New VECTOR_CST layout
[official-gcc.git] / gcc / function.c
blob1fa538b4b7fd21a9a4fd40d8e9a21cf81fed95b1
1 /* Expands front end tree to back end RTL for GCC.
2 Copyright (C) 1987-2017 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 for more details.
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
20 /* This file handles the generation of rtl code from tree structure
21 at the level of the function as a whole.
22 It creates the rtl expressions for parameters and auto variables
23 and has full responsibility for allocating stack slots.
25 `expand_function_start' is called at the beginning of a function,
26 before the function body is parsed, and `expand_function_end' is
27 called after parsing the body.
29 Call `assign_stack_local' to allocate a stack slot for a local variable.
30 This is usually done during the RTL generation for the function body,
31 but it can also be done in the reload pass when a pseudo-register does
32 not get a hard register. */
34 #include "config.h"
35 #include "system.h"
36 #include "coretypes.h"
37 #include "backend.h"
38 #include "target.h"
39 #include "rtl.h"
40 #include "tree.h"
41 #include "gimple-expr.h"
42 #include "cfghooks.h"
43 #include "df.h"
44 #include "memmodel.h"
45 #include "tm_p.h"
46 #include "stringpool.h"
47 #include "expmed.h"
48 #include "optabs.h"
49 #include "regs.h"
50 #include "emit-rtl.h"
51 #include "recog.h"
52 #include "rtl-error.h"
53 #include "alias.h"
54 #include "fold-const.h"
55 #include "stor-layout.h"
56 #include "varasm.h"
57 #include "except.h"
58 #include "dojump.h"
59 #include "explow.h"
60 #include "calls.h"
61 #include "expr.h"
62 #include "optabs-tree.h"
63 #include "output.h"
64 #include "langhooks.h"
65 #include "common/common-target.h"
66 #include "gimplify.h"
67 #include "tree-pass.h"
68 #include "cfgrtl.h"
69 #include "cfganal.h"
70 #include "cfgbuild.h"
71 #include "cfgcleanup.h"
72 #include "cfgexpand.h"
73 #include "shrink-wrap.h"
74 #include "toplev.h"
75 #include "rtl-iter.h"
76 #include "tree-chkp.h"
77 #include "rtl-chkp.h"
78 #include "tree-dfa.h"
79 #include "tree-ssa.h"
80 #include "stringpool.h"
81 #include "attribs.h"
83 /* So we can assign to cfun in this file. */
84 #undef cfun
86 #ifndef STACK_ALIGNMENT_NEEDED
87 #define STACK_ALIGNMENT_NEEDED 1
88 #endif
90 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
92 /* Round a value to the lowest integer less than it that is a multiple of
93 the required alignment. Avoid using division in case the value is
94 negative. Assume the alignment is a power of two. */
95 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
97 /* Similar, but round to the next highest integer that meets the
98 alignment. */
99 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
101 /* Nonzero once virtual register instantiation has been done.
102 assign_stack_local uses frame_pointer_rtx when this is nonzero.
103 calls.c:emit_library_call_value_1 uses it to set up
104 post-instantiation libcalls. */
105 int virtuals_instantiated;
107 /* Assign unique numbers to labels generated for profiling, debugging, etc. */
108 static GTY(()) int funcdef_no;
110 /* These variables hold pointers to functions to create and destroy
111 target specific, per-function data structures. */
112 struct machine_function * (*init_machine_status) (void);
114 /* The currently compiled function. */
115 struct function *cfun = 0;
117 /* These hashes record the prologue and epilogue insns. */
119 struct insn_cache_hasher : ggc_cache_ptr_hash<rtx_def>
121 static hashval_t hash (rtx x) { return htab_hash_pointer (x); }
122 static bool equal (rtx a, rtx b) { return a == b; }
125 static GTY((cache))
126 hash_table<insn_cache_hasher> *prologue_insn_hash;
127 static GTY((cache))
128 hash_table<insn_cache_hasher> *epilogue_insn_hash;
131 hash_table<used_type_hasher> *types_used_by_vars_hash = NULL;
132 vec<tree, va_gc> *types_used_by_cur_var_decl;
134 /* Forward declarations. */
136 static struct temp_slot *find_temp_slot_from_address (rtx);
137 static void pad_to_arg_alignment (struct args_size *, int, struct args_size *);
138 static void pad_below (struct args_size *, machine_mode, tree);
139 static void reorder_blocks_1 (rtx_insn *, tree, vec<tree> *);
140 static int all_blocks (tree, tree *);
141 static tree *get_block_vector (tree, int *);
142 extern tree debug_find_var_in_block_tree (tree, tree);
143 /* We always define `record_insns' even if it's not used so that we
144 can always export `prologue_epilogue_contains'. */
145 static void record_insns (rtx_insn *, rtx, hash_table<insn_cache_hasher> **)
146 ATTRIBUTE_UNUSED;
147 static bool contains (const rtx_insn *, hash_table<insn_cache_hasher> *);
148 static void prepare_function_start (void);
149 static void do_clobber_return_reg (rtx, void *);
150 static void do_use_return_reg (rtx, void *);
153 /* Stack of nested functions. */
154 /* Keep track of the cfun stack. */
156 static vec<function *> function_context_stack;
158 /* Save the current context for compilation of a nested function.
159 This is called from language-specific code. */
161 void
162 push_function_context (void)
164 if (cfun == 0)
165 allocate_struct_function (NULL, false);
167 function_context_stack.safe_push (cfun);
168 set_cfun (NULL);
171 /* Restore the last saved context, at the end of a nested function.
172 This function is called from language-specific code. */
174 void
175 pop_function_context (void)
177 struct function *p = function_context_stack.pop ();
178 set_cfun (p);
179 current_function_decl = p->decl;
181 /* Reset variables that have known state during rtx generation. */
182 virtuals_instantiated = 0;
183 generating_concat_p = 1;
186 /* Clear out all parts of the state in F that can safely be discarded
187 after the function has been parsed, but not compiled, to let
188 garbage collection reclaim the memory. */
190 void
191 free_after_parsing (struct function *f)
193 f->language = 0;
196 /* Clear out all parts of the state in F that can safely be discarded
197 after the function has been compiled, to let garbage collection
198 reclaim the memory. */
200 void
201 free_after_compilation (struct function *f)
203 prologue_insn_hash = NULL;
204 epilogue_insn_hash = NULL;
206 free (crtl->emit.regno_pointer_align);
208 memset (crtl, 0, sizeof (struct rtl_data));
209 f->eh = NULL;
210 f->machine = NULL;
211 f->cfg = NULL;
212 f->curr_properties &= ~PROP_cfg;
214 regno_reg_rtx = NULL;
217 /* Return size needed for stack frame based on slots so far allocated.
218 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
219 the caller may have to do that. */
221 HOST_WIDE_INT
222 get_frame_size (void)
224 if (FRAME_GROWS_DOWNWARD)
225 return -frame_offset;
226 else
227 return frame_offset;
230 /* Issue an error message and return TRUE if frame OFFSET overflows in
231 the signed target pointer arithmetics for function FUNC. Otherwise
232 return FALSE. */
234 bool
235 frame_offset_overflow (HOST_WIDE_INT offset, tree func)
237 unsigned HOST_WIDE_INT size = FRAME_GROWS_DOWNWARD ? -offset : offset;
239 if (size > (HOST_WIDE_INT_1U << (GET_MODE_BITSIZE (Pmode) - 1))
240 /* Leave room for the fixed part of the frame. */
241 - 64 * UNITS_PER_WORD)
243 error_at (DECL_SOURCE_LOCATION (func),
244 "total size of local objects too large");
245 return TRUE;
248 return FALSE;
251 /* Return the minimum spill slot alignment for a register of mode MODE. */
253 unsigned int
254 spill_slot_alignment (machine_mode mode ATTRIBUTE_UNUSED)
256 return STACK_SLOT_ALIGNMENT (NULL_TREE, mode, GET_MODE_ALIGNMENT (mode));
259 /* Return stack slot alignment in bits for TYPE and MODE. */
261 static unsigned int
262 get_stack_local_alignment (tree type, machine_mode mode)
264 unsigned int alignment;
266 if (mode == BLKmode)
267 alignment = BIGGEST_ALIGNMENT;
268 else
269 alignment = GET_MODE_ALIGNMENT (mode);
271 /* Allow the frond-end to (possibly) increase the alignment of this
272 stack slot. */
273 if (! type)
274 type = lang_hooks.types.type_for_mode (mode, 0);
276 return STACK_SLOT_ALIGNMENT (type, mode, alignment);
279 /* Determine whether it is possible to fit a stack slot of size SIZE and
280 alignment ALIGNMENT into an area in the stack frame that starts at
281 frame offset START and has a length of LENGTH. If so, store the frame
282 offset to be used for the stack slot in *POFFSET and return true;
283 return false otherwise. This function will extend the frame size when
284 given a start/length pair that lies at the end of the frame. */
286 static bool
287 try_fit_stack_local (HOST_WIDE_INT start, HOST_WIDE_INT length,
288 HOST_WIDE_INT size, unsigned int alignment,
289 HOST_WIDE_INT *poffset)
291 HOST_WIDE_INT this_frame_offset;
292 int frame_off, frame_alignment, frame_phase;
294 /* Calculate how many bytes the start of local variables is off from
295 stack alignment. */
296 frame_alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
297 frame_off = targetm.starting_frame_offset () % frame_alignment;
298 frame_phase = frame_off ? frame_alignment - frame_off : 0;
300 /* Round the frame offset to the specified alignment. */
302 /* We must be careful here, since FRAME_OFFSET might be negative and
303 division with a negative dividend isn't as well defined as we might
304 like. So we instead assume that ALIGNMENT is a power of two and
305 use logical operations which are unambiguous. */
306 if (FRAME_GROWS_DOWNWARD)
307 this_frame_offset
308 = (FLOOR_ROUND (start + length - size - frame_phase,
309 (unsigned HOST_WIDE_INT) alignment)
310 + frame_phase);
311 else
312 this_frame_offset
313 = (CEIL_ROUND (start - frame_phase,
314 (unsigned HOST_WIDE_INT) alignment)
315 + frame_phase);
317 /* See if it fits. If this space is at the edge of the frame,
318 consider extending the frame to make it fit. Our caller relies on
319 this when allocating a new slot. */
320 if (frame_offset == start && this_frame_offset < frame_offset)
321 frame_offset = this_frame_offset;
322 else if (this_frame_offset < start)
323 return false;
324 else if (start + length == frame_offset
325 && this_frame_offset + size > start + length)
326 frame_offset = this_frame_offset + size;
327 else if (this_frame_offset + size > start + length)
328 return false;
330 *poffset = this_frame_offset;
331 return true;
334 /* Create a new frame_space structure describing free space in the stack
335 frame beginning at START and ending at END, and chain it into the
336 function's frame_space_list. */
338 static void
339 add_frame_space (HOST_WIDE_INT start, HOST_WIDE_INT end)
341 struct frame_space *space = ggc_alloc<frame_space> ();
342 space->next = crtl->frame_space_list;
343 crtl->frame_space_list = space;
344 space->start = start;
345 space->length = end - start;
348 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
349 with machine mode MODE.
351 ALIGN controls the amount of alignment for the address of the slot:
352 0 means according to MODE,
353 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
354 -2 means use BITS_PER_UNIT,
355 positive specifies alignment boundary in bits.
357 KIND has ASLK_REDUCE_ALIGN bit set if it is OK to reduce
358 alignment and ASLK_RECORD_PAD bit set if we should remember
359 extra space we allocated for alignment purposes. When we are
360 called from assign_stack_temp_for_type, it is not set so we don't
361 track the same stack slot in two independent lists.
363 We do not round to stack_boundary here. */
366 assign_stack_local_1 (machine_mode mode, HOST_WIDE_INT size,
367 int align, int kind)
369 rtx x, addr;
370 int bigend_correction = 0;
371 HOST_WIDE_INT slot_offset = 0, old_frame_offset;
372 unsigned int alignment, alignment_in_bits;
374 if (align == 0)
376 alignment = get_stack_local_alignment (NULL, mode);
377 alignment /= BITS_PER_UNIT;
379 else if (align == -1)
381 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
382 size = CEIL_ROUND (size, alignment);
384 else if (align == -2)
385 alignment = 1; /* BITS_PER_UNIT / BITS_PER_UNIT */
386 else
387 alignment = align / BITS_PER_UNIT;
389 alignment_in_bits = alignment * BITS_PER_UNIT;
391 /* Ignore alignment if it exceeds MAX_SUPPORTED_STACK_ALIGNMENT. */
392 if (alignment_in_bits > MAX_SUPPORTED_STACK_ALIGNMENT)
394 alignment_in_bits = MAX_SUPPORTED_STACK_ALIGNMENT;
395 alignment = alignment_in_bits / BITS_PER_UNIT;
398 if (SUPPORTS_STACK_ALIGNMENT)
400 if (crtl->stack_alignment_estimated < alignment_in_bits)
402 if (!crtl->stack_realign_processed)
403 crtl->stack_alignment_estimated = alignment_in_bits;
404 else
406 /* If stack is realigned and stack alignment value
407 hasn't been finalized, it is OK not to increase
408 stack_alignment_estimated. The bigger alignment
409 requirement is recorded in stack_alignment_needed
410 below. */
411 gcc_assert (!crtl->stack_realign_finalized);
412 if (!crtl->stack_realign_needed)
414 /* It is OK to reduce the alignment as long as the
415 requested size is 0 or the estimated stack
416 alignment >= mode alignment. */
417 gcc_assert ((kind & ASLK_REDUCE_ALIGN)
418 || size == 0
419 || (crtl->stack_alignment_estimated
420 >= GET_MODE_ALIGNMENT (mode)));
421 alignment_in_bits = crtl->stack_alignment_estimated;
422 alignment = alignment_in_bits / BITS_PER_UNIT;
428 if (crtl->stack_alignment_needed < alignment_in_bits)
429 crtl->stack_alignment_needed = alignment_in_bits;
430 if (crtl->max_used_stack_slot_alignment < alignment_in_bits)
431 crtl->max_used_stack_slot_alignment = alignment_in_bits;
433 if (mode != BLKmode || size != 0)
435 if (kind & ASLK_RECORD_PAD)
437 struct frame_space **psp;
439 for (psp = &crtl->frame_space_list; *psp; psp = &(*psp)->next)
441 struct frame_space *space = *psp;
442 if (!try_fit_stack_local (space->start, space->length, size,
443 alignment, &slot_offset))
444 continue;
445 *psp = space->next;
446 if (slot_offset > space->start)
447 add_frame_space (space->start, slot_offset);
448 if (slot_offset + size < space->start + space->length)
449 add_frame_space (slot_offset + size,
450 space->start + space->length);
451 goto found_space;
455 else if (!STACK_ALIGNMENT_NEEDED)
457 slot_offset = frame_offset;
458 goto found_space;
461 old_frame_offset = frame_offset;
463 if (FRAME_GROWS_DOWNWARD)
465 frame_offset -= size;
466 try_fit_stack_local (frame_offset, size, size, alignment, &slot_offset);
468 if (kind & ASLK_RECORD_PAD)
470 if (slot_offset > frame_offset)
471 add_frame_space (frame_offset, slot_offset);
472 if (slot_offset + size < old_frame_offset)
473 add_frame_space (slot_offset + size, old_frame_offset);
476 else
478 frame_offset += size;
479 try_fit_stack_local (old_frame_offset, size, size, alignment, &slot_offset);
481 if (kind & ASLK_RECORD_PAD)
483 if (slot_offset > old_frame_offset)
484 add_frame_space (old_frame_offset, slot_offset);
485 if (slot_offset + size < frame_offset)
486 add_frame_space (slot_offset + size, frame_offset);
490 found_space:
491 /* On a big-endian machine, if we are allocating more space than we will use,
492 use the least significant bytes of those that are allocated. */
493 if (BYTES_BIG_ENDIAN && mode != BLKmode && GET_MODE_SIZE (mode) < size)
494 bigend_correction = size - GET_MODE_SIZE (mode);
496 /* If we have already instantiated virtual registers, return the actual
497 address relative to the frame pointer. */
498 if (virtuals_instantiated)
499 addr = plus_constant (Pmode, frame_pointer_rtx,
500 trunc_int_for_mode
501 (slot_offset + bigend_correction
502 + targetm.starting_frame_offset (), Pmode));
503 else
504 addr = plus_constant (Pmode, virtual_stack_vars_rtx,
505 trunc_int_for_mode
506 (slot_offset + bigend_correction,
507 Pmode));
509 x = gen_rtx_MEM (mode, addr);
510 set_mem_align (x, alignment_in_bits);
511 MEM_NOTRAP_P (x) = 1;
513 vec_safe_push (stack_slot_list, x);
515 if (frame_offset_overflow (frame_offset, current_function_decl))
516 frame_offset = 0;
518 return x;
521 /* Wrap up assign_stack_local_1 with last parameter as false. */
524 assign_stack_local (machine_mode mode, HOST_WIDE_INT size, int align)
526 return assign_stack_local_1 (mode, size, align, ASLK_RECORD_PAD);
529 /* In order to evaluate some expressions, such as function calls returning
530 structures in memory, we need to temporarily allocate stack locations.
531 We record each allocated temporary in the following structure.
533 Associated with each temporary slot is a nesting level. When we pop up
534 one level, all temporaries associated with the previous level are freed.
535 Normally, all temporaries are freed after the execution of the statement
536 in which they were created. However, if we are inside a ({...}) grouping,
537 the result may be in a temporary and hence must be preserved. If the
538 result could be in a temporary, we preserve it if we can determine which
539 one it is in. If we cannot determine which temporary may contain the
540 result, all temporaries are preserved. A temporary is preserved by
541 pretending it was allocated at the previous nesting level. */
543 struct GTY(()) temp_slot {
544 /* Points to next temporary slot. */
545 struct temp_slot *next;
546 /* Points to previous temporary slot. */
547 struct temp_slot *prev;
548 /* The rtx to used to reference the slot. */
549 rtx slot;
550 /* The size, in units, of the slot. */
551 HOST_WIDE_INT size;
552 /* The type of the object in the slot, or zero if it doesn't correspond
553 to a type. We use this to determine whether a slot can be reused.
554 It can be reused if objects of the type of the new slot will always
555 conflict with objects of the type of the old slot. */
556 tree type;
557 /* The alignment (in bits) of the slot. */
558 unsigned int align;
559 /* Nonzero if this temporary is currently in use. */
560 char in_use;
561 /* Nesting level at which this slot is being used. */
562 int level;
563 /* The offset of the slot from the frame_pointer, including extra space
564 for alignment. This info is for combine_temp_slots. */
565 HOST_WIDE_INT base_offset;
566 /* The size of the slot, including extra space for alignment. This
567 info is for combine_temp_slots. */
568 HOST_WIDE_INT full_size;
571 /* Entry for the below hash table. */
572 struct GTY((for_user)) temp_slot_address_entry {
573 hashval_t hash;
574 rtx address;
575 struct temp_slot *temp_slot;
578 struct temp_address_hasher : ggc_ptr_hash<temp_slot_address_entry>
580 static hashval_t hash (temp_slot_address_entry *);
581 static bool equal (temp_slot_address_entry *, temp_slot_address_entry *);
584 /* A table of addresses that represent a stack slot. The table is a mapping
585 from address RTXen to a temp slot. */
586 static GTY(()) hash_table<temp_address_hasher> *temp_slot_address_table;
587 static size_t n_temp_slots_in_use;
589 /* Removes temporary slot TEMP from LIST. */
591 static void
592 cut_slot_from_list (struct temp_slot *temp, struct temp_slot **list)
594 if (temp->next)
595 temp->next->prev = temp->prev;
596 if (temp->prev)
597 temp->prev->next = temp->next;
598 else
599 *list = temp->next;
601 temp->prev = temp->next = NULL;
604 /* Inserts temporary slot TEMP to LIST. */
606 static void
607 insert_slot_to_list (struct temp_slot *temp, struct temp_slot **list)
609 temp->next = *list;
610 if (*list)
611 (*list)->prev = temp;
612 temp->prev = NULL;
613 *list = temp;
616 /* Returns the list of used temp slots at LEVEL. */
618 static struct temp_slot **
619 temp_slots_at_level (int level)
621 if (level >= (int) vec_safe_length (used_temp_slots))
622 vec_safe_grow_cleared (used_temp_slots, level + 1);
624 return &(*used_temp_slots)[level];
627 /* Returns the maximal temporary slot level. */
629 static int
630 max_slot_level (void)
632 if (!used_temp_slots)
633 return -1;
635 return used_temp_slots->length () - 1;
638 /* Moves temporary slot TEMP to LEVEL. */
640 static void
641 move_slot_to_level (struct temp_slot *temp, int level)
643 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
644 insert_slot_to_list (temp, temp_slots_at_level (level));
645 temp->level = level;
648 /* Make temporary slot TEMP available. */
650 static void
651 make_slot_available (struct temp_slot *temp)
653 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
654 insert_slot_to_list (temp, &avail_temp_slots);
655 temp->in_use = 0;
656 temp->level = -1;
657 n_temp_slots_in_use--;
660 /* Compute the hash value for an address -> temp slot mapping.
661 The value is cached on the mapping entry. */
662 static hashval_t
663 temp_slot_address_compute_hash (struct temp_slot_address_entry *t)
665 int do_not_record = 0;
666 return hash_rtx (t->address, GET_MODE (t->address),
667 &do_not_record, NULL, false);
670 /* Return the hash value for an address -> temp slot mapping. */
671 hashval_t
672 temp_address_hasher::hash (temp_slot_address_entry *t)
674 return t->hash;
677 /* Compare two address -> temp slot mapping entries. */
678 bool
679 temp_address_hasher::equal (temp_slot_address_entry *t1,
680 temp_slot_address_entry *t2)
682 return exp_equiv_p (t1->address, t2->address, 0, true);
685 /* Add ADDRESS as an alias of TEMP_SLOT to the addess -> temp slot mapping. */
686 static void
687 insert_temp_slot_address (rtx address, struct temp_slot *temp_slot)
689 struct temp_slot_address_entry *t = ggc_alloc<temp_slot_address_entry> ();
690 t->address = address;
691 t->temp_slot = temp_slot;
692 t->hash = temp_slot_address_compute_hash (t);
693 *temp_slot_address_table->find_slot_with_hash (t, t->hash, INSERT) = t;
696 /* Remove an address -> temp slot mapping entry if the temp slot is
697 not in use anymore. Callback for remove_unused_temp_slot_addresses. */
699 remove_unused_temp_slot_addresses_1 (temp_slot_address_entry **slot, void *)
701 const struct temp_slot_address_entry *t = *slot;
702 if (! t->temp_slot->in_use)
703 temp_slot_address_table->clear_slot (slot);
704 return 1;
707 /* Remove all mappings of addresses to unused temp slots. */
708 static void
709 remove_unused_temp_slot_addresses (void)
711 /* Use quicker clearing if there aren't any active temp slots. */
712 if (n_temp_slots_in_use)
713 temp_slot_address_table->traverse
714 <void *, remove_unused_temp_slot_addresses_1> (NULL);
715 else
716 temp_slot_address_table->empty ();
719 /* Find the temp slot corresponding to the object at address X. */
721 static struct temp_slot *
722 find_temp_slot_from_address (rtx x)
724 struct temp_slot *p;
725 struct temp_slot_address_entry tmp, *t;
727 /* First try the easy way:
728 See if X exists in the address -> temp slot mapping. */
729 tmp.address = x;
730 tmp.temp_slot = NULL;
731 tmp.hash = temp_slot_address_compute_hash (&tmp);
732 t = temp_slot_address_table->find_with_hash (&tmp, tmp.hash);
733 if (t)
734 return t->temp_slot;
736 /* If we have a sum involving a register, see if it points to a temp
737 slot. */
738 if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 0))
739 && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
740 return p;
741 else if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 1))
742 && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
743 return p;
745 /* Last resort: Address is a virtual stack var address. */
746 if (GET_CODE (x) == PLUS
747 && XEXP (x, 0) == virtual_stack_vars_rtx
748 && CONST_INT_P (XEXP (x, 1)))
750 int i;
751 for (i = max_slot_level (); i >= 0; i--)
752 for (p = *temp_slots_at_level (i); p; p = p->next)
754 if (INTVAL (XEXP (x, 1)) >= p->base_offset
755 && INTVAL (XEXP (x, 1)) < p->base_offset + p->full_size)
756 return p;
760 return NULL;
763 /* Allocate a temporary stack slot and record it for possible later
764 reuse.
766 MODE is the machine mode to be given to the returned rtx.
768 SIZE is the size in units of the space required. We do no rounding here
769 since assign_stack_local will do any required rounding.
771 TYPE is the type that will be used for the stack slot. */
774 assign_stack_temp_for_type (machine_mode mode, HOST_WIDE_INT size,
775 tree type)
777 unsigned int align;
778 struct temp_slot *p, *best_p = 0, *selected = NULL, **pp;
779 rtx slot;
781 /* If SIZE is -1 it means that somebody tried to allocate a temporary
782 of a variable size. */
783 gcc_assert (size != -1);
785 align = get_stack_local_alignment (type, mode);
787 /* Try to find an available, already-allocated temporary of the proper
788 mode which meets the size and alignment requirements. Choose the
789 smallest one with the closest alignment.
791 If assign_stack_temp is called outside of the tree->rtl expansion,
792 we cannot reuse the stack slots (that may still refer to
793 VIRTUAL_STACK_VARS_REGNUM). */
794 if (!virtuals_instantiated)
796 for (p = avail_temp_slots; p; p = p->next)
798 if (p->align >= align && p->size >= size
799 && GET_MODE (p->slot) == mode
800 && objects_must_conflict_p (p->type, type)
801 && (best_p == 0 || best_p->size > p->size
802 || (best_p->size == p->size && best_p->align > p->align)))
804 if (p->align == align && p->size == size)
806 selected = p;
807 cut_slot_from_list (selected, &avail_temp_slots);
808 best_p = 0;
809 break;
811 best_p = p;
816 /* Make our best, if any, the one to use. */
817 if (best_p)
819 selected = best_p;
820 cut_slot_from_list (selected, &avail_temp_slots);
822 /* If there are enough aligned bytes left over, make them into a new
823 temp_slot so that the extra bytes don't get wasted. Do this only
824 for BLKmode slots, so that we can be sure of the alignment. */
825 if (GET_MODE (best_p->slot) == BLKmode)
827 int alignment = best_p->align / BITS_PER_UNIT;
828 HOST_WIDE_INT rounded_size = CEIL_ROUND (size, alignment);
830 if (best_p->size - rounded_size >= alignment)
832 p = ggc_alloc<temp_slot> ();
833 p->in_use = 0;
834 p->size = best_p->size - rounded_size;
835 p->base_offset = best_p->base_offset + rounded_size;
836 p->full_size = best_p->full_size - rounded_size;
837 p->slot = adjust_address_nv (best_p->slot, BLKmode, rounded_size);
838 p->align = best_p->align;
839 p->type = best_p->type;
840 insert_slot_to_list (p, &avail_temp_slots);
842 vec_safe_push (stack_slot_list, p->slot);
844 best_p->size = rounded_size;
845 best_p->full_size = rounded_size;
850 /* If we still didn't find one, make a new temporary. */
851 if (selected == 0)
853 HOST_WIDE_INT frame_offset_old = frame_offset;
855 p = ggc_alloc<temp_slot> ();
857 /* We are passing an explicit alignment request to assign_stack_local.
858 One side effect of that is assign_stack_local will not round SIZE
859 to ensure the frame offset remains suitably aligned.
861 So for requests which depended on the rounding of SIZE, we go ahead
862 and round it now. We also make sure ALIGNMENT is at least
863 BIGGEST_ALIGNMENT. */
864 gcc_assert (mode != BLKmode || align == BIGGEST_ALIGNMENT);
865 p->slot = assign_stack_local_1 (mode,
866 (mode == BLKmode
867 ? CEIL_ROUND (size,
868 (int) align
869 / BITS_PER_UNIT)
870 : size),
871 align, 0);
873 p->align = align;
875 /* The following slot size computation is necessary because we don't
876 know the actual size of the temporary slot until assign_stack_local
877 has performed all the frame alignment and size rounding for the
878 requested temporary. Note that extra space added for alignment
879 can be either above or below this stack slot depending on which
880 way the frame grows. We include the extra space if and only if it
881 is above this slot. */
882 if (FRAME_GROWS_DOWNWARD)
883 p->size = frame_offset_old - frame_offset;
884 else
885 p->size = size;
887 /* Now define the fields used by combine_temp_slots. */
888 if (FRAME_GROWS_DOWNWARD)
890 p->base_offset = frame_offset;
891 p->full_size = frame_offset_old - frame_offset;
893 else
895 p->base_offset = frame_offset_old;
896 p->full_size = frame_offset - frame_offset_old;
899 selected = p;
902 p = selected;
903 p->in_use = 1;
904 p->type = type;
905 p->level = temp_slot_level;
906 n_temp_slots_in_use++;
908 pp = temp_slots_at_level (p->level);
909 insert_slot_to_list (p, pp);
910 insert_temp_slot_address (XEXP (p->slot, 0), p);
912 /* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
913 slot = gen_rtx_MEM (mode, XEXP (p->slot, 0));
914 vec_safe_push (stack_slot_list, slot);
916 /* If we know the alias set for the memory that will be used, use
917 it. If there's no TYPE, then we don't know anything about the
918 alias set for the memory. */
919 set_mem_alias_set (slot, type ? get_alias_set (type) : 0);
920 set_mem_align (slot, align);
922 /* If a type is specified, set the relevant flags. */
923 if (type != 0)
924 MEM_VOLATILE_P (slot) = TYPE_VOLATILE (type);
925 MEM_NOTRAP_P (slot) = 1;
927 return slot;
930 /* Allocate a temporary stack slot and record it for possible later
931 reuse. First two arguments are same as in preceding function. */
934 assign_stack_temp (machine_mode mode, HOST_WIDE_INT size)
936 return assign_stack_temp_for_type (mode, size, NULL_TREE);
939 /* Assign a temporary.
940 If TYPE_OR_DECL is a decl, then we are doing it on behalf of the decl
941 and so that should be used in error messages. In either case, we
942 allocate of the given type.
943 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
944 it is 0 if a register is OK.
945 DONT_PROMOTE is 1 if we should not promote values in register
946 to wider modes. */
949 assign_temp (tree type_or_decl, int memory_required,
950 int dont_promote ATTRIBUTE_UNUSED)
952 tree type, decl;
953 machine_mode mode;
954 #ifdef PROMOTE_MODE
955 int unsignedp;
956 #endif
958 if (DECL_P (type_or_decl))
959 decl = type_or_decl, type = TREE_TYPE (decl);
960 else
961 decl = NULL, type = type_or_decl;
963 mode = TYPE_MODE (type);
964 #ifdef PROMOTE_MODE
965 unsignedp = TYPE_UNSIGNED (type);
966 #endif
968 /* Allocating temporaries of TREE_ADDRESSABLE type must be done in the front
969 end. See also create_tmp_var for the gimplification-time check. */
970 gcc_assert (!TREE_ADDRESSABLE (type) && COMPLETE_TYPE_P (type));
972 if (mode == BLKmode || memory_required)
974 HOST_WIDE_INT size = int_size_in_bytes (type);
975 rtx tmp;
977 /* Zero sized arrays are GNU C extension. Set size to 1 to avoid
978 problems with allocating the stack space. */
979 if (size == 0)
980 size = 1;
982 /* Unfortunately, we don't yet know how to allocate variable-sized
983 temporaries. However, sometimes we can find a fixed upper limit on
984 the size, so try that instead. */
985 else if (size == -1)
986 size = max_int_size_in_bytes (type);
988 /* The size of the temporary may be too large to fit into an integer. */
989 /* ??? Not sure this should happen except for user silliness, so limit
990 this to things that aren't compiler-generated temporaries. The
991 rest of the time we'll die in assign_stack_temp_for_type. */
992 if (decl && size == -1
993 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST)
995 error ("size of variable %q+D is too large", decl);
996 size = 1;
999 tmp = assign_stack_temp_for_type (mode, size, type);
1000 return tmp;
1003 #ifdef PROMOTE_MODE
1004 if (! dont_promote)
1005 mode = promote_mode (type, mode, &unsignedp);
1006 #endif
1008 return gen_reg_rtx (mode);
1011 /* Combine temporary stack slots which are adjacent on the stack.
1013 This allows for better use of already allocated stack space. This is only
1014 done for BLKmode slots because we can be sure that we won't have alignment
1015 problems in this case. */
1017 static void
1018 combine_temp_slots (void)
1020 struct temp_slot *p, *q, *next, *next_q;
1021 int num_slots;
1023 /* We can't combine slots, because the information about which slot
1024 is in which alias set will be lost. */
1025 if (flag_strict_aliasing)
1026 return;
1028 /* If there are a lot of temp slots, don't do anything unless
1029 high levels of optimization. */
1030 if (! flag_expensive_optimizations)
1031 for (p = avail_temp_slots, num_slots = 0; p; p = p->next, num_slots++)
1032 if (num_slots > 100 || (num_slots > 10 && optimize == 0))
1033 return;
1035 for (p = avail_temp_slots; p; p = next)
1037 int delete_p = 0;
1039 next = p->next;
1041 if (GET_MODE (p->slot) != BLKmode)
1042 continue;
1044 for (q = p->next; q; q = next_q)
1046 int delete_q = 0;
1048 next_q = q->next;
1050 if (GET_MODE (q->slot) != BLKmode)
1051 continue;
1053 if (p->base_offset + p->full_size == q->base_offset)
1055 /* Q comes after P; combine Q into P. */
1056 p->size += q->size;
1057 p->full_size += q->full_size;
1058 delete_q = 1;
1060 else if (q->base_offset + q->full_size == p->base_offset)
1062 /* P comes after Q; combine P into Q. */
1063 q->size += p->size;
1064 q->full_size += p->full_size;
1065 delete_p = 1;
1066 break;
1068 if (delete_q)
1069 cut_slot_from_list (q, &avail_temp_slots);
1072 /* Either delete P or advance past it. */
1073 if (delete_p)
1074 cut_slot_from_list (p, &avail_temp_slots);
1078 /* Indicate that NEW_RTX is an alternate way of referring to the temp
1079 slot that previously was known by OLD_RTX. */
1081 void
1082 update_temp_slot_address (rtx old_rtx, rtx new_rtx)
1084 struct temp_slot *p;
1086 if (rtx_equal_p (old_rtx, new_rtx))
1087 return;
1089 p = find_temp_slot_from_address (old_rtx);
1091 /* If we didn't find one, see if both OLD_RTX is a PLUS. If so, and
1092 NEW_RTX is a register, see if one operand of the PLUS is a
1093 temporary location. If so, NEW_RTX points into it. Otherwise,
1094 if both OLD_RTX and NEW_RTX are a PLUS and if there is a register
1095 in common between them. If so, try a recursive call on those
1096 values. */
1097 if (p == 0)
1099 if (GET_CODE (old_rtx) != PLUS)
1100 return;
1102 if (REG_P (new_rtx))
1104 update_temp_slot_address (XEXP (old_rtx, 0), new_rtx);
1105 update_temp_slot_address (XEXP (old_rtx, 1), new_rtx);
1106 return;
1108 else if (GET_CODE (new_rtx) != PLUS)
1109 return;
1111 if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 0)))
1112 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 1));
1113 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 0)))
1114 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 1));
1115 else if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 1)))
1116 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 0));
1117 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 1)))
1118 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 0));
1120 return;
1123 /* Otherwise add an alias for the temp's address. */
1124 insert_temp_slot_address (new_rtx, p);
1127 /* If X could be a reference to a temporary slot, mark that slot as
1128 belonging to the to one level higher than the current level. If X
1129 matched one of our slots, just mark that one. Otherwise, we can't
1130 easily predict which it is, so upgrade all of them.
1132 This is called when an ({...}) construct occurs and a statement
1133 returns a value in memory. */
1135 void
1136 preserve_temp_slots (rtx x)
1138 struct temp_slot *p = 0, *next;
1140 if (x == 0)
1141 return;
1143 /* If X is a register that is being used as a pointer, see if we have
1144 a temporary slot we know it points to. */
1145 if (REG_P (x) && REG_POINTER (x))
1146 p = find_temp_slot_from_address (x);
1148 /* If X is not in memory or is at a constant address, it cannot be in
1149 a temporary slot. */
1150 if (p == 0 && (!MEM_P (x) || CONSTANT_P (XEXP (x, 0))))
1151 return;
1153 /* First see if we can find a match. */
1154 if (p == 0)
1155 p = find_temp_slot_from_address (XEXP (x, 0));
1157 if (p != 0)
1159 if (p->level == temp_slot_level)
1160 move_slot_to_level (p, temp_slot_level - 1);
1161 return;
1164 /* Otherwise, preserve all non-kept slots at this level. */
1165 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1167 next = p->next;
1168 move_slot_to_level (p, temp_slot_level - 1);
1172 /* Free all temporaries used so far. This is normally called at the
1173 end of generating code for a statement. */
1175 void
1176 free_temp_slots (void)
1178 struct temp_slot *p, *next;
1179 bool some_available = false;
1181 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1183 next = p->next;
1184 make_slot_available (p);
1185 some_available = true;
1188 if (some_available)
1190 remove_unused_temp_slot_addresses ();
1191 combine_temp_slots ();
1195 /* Push deeper into the nesting level for stack temporaries. */
1197 void
1198 push_temp_slots (void)
1200 temp_slot_level++;
1203 /* Pop a temporary nesting level. All slots in use in the current level
1204 are freed. */
1206 void
1207 pop_temp_slots (void)
1209 free_temp_slots ();
1210 temp_slot_level--;
1213 /* Initialize temporary slots. */
1215 void
1216 init_temp_slots (void)
1218 /* We have not allocated any temporaries yet. */
1219 avail_temp_slots = 0;
1220 vec_alloc (used_temp_slots, 0);
1221 temp_slot_level = 0;
1222 n_temp_slots_in_use = 0;
1224 /* Set up the table to map addresses to temp slots. */
1225 if (! temp_slot_address_table)
1226 temp_slot_address_table = hash_table<temp_address_hasher>::create_ggc (32);
1227 else
1228 temp_slot_address_table->empty ();
1231 /* Functions and data structures to keep track of the values hard regs
1232 had at the start of the function. */
1234 /* Private type used by get_hard_reg_initial_reg, get_hard_reg_initial_val,
1235 and has_hard_reg_initial_val.. */
1236 struct GTY(()) initial_value_pair {
1237 rtx hard_reg;
1238 rtx pseudo;
1240 /* ??? This could be a VEC but there is currently no way to define an
1241 opaque VEC type. This could be worked around by defining struct
1242 initial_value_pair in function.h. */
1243 struct GTY(()) initial_value_struct {
1244 int num_entries;
1245 int max_entries;
1246 initial_value_pair * GTY ((length ("%h.num_entries"))) entries;
1249 /* If a pseudo represents an initial hard reg (or expression), return
1250 it, else return NULL_RTX. */
1253 get_hard_reg_initial_reg (rtx reg)
1255 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1256 int i;
1258 if (ivs == 0)
1259 return NULL_RTX;
1261 for (i = 0; i < ivs->num_entries; i++)
1262 if (rtx_equal_p (ivs->entries[i].pseudo, reg))
1263 return ivs->entries[i].hard_reg;
1265 return NULL_RTX;
1268 /* Make sure that there's a pseudo register of mode MODE that stores the
1269 initial value of hard register REGNO. Return an rtx for such a pseudo. */
1272 get_hard_reg_initial_val (machine_mode mode, unsigned int regno)
1274 struct initial_value_struct *ivs;
1275 rtx rv;
1277 rv = has_hard_reg_initial_val (mode, regno);
1278 if (rv)
1279 return rv;
1281 ivs = crtl->hard_reg_initial_vals;
1282 if (ivs == 0)
1284 ivs = ggc_alloc<initial_value_struct> ();
1285 ivs->num_entries = 0;
1286 ivs->max_entries = 5;
1287 ivs->entries = ggc_vec_alloc<initial_value_pair> (5);
1288 crtl->hard_reg_initial_vals = ivs;
1291 if (ivs->num_entries >= ivs->max_entries)
1293 ivs->max_entries += 5;
1294 ivs->entries = GGC_RESIZEVEC (initial_value_pair, ivs->entries,
1295 ivs->max_entries);
1298 ivs->entries[ivs->num_entries].hard_reg = gen_rtx_REG (mode, regno);
1299 ivs->entries[ivs->num_entries].pseudo = gen_reg_rtx (mode);
1301 return ivs->entries[ivs->num_entries++].pseudo;
1304 /* See if get_hard_reg_initial_val has been used to create a pseudo
1305 for the initial value of hard register REGNO in mode MODE. Return
1306 the associated pseudo if so, otherwise return NULL. */
1309 has_hard_reg_initial_val (machine_mode mode, unsigned int regno)
1311 struct initial_value_struct *ivs;
1312 int i;
1314 ivs = crtl->hard_reg_initial_vals;
1315 if (ivs != 0)
1316 for (i = 0; i < ivs->num_entries; i++)
1317 if (GET_MODE (ivs->entries[i].hard_reg) == mode
1318 && REGNO (ivs->entries[i].hard_reg) == regno)
1319 return ivs->entries[i].pseudo;
1321 return NULL_RTX;
1324 unsigned int
1325 emit_initial_value_sets (void)
1327 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1328 int i;
1329 rtx_insn *seq;
1331 if (ivs == 0)
1332 return 0;
1334 start_sequence ();
1335 for (i = 0; i < ivs->num_entries; i++)
1336 emit_move_insn (ivs->entries[i].pseudo, ivs->entries[i].hard_reg);
1337 seq = get_insns ();
1338 end_sequence ();
1340 emit_insn_at_entry (seq);
1341 return 0;
1344 /* Return the hardreg-pseudoreg initial values pair entry I and
1345 TRUE if I is a valid entry, or FALSE if I is not a valid entry. */
1346 bool
1347 initial_value_entry (int i, rtx *hreg, rtx *preg)
1349 struct initial_value_struct *ivs = crtl->hard_reg_initial_vals;
1350 if (!ivs || i >= ivs->num_entries)
1351 return false;
1353 *hreg = ivs->entries[i].hard_reg;
1354 *preg = ivs->entries[i].pseudo;
1355 return true;
1358 /* These routines are responsible for converting virtual register references
1359 to the actual hard register references once RTL generation is complete.
1361 The following four variables are used for communication between the
1362 routines. They contain the offsets of the virtual registers from their
1363 respective hard registers. */
1365 static int in_arg_offset;
1366 static int var_offset;
1367 static int dynamic_offset;
1368 static int out_arg_offset;
1369 static int cfa_offset;
1371 /* In most machines, the stack pointer register is equivalent to the bottom
1372 of the stack. */
1374 #ifndef STACK_POINTER_OFFSET
1375 #define STACK_POINTER_OFFSET 0
1376 #endif
1378 #if defined (REG_PARM_STACK_SPACE) && !defined (INCOMING_REG_PARM_STACK_SPACE)
1379 #define INCOMING_REG_PARM_STACK_SPACE REG_PARM_STACK_SPACE
1380 #endif
1382 /* If not defined, pick an appropriate default for the offset of dynamically
1383 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
1384 INCOMING_REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
1386 #ifndef STACK_DYNAMIC_OFFSET
1388 /* The bottom of the stack points to the actual arguments. If
1389 REG_PARM_STACK_SPACE is defined, this includes the space for the register
1390 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
1391 stack space for register parameters is not pushed by the caller, but
1392 rather part of the fixed stack areas and hence not included in
1393 `crtl->outgoing_args_size'. Nevertheless, we must allow
1394 for it when allocating stack dynamic objects. */
1396 #ifdef INCOMING_REG_PARM_STACK_SPACE
1397 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1398 ((ACCUMULATE_OUTGOING_ARGS \
1399 ? (crtl->outgoing_args_size \
1400 + (OUTGOING_REG_PARM_STACK_SPACE ((!(FNDECL) ? NULL_TREE : TREE_TYPE (FNDECL))) ? 0 \
1401 : INCOMING_REG_PARM_STACK_SPACE (FNDECL))) \
1402 : 0) + (STACK_POINTER_OFFSET))
1403 #else
1404 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1405 ((ACCUMULATE_OUTGOING_ARGS ? crtl->outgoing_args_size : 0) \
1406 + (STACK_POINTER_OFFSET))
1407 #endif
1408 #endif
1411 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
1412 is a virtual register, return the equivalent hard register and set the
1413 offset indirectly through the pointer. Otherwise, return 0. */
1415 static rtx
1416 instantiate_new_reg (rtx x, HOST_WIDE_INT *poffset)
1418 rtx new_rtx;
1419 HOST_WIDE_INT offset;
1421 if (x == virtual_incoming_args_rtx)
1423 if (stack_realign_drap)
1425 /* Replace virtual_incoming_args_rtx with internal arg
1426 pointer if DRAP is used to realign stack. */
1427 new_rtx = crtl->args.internal_arg_pointer;
1428 offset = 0;
1430 else
1431 new_rtx = arg_pointer_rtx, offset = in_arg_offset;
1433 else if (x == virtual_stack_vars_rtx)
1434 new_rtx = frame_pointer_rtx, offset = var_offset;
1435 else if (x == virtual_stack_dynamic_rtx)
1436 new_rtx = stack_pointer_rtx, offset = dynamic_offset;
1437 else if (x == virtual_outgoing_args_rtx)
1438 new_rtx = stack_pointer_rtx, offset = out_arg_offset;
1439 else if (x == virtual_cfa_rtx)
1441 #ifdef FRAME_POINTER_CFA_OFFSET
1442 new_rtx = frame_pointer_rtx;
1443 #else
1444 new_rtx = arg_pointer_rtx;
1445 #endif
1446 offset = cfa_offset;
1448 else if (x == virtual_preferred_stack_boundary_rtx)
1450 new_rtx = GEN_INT (crtl->preferred_stack_boundary / BITS_PER_UNIT);
1451 offset = 0;
1453 else
1454 return NULL_RTX;
1456 *poffset = offset;
1457 return new_rtx;
1460 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1461 registers present inside of *LOC. The expression is simplified,
1462 as much as possible, but is not to be considered "valid" in any sense
1463 implied by the target. Return true if any change is made. */
1465 static bool
1466 instantiate_virtual_regs_in_rtx (rtx *loc)
1468 if (!*loc)
1469 return false;
1470 bool changed = false;
1471 subrtx_ptr_iterator::array_type array;
1472 FOR_EACH_SUBRTX_PTR (iter, array, loc, NONCONST)
1474 rtx *loc = *iter;
1475 if (rtx x = *loc)
1477 rtx new_rtx;
1478 HOST_WIDE_INT offset;
1479 switch (GET_CODE (x))
1481 case REG:
1482 new_rtx = instantiate_new_reg (x, &offset);
1483 if (new_rtx)
1485 *loc = plus_constant (GET_MODE (x), new_rtx, offset);
1486 changed = true;
1488 iter.skip_subrtxes ();
1489 break;
1491 case PLUS:
1492 new_rtx = instantiate_new_reg (XEXP (x, 0), &offset);
1493 if (new_rtx)
1495 XEXP (x, 0) = new_rtx;
1496 *loc = plus_constant (GET_MODE (x), x, offset, true);
1497 changed = true;
1498 iter.skip_subrtxes ();
1499 break;
1502 /* FIXME -- from old code */
1503 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
1504 we can commute the PLUS and SUBREG because pointers into the
1505 frame are well-behaved. */
1506 break;
1508 default:
1509 break;
1513 return changed;
1516 /* A subroutine of instantiate_virtual_regs_in_insn. Return true if X
1517 matches the predicate for insn CODE operand OPERAND. */
1519 static int
1520 safe_insn_predicate (int code, int operand, rtx x)
1522 return code < 0 || insn_operand_matches ((enum insn_code) code, operand, x);
1525 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1526 registers present inside of insn. The result will be a valid insn. */
1528 static void
1529 instantiate_virtual_regs_in_insn (rtx_insn *insn)
1531 HOST_WIDE_INT offset;
1532 int insn_code, i;
1533 bool any_change = false;
1534 rtx set, new_rtx, x;
1535 rtx_insn *seq;
1537 /* There are some special cases to be handled first. */
1538 set = single_set (insn);
1539 if (set)
1541 /* We're allowed to assign to a virtual register. This is interpreted
1542 to mean that the underlying register gets assigned the inverse
1543 transformation. This is used, for example, in the handling of
1544 non-local gotos. */
1545 new_rtx = instantiate_new_reg (SET_DEST (set), &offset);
1546 if (new_rtx)
1548 start_sequence ();
1550 instantiate_virtual_regs_in_rtx (&SET_SRC (set));
1551 x = simplify_gen_binary (PLUS, GET_MODE (new_rtx), SET_SRC (set),
1552 gen_int_mode (-offset, GET_MODE (new_rtx)));
1553 x = force_operand (x, new_rtx);
1554 if (x != new_rtx)
1555 emit_move_insn (new_rtx, x);
1557 seq = get_insns ();
1558 end_sequence ();
1560 emit_insn_before (seq, insn);
1561 delete_insn (insn);
1562 return;
1565 /* Handle a straight copy from a virtual register by generating a
1566 new add insn. The difference between this and falling through
1567 to the generic case is avoiding a new pseudo and eliminating a
1568 move insn in the initial rtl stream. */
1569 new_rtx = instantiate_new_reg (SET_SRC (set), &offset);
1570 if (new_rtx && offset != 0
1571 && REG_P (SET_DEST (set))
1572 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1574 start_sequence ();
1576 x = expand_simple_binop (GET_MODE (SET_DEST (set)), PLUS, new_rtx,
1577 gen_int_mode (offset,
1578 GET_MODE (SET_DEST (set))),
1579 SET_DEST (set), 1, OPTAB_LIB_WIDEN);
1580 if (x != SET_DEST (set))
1581 emit_move_insn (SET_DEST (set), x);
1583 seq = get_insns ();
1584 end_sequence ();
1586 emit_insn_before (seq, insn);
1587 delete_insn (insn);
1588 return;
1591 extract_insn (insn);
1592 insn_code = INSN_CODE (insn);
1594 /* Handle a plus involving a virtual register by determining if the
1595 operands remain valid if they're modified in place. */
1596 if (GET_CODE (SET_SRC (set)) == PLUS
1597 && recog_data.n_operands >= 3
1598 && recog_data.operand_loc[1] == &XEXP (SET_SRC (set), 0)
1599 && recog_data.operand_loc[2] == &XEXP (SET_SRC (set), 1)
1600 && CONST_INT_P (recog_data.operand[2])
1601 && (new_rtx = instantiate_new_reg (recog_data.operand[1], &offset)))
1603 offset += INTVAL (recog_data.operand[2]);
1605 /* If the sum is zero, then replace with a plain move. */
1606 if (offset == 0
1607 && REG_P (SET_DEST (set))
1608 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1610 start_sequence ();
1611 emit_move_insn (SET_DEST (set), new_rtx);
1612 seq = get_insns ();
1613 end_sequence ();
1615 emit_insn_before (seq, insn);
1616 delete_insn (insn);
1617 return;
1620 x = gen_int_mode (offset, recog_data.operand_mode[2]);
1622 /* Using validate_change and apply_change_group here leaves
1623 recog_data in an invalid state. Since we know exactly what
1624 we want to check, do those two by hand. */
1625 if (safe_insn_predicate (insn_code, 1, new_rtx)
1626 && safe_insn_predicate (insn_code, 2, x))
1628 *recog_data.operand_loc[1] = recog_data.operand[1] = new_rtx;
1629 *recog_data.operand_loc[2] = recog_data.operand[2] = x;
1630 any_change = true;
1632 /* Fall through into the regular operand fixup loop in
1633 order to take care of operands other than 1 and 2. */
1637 else
1639 extract_insn (insn);
1640 insn_code = INSN_CODE (insn);
1643 /* In the general case, we expect virtual registers to appear only in
1644 operands, and then only as either bare registers or inside memories. */
1645 for (i = 0; i < recog_data.n_operands; ++i)
1647 x = recog_data.operand[i];
1648 switch (GET_CODE (x))
1650 case MEM:
1652 rtx addr = XEXP (x, 0);
1654 if (!instantiate_virtual_regs_in_rtx (&addr))
1655 continue;
1657 start_sequence ();
1658 x = replace_equiv_address (x, addr, true);
1659 /* It may happen that the address with the virtual reg
1660 was valid (e.g. based on the virtual stack reg, which might
1661 be acceptable to the predicates with all offsets), whereas
1662 the address now isn't anymore, for instance when the address
1663 is still offsetted, but the base reg isn't virtual-stack-reg
1664 anymore. Below we would do a force_reg on the whole operand,
1665 but this insn might actually only accept memory. Hence,
1666 before doing that last resort, try to reload the address into
1667 a register, so this operand stays a MEM. */
1668 if (!safe_insn_predicate (insn_code, i, x))
1670 addr = force_reg (GET_MODE (addr), addr);
1671 x = replace_equiv_address (x, addr, true);
1673 seq = get_insns ();
1674 end_sequence ();
1675 if (seq)
1676 emit_insn_before (seq, insn);
1678 break;
1680 case REG:
1681 new_rtx = instantiate_new_reg (x, &offset);
1682 if (new_rtx == NULL)
1683 continue;
1684 if (offset == 0)
1685 x = new_rtx;
1686 else
1688 start_sequence ();
1690 /* Careful, special mode predicates may have stuff in
1691 insn_data[insn_code].operand[i].mode that isn't useful
1692 to us for computing a new value. */
1693 /* ??? Recognize address_operand and/or "p" constraints
1694 to see if (plus new offset) is a valid before we put
1695 this through expand_simple_binop. */
1696 x = expand_simple_binop (GET_MODE (x), PLUS, new_rtx,
1697 gen_int_mode (offset, GET_MODE (x)),
1698 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1699 seq = get_insns ();
1700 end_sequence ();
1701 emit_insn_before (seq, insn);
1703 break;
1705 case SUBREG:
1706 new_rtx = instantiate_new_reg (SUBREG_REG (x), &offset);
1707 if (new_rtx == NULL)
1708 continue;
1709 if (offset != 0)
1711 start_sequence ();
1712 new_rtx = expand_simple_binop
1713 (GET_MODE (new_rtx), PLUS, new_rtx,
1714 gen_int_mode (offset, GET_MODE (new_rtx)),
1715 NULL_RTX, 1, OPTAB_LIB_WIDEN);
1716 seq = get_insns ();
1717 end_sequence ();
1718 emit_insn_before (seq, insn);
1720 x = simplify_gen_subreg (recog_data.operand_mode[i], new_rtx,
1721 GET_MODE (new_rtx), SUBREG_BYTE (x));
1722 gcc_assert (x);
1723 break;
1725 default:
1726 continue;
1729 /* At this point, X contains the new value for the operand.
1730 Validate the new value vs the insn predicate. Note that
1731 asm insns will have insn_code -1 here. */
1732 if (!safe_insn_predicate (insn_code, i, x))
1734 start_sequence ();
1735 if (REG_P (x))
1737 gcc_assert (REGNO (x) <= LAST_VIRTUAL_REGISTER);
1738 x = copy_to_reg (x);
1740 else
1741 x = force_reg (insn_data[insn_code].operand[i].mode, x);
1742 seq = get_insns ();
1743 end_sequence ();
1744 if (seq)
1745 emit_insn_before (seq, insn);
1748 *recog_data.operand_loc[i] = recog_data.operand[i] = x;
1749 any_change = true;
1752 if (any_change)
1754 /* Propagate operand changes into the duplicates. */
1755 for (i = 0; i < recog_data.n_dups; ++i)
1756 *recog_data.dup_loc[i]
1757 = copy_rtx (recog_data.operand[(unsigned)recog_data.dup_num[i]]);
1759 /* Force re-recognition of the instruction for validation. */
1760 INSN_CODE (insn) = -1;
1763 if (asm_noperands (PATTERN (insn)) >= 0)
1765 if (!check_asm_operands (PATTERN (insn)))
1767 error_for_asm (insn, "impossible constraint in %<asm%>");
1768 /* For asm goto, instead of fixing up all the edges
1769 just clear the template and clear input operands
1770 (asm goto doesn't have any output operands). */
1771 if (JUMP_P (insn))
1773 rtx asm_op = extract_asm_operands (PATTERN (insn));
1774 ASM_OPERANDS_TEMPLATE (asm_op) = ggc_strdup ("");
1775 ASM_OPERANDS_INPUT_VEC (asm_op) = rtvec_alloc (0);
1776 ASM_OPERANDS_INPUT_CONSTRAINT_VEC (asm_op) = rtvec_alloc (0);
1778 else
1779 delete_insn (insn);
1782 else
1784 if (recog_memoized (insn) < 0)
1785 fatal_insn_not_found (insn);
1789 /* Subroutine of instantiate_decls. Given RTL representing a decl,
1790 do any instantiation required. */
1792 void
1793 instantiate_decl_rtl (rtx x)
1795 rtx addr;
1797 if (x == 0)
1798 return;
1800 /* If this is a CONCAT, recurse for the pieces. */
1801 if (GET_CODE (x) == CONCAT)
1803 instantiate_decl_rtl (XEXP (x, 0));
1804 instantiate_decl_rtl (XEXP (x, 1));
1805 return;
1808 /* If this is not a MEM, no need to do anything. Similarly if the
1809 address is a constant or a register that is not a virtual register. */
1810 if (!MEM_P (x))
1811 return;
1813 addr = XEXP (x, 0);
1814 if (CONSTANT_P (addr)
1815 || (REG_P (addr)
1816 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
1817 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
1818 return;
1820 instantiate_virtual_regs_in_rtx (&XEXP (x, 0));
1823 /* Helper for instantiate_decls called via walk_tree: Process all decls
1824 in the given DECL_VALUE_EXPR. */
1826 static tree
1827 instantiate_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1829 tree t = *tp;
1830 if (! EXPR_P (t))
1832 *walk_subtrees = 0;
1833 if (DECL_P (t))
1835 if (DECL_RTL_SET_P (t))
1836 instantiate_decl_rtl (DECL_RTL (t));
1837 if (TREE_CODE (t) == PARM_DECL && DECL_NAMELESS (t)
1838 && DECL_INCOMING_RTL (t))
1839 instantiate_decl_rtl (DECL_INCOMING_RTL (t));
1840 if ((VAR_P (t) || TREE_CODE (t) == RESULT_DECL)
1841 && DECL_HAS_VALUE_EXPR_P (t))
1843 tree v = DECL_VALUE_EXPR (t);
1844 walk_tree (&v, instantiate_expr, NULL, NULL);
1848 return NULL;
1851 /* Subroutine of instantiate_decls: Process all decls in the given
1852 BLOCK node and all its subblocks. */
1854 static void
1855 instantiate_decls_1 (tree let)
1857 tree t;
1859 for (t = BLOCK_VARS (let); t; t = DECL_CHAIN (t))
1861 if (DECL_RTL_SET_P (t))
1862 instantiate_decl_rtl (DECL_RTL (t));
1863 if (VAR_P (t) && DECL_HAS_VALUE_EXPR_P (t))
1865 tree v = DECL_VALUE_EXPR (t);
1866 walk_tree (&v, instantiate_expr, NULL, NULL);
1870 /* Process all subblocks. */
1871 for (t = BLOCK_SUBBLOCKS (let); t; t = BLOCK_CHAIN (t))
1872 instantiate_decls_1 (t);
1875 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1876 all virtual registers in their DECL_RTL's. */
1878 static void
1879 instantiate_decls (tree fndecl)
1881 tree decl;
1882 unsigned ix;
1884 /* Process all parameters of the function. */
1885 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = DECL_CHAIN (decl))
1887 instantiate_decl_rtl (DECL_RTL (decl));
1888 instantiate_decl_rtl (DECL_INCOMING_RTL (decl));
1889 if (DECL_HAS_VALUE_EXPR_P (decl))
1891 tree v = DECL_VALUE_EXPR (decl);
1892 walk_tree (&v, instantiate_expr, NULL, NULL);
1896 if ((decl = DECL_RESULT (fndecl))
1897 && TREE_CODE (decl) == RESULT_DECL)
1899 if (DECL_RTL_SET_P (decl))
1900 instantiate_decl_rtl (DECL_RTL (decl));
1901 if (DECL_HAS_VALUE_EXPR_P (decl))
1903 tree v = DECL_VALUE_EXPR (decl);
1904 walk_tree (&v, instantiate_expr, NULL, NULL);
1908 /* Process the saved static chain if it exists. */
1909 decl = DECL_STRUCT_FUNCTION (fndecl)->static_chain_decl;
1910 if (decl && DECL_HAS_VALUE_EXPR_P (decl))
1911 instantiate_decl_rtl (DECL_RTL (DECL_VALUE_EXPR (decl)));
1913 /* Now process all variables defined in the function or its subblocks. */
1914 if (DECL_INITIAL (fndecl))
1915 instantiate_decls_1 (DECL_INITIAL (fndecl));
1917 FOR_EACH_LOCAL_DECL (cfun, ix, decl)
1918 if (DECL_RTL_SET_P (decl))
1919 instantiate_decl_rtl (DECL_RTL (decl));
1920 vec_free (cfun->local_decls);
1923 /* Pass through the INSNS of function FNDECL and convert virtual register
1924 references to hard register references. */
1926 static unsigned int
1927 instantiate_virtual_regs (void)
1929 rtx_insn *insn;
1931 /* Compute the offsets to use for this function. */
1932 in_arg_offset = FIRST_PARM_OFFSET (current_function_decl);
1933 var_offset = targetm.starting_frame_offset ();
1934 dynamic_offset = STACK_DYNAMIC_OFFSET (current_function_decl);
1935 out_arg_offset = STACK_POINTER_OFFSET;
1936 #ifdef FRAME_POINTER_CFA_OFFSET
1937 cfa_offset = FRAME_POINTER_CFA_OFFSET (current_function_decl);
1938 #else
1939 cfa_offset = ARG_POINTER_CFA_OFFSET (current_function_decl);
1940 #endif
1942 /* Initialize recognition, indicating that volatile is OK. */
1943 init_recog ();
1945 /* Scan through all the insns, instantiating every virtual register still
1946 present. */
1947 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
1948 if (INSN_P (insn))
1950 /* These patterns in the instruction stream can never be recognized.
1951 Fortunately, they shouldn't contain virtual registers either. */
1952 if (GET_CODE (PATTERN (insn)) == USE
1953 || GET_CODE (PATTERN (insn)) == CLOBBER
1954 || GET_CODE (PATTERN (insn)) == ASM_INPUT)
1955 continue;
1956 else if (DEBUG_INSN_P (insn))
1957 instantiate_virtual_regs_in_rtx (&INSN_VAR_LOCATION (insn));
1958 else
1959 instantiate_virtual_regs_in_insn (insn);
1961 if (insn->deleted ())
1962 continue;
1964 instantiate_virtual_regs_in_rtx (&REG_NOTES (insn));
1966 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
1967 if (CALL_P (insn))
1968 instantiate_virtual_regs_in_rtx (&CALL_INSN_FUNCTION_USAGE (insn));
1971 /* Instantiate the virtual registers in the DECLs for debugging purposes. */
1972 instantiate_decls (current_function_decl);
1974 targetm.instantiate_decls ();
1976 /* Indicate that, from now on, assign_stack_local should use
1977 frame_pointer_rtx. */
1978 virtuals_instantiated = 1;
1980 return 0;
1983 namespace {
1985 const pass_data pass_data_instantiate_virtual_regs =
1987 RTL_PASS, /* type */
1988 "vregs", /* name */
1989 OPTGROUP_NONE, /* optinfo_flags */
1990 TV_NONE, /* tv_id */
1991 0, /* properties_required */
1992 0, /* properties_provided */
1993 0, /* properties_destroyed */
1994 0, /* todo_flags_start */
1995 0, /* todo_flags_finish */
1998 class pass_instantiate_virtual_regs : public rtl_opt_pass
2000 public:
2001 pass_instantiate_virtual_regs (gcc::context *ctxt)
2002 : rtl_opt_pass (pass_data_instantiate_virtual_regs, ctxt)
2005 /* opt_pass methods: */
2006 virtual unsigned int execute (function *)
2008 return instantiate_virtual_regs ();
2011 }; // class pass_instantiate_virtual_regs
2013 } // anon namespace
2015 rtl_opt_pass *
2016 make_pass_instantiate_virtual_regs (gcc::context *ctxt)
2018 return new pass_instantiate_virtual_regs (ctxt);
2022 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
2023 This means a type for which function calls must pass an address to the
2024 function or get an address back from the function.
2025 EXP may be a type node or an expression (whose type is tested). */
2028 aggregate_value_p (const_tree exp, const_tree fntype)
2030 const_tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
2031 int i, regno, nregs;
2032 rtx reg;
2034 if (fntype)
2035 switch (TREE_CODE (fntype))
2037 case CALL_EXPR:
2039 tree fndecl = get_callee_fndecl (fntype);
2040 if (fndecl)
2041 fntype = TREE_TYPE (fndecl);
2042 else if (CALL_EXPR_FN (fntype))
2043 fntype = TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (fntype)));
2044 else
2045 /* For internal functions, assume nothing needs to be
2046 returned in memory. */
2047 return 0;
2049 break;
2050 case FUNCTION_DECL:
2051 fntype = TREE_TYPE (fntype);
2052 break;
2053 case FUNCTION_TYPE:
2054 case METHOD_TYPE:
2055 break;
2056 case IDENTIFIER_NODE:
2057 fntype = NULL_TREE;
2058 break;
2059 default:
2060 /* We don't expect other tree types here. */
2061 gcc_unreachable ();
2064 if (VOID_TYPE_P (type))
2065 return 0;
2067 /* If a record should be passed the same as its first (and only) member
2068 don't pass it as an aggregate. */
2069 if (TREE_CODE (type) == RECORD_TYPE && TYPE_TRANSPARENT_AGGR (type))
2070 return aggregate_value_p (first_field (type), fntype);
2072 /* If the front end has decided that this needs to be passed by
2073 reference, do so. */
2074 if ((TREE_CODE (exp) == PARM_DECL || TREE_CODE (exp) == RESULT_DECL)
2075 && DECL_BY_REFERENCE (exp))
2076 return 1;
2078 /* Function types that are TREE_ADDRESSABLE force return in memory. */
2079 if (fntype && TREE_ADDRESSABLE (fntype))
2080 return 1;
2082 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
2083 and thus can't be returned in registers. */
2084 if (TREE_ADDRESSABLE (type))
2085 return 1;
2087 if (TYPE_EMPTY_P (type))
2088 return 0;
2090 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
2091 return 1;
2093 if (targetm.calls.return_in_memory (type, fntype))
2094 return 1;
2096 /* Make sure we have suitable call-clobbered regs to return
2097 the value in; if not, we must return it in memory. */
2098 reg = hard_function_value (type, 0, fntype, 0);
2100 /* If we have something other than a REG (e.g. a PARALLEL), then assume
2101 it is OK. */
2102 if (!REG_P (reg))
2103 return 0;
2105 regno = REGNO (reg);
2106 nregs = hard_regno_nregs (regno, TYPE_MODE (type));
2107 for (i = 0; i < nregs; i++)
2108 if (! call_used_regs[regno + i])
2109 return 1;
2111 return 0;
2114 /* Return true if we should assign DECL a pseudo register; false if it
2115 should live on the local stack. */
2117 bool
2118 use_register_for_decl (const_tree decl)
2120 if (TREE_CODE (decl) == SSA_NAME)
2122 /* We often try to use the SSA_NAME, instead of its underlying
2123 decl, to get type information and guide decisions, to avoid
2124 differences of behavior between anonymous and named
2125 variables, but in this one case we have to go for the actual
2126 variable if there is one. The main reason is that, at least
2127 at -O0, we want to place user variables on the stack, but we
2128 don't mind using pseudos for anonymous or ignored temps.
2129 Should we take the SSA_NAME, we'd conclude all SSA_NAMEs
2130 should go in pseudos, whereas their corresponding variables
2131 might have to go on the stack. So, disregarding the decl
2132 here would negatively impact debug info at -O0, enable
2133 coalescing between SSA_NAMEs that ought to get different
2134 stack/pseudo assignments, and get the incoming argument
2135 processing thoroughly confused by PARM_DECLs expected to live
2136 in stack slots but assigned to pseudos. */
2137 if (!SSA_NAME_VAR (decl))
2138 return TYPE_MODE (TREE_TYPE (decl)) != BLKmode
2139 && !(flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)));
2141 decl = SSA_NAME_VAR (decl);
2144 /* Honor volatile. */
2145 if (TREE_SIDE_EFFECTS (decl))
2146 return false;
2148 /* Honor addressability. */
2149 if (TREE_ADDRESSABLE (decl))
2150 return false;
2152 /* RESULT_DECLs are a bit special in that they're assigned without
2153 regard to use_register_for_decl, but we generally only store in
2154 them. If we coalesce their SSA NAMEs, we'd better return a
2155 result that matches the assignment in expand_function_start. */
2156 if (TREE_CODE (decl) == RESULT_DECL)
2158 /* If it's not an aggregate, we're going to use a REG or a
2159 PARALLEL containing a REG. */
2160 if (!aggregate_value_p (decl, current_function_decl))
2161 return true;
2163 /* If expand_function_start determines the return value, we'll
2164 use MEM if it's not by reference. */
2165 if (cfun->returns_pcc_struct
2166 || (targetm.calls.struct_value_rtx
2167 (TREE_TYPE (current_function_decl), 1)))
2168 return DECL_BY_REFERENCE (decl);
2170 /* Otherwise, we're taking an extra all.function_result_decl
2171 argument. It's set up in assign_parms_augmented_arg_list,
2172 under the (negated) conditions above, and then it's used to
2173 set up the RESULT_DECL rtl in assign_params, after looping
2174 over all parameters. Now, if the RESULT_DECL is not by
2175 reference, we'll use a MEM either way. */
2176 if (!DECL_BY_REFERENCE (decl))
2177 return false;
2179 /* Otherwise, if RESULT_DECL is DECL_BY_REFERENCE, it will take
2180 the function_result_decl's assignment. Since it's a pointer,
2181 we can short-circuit a number of the tests below, and we must
2182 duplicat e them because we don't have the
2183 function_result_decl to test. */
2184 if (!targetm.calls.allocate_stack_slots_for_args ())
2185 return true;
2186 /* We don't set DECL_IGNORED_P for the function_result_decl. */
2187 if (optimize)
2188 return true;
2189 /* We don't set DECL_REGISTER for the function_result_decl. */
2190 return false;
2193 /* Decl is implicitly addressible by bound stores and loads
2194 if it is an aggregate holding bounds. */
2195 if (chkp_function_instrumented_p (current_function_decl)
2196 && TREE_TYPE (decl)
2197 && !BOUNDED_P (decl)
2198 && chkp_type_has_pointer (TREE_TYPE (decl)))
2199 return false;
2201 /* Only register-like things go in registers. */
2202 if (DECL_MODE (decl) == BLKmode)
2203 return false;
2205 /* If -ffloat-store specified, don't put explicit float variables
2206 into registers. */
2207 /* ??? This should be checked after DECL_ARTIFICIAL, but tree-ssa
2208 propagates values across these stores, and it probably shouldn't. */
2209 if (flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)))
2210 return false;
2212 if (!targetm.calls.allocate_stack_slots_for_args ())
2213 return true;
2215 /* If we're not interested in tracking debugging information for
2216 this decl, then we can certainly put it in a register. */
2217 if (DECL_IGNORED_P (decl))
2218 return true;
2220 if (optimize)
2221 return true;
2223 if (!DECL_REGISTER (decl))
2224 return false;
2226 /* When not optimizing, disregard register keyword for types that
2227 could have methods, otherwise the methods won't be callable from
2228 the debugger. */
2229 if (RECORD_OR_UNION_TYPE_P (TREE_TYPE (decl)))
2230 return false;
2232 return true;
2235 /* Structures to communicate between the subroutines of assign_parms.
2236 The first holds data persistent across all parameters, the second
2237 is cleared out for each parameter. */
2239 struct assign_parm_data_all
2241 /* When INIT_CUMULATIVE_ARGS gets revamped, allocating CUMULATIVE_ARGS
2242 should become a job of the target or otherwise encapsulated. */
2243 CUMULATIVE_ARGS args_so_far_v;
2244 cumulative_args_t args_so_far;
2245 struct args_size stack_args_size;
2246 tree function_result_decl;
2247 tree orig_fnargs;
2248 rtx_insn *first_conversion_insn;
2249 rtx_insn *last_conversion_insn;
2250 HOST_WIDE_INT pretend_args_size;
2251 HOST_WIDE_INT extra_pretend_bytes;
2252 int reg_parm_stack_space;
2255 struct assign_parm_data_one
2257 tree nominal_type;
2258 tree passed_type;
2259 rtx entry_parm;
2260 rtx stack_parm;
2261 machine_mode nominal_mode;
2262 machine_mode passed_mode;
2263 machine_mode promoted_mode;
2264 struct locate_and_pad_arg_data locate;
2265 int partial;
2266 BOOL_BITFIELD named_arg : 1;
2267 BOOL_BITFIELD passed_pointer : 1;
2268 BOOL_BITFIELD on_stack : 1;
2269 BOOL_BITFIELD loaded_in_reg : 1;
2272 struct bounds_parm_data
2274 assign_parm_data_one parm_data;
2275 tree bounds_parm;
2276 tree ptr_parm;
2277 rtx ptr_entry;
2278 int bound_no;
2281 /* A subroutine of assign_parms. Initialize ALL. */
2283 static void
2284 assign_parms_initialize_all (struct assign_parm_data_all *all)
2286 tree fntype ATTRIBUTE_UNUSED;
2288 memset (all, 0, sizeof (*all));
2290 fntype = TREE_TYPE (current_function_decl);
2292 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
2293 INIT_CUMULATIVE_INCOMING_ARGS (all->args_so_far_v, fntype, NULL_RTX);
2294 #else
2295 INIT_CUMULATIVE_ARGS (all->args_so_far_v, fntype, NULL_RTX,
2296 current_function_decl, -1);
2297 #endif
2298 all->args_so_far = pack_cumulative_args (&all->args_so_far_v);
2300 #ifdef INCOMING_REG_PARM_STACK_SPACE
2301 all->reg_parm_stack_space
2302 = INCOMING_REG_PARM_STACK_SPACE (current_function_decl);
2303 #endif
2306 /* If ARGS contains entries with complex types, split the entry into two
2307 entries of the component type. Return a new list of substitutions are
2308 needed, else the old list. */
2310 static void
2311 split_complex_args (vec<tree> *args)
2313 unsigned i;
2314 tree p;
2316 FOR_EACH_VEC_ELT (*args, i, p)
2318 tree type = TREE_TYPE (p);
2319 if (TREE_CODE (type) == COMPLEX_TYPE
2320 && targetm.calls.split_complex_arg (type))
2322 tree decl;
2323 tree subtype = TREE_TYPE (type);
2324 bool addressable = TREE_ADDRESSABLE (p);
2326 /* Rewrite the PARM_DECL's type with its component. */
2327 p = copy_node (p);
2328 TREE_TYPE (p) = subtype;
2329 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
2330 SET_DECL_MODE (p, VOIDmode);
2331 DECL_SIZE (p) = NULL;
2332 DECL_SIZE_UNIT (p) = NULL;
2333 /* If this arg must go in memory, put it in a pseudo here.
2334 We can't allow it to go in memory as per normal parms,
2335 because the usual place might not have the imag part
2336 adjacent to the real part. */
2337 DECL_ARTIFICIAL (p) = addressable;
2338 DECL_IGNORED_P (p) = addressable;
2339 TREE_ADDRESSABLE (p) = 0;
2340 layout_decl (p, 0);
2341 (*args)[i] = p;
2343 /* Build a second synthetic decl. */
2344 decl = build_decl (EXPR_LOCATION (p),
2345 PARM_DECL, NULL_TREE, subtype);
2346 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
2347 DECL_ARTIFICIAL (decl) = addressable;
2348 DECL_IGNORED_P (decl) = addressable;
2349 layout_decl (decl, 0);
2350 args->safe_insert (++i, decl);
2355 /* A subroutine of assign_parms. Adjust the parameter list to incorporate
2356 the hidden struct return argument, and (abi willing) complex args.
2357 Return the new parameter list. */
2359 static vec<tree>
2360 assign_parms_augmented_arg_list (struct assign_parm_data_all *all)
2362 tree fndecl = current_function_decl;
2363 tree fntype = TREE_TYPE (fndecl);
2364 vec<tree> fnargs = vNULL;
2365 tree arg;
2367 for (arg = DECL_ARGUMENTS (fndecl); arg; arg = DECL_CHAIN (arg))
2368 fnargs.safe_push (arg);
2370 all->orig_fnargs = DECL_ARGUMENTS (fndecl);
2372 /* If struct value address is treated as the first argument, make it so. */
2373 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
2374 && ! cfun->returns_pcc_struct
2375 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
2377 tree type = build_pointer_type (TREE_TYPE (fntype));
2378 tree decl;
2380 decl = build_decl (DECL_SOURCE_LOCATION (fndecl),
2381 PARM_DECL, get_identifier (".result_ptr"), type);
2382 DECL_ARG_TYPE (decl) = type;
2383 DECL_ARTIFICIAL (decl) = 1;
2384 DECL_NAMELESS (decl) = 1;
2385 TREE_CONSTANT (decl) = 1;
2386 /* We don't set DECL_IGNORED_P or DECL_REGISTER here. If this
2387 changes, the end of the RESULT_DECL handling block in
2388 use_register_for_decl must be adjusted to match. */
2390 DECL_CHAIN (decl) = all->orig_fnargs;
2391 all->orig_fnargs = decl;
2392 fnargs.safe_insert (0, decl);
2394 all->function_result_decl = decl;
2396 /* If function is instrumented then bounds of the
2397 passed structure address is the second argument. */
2398 if (chkp_function_instrumented_p (fndecl))
2400 decl = build_decl (DECL_SOURCE_LOCATION (fndecl),
2401 PARM_DECL, get_identifier (".result_bnd"),
2402 pointer_bounds_type_node);
2403 DECL_ARG_TYPE (decl) = pointer_bounds_type_node;
2404 DECL_ARTIFICIAL (decl) = 1;
2405 DECL_NAMELESS (decl) = 1;
2406 TREE_CONSTANT (decl) = 1;
2408 DECL_CHAIN (decl) = DECL_CHAIN (all->orig_fnargs);
2409 DECL_CHAIN (all->orig_fnargs) = decl;
2410 fnargs.safe_insert (1, decl);
2414 /* If the target wants to split complex arguments into scalars, do so. */
2415 if (targetm.calls.split_complex_arg)
2416 split_complex_args (&fnargs);
2418 return fnargs;
2421 /* A subroutine of assign_parms. Examine PARM and pull out type and mode
2422 data for the parameter. Incorporate ABI specifics such as pass-by-
2423 reference and type promotion. */
2425 static void
2426 assign_parm_find_data_types (struct assign_parm_data_all *all, tree parm,
2427 struct assign_parm_data_one *data)
2429 tree nominal_type, passed_type;
2430 machine_mode nominal_mode, passed_mode, promoted_mode;
2431 int unsignedp;
2433 memset (data, 0, sizeof (*data));
2435 /* NAMED_ARG is a misnomer. We really mean 'non-variadic'. */
2436 if (!cfun->stdarg)
2437 data->named_arg = 1; /* No variadic parms. */
2438 else if (DECL_CHAIN (parm))
2439 data->named_arg = 1; /* Not the last non-variadic parm. */
2440 else if (targetm.calls.strict_argument_naming (all->args_so_far))
2441 data->named_arg = 1; /* Only variadic ones are unnamed. */
2442 else
2443 data->named_arg = 0; /* Treat as variadic. */
2445 nominal_type = TREE_TYPE (parm);
2446 passed_type = DECL_ARG_TYPE (parm);
2448 /* Look out for errors propagating this far. Also, if the parameter's
2449 type is void then its value doesn't matter. */
2450 if (TREE_TYPE (parm) == error_mark_node
2451 /* This can happen after weird syntax errors
2452 or if an enum type is defined among the parms. */
2453 || TREE_CODE (parm) != PARM_DECL
2454 || passed_type == NULL
2455 || VOID_TYPE_P (nominal_type))
2457 nominal_type = passed_type = void_type_node;
2458 nominal_mode = passed_mode = promoted_mode = VOIDmode;
2459 goto egress;
2462 /* Find mode of arg as it is passed, and mode of arg as it should be
2463 during execution of this function. */
2464 passed_mode = TYPE_MODE (passed_type);
2465 nominal_mode = TYPE_MODE (nominal_type);
2467 /* If the parm is to be passed as a transparent union or record, use the
2468 type of the first field for the tests below. We have already verified
2469 that the modes are the same. */
2470 if ((TREE_CODE (passed_type) == UNION_TYPE
2471 || TREE_CODE (passed_type) == RECORD_TYPE)
2472 && TYPE_TRANSPARENT_AGGR (passed_type))
2473 passed_type = TREE_TYPE (first_field (passed_type));
2475 /* See if this arg was passed by invisible reference. */
2476 if (pass_by_reference (&all->args_so_far_v, passed_mode,
2477 passed_type, data->named_arg))
2479 passed_type = nominal_type = build_pointer_type (passed_type);
2480 data->passed_pointer = true;
2481 passed_mode = nominal_mode = TYPE_MODE (nominal_type);
2484 /* Find mode as it is passed by the ABI. */
2485 unsignedp = TYPE_UNSIGNED (passed_type);
2486 promoted_mode = promote_function_mode (passed_type, passed_mode, &unsignedp,
2487 TREE_TYPE (current_function_decl), 0);
2489 egress:
2490 data->nominal_type = nominal_type;
2491 data->passed_type = passed_type;
2492 data->nominal_mode = nominal_mode;
2493 data->passed_mode = passed_mode;
2494 data->promoted_mode = promoted_mode;
2497 /* A subroutine of assign_parms. Invoke setup_incoming_varargs. */
2499 static void
2500 assign_parms_setup_varargs (struct assign_parm_data_all *all,
2501 struct assign_parm_data_one *data, bool no_rtl)
2503 int varargs_pretend_bytes = 0;
2505 targetm.calls.setup_incoming_varargs (all->args_so_far,
2506 data->promoted_mode,
2507 data->passed_type,
2508 &varargs_pretend_bytes, no_rtl);
2510 /* If the back-end has requested extra stack space, record how much is
2511 needed. Do not change pretend_args_size otherwise since it may be
2512 nonzero from an earlier partial argument. */
2513 if (varargs_pretend_bytes > 0)
2514 all->pretend_args_size = varargs_pretend_bytes;
2517 /* A subroutine of assign_parms. Set DATA->ENTRY_PARM corresponding to
2518 the incoming location of the current parameter. */
2520 static void
2521 assign_parm_find_entry_rtl (struct assign_parm_data_all *all,
2522 struct assign_parm_data_one *data)
2524 HOST_WIDE_INT pretend_bytes = 0;
2525 rtx entry_parm;
2526 bool in_regs;
2528 if (data->promoted_mode == VOIDmode)
2530 data->entry_parm = data->stack_parm = const0_rtx;
2531 return;
2534 targetm.calls.warn_parameter_passing_abi (all->args_so_far,
2535 data->passed_type);
2537 entry_parm = targetm.calls.function_incoming_arg (all->args_so_far,
2538 data->promoted_mode,
2539 data->passed_type,
2540 data->named_arg);
2542 if (entry_parm == 0)
2543 data->promoted_mode = data->passed_mode;
2545 /* Determine parm's home in the stack, in case it arrives in the stack
2546 or we should pretend it did. Compute the stack position and rtx where
2547 the argument arrives and its size.
2549 There is one complexity here: If this was a parameter that would
2550 have been passed in registers, but wasn't only because it is
2551 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2552 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2553 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of 0
2554 as it was the previous time. */
2555 in_regs = (entry_parm != 0) || POINTER_BOUNDS_TYPE_P (data->passed_type);
2556 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2557 in_regs = true;
2558 #endif
2559 if (!in_regs && !data->named_arg)
2561 if (targetm.calls.pretend_outgoing_varargs_named (all->args_so_far))
2563 rtx tem;
2564 tem = targetm.calls.function_incoming_arg (all->args_so_far,
2565 data->promoted_mode,
2566 data->passed_type, true);
2567 in_regs = tem != NULL;
2571 /* If this parameter was passed both in registers and in the stack, use
2572 the copy on the stack. */
2573 if (targetm.calls.must_pass_in_stack (data->promoted_mode,
2574 data->passed_type))
2575 entry_parm = 0;
2577 if (entry_parm)
2579 int partial;
2581 partial = targetm.calls.arg_partial_bytes (all->args_so_far,
2582 data->promoted_mode,
2583 data->passed_type,
2584 data->named_arg);
2585 data->partial = partial;
2587 /* The caller might already have allocated stack space for the
2588 register parameters. */
2589 if (partial != 0 && all->reg_parm_stack_space == 0)
2591 /* Part of this argument is passed in registers and part
2592 is passed on the stack. Ask the prologue code to extend
2593 the stack part so that we can recreate the full value.
2595 PRETEND_BYTES is the size of the registers we need to store.
2596 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
2597 stack space that the prologue should allocate.
2599 Internally, gcc assumes that the argument pointer is aligned
2600 to STACK_BOUNDARY bits. This is used both for alignment
2601 optimizations (see init_emit) and to locate arguments that are
2602 aligned to more than PARM_BOUNDARY bits. We must preserve this
2603 invariant by rounding CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to
2604 a stack boundary. */
2606 /* We assume at most one partial arg, and it must be the first
2607 argument on the stack. */
2608 gcc_assert (!all->extra_pretend_bytes && !all->pretend_args_size);
2610 pretend_bytes = partial;
2611 all->pretend_args_size = CEIL_ROUND (pretend_bytes, STACK_BYTES);
2613 /* We want to align relative to the actual stack pointer, so
2614 don't include this in the stack size until later. */
2615 all->extra_pretend_bytes = all->pretend_args_size;
2619 locate_and_pad_parm (data->promoted_mode, data->passed_type, in_regs,
2620 all->reg_parm_stack_space,
2621 entry_parm ? data->partial : 0, current_function_decl,
2622 &all->stack_args_size, &data->locate);
2624 /* Update parm_stack_boundary if this parameter is passed in the
2625 stack. */
2626 if (!in_regs && crtl->parm_stack_boundary < data->locate.boundary)
2627 crtl->parm_stack_boundary = data->locate.boundary;
2629 /* Adjust offsets to include the pretend args. */
2630 pretend_bytes = all->extra_pretend_bytes - pretend_bytes;
2631 data->locate.slot_offset.constant += pretend_bytes;
2632 data->locate.offset.constant += pretend_bytes;
2634 data->entry_parm = entry_parm;
2637 /* A subroutine of assign_parms. If there is actually space on the stack
2638 for this parm, count it in stack_args_size and return true. */
2640 static bool
2641 assign_parm_is_stack_parm (struct assign_parm_data_all *all,
2642 struct assign_parm_data_one *data)
2644 /* Bounds are never passed on the stack to keep compatibility
2645 with not instrumented code. */
2646 if (POINTER_BOUNDS_TYPE_P (data->passed_type))
2647 return false;
2648 /* Trivially true if we've no incoming register. */
2649 else if (data->entry_parm == NULL)
2651 /* Also true if we're partially in registers and partially not,
2652 since we've arranged to drop the entire argument on the stack. */
2653 else if (data->partial != 0)
2655 /* Also true if the target says that it's passed in both registers
2656 and on the stack. */
2657 else if (GET_CODE (data->entry_parm) == PARALLEL
2658 && XEXP (XVECEXP (data->entry_parm, 0, 0), 0) == NULL_RTX)
2660 /* Also true if the target says that there's stack allocated for
2661 all register parameters. */
2662 else if (all->reg_parm_stack_space > 0)
2664 /* Otherwise, no, this parameter has no ABI defined stack slot. */
2665 else
2666 return false;
2668 all->stack_args_size.constant += data->locate.size.constant;
2669 if (data->locate.size.var)
2670 ADD_PARM_SIZE (all->stack_args_size, data->locate.size.var);
2672 return true;
2675 /* A subroutine of assign_parms. Given that this parameter is allocated
2676 stack space by the ABI, find it. */
2678 static void
2679 assign_parm_find_stack_rtl (tree parm, struct assign_parm_data_one *data)
2681 rtx offset_rtx, stack_parm;
2682 unsigned int align, boundary;
2684 /* If we're passing this arg using a reg, make its stack home the
2685 aligned stack slot. */
2686 if (data->entry_parm)
2687 offset_rtx = ARGS_SIZE_RTX (data->locate.slot_offset);
2688 else
2689 offset_rtx = ARGS_SIZE_RTX (data->locate.offset);
2691 stack_parm = crtl->args.internal_arg_pointer;
2692 if (offset_rtx != const0_rtx)
2693 stack_parm = gen_rtx_PLUS (Pmode, stack_parm, offset_rtx);
2694 stack_parm = gen_rtx_MEM (data->promoted_mode, stack_parm);
2696 if (!data->passed_pointer)
2698 set_mem_attributes (stack_parm, parm, 1);
2699 /* set_mem_attributes could set MEM_SIZE to the passed mode's size,
2700 while promoted mode's size is needed. */
2701 if (data->promoted_mode != BLKmode
2702 && data->promoted_mode != DECL_MODE (parm))
2704 set_mem_size (stack_parm, GET_MODE_SIZE (data->promoted_mode));
2705 if (MEM_EXPR (stack_parm) && MEM_OFFSET_KNOWN_P (stack_parm))
2707 int offset = subreg_lowpart_offset (DECL_MODE (parm),
2708 data->promoted_mode);
2709 if (offset)
2710 set_mem_offset (stack_parm, MEM_OFFSET (stack_parm) - offset);
2715 boundary = data->locate.boundary;
2716 align = BITS_PER_UNIT;
2718 /* If we're padding upward, we know that the alignment of the slot
2719 is TARGET_FUNCTION_ARG_BOUNDARY. If we're using slot_offset, we're
2720 intentionally forcing upward padding. Otherwise we have to come
2721 up with a guess at the alignment based on OFFSET_RTX. */
2722 if (data->locate.where_pad != PAD_DOWNWARD || data->entry_parm)
2723 align = boundary;
2724 else if (CONST_INT_P (offset_rtx))
2726 align = INTVAL (offset_rtx) * BITS_PER_UNIT | boundary;
2727 align = least_bit_hwi (align);
2729 set_mem_align (stack_parm, align);
2731 if (data->entry_parm)
2732 set_reg_attrs_for_parm (data->entry_parm, stack_parm);
2734 data->stack_parm = stack_parm;
2737 /* A subroutine of assign_parms. Adjust DATA->ENTRY_RTL such that it's
2738 always valid and contiguous. */
2740 static void
2741 assign_parm_adjust_entry_rtl (struct assign_parm_data_one *data)
2743 rtx entry_parm = data->entry_parm;
2744 rtx stack_parm = data->stack_parm;
2746 /* If this parm was passed part in regs and part in memory, pretend it
2747 arrived entirely in memory by pushing the register-part onto the stack.
2748 In the special case of a DImode or DFmode that is split, we could put
2749 it together in a pseudoreg directly, but for now that's not worth
2750 bothering with. */
2751 if (data->partial != 0)
2753 /* Handle calls that pass values in multiple non-contiguous
2754 locations. The Irix 6 ABI has examples of this. */
2755 if (GET_CODE (entry_parm) == PARALLEL)
2756 emit_group_store (validize_mem (copy_rtx (stack_parm)), entry_parm,
2757 data->passed_type,
2758 int_size_in_bytes (data->passed_type));
2759 else
2761 gcc_assert (data->partial % UNITS_PER_WORD == 0);
2762 move_block_from_reg (REGNO (entry_parm),
2763 validize_mem (copy_rtx (stack_parm)),
2764 data->partial / UNITS_PER_WORD);
2767 entry_parm = stack_parm;
2770 /* If we didn't decide this parm came in a register, by default it came
2771 on the stack. */
2772 else if (entry_parm == NULL)
2773 entry_parm = stack_parm;
2775 /* When an argument is passed in multiple locations, we can't make use
2776 of this information, but we can save some copying if the whole argument
2777 is passed in a single register. */
2778 else if (GET_CODE (entry_parm) == PARALLEL
2779 && data->nominal_mode != BLKmode
2780 && data->passed_mode != BLKmode)
2782 size_t i, len = XVECLEN (entry_parm, 0);
2784 for (i = 0; i < len; i++)
2785 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
2786 && REG_P (XEXP (XVECEXP (entry_parm, 0, i), 0))
2787 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
2788 == data->passed_mode)
2789 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
2791 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
2792 break;
2796 data->entry_parm = entry_parm;
2799 /* A subroutine of assign_parms. Reconstitute any values which were
2800 passed in multiple registers and would fit in a single register. */
2802 static void
2803 assign_parm_remove_parallels (struct assign_parm_data_one *data)
2805 rtx entry_parm = data->entry_parm;
2807 /* Convert the PARALLEL to a REG of the same mode as the parallel.
2808 This can be done with register operations rather than on the
2809 stack, even if we will store the reconstituted parameter on the
2810 stack later. */
2811 if (GET_CODE (entry_parm) == PARALLEL && GET_MODE (entry_parm) != BLKmode)
2813 rtx parmreg = gen_reg_rtx (GET_MODE (entry_parm));
2814 emit_group_store (parmreg, entry_parm, data->passed_type,
2815 GET_MODE_SIZE (GET_MODE (entry_parm)));
2816 entry_parm = parmreg;
2819 data->entry_parm = entry_parm;
2822 /* A subroutine of assign_parms. Adjust DATA->STACK_RTL such that it's
2823 always valid and properly aligned. */
2825 static void
2826 assign_parm_adjust_stack_rtl (struct assign_parm_data_one *data)
2828 rtx stack_parm = data->stack_parm;
2830 /* If we can't trust the parm stack slot to be aligned enough for its
2831 ultimate type, don't use that slot after entry. We'll make another
2832 stack slot, if we need one. */
2833 if (stack_parm
2834 && ((STRICT_ALIGNMENT
2835 && GET_MODE_ALIGNMENT (data->nominal_mode) > MEM_ALIGN (stack_parm))
2836 || (data->nominal_type
2837 && TYPE_ALIGN (data->nominal_type) > MEM_ALIGN (stack_parm)
2838 && MEM_ALIGN (stack_parm) < PREFERRED_STACK_BOUNDARY)))
2839 stack_parm = NULL;
2841 /* If parm was passed in memory, and we need to convert it on entry,
2842 don't store it back in that same slot. */
2843 else if (data->entry_parm == stack_parm
2844 && data->nominal_mode != BLKmode
2845 && data->nominal_mode != data->passed_mode)
2846 stack_parm = NULL;
2848 /* If stack protection is in effect for this function, don't leave any
2849 pointers in their passed stack slots. */
2850 else if (crtl->stack_protect_guard
2851 && (flag_stack_protect == 2
2852 || data->passed_pointer
2853 || POINTER_TYPE_P (data->nominal_type)))
2854 stack_parm = NULL;
2856 data->stack_parm = stack_parm;
2859 /* A subroutine of assign_parms. Return true if the current parameter
2860 should be stored as a BLKmode in the current frame. */
2862 static bool
2863 assign_parm_setup_block_p (struct assign_parm_data_one *data)
2865 if (data->nominal_mode == BLKmode)
2866 return true;
2867 if (GET_MODE (data->entry_parm) == BLKmode)
2868 return true;
2870 #ifdef BLOCK_REG_PADDING
2871 /* Only assign_parm_setup_block knows how to deal with register arguments
2872 that are padded at the least significant end. */
2873 if (REG_P (data->entry_parm)
2874 && GET_MODE_SIZE (data->promoted_mode) < UNITS_PER_WORD
2875 && (BLOCK_REG_PADDING (data->passed_mode, data->passed_type, 1)
2876 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
2877 return true;
2878 #endif
2880 return false;
2883 /* A subroutine of assign_parms. Arrange for the parameter to be
2884 present and valid in DATA->STACK_RTL. */
2886 static void
2887 assign_parm_setup_block (struct assign_parm_data_all *all,
2888 tree parm, struct assign_parm_data_one *data)
2890 rtx entry_parm = data->entry_parm;
2891 rtx stack_parm = data->stack_parm;
2892 rtx target_reg = NULL_RTX;
2893 bool in_conversion_seq = false;
2894 HOST_WIDE_INT size;
2895 HOST_WIDE_INT size_stored;
2897 if (GET_CODE (entry_parm) == PARALLEL)
2898 entry_parm = emit_group_move_into_temps (entry_parm);
2900 /* If we want the parameter in a pseudo, don't use a stack slot. */
2901 if (is_gimple_reg (parm) && use_register_for_decl (parm))
2903 tree def = ssa_default_def (cfun, parm);
2904 gcc_assert (def);
2905 machine_mode mode = promote_ssa_mode (def, NULL);
2906 rtx reg = gen_reg_rtx (mode);
2907 if (GET_CODE (reg) != CONCAT)
2908 stack_parm = reg;
2909 else
2911 target_reg = reg;
2912 /* Avoid allocating a stack slot, if there isn't one
2913 preallocated by the ABI. It might seem like we should
2914 always prefer a pseudo, but converting between
2915 floating-point and integer modes goes through the stack
2916 on various machines, so it's better to use the reserved
2917 stack slot than to risk wasting it and allocating more
2918 for the conversion. */
2919 if (stack_parm == NULL_RTX)
2921 int save = generating_concat_p;
2922 generating_concat_p = 0;
2923 stack_parm = gen_reg_rtx (mode);
2924 generating_concat_p = save;
2927 data->stack_parm = NULL;
2930 size = int_size_in_bytes (data->passed_type);
2931 size_stored = CEIL_ROUND (size, UNITS_PER_WORD);
2932 if (stack_parm == 0)
2934 SET_DECL_ALIGN (parm, MAX (DECL_ALIGN (parm), BITS_PER_WORD));
2935 stack_parm = assign_stack_local (BLKmode, size_stored,
2936 DECL_ALIGN (parm));
2937 if (GET_MODE_SIZE (GET_MODE (entry_parm)) == size)
2938 PUT_MODE (stack_parm, GET_MODE (entry_parm));
2939 set_mem_attributes (stack_parm, parm, 1);
2942 /* If a BLKmode arrives in registers, copy it to a stack slot. Handle
2943 calls that pass values in multiple non-contiguous locations. */
2944 if (REG_P (entry_parm) || GET_CODE (entry_parm) == PARALLEL)
2946 rtx mem;
2948 /* Note that we will be storing an integral number of words.
2949 So we have to be careful to ensure that we allocate an
2950 integral number of words. We do this above when we call
2951 assign_stack_local if space was not allocated in the argument
2952 list. If it was, this will not work if PARM_BOUNDARY is not
2953 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2954 if it becomes a problem. Exception is when BLKmode arrives
2955 with arguments not conforming to word_mode. */
2957 if (data->stack_parm == 0)
2959 else if (GET_CODE (entry_parm) == PARALLEL)
2961 else
2962 gcc_assert (!size || !(PARM_BOUNDARY % BITS_PER_WORD));
2964 mem = validize_mem (copy_rtx (stack_parm));
2966 /* Handle values in multiple non-contiguous locations. */
2967 if (GET_CODE (entry_parm) == PARALLEL && !MEM_P (mem))
2968 emit_group_store (mem, entry_parm, data->passed_type, size);
2969 else if (GET_CODE (entry_parm) == PARALLEL)
2971 push_to_sequence2 (all->first_conversion_insn,
2972 all->last_conversion_insn);
2973 emit_group_store (mem, entry_parm, data->passed_type, size);
2974 all->first_conversion_insn = get_insns ();
2975 all->last_conversion_insn = get_last_insn ();
2976 end_sequence ();
2977 in_conversion_seq = true;
2980 else if (size == 0)
2983 /* If SIZE is that of a mode no bigger than a word, just use
2984 that mode's store operation. */
2985 else if (size <= UNITS_PER_WORD)
2987 unsigned int bits = size * BITS_PER_UNIT;
2988 machine_mode mode = int_mode_for_size (bits, 0).else_blk ();
2990 if (mode != BLKmode
2991 #ifdef BLOCK_REG_PADDING
2992 && (size == UNITS_PER_WORD
2993 || (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2994 != (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
2995 #endif
2998 rtx reg;
3000 /* We are really truncating a word_mode value containing
3001 SIZE bytes into a value of mode MODE. If such an
3002 operation requires no actual instructions, we can refer
3003 to the value directly in mode MODE, otherwise we must
3004 start with the register in word_mode and explicitly
3005 convert it. */
3006 if (targetm.truly_noop_truncation (size * BITS_PER_UNIT,
3007 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 == PAD_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 == PAD_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 == PAD_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 (partial_subreg_p (tempreg)
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))
3278 /* The argument is already sign/zero extended, so note it
3279 into the subreg. */
3280 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
3281 SUBREG_PROMOTED_SET (tempreg, unsignedp);
3284 /* TREE_USED gets set erroneously during expand_assignment. */
3285 save_tree_used = TREE_USED (parm);
3286 SET_DECL_RTL (parm, rtl);
3287 expand_assignment (parm, make_tree (data->nominal_type, tempreg), false);
3288 SET_DECL_RTL (parm, NULL_RTX);
3289 TREE_USED (parm) = save_tree_used;
3290 all->first_conversion_insn = get_insns ();
3291 all->last_conversion_insn = get_last_insn ();
3292 end_sequence ();
3294 did_conversion = true;
3296 else
3297 emit_move_insn (parmreg, validated_mem);
3299 /* If we were passed a pointer but the actual value can safely live
3300 in a register, retrieve it and use it directly. */
3301 if (data->passed_pointer && TYPE_MODE (TREE_TYPE (parm)) != BLKmode)
3303 /* We can't use nominal_mode, because it will have been set to
3304 Pmode above. We must use the actual mode of the parm. */
3305 if (use_register_for_decl (parm))
3307 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
3308 mark_user_reg (parmreg);
3310 else
3312 int align = STACK_SLOT_ALIGNMENT (TREE_TYPE (parm),
3313 TYPE_MODE (TREE_TYPE (parm)),
3314 TYPE_ALIGN (TREE_TYPE (parm)));
3315 parmreg
3316 = assign_stack_local (TYPE_MODE (TREE_TYPE (parm)),
3317 GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (parm))),
3318 align);
3319 set_mem_attributes (parmreg, parm, 1);
3322 /* We need to preserve an address based on VIRTUAL_STACK_VARS_REGNUM for
3323 the debug info in case it is not legitimate. */
3324 if (GET_MODE (parmreg) != GET_MODE (rtl))
3326 rtx tempreg = gen_reg_rtx (GET_MODE (rtl));
3327 int unsigned_p = TYPE_UNSIGNED (TREE_TYPE (parm));
3329 push_to_sequence2 (all->first_conversion_insn,
3330 all->last_conversion_insn);
3331 emit_move_insn (tempreg, rtl);
3332 tempreg = convert_to_mode (GET_MODE (parmreg), tempreg, unsigned_p);
3333 emit_move_insn (MEM_P (parmreg) ? copy_rtx (parmreg) : parmreg,
3334 tempreg);
3335 all->first_conversion_insn = get_insns ();
3336 all->last_conversion_insn = get_last_insn ();
3337 end_sequence ();
3339 did_conversion = true;
3341 else
3342 emit_move_insn (MEM_P (parmreg) ? copy_rtx (parmreg) : parmreg, rtl);
3344 rtl = parmreg;
3346 /* STACK_PARM is the pointer, not the parm, and PARMREG is
3347 now the parm. */
3348 data->stack_parm = NULL;
3351 set_parm_rtl (parm, rtl);
3353 /* Mark the register as eliminable if we did no conversion and it was
3354 copied from memory at a fixed offset, and the arg pointer was not
3355 copied to a pseudo-reg. If the arg pointer is a pseudo reg or the
3356 offset formed an invalid address, such memory-equivalences as we
3357 make here would screw up life analysis for it. */
3358 if (data->nominal_mode == data->passed_mode
3359 && !did_conversion
3360 && data->stack_parm != 0
3361 && MEM_P (data->stack_parm)
3362 && data->locate.offset.var == 0
3363 && reg_mentioned_p (virtual_incoming_args_rtx,
3364 XEXP (data->stack_parm, 0)))
3366 rtx_insn *linsn = get_last_insn ();
3367 rtx_insn *sinsn;
3368 rtx set;
3370 /* Mark complex types separately. */
3371 if (GET_CODE (parmreg) == CONCAT)
3373 scalar_mode submode = GET_MODE_INNER (GET_MODE (parmreg));
3374 int regnor = REGNO (XEXP (parmreg, 0));
3375 int regnoi = REGNO (XEXP (parmreg, 1));
3376 rtx stackr = adjust_address_nv (data->stack_parm, submode, 0);
3377 rtx stacki = adjust_address_nv (data->stack_parm, submode,
3378 GET_MODE_SIZE (submode));
3380 /* Scan backwards for the set of the real and
3381 imaginary parts. */
3382 for (sinsn = linsn; sinsn != 0;
3383 sinsn = prev_nonnote_insn (sinsn))
3385 set = single_set (sinsn);
3386 if (set == 0)
3387 continue;
3389 if (SET_DEST (set) == regno_reg_rtx [regnoi])
3390 set_unique_reg_note (sinsn, REG_EQUIV, stacki);
3391 else if (SET_DEST (set) == regno_reg_rtx [regnor])
3392 set_unique_reg_note (sinsn, REG_EQUIV, stackr);
3395 else
3396 set_dst_reg_note (linsn, REG_EQUIV, equiv_stack_parm, parmreg);
3399 /* For pointer data type, suggest pointer register. */
3400 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3401 mark_reg_pointer (parmreg,
3402 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
3405 /* A subroutine of assign_parms. Allocate stack space to hold the current
3406 parameter. Get it there. Perform all ABI specified conversions. */
3408 static void
3409 assign_parm_setup_stack (struct assign_parm_data_all *all, tree parm,
3410 struct assign_parm_data_one *data)
3412 /* Value must be stored in the stack slot STACK_PARM during function
3413 execution. */
3414 bool to_conversion = false;
3416 assign_parm_remove_parallels (data);
3418 if (data->promoted_mode != data->nominal_mode)
3420 /* Conversion is required. */
3421 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
3423 emit_move_insn (tempreg, validize_mem (copy_rtx (data->entry_parm)));
3425 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3426 to_conversion = true;
3428 data->entry_parm = convert_to_mode (data->nominal_mode, tempreg,
3429 TYPE_UNSIGNED (TREE_TYPE (parm)));
3431 if (data->stack_parm)
3433 int offset = subreg_lowpart_offset (data->nominal_mode,
3434 GET_MODE (data->stack_parm));
3435 /* ??? This may need a big-endian conversion on sparc64. */
3436 data->stack_parm
3437 = adjust_address (data->stack_parm, data->nominal_mode, 0);
3438 if (offset && MEM_OFFSET_KNOWN_P (data->stack_parm))
3439 set_mem_offset (data->stack_parm,
3440 MEM_OFFSET (data->stack_parm) + offset);
3444 if (data->entry_parm != data->stack_parm)
3446 rtx src, dest;
3448 if (data->stack_parm == 0)
3450 int align = STACK_SLOT_ALIGNMENT (data->passed_type,
3451 GET_MODE (data->entry_parm),
3452 TYPE_ALIGN (data->passed_type));
3453 data->stack_parm
3454 = assign_stack_local (GET_MODE (data->entry_parm),
3455 GET_MODE_SIZE (GET_MODE (data->entry_parm)),
3456 align);
3457 set_mem_attributes (data->stack_parm, parm, 1);
3460 dest = validize_mem (copy_rtx (data->stack_parm));
3461 src = validize_mem (copy_rtx (data->entry_parm));
3463 if (MEM_P (src))
3465 /* Use a block move to handle potentially misaligned entry_parm. */
3466 if (!to_conversion)
3467 push_to_sequence2 (all->first_conversion_insn,
3468 all->last_conversion_insn);
3469 to_conversion = true;
3471 emit_block_move (dest, src,
3472 GEN_INT (int_size_in_bytes (data->passed_type)),
3473 BLOCK_OP_NORMAL);
3475 else
3477 if (!REG_P (src))
3478 src = force_reg (GET_MODE (src), src);
3479 emit_move_insn (dest, src);
3483 if (to_conversion)
3485 all->first_conversion_insn = get_insns ();
3486 all->last_conversion_insn = get_last_insn ();
3487 end_sequence ();
3490 set_parm_rtl (parm, data->stack_parm);
3493 /* A subroutine of assign_parms. If the ABI splits complex arguments, then
3494 undo the frobbing that we did in assign_parms_augmented_arg_list. */
3496 static void
3497 assign_parms_unsplit_complex (struct assign_parm_data_all *all,
3498 vec<tree> fnargs)
3500 tree parm;
3501 tree orig_fnargs = all->orig_fnargs;
3502 unsigned i = 0;
3504 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm), ++i)
3506 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
3507 && targetm.calls.split_complex_arg (TREE_TYPE (parm)))
3509 rtx tmp, real, imag;
3510 scalar_mode inner = GET_MODE_INNER (DECL_MODE (parm));
3512 real = DECL_RTL (fnargs[i]);
3513 imag = DECL_RTL (fnargs[i + 1]);
3514 if (inner != GET_MODE (real))
3516 real = gen_lowpart_SUBREG (inner, real);
3517 imag = gen_lowpart_SUBREG (inner, imag);
3520 if (TREE_ADDRESSABLE (parm))
3522 rtx rmem, imem;
3523 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (parm));
3524 int align = STACK_SLOT_ALIGNMENT (TREE_TYPE (parm),
3525 DECL_MODE (parm),
3526 TYPE_ALIGN (TREE_TYPE (parm)));
3528 /* split_complex_arg put the real and imag parts in
3529 pseudos. Move them to memory. */
3530 tmp = assign_stack_local (DECL_MODE (parm), size, align);
3531 set_mem_attributes (tmp, parm, 1);
3532 rmem = adjust_address_nv (tmp, inner, 0);
3533 imem = adjust_address_nv (tmp, inner, GET_MODE_SIZE (inner));
3534 push_to_sequence2 (all->first_conversion_insn,
3535 all->last_conversion_insn);
3536 emit_move_insn (rmem, real);
3537 emit_move_insn (imem, imag);
3538 all->first_conversion_insn = get_insns ();
3539 all->last_conversion_insn = get_last_insn ();
3540 end_sequence ();
3542 else
3543 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
3544 set_parm_rtl (parm, tmp);
3546 real = DECL_INCOMING_RTL (fnargs[i]);
3547 imag = DECL_INCOMING_RTL (fnargs[i + 1]);
3548 if (inner != GET_MODE (real))
3550 real = gen_lowpart_SUBREG (inner, real);
3551 imag = gen_lowpart_SUBREG (inner, imag);
3553 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
3554 set_decl_incoming_rtl (parm, tmp, false);
3555 i++;
3560 /* Load bounds of PARM from bounds table. */
3561 static void
3562 assign_parm_load_bounds (struct assign_parm_data_one *data,
3563 tree parm,
3564 rtx entry,
3565 unsigned bound_no)
3567 bitmap_iterator bi;
3568 unsigned i, offs = 0;
3569 int bnd_no = -1;
3570 rtx slot = NULL, ptr = NULL;
3572 if (parm)
3574 bitmap slots;
3575 bitmap_obstack_initialize (NULL);
3576 slots = BITMAP_ALLOC (NULL);
3577 chkp_find_bound_slots (TREE_TYPE (parm), slots);
3578 EXECUTE_IF_SET_IN_BITMAP (slots, 0, i, bi)
3580 if (bound_no)
3581 bound_no--;
3582 else
3584 bnd_no = i;
3585 break;
3588 BITMAP_FREE (slots);
3589 bitmap_obstack_release (NULL);
3592 /* We may have bounds not associated with any pointer. */
3593 if (bnd_no != -1)
3594 offs = bnd_no * POINTER_SIZE / BITS_PER_UNIT;
3596 /* Find associated pointer. */
3597 if (bnd_no == -1)
3599 /* If bounds are not associated with any bounds,
3600 then it is passed in a register or special slot. */
3601 gcc_assert (data->entry_parm);
3602 ptr = const0_rtx;
3604 else if (MEM_P (entry))
3605 slot = adjust_address (entry, Pmode, offs);
3606 else if (REG_P (entry))
3607 ptr = gen_rtx_REG (Pmode, REGNO (entry) + bnd_no);
3608 else if (GET_CODE (entry) == PARALLEL)
3609 ptr = chkp_get_value_with_offs (entry, GEN_INT (offs));
3610 else
3611 gcc_unreachable ();
3612 data->entry_parm = targetm.calls.load_bounds_for_arg (slot, ptr,
3613 data->entry_parm);
3616 /* Assign RTL expressions to the function's bounds parameters BNDARGS. */
3618 static void
3619 assign_bounds (vec<bounds_parm_data> &bndargs,
3620 struct assign_parm_data_all &all,
3621 bool assign_regs, bool assign_special,
3622 bool assign_bt)
3624 unsigned i, pass;
3625 bounds_parm_data *pbdata;
3627 if (!bndargs.exists ())
3628 return;
3630 /* We make few passes to store input bounds. Firstly handle bounds
3631 passed in registers. After that we load bounds passed in special
3632 slots. Finally we load bounds from Bounds Table. */
3633 for (pass = 0; pass < 3; pass++)
3634 FOR_EACH_VEC_ELT (bndargs, i, pbdata)
3636 /* Pass 0 => regs only. */
3637 if (pass == 0
3638 && (!assign_regs
3639 ||(!pbdata->parm_data.entry_parm
3640 || GET_CODE (pbdata->parm_data.entry_parm) != REG)))
3641 continue;
3642 /* Pass 1 => slots only. */
3643 else if (pass == 1
3644 && (!assign_special
3645 || (!pbdata->parm_data.entry_parm
3646 || GET_CODE (pbdata->parm_data.entry_parm) == REG)))
3647 continue;
3648 /* Pass 2 => BT only. */
3649 else if (pass == 2
3650 && (!assign_bt
3651 || pbdata->parm_data.entry_parm))
3652 continue;
3654 if (!pbdata->parm_data.entry_parm
3655 || GET_CODE (pbdata->parm_data.entry_parm) != REG)
3656 assign_parm_load_bounds (&pbdata->parm_data, pbdata->ptr_parm,
3657 pbdata->ptr_entry, pbdata->bound_no);
3659 set_decl_incoming_rtl (pbdata->bounds_parm,
3660 pbdata->parm_data.entry_parm, false);
3662 if (assign_parm_setup_block_p (&pbdata->parm_data))
3663 assign_parm_setup_block (&all, pbdata->bounds_parm,
3664 &pbdata->parm_data);
3665 else if (pbdata->parm_data.passed_pointer
3666 || use_register_for_decl (pbdata->bounds_parm))
3667 assign_parm_setup_reg (&all, pbdata->bounds_parm,
3668 &pbdata->parm_data);
3669 else
3670 assign_parm_setup_stack (&all, pbdata->bounds_parm,
3671 &pbdata->parm_data);
3675 /* Assign RTL expressions to the function's parameters. This may involve
3676 copying them into registers and using those registers as the DECL_RTL. */
3678 static void
3679 assign_parms (tree fndecl)
3681 struct assign_parm_data_all all;
3682 tree parm;
3683 vec<tree> fnargs;
3684 unsigned i, bound_no = 0;
3685 tree last_arg = NULL;
3686 rtx last_arg_entry = NULL;
3687 vec<bounds_parm_data> bndargs = vNULL;
3688 bounds_parm_data bdata;
3690 crtl->args.internal_arg_pointer
3691 = targetm.calls.internal_arg_pointer ();
3693 assign_parms_initialize_all (&all);
3694 fnargs = assign_parms_augmented_arg_list (&all);
3696 FOR_EACH_VEC_ELT (fnargs, i, parm)
3698 struct assign_parm_data_one data;
3700 /* Extract the type of PARM; adjust it according to ABI. */
3701 assign_parm_find_data_types (&all, parm, &data);
3703 /* Early out for errors and void parameters. */
3704 if (data.passed_mode == VOIDmode)
3706 SET_DECL_RTL (parm, const0_rtx);
3707 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
3708 continue;
3711 /* Estimate stack alignment from parameter alignment. */
3712 if (SUPPORTS_STACK_ALIGNMENT)
3714 unsigned int align
3715 = targetm.calls.function_arg_boundary (data.promoted_mode,
3716 data.passed_type);
3717 align = MINIMUM_ALIGNMENT (data.passed_type, data.promoted_mode,
3718 align);
3719 if (TYPE_ALIGN (data.nominal_type) > align)
3720 align = MINIMUM_ALIGNMENT (data.nominal_type,
3721 TYPE_MODE (data.nominal_type),
3722 TYPE_ALIGN (data.nominal_type));
3723 if (crtl->stack_alignment_estimated < align)
3725 gcc_assert (!crtl->stack_realign_processed);
3726 crtl->stack_alignment_estimated = align;
3730 /* Find out where the parameter arrives in this function. */
3731 assign_parm_find_entry_rtl (&all, &data);
3733 /* Find out where stack space for this parameter might be. */
3734 if (assign_parm_is_stack_parm (&all, &data))
3736 assign_parm_find_stack_rtl (parm, &data);
3737 assign_parm_adjust_entry_rtl (&data);
3739 if (!POINTER_BOUNDS_TYPE_P (data.passed_type))
3741 /* Remember where last non bounds arg was passed in case
3742 we have to load associated bounds for it from Bounds
3743 Table. */
3744 last_arg = parm;
3745 last_arg_entry = data.entry_parm;
3746 bound_no = 0;
3748 /* Record permanently how this parm was passed. */
3749 if (data.passed_pointer)
3751 rtx incoming_rtl
3752 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data.passed_type)),
3753 data.entry_parm);
3754 set_decl_incoming_rtl (parm, incoming_rtl, true);
3756 else
3757 set_decl_incoming_rtl (parm, data.entry_parm, false);
3759 assign_parm_adjust_stack_rtl (&data);
3761 /* Bounds should be loaded in the particular order to
3762 have registers allocated correctly. Collect info about
3763 input bounds and load them later. */
3764 if (POINTER_BOUNDS_TYPE_P (data.passed_type))
3766 /* Expect bounds in instrumented functions only. */
3767 gcc_assert (chkp_function_instrumented_p (fndecl));
3769 bdata.parm_data = data;
3770 bdata.bounds_parm = parm;
3771 bdata.ptr_parm = last_arg;
3772 bdata.ptr_entry = last_arg_entry;
3773 bdata.bound_no = bound_no;
3774 bndargs.safe_push (bdata);
3776 else
3778 if (assign_parm_setup_block_p (&data))
3779 assign_parm_setup_block (&all, parm, &data);
3780 else if (data.passed_pointer || use_register_for_decl (parm))
3781 assign_parm_setup_reg (&all, parm, &data);
3782 else
3783 assign_parm_setup_stack (&all, parm, &data);
3786 if (cfun->stdarg && !DECL_CHAIN (parm))
3788 int pretend_bytes = 0;
3790 assign_parms_setup_varargs (&all, &data, false);
3792 if (chkp_function_instrumented_p (fndecl))
3794 /* We expect this is the last parm. Otherwise it is wrong
3795 to assign bounds right now. */
3796 gcc_assert (i == (fnargs.length () - 1));
3797 assign_bounds (bndargs, all, true, false, false);
3798 targetm.calls.setup_incoming_vararg_bounds (all.args_so_far,
3799 data.promoted_mode,
3800 data.passed_type,
3801 &pretend_bytes,
3802 false);
3803 assign_bounds (bndargs, all, false, true, true);
3804 bndargs.release ();
3808 /* Update info on where next arg arrives in registers. */
3809 targetm.calls.function_arg_advance (all.args_so_far, data.promoted_mode,
3810 data.passed_type, data.named_arg);
3812 if (POINTER_BOUNDS_TYPE_P (data.passed_type))
3813 bound_no++;
3816 assign_bounds (bndargs, all, true, true, true);
3817 bndargs.release ();
3819 if (targetm.calls.split_complex_arg)
3820 assign_parms_unsplit_complex (&all, fnargs);
3822 fnargs.release ();
3824 /* Output all parameter conversion instructions (possibly including calls)
3825 now that all parameters have been copied out of hard registers. */
3826 emit_insn (all.first_conversion_insn);
3828 /* Estimate reload stack alignment from scalar return mode. */
3829 if (SUPPORTS_STACK_ALIGNMENT)
3831 if (DECL_RESULT (fndecl))
3833 tree type = TREE_TYPE (DECL_RESULT (fndecl));
3834 machine_mode mode = TYPE_MODE (type);
3836 if (mode != BLKmode
3837 && mode != VOIDmode
3838 && !AGGREGATE_TYPE_P (type))
3840 unsigned int align = GET_MODE_ALIGNMENT (mode);
3841 if (crtl->stack_alignment_estimated < align)
3843 gcc_assert (!crtl->stack_realign_processed);
3844 crtl->stack_alignment_estimated = align;
3850 /* If we are receiving a struct value address as the first argument, set up
3851 the RTL for the function result. As this might require code to convert
3852 the transmitted address to Pmode, we do this here to ensure that possible
3853 preliminary conversions of the address have been emitted already. */
3854 if (all.function_result_decl)
3856 tree result = DECL_RESULT (current_function_decl);
3857 rtx addr = DECL_RTL (all.function_result_decl);
3858 rtx x;
3860 if (DECL_BY_REFERENCE (result))
3862 SET_DECL_VALUE_EXPR (result, all.function_result_decl);
3863 x = addr;
3865 else
3867 SET_DECL_VALUE_EXPR (result,
3868 build1 (INDIRECT_REF, TREE_TYPE (result),
3869 all.function_result_decl));
3870 addr = convert_memory_address (Pmode, addr);
3871 x = gen_rtx_MEM (DECL_MODE (result), addr);
3872 set_mem_attributes (x, result, 1);
3875 DECL_HAS_VALUE_EXPR_P (result) = 1;
3877 set_parm_rtl (result, x);
3880 /* We have aligned all the args, so add space for the pretend args. */
3881 crtl->args.pretend_args_size = all.pretend_args_size;
3882 all.stack_args_size.constant += all.extra_pretend_bytes;
3883 crtl->args.size = all.stack_args_size.constant;
3885 /* Adjust function incoming argument size for alignment and
3886 minimum length. */
3888 crtl->args.size = MAX (crtl->args.size, all.reg_parm_stack_space);
3889 crtl->args.size = CEIL_ROUND (crtl->args.size,
3890 PARM_BOUNDARY / BITS_PER_UNIT);
3892 if (ARGS_GROW_DOWNWARD)
3894 crtl->args.arg_offset_rtx
3895 = (all.stack_args_size.var == 0 ? GEN_INT (-all.stack_args_size.constant)
3896 : expand_expr (size_diffop (all.stack_args_size.var,
3897 size_int (-all.stack_args_size.constant)),
3898 NULL_RTX, VOIDmode, EXPAND_NORMAL));
3900 else
3901 crtl->args.arg_offset_rtx = ARGS_SIZE_RTX (all.stack_args_size);
3903 /* See how many bytes, if any, of its args a function should try to pop
3904 on return. */
3906 crtl->args.pops_args = targetm.calls.return_pops_args (fndecl,
3907 TREE_TYPE (fndecl),
3908 crtl->args.size);
3910 /* For stdarg.h function, save info about
3911 regs and stack space used by the named args. */
3913 crtl->args.info = all.args_so_far_v;
3915 /* Set the rtx used for the function return value. Put this in its
3916 own variable so any optimizers that need this information don't have
3917 to include tree.h. Do this here so it gets done when an inlined
3918 function gets output. */
3920 crtl->return_rtx
3921 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
3922 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
3924 /* If scalar return value was computed in a pseudo-reg, or was a named
3925 return value that got dumped to the stack, copy that to the hard
3926 return register. */
3927 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
3929 tree decl_result = DECL_RESULT (fndecl);
3930 rtx decl_rtl = DECL_RTL (decl_result);
3932 if (REG_P (decl_rtl)
3933 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
3934 : DECL_REGISTER (decl_result))
3936 rtx real_decl_rtl;
3938 real_decl_rtl = targetm.calls.function_value (TREE_TYPE (decl_result),
3939 fndecl, true);
3940 if (chkp_function_instrumented_p (fndecl))
3941 crtl->return_bnd
3942 = targetm.calls.chkp_function_value_bounds (TREE_TYPE (decl_result),
3943 fndecl, true);
3944 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
3945 /* The delay slot scheduler assumes that crtl->return_rtx
3946 holds the hard register containing the return value, not a
3947 temporary pseudo. */
3948 crtl->return_rtx = real_decl_rtl;
3953 /* A subroutine of gimplify_parameters, invoked via walk_tree.
3954 For all seen types, gimplify their sizes. */
3956 static tree
3957 gimplify_parm_type (tree *tp, int *walk_subtrees, void *data)
3959 tree t = *tp;
3961 *walk_subtrees = 0;
3962 if (TYPE_P (t))
3964 if (POINTER_TYPE_P (t))
3965 *walk_subtrees = 1;
3966 else if (TYPE_SIZE (t) && !TREE_CONSTANT (TYPE_SIZE (t))
3967 && !TYPE_SIZES_GIMPLIFIED (t))
3969 gimplify_type_sizes (t, (gimple_seq *) data);
3970 *walk_subtrees = 1;
3974 return NULL;
3977 /* Gimplify the parameter list for current_function_decl. This involves
3978 evaluating SAVE_EXPRs of variable sized parameters and generating code
3979 to implement callee-copies reference parameters. Returns a sequence of
3980 statements to add to the beginning of the function. */
3982 gimple_seq
3983 gimplify_parameters (void)
3985 struct assign_parm_data_all all;
3986 tree parm;
3987 gimple_seq stmts = NULL;
3988 vec<tree> fnargs;
3989 unsigned i;
3991 assign_parms_initialize_all (&all);
3992 fnargs = assign_parms_augmented_arg_list (&all);
3994 FOR_EACH_VEC_ELT (fnargs, i, parm)
3996 struct assign_parm_data_one data;
3998 /* Extract the type of PARM; adjust it according to ABI. */
3999 assign_parm_find_data_types (&all, parm, &data);
4001 /* Early out for errors and void parameters. */
4002 if (data.passed_mode == VOIDmode || DECL_SIZE (parm) == NULL)
4003 continue;
4005 /* Update info on where next arg arrives in registers. */
4006 targetm.calls.function_arg_advance (all.args_so_far, data.promoted_mode,
4007 data.passed_type, data.named_arg);
4009 /* ??? Once upon a time variable_size stuffed parameter list
4010 SAVE_EXPRs (amongst others) onto a pending sizes list. This
4011 turned out to be less than manageable in the gimple world.
4012 Now we have to hunt them down ourselves. */
4013 walk_tree_without_duplicates (&data.passed_type,
4014 gimplify_parm_type, &stmts);
4016 if (TREE_CODE (DECL_SIZE_UNIT (parm)) != INTEGER_CST)
4018 gimplify_one_sizepos (&DECL_SIZE (parm), &stmts);
4019 gimplify_one_sizepos (&DECL_SIZE_UNIT (parm), &stmts);
4022 if (data.passed_pointer)
4024 tree type = TREE_TYPE (data.passed_type);
4025 if (reference_callee_copied (&all.args_so_far_v, TYPE_MODE (type),
4026 type, data.named_arg))
4028 tree local, t;
4030 /* For constant-sized objects, this is trivial; for
4031 variable-sized objects, we have to play games. */
4032 if (TREE_CODE (DECL_SIZE_UNIT (parm)) == INTEGER_CST
4033 && !(flag_stack_check == GENERIC_STACK_CHECK
4034 && compare_tree_int (DECL_SIZE_UNIT (parm),
4035 STACK_CHECK_MAX_VAR_SIZE) > 0))
4037 local = create_tmp_var (type, get_name (parm));
4038 DECL_IGNORED_P (local) = 0;
4039 /* If PARM was addressable, move that flag over
4040 to the local copy, as its address will be taken,
4041 not the PARMs. Keep the parms address taken
4042 as we'll query that flag during gimplification. */
4043 if (TREE_ADDRESSABLE (parm))
4044 TREE_ADDRESSABLE (local) = 1;
4045 else if (TREE_CODE (type) == COMPLEX_TYPE
4046 || TREE_CODE (type) == VECTOR_TYPE)
4047 DECL_GIMPLE_REG_P (local) = 1;
4049 else
4051 tree ptr_type, addr;
4053 ptr_type = build_pointer_type (type);
4054 addr = create_tmp_reg (ptr_type, get_name (parm));
4055 DECL_IGNORED_P (addr) = 0;
4056 local = build_fold_indirect_ref (addr);
4058 t = build_alloca_call_expr (DECL_SIZE_UNIT (parm),
4059 DECL_ALIGN (parm),
4060 max_int_size_in_bytes (type));
4061 /* The call has been built for a variable-sized object. */
4062 CALL_ALLOCA_FOR_VAR_P (t) = 1;
4063 t = fold_convert (ptr_type, t);
4064 t = build2 (MODIFY_EXPR, TREE_TYPE (addr), addr, t);
4065 gimplify_and_add (t, &stmts);
4068 gimplify_assign (local, parm, &stmts);
4070 SET_DECL_VALUE_EXPR (parm, local);
4071 DECL_HAS_VALUE_EXPR_P (parm) = 1;
4076 fnargs.release ();
4078 return stmts;
4081 /* Compute the size and offset from the start of the stacked arguments for a
4082 parm passed in mode PASSED_MODE and with type TYPE.
4084 INITIAL_OFFSET_PTR points to the current offset into the stacked
4085 arguments.
4087 The starting offset and size for this parm are returned in
4088 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
4089 nonzero, the offset is that of stack slot, which is returned in
4090 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
4091 padding required from the initial offset ptr to the stack slot.
4093 IN_REGS is nonzero if the argument will be passed in registers. It will
4094 never be set if REG_PARM_STACK_SPACE is not defined.
4096 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
4097 for arguments which are passed in registers.
4099 FNDECL is the function in which the argument was defined.
4101 There are two types of rounding that are done. The first, controlled by
4102 TARGET_FUNCTION_ARG_BOUNDARY, forces the offset from the start of the
4103 argument list to be aligned to the specific boundary (in bits). This
4104 rounding affects the initial and starting offsets, but not the argument
4105 size.
4107 The second, controlled by TARGET_FUNCTION_ARG_PADDING and PARM_BOUNDARY,
4108 optionally rounds the size of the parm to PARM_BOUNDARY. The
4109 initial offset is not affected by this rounding, while the size always
4110 is and the starting offset may be. */
4112 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
4113 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
4114 callers pass in the total size of args so far as
4115 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
4117 void
4118 locate_and_pad_parm (machine_mode passed_mode, tree type, int in_regs,
4119 int reg_parm_stack_space, int partial,
4120 tree fndecl ATTRIBUTE_UNUSED,
4121 struct args_size *initial_offset_ptr,
4122 struct locate_and_pad_arg_data *locate)
4124 tree sizetree;
4125 pad_direction where_pad;
4126 unsigned int boundary, round_boundary;
4127 int part_size_in_regs;
4129 /* If we have found a stack parm before we reach the end of the
4130 area reserved for registers, skip that area. */
4131 if (! in_regs)
4133 if (reg_parm_stack_space > 0)
4135 if (initial_offset_ptr->var)
4137 initial_offset_ptr->var
4138 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
4139 ssize_int (reg_parm_stack_space));
4140 initial_offset_ptr->constant = 0;
4142 else if (initial_offset_ptr->constant < reg_parm_stack_space)
4143 initial_offset_ptr->constant = reg_parm_stack_space;
4147 part_size_in_regs = (reg_parm_stack_space == 0 ? partial : 0);
4149 sizetree = (type
4150 ? arg_size_in_bytes (type)
4151 : size_int (GET_MODE_SIZE (passed_mode)));
4152 where_pad = targetm.calls.function_arg_padding (passed_mode, type);
4153 boundary = targetm.calls.function_arg_boundary (passed_mode, type);
4154 round_boundary = targetm.calls.function_arg_round_boundary (passed_mode,
4155 type);
4156 locate->where_pad = where_pad;
4158 /* Alignment can't exceed MAX_SUPPORTED_STACK_ALIGNMENT. */
4159 if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
4160 boundary = MAX_SUPPORTED_STACK_ALIGNMENT;
4162 locate->boundary = boundary;
4164 if (SUPPORTS_STACK_ALIGNMENT)
4166 /* stack_alignment_estimated can't change after stack has been
4167 realigned. */
4168 if (crtl->stack_alignment_estimated < boundary)
4170 if (!crtl->stack_realign_processed)
4171 crtl->stack_alignment_estimated = boundary;
4172 else
4174 /* If stack is realigned and stack alignment value
4175 hasn't been finalized, it is OK not to increase
4176 stack_alignment_estimated. The bigger alignment
4177 requirement is recorded in stack_alignment_needed
4178 below. */
4179 gcc_assert (!crtl->stack_realign_finalized
4180 && crtl->stack_realign_needed);
4185 /* Remember if the outgoing parameter requires extra alignment on the
4186 calling function side. */
4187 if (crtl->stack_alignment_needed < boundary)
4188 crtl->stack_alignment_needed = boundary;
4189 if (crtl->preferred_stack_boundary < boundary)
4190 crtl->preferred_stack_boundary = boundary;
4192 if (ARGS_GROW_DOWNWARD)
4194 locate->slot_offset.constant = -initial_offset_ptr->constant;
4195 if (initial_offset_ptr->var)
4196 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
4197 initial_offset_ptr->var);
4200 tree s2 = sizetree;
4201 if (where_pad != PAD_NONE
4202 && (!tree_fits_uhwi_p (sizetree)
4203 || (tree_to_uhwi (sizetree) * BITS_PER_UNIT) % round_boundary))
4204 s2 = round_up (s2, round_boundary / BITS_PER_UNIT);
4205 SUB_PARM_SIZE (locate->slot_offset, s2);
4208 locate->slot_offset.constant += part_size_in_regs;
4210 if (!in_regs || reg_parm_stack_space > 0)
4211 pad_to_arg_alignment (&locate->slot_offset, boundary,
4212 &locate->alignment_pad);
4214 locate->size.constant = (-initial_offset_ptr->constant
4215 - locate->slot_offset.constant);
4216 if (initial_offset_ptr->var)
4217 locate->size.var = size_binop (MINUS_EXPR,
4218 size_binop (MINUS_EXPR,
4219 ssize_int (0),
4220 initial_offset_ptr->var),
4221 locate->slot_offset.var);
4223 /* Pad_below needs the pre-rounded size to know how much to pad
4224 below. */
4225 locate->offset = locate->slot_offset;
4226 if (where_pad == PAD_DOWNWARD)
4227 pad_below (&locate->offset, passed_mode, sizetree);
4230 else
4232 if (!in_regs || reg_parm_stack_space > 0)
4233 pad_to_arg_alignment (initial_offset_ptr, boundary,
4234 &locate->alignment_pad);
4235 locate->slot_offset = *initial_offset_ptr;
4237 #ifdef PUSH_ROUNDING
4238 if (passed_mode != BLKmode)
4239 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
4240 #endif
4242 /* Pad_below needs the pre-rounded size to know how much to pad below
4243 so this must be done before rounding up. */
4244 locate->offset = locate->slot_offset;
4245 if (where_pad == PAD_DOWNWARD)
4246 pad_below (&locate->offset, passed_mode, sizetree);
4248 if (where_pad != PAD_NONE
4249 && (!tree_fits_uhwi_p (sizetree)
4250 || (tree_to_uhwi (sizetree) * BITS_PER_UNIT) % round_boundary))
4251 sizetree = round_up (sizetree, round_boundary / BITS_PER_UNIT);
4253 ADD_PARM_SIZE (locate->size, sizetree);
4255 locate->size.constant -= part_size_in_regs;
4258 locate->offset.constant
4259 += targetm.calls.function_arg_offset (passed_mode, type);
4262 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
4263 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
4265 static void
4266 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
4267 struct args_size *alignment_pad)
4269 tree save_var = NULL_TREE;
4270 HOST_WIDE_INT save_constant = 0;
4271 int boundary_in_bytes = boundary / BITS_PER_UNIT;
4272 HOST_WIDE_INT sp_offset = STACK_POINTER_OFFSET;
4274 #ifdef SPARC_STACK_BOUNDARY_HACK
4275 /* ??? The SPARC port may claim a STACK_BOUNDARY higher than
4276 the real alignment of %sp. However, when it does this, the
4277 alignment of %sp+STACK_POINTER_OFFSET is STACK_BOUNDARY. */
4278 if (SPARC_STACK_BOUNDARY_HACK)
4279 sp_offset = 0;
4280 #endif
4282 if (boundary > PARM_BOUNDARY)
4284 save_var = offset_ptr->var;
4285 save_constant = offset_ptr->constant;
4288 alignment_pad->var = NULL_TREE;
4289 alignment_pad->constant = 0;
4291 if (boundary > BITS_PER_UNIT)
4293 if (offset_ptr->var)
4295 tree sp_offset_tree = ssize_int (sp_offset);
4296 tree offset = size_binop (PLUS_EXPR,
4297 ARGS_SIZE_TREE (*offset_ptr),
4298 sp_offset_tree);
4299 tree rounded;
4300 if (ARGS_GROW_DOWNWARD)
4301 rounded = round_down (offset, boundary / BITS_PER_UNIT);
4302 else
4303 rounded = round_up (offset, boundary / BITS_PER_UNIT);
4305 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
4306 /* ARGS_SIZE_TREE includes constant term. */
4307 offset_ptr->constant = 0;
4308 if (boundary > PARM_BOUNDARY)
4309 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
4310 save_var);
4312 else
4314 offset_ptr->constant = -sp_offset +
4315 (ARGS_GROW_DOWNWARD
4316 ? FLOOR_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes)
4317 : CEIL_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes));
4319 if (boundary > PARM_BOUNDARY)
4320 alignment_pad->constant = offset_ptr->constant - save_constant;
4325 static void
4326 pad_below (struct args_size *offset_ptr, machine_mode passed_mode, tree sizetree)
4328 unsigned int align = PARM_BOUNDARY / BITS_PER_UNIT;
4329 if (passed_mode != BLKmode)
4330 offset_ptr->constant += -GET_MODE_SIZE (passed_mode) & (align - 1);
4331 else
4333 if (TREE_CODE (sizetree) != INTEGER_CST
4334 || (TREE_INT_CST_LOW (sizetree) & (align - 1)) != 0)
4336 /* Round the size up to multiple of PARM_BOUNDARY bits. */
4337 tree s2 = round_up (sizetree, align);
4338 /* Add it in. */
4339 ADD_PARM_SIZE (*offset_ptr, s2);
4340 SUB_PARM_SIZE (*offset_ptr, sizetree);
4346 /* True if register REGNO was alive at a place where `setjmp' was
4347 called and was set more than once or is an argument. Such regs may
4348 be clobbered by `longjmp'. */
4350 static bool
4351 regno_clobbered_at_setjmp (bitmap setjmp_crosses, int regno)
4353 /* There appear to be cases where some local vars never reach the
4354 backend but have bogus regnos. */
4355 if (regno >= max_reg_num ())
4356 return false;
4358 return ((REG_N_SETS (regno) > 1
4359 || REGNO_REG_SET_P (df_get_live_out (ENTRY_BLOCK_PTR_FOR_FN (cfun)),
4360 regno))
4361 && REGNO_REG_SET_P (setjmp_crosses, regno));
4364 /* Walk the tree of blocks describing the binding levels within a
4365 function and warn about variables the might be killed by setjmp or
4366 vfork. This is done after calling flow_analysis before register
4367 allocation since that will clobber the pseudo-regs to hard
4368 regs. */
4370 static void
4371 setjmp_vars_warning (bitmap setjmp_crosses, tree block)
4373 tree decl, sub;
4375 for (decl = BLOCK_VARS (block); decl; decl = DECL_CHAIN (decl))
4377 if (VAR_P (decl)
4378 && DECL_RTL_SET_P (decl)
4379 && REG_P (DECL_RTL (decl))
4380 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
4381 warning (OPT_Wclobbered, "variable %q+D might be clobbered by"
4382 " %<longjmp%> or %<vfork%>", decl);
4385 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = BLOCK_CHAIN (sub))
4386 setjmp_vars_warning (setjmp_crosses, sub);
4389 /* Do the appropriate part of setjmp_vars_warning
4390 but for arguments instead of local variables. */
4392 static void
4393 setjmp_args_warning (bitmap setjmp_crosses)
4395 tree decl;
4396 for (decl = DECL_ARGUMENTS (current_function_decl);
4397 decl; decl = DECL_CHAIN (decl))
4398 if (DECL_RTL (decl) != 0
4399 && REG_P (DECL_RTL (decl))
4400 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
4401 warning (OPT_Wclobbered,
4402 "argument %q+D might be clobbered by %<longjmp%> or %<vfork%>",
4403 decl);
4406 /* Generate warning messages for variables live across setjmp. */
4408 void
4409 generate_setjmp_warnings (void)
4411 bitmap setjmp_crosses = regstat_get_setjmp_crosses ();
4413 if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS
4414 || bitmap_empty_p (setjmp_crosses))
4415 return;
4417 setjmp_vars_warning (setjmp_crosses, DECL_INITIAL (current_function_decl));
4418 setjmp_args_warning (setjmp_crosses);
4422 /* Reverse the order of elements in the fragment chain T of blocks,
4423 and return the new head of the chain (old last element).
4424 In addition to that clear BLOCK_SAME_RANGE flags when needed
4425 and adjust BLOCK_SUPERCONTEXT from the super fragment to
4426 its super fragment origin. */
4428 static tree
4429 block_fragments_nreverse (tree t)
4431 tree prev = 0, block, next, prev_super = 0;
4432 tree super = BLOCK_SUPERCONTEXT (t);
4433 if (BLOCK_FRAGMENT_ORIGIN (super))
4434 super = BLOCK_FRAGMENT_ORIGIN (super);
4435 for (block = t; block; block = next)
4437 next = BLOCK_FRAGMENT_CHAIN (block);
4438 BLOCK_FRAGMENT_CHAIN (block) = prev;
4439 if ((prev && !BLOCK_SAME_RANGE (prev))
4440 || (BLOCK_FRAGMENT_CHAIN (BLOCK_SUPERCONTEXT (block))
4441 != prev_super))
4442 BLOCK_SAME_RANGE (block) = 0;
4443 prev_super = BLOCK_SUPERCONTEXT (block);
4444 BLOCK_SUPERCONTEXT (block) = super;
4445 prev = block;
4447 t = BLOCK_FRAGMENT_ORIGIN (t);
4448 if (BLOCK_FRAGMENT_CHAIN (BLOCK_SUPERCONTEXT (t))
4449 != prev_super)
4450 BLOCK_SAME_RANGE (t) = 0;
4451 BLOCK_SUPERCONTEXT (t) = super;
4452 return prev;
4455 /* Reverse the order of elements in the chain T of blocks,
4456 and return the new head of the chain (old last element).
4457 Also do the same on subblocks and reverse the order of elements
4458 in BLOCK_FRAGMENT_CHAIN as well. */
4460 static tree
4461 blocks_nreverse_all (tree t)
4463 tree prev = 0, block, next;
4464 for (block = t; block; block = next)
4466 next = BLOCK_CHAIN (block);
4467 BLOCK_CHAIN (block) = prev;
4468 if (BLOCK_FRAGMENT_CHAIN (block)
4469 && BLOCK_FRAGMENT_ORIGIN (block) == NULL_TREE)
4471 BLOCK_FRAGMENT_CHAIN (block)
4472 = block_fragments_nreverse (BLOCK_FRAGMENT_CHAIN (block));
4473 if (!BLOCK_SAME_RANGE (BLOCK_FRAGMENT_CHAIN (block)))
4474 BLOCK_SAME_RANGE (block) = 0;
4476 BLOCK_SUBBLOCKS (block) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block));
4477 prev = block;
4479 return prev;
4483 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
4484 and create duplicate blocks. */
4485 /* ??? Need an option to either create block fragments or to create
4486 abstract origin duplicates of a source block. It really depends
4487 on what optimization has been performed. */
4489 void
4490 reorder_blocks (void)
4492 tree block = DECL_INITIAL (current_function_decl);
4494 if (block == NULL_TREE)
4495 return;
4497 auto_vec<tree, 10> block_stack;
4499 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
4500 clear_block_marks (block);
4502 /* Prune the old trees away, so that they don't get in the way. */
4503 BLOCK_SUBBLOCKS (block) = NULL_TREE;
4504 BLOCK_CHAIN (block) = NULL_TREE;
4506 /* Recreate the block tree from the note nesting. */
4507 reorder_blocks_1 (get_insns (), block, &block_stack);
4508 BLOCK_SUBBLOCKS (block) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block));
4511 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
4513 void
4514 clear_block_marks (tree block)
4516 while (block)
4518 TREE_ASM_WRITTEN (block) = 0;
4519 clear_block_marks (BLOCK_SUBBLOCKS (block));
4520 block = BLOCK_CHAIN (block);
4524 static void
4525 reorder_blocks_1 (rtx_insn *insns, tree current_block,
4526 vec<tree> *p_block_stack)
4528 rtx_insn *insn;
4529 tree prev_beg = NULL_TREE, prev_end = NULL_TREE;
4531 for (insn = insns; insn; insn = NEXT_INSN (insn))
4533 if (NOTE_P (insn))
4535 if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_BEG)
4537 tree block = NOTE_BLOCK (insn);
4538 tree origin;
4540 gcc_assert (BLOCK_FRAGMENT_ORIGIN (block) == NULL_TREE);
4541 origin = block;
4543 if (prev_end)
4544 BLOCK_SAME_RANGE (prev_end) = 0;
4545 prev_end = NULL_TREE;
4547 /* If we have seen this block before, that means it now
4548 spans multiple address regions. Create a new fragment. */
4549 if (TREE_ASM_WRITTEN (block))
4551 tree new_block = copy_node (block);
4553 BLOCK_SAME_RANGE (new_block) = 0;
4554 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
4555 BLOCK_FRAGMENT_CHAIN (new_block)
4556 = BLOCK_FRAGMENT_CHAIN (origin);
4557 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
4559 NOTE_BLOCK (insn) = new_block;
4560 block = new_block;
4563 if (prev_beg == current_block && prev_beg)
4564 BLOCK_SAME_RANGE (block) = 1;
4566 prev_beg = origin;
4568 BLOCK_SUBBLOCKS (block) = 0;
4569 TREE_ASM_WRITTEN (block) = 1;
4570 /* When there's only one block for the entire function,
4571 current_block == block and we mustn't do this, it
4572 will cause infinite recursion. */
4573 if (block != current_block)
4575 tree super;
4576 if (block != origin)
4577 gcc_assert (BLOCK_SUPERCONTEXT (origin) == current_block
4578 || BLOCK_FRAGMENT_ORIGIN (BLOCK_SUPERCONTEXT
4579 (origin))
4580 == current_block);
4581 if (p_block_stack->is_empty ())
4582 super = current_block;
4583 else
4585 super = p_block_stack->last ();
4586 gcc_assert (super == current_block
4587 || BLOCK_FRAGMENT_ORIGIN (super)
4588 == current_block);
4590 BLOCK_SUPERCONTEXT (block) = super;
4591 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
4592 BLOCK_SUBBLOCKS (current_block) = block;
4593 current_block = origin;
4595 p_block_stack->safe_push (block);
4597 else if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_END)
4599 NOTE_BLOCK (insn) = p_block_stack->pop ();
4600 current_block = BLOCK_SUPERCONTEXT (current_block);
4601 if (BLOCK_FRAGMENT_ORIGIN (current_block))
4602 current_block = BLOCK_FRAGMENT_ORIGIN (current_block);
4603 prev_beg = NULL_TREE;
4604 prev_end = BLOCK_SAME_RANGE (NOTE_BLOCK (insn))
4605 ? NOTE_BLOCK (insn) : NULL_TREE;
4608 else
4610 prev_beg = NULL_TREE;
4611 if (prev_end)
4612 BLOCK_SAME_RANGE (prev_end) = 0;
4613 prev_end = NULL_TREE;
4618 /* Reverse the order of elements in the chain T of blocks,
4619 and return the new head of the chain (old last element). */
4621 tree
4622 blocks_nreverse (tree t)
4624 tree prev = 0, block, next;
4625 for (block = t; block; block = next)
4627 next = BLOCK_CHAIN (block);
4628 BLOCK_CHAIN (block) = prev;
4629 prev = block;
4631 return prev;
4634 /* Concatenate two chains of blocks (chained through BLOCK_CHAIN)
4635 by modifying the last node in chain 1 to point to chain 2. */
4637 tree
4638 block_chainon (tree op1, tree op2)
4640 tree t1;
4642 if (!op1)
4643 return op2;
4644 if (!op2)
4645 return op1;
4647 for (t1 = op1; BLOCK_CHAIN (t1); t1 = BLOCK_CHAIN (t1))
4648 continue;
4649 BLOCK_CHAIN (t1) = op2;
4651 #ifdef ENABLE_TREE_CHECKING
4653 tree t2;
4654 for (t2 = op2; t2; t2 = BLOCK_CHAIN (t2))
4655 gcc_assert (t2 != t1);
4657 #endif
4659 return op1;
4662 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
4663 non-NULL, list them all into VECTOR, in a depth-first preorder
4664 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
4665 blocks. */
4667 static int
4668 all_blocks (tree block, tree *vector)
4670 int n_blocks = 0;
4672 while (block)
4674 TREE_ASM_WRITTEN (block) = 0;
4676 /* Record this block. */
4677 if (vector)
4678 vector[n_blocks] = block;
4680 ++n_blocks;
4682 /* Record the subblocks, and their subblocks... */
4683 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
4684 vector ? vector + n_blocks : 0);
4685 block = BLOCK_CHAIN (block);
4688 return n_blocks;
4691 /* Return a vector containing all the blocks rooted at BLOCK. The
4692 number of elements in the vector is stored in N_BLOCKS_P. The
4693 vector is dynamically allocated; it is the caller's responsibility
4694 to call `free' on the pointer returned. */
4696 static tree *
4697 get_block_vector (tree block, int *n_blocks_p)
4699 tree *block_vector;
4701 *n_blocks_p = all_blocks (block, NULL);
4702 block_vector = XNEWVEC (tree, *n_blocks_p);
4703 all_blocks (block, block_vector);
4705 return block_vector;
4708 static GTY(()) int next_block_index = 2;
4710 /* Set BLOCK_NUMBER for all the blocks in FN. */
4712 void
4713 number_blocks (tree fn)
4715 int i;
4716 int n_blocks;
4717 tree *block_vector;
4719 /* For XCOFF debugging output, we start numbering the blocks
4720 from 1 within each function, rather than keeping a running
4721 count. */
4722 #if defined (XCOFF_DEBUGGING_INFO)
4723 if (write_symbols == XCOFF_DEBUG)
4724 next_block_index = 1;
4725 #endif
4727 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
4729 /* The top-level BLOCK isn't numbered at all. */
4730 for (i = 1; i < n_blocks; ++i)
4731 /* We number the blocks from two. */
4732 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
4734 free (block_vector);
4736 return;
4739 /* If VAR is present in a subblock of BLOCK, return the subblock. */
4741 DEBUG_FUNCTION tree
4742 debug_find_var_in_block_tree (tree var, tree block)
4744 tree t;
4746 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
4747 if (t == var)
4748 return block;
4750 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
4752 tree ret = debug_find_var_in_block_tree (var, t);
4753 if (ret)
4754 return ret;
4757 return NULL_TREE;
4760 /* Keep track of whether we're in a dummy function context. If we are,
4761 we don't want to invoke the set_current_function hook, because we'll
4762 get into trouble if the hook calls target_reinit () recursively or
4763 when the initial initialization is not yet complete. */
4765 static bool in_dummy_function;
4767 /* Invoke the target hook when setting cfun. Update the optimization options
4768 if the function uses different options than the default. */
4770 static void
4771 invoke_set_current_function_hook (tree fndecl)
4773 if (!in_dummy_function)
4775 tree opts = ((fndecl)
4776 ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (fndecl)
4777 : optimization_default_node);
4779 if (!opts)
4780 opts = optimization_default_node;
4782 /* Change optimization options if needed. */
4783 if (optimization_current_node != opts)
4785 optimization_current_node = opts;
4786 cl_optimization_restore (&global_options, TREE_OPTIMIZATION (opts));
4789 targetm.set_current_function (fndecl);
4790 this_fn_optabs = this_target_optabs;
4792 if (opts != optimization_default_node)
4794 init_tree_optimization_optabs (opts);
4795 if (TREE_OPTIMIZATION_OPTABS (opts))
4796 this_fn_optabs = (struct target_optabs *)
4797 TREE_OPTIMIZATION_OPTABS (opts);
4802 /* cfun should never be set directly; use this function. */
4804 void
4805 set_cfun (struct function *new_cfun, bool force)
4807 if (cfun != new_cfun || force)
4809 cfun = new_cfun;
4810 invoke_set_current_function_hook (new_cfun ? new_cfun->decl : NULL_TREE);
4811 redirect_edge_var_map_empty ();
4815 /* Initialized with NOGC, making this poisonous to the garbage collector. */
4817 static vec<function *> cfun_stack;
4819 /* Push the current cfun onto the stack, and set cfun to new_cfun. Also set
4820 current_function_decl accordingly. */
4822 void
4823 push_cfun (struct function *new_cfun)
4825 gcc_assert ((!cfun && !current_function_decl)
4826 || (cfun && current_function_decl == cfun->decl));
4827 cfun_stack.safe_push (cfun);
4828 current_function_decl = new_cfun ? new_cfun->decl : NULL_TREE;
4829 set_cfun (new_cfun);
4832 /* Pop cfun from the stack. Also set current_function_decl accordingly. */
4834 void
4835 pop_cfun (void)
4837 struct function *new_cfun = cfun_stack.pop ();
4838 /* When in_dummy_function, we do have a cfun but current_function_decl is
4839 NULL. We also allow pushing NULL cfun and subsequently changing
4840 current_function_decl to something else and have both restored by
4841 pop_cfun. */
4842 gcc_checking_assert (in_dummy_function
4843 || !cfun
4844 || current_function_decl == cfun->decl);
4845 set_cfun (new_cfun);
4846 current_function_decl = new_cfun ? new_cfun->decl : NULL_TREE;
4849 /* Return value of funcdef and increase it. */
4851 get_next_funcdef_no (void)
4853 return funcdef_no++;
4856 /* Return value of funcdef. */
4858 get_last_funcdef_no (void)
4860 return funcdef_no;
4863 /* Allocate a function structure for FNDECL and set its contents
4864 to the defaults. Set cfun to the newly-allocated object.
4865 Some of the helper functions invoked during initialization assume
4866 that cfun has already been set. Therefore, assign the new object
4867 directly into cfun and invoke the back end hook explicitly at the
4868 very end, rather than initializing a temporary and calling set_cfun
4869 on it.
4871 ABSTRACT_P is true if this is a function that will never be seen by
4872 the middle-end. Such functions are front-end concepts (like C++
4873 function templates) that do not correspond directly to functions
4874 placed in object files. */
4876 void
4877 allocate_struct_function (tree fndecl, bool abstract_p)
4879 tree fntype = fndecl ? TREE_TYPE (fndecl) : NULL_TREE;
4881 cfun = ggc_cleared_alloc<function> ();
4883 init_eh_for_function ();
4885 if (init_machine_status)
4886 cfun->machine = (*init_machine_status) ();
4888 #ifdef OVERRIDE_ABI_FORMAT
4889 OVERRIDE_ABI_FORMAT (fndecl);
4890 #endif
4892 if (fndecl != NULL_TREE)
4894 DECL_STRUCT_FUNCTION (fndecl) = cfun;
4895 cfun->decl = fndecl;
4896 current_function_funcdef_no = get_next_funcdef_no ();
4899 invoke_set_current_function_hook (fndecl);
4901 if (fndecl != NULL_TREE)
4903 tree result = DECL_RESULT (fndecl);
4905 if (!abstract_p)
4907 /* Now that we have activated any function-specific attributes
4908 that might affect layout, particularly vector modes, relayout
4909 each of the parameters and the result. */
4910 relayout_decl (result);
4911 for (tree parm = DECL_ARGUMENTS (fndecl); parm;
4912 parm = DECL_CHAIN (parm))
4913 relayout_decl (parm);
4915 /* Similarly relayout the function decl. */
4916 targetm.target_option.relayout_function (fndecl);
4919 if (!abstract_p && aggregate_value_p (result, fndecl))
4921 #ifdef PCC_STATIC_STRUCT_RETURN
4922 cfun->returns_pcc_struct = 1;
4923 #endif
4924 cfun->returns_struct = 1;
4927 cfun->stdarg = stdarg_p (fntype);
4929 /* Assume all registers in stdarg functions need to be saved. */
4930 cfun->va_list_gpr_size = VA_LIST_MAX_GPR_SIZE;
4931 cfun->va_list_fpr_size = VA_LIST_MAX_FPR_SIZE;
4933 /* ??? This could be set on a per-function basis by the front-end
4934 but is this worth the hassle? */
4935 cfun->can_throw_non_call_exceptions = flag_non_call_exceptions;
4936 cfun->can_delete_dead_exceptions = flag_delete_dead_exceptions;
4938 if (!profile_flag && !flag_instrument_function_entry_exit)
4939 DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl) = 1;
4943 /* This is like allocate_struct_function, but pushes a new cfun for FNDECL
4944 instead of just setting it. */
4946 void
4947 push_struct_function (tree fndecl)
4949 /* When in_dummy_function we might be in the middle of a pop_cfun and
4950 current_function_decl and cfun may not match. */
4951 gcc_assert (in_dummy_function
4952 || (!cfun && !current_function_decl)
4953 || (cfun && current_function_decl == cfun->decl));
4954 cfun_stack.safe_push (cfun);
4955 current_function_decl = fndecl;
4956 allocate_struct_function (fndecl, false);
4959 /* Reset crtl and other non-struct-function variables to defaults as
4960 appropriate for emitting rtl at the start of a function. */
4962 static void
4963 prepare_function_start (void)
4965 gcc_assert (!get_last_insn ());
4966 init_temp_slots ();
4967 init_emit ();
4968 init_varasm_status ();
4969 init_expr ();
4970 default_rtl_profile ();
4972 if (flag_stack_usage_info)
4974 cfun->su = ggc_cleared_alloc<stack_usage> ();
4975 cfun->su->static_stack_size = -1;
4978 cse_not_expected = ! optimize;
4980 /* Caller save not needed yet. */
4981 caller_save_needed = 0;
4983 /* We haven't done register allocation yet. */
4984 reg_renumber = 0;
4986 /* Indicate that we have not instantiated virtual registers yet. */
4987 virtuals_instantiated = 0;
4989 /* Indicate that we want CONCATs now. */
4990 generating_concat_p = 1;
4992 /* Indicate we have no need of a frame pointer yet. */
4993 frame_pointer_needed = 0;
4996 void
4997 push_dummy_function (bool with_decl)
4999 tree fn_decl, fn_type, fn_result_decl;
5001 gcc_assert (!in_dummy_function);
5002 in_dummy_function = true;
5004 if (with_decl)
5006 fn_type = build_function_type_list (void_type_node, NULL_TREE);
5007 fn_decl = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL, NULL_TREE,
5008 fn_type);
5009 fn_result_decl = build_decl (UNKNOWN_LOCATION, RESULT_DECL,
5010 NULL_TREE, void_type_node);
5011 DECL_RESULT (fn_decl) = fn_result_decl;
5013 else
5014 fn_decl = NULL_TREE;
5016 push_struct_function (fn_decl);
5019 /* Initialize the rtl expansion mechanism so that we can do simple things
5020 like generate sequences. This is used to provide a context during global
5021 initialization of some passes. You must call expand_dummy_function_end
5022 to exit this context. */
5024 void
5025 init_dummy_function_start (void)
5027 push_dummy_function (false);
5028 prepare_function_start ();
5031 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
5032 and initialize static variables for generating RTL for the statements
5033 of the function. */
5035 void
5036 init_function_start (tree subr)
5038 /* Initialize backend, if needed. */
5039 initialize_rtl ();
5041 prepare_function_start ();
5042 decide_function_section (subr);
5044 /* Warn if this value is an aggregate type,
5045 regardless of which calling convention we are using for it. */
5046 if (AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
5047 warning (OPT_Waggregate_return, "function returns an aggregate");
5050 /* Expand code to verify the stack_protect_guard. This is invoked at
5051 the end of a function to be protected. */
5053 void
5054 stack_protect_epilogue (void)
5056 tree guard_decl = targetm.stack_protect_guard ();
5057 rtx_code_label *label = gen_label_rtx ();
5058 rtx x, y;
5059 rtx_insn *seq;
5061 x = expand_normal (crtl->stack_protect_guard);
5062 if (guard_decl)
5063 y = expand_normal (guard_decl);
5064 else
5065 y = const0_rtx;
5067 /* Allow the target to compare Y with X without leaking either into
5068 a register. */
5069 if (targetm.have_stack_protect_test ()
5070 && ((seq = targetm.gen_stack_protect_test (x, y, label)) != NULL_RTX))
5071 emit_insn (seq);
5072 else
5073 emit_cmp_and_jump_insns (x, y, EQ, NULL_RTX, ptr_mode, 1, label);
5075 /* The noreturn predictor has been moved to the tree level. The rtl-level
5076 predictors estimate this branch about 20%, which isn't enough to get
5077 things moved out of line. Since this is the only extant case of adding
5078 a noreturn function at the rtl level, it doesn't seem worth doing ought
5079 except adding the prediction by hand. */
5080 rtx_insn *tmp = get_last_insn ();
5081 if (JUMP_P (tmp))
5082 predict_insn_def (tmp, PRED_NORETURN, TAKEN);
5084 expand_call (targetm.stack_protect_fail (), NULL_RTX, /*ignore=*/true);
5085 free_temp_slots ();
5086 emit_label (label);
5089 /* Start the RTL for a new function, and set variables used for
5090 emitting RTL.
5091 SUBR is the FUNCTION_DECL node.
5092 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
5093 the function's parameters, which must be run at any return statement. */
5095 void
5096 expand_function_start (tree subr)
5098 /* Make sure volatile mem refs aren't considered
5099 valid operands of arithmetic insns. */
5100 init_recog_no_volatile ();
5102 crtl->profile
5103 = (profile_flag
5104 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
5106 crtl->limit_stack
5107 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
5109 /* Make the label for return statements to jump to. Do not special
5110 case machines with special return instructions -- they will be
5111 handled later during jump, ifcvt, or epilogue creation. */
5112 return_label = gen_label_rtx ();
5114 /* Initialize rtx used to return the value. */
5115 /* Do this before assign_parms so that we copy the struct value address
5116 before any library calls that assign parms might generate. */
5118 /* Decide whether to return the value in memory or in a register. */
5119 tree res = DECL_RESULT (subr);
5120 if (aggregate_value_p (res, subr))
5122 /* Returning something that won't go in a register. */
5123 rtx value_address = 0;
5125 #ifdef PCC_STATIC_STRUCT_RETURN
5126 if (cfun->returns_pcc_struct)
5128 int size = int_size_in_bytes (TREE_TYPE (res));
5129 value_address = assemble_static_space (size);
5131 else
5132 #endif
5134 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 2);
5135 /* Expect to be passed the address of a place to store the value.
5136 If it is passed as an argument, assign_parms will take care of
5137 it. */
5138 if (sv)
5140 value_address = gen_reg_rtx (Pmode);
5141 emit_move_insn (value_address, sv);
5144 if (value_address)
5146 rtx x = value_address;
5147 if (!DECL_BY_REFERENCE (res))
5149 x = gen_rtx_MEM (DECL_MODE (res), x);
5150 set_mem_attributes (x, res, 1);
5152 set_parm_rtl (res, x);
5155 else if (DECL_MODE (res) == VOIDmode)
5156 /* If return mode is void, this decl rtl should not be used. */
5157 set_parm_rtl (res, NULL_RTX);
5158 else
5160 /* Compute the return values into a pseudo reg, which we will copy
5161 into the true return register after the cleanups are done. */
5162 tree return_type = TREE_TYPE (res);
5164 /* If we may coalesce this result, make sure it has the expected mode
5165 in case it was promoted. But we need not bother about BLKmode. */
5166 machine_mode promoted_mode
5167 = flag_tree_coalesce_vars && is_gimple_reg (res)
5168 ? promote_ssa_mode (ssa_default_def (cfun, res), NULL)
5169 : BLKmode;
5171 if (promoted_mode != BLKmode)
5172 set_parm_rtl (res, gen_reg_rtx (promoted_mode));
5173 else if (TYPE_MODE (return_type) != BLKmode
5174 && targetm.calls.return_in_msb (return_type))
5175 /* expand_function_end will insert the appropriate padding in
5176 this case. Use the return value's natural (unpadded) mode
5177 within the function proper. */
5178 set_parm_rtl (res, gen_reg_rtx (TYPE_MODE (return_type)));
5179 else
5181 /* In order to figure out what mode to use for the pseudo, we
5182 figure out what the mode of the eventual return register will
5183 actually be, and use that. */
5184 rtx hard_reg = hard_function_value (return_type, subr, 0, 1);
5186 /* Structures that are returned in registers are not
5187 aggregate_value_p, so we may see a PARALLEL or a REG. */
5188 if (REG_P (hard_reg))
5189 set_parm_rtl (res, gen_reg_rtx (GET_MODE (hard_reg)));
5190 else
5192 gcc_assert (GET_CODE (hard_reg) == PARALLEL);
5193 set_parm_rtl (res, gen_group_rtx (hard_reg));
5197 /* Set DECL_REGISTER flag so that expand_function_end will copy the
5198 result to the real return register(s). */
5199 DECL_REGISTER (res) = 1;
5201 if (chkp_function_instrumented_p (current_function_decl))
5203 tree return_type = TREE_TYPE (res);
5204 rtx bounds = targetm.calls.chkp_function_value_bounds (return_type,
5205 subr, 1);
5206 SET_DECL_BOUNDS_RTL (res, bounds);
5210 /* Initialize rtx for parameters and local variables.
5211 In some cases this requires emitting insns. */
5212 assign_parms (subr);
5214 /* If function gets a static chain arg, store it. */
5215 if (cfun->static_chain_decl)
5217 tree parm = cfun->static_chain_decl;
5218 rtx local, chain;
5219 rtx_insn *insn;
5220 int unsignedp;
5222 local = gen_reg_rtx (promote_decl_mode (parm, &unsignedp));
5223 chain = targetm.calls.static_chain (current_function_decl, true);
5225 set_decl_incoming_rtl (parm, chain, false);
5226 set_parm_rtl (parm, local);
5227 mark_reg_pointer (local, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
5229 if (GET_MODE (local) != GET_MODE (chain))
5231 convert_move (local, chain, unsignedp);
5232 insn = get_last_insn ();
5234 else
5235 insn = emit_move_insn (local, chain);
5237 /* Mark the register as eliminable, similar to parameters. */
5238 if (MEM_P (chain)
5239 && reg_mentioned_p (arg_pointer_rtx, XEXP (chain, 0)))
5240 set_dst_reg_note (insn, REG_EQUIV, chain, local);
5242 /* If we aren't optimizing, save the static chain onto the stack. */
5243 if (!optimize)
5245 tree saved_static_chain_decl
5246 = build_decl (DECL_SOURCE_LOCATION (parm), VAR_DECL,
5247 DECL_NAME (parm), TREE_TYPE (parm));
5248 rtx saved_static_chain_rtx
5249 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
5250 SET_DECL_RTL (saved_static_chain_decl, saved_static_chain_rtx);
5251 emit_move_insn (saved_static_chain_rtx, chain);
5252 SET_DECL_VALUE_EXPR (parm, saved_static_chain_decl);
5253 DECL_HAS_VALUE_EXPR_P (parm) = 1;
5257 /* The following was moved from init_function_start.
5258 The move was supposed to make sdb output more accurate. */
5259 /* Indicate the beginning of the function body,
5260 as opposed to parm setup. */
5261 emit_note (NOTE_INSN_FUNCTION_BEG);
5263 gcc_assert (NOTE_P (get_last_insn ()));
5265 parm_birth_insn = get_last_insn ();
5267 /* If the function receives a non-local goto, then store the
5268 bits we need to restore the frame pointer. */
5269 if (cfun->nonlocal_goto_save_area)
5271 tree t_save;
5272 rtx r_save;
5274 tree var = TREE_OPERAND (cfun->nonlocal_goto_save_area, 0);
5275 gcc_assert (DECL_RTL_SET_P (var));
5277 t_save = build4 (ARRAY_REF,
5278 TREE_TYPE (TREE_TYPE (cfun->nonlocal_goto_save_area)),
5279 cfun->nonlocal_goto_save_area,
5280 integer_zero_node, NULL_TREE, NULL_TREE);
5281 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
5282 gcc_assert (GET_MODE (r_save) == Pmode);
5284 emit_move_insn (r_save, targetm.builtin_setjmp_frame_value ());
5285 update_nonlocal_goto_save_area ();
5288 if (crtl->profile)
5290 #ifdef PROFILE_HOOK
5291 PROFILE_HOOK (current_function_funcdef_no);
5292 #endif
5295 /* If we are doing generic stack checking, the probe should go here. */
5296 if (flag_stack_check == GENERIC_STACK_CHECK)
5297 stack_check_probe_note = emit_note (NOTE_INSN_DELETED);
5300 void
5301 pop_dummy_function (void)
5303 pop_cfun ();
5304 in_dummy_function = false;
5307 /* Undo the effects of init_dummy_function_start. */
5308 void
5309 expand_dummy_function_end (void)
5311 gcc_assert (in_dummy_function);
5313 /* End any sequences that failed to be closed due to syntax errors. */
5314 while (in_sequence_p ())
5315 end_sequence ();
5317 /* Outside function body, can't compute type's actual size
5318 until next function's body starts. */
5320 free_after_parsing (cfun);
5321 free_after_compilation (cfun);
5322 pop_dummy_function ();
5325 /* Helper for diddle_return_value. */
5327 void
5328 diddle_return_value_1 (void (*doit) (rtx, void *), void *arg, rtx outgoing)
5330 if (! outgoing)
5331 return;
5333 if (REG_P (outgoing))
5334 (*doit) (outgoing, arg);
5335 else if (GET_CODE (outgoing) == PARALLEL)
5337 int i;
5339 for (i = 0; i < XVECLEN (outgoing, 0); i++)
5341 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
5343 if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
5344 (*doit) (x, arg);
5349 /* Call DOIT for each hard register used as a return value from
5350 the current function. */
5352 void
5353 diddle_return_value (void (*doit) (rtx, void *), void *arg)
5355 diddle_return_value_1 (doit, arg, crtl->return_bnd);
5356 diddle_return_value_1 (doit, arg, crtl->return_rtx);
5359 static void
5360 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
5362 emit_clobber (reg);
5365 void
5366 clobber_return_register (void)
5368 diddle_return_value (do_clobber_return_reg, NULL);
5370 /* In case we do use pseudo to return value, clobber it too. */
5371 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
5373 tree decl_result = DECL_RESULT (current_function_decl);
5374 rtx decl_rtl = DECL_RTL (decl_result);
5375 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
5377 do_clobber_return_reg (decl_rtl, NULL);
5382 static void
5383 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
5385 emit_use (reg);
5388 static void
5389 use_return_register (void)
5391 diddle_return_value (do_use_return_reg, NULL);
5394 /* Set the location of the insn chain starting at INSN to LOC. */
5396 static void
5397 set_insn_locations (rtx_insn *insn, int loc)
5399 while (insn != NULL)
5401 if (INSN_P (insn))
5402 INSN_LOCATION (insn) = loc;
5403 insn = NEXT_INSN (insn);
5407 /* Generate RTL for the end of the current function. */
5409 void
5410 expand_function_end (void)
5412 /* If arg_pointer_save_area was referenced only from a nested
5413 function, we will not have initialized it yet. Do that now. */
5414 if (arg_pointer_save_area && ! crtl->arg_pointer_save_area_init)
5415 get_arg_pointer_save_area ();
5417 /* If we are doing generic stack checking and this function makes calls,
5418 do a stack probe at the start of the function to ensure we have enough
5419 space for another stack frame. */
5420 if (flag_stack_check == GENERIC_STACK_CHECK)
5422 rtx_insn *insn, *seq;
5424 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
5425 if (CALL_P (insn))
5427 rtx max_frame_size = GEN_INT (STACK_CHECK_MAX_FRAME_SIZE);
5428 start_sequence ();
5429 if (STACK_CHECK_MOVING_SP)
5430 anti_adjust_stack_and_probe (max_frame_size, true);
5431 else
5432 probe_stack_range (STACK_OLD_CHECK_PROTECT, max_frame_size);
5433 seq = get_insns ();
5434 end_sequence ();
5435 set_insn_locations (seq, prologue_location);
5436 emit_insn_before (seq, stack_check_probe_note);
5437 break;
5441 /* End any sequences that failed to be closed due to syntax errors. */
5442 while (in_sequence_p ())
5443 end_sequence ();
5445 clear_pending_stack_adjust ();
5446 do_pending_stack_adjust ();
5448 /* Output a linenumber for the end of the function.
5449 SDB depended on this. */
5450 set_curr_insn_location (input_location);
5452 /* Before the return label (if any), clobber the return
5453 registers so that they are not propagated live to the rest of
5454 the function. This can only happen with functions that drop
5455 through; if there had been a return statement, there would
5456 have either been a return rtx, or a jump to the return label.
5458 We delay actual code generation after the current_function_value_rtx
5459 is computed. */
5460 rtx_insn *clobber_after = get_last_insn ();
5462 /* Output the label for the actual return from the function. */
5463 emit_label (return_label);
5465 if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ)
5467 /* Let except.c know where it should emit the call to unregister
5468 the function context for sjlj exceptions. */
5469 if (flag_exceptions)
5470 sjlj_emit_function_exit_after (get_last_insn ());
5472 else
5474 /* We want to ensure that instructions that may trap are not
5475 moved into the epilogue by scheduling, because we don't
5476 always emit unwind information for the epilogue. */
5477 if (cfun->can_throw_non_call_exceptions)
5478 emit_insn (gen_blockage ());
5481 /* If this is an implementation of throw, do what's necessary to
5482 communicate between __builtin_eh_return and the epilogue. */
5483 expand_eh_return ();
5485 /* If scalar return value was computed in a pseudo-reg, or was a named
5486 return value that got dumped to the stack, copy that to the hard
5487 return register. */
5488 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
5490 tree decl_result = DECL_RESULT (current_function_decl);
5491 rtx decl_rtl = DECL_RTL (decl_result);
5493 if (REG_P (decl_rtl)
5494 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
5495 : DECL_REGISTER (decl_result))
5497 rtx real_decl_rtl = crtl->return_rtx;
5498 complex_mode cmode;
5500 /* This should be set in assign_parms. */
5501 gcc_assert (REG_FUNCTION_VALUE_P (real_decl_rtl));
5503 /* If this is a BLKmode structure being returned in registers,
5504 then use the mode computed in expand_return. Note that if
5505 decl_rtl is memory, then its mode may have been changed,
5506 but that crtl->return_rtx has not. */
5507 if (GET_MODE (real_decl_rtl) == BLKmode)
5508 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
5510 /* If a non-BLKmode return value should be padded at the least
5511 significant end of the register, shift it left by the appropriate
5512 amount. BLKmode results are handled using the group load/store
5513 machinery. */
5514 if (TYPE_MODE (TREE_TYPE (decl_result)) != BLKmode
5515 && REG_P (real_decl_rtl)
5516 && targetm.calls.return_in_msb (TREE_TYPE (decl_result)))
5518 emit_move_insn (gen_rtx_REG (GET_MODE (decl_rtl),
5519 REGNO (real_decl_rtl)),
5520 decl_rtl);
5521 shift_return_value (GET_MODE (decl_rtl), true, real_decl_rtl);
5523 else if (GET_CODE (real_decl_rtl) == PARALLEL)
5525 /* If expand_function_start has created a PARALLEL for decl_rtl,
5526 move the result to the real return registers. Otherwise, do
5527 a group load from decl_rtl for a named return. */
5528 if (GET_CODE (decl_rtl) == PARALLEL)
5529 emit_group_move (real_decl_rtl, decl_rtl);
5530 else
5531 emit_group_load (real_decl_rtl, decl_rtl,
5532 TREE_TYPE (decl_result),
5533 int_size_in_bytes (TREE_TYPE (decl_result)));
5535 /* In the case of complex integer modes smaller than a word, we'll
5536 need to generate some non-trivial bitfield insertions. Do that
5537 on a pseudo and not the hard register. */
5538 else if (GET_CODE (decl_rtl) == CONCAT
5539 && is_complex_int_mode (GET_MODE (decl_rtl), &cmode)
5540 && GET_MODE_BITSIZE (cmode) <= BITS_PER_WORD)
5542 int old_generating_concat_p;
5543 rtx tmp;
5545 old_generating_concat_p = generating_concat_p;
5546 generating_concat_p = 0;
5547 tmp = gen_reg_rtx (GET_MODE (decl_rtl));
5548 generating_concat_p = old_generating_concat_p;
5550 emit_move_insn (tmp, decl_rtl);
5551 emit_move_insn (real_decl_rtl, tmp);
5553 /* If a named return value dumped decl_return to memory, then
5554 we may need to re-do the PROMOTE_MODE signed/unsigned
5555 extension. */
5556 else if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
5558 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
5559 promote_function_mode (TREE_TYPE (decl_result),
5560 GET_MODE (decl_rtl), &unsignedp,
5561 TREE_TYPE (current_function_decl), 1);
5563 convert_move (real_decl_rtl, decl_rtl, unsignedp);
5565 else
5566 emit_move_insn (real_decl_rtl, decl_rtl);
5570 /* If returning a structure, arrange to return the address of the value
5571 in a place where debuggers expect to find it.
5573 If returning a structure PCC style,
5574 the caller also depends on this value.
5575 And cfun->returns_pcc_struct is not necessarily set. */
5576 if ((cfun->returns_struct || cfun->returns_pcc_struct)
5577 && !targetm.calls.omit_struct_return_reg)
5579 rtx value_address = DECL_RTL (DECL_RESULT (current_function_decl));
5580 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
5581 rtx outgoing;
5583 if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
5584 type = TREE_TYPE (type);
5585 else
5586 value_address = XEXP (value_address, 0);
5588 outgoing = targetm.calls.function_value (build_pointer_type (type),
5589 current_function_decl, true);
5591 /* Mark this as a function return value so integrate will delete the
5592 assignment and USE below when inlining this function. */
5593 REG_FUNCTION_VALUE_P (outgoing) = 1;
5595 /* The address may be ptr_mode and OUTGOING may be Pmode. */
5596 scalar_int_mode mode = as_a <scalar_int_mode> (GET_MODE (outgoing));
5597 value_address = convert_memory_address (mode, value_address);
5599 emit_move_insn (outgoing, value_address);
5601 /* Show return register used to hold result (in this case the address
5602 of the result. */
5603 crtl->return_rtx = outgoing;
5606 /* Emit the actual code to clobber return register. Don't emit
5607 it if clobber_after is a barrier, then the previous basic block
5608 certainly doesn't fall thru into the exit block. */
5609 if (!BARRIER_P (clobber_after))
5611 start_sequence ();
5612 clobber_return_register ();
5613 rtx_insn *seq = get_insns ();
5614 end_sequence ();
5616 emit_insn_after (seq, clobber_after);
5619 /* Output the label for the naked return from the function. */
5620 if (naked_return_label)
5621 emit_label (naked_return_label);
5623 /* @@@ This is a kludge. We want to ensure that instructions that
5624 may trap are not moved into the epilogue by scheduling, because
5625 we don't always emit unwind information for the epilogue. */
5626 if (cfun->can_throw_non_call_exceptions
5627 && targetm_common.except_unwind_info (&global_options) != UI_SJLJ)
5628 emit_insn (gen_blockage ());
5630 /* If stack protection is enabled for this function, check the guard. */
5631 if (crtl->stack_protect_guard && targetm.stack_protect_runtime_enabled_p ())
5632 stack_protect_epilogue ();
5634 /* If we had calls to alloca, and this machine needs
5635 an accurate stack pointer to exit the function,
5636 insert some code to save and restore the stack pointer. */
5637 if (! EXIT_IGNORE_STACK
5638 && cfun->calls_alloca)
5640 rtx tem = 0;
5642 start_sequence ();
5643 emit_stack_save (SAVE_FUNCTION, &tem);
5644 rtx_insn *seq = get_insns ();
5645 end_sequence ();
5646 emit_insn_before (seq, parm_birth_insn);
5648 emit_stack_restore (SAVE_FUNCTION, tem);
5651 /* ??? This should no longer be necessary since stupid is no longer with
5652 us, but there are some parts of the compiler (eg reload_combine, and
5653 sh mach_dep_reorg) that still try and compute their own lifetime info
5654 instead of using the general framework. */
5655 use_return_register ();
5659 get_arg_pointer_save_area (void)
5661 rtx ret = arg_pointer_save_area;
5663 if (! ret)
5665 ret = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
5666 arg_pointer_save_area = ret;
5669 if (! crtl->arg_pointer_save_area_init)
5671 /* Save the arg pointer at the beginning of the function. The
5672 generated stack slot may not be a valid memory address, so we
5673 have to check it and fix it if necessary. */
5674 start_sequence ();
5675 emit_move_insn (validize_mem (copy_rtx (ret)),
5676 crtl->args.internal_arg_pointer);
5677 rtx_insn *seq = get_insns ();
5678 end_sequence ();
5680 push_topmost_sequence ();
5681 emit_insn_after (seq, entry_of_function ());
5682 pop_topmost_sequence ();
5684 crtl->arg_pointer_save_area_init = true;
5687 return ret;
5691 /* If debugging dumps are requested, dump information about how the
5692 target handled -fstack-check=clash for the prologue.
5694 PROBES describes what if any probes were emitted.
5696 RESIDUALS indicates if the prologue had any residual allocation
5697 (i.e. total allocation was not a multiple of PROBE_INTERVAL). */
5699 void
5700 dump_stack_clash_frame_info (enum stack_clash_probes probes, bool residuals)
5702 if (!dump_file)
5703 return;
5705 switch (probes)
5707 case NO_PROBE_NO_FRAME:
5708 fprintf (dump_file,
5709 "Stack clash no probe no stack adjustment in prologue.\n");
5710 break;
5711 case NO_PROBE_SMALL_FRAME:
5712 fprintf (dump_file,
5713 "Stack clash no probe small stack adjustment in prologue.\n");
5714 break;
5715 case PROBE_INLINE:
5716 fprintf (dump_file, "Stack clash inline probes in prologue.\n");
5717 break;
5718 case PROBE_LOOP:
5719 fprintf (dump_file, "Stack clash probe loop in prologue.\n");
5720 break;
5723 if (residuals)
5724 fprintf (dump_file, "Stack clash residual allocation in prologue.\n");
5725 else
5726 fprintf (dump_file, "Stack clash no residual allocation in prologue.\n");
5728 if (frame_pointer_needed)
5729 fprintf (dump_file, "Stack clash frame pointer needed.\n");
5730 else
5731 fprintf (dump_file, "Stack clash no frame pointer needed.\n");
5733 if (TREE_THIS_VOLATILE (cfun->decl))
5734 fprintf (dump_file,
5735 "Stack clash noreturn prologue, assuming no implicit"
5736 " probes in caller.\n");
5737 else
5738 fprintf (dump_file,
5739 "Stack clash not noreturn prologue.\n");
5742 /* Add a list of INSNS to the hash HASHP, possibly allocating HASHP
5743 for the first time. */
5745 static void
5746 record_insns (rtx_insn *insns, rtx end, hash_table<insn_cache_hasher> **hashp)
5748 rtx_insn *tmp;
5749 hash_table<insn_cache_hasher> *hash = *hashp;
5751 if (hash == NULL)
5752 *hashp = hash = hash_table<insn_cache_hasher>::create_ggc (17);
5754 for (tmp = insns; tmp != end; tmp = NEXT_INSN (tmp))
5756 rtx *slot = hash->find_slot (tmp, INSERT);
5757 gcc_assert (*slot == NULL);
5758 *slot = tmp;
5762 /* INSN has been duplicated or replaced by as COPY, perhaps by duplicating a
5763 basic block, splitting or peepholes. If INSN is a prologue or epilogue
5764 insn, then record COPY as well. */
5766 void
5767 maybe_copy_prologue_epilogue_insn (rtx insn, rtx copy)
5769 hash_table<insn_cache_hasher> *hash;
5770 rtx *slot;
5772 hash = epilogue_insn_hash;
5773 if (!hash || !hash->find (insn))
5775 hash = prologue_insn_hash;
5776 if (!hash || !hash->find (insn))
5777 return;
5780 slot = hash->find_slot (copy, INSERT);
5781 gcc_assert (*slot == NULL);
5782 *slot = copy;
5785 /* Determine if any INSNs in HASH are, or are part of, INSN. Because
5786 we can be running after reorg, SEQUENCE rtl is possible. */
5788 static bool
5789 contains (const rtx_insn *insn, hash_table<insn_cache_hasher> *hash)
5791 if (hash == NULL)
5792 return false;
5794 if (NONJUMP_INSN_P (insn) && GET_CODE (PATTERN (insn)) == SEQUENCE)
5796 rtx_sequence *seq = as_a <rtx_sequence *> (PATTERN (insn));
5797 int i;
5798 for (i = seq->len () - 1; i >= 0; i--)
5799 if (hash->find (seq->element (i)))
5800 return true;
5801 return false;
5804 return hash->find (const_cast<rtx_insn *> (insn)) != NULL;
5808 prologue_contains (const rtx_insn *insn)
5810 return contains (insn, prologue_insn_hash);
5814 epilogue_contains (const rtx_insn *insn)
5816 return contains (insn, epilogue_insn_hash);
5820 prologue_epilogue_contains (const rtx_insn *insn)
5822 if (contains (insn, prologue_insn_hash))
5823 return 1;
5824 if (contains (insn, epilogue_insn_hash))
5825 return 1;
5826 return 0;
5829 void
5830 record_prologue_seq (rtx_insn *seq)
5832 record_insns (seq, NULL, &prologue_insn_hash);
5835 void
5836 record_epilogue_seq (rtx_insn *seq)
5838 record_insns (seq, NULL, &epilogue_insn_hash);
5841 /* Set JUMP_LABEL for a return insn. */
5843 void
5844 set_return_jump_label (rtx_insn *returnjump)
5846 rtx pat = PATTERN (returnjump);
5847 if (GET_CODE (pat) == PARALLEL)
5848 pat = XVECEXP (pat, 0, 0);
5849 if (ANY_RETURN_P (pat))
5850 JUMP_LABEL (returnjump) = pat;
5851 else
5852 JUMP_LABEL (returnjump) = ret_rtx;
5855 /* Return a sequence to be used as the split prologue for the current
5856 function, or NULL. */
5858 static rtx_insn *
5859 make_split_prologue_seq (void)
5861 if (!flag_split_stack
5862 || lookup_attribute ("no_split_stack", DECL_ATTRIBUTES (cfun->decl)))
5863 return NULL;
5865 start_sequence ();
5866 emit_insn (targetm.gen_split_stack_prologue ());
5867 rtx_insn *seq = get_insns ();
5868 end_sequence ();
5870 record_insns (seq, NULL, &prologue_insn_hash);
5871 set_insn_locations (seq, prologue_location);
5873 return seq;
5876 /* Return a sequence to be used as the prologue for the current function,
5877 or NULL. */
5879 static rtx_insn *
5880 make_prologue_seq (void)
5882 if (!targetm.have_prologue ())
5883 return NULL;
5885 start_sequence ();
5886 rtx_insn *seq = targetm.gen_prologue ();
5887 emit_insn (seq);
5889 /* Insert an explicit USE for the frame pointer
5890 if the profiling is on and the frame pointer is required. */
5891 if (crtl->profile && frame_pointer_needed)
5892 emit_use (hard_frame_pointer_rtx);
5894 /* Retain a map of the prologue insns. */
5895 record_insns (seq, NULL, &prologue_insn_hash);
5896 emit_note (NOTE_INSN_PROLOGUE_END);
5898 /* Ensure that instructions are not moved into the prologue when
5899 profiling is on. The call to the profiling routine can be
5900 emitted within the live range of a call-clobbered register. */
5901 if (!targetm.profile_before_prologue () && crtl->profile)
5902 emit_insn (gen_blockage ());
5904 seq = get_insns ();
5905 end_sequence ();
5906 set_insn_locations (seq, prologue_location);
5908 return seq;
5911 /* Return a sequence to be used as the epilogue for the current function,
5912 or NULL. */
5914 static rtx_insn *
5915 make_epilogue_seq (void)
5917 if (!targetm.have_epilogue ())
5918 return NULL;
5920 start_sequence ();
5921 emit_note (NOTE_INSN_EPILOGUE_BEG);
5922 rtx_insn *seq = targetm.gen_epilogue ();
5923 if (seq)
5924 emit_jump_insn (seq);
5926 /* Retain a map of the epilogue insns. */
5927 record_insns (seq, NULL, &epilogue_insn_hash);
5928 set_insn_locations (seq, epilogue_location);
5930 seq = get_insns ();
5931 rtx_insn *returnjump = get_last_insn ();
5932 end_sequence ();
5934 if (JUMP_P (returnjump))
5935 set_return_jump_label (returnjump);
5937 return seq;
5941 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
5942 this into place with notes indicating where the prologue ends and where
5943 the epilogue begins. Update the basic block information when possible.
5945 Notes on epilogue placement:
5946 There are several kinds of edges to the exit block:
5947 * a single fallthru edge from LAST_BB
5948 * possibly, edges from blocks containing sibcalls
5949 * possibly, fake edges from infinite loops
5951 The epilogue is always emitted on the fallthru edge from the last basic
5952 block in the function, LAST_BB, into the exit block.
5954 If LAST_BB is empty except for a label, it is the target of every
5955 other basic block in the function that ends in a return. If a
5956 target has a return or simple_return pattern (possibly with
5957 conditional variants), these basic blocks can be changed so that a
5958 return insn is emitted into them, and their target is adjusted to
5959 the real exit block.
5961 Notes on shrink wrapping: We implement a fairly conservative
5962 version of shrink-wrapping rather than the textbook one. We only
5963 generate a single prologue and a single epilogue. This is
5964 sufficient to catch a number of interesting cases involving early
5965 exits.
5967 First, we identify the blocks that require the prologue to occur before
5968 them. These are the ones that modify a call-saved register, or reference
5969 any of the stack or frame pointer registers. To simplify things, we then
5970 mark everything reachable from these blocks as also requiring a prologue.
5971 This takes care of loops automatically, and avoids the need to examine
5972 whether MEMs reference the frame, since it is sufficient to check for
5973 occurrences of the stack or frame pointer.
5975 We then compute the set of blocks for which the need for a prologue
5976 is anticipatable (borrowing terminology from the shrink-wrapping
5977 description in Muchnick's book). These are the blocks which either
5978 require a prologue themselves, or those that have only successors
5979 where the prologue is anticipatable. The prologue needs to be
5980 inserted on all edges from BB1->BB2 where BB2 is in ANTIC and BB1
5981 is not. For the moment, we ensure that only one such edge exists.
5983 The epilogue is placed as described above, but we make a
5984 distinction between inserting return and simple_return patterns
5985 when modifying other blocks that end in a return. Blocks that end
5986 in a sibcall omit the sibcall_epilogue if the block is not in
5987 ANTIC. */
5989 void
5990 thread_prologue_and_epilogue_insns (void)
5992 df_analyze ();
5994 /* Can't deal with multiple successors of the entry block at the
5995 moment. Function should always have at least one entry
5996 point. */
5997 gcc_assert (single_succ_p (ENTRY_BLOCK_PTR_FOR_FN (cfun)));
5999 edge entry_edge = single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun));
6000 edge orig_entry_edge = entry_edge;
6002 rtx_insn *split_prologue_seq = make_split_prologue_seq ();
6003 rtx_insn *prologue_seq = make_prologue_seq ();
6004 rtx_insn *epilogue_seq = make_epilogue_seq ();
6006 /* Try to perform a kind of shrink-wrapping, making sure the
6007 prologue/epilogue is emitted only around those parts of the
6008 function that require it. */
6009 try_shrink_wrapping (&entry_edge, prologue_seq);
6011 /* If the target can handle splitting the prologue/epilogue into separate
6012 components, try to shrink-wrap these components separately. */
6013 try_shrink_wrapping_separate (entry_edge->dest);
6015 /* If that did anything for any component we now need the generate the
6016 "main" prologue again. Because some targets require some of these
6017 to be called in a specific order (i386 requires the split prologue
6018 to be first, for example), we create all three sequences again here.
6019 If this does not work for some target, that target should not enable
6020 separate shrink-wrapping. */
6021 if (crtl->shrink_wrapped_separate)
6023 split_prologue_seq = make_split_prologue_seq ();
6024 prologue_seq = make_prologue_seq ();
6025 epilogue_seq = make_epilogue_seq ();
6028 rtl_profile_for_bb (EXIT_BLOCK_PTR_FOR_FN (cfun));
6030 /* A small fib -- epilogue is not yet completed, but we wish to re-use
6031 this marker for the splits of EH_RETURN patterns, and nothing else
6032 uses the flag in the meantime. */
6033 epilogue_completed = 1;
6035 /* Find non-fallthru edges that end with EH_RETURN instructions. On
6036 some targets, these get split to a special version of the epilogue
6037 code. In order to be able to properly annotate these with unwind
6038 info, try to split them now. If we get a valid split, drop an
6039 EPILOGUE_BEG note and mark the insns as epilogue insns. */
6040 edge e;
6041 edge_iterator ei;
6042 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
6044 rtx_insn *prev, *last, *trial;
6046 if (e->flags & EDGE_FALLTHRU)
6047 continue;
6048 last = BB_END (e->src);
6049 if (!eh_returnjump_p (last))
6050 continue;
6052 prev = PREV_INSN (last);
6053 trial = try_split (PATTERN (last), last, 1);
6054 if (trial == last)
6055 continue;
6057 record_insns (NEXT_INSN (prev), NEXT_INSN (trial), &epilogue_insn_hash);
6058 emit_note_after (NOTE_INSN_EPILOGUE_BEG, prev);
6061 edge exit_fallthru_edge = find_fallthru_edge (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds);
6063 if (exit_fallthru_edge)
6065 if (epilogue_seq)
6067 insert_insn_on_edge (epilogue_seq, exit_fallthru_edge);
6068 commit_edge_insertions ();
6070 /* The epilogue insns we inserted may cause the exit edge to no longer
6071 be fallthru. */
6072 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
6074 if (((e->flags & EDGE_FALLTHRU) != 0)
6075 && returnjump_p (BB_END (e->src)))
6076 e->flags &= ~EDGE_FALLTHRU;
6079 else if (next_active_insn (BB_END (exit_fallthru_edge->src)))
6081 /* We have a fall-through edge to the exit block, the source is not
6082 at the end of the function, and there will be an assembler epilogue
6083 at the end of the function.
6084 We can't use force_nonfallthru here, because that would try to
6085 use return. Inserting a jump 'by hand' is extremely messy, so
6086 we take advantage of cfg_layout_finalize using
6087 fixup_fallthru_exit_predecessor. */
6088 cfg_layout_initialize (0);
6089 basic_block cur_bb;
6090 FOR_EACH_BB_FN (cur_bb, cfun)
6091 if (cur_bb->index >= NUM_FIXED_BLOCKS
6092 && cur_bb->next_bb->index >= NUM_FIXED_BLOCKS)
6093 cur_bb->aux = cur_bb->next_bb;
6094 cfg_layout_finalize ();
6098 /* Insert the prologue. */
6100 rtl_profile_for_bb (ENTRY_BLOCK_PTR_FOR_FN (cfun));
6102 if (split_prologue_seq || prologue_seq)
6104 rtx_insn *split_prologue_insn = split_prologue_seq;
6105 if (split_prologue_seq)
6107 while (split_prologue_insn && !NONDEBUG_INSN_P (split_prologue_insn))
6108 split_prologue_insn = NEXT_INSN (split_prologue_insn);
6109 insert_insn_on_edge (split_prologue_seq, orig_entry_edge);
6112 rtx_insn *prologue_insn = prologue_seq;
6113 if (prologue_seq)
6115 while (prologue_insn && !NONDEBUG_INSN_P (prologue_insn))
6116 prologue_insn = NEXT_INSN (prologue_insn);
6117 insert_insn_on_edge (prologue_seq, entry_edge);
6120 commit_edge_insertions ();
6122 /* Look for basic blocks within the prologue insns. */
6123 if (split_prologue_insn
6124 && BLOCK_FOR_INSN (split_prologue_insn) == NULL)
6125 split_prologue_insn = NULL;
6126 if (prologue_insn
6127 && BLOCK_FOR_INSN (prologue_insn) == NULL)
6128 prologue_insn = NULL;
6129 if (split_prologue_insn || prologue_insn)
6131 auto_sbitmap blocks (last_basic_block_for_fn (cfun));
6132 bitmap_clear (blocks);
6133 if (split_prologue_insn)
6134 bitmap_set_bit (blocks,
6135 BLOCK_FOR_INSN (split_prologue_insn)->index);
6136 if (prologue_insn)
6137 bitmap_set_bit (blocks, BLOCK_FOR_INSN (prologue_insn)->index);
6138 find_many_sub_basic_blocks (blocks);
6142 default_rtl_profile ();
6144 /* Emit sibling epilogues before any sibling call sites. */
6145 for (ei = ei_start (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds);
6146 (e = ei_safe_edge (ei));
6147 ei_next (&ei))
6149 /* Skip those already handled, the ones that run without prologue. */
6150 if (e->flags & EDGE_IGNORE)
6152 e->flags &= ~EDGE_IGNORE;
6153 continue;
6156 rtx_insn *insn = BB_END (e->src);
6158 if (!(CALL_P (insn) && SIBLING_CALL_P (insn)))
6159 continue;
6161 if (rtx_insn *ep_seq = targetm.gen_sibcall_epilogue ())
6163 start_sequence ();
6164 emit_note (NOTE_INSN_EPILOGUE_BEG);
6165 emit_insn (ep_seq);
6166 rtx_insn *seq = get_insns ();
6167 end_sequence ();
6169 /* Retain a map of the epilogue insns. Used in life analysis to
6170 avoid getting rid of sibcall epilogue insns. Do this before we
6171 actually emit the sequence. */
6172 record_insns (seq, NULL, &epilogue_insn_hash);
6173 set_insn_locations (seq, epilogue_location);
6175 emit_insn_before (seq, insn);
6179 if (epilogue_seq)
6181 rtx_insn *insn, *next;
6183 /* Similarly, move any line notes that appear after the epilogue.
6184 There is no need, however, to be quite so anal about the existence
6185 of such a note. Also possibly move
6186 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
6187 info generation. */
6188 for (insn = epilogue_seq; insn; insn = next)
6190 next = NEXT_INSN (insn);
6191 if (NOTE_P (insn)
6192 && (NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG))
6193 reorder_insns (insn, insn, PREV_INSN (epilogue_seq));
6197 /* Threading the prologue and epilogue changes the artificial refs
6198 in the entry and exit blocks. */
6199 epilogue_completed = 1;
6200 df_update_entry_exit_and_calls ();
6203 /* Reposition the prologue-end and epilogue-begin notes after
6204 instruction scheduling. */
6206 void
6207 reposition_prologue_and_epilogue_notes (void)
6209 if (!targetm.have_prologue ()
6210 && !targetm.have_epilogue ()
6211 && !targetm.have_sibcall_epilogue ())
6212 return;
6214 /* Since the hash table is created on demand, the fact that it is
6215 non-null is a signal that it is non-empty. */
6216 if (prologue_insn_hash != NULL)
6218 size_t len = prologue_insn_hash->elements ();
6219 rtx_insn *insn, *last = NULL, *note = NULL;
6221 /* Scan from the beginning until we reach the last prologue insn. */
6222 /* ??? While we do have the CFG intact, there are two problems:
6223 (1) The prologue can contain loops (typically probing the stack),
6224 which means that the end of the prologue isn't in the first bb.
6225 (2) Sometimes the PROLOGUE_END note gets pushed into the next bb. */
6226 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
6228 if (NOTE_P (insn))
6230 if (NOTE_KIND (insn) == NOTE_INSN_PROLOGUE_END)
6231 note = insn;
6233 else if (contains (insn, prologue_insn_hash))
6235 last = insn;
6236 if (--len == 0)
6237 break;
6241 if (last)
6243 if (note == NULL)
6245 /* Scan forward looking for the PROLOGUE_END note. It should
6246 be right at the beginning of the block, possibly with other
6247 insn notes that got moved there. */
6248 for (note = NEXT_INSN (last); ; note = NEXT_INSN (note))
6250 if (NOTE_P (note)
6251 && NOTE_KIND (note) == NOTE_INSN_PROLOGUE_END)
6252 break;
6256 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
6257 if (LABEL_P (last))
6258 last = NEXT_INSN (last);
6259 reorder_insns (note, note, last);
6263 if (epilogue_insn_hash != NULL)
6265 edge_iterator ei;
6266 edge e;
6268 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
6270 rtx_insn *insn, *first = NULL, *note = NULL;
6271 basic_block bb = e->src;
6273 /* Scan from the beginning until we reach the first epilogue insn. */
6274 FOR_BB_INSNS (bb, insn)
6276 if (NOTE_P (insn))
6278 if (NOTE_KIND (insn) == NOTE_INSN_EPILOGUE_BEG)
6280 note = insn;
6281 if (first != NULL)
6282 break;
6285 else if (first == NULL && contains (insn, epilogue_insn_hash))
6287 first = insn;
6288 if (note != NULL)
6289 break;
6293 if (note)
6295 /* If the function has a single basic block, and no real
6296 epilogue insns (e.g. sibcall with no cleanup), the
6297 epilogue note can get scheduled before the prologue
6298 note. If we have frame related prologue insns, having
6299 them scanned during the epilogue will result in a crash.
6300 In this case re-order the epilogue note to just before
6301 the last insn in the block. */
6302 if (first == NULL)
6303 first = BB_END (bb);
6305 if (PREV_INSN (first) != note)
6306 reorder_insns (note, note, PREV_INSN (first));
6312 /* Returns the name of function declared by FNDECL. */
6313 const char *
6314 fndecl_name (tree fndecl)
6316 if (fndecl == NULL)
6317 return "(nofn)";
6318 return lang_hooks.decl_printable_name (fndecl, 1);
6321 /* Returns the name of function FN. */
6322 const char *
6323 function_name (struct function *fn)
6325 tree fndecl = (fn == NULL) ? NULL : fn->decl;
6326 return fndecl_name (fndecl);
6329 /* Returns the name of the current function. */
6330 const char *
6331 current_function_name (void)
6333 return function_name (cfun);
6337 static unsigned int
6338 rest_of_handle_check_leaf_regs (void)
6340 #ifdef LEAF_REGISTERS
6341 crtl->uses_only_leaf_regs
6342 = optimize > 0 && only_leaf_regs_used () && leaf_function_p ();
6343 #endif
6344 return 0;
6347 /* Insert a TYPE into the used types hash table of CFUN. */
6349 static void
6350 used_types_insert_helper (tree type, struct function *func)
6352 if (type != NULL && func != NULL)
6354 if (func->used_types_hash == NULL)
6355 func->used_types_hash = hash_set<tree>::create_ggc (37);
6357 func->used_types_hash->add (type);
6361 /* Given a type, insert it into the used hash table in cfun. */
6362 void
6363 used_types_insert (tree t)
6365 while (POINTER_TYPE_P (t) || TREE_CODE (t) == ARRAY_TYPE)
6366 if (TYPE_NAME (t))
6367 break;
6368 else
6369 t = TREE_TYPE (t);
6370 if (TREE_CODE (t) == ERROR_MARK)
6371 return;
6372 if (TYPE_NAME (t) == NULL_TREE
6373 || TYPE_NAME (t) == TYPE_NAME (TYPE_MAIN_VARIANT (t)))
6374 t = TYPE_MAIN_VARIANT (t);
6375 if (debug_info_level > DINFO_LEVEL_NONE)
6377 if (cfun)
6378 used_types_insert_helper (t, cfun);
6379 else
6381 /* So this might be a type referenced by a global variable.
6382 Record that type so that we can later decide to emit its
6383 debug information. */
6384 vec_safe_push (types_used_by_cur_var_decl, t);
6389 /* Helper to Hash a struct types_used_by_vars_entry. */
6391 static hashval_t
6392 hash_types_used_by_vars_entry (const struct types_used_by_vars_entry *entry)
6394 gcc_assert (entry && entry->var_decl && entry->type);
6396 return iterative_hash_object (entry->type,
6397 iterative_hash_object (entry->var_decl, 0));
6400 /* Hash function of the types_used_by_vars_entry hash table. */
6402 hashval_t
6403 used_type_hasher::hash (types_used_by_vars_entry *entry)
6405 return hash_types_used_by_vars_entry (entry);
6408 /*Equality function of the types_used_by_vars_entry hash table. */
6410 bool
6411 used_type_hasher::equal (types_used_by_vars_entry *e1,
6412 types_used_by_vars_entry *e2)
6414 return (e1->var_decl == e2->var_decl && e1->type == e2->type);
6417 /* Inserts an entry into the types_used_by_vars_hash hash table. */
6419 void
6420 types_used_by_var_decl_insert (tree type, tree var_decl)
6422 if (type != NULL && var_decl != NULL)
6424 types_used_by_vars_entry **slot;
6425 struct types_used_by_vars_entry e;
6426 e.var_decl = var_decl;
6427 e.type = type;
6428 if (types_used_by_vars_hash == NULL)
6429 types_used_by_vars_hash
6430 = hash_table<used_type_hasher>::create_ggc (37);
6432 slot = types_used_by_vars_hash->find_slot (&e, INSERT);
6433 if (*slot == NULL)
6435 struct types_used_by_vars_entry *entry;
6436 entry = ggc_alloc<types_used_by_vars_entry> ();
6437 entry->type = type;
6438 entry->var_decl = var_decl;
6439 *slot = entry;
6444 namespace {
6446 const pass_data pass_data_leaf_regs =
6448 RTL_PASS, /* type */
6449 "*leaf_regs", /* name */
6450 OPTGROUP_NONE, /* optinfo_flags */
6451 TV_NONE, /* tv_id */
6452 0, /* properties_required */
6453 0, /* properties_provided */
6454 0, /* properties_destroyed */
6455 0, /* todo_flags_start */
6456 0, /* todo_flags_finish */
6459 class pass_leaf_regs : public rtl_opt_pass
6461 public:
6462 pass_leaf_regs (gcc::context *ctxt)
6463 : rtl_opt_pass (pass_data_leaf_regs, ctxt)
6466 /* opt_pass methods: */
6467 virtual unsigned int execute (function *)
6469 return rest_of_handle_check_leaf_regs ();
6472 }; // class pass_leaf_regs
6474 } // anon namespace
6476 rtl_opt_pass *
6477 make_pass_leaf_regs (gcc::context *ctxt)
6479 return new pass_leaf_regs (ctxt);
6482 static unsigned int
6483 rest_of_handle_thread_prologue_and_epilogue (void)
6485 /* prepare_shrink_wrap is sensitive to the block structure of the control
6486 flow graph, so clean it up first. */
6487 if (optimize)
6488 cleanup_cfg (0);
6490 /* On some machines, the prologue and epilogue code, or parts thereof,
6491 can be represented as RTL. Doing so lets us schedule insns between
6492 it and the rest of the code and also allows delayed branch
6493 scheduling to operate in the epilogue. */
6494 thread_prologue_and_epilogue_insns ();
6496 /* Some non-cold blocks may now be only reachable from cold blocks.
6497 Fix that up. */
6498 fixup_partitions ();
6500 /* Shrink-wrapping can result in unreachable edges in the epilogue,
6501 see PR57320. */
6502 cleanup_cfg (optimize ? CLEANUP_EXPENSIVE : 0);
6504 /* The stack usage info is finalized during prologue expansion. */
6505 if (flag_stack_usage_info)
6506 output_stack_usage ();
6508 return 0;
6511 namespace {
6513 const pass_data pass_data_thread_prologue_and_epilogue =
6515 RTL_PASS, /* type */
6516 "pro_and_epilogue", /* name */
6517 OPTGROUP_NONE, /* optinfo_flags */
6518 TV_THREAD_PROLOGUE_AND_EPILOGUE, /* tv_id */
6519 0, /* properties_required */
6520 0, /* properties_provided */
6521 0, /* properties_destroyed */
6522 0, /* todo_flags_start */
6523 ( TODO_df_verify | TODO_df_finish ), /* todo_flags_finish */
6526 class pass_thread_prologue_and_epilogue : public rtl_opt_pass
6528 public:
6529 pass_thread_prologue_and_epilogue (gcc::context *ctxt)
6530 : rtl_opt_pass (pass_data_thread_prologue_and_epilogue, ctxt)
6533 /* opt_pass methods: */
6534 virtual unsigned int execute (function *)
6536 return rest_of_handle_thread_prologue_and_epilogue ();
6539 }; // class pass_thread_prologue_and_epilogue
6541 } // anon namespace
6543 rtl_opt_pass *
6544 make_pass_thread_prologue_and_epilogue (gcc::context *ctxt)
6546 return new pass_thread_prologue_and_epilogue (ctxt);
6550 /* This mini-pass fixes fall-out from SSA in asm statements that have
6551 in-out constraints. Say you start with
6553 orig = inout;
6554 asm ("": "+mr" (inout));
6555 use (orig);
6557 which is transformed very early to use explicit output and match operands:
6559 orig = inout;
6560 asm ("": "=mr" (inout) : "0" (inout));
6561 use (orig);
6563 Or, after SSA and copyprop,
6565 asm ("": "=mr" (inout_2) : "0" (inout_1));
6566 use (inout_1);
6568 Clearly inout_2 and inout_1 can't be coalesced easily anymore, as
6569 they represent two separate values, so they will get different pseudo
6570 registers during expansion. Then, since the two operands need to match
6571 per the constraints, but use different pseudo registers, reload can
6572 only register a reload for these operands. But reloads can only be
6573 satisfied by hardregs, not by memory, so we need a register for this
6574 reload, just because we are presented with non-matching operands.
6575 So, even though we allow memory for this operand, no memory can be
6576 used for it, just because the two operands don't match. This can
6577 cause reload failures on register-starved targets.
6579 So it's a symptom of reload not being able to use memory for reloads
6580 or, alternatively it's also a symptom of both operands not coming into
6581 reload as matching (in which case the pseudo could go to memory just
6582 fine, as the alternative allows it, and no reload would be necessary).
6583 We fix the latter problem here, by transforming
6585 asm ("": "=mr" (inout_2) : "0" (inout_1));
6587 back to
6589 inout_2 = inout_1;
6590 asm ("": "=mr" (inout_2) : "0" (inout_2)); */
6592 static void
6593 match_asm_constraints_1 (rtx_insn *insn, rtx *p_sets, int noutputs)
6595 int i;
6596 bool changed = false;
6597 rtx op = SET_SRC (p_sets[0]);
6598 int ninputs = ASM_OPERANDS_INPUT_LENGTH (op);
6599 rtvec inputs = ASM_OPERANDS_INPUT_VEC (op);
6600 bool *output_matched = XALLOCAVEC (bool, noutputs);
6602 memset (output_matched, 0, noutputs * sizeof (bool));
6603 for (i = 0; i < ninputs; i++)
6605 rtx input, output;
6606 rtx_insn *insns;
6607 const char *constraint = ASM_OPERANDS_INPUT_CONSTRAINT (op, i);
6608 char *end;
6609 int match, j;
6611 if (*constraint == '%')
6612 constraint++;
6614 match = strtoul (constraint, &end, 10);
6615 if (end == constraint)
6616 continue;
6618 gcc_assert (match < noutputs);
6619 output = SET_DEST (p_sets[match]);
6620 input = RTVEC_ELT (inputs, i);
6621 /* Only do the transformation for pseudos. */
6622 if (! REG_P (output)
6623 || rtx_equal_p (output, input)
6624 || (GET_MODE (input) != VOIDmode
6625 && GET_MODE (input) != GET_MODE (output)))
6626 continue;
6628 /* We can't do anything if the output is also used as input,
6629 as we're going to overwrite it. */
6630 for (j = 0; j < ninputs; j++)
6631 if (reg_overlap_mentioned_p (output, RTVEC_ELT (inputs, j)))
6632 break;
6633 if (j != ninputs)
6634 continue;
6636 /* Avoid changing the same input several times. For
6637 asm ("" : "=mr" (out1), "=mr" (out2) : "0" (in), "1" (in));
6638 only change in once (to out1), rather than changing it
6639 first to out1 and afterwards to out2. */
6640 if (i > 0)
6642 for (j = 0; j < noutputs; j++)
6643 if (output_matched[j] && input == SET_DEST (p_sets[j]))
6644 break;
6645 if (j != noutputs)
6646 continue;
6648 output_matched[match] = true;
6650 start_sequence ();
6651 emit_move_insn (output, input);
6652 insns = get_insns ();
6653 end_sequence ();
6654 emit_insn_before (insns, insn);
6656 /* Now replace all mentions of the input with output. We can't
6657 just replace the occurrence in inputs[i], as the register might
6658 also be used in some other input (or even in an address of an
6659 output), which would mean possibly increasing the number of
6660 inputs by one (namely 'output' in addition), which might pose
6661 a too complicated problem for reload to solve. E.g. this situation:
6663 asm ("" : "=r" (output), "=m" (input) : "0" (input))
6665 Here 'input' is used in two occurrences as input (once for the
6666 input operand, once for the address in the second output operand).
6667 If we would replace only the occurrence of the input operand (to
6668 make the matching) we would be left with this:
6670 output = input
6671 asm ("" : "=r" (output), "=m" (input) : "0" (output))
6673 Now we suddenly have two different input values (containing the same
6674 value, but different pseudos) where we formerly had only one.
6675 With more complicated asms this might lead to reload failures
6676 which wouldn't have happen without this pass. So, iterate over
6677 all operands and replace all occurrences of the register used. */
6678 for (j = 0; j < noutputs; j++)
6679 if (!rtx_equal_p (SET_DEST (p_sets[j]), input)
6680 && reg_overlap_mentioned_p (input, SET_DEST (p_sets[j])))
6681 SET_DEST (p_sets[j]) = replace_rtx (SET_DEST (p_sets[j]),
6682 input, output);
6683 for (j = 0; j < ninputs; j++)
6684 if (reg_overlap_mentioned_p (input, RTVEC_ELT (inputs, j)))
6685 RTVEC_ELT (inputs, j) = replace_rtx (RTVEC_ELT (inputs, j),
6686 input, output);
6688 changed = true;
6691 if (changed)
6692 df_insn_rescan (insn);
6695 /* Add the decl D to the local_decls list of FUN. */
6697 void
6698 add_local_decl (struct function *fun, tree d)
6700 gcc_assert (VAR_P (d));
6701 vec_safe_push (fun->local_decls, d);
6704 namespace {
6706 const pass_data pass_data_match_asm_constraints =
6708 RTL_PASS, /* type */
6709 "asmcons", /* name */
6710 OPTGROUP_NONE, /* optinfo_flags */
6711 TV_NONE, /* tv_id */
6712 0, /* properties_required */
6713 0, /* properties_provided */
6714 0, /* properties_destroyed */
6715 0, /* todo_flags_start */
6716 0, /* todo_flags_finish */
6719 class pass_match_asm_constraints : public rtl_opt_pass
6721 public:
6722 pass_match_asm_constraints (gcc::context *ctxt)
6723 : rtl_opt_pass (pass_data_match_asm_constraints, ctxt)
6726 /* opt_pass methods: */
6727 virtual unsigned int execute (function *);
6729 }; // class pass_match_asm_constraints
6731 unsigned
6732 pass_match_asm_constraints::execute (function *fun)
6734 basic_block bb;
6735 rtx_insn *insn;
6736 rtx pat, *p_sets;
6737 int noutputs;
6739 if (!crtl->has_asm_statement)
6740 return 0;
6742 df_set_flags (DF_DEFER_INSN_RESCAN);
6743 FOR_EACH_BB_FN (bb, fun)
6745 FOR_BB_INSNS (bb, insn)
6747 if (!INSN_P (insn))
6748 continue;
6750 pat = PATTERN (insn);
6751 if (GET_CODE (pat) == PARALLEL)
6752 p_sets = &XVECEXP (pat, 0, 0), noutputs = XVECLEN (pat, 0);
6753 else if (GET_CODE (pat) == SET)
6754 p_sets = &PATTERN (insn), noutputs = 1;
6755 else
6756 continue;
6758 if (GET_CODE (*p_sets) == SET
6759 && GET_CODE (SET_SRC (*p_sets)) == ASM_OPERANDS)
6760 match_asm_constraints_1 (insn, p_sets, noutputs);
6764 return TODO_df_finish;
6767 } // anon namespace
6769 rtl_opt_pass *
6770 make_pass_match_asm_constraints (gcc::context *ctxt)
6772 return new pass_match_asm_constraints (ctxt);
6776 #include "gt-function.h"