* i386.c (has_dispatch): Disable for Ryzen.
[official-gcc.git] / gcc / function.c
blobc03e2ac514270e32da3c16439f6f38f169b40f1f
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 = 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 + 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 = 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 (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
2088 return 1;
2090 if (targetm.calls.return_in_memory (type, fntype))
2091 return 1;
2093 /* Make sure we have suitable call-clobbered regs to return
2094 the value in; if not, we must return it in memory. */
2095 reg = hard_function_value (type, 0, fntype, 0);
2097 /* If we have something other than a REG (e.g. a PARALLEL), then assume
2098 it is OK. */
2099 if (!REG_P (reg))
2100 return 0;
2102 regno = REGNO (reg);
2103 nregs = hard_regno_nregs (regno, TYPE_MODE (type));
2104 for (i = 0; i < nregs; i++)
2105 if (! call_used_regs[regno + i])
2106 return 1;
2108 return 0;
2111 /* Return true if we should assign DECL a pseudo register; false if it
2112 should live on the local stack. */
2114 bool
2115 use_register_for_decl (const_tree decl)
2117 if (TREE_CODE (decl) == SSA_NAME)
2119 /* We often try to use the SSA_NAME, instead of its underlying
2120 decl, to get type information and guide decisions, to avoid
2121 differences of behavior between anonymous and named
2122 variables, but in this one case we have to go for the actual
2123 variable if there is one. The main reason is that, at least
2124 at -O0, we want to place user variables on the stack, but we
2125 don't mind using pseudos for anonymous or ignored temps.
2126 Should we take the SSA_NAME, we'd conclude all SSA_NAMEs
2127 should go in pseudos, whereas their corresponding variables
2128 might have to go on the stack. So, disregarding the decl
2129 here would negatively impact debug info at -O0, enable
2130 coalescing between SSA_NAMEs that ought to get different
2131 stack/pseudo assignments, and get the incoming argument
2132 processing thoroughly confused by PARM_DECLs expected to live
2133 in stack slots but assigned to pseudos. */
2134 if (!SSA_NAME_VAR (decl))
2135 return TYPE_MODE (TREE_TYPE (decl)) != BLKmode
2136 && !(flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)));
2138 decl = SSA_NAME_VAR (decl);
2141 /* Honor volatile. */
2142 if (TREE_SIDE_EFFECTS (decl))
2143 return false;
2145 /* Honor addressability. */
2146 if (TREE_ADDRESSABLE (decl))
2147 return false;
2149 /* RESULT_DECLs are a bit special in that they're assigned without
2150 regard to use_register_for_decl, but we generally only store in
2151 them. If we coalesce their SSA NAMEs, we'd better return a
2152 result that matches the assignment in expand_function_start. */
2153 if (TREE_CODE (decl) == RESULT_DECL)
2155 /* If it's not an aggregate, we're going to use a REG or a
2156 PARALLEL containing a REG. */
2157 if (!aggregate_value_p (decl, current_function_decl))
2158 return true;
2160 /* If expand_function_start determines the return value, we'll
2161 use MEM if it's not by reference. */
2162 if (cfun->returns_pcc_struct
2163 || (targetm.calls.struct_value_rtx
2164 (TREE_TYPE (current_function_decl), 1)))
2165 return DECL_BY_REFERENCE (decl);
2167 /* Otherwise, we're taking an extra all.function_result_decl
2168 argument. It's set up in assign_parms_augmented_arg_list,
2169 under the (negated) conditions above, and then it's used to
2170 set up the RESULT_DECL rtl in assign_params, after looping
2171 over all parameters. Now, if the RESULT_DECL is not by
2172 reference, we'll use a MEM either way. */
2173 if (!DECL_BY_REFERENCE (decl))
2174 return false;
2176 /* Otherwise, if RESULT_DECL is DECL_BY_REFERENCE, it will take
2177 the function_result_decl's assignment. Since it's a pointer,
2178 we can short-circuit a number of the tests below, and we must
2179 duplicat e them because we don't have the
2180 function_result_decl to test. */
2181 if (!targetm.calls.allocate_stack_slots_for_args ())
2182 return true;
2183 /* We don't set DECL_IGNORED_P for the function_result_decl. */
2184 if (optimize)
2185 return true;
2186 /* We don't set DECL_REGISTER for the function_result_decl. */
2187 return false;
2190 /* Decl is implicitly addressible by bound stores and loads
2191 if it is an aggregate holding bounds. */
2192 if (chkp_function_instrumented_p (current_function_decl)
2193 && TREE_TYPE (decl)
2194 && !BOUNDED_P (decl)
2195 && chkp_type_has_pointer (TREE_TYPE (decl)))
2196 return false;
2198 /* Only register-like things go in registers. */
2199 if (DECL_MODE (decl) == BLKmode)
2200 return false;
2202 /* If -ffloat-store specified, don't put explicit float variables
2203 into registers. */
2204 /* ??? This should be checked after DECL_ARTIFICIAL, but tree-ssa
2205 propagates values across these stores, and it probably shouldn't. */
2206 if (flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)))
2207 return false;
2209 if (!targetm.calls.allocate_stack_slots_for_args ())
2210 return true;
2212 /* If we're not interested in tracking debugging information for
2213 this decl, then we can certainly put it in a register. */
2214 if (DECL_IGNORED_P (decl))
2215 return true;
2217 if (optimize)
2218 return true;
2220 if (!DECL_REGISTER (decl))
2221 return false;
2223 /* When not optimizing, disregard register keyword for types that
2224 could have methods, otherwise the methods won't be callable from
2225 the debugger. */
2226 if (RECORD_OR_UNION_TYPE_P (TREE_TYPE (decl)))
2227 return false;
2229 return true;
2232 /* Structures to communicate between the subroutines of assign_parms.
2233 The first holds data persistent across all parameters, the second
2234 is cleared out for each parameter. */
2236 struct assign_parm_data_all
2238 /* When INIT_CUMULATIVE_ARGS gets revamped, allocating CUMULATIVE_ARGS
2239 should become a job of the target or otherwise encapsulated. */
2240 CUMULATIVE_ARGS args_so_far_v;
2241 cumulative_args_t args_so_far;
2242 struct args_size stack_args_size;
2243 tree function_result_decl;
2244 tree orig_fnargs;
2245 rtx_insn *first_conversion_insn;
2246 rtx_insn *last_conversion_insn;
2247 HOST_WIDE_INT pretend_args_size;
2248 HOST_WIDE_INT extra_pretend_bytes;
2249 int reg_parm_stack_space;
2252 struct assign_parm_data_one
2254 tree nominal_type;
2255 tree passed_type;
2256 rtx entry_parm;
2257 rtx stack_parm;
2258 machine_mode nominal_mode;
2259 machine_mode passed_mode;
2260 machine_mode promoted_mode;
2261 struct locate_and_pad_arg_data locate;
2262 int partial;
2263 BOOL_BITFIELD named_arg : 1;
2264 BOOL_BITFIELD passed_pointer : 1;
2265 BOOL_BITFIELD on_stack : 1;
2266 BOOL_BITFIELD loaded_in_reg : 1;
2269 struct bounds_parm_data
2271 assign_parm_data_one parm_data;
2272 tree bounds_parm;
2273 tree ptr_parm;
2274 rtx ptr_entry;
2275 int bound_no;
2278 /* A subroutine of assign_parms. Initialize ALL. */
2280 static void
2281 assign_parms_initialize_all (struct assign_parm_data_all *all)
2283 tree fntype ATTRIBUTE_UNUSED;
2285 memset (all, 0, sizeof (*all));
2287 fntype = TREE_TYPE (current_function_decl);
2289 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
2290 INIT_CUMULATIVE_INCOMING_ARGS (all->args_so_far_v, fntype, NULL_RTX);
2291 #else
2292 INIT_CUMULATIVE_ARGS (all->args_so_far_v, fntype, NULL_RTX,
2293 current_function_decl, -1);
2294 #endif
2295 all->args_so_far = pack_cumulative_args (&all->args_so_far_v);
2297 #ifdef INCOMING_REG_PARM_STACK_SPACE
2298 all->reg_parm_stack_space
2299 = INCOMING_REG_PARM_STACK_SPACE (current_function_decl);
2300 #endif
2303 /* If ARGS contains entries with complex types, split the entry into two
2304 entries of the component type. Return a new list of substitutions are
2305 needed, else the old list. */
2307 static void
2308 split_complex_args (vec<tree> *args)
2310 unsigned i;
2311 tree p;
2313 FOR_EACH_VEC_ELT (*args, i, p)
2315 tree type = TREE_TYPE (p);
2316 if (TREE_CODE (type) == COMPLEX_TYPE
2317 && targetm.calls.split_complex_arg (type))
2319 tree decl;
2320 tree subtype = TREE_TYPE (type);
2321 bool addressable = TREE_ADDRESSABLE (p);
2323 /* Rewrite the PARM_DECL's type with its component. */
2324 p = copy_node (p);
2325 TREE_TYPE (p) = subtype;
2326 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
2327 SET_DECL_MODE (p, VOIDmode);
2328 DECL_SIZE (p) = NULL;
2329 DECL_SIZE_UNIT (p) = NULL;
2330 /* If this arg must go in memory, put it in a pseudo here.
2331 We can't allow it to go in memory as per normal parms,
2332 because the usual place might not have the imag part
2333 adjacent to the real part. */
2334 DECL_ARTIFICIAL (p) = addressable;
2335 DECL_IGNORED_P (p) = addressable;
2336 TREE_ADDRESSABLE (p) = 0;
2337 layout_decl (p, 0);
2338 (*args)[i] = p;
2340 /* Build a second synthetic decl. */
2341 decl = build_decl (EXPR_LOCATION (p),
2342 PARM_DECL, NULL_TREE, subtype);
2343 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
2344 DECL_ARTIFICIAL (decl) = addressable;
2345 DECL_IGNORED_P (decl) = addressable;
2346 layout_decl (decl, 0);
2347 args->safe_insert (++i, decl);
2352 /* A subroutine of assign_parms. Adjust the parameter list to incorporate
2353 the hidden struct return argument, and (abi willing) complex args.
2354 Return the new parameter list. */
2356 static vec<tree>
2357 assign_parms_augmented_arg_list (struct assign_parm_data_all *all)
2359 tree fndecl = current_function_decl;
2360 tree fntype = TREE_TYPE (fndecl);
2361 vec<tree> fnargs = vNULL;
2362 tree arg;
2364 for (arg = DECL_ARGUMENTS (fndecl); arg; arg = DECL_CHAIN (arg))
2365 fnargs.safe_push (arg);
2367 all->orig_fnargs = DECL_ARGUMENTS (fndecl);
2369 /* If struct value address is treated as the first argument, make it so. */
2370 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
2371 && ! cfun->returns_pcc_struct
2372 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
2374 tree type = build_pointer_type (TREE_TYPE (fntype));
2375 tree decl;
2377 decl = build_decl (DECL_SOURCE_LOCATION (fndecl),
2378 PARM_DECL, get_identifier (".result_ptr"), type);
2379 DECL_ARG_TYPE (decl) = type;
2380 DECL_ARTIFICIAL (decl) = 1;
2381 DECL_NAMELESS (decl) = 1;
2382 TREE_CONSTANT (decl) = 1;
2383 /* We don't set DECL_IGNORED_P or DECL_REGISTER here. If this
2384 changes, the end of the RESULT_DECL handling block in
2385 use_register_for_decl must be adjusted to match. */
2387 DECL_CHAIN (decl) = all->orig_fnargs;
2388 all->orig_fnargs = decl;
2389 fnargs.safe_insert (0, decl);
2391 all->function_result_decl = decl;
2393 /* If function is instrumented then bounds of the
2394 passed structure address is the second argument. */
2395 if (chkp_function_instrumented_p (fndecl))
2397 decl = build_decl (DECL_SOURCE_LOCATION (fndecl),
2398 PARM_DECL, get_identifier (".result_bnd"),
2399 pointer_bounds_type_node);
2400 DECL_ARG_TYPE (decl) = pointer_bounds_type_node;
2401 DECL_ARTIFICIAL (decl) = 1;
2402 DECL_NAMELESS (decl) = 1;
2403 TREE_CONSTANT (decl) = 1;
2405 DECL_CHAIN (decl) = DECL_CHAIN (all->orig_fnargs);
2406 DECL_CHAIN (all->orig_fnargs) = decl;
2407 fnargs.safe_insert (1, decl);
2411 /* If the target wants to split complex arguments into scalars, do so. */
2412 if (targetm.calls.split_complex_arg)
2413 split_complex_args (&fnargs);
2415 return fnargs;
2418 /* A subroutine of assign_parms. Examine PARM and pull out type and mode
2419 data for the parameter. Incorporate ABI specifics such as pass-by-
2420 reference and type promotion. */
2422 static void
2423 assign_parm_find_data_types (struct assign_parm_data_all *all, tree parm,
2424 struct assign_parm_data_one *data)
2426 tree nominal_type, passed_type;
2427 machine_mode nominal_mode, passed_mode, promoted_mode;
2428 int unsignedp;
2430 memset (data, 0, sizeof (*data));
2432 /* NAMED_ARG is a misnomer. We really mean 'non-variadic'. */
2433 if (!cfun->stdarg)
2434 data->named_arg = 1; /* No variadic parms. */
2435 else if (DECL_CHAIN (parm))
2436 data->named_arg = 1; /* Not the last non-variadic parm. */
2437 else if (targetm.calls.strict_argument_naming (all->args_so_far))
2438 data->named_arg = 1; /* Only variadic ones are unnamed. */
2439 else
2440 data->named_arg = 0; /* Treat as variadic. */
2442 nominal_type = TREE_TYPE (parm);
2443 passed_type = DECL_ARG_TYPE (parm);
2445 /* Look out for errors propagating this far. Also, if the parameter's
2446 type is void then its value doesn't matter. */
2447 if (TREE_TYPE (parm) == error_mark_node
2448 /* This can happen after weird syntax errors
2449 or if an enum type is defined among the parms. */
2450 || TREE_CODE (parm) != PARM_DECL
2451 || passed_type == NULL
2452 || VOID_TYPE_P (nominal_type))
2454 nominal_type = passed_type = void_type_node;
2455 nominal_mode = passed_mode = promoted_mode = VOIDmode;
2456 goto egress;
2459 /* Find mode of arg as it is passed, and mode of arg as it should be
2460 during execution of this function. */
2461 passed_mode = TYPE_MODE (passed_type);
2462 nominal_mode = TYPE_MODE (nominal_type);
2464 /* If the parm is to be passed as a transparent union or record, use the
2465 type of the first field for the tests below. We have already verified
2466 that the modes are the same. */
2467 if ((TREE_CODE (passed_type) == UNION_TYPE
2468 || TREE_CODE (passed_type) == RECORD_TYPE)
2469 && TYPE_TRANSPARENT_AGGR (passed_type))
2470 passed_type = TREE_TYPE (first_field (passed_type));
2472 /* See if this arg was passed by invisible reference. */
2473 if (pass_by_reference (&all->args_so_far_v, passed_mode,
2474 passed_type, data->named_arg))
2476 passed_type = nominal_type = build_pointer_type (passed_type);
2477 data->passed_pointer = true;
2478 passed_mode = nominal_mode = TYPE_MODE (nominal_type);
2481 /* Find mode as it is passed by the ABI. */
2482 unsignedp = TYPE_UNSIGNED (passed_type);
2483 promoted_mode = promote_function_mode (passed_type, passed_mode, &unsignedp,
2484 TREE_TYPE (current_function_decl), 0);
2486 egress:
2487 data->nominal_type = nominal_type;
2488 data->passed_type = passed_type;
2489 data->nominal_mode = nominal_mode;
2490 data->passed_mode = passed_mode;
2491 data->promoted_mode = promoted_mode;
2494 /* A subroutine of assign_parms. Invoke setup_incoming_varargs. */
2496 static void
2497 assign_parms_setup_varargs (struct assign_parm_data_all *all,
2498 struct assign_parm_data_one *data, bool no_rtl)
2500 int varargs_pretend_bytes = 0;
2502 targetm.calls.setup_incoming_varargs (all->args_so_far,
2503 data->promoted_mode,
2504 data->passed_type,
2505 &varargs_pretend_bytes, no_rtl);
2507 /* If the back-end has requested extra stack space, record how much is
2508 needed. Do not change pretend_args_size otherwise since it may be
2509 nonzero from an earlier partial argument. */
2510 if (varargs_pretend_bytes > 0)
2511 all->pretend_args_size = varargs_pretend_bytes;
2514 /* A subroutine of assign_parms. Set DATA->ENTRY_PARM corresponding to
2515 the incoming location of the current parameter. */
2517 static void
2518 assign_parm_find_entry_rtl (struct assign_parm_data_all *all,
2519 struct assign_parm_data_one *data)
2521 HOST_WIDE_INT pretend_bytes = 0;
2522 rtx entry_parm;
2523 bool in_regs;
2525 if (data->promoted_mode == VOIDmode)
2527 data->entry_parm = data->stack_parm = const0_rtx;
2528 return;
2531 entry_parm = targetm.calls.function_incoming_arg (all->args_so_far,
2532 data->promoted_mode,
2533 data->passed_type,
2534 data->named_arg);
2536 if (entry_parm == 0)
2537 data->promoted_mode = data->passed_mode;
2539 /* Determine parm's home in the stack, in case it arrives in the stack
2540 or we should pretend it did. Compute the stack position and rtx where
2541 the argument arrives and its size.
2543 There is one complexity here: If this was a parameter that would
2544 have been passed in registers, but wasn't only because it is
2545 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2546 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2547 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of 0
2548 as it was the previous time. */
2549 in_regs = (entry_parm != 0) || POINTER_BOUNDS_TYPE_P (data->passed_type);
2550 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2551 in_regs = true;
2552 #endif
2553 if (!in_regs && !data->named_arg)
2555 if (targetm.calls.pretend_outgoing_varargs_named (all->args_so_far))
2557 rtx tem;
2558 tem = targetm.calls.function_incoming_arg (all->args_so_far,
2559 data->promoted_mode,
2560 data->passed_type, true);
2561 in_regs = tem != NULL;
2565 /* If this parameter was passed both in registers and in the stack, use
2566 the copy on the stack. */
2567 if (targetm.calls.must_pass_in_stack (data->promoted_mode,
2568 data->passed_type))
2569 entry_parm = 0;
2571 if (entry_parm)
2573 int partial;
2575 partial = targetm.calls.arg_partial_bytes (all->args_so_far,
2576 data->promoted_mode,
2577 data->passed_type,
2578 data->named_arg);
2579 data->partial = partial;
2581 /* The caller might already have allocated stack space for the
2582 register parameters. */
2583 if (partial != 0 && all->reg_parm_stack_space == 0)
2585 /* Part of this argument is passed in registers and part
2586 is passed on the stack. Ask the prologue code to extend
2587 the stack part so that we can recreate the full value.
2589 PRETEND_BYTES is the size of the registers we need to store.
2590 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
2591 stack space that the prologue should allocate.
2593 Internally, gcc assumes that the argument pointer is aligned
2594 to STACK_BOUNDARY bits. This is used both for alignment
2595 optimizations (see init_emit) and to locate arguments that are
2596 aligned to more than PARM_BOUNDARY bits. We must preserve this
2597 invariant by rounding CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to
2598 a stack boundary. */
2600 /* We assume at most one partial arg, and it must be the first
2601 argument on the stack. */
2602 gcc_assert (!all->extra_pretend_bytes && !all->pretend_args_size);
2604 pretend_bytes = partial;
2605 all->pretend_args_size = CEIL_ROUND (pretend_bytes, STACK_BYTES);
2607 /* We want to align relative to the actual stack pointer, so
2608 don't include this in the stack size until later. */
2609 all->extra_pretend_bytes = all->pretend_args_size;
2613 locate_and_pad_parm (data->promoted_mode, data->passed_type, in_regs,
2614 all->reg_parm_stack_space,
2615 entry_parm ? data->partial : 0, current_function_decl,
2616 &all->stack_args_size, &data->locate);
2618 /* Update parm_stack_boundary if this parameter is passed in the
2619 stack. */
2620 if (!in_regs && crtl->parm_stack_boundary < data->locate.boundary)
2621 crtl->parm_stack_boundary = data->locate.boundary;
2623 /* Adjust offsets to include the pretend args. */
2624 pretend_bytes = all->extra_pretend_bytes - pretend_bytes;
2625 data->locate.slot_offset.constant += pretend_bytes;
2626 data->locate.offset.constant += pretend_bytes;
2628 data->entry_parm = entry_parm;
2631 /* A subroutine of assign_parms. If there is actually space on the stack
2632 for this parm, count it in stack_args_size and return true. */
2634 static bool
2635 assign_parm_is_stack_parm (struct assign_parm_data_all *all,
2636 struct assign_parm_data_one *data)
2638 /* Bounds are never passed on the stack to keep compatibility
2639 with not instrumented code. */
2640 if (POINTER_BOUNDS_TYPE_P (data->passed_type))
2641 return false;
2642 /* Trivially true if we've no incoming register. */
2643 else if (data->entry_parm == NULL)
2645 /* Also true if we're partially in registers and partially not,
2646 since we've arranged to drop the entire argument on the stack. */
2647 else if (data->partial != 0)
2649 /* Also true if the target says that it's passed in both registers
2650 and on the stack. */
2651 else if (GET_CODE (data->entry_parm) == PARALLEL
2652 && XEXP (XVECEXP (data->entry_parm, 0, 0), 0) == NULL_RTX)
2654 /* Also true if the target says that there's stack allocated for
2655 all register parameters. */
2656 else if (all->reg_parm_stack_space > 0)
2658 /* Otherwise, no, this parameter has no ABI defined stack slot. */
2659 else
2660 return false;
2662 all->stack_args_size.constant += data->locate.size.constant;
2663 if (data->locate.size.var)
2664 ADD_PARM_SIZE (all->stack_args_size, data->locate.size.var);
2666 return true;
2669 /* A subroutine of assign_parms. Given that this parameter is allocated
2670 stack space by the ABI, find it. */
2672 static void
2673 assign_parm_find_stack_rtl (tree parm, struct assign_parm_data_one *data)
2675 rtx offset_rtx, stack_parm;
2676 unsigned int align, boundary;
2678 /* If we're passing this arg using a reg, make its stack home the
2679 aligned stack slot. */
2680 if (data->entry_parm)
2681 offset_rtx = ARGS_SIZE_RTX (data->locate.slot_offset);
2682 else
2683 offset_rtx = ARGS_SIZE_RTX (data->locate.offset);
2685 stack_parm = crtl->args.internal_arg_pointer;
2686 if (offset_rtx != const0_rtx)
2687 stack_parm = gen_rtx_PLUS (Pmode, stack_parm, offset_rtx);
2688 stack_parm = gen_rtx_MEM (data->promoted_mode, stack_parm);
2690 if (!data->passed_pointer)
2692 set_mem_attributes (stack_parm, parm, 1);
2693 /* set_mem_attributes could set MEM_SIZE to the passed mode's size,
2694 while promoted mode's size is needed. */
2695 if (data->promoted_mode != BLKmode
2696 && data->promoted_mode != DECL_MODE (parm))
2698 set_mem_size (stack_parm, GET_MODE_SIZE (data->promoted_mode));
2699 if (MEM_EXPR (stack_parm) && MEM_OFFSET_KNOWN_P (stack_parm))
2701 int offset = subreg_lowpart_offset (DECL_MODE (parm),
2702 data->promoted_mode);
2703 if (offset)
2704 set_mem_offset (stack_parm, MEM_OFFSET (stack_parm) - offset);
2709 boundary = data->locate.boundary;
2710 align = BITS_PER_UNIT;
2712 /* If we're padding upward, we know that the alignment of the slot
2713 is TARGET_FUNCTION_ARG_BOUNDARY. If we're using slot_offset, we're
2714 intentionally forcing upward padding. Otherwise we have to come
2715 up with a guess at the alignment based on OFFSET_RTX. */
2716 if (data->locate.where_pad != PAD_DOWNWARD || data->entry_parm)
2717 align = boundary;
2718 else if (CONST_INT_P (offset_rtx))
2720 align = INTVAL (offset_rtx) * BITS_PER_UNIT | boundary;
2721 align = least_bit_hwi (align);
2723 set_mem_align (stack_parm, align);
2725 if (data->entry_parm)
2726 set_reg_attrs_for_parm (data->entry_parm, stack_parm);
2728 data->stack_parm = stack_parm;
2731 /* A subroutine of assign_parms. Adjust DATA->ENTRY_RTL such that it's
2732 always valid and contiguous. */
2734 static void
2735 assign_parm_adjust_entry_rtl (struct assign_parm_data_one *data)
2737 rtx entry_parm = data->entry_parm;
2738 rtx stack_parm = data->stack_parm;
2740 /* If this parm was passed part in regs and part in memory, pretend it
2741 arrived entirely in memory by pushing the register-part onto the stack.
2742 In the special case of a DImode or DFmode that is split, we could put
2743 it together in a pseudoreg directly, but for now that's not worth
2744 bothering with. */
2745 if (data->partial != 0)
2747 /* Handle calls that pass values in multiple non-contiguous
2748 locations. The Irix 6 ABI has examples of this. */
2749 if (GET_CODE (entry_parm) == PARALLEL)
2750 emit_group_store (validize_mem (copy_rtx (stack_parm)), entry_parm,
2751 data->passed_type,
2752 int_size_in_bytes (data->passed_type));
2753 else
2755 gcc_assert (data->partial % UNITS_PER_WORD == 0);
2756 move_block_from_reg (REGNO (entry_parm),
2757 validize_mem (copy_rtx (stack_parm)),
2758 data->partial / UNITS_PER_WORD);
2761 entry_parm = stack_parm;
2764 /* If we didn't decide this parm came in a register, by default it came
2765 on the stack. */
2766 else if (entry_parm == NULL)
2767 entry_parm = stack_parm;
2769 /* When an argument is passed in multiple locations, we can't make use
2770 of this information, but we can save some copying if the whole argument
2771 is passed in a single register. */
2772 else if (GET_CODE (entry_parm) == PARALLEL
2773 && data->nominal_mode != BLKmode
2774 && data->passed_mode != BLKmode)
2776 size_t i, len = XVECLEN (entry_parm, 0);
2778 for (i = 0; i < len; i++)
2779 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
2780 && REG_P (XEXP (XVECEXP (entry_parm, 0, i), 0))
2781 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
2782 == data->passed_mode)
2783 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
2785 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
2786 break;
2790 data->entry_parm = entry_parm;
2793 /* A subroutine of assign_parms. Reconstitute any values which were
2794 passed in multiple registers and would fit in a single register. */
2796 static void
2797 assign_parm_remove_parallels (struct assign_parm_data_one *data)
2799 rtx entry_parm = data->entry_parm;
2801 /* Convert the PARALLEL to a REG of the same mode as the parallel.
2802 This can be done with register operations rather than on the
2803 stack, even if we will store the reconstituted parameter on the
2804 stack later. */
2805 if (GET_CODE (entry_parm) == PARALLEL && GET_MODE (entry_parm) != BLKmode)
2807 rtx parmreg = gen_reg_rtx (GET_MODE (entry_parm));
2808 emit_group_store (parmreg, entry_parm, data->passed_type,
2809 GET_MODE_SIZE (GET_MODE (entry_parm)));
2810 entry_parm = parmreg;
2813 data->entry_parm = entry_parm;
2816 /* A subroutine of assign_parms. Adjust DATA->STACK_RTL such that it's
2817 always valid and properly aligned. */
2819 static void
2820 assign_parm_adjust_stack_rtl (struct assign_parm_data_one *data)
2822 rtx stack_parm = data->stack_parm;
2824 /* If we can't trust the parm stack slot to be aligned enough for its
2825 ultimate type, don't use that slot after entry. We'll make another
2826 stack slot, if we need one. */
2827 if (stack_parm
2828 && ((STRICT_ALIGNMENT
2829 && GET_MODE_ALIGNMENT (data->nominal_mode) > MEM_ALIGN (stack_parm))
2830 || (data->nominal_type
2831 && TYPE_ALIGN (data->nominal_type) > MEM_ALIGN (stack_parm)
2832 && MEM_ALIGN (stack_parm) < PREFERRED_STACK_BOUNDARY)))
2833 stack_parm = NULL;
2835 /* If parm was passed in memory, and we need to convert it on entry,
2836 don't store it back in that same slot. */
2837 else if (data->entry_parm == stack_parm
2838 && data->nominal_mode != BLKmode
2839 && data->nominal_mode != data->passed_mode)
2840 stack_parm = NULL;
2842 /* If stack protection is in effect for this function, don't leave any
2843 pointers in their passed stack slots. */
2844 else if (crtl->stack_protect_guard
2845 && (flag_stack_protect == 2
2846 || data->passed_pointer
2847 || POINTER_TYPE_P (data->nominal_type)))
2848 stack_parm = NULL;
2850 data->stack_parm = stack_parm;
2853 /* A subroutine of assign_parms. Return true if the current parameter
2854 should be stored as a BLKmode in the current frame. */
2856 static bool
2857 assign_parm_setup_block_p (struct assign_parm_data_one *data)
2859 if (data->nominal_mode == BLKmode)
2860 return true;
2861 if (GET_MODE (data->entry_parm) == BLKmode)
2862 return true;
2864 #ifdef BLOCK_REG_PADDING
2865 /* Only assign_parm_setup_block knows how to deal with register arguments
2866 that are padded at the least significant end. */
2867 if (REG_P (data->entry_parm)
2868 && GET_MODE_SIZE (data->promoted_mode) < UNITS_PER_WORD
2869 && (BLOCK_REG_PADDING (data->passed_mode, data->passed_type, 1)
2870 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
2871 return true;
2872 #endif
2874 return false;
2877 /* A subroutine of assign_parms. Arrange for the parameter to be
2878 present and valid in DATA->STACK_RTL. */
2880 static void
2881 assign_parm_setup_block (struct assign_parm_data_all *all,
2882 tree parm, struct assign_parm_data_one *data)
2884 rtx entry_parm = data->entry_parm;
2885 rtx stack_parm = data->stack_parm;
2886 rtx target_reg = NULL_RTX;
2887 bool in_conversion_seq = false;
2888 HOST_WIDE_INT size;
2889 HOST_WIDE_INT size_stored;
2891 if (GET_CODE (entry_parm) == PARALLEL)
2892 entry_parm = emit_group_move_into_temps (entry_parm);
2894 /* If we want the parameter in a pseudo, don't use a stack slot. */
2895 if (is_gimple_reg (parm) && use_register_for_decl (parm))
2897 tree def = ssa_default_def (cfun, parm);
2898 gcc_assert (def);
2899 machine_mode mode = promote_ssa_mode (def, NULL);
2900 rtx reg = gen_reg_rtx (mode);
2901 if (GET_CODE (reg) != CONCAT)
2902 stack_parm = reg;
2903 else
2905 target_reg = reg;
2906 /* Avoid allocating a stack slot, if there isn't one
2907 preallocated by the ABI. It might seem like we should
2908 always prefer a pseudo, but converting between
2909 floating-point and integer modes goes through the stack
2910 on various machines, so it's better to use the reserved
2911 stack slot than to risk wasting it and allocating more
2912 for the conversion. */
2913 if (stack_parm == NULL_RTX)
2915 int save = generating_concat_p;
2916 generating_concat_p = 0;
2917 stack_parm = gen_reg_rtx (mode);
2918 generating_concat_p = save;
2921 data->stack_parm = NULL;
2924 size = int_size_in_bytes (data->passed_type);
2925 size_stored = CEIL_ROUND (size, UNITS_PER_WORD);
2926 if (stack_parm == 0)
2928 SET_DECL_ALIGN (parm, MAX (DECL_ALIGN (parm), BITS_PER_WORD));
2929 stack_parm = assign_stack_local (BLKmode, size_stored,
2930 DECL_ALIGN (parm));
2931 if (GET_MODE_SIZE (GET_MODE (entry_parm)) == size)
2932 PUT_MODE (stack_parm, GET_MODE (entry_parm));
2933 set_mem_attributes (stack_parm, parm, 1);
2936 /* If a BLKmode arrives in registers, copy it to a stack slot. Handle
2937 calls that pass values in multiple non-contiguous locations. */
2938 if (REG_P (entry_parm) || GET_CODE (entry_parm) == PARALLEL)
2940 rtx mem;
2942 /* Note that we will be storing an integral number of words.
2943 So we have to be careful to ensure that we allocate an
2944 integral number of words. We do this above when we call
2945 assign_stack_local if space was not allocated in the argument
2946 list. If it was, this will not work if PARM_BOUNDARY is not
2947 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2948 if it becomes a problem. Exception is when BLKmode arrives
2949 with arguments not conforming to word_mode. */
2951 if (data->stack_parm == 0)
2953 else if (GET_CODE (entry_parm) == PARALLEL)
2955 else
2956 gcc_assert (!size || !(PARM_BOUNDARY % BITS_PER_WORD));
2958 mem = validize_mem (copy_rtx (stack_parm));
2960 /* Handle values in multiple non-contiguous locations. */
2961 if (GET_CODE (entry_parm) == PARALLEL && !MEM_P (mem))
2962 emit_group_store (mem, entry_parm, data->passed_type, size);
2963 else if (GET_CODE (entry_parm) == PARALLEL)
2965 push_to_sequence2 (all->first_conversion_insn,
2966 all->last_conversion_insn);
2967 emit_group_store (mem, entry_parm, data->passed_type, size);
2968 all->first_conversion_insn = get_insns ();
2969 all->last_conversion_insn = get_last_insn ();
2970 end_sequence ();
2971 in_conversion_seq = true;
2974 else if (size == 0)
2977 /* If SIZE is that of a mode no bigger than a word, just use
2978 that mode's store operation. */
2979 else if (size <= UNITS_PER_WORD)
2981 unsigned int bits = size * BITS_PER_UNIT;
2982 machine_mode mode = int_mode_for_size (bits, 0).else_blk ();
2984 if (mode != BLKmode
2985 #ifdef BLOCK_REG_PADDING
2986 && (size == UNITS_PER_WORD
2987 || (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2988 != (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
2989 #endif
2992 rtx reg;
2994 /* We are really truncating a word_mode value containing
2995 SIZE bytes into a value of mode MODE. If such an
2996 operation requires no actual instructions, we can refer
2997 to the value directly in mode MODE, otherwise we must
2998 start with the register in word_mode and explicitly
2999 convert it. */
3000 if (targetm.truly_noop_truncation (size * BITS_PER_UNIT,
3001 BITS_PER_WORD))
3002 reg = gen_rtx_REG (mode, REGNO (entry_parm));
3003 else
3005 reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
3006 reg = convert_to_mode (mode, copy_to_reg (reg), 1);
3008 emit_move_insn (change_address (mem, mode, 0), reg);
3011 #ifdef BLOCK_REG_PADDING
3012 /* Storing the register in memory as a full word, as
3013 move_block_from_reg below would do, and then using the
3014 MEM in a smaller mode, has the effect of shifting right
3015 if BYTES_BIG_ENDIAN. If we're bypassing memory, the
3016 shifting must be explicit. */
3017 else if (!MEM_P (mem))
3019 rtx x;
3021 /* If the assert below fails, we should have taken the
3022 mode != BLKmode path above, unless we have downward
3023 padding of smaller-than-word arguments on a machine
3024 with little-endian bytes, which would likely require
3025 additional changes to work correctly. */
3026 gcc_checking_assert (BYTES_BIG_ENDIAN
3027 && (BLOCK_REG_PADDING (mode,
3028 data->passed_type, 1)
3029 == PAD_UPWARD));
3031 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
3033 x = gen_rtx_REG (word_mode, REGNO (entry_parm));
3034 x = expand_shift (RSHIFT_EXPR, word_mode, x, by,
3035 NULL_RTX, 1);
3036 x = force_reg (word_mode, x);
3037 x = gen_lowpart_SUBREG (GET_MODE (mem), x);
3039 emit_move_insn (mem, x);
3041 #endif
3043 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
3044 machine must be aligned to the left before storing
3045 to memory. Note that the previous test doesn't
3046 handle all cases (e.g. SIZE == 3). */
3047 else if (size != UNITS_PER_WORD
3048 #ifdef BLOCK_REG_PADDING
3049 && (BLOCK_REG_PADDING (mode, data->passed_type, 1)
3050 == PAD_DOWNWARD)
3051 #else
3052 && BYTES_BIG_ENDIAN
3053 #endif
3056 rtx tem, x;
3057 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
3058 rtx reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
3060 x = expand_shift (LSHIFT_EXPR, word_mode, reg, by, NULL_RTX, 1);
3061 tem = change_address (mem, word_mode, 0);
3062 emit_move_insn (tem, x);
3064 else
3065 move_block_from_reg (REGNO (entry_parm), mem,
3066 size_stored / UNITS_PER_WORD);
3068 else if (!MEM_P (mem))
3070 gcc_checking_assert (size > UNITS_PER_WORD);
3071 #ifdef BLOCK_REG_PADDING
3072 gcc_checking_assert (BLOCK_REG_PADDING (GET_MODE (mem),
3073 data->passed_type, 0)
3074 == PAD_UPWARD);
3075 #endif
3076 emit_move_insn (mem, entry_parm);
3078 else
3079 move_block_from_reg (REGNO (entry_parm), mem,
3080 size_stored / UNITS_PER_WORD);
3082 else if (data->stack_parm == 0)
3084 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3085 emit_block_move (stack_parm, data->entry_parm, GEN_INT (size),
3086 BLOCK_OP_NORMAL);
3087 all->first_conversion_insn = get_insns ();
3088 all->last_conversion_insn = get_last_insn ();
3089 end_sequence ();
3090 in_conversion_seq = true;
3093 if (target_reg)
3095 if (!in_conversion_seq)
3096 emit_move_insn (target_reg, stack_parm);
3097 else
3099 push_to_sequence2 (all->first_conversion_insn,
3100 all->last_conversion_insn);
3101 emit_move_insn (target_reg, stack_parm);
3102 all->first_conversion_insn = get_insns ();
3103 all->last_conversion_insn = get_last_insn ();
3104 end_sequence ();
3106 stack_parm = target_reg;
3109 data->stack_parm = stack_parm;
3110 set_parm_rtl (parm, stack_parm);
3113 /* A subroutine of assign_parms. Allocate a pseudo to hold the current
3114 parameter. Get it there. Perform all ABI specified conversions. */
3116 static void
3117 assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm,
3118 struct assign_parm_data_one *data)
3120 rtx parmreg, validated_mem;
3121 rtx equiv_stack_parm;
3122 machine_mode promoted_nominal_mode;
3123 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (parm));
3124 bool did_conversion = false;
3125 bool need_conversion, moved;
3126 rtx rtl;
3128 /* Store the parm in a pseudoregister during the function, but we may
3129 need to do it in a wider mode. Using 2 here makes the result
3130 consistent with promote_decl_mode and thus expand_expr_real_1. */
3131 promoted_nominal_mode
3132 = promote_function_mode (data->nominal_type, data->nominal_mode, &unsignedp,
3133 TREE_TYPE (current_function_decl), 2);
3135 parmreg = gen_reg_rtx (promoted_nominal_mode);
3136 if (!DECL_ARTIFICIAL (parm))
3137 mark_user_reg (parmreg);
3139 /* If this was an item that we received a pointer to,
3140 set rtl appropriately. */
3141 if (data->passed_pointer)
3143 rtl = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data->passed_type)), parmreg);
3144 set_mem_attributes (rtl, parm, 1);
3146 else
3147 rtl = parmreg;
3149 assign_parm_remove_parallels (data);
3151 /* Copy the value into the register, thus bridging between
3152 assign_parm_find_data_types and expand_expr_real_1. */
3154 equiv_stack_parm = data->stack_parm;
3155 validated_mem = validize_mem (copy_rtx (data->entry_parm));
3157 need_conversion = (data->nominal_mode != data->passed_mode
3158 || promoted_nominal_mode != data->promoted_mode);
3159 moved = false;
3161 if (need_conversion
3162 && GET_MODE_CLASS (data->nominal_mode) == MODE_INT
3163 && data->nominal_mode == data->passed_mode
3164 && data->nominal_mode == GET_MODE (data->entry_parm))
3166 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
3167 mode, by the caller. We now have to convert it to
3168 NOMINAL_MODE, if different. However, PARMREG may be in
3169 a different mode than NOMINAL_MODE if it is being stored
3170 promoted.
3172 If ENTRY_PARM is a hard register, it might be in a register
3173 not valid for operating in its mode (e.g., an odd-numbered
3174 register for a DFmode). In that case, moves are the only
3175 thing valid, so we can't do a convert from there. This
3176 occurs when the calling sequence allow such misaligned
3177 usages.
3179 In addition, the conversion may involve a call, which could
3180 clobber parameters which haven't been copied to pseudo
3181 registers yet.
3183 First, we try to emit an insn which performs the necessary
3184 conversion. We verify that this insn does not clobber any
3185 hard registers. */
3187 enum insn_code icode;
3188 rtx op0, op1;
3190 icode = can_extend_p (promoted_nominal_mode, data->passed_mode,
3191 unsignedp);
3193 op0 = parmreg;
3194 op1 = validated_mem;
3195 if (icode != CODE_FOR_nothing
3196 && insn_operand_matches (icode, 0, op0)
3197 && insn_operand_matches (icode, 1, op1))
3199 enum rtx_code code = unsignedp ? ZERO_EXTEND : SIGN_EXTEND;
3200 rtx_insn *insn, *insns;
3201 rtx t = op1;
3202 HARD_REG_SET hardregs;
3204 start_sequence ();
3205 /* If op1 is a hard register that is likely spilled, first
3206 force it into a pseudo, otherwise combiner might extend
3207 its lifetime too much. */
3208 if (GET_CODE (t) == SUBREG)
3209 t = SUBREG_REG (t);
3210 if (REG_P (t)
3211 && HARD_REGISTER_P (t)
3212 && ! TEST_HARD_REG_BIT (fixed_reg_set, REGNO (t))
3213 && targetm.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (t))))
3215 t = gen_reg_rtx (GET_MODE (op1));
3216 emit_move_insn (t, op1);
3218 else
3219 t = op1;
3220 rtx_insn *pat = gen_extend_insn (op0, t, promoted_nominal_mode,
3221 data->passed_mode, unsignedp);
3222 emit_insn (pat);
3223 insns = get_insns ();
3225 moved = true;
3226 CLEAR_HARD_REG_SET (hardregs);
3227 for (insn = insns; insn && moved; insn = NEXT_INSN (insn))
3229 if (INSN_P (insn))
3230 note_stores (PATTERN (insn), record_hard_reg_sets,
3231 &hardregs);
3232 if (!hard_reg_set_empty_p (hardregs))
3233 moved = false;
3236 end_sequence ();
3238 if (moved)
3240 emit_insn (insns);
3241 if (equiv_stack_parm != NULL_RTX)
3242 equiv_stack_parm = gen_rtx_fmt_e (code, GET_MODE (parmreg),
3243 equiv_stack_parm);
3248 if (moved)
3249 /* Nothing to do. */
3251 else if (need_conversion)
3253 /* We did not have an insn to convert directly, or the sequence
3254 generated appeared unsafe. We must first copy the parm to a
3255 pseudo reg, and save the conversion until after all
3256 parameters have been moved. */
3258 int save_tree_used;
3259 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
3261 emit_move_insn (tempreg, validated_mem);
3263 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3264 tempreg = convert_to_mode (data->nominal_mode, tempreg, unsignedp);
3266 if (partial_subreg_p (tempreg)
3267 && GET_MODE (tempreg) == data->nominal_mode
3268 && REG_P (SUBREG_REG (tempreg))
3269 && data->nominal_mode == data->passed_mode
3270 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (data->entry_parm))
3272 /* The argument is already sign/zero extended, so note it
3273 into the subreg. */
3274 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
3275 SUBREG_PROMOTED_SET (tempreg, unsignedp);
3278 /* TREE_USED gets set erroneously during expand_assignment. */
3279 save_tree_used = TREE_USED (parm);
3280 SET_DECL_RTL (parm, rtl);
3281 expand_assignment (parm, make_tree (data->nominal_type, tempreg), false);
3282 SET_DECL_RTL (parm, NULL_RTX);
3283 TREE_USED (parm) = save_tree_used;
3284 all->first_conversion_insn = get_insns ();
3285 all->last_conversion_insn = get_last_insn ();
3286 end_sequence ();
3288 did_conversion = true;
3290 else
3291 emit_move_insn (parmreg, validated_mem);
3293 /* If we were passed a pointer but the actual value can safely live
3294 in a register, retrieve it and use it directly. */
3295 if (data->passed_pointer && TYPE_MODE (TREE_TYPE (parm)) != BLKmode)
3297 /* We can't use nominal_mode, because it will have been set to
3298 Pmode above. We must use the actual mode of the parm. */
3299 if (use_register_for_decl (parm))
3301 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
3302 mark_user_reg (parmreg);
3304 else
3306 int align = STACK_SLOT_ALIGNMENT (TREE_TYPE (parm),
3307 TYPE_MODE (TREE_TYPE (parm)),
3308 TYPE_ALIGN (TREE_TYPE (parm)));
3309 parmreg
3310 = assign_stack_local (TYPE_MODE (TREE_TYPE (parm)),
3311 GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (parm))),
3312 align);
3313 set_mem_attributes (parmreg, parm, 1);
3316 /* We need to preserve an address based on VIRTUAL_STACK_VARS_REGNUM for
3317 the debug info in case it is not legitimate. */
3318 if (GET_MODE (parmreg) != GET_MODE (rtl))
3320 rtx tempreg = gen_reg_rtx (GET_MODE (rtl));
3321 int unsigned_p = TYPE_UNSIGNED (TREE_TYPE (parm));
3323 push_to_sequence2 (all->first_conversion_insn,
3324 all->last_conversion_insn);
3325 emit_move_insn (tempreg, rtl);
3326 tempreg = convert_to_mode (GET_MODE (parmreg), tempreg, unsigned_p);
3327 emit_move_insn (MEM_P (parmreg) ? copy_rtx (parmreg) : parmreg,
3328 tempreg);
3329 all->first_conversion_insn = get_insns ();
3330 all->last_conversion_insn = get_last_insn ();
3331 end_sequence ();
3333 did_conversion = true;
3335 else
3336 emit_move_insn (MEM_P (parmreg) ? copy_rtx (parmreg) : parmreg, rtl);
3338 rtl = parmreg;
3340 /* STACK_PARM is the pointer, not the parm, and PARMREG is
3341 now the parm. */
3342 data->stack_parm = NULL;
3345 set_parm_rtl (parm, rtl);
3347 /* Mark the register as eliminable if we did no conversion and it was
3348 copied from memory at a fixed offset, and the arg pointer was not
3349 copied to a pseudo-reg. If the arg pointer is a pseudo reg or the
3350 offset formed an invalid address, such memory-equivalences as we
3351 make here would screw up life analysis for it. */
3352 if (data->nominal_mode == data->passed_mode
3353 && !did_conversion
3354 && data->stack_parm != 0
3355 && MEM_P (data->stack_parm)
3356 && data->locate.offset.var == 0
3357 && reg_mentioned_p (virtual_incoming_args_rtx,
3358 XEXP (data->stack_parm, 0)))
3360 rtx_insn *linsn = get_last_insn ();
3361 rtx_insn *sinsn;
3362 rtx set;
3364 /* Mark complex types separately. */
3365 if (GET_CODE (parmreg) == CONCAT)
3367 scalar_mode submode = GET_MODE_INNER (GET_MODE (parmreg));
3368 int regnor = REGNO (XEXP (parmreg, 0));
3369 int regnoi = REGNO (XEXP (parmreg, 1));
3370 rtx stackr = adjust_address_nv (data->stack_parm, submode, 0);
3371 rtx stacki = adjust_address_nv (data->stack_parm, submode,
3372 GET_MODE_SIZE (submode));
3374 /* Scan backwards for the set of the real and
3375 imaginary parts. */
3376 for (sinsn = linsn; sinsn != 0;
3377 sinsn = prev_nonnote_insn (sinsn))
3379 set = single_set (sinsn);
3380 if (set == 0)
3381 continue;
3383 if (SET_DEST (set) == regno_reg_rtx [regnoi])
3384 set_unique_reg_note (sinsn, REG_EQUIV, stacki);
3385 else if (SET_DEST (set) == regno_reg_rtx [regnor])
3386 set_unique_reg_note (sinsn, REG_EQUIV, stackr);
3389 else
3390 set_dst_reg_note (linsn, REG_EQUIV, equiv_stack_parm, parmreg);
3393 /* For pointer data type, suggest pointer register. */
3394 if (POINTER_TYPE_P (TREE_TYPE (parm)))
3395 mark_reg_pointer (parmreg,
3396 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
3399 /* A subroutine of assign_parms. Allocate stack space to hold the current
3400 parameter. Get it there. Perform all ABI specified conversions. */
3402 static void
3403 assign_parm_setup_stack (struct assign_parm_data_all *all, tree parm,
3404 struct assign_parm_data_one *data)
3406 /* Value must be stored in the stack slot STACK_PARM during function
3407 execution. */
3408 bool to_conversion = false;
3410 assign_parm_remove_parallels (data);
3412 if (data->promoted_mode != data->nominal_mode)
3414 /* Conversion is required. */
3415 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
3417 emit_move_insn (tempreg, validize_mem (copy_rtx (data->entry_parm)));
3419 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
3420 to_conversion = true;
3422 data->entry_parm = convert_to_mode (data->nominal_mode, tempreg,
3423 TYPE_UNSIGNED (TREE_TYPE (parm)));
3425 if (data->stack_parm)
3427 int offset = subreg_lowpart_offset (data->nominal_mode,
3428 GET_MODE (data->stack_parm));
3429 /* ??? This may need a big-endian conversion on sparc64. */
3430 data->stack_parm
3431 = adjust_address (data->stack_parm, data->nominal_mode, 0);
3432 if (offset && MEM_OFFSET_KNOWN_P (data->stack_parm))
3433 set_mem_offset (data->stack_parm,
3434 MEM_OFFSET (data->stack_parm) + offset);
3438 if (data->entry_parm != data->stack_parm)
3440 rtx src, dest;
3442 if (data->stack_parm == 0)
3444 int align = STACK_SLOT_ALIGNMENT (data->passed_type,
3445 GET_MODE (data->entry_parm),
3446 TYPE_ALIGN (data->passed_type));
3447 data->stack_parm
3448 = assign_stack_local (GET_MODE (data->entry_parm),
3449 GET_MODE_SIZE (GET_MODE (data->entry_parm)),
3450 align);
3451 set_mem_attributes (data->stack_parm, parm, 1);
3454 dest = validize_mem (copy_rtx (data->stack_parm));
3455 src = validize_mem (copy_rtx (data->entry_parm));
3457 if (MEM_P (src))
3459 /* Use a block move to handle potentially misaligned entry_parm. */
3460 if (!to_conversion)
3461 push_to_sequence2 (all->first_conversion_insn,
3462 all->last_conversion_insn);
3463 to_conversion = true;
3465 emit_block_move (dest, src,
3466 GEN_INT (int_size_in_bytes (data->passed_type)),
3467 BLOCK_OP_NORMAL);
3469 else
3471 if (!REG_P (src))
3472 src = force_reg (GET_MODE (src), src);
3473 emit_move_insn (dest, src);
3477 if (to_conversion)
3479 all->first_conversion_insn = get_insns ();
3480 all->last_conversion_insn = get_last_insn ();
3481 end_sequence ();
3484 set_parm_rtl (parm, data->stack_parm);
3487 /* A subroutine of assign_parms. If the ABI splits complex arguments, then
3488 undo the frobbing that we did in assign_parms_augmented_arg_list. */
3490 static void
3491 assign_parms_unsplit_complex (struct assign_parm_data_all *all,
3492 vec<tree> fnargs)
3494 tree parm;
3495 tree orig_fnargs = all->orig_fnargs;
3496 unsigned i = 0;
3498 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm), ++i)
3500 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
3501 && targetm.calls.split_complex_arg (TREE_TYPE (parm)))
3503 rtx tmp, real, imag;
3504 scalar_mode inner = GET_MODE_INNER (DECL_MODE (parm));
3506 real = DECL_RTL (fnargs[i]);
3507 imag = DECL_RTL (fnargs[i + 1]);
3508 if (inner != GET_MODE (real))
3510 real = gen_lowpart_SUBREG (inner, real);
3511 imag = gen_lowpart_SUBREG (inner, imag);
3514 if (TREE_ADDRESSABLE (parm))
3516 rtx rmem, imem;
3517 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (parm));
3518 int align = STACK_SLOT_ALIGNMENT (TREE_TYPE (parm),
3519 DECL_MODE (parm),
3520 TYPE_ALIGN (TREE_TYPE (parm)));
3522 /* split_complex_arg put the real and imag parts in
3523 pseudos. Move them to memory. */
3524 tmp = assign_stack_local (DECL_MODE (parm), size, align);
3525 set_mem_attributes (tmp, parm, 1);
3526 rmem = adjust_address_nv (tmp, inner, 0);
3527 imem = adjust_address_nv (tmp, inner, GET_MODE_SIZE (inner));
3528 push_to_sequence2 (all->first_conversion_insn,
3529 all->last_conversion_insn);
3530 emit_move_insn (rmem, real);
3531 emit_move_insn (imem, imag);
3532 all->first_conversion_insn = get_insns ();
3533 all->last_conversion_insn = get_last_insn ();
3534 end_sequence ();
3536 else
3537 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
3538 set_parm_rtl (parm, tmp);
3540 real = DECL_INCOMING_RTL (fnargs[i]);
3541 imag = DECL_INCOMING_RTL (fnargs[i + 1]);
3542 if (inner != GET_MODE (real))
3544 real = gen_lowpart_SUBREG (inner, real);
3545 imag = gen_lowpart_SUBREG (inner, imag);
3547 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
3548 set_decl_incoming_rtl (parm, tmp, false);
3549 i++;
3554 /* Load bounds of PARM from bounds table. */
3555 static void
3556 assign_parm_load_bounds (struct assign_parm_data_one *data,
3557 tree parm,
3558 rtx entry,
3559 unsigned bound_no)
3561 bitmap_iterator bi;
3562 unsigned i, offs = 0;
3563 int bnd_no = -1;
3564 rtx slot = NULL, ptr = NULL;
3566 if (parm)
3568 bitmap slots;
3569 bitmap_obstack_initialize (NULL);
3570 slots = BITMAP_ALLOC (NULL);
3571 chkp_find_bound_slots (TREE_TYPE (parm), slots);
3572 EXECUTE_IF_SET_IN_BITMAP (slots, 0, i, bi)
3574 if (bound_no)
3575 bound_no--;
3576 else
3578 bnd_no = i;
3579 break;
3582 BITMAP_FREE (slots);
3583 bitmap_obstack_release (NULL);
3586 /* We may have bounds not associated with any pointer. */
3587 if (bnd_no != -1)
3588 offs = bnd_no * POINTER_SIZE / BITS_PER_UNIT;
3590 /* Find associated pointer. */
3591 if (bnd_no == -1)
3593 /* If bounds are not associated with any bounds,
3594 then it is passed in a register or special slot. */
3595 gcc_assert (data->entry_parm);
3596 ptr = const0_rtx;
3598 else if (MEM_P (entry))
3599 slot = adjust_address (entry, Pmode, offs);
3600 else if (REG_P (entry))
3601 ptr = gen_rtx_REG (Pmode, REGNO (entry) + bnd_no);
3602 else if (GET_CODE (entry) == PARALLEL)
3603 ptr = chkp_get_value_with_offs (entry, GEN_INT (offs));
3604 else
3605 gcc_unreachable ();
3606 data->entry_parm = targetm.calls.load_bounds_for_arg (slot, ptr,
3607 data->entry_parm);
3610 /* Assign RTL expressions to the function's bounds parameters BNDARGS. */
3612 static void
3613 assign_bounds (vec<bounds_parm_data> &bndargs,
3614 struct assign_parm_data_all &all,
3615 bool assign_regs, bool assign_special,
3616 bool assign_bt)
3618 unsigned i, pass;
3619 bounds_parm_data *pbdata;
3621 if (!bndargs.exists ())
3622 return;
3624 /* We make few passes to store input bounds. Firstly handle bounds
3625 passed in registers. After that we load bounds passed in special
3626 slots. Finally we load bounds from Bounds Table. */
3627 for (pass = 0; pass < 3; pass++)
3628 FOR_EACH_VEC_ELT (bndargs, i, pbdata)
3630 /* Pass 0 => regs only. */
3631 if (pass == 0
3632 && (!assign_regs
3633 ||(!pbdata->parm_data.entry_parm
3634 || GET_CODE (pbdata->parm_data.entry_parm) != REG)))
3635 continue;
3636 /* Pass 1 => slots only. */
3637 else if (pass == 1
3638 && (!assign_special
3639 || (!pbdata->parm_data.entry_parm
3640 || GET_CODE (pbdata->parm_data.entry_parm) == REG)))
3641 continue;
3642 /* Pass 2 => BT only. */
3643 else if (pass == 2
3644 && (!assign_bt
3645 || pbdata->parm_data.entry_parm))
3646 continue;
3648 if (!pbdata->parm_data.entry_parm
3649 || GET_CODE (pbdata->parm_data.entry_parm) != REG)
3650 assign_parm_load_bounds (&pbdata->parm_data, pbdata->ptr_parm,
3651 pbdata->ptr_entry, pbdata->bound_no);
3653 set_decl_incoming_rtl (pbdata->bounds_parm,
3654 pbdata->parm_data.entry_parm, false);
3656 if (assign_parm_setup_block_p (&pbdata->parm_data))
3657 assign_parm_setup_block (&all, pbdata->bounds_parm,
3658 &pbdata->parm_data);
3659 else if (pbdata->parm_data.passed_pointer
3660 || use_register_for_decl (pbdata->bounds_parm))
3661 assign_parm_setup_reg (&all, pbdata->bounds_parm,
3662 &pbdata->parm_data);
3663 else
3664 assign_parm_setup_stack (&all, pbdata->bounds_parm,
3665 &pbdata->parm_data);
3669 /* Assign RTL expressions to the function's parameters. This may involve
3670 copying them into registers and using those registers as the DECL_RTL. */
3672 static void
3673 assign_parms (tree fndecl)
3675 struct assign_parm_data_all all;
3676 tree parm;
3677 vec<tree> fnargs;
3678 unsigned i, bound_no = 0;
3679 tree last_arg = NULL;
3680 rtx last_arg_entry = NULL;
3681 vec<bounds_parm_data> bndargs = vNULL;
3682 bounds_parm_data bdata;
3684 crtl->args.internal_arg_pointer
3685 = targetm.calls.internal_arg_pointer ();
3687 assign_parms_initialize_all (&all);
3688 fnargs = assign_parms_augmented_arg_list (&all);
3690 FOR_EACH_VEC_ELT (fnargs, i, parm)
3692 struct assign_parm_data_one data;
3694 /* Extract the type of PARM; adjust it according to ABI. */
3695 assign_parm_find_data_types (&all, parm, &data);
3697 /* Early out for errors and void parameters. */
3698 if (data.passed_mode == VOIDmode)
3700 SET_DECL_RTL (parm, const0_rtx);
3701 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
3702 continue;
3705 /* Estimate stack alignment from parameter alignment. */
3706 if (SUPPORTS_STACK_ALIGNMENT)
3708 unsigned int align
3709 = targetm.calls.function_arg_boundary (data.promoted_mode,
3710 data.passed_type);
3711 align = MINIMUM_ALIGNMENT (data.passed_type, data.promoted_mode,
3712 align);
3713 if (TYPE_ALIGN (data.nominal_type) > align)
3714 align = MINIMUM_ALIGNMENT (data.nominal_type,
3715 TYPE_MODE (data.nominal_type),
3716 TYPE_ALIGN (data.nominal_type));
3717 if (crtl->stack_alignment_estimated < align)
3719 gcc_assert (!crtl->stack_realign_processed);
3720 crtl->stack_alignment_estimated = align;
3724 /* Find out where the parameter arrives in this function. */
3725 assign_parm_find_entry_rtl (&all, &data);
3727 /* Find out where stack space for this parameter might be. */
3728 if (assign_parm_is_stack_parm (&all, &data))
3730 assign_parm_find_stack_rtl (parm, &data);
3731 assign_parm_adjust_entry_rtl (&data);
3733 if (!POINTER_BOUNDS_TYPE_P (data.passed_type))
3735 /* Remember where last non bounds arg was passed in case
3736 we have to load associated bounds for it from Bounds
3737 Table. */
3738 last_arg = parm;
3739 last_arg_entry = data.entry_parm;
3740 bound_no = 0;
3742 /* Record permanently how this parm was passed. */
3743 if (data.passed_pointer)
3745 rtx incoming_rtl
3746 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data.passed_type)),
3747 data.entry_parm);
3748 set_decl_incoming_rtl (parm, incoming_rtl, true);
3750 else
3751 set_decl_incoming_rtl (parm, data.entry_parm, false);
3753 assign_parm_adjust_stack_rtl (&data);
3755 /* Bounds should be loaded in the particular order to
3756 have registers allocated correctly. Collect info about
3757 input bounds and load them later. */
3758 if (POINTER_BOUNDS_TYPE_P (data.passed_type))
3760 /* Expect bounds in instrumented functions only. */
3761 gcc_assert (chkp_function_instrumented_p (fndecl));
3763 bdata.parm_data = data;
3764 bdata.bounds_parm = parm;
3765 bdata.ptr_parm = last_arg;
3766 bdata.ptr_entry = last_arg_entry;
3767 bdata.bound_no = bound_no;
3768 bndargs.safe_push (bdata);
3770 else
3772 if (assign_parm_setup_block_p (&data))
3773 assign_parm_setup_block (&all, parm, &data);
3774 else if (data.passed_pointer || use_register_for_decl (parm))
3775 assign_parm_setup_reg (&all, parm, &data);
3776 else
3777 assign_parm_setup_stack (&all, parm, &data);
3780 if (cfun->stdarg && !DECL_CHAIN (parm))
3782 int pretend_bytes = 0;
3784 assign_parms_setup_varargs (&all, &data, false);
3786 if (chkp_function_instrumented_p (fndecl))
3788 /* We expect this is the last parm. Otherwise it is wrong
3789 to assign bounds right now. */
3790 gcc_assert (i == (fnargs.length () - 1));
3791 assign_bounds (bndargs, all, true, false, false);
3792 targetm.calls.setup_incoming_vararg_bounds (all.args_so_far,
3793 data.promoted_mode,
3794 data.passed_type,
3795 &pretend_bytes,
3796 false);
3797 assign_bounds (bndargs, all, false, true, true);
3798 bndargs.release ();
3802 /* Update info on where next arg arrives in registers. */
3803 targetm.calls.function_arg_advance (all.args_so_far, data.promoted_mode,
3804 data.passed_type, data.named_arg);
3806 if (POINTER_BOUNDS_TYPE_P (data.passed_type))
3807 bound_no++;
3810 assign_bounds (bndargs, all, true, true, true);
3811 bndargs.release ();
3813 if (targetm.calls.split_complex_arg)
3814 assign_parms_unsplit_complex (&all, fnargs);
3816 fnargs.release ();
3818 /* Output all parameter conversion instructions (possibly including calls)
3819 now that all parameters have been copied out of hard registers. */
3820 emit_insn (all.first_conversion_insn);
3822 /* Estimate reload stack alignment from scalar return mode. */
3823 if (SUPPORTS_STACK_ALIGNMENT)
3825 if (DECL_RESULT (fndecl))
3827 tree type = TREE_TYPE (DECL_RESULT (fndecl));
3828 machine_mode mode = TYPE_MODE (type);
3830 if (mode != BLKmode
3831 && mode != VOIDmode
3832 && !AGGREGATE_TYPE_P (type))
3834 unsigned int align = GET_MODE_ALIGNMENT (mode);
3835 if (crtl->stack_alignment_estimated < align)
3837 gcc_assert (!crtl->stack_realign_processed);
3838 crtl->stack_alignment_estimated = align;
3844 /* If we are receiving a struct value address as the first argument, set up
3845 the RTL for the function result. As this might require code to convert
3846 the transmitted address to Pmode, we do this here to ensure that possible
3847 preliminary conversions of the address have been emitted already. */
3848 if (all.function_result_decl)
3850 tree result = DECL_RESULT (current_function_decl);
3851 rtx addr = DECL_RTL (all.function_result_decl);
3852 rtx x;
3854 if (DECL_BY_REFERENCE (result))
3856 SET_DECL_VALUE_EXPR (result, all.function_result_decl);
3857 x = addr;
3859 else
3861 SET_DECL_VALUE_EXPR (result,
3862 build1 (INDIRECT_REF, TREE_TYPE (result),
3863 all.function_result_decl));
3864 addr = convert_memory_address (Pmode, addr);
3865 x = gen_rtx_MEM (DECL_MODE (result), addr);
3866 set_mem_attributes (x, result, 1);
3869 DECL_HAS_VALUE_EXPR_P (result) = 1;
3871 set_parm_rtl (result, x);
3874 /* We have aligned all the args, so add space for the pretend args. */
3875 crtl->args.pretend_args_size = all.pretend_args_size;
3876 all.stack_args_size.constant += all.extra_pretend_bytes;
3877 crtl->args.size = all.stack_args_size.constant;
3879 /* Adjust function incoming argument size for alignment and
3880 minimum length. */
3882 crtl->args.size = MAX (crtl->args.size, all.reg_parm_stack_space);
3883 crtl->args.size = CEIL_ROUND (crtl->args.size,
3884 PARM_BOUNDARY / BITS_PER_UNIT);
3886 if (ARGS_GROW_DOWNWARD)
3888 crtl->args.arg_offset_rtx
3889 = (all.stack_args_size.var == 0 ? GEN_INT (-all.stack_args_size.constant)
3890 : expand_expr (size_diffop (all.stack_args_size.var,
3891 size_int (-all.stack_args_size.constant)),
3892 NULL_RTX, VOIDmode, EXPAND_NORMAL));
3894 else
3895 crtl->args.arg_offset_rtx = ARGS_SIZE_RTX (all.stack_args_size);
3897 /* See how many bytes, if any, of its args a function should try to pop
3898 on return. */
3900 crtl->args.pops_args = targetm.calls.return_pops_args (fndecl,
3901 TREE_TYPE (fndecl),
3902 crtl->args.size);
3904 /* For stdarg.h function, save info about
3905 regs and stack space used by the named args. */
3907 crtl->args.info = all.args_so_far_v;
3909 /* Set the rtx used for the function return value. Put this in its
3910 own variable so any optimizers that need this information don't have
3911 to include tree.h. Do this here so it gets done when an inlined
3912 function gets output. */
3914 crtl->return_rtx
3915 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
3916 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
3918 /* If scalar return value was computed in a pseudo-reg, or was a named
3919 return value that got dumped to the stack, copy that to the hard
3920 return register. */
3921 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
3923 tree decl_result = DECL_RESULT (fndecl);
3924 rtx decl_rtl = DECL_RTL (decl_result);
3926 if (REG_P (decl_rtl)
3927 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
3928 : DECL_REGISTER (decl_result))
3930 rtx real_decl_rtl;
3932 real_decl_rtl = targetm.calls.function_value (TREE_TYPE (decl_result),
3933 fndecl, true);
3934 if (chkp_function_instrumented_p (fndecl))
3935 crtl->return_bnd
3936 = targetm.calls.chkp_function_value_bounds (TREE_TYPE (decl_result),
3937 fndecl, true);
3938 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
3939 /* The delay slot scheduler assumes that crtl->return_rtx
3940 holds the hard register containing the return value, not a
3941 temporary pseudo. */
3942 crtl->return_rtx = real_decl_rtl;
3947 /* A subroutine of gimplify_parameters, invoked via walk_tree.
3948 For all seen types, gimplify their sizes. */
3950 static tree
3951 gimplify_parm_type (tree *tp, int *walk_subtrees, void *data)
3953 tree t = *tp;
3955 *walk_subtrees = 0;
3956 if (TYPE_P (t))
3958 if (POINTER_TYPE_P (t))
3959 *walk_subtrees = 1;
3960 else if (TYPE_SIZE (t) && !TREE_CONSTANT (TYPE_SIZE (t))
3961 && !TYPE_SIZES_GIMPLIFIED (t))
3963 gimplify_type_sizes (t, (gimple_seq *) data);
3964 *walk_subtrees = 1;
3968 return NULL;
3971 /* Gimplify the parameter list for current_function_decl. This involves
3972 evaluating SAVE_EXPRs of variable sized parameters and generating code
3973 to implement callee-copies reference parameters. Returns a sequence of
3974 statements to add to the beginning of the function. */
3976 gimple_seq
3977 gimplify_parameters (void)
3979 struct assign_parm_data_all all;
3980 tree parm;
3981 gimple_seq stmts = NULL;
3982 vec<tree> fnargs;
3983 unsigned i;
3985 assign_parms_initialize_all (&all);
3986 fnargs = assign_parms_augmented_arg_list (&all);
3988 FOR_EACH_VEC_ELT (fnargs, i, parm)
3990 struct assign_parm_data_one data;
3992 /* Extract the type of PARM; adjust it according to ABI. */
3993 assign_parm_find_data_types (&all, parm, &data);
3995 /* Early out for errors and void parameters. */
3996 if (data.passed_mode == VOIDmode || DECL_SIZE (parm) == NULL)
3997 continue;
3999 /* Update info on where next arg arrives in registers. */
4000 targetm.calls.function_arg_advance (all.args_so_far, data.promoted_mode,
4001 data.passed_type, data.named_arg);
4003 /* ??? Once upon a time variable_size stuffed parameter list
4004 SAVE_EXPRs (amongst others) onto a pending sizes list. This
4005 turned out to be less than manageable in the gimple world.
4006 Now we have to hunt them down ourselves. */
4007 walk_tree_without_duplicates (&data.passed_type,
4008 gimplify_parm_type, &stmts);
4010 if (TREE_CODE (DECL_SIZE_UNIT (parm)) != INTEGER_CST)
4012 gimplify_one_sizepos (&DECL_SIZE (parm), &stmts);
4013 gimplify_one_sizepos (&DECL_SIZE_UNIT (parm), &stmts);
4016 if (data.passed_pointer)
4018 tree type = TREE_TYPE (data.passed_type);
4019 if (reference_callee_copied (&all.args_so_far_v, TYPE_MODE (type),
4020 type, data.named_arg))
4022 tree local, t;
4024 /* For constant-sized objects, this is trivial; for
4025 variable-sized objects, we have to play games. */
4026 if (TREE_CODE (DECL_SIZE_UNIT (parm)) == INTEGER_CST
4027 && !(flag_stack_check == GENERIC_STACK_CHECK
4028 && compare_tree_int (DECL_SIZE_UNIT (parm),
4029 STACK_CHECK_MAX_VAR_SIZE) > 0))
4031 local = create_tmp_var (type, get_name (parm));
4032 DECL_IGNORED_P (local) = 0;
4033 /* If PARM was addressable, move that flag over
4034 to the local copy, as its address will be taken,
4035 not the PARMs. Keep the parms address taken
4036 as we'll query that flag during gimplification. */
4037 if (TREE_ADDRESSABLE (parm))
4038 TREE_ADDRESSABLE (local) = 1;
4039 else if (TREE_CODE (type) == COMPLEX_TYPE
4040 || TREE_CODE (type) == VECTOR_TYPE)
4041 DECL_GIMPLE_REG_P (local) = 1;
4043 else
4045 tree ptr_type, addr;
4047 ptr_type = build_pointer_type (type);
4048 addr = create_tmp_reg (ptr_type, get_name (parm));
4049 DECL_IGNORED_P (addr) = 0;
4050 local = build_fold_indirect_ref (addr);
4052 t = builtin_decl_explicit (BUILT_IN_ALLOCA_WITH_ALIGN);
4053 t = build_call_expr (t, 2, DECL_SIZE_UNIT (parm),
4054 size_int (DECL_ALIGN (parm)));
4056 /* The call has been built for a variable-sized object. */
4057 CALL_ALLOCA_FOR_VAR_P (t) = 1;
4058 t = fold_convert (ptr_type, t);
4059 t = build2 (MODIFY_EXPR, TREE_TYPE (addr), addr, t);
4060 gimplify_and_add (t, &stmts);
4063 gimplify_assign (local, parm, &stmts);
4065 SET_DECL_VALUE_EXPR (parm, local);
4066 DECL_HAS_VALUE_EXPR_P (parm) = 1;
4071 fnargs.release ();
4073 return stmts;
4076 /* Compute the size and offset from the start of the stacked arguments for a
4077 parm passed in mode PASSED_MODE and with type TYPE.
4079 INITIAL_OFFSET_PTR points to the current offset into the stacked
4080 arguments.
4082 The starting offset and size for this parm are returned in
4083 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
4084 nonzero, the offset is that of stack slot, which is returned in
4085 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
4086 padding required from the initial offset ptr to the stack slot.
4088 IN_REGS is nonzero if the argument will be passed in registers. It will
4089 never be set if REG_PARM_STACK_SPACE is not defined.
4091 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
4092 for arguments which are passed in registers.
4094 FNDECL is the function in which the argument was defined.
4096 There are two types of rounding that are done. The first, controlled by
4097 TARGET_FUNCTION_ARG_BOUNDARY, forces the offset from the start of the
4098 argument list to be aligned to the specific boundary (in bits). This
4099 rounding affects the initial and starting offsets, but not the argument
4100 size.
4102 The second, controlled by TARGET_FUNCTION_ARG_PADDING and PARM_BOUNDARY,
4103 optionally rounds the size of the parm to PARM_BOUNDARY. The
4104 initial offset is not affected by this rounding, while the size always
4105 is and the starting offset may be. */
4107 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
4108 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
4109 callers pass in the total size of args so far as
4110 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
4112 void
4113 locate_and_pad_parm (machine_mode passed_mode, tree type, int in_regs,
4114 int reg_parm_stack_space, int partial,
4115 tree fndecl ATTRIBUTE_UNUSED,
4116 struct args_size *initial_offset_ptr,
4117 struct locate_and_pad_arg_data *locate)
4119 tree sizetree;
4120 pad_direction where_pad;
4121 unsigned int boundary, round_boundary;
4122 int part_size_in_regs;
4124 /* If we have found a stack parm before we reach the end of the
4125 area reserved for registers, skip that area. */
4126 if (! in_regs)
4128 if (reg_parm_stack_space > 0)
4130 if (initial_offset_ptr->var)
4132 initial_offset_ptr->var
4133 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
4134 ssize_int (reg_parm_stack_space));
4135 initial_offset_ptr->constant = 0;
4137 else if (initial_offset_ptr->constant < reg_parm_stack_space)
4138 initial_offset_ptr->constant = reg_parm_stack_space;
4142 part_size_in_regs = (reg_parm_stack_space == 0 ? partial : 0);
4144 sizetree
4145 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
4146 where_pad = targetm.calls.function_arg_padding (passed_mode, type);
4147 boundary = targetm.calls.function_arg_boundary (passed_mode, type);
4148 round_boundary = targetm.calls.function_arg_round_boundary (passed_mode,
4149 type);
4150 locate->where_pad = where_pad;
4152 /* Alignment can't exceed MAX_SUPPORTED_STACK_ALIGNMENT. */
4153 if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
4154 boundary = MAX_SUPPORTED_STACK_ALIGNMENT;
4156 locate->boundary = boundary;
4158 if (SUPPORTS_STACK_ALIGNMENT)
4160 /* stack_alignment_estimated can't change after stack has been
4161 realigned. */
4162 if (crtl->stack_alignment_estimated < boundary)
4164 if (!crtl->stack_realign_processed)
4165 crtl->stack_alignment_estimated = boundary;
4166 else
4168 /* If stack is realigned and stack alignment value
4169 hasn't been finalized, it is OK not to increase
4170 stack_alignment_estimated. The bigger alignment
4171 requirement is recorded in stack_alignment_needed
4172 below. */
4173 gcc_assert (!crtl->stack_realign_finalized
4174 && crtl->stack_realign_needed);
4179 /* Remember if the outgoing parameter requires extra alignment on the
4180 calling function side. */
4181 if (crtl->stack_alignment_needed < boundary)
4182 crtl->stack_alignment_needed = boundary;
4183 if (crtl->preferred_stack_boundary < boundary)
4184 crtl->preferred_stack_boundary = boundary;
4186 if (ARGS_GROW_DOWNWARD)
4188 locate->slot_offset.constant = -initial_offset_ptr->constant;
4189 if (initial_offset_ptr->var)
4190 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
4191 initial_offset_ptr->var);
4194 tree s2 = sizetree;
4195 if (where_pad != PAD_NONE
4196 && (!tree_fits_uhwi_p (sizetree)
4197 || (tree_to_uhwi (sizetree) * BITS_PER_UNIT) % round_boundary))
4198 s2 = round_up (s2, round_boundary / BITS_PER_UNIT);
4199 SUB_PARM_SIZE (locate->slot_offset, s2);
4202 locate->slot_offset.constant += part_size_in_regs;
4204 if (!in_regs || reg_parm_stack_space > 0)
4205 pad_to_arg_alignment (&locate->slot_offset, boundary,
4206 &locate->alignment_pad);
4208 locate->size.constant = (-initial_offset_ptr->constant
4209 - locate->slot_offset.constant);
4210 if (initial_offset_ptr->var)
4211 locate->size.var = size_binop (MINUS_EXPR,
4212 size_binop (MINUS_EXPR,
4213 ssize_int (0),
4214 initial_offset_ptr->var),
4215 locate->slot_offset.var);
4217 /* Pad_below needs the pre-rounded size to know how much to pad
4218 below. */
4219 locate->offset = locate->slot_offset;
4220 if (where_pad == PAD_DOWNWARD)
4221 pad_below (&locate->offset, passed_mode, sizetree);
4224 else
4226 if (!in_regs || reg_parm_stack_space > 0)
4227 pad_to_arg_alignment (initial_offset_ptr, boundary,
4228 &locate->alignment_pad);
4229 locate->slot_offset = *initial_offset_ptr;
4231 #ifdef PUSH_ROUNDING
4232 if (passed_mode != BLKmode)
4233 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
4234 #endif
4236 /* Pad_below needs the pre-rounded size to know how much to pad below
4237 so this must be done before rounding up. */
4238 locate->offset = locate->slot_offset;
4239 if (where_pad == PAD_DOWNWARD)
4240 pad_below (&locate->offset, passed_mode, sizetree);
4242 if (where_pad != PAD_NONE
4243 && (!tree_fits_uhwi_p (sizetree)
4244 || (tree_to_uhwi (sizetree) * BITS_PER_UNIT) % round_boundary))
4245 sizetree = round_up (sizetree, round_boundary / BITS_PER_UNIT);
4247 ADD_PARM_SIZE (locate->size, sizetree);
4249 locate->size.constant -= part_size_in_regs;
4252 locate->offset.constant
4253 += targetm.calls.function_arg_offset (passed_mode, type);
4256 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
4257 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
4259 static void
4260 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
4261 struct args_size *alignment_pad)
4263 tree save_var = NULL_TREE;
4264 HOST_WIDE_INT save_constant = 0;
4265 int boundary_in_bytes = boundary / BITS_PER_UNIT;
4266 HOST_WIDE_INT sp_offset = STACK_POINTER_OFFSET;
4268 #ifdef SPARC_STACK_BOUNDARY_HACK
4269 /* ??? The SPARC port may claim a STACK_BOUNDARY higher than
4270 the real alignment of %sp. However, when it does this, the
4271 alignment of %sp+STACK_POINTER_OFFSET is STACK_BOUNDARY. */
4272 if (SPARC_STACK_BOUNDARY_HACK)
4273 sp_offset = 0;
4274 #endif
4276 if (boundary > PARM_BOUNDARY)
4278 save_var = offset_ptr->var;
4279 save_constant = offset_ptr->constant;
4282 alignment_pad->var = NULL_TREE;
4283 alignment_pad->constant = 0;
4285 if (boundary > BITS_PER_UNIT)
4287 if (offset_ptr->var)
4289 tree sp_offset_tree = ssize_int (sp_offset);
4290 tree offset = size_binop (PLUS_EXPR,
4291 ARGS_SIZE_TREE (*offset_ptr),
4292 sp_offset_tree);
4293 tree rounded;
4294 if (ARGS_GROW_DOWNWARD)
4295 rounded = round_down (offset, boundary / BITS_PER_UNIT);
4296 else
4297 rounded = round_up (offset, boundary / BITS_PER_UNIT);
4299 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
4300 /* ARGS_SIZE_TREE includes constant term. */
4301 offset_ptr->constant = 0;
4302 if (boundary > PARM_BOUNDARY)
4303 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
4304 save_var);
4306 else
4308 offset_ptr->constant = -sp_offset +
4309 (ARGS_GROW_DOWNWARD
4310 ? FLOOR_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes)
4311 : CEIL_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes));
4313 if (boundary > PARM_BOUNDARY)
4314 alignment_pad->constant = offset_ptr->constant - save_constant;
4319 static void
4320 pad_below (struct args_size *offset_ptr, machine_mode passed_mode, tree sizetree)
4322 unsigned int align = PARM_BOUNDARY / BITS_PER_UNIT;
4323 if (passed_mode != BLKmode)
4324 offset_ptr->constant += -GET_MODE_SIZE (passed_mode) & (align - 1);
4325 else
4327 if (TREE_CODE (sizetree) != INTEGER_CST
4328 || (TREE_INT_CST_LOW (sizetree) & (align - 1)) != 0)
4330 /* Round the size up to multiple of PARM_BOUNDARY bits. */
4331 tree s2 = round_up (sizetree, align);
4332 /* Add it in. */
4333 ADD_PARM_SIZE (*offset_ptr, s2);
4334 SUB_PARM_SIZE (*offset_ptr, sizetree);
4340 /* True if register REGNO was alive at a place where `setjmp' was
4341 called and was set more than once or is an argument. Such regs may
4342 be clobbered by `longjmp'. */
4344 static bool
4345 regno_clobbered_at_setjmp (bitmap setjmp_crosses, int regno)
4347 /* There appear to be cases where some local vars never reach the
4348 backend but have bogus regnos. */
4349 if (regno >= max_reg_num ())
4350 return false;
4352 return ((REG_N_SETS (regno) > 1
4353 || REGNO_REG_SET_P (df_get_live_out (ENTRY_BLOCK_PTR_FOR_FN (cfun)),
4354 regno))
4355 && REGNO_REG_SET_P (setjmp_crosses, regno));
4358 /* Walk the tree of blocks describing the binding levels within a
4359 function and warn about variables the might be killed by setjmp or
4360 vfork. This is done after calling flow_analysis before register
4361 allocation since that will clobber the pseudo-regs to hard
4362 regs. */
4364 static void
4365 setjmp_vars_warning (bitmap setjmp_crosses, tree block)
4367 tree decl, sub;
4369 for (decl = BLOCK_VARS (block); decl; decl = DECL_CHAIN (decl))
4371 if (VAR_P (decl)
4372 && DECL_RTL_SET_P (decl)
4373 && REG_P (DECL_RTL (decl))
4374 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
4375 warning (OPT_Wclobbered, "variable %q+D might be clobbered by"
4376 " %<longjmp%> or %<vfork%>", decl);
4379 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = BLOCK_CHAIN (sub))
4380 setjmp_vars_warning (setjmp_crosses, sub);
4383 /* Do the appropriate part of setjmp_vars_warning
4384 but for arguments instead of local variables. */
4386 static void
4387 setjmp_args_warning (bitmap setjmp_crosses)
4389 tree decl;
4390 for (decl = DECL_ARGUMENTS (current_function_decl);
4391 decl; decl = DECL_CHAIN (decl))
4392 if (DECL_RTL (decl) != 0
4393 && REG_P (DECL_RTL (decl))
4394 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
4395 warning (OPT_Wclobbered,
4396 "argument %q+D might be clobbered by %<longjmp%> or %<vfork%>",
4397 decl);
4400 /* Generate warning messages for variables live across setjmp. */
4402 void
4403 generate_setjmp_warnings (void)
4405 bitmap setjmp_crosses = regstat_get_setjmp_crosses ();
4407 if (n_basic_blocks_for_fn (cfun) == NUM_FIXED_BLOCKS
4408 || bitmap_empty_p (setjmp_crosses))
4409 return;
4411 setjmp_vars_warning (setjmp_crosses, DECL_INITIAL (current_function_decl));
4412 setjmp_args_warning (setjmp_crosses);
4416 /* Reverse the order of elements in the fragment chain T of blocks,
4417 and return the new head of the chain (old last element).
4418 In addition to that clear BLOCK_SAME_RANGE flags when needed
4419 and adjust BLOCK_SUPERCONTEXT from the super fragment to
4420 its super fragment origin. */
4422 static tree
4423 block_fragments_nreverse (tree t)
4425 tree prev = 0, block, next, prev_super = 0;
4426 tree super = BLOCK_SUPERCONTEXT (t);
4427 if (BLOCK_FRAGMENT_ORIGIN (super))
4428 super = BLOCK_FRAGMENT_ORIGIN (super);
4429 for (block = t; block; block = next)
4431 next = BLOCK_FRAGMENT_CHAIN (block);
4432 BLOCK_FRAGMENT_CHAIN (block) = prev;
4433 if ((prev && !BLOCK_SAME_RANGE (prev))
4434 || (BLOCK_FRAGMENT_CHAIN (BLOCK_SUPERCONTEXT (block))
4435 != prev_super))
4436 BLOCK_SAME_RANGE (block) = 0;
4437 prev_super = BLOCK_SUPERCONTEXT (block);
4438 BLOCK_SUPERCONTEXT (block) = super;
4439 prev = block;
4441 t = BLOCK_FRAGMENT_ORIGIN (t);
4442 if (BLOCK_FRAGMENT_CHAIN (BLOCK_SUPERCONTEXT (t))
4443 != prev_super)
4444 BLOCK_SAME_RANGE (t) = 0;
4445 BLOCK_SUPERCONTEXT (t) = super;
4446 return prev;
4449 /* Reverse the order of elements in the chain T of blocks,
4450 and return the new head of the chain (old last element).
4451 Also do the same on subblocks and reverse the order of elements
4452 in BLOCK_FRAGMENT_CHAIN as well. */
4454 static tree
4455 blocks_nreverse_all (tree t)
4457 tree prev = 0, block, next;
4458 for (block = t; block; block = next)
4460 next = BLOCK_CHAIN (block);
4461 BLOCK_CHAIN (block) = prev;
4462 if (BLOCK_FRAGMENT_CHAIN (block)
4463 && BLOCK_FRAGMENT_ORIGIN (block) == NULL_TREE)
4465 BLOCK_FRAGMENT_CHAIN (block)
4466 = block_fragments_nreverse (BLOCK_FRAGMENT_CHAIN (block));
4467 if (!BLOCK_SAME_RANGE (BLOCK_FRAGMENT_CHAIN (block)))
4468 BLOCK_SAME_RANGE (block) = 0;
4470 BLOCK_SUBBLOCKS (block) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block));
4471 prev = block;
4473 return prev;
4477 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
4478 and create duplicate blocks. */
4479 /* ??? Need an option to either create block fragments or to create
4480 abstract origin duplicates of a source block. It really depends
4481 on what optimization has been performed. */
4483 void
4484 reorder_blocks (void)
4486 tree block = DECL_INITIAL (current_function_decl);
4488 if (block == NULL_TREE)
4489 return;
4491 auto_vec<tree, 10> block_stack;
4493 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
4494 clear_block_marks (block);
4496 /* Prune the old trees away, so that they don't get in the way. */
4497 BLOCK_SUBBLOCKS (block) = NULL_TREE;
4498 BLOCK_CHAIN (block) = NULL_TREE;
4500 /* Recreate the block tree from the note nesting. */
4501 reorder_blocks_1 (get_insns (), block, &block_stack);
4502 BLOCK_SUBBLOCKS (block) = blocks_nreverse_all (BLOCK_SUBBLOCKS (block));
4505 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
4507 void
4508 clear_block_marks (tree block)
4510 while (block)
4512 TREE_ASM_WRITTEN (block) = 0;
4513 clear_block_marks (BLOCK_SUBBLOCKS (block));
4514 block = BLOCK_CHAIN (block);
4518 static void
4519 reorder_blocks_1 (rtx_insn *insns, tree current_block,
4520 vec<tree> *p_block_stack)
4522 rtx_insn *insn;
4523 tree prev_beg = NULL_TREE, prev_end = NULL_TREE;
4525 for (insn = insns; insn; insn = NEXT_INSN (insn))
4527 if (NOTE_P (insn))
4529 if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_BEG)
4531 tree block = NOTE_BLOCK (insn);
4532 tree origin;
4534 gcc_assert (BLOCK_FRAGMENT_ORIGIN (block) == NULL_TREE);
4535 origin = block;
4537 if (prev_end)
4538 BLOCK_SAME_RANGE (prev_end) = 0;
4539 prev_end = NULL_TREE;
4541 /* If we have seen this block before, that means it now
4542 spans multiple address regions. Create a new fragment. */
4543 if (TREE_ASM_WRITTEN (block))
4545 tree new_block = copy_node (block);
4547 BLOCK_SAME_RANGE (new_block) = 0;
4548 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
4549 BLOCK_FRAGMENT_CHAIN (new_block)
4550 = BLOCK_FRAGMENT_CHAIN (origin);
4551 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
4553 NOTE_BLOCK (insn) = new_block;
4554 block = new_block;
4557 if (prev_beg == current_block && prev_beg)
4558 BLOCK_SAME_RANGE (block) = 1;
4560 prev_beg = origin;
4562 BLOCK_SUBBLOCKS (block) = 0;
4563 TREE_ASM_WRITTEN (block) = 1;
4564 /* When there's only one block for the entire function,
4565 current_block == block and we mustn't do this, it
4566 will cause infinite recursion. */
4567 if (block != current_block)
4569 tree super;
4570 if (block != origin)
4571 gcc_assert (BLOCK_SUPERCONTEXT (origin) == current_block
4572 || BLOCK_FRAGMENT_ORIGIN (BLOCK_SUPERCONTEXT
4573 (origin))
4574 == current_block);
4575 if (p_block_stack->is_empty ())
4576 super = current_block;
4577 else
4579 super = p_block_stack->last ();
4580 gcc_assert (super == current_block
4581 || BLOCK_FRAGMENT_ORIGIN (super)
4582 == current_block);
4584 BLOCK_SUPERCONTEXT (block) = super;
4585 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
4586 BLOCK_SUBBLOCKS (current_block) = block;
4587 current_block = origin;
4589 p_block_stack->safe_push (block);
4591 else if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_END)
4593 NOTE_BLOCK (insn) = p_block_stack->pop ();
4594 current_block = BLOCK_SUPERCONTEXT (current_block);
4595 if (BLOCK_FRAGMENT_ORIGIN (current_block))
4596 current_block = BLOCK_FRAGMENT_ORIGIN (current_block);
4597 prev_beg = NULL_TREE;
4598 prev_end = BLOCK_SAME_RANGE (NOTE_BLOCK (insn))
4599 ? NOTE_BLOCK (insn) : NULL_TREE;
4602 else
4604 prev_beg = NULL_TREE;
4605 if (prev_end)
4606 BLOCK_SAME_RANGE (prev_end) = 0;
4607 prev_end = NULL_TREE;
4612 /* Reverse the order of elements in the chain T of blocks,
4613 and return the new head of the chain (old last element). */
4615 tree
4616 blocks_nreverse (tree t)
4618 tree prev = 0, block, next;
4619 for (block = t; block; block = next)
4621 next = BLOCK_CHAIN (block);
4622 BLOCK_CHAIN (block) = prev;
4623 prev = block;
4625 return prev;
4628 /* Concatenate two chains of blocks (chained through BLOCK_CHAIN)
4629 by modifying the last node in chain 1 to point to chain 2. */
4631 tree
4632 block_chainon (tree op1, tree op2)
4634 tree t1;
4636 if (!op1)
4637 return op2;
4638 if (!op2)
4639 return op1;
4641 for (t1 = op1; BLOCK_CHAIN (t1); t1 = BLOCK_CHAIN (t1))
4642 continue;
4643 BLOCK_CHAIN (t1) = op2;
4645 #ifdef ENABLE_TREE_CHECKING
4647 tree t2;
4648 for (t2 = op2; t2; t2 = BLOCK_CHAIN (t2))
4649 gcc_assert (t2 != t1);
4651 #endif
4653 return op1;
4656 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
4657 non-NULL, list them all into VECTOR, in a depth-first preorder
4658 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
4659 blocks. */
4661 static int
4662 all_blocks (tree block, tree *vector)
4664 int n_blocks = 0;
4666 while (block)
4668 TREE_ASM_WRITTEN (block) = 0;
4670 /* Record this block. */
4671 if (vector)
4672 vector[n_blocks] = block;
4674 ++n_blocks;
4676 /* Record the subblocks, and their subblocks... */
4677 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
4678 vector ? vector + n_blocks : 0);
4679 block = BLOCK_CHAIN (block);
4682 return n_blocks;
4685 /* Return a vector containing all the blocks rooted at BLOCK. The
4686 number of elements in the vector is stored in N_BLOCKS_P. The
4687 vector is dynamically allocated; it is the caller's responsibility
4688 to call `free' on the pointer returned. */
4690 static tree *
4691 get_block_vector (tree block, int *n_blocks_p)
4693 tree *block_vector;
4695 *n_blocks_p = all_blocks (block, NULL);
4696 block_vector = XNEWVEC (tree, *n_blocks_p);
4697 all_blocks (block, block_vector);
4699 return block_vector;
4702 static GTY(()) int next_block_index = 2;
4704 /* Set BLOCK_NUMBER for all the blocks in FN. */
4706 void
4707 number_blocks (tree fn)
4709 int i;
4710 int n_blocks;
4711 tree *block_vector;
4713 /* For SDB and XCOFF debugging output, we start numbering the blocks
4714 from 1 within each function, rather than keeping a running
4715 count. */
4716 #if SDB_DEBUGGING_INFO || defined (XCOFF_DEBUGGING_INFO)
4717 if (write_symbols == SDB_DEBUG || write_symbols == XCOFF_DEBUG)
4718 next_block_index = 1;
4719 #endif
4721 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
4723 /* The top-level BLOCK isn't numbered at all. */
4724 for (i = 1; i < n_blocks; ++i)
4725 /* We number the blocks from two. */
4726 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
4728 free (block_vector);
4730 return;
4733 /* If VAR is present in a subblock of BLOCK, return the subblock. */
4735 DEBUG_FUNCTION tree
4736 debug_find_var_in_block_tree (tree var, tree block)
4738 tree t;
4740 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
4741 if (t == var)
4742 return block;
4744 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
4746 tree ret = debug_find_var_in_block_tree (var, t);
4747 if (ret)
4748 return ret;
4751 return NULL_TREE;
4754 /* Keep track of whether we're in a dummy function context. If we are,
4755 we don't want to invoke the set_current_function hook, because we'll
4756 get into trouble if the hook calls target_reinit () recursively or
4757 when the initial initialization is not yet complete. */
4759 static bool in_dummy_function;
4761 /* Invoke the target hook when setting cfun. Update the optimization options
4762 if the function uses different options than the default. */
4764 static void
4765 invoke_set_current_function_hook (tree fndecl)
4767 if (!in_dummy_function)
4769 tree opts = ((fndecl)
4770 ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (fndecl)
4771 : optimization_default_node);
4773 if (!opts)
4774 opts = optimization_default_node;
4776 /* Change optimization options if needed. */
4777 if (optimization_current_node != opts)
4779 optimization_current_node = opts;
4780 cl_optimization_restore (&global_options, TREE_OPTIMIZATION (opts));
4783 targetm.set_current_function (fndecl);
4784 this_fn_optabs = this_target_optabs;
4786 if (opts != optimization_default_node)
4788 init_tree_optimization_optabs (opts);
4789 if (TREE_OPTIMIZATION_OPTABS (opts))
4790 this_fn_optabs = (struct target_optabs *)
4791 TREE_OPTIMIZATION_OPTABS (opts);
4796 /* cfun should never be set directly; use this function. */
4798 void
4799 set_cfun (struct function *new_cfun, bool force)
4801 if (cfun != new_cfun || force)
4803 cfun = new_cfun;
4804 invoke_set_current_function_hook (new_cfun ? new_cfun->decl : NULL_TREE);
4805 redirect_edge_var_map_empty ();
4809 /* Initialized with NOGC, making this poisonous to the garbage collector. */
4811 static vec<function *> cfun_stack;
4813 /* Push the current cfun onto the stack, and set cfun to new_cfun. Also set
4814 current_function_decl accordingly. */
4816 void
4817 push_cfun (struct function *new_cfun)
4819 gcc_assert ((!cfun && !current_function_decl)
4820 || (cfun && current_function_decl == cfun->decl));
4821 cfun_stack.safe_push (cfun);
4822 current_function_decl = new_cfun ? new_cfun->decl : NULL_TREE;
4823 set_cfun (new_cfun);
4826 /* Pop cfun from the stack. Also set current_function_decl accordingly. */
4828 void
4829 pop_cfun (void)
4831 struct function *new_cfun = cfun_stack.pop ();
4832 /* When in_dummy_function, we do have a cfun but current_function_decl is
4833 NULL. We also allow pushing NULL cfun and subsequently changing
4834 current_function_decl to something else and have both restored by
4835 pop_cfun. */
4836 gcc_checking_assert (in_dummy_function
4837 || !cfun
4838 || current_function_decl == cfun->decl);
4839 set_cfun (new_cfun);
4840 current_function_decl = new_cfun ? new_cfun->decl : NULL_TREE;
4843 /* Return value of funcdef and increase it. */
4845 get_next_funcdef_no (void)
4847 return funcdef_no++;
4850 /* Return value of funcdef. */
4852 get_last_funcdef_no (void)
4854 return funcdef_no;
4857 /* Allocate a function structure for FNDECL and set its contents
4858 to the defaults. Set cfun to the newly-allocated object.
4859 Some of the helper functions invoked during initialization assume
4860 that cfun has already been set. Therefore, assign the new object
4861 directly into cfun and invoke the back end hook explicitly at the
4862 very end, rather than initializing a temporary and calling set_cfun
4863 on it.
4865 ABSTRACT_P is true if this is a function that will never be seen by
4866 the middle-end. Such functions are front-end concepts (like C++
4867 function templates) that do not correspond directly to functions
4868 placed in object files. */
4870 void
4871 allocate_struct_function (tree fndecl, bool abstract_p)
4873 tree fntype = fndecl ? TREE_TYPE (fndecl) : NULL_TREE;
4875 cfun = ggc_cleared_alloc<function> ();
4877 init_eh_for_function ();
4879 if (init_machine_status)
4880 cfun->machine = (*init_machine_status) ();
4882 #ifdef OVERRIDE_ABI_FORMAT
4883 OVERRIDE_ABI_FORMAT (fndecl);
4884 #endif
4886 if (fndecl != NULL_TREE)
4888 DECL_STRUCT_FUNCTION (fndecl) = cfun;
4889 cfun->decl = fndecl;
4890 current_function_funcdef_no = get_next_funcdef_no ();
4893 invoke_set_current_function_hook (fndecl);
4895 if (fndecl != NULL_TREE)
4897 tree result = DECL_RESULT (fndecl);
4899 if (!abstract_p)
4901 /* Now that we have activated any function-specific attributes
4902 that might affect layout, particularly vector modes, relayout
4903 each of the parameters and the result. */
4904 relayout_decl (result);
4905 for (tree parm = DECL_ARGUMENTS (fndecl); parm;
4906 parm = DECL_CHAIN (parm))
4907 relayout_decl (parm);
4909 /* Similarly relayout the function decl. */
4910 targetm.target_option.relayout_function (fndecl);
4913 if (!abstract_p && aggregate_value_p (result, fndecl))
4915 #ifdef PCC_STATIC_STRUCT_RETURN
4916 cfun->returns_pcc_struct = 1;
4917 #endif
4918 cfun->returns_struct = 1;
4921 cfun->stdarg = stdarg_p (fntype);
4923 /* Assume all registers in stdarg functions need to be saved. */
4924 cfun->va_list_gpr_size = VA_LIST_MAX_GPR_SIZE;
4925 cfun->va_list_fpr_size = VA_LIST_MAX_FPR_SIZE;
4927 /* ??? This could be set on a per-function basis by the front-end
4928 but is this worth the hassle? */
4929 cfun->can_throw_non_call_exceptions = flag_non_call_exceptions;
4930 cfun->can_delete_dead_exceptions = flag_delete_dead_exceptions;
4932 if (!profile_flag && !flag_instrument_function_entry_exit)
4933 DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (fndecl) = 1;
4937 /* This is like allocate_struct_function, but pushes a new cfun for FNDECL
4938 instead of just setting it. */
4940 void
4941 push_struct_function (tree fndecl)
4943 /* When in_dummy_function we might be in the middle of a pop_cfun and
4944 current_function_decl and cfun may not match. */
4945 gcc_assert (in_dummy_function
4946 || (!cfun && !current_function_decl)
4947 || (cfun && current_function_decl == cfun->decl));
4948 cfun_stack.safe_push (cfun);
4949 current_function_decl = fndecl;
4950 allocate_struct_function (fndecl, false);
4953 /* Reset crtl and other non-struct-function variables to defaults as
4954 appropriate for emitting rtl at the start of a function. */
4956 static void
4957 prepare_function_start (void)
4959 gcc_assert (!get_last_insn ());
4960 init_temp_slots ();
4961 init_emit ();
4962 init_varasm_status ();
4963 init_expr ();
4964 default_rtl_profile ();
4966 if (flag_stack_usage_info)
4968 cfun->su = ggc_cleared_alloc<stack_usage> ();
4969 cfun->su->static_stack_size = -1;
4972 cse_not_expected = ! optimize;
4974 /* Caller save not needed yet. */
4975 caller_save_needed = 0;
4977 /* We haven't done register allocation yet. */
4978 reg_renumber = 0;
4980 /* Indicate that we have not instantiated virtual registers yet. */
4981 virtuals_instantiated = 0;
4983 /* Indicate that we want CONCATs now. */
4984 generating_concat_p = 1;
4986 /* Indicate we have no need of a frame pointer yet. */
4987 frame_pointer_needed = 0;
4990 void
4991 push_dummy_function (bool with_decl)
4993 tree fn_decl, fn_type, fn_result_decl;
4995 gcc_assert (!in_dummy_function);
4996 in_dummy_function = true;
4998 if (with_decl)
5000 fn_type = build_function_type_list (void_type_node, NULL_TREE);
5001 fn_decl = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL, NULL_TREE,
5002 fn_type);
5003 fn_result_decl = build_decl (UNKNOWN_LOCATION, RESULT_DECL,
5004 NULL_TREE, void_type_node);
5005 DECL_RESULT (fn_decl) = fn_result_decl;
5007 else
5008 fn_decl = NULL_TREE;
5010 push_struct_function (fn_decl);
5013 /* Initialize the rtl expansion mechanism so that we can do simple things
5014 like generate sequences. This is used to provide a context during global
5015 initialization of some passes. You must call expand_dummy_function_end
5016 to exit this context. */
5018 void
5019 init_dummy_function_start (void)
5021 push_dummy_function (false);
5022 prepare_function_start ();
5025 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
5026 and initialize static variables for generating RTL for the statements
5027 of the function. */
5029 void
5030 init_function_start (tree subr)
5032 /* Initialize backend, if needed. */
5033 initialize_rtl ();
5035 prepare_function_start ();
5036 decide_function_section (subr);
5038 /* Warn if this value is an aggregate type,
5039 regardless of which calling convention we are using for it. */
5040 if (AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
5041 warning (OPT_Waggregate_return, "function returns an aggregate");
5044 /* Expand code to verify the stack_protect_guard. This is invoked at
5045 the end of a function to be protected. */
5047 void
5048 stack_protect_epilogue (void)
5050 tree guard_decl = targetm.stack_protect_guard ();
5051 rtx_code_label *label = gen_label_rtx ();
5052 rtx x, y;
5053 rtx_insn *seq;
5055 x = expand_normal (crtl->stack_protect_guard);
5056 if (guard_decl)
5057 y = expand_normal (guard_decl);
5058 else
5059 y = const0_rtx;
5061 /* Allow the target to compare Y with X without leaking either into
5062 a register. */
5063 if (targetm.have_stack_protect_test ()
5064 && ((seq = targetm.gen_stack_protect_test (x, y, label)) != NULL_RTX))
5065 emit_insn (seq);
5066 else
5067 emit_cmp_and_jump_insns (x, y, EQ, NULL_RTX, ptr_mode, 1, label);
5069 /* The noreturn predictor has been moved to the tree level. The rtl-level
5070 predictors estimate this branch about 20%, which isn't enough to get
5071 things moved out of line. Since this is the only extant case of adding
5072 a noreturn function at the rtl level, it doesn't seem worth doing ought
5073 except adding the prediction by hand. */
5074 rtx_insn *tmp = get_last_insn ();
5075 if (JUMP_P (tmp))
5076 predict_insn_def (tmp, PRED_NORETURN, TAKEN);
5078 expand_call (targetm.stack_protect_fail (), NULL_RTX, /*ignore=*/true);
5079 free_temp_slots ();
5080 emit_label (label);
5083 /* Start the RTL for a new function, and set variables used for
5084 emitting RTL.
5085 SUBR is the FUNCTION_DECL node.
5086 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
5087 the function's parameters, which must be run at any return statement. */
5089 void
5090 expand_function_start (tree subr)
5092 /* Make sure volatile mem refs aren't considered
5093 valid operands of arithmetic insns. */
5094 init_recog_no_volatile ();
5096 crtl->profile
5097 = (profile_flag
5098 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
5100 crtl->limit_stack
5101 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
5103 /* Make the label for return statements to jump to. Do not special
5104 case machines with special return instructions -- they will be
5105 handled later during jump, ifcvt, or epilogue creation. */
5106 return_label = gen_label_rtx ();
5108 /* Initialize rtx used to return the value. */
5109 /* Do this before assign_parms so that we copy the struct value address
5110 before any library calls that assign parms might generate. */
5112 /* Decide whether to return the value in memory or in a register. */
5113 tree res = DECL_RESULT (subr);
5114 if (aggregate_value_p (res, subr))
5116 /* Returning something that won't go in a register. */
5117 rtx value_address = 0;
5119 #ifdef PCC_STATIC_STRUCT_RETURN
5120 if (cfun->returns_pcc_struct)
5122 int size = int_size_in_bytes (TREE_TYPE (res));
5123 value_address = assemble_static_space (size);
5125 else
5126 #endif
5128 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 2);
5129 /* Expect to be passed the address of a place to store the value.
5130 If it is passed as an argument, assign_parms will take care of
5131 it. */
5132 if (sv)
5134 value_address = gen_reg_rtx (Pmode);
5135 emit_move_insn (value_address, sv);
5138 if (value_address)
5140 rtx x = value_address;
5141 if (!DECL_BY_REFERENCE (res))
5143 x = gen_rtx_MEM (DECL_MODE (res), x);
5144 set_mem_attributes (x, res, 1);
5146 set_parm_rtl (res, x);
5149 else if (DECL_MODE (res) == VOIDmode)
5150 /* If return mode is void, this decl rtl should not be used. */
5151 set_parm_rtl (res, NULL_RTX);
5152 else
5154 /* Compute the return values into a pseudo reg, which we will copy
5155 into the true return register after the cleanups are done. */
5156 tree return_type = TREE_TYPE (res);
5158 /* If we may coalesce this result, make sure it has the expected mode
5159 in case it was promoted. But we need not bother about BLKmode. */
5160 machine_mode promoted_mode
5161 = flag_tree_coalesce_vars && is_gimple_reg (res)
5162 ? promote_ssa_mode (ssa_default_def (cfun, res), NULL)
5163 : BLKmode;
5165 if (promoted_mode != BLKmode)
5166 set_parm_rtl (res, gen_reg_rtx (promoted_mode));
5167 else if (TYPE_MODE (return_type) != BLKmode
5168 && targetm.calls.return_in_msb (return_type))
5169 /* expand_function_end will insert the appropriate padding in
5170 this case. Use the return value's natural (unpadded) mode
5171 within the function proper. */
5172 set_parm_rtl (res, gen_reg_rtx (TYPE_MODE (return_type)));
5173 else
5175 /* In order to figure out what mode to use for the pseudo, we
5176 figure out what the mode of the eventual return register will
5177 actually be, and use that. */
5178 rtx hard_reg = hard_function_value (return_type, subr, 0, 1);
5180 /* Structures that are returned in registers are not
5181 aggregate_value_p, so we may see a PARALLEL or a REG. */
5182 if (REG_P (hard_reg))
5183 set_parm_rtl (res, gen_reg_rtx (GET_MODE (hard_reg)));
5184 else
5186 gcc_assert (GET_CODE (hard_reg) == PARALLEL);
5187 set_parm_rtl (res, gen_group_rtx (hard_reg));
5191 /* Set DECL_REGISTER flag so that expand_function_end will copy the
5192 result to the real return register(s). */
5193 DECL_REGISTER (res) = 1;
5195 if (chkp_function_instrumented_p (current_function_decl))
5197 tree return_type = TREE_TYPE (res);
5198 rtx bounds = targetm.calls.chkp_function_value_bounds (return_type,
5199 subr, 1);
5200 SET_DECL_BOUNDS_RTL (res, bounds);
5204 /* Initialize rtx for parameters and local variables.
5205 In some cases this requires emitting insns. */
5206 assign_parms (subr);
5208 /* If function gets a static chain arg, store it. */
5209 if (cfun->static_chain_decl)
5211 tree parm = cfun->static_chain_decl;
5212 rtx local, chain;
5213 rtx_insn *insn;
5214 int unsignedp;
5216 local = gen_reg_rtx (promote_decl_mode (parm, &unsignedp));
5217 chain = targetm.calls.static_chain (current_function_decl, true);
5219 set_decl_incoming_rtl (parm, chain, false);
5220 set_parm_rtl (parm, local);
5221 mark_reg_pointer (local, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
5223 if (GET_MODE (local) != GET_MODE (chain))
5225 convert_move (local, chain, unsignedp);
5226 insn = get_last_insn ();
5228 else
5229 insn = emit_move_insn (local, chain);
5231 /* Mark the register as eliminable, similar to parameters. */
5232 if (MEM_P (chain)
5233 && reg_mentioned_p (arg_pointer_rtx, XEXP (chain, 0)))
5234 set_dst_reg_note (insn, REG_EQUIV, chain, local);
5236 /* If we aren't optimizing, save the static chain onto the stack. */
5237 if (!optimize)
5239 tree saved_static_chain_decl
5240 = build_decl (DECL_SOURCE_LOCATION (parm), VAR_DECL,
5241 DECL_NAME (parm), TREE_TYPE (parm));
5242 rtx saved_static_chain_rtx
5243 = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
5244 SET_DECL_RTL (saved_static_chain_decl, saved_static_chain_rtx);
5245 emit_move_insn (saved_static_chain_rtx, chain);
5246 SET_DECL_VALUE_EXPR (parm, saved_static_chain_decl);
5247 DECL_HAS_VALUE_EXPR_P (parm) = 1;
5251 /* The following was moved from init_function_start.
5252 The move is supposed to make sdb output more accurate. */
5253 /* Indicate the beginning of the function body,
5254 as opposed to parm setup. */
5255 emit_note (NOTE_INSN_FUNCTION_BEG);
5257 gcc_assert (NOTE_P (get_last_insn ()));
5259 parm_birth_insn = get_last_insn ();
5261 /* If the function receives a non-local goto, then store the
5262 bits we need to restore the frame pointer. */
5263 if (cfun->nonlocal_goto_save_area)
5265 tree t_save;
5266 rtx r_save;
5268 tree var = TREE_OPERAND (cfun->nonlocal_goto_save_area, 0);
5269 gcc_assert (DECL_RTL_SET_P (var));
5271 t_save = build4 (ARRAY_REF,
5272 TREE_TYPE (TREE_TYPE (cfun->nonlocal_goto_save_area)),
5273 cfun->nonlocal_goto_save_area,
5274 integer_zero_node, NULL_TREE, NULL_TREE);
5275 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
5276 gcc_assert (GET_MODE (r_save) == Pmode);
5278 emit_move_insn (r_save, targetm.builtin_setjmp_frame_value ());
5279 update_nonlocal_goto_save_area ();
5282 if (crtl->profile)
5284 #ifdef PROFILE_HOOK
5285 PROFILE_HOOK (current_function_funcdef_no);
5286 #endif
5289 /* If we are doing generic stack checking, the probe should go here. */
5290 if (flag_stack_check == GENERIC_STACK_CHECK)
5291 stack_check_probe_note = emit_note (NOTE_INSN_DELETED);
5294 void
5295 pop_dummy_function (void)
5297 pop_cfun ();
5298 in_dummy_function = false;
5301 /* Undo the effects of init_dummy_function_start. */
5302 void
5303 expand_dummy_function_end (void)
5305 gcc_assert (in_dummy_function);
5307 /* End any sequences that failed to be closed due to syntax errors. */
5308 while (in_sequence_p ())
5309 end_sequence ();
5311 /* Outside function body, can't compute type's actual size
5312 until next function's body starts. */
5314 free_after_parsing (cfun);
5315 free_after_compilation (cfun);
5316 pop_dummy_function ();
5319 /* Helper for diddle_return_value. */
5321 void
5322 diddle_return_value_1 (void (*doit) (rtx, void *), void *arg, rtx outgoing)
5324 if (! outgoing)
5325 return;
5327 if (REG_P (outgoing))
5328 (*doit) (outgoing, arg);
5329 else if (GET_CODE (outgoing) == PARALLEL)
5331 int i;
5333 for (i = 0; i < XVECLEN (outgoing, 0); i++)
5335 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
5337 if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
5338 (*doit) (x, arg);
5343 /* Call DOIT for each hard register used as a return value from
5344 the current function. */
5346 void
5347 diddle_return_value (void (*doit) (rtx, void *), void *arg)
5349 diddle_return_value_1 (doit, arg, crtl->return_bnd);
5350 diddle_return_value_1 (doit, arg, crtl->return_rtx);
5353 static void
5354 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
5356 emit_clobber (reg);
5359 void
5360 clobber_return_register (void)
5362 diddle_return_value (do_clobber_return_reg, NULL);
5364 /* In case we do use pseudo to return value, clobber it too. */
5365 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
5367 tree decl_result = DECL_RESULT (current_function_decl);
5368 rtx decl_rtl = DECL_RTL (decl_result);
5369 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
5371 do_clobber_return_reg (decl_rtl, NULL);
5376 static void
5377 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
5379 emit_use (reg);
5382 static void
5383 use_return_register (void)
5385 diddle_return_value (do_use_return_reg, NULL);
5388 /* Set the location of the insn chain starting at INSN to LOC. */
5390 static void
5391 set_insn_locations (rtx_insn *insn, int loc)
5393 while (insn != NULL)
5395 if (INSN_P (insn))
5396 INSN_LOCATION (insn) = loc;
5397 insn = NEXT_INSN (insn);
5401 /* Generate RTL for the end of the current function. */
5403 void
5404 expand_function_end (void)
5406 /* If arg_pointer_save_area was referenced only from a nested
5407 function, we will not have initialized it yet. Do that now. */
5408 if (arg_pointer_save_area && ! crtl->arg_pointer_save_area_init)
5409 get_arg_pointer_save_area ();
5411 /* If we are doing generic stack checking and this function makes calls,
5412 do a stack probe at the start of the function to ensure we have enough
5413 space for another stack frame. */
5414 if (flag_stack_check == GENERIC_STACK_CHECK)
5416 rtx_insn *insn, *seq;
5418 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
5419 if (CALL_P (insn))
5421 rtx max_frame_size = GEN_INT (STACK_CHECK_MAX_FRAME_SIZE);
5422 start_sequence ();
5423 if (STACK_CHECK_MOVING_SP)
5424 anti_adjust_stack_and_probe (max_frame_size, true);
5425 else
5426 probe_stack_range (STACK_OLD_CHECK_PROTECT, max_frame_size);
5427 seq = get_insns ();
5428 end_sequence ();
5429 set_insn_locations (seq, prologue_location);
5430 emit_insn_before (seq, stack_check_probe_note);
5431 break;
5435 /* End any sequences that failed to be closed due to syntax errors. */
5436 while (in_sequence_p ())
5437 end_sequence ();
5439 clear_pending_stack_adjust ();
5440 do_pending_stack_adjust ();
5442 /* Output a linenumber for the end of the function.
5443 SDB depends on this. */
5444 set_curr_insn_location (input_location);
5446 /* Before the return label (if any), clobber the return
5447 registers so that they are not propagated live to the rest of
5448 the function. This can only happen with functions that drop
5449 through; if there had been a return statement, there would
5450 have either been a return rtx, or a jump to the return label.
5452 We delay actual code generation after the current_function_value_rtx
5453 is computed. */
5454 rtx_insn *clobber_after = get_last_insn ();
5456 /* Output the label for the actual return from the function. */
5457 emit_label (return_label);
5459 if (targetm_common.except_unwind_info (&global_options) == UI_SJLJ)
5461 /* Let except.c know where it should emit the call to unregister
5462 the function context for sjlj exceptions. */
5463 if (flag_exceptions)
5464 sjlj_emit_function_exit_after (get_last_insn ());
5466 else
5468 /* We want to ensure that instructions that may trap are not
5469 moved into the epilogue by scheduling, because we don't
5470 always emit unwind information for the epilogue. */
5471 if (cfun->can_throw_non_call_exceptions)
5472 emit_insn (gen_blockage ());
5475 /* If this is an implementation of throw, do what's necessary to
5476 communicate between __builtin_eh_return and the epilogue. */
5477 expand_eh_return ();
5479 /* If scalar return value was computed in a pseudo-reg, or was a named
5480 return value that got dumped to the stack, copy that to the hard
5481 return register. */
5482 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
5484 tree decl_result = DECL_RESULT (current_function_decl);
5485 rtx decl_rtl = DECL_RTL (decl_result);
5487 if (REG_P (decl_rtl)
5488 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
5489 : DECL_REGISTER (decl_result))
5491 rtx real_decl_rtl = crtl->return_rtx;
5492 complex_mode cmode;
5494 /* This should be set in assign_parms. */
5495 gcc_assert (REG_FUNCTION_VALUE_P (real_decl_rtl));
5497 /* If this is a BLKmode structure being returned in registers,
5498 then use the mode computed in expand_return. Note that if
5499 decl_rtl is memory, then its mode may have been changed,
5500 but that crtl->return_rtx has not. */
5501 if (GET_MODE (real_decl_rtl) == BLKmode)
5502 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
5504 /* If a non-BLKmode return value should be padded at the least
5505 significant end of the register, shift it left by the appropriate
5506 amount. BLKmode results are handled using the group load/store
5507 machinery. */
5508 if (TYPE_MODE (TREE_TYPE (decl_result)) != BLKmode
5509 && REG_P (real_decl_rtl)
5510 && targetm.calls.return_in_msb (TREE_TYPE (decl_result)))
5512 emit_move_insn (gen_rtx_REG (GET_MODE (decl_rtl),
5513 REGNO (real_decl_rtl)),
5514 decl_rtl);
5515 shift_return_value (GET_MODE (decl_rtl), true, real_decl_rtl);
5517 else if (GET_CODE (real_decl_rtl) == PARALLEL)
5519 /* If expand_function_start has created a PARALLEL for decl_rtl,
5520 move the result to the real return registers. Otherwise, do
5521 a group load from decl_rtl for a named return. */
5522 if (GET_CODE (decl_rtl) == PARALLEL)
5523 emit_group_move (real_decl_rtl, decl_rtl);
5524 else
5525 emit_group_load (real_decl_rtl, decl_rtl,
5526 TREE_TYPE (decl_result),
5527 int_size_in_bytes (TREE_TYPE (decl_result)));
5529 /* In the case of complex integer modes smaller than a word, we'll
5530 need to generate some non-trivial bitfield insertions. Do that
5531 on a pseudo and not the hard register. */
5532 else if (GET_CODE (decl_rtl) == CONCAT
5533 && is_complex_int_mode (GET_MODE (decl_rtl), &cmode)
5534 && GET_MODE_BITSIZE (cmode) <= BITS_PER_WORD)
5536 int old_generating_concat_p;
5537 rtx tmp;
5539 old_generating_concat_p = generating_concat_p;
5540 generating_concat_p = 0;
5541 tmp = gen_reg_rtx (GET_MODE (decl_rtl));
5542 generating_concat_p = old_generating_concat_p;
5544 emit_move_insn (tmp, decl_rtl);
5545 emit_move_insn (real_decl_rtl, tmp);
5547 /* If a named return value dumped decl_return to memory, then
5548 we may need to re-do the PROMOTE_MODE signed/unsigned
5549 extension. */
5550 else if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
5552 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
5553 promote_function_mode (TREE_TYPE (decl_result),
5554 GET_MODE (decl_rtl), &unsignedp,
5555 TREE_TYPE (current_function_decl), 1);
5557 convert_move (real_decl_rtl, decl_rtl, unsignedp);
5559 else
5560 emit_move_insn (real_decl_rtl, decl_rtl);
5564 /* If returning a structure, arrange to return the address of the value
5565 in a place where debuggers expect to find it.
5567 If returning a structure PCC style,
5568 the caller also depends on this value.
5569 And cfun->returns_pcc_struct is not necessarily set. */
5570 if ((cfun->returns_struct || cfun->returns_pcc_struct)
5571 && !targetm.calls.omit_struct_return_reg)
5573 rtx value_address = DECL_RTL (DECL_RESULT (current_function_decl));
5574 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
5575 rtx outgoing;
5577 if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
5578 type = TREE_TYPE (type);
5579 else
5580 value_address = XEXP (value_address, 0);
5582 outgoing = targetm.calls.function_value (build_pointer_type (type),
5583 current_function_decl, true);
5585 /* Mark this as a function return value so integrate will delete the
5586 assignment and USE below when inlining this function. */
5587 REG_FUNCTION_VALUE_P (outgoing) = 1;
5589 /* The address may be ptr_mode and OUTGOING may be Pmode. */
5590 scalar_int_mode mode = as_a <scalar_int_mode> (GET_MODE (outgoing));
5591 value_address = convert_memory_address (mode, value_address);
5593 emit_move_insn (outgoing, value_address);
5595 /* Show return register used to hold result (in this case the address
5596 of the result. */
5597 crtl->return_rtx = outgoing;
5600 /* Emit the actual code to clobber return register. Don't emit
5601 it if clobber_after is a barrier, then the previous basic block
5602 certainly doesn't fall thru into the exit block. */
5603 if (!BARRIER_P (clobber_after))
5605 start_sequence ();
5606 clobber_return_register ();
5607 rtx_insn *seq = get_insns ();
5608 end_sequence ();
5610 emit_insn_after (seq, clobber_after);
5613 /* Output the label for the naked return from the function. */
5614 if (naked_return_label)
5615 emit_label (naked_return_label);
5617 /* @@@ This is a kludge. We want to ensure that instructions that
5618 may trap are not moved into the epilogue by scheduling, because
5619 we don't always emit unwind information for the epilogue. */
5620 if (cfun->can_throw_non_call_exceptions
5621 && targetm_common.except_unwind_info (&global_options) != UI_SJLJ)
5622 emit_insn (gen_blockage ());
5624 /* If stack protection is enabled for this function, check the guard. */
5625 if (crtl->stack_protect_guard && targetm.stack_protect_runtime_enabled_p ())
5626 stack_protect_epilogue ();
5628 /* If we had calls to alloca, and this machine needs
5629 an accurate stack pointer to exit the function,
5630 insert some code to save and restore the stack pointer. */
5631 if (! EXIT_IGNORE_STACK
5632 && cfun->calls_alloca)
5634 rtx tem = 0;
5636 start_sequence ();
5637 emit_stack_save (SAVE_FUNCTION, &tem);
5638 rtx_insn *seq = get_insns ();
5639 end_sequence ();
5640 emit_insn_before (seq, parm_birth_insn);
5642 emit_stack_restore (SAVE_FUNCTION, tem);
5645 /* ??? This should no longer be necessary since stupid is no longer with
5646 us, but there are some parts of the compiler (eg reload_combine, and
5647 sh mach_dep_reorg) that still try and compute their own lifetime info
5648 instead of using the general framework. */
5649 use_return_register ();
5653 get_arg_pointer_save_area (void)
5655 rtx ret = arg_pointer_save_area;
5657 if (! ret)
5659 ret = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
5660 arg_pointer_save_area = ret;
5663 if (! crtl->arg_pointer_save_area_init)
5665 /* Save the arg pointer at the beginning of the function. The
5666 generated stack slot may not be a valid memory address, so we
5667 have to check it and fix it if necessary. */
5668 start_sequence ();
5669 emit_move_insn (validize_mem (copy_rtx (ret)),
5670 crtl->args.internal_arg_pointer);
5671 rtx_insn *seq = get_insns ();
5672 end_sequence ();
5674 push_topmost_sequence ();
5675 emit_insn_after (seq, entry_of_function ());
5676 pop_topmost_sequence ();
5678 crtl->arg_pointer_save_area_init = true;
5681 return ret;
5685 /* If debugging dumps are requested, dump information about how the
5686 target handled -fstack-check=clash for the prologue.
5688 PROBES describes what if any probes were emitted.
5690 RESIDUALS indicates if the prologue had any residual allocation
5691 (i.e. total allocation was not a multiple of PROBE_INTERVAL). */
5693 void
5694 dump_stack_clash_frame_info (enum stack_clash_probes probes, bool residuals)
5696 if (!dump_file)
5697 return;
5699 switch (probes)
5701 case NO_PROBE_NO_FRAME:
5702 fprintf (dump_file,
5703 "Stack clash no probe no stack adjustment in prologue.\n");
5704 break;
5705 case NO_PROBE_SMALL_FRAME:
5706 fprintf (dump_file,
5707 "Stack clash no probe small stack adjustment in prologue.\n");
5708 break;
5709 case PROBE_INLINE:
5710 fprintf (dump_file, "Stack clash inline probes in prologue.\n");
5711 break;
5712 case PROBE_LOOP:
5713 fprintf (dump_file, "Stack clash probe loop in prologue.\n");
5714 break;
5717 if (residuals)
5718 fprintf (dump_file, "Stack clash residual allocation in prologue.\n");
5719 else
5720 fprintf (dump_file, "Stack clash no residual allocation in prologue.\n");
5722 if (frame_pointer_needed)
5723 fprintf (dump_file, "Stack clash frame pointer needed.\n");
5724 else
5725 fprintf (dump_file, "Stack clash no frame pointer needed.\n");
5727 if (TREE_THIS_VOLATILE (cfun->decl))
5728 fprintf (dump_file,
5729 "Stack clash noreturn prologue, assuming no implicit"
5730 " probes in caller.\n");
5731 else
5732 fprintf (dump_file,
5733 "Stack clash not noreturn prologue.\n");
5736 /* Add a list of INSNS to the hash HASHP, possibly allocating HASHP
5737 for the first time. */
5739 static void
5740 record_insns (rtx_insn *insns, rtx end, hash_table<insn_cache_hasher> **hashp)
5742 rtx_insn *tmp;
5743 hash_table<insn_cache_hasher> *hash = *hashp;
5745 if (hash == NULL)
5746 *hashp = hash = hash_table<insn_cache_hasher>::create_ggc (17);
5748 for (tmp = insns; tmp != end; tmp = NEXT_INSN (tmp))
5750 rtx *slot = hash->find_slot (tmp, INSERT);
5751 gcc_assert (*slot == NULL);
5752 *slot = tmp;
5756 /* INSN has been duplicated or replaced by as COPY, perhaps by duplicating a
5757 basic block, splitting or peepholes. If INSN is a prologue or epilogue
5758 insn, then record COPY as well. */
5760 void
5761 maybe_copy_prologue_epilogue_insn (rtx insn, rtx copy)
5763 hash_table<insn_cache_hasher> *hash;
5764 rtx *slot;
5766 hash = epilogue_insn_hash;
5767 if (!hash || !hash->find (insn))
5769 hash = prologue_insn_hash;
5770 if (!hash || !hash->find (insn))
5771 return;
5774 slot = hash->find_slot (copy, INSERT);
5775 gcc_assert (*slot == NULL);
5776 *slot = copy;
5779 /* Determine if any INSNs in HASH are, or are part of, INSN. Because
5780 we can be running after reorg, SEQUENCE rtl is possible. */
5782 static bool
5783 contains (const rtx_insn *insn, hash_table<insn_cache_hasher> *hash)
5785 if (hash == NULL)
5786 return false;
5788 if (NONJUMP_INSN_P (insn) && GET_CODE (PATTERN (insn)) == SEQUENCE)
5790 rtx_sequence *seq = as_a <rtx_sequence *> (PATTERN (insn));
5791 int i;
5792 for (i = seq->len () - 1; i >= 0; i--)
5793 if (hash->find (seq->element (i)))
5794 return true;
5795 return false;
5798 return hash->find (const_cast<rtx_insn *> (insn)) != NULL;
5802 prologue_contains (const rtx_insn *insn)
5804 return contains (insn, prologue_insn_hash);
5808 epilogue_contains (const rtx_insn *insn)
5810 return contains (insn, epilogue_insn_hash);
5814 prologue_epilogue_contains (const rtx_insn *insn)
5816 if (contains (insn, prologue_insn_hash))
5817 return 1;
5818 if (contains (insn, epilogue_insn_hash))
5819 return 1;
5820 return 0;
5823 void
5824 record_prologue_seq (rtx_insn *seq)
5826 record_insns (seq, NULL, &prologue_insn_hash);
5829 void
5830 record_epilogue_seq (rtx_insn *seq)
5832 record_insns (seq, NULL, &epilogue_insn_hash);
5835 /* Set JUMP_LABEL for a return insn. */
5837 void
5838 set_return_jump_label (rtx_insn *returnjump)
5840 rtx pat = PATTERN (returnjump);
5841 if (GET_CODE (pat) == PARALLEL)
5842 pat = XVECEXP (pat, 0, 0);
5843 if (ANY_RETURN_P (pat))
5844 JUMP_LABEL (returnjump) = pat;
5845 else
5846 JUMP_LABEL (returnjump) = ret_rtx;
5849 /* Return a sequence to be used as the split prologue for the current
5850 function, or NULL. */
5852 static rtx_insn *
5853 make_split_prologue_seq (void)
5855 if (!flag_split_stack
5856 || lookup_attribute ("no_split_stack", DECL_ATTRIBUTES (cfun->decl)))
5857 return NULL;
5859 start_sequence ();
5860 emit_insn (targetm.gen_split_stack_prologue ());
5861 rtx_insn *seq = get_insns ();
5862 end_sequence ();
5864 record_insns (seq, NULL, &prologue_insn_hash);
5865 set_insn_locations (seq, prologue_location);
5867 return seq;
5870 /* Return a sequence to be used as the prologue for the current function,
5871 or NULL. */
5873 static rtx_insn *
5874 make_prologue_seq (void)
5876 if (!targetm.have_prologue ())
5877 return NULL;
5879 start_sequence ();
5880 rtx_insn *seq = targetm.gen_prologue ();
5881 emit_insn (seq);
5883 /* Insert an explicit USE for the frame pointer
5884 if the profiling is on and the frame pointer is required. */
5885 if (crtl->profile && frame_pointer_needed)
5886 emit_use (hard_frame_pointer_rtx);
5888 /* Retain a map of the prologue insns. */
5889 record_insns (seq, NULL, &prologue_insn_hash);
5890 emit_note (NOTE_INSN_PROLOGUE_END);
5892 /* Ensure that instructions are not moved into the prologue when
5893 profiling is on. The call to the profiling routine can be
5894 emitted within the live range of a call-clobbered register. */
5895 if (!targetm.profile_before_prologue () && crtl->profile)
5896 emit_insn (gen_blockage ());
5898 seq = get_insns ();
5899 end_sequence ();
5900 set_insn_locations (seq, prologue_location);
5902 return seq;
5905 /* Return a sequence to be used as the epilogue for the current function,
5906 or NULL. */
5908 static rtx_insn *
5909 make_epilogue_seq (void)
5911 if (!targetm.have_epilogue ())
5912 return NULL;
5914 start_sequence ();
5915 emit_note (NOTE_INSN_EPILOGUE_BEG);
5916 rtx_insn *seq = targetm.gen_epilogue ();
5917 if (seq)
5918 emit_jump_insn (seq);
5920 /* Retain a map of the epilogue insns. */
5921 record_insns (seq, NULL, &epilogue_insn_hash);
5922 set_insn_locations (seq, epilogue_location);
5924 seq = get_insns ();
5925 rtx_insn *returnjump = get_last_insn ();
5926 end_sequence ();
5928 if (JUMP_P (returnjump))
5929 set_return_jump_label (returnjump);
5931 return seq;
5935 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
5936 this into place with notes indicating where the prologue ends and where
5937 the epilogue begins. Update the basic block information when possible.
5939 Notes on epilogue placement:
5940 There are several kinds of edges to the exit block:
5941 * a single fallthru edge from LAST_BB
5942 * possibly, edges from blocks containing sibcalls
5943 * possibly, fake edges from infinite loops
5945 The epilogue is always emitted on the fallthru edge from the last basic
5946 block in the function, LAST_BB, into the exit block.
5948 If LAST_BB is empty except for a label, it is the target of every
5949 other basic block in the function that ends in a return. If a
5950 target has a return or simple_return pattern (possibly with
5951 conditional variants), these basic blocks can be changed so that a
5952 return insn is emitted into them, and their target is adjusted to
5953 the real exit block.
5955 Notes on shrink wrapping: We implement a fairly conservative
5956 version of shrink-wrapping rather than the textbook one. We only
5957 generate a single prologue and a single epilogue. This is
5958 sufficient to catch a number of interesting cases involving early
5959 exits.
5961 First, we identify the blocks that require the prologue to occur before
5962 them. These are the ones that modify a call-saved register, or reference
5963 any of the stack or frame pointer registers. To simplify things, we then
5964 mark everything reachable from these blocks as also requiring a prologue.
5965 This takes care of loops automatically, and avoids the need to examine
5966 whether MEMs reference the frame, since it is sufficient to check for
5967 occurrences of the stack or frame pointer.
5969 We then compute the set of blocks for which the need for a prologue
5970 is anticipatable (borrowing terminology from the shrink-wrapping
5971 description in Muchnick's book). These are the blocks which either
5972 require a prologue themselves, or those that have only successors
5973 where the prologue is anticipatable. The prologue needs to be
5974 inserted on all edges from BB1->BB2 where BB2 is in ANTIC and BB1
5975 is not. For the moment, we ensure that only one such edge exists.
5977 The epilogue is placed as described above, but we make a
5978 distinction between inserting return and simple_return patterns
5979 when modifying other blocks that end in a return. Blocks that end
5980 in a sibcall omit the sibcall_epilogue if the block is not in
5981 ANTIC. */
5983 void
5984 thread_prologue_and_epilogue_insns (void)
5986 df_analyze ();
5988 /* Can't deal with multiple successors of the entry block at the
5989 moment. Function should always have at least one entry
5990 point. */
5991 gcc_assert (single_succ_p (ENTRY_BLOCK_PTR_FOR_FN (cfun)));
5993 edge entry_edge = single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (cfun));
5994 edge orig_entry_edge = entry_edge;
5996 rtx_insn *split_prologue_seq = make_split_prologue_seq ();
5997 rtx_insn *prologue_seq = make_prologue_seq ();
5998 rtx_insn *epilogue_seq = make_epilogue_seq ();
6000 /* Try to perform a kind of shrink-wrapping, making sure the
6001 prologue/epilogue is emitted only around those parts of the
6002 function that require it. */
6003 try_shrink_wrapping (&entry_edge, prologue_seq);
6005 /* If the target can handle splitting the prologue/epilogue into separate
6006 components, try to shrink-wrap these components separately. */
6007 try_shrink_wrapping_separate (entry_edge->dest);
6009 /* If that did anything for any component we now need the generate the
6010 "main" prologue again. Because some targets require some of these
6011 to be called in a specific order (i386 requires the split prologue
6012 to be first, for example), we create all three sequences again here.
6013 If this does not work for some target, that target should not enable
6014 separate shrink-wrapping. */
6015 if (crtl->shrink_wrapped_separate)
6017 split_prologue_seq = make_split_prologue_seq ();
6018 prologue_seq = make_prologue_seq ();
6019 epilogue_seq = make_epilogue_seq ();
6022 rtl_profile_for_bb (EXIT_BLOCK_PTR_FOR_FN (cfun));
6024 /* A small fib -- epilogue is not yet completed, but we wish to re-use
6025 this marker for the splits of EH_RETURN patterns, and nothing else
6026 uses the flag in the meantime. */
6027 epilogue_completed = 1;
6029 /* Find non-fallthru edges that end with EH_RETURN instructions. On
6030 some targets, these get split to a special version of the epilogue
6031 code. In order to be able to properly annotate these with unwind
6032 info, try to split them now. If we get a valid split, drop an
6033 EPILOGUE_BEG note and mark the insns as epilogue insns. */
6034 edge e;
6035 edge_iterator ei;
6036 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
6038 rtx_insn *prev, *last, *trial;
6040 if (e->flags & EDGE_FALLTHRU)
6041 continue;
6042 last = BB_END (e->src);
6043 if (!eh_returnjump_p (last))
6044 continue;
6046 prev = PREV_INSN (last);
6047 trial = try_split (PATTERN (last), last, 1);
6048 if (trial == last)
6049 continue;
6051 record_insns (NEXT_INSN (prev), NEXT_INSN (trial), &epilogue_insn_hash);
6052 emit_note_after (NOTE_INSN_EPILOGUE_BEG, prev);
6055 edge exit_fallthru_edge = find_fallthru_edge (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds);
6057 if (exit_fallthru_edge)
6059 if (epilogue_seq)
6061 insert_insn_on_edge (epilogue_seq, exit_fallthru_edge);
6062 commit_edge_insertions ();
6064 /* The epilogue insns we inserted may cause the exit edge to no longer
6065 be fallthru. */
6066 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
6068 if (((e->flags & EDGE_FALLTHRU) != 0)
6069 && returnjump_p (BB_END (e->src)))
6070 e->flags &= ~EDGE_FALLTHRU;
6073 else if (next_active_insn (BB_END (exit_fallthru_edge->src)))
6075 /* We have a fall-through edge to the exit block, the source is not
6076 at the end of the function, and there will be an assembler epilogue
6077 at the end of the function.
6078 We can't use force_nonfallthru here, because that would try to
6079 use return. Inserting a jump 'by hand' is extremely messy, so
6080 we take advantage of cfg_layout_finalize using
6081 fixup_fallthru_exit_predecessor. */
6082 cfg_layout_initialize (0);
6083 basic_block cur_bb;
6084 FOR_EACH_BB_FN (cur_bb, cfun)
6085 if (cur_bb->index >= NUM_FIXED_BLOCKS
6086 && cur_bb->next_bb->index >= NUM_FIXED_BLOCKS)
6087 cur_bb->aux = cur_bb->next_bb;
6088 cfg_layout_finalize ();
6092 /* Insert the prologue. */
6094 rtl_profile_for_bb (ENTRY_BLOCK_PTR_FOR_FN (cfun));
6096 if (split_prologue_seq || prologue_seq)
6098 rtx_insn *split_prologue_insn = split_prologue_seq;
6099 if (split_prologue_seq)
6101 while (split_prologue_insn && !NONDEBUG_INSN_P (split_prologue_insn))
6102 split_prologue_insn = NEXT_INSN (split_prologue_insn);
6103 insert_insn_on_edge (split_prologue_seq, orig_entry_edge);
6106 rtx_insn *prologue_insn = prologue_seq;
6107 if (prologue_seq)
6109 while (prologue_insn && !NONDEBUG_INSN_P (prologue_insn))
6110 prologue_insn = NEXT_INSN (prologue_insn);
6111 insert_insn_on_edge (prologue_seq, entry_edge);
6114 commit_edge_insertions ();
6116 /* Look for basic blocks within the prologue insns. */
6117 if (split_prologue_insn
6118 && BLOCK_FOR_INSN (split_prologue_insn) == NULL)
6119 split_prologue_insn = NULL;
6120 if (prologue_insn
6121 && BLOCK_FOR_INSN (prologue_insn) == NULL)
6122 prologue_insn = NULL;
6123 if (split_prologue_insn || prologue_insn)
6125 auto_sbitmap blocks (last_basic_block_for_fn (cfun));
6126 bitmap_clear (blocks);
6127 if (split_prologue_insn)
6128 bitmap_set_bit (blocks,
6129 BLOCK_FOR_INSN (split_prologue_insn)->index);
6130 if (prologue_insn)
6131 bitmap_set_bit (blocks, BLOCK_FOR_INSN (prologue_insn)->index);
6132 find_many_sub_basic_blocks (blocks);
6136 default_rtl_profile ();
6138 /* Emit sibling epilogues before any sibling call sites. */
6139 for (ei = ei_start (EXIT_BLOCK_PTR_FOR_FN (cfun)->preds);
6140 (e = ei_safe_edge (ei));
6141 ei_next (&ei))
6143 /* Skip those already handled, the ones that run without prologue. */
6144 if (e->flags & EDGE_IGNORE)
6146 e->flags &= ~EDGE_IGNORE;
6147 continue;
6150 rtx_insn *insn = BB_END (e->src);
6152 if (!(CALL_P (insn) && SIBLING_CALL_P (insn)))
6153 continue;
6155 if (rtx_insn *ep_seq = targetm.gen_sibcall_epilogue ())
6157 start_sequence ();
6158 emit_note (NOTE_INSN_EPILOGUE_BEG);
6159 emit_insn (ep_seq);
6160 rtx_insn *seq = get_insns ();
6161 end_sequence ();
6163 /* Retain a map of the epilogue insns. Used in life analysis to
6164 avoid getting rid of sibcall epilogue insns. Do this before we
6165 actually emit the sequence. */
6166 record_insns (seq, NULL, &epilogue_insn_hash);
6167 set_insn_locations (seq, epilogue_location);
6169 emit_insn_before (seq, insn);
6173 if (epilogue_seq)
6175 rtx_insn *insn, *next;
6177 /* Similarly, move any line notes that appear after the epilogue.
6178 There is no need, however, to be quite so anal about the existence
6179 of such a note. Also possibly move
6180 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
6181 info generation. */
6182 for (insn = epilogue_seq; insn; insn = next)
6184 next = NEXT_INSN (insn);
6185 if (NOTE_P (insn)
6186 && (NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG))
6187 reorder_insns (insn, insn, PREV_INSN (epilogue_seq));
6191 /* Threading the prologue and epilogue changes the artificial refs
6192 in the entry and exit blocks. */
6193 epilogue_completed = 1;
6194 df_update_entry_exit_and_calls ();
6197 /* Reposition the prologue-end and epilogue-begin notes after
6198 instruction scheduling. */
6200 void
6201 reposition_prologue_and_epilogue_notes (void)
6203 if (!targetm.have_prologue ()
6204 && !targetm.have_epilogue ()
6205 && !targetm.have_sibcall_epilogue ())
6206 return;
6208 /* Since the hash table is created on demand, the fact that it is
6209 non-null is a signal that it is non-empty. */
6210 if (prologue_insn_hash != NULL)
6212 size_t len = prologue_insn_hash->elements ();
6213 rtx_insn *insn, *last = NULL, *note = NULL;
6215 /* Scan from the beginning until we reach the last prologue insn. */
6216 /* ??? While we do have the CFG intact, there are two problems:
6217 (1) The prologue can contain loops (typically probing the stack),
6218 which means that the end of the prologue isn't in the first bb.
6219 (2) Sometimes the PROLOGUE_END note gets pushed into the next bb. */
6220 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
6222 if (NOTE_P (insn))
6224 if (NOTE_KIND (insn) == NOTE_INSN_PROLOGUE_END)
6225 note = insn;
6227 else if (contains (insn, prologue_insn_hash))
6229 last = insn;
6230 if (--len == 0)
6231 break;
6235 if (last)
6237 if (note == NULL)
6239 /* Scan forward looking for the PROLOGUE_END note. It should
6240 be right at the beginning of the block, possibly with other
6241 insn notes that got moved there. */
6242 for (note = NEXT_INSN (last); ; note = NEXT_INSN (note))
6244 if (NOTE_P (note)
6245 && NOTE_KIND (note) == NOTE_INSN_PROLOGUE_END)
6246 break;
6250 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
6251 if (LABEL_P (last))
6252 last = NEXT_INSN (last);
6253 reorder_insns (note, note, last);
6257 if (epilogue_insn_hash != NULL)
6259 edge_iterator ei;
6260 edge e;
6262 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR_FOR_FN (cfun)->preds)
6264 rtx_insn *insn, *first = NULL, *note = NULL;
6265 basic_block bb = e->src;
6267 /* Scan from the beginning until we reach the first epilogue insn. */
6268 FOR_BB_INSNS (bb, insn)
6270 if (NOTE_P (insn))
6272 if (NOTE_KIND (insn) == NOTE_INSN_EPILOGUE_BEG)
6274 note = insn;
6275 if (first != NULL)
6276 break;
6279 else if (first == NULL && contains (insn, epilogue_insn_hash))
6281 first = insn;
6282 if (note != NULL)
6283 break;
6287 if (note)
6289 /* If the function has a single basic block, and no real
6290 epilogue insns (e.g. sibcall with no cleanup), the
6291 epilogue note can get scheduled before the prologue
6292 note. If we have frame related prologue insns, having
6293 them scanned during the epilogue will result in a crash.
6294 In this case re-order the epilogue note to just before
6295 the last insn in the block. */
6296 if (first == NULL)
6297 first = BB_END (bb);
6299 if (PREV_INSN (first) != note)
6300 reorder_insns (note, note, PREV_INSN (first));
6306 /* Returns the name of function declared by FNDECL. */
6307 const char *
6308 fndecl_name (tree fndecl)
6310 if (fndecl == NULL)
6311 return "(nofn)";
6312 return lang_hooks.decl_printable_name (fndecl, 1);
6315 /* Returns the name of function FN. */
6316 const char *
6317 function_name (struct function *fn)
6319 tree fndecl = (fn == NULL) ? NULL : fn->decl;
6320 return fndecl_name (fndecl);
6323 /* Returns the name of the current function. */
6324 const char *
6325 current_function_name (void)
6327 return function_name (cfun);
6331 static unsigned int
6332 rest_of_handle_check_leaf_regs (void)
6334 #ifdef LEAF_REGISTERS
6335 crtl->uses_only_leaf_regs
6336 = optimize > 0 && only_leaf_regs_used () && leaf_function_p ();
6337 #endif
6338 return 0;
6341 /* Insert a TYPE into the used types hash table of CFUN. */
6343 static void
6344 used_types_insert_helper (tree type, struct function *func)
6346 if (type != NULL && func != NULL)
6348 if (func->used_types_hash == NULL)
6349 func->used_types_hash = hash_set<tree>::create_ggc (37);
6351 func->used_types_hash->add (type);
6355 /* Given a type, insert it into the used hash table in cfun. */
6356 void
6357 used_types_insert (tree t)
6359 while (POINTER_TYPE_P (t) || TREE_CODE (t) == ARRAY_TYPE)
6360 if (TYPE_NAME (t))
6361 break;
6362 else
6363 t = TREE_TYPE (t);
6364 if (TREE_CODE (t) == ERROR_MARK)
6365 return;
6366 if (TYPE_NAME (t) == NULL_TREE
6367 || TYPE_NAME (t) == TYPE_NAME (TYPE_MAIN_VARIANT (t)))
6368 t = TYPE_MAIN_VARIANT (t);
6369 if (debug_info_level > DINFO_LEVEL_NONE)
6371 if (cfun)
6372 used_types_insert_helper (t, cfun);
6373 else
6375 /* So this might be a type referenced by a global variable.
6376 Record that type so that we can later decide to emit its
6377 debug information. */
6378 vec_safe_push (types_used_by_cur_var_decl, t);
6383 /* Helper to Hash a struct types_used_by_vars_entry. */
6385 static hashval_t
6386 hash_types_used_by_vars_entry (const struct types_used_by_vars_entry *entry)
6388 gcc_assert (entry && entry->var_decl && entry->type);
6390 return iterative_hash_object (entry->type,
6391 iterative_hash_object (entry->var_decl, 0));
6394 /* Hash function of the types_used_by_vars_entry hash table. */
6396 hashval_t
6397 used_type_hasher::hash (types_used_by_vars_entry *entry)
6399 return hash_types_used_by_vars_entry (entry);
6402 /*Equality function of the types_used_by_vars_entry hash table. */
6404 bool
6405 used_type_hasher::equal (types_used_by_vars_entry *e1,
6406 types_used_by_vars_entry *e2)
6408 return (e1->var_decl == e2->var_decl && e1->type == e2->type);
6411 /* Inserts an entry into the types_used_by_vars_hash hash table. */
6413 void
6414 types_used_by_var_decl_insert (tree type, tree var_decl)
6416 if (type != NULL && var_decl != NULL)
6418 types_used_by_vars_entry **slot;
6419 struct types_used_by_vars_entry e;
6420 e.var_decl = var_decl;
6421 e.type = type;
6422 if (types_used_by_vars_hash == NULL)
6423 types_used_by_vars_hash
6424 = hash_table<used_type_hasher>::create_ggc (37);
6426 slot = types_used_by_vars_hash->find_slot (&e, INSERT);
6427 if (*slot == NULL)
6429 struct types_used_by_vars_entry *entry;
6430 entry = ggc_alloc<types_used_by_vars_entry> ();
6431 entry->type = type;
6432 entry->var_decl = var_decl;
6433 *slot = entry;
6438 namespace {
6440 const pass_data pass_data_leaf_regs =
6442 RTL_PASS, /* type */
6443 "*leaf_regs", /* name */
6444 OPTGROUP_NONE, /* optinfo_flags */
6445 TV_NONE, /* tv_id */
6446 0, /* properties_required */
6447 0, /* properties_provided */
6448 0, /* properties_destroyed */
6449 0, /* todo_flags_start */
6450 0, /* todo_flags_finish */
6453 class pass_leaf_regs : public rtl_opt_pass
6455 public:
6456 pass_leaf_regs (gcc::context *ctxt)
6457 : rtl_opt_pass (pass_data_leaf_regs, ctxt)
6460 /* opt_pass methods: */
6461 virtual unsigned int execute (function *)
6463 return rest_of_handle_check_leaf_regs ();
6466 }; // class pass_leaf_regs
6468 } // anon namespace
6470 rtl_opt_pass *
6471 make_pass_leaf_regs (gcc::context *ctxt)
6473 return new pass_leaf_regs (ctxt);
6476 static unsigned int
6477 rest_of_handle_thread_prologue_and_epilogue (void)
6479 /* prepare_shrink_wrap is sensitive to the block structure of the control
6480 flow graph, so clean it up first. */
6481 if (optimize)
6482 cleanup_cfg (0);
6484 /* On some machines, the prologue and epilogue code, or parts thereof,
6485 can be represented as RTL. Doing so lets us schedule insns between
6486 it and the rest of the code and also allows delayed branch
6487 scheduling to operate in the epilogue. */
6488 thread_prologue_and_epilogue_insns ();
6490 /* Some non-cold blocks may now be only reachable from cold blocks.
6491 Fix that up. */
6492 fixup_partitions ();
6494 /* Shrink-wrapping can result in unreachable edges in the epilogue,
6495 see PR57320. */
6496 cleanup_cfg (optimize ? CLEANUP_EXPENSIVE : 0);
6498 /* The stack usage info is finalized during prologue expansion. */
6499 if (flag_stack_usage_info)
6500 output_stack_usage ();
6502 return 0;
6505 namespace {
6507 const pass_data pass_data_thread_prologue_and_epilogue =
6509 RTL_PASS, /* type */
6510 "pro_and_epilogue", /* name */
6511 OPTGROUP_NONE, /* optinfo_flags */
6512 TV_THREAD_PROLOGUE_AND_EPILOGUE, /* tv_id */
6513 0, /* properties_required */
6514 0, /* properties_provided */
6515 0, /* properties_destroyed */
6516 0, /* todo_flags_start */
6517 ( TODO_df_verify | TODO_df_finish ), /* todo_flags_finish */
6520 class pass_thread_prologue_and_epilogue : public rtl_opt_pass
6522 public:
6523 pass_thread_prologue_and_epilogue (gcc::context *ctxt)
6524 : rtl_opt_pass (pass_data_thread_prologue_and_epilogue, ctxt)
6527 /* opt_pass methods: */
6528 virtual unsigned int execute (function *)
6530 return rest_of_handle_thread_prologue_and_epilogue ();
6533 }; // class pass_thread_prologue_and_epilogue
6535 } // anon namespace
6537 rtl_opt_pass *
6538 make_pass_thread_prologue_and_epilogue (gcc::context *ctxt)
6540 return new pass_thread_prologue_and_epilogue (ctxt);
6544 /* This mini-pass fixes fall-out from SSA in asm statements that have
6545 in-out constraints. Say you start with
6547 orig = inout;
6548 asm ("": "+mr" (inout));
6549 use (orig);
6551 which is transformed very early to use explicit output and match operands:
6553 orig = inout;
6554 asm ("": "=mr" (inout) : "0" (inout));
6555 use (orig);
6557 Or, after SSA and copyprop,
6559 asm ("": "=mr" (inout_2) : "0" (inout_1));
6560 use (inout_1);
6562 Clearly inout_2 and inout_1 can't be coalesced easily anymore, as
6563 they represent two separate values, so they will get different pseudo
6564 registers during expansion. Then, since the two operands need to match
6565 per the constraints, but use different pseudo registers, reload can
6566 only register a reload for these operands. But reloads can only be
6567 satisfied by hardregs, not by memory, so we need a register for this
6568 reload, just because we are presented with non-matching operands.
6569 So, even though we allow memory for this operand, no memory can be
6570 used for it, just because the two operands don't match. This can
6571 cause reload failures on register-starved targets.
6573 So it's a symptom of reload not being able to use memory for reloads
6574 or, alternatively it's also a symptom of both operands not coming into
6575 reload as matching (in which case the pseudo could go to memory just
6576 fine, as the alternative allows it, and no reload would be necessary).
6577 We fix the latter problem here, by transforming
6579 asm ("": "=mr" (inout_2) : "0" (inout_1));
6581 back to
6583 inout_2 = inout_1;
6584 asm ("": "=mr" (inout_2) : "0" (inout_2)); */
6586 static void
6587 match_asm_constraints_1 (rtx_insn *insn, rtx *p_sets, int noutputs)
6589 int i;
6590 bool changed = false;
6591 rtx op = SET_SRC (p_sets[0]);
6592 int ninputs = ASM_OPERANDS_INPUT_LENGTH (op);
6593 rtvec inputs = ASM_OPERANDS_INPUT_VEC (op);
6594 bool *output_matched = XALLOCAVEC (bool, noutputs);
6596 memset (output_matched, 0, noutputs * sizeof (bool));
6597 for (i = 0; i < ninputs; i++)
6599 rtx input, output;
6600 rtx_insn *insns;
6601 const char *constraint = ASM_OPERANDS_INPUT_CONSTRAINT (op, i);
6602 char *end;
6603 int match, j;
6605 if (*constraint == '%')
6606 constraint++;
6608 match = strtoul (constraint, &end, 10);
6609 if (end == constraint)
6610 continue;
6612 gcc_assert (match < noutputs);
6613 output = SET_DEST (p_sets[match]);
6614 input = RTVEC_ELT (inputs, i);
6615 /* Only do the transformation for pseudos. */
6616 if (! REG_P (output)
6617 || rtx_equal_p (output, input)
6618 || (GET_MODE (input) != VOIDmode
6619 && GET_MODE (input) != GET_MODE (output)))
6620 continue;
6622 /* We can't do anything if the output is also used as input,
6623 as we're going to overwrite it. */
6624 for (j = 0; j < ninputs; j++)
6625 if (reg_overlap_mentioned_p (output, RTVEC_ELT (inputs, j)))
6626 break;
6627 if (j != ninputs)
6628 continue;
6630 /* Avoid changing the same input several times. For
6631 asm ("" : "=mr" (out1), "=mr" (out2) : "0" (in), "1" (in));
6632 only change in once (to out1), rather than changing it
6633 first to out1 and afterwards to out2. */
6634 if (i > 0)
6636 for (j = 0; j < noutputs; j++)
6637 if (output_matched[j] && input == SET_DEST (p_sets[j]))
6638 break;
6639 if (j != noutputs)
6640 continue;
6642 output_matched[match] = true;
6644 start_sequence ();
6645 emit_move_insn (output, input);
6646 insns = get_insns ();
6647 end_sequence ();
6648 emit_insn_before (insns, insn);
6650 /* Now replace all mentions of the input with output. We can't
6651 just replace the occurrence in inputs[i], as the register might
6652 also be used in some other input (or even in an address of an
6653 output), which would mean possibly increasing the number of
6654 inputs by one (namely 'output' in addition), which might pose
6655 a too complicated problem for reload to solve. E.g. this situation:
6657 asm ("" : "=r" (output), "=m" (input) : "0" (input))
6659 Here 'input' is used in two occurrences as input (once for the
6660 input operand, once for the address in the second output operand).
6661 If we would replace only the occurrence of the input operand (to
6662 make the matching) we would be left with this:
6664 output = input
6665 asm ("" : "=r" (output), "=m" (input) : "0" (output))
6667 Now we suddenly have two different input values (containing the same
6668 value, but different pseudos) where we formerly had only one.
6669 With more complicated asms this might lead to reload failures
6670 which wouldn't have happen without this pass. So, iterate over
6671 all operands and replace all occurrences of the register used. */
6672 for (j = 0; j < noutputs; j++)
6673 if (!rtx_equal_p (SET_DEST (p_sets[j]), input)
6674 && reg_overlap_mentioned_p (input, SET_DEST (p_sets[j])))
6675 SET_DEST (p_sets[j]) = replace_rtx (SET_DEST (p_sets[j]),
6676 input, output);
6677 for (j = 0; j < ninputs; j++)
6678 if (reg_overlap_mentioned_p (input, RTVEC_ELT (inputs, j)))
6679 RTVEC_ELT (inputs, j) = replace_rtx (RTVEC_ELT (inputs, j),
6680 input, output);
6682 changed = true;
6685 if (changed)
6686 df_insn_rescan (insn);
6689 /* Add the decl D to the local_decls list of FUN. */
6691 void
6692 add_local_decl (struct function *fun, tree d)
6694 gcc_assert (VAR_P (d));
6695 vec_safe_push (fun->local_decls, d);
6698 namespace {
6700 const pass_data pass_data_match_asm_constraints =
6702 RTL_PASS, /* type */
6703 "asmcons", /* name */
6704 OPTGROUP_NONE, /* optinfo_flags */
6705 TV_NONE, /* tv_id */
6706 0, /* properties_required */
6707 0, /* properties_provided */
6708 0, /* properties_destroyed */
6709 0, /* todo_flags_start */
6710 0, /* todo_flags_finish */
6713 class pass_match_asm_constraints : public rtl_opt_pass
6715 public:
6716 pass_match_asm_constraints (gcc::context *ctxt)
6717 : rtl_opt_pass (pass_data_match_asm_constraints, ctxt)
6720 /* opt_pass methods: */
6721 virtual unsigned int execute (function *);
6723 }; // class pass_match_asm_constraints
6725 unsigned
6726 pass_match_asm_constraints::execute (function *fun)
6728 basic_block bb;
6729 rtx_insn *insn;
6730 rtx pat, *p_sets;
6731 int noutputs;
6733 if (!crtl->has_asm_statement)
6734 return 0;
6736 df_set_flags (DF_DEFER_INSN_RESCAN);
6737 FOR_EACH_BB_FN (bb, fun)
6739 FOR_BB_INSNS (bb, insn)
6741 if (!INSN_P (insn))
6742 continue;
6744 pat = PATTERN (insn);
6745 if (GET_CODE (pat) == PARALLEL)
6746 p_sets = &XVECEXP (pat, 0, 0), noutputs = XVECLEN (pat, 0);
6747 else if (GET_CODE (pat) == SET)
6748 p_sets = &PATTERN (insn), noutputs = 1;
6749 else
6750 continue;
6752 if (GET_CODE (*p_sets) == SET
6753 && GET_CODE (SET_SRC (*p_sets)) == ASM_OPERANDS)
6754 match_asm_constraints_1 (insn, p_sets, noutputs);
6758 return TODO_df_finish;
6761 } // anon namespace
6763 rtl_opt_pass *
6764 make_pass_match_asm_constraints (gcc::context *ctxt)
6766 return new pass_match_asm_constraints (ctxt);
6770 #include "gt-function.h"