1 /* Expands front end tree to back end RTL for GCC.
2 Copyright (C) 1987, 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* This file handles the generation of rtl code from tree structure
23 at the level of the function as a whole.
24 It creates the rtl expressions for parameters and auto variables
25 and has full responsibility for allocating stack slots.
27 `expand_function_start' is called at the beginning of a function,
28 before the function body is parsed, and `expand_function_end' is
29 called after parsing the body.
31 Call `assign_stack_local' to allocate a stack slot for a local variable.
32 This is usually done during the RTL generation for the function body,
33 but it can also be done in the reload pass when a pseudo-register does
34 not get a hard register. */
38 #include "coretypes.h"
49 #include "hard-reg-set.h"
50 #include "insn-config.h"
53 #include "basic-block.h"
58 #include "integrate.h"
59 #include "langhooks.h"
61 #include "cfglayout.h"
63 #include "tree-pass.h"
69 /* So we can assign to cfun in this file. */
72 #ifndef STACK_ALIGNMENT_NEEDED
73 #define STACK_ALIGNMENT_NEEDED 1
76 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
78 /* Some systems use __main in a way incompatible with its use in gcc, in these
79 cases use the macros NAME__MAIN to give a quoted symbol and SYMBOL__MAIN to
80 give the same symbol without quotes for an alternative entry point. You
81 must define both, or neither. */
83 #define NAME__MAIN "__main"
86 /* Round a value to the lowest integer less than it that is a multiple of
87 the required alignment. Avoid using division in case the value is
88 negative. Assume the alignment is a power of two. */
89 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
91 /* Similar, but round to the next highest integer that meets the
93 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
95 /* Nonzero if function being compiled doesn't contain any calls
96 (ignoring the prologue and epilogue). This is set prior to
97 local register allocation and is valid for the remaining
99 int current_function_is_leaf;
101 /* Nonzero if function being compiled doesn't modify the stack pointer
102 (ignoring the prologue and epilogue). This is only valid after
103 pass_stack_ptr_mod has run. */
104 int current_function_sp_is_unchanging;
106 /* Nonzero if the function being compiled is a leaf function which only
107 uses leaf registers. This is valid after reload (specifically after
108 sched2) and is useful only if the port defines LEAF_REGISTERS. */
109 int current_function_uses_only_leaf_regs;
111 /* Nonzero once virtual register instantiation has been done.
112 assign_stack_local uses frame_pointer_rtx when this is nonzero.
113 calls.c:emit_library_call_value_1 uses it to set up
114 post-instantiation libcalls. */
115 int virtuals_instantiated;
117 /* Assign unique numbers to labels generated for profiling, debugging, etc. */
118 static GTY(()) int funcdef_no;
120 /* These variables hold pointers to functions to create and destroy
121 target specific, per-function data structures. */
122 struct machine_function * (*init_machine_status) (void);
124 /* The currently compiled function. */
125 struct function *cfun = 0;
127 /* These arrays record the INSN_UIDs of the prologue and epilogue insns. */
128 static VEC(int,heap) *prologue;
129 static VEC(int,heap) *epilogue;
131 /* Array of INSN_UIDs to hold the INSN_UIDs for each sibcall epilogue
133 static VEC(int,heap) *sibcall_epilogue;
135 /* In order to evaluate some expressions, such as function calls returning
136 structures in memory, we need to temporarily allocate stack locations.
137 We record each allocated temporary in the following structure.
139 Associated with each temporary slot is a nesting level. When we pop up
140 one level, all temporaries associated with the previous level are freed.
141 Normally, all temporaries are freed after the execution of the statement
142 in which they were created. However, if we are inside a ({...}) grouping,
143 the result may be in a temporary and hence must be preserved. If the
144 result could be in a temporary, we preserve it if we can determine which
145 one it is in. If we cannot determine which temporary may contain the
146 result, all temporaries are preserved. A temporary is preserved by
147 pretending it was allocated at the previous nesting level.
149 Automatic variables are also assigned temporary slots, at the nesting
150 level where they are defined. They are marked a "kept" so that
151 free_temp_slots will not free them. */
153 struct temp_slot GTY(())
155 /* Points to next temporary slot. */
156 struct temp_slot *next;
157 /* Points to previous temporary slot. */
158 struct temp_slot *prev;
160 /* The rtx to used to reference the slot. */
162 /* The rtx used to represent the address if not the address of the
163 slot above. May be an EXPR_LIST if multiple addresses exist. */
165 /* The alignment (in bits) of the slot. */
167 /* The size, in units, of the slot. */
169 /* The type of the object in the slot, or zero if it doesn't correspond
170 to a type. We use this to determine whether a slot can be reused.
171 It can be reused if objects of the type of the new slot will always
172 conflict with objects of the type of the old slot. */
174 /* Nonzero if this temporary is currently in use. */
176 /* Nonzero if this temporary has its address taken. */
178 /* Nesting level at which this slot is being used. */
180 /* Nonzero if this should survive a call to free_temp_slots. */
182 /* The offset of the slot from the frame_pointer, including extra space
183 for alignment. This info is for combine_temp_slots. */
184 HOST_WIDE_INT base_offset;
185 /* The size of the slot, including extra space for alignment. This
186 info is for combine_temp_slots. */
187 HOST_WIDE_INT full_size;
190 /* Forward declarations. */
192 static struct temp_slot *find_temp_slot_from_address (rtx);
193 static void pad_to_arg_alignment (struct args_size *, int, struct args_size *);
194 static void pad_below (struct args_size *, enum machine_mode, tree);
195 static void reorder_blocks_1 (rtx, tree, VEC(tree,heap) **);
196 static int all_blocks (tree, tree *);
197 static tree *get_block_vector (tree, int *);
198 extern tree debug_find_var_in_block_tree (tree, tree);
199 /* We always define `record_insns' even if it's not used so that we
200 can always export `prologue_epilogue_contains'. */
201 static void record_insns (rtx, VEC(int,heap) **) ATTRIBUTE_UNUSED;
202 static int contains (const_rtx, VEC(int,heap) **);
204 static void emit_return_into_block (basic_block);
206 static void prepare_function_start (void);
207 static void do_clobber_return_reg (rtx, void *);
208 static void do_use_return_reg (rtx, void *);
209 static void set_insn_locators (rtx, int) ATTRIBUTE_UNUSED;
211 /* Pointer to chain of `struct function' for containing functions. */
212 struct function *outer_function_chain;
214 /* Given a function decl for a containing function,
215 return the `struct function' for it. */
218 find_function_data (tree decl)
222 for (p = outer_function_chain; p; p = p->outer)
229 /* Save the current context for compilation of a nested function.
230 This is called from language-specific code. */
233 push_function_context (void)
236 allocate_struct_function (NULL, false);
238 cfun->outer = outer_function_chain;
239 outer_function_chain = cfun;
243 /* Restore the last saved context, at the end of a nested function.
244 This function is called from language-specific code. */
247 pop_function_context (void)
249 struct function *p = outer_function_chain;
252 outer_function_chain = p->outer;
253 current_function_decl = p->decl;
255 /* Reset variables that have known state during rtx generation. */
256 virtuals_instantiated = 0;
257 generating_concat_p = 1;
260 /* Clear out all parts of the state in F that can safely be discarded
261 after the function has been parsed, but not compiled, to let
262 garbage collection reclaim the memory. */
265 free_after_parsing (struct function *f)
270 /* Clear out all parts of the state in F that can safely be discarded
271 after the function has been compiled, to let garbage collection
272 reclaim the memory. */
275 free_after_compilation (struct function *f)
277 VEC_free (int, heap, prologue);
278 VEC_free (int, heap, epilogue);
279 VEC_free (int, heap, sibcall_epilogue);
280 if (crtl->emit.regno_pointer_align)
281 free (crtl->emit.regno_pointer_align);
283 memset (crtl, 0, sizeof (struct rtl_data));
288 regno_reg_rtx = NULL;
291 /* Return size needed for stack frame based on slots so far allocated.
292 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
293 the caller may have to do that. */
296 get_frame_size (void)
298 if (FRAME_GROWS_DOWNWARD)
299 return -frame_offset;
304 /* Issue an error message and return TRUE if frame OFFSET overflows in
305 the signed target pointer arithmetics for function FUNC. Otherwise
309 frame_offset_overflow (HOST_WIDE_INT offset, tree func)
311 unsigned HOST_WIDE_INT size = FRAME_GROWS_DOWNWARD ? -offset : offset;
313 if (size > ((unsigned HOST_WIDE_INT) 1 << (GET_MODE_BITSIZE (Pmode) - 1))
314 /* Leave room for the fixed part of the frame. */
315 - 64 * UNITS_PER_WORD)
317 error ("%Jtotal size of local objects too large", func);
324 /* Return stack slot alignment in bits for TYPE and MODE. */
327 get_stack_local_alignment (tree type, enum machine_mode mode)
329 unsigned int alignment;
332 alignment = BIGGEST_ALIGNMENT;
334 alignment = GET_MODE_ALIGNMENT (mode);
336 /* Allow the frond-end to (possibly) increase the alignment of this
339 type = lang_hooks.types.type_for_mode (mode, 0);
341 return STACK_SLOT_ALIGNMENT (type, mode, alignment);
344 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
345 with machine mode MODE.
347 ALIGN controls the amount of alignment for the address of the slot:
348 0 means according to MODE,
349 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
350 -2 means use BITS_PER_UNIT,
351 positive specifies alignment boundary in bits.
353 If REDUCE_ALIGNMENT_OK is true, it is OK to reduce alignment.
355 We do not round to stack_boundary here. */
358 assign_stack_local_1 (enum machine_mode mode, HOST_WIDE_INT size,
360 bool reduce_alignment_ok ATTRIBUTE_UNUSED)
363 int bigend_correction = 0;
364 unsigned int alignment, alignment_in_bits;
365 int frame_off, frame_alignment, frame_phase;
369 alignment = get_stack_local_alignment (NULL, mode);
370 alignment /= BITS_PER_UNIT;
372 else if (align == -1)
374 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
375 size = CEIL_ROUND (size, alignment);
377 else if (align == -2)
378 alignment = 1; /* BITS_PER_UNIT / BITS_PER_UNIT */
380 alignment = align / BITS_PER_UNIT;
382 alignment_in_bits = alignment * BITS_PER_UNIT;
384 if (FRAME_GROWS_DOWNWARD)
385 frame_offset -= size;
387 /* Ignore alignment if it exceeds MAX_SUPPORTED_STACK_ALIGNMENT. */
388 if (alignment_in_bits > MAX_SUPPORTED_STACK_ALIGNMENT)
390 alignment_in_bits = MAX_SUPPORTED_STACK_ALIGNMENT;
391 alignment = alignment_in_bits / BITS_PER_UNIT;
394 if (SUPPORTS_STACK_ALIGNMENT)
396 if (crtl->stack_alignment_estimated < alignment_in_bits)
398 if (!crtl->stack_realign_processed)
399 crtl->stack_alignment_estimated = alignment_in_bits;
402 /* If stack is realigned and stack alignment value
403 hasn't been finalized, it is OK not to increase
404 stack_alignment_estimated. The bigger alignment
405 requirement is recorded in stack_alignment_needed
407 gcc_assert (!crtl->stack_realign_finalized);
408 if (!crtl->stack_realign_needed)
410 /* It is OK to reduce the alignment as long as the
411 requested size is 0 or the estimated stack
412 alignment >= mode alignment. */
413 gcc_assert (reduce_alignment_ok
415 || (crtl->stack_alignment_estimated
416 >= GET_MODE_ALIGNMENT (mode)));
417 alignment_in_bits = crtl->stack_alignment_estimated;
418 alignment = alignment_in_bits / BITS_PER_UNIT;
424 if (crtl->stack_alignment_needed < alignment_in_bits)
425 crtl->stack_alignment_needed = alignment_in_bits;
426 if (crtl->max_used_stack_slot_alignment < crtl->stack_alignment_needed)
427 crtl->max_used_stack_slot_alignment = crtl->stack_alignment_needed;
429 /* Calculate how many bytes the start of local variables is off from
431 frame_alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
432 frame_off = STARTING_FRAME_OFFSET % frame_alignment;
433 frame_phase = frame_off ? frame_alignment - frame_off : 0;
435 /* Round the frame offset to the specified alignment. The default is
436 to always honor requests to align the stack but a port may choose to
437 do its own stack alignment by defining STACK_ALIGNMENT_NEEDED. */
438 if (STACK_ALIGNMENT_NEEDED
442 /* We must be careful here, since FRAME_OFFSET might be negative and
443 division with a negative dividend isn't as well defined as we might
444 like. So we instead assume that ALIGNMENT is a power of two and
445 use logical operations which are unambiguous. */
446 if (FRAME_GROWS_DOWNWARD)
448 = (FLOOR_ROUND (frame_offset - frame_phase,
449 (unsigned HOST_WIDE_INT) alignment)
453 = (CEIL_ROUND (frame_offset - frame_phase,
454 (unsigned HOST_WIDE_INT) alignment)
458 /* On a big-endian machine, if we are allocating more space than we will use,
459 use the least significant bytes of those that are allocated. */
460 if (BYTES_BIG_ENDIAN && mode != BLKmode && GET_MODE_SIZE (mode) < size)
461 bigend_correction = size - GET_MODE_SIZE (mode);
463 /* If we have already instantiated virtual registers, return the actual
464 address relative to the frame pointer. */
465 if (virtuals_instantiated)
466 addr = plus_constant (frame_pointer_rtx,
468 (frame_offset + bigend_correction
469 + STARTING_FRAME_OFFSET, Pmode));
471 addr = plus_constant (virtual_stack_vars_rtx,
473 (frame_offset + bigend_correction,
476 if (!FRAME_GROWS_DOWNWARD)
477 frame_offset += size;
479 x = gen_rtx_MEM (mode, addr);
480 set_mem_align (x, alignment_in_bits);
481 MEM_NOTRAP_P (x) = 1;
484 = gen_rtx_EXPR_LIST (VOIDmode, x, stack_slot_list);
486 if (frame_offset_overflow (frame_offset, current_function_decl))
492 /* Wrap up assign_stack_local_1 with last parameter as false. */
495 assign_stack_local (enum machine_mode mode, HOST_WIDE_INT size, int align)
497 return assign_stack_local_1 (mode, size, align, false);
500 /* Removes temporary slot TEMP from LIST. */
503 cut_slot_from_list (struct temp_slot *temp, struct temp_slot **list)
506 temp->next->prev = temp->prev;
508 temp->prev->next = temp->next;
512 temp->prev = temp->next = NULL;
515 /* Inserts temporary slot TEMP to LIST. */
518 insert_slot_to_list (struct temp_slot *temp, struct temp_slot **list)
522 (*list)->prev = temp;
527 /* Returns the list of used temp slots at LEVEL. */
529 static struct temp_slot **
530 temp_slots_at_level (int level)
532 if (level >= (int) VEC_length (temp_slot_p, used_temp_slots))
533 VEC_safe_grow_cleared (temp_slot_p, gc, used_temp_slots, level + 1);
535 return &(VEC_address (temp_slot_p, used_temp_slots)[level]);
538 /* Returns the maximal temporary slot level. */
541 max_slot_level (void)
543 if (!used_temp_slots)
546 return VEC_length (temp_slot_p, used_temp_slots) - 1;
549 /* Moves temporary slot TEMP to LEVEL. */
552 move_slot_to_level (struct temp_slot *temp, int level)
554 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
555 insert_slot_to_list (temp, temp_slots_at_level (level));
559 /* Make temporary slot TEMP available. */
562 make_slot_available (struct temp_slot *temp)
564 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
565 insert_slot_to_list (temp, &avail_temp_slots);
570 /* Allocate a temporary stack slot and record it for possible later
573 MODE is the machine mode to be given to the returned rtx.
575 SIZE is the size in units of the space required. We do no rounding here
576 since assign_stack_local will do any required rounding.
578 KEEP is 1 if this slot is to be retained after a call to
579 free_temp_slots. Automatic variables for a block are allocated
580 with this flag. KEEP values of 2 or 3 were needed respectively
581 for variables whose lifetime is controlled by CLEANUP_POINT_EXPRs
582 or for SAVE_EXPRs, but they are now unused.
584 TYPE is the type that will be used for the stack slot. */
587 assign_stack_temp_for_type (enum machine_mode mode, HOST_WIDE_INT size,
591 struct temp_slot *p, *best_p = 0, *selected = NULL, **pp;
594 /* If SIZE is -1 it means that somebody tried to allocate a temporary
595 of a variable size. */
596 gcc_assert (size != -1);
598 /* These are now unused. */
599 gcc_assert (keep <= 1);
601 align = get_stack_local_alignment (type, mode);
603 /* Try to find an available, already-allocated temporary of the proper
604 mode which meets the size and alignment requirements. Choose the
605 smallest one with the closest alignment.
607 If assign_stack_temp is called outside of the tree->rtl expansion,
608 we cannot reuse the stack slots (that may still refer to
609 VIRTUAL_STACK_VARS_REGNUM). */
610 if (!virtuals_instantiated)
612 for (p = avail_temp_slots; p; p = p->next)
614 if (p->align >= align && p->size >= size
615 && GET_MODE (p->slot) == mode
616 && objects_must_conflict_p (p->type, type)
617 && (best_p == 0 || best_p->size > p->size
618 || (best_p->size == p->size && best_p->align > p->align)))
620 if (p->align == align && p->size == size)
623 cut_slot_from_list (selected, &avail_temp_slots);
632 /* Make our best, if any, the one to use. */
636 cut_slot_from_list (selected, &avail_temp_slots);
638 /* If there are enough aligned bytes left over, make them into a new
639 temp_slot so that the extra bytes don't get wasted. Do this only
640 for BLKmode slots, so that we can be sure of the alignment. */
641 if (GET_MODE (best_p->slot) == BLKmode)
643 int alignment = best_p->align / BITS_PER_UNIT;
644 HOST_WIDE_INT rounded_size = CEIL_ROUND (size, alignment);
646 if (best_p->size - rounded_size >= alignment)
648 p = GGC_NEW (struct temp_slot);
649 p->in_use = p->addr_taken = 0;
650 p->size = best_p->size - rounded_size;
651 p->base_offset = best_p->base_offset + rounded_size;
652 p->full_size = best_p->full_size - rounded_size;
653 p->slot = adjust_address_nv (best_p->slot, BLKmode, rounded_size);
654 p->align = best_p->align;
656 p->type = best_p->type;
657 insert_slot_to_list (p, &avail_temp_slots);
659 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, p->slot,
662 best_p->size = rounded_size;
663 best_p->full_size = rounded_size;
668 /* If we still didn't find one, make a new temporary. */
671 HOST_WIDE_INT frame_offset_old = frame_offset;
673 p = GGC_NEW (struct temp_slot);
675 /* We are passing an explicit alignment request to assign_stack_local.
676 One side effect of that is assign_stack_local will not round SIZE
677 to ensure the frame offset remains suitably aligned.
679 So for requests which depended on the rounding of SIZE, we go ahead
680 and round it now. We also make sure ALIGNMENT is at least
681 BIGGEST_ALIGNMENT. */
682 gcc_assert (mode != BLKmode || align == BIGGEST_ALIGNMENT);
683 p->slot = assign_stack_local (mode,
685 ? CEIL_ROUND (size, (int) align / BITS_PER_UNIT)
691 /* The following slot size computation is necessary because we don't
692 know the actual size of the temporary slot until assign_stack_local
693 has performed all the frame alignment and size rounding for the
694 requested temporary. Note that extra space added for alignment
695 can be either above or below this stack slot depending on which
696 way the frame grows. We include the extra space if and only if it
697 is above this slot. */
698 if (FRAME_GROWS_DOWNWARD)
699 p->size = frame_offset_old - frame_offset;
703 /* Now define the fields used by combine_temp_slots. */
704 if (FRAME_GROWS_DOWNWARD)
706 p->base_offset = frame_offset;
707 p->full_size = frame_offset_old - frame_offset;
711 p->base_offset = frame_offset_old;
712 p->full_size = frame_offset - frame_offset_old;
723 p->level = temp_slot_level;
726 pp = temp_slots_at_level (p->level);
727 insert_slot_to_list (p, pp);
729 /* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
730 slot = gen_rtx_MEM (mode, XEXP (p->slot, 0));
731 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, slot, stack_slot_list);
733 /* If we know the alias set for the memory that will be used, use
734 it. If there's no TYPE, then we don't know anything about the
735 alias set for the memory. */
736 set_mem_alias_set (slot, type ? get_alias_set (type) : 0);
737 set_mem_align (slot, align);
739 /* If a type is specified, set the relevant flags. */
742 MEM_VOLATILE_P (slot) = TYPE_VOLATILE (type);
743 MEM_SET_IN_STRUCT_P (slot, (AGGREGATE_TYPE_P (type)
744 || TREE_CODE (type) == COMPLEX_TYPE));
746 MEM_NOTRAP_P (slot) = 1;
751 /* Allocate a temporary stack slot and record it for possible later
752 reuse. First three arguments are same as in preceding function. */
755 assign_stack_temp (enum machine_mode mode, HOST_WIDE_INT size, int keep)
757 return assign_stack_temp_for_type (mode, size, keep, NULL_TREE);
760 /* Assign a temporary.
761 If TYPE_OR_DECL is a decl, then we are doing it on behalf of the decl
762 and so that should be used in error messages. In either case, we
763 allocate of the given type.
764 KEEP is as for assign_stack_temp.
765 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
766 it is 0 if a register is OK.
767 DONT_PROMOTE is 1 if we should not promote values in register
771 assign_temp (tree type_or_decl, int keep, int memory_required,
772 int dont_promote ATTRIBUTE_UNUSED)
775 enum machine_mode mode;
780 if (DECL_P (type_or_decl))
781 decl = type_or_decl, type = TREE_TYPE (decl);
783 decl = NULL, type = type_or_decl;
785 mode = TYPE_MODE (type);
787 unsignedp = TYPE_UNSIGNED (type);
790 if (mode == BLKmode || memory_required)
792 HOST_WIDE_INT size = int_size_in_bytes (type);
795 /* Zero sized arrays are GNU C extension. Set size to 1 to avoid
796 problems with allocating the stack space. */
800 /* Unfortunately, we don't yet know how to allocate variable-sized
801 temporaries. However, sometimes we can find a fixed upper limit on
802 the size, so try that instead. */
804 size = max_int_size_in_bytes (type);
806 /* The size of the temporary may be too large to fit into an integer. */
807 /* ??? Not sure this should happen except for user silliness, so limit
808 this to things that aren't compiler-generated temporaries. The
809 rest of the time we'll die in assign_stack_temp_for_type. */
810 if (decl && size == -1
811 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST)
813 error ("size of variable %q+D is too large", decl);
817 tmp = assign_stack_temp_for_type (mode, size, keep, type);
823 mode = promote_mode (type, mode, &unsignedp, 0);
826 return gen_reg_rtx (mode);
829 /* Combine temporary stack slots which are adjacent on the stack.
831 This allows for better use of already allocated stack space. This is only
832 done for BLKmode slots because we can be sure that we won't have alignment
833 problems in this case. */
836 combine_temp_slots (void)
838 struct temp_slot *p, *q, *next, *next_q;
841 /* We can't combine slots, because the information about which slot
842 is in which alias set will be lost. */
843 if (flag_strict_aliasing)
846 /* If there are a lot of temp slots, don't do anything unless
847 high levels of optimization. */
848 if (! flag_expensive_optimizations)
849 for (p = avail_temp_slots, num_slots = 0; p; p = p->next, num_slots++)
850 if (num_slots > 100 || (num_slots > 10 && optimize == 0))
853 for (p = avail_temp_slots; p; p = next)
859 if (GET_MODE (p->slot) != BLKmode)
862 for (q = p->next; q; q = next_q)
868 if (GET_MODE (q->slot) != BLKmode)
871 if (p->base_offset + p->full_size == q->base_offset)
873 /* Q comes after P; combine Q into P. */
875 p->full_size += q->full_size;
878 else if (q->base_offset + q->full_size == p->base_offset)
880 /* P comes after Q; combine P into Q. */
882 q->full_size += p->full_size;
887 cut_slot_from_list (q, &avail_temp_slots);
890 /* Either delete P or advance past it. */
892 cut_slot_from_list (p, &avail_temp_slots);
896 /* Find the temp slot corresponding to the object at address X. */
898 static struct temp_slot *
899 find_temp_slot_from_address (rtx x)
905 for (i = max_slot_level (); i >= 0; i--)
906 for (p = *temp_slots_at_level (i); p; p = p->next)
908 if (XEXP (p->slot, 0) == x
910 || (GET_CODE (x) == PLUS
911 && XEXP (x, 0) == virtual_stack_vars_rtx
912 && GET_CODE (XEXP (x, 1)) == CONST_INT
913 && INTVAL (XEXP (x, 1)) >= p->base_offset
914 && INTVAL (XEXP (x, 1)) < p->base_offset + p->full_size))
917 else if (p->address != 0 && GET_CODE (p->address) == EXPR_LIST)
918 for (next = p->address; next; next = XEXP (next, 1))
919 if (XEXP (next, 0) == x)
923 /* If we have a sum involving a register, see if it points to a temp
925 if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 0))
926 && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
928 else if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 1))
929 && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
935 /* Indicate that NEW_RTX is an alternate way of referring to the temp
936 slot that previously was known by OLD_RTX. */
939 update_temp_slot_address (rtx old_rtx, rtx new_rtx)
943 if (rtx_equal_p (old_rtx, new_rtx))
946 p = find_temp_slot_from_address (old_rtx);
948 /* If we didn't find one, see if both OLD_RTX is a PLUS. If so, and
949 NEW_RTX is a register, see if one operand of the PLUS is a
950 temporary location. If so, NEW_RTX points into it. Otherwise,
951 if both OLD_RTX and NEW_RTX are a PLUS and if there is a register
952 in common between them. If so, try a recursive call on those
956 if (GET_CODE (old_rtx) != PLUS)
961 update_temp_slot_address (XEXP (old_rtx, 0), new_rtx);
962 update_temp_slot_address (XEXP (old_rtx, 1), new_rtx);
965 else if (GET_CODE (new_rtx) != PLUS)
968 if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 0)))
969 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 1));
970 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 0)))
971 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 1));
972 else if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 1)))
973 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 0));
974 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 1)))
975 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 0));
980 /* Otherwise add an alias for the temp's address. */
981 else if (p->address == 0)
982 p->address = new_rtx;
985 if (GET_CODE (p->address) != EXPR_LIST)
986 p->address = gen_rtx_EXPR_LIST (VOIDmode, p->address, NULL_RTX);
988 p->address = gen_rtx_EXPR_LIST (VOIDmode, new_rtx, p->address);
992 /* If X could be a reference to a temporary slot, mark the fact that its
993 address was taken. */
996 mark_temp_addr_taken (rtx x)
1003 /* If X is not in memory or is at a constant address, it cannot be in
1004 a temporary slot. */
1005 if (!MEM_P (x) || CONSTANT_P (XEXP (x, 0)))
1008 p = find_temp_slot_from_address (XEXP (x, 0));
1013 /* If X could be a reference to a temporary slot, mark that slot as
1014 belonging to the to one level higher than the current level. If X
1015 matched one of our slots, just mark that one. Otherwise, we can't
1016 easily predict which it is, so upgrade all of them. Kept slots
1017 need not be touched.
1019 This is called when an ({...}) construct occurs and a statement
1020 returns a value in memory. */
1023 preserve_temp_slots (rtx x)
1025 struct temp_slot *p = 0, *next;
1027 /* If there is no result, we still might have some objects whose address
1028 were taken, so we need to make sure they stay around. */
1031 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1036 move_slot_to_level (p, temp_slot_level - 1);
1042 /* If X is a register that is being used as a pointer, see if we have
1043 a temporary slot we know it points to. To be consistent with
1044 the code below, we really should preserve all non-kept slots
1045 if we can't find a match, but that seems to be much too costly. */
1046 if (REG_P (x) && REG_POINTER (x))
1047 p = find_temp_slot_from_address (x);
1049 /* If X is not in memory or is at a constant address, it cannot be in
1050 a temporary slot, but it can contain something whose address was
1052 if (p == 0 && (!MEM_P (x) || CONSTANT_P (XEXP (x, 0))))
1054 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1059 move_slot_to_level (p, temp_slot_level - 1);
1065 /* First see if we can find a match. */
1067 p = find_temp_slot_from_address (XEXP (x, 0));
1071 /* Move everything at our level whose address was taken to our new
1072 level in case we used its address. */
1073 struct temp_slot *q;
1075 if (p->level == temp_slot_level)
1077 for (q = *temp_slots_at_level (temp_slot_level); q; q = next)
1081 if (p != q && q->addr_taken)
1082 move_slot_to_level (q, temp_slot_level - 1);
1085 move_slot_to_level (p, temp_slot_level - 1);
1091 /* Otherwise, preserve all non-kept slots at this level. */
1092 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1097 move_slot_to_level (p, temp_slot_level - 1);
1101 /* Free all temporaries used so far. This is normally called at the
1102 end of generating code for a statement. */
1105 free_temp_slots (void)
1107 struct temp_slot *p, *next;
1109 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1114 make_slot_available (p);
1117 combine_temp_slots ();
1120 /* Push deeper into the nesting level for stack temporaries. */
1123 push_temp_slots (void)
1128 /* Pop a temporary nesting level. All slots in use in the current level
1132 pop_temp_slots (void)
1134 struct temp_slot *p, *next;
1136 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1139 make_slot_available (p);
1142 combine_temp_slots ();
1147 /* Initialize temporary slots. */
1150 init_temp_slots (void)
1152 /* We have not allocated any temporaries yet. */
1153 avail_temp_slots = 0;
1154 used_temp_slots = 0;
1155 temp_slot_level = 0;
1158 /* These routines are responsible for converting virtual register references
1159 to the actual hard register references once RTL generation is complete.
1161 The following four variables are used for communication between the
1162 routines. They contain the offsets of the virtual registers from their
1163 respective hard registers. */
1165 static int in_arg_offset;
1166 static int var_offset;
1167 static int dynamic_offset;
1168 static int out_arg_offset;
1169 static int cfa_offset;
1171 /* In most machines, the stack pointer register is equivalent to the bottom
1174 #ifndef STACK_POINTER_OFFSET
1175 #define STACK_POINTER_OFFSET 0
1178 /* If not defined, pick an appropriate default for the offset of dynamically
1179 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
1180 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
1182 #ifndef STACK_DYNAMIC_OFFSET
1184 /* The bottom of the stack points to the actual arguments. If
1185 REG_PARM_STACK_SPACE is defined, this includes the space for the register
1186 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
1187 stack space for register parameters is not pushed by the caller, but
1188 rather part of the fixed stack areas and hence not included in
1189 `crtl->outgoing_args_size'. Nevertheless, we must allow
1190 for it when allocating stack dynamic objects. */
1192 #if defined(REG_PARM_STACK_SPACE)
1193 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1194 ((ACCUMULATE_OUTGOING_ARGS \
1195 ? (crtl->outgoing_args_size \
1196 + (OUTGOING_REG_PARM_STACK_SPACE ((!(FNDECL) ? NULL_TREE : TREE_TYPE (FNDECL))) ? 0 \
1197 : REG_PARM_STACK_SPACE (FNDECL))) \
1198 : 0) + (STACK_POINTER_OFFSET))
1200 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1201 ((ACCUMULATE_OUTGOING_ARGS ? crtl->outgoing_args_size : 0) \
1202 + (STACK_POINTER_OFFSET))
1207 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
1208 is a virtual register, return the equivalent hard register and set the
1209 offset indirectly through the pointer. Otherwise, return 0. */
1212 instantiate_new_reg (rtx x, HOST_WIDE_INT *poffset)
1215 HOST_WIDE_INT offset;
1217 if (x == virtual_incoming_args_rtx)
1219 if (stack_realign_drap)
1221 /* Replace virtual_incoming_args_rtx with internal arg
1222 pointer if DRAP is used to realign stack. */
1223 new_rtx = crtl->args.internal_arg_pointer;
1227 new_rtx = arg_pointer_rtx, offset = in_arg_offset;
1229 else if (x == virtual_stack_vars_rtx)
1230 new_rtx = frame_pointer_rtx, offset = var_offset;
1231 else if (x == virtual_stack_dynamic_rtx)
1232 new_rtx = stack_pointer_rtx, offset = dynamic_offset;
1233 else if (x == virtual_outgoing_args_rtx)
1234 new_rtx = stack_pointer_rtx, offset = out_arg_offset;
1235 else if (x == virtual_cfa_rtx)
1237 #ifdef FRAME_POINTER_CFA_OFFSET
1238 new_rtx = frame_pointer_rtx;
1240 new_rtx = arg_pointer_rtx;
1242 offset = cfa_offset;
1251 /* A subroutine of instantiate_virtual_regs, called via for_each_rtx.
1252 Instantiate any virtual registers present inside of *LOC. The expression
1253 is simplified, as much as possible, but is not to be considered "valid"
1254 in any sense implied by the target. If any change is made, set CHANGED
1258 instantiate_virtual_regs_in_rtx (rtx *loc, void *data)
1260 HOST_WIDE_INT offset;
1261 bool *changed = (bool *) data;
1268 switch (GET_CODE (x))
1271 new_rtx = instantiate_new_reg (x, &offset);
1274 *loc = plus_constant (new_rtx, offset);
1281 new_rtx = instantiate_new_reg (XEXP (x, 0), &offset);
1284 new_rtx = plus_constant (new_rtx, offset);
1285 *loc = simplify_gen_binary (PLUS, GET_MODE (x), new_rtx, XEXP (x, 1));
1291 /* FIXME -- from old code */
1292 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
1293 we can commute the PLUS and SUBREG because pointers into the
1294 frame are well-behaved. */
1304 /* A subroutine of instantiate_virtual_regs_in_insn. Return true if X
1305 matches the predicate for insn CODE operand OPERAND. */
1308 safe_insn_predicate (int code, int operand, rtx x)
1310 const struct insn_operand_data *op_data;
1315 op_data = &insn_data[code].operand[operand];
1316 if (op_data->predicate == NULL)
1319 return op_data->predicate (x, op_data->mode);
1322 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1323 registers present inside of insn. The result will be a valid insn. */
1326 instantiate_virtual_regs_in_insn (rtx insn)
1328 HOST_WIDE_INT offset;
1330 bool any_change = false;
1331 rtx set, new_rtx, x, seq;
1333 /* There are some special cases to be handled first. */
1334 set = single_set (insn);
1337 /* We're allowed to assign to a virtual register. This is interpreted
1338 to mean that the underlying register gets assigned the inverse
1339 transformation. This is used, for example, in the handling of
1341 new_rtx = instantiate_new_reg (SET_DEST (set), &offset);
1346 for_each_rtx (&SET_SRC (set), instantiate_virtual_regs_in_rtx, NULL);
1347 x = simplify_gen_binary (PLUS, GET_MODE (new_rtx), SET_SRC (set),
1349 x = force_operand (x, new_rtx);
1351 emit_move_insn (new_rtx, x);
1356 emit_insn_before (seq, insn);
1361 /* Handle a straight copy from a virtual register by generating a
1362 new add insn. The difference between this and falling through
1363 to the generic case is avoiding a new pseudo and eliminating a
1364 move insn in the initial rtl stream. */
1365 new_rtx = instantiate_new_reg (SET_SRC (set), &offset);
1366 if (new_rtx && offset != 0
1367 && REG_P (SET_DEST (set))
1368 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1372 x = expand_simple_binop (GET_MODE (SET_DEST (set)), PLUS,
1373 new_rtx, GEN_INT (offset), SET_DEST (set),
1374 1, OPTAB_LIB_WIDEN);
1375 if (x != SET_DEST (set))
1376 emit_move_insn (SET_DEST (set), x);
1381 emit_insn_before (seq, insn);
1386 extract_insn (insn);
1387 insn_code = INSN_CODE (insn);
1389 /* Handle a plus involving a virtual register by determining if the
1390 operands remain valid if they're modified in place. */
1391 if (GET_CODE (SET_SRC (set)) == PLUS
1392 && recog_data.n_operands >= 3
1393 && recog_data.operand_loc[1] == &XEXP (SET_SRC (set), 0)
1394 && recog_data.operand_loc[2] == &XEXP (SET_SRC (set), 1)
1395 && GET_CODE (recog_data.operand[2]) == CONST_INT
1396 && (new_rtx = instantiate_new_reg (recog_data.operand[1], &offset)))
1398 offset += INTVAL (recog_data.operand[2]);
1400 /* If the sum is zero, then replace with a plain move. */
1402 && REG_P (SET_DEST (set))
1403 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1406 emit_move_insn (SET_DEST (set), new_rtx);
1410 emit_insn_before (seq, insn);
1415 x = gen_int_mode (offset, recog_data.operand_mode[2]);
1417 /* Using validate_change and apply_change_group here leaves
1418 recog_data in an invalid state. Since we know exactly what
1419 we want to check, do those two by hand. */
1420 if (safe_insn_predicate (insn_code, 1, new_rtx)
1421 && safe_insn_predicate (insn_code, 2, x))
1423 *recog_data.operand_loc[1] = recog_data.operand[1] = new_rtx;
1424 *recog_data.operand_loc[2] = recog_data.operand[2] = x;
1427 /* Fall through into the regular operand fixup loop in
1428 order to take care of operands other than 1 and 2. */
1434 extract_insn (insn);
1435 insn_code = INSN_CODE (insn);
1438 /* In the general case, we expect virtual registers to appear only in
1439 operands, and then only as either bare registers or inside memories. */
1440 for (i = 0; i < recog_data.n_operands; ++i)
1442 x = recog_data.operand[i];
1443 switch (GET_CODE (x))
1447 rtx addr = XEXP (x, 0);
1448 bool changed = false;
1450 for_each_rtx (&addr, instantiate_virtual_regs_in_rtx, &changed);
1455 x = replace_equiv_address (x, addr);
1456 /* It may happen that the address with the virtual reg
1457 was valid (e.g. based on the virtual stack reg, which might
1458 be acceptable to the predicates with all offsets), whereas
1459 the address now isn't anymore, for instance when the address
1460 is still offsetted, but the base reg isn't virtual-stack-reg
1461 anymore. Below we would do a force_reg on the whole operand,
1462 but this insn might actually only accept memory. Hence,
1463 before doing that last resort, try to reload the address into
1464 a register, so this operand stays a MEM. */
1465 if (!safe_insn_predicate (insn_code, i, x))
1467 addr = force_reg (GET_MODE (addr), addr);
1468 x = replace_equiv_address (x, addr);
1473 emit_insn_before (seq, insn);
1478 new_rtx = instantiate_new_reg (x, &offset);
1479 if (new_rtx == NULL)
1487 /* Careful, special mode predicates may have stuff in
1488 insn_data[insn_code].operand[i].mode that isn't useful
1489 to us for computing a new value. */
1490 /* ??? Recognize address_operand and/or "p" constraints
1491 to see if (plus new offset) is a valid before we put
1492 this through expand_simple_binop. */
1493 x = expand_simple_binop (GET_MODE (x), PLUS, new_rtx,
1494 GEN_INT (offset), NULL_RTX,
1495 1, OPTAB_LIB_WIDEN);
1498 emit_insn_before (seq, insn);
1503 new_rtx = instantiate_new_reg (SUBREG_REG (x), &offset);
1504 if (new_rtx == NULL)
1509 new_rtx = expand_simple_binop (GET_MODE (new_rtx), PLUS, new_rtx,
1510 GEN_INT (offset), NULL_RTX,
1511 1, OPTAB_LIB_WIDEN);
1514 emit_insn_before (seq, insn);
1516 x = simplify_gen_subreg (recog_data.operand_mode[i], new_rtx,
1517 GET_MODE (new_rtx), SUBREG_BYTE (x));
1525 /* At this point, X contains the new value for the operand.
1526 Validate the new value vs the insn predicate. Note that
1527 asm insns will have insn_code -1 here. */
1528 if (!safe_insn_predicate (insn_code, i, x))
1531 x = force_reg (insn_data[insn_code].operand[i].mode, x);
1535 emit_insn_before (seq, insn);
1538 *recog_data.operand_loc[i] = recog_data.operand[i] = x;
1544 /* Propagate operand changes into the duplicates. */
1545 for (i = 0; i < recog_data.n_dups; ++i)
1546 *recog_data.dup_loc[i]
1547 = copy_rtx (recog_data.operand[(unsigned)recog_data.dup_num[i]]);
1549 /* Force re-recognition of the instruction for validation. */
1550 INSN_CODE (insn) = -1;
1553 if (asm_noperands (PATTERN (insn)) >= 0)
1555 if (!check_asm_operands (PATTERN (insn)))
1557 error_for_asm (insn, "impossible constraint in %<asm%>");
1563 if (recog_memoized (insn) < 0)
1564 fatal_insn_not_found (insn);
1568 /* Subroutine of instantiate_decls. Given RTL representing a decl,
1569 do any instantiation required. */
1572 instantiate_decl_rtl (rtx x)
1579 /* If this is a CONCAT, recurse for the pieces. */
1580 if (GET_CODE (x) == CONCAT)
1582 instantiate_decl_rtl (XEXP (x, 0));
1583 instantiate_decl_rtl (XEXP (x, 1));
1587 /* If this is not a MEM, no need to do anything. Similarly if the
1588 address is a constant or a register that is not a virtual register. */
1593 if (CONSTANT_P (addr)
1595 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
1596 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
1599 for_each_rtx (&XEXP (x, 0), instantiate_virtual_regs_in_rtx, NULL);
1602 /* Helper for instantiate_decls called via walk_tree: Process all decls
1603 in the given DECL_VALUE_EXPR. */
1606 instantiate_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1612 if (DECL_P (t) && DECL_RTL_SET_P (t))
1613 instantiate_decl_rtl (DECL_RTL (t));
1618 /* Subroutine of instantiate_decls: Process all decls in the given
1619 BLOCK node and all its subblocks. */
1622 instantiate_decls_1 (tree let)
1626 for (t = BLOCK_VARS (let); t; t = TREE_CHAIN (t))
1628 if (DECL_RTL_SET_P (t))
1629 instantiate_decl_rtl (DECL_RTL (t));
1630 if (TREE_CODE (t) == VAR_DECL && DECL_HAS_VALUE_EXPR_P (t))
1632 tree v = DECL_VALUE_EXPR (t);
1633 walk_tree (&v, instantiate_expr, NULL, NULL);
1637 /* Process all subblocks. */
1638 for (t = BLOCK_SUBBLOCKS (let); t; t = BLOCK_CHAIN (t))
1639 instantiate_decls_1 (t);
1642 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1643 all virtual registers in their DECL_RTL's. */
1646 instantiate_decls (tree fndecl)
1650 /* Process all parameters of the function. */
1651 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = TREE_CHAIN (decl))
1653 instantiate_decl_rtl (DECL_RTL (decl));
1654 instantiate_decl_rtl (DECL_INCOMING_RTL (decl));
1655 if (DECL_HAS_VALUE_EXPR_P (decl))
1657 tree v = DECL_VALUE_EXPR (decl);
1658 walk_tree (&v, instantiate_expr, NULL, NULL);
1662 /* Now process all variables defined in the function or its subblocks. */
1663 instantiate_decls_1 (DECL_INITIAL (fndecl));
1666 /* Pass through the INSNS of function FNDECL and convert virtual register
1667 references to hard register references. */
1670 instantiate_virtual_regs (void)
1674 /* Compute the offsets to use for this function. */
1675 in_arg_offset = FIRST_PARM_OFFSET (current_function_decl);
1676 var_offset = STARTING_FRAME_OFFSET;
1677 dynamic_offset = STACK_DYNAMIC_OFFSET (current_function_decl);
1678 out_arg_offset = STACK_POINTER_OFFSET;
1679 #ifdef FRAME_POINTER_CFA_OFFSET
1680 cfa_offset = FRAME_POINTER_CFA_OFFSET (current_function_decl);
1682 cfa_offset = ARG_POINTER_CFA_OFFSET (current_function_decl);
1685 /* Initialize recognition, indicating that volatile is OK. */
1688 /* Scan through all the insns, instantiating every virtual register still
1690 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
1693 /* These patterns in the instruction stream can never be recognized.
1694 Fortunately, they shouldn't contain virtual registers either. */
1695 if (GET_CODE (PATTERN (insn)) == USE
1696 || GET_CODE (PATTERN (insn)) == CLOBBER
1697 || GET_CODE (PATTERN (insn)) == ADDR_VEC
1698 || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC
1699 || GET_CODE (PATTERN (insn)) == ASM_INPUT)
1702 instantiate_virtual_regs_in_insn (insn);
1704 if (INSN_DELETED_P (insn))
1707 for_each_rtx (®_NOTES (insn), instantiate_virtual_regs_in_rtx, NULL);
1709 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
1710 if (GET_CODE (insn) == CALL_INSN)
1711 for_each_rtx (&CALL_INSN_FUNCTION_USAGE (insn),
1712 instantiate_virtual_regs_in_rtx, NULL);
1715 /* Instantiate the virtual registers in the DECLs for debugging purposes. */
1716 instantiate_decls (current_function_decl);
1718 targetm.instantiate_decls ();
1720 /* Indicate that, from now on, assign_stack_local should use
1721 frame_pointer_rtx. */
1722 virtuals_instantiated = 1;
1726 struct rtl_opt_pass pass_instantiate_virtual_regs =
1732 instantiate_virtual_regs, /* execute */
1735 0, /* static_pass_number */
1737 0, /* properties_required */
1738 0, /* properties_provided */
1739 0, /* properties_destroyed */
1740 0, /* todo_flags_start */
1741 TODO_dump_func /* todo_flags_finish */
1746 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
1747 This means a type for which function calls must pass an address to the
1748 function or get an address back from the function.
1749 EXP may be a type node or an expression (whose type is tested). */
1752 aggregate_value_p (const_tree exp, const_tree fntype)
1754 int i, regno, nregs;
1757 const_tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
1759 /* DECL node associated with FNTYPE when relevant, which we might need to
1760 check for by-invisible-reference returns, typically for CALL_EXPR input
1762 const_tree fndecl = NULL_TREE;
1765 switch (TREE_CODE (fntype))
1768 fndecl = get_callee_fndecl (fntype);
1769 fntype = fndecl ? TREE_TYPE (fndecl) : 0;
1773 fntype = TREE_TYPE (fndecl);
1778 case IDENTIFIER_NODE:
1782 /* We don't expect other rtl types here. */
1786 if (TREE_CODE (type) == VOID_TYPE)
1789 /* If the front end has decided that this needs to be passed by
1790 reference, do so. */
1791 if ((TREE_CODE (exp) == PARM_DECL || TREE_CODE (exp) == RESULT_DECL)
1792 && DECL_BY_REFERENCE (exp))
1795 /* If the EXPression is a CALL_EXPR, honor DECL_BY_REFERENCE set on the
1796 called function RESULT_DECL, meaning the function returns in memory by
1797 invisible reference. This check lets front-ends not set TREE_ADDRESSABLE
1798 on the function type, which used to be the way to request such a return
1799 mechanism but might now be causing troubles at gimplification time if
1800 temporaries with the function type need to be created. */
1801 if (TREE_CODE (exp) == CALL_EXPR && fndecl && DECL_RESULT (fndecl)
1802 && DECL_BY_REFERENCE (DECL_RESULT (fndecl)))
1805 if (targetm.calls.return_in_memory (type, fntype))
1807 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
1808 and thus can't be returned in registers. */
1809 if (TREE_ADDRESSABLE (type))
1811 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
1813 /* Make sure we have suitable call-clobbered regs to return
1814 the value in; if not, we must return it in memory. */
1815 reg = hard_function_value (type, 0, fntype, 0);
1817 /* If we have something other than a REG (e.g. a PARALLEL), then assume
1822 regno = REGNO (reg);
1823 nregs = hard_regno_nregs[regno][TYPE_MODE (type)];
1824 for (i = 0; i < nregs; i++)
1825 if (! call_used_regs[regno + i])
1830 /* Return true if we should assign DECL a pseudo register; false if it
1831 should live on the local stack. */
1834 use_register_for_decl (const_tree decl)
1836 if (!targetm.calls.allocate_stack_slots_for_args())
1839 /* Honor volatile. */
1840 if (TREE_SIDE_EFFECTS (decl))
1843 /* Honor addressability. */
1844 if (TREE_ADDRESSABLE (decl))
1847 /* Only register-like things go in registers. */
1848 if (DECL_MODE (decl) == BLKmode)
1851 /* If -ffloat-store specified, don't put explicit float variables
1853 /* ??? This should be checked after DECL_ARTIFICIAL, but tree-ssa
1854 propagates values across these stores, and it probably shouldn't. */
1855 if (flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)))
1858 /* If we're not interested in tracking debugging information for
1859 this decl, then we can certainly put it in a register. */
1860 if (DECL_IGNORED_P (decl))
1863 return (optimize || DECL_REGISTER (decl));
1866 /* Return true if TYPE should be passed by invisible reference. */
1869 pass_by_reference (CUMULATIVE_ARGS *ca, enum machine_mode mode,
1870 tree type, bool named_arg)
1874 /* If this type contains non-trivial constructors, then it is
1875 forbidden for the middle-end to create any new copies. */
1876 if (TREE_ADDRESSABLE (type))
1879 /* GCC post 3.4 passes *all* variable sized types by reference. */
1880 if (!TYPE_SIZE (type) || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
1884 return targetm.calls.pass_by_reference (ca, mode, type, named_arg);
1887 /* Return true if TYPE, which is passed by reference, should be callee
1888 copied instead of caller copied. */
1891 reference_callee_copied (CUMULATIVE_ARGS *ca, enum machine_mode mode,
1892 tree type, bool named_arg)
1894 if (type && TREE_ADDRESSABLE (type))
1896 return targetm.calls.callee_copies (ca, mode, type, named_arg);
1899 /* Structures to communicate between the subroutines of assign_parms.
1900 The first holds data persistent across all parameters, the second
1901 is cleared out for each parameter. */
1903 struct assign_parm_data_all
1905 CUMULATIVE_ARGS args_so_far;
1906 struct args_size stack_args_size;
1907 tree function_result_decl;
1909 rtx first_conversion_insn;
1910 rtx last_conversion_insn;
1911 HOST_WIDE_INT pretend_args_size;
1912 HOST_WIDE_INT extra_pretend_bytes;
1913 int reg_parm_stack_space;
1916 struct assign_parm_data_one
1922 enum machine_mode nominal_mode;
1923 enum machine_mode passed_mode;
1924 enum machine_mode promoted_mode;
1925 struct locate_and_pad_arg_data locate;
1927 BOOL_BITFIELD named_arg : 1;
1928 BOOL_BITFIELD passed_pointer : 1;
1929 BOOL_BITFIELD on_stack : 1;
1930 BOOL_BITFIELD loaded_in_reg : 1;
1933 /* A subroutine of assign_parms. Initialize ALL. */
1936 assign_parms_initialize_all (struct assign_parm_data_all *all)
1940 memset (all, 0, sizeof (*all));
1942 fntype = TREE_TYPE (current_function_decl);
1944 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
1945 INIT_CUMULATIVE_INCOMING_ARGS (all->args_so_far, fntype, NULL_RTX);
1947 INIT_CUMULATIVE_ARGS (all->args_so_far, fntype, NULL_RTX,
1948 current_function_decl, -1);
1951 #ifdef REG_PARM_STACK_SPACE
1952 all->reg_parm_stack_space = REG_PARM_STACK_SPACE (current_function_decl);
1956 /* If ARGS contains entries with complex types, split the entry into two
1957 entries of the component type. Return a new list of substitutions are
1958 needed, else the old list. */
1961 split_complex_args (tree args)
1965 /* Before allocating memory, check for the common case of no complex. */
1966 for (p = args; p; p = TREE_CHAIN (p))
1968 tree type = TREE_TYPE (p);
1969 if (TREE_CODE (type) == COMPLEX_TYPE
1970 && targetm.calls.split_complex_arg (type))
1976 args = copy_list (args);
1978 for (p = args; p; p = TREE_CHAIN (p))
1980 tree type = TREE_TYPE (p);
1981 if (TREE_CODE (type) == COMPLEX_TYPE
1982 && targetm.calls.split_complex_arg (type))
1985 tree subtype = TREE_TYPE (type);
1986 bool addressable = TREE_ADDRESSABLE (p);
1988 /* Rewrite the PARM_DECL's type with its component. */
1989 TREE_TYPE (p) = subtype;
1990 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
1991 DECL_MODE (p) = VOIDmode;
1992 DECL_SIZE (p) = NULL;
1993 DECL_SIZE_UNIT (p) = NULL;
1994 /* If this arg must go in memory, put it in a pseudo here.
1995 We can't allow it to go in memory as per normal parms,
1996 because the usual place might not have the imag part
1997 adjacent to the real part. */
1998 DECL_ARTIFICIAL (p) = addressable;
1999 DECL_IGNORED_P (p) = addressable;
2000 TREE_ADDRESSABLE (p) = 0;
2003 /* Build a second synthetic decl. */
2004 decl = build_decl (PARM_DECL, NULL_TREE, subtype);
2005 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
2006 DECL_ARTIFICIAL (decl) = addressable;
2007 DECL_IGNORED_P (decl) = addressable;
2008 layout_decl (decl, 0);
2010 /* Splice it in; skip the new decl. */
2011 TREE_CHAIN (decl) = TREE_CHAIN (p);
2012 TREE_CHAIN (p) = decl;
2020 /* A subroutine of assign_parms. Adjust the parameter list to incorporate
2021 the hidden struct return argument, and (abi willing) complex args.
2022 Return the new parameter list. */
2025 assign_parms_augmented_arg_list (struct assign_parm_data_all *all)
2027 tree fndecl = current_function_decl;
2028 tree fntype = TREE_TYPE (fndecl);
2029 tree fnargs = DECL_ARGUMENTS (fndecl);
2031 /* If struct value address is treated as the first argument, make it so. */
2032 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
2033 && ! cfun->returns_pcc_struct
2034 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
2036 tree type = build_pointer_type (TREE_TYPE (fntype));
2039 decl = build_decl (PARM_DECL, NULL_TREE, type);
2040 DECL_ARG_TYPE (decl) = type;
2041 DECL_ARTIFICIAL (decl) = 1;
2042 DECL_IGNORED_P (decl) = 1;
2044 TREE_CHAIN (decl) = fnargs;
2046 all->function_result_decl = decl;
2049 all->orig_fnargs = fnargs;
2051 /* If the target wants to split complex arguments into scalars, do so. */
2052 if (targetm.calls.split_complex_arg)
2053 fnargs = split_complex_args (fnargs);
2058 /* A subroutine of assign_parms. Examine PARM and pull out type and mode
2059 data for the parameter. Incorporate ABI specifics such as pass-by-
2060 reference and type promotion. */
2063 assign_parm_find_data_types (struct assign_parm_data_all *all, tree parm,
2064 struct assign_parm_data_one *data)
2066 tree nominal_type, passed_type;
2067 enum machine_mode nominal_mode, passed_mode, promoted_mode;
2069 memset (data, 0, sizeof (*data));
2071 /* NAMED_ARG is a misnomer. We really mean 'non-variadic'. */
2073 data->named_arg = 1; /* No variadic parms. */
2074 else if (TREE_CHAIN (parm))
2075 data->named_arg = 1; /* Not the last non-variadic parm. */
2076 else if (targetm.calls.strict_argument_naming (&all->args_so_far))
2077 data->named_arg = 1; /* Only variadic ones are unnamed. */
2079 data->named_arg = 0; /* Treat as variadic. */
2081 nominal_type = TREE_TYPE (parm);
2082 passed_type = DECL_ARG_TYPE (parm);
2084 /* Look out for errors propagating this far. Also, if the parameter's
2085 type is void then its value doesn't matter. */
2086 if (TREE_TYPE (parm) == error_mark_node
2087 /* This can happen after weird syntax errors
2088 or if an enum type is defined among the parms. */
2089 || TREE_CODE (parm) != PARM_DECL
2090 || passed_type == NULL
2091 || VOID_TYPE_P (nominal_type))
2093 nominal_type = passed_type = void_type_node;
2094 nominal_mode = passed_mode = promoted_mode = VOIDmode;
2098 /* Find mode of arg as it is passed, and mode of arg as it should be
2099 during execution of this function. */
2100 passed_mode = TYPE_MODE (passed_type);
2101 nominal_mode = TYPE_MODE (nominal_type);
2103 /* If the parm is to be passed as a transparent union, use the type of
2104 the first field for the tests below. We have already verified that
2105 the modes are the same. */
2106 if (TREE_CODE (passed_type) == UNION_TYPE
2107 && TYPE_TRANSPARENT_UNION (passed_type))
2108 passed_type = TREE_TYPE (TYPE_FIELDS (passed_type));
2110 /* See if this arg was passed by invisible reference. */
2111 if (pass_by_reference (&all->args_so_far, passed_mode,
2112 passed_type, data->named_arg))
2114 passed_type = nominal_type = build_pointer_type (passed_type);
2115 data->passed_pointer = true;
2116 passed_mode = nominal_mode = Pmode;
2119 /* Find mode as it is passed by the ABI. */
2120 promoted_mode = passed_mode;
2121 if (targetm.calls.promote_function_args (TREE_TYPE (current_function_decl)))
2123 int unsignedp = TYPE_UNSIGNED (passed_type);
2124 promoted_mode = promote_mode (passed_type, promoted_mode,
2129 data->nominal_type = nominal_type;
2130 data->passed_type = passed_type;
2131 data->nominal_mode = nominal_mode;
2132 data->passed_mode = passed_mode;
2133 data->promoted_mode = promoted_mode;
2136 /* A subroutine of assign_parms. Invoke setup_incoming_varargs. */
2139 assign_parms_setup_varargs (struct assign_parm_data_all *all,
2140 struct assign_parm_data_one *data, bool no_rtl)
2142 int varargs_pretend_bytes = 0;
2144 targetm.calls.setup_incoming_varargs (&all->args_so_far,
2145 data->promoted_mode,
2147 &varargs_pretend_bytes, no_rtl);
2149 /* If the back-end has requested extra stack space, record how much is
2150 needed. Do not change pretend_args_size otherwise since it may be
2151 nonzero from an earlier partial argument. */
2152 if (varargs_pretend_bytes > 0)
2153 all->pretend_args_size = varargs_pretend_bytes;
2156 /* A subroutine of assign_parms. Set DATA->ENTRY_PARM corresponding to
2157 the incoming location of the current parameter. */
2160 assign_parm_find_entry_rtl (struct assign_parm_data_all *all,
2161 struct assign_parm_data_one *data)
2163 HOST_WIDE_INT pretend_bytes = 0;
2167 if (data->promoted_mode == VOIDmode)
2169 data->entry_parm = data->stack_parm = const0_rtx;
2173 #ifdef FUNCTION_INCOMING_ARG
2174 entry_parm = FUNCTION_INCOMING_ARG (all->args_so_far, data->promoted_mode,
2175 data->passed_type, data->named_arg);
2177 entry_parm = FUNCTION_ARG (all->args_so_far, data->promoted_mode,
2178 data->passed_type, data->named_arg);
2181 if (entry_parm == 0)
2182 data->promoted_mode = data->passed_mode;
2184 /* Determine parm's home in the stack, in case it arrives in the stack
2185 or we should pretend it did. Compute the stack position and rtx where
2186 the argument arrives and its size.
2188 There is one complexity here: If this was a parameter that would
2189 have been passed in registers, but wasn't only because it is
2190 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2191 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2192 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of 0
2193 as it was the previous time. */
2194 in_regs = entry_parm != 0;
2195 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2198 if (!in_regs && !data->named_arg)
2200 if (targetm.calls.pretend_outgoing_varargs_named (&all->args_so_far))
2203 #ifdef FUNCTION_INCOMING_ARG
2204 tem = FUNCTION_INCOMING_ARG (all->args_so_far, data->promoted_mode,
2205 data->passed_type, true);
2207 tem = FUNCTION_ARG (all->args_so_far, data->promoted_mode,
2208 data->passed_type, true);
2210 in_regs = tem != NULL;
2214 /* If this parameter was passed both in registers and in the stack, use
2215 the copy on the stack. */
2216 if (targetm.calls.must_pass_in_stack (data->promoted_mode,
2224 partial = targetm.calls.arg_partial_bytes (&all->args_so_far,
2225 data->promoted_mode,
2228 data->partial = partial;
2230 /* The caller might already have allocated stack space for the
2231 register parameters. */
2232 if (partial != 0 && all->reg_parm_stack_space == 0)
2234 /* Part of this argument is passed in registers and part
2235 is passed on the stack. Ask the prologue code to extend
2236 the stack part so that we can recreate the full value.
2238 PRETEND_BYTES is the size of the registers we need to store.
2239 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
2240 stack space that the prologue should allocate.
2242 Internally, gcc assumes that the argument pointer is aligned
2243 to STACK_BOUNDARY bits. This is used both for alignment
2244 optimizations (see init_emit) and to locate arguments that are
2245 aligned to more than PARM_BOUNDARY bits. We must preserve this
2246 invariant by rounding CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to
2247 a stack boundary. */
2249 /* We assume at most one partial arg, and it must be the first
2250 argument on the stack. */
2251 gcc_assert (!all->extra_pretend_bytes && !all->pretend_args_size);
2253 pretend_bytes = partial;
2254 all->pretend_args_size = CEIL_ROUND (pretend_bytes, STACK_BYTES);
2256 /* We want to align relative to the actual stack pointer, so
2257 don't include this in the stack size until later. */
2258 all->extra_pretend_bytes = all->pretend_args_size;
2262 locate_and_pad_parm (data->promoted_mode, data->passed_type, in_regs,
2263 entry_parm ? data->partial : 0, current_function_decl,
2264 &all->stack_args_size, &data->locate);
2266 /* Update parm_stack_boundary if this parameter is passed in the
2268 if (!in_regs && crtl->parm_stack_boundary < data->locate.boundary)
2269 crtl->parm_stack_boundary = data->locate.boundary;
2271 /* Adjust offsets to include the pretend args. */
2272 pretend_bytes = all->extra_pretend_bytes - pretend_bytes;
2273 data->locate.slot_offset.constant += pretend_bytes;
2274 data->locate.offset.constant += pretend_bytes;
2276 data->entry_parm = entry_parm;
2279 /* A subroutine of assign_parms. If there is actually space on the stack
2280 for this parm, count it in stack_args_size and return true. */
2283 assign_parm_is_stack_parm (struct assign_parm_data_all *all,
2284 struct assign_parm_data_one *data)
2286 /* Trivially true if we've no incoming register. */
2287 if (data->entry_parm == NULL)
2289 /* Also true if we're partially in registers and partially not,
2290 since we've arranged to drop the entire argument on the stack. */
2291 else if (data->partial != 0)
2293 /* Also true if the target says that it's passed in both registers
2294 and on the stack. */
2295 else if (GET_CODE (data->entry_parm) == PARALLEL
2296 && XEXP (XVECEXP (data->entry_parm, 0, 0), 0) == NULL_RTX)
2298 /* Also true if the target says that there's stack allocated for
2299 all register parameters. */
2300 else if (all->reg_parm_stack_space > 0)
2302 /* Otherwise, no, this parameter has no ABI defined stack slot. */
2306 all->stack_args_size.constant += data->locate.size.constant;
2307 if (data->locate.size.var)
2308 ADD_PARM_SIZE (all->stack_args_size, data->locate.size.var);
2313 /* A subroutine of assign_parms. Given that this parameter is allocated
2314 stack space by the ABI, find it. */
2317 assign_parm_find_stack_rtl (tree parm, struct assign_parm_data_one *data)
2319 rtx offset_rtx, stack_parm;
2320 unsigned int align, boundary;
2322 /* If we're passing this arg using a reg, make its stack home the
2323 aligned stack slot. */
2324 if (data->entry_parm)
2325 offset_rtx = ARGS_SIZE_RTX (data->locate.slot_offset);
2327 offset_rtx = ARGS_SIZE_RTX (data->locate.offset);
2329 stack_parm = crtl->args.internal_arg_pointer;
2330 if (offset_rtx != const0_rtx)
2331 stack_parm = gen_rtx_PLUS (Pmode, stack_parm, offset_rtx);
2332 stack_parm = gen_rtx_MEM (data->promoted_mode, stack_parm);
2334 set_mem_attributes (stack_parm, parm, 1);
2335 /* set_mem_attributes could set MEM_SIZE to the passed mode's size,
2336 while promoted mode's size is needed. */
2337 if (data->promoted_mode != BLKmode
2338 && data->promoted_mode != DECL_MODE (parm))
2339 set_mem_size (stack_parm, GEN_INT (GET_MODE_SIZE (data->promoted_mode)));
2341 boundary = data->locate.boundary;
2342 align = BITS_PER_UNIT;
2344 /* If we're padding upward, we know that the alignment of the slot
2345 is FUNCTION_ARG_BOUNDARY. If we're using slot_offset, we're
2346 intentionally forcing upward padding. Otherwise we have to come
2347 up with a guess at the alignment based on OFFSET_RTX. */
2348 if (data->locate.where_pad != downward || data->entry_parm)
2350 else if (GET_CODE (offset_rtx) == CONST_INT)
2352 align = INTVAL (offset_rtx) * BITS_PER_UNIT | boundary;
2353 align = align & -align;
2355 set_mem_align (stack_parm, align);
2357 if (data->entry_parm)
2358 set_reg_attrs_for_parm (data->entry_parm, stack_parm);
2360 data->stack_parm = stack_parm;
2363 /* A subroutine of assign_parms. Adjust DATA->ENTRY_RTL such that it's
2364 always valid and contiguous. */
2367 assign_parm_adjust_entry_rtl (struct assign_parm_data_one *data)
2369 rtx entry_parm = data->entry_parm;
2370 rtx stack_parm = data->stack_parm;
2372 /* If this parm was passed part in regs and part in memory, pretend it
2373 arrived entirely in memory by pushing the register-part onto the stack.
2374 In the special case of a DImode or DFmode that is split, we could put
2375 it together in a pseudoreg directly, but for now that's not worth
2377 if (data->partial != 0)
2379 /* Handle calls that pass values in multiple non-contiguous
2380 locations. The Irix 6 ABI has examples of this. */
2381 if (GET_CODE (entry_parm) == PARALLEL)
2382 emit_group_store (validize_mem (stack_parm), entry_parm,
2384 int_size_in_bytes (data->passed_type));
2387 gcc_assert (data->partial % UNITS_PER_WORD == 0);
2388 move_block_from_reg (REGNO (entry_parm), validize_mem (stack_parm),
2389 data->partial / UNITS_PER_WORD);
2392 entry_parm = stack_parm;
2395 /* If we didn't decide this parm came in a register, by default it came
2397 else if (entry_parm == NULL)
2398 entry_parm = stack_parm;
2400 /* When an argument is passed in multiple locations, we can't make use
2401 of this information, but we can save some copying if the whole argument
2402 is passed in a single register. */
2403 else if (GET_CODE (entry_parm) == PARALLEL
2404 && data->nominal_mode != BLKmode
2405 && data->passed_mode != BLKmode)
2407 size_t i, len = XVECLEN (entry_parm, 0);
2409 for (i = 0; i < len; i++)
2410 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
2411 && REG_P (XEXP (XVECEXP (entry_parm, 0, i), 0))
2412 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
2413 == data->passed_mode)
2414 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
2416 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
2421 data->entry_parm = entry_parm;
2424 /* A subroutine of assign_parms. Reconstitute any values which were
2425 passed in multiple registers and would fit in a single register. */
2428 assign_parm_remove_parallels (struct assign_parm_data_one *data)
2430 rtx entry_parm = data->entry_parm;
2432 /* Convert the PARALLEL to a REG of the same mode as the parallel.
2433 This can be done with register operations rather than on the
2434 stack, even if we will store the reconstituted parameter on the
2436 if (GET_CODE (entry_parm) == PARALLEL && GET_MODE (entry_parm) != BLKmode)
2438 rtx parmreg = gen_reg_rtx (GET_MODE (entry_parm));
2439 emit_group_store (parmreg, entry_parm, NULL_TREE,
2440 GET_MODE_SIZE (GET_MODE (entry_parm)));
2441 entry_parm = parmreg;
2444 data->entry_parm = entry_parm;
2447 /* A subroutine of assign_parms. Adjust DATA->STACK_RTL such that it's
2448 always valid and properly aligned. */
2451 assign_parm_adjust_stack_rtl (struct assign_parm_data_one *data)
2453 rtx stack_parm = data->stack_parm;
2455 /* If we can't trust the parm stack slot to be aligned enough for its
2456 ultimate type, don't use that slot after entry. We'll make another
2457 stack slot, if we need one. */
2459 && ((STRICT_ALIGNMENT
2460 && GET_MODE_ALIGNMENT (data->nominal_mode) > MEM_ALIGN (stack_parm))
2461 || (data->nominal_type
2462 && TYPE_ALIGN (data->nominal_type) > MEM_ALIGN (stack_parm)
2463 && MEM_ALIGN (stack_parm) < PREFERRED_STACK_BOUNDARY)))
2466 /* If parm was passed in memory, and we need to convert it on entry,
2467 don't store it back in that same slot. */
2468 else if (data->entry_parm == stack_parm
2469 && data->nominal_mode != BLKmode
2470 && data->nominal_mode != data->passed_mode)
2473 /* If stack protection is in effect for this function, don't leave any
2474 pointers in their passed stack slots. */
2475 else if (crtl->stack_protect_guard
2476 && (flag_stack_protect == 2
2477 || data->passed_pointer
2478 || POINTER_TYPE_P (data->nominal_type)))
2481 data->stack_parm = stack_parm;
2484 /* A subroutine of assign_parms. Return true if the current parameter
2485 should be stored as a BLKmode in the current frame. */
2488 assign_parm_setup_block_p (struct assign_parm_data_one *data)
2490 if (data->nominal_mode == BLKmode)
2492 if (GET_MODE (data->entry_parm) == BLKmode)
2495 #ifdef BLOCK_REG_PADDING
2496 /* Only assign_parm_setup_block knows how to deal with register arguments
2497 that are padded at the least significant end. */
2498 if (REG_P (data->entry_parm)
2499 && GET_MODE_SIZE (data->promoted_mode) < UNITS_PER_WORD
2500 && (BLOCK_REG_PADDING (data->passed_mode, data->passed_type, 1)
2501 == (BYTES_BIG_ENDIAN ? upward : downward)))
2508 /* A subroutine of assign_parms. Arrange for the parameter to be
2509 present and valid in DATA->STACK_RTL. */
2512 assign_parm_setup_block (struct assign_parm_data_all *all,
2513 tree parm, struct assign_parm_data_one *data)
2515 rtx entry_parm = data->entry_parm;
2516 rtx stack_parm = data->stack_parm;
2518 HOST_WIDE_INT size_stored;
2520 if (GET_CODE (entry_parm) == PARALLEL)
2521 entry_parm = emit_group_move_into_temps (entry_parm);
2523 size = int_size_in_bytes (data->passed_type);
2524 size_stored = CEIL_ROUND (size, UNITS_PER_WORD);
2525 if (stack_parm == 0)
2527 DECL_ALIGN (parm) = MAX (DECL_ALIGN (parm), BITS_PER_WORD);
2528 stack_parm = assign_stack_local (BLKmode, size_stored,
2530 if (GET_MODE_SIZE (GET_MODE (entry_parm)) == size)
2531 PUT_MODE (stack_parm, GET_MODE (entry_parm));
2532 set_mem_attributes (stack_parm, parm, 1);
2535 /* If a BLKmode arrives in registers, copy it to a stack slot. Handle
2536 calls that pass values in multiple non-contiguous locations. */
2537 if (REG_P (entry_parm) || GET_CODE (entry_parm) == PARALLEL)
2541 /* Note that we will be storing an integral number of words.
2542 So we have to be careful to ensure that we allocate an
2543 integral number of words. We do this above when we call
2544 assign_stack_local if space was not allocated in the argument
2545 list. If it was, this will not work if PARM_BOUNDARY is not
2546 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2547 if it becomes a problem. Exception is when BLKmode arrives
2548 with arguments not conforming to word_mode. */
2550 if (data->stack_parm == 0)
2552 else if (GET_CODE (entry_parm) == PARALLEL)
2555 gcc_assert (!size || !(PARM_BOUNDARY % BITS_PER_WORD));
2557 mem = validize_mem (stack_parm);
2559 /* Handle values in multiple non-contiguous locations. */
2560 if (GET_CODE (entry_parm) == PARALLEL)
2562 push_to_sequence2 (all->first_conversion_insn,
2563 all->last_conversion_insn);
2564 emit_group_store (mem, entry_parm, data->passed_type, size);
2565 all->first_conversion_insn = get_insns ();
2566 all->last_conversion_insn = get_last_insn ();
2573 /* If SIZE is that of a mode no bigger than a word, just use
2574 that mode's store operation. */
2575 else if (size <= UNITS_PER_WORD)
2577 enum machine_mode mode
2578 = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
2581 #ifdef BLOCK_REG_PADDING
2582 && (size == UNITS_PER_WORD
2583 || (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2584 != (BYTES_BIG_ENDIAN ? upward : downward)))
2590 /* We are really truncating a word_mode value containing
2591 SIZE bytes into a value of mode MODE. If such an
2592 operation requires no actual instructions, we can refer
2593 to the value directly in mode MODE, otherwise we must
2594 start with the register in word_mode and explicitly
2596 if (TRULY_NOOP_TRUNCATION (size * BITS_PER_UNIT, BITS_PER_WORD))
2597 reg = gen_rtx_REG (mode, REGNO (entry_parm));
2600 reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
2601 reg = convert_to_mode (mode, copy_to_reg (reg), 1);
2603 emit_move_insn (change_address (mem, mode, 0), reg);
2606 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
2607 machine must be aligned to the left before storing
2608 to memory. Note that the previous test doesn't
2609 handle all cases (e.g. SIZE == 3). */
2610 else if (size != UNITS_PER_WORD
2611 #ifdef BLOCK_REG_PADDING
2612 && (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2620 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
2621 rtx reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
2623 x = expand_shift (LSHIFT_EXPR, word_mode, reg,
2624 build_int_cst (NULL_TREE, by),
2626 tem = change_address (mem, word_mode, 0);
2627 emit_move_insn (tem, x);
2630 move_block_from_reg (REGNO (entry_parm), mem,
2631 size_stored / UNITS_PER_WORD);
2634 move_block_from_reg (REGNO (entry_parm), mem,
2635 size_stored / UNITS_PER_WORD);
2637 else if (data->stack_parm == 0)
2639 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2640 emit_block_move (stack_parm, data->entry_parm, GEN_INT (size),
2642 all->first_conversion_insn = get_insns ();
2643 all->last_conversion_insn = get_last_insn ();
2647 data->stack_parm = stack_parm;
2648 SET_DECL_RTL (parm, stack_parm);
2651 /* A subroutine of assign_parms. Allocate a pseudo to hold the current
2652 parameter. Get it there. Perform all ABI specified conversions. */
2655 assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm,
2656 struct assign_parm_data_one *data)
2659 enum machine_mode promoted_nominal_mode;
2660 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (parm));
2661 bool did_conversion = false;
2663 /* Store the parm in a pseudoregister during the function, but we may
2664 need to do it in a wider mode. */
2666 /* This is not really promoting for a call. However we need to be
2667 consistent with assign_parm_find_data_types and expand_expr_real_1. */
2668 promoted_nominal_mode
2669 = promote_mode (data->nominal_type, data->nominal_mode, &unsignedp, 1);
2671 parmreg = gen_reg_rtx (promoted_nominal_mode);
2673 if (!DECL_ARTIFICIAL (parm))
2674 mark_user_reg (parmreg);
2676 /* If this was an item that we received a pointer to,
2677 set DECL_RTL appropriately. */
2678 if (data->passed_pointer)
2680 rtx x = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data->passed_type)), parmreg);
2681 set_mem_attributes (x, parm, 1);
2682 SET_DECL_RTL (parm, x);
2685 SET_DECL_RTL (parm, parmreg);
2687 assign_parm_remove_parallels (data);
2689 /* Copy the value into the register. */
2690 if (data->nominal_mode != data->passed_mode
2691 || promoted_nominal_mode != data->promoted_mode)
2695 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
2696 mode, by the caller. We now have to convert it to
2697 NOMINAL_MODE, if different. However, PARMREG may be in
2698 a different mode than NOMINAL_MODE if it is being stored
2701 If ENTRY_PARM is a hard register, it might be in a register
2702 not valid for operating in its mode (e.g., an odd-numbered
2703 register for a DFmode). In that case, moves are the only
2704 thing valid, so we can't do a convert from there. This
2705 occurs when the calling sequence allow such misaligned
2708 In addition, the conversion may involve a call, which could
2709 clobber parameters which haven't been copied to pseudo
2710 registers yet. Therefore, we must first copy the parm to
2711 a pseudo reg here, and save the conversion until after all
2712 parameters have been moved. */
2714 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
2716 emit_move_insn (tempreg, validize_mem (data->entry_parm));
2718 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2719 tempreg = convert_to_mode (data->nominal_mode, tempreg, unsignedp);
2721 if (GET_CODE (tempreg) == SUBREG
2722 && GET_MODE (tempreg) == data->nominal_mode
2723 && REG_P (SUBREG_REG (tempreg))
2724 && data->nominal_mode == data->passed_mode
2725 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (data->entry_parm)
2726 && GET_MODE_SIZE (GET_MODE (tempreg))
2727 < GET_MODE_SIZE (GET_MODE (data->entry_parm)))
2729 /* The argument is already sign/zero extended, so note it
2731 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
2732 SUBREG_PROMOTED_UNSIGNED_SET (tempreg, unsignedp);
2735 /* TREE_USED gets set erroneously during expand_assignment. */
2736 save_tree_used = TREE_USED (parm);
2737 expand_assignment (parm, make_tree (data->nominal_type, tempreg), false);
2738 TREE_USED (parm) = save_tree_used;
2739 all->first_conversion_insn = get_insns ();
2740 all->last_conversion_insn = get_last_insn ();
2743 did_conversion = true;
2746 emit_move_insn (parmreg, validize_mem (data->entry_parm));
2748 /* If we were passed a pointer but the actual value can safely live
2749 in a register, put it in one. */
2750 if (data->passed_pointer
2751 && TYPE_MODE (TREE_TYPE (parm)) != BLKmode
2752 /* If by-reference argument was promoted, demote it. */
2753 && (TYPE_MODE (TREE_TYPE (parm)) != GET_MODE (DECL_RTL (parm))
2754 || use_register_for_decl (parm)))
2756 /* We can't use nominal_mode, because it will have been set to
2757 Pmode above. We must use the actual mode of the parm. */
2758 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
2759 mark_user_reg (parmreg);
2761 if (GET_MODE (parmreg) != GET_MODE (DECL_RTL (parm)))
2763 rtx tempreg = gen_reg_rtx (GET_MODE (DECL_RTL (parm)));
2764 int unsigned_p = TYPE_UNSIGNED (TREE_TYPE (parm));
2766 push_to_sequence2 (all->first_conversion_insn,
2767 all->last_conversion_insn);
2768 emit_move_insn (tempreg, DECL_RTL (parm));
2769 tempreg = convert_to_mode (GET_MODE (parmreg), tempreg, unsigned_p);
2770 emit_move_insn (parmreg, tempreg);
2771 all->first_conversion_insn = get_insns ();
2772 all->last_conversion_insn = get_last_insn ();
2775 did_conversion = true;
2778 emit_move_insn (parmreg, DECL_RTL (parm));
2780 SET_DECL_RTL (parm, parmreg);
2782 /* STACK_PARM is the pointer, not the parm, and PARMREG is
2784 data->stack_parm = NULL;
2787 /* Mark the register as eliminable if we did no conversion and it was
2788 copied from memory at a fixed offset, and the arg pointer was not
2789 copied to a pseudo-reg. If the arg pointer is a pseudo reg or the
2790 offset formed an invalid address, such memory-equivalences as we
2791 make here would screw up life analysis for it. */
2792 if (data->nominal_mode == data->passed_mode
2794 && data->stack_parm != 0
2795 && MEM_P (data->stack_parm)
2796 && data->locate.offset.var == 0
2797 && reg_mentioned_p (virtual_incoming_args_rtx,
2798 XEXP (data->stack_parm, 0)))
2800 rtx linsn = get_last_insn ();
2803 /* Mark complex types separately. */
2804 if (GET_CODE (parmreg) == CONCAT)
2806 enum machine_mode submode
2807 = GET_MODE_INNER (GET_MODE (parmreg));
2808 int regnor = REGNO (XEXP (parmreg, 0));
2809 int regnoi = REGNO (XEXP (parmreg, 1));
2810 rtx stackr = adjust_address_nv (data->stack_parm, submode, 0);
2811 rtx stacki = adjust_address_nv (data->stack_parm, submode,
2812 GET_MODE_SIZE (submode));
2814 /* Scan backwards for the set of the real and
2816 for (sinsn = linsn; sinsn != 0;
2817 sinsn = prev_nonnote_insn (sinsn))
2819 set = single_set (sinsn);
2823 if (SET_DEST (set) == regno_reg_rtx [regnoi])
2824 set_unique_reg_note (sinsn, REG_EQUIV, stacki);
2825 else if (SET_DEST (set) == regno_reg_rtx [regnor])
2826 set_unique_reg_note (sinsn, REG_EQUIV, stackr);
2829 else if ((set = single_set (linsn)) != 0
2830 && SET_DEST (set) == parmreg)
2831 set_unique_reg_note (linsn, REG_EQUIV, data->stack_parm);
2834 /* For pointer data type, suggest pointer register. */
2835 if (POINTER_TYPE_P (TREE_TYPE (parm)))
2836 mark_reg_pointer (parmreg,
2837 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
2840 /* A subroutine of assign_parms. Allocate stack space to hold the current
2841 parameter. Get it there. Perform all ABI specified conversions. */
2844 assign_parm_setup_stack (struct assign_parm_data_all *all, tree parm,
2845 struct assign_parm_data_one *data)
2847 /* Value must be stored in the stack slot STACK_PARM during function
2849 bool to_conversion = false;
2851 assign_parm_remove_parallels (data);
2853 if (data->promoted_mode != data->nominal_mode)
2855 /* Conversion is required. */
2856 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
2858 emit_move_insn (tempreg, validize_mem (data->entry_parm));
2860 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2861 to_conversion = true;
2863 data->entry_parm = convert_to_mode (data->nominal_mode, tempreg,
2864 TYPE_UNSIGNED (TREE_TYPE (parm)));
2866 if (data->stack_parm)
2867 /* ??? This may need a big-endian conversion on sparc64. */
2869 = adjust_address (data->stack_parm, data->nominal_mode, 0);
2872 if (data->entry_parm != data->stack_parm)
2876 if (data->stack_parm == 0)
2879 = assign_stack_local (GET_MODE (data->entry_parm),
2880 GET_MODE_SIZE (GET_MODE (data->entry_parm)),
2881 TYPE_ALIGN (data->passed_type));
2882 set_mem_attributes (data->stack_parm, parm, 1);
2885 dest = validize_mem (data->stack_parm);
2886 src = validize_mem (data->entry_parm);
2890 /* Use a block move to handle potentially misaligned entry_parm. */
2892 push_to_sequence2 (all->first_conversion_insn,
2893 all->last_conversion_insn);
2894 to_conversion = true;
2896 emit_block_move (dest, src,
2897 GEN_INT (int_size_in_bytes (data->passed_type)),
2901 emit_move_insn (dest, src);
2906 all->first_conversion_insn = get_insns ();
2907 all->last_conversion_insn = get_last_insn ();
2911 SET_DECL_RTL (parm, data->stack_parm);
2914 /* A subroutine of assign_parms. If the ABI splits complex arguments, then
2915 undo the frobbing that we did in assign_parms_augmented_arg_list. */
2918 assign_parms_unsplit_complex (struct assign_parm_data_all *all, tree fnargs)
2921 tree orig_fnargs = all->orig_fnargs;
2923 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm))
2925 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
2926 && targetm.calls.split_complex_arg (TREE_TYPE (parm)))
2928 rtx tmp, real, imag;
2929 enum machine_mode inner = GET_MODE_INNER (DECL_MODE (parm));
2931 real = DECL_RTL (fnargs);
2932 imag = DECL_RTL (TREE_CHAIN (fnargs));
2933 if (inner != GET_MODE (real))
2935 real = gen_lowpart_SUBREG (inner, real);
2936 imag = gen_lowpart_SUBREG (inner, imag);
2939 if (TREE_ADDRESSABLE (parm))
2942 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (parm));
2944 /* split_complex_arg put the real and imag parts in
2945 pseudos. Move them to memory. */
2946 tmp = assign_stack_local (DECL_MODE (parm), size,
2947 TYPE_ALIGN (TREE_TYPE (parm)));
2948 set_mem_attributes (tmp, parm, 1);
2949 rmem = adjust_address_nv (tmp, inner, 0);
2950 imem = adjust_address_nv (tmp, inner, GET_MODE_SIZE (inner));
2951 push_to_sequence2 (all->first_conversion_insn,
2952 all->last_conversion_insn);
2953 emit_move_insn (rmem, real);
2954 emit_move_insn (imem, imag);
2955 all->first_conversion_insn = get_insns ();
2956 all->last_conversion_insn = get_last_insn ();
2960 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
2961 SET_DECL_RTL (parm, tmp);
2963 real = DECL_INCOMING_RTL (fnargs);
2964 imag = DECL_INCOMING_RTL (TREE_CHAIN (fnargs));
2965 if (inner != GET_MODE (real))
2967 real = gen_lowpart_SUBREG (inner, real);
2968 imag = gen_lowpart_SUBREG (inner, imag);
2970 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
2971 set_decl_incoming_rtl (parm, tmp, false);
2972 fnargs = TREE_CHAIN (fnargs);
2976 SET_DECL_RTL (parm, DECL_RTL (fnargs));
2977 set_decl_incoming_rtl (parm, DECL_INCOMING_RTL (fnargs), false);
2979 /* Set MEM_EXPR to the original decl, i.e. to PARM,
2980 instead of the copy of decl, i.e. FNARGS. */
2981 if (DECL_INCOMING_RTL (parm) && MEM_P (DECL_INCOMING_RTL (parm)))
2982 set_mem_expr (DECL_INCOMING_RTL (parm), parm);
2985 fnargs = TREE_CHAIN (fnargs);
2989 /* Assign RTL expressions to the function's parameters. This may involve
2990 copying them into registers and using those registers as the DECL_RTL. */
2993 assign_parms (tree fndecl)
2995 struct assign_parm_data_all all;
2998 crtl->args.internal_arg_pointer
2999 = targetm.calls.internal_arg_pointer ();
3001 assign_parms_initialize_all (&all);
3002 fnargs = assign_parms_augmented_arg_list (&all);
3004 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
3006 struct assign_parm_data_one data;
3008 /* Extract the type of PARM; adjust it according to ABI. */
3009 assign_parm_find_data_types (&all, parm, &data);
3011 /* Early out for errors and void parameters. */
3012 if (data.passed_mode == VOIDmode)
3014 SET_DECL_RTL (parm, const0_rtx);
3015 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
3019 /* Estimate stack alignment from parameter alignment. */
3020 if (SUPPORTS_STACK_ALIGNMENT)
3022 unsigned int align = FUNCTION_ARG_BOUNDARY (data.promoted_mode,
3024 if (TYPE_ALIGN (data.nominal_type) > align)
3025 align = TYPE_ALIGN (data.passed_type);
3026 if (crtl->stack_alignment_estimated < align)
3028 gcc_assert (!crtl->stack_realign_processed);
3029 crtl->stack_alignment_estimated = align;
3033 if (cfun->stdarg && !TREE_CHAIN (parm))
3034 assign_parms_setup_varargs (&all, &data, false);
3036 /* Find out where the parameter arrives in this function. */
3037 assign_parm_find_entry_rtl (&all, &data);
3039 /* Find out where stack space for this parameter might be. */
3040 if (assign_parm_is_stack_parm (&all, &data))
3042 assign_parm_find_stack_rtl (parm, &data);
3043 assign_parm_adjust_entry_rtl (&data);
3046 /* Record permanently how this parm was passed. */
3047 set_decl_incoming_rtl (parm, data.entry_parm, data.passed_pointer);
3049 /* Update info on where next arg arrives in registers. */
3050 FUNCTION_ARG_ADVANCE (all.args_so_far, data.promoted_mode,
3051 data.passed_type, data.named_arg);
3053 assign_parm_adjust_stack_rtl (&data);
3055 if (assign_parm_setup_block_p (&data))
3056 assign_parm_setup_block (&all, parm, &data);
3057 else if (data.passed_pointer || use_register_for_decl (parm))
3058 assign_parm_setup_reg (&all, parm, &data);
3060 assign_parm_setup_stack (&all, parm, &data);
3063 if (targetm.calls.split_complex_arg && fnargs != all.orig_fnargs)
3064 assign_parms_unsplit_complex (&all, fnargs);
3066 /* Output all parameter conversion instructions (possibly including calls)
3067 now that all parameters have been copied out of hard registers. */
3068 emit_insn (all.first_conversion_insn);
3070 /* Estimate reload stack alignment from scalar return mode. */
3071 if (SUPPORTS_STACK_ALIGNMENT)
3073 if (DECL_RESULT (fndecl))
3075 tree type = TREE_TYPE (DECL_RESULT (fndecl));
3076 enum machine_mode mode = TYPE_MODE (type);
3080 && !AGGREGATE_TYPE_P (type))
3082 unsigned int align = GET_MODE_ALIGNMENT (mode);
3083 if (crtl->stack_alignment_estimated < align)
3085 gcc_assert (!crtl->stack_realign_processed);
3086 crtl->stack_alignment_estimated = align;
3092 /* If we are receiving a struct value address as the first argument, set up
3093 the RTL for the function result. As this might require code to convert
3094 the transmitted address to Pmode, we do this here to ensure that possible
3095 preliminary conversions of the address have been emitted already. */
3096 if (all.function_result_decl)
3098 tree result = DECL_RESULT (current_function_decl);
3099 rtx addr = DECL_RTL (all.function_result_decl);
3102 if (DECL_BY_REFERENCE (result))
3106 addr = convert_memory_address (Pmode, addr);
3107 x = gen_rtx_MEM (DECL_MODE (result), addr);
3108 set_mem_attributes (x, result, 1);
3110 SET_DECL_RTL (result, x);
3113 /* We have aligned all the args, so add space for the pretend args. */
3114 crtl->args.pretend_args_size = all.pretend_args_size;
3115 all.stack_args_size.constant += all.extra_pretend_bytes;
3116 crtl->args.size = all.stack_args_size.constant;
3118 /* Adjust function incoming argument size for alignment and
3121 #ifdef REG_PARM_STACK_SPACE
3122 crtl->args.size = MAX (crtl->args.size,
3123 REG_PARM_STACK_SPACE (fndecl));
3126 crtl->args.size = CEIL_ROUND (crtl->args.size,
3127 PARM_BOUNDARY / BITS_PER_UNIT);
3129 #ifdef ARGS_GROW_DOWNWARD
3130 crtl->args.arg_offset_rtx
3131 = (all.stack_args_size.var == 0 ? GEN_INT (-all.stack_args_size.constant)
3132 : expand_expr (size_diffop (all.stack_args_size.var,
3133 size_int (-all.stack_args_size.constant)),
3134 NULL_RTX, VOIDmode, 0));
3136 crtl->args.arg_offset_rtx = ARGS_SIZE_RTX (all.stack_args_size);
3139 /* See how many bytes, if any, of its args a function should try to pop
3142 crtl->args.pops_args = RETURN_POPS_ARGS (fndecl, TREE_TYPE (fndecl),
3145 /* For stdarg.h function, save info about
3146 regs and stack space used by the named args. */
3148 crtl->args.info = all.args_so_far;
3150 /* Set the rtx used for the function return value. Put this in its
3151 own variable so any optimizers that need this information don't have
3152 to include tree.h. Do this here so it gets done when an inlined
3153 function gets output. */
3156 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
3157 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
3159 /* If scalar return value was computed in a pseudo-reg, or was a named
3160 return value that got dumped to the stack, copy that to the hard
3162 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
3164 tree decl_result = DECL_RESULT (fndecl);
3165 rtx decl_rtl = DECL_RTL (decl_result);
3167 if (REG_P (decl_rtl)
3168 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
3169 : DECL_REGISTER (decl_result))
3173 real_decl_rtl = targetm.calls.function_value (TREE_TYPE (decl_result),
3175 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
3176 /* The delay slot scheduler assumes that crtl->return_rtx
3177 holds the hard register containing the return value, not a
3178 temporary pseudo. */
3179 crtl->return_rtx = real_decl_rtl;
3184 /* A subroutine of gimplify_parameters, invoked via walk_tree.
3185 For all seen types, gimplify their sizes. */
3188 gimplify_parm_type (tree *tp, int *walk_subtrees, void *data)
3195 if (POINTER_TYPE_P (t))
3197 else if (TYPE_SIZE (t) && !TREE_CONSTANT (TYPE_SIZE (t))
3198 && !TYPE_SIZES_GIMPLIFIED (t))
3200 gimplify_type_sizes (t, (gimple_seq *) data);
3208 /* Gimplify the parameter list for current_function_decl. This involves
3209 evaluating SAVE_EXPRs of variable sized parameters and generating code
3210 to implement callee-copies reference parameters. Returns a sequence of
3211 statements to add to the beginning of the function. */
3214 gimplify_parameters (void)
3216 struct assign_parm_data_all all;
3218 gimple_seq stmts = NULL;
3220 assign_parms_initialize_all (&all);
3221 fnargs = assign_parms_augmented_arg_list (&all);
3223 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
3225 struct assign_parm_data_one data;
3227 /* Extract the type of PARM; adjust it according to ABI. */
3228 assign_parm_find_data_types (&all, parm, &data);
3230 /* Early out for errors and void parameters. */
3231 if (data.passed_mode == VOIDmode || DECL_SIZE (parm) == NULL)
3234 /* Update info on where next arg arrives in registers. */
3235 FUNCTION_ARG_ADVANCE (all.args_so_far, data.promoted_mode,
3236 data.passed_type, data.named_arg);
3238 /* ??? Once upon a time variable_size stuffed parameter list
3239 SAVE_EXPRs (amongst others) onto a pending sizes list. This
3240 turned out to be less than manageable in the gimple world.
3241 Now we have to hunt them down ourselves. */
3242 walk_tree_without_duplicates (&data.passed_type,
3243 gimplify_parm_type, &stmts);
3245 if (TREE_CODE (DECL_SIZE_UNIT (parm)) != INTEGER_CST)
3247 gimplify_one_sizepos (&DECL_SIZE (parm), &stmts);
3248 gimplify_one_sizepos (&DECL_SIZE_UNIT (parm), &stmts);
3251 if (data.passed_pointer)
3253 tree type = TREE_TYPE (data.passed_type);
3254 if (reference_callee_copied (&all.args_so_far, TYPE_MODE (type),
3255 type, data.named_arg))
3259 /* For constant-sized objects, this is trivial; for
3260 variable-sized objects, we have to play games. */
3261 if (TREE_CODE (DECL_SIZE_UNIT (parm)) == INTEGER_CST
3262 && !(flag_stack_check == GENERIC_STACK_CHECK
3263 && compare_tree_int (DECL_SIZE_UNIT (parm),
3264 STACK_CHECK_MAX_VAR_SIZE) > 0))
3266 local = create_tmp_var (type, get_name (parm));
3267 DECL_IGNORED_P (local) = 0;
3271 tree ptr_type, addr;
3273 ptr_type = build_pointer_type (type);
3274 addr = create_tmp_var (ptr_type, get_name (parm));
3275 DECL_IGNORED_P (addr) = 0;
3276 local = build_fold_indirect_ref (addr);
3278 t = built_in_decls[BUILT_IN_ALLOCA];
3279 t = build_call_expr (t, 1, DECL_SIZE_UNIT (parm));
3280 t = fold_convert (ptr_type, t);
3281 t = build2 (MODIFY_EXPR, TREE_TYPE (addr), addr, t);
3282 gimplify_and_add (t, &stmts);
3285 gimplify_assign (local, parm, &stmts);
3287 SET_DECL_VALUE_EXPR (parm, local);
3288 DECL_HAS_VALUE_EXPR_P (parm) = 1;
3296 /* Compute the size and offset from the start of the stacked arguments for a
3297 parm passed in mode PASSED_MODE and with type TYPE.
3299 INITIAL_OFFSET_PTR points to the current offset into the stacked
3302 The starting offset and size for this parm are returned in
3303 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
3304 nonzero, the offset is that of stack slot, which is returned in
3305 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
3306 padding required from the initial offset ptr to the stack slot.
3308 IN_REGS is nonzero if the argument will be passed in registers. It will
3309 never be set if REG_PARM_STACK_SPACE is not defined.
3311 FNDECL is the function in which the argument was defined.
3313 There are two types of rounding that are done. The first, controlled by
3314 FUNCTION_ARG_BOUNDARY, forces the offset from the start of the argument
3315 list to be aligned to the specific boundary (in bits). This rounding
3316 affects the initial and starting offsets, but not the argument size.
3318 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
3319 optionally rounds the size of the parm to PARM_BOUNDARY. The
3320 initial offset is not affected by this rounding, while the size always
3321 is and the starting offset may be. */
3323 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
3324 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
3325 callers pass in the total size of args so far as
3326 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
3329 locate_and_pad_parm (enum machine_mode passed_mode, tree type, int in_regs,
3330 int partial, tree fndecl ATTRIBUTE_UNUSED,
3331 struct args_size *initial_offset_ptr,
3332 struct locate_and_pad_arg_data *locate)
3335 enum direction where_pad;
3336 unsigned int boundary;
3337 int reg_parm_stack_space = 0;
3338 int part_size_in_regs;
3340 #ifdef REG_PARM_STACK_SPACE
3341 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
3343 /* If we have found a stack parm before we reach the end of the
3344 area reserved for registers, skip that area. */
3347 if (reg_parm_stack_space > 0)
3349 if (initial_offset_ptr->var)
3351 initial_offset_ptr->var
3352 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
3353 ssize_int (reg_parm_stack_space));
3354 initial_offset_ptr->constant = 0;
3356 else if (initial_offset_ptr->constant < reg_parm_stack_space)
3357 initial_offset_ptr->constant = reg_parm_stack_space;
3360 #endif /* REG_PARM_STACK_SPACE */
3362 part_size_in_regs = (reg_parm_stack_space == 0 ? partial : 0);
3365 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
3366 where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
3367 boundary = FUNCTION_ARG_BOUNDARY (passed_mode, type);
3368 locate->where_pad = where_pad;
3370 /* Alignment can't exceed MAX_SUPPORTED_STACK_ALIGNMENT. */
3371 if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
3372 boundary = MAX_SUPPORTED_STACK_ALIGNMENT;
3374 locate->boundary = boundary;
3376 if (SUPPORTS_STACK_ALIGNMENT)
3378 /* stack_alignment_estimated can't change after stack has been
3380 if (crtl->stack_alignment_estimated < boundary)
3382 if (!crtl->stack_realign_processed)
3383 crtl->stack_alignment_estimated = boundary;
3386 /* If stack is realigned and stack alignment value
3387 hasn't been finalized, it is OK not to increase
3388 stack_alignment_estimated. The bigger alignment
3389 requirement is recorded in stack_alignment_needed
3391 gcc_assert (!crtl->stack_realign_finalized
3392 && crtl->stack_realign_needed);
3397 /* Remember if the outgoing parameter requires extra alignment on the
3398 calling function side. */
3399 if (crtl->stack_alignment_needed < boundary)
3400 crtl->stack_alignment_needed = boundary;
3401 if (crtl->max_used_stack_slot_alignment < crtl->stack_alignment_needed)
3402 crtl->max_used_stack_slot_alignment = crtl->stack_alignment_needed;
3403 if (crtl->preferred_stack_boundary < boundary)
3404 crtl->preferred_stack_boundary = boundary;
3406 #ifdef ARGS_GROW_DOWNWARD
3407 locate->slot_offset.constant = -initial_offset_ptr->constant;
3408 if (initial_offset_ptr->var)
3409 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
3410 initial_offset_ptr->var);
3414 if (where_pad != none
3415 && (!host_integerp (sizetree, 1)
3416 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
3417 s2 = round_up (s2, PARM_BOUNDARY / BITS_PER_UNIT);
3418 SUB_PARM_SIZE (locate->slot_offset, s2);
3421 locate->slot_offset.constant += part_size_in_regs;
3424 #ifdef REG_PARM_STACK_SPACE
3425 || REG_PARM_STACK_SPACE (fndecl) > 0
3428 pad_to_arg_alignment (&locate->slot_offset, boundary,
3429 &locate->alignment_pad);
3431 locate->size.constant = (-initial_offset_ptr->constant
3432 - locate->slot_offset.constant);
3433 if (initial_offset_ptr->var)
3434 locate->size.var = size_binop (MINUS_EXPR,
3435 size_binop (MINUS_EXPR,
3437 initial_offset_ptr->var),
3438 locate->slot_offset.var);
3440 /* Pad_below needs the pre-rounded size to know how much to pad
3442 locate->offset = locate->slot_offset;
3443 if (where_pad == downward)
3444 pad_below (&locate->offset, passed_mode, sizetree);
3446 #else /* !ARGS_GROW_DOWNWARD */
3448 #ifdef REG_PARM_STACK_SPACE
3449 || REG_PARM_STACK_SPACE (fndecl) > 0
3452 pad_to_arg_alignment (initial_offset_ptr, boundary,
3453 &locate->alignment_pad);
3454 locate->slot_offset = *initial_offset_ptr;
3456 #ifdef PUSH_ROUNDING
3457 if (passed_mode != BLKmode)
3458 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
3461 /* Pad_below needs the pre-rounded size to know how much to pad below
3462 so this must be done before rounding up. */
3463 locate->offset = locate->slot_offset;
3464 if (where_pad == downward)
3465 pad_below (&locate->offset, passed_mode, sizetree);
3467 if (where_pad != none
3468 && (!host_integerp (sizetree, 1)
3469 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
3470 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3472 ADD_PARM_SIZE (locate->size, sizetree);
3474 locate->size.constant -= part_size_in_regs;
3475 #endif /* ARGS_GROW_DOWNWARD */
3478 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
3479 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
3482 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
3483 struct args_size *alignment_pad)
3485 tree save_var = NULL_TREE;
3486 HOST_WIDE_INT save_constant = 0;
3487 int boundary_in_bytes = boundary / BITS_PER_UNIT;
3488 HOST_WIDE_INT sp_offset = STACK_POINTER_OFFSET;
3490 #ifdef SPARC_STACK_BOUNDARY_HACK
3491 /* ??? The SPARC port may claim a STACK_BOUNDARY higher than
3492 the real alignment of %sp. However, when it does this, the
3493 alignment of %sp+STACK_POINTER_OFFSET is STACK_BOUNDARY. */
3494 if (SPARC_STACK_BOUNDARY_HACK)
3498 if (boundary > PARM_BOUNDARY)
3500 save_var = offset_ptr->var;
3501 save_constant = offset_ptr->constant;
3504 alignment_pad->var = NULL_TREE;
3505 alignment_pad->constant = 0;
3507 if (boundary > BITS_PER_UNIT)
3509 if (offset_ptr->var)
3511 tree sp_offset_tree = ssize_int (sp_offset);
3512 tree offset = size_binop (PLUS_EXPR,
3513 ARGS_SIZE_TREE (*offset_ptr),
3515 #ifdef ARGS_GROW_DOWNWARD
3516 tree rounded = round_down (offset, boundary / BITS_PER_UNIT);
3518 tree rounded = round_up (offset, boundary / BITS_PER_UNIT);
3521 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
3522 /* ARGS_SIZE_TREE includes constant term. */
3523 offset_ptr->constant = 0;
3524 if (boundary > PARM_BOUNDARY)
3525 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
3530 offset_ptr->constant = -sp_offset +
3531 #ifdef ARGS_GROW_DOWNWARD
3532 FLOOR_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
3534 CEIL_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
3536 if (boundary > PARM_BOUNDARY)
3537 alignment_pad->constant = offset_ptr->constant - save_constant;
3543 pad_below (struct args_size *offset_ptr, enum machine_mode passed_mode, tree sizetree)
3545 if (passed_mode != BLKmode)
3547 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
3548 offset_ptr->constant
3549 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
3550 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
3551 - GET_MODE_SIZE (passed_mode));
3555 if (TREE_CODE (sizetree) != INTEGER_CST
3556 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
3558 /* Round the size up to multiple of PARM_BOUNDARY bits. */
3559 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3561 ADD_PARM_SIZE (*offset_ptr, s2);
3562 SUB_PARM_SIZE (*offset_ptr, sizetree);
3568 /* True if register REGNO was alive at a place where `setjmp' was
3569 called and was set more than once or is an argument. Such regs may
3570 be clobbered by `longjmp'. */
3573 regno_clobbered_at_setjmp (bitmap setjmp_crosses, int regno)
3575 /* There appear to be cases where some local vars never reach the
3576 backend but have bogus regnos. */
3577 if (regno >= max_reg_num ())
3580 return ((REG_N_SETS (regno) > 1
3581 || REGNO_REG_SET_P (df_get_live_out (ENTRY_BLOCK_PTR), regno))
3582 && REGNO_REG_SET_P (setjmp_crosses, regno));
3585 /* Walk the tree of blocks describing the binding levels within a
3586 function and warn about variables the might be killed by setjmp or
3587 vfork. This is done after calling flow_analysis before register
3588 allocation since that will clobber the pseudo-regs to hard
3592 setjmp_vars_warning (bitmap setjmp_crosses, tree block)
3596 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
3598 if (TREE_CODE (decl) == VAR_DECL
3599 && DECL_RTL_SET_P (decl)
3600 && REG_P (DECL_RTL (decl))
3601 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
3602 warning (OPT_Wclobbered, "variable %q+D might be clobbered by"
3603 " %<longjmp%> or %<vfork%>", decl);
3606 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = BLOCK_CHAIN (sub))
3607 setjmp_vars_warning (setjmp_crosses, sub);
3610 /* Do the appropriate part of setjmp_vars_warning
3611 but for arguments instead of local variables. */
3614 setjmp_args_warning (bitmap setjmp_crosses)
3617 for (decl = DECL_ARGUMENTS (current_function_decl);
3618 decl; decl = TREE_CHAIN (decl))
3619 if (DECL_RTL (decl) != 0
3620 && REG_P (DECL_RTL (decl))
3621 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
3622 warning (OPT_Wclobbered,
3623 "argument %q+D might be clobbered by %<longjmp%> or %<vfork%>",
3627 /* Generate warning messages for variables live across setjmp. */
3630 generate_setjmp_warnings (void)
3632 bitmap setjmp_crosses = regstat_get_setjmp_crosses ();
3634 if (n_basic_blocks == NUM_FIXED_BLOCKS
3635 || bitmap_empty_p (setjmp_crosses))
3638 setjmp_vars_warning (setjmp_crosses, DECL_INITIAL (current_function_decl));
3639 setjmp_args_warning (setjmp_crosses);
3643 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
3644 and create duplicate blocks. */
3645 /* ??? Need an option to either create block fragments or to create
3646 abstract origin duplicates of a source block. It really depends
3647 on what optimization has been performed. */
3650 reorder_blocks (void)
3652 tree block = DECL_INITIAL (current_function_decl);
3653 VEC(tree,heap) *block_stack;
3655 if (block == NULL_TREE)
3658 block_stack = VEC_alloc (tree, heap, 10);
3660 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
3661 clear_block_marks (block);
3663 /* Prune the old trees away, so that they don't get in the way. */
3664 BLOCK_SUBBLOCKS (block) = NULL_TREE;
3665 BLOCK_CHAIN (block) = NULL_TREE;
3667 /* Recreate the block tree from the note nesting. */
3668 reorder_blocks_1 (get_insns (), block, &block_stack);
3669 BLOCK_SUBBLOCKS (block) = blocks_nreverse (BLOCK_SUBBLOCKS (block));
3671 VEC_free (tree, heap, block_stack);
3674 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
3677 clear_block_marks (tree block)
3681 TREE_ASM_WRITTEN (block) = 0;
3682 clear_block_marks (BLOCK_SUBBLOCKS (block));
3683 block = BLOCK_CHAIN (block);
3688 reorder_blocks_1 (rtx insns, tree current_block, VEC(tree,heap) **p_block_stack)
3692 for (insn = insns; insn; insn = NEXT_INSN (insn))
3696 if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_BEG)
3698 tree block = NOTE_BLOCK (insn);
3701 origin = (BLOCK_FRAGMENT_ORIGIN (block)
3702 ? BLOCK_FRAGMENT_ORIGIN (block)
3705 /* If we have seen this block before, that means it now
3706 spans multiple address regions. Create a new fragment. */
3707 if (TREE_ASM_WRITTEN (block))
3709 tree new_block = copy_node (block);
3711 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
3712 BLOCK_FRAGMENT_CHAIN (new_block)
3713 = BLOCK_FRAGMENT_CHAIN (origin);
3714 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
3716 NOTE_BLOCK (insn) = new_block;
3720 BLOCK_SUBBLOCKS (block) = 0;
3721 TREE_ASM_WRITTEN (block) = 1;
3722 /* When there's only one block for the entire function,
3723 current_block == block and we mustn't do this, it
3724 will cause infinite recursion. */
3725 if (block != current_block)
3727 if (block != origin)
3728 gcc_assert (BLOCK_SUPERCONTEXT (origin) == current_block);
3730 BLOCK_SUPERCONTEXT (block) = current_block;
3731 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
3732 BLOCK_SUBBLOCKS (current_block) = block;
3733 current_block = origin;
3735 VEC_safe_push (tree, heap, *p_block_stack, block);
3737 else if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_END)
3739 NOTE_BLOCK (insn) = VEC_pop (tree, *p_block_stack);
3740 BLOCK_SUBBLOCKS (current_block)
3741 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block));
3742 current_block = BLOCK_SUPERCONTEXT (current_block);
3748 /* Reverse the order of elements in the chain T of blocks,
3749 and return the new head of the chain (old last element). */
3752 blocks_nreverse (tree t)
3754 tree prev = 0, decl, next;
3755 for (decl = t; decl; decl = next)
3757 next = BLOCK_CHAIN (decl);
3758 BLOCK_CHAIN (decl) = prev;
3764 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
3765 non-NULL, list them all into VECTOR, in a depth-first preorder
3766 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
3770 all_blocks (tree block, tree *vector)
3776 TREE_ASM_WRITTEN (block) = 0;
3778 /* Record this block. */
3780 vector[n_blocks] = block;
3784 /* Record the subblocks, and their subblocks... */
3785 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
3786 vector ? vector + n_blocks : 0);
3787 block = BLOCK_CHAIN (block);
3793 /* Return a vector containing all the blocks rooted at BLOCK. The
3794 number of elements in the vector is stored in N_BLOCKS_P. The
3795 vector is dynamically allocated; it is the caller's responsibility
3796 to call `free' on the pointer returned. */
3799 get_block_vector (tree block, int *n_blocks_p)
3803 *n_blocks_p = all_blocks (block, NULL);
3804 block_vector = XNEWVEC (tree, *n_blocks_p);
3805 all_blocks (block, block_vector);
3807 return block_vector;
3810 static GTY(()) int next_block_index = 2;
3812 /* Set BLOCK_NUMBER for all the blocks in FN. */
3815 number_blocks (tree fn)
3821 /* For SDB and XCOFF debugging output, we start numbering the blocks
3822 from 1 within each function, rather than keeping a running
3824 #if defined (SDB_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
3825 if (write_symbols == SDB_DEBUG || write_symbols == XCOFF_DEBUG)
3826 next_block_index = 1;
3829 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
3831 /* The top-level BLOCK isn't numbered at all. */
3832 for (i = 1; i < n_blocks; ++i)
3833 /* We number the blocks from two. */
3834 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
3836 free (block_vector);
3841 /* If VAR is present in a subblock of BLOCK, return the subblock. */
3844 debug_find_var_in_block_tree (tree var, tree block)
3848 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
3852 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
3854 tree ret = debug_find_var_in_block_tree (var, t);
3862 /* Keep track of whether we're in a dummy function context. If we are,
3863 we don't want to invoke the set_current_function hook, because we'll
3864 get into trouble if the hook calls target_reinit () recursively or
3865 when the initial initialization is not yet complete. */
3867 static bool in_dummy_function;
3869 /* Invoke the target hook when setting cfun. Update the optimization options
3870 if the function uses different options than the default. */
3873 invoke_set_current_function_hook (tree fndecl)
3875 if (!in_dummy_function)
3877 tree opts = ((fndecl)
3878 ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (fndecl)
3879 : optimization_default_node);
3882 opts = optimization_default_node;
3884 /* Change optimization options if needed. */
3885 if (optimization_current_node != opts)
3887 optimization_current_node = opts;
3888 cl_optimization_restore (TREE_OPTIMIZATION (opts));
3891 targetm.set_current_function (fndecl);
3895 /* cfun should never be set directly; use this function. */
3898 set_cfun (struct function *new_cfun)
3900 if (cfun != new_cfun)
3903 invoke_set_current_function_hook (new_cfun ? new_cfun->decl : NULL_TREE);
3907 /* Keep track of the cfun stack. */
3909 typedef struct function *function_p;
3911 DEF_VEC_P(function_p);
3912 DEF_VEC_ALLOC_P(function_p,heap);
3914 /* Initialized with NOGC, making this poisonous to the garbage collector. */
3916 static VEC(function_p,heap) *cfun_stack;
3918 /* Push the current cfun onto the stack, and set cfun to new_cfun. */
3921 push_cfun (struct function *new_cfun)
3923 VEC_safe_push (function_p, heap, cfun_stack, cfun);
3924 set_cfun (new_cfun);
3927 /* Pop cfun from the stack. */
3932 struct function *new_cfun = VEC_pop (function_p, cfun_stack);
3933 set_cfun (new_cfun);
3936 /* Return value of funcdef and increase it. */
3938 get_next_funcdef_no (void)
3940 return funcdef_no++;
3943 /* Allocate a function structure for FNDECL and set its contents
3944 to the defaults. Set cfun to the newly-allocated object.
3945 Some of the helper functions invoked during initialization assume
3946 that cfun has already been set. Therefore, assign the new object
3947 directly into cfun and invoke the back end hook explicitly at the
3948 very end, rather than initializing a temporary and calling set_cfun
3951 ABSTRACT_P is true if this is a function that will never be seen by
3952 the middle-end. Such functions are front-end concepts (like C++
3953 function templates) that do not correspond directly to functions
3954 placed in object files. */
3957 allocate_struct_function (tree fndecl, bool abstract_p)
3960 tree fntype = fndecl ? TREE_TYPE (fndecl) : NULL_TREE;
3962 cfun = GGC_CNEW (struct function);
3964 cfun->function_frequency = FUNCTION_FREQUENCY_NORMAL;
3966 init_eh_for_function ();
3968 if (init_machine_status)
3969 cfun->machine = (*init_machine_status) ();
3971 #ifdef OVERRIDE_ABI_FORMAT
3972 OVERRIDE_ABI_FORMAT (fndecl);
3975 if (fndecl != NULL_TREE)
3977 DECL_STRUCT_FUNCTION (fndecl) = cfun;
3978 cfun->decl = fndecl;
3979 current_function_funcdef_no = get_next_funcdef_no ();
3981 result = DECL_RESULT (fndecl);
3982 if (!abstract_p && aggregate_value_p (result, fndecl))
3984 #ifdef PCC_STATIC_STRUCT_RETURN
3985 cfun->returns_pcc_struct = 1;
3987 cfun->returns_struct = 1;
3992 && TYPE_ARG_TYPES (fntype) != 0
3993 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
3994 != void_type_node));
3996 /* Assume all registers in stdarg functions need to be saved. */
3997 cfun->va_list_gpr_size = VA_LIST_MAX_GPR_SIZE;
3998 cfun->va_list_fpr_size = VA_LIST_MAX_FPR_SIZE;
4001 invoke_set_current_function_hook (fndecl);
4004 /* This is like allocate_struct_function, but pushes a new cfun for FNDECL
4005 instead of just setting it. */
4008 push_struct_function (tree fndecl)
4010 VEC_safe_push (function_p, heap, cfun_stack, cfun);
4011 allocate_struct_function (fndecl, false);
4014 /* Reset cfun, and other non-struct-function variables to defaults as
4015 appropriate for emitting rtl at the start of a function. */
4018 prepare_function_start (void)
4020 gcc_assert (!crtl->emit.x_last_insn);
4022 init_varasm_status ();
4024 default_rtl_profile ();
4026 cse_not_expected = ! optimize;
4028 /* Caller save not needed yet. */
4029 caller_save_needed = 0;
4031 /* We haven't done register allocation yet. */
4034 /* Indicate that we have not instantiated virtual registers yet. */
4035 virtuals_instantiated = 0;
4037 /* Indicate that we want CONCATs now. */
4038 generating_concat_p = 1;
4040 /* Indicate we have no need of a frame pointer yet. */
4041 frame_pointer_needed = 0;
4044 /* Initialize the rtl expansion mechanism so that we can do simple things
4045 like generate sequences. This is used to provide a context during global
4046 initialization of some passes. You must call expand_dummy_function_end
4047 to exit this context. */
4050 init_dummy_function_start (void)
4052 gcc_assert (!in_dummy_function);
4053 in_dummy_function = true;
4054 push_struct_function (NULL_TREE);
4055 prepare_function_start ();
4058 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
4059 and initialize static variables for generating RTL for the statements
4063 init_function_start (tree subr)
4065 if (subr && DECL_STRUCT_FUNCTION (subr))
4066 set_cfun (DECL_STRUCT_FUNCTION (subr));
4068 allocate_struct_function (subr, false);
4069 prepare_function_start ();
4071 /* Warn if this value is an aggregate type,
4072 regardless of which calling convention we are using for it. */
4073 if (AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
4074 warning (OPT_Waggregate_return, "function returns an aggregate");
4077 /* Make sure all values used by the optimization passes have sane
4080 init_function_for_compilation (void)
4084 /* No prologue/epilogue insns yet. Make sure that these vectors are
4086 gcc_assert (VEC_length (int, prologue) == 0);
4087 gcc_assert (VEC_length (int, epilogue) == 0);
4088 gcc_assert (VEC_length (int, sibcall_epilogue) == 0);
4092 struct rtl_opt_pass pass_init_function =
4098 init_function_for_compilation, /* execute */
4101 0, /* static_pass_number */
4103 0, /* properties_required */
4104 0, /* properties_provided */
4105 0, /* properties_destroyed */
4106 0, /* todo_flags_start */
4107 0 /* todo_flags_finish */
4113 expand_main_function (void)
4115 #if (defined(INVOKE__main) \
4116 || (!defined(HAS_INIT_SECTION) \
4117 && !defined(INIT_SECTION_ASM_OP) \
4118 && !defined(INIT_ARRAY_SECTION_ASM_OP)))
4119 emit_library_call (init_one_libfunc (NAME__MAIN), LCT_NORMAL, VOIDmode, 0);
4123 /* Expand code to initialize the stack_protect_guard. This is invoked at
4124 the beginning of a function to be protected. */
4126 #ifndef HAVE_stack_protect_set
4127 # define HAVE_stack_protect_set 0
4128 # define gen_stack_protect_set(x,y) (gcc_unreachable (), NULL_RTX)
4132 stack_protect_prologue (void)
4134 tree guard_decl = targetm.stack_protect_guard ();
4137 /* Avoid expand_expr here, because we don't want guard_decl pulled
4138 into registers unless absolutely necessary. And we know that
4139 crtl->stack_protect_guard is a local stack slot, so this skips
4141 x = validize_mem (DECL_RTL (crtl->stack_protect_guard));
4142 y = validize_mem (DECL_RTL (guard_decl));
4144 /* Allow the target to copy from Y to X without leaking Y into a
4146 if (HAVE_stack_protect_set)
4148 rtx insn = gen_stack_protect_set (x, y);
4156 /* Otherwise do a straight move. */
4157 emit_move_insn (x, y);
4160 /* Expand code to verify the stack_protect_guard. This is invoked at
4161 the end of a function to be protected. */
4163 #ifndef HAVE_stack_protect_test
4164 # define HAVE_stack_protect_test 0
4165 # define gen_stack_protect_test(x, y, z) (gcc_unreachable (), NULL_RTX)
4169 stack_protect_epilogue (void)
4171 tree guard_decl = targetm.stack_protect_guard ();
4172 rtx label = gen_label_rtx ();
4175 /* Avoid expand_expr here, because we don't want guard_decl pulled
4176 into registers unless absolutely necessary. And we know that
4177 crtl->stack_protect_guard is a local stack slot, so this skips
4179 x = validize_mem (DECL_RTL (crtl->stack_protect_guard));
4180 y = validize_mem (DECL_RTL (guard_decl));
4182 /* Allow the target to compare Y with X without leaking either into
4184 switch (HAVE_stack_protect_test != 0)
4187 tmp = gen_stack_protect_test (x, y, label);
4196 emit_cmp_and_jump_insns (x, y, EQ, NULL_RTX, ptr_mode, 1, label);
4200 /* The noreturn predictor has been moved to the tree level. The rtl-level
4201 predictors estimate this branch about 20%, which isn't enough to get
4202 things moved out of line. Since this is the only extant case of adding
4203 a noreturn function at the rtl level, it doesn't seem worth doing ought
4204 except adding the prediction by hand. */
4205 tmp = get_last_insn ();
4207 predict_insn_def (tmp, PRED_NORETURN, TAKEN);
4209 expand_expr_stmt (targetm.stack_protect_fail ());
4213 /* Start the RTL for a new function, and set variables used for
4215 SUBR is the FUNCTION_DECL node.
4216 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
4217 the function's parameters, which must be run at any return statement. */
4220 expand_function_start (tree subr)
4222 /* Make sure volatile mem refs aren't considered
4223 valid operands of arithmetic insns. */
4224 init_recog_no_volatile ();
4228 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
4231 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
4233 /* Make the label for return statements to jump to. Do not special
4234 case machines with special return instructions -- they will be
4235 handled later during jump, ifcvt, or epilogue creation. */
4236 return_label = gen_label_rtx ();
4238 /* Initialize rtx used to return the value. */
4239 /* Do this before assign_parms so that we copy the struct value address
4240 before any library calls that assign parms might generate. */
4242 /* Decide whether to return the value in memory or in a register. */
4243 if (aggregate_value_p (DECL_RESULT (subr), subr))
4245 /* Returning something that won't go in a register. */
4246 rtx value_address = 0;
4248 #ifdef PCC_STATIC_STRUCT_RETURN
4249 if (cfun->returns_pcc_struct)
4251 int size = int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr)));
4252 value_address = assemble_static_space (size);
4257 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 2);
4258 /* Expect to be passed the address of a place to store the value.
4259 If it is passed as an argument, assign_parms will take care of
4263 value_address = gen_reg_rtx (Pmode);
4264 emit_move_insn (value_address, sv);
4269 rtx x = value_address;
4270 if (!DECL_BY_REFERENCE (DECL_RESULT (subr)))
4272 x = gen_rtx_MEM (DECL_MODE (DECL_RESULT (subr)), x);
4273 set_mem_attributes (x, DECL_RESULT (subr), 1);
4275 SET_DECL_RTL (DECL_RESULT (subr), x);
4278 else if (DECL_MODE (DECL_RESULT (subr)) == VOIDmode)
4279 /* If return mode is void, this decl rtl should not be used. */
4280 SET_DECL_RTL (DECL_RESULT (subr), NULL_RTX);
4283 /* Compute the return values into a pseudo reg, which we will copy
4284 into the true return register after the cleanups are done. */
4285 tree return_type = TREE_TYPE (DECL_RESULT (subr));
4286 if (TYPE_MODE (return_type) != BLKmode
4287 && targetm.calls.return_in_msb (return_type))
4288 /* expand_function_end will insert the appropriate padding in
4289 this case. Use the return value's natural (unpadded) mode
4290 within the function proper. */
4291 SET_DECL_RTL (DECL_RESULT (subr),
4292 gen_reg_rtx (TYPE_MODE (return_type)));
4295 /* In order to figure out what mode to use for the pseudo, we
4296 figure out what the mode of the eventual return register will
4297 actually be, and use that. */
4298 rtx hard_reg = hard_function_value (return_type, subr, 0, 1);
4300 /* Structures that are returned in registers are not
4301 aggregate_value_p, so we may see a PARALLEL or a REG. */
4302 if (REG_P (hard_reg))
4303 SET_DECL_RTL (DECL_RESULT (subr),
4304 gen_reg_rtx (GET_MODE (hard_reg)));
4307 gcc_assert (GET_CODE (hard_reg) == PARALLEL);
4308 SET_DECL_RTL (DECL_RESULT (subr), gen_group_rtx (hard_reg));
4312 /* Set DECL_REGISTER flag so that expand_function_end will copy the
4313 result to the real return register(s). */
4314 DECL_REGISTER (DECL_RESULT (subr)) = 1;
4317 /* Initialize rtx for parameters and local variables.
4318 In some cases this requires emitting insns. */
4319 assign_parms (subr);
4321 /* If function gets a static chain arg, store it. */
4322 if (cfun->static_chain_decl)
4324 tree parm = cfun->static_chain_decl;
4325 rtx local = gen_reg_rtx (Pmode);
4327 set_decl_incoming_rtl (parm, static_chain_incoming_rtx, false);
4328 SET_DECL_RTL (parm, local);
4329 mark_reg_pointer (local, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
4331 emit_move_insn (local, static_chain_incoming_rtx);
4334 /* If the function receives a non-local goto, then store the
4335 bits we need to restore the frame pointer. */
4336 if (cfun->nonlocal_goto_save_area)
4341 /* ??? We need to do this save early. Unfortunately here is
4342 before the frame variable gets declared. Help out... */
4343 tree var = TREE_OPERAND (cfun->nonlocal_goto_save_area, 0);
4344 if (!DECL_RTL_SET_P (var))
4347 t_save = build4 (ARRAY_REF, ptr_type_node,
4348 cfun->nonlocal_goto_save_area,
4349 integer_zero_node, NULL_TREE, NULL_TREE);
4350 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
4351 r_save = convert_memory_address (Pmode, r_save);
4353 emit_move_insn (r_save, targetm.builtin_setjmp_frame_value ());
4354 update_nonlocal_goto_save_area ();
4357 /* The following was moved from init_function_start.
4358 The move is supposed to make sdb output more accurate. */
4359 /* Indicate the beginning of the function body,
4360 as opposed to parm setup. */
4361 emit_note (NOTE_INSN_FUNCTION_BEG);
4363 gcc_assert (NOTE_P (get_last_insn ()));
4365 parm_birth_insn = get_last_insn ();
4370 PROFILE_HOOK (current_function_funcdef_no);
4374 /* After the display initializations is where the stack checking
4376 if(flag_stack_check)
4377 stack_check_probe_note = emit_note (NOTE_INSN_DELETED);
4379 /* Make sure there is a line number after the function entry setup code. */
4380 force_next_line_note ();
4383 /* Undo the effects of init_dummy_function_start. */
4385 expand_dummy_function_end (void)
4387 gcc_assert (in_dummy_function);
4389 /* End any sequences that failed to be closed due to syntax errors. */
4390 while (in_sequence_p ())
4393 /* Outside function body, can't compute type's actual size
4394 until next function's body starts. */
4396 free_after_parsing (cfun);
4397 free_after_compilation (cfun);
4399 in_dummy_function = false;
4402 /* Call DOIT for each hard register used as a return value from
4403 the current function. */
4406 diddle_return_value (void (*doit) (rtx, void *), void *arg)
4408 rtx outgoing = crtl->return_rtx;
4413 if (REG_P (outgoing))
4414 (*doit) (outgoing, arg);
4415 else if (GET_CODE (outgoing) == PARALLEL)
4419 for (i = 0; i < XVECLEN (outgoing, 0); i++)
4421 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
4423 if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
4430 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
4436 clobber_return_register (void)
4438 diddle_return_value (do_clobber_return_reg, NULL);
4440 /* In case we do use pseudo to return value, clobber it too. */
4441 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
4443 tree decl_result = DECL_RESULT (current_function_decl);
4444 rtx decl_rtl = DECL_RTL (decl_result);
4445 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
4447 do_clobber_return_reg (decl_rtl, NULL);
4453 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
4459 use_return_register (void)
4461 diddle_return_value (do_use_return_reg, NULL);
4464 /* Possibly warn about unused parameters. */
4466 do_warn_unused_parameter (tree fn)
4470 for (decl = DECL_ARGUMENTS (fn);
4471 decl; decl = TREE_CHAIN (decl))
4472 if (!TREE_USED (decl) && TREE_CODE (decl) == PARM_DECL
4473 && DECL_NAME (decl) && !DECL_ARTIFICIAL (decl)
4474 && !TREE_NO_WARNING (decl))
4475 warning (OPT_Wunused_parameter, "unused parameter %q+D", decl);
4478 static GTY(()) rtx initial_trampoline;
4480 /* Generate RTL for the end of the current function. */
4483 expand_function_end (void)
4487 /* If arg_pointer_save_area was referenced only from a nested
4488 function, we will not have initialized it yet. Do that now. */
4489 if (arg_pointer_save_area && ! crtl->arg_pointer_save_area_init)
4490 get_arg_pointer_save_area ();
4492 /* If we are doing generic stack checking and this function makes calls,
4493 do a stack probe at the start of the function to ensure we have enough
4494 space for another stack frame. */
4495 if (flag_stack_check == GENERIC_STACK_CHECK)
4499 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
4503 probe_stack_range (STACK_OLD_CHECK_PROTECT,
4504 GEN_INT (STACK_CHECK_MAX_FRAME_SIZE));
4507 emit_insn_before (seq, stack_check_probe_note);
4512 /* End any sequences that failed to be closed due to syntax errors. */
4513 while (in_sequence_p ())
4516 clear_pending_stack_adjust ();
4517 do_pending_stack_adjust ();
4519 /* Output a linenumber for the end of the function.
4520 SDB depends on this. */
4521 force_next_line_note ();
4522 set_curr_insn_source_location (input_location);
4524 /* Before the return label (if any), clobber the return
4525 registers so that they are not propagated live to the rest of
4526 the function. This can only happen with functions that drop
4527 through; if there had been a return statement, there would
4528 have either been a return rtx, or a jump to the return label.
4530 We delay actual code generation after the current_function_value_rtx
4532 clobber_after = get_last_insn ();
4534 /* Output the label for the actual return from the function. */
4535 emit_label (return_label);
4537 if (USING_SJLJ_EXCEPTIONS)
4539 /* Let except.c know where it should emit the call to unregister
4540 the function context for sjlj exceptions. */
4541 if (flag_exceptions)
4542 sjlj_emit_function_exit_after (get_last_insn ());
4546 /* We want to ensure that instructions that may trap are not
4547 moved into the epilogue by scheduling, because we don't
4548 always emit unwind information for the epilogue. */
4549 if (flag_non_call_exceptions)
4550 emit_insn (gen_blockage ());
4553 /* If this is an implementation of throw, do what's necessary to
4554 communicate between __builtin_eh_return and the epilogue. */
4555 expand_eh_return ();
4557 /* If scalar return value was computed in a pseudo-reg, or was a named
4558 return value that got dumped to the stack, copy that to the hard
4560 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
4562 tree decl_result = DECL_RESULT (current_function_decl);
4563 rtx decl_rtl = DECL_RTL (decl_result);
4565 if (REG_P (decl_rtl)
4566 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
4567 : DECL_REGISTER (decl_result))
4569 rtx real_decl_rtl = crtl->return_rtx;
4571 /* This should be set in assign_parms. */
4572 gcc_assert (REG_FUNCTION_VALUE_P (real_decl_rtl));
4574 /* If this is a BLKmode structure being returned in registers,
4575 then use the mode computed in expand_return. Note that if
4576 decl_rtl is memory, then its mode may have been changed,
4577 but that crtl->return_rtx has not. */
4578 if (GET_MODE (real_decl_rtl) == BLKmode)
4579 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
4581 /* If a non-BLKmode return value should be padded at the least
4582 significant end of the register, shift it left by the appropriate
4583 amount. BLKmode results are handled using the group load/store
4585 if (TYPE_MODE (TREE_TYPE (decl_result)) != BLKmode
4586 && targetm.calls.return_in_msb (TREE_TYPE (decl_result)))
4588 emit_move_insn (gen_rtx_REG (GET_MODE (decl_rtl),
4589 REGNO (real_decl_rtl)),
4591 shift_return_value (GET_MODE (decl_rtl), true, real_decl_rtl);
4593 /* If a named return value dumped decl_return to memory, then
4594 we may need to re-do the PROMOTE_MODE signed/unsigned
4596 else if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
4598 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
4600 if (targetm.calls.promote_function_return (TREE_TYPE (current_function_decl)))
4601 promote_mode (TREE_TYPE (decl_result), GET_MODE (decl_rtl),
4604 convert_move (real_decl_rtl, decl_rtl, unsignedp);
4606 else if (GET_CODE (real_decl_rtl) == PARALLEL)
4608 /* If expand_function_start has created a PARALLEL for decl_rtl,
4609 move the result to the real return registers. Otherwise, do
4610 a group load from decl_rtl for a named return. */
4611 if (GET_CODE (decl_rtl) == PARALLEL)
4612 emit_group_move (real_decl_rtl, decl_rtl);
4614 emit_group_load (real_decl_rtl, decl_rtl,
4615 TREE_TYPE (decl_result),
4616 int_size_in_bytes (TREE_TYPE (decl_result)));
4618 /* In the case of complex integer modes smaller than a word, we'll
4619 need to generate some non-trivial bitfield insertions. Do that
4620 on a pseudo and not the hard register. */
4621 else if (GET_CODE (decl_rtl) == CONCAT
4622 && GET_MODE_CLASS (GET_MODE (decl_rtl)) == MODE_COMPLEX_INT
4623 && GET_MODE_BITSIZE (GET_MODE (decl_rtl)) <= BITS_PER_WORD)
4625 int old_generating_concat_p;
4628 old_generating_concat_p = generating_concat_p;
4629 generating_concat_p = 0;
4630 tmp = gen_reg_rtx (GET_MODE (decl_rtl));
4631 generating_concat_p = old_generating_concat_p;
4633 emit_move_insn (tmp, decl_rtl);
4634 emit_move_insn (real_decl_rtl, tmp);
4637 emit_move_insn (real_decl_rtl, decl_rtl);
4641 /* If returning a structure, arrange to return the address of the value
4642 in a place where debuggers expect to find it.
4644 If returning a structure PCC style,
4645 the caller also depends on this value.
4646 And cfun->returns_pcc_struct is not necessarily set. */
4647 if (cfun->returns_struct
4648 || cfun->returns_pcc_struct)
4650 rtx value_address = DECL_RTL (DECL_RESULT (current_function_decl));
4651 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
4654 if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
4655 type = TREE_TYPE (type);
4657 value_address = XEXP (value_address, 0);
4659 outgoing = targetm.calls.function_value (build_pointer_type (type),
4660 current_function_decl, true);
4662 /* Mark this as a function return value so integrate will delete the
4663 assignment and USE below when inlining this function. */
4664 REG_FUNCTION_VALUE_P (outgoing) = 1;
4666 /* The address may be ptr_mode and OUTGOING may be Pmode. */
4667 value_address = convert_memory_address (GET_MODE (outgoing),
4670 emit_move_insn (outgoing, value_address);
4672 /* Show return register used to hold result (in this case the address
4674 crtl->return_rtx = outgoing;
4677 /* Emit the actual code to clobber return register. */
4682 clobber_return_register ();
4683 expand_naked_return ();
4687 emit_insn_after (seq, clobber_after);
4690 /* Output the label for the naked return from the function. */
4691 emit_label (naked_return_label);
4693 /* @@@ This is a kludge. We want to ensure that instructions that
4694 may trap are not moved into the epilogue by scheduling, because
4695 we don't always emit unwind information for the epilogue. */
4696 if (! USING_SJLJ_EXCEPTIONS && flag_non_call_exceptions)
4697 emit_insn (gen_blockage ());
4699 /* If stack protection is enabled for this function, check the guard. */
4700 if (crtl->stack_protect_guard)
4701 stack_protect_epilogue ();
4703 /* If we had calls to alloca, and this machine needs
4704 an accurate stack pointer to exit the function,
4705 insert some code to save and restore the stack pointer. */
4706 if (! EXIT_IGNORE_STACK
4707 && cfun->calls_alloca)
4711 emit_stack_save (SAVE_FUNCTION, &tem, parm_birth_insn);
4712 emit_stack_restore (SAVE_FUNCTION, tem, NULL_RTX);
4715 /* ??? This should no longer be necessary since stupid is no longer with
4716 us, but there are some parts of the compiler (eg reload_combine, and
4717 sh mach_dep_reorg) that still try and compute their own lifetime info
4718 instead of using the general framework. */
4719 use_return_register ();
4723 get_arg_pointer_save_area (void)
4725 rtx ret = arg_pointer_save_area;
4729 ret = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
4730 arg_pointer_save_area = ret;
4733 if (! crtl->arg_pointer_save_area_init)
4737 /* Save the arg pointer at the beginning of the function. The
4738 generated stack slot may not be a valid memory address, so we
4739 have to check it and fix it if necessary. */
4741 emit_move_insn (validize_mem (ret),
4742 crtl->args.internal_arg_pointer);
4746 push_topmost_sequence ();
4747 emit_insn_after (seq, entry_of_function ());
4748 pop_topmost_sequence ();
4754 /* Extend a vector that records the INSN_UIDs of INSNS
4755 (a list of one or more insns). */
4758 record_insns (rtx insns, VEC(int,heap) **vecp)
4762 for (tmp = insns; tmp != NULL_RTX; tmp = NEXT_INSN (tmp))
4763 VEC_safe_push (int, heap, *vecp, INSN_UID (tmp));
4766 /* Set the locator of the insn chain starting at INSN to LOC. */
4768 set_insn_locators (rtx insn, int loc)
4770 while (insn != NULL_RTX)
4773 INSN_LOCATOR (insn) = loc;
4774 insn = NEXT_INSN (insn);
4778 /* Determine how many INSN_UIDs in VEC are part of INSN. Because we can
4779 be running after reorg, SEQUENCE rtl is possible. */
4782 contains (const_rtx insn, VEC(int,heap) **vec)
4786 if (NONJUMP_INSN_P (insn)
4787 && GET_CODE (PATTERN (insn)) == SEQUENCE)
4790 for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
4791 for (j = VEC_length (int, *vec) - 1; j >= 0; --j)
4792 if (INSN_UID (XVECEXP (PATTERN (insn), 0, i))
4793 == VEC_index (int, *vec, j))
4799 for (j = VEC_length (int, *vec) - 1; j >= 0; --j)
4800 if (INSN_UID (insn) == VEC_index (int, *vec, j))
4807 prologue_epilogue_contains (const_rtx insn)
4809 if (contains (insn, &prologue))
4811 if (contains (insn, &epilogue))
4817 sibcall_epilogue_contains (const_rtx insn)
4819 if (sibcall_epilogue)
4820 return contains (insn, &sibcall_epilogue);
4825 /* Insert gen_return at the end of block BB. This also means updating
4826 block_for_insn appropriately. */
4829 emit_return_into_block (basic_block bb)
4831 emit_jump_insn_after (gen_return (), BB_END (bb));
4833 #endif /* HAVE_return */
4835 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
4836 this into place with notes indicating where the prologue ends and where
4837 the epilogue begins. Update the basic block information when possible. */
4840 thread_prologue_and_epilogue_insns (void)
4844 #if defined (HAVE_sibcall_epilogue) || defined (HAVE_epilogue) || defined (HAVE_return) || defined (HAVE_prologue)
4847 #if defined (HAVE_epilogue) || defined(HAVE_return)
4848 rtx epilogue_end = NULL_RTX;
4852 rtl_profile_for_bb (ENTRY_BLOCK_PTR);
4853 #ifdef HAVE_prologue
4857 seq = gen_prologue ();
4860 /* Insert an explicit USE for the frame pointer
4861 if the profiling is on and the frame pointer is required. */
4862 if (crtl->profile && frame_pointer_needed)
4863 emit_use (hard_frame_pointer_rtx);
4865 /* Retain a map of the prologue insns. */
4866 record_insns (seq, &prologue);
4867 emit_note (NOTE_INSN_PROLOGUE_END);
4869 #ifndef PROFILE_BEFORE_PROLOGUE
4870 /* Ensure that instructions are not moved into the prologue when
4871 profiling is on. The call to the profiling routine can be
4872 emitted within the live range of a call-clobbered register. */
4874 emit_insn (gen_blockage ());
4879 set_insn_locators (seq, prologue_locator);
4881 /* Can't deal with multiple successors of the entry block
4882 at the moment. Function should always have at least one
4884 gcc_assert (single_succ_p (ENTRY_BLOCK_PTR));
4886 insert_insn_on_edge (seq, single_succ_edge (ENTRY_BLOCK_PTR));
4891 /* If the exit block has no non-fake predecessors, we don't need
4893 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
4894 if ((e->flags & EDGE_FAKE) == 0)
4899 rtl_profile_for_bb (EXIT_BLOCK_PTR);
4901 if (optimize && HAVE_return)
4903 /* If we're allowed to generate a simple return instruction,
4904 then by definition we don't need a full epilogue. Examine
4905 the block that falls through to EXIT. If it does not
4906 contain any code, examine its predecessors and try to
4907 emit (conditional) return instructions. */
4912 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
4913 if (e->flags & EDGE_FALLTHRU)
4919 /* Verify that there are no active instructions in the last block. */
4920 label = BB_END (last);
4921 while (label && !LABEL_P (label))
4923 if (active_insn_p (label))
4925 label = PREV_INSN (label);
4928 if (BB_HEAD (last) == label && LABEL_P (label))
4932 for (ei2 = ei_start (last->preds); (e = ei_safe_edge (ei2)); )
4934 basic_block bb = e->src;
4937 if (bb == ENTRY_BLOCK_PTR)
4944 if (!JUMP_P (jump) || JUMP_LABEL (jump) != label)
4950 /* If we have an unconditional jump, we can replace that
4951 with a simple return instruction. */
4952 if (simplejump_p (jump))
4954 emit_return_into_block (bb);
4958 /* If we have a conditional jump, we can try to replace
4959 that with a conditional return instruction. */
4960 else if (condjump_p (jump))
4962 if (! redirect_jump (jump, 0, 0))
4968 /* If this block has only one successor, it both jumps
4969 and falls through to the fallthru block, so we can't
4971 if (single_succ_p (bb))
4983 /* Fix up the CFG for the successful change we just made. */
4984 redirect_edge_succ (e, EXIT_BLOCK_PTR);
4987 /* Emit a return insn for the exit fallthru block. Whether
4988 this is still reachable will be determined later. */
4990 emit_barrier_after (BB_END (last));
4991 emit_return_into_block (last);
4992 epilogue_end = BB_END (last);
4993 single_succ_edge (last)->flags &= ~EDGE_FALLTHRU;
4998 /* Find the edge that falls through to EXIT. Other edges may exist
4999 due to RETURN instructions, but those don't need epilogues.
5000 There really shouldn't be a mixture -- either all should have
5001 been converted or none, however... */
5003 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5004 if (e->flags & EDGE_FALLTHRU)
5009 #ifdef HAVE_epilogue
5013 epilogue_end = emit_note (NOTE_INSN_EPILOGUE_BEG);
5014 seq = gen_epilogue ();
5015 emit_jump_insn (seq);
5017 /* Retain a map of the epilogue insns. */
5018 record_insns (seq, &epilogue);
5019 set_insn_locators (seq, epilogue_locator);
5024 insert_insn_on_edge (seq, e);
5032 if (! next_active_insn (BB_END (e->src)))
5034 /* We have a fall-through edge to the exit block, the source is not
5035 at the end of the function, and there will be an assembler epilogue
5036 at the end of the function.
5037 We can't use force_nonfallthru here, because that would try to
5038 use return. Inserting a jump 'by hand' is extremely messy, so
5039 we take advantage of cfg_layout_finalize using
5040 fixup_fallthru_exit_predecessor. */
5041 cfg_layout_initialize (0);
5042 FOR_EACH_BB (cur_bb)
5043 if (cur_bb->index >= NUM_FIXED_BLOCKS
5044 && cur_bb->next_bb->index >= NUM_FIXED_BLOCKS)
5045 cur_bb->aux = cur_bb->next_bb;
5046 cfg_layout_finalize ();
5049 default_rtl_profile ();
5053 commit_edge_insertions ();
5055 /* The epilogue insns we inserted may cause the exit edge to no longer
5057 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5059 if (((e->flags & EDGE_FALLTHRU) != 0)
5060 && returnjump_p (BB_END (e->src)))
5061 e->flags &= ~EDGE_FALLTHRU;
5065 #ifdef HAVE_sibcall_epilogue
5066 /* Emit sibling epilogues before any sibling call sites. */
5067 for (ei = ei_start (EXIT_BLOCK_PTR->preds); (e = ei_safe_edge (ei)); )
5069 basic_block bb = e->src;
5070 rtx insn = BB_END (bb);
5073 || ! SIBLING_CALL_P (insn))
5080 emit_insn (gen_sibcall_epilogue ());
5084 /* Retain a map of the epilogue insns. Used in life analysis to
5085 avoid getting rid of sibcall epilogue insns. Do this before we
5086 actually emit the sequence. */
5087 record_insns (seq, &sibcall_epilogue);
5088 set_insn_locators (seq, epilogue_locator);
5090 emit_insn_before (seq, insn);
5095 #ifdef HAVE_epilogue
5100 /* Similarly, move any line notes that appear after the epilogue.
5101 There is no need, however, to be quite so anal about the existence
5102 of such a note. Also possibly move
5103 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
5105 for (insn = epilogue_end; insn; insn = next)
5107 next = NEXT_INSN (insn);
5109 && (NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG))
5110 reorder_insns (insn, insn, PREV_INSN (epilogue_end));
5115 /* Threading the prologue and epilogue changes the artificial refs
5116 in the entry and exit blocks. */
5117 epilogue_completed = 1;
5118 df_update_entry_exit_and_calls ();
5121 /* Reposition the prologue-end and epilogue-begin notes after instruction
5122 scheduling and delayed branch scheduling. */
5125 reposition_prologue_and_epilogue_notes (void)
5127 #if defined (HAVE_prologue) || defined (HAVE_epilogue)
5128 rtx insn, last, note;
5131 if ((len = VEC_length (int, prologue)) > 0)
5135 /* Scan from the beginning until we reach the last prologue insn.
5136 We apparently can't depend on basic_block_{head,end} after
5138 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
5142 if (NOTE_KIND (insn) == NOTE_INSN_PROLOGUE_END)
5145 else if (contains (insn, &prologue))
5155 /* Find the prologue-end note if we haven't already, and
5156 move it to just after the last prologue insn. */
5159 for (note = last; (note = NEXT_INSN (note));)
5161 && NOTE_KIND (note) == NOTE_INSN_PROLOGUE_END)
5165 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
5167 last = NEXT_INSN (last);
5168 reorder_insns (note, note, last);
5172 if ((len = VEC_length (int, epilogue)) > 0)
5176 /* Scan from the end until we reach the first epilogue insn.
5177 We apparently can't depend on basic_block_{head,end} after
5179 for (insn = get_last_insn (); insn; insn = PREV_INSN (insn))
5183 if (NOTE_KIND (insn) == NOTE_INSN_EPILOGUE_BEG)
5186 else if (contains (insn, &epilogue))
5196 /* Find the epilogue-begin note if we haven't already, and
5197 move it to just before the first epilogue insn. */
5200 for (note = insn; (note = PREV_INSN (note));)
5202 && NOTE_KIND (note) == NOTE_INSN_EPILOGUE_BEG)
5206 if (PREV_INSN (last) != note)
5207 reorder_insns (note, note, PREV_INSN (last));
5210 #endif /* HAVE_prologue or HAVE_epilogue */
5213 /* Returns the name of the current function. */
5215 current_function_name (void)
5217 return lang_hooks.decl_printable_name (cfun->decl, 2);
5220 /* Returns the raw (mangled) name of the current function. */
5222 current_function_assembler_name (void)
5224 return IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (cfun->decl));
5229 rest_of_handle_check_leaf_regs (void)
5231 #ifdef LEAF_REGISTERS
5232 current_function_uses_only_leaf_regs
5233 = optimize > 0 && only_leaf_regs_used () && leaf_function_p ();
5238 /* Insert a TYPE into the used types hash table of CFUN. */
5240 used_types_insert_helper (tree type, struct function *func)
5242 if (type != NULL && func != NULL)
5246 if (func->used_types_hash == NULL)
5247 func->used_types_hash = htab_create_ggc (37, htab_hash_pointer,
5248 htab_eq_pointer, NULL);
5249 slot = htab_find_slot (func->used_types_hash, type, INSERT);
5255 /* Given a type, insert it into the used hash table in cfun. */
5257 used_types_insert (tree t)
5259 while (POINTER_TYPE_P (t) || TREE_CODE (t) == ARRAY_TYPE)
5261 t = TYPE_MAIN_VARIANT (t);
5262 if (debug_info_level > DINFO_LEVEL_NONE)
5263 used_types_insert_helper (t, cfun);
5266 struct rtl_opt_pass pass_leaf_regs =
5272 rest_of_handle_check_leaf_regs, /* execute */
5275 0, /* static_pass_number */
5277 0, /* properties_required */
5278 0, /* properties_provided */
5279 0, /* properties_destroyed */
5280 0, /* todo_flags_start */
5281 0 /* todo_flags_finish */
5286 rest_of_handle_thread_prologue_and_epilogue (void)
5289 cleanup_cfg (CLEANUP_EXPENSIVE);
5290 /* On some machines, the prologue and epilogue code, or parts thereof,
5291 can be represented as RTL. Doing so lets us schedule insns between
5292 it and the rest of the code and also allows delayed branch
5293 scheduling to operate in the epilogue. */
5295 thread_prologue_and_epilogue_insns ();
5299 struct rtl_opt_pass pass_thread_prologue_and_epilogue =
5303 "pro_and_epilogue", /* name */
5305 rest_of_handle_thread_prologue_and_epilogue, /* execute */
5308 0, /* static_pass_number */
5309 TV_THREAD_PROLOGUE_AND_EPILOGUE, /* tv_id */
5310 0, /* properties_required */
5311 0, /* properties_provided */
5312 0, /* properties_destroyed */
5313 TODO_verify_flow, /* todo_flags_start */
5316 TODO_df_finish | TODO_verify_rtl_sharing |
5317 TODO_ggc_collect /* todo_flags_finish */
5322 /* This mini-pass fixes fall-out from SSA in asm statements that have
5323 in-out constraints. Say you start with
5326 asm ("": "+mr" (inout));
5329 which is transformed very early to use explicit output and match operands:
5332 asm ("": "=mr" (inout) : "0" (inout));
5335 Or, after SSA and copyprop,
5337 asm ("": "=mr" (inout_2) : "0" (inout_1));
5340 Clearly inout_2 and inout_1 can't be coalesced easily anymore, as
5341 they represent two separate values, so they will get different pseudo
5342 registers during expansion. Then, since the two operands need to match
5343 per the constraints, but use different pseudo registers, reload can
5344 only register a reload for these operands. But reloads can only be
5345 satisfied by hardregs, not by memory, so we need a register for this
5346 reload, just because we are presented with non-matching operands.
5347 So, even though we allow memory for this operand, no memory can be
5348 used for it, just because the two operands don't match. This can
5349 cause reload failures on register-starved targets.
5351 So it's a symptom of reload not being able to use memory for reloads
5352 or, alternatively it's also a symptom of both operands not coming into
5353 reload as matching (in which case the pseudo could go to memory just
5354 fine, as the alternative allows it, and no reload would be necessary).
5355 We fix the latter problem here, by transforming
5357 asm ("": "=mr" (inout_2) : "0" (inout_1));
5362 asm ("": "=mr" (inout_2) : "0" (inout_2)); */
5365 match_asm_constraints_1 (rtx insn, rtx *p_sets, int noutputs)
5368 bool changed = false;
5369 rtx op = SET_SRC (p_sets[0]);
5370 int ninputs = ASM_OPERANDS_INPUT_LENGTH (op);
5371 rtvec inputs = ASM_OPERANDS_INPUT_VEC (op);
5372 bool *output_matched = XALLOCAVEC (bool, noutputs);
5374 memset (output_matched, 0, noutputs * sizeof (bool));
5375 for (i = 0; i < ninputs; i++)
5377 rtx input, output, insns;
5378 const char *constraint = ASM_OPERANDS_INPUT_CONSTRAINT (op, i);
5382 match = strtoul (constraint, &end, 10);
5383 if (end == constraint)
5386 gcc_assert (match < noutputs);
5387 output = SET_DEST (p_sets[match]);
5388 input = RTVEC_ELT (inputs, i);
5389 /* Only do the transformation for pseudos. */
5390 if (! REG_P (output)
5391 || rtx_equal_p (output, input)
5392 || (GET_MODE (input) != VOIDmode
5393 && GET_MODE (input) != GET_MODE (output)))
5396 /* We can't do anything if the output is also used as input,
5397 as we're going to overwrite it. */
5398 for (j = 0; j < ninputs; j++)
5399 if (reg_overlap_mentioned_p (output, RTVEC_ELT (inputs, j)))
5404 /* Avoid changing the same input several times. For
5405 asm ("" : "=mr" (out1), "=mr" (out2) : "0" (in), "1" (in));
5406 only change in once (to out1), rather than changing it
5407 first to out1 and afterwards to out2. */
5410 for (j = 0; j < noutputs; j++)
5411 if (output_matched[j] && input == SET_DEST (p_sets[j]))
5416 output_matched[match] = true;
5419 emit_move_insn (output, input);
5420 insns = get_insns ();
5422 emit_insn_before (insns, insn);
5424 /* Now replace all mentions of the input with output. We can't
5425 just replace the occurrence in inputs[i], as the register might
5426 also be used in some other input (or even in an address of an
5427 output), which would mean possibly increasing the number of
5428 inputs by one (namely 'output' in addition), which might pose
5429 a too complicated problem for reload to solve. E.g. this situation:
5431 asm ("" : "=r" (output), "=m" (input) : "0" (input))
5433 Here 'input' is used in two occurrences as input (once for the
5434 input operand, once for the address in the second output operand).
5435 If we would replace only the occurrence of the input operand (to
5436 make the matching) we would be left with this:
5439 asm ("" : "=r" (output), "=m" (input) : "0" (output))
5441 Now we suddenly have two different input values (containing the same
5442 value, but different pseudos) where we formerly had only one.
5443 With more complicated asms this might lead to reload failures
5444 which wouldn't have happen without this pass. So, iterate over
5445 all operands and replace all occurrences of the register used. */
5446 for (j = 0; j < noutputs; j++)
5447 if (!rtx_equal_p (SET_DEST (p_sets[j]), input)
5448 && reg_overlap_mentioned_p (input, SET_DEST (p_sets[j])))
5449 SET_DEST (p_sets[j]) = replace_rtx (SET_DEST (p_sets[j]),
5451 for (j = 0; j < ninputs; j++)
5452 if (reg_overlap_mentioned_p (input, RTVEC_ELT (inputs, j)))
5453 RTVEC_ELT (inputs, j) = replace_rtx (RTVEC_ELT (inputs, j),
5460 df_insn_rescan (insn);
5464 rest_of_match_asm_constraints (void)
5467 rtx insn, pat, *p_sets;
5470 if (!crtl->has_asm_statement)
5473 df_set_flags (DF_DEFER_INSN_RESCAN);
5476 FOR_BB_INSNS (bb, insn)
5481 pat = PATTERN (insn);
5482 if (GET_CODE (pat) == PARALLEL)
5483 p_sets = &XVECEXP (pat, 0, 0), noutputs = XVECLEN (pat, 0);
5484 else if (GET_CODE (pat) == SET)
5485 p_sets = &PATTERN (insn), noutputs = 1;
5489 if (GET_CODE (*p_sets) == SET
5490 && GET_CODE (SET_SRC (*p_sets)) == ASM_OPERANDS)
5491 match_asm_constraints_1 (insn, p_sets, noutputs);
5495 return TODO_df_finish;
5498 struct rtl_opt_pass pass_match_asm_constraints =
5502 "asmcons", /* name */
5504 rest_of_match_asm_constraints, /* execute */
5507 0, /* static_pass_number */
5509 0, /* properties_required */
5510 0, /* properties_provided */
5511 0, /* properties_destroyed */
5512 0, /* todo_flags_start */
5513 TODO_dump_func /* todo_flags_finish */
5518 #include "gt-function.h"