p)
4888 tree fntype = fndecl ? TREE_TYPE (fndecl) : NULL_TREE;
4890 cfun = ggc_cleared_alloc<function> ();
4892 init_eh_for_function ();
4894 if (init_machine_status)
4895 cfun->machine = (*init_machine_status) ();
4897 #ifdef OVERRIDE_ABI_FORMAT
4898 OVERRIDE_ABI_FORMAT (fndecl);
4899 #endif
4901 if (fndecl != NULL_TREE)
4903 DECL_STRUCT_FUNCTION (fndecl) = cfun;
4904 cfun->decl = fndecl;
4905 current_function_funcdef_no = get_next_funcdef_no ();
4908 invoke_set_current_function_hook (fndecl);
4910 if (fndecl != NULL_TREE)
4912 tree result = DECL_RESULT (fndecl);
4914 if (!abstract_p)
4916 /* Now that we have activated any function-specific attributes
4917 that might affect layout, particularly vector modes, relayout
4918 each of the parameters and the result. */
4919 relayout_decl (result);
4920 for (tree parm = DECL_ARGUMENTS (fndecl); parm;
4921 parm = DECL_CHAIN (parm))
4922 relayout_decl (parm);
4924 /* Similarly relayout the function decl. */
4925 targetm.target_option.relayout_function (fndecl);
4928 if (!abstract_p && aggregate_value_p (result, fndecl))
4930 #ifdef PCC_STATIC_STRUCT_RETURN
4931 cfun->returns_pcc_struct = 1;
4932 #endif
4933 cfun->returns_struct = 1;
4936 cfun->stdarg = stdarg_p (fntype);
4938 /* Assume all registers in stdarg functions need to be saved. */
4939 cfun->va_list_gpr_size = VA_LIST_MAX_GPR_SIZE;
4940 cfun->va_list_fpr_size = VA_LIST_MAX_FPR_SIZE;
4942 /* ??? This could be set on a per-function basis by the front-end
4943 but is this worth the hassle? */
4944 cfun->can_throw_non_call_exceptions = flag_non_call_exceptions;
4945 cfun->can_delete_dead_exceptions = flag_delete_dead_exceptions;
4947 if (!profile_flag && !flag_instrument_function_entry_exit)
4948 DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl) = 1;
4952 /* This is like allocate_struct_function, but pushes a new cfun for FNDECL
4953 instead of just setting it. */
4955 void
4956 push_struct_function (tree fndecl)
4958 /* When in_dummy_function we might be in the middle of a pop_cfun and
4959 current_function_decl and cfun may not match. */
4960 gcc_assert (in_dummy_function
4961 || (!cfun && !current_function_decl)
4962 || (cfun && current_function_decl == cfun->decl));
4963 cfun_stack.safe_push (cfun);
4964 current_function_decl = fndecl;
4965 allocate_struct_function (fndecl, false);
4968 /* Reset crtl and other non-struct-function variables to defaults as
4969 appropriate for emitting rtl at the start of a function. */
4971 static void
4972 prepare_function_start (void)
4974 gcc_assert (!get_last_insn ());
4975 init_temp_slots ();
4976 init_emit ();
4977 init_varasm_status ();
4978 init_expr ();
4979 default_rtl_profile ();
4981 if (flag_stack_usage_info)
4983 cfun->su = ggc_cleared_alloc<stack_usage> ();
4984 cfun->su->static_stack_size = -1;
4987 cse_not_expected = ! optimize;
4989 /* Caller save not needed yet. */
4990 caller_save_needed = 0;
4992 /* We haven't done register allocation yet. */
4993 reg_renumber = 0;
4995 /* Indicate that we have not instantiated virtual registers yet. */
4996 virtuals_instantiated = 0;
4998 /* Indicate that we want CONCATs now. */
4999 generating_concat_p = 1;
5001 /* Indicate we have no need of a frame pointer yet. */
5002 frame_pointer_needed = 0;
5005 void
5006 push_dummy_function (bool with_decl)
5008 tree fn_decl, fn_type, fn_result_decl;
5010 gcc_assert (!in_dummy_function);
5011 in_dummy_function = true;
5013 if (with_decl)
5015 fn_type = build_function_type_list (void_type_node, NULL_TREE);
5016 fn_decl = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL, NULL_TREE,
5017 fn_type);
5018 fn_result_decl = build_decl (UNKNOWN_LOCATION, RESULT_DECL,
5019 NULL_TREE, void_type_node);
5020 DECL_RESULT (fn_decl) = fn_result_decl;
5022 else
5023 fn_decl = NULL_TREE;
5025 push_struct_function (fn_decl);
5028 /* Initialize the rtl expansion mechanism so that we can do simple things
5029 like generate sequences. This is used to provide a context during global
5030 initialization of some passes. You must call expand_dummy_function_end
5031 to exit this context. */
5033 void
5034 init_dummy_function_start (void)
5036 push_dummy_function (false);
5037 prepare_function_start ();
5040 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
5041 and initialize static variables for generating RTL for the statements
5042 of the function. */
5044 void
5045 init_function_start (tree subr)
5047 /* Initialize backend, if needed. */
5048 initialize_rtl ();
5050 prepare_function_start ();
5051 decide_function_section (subr);
5053 /* Warn if this value is an aggregate type,
5054 regardless of which calling convention we are using for it. */
5055 if (AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
5056 warning (OPT_Waggregate_return, "function returns an aggregate");
5059 /* Expand code to verify the stack_protect_guard. This is invoked at
5060 the end of a function to be protected. */
5062 void
5063 stack_protect_epilogue (void)
5065 tree guard_decl = targetm.stack_protect_guard ();
5066 rtx_code_label *label = gen_label_rtx ();
5067 rtx x, y;
5068 rtx_insn *seq;
5070 x = expand_normal (crtl->stack_protect_guard);
5071 if (guard_decl)
5072 y = expand_normal (guard_decl);
5073 else
5074 y = const0_rtx;
5076 /* Allow the target to compare Y with X without leaking either into
5077 a register. */
5078 if (targetm.have_stack_protect_test ()
5079 && ((seq = targetm.gen_stack_protect_test (x, y, label)) != NULL_RTX))
5080 emit_insn (seq);
5081 else
5082 emit_cmp_and_jump_insns (x, y, EQ, NULL_RTX, ptr_mode, 1, label);
5084 /* The noreturn predictor has been moved to the tree level. The rtl-level
5085 predictors estimate this branch about 20%, which isn't enough to get
5086 things moved out of line. Since this is the only extant case of adding
5087 a noreturn function at the rtl level, it doesn't seem worth doing ought
5088 except adding the prediction by hand. */
5089 rtx_insn *tmp = get_last_insn ();
5090 if (JUMP_P (tmp))
5091 predict_insn_def (tmp, PRED_NORETURN, TAKEN);
5093 expand_call (targetm.stack_protect_fail (), NULL_RTX, /*ignore=*/true);
5094 free_temp_slots ();
5095 emit_label (label);
5098 /* Start the RTL for a new function, and set variables used for
5099 emitting RTL.
5100 SUBR is the FUNCTION_DECL node.
5101 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
5102 the function's parameters, which must be run at any return statement. */
5104 void
5105 expand_function_start (tree subr)
5107 /* Make sure volatile mem refs aren't considered
5108 valid operands of arithmetic insns. */
5109 init_recog_no_volatile ();
5111 crtl->profile
5112 = (profile_flag
5113 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
5115 crtl->limit_stack
5116 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
5118 /* Make the label for return statements to jump to. Do not special
5119 case machines with special return instructions -- they will be
5120 handled later during jump, ifcvt, or epilogue creation. */
5121 return_label = gen_label_rtx ();
5123 /* Initialize rtx used to return the value. */
5124 /* Do this before assign_parms so that we copy the struct value address
5125 before any library calls that assign parms might generate. */
5127 /* Decide whether to return the value in memory or in a register. */
5128 tree res = DECL_RESULT (subr);
5129 if (aggregate_value_p (res, subr))
5131 /* Returning something that won't go in a register. */
5132 rtx value_address = 0;
5134 #ifdef PCC_STATIC_STRUCT_RETURN
5135 if (cfun->returns_pcc_struct)
5137 int size = int_size_in_bytes (TREE_TYPE (res));
5138 value_address = assemble_static_space (size);
5140 else
5141 #endif
5143 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 2);
5144 /* Expect to be passed the address of a place to store the value.
5145 If it is passed as an argument, assign_parms will take care of
5146 it. */
5147 if (sv)
5149 value_address = gen_reg_rtx (Pmode);
5150 emit_move_insn (value_address, sv);
5153 if (value_address)
5155 rtx x = value_address;
5156 if (!DECL_BY_REFERENCE (res))
5158 x = gen_rtx_MEM (DECL_MODE (res), x);
5159 set_mem_attributes (x, res, 1);
5161 set_parm_rtl (res, x);
5164 else if (DECL_MODE (res) == VOIDmode)
5165 /* If return mode is void, this decl rtl should not be used. */
5166 set_parm_rtl (res, NULL_RTX);
5167 else
5169 /* Compute the return values into a pseudo reg, which we will copy
5170 into the true return register after the cleanups are done. */
5171 tree return_type = TREE_TYPE (res);
5173 /* If we may coalesce this result, make sure it has the expected mode
5174 in case it was promoted. But we need not bother about BLKmode. */
5175 machine_mode promoted_mode
5176 = flag_tree_coalesce_vars && is_gimple_reg (res)
5177 ? promote_ssa_mode (ssa_default_def (cfun, res), NULL)
5178 : BLKmode;
5180 if (promoted_mode != BLKmode)
5181 set_parm_rtl (res, gen_reg_rtx (promoted_mode));
5182 else if (TYPE_MODE (return_type) != BLKmode
5183 && targetm.calls.return_in_msb (return_type))
5184 /* expand_function_end will insert the appropriate padding in
5185 this case. Use the return value's natural (unpadded) mode
5186 within the function proper. */
5187 set_parm_rtl (res, gen_reg_rtx (TYPE_MODE (return_type)));
5188 else
5190 /* In order to figure out what mode to use for the pseudo, we
5191 figure out what the mode of the eventual return register will
5192 actually be, and use that. */
5193 rtx hard_reg = hard_function_value (return_type, subr, 0, 1);
5195 /* Structures that are returned in registers are not
5196 aggregate_value_p, so we may see a PARALLEL or a REG. */
5197 if (REG_P (hard_reg))
5198 set_parm_rtl (res, gen_reg_rtx (GET_MODE (hard_reg)));
5199 else
5201 gcc_assert (GET_CODE (hard_reg) == PARALLEL);
5202 set_parm_rtl (res, gen_group_rtx (hard_reg));
5206 /* Set DECL_REGISTER flag so that expand_function_end will copy the
5207 result to the real return register(s). */
5208 DECL_REGISTER (res) = 1;
5210 if (chkp_function_instrumented_p (current_function_decl))
5212 tree return_type = TREE_TYPE (res);
5213 rtx bounds = targetm.calls.chkp_function_value_bounds (return_type,
5214 subr, 1);
5215 SET_DECL_BOUNDS_RTL (res, bounds);
5219 /* Initialize rtx for parameters and local variables.
5220 In some cases this requires emitting insns. */
5221 assign_parms (subr);
5223 /* If function gets a static chain arg, store it. */
5224 if (cfun->static_chain_decl)
5226 tree parm = cfun->static_chain_decl;
5227 rtx local, chain;
5228 rtx_insn *insn;
5229 int unsignedp;
5231 local = gen_reg_rtx (promote_decl_mode (parm, &unsignedp));
5232 chain = targetm.calls.static_chain (current_function_decl, true);
5234 set_decl_incoming_rtl (parm, chain, false);
5235 set_parm_rtl (parm, local);
5236 mark_reg_pointer (local, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
5238 if (GET_MODE (local) != GET_MODE (chain))
5240 convert_move (local, chain, unsignedp);
5241 insn = get_last_insn ();
5243 else
5244 insn = emit_move_insn (local, chain);
5246 /* Mark the register as eliminable, similar to parameters. */
5247 if (MEM_P (chain)
5248 && reg_mentioned_p (arg_pointer_rtx, XEXP (chain, 0)))
5249 set_dst_reg_note (insn, REG_EQUIV, chain, local);
5251 /* If we aren't optimizing, save the static chain onto the stack. */
5252 if (!optimize)
5254 tree saved_static_chain_decl
5255 = build_decl (DECL_SOURCE_LOCATION (parm), VAR_DECL,
5256 DECL_NAME (parm), TREE_TYPE (parm));
5257 rtx saved_static_chain_rtx
5258 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
5259 SET_DECL_RTL (saved_static_chain_decl, saved_static_chain_rtx);
5260 emit_move_insn (saved_static_chain_rtx, chain);
5261 SET_DECL_VALUE_EXPR (parm, saved_static_chain_decl);
5262 DECL_HAS_VALUE_EXPR_P (parm) = 1;
5266 /* If the function receives a non-local goto, then store the
5267 bits we need to restore the frame pointer. */
5268 if (cfun->nonlocal_goto_save_area)
5270 tree t_save;
5271 rtx r_save;
5273 tree var = TREE_OPERAND (cfun->nonlocal_goto_save_area, 0);
5274 gcc_assert (DECL_RTL_SET_P (var));
5276 t_save = build4 (ARRAY_REF,
5277 TREE_TYPE (TREE_TYPE (cfun->nonlocal_goto_save_area)),
5278 cfun->nonlocal_goto_save_area,
5279 integer_zero_node, NULL_TREE, NULL_TREE);
5280 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
5281 gcc_assert (GET_MODE (r_save) == Pmode);
5283 emit_move_insn (r_save, targetm.builtin_setjmp_frame_value ());
5284 update_nonlocal_goto_save_area ();
5287 /* The following was moved from init_function_start.
5288 The move is supposed to make sdb output more accurate. */
5289 /* Indicate the beginning of the function body,
5290 as opposed to parm setup. */
5291 emit_note (NOTE_INSN_FUNCTION_BEG);
5293 gcc_assert (NOTE_P (get_last_insn ()));
5295 parm_birth_insn = get_last_insn ();
5297 if (crtl->profile)
5299 #ifdef PROFILE_HOOK
5300 PROFILE_HOOK (current_function_funcdef_no);
5301 #endif
5304 /* If we are doing generic stack checking, the probe should go here. */
5305 if (flag_stack_check == GENERIC_STACK_CHECK)
5306 stack_check_probe_note = emit_note (NOTE_INSN_DELETED);
5309 void
5310 pop_dummy_function (void)
5312 pop_cfun ();
5313 in_dummy_function = false;
5316 /* Undo the effects of init_dummy_function_start. */
5317 void
5318 expand_dummy_function_end (void)
5320 gcc_assert (in_dummy_function);
5322 /* End any sequences that failed to be closed due to syntax errors. */
5323 while (in_sequence_p ())
5324 end_sequence ();
5326 /* Outside function body, can't compute type's actual size
5327 until next function's body starts. */
5329 free_after_parsing (cfun);
5330 free_after_compilation (cfun);
5331 pop_dummy_function ();
5334 /* Helper for diddle_return_value. */
5336 void
5337 diddle_return_value_1 (void (*doit) (rtx, void *), void *arg, rtx outgoing)
5339 if (! outgoing)
5340 return;
5342 if (REG_P (outgoing))
5343 (*doit) (outgoing, arg);
5344 else if (GET_CODE (outgoing) == PARALLEL)
5346 int i;
5348 for (i = 0; i < XVECLEN (outgoing, 0); i++)
5350 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
5352 if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
5353 (*doit) (x, arg);
5358 /* Call DOIT for each hard register used as a return value from
5359 the current function. */
5361 void
5362 diddle_return_value (void (*doit) (rtx, void *), void *arg)
5364 diddle_return_value_1 (doit, arg, crtl->return_bnd);
5365 diddle_return_value_1 (doit, arg, crtl->return_rtx);
5368 static void
5369 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
5371 emit_clobber (reg);
5374 void
5375 clobber_return_register (void)
5377 diddle_return_value (do_clobber_return_reg, NULL);
5379 /* In case we do use pseudo to return value, clobber it too. */
5380 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
5382 tree decl_result = DECL_RESULT (current_function_decl);
5383 rtx decl_rtl = DECL_RTL (decl_result);
5384 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
5386 do_clobber_return_reg (decl_rtl, NULL);
5391 static void
5392 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
5394 emit_use (reg);
5397 static void
5398 use_return_register (void)
5400 diddle_return_value (do_use_return_reg, NULL);
5403 /* Set the location of the insn chain starting at INSN to LOC. */
5405 static void
5406 set_insn_locations (rtx_insn *insn, int loc)
5408 while (insn != NULL)
5410 if (INSN_P (insn))
5411 INSN_LOCATION (insn) = loc;
5412 insn = NEXT_INSN (insn);
5416 /* Generate RTL for the end of the current function. */
5418 void
5419 expand_function_end (void)
5421 /* If arg_pointer_save_area was referenced only from a nested
5422 function, we will not have initialized it yet. Do that now. */
5423 if (arg_pointer_save_area && ! crtl->arg_pointer_save_area_init)
5424 get_arg_pointer_save_area ();
5426 /* If we are doing generic stack checking and this function makes calls,
5427 do a stack probe at the start of the function to ensure we have enough
5428 space for another stack frame. */
5429 if (flag_stack_check == GENERIC_STACK_CHECK)
5431 rtx_insn *insn, *seq;
5433 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
5434 if (CALL_P (insn))
5436 rtx max_frame_size = GEN_INT (STACK_CHECK_MAX_FRAME_SIZE);
5437 start_sequence ();
5438 if (STACK_CHECK_MOVING_SP)
5439 anti_adjust_stack_and_probe (max_frame_size, true);
5440 else
5441 probe_stack_range (STACK_OLD_CHECK_PROTECT, max_frame_size);
5442 seq = get_insns ();
5443 end_sequence ();
5444 set_insn_locations (seq, prologue_location);
5445 emit_insn_before (seq, stack_check_probe_note);
5446 break;
5450 /* End any sequences that failed to be closed due to syntax errors. */
5451 while (in_sequence_p ())
5452 end_sequence ();
5454 clear_pending_stack_adjust ();
5455 do_pending_stack_adjust ();
5457 /* Output a linenumber for the end of the function.
5458 SDB depends on this. */
5459 set_curr_insn_location (input_location);
5461 /* Before the return label (if any), clobber the return
5462 registers so that they are not propagated live to the rest of
5463 the function. This can only happen with functions that drop
5464 through; if there had been a return statement, there would
5465 have either been a return rtx, or a jump to the return label.
5467 We delay actual code generation after the current_function_value_rtx
5468 is computed. */
5469 rtx_insn *clobber_after = get_last_insn ();
5471 /* Output the label for the actual return from the function. */
5472 emit_label (return_label);
5474 if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ)
5476 /* Let except.c know where it should emit the call to unregister
5477 the function context for sjlj exceptions. */
5478 if (flag_exceptions)
5479 sjlj_emit_function_exit_after (get_last_insn ());
5481 else
5483 /* We want to ensure that instructions that may trap are not
5484 moved into the epilogue by scheduling, because we don't
5485 always emit unwind information for the epilogue. */
5486 if (cfun->can_throw_non_call_exceptions)
5487 emit_insn (gen_blockage ());
5490 /* If this is an implementation of throw, do what's necessary to
5491 communicate between __builtin_eh_return and the epilogue. */
5492 expand_eh_return ();
5494 /* If scalar return value was computed in a pseudo-reg, or was a named
5495 return value that got dumped to the stack, copy that to the hard
5496 return register. */
5497 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
5499 tree decl_result = DECL_RESULT (current_function_decl);
5500 rtx decl_rtl = DECL_RTL (decl_result);
5502 if (REG_P (decl_rtl)
5503 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
5504 : DECL_REGISTER (decl_result))
5506 rtx real_decl_rtl = crtl->return_rtx;
5508 /* This should be set in assign_parms. */
5509 gcc_assert (REG_FUNCTION_VALUE_P (real_decl_rtl));
5511 /* If this is a BLKmode structure being returned in registers,
5512 then use the mode computed in expand_return. Note that if
5513 decl_rtl is memory, then its mode may have been changed,
5514 but that crtl->return_rtx has not. */
5515 if (GET_MODE (real_decl_rtl) == BLKmode)
5516 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
5518 /* If a non-BLKmode return value should be padded at the least
5519 significant end of the register, shift it left by the appropriate
5520 amount. BLKmode results are handled using the group load/store
5521 machinery. */
5522 if (TYPE_MODE (TREE_TYPE (decl_result)) != BLKmode
5523 && REG_P (real_decl_rtl)
5524 && targetm.calls.return_in_msb (TREE_TYPE (decl_result)))
5526 emit_move_insn (gen_rtx_REG (GET_MODE (decl_rtl),
5527 REGNO (real_decl_rtl)),
5528 decl_rtl);
5529 shift_return_value (GET_MODE (decl_rtl), true, real_decl_rtl);
5531 else if (GET_CODE (real_decl_rtl) == PARALLEL)
5533 /* If expand_function_start has created a PARALLEL for decl_rtl,
5534 move the result to the real return registers. Otherwise, do
5535 a group load from decl_rtl for a named return. */
5536 if (GET_CODE (decl_rtl) == PARALLEL)
5537 emit_group_move (real_decl_rtl, decl_rtl);
5538 else
5539 emit_group_load (real_decl_rtl, decl_rtl,
5540 TREE_TYPE (decl_result),
5541 int_size_in_bytes (TREE_TYPE (decl_result)));
5543 /* In the case of complex integer modes smaller than a word, we'll
5544 need to generate some non-trivial bitfield insertions. Do that
5545 on a pseudo and not the hard register. */
5546 else if (GET_CODE (decl_rtl) == CONCAT
5547 && GET_MODE_CLASS (GET_MODE (decl_rtl)) == MODE_COMPLEX_INT
5548 && GET_MODE_BITSIZE (GET_MODE (decl_rtl)) <= BITS_PER_WORD)
5550 int old_generating_concat_p;
5551 rtx tmp;
5553 old_generating_concat_p = generating_concat_p;
5554 generating_concat_p = 0;
5555 tmp = gen_reg_rtx (GET_MODE (decl_rtl));
5556 generating_concat_p = old_generating_concat_p;
5558 emit_move_insn (tmp, decl_rtl);
5559 emit_move_insn (real_decl_rtl, tmp);
5561 /* If a named return value dumped decl_return to memory, then
5562 we may need to re-do the PROMOTE_MODE signed/unsigned
5563 extension. */
5564 else if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
5566 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
5567 promote_function_mode (TREE_TYPE (decl_result),
5568 GET_MODE (decl_rtl), &unsignedp,
5569 TREE_TYPE (current_function_decl), 1);
5571 convert_move (real_decl_rtl, decl_rtl, unsignedp);
5573 else
5574 emit_move_insn (real_decl_rtl, decl_rtl);
5578 /* If returning a structure, arrange to return the address of the value
5579 in a place where debuggers expect to find it.
5581 If returning a structure PCC style,
5582 the caller also depends on this value.
5583 And cfun->returns_pcc_struct is not necessarily set. */
5584 if ((cfun->returns_struct || cfun->returns_pcc_struct)
5585 && !targetm.calls.omit_struct_return_reg)
5587 rtx value_address = DECL_RTL (DECL_RESULT (current_function_decl));
5588 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
5589 rtx outgoing;
5591 if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
5592 type = TREE_TYPE (type);
5593 else
5594 value_address = XEXP (value_address, 0);
5596 outgoing = targetm.calls.function_value (build_pointer_type (type),
5597 current_function_decl, true);
5599 /* Mark this as a function return value so integrate will delete the
5600 assignment and USE below when inlining this function. */
5601 REG_FUNCTION_VALUE_P (outgoing) = 1;
5603 /* The address may be ptr_mode and OUTGOING may be Pmode. */
5604 value_address = convert_memory_address (GET_MODE (outgoing),
5605 value_address);
5607 emit_move_insn (outgoing, value_address);
5609 /* Show return register used to hold result (in this case the address
5610 of the result. */
5611 crtl->return_rtx = outgoing;
5614 /* Emit the actual code to clobber return register. Don't emit
5615 it if clobber_after is a barrier, then the previous basic block
5616 certainly doesn't fall thru into the exit block. */
5617 if (!BARRIER_P (clobber_after))
5619 start_sequence ();
5620 clobber_return_register ();
5621 rtx_insn *seq = get_insns ();
5622 end_sequence ();
5624 emit_insn_after (seq, clobber_after);
5627 /* Output the label for the naked return from the function. */
5628 if (naked_return_label)
5629 emit_label (naked_return_label);
5631 /* @@@ This is a kludge. We want to ensure that instructions that
5632 may trap are not moved into the epilogue by scheduling, because
5633 we don't always emit unwind information for the epilogue. */
5634 if (cfun->can_throw_non_call_exceptions
5635 && targetm_common.except_unwind_info (&global_options) != UI_SJLJ)
5636 emit_insn (gen_blockage ());
5638 /* If stack protection is enabled for this function, check the guard. */
5639 if (crtl->stack_protect_guard && targetm.stack_protect_runtime_enabled_p ())
5640 stack_protect_epilogue ();
5642 /* If we had calls to alloca, and this machine needs
5643 an accurate stack pointer to exit the function,
5644 insert some code to save and restore the stack pointer. */
5645 if (! EXIT_IGNORE_STACK
5646 && cfun->calls_alloca)
5648 rtx tem = 0;
5650 start_sequence ();
5651 emit_stack_save (SAVE_FUNCTION, &tem);
5652 rtx_insn *seq = get_insns ();
5653 end_sequence ();
5654 emit_insn_before (seq, parm_birth_insn);
5656 emit_stack_restore (SAVE_FUNCTION, tem);
5659 /* ??? This should no longer be necessary since stupid is no longer with
5660 us, but there are some parts of the compiler (eg reload_combine, and
5661 sh mach_dep_reorg) that still try and compute their own lifetime info
5662 instead of using the general framework. */
5663 use_return_register ();
5667 get_arg_pointer_save_area (void)
5669 rtx ret = arg_pointer_save_area;
5671 if (! ret)
5673 ret = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
5674 arg_pointer_save_area = ret;
5677 if (! crtl->arg_pointer_save_area_init)
5679 /* Save the arg pointer at the beginning of the function. The
5680 generated stack slot may not be a valid memory address, so we
5681 have to check it and fix it if necessary. */
5682 start_sequence ();
5683 emit_move_insn (validize_mem (copy_rtx (ret)),
5684 crtl->args.internal_arg_pointer);
5685 rtx_insn *seq = get_insns ();
5686 end_sequence ();
5688 push_topmost_sequence ();
5689 emit_insn_after (seq, entry_of_function ());
5690 pop_topmost_sequence ();
5692 crtl->arg_pointer_save_area_init = true;
5695 return ret;
5698 /* Add a list of INSNS to the hash HASHP, possibly allocating HASHP
5699 for the first time. */
5701 static void
5702 record_insns (rtx_insn *insns, rtx end, hash_table<insn_cache_hasher> **hashp)
5704 rtx_insn *tmp;
5705 hash_table<insn_cache_hasher> *hash = *hashp;
5707 if (hash == NULL)
5708 *hashp = hash = hash_table<insn_cache_hasher>::create_ggc (17);
5710 for (tmp = insns; tmp != end; tmp = NEXT_INSN (tmp))
5712 rtx *slot = hash->find_slot (tmp, INSERT);
5713 gcc_assert (*slot == NULL);
5714 *slot = tmp;
5718 /* INSN has been duplicated or replaced by as COPY, perhaps by duplicating a
5719 basic block, splitting or peepholes. If INSN is a prologue or epilogue
5720 insn, then record COPY as well. */
5722 void
5723 maybe_copy_prologue_epilogue_insn (rtx insn, rtx copy)
5725 hash_table<insn_cache_hasher> *hash;
5726 rtx *slot;
5728 hash = epilogue_insn_hash;
5729 if (!hash || !hash->find (insn))
5731 hash = prologue_insn_hash;
5732 if (!hash || !hash->find (insn))
5733 return;
5736 slot = hash->find_slot (copy, INSERT);
5737 gcc_assert (*slot == NULL);
5738 *slot = copy;
5741 /* Determine if any INSNs in HASH are, or are part of, INSN. Because
5742 we can be running after reorg, SEQUENCE rtl is possible. */
5744 static bool
5745 contains (const rtx_insn *insn, hash_table<insn_cache_hasher> *hash)
5747 if (hash == NULL)
5748 return false;
5750 if (NONJUMP_INSN_P (insn) && GET_CODE (PATTERN (insn)) == SEQUENCE)
5752 rtx_sequence *seq = as_a <rtx_sequence *> (PATTERN (insn));
5753 int i;
5754 for (i = seq->len () - 1; i >= 0; i--)
5755 if (hash->find (seq->element (i)))
5756 return true;
5757 return false;
5760 return hash->find (const_cast<rtx_insn *> (insn)) != NULL;
5764 prologue_contains (const rtx_insn *insn)
5766 return contains (insn, prologue_insn_hash);
5770 epilogue_contains (const rtx_insn *insn)
5772 return contains (insn, epilogue_insn_hash);
5776 prologue_epilogue_contains (const rtx_insn *insn)
5778 if (contains (insn, prologue_insn_hash))
5779 return 1;
5780 if (contains (insn, epilogue_insn_hash))
5781 return 1;
5782 return 0;
5785 void
5786 record_prologue_seq (rtx_insn *seq)
5788 record_insns (seq, NULL, &prologue_insn_hash);
5791 void
5792 record_epilogue_seq (rtx_insn *seq)
5794 record_insns (seq, NULL, &epilogue_insn_hash);
5797 /* Set JUMP_LABEL for a return insn. */
5799 void
5800 set_return_jump_label (rtx_insn *returnjump)
5802 rtx pat = PATTERN (returnjump);
5803 if (GET_CODE (pat) == PARALLEL)
5804 pat = XVECEXP (pat, 0, 0);
5805 if (ANY_RETURN_P (pat))
5806 JUMP_LABEL (returnjump) = pat;
5807 else
5808 JUMP_LABEL (returnjump) = ret_rtx;
5811 /* Return a sequence to be used as the split prologue for the current
5812 function, or NULL. */
5814 static rtx_insn *
5815 make_split_prologue_seq (void)
5817 if (!flag_split_stack
5818 || lookup_attribute ("no_split_stack", DECL_ATTRIBUTES (cfun->decl)))
5819 return NULL;
5821 start_sequence ();
5822 emit_insn (targetm.gen_split_stack_prologue ());
5823 rtx_insn *seq = get_insns ();
5824 end_sequence ();
5826 record_insns (seq, NULL, &prologue_insn_hash);
5827 set_insn_locations (seq, prologue_location);
5829 return seq;
5832 /* Return a sequence to be used as the prologue for the current function,
5833 or NULL. */
5835 static rtx_insn *
5836 make_prologue_seq (void)
5838 if (!targetm.have_prologue ())
5839 return NULL;
5841 start_sequence ();
5842 rtx_insn *seq = targetm.gen_prologue ();
5843 emit_insn (seq);
5845 /* Insert an explicit USE for the frame pointer
5846 if the profiling is on and the frame pointer is required. */
5847 if (crtl->profile && frame_pointer_needed)
5848 emit_use (hard_frame_pointer_rtx);
5850 /* Retain a map of the prologue insns. */
5851 record_insns (seq, NULL, &prologue_insn_hash);
5852 emit_note (NOTE_INSN_PROLOGUE_END);
5854 /* Ensure that instructions are not moved into the prologue when
5855 profiling is on. The call to the profiling routine can be
5856 emitted within the live range of a call-clobbered register. */
5857 if (!targetm.profile_before_prologue () && crtl->profile)
5858 emit_insn (gen_blockage ());
5860 seq = get_insns ();
5861 end_sequence ();
5862 set_insn_locations (seq, prologue_location);
5864 return seq;
5867 /* Return a sequence to be used as the epilogue for the current function,
5868 or NULL. */
5870 static rtx_insn *
5871 make_epilogue_seq (void)
5873 if (!targetm.have_epilogue ())
5874 return NULL;
5876 start_sequence ();
5877 emit_note (NOTE_INSN_EPILOGUE_BEG);
5878 rtx_insn *seq = targetm.gen_epilogue ();
5879 if (seq)
5880 emit_jump_insn (seq);
5882 /* Retain a map of the epilogue insns. */
5883 record_insns (seq, NULL, &epilogue_insn_hash);
5884 set_insn_locations (seq, epilogue_location);
5886 seq = get_insns ();
5887 rtx_insn *returnjump = get_last_insn ();
5888 end_sequence ();
5890 if (JUMP_P (returnjump))
5891 set_return_jump_label (returnjump);
5893 return seq;
5897 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
5898 this into place with notes indicating where the prologue ends and where
5899 the epilogue begins. Update the basic block information when possible.
5901 Notes on epilogue placement:
5902 There are several kinds of edges to the exit block:
5903 * a single fallthru edge from LAST_BB
5904 * possibly, edges from blocks containing sibcalls
5905 * possibly, fake edges from infinite loops
5907 The epilogue is always emitted on the fallthru edge from the last basic
5908 block in the function, LAST_BB, into the exit block.
5910 If LAST_BB is empty except for a label, it is the target of every
5911 other basic block in the function that ends in a return. If a
5912 target has a return or simple_return pattern (possibly with
5913 conditional variants), these basic blocks can be changed so that a
5914 return insn is emitted into them, and their target is adjusted to
5915 the real exit block.
5917 Notes on shrink wrapping: We implement a fairly conservative
5918 version of shrink-wrapping rather than the textbook one. We only
5919 generate a single prologue and a single epilogue. This is
5920 sufficient to catch a number of interesting cases involving early
5921 exits.
5923 First, we identify the blocks that require the prologue to occur before
5924 them. These are the ones that modify a call-saved register, or reference
5925 any of the stack or frame pointer registers. To simplify things, we then
5926 mark everything reachable from these blocks as also requiring a prologue.
5927 This takes care of loops automatically, and avoids the need to examine
5928 whether MEMs reference the frame, since it is sufficient to check for
5929 occurrences of the stack or frame pointer.
5931 We then compute the set of blocks for which the need for a prologue
5932 is anticipatable (borrowing terminology from the shrink-wrapping
5933 description in Muchnick's book). These are the blocks which either
5934 require a prologue themselves, or those that have only successors
5935 where the prologue is anticipatable. The prologue needs to be
5936 inserted on all edges from BB1->BB2 where BB2 is in ANTIC and BB1
5937 is not. For the moment, we ensure that only one such edge exists.
5939 The epilogue is placed as described above, but we make a
5940 distinction between inserting return and simple_return patterns
5941 when modifying other blocks that end in a return. Blocks that end
5942 in a sibcall omit the sibcall_epilogue if the block is not in
5943 ANTIC. */
5945 void
5946 thread_prologue_and_epilogue_insns (void)
5948 df_analyze ();
5950 /* Can't deal with multiple successors of the entry block at the
5951 moment. Function should always have at least one entry
5952 point. */
5953 gcc_assert (single_succ_p (ENTRY_BLOCK_PTR_FOR_FN (cfun)));
5955 edge entry_edge = single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun));
5956 edge orig_entry_edge = entry_edge;
5958 rtx_insn *split_prologue_seq = make_split_prologue_seq ();
5959 rtx_insn *prologue_seq = make_prologue_seq ();
5960 rtx_insn *epilogue_seq = make_epilogue_seq ();
5962 /* Try to perform a kind of shrink-wrapping, making sure the
5963 prologue/epilogue is emitted only around those parts of the
5964 function that require it. */
5965 try_shrink_wrapping (&entry_edge, prologue_seq);
5967 /* If the target can handle splitting the prologue/epilogue into separate
5968 components, try to shrink-wrap these components separately. */
5969 try_shrink_wrapping_separate (entry_edge->dest);
5971 /* If that did anything for any component we now need the generate the
5972 "main" prologue again. Because some targets require some of these
5973 to be called in a specific order (i386 requires the split prologue
5974 to be first, for example), we create all three sequences again here.
5975 If this does not work for some target, that target should not enable
5976 separate shrink-wrapping. */
5977 if (crtl->shrink_wrapped_separate)
5979 split_prologue_seq = make_split_prologue_seq ();
5980 prologue_seq = make_prologue_seq ();
5981 epilogue_seq = make_epilogue_seq ();
5984 rtl_profile_for_bb (EXIT_BLOCK_PTR_FOR_FN (cfun));
5986 /* A small fib -- epilogue is not yet completed, but we wish to re-use
5987 this marker for the splits of EH_RETURN patterns, and nothing else
5988 uses the flag in the meantime. */
5989 epilogue_completed = 1;
5991 /* Find non-fallthru edges that end with EH_RETURN instructions. On
5992 some targets, these get split to a special version of the epilogue
5993 code. In order to be able to properly annotate these with unwind
5994 info, try to split them now. If we get a valid split, drop an
5995 EPILOGUE_BEG note and mark the insns as epilogue insns. */
5996 edge e;
5997 edge_iterator ei;
5998 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
6000 rtx_insn *prev, *last, *trial;
6002 if (e->flags & EDGE_FALLTHRU)
6003 continue;
6004 last = BB_END (e->src);
6005 if (!eh_returnjump_p (last))
6006 continue;
6008 prev = PREV_INSN (last);
6009 trial = try_split (PATTERN (last), last, 1);
6010 if (trial == last)
6011 continue;
6013 record_insns (NEXT_INSN (prev), NEXT_INSN (trial), &epilogue_insn_hash);
6014 emit_note_after (NOTE_INSN_EPILOGUE_BEG, prev);
6017 edge exit_fallthru_edge = find_fallthru_edge (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds);
6019 if (exit_fallthru_edge)
6021 if (epilogue_seq)
6023 insert_insn_on_edge (epilogue_seq, exit_fallthru_edge);
6024 commit_edge_insertions ();
6026 /* The epilogue insns we inserted may cause the exit edge to no longer
6027 be fallthru. */
6028 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
6030 if (((e->flags & EDGE_FALLTHRU) != 0)
6031 && returnjump_p (BB_END (e->src)))
6032 e->flags &= ~EDGE_FALLTHRU;
6035 else if (next_active_insn (BB_END (exit_fallthru_edge->src)))
6037 /* We have a fall-through edge to the exit block, the source is not
6038 at the end of the function, and there will be an assembler epilogue
6039 at the end of the function.
6040 We can't use force_nonfallthru here, because that would try to
6041 use return. Inserting a jump 'by hand' is extremely messy, so
6042 we take advantage of cfg_layout_finalize using
6043 fixup_fallthru_exit_predecessor. */
6044 cfg_layout_initialize (0);
6045 basic_block cur_bb;
6046 FOR_EACH_BB_FN (cur_bb, cfun)
6047 if (cur_bb->index >= NUM_FIXED_BLOCKS
6048 && cur_bb->next_bb->index >= NUM_FIXED_BLOCKS)
6049 cur_bb->aux = cur_bb->next_bb;
6050 cfg_layout_finalize ();
6054 /* Insert the prologue. */
6056 rtl_profile_for_bb (ENTRY_BLOCK_PTR_FOR_FN (cfun));
6058 if (split_prologue_seq || prologue_seq)
6060 if (split_prologue_seq)
6061 insert_insn_on_edge (split_prologue_seq, orig_entry_edge);
6063 if (prologue_seq)
6064 insert_insn_on_edge (prologue_seq, entry_edge);
6066 commit_edge_insertions ();
6068 /* Look for basic blocks within the prologue insns. */
6069 auto_sbitmap blocks (last_basic_block_for_fn (cfun));
6070 bitmap_clear (blocks);
6071 bitmap_set_bit (blocks, entry_edge->dest->index);
6072 bitmap_set_bit (blocks, orig_entry_edge->dest->index);
6073 find_many_sub_basic_blocks (blocks);
6076 default_rtl_profile ();
6078 /* Emit sibling epilogues before any sibling call sites. */
6079 for (ei = ei_start (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds);
6080 (e = ei_safe_edge (ei));
6081 ei_next (&ei))
6083 /* Skip those already handled, the ones that run without prologue. */
6084 if (e->flags & EDGE_IGNORE)
6086 e->flags &= ~EDGE_IGNORE;
6087 continue;
6090 rtx_insn *insn = BB_END (e->src);
6092 if (!(CALL_P (insn) && SIBLING_CALL_P (insn)))
6093 continue;
6095 if (rtx_insn *ep_seq = targetm.gen_sibcall_epilogue ())
6097 start_sequence ();
6098 emit_note (NOTE_INSN_EPILOGUE_BEG);
6099 emit_insn (ep_seq);
6100 rtx_insn *seq = get_insns ();
6101 end_sequence ();
6103 /* Retain a map of the epilogue insns. Used in life analysis to
6104 avoid getting rid of sibcall epilogue insns. Do this before we
6105 actually emit the sequence. */
6106 record_insns (seq, NULL, &epilogue_insn_hash);
6107 set_insn_locations (seq, epilogue_location);
6109 emit_insn_before (seq, insn);
6113 if (epilogue_seq)
6115 rtx_insn *insn, *next;
6117 /* Similarly, move any line notes that appear after the epilogue.
6118 There is no need, however, to be quite so anal about the existence
6119 of such a note. Also possibly move
6120 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
6121 info generation. */
6122 for (insn = epilogue_seq; insn; insn = next)
6124 next = NEXT_INSN (insn);
6125 if (NOTE_P (insn)
6126 && (NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG))
6127 reorder_insns (insn, insn, PREV_INSN (epilogue_seq));
6131 /* Threading the prologue and epilogue changes the artificial refs
6132 in the entry and exit blocks. */
6133 epilogue_completed = 1;
6134 df_update_entry_exit_and_calls ();
6137 /* Reposition the prologue-end and epilogue-begin notes after
6138 instruction scheduling. */
6140 void
6141 reposition_prologue_and_epilogue_notes (void)
6143 if (!targetm.have_prologue ()
6144 && !targetm.have_epilogue ()
6145 && !targetm.have_sibcall_epilogue ())
6146 return;
6148 /* Since the hash table is created on demand, the fact that it is
6149 non-null is a signal that it is non-empty. */
6150 if (prologue_insn_hash != NULL)
6152 size_t len = prologue_insn_hash->elements ();
6153 rtx_insn *insn, *last = NULL, *note = NULL;
6155 /* Scan from the beginning until we reach the last prologue insn. */
6156 /* ??? While we do have the CFG intact, there are two problems:
6157 (1) The prologue can contain loops (typically probing the stack),
6158 which means that the end of the prologue isn't in the first bb.
6159 (2) Sometimes the PROLOGUE_END note gets pushed into the next bb. */
6160 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
6162 if (NOTE_P (insn))
6164 if (NOTE_KIND (insn) == NOTE_INSN_PROLOGUE_END)
6165 note = insn;
6167 else if (contains (insn, prologue_insn_hash))
6169 last = insn;
6170 if (--len == 0)
6171 break;
6175 if (last)
6177 if (note == NULL)
6179 /* Scan forward looking for the PROLOGUE_END note. It should
6180 be right at the beginning of the block, possibly with other
6181 insn notes that got moved there. */
6182 for (note = NEXT_INSN (last); ; note = NEXT_INSN (note))
6184 if (NOTE_P (note)
6185 && NOTE_KIND (note) == NOTE_INSN_PROLOGUE_END)
6186 break;
6190 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
6191 if (LABEL_P (last))
6192 last = NEXT_INSN (last);
6193 reorder_insns (note, note, last);
6197 if (epilogue_insn_hash != NULL)
6199 edge_iterator ei;
6200 edge e;
6202 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
6204 rtx_insn *insn, *first = NULL, *note = NULL;
6205 basic_block bb = e->src;
6207 /* Scan from the beginning until we reach the first epilogue insn. */
6208 FOR_BB_INSNS (bb, insn)
6210 if (NOTE_P (insn))
6212 if (NOTE_KIND (insn) == NOTE_INSN_EPILOGUE_BEG)
6214 note = insn;
6215 if (first != NULL)
6216 break;
6219 else if (first == NULL && contains (insn, epilogue_insn_hash))
6221 first = insn;
6222 if (note != NULL)
6223 break;
6227 if (note)
6229 /* If the function has a single basic block, and no real
6230 epilogue insns (e.g. sibcall with no cleanup), the
6231 epilogue note can get scheduled before the prologue
6232 note. If we have frame related prologue insns, having
6233 them scanned during the epilogue will result in a crash.
6234 In this case re-order the epilogue note to just before
6235 the last insn in the block. */
6236 if (first == NULL)
6237 first = BB_END (bb);
6239 if (PREV_INSN (first) != note)
6240 reorder_insns (note, note, PREV_INSN (first));
6246 /* Returns the name of function declared by FNDECL. */
6247 const char *
6248 fndecl_name (tree fndecl)
6250 if (fndecl == NULL)
6251 return "(nofn)";
6252 return lang_hooks.decl_printable_name (fndecl, 2);
6255 /* Returns the name of function FN. */
6256 const char *
6257 function_name (struct function *fn)
6259 tree fndecl = (fn == NULL) ? NULL : fn->decl;
6260 return fndecl_name (fndecl);
6263 /* Returns the name of the current function. */
6264 const char *
6265 current_function_name (void)
6267 return function_name (cfun);
6271 static unsigned int
6272 rest_of_handle_check_leaf_regs (void)
6274 #ifdef LEAF_REGISTERS
6275 crtl->uses_only_leaf_regs
6276 = optimize > 0 && only_leaf_regs_used () && leaf_function_p ();
6277 #endif
6278 return 0;
6281 /* Insert a TYPE into the used types hash table of CFUN. */
6283 static void
6284 used_types_insert_helper (tree type, struct function *func)
6286 if (type != NULL && func != NULL)
6288 if (func->used_types_hash == NULL)
6289 func->used_types_hash = hash_set<tree>::create_ggc (37);
6291 func->used_types_hash->add (type);
6295 /* Given a type, insert it into the used hash table in cfun. */
6296 void
6297 used_types_insert (tree t)
6299 while (POINTER_TYPE_P (t) || TREE_CODE (t) == ARRAY_TYPE)
6300 if (TYPE_NAME (t))
6301 break;
6302 else
6303 t = TREE_TYPE (t);
6304 if (TREE_CODE (t) == ERROR_MARK)
6305 return;
6306 if (TYPE_NAME (t) == NULL_TREE
6307 || TYPE_NAME (t) == TYPE_NAME (TYPE_MAIN_VARIANT (t)))
6308 t = TYPE_MAIN_VARIANT (t);
6309 if (debug_info_level > DINFO_LEVEL_NONE)
6311 if (cfun)
6312 used_types_insert_helper (t, cfun);
6313 else
6315 /* So this might be a type referenced by a global variable.
6316 Record that type so that we can later decide to emit its
6317 debug information. */
6318 vec_safe_push (types_used_by_cur_var_decl, t);
6323 /* Helper to Hash a struct types_used_by_vars_entry. */
6325 static hashval_t
6326 hash_types_used_by_vars_entry (const struct types_used_by_vars_entry *entry)
6328 gcc_assert (entry && entry->var_decl && entry->type);
6330 return iterative_hash_object (entry->type,
6331 iterative_hash_object (entry->var_decl, 0));
6334 /* Hash function of the types_used_by_vars_entry hash table. */
6336 hashval_t
6337 used_type_hasher::hash (types_used_by_vars_entry *entry)
6339 return hash_types_used_by_vars_entry (entry);
6342 /*Equality function of the types_used_by_vars_entry hash table. */
6344 bool
6345 used_type_hasher::equal (types_used_by_vars_entry *e1,
6346 types_used_by_vars_entry *e2)
6348 return (e1->var_decl == e2->var_decl && e1->type == e2->type);
6351 /* Inserts an entry into the types_used_by_vars_hash hash table. */
6353 void
6354 types_used_by_var_decl_insert (tree type, tree var_decl)
6356 if (type != NULL && var_decl != NULL)
6358 types_used_by_vars_entry **slot;
6359 struct types_used_by_vars_entry e;
6360 e.var_decl = var_decl;
6361 e.type = type;
6362 if (types_used_by_vars_hash == NULL)
6363 types_used_by_vars_hash
6364 = hash_table<used_type_hasher>::create_ggc (37);
6366 slot = types_used_by_vars_hash->find_slot (&e, INSERT);
6367 if (*slot == NULL)
6369 struct types_used_by_vars_entry *entry;
6370 entry = ggc_alloc<types_used_by_vars_entry> ();
6371 entry->type = type;
6372 entry->var_decl = var_decl;
6373 *slot = entry;
6378 namespace {
6380 const pass_data pass_data_leaf_regs =
6382 RTL_PASS, /* type */
6383 "*leaf_regs", /* name */
6384 OPTGROUP_NONE, /* optinfo_flags */
6385 TV_NONE, /* tv_id */
6386 0, /* properties_required */
6387 0, /* properties_provided */
6388 0, /* properties_destroyed */
6389 0, /* todo_flags_start */
6390 0, /* todo_flags_finish */
6393 class pass_leaf_regs : public rtl_opt_pass
6395 public:
6396 pass_leaf_regs (gcc::context *ctxt)
6397 : rtl_opt_pass (pass_data_leaf_regs, ctxt)
6400 /* opt_pass methods: */
6401 virtual unsigned int execute (function *)
6403 return rest_of_handle_check_leaf_regs ();
6406 }; // class pass_leaf_regs
6408 } // anon namespace
6410 rtl_opt_pass *
6411 make_pass_leaf_regs (gcc::context *ctxt)
6413 return new pass_leaf_regs (ctxt);
6416 static unsigned int
6417 rest_of_handle_thread_prologue_and_epilogue (void)
6419 /* prepare_shrink_wrap is sensitive to the block structure of the control
6420 flow graph, so clean it up first. */
6421 if (optimize)
6422 cleanup_cfg (0);
6424 /* On some machines, the prologue and epilogue code, or parts thereof,
6425 can be represented as RTL. Doing so lets us schedule insns between
6426 it and the rest of the code and also allows delayed branch
6427 scheduling to operate in the epilogue. */
6428 thread_prologue_and_epilogue_insns ();
6430 /* Some non-cold blocks may now be only reachable from cold blocks.
6431 Fix that up. */
6432 fixup_partitions ();
6434 /* Shrink-wrapping can result in unreachable edges in the epilogue,
6435 see PR57320. */
6436 cleanup_cfg (optimize ? CLEANUP_EXPENSIVE : 0);
6438 /* The stack usage info is finalized during prologue expansion. */
6439 if (flag_stack_usage_info)
6440 output_stack_usage ();
6442 return 0;
6445 namespace {
6447 const pass_data pass_data_thread_prologue_and_epilogue =
6449 RTL_PASS, /* type */
6450 "pro_and_epilogue", /* name */
6451 OPTGROUP_NONE, /* optinfo_flags */
6452 TV_THREAD_PROLOGUE_AND_EPILOGUE, /* tv_id */
6453 0, /* properties_required */
6454 0, /* properties_provided */
6455 0, /* properties_destroyed */
6456 0, /* todo_flags_start */
6457 ( TODO_df_verify | TODO_df_finish ), /* todo_flags_finish */
6460 class pass_thread_prologue_and_epilogue : public rtl_opt_pass
6462 public:
6463 pass_thread_prologue_and_epilogue (gcc::context *ctxt)
6464 : rtl_opt_pass (pass_data_thread_prologue_and_epilogue, ctxt)
6467 /* opt_pass methods: */
6468 virtual unsigned int execute (function *)
6470 return rest_of_handle_thread_prologue_and_epilogue ();
6473 }; // class pass_thread_prologue_and_epilogue
6475 } // anon namespace
6477 rtl_opt_pass *
6478 make_pass_thread_prologue_and_epilogue (gcc::context *ctxt)
6480 return new pass_thread_prologue_and_epilogue (ctxt);
6484 /* This mini-pass fixes fall-out from SSA in asm statements that have
6485 in-out constraints. Say you start with
6487 orig = inout;
6488 asm ("": "+mr" (inout));
6489 use (orig);
6491 which is transformed very early to use explicit output and match operands:
6493 orig = inout;
6494 asm ("": "=mr" (inout) : "0" (inout));
6495 use (orig);
6497 Or, after SSA and copyprop,
6499 asm ("": "=mr" (inout_2) : "0" (inout_1));
6500 use (inout_1);
6502 Clearly inout_2 and inout_1 can't be coalesced easily anymore, as
6503 they represent two separate values, so they will get different pseudo
6504 registers during expansion. Then, since the two operands need to match
6505 per the constraints, but use different pseudo registers, reload can
6506 only register a reload for these operands. But reloads can only be
6507 satisfied by hardregs, not by memory, so we need a register for this
6508 reload, just because we are presented with non-matching operands.
6509 So, even though we allow memory for this operand, no memory can be
6510 used for it, just because the two operands don't match. This can
6511 cause reload failures on register-starved targets.
6513 So it's a symptom of reload not being able to use memory for reloads
6514 or, alternatively it's also a symptom of both operands not coming into
6515 reload as matching (in which case the pseudo could go to memory just
6516 fine, as the alternative allows it, and no reload would be necessary).
6517 We fix the latter problem here, by transforming
6519 asm ("": "=mr" (inout_2) : "0" (inout_1));
6521 back to
6523 inout_2 = inout_1;
6524 asm ("": "=mr" (inout_2) : "0" (inout_2)); */
6526 static void
6527 match_asm_constraints_1 (rtx_insn *insn, rtx *p_sets, int noutputs)
6529 int i;
6530 bool changed = false;
6531 rtx op = SET_SRC (p_sets[0]);
6532 int ninputs = ASM_OPERANDS_INPUT_LENGTH (op);
6533 rtvec inputs = ASM_OPERANDS_INPUT_VEC (op);
6534 bool *output_matched = XALLOCAVEC (bool, noutputs);
6536 memset (output_matched, 0, noutputs * sizeof (bool));
6537 for (i = 0; i < ninputs; i++)
6539 rtx input, output;
6540 rtx_insn *insns;
6541 const char *constraint = ASM_OPERANDS_INPUT_CONSTRAINT (op, i);
6542 char *end;
6543 int match, j;
6545 if (*constraint == '%')
6546 constraint++;
6548 match = strtoul (constraint, &end, 10);
6549 if (end == constraint)
6550 continue;
6552 gcc_assert (match < noutputs);
6553 output = SET_DEST (p_sets[match]);
6554 input = RTVEC_ELT (inputs, i);
6555 /* Only do the transformation for pseudos. */
6556 if (! REG_P (output)
6557 || rtx_equal_p (output, input)
6558 || (GET_MODE (input) != VOIDmode
6559 && GET_MODE (input) != GET_MODE (output)))
6560 continue;
6562 /* We can't do anything if the output is also used as input,
6563 as we're going to overwrite it. */
6564 for (j = 0; j < ninputs; j++)
6565 if (reg_overlap_mentioned_p (output, RTVEC_ELT (inputs, j)))
6566 break;
6567 if (j != ninputs)
6568 continue;
6570 /* Avoid changing the same input several times. For
6571 asm ("" : "=mr" (out1), "=mr" (out2) : "0" (in), "1" (in));
6572 only change in once (to out1), rather than changing it
6573 first to out1 and afterwards to out2. */
6574 if (i > 0)
6576 for (j = 0; j < noutputs; j++)
6577 if (output_matched[j] && input == SET_DEST (p_sets[j]))
6578 break;
6579 if (j != noutputs)
6580 continue;
6582 output_matched[match] = true;
6584 start_sequence ();
6585 emit_move_insn (output, input);
6586 insns = get_insns ();
6587 end_sequence ();
6588 emit_insn_before (insns, insn);
6590 /* Now replace all mentions of the input with output. We can't
6591 just replace the occurrence in inputs[i], as the register might
6592 also be used in some other input (or even in an address of an
6593 output), which would mean possibly increasing the number of
6594 inputs by one (namely 'output' in addition), which might pose
6595 a too complicated problem for reload to solve. E.g. this situation:
6597 asm ("" : "=r" (output), "=m" (input) : "0" (input))
6599 Here 'input' is used in two occurrences as input (once for the
6600 input operand, once for the address in the second output operand).
6601 If we would replace only the occurrence of the input operand (to
6602 make the matching) we would be left with this:
6604 output = input
6605 asm ("" : "=r" (output), "=m" (input) : "0" (output))
6607 Now we suddenly have two different input values (containing the same
6608 value, but different pseudos) where we formerly had only one.
6609 With more complicated asms this might lead to reload failures
6610 which wouldn't have happen without this pass. So, iterate over
6611 all operands and replace all occurrences of the register used. */
6612 for (j = 0; j < noutputs; j++)
6613 if (!rtx_equal_p (SET_DEST (p_sets[j]), input)
6614 && reg_overlap_mentioned_p (input, SET_DEST (p_sets[j])))
6615 SET_DEST (p_sets[j]) = replace_rtx (SET_DEST (p_sets[j]),
6616 input, output);
6617 for (j = 0; j < ninputs; j++)
6618 if (reg_overlap_mentioned_p (input, RTVEC_ELT (inputs, j)))
6619 RTVEC_ELT (inputs, j) = replace_rtx (RTVEC_ELT (inputs, j),
6620 input, output);
6622 changed = true;
6625 if (changed)
6626 df_insn_rescan (insn);
6629 /* Add the decl D to the local_decls list of FUN. */
6631 void
6632 add_local_decl (struct function *fun, tree d)
6634 gcc_assert (VAR_P (d));
6635 vec_safe_push (fun->local_decls, d);
6638 namespace {
6640 const pass_data pass_data_match_asm_constraints =
6642 RTL_PASS, /* type */
6643 "asmcons", /* name */
6644 OPTGROUP_NONE, /* optinfo_flags */
6645 TV_NONE, /* tv_id */
6646 0, /* properties_required */
6647 0, /* properties_provided */
6648 0, /* properties_destroyed */
6649 0, /* todo_flags_start */
6650 0, /* todo_flags_finish */
6653 class pass_match_asm_constraints : public rtl_opt_pass
6655 public:
6656 pass_match_asm_constraints (gcc::context *ctxt)
6657 : rtl_opt_pass (pass_data_match_asm_constraints, ctxt)
6660 /* opt_pass methods: */
6661 virtual unsigned int execute (function *);
6663 }; // class pass_match_asm_constraints
6665 unsigned
6666 pass_match_asm_constraints::execute (function *fun)
6668 basic_block bb;
6669 rtx_insn *insn;
6670 rtx pat, *p_sets;
6671 int noutputs;
6673 if (!crtl->has_asm_statement)
6674 return 0;
6676 df_set_flags (DF_DEFER_INSN_RESCAN);
6677 FOR_EACH_BB_FN (bb, fun)
6679 FOR_BB_INSNS (bb, insn)
6681 if (!INSN_P (insn))
6682 continue;
6684 pat = PATTERN (insn);
6685 if (GET_CODE (pat) == PARALLEL)
6686 p_sets = &XVECEXP (pat, 0, 0), noutputs = XVECLEN (pat, 0);
6687 else if (GET_CODE (pat) == SET)
6688 p_sets = &PATTERN (insn), noutputs = 1;
6689 else
6690 continue;
6692 if (GET_CODE (*p_sets) == SET
6693 && GET_CODE (SET_SRC (*p_sets)) == ASM_OPERANDS)
6694 match_asm_constraints_1 (insn, p_sets, noutputs);
6698 return TODO_df_finish;
6701 } // anon namespace
6703 rtl_opt_pass *
6704 make_pass_match_asm_constraints (gcc::context *ctxt)
6706 return new pass_match_asm_constraints (ctxt);
6710 #include "gt-function.h"