1 /* Expands front end tree to back end RTL for GCC.
2 Copyright (C) 1987, 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* This file handles the generation of rtl code from tree structure
23 at the level of the function as a whole.
24 It creates the rtl expressions for parameters and auto variables
25 and has full responsibility for allocating stack slots.
27 `expand_function_start' is called at the beginning of a function,
28 before the function body is parsed, and `expand_function_end' is
29 called after parsing the body.
31 Call `assign_stack_local' to allocate a stack slot for a local variable.
32 This is usually done during the RTL generation for the function body,
33 but it can also be done in the reload pass when a pseudo-register does
34 not get a hard register. */
38 #include "coretypes.h"
49 #include "hard-reg-set.h"
50 #include "insn-config.h"
53 #include "basic-block.h"
58 #include "integrate.h"
59 #include "langhooks.h"
61 #include "cfglayout.h"
63 #include "tree-pass.h"
69 /* So we can assign to cfun in this file. */
72 #ifndef STACK_ALIGNMENT_NEEDED
73 #define STACK_ALIGNMENT_NEEDED 1
76 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
78 /* Some systems use __main in a way incompatible with its use in gcc, in these
79 cases use the macros NAME__MAIN to give a quoted symbol and SYMBOL__MAIN to
80 give the same symbol without quotes for an alternative entry point. You
81 must define both, or neither. */
83 #define NAME__MAIN "__main"
86 /* Round a value to the lowest integer less than it that is a multiple of
87 the required alignment. Avoid using division in case the value is
88 negative. Assume the alignment is a power of two. */
89 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
91 /* Similar, but round to the next highest integer that meets the
93 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
95 /* Nonzero if function being compiled doesn't contain any calls
96 (ignoring the prologue and epilogue). This is set prior to
97 local register allocation and is valid for the remaining
99 int current_function_is_leaf;
101 /* Nonzero if function being compiled doesn't modify the stack pointer
102 (ignoring the prologue and epilogue). This is only valid after
103 pass_stack_ptr_mod has run. */
104 int current_function_sp_is_unchanging;
106 /* Nonzero if the function being compiled is a leaf function which only
107 uses leaf registers. This is valid after reload (specifically after
108 sched2) and is useful only if the port defines LEAF_REGISTERS. */
109 int current_function_uses_only_leaf_regs;
111 /* Nonzero once virtual register instantiation has been done.
112 assign_stack_local uses frame_pointer_rtx when this is nonzero.
113 calls.c:emit_library_call_value_1 uses it to set up
114 post-instantiation libcalls. */
115 int virtuals_instantiated;
117 /* Assign unique numbers to labels generated for profiling, debugging, etc. */
118 static GTY(()) int funcdef_no;
120 /* These variables hold pointers to functions to create and destroy
121 target specific, per-function data structures. */
122 struct machine_function * (*init_machine_status) (void);
124 /* The currently compiled function. */
125 struct function *cfun = 0;
127 /* These hashes record the prologue and epilogue insns. */
128 static GTY((if_marked ("ggc_marked_p"), param_is (struct rtx_def)))
129 htab_t prologue_insn_hash;
130 static GTY((if_marked ("ggc_marked_p"), param_is (struct rtx_def)))
131 htab_t epilogue_insn_hash;
133 /* Forward declarations. */
135 static struct temp_slot *find_temp_slot_from_address (rtx);
136 static void pad_to_arg_alignment (struct args_size *, int, struct args_size *);
137 static void pad_below (struct args_size *, enum machine_mode, tree);
138 static void reorder_blocks_1 (rtx, tree, VEC(tree,heap) **);
139 static int all_blocks (tree, tree *);
140 static tree *get_block_vector (tree, int *);
141 extern tree debug_find_var_in_block_tree (tree, tree);
142 /* We always define `record_insns' even if it's not used so that we
143 can always export `prologue_epilogue_contains'. */
144 static void record_insns (rtx, rtx, htab_t *) ATTRIBUTE_UNUSED;
145 static bool contains (const_rtx, htab_t);
147 static void emit_return_into_block (basic_block);
149 static void prepare_function_start (void);
150 static void do_clobber_return_reg (rtx, void *);
151 static void do_use_return_reg (rtx, void *);
152 static void set_insn_locators (rtx, int) ATTRIBUTE_UNUSED;
154 /* Stack of nested functions. */
155 /* Keep track of the cfun stack. */
157 typedef struct function *function_p;
159 DEF_VEC_P(function_p);
160 DEF_VEC_ALLOC_P(function_p,heap);
161 static VEC(function_p,heap) *function_context_stack;
163 /* Save the current context for compilation of a nested function.
164 This is called from language-specific code. */
167 push_function_context (void)
170 allocate_struct_function (NULL, false);
172 VEC_safe_push (function_p, heap, function_context_stack, cfun);
176 /* Restore the last saved context, at the end of a nested function.
177 This function is called from language-specific code. */
180 pop_function_context (void)
182 struct function *p = VEC_pop (function_p, function_context_stack);
184 current_function_decl = p->decl;
186 /* Reset variables that have known state during rtx generation. */
187 virtuals_instantiated = 0;
188 generating_concat_p = 1;
191 /* Clear out all parts of the state in F that can safely be discarded
192 after the function has been parsed, but not compiled, to let
193 garbage collection reclaim the memory. */
196 free_after_parsing (struct function *f)
201 /* Clear out all parts of the state in F that can safely be discarded
202 after the function has been compiled, to let garbage collection
203 reclaim the memory. */
206 free_after_compilation (struct function *f)
208 prologue_insn_hash = NULL;
209 epilogue_insn_hash = NULL;
211 if (crtl->emit.regno_pointer_align)
212 free (crtl->emit.regno_pointer_align);
214 memset (crtl, 0, sizeof (struct rtl_data));
219 regno_reg_rtx = NULL;
220 insn_locators_free ();
223 /* Return size needed for stack frame based on slots so far allocated.
224 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
225 the caller may have to do that. */
228 get_frame_size (void)
230 if (FRAME_GROWS_DOWNWARD)
231 return -frame_offset;
236 /* Issue an error message and return TRUE if frame OFFSET overflows in
237 the signed target pointer arithmetics for function FUNC. Otherwise
241 frame_offset_overflow (HOST_WIDE_INT offset, tree func)
243 unsigned HOST_WIDE_INT size = FRAME_GROWS_DOWNWARD ? -offset : offset;
245 if (size > ((unsigned HOST_WIDE_INT) 1 << (GET_MODE_BITSIZE (Pmode) - 1))
246 /* Leave room for the fixed part of the frame. */
247 - 64 * UNITS_PER_WORD)
249 error_at (DECL_SOURCE_LOCATION (func),
250 "total size of local objects too large");
257 /* Return stack slot alignment in bits for TYPE and MODE. */
260 get_stack_local_alignment (tree type, enum machine_mode mode)
262 unsigned int alignment;
265 alignment = BIGGEST_ALIGNMENT;
267 alignment = GET_MODE_ALIGNMENT (mode);
269 /* Allow the frond-end to (possibly) increase the alignment of this
272 type = lang_hooks.types.type_for_mode (mode, 0);
274 return STACK_SLOT_ALIGNMENT (type, mode, alignment);
277 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
278 with machine mode MODE.
280 ALIGN controls the amount of alignment for the address of the slot:
281 0 means according to MODE,
282 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
283 -2 means use BITS_PER_UNIT,
284 positive specifies alignment boundary in bits.
286 If REDUCE_ALIGNMENT_OK is true, it is OK to reduce alignment.
288 We do not round to stack_boundary here. */
291 assign_stack_local_1 (enum machine_mode mode, HOST_WIDE_INT size,
293 bool reduce_alignment_ok ATTRIBUTE_UNUSED)
296 int bigend_correction = 0;
297 unsigned int alignment, alignment_in_bits;
298 int frame_off, frame_alignment, frame_phase;
302 alignment = get_stack_local_alignment (NULL, mode);
303 alignment /= BITS_PER_UNIT;
305 else if (align == -1)
307 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
308 size = CEIL_ROUND (size, alignment);
310 else if (align == -2)
311 alignment = 1; /* BITS_PER_UNIT / BITS_PER_UNIT */
313 alignment = align / BITS_PER_UNIT;
315 alignment_in_bits = alignment * BITS_PER_UNIT;
317 if (FRAME_GROWS_DOWNWARD)
318 frame_offset -= size;
320 /* Ignore alignment if it exceeds MAX_SUPPORTED_STACK_ALIGNMENT. */
321 if (alignment_in_bits > MAX_SUPPORTED_STACK_ALIGNMENT)
323 alignment_in_bits = MAX_SUPPORTED_STACK_ALIGNMENT;
324 alignment = alignment_in_bits / BITS_PER_UNIT;
327 if (SUPPORTS_STACK_ALIGNMENT)
329 if (crtl->stack_alignment_estimated < alignment_in_bits)
331 if (!crtl->stack_realign_processed)
332 crtl->stack_alignment_estimated = alignment_in_bits;
335 /* If stack is realigned and stack alignment value
336 hasn't been finalized, it is OK not to increase
337 stack_alignment_estimated. The bigger alignment
338 requirement is recorded in stack_alignment_needed
340 gcc_assert (!crtl->stack_realign_finalized);
341 if (!crtl->stack_realign_needed)
343 /* It is OK to reduce the alignment as long as the
344 requested size is 0 or the estimated stack
345 alignment >= mode alignment. */
346 gcc_assert (reduce_alignment_ok
348 || (crtl->stack_alignment_estimated
349 >= GET_MODE_ALIGNMENT (mode)));
350 alignment_in_bits = crtl->stack_alignment_estimated;
351 alignment = alignment_in_bits / BITS_PER_UNIT;
357 if (crtl->stack_alignment_needed < alignment_in_bits)
358 crtl->stack_alignment_needed = alignment_in_bits;
359 if (crtl->max_used_stack_slot_alignment < alignment_in_bits)
360 crtl->max_used_stack_slot_alignment = alignment_in_bits;
362 /* Calculate how many bytes the start of local variables is off from
364 frame_alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
365 frame_off = STARTING_FRAME_OFFSET % frame_alignment;
366 frame_phase = frame_off ? frame_alignment - frame_off : 0;
368 /* Round the frame offset to the specified alignment. The default is
369 to always honor requests to align the stack but a port may choose to
370 do its own stack alignment by defining STACK_ALIGNMENT_NEEDED. */
371 if (STACK_ALIGNMENT_NEEDED
375 /* We must be careful here, since FRAME_OFFSET might be negative and
376 division with a negative dividend isn't as well defined as we might
377 like. So we instead assume that ALIGNMENT is a power of two and
378 use logical operations which are unambiguous. */
379 if (FRAME_GROWS_DOWNWARD)
381 = (FLOOR_ROUND (frame_offset - frame_phase,
382 (unsigned HOST_WIDE_INT) alignment)
386 = (CEIL_ROUND (frame_offset - frame_phase,
387 (unsigned HOST_WIDE_INT) alignment)
391 /* On a big-endian machine, if we are allocating more space than we will use,
392 use the least significant bytes of those that are allocated. */
393 if (BYTES_BIG_ENDIAN && mode != BLKmode && GET_MODE_SIZE (mode) < size)
394 bigend_correction = size - GET_MODE_SIZE (mode);
396 /* If we have already instantiated virtual registers, return the actual
397 address relative to the frame pointer. */
398 if (virtuals_instantiated)
399 addr = plus_constant (frame_pointer_rtx,
401 (frame_offset + bigend_correction
402 + STARTING_FRAME_OFFSET, Pmode));
404 addr = plus_constant (virtual_stack_vars_rtx,
406 (frame_offset + bigend_correction,
409 if (!FRAME_GROWS_DOWNWARD)
410 frame_offset += size;
412 x = gen_rtx_MEM (mode, addr);
413 set_mem_align (x, alignment_in_bits);
414 MEM_NOTRAP_P (x) = 1;
417 = gen_rtx_EXPR_LIST (VOIDmode, x, stack_slot_list);
419 if (frame_offset_overflow (frame_offset, current_function_decl))
425 /* Wrap up assign_stack_local_1 with last parameter as false. */
428 assign_stack_local (enum machine_mode mode, HOST_WIDE_INT size, int align)
430 return assign_stack_local_1 (mode, size, align, false);
434 /* In order to evaluate some expressions, such as function calls returning
435 structures in memory, we need to temporarily allocate stack locations.
436 We record each allocated temporary in the following structure.
438 Associated with each temporary slot is a nesting level. When we pop up
439 one level, all temporaries associated with the previous level are freed.
440 Normally, all temporaries are freed after the execution of the statement
441 in which they were created. However, if we are inside a ({...}) grouping,
442 the result may be in a temporary and hence must be preserved. If the
443 result could be in a temporary, we preserve it if we can determine which
444 one it is in. If we cannot determine which temporary may contain the
445 result, all temporaries are preserved. A temporary is preserved by
446 pretending it was allocated at the previous nesting level.
448 Automatic variables are also assigned temporary slots, at the nesting
449 level where they are defined. They are marked a "kept" so that
450 free_temp_slots will not free them. */
452 struct GTY(()) temp_slot {
453 /* Points to next temporary slot. */
454 struct temp_slot *next;
455 /* Points to previous temporary slot. */
456 struct temp_slot *prev;
457 /* The rtx to used to reference the slot. */
459 /* The size, in units, of the slot. */
461 /* The type of the object in the slot, or zero if it doesn't correspond
462 to a type. We use this to determine whether a slot can be reused.
463 It can be reused if objects of the type of the new slot will always
464 conflict with objects of the type of the old slot. */
466 /* The alignment (in bits) of the slot. */
468 /* Nonzero if this temporary is currently in use. */
470 /* Nonzero if this temporary has its address taken. */
472 /* Nesting level at which this slot is being used. */
474 /* Nonzero if this should survive a call to free_temp_slots. */
476 /* The offset of the slot from the frame_pointer, including extra space
477 for alignment. This info is for combine_temp_slots. */
478 HOST_WIDE_INT base_offset;
479 /* The size of the slot, including extra space for alignment. This
480 info is for combine_temp_slots. */
481 HOST_WIDE_INT full_size;
484 /* A table of addresses that represent a stack slot. The table is a mapping
485 from address RTXen to a temp slot. */
486 static GTY((param_is(struct temp_slot_address_entry))) htab_t temp_slot_address_table;
488 /* Entry for the above hash table. */
489 struct GTY(()) temp_slot_address_entry {
492 struct temp_slot *temp_slot;
495 /* Removes temporary slot TEMP from LIST. */
498 cut_slot_from_list (struct temp_slot *temp, struct temp_slot **list)
501 temp->next->prev = temp->prev;
503 temp->prev->next = temp->next;
507 temp->prev = temp->next = NULL;
510 /* Inserts temporary slot TEMP to LIST. */
513 insert_slot_to_list (struct temp_slot *temp, struct temp_slot **list)
517 (*list)->prev = temp;
522 /* Returns the list of used temp slots at LEVEL. */
524 static struct temp_slot **
525 temp_slots_at_level (int level)
527 if (level >= (int) VEC_length (temp_slot_p, used_temp_slots))
528 VEC_safe_grow_cleared (temp_slot_p, gc, used_temp_slots, level + 1);
530 return &(VEC_address (temp_slot_p, used_temp_slots)[level]);
533 /* Returns the maximal temporary slot level. */
536 max_slot_level (void)
538 if (!used_temp_slots)
541 return VEC_length (temp_slot_p, used_temp_slots) - 1;
544 /* Moves temporary slot TEMP to LEVEL. */
547 move_slot_to_level (struct temp_slot *temp, int level)
549 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
550 insert_slot_to_list (temp, temp_slots_at_level (level));
554 /* Make temporary slot TEMP available. */
557 make_slot_available (struct temp_slot *temp)
559 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
560 insert_slot_to_list (temp, &avail_temp_slots);
565 /* Compute the hash value for an address -> temp slot mapping.
566 The value is cached on the mapping entry. */
568 temp_slot_address_compute_hash (struct temp_slot_address_entry *t)
570 int do_not_record = 0;
571 return hash_rtx (t->address, GET_MODE (t->address),
572 &do_not_record, NULL, false);
575 /* Return the hash value for an address -> temp slot mapping. */
577 temp_slot_address_hash (const void *p)
579 const struct temp_slot_address_entry *t;
580 t = (const struct temp_slot_address_entry *) p;
584 /* Compare two address -> temp slot mapping entries. */
586 temp_slot_address_eq (const void *p1, const void *p2)
588 const struct temp_slot_address_entry *t1, *t2;
589 t1 = (const struct temp_slot_address_entry *) p1;
590 t2 = (const struct temp_slot_address_entry *) p2;
591 return exp_equiv_p (t1->address, t2->address, 0, true);
594 /* Add ADDRESS as an alias of TEMP_SLOT to the addess -> temp slot mapping. */
596 insert_temp_slot_address (rtx address, struct temp_slot *temp_slot)
599 struct temp_slot_address_entry *t = GGC_NEW (struct temp_slot_address_entry);
600 t->address = address;
601 t->temp_slot = temp_slot;
602 t->hash = temp_slot_address_compute_hash (t);
603 slot = htab_find_slot_with_hash (temp_slot_address_table, t, t->hash, INSERT);
607 /* Remove an address -> temp slot mapping entry if the temp slot is
608 not in use anymore. Callback for remove_unused_temp_slot_addresses. */
610 remove_unused_temp_slot_addresses_1 (void **slot, void *data ATTRIBUTE_UNUSED)
612 const struct temp_slot_address_entry *t;
613 t = (const struct temp_slot_address_entry *) *slot;
614 if (! t->temp_slot->in_use)
619 /* Remove all mappings of addresses to unused temp slots. */
621 remove_unused_temp_slot_addresses (void)
623 htab_traverse (temp_slot_address_table,
624 remove_unused_temp_slot_addresses_1,
628 /* Find the temp slot corresponding to the object at address X. */
630 static struct temp_slot *
631 find_temp_slot_from_address (rtx x)
634 struct temp_slot_address_entry tmp, *t;
636 /* First try the easy way:
637 See if X exists in the address -> temp slot mapping. */
639 tmp.temp_slot = NULL;
640 tmp.hash = temp_slot_address_compute_hash (&tmp);
641 t = (struct temp_slot_address_entry *)
642 htab_find_with_hash (temp_slot_address_table, &tmp, tmp.hash);
646 /* If we have a sum involving a register, see if it points to a temp
648 if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 0))
649 && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
651 else if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 1))
652 && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
655 /* Last resort: Address is a virtual stack var address. */
656 if (GET_CODE (x) == PLUS
657 && XEXP (x, 0) == virtual_stack_vars_rtx
658 && CONST_INT_P (XEXP (x, 1)))
661 for (i = max_slot_level (); i >= 0; i--)
662 for (p = *temp_slots_at_level (i); p; p = p->next)
664 if (INTVAL (XEXP (x, 1)) >= p->base_offset
665 && INTVAL (XEXP (x, 1)) < p->base_offset + p->full_size)
673 /* Allocate a temporary stack slot and record it for possible later
676 MODE is the machine mode to be given to the returned rtx.
678 SIZE is the size in units of the space required. We do no rounding here
679 since assign_stack_local will do any required rounding.
681 KEEP is 1 if this slot is to be retained after a call to
682 free_temp_slots. Automatic variables for a block are allocated
683 with this flag. KEEP values of 2 or 3 were needed respectively
684 for variables whose lifetime is controlled by CLEANUP_POINT_EXPRs
685 or for SAVE_EXPRs, but they are now unused.
687 TYPE is the type that will be used for the stack slot. */
690 assign_stack_temp_for_type (enum machine_mode mode, HOST_WIDE_INT size,
694 struct temp_slot *p, *best_p = 0, *selected = NULL, **pp;
697 /* If SIZE is -1 it means that somebody tried to allocate a temporary
698 of a variable size. */
699 gcc_assert (size != -1);
701 /* These are now unused. */
702 gcc_assert (keep <= 1);
704 align = get_stack_local_alignment (type, mode);
706 /* Try to find an available, already-allocated temporary of the proper
707 mode which meets the size and alignment requirements. Choose the
708 smallest one with the closest alignment.
710 If assign_stack_temp is called outside of the tree->rtl expansion,
711 we cannot reuse the stack slots (that may still refer to
712 VIRTUAL_STACK_VARS_REGNUM). */
713 if (!virtuals_instantiated)
715 for (p = avail_temp_slots; p; p = p->next)
717 if (p->align >= align && p->size >= size
718 && GET_MODE (p->slot) == mode
719 && objects_must_conflict_p (p->type, type)
720 && (best_p == 0 || best_p->size > p->size
721 || (best_p->size == p->size && best_p->align > p->align)))
723 if (p->align == align && p->size == size)
726 cut_slot_from_list (selected, &avail_temp_slots);
735 /* Make our best, if any, the one to use. */
739 cut_slot_from_list (selected, &avail_temp_slots);
741 /* If there are enough aligned bytes left over, make them into a new
742 temp_slot so that the extra bytes don't get wasted. Do this only
743 for BLKmode slots, so that we can be sure of the alignment. */
744 if (GET_MODE (best_p->slot) == BLKmode)
746 int alignment = best_p->align / BITS_PER_UNIT;
747 HOST_WIDE_INT rounded_size = CEIL_ROUND (size, alignment);
749 if (best_p->size - rounded_size >= alignment)
751 p = GGC_NEW (struct temp_slot);
752 p->in_use = p->addr_taken = 0;
753 p->size = best_p->size - rounded_size;
754 p->base_offset = best_p->base_offset + rounded_size;
755 p->full_size = best_p->full_size - rounded_size;
756 p->slot = adjust_address_nv (best_p->slot, BLKmode, rounded_size);
757 p->align = best_p->align;
758 p->type = best_p->type;
759 insert_slot_to_list (p, &avail_temp_slots);
761 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, p->slot,
764 best_p->size = rounded_size;
765 best_p->full_size = rounded_size;
770 /* If we still didn't find one, make a new temporary. */
773 HOST_WIDE_INT frame_offset_old = frame_offset;
775 p = GGC_NEW (struct temp_slot);
777 /* We are passing an explicit alignment request to assign_stack_local.
778 One side effect of that is assign_stack_local will not round SIZE
779 to ensure the frame offset remains suitably aligned.
781 So for requests which depended on the rounding of SIZE, we go ahead
782 and round it now. We also make sure ALIGNMENT is at least
783 BIGGEST_ALIGNMENT. */
784 gcc_assert (mode != BLKmode || align == BIGGEST_ALIGNMENT);
785 p->slot = assign_stack_local (mode,
787 ? CEIL_ROUND (size, (int) align / BITS_PER_UNIT)
793 /* The following slot size computation is necessary because we don't
794 know the actual size of the temporary slot until assign_stack_local
795 has performed all the frame alignment and size rounding for the
796 requested temporary. Note that extra space added for alignment
797 can be either above or below this stack slot depending on which
798 way the frame grows. We include the extra space if and only if it
799 is above this slot. */
800 if (FRAME_GROWS_DOWNWARD)
801 p->size = frame_offset_old - frame_offset;
805 /* Now define the fields used by combine_temp_slots. */
806 if (FRAME_GROWS_DOWNWARD)
808 p->base_offset = frame_offset;
809 p->full_size = frame_offset_old - frame_offset;
813 p->base_offset = frame_offset_old;
814 p->full_size = frame_offset - frame_offset_old;
824 p->level = temp_slot_level;
827 pp = temp_slots_at_level (p->level);
828 insert_slot_to_list (p, pp);
829 insert_temp_slot_address (XEXP (p->slot, 0), p);
831 /* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
832 slot = gen_rtx_MEM (mode, XEXP (p->slot, 0));
833 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, slot, stack_slot_list);
835 /* If we know the alias set for the memory that will be used, use
836 it. If there's no TYPE, then we don't know anything about the
837 alias set for the memory. */
838 set_mem_alias_set (slot, type ? get_alias_set (type) : 0);
839 set_mem_align (slot, align);
841 /* If a type is specified, set the relevant flags. */
844 MEM_VOLATILE_P (slot) = TYPE_VOLATILE (type);
845 MEM_SET_IN_STRUCT_P (slot, (AGGREGATE_TYPE_P (type)
846 || TREE_CODE (type) == COMPLEX_TYPE));
848 MEM_NOTRAP_P (slot) = 1;
853 /* Allocate a temporary stack slot and record it for possible later
854 reuse. First three arguments are same as in preceding function. */
857 assign_stack_temp (enum machine_mode mode, HOST_WIDE_INT size, int keep)
859 return assign_stack_temp_for_type (mode, size, keep, NULL_TREE);
862 /* Assign a temporary.
863 If TYPE_OR_DECL is a decl, then we are doing it on behalf of the decl
864 and so that should be used in error messages. In either case, we
865 allocate of the given type.
866 KEEP is as for assign_stack_temp.
867 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
868 it is 0 if a register is OK.
869 DONT_PROMOTE is 1 if we should not promote values in register
873 assign_temp (tree type_or_decl, int keep, int memory_required,
874 int dont_promote ATTRIBUTE_UNUSED)
877 enum machine_mode mode;
882 if (DECL_P (type_or_decl))
883 decl = type_or_decl, type = TREE_TYPE (decl);
885 decl = NULL, type = type_or_decl;
887 mode = TYPE_MODE (type);
889 unsignedp = TYPE_UNSIGNED (type);
892 if (mode == BLKmode || memory_required)
894 HOST_WIDE_INT size = int_size_in_bytes (type);
897 /* Zero sized arrays are GNU C extension. Set size to 1 to avoid
898 problems with allocating the stack space. */
902 /* Unfortunately, we don't yet know how to allocate variable-sized
903 temporaries. However, sometimes we can find a fixed upper limit on
904 the size, so try that instead. */
906 size = max_int_size_in_bytes (type);
908 /* The size of the temporary may be too large to fit into an integer. */
909 /* ??? Not sure this should happen except for user silliness, so limit
910 this to things that aren't compiler-generated temporaries. The
911 rest of the time we'll die in assign_stack_temp_for_type. */
912 if (decl && size == -1
913 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST)
915 error ("size of variable %q+D is too large", decl);
919 tmp = assign_stack_temp_for_type (mode, size, keep, type);
925 mode = promote_mode (type, mode, &unsignedp);
928 return gen_reg_rtx (mode);
931 /* Combine temporary stack slots which are adjacent on the stack.
933 This allows for better use of already allocated stack space. This is only
934 done for BLKmode slots because we can be sure that we won't have alignment
935 problems in this case. */
938 combine_temp_slots (void)
940 struct temp_slot *p, *q, *next, *next_q;
943 /* We can't combine slots, because the information about which slot
944 is in which alias set will be lost. */
945 if (flag_strict_aliasing)
948 /* If there are a lot of temp slots, don't do anything unless
949 high levels of optimization. */
950 if (! flag_expensive_optimizations)
951 for (p = avail_temp_slots, num_slots = 0; p; p = p->next, num_slots++)
952 if (num_slots > 100 || (num_slots > 10 && optimize == 0))
955 for (p = avail_temp_slots; p; p = next)
961 if (GET_MODE (p->slot) != BLKmode)
964 for (q = p->next; q; q = next_q)
970 if (GET_MODE (q->slot) != BLKmode)
973 if (p->base_offset + p->full_size == q->base_offset)
975 /* Q comes after P; combine Q into P. */
977 p->full_size += q->full_size;
980 else if (q->base_offset + q->full_size == p->base_offset)
982 /* P comes after Q; combine P into Q. */
984 q->full_size += p->full_size;
989 cut_slot_from_list (q, &avail_temp_slots);
992 /* Either delete P or advance past it. */
994 cut_slot_from_list (p, &avail_temp_slots);
998 /* Indicate that NEW_RTX is an alternate way of referring to the temp
999 slot that previously was known by OLD_RTX. */
1002 update_temp_slot_address (rtx old_rtx, rtx new_rtx)
1004 struct temp_slot *p;
1006 if (rtx_equal_p (old_rtx, new_rtx))
1009 p = find_temp_slot_from_address (old_rtx);
1011 /* If we didn't find one, see if both OLD_RTX is a PLUS. If so, and
1012 NEW_RTX is a register, see if one operand of the PLUS is a
1013 temporary location. If so, NEW_RTX points into it. Otherwise,
1014 if both OLD_RTX and NEW_RTX are a PLUS and if there is a register
1015 in common between them. If so, try a recursive call on those
1019 if (GET_CODE (old_rtx) != PLUS)
1022 if (REG_P (new_rtx))
1024 update_temp_slot_address (XEXP (old_rtx, 0), new_rtx);
1025 update_temp_slot_address (XEXP (old_rtx, 1), new_rtx);
1028 else if (GET_CODE (new_rtx) != PLUS)
1031 if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 0)))
1032 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 1));
1033 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 0)))
1034 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 1));
1035 else if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 1)))
1036 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 0));
1037 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 1)))
1038 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 0));
1043 /* Otherwise add an alias for the temp's address. */
1044 insert_temp_slot_address (new_rtx, p);
1047 /* If X could be a reference to a temporary slot, mark the fact that its
1048 address was taken. */
1051 mark_temp_addr_taken (rtx x)
1053 struct temp_slot *p;
1058 /* If X is not in memory or is at a constant address, it cannot be in
1059 a temporary slot. */
1060 if (!MEM_P (x) || CONSTANT_P (XEXP (x, 0)))
1063 p = find_temp_slot_from_address (XEXP (x, 0));
1068 /* If X could be a reference to a temporary slot, mark that slot as
1069 belonging to the to one level higher than the current level. If X
1070 matched one of our slots, just mark that one. Otherwise, we can't
1071 easily predict which it is, so upgrade all of them. Kept slots
1072 need not be touched.
1074 This is called when an ({...}) construct occurs and a statement
1075 returns a value in memory. */
1078 preserve_temp_slots (rtx x)
1080 struct temp_slot *p = 0, *next;
1082 /* If there is no result, we still might have some objects whose address
1083 were taken, so we need to make sure they stay around. */
1086 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1091 move_slot_to_level (p, temp_slot_level - 1);
1097 /* If X is a register that is being used as a pointer, see if we have
1098 a temporary slot we know it points to. To be consistent with
1099 the code below, we really should preserve all non-kept slots
1100 if we can't find a match, but that seems to be much too costly. */
1101 if (REG_P (x) && REG_POINTER (x))
1102 p = find_temp_slot_from_address (x);
1104 /* If X is not in memory or is at a constant address, it cannot be in
1105 a temporary slot, but it can contain something whose address was
1107 if (p == 0 && (!MEM_P (x) || CONSTANT_P (XEXP (x, 0))))
1109 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1114 move_slot_to_level (p, temp_slot_level - 1);
1120 /* First see if we can find a match. */
1122 p = find_temp_slot_from_address (XEXP (x, 0));
1126 /* Move everything at our level whose address was taken to our new
1127 level in case we used its address. */
1128 struct temp_slot *q;
1130 if (p->level == temp_slot_level)
1132 for (q = *temp_slots_at_level (temp_slot_level); q; q = next)
1136 if (p != q && q->addr_taken)
1137 move_slot_to_level (q, temp_slot_level - 1);
1140 move_slot_to_level (p, temp_slot_level - 1);
1146 /* Otherwise, preserve all non-kept slots at this level. */
1147 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1152 move_slot_to_level (p, temp_slot_level - 1);
1156 /* Free all temporaries used so far. This is normally called at the
1157 end of generating code for a statement. */
1160 free_temp_slots (void)
1162 struct temp_slot *p, *next;
1164 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1169 make_slot_available (p);
1172 remove_unused_temp_slot_addresses ();
1173 combine_temp_slots ();
1176 /* Push deeper into the nesting level for stack temporaries. */
1179 push_temp_slots (void)
1184 /* Pop a temporary nesting level. All slots in use in the current level
1188 pop_temp_slots (void)
1190 struct temp_slot *p, *next;
1192 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1195 make_slot_available (p);
1198 remove_unused_temp_slot_addresses ();
1199 combine_temp_slots ();
1204 /* Initialize temporary slots. */
1207 init_temp_slots (void)
1209 /* We have not allocated any temporaries yet. */
1210 avail_temp_slots = 0;
1211 used_temp_slots = 0;
1212 temp_slot_level = 0;
1214 /* Set up the table to map addresses to temp slots. */
1215 if (! temp_slot_address_table)
1216 temp_slot_address_table = htab_create_ggc (32,
1217 temp_slot_address_hash,
1218 temp_slot_address_eq,
1221 htab_empty (temp_slot_address_table);
1224 /* These routines are responsible for converting virtual register references
1225 to the actual hard register references once RTL generation is complete.
1227 The following four variables are used for communication between the
1228 routines. They contain the offsets of the virtual registers from their
1229 respective hard registers. */
1231 static int in_arg_offset;
1232 static int var_offset;
1233 static int dynamic_offset;
1234 static int out_arg_offset;
1235 static int cfa_offset;
1237 /* In most machines, the stack pointer register is equivalent to the bottom
1240 #ifndef STACK_POINTER_OFFSET
1241 #define STACK_POINTER_OFFSET 0
1244 /* If not defined, pick an appropriate default for the offset of dynamically
1245 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
1246 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
1248 #ifndef STACK_DYNAMIC_OFFSET
1250 /* The bottom of the stack points to the actual arguments. If
1251 REG_PARM_STACK_SPACE is defined, this includes the space for the register
1252 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
1253 stack space for register parameters is not pushed by the caller, but
1254 rather part of the fixed stack areas and hence not included in
1255 `crtl->outgoing_args_size'. Nevertheless, we must allow
1256 for it when allocating stack dynamic objects. */
1258 #if defined(REG_PARM_STACK_SPACE)
1259 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1260 ((ACCUMULATE_OUTGOING_ARGS \
1261 ? (crtl->outgoing_args_size \
1262 + (OUTGOING_REG_PARM_STACK_SPACE ((!(FNDECL) ? NULL_TREE : TREE_TYPE (FNDECL))) ? 0 \
1263 : REG_PARM_STACK_SPACE (FNDECL))) \
1264 : 0) + (STACK_POINTER_OFFSET))
1266 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1267 ((ACCUMULATE_OUTGOING_ARGS ? crtl->outgoing_args_size : 0) \
1268 + (STACK_POINTER_OFFSET))
1273 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
1274 is a virtual register, return the equivalent hard register and set the
1275 offset indirectly through the pointer. Otherwise, return 0. */
1278 instantiate_new_reg (rtx x, HOST_WIDE_INT *poffset)
1281 HOST_WIDE_INT offset;
1283 if (x == virtual_incoming_args_rtx)
1285 if (stack_realign_drap)
1287 /* Replace virtual_incoming_args_rtx with internal arg
1288 pointer if DRAP is used to realign stack. */
1289 new_rtx = crtl->args.internal_arg_pointer;
1293 new_rtx = arg_pointer_rtx, offset = in_arg_offset;
1295 else if (x == virtual_stack_vars_rtx)
1296 new_rtx = frame_pointer_rtx, offset = var_offset;
1297 else if (x == virtual_stack_dynamic_rtx)
1298 new_rtx = stack_pointer_rtx, offset = dynamic_offset;
1299 else if (x == virtual_outgoing_args_rtx)
1300 new_rtx = stack_pointer_rtx, offset = out_arg_offset;
1301 else if (x == virtual_cfa_rtx)
1303 #ifdef FRAME_POINTER_CFA_OFFSET
1304 new_rtx = frame_pointer_rtx;
1306 new_rtx = arg_pointer_rtx;
1308 offset = cfa_offset;
1317 /* A subroutine of instantiate_virtual_regs, called via for_each_rtx.
1318 Instantiate any virtual registers present inside of *LOC. The expression
1319 is simplified, as much as possible, but is not to be considered "valid"
1320 in any sense implied by the target. If any change is made, set CHANGED
1324 instantiate_virtual_regs_in_rtx (rtx *loc, void *data)
1326 HOST_WIDE_INT offset;
1327 bool *changed = (bool *) data;
1334 switch (GET_CODE (x))
1337 new_rtx = instantiate_new_reg (x, &offset);
1340 *loc = plus_constant (new_rtx, offset);
1347 new_rtx = instantiate_new_reg (XEXP (x, 0), &offset);
1350 new_rtx = plus_constant (new_rtx, offset);
1351 *loc = simplify_gen_binary (PLUS, GET_MODE (x), new_rtx, XEXP (x, 1));
1357 /* FIXME -- from old code */
1358 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
1359 we can commute the PLUS and SUBREG because pointers into the
1360 frame are well-behaved. */
1370 /* A subroutine of instantiate_virtual_regs_in_insn. Return true if X
1371 matches the predicate for insn CODE operand OPERAND. */
1374 safe_insn_predicate (int code, int operand, rtx x)
1376 const struct insn_operand_data *op_data;
1381 op_data = &insn_data[code].operand[operand];
1382 if (op_data->predicate == NULL)
1385 return op_data->predicate (x, op_data->mode);
1388 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1389 registers present inside of insn. The result will be a valid insn. */
1392 instantiate_virtual_regs_in_insn (rtx insn)
1394 HOST_WIDE_INT offset;
1396 bool any_change = false;
1397 rtx set, new_rtx, x, seq;
1399 /* There are some special cases to be handled first. */
1400 set = single_set (insn);
1403 /* We're allowed to assign to a virtual register. This is interpreted
1404 to mean that the underlying register gets assigned the inverse
1405 transformation. This is used, for example, in the handling of
1407 new_rtx = instantiate_new_reg (SET_DEST (set), &offset);
1412 for_each_rtx (&SET_SRC (set), instantiate_virtual_regs_in_rtx, NULL);
1413 x = simplify_gen_binary (PLUS, GET_MODE (new_rtx), SET_SRC (set),
1415 x = force_operand (x, new_rtx);
1417 emit_move_insn (new_rtx, x);
1422 emit_insn_before (seq, insn);
1427 /* Handle a straight copy from a virtual register by generating a
1428 new add insn. The difference between this and falling through
1429 to the generic case is avoiding a new pseudo and eliminating a
1430 move insn in the initial rtl stream. */
1431 new_rtx = instantiate_new_reg (SET_SRC (set), &offset);
1432 if (new_rtx && offset != 0
1433 && REG_P (SET_DEST (set))
1434 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1438 x = expand_simple_binop (GET_MODE (SET_DEST (set)), PLUS,
1439 new_rtx, GEN_INT (offset), SET_DEST (set),
1440 1, OPTAB_LIB_WIDEN);
1441 if (x != SET_DEST (set))
1442 emit_move_insn (SET_DEST (set), x);
1447 emit_insn_before (seq, insn);
1452 extract_insn (insn);
1453 insn_code = INSN_CODE (insn);
1455 /* Handle a plus involving a virtual register by determining if the
1456 operands remain valid if they're modified in place. */
1457 if (GET_CODE (SET_SRC (set)) == PLUS
1458 && recog_data.n_operands >= 3
1459 && recog_data.operand_loc[1] == &XEXP (SET_SRC (set), 0)
1460 && recog_data.operand_loc[2] == &XEXP (SET_SRC (set), 1)
1461 && CONST_INT_P (recog_data.operand[2])
1462 && (new_rtx = instantiate_new_reg (recog_data.operand[1], &offset)))
1464 offset += INTVAL (recog_data.operand[2]);
1466 /* If the sum is zero, then replace with a plain move. */
1468 && REG_P (SET_DEST (set))
1469 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1472 emit_move_insn (SET_DEST (set), new_rtx);
1476 emit_insn_before (seq, insn);
1481 x = gen_int_mode (offset, recog_data.operand_mode[2]);
1483 /* Using validate_change and apply_change_group here leaves
1484 recog_data in an invalid state. Since we know exactly what
1485 we want to check, do those two by hand. */
1486 if (safe_insn_predicate (insn_code, 1, new_rtx)
1487 && safe_insn_predicate (insn_code, 2, x))
1489 *recog_data.operand_loc[1] = recog_data.operand[1] = new_rtx;
1490 *recog_data.operand_loc[2] = recog_data.operand[2] = x;
1493 /* Fall through into the regular operand fixup loop in
1494 order to take care of operands other than 1 and 2. */
1500 extract_insn (insn);
1501 insn_code = INSN_CODE (insn);
1504 /* In the general case, we expect virtual registers to appear only in
1505 operands, and then only as either bare registers or inside memories. */
1506 for (i = 0; i < recog_data.n_operands; ++i)
1508 x = recog_data.operand[i];
1509 switch (GET_CODE (x))
1513 rtx addr = XEXP (x, 0);
1514 bool changed = false;
1516 for_each_rtx (&addr, instantiate_virtual_regs_in_rtx, &changed);
1521 x = replace_equiv_address (x, addr);
1522 /* It may happen that the address with the virtual reg
1523 was valid (e.g. based on the virtual stack reg, which might
1524 be acceptable to the predicates with all offsets), whereas
1525 the address now isn't anymore, for instance when the address
1526 is still offsetted, but the base reg isn't virtual-stack-reg
1527 anymore. Below we would do a force_reg on the whole operand,
1528 but this insn might actually only accept memory. Hence,
1529 before doing that last resort, try to reload the address into
1530 a register, so this operand stays a MEM. */
1531 if (!safe_insn_predicate (insn_code, i, x))
1533 addr = force_reg (GET_MODE (addr), addr);
1534 x = replace_equiv_address (x, addr);
1539 emit_insn_before (seq, insn);
1544 new_rtx = instantiate_new_reg (x, &offset);
1545 if (new_rtx == NULL)
1553 /* Careful, special mode predicates may have stuff in
1554 insn_data[insn_code].operand[i].mode that isn't useful
1555 to us for computing a new value. */
1556 /* ??? Recognize address_operand and/or "p" constraints
1557 to see if (plus new offset) is a valid before we put
1558 this through expand_simple_binop. */
1559 x = expand_simple_binop (GET_MODE (x), PLUS, new_rtx,
1560 GEN_INT (offset), NULL_RTX,
1561 1, OPTAB_LIB_WIDEN);
1564 emit_insn_before (seq, insn);
1569 new_rtx = instantiate_new_reg (SUBREG_REG (x), &offset);
1570 if (new_rtx == NULL)
1575 new_rtx = expand_simple_binop (GET_MODE (new_rtx), PLUS, new_rtx,
1576 GEN_INT (offset), NULL_RTX,
1577 1, OPTAB_LIB_WIDEN);
1580 emit_insn_before (seq, insn);
1582 x = simplify_gen_subreg (recog_data.operand_mode[i], new_rtx,
1583 GET_MODE (new_rtx), SUBREG_BYTE (x));
1591 /* At this point, X contains the new value for the operand.
1592 Validate the new value vs the insn predicate. Note that
1593 asm insns will have insn_code -1 here. */
1594 if (!safe_insn_predicate (insn_code, i, x))
1597 x = force_reg (insn_data[insn_code].operand[i].mode, x);
1601 emit_insn_before (seq, insn);
1604 *recog_data.operand_loc[i] = recog_data.operand[i] = x;
1610 /* Propagate operand changes into the duplicates. */
1611 for (i = 0; i < recog_data.n_dups; ++i)
1612 *recog_data.dup_loc[i]
1613 = copy_rtx (recog_data.operand[(unsigned)recog_data.dup_num[i]]);
1615 /* Force re-recognition of the instruction for validation. */
1616 INSN_CODE (insn) = -1;
1619 if (asm_noperands (PATTERN (insn)) >= 0)
1621 if (!check_asm_operands (PATTERN (insn)))
1623 error_for_asm (insn, "impossible constraint in %<asm%>");
1629 if (recog_memoized (insn) < 0)
1630 fatal_insn_not_found (insn);
1634 /* Subroutine of instantiate_decls. Given RTL representing a decl,
1635 do any instantiation required. */
1638 instantiate_decl_rtl (rtx x)
1645 /* If this is a CONCAT, recurse for the pieces. */
1646 if (GET_CODE (x) == CONCAT)
1648 instantiate_decl_rtl (XEXP (x, 0));
1649 instantiate_decl_rtl (XEXP (x, 1));
1653 /* If this is not a MEM, no need to do anything. Similarly if the
1654 address is a constant or a register that is not a virtual register. */
1659 if (CONSTANT_P (addr)
1661 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
1662 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
1665 for_each_rtx (&XEXP (x, 0), instantiate_virtual_regs_in_rtx, NULL);
1668 /* Helper for instantiate_decls called via walk_tree: Process all decls
1669 in the given DECL_VALUE_EXPR. */
1672 instantiate_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1678 if (DECL_P (t) && DECL_RTL_SET_P (t))
1679 instantiate_decl_rtl (DECL_RTL (t));
1684 /* Subroutine of instantiate_decls: Process all decls in the given
1685 BLOCK node and all its subblocks. */
1688 instantiate_decls_1 (tree let)
1692 for (t = BLOCK_VARS (let); t; t = TREE_CHAIN (t))
1694 if (DECL_RTL_SET_P (t))
1695 instantiate_decl_rtl (DECL_RTL (t));
1696 if (TREE_CODE (t) == VAR_DECL && DECL_HAS_VALUE_EXPR_P (t))
1698 tree v = DECL_VALUE_EXPR (t);
1699 walk_tree (&v, instantiate_expr, NULL, NULL);
1703 /* Process all subblocks. */
1704 for (t = BLOCK_SUBBLOCKS (let); t; t = BLOCK_CHAIN (t))
1705 instantiate_decls_1 (t);
1708 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1709 all virtual registers in their DECL_RTL's. */
1712 instantiate_decls (tree fndecl)
1716 /* Process all parameters of the function. */
1717 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = TREE_CHAIN (decl))
1719 instantiate_decl_rtl (DECL_RTL (decl));
1720 instantiate_decl_rtl (DECL_INCOMING_RTL (decl));
1721 if (DECL_HAS_VALUE_EXPR_P (decl))
1723 tree v = DECL_VALUE_EXPR (decl);
1724 walk_tree (&v, instantiate_expr, NULL, NULL);
1728 /* Now process all variables defined in the function or its subblocks. */
1729 instantiate_decls_1 (DECL_INITIAL (fndecl));
1731 t = cfun->local_decls;
1732 cfun->local_decls = NULL_TREE;
1735 next = TREE_CHAIN (t);
1736 decl = TREE_VALUE (t);
1737 if (DECL_RTL_SET_P (decl))
1738 instantiate_decl_rtl (DECL_RTL (decl));
1743 /* Pass through the INSNS of function FNDECL and convert virtual register
1744 references to hard register references. */
1747 instantiate_virtual_regs (void)
1751 /* Compute the offsets to use for this function. */
1752 in_arg_offset = FIRST_PARM_OFFSET (current_function_decl);
1753 var_offset = STARTING_FRAME_OFFSET;
1754 dynamic_offset = STACK_DYNAMIC_OFFSET (current_function_decl);
1755 out_arg_offset = STACK_POINTER_OFFSET;
1756 #ifdef FRAME_POINTER_CFA_OFFSET
1757 cfa_offset = FRAME_POINTER_CFA_OFFSET (current_function_decl);
1759 cfa_offset = ARG_POINTER_CFA_OFFSET (current_function_decl);
1762 /* Initialize recognition, indicating that volatile is OK. */
1765 /* Scan through all the insns, instantiating every virtual register still
1767 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
1770 /* These patterns in the instruction stream can never be recognized.
1771 Fortunately, they shouldn't contain virtual registers either. */
1772 if (GET_CODE (PATTERN (insn)) == USE
1773 || GET_CODE (PATTERN (insn)) == CLOBBER
1774 || GET_CODE (PATTERN (insn)) == ADDR_VEC
1775 || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC
1776 || GET_CODE (PATTERN (insn)) == ASM_INPUT)
1778 else if (DEBUG_INSN_P (insn))
1779 for_each_rtx (&INSN_VAR_LOCATION (insn),
1780 instantiate_virtual_regs_in_rtx, NULL);
1782 instantiate_virtual_regs_in_insn (insn);
1784 if (INSN_DELETED_P (insn))
1787 for_each_rtx (®_NOTES (insn), instantiate_virtual_regs_in_rtx, NULL);
1789 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
1791 for_each_rtx (&CALL_INSN_FUNCTION_USAGE (insn),
1792 instantiate_virtual_regs_in_rtx, NULL);
1795 /* Instantiate the virtual registers in the DECLs for debugging purposes. */
1796 instantiate_decls (current_function_decl);
1798 targetm.instantiate_decls ();
1800 /* Indicate that, from now on, assign_stack_local should use
1801 frame_pointer_rtx. */
1802 virtuals_instantiated = 1;
1806 struct rtl_opt_pass pass_instantiate_virtual_regs =
1812 instantiate_virtual_regs, /* execute */
1815 0, /* static_pass_number */
1816 TV_NONE, /* tv_id */
1817 0, /* properties_required */
1818 0, /* properties_provided */
1819 0, /* properties_destroyed */
1820 0, /* todo_flags_start */
1821 TODO_dump_func /* todo_flags_finish */
1826 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
1827 This means a type for which function calls must pass an address to the
1828 function or get an address back from the function.
1829 EXP may be a type node or an expression (whose type is tested). */
1832 aggregate_value_p (const_tree exp, const_tree fntype)
1834 int i, regno, nregs;
1837 const_tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
1839 /* DECL node associated with FNTYPE when relevant, which we might need to
1840 check for by-invisible-reference returns, typically for CALL_EXPR input
1842 const_tree fndecl = NULL_TREE;
1845 switch (TREE_CODE (fntype))
1848 fndecl = get_callee_fndecl (fntype);
1850 ? TREE_TYPE (fndecl)
1851 : TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (fntype))));
1855 fntype = TREE_TYPE (fndecl);
1860 case IDENTIFIER_NODE:
1864 /* We don't expect other rtl types here. */
1868 if (TREE_CODE (type) == VOID_TYPE)
1871 /* If the front end has decided that this needs to be passed by
1872 reference, do so. */
1873 if ((TREE_CODE (exp) == PARM_DECL || TREE_CODE (exp) == RESULT_DECL)
1874 && DECL_BY_REFERENCE (exp))
1877 /* If the EXPression is a CALL_EXPR, honor DECL_BY_REFERENCE set on the
1878 called function RESULT_DECL, meaning the function returns in memory by
1879 invisible reference. This check lets front-ends not set TREE_ADDRESSABLE
1880 on the function type, which used to be the way to request such a return
1881 mechanism but might now be causing troubles at gimplification time if
1882 temporaries with the function type need to be created. */
1883 if (TREE_CODE (exp) == CALL_EXPR && fndecl && DECL_RESULT (fndecl)
1884 && DECL_BY_REFERENCE (DECL_RESULT (fndecl)))
1887 if (targetm.calls.return_in_memory (type, fntype))
1889 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
1890 and thus can't be returned in registers. */
1891 if (TREE_ADDRESSABLE (type))
1893 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
1895 /* Make sure we have suitable call-clobbered regs to return
1896 the value in; if not, we must return it in memory. */
1897 reg = hard_function_value (type, 0, fntype, 0);
1899 /* If we have something other than a REG (e.g. a PARALLEL), then assume
1904 regno = REGNO (reg);
1905 nregs = hard_regno_nregs[regno][TYPE_MODE (type)];
1906 for (i = 0; i < nregs; i++)
1907 if (! call_used_regs[regno + i])
1912 /* Return true if we should assign DECL a pseudo register; false if it
1913 should live on the local stack. */
1916 use_register_for_decl (const_tree decl)
1918 if (!targetm.calls.allocate_stack_slots_for_args())
1921 /* Honor volatile. */
1922 if (TREE_SIDE_EFFECTS (decl))
1925 /* Honor addressability. */
1926 if (TREE_ADDRESSABLE (decl))
1929 /* Only register-like things go in registers. */
1930 if (DECL_MODE (decl) == BLKmode)
1933 /* If -ffloat-store specified, don't put explicit float variables
1935 /* ??? This should be checked after DECL_ARTIFICIAL, but tree-ssa
1936 propagates values across these stores, and it probably shouldn't. */
1937 if (flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)))
1940 /* If we're not interested in tracking debugging information for
1941 this decl, then we can certainly put it in a register. */
1942 if (DECL_IGNORED_P (decl))
1948 if (!DECL_REGISTER (decl))
1951 switch (TREE_CODE (TREE_TYPE (decl)))
1955 case QUAL_UNION_TYPE:
1956 /* When not optimizing, disregard register keyword for variables with
1957 types containing methods, otherwise the methods won't be callable
1958 from the debugger. */
1959 if (TYPE_METHODS (TREE_TYPE (decl)))
1969 /* Return true if TYPE should be passed by invisible reference. */
1972 pass_by_reference (CUMULATIVE_ARGS *ca, enum machine_mode mode,
1973 tree type, bool named_arg)
1977 /* If this type contains non-trivial constructors, then it is
1978 forbidden for the middle-end to create any new copies. */
1979 if (TREE_ADDRESSABLE (type))
1982 /* GCC post 3.4 passes *all* variable sized types by reference. */
1983 if (!TYPE_SIZE (type) || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
1987 return targetm.calls.pass_by_reference (ca, mode, type, named_arg);
1990 /* Return true if TYPE, which is passed by reference, should be callee
1991 copied instead of caller copied. */
1994 reference_callee_copied (CUMULATIVE_ARGS *ca, enum machine_mode mode,
1995 tree type, bool named_arg)
1997 if (type && TREE_ADDRESSABLE (type))
1999 return targetm.calls.callee_copies (ca, mode, type, named_arg);
2002 /* Structures to communicate between the subroutines of assign_parms.
2003 The first holds data persistent across all parameters, the second
2004 is cleared out for each parameter. */
2006 struct assign_parm_data_all
2008 CUMULATIVE_ARGS args_so_far;
2009 struct args_size stack_args_size;
2010 tree function_result_decl;
2012 rtx first_conversion_insn;
2013 rtx last_conversion_insn;
2014 HOST_WIDE_INT pretend_args_size;
2015 HOST_WIDE_INT extra_pretend_bytes;
2016 int reg_parm_stack_space;
2019 struct assign_parm_data_one
2025 enum machine_mode nominal_mode;
2026 enum machine_mode passed_mode;
2027 enum machine_mode promoted_mode;
2028 struct locate_and_pad_arg_data locate;
2030 BOOL_BITFIELD named_arg : 1;
2031 BOOL_BITFIELD passed_pointer : 1;
2032 BOOL_BITFIELD on_stack : 1;
2033 BOOL_BITFIELD loaded_in_reg : 1;
2036 /* A subroutine of assign_parms. Initialize ALL. */
2039 assign_parms_initialize_all (struct assign_parm_data_all *all)
2043 memset (all, 0, sizeof (*all));
2045 fntype = TREE_TYPE (current_function_decl);
2047 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
2048 INIT_CUMULATIVE_INCOMING_ARGS (all->args_so_far, fntype, NULL_RTX);
2050 INIT_CUMULATIVE_ARGS (all->args_so_far, fntype, NULL_RTX,
2051 current_function_decl, -1);
2054 #ifdef REG_PARM_STACK_SPACE
2055 all->reg_parm_stack_space = REG_PARM_STACK_SPACE (current_function_decl);
2059 /* If ARGS contains entries with complex types, split the entry into two
2060 entries of the component type. Return a new list of substitutions are
2061 needed, else the old list. */
2064 split_complex_args (tree args)
2068 /* Before allocating memory, check for the common case of no complex. */
2069 for (p = args; p; p = TREE_CHAIN (p))
2071 tree type = TREE_TYPE (p);
2072 if (TREE_CODE (type) == COMPLEX_TYPE
2073 && targetm.calls.split_complex_arg (type))
2079 args = copy_list (args);
2081 for (p = args; p; p = TREE_CHAIN (p))
2083 tree type = TREE_TYPE (p);
2084 if (TREE_CODE (type) == COMPLEX_TYPE
2085 && targetm.calls.split_complex_arg (type))
2088 tree subtype = TREE_TYPE (type);
2089 bool addressable = TREE_ADDRESSABLE (p);
2091 /* Rewrite the PARM_DECL's type with its component. */
2092 TREE_TYPE (p) = subtype;
2093 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
2094 DECL_MODE (p) = VOIDmode;
2095 DECL_SIZE (p) = NULL;
2096 DECL_SIZE_UNIT (p) = NULL;
2097 /* If this arg must go in memory, put it in a pseudo here.
2098 We can't allow it to go in memory as per normal parms,
2099 because the usual place might not have the imag part
2100 adjacent to the real part. */
2101 DECL_ARTIFICIAL (p) = addressable;
2102 DECL_IGNORED_P (p) = addressable;
2103 TREE_ADDRESSABLE (p) = 0;
2106 /* Build a second synthetic decl. */
2107 decl = build_decl (EXPR_LOCATION (p),
2108 PARM_DECL, NULL_TREE, subtype);
2109 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
2110 DECL_ARTIFICIAL (decl) = addressable;
2111 DECL_IGNORED_P (decl) = addressable;
2112 layout_decl (decl, 0);
2114 /* Splice it in; skip the new decl. */
2115 TREE_CHAIN (decl) = TREE_CHAIN (p);
2116 TREE_CHAIN (p) = decl;
2124 /* A subroutine of assign_parms. Adjust the parameter list to incorporate
2125 the hidden struct return argument, and (abi willing) complex args.
2126 Return the new parameter list. */
2129 assign_parms_augmented_arg_list (struct assign_parm_data_all *all)
2131 tree fndecl = current_function_decl;
2132 tree fntype = TREE_TYPE (fndecl);
2133 tree fnargs = DECL_ARGUMENTS (fndecl);
2135 /* If struct value address is treated as the first argument, make it so. */
2136 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
2137 && ! cfun->returns_pcc_struct
2138 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
2140 tree type = build_pointer_type (TREE_TYPE (fntype));
2143 decl = build_decl (DECL_SOURCE_LOCATION (fndecl),
2144 PARM_DECL, NULL_TREE, type);
2145 DECL_ARG_TYPE (decl) = type;
2146 DECL_ARTIFICIAL (decl) = 1;
2147 DECL_IGNORED_P (decl) = 1;
2149 TREE_CHAIN (decl) = fnargs;
2151 all->function_result_decl = decl;
2154 all->orig_fnargs = fnargs;
2156 /* If the target wants to split complex arguments into scalars, do so. */
2157 if (targetm.calls.split_complex_arg)
2158 fnargs = split_complex_args (fnargs);
2163 /* A subroutine of assign_parms. Examine PARM and pull out type and mode
2164 data for the parameter. Incorporate ABI specifics such as pass-by-
2165 reference and type promotion. */
2168 assign_parm_find_data_types (struct assign_parm_data_all *all, tree parm,
2169 struct assign_parm_data_one *data)
2171 tree nominal_type, passed_type;
2172 enum machine_mode nominal_mode, passed_mode, promoted_mode;
2175 memset (data, 0, sizeof (*data));
2177 /* NAMED_ARG is a misnomer. We really mean 'non-variadic'. */
2179 data->named_arg = 1; /* No variadic parms. */
2180 else if (TREE_CHAIN (parm))
2181 data->named_arg = 1; /* Not the last non-variadic parm. */
2182 else if (targetm.calls.strict_argument_naming (&all->args_so_far))
2183 data->named_arg = 1; /* Only variadic ones are unnamed. */
2185 data->named_arg = 0; /* Treat as variadic. */
2187 nominal_type = TREE_TYPE (parm);
2188 passed_type = DECL_ARG_TYPE (parm);
2190 /* Look out for errors propagating this far. Also, if the parameter's
2191 type is void then its value doesn't matter. */
2192 if (TREE_TYPE (parm) == error_mark_node
2193 /* This can happen after weird syntax errors
2194 or if an enum type is defined among the parms. */
2195 || TREE_CODE (parm) != PARM_DECL
2196 || passed_type == NULL
2197 || VOID_TYPE_P (nominal_type))
2199 nominal_type = passed_type = void_type_node;
2200 nominal_mode = passed_mode = promoted_mode = VOIDmode;
2204 /* Find mode of arg as it is passed, and mode of arg as it should be
2205 during execution of this function. */
2206 passed_mode = TYPE_MODE (passed_type);
2207 nominal_mode = TYPE_MODE (nominal_type);
2209 /* If the parm is to be passed as a transparent union, use the type of
2210 the first field for the tests below. We have already verified that
2211 the modes are the same. */
2212 if (TREE_CODE (passed_type) == UNION_TYPE
2213 && TYPE_TRANSPARENT_UNION (passed_type))
2214 passed_type = TREE_TYPE (TYPE_FIELDS (passed_type));
2216 /* See if this arg was passed by invisible reference. */
2217 if (pass_by_reference (&all->args_so_far, passed_mode,
2218 passed_type, data->named_arg))
2220 passed_type = nominal_type = build_pointer_type (passed_type);
2221 data->passed_pointer = true;
2222 passed_mode = nominal_mode = Pmode;
2225 /* Find mode as it is passed by the ABI. */
2226 unsignedp = TYPE_UNSIGNED (passed_type);
2227 promoted_mode = promote_function_mode (passed_type, passed_mode, &unsignedp,
2228 TREE_TYPE (current_function_decl), 0);
2231 data->nominal_type = nominal_type;
2232 data->passed_type = passed_type;
2233 data->nominal_mode = nominal_mode;
2234 data->passed_mode = passed_mode;
2235 data->promoted_mode = promoted_mode;
2238 /* A subroutine of assign_parms. Invoke setup_incoming_varargs. */
2241 assign_parms_setup_varargs (struct assign_parm_data_all *all,
2242 struct assign_parm_data_one *data, bool no_rtl)
2244 int varargs_pretend_bytes = 0;
2246 targetm.calls.setup_incoming_varargs (&all->args_so_far,
2247 data->promoted_mode,
2249 &varargs_pretend_bytes, no_rtl);
2251 /* If the back-end has requested extra stack space, record how much is
2252 needed. Do not change pretend_args_size otherwise since it may be
2253 nonzero from an earlier partial argument. */
2254 if (varargs_pretend_bytes > 0)
2255 all->pretend_args_size = varargs_pretend_bytes;
2258 /* A subroutine of assign_parms. Set DATA->ENTRY_PARM corresponding to
2259 the incoming location of the current parameter. */
2262 assign_parm_find_entry_rtl (struct assign_parm_data_all *all,
2263 struct assign_parm_data_one *data)
2265 HOST_WIDE_INT pretend_bytes = 0;
2269 if (data->promoted_mode == VOIDmode)
2271 data->entry_parm = data->stack_parm = const0_rtx;
2275 #ifdef FUNCTION_INCOMING_ARG
2276 entry_parm = FUNCTION_INCOMING_ARG (all->args_so_far, data->promoted_mode,
2277 data->passed_type, data->named_arg);
2279 entry_parm = FUNCTION_ARG (all->args_so_far, data->promoted_mode,
2280 data->passed_type, data->named_arg);
2283 if (entry_parm == 0)
2284 data->promoted_mode = data->passed_mode;
2286 /* Determine parm's home in the stack, in case it arrives in the stack
2287 or we should pretend it did. Compute the stack position and rtx where
2288 the argument arrives and its size.
2290 There is one complexity here: If this was a parameter that would
2291 have been passed in registers, but wasn't only because it is
2292 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2293 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2294 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of 0
2295 as it was the previous time. */
2296 in_regs = entry_parm != 0;
2297 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2300 if (!in_regs && !data->named_arg)
2302 if (targetm.calls.pretend_outgoing_varargs_named (&all->args_so_far))
2305 #ifdef FUNCTION_INCOMING_ARG
2306 tem = FUNCTION_INCOMING_ARG (all->args_so_far, data->promoted_mode,
2307 data->passed_type, true);
2309 tem = FUNCTION_ARG (all->args_so_far, data->promoted_mode,
2310 data->passed_type, true);
2312 in_regs = tem != NULL;
2316 /* If this parameter was passed both in registers and in the stack, use
2317 the copy on the stack. */
2318 if (targetm.calls.must_pass_in_stack (data->promoted_mode,
2326 partial = targetm.calls.arg_partial_bytes (&all->args_so_far,
2327 data->promoted_mode,
2330 data->partial = partial;
2332 /* The caller might already have allocated stack space for the
2333 register parameters. */
2334 if (partial != 0 && all->reg_parm_stack_space == 0)
2336 /* Part of this argument is passed in registers and part
2337 is passed on the stack. Ask the prologue code to extend
2338 the stack part so that we can recreate the full value.
2340 PRETEND_BYTES is the size of the registers we need to store.
2341 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
2342 stack space that the prologue should allocate.
2344 Internally, gcc assumes that the argument pointer is aligned
2345 to STACK_BOUNDARY bits. This is used both for alignment
2346 optimizations (see init_emit) and to locate arguments that are
2347 aligned to more than PARM_BOUNDARY bits. We must preserve this
2348 invariant by rounding CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to
2349 a stack boundary. */
2351 /* We assume at most one partial arg, and it must be the first
2352 argument on the stack. */
2353 gcc_assert (!all->extra_pretend_bytes && !all->pretend_args_size);
2355 pretend_bytes = partial;
2356 all->pretend_args_size = CEIL_ROUND (pretend_bytes, STACK_BYTES);
2358 /* We want to align relative to the actual stack pointer, so
2359 don't include this in the stack size until later. */
2360 all->extra_pretend_bytes = all->pretend_args_size;
2364 locate_and_pad_parm (data->promoted_mode, data->passed_type, in_regs,
2365 entry_parm ? data->partial : 0, current_function_decl,
2366 &all->stack_args_size, &data->locate);
2368 /* Update parm_stack_boundary if this parameter is passed in the
2370 if (!in_regs && crtl->parm_stack_boundary < data->locate.boundary)
2371 crtl->parm_stack_boundary = data->locate.boundary;
2373 /* Adjust offsets to include the pretend args. */
2374 pretend_bytes = all->extra_pretend_bytes - pretend_bytes;
2375 data->locate.slot_offset.constant += pretend_bytes;
2376 data->locate.offset.constant += pretend_bytes;
2378 data->entry_parm = entry_parm;
2381 /* A subroutine of assign_parms. If there is actually space on the stack
2382 for this parm, count it in stack_args_size and return true. */
2385 assign_parm_is_stack_parm (struct assign_parm_data_all *all,
2386 struct assign_parm_data_one *data)
2388 /* Trivially true if we've no incoming register. */
2389 if (data->entry_parm == NULL)
2391 /* Also true if we're partially in registers and partially not,
2392 since we've arranged to drop the entire argument on the stack. */
2393 else if (data->partial != 0)
2395 /* Also true if the target says that it's passed in both registers
2396 and on the stack. */
2397 else if (GET_CODE (data->entry_parm) == PARALLEL
2398 && XEXP (XVECEXP (data->entry_parm, 0, 0), 0) == NULL_RTX)
2400 /* Also true if the target says that there's stack allocated for
2401 all register parameters. */
2402 else if (all->reg_parm_stack_space > 0)
2404 /* Otherwise, no, this parameter has no ABI defined stack slot. */
2408 all->stack_args_size.constant += data->locate.size.constant;
2409 if (data->locate.size.var)
2410 ADD_PARM_SIZE (all->stack_args_size, data->locate.size.var);
2415 /* A subroutine of assign_parms. Given that this parameter is allocated
2416 stack space by the ABI, find it. */
2419 assign_parm_find_stack_rtl (tree parm, struct assign_parm_data_one *data)
2421 rtx offset_rtx, stack_parm;
2422 unsigned int align, boundary;
2424 /* If we're passing this arg using a reg, make its stack home the
2425 aligned stack slot. */
2426 if (data->entry_parm)
2427 offset_rtx = ARGS_SIZE_RTX (data->locate.slot_offset);
2429 offset_rtx = ARGS_SIZE_RTX (data->locate.offset);
2431 stack_parm = crtl->args.internal_arg_pointer;
2432 if (offset_rtx != const0_rtx)
2433 stack_parm = gen_rtx_PLUS (Pmode, stack_parm, offset_rtx);
2434 stack_parm = gen_rtx_MEM (data->promoted_mode, stack_parm);
2436 if (!data->passed_pointer)
2438 set_mem_attributes (stack_parm, parm, 1);
2439 /* set_mem_attributes could set MEM_SIZE to the passed mode's size,
2440 while promoted mode's size is needed. */
2441 if (data->promoted_mode != BLKmode
2442 && data->promoted_mode != DECL_MODE (parm))
2444 set_mem_size (stack_parm,
2445 GEN_INT (GET_MODE_SIZE (data->promoted_mode)));
2446 if (MEM_EXPR (stack_parm) && MEM_OFFSET (stack_parm))
2448 int offset = subreg_lowpart_offset (DECL_MODE (parm),
2449 data->promoted_mode);
2451 set_mem_offset (stack_parm,
2452 plus_constant (MEM_OFFSET (stack_parm),
2458 boundary = data->locate.boundary;
2459 align = BITS_PER_UNIT;
2461 /* If we're padding upward, we know that the alignment of the slot
2462 is FUNCTION_ARG_BOUNDARY. If we're using slot_offset, we're
2463 intentionally forcing upward padding. Otherwise we have to come
2464 up with a guess at the alignment based on OFFSET_RTX. */
2465 if (data->locate.where_pad != downward || data->entry_parm)
2467 else if (CONST_INT_P (offset_rtx))
2469 align = INTVAL (offset_rtx) * BITS_PER_UNIT | boundary;
2470 align = align & -align;
2472 set_mem_align (stack_parm, align);
2474 if (data->entry_parm)
2475 set_reg_attrs_for_parm (data->entry_parm, stack_parm);
2477 data->stack_parm = stack_parm;
2480 /* A subroutine of assign_parms. Adjust DATA->ENTRY_RTL such that it's
2481 always valid and contiguous. */
2484 assign_parm_adjust_entry_rtl (struct assign_parm_data_one *data)
2486 rtx entry_parm = data->entry_parm;
2487 rtx stack_parm = data->stack_parm;
2489 /* If this parm was passed part in regs and part in memory, pretend it
2490 arrived entirely in memory by pushing the register-part onto the stack.
2491 In the special case of a DImode or DFmode that is split, we could put
2492 it together in a pseudoreg directly, but for now that's not worth
2494 if (data->partial != 0)
2496 /* Handle calls that pass values in multiple non-contiguous
2497 locations. The Irix 6 ABI has examples of this. */
2498 if (GET_CODE (entry_parm) == PARALLEL)
2499 emit_group_store (validize_mem (stack_parm), entry_parm,
2501 int_size_in_bytes (data->passed_type));
2504 gcc_assert (data->partial % UNITS_PER_WORD == 0);
2505 move_block_from_reg (REGNO (entry_parm), validize_mem (stack_parm),
2506 data->partial / UNITS_PER_WORD);
2509 entry_parm = stack_parm;
2512 /* If we didn't decide this parm came in a register, by default it came
2514 else if (entry_parm == NULL)
2515 entry_parm = stack_parm;
2517 /* When an argument is passed in multiple locations, we can't make use
2518 of this information, but we can save some copying if the whole argument
2519 is passed in a single register. */
2520 else if (GET_CODE (entry_parm) == PARALLEL
2521 && data->nominal_mode != BLKmode
2522 && data->passed_mode != BLKmode)
2524 size_t i, len = XVECLEN (entry_parm, 0);
2526 for (i = 0; i < len; i++)
2527 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
2528 && REG_P (XEXP (XVECEXP (entry_parm, 0, i), 0))
2529 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
2530 == data->passed_mode)
2531 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
2533 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
2538 data->entry_parm = entry_parm;
2541 /* A subroutine of assign_parms. Reconstitute any values which were
2542 passed in multiple registers and would fit in a single register. */
2545 assign_parm_remove_parallels (struct assign_parm_data_one *data)
2547 rtx entry_parm = data->entry_parm;
2549 /* Convert the PARALLEL to a REG of the same mode as the parallel.
2550 This can be done with register operations rather than on the
2551 stack, even if we will store the reconstituted parameter on the
2553 if (GET_CODE (entry_parm) == PARALLEL && GET_MODE (entry_parm) != BLKmode)
2555 rtx parmreg = gen_reg_rtx (GET_MODE (entry_parm));
2556 emit_group_store (parmreg, entry_parm, data->passed_type,
2557 GET_MODE_SIZE (GET_MODE (entry_parm)));
2558 entry_parm = parmreg;
2561 data->entry_parm = entry_parm;
2564 /* A subroutine of assign_parms. Adjust DATA->STACK_RTL such that it's
2565 always valid and properly aligned. */
2568 assign_parm_adjust_stack_rtl (struct assign_parm_data_one *data)
2570 rtx stack_parm = data->stack_parm;
2572 /* If we can't trust the parm stack slot to be aligned enough for its
2573 ultimate type, don't use that slot after entry. We'll make another
2574 stack slot, if we need one. */
2576 && ((STRICT_ALIGNMENT
2577 && GET_MODE_ALIGNMENT (data->nominal_mode) > MEM_ALIGN (stack_parm))
2578 || (data->nominal_type
2579 && TYPE_ALIGN (data->nominal_type) > MEM_ALIGN (stack_parm)
2580 && MEM_ALIGN (stack_parm) < PREFERRED_STACK_BOUNDARY)))
2583 /* If parm was passed in memory, and we need to convert it on entry,
2584 don't store it back in that same slot. */
2585 else if (data->entry_parm == stack_parm
2586 && data->nominal_mode != BLKmode
2587 && data->nominal_mode != data->passed_mode)
2590 /* If stack protection is in effect for this function, don't leave any
2591 pointers in their passed stack slots. */
2592 else if (crtl->stack_protect_guard
2593 && (flag_stack_protect == 2
2594 || data->passed_pointer
2595 || POINTER_TYPE_P (data->nominal_type)))
2598 data->stack_parm = stack_parm;
2601 /* A subroutine of assign_parms. Return true if the current parameter
2602 should be stored as a BLKmode in the current frame. */
2605 assign_parm_setup_block_p (struct assign_parm_data_one *data)
2607 if (data->nominal_mode == BLKmode)
2609 if (GET_MODE (data->entry_parm) == BLKmode)
2612 #ifdef BLOCK_REG_PADDING
2613 /* Only assign_parm_setup_block knows how to deal with register arguments
2614 that are padded at the least significant end. */
2615 if (REG_P (data->entry_parm)
2616 && GET_MODE_SIZE (data->promoted_mode) < UNITS_PER_WORD
2617 && (BLOCK_REG_PADDING (data->passed_mode, data->passed_type, 1)
2618 == (BYTES_BIG_ENDIAN ? upward : downward)))
2625 /* A subroutine of assign_parms. Arrange for the parameter to be
2626 present and valid in DATA->STACK_RTL. */
2629 assign_parm_setup_block (struct assign_parm_data_all *all,
2630 tree parm, struct assign_parm_data_one *data)
2632 rtx entry_parm = data->entry_parm;
2633 rtx stack_parm = data->stack_parm;
2635 HOST_WIDE_INT size_stored;
2637 if (GET_CODE (entry_parm) == PARALLEL)
2638 entry_parm = emit_group_move_into_temps (entry_parm);
2640 size = int_size_in_bytes (data->passed_type);
2641 size_stored = CEIL_ROUND (size, UNITS_PER_WORD);
2642 if (stack_parm == 0)
2644 DECL_ALIGN (parm) = MAX (DECL_ALIGN (parm), BITS_PER_WORD);
2645 stack_parm = assign_stack_local (BLKmode, size_stored,
2647 if (GET_MODE_SIZE (GET_MODE (entry_parm)) == size)
2648 PUT_MODE (stack_parm, GET_MODE (entry_parm));
2649 set_mem_attributes (stack_parm, parm, 1);
2652 /* If a BLKmode arrives in registers, copy it to a stack slot. Handle
2653 calls that pass values in multiple non-contiguous locations. */
2654 if (REG_P (entry_parm) || GET_CODE (entry_parm) == PARALLEL)
2658 /* Note that we will be storing an integral number of words.
2659 So we have to be careful to ensure that we allocate an
2660 integral number of words. We do this above when we call
2661 assign_stack_local if space was not allocated in the argument
2662 list. If it was, this will not work if PARM_BOUNDARY is not
2663 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2664 if it becomes a problem. Exception is when BLKmode arrives
2665 with arguments not conforming to word_mode. */
2667 if (data->stack_parm == 0)
2669 else if (GET_CODE (entry_parm) == PARALLEL)
2672 gcc_assert (!size || !(PARM_BOUNDARY % BITS_PER_WORD));
2674 mem = validize_mem (stack_parm);
2676 /* Handle values in multiple non-contiguous locations. */
2677 if (GET_CODE (entry_parm) == PARALLEL)
2679 push_to_sequence2 (all->first_conversion_insn,
2680 all->last_conversion_insn);
2681 emit_group_store (mem, entry_parm, data->passed_type, size);
2682 all->first_conversion_insn = get_insns ();
2683 all->last_conversion_insn = get_last_insn ();
2690 /* If SIZE is that of a mode no bigger than a word, just use
2691 that mode's store operation. */
2692 else if (size <= UNITS_PER_WORD)
2694 enum machine_mode mode
2695 = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
2698 #ifdef BLOCK_REG_PADDING
2699 && (size == UNITS_PER_WORD
2700 || (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2701 != (BYTES_BIG_ENDIAN ? upward : downward)))
2707 /* We are really truncating a word_mode value containing
2708 SIZE bytes into a value of mode MODE. If such an
2709 operation requires no actual instructions, we can refer
2710 to the value directly in mode MODE, otherwise we must
2711 start with the register in word_mode and explicitly
2713 if (TRULY_NOOP_TRUNCATION (size * BITS_PER_UNIT, BITS_PER_WORD))
2714 reg = gen_rtx_REG (mode, REGNO (entry_parm));
2717 reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
2718 reg = convert_to_mode (mode, copy_to_reg (reg), 1);
2720 emit_move_insn (change_address (mem, mode, 0), reg);
2723 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
2724 machine must be aligned to the left before storing
2725 to memory. Note that the previous test doesn't
2726 handle all cases (e.g. SIZE == 3). */
2727 else if (size != UNITS_PER_WORD
2728 #ifdef BLOCK_REG_PADDING
2729 && (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2737 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
2738 rtx reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
2740 x = expand_shift (LSHIFT_EXPR, word_mode, reg,
2741 build_int_cst (NULL_TREE, by),
2743 tem = change_address (mem, word_mode, 0);
2744 emit_move_insn (tem, x);
2747 move_block_from_reg (REGNO (entry_parm), mem,
2748 size_stored / UNITS_PER_WORD);
2751 move_block_from_reg (REGNO (entry_parm), mem,
2752 size_stored / UNITS_PER_WORD);
2754 else if (data->stack_parm == 0)
2756 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2757 emit_block_move (stack_parm, data->entry_parm, GEN_INT (size),
2759 all->first_conversion_insn = get_insns ();
2760 all->last_conversion_insn = get_last_insn ();
2764 data->stack_parm = stack_parm;
2765 SET_DECL_RTL (parm, stack_parm);
2768 /* A subroutine of assign_parms. Allocate a pseudo to hold the current
2769 parameter. Get it there. Perform all ABI specified conversions. */
2772 assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm,
2773 struct assign_parm_data_one *data)
2776 enum machine_mode promoted_nominal_mode;
2777 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (parm));
2778 bool did_conversion = false;
2780 /* Store the parm in a pseudoregister during the function, but we may
2781 need to do it in a wider mode. Using 2 here makes the result
2782 consistent with promote_decl_mode and thus expand_expr_real_1. */
2783 promoted_nominal_mode
2784 = promote_function_mode (data->nominal_type, data->nominal_mode, &unsignedp,
2785 TREE_TYPE (current_function_decl), 2);
2787 parmreg = gen_reg_rtx (promoted_nominal_mode);
2789 if (!DECL_ARTIFICIAL (parm))
2790 mark_user_reg (parmreg);
2792 /* If this was an item that we received a pointer to,
2793 set DECL_RTL appropriately. */
2794 if (data->passed_pointer)
2796 rtx x = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data->passed_type)), parmreg);
2797 set_mem_attributes (x, parm, 1);
2798 SET_DECL_RTL (parm, x);
2801 SET_DECL_RTL (parm, parmreg);
2803 assign_parm_remove_parallels (data);
2805 /* Copy the value into the register, thus bridging between
2806 assign_parm_find_data_types and expand_expr_real_1. */
2807 if (data->nominal_mode != data->passed_mode
2808 || promoted_nominal_mode != data->promoted_mode)
2812 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
2813 mode, by the caller. We now have to convert it to
2814 NOMINAL_MODE, if different. However, PARMREG may be in
2815 a different mode than NOMINAL_MODE if it is being stored
2818 If ENTRY_PARM is a hard register, it might be in a register
2819 not valid for operating in its mode (e.g., an odd-numbered
2820 register for a DFmode). In that case, moves are the only
2821 thing valid, so we can't do a convert from there. This
2822 occurs when the calling sequence allow such misaligned
2825 In addition, the conversion may involve a call, which could
2826 clobber parameters which haven't been copied to pseudo
2827 registers yet. Therefore, we must first copy the parm to
2828 a pseudo reg here, and save the conversion until after all
2829 parameters have been moved. */
2831 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
2833 emit_move_insn (tempreg, validize_mem (data->entry_parm));
2835 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2836 tempreg = convert_to_mode (data->nominal_mode, tempreg, unsignedp);
2838 if (GET_CODE (tempreg) == SUBREG
2839 && GET_MODE (tempreg) == data->nominal_mode
2840 && REG_P (SUBREG_REG (tempreg))
2841 && data->nominal_mode == data->passed_mode
2842 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (data->entry_parm)
2843 && GET_MODE_SIZE (GET_MODE (tempreg))
2844 < GET_MODE_SIZE (GET_MODE (data->entry_parm)))
2846 /* The argument is already sign/zero extended, so note it
2848 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
2849 SUBREG_PROMOTED_UNSIGNED_SET (tempreg, unsignedp);
2852 /* TREE_USED gets set erroneously during expand_assignment. */
2853 save_tree_used = TREE_USED (parm);
2854 expand_assignment (parm, make_tree (data->nominal_type, tempreg), false);
2855 TREE_USED (parm) = save_tree_used;
2856 all->first_conversion_insn = get_insns ();
2857 all->last_conversion_insn = get_last_insn ();
2860 did_conversion = true;
2863 emit_move_insn (parmreg, validize_mem (data->entry_parm));
2865 /* If we were passed a pointer but the actual value can safely live
2866 in a register, put it in one. */
2867 if (data->passed_pointer
2868 && TYPE_MODE (TREE_TYPE (parm)) != BLKmode
2869 /* If by-reference argument was promoted, demote it. */
2870 && (TYPE_MODE (TREE_TYPE (parm)) != GET_MODE (DECL_RTL (parm))
2871 || use_register_for_decl (parm)))
2873 /* We can't use nominal_mode, because it will have been set to
2874 Pmode above. We must use the actual mode of the parm. */
2875 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
2876 mark_user_reg (parmreg);
2878 if (GET_MODE (parmreg) != GET_MODE (DECL_RTL (parm)))
2880 rtx tempreg = gen_reg_rtx (GET_MODE (DECL_RTL (parm)));
2881 int unsigned_p = TYPE_UNSIGNED (TREE_TYPE (parm));
2883 push_to_sequence2 (all->first_conversion_insn,
2884 all->last_conversion_insn);
2885 emit_move_insn (tempreg, DECL_RTL (parm));
2886 tempreg = convert_to_mode (GET_MODE (parmreg), tempreg, unsigned_p);
2887 emit_move_insn (parmreg, tempreg);
2888 all->first_conversion_insn = get_insns ();
2889 all->last_conversion_insn = get_last_insn ();
2892 did_conversion = true;
2895 emit_move_insn (parmreg, DECL_RTL (parm));
2897 SET_DECL_RTL (parm, parmreg);
2899 /* STACK_PARM is the pointer, not the parm, and PARMREG is
2901 data->stack_parm = NULL;
2904 /* Mark the register as eliminable if we did no conversion and it was
2905 copied from memory at a fixed offset, and the arg pointer was not
2906 copied to a pseudo-reg. If the arg pointer is a pseudo reg or the
2907 offset formed an invalid address, such memory-equivalences as we
2908 make here would screw up life analysis for it. */
2909 if (data->nominal_mode == data->passed_mode
2911 && data->stack_parm != 0
2912 && MEM_P (data->stack_parm)
2913 && data->locate.offset.var == 0
2914 && reg_mentioned_p (virtual_incoming_args_rtx,
2915 XEXP (data->stack_parm, 0)))
2917 rtx linsn = get_last_insn ();
2920 /* Mark complex types separately. */
2921 if (GET_CODE (parmreg) == CONCAT)
2923 enum machine_mode submode
2924 = GET_MODE_INNER (GET_MODE (parmreg));
2925 int regnor = REGNO (XEXP (parmreg, 0));
2926 int regnoi = REGNO (XEXP (parmreg, 1));
2927 rtx stackr = adjust_address_nv (data->stack_parm, submode, 0);
2928 rtx stacki = adjust_address_nv (data->stack_parm, submode,
2929 GET_MODE_SIZE (submode));
2931 /* Scan backwards for the set of the real and
2933 for (sinsn = linsn; sinsn != 0;
2934 sinsn = prev_nonnote_insn (sinsn))
2936 set = single_set (sinsn);
2940 if (SET_DEST (set) == regno_reg_rtx [regnoi])
2941 set_unique_reg_note (sinsn, REG_EQUIV, stacki);
2942 else if (SET_DEST (set) == regno_reg_rtx [regnor])
2943 set_unique_reg_note (sinsn, REG_EQUIV, stackr);
2946 else if ((set = single_set (linsn)) != 0
2947 && SET_DEST (set) == parmreg)
2948 set_unique_reg_note (linsn, REG_EQUIV, data->stack_parm);
2951 /* For pointer data type, suggest pointer register. */
2952 if (POINTER_TYPE_P (TREE_TYPE (parm)))
2953 mark_reg_pointer (parmreg,
2954 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
2957 /* A subroutine of assign_parms. Allocate stack space to hold the current
2958 parameter. Get it there. Perform all ABI specified conversions. */
2961 assign_parm_setup_stack (struct assign_parm_data_all *all, tree parm,
2962 struct assign_parm_data_one *data)
2964 /* Value must be stored in the stack slot STACK_PARM during function
2966 bool to_conversion = false;
2968 assign_parm_remove_parallels (data);
2970 if (data->promoted_mode != data->nominal_mode)
2972 /* Conversion is required. */
2973 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
2975 emit_move_insn (tempreg, validize_mem (data->entry_parm));
2977 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2978 to_conversion = true;
2980 data->entry_parm = convert_to_mode (data->nominal_mode, tempreg,
2981 TYPE_UNSIGNED (TREE_TYPE (parm)));
2983 if (data->stack_parm)
2985 int offset = subreg_lowpart_offset (data->nominal_mode,
2986 GET_MODE (data->stack_parm));
2987 /* ??? This may need a big-endian conversion on sparc64. */
2989 = adjust_address (data->stack_parm, data->nominal_mode, 0);
2990 if (offset && MEM_OFFSET (data->stack_parm))
2991 set_mem_offset (data->stack_parm,
2992 plus_constant (MEM_OFFSET (data->stack_parm),
2997 if (data->entry_parm != data->stack_parm)
3001 if (data->stack_parm == 0)
3003 int align = STACK_SLOT_ALIGNMENT (data->passed_type,
3004 GET_MODE (data->entry_parm),
3005 TYPE_ALIGN (data->passed_type));
3007 = assign_stack_local (GET_MODE (data->entry_parm),
3008 GET_MODE_SIZE (GET_MODE (data->entry_parm)),
3010 set_mem_attributes (data->stack_parm, parm, 1);
3013 dest = validize_mem (data->stack_parm);
3014 src = validize_mem (data->entry_parm);
3018 /* Use a block move to handle potentially misaligned entry_parm. */
3020 push_to_sequence2 (all->first_conversion_insn,
3021 all->last_conversion_insn);
3022 to_conversion = true;
3024 emit_block_move (dest, src,
3025 GEN_INT (int_size_in_bytes (data->passed_type)),
3029 emit_move_insn (dest, src);
3034 all->first_conversion_insn = get_insns ();
3035 all->last_conversion_insn = get_last_insn ();
3039 SET_DECL_RTL (parm, data->stack_parm);
3042 /* A subroutine of assign_parms. If the ABI splits complex arguments, then
3043 undo the frobbing that we did in assign_parms_augmented_arg_list. */
3046 assign_parms_unsplit_complex (struct assign_parm_data_all *all, tree fnargs)
3049 tree orig_fnargs = all->orig_fnargs;
3051 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm))
3053 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
3054 && targetm.calls.split_complex_arg (TREE_TYPE (parm)))
3056 rtx tmp, real, imag;
3057 enum machine_mode inner = GET_MODE_INNER (DECL_MODE (parm));
3059 real = DECL_RTL (fnargs);
3060 imag = DECL_RTL (TREE_CHAIN (fnargs));
3061 if (inner != GET_MODE (real))
3063 real = gen_lowpart_SUBREG (inner, real);
3064 imag = gen_lowpart_SUBREG (inner, imag);
3067 if (TREE_ADDRESSABLE (parm))
3070 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (parm));
3071 int align = STACK_SLOT_ALIGNMENT (TREE_TYPE (parm),
3073 TYPE_ALIGN (TREE_TYPE (parm)));
3075 /* split_complex_arg put the real and imag parts in
3076 pseudos. Move them to memory. */
3077 tmp = assign_stack_local (DECL_MODE (parm), size, align);
3078 set_mem_attributes (tmp, parm, 1);
3079 rmem = adjust_address_nv (tmp, inner, 0);
3080 imem = adjust_address_nv (tmp, inner, GET_MODE_SIZE (inner));
3081 push_to_sequence2 (all->first_conversion_insn,
3082 all->last_conversion_insn);
3083 emit_move_insn (rmem, real);
3084 emit_move_insn (imem, imag);
3085 all->first_conversion_insn = get_insns ();
3086 all->last_conversion_insn = get_last_insn ();
3090 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
3091 SET_DECL_RTL (parm, tmp);
3093 real = DECL_INCOMING_RTL (fnargs);
3094 imag = DECL_INCOMING_RTL (TREE_CHAIN (fnargs));
3095 if (inner != GET_MODE (real))
3097 real = gen_lowpart_SUBREG (inner, real);
3098 imag = gen_lowpart_SUBREG (inner, imag);
3100 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
3101 set_decl_incoming_rtl (parm, tmp, false);
3102 fnargs = TREE_CHAIN (fnargs);
3106 SET_DECL_RTL (parm, DECL_RTL (fnargs));
3107 set_decl_incoming_rtl (parm, DECL_INCOMING_RTL (fnargs), false);
3109 /* Set MEM_EXPR to the original decl, i.e. to PARM,
3110 instead of the copy of decl, i.e. FNARGS. */
3111 if (DECL_INCOMING_RTL (parm) && MEM_P (DECL_INCOMING_RTL (parm)))
3112 set_mem_expr (DECL_INCOMING_RTL (parm), parm);
3115 fnargs = TREE_CHAIN (fnargs);
3119 /* Assign RTL expressions to the function's parameters. This may involve
3120 copying them into registers and using those registers as the DECL_RTL. */
3123 assign_parms (tree fndecl)
3125 struct assign_parm_data_all all;
3128 crtl->args.internal_arg_pointer
3129 = targetm.calls.internal_arg_pointer ();
3131 assign_parms_initialize_all (&all);
3132 fnargs = assign_parms_augmented_arg_list (&all);
3134 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
3136 struct assign_parm_data_one data;
3138 /* Extract the type of PARM; adjust it according to ABI. */
3139 assign_parm_find_data_types (&all, parm, &data);
3141 /* Early out for errors and void parameters. */
3142 if (data.passed_mode == VOIDmode)
3144 SET_DECL_RTL (parm, const0_rtx);
3145 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
3149 /* Estimate stack alignment from parameter alignment. */
3150 if (SUPPORTS_STACK_ALIGNMENT)
3152 unsigned int align = FUNCTION_ARG_BOUNDARY (data.promoted_mode,
3154 align = MINIMUM_ALIGNMENT (data.passed_type, data.promoted_mode,
3156 if (TYPE_ALIGN (data.nominal_type) > align)
3157 align = MINIMUM_ALIGNMENT (data.nominal_type,
3158 TYPE_MODE (data.nominal_type),
3159 TYPE_ALIGN (data.nominal_type));
3160 if (crtl->stack_alignment_estimated < align)
3162 gcc_assert (!crtl->stack_realign_processed);
3163 crtl->stack_alignment_estimated = align;
3167 if (cfun->stdarg && !TREE_CHAIN (parm))
3168 assign_parms_setup_varargs (&all, &data, false);
3170 /* Find out where the parameter arrives in this function. */
3171 assign_parm_find_entry_rtl (&all, &data);
3173 /* Find out where stack space for this parameter might be. */
3174 if (assign_parm_is_stack_parm (&all, &data))
3176 assign_parm_find_stack_rtl (parm, &data);
3177 assign_parm_adjust_entry_rtl (&data);
3180 /* Record permanently how this parm was passed. */
3181 set_decl_incoming_rtl (parm, data.entry_parm, data.passed_pointer);
3183 /* Update info on where next arg arrives in registers. */
3184 FUNCTION_ARG_ADVANCE (all.args_so_far, data.promoted_mode,
3185 data.passed_type, data.named_arg);
3187 assign_parm_adjust_stack_rtl (&data);
3189 if (assign_parm_setup_block_p (&data))
3190 assign_parm_setup_block (&all, parm, &data);
3191 else if (data.passed_pointer || use_register_for_decl (parm))
3192 assign_parm_setup_reg (&all, parm, &data);
3194 assign_parm_setup_stack (&all, parm, &data);
3197 if (targetm.calls.split_complex_arg && fnargs != all.orig_fnargs)
3198 assign_parms_unsplit_complex (&all, fnargs);
3200 /* Output all parameter conversion instructions (possibly including calls)
3201 now that all parameters have been copied out of hard registers. */
3202 emit_insn (all.first_conversion_insn);
3204 /* Estimate reload stack alignment from scalar return mode. */
3205 if (SUPPORTS_STACK_ALIGNMENT)
3207 if (DECL_RESULT (fndecl))
3209 tree type = TREE_TYPE (DECL_RESULT (fndecl));
3210 enum machine_mode mode = TYPE_MODE (type);
3214 && !AGGREGATE_TYPE_P (type))
3216 unsigned int align = GET_MODE_ALIGNMENT (mode);
3217 if (crtl->stack_alignment_estimated < align)
3219 gcc_assert (!crtl->stack_realign_processed);
3220 crtl->stack_alignment_estimated = align;
3226 /* If we are receiving a struct value address as the first argument, set up
3227 the RTL for the function result. As this might require code to convert
3228 the transmitted address to Pmode, we do this here to ensure that possible
3229 preliminary conversions of the address have been emitted already. */
3230 if (all.function_result_decl)
3232 tree result = DECL_RESULT (current_function_decl);
3233 rtx addr = DECL_RTL (all.function_result_decl);
3236 if (DECL_BY_REFERENCE (result))
3240 addr = convert_memory_address (Pmode, addr);
3241 x = gen_rtx_MEM (DECL_MODE (result), addr);
3242 set_mem_attributes (x, result, 1);
3244 SET_DECL_RTL (result, x);
3247 /* We have aligned all the args, so add space for the pretend args. */
3248 crtl->args.pretend_args_size = all.pretend_args_size;
3249 all.stack_args_size.constant += all.extra_pretend_bytes;
3250 crtl->args.size = all.stack_args_size.constant;
3252 /* Adjust function incoming argument size for alignment and
3255 #ifdef REG_PARM_STACK_SPACE
3256 crtl->args.size = MAX (crtl->args.size,
3257 REG_PARM_STACK_SPACE (fndecl));
3260 crtl->args.size = CEIL_ROUND (crtl->args.size,
3261 PARM_BOUNDARY / BITS_PER_UNIT);
3263 #ifdef ARGS_GROW_DOWNWARD
3264 crtl->args.arg_offset_rtx
3265 = (all.stack_args_size.var == 0 ? GEN_INT (-all.stack_args_size.constant)
3266 : expand_expr (size_diffop (all.stack_args_size.var,
3267 size_int (-all.stack_args_size.constant)),
3268 NULL_RTX, VOIDmode, EXPAND_NORMAL));
3270 crtl->args.arg_offset_rtx = ARGS_SIZE_RTX (all.stack_args_size);
3273 /* See how many bytes, if any, of its args a function should try to pop
3276 crtl->args.pops_args = RETURN_POPS_ARGS (fndecl, TREE_TYPE (fndecl),
3279 /* For stdarg.h function, save info about
3280 regs and stack space used by the named args. */
3282 crtl->args.info = all.args_so_far;
3284 /* Set the rtx used for the function return value. Put this in its
3285 own variable so any optimizers that need this information don't have
3286 to include tree.h. Do this here so it gets done when an inlined
3287 function gets output. */
3290 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
3291 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
3293 /* If scalar return value was computed in a pseudo-reg, or was a named
3294 return value that got dumped to the stack, copy that to the hard
3296 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
3298 tree decl_result = DECL_RESULT (fndecl);
3299 rtx decl_rtl = DECL_RTL (decl_result);
3301 if (REG_P (decl_rtl)
3302 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
3303 : DECL_REGISTER (decl_result))
3307 real_decl_rtl = targetm.calls.function_value (TREE_TYPE (decl_result),
3309 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
3310 /* The delay slot scheduler assumes that crtl->return_rtx
3311 holds the hard register containing the return value, not a
3312 temporary pseudo. */
3313 crtl->return_rtx = real_decl_rtl;
3318 /* A subroutine of gimplify_parameters, invoked via walk_tree.
3319 For all seen types, gimplify their sizes. */
3322 gimplify_parm_type (tree *tp, int *walk_subtrees, void *data)
3329 if (POINTER_TYPE_P (t))
3331 else if (TYPE_SIZE (t) && !TREE_CONSTANT (TYPE_SIZE (t))
3332 && !TYPE_SIZES_GIMPLIFIED (t))
3334 gimplify_type_sizes (t, (gimple_seq *) data);
3342 /* Gimplify the parameter list for current_function_decl. This involves
3343 evaluating SAVE_EXPRs of variable sized parameters and generating code
3344 to implement callee-copies reference parameters. Returns a sequence of
3345 statements to add to the beginning of the function. */
3348 gimplify_parameters (void)
3350 struct assign_parm_data_all all;
3352 gimple_seq stmts = NULL;
3354 assign_parms_initialize_all (&all);
3355 fnargs = assign_parms_augmented_arg_list (&all);
3357 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
3359 struct assign_parm_data_one data;
3361 /* Extract the type of PARM; adjust it according to ABI. */
3362 assign_parm_find_data_types (&all, parm, &data);
3364 /* Early out for errors and void parameters. */
3365 if (data.passed_mode == VOIDmode || DECL_SIZE (parm) == NULL)
3368 /* Update info on where next arg arrives in registers. */
3369 FUNCTION_ARG_ADVANCE (all.args_so_far, data.promoted_mode,
3370 data.passed_type, data.named_arg);
3372 /* ??? Once upon a time variable_size stuffed parameter list
3373 SAVE_EXPRs (amongst others) onto a pending sizes list. This
3374 turned out to be less than manageable in the gimple world.
3375 Now we have to hunt them down ourselves. */
3376 walk_tree_without_duplicates (&data.passed_type,
3377 gimplify_parm_type, &stmts);
3379 if (TREE_CODE (DECL_SIZE_UNIT (parm)) != INTEGER_CST)
3381 gimplify_one_sizepos (&DECL_SIZE (parm), &stmts);
3382 gimplify_one_sizepos (&DECL_SIZE_UNIT (parm), &stmts);
3385 if (data.passed_pointer)
3387 tree type = TREE_TYPE (data.passed_type);
3388 if (reference_callee_copied (&all.args_so_far, TYPE_MODE (type),
3389 type, data.named_arg))
3393 /* For constant-sized objects, this is trivial; for
3394 variable-sized objects, we have to play games. */
3395 if (TREE_CODE (DECL_SIZE_UNIT (parm)) == INTEGER_CST
3396 && !(flag_stack_check == GENERIC_STACK_CHECK
3397 && compare_tree_int (DECL_SIZE_UNIT (parm),
3398 STACK_CHECK_MAX_VAR_SIZE) > 0))
3400 local = create_tmp_var (type, get_name (parm));
3401 DECL_IGNORED_P (local) = 0;
3402 /* If PARM was addressable, move that flag over
3403 to the local copy, as its address will be taken,
3405 if (TREE_ADDRESSABLE (parm))
3407 TREE_ADDRESSABLE (parm) = 0;
3408 TREE_ADDRESSABLE (local) = 1;
3413 tree ptr_type, addr;
3415 ptr_type = build_pointer_type (type);
3416 addr = create_tmp_var (ptr_type, get_name (parm));
3417 DECL_IGNORED_P (addr) = 0;
3418 local = build_fold_indirect_ref (addr);
3420 t = built_in_decls[BUILT_IN_ALLOCA];
3421 t = build_call_expr (t, 1, DECL_SIZE_UNIT (parm));
3422 t = fold_convert (ptr_type, t);
3423 t = build2 (MODIFY_EXPR, TREE_TYPE (addr), addr, t);
3424 gimplify_and_add (t, &stmts);
3427 gimplify_assign (local, parm, &stmts);
3429 SET_DECL_VALUE_EXPR (parm, local);
3430 DECL_HAS_VALUE_EXPR_P (parm) = 1;
3438 /* Compute the size and offset from the start of the stacked arguments for a
3439 parm passed in mode PASSED_MODE and with type TYPE.
3441 INITIAL_OFFSET_PTR points to the current offset into the stacked
3444 The starting offset and size for this parm are returned in
3445 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
3446 nonzero, the offset is that of stack slot, which is returned in
3447 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
3448 padding required from the initial offset ptr to the stack slot.
3450 IN_REGS is nonzero if the argument will be passed in registers. It will
3451 never be set if REG_PARM_STACK_SPACE is not defined.
3453 FNDECL is the function in which the argument was defined.
3455 There are two types of rounding that are done. The first, controlled by
3456 FUNCTION_ARG_BOUNDARY, forces the offset from the start of the argument
3457 list to be aligned to the specific boundary (in bits). This rounding
3458 affects the initial and starting offsets, but not the argument size.
3460 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
3461 optionally rounds the size of the parm to PARM_BOUNDARY. The
3462 initial offset is not affected by this rounding, while the size always
3463 is and the starting offset may be. */
3465 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
3466 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
3467 callers pass in the total size of args so far as
3468 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
3471 locate_and_pad_parm (enum machine_mode passed_mode, tree type, int in_regs,
3472 int partial, tree fndecl ATTRIBUTE_UNUSED,
3473 struct args_size *initial_offset_ptr,
3474 struct locate_and_pad_arg_data *locate)
3477 enum direction where_pad;
3478 unsigned int boundary;
3479 int reg_parm_stack_space = 0;
3480 int part_size_in_regs;
3482 #ifdef REG_PARM_STACK_SPACE
3483 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
3485 /* If we have found a stack parm before we reach the end of the
3486 area reserved for registers, skip that area. */
3489 if (reg_parm_stack_space > 0)
3491 if (initial_offset_ptr->var)
3493 initial_offset_ptr->var
3494 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
3495 ssize_int (reg_parm_stack_space));
3496 initial_offset_ptr->constant = 0;
3498 else if (initial_offset_ptr->constant < reg_parm_stack_space)
3499 initial_offset_ptr->constant = reg_parm_stack_space;
3502 #endif /* REG_PARM_STACK_SPACE */
3504 part_size_in_regs = (reg_parm_stack_space == 0 ? partial : 0);
3507 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
3508 where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
3509 boundary = FUNCTION_ARG_BOUNDARY (passed_mode, type);
3510 locate->where_pad = where_pad;
3512 /* Alignment can't exceed MAX_SUPPORTED_STACK_ALIGNMENT. */
3513 if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
3514 boundary = MAX_SUPPORTED_STACK_ALIGNMENT;
3516 locate->boundary = boundary;
3518 if (SUPPORTS_STACK_ALIGNMENT)
3520 /* stack_alignment_estimated can't change after stack has been
3522 if (crtl->stack_alignment_estimated < boundary)
3524 if (!crtl->stack_realign_processed)
3525 crtl->stack_alignment_estimated = boundary;
3528 /* If stack is realigned and stack alignment value
3529 hasn't been finalized, it is OK not to increase
3530 stack_alignment_estimated. The bigger alignment
3531 requirement is recorded in stack_alignment_needed
3533 gcc_assert (!crtl->stack_realign_finalized
3534 && crtl->stack_realign_needed);
3539 /* Remember if the outgoing parameter requires extra alignment on the
3540 calling function side. */
3541 if (crtl->stack_alignment_needed < boundary)
3542 crtl->stack_alignment_needed = boundary;
3543 if (crtl->preferred_stack_boundary < boundary)
3544 crtl->preferred_stack_boundary = boundary;
3546 #ifdef ARGS_GROW_DOWNWARD
3547 locate->slot_offset.constant = -initial_offset_ptr->constant;
3548 if (initial_offset_ptr->var)
3549 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
3550 initial_offset_ptr->var);
3554 if (where_pad != none
3555 && (!host_integerp (sizetree, 1)
3556 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
3557 s2 = round_up (s2, PARM_BOUNDARY / BITS_PER_UNIT);
3558 SUB_PARM_SIZE (locate->slot_offset, s2);
3561 locate->slot_offset.constant += part_size_in_regs;
3564 #ifdef REG_PARM_STACK_SPACE
3565 || REG_PARM_STACK_SPACE (fndecl) > 0
3568 pad_to_arg_alignment (&locate->slot_offset, boundary,
3569 &locate->alignment_pad);
3571 locate->size.constant = (-initial_offset_ptr->constant
3572 - locate->slot_offset.constant);
3573 if (initial_offset_ptr->var)
3574 locate->size.var = size_binop (MINUS_EXPR,
3575 size_binop (MINUS_EXPR,
3577 initial_offset_ptr->var),
3578 locate->slot_offset.var);
3580 /* Pad_below needs the pre-rounded size to know how much to pad
3582 locate->offset = locate->slot_offset;
3583 if (where_pad == downward)
3584 pad_below (&locate->offset, passed_mode, sizetree);
3586 #else /* !ARGS_GROW_DOWNWARD */
3588 #ifdef REG_PARM_STACK_SPACE
3589 || REG_PARM_STACK_SPACE (fndecl) > 0
3592 pad_to_arg_alignment (initial_offset_ptr, boundary,
3593 &locate->alignment_pad);
3594 locate->slot_offset = *initial_offset_ptr;
3596 #ifdef PUSH_ROUNDING
3597 if (passed_mode != BLKmode)
3598 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
3601 /* Pad_below needs the pre-rounded size to know how much to pad below
3602 so this must be done before rounding up. */
3603 locate->offset = locate->slot_offset;
3604 if (where_pad == downward)
3605 pad_below (&locate->offset, passed_mode, sizetree);
3607 if (where_pad != none
3608 && (!host_integerp (sizetree, 1)
3609 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
3610 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3612 ADD_PARM_SIZE (locate->size, sizetree);
3614 locate->size.constant -= part_size_in_regs;
3615 #endif /* ARGS_GROW_DOWNWARD */
3617 #ifdef FUNCTION_ARG_OFFSET
3618 locate->offset.constant += FUNCTION_ARG_OFFSET (passed_mode, type);
3622 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
3623 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
3626 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
3627 struct args_size *alignment_pad)
3629 tree save_var = NULL_TREE;
3630 HOST_WIDE_INT save_constant = 0;
3631 int boundary_in_bytes = boundary / BITS_PER_UNIT;
3632 HOST_WIDE_INT sp_offset = STACK_POINTER_OFFSET;
3634 #ifdef SPARC_STACK_BOUNDARY_HACK
3635 /* ??? The SPARC port may claim a STACK_BOUNDARY higher than
3636 the real alignment of %sp. However, when it does this, the
3637 alignment of %sp+STACK_POINTER_OFFSET is STACK_BOUNDARY. */
3638 if (SPARC_STACK_BOUNDARY_HACK)
3642 if (boundary > PARM_BOUNDARY)
3644 save_var = offset_ptr->var;
3645 save_constant = offset_ptr->constant;
3648 alignment_pad->var = NULL_TREE;
3649 alignment_pad->constant = 0;
3651 if (boundary > BITS_PER_UNIT)
3653 if (offset_ptr->var)
3655 tree sp_offset_tree = ssize_int (sp_offset);
3656 tree offset = size_binop (PLUS_EXPR,
3657 ARGS_SIZE_TREE (*offset_ptr),
3659 #ifdef ARGS_GROW_DOWNWARD
3660 tree rounded = round_down (offset, boundary / BITS_PER_UNIT);
3662 tree rounded = round_up (offset, boundary / BITS_PER_UNIT);
3665 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
3666 /* ARGS_SIZE_TREE includes constant term. */
3667 offset_ptr->constant = 0;
3668 if (boundary > PARM_BOUNDARY)
3669 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
3674 offset_ptr->constant = -sp_offset +
3675 #ifdef ARGS_GROW_DOWNWARD
3676 FLOOR_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
3678 CEIL_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
3680 if (boundary > PARM_BOUNDARY)
3681 alignment_pad->constant = offset_ptr->constant - save_constant;
3687 pad_below (struct args_size *offset_ptr, enum machine_mode passed_mode, tree sizetree)
3689 if (passed_mode != BLKmode)
3691 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
3692 offset_ptr->constant
3693 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
3694 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
3695 - GET_MODE_SIZE (passed_mode));
3699 if (TREE_CODE (sizetree) != INTEGER_CST
3700 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
3702 /* Round the size up to multiple of PARM_BOUNDARY bits. */
3703 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3705 ADD_PARM_SIZE (*offset_ptr, s2);
3706 SUB_PARM_SIZE (*offset_ptr, sizetree);
3712 /* True if register REGNO was alive at a place where `setjmp' was
3713 called and was set more than once or is an argument. Such regs may
3714 be clobbered by `longjmp'. */
3717 regno_clobbered_at_setjmp (bitmap setjmp_crosses, int regno)
3719 /* There appear to be cases where some local vars never reach the
3720 backend but have bogus regnos. */
3721 if (regno >= max_reg_num ())
3724 return ((REG_N_SETS (regno) > 1
3725 || REGNO_REG_SET_P (df_get_live_out (ENTRY_BLOCK_PTR), regno))
3726 && REGNO_REG_SET_P (setjmp_crosses, regno));
3729 /* Walk the tree of blocks describing the binding levels within a
3730 function and warn about variables the might be killed by setjmp or
3731 vfork. This is done after calling flow_analysis before register
3732 allocation since that will clobber the pseudo-regs to hard
3736 setjmp_vars_warning (bitmap setjmp_crosses, tree block)
3740 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
3742 if (TREE_CODE (decl) == VAR_DECL
3743 && DECL_RTL_SET_P (decl)
3744 && REG_P (DECL_RTL (decl))
3745 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
3746 warning (OPT_Wclobbered, "variable %q+D might be clobbered by"
3747 " %<longjmp%> or %<vfork%>", decl);
3750 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = BLOCK_CHAIN (sub))
3751 setjmp_vars_warning (setjmp_crosses, sub);
3754 /* Do the appropriate part of setjmp_vars_warning
3755 but for arguments instead of local variables. */
3758 setjmp_args_warning (bitmap setjmp_crosses)
3761 for (decl = DECL_ARGUMENTS (current_function_decl);
3762 decl; decl = TREE_CHAIN (decl))
3763 if (DECL_RTL (decl) != 0
3764 && REG_P (DECL_RTL (decl))
3765 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
3766 warning (OPT_Wclobbered,
3767 "argument %q+D might be clobbered by %<longjmp%> or %<vfork%>",
3771 /* Generate warning messages for variables live across setjmp. */
3774 generate_setjmp_warnings (void)
3776 bitmap setjmp_crosses = regstat_get_setjmp_crosses ();
3778 if (n_basic_blocks == NUM_FIXED_BLOCKS
3779 || bitmap_empty_p (setjmp_crosses))
3782 setjmp_vars_warning (setjmp_crosses, DECL_INITIAL (current_function_decl));
3783 setjmp_args_warning (setjmp_crosses);
3787 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
3788 and create duplicate blocks. */
3789 /* ??? Need an option to either create block fragments or to create
3790 abstract origin duplicates of a source block. It really depends
3791 on what optimization has been performed. */
3794 reorder_blocks (void)
3796 tree block = DECL_INITIAL (current_function_decl);
3797 VEC(tree,heap) *block_stack;
3799 if (block == NULL_TREE)
3802 block_stack = VEC_alloc (tree, heap, 10);
3804 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
3805 clear_block_marks (block);
3807 /* Prune the old trees away, so that they don't get in the way. */
3808 BLOCK_SUBBLOCKS (block) = NULL_TREE;
3809 BLOCK_CHAIN (block) = NULL_TREE;
3811 /* Recreate the block tree from the note nesting. */
3812 reorder_blocks_1 (get_insns (), block, &block_stack);
3813 BLOCK_SUBBLOCKS (block) = blocks_nreverse (BLOCK_SUBBLOCKS (block));
3815 VEC_free (tree, heap, block_stack);
3818 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
3821 clear_block_marks (tree block)
3825 TREE_ASM_WRITTEN (block) = 0;
3826 clear_block_marks (BLOCK_SUBBLOCKS (block));
3827 block = BLOCK_CHAIN (block);
3832 reorder_blocks_1 (rtx insns, tree current_block, VEC(tree,heap) **p_block_stack)
3836 for (insn = insns; insn; insn = NEXT_INSN (insn))
3840 if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_BEG)
3842 tree block = NOTE_BLOCK (insn);
3845 origin = (BLOCK_FRAGMENT_ORIGIN (block)
3846 ? BLOCK_FRAGMENT_ORIGIN (block)
3849 /* If we have seen this block before, that means it now
3850 spans multiple address regions. Create a new fragment. */
3851 if (TREE_ASM_WRITTEN (block))
3853 tree new_block = copy_node (block);
3855 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
3856 BLOCK_FRAGMENT_CHAIN (new_block)
3857 = BLOCK_FRAGMENT_CHAIN (origin);
3858 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
3860 NOTE_BLOCK (insn) = new_block;
3864 BLOCK_SUBBLOCKS (block) = 0;
3865 TREE_ASM_WRITTEN (block) = 1;
3866 /* When there's only one block for the entire function,
3867 current_block == block and we mustn't do this, it
3868 will cause infinite recursion. */
3869 if (block != current_block)
3871 if (block != origin)
3872 gcc_assert (BLOCK_SUPERCONTEXT (origin) == current_block);
3874 BLOCK_SUPERCONTEXT (block) = current_block;
3875 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
3876 BLOCK_SUBBLOCKS (current_block) = block;
3877 current_block = origin;
3879 VEC_safe_push (tree, heap, *p_block_stack, block);
3881 else if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_END)
3883 NOTE_BLOCK (insn) = VEC_pop (tree, *p_block_stack);
3884 BLOCK_SUBBLOCKS (current_block)
3885 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block));
3886 current_block = BLOCK_SUPERCONTEXT (current_block);
3892 /* Reverse the order of elements in the chain T of blocks,
3893 and return the new head of the chain (old last element). */
3896 blocks_nreverse (tree t)
3898 tree prev = 0, decl, next;
3899 for (decl = t; decl; decl = next)
3901 next = BLOCK_CHAIN (decl);
3902 BLOCK_CHAIN (decl) = prev;
3908 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
3909 non-NULL, list them all into VECTOR, in a depth-first preorder
3910 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
3914 all_blocks (tree block, tree *vector)
3920 TREE_ASM_WRITTEN (block) = 0;
3922 /* Record this block. */
3924 vector[n_blocks] = block;
3928 /* Record the subblocks, and their subblocks... */
3929 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
3930 vector ? vector + n_blocks : 0);
3931 block = BLOCK_CHAIN (block);
3937 /* Return a vector containing all the blocks rooted at BLOCK. The
3938 number of elements in the vector is stored in N_BLOCKS_P. The
3939 vector is dynamically allocated; it is the caller's responsibility
3940 to call `free' on the pointer returned. */
3943 get_block_vector (tree block, int *n_blocks_p)
3947 *n_blocks_p = all_blocks (block, NULL);
3948 block_vector = XNEWVEC (tree, *n_blocks_p);
3949 all_blocks (block, block_vector);
3951 return block_vector;
3954 static GTY(()) int next_block_index = 2;
3956 /* Set BLOCK_NUMBER for all the blocks in FN. */
3959 number_blocks (tree fn)
3965 /* For SDB and XCOFF debugging output, we start numbering the blocks
3966 from 1 within each function, rather than keeping a running
3968 #if defined (SDB_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
3969 if (write_symbols == SDB_DEBUG || write_symbols == XCOFF_DEBUG)
3970 next_block_index = 1;
3973 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
3975 /* The top-level BLOCK isn't numbered at all. */
3976 for (i = 1; i < n_blocks; ++i)
3977 /* We number the blocks from two. */
3978 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
3980 free (block_vector);
3985 /* If VAR is present in a subblock of BLOCK, return the subblock. */
3988 debug_find_var_in_block_tree (tree var, tree block)
3992 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
3996 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
3998 tree ret = debug_find_var_in_block_tree (var, t);
4006 /* Keep track of whether we're in a dummy function context. If we are,
4007 we don't want to invoke the set_current_function hook, because we'll
4008 get into trouble if the hook calls target_reinit () recursively or
4009 when the initial initialization is not yet complete. */
4011 static bool in_dummy_function;
4013 /* Invoke the target hook when setting cfun. Update the optimization options
4014 if the function uses different options than the default. */
4017 invoke_set_current_function_hook (tree fndecl)
4019 if (!in_dummy_function)
4021 tree opts = ((fndecl)
4022 ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (fndecl)
4023 : optimization_default_node);
4026 opts = optimization_default_node;
4028 /* Change optimization options if needed. */
4029 if (optimization_current_node != opts)
4031 optimization_current_node = opts;
4032 cl_optimization_restore (TREE_OPTIMIZATION (opts));
4035 targetm.set_current_function (fndecl);
4039 /* cfun should never be set directly; use this function. */
4042 set_cfun (struct function *new_cfun)
4044 if (cfun != new_cfun)
4047 invoke_set_current_function_hook (new_cfun ? new_cfun->decl : NULL_TREE);
4051 /* Initialized with NOGC, making this poisonous to the garbage collector. */
4053 static VEC(function_p,heap) *cfun_stack;
4055 /* Push the current cfun onto the stack, and set cfun to new_cfun. */
4058 push_cfun (struct function *new_cfun)
4060 VEC_safe_push (function_p, heap, cfun_stack, cfun);
4061 set_cfun (new_cfun);
4064 /* Pop cfun from the stack. */
4069 struct function *new_cfun = VEC_pop (function_p, cfun_stack);
4070 set_cfun (new_cfun);
4073 /* Return value of funcdef and increase it. */
4075 get_next_funcdef_no (void)
4077 return funcdef_no++;
4080 /* Allocate a function structure for FNDECL and set its contents
4081 to the defaults. Set cfun to the newly-allocated object.
4082 Some of the helper functions invoked during initialization assume
4083 that cfun has already been set. Therefore, assign the new object
4084 directly into cfun and invoke the back end hook explicitly at the
4085 very end, rather than initializing a temporary and calling set_cfun
4088 ABSTRACT_P is true if this is a function that will never be seen by
4089 the middle-end. Such functions are front-end concepts (like C++
4090 function templates) that do not correspond directly to functions
4091 placed in object files. */
4094 allocate_struct_function (tree fndecl, bool abstract_p)
4097 tree fntype = fndecl ? TREE_TYPE (fndecl) : NULL_TREE;
4099 cfun = GGC_CNEW (struct function);
4101 cfun->function_frequency = FUNCTION_FREQUENCY_NORMAL;
4103 init_eh_for_function ();
4105 if (init_machine_status)
4106 cfun->machine = (*init_machine_status) ();
4108 #ifdef OVERRIDE_ABI_FORMAT
4109 OVERRIDE_ABI_FORMAT (fndecl);
4112 invoke_set_current_function_hook (fndecl);
4114 if (fndecl != NULL_TREE)
4116 DECL_STRUCT_FUNCTION (fndecl) = cfun;
4117 cfun->decl = fndecl;
4118 current_function_funcdef_no = get_next_funcdef_no ();
4120 result = DECL_RESULT (fndecl);
4121 if (!abstract_p && aggregate_value_p (result, fndecl))
4123 #ifdef PCC_STATIC_STRUCT_RETURN
4124 cfun->returns_pcc_struct = 1;
4126 cfun->returns_struct = 1;
4131 && TYPE_ARG_TYPES (fntype) != 0
4132 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
4133 != void_type_node));
4135 /* Assume all registers in stdarg functions need to be saved. */
4136 cfun->va_list_gpr_size = VA_LIST_MAX_GPR_SIZE;
4137 cfun->va_list_fpr_size = VA_LIST_MAX_FPR_SIZE;
4141 /* This is like allocate_struct_function, but pushes a new cfun for FNDECL
4142 instead of just setting it. */
4145 push_struct_function (tree fndecl)
4147 VEC_safe_push (function_p, heap, cfun_stack, cfun);
4148 allocate_struct_function (fndecl, false);
4151 /* Reset cfun, and other non-struct-function variables to defaults as
4152 appropriate for emitting rtl at the start of a function. */
4155 prepare_function_start (void)
4157 gcc_assert (!crtl->emit.x_last_insn);
4160 init_varasm_status ();
4162 default_rtl_profile ();
4164 cse_not_expected = ! optimize;
4166 /* Caller save not needed yet. */
4167 caller_save_needed = 0;
4169 /* We haven't done register allocation yet. */
4172 /* Indicate that we have not instantiated virtual registers yet. */
4173 virtuals_instantiated = 0;
4175 /* Indicate that we want CONCATs now. */
4176 generating_concat_p = 1;
4178 /* Indicate we have no need of a frame pointer yet. */
4179 frame_pointer_needed = 0;
4182 /* Initialize the rtl expansion mechanism so that we can do simple things
4183 like generate sequences. This is used to provide a context during global
4184 initialization of some passes. You must call expand_dummy_function_end
4185 to exit this context. */
4188 init_dummy_function_start (void)
4190 gcc_assert (!in_dummy_function);
4191 in_dummy_function = true;
4192 push_struct_function (NULL_TREE);
4193 prepare_function_start ();
4196 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
4197 and initialize static variables for generating RTL for the statements
4201 init_function_start (tree subr)
4203 if (subr && DECL_STRUCT_FUNCTION (subr))
4204 set_cfun (DECL_STRUCT_FUNCTION (subr));
4206 allocate_struct_function (subr, false);
4207 prepare_function_start ();
4209 /* Warn if this value is an aggregate type,
4210 regardless of which calling convention we are using for it. */
4211 if (AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
4212 warning (OPT_Waggregate_return, "function returns an aggregate");
4215 /* Make sure all values used by the optimization passes have sane defaults. */
4217 init_function_for_compilation (void)
4223 struct rtl_opt_pass pass_init_function =
4229 init_function_for_compilation, /* execute */
4232 0, /* static_pass_number */
4233 TV_NONE, /* tv_id */
4234 0, /* properties_required */
4235 0, /* properties_provided */
4236 0, /* properties_destroyed */
4237 0, /* todo_flags_start */
4238 0 /* todo_flags_finish */
4244 expand_main_function (void)
4246 #if (defined(INVOKE__main) \
4247 || (!defined(HAS_INIT_SECTION) \
4248 && !defined(INIT_SECTION_ASM_OP) \
4249 && !defined(INIT_ARRAY_SECTION_ASM_OP)))
4250 emit_library_call (init_one_libfunc (NAME__MAIN), LCT_NORMAL, VOIDmode, 0);
4254 /* Expand code to initialize the stack_protect_guard. This is invoked at
4255 the beginning of a function to be protected. */
4257 #ifndef HAVE_stack_protect_set
4258 # define HAVE_stack_protect_set 0
4259 # define gen_stack_protect_set(x,y) (gcc_unreachable (), NULL_RTX)
4263 stack_protect_prologue (void)
4265 tree guard_decl = targetm.stack_protect_guard ();
4268 /* Avoid expand_expr here, because we don't want guard_decl pulled
4269 into registers unless absolutely necessary. And we know that
4270 crtl->stack_protect_guard is a local stack slot, so this skips
4272 x = validize_mem (DECL_RTL (crtl->stack_protect_guard));
4273 y = validize_mem (DECL_RTL (guard_decl));
4275 /* Allow the target to copy from Y to X without leaking Y into a
4277 if (HAVE_stack_protect_set)
4279 rtx insn = gen_stack_protect_set (x, y);
4287 /* Otherwise do a straight move. */
4288 emit_move_insn (x, y);
4291 /* Expand code to verify the stack_protect_guard. This is invoked at
4292 the end of a function to be protected. */
4294 #ifndef HAVE_stack_protect_test
4295 # define HAVE_stack_protect_test 0
4296 # define gen_stack_protect_test(x, y, z) (gcc_unreachable (), NULL_RTX)
4300 stack_protect_epilogue (void)
4302 tree guard_decl = targetm.stack_protect_guard ();
4303 rtx label = gen_label_rtx ();
4306 /* Avoid expand_expr here, because we don't want guard_decl pulled
4307 into registers unless absolutely necessary. And we know that
4308 crtl->stack_protect_guard is a local stack slot, so this skips
4310 x = validize_mem (DECL_RTL (crtl->stack_protect_guard));
4311 y = validize_mem (DECL_RTL (guard_decl));
4313 /* Allow the target to compare Y with X without leaking either into
4315 switch (HAVE_stack_protect_test != 0)
4318 tmp = gen_stack_protect_test (x, y, label);
4327 emit_cmp_and_jump_insns (x, y, EQ, NULL_RTX, ptr_mode, 1, label);
4331 /* The noreturn predictor has been moved to the tree level. The rtl-level
4332 predictors estimate this branch about 20%, which isn't enough to get
4333 things moved out of line. Since this is the only extant case of adding
4334 a noreturn function at the rtl level, it doesn't seem worth doing ought
4335 except adding the prediction by hand. */
4336 tmp = get_last_insn ();
4338 predict_insn_def (tmp, PRED_NORETURN, TAKEN);
4340 expand_expr_stmt (targetm.stack_protect_fail ());
4344 /* Start the RTL for a new function, and set variables used for
4346 SUBR is the FUNCTION_DECL node.
4347 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
4348 the function's parameters, which must be run at any return statement. */
4351 expand_function_start (tree subr)
4353 /* Make sure volatile mem refs aren't considered
4354 valid operands of arithmetic insns. */
4355 init_recog_no_volatile ();
4359 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
4362 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
4364 /* Make the label for return statements to jump to. Do not special
4365 case machines with special return instructions -- they will be
4366 handled later during jump, ifcvt, or epilogue creation. */
4367 return_label = gen_label_rtx ();
4369 /* Initialize rtx used to return the value. */
4370 /* Do this before assign_parms so that we copy the struct value address
4371 before any library calls that assign parms might generate. */
4373 /* Decide whether to return the value in memory or in a register. */
4374 if (aggregate_value_p (DECL_RESULT (subr), subr))
4376 /* Returning something that won't go in a register. */
4377 rtx value_address = 0;
4379 #ifdef PCC_STATIC_STRUCT_RETURN
4380 if (cfun->returns_pcc_struct)
4382 int size = int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr)));
4383 value_address = assemble_static_space (size);
4388 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 2);
4389 /* Expect to be passed the address of a place to store the value.
4390 If it is passed as an argument, assign_parms will take care of
4394 value_address = gen_reg_rtx (Pmode);
4395 emit_move_insn (value_address, sv);
4400 rtx x = value_address;
4401 if (!DECL_BY_REFERENCE (DECL_RESULT (subr)))
4403 x = gen_rtx_MEM (DECL_MODE (DECL_RESULT (subr)), x);
4404 set_mem_attributes (x, DECL_RESULT (subr), 1);
4406 SET_DECL_RTL (DECL_RESULT (subr), x);
4409 else if (DECL_MODE (DECL_RESULT (subr)) == VOIDmode)
4410 /* If return mode is void, this decl rtl should not be used. */
4411 SET_DECL_RTL (DECL_RESULT (subr), NULL_RTX);
4414 /* Compute the return values into a pseudo reg, which we will copy
4415 into the true return register after the cleanups are done. */
4416 tree return_type = TREE_TYPE (DECL_RESULT (subr));
4417 if (TYPE_MODE (return_type) != BLKmode
4418 && targetm.calls.return_in_msb (return_type))
4419 /* expand_function_end will insert the appropriate padding in
4420 this case. Use the return value's natural (unpadded) mode
4421 within the function proper. */
4422 SET_DECL_RTL (DECL_RESULT (subr),
4423 gen_reg_rtx (TYPE_MODE (return_type)));
4426 /* In order to figure out what mode to use for the pseudo, we
4427 figure out what the mode of the eventual return register will
4428 actually be, and use that. */
4429 rtx hard_reg = hard_function_value (return_type, subr, 0, 1);
4431 /* Structures that are returned in registers are not
4432 aggregate_value_p, so we may see a PARALLEL or a REG. */
4433 if (REG_P (hard_reg))
4434 SET_DECL_RTL (DECL_RESULT (subr),
4435 gen_reg_rtx (GET_MODE (hard_reg)));
4438 gcc_assert (GET_CODE (hard_reg) == PARALLEL);
4439 SET_DECL_RTL (DECL_RESULT (subr), gen_group_rtx (hard_reg));
4443 /* Set DECL_REGISTER flag so that expand_function_end will copy the
4444 result to the real return register(s). */
4445 DECL_REGISTER (DECL_RESULT (subr)) = 1;
4448 /* Initialize rtx for parameters and local variables.
4449 In some cases this requires emitting insns. */
4450 assign_parms (subr);
4452 /* If function gets a static chain arg, store it. */
4453 if (cfun->static_chain_decl)
4455 tree parm = cfun->static_chain_decl;
4456 rtx local = gen_reg_rtx (Pmode);
4458 set_decl_incoming_rtl (parm, static_chain_incoming_rtx, false);
4459 SET_DECL_RTL (parm, local);
4460 mark_reg_pointer (local, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
4462 emit_move_insn (local, static_chain_incoming_rtx);
4465 /* If the function receives a non-local goto, then store the
4466 bits we need to restore the frame pointer. */
4467 if (cfun->nonlocal_goto_save_area)
4472 /* ??? We need to do this save early. Unfortunately here is
4473 before the frame variable gets declared. Help out... */
4474 tree var = TREE_OPERAND (cfun->nonlocal_goto_save_area, 0);
4475 if (!DECL_RTL_SET_P (var))
4478 t_save = build4 (ARRAY_REF, ptr_type_node,
4479 cfun->nonlocal_goto_save_area,
4480 integer_zero_node, NULL_TREE, NULL_TREE);
4481 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
4482 r_save = convert_memory_address (Pmode, r_save);
4484 emit_move_insn (r_save, targetm.builtin_setjmp_frame_value ());
4485 update_nonlocal_goto_save_area ();
4488 /* The following was moved from init_function_start.
4489 The move is supposed to make sdb output more accurate. */
4490 /* Indicate the beginning of the function body,
4491 as opposed to parm setup. */
4492 emit_note (NOTE_INSN_FUNCTION_BEG);
4494 gcc_assert (NOTE_P (get_last_insn ()));
4496 parm_birth_insn = get_last_insn ();
4501 PROFILE_HOOK (current_function_funcdef_no);
4505 /* After the display initializations is where the stack checking
4507 if(flag_stack_check)
4508 stack_check_probe_note = emit_note (NOTE_INSN_DELETED);
4510 /* Make sure there is a line number after the function entry setup code. */
4511 force_next_line_note ();
4514 /* Undo the effects of init_dummy_function_start. */
4516 expand_dummy_function_end (void)
4518 gcc_assert (in_dummy_function);
4520 /* End any sequences that failed to be closed due to syntax errors. */
4521 while (in_sequence_p ())
4524 /* Outside function body, can't compute type's actual size
4525 until next function's body starts. */
4527 free_after_parsing (cfun);
4528 free_after_compilation (cfun);
4530 in_dummy_function = false;
4533 /* Call DOIT for each hard register used as a return value from
4534 the current function. */
4537 diddle_return_value (void (*doit) (rtx, void *), void *arg)
4539 rtx outgoing = crtl->return_rtx;
4544 if (REG_P (outgoing))
4545 (*doit) (outgoing, arg);
4546 else if (GET_CODE (outgoing) == PARALLEL)
4550 for (i = 0; i < XVECLEN (outgoing, 0); i++)
4552 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
4554 if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
4561 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
4567 clobber_return_register (void)
4569 diddle_return_value (do_clobber_return_reg, NULL);
4571 /* In case we do use pseudo to return value, clobber it too. */
4572 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
4574 tree decl_result = DECL_RESULT (current_function_decl);
4575 rtx decl_rtl = DECL_RTL (decl_result);
4576 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
4578 do_clobber_return_reg (decl_rtl, NULL);
4584 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
4590 use_return_register (void)
4592 diddle_return_value (do_use_return_reg, NULL);
4595 /* Possibly warn about unused parameters. */
4597 do_warn_unused_parameter (tree fn)
4601 for (decl = DECL_ARGUMENTS (fn);
4602 decl; decl = TREE_CHAIN (decl))
4603 if (!TREE_USED (decl) && TREE_CODE (decl) == PARM_DECL
4604 && DECL_NAME (decl) && !DECL_ARTIFICIAL (decl)
4605 && !TREE_NO_WARNING (decl))
4606 warning (OPT_Wunused_parameter, "unused parameter %q+D", decl);
4609 static GTY(()) rtx initial_trampoline;
4611 /* Generate RTL for the end of the current function. */
4614 expand_function_end (void)
4618 /* If arg_pointer_save_area was referenced only from a nested
4619 function, we will not have initialized it yet. Do that now. */
4620 if (arg_pointer_save_area && ! crtl->arg_pointer_save_area_init)
4621 get_arg_pointer_save_area ();
4623 /* If we are doing generic stack checking and this function makes calls,
4624 do a stack probe at the start of the function to ensure we have enough
4625 space for another stack frame. */
4626 if (flag_stack_check == GENERIC_STACK_CHECK)
4630 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
4634 probe_stack_range (STACK_OLD_CHECK_PROTECT,
4635 GEN_INT (STACK_CHECK_MAX_FRAME_SIZE));
4638 emit_insn_before (seq, stack_check_probe_note);
4643 /* End any sequences that failed to be closed due to syntax errors. */
4644 while (in_sequence_p ())
4647 clear_pending_stack_adjust ();
4648 do_pending_stack_adjust ();
4650 /* Output a linenumber for the end of the function.
4651 SDB depends on this. */
4652 force_next_line_note ();
4653 set_curr_insn_source_location (input_location);
4655 /* Before the return label (if any), clobber the return
4656 registers so that they are not propagated live to the rest of
4657 the function. This can only happen with functions that drop
4658 through; if there had been a return statement, there would
4659 have either been a return rtx, or a jump to the return label.
4661 We delay actual code generation after the current_function_value_rtx
4663 clobber_after = get_last_insn ();
4665 /* Output the label for the actual return from the function. */
4666 emit_label (return_label);
4668 if (USING_SJLJ_EXCEPTIONS)
4670 /* Let except.c know where it should emit the call to unregister
4671 the function context for sjlj exceptions. */
4672 if (flag_exceptions)
4673 sjlj_emit_function_exit_after (get_last_insn ());
4677 /* We want to ensure that instructions that may trap are not
4678 moved into the epilogue by scheduling, because we don't
4679 always emit unwind information for the epilogue. */
4680 if (flag_non_call_exceptions)
4681 emit_insn (gen_blockage ());
4684 /* If this is an implementation of throw, do what's necessary to
4685 communicate between __builtin_eh_return and the epilogue. */
4686 expand_eh_return ();
4688 /* If scalar return value was computed in a pseudo-reg, or was a named
4689 return value that got dumped to the stack, copy that to the hard
4691 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
4693 tree decl_result = DECL_RESULT (current_function_decl);
4694 rtx decl_rtl = DECL_RTL (decl_result);
4696 if (REG_P (decl_rtl)
4697 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
4698 : DECL_REGISTER (decl_result))
4700 rtx real_decl_rtl = crtl->return_rtx;
4702 /* This should be set in assign_parms. */
4703 gcc_assert (REG_FUNCTION_VALUE_P (real_decl_rtl));
4705 /* If this is a BLKmode structure being returned in registers,
4706 then use the mode computed in expand_return. Note that if
4707 decl_rtl is memory, then its mode may have been changed,
4708 but that crtl->return_rtx has not. */
4709 if (GET_MODE (real_decl_rtl) == BLKmode)
4710 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
4712 /* If a non-BLKmode return value should be padded at the least
4713 significant end of the register, shift it left by the appropriate
4714 amount. BLKmode results are handled using the group load/store
4716 if (TYPE_MODE (TREE_TYPE (decl_result)) != BLKmode
4717 && targetm.calls.return_in_msb (TREE_TYPE (decl_result)))
4719 emit_move_insn (gen_rtx_REG (GET_MODE (decl_rtl),
4720 REGNO (real_decl_rtl)),
4722 shift_return_value (GET_MODE (decl_rtl), true, real_decl_rtl);
4724 /* If a named return value dumped decl_return to memory, then
4725 we may need to re-do the PROMOTE_MODE signed/unsigned
4727 else if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
4729 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
4730 promote_function_mode (TREE_TYPE (decl_result),
4731 GET_MODE (decl_rtl), &unsignedp,
4732 TREE_TYPE (current_function_decl), 1);
4734 convert_move (real_decl_rtl, decl_rtl, unsignedp);
4736 else if (GET_CODE (real_decl_rtl) == PARALLEL)
4738 /* If expand_function_start has created a PARALLEL for decl_rtl,
4739 move the result to the real return registers. Otherwise, do
4740 a group load from decl_rtl for a named return. */
4741 if (GET_CODE (decl_rtl) == PARALLEL)
4742 emit_group_move (real_decl_rtl, decl_rtl);
4744 emit_group_load (real_decl_rtl, decl_rtl,
4745 TREE_TYPE (decl_result),
4746 int_size_in_bytes (TREE_TYPE (decl_result)));
4748 /* In the case of complex integer modes smaller than a word, we'll
4749 need to generate some non-trivial bitfield insertions. Do that
4750 on a pseudo and not the hard register. */
4751 else if (GET_CODE (decl_rtl) == CONCAT
4752 && GET_MODE_CLASS (GET_MODE (decl_rtl)) == MODE_COMPLEX_INT
4753 && GET_MODE_BITSIZE (GET_MODE (decl_rtl)) <= BITS_PER_WORD)
4755 int old_generating_concat_p;
4758 old_generating_concat_p = generating_concat_p;
4759 generating_concat_p = 0;
4760 tmp = gen_reg_rtx (GET_MODE (decl_rtl));
4761 generating_concat_p = old_generating_concat_p;
4763 emit_move_insn (tmp, decl_rtl);
4764 emit_move_insn (real_decl_rtl, tmp);
4767 emit_move_insn (real_decl_rtl, decl_rtl);
4771 /* If returning a structure, arrange to return the address of the value
4772 in a place where debuggers expect to find it.
4774 If returning a structure PCC style,
4775 the caller also depends on this value.
4776 And cfun->returns_pcc_struct is not necessarily set. */
4777 if (cfun->returns_struct
4778 || cfun->returns_pcc_struct)
4780 rtx value_address = DECL_RTL (DECL_RESULT (current_function_decl));
4781 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
4784 if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
4785 type = TREE_TYPE (type);
4787 value_address = XEXP (value_address, 0);
4789 outgoing = targetm.calls.function_value (build_pointer_type (type),
4790 current_function_decl, true);
4792 /* Mark this as a function return value so integrate will delete the
4793 assignment and USE below when inlining this function. */
4794 REG_FUNCTION_VALUE_P (outgoing) = 1;
4796 /* The address may be ptr_mode and OUTGOING may be Pmode. */
4797 value_address = convert_memory_address (GET_MODE (outgoing),
4800 emit_move_insn (outgoing, value_address);
4802 /* Show return register used to hold result (in this case the address
4804 crtl->return_rtx = outgoing;
4807 /* Emit the actual code to clobber return register. */
4812 clobber_return_register ();
4816 emit_insn_after (seq, clobber_after);
4819 /* Output the label for the naked return from the function. */
4820 if (naked_return_label)
4821 emit_label (naked_return_label);
4823 /* @@@ This is a kludge. We want to ensure that instructions that
4824 may trap are not moved into the epilogue by scheduling, because
4825 we don't always emit unwind information for the epilogue. */
4826 if (! USING_SJLJ_EXCEPTIONS && flag_non_call_exceptions)
4827 emit_insn (gen_blockage ());
4829 /* If stack protection is enabled for this function, check the guard. */
4830 if (crtl->stack_protect_guard)
4831 stack_protect_epilogue ();
4833 /* If we had calls to alloca, and this machine needs
4834 an accurate stack pointer to exit the function,
4835 insert some code to save and restore the stack pointer. */
4836 if (! EXIT_IGNORE_STACK
4837 && cfun->calls_alloca)
4841 emit_stack_save (SAVE_FUNCTION, &tem, parm_birth_insn);
4842 emit_stack_restore (SAVE_FUNCTION, tem, NULL_RTX);
4845 /* ??? This should no longer be necessary since stupid is no longer with
4846 us, but there are some parts of the compiler (eg reload_combine, and
4847 sh mach_dep_reorg) that still try and compute their own lifetime info
4848 instead of using the general framework. */
4849 use_return_register ();
4853 get_arg_pointer_save_area (void)
4855 rtx ret = arg_pointer_save_area;
4859 ret = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
4860 arg_pointer_save_area = ret;
4863 if (! crtl->arg_pointer_save_area_init)
4867 /* Save the arg pointer at the beginning of the function. The
4868 generated stack slot may not be a valid memory address, so we
4869 have to check it and fix it if necessary. */
4871 emit_move_insn (validize_mem (ret),
4872 crtl->args.internal_arg_pointer);
4876 push_topmost_sequence ();
4877 emit_insn_after (seq, entry_of_function ());
4878 pop_topmost_sequence ();
4884 /* Add a list of INSNS to the hash HASHP, possibly allocating HASHP
4885 for the first time. */
4888 record_insns (rtx insns, rtx end, htab_t *hashp)
4891 htab_t hash = *hashp;
4895 = htab_create_ggc (17, htab_hash_pointer, htab_eq_pointer, NULL);
4897 for (tmp = insns; tmp != end; tmp = NEXT_INSN (tmp))
4899 void **slot = htab_find_slot (hash, tmp, INSERT);
4900 gcc_assert (*slot == NULL);
4905 /* INSN has been duplicated as COPY, as part of duping a basic block.
4906 If INSN is an epilogue insn, then record COPY as epilogue as well. */
4909 maybe_copy_epilogue_insn (rtx insn, rtx copy)
4913 if (epilogue_insn_hash == NULL
4914 || htab_find (epilogue_insn_hash, insn) == NULL)
4917 slot = htab_find_slot (epilogue_insn_hash, copy, INSERT);
4918 gcc_assert (*slot == NULL);
4922 /* Set the locator of the insn chain starting at INSN to LOC. */
4924 set_insn_locators (rtx insn, int loc)
4926 while (insn != NULL_RTX)
4929 INSN_LOCATOR (insn) = loc;
4930 insn = NEXT_INSN (insn);
4934 /* Determine if any INSNs in HASH are, or are part of, INSN. Because
4935 we can be running after reorg, SEQUENCE rtl is possible. */
4938 contains (const_rtx insn, htab_t hash)
4943 if (NONJUMP_INSN_P (insn) && GET_CODE (PATTERN (insn)) == SEQUENCE)
4946 for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
4947 if (htab_find (hash, XVECEXP (PATTERN (insn), 0, i)))
4952 return htab_find (hash, insn) != NULL;
4956 prologue_epilogue_contains (const_rtx insn)
4958 if (contains (insn, prologue_insn_hash))
4960 if (contains (insn, epilogue_insn_hash))
4966 /* Insert gen_return at the end of block BB. This also means updating
4967 block_for_insn appropriately. */
4970 emit_return_into_block (basic_block bb)
4972 emit_jump_insn_after (gen_return (), BB_END (bb));
4974 #endif /* HAVE_return */
4976 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
4977 this into place with notes indicating where the prologue ends and where
4978 the epilogue begins. Update the basic block information when possible. */
4981 thread_prologue_and_epilogue_insns (void)
4985 #if defined (HAVE_sibcall_epilogue) || defined (HAVE_epilogue) || defined (HAVE_return) || defined (HAVE_prologue)
4988 #if defined (HAVE_epilogue) || defined(HAVE_return)
4989 rtx epilogue_end = NULL_RTX;
4993 rtl_profile_for_bb (ENTRY_BLOCK_PTR);
4994 #ifdef HAVE_prologue
4998 seq = gen_prologue ();
5001 /* Insert an explicit USE for the frame pointer
5002 if the profiling is on and the frame pointer is required. */
5003 if (crtl->profile && frame_pointer_needed)
5004 emit_use (hard_frame_pointer_rtx);
5006 /* Retain a map of the prologue insns. */
5007 record_insns (seq, NULL, &prologue_insn_hash);
5008 emit_note (NOTE_INSN_PROLOGUE_END);
5010 #ifndef PROFILE_BEFORE_PROLOGUE
5011 /* Ensure that instructions are not moved into the prologue when
5012 profiling is on. The call to the profiling routine can be
5013 emitted within the live range of a call-clobbered register. */
5015 emit_insn (gen_blockage ());
5020 set_insn_locators (seq, prologue_locator);
5022 /* Can't deal with multiple successors of the entry block
5023 at the moment. Function should always have at least one
5025 gcc_assert (single_succ_p (ENTRY_BLOCK_PTR));
5027 insert_insn_on_edge (seq, single_succ_edge (ENTRY_BLOCK_PTR));
5032 /* If the exit block has no non-fake predecessors, we don't need
5034 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5035 if ((e->flags & EDGE_FAKE) == 0)
5040 rtl_profile_for_bb (EXIT_BLOCK_PTR);
5042 if (optimize && HAVE_return)
5044 /* If we're allowed to generate a simple return instruction,
5045 then by definition we don't need a full epilogue. Examine
5046 the block that falls through to EXIT. If it does not
5047 contain any code, examine its predecessors and try to
5048 emit (conditional) return instructions. */
5053 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5054 if (e->flags & EDGE_FALLTHRU)
5060 /* Verify that there are no active instructions in the last block. */
5061 label = BB_END (last);
5062 while (label && !LABEL_P (label))
5064 if (active_insn_p (label))
5066 label = PREV_INSN (label);
5069 if (BB_HEAD (last) == label && LABEL_P (label))
5073 for (ei2 = ei_start (last->preds); (e = ei_safe_edge (ei2)); )
5075 basic_block bb = e->src;
5078 if (bb == ENTRY_BLOCK_PTR)
5085 if (!JUMP_P (jump) || JUMP_LABEL (jump) != label)
5091 /* If we have an unconditional jump, we can replace that
5092 with a simple return instruction. */
5093 if (simplejump_p (jump))
5095 emit_return_into_block (bb);
5099 /* If we have a conditional jump, we can try to replace
5100 that with a conditional return instruction. */
5101 else if (condjump_p (jump))
5103 if (! redirect_jump (jump, 0, 0))
5109 /* If this block has only one successor, it both jumps
5110 and falls through to the fallthru block, so we can't
5112 if (single_succ_p (bb))
5124 /* Fix up the CFG for the successful change we just made. */
5125 redirect_edge_succ (e, EXIT_BLOCK_PTR);
5128 /* Emit a return insn for the exit fallthru block. Whether
5129 this is still reachable will be determined later. */
5131 emit_barrier_after (BB_END (last));
5132 emit_return_into_block (last);
5133 epilogue_end = BB_END (last);
5134 single_succ_edge (last)->flags &= ~EDGE_FALLTHRU;
5140 /* A small fib -- epilogue is not yet completed, but we wish to re-use
5141 this marker for the splits of EH_RETURN patterns, and nothing else
5142 uses the flag in the meantime. */
5143 epilogue_completed = 1;
5145 #ifdef HAVE_eh_return
5146 /* Find non-fallthru edges that end with EH_RETURN instructions. On
5147 some targets, these get split to a special version of the epilogue
5148 code. In order to be able to properly annotate these with unwind
5149 info, try to split them now. If we get a valid split, drop an
5150 EPILOGUE_BEG note and mark the insns as epilogue insns. */
5151 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5153 rtx prev, last, trial;
5155 if (e->flags & EDGE_FALLTHRU)
5157 last = BB_END (e->src);
5158 if (!eh_returnjump_p (last))
5161 prev = PREV_INSN (last);
5162 trial = try_split (PATTERN (last), last, 1);
5166 record_insns (NEXT_INSN (prev), NEXT_INSN (trial), &epilogue_insn_hash);
5167 emit_note_after (NOTE_INSN_EPILOGUE_BEG, prev);
5171 /* Find the edge that falls through to EXIT. Other edges may exist
5172 due to RETURN instructions, but those don't need epilogues.
5173 There really shouldn't be a mixture -- either all should have
5174 been converted or none, however... */
5176 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5177 if (e->flags & EDGE_FALLTHRU)
5182 #ifdef HAVE_epilogue
5186 epilogue_end = emit_note (NOTE_INSN_EPILOGUE_BEG);
5187 seq = gen_epilogue ();
5188 emit_jump_insn (seq);
5190 /* Retain a map of the epilogue insns. */
5191 record_insns (seq, NULL, &epilogue_insn_hash);
5192 set_insn_locators (seq, epilogue_locator);
5197 insert_insn_on_edge (seq, e);
5205 if (! next_active_insn (BB_END (e->src)))
5207 /* We have a fall-through edge to the exit block, the source is not
5208 at the end of the function, and there will be an assembler epilogue
5209 at the end of the function.
5210 We can't use force_nonfallthru here, because that would try to
5211 use return. Inserting a jump 'by hand' is extremely messy, so
5212 we take advantage of cfg_layout_finalize using
5213 fixup_fallthru_exit_predecessor. */
5214 cfg_layout_initialize (0);
5215 FOR_EACH_BB (cur_bb)
5216 if (cur_bb->index >= NUM_FIXED_BLOCKS
5217 && cur_bb->next_bb->index >= NUM_FIXED_BLOCKS)
5218 cur_bb->aux = cur_bb->next_bb;
5219 cfg_layout_finalize ();
5222 default_rtl_profile ();
5226 commit_edge_insertions ();
5228 /* The epilogue insns we inserted may cause the exit edge to no longer
5230 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5232 if (((e->flags & EDGE_FALLTHRU) != 0)
5233 && returnjump_p (BB_END (e->src)))
5234 e->flags &= ~EDGE_FALLTHRU;
5238 #ifdef HAVE_sibcall_epilogue
5239 /* Emit sibling epilogues before any sibling call sites. */
5240 for (ei = ei_start (EXIT_BLOCK_PTR->preds); (e = ei_safe_edge (ei)); )
5242 basic_block bb = e->src;
5243 rtx insn = BB_END (bb);
5246 || ! SIBLING_CALL_P (insn))
5253 emit_note (NOTE_INSN_EPILOGUE_BEG);
5254 emit_insn (gen_sibcall_epilogue ());
5258 /* Retain a map of the epilogue insns. Used in life analysis to
5259 avoid getting rid of sibcall epilogue insns. Do this before we
5260 actually emit the sequence. */
5261 record_insns (seq, NULL, &epilogue_insn_hash);
5262 set_insn_locators (seq, epilogue_locator);
5264 emit_insn_before (seq, insn);
5269 #ifdef HAVE_epilogue
5274 /* Similarly, move any line notes that appear after the epilogue.
5275 There is no need, however, to be quite so anal about the existence
5276 of such a note. Also possibly move
5277 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
5279 for (insn = epilogue_end; insn; insn = next)
5281 next = NEXT_INSN (insn);
5283 && (NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG))
5284 reorder_insns (insn, insn, PREV_INSN (epilogue_end));
5289 /* Threading the prologue and epilogue changes the artificial refs
5290 in the entry and exit blocks. */
5291 epilogue_completed = 1;
5292 df_update_entry_exit_and_calls ();
5295 /* Reposition the prologue-end and epilogue-begin notes after
5296 instruction scheduling. */
5299 reposition_prologue_and_epilogue_notes (void)
5301 #if defined (HAVE_prologue) || defined (HAVE_epilogue) \
5302 || defined (HAVE_sibcall_epilogue)
5303 /* Since the hash table is created on demand, the fact that it is
5304 non-null is a signal that it is non-empty. */
5305 if (prologue_insn_hash != NULL)
5307 size_t len = htab_elements (prologue_insn_hash);
5308 rtx insn, last = NULL, note = NULL;
5310 /* Scan from the beginning until we reach the last prologue insn. */
5311 /* ??? While we do have the CFG intact, there are two problems:
5312 (1) The prologue can contain loops (typically probing the stack),
5313 which means that the end of the prologue isn't in the first bb.
5314 (2) Sometimes the PROLOGUE_END note gets pushed into the next bb. */
5315 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
5319 if (NOTE_KIND (insn) == NOTE_INSN_PROLOGUE_END)
5322 else if (contains (insn, prologue_insn_hash))
5334 /* Scan forward looking for the PROLOGUE_END note. It should
5335 be right at the beginning of the block, possibly with other
5336 insn notes that got moved there. */
5337 for (note = NEXT_INSN (last); ; note = NEXT_INSN (note))
5340 && NOTE_KIND (note) == NOTE_INSN_PROLOGUE_END)
5345 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
5347 last = NEXT_INSN (last);
5348 reorder_insns (note, note, last);
5352 if (epilogue_insn_hash != NULL)
5357 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5359 rtx insn, first = NULL, note = NULL;
5360 basic_block bb = e->src;
5362 /* Scan from the beginning until we reach the first epilogue insn. */
5363 FOR_BB_INSNS (bb, insn)
5367 if (NOTE_KIND (insn) == NOTE_INSN_EPILOGUE_BEG)
5374 else if (first == NULL && contains (insn, epilogue_insn_hash))
5384 /* If the function has a single basic block, and no real
5385 epilogue insns (e.g. sibcall with no cleanup), the
5386 epilogue note can get scheduled before the prologue
5387 note. If we have frame related prologue insns, having
5388 them scanned during the epilogue will result in a crash.
5389 In this case re-order the epilogue note to just before
5390 the last insn in the block. */
5392 first = BB_END (bb);
5394 if (PREV_INSN (first) != note)
5395 reorder_insns (note, note, PREV_INSN (first));
5399 #endif /* HAVE_prologue or HAVE_epilogue */
5402 /* Returns the name of the current function. */
5404 current_function_name (void)
5406 return lang_hooks.decl_printable_name (cfun->decl, 2);
5411 rest_of_handle_check_leaf_regs (void)
5413 #ifdef LEAF_REGISTERS
5414 current_function_uses_only_leaf_regs
5415 = optimize > 0 && only_leaf_regs_used () && leaf_function_p ();
5420 /* Insert a TYPE into the used types hash table of CFUN. */
5422 used_types_insert_helper (tree type, struct function *func)
5424 if (type != NULL && func != NULL)
5428 if (func->used_types_hash == NULL)
5429 func->used_types_hash = htab_create_ggc (37, htab_hash_pointer,
5430 htab_eq_pointer, NULL);
5431 slot = htab_find_slot (func->used_types_hash, type, INSERT);
5437 /* Given a type, insert it into the used hash table in cfun. */
5439 used_types_insert (tree t)
5441 while (POINTER_TYPE_P (t) || TREE_CODE (t) == ARRAY_TYPE)
5443 t = TYPE_MAIN_VARIANT (t);
5444 if (debug_info_level > DINFO_LEVEL_NONE)
5445 used_types_insert_helper (t, cfun);
5448 struct rtl_opt_pass pass_leaf_regs =
5454 rest_of_handle_check_leaf_regs, /* execute */
5457 0, /* static_pass_number */
5458 TV_NONE, /* tv_id */
5459 0, /* properties_required */
5460 0, /* properties_provided */
5461 0, /* properties_destroyed */
5462 0, /* todo_flags_start */
5463 0 /* todo_flags_finish */
5468 rest_of_handle_thread_prologue_and_epilogue (void)
5471 cleanup_cfg (CLEANUP_EXPENSIVE);
5472 /* On some machines, the prologue and epilogue code, or parts thereof,
5473 can be represented as RTL. Doing so lets us schedule insns between
5474 it and the rest of the code and also allows delayed branch
5475 scheduling to operate in the epilogue. */
5477 thread_prologue_and_epilogue_insns ();
5481 struct rtl_opt_pass pass_thread_prologue_and_epilogue =
5485 "pro_and_epilogue", /* name */
5487 rest_of_handle_thread_prologue_and_epilogue, /* execute */
5490 0, /* static_pass_number */
5491 TV_THREAD_PROLOGUE_AND_EPILOGUE, /* tv_id */
5492 0, /* properties_required */
5493 0, /* properties_provided */
5494 0, /* properties_destroyed */
5495 TODO_verify_flow, /* todo_flags_start */
5498 TODO_df_finish | TODO_verify_rtl_sharing |
5499 TODO_ggc_collect /* todo_flags_finish */
5504 /* This mini-pass fixes fall-out from SSA in asm statements that have
5505 in-out constraints. Say you start with
5508 asm ("": "+mr" (inout));
5511 which is transformed very early to use explicit output and match operands:
5514 asm ("": "=mr" (inout) : "0" (inout));
5517 Or, after SSA and copyprop,
5519 asm ("": "=mr" (inout_2) : "0" (inout_1));
5522 Clearly inout_2 and inout_1 can't be coalesced easily anymore, as
5523 they represent two separate values, so they will get different pseudo
5524 registers during expansion. Then, since the two operands need to match
5525 per the constraints, but use different pseudo registers, reload can
5526 only register a reload for these operands. But reloads can only be
5527 satisfied by hardregs, not by memory, so we need a register for this
5528 reload, just because we are presented with non-matching operands.
5529 So, even though we allow memory for this operand, no memory can be
5530 used for it, just because the two operands don't match. This can
5531 cause reload failures on register-starved targets.
5533 So it's a symptom of reload not being able to use memory for reloads
5534 or, alternatively it's also a symptom of both operands not coming into
5535 reload as matching (in which case the pseudo could go to memory just
5536 fine, as the alternative allows it, and no reload would be necessary).
5537 We fix the latter problem here, by transforming
5539 asm ("": "=mr" (inout_2) : "0" (inout_1));
5544 asm ("": "=mr" (inout_2) : "0" (inout_2)); */
5547 match_asm_constraints_1 (rtx insn, rtx *p_sets, int noutputs)
5550 bool changed = false;
5551 rtx op = SET_SRC (p_sets[0]);
5552 int ninputs = ASM_OPERANDS_INPUT_LENGTH (op);
5553 rtvec inputs = ASM_OPERANDS_INPUT_VEC (op);
5554 bool *output_matched = XALLOCAVEC (bool, noutputs);
5556 memset (output_matched, 0, noutputs * sizeof (bool));
5557 for (i = 0; i < ninputs; i++)
5559 rtx input, output, insns;
5560 const char *constraint = ASM_OPERANDS_INPUT_CONSTRAINT (op, i);
5564 if (*constraint == '%')
5567 match = strtoul (constraint, &end, 10);
5568 if (end == constraint)
5571 gcc_assert (match < noutputs);
5572 output = SET_DEST (p_sets[match]);
5573 input = RTVEC_ELT (inputs, i);
5574 /* Only do the transformation for pseudos. */
5575 if (! REG_P (output)
5576 || rtx_equal_p (output, input)
5577 || (GET_MODE (input) != VOIDmode
5578 && GET_MODE (input) != GET_MODE (output)))
5581 /* We can't do anything if the output is also used as input,
5582 as we're going to overwrite it. */
5583 for (j = 0; j < ninputs; j++)
5584 if (reg_overlap_mentioned_p (output, RTVEC_ELT (inputs, j)))
5589 /* Avoid changing the same input several times. For
5590 asm ("" : "=mr" (out1), "=mr" (out2) : "0" (in), "1" (in));
5591 only change in once (to out1), rather than changing it
5592 first to out1 and afterwards to out2. */
5595 for (j = 0; j < noutputs; j++)
5596 if (output_matched[j] && input == SET_DEST (p_sets[j]))
5601 output_matched[match] = true;
5604 emit_move_insn (output, input);
5605 insns = get_insns ();
5607 emit_insn_before (insns, insn);
5609 /* Now replace all mentions of the input with output. We can't
5610 just replace the occurrence in inputs[i], as the register might
5611 also be used in some other input (or even in an address of an
5612 output), which would mean possibly increasing the number of
5613 inputs by one (namely 'output' in addition), which might pose
5614 a too complicated problem for reload to solve. E.g. this situation:
5616 asm ("" : "=r" (output), "=m" (input) : "0" (input))
5618 Here 'input' is used in two occurrences as input (once for the
5619 input operand, once for the address in the second output operand).
5620 If we would replace only the occurrence of the input operand (to
5621 make the matching) we would be left with this:
5624 asm ("" : "=r" (output), "=m" (input) : "0" (output))
5626 Now we suddenly have two different input values (containing the same
5627 value, but different pseudos) where we formerly had only one.
5628 With more complicated asms this might lead to reload failures
5629 which wouldn't have happen without this pass. So, iterate over
5630 all operands and replace all occurrences of the register used. */
5631 for (j = 0; j < noutputs; j++)
5632 if (!rtx_equal_p (SET_DEST (p_sets[j]), input)
5633 && reg_overlap_mentioned_p (input, SET_DEST (p_sets[j])))
5634 SET_DEST (p_sets[j]) = replace_rtx (SET_DEST (p_sets[j]),
5636 for (j = 0; j < ninputs; j++)
5637 if (reg_overlap_mentioned_p (input, RTVEC_ELT (inputs, j)))
5638 RTVEC_ELT (inputs, j) = replace_rtx (RTVEC_ELT (inputs, j),
5645 df_insn_rescan (insn);
5649 rest_of_match_asm_constraints (void)
5652 rtx insn, pat, *p_sets;
5655 if (!crtl->has_asm_statement)
5658 df_set_flags (DF_DEFER_INSN_RESCAN);
5661 FOR_BB_INSNS (bb, insn)
5666 pat = PATTERN (insn);
5667 if (GET_CODE (pat) == PARALLEL)
5668 p_sets = &XVECEXP (pat, 0, 0), noutputs = XVECLEN (pat, 0);
5669 else if (GET_CODE (pat) == SET)
5670 p_sets = &PATTERN (insn), noutputs = 1;
5674 if (GET_CODE (*p_sets) == SET
5675 && GET_CODE (SET_SRC (*p_sets)) == ASM_OPERANDS)
5676 match_asm_constraints_1 (insn, p_sets, noutputs);
5680 return TODO_df_finish;
5683 struct rtl_opt_pass pass_match_asm_constraints =
5687 "asmcons", /* name */
5689 rest_of_match_asm_constraints, /* execute */
5692 0, /* static_pass_number */
5693 TV_NONE, /* tv_id */
5694 0, /* properties_required */
5695 0, /* properties_provided */
5696 0, /* properties_destroyed */
5697 0, /* todo_flags_start */
5698 TODO_dump_func /* todo_flags_finish */
5703 #include "gt-function.h"