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 is an alternate way of referring to the temp slot
936 that previously was known by OLD. */
939 update_temp_slot_address (rtx old, rtx new)
943 if (rtx_equal_p (old, new))
946 p = find_temp_slot_from_address (old);
948 /* If we didn't find one, see if both OLD is a PLUS. If so, and NEW
949 is a register, see if one operand of the PLUS is a temporary
950 location. If so, NEW points into it. Otherwise, if both OLD and
951 NEW are a PLUS and if there is a register in common between them.
952 If so, try a recursive call on those values. */
955 if (GET_CODE (old) != PLUS)
960 update_temp_slot_address (XEXP (old, 0), new);
961 update_temp_slot_address (XEXP (old, 1), new);
964 else if (GET_CODE (new) != PLUS)
967 if (rtx_equal_p (XEXP (old, 0), XEXP (new, 0)))
968 update_temp_slot_address (XEXP (old, 1), XEXP (new, 1));
969 else if (rtx_equal_p (XEXP (old, 1), XEXP (new, 0)))
970 update_temp_slot_address (XEXP (old, 0), XEXP (new, 1));
971 else if (rtx_equal_p (XEXP (old, 0), XEXP (new, 1)))
972 update_temp_slot_address (XEXP (old, 1), XEXP (new, 0));
973 else if (rtx_equal_p (XEXP (old, 1), XEXP (new, 1)))
974 update_temp_slot_address (XEXP (old, 0), XEXP (new, 0));
979 /* Otherwise add an alias for the temp's address. */
980 else if (p->address == 0)
984 if (GET_CODE (p->address) != EXPR_LIST)
985 p->address = gen_rtx_EXPR_LIST (VOIDmode, p->address, NULL_RTX);
987 p->address = gen_rtx_EXPR_LIST (VOIDmode, new, p->address);
991 /* If X could be a reference to a temporary slot, mark the fact that its
992 address was taken. */
995 mark_temp_addr_taken (rtx x)
1002 /* If X is not in memory or is at a constant address, it cannot be in
1003 a temporary slot. */
1004 if (!MEM_P (x) || CONSTANT_P (XEXP (x, 0)))
1007 p = find_temp_slot_from_address (XEXP (x, 0));
1012 /* If X could be a reference to a temporary slot, mark that slot as
1013 belonging to the to one level higher than the current level. If X
1014 matched one of our slots, just mark that one. Otherwise, we can't
1015 easily predict which it is, so upgrade all of them. Kept slots
1016 need not be touched.
1018 This is called when an ({...}) construct occurs and a statement
1019 returns a value in memory. */
1022 preserve_temp_slots (rtx x)
1024 struct temp_slot *p = 0, *next;
1026 /* If there is no result, we still might have some objects whose address
1027 were taken, so we need to make sure they stay around. */
1030 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1035 move_slot_to_level (p, temp_slot_level - 1);
1041 /* If X is a register that is being used as a pointer, see if we have
1042 a temporary slot we know it points to. To be consistent with
1043 the code below, we really should preserve all non-kept slots
1044 if we can't find a match, but that seems to be much too costly. */
1045 if (REG_P (x) && REG_POINTER (x))
1046 p = find_temp_slot_from_address (x);
1048 /* If X is not in memory or is at a constant address, it cannot be in
1049 a temporary slot, but it can contain something whose address was
1051 if (p == 0 && (!MEM_P (x) || CONSTANT_P (XEXP (x, 0))))
1053 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1058 move_slot_to_level (p, temp_slot_level - 1);
1064 /* First see if we can find a match. */
1066 p = find_temp_slot_from_address (XEXP (x, 0));
1070 /* Move everything at our level whose address was taken to our new
1071 level in case we used its address. */
1072 struct temp_slot *q;
1074 if (p->level == temp_slot_level)
1076 for (q = *temp_slots_at_level (temp_slot_level); q; q = next)
1080 if (p != q && q->addr_taken)
1081 move_slot_to_level (q, temp_slot_level - 1);
1084 move_slot_to_level (p, temp_slot_level - 1);
1090 /* Otherwise, preserve all non-kept slots at this level. */
1091 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1096 move_slot_to_level (p, temp_slot_level - 1);
1100 /* Free all temporaries used so far. This is normally called at the
1101 end of generating code for a statement. */
1104 free_temp_slots (void)
1106 struct temp_slot *p, *next;
1108 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1113 make_slot_available (p);
1116 combine_temp_slots ();
1119 /* Push deeper into the nesting level for stack temporaries. */
1122 push_temp_slots (void)
1127 /* Pop a temporary nesting level. All slots in use in the current level
1131 pop_temp_slots (void)
1133 struct temp_slot *p, *next;
1135 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1138 make_slot_available (p);
1141 combine_temp_slots ();
1146 /* Initialize temporary slots. */
1149 init_temp_slots (void)
1151 /* We have not allocated any temporaries yet. */
1152 avail_temp_slots = 0;
1153 used_temp_slots = 0;
1154 temp_slot_level = 0;
1157 /* These routines are responsible for converting virtual register references
1158 to the actual hard register references once RTL generation is complete.
1160 The following four variables are used for communication between the
1161 routines. They contain the offsets of the virtual registers from their
1162 respective hard registers. */
1164 static int in_arg_offset;
1165 static int var_offset;
1166 static int dynamic_offset;
1167 static int out_arg_offset;
1168 static int cfa_offset;
1170 /* In most machines, the stack pointer register is equivalent to the bottom
1173 #ifndef STACK_POINTER_OFFSET
1174 #define STACK_POINTER_OFFSET 0
1177 /* If not defined, pick an appropriate default for the offset of dynamically
1178 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
1179 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
1181 #ifndef STACK_DYNAMIC_OFFSET
1183 /* The bottom of the stack points to the actual arguments. If
1184 REG_PARM_STACK_SPACE is defined, this includes the space for the register
1185 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
1186 stack space for register parameters is not pushed by the caller, but
1187 rather part of the fixed stack areas and hence not included in
1188 `crtl->outgoing_args_size'. Nevertheless, we must allow
1189 for it when allocating stack dynamic objects. */
1191 #if defined(REG_PARM_STACK_SPACE)
1192 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1193 ((ACCUMULATE_OUTGOING_ARGS \
1194 ? (crtl->outgoing_args_size \
1195 + (OUTGOING_REG_PARM_STACK_SPACE ((!(FNDECL) ? NULL_TREE : TREE_TYPE (FNDECL))) ? 0 \
1196 : REG_PARM_STACK_SPACE (FNDECL))) \
1197 : 0) + (STACK_POINTER_OFFSET))
1199 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1200 ((ACCUMULATE_OUTGOING_ARGS ? crtl->outgoing_args_size : 0) \
1201 + (STACK_POINTER_OFFSET))
1206 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
1207 is a virtual register, return the equivalent hard register and set the
1208 offset indirectly through the pointer. Otherwise, return 0. */
1211 instantiate_new_reg (rtx x, HOST_WIDE_INT *poffset)
1214 HOST_WIDE_INT offset;
1216 if (x == virtual_incoming_args_rtx)
1218 if (stack_realign_drap)
1220 /* Replace virtual_incoming_args_rtx with internal arg
1221 pointer if DRAP is used to realign stack. */
1222 new = crtl->args.internal_arg_pointer;
1226 new = arg_pointer_rtx, offset = in_arg_offset;
1228 else if (x == virtual_stack_vars_rtx)
1229 new = frame_pointer_rtx, offset = var_offset;
1230 else if (x == virtual_stack_dynamic_rtx)
1231 new = stack_pointer_rtx, offset = dynamic_offset;
1232 else if (x == virtual_outgoing_args_rtx)
1233 new = stack_pointer_rtx, offset = out_arg_offset;
1234 else if (x == virtual_cfa_rtx)
1236 #ifdef FRAME_POINTER_CFA_OFFSET
1237 new = frame_pointer_rtx;
1239 new = arg_pointer_rtx;
1241 offset = cfa_offset;
1250 /* A subroutine of instantiate_virtual_regs, called via for_each_rtx.
1251 Instantiate any virtual registers present inside of *LOC. The expression
1252 is simplified, as much as possible, but is not to be considered "valid"
1253 in any sense implied by the target. If any change is made, set CHANGED
1257 instantiate_virtual_regs_in_rtx (rtx *loc, void *data)
1259 HOST_WIDE_INT offset;
1260 bool *changed = (bool *) data;
1267 switch (GET_CODE (x))
1270 new = instantiate_new_reg (x, &offset);
1273 *loc = plus_constant (new, offset);
1280 new = instantiate_new_reg (XEXP (x, 0), &offset);
1283 new = plus_constant (new, offset);
1284 *loc = simplify_gen_binary (PLUS, GET_MODE (x), new, XEXP (x, 1));
1290 /* FIXME -- from old code */
1291 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
1292 we can commute the PLUS and SUBREG because pointers into the
1293 frame are well-behaved. */
1303 /* A subroutine of instantiate_virtual_regs_in_insn. Return true if X
1304 matches the predicate for insn CODE operand OPERAND. */
1307 safe_insn_predicate (int code, int operand, rtx x)
1309 const struct insn_operand_data *op_data;
1314 op_data = &insn_data[code].operand[operand];
1315 if (op_data->predicate == NULL)
1318 return op_data->predicate (x, op_data->mode);
1321 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1322 registers present inside of insn. The result will be a valid insn. */
1325 instantiate_virtual_regs_in_insn (rtx insn)
1327 HOST_WIDE_INT offset;
1329 bool any_change = false;
1330 rtx set, new, x, seq;
1332 /* There are some special cases to be handled first. */
1333 set = single_set (insn);
1336 /* We're allowed to assign to a virtual register. This is interpreted
1337 to mean that the underlying register gets assigned the inverse
1338 transformation. This is used, for example, in the handling of
1340 new = instantiate_new_reg (SET_DEST (set), &offset);
1345 for_each_rtx (&SET_SRC (set), instantiate_virtual_regs_in_rtx, NULL);
1346 x = simplify_gen_binary (PLUS, GET_MODE (new), SET_SRC (set),
1348 x = force_operand (x, new);
1350 emit_move_insn (new, x);
1355 emit_insn_before (seq, insn);
1360 /* Handle a straight copy from a virtual register by generating a
1361 new add insn. The difference between this and falling through
1362 to the generic case is avoiding a new pseudo and eliminating a
1363 move insn in the initial rtl stream. */
1364 new = instantiate_new_reg (SET_SRC (set), &offset);
1365 if (new && offset != 0
1366 && REG_P (SET_DEST (set))
1367 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1371 x = expand_simple_binop (GET_MODE (SET_DEST (set)), PLUS,
1372 new, GEN_INT (offset), SET_DEST (set),
1373 1, OPTAB_LIB_WIDEN);
1374 if (x != SET_DEST (set))
1375 emit_move_insn (SET_DEST (set), x);
1380 emit_insn_before (seq, insn);
1385 extract_insn (insn);
1386 insn_code = INSN_CODE (insn);
1388 /* Handle a plus involving a virtual register by determining if the
1389 operands remain valid if they're modified in place. */
1390 if (GET_CODE (SET_SRC (set)) == PLUS
1391 && recog_data.n_operands >= 3
1392 && recog_data.operand_loc[1] == &XEXP (SET_SRC (set), 0)
1393 && recog_data.operand_loc[2] == &XEXP (SET_SRC (set), 1)
1394 && GET_CODE (recog_data.operand[2]) == CONST_INT
1395 && (new = instantiate_new_reg (recog_data.operand[1], &offset)))
1397 offset += INTVAL (recog_data.operand[2]);
1399 /* If the sum is zero, then replace with a plain move. */
1401 && REG_P (SET_DEST (set))
1402 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1405 emit_move_insn (SET_DEST (set), new);
1409 emit_insn_before (seq, insn);
1414 x = gen_int_mode (offset, recog_data.operand_mode[2]);
1416 /* Using validate_change and apply_change_group here leaves
1417 recog_data in an invalid state. Since we know exactly what
1418 we want to check, do those two by hand. */
1419 if (safe_insn_predicate (insn_code, 1, new)
1420 && safe_insn_predicate (insn_code, 2, x))
1422 *recog_data.operand_loc[1] = recog_data.operand[1] = new;
1423 *recog_data.operand_loc[2] = recog_data.operand[2] = x;
1426 /* Fall through into the regular operand fixup loop in
1427 order to take care of operands other than 1 and 2. */
1433 extract_insn (insn);
1434 insn_code = INSN_CODE (insn);
1437 /* In the general case, we expect virtual registers to appear only in
1438 operands, and then only as either bare registers or inside memories. */
1439 for (i = 0; i < recog_data.n_operands; ++i)
1441 x = recog_data.operand[i];
1442 switch (GET_CODE (x))
1446 rtx addr = XEXP (x, 0);
1447 bool changed = false;
1449 for_each_rtx (&addr, instantiate_virtual_regs_in_rtx, &changed);
1454 x = replace_equiv_address (x, addr);
1455 /* It may happen that the address with the virtual reg
1456 was valid (e.g. based on the virtual stack reg, which might
1457 be acceptable to the predicates with all offsets), whereas
1458 the address now isn't anymore, for instance when the address
1459 is still offsetted, but the base reg isn't virtual-stack-reg
1460 anymore. Below we would do a force_reg on the whole operand,
1461 but this insn might actually only accept memory. Hence,
1462 before doing that last resort, try to reload the address into
1463 a register, so this operand stays a MEM. */
1464 if (!safe_insn_predicate (insn_code, i, x))
1466 addr = force_reg (GET_MODE (addr), addr);
1467 x = replace_equiv_address (x, addr);
1472 emit_insn_before (seq, insn);
1477 new = instantiate_new_reg (x, &offset);
1486 /* Careful, special mode predicates may have stuff in
1487 insn_data[insn_code].operand[i].mode that isn't useful
1488 to us for computing a new value. */
1489 /* ??? Recognize address_operand and/or "p" constraints
1490 to see if (plus new offset) is a valid before we put
1491 this through expand_simple_binop. */
1492 x = expand_simple_binop (GET_MODE (x), PLUS, new,
1493 GEN_INT (offset), NULL_RTX,
1494 1, OPTAB_LIB_WIDEN);
1497 emit_insn_before (seq, insn);
1502 new = instantiate_new_reg (SUBREG_REG (x), &offset);
1508 new = expand_simple_binop (GET_MODE (new), PLUS, new,
1509 GEN_INT (offset), NULL_RTX,
1510 1, OPTAB_LIB_WIDEN);
1513 emit_insn_before (seq, insn);
1515 x = simplify_gen_subreg (recog_data.operand_mode[i], new,
1516 GET_MODE (new), SUBREG_BYTE (x));
1523 /* At this point, X contains the new value for the operand.
1524 Validate the new value vs the insn predicate. Note that
1525 asm insns will have insn_code -1 here. */
1526 if (!safe_insn_predicate (insn_code, i, x))
1529 x = force_reg (insn_data[insn_code].operand[i].mode, x);
1533 emit_insn_before (seq, insn);
1536 *recog_data.operand_loc[i] = recog_data.operand[i] = x;
1542 /* Propagate operand changes into the duplicates. */
1543 for (i = 0; i < recog_data.n_dups; ++i)
1544 *recog_data.dup_loc[i]
1545 = copy_rtx (recog_data.operand[(unsigned)recog_data.dup_num[i]]);
1547 /* Force re-recognition of the instruction for validation. */
1548 INSN_CODE (insn) = -1;
1551 if (asm_noperands (PATTERN (insn)) >= 0)
1553 if (!check_asm_operands (PATTERN (insn)))
1555 error_for_asm (insn, "impossible constraint in %<asm%>");
1561 if (recog_memoized (insn) < 0)
1562 fatal_insn_not_found (insn);
1566 /* Subroutine of instantiate_decls. Given RTL representing a decl,
1567 do any instantiation required. */
1570 instantiate_decl_rtl (rtx x)
1577 /* If this is a CONCAT, recurse for the pieces. */
1578 if (GET_CODE (x) == CONCAT)
1580 instantiate_decl_rtl (XEXP (x, 0));
1581 instantiate_decl_rtl (XEXP (x, 1));
1585 /* If this is not a MEM, no need to do anything. Similarly if the
1586 address is a constant or a register that is not a virtual register. */
1591 if (CONSTANT_P (addr)
1593 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
1594 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
1597 for_each_rtx (&XEXP (x, 0), instantiate_virtual_regs_in_rtx, NULL);
1600 /* Helper for instantiate_decls called via walk_tree: Process all decls
1601 in the given DECL_VALUE_EXPR. */
1604 instantiate_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1610 if (DECL_P (t) && DECL_RTL_SET_P (t))
1611 instantiate_decl_rtl (DECL_RTL (t));
1616 /* Subroutine of instantiate_decls: Process all decls in the given
1617 BLOCK node and all its subblocks. */
1620 instantiate_decls_1 (tree let)
1624 for (t = BLOCK_VARS (let); t; t = TREE_CHAIN (t))
1626 if (DECL_RTL_SET_P (t))
1627 instantiate_decl_rtl (DECL_RTL (t));
1628 if (TREE_CODE (t) == VAR_DECL && DECL_HAS_VALUE_EXPR_P (t))
1630 tree v = DECL_VALUE_EXPR (t);
1631 walk_tree (&v, instantiate_expr, NULL, NULL);
1635 /* Process all subblocks. */
1636 for (t = BLOCK_SUBBLOCKS (let); t; t = BLOCK_CHAIN (t))
1637 instantiate_decls_1 (t);
1640 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1641 all virtual registers in their DECL_RTL's. */
1644 instantiate_decls (tree fndecl)
1648 /* Process all parameters of the function. */
1649 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = TREE_CHAIN (decl))
1651 instantiate_decl_rtl (DECL_RTL (decl));
1652 instantiate_decl_rtl (DECL_INCOMING_RTL (decl));
1653 if (DECL_HAS_VALUE_EXPR_P (decl))
1655 tree v = DECL_VALUE_EXPR (decl);
1656 walk_tree (&v, instantiate_expr, NULL, NULL);
1660 /* Now process all variables defined in the function or its subblocks. */
1661 instantiate_decls_1 (DECL_INITIAL (fndecl));
1664 /* Pass through the INSNS of function FNDECL and convert virtual register
1665 references to hard register references. */
1668 instantiate_virtual_regs (void)
1672 /* Compute the offsets to use for this function. */
1673 in_arg_offset = FIRST_PARM_OFFSET (current_function_decl);
1674 var_offset = STARTING_FRAME_OFFSET;
1675 dynamic_offset = STACK_DYNAMIC_OFFSET (current_function_decl);
1676 out_arg_offset = STACK_POINTER_OFFSET;
1677 #ifdef FRAME_POINTER_CFA_OFFSET
1678 cfa_offset = FRAME_POINTER_CFA_OFFSET (current_function_decl);
1680 cfa_offset = ARG_POINTER_CFA_OFFSET (current_function_decl);
1683 /* Initialize recognition, indicating that volatile is OK. */
1686 /* Scan through all the insns, instantiating every virtual register still
1688 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
1691 /* These patterns in the instruction stream can never be recognized.
1692 Fortunately, they shouldn't contain virtual registers either. */
1693 if (GET_CODE (PATTERN (insn)) == USE
1694 || GET_CODE (PATTERN (insn)) == CLOBBER
1695 || GET_CODE (PATTERN (insn)) == ADDR_VEC
1696 || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC
1697 || GET_CODE (PATTERN (insn)) == ASM_INPUT)
1700 instantiate_virtual_regs_in_insn (insn);
1702 if (INSN_DELETED_P (insn))
1705 for_each_rtx (®_NOTES (insn), instantiate_virtual_regs_in_rtx, NULL);
1707 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
1708 if (GET_CODE (insn) == CALL_INSN)
1709 for_each_rtx (&CALL_INSN_FUNCTION_USAGE (insn),
1710 instantiate_virtual_regs_in_rtx, NULL);
1713 /* Instantiate the virtual registers in the DECLs for debugging purposes. */
1714 instantiate_decls (current_function_decl);
1716 targetm.instantiate_decls ();
1718 /* Indicate that, from now on, assign_stack_local should use
1719 frame_pointer_rtx. */
1720 virtuals_instantiated = 1;
1724 struct rtl_opt_pass pass_instantiate_virtual_regs =
1730 instantiate_virtual_regs, /* execute */
1733 0, /* static_pass_number */
1735 0, /* properties_required */
1736 0, /* properties_provided */
1737 0, /* properties_destroyed */
1738 0, /* todo_flags_start */
1739 TODO_dump_func /* todo_flags_finish */
1744 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
1745 This means a type for which function calls must pass an address to the
1746 function or get an address back from the function.
1747 EXP may be a type node or an expression (whose type is tested). */
1750 aggregate_value_p (const_tree exp, const_tree fntype)
1752 int i, regno, nregs;
1755 const_tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
1757 /* DECL node associated with FNTYPE when relevant, which we might need to
1758 check for by-invisible-reference returns, typically for CALL_EXPR input
1760 const_tree fndecl = NULL_TREE;
1763 switch (TREE_CODE (fntype))
1766 fndecl = get_callee_fndecl (fntype);
1767 fntype = fndecl ? TREE_TYPE (fndecl) : 0;
1771 fntype = TREE_TYPE (fndecl);
1776 case IDENTIFIER_NODE:
1780 /* We don't expect other rtl types here. */
1784 if (TREE_CODE (type) == VOID_TYPE)
1787 /* If the front end has decided that this needs to be passed by
1788 reference, do so. */
1789 if ((TREE_CODE (exp) == PARM_DECL || TREE_CODE (exp) == RESULT_DECL)
1790 && DECL_BY_REFERENCE (exp))
1793 /* If the EXPression is a CALL_EXPR, honor DECL_BY_REFERENCE set on the
1794 called function RESULT_DECL, meaning the function returns in memory by
1795 invisible reference. This check lets front-ends not set TREE_ADDRESSABLE
1796 on the function type, which used to be the way to request such a return
1797 mechanism but might now be causing troubles at gimplification time if
1798 temporaries with the function type need to be created. */
1799 if (TREE_CODE (exp) == CALL_EXPR && fndecl && DECL_RESULT (fndecl)
1800 && DECL_BY_REFERENCE (DECL_RESULT (fndecl)))
1803 if (targetm.calls.return_in_memory (type, fntype))
1805 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
1806 and thus can't be returned in registers. */
1807 if (TREE_ADDRESSABLE (type))
1809 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
1811 /* Make sure we have suitable call-clobbered regs to return
1812 the value in; if not, we must return it in memory. */
1813 reg = hard_function_value (type, 0, fntype, 0);
1815 /* If we have something other than a REG (e.g. a PARALLEL), then assume
1820 regno = REGNO (reg);
1821 nregs = hard_regno_nregs[regno][TYPE_MODE (type)];
1822 for (i = 0; i < nregs; i++)
1823 if (! call_used_regs[regno + i])
1828 /* Return true if we should assign DECL a pseudo register; false if it
1829 should live on the local stack. */
1832 use_register_for_decl (const_tree decl)
1834 if (!targetm.calls.allocate_stack_slots_for_args())
1837 /* Honor volatile. */
1838 if (TREE_SIDE_EFFECTS (decl))
1841 /* Honor addressability. */
1842 if (TREE_ADDRESSABLE (decl))
1845 /* Only register-like things go in registers. */
1846 if (DECL_MODE (decl) == BLKmode)
1849 /* If -ffloat-store specified, don't put explicit float variables
1851 /* ??? This should be checked after DECL_ARTIFICIAL, but tree-ssa
1852 propagates values across these stores, and it probably shouldn't. */
1853 if (flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)))
1856 /* If we're not interested in tracking debugging information for
1857 this decl, then we can certainly put it in a register. */
1858 if (DECL_IGNORED_P (decl))
1861 return (optimize || DECL_REGISTER (decl));
1864 /* Return true if TYPE should be passed by invisible reference. */
1867 pass_by_reference (CUMULATIVE_ARGS *ca, enum machine_mode mode,
1868 tree type, bool named_arg)
1872 /* If this type contains non-trivial constructors, then it is
1873 forbidden for the middle-end to create any new copies. */
1874 if (TREE_ADDRESSABLE (type))
1877 /* GCC post 3.4 passes *all* variable sized types by reference. */
1878 if (!TYPE_SIZE (type) || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
1882 return targetm.calls.pass_by_reference (ca, mode, type, named_arg);
1885 /* Return true if TYPE, which is passed by reference, should be callee
1886 copied instead of caller copied. */
1889 reference_callee_copied (CUMULATIVE_ARGS *ca, enum machine_mode mode,
1890 tree type, bool named_arg)
1892 if (type && TREE_ADDRESSABLE (type))
1894 return targetm.calls.callee_copies (ca, mode, type, named_arg);
1897 /* Structures to communicate between the subroutines of assign_parms.
1898 The first holds data persistent across all parameters, the second
1899 is cleared out for each parameter. */
1901 struct assign_parm_data_all
1903 CUMULATIVE_ARGS args_so_far;
1904 struct args_size stack_args_size;
1905 tree function_result_decl;
1907 rtx first_conversion_insn;
1908 rtx last_conversion_insn;
1909 HOST_WIDE_INT pretend_args_size;
1910 HOST_WIDE_INT extra_pretend_bytes;
1911 int reg_parm_stack_space;
1914 struct assign_parm_data_one
1920 enum machine_mode nominal_mode;
1921 enum machine_mode passed_mode;
1922 enum machine_mode promoted_mode;
1923 struct locate_and_pad_arg_data locate;
1925 BOOL_BITFIELD named_arg : 1;
1926 BOOL_BITFIELD passed_pointer : 1;
1927 BOOL_BITFIELD on_stack : 1;
1928 BOOL_BITFIELD loaded_in_reg : 1;
1931 /* A subroutine of assign_parms. Initialize ALL. */
1934 assign_parms_initialize_all (struct assign_parm_data_all *all)
1938 memset (all, 0, sizeof (*all));
1940 fntype = TREE_TYPE (current_function_decl);
1942 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
1943 INIT_CUMULATIVE_INCOMING_ARGS (all->args_so_far, fntype, NULL_RTX);
1945 INIT_CUMULATIVE_ARGS (all->args_so_far, fntype, NULL_RTX,
1946 current_function_decl, -1);
1949 #ifdef REG_PARM_STACK_SPACE
1950 all->reg_parm_stack_space = REG_PARM_STACK_SPACE (current_function_decl);
1954 /* If ARGS contains entries with complex types, split the entry into two
1955 entries of the component type. Return a new list of substitutions are
1956 needed, else the old list. */
1959 split_complex_args (tree args)
1963 /* Before allocating memory, check for the common case of no complex. */
1964 for (p = args; p; p = TREE_CHAIN (p))
1966 tree type = TREE_TYPE (p);
1967 if (TREE_CODE (type) == COMPLEX_TYPE
1968 && targetm.calls.split_complex_arg (type))
1974 args = copy_list (args);
1976 for (p = args; p; p = TREE_CHAIN (p))
1978 tree type = TREE_TYPE (p);
1979 if (TREE_CODE (type) == COMPLEX_TYPE
1980 && targetm.calls.split_complex_arg (type))
1983 tree subtype = TREE_TYPE (type);
1984 bool addressable = TREE_ADDRESSABLE (p);
1986 /* Rewrite the PARM_DECL's type with its component. */
1987 TREE_TYPE (p) = subtype;
1988 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
1989 DECL_MODE (p) = VOIDmode;
1990 DECL_SIZE (p) = NULL;
1991 DECL_SIZE_UNIT (p) = NULL;
1992 /* If this arg must go in memory, put it in a pseudo here.
1993 We can't allow it to go in memory as per normal parms,
1994 because the usual place might not have the imag part
1995 adjacent to the real part. */
1996 DECL_ARTIFICIAL (p) = addressable;
1997 DECL_IGNORED_P (p) = addressable;
1998 TREE_ADDRESSABLE (p) = 0;
2001 /* Build a second synthetic decl. */
2002 decl = build_decl (PARM_DECL, NULL_TREE, subtype);
2003 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
2004 DECL_ARTIFICIAL (decl) = addressable;
2005 DECL_IGNORED_P (decl) = addressable;
2006 layout_decl (decl, 0);
2008 /* Splice it in; skip the new decl. */
2009 TREE_CHAIN (decl) = TREE_CHAIN (p);
2010 TREE_CHAIN (p) = decl;
2018 /* A subroutine of assign_parms. Adjust the parameter list to incorporate
2019 the hidden struct return argument, and (abi willing) complex args.
2020 Return the new parameter list. */
2023 assign_parms_augmented_arg_list (struct assign_parm_data_all *all)
2025 tree fndecl = current_function_decl;
2026 tree fntype = TREE_TYPE (fndecl);
2027 tree fnargs = DECL_ARGUMENTS (fndecl);
2029 /* If struct value address is treated as the first argument, make it so. */
2030 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
2031 && ! cfun->returns_pcc_struct
2032 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
2034 tree type = build_pointer_type (TREE_TYPE (fntype));
2037 decl = build_decl (PARM_DECL, NULL_TREE, type);
2038 DECL_ARG_TYPE (decl) = type;
2039 DECL_ARTIFICIAL (decl) = 1;
2040 DECL_IGNORED_P (decl) = 1;
2042 TREE_CHAIN (decl) = fnargs;
2044 all->function_result_decl = decl;
2047 all->orig_fnargs = fnargs;
2049 /* If the target wants to split complex arguments into scalars, do so. */
2050 if (targetm.calls.split_complex_arg)
2051 fnargs = split_complex_args (fnargs);
2056 /* A subroutine of assign_parms. Examine PARM and pull out type and mode
2057 data for the parameter. Incorporate ABI specifics such as pass-by-
2058 reference and type promotion. */
2061 assign_parm_find_data_types (struct assign_parm_data_all *all, tree parm,
2062 struct assign_parm_data_one *data)
2064 tree nominal_type, passed_type;
2065 enum machine_mode nominal_mode, passed_mode, promoted_mode;
2067 memset (data, 0, sizeof (*data));
2069 /* NAMED_ARG is a misnomer. We really mean 'non-variadic'. */
2071 data->named_arg = 1; /* No variadic parms. */
2072 else if (TREE_CHAIN (parm))
2073 data->named_arg = 1; /* Not the last non-variadic parm. */
2074 else if (targetm.calls.strict_argument_naming (&all->args_so_far))
2075 data->named_arg = 1; /* Only variadic ones are unnamed. */
2077 data->named_arg = 0; /* Treat as variadic. */
2079 nominal_type = TREE_TYPE (parm);
2080 passed_type = DECL_ARG_TYPE (parm);
2082 /* Look out for errors propagating this far. Also, if the parameter's
2083 type is void then its value doesn't matter. */
2084 if (TREE_TYPE (parm) == error_mark_node
2085 /* This can happen after weird syntax errors
2086 or if an enum type is defined among the parms. */
2087 || TREE_CODE (parm) != PARM_DECL
2088 || passed_type == NULL
2089 || VOID_TYPE_P (nominal_type))
2091 nominal_type = passed_type = void_type_node;
2092 nominal_mode = passed_mode = promoted_mode = VOIDmode;
2096 /* Find mode of arg as it is passed, and mode of arg as it should be
2097 during execution of this function. */
2098 passed_mode = TYPE_MODE (passed_type);
2099 nominal_mode = TYPE_MODE (nominal_type);
2101 /* If the parm is to be passed as a transparent union, use the type of
2102 the first field for the tests below. We have already verified that
2103 the modes are the same. */
2104 if (TREE_CODE (passed_type) == UNION_TYPE
2105 && TYPE_TRANSPARENT_UNION (passed_type))
2106 passed_type = TREE_TYPE (TYPE_FIELDS (passed_type));
2108 /* See if this arg was passed by invisible reference. */
2109 if (pass_by_reference (&all->args_so_far, passed_mode,
2110 passed_type, data->named_arg))
2112 passed_type = nominal_type = build_pointer_type (passed_type);
2113 data->passed_pointer = true;
2114 passed_mode = nominal_mode = Pmode;
2117 /* Find mode as it is passed by the ABI. */
2118 promoted_mode = passed_mode;
2119 if (targetm.calls.promote_function_args (TREE_TYPE (current_function_decl)))
2121 int unsignedp = TYPE_UNSIGNED (passed_type);
2122 promoted_mode = promote_mode (passed_type, promoted_mode,
2127 data->nominal_type = nominal_type;
2128 data->passed_type = passed_type;
2129 data->nominal_mode = nominal_mode;
2130 data->passed_mode = passed_mode;
2131 data->promoted_mode = promoted_mode;
2134 /* A subroutine of assign_parms. Invoke setup_incoming_varargs. */
2137 assign_parms_setup_varargs (struct assign_parm_data_all *all,
2138 struct assign_parm_data_one *data, bool no_rtl)
2140 int varargs_pretend_bytes = 0;
2142 targetm.calls.setup_incoming_varargs (&all->args_so_far,
2143 data->promoted_mode,
2145 &varargs_pretend_bytes, no_rtl);
2147 /* If the back-end has requested extra stack space, record how much is
2148 needed. Do not change pretend_args_size otherwise since it may be
2149 nonzero from an earlier partial argument. */
2150 if (varargs_pretend_bytes > 0)
2151 all->pretend_args_size = varargs_pretend_bytes;
2154 /* A subroutine of assign_parms. Set DATA->ENTRY_PARM corresponding to
2155 the incoming location of the current parameter. */
2158 assign_parm_find_entry_rtl (struct assign_parm_data_all *all,
2159 struct assign_parm_data_one *data)
2161 HOST_WIDE_INT pretend_bytes = 0;
2165 if (data->promoted_mode == VOIDmode)
2167 data->entry_parm = data->stack_parm = const0_rtx;
2171 #ifdef FUNCTION_INCOMING_ARG
2172 entry_parm = FUNCTION_INCOMING_ARG (all->args_so_far, data->promoted_mode,
2173 data->passed_type, data->named_arg);
2175 entry_parm = FUNCTION_ARG (all->args_so_far, data->promoted_mode,
2176 data->passed_type, data->named_arg);
2179 if (entry_parm == 0)
2180 data->promoted_mode = data->passed_mode;
2182 /* Determine parm's home in the stack, in case it arrives in the stack
2183 or we should pretend it did. Compute the stack position and rtx where
2184 the argument arrives and its size.
2186 There is one complexity here: If this was a parameter that would
2187 have been passed in registers, but wasn't only because it is
2188 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2189 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2190 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of 0
2191 as it was the previous time. */
2192 in_regs = entry_parm != 0;
2193 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2196 if (!in_regs && !data->named_arg)
2198 if (targetm.calls.pretend_outgoing_varargs_named (&all->args_so_far))
2201 #ifdef FUNCTION_INCOMING_ARG
2202 tem = FUNCTION_INCOMING_ARG (all->args_so_far, data->promoted_mode,
2203 data->passed_type, true);
2205 tem = FUNCTION_ARG (all->args_so_far, data->promoted_mode,
2206 data->passed_type, true);
2208 in_regs = tem != NULL;
2212 /* If this parameter was passed both in registers and in the stack, use
2213 the copy on the stack. */
2214 if (targetm.calls.must_pass_in_stack (data->promoted_mode,
2222 partial = targetm.calls.arg_partial_bytes (&all->args_so_far,
2223 data->promoted_mode,
2226 data->partial = partial;
2228 /* The caller might already have allocated stack space for the
2229 register parameters. */
2230 if (partial != 0 && all->reg_parm_stack_space == 0)
2232 /* Part of this argument is passed in registers and part
2233 is passed on the stack. Ask the prologue code to extend
2234 the stack part so that we can recreate the full value.
2236 PRETEND_BYTES is the size of the registers we need to store.
2237 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
2238 stack space that the prologue should allocate.
2240 Internally, gcc assumes that the argument pointer is aligned
2241 to STACK_BOUNDARY bits. This is used both for alignment
2242 optimizations (see init_emit) and to locate arguments that are
2243 aligned to more than PARM_BOUNDARY bits. We must preserve this
2244 invariant by rounding CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to
2245 a stack boundary. */
2247 /* We assume at most one partial arg, and it must be the first
2248 argument on the stack. */
2249 gcc_assert (!all->extra_pretend_bytes && !all->pretend_args_size);
2251 pretend_bytes = partial;
2252 all->pretend_args_size = CEIL_ROUND (pretend_bytes, STACK_BYTES);
2254 /* We want to align relative to the actual stack pointer, so
2255 don't include this in the stack size until later. */
2256 all->extra_pretend_bytes = all->pretend_args_size;
2260 locate_and_pad_parm (data->promoted_mode, data->passed_type, in_regs,
2261 entry_parm ? data->partial : 0, current_function_decl,
2262 &all->stack_args_size, &data->locate);
2264 /* Adjust offsets to include the pretend args. */
2265 pretend_bytes = all->extra_pretend_bytes - pretend_bytes;
2266 data->locate.slot_offset.constant += pretend_bytes;
2267 data->locate.offset.constant += pretend_bytes;
2269 data->entry_parm = entry_parm;
2272 /* A subroutine of assign_parms. If there is actually space on the stack
2273 for this parm, count it in stack_args_size and return true. */
2276 assign_parm_is_stack_parm (struct assign_parm_data_all *all,
2277 struct assign_parm_data_one *data)
2279 /* Trivially true if we've no incoming register. */
2280 if (data->entry_parm == NULL)
2282 /* Also true if we're partially in registers and partially not,
2283 since we've arranged to drop the entire argument on the stack. */
2284 else if (data->partial != 0)
2286 /* Also true if the target says that it's passed in both registers
2287 and on the stack. */
2288 else if (GET_CODE (data->entry_parm) == PARALLEL
2289 && XEXP (XVECEXP (data->entry_parm, 0, 0), 0) == NULL_RTX)
2291 /* Also true if the target says that there's stack allocated for
2292 all register parameters. */
2293 else if (all->reg_parm_stack_space > 0)
2295 /* Otherwise, no, this parameter has no ABI defined stack slot. */
2299 all->stack_args_size.constant += data->locate.size.constant;
2300 if (data->locate.size.var)
2301 ADD_PARM_SIZE (all->stack_args_size, data->locate.size.var);
2306 /* A subroutine of assign_parms. Given that this parameter is allocated
2307 stack space by the ABI, find it. */
2310 assign_parm_find_stack_rtl (tree parm, struct assign_parm_data_one *data)
2312 rtx offset_rtx, stack_parm;
2313 unsigned int align, boundary;
2315 /* If we're passing this arg using a reg, make its stack home the
2316 aligned stack slot. */
2317 if (data->entry_parm)
2318 offset_rtx = ARGS_SIZE_RTX (data->locate.slot_offset);
2320 offset_rtx = ARGS_SIZE_RTX (data->locate.offset);
2322 stack_parm = crtl->args.internal_arg_pointer;
2323 if (offset_rtx != const0_rtx)
2324 stack_parm = gen_rtx_PLUS (Pmode, stack_parm, offset_rtx);
2325 stack_parm = gen_rtx_MEM (data->promoted_mode, stack_parm);
2327 set_mem_attributes (stack_parm, parm, 1);
2329 boundary = data->locate.boundary;
2330 align = BITS_PER_UNIT;
2332 /* If we're padding upward, we know that the alignment of the slot
2333 is FUNCTION_ARG_BOUNDARY. If we're using slot_offset, we're
2334 intentionally forcing upward padding. Otherwise we have to come
2335 up with a guess at the alignment based on OFFSET_RTX. */
2336 if (data->locate.where_pad != downward || data->entry_parm)
2338 else if (GET_CODE (offset_rtx) == CONST_INT)
2340 align = INTVAL (offset_rtx) * BITS_PER_UNIT | boundary;
2341 align = align & -align;
2343 set_mem_align (stack_parm, align);
2345 if (data->entry_parm)
2346 set_reg_attrs_for_parm (data->entry_parm, stack_parm);
2348 data->stack_parm = stack_parm;
2351 /* A subroutine of assign_parms. Adjust DATA->ENTRY_RTL such that it's
2352 always valid and contiguous. */
2355 assign_parm_adjust_entry_rtl (struct assign_parm_data_one *data)
2357 rtx entry_parm = data->entry_parm;
2358 rtx stack_parm = data->stack_parm;
2360 /* If this parm was passed part in regs and part in memory, pretend it
2361 arrived entirely in memory by pushing the register-part onto the stack.
2362 In the special case of a DImode or DFmode that is split, we could put
2363 it together in a pseudoreg directly, but for now that's not worth
2365 if (data->partial != 0)
2367 /* Handle calls that pass values in multiple non-contiguous
2368 locations. The Irix 6 ABI has examples of this. */
2369 if (GET_CODE (entry_parm) == PARALLEL)
2370 emit_group_store (validize_mem (stack_parm), entry_parm,
2372 int_size_in_bytes (data->passed_type));
2375 gcc_assert (data->partial % UNITS_PER_WORD == 0);
2376 move_block_from_reg (REGNO (entry_parm), validize_mem (stack_parm),
2377 data->partial / UNITS_PER_WORD);
2380 entry_parm = stack_parm;
2383 /* If we didn't decide this parm came in a register, by default it came
2385 else if (entry_parm == NULL)
2386 entry_parm = stack_parm;
2388 /* When an argument is passed in multiple locations, we can't make use
2389 of this information, but we can save some copying if the whole argument
2390 is passed in a single register. */
2391 else if (GET_CODE (entry_parm) == PARALLEL
2392 && data->nominal_mode != BLKmode
2393 && data->passed_mode != BLKmode)
2395 size_t i, len = XVECLEN (entry_parm, 0);
2397 for (i = 0; i < len; i++)
2398 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
2399 && REG_P (XEXP (XVECEXP (entry_parm, 0, i), 0))
2400 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
2401 == data->passed_mode)
2402 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
2404 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
2409 data->entry_parm = entry_parm;
2412 /* A subroutine of assign_parms. Reconstitute any values which were
2413 passed in multiple registers and would fit in a single register. */
2416 assign_parm_remove_parallels (struct assign_parm_data_one *data)
2418 rtx entry_parm = data->entry_parm;
2420 /* Convert the PARALLEL to a REG of the same mode as the parallel.
2421 This can be done with register operations rather than on the
2422 stack, even if we will store the reconstituted parameter on the
2424 if (GET_CODE (entry_parm) == PARALLEL && GET_MODE (entry_parm) != BLKmode)
2426 rtx parmreg = gen_reg_rtx (GET_MODE (entry_parm));
2427 emit_group_store (parmreg, entry_parm, NULL_TREE,
2428 GET_MODE_SIZE (GET_MODE (entry_parm)));
2429 entry_parm = parmreg;
2432 data->entry_parm = entry_parm;
2435 /* A subroutine of assign_parms. Adjust DATA->STACK_RTL such that it's
2436 always valid and properly aligned. */
2439 assign_parm_adjust_stack_rtl (struct assign_parm_data_one *data)
2441 rtx stack_parm = data->stack_parm;
2443 /* If we can't trust the parm stack slot to be aligned enough for its
2444 ultimate type, don't use that slot after entry. We'll make another
2445 stack slot, if we need one. */
2447 && ((STRICT_ALIGNMENT
2448 && GET_MODE_ALIGNMENT (data->nominal_mode) > MEM_ALIGN (stack_parm))
2449 || (data->nominal_type
2450 && TYPE_ALIGN (data->nominal_type) > MEM_ALIGN (stack_parm)
2451 && MEM_ALIGN (stack_parm) < PREFERRED_STACK_BOUNDARY)))
2454 /* If parm was passed in memory, and we need to convert it on entry,
2455 don't store it back in that same slot. */
2456 else if (data->entry_parm == stack_parm
2457 && data->nominal_mode != BLKmode
2458 && data->nominal_mode != data->passed_mode)
2461 /* If stack protection is in effect for this function, don't leave any
2462 pointers in their passed stack slots. */
2463 else if (crtl->stack_protect_guard
2464 && (flag_stack_protect == 2
2465 || data->passed_pointer
2466 || POINTER_TYPE_P (data->nominal_type)))
2469 data->stack_parm = stack_parm;
2472 /* A subroutine of assign_parms. Return true if the current parameter
2473 should be stored as a BLKmode in the current frame. */
2476 assign_parm_setup_block_p (struct assign_parm_data_one *data)
2478 if (data->nominal_mode == BLKmode)
2480 if (GET_MODE (data->entry_parm) == BLKmode)
2483 #ifdef BLOCK_REG_PADDING
2484 /* Only assign_parm_setup_block knows how to deal with register arguments
2485 that are padded at the least significant end. */
2486 if (REG_P (data->entry_parm)
2487 && GET_MODE_SIZE (data->promoted_mode) < UNITS_PER_WORD
2488 && (BLOCK_REG_PADDING (data->passed_mode, data->passed_type, 1)
2489 == (BYTES_BIG_ENDIAN ? upward : downward)))
2496 /* A subroutine of assign_parms. Arrange for the parameter to be
2497 present and valid in DATA->STACK_RTL. */
2500 assign_parm_setup_block (struct assign_parm_data_all *all,
2501 tree parm, struct assign_parm_data_one *data)
2503 rtx entry_parm = data->entry_parm;
2504 rtx stack_parm = data->stack_parm;
2506 HOST_WIDE_INT size_stored;
2508 if (GET_CODE (entry_parm) == PARALLEL)
2509 entry_parm = emit_group_move_into_temps (entry_parm);
2511 size = int_size_in_bytes (data->passed_type);
2512 size_stored = CEIL_ROUND (size, UNITS_PER_WORD);
2513 if (stack_parm == 0)
2515 DECL_ALIGN (parm) = MAX (DECL_ALIGN (parm), BITS_PER_WORD);
2516 stack_parm = assign_stack_local (BLKmode, size_stored,
2518 if (GET_MODE_SIZE (GET_MODE (entry_parm)) == size)
2519 PUT_MODE (stack_parm, GET_MODE (entry_parm));
2520 set_mem_attributes (stack_parm, parm, 1);
2523 /* If a BLKmode arrives in registers, copy it to a stack slot. Handle
2524 calls that pass values in multiple non-contiguous locations. */
2525 if (REG_P (entry_parm) || GET_CODE (entry_parm) == PARALLEL)
2529 /* Note that we will be storing an integral number of words.
2530 So we have to be careful to ensure that we allocate an
2531 integral number of words. We do this above when we call
2532 assign_stack_local if space was not allocated in the argument
2533 list. If it was, this will not work if PARM_BOUNDARY is not
2534 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2535 if it becomes a problem. Exception is when BLKmode arrives
2536 with arguments not conforming to word_mode. */
2538 if (data->stack_parm == 0)
2540 else if (GET_CODE (entry_parm) == PARALLEL)
2543 gcc_assert (!size || !(PARM_BOUNDARY % BITS_PER_WORD));
2545 mem = validize_mem (stack_parm);
2547 /* Handle values in multiple non-contiguous locations. */
2548 if (GET_CODE (entry_parm) == PARALLEL)
2550 push_to_sequence2 (all->first_conversion_insn,
2551 all->last_conversion_insn);
2552 emit_group_store (mem, entry_parm, data->passed_type, size);
2553 all->first_conversion_insn = get_insns ();
2554 all->last_conversion_insn = get_last_insn ();
2561 /* If SIZE is that of a mode no bigger than a word, just use
2562 that mode's store operation. */
2563 else if (size <= UNITS_PER_WORD)
2565 enum machine_mode mode
2566 = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
2569 #ifdef BLOCK_REG_PADDING
2570 && (size == UNITS_PER_WORD
2571 || (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2572 != (BYTES_BIG_ENDIAN ? upward : downward)))
2578 /* We are really truncating a word_mode value containing
2579 SIZE bytes into a value of mode MODE. If such an
2580 operation requires no actual instructions, we can refer
2581 to the value directly in mode MODE, otherwise we must
2582 start with the register in word_mode and explicitly
2584 if (TRULY_NOOP_TRUNCATION (size * BITS_PER_UNIT, BITS_PER_WORD))
2585 reg = gen_rtx_REG (mode, REGNO (entry_parm));
2588 reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
2589 reg = convert_to_mode (mode, copy_to_reg (reg), 1);
2591 emit_move_insn (change_address (mem, mode, 0), reg);
2594 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
2595 machine must be aligned to the left before storing
2596 to memory. Note that the previous test doesn't
2597 handle all cases (e.g. SIZE == 3). */
2598 else if (size != UNITS_PER_WORD
2599 #ifdef BLOCK_REG_PADDING
2600 && (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2608 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
2609 rtx reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
2611 x = expand_shift (LSHIFT_EXPR, word_mode, reg,
2612 build_int_cst (NULL_TREE, by),
2614 tem = change_address (mem, word_mode, 0);
2615 emit_move_insn (tem, x);
2618 move_block_from_reg (REGNO (entry_parm), mem,
2619 size_stored / UNITS_PER_WORD);
2622 move_block_from_reg (REGNO (entry_parm), mem,
2623 size_stored / UNITS_PER_WORD);
2625 else if (data->stack_parm == 0)
2627 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2628 emit_block_move (stack_parm, data->entry_parm, GEN_INT (size),
2630 all->first_conversion_insn = get_insns ();
2631 all->last_conversion_insn = get_last_insn ();
2635 data->stack_parm = stack_parm;
2636 SET_DECL_RTL (parm, stack_parm);
2639 /* A subroutine of assign_parms. Allocate a pseudo to hold the current
2640 parameter. Get it there. Perform all ABI specified conversions. */
2643 assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm,
2644 struct assign_parm_data_one *data)
2647 enum machine_mode promoted_nominal_mode;
2648 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (parm));
2649 bool did_conversion = false;
2651 /* Store the parm in a pseudoregister during the function, but we may
2652 need to do it in a wider mode. */
2654 /* This is not really promoting for a call. However we need to be
2655 consistent with assign_parm_find_data_types and expand_expr_real_1. */
2656 promoted_nominal_mode
2657 = promote_mode (data->nominal_type, data->nominal_mode, &unsignedp, 1);
2659 parmreg = gen_reg_rtx (promoted_nominal_mode);
2661 if (!DECL_ARTIFICIAL (parm))
2662 mark_user_reg (parmreg);
2664 /* If this was an item that we received a pointer to,
2665 set DECL_RTL appropriately. */
2666 if (data->passed_pointer)
2668 rtx x = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data->passed_type)), parmreg);
2669 set_mem_attributes (x, parm, 1);
2670 SET_DECL_RTL (parm, x);
2673 SET_DECL_RTL (parm, parmreg);
2675 assign_parm_remove_parallels (data);
2677 /* Copy the value into the register. */
2678 if (data->nominal_mode != data->passed_mode
2679 || promoted_nominal_mode != data->promoted_mode)
2683 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
2684 mode, by the caller. We now have to convert it to
2685 NOMINAL_MODE, if different. However, PARMREG may be in
2686 a different mode than NOMINAL_MODE if it is being stored
2689 If ENTRY_PARM is a hard register, it might be in a register
2690 not valid for operating in its mode (e.g., an odd-numbered
2691 register for a DFmode). In that case, moves are the only
2692 thing valid, so we can't do a convert from there. This
2693 occurs when the calling sequence allow such misaligned
2696 In addition, the conversion may involve a call, which could
2697 clobber parameters which haven't been copied to pseudo
2698 registers yet. Therefore, we must first copy the parm to
2699 a pseudo reg here, and save the conversion until after all
2700 parameters have been moved. */
2702 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
2704 emit_move_insn (tempreg, validize_mem (data->entry_parm));
2706 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2707 tempreg = convert_to_mode (data->nominal_mode, tempreg, unsignedp);
2709 if (GET_CODE (tempreg) == SUBREG
2710 && GET_MODE (tempreg) == data->nominal_mode
2711 && REG_P (SUBREG_REG (tempreg))
2712 && data->nominal_mode == data->passed_mode
2713 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (data->entry_parm)
2714 && GET_MODE_SIZE (GET_MODE (tempreg))
2715 < GET_MODE_SIZE (GET_MODE (data->entry_parm)))
2717 /* The argument is already sign/zero extended, so note it
2719 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
2720 SUBREG_PROMOTED_UNSIGNED_SET (tempreg, unsignedp);
2723 /* TREE_USED gets set erroneously during expand_assignment. */
2724 save_tree_used = TREE_USED (parm);
2725 expand_assignment (parm, make_tree (data->nominal_type, tempreg), false);
2726 TREE_USED (parm) = save_tree_used;
2727 all->first_conversion_insn = get_insns ();
2728 all->last_conversion_insn = get_last_insn ();
2731 did_conversion = true;
2734 emit_move_insn (parmreg, validize_mem (data->entry_parm));
2736 /* If we were passed a pointer but the actual value can safely live
2737 in a register, put it in one. */
2738 if (data->passed_pointer
2739 && TYPE_MODE (TREE_TYPE (parm)) != BLKmode
2740 /* If by-reference argument was promoted, demote it. */
2741 && (TYPE_MODE (TREE_TYPE (parm)) != GET_MODE (DECL_RTL (parm))
2742 || use_register_for_decl (parm)))
2744 /* We can't use nominal_mode, because it will have been set to
2745 Pmode above. We must use the actual mode of the parm. */
2746 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
2747 mark_user_reg (parmreg);
2749 if (GET_MODE (parmreg) != GET_MODE (DECL_RTL (parm)))
2751 rtx tempreg = gen_reg_rtx (GET_MODE (DECL_RTL (parm)));
2752 int unsigned_p = TYPE_UNSIGNED (TREE_TYPE (parm));
2754 push_to_sequence2 (all->first_conversion_insn,
2755 all->last_conversion_insn);
2756 emit_move_insn (tempreg, DECL_RTL (parm));
2757 tempreg = convert_to_mode (GET_MODE (parmreg), tempreg, unsigned_p);
2758 emit_move_insn (parmreg, tempreg);
2759 all->first_conversion_insn = get_insns ();
2760 all->last_conversion_insn = get_last_insn ();
2763 did_conversion = true;
2766 emit_move_insn (parmreg, DECL_RTL (parm));
2768 SET_DECL_RTL (parm, parmreg);
2770 /* STACK_PARM is the pointer, not the parm, and PARMREG is
2772 data->stack_parm = NULL;
2775 /* Mark the register as eliminable if we did no conversion and it was
2776 copied from memory at a fixed offset, and the arg pointer was not
2777 copied to a pseudo-reg. If the arg pointer is a pseudo reg or the
2778 offset formed an invalid address, such memory-equivalences as we
2779 make here would screw up life analysis for it. */
2780 if (data->nominal_mode == data->passed_mode
2782 && data->stack_parm != 0
2783 && MEM_P (data->stack_parm)
2784 && data->locate.offset.var == 0
2785 && reg_mentioned_p (virtual_incoming_args_rtx,
2786 XEXP (data->stack_parm, 0)))
2788 rtx linsn = get_last_insn ();
2791 /* Mark complex types separately. */
2792 if (GET_CODE (parmreg) == CONCAT)
2794 enum machine_mode submode
2795 = GET_MODE_INNER (GET_MODE (parmreg));
2796 int regnor = REGNO (XEXP (parmreg, 0));
2797 int regnoi = REGNO (XEXP (parmreg, 1));
2798 rtx stackr = adjust_address_nv (data->stack_parm, submode, 0);
2799 rtx stacki = adjust_address_nv (data->stack_parm, submode,
2800 GET_MODE_SIZE (submode));
2802 /* Scan backwards for the set of the real and
2804 for (sinsn = linsn; sinsn != 0;
2805 sinsn = prev_nonnote_insn (sinsn))
2807 set = single_set (sinsn);
2811 if (SET_DEST (set) == regno_reg_rtx [regnoi])
2812 set_unique_reg_note (sinsn, REG_EQUIV, stacki);
2813 else if (SET_DEST (set) == regno_reg_rtx [regnor])
2814 set_unique_reg_note (sinsn, REG_EQUIV, stackr);
2817 else if ((set = single_set (linsn)) != 0
2818 && SET_DEST (set) == parmreg)
2819 set_unique_reg_note (linsn, REG_EQUIV, data->stack_parm);
2822 /* For pointer data type, suggest pointer register. */
2823 if (POINTER_TYPE_P (TREE_TYPE (parm)))
2824 mark_reg_pointer (parmreg,
2825 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
2828 /* A subroutine of assign_parms. Allocate stack space to hold the current
2829 parameter. Get it there. Perform all ABI specified conversions. */
2832 assign_parm_setup_stack (struct assign_parm_data_all *all, tree parm,
2833 struct assign_parm_data_one *data)
2835 /* Value must be stored in the stack slot STACK_PARM during function
2837 bool to_conversion = false;
2839 assign_parm_remove_parallels (data);
2841 if (data->promoted_mode != data->nominal_mode)
2843 /* Conversion is required. */
2844 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
2846 emit_move_insn (tempreg, validize_mem (data->entry_parm));
2848 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2849 to_conversion = true;
2851 data->entry_parm = convert_to_mode (data->nominal_mode, tempreg,
2852 TYPE_UNSIGNED (TREE_TYPE (parm)));
2854 if (data->stack_parm)
2855 /* ??? This may need a big-endian conversion on sparc64. */
2857 = adjust_address (data->stack_parm, data->nominal_mode, 0);
2860 if (data->entry_parm != data->stack_parm)
2864 if (data->stack_parm == 0)
2867 = assign_stack_local (GET_MODE (data->entry_parm),
2868 GET_MODE_SIZE (GET_MODE (data->entry_parm)),
2869 TYPE_ALIGN (data->passed_type));
2870 set_mem_attributes (data->stack_parm, parm, 1);
2873 dest = validize_mem (data->stack_parm);
2874 src = validize_mem (data->entry_parm);
2878 /* Use a block move to handle potentially misaligned entry_parm. */
2880 push_to_sequence2 (all->first_conversion_insn,
2881 all->last_conversion_insn);
2882 to_conversion = true;
2884 emit_block_move (dest, src,
2885 GEN_INT (int_size_in_bytes (data->passed_type)),
2889 emit_move_insn (dest, src);
2894 all->first_conversion_insn = get_insns ();
2895 all->last_conversion_insn = get_last_insn ();
2899 SET_DECL_RTL (parm, data->stack_parm);
2902 /* A subroutine of assign_parms. If the ABI splits complex arguments, then
2903 undo the frobbing that we did in assign_parms_augmented_arg_list. */
2906 assign_parms_unsplit_complex (struct assign_parm_data_all *all, tree fnargs)
2909 tree orig_fnargs = all->orig_fnargs;
2911 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm))
2913 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
2914 && targetm.calls.split_complex_arg (TREE_TYPE (parm)))
2916 rtx tmp, real, imag;
2917 enum machine_mode inner = GET_MODE_INNER (DECL_MODE (parm));
2919 real = DECL_RTL (fnargs);
2920 imag = DECL_RTL (TREE_CHAIN (fnargs));
2921 if (inner != GET_MODE (real))
2923 real = gen_lowpart_SUBREG (inner, real);
2924 imag = gen_lowpart_SUBREG (inner, imag);
2927 if (TREE_ADDRESSABLE (parm))
2930 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (parm));
2932 /* split_complex_arg put the real and imag parts in
2933 pseudos. Move them to memory. */
2934 tmp = assign_stack_local (DECL_MODE (parm), size,
2935 TYPE_ALIGN (TREE_TYPE (parm)));
2936 set_mem_attributes (tmp, parm, 1);
2937 rmem = adjust_address_nv (tmp, inner, 0);
2938 imem = adjust_address_nv (tmp, inner, GET_MODE_SIZE (inner));
2939 push_to_sequence2 (all->first_conversion_insn,
2940 all->last_conversion_insn);
2941 emit_move_insn (rmem, real);
2942 emit_move_insn (imem, imag);
2943 all->first_conversion_insn = get_insns ();
2944 all->last_conversion_insn = get_last_insn ();
2948 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
2949 SET_DECL_RTL (parm, tmp);
2951 real = DECL_INCOMING_RTL (fnargs);
2952 imag = DECL_INCOMING_RTL (TREE_CHAIN (fnargs));
2953 if (inner != GET_MODE (real))
2955 real = gen_lowpart_SUBREG (inner, real);
2956 imag = gen_lowpart_SUBREG (inner, imag);
2958 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
2959 set_decl_incoming_rtl (parm, tmp, false);
2960 fnargs = TREE_CHAIN (fnargs);
2964 SET_DECL_RTL (parm, DECL_RTL (fnargs));
2965 set_decl_incoming_rtl (parm, DECL_INCOMING_RTL (fnargs), false);
2967 /* Set MEM_EXPR to the original decl, i.e. to PARM,
2968 instead of the copy of decl, i.e. FNARGS. */
2969 if (DECL_INCOMING_RTL (parm) && MEM_P (DECL_INCOMING_RTL (parm)))
2970 set_mem_expr (DECL_INCOMING_RTL (parm), parm);
2973 fnargs = TREE_CHAIN (fnargs);
2977 /* Assign RTL expressions to the function's parameters. This may involve
2978 copying them into registers and using those registers as the DECL_RTL. */
2981 assign_parms (tree fndecl)
2983 struct assign_parm_data_all all;
2986 crtl->args.internal_arg_pointer
2987 = targetm.calls.internal_arg_pointer ();
2989 assign_parms_initialize_all (&all);
2990 fnargs = assign_parms_augmented_arg_list (&all);
2992 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
2994 struct assign_parm_data_one data;
2996 /* Extract the type of PARM; adjust it according to ABI. */
2997 assign_parm_find_data_types (&all, parm, &data);
2999 /* Early out for errors and void parameters. */
3000 if (data.passed_mode == VOIDmode)
3002 SET_DECL_RTL (parm, const0_rtx);
3003 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
3007 /* Estimate stack alignment from parameter alignment. */
3008 if (SUPPORTS_STACK_ALIGNMENT)
3010 unsigned int align = FUNCTION_ARG_BOUNDARY (data.promoted_mode,
3012 if (TYPE_ALIGN (data.nominal_type) > align)
3013 align = TYPE_ALIGN (data.passed_type);
3014 if (crtl->stack_alignment_estimated < align)
3016 gcc_assert (!crtl->stack_realign_processed);
3017 crtl->stack_alignment_estimated = align;
3021 if (cfun->stdarg && !TREE_CHAIN (parm))
3022 assign_parms_setup_varargs (&all, &data, false);
3024 /* Find out where the parameter arrives in this function. */
3025 assign_parm_find_entry_rtl (&all, &data);
3027 /* Find out where stack space for this parameter might be. */
3028 if (assign_parm_is_stack_parm (&all, &data))
3030 assign_parm_find_stack_rtl (parm, &data);
3031 assign_parm_adjust_entry_rtl (&data);
3034 /* Record permanently how this parm was passed. */
3035 set_decl_incoming_rtl (parm, data.entry_parm, data.passed_pointer);
3037 /* Update info on where next arg arrives in registers. */
3038 FUNCTION_ARG_ADVANCE (all.args_so_far, data.promoted_mode,
3039 data.passed_type, data.named_arg);
3041 assign_parm_adjust_stack_rtl (&data);
3043 if (assign_parm_setup_block_p (&data))
3044 assign_parm_setup_block (&all, parm, &data);
3045 else if (data.passed_pointer || use_register_for_decl (parm))
3046 assign_parm_setup_reg (&all, parm, &data);
3048 assign_parm_setup_stack (&all, parm, &data);
3051 if (targetm.calls.split_complex_arg && fnargs != all.orig_fnargs)
3052 assign_parms_unsplit_complex (&all, fnargs);
3054 /* Output all parameter conversion instructions (possibly including calls)
3055 now that all parameters have been copied out of hard registers. */
3056 emit_insn (all.first_conversion_insn);
3058 /* Estimate reload stack alignment from scalar return mode. */
3059 if (SUPPORTS_STACK_ALIGNMENT)
3061 if (DECL_RESULT (fndecl))
3063 tree type = TREE_TYPE (DECL_RESULT (fndecl));
3064 enum machine_mode mode = TYPE_MODE (type);
3068 && !AGGREGATE_TYPE_P (type))
3070 unsigned int align = GET_MODE_ALIGNMENT (mode);
3071 if (crtl->stack_alignment_estimated < align)
3073 gcc_assert (!crtl->stack_realign_processed);
3074 crtl->stack_alignment_estimated = align;
3080 /* If we are receiving a struct value address as the first argument, set up
3081 the RTL for the function result. As this might require code to convert
3082 the transmitted address to Pmode, we do this here to ensure that possible
3083 preliminary conversions of the address have been emitted already. */
3084 if (all.function_result_decl)
3086 tree result = DECL_RESULT (current_function_decl);
3087 rtx addr = DECL_RTL (all.function_result_decl);
3090 if (DECL_BY_REFERENCE (result))
3094 addr = convert_memory_address (Pmode, addr);
3095 x = gen_rtx_MEM (DECL_MODE (result), addr);
3096 set_mem_attributes (x, result, 1);
3098 SET_DECL_RTL (result, x);
3101 /* We have aligned all the args, so add space for the pretend args. */
3102 crtl->args.pretend_args_size = all.pretend_args_size;
3103 all.stack_args_size.constant += all.extra_pretend_bytes;
3104 crtl->args.size = all.stack_args_size.constant;
3106 /* Adjust function incoming argument size for alignment and
3109 #ifdef REG_PARM_STACK_SPACE
3110 crtl->args.size = MAX (crtl->args.size,
3111 REG_PARM_STACK_SPACE (fndecl));
3114 crtl->args.size = CEIL_ROUND (crtl->args.size,
3115 PARM_BOUNDARY / BITS_PER_UNIT);
3117 #ifdef ARGS_GROW_DOWNWARD
3118 crtl->args.arg_offset_rtx
3119 = (all.stack_args_size.var == 0 ? GEN_INT (-all.stack_args_size.constant)
3120 : expand_expr (size_diffop (all.stack_args_size.var,
3121 size_int (-all.stack_args_size.constant)),
3122 NULL_RTX, VOIDmode, 0));
3124 crtl->args.arg_offset_rtx = ARGS_SIZE_RTX (all.stack_args_size);
3127 /* See how many bytes, if any, of its args a function should try to pop
3130 crtl->args.pops_args = RETURN_POPS_ARGS (fndecl, TREE_TYPE (fndecl),
3133 /* For stdarg.h function, save info about
3134 regs and stack space used by the named args. */
3136 crtl->args.info = all.args_so_far;
3138 /* Set the rtx used for the function return value. Put this in its
3139 own variable so any optimizers that need this information don't have
3140 to include tree.h. Do this here so it gets done when an inlined
3141 function gets output. */
3144 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
3145 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
3147 /* If scalar return value was computed in a pseudo-reg, or was a named
3148 return value that got dumped to the stack, copy that to the hard
3150 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
3152 tree decl_result = DECL_RESULT (fndecl);
3153 rtx decl_rtl = DECL_RTL (decl_result);
3155 if (REG_P (decl_rtl)
3156 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
3157 : DECL_REGISTER (decl_result))
3161 real_decl_rtl = targetm.calls.function_value (TREE_TYPE (decl_result),
3163 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
3164 /* The delay slot scheduler assumes that crtl->return_rtx
3165 holds the hard register containing the return value, not a
3166 temporary pseudo. */
3167 crtl->return_rtx = real_decl_rtl;
3172 /* A subroutine of gimplify_parameters, invoked via walk_tree.
3173 For all seen types, gimplify their sizes. */
3176 gimplify_parm_type (tree *tp, int *walk_subtrees, void *data)
3183 if (POINTER_TYPE_P (t))
3185 else if (TYPE_SIZE (t) && !TREE_CONSTANT (TYPE_SIZE (t))
3186 && !TYPE_SIZES_GIMPLIFIED (t))
3188 gimplify_type_sizes (t, (gimple_seq *) data);
3196 /* Gimplify the parameter list for current_function_decl. This involves
3197 evaluating SAVE_EXPRs of variable sized parameters and generating code
3198 to implement callee-copies reference parameters. Returns a sequence of
3199 statements to add to the beginning of the function. */
3202 gimplify_parameters (void)
3204 struct assign_parm_data_all all;
3206 gimple_seq stmts = NULL;
3208 assign_parms_initialize_all (&all);
3209 fnargs = assign_parms_augmented_arg_list (&all);
3211 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
3213 struct assign_parm_data_one data;
3215 /* Extract the type of PARM; adjust it according to ABI. */
3216 assign_parm_find_data_types (&all, parm, &data);
3218 /* Early out for errors and void parameters. */
3219 if (data.passed_mode == VOIDmode || DECL_SIZE (parm) == NULL)
3222 /* Update info on where next arg arrives in registers. */
3223 FUNCTION_ARG_ADVANCE (all.args_so_far, data.promoted_mode,
3224 data.passed_type, data.named_arg);
3226 /* ??? Once upon a time variable_size stuffed parameter list
3227 SAVE_EXPRs (amongst others) onto a pending sizes list. This
3228 turned out to be less than manageable in the gimple world.
3229 Now we have to hunt them down ourselves. */
3230 walk_tree_without_duplicates (&data.passed_type,
3231 gimplify_parm_type, &stmts);
3233 if (!TREE_CONSTANT (DECL_SIZE (parm)))
3235 gimplify_one_sizepos (&DECL_SIZE (parm), &stmts);
3236 gimplify_one_sizepos (&DECL_SIZE_UNIT (parm), &stmts);
3239 if (data.passed_pointer)
3241 tree type = TREE_TYPE (data.passed_type);
3242 if (reference_callee_copied (&all.args_so_far, TYPE_MODE (type),
3243 type, data.named_arg))
3247 /* For constant sized objects, this is trivial; for
3248 variable-sized objects, we have to play games. */
3249 if (TREE_CONSTANT (DECL_SIZE (parm)))
3251 local = create_tmp_var (type, get_name (parm));
3252 DECL_IGNORED_P (local) = 0;
3256 tree ptr_type, addr;
3258 ptr_type = build_pointer_type (type);
3259 addr = create_tmp_var (ptr_type, get_name (parm));
3260 DECL_IGNORED_P (addr) = 0;
3261 local = build_fold_indirect_ref (addr);
3263 t = built_in_decls[BUILT_IN_ALLOCA];
3264 t = build_call_expr (t, 1, DECL_SIZE_UNIT (parm));
3265 t = fold_convert (ptr_type, t);
3266 t = build2 (MODIFY_EXPR, TREE_TYPE (addr), addr, t);
3267 gimplify_and_add (t, &stmts);
3270 gimplify_assign (local, parm, &stmts);
3272 SET_DECL_VALUE_EXPR (parm, local);
3273 DECL_HAS_VALUE_EXPR_P (parm) = 1;
3281 /* Compute the size and offset from the start of the stacked arguments for a
3282 parm passed in mode PASSED_MODE and with type TYPE.
3284 INITIAL_OFFSET_PTR points to the current offset into the stacked
3287 The starting offset and size for this parm are returned in
3288 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
3289 nonzero, the offset is that of stack slot, which is returned in
3290 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
3291 padding required from the initial offset ptr to the stack slot.
3293 IN_REGS is nonzero if the argument will be passed in registers. It will
3294 never be set if REG_PARM_STACK_SPACE is not defined.
3296 FNDECL is the function in which the argument was defined.
3298 There are two types of rounding that are done. The first, controlled by
3299 FUNCTION_ARG_BOUNDARY, forces the offset from the start of the argument
3300 list to be aligned to the specific boundary (in bits). This rounding
3301 affects the initial and starting offsets, but not the argument size.
3303 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
3304 optionally rounds the size of the parm to PARM_BOUNDARY. The
3305 initial offset is not affected by this rounding, while the size always
3306 is and the starting offset may be. */
3308 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
3309 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
3310 callers pass in the total size of args so far as
3311 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
3314 locate_and_pad_parm (enum machine_mode passed_mode, tree type, int in_regs,
3315 int partial, tree fndecl ATTRIBUTE_UNUSED,
3316 struct args_size *initial_offset_ptr,
3317 struct locate_and_pad_arg_data *locate)
3320 enum direction where_pad;
3321 unsigned int boundary;
3322 int reg_parm_stack_space = 0;
3323 int part_size_in_regs;
3325 #ifdef REG_PARM_STACK_SPACE
3326 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
3328 /* If we have found a stack parm before we reach the end of the
3329 area reserved for registers, skip that area. */
3332 if (reg_parm_stack_space > 0)
3334 if (initial_offset_ptr->var)
3336 initial_offset_ptr->var
3337 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
3338 ssize_int (reg_parm_stack_space));
3339 initial_offset_ptr->constant = 0;
3341 else if (initial_offset_ptr->constant < reg_parm_stack_space)
3342 initial_offset_ptr->constant = reg_parm_stack_space;
3345 #endif /* REG_PARM_STACK_SPACE */
3347 part_size_in_regs = (reg_parm_stack_space == 0 ? partial : 0);
3350 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
3351 where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
3352 boundary = FUNCTION_ARG_BOUNDARY (passed_mode, type);
3353 locate->where_pad = where_pad;
3355 /* Alignment can't exceed MAX_SUPPORTED_STACK_ALIGNMENT. */
3356 if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
3357 boundary = MAX_SUPPORTED_STACK_ALIGNMENT;
3359 locate->boundary = boundary;
3361 if (SUPPORTS_STACK_ALIGNMENT)
3363 /* stack_alignment_estimated can't change after stack has been
3365 if (crtl->stack_alignment_estimated < boundary)
3367 if (!crtl->stack_realign_processed)
3368 crtl->stack_alignment_estimated = boundary;
3371 /* If stack is realigned and stack alignment value
3372 hasn't been finalized, it is OK not to increase
3373 stack_alignment_estimated. The bigger alignment
3374 requirement is recorded in stack_alignment_needed
3376 gcc_assert (!crtl->stack_realign_finalized
3377 && crtl->stack_realign_needed);
3382 /* Remember if the outgoing parameter requires extra alignment on the
3383 calling function side. */
3384 if (crtl->stack_alignment_needed < boundary)
3385 crtl->stack_alignment_needed = boundary;
3386 if (crtl->max_used_stack_slot_alignment < crtl->stack_alignment_needed)
3387 crtl->max_used_stack_slot_alignment = crtl->stack_alignment_needed;
3388 if (crtl->preferred_stack_boundary < boundary)
3389 crtl->preferred_stack_boundary = boundary;
3391 #ifdef ARGS_GROW_DOWNWARD
3392 locate->slot_offset.constant = -initial_offset_ptr->constant;
3393 if (initial_offset_ptr->var)
3394 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
3395 initial_offset_ptr->var);
3399 if (where_pad != none
3400 && (!host_integerp (sizetree, 1)
3401 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
3402 s2 = round_up (s2, PARM_BOUNDARY / BITS_PER_UNIT);
3403 SUB_PARM_SIZE (locate->slot_offset, s2);
3406 locate->slot_offset.constant += part_size_in_regs;
3409 #ifdef REG_PARM_STACK_SPACE
3410 || REG_PARM_STACK_SPACE (fndecl) > 0
3413 pad_to_arg_alignment (&locate->slot_offset, boundary,
3414 &locate->alignment_pad);
3416 locate->size.constant = (-initial_offset_ptr->constant
3417 - locate->slot_offset.constant);
3418 if (initial_offset_ptr->var)
3419 locate->size.var = size_binop (MINUS_EXPR,
3420 size_binop (MINUS_EXPR,
3422 initial_offset_ptr->var),
3423 locate->slot_offset.var);
3425 /* Pad_below needs the pre-rounded size to know how much to pad
3427 locate->offset = locate->slot_offset;
3428 if (where_pad == downward)
3429 pad_below (&locate->offset, passed_mode, sizetree);
3431 #else /* !ARGS_GROW_DOWNWARD */
3433 #ifdef REG_PARM_STACK_SPACE
3434 || REG_PARM_STACK_SPACE (fndecl) > 0
3437 pad_to_arg_alignment (initial_offset_ptr, boundary,
3438 &locate->alignment_pad);
3439 locate->slot_offset = *initial_offset_ptr;
3441 #ifdef PUSH_ROUNDING
3442 if (passed_mode != BLKmode)
3443 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
3446 /* Pad_below needs the pre-rounded size to know how much to pad below
3447 so this must be done before rounding up. */
3448 locate->offset = locate->slot_offset;
3449 if (where_pad == downward)
3450 pad_below (&locate->offset, passed_mode, sizetree);
3452 if (where_pad != none
3453 && (!host_integerp (sizetree, 1)
3454 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
3455 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3457 ADD_PARM_SIZE (locate->size, sizetree);
3459 locate->size.constant -= part_size_in_regs;
3460 #endif /* ARGS_GROW_DOWNWARD */
3463 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
3464 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
3467 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
3468 struct args_size *alignment_pad)
3470 tree save_var = NULL_TREE;
3471 HOST_WIDE_INT save_constant = 0;
3472 int boundary_in_bytes = boundary / BITS_PER_UNIT;
3473 HOST_WIDE_INT sp_offset = STACK_POINTER_OFFSET;
3475 #ifdef SPARC_STACK_BOUNDARY_HACK
3476 /* ??? The SPARC port may claim a STACK_BOUNDARY higher than
3477 the real alignment of %sp. However, when it does this, the
3478 alignment of %sp+STACK_POINTER_OFFSET is STACK_BOUNDARY. */
3479 if (SPARC_STACK_BOUNDARY_HACK)
3483 if (boundary > PARM_BOUNDARY)
3485 save_var = offset_ptr->var;
3486 save_constant = offset_ptr->constant;
3489 alignment_pad->var = NULL_TREE;
3490 alignment_pad->constant = 0;
3492 if (boundary > BITS_PER_UNIT)
3494 if (offset_ptr->var)
3496 tree sp_offset_tree = ssize_int (sp_offset);
3497 tree offset = size_binop (PLUS_EXPR,
3498 ARGS_SIZE_TREE (*offset_ptr),
3500 #ifdef ARGS_GROW_DOWNWARD
3501 tree rounded = round_down (offset, boundary / BITS_PER_UNIT);
3503 tree rounded = round_up (offset, boundary / BITS_PER_UNIT);
3506 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
3507 /* ARGS_SIZE_TREE includes constant term. */
3508 offset_ptr->constant = 0;
3509 if (boundary > PARM_BOUNDARY)
3510 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
3515 offset_ptr->constant = -sp_offset +
3516 #ifdef ARGS_GROW_DOWNWARD
3517 FLOOR_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
3519 CEIL_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
3521 if (boundary > PARM_BOUNDARY)
3522 alignment_pad->constant = offset_ptr->constant - save_constant;
3528 pad_below (struct args_size *offset_ptr, enum machine_mode passed_mode, tree sizetree)
3530 if (passed_mode != BLKmode)
3532 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
3533 offset_ptr->constant
3534 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
3535 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
3536 - GET_MODE_SIZE (passed_mode));
3540 if (TREE_CODE (sizetree) != INTEGER_CST
3541 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
3543 /* Round the size up to multiple of PARM_BOUNDARY bits. */
3544 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3546 ADD_PARM_SIZE (*offset_ptr, s2);
3547 SUB_PARM_SIZE (*offset_ptr, sizetree);
3553 /* True if register REGNO was alive at a place where `setjmp' was
3554 called and was set more than once or is an argument. Such regs may
3555 be clobbered by `longjmp'. */
3558 regno_clobbered_at_setjmp (bitmap setjmp_crosses, int regno)
3560 /* There appear to be cases where some local vars never reach the
3561 backend but have bogus regnos. */
3562 if (regno >= max_reg_num ())
3565 return ((REG_N_SETS (regno) > 1
3566 || REGNO_REG_SET_P (df_get_live_out (ENTRY_BLOCK_PTR), regno))
3567 && REGNO_REG_SET_P (setjmp_crosses, regno));
3570 /* Walk the tree of blocks describing the binding levels within a
3571 function and warn about variables the might be killed by setjmp or
3572 vfork. This is done after calling flow_analysis before register
3573 allocation since that will clobber the pseudo-regs to hard
3577 setjmp_vars_warning (bitmap setjmp_crosses, tree block)
3581 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
3583 if (TREE_CODE (decl) == VAR_DECL
3584 && DECL_RTL_SET_P (decl)
3585 && REG_P (DECL_RTL (decl))
3586 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
3587 warning (OPT_Wclobbered, "variable %q+D might be clobbered by"
3588 " %<longjmp%> or %<vfork%>", decl);
3591 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = BLOCK_CHAIN (sub))
3592 setjmp_vars_warning (setjmp_crosses, sub);
3595 /* Do the appropriate part of setjmp_vars_warning
3596 but for arguments instead of local variables. */
3599 setjmp_args_warning (bitmap setjmp_crosses)
3602 for (decl = DECL_ARGUMENTS (current_function_decl);
3603 decl; decl = TREE_CHAIN (decl))
3604 if (DECL_RTL (decl) != 0
3605 && REG_P (DECL_RTL (decl))
3606 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
3607 warning (OPT_Wclobbered,
3608 "argument %q+D might be clobbered by %<longjmp%> or %<vfork%>",
3612 /* Generate warning messages for variables live across setjmp. */
3615 generate_setjmp_warnings (void)
3617 bitmap setjmp_crosses = regstat_get_setjmp_crosses ();
3619 if (n_basic_blocks == NUM_FIXED_BLOCKS
3620 || bitmap_empty_p (setjmp_crosses))
3623 setjmp_vars_warning (setjmp_crosses, DECL_INITIAL (current_function_decl));
3624 setjmp_args_warning (setjmp_crosses);
3628 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
3629 and create duplicate blocks. */
3630 /* ??? Need an option to either create block fragments or to create
3631 abstract origin duplicates of a source block. It really depends
3632 on what optimization has been performed. */
3635 reorder_blocks (void)
3637 tree block = DECL_INITIAL (current_function_decl);
3638 VEC(tree,heap) *block_stack;
3640 if (block == NULL_TREE)
3643 block_stack = VEC_alloc (tree, heap, 10);
3645 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
3646 clear_block_marks (block);
3648 /* Prune the old trees away, so that they don't get in the way. */
3649 BLOCK_SUBBLOCKS (block) = NULL_TREE;
3650 BLOCK_CHAIN (block) = NULL_TREE;
3652 /* Recreate the block tree from the note nesting. */
3653 reorder_blocks_1 (get_insns (), block, &block_stack);
3654 BLOCK_SUBBLOCKS (block) = blocks_nreverse (BLOCK_SUBBLOCKS (block));
3656 VEC_free (tree, heap, block_stack);
3659 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
3662 clear_block_marks (tree block)
3666 TREE_ASM_WRITTEN (block) = 0;
3667 clear_block_marks (BLOCK_SUBBLOCKS (block));
3668 block = BLOCK_CHAIN (block);
3673 reorder_blocks_1 (rtx insns, tree current_block, VEC(tree,heap) **p_block_stack)
3677 for (insn = insns; insn; insn = NEXT_INSN (insn))
3681 if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_BEG)
3683 tree block = NOTE_BLOCK (insn);
3686 origin = (BLOCK_FRAGMENT_ORIGIN (block)
3687 ? BLOCK_FRAGMENT_ORIGIN (block)
3690 /* If we have seen this block before, that means it now
3691 spans multiple address regions. Create a new fragment. */
3692 if (TREE_ASM_WRITTEN (block))
3694 tree new_block = copy_node (block);
3696 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
3697 BLOCK_FRAGMENT_CHAIN (new_block)
3698 = BLOCK_FRAGMENT_CHAIN (origin);
3699 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
3701 NOTE_BLOCK (insn) = new_block;
3705 BLOCK_SUBBLOCKS (block) = 0;
3706 TREE_ASM_WRITTEN (block) = 1;
3707 /* When there's only one block for the entire function,
3708 current_block == block and we mustn't do this, it
3709 will cause infinite recursion. */
3710 if (block != current_block)
3712 if (block != origin)
3713 gcc_assert (BLOCK_SUPERCONTEXT (origin) == current_block);
3715 BLOCK_SUPERCONTEXT (block) = current_block;
3716 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
3717 BLOCK_SUBBLOCKS (current_block) = block;
3718 current_block = origin;
3720 VEC_safe_push (tree, heap, *p_block_stack, block);
3722 else if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_END)
3724 NOTE_BLOCK (insn) = VEC_pop (tree, *p_block_stack);
3725 BLOCK_SUBBLOCKS (current_block)
3726 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block));
3727 current_block = BLOCK_SUPERCONTEXT (current_block);
3733 /* Reverse the order of elements in the chain T of blocks,
3734 and return the new head of the chain (old last element). */
3737 blocks_nreverse (tree t)
3739 tree prev = 0, decl, next;
3740 for (decl = t; decl; decl = next)
3742 next = BLOCK_CHAIN (decl);
3743 BLOCK_CHAIN (decl) = prev;
3749 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
3750 non-NULL, list them all into VECTOR, in a depth-first preorder
3751 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
3755 all_blocks (tree block, tree *vector)
3761 TREE_ASM_WRITTEN (block) = 0;
3763 /* Record this block. */
3765 vector[n_blocks] = block;
3769 /* Record the subblocks, and their subblocks... */
3770 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
3771 vector ? vector + n_blocks : 0);
3772 block = BLOCK_CHAIN (block);
3778 /* Return a vector containing all the blocks rooted at BLOCK. The
3779 number of elements in the vector is stored in N_BLOCKS_P. The
3780 vector is dynamically allocated; it is the caller's responsibility
3781 to call `free' on the pointer returned. */
3784 get_block_vector (tree block, int *n_blocks_p)
3788 *n_blocks_p = all_blocks (block, NULL);
3789 block_vector = XNEWVEC (tree, *n_blocks_p);
3790 all_blocks (block, block_vector);
3792 return block_vector;
3795 static GTY(()) int next_block_index = 2;
3797 /* Set BLOCK_NUMBER for all the blocks in FN. */
3800 number_blocks (tree fn)
3806 /* For SDB and XCOFF debugging output, we start numbering the blocks
3807 from 1 within each function, rather than keeping a running
3809 #if defined (SDB_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
3810 if (write_symbols == SDB_DEBUG || write_symbols == XCOFF_DEBUG)
3811 next_block_index = 1;
3814 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
3816 /* The top-level BLOCK isn't numbered at all. */
3817 for (i = 1; i < n_blocks; ++i)
3818 /* We number the blocks from two. */
3819 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
3821 free (block_vector);
3826 /* If VAR is present in a subblock of BLOCK, return the subblock. */
3829 debug_find_var_in_block_tree (tree var, tree block)
3833 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
3837 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
3839 tree ret = debug_find_var_in_block_tree (var, t);
3847 /* Keep track of whether we're in a dummy function context. If we are,
3848 we don't want to invoke the set_current_function hook, because we'll
3849 get into trouble if the hook calls target_reinit () recursively or
3850 when the initial initialization is not yet complete. */
3852 static bool in_dummy_function;
3854 /* Invoke the target hook when setting cfun. Update the optimization options
3855 if the function uses different options than the default. */
3858 invoke_set_current_function_hook (tree fndecl)
3860 if (!in_dummy_function)
3862 tree opts = ((fndecl)
3863 ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (fndecl)
3864 : optimization_default_node);
3867 opts = optimization_default_node;
3869 /* Change optimization options if needed. */
3870 if (optimization_current_node != opts)
3872 optimization_current_node = opts;
3873 cl_optimization_restore (TREE_OPTIMIZATION (opts));
3876 targetm.set_current_function (fndecl);
3880 /* cfun should never be set directly; use this function. */
3883 set_cfun (struct function *new_cfun)
3885 if (cfun != new_cfun)
3888 invoke_set_current_function_hook (new_cfun ? new_cfun->decl : NULL_TREE);
3892 /* Keep track of the cfun stack. */
3894 typedef struct function *function_p;
3896 DEF_VEC_P(function_p);
3897 DEF_VEC_ALLOC_P(function_p,heap);
3899 /* Initialized with NOGC, making this poisonous to the garbage collector. */
3901 static VEC(function_p,heap) *cfun_stack;
3903 /* Push the current cfun onto the stack, and set cfun to new_cfun. */
3906 push_cfun (struct function *new_cfun)
3908 VEC_safe_push (function_p, heap, cfun_stack, cfun);
3909 set_cfun (new_cfun);
3912 /* Pop cfun from the stack. */
3917 struct function *new_cfun = VEC_pop (function_p, cfun_stack);
3918 set_cfun (new_cfun);
3921 /* Return value of funcdef and increase it. */
3923 get_next_funcdef_no (void)
3925 return funcdef_no++;
3928 /* Allocate a function structure for FNDECL and set its contents
3929 to the defaults. Set cfun to the newly-allocated object.
3930 Some of the helper functions invoked during initialization assume
3931 that cfun has already been set. Therefore, assign the new object
3932 directly into cfun and invoke the back end hook explicitly at the
3933 very end, rather than initializing a temporary and calling set_cfun
3936 ABSTRACT_P is true if this is a function that will never be seen by
3937 the middle-end. Such functions are front-end concepts (like C++
3938 function templates) that do not correspond directly to functions
3939 placed in object files. */
3942 allocate_struct_function (tree fndecl, bool abstract_p)
3945 tree fntype = fndecl ? TREE_TYPE (fndecl) : NULL_TREE;
3947 cfun = GGC_CNEW (struct function);
3949 cfun->function_frequency = FUNCTION_FREQUENCY_NORMAL;
3951 init_eh_for_function ();
3953 if (init_machine_status)
3954 cfun->machine = (*init_machine_status) ();
3956 #ifdef OVERRIDE_ABI_FORMAT
3957 OVERRIDE_ABI_FORMAT (fndecl);
3960 if (fndecl != NULL_TREE)
3962 DECL_STRUCT_FUNCTION (fndecl) = cfun;
3963 cfun->decl = fndecl;
3964 current_function_funcdef_no = get_next_funcdef_no ();
3966 result = DECL_RESULT (fndecl);
3967 if (!abstract_p && aggregate_value_p (result, fndecl))
3969 #ifdef PCC_STATIC_STRUCT_RETURN
3970 cfun->returns_pcc_struct = 1;
3972 cfun->returns_struct = 1;
3977 && TYPE_ARG_TYPES (fntype) != 0
3978 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
3979 != void_type_node));
3981 /* Assume all registers in stdarg functions need to be saved. */
3982 cfun->va_list_gpr_size = VA_LIST_MAX_GPR_SIZE;
3983 cfun->va_list_fpr_size = VA_LIST_MAX_FPR_SIZE;
3986 invoke_set_current_function_hook (fndecl);
3989 /* This is like allocate_struct_function, but pushes a new cfun for FNDECL
3990 instead of just setting it. */
3993 push_struct_function (tree fndecl)
3995 VEC_safe_push (function_p, heap, cfun_stack, cfun);
3996 allocate_struct_function (fndecl, false);
3999 /* Reset cfun, and other non-struct-function variables to defaults as
4000 appropriate for emitting rtl at the start of a function. */
4003 prepare_function_start (void)
4005 gcc_assert (!crtl->emit.x_last_insn);
4007 init_varasm_status ();
4009 default_rtl_profile ();
4011 cse_not_expected = ! optimize;
4013 /* Caller save not needed yet. */
4014 caller_save_needed = 0;
4016 /* We haven't done register allocation yet. */
4019 /* Indicate that we have not instantiated virtual registers yet. */
4020 virtuals_instantiated = 0;
4022 /* Indicate that we want CONCATs now. */
4023 generating_concat_p = 1;
4025 /* Indicate we have no need of a frame pointer yet. */
4026 frame_pointer_needed = 0;
4029 /* Initialize the rtl expansion mechanism so that we can do simple things
4030 like generate sequences. This is used to provide a context during global
4031 initialization of some passes. You must call expand_dummy_function_end
4032 to exit this context. */
4035 init_dummy_function_start (void)
4037 gcc_assert (!in_dummy_function);
4038 in_dummy_function = true;
4039 push_struct_function (NULL_TREE);
4040 prepare_function_start ();
4043 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
4044 and initialize static variables for generating RTL for the statements
4048 init_function_start (tree subr)
4050 if (subr && DECL_STRUCT_FUNCTION (subr))
4051 set_cfun (DECL_STRUCT_FUNCTION (subr));
4053 allocate_struct_function (subr, false);
4054 prepare_function_start ();
4056 /* Warn if this value is an aggregate type,
4057 regardless of which calling convention we are using for it. */
4058 if (AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
4059 warning (OPT_Waggregate_return, "function returns an aggregate");
4062 /* Make sure all values used by the optimization passes have sane
4065 init_function_for_compilation (void)
4069 /* No prologue/epilogue insns yet. Make sure that these vectors are
4071 gcc_assert (VEC_length (int, prologue) == 0);
4072 gcc_assert (VEC_length (int, epilogue) == 0);
4073 gcc_assert (VEC_length (int, sibcall_epilogue) == 0);
4077 struct rtl_opt_pass pass_init_function =
4083 init_function_for_compilation, /* execute */
4086 0, /* static_pass_number */
4088 0, /* properties_required */
4089 0, /* properties_provided */
4090 0, /* properties_destroyed */
4091 0, /* todo_flags_start */
4092 0 /* todo_flags_finish */
4098 expand_main_function (void)
4100 #if (defined(INVOKE__main) \
4101 || (!defined(HAS_INIT_SECTION) \
4102 && !defined(INIT_SECTION_ASM_OP) \
4103 && !defined(INIT_ARRAY_SECTION_ASM_OP)))
4104 emit_library_call (init_one_libfunc (NAME__MAIN), LCT_NORMAL, VOIDmode, 0);
4108 /* Expand code to initialize the stack_protect_guard. This is invoked at
4109 the beginning of a function to be protected. */
4111 #ifndef HAVE_stack_protect_set
4112 # define HAVE_stack_protect_set 0
4113 # define gen_stack_protect_set(x,y) (gcc_unreachable (), NULL_RTX)
4117 stack_protect_prologue (void)
4119 tree guard_decl = targetm.stack_protect_guard ();
4122 /* Avoid expand_expr here, because we don't want guard_decl pulled
4123 into registers unless absolutely necessary. And we know that
4124 crtl->stack_protect_guard is a local stack slot, so this skips
4126 x = validize_mem (DECL_RTL (crtl->stack_protect_guard));
4127 y = validize_mem (DECL_RTL (guard_decl));
4129 /* Allow the target to copy from Y to X without leaking Y into a
4131 if (HAVE_stack_protect_set)
4133 rtx insn = gen_stack_protect_set (x, y);
4141 /* Otherwise do a straight move. */
4142 emit_move_insn (x, y);
4145 /* Expand code to verify the stack_protect_guard. This is invoked at
4146 the end of a function to be protected. */
4148 #ifndef HAVE_stack_protect_test
4149 # define HAVE_stack_protect_test 0
4150 # define gen_stack_protect_test(x, y, z) (gcc_unreachable (), NULL_RTX)
4154 stack_protect_epilogue (void)
4156 tree guard_decl = targetm.stack_protect_guard ();
4157 rtx label = gen_label_rtx ();
4160 /* Avoid expand_expr here, because we don't want guard_decl pulled
4161 into registers unless absolutely necessary. And we know that
4162 crtl->stack_protect_guard is a local stack slot, so this skips
4164 x = validize_mem (DECL_RTL (crtl->stack_protect_guard));
4165 y = validize_mem (DECL_RTL (guard_decl));
4167 /* Allow the target to compare Y with X without leaking either into
4169 switch (HAVE_stack_protect_test != 0)
4172 tmp = gen_stack_protect_test (x, y, label);
4181 emit_cmp_and_jump_insns (x, y, EQ, NULL_RTX, ptr_mode, 1, label);
4185 /* The noreturn predictor has been moved to the tree level. The rtl-level
4186 predictors estimate this branch about 20%, which isn't enough to get
4187 things moved out of line. Since this is the only extant case of adding
4188 a noreturn function at the rtl level, it doesn't seem worth doing ought
4189 except adding the prediction by hand. */
4190 tmp = get_last_insn ();
4192 predict_insn_def (tmp, PRED_NORETURN, TAKEN);
4194 expand_expr_stmt (targetm.stack_protect_fail ());
4198 /* Start the RTL for a new function, and set variables used for
4200 SUBR is the FUNCTION_DECL node.
4201 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
4202 the function's parameters, which must be run at any return statement. */
4205 expand_function_start (tree subr)
4207 /* Make sure volatile mem refs aren't considered
4208 valid operands of arithmetic insns. */
4209 init_recog_no_volatile ();
4213 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
4216 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
4218 /* Make the label for return statements to jump to. Do not special
4219 case machines with special return instructions -- they will be
4220 handled later during jump, ifcvt, or epilogue creation. */
4221 return_label = gen_label_rtx ();
4223 /* Initialize rtx used to return the value. */
4224 /* Do this before assign_parms so that we copy the struct value address
4225 before any library calls that assign parms might generate. */
4227 /* Decide whether to return the value in memory or in a register. */
4228 if (aggregate_value_p (DECL_RESULT (subr), subr))
4230 /* Returning something that won't go in a register. */
4231 rtx value_address = 0;
4233 #ifdef PCC_STATIC_STRUCT_RETURN
4234 if (cfun->returns_pcc_struct)
4236 int size = int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr)));
4237 value_address = assemble_static_space (size);
4242 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 2);
4243 /* Expect to be passed the address of a place to store the value.
4244 If it is passed as an argument, assign_parms will take care of
4248 value_address = gen_reg_rtx (Pmode);
4249 emit_move_insn (value_address, sv);
4254 rtx x = value_address;
4255 if (!DECL_BY_REFERENCE (DECL_RESULT (subr)))
4257 x = gen_rtx_MEM (DECL_MODE (DECL_RESULT (subr)), x);
4258 set_mem_attributes (x, DECL_RESULT (subr), 1);
4260 SET_DECL_RTL (DECL_RESULT (subr), x);
4263 else if (DECL_MODE (DECL_RESULT (subr)) == VOIDmode)
4264 /* If return mode is void, this decl rtl should not be used. */
4265 SET_DECL_RTL (DECL_RESULT (subr), NULL_RTX);
4268 /* Compute the return values into a pseudo reg, which we will copy
4269 into the true return register after the cleanups are done. */
4270 tree return_type = TREE_TYPE (DECL_RESULT (subr));
4271 if (TYPE_MODE (return_type) != BLKmode
4272 && targetm.calls.return_in_msb (return_type))
4273 /* expand_function_end will insert the appropriate padding in
4274 this case. Use the return value's natural (unpadded) mode
4275 within the function proper. */
4276 SET_DECL_RTL (DECL_RESULT (subr),
4277 gen_reg_rtx (TYPE_MODE (return_type)));
4280 /* In order to figure out what mode to use for the pseudo, we
4281 figure out what the mode of the eventual return register will
4282 actually be, and use that. */
4283 rtx hard_reg = hard_function_value (return_type, subr, 0, 1);
4285 /* Structures that are returned in registers are not
4286 aggregate_value_p, so we may see a PARALLEL or a REG. */
4287 if (REG_P (hard_reg))
4288 SET_DECL_RTL (DECL_RESULT (subr),
4289 gen_reg_rtx (GET_MODE (hard_reg)));
4292 gcc_assert (GET_CODE (hard_reg) == PARALLEL);
4293 SET_DECL_RTL (DECL_RESULT (subr), gen_group_rtx (hard_reg));
4297 /* Set DECL_REGISTER flag so that expand_function_end will copy the
4298 result to the real return register(s). */
4299 DECL_REGISTER (DECL_RESULT (subr)) = 1;
4302 /* Initialize rtx for parameters and local variables.
4303 In some cases this requires emitting insns. */
4304 assign_parms (subr);
4306 /* If function gets a static chain arg, store it. */
4307 if (cfun->static_chain_decl)
4309 tree parm = cfun->static_chain_decl;
4310 rtx local = gen_reg_rtx (Pmode);
4312 set_decl_incoming_rtl (parm, static_chain_incoming_rtx, false);
4313 SET_DECL_RTL (parm, local);
4314 mark_reg_pointer (local, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
4316 emit_move_insn (local, static_chain_incoming_rtx);
4319 /* If the function receives a non-local goto, then store the
4320 bits we need to restore the frame pointer. */
4321 if (cfun->nonlocal_goto_save_area)
4326 /* ??? We need to do this save early. Unfortunately here is
4327 before the frame variable gets declared. Help out... */
4328 tree var = TREE_OPERAND (cfun->nonlocal_goto_save_area, 0);
4329 if (!DECL_RTL_SET_P (var))
4332 t_save = build4 (ARRAY_REF, ptr_type_node,
4333 cfun->nonlocal_goto_save_area,
4334 integer_zero_node, NULL_TREE, NULL_TREE);
4335 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
4336 r_save = convert_memory_address (Pmode, r_save);
4338 emit_move_insn (r_save, targetm.builtin_setjmp_frame_value ());
4339 update_nonlocal_goto_save_area ();
4342 /* The following was moved from init_function_start.
4343 The move is supposed to make sdb output more accurate. */
4344 /* Indicate the beginning of the function body,
4345 as opposed to parm setup. */
4346 emit_note (NOTE_INSN_FUNCTION_BEG);
4348 gcc_assert (NOTE_P (get_last_insn ()));
4350 parm_birth_insn = get_last_insn ();
4355 PROFILE_HOOK (current_function_funcdef_no);
4359 /* After the display initializations is where the stack checking
4361 if(flag_stack_check)
4362 stack_check_probe_note = emit_note (NOTE_INSN_DELETED);
4364 /* Make sure there is a line number after the function entry setup code. */
4365 force_next_line_note ();
4368 /* Undo the effects of init_dummy_function_start. */
4370 expand_dummy_function_end (void)
4372 gcc_assert (in_dummy_function);
4374 /* End any sequences that failed to be closed due to syntax errors. */
4375 while (in_sequence_p ())
4378 /* Outside function body, can't compute type's actual size
4379 until next function's body starts. */
4381 free_after_parsing (cfun);
4382 free_after_compilation (cfun);
4384 in_dummy_function = false;
4387 /* Call DOIT for each hard register used as a return value from
4388 the current function. */
4391 diddle_return_value (void (*doit) (rtx, void *), void *arg)
4393 rtx outgoing = crtl->return_rtx;
4398 if (REG_P (outgoing))
4399 (*doit) (outgoing, arg);
4400 else if (GET_CODE (outgoing) == PARALLEL)
4404 for (i = 0; i < XVECLEN (outgoing, 0); i++)
4406 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
4408 if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
4415 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
4421 clobber_return_register (void)
4423 diddle_return_value (do_clobber_return_reg, NULL);
4425 /* In case we do use pseudo to return value, clobber it too. */
4426 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
4428 tree decl_result = DECL_RESULT (current_function_decl);
4429 rtx decl_rtl = DECL_RTL (decl_result);
4430 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
4432 do_clobber_return_reg (decl_rtl, NULL);
4438 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
4444 use_return_register (void)
4446 diddle_return_value (do_use_return_reg, NULL);
4449 /* Possibly warn about unused parameters. */
4451 do_warn_unused_parameter (tree fn)
4455 for (decl = DECL_ARGUMENTS (fn);
4456 decl; decl = TREE_CHAIN (decl))
4457 if (!TREE_USED (decl) && TREE_CODE (decl) == PARM_DECL
4458 && DECL_NAME (decl) && !DECL_ARTIFICIAL (decl)
4459 && !TREE_NO_WARNING (decl))
4460 warning (OPT_Wunused_parameter, "unused parameter %q+D", decl);
4463 static GTY(()) rtx initial_trampoline;
4465 /* Generate RTL for the end of the current function. */
4468 expand_function_end (void)
4472 /* If arg_pointer_save_area was referenced only from a nested
4473 function, we will not have initialized it yet. Do that now. */
4474 if (arg_pointer_save_area && ! crtl->arg_pointer_save_area_init)
4475 get_arg_pointer_save_area ();
4477 /* If we are doing stack checking and this function makes calls,
4478 do a stack probe at the start of the function to ensure we have enough
4479 space for another stack frame. */
4480 if (flag_stack_check && ! STACK_CHECK_BUILTIN)
4484 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
4488 probe_stack_range (STACK_CHECK_PROTECT,
4489 GEN_INT (STACK_CHECK_MAX_FRAME_SIZE));
4492 emit_insn_before (seq, stack_check_probe_note);
4497 /* End any sequences that failed to be closed due to syntax errors. */
4498 while (in_sequence_p ())
4501 clear_pending_stack_adjust ();
4502 do_pending_stack_adjust ();
4504 /* Output a linenumber for the end of the function.
4505 SDB depends on this. */
4506 force_next_line_note ();
4507 set_curr_insn_source_location (input_location);
4509 /* Before the return label (if any), clobber the return
4510 registers so that they are not propagated live to the rest of
4511 the function. This can only happen with functions that drop
4512 through; if there had been a return statement, there would
4513 have either been a return rtx, or a jump to the return label.
4515 We delay actual code generation after the current_function_value_rtx
4517 clobber_after = get_last_insn ();
4519 /* Output the label for the actual return from the function. */
4520 emit_label (return_label);
4522 if (USING_SJLJ_EXCEPTIONS)
4524 /* Let except.c know where it should emit the call to unregister
4525 the function context for sjlj exceptions. */
4526 if (flag_exceptions)
4527 sjlj_emit_function_exit_after (get_last_insn ());
4531 /* We want to ensure that instructions that may trap are not
4532 moved into the epilogue by scheduling, because we don't
4533 always emit unwind information for the epilogue. */
4534 if (flag_non_call_exceptions)
4535 emit_insn (gen_blockage ());
4538 /* If this is an implementation of throw, do what's necessary to
4539 communicate between __builtin_eh_return and the epilogue. */
4540 expand_eh_return ();
4542 /* If scalar return value was computed in a pseudo-reg, or was a named
4543 return value that got dumped to the stack, copy that to the hard
4545 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
4547 tree decl_result = DECL_RESULT (current_function_decl);
4548 rtx decl_rtl = DECL_RTL (decl_result);
4550 if (REG_P (decl_rtl)
4551 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
4552 : DECL_REGISTER (decl_result))
4554 rtx real_decl_rtl = crtl->return_rtx;
4556 /* This should be set in assign_parms. */
4557 gcc_assert (REG_FUNCTION_VALUE_P (real_decl_rtl));
4559 /* If this is a BLKmode structure being returned in registers,
4560 then use the mode computed in expand_return. Note that if
4561 decl_rtl is memory, then its mode may have been changed,
4562 but that crtl->return_rtx has not. */
4563 if (GET_MODE (real_decl_rtl) == BLKmode)
4564 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
4566 /* If a non-BLKmode return value should be padded at the least
4567 significant end of the register, shift it left by the appropriate
4568 amount. BLKmode results are handled using the group load/store
4570 if (TYPE_MODE (TREE_TYPE (decl_result)) != BLKmode
4571 && targetm.calls.return_in_msb (TREE_TYPE (decl_result)))
4573 emit_move_insn (gen_rtx_REG (GET_MODE (decl_rtl),
4574 REGNO (real_decl_rtl)),
4576 shift_return_value (GET_MODE (decl_rtl), true, real_decl_rtl);
4578 /* If a named return value dumped decl_return to memory, then
4579 we may need to re-do the PROMOTE_MODE signed/unsigned
4581 else if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
4583 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
4585 if (targetm.calls.promote_function_return (TREE_TYPE (current_function_decl)))
4586 promote_mode (TREE_TYPE (decl_result), GET_MODE (decl_rtl),
4589 convert_move (real_decl_rtl, decl_rtl, unsignedp);
4591 else if (GET_CODE (real_decl_rtl) == PARALLEL)
4593 /* If expand_function_start has created a PARALLEL for decl_rtl,
4594 move the result to the real return registers. Otherwise, do
4595 a group load from decl_rtl for a named return. */
4596 if (GET_CODE (decl_rtl) == PARALLEL)
4597 emit_group_move (real_decl_rtl, decl_rtl);
4599 emit_group_load (real_decl_rtl, decl_rtl,
4600 TREE_TYPE (decl_result),
4601 int_size_in_bytes (TREE_TYPE (decl_result)));
4603 /* In the case of complex integer modes smaller than a word, we'll
4604 need to generate some non-trivial bitfield insertions. Do that
4605 on a pseudo and not the hard register. */
4606 else if (GET_CODE (decl_rtl) == CONCAT
4607 && GET_MODE_CLASS (GET_MODE (decl_rtl)) == MODE_COMPLEX_INT
4608 && GET_MODE_BITSIZE (GET_MODE (decl_rtl)) <= BITS_PER_WORD)
4610 int old_generating_concat_p;
4613 old_generating_concat_p = generating_concat_p;
4614 generating_concat_p = 0;
4615 tmp = gen_reg_rtx (GET_MODE (decl_rtl));
4616 generating_concat_p = old_generating_concat_p;
4618 emit_move_insn (tmp, decl_rtl);
4619 emit_move_insn (real_decl_rtl, tmp);
4622 emit_move_insn (real_decl_rtl, decl_rtl);
4626 /* If returning a structure, arrange to return the address of the value
4627 in a place where debuggers expect to find it.
4629 If returning a structure PCC style,
4630 the caller also depends on this value.
4631 And cfun->returns_pcc_struct is not necessarily set. */
4632 if (cfun->returns_struct
4633 || cfun->returns_pcc_struct)
4635 rtx value_address = DECL_RTL (DECL_RESULT (current_function_decl));
4636 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
4639 if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
4640 type = TREE_TYPE (type);
4642 value_address = XEXP (value_address, 0);
4644 outgoing = targetm.calls.function_value (build_pointer_type (type),
4645 current_function_decl, true);
4647 /* Mark this as a function return value so integrate will delete the
4648 assignment and USE below when inlining this function. */
4649 REG_FUNCTION_VALUE_P (outgoing) = 1;
4651 /* The address may be ptr_mode and OUTGOING may be Pmode. */
4652 value_address = convert_memory_address (GET_MODE (outgoing),
4655 emit_move_insn (outgoing, value_address);
4657 /* Show return register used to hold result (in this case the address
4659 crtl->return_rtx = outgoing;
4662 /* Emit the actual code to clobber return register. */
4667 clobber_return_register ();
4668 expand_naked_return ();
4672 emit_insn_after (seq, clobber_after);
4675 /* Output the label for the naked return from the function. */
4676 emit_label (naked_return_label);
4678 /* @@@ This is a kludge. We want to ensure that instructions that
4679 may trap are not moved into the epilogue by scheduling, because
4680 we don't always emit unwind information for the epilogue. */
4681 if (! USING_SJLJ_EXCEPTIONS && flag_non_call_exceptions)
4682 emit_insn (gen_blockage ());
4684 /* If stack protection is enabled for this function, check the guard. */
4685 if (crtl->stack_protect_guard)
4686 stack_protect_epilogue ();
4688 /* If we had calls to alloca, and this machine needs
4689 an accurate stack pointer to exit the function,
4690 insert some code to save and restore the stack pointer. */
4691 if (! EXIT_IGNORE_STACK
4692 && cfun->calls_alloca)
4696 emit_stack_save (SAVE_FUNCTION, &tem, parm_birth_insn);
4697 emit_stack_restore (SAVE_FUNCTION, tem, NULL_RTX);
4700 /* ??? This should no longer be necessary since stupid is no longer with
4701 us, but there are some parts of the compiler (eg reload_combine, and
4702 sh mach_dep_reorg) that still try and compute their own lifetime info
4703 instead of using the general framework. */
4704 use_return_register ();
4708 get_arg_pointer_save_area (void)
4710 rtx ret = arg_pointer_save_area;
4714 ret = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
4715 arg_pointer_save_area = ret;
4718 if (! crtl->arg_pointer_save_area_init)
4722 /* Save the arg pointer at the beginning of the function. The
4723 generated stack slot may not be a valid memory address, so we
4724 have to check it and fix it if necessary. */
4726 emit_move_insn (validize_mem (ret),
4727 crtl->args.internal_arg_pointer);
4731 push_topmost_sequence ();
4732 emit_insn_after (seq, entry_of_function ());
4733 pop_topmost_sequence ();
4739 /* Extend a vector that records the INSN_UIDs of INSNS
4740 (a list of one or more insns). */
4743 record_insns (rtx insns, VEC(int,heap) **vecp)
4747 for (tmp = insns; tmp != NULL_RTX; tmp = NEXT_INSN (tmp))
4748 VEC_safe_push (int, heap, *vecp, INSN_UID (tmp));
4751 /* Set the locator of the insn chain starting at INSN to LOC. */
4753 set_insn_locators (rtx insn, int loc)
4755 while (insn != NULL_RTX)
4758 INSN_LOCATOR (insn) = loc;
4759 insn = NEXT_INSN (insn);
4763 /* Determine how many INSN_UIDs in VEC are part of INSN. Because we can
4764 be running after reorg, SEQUENCE rtl is possible. */
4767 contains (const_rtx insn, VEC(int,heap) **vec)
4771 if (NONJUMP_INSN_P (insn)
4772 && GET_CODE (PATTERN (insn)) == SEQUENCE)
4775 for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
4776 for (j = VEC_length (int, *vec) - 1; j >= 0; --j)
4777 if (INSN_UID (XVECEXP (PATTERN (insn), 0, i))
4778 == VEC_index (int, *vec, j))
4784 for (j = VEC_length (int, *vec) - 1; j >= 0; --j)
4785 if (INSN_UID (insn) == VEC_index (int, *vec, j))
4792 prologue_epilogue_contains (const_rtx insn)
4794 if (contains (insn, &prologue))
4796 if (contains (insn, &epilogue))
4802 sibcall_epilogue_contains (const_rtx insn)
4804 if (sibcall_epilogue)
4805 return contains (insn, &sibcall_epilogue);
4810 /* Insert gen_return at the end of block BB. This also means updating
4811 block_for_insn appropriately. */
4814 emit_return_into_block (basic_block bb)
4816 emit_jump_insn_after (gen_return (), BB_END (bb));
4818 #endif /* HAVE_return */
4820 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
4821 this into place with notes indicating where the prologue ends and where
4822 the epilogue begins. Update the basic block information when possible. */
4825 thread_prologue_and_epilogue_insns (void)
4829 #if defined (HAVE_sibcall_epilogue) || defined (HAVE_epilogue) || defined (HAVE_return) || defined (HAVE_prologue)
4832 #if defined (HAVE_epilogue) || defined(HAVE_return)
4833 rtx epilogue_end = NULL_RTX;
4837 #ifdef HAVE_prologue
4841 seq = gen_prologue ();
4844 /* Insert an explicit USE for the frame pointer
4845 if the profiling is on and the frame pointer is required. */
4846 if (crtl->profile && frame_pointer_needed)
4847 emit_use (hard_frame_pointer_rtx);
4849 /* Retain a map of the prologue insns. */
4850 record_insns (seq, &prologue);
4851 emit_note (NOTE_INSN_PROLOGUE_END);
4853 #ifndef PROFILE_BEFORE_PROLOGUE
4854 /* Ensure that instructions are not moved into the prologue when
4855 profiling is on. The call to the profiling routine can be
4856 emitted within the live range of a call-clobbered register. */
4858 emit_insn (gen_blockage ());
4863 set_insn_locators (seq, prologue_locator);
4865 /* Can't deal with multiple successors of the entry block
4866 at the moment. Function should always have at least one
4868 gcc_assert (single_succ_p (ENTRY_BLOCK_PTR));
4870 insert_insn_on_edge (seq, single_succ_edge (ENTRY_BLOCK_PTR));
4875 /* If the exit block has no non-fake predecessors, we don't need
4877 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
4878 if ((e->flags & EDGE_FAKE) == 0)
4884 if (optimize && HAVE_return)
4886 /* If we're allowed to generate a simple return instruction,
4887 then by definition we don't need a full epilogue. Examine
4888 the block that falls through to EXIT. If it does not
4889 contain any code, examine its predecessors and try to
4890 emit (conditional) return instructions. */
4895 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
4896 if (e->flags & EDGE_FALLTHRU)
4902 /* Verify that there are no active instructions in the last block. */
4903 label = BB_END (last);
4904 while (label && !LABEL_P (label))
4906 if (active_insn_p (label))
4908 label = PREV_INSN (label);
4911 if (BB_HEAD (last) == label && LABEL_P (label))
4915 for (ei2 = ei_start (last->preds); (e = ei_safe_edge (ei2)); )
4917 basic_block bb = e->src;
4920 if (bb == ENTRY_BLOCK_PTR)
4927 if (!JUMP_P (jump) || JUMP_LABEL (jump) != label)
4933 /* If we have an unconditional jump, we can replace that
4934 with a simple return instruction. */
4935 if (simplejump_p (jump))
4937 emit_return_into_block (bb);
4941 /* If we have a conditional jump, we can try to replace
4942 that with a conditional return instruction. */
4943 else if (condjump_p (jump))
4945 if (! redirect_jump (jump, 0, 0))
4951 /* If this block has only one successor, it both jumps
4952 and falls through to the fallthru block, so we can't
4954 if (single_succ_p (bb))
4966 /* Fix up the CFG for the successful change we just made. */
4967 redirect_edge_succ (e, EXIT_BLOCK_PTR);
4970 /* Emit a return insn for the exit fallthru block. Whether
4971 this is still reachable will be determined later. */
4973 emit_barrier_after (BB_END (last));
4974 emit_return_into_block (last);
4975 epilogue_end = BB_END (last);
4976 single_succ_edge (last)->flags &= ~EDGE_FALLTHRU;
4981 /* Find the edge that falls through to EXIT. Other edges may exist
4982 due to RETURN instructions, but those don't need epilogues.
4983 There really shouldn't be a mixture -- either all should have
4984 been converted or none, however... */
4986 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
4987 if (e->flags & EDGE_FALLTHRU)
4992 #ifdef HAVE_epilogue
4996 epilogue_end = emit_note (NOTE_INSN_EPILOGUE_BEG);
4997 seq = gen_epilogue ();
4998 emit_jump_insn (seq);
5000 /* Retain a map of the epilogue insns. */
5001 record_insns (seq, &epilogue);
5002 set_insn_locators (seq, epilogue_locator);
5007 insert_insn_on_edge (seq, e);
5015 if (! next_active_insn (BB_END (e->src)))
5017 /* We have a fall-through edge to the exit block, the source is not
5018 at the end of the function, and there will be an assembler epilogue
5019 at the end of the function.
5020 We can't use force_nonfallthru here, because that would try to
5021 use return. Inserting a jump 'by hand' is extremely messy, so
5022 we take advantage of cfg_layout_finalize using
5023 fixup_fallthru_exit_predecessor. */
5024 cfg_layout_initialize (0);
5025 FOR_EACH_BB (cur_bb)
5026 if (cur_bb->index >= NUM_FIXED_BLOCKS
5027 && cur_bb->next_bb->index >= NUM_FIXED_BLOCKS)
5028 cur_bb->aux = cur_bb->next_bb;
5029 cfg_layout_finalize ();
5035 commit_edge_insertions ();
5037 /* The epilogue insns we inserted may cause the exit edge to no longer
5039 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5041 if (((e->flags & EDGE_FALLTHRU) != 0)
5042 && returnjump_p (BB_END (e->src)))
5043 e->flags &= ~EDGE_FALLTHRU;
5047 #ifdef HAVE_sibcall_epilogue
5048 /* Emit sibling epilogues before any sibling call sites. */
5049 for (ei = ei_start (EXIT_BLOCK_PTR->preds); (e = ei_safe_edge (ei)); )
5051 basic_block bb = e->src;
5052 rtx insn = BB_END (bb);
5055 || ! SIBLING_CALL_P (insn))
5062 emit_insn (gen_sibcall_epilogue ());
5066 /* Retain a map of the epilogue insns. Used in life analysis to
5067 avoid getting rid of sibcall epilogue insns. Do this before we
5068 actually emit the sequence. */
5069 record_insns (seq, &sibcall_epilogue);
5070 set_insn_locators (seq, epilogue_locator);
5072 emit_insn_before (seq, insn);
5077 #ifdef HAVE_epilogue
5082 /* Similarly, move any line notes that appear after the epilogue.
5083 There is no need, however, to be quite so anal about the existence
5084 of such a note. Also possibly move
5085 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
5087 for (insn = epilogue_end; insn; insn = next)
5089 next = NEXT_INSN (insn);
5091 && (NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG))
5092 reorder_insns (insn, insn, PREV_INSN (epilogue_end));
5097 /* Threading the prologue and epilogue changes the artificial refs
5098 in the entry and exit blocks. */
5099 epilogue_completed = 1;
5100 df_update_entry_exit_and_calls ();
5103 /* Reposition the prologue-end and epilogue-begin notes after instruction
5104 scheduling and delayed branch scheduling. */
5107 reposition_prologue_and_epilogue_notes (void)
5109 #if defined (HAVE_prologue) || defined (HAVE_epilogue)
5110 rtx insn, last, note;
5113 if ((len = VEC_length (int, prologue)) > 0)
5117 /* Scan from the beginning until we reach the last prologue insn.
5118 We apparently can't depend on basic_block_{head,end} after
5120 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
5124 if (NOTE_KIND (insn) == NOTE_INSN_PROLOGUE_END)
5127 else if (contains (insn, &prologue))
5137 /* Find the prologue-end note if we haven't already, and
5138 move it to just after the last prologue insn. */
5141 for (note = last; (note = NEXT_INSN (note));)
5143 && NOTE_KIND (note) == NOTE_INSN_PROLOGUE_END)
5147 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
5149 last = NEXT_INSN (last);
5150 reorder_insns (note, note, last);
5154 if ((len = VEC_length (int, epilogue)) > 0)
5158 /* Scan from the end until we reach the first epilogue insn.
5159 We apparently can't depend on basic_block_{head,end} after
5161 for (insn = get_last_insn (); insn; insn = PREV_INSN (insn))
5165 if (NOTE_KIND (insn) == NOTE_INSN_EPILOGUE_BEG)
5168 else if (contains (insn, &epilogue))
5178 /* Find the epilogue-begin note if we haven't already, and
5179 move it to just before the first epilogue insn. */
5182 for (note = insn; (note = PREV_INSN (note));)
5184 && NOTE_KIND (note) == NOTE_INSN_EPILOGUE_BEG)
5188 if (PREV_INSN (last) != note)
5189 reorder_insns (note, note, PREV_INSN (last));
5192 #endif /* HAVE_prologue or HAVE_epilogue */
5195 /* Returns the name of the current function. */
5197 current_function_name (void)
5199 return lang_hooks.decl_printable_name (cfun->decl, 2);
5202 /* Returns the raw (mangled) name of the current function. */
5204 current_function_assembler_name (void)
5206 return IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (cfun->decl));
5211 rest_of_handle_check_leaf_regs (void)
5213 #ifdef LEAF_REGISTERS
5214 current_function_uses_only_leaf_regs
5215 = optimize > 0 && only_leaf_regs_used () && leaf_function_p ();
5220 /* Insert a TYPE into the used types hash table of CFUN. */
5222 used_types_insert_helper (tree type, struct function *func)
5224 if (type != NULL && func != NULL)
5228 if (func->used_types_hash == NULL)
5229 func->used_types_hash = htab_create_ggc (37, htab_hash_pointer,
5230 htab_eq_pointer, NULL);
5231 slot = htab_find_slot (func->used_types_hash, type, INSERT);
5237 /* Given a type, insert it into the used hash table in cfun. */
5239 used_types_insert (tree t)
5241 while (POINTER_TYPE_P (t) || TREE_CODE (t) == ARRAY_TYPE)
5243 t = TYPE_MAIN_VARIANT (t);
5244 if (debug_info_level > DINFO_LEVEL_NONE)
5245 used_types_insert_helper (t, cfun);
5248 struct rtl_opt_pass pass_leaf_regs =
5254 rest_of_handle_check_leaf_regs, /* execute */
5257 0, /* static_pass_number */
5259 0, /* properties_required */
5260 0, /* properties_provided */
5261 0, /* properties_destroyed */
5262 0, /* todo_flags_start */
5263 0 /* todo_flags_finish */
5268 rest_of_handle_thread_prologue_and_epilogue (void)
5271 cleanup_cfg (CLEANUP_EXPENSIVE);
5272 /* On some machines, the prologue and epilogue code, or parts thereof,
5273 can be represented as RTL. Doing so lets us schedule insns between
5274 it and the rest of the code and also allows delayed branch
5275 scheduling to operate in the epilogue. */
5277 thread_prologue_and_epilogue_insns ();
5281 struct rtl_opt_pass pass_thread_prologue_and_epilogue =
5285 "pro_and_epilogue", /* name */
5287 rest_of_handle_thread_prologue_and_epilogue, /* execute */
5290 0, /* static_pass_number */
5291 TV_THREAD_PROLOGUE_AND_EPILOGUE, /* tv_id */
5292 0, /* properties_required */
5293 0, /* properties_provided */
5294 0, /* properties_destroyed */
5295 TODO_verify_flow, /* todo_flags_start */
5298 TODO_df_finish | TODO_verify_rtl_sharing |
5299 TODO_ggc_collect /* todo_flags_finish */
5304 /* This mini-pass fixes fall-out from SSA in asm statements that have
5305 in-out constraints. Say you start with
5308 asm ("": "+mr" (inout));
5311 which is transformed very early to use explicit output and match operands:
5314 asm ("": "=mr" (inout) : "0" (inout));
5317 Or, after SSA and copyprop,
5319 asm ("": "=mr" (inout_2) : "0" (inout_1));
5322 Clearly inout_2 and inout_1 can't be coalesced easily anymore, as
5323 they represent two separate values, so they will get different pseudo
5324 registers during expansion. Then, since the two operands need to match
5325 per the constraints, but use different pseudo registers, reload can
5326 only register a reload for these operands. But reloads can only be
5327 satisfied by hardregs, not by memory, so we need a register for this
5328 reload, just because we are presented with non-matching operands.
5329 So, even though we allow memory for this operand, no memory can be
5330 used for it, just because the two operands don't match. This can
5331 cause reload failures on register-starved targets.
5333 So it's a symptom of reload not being able to use memory for reloads
5334 or, alternatively it's also a symptom of both operands not coming into
5335 reload as matching (in which case the pseudo could go to memory just
5336 fine, as the alternative allows it, and no reload would be necessary).
5337 We fix the latter problem here, by transforming
5339 asm ("": "=mr" (inout_2) : "0" (inout_1));
5344 asm ("": "=mr" (inout_2) : "0" (inout_2)); */
5347 match_asm_constraints_1 (rtx insn, rtx *p_sets, int noutputs)
5350 bool changed = false;
5351 rtx op = SET_SRC (p_sets[0]);
5352 int ninputs = ASM_OPERANDS_INPUT_LENGTH (op);
5353 rtvec inputs = ASM_OPERANDS_INPUT_VEC (op);
5354 bool *output_matched = XALLOCAVEC (bool, noutputs);
5356 memset (output_matched, 0, noutputs * sizeof (bool));
5357 for (i = 0; i < ninputs; i++)
5359 rtx input, output, insns;
5360 const char *constraint = ASM_OPERANDS_INPUT_CONSTRAINT (op, i);
5364 match = strtoul (constraint, &end, 10);
5365 if (end == constraint)
5368 gcc_assert (match < noutputs);
5369 output = SET_DEST (p_sets[match]);
5370 input = RTVEC_ELT (inputs, i);
5371 /* Only do the transformation for pseudos. */
5372 if (! REG_P (output)
5373 || rtx_equal_p (output, input)
5374 || (GET_MODE (input) != VOIDmode
5375 && GET_MODE (input) != GET_MODE (output)))
5378 /* We can't do anything if the output is also used as input,
5379 as we're going to overwrite it. */
5380 for (j = 0; j < ninputs; j++)
5381 if (reg_overlap_mentioned_p (output, RTVEC_ELT (inputs, j)))
5386 /* Avoid changing the same input several times. For
5387 asm ("" : "=mr" (out1), "=mr" (out2) : "0" (in), "1" (in));
5388 only change in once (to out1), rather than changing it
5389 first to out1 and afterwards to out2. */
5392 for (j = 0; j < noutputs; j++)
5393 if (output_matched[j] && input == SET_DEST (p_sets[j]))
5398 output_matched[match] = true;
5401 emit_move_insn (output, input);
5402 insns = get_insns ();
5404 emit_insn_before (insns, insn);
5406 /* Now replace all mentions of the input with output. We can't
5407 just replace the occurrence in inputs[i], as the register might
5408 also be used in some other input (or even in an address of an
5409 output), which would mean possibly increasing the number of
5410 inputs by one (namely 'output' in addition), which might pose
5411 a too complicated problem for reload to solve. E.g. this situation:
5413 asm ("" : "=r" (output), "=m" (input) : "0" (input))
5415 Here 'input' is used in two occurrences as input (once for the
5416 input operand, once for the address in the second output operand).
5417 If we would replace only the occurrence of the input operand (to
5418 make the matching) we would be left with this:
5421 asm ("" : "=r" (output), "=m" (input) : "0" (output))
5423 Now we suddenly have two different input values (containing the same
5424 value, but different pseudos) where we formerly had only one.
5425 With more complicated asms this might lead to reload failures
5426 which wouldn't have happen without this pass. So, iterate over
5427 all operands and replace all occurrences of the register used. */
5428 for (j = 0; j < noutputs; j++)
5429 if (!rtx_equal_p (SET_DEST (p_sets[j]), input)
5430 && reg_overlap_mentioned_p (input, SET_DEST (p_sets[j])))
5431 SET_DEST (p_sets[j]) = replace_rtx (SET_DEST (p_sets[j]),
5433 for (j = 0; j < ninputs; j++)
5434 if (reg_overlap_mentioned_p (input, RTVEC_ELT (inputs, j)))
5435 RTVEC_ELT (inputs, j) = replace_rtx (RTVEC_ELT (inputs, j),
5442 df_insn_rescan (insn);
5446 rest_of_match_asm_constraints (void)
5449 rtx insn, pat, *p_sets;
5452 if (!crtl->has_asm_statement)
5455 df_set_flags (DF_DEFER_INSN_RESCAN);
5458 FOR_BB_INSNS (bb, insn)
5463 pat = PATTERN (insn);
5464 if (GET_CODE (pat) == PARALLEL)
5465 p_sets = &XVECEXP (pat, 0, 0), noutputs = XVECLEN (pat, 0);
5466 else if (GET_CODE (pat) == SET)
5467 p_sets = &PATTERN (insn), noutputs = 1;
5471 if (GET_CODE (*p_sets) == SET
5472 && GET_CODE (SET_SRC (*p_sets)) == ASM_OPERANDS)
5473 match_asm_constraints_1 (insn, p_sets, noutputs);
5477 return TODO_df_finish;
5480 struct rtl_opt_pass pass_match_asm_constraints =
5484 "asmcons", /* name */
5486 rest_of_match_asm_constraints, /* execute */
5489 0, /* static_pass_number */
5491 0, /* properties_required */
5492 0, /* properties_provided */
5493 0, /* properties_destroyed */
5494 0, /* todo_flags_start */
5495 TODO_dump_func /* todo_flags_finish */
5500 #include "gt-function.h"