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));
1524 /* At this point, X contains the new value for the operand.
1525 Validate the new value vs the insn predicate. Note that
1526 asm insns will have insn_code -1 here. */
1527 if (!safe_insn_predicate (insn_code, i, x))
1530 x = force_reg (insn_data[insn_code].operand[i].mode, x);
1534 emit_insn_before (seq, insn);
1537 *recog_data.operand_loc[i] = recog_data.operand[i] = x;
1543 /* Propagate operand changes into the duplicates. */
1544 for (i = 0; i < recog_data.n_dups; ++i)
1545 *recog_data.dup_loc[i]
1546 = copy_rtx (recog_data.operand[(unsigned)recog_data.dup_num[i]]);
1548 /* Force re-recognition of the instruction for validation. */
1549 INSN_CODE (insn) = -1;
1552 if (asm_noperands (PATTERN (insn)) >= 0)
1554 if (!check_asm_operands (PATTERN (insn)))
1556 error_for_asm (insn, "impossible constraint in %<asm%>");
1562 if (recog_memoized (insn) < 0)
1563 fatal_insn_not_found (insn);
1567 /* Subroutine of instantiate_decls. Given RTL representing a decl,
1568 do any instantiation required. */
1571 instantiate_decl_rtl (rtx x)
1578 /* If this is a CONCAT, recurse for the pieces. */
1579 if (GET_CODE (x) == CONCAT)
1581 instantiate_decl_rtl (XEXP (x, 0));
1582 instantiate_decl_rtl (XEXP (x, 1));
1586 /* If this is not a MEM, no need to do anything. Similarly if the
1587 address is a constant or a register that is not a virtual register. */
1592 if (CONSTANT_P (addr)
1594 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
1595 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
1598 for_each_rtx (&XEXP (x, 0), instantiate_virtual_regs_in_rtx, NULL);
1601 /* Helper for instantiate_decls called via walk_tree: Process all decls
1602 in the given DECL_VALUE_EXPR. */
1605 instantiate_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1611 if (DECL_P (t) && DECL_RTL_SET_P (t))
1612 instantiate_decl_rtl (DECL_RTL (t));
1617 /* Subroutine of instantiate_decls: Process all decls in the given
1618 BLOCK node and all its subblocks. */
1621 instantiate_decls_1 (tree let)
1625 for (t = BLOCK_VARS (let); t; t = TREE_CHAIN (t))
1627 if (DECL_RTL_SET_P (t))
1628 instantiate_decl_rtl (DECL_RTL (t));
1629 if (TREE_CODE (t) == VAR_DECL && DECL_HAS_VALUE_EXPR_P (t))
1631 tree v = DECL_VALUE_EXPR (t);
1632 walk_tree (&v, instantiate_expr, NULL, NULL);
1636 /* Process all subblocks. */
1637 for (t = BLOCK_SUBBLOCKS (let); t; t = BLOCK_CHAIN (t))
1638 instantiate_decls_1 (t);
1641 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1642 all virtual registers in their DECL_RTL's. */
1645 instantiate_decls (tree fndecl)
1649 /* Process all parameters of the function. */
1650 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = TREE_CHAIN (decl))
1652 instantiate_decl_rtl (DECL_RTL (decl));
1653 instantiate_decl_rtl (DECL_INCOMING_RTL (decl));
1654 if (DECL_HAS_VALUE_EXPR_P (decl))
1656 tree v = DECL_VALUE_EXPR (decl);
1657 walk_tree (&v, instantiate_expr, NULL, NULL);
1661 /* Now process all variables defined in the function or its subblocks. */
1662 instantiate_decls_1 (DECL_INITIAL (fndecl));
1665 /* Pass through the INSNS of function FNDECL and convert virtual register
1666 references to hard register references. */
1669 instantiate_virtual_regs (void)
1673 /* Compute the offsets to use for this function. */
1674 in_arg_offset = FIRST_PARM_OFFSET (current_function_decl);
1675 var_offset = STARTING_FRAME_OFFSET;
1676 dynamic_offset = STACK_DYNAMIC_OFFSET (current_function_decl);
1677 out_arg_offset = STACK_POINTER_OFFSET;
1678 #ifdef FRAME_POINTER_CFA_OFFSET
1679 cfa_offset = FRAME_POINTER_CFA_OFFSET (current_function_decl);
1681 cfa_offset = ARG_POINTER_CFA_OFFSET (current_function_decl);
1684 /* Initialize recognition, indicating that volatile is OK. */
1687 /* Scan through all the insns, instantiating every virtual register still
1689 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
1692 /* These patterns in the instruction stream can never be recognized.
1693 Fortunately, they shouldn't contain virtual registers either. */
1694 if (GET_CODE (PATTERN (insn)) == USE
1695 || GET_CODE (PATTERN (insn)) == CLOBBER
1696 || GET_CODE (PATTERN (insn)) == ADDR_VEC
1697 || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC
1698 || GET_CODE (PATTERN (insn)) == ASM_INPUT)
1701 instantiate_virtual_regs_in_insn (insn);
1703 if (INSN_DELETED_P (insn))
1706 for_each_rtx (®_NOTES (insn), instantiate_virtual_regs_in_rtx, NULL);
1708 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
1709 if (GET_CODE (insn) == CALL_INSN)
1710 for_each_rtx (&CALL_INSN_FUNCTION_USAGE (insn),
1711 instantiate_virtual_regs_in_rtx, NULL);
1714 /* Instantiate the virtual registers in the DECLs for debugging purposes. */
1715 instantiate_decls (current_function_decl);
1717 targetm.instantiate_decls ();
1719 /* Indicate that, from now on, assign_stack_local should use
1720 frame_pointer_rtx. */
1721 virtuals_instantiated = 1;
1725 struct rtl_opt_pass pass_instantiate_virtual_regs =
1731 instantiate_virtual_regs, /* execute */
1734 0, /* static_pass_number */
1736 0, /* properties_required */
1737 0, /* properties_provided */
1738 0, /* properties_destroyed */
1739 0, /* todo_flags_start */
1740 TODO_dump_func /* todo_flags_finish */
1745 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
1746 This means a type for which function calls must pass an address to the
1747 function or get an address back from the function.
1748 EXP may be a type node or an expression (whose type is tested). */
1751 aggregate_value_p (const_tree exp, const_tree fntype)
1753 int i, regno, nregs;
1756 const_tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
1758 /* DECL node associated with FNTYPE when relevant, which we might need to
1759 check for by-invisible-reference returns, typically for CALL_EXPR input
1761 const_tree fndecl = NULL_TREE;
1764 switch (TREE_CODE (fntype))
1767 fndecl = get_callee_fndecl (fntype);
1768 fntype = fndecl ? TREE_TYPE (fndecl) : 0;
1772 fntype = TREE_TYPE (fndecl);
1777 case IDENTIFIER_NODE:
1781 /* We don't expect other rtl types here. */
1785 if (TREE_CODE (type) == VOID_TYPE)
1788 /* If the front end has decided that this needs to be passed by
1789 reference, do so. */
1790 if ((TREE_CODE (exp) == PARM_DECL || TREE_CODE (exp) == RESULT_DECL)
1791 && DECL_BY_REFERENCE (exp))
1794 /* If the EXPression is a CALL_EXPR, honor DECL_BY_REFERENCE set on the
1795 called function RESULT_DECL, meaning the function returns in memory by
1796 invisible reference. This check lets front-ends not set TREE_ADDRESSABLE
1797 on the function type, which used to be the way to request such a return
1798 mechanism but might now be causing troubles at gimplification time if
1799 temporaries with the function type need to be created. */
1800 if (TREE_CODE (exp) == CALL_EXPR && fndecl && DECL_RESULT (fndecl)
1801 && DECL_BY_REFERENCE (DECL_RESULT (fndecl)))
1804 if (targetm.calls.return_in_memory (type, fntype))
1806 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
1807 and thus can't be returned in registers. */
1808 if (TREE_ADDRESSABLE (type))
1810 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
1812 /* Make sure we have suitable call-clobbered regs to return
1813 the value in; if not, we must return it in memory. */
1814 reg = hard_function_value (type, 0, fntype, 0);
1816 /* If we have something other than a REG (e.g. a PARALLEL), then assume
1821 regno = REGNO (reg);
1822 nregs = hard_regno_nregs[regno][TYPE_MODE (type)];
1823 for (i = 0; i < nregs; i++)
1824 if (! call_used_regs[regno + i])
1829 /* Return true if we should assign DECL a pseudo register; false if it
1830 should live on the local stack. */
1833 use_register_for_decl (const_tree decl)
1835 if (!targetm.calls.allocate_stack_slots_for_args())
1838 /* Honor volatile. */
1839 if (TREE_SIDE_EFFECTS (decl))
1842 /* Honor addressability. */
1843 if (TREE_ADDRESSABLE (decl))
1846 /* Only register-like things go in registers. */
1847 if (DECL_MODE (decl) == BLKmode)
1850 /* If -ffloat-store specified, don't put explicit float variables
1852 /* ??? This should be checked after DECL_ARTIFICIAL, but tree-ssa
1853 propagates values across these stores, and it probably shouldn't. */
1854 if (flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)))
1857 /* If we're not interested in tracking debugging information for
1858 this decl, then we can certainly put it in a register. */
1859 if (DECL_IGNORED_P (decl))
1862 return (optimize || DECL_REGISTER (decl));
1865 /* Return true if TYPE should be passed by invisible reference. */
1868 pass_by_reference (CUMULATIVE_ARGS *ca, enum machine_mode mode,
1869 tree type, bool named_arg)
1873 /* If this type contains non-trivial constructors, then it is
1874 forbidden for the middle-end to create any new copies. */
1875 if (TREE_ADDRESSABLE (type))
1878 /* GCC post 3.4 passes *all* variable sized types by reference. */
1879 if (!TYPE_SIZE (type) || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
1883 return targetm.calls.pass_by_reference (ca, mode, type, named_arg);
1886 /* Return true if TYPE, which is passed by reference, should be callee
1887 copied instead of caller copied. */
1890 reference_callee_copied (CUMULATIVE_ARGS *ca, enum machine_mode mode,
1891 tree type, bool named_arg)
1893 if (type && TREE_ADDRESSABLE (type))
1895 return targetm.calls.callee_copies (ca, mode, type, named_arg);
1898 /* Structures to communicate between the subroutines of assign_parms.
1899 The first holds data persistent across all parameters, the second
1900 is cleared out for each parameter. */
1902 struct assign_parm_data_all
1904 CUMULATIVE_ARGS args_so_far;
1905 struct args_size stack_args_size;
1906 tree function_result_decl;
1908 rtx first_conversion_insn;
1909 rtx last_conversion_insn;
1910 HOST_WIDE_INT pretend_args_size;
1911 HOST_WIDE_INT extra_pretend_bytes;
1912 int reg_parm_stack_space;
1915 struct assign_parm_data_one
1921 enum machine_mode nominal_mode;
1922 enum machine_mode passed_mode;
1923 enum machine_mode promoted_mode;
1924 struct locate_and_pad_arg_data locate;
1926 BOOL_BITFIELD named_arg : 1;
1927 BOOL_BITFIELD passed_pointer : 1;
1928 BOOL_BITFIELD on_stack : 1;
1929 BOOL_BITFIELD loaded_in_reg : 1;
1932 /* A subroutine of assign_parms. Initialize ALL. */
1935 assign_parms_initialize_all (struct assign_parm_data_all *all)
1939 memset (all, 0, sizeof (*all));
1941 fntype = TREE_TYPE (current_function_decl);
1943 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
1944 INIT_CUMULATIVE_INCOMING_ARGS (all->args_so_far, fntype, NULL_RTX);
1946 INIT_CUMULATIVE_ARGS (all->args_so_far, fntype, NULL_RTX,
1947 current_function_decl, -1);
1950 #ifdef REG_PARM_STACK_SPACE
1951 all->reg_parm_stack_space = REG_PARM_STACK_SPACE (current_function_decl);
1955 /* If ARGS contains entries with complex types, split the entry into two
1956 entries of the component type. Return a new list of substitutions are
1957 needed, else the old list. */
1960 split_complex_args (tree args)
1964 /* Before allocating memory, check for the common case of no complex. */
1965 for (p = args; p; p = TREE_CHAIN (p))
1967 tree type = TREE_TYPE (p);
1968 if (TREE_CODE (type) == COMPLEX_TYPE
1969 && targetm.calls.split_complex_arg (type))
1975 args = copy_list (args);
1977 for (p = args; p; p = TREE_CHAIN (p))
1979 tree type = TREE_TYPE (p);
1980 if (TREE_CODE (type) == COMPLEX_TYPE
1981 && targetm.calls.split_complex_arg (type))
1984 tree subtype = TREE_TYPE (type);
1985 bool addressable = TREE_ADDRESSABLE (p);
1987 /* Rewrite the PARM_DECL's type with its component. */
1988 TREE_TYPE (p) = subtype;
1989 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
1990 DECL_MODE (p) = VOIDmode;
1991 DECL_SIZE (p) = NULL;
1992 DECL_SIZE_UNIT (p) = NULL;
1993 /* If this arg must go in memory, put it in a pseudo here.
1994 We can't allow it to go in memory as per normal parms,
1995 because the usual place might not have the imag part
1996 adjacent to the real part. */
1997 DECL_ARTIFICIAL (p) = addressable;
1998 DECL_IGNORED_P (p) = addressable;
1999 TREE_ADDRESSABLE (p) = 0;
2002 /* Build a second synthetic decl. */
2003 decl = build_decl (PARM_DECL, NULL_TREE, subtype);
2004 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
2005 DECL_ARTIFICIAL (decl) = addressable;
2006 DECL_IGNORED_P (decl) = addressable;
2007 layout_decl (decl, 0);
2009 /* Splice it in; skip the new decl. */
2010 TREE_CHAIN (decl) = TREE_CHAIN (p);
2011 TREE_CHAIN (p) = decl;
2019 /* A subroutine of assign_parms. Adjust the parameter list to incorporate
2020 the hidden struct return argument, and (abi willing) complex args.
2021 Return the new parameter list. */
2024 assign_parms_augmented_arg_list (struct assign_parm_data_all *all)
2026 tree fndecl = current_function_decl;
2027 tree fntype = TREE_TYPE (fndecl);
2028 tree fnargs = DECL_ARGUMENTS (fndecl);
2030 /* If struct value address is treated as the first argument, make it so. */
2031 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
2032 && ! cfun->returns_pcc_struct
2033 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
2035 tree type = build_pointer_type (TREE_TYPE (fntype));
2038 decl = build_decl (PARM_DECL, NULL_TREE, type);
2039 DECL_ARG_TYPE (decl) = type;
2040 DECL_ARTIFICIAL (decl) = 1;
2041 DECL_IGNORED_P (decl) = 1;
2043 TREE_CHAIN (decl) = fnargs;
2045 all->function_result_decl = decl;
2048 all->orig_fnargs = fnargs;
2050 /* If the target wants to split complex arguments into scalars, do so. */
2051 if (targetm.calls.split_complex_arg)
2052 fnargs = split_complex_args (fnargs);
2057 /* A subroutine of assign_parms. Examine PARM and pull out type and mode
2058 data for the parameter. Incorporate ABI specifics such as pass-by-
2059 reference and type promotion. */
2062 assign_parm_find_data_types (struct assign_parm_data_all *all, tree parm,
2063 struct assign_parm_data_one *data)
2065 tree nominal_type, passed_type;
2066 enum machine_mode nominal_mode, passed_mode, promoted_mode;
2068 memset (data, 0, sizeof (*data));
2070 /* NAMED_ARG is a misnomer. We really mean 'non-variadic'. */
2072 data->named_arg = 1; /* No variadic parms. */
2073 else if (TREE_CHAIN (parm))
2074 data->named_arg = 1; /* Not the last non-variadic parm. */
2075 else if (targetm.calls.strict_argument_naming (&all->args_so_far))
2076 data->named_arg = 1; /* Only variadic ones are unnamed. */
2078 data->named_arg = 0; /* Treat as variadic. */
2080 nominal_type = TREE_TYPE (parm);
2081 passed_type = DECL_ARG_TYPE (parm);
2083 /* Look out for errors propagating this far. Also, if the parameter's
2084 type is void then its value doesn't matter. */
2085 if (TREE_TYPE (parm) == error_mark_node
2086 /* This can happen after weird syntax errors
2087 or if an enum type is defined among the parms. */
2088 || TREE_CODE (parm) != PARM_DECL
2089 || passed_type == NULL
2090 || VOID_TYPE_P (nominal_type))
2092 nominal_type = passed_type = void_type_node;
2093 nominal_mode = passed_mode = promoted_mode = VOIDmode;
2097 /* Find mode of arg as it is passed, and mode of arg as it should be
2098 during execution of this function. */
2099 passed_mode = TYPE_MODE (passed_type);
2100 nominal_mode = TYPE_MODE (nominal_type);
2102 /* If the parm is to be passed as a transparent union, use the type of
2103 the first field for the tests below. We have already verified that
2104 the modes are the same. */
2105 if (TREE_CODE (passed_type) == UNION_TYPE
2106 && TYPE_TRANSPARENT_UNION (passed_type))
2107 passed_type = TREE_TYPE (TYPE_FIELDS (passed_type));
2109 /* See if this arg was passed by invisible reference. */
2110 if (pass_by_reference (&all->args_so_far, passed_mode,
2111 passed_type, data->named_arg))
2113 passed_type = nominal_type = build_pointer_type (passed_type);
2114 data->passed_pointer = true;
2115 passed_mode = nominal_mode = Pmode;
2118 /* Find mode as it is passed by the ABI. */
2119 promoted_mode = passed_mode;
2120 if (targetm.calls.promote_function_args (TREE_TYPE (current_function_decl)))
2122 int unsignedp = TYPE_UNSIGNED (passed_type);
2123 promoted_mode = promote_mode (passed_type, promoted_mode,
2128 data->nominal_type = nominal_type;
2129 data->passed_type = passed_type;
2130 data->nominal_mode = nominal_mode;
2131 data->passed_mode = passed_mode;
2132 data->promoted_mode = promoted_mode;
2135 /* A subroutine of assign_parms. Invoke setup_incoming_varargs. */
2138 assign_parms_setup_varargs (struct assign_parm_data_all *all,
2139 struct assign_parm_data_one *data, bool no_rtl)
2141 int varargs_pretend_bytes = 0;
2143 targetm.calls.setup_incoming_varargs (&all->args_so_far,
2144 data->promoted_mode,
2146 &varargs_pretend_bytes, no_rtl);
2148 /* If the back-end has requested extra stack space, record how much is
2149 needed. Do not change pretend_args_size otherwise since it may be
2150 nonzero from an earlier partial argument. */
2151 if (varargs_pretend_bytes > 0)
2152 all->pretend_args_size = varargs_pretend_bytes;
2155 /* A subroutine of assign_parms. Set DATA->ENTRY_PARM corresponding to
2156 the incoming location of the current parameter. */
2159 assign_parm_find_entry_rtl (struct assign_parm_data_all *all,
2160 struct assign_parm_data_one *data)
2162 HOST_WIDE_INT pretend_bytes = 0;
2166 if (data->promoted_mode == VOIDmode)
2168 data->entry_parm = data->stack_parm = const0_rtx;
2172 #ifdef FUNCTION_INCOMING_ARG
2173 entry_parm = FUNCTION_INCOMING_ARG (all->args_so_far, data->promoted_mode,
2174 data->passed_type, data->named_arg);
2176 entry_parm = FUNCTION_ARG (all->args_so_far, data->promoted_mode,
2177 data->passed_type, data->named_arg);
2180 if (entry_parm == 0)
2181 data->promoted_mode = data->passed_mode;
2183 /* Determine parm's home in the stack, in case it arrives in the stack
2184 or we should pretend it did. Compute the stack position and rtx where
2185 the argument arrives and its size.
2187 There is one complexity here: If this was a parameter that would
2188 have been passed in registers, but wasn't only because it is
2189 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2190 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2191 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of 0
2192 as it was the previous time. */
2193 in_regs = entry_parm != 0;
2194 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2197 if (!in_regs && !data->named_arg)
2199 if (targetm.calls.pretend_outgoing_varargs_named (&all->args_so_far))
2202 #ifdef FUNCTION_INCOMING_ARG
2203 tem = FUNCTION_INCOMING_ARG (all->args_so_far, data->promoted_mode,
2204 data->passed_type, true);
2206 tem = FUNCTION_ARG (all->args_so_far, data->promoted_mode,
2207 data->passed_type, true);
2209 in_regs = tem != NULL;
2213 /* If this parameter was passed both in registers and in the stack, use
2214 the copy on the stack. */
2215 if (targetm.calls.must_pass_in_stack (data->promoted_mode,
2223 partial = targetm.calls.arg_partial_bytes (&all->args_so_far,
2224 data->promoted_mode,
2227 data->partial = partial;
2229 /* The caller might already have allocated stack space for the
2230 register parameters. */
2231 if (partial != 0 && all->reg_parm_stack_space == 0)
2233 /* Part of this argument is passed in registers and part
2234 is passed on the stack. Ask the prologue code to extend
2235 the stack part so that we can recreate the full value.
2237 PRETEND_BYTES is the size of the registers we need to store.
2238 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
2239 stack space that the prologue should allocate.
2241 Internally, gcc assumes that the argument pointer is aligned
2242 to STACK_BOUNDARY bits. This is used both for alignment
2243 optimizations (see init_emit) and to locate arguments that are
2244 aligned to more than PARM_BOUNDARY bits. We must preserve this
2245 invariant by rounding CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to
2246 a stack boundary. */
2248 /* We assume at most one partial arg, and it must be the first
2249 argument on the stack. */
2250 gcc_assert (!all->extra_pretend_bytes && !all->pretend_args_size);
2252 pretend_bytes = partial;
2253 all->pretend_args_size = CEIL_ROUND (pretend_bytes, STACK_BYTES);
2255 /* We want to align relative to the actual stack pointer, so
2256 don't include this in the stack size until later. */
2257 all->extra_pretend_bytes = all->pretend_args_size;
2261 locate_and_pad_parm (data->promoted_mode, data->passed_type, in_regs,
2262 entry_parm ? data->partial : 0, current_function_decl,
2263 &all->stack_args_size, &data->locate);
2265 /* Update parm_stack_boundary if this parameter is passed in the
2267 if (!in_regs && crtl->parm_stack_boundary < data->locate.boundary)
2268 crtl->parm_stack_boundary = data->locate.boundary;
2270 /* Adjust offsets to include the pretend args. */
2271 pretend_bytes = all->extra_pretend_bytes - pretend_bytes;
2272 data->locate.slot_offset.constant += pretend_bytes;
2273 data->locate.offset.constant += pretend_bytes;
2275 data->entry_parm = entry_parm;
2278 /* A subroutine of assign_parms. If there is actually space on the stack
2279 for this parm, count it in stack_args_size and return true. */
2282 assign_parm_is_stack_parm (struct assign_parm_data_all *all,
2283 struct assign_parm_data_one *data)
2285 /* Trivially true if we've no incoming register. */
2286 if (data->entry_parm == NULL)
2288 /* Also true if we're partially in registers and partially not,
2289 since we've arranged to drop the entire argument on the stack. */
2290 else if (data->partial != 0)
2292 /* Also true if the target says that it's passed in both registers
2293 and on the stack. */
2294 else if (GET_CODE (data->entry_parm) == PARALLEL
2295 && XEXP (XVECEXP (data->entry_parm, 0, 0), 0) == NULL_RTX)
2297 /* Also true if the target says that there's stack allocated for
2298 all register parameters. */
2299 else if (all->reg_parm_stack_space > 0)
2301 /* Otherwise, no, this parameter has no ABI defined stack slot. */
2305 all->stack_args_size.constant += data->locate.size.constant;
2306 if (data->locate.size.var)
2307 ADD_PARM_SIZE (all->stack_args_size, data->locate.size.var);
2312 /* A subroutine of assign_parms. Given that this parameter is allocated
2313 stack space by the ABI, find it. */
2316 assign_parm_find_stack_rtl (tree parm, struct assign_parm_data_one *data)
2318 rtx offset_rtx, stack_parm;
2319 unsigned int align, boundary;
2321 /* If we're passing this arg using a reg, make its stack home the
2322 aligned stack slot. */
2323 if (data->entry_parm)
2324 offset_rtx = ARGS_SIZE_RTX (data->locate.slot_offset);
2326 offset_rtx = ARGS_SIZE_RTX (data->locate.offset);
2328 stack_parm = crtl->args.internal_arg_pointer;
2329 if (offset_rtx != const0_rtx)
2330 stack_parm = gen_rtx_PLUS (Pmode, stack_parm, offset_rtx);
2331 stack_parm = gen_rtx_MEM (data->promoted_mode, stack_parm);
2333 set_mem_attributes (stack_parm, parm, 1);
2335 boundary = data->locate.boundary;
2336 align = BITS_PER_UNIT;
2338 /* If we're padding upward, we know that the alignment of the slot
2339 is FUNCTION_ARG_BOUNDARY. If we're using slot_offset, we're
2340 intentionally forcing upward padding. Otherwise we have to come
2341 up with a guess at the alignment based on OFFSET_RTX. */
2342 if (data->locate.where_pad != downward || data->entry_parm)
2344 else if (GET_CODE (offset_rtx) == CONST_INT)
2346 align = INTVAL (offset_rtx) * BITS_PER_UNIT | boundary;
2347 align = align & -align;
2349 set_mem_align (stack_parm, align);
2351 if (data->entry_parm)
2352 set_reg_attrs_for_parm (data->entry_parm, stack_parm);
2354 data->stack_parm = stack_parm;
2357 /* A subroutine of assign_parms. Adjust DATA->ENTRY_RTL such that it's
2358 always valid and contiguous. */
2361 assign_parm_adjust_entry_rtl (struct assign_parm_data_one *data)
2363 rtx entry_parm = data->entry_parm;
2364 rtx stack_parm = data->stack_parm;
2366 /* If this parm was passed part in regs and part in memory, pretend it
2367 arrived entirely in memory by pushing the register-part onto the stack.
2368 In the special case of a DImode or DFmode that is split, we could put
2369 it together in a pseudoreg directly, but for now that's not worth
2371 if (data->partial != 0)
2373 /* Handle calls that pass values in multiple non-contiguous
2374 locations. The Irix 6 ABI has examples of this. */
2375 if (GET_CODE (entry_parm) == PARALLEL)
2376 emit_group_store (validize_mem (stack_parm), entry_parm,
2378 int_size_in_bytes (data->passed_type));
2381 gcc_assert (data->partial % UNITS_PER_WORD == 0);
2382 move_block_from_reg (REGNO (entry_parm), validize_mem (stack_parm),
2383 data->partial / UNITS_PER_WORD);
2386 entry_parm = stack_parm;
2389 /* If we didn't decide this parm came in a register, by default it came
2391 else if (entry_parm == NULL)
2392 entry_parm = stack_parm;
2394 /* When an argument is passed in multiple locations, we can't make use
2395 of this information, but we can save some copying if the whole argument
2396 is passed in a single register. */
2397 else if (GET_CODE (entry_parm) == PARALLEL
2398 && data->nominal_mode != BLKmode
2399 && data->passed_mode != BLKmode)
2401 size_t i, len = XVECLEN (entry_parm, 0);
2403 for (i = 0; i < len; i++)
2404 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
2405 && REG_P (XEXP (XVECEXP (entry_parm, 0, i), 0))
2406 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
2407 == data->passed_mode)
2408 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
2410 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
2415 data->entry_parm = entry_parm;
2418 /* A subroutine of assign_parms. Reconstitute any values which were
2419 passed in multiple registers and would fit in a single register. */
2422 assign_parm_remove_parallels (struct assign_parm_data_one *data)
2424 rtx entry_parm = data->entry_parm;
2426 /* Convert the PARALLEL to a REG of the same mode as the parallel.
2427 This can be done with register operations rather than on the
2428 stack, even if we will store the reconstituted parameter on the
2430 if (GET_CODE (entry_parm) == PARALLEL && GET_MODE (entry_parm) != BLKmode)
2432 rtx parmreg = gen_reg_rtx (GET_MODE (entry_parm));
2433 emit_group_store (parmreg, entry_parm, NULL_TREE,
2434 GET_MODE_SIZE (GET_MODE (entry_parm)));
2435 entry_parm = parmreg;
2438 data->entry_parm = entry_parm;
2441 /* A subroutine of assign_parms. Adjust DATA->STACK_RTL such that it's
2442 always valid and properly aligned. */
2445 assign_parm_adjust_stack_rtl (struct assign_parm_data_one *data)
2447 rtx stack_parm = data->stack_parm;
2449 /* If we can't trust the parm stack slot to be aligned enough for its
2450 ultimate type, don't use that slot after entry. We'll make another
2451 stack slot, if we need one. */
2453 && ((STRICT_ALIGNMENT
2454 && GET_MODE_ALIGNMENT (data->nominal_mode) > MEM_ALIGN (stack_parm))
2455 || (data->nominal_type
2456 && TYPE_ALIGN (data->nominal_type) > MEM_ALIGN (stack_parm)
2457 && MEM_ALIGN (stack_parm) < PREFERRED_STACK_BOUNDARY)))
2460 /* If parm was passed in memory, and we need to convert it on entry,
2461 don't store it back in that same slot. */
2462 else if (data->entry_parm == stack_parm
2463 && data->nominal_mode != BLKmode
2464 && data->nominal_mode != data->passed_mode)
2467 /* If stack protection is in effect for this function, don't leave any
2468 pointers in their passed stack slots. */
2469 else if (crtl->stack_protect_guard
2470 && (flag_stack_protect == 2
2471 || data->passed_pointer
2472 || POINTER_TYPE_P (data->nominal_type)))
2475 data->stack_parm = stack_parm;
2478 /* A subroutine of assign_parms. Return true if the current parameter
2479 should be stored as a BLKmode in the current frame. */
2482 assign_parm_setup_block_p (struct assign_parm_data_one *data)
2484 if (data->nominal_mode == BLKmode)
2486 if (GET_MODE (data->entry_parm) == BLKmode)
2489 #ifdef BLOCK_REG_PADDING
2490 /* Only assign_parm_setup_block knows how to deal with register arguments
2491 that are padded at the least significant end. */
2492 if (REG_P (data->entry_parm)
2493 && GET_MODE_SIZE (data->promoted_mode) < UNITS_PER_WORD
2494 && (BLOCK_REG_PADDING (data->passed_mode, data->passed_type, 1)
2495 == (BYTES_BIG_ENDIAN ? upward : downward)))
2502 /* A subroutine of assign_parms. Arrange for the parameter to be
2503 present and valid in DATA->STACK_RTL. */
2506 assign_parm_setup_block (struct assign_parm_data_all *all,
2507 tree parm, struct assign_parm_data_one *data)
2509 rtx entry_parm = data->entry_parm;
2510 rtx stack_parm = data->stack_parm;
2512 HOST_WIDE_INT size_stored;
2514 if (GET_CODE (entry_parm) == PARALLEL)
2515 entry_parm = emit_group_move_into_temps (entry_parm);
2517 size = int_size_in_bytes (data->passed_type);
2518 size_stored = CEIL_ROUND (size, UNITS_PER_WORD);
2519 if (stack_parm == 0)
2521 DECL_ALIGN (parm) = MAX (DECL_ALIGN (parm), BITS_PER_WORD);
2522 stack_parm = assign_stack_local (BLKmode, size_stored,
2524 if (GET_MODE_SIZE (GET_MODE (entry_parm)) == size)
2525 PUT_MODE (stack_parm, GET_MODE (entry_parm));
2526 set_mem_attributes (stack_parm, parm, 1);
2529 /* If a BLKmode arrives in registers, copy it to a stack slot. Handle
2530 calls that pass values in multiple non-contiguous locations. */
2531 if (REG_P (entry_parm) || GET_CODE (entry_parm) == PARALLEL)
2535 /* Note that we will be storing an integral number of words.
2536 So we have to be careful to ensure that we allocate an
2537 integral number of words. We do this above when we call
2538 assign_stack_local if space was not allocated in the argument
2539 list. If it was, this will not work if PARM_BOUNDARY is not
2540 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2541 if it becomes a problem. Exception is when BLKmode arrives
2542 with arguments not conforming to word_mode. */
2544 if (data->stack_parm == 0)
2546 else if (GET_CODE (entry_parm) == PARALLEL)
2549 gcc_assert (!size || !(PARM_BOUNDARY % BITS_PER_WORD));
2551 mem = validize_mem (stack_parm);
2553 /* Handle values in multiple non-contiguous locations. */
2554 if (GET_CODE (entry_parm) == PARALLEL)
2556 push_to_sequence2 (all->first_conversion_insn,
2557 all->last_conversion_insn);
2558 emit_group_store (mem, entry_parm, data->passed_type, size);
2559 all->first_conversion_insn = get_insns ();
2560 all->last_conversion_insn = get_last_insn ();
2567 /* If SIZE is that of a mode no bigger than a word, just use
2568 that mode's store operation. */
2569 else if (size <= UNITS_PER_WORD)
2571 enum machine_mode mode
2572 = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
2575 #ifdef BLOCK_REG_PADDING
2576 && (size == UNITS_PER_WORD
2577 || (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2578 != (BYTES_BIG_ENDIAN ? upward : downward)))
2584 /* We are really truncating a word_mode value containing
2585 SIZE bytes into a value of mode MODE. If such an
2586 operation requires no actual instructions, we can refer
2587 to the value directly in mode MODE, otherwise we must
2588 start with the register in word_mode and explicitly
2590 if (TRULY_NOOP_TRUNCATION (size * BITS_PER_UNIT, BITS_PER_WORD))
2591 reg = gen_rtx_REG (mode, REGNO (entry_parm));
2594 reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
2595 reg = convert_to_mode (mode, copy_to_reg (reg), 1);
2597 emit_move_insn (change_address (mem, mode, 0), reg);
2600 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
2601 machine must be aligned to the left before storing
2602 to memory. Note that the previous test doesn't
2603 handle all cases (e.g. SIZE == 3). */
2604 else if (size != UNITS_PER_WORD
2605 #ifdef BLOCK_REG_PADDING
2606 && (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2614 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
2615 rtx reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
2617 x = expand_shift (LSHIFT_EXPR, word_mode, reg,
2618 build_int_cst (NULL_TREE, by),
2620 tem = change_address (mem, word_mode, 0);
2621 emit_move_insn (tem, x);
2624 move_block_from_reg (REGNO (entry_parm), mem,
2625 size_stored / UNITS_PER_WORD);
2628 move_block_from_reg (REGNO (entry_parm), mem,
2629 size_stored / UNITS_PER_WORD);
2631 else if (data->stack_parm == 0)
2633 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2634 emit_block_move (stack_parm, data->entry_parm, GEN_INT (size),
2636 all->first_conversion_insn = get_insns ();
2637 all->last_conversion_insn = get_last_insn ();
2641 data->stack_parm = stack_parm;
2642 SET_DECL_RTL (parm, stack_parm);
2645 /* A subroutine of assign_parms. Allocate a pseudo to hold the current
2646 parameter. Get it there. Perform all ABI specified conversions. */
2649 assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm,
2650 struct assign_parm_data_one *data)
2653 enum machine_mode promoted_nominal_mode;
2654 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (parm));
2655 bool did_conversion = false;
2657 /* Store the parm in a pseudoregister during the function, but we may
2658 need to do it in a wider mode. */
2660 /* This is not really promoting for a call. However we need to be
2661 consistent with assign_parm_find_data_types and expand_expr_real_1. */
2662 promoted_nominal_mode
2663 = promote_mode (data->nominal_type, data->nominal_mode, &unsignedp, 1);
2665 parmreg = gen_reg_rtx (promoted_nominal_mode);
2667 if (!DECL_ARTIFICIAL (parm))
2668 mark_user_reg (parmreg);
2670 /* If this was an item that we received a pointer to,
2671 set DECL_RTL appropriately. */
2672 if (data->passed_pointer)
2674 rtx x = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data->passed_type)), parmreg);
2675 set_mem_attributes (x, parm, 1);
2676 SET_DECL_RTL (parm, x);
2679 SET_DECL_RTL (parm, parmreg);
2681 assign_parm_remove_parallels (data);
2683 /* Copy the value into the register. */
2684 if (data->nominal_mode != data->passed_mode
2685 || promoted_nominal_mode != data->promoted_mode)
2689 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
2690 mode, by the caller. We now have to convert it to
2691 NOMINAL_MODE, if different. However, PARMREG may be in
2692 a different mode than NOMINAL_MODE if it is being stored
2695 If ENTRY_PARM is a hard register, it might be in a register
2696 not valid for operating in its mode (e.g., an odd-numbered
2697 register for a DFmode). In that case, moves are the only
2698 thing valid, so we can't do a convert from there. This
2699 occurs when the calling sequence allow such misaligned
2702 In addition, the conversion may involve a call, which could
2703 clobber parameters which haven't been copied to pseudo
2704 registers yet. Therefore, we must first copy the parm to
2705 a pseudo reg here, and save the conversion until after all
2706 parameters have been moved. */
2708 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
2710 emit_move_insn (tempreg, validize_mem (data->entry_parm));
2712 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2713 tempreg = convert_to_mode (data->nominal_mode, tempreg, unsignedp);
2715 if (GET_CODE (tempreg) == SUBREG
2716 && GET_MODE (tempreg) == data->nominal_mode
2717 && REG_P (SUBREG_REG (tempreg))
2718 && data->nominal_mode == data->passed_mode
2719 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (data->entry_parm)
2720 && GET_MODE_SIZE (GET_MODE (tempreg))
2721 < GET_MODE_SIZE (GET_MODE (data->entry_parm)))
2723 /* The argument is already sign/zero extended, so note it
2725 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
2726 SUBREG_PROMOTED_UNSIGNED_SET (tempreg, unsignedp);
2729 /* TREE_USED gets set erroneously during expand_assignment. */
2730 save_tree_used = TREE_USED (parm);
2731 expand_assignment (parm, make_tree (data->nominal_type, tempreg), false);
2732 TREE_USED (parm) = save_tree_used;
2733 all->first_conversion_insn = get_insns ();
2734 all->last_conversion_insn = get_last_insn ();
2737 did_conversion = true;
2740 emit_move_insn (parmreg, validize_mem (data->entry_parm));
2742 /* If we were passed a pointer but the actual value can safely live
2743 in a register, put it in one. */
2744 if (data->passed_pointer
2745 && TYPE_MODE (TREE_TYPE (parm)) != BLKmode
2746 /* If by-reference argument was promoted, demote it. */
2747 && (TYPE_MODE (TREE_TYPE (parm)) != GET_MODE (DECL_RTL (parm))
2748 || use_register_for_decl (parm)))
2750 /* We can't use nominal_mode, because it will have been set to
2751 Pmode above. We must use the actual mode of the parm. */
2752 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
2753 mark_user_reg (parmreg);
2755 if (GET_MODE (parmreg) != GET_MODE (DECL_RTL (parm)))
2757 rtx tempreg = gen_reg_rtx (GET_MODE (DECL_RTL (parm)));
2758 int unsigned_p = TYPE_UNSIGNED (TREE_TYPE (parm));
2760 push_to_sequence2 (all->first_conversion_insn,
2761 all->last_conversion_insn);
2762 emit_move_insn (tempreg, DECL_RTL (parm));
2763 tempreg = convert_to_mode (GET_MODE (parmreg), tempreg, unsigned_p);
2764 emit_move_insn (parmreg, tempreg);
2765 all->first_conversion_insn = get_insns ();
2766 all->last_conversion_insn = get_last_insn ();
2769 did_conversion = true;
2772 emit_move_insn (parmreg, DECL_RTL (parm));
2774 SET_DECL_RTL (parm, parmreg);
2776 /* STACK_PARM is the pointer, not the parm, and PARMREG is
2778 data->stack_parm = NULL;
2781 /* Mark the register as eliminable if we did no conversion and it was
2782 copied from memory at a fixed offset, and the arg pointer was not
2783 copied to a pseudo-reg. If the arg pointer is a pseudo reg or the
2784 offset formed an invalid address, such memory-equivalences as we
2785 make here would screw up life analysis for it. */
2786 if (data->nominal_mode == data->passed_mode
2788 && data->stack_parm != 0
2789 && MEM_P (data->stack_parm)
2790 && data->locate.offset.var == 0
2791 && reg_mentioned_p (virtual_incoming_args_rtx,
2792 XEXP (data->stack_parm, 0)))
2794 rtx linsn = get_last_insn ();
2797 /* Mark complex types separately. */
2798 if (GET_CODE (parmreg) == CONCAT)
2800 enum machine_mode submode
2801 = GET_MODE_INNER (GET_MODE (parmreg));
2802 int regnor = REGNO (XEXP (parmreg, 0));
2803 int regnoi = REGNO (XEXP (parmreg, 1));
2804 rtx stackr = adjust_address_nv (data->stack_parm, submode, 0);
2805 rtx stacki = adjust_address_nv (data->stack_parm, submode,
2806 GET_MODE_SIZE (submode));
2808 /* Scan backwards for the set of the real and
2810 for (sinsn = linsn; sinsn != 0;
2811 sinsn = prev_nonnote_insn (sinsn))
2813 set = single_set (sinsn);
2817 if (SET_DEST (set) == regno_reg_rtx [regnoi])
2818 set_unique_reg_note (sinsn, REG_EQUIV, stacki);
2819 else if (SET_DEST (set) == regno_reg_rtx [regnor])
2820 set_unique_reg_note (sinsn, REG_EQUIV, stackr);
2823 else if ((set = single_set (linsn)) != 0
2824 && SET_DEST (set) == parmreg)
2825 set_unique_reg_note (linsn, REG_EQUIV, data->stack_parm);
2828 /* For pointer data type, suggest pointer register. */
2829 if (POINTER_TYPE_P (TREE_TYPE (parm)))
2830 mark_reg_pointer (parmreg,
2831 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
2834 /* A subroutine of assign_parms. Allocate stack space to hold the current
2835 parameter. Get it there. Perform all ABI specified conversions. */
2838 assign_parm_setup_stack (struct assign_parm_data_all *all, tree parm,
2839 struct assign_parm_data_one *data)
2841 /* Value must be stored in the stack slot STACK_PARM during function
2843 bool to_conversion = false;
2845 assign_parm_remove_parallels (data);
2847 if (data->promoted_mode != data->nominal_mode)
2849 /* Conversion is required. */
2850 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
2852 emit_move_insn (tempreg, validize_mem (data->entry_parm));
2854 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2855 to_conversion = true;
2857 data->entry_parm = convert_to_mode (data->nominal_mode, tempreg,
2858 TYPE_UNSIGNED (TREE_TYPE (parm)));
2860 if (data->stack_parm)
2861 /* ??? This may need a big-endian conversion on sparc64. */
2863 = adjust_address (data->stack_parm, data->nominal_mode, 0);
2866 if (data->entry_parm != data->stack_parm)
2870 if (data->stack_parm == 0)
2873 = assign_stack_local (GET_MODE (data->entry_parm),
2874 GET_MODE_SIZE (GET_MODE (data->entry_parm)),
2875 TYPE_ALIGN (data->passed_type));
2876 set_mem_attributes (data->stack_parm, parm, 1);
2879 dest = validize_mem (data->stack_parm);
2880 src = validize_mem (data->entry_parm);
2884 /* Use a block move to handle potentially misaligned entry_parm. */
2886 push_to_sequence2 (all->first_conversion_insn,
2887 all->last_conversion_insn);
2888 to_conversion = true;
2890 emit_block_move (dest, src,
2891 GEN_INT (int_size_in_bytes (data->passed_type)),
2895 emit_move_insn (dest, src);
2900 all->first_conversion_insn = get_insns ();
2901 all->last_conversion_insn = get_last_insn ();
2905 SET_DECL_RTL (parm, data->stack_parm);
2908 /* A subroutine of assign_parms. If the ABI splits complex arguments, then
2909 undo the frobbing that we did in assign_parms_augmented_arg_list. */
2912 assign_parms_unsplit_complex (struct assign_parm_data_all *all, tree fnargs)
2915 tree orig_fnargs = all->orig_fnargs;
2917 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm))
2919 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
2920 && targetm.calls.split_complex_arg (TREE_TYPE (parm)))
2922 rtx tmp, real, imag;
2923 enum machine_mode inner = GET_MODE_INNER (DECL_MODE (parm));
2925 real = DECL_RTL (fnargs);
2926 imag = DECL_RTL (TREE_CHAIN (fnargs));
2927 if (inner != GET_MODE (real))
2929 real = gen_lowpart_SUBREG (inner, real);
2930 imag = gen_lowpart_SUBREG (inner, imag);
2933 if (TREE_ADDRESSABLE (parm))
2936 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (parm));
2938 /* split_complex_arg put the real and imag parts in
2939 pseudos. Move them to memory. */
2940 tmp = assign_stack_local (DECL_MODE (parm), size,
2941 TYPE_ALIGN (TREE_TYPE (parm)));
2942 set_mem_attributes (tmp, parm, 1);
2943 rmem = adjust_address_nv (tmp, inner, 0);
2944 imem = adjust_address_nv (tmp, inner, GET_MODE_SIZE (inner));
2945 push_to_sequence2 (all->first_conversion_insn,
2946 all->last_conversion_insn);
2947 emit_move_insn (rmem, real);
2948 emit_move_insn (imem, imag);
2949 all->first_conversion_insn = get_insns ();
2950 all->last_conversion_insn = get_last_insn ();
2954 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
2955 SET_DECL_RTL (parm, tmp);
2957 real = DECL_INCOMING_RTL (fnargs);
2958 imag = DECL_INCOMING_RTL (TREE_CHAIN (fnargs));
2959 if (inner != GET_MODE (real))
2961 real = gen_lowpart_SUBREG (inner, real);
2962 imag = gen_lowpart_SUBREG (inner, imag);
2964 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
2965 set_decl_incoming_rtl (parm, tmp, false);
2966 fnargs = TREE_CHAIN (fnargs);
2970 SET_DECL_RTL (parm, DECL_RTL (fnargs));
2971 set_decl_incoming_rtl (parm, DECL_INCOMING_RTL (fnargs), false);
2973 /* Set MEM_EXPR to the original decl, i.e. to PARM,
2974 instead of the copy of decl, i.e. FNARGS. */
2975 if (DECL_INCOMING_RTL (parm) && MEM_P (DECL_INCOMING_RTL (parm)))
2976 set_mem_expr (DECL_INCOMING_RTL (parm), parm);
2979 fnargs = TREE_CHAIN (fnargs);
2983 /* Assign RTL expressions to the function's parameters. This may involve
2984 copying them into registers and using those registers as the DECL_RTL. */
2987 assign_parms (tree fndecl)
2989 struct assign_parm_data_all all;
2992 crtl->args.internal_arg_pointer
2993 = targetm.calls.internal_arg_pointer ();
2995 assign_parms_initialize_all (&all);
2996 fnargs = assign_parms_augmented_arg_list (&all);
2998 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
3000 struct assign_parm_data_one data;
3002 /* Extract the type of PARM; adjust it according to ABI. */
3003 assign_parm_find_data_types (&all, parm, &data);
3005 /* Early out for errors and void parameters. */
3006 if (data.passed_mode == VOIDmode)
3008 SET_DECL_RTL (parm, const0_rtx);
3009 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
3013 /* Estimate stack alignment from parameter alignment. */
3014 if (SUPPORTS_STACK_ALIGNMENT)
3016 unsigned int align = FUNCTION_ARG_BOUNDARY (data.promoted_mode,
3018 if (TYPE_ALIGN (data.nominal_type) > align)
3019 align = TYPE_ALIGN (data.passed_type);
3020 if (crtl->stack_alignment_estimated < align)
3022 gcc_assert (!crtl->stack_realign_processed);
3023 crtl->stack_alignment_estimated = align;
3027 if (cfun->stdarg && !TREE_CHAIN (parm))
3028 assign_parms_setup_varargs (&all, &data, false);
3030 /* Find out where the parameter arrives in this function. */
3031 assign_parm_find_entry_rtl (&all, &data);
3033 /* Find out where stack space for this parameter might be. */
3034 if (assign_parm_is_stack_parm (&all, &data))
3036 assign_parm_find_stack_rtl (parm, &data);
3037 assign_parm_adjust_entry_rtl (&data);
3040 /* Record permanently how this parm was passed. */
3041 set_decl_incoming_rtl (parm, data.entry_parm, data.passed_pointer);
3043 /* Update info on where next arg arrives in registers. */
3044 FUNCTION_ARG_ADVANCE (all.args_so_far, data.promoted_mode,
3045 data.passed_type, data.named_arg);
3047 assign_parm_adjust_stack_rtl (&data);
3049 if (assign_parm_setup_block_p (&data))
3050 assign_parm_setup_block (&all, parm, &data);
3051 else if (data.passed_pointer || use_register_for_decl (parm))
3052 assign_parm_setup_reg (&all, parm, &data);
3054 assign_parm_setup_stack (&all, parm, &data);
3057 if (targetm.calls.split_complex_arg && fnargs != all.orig_fnargs)
3058 assign_parms_unsplit_complex (&all, fnargs);
3060 /* Output all parameter conversion instructions (possibly including calls)
3061 now that all parameters have been copied out of hard registers. */
3062 emit_insn (all.first_conversion_insn);
3064 /* Estimate reload stack alignment from scalar return mode. */
3065 if (SUPPORTS_STACK_ALIGNMENT)
3067 if (DECL_RESULT (fndecl))
3069 tree type = TREE_TYPE (DECL_RESULT (fndecl));
3070 enum machine_mode mode = TYPE_MODE (type);
3074 && !AGGREGATE_TYPE_P (type))
3076 unsigned int align = GET_MODE_ALIGNMENT (mode);
3077 if (crtl->stack_alignment_estimated < align)
3079 gcc_assert (!crtl->stack_realign_processed);
3080 crtl->stack_alignment_estimated = align;
3086 /* If we are receiving a struct value address as the first argument, set up
3087 the RTL for the function result. As this might require code to convert
3088 the transmitted address to Pmode, we do this here to ensure that possible
3089 preliminary conversions of the address have been emitted already. */
3090 if (all.function_result_decl)
3092 tree result = DECL_RESULT (current_function_decl);
3093 rtx addr = DECL_RTL (all.function_result_decl);
3096 if (DECL_BY_REFERENCE (result))
3100 addr = convert_memory_address (Pmode, addr);
3101 x = gen_rtx_MEM (DECL_MODE (result), addr);
3102 set_mem_attributes (x, result, 1);
3104 SET_DECL_RTL (result, x);
3107 /* We have aligned all the args, so add space for the pretend args. */
3108 crtl->args.pretend_args_size = all.pretend_args_size;
3109 all.stack_args_size.constant += all.extra_pretend_bytes;
3110 crtl->args.size = all.stack_args_size.constant;
3112 /* Adjust function incoming argument size for alignment and
3115 #ifdef REG_PARM_STACK_SPACE
3116 crtl->args.size = MAX (crtl->args.size,
3117 REG_PARM_STACK_SPACE (fndecl));
3120 crtl->args.size = CEIL_ROUND (crtl->args.size,
3121 PARM_BOUNDARY / BITS_PER_UNIT);
3123 #ifdef ARGS_GROW_DOWNWARD
3124 crtl->args.arg_offset_rtx
3125 = (all.stack_args_size.var == 0 ? GEN_INT (-all.stack_args_size.constant)
3126 : expand_expr (size_diffop (all.stack_args_size.var,
3127 size_int (-all.stack_args_size.constant)),
3128 NULL_RTX, VOIDmode, 0));
3130 crtl->args.arg_offset_rtx = ARGS_SIZE_RTX (all.stack_args_size);
3133 /* See how many bytes, if any, of its args a function should try to pop
3136 crtl->args.pops_args = RETURN_POPS_ARGS (fndecl, TREE_TYPE (fndecl),
3139 /* For stdarg.h function, save info about
3140 regs and stack space used by the named args. */
3142 crtl->args.info = all.args_so_far;
3144 /* Set the rtx used for the function return value. Put this in its
3145 own variable so any optimizers that need this information don't have
3146 to include tree.h. Do this here so it gets done when an inlined
3147 function gets output. */
3150 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
3151 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
3153 /* If scalar return value was computed in a pseudo-reg, or was a named
3154 return value that got dumped to the stack, copy that to the hard
3156 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
3158 tree decl_result = DECL_RESULT (fndecl);
3159 rtx decl_rtl = DECL_RTL (decl_result);
3161 if (REG_P (decl_rtl)
3162 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
3163 : DECL_REGISTER (decl_result))
3167 real_decl_rtl = targetm.calls.function_value (TREE_TYPE (decl_result),
3169 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
3170 /* The delay slot scheduler assumes that crtl->return_rtx
3171 holds the hard register containing the return value, not a
3172 temporary pseudo. */
3173 crtl->return_rtx = real_decl_rtl;
3178 /* A subroutine of gimplify_parameters, invoked via walk_tree.
3179 For all seen types, gimplify their sizes. */
3182 gimplify_parm_type (tree *tp, int *walk_subtrees, void *data)
3189 if (POINTER_TYPE_P (t))
3191 else if (TYPE_SIZE (t) && !TREE_CONSTANT (TYPE_SIZE (t))
3192 && !TYPE_SIZES_GIMPLIFIED (t))
3194 gimplify_type_sizes (t, (gimple_seq *) data);
3202 /* Gimplify the parameter list for current_function_decl. This involves
3203 evaluating SAVE_EXPRs of variable sized parameters and generating code
3204 to implement callee-copies reference parameters. Returns a sequence of
3205 statements to add to the beginning of the function. */
3208 gimplify_parameters (void)
3210 struct assign_parm_data_all all;
3212 gimple_seq stmts = NULL;
3214 assign_parms_initialize_all (&all);
3215 fnargs = assign_parms_augmented_arg_list (&all);
3217 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
3219 struct assign_parm_data_one data;
3221 /* Extract the type of PARM; adjust it according to ABI. */
3222 assign_parm_find_data_types (&all, parm, &data);
3224 /* Early out for errors and void parameters. */
3225 if (data.passed_mode == VOIDmode || DECL_SIZE (parm) == NULL)
3228 /* Update info on where next arg arrives in registers. */
3229 FUNCTION_ARG_ADVANCE (all.args_so_far, data.promoted_mode,
3230 data.passed_type, data.named_arg);
3232 /* ??? Once upon a time variable_size stuffed parameter list
3233 SAVE_EXPRs (amongst others) onto a pending sizes list. This
3234 turned out to be less than manageable in the gimple world.
3235 Now we have to hunt them down ourselves. */
3236 walk_tree_without_duplicates (&data.passed_type,
3237 gimplify_parm_type, &stmts);
3239 if (TREE_CODE (DECL_SIZE_UNIT (parm)) != INTEGER_CST)
3241 gimplify_one_sizepos (&DECL_SIZE (parm), &stmts);
3242 gimplify_one_sizepos (&DECL_SIZE_UNIT (parm), &stmts);
3245 if (data.passed_pointer)
3247 tree type = TREE_TYPE (data.passed_type);
3248 if (reference_callee_copied (&all.args_so_far, TYPE_MODE (type),
3249 type, data.named_arg))
3253 /* For constant-sized objects, this is trivial; for
3254 variable-sized objects, we have to play games. */
3255 if (TREE_CODE (DECL_SIZE_UNIT (parm)) == INTEGER_CST
3256 && !(flag_stack_check == GENERIC_STACK_CHECK
3257 && compare_tree_int (DECL_SIZE_UNIT (parm),
3258 STACK_CHECK_MAX_VAR_SIZE) > 0))
3260 local = create_tmp_var (type, get_name (parm));
3261 DECL_IGNORED_P (local) = 0;
3265 tree ptr_type, addr;
3267 ptr_type = build_pointer_type (type);
3268 addr = create_tmp_var (ptr_type, get_name (parm));
3269 DECL_IGNORED_P (addr) = 0;
3270 local = build_fold_indirect_ref (addr);
3272 t = built_in_decls[BUILT_IN_ALLOCA];
3273 t = build_call_expr (t, 1, DECL_SIZE_UNIT (parm));
3274 t = fold_convert (ptr_type, t);
3275 t = build2 (MODIFY_EXPR, TREE_TYPE (addr), addr, t);
3276 gimplify_and_add (t, &stmts);
3279 gimplify_assign (local, parm, &stmts);
3281 SET_DECL_VALUE_EXPR (parm, local);
3282 DECL_HAS_VALUE_EXPR_P (parm) = 1;
3290 /* Compute the size and offset from the start of the stacked arguments for a
3291 parm passed in mode PASSED_MODE and with type TYPE.
3293 INITIAL_OFFSET_PTR points to the current offset into the stacked
3296 The starting offset and size for this parm are returned in
3297 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
3298 nonzero, the offset is that of stack slot, which is returned in
3299 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
3300 padding required from the initial offset ptr to the stack slot.
3302 IN_REGS is nonzero if the argument will be passed in registers. It will
3303 never be set if REG_PARM_STACK_SPACE is not defined.
3305 FNDECL is the function in which the argument was defined.
3307 There are two types of rounding that are done. The first, controlled by
3308 FUNCTION_ARG_BOUNDARY, forces the offset from the start of the argument
3309 list to be aligned to the specific boundary (in bits). This rounding
3310 affects the initial and starting offsets, but not the argument size.
3312 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
3313 optionally rounds the size of the parm to PARM_BOUNDARY. The
3314 initial offset is not affected by this rounding, while the size always
3315 is and the starting offset may be. */
3317 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
3318 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
3319 callers pass in the total size of args so far as
3320 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
3323 locate_and_pad_parm (enum machine_mode passed_mode, tree type, int in_regs,
3324 int partial, tree fndecl ATTRIBUTE_UNUSED,
3325 struct args_size *initial_offset_ptr,
3326 struct locate_and_pad_arg_data *locate)
3329 enum direction where_pad;
3330 unsigned int boundary;
3331 int reg_parm_stack_space = 0;
3332 int part_size_in_regs;
3334 #ifdef REG_PARM_STACK_SPACE
3335 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
3337 /* If we have found a stack parm before we reach the end of the
3338 area reserved for registers, skip that area. */
3341 if (reg_parm_stack_space > 0)
3343 if (initial_offset_ptr->var)
3345 initial_offset_ptr->var
3346 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
3347 ssize_int (reg_parm_stack_space));
3348 initial_offset_ptr->constant = 0;
3350 else if (initial_offset_ptr->constant < reg_parm_stack_space)
3351 initial_offset_ptr->constant = reg_parm_stack_space;
3354 #endif /* REG_PARM_STACK_SPACE */
3356 part_size_in_regs = (reg_parm_stack_space == 0 ? partial : 0);
3359 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
3360 where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
3361 boundary = FUNCTION_ARG_BOUNDARY (passed_mode, type);
3362 locate->where_pad = where_pad;
3364 /* Alignment can't exceed MAX_SUPPORTED_STACK_ALIGNMENT. */
3365 if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
3366 boundary = MAX_SUPPORTED_STACK_ALIGNMENT;
3368 locate->boundary = boundary;
3370 if (SUPPORTS_STACK_ALIGNMENT)
3372 /* stack_alignment_estimated can't change after stack has been
3374 if (crtl->stack_alignment_estimated < boundary)
3376 if (!crtl->stack_realign_processed)
3377 crtl->stack_alignment_estimated = boundary;
3380 /* If stack is realigned and stack alignment value
3381 hasn't been finalized, it is OK not to increase
3382 stack_alignment_estimated. The bigger alignment
3383 requirement is recorded in stack_alignment_needed
3385 gcc_assert (!crtl->stack_realign_finalized
3386 && crtl->stack_realign_needed);
3391 /* Remember if the outgoing parameter requires extra alignment on the
3392 calling function side. */
3393 if (crtl->stack_alignment_needed < boundary)
3394 crtl->stack_alignment_needed = boundary;
3395 if (crtl->max_used_stack_slot_alignment < crtl->stack_alignment_needed)
3396 crtl->max_used_stack_slot_alignment = crtl->stack_alignment_needed;
3397 if (crtl->preferred_stack_boundary < boundary)
3398 crtl->preferred_stack_boundary = boundary;
3400 #ifdef ARGS_GROW_DOWNWARD
3401 locate->slot_offset.constant = -initial_offset_ptr->constant;
3402 if (initial_offset_ptr->var)
3403 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
3404 initial_offset_ptr->var);
3408 if (where_pad != none
3409 && (!host_integerp (sizetree, 1)
3410 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
3411 s2 = round_up (s2, PARM_BOUNDARY / BITS_PER_UNIT);
3412 SUB_PARM_SIZE (locate->slot_offset, s2);
3415 locate->slot_offset.constant += part_size_in_regs;
3418 #ifdef REG_PARM_STACK_SPACE
3419 || REG_PARM_STACK_SPACE (fndecl) > 0
3422 pad_to_arg_alignment (&locate->slot_offset, boundary,
3423 &locate->alignment_pad);
3425 locate->size.constant = (-initial_offset_ptr->constant
3426 - locate->slot_offset.constant);
3427 if (initial_offset_ptr->var)
3428 locate->size.var = size_binop (MINUS_EXPR,
3429 size_binop (MINUS_EXPR,
3431 initial_offset_ptr->var),
3432 locate->slot_offset.var);
3434 /* Pad_below needs the pre-rounded size to know how much to pad
3436 locate->offset = locate->slot_offset;
3437 if (where_pad == downward)
3438 pad_below (&locate->offset, passed_mode, sizetree);
3440 #else /* !ARGS_GROW_DOWNWARD */
3442 #ifdef REG_PARM_STACK_SPACE
3443 || REG_PARM_STACK_SPACE (fndecl) > 0
3446 pad_to_arg_alignment (initial_offset_ptr, boundary,
3447 &locate->alignment_pad);
3448 locate->slot_offset = *initial_offset_ptr;
3450 #ifdef PUSH_ROUNDING
3451 if (passed_mode != BLKmode)
3452 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
3455 /* Pad_below needs the pre-rounded size to know how much to pad below
3456 so this must be done before rounding up. */
3457 locate->offset = locate->slot_offset;
3458 if (where_pad == downward)
3459 pad_below (&locate->offset, passed_mode, sizetree);
3461 if (where_pad != none
3462 && (!host_integerp (sizetree, 1)
3463 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
3464 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3466 ADD_PARM_SIZE (locate->size, sizetree);
3468 locate->size.constant -= part_size_in_regs;
3469 #endif /* ARGS_GROW_DOWNWARD */
3472 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
3473 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
3476 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
3477 struct args_size *alignment_pad)
3479 tree save_var = NULL_TREE;
3480 HOST_WIDE_INT save_constant = 0;
3481 int boundary_in_bytes = boundary / BITS_PER_UNIT;
3482 HOST_WIDE_INT sp_offset = STACK_POINTER_OFFSET;
3484 #ifdef SPARC_STACK_BOUNDARY_HACK
3485 /* ??? The SPARC port may claim a STACK_BOUNDARY higher than
3486 the real alignment of %sp. However, when it does this, the
3487 alignment of %sp+STACK_POINTER_OFFSET is STACK_BOUNDARY. */
3488 if (SPARC_STACK_BOUNDARY_HACK)
3492 if (boundary > PARM_BOUNDARY)
3494 save_var = offset_ptr->var;
3495 save_constant = offset_ptr->constant;
3498 alignment_pad->var = NULL_TREE;
3499 alignment_pad->constant = 0;
3501 if (boundary > BITS_PER_UNIT)
3503 if (offset_ptr->var)
3505 tree sp_offset_tree = ssize_int (sp_offset);
3506 tree offset = size_binop (PLUS_EXPR,
3507 ARGS_SIZE_TREE (*offset_ptr),
3509 #ifdef ARGS_GROW_DOWNWARD
3510 tree rounded = round_down (offset, boundary / BITS_PER_UNIT);
3512 tree rounded = round_up (offset, boundary / BITS_PER_UNIT);
3515 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
3516 /* ARGS_SIZE_TREE includes constant term. */
3517 offset_ptr->constant = 0;
3518 if (boundary > PARM_BOUNDARY)
3519 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
3524 offset_ptr->constant = -sp_offset +
3525 #ifdef ARGS_GROW_DOWNWARD
3526 FLOOR_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
3528 CEIL_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
3530 if (boundary > PARM_BOUNDARY)
3531 alignment_pad->constant = offset_ptr->constant - save_constant;
3537 pad_below (struct args_size *offset_ptr, enum machine_mode passed_mode, tree sizetree)
3539 if (passed_mode != BLKmode)
3541 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
3542 offset_ptr->constant
3543 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
3544 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
3545 - GET_MODE_SIZE (passed_mode));
3549 if (TREE_CODE (sizetree) != INTEGER_CST
3550 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
3552 /* Round the size up to multiple of PARM_BOUNDARY bits. */
3553 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3555 ADD_PARM_SIZE (*offset_ptr, s2);
3556 SUB_PARM_SIZE (*offset_ptr, sizetree);
3562 /* True if register REGNO was alive at a place where `setjmp' was
3563 called and was set more than once or is an argument. Such regs may
3564 be clobbered by `longjmp'. */
3567 regno_clobbered_at_setjmp (bitmap setjmp_crosses, int regno)
3569 /* There appear to be cases where some local vars never reach the
3570 backend but have bogus regnos. */
3571 if (regno >= max_reg_num ())
3574 return ((REG_N_SETS (regno) > 1
3575 || REGNO_REG_SET_P (df_get_live_out (ENTRY_BLOCK_PTR), regno))
3576 && REGNO_REG_SET_P (setjmp_crosses, regno));
3579 /* Walk the tree of blocks describing the binding levels within a
3580 function and warn about variables the might be killed by setjmp or
3581 vfork. This is done after calling flow_analysis before register
3582 allocation since that will clobber the pseudo-regs to hard
3586 setjmp_vars_warning (bitmap setjmp_crosses, tree block)
3590 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
3592 if (TREE_CODE (decl) == VAR_DECL
3593 && DECL_RTL_SET_P (decl)
3594 && REG_P (DECL_RTL (decl))
3595 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
3596 warning (OPT_Wclobbered, "variable %q+D might be clobbered by"
3597 " %<longjmp%> or %<vfork%>", decl);
3600 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = BLOCK_CHAIN (sub))
3601 setjmp_vars_warning (setjmp_crosses, sub);
3604 /* Do the appropriate part of setjmp_vars_warning
3605 but for arguments instead of local variables. */
3608 setjmp_args_warning (bitmap setjmp_crosses)
3611 for (decl = DECL_ARGUMENTS (current_function_decl);
3612 decl; decl = TREE_CHAIN (decl))
3613 if (DECL_RTL (decl) != 0
3614 && REG_P (DECL_RTL (decl))
3615 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
3616 warning (OPT_Wclobbered,
3617 "argument %q+D might be clobbered by %<longjmp%> or %<vfork%>",
3621 /* Generate warning messages for variables live across setjmp. */
3624 generate_setjmp_warnings (void)
3626 bitmap setjmp_crosses = regstat_get_setjmp_crosses ();
3628 if (n_basic_blocks == NUM_FIXED_BLOCKS
3629 || bitmap_empty_p (setjmp_crosses))
3632 setjmp_vars_warning (setjmp_crosses, DECL_INITIAL (current_function_decl));
3633 setjmp_args_warning (setjmp_crosses);
3637 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
3638 and create duplicate blocks. */
3639 /* ??? Need an option to either create block fragments or to create
3640 abstract origin duplicates of a source block. It really depends
3641 on what optimization has been performed. */
3644 reorder_blocks (void)
3646 tree block = DECL_INITIAL (current_function_decl);
3647 VEC(tree,heap) *block_stack;
3649 if (block == NULL_TREE)
3652 block_stack = VEC_alloc (tree, heap, 10);
3654 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
3655 clear_block_marks (block);
3657 /* Prune the old trees away, so that they don't get in the way. */
3658 BLOCK_SUBBLOCKS (block) = NULL_TREE;
3659 BLOCK_CHAIN (block) = NULL_TREE;
3661 /* Recreate the block tree from the note nesting. */
3662 reorder_blocks_1 (get_insns (), block, &block_stack);
3663 BLOCK_SUBBLOCKS (block) = blocks_nreverse (BLOCK_SUBBLOCKS (block));
3665 VEC_free (tree, heap, block_stack);
3668 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
3671 clear_block_marks (tree block)
3675 TREE_ASM_WRITTEN (block) = 0;
3676 clear_block_marks (BLOCK_SUBBLOCKS (block));
3677 block = BLOCK_CHAIN (block);
3682 reorder_blocks_1 (rtx insns, tree current_block, VEC(tree,heap) **p_block_stack)
3686 for (insn = insns; insn; insn = NEXT_INSN (insn))
3690 if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_BEG)
3692 tree block = NOTE_BLOCK (insn);
3695 origin = (BLOCK_FRAGMENT_ORIGIN (block)
3696 ? BLOCK_FRAGMENT_ORIGIN (block)
3699 /* If we have seen this block before, that means it now
3700 spans multiple address regions. Create a new fragment. */
3701 if (TREE_ASM_WRITTEN (block))
3703 tree new_block = copy_node (block);
3705 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
3706 BLOCK_FRAGMENT_CHAIN (new_block)
3707 = BLOCK_FRAGMENT_CHAIN (origin);
3708 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
3710 NOTE_BLOCK (insn) = new_block;
3714 BLOCK_SUBBLOCKS (block) = 0;
3715 TREE_ASM_WRITTEN (block) = 1;
3716 /* When there's only one block for the entire function,
3717 current_block == block and we mustn't do this, it
3718 will cause infinite recursion. */
3719 if (block != current_block)
3721 if (block != origin)
3722 gcc_assert (BLOCK_SUPERCONTEXT (origin) == current_block);
3724 BLOCK_SUPERCONTEXT (block) = current_block;
3725 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
3726 BLOCK_SUBBLOCKS (current_block) = block;
3727 current_block = origin;
3729 VEC_safe_push (tree, heap, *p_block_stack, block);
3731 else if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_END)
3733 NOTE_BLOCK (insn) = VEC_pop (tree, *p_block_stack);
3734 BLOCK_SUBBLOCKS (current_block)
3735 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block));
3736 current_block = BLOCK_SUPERCONTEXT (current_block);
3742 /* Reverse the order of elements in the chain T of blocks,
3743 and return the new head of the chain (old last element). */
3746 blocks_nreverse (tree t)
3748 tree prev = 0, decl, next;
3749 for (decl = t; decl; decl = next)
3751 next = BLOCK_CHAIN (decl);
3752 BLOCK_CHAIN (decl) = prev;
3758 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
3759 non-NULL, list them all into VECTOR, in a depth-first preorder
3760 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
3764 all_blocks (tree block, tree *vector)
3770 TREE_ASM_WRITTEN (block) = 0;
3772 /* Record this block. */
3774 vector[n_blocks] = block;
3778 /* Record the subblocks, and their subblocks... */
3779 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
3780 vector ? vector + n_blocks : 0);
3781 block = BLOCK_CHAIN (block);
3787 /* Return a vector containing all the blocks rooted at BLOCK. The
3788 number of elements in the vector is stored in N_BLOCKS_P. The
3789 vector is dynamically allocated; it is the caller's responsibility
3790 to call `free' on the pointer returned. */
3793 get_block_vector (tree block, int *n_blocks_p)
3797 *n_blocks_p = all_blocks (block, NULL);
3798 block_vector = XNEWVEC (tree, *n_blocks_p);
3799 all_blocks (block, block_vector);
3801 return block_vector;
3804 static GTY(()) int next_block_index = 2;
3806 /* Set BLOCK_NUMBER for all the blocks in FN. */
3809 number_blocks (tree fn)
3815 /* For SDB and XCOFF debugging output, we start numbering the blocks
3816 from 1 within each function, rather than keeping a running
3818 #if defined (SDB_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
3819 if (write_symbols == SDB_DEBUG || write_symbols == XCOFF_DEBUG)
3820 next_block_index = 1;
3823 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
3825 /* The top-level BLOCK isn't numbered at all. */
3826 for (i = 1; i < n_blocks; ++i)
3827 /* We number the blocks from two. */
3828 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
3830 free (block_vector);
3835 /* If VAR is present in a subblock of BLOCK, return the subblock. */
3838 debug_find_var_in_block_tree (tree var, tree block)
3842 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
3846 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
3848 tree ret = debug_find_var_in_block_tree (var, t);
3856 /* Keep track of whether we're in a dummy function context. If we are,
3857 we don't want to invoke the set_current_function hook, because we'll
3858 get into trouble if the hook calls target_reinit () recursively or
3859 when the initial initialization is not yet complete. */
3861 static bool in_dummy_function;
3863 /* Invoke the target hook when setting cfun. Update the optimization options
3864 if the function uses different options than the default. */
3867 invoke_set_current_function_hook (tree fndecl)
3869 if (!in_dummy_function)
3871 tree opts = ((fndecl)
3872 ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (fndecl)
3873 : optimization_default_node);
3876 opts = optimization_default_node;
3878 /* Change optimization options if needed. */
3879 if (optimization_current_node != opts)
3881 optimization_current_node = opts;
3882 cl_optimization_restore (TREE_OPTIMIZATION (opts));
3885 targetm.set_current_function (fndecl);
3889 /* cfun should never be set directly; use this function. */
3892 set_cfun (struct function *new_cfun)
3894 if (cfun != new_cfun)
3897 invoke_set_current_function_hook (new_cfun ? new_cfun->decl : NULL_TREE);
3901 /* Keep track of the cfun stack. */
3903 typedef struct function *function_p;
3905 DEF_VEC_P(function_p);
3906 DEF_VEC_ALLOC_P(function_p,heap);
3908 /* Initialized with NOGC, making this poisonous to the garbage collector. */
3910 static VEC(function_p,heap) *cfun_stack;
3912 /* Push the current cfun onto the stack, and set cfun to new_cfun. */
3915 push_cfun (struct function *new_cfun)
3917 VEC_safe_push (function_p, heap, cfun_stack, cfun);
3918 set_cfun (new_cfun);
3921 /* Pop cfun from the stack. */
3926 struct function *new_cfun = VEC_pop (function_p, cfun_stack);
3927 set_cfun (new_cfun);
3930 /* Return value of funcdef and increase it. */
3932 get_next_funcdef_no (void)
3934 return funcdef_no++;
3937 /* Allocate a function structure for FNDECL and set its contents
3938 to the defaults. Set cfun to the newly-allocated object.
3939 Some of the helper functions invoked during initialization assume
3940 that cfun has already been set. Therefore, assign the new object
3941 directly into cfun and invoke the back end hook explicitly at the
3942 very end, rather than initializing a temporary and calling set_cfun
3945 ABSTRACT_P is true if this is a function that will never be seen by
3946 the middle-end. Such functions are front-end concepts (like C++
3947 function templates) that do not correspond directly to functions
3948 placed in object files. */
3951 allocate_struct_function (tree fndecl, bool abstract_p)
3954 tree fntype = fndecl ? TREE_TYPE (fndecl) : NULL_TREE;
3956 cfun = GGC_CNEW (struct function);
3958 cfun->function_frequency = FUNCTION_FREQUENCY_NORMAL;
3960 init_eh_for_function ();
3962 if (init_machine_status)
3963 cfun->machine = (*init_machine_status) ();
3965 #ifdef OVERRIDE_ABI_FORMAT
3966 OVERRIDE_ABI_FORMAT (fndecl);
3969 if (fndecl != NULL_TREE)
3971 DECL_STRUCT_FUNCTION (fndecl) = cfun;
3972 cfun->decl = fndecl;
3973 current_function_funcdef_no = get_next_funcdef_no ();
3975 result = DECL_RESULT (fndecl);
3976 if (!abstract_p && aggregate_value_p (result, fndecl))
3978 #ifdef PCC_STATIC_STRUCT_RETURN
3979 cfun->returns_pcc_struct = 1;
3981 cfun->returns_struct = 1;
3986 && TYPE_ARG_TYPES (fntype) != 0
3987 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
3988 != void_type_node));
3990 /* Assume all registers in stdarg functions need to be saved. */
3991 cfun->va_list_gpr_size = VA_LIST_MAX_GPR_SIZE;
3992 cfun->va_list_fpr_size = VA_LIST_MAX_FPR_SIZE;
3995 invoke_set_current_function_hook (fndecl);
3998 /* This is like allocate_struct_function, but pushes a new cfun for FNDECL
3999 instead of just setting it. */
4002 push_struct_function (tree fndecl)
4004 VEC_safe_push (function_p, heap, cfun_stack, cfun);
4005 allocate_struct_function (fndecl, false);
4008 /* Reset cfun, and other non-struct-function variables to defaults as
4009 appropriate for emitting rtl at the start of a function. */
4012 prepare_function_start (void)
4014 gcc_assert (!crtl->emit.x_last_insn);
4016 init_varasm_status ();
4018 default_rtl_profile ();
4020 cse_not_expected = ! optimize;
4022 /* Caller save not needed yet. */
4023 caller_save_needed = 0;
4025 /* We haven't done register allocation yet. */
4028 /* Indicate that we have not instantiated virtual registers yet. */
4029 virtuals_instantiated = 0;
4031 /* Indicate that we want CONCATs now. */
4032 generating_concat_p = 1;
4034 /* Indicate we have no need of a frame pointer yet. */
4035 frame_pointer_needed = 0;
4038 /* Initialize the rtl expansion mechanism so that we can do simple things
4039 like generate sequences. This is used to provide a context during global
4040 initialization of some passes. You must call expand_dummy_function_end
4041 to exit this context. */
4044 init_dummy_function_start (void)
4046 gcc_assert (!in_dummy_function);
4047 in_dummy_function = true;
4048 push_struct_function (NULL_TREE);
4049 prepare_function_start ();
4052 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
4053 and initialize static variables for generating RTL for the statements
4057 init_function_start (tree subr)
4059 if (subr && DECL_STRUCT_FUNCTION (subr))
4060 set_cfun (DECL_STRUCT_FUNCTION (subr));
4062 allocate_struct_function (subr, false);
4063 prepare_function_start ();
4065 /* Warn if this value is an aggregate type,
4066 regardless of which calling convention we are using for it. */
4067 if (AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
4068 warning (OPT_Waggregate_return, "function returns an aggregate");
4071 /* Make sure all values used by the optimization passes have sane
4074 init_function_for_compilation (void)
4078 /* No prologue/epilogue insns yet. Make sure that these vectors are
4080 gcc_assert (VEC_length (int, prologue) == 0);
4081 gcc_assert (VEC_length (int, epilogue) == 0);
4082 gcc_assert (VEC_length (int, sibcall_epilogue) == 0);
4086 struct rtl_opt_pass pass_init_function =
4092 init_function_for_compilation, /* execute */
4095 0, /* static_pass_number */
4097 0, /* properties_required */
4098 0, /* properties_provided */
4099 0, /* properties_destroyed */
4100 0, /* todo_flags_start */
4101 0 /* todo_flags_finish */
4107 expand_main_function (void)
4109 #if (defined(INVOKE__main) \
4110 || (!defined(HAS_INIT_SECTION) \
4111 && !defined(INIT_SECTION_ASM_OP) \
4112 && !defined(INIT_ARRAY_SECTION_ASM_OP)))
4113 emit_library_call (init_one_libfunc (NAME__MAIN), LCT_NORMAL, VOIDmode, 0);
4117 /* Expand code to initialize the stack_protect_guard. This is invoked at
4118 the beginning of a function to be protected. */
4120 #ifndef HAVE_stack_protect_set
4121 # define HAVE_stack_protect_set 0
4122 # define gen_stack_protect_set(x,y) (gcc_unreachable (), NULL_RTX)
4126 stack_protect_prologue (void)
4128 tree guard_decl = targetm.stack_protect_guard ();
4131 /* Avoid expand_expr here, because we don't want guard_decl pulled
4132 into registers unless absolutely necessary. And we know that
4133 crtl->stack_protect_guard is a local stack slot, so this skips
4135 x = validize_mem (DECL_RTL (crtl->stack_protect_guard));
4136 y = validize_mem (DECL_RTL (guard_decl));
4138 /* Allow the target to copy from Y to X without leaking Y into a
4140 if (HAVE_stack_protect_set)
4142 rtx insn = gen_stack_protect_set (x, y);
4150 /* Otherwise do a straight move. */
4151 emit_move_insn (x, y);
4154 /* Expand code to verify the stack_protect_guard. This is invoked at
4155 the end of a function to be protected. */
4157 #ifndef HAVE_stack_protect_test
4158 # define HAVE_stack_protect_test 0
4159 # define gen_stack_protect_test(x, y, z) (gcc_unreachable (), NULL_RTX)
4163 stack_protect_epilogue (void)
4165 tree guard_decl = targetm.stack_protect_guard ();
4166 rtx label = gen_label_rtx ();
4169 /* Avoid expand_expr here, because we don't want guard_decl pulled
4170 into registers unless absolutely necessary. And we know that
4171 crtl->stack_protect_guard is a local stack slot, so this skips
4173 x = validize_mem (DECL_RTL (crtl->stack_protect_guard));
4174 y = validize_mem (DECL_RTL (guard_decl));
4176 /* Allow the target to compare Y with X without leaking either into
4178 switch (HAVE_stack_protect_test != 0)
4181 tmp = gen_stack_protect_test (x, y, label);
4190 emit_cmp_and_jump_insns (x, y, EQ, NULL_RTX, ptr_mode, 1, label);
4194 /* The noreturn predictor has been moved to the tree level. The rtl-level
4195 predictors estimate this branch about 20%, which isn't enough to get
4196 things moved out of line. Since this is the only extant case of adding
4197 a noreturn function at the rtl level, it doesn't seem worth doing ought
4198 except adding the prediction by hand. */
4199 tmp = get_last_insn ();
4201 predict_insn_def (tmp, PRED_NORETURN, TAKEN);
4203 expand_expr_stmt (targetm.stack_protect_fail ());
4207 /* Start the RTL for a new function, and set variables used for
4209 SUBR is the FUNCTION_DECL node.
4210 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
4211 the function's parameters, which must be run at any return statement. */
4214 expand_function_start (tree subr)
4216 /* Make sure volatile mem refs aren't considered
4217 valid operands of arithmetic insns. */
4218 init_recog_no_volatile ();
4222 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
4225 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
4227 /* Make the label for return statements to jump to. Do not special
4228 case machines with special return instructions -- they will be
4229 handled later during jump, ifcvt, or epilogue creation. */
4230 return_label = gen_label_rtx ();
4232 /* Initialize rtx used to return the value. */
4233 /* Do this before assign_parms so that we copy the struct value address
4234 before any library calls that assign parms might generate. */
4236 /* Decide whether to return the value in memory or in a register. */
4237 if (aggregate_value_p (DECL_RESULT (subr), subr))
4239 /* Returning something that won't go in a register. */
4240 rtx value_address = 0;
4242 #ifdef PCC_STATIC_STRUCT_RETURN
4243 if (cfun->returns_pcc_struct)
4245 int size = int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr)));
4246 value_address = assemble_static_space (size);
4251 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 2);
4252 /* Expect to be passed the address of a place to store the value.
4253 If it is passed as an argument, assign_parms will take care of
4257 value_address = gen_reg_rtx (Pmode);
4258 emit_move_insn (value_address, sv);
4263 rtx x = value_address;
4264 if (!DECL_BY_REFERENCE (DECL_RESULT (subr)))
4266 x = gen_rtx_MEM (DECL_MODE (DECL_RESULT (subr)), x);
4267 set_mem_attributes (x, DECL_RESULT (subr), 1);
4269 SET_DECL_RTL (DECL_RESULT (subr), x);
4272 else if (DECL_MODE (DECL_RESULT (subr)) == VOIDmode)
4273 /* If return mode is void, this decl rtl should not be used. */
4274 SET_DECL_RTL (DECL_RESULT (subr), NULL_RTX);
4277 /* Compute the return values into a pseudo reg, which we will copy
4278 into the true return register after the cleanups are done. */
4279 tree return_type = TREE_TYPE (DECL_RESULT (subr));
4280 if (TYPE_MODE (return_type) != BLKmode
4281 && targetm.calls.return_in_msb (return_type))
4282 /* expand_function_end will insert the appropriate padding in
4283 this case. Use the return value's natural (unpadded) mode
4284 within the function proper. */
4285 SET_DECL_RTL (DECL_RESULT (subr),
4286 gen_reg_rtx (TYPE_MODE (return_type)));
4289 /* In order to figure out what mode to use for the pseudo, we
4290 figure out what the mode of the eventual return register will
4291 actually be, and use that. */
4292 rtx hard_reg = hard_function_value (return_type, subr, 0, 1);
4294 /* Structures that are returned in registers are not
4295 aggregate_value_p, so we may see a PARALLEL or a REG. */
4296 if (REG_P (hard_reg))
4297 SET_DECL_RTL (DECL_RESULT (subr),
4298 gen_reg_rtx (GET_MODE (hard_reg)));
4301 gcc_assert (GET_CODE (hard_reg) == PARALLEL);
4302 SET_DECL_RTL (DECL_RESULT (subr), gen_group_rtx (hard_reg));
4306 /* Set DECL_REGISTER flag so that expand_function_end will copy the
4307 result to the real return register(s). */
4308 DECL_REGISTER (DECL_RESULT (subr)) = 1;
4311 /* Initialize rtx for parameters and local variables.
4312 In some cases this requires emitting insns. */
4313 assign_parms (subr);
4315 /* If function gets a static chain arg, store it. */
4316 if (cfun->static_chain_decl)
4318 tree parm = cfun->static_chain_decl;
4319 rtx local = gen_reg_rtx (Pmode);
4321 set_decl_incoming_rtl (parm, static_chain_incoming_rtx, false);
4322 SET_DECL_RTL (parm, local);
4323 mark_reg_pointer (local, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
4325 emit_move_insn (local, static_chain_incoming_rtx);
4328 /* If the function receives a non-local goto, then store the
4329 bits we need to restore the frame pointer. */
4330 if (cfun->nonlocal_goto_save_area)
4335 /* ??? We need to do this save early. Unfortunately here is
4336 before the frame variable gets declared. Help out... */
4337 tree var = TREE_OPERAND (cfun->nonlocal_goto_save_area, 0);
4338 if (!DECL_RTL_SET_P (var))
4341 t_save = build4 (ARRAY_REF, ptr_type_node,
4342 cfun->nonlocal_goto_save_area,
4343 integer_zero_node, NULL_TREE, NULL_TREE);
4344 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
4345 r_save = convert_memory_address (Pmode, r_save);
4347 emit_move_insn (r_save, targetm.builtin_setjmp_frame_value ());
4348 update_nonlocal_goto_save_area ();
4351 /* The following was moved from init_function_start.
4352 The move is supposed to make sdb output more accurate. */
4353 /* Indicate the beginning of the function body,
4354 as opposed to parm setup. */
4355 emit_note (NOTE_INSN_FUNCTION_BEG);
4357 gcc_assert (NOTE_P (get_last_insn ()));
4359 parm_birth_insn = get_last_insn ();
4364 PROFILE_HOOK (current_function_funcdef_no);
4368 /* After the display initializations is where the stack checking
4370 if(flag_stack_check)
4371 stack_check_probe_note = emit_note (NOTE_INSN_DELETED);
4373 /* Make sure there is a line number after the function entry setup code. */
4374 force_next_line_note ();
4377 /* Undo the effects of init_dummy_function_start. */
4379 expand_dummy_function_end (void)
4381 gcc_assert (in_dummy_function);
4383 /* End any sequences that failed to be closed due to syntax errors. */
4384 while (in_sequence_p ())
4387 /* Outside function body, can't compute type's actual size
4388 until next function's body starts. */
4390 free_after_parsing (cfun);
4391 free_after_compilation (cfun);
4393 in_dummy_function = false;
4396 /* Call DOIT for each hard register used as a return value from
4397 the current function. */
4400 diddle_return_value (void (*doit) (rtx, void *), void *arg)
4402 rtx outgoing = crtl->return_rtx;
4407 if (REG_P (outgoing))
4408 (*doit) (outgoing, arg);
4409 else if (GET_CODE (outgoing) == PARALLEL)
4413 for (i = 0; i < XVECLEN (outgoing, 0); i++)
4415 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
4417 if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
4424 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
4430 clobber_return_register (void)
4432 diddle_return_value (do_clobber_return_reg, NULL);
4434 /* In case we do use pseudo to return value, clobber it too. */
4435 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
4437 tree decl_result = DECL_RESULT (current_function_decl);
4438 rtx decl_rtl = DECL_RTL (decl_result);
4439 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
4441 do_clobber_return_reg (decl_rtl, NULL);
4447 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
4453 use_return_register (void)
4455 diddle_return_value (do_use_return_reg, NULL);
4458 /* Possibly warn about unused parameters. */
4460 do_warn_unused_parameter (tree fn)
4464 for (decl = DECL_ARGUMENTS (fn);
4465 decl; decl = TREE_CHAIN (decl))
4466 if (!TREE_USED (decl) && TREE_CODE (decl) == PARM_DECL
4467 && DECL_NAME (decl) && !DECL_ARTIFICIAL (decl)
4468 && !TREE_NO_WARNING (decl))
4469 warning (OPT_Wunused_parameter, "unused parameter %q+D", decl);
4472 static GTY(()) rtx initial_trampoline;
4474 /* Generate RTL for the end of the current function. */
4477 expand_function_end (void)
4481 /* If arg_pointer_save_area was referenced only from a nested
4482 function, we will not have initialized it yet. Do that now. */
4483 if (arg_pointer_save_area && ! crtl->arg_pointer_save_area_init)
4484 get_arg_pointer_save_area ();
4486 /* If we are doing generic stack checking and this function makes calls,
4487 do a stack probe at the start of the function to ensure we have enough
4488 space for another stack frame. */
4489 if (flag_stack_check == GENERIC_STACK_CHECK)
4493 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
4497 probe_stack_range (STACK_OLD_CHECK_PROTECT,
4498 GEN_INT (STACK_CHECK_MAX_FRAME_SIZE));
4501 emit_insn_before (seq, stack_check_probe_note);
4506 /* End any sequences that failed to be closed due to syntax errors. */
4507 while (in_sequence_p ())
4510 clear_pending_stack_adjust ();
4511 do_pending_stack_adjust ();
4513 /* Output a linenumber for the end of the function.
4514 SDB depends on this. */
4515 force_next_line_note ();
4516 set_curr_insn_source_location (input_location);
4518 /* Before the return label (if any), clobber the return
4519 registers so that they are not propagated live to the rest of
4520 the function. This can only happen with functions that drop
4521 through; if there had been a return statement, there would
4522 have either been a return rtx, or a jump to the return label.
4524 We delay actual code generation after the current_function_value_rtx
4526 clobber_after = get_last_insn ();
4528 /* Output the label for the actual return from the function. */
4529 emit_label (return_label);
4531 if (USING_SJLJ_EXCEPTIONS)
4533 /* Let except.c know where it should emit the call to unregister
4534 the function context for sjlj exceptions. */
4535 if (flag_exceptions)
4536 sjlj_emit_function_exit_after (get_last_insn ());
4540 /* We want to ensure that instructions that may trap are not
4541 moved into the epilogue by scheduling, because we don't
4542 always emit unwind information for the epilogue. */
4543 if (flag_non_call_exceptions)
4544 emit_insn (gen_blockage ());
4547 /* If this is an implementation of throw, do what's necessary to
4548 communicate between __builtin_eh_return and the epilogue. */
4549 expand_eh_return ();
4551 /* If scalar return value was computed in a pseudo-reg, or was a named
4552 return value that got dumped to the stack, copy that to the hard
4554 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
4556 tree decl_result = DECL_RESULT (current_function_decl);
4557 rtx decl_rtl = DECL_RTL (decl_result);
4559 if (REG_P (decl_rtl)
4560 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
4561 : DECL_REGISTER (decl_result))
4563 rtx real_decl_rtl = crtl->return_rtx;
4565 /* This should be set in assign_parms. */
4566 gcc_assert (REG_FUNCTION_VALUE_P (real_decl_rtl));
4568 /* If this is a BLKmode structure being returned in registers,
4569 then use the mode computed in expand_return. Note that if
4570 decl_rtl is memory, then its mode may have been changed,
4571 but that crtl->return_rtx has not. */
4572 if (GET_MODE (real_decl_rtl) == BLKmode)
4573 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
4575 /* If a non-BLKmode return value should be padded at the least
4576 significant end of the register, shift it left by the appropriate
4577 amount. BLKmode results are handled using the group load/store
4579 if (TYPE_MODE (TREE_TYPE (decl_result)) != BLKmode
4580 && targetm.calls.return_in_msb (TREE_TYPE (decl_result)))
4582 emit_move_insn (gen_rtx_REG (GET_MODE (decl_rtl),
4583 REGNO (real_decl_rtl)),
4585 shift_return_value (GET_MODE (decl_rtl), true, real_decl_rtl);
4587 /* If a named return value dumped decl_return to memory, then
4588 we may need to re-do the PROMOTE_MODE signed/unsigned
4590 else if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
4592 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
4594 if (targetm.calls.promote_function_return (TREE_TYPE (current_function_decl)))
4595 promote_mode (TREE_TYPE (decl_result), GET_MODE (decl_rtl),
4598 convert_move (real_decl_rtl, decl_rtl, unsignedp);
4600 else if (GET_CODE (real_decl_rtl) == PARALLEL)
4602 /* If expand_function_start has created a PARALLEL for decl_rtl,
4603 move the result to the real return registers. Otherwise, do
4604 a group load from decl_rtl for a named return. */
4605 if (GET_CODE (decl_rtl) == PARALLEL)
4606 emit_group_move (real_decl_rtl, decl_rtl);
4608 emit_group_load (real_decl_rtl, decl_rtl,
4609 TREE_TYPE (decl_result),
4610 int_size_in_bytes (TREE_TYPE (decl_result)));
4612 /* In the case of complex integer modes smaller than a word, we'll
4613 need to generate some non-trivial bitfield insertions. Do that
4614 on a pseudo and not the hard register. */
4615 else if (GET_CODE (decl_rtl) == CONCAT
4616 && GET_MODE_CLASS (GET_MODE (decl_rtl)) == MODE_COMPLEX_INT
4617 && GET_MODE_BITSIZE (GET_MODE (decl_rtl)) <= BITS_PER_WORD)
4619 int old_generating_concat_p;
4622 old_generating_concat_p = generating_concat_p;
4623 generating_concat_p = 0;
4624 tmp = gen_reg_rtx (GET_MODE (decl_rtl));
4625 generating_concat_p = old_generating_concat_p;
4627 emit_move_insn (tmp, decl_rtl);
4628 emit_move_insn (real_decl_rtl, tmp);
4631 emit_move_insn (real_decl_rtl, decl_rtl);
4635 /* If returning a structure, arrange to return the address of the value
4636 in a place where debuggers expect to find it.
4638 If returning a structure PCC style,
4639 the caller also depends on this value.
4640 And cfun->returns_pcc_struct is not necessarily set. */
4641 if (cfun->returns_struct
4642 || cfun->returns_pcc_struct)
4644 rtx value_address = DECL_RTL (DECL_RESULT (current_function_decl));
4645 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
4648 if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
4649 type = TREE_TYPE (type);
4651 value_address = XEXP (value_address, 0);
4653 outgoing = targetm.calls.function_value (build_pointer_type (type),
4654 current_function_decl, true);
4656 /* Mark this as a function return value so integrate will delete the
4657 assignment and USE below when inlining this function. */
4658 REG_FUNCTION_VALUE_P (outgoing) = 1;
4660 /* The address may be ptr_mode and OUTGOING may be Pmode. */
4661 value_address = convert_memory_address (GET_MODE (outgoing),
4664 emit_move_insn (outgoing, value_address);
4666 /* Show return register used to hold result (in this case the address
4668 crtl->return_rtx = outgoing;
4671 /* Emit the actual code to clobber return register. */
4676 clobber_return_register ();
4677 expand_naked_return ();
4681 emit_insn_after (seq, clobber_after);
4684 /* Output the label for the naked return from the function. */
4685 emit_label (naked_return_label);
4687 /* @@@ This is a kludge. We want to ensure that instructions that
4688 may trap are not moved into the epilogue by scheduling, because
4689 we don't always emit unwind information for the epilogue. */
4690 if (! USING_SJLJ_EXCEPTIONS && flag_non_call_exceptions)
4691 emit_insn (gen_blockage ());
4693 /* If stack protection is enabled for this function, check the guard. */
4694 if (crtl->stack_protect_guard)
4695 stack_protect_epilogue ();
4697 /* If we had calls to alloca, and this machine needs
4698 an accurate stack pointer to exit the function,
4699 insert some code to save and restore the stack pointer. */
4700 if (! EXIT_IGNORE_STACK
4701 && cfun->calls_alloca)
4705 emit_stack_save (SAVE_FUNCTION, &tem, parm_birth_insn);
4706 emit_stack_restore (SAVE_FUNCTION, tem, NULL_RTX);
4709 /* ??? This should no longer be necessary since stupid is no longer with
4710 us, but there are some parts of the compiler (eg reload_combine, and
4711 sh mach_dep_reorg) that still try and compute their own lifetime info
4712 instead of using the general framework. */
4713 use_return_register ();
4717 get_arg_pointer_save_area (void)
4719 rtx ret = arg_pointer_save_area;
4723 ret = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
4724 arg_pointer_save_area = ret;
4727 if (! crtl->arg_pointer_save_area_init)
4731 /* Save the arg pointer at the beginning of the function. The
4732 generated stack slot may not be a valid memory address, so we
4733 have to check it and fix it if necessary. */
4735 emit_move_insn (validize_mem (ret),
4736 crtl->args.internal_arg_pointer);
4740 push_topmost_sequence ();
4741 emit_insn_after (seq, entry_of_function ());
4742 pop_topmost_sequence ();
4748 /* Extend a vector that records the INSN_UIDs of INSNS
4749 (a list of one or more insns). */
4752 record_insns (rtx insns, VEC(int,heap) **vecp)
4756 for (tmp = insns; tmp != NULL_RTX; tmp = NEXT_INSN (tmp))
4757 VEC_safe_push (int, heap, *vecp, INSN_UID (tmp));
4760 /* Set the locator of the insn chain starting at INSN to LOC. */
4762 set_insn_locators (rtx insn, int loc)
4764 while (insn != NULL_RTX)
4767 INSN_LOCATOR (insn) = loc;
4768 insn = NEXT_INSN (insn);
4772 /* Determine how many INSN_UIDs in VEC are part of INSN. Because we can
4773 be running after reorg, SEQUENCE rtl is possible. */
4776 contains (const_rtx insn, VEC(int,heap) **vec)
4780 if (NONJUMP_INSN_P (insn)
4781 && GET_CODE (PATTERN (insn)) == SEQUENCE)
4784 for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
4785 for (j = VEC_length (int, *vec) - 1; j >= 0; --j)
4786 if (INSN_UID (XVECEXP (PATTERN (insn), 0, i))
4787 == VEC_index (int, *vec, j))
4793 for (j = VEC_length (int, *vec) - 1; j >= 0; --j)
4794 if (INSN_UID (insn) == VEC_index (int, *vec, j))
4801 prologue_epilogue_contains (const_rtx insn)
4803 if (contains (insn, &prologue))
4805 if (contains (insn, &epilogue))
4811 sibcall_epilogue_contains (const_rtx insn)
4813 if (sibcall_epilogue)
4814 return contains (insn, &sibcall_epilogue);
4819 /* Insert gen_return at the end of block BB. This also means updating
4820 block_for_insn appropriately. */
4823 emit_return_into_block (basic_block bb)
4825 emit_jump_insn_after (gen_return (), BB_END (bb));
4827 #endif /* HAVE_return */
4829 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
4830 this into place with notes indicating where the prologue ends and where
4831 the epilogue begins. Update the basic block information when possible. */
4834 thread_prologue_and_epilogue_insns (void)
4838 #if defined (HAVE_sibcall_epilogue) || defined (HAVE_epilogue) || defined (HAVE_return) || defined (HAVE_prologue)
4841 #if defined (HAVE_epilogue) || defined(HAVE_return)
4842 rtx epilogue_end = NULL_RTX;
4846 rtl_profile_for_bb (ENTRY_BLOCK_PTR);
4847 #ifdef HAVE_prologue
4851 seq = gen_prologue ();
4854 /* Insert an explicit USE for the frame pointer
4855 if the profiling is on and the frame pointer is required. */
4856 if (crtl->profile && frame_pointer_needed)
4857 emit_use (hard_frame_pointer_rtx);
4859 /* Retain a map of the prologue insns. */
4860 record_insns (seq, &prologue);
4861 emit_note (NOTE_INSN_PROLOGUE_END);
4863 #ifndef PROFILE_BEFORE_PROLOGUE
4864 /* Ensure that instructions are not moved into the prologue when
4865 profiling is on. The call to the profiling routine can be
4866 emitted within the live range of a call-clobbered register. */
4868 emit_insn (gen_blockage ());
4873 set_insn_locators (seq, prologue_locator);
4875 /* Can't deal with multiple successors of the entry block
4876 at the moment. Function should always have at least one
4878 gcc_assert (single_succ_p (ENTRY_BLOCK_PTR));
4880 insert_insn_on_edge (seq, single_succ_edge (ENTRY_BLOCK_PTR));
4885 /* If the exit block has no non-fake predecessors, we don't need
4887 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
4888 if ((e->flags & EDGE_FAKE) == 0)
4893 rtl_profile_for_bb (EXIT_BLOCK_PTR);
4895 if (optimize && HAVE_return)
4897 /* If we're allowed to generate a simple return instruction,
4898 then by definition we don't need a full epilogue. Examine
4899 the block that falls through to EXIT. If it does not
4900 contain any code, examine its predecessors and try to
4901 emit (conditional) return instructions. */
4906 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
4907 if (e->flags & EDGE_FALLTHRU)
4913 /* Verify that there are no active instructions in the last block. */
4914 label = BB_END (last);
4915 while (label && !LABEL_P (label))
4917 if (active_insn_p (label))
4919 label = PREV_INSN (label);
4922 if (BB_HEAD (last) == label && LABEL_P (label))
4926 for (ei2 = ei_start (last->preds); (e = ei_safe_edge (ei2)); )
4928 basic_block bb = e->src;
4931 if (bb == ENTRY_BLOCK_PTR)
4938 if (!JUMP_P (jump) || JUMP_LABEL (jump) != label)
4944 /* If we have an unconditional jump, we can replace that
4945 with a simple return instruction. */
4946 if (simplejump_p (jump))
4948 emit_return_into_block (bb);
4952 /* If we have a conditional jump, we can try to replace
4953 that with a conditional return instruction. */
4954 else if (condjump_p (jump))
4956 if (! redirect_jump (jump, 0, 0))
4962 /* If this block has only one successor, it both jumps
4963 and falls through to the fallthru block, so we can't
4965 if (single_succ_p (bb))
4977 /* Fix up the CFG for the successful change we just made. */
4978 redirect_edge_succ (e, EXIT_BLOCK_PTR);
4981 /* Emit a return insn for the exit fallthru block. Whether
4982 this is still reachable will be determined later. */
4984 emit_barrier_after (BB_END (last));
4985 emit_return_into_block (last);
4986 epilogue_end = BB_END (last);
4987 single_succ_edge (last)->flags &= ~EDGE_FALLTHRU;
4992 /* Find the edge that falls through to EXIT. Other edges may exist
4993 due to RETURN instructions, but those don't need epilogues.
4994 There really shouldn't be a mixture -- either all should have
4995 been converted or none, however... */
4997 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
4998 if (e->flags & EDGE_FALLTHRU)
5003 #ifdef HAVE_epilogue
5007 epilogue_end = emit_note (NOTE_INSN_EPILOGUE_BEG);
5008 seq = gen_epilogue ();
5009 emit_jump_insn (seq);
5011 /* Retain a map of the epilogue insns. */
5012 record_insns (seq, &epilogue);
5013 set_insn_locators (seq, epilogue_locator);
5018 insert_insn_on_edge (seq, e);
5026 if (! next_active_insn (BB_END (e->src)))
5028 /* We have a fall-through edge to the exit block, the source is not
5029 at the end of the function, and there will be an assembler epilogue
5030 at the end of the function.
5031 We can't use force_nonfallthru here, because that would try to
5032 use return. Inserting a jump 'by hand' is extremely messy, so
5033 we take advantage of cfg_layout_finalize using
5034 fixup_fallthru_exit_predecessor. */
5035 cfg_layout_initialize (0);
5036 FOR_EACH_BB (cur_bb)
5037 if (cur_bb->index >= NUM_FIXED_BLOCKS
5038 && cur_bb->next_bb->index >= NUM_FIXED_BLOCKS)
5039 cur_bb->aux = cur_bb->next_bb;
5040 cfg_layout_finalize ();
5043 default_rtl_profile ();
5047 commit_edge_insertions ();
5049 /* The epilogue insns we inserted may cause the exit edge to no longer
5051 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5053 if (((e->flags & EDGE_FALLTHRU) != 0)
5054 && returnjump_p (BB_END (e->src)))
5055 e->flags &= ~EDGE_FALLTHRU;
5059 #ifdef HAVE_sibcall_epilogue
5060 /* Emit sibling epilogues before any sibling call sites. */
5061 for (ei = ei_start (EXIT_BLOCK_PTR->preds); (e = ei_safe_edge (ei)); )
5063 basic_block bb = e->src;
5064 rtx insn = BB_END (bb);
5067 || ! SIBLING_CALL_P (insn))
5074 emit_insn (gen_sibcall_epilogue ());
5078 /* Retain a map of the epilogue insns. Used in life analysis to
5079 avoid getting rid of sibcall epilogue insns. Do this before we
5080 actually emit the sequence. */
5081 record_insns (seq, &sibcall_epilogue);
5082 set_insn_locators (seq, epilogue_locator);
5084 emit_insn_before (seq, insn);
5089 #ifdef HAVE_epilogue
5094 /* Similarly, move any line notes that appear after the epilogue.
5095 There is no need, however, to be quite so anal about the existence
5096 of such a note. Also possibly move
5097 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
5099 for (insn = epilogue_end; insn; insn = next)
5101 next = NEXT_INSN (insn);
5103 && (NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG))
5104 reorder_insns (insn, insn, PREV_INSN (epilogue_end));
5109 /* Threading the prologue and epilogue changes the artificial refs
5110 in the entry and exit blocks. */
5111 epilogue_completed = 1;
5112 df_update_entry_exit_and_calls ();
5115 /* Reposition the prologue-end and epilogue-begin notes after instruction
5116 scheduling and delayed branch scheduling. */
5119 reposition_prologue_and_epilogue_notes (void)
5121 #if defined (HAVE_prologue) || defined (HAVE_epilogue)
5122 rtx insn, last, note;
5125 if ((len = VEC_length (int, prologue)) > 0)
5129 /* Scan from the beginning until we reach the last prologue insn.
5130 We apparently can't depend on basic_block_{head,end} after
5132 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
5136 if (NOTE_KIND (insn) == NOTE_INSN_PROLOGUE_END)
5139 else if (contains (insn, &prologue))
5149 /* Find the prologue-end note if we haven't already, and
5150 move it to just after the last prologue insn. */
5153 for (note = last; (note = NEXT_INSN (note));)
5155 && NOTE_KIND (note) == NOTE_INSN_PROLOGUE_END)
5159 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
5161 last = NEXT_INSN (last);
5162 reorder_insns (note, note, last);
5166 if ((len = VEC_length (int, epilogue)) > 0)
5170 /* Scan from the end until we reach the first epilogue insn.
5171 We apparently can't depend on basic_block_{head,end} after
5173 for (insn = get_last_insn (); insn; insn = PREV_INSN (insn))
5177 if (NOTE_KIND (insn) == NOTE_INSN_EPILOGUE_BEG)
5180 else if (contains (insn, &epilogue))
5190 /* Find the epilogue-begin note if we haven't already, and
5191 move it to just before the first epilogue insn. */
5194 for (note = insn; (note = PREV_INSN (note));)
5196 && NOTE_KIND (note) == NOTE_INSN_EPILOGUE_BEG)
5200 if (PREV_INSN (last) != note)
5201 reorder_insns (note, note, PREV_INSN (last));
5204 #endif /* HAVE_prologue or HAVE_epilogue */
5207 /* Returns the name of the current function. */
5209 current_function_name (void)
5211 return lang_hooks.decl_printable_name (cfun->decl, 2);
5214 /* Returns the raw (mangled) name of the current function. */
5216 current_function_assembler_name (void)
5218 return IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (cfun->decl));
5223 rest_of_handle_check_leaf_regs (void)
5225 #ifdef LEAF_REGISTERS
5226 current_function_uses_only_leaf_regs
5227 = optimize > 0 && only_leaf_regs_used () && leaf_function_p ();
5232 /* Insert a TYPE into the used types hash table of CFUN. */
5234 used_types_insert_helper (tree type, struct function *func)
5236 if (type != NULL && func != NULL)
5240 if (func->used_types_hash == NULL)
5241 func->used_types_hash = htab_create_ggc (37, htab_hash_pointer,
5242 htab_eq_pointer, NULL);
5243 slot = htab_find_slot (func->used_types_hash, type, INSERT);
5249 /* Given a type, insert it into the used hash table in cfun. */
5251 used_types_insert (tree t)
5253 while (POINTER_TYPE_P (t) || TREE_CODE (t) == ARRAY_TYPE)
5255 t = TYPE_MAIN_VARIANT (t);
5256 if (debug_info_level > DINFO_LEVEL_NONE)
5257 used_types_insert_helper (t, cfun);
5260 struct rtl_opt_pass pass_leaf_regs =
5266 rest_of_handle_check_leaf_regs, /* execute */
5269 0, /* static_pass_number */
5271 0, /* properties_required */
5272 0, /* properties_provided */
5273 0, /* properties_destroyed */
5274 0, /* todo_flags_start */
5275 0 /* todo_flags_finish */
5280 rest_of_handle_thread_prologue_and_epilogue (void)
5283 cleanup_cfg (CLEANUP_EXPENSIVE);
5284 /* On some machines, the prologue and epilogue code, or parts thereof,
5285 can be represented as RTL. Doing so lets us schedule insns between
5286 it and the rest of the code and also allows delayed branch
5287 scheduling to operate in the epilogue. */
5289 thread_prologue_and_epilogue_insns ();
5293 struct rtl_opt_pass pass_thread_prologue_and_epilogue =
5297 "pro_and_epilogue", /* name */
5299 rest_of_handle_thread_prologue_and_epilogue, /* execute */
5302 0, /* static_pass_number */
5303 TV_THREAD_PROLOGUE_AND_EPILOGUE, /* tv_id */
5304 0, /* properties_required */
5305 0, /* properties_provided */
5306 0, /* properties_destroyed */
5307 TODO_verify_flow, /* todo_flags_start */
5310 TODO_df_finish | TODO_verify_rtl_sharing |
5311 TODO_ggc_collect /* todo_flags_finish */
5316 /* This mini-pass fixes fall-out from SSA in asm statements that have
5317 in-out constraints. Say you start with
5320 asm ("": "+mr" (inout));
5323 which is transformed very early to use explicit output and match operands:
5326 asm ("": "=mr" (inout) : "0" (inout));
5329 Or, after SSA and copyprop,
5331 asm ("": "=mr" (inout_2) : "0" (inout_1));
5334 Clearly inout_2 and inout_1 can't be coalesced easily anymore, as
5335 they represent two separate values, so they will get different pseudo
5336 registers during expansion. Then, since the two operands need to match
5337 per the constraints, but use different pseudo registers, reload can
5338 only register a reload for these operands. But reloads can only be
5339 satisfied by hardregs, not by memory, so we need a register for this
5340 reload, just because we are presented with non-matching operands.
5341 So, even though we allow memory for this operand, no memory can be
5342 used for it, just because the two operands don't match. This can
5343 cause reload failures on register-starved targets.
5345 So it's a symptom of reload not being able to use memory for reloads
5346 or, alternatively it's also a symptom of both operands not coming into
5347 reload as matching (in which case the pseudo could go to memory just
5348 fine, as the alternative allows it, and no reload would be necessary).
5349 We fix the latter problem here, by transforming
5351 asm ("": "=mr" (inout_2) : "0" (inout_1));
5356 asm ("": "=mr" (inout_2) : "0" (inout_2)); */
5359 match_asm_constraints_1 (rtx insn, rtx *p_sets, int noutputs)
5362 bool changed = false;
5363 rtx op = SET_SRC (p_sets[0]);
5364 int ninputs = ASM_OPERANDS_INPUT_LENGTH (op);
5365 rtvec inputs = ASM_OPERANDS_INPUT_VEC (op);
5366 bool *output_matched = XALLOCAVEC (bool, noutputs);
5368 memset (output_matched, 0, noutputs * sizeof (bool));
5369 for (i = 0; i < ninputs; i++)
5371 rtx input, output, insns;
5372 const char *constraint = ASM_OPERANDS_INPUT_CONSTRAINT (op, i);
5376 match = strtoul (constraint, &end, 10);
5377 if (end == constraint)
5380 gcc_assert (match < noutputs);
5381 output = SET_DEST (p_sets[match]);
5382 input = RTVEC_ELT (inputs, i);
5383 /* Only do the transformation for pseudos. */
5384 if (! REG_P (output)
5385 || rtx_equal_p (output, input)
5386 || (GET_MODE (input) != VOIDmode
5387 && GET_MODE (input) != GET_MODE (output)))
5390 /* We can't do anything if the output is also used as input,
5391 as we're going to overwrite it. */
5392 for (j = 0; j < ninputs; j++)
5393 if (reg_overlap_mentioned_p (output, RTVEC_ELT (inputs, j)))
5398 /* Avoid changing the same input several times. For
5399 asm ("" : "=mr" (out1), "=mr" (out2) : "0" (in), "1" (in));
5400 only change in once (to out1), rather than changing it
5401 first to out1 and afterwards to out2. */
5404 for (j = 0; j < noutputs; j++)
5405 if (output_matched[j] && input == SET_DEST (p_sets[j]))
5410 output_matched[match] = true;
5413 emit_move_insn (output, input);
5414 insns = get_insns ();
5416 emit_insn_before (insns, insn);
5418 /* Now replace all mentions of the input with output. We can't
5419 just replace the occurrence in inputs[i], as the register might
5420 also be used in some other input (or even in an address of an
5421 output), which would mean possibly increasing the number of
5422 inputs by one (namely 'output' in addition), which might pose
5423 a too complicated problem for reload to solve. E.g. this situation:
5425 asm ("" : "=r" (output), "=m" (input) : "0" (input))
5427 Here 'input' is used in two occurrences as input (once for the
5428 input operand, once for the address in the second output operand).
5429 If we would replace only the occurrence of the input operand (to
5430 make the matching) we would be left with this:
5433 asm ("" : "=r" (output), "=m" (input) : "0" (output))
5435 Now we suddenly have two different input values (containing the same
5436 value, but different pseudos) where we formerly had only one.
5437 With more complicated asms this might lead to reload failures
5438 which wouldn't have happen without this pass. So, iterate over
5439 all operands and replace all occurrences of the register used. */
5440 for (j = 0; j < noutputs; j++)
5441 if (!rtx_equal_p (SET_DEST (p_sets[j]), input)
5442 && reg_overlap_mentioned_p (input, SET_DEST (p_sets[j])))
5443 SET_DEST (p_sets[j]) = replace_rtx (SET_DEST (p_sets[j]),
5445 for (j = 0; j < ninputs; j++)
5446 if (reg_overlap_mentioned_p (input, RTVEC_ELT (inputs, j)))
5447 RTVEC_ELT (inputs, j) = replace_rtx (RTVEC_ELT (inputs, j),
5454 df_insn_rescan (insn);
5458 rest_of_match_asm_constraints (void)
5461 rtx insn, pat, *p_sets;
5464 if (!crtl->has_asm_statement)
5467 df_set_flags (DF_DEFER_INSN_RESCAN);
5470 FOR_BB_INSNS (bb, insn)
5475 pat = PATTERN (insn);
5476 if (GET_CODE (pat) == PARALLEL)
5477 p_sets = &XVECEXP (pat, 0, 0), noutputs = XVECLEN (pat, 0);
5478 else if (GET_CODE (pat) == SET)
5479 p_sets = &PATTERN (insn), noutputs = 1;
5483 if (GET_CODE (*p_sets) == SET
5484 && GET_CODE (SET_SRC (*p_sets)) == ASM_OPERANDS)
5485 match_asm_constraints_1 (insn, p_sets, noutputs);
5489 return TODO_df_finish;
5492 struct rtl_opt_pass pass_match_asm_constraints =
5496 "asmcons", /* name */
5498 rest_of_match_asm_constraints, /* execute */
5501 0, /* static_pass_number */
5503 0, /* properties_required */
5504 0, /* properties_provided */
5505 0, /* properties_destroyed */
5506 0, /* todo_flags_start */
5507 TODO_dump_func /* todo_flags_finish */
5512 #include "gt-function.h"