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
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 arrays record the INSN_UIDs of the prologue and epilogue insns. */
128 static VEC(int,heap) *prologue;
129 static VEC(int,heap) *epilogue;
131 /* Array of INSN_UIDs to hold the INSN_UIDs for each sibcall epilogue
133 static VEC(int,heap) *sibcall_epilogue;
135 /* In order to evaluate some expressions, such as function calls returning
136 structures in memory, we need to temporarily allocate stack locations.
137 We record each allocated temporary in the following structure.
139 Associated with each temporary slot is a nesting level. When we pop up
140 one level, all temporaries associated with the previous level are freed.
141 Normally, all temporaries are freed after the execution of the statement
142 in which they were created. However, if we are inside a ({...}) grouping,
143 the result may be in a temporary and hence must be preserved. If the
144 result could be in a temporary, we preserve it if we can determine which
145 one it is in. If we cannot determine which temporary may contain the
146 result, all temporaries are preserved. A temporary is preserved by
147 pretending it was allocated at the previous nesting level.
149 Automatic variables are also assigned temporary slots, at the nesting
150 level where they are defined. They are marked a "kept" so that
151 free_temp_slots will not free them. */
153 struct temp_slot GTY(())
155 /* Points to next temporary slot. */
156 struct temp_slot *next;
157 /* Points to previous temporary slot. */
158 struct temp_slot *prev;
160 /* The rtx to used to reference the slot. */
162 /* The rtx used to represent the address if not the address of the
163 slot above. May be an EXPR_LIST if multiple addresses exist. */
165 /* The alignment (in bits) of the slot. */
167 /* The size, in units, of the slot. */
169 /* The type of the object in the slot, or zero if it doesn't correspond
170 to a type. We use this to determine whether a slot can be reused.
171 It can be reused if objects of the type of the new slot will always
172 conflict with objects of the type of the old slot. */
174 /* Nonzero if this temporary is currently in use. */
176 /* Nonzero if this temporary has its address taken. */
178 /* Nesting level at which this slot is being used. */
180 /* Nonzero if this should survive a call to free_temp_slots. */
182 /* The offset of the slot from the frame_pointer, including extra space
183 for alignment. This info is for combine_temp_slots. */
184 HOST_WIDE_INT base_offset;
185 /* The size of the slot, including extra space for alignment. This
186 info is for combine_temp_slots. */
187 HOST_WIDE_INT full_size;
190 /* Forward declarations. */
192 static struct temp_slot *find_temp_slot_from_address (rtx);
193 static void pad_to_arg_alignment (struct args_size *, int, struct args_size *);
194 static void pad_below (struct args_size *, enum machine_mode, tree);
195 static void reorder_blocks_1 (rtx, tree, VEC(tree,heap) **);
196 static int all_blocks (tree, tree *);
197 static tree *get_block_vector (tree, int *);
198 extern tree debug_find_var_in_block_tree (tree, tree);
199 /* We always define `record_insns' even if it's not used so that we
200 can always export `prologue_epilogue_contains'. */
201 static void record_insns (rtx, VEC(int,heap) **) ATTRIBUTE_UNUSED;
202 static int contains (const_rtx, VEC(int,heap) **);
204 static void emit_return_into_block (basic_block);
206 static void prepare_function_start (void);
207 static void do_clobber_return_reg (rtx, void *);
208 static void do_use_return_reg (rtx, void *);
209 static void set_insn_locators (rtx, int) ATTRIBUTE_UNUSED;
211 /* Pointer to chain of `struct function' for containing functions. */
212 struct function *outer_function_chain;
214 /* Given a function decl for a containing function,
215 return the `struct function' for it. */
218 find_function_data (tree decl)
222 for (p = outer_function_chain; p; p = p->outer)
229 /* Save the current context for compilation of a nested function.
230 This is called from language-specific code. */
233 push_function_context (void)
236 allocate_struct_function (NULL, false);
238 cfun->outer = outer_function_chain;
239 outer_function_chain = cfun;
243 /* Restore the last saved context, at the end of a nested function.
244 This function is called from language-specific code. */
247 pop_function_context (void)
249 struct function *p = outer_function_chain;
252 outer_function_chain = p->outer;
253 current_function_decl = p->decl;
255 /* Reset variables that have known state during rtx generation. */
256 virtuals_instantiated = 0;
257 generating_concat_p = 1;
260 /* Clear out all parts of the state in F that can safely be discarded
261 after the function has been parsed, but not compiled, to let
262 garbage collection reclaim the memory. */
265 free_after_parsing (struct function *f)
270 /* Clear out all parts of the state in F that can safely be discarded
271 after the function has been compiled, to let garbage collection
272 reclaim the memory. */
275 free_after_compilation (struct function *f)
277 VEC_free (int, heap, prologue);
278 VEC_free (int, heap, epilogue);
279 VEC_free (int, heap, sibcall_epilogue);
280 if (crtl->emit.regno_pointer_align)
281 free (crtl->emit.regno_pointer_align);
283 memset (crtl, 0, sizeof (struct rtl_data));
288 regno_reg_rtx = NULL;
291 /* Return size needed for stack frame based on slots so far allocated.
292 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
293 the caller may have to do that. */
296 get_frame_size (void)
298 if (FRAME_GROWS_DOWNWARD)
299 return -frame_offset;
304 /* Issue an error message and return TRUE if frame OFFSET overflows in
305 the signed target pointer arithmetics for function FUNC. Otherwise
309 frame_offset_overflow (HOST_WIDE_INT offset, tree func)
311 unsigned HOST_WIDE_INT size = FRAME_GROWS_DOWNWARD ? -offset : offset;
313 if (size > ((unsigned HOST_WIDE_INT) 1 << (GET_MODE_BITSIZE (Pmode) - 1))
314 /* Leave room for the fixed part of the frame. */
315 - 64 * UNITS_PER_WORD)
317 error ("%Jtotal size of local objects too large", func);
324 /* Return stack slot alignment in bits for TYPE and MODE. */
327 get_stack_local_alignment (tree type, enum machine_mode mode)
329 unsigned int alignment;
332 alignment = BIGGEST_ALIGNMENT;
334 alignment = GET_MODE_ALIGNMENT (mode);
336 /* Allow the frond-end to (possibly) increase the alignment of this
339 type = lang_hooks.types.type_for_mode (mode, 0);
341 return STACK_SLOT_ALIGNMENT (type, mode, alignment);
344 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
345 with machine mode MODE.
347 ALIGN controls the amount of alignment for the address of the slot:
348 0 means according to MODE,
349 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
350 -2 means use BITS_PER_UNIT,
351 positive specifies alignment boundary in bits.
353 If REDUCE_ALIGNMENT_OK is true, it is OK to reduce alignment.
355 We do not round to stack_boundary here. */
358 assign_stack_local_1 (enum machine_mode mode, HOST_WIDE_INT size,
360 bool reduce_alignment_ok ATTRIBUTE_UNUSED)
363 int bigend_correction = 0;
364 unsigned int alignment, alignment_in_bits;
365 int frame_off, frame_alignment, frame_phase;
369 alignment = get_stack_local_alignment (NULL, mode);
370 alignment /= BITS_PER_UNIT;
372 else if (align == -1)
374 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
375 size = CEIL_ROUND (size, alignment);
377 else if (align == -2)
378 alignment = 1; /* BITS_PER_UNIT / BITS_PER_UNIT */
380 alignment = align / BITS_PER_UNIT;
382 alignment_in_bits = alignment * BITS_PER_UNIT;
384 if (FRAME_GROWS_DOWNWARD)
385 frame_offset -= size;
387 /* Ignore alignment if it exceeds MAX_SUPPORTED_STACK_ALIGNMENT. */
388 if (alignment_in_bits > MAX_SUPPORTED_STACK_ALIGNMENT)
390 alignment_in_bits = MAX_SUPPORTED_STACK_ALIGNMENT;
391 alignment = alignment_in_bits / BITS_PER_UNIT;
394 if (SUPPORTS_STACK_ALIGNMENT)
396 if (crtl->stack_alignment_estimated < alignment_in_bits)
398 if (!crtl->stack_realign_processed)
399 crtl->stack_alignment_estimated = alignment_in_bits;
402 /* If stack is realigned and stack alignment value
403 hasn't been finalized, it is OK not to increase
404 stack_alignment_estimated. The bigger alignment
405 requirement is recorded in stack_alignment_needed
407 gcc_assert (!crtl->stack_realign_finalized);
408 if (!crtl->stack_realign_needed)
410 /* It is OK to reduce the alignment as long as the
411 requested size is 0 or the estimated stack
412 alignment >= mode alignment. */
413 gcc_assert (reduce_alignment_ok
415 || (crtl->stack_alignment_estimated
416 >= GET_MODE_ALIGNMENT (mode)));
417 alignment_in_bits = crtl->stack_alignment_estimated;
418 alignment = alignment_in_bits / BITS_PER_UNIT;
424 if (crtl->stack_alignment_needed < alignment_in_bits)
425 crtl->stack_alignment_needed = alignment_in_bits;
426 if (crtl->max_used_stack_slot_alignment < crtl->stack_alignment_needed)
427 crtl->max_used_stack_slot_alignment = crtl->stack_alignment_needed;
429 /* Calculate how many bytes the start of local variables is off from
431 frame_alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
432 frame_off = STARTING_FRAME_OFFSET % frame_alignment;
433 frame_phase = frame_off ? frame_alignment - frame_off : 0;
435 /* Round the frame offset to the specified alignment. The default is
436 to always honor requests to align the stack but a port may choose to
437 do its own stack alignment by defining STACK_ALIGNMENT_NEEDED. */
438 if (STACK_ALIGNMENT_NEEDED
442 /* We must be careful here, since FRAME_OFFSET might be negative and
443 division with a negative dividend isn't as well defined as we might
444 like. So we instead assume that ALIGNMENT is a power of two and
445 use logical operations which are unambiguous. */
446 if (FRAME_GROWS_DOWNWARD)
448 = (FLOOR_ROUND (frame_offset - frame_phase,
449 (unsigned HOST_WIDE_INT) alignment)
453 = (CEIL_ROUND (frame_offset - frame_phase,
454 (unsigned HOST_WIDE_INT) alignment)
458 /* On a big-endian machine, if we are allocating more space than we will use,
459 use the least significant bytes of those that are allocated. */
460 if (BYTES_BIG_ENDIAN && mode != BLKmode && GET_MODE_SIZE (mode) < size)
461 bigend_correction = size - GET_MODE_SIZE (mode);
463 /* If we have already instantiated virtual registers, return the actual
464 address relative to the frame pointer. */
465 if (virtuals_instantiated)
466 addr = plus_constant (frame_pointer_rtx,
468 (frame_offset + bigend_correction
469 + STARTING_FRAME_OFFSET, Pmode));
471 addr = plus_constant (virtual_stack_vars_rtx,
473 (frame_offset + bigend_correction,
476 if (!FRAME_GROWS_DOWNWARD)
477 frame_offset += size;
479 x = gen_rtx_MEM (mode, addr);
480 set_mem_align (x, alignment_in_bits);
481 MEM_NOTRAP_P (x) = 1;
484 = gen_rtx_EXPR_LIST (VOIDmode, x, stack_slot_list);
486 if (frame_offset_overflow (frame_offset, current_function_decl))
492 /* Wrap up assign_stack_local_1 with last parameter as false. */
495 assign_stack_local (enum machine_mode mode, HOST_WIDE_INT size, int align)
497 return assign_stack_local_1 (mode, size, align, false);
500 /* Removes temporary slot TEMP from LIST. */
503 cut_slot_from_list (struct temp_slot *temp, struct temp_slot **list)
506 temp->next->prev = temp->prev;
508 temp->prev->next = temp->next;
512 temp->prev = temp->next = NULL;
515 /* Inserts temporary slot TEMP to LIST. */
518 insert_slot_to_list (struct temp_slot *temp, struct temp_slot **list)
522 (*list)->prev = temp;
527 /* Returns the list of used temp slots at LEVEL. */
529 static struct temp_slot **
530 temp_slots_at_level (int level)
532 if (level >= (int) VEC_length (temp_slot_p, used_temp_slots))
533 VEC_safe_grow_cleared (temp_slot_p, gc, used_temp_slots, level + 1);
535 return &(VEC_address (temp_slot_p, used_temp_slots)[level]);
538 /* Returns the maximal temporary slot level. */
541 max_slot_level (void)
543 if (!used_temp_slots)
546 return VEC_length (temp_slot_p, used_temp_slots) - 1;
549 /* Moves temporary slot TEMP to LEVEL. */
552 move_slot_to_level (struct temp_slot *temp, int level)
554 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
555 insert_slot_to_list (temp, temp_slots_at_level (level));
559 /* Make temporary slot TEMP available. */
562 make_slot_available (struct temp_slot *temp)
564 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
565 insert_slot_to_list (temp, &avail_temp_slots);
570 /* Allocate a temporary stack slot and record it for possible later
573 MODE is the machine mode to be given to the returned rtx.
575 SIZE is the size in units of the space required. We do no rounding here
576 since assign_stack_local will do any required rounding.
578 KEEP is 1 if this slot is to be retained after a call to
579 free_temp_slots. Automatic variables for a block are allocated
580 with this flag. KEEP values of 2 or 3 were needed respectively
581 for variables whose lifetime is controlled by CLEANUP_POINT_EXPRs
582 or for SAVE_EXPRs, but they are now unused.
584 TYPE is the type that will be used for the stack slot. */
587 assign_stack_temp_for_type (enum machine_mode mode, HOST_WIDE_INT size,
591 struct temp_slot *p, *best_p = 0, *selected = NULL, **pp;
594 /* If SIZE is -1 it means that somebody tried to allocate a temporary
595 of a variable size. */
596 gcc_assert (size != -1);
598 /* These are now unused. */
599 gcc_assert (keep <= 1);
601 align = get_stack_local_alignment (type, mode);
603 /* Try to find an available, already-allocated temporary of the proper
604 mode which meets the size and alignment requirements. Choose the
605 smallest one with the closest alignment.
607 If assign_stack_temp is called outside of the tree->rtl expansion,
608 we cannot reuse the stack slots (that may still refer to
609 VIRTUAL_STACK_VARS_REGNUM). */
610 if (!virtuals_instantiated)
612 for (p = avail_temp_slots; p; p = p->next)
614 if (p->align >= align && p->size >= size
615 && GET_MODE (p->slot) == mode
616 && objects_must_conflict_p (p->type, type)
617 && (best_p == 0 || best_p->size > p->size
618 || (best_p->size == p->size && best_p->align > p->align)))
620 if (p->align == align && p->size == size)
623 cut_slot_from_list (selected, &avail_temp_slots);
632 /* Make our best, if any, the one to use. */
636 cut_slot_from_list (selected, &avail_temp_slots);
638 /* If there are enough aligned bytes left over, make them into a new
639 temp_slot so that the extra bytes don't get wasted. Do this only
640 for BLKmode slots, so that we can be sure of the alignment. */
641 if (GET_MODE (best_p->slot) == BLKmode)
643 int alignment = best_p->align / BITS_PER_UNIT;
644 HOST_WIDE_INT rounded_size = CEIL_ROUND (size, alignment);
646 if (best_p->size - rounded_size >= alignment)
648 p = GGC_NEW (struct temp_slot);
649 p->in_use = p->addr_taken = 0;
650 p->size = best_p->size - rounded_size;
651 p->base_offset = best_p->base_offset + rounded_size;
652 p->full_size = best_p->full_size - rounded_size;
653 p->slot = adjust_address_nv (best_p->slot, BLKmode, rounded_size);
654 p->align = best_p->align;
656 p->type = best_p->type;
657 insert_slot_to_list (p, &avail_temp_slots);
659 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, p->slot,
662 best_p->size = rounded_size;
663 best_p->full_size = rounded_size;
668 /* If we still didn't find one, make a new temporary. */
671 HOST_WIDE_INT frame_offset_old = frame_offset;
673 p = GGC_NEW (struct temp_slot);
675 /* We are passing an explicit alignment request to assign_stack_local.
676 One side effect of that is assign_stack_local will not round SIZE
677 to ensure the frame offset remains suitably aligned.
679 So for requests which depended on the rounding of SIZE, we go ahead
680 and round it now. We also make sure ALIGNMENT is at least
681 BIGGEST_ALIGNMENT. */
682 gcc_assert (mode != BLKmode || align == BIGGEST_ALIGNMENT);
683 p->slot = assign_stack_local (mode,
685 ? CEIL_ROUND (size, (int) align / BITS_PER_UNIT)
691 /* The following slot size computation is necessary because we don't
692 know the actual size of the temporary slot until assign_stack_local
693 has performed all the frame alignment and size rounding for the
694 requested temporary. Note that extra space added for alignment
695 can be either above or below this stack slot depending on which
696 way the frame grows. We include the extra space if and only if it
697 is above this slot. */
698 if (FRAME_GROWS_DOWNWARD)
699 p->size = frame_offset_old - frame_offset;
703 /* Now define the fields used by combine_temp_slots. */
704 if (FRAME_GROWS_DOWNWARD)
706 p->base_offset = frame_offset;
707 p->full_size = frame_offset_old - frame_offset;
711 p->base_offset = frame_offset_old;
712 p->full_size = frame_offset - frame_offset_old;
723 p->level = temp_slot_level;
726 pp = temp_slots_at_level (p->level);
727 insert_slot_to_list (p, pp);
729 /* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
730 slot = gen_rtx_MEM (mode, XEXP (p->slot, 0));
731 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, slot, stack_slot_list);
733 /* If we know the alias set for the memory that will be used, use
734 it. If there's no TYPE, then we don't know anything about the
735 alias set for the memory. */
736 set_mem_alias_set (slot, type ? get_alias_set (type) : 0);
737 set_mem_align (slot, align);
739 /* If a type is specified, set the relevant flags. */
742 MEM_VOLATILE_P (slot) = TYPE_VOLATILE (type);
743 MEM_SET_IN_STRUCT_P (slot, (AGGREGATE_TYPE_P (type)
744 || TREE_CODE (type) == COMPLEX_TYPE));
746 MEM_NOTRAP_P (slot) = 1;
751 /* Allocate a temporary stack slot and record it for possible later
752 reuse. First three arguments are same as in preceding function. */
755 assign_stack_temp (enum machine_mode mode, HOST_WIDE_INT size, int keep)
757 return assign_stack_temp_for_type (mode, size, keep, NULL_TREE);
760 /* Assign a temporary.
761 If TYPE_OR_DECL is a decl, then we are doing it on behalf of the decl
762 and so that should be used in error messages. In either case, we
763 allocate of the given type.
764 KEEP is as for assign_stack_temp.
765 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
766 it is 0 if a register is OK.
767 DONT_PROMOTE is 1 if we should not promote values in register
771 assign_temp (tree type_or_decl, int keep, int memory_required,
772 int dont_promote ATTRIBUTE_UNUSED)
775 enum machine_mode mode;
780 if (DECL_P (type_or_decl))
781 decl = type_or_decl, type = TREE_TYPE (decl);
783 decl = NULL, type = type_or_decl;
785 mode = TYPE_MODE (type);
787 unsignedp = TYPE_UNSIGNED (type);
790 if (mode == BLKmode || memory_required)
792 HOST_WIDE_INT size = int_size_in_bytes (type);
795 /* Zero sized arrays are GNU C extension. Set size to 1 to avoid
796 problems with allocating the stack space. */
800 /* Unfortunately, we don't yet know how to allocate variable-sized
801 temporaries. However, sometimes we can find a fixed upper limit on
802 the size, so try that instead. */
804 size = max_int_size_in_bytes (type);
806 /* The size of the temporary may be too large to fit into an integer. */
807 /* ??? Not sure this should happen except for user silliness, so limit
808 this to things that aren't compiler-generated temporaries. The
809 rest of the time we'll die in assign_stack_temp_for_type. */
810 if (decl && size == -1
811 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST)
813 error ("size of variable %q+D is too large", decl);
817 tmp = assign_stack_temp_for_type (mode, size, keep, type);
823 mode = promote_mode (type, mode, &unsignedp, 0);
826 return gen_reg_rtx (mode);
829 /* Combine temporary stack slots which are adjacent on the stack.
831 This allows for better use of already allocated stack space. This is only
832 done for BLKmode slots because we can be sure that we won't have alignment
833 problems in this case. */
836 combine_temp_slots (void)
838 struct temp_slot *p, *q, *next, *next_q;
841 /* We can't combine slots, because the information about which slot
842 is in which alias set will be lost. */
843 if (flag_strict_aliasing)
846 /* If there are a lot of temp slots, don't do anything unless
847 high levels of optimization. */
848 if (! flag_expensive_optimizations)
849 for (p = avail_temp_slots, num_slots = 0; p; p = p->next, num_slots++)
850 if (num_slots > 100 || (num_slots > 10 && optimize == 0))
853 for (p = avail_temp_slots; p; p = next)
859 if (GET_MODE (p->slot) != BLKmode)
862 for (q = p->next; q; q = next_q)
868 if (GET_MODE (q->slot) != BLKmode)
871 if (p->base_offset + p->full_size == q->base_offset)
873 /* Q comes after P; combine Q into P. */
875 p->full_size += q->full_size;
878 else if (q->base_offset + q->full_size == p->base_offset)
880 /* P comes after Q; combine P into Q. */
882 q->full_size += p->full_size;
887 cut_slot_from_list (q, &avail_temp_slots);
890 /* Either delete P or advance past it. */
892 cut_slot_from_list (p, &avail_temp_slots);
896 /* Find the temp slot corresponding to the object at address X. */
898 static struct temp_slot *
899 find_temp_slot_from_address (rtx x)
905 for (i = max_slot_level (); i >= 0; i--)
906 for (p = *temp_slots_at_level (i); p; p = p->next)
908 if (XEXP (p->slot, 0) == x
910 || (GET_CODE (x) == PLUS
911 && XEXP (x, 0) == virtual_stack_vars_rtx
912 && GET_CODE (XEXP (x, 1)) == CONST_INT
913 && INTVAL (XEXP (x, 1)) >= p->base_offset
914 && INTVAL (XEXP (x, 1)) < p->base_offset + p->full_size))
917 else if (p->address != 0 && GET_CODE (p->address) == EXPR_LIST)
918 for (next = p->address; next; next = XEXP (next, 1))
919 if (XEXP (next, 0) == x)
923 /* If we have a sum involving a register, see if it points to a temp
925 if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 0))
926 && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
928 else if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 1))
929 && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
935 /* Indicate that NEW_RTX is an alternate way of referring to the temp
936 slot that previously was known by OLD_RTX. */
939 update_temp_slot_address (rtx old_rtx, rtx new_rtx)
943 if (rtx_equal_p (old_rtx, new_rtx))
946 p = find_temp_slot_from_address (old_rtx);
948 /* If we didn't find one, see if both OLD_RTX is a PLUS. If so, and
949 NEW_RTX is a register, see if one operand of the PLUS is a
950 temporary location. If so, NEW_RTX points into it. Otherwise,
951 if both OLD_RTX and NEW_RTX are a PLUS and if there is a register
952 in common between them. If so, try a recursive call on those
956 if (GET_CODE (old_rtx) != PLUS)
961 update_temp_slot_address (XEXP (old_rtx, 0), new_rtx);
962 update_temp_slot_address (XEXP (old_rtx, 1), new_rtx);
965 else if (GET_CODE (new_rtx) != PLUS)
968 if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 0)))
969 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 1));
970 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 0)))
971 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 1));
972 else if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 1)))
973 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 0));
974 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 1)))
975 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 0));
980 /* Otherwise add an alias for the temp's address. */
981 else if (p->address == 0)
982 p->address = new_rtx;
985 if (GET_CODE (p->address) != EXPR_LIST)
986 p->address = gen_rtx_EXPR_LIST (VOIDmode, p->address, NULL_RTX);
988 p->address = gen_rtx_EXPR_LIST (VOIDmode, new_rtx, p->address);
992 /* If X could be a reference to a temporary slot, mark the fact that its
993 address was taken. */
996 mark_temp_addr_taken (rtx x)
1003 /* If X is not in memory or is at a constant address, it cannot be in
1004 a temporary slot. */
1005 if (!MEM_P (x) || CONSTANT_P (XEXP (x, 0)))
1008 p = find_temp_slot_from_address (XEXP (x, 0));
1013 /* If X could be a reference to a temporary slot, mark that slot as
1014 belonging to the to one level higher than the current level. If X
1015 matched one of our slots, just mark that one. Otherwise, we can't
1016 easily predict which it is, so upgrade all of them. Kept slots
1017 need not be touched.
1019 This is called when an ({...}) construct occurs and a statement
1020 returns a value in memory. */
1023 preserve_temp_slots (rtx x)
1025 struct temp_slot *p = 0, *next;
1027 /* If there is no result, we still might have some objects whose address
1028 were taken, so we need to make sure they stay around. */
1031 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1036 move_slot_to_level (p, temp_slot_level - 1);
1042 /* If X is a register that is being used as a pointer, see if we have
1043 a temporary slot we know it points to. To be consistent with
1044 the code below, we really should preserve all non-kept slots
1045 if we can't find a match, but that seems to be much too costly. */
1046 if (REG_P (x) && REG_POINTER (x))
1047 p = find_temp_slot_from_address (x);
1049 /* If X is not in memory or is at a constant address, it cannot be in
1050 a temporary slot, but it can contain something whose address was
1052 if (p == 0 && (!MEM_P (x) || CONSTANT_P (XEXP (x, 0))))
1054 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1059 move_slot_to_level (p, temp_slot_level - 1);
1065 /* First see if we can find a match. */
1067 p = find_temp_slot_from_address (XEXP (x, 0));
1071 /* Move everything at our level whose address was taken to our new
1072 level in case we used its address. */
1073 struct temp_slot *q;
1075 if (p->level == temp_slot_level)
1077 for (q = *temp_slots_at_level (temp_slot_level); q; q = next)
1081 if (p != q && q->addr_taken)
1082 move_slot_to_level (q, temp_slot_level - 1);
1085 move_slot_to_level (p, temp_slot_level - 1);
1091 /* Otherwise, preserve all non-kept slots at this level. */
1092 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1097 move_slot_to_level (p, temp_slot_level - 1);
1101 /* Free all temporaries used so far. This is normally called at the
1102 end of generating code for a statement. */
1105 free_temp_slots (void)
1107 struct temp_slot *p, *next;
1109 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1114 make_slot_available (p);
1117 combine_temp_slots ();
1120 /* Push deeper into the nesting level for stack temporaries. */
1123 push_temp_slots (void)
1128 /* Pop a temporary nesting level. All slots in use in the current level
1132 pop_temp_slots (void)
1134 struct temp_slot *p, *next;
1136 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1139 make_slot_available (p);
1142 combine_temp_slots ();
1147 /* Initialize temporary slots. */
1150 init_temp_slots (void)
1152 /* We have not allocated any temporaries yet. */
1153 avail_temp_slots = 0;
1154 used_temp_slots = 0;
1155 temp_slot_level = 0;
1158 /* These routines are responsible for converting virtual register references
1159 to the actual hard register references once RTL generation is complete.
1161 The following four variables are used for communication between the
1162 routines. They contain the offsets of the virtual registers from their
1163 respective hard registers. */
1165 static int in_arg_offset;
1166 static int var_offset;
1167 static int dynamic_offset;
1168 static int out_arg_offset;
1169 static int cfa_offset;
1171 /* In most machines, the stack pointer register is equivalent to the bottom
1174 #ifndef STACK_POINTER_OFFSET
1175 #define STACK_POINTER_OFFSET 0
1178 /* If not defined, pick an appropriate default for the offset of dynamically
1179 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
1180 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
1182 #ifndef STACK_DYNAMIC_OFFSET
1184 /* The bottom of the stack points to the actual arguments. If
1185 REG_PARM_STACK_SPACE is defined, this includes the space for the register
1186 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
1187 stack space for register parameters is not pushed by the caller, but
1188 rather part of the fixed stack areas and hence not included in
1189 `crtl->outgoing_args_size'. Nevertheless, we must allow
1190 for it when allocating stack dynamic objects. */
1192 #if defined(REG_PARM_STACK_SPACE)
1193 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1194 ((ACCUMULATE_OUTGOING_ARGS \
1195 ? (crtl->outgoing_args_size \
1196 + (OUTGOING_REG_PARM_STACK_SPACE ((!(FNDECL) ? NULL_TREE : TREE_TYPE (FNDECL))) ? 0 \
1197 : REG_PARM_STACK_SPACE (FNDECL))) \
1198 : 0) + (STACK_POINTER_OFFSET))
1200 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1201 ((ACCUMULATE_OUTGOING_ARGS ? crtl->outgoing_args_size : 0) \
1202 + (STACK_POINTER_OFFSET))
1207 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
1208 is a virtual register, return the equivalent hard register and set the
1209 offset indirectly through the pointer. Otherwise, return 0. */
1212 instantiate_new_reg (rtx x, HOST_WIDE_INT *poffset)
1215 HOST_WIDE_INT offset;
1217 if (x == virtual_incoming_args_rtx)
1219 if (stack_realign_drap)
1221 /* Replace virtual_incoming_args_rtx with internal arg
1222 pointer if DRAP is used to realign stack. */
1223 new_rtx = crtl->args.internal_arg_pointer;
1227 new_rtx = arg_pointer_rtx, offset = in_arg_offset;
1229 else if (x == virtual_stack_vars_rtx)
1230 new_rtx = frame_pointer_rtx, offset = var_offset;
1231 else if (x == virtual_stack_dynamic_rtx)
1232 new_rtx = stack_pointer_rtx, offset = dynamic_offset;
1233 else if (x == virtual_outgoing_args_rtx)
1234 new_rtx = stack_pointer_rtx, offset = out_arg_offset;
1235 else if (x == virtual_cfa_rtx)
1237 #ifdef FRAME_POINTER_CFA_OFFSET
1238 new_rtx = frame_pointer_rtx;
1240 new_rtx = arg_pointer_rtx;
1242 offset = cfa_offset;
1251 /* A subroutine of instantiate_virtual_regs, called via for_each_rtx.
1252 Instantiate any virtual registers present inside of *LOC. The expression
1253 is simplified, as much as possible, but is not to be considered "valid"
1254 in any sense implied by the target. If any change is made, set CHANGED
1258 instantiate_virtual_regs_in_rtx (rtx *loc, void *data)
1260 HOST_WIDE_INT offset;
1261 bool *changed = (bool *) data;
1268 switch (GET_CODE (x))
1271 new_rtx = instantiate_new_reg (x, &offset);
1274 *loc = plus_constant (new_rtx, offset);
1281 new_rtx = instantiate_new_reg (XEXP (x, 0), &offset);
1284 new_rtx = plus_constant (new_rtx, offset);
1285 *loc = simplify_gen_binary (PLUS, GET_MODE (x), new_rtx, XEXP (x, 1));
1291 /* FIXME -- from old code */
1292 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
1293 we can commute the PLUS and SUBREG because pointers into the
1294 frame are well-behaved. */
1304 /* A subroutine of instantiate_virtual_regs_in_insn. Return true if X
1305 matches the predicate for insn CODE operand OPERAND. */
1308 safe_insn_predicate (int code, int operand, rtx x)
1310 const struct insn_operand_data *op_data;
1315 op_data = &insn_data[code].operand[operand];
1316 if (op_data->predicate == NULL)
1319 return op_data->predicate (x, op_data->mode);
1322 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1323 registers present inside of insn. The result will be a valid insn. */
1326 instantiate_virtual_regs_in_insn (rtx insn)
1328 HOST_WIDE_INT offset;
1330 bool any_change = false;
1331 rtx set, new_rtx, x, seq;
1333 /* There are some special cases to be handled first. */
1334 set = single_set (insn);
1337 /* We're allowed to assign to a virtual register. This is interpreted
1338 to mean that the underlying register gets assigned the inverse
1339 transformation. This is used, for example, in the handling of
1341 new_rtx = instantiate_new_reg (SET_DEST (set), &offset);
1346 for_each_rtx (&SET_SRC (set), instantiate_virtual_regs_in_rtx, NULL);
1347 x = simplify_gen_binary (PLUS, GET_MODE (new_rtx), SET_SRC (set),
1349 x = force_operand (x, new_rtx);
1351 emit_move_insn (new_rtx, x);
1356 emit_insn_before (seq, insn);
1361 /* Handle a straight copy from a virtual register by generating a
1362 new add insn. The difference between this and falling through
1363 to the generic case is avoiding a new pseudo and eliminating a
1364 move insn in the initial rtl stream. */
1365 new_rtx = instantiate_new_reg (SET_SRC (set), &offset);
1366 if (new_rtx && offset != 0
1367 && REG_P (SET_DEST (set))
1368 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1372 x = expand_simple_binop (GET_MODE (SET_DEST (set)), PLUS,
1373 new_rtx, GEN_INT (offset), SET_DEST (set),
1374 1, OPTAB_LIB_WIDEN);
1375 if (x != SET_DEST (set))
1376 emit_move_insn (SET_DEST (set), x);
1381 emit_insn_before (seq, insn);
1386 extract_insn (insn);
1387 insn_code = INSN_CODE (insn);
1389 /* Handle a plus involving a virtual register by determining if the
1390 operands remain valid if they're modified in place. */
1391 if (GET_CODE (SET_SRC (set)) == PLUS
1392 && recog_data.n_operands >= 3
1393 && recog_data.operand_loc[1] == &XEXP (SET_SRC (set), 0)
1394 && recog_data.operand_loc[2] == &XEXP (SET_SRC (set), 1)
1395 && GET_CODE (recog_data.operand[2]) == CONST_INT
1396 && (new_rtx = instantiate_new_reg (recog_data.operand[1], &offset)))
1398 offset += INTVAL (recog_data.operand[2]);
1400 /* If the sum is zero, then replace with a plain move. */
1402 && REG_P (SET_DEST (set))
1403 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1406 emit_move_insn (SET_DEST (set), new_rtx);
1410 emit_insn_before (seq, insn);
1415 x = gen_int_mode (offset, recog_data.operand_mode[2]);
1417 /* Using validate_change and apply_change_group here leaves
1418 recog_data in an invalid state. Since we know exactly what
1419 we want to check, do those two by hand. */
1420 if (safe_insn_predicate (insn_code, 1, new_rtx)
1421 && safe_insn_predicate (insn_code, 2, x))
1423 *recog_data.operand_loc[1] = recog_data.operand[1] = new_rtx;
1424 *recog_data.operand_loc[2] = recog_data.operand[2] = x;
1427 /* Fall through into the regular operand fixup loop in
1428 order to take care of operands other than 1 and 2. */
1434 extract_insn (insn);
1435 insn_code = INSN_CODE (insn);
1438 /* In the general case, we expect virtual registers to appear only in
1439 operands, and then only as either bare registers or inside memories. */
1440 for (i = 0; i < recog_data.n_operands; ++i)
1442 x = recog_data.operand[i];
1443 switch (GET_CODE (x))
1447 rtx addr = XEXP (x, 0);
1448 bool changed = false;
1450 for_each_rtx (&addr, instantiate_virtual_regs_in_rtx, &changed);
1455 x = replace_equiv_address (x, addr);
1456 /* It may happen that the address with the virtual reg
1457 was valid (e.g. based on the virtual stack reg, which might
1458 be acceptable to the predicates with all offsets), whereas
1459 the address now isn't anymore, for instance when the address
1460 is still offsetted, but the base reg isn't virtual-stack-reg
1461 anymore. Below we would do a force_reg on the whole operand,
1462 but this insn might actually only accept memory. Hence,
1463 before doing that last resort, try to reload the address into
1464 a register, so this operand stays a MEM. */
1465 if (!safe_insn_predicate (insn_code, i, x))
1467 addr = force_reg (GET_MODE (addr), addr);
1468 x = replace_equiv_address (x, addr);
1473 emit_insn_before (seq, insn);
1478 new_rtx = instantiate_new_reg (x, &offset);
1479 if (new_rtx == NULL)
1487 /* Careful, special mode predicates may have stuff in
1488 insn_data[insn_code].operand[i].mode that isn't useful
1489 to us for computing a new value. */
1490 /* ??? Recognize address_operand and/or "p" constraints
1491 to see if (plus new offset) is a valid before we put
1492 this through expand_simple_binop. */
1493 x = expand_simple_binop (GET_MODE (x), PLUS, new_rtx,
1494 GEN_INT (offset), NULL_RTX,
1495 1, OPTAB_LIB_WIDEN);
1498 emit_insn_before (seq, insn);
1503 new_rtx = instantiate_new_reg (SUBREG_REG (x), &offset);
1504 if (new_rtx == NULL)
1509 new_rtx = expand_simple_binop (GET_MODE (new_rtx), PLUS, new_rtx,
1510 GEN_INT (offset), NULL_RTX,
1511 1, OPTAB_LIB_WIDEN);
1514 emit_insn_before (seq, insn);
1516 x = simplify_gen_subreg (recog_data.operand_mode[i], new_rtx,
1517 GET_MODE (new_rtx), SUBREG_BYTE (x));
1525 /* At this point, X contains the new value for the operand.
1526 Validate the new value vs the insn predicate. Note that
1527 asm insns will have insn_code -1 here. */
1528 if (!safe_insn_predicate (insn_code, i, x))
1531 x = force_reg (insn_data[insn_code].operand[i].mode, x);
1535 emit_insn_before (seq, insn);
1538 *recog_data.operand_loc[i] = recog_data.operand[i] = x;
1544 /* Propagate operand changes into the duplicates. */
1545 for (i = 0; i < recog_data.n_dups; ++i)
1546 *recog_data.dup_loc[i]
1547 = copy_rtx (recog_data.operand[(unsigned)recog_data.dup_num[i]]);
1549 /* Force re-recognition of the instruction for validation. */
1550 INSN_CODE (insn) = -1;
1553 if (asm_noperands (PATTERN (insn)) >= 0)
1555 if (!check_asm_operands (PATTERN (insn)))
1557 error_for_asm (insn, "impossible constraint in %<asm%>");
1563 if (recog_memoized (insn) < 0)
1564 fatal_insn_not_found (insn);
1568 /* Subroutine of instantiate_decls. Given RTL representing a decl,
1569 do any instantiation required. */
1572 instantiate_decl_rtl (rtx x)
1579 /* If this is a CONCAT, recurse for the pieces. */
1580 if (GET_CODE (x) == CONCAT)
1582 instantiate_decl_rtl (XEXP (x, 0));
1583 instantiate_decl_rtl (XEXP (x, 1));
1587 /* If this is not a MEM, no need to do anything. Similarly if the
1588 address is a constant or a register that is not a virtual register. */
1593 if (CONSTANT_P (addr)
1595 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
1596 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
1599 for_each_rtx (&XEXP (x, 0), instantiate_virtual_regs_in_rtx, NULL);
1602 /* Helper for instantiate_decls called via walk_tree: Process all decls
1603 in the given DECL_VALUE_EXPR. */
1606 instantiate_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1612 if (DECL_P (t) && DECL_RTL_SET_P (t))
1613 instantiate_decl_rtl (DECL_RTL (t));
1618 /* Subroutine of instantiate_decls: Process all decls in the given
1619 BLOCK node and all its subblocks. */
1622 instantiate_decls_1 (tree let)
1626 for (t = BLOCK_VARS (let); t; t = TREE_CHAIN (t))
1628 if (DECL_RTL_SET_P (t))
1629 instantiate_decl_rtl (DECL_RTL (t));
1630 if (TREE_CODE (t) == VAR_DECL && DECL_HAS_VALUE_EXPR_P (t))
1632 tree v = DECL_VALUE_EXPR (t);
1633 walk_tree (&v, instantiate_expr, NULL, NULL);
1637 /* Process all subblocks. */
1638 for (t = BLOCK_SUBBLOCKS (let); t; t = BLOCK_CHAIN (t))
1639 instantiate_decls_1 (t);
1642 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1643 all virtual registers in their DECL_RTL's. */
1646 instantiate_decls (tree fndecl)
1650 /* Process all parameters of the function. */
1651 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = TREE_CHAIN (decl))
1653 instantiate_decl_rtl (DECL_RTL (decl));
1654 instantiate_decl_rtl (DECL_INCOMING_RTL (decl));
1655 if (DECL_HAS_VALUE_EXPR_P (decl))
1657 tree v = DECL_VALUE_EXPR (decl);
1658 walk_tree (&v, instantiate_expr, NULL, NULL);
1662 /* Now process all variables defined in the function or its subblocks. */
1663 instantiate_decls_1 (DECL_INITIAL (fndecl));
1666 /* Pass through the INSNS of function FNDECL and convert virtual register
1667 references to hard register references. */
1670 instantiate_virtual_regs (void)
1674 /* Compute the offsets to use for this function. */
1675 in_arg_offset = FIRST_PARM_OFFSET (current_function_decl);
1676 var_offset = STARTING_FRAME_OFFSET;
1677 dynamic_offset = STACK_DYNAMIC_OFFSET (current_function_decl);
1678 out_arg_offset = STACK_POINTER_OFFSET;
1679 #ifdef FRAME_POINTER_CFA_OFFSET
1680 cfa_offset = FRAME_POINTER_CFA_OFFSET (current_function_decl);
1682 cfa_offset = ARG_POINTER_CFA_OFFSET (current_function_decl);
1685 /* Initialize recognition, indicating that volatile is OK. */
1688 /* Scan through all the insns, instantiating every virtual register still
1690 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
1693 /* These patterns in the instruction stream can never be recognized.
1694 Fortunately, they shouldn't contain virtual registers either. */
1695 if (GET_CODE (PATTERN (insn)) == USE
1696 || GET_CODE (PATTERN (insn)) == CLOBBER
1697 || GET_CODE (PATTERN (insn)) == ADDR_VEC
1698 || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC
1699 || GET_CODE (PATTERN (insn)) == ASM_INPUT)
1702 instantiate_virtual_regs_in_insn (insn);
1704 if (INSN_DELETED_P (insn))
1707 for_each_rtx (®_NOTES (insn), instantiate_virtual_regs_in_rtx, NULL);
1709 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
1710 if (GET_CODE (insn) == CALL_INSN)
1711 for_each_rtx (&CALL_INSN_FUNCTION_USAGE (insn),
1712 instantiate_virtual_regs_in_rtx, NULL);
1715 /* Instantiate the virtual registers in the DECLs for debugging purposes. */
1716 instantiate_decls (current_function_decl);
1718 targetm.instantiate_decls ();
1720 /* Indicate that, from now on, assign_stack_local should use
1721 frame_pointer_rtx. */
1722 virtuals_instantiated = 1;
1726 struct rtl_opt_pass pass_instantiate_virtual_regs =
1732 instantiate_virtual_regs, /* execute */
1735 0, /* static_pass_number */
1737 0, /* properties_required */
1738 0, /* properties_provided */
1739 0, /* properties_destroyed */
1740 0, /* todo_flags_start */
1741 TODO_dump_func /* todo_flags_finish */
1746 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
1747 This means a type for which function calls must pass an address to the
1748 function or get an address back from the function.
1749 EXP may be a type node or an expression (whose type is tested). */
1752 aggregate_value_p (const_tree exp, const_tree fntype)
1754 int i, regno, nregs;
1757 const_tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
1759 /* DECL node associated with FNTYPE when relevant, which we might need to
1760 check for by-invisible-reference returns, typically for CALL_EXPR input
1762 const_tree fndecl = NULL_TREE;
1765 switch (TREE_CODE (fntype))
1768 fndecl = get_callee_fndecl (fntype);
1769 fntype = fndecl ? TREE_TYPE (fndecl) : 0;
1773 fntype = TREE_TYPE (fndecl);
1778 case IDENTIFIER_NODE:
1782 /* We don't expect other rtl types here. */
1786 if (TREE_CODE (type) == VOID_TYPE)
1789 /* If the front end has decided that this needs to be passed by
1790 reference, do so. */
1791 if ((TREE_CODE (exp) == PARM_DECL || TREE_CODE (exp) == RESULT_DECL)
1792 && DECL_BY_REFERENCE (exp))
1795 /* If the EXPression is a CALL_EXPR, honor DECL_BY_REFERENCE set on the
1796 called function RESULT_DECL, meaning the function returns in memory by
1797 invisible reference. This check lets front-ends not set TREE_ADDRESSABLE
1798 on the function type, which used to be the way to request such a return
1799 mechanism but might now be causing troubles at gimplification time if
1800 temporaries with the function type need to be created. */
1801 if (TREE_CODE (exp) == CALL_EXPR && fndecl && DECL_RESULT (fndecl)
1802 && DECL_BY_REFERENCE (DECL_RESULT (fndecl)))
1805 if (targetm.calls.return_in_memory (type, fntype))
1807 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
1808 and thus can't be returned in registers. */
1809 if (TREE_ADDRESSABLE (type))
1811 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
1813 /* Make sure we have suitable call-clobbered regs to return
1814 the value in; if not, we must return it in memory. */
1815 reg = hard_function_value (type, 0, fntype, 0);
1817 /* If we have something other than a REG (e.g. a PARALLEL), then assume
1822 regno = REGNO (reg);
1823 nregs = hard_regno_nregs[regno][TYPE_MODE (type)];
1824 for (i = 0; i < nregs; i++)
1825 if (! call_used_regs[regno + i])
1830 /* Return true if we should assign DECL a pseudo register; false if it
1831 should live on the local stack. */
1834 use_register_for_decl (const_tree decl)
1836 if (!targetm.calls.allocate_stack_slots_for_args())
1839 /* Honor volatile. */
1840 if (TREE_SIDE_EFFECTS (decl))
1843 /* Honor addressability. */
1844 if (TREE_ADDRESSABLE (decl))
1847 /* Only register-like things go in registers. */
1848 if (DECL_MODE (decl) == BLKmode)
1851 /* If -ffloat-store specified, don't put explicit float variables
1853 /* ??? This should be checked after DECL_ARTIFICIAL, but tree-ssa
1854 propagates values across these stores, and it probably shouldn't. */
1855 if (flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)))
1858 /* If we're not interested in tracking debugging information for
1859 this decl, then we can certainly put it in a register. */
1860 if (DECL_IGNORED_P (decl))
1863 return (optimize || DECL_REGISTER (decl));
1866 /* Return true if TYPE should be passed by invisible reference. */
1869 pass_by_reference (CUMULATIVE_ARGS *ca, enum machine_mode mode,
1870 tree type, bool named_arg)
1874 /* If this type contains non-trivial constructors, then it is
1875 forbidden for the middle-end to create any new copies. */
1876 if (TREE_ADDRESSABLE (type))
1879 /* GCC post 3.4 passes *all* variable sized types by reference. */
1880 if (!TYPE_SIZE (type) || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
1884 return targetm.calls.pass_by_reference (ca, mode, type, named_arg);
1887 /* Return true if TYPE, which is passed by reference, should be callee
1888 copied instead of caller copied. */
1891 reference_callee_copied (CUMULATIVE_ARGS *ca, enum machine_mode mode,
1892 tree type, bool named_arg)
1894 if (type && TREE_ADDRESSABLE (type))
1896 return targetm.calls.callee_copies (ca, mode, type, named_arg);
1899 /* Structures to communicate between the subroutines of assign_parms.
1900 The first holds data persistent across all parameters, the second
1901 is cleared out for each parameter. */
1903 struct assign_parm_data_all
1905 CUMULATIVE_ARGS args_so_far;
1906 struct args_size stack_args_size;
1907 tree function_result_decl;
1909 rtx first_conversion_insn;
1910 rtx last_conversion_insn;
1911 HOST_WIDE_INT pretend_args_size;
1912 HOST_WIDE_INT extra_pretend_bytes;
1913 int reg_parm_stack_space;
1916 struct assign_parm_data_one
1922 enum machine_mode nominal_mode;
1923 enum machine_mode passed_mode;
1924 enum machine_mode promoted_mode;
1925 struct locate_and_pad_arg_data locate;
1927 BOOL_BITFIELD named_arg : 1;
1928 BOOL_BITFIELD passed_pointer : 1;
1929 BOOL_BITFIELD on_stack : 1;
1930 BOOL_BITFIELD loaded_in_reg : 1;
1933 /* A subroutine of assign_parms. Initialize ALL. */
1936 assign_parms_initialize_all (struct assign_parm_data_all *all)
1940 memset (all, 0, sizeof (*all));
1942 fntype = TREE_TYPE (current_function_decl);
1944 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
1945 INIT_CUMULATIVE_INCOMING_ARGS (all->args_so_far, fntype, NULL_RTX);
1947 INIT_CUMULATIVE_ARGS (all->args_so_far, fntype, NULL_RTX,
1948 current_function_decl, -1);
1951 #ifdef REG_PARM_STACK_SPACE
1952 all->reg_parm_stack_space = REG_PARM_STACK_SPACE (current_function_decl);
1956 /* If ARGS contains entries with complex types, split the entry into two
1957 entries of the component type. Return a new list of substitutions are
1958 needed, else the old list. */
1961 split_complex_args (tree args)
1965 /* Before allocating memory, check for the common case of no complex. */
1966 for (p = args; p; p = TREE_CHAIN (p))
1968 tree type = TREE_TYPE (p);
1969 if (TREE_CODE (type) == COMPLEX_TYPE
1970 && targetm.calls.split_complex_arg (type))
1976 args = copy_list (args);
1978 for (p = args; p; p = TREE_CHAIN (p))
1980 tree type = TREE_TYPE (p);
1981 if (TREE_CODE (type) == COMPLEX_TYPE
1982 && targetm.calls.split_complex_arg (type))
1985 tree subtype = TREE_TYPE (type);
1986 bool addressable = TREE_ADDRESSABLE (p);
1988 /* Rewrite the PARM_DECL's type with its component. */
1989 TREE_TYPE (p) = subtype;
1990 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
1991 DECL_MODE (p) = VOIDmode;
1992 DECL_SIZE (p) = NULL;
1993 DECL_SIZE_UNIT (p) = NULL;
1994 /* If this arg must go in memory, put it in a pseudo here.
1995 We can't allow it to go in memory as per normal parms,
1996 because the usual place might not have the imag part
1997 adjacent to the real part. */
1998 DECL_ARTIFICIAL (p) = addressable;
1999 DECL_IGNORED_P (p) = addressable;
2000 TREE_ADDRESSABLE (p) = 0;
2003 /* Build a second synthetic decl. */
2004 decl = build_decl (PARM_DECL, NULL_TREE, subtype);
2005 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
2006 DECL_ARTIFICIAL (decl) = addressable;
2007 DECL_IGNORED_P (decl) = addressable;
2008 layout_decl (decl, 0);
2010 /* Splice it in; skip the new decl. */
2011 TREE_CHAIN (decl) = TREE_CHAIN (p);
2012 TREE_CHAIN (p) = decl;
2020 /* A subroutine of assign_parms. Adjust the parameter list to incorporate
2021 the hidden struct return argument, and (abi willing) complex args.
2022 Return the new parameter list. */
2025 assign_parms_augmented_arg_list (struct assign_parm_data_all *all)
2027 tree fndecl = current_function_decl;
2028 tree fntype = TREE_TYPE (fndecl);
2029 tree fnargs = DECL_ARGUMENTS (fndecl);
2031 /* If struct value address is treated as the first argument, make it so. */
2032 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
2033 && ! cfun->returns_pcc_struct
2034 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
2036 tree type = build_pointer_type (TREE_TYPE (fntype));
2039 decl = build_decl (PARM_DECL, NULL_TREE, type);
2040 DECL_ARG_TYPE (decl) = type;
2041 DECL_ARTIFICIAL (decl) = 1;
2042 DECL_IGNORED_P (decl) = 1;
2044 TREE_CHAIN (decl) = fnargs;
2046 all->function_result_decl = decl;
2049 all->orig_fnargs = fnargs;
2051 /* If the target wants to split complex arguments into scalars, do so. */
2052 if (targetm.calls.split_complex_arg)
2053 fnargs = split_complex_args (fnargs);
2058 /* A subroutine of assign_parms. Examine PARM and pull out type and mode
2059 data for the parameter. Incorporate ABI specifics such as pass-by-
2060 reference and type promotion. */
2063 assign_parm_find_data_types (struct assign_parm_data_all *all, tree parm,
2064 struct assign_parm_data_one *data)
2066 tree nominal_type, passed_type;
2067 enum machine_mode nominal_mode, passed_mode, promoted_mode;
2069 memset (data, 0, sizeof (*data));
2071 /* NAMED_ARG is a misnomer. We really mean 'non-variadic'. */
2073 data->named_arg = 1; /* No variadic parms. */
2074 else if (TREE_CHAIN (parm))
2075 data->named_arg = 1; /* Not the last non-variadic parm. */
2076 else if (targetm.calls.strict_argument_naming (&all->args_so_far))
2077 data->named_arg = 1; /* Only variadic ones are unnamed. */
2079 data->named_arg = 0; /* Treat as variadic. */
2081 nominal_type = TREE_TYPE (parm);
2082 passed_type = DECL_ARG_TYPE (parm);
2084 /* Look out for errors propagating this far. Also, if the parameter's
2085 type is void then its value doesn't matter. */
2086 if (TREE_TYPE (parm) == error_mark_node
2087 /* This can happen after weird syntax errors
2088 or if an enum type is defined among the parms. */
2089 || TREE_CODE (parm) != PARM_DECL
2090 || passed_type == NULL
2091 || VOID_TYPE_P (nominal_type))
2093 nominal_type = passed_type = void_type_node;
2094 nominal_mode = passed_mode = promoted_mode = VOIDmode;
2098 /* Find mode of arg as it is passed, and mode of arg as it should be
2099 during execution of this function. */
2100 passed_mode = TYPE_MODE (passed_type);
2101 nominal_mode = TYPE_MODE (nominal_type);
2103 /* If the parm is to be passed as a transparent union, use the type of
2104 the first field for the tests below. We have already verified that
2105 the modes are the same. */
2106 if (TREE_CODE (passed_type) == UNION_TYPE
2107 && TYPE_TRANSPARENT_UNION (passed_type))
2108 passed_type = TREE_TYPE (TYPE_FIELDS (passed_type));
2110 /* See if this arg was passed by invisible reference. */
2111 if (pass_by_reference (&all->args_so_far, passed_mode,
2112 passed_type, data->named_arg))
2114 passed_type = nominal_type = build_pointer_type (passed_type);
2115 data->passed_pointer = true;
2116 passed_mode = nominal_mode = Pmode;
2119 /* Find mode as it is passed by the ABI. */
2120 promoted_mode = passed_mode;
2121 if (targetm.calls.promote_function_args (TREE_TYPE (current_function_decl)))
2123 int unsignedp = TYPE_UNSIGNED (passed_type);
2124 promoted_mode = promote_mode (passed_type, promoted_mode,
2129 data->nominal_type = nominal_type;
2130 data->passed_type = passed_type;
2131 data->nominal_mode = nominal_mode;
2132 data->passed_mode = passed_mode;
2133 data->promoted_mode = promoted_mode;
2136 /* A subroutine of assign_parms. Invoke setup_incoming_varargs. */
2139 assign_parms_setup_varargs (struct assign_parm_data_all *all,
2140 struct assign_parm_data_one *data, bool no_rtl)
2142 int varargs_pretend_bytes = 0;
2144 targetm.calls.setup_incoming_varargs (&all->args_so_far,
2145 data->promoted_mode,
2147 &varargs_pretend_bytes, no_rtl);
2149 /* If the back-end has requested extra stack space, record how much is
2150 needed. Do not change pretend_args_size otherwise since it may be
2151 nonzero from an earlier partial argument. */
2152 if (varargs_pretend_bytes > 0)
2153 all->pretend_args_size = varargs_pretend_bytes;
2156 /* A subroutine of assign_parms. Set DATA->ENTRY_PARM corresponding to
2157 the incoming location of the current parameter. */
2160 assign_parm_find_entry_rtl (struct assign_parm_data_all *all,
2161 struct assign_parm_data_one *data)
2163 HOST_WIDE_INT pretend_bytes = 0;
2167 if (data->promoted_mode == VOIDmode)
2169 data->entry_parm = data->stack_parm = const0_rtx;
2173 #ifdef FUNCTION_INCOMING_ARG
2174 entry_parm = FUNCTION_INCOMING_ARG (all->args_so_far, data->promoted_mode,
2175 data->passed_type, data->named_arg);
2177 entry_parm = FUNCTION_ARG (all->args_so_far, data->promoted_mode,
2178 data->passed_type, data->named_arg);
2181 if (entry_parm == 0)
2182 data->promoted_mode = data->passed_mode;
2184 /* Determine parm's home in the stack, in case it arrives in the stack
2185 or we should pretend it did. Compute the stack position and rtx where
2186 the argument arrives and its size.
2188 There is one complexity here: If this was a parameter that would
2189 have been passed in registers, but wasn't only because it is
2190 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2191 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2192 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of 0
2193 as it was the previous time. */
2194 in_regs = entry_parm != 0;
2195 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2198 if (!in_regs && !data->named_arg)
2200 if (targetm.calls.pretend_outgoing_varargs_named (&all->args_so_far))
2203 #ifdef FUNCTION_INCOMING_ARG
2204 tem = FUNCTION_INCOMING_ARG (all->args_so_far, data->promoted_mode,
2205 data->passed_type, true);
2207 tem = FUNCTION_ARG (all->args_so_far, data->promoted_mode,
2208 data->passed_type, true);
2210 in_regs = tem != NULL;
2214 /* If this parameter was passed both in registers and in the stack, use
2215 the copy on the stack. */
2216 if (targetm.calls.must_pass_in_stack (data->promoted_mode,
2224 partial = targetm.calls.arg_partial_bytes (&all->args_so_far,
2225 data->promoted_mode,
2228 data->partial = partial;
2230 /* The caller might already have allocated stack space for the
2231 register parameters. */
2232 if (partial != 0 && all->reg_parm_stack_space == 0)
2234 /* Part of this argument is passed in registers and part
2235 is passed on the stack. Ask the prologue code to extend
2236 the stack part so that we can recreate the full value.
2238 PRETEND_BYTES is the size of the registers we need to store.
2239 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
2240 stack space that the prologue should allocate.
2242 Internally, gcc assumes that the argument pointer is aligned
2243 to STACK_BOUNDARY bits. This is used both for alignment
2244 optimizations (see init_emit) and to locate arguments that are
2245 aligned to more than PARM_BOUNDARY bits. We must preserve this
2246 invariant by rounding CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to
2247 a stack boundary. */
2249 /* We assume at most one partial arg, and it must be the first
2250 argument on the stack. */
2251 gcc_assert (!all->extra_pretend_bytes && !all->pretend_args_size);
2253 pretend_bytes = partial;
2254 all->pretend_args_size = CEIL_ROUND (pretend_bytes, STACK_BYTES);
2256 /* We want to align relative to the actual stack pointer, so
2257 don't include this in the stack size until later. */
2258 all->extra_pretend_bytes = all->pretend_args_size;
2262 locate_and_pad_parm (data->promoted_mode, data->passed_type, in_regs,
2263 entry_parm ? data->partial : 0, current_function_decl,
2264 &all->stack_args_size, &data->locate);
2266 /* Update parm_stack_boundary if this parameter is passed in the
2268 if (!in_regs && crtl->parm_stack_boundary < data->locate.boundary)
2269 crtl->parm_stack_boundary = data->locate.boundary;
2271 /* Adjust offsets to include the pretend args. */
2272 pretend_bytes = all->extra_pretend_bytes - pretend_bytes;
2273 data->locate.slot_offset.constant += pretend_bytes;
2274 data->locate.offset.constant += pretend_bytes;
2276 data->entry_parm = entry_parm;
2279 /* A subroutine of assign_parms. If there is actually space on the stack
2280 for this parm, count it in stack_args_size and return true. */
2283 assign_parm_is_stack_parm (struct assign_parm_data_all *all,
2284 struct assign_parm_data_one *data)
2286 /* Trivially true if we've no incoming register. */
2287 if (data->entry_parm == NULL)
2289 /* Also true if we're partially in registers and partially not,
2290 since we've arranged to drop the entire argument on the stack. */
2291 else if (data->partial != 0)
2293 /* Also true if the target says that it's passed in both registers
2294 and on the stack. */
2295 else if (GET_CODE (data->entry_parm) == PARALLEL
2296 && XEXP (XVECEXP (data->entry_parm, 0, 0), 0) == NULL_RTX)
2298 /* Also true if the target says that there's stack allocated for
2299 all register parameters. */
2300 else if (all->reg_parm_stack_space > 0)
2302 /* Otherwise, no, this parameter has no ABI defined stack slot. */
2306 all->stack_args_size.constant += data->locate.size.constant;
2307 if (data->locate.size.var)
2308 ADD_PARM_SIZE (all->stack_args_size, data->locate.size.var);
2313 /* A subroutine of assign_parms. Given that this parameter is allocated
2314 stack space by the ABI, find it. */
2317 assign_parm_find_stack_rtl (tree parm, struct assign_parm_data_one *data)
2319 rtx offset_rtx, stack_parm;
2320 unsigned int align, boundary;
2322 /* If we're passing this arg using a reg, make its stack home the
2323 aligned stack slot. */
2324 if (data->entry_parm)
2325 offset_rtx = ARGS_SIZE_RTX (data->locate.slot_offset);
2327 offset_rtx = ARGS_SIZE_RTX (data->locate.offset);
2329 stack_parm = crtl->args.internal_arg_pointer;
2330 if (offset_rtx != const0_rtx)
2331 stack_parm = gen_rtx_PLUS (Pmode, stack_parm, offset_rtx);
2332 stack_parm = gen_rtx_MEM (data->promoted_mode, stack_parm);
2334 set_mem_attributes (stack_parm, parm, 1);
2336 boundary = data->locate.boundary;
2337 align = BITS_PER_UNIT;
2339 /* If we're padding upward, we know that the alignment of the slot
2340 is FUNCTION_ARG_BOUNDARY. If we're using slot_offset, we're
2341 intentionally forcing upward padding. Otherwise we have to come
2342 up with a guess at the alignment based on OFFSET_RTX. */
2343 if (data->locate.where_pad != downward || data->entry_parm)
2345 else if (GET_CODE (offset_rtx) == CONST_INT)
2347 align = INTVAL (offset_rtx) * BITS_PER_UNIT | boundary;
2348 align = align & -align;
2350 set_mem_align (stack_parm, align);
2352 if (data->entry_parm)
2353 set_reg_attrs_for_parm (data->entry_parm, stack_parm);
2355 data->stack_parm = stack_parm;
2358 /* A subroutine of assign_parms. Adjust DATA->ENTRY_RTL such that it's
2359 always valid and contiguous. */
2362 assign_parm_adjust_entry_rtl (struct assign_parm_data_one *data)
2364 rtx entry_parm = data->entry_parm;
2365 rtx stack_parm = data->stack_parm;
2367 /* If this parm was passed part in regs and part in memory, pretend it
2368 arrived entirely in memory by pushing the register-part onto the stack.
2369 In the special case of a DImode or DFmode that is split, we could put
2370 it together in a pseudoreg directly, but for now that's not worth
2372 if (data->partial != 0)
2374 /* Handle calls that pass values in multiple non-contiguous
2375 locations. The Irix 6 ABI has examples of this. */
2376 if (GET_CODE (entry_parm) == PARALLEL)
2377 emit_group_store (validize_mem (stack_parm), entry_parm,
2379 int_size_in_bytes (data->passed_type));
2382 gcc_assert (data->partial % UNITS_PER_WORD == 0);
2383 move_block_from_reg (REGNO (entry_parm), validize_mem (stack_parm),
2384 data->partial / UNITS_PER_WORD);
2387 entry_parm = stack_parm;
2390 /* If we didn't decide this parm came in a register, by default it came
2392 else if (entry_parm == NULL)
2393 entry_parm = stack_parm;
2395 /* When an argument is passed in multiple locations, we can't make use
2396 of this information, but we can save some copying if the whole argument
2397 is passed in a single register. */
2398 else if (GET_CODE (entry_parm) == PARALLEL
2399 && data->nominal_mode != BLKmode
2400 && data->passed_mode != BLKmode)
2402 size_t i, len = XVECLEN (entry_parm, 0);
2404 for (i = 0; i < len; i++)
2405 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
2406 && REG_P (XEXP (XVECEXP (entry_parm, 0, i), 0))
2407 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
2408 == data->passed_mode)
2409 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
2411 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
2416 data->entry_parm = entry_parm;
2419 /* A subroutine of assign_parms. Reconstitute any values which were
2420 passed in multiple registers and would fit in a single register. */
2423 assign_parm_remove_parallels (struct assign_parm_data_one *data)
2425 rtx entry_parm = data->entry_parm;
2427 /* Convert the PARALLEL to a REG of the same mode as the parallel.
2428 This can be done with register operations rather than on the
2429 stack, even if we will store the reconstituted parameter on the
2431 if (GET_CODE (entry_parm) == PARALLEL && GET_MODE (entry_parm) != BLKmode)
2433 rtx parmreg = gen_reg_rtx (GET_MODE (entry_parm));
2434 emit_group_store (parmreg, entry_parm, NULL_TREE,
2435 GET_MODE_SIZE (GET_MODE (entry_parm)));
2436 entry_parm = parmreg;
2439 data->entry_parm = entry_parm;
2442 /* A subroutine of assign_parms. Adjust DATA->STACK_RTL such that it's
2443 always valid and properly aligned. */
2446 assign_parm_adjust_stack_rtl (struct assign_parm_data_one *data)
2448 rtx stack_parm = data->stack_parm;
2450 /* If we can't trust the parm stack slot to be aligned enough for its
2451 ultimate type, don't use that slot after entry. We'll make another
2452 stack slot, if we need one. */
2454 && ((STRICT_ALIGNMENT
2455 && GET_MODE_ALIGNMENT (data->nominal_mode) > MEM_ALIGN (stack_parm))
2456 || (data->nominal_type
2457 && TYPE_ALIGN (data->nominal_type) > MEM_ALIGN (stack_parm)
2458 && MEM_ALIGN (stack_parm) < PREFERRED_STACK_BOUNDARY)))
2461 /* If parm was passed in memory, and we need to convert it on entry,
2462 don't store it back in that same slot. */
2463 else if (data->entry_parm == stack_parm
2464 && data->nominal_mode != BLKmode
2465 && data->nominal_mode != data->passed_mode)
2468 /* If stack protection is in effect for this function, don't leave any
2469 pointers in their passed stack slots. */
2470 else if (crtl->stack_protect_guard
2471 && (flag_stack_protect == 2
2472 || data->passed_pointer
2473 || POINTER_TYPE_P (data->nominal_type)))
2476 data->stack_parm = stack_parm;
2479 /* A subroutine of assign_parms. Return true if the current parameter
2480 should be stored as a BLKmode in the current frame. */
2483 assign_parm_setup_block_p (struct assign_parm_data_one *data)
2485 if (data->nominal_mode == BLKmode)
2487 if (GET_MODE (data->entry_parm) == BLKmode)
2490 #ifdef BLOCK_REG_PADDING
2491 /* Only assign_parm_setup_block knows how to deal with register arguments
2492 that are padded at the least significant end. */
2493 if (REG_P (data->entry_parm)
2494 && GET_MODE_SIZE (data->promoted_mode) < UNITS_PER_WORD
2495 && (BLOCK_REG_PADDING (data->passed_mode, data->passed_type, 1)
2496 == (BYTES_BIG_ENDIAN ? upward : downward)))
2503 /* A subroutine of assign_parms. Arrange for the parameter to be
2504 present and valid in DATA->STACK_RTL. */
2507 assign_parm_setup_block (struct assign_parm_data_all *all,
2508 tree parm, struct assign_parm_data_one *data)
2510 rtx entry_parm = data->entry_parm;
2511 rtx stack_parm = data->stack_parm;
2513 HOST_WIDE_INT size_stored;
2515 if (GET_CODE (entry_parm) == PARALLEL)
2516 entry_parm = emit_group_move_into_temps (entry_parm);
2518 size = int_size_in_bytes (data->passed_type);
2519 size_stored = CEIL_ROUND (size, UNITS_PER_WORD);
2520 if (stack_parm == 0)
2522 DECL_ALIGN (parm) = MAX (DECL_ALIGN (parm), BITS_PER_WORD);
2523 stack_parm = assign_stack_local (BLKmode, size_stored,
2525 if (GET_MODE_SIZE (GET_MODE (entry_parm)) == size)
2526 PUT_MODE (stack_parm, GET_MODE (entry_parm));
2527 set_mem_attributes (stack_parm, parm, 1);
2530 /* If a BLKmode arrives in registers, copy it to a stack slot. Handle
2531 calls that pass values in multiple non-contiguous locations. */
2532 if (REG_P (entry_parm) || GET_CODE (entry_parm) == PARALLEL)
2536 /* Note that we will be storing an integral number of words.
2537 So we have to be careful to ensure that we allocate an
2538 integral number of words. We do this above when we call
2539 assign_stack_local if space was not allocated in the argument
2540 list. If it was, this will not work if PARM_BOUNDARY is not
2541 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2542 if it becomes a problem. Exception is when BLKmode arrives
2543 with arguments not conforming to word_mode. */
2545 if (data->stack_parm == 0)
2547 else if (GET_CODE (entry_parm) == PARALLEL)
2550 gcc_assert (!size || !(PARM_BOUNDARY % BITS_PER_WORD));
2552 mem = validize_mem (stack_parm);
2554 /* Handle values in multiple non-contiguous locations. */
2555 if (GET_CODE (entry_parm) == PARALLEL)
2557 push_to_sequence2 (all->first_conversion_insn,
2558 all->last_conversion_insn);
2559 emit_group_store (mem, entry_parm, data->passed_type, size);
2560 all->first_conversion_insn = get_insns ();
2561 all->last_conversion_insn = get_last_insn ();
2568 /* If SIZE is that of a mode no bigger than a word, just use
2569 that mode's store operation. */
2570 else if (size <= UNITS_PER_WORD)
2572 enum machine_mode mode
2573 = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
2576 #ifdef BLOCK_REG_PADDING
2577 && (size == UNITS_PER_WORD
2578 || (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2579 != (BYTES_BIG_ENDIAN ? upward : downward)))
2585 /* We are really truncating a word_mode value containing
2586 SIZE bytes into a value of mode MODE. If such an
2587 operation requires no actual instructions, we can refer
2588 to the value directly in mode MODE, otherwise we must
2589 start with the register in word_mode and explicitly
2591 if (TRULY_NOOP_TRUNCATION (size * BITS_PER_UNIT, BITS_PER_WORD))
2592 reg = gen_rtx_REG (mode, REGNO (entry_parm));
2595 reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
2596 reg = convert_to_mode (mode, copy_to_reg (reg), 1);
2598 emit_move_insn (change_address (mem, mode, 0), reg);
2601 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
2602 machine must be aligned to the left before storing
2603 to memory. Note that the previous test doesn't
2604 handle all cases (e.g. SIZE == 3). */
2605 else if (size != UNITS_PER_WORD
2606 #ifdef BLOCK_REG_PADDING
2607 && (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2615 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
2616 rtx reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
2618 x = expand_shift (LSHIFT_EXPR, word_mode, reg,
2619 build_int_cst (NULL_TREE, by),
2621 tem = change_address (mem, word_mode, 0);
2622 emit_move_insn (tem, x);
2625 move_block_from_reg (REGNO (entry_parm), mem,
2626 size_stored / UNITS_PER_WORD);
2629 move_block_from_reg (REGNO (entry_parm), mem,
2630 size_stored / UNITS_PER_WORD);
2632 else if (data->stack_parm == 0)
2634 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2635 emit_block_move (stack_parm, data->entry_parm, GEN_INT (size),
2637 all->first_conversion_insn = get_insns ();
2638 all->last_conversion_insn = get_last_insn ();
2642 data->stack_parm = stack_parm;
2643 SET_DECL_RTL (parm, stack_parm);
2646 /* A subroutine of assign_parms. Allocate a pseudo to hold the current
2647 parameter. Get it there. Perform all ABI specified conversions. */
2650 assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm,
2651 struct assign_parm_data_one *data)
2654 enum machine_mode promoted_nominal_mode;
2655 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (parm));
2656 bool did_conversion = false;
2658 /* Store the parm in a pseudoregister during the function, but we may
2659 need to do it in a wider mode. */
2661 /* This is not really promoting for a call. However we need to be
2662 consistent with assign_parm_find_data_types and expand_expr_real_1. */
2663 promoted_nominal_mode
2664 = promote_mode (data->nominal_type, data->nominal_mode, &unsignedp, 1);
2666 parmreg = gen_reg_rtx (promoted_nominal_mode);
2668 if (!DECL_ARTIFICIAL (parm))
2669 mark_user_reg (parmreg);
2671 /* If this was an item that we received a pointer to,
2672 set DECL_RTL appropriately. */
2673 if (data->passed_pointer)
2675 rtx x = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data->passed_type)), parmreg);
2676 set_mem_attributes (x, parm, 1);
2677 SET_DECL_RTL (parm, x);
2680 SET_DECL_RTL (parm, parmreg);
2682 assign_parm_remove_parallels (data);
2684 /* Copy the value into the register. */
2685 if (data->nominal_mode != data->passed_mode
2686 || promoted_nominal_mode != data->promoted_mode)
2690 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
2691 mode, by the caller. We now have to convert it to
2692 NOMINAL_MODE, if different. However, PARMREG may be in
2693 a different mode than NOMINAL_MODE if it is being stored
2696 If ENTRY_PARM is a hard register, it might be in a register
2697 not valid for operating in its mode (e.g., an odd-numbered
2698 register for a DFmode). In that case, moves are the only
2699 thing valid, so we can't do a convert from there. This
2700 occurs when the calling sequence allow such misaligned
2703 In addition, the conversion may involve a call, which could
2704 clobber parameters which haven't been copied to pseudo
2705 registers yet. Therefore, we must first copy the parm to
2706 a pseudo reg here, and save the conversion until after all
2707 parameters have been moved. */
2709 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
2711 emit_move_insn (tempreg, validize_mem (data->entry_parm));
2713 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2714 tempreg = convert_to_mode (data->nominal_mode, tempreg, unsignedp);
2716 if (GET_CODE (tempreg) == SUBREG
2717 && GET_MODE (tempreg) == data->nominal_mode
2718 && REG_P (SUBREG_REG (tempreg))
2719 && data->nominal_mode == data->passed_mode
2720 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (data->entry_parm)
2721 && GET_MODE_SIZE (GET_MODE (tempreg))
2722 < GET_MODE_SIZE (GET_MODE (data->entry_parm)))
2724 /* The argument is already sign/zero extended, so note it
2726 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
2727 SUBREG_PROMOTED_UNSIGNED_SET (tempreg, unsignedp);
2730 /* TREE_USED gets set erroneously during expand_assignment. */
2731 save_tree_used = TREE_USED (parm);
2732 expand_assignment (parm, make_tree (data->nominal_type, tempreg), false);
2733 TREE_USED (parm) = save_tree_used;
2734 all->first_conversion_insn = get_insns ();
2735 all->last_conversion_insn = get_last_insn ();
2738 did_conversion = true;
2741 emit_move_insn (parmreg, validize_mem (data->entry_parm));
2743 /* If we were passed a pointer but the actual value can safely live
2744 in a register, put it in one. */
2745 if (data->passed_pointer
2746 && TYPE_MODE (TREE_TYPE (parm)) != BLKmode
2747 /* If by-reference argument was promoted, demote it. */
2748 && (TYPE_MODE (TREE_TYPE (parm)) != GET_MODE (DECL_RTL (parm))
2749 || use_register_for_decl (parm)))
2751 /* We can't use nominal_mode, because it will have been set to
2752 Pmode above. We must use the actual mode of the parm. */
2753 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
2754 mark_user_reg (parmreg);
2756 if (GET_MODE (parmreg) != GET_MODE (DECL_RTL (parm)))
2758 rtx tempreg = gen_reg_rtx (GET_MODE (DECL_RTL (parm)));
2759 int unsigned_p = TYPE_UNSIGNED (TREE_TYPE (parm));
2761 push_to_sequence2 (all->first_conversion_insn,
2762 all->last_conversion_insn);
2763 emit_move_insn (tempreg, DECL_RTL (parm));
2764 tempreg = convert_to_mode (GET_MODE (parmreg), tempreg, unsigned_p);
2765 emit_move_insn (parmreg, tempreg);
2766 all->first_conversion_insn = get_insns ();
2767 all->last_conversion_insn = get_last_insn ();
2770 did_conversion = true;
2773 emit_move_insn (parmreg, DECL_RTL (parm));
2775 SET_DECL_RTL (parm, parmreg);
2777 /* STACK_PARM is the pointer, not the parm, and PARMREG is
2779 data->stack_parm = NULL;
2782 /* Mark the register as eliminable if we did no conversion and it was
2783 copied from memory at a fixed offset, and the arg pointer was not
2784 copied to a pseudo-reg. If the arg pointer is a pseudo reg or the
2785 offset formed an invalid address, such memory-equivalences as we
2786 make here would screw up life analysis for it. */
2787 if (data->nominal_mode == data->passed_mode
2789 && data->stack_parm != 0
2790 && MEM_P (data->stack_parm)
2791 && data->locate.offset.var == 0
2792 && reg_mentioned_p (virtual_incoming_args_rtx,
2793 XEXP (data->stack_parm, 0)))
2795 rtx linsn = get_last_insn ();
2798 /* Mark complex types separately. */
2799 if (GET_CODE (parmreg) == CONCAT)
2801 enum machine_mode submode
2802 = GET_MODE_INNER (GET_MODE (parmreg));
2803 int regnor = REGNO (XEXP (parmreg, 0));
2804 int regnoi = REGNO (XEXP (parmreg, 1));
2805 rtx stackr = adjust_address_nv (data->stack_parm, submode, 0);
2806 rtx stacki = adjust_address_nv (data->stack_parm, submode,
2807 GET_MODE_SIZE (submode));
2809 /* Scan backwards for the set of the real and
2811 for (sinsn = linsn; sinsn != 0;
2812 sinsn = prev_nonnote_insn (sinsn))
2814 set = single_set (sinsn);
2818 if (SET_DEST (set) == regno_reg_rtx [regnoi])
2819 set_unique_reg_note (sinsn, REG_EQUIV, stacki);
2820 else if (SET_DEST (set) == regno_reg_rtx [regnor])
2821 set_unique_reg_note (sinsn, REG_EQUIV, stackr);
2824 else if ((set = single_set (linsn)) != 0
2825 && SET_DEST (set) == parmreg)
2826 set_unique_reg_note (linsn, REG_EQUIV, data->stack_parm);
2829 /* For pointer data type, suggest pointer register. */
2830 if (POINTER_TYPE_P (TREE_TYPE (parm)))
2831 mark_reg_pointer (parmreg,
2832 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
2835 /* A subroutine of assign_parms. Allocate stack space to hold the current
2836 parameter. Get it there. Perform all ABI specified conversions. */
2839 assign_parm_setup_stack (struct assign_parm_data_all *all, tree parm,
2840 struct assign_parm_data_one *data)
2842 /* Value must be stored in the stack slot STACK_PARM during function
2844 bool to_conversion = false;
2846 assign_parm_remove_parallels (data);
2848 if (data->promoted_mode != data->nominal_mode)
2850 /* Conversion is required. */
2851 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
2853 emit_move_insn (tempreg, validize_mem (data->entry_parm));
2855 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2856 to_conversion = true;
2858 data->entry_parm = convert_to_mode (data->nominal_mode, tempreg,
2859 TYPE_UNSIGNED (TREE_TYPE (parm)));
2861 if (data->stack_parm)
2862 /* ??? This may need a big-endian conversion on sparc64. */
2864 = adjust_address (data->stack_parm, data->nominal_mode, 0);
2867 if (data->entry_parm != data->stack_parm)
2871 if (data->stack_parm == 0)
2874 = assign_stack_local (GET_MODE (data->entry_parm),
2875 GET_MODE_SIZE (GET_MODE (data->entry_parm)),
2876 TYPE_ALIGN (data->passed_type));
2877 set_mem_attributes (data->stack_parm, parm, 1);
2880 dest = validize_mem (data->stack_parm);
2881 src = validize_mem (data->entry_parm);
2885 /* Use a block move to handle potentially misaligned entry_parm. */
2887 push_to_sequence2 (all->first_conversion_insn,
2888 all->last_conversion_insn);
2889 to_conversion = true;
2891 emit_block_move (dest, src,
2892 GEN_INT (int_size_in_bytes (data->passed_type)),
2896 emit_move_insn (dest, src);
2901 all->first_conversion_insn = get_insns ();
2902 all->last_conversion_insn = get_last_insn ();
2906 SET_DECL_RTL (parm, data->stack_parm);
2909 /* A subroutine of assign_parms. If the ABI splits complex arguments, then
2910 undo the frobbing that we did in assign_parms_augmented_arg_list. */
2913 assign_parms_unsplit_complex (struct assign_parm_data_all *all, tree fnargs)
2916 tree orig_fnargs = all->orig_fnargs;
2918 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm))
2920 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
2921 && targetm.calls.split_complex_arg (TREE_TYPE (parm)))
2923 rtx tmp, real, imag;
2924 enum machine_mode inner = GET_MODE_INNER (DECL_MODE (parm));
2926 real = DECL_RTL (fnargs);
2927 imag = DECL_RTL (TREE_CHAIN (fnargs));
2928 if (inner != GET_MODE (real))
2930 real = gen_lowpart_SUBREG (inner, real);
2931 imag = gen_lowpart_SUBREG (inner, imag);
2934 if (TREE_ADDRESSABLE (parm))
2937 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (parm));
2939 /* split_complex_arg put the real and imag parts in
2940 pseudos. Move them to memory. */
2941 tmp = assign_stack_local (DECL_MODE (parm), size,
2942 TYPE_ALIGN (TREE_TYPE (parm)));
2943 set_mem_attributes (tmp, parm, 1);
2944 rmem = adjust_address_nv (tmp, inner, 0);
2945 imem = adjust_address_nv (tmp, inner, GET_MODE_SIZE (inner));
2946 push_to_sequence2 (all->first_conversion_insn,
2947 all->last_conversion_insn);
2948 emit_move_insn (rmem, real);
2949 emit_move_insn (imem, imag);
2950 all->first_conversion_insn = get_insns ();
2951 all->last_conversion_insn = get_last_insn ();
2955 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
2956 SET_DECL_RTL (parm, tmp);
2958 real = DECL_INCOMING_RTL (fnargs);
2959 imag = DECL_INCOMING_RTL (TREE_CHAIN (fnargs));
2960 if (inner != GET_MODE (real))
2962 real = gen_lowpart_SUBREG (inner, real);
2963 imag = gen_lowpart_SUBREG (inner, imag);
2965 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
2966 set_decl_incoming_rtl (parm, tmp, false);
2967 fnargs = TREE_CHAIN (fnargs);
2971 SET_DECL_RTL (parm, DECL_RTL (fnargs));
2972 set_decl_incoming_rtl (parm, DECL_INCOMING_RTL (fnargs), false);
2974 /* Set MEM_EXPR to the original decl, i.e. to PARM,
2975 instead of the copy of decl, i.e. FNARGS. */
2976 if (DECL_INCOMING_RTL (parm) && MEM_P (DECL_INCOMING_RTL (parm)))
2977 set_mem_expr (DECL_INCOMING_RTL (parm), parm);
2980 fnargs = TREE_CHAIN (fnargs);
2984 /* Assign RTL expressions to the function's parameters. This may involve
2985 copying them into registers and using those registers as the DECL_RTL. */
2988 assign_parms (tree fndecl)
2990 struct assign_parm_data_all all;
2993 crtl->args.internal_arg_pointer
2994 = targetm.calls.internal_arg_pointer ();
2996 assign_parms_initialize_all (&all);
2997 fnargs = assign_parms_augmented_arg_list (&all);
2999 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
3001 struct assign_parm_data_one data;
3003 /* Extract the type of PARM; adjust it according to ABI. */
3004 assign_parm_find_data_types (&all, parm, &data);
3006 /* Early out for errors and void parameters. */
3007 if (data.passed_mode == VOIDmode)
3009 SET_DECL_RTL (parm, const0_rtx);
3010 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
3014 /* Estimate stack alignment from parameter alignment. */
3015 if (SUPPORTS_STACK_ALIGNMENT)
3017 unsigned int align = FUNCTION_ARG_BOUNDARY (data.promoted_mode,
3019 if (TYPE_ALIGN (data.nominal_type) > align)
3020 align = TYPE_ALIGN (data.passed_type);
3021 if (crtl->stack_alignment_estimated < align)
3023 gcc_assert (!crtl->stack_realign_processed);
3024 crtl->stack_alignment_estimated = align;
3028 if (cfun->stdarg && !TREE_CHAIN (parm))
3029 assign_parms_setup_varargs (&all, &data, false);
3031 /* Find out where the parameter arrives in this function. */
3032 assign_parm_find_entry_rtl (&all, &data);
3034 /* Find out where stack space for this parameter might be. */
3035 if (assign_parm_is_stack_parm (&all, &data))
3037 assign_parm_find_stack_rtl (parm, &data);
3038 assign_parm_adjust_entry_rtl (&data);
3041 /* Record permanently how this parm was passed. */
3042 set_decl_incoming_rtl (parm, data.entry_parm, data.passed_pointer);
3044 /* Update info on where next arg arrives in registers. */
3045 FUNCTION_ARG_ADVANCE (all.args_so_far, data.promoted_mode,
3046 data.passed_type, data.named_arg);
3048 assign_parm_adjust_stack_rtl (&data);
3050 if (assign_parm_setup_block_p (&data))
3051 assign_parm_setup_block (&all, parm, &data);
3052 else if (data.passed_pointer || use_register_for_decl (parm))
3053 assign_parm_setup_reg (&all, parm, &data);
3055 assign_parm_setup_stack (&all, parm, &data);
3058 if (targetm.calls.split_complex_arg && fnargs != all.orig_fnargs)
3059 assign_parms_unsplit_complex (&all, fnargs);
3061 /* Output all parameter conversion instructions (possibly including calls)
3062 now that all parameters have been copied out of hard registers. */
3063 emit_insn (all.first_conversion_insn);
3065 /* Estimate reload stack alignment from scalar return mode. */
3066 if (SUPPORTS_STACK_ALIGNMENT)
3068 if (DECL_RESULT (fndecl))
3070 tree type = TREE_TYPE (DECL_RESULT (fndecl));
3071 enum machine_mode mode = TYPE_MODE (type);
3075 && !AGGREGATE_TYPE_P (type))
3077 unsigned int align = GET_MODE_ALIGNMENT (mode);
3078 if (crtl->stack_alignment_estimated < align)
3080 gcc_assert (!crtl->stack_realign_processed);
3081 crtl->stack_alignment_estimated = align;
3087 /* If we are receiving a struct value address as the first argument, set up
3088 the RTL for the function result. As this might require code to convert
3089 the transmitted address to Pmode, we do this here to ensure that possible
3090 preliminary conversions of the address have been emitted already. */
3091 if (all.function_result_decl)
3093 tree result = DECL_RESULT (current_function_decl);
3094 rtx addr = DECL_RTL (all.function_result_decl);
3097 if (DECL_BY_REFERENCE (result))
3101 addr = convert_memory_address (Pmode, addr);
3102 x = gen_rtx_MEM (DECL_MODE (result), addr);
3103 set_mem_attributes (x, result, 1);
3105 SET_DECL_RTL (result, x);
3108 /* We have aligned all the args, so add space for the pretend args. */
3109 crtl->args.pretend_args_size = all.pretend_args_size;
3110 all.stack_args_size.constant += all.extra_pretend_bytes;
3111 crtl->args.size = all.stack_args_size.constant;
3113 /* Adjust function incoming argument size for alignment and
3116 #ifdef REG_PARM_STACK_SPACE
3117 crtl->args.size = MAX (crtl->args.size,
3118 REG_PARM_STACK_SPACE (fndecl));
3121 crtl->args.size = CEIL_ROUND (crtl->args.size,
3122 PARM_BOUNDARY / BITS_PER_UNIT);
3124 #ifdef ARGS_GROW_DOWNWARD
3125 crtl->args.arg_offset_rtx
3126 = (all.stack_args_size.var == 0 ? GEN_INT (-all.stack_args_size.constant)
3127 : expand_expr (size_diffop (all.stack_args_size.var,
3128 size_int (-all.stack_args_size.constant)),
3129 NULL_RTX, VOIDmode, 0));
3131 crtl->args.arg_offset_rtx = ARGS_SIZE_RTX (all.stack_args_size);
3134 /* See how many bytes, if any, of its args a function should try to pop
3137 crtl->args.pops_args = RETURN_POPS_ARGS (fndecl, TREE_TYPE (fndecl),
3140 /* For stdarg.h function, save info about
3141 regs and stack space used by the named args. */
3143 crtl->args.info = all.args_so_far;
3145 /* Set the rtx used for the function return value. Put this in its
3146 own variable so any optimizers that need this information don't have
3147 to include tree.h. Do this here so it gets done when an inlined
3148 function gets output. */
3151 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
3152 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
3154 /* If scalar return value was computed in a pseudo-reg, or was a named
3155 return value that got dumped to the stack, copy that to the hard
3157 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
3159 tree decl_result = DECL_RESULT (fndecl);
3160 rtx decl_rtl = DECL_RTL (decl_result);
3162 if (REG_P (decl_rtl)
3163 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
3164 : DECL_REGISTER (decl_result))
3168 real_decl_rtl = targetm.calls.function_value (TREE_TYPE (decl_result),
3170 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
3171 /* The delay slot scheduler assumes that crtl->return_rtx
3172 holds the hard register containing the return value, not a
3173 temporary pseudo. */
3174 crtl->return_rtx = real_decl_rtl;
3179 /* A subroutine of gimplify_parameters, invoked via walk_tree.
3180 For all seen types, gimplify their sizes. */
3183 gimplify_parm_type (tree *tp, int *walk_subtrees, void *data)
3190 if (POINTER_TYPE_P (t))
3192 else if (TYPE_SIZE (t) && !TREE_CONSTANT (TYPE_SIZE (t))
3193 && !TYPE_SIZES_GIMPLIFIED (t))
3195 gimplify_type_sizes (t, (gimple_seq *) data);
3203 /* Gimplify the parameter list for current_function_decl. This involves
3204 evaluating SAVE_EXPRs of variable sized parameters and generating code
3205 to implement callee-copies reference parameters. Returns a sequence of
3206 statements to add to the beginning of the function. */
3209 gimplify_parameters (void)
3211 struct assign_parm_data_all all;
3213 gimple_seq stmts = NULL;
3215 assign_parms_initialize_all (&all);
3216 fnargs = assign_parms_augmented_arg_list (&all);
3218 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
3220 struct assign_parm_data_one data;
3222 /* Extract the type of PARM; adjust it according to ABI. */
3223 assign_parm_find_data_types (&all, parm, &data);
3225 /* Early out for errors and void parameters. */
3226 if (data.passed_mode == VOIDmode || DECL_SIZE (parm) == NULL)
3229 /* Update info on where next arg arrives in registers. */
3230 FUNCTION_ARG_ADVANCE (all.args_so_far, data.promoted_mode,
3231 data.passed_type, data.named_arg);
3233 /* ??? Once upon a time variable_size stuffed parameter list
3234 SAVE_EXPRs (amongst others) onto a pending sizes list. This
3235 turned out to be less than manageable in the gimple world.
3236 Now we have to hunt them down ourselves. */
3237 walk_tree_without_duplicates (&data.passed_type,
3238 gimplify_parm_type, &stmts);
3240 if (TREE_CODE (DECL_SIZE_UNIT (parm)) != INTEGER_CST)
3242 gimplify_one_sizepos (&DECL_SIZE (parm), &stmts);
3243 gimplify_one_sizepos (&DECL_SIZE_UNIT (parm), &stmts);
3246 if (data.passed_pointer)
3248 tree type = TREE_TYPE (data.passed_type);
3249 if (reference_callee_copied (&all.args_so_far, TYPE_MODE (type),
3250 type, data.named_arg))
3254 /* For constant-sized objects, this is trivial; for
3255 variable-sized objects, we have to play games. */
3256 if (TREE_CODE (DECL_SIZE_UNIT (parm)) == INTEGER_CST
3257 && !(flag_stack_check == GENERIC_STACK_CHECK
3258 && compare_tree_int (DECL_SIZE_UNIT (parm),
3259 STACK_CHECK_MAX_VAR_SIZE) > 0))
3261 local = create_tmp_var (type, get_name (parm));
3262 DECL_IGNORED_P (local) = 0;
3266 tree ptr_type, addr;
3268 ptr_type = build_pointer_type (type);
3269 addr = create_tmp_var (ptr_type, get_name (parm));
3270 DECL_IGNORED_P (addr) = 0;
3271 local = build_fold_indirect_ref (addr);
3273 t = built_in_decls[BUILT_IN_ALLOCA];
3274 t = build_call_expr (t, 1, DECL_SIZE_UNIT (parm));
3275 t = fold_convert (ptr_type, t);
3276 t = build2 (MODIFY_EXPR, TREE_TYPE (addr), addr, t);
3277 gimplify_and_add (t, &stmts);
3280 gimplify_assign (local, parm, &stmts);
3282 SET_DECL_VALUE_EXPR (parm, local);
3283 DECL_HAS_VALUE_EXPR_P (parm) = 1;
3291 /* Compute the size and offset from the start of the stacked arguments for a
3292 parm passed in mode PASSED_MODE and with type TYPE.
3294 INITIAL_OFFSET_PTR points to the current offset into the stacked
3297 The starting offset and size for this parm are returned in
3298 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
3299 nonzero, the offset is that of stack slot, which is returned in
3300 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
3301 padding required from the initial offset ptr to the stack slot.
3303 IN_REGS is nonzero if the argument will be passed in registers. It will
3304 never be set if REG_PARM_STACK_SPACE is not defined.
3306 FNDECL is the function in which the argument was defined.
3308 There are two types of rounding that are done. The first, controlled by
3309 FUNCTION_ARG_BOUNDARY, forces the offset from the start of the argument
3310 list to be aligned to the specific boundary (in bits). This rounding
3311 affects the initial and starting offsets, but not the argument size.
3313 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
3314 optionally rounds the size of the parm to PARM_BOUNDARY. The
3315 initial offset is not affected by this rounding, while the size always
3316 is and the starting offset may be. */
3318 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
3319 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
3320 callers pass in the total size of args so far as
3321 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
3324 locate_and_pad_parm (enum machine_mode passed_mode, tree type, int in_regs,
3325 int partial, tree fndecl ATTRIBUTE_UNUSED,
3326 struct args_size *initial_offset_ptr,
3327 struct locate_and_pad_arg_data *locate)
3330 enum direction where_pad;
3331 unsigned int boundary;
3332 int reg_parm_stack_space = 0;
3333 int part_size_in_regs;
3335 #ifdef REG_PARM_STACK_SPACE
3336 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
3338 /* If we have found a stack parm before we reach the end of the
3339 area reserved for registers, skip that area. */
3342 if (reg_parm_stack_space > 0)
3344 if (initial_offset_ptr->var)
3346 initial_offset_ptr->var
3347 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
3348 ssize_int (reg_parm_stack_space));
3349 initial_offset_ptr->constant = 0;
3351 else if (initial_offset_ptr->constant < reg_parm_stack_space)
3352 initial_offset_ptr->constant = reg_parm_stack_space;
3355 #endif /* REG_PARM_STACK_SPACE */
3357 part_size_in_regs = (reg_parm_stack_space == 0 ? partial : 0);
3360 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
3361 where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
3362 boundary = FUNCTION_ARG_BOUNDARY (passed_mode, type);
3363 locate->where_pad = where_pad;
3365 /* Alignment can't exceed MAX_SUPPORTED_STACK_ALIGNMENT. */
3366 if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
3367 boundary = MAX_SUPPORTED_STACK_ALIGNMENT;
3369 locate->boundary = boundary;
3371 if (SUPPORTS_STACK_ALIGNMENT)
3373 /* stack_alignment_estimated can't change after stack has been
3375 if (crtl->stack_alignment_estimated < boundary)
3377 if (!crtl->stack_realign_processed)
3378 crtl->stack_alignment_estimated = boundary;
3381 /* If stack is realigned and stack alignment value
3382 hasn't been finalized, it is OK not to increase
3383 stack_alignment_estimated. The bigger alignment
3384 requirement is recorded in stack_alignment_needed
3386 gcc_assert (!crtl->stack_realign_finalized
3387 && crtl->stack_realign_needed);
3392 /* Remember if the outgoing parameter requires extra alignment on the
3393 calling function side. */
3394 if (crtl->stack_alignment_needed < boundary)
3395 crtl->stack_alignment_needed = boundary;
3396 if (crtl->max_used_stack_slot_alignment < crtl->stack_alignment_needed)
3397 crtl->max_used_stack_slot_alignment = crtl->stack_alignment_needed;
3398 if (crtl->preferred_stack_boundary < boundary)
3399 crtl->preferred_stack_boundary = boundary;
3401 #ifdef ARGS_GROW_DOWNWARD
3402 locate->slot_offset.constant = -initial_offset_ptr->constant;
3403 if (initial_offset_ptr->var)
3404 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
3405 initial_offset_ptr->var);
3409 if (where_pad != none
3410 && (!host_integerp (sizetree, 1)
3411 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
3412 s2 = round_up (s2, PARM_BOUNDARY / BITS_PER_UNIT);
3413 SUB_PARM_SIZE (locate->slot_offset, s2);
3416 locate->slot_offset.constant += part_size_in_regs;
3419 #ifdef REG_PARM_STACK_SPACE
3420 || REG_PARM_STACK_SPACE (fndecl) > 0
3423 pad_to_arg_alignment (&locate->slot_offset, boundary,
3424 &locate->alignment_pad);
3426 locate->size.constant = (-initial_offset_ptr->constant
3427 - locate->slot_offset.constant);
3428 if (initial_offset_ptr->var)
3429 locate->size.var = size_binop (MINUS_EXPR,
3430 size_binop (MINUS_EXPR,
3432 initial_offset_ptr->var),
3433 locate->slot_offset.var);
3435 /* Pad_below needs the pre-rounded size to know how much to pad
3437 locate->offset = locate->slot_offset;
3438 if (where_pad == downward)
3439 pad_below (&locate->offset, passed_mode, sizetree);
3441 #else /* !ARGS_GROW_DOWNWARD */
3443 #ifdef REG_PARM_STACK_SPACE
3444 || REG_PARM_STACK_SPACE (fndecl) > 0
3447 pad_to_arg_alignment (initial_offset_ptr, boundary,
3448 &locate->alignment_pad);
3449 locate->slot_offset = *initial_offset_ptr;
3451 #ifdef PUSH_ROUNDING
3452 if (passed_mode != BLKmode)
3453 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
3456 /* Pad_below needs the pre-rounded size to know how much to pad below
3457 so this must be done before rounding up. */
3458 locate->offset = locate->slot_offset;
3459 if (where_pad == downward)
3460 pad_below (&locate->offset, passed_mode, sizetree);
3462 if (where_pad != none
3463 && (!host_integerp (sizetree, 1)
3464 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
3465 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3467 ADD_PARM_SIZE (locate->size, sizetree);
3469 locate->size.constant -= part_size_in_regs;
3470 #endif /* ARGS_GROW_DOWNWARD */
3473 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
3474 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
3477 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
3478 struct args_size *alignment_pad)
3480 tree save_var = NULL_TREE;
3481 HOST_WIDE_INT save_constant = 0;
3482 int boundary_in_bytes = boundary / BITS_PER_UNIT;
3483 HOST_WIDE_INT sp_offset = STACK_POINTER_OFFSET;
3485 #ifdef SPARC_STACK_BOUNDARY_HACK
3486 /* ??? The SPARC port may claim a STACK_BOUNDARY higher than
3487 the real alignment of %sp. However, when it does this, the
3488 alignment of %sp+STACK_POINTER_OFFSET is STACK_BOUNDARY. */
3489 if (SPARC_STACK_BOUNDARY_HACK)
3493 if (boundary > PARM_BOUNDARY)
3495 save_var = offset_ptr->var;
3496 save_constant = offset_ptr->constant;
3499 alignment_pad->var = NULL_TREE;
3500 alignment_pad->constant = 0;
3502 if (boundary > BITS_PER_UNIT)
3504 if (offset_ptr->var)
3506 tree sp_offset_tree = ssize_int (sp_offset);
3507 tree offset = size_binop (PLUS_EXPR,
3508 ARGS_SIZE_TREE (*offset_ptr),
3510 #ifdef ARGS_GROW_DOWNWARD
3511 tree rounded = round_down (offset, boundary / BITS_PER_UNIT);
3513 tree rounded = round_up (offset, boundary / BITS_PER_UNIT);
3516 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
3517 /* ARGS_SIZE_TREE includes constant term. */
3518 offset_ptr->constant = 0;
3519 if (boundary > PARM_BOUNDARY)
3520 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
3525 offset_ptr->constant = -sp_offset +
3526 #ifdef ARGS_GROW_DOWNWARD
3527 FLOOR_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
3529 CEIL_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
3531 if (boundary > PARM_BOUNDARY)
3532 alignment_pad->constant = offset_ptr->constant - save_constant;
3538 pad_below (struct args_size *offset_ptr, enum machine_mode passed_mode, tree sizetree)
3540 if (passed_mode != BLKmode)
3542 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
3543 offset_ptr->constant
3544 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
3545 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
3546 - GET_MODE_SIZE (passed_mode));
3550 if (TREE_CODE (sizetree) != INTEGER_CST
3551 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
3553 /* Round the size up to multiple of PARM_BOUNDARY bits. */
3554 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3556 ADD_PARM_SIZE (*offset_ptr, s2);
3557 SUB_PARM_SIZE (*offset_ptr, sizetree);
3563 /* True if register REGNO was alive at a place where `setjmp' was
3564 called and was set more than once or is an argument. Such regs may
3565 be clobbered by `longjmp'. */
3568 regno_clobbered_at_setjmp (bitmap setjmp_crosses, int regno)
3570 /* There appear to be cases where some local vars never reach the
3571 backend but have bogus regnos. */
3572 if (regno >= max_reg_num ())
3575 return ((REG_N_SETS (regno) > 1
3576 || REGNO_REG_SET_P (df_get_live_out (ENTRY_BLOCK_PTR), regno))
3577 && REGNO_REG_SET_P (setjmp_crosses, regno));
3580 /* Walk the tree of blocks describing the binding levels within a
3581 function and warn about variables the might be killed by setjmp or
3582 vfork. This is done after calling flow_analysis before register
3583 allocation since that will clobber the pseudo-regs to hard
3587 setjmp_vars_warning (bitmap setjmp_crosses, tree block)
3591 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
3593 if (TREE_CODE (decl) == VAR_DECL
3594 && DECL_RTL_SET_P (decl)
3595 && REG_P (DECL_RTL (decl))
3596 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
3597 warning (OPT_Wclobbered, "variable %q+D might be clobbered by"
3598 " %<longjmp%> or %<vfork%>", decl);
3601 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = BLOCK_CHAIN (sub))
3602 setjmp_vars_warning (setjmp_crosses, sub);
3605 /* Do the appropriate part of setjmp_vars_warning
3606 but for arguments instead of local variables. */
3609 setjmp_args_warning (bitmap setjmp_crosses)
3612 for (decl = DECL_ARGUMENTS (current_function_decl);
3613 decl; decl = TREE_CHAIN (decl))
3614 if (DECL_RTL (decl) != 0
3615 && REG_P (DECL_RTL (decl))
3616 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
3617 warning (OPT_Wclobbered,
3618 "argument %q+D might be clobbered by %<longjmp%> or %<vfork%>",
3622 /* Generate warning messages for variables live across setjmp. */
3625 generate_setjmp_warnings (void)
3627 bitmap setjmp_crosses = regstat_get_setjmp_crosses ();
3629 if (n_basic_blocks == NUM_FIXED_BLOCKS
3630 || bitmap_empty_p (setjmp_crosses))
3633 setjmp_vars_warning (setjmp_crosses, DECL_INITIAL (current_function_decl));
3634 setjmp_args_warning (setjmp_crosses);
3638 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
3639 and create duplicate blocks. */
3640 /* ??? Need an option to either create block fragments or to create
3641 abstract origin duplicates of a source block. It really depends
3642 on what optimization has been performed. */
3645 reorder_blocks (void)
3647 tree block = DECL_INITIAL (current_function_decl);
3648 VEC(tree,heap) *block_stack;
3650 if (block == NULL_TREE)
3653 block_stack = VEC_alloc (tree, heap, 10);
3655 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
3656 clear_block_marks (block);
3658 /* Prune the old trees away, so that they don't get in the way. */
3659 BLOCK_SUBBLOCKS (block) = NULL_TREE;
3660 BLOCK_CHAIN (block) = NULL_TREE;
3662 /* Recreate the block tree from the note nesting. */
3663 reorder_blocks_1 (get_insns (), block, &block_stack);
3664 BLOCK_SUBBLOCKS (block) = blocks_nreverse (BLOCK_SUBBLOCKS (block));
3666 VEC_free (tree, heap, block_stack);
3669 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
3672 clear_block_marks (tree block)
3676 TREE_ASM_WRITTEN (block) = 0;
3677 clear_block_marks (BLOCK_SUBBLOCKS (block));
3678 block = BLOCK_CHAIN (block);
3683 reorder_blocks_1 (rtx insns, tree current_block, VEC(tree,heap) **p_block_stack)
3687 for (insn = insns; insn; insn = NEXT_INSN (insn))
3691 if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_BEG)
3693 tree block = NOTE_BLOCK (insn);
3696 origin = (BLOCK_FRAGMENT_ORIGIN (block)
3697 ? BLOCK_FRAGMENT_ORIGIN (block)
3700 /* If we have seen this block before, that means it now
3701 spans multiple address regions. Create a new fragment. */
3702 if (TREE_ASM_WRITTEN (block))
3704 tree new_block = copy_node (block);
3706 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
3707 BLOCK_FRAGMENT_CHAIN (new_block)
3708 = BLOCK_FRAGMENT_CHAIN (origin);
3709 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
3711 NOTE_BLOCK (insn) = new_block;
3715 BLOCK_SUBBLOCKS (block) = 0;
3716 TREE_ASM_WRITTEN (block) = 1;
3717 /* When there's only one block for the entire function,
3718 current_block == block and we mustn't do this, it
3719 will cause infinite recursion. */
3720 if (block != current_block)
3722 if (block != origin)
3723 gcc_assert (BLOCK_SUPERCONTEXT (origin) == current_block);
3725 BLOCK_SUPERCONTEXT (block) = current_block;
3726 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
3727 BLOCK_SUBBLOCKS (current_block) = block;
3728 current_block = origin;
3730 VEC_safe_push (tree, heap, *p_block_stack, block);
3732 else if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_END)
3734 NOTE_BLOCK (insn) = VEC_pop (tree, *p_block_stack);
3735 BLOCK_SUBBLOCKS (current_block)
3736 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block));
3737 current_block = BLOCK_SUPERCONTEXT (current_block);
3743 /* Reverse the order of elements in the chain T of blocks,
3744 and return the new head of the chain (old last element). */
3747 blocks_nreverse (tree t)
3749 tree prev = 0, decl, next;
3750 for (decl = t; decl; decl = next)
3752 next = BLOCK_CHAIN (decl);
3753 BLOCK_CHAIN (decl) = prev;
3759 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
3760 non-NULL, list them all into VECTOR, in a depth-first preorder
3761 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
3765 all_blocks (tree block, tree *vector)
3771 TREE_ASM_WRITTEN (block) = 0;
3773 /* Record this block. */
3775 vector[n_blocks] = block;
3779 /* Record the subblocks, and their subblocks... */
3780 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
3781 vector ? vector + n_blocks : 0);
3782 block = BLOCK_CHAIN (block);
3788 /* Return a vector containing all the blocks rooted at BLOCK. The
3789 number of elements in the vector is stored in N_BLOCKS_P. The
3790 vector is dynamically allocated; it is the caller's responsibility
3791 to call `free' on the pointer returned. */
3794 get_block_vector (tree block, int *n_blocks_p)
3798 *n_blocks_p = all_blocks (block, NULL);
3799 block_vector = XNEWVEC (tree, *n_blocks_p);
3800 all_blocks (block, block_vector);
3802 return block_vector;
3805 static GTY(()) int next_block_index = 2;
3807 /* Set BLOCK_NUMBER for all the blocks in FN. */
3810 number_blocks (tree fn)
3816 /* For SDB and XCOFF debugging output, we start numbering the blocks
3817 from 1 within each function, rather than keeping a running
3819 #if defined (SDB_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
3820 if (write_symbols == SDB_DEBUG || write_symbols == XCOFF_DEBUG)
3821 next_block_index = 1;
3824 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
3826 /* The top-level BLOCK isn't numbered at all. */
3827 for (i = 1; i < n_blocks; ++i)
3828 /* We number the blocks from two. */
3829 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
3831 free (block_vector);
3836 /* If VAR is present in a subblock of BLOCK, return the subblock. */
3839 debug_find_var_in_block_tree (tree var, tree block)
3843 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
3847 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
3849 tree ret = debug_find_var_in_block_tree (var, t);
3857 /* Keep track of whether we're in a dummy function context. If we are,
3858 we don't want to invoke the set_current_function hook, because we'll
3859 get into trouble if the hook calls target_reinit () recursively or
3860 when the initial initialization is not yet complete. */
3862 static bool in_dummy_function;
3864 /* Invoke the target hook when setting cfun. Update the optimization options
3865 if the function uses different options than the default. */
3868 invoke_set_current_function_hook (tree fndecl)
3870 if (!in_dummy_function)
3872 tree opts = ((fndecl)
3873 ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (fndecl)
3874 : optimization_default_node);
3877 opts = optimization_default_node;
3879 /* Change optimization options if needed. */
3880 if (optimization_current_node != opts)
3882 optimization_current_node = opts;
3883 cl_optimization_restore (TREE_OPTIMIZATION (opts));
3886 targetm.set_current_function (fndecl);
3890 /* cfun should never be set directly; use this function. */
3893 set_cfun (struct function *new_cfun)
3895 if (cfun != new_cfun)
3898 invoke_set_current_function_hook (new_cfun ? new_cfun->decl : NULL_TREE);
3902 /* Keep track of the cfun stack. */
3904 typedef struct function *function_p;
3906 DEF_VEC_P(function_p);
3907 DEF_VEC_ALLOC_P(function_p,heap);
3909 /* Initialized with NOGC, making this poisonous to the garbage collector. */
3911 static VEC(function_p,heap) *cfun_stack;
3913 /* Push the current cfun onto the stack, and set cfun to new_cfun. */
3916 push_cfun (struct function *new_cfun)
3918 VEC_safe_push (function_p, heap, cfun_stack, cfun);
3919 set_cfun (new_cfun);
3922 /* Pop cfun from the stack. */
3927 struct function *new_cfun = VEC_pop (function_p, cfun_stack);
3928 set_cfun (new_cfun);
3931 /* Return value of funcdef and increase it. */
3933 get_next_funcdef_no (void)
3935 return funcdef_no++;
3938 /* Allocate a function structure for FNDECL and set its contents
3939 to the defaults. Set cfun to the newly-allocated object.
3940 Some of the helper functions invoked during initialization assume
3941 that cfun has already been set. Therefore, assign the new object
3942 directly into cfun and invoke the back end hook explicitly at the
3943 very end, rather than initializing a temporary and calling set_cfun
3946 ABSTRACT_P is true if this is a function that will never be seen by
3947 the middle-end. Such functions are front-end concepts (like C++
3948 function templates) that do not correspond directly to functions
3949 placed in object files. */
3952 allocate_struct_function (tree fndecl, bool abstract_p)
3955 tree fntype = fndecl ? TREE_TYPE (fndecl) : NULL_TREE;
3957 cfun = GGC_CNEW (struct function);
3959 cfun->function_frequency = FUNCTION_FREQUENCY_NORMAL;
3961 init_eh_for_function ();
3963 if (init_machine_status)
3964 cfun->machine = (*init_machine_status) ();
3966 #ifdef OVERRIDE_ABI_FORMAT
3967 OVERRIDE_ABI_FORMAT (fndecl);
3970 if (fndecl != NULL_TREE)
3972 DECL_STRUCT_FUNCTION (fndecl) = cfun;
3973 cfun->decl = fndecl;
3974 current_function_funcdef_no = get_next_funcdef_no ();
3976 result = DECL_RESULT (fndecl);
3977 if (!abstract_p && aggregate_value_p (result, fndecl))
3979 #ifdef PCC_STATIC_STRUCT_RETURN
3980 cfun->returns_pcc_struct = 1;
3982 cfun->returns_struct = 1;
3987 && TYPE_ARG_TYPES (fntype) != 0
3988 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
3989 != void_type_node));
3991 /* Assume all registers in stdarg functions need to be saved. */
3992 cfun->va_list_gpr_size = VA_LIST_MAX_GPR_SIZE;
3993 cfun->va_list_fpr_size = VA_LIST_MAX_FPR_SIZE;
3996 invoke_set_current_function_hook (fndecl);
3999 /* This is like allocate_struct_function, but pushes a new cfun for FNDECL
4000 instead of just setting it. */
4003 push_struct_function (tree fndecl)
4005 VEC_safe_push (function_p, heap, cfun_stack, cfun);
4006 allocate_struct_function (fndecl, false);
4009 /* Reset cfun, and other non-struct-function variables to defaults as
4010 appropriate for emitting rtl at the start of a function. */
4013 prepare_function_start (void)
4015 gcc_assert (!crtl->emit.x_last_insn);
4017 init_varasm_status ();
4019 default_rtl_profile ();
4021 cse_not_expected = ! optimize;
4023 /* Caller save not needed yet. */
4024 caller_save_needed = 0;
4026 /* We haven't done register allocation yet. */
4029 /* Indicate that we have not instantiated virtual registers yet. */
4030 virtuals_instantiated = 0;
4032 /* Indicate that we want CONCATs now. */
4033 generating_concat_p = 1;
4035 /* Indicate we have no need of a frame pointer yet. */
4036 frame_pointer_needed = 0;
4039 /* Initialize the rtl expansion mechanism so that we can do simple things
4040 like generate sequences. This is used to provide a context during global
4041 initialization of some passes. You must call expand_dummy_function_end
4042 to exit this context. */
4045 init_dummy_function_start (void)
4047 gcc_assert (!in_dummy_function);
4048 in_dummy_function = true;
4049 push_struct_function (NULL_TREE);
4050 prepare_function_start ();
4053 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
4054 and initialize static variables for generating RTL for the statements
4058 init_function_start (tree subr)
4060 if (subr && DECL_STRUCT_FUNCTION (subr))
4061 set_cfun (DECL_STRUCT_FUNCTION (subr));
4063 allocate_struct_function (subr, false);
4064 prepare_function_start ();
4066 /* Warn if this value is an aggregate type,
4067 regardless of which calling convention we are using for it. */
4068 if (AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
4069 warning (OPT_Waggregate_return, "function returns an aggregate");
4072 /* Make sure all values used by the optimization passes have sane
4075 init_function_for_compilation (void)
4079 /* No prologue/epilogue insns yet. Make sure that these vectors are
4081 gcc_assert (VEC_length (int, prologue) == 0);
4082 gcc_assert (VEC_length (int, epilogue) == 0);
4083 gcc_assert (VEC_length (int, sibcall_epilogue) == 0);
4087 struct rtl_opt_pass pass_init_function =
4093 init_function_for_compilation, /* execute */
4096 0, /* static_pass_number */
4098 0, /* properties_required */
4099 0, /* properties_provided */
4100 0, /* properties_destroyed */
4101 0, /* todo_flags_start */
4102 0 /* todo_flags_finish */
4108 expand_main_function (void)
4110 #if (defined(INVOKE__main) \
4111 || (!defined(HAS_INIT_SECTION) \
4112 && !defined(INIT_SECTION_ASM_OP) \
4113 && !defined(INIT_ARRAY_SECTION_ASM_OP)))
4114 emit_library_call (init_one_libfunc (NAME__MAIN), LCT_NORMAL, VOIDmode, 0);
4118 /* Expand code to initialize the stack_protect_guard. This is invoked at
4119 the beginning of a function to be protected. */
4121 #ifndef HAVE_stack_protect_set
4122 # define HAVE_stack_protect_set 0
4123 # define gen_stack_protect_set(x,y) (gcc_unreachable (), NULL_RTX)
4127 stack_protect_prologue (void)
4129 tree guard_decl = targetm.stack_protect_guard ();
4132 /* Avoid expand_expr here, because we don't want guard_decl pulled
4133 into registers unless absolutely necessary. And we know that
4134 crtl->stack_protect_guard is a local stack slot, so this skips
4136 x = validize_mem (DECL_RTL (crtl->stack_protect_guard));
4137 y = validize_mem (DECL_RTL (guard_decl));
4139 /* Allow the target to copy from Y to X without leaking Y into a
4141 if (HAVE_stack_protect_set)
4143 rtx insn = gen_stack_protect_set (x, y);
4151 /* Otherwise do a straight move. */
4152 emit_move_insn (x, y);
4155 /* Expand code to verify the stack_protect_guard. This is invoked at
4156 the end of a function to be protected. */
4158 #ifndef HAVE_stack_protect_test
4159 # define HAVE_stack_protect_test 0
4160 # define gen_stack_protect_test(x, y, z) (gcc_unreachable (), NULL_RTX)
4164 stack_protect_epilogue (void)
4166 tree guard_decl = targetm.stack_protect_guard ();
4167 rtx label = gen_label_rtx ();
4170 /* Avoid expand_expr here, because we don't want guard_decl pulled
4171 into registers unless absolutely necessary. And we know that
4172 crtl->stack_protect_guard is a local stack slot, so this skips
4174 x = validize_mem (DECL_RTL (crtl->stack_protect_guard));
4175 y = validize_mem (DECL_RTL (guard_decl));
4177 /* Allow the target to compare Y with X without leaking either into
4179 switch (HAVE_stack_protect_test != 0)
4182 tmp = gen_stack_protect_test (x, y, label);
4191 emit_cmp_and_jump_insns (x, y, EQ, NULL_RTX, ptr_mode, 1, label);
4195 /* The noreturn predictor has been moved to the tree level. The rtl-level
4196 predictors estimate this branch about 20%, which isn't enough to get
4197 things moved out of line. Since this is the only extant case of adding
4198 a noreturn function at the rtl level, it doesn't seem worth doing ought
4199 except adding the prediction by hand. */
4200 tmp = get_last_insn ();
4202 predict_insn_def (tmp, PRED_NORETURN, TAKEN);
4204 expand_expr_stmt (targetm.stack_protect_fail ());
4208 /* Start the RTL for a new function, and set variables used for
4210 SUBR is the FUNCTION_DECL node.
4211 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
4212 the function's parameters, which must be run at any return statement. */
4215 expand_function_start (tree subr)
4217 /* Make sure volatile mem refs aren't considered
4218 valid operands of arithmetic insns. */
4219 init_recog_no_volatile ();
4223 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
4226 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
4228 /* Make the label for return statements to jump to. Do not special
4229 case machines with special return instructions -- they will be
4230 handled later during jump, ifcvt, or epilogue creation. */
4231 return_label = gen_label_rtx ();
4233 /* Initialize rtx used to return the value. */
4234 /* Do this before assign_parms so that we copy the struct value address
4235 before any library calls that assign parms might generate. */
4237 /* Decide whether to return the value in memory or in a register. */
4238 if (aggregate_value_p (DECL_RESULT (subr), subr))
4240 /* Returning something that won't go in a register. */
4241 rtx value_address = 0;
4243 #ifdef PCC_STATIC_STRUCT_RETURN
4244 if (cfun->returns_pcc_struct)
4246 int size = int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr)));
4247 value_address = assemble_static_space (size);
4252 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 2);
4253 /* Expect to be passed the address of a place to store the value.
4254 If it is passed as an argument, assign_parms will take care of
4258 value_address = gen_reg_rtx (Pmode);
4259 emit_move_insn (value_address, sv);
4264 rtx x = value_address;
4265 if (!DECL_BY_REFERENCE (DECL_RESULT (subr)))
4267 x = gen_rtx_MEM (DECL_MODE (DECL_RESULT (subr)), x);
4268 set_mem_attributes (x, DECL_RESULT (subr), 1);
4270 SET_DECL_RTL (DECL_RESULT (subr), x);
4273 else if (DECL_MODE (DECL_RESULT (subr)) == VOIDmode)
4274 /* If return mode is void, this decl rtl should not be used. */
4275 SET_DECL_RTL (DECL_RESULT (subr), NULL_RTX);
4278 /* Compute the return values into a pseudo reg, which we will copy
4279 into the true return register after the cleanups are done. */
4280 tree return_type = TREE_TYPE (DECL_RESULT (subr));
4281 if (TYPE_MODE (return_type) != BLKmode
4282 && targetm.calls.return_in_msb (return_type))
4283 /* expand_function_end will insert the appropriate padding in
4284 this case. Use the return value's natural (unpadded) mode
4285 within the function proper. */
4286 SET_DECL_RTL (DECL_RESULT (subr),
4287 gen_reg_rtx (TYPE_MODE (return_type)));
4290 /* In order to figure out what mode to use for the pseudo, we
4291 figure out what the mode of the eventual return register will
4292 actually be, and use that. */
4293 rtx hard_reg = hard_function_value (return_type, subr, 0, 1);
4295 /* Structures that are returned in registers are not
4296 aggregate_value_p, so we may see a PARALLEL or a REG. */
4297 if (REG_P (hard_reg))
4298 SET_DECL_RTL (DECL_RESULT (subr),
4299 gen_reg_rtx (GET_MODE (hard_reg)));
4302 gcc_assert (GET_CODE (hard_reg) == PARALLEL);
4303 SET_DECL_RTL (DECL_RESULT (subr), gen_group_rtx (hard_reg));
4307 /* Set DECL_REGISTER flag so that expand_function_end will copy the
4308 result to the real return register(s). */
4309 DECL_REGISTER (DECL_RESULT (subr)) = 1;
4312 /* Initialize rtx for parameters and local variables.
4313 In some cases this requires emitting insns. */
4314 assign_parms (subr);
4316 /* If function gets a static chain arg, store it. */
4317 if (cfun->static_chain_decl)
4319 tree parm = cfun->static_chain_decl;
4320 rtx local = gen_reg_rtx (Pmode);
4322 set_decl_incoming_rtl (parm, static_chain_incoming_rtx, false);
4323 SET_DECL_RTL (parm, local);
4324 mark_reg_pointer (local, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
4326 emit_move_insn (local, static_chain_incoming_rtx);
4329 /* If the function receives a non-local goto, then store the
4330 bits we need to restore the frame pointer. */
4331 if (cfun->nonlocal_goto_save_area)
4336 /* ??? We need to do this save early. Unfortunately here is
4337 before the frame variable gets declared. Help out... */
4338 tree var = TREE_OPERAND (cfun->nonlocal_goto_save_area, 0);
4339 if (!DECL_RTL_SET_P (var))
4342 t_save = build4 (ARRAY_REF, ptr_type_node,
4343 cfun->nonlocal_goto_save_area,
4344 integer_zero_node, NULL_TREE, NULL_TREE);
4345 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
4346 r_save = convert_memory_address (Pmode, r_save);
4348 emit_move_insn (r_save, targetm.builtin_setjmp_frame_value ());
4349 update_nonlocal_goto_save_area ();
4352 /* The following was moved from init_function_start.
4353 The move is supposed to make sdb output more accurate. */
4354 /* Indicate the beginning of the function body,
4355 as opposed to parm setup. */
4356 emit_note (NOTE_INSN_FUNCTION_BEG);
4358 gcc_assert (NOTE_P (get_last_insn ()));
4360 parm_birth_insn = get_last_insn ();
4365 PROFILE_HOOK (current_function_funcdef_no);
4369 /* After the display initializations is where the stack checking
4371 if(flag_stack_check)
4372 stack_check_probe_note = emit_note (NOTE_INSN_DELETED);
4374 /* Make sure there is a line number after the function entry setup code. */
4375 force_next_line_note ();
4378 /* Undo the effects of init_dummy_function_start. */
4380 expand_dummy_function_end (void)
4382 gcc_assert (in_dummy_function);
4384 /* End any sequences that failed to be closed due to syntax errors. */
4385 while (in_sequence_p ())
4388 /* Outside function body, can't compute type's actual size
4389 until next function's body starts. */
4391 free_after_parsing (cfun);
4392 free_after_compilation (cfun);
4394 in_dummy_function = false;
4397 /* Call DOIT for each hard register used as a return value from
4398 the current function. */
4401 diddle_return_value (void (*doit) (rtx, void *), void *arg)
4403 rtx outgoing = crtl->return_rtx;
4408 if (REG_P (outgoing))
4409 (*doit) (outgoing, arg);
4410 else if (GET_CODE (outgoing) == PARALLEL)
4414 for (i = 0; i < XVECLEN (outgoing, 0); i++)
4416 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
4418 if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
4425 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
4431 clobber_return_register (void)
4433 diddle_return_value (do_clobber_return_reg, NULL);
4435 /* In case we do use pseudo to return value, clobber it too. */
4436 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
4438 tree decl_result = DECL_RESULT (current_function_decl);
4439 rtx decl_rtl = DECL_RTL (decl_result);
4440 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
4442 do_clobber_return_reg (decl_rtl, NULL);
4448 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
4454 use_return_register (void)
4456 diddle_return_value (do_use_return_reg, NULL);
4459 /* Possibly warn about unused parameters. */
4461 do_warn_unused_parameter (tree fn)
4465 for (decl = DECL_ARGUMENTS (fn);
4466 decl; decl = TREE_CHAIN (decl))
4467 if (!TREE_USED (decl) && TREE_CODE (decl) == PARM_DECL
4468 && DECL_NAME (decl) && !DECL_ARTIFICIAL (decl)
4469 && !TREE_NO_WARNING (decl))
4470 warning (OPT_Wunused_parameter, "unused parameter %q+D", decl);
4473 static GTY(()) rtx initial_trampoline;
4475 /* Generate RTL for the end of the current function. */
4478 expand_function_end (void)
4482 /* If arg_pointer_save_area was referenced only from a nested
4483 function, we will not have initialized it yet. Do that now. */
4484 if (arg_pointer_save_area && ! crtl->arg_pointer_save_area_init)
4485 get_arg_pointer_save_area ();
4487 /* If we are doing generic stack checking and this function makes calls,
4488 do a stack probe at the start of the function to ensure we have enough
4489 space for another stack frame. */
4490 if (flag_stack_check == GENERIC_STACK_CHECK)
4494 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
4498 probe_stack_range (STACK_OLD_CHECK_PROTECT,
4499 GEN_INT (STACK_CHECK_MAX_FRAME_SIZE));
4502 emit_insn_before (seq, stack_check_probe_note);
4507 /* End any sequences that failed to be closed due to syntax errors. */
4508 while (in_sequence_p ())
4511 clear_pending_stack_adjust ();
4512 do_pending_stack_adjust ();
4514 /* Output a linenumber for the end of the function.
4515 SDB depends on this. */
4516 force_next_line_note ();
4517 set_curr_insn_source_location (input_location);
4519 /* Before the return label (if any), clobber the return
4520 registers so that they are not propagated live to the rest of
4521 the function. This can only happen with functions that drop
4522 through; if there had been a return statement, there would
4523 have either been a return rtx, or a jump to the return label.
4525 We delay actual code generation after the current_function_value_rtx
4527 clobber_after = get_last_insn ();
4529 /* Output the label for the actual return from the function. */
4530 emit_label (return_label);
4532 if (USING_SJLJ_EXCEPTIONS)
4534 /* Let except.c know where it should emit the call to unregister
4535 the function context for sjlj exceptions. */
4536 if (flag_exceptions)
4537 sjlj_emit_function_exit_after (get_last_insn ());
4541 /* We want to ensure that instructions that may trap are not
4542 moved into the epilogue by scheduling, because we don't
4543 always emit unwind information for the epilogue. */
4544 if (flag_non_call_exceptions)
4545 emit_insn (gen_blockage ());
4548 /* If this is an implementation of throw, do what's necessary to
4549 communicate between __builtin_eh_return and the epilogue. */
4550 expand_eh_return ();
4552 /* If scalar return value was computed in a pseudo-reg, or was a named
4553 return value that got dumped to the stack, copy that to the hard
4555 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
4557 tree decl_result = DECL_RESULT (current_function_decl);
4558 rtx decl_rtl = DECL_RTL (decl_result);
4560 if (REG_P (decl_rtl)
4561 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
4562 : DECL_REGISTER (decl_result))
4564 rtx real_decl_rtl = crtl->return_rtx;
4566 /* This should be set in assign_parms. */
4567 gcc_assert (REG_FUNCTION_VALUE_P (real_decl_rtl));
4569 /* If this is a BLKmode structure being returned in registers,
4570 then use the mode computed in expand_return. Note that if
4571 decl_rtl is memory, then its mode may have been changed,
4572 but that crtl->return_rtx has not. */
4573 if (GET_MODE (real_decl_rtl) == BLKmode)
4574 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
4576 /* If a non-BLKmode return value should be padded at the least
4577 significant end of the register, shift it left by the appropriate
4578 amount. BLKmode results are handled using the group load/store
4580 if (TYPE_MODE (TREE_TYPE (decl_result)) != BLKmode
4581 && targetm.calls.return_in_msb (TREE_TYPE (decl_result)))
4583 emit_move_insn (gen_rtx_REG (GET_MODE (decl_rtl),
4584 REGNO (real_decl_rtl)),
4586 shift_return_value (GET_MODE (decl_rtl), true, real_decl_rtl);
4588 /* If a named return value dumped decl_return to memory, then
4589 we may need to re-do the PROMOTE_MODE signed/unsigned
4591 else if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
4593 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
4595 if (targetm.calls.promote_function_return (TREE_TYPE (current_function_decl)))
4596 promote_mode (TREE_TYPE (decl_result), GET_MODE (decl_rtl),
4599 convert_move (real_decl_rtl, decl_rtl, unsignedp);
4601 else if (GET_CODE (real_decl_rtl) == PARALLEL)
4603 /* If expand_function_start has created a PARALLEL for decl_rtl,
4604 move the result to the real return registers. Otherwise, do
4605 a group load from decl_rtl for a named return. */
4606 if (GET_CODE (decl_rtl) == PARALLEL)
4607 emit_group_move (real_decl_rtl, decl_rtl);
4609 emit_group_load (real_decl_rtl, decl_rtl,
4610 TREE_TYPE (decl_result),
4611 int_size_in_bytes (TREE_TYPE (decl_result)));
4613 /* In the case of complex integer modes smaller than a word, we'll
4614 need to generate some non-trivial bitfield insertions. Do that
4615 on a pseudo and not the hard register. */
4616 else if (GET_CODE (decl_rtl) == CONCAT
4617 && GET_MODE_CLASS (GET_MODE (decl_rtl)) == MODE_COMPLEX_INT
4618 && GET_MODE_BITSIZE (GET_MODE (decl_rtl)) <= BITS_PER_WORD)
4620 int old_generating_concat_p;
4623 old_generating_concat_p = generating_concat_p;
4624 generating_concat_p = 0;
4625 tmp = gen_reg_rtx (GET_MODE (decl_rtl));
4626 generating_concat_p = old_generating_concat_p;
4628 emit_move_insn (tmp, decl_rtl);
4629 emit_move_insn (real_decl_rtl, tmp);
4632 emit_move_insn (real_decl_rtl, decl_rtl);
4636 /* If returning a structure, arrange to return the address of the value
4637 in a place where debuggers expect to find it.
4639 If returning a structure PCC style,
4640 the caller also depends on this value.
4641 And cfun->returns_pcc_struct is not necessarily set. */
4642 if (cfun->returns_struct
4643 || cfun->returns_pcc_struct)
4645 rtx value_address = DECL_RTL (DECL_RESULT (current_function_decl));
4646 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
4649 if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
4650 type = TREE_TYPE (type);
4652 value_address = XEXP (value_address, 0);
4654 outgoing = targetm.calls.function_value (build_pointer_type (type),
4655 current_function_decl, true);
4657 /* Mark this as a function return value so integrate will delete the
4658 assignment and USE below when inlining this function. */
4659 REG_FUNCTION_VALUE_P (outgoing) = 1;
4661 /* The address may be ptr_mode and OUTGOING may be Pmode. */
4662 value_address = convert_memory_address (GET_MODE (outgoing),
4665 emit_move_insn (outgoing, value_address);
4667 /* Show return register used to hold result (in this case the address
4669 crtl->return_rtx = outgoing;
4672 /* Emit the actual code to clobber return register. */
4677 clobber_return_register ();
4678 expand_naked_return ();
4682 emit_insn_after (seq, clobber_after);
4685 /* Output the label for the naked return from the function. */
4686 emit_label (naked_return_label);
4688 /* @@@ This is a kludge. We want to ensure that instructions that
4689 may trap are not moved into the epilogue by scheduling, because
4690 we don't always emit unwind information for the epilogue. */
4691 if (! USING_SJLJ_EXCEPTIONS && flag_non_call_exceptions)
4692 emit_insn (gen_blockage ());
4694 /* If stack protection is enabled for this function, check the guard. */
4695 if (crtl->stack_protect_guard)
4696 stack_protect_epilogue ();
4698 /* If we had calls to alloca, and this machine needs
4699 an accurate stack pointer to exit the function,
4700 insert some code to save and restore the stack pointer. */
4701 if (! EXIT_IGNORE_STACK
4702 && cfun->calls_alloca)
4706 emit_stack_save (SAVE_FUNCTION, &tem, parm_birth_insn);
4707 emit_stack_restore (SAVE_FUNCTION, tem, NULL_RTX);
4710 /* ??? This should no longer be necessary since stupid is no longer with
4711 us, but there are some parts of the compiler (eg reload_combine, and
4712 sh mach_dep_reorg) that still try and compute their own lifetime info
4713 instead of using the general framework. */
4714 use_return_register ();
4718 get_arg_pointer_save_area (void)
4720 rtx ret = arg_pointer_save_area;
4724 ret = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
4725 arg_pointer_save_area = ret;
4728 if (! crtl->arg_pointer_save_area_init)
4732 /* Save the arg pointer at the beginning of the function. The
4733 generated stack slot may not be a valid memory address, so we
4734 have to check it and fix it if necessary. */
4736 emit_move_insn (validize_mem (ret),
4737 crtl->args.internal_arg_pointer);
4741 push_topmost_sequence ();
4742 emit_insn_after (seq, entry_of_function ());
4743 pop_topmost_sequence ();
4749 /* Extend a vector that records the INSN_UIDs of INSNS
4750 (a list of one or more insns). */
4753 record_insns (rtx insns, VEC(int,heap) **vecp)
4757 for (tmp = insns; tmp != NULL_RTX; tmp = NEXT_INSN (tmp))
4758 VEC_safe_push (int, heap, *vecp, INSN_UID (tmp));
4761 /* Set the locator of the insn chain starting at INSN to LOC. */
4763 set_insn_locators (rtx insn, int loc)
4765 while (insn != NULL_RTX)
4768 INSN_LOCATOR (insn) = loc;
4769 insn = NEXT_INSN (insn);
4773 /* Determine how many INSN_UIDs in VEC are part of INSN. Because we can
4774 be running after reorg, SEQUENCE rtl is possible. */
4777 contains (const_rtx insn, VEC(int,heap) **vec)
4781 if (NONJUMP_INSN_P (insn)
4782 && GET_CODE (PATTERN (insn)) == SEQUENCE)
4785 for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
4786 for (j = VEC_length (int, *vec) - 1; j >= 0; --j)
4787 if (INSN_UID (XVECEXP (PATTERN (insn), 0, i))
4788 == VEC_index (int, *vec, j))
4794 for (j = VEC_length (int, *vec) - 1; j >= 0; --j)
4795 if (INSN_UID (insn) == VEC_index (int, *vec, j))
4802 prologue_epilogue_contains (const_rtx insn)
4804 if (contains (insn, &prologue))
4806 if (contains (insn, &epilogue))
4812 sibcall_epilogue_contains (const_rtx insn)
4814 if (sibcall_epilogue)
4815 return contains (insn, &sibcall_epilogue);
4820 /* Insert gen_return at the end of block BB. This also means updating
4821 block_for_insn appropriately. */
4824 emit_return_into_block (basic_block bb)
4826 emit_jump_insn_after (gen_return (), BB_END (bb));
4828 #endif /* HAVE_return */
4830 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
4831 this into place with notes indicating where the prologue ends and where
4832 the epilogue begins. Update the basic block information when possible. */
4835 thread_prologue_and_epilogue_insns (void)
4839 #if defined (HAVE_sibcall_epilogue) || defined (HAVE_epilogue) || defined (HAVE_return) || defined (HAVE_prologue)
4842 #if defined (HAVE_epilogue) || defined(HAVE_return)
4843 rtx epilogue_end = NULL_RTX;
4847 rtl_profile_for_bb (ENTRY_BLOCK_PTR);
4848 #ifdef HAVE_prologue
4852 seq = gen_prologue ();
4855 /* Insert an explicit USE for the frame pointer
4856 if the profiling is on and the frame pointer is required. */
4857 if (crtl->profile && frame_pointer_needed)
4858 emit_use (hard_frame_pointer_rtx);
4860 /* Retain a map of the prologue insns. */
4861 record_insns (seq, &prologue);
4862 emit_note (NOTE_INSN_PROLOGUE_END);
4864 #ifndef PROFILE_BEFORE_PROLOGUE
4865 /* Ensure that instructions are not moved into the prologue when
4866 profiling is on. The call to the profiling routine can be
4867 emitted within the live range of a call-clobbered register. */
4869 emit_insn (gen_blockage ());
4874 set_insn_locators (seq, prologue_locator);
4876 /* Can't deal with multiple successors of the entry block
4877 at the moment. Function should always have at least one
4879 gcc_assert (single_succ_p (ENTRY_BLOCK_PTR));
4881 insert_insn_on_edge (seq, single_succ_edge (ENTRY_BLOCK_PTR));
4886 /* If the exit block has no non-fake predecessors, we don't need
4888 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
4889 if ((e->flags & EDGE_FAKE) == 0)
4894 rtl_profile_for_bb (EXIT_BLOCK_PTR);
4896 if (optimize && HAVE_return)
4898 /* If we're allowed to generate a simple return instruction,
4899 then by definition we don't need a full epilogue. Examine
4900 the block that falls through to EXIT. If it does not
4901 contain any code, examine its predecessors and try to
4902 emit (conditional) return instructions. */
4907 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
4908 if (e->flags & EDGE_FALLTHRU)
4914 /* Verify that there are no active instructions in the last block. */
4915 label = BB_END (last);
4916 while (label && !LABEL_P (label))
4918 if (active_insn_p (label))
4920 label = PREV_INSN (label);
4923 if (BB_HEAD (last) == label && LABEL_P (label))
4927 for (ei2 = ei_start (last->preds); (e = ei_safe_edge (ei2)); )
4929 basic_block bb = e->src;
4932 if (bb == ENTRY_BLOCK_PTR)
4939 if (!JUMP_P (jump) || JUMP_LABEL (jump) != label)
4945 /* If we have an unconditional jump, we can replace that
4946 with a simple return instruction. */
4947 if (simplejump_p (jump))
4949 emit_return_into_block (bb);
4953 /* If we have a conditional jump, we can try to replace
4954 that with a conditional return instruction. */
4955 else if (condjump_p (jump))
4957 if (! redirect_jump (jump, 0, 0))
4963 /* If this block has only one successor, it both jumps
4964 and falls through to the fallthru block, so we can't
4966 if (single_succ_p (bb))
4978 /* Fix up the CFG for the successful change we just made. */
4979 redirect_edge_succ (e, EXIT_BLOCK_PTR);
4982 /* Emit a return insn for the exit fallthru block. Whether
4983 this is still reachable will be determined later. */
4985 emit_barrier_after (BB_END (last));
4986 emit_return_into_block (last);
4987 epilogue_end = BB_END (last);
4988 single_succ_edge (last)->flags &= ~EDGE_FALLTHRU;
4993 /* Find the edge that falls through to EXIT. Other edges may exist
4994 due to RETURN instructions, but those don't need epilogues.
4995 There really shouldn't be a mixture -- either all should have
4996 been converted or none, however... */
4998 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
4999 if (e->flags & EDGE_FALLTHRU)
5004 #ifdef HAVE_epilogue
5008 epilogue_end = emit_note (NOTE_INSN_EPILOGUE_BEG);
5009 seq = gen_epilogue ();
5010 emit_jump_insn (seq);
5012 /* Retain a map of the epilogue insns. */
5013 record_insns (seq, &epilogue);
5014 set_insn_locators (seq, epilogue_locator);
5019 insert_insn_on_edge (seq, e);
5027 if (! next_active_insn (BB_END (e->src)))
5029 /* We have a fall-through edge to the exit block, the source is not
5030 at the end of the function, and there will be an assembler epilogue
5031 at the end of the function.
5032 We can't use force_nonfallthru here, because that would try to
5033 use return. Inserting a jump 'by hand' is extremely messy, so
5034 we take advantage of cfg_layout_finalize using
5035 fixup_fallthru_exit_predecessor. */
5036 cfg_layout_initialize (0);
5037 FOR_EACH_BB (cur_bb)
5038 if (cur_bb->index >= NUM_FIXED_BLOCKS
5039 && cur_bb->next_bb->index >= NUM_FIXED_BLOCKS)
5040 cur_bb->aux = cur_bb->next_bb;
5041 cfg_layout_finalize ();
5044 default_rtl_profile ();
5048 commit_edge_insertions ();
5050 /* The epilogue insns we inserted may cause the exit edge to no longer
5052 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5054 if (((e->flags & EDGE_FALLTHRU) != 0)
5055 && returnjump_p (BB_END (e->src)))
5056 e->flags &= ~EDGE_FALLTHRU;
5060 #ifdef HAVE_sibcall_epilogue
5061 /* Emit sibling epilogues before any sibling call sites. */
5062 for (ei = ei_start (EXIT_BLOCK_PTR->preds); (e = ei_safe_edge (ei)); )
5064 basic_block bb = e->src;
5065 rtx insn = BB_END (bb);
5068 || ! SIBLING_CALL_P (insn))
5075 emit_insn (gen_sibcall_epilogue ());
5079 /* Retain a map of the epilogue insns. Used in life analysis to
5080 avoid getting rid of sibcall epilogue insns. Do this before we
5081 actually emit the sequence. */
5082 record_insns (seq, &sibcall_epilogue);
5083 set_insn_locators (seq, epilogue_locator);
5085 emit_insn_before (seq, insn);
5090 #ifdef HAVE_epilogue
5095 /* Similarly, move any line notes that appear after the epilogue.
5096 There is no need, however, to be quite so anal about the existence
5097 of such a note. Also possibly move
5098 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
5100 for (insn = epilogue_end; insn; insn = next)
5102 next = NEXT_INSN (insn);
5104 && (NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG))
5105 reorder_insns (insn, insn, PREV_INSN (epilogue_end));
5110 /* Threading the prologue and epilogue changes the artificial refs
5111 in the entry and exit blocks. */
5112 epilogue_completed = 1;
5113 df_update_entry_exit_and_calls ();
5116 /* Reposition the prologue-end and epilogue-begin notes after instruction
5117 scheduling and delayed branch scheduling. */
5120 reposition_prologue_and_epilogue_notes (void)
5122 #if defined (HAVE_prologue) || defined (HAVE_epilogue)
5123 rtx insn, last, note;
5126 if ((len = VEC_length (int, prologue)) > 0)
5130 /* Scan from the beginning until we reach the last prologue insn.
5131 We apparently can't depend on basic_block_{head,end} after
5133 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
5137 if (NOTE_KIND (insn) == NOTE_INSN_PROLOGUE_END)
5140 else if (contains (insn, &prologue))
5150 /* Find the prologue-end note if we haven't already, and
5151 move it to just after the last prologue insn. */
5154 for (note = last; (note = NEXT_INSN (note));)
5156 && NOTE_KIND (note) == NOTE_INSN_PROLOGUE_END)
5160 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
5162 last = NEXT_INSN (last);
5163 reorder_insns (note, note, last);
5167 if ((len = VEC_length (int, epilogue)) > 0)
5171 /* Scan from the end until we reach the first epilogue insn.
5172 We apparently can't depend on basic_block_{head,end} after
5174 for (insn = get_last_insn (); insn; insn = PREV_INSN (insn))
5178 if (NOTE_KIND (insn) == NOTE_INSN_EPILOGUE_BEG)
5181 else if (contains (insn, &epilogue))
5191 /* Find the epilogue-begin note if we haven't already, and
5192 move it to just before the first epilogue insn. */
5195 for (note = insn; (note = PREV_INSN (note));)
5197 && NOTE_KIND (note) == NOTE_INSN_EPILOGUE_BEG)
5201 if (PREV_INSN (last) != note)
5202 reorder_insns (note, note, PREV_INSN (last));
5205 #endif /* HAVE_prologue or HAVE_epilogue */
5208 /* Returns the name of the current function. */
5210 current_function_name (void)
5212 return lang_hooks.decl_printable_name (cfun->decl, 2);
5215 /* Returns the raw (mangled) name of the current function. */
5217 current_function_assembler_name (void)
5219 return IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (cfun->decl));
5224 rest_of_handle_check_leaf_regs (void)
5226 #ifdef LEAF_REGISTERS
5227 current_function_uses_only_leaf_regs
5228 = optimize > 0 && only_leaf_regs_used () && leaf_function_p ();
5233 /* Insert a TYPE into the used types hash table of CFUN. */
5235 used_types_insert_helper (tree type, struct function *func)
5237 if (type != NULL && func != NULL)
5241 if (func->used_types_hash == NULL)
5242 func->used_types_hash = htab_create_ggc (37, htab_hash_pointer,
5243 htab_eq_pointer, NULL);
5244 slot = htab_find_slot (func->used_types_hash, type, INSERT);
5250 /* Given a type, insert it into the used hash table in cfun. */
5252 used_types_insert (tree t)
5254 while (POINTER_TYPE_P (t) || TREE_CODE (t) == ARRAY_TYPE)
5256 t = TYPE_MAIN_VARIANT (t);
5257 if (debug_info_level > DINFO_LEVEL_NONE)
5258 used_types_insert_helper (t, cfun);
5261 struct rtl_opt_pass pass_leaf_regs =
5267 rest_of_handle_check_leaf_regs, /* execute */
5270 0, /* static_pass_number */
5272 0, /* properties_required */
5273 0, /* properties_provided */
5274 0, /* properties_destroyed */
5275 0, /* todo_flags_start */
5276 0 /* todo_flags_finish */
5281 rest_of_handle_thread_prologue_and_epilogue (void)
5284 cleanup_cfg (CLEANUP_EXPENSIVE);
5285 /* On some machines, the prologue and epilogue code, or parts thereof,
5286 can be represented as RTL. Doing so lets us schedule insns between
5287 it and the rest of the code and also allows delayed branch
5288 scheduling to operate in the epilogue. */
5290 thread_prologue_and_epilogue_insns ();
5294 struct rtl_opt_pass pass_thread_prologue_and_epilogue =
5298 "pro_and_epilogue", /* name */
5300 rest_of_handle_thread_prologue_and_epilogue, /* execute */
5303 0, /* static_pass_number */
5304 TV_THREAD_PROLOGUE_AND_EPILOGUE, /* tv_id */
5305 0, /* properties_required */
5306 0, /* properties_provided */
5307 0, /* properties_destroyed */
5308 TODO_verify_flow, /* todo_flags_start */
5311 TODO_df_finish | TODO_verify_rtl_sharing |
5312 TODO_ggc_collect /* todo_flags_finish */
5317 /* This mini-pass fixes fall-out from SSA in asm statements that have
5318 in-out constraints. Say you start with
5321 asm ("": "+mr" (inout));
5324 which is transformed very early to use explicit output and match operands:
5327 asm ("": "=mr" (inout) : "0" (inout));
5330 Or, after SSA and copyprop,
5332 asm ("": "=mr" (inout_2) : "0" (inout_1));
5335 Clearly inout_2 and inout_1 can't be coalesced easily anymore, as
5336 they represent two separate values, so they will get different pseudo
5337 registers during expansion. Then, since the two operands need to match
5338 per the constraints, but use different pseudo registers, reload can
5339 only register a reload for these operands. But reloads can only be
5340 satisfied by hardregs, not by memory, so we need a register for this
5341 reload, just because we are presented with non-matching operands.
5342 So, even though we allow memory for this operand, no memory can be
5343 used for it, just because the two operands don't match. This can
5344 cause reload failures on register-starved targets.
5346 So it's a symptom of reload not being able to use memory for reloads
5347 or, alternatively it's also a symptom of both operands not coming into
5348 reload as matching (in which case the pseudo could go to memory just
5349 fine, as the alternative allows it, and no reload would be necessary).
5350 We fix the latter problem here, by transforming
5352 asm ("": "=mr" (inout_2) : "0" (inout_1));
5357 asm ("": "=mr" (inout_2) : "0" (inout_2)); */
5360 match_asm_constraints_1 (rtx insn, rtx *p_sets, int noutputs)
5363 bool changed = false;
5364 rtx op = SET_SRC (p_sets[0]);
5365 int ninputs = ASM_OPERANDS_INPUT_LENGTH (op);
5366 rtvec inputs = ASM_OPERANDS_INPUT_VEC (op);
5367 bool *output_matched = XALLOCAVEC (bool, noutputs);
5369 memset (output_matched, 0, noutputs * sizeof (bool));
5370 for (i = 0; i < ninputs; i++)
5372 rtx input, output, insns;
5373 const char *constraint = ASM_OPERANDS_INPUT_CONSTRAINT (op, i);
5377 match = strtoul (constraint, &end, 10);
5378 if (end == constraint)
5381 gcc_assert (match < noutputs);
5382 output = SET_DEST (p_sets[match]);
5383 input = RTVEC_ELT (inputs, i);
5384 /* Only do the transformation for pseudos. */
5385 if (! REG_P (output)
5386 || rtx_equal_p (output, input)
5387 || (GET_MODE (input) != VOIDmode
5388 && GET_MODE (input) != GET_MODE (output)))
5391 /* We can't do anything if the output is also used as input,
5392 as we're going to overwrite it. */
5393 for (j = 0; j < ninputs; j++)
5394 if (reg_overlap_mentioned_p (output, RTVEC_ELT (inputs, j)))
5399 /* Avoid changing the same input several times. For
5400 asm ("" : "=mr" (out1), "=mr" (out2) : "0" (in), "1" (in));
5401 only change in once (to out1), rather than changing it
5402 first to out1 and afterwards to out2. */
5405 for (j = 0; j < noutputs; j++)
5406 if (output_matched[j] && input == SET_DEST (p_sets[j]))
5411 output_matched[match] = true;
5414 emit_move_insn (output, input);
5415 insns = get_insns ();
5417 emit_insn_before (insns, insn);
5419 /* Now replace all mentions of the input with output. We can't
5420 just replace the occurrence in inputs[i], as the register might
5421 also be used in some other input (or even in an address of an
5422 output), which would mean possibly increasing the number of
5423 inputs by one (namely 'output' in addition), which might pose
5424 a too complicated problem for reload to solve. E.g. this situation:
5426 asm ("" : "=r" (output), "=m" (input) : "0" (input))
5428 Here 'input' is used in two occurrences as input (once for the
5429 input operand, once for the address in the second output operand).
5430 If we would replace only the occurrence of the input operand (to
5431 make the matching) we would be left with this:
5434 asm ("" : "=r" (output), "=m" (input) : "0" (output))
5436 Now we suddenly have two different input values (containing the same
5437 value, but different pseudos) where we formerly had only one.
5438 With more complicated asms this might lead to reload failures
5439 which wouldn't have happen without this pass. So, iterate over
5440 all operands and replace all occurrences of the register used. */
5441 for (j = 0; j < noutputs; j++)
5442 if (!rtx_equal_p (SET_DEST (p_sets[j]), input)
5443 && reg_overlap_mentioned_p (input, SET_DEST (p_sets[j])))
5444 SET_DEST (p_sets[j]) = replace_rtx (SET_DEST (p_sets[j]),
5446 for (j = 0; j < ninputs; j++)
5447 if (reg_overlap_mentioned_p (input, RTVEC_ELT (inputs, j)))
5448 RTVEC_ELT (inputs, j) = replace_rtx (RTVEC_ELT (inputs, j),
5455 df_insn_rescan (insn);
5459 rest_of_match_asm_constraints (void)
5462 rtx insn, pat, *p_sets;
5465 if (!crtl->has_asm_statement)
5468 df_set_flags (DF_DEFER_INSN_RESCAN);
5471 FOR_BB_INSNS (bb, insn)
5476 pat = PATTERN (insn);
5477 if (GET_CODE (pat) == PARALLEL)
5478 p_sets = &XVECEXP (pat, 0, 0), noutputs = XVECLEN (pat, 0);
5479 else if (GET_CODE (pat) == SET)
5480 p_sets = &PATTERN (insn), noutputs = 1;
5484 if (GET_CODE (*p_sets) == SET
5485 && GET_CODE (SET_SRC (*p_sets)) == ASM_OPERANDS)
5486 match_asm_constraints_1 (insn, p_sets, noutputs);
5490 return TODO_df_finish;
5493 struct rtl_opt_pass pass_match_asm_constraints =
5497 "asmcons", /* name */
5499 rest_of_match_asm_constraints, /* execute */
5502 0, /* static_pass_number */
5504 0, /* properties_required */
5505 0, /* properties_provided */
5506 0, /* properties_destroyed */
5507 0, /* todo_flags_start */
5508 TODO_dump_func /* todo_flags_finish */
5513 #include "gt-function.h"