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"
62 #include "tree-gimple.h"
63 #include "tree-pass.h"
69 /* So we can assign to cfun in this file. */
72 #ifndef LOCAL_ALIGNMENT
73 #define LOCAL_ALIGNMENT(TYPE, ALIGNMENT) ALIGNMENT
76 #ifndef STACK_ALIGNMENT_NEEDED
77 #define STACK_ALIGNMENT_NEEDED 1
80 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
82 /* Some systems use __main in a way incompatible with its use in gcc, in these
83 cases use the macros NAME__MAIN to give a quoted symbol and SYMBOL__MAIN to
84 give the same symbol without quotes for an alternative entry point. You
85 must define both, or neither. */
87 #define NAME__MAIN "__main"
90 /* Round a value to the lowest integer less than it that is a multiple of
91 the required alignment. Avoid using division in case the value is
92 negative. Assume the alignment is a power of two. */
93 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
95 /* Similar, but round to the next highest integer that meets the
97 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
99 /* Nonzero if function being compiled doesn't contain any calls
100 (ignoring the prologue and epilogue). This is set prior to
101 local register allocation and is valid for the remaining
103 int current_function_is_leaf;
105 /* Nonzero if function being compiled doesn't modify the stack pointer
106 (ignoring the prologue and epilogue). This is only valid after
107 pass_stack_ptr_mod has run. */
108 int current_function_sp_is_unchanging;
110 /* Nonzero if the function being compiled is a leaf function which only
111 uses leaf registers. This is valid after reload (specifically after
112 sched2) and is useful only if the port defines LEAF_REGISTERS. */
113 int current_function_uses_only_leaf_regs;
115 /* Nonzero once virtual register instantiation has been done.
116 assign_stack_local uses frame_pointer_rtx when this is nonzero.
117 calls.c:emit_library_call_value_1 uses it to set up
118 post-instantiation libcalls. */
119 int virtuals_instantiated;
121 /* Assign unique numbers to labels generated for profiling, debugging, etc. */
122 static GTY(()) int funcdef_no;
124 /* These variables hold pointers to functions to create and destroy
125 target specific, per-function data structures. */
126 struct machine_function * (*init_machine_status) (void);
128 /* The currently compiled function. */
129 struct function *cfun = 0;
131 /* These arrays record the INSN_UIDs of the prologue and epilogue insns. */
132 static VEC(int,heap) *prologue;
133 static VEC(int,heap) *epilogue;
135 /* Array of INSN_UIDs to hold the INSN_UIDs for each sibcall epilogue
137 static VEC(int,heap) *sibcall_epilogue;
139 /* In order to evaluate some expressions, such as function calls returning
140 structures in memory, we need to temporarily allocate stack locations.
141 We record each allocated temporary in the following structure.
143 Associated with each temporary slot is a nesting level. When we pop up
144 one level, all temporaries associated with the previous level are freed.
145 Normally, all temporaries are freed after the execution of the statement
146 in which they were created. However, if we are inside a ({...}) grouping,
147 the result may be in a temporary and hence must be preserved. If the
148 result could be in a temporary, we preserve it if we can determine which
149 one it is in. If we cannot determine which temporary may contain the
150 result, all temporaries are preserved. A temporary is preserved by
151 pretending it was allocated at the previous nesting level.
153 Automatic variables are also assigned temporary slots, at the nesting
154 level where they are defined. They are marked a "kept" so that
155 free_temp_slots will not free them. */
157 struct temp_slot GTY(())
159 /* Points to next temporary slot. */
160 struct temp_slot *next;
161 /* Points to previous temporary slot. */
162 struct temp_slot *prev;
164 /* The rtx to used to reference the slot. */
166 /* The rtx used to represent the address if not the address of the
167 slot above. May be an EXPR_LIST if multiple addresses exist. */
169 /* The alignment (in bits) of the slot. */
171 /* The size, in units, of the slot. */
173 /* The type of the object in the slot, or zero if it doesn't correspond
174 to a type. We use this to determine whether a slot can be reused.
175 It can be reused if objects of the type of the new slot will always
176 conflict with objects of the type of the old slot. */
178 /* Nonzero if this temporary is currently in use. */
180 /* Nonzero if this temporary has its address taken. */
182 /* Nesting level at which this slot is being used. */
184 /* Nonzero if this should survive a call to free_temp_slots. */
186 /* The offset of the slot from the frame_pointer, including extra space
187 for alignment. This info is for combine_temp_slots. */
188 HOST_WIDE_INT base_offset;
189 /* The size of the slot, including extra space for alignment. This
190 info is for combine_temp_slots. */
191 HOST_WIDE_INT full_size;
194 /* Forward declarations. */
196 static struct temp_slot *find_temp_slot_from_address (rtx);
197 static void pad_to_arg_alignment (struct args_size *, int, struct args_size *);
198 static void pad_below (struct args_size *, enum machine_mode, tree);
199 static void reorder_blocks_1 (rtx, tree, VEC(tree,heap) **);
200 static int all_blocks (tree, tree *);
201 static tree *get_block_vector (tree, int *);
202 extern tree debug_find_var_in_block_tree (tree, tree);
203 /* We always define `record_insns' even if it's not used so that we
204 can always export `prologue_epilogue_contains'. */
205 static void record_insns (rtx, VEC(int,heap) **) ATTRIBUTE_UNUSED;
206 static int contains (const_rtx, VEC(int,heap) **);
208 static void emit_return_into_block (basic_block);
210 #if defined(HAVE_epilogue) && defined(INCOMING_RETURN_ADDR_RTX)
211 static rtx keep_stack_depressed (rtx);
213 static void prepare_function_start (void);
214 static void do_clobber_return_reg (rtx, void *);
215 static void do_use_return_reg (rtx, void *);
216 static void set_insn_locators (rtx, int) ATTRIBUTE_UNUSED;
218 /* Pointer to chain of `struct function' for containing functions. */
219 struct function *outer_function_chain;
221 /* Given a function decl for a containing function,
222 return the `struct function' for it. */
225 find_function_data (tree decl)
229 for (p = outer_function_chain; p; p = p->outer)
236 /* Save the current context for compilation of a nested function.
237 This is called from language-specific code. The caller should use
238 the enter_nested langhook to save any language-specific state,
239 since this function knows only about language-independent
243 push_function_context_to (tree context ATTRIBUTE_UNUSED)
248 allocate_struct_function (NULL, false);
251 p->outer = outer_function_chain;
252 outer_function_chain = p;
254 lang_hooks.function.enter_nested (p);
260 push_function_context (void)
262 push_function_context_to (current_function_decl);
265 /* Restore the last saved context, at the end of a nested function.
266 This function is called from language-specific code. */
269 pop_function_context_from (tree context ATTRIBUTE_UNUSED)
271 struct function *p = outer_function_chain;
274 outer_function_chain = p->outer;
276 current_function_decl = p->decl;
278 lang_hooks.function.leave_nested (p);
280 /* Reset variables that have known state during rtx generation. */
281 virtuals_instantiated = 0;
282 generating_concat_p = 1;
286 pop_function_context (void)
288 pop_function_context_from (current_function_decl);
291 /* Clear out all parts of the state in F that can safely be discarded
292 after the function has been parsed, but not compiled, to let
293 garbage collection reclaim the memory. */
296 free_after_parsing (struct function *f)
298 /* f->expr->forced_labels is used by code generation. */
299 /* f->emit->regno_reg_rtx is used by code generation. */
300 /* f->varasm is used by code generation. */
301 /* f->eh->eh_return_stub_label is used by code generation. */
303 lang_hooks.function.final (f);
306 /* Clear out all parts of the state in F that can safely be discarded
307 after the function has been compiled, to let garbage collection
308 reclaim the memory. */
311 free_after_compilation (struct function *f)
313 VEC_free (int, heap, prologue);
314 VEC_free (int, heap, epilogue);
315 VEC_free (int, heap, sibcall_epilogue);
316 if (rtl.emit.regno_pointer_align)
317 free (rtl.emit.regno_pointer_align);
319 memset (&rtl, 0, sizeof (rtl));
324 f->arg_offset_rtx = NULL;
325 f->return_rtx = NULL;
326 f->internal_arg_pointer = NULL;
327 f->epilogue_delay_list = NULL;
330 /* Return size needed for stack frame based on slots so far allocated.
331 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
332 the caller may have to do that. */
335 get_frame_size (void)
337 if (FRAME_GROWS_DOWNWARD)
338 return -frame_offset;
343 /* Issue an error message and return TRUE if frame OFFSET overflows in
344 the signed target pointer arithmetics for function FUNC. Otherwise
348 frame_offset_overflow (HOST_WIDE_INT offset, tree func)
350 unsigned HOST_WIDE_INT size = FRAME_GROWS_DOWNWARD ? -offset : offset;
352 if (size > ((unsigned HOST_WIDE_INT) 1 << (GET_MODE_BITSIZE (Pmode) - 1))
353 /* Leave room for the fixed part of the frame. */
354 - 64 * UNITS_PER_WORD)
356 error ("%Jtotal size of local objects too large", func);
363 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
364 with machine mode MODE.
366 ALIGN controls the amount of alignment for the address of the slot:
367 0 means according to MODE,
368 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
369 -2 means use BITS_PER_UNIT,
370 positive specifies alignment boundary in bits.
372 We do not round to stack_boundary here. */
375 assign_stack_local (enum machine_mode mode, HOST_WIDE_INT size, int align)
378 int bigend_correction = 0;
379 unsigned int alignment;
380 int frame_off, frame_alignment, frame_phase;
387 alignment = BIGGEST_ALIGNMENT;
389 alignment = GET_MODE_ALIGNMENT (mode);
391 /* Allow the target to (possibly) increase the alignment of this
393 type = lang_hooks.types.type_for_mode (mode, 0);
395 alignment = LOCAL_ALIGNMENT (type, alignment);
397 alignment /= BITS_PER_UNIT;
399 else if (align == -1)
401 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
402 size = CEIL_ROUND (size, alignment);
404 else if (align == -2)
405 alignment = 1; /* BITS_PER_UNIT / BITS_PER_UNIT */
407 alignment = align / BITS_PER_UNIT;
409 if (FRAME_GROWS_DOWNWARD)
410 frame_offset -= size;
412 /* Ignore alignment we can't do with expected alignment of the boundary. */
413 if (alignment * BITS_PER_UNIT > PREFERRED_STACK_BOUNDARY)
414 alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
416 if (cfun->stack_alignment_needed < alignment * BITS_PER_UNIT)
417 cfun->stack_alignment_needed = alignment * BITS_PER_UNIT;
419 /* Calculate how many bytes the start of local variables is off from
421 frame_alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
422 frame_off = STARTING_FRAME_OFFSET % frame_alignment;
423 frame_phase = frame_off ? frame_alignment - frame_off : 0;
425 /* Round the frame offset to the specified alignment. The default is
426 to always honor requests to align the stack but a port may choose to
427 do its own stack alignment by defining STACK_ALIGNMENT_NEEDED. */
428 if (STACK_ALIGNMENT_NEEDED
432 /* We must be careful here, since FRAME_OFFSET might be negative and
433 division with a negative dividend isn't as well defined as we might
434 like. So we instead assume that ALIGNMENT is a power of two and
435 use logical operations which are unambiguous. */
436 if (FRAME_GROWS_DOWNWARD)
438 = (FLOOR_ROUND (frame_offset - frame_phase,
439 (unsigned HOST_WIDE_INT) alignment)
443 = (CEIL_ROUND (frame_offset - frame_phase,
444 (unsigned HOST_WIDE_INT) alignment)
448 /* On a big-endian machine, if we are allocating more space than we will use,
449 use the least significant bytes of those that are allocated. */
450 if (BYTES_BIG_ENDIAN && mode != BLKmode && GET_MODE_SIZE (mode) < size)
451 bigend_correction = size - GET_MODE_SIZE (mode);
453 /* If we have already instantiated virtual registers, return the actual
454 address relative to the frame pointer. */
455 if (virtuals_instantiated)
456 addr = plus_constant (frame_pointer_rtx,
458 (frame_offset + bigend_correction
459 + STARTING_FRAME_OFFSET, Pmode));
461 addr = plus_constant (virtual_stack_vars_rtx,
463 (frame_offset + bigend_correction,
466 if (!FRAME_GROWS_DOWNWARD)
467 frame_offset += size;
469 x = gen_rtx_MEM (mode, addr);
470 MEM_NOTRAP_P (x) = 1;
473 = gen_rtx_EXPR_LIST (VOIDmode, x, stack_slot_list);
475 if (frame_offset_overflow (frame_offset, current_function_decl))
481 /* Removes temporary slot TEMP from LIST. */
484 cut_slot_from_list (struct temp_slot *temp, struct temp_slot **list)
487 temp->next->prev = temp->prev;
489 temp->prev->next = temp->next;
493 temp->prev = temp->next = NULL;
496 /* Inserts temporary slot TEMP to LIST. */
499 insert_slot_to_list (struct temp_slot *temp, struct temp_slot **list)
503 (*list)->prev = temp;
508 /* Returns the list of used temp slots at LEVEL. */
510 static struct temp_slot **
511 temp_slots_at_level (int level)
513 if (level >= (int) VEC_length (temp_slot_p, used_temp_slots))
514 VEC_safe_grow_cleared (temp_slot_p, gc, used_temp_slots, level + 1);
516 return &(VEC_address (temp_slot_p, used_temp_slots)[level]);
519 /* Returns the maximal temporary slot level. */
522 max_slot_level (void)
524 if (!used_temp_slots)
527 return VEC_length (temp_slot_p, used_temp_slots) - 1;
530 /* Moves temporary slot TEMP to LEVEL. */
533 move_slot_to_level (struct temp_slot *temp, int level)
535 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
536 insert_slot_to_list (temp, temp_slots_at_level (level));
540 /* Make temporary slot TEMP available. */
543 make_slot_available (struct temp_slot *temp)
545 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
546 insert_slot_to_list (temp, &avail_temp_slots);
551 /* Allocate a temporary stack slot and record it for possible later
554 MODE is the machine mode to be given to the returned rtx.
556 SIZE is the size in units of the space required. We do no rounding here
557 since assign_stack_local will do any required rounding.
559 KEEP is 1 if this slot is to be retained after a call to
560 free_temp_slots. Automatic variables for a block are allocated
561 with this flag. KEEP values of 2 or 3 were needed respectively
562 for variables whose lifetime is controlled by CLEANUP_POINT_EXPRs
563 or for SAVE_EXPRs, but they are now unused.
565 TYPE is the type that will be used for the stack slot. */
568 assign_stack_temp_for_type (enum machine_mode mode, HOST_WIDE_INT size,
572 struct temp_slot *p, *best_p = 0, *selected = NULL, **pp;
575 /* If SIZE is -1 it means that somebody tried to allocate a temporary
576 of a variable size. */
577 gcc_assert (size != -1);
579 /* These are now unused. */
580 gcc_assert (keep <= 1);
583 align = BIGGEST_ALIGNMENT;
585 align = GET_MODE_ALIGNMENT (mode);
588 type = lang_hooks.types.type_for_mode (mode, 0);
591 align = LOCAL_ALIGNMENT (type, align);
593 /* Try to find an available, already-allocated temporary of the proper
594 mode which meets the size and alignment requirements. Choose the
595 smallest one with the closest alignment.
597 If assign_stack_temp is called outside of the tree->rtl expansion,
598 we cannot reuse the stack slots (that may still refer to
599 VIRTUAL_STACK_VARS_REGNUM). */
600 if (!virtuals_instantiated)
602 for (p = avail_temp_slots; p; p = p->next)
604 if (p->align >= align && p->size >= size
605 && GET_MODE (p->slot) == mode
606 && objects_must_conflict_p (p->type, type)
607 && (best_p == 0 || best_p->size > p->size
608 || (best_p->size == p->size && best_p->align > p->align)))
610 if (p->align == align && p->size == size)
613 cut_slot_from_list (selected, &avail_temp_slots);
622 /* Make our best, if any, the one to use. */
626 cut_slot_from_list (selected, &avail_temp_slots);
628 /* If there are enough aligned bytes left over, make them into a new
629 temp_slot so that the extra bytes don't get wasted. Do this only
630 for BLKmode slots, so that we can be sure of the alignment. */
631 if (GET_MODE (best_p->slot) == BLKmode)
633 int alignment = best_p->align / BITS_PER_UNIT;
634 HOST_WIDE_INT rounded_size = CEIL_ROUND (size, alignment);
636 if (best_p->size - rounded_size >= alignment)
638 p = ggc_alloc (sizeof (struct temp_slot));
639 p->in_use = p->addr_taken = 0;
640 p->size = best_p->size - rounded_size;
641 p->base_offset = best_p->base_offset + rounded_size;
642 p->full_size = best_p->full_size - rounded_size;
643 p->slot = adjust_address_nv (best_p->slot, BLKmode, rounded_size);
644 p->align = best_p->align;
646 p->type = best_p->type;
647 insert_slot_to_list (p, &avail_temp_slots);
649 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, p->slot,
652 best_p->size = rounded_size;
653 best_p->full_size = rounded_size;
658 /* If we still didn't find one, make a new temporary. */
661 HOST_WIDE_INT frame_offset_old = frame_offset;
663 p = ggc_alloc (sizeof (struct temp_slot));
665 /* We are passing an explicit alignment request to assign_stack_local.
666 One side effect of that is assign_stack_local will not round SIZE
667 to ensure the frame offset remains suitably aligned.
669 So for requests which depended on the rounding of SIZE, we go ahead
670 and round it now. We also make sure ALIGNMENT is at least
671 BIGGEST_ALIGNMENT. */
672 gcc_assert (mode != BLKmode || align == BIGGEST_ALIGNMENT);
673 p->slot = assign_stack_local (mode,
675 ? CEIL_ROUND (size, (int) align / BITS_PER_UNIT)
681 /* The following slot size computation is necessary because we don't
682 know the actual size of the temporary slot until assign_stack_local
683 has performed all the frame alignment and size rounding for the
684 requested temporary. Note that extra space added for alignment
685 can be either above or below this stack slot depending on which
686 way the frame grows. We include the extra space if and only if it
687 is above this slot. */
688 if (FRAME_GROWS_DOWNWARD)
689 p->size = frame_offset_old - frame_offset;
693 /* Now define the fields used by combine_temp_slots. */
694 if (FRAME_GROWS_DOWNWARD)
696 p->base_offset = frame_offset;
697 p->full_size = frame_offset_old - frame_offset;
701 p->base_offset = frame_offset_old;
702 p->full_size = frame_offset - frame_offset_old;
713 p->level = temp_slot_level;
716 pp = temp_slots_at_level (p->level);
717 insert_slot_to_list (p, pp);
719 /* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
720 slot = gen_rtx_MEM (mode, XEXP (p->slot, 0));
721 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, slot, stack_slot_list);
723 /* If we know the alias set for the memory that will be used, use
724 it. If there's no TYPE, then we don't know anything about the
725 alias set for the memory. */
726 set_mem_alias_set (slot, type ? get_alias_set (type) : 0);
727 set_mem_align (slot, align);
729 /* If a type is specified, set the relevant flags. */
732 MEM_VOLATILE_P (slot) = TYPE_VOLATILE (type);
733 MEM_SET_IN_STRUCT_P (slot, (AGGREGATE_TYPE_P (type)
734 || TREE_CODE (type) == COMPLEX_TYPE));
736 MEM_NOTRAP_P (slot) = 1;
741 /* Allocate a temporary stack slot and record it for possible later
742 reuse. First three arguments are same as in preceding function. */
745 assign_stack_temp (enum machine_mode mode, HOST_WIDE_INT size, int keep)
747 return assign_stack_temp_for_type (mode, size, keep, NULL_TREE);
750 /* Assign a temporary.
751 If TYPE_OR_DECL is a decl, then we are doing it on behalf of the decl
752 and so that should be used in error messages. In either case, we
753 allocate of the given type.
754 KEEP is as for assign_stack_temp.
755 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
756 it is 0 if a register is OK.
757 DONT_PROMOTE is 1 if we should not promote values in register
761 assign_temp (tree type_or_decl, int keep, int memory_required,
762 int dont_promote ATTRIBUTE_UNUSED)
765 enum machine_mode mode;
770 if (DECL_P (type_or_decl))
771 decl = type_or_decl, type = TREE_TYPE (decl);
773 decl = NULL, type = type_or_decl;
775 mode = TYPE_MODE (type);
777 unsignedp = TYPE_UNSIGNED (type);
780 if (mode == BLKmode || memory_required)
782 HOST_WIDE_INT size = int_size_in_bytes (type);
785 /* Zero sized arrays are GNU C extension. Set size to 1 to avoid
786 problems with allocating the stack space. */
790 /* Unfortunately, we don't yet know how to allocate variable-sized
791 temporaries. However, sometimes we can find a fixed upper limit on
792 the size, so try that instead. */
794 size = max_int_size_in_bytes (type);
796 /* The size of the temporary may be too large to fit into an integer. */
797 /* ??? Not sure this should happen except for user silliness, so limit
798 this to things that aren't compiler-generated temporaries. The
799 rest of the time we'll die in assign_stack_temp_for_type. */
800 if (decl && size == -1
801 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST)
803 error ("size of variable %q+D is too large", decl);
807 tmp = assign_stack_temp_for_type (mode, size, keep, type);
813 mode = promote_mode (type, mode, &unsignedp, 0);
816 return gen_reg_rtx (mode);
819 /* Combine temporary stack slots which are adjacent on the stack.
821 This allows for better use of already allocated stack space. This is only
822 done for BLKmode slots because we can be sure that we won't have alignment
823 problems in this case. */
826 combine_temp_slots (void)
828 struct temp_slot *p, *q, *next, *next_q;
831 /* We can't combine slots, because the information about which slot
832 is in which alias set will be lost. */
833 if (flag_strict_aliasing)
836 /* If there are a lot of temp slots, don't do anything unless
837 high levels of optimization. */
838 if (! flag_expensive_optimizations)
839 for (p = avail_temp_slots, num_slots = 0; p; p = p->next, num_slots++)
840 if (num_slots > 100 || (num_slots > 10 && optimize == 0))
843 for (p = avail_temp_slots; p; p = next)
849 if (GET_MODE (p->slot) != BLKmode)
852 for (q = p->next; q; q = next_q)
858 if (GET_MODE (q->slot) != BLKmode)
861 if (p->base_offset + p->full_size == q->base_offset)
863 /* Q comes after P; combine Q into P. */
865 p->full_size += q->full_size;
868 else if (q->base_offset + q->full_size == p->base_offset)
870 /* P comes after Q; combine P into Q. */
872 q->full_size += p->full_size;
877 cut_slot_from_list (q, &avail_temp_slots);
880 /* Either delete P or advance past it. */
882 cut_slot_from_list (p, &avail_temp_slots);
886 /* Find the temp slot corresponding to the object at address X. */
888 static struct temp_slot *
889 find_temp_slot_from_address (rtx x)
895 for (i = max_slot_level (); i >= 0; i--)
896 for (p = *temp_slots_at_level (i); p; p = p->next)
898 if (XEXP (p->slot, 0) == x
900 || (GET_CODE (x) == PLUS
901 && XEXP (x, 0) == virtual_stack_vars_rtx
902 && GET_CODE (XEXP (x, 1)) == CONST_INT
903 && INTVAL (XEXP (x, 1)) >= p->base_offset
904 && INTVAL (XEXP (x, 1)) < p->base_offset + p->full_size))
907 else if (p->address != 0 && GET_CODE (p->address) == EXPR_LIST)
908 for (next = p->address; next; next = XEXP (next, 1))
909 if (XEXP (next, 0) == x)
913 /* If we have a sum involving a register, see if it points to a temp
915 if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 0))
916 && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
918 else if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 1))
919 && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
925 /* Indicate that NEW is an alternate way of referring to the temp slot
926 that previously was known by OLD. */
929 update_temp_slot_address (rtx old, rtx new)
933 if (rtx_equal_p (old, new))
936 p = find_temp_slot_from_address (old);
938 /* If we didn't find one, see if both OLD is a PLUS. If so, and NEW
939 is a register, see if one operand of the PLUS is a temporary
940 location. If so, NEW points into it. Otherwise, if both OLD and
941 NEW are a PLUS and if there is a register in common between them.
942 If so, try a recursive call on those values. */
945 if (GET_CODE (old) != PLUS)
950 update_temp_slot_address (XEXP (old, 0), new);
951 update_temp_slot_address (XEXP (old, 1), new);
954 else if (GET_CODE (new) != PLUS)
957 if (rtx_equal_p (XEXP (old, 0), XEXP (new, 0)))
958 update_temp_slot_address (XEXP (old, 1), XEXP (new, 1));
959 else if (rtx_equal_p (XEXP (old, 1), XEXP (new, 0)))
960 update_temp_slot_address (XEXP (old, 0), XEXP (new, 1));
961 else if (rtx_equal_p (XEXP (old, 0), XEXP (new, 1)))
962 update_temp_slot_address (XEXP (old, 1), XEXP (new, 0));
963 else if (rtx_equal_p (XEXP (old, 1), XEXP (new, 1)))
964 update_temp_slot_address (XEXP (old, 0), XEXP (new, 0));
969 /* Otherwise add an alias for the temp's address. */
970 else if (p->address == 0)
974 if (GET_CODE (p->address) != EXPR_LIST)
975 p->address = gen_rtx_EXPR_LIST (VOIDmode, p->address, NULL_RTX);
977 p->address = gen_rtx_EXPR_LIST (VOIDmode, new, p->address);
981 /* If X could be a reference to a temporary slot, mark the fact that its
982 address was taken. */
985 mark_temp_addr_taken (rtx x)
992 /* If X is not in memory or is at a constant address, it cannot be in
994 if (!MEM_P (x) || CONSTANT_P (XEXP (x, 0)))
997 p = find_temp_slot_from_address (XEXP (x, 0));
1002 /* If X could be a reference to a temporary slot, mark that slot as
1003 belonging to the to one level higher than the current level. If X
1004 matched one of our slots, just mark that one. Otherwise, we can't
1005 easily predict which it is, so upgrade all of them. Kept slots
1006 need not be touched.
1008 This is called when an ({...}) construct occurs and a statement
1009 returns a value in memory. */
1012 preserve_temp_slots (rtx x)
1014 struct temp_slot *p = 0, *next;
1016 /* If there is no result, we still might have some objects whose address
1017 were taken, so we need to make sure they stay around. */
1020 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1025 move_slot_to_level (p, temp_slot_level - 1);
1031 /* If X is a register that is being used as a pointer, see if we have
1032 a temporary slot we know it points to. To be consistent with
1033 the code below, we really should preserve all non-kept slots
1034 if we can't find a match, but that seems to be much too costly. */
1035 if (REG_P (x) && REG_POINTER (x))
1036 p = find_temp_slot_from_address (x);
1038 /* If X is not in memory or is at a constant address, it cannot be in
1039 a temporary slot, but it can contain something whose address was
1041 if (p == 0 && (!MEM_P (x) || CONSTANT_P (XEXP (x, 0))))
1043 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1048 move_slot_to_level (p, temp_slot_level - 1);
1054 /* First see if we can find a match. */
1056 p = find_temp_slot_from_address (XEXP (x, 0));
1060 /* Move everything at our level whose address was taken to our new
1061 level in case we used its address. */
1062 struct temp_slot *q;
1064 if (p->level == temp_slot_level)
1066 for (q = *temp_slots_at_level (temp_slot_level); q; q = next)
1070 if (p != q && q->addr_taken)
1071 move_slot_to_level (q, temp_slot_level - 1);
1074 move_slot_to_level (p, temp_slot_level - 1);
1080 /* Otherwise, preserve all non-kept slots at this level. */
1081 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1086 move_slot_to_level (p, temp_slot_level - 1);
1090 /* Free all temporaries used so far. This is normally called at the
1091 end of generating code for a statement. */
1094 free_temp_slots (void)
1096 struct temp_slot *p, *next;
1098 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1103 make_slot_available (p);
1106 combine_temp_slots ();
1109 /* Push deeper into the nesting level for stack temporaries. */
1112 push_temp_slots (void)
1117 /* Pop a temporary nesting level. All slots in use in the current level
1121 pop_temp_slots (void)
1123 struct temp_slot *p, *next;
1125 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1128 make_slot_available (p);
1131 combine_temp_slots ();
1136 /* Initialize temporary slots. */
1139 init_temp_slots (void)
1141 /* We have not allocated any temporaries yet. */
1142 avail_temp_slots = 0;
1143 used_temp_slots = 0;
1144 temp_slot_level = 0;
1147 /* These routines are responsible for converting virtual register references
1148 to the actual hard register references once RTL generation is complete.
1150 The following four variables are used for communication between the
1151 routines. They contain the offsets of the virtual registers from their
1152 respective hard registers. */
1154 static int in_arg_offset;
1155 static int var_offset;
1156 static int dynamic_offset;
1157 static int out_arg_offset;
1158 static int cfa_offset;
1160 /* In most machines, the stack pointer register is equivalent to the bottom
1163 #ifndef STACK_POINTER_OFFSET
1164 #define STACK_POINTER_OFFSET 0
1167 /* If not defined, pick an appropriate default for the offset of dynamically
1168 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
1169 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
1171 #ifndef STACK_DYNAMIC_OFFSET
1173 /* The bottom of the stack points to the actual arguments. If
1174 REG_PARM_STACK_SPACE is defined, this includes the space for the register
1175 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
1176 stack space for register parameters is not pushed by the caller, but
1177 rather part of the fixed stack areas and hence not included in
1178 `current_function_outgoing_args_size'. Nevertheless, we must allow
1179 for it when allocating stack dynamic objects. */
1181 #if defined(REG_PARM_STACK_SPACE)
1182 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1183 ((ACCUMULATE_OUTGOING_ARGS \
1184 ? (current_function_outgoing_args_size \
1185 + (OUTGOING_REG_PARM_STACK_SPACE ? 0 : REG_PARM_STACK_SPACE (FNDECL))) \
1186 : 0) + (STACK_POINTER_OFFSET))
1188 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1189 ((ACCUMULATE_OUTGOING_ARGS ? current_function_outgoing_args_size : 0) \
1190 + (STACK_POINTER_OFFSET))
1195 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
1196 is a virtual register, return the equivalent hard register and set the
1197 offset indirectly through the pointer. Otherwise, return 0. */
1200 instantiate_new_reg (rtx x, HOST_WIDE_INT *poffset)
1203 HOST_WIDE_INT offset;
1205 if (x == virtual_incoming_args_rtx)
1206 new = arg_pointer_rtx, offset = in_arg_offset;
1207 else if (x == virtual_stack_vars_rtx)
1208 new = frame_pointer_rtx, offset = var_offset;
1209 else if (x == virtual_stack_dynamic_rtx)
1210 new = stack_pointer_rtx, offset = dynamic_offset;
1211 else if (x == virtual_outgoing_args_rtx)
1212 new = stack_pointer_rtx, offset = out_arg_offset;
1213 else if (x == virtual_cfa_rtx)
1215 #ifdef FRAME_POINTER_CFA_OFFSET
1216 new = frame_pointer_rtx;
1218 new = arg_pointer_rtx;
1220 offset = cfa_offset;
1229 /* A subroutine of instantiate_virtual_regs, called via for_each_rtx.
1230 Instantiate any virtual registers present inside of *LOC. The expression
1231 is simplified, as much as possible, but is not to be considered "valid"
1232 in any sense implied by the target. If any change is made, set CHANGED
1236 instantiate_virtual_regs_in_rtx (rtx *loc, void *data)
1238 HOST_WIDE_INT offset;
1239 bool *changed = (bool *) data;
1246 switch (GET_CODE (x))
1249 new = instantiate_new_reg (x, &offset);
1252 *loc = plus_constant (new, offset);
1259 new = instantiate_new_reg (XEXP (x, 0), &offset);
1262 new = plus_constant (new, offset);
1263 *loc = simplify_gen_binary (PLUS, GET_MODE (x), new, XEXP (x, 1));
1269 /* FIXME -- from old code */
1270 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
1271 we can commute the PLUS and SUBREG because pointers into the
1272 frame are well-behaved. */
1282 /* A subroutine of instantiate_virtual_regs_in_insn. Return true if X
1283 matches the predicate for insn CODE operand OPERAND. */
1286 safe_insn_predicate (int code, int operand, rtx x)
1288 const struct insn_operand_data *op_data;
1293 op_data = &insn_data[code].operand[operand];
1294 if (op_data->predicate == NULL)
1297 return op_data->predicate (x, op_data->mode);
1300 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1301 registers present inside of insn. The result will be a valid insn. */
1304 instantiate_virtual_regs_in_insn (rtx insn)
1306 HOST_WIDE_INT offset;
1308 bool any_change = false;
1309 rtx set, new, x, seq;
1311 /* There are some special cases to be handled first. */
1312 set = single_set (insn);
1315 /* We're allowed to assign to a virtual register. This is interpreted
1316 to mean that the underlying register gets assigned the inverse
1317 transformation. This is used, for example, in the handling of
1319 new = instantiate_new_reg (SET_DEST (set), &offset);
1324 for_each_rtx (&SET_SRC (set), instantiate_virtual_regs_in_rtx, NULL);
1325 x = simplify_gen_binary (PLUS, GET_MODE (new), SET_SRC (set),
1327 x = force_operand (x, new);
1329 emit_move_insn (new, x);
1334 emit_insn_before (seq, insn);
1339 /* Handle a straight copy from a virtual register by generating a
1340 new add insn. The difference between this and falling through
1341 to the generic case is avoiding a new pseudo and eliminating a
1342 move insn in the initial rtl stream. */
1343 new = instantiate_new_reg (SET_SRC (set), &offset);
1344 if (new && offset != 0
1345 && REG_P (SET_DEST (set))
1346 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1350 x = expand_simple_binop (GET_MODE (SET_DEST (set)), PLUS,
1351 new, GEN_INT (offset), SET_DEST (set),
1352 1, OPTAB_LIB_WIDEN);
1353 if (x != SET_DEST (set))
1354 emit_move_insn (SET_DEST (set), x);
1359 emit_insn_before (seq, insn);
1364 extract_insn (insn);
1365 insn_code = INSN_CODE (insn);
1367 /* Handle a plus involving a virtual register by determining if the
1368 operands remain valid if they're modified in place. */
1369 if (GET_CODE (SET_SRC (set)) == PLUS
1370 && recog_data.n_operands >= 3
1371 && recog_data.operand_loc[1] == &XEXP (SET_SRC (set), 0)
1372 && recog_data.operand_loc[2] == &XEXP (SET_SRC (set), 1)
1373 && GET_CODE (recog_data.operand[2]) == CONST_INT
1374 && (new = instantiate_new_reg (recog_data.operand[1], &offset)))
1376 offset += INTVAL (recog_data.operand[2]);
1378 /* If the sum is zero, then replace with a plain move. */
1380 && REG_P (SET_DEST (set))
1381 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1384 emit_move_insn (SET_DEST (set), new);
1388 emit_insn_before (seq, insn);
1393 x = gen_int_mode (offset, recog_data.operand_mode[2]);
1395 /* Using validate_change and apply_change_group here leaves
1396 recog_data in an invalid state. Since we know exactly what
1397 we want to check, do those two by hand. */
1398 if (safe_insn_predicate (insn_code, 1, new)
1399 && safe_insn_predicate (insn_code, 2, x))
1401 *recog_data.operand_loc[1] = recog_data.operand[1] = new;
1402 *recog_data.operand_loc[2] = recog_data.operand[2] = x;
1405 /* Fall through into the regular operand fixup loop in
1406 order to take care of operands other than 1 and 2. */
1412 extract_insn (insn);
1413 insn_code = INSN_CODE (insn);
1416 /* In the general case, we expect virtual registers to appear only in
1417 operands, and then only as either bare registers or inside memories. */
1418 for (i = 0; i < recog_data.n_operands; ++i)
1420 x = recog_data.operand[i];
1421 switch (GET_CODE (x))
1425 rtx addr = XEXP (x, 0);
1426 bool changed = false;
1428 for_each_rtx (&addr, instantiate_virtual_regs_in_rtx, &changed);
1433 x = replace_equiv_address (x, addr);
1434 /* It may happen that the address with the virtual reg
1435 was valid (e.g. based on the virtual stack reg, which might
1436 be acceptable to the predicates with all offsets), whereas
1437 the address now isn't anymore, for instance when the address
1438 is still offsetted, but the base reg isn't virtual-stack-reg
1439 anymore. Below we would do a force_reg on the whole operand,
1440 but this insn might actually only accept memory. Hence,
1441 before doing that last resort, try to reload the address into
1442 a register, so this operand stays a MEM. */
1443 if (!safe_insn_predicate (insn_code, i, x))
1445 addr = force_reg (GET_MODE (addr), addr);
1446 x = replace_equiv_address (x, addr);
1451 emit_insn_before (seq, insn);
1456 new = instantiate_new_reg (x, &offset);
1465 /* Careful, special mode predicates may have stuff in
1466 insn_data[insn_code].operand[i].mode that isn't useful
1467 to us for computing a new value. */
1468 /* ??? Recognize address_operand and/or "p" constraints
1469 to see if (plus new offset) is a valid before we put
1470 this through expand_simple_binop. */
1471 x = expand_simple_binop (GET_MODE (x), PLUS, new,
1472 GEN_INT (offset), NULL_RTX,
1473 1, OPTAB_LIB_WIDEN);
1476 emit_insn_before (seq, insn);
1481 new = instantiate_new_reg (SUBREG_REG (x), &offset);
1487 new = expand_simple_binop (GET_MODE (new), PLUS, new,
1488 GEN_INT (offset), NULL_RTX,
1489 1, OPTAB_LIB_WIDEN);
1492 emit_insn_before (seq, insn);
1494 x = simplify_gen_subreg (recog_data.operand_mode[i], new,
1495 GET_MODE (new), SUBREG_BYTE (x));
1502 /* At this point, X contains the new value for the operand.
1503 Validate the new value vs the insn predicate. Note that
1504 asm insns will have insn_code -1 here. */
1505 if (!safe_insn_predicate (insn_code, i, x))
1508 x = force_reg (insn_data[insn_code].operand[i].mode, x);
1512 emit_insn_before (seq, insn);
1515 *recog_data.operand_loc[i] = recog_data.operand[i] = x;
1521 /* Propagate operand changes into the duplicates. */
1522 for (i = 0; i < recog_data.n_dups; ++i)
1523 *recog_data.dup_loc[i]
1524 = copy_rtx (recog_data.operand[(unsigned)recog_data.dup_num[i]]);
1526 /* Force re-recognition of the instruction for validation. */
1527 INSN_CODE (insn) = -1;
1530 if (asm_noperands (PATTERN (insn)) >= 0)
1532 if (!check_asm_operands (PATTERN (insn)))
1534 error_for_asm (insn, "impossible constraint in %<asm%>");
1540 if (recog_memoized (insn) < 0)
1541 fatal_insn_not_found (insn);
1545 /* Subroutine of instantiate_decls. Given RTL representing a decl,
1546 do any instantiation required. */
1549 instantiate_decl_rtl (rtx x)
1556 /* If this is a CONCAT, recurse for the pieces. */
1557 if (GET_CODE (x) == CONCAT)
1559 instantiate_decl_rtl (XEXP (x, 0));
1560 instantiate_decl_rtl (XEXP (x, 1));
1564 /* If this is not a MEM, no need to do anything. Similarly if the
1565 address is a constant or a register that is not a virtual register. */
1570 if (CONSTANT_P (addr)
1572 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
1573 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
1576 for_each_rtx (&XEXP (x, 0), instantiate_virtual_regs_in_rtx, NULL);
1579 /* Helper for instantiate_decls called via walk_tree: Process all decls
1580 in the given DECL_VALUE_EXPR. */
1583 instantiate_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1586 if (! EXPR_P (t) && ! GIMPLE_STMT_P (t))
1589 if (DECL_P (t) && DECL_RTL_SET_P (t))
1590 instantiate_decl_rtl (DECL_RTL (t));
1595 /* Subroutine of instantiate_decls: Process all decls in the given
1596 BLOCK node and all its subblocks. */
1599 instantiate_decls_1 (tree let)
1603 for (t = BLOCK_VARS (let); t; t = TREE_CHAIN (t))
1605 if (DECL_RTL_SET_P (t))
1606 instantiate_decl_rtl (DECL_RTL (t));
1607 if (TREE_CODE (t) == VAR_DECL && DECL_HAS_VALUE_EXPR_P (t))
1609 tree v = DECL_VALUE_EXPR (t);
1610 walk_tree (&v, instantiate_expr, NULL, NULL);
1614 /* Process all subblocks. */
1615 for (t = BLOCK_SUBBLOCKS (let); t; t = BLOCK_CHAIN (t))
1616 instantiate_decls_1 (t);
1619 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1620 all virtual registers in their DECL_RTL's. */
1623 instantiate_decls (tree fndecl)
1627 /* Process all parameters of the function. */
1628 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = TREE_CHAIN (decl))
1630 instantiate_decl_rtl (DECL_RTL (decl));
1631 instantiate_decl_rtl (DECL_INCOMING_RTL (decl));
1632 if (DECL_HAS_VALUE_EXPR_P (decl))
1634 tree v = DECL_VALUE_EXPR (decl);
1635 walk_tree (&v, instantiate_expr, NULL, NULL);
1639 /* Now process all variables defined in the function or its subblocks. */
1640 instantiate_decls_1 (DECL_INITIAL (fndecl));
1643 /* Pass through the INSNS of function FNDECL and convert virtual register
1644 references to hard register references. */
1647 instantiate_virtual_regs (void)
1651 /* Compute the offsets to use for this function. */
1652 in_arg_offset = FIRST_PARM_OFFSET (current_function_decl);
1653 var_offset = STARTING_FRAME_OFFSET;
1654 dynamic_offset = STACK_DYNAMIC_OFFSET (current_function_decl);
1655 out_arg_offset = STACK_POINTER_OFFSET;
1656 #ifdef FRAME_POINTER_CFA_OFFSET
1657 cfa_offset = FRAME_POINTER_CFA_OFFSET (current_function_decl);
1659 cfa_offset = ARG_POINTER_CFA_OFFSET (current_function_decl);
1662 /* Initialize recognition, indicating that volatile is OK. */
1665 /* Scan through all the insns, instantiating every virtual register still
1667 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
1670 /* These patterns in the instruction stream can never be recognized.
1671 Fortunately, they shouldn't contain virtual registers either. */
1672 if (GET_CODE (PATTERN (insn)) == USE
1673 || GET_CODE (PATTERN (insn)) == CLOBBER
1674 || GET_CODE (PATTERN (insn)) == ADDR_VEC
1675 || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC
1676 || GET_CODE (PATTERN (insn)) == ASM_INPUT)
1679 instantiate_virtual_regs_in_insn (insn);
1681 if (INSN_DELETED_P (insn))
1684 for_each_rtx (®_NOTES (insn), instantiate_virtual_regs_in_rtx, NULL);
1686 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
1687 if (GET_CODE (insn) == CALL_INSN)
1688 for_each_rtx (&CALL_INSN_FUNCTION_USAGE (insn),
1689 instantiate_virtual_regs_in_rtx, NULL);
1692 /* Instantiate the virtual registers in the DECLs for debugging purposes. */
1693 instantiate_decls (current_function_decl);
1695 targetm.instantiate_decls ();
1697 /* Indicate that, from now on, assign_stack_local should use
1698 frame_pointer_rtx. */
1699 virtuals_instantiated = 1;
1703 struct rtl_opt_pass pass_instantiate_virtual_regs =
1709 instantiate_virtual_regs, /* execute */
1712 0, /* static_pass_number */
1714 0, /* properties_required */
1715 0, /* properties_provided */
1716 0, /* properties_destroyed */
1717 0, /* todo_flags_start */
1718 TODO_dump_func /* todo_flags_finish */
1723 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
1724 This means a type for which function calls must pass an address to the
1725 function or get an address back from the function.
1726 EXP may be a type node or an expression (whose type is tested). */
1729 aggregate_value_p (const_tree exp, const_tree fntype)
1731 int i, regno, nregs;
1734 const_tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
1736 /* DECL node associated with FNTYPE when relevant, which we might need to
1737 check for by-invisible-reference returns, typically for CALL_EXPR input
1739 const_tree fndecl = NULL_TREE;
1742 switch (TREE_CODE (fntype))
1745 fndecl = get_callee_fndecl (fntype);
1746 fntype = fndecl ? TREE_TYPE (fndecl) : 0;
1750 fntype = TREE_TYPE (fndecl);
1755 case IDENTIFIER_NODE:
1759 /* We don't expect other rtl types here. */
1763 if (TREE_CODE (type) == VOID_TYPE)
1766 /* If the front end has decided that this needs to be passed by
1767 reference, do so. */
1768 if ((TREE_CODE (exp) == PARM_DECL || TREE_CODE (exp) == RESULT_DECL)
1769 && DECL_BY_REFERENCE (exp))
1772 /* If the EXPression is a CALL_EXPR, honor DECL_BY_REFERENCE set on the
1773 called function RESULT_DECL, meaning the function returns in memory by
1774 invisible reference. This check lets front-ends not set TREE_ADDRESSABLE
1775 on the function type, which used to be the way to request such a return
1776 mechanism but might now be causing troubles at gimplification time if
1777 temporaries with the function type need to be created. */
1778 if (TREE_CODE (exp) == CALL_EXPR && fndecl && DECL_RESULT (fndecl)
1779 && DECL_BY_REFERENCE (DECL_RESULT (fndecl)))
1782 if (targetm.calls.return_in_memory (type, fntype))
1784 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
1785 and thus can't be returned in registers. */
1786 if (TREE_ADDRESSABLE (type))
1788 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
1790 /* Make sure we have suitable call-clobbered regs to return
1791 the value in; if not, we must return it in memory. */
1792 reg = hard_function_value (type, 0, fntype, 0);
1794 /* If we have something other than a REG (e.g. a PARALLEL), then assume
1799 regno = REGNO (reg);
1800 nregs = hard_regno_nregs[regno][TYPE_MODE (type)];
1801 for (i = 0; i < nregs; i++)
1802 if (! call_used_regs[regno + i])
1807 /* Return true if we should assign DECL a pseudo register; false if it
1808 should live on the local stack. */
1811 use_register_for_decl (const_tree decl)
1813 /* Honor volatile. */
1814 if (TREE_SIDE_EFFECTS (decl))
1817 /* Honor addressability. */
1818 if (TREE_ADDRESSABLE (decl))
1821 /* Only register-like things go in registers. */
1822 if (DECL_MODE (decl) == BLKmode)
1825 /* If -ffloat-store specified, don't put explicit float variables
1827 /* ??? This should be checked after DECL_ARTIFICIAL, but tree-ssa
1828 propagates values across these stores, and it probably shouldn't. */
1829 if (flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)))
1832 /* If we're not interested in tracking debugging information for
1833 this decl, then we can certainly put it in a register. */
1834 if (DECL_IGNORED_P (decl))
1837 return (optimize || DECL_REGISTER (decl));
1840 /* Return true if TYPE should be passed by invisible reference. */
1843 pass_by_reference (CUMULATIVE_ARGS *ca, enum machine_mode mode,
1844 tree type, bool named_arg)
1848 /* If this type contains non-trivial constructors, then it is
1849 forbidden for the middle-end to create any new copies. */
1850 if (TREE_ADDRESSABLE (type))
1853 /* GCC post 3.4 passes *all* variable sized types by reference. */
1854 if (!TYPE_SIZE (type) || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
1858 return targetm.calls.pass_by_reference (ca, mode, type, named_arg);
1861 /* Return true if TYPE, which is passed by reference, should be callee
1862 copied instead of caller copied. */
1865 reference_callee_copied (CUMULATIVE_ARGS *ca, enum machine_mode mode,
1866 tree type, bool named_arg)
1868 if (type && TREE_ADDRESSABLE (type))
1870 return targetm.calls.callee_copies (ca, mode, type, named_arg);
1873 /* Structures to communicate between the subroutines of assign_parms.
1874 The first holds data persistent across all parameters, the second
1875 is cleared out for each parameter. */
1877 struct assign_parm_data_all
1879 CUMULATIVE_ARGS args_so_far;
1880 struct args_size stack_args_size;
1881 tree function_result_decl;
1883 rtx first_conversion_insn;
1884 rtx last_conversion_insn;
1885 HOST_WIDE_INT pretend_args_size;
1886 HOST_WIDE_INT extra_pretend_bytes;
1887 int reg_parm_stack_space;
1890 struct assign_parm_data_one
1896 enum machine_mode nominal_mode;
1897 enum machine_mode passed_mode;
1898 enum machine_mode promoted_mode;
1899 struct locate_and_pad_arg_data locate;
1901 BOOL_BITFIELD named_arg : 1;
1902 BOOL_BITFIELD passed_pointer : 1;
1903 BOOL_BITFIELD on_stack : 1;
1904 BOOL_BITFIELD loaded_in_reg : 1;
1907 /* A subroutine of assign_parms. Initialize ALL. */
1910 assign_parms_initialize_all (struct assign_parm_data_all *all)
1914 memset (all, 0, sizeof (*all));
1916 fntype = TREE_TYPE (current_function_decl);
1918 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
1919 INIT_CUMULATIVE_INCOMING_ARGS (all->args_so_far, fntype, NULL_RTX);
1921 INIT_CUMULATIVE_ARGS (all->args_so_far, fntype, NULL_RTX,
1922 current_function_decl, -1);
1925 #ifdef REG_PARM_STACK_SPACE
1926 all->reg_parm_stack_space = REG_PARM_STACK_SPACE (current_function_decl);
1930 /* If ARGS contains entries with complex types, split the entry into two
1931 entries of the component type. Return a new list of substitutions are
1932 needed, else the old list. */
1935 split_complex_args (tree args)
1939 /* Before allocating memory, check for the common case of no complex. */
1940 for (p = args; p; p = TREE_CHAIN (p))
1942 tree type = TREE_TYPE (p);
1943 if (TREE_CODE (type) == COMPLEX_TYPE
1944 && targetm.calls.split_complex_arg (type))
1950 args = copy_list (args);
1952 for (p = args; p; p = TREE_CHAIN (p))
1954 tree type = TREE_TYPE (p);
1955 if (TREE_CODE (type) == COMPLEX_TYPE
1956 && targetm.calls.split_complex_arg (type))
1959 tree subtype = TREE_TYPE (type);
1960 bool addressable = TREE_ADDRESSABLE (p);
1962 /* Rewrite the PARM_DECL's type with its component. */
1963 TREE_TYPE (p) = subtype;
1964 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
1965 DECL_MODE (p) = VOIDmode;
1966 DECL_SIZE (p) = NULL;
1967 DECL_SIZE_UNIT (p) = NULL;
1968 /* If this arg must go in memory, put it in a pseudo here.
1969 We can't allow it to go in memory as per normal parms,
1970 because the usual place might not have the imag part
1971 adjacent to the real part. */
1972 DECL_ARTIFICIAL (p) = addressable;
1973 DECL_IGNORED_P (p) = addressable;
1974 TREE_ADDRESSABLE (p) = 0;
1977 /* Build a second synthetic decl. */
1978 decl = build_decl (PARM_DECL, NULL_TREE, subtype);
1979 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
1980 DECL_ARTIFICIAL (decl) = addressable;
1981 DECL_IGNORED_P (decl) = addressable;
1982 layout_decl (decl, 0);
1984 /* Splice it in; skip the new decl. */
1985 TREE_CHAIN (decl) = TREE_CHAIN (p);
1986 TREE_CHAIN (p) = decl;
1994 /* A subroutine of assign_parms. Adjust the parameter list to incorporate
1995 the hidden struct return argument, and (abi willing) complex args.
1996 Return the new parameter list. */
1999 assign_parms_augmented_arg_list (struct assign_parm_data_all *all)
2001 tree fndecl = current_function_decl;
2002 tree fntype = TREE_TYPE (fndecl);
2003 tree fnargs = DECL_ARGUMENTS (fndecl);
2005 /* If struct value address is treated as the first argument, make it so. */
2006 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
2007 && ! current_function_returns_pcc_struct
2008 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
2010 tree type = build_pointer_type (TREE_TYPE (fntype));
2013 decl = build_decl (PARM_DECL, NULL_TREE, type);
2014 DECL_ARG_TYPE (decl) = type;
2015 DECL_ARTIFICIAL (decl) = 1;
2016 DECL_IGNORED_P (decl) = 1;
2018 TREE_CHAIN (decl) = fnargs;
2020 all->function_result_decl = decl;
2023 all->orig_fnargs = fnargs;
2025 /* If the target wants to split complex arguments into scalars, do so. */
2026 if (targetm.calls.split_complex_arg)
2027 fnargs = split_complex_args (fnargs);
2032 /* A subroutine of assign_parms. Examine PARM and pull out type and mode
2033 data for the parameter. Incorporate ABI specifics such as pass-by-
2034 reference and type promotion. */
2037 assign_parm_find_data_types (struct assign_parm_data_all *all, tree parm,
2038 struct assign_parm_data_one *data)
2040 tree nominal_type, passed_type;
2041 enum machine_mode nominal_mode, passed_mode, promoted_mode;
2043 memset (data, 0, sizeof (*data));
2045 /* NAMED_ARG is a mis-nomer. We really mean 'non-varadic'. */
2046 if (!current_function_stdarg)
2047 data->named_arg = 1; /* No varadic parms. */
2048 else if (TREE_CHAIN (parm))
2049 data->named_arg = 1; /* Not the last non-varadic parm. */
2050 else if (targetm.calls.strict_argument_naming (&all->args_so_far))
2051 data->named_arg = 1; /* Only varadic ones are unnamed. */
2053 data->named_arg = 0; /* Treat as varadic. */
2055 nominal_type = TREE_TYPE (parm);
2056 passed_type = DECL_ARG_TYPE (parm);
2058 /* Look out for errors propagating this far. Also, if the parameter's
2059 type is void then its value doesn't matter. */
2060 if (TREE_TYPE (parm) == error_mark_node
2061 /* This can happen after weird syntax errors
2062 or if an enum type is defined among the parms. */
2063 || TREE_CODE (parm) != PARM_DECL
2064 || passed_type == NULL
2065 || VOID_TYPE_P (nominal_type))
2067 nominal_type = passed_type = void_type_node;
2068 nominal_mode = passed_mode = promoted_mode = VOIDmode;
2072 /* Find mode of arg as it is passed, and mode of arg as it should be
2073 during execution of this function. */
2074 passed_mode = TYPE_MODE (passed_type);
2075 nominal_mode = TYPE_MODE (nominal_type);
2077 /* If the parm is to be passed as a transparent union, use the type of
2078 the first field for the tests below. We have already verified that
2079 the modes are the same. */
2080 if (TREE_CODE (passed_type) == UNION_TYPE
2081 && TYPE_TRANSPARENT_UNION (passed_type))
2082 passed_type = TREE_TYPE (TYPE_FIELDS (passed_type));
2084 /* See if this arg was passed by invisible reference. */
2085 if (pass_by_reference (&all->args_so_far, passed_mode,
2086 passed_type, data->named_arg))
2088 passed_type = nominal_type = build_pointer_type (passed_type);
2089 data->passed_pointer = true;
2090 passed_mode = nominal_mode = Pmode;
2093 /* Find mode as it is passed by the ABI. */
2094 promoted_mode = passed_mode;
2095 if (targetm.calls.promote_function_args (TREE_TYPE (current_function_decl)))
2097 int unsignedp = TYPE_UNSIGNED (passed_type);
2098 promoted_mode = promote_mode (passed_type, promoted_mode,
2103 data->nominal_type = nominal_type;
2104 data->passed_type = passed_type;
2105 data->nominal_mode = nominal_mode;
2106 data->passed_mode = passed_mode;
2107 data->promoted_mode = promoted_mode;
2110 /* A subroutine of assign_parms. Invoke setup_incoming_varargs. */
2113 assign_parms_setup_varargs (struct assign_parm_data_all *all,
2114 struct assign_parm_data_one *data, bool no_rtl)
2116 int varargs_pretend_bytes = 0;
2118 targetm.calls.setup_incoming_varargs (&all->args_so_far,
2119 data->promoted_mode,
2121 &varargs_pretend_bytes, no_rtl);
2123 /* If the back-end has requested extra stack space, record how much is
2124 needed. Do not change pretend_args_size otherwise since it may be
2125 nonzero from an earlier partial argument. */
2126 if (varargs_pretend_bytes > 0)
2127 all->pretend_args_size = varargs_pretend_bytes;
2130 /* A subroutine of assign_parms. Set DATA->ENTRY_PARM corresponding to
2131 the incoming location of the current parameter. */
2134 assign_parm_find_entry_rtl (struct assign_parm_data_all *all,
2135 struct assign_parm_data_one *data)
2137 HOST_WIDE_INT pretend_bytes = 0;
2141 if (data->promoted_mode == VOIDmode)
2143 data->entry_parm = data->stack_parm = const0_rtx;
2147 #ifdef FUNCTION_INCOMING_ARG
2148 entry_parm = FUNCTION_INCOMING_ARG (all->args_so_far, data->promoted_mode,
2149 data->passed_type, data->named_arg);
2151 entry_parm = FUNCTION_ARG (all->args_so_far, data->promoted_mode,
2152 data->passed_type, data->named_arg);
2155 if (entry_parm == 0)
2156 data->promoted_mode = data->passed_mode;
2158 /* Determine parm's home in the stack, in case it arrives in the stack
2159 or we should pretend it did. Compute the stack position and rtx where
2160 the argument arrives and its size.
2162 There is one complexity here: If this was a parameter that would
2163 have been passed in registers, but wasn't only because it is
2164 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2165 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2166 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of 0
2167 as it was the previous time. */
2168 in_regs = entry_parm != 0;
2169 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2172 if (!in_regs && !data->named_arg)
2174 if (targetm.calls.pretend_outgoing_varargs_named (&all->args_so_far))
2177 #ifdef FUNCTION_INCOMING_ARG
2178 tem = FUNCTION_INCOMING_ARG (all->args_so_far, data->promoted_mode,
2179 data->passed_type, true);
2181 tem = FUNCTION_ARG (all->args_so_far, data->promoted_mode,
2182 data->passed_type, true);
2184 in_regs = tem != NULL;
2188 /* If this parameter was passed both in registers and in the stack, use
2189 the copy on the stack. */
2190 if (targetm.calls.must_pass_in_stack (data->promoted_mode,
2198 partial = targetm.calls.arg_partial_bytes (&all->args_so_far,
2199 data->promoted_mode,
2202 data->partial = partial;
2204 /* The caller might already have allocated stack space for the
2205 register parameters. */
2206 if (partial != 0 && all->reg_parm_stack_space == 0)
2208 /* Part of this argument is passed in registers and part
2209 is passed on the stack. Ask the prologue code to extend
2210 the stack part so that we can recreate the full value.
2212 PRETEND_BYTES is the size of the registers we need to store.
2213 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
2214 stack space that the prologue should allocate.
2216 Internally, gcc assumes that the argument pointer is aligned
2217 to STACK_BOUNDARY bits. This is used both for alignment
2218 optimizations (see init_emit) and to locate arguments that are
2219 aligned to more than PARM_BOUNDARY bits. We must preserve this
2220 invariant by rounding CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to
2221 a stack boundary. */
2223 /* We assume at most one partial arg, and it must be the first
2224 argument on the stack. */
2225 gcc_assert (!all->extra_pretend_bytes && !all->pretend_args_size);
2227 pretend_bytes = partial;
2228 all->pretend_args_size = CEIL_ROUND (pretend_bytes, STACK_BYTES);
2230 /* We want to align relative to the actual stack pointer, so
2231 don't include this in the stack size until later. */
2232 all->extra_pretend_bytes = all->pretend_args_size;
2236 locate_and_pad_parm (data->promoted_mode, data->passed_type, in_regs,
2237 entry_parm ? data->partial : 0, current_function_decl,
2238 &all->stack_args_size, &data->locate);
2240 /* Adjust offsets to include the pretend args. */
2241 pretend_bytes = all->extra_pretend_bytes - pretend_bytes;
2242 data->locate.slot_offset.constant += pretend_bytes;
2243 data->locate.offset.constant += pretend_bytes;
2245 data->entry_parm = entry_parm;
2248 /* A subroutine of assign_parms. If there is actually space on the stack
2249 for this parm, count it in stack_args_size and return true. */
2252 assign_parm_is_stack_parm (struct assign_parm_data_all *all,
2253 struct assign_parm_data_one *data)
2255 /* Trivially true if we've no incoming register. */
2256 if (data->entry_parm == NULL)
2258 /* Also true if we're partially in registers and partially not,
2259 since we've arranged to drop the entire argument on the stack. */
2260 else if (data->partial != 0)
2262 /* Also true if the target says that it's passed in both registers
2263 and on the stack. */
2264 else if (GET_CODE (data->entry_parm) == PARALLEL
2265 && XEXP (XVECEXP (data->entry_parm, 0, 0), 0) == NULL_RTX)
2267 /* Also true if the target says that there's stack allocated for
2268 all register parameters. */
2269 else if (all->reg_parm_stack_space > 0)
2271 /* Otherwise, no, this parameter has no ABI defined stack slot. */
2275 all->stack_args_size.constant += data->locate.size.constant;
2276 if (data->locate.size.var)
2277 ADD_PARM_SIZE (all->stack_args_size, data->locate.size.var);
2282 /* A subroutine of assign_parms. Given that this parameter is allocated
2283 stack space by the ABI, find it. */
2286 assign_parm_find_stack_rtl (tree parm, struct assign_parm_data_one *data)
2288 rtx offset_rtx, stack_parm;
2289 unsigned int align, boundary;
2291 /* If we're passing this arg using a reg, make its stack home the
2292 aligned stack slot. */
2293 if (data->entry_parm)
2294 offset_rtx = ARGS_SIZE_RTX (data->locate.slot_offset);
2296 offset_rtx = ARGS_SIZE_RTX (data->locate.offset);
2298 stack_parm = current_function_internal_arg_pointer;
2299 if (offset_rtx != const0_rtx)
2300 stack_parm = gen_rtx_PLUS (Pmode, stack_parm, offset_rtx);
2301 stack_parm = gen_rtx_MEM (data->promoted_mode, stack_parm);
2303 set_mem_attributes (stack_parm, parm, 1);
2305 boundary = data->locate.boundary;
2306 align = BITS_PER_UNIT;
2308 /* If we're padding upward, we know that the alignment of the slot
2309 is FUNCTION_ARG_BOUNDARY. If we're using slot_offset, we're
2310 intentionally forcing upward padding. Otherwise we have to come
2311 up with a guess at the alignment based on OFFSET_RTX. */
2312 if (data->locate.where_pad != downward || data->entry_parm)
2314 else if (GET_CODE (offset_rtx) == CONST_INT)
2316 align = INTVAL (offset_rtx) * BITS_PER_UNIT | boundary;
2317 align = align & -align;
2319 set_mem_align (stack_parm, align);
2321 if (data->entry_parm)
2322 set_reg_attrs_for_parm (data->entry_parm, stack_parm);
2324 data->stack_parm = stack_parm;
2327 /* A subroutine of assign_parms. Adjust DATA->ENTRY_RTL such that it's
2328 always valid and contiguous. */
2331 assign_parm_adjust_entry_rtl (struct assign_parm_data_one *data)
2333 rtx entry_parm = data->entry_parm;
2334 rtx stack_parm = data->stack_parm;
2336 /* If this parm was passed part in regs and part in memory, pretend it
2337 arrived entirely in memory by pushing the register-part onto the stack.
2338 In the special case of a DImode or DFmode that is split, we could put
2339 it together in a pseudoreg directly, but for now that's not worth
2341 if (data->partial != 0)
2343 /* Handle calls that pass values in multiple non-contiguous
2344 locations. The Irix 6 ABI has examples of this. */
2345 if (GET_CODE (entry_parm) == PARALLEL)
2346 emit_group_store (validize_mem (stack_parm), entry_parm,
2348 int_size_in_bytes (data->passed_type));
2351 gcc_assert (data->partial % UNITS_PER_WORD == 0);
2352 move_block_from_reg (REGNO (entry_parm), validize_mem (stack_parm),
2353 data->partial / UNITS_PER_WORD);
2356 entry_parm = stack_parm;
2359 /* If we didn't decide this parm came in a register, by default it came
2361 else if (entry_parm == NULL)
2362 entry_parm = stack_parm;
2364 /* When an argument is passed in multiple locations, we can't make use
2365 of this information, but we can save some copying if the whole argument
2366 is passed in a single register. */
2367 else if (GET_CODE (entry_parm) == PARALLEL
2368 && data->nominal_mode != BLKmode
2369 && data->passed_mode != BLKmode)
2371 size_t i, len = XVECLEN (entry_parm, 0);
2373 for (i = 0; i < len; i++)
2374 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
2375 && REG_P (XEXP (XVECEXP (entry_parm, 0, i), 0))
2376 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
2377 == data->passed_mode)
2378 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
2380 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
2385 data->entry_parm = entry_parm;
2388 /* A subroutine of assign_parms. Adjust DATA->STACK_RTL such that it's
2389 always valid and properly aligned. */
2392 assign_parm_adjust_stack_rtl (struct assign_parm_data_one *data)
2394 rtx stack_parm = data->stack_parm;
2396 /* If we can't trust the parm stack slot to be aligned enough for its
2397 ultimate type, don't use that slot after entry. We'll make another
2398 stack slot, if we need one. */
2400 && ((STRICT_ALIGNMENT
2401 && GET_MODE_ALIGNMENT (data->nominal_mode) > MEM_ALIGN (stack_parm))
2402 || (data->nominal_type
2403 && TYPE_ALIGN (data->nominal_type) > MEM_ALIGN (stack_parm)
2404 && MEM_ALIGN (stack_parm) < PREFERRED_STACK_BOUNDARY)))
2407 /* If parm was passed in memory, and we need to convert it on entry,
2408 don't store it back in that same slot. */
2409 else if (data->entry_parm == stack_parm
2410 && data->nominal_mode != BLKmode
2411 && data->nominal_mode != data->passed_mode)
2414 /* If stack protection is in effect for this function, don't leave any
2415 pointers in their passed stack slots. */
2416 else if (cfun->stack_protect_guard
2417 && (flag_stack_protect == 2
2418 || data->passed_pointer
2419 || POINTER_TYPE_P (data->nominal_type)))
2422 data->stack_parm = stack_parm;
2425 /* A subroutine of assign_parms. Return true if the current parameter
2426 should be stored as a BLKmode in the current frame. */
2429 assign_parm_setup_block_p (struct assign_parm_data_one *data)
2431 if (data->nominal_mode == BLKmode)
2433 if (GET_CODE (data->entry_parm) == PARALLEL)
2436 #ifdef BLOCK_REG_PADDING
2437 /* Only assign_parm_setup_block knows how to deal with register arguments
2438 that are padded at the least significant end. */
2439 if (REG_P (data->entry_parm)
2440 && GET_MODE_SIZE (data->promoted_mode) < UNITS_PER_WORD
2441 && (BLOCK_REG_PADDING (data->passed_mode, data->passed_type, 1)
2442 == (BYTES_BIG_ENDIAN ? upward : downward)))
2449 /* A subroutine of assign_parms. Arrange for the parameter to be
2450 present and valid in DATA->STACK_RTL. */
2453 assign_parm_setup_block (struct assign_parm_data_all *all,
2454 tree parm, struct assign_parm_data_one *data)
2456 rtx entry_parm = data->entry_parm;
2457 rtx stack_parm = data->stack_parm;
2459 HOST_WIDE_INT size_stored;
2460 rtx orig_entry_parm = entry_parm;
2462 if (GET_CODE (entry_parm) == PARALLEL)
2463 entry_parm = emit_group_move_into_temps (entry_parm);
2465 /* If we've a non-block object that's nevertheless passed in parts,
2466 reconstitute it in register operations rather than on the stack. */
2467 if (GET_CODE (entry_parm) == PARALLEL
2468 && data->nominal_mode != BLKmode)
2470 rtx elt0 = XEXP (XVECEXP (orig_entry_parm, 0, 0), 0);
2472 if ((XVECLEN (entry_parm, 0) > 1
2473 || hard_regno_nregs[REGNO (elt0)][GET_MODE (elt0)] > 1)
2474 && use_register_for_decl (parm))
2476 rtx parmreg = gen_reg_rtx (data->nominal_mode);
2478 push_to_sequence2 (all->first_conversion_insn,
2479 all->last_conversion_insn);
2481 /* For values returned in multiple registers, handle possible
2482 incompatible calls to emit_group_store.
2484 For example, the following would be invalid, and would have to
2485 be fixed by the conditional below:
2487 emit_group_store ((reg:SF), (parallel:DF))
2488 emit_group_store ((reg:SI), (parallel:DI))
2490 An example of this are doubles in e500 v2:
2491 (parallel:DF (expr_list (reg:SI) (const_int 0))
2492 (expr_list (reg:SI) (const_int 4))). */
2493 if (data->nominal_mode != data->passed_mode)
2495 rtx t = gen_reg_rtx (GET_MODE (entry_parm));
2496 emit_group_store (t, entry_parm, NULL_TREE,
2497 GET_MODE_SIZE (GET_MODE (entry_parm)));
2498 convert_move (parmreg, t, 0);
2501 emit_group_store (parmreg, entry_parm, data->nominal_type,
2502 int_size_in_bytes (data->nominal_type));
2504 all->first_conversion_insn = get_insns ();
2505 all->last_conversion_insn = get_last_insn ();
2508 SET_DECL_RTL (parm, parmreg);
2513 size = int_size_in_bytes (data->passed_type);
2514 size_stored = CEIL_ROUND (size, UNITS_PER_WORD);
2515 if (stack_parm == 0)
2517 DECL_ALIGN (parm) = MAX (DECL_ALIGN (parm), BITS_PER_WORD);
2518 stack_parm = assign_stack_local (BLKmode, size_stored,
2520 if (GET_MODE_SIZE (GET_MODE (entry_parm)) == size)
2521 PUT_MODE (stack_parm, GET_MODE (entry_parm));
2522 set_mem_attributes (stack_parm, parm, 1);
2525 /* If a BLKmode arrives in registers, copy it to a stack slot. Handle
2526 calls that pass values in multiple non-contiguous locations. */
2527 if (REG_P (entry_parm) || GET_CODE (entry_parm) == PARALLEL)
2531 /* Note that we will be storing an integral number of words.
2532 So we have to be careful to ensure that we allocate an
2533 integral number of words. We do this above when we call
2534 assign_stack_local if space was not allocated in the argument
2535 list. If it was, this will not work if PARM_BOUNDARY is not
2536 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2537 if it becomes a problem. Exception is when BLKmode arrives
2538 with arguments not conforming to word_mode. */
2540 if (data->stack_parm == 0)
2542 else if (GET_CODE (entry_parm) == PARALLEL)
2545 gcc_assert (!size || !(PARM_BOUNDARY % BITS_PER_WORD));
2547 mem = validize_mem (stack_parm);
2549 /* Handle values in multiple non-contiguous locations. */
2550 if (GET_CODE (entry_parm) == PARALLEL)
2552 push_to_sequence2 (all->first_conversion_insn,
2553 all->last_conversion_insn);
2554 emit_group_store (mem, entry_parm, data->passed_type, size);
2555 all->first_conversion_insn = get_insns ();
2556 all->last_conversion_insn = get_last_insn ();
2563 /* If SIZE is that of a mode no bigger than a word, just use
2564 that mode's store operation. */
2565 else if (size <= UNITS_PER_WORD)
2567 enum machine_mode mode
2568 = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
2571 #ifdef BLOCK_REG_PADDING
2572 && (size == UNITS_PER_WORD
2573 || (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2574 != (BYTES_BIG_ENDIAN ? upward : downward)))
2580 /* We are really truncating a word_mode value containing
2581 SIZE bytes into a value of mode MODE. If such an
2582 operation requires no actual instructions, we can refer
2583 to the value directly in mode MODE, otherwise we must
2584 start with the register in word_mode and explicitly
2586 if (TRULY_NOOP_TRUNCATION (size * BITS_PER_UNIT, BITS_PER_WORD))
2587 reg = gen_rtx_REG (mode, REGNO (entry_parm));
2590 reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
2591 reg = convert_to_mode (mode, copy_to_reg (reg), 1);
2593 emit_move_insn (change_address (mem, mode, 0), reg);
2596 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
2597 machine must be aligned to the left before storing
2598 to memory. Note that the previous test doesn't
2599 handle all cases (e.g. SIZE == 3). */
2600 else if (size != UNITS_PER_WORD
2601 #ifdef BLOCK_REG_PADDING
2602 && (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2610 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
2611 rtx reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
2613 x = expand_shift (LSHIFT_EXPR, word_mode, reg,
2614 build_int_cst (NULL_TREE, by),
2616 tem = change_address (mem, word_mode, 0);
2617 emit_move_insn (tem, x);
2620 move_block_from_reg (REGNO (entry_parm), mem,
2621 size_stored / UNITS_PER_WORD);
2624 move_block_from_reg (REGNO (entry_parm), mem,
2625 size_stored / UNITS_PER_WORD);
2627 else if (data->stack_parm == 0)
2629 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2630 emit_block_move (stack_parm, data->entry_parm, GEN_INT (size),
2632 all->first_conversion_insn = get_insns ();
2633 all->last_conversion_insn = get_last_insn ();
2637 data->stack_parm = stack_parm;
2638 SET_DECL_RTL (parm, stack_parm);
2641 /* A subroutine of assign_parms. Allocate a pseudo to hold the current
2642 parameter. Get it there. Perform all ABI specified conversions. */
2645 assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm,
2646 struct assign_parm_data_one *data)
2649 enum machine_mode promoted_nominal_mode;
2650 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (parm));
2651 bool did_conversion = false;
2653 /* Store the parm in a pseudoregister during the function, but we may
2654 need to do it in a wider mode. */
2656 /* This is not really promoting for a call. However we need to be
2657 consistent with assign_parm_find_data_types and expand_expr_real_1. */
2658 promoted_nominal_mode
2659 = promote_mode (data->nominal_type, data->nominal_mode, &unsignedp, 1);
2661 parmreg = gen_reg_rtx (promoted_nominal_mode);
2663 if (!DECL_ARTIFICIAL (parm))
2664 mark_user_reg (parmreg);
2666 /* If this was an item that we received a pointer to,
2667 set DECL_RTL appropriately. */
2668 if (data->passed_pointer)
2670 rtx x = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data->passed_type)), parmreg);
2671 set_mem_attributes (x, parm, 1);
2672 SET_DECL_RTL (parm, x);
2675 SET_DECL_RTL (parm, parmreg);
2677 /* Copy the value into the register. */
2678 if (data->nominal_mode != data->passed_mode
2679 || promoted_nominal_mode != data->promoted_mode)
2683 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
2684 mode, by the caller. We now have to convert it to
2685 NOMINAL_MODE, if different. However, PARMREG may be in
2686 a different mode than NOMINAL_MODE if it is being stored
2689 If ENTRY_PARM is a hard register, it might be in a register
2690 not valid for operating in its mode (e.g., an odd-numbered
2691 register for a DFmode). In that case, moves are the only
2692 thing valid, so we can't do a convert from there. This
2693 occurs when the calling sequence allow such misaligned
2696 In addition, the conversion may involve a call, which could
2697 clobber parameters which haven't been copied to pseudo
2698 registers yet. Therefore, we must first copy the parm to
2699 a pseudo reg here, and save the conversion until after all
2700 parameters have been moved. */
2702 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
2704 emit_move_insn (tempreg, validize_mem (data->entry_parm));
2706 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2707 tempreg = convert_to_mode (data->nominal_mode, tempreg, unsignedp);
2709 if (GET_CODE (tempreg) == SUBREG
2710 && GET_MODE (tempreg) == data->nominal_mode
2711 && REG_P (SUBREG_REG (tempreg))
2712 && data->nominal_mode == data->passed_mode
2713 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (data->entry_parm)
2714 && GET_MODE_SIZE (GET_MODE (tempreg))
2715 < GET_MODE_SIZE (GET_MODE (data->entry_parm)))
2717 /* The argument is already sign/zero extended, so note it
2719 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
2720 SUBREG_PROMOTED_UNSIGNED_SET (tempreg, unsignedp);
2723 /* TREE_USED gets set erroneously during expand_assignment. */
2724 save_tree_used = TREE_USED (parm);
2725 expand_assignment (parm, make_tree (data->nominal_type, tempreg), false);
2726 TREE_USED (parm) = save_tree_used;
2727 all->first_conversion_insn = get_insns ();
2728 all->last_conversion_insn = get_last_insn ();
2731 did_conversion = true;
2734 emit_move_insn (parmreg, validize_mem (data->entry_parm));
2736 /* If we were passed a pointer but the actual value can safely live
2737 in a register, put it in one. */
2738 if (data->passed_pointer
2739 && TYPE_MODE (TREE_TYPE (parm)) != BLKmode
2740 /* If by-reference argument was promoted, demote it. */
2741 && (TYPE_MODE (TREE_TYPE (parm)) != GET_MODE (DECL_RTL (parm))
2742 || use_register_for_decl (parm)))
2744 /* We can't use nominal_mode, because it will have been set to
2745 Pmode above. We must use the actual mode of the parm. */
2746 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
2747 mark_user_reg (parmreg);
2749 if (GET_MODE (parmreg) != GET_MODE (DECL_RTL (parm)))
2751 rtx tempreg = gen_reg_rtx (GET_MODE (DECL_RTL (parm)));
2752 int unsigned_p = TYPE_UNSIGNED (TREE_TYPE (parm));
2754 push_to_sequence2 (all->first_conversion_insn,
2755 all->last_conversion_insn);
2756 emit_move_insn (tempreg, DECL_RTL (parm));
2757 tempreg = convert_to_mode (GET_MODE (parmreg), tempreg, unsigned_p);
2758 emit_move_insn (parmreg, tempreg);
2759 all->first_conversion_insn = get_insns ();
2760 all->last_conversion_insn = get_last_insn ();
2763 did_conversion = true;
2766 emit_move_insn (parmreg, DECL_RTL (parm));
2768 SET_DECL_RTL (parm, parmreg);
2770 /* STACK_PARM is the pointer, not the parm, and PARMREG is
2772 data->stack_parm = NULL;
2775 /* Mark the register as eliminable if we did no conversion and it was
2776 copied from memory at a fixed offset, and the arg pointer was not
2777 copied to a pseudo-reg. If the arg pointer is a pseudo reg or the
2778 offset formed an invalid address, such memory-equivalences as we
2779 make here would screw up life analysis for it. */
2780 if (data->nominal_mode == data->passed_mode
2782 && data->stack_parm != 0
2783 && MEM_P (data->stack_parm)
2784 && data->locate.offset.var == 0
2785 && reg_mentioned_p (virtual_incoming_args_rtx,
2786 XEXP (data->stack_parm, 0)))
2788 rtx linsn = get_last_insn ();
2791 /* Mark complex types separately. */
2792 if (GET_CODE (parmreg) == CONCAT)
2794 enum machine_mode submode
2795 = GET_MODE_INNER (GET_MODE (parmreg));
2796 int regnor = REGNO (XEXP (parmreg, 0));
2797 int regnoi = REGNO (XEXP (parmreg, 1));
2798 rtx stackr = adjust_address_nv (data->stack_parm, submode, 0);
2799 rtx stacki = adjust_address_nv (data->stack_parm, submode,
2800 GET_MODE_SIZE (submode));
2802 /* Scan backwards for the set of the real and
2804 for (sinsn = linsn; sinsn != 0;
2805 sinsn = prev_nonnote_insn (sinsn))
2807 set = single_set (sinsn);
2811 if (SET_DEST (set) == regno_reg_rtx [regnoi])
2812 set_unique_reg_note (sinsn, REG_EQUIV, stacki);
2813 else if (SET_DEST (set) == regno_reg_rtx [regnor])
2814 set_unique_reg_note (sinsn, REG_EQUIV, stackr);
2817 else if ((set = single_set (linsn)) != 0
2818 && SET_DEST (set) == parmreg)
2819 set_unique_reg_note (linsn, REG_EQUIV, data->stack_parm);
2822 /* For pointer data type, suggest pointer register. */
2823 if (POINTER_TYPE_P (TREE_TYPE (parm)))
2824 mark_reg_pointer (parmreg,
2825 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
2828 /* A subroutine of assign_parms. Allocate stack space to hold the current
2829 parameter. Get it there. Perform all ABI specified conversions. */
2832 assign_parm_setup_stack (struct assign_parm_data_all *all, tree parm,
2833 struct assign_parm_data_one *data)
2835 /* Value must be stored in the stack slot STACK_PARM during function
2837 bool to_conversion = false;
2839 if (data->promoted_mode != data->nominal_mode)
2841 /* Conversion is required. */
2842 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
2844 emit_move_insn (tempreg, validize_mem (data->entry_parm));
2846 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2847 to_conversion = true;
2849 data->entry_parm = convert_to_mode (data->nominal_mode, tempreg,
2850 TYPE_UNSIGNED (TREE_TYPE (parm)));
2852 if (data->stack_parm)
2853 /* ??? This may need a big-endian conversion on sparc64. */
2855 = adjust_address (data->stack_parm, data->nominal_mode, 0);
2858 if (data->entry_parm != data->stack_parm)
2862 if (data->stack_parm == 0)
2865 = assign_stack_local (GET_MODE (data->entry_parm),
2866 GET_MODE_SIZE (GET_MODE (data->entry_parm)),
2867 TYPE_ALIGN (data->passed_type));
2868 set_mem_attributes (data->stack_parm, parm, 1);
2871 dest = validize_mem (data->stack_parm);
2872 src = validize_mem (data->entry_parm);
2876 /* Use a block move to handle potentially misaligned entry_parm. */
2878 push_to_sequence2 (all->first_conversion_insn,
2879 all->last_conversion_insn);
2880 to_conversion = true;
2882 emit_block_move (dest, src,
2883 GEN_INT (int_size_in_bytes (data->passed_type)),
2887 emit_move_insn (dest, src);
2892 all->first_conversion_insn = get_insns ();
2893 all->last_conversion_insn = get_last_insn ();
2897 SET_DECL_RTL (parm, data->stack_parm);
2900 /* A subroutine of assign_parms. If the ABI splits complex arguments, then
2901 undo the frobbing that we did in assign_parms_augmented_arg_list. */
2904 assign_parms_unsplit_complex (struct assign_parm_data_all *all, tree fnargs)
2907 tree orig_fnargs = all->orig_fnargs;
2909 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm))
2911 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
2912 && targetm.calls.split_complex_arg (TREE_TYPE (parm)))
2914 rtx tmp, real, imag;
2915 enum machine_mode inner = GET_MODE_INNER (DECL_MODE (parm));
2917 real = DECL_RTL (fnargs);
2918 imag = DECL_RTL (TREE_CHAIN (fnargs));
2919 if (inner != GET_MODE (real))
2921 real = gen_lowpart_SUBREG (inner, real);
2922 imag = gen_lowpart_SUBREG (inner, imag);
2925 if (TREE_ADDRESSABLE (parm))
2928 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (parm));
2930 /* split_complex_arg put the real and imag parts in
2931 pseudos. Move them to memory. */
2932 tmp = assign_stack_local (DECL_MODE (parm), size,
2933 TYPE_ALIGN (TREE_TYPE (parm)));
2934 set_mem_attributes (tmp, parm, 1);
2935 rmem = adjust_address_nv (tmp, inner, 0);
2936 imem = adjust_address_nv (tmp, inner, GET_MODE_SIZE (inner));
2937 push_to_sequence2 (all->first_conversion_insn,
2938 all->last_conversion_insn);
2939 emit_move_insn (rmem, real);
2940 emit_move_insn (imem, imag);
2941 all->first_conversion_insn = get_insns ();
2942 all->last_conversion_insn = get_last_insn ();
2946 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
2947 SET_DECL_RTL (parm, tmp);
2949 real = DECL_INCOMING_RTL (fnargs);
2950 imag = DECL_INCOMING_RTL (TREE_CHAIN (fnargs));
2951 if (inner != GET_MODE (real))
2953 real = gen_lowpart_SUBREG (inner, real);
2954 imag = gen_lowpart_SUBREG (inner, imag);
2956 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
2957 set_decl_incoming_rtl (parm, tmp, false);
2958 fnargs = TREE_CHAIN (fnargs);
2962 SET_DECL_RTL (parm, DECL_RTL (fnargs));
2963 set_decl_incoming_rtl (parm, DECL_INCOMING_RTL (fnargs), false);
2965 /* Set MEM_EXPR to the original decl, i.e. to PARM,
2966 instead of the copy of decl, i.e. FNARGS. */
2967 if (DECL_INCOMING_RTL (parm) && MEM_P (DECL_INCOMING_RTL (parm)))
2968 set_mem_expr (DECL_INCOMING_RTL (parm), parm);
2971 fnargs = TREE_CHAIN (fnargs);
2975 /* Assign RTL expressions to the function's parameters. This may involve
2976 copying them into registers and using those registers as the DECL_RTL. */
2979 assign_parms (tree fndecl)
2981 struct assign_parm_data_all all;
2984 current_function_internal_arg_pointer
2985 = targetm.calls.internal_arg_pointer ();
2987 assign_parms_initialize_all (&all);
2988 fnargs = assign_parms_augmented_arg_list (&all);
2990 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
2992 struct assign_parm_data_one data;
2994 /* Extract the type of PARM; adjust it according to ABI. */
2995 assign_parm_find_data_types (&all, parm, &data);
2997 /* Early out for errors and void parameters. */
2998 if (data.passed_mode == VOIDmode)
3000 SET_DECL_RTL (parm, const0_rtx);
3001 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
3005 if (current_function_stdarg && !TREE_CHAIN (parm))
3006 assign_parms_setup_varargs (&all, &data, false);
3008 /* Find out where the parameter arrives in this function. */
3009 assign_parm_find_entry_rtl (&all, &data);
3011 /* Find out where stack space for this parameter might be. */
3012 if (assign_parm_is_stack_parm (&all, &data))
3014 assign_parm_find_stack_rtl (parm, &data);
3015 assign_parm_adjust_entry_rtl (&data);
3018 /* Record permanently how this parm was passed. */
3019 set_decl_incoming_rtl (parm, data.entry_parm, data.passed_pointer);
3021 /* Update info on where next arg arrives in registers. */
3022 FUNCTION_ARG_ADVANCE (all.args_so_far, data.promoted_mode,
3023 data.passed_type, data.named_arg);
3025 assign_parm_adjust_stack_rtl (&data);
3027 if (assign_parm_setup_block_p (&data))
3028 assign_parm_setup_block (&all, parm, &data);
3029 else if (data.passed_pointer || use_register_for_decl (parm))
3030 assign_parm_setup_reg (&all, parm, &data);
3032 assign_parm_setup_stack (&all, parm, &data);
3035 if (targetm.calls.split_complex_arg && fnargs != all.orig_fnargs)
3036 assign_parms_unsplit_complex (&all, fnargs);
3038 /* Output all parameter conversion instructions (possibly including calls)
3039 now that all parameters have been copied out of hard registers. */
3040 emit_insn (all.first_conversion_insn);
3042 /* If we are receiving a struct value address as the first argument, set up
3043 the RTL for the function result. As this might require code to convert
3044 the transmitted address to Pmode, we do this here to ensure that possible
3045 preliminary conversions of the address have been emitted already. */
3046 if (all.function_result_decl)
3048 tree result = DECL_RESULT (current_function_decl);
3049 rtx addr = DECL_RTL (all.function_result_decl);
3052 if (DECL_BY_REFERENCE (result))
3056 addr = convert_memory_address (Pmode, addr);
3057 x = gen_rtx_MEM (DECL_MODE (result), addr);
3058 set_mem_attributes (x, result, 1);
3060 SET_DECL_RTL (result, x);
3063 /* We have aligned all the args, so add space for the pretend args. */
3064 current_function_pretend_args_size = all.pretend_args_size;
3065 all.stack_args_size.constant += all.extra_pretend_bytes;
3066 current_function_args_size = all.stack_args_size.constant;
3068 /* Adjust function incoming argument size for alignment and
3071 #ifdef REG_PARM_STACK_SPACE
3072 current_function_args_size = MAX (current_function_args_size,
3073 REG_PARM_STACK_SPACE (fndecl));
3076 current_function_args_size = CEIL_ROUND (current_function_args_size,
3077 PARM_BOUNDARY / BITS_PER_UNIT);
3079 #ifdef ARGS_GROW_DOWNWARD
3080 current_function_arg_offset_rtx
3081 = (all.stack_args_size.var == 0 ? GEN_INT (-all.stack_args_size.constant)
3082 : expand_expr (size_diffop (all.stack_args_size.var,
3083 size_int (-all.stack_args_size.constant)),
3084 NULL_RTX, VOIDmode, 0));
3086 current_function_arg_offset_rtx = ARGS_SIZE_RTX (all.stack_args_size);
3089 /* See how many bytes, if any, of its args a function should try to pop
3092 current_function_pops_args = RETURN_POPS_ARGS (fndecl, TREE_TYPE (fndecl),
3093 current_function_args_size);
3095 /* For stdarg.h function, save info about
3096 regs and stack space used by the named args. */
3098 current_function_args_info = all.args_so_far;
3100 /* Set the rtx used for the function return value. Put this in its
3101 own variable so any optimizers that need this information don't have
3102 to include tree.h. Do this here so it gets done when an inlined
3103 function gets output. */
3105 current_function_return_rtx
3106 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
3107 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
3109 /* If scalar return value was computed in a pseudo-reg, or was a named
3110 return value that got dumped to the stack, copy that to the hard
3112 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
3114 tree decl_result = DECL_RESULT (fndecl);
3115 rtx decl_rtl = DECL_RTL (decl_result);
3117 if (REG_P (decl_rtl)
3118 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
3119 : DECL_REGISTER (decl_result))
3123 real_decl_rtl = targetm.calls.function_value (TREE_TYPE (decl_result),
3125 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
3126 /* The delay slot scheduler assumes that current_function_return_rtx
3127 holds the hard register containing the return value, not a
3128 temporary pseudo. */
3129 current_function_return_rtx = real_decl_rtl;
3134 /* A subroutine of gimplify_parameters, invoked via walk_tree.
3135 For all seen types, gimplify their sizes. */
3138 gimplify_parm_type (tree *tp, int *walk_subtrees, void *data)
3145 if (POINTER_TYPE_P (t))
3147 else if (TYPE_SIZE (t) && !TREE_CONSTANT (TYPE_SIZE (t))
3148 && !TYPE_SIZES_GIMPLIFIED (t))
3150 gimplify_type_sizes (t, (tree *) data);
3158 /* Gimplify the parameter list for current_function_decl. This involves
3159 evaluating SAVE_EXPRs of variable sized parameters and generating code
3160 to implement callee-copies reference parameters. Returns a list of
3161 statements to add to the beginning of the function, or NULL if nothing
3165 gimplify_parameters (void)
3167 struct assign_parm_data_all all;
3168 tree fnargs, parm, stmts = NULL;
3170 assign_parms_initialize_all (&all);
3171 fnargs = assign_parms_augmented_arg_list (&all);
3173 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
3175 struct assign_parm_data_one data;
3177 /* Extract the type of PARM; adjust it according to ABI. */
3178 assign_parm_find_data_types (&all, parm, &data);
3180 /* Early out for errors and void parameters. */
3181 if (data.passed_mode == VOIDmode || DECL_SIZE (parm) == NULL)
3184 /* Update info on where next arg arrives in registers. */
3185 FUNCTION_ARG_ADVANCE (all.args_so_far, data.promoted_mode,
3186 data.passed_type, data.named_arg);
3188 /* ??? Once upon a time variable_size stuffed parameter list
3189 SAVE_EXPRs (amongst others) onto a pending sizes list. This
3190 turned out to be less than manageable in the gimple world.
3191 Now we have to hunt them down ourselves. */
3192 walk_tree_without_duplicates (&data.passed_type,
3193 gimplify_parm_type, &stmts);
3195 if (!TREE_CONSTANT (DECL_SIZE (parm)))
3197 gimplify_one_sizepos (&DECL_SIZE (parm), &stmts);
3198 gimplify_one_sizepos (&DECL_SIZE_UNIT (parm), &stmts);
3201 if (data.passed_pointer)
3203 tree type = TREE_TYPE (data.passed_type);
3204 if (reference_callee_copied (&all.args_so_far, TYPE_MODE (type),
3205 type, data.named_arg))
3209 /* For constant sized objects, this is trivial; for
3210 variable-sized objects, we have to play games. */
3211 if (TREE_CONSTANT (DECL_SIZE (parm)))
3213 local = create_tmp_var (type, get_name (parm));
3214 DECL_IGNORED_P (local) = 0;
3218 tree ptr_type, addr;
3220 ptr_type = build_pointer_type (type);
3221 addr = create_tmp_var (ptr_type, get_name (parm));
3222 DECL_IGNORED_P (addr) = 0;
3223 local = build_fold_indirect_ref (addr);
3225 t = built_in_decls[BUILT_IN_ALLOCA];
3226 t = build_call_expr (t, 1, DECL_SIZE_UNIT (parm));
3227 t = fold_convert (ptr_type, t);
3228 t = build_gimple_modify_stmt (addr, t);
3229 gimplify_and_add (t, &stmts);
3232 t = build_gimple_modify_stmt (local, parm);
3233 gimplify_and_add (t, &stmts);
3235 SET_DECL_VALUE_EXPR (parm, local);
3236 DECL_HAS_VALUE_EXPR_P (parm) = 1;
3244 /* Compute the size and offset from the start of the stacked arguments for a
3245 parm passed in mode PASSED_MODE and with type TYPE.
3247 INITIAL_OFFSET_PTR points to the current offset into the stacked
3250 The starting offset and size for this parm are returned in
3251 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
3252 nonzero, the offset is that of stack slot, which is returned in
3253 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
3254 padding required from the initial offset ptr to the stack slot.
3256 IN_REGS is nonzero if the argument will be passed in registers. It will
3257 never be set if REG_PARM_STACK_SPACE is not defined.
3259 FNDECL is the function in which the argument was defined.
3261 There are two types of rounding that are done. The first, controlled by
3262 FUNCTION_ARG_BOUNDARY, forces the offset from the start of the argument
3263 list to be aligned to the specific boundary (in bits). This rounding
3264 affects the initial and starting offsets, but not the argument size.
3266 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
3267 optionally rounds the size of the parm to PARM_BOUNDARY. The
3268 initial offset is not affected by this rounding, while the size always
3269 is and the starting offset may be. */
3271 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
3272 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
3273 callers pass in the total size of args so far as
3274 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
3277 locate_and_pad_parm (enum machine_mode passed_mode, tree type, int in_regs,
3278 int partial, tree fndecl ATTRIBUTE_UNUSED,
3279 struct args_size *initial_offset_ptr,
3280 struct locate_and_pad_arg_data *locate)
3283 enum direction where_pad;
3284 unsigned int boundary;
3285 int reg_parm_stack_space = 0;
3286 int part_size_in_regs;
3288 #ifdef REG_PARM_STACK_SPACE
3289 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
3291 /* If we have found a stack parm before we reach the end of the
3292 area reserved for registers, skip that area. */
3295 if (reg_parm_stack_space > 0)
3297 if (initial_offset_ptr->var)
3299 initial_offset_ptr->var
3300 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
3301 ssize_int (reg_parm_stack_space));
3302 initial_offset_ptr->constant = 0;
3304 else if (initial_offset_ptr->constant < reg_parm_stack_space)
3305 initial_offset_ptr->constant = reg_parm_stack_space;
3308 #endif /* REG_PARM_STACK_SPACE */
3310 part_size_in_regs = (reg_parm_stack_space == 0 ? partial : 0);
3313 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
3314 where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
3315 boundary = FUNCTION_ARG_BOUNDARY (passed_mode, type);
3316 locate->where_pad = where_pad;
3317 locate->boundary = boundary;
3319 /* Remember if the outgoing parameter requires extra alignment on the
3320 calling function side. */
3321 if (boundary > PREFERRED_STACK_BOUNDARY)
3322 boundary = PREFERRED_STACK_BOUNDARY;
3323 if (cfun->stack_alignment_needed < boundary)
3324 cfun->stack_alignment_needed = boundary;
3326 #ifdef ARGS_GROW_DOWNWARD
3327 locate->slot_offset.constant = -initial_offset_ptr->constant;
3328 if (initial_offset_ptr->var)
3329 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
3330 initial_offset_ptr->var);
3334 if (where_pad != none
3335 && (!host_integerp (sizetree, 1)
3336 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
3337 s2 = round_up (s2, PARM_BOUNDARY / BITS_PER_UNIT);
3338 SUB_PARM_SIZE (locate->slot_offset, s2);
3341 locate->slot_offset.constant += part_size_in_regs;
3344 #ifdef REG_PARM_STACK_SPACE
3345 || REG_PARM_STACK_SPACE (fndecl) > 0
3348 pad_to_arg_alignment (&locate->slot_offset, boundary,
3349 &locate->alignment_pad);
3351 locate->size.constant = (-initial_offset_ptr->constant
3352 - locate->slot_offset.constant);
3353 if (initial_offset_ptr->var)
3354 locate->size.var = size_binop (MINUS_EXPR,
3355 size_binop (MINUS_EXPR,
3357 initial_offset_ptr->var),
3358 locate->slot_offset.var);
3360 /* Pad_below needs the pre-rounded size to know how much to pad
3362 locate->offset = locate->slot_offset;
3363 if (where_pad == downward)
3364 pad_below (&locate->offset, passed_mode, sizetree);
3366 #else /* !ARGS_GROW_DOWNWARD */
3368 #ifdef REG_PARM_STACK_SPACE
3369 || REG_PARM_STACK_SPACE (fndecl) > 0
3372 pad_to_arg_alignment (initial_offset_ptr, boundary,
3373 &locate->alignment_pad);
3374 locate->slot_offset = *initial_offset_ptr;
3376 #ifdef PUSH_ROUNDING
3377 if (passed_mode != BLKmode)
3378 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
3381 /* Pad_below needs the pre-rounded size to know how much to pad below
3382 so this must be done before rounding up. */
3383 locate->offset = locate->slot_offset;
3384 if (where_pad == downward)
3385 pad_below (&locate->offset, passed_mode, sizetree);
3387 if (where_pad != none
3388 && (!host_integerp (sizetree, 1)
3389 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
3390 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3392 ADD_PARM_SIZE (locate->size, sizetree);
3394 locate->size.constant -= part_size_in_regs;
3395 #endif /* ARGS_GROW_DOWNWARD */
3398 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
3399 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
3402 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
3403 struct args_size *alignment_pad)
3405 tree save_var = NULL_TREE;
3406 HOST_WIDE_INT save_constant = 0;
3407 int boundary_in_bytes = boundary / BITS_PER_UNIT;
3408 HOST_WIDE_INT sp_offset = STACK_POINTER_OFFSET;
3410 #ifdef SPARC_STACK_BOUNDARY_HACK
3411 /* ??? The SPARC port may claim a STACK_BOUNDARY higher than
3412 the real alignment of %sp. However, when it does this, the
3413 alignment of %sp+STACK_POINTER_OFFSET is STACK_BOUNDARY. */
3414 if (SPARC_STACK_BOUNDARY_HACK)
3418 if (boundary > PARM_BOUNDARY)
3420 save_var = offset_ptr->var;
3421 save_constant = offset_ptr->constant;
3424 alignment_pad->var = NULL_TREE;
3425 alignment_pad->constant = 0;
3427 if (boundary > BITS_PER_UNIT)
3429 if (offset_ptr->var)
3431 tree sp_offset_tree = ssize_int (sp_offset);
3432 tree offset = size_binop (PLUS_EXPR,
3433 ARGS_SIZE_TREE (*offset_ptr),
3435 #ifdef ARGS_GROW_DOWNWARD
3436 tree rounded = round_down (offset, boundary / BITS_PER_UNIT);
3438 tree rounded = round_up (offset, boundary / BITS_PER_UNIT);
3441 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
3442 /* ARGS_SIZE_TREE includes constant term. */
3443 offset_ptr->constant = 0;
3444 if (boundary > PARM_BOUNDARY)
3445 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
3450 offset_ptr->constant = -sp_offset +
3451 #ifdef ARGS_GROW_DOWNWARD
3452 FLOOR_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
3454 CEIL_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
3456 if (boundary > PARM_BOUNDARY)
3457 alignment_pad->constant = offset_ptr->constant - save_constant;
3463 pad_below (struct args_size *offset_ptr, enum machine_mode passed_mode, tree sizetree)
3465 if (passed_mode != BLKmode)
3467 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
3468 offset_ptr->constant
3469 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
3470 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
3471 - GET_MODE_SIZE (passed_mode));
3475 if (TREE_CODE (sizetree) != INTEGER_CST
3476 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
3478 /* Round the size up to multiple of PARM_BOUNDARY bits. */
3479 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3481 ADD_PARM_SIZE (*offset_ptr, s2);
3482 SUB_PARM_SIZE (*offset_ptr, sizetree);
3488 /* True if register REGNO was alive at a place where `setjmp' was
3489 called and was set more than once or is an argument. Such regs may
3490 be clobbered by `longjmp'. */
3493 regno_clobbered_at_setjmp (bitmap setjmp_crosses, int regno)
3495 /* There appear to be cases where some local vars never reach the
3496 backend but have bogus regnos. */
3497 if (regno >= max_reg_num ())
3500 return ((REG_N_SETS (regno) > 1
3501 || REGNO_REG_SET_P (df_get_live_out (ENTRY_BLOCK_PTR), regno))
3502 && REGNO_REG_SET_P (setjmp_crosses, regno));
3505 /* Walk the tree of blocks describing the binding levels within a
3506 function and warn about variables the might be killed by setjmp or
3507 vfork. This is done after calling flow_analysis before register
3508 allocation since that will clobber the pseudo-regs to hard
3512 setjmp_vars_warning (bitmap setjmp_crosses, tree block)
3516 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
3518 if (TREE_CODE (decl) == VAR_DECL
3519 && DECL_RTL_SET_P (decl)
3520 && REG_P (DECL_RTL (decl))
3521 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
3522 warning (OPT_Wclobbered, "variable %q+D might be clobbered by"
3523 " %<longjmp%> or %<vfork%>", decl);
3526 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = BLOCK_CHAIN (sub))
3527 setjmp_vars_warning (setjmp_crosses, sub);
3530 /* Do the appropriate part of setjmp_vars_warning
3531 but for arguments instead of local variables. */
3534 setjmp_args_warning (bitmap setjmp_crosses)
3537 for (decl = DECL_ARGUMENTS (current_function_decl);
3538 decl; decl = TREE_CHAIN (decl))
3539 if (DECL_RTL (decl) != 0
3540 && REG_P (DECL_RTL (decl))
3541 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
3542 warning (OPT_Wclobbered,
3543 "argument %q+D might be clobbered by %<longjmp%> or %<vfork%>",
3547 /* Generate warning messages for variables live across setjmp. */
3550 generate_setjmp_warnings (void)
3552 bitmap setjmp_crosses = regstat_get_setjmp_crosses ();
3554 if (n_basic_blocks == NUM_FIXED_BLOCKS
3555 || bitmap_empty_p (setjmp_crosses))
3558 setjmp_vars_warning (setjmp_crosses, DECL_INITIAL (current_function_decl));
3559 setjmp_args_warning (setjmp_crosses);
3563 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
3564 and create duplicate blocks. */
3565 /* ??? Need an option to either create block fragments or to create
3566 abstract origin duplicates of a source block. It really depends
3567 on what optimization has been performed. */
3570 reorder_blocks (void)
3572 tree block = DECL_INITIAL (current_function_decl);
3573 VEC(tree,heap) *block_stack;
3575 if (block == NULL_TREE)
3578 block_stack = VEC_alloc (tree, heap, 10);
3580 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
3581 clear_block_marks (block);
3583 /* Prune the old trees away, so that they don't get in the way. */
3584 BLOCK_SUBBLOCKS (block) = NULL_TREE;
3585 BLOCK_CHAIN (block) = NULL_TREE;
3587 /* Recreate the block tree from the note nesting. */
3588 reorder_blocks_1 (get_insns (), block, &block_stack);
3589 BLOCK_SUBBLOCKS (block) = blocks_nreverse (BLOCK_SUBBLOCKS (block));
3591 VEC_free (tree, heap, block_stack);
3594 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
3597 clear_block_marks (tree block)
3601 TREE_ASM_WRITTEN (block) = 0;
3602 clear_block_marks (BLOCK_SUBBLOCKS (block));
3603 block = BLOCK_CHAIN (block);
3608 reorder_blocks_1 (rtx insns, tree current_block, VEC(tree,heap) **p_block_stack)
3612 for (insn = insns; insn; insn = NEXT_INSN (insn))
3616 if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_BEG)
3618 tree block = NOTE_BLOCK (insn);
3621 origin = (BLOCK_FRAGMENT_ORIGIN (block)
3622 ? BLOCK_FRAGMENT_ORIGIN (block)
3625 /* If we have seen this block before, that means it now
3626 spans multiple address regions. Create a new fragment. */
3627 if (TREE_ASM_WRITTEN (block))
3629 tree new_block = copy_node (block);
3631 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
3632 BLOCK_FRAGMENT_CHAIN (new_block)
3633 = BLOCK_FRAGMENT_CHAIN (origin);
3634 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
3636 NOTE_BLOCK (insn) = new_block;
3640 BLOCK_SUBBLOCKS (block) = 0;
3641 TREE_ASM_WRITTEN (block) = 1;
3642 /* When there's only one block for the entire function,
3643 current_block == block and we mustn't do this, it
3644 will cause infinite recursion. */
3645 if (block != current_block)
3647 if (block != origin)
3648 gcc_assert (BLOCK_SUPERCONTEXT (origin) == current_block);
3650 BLOCK_SUPERCONTEXT (block) = current_block;
3651 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
3652 BLOCK_SUBBLOCKS (current_block) = block;
3653 current_block = origin;
3655 VEC_safe_push (tree, heap, *p_block_stack, block);
3657 else if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_END)
3659 NOTE_BLOCK (insn) = VEC_pop (tree, *p_block_stack);
3660 BLOCK_SUBBLOCKS (current_block)
3661 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block));
3662 current_block = BLOCK_SUPERCONTEXT (current_block);
3668 /* Reverse the order of elements in the chain T of blocks,
3669 and return the new head of the chain (old last element). */
3672 blocks_nreverse (tree t)
3674 tree prev = 0, decl, next;
3675 for (decl = t; decl; decl = next)
3677 next = BLOCK_CHAIN (decl);
3678 BLOCK_CHAIN (decl) = prev;
3684 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
3685 non-NULL, list them all into VECTOR, in a depth-first preorder
3686 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
3690 all_blocks (tree block, tree *vector)
3696 TREE_ASM_WRITTEN (block) = 0;
3698 /* Record this block. */
3700 vector[n_blocks] = block;
3704 /* Record the subblocks, and their subblocks... */
3705 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
3706 vector ? vector + n_blocks : 0);
3707 block = BLOCK_CHAIN (block);
3713 /* Return a vector containing all the blocks rooted at BLOCK. The
3714 number of elements in the vector is stored in N_BLOCKS_P. The
3715 vector is dynamically allocated; it is the caller's responsibility
3716 to call `free' on the pointer returned. */
3719 get_block_vector (tree block, int *n_blocks_p)
3723 *n_blocks_p = all_blocks (block, NULL);
3724 block_vector = XNEWVEC (tree, *n_blocks_p);
3725 all_blocks (block, block_vector);
3727 return block_vector;
3730 static GTY(()) int next_block_index = 2;
3732 /* Set BLOCK_NUMBER for all the blocks in FN. */
3735 number_blocks (tree fn)
3741 /* For SDB and XCOFF debugging output, we start numbering the blocks
3742 from 1 within each function, rather than keeping a running
3744 #if defined (SDB_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
3745 if (write_symbols == SDB_DEBUG || write_symbols == XCOFF_DEBUG)
3746 next_block_index = 1;
3749 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
3751 /* The top-level BLOCK isn't numbered at all. */
3752 for (i = 1; i < n_blocks; ++i)
3753 /* We number the blocks from two. */
3754 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
3756 free (block_vector);
3761 /* If VAR is present in a subblock of BLOCK, return the subblock. */
3764 debug_find_var_in_block_tree (tree var, tree block)
3768 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
3772 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
3774 tree ret = debug_find_var_in_block_tree (var, t);
3782 /* Keep track of whether we're in a dummy function context. If we are,
3783 we don't want to invoke the set_current_function hook, because we'll
3784 get into trouble if the hook calls target_reinit () recursively or
3785 when the initial initialization is not yet complete. */
3787 static bool in_dummy_function;
3789 /* Invoke the target hook when setting cfun. */
3792 invoke_set_current_function_hook (tree fndecl)
3794 if (!in_dummy_function)
3795 targetm.set_current_function (fndecl);
3798 /* cfun should never be set directly; use this function. */
3801 set_cfun (struct function *new_cfun)
3803 if (cfun != new_cfun)
3806 invoke_set_current_function_hook (new_cfun ? new_cfun->decl : NULL_TREE);
3810 /* Keep track of the cfun stack. */
3812 typedef struct function *function_p;
3814 DEF_VEC_P(function_p);
3815 DEF_VEC_ALLOC_P(function_p,heap);
3817 /* Initialized with NOGC, making this poisonous to the garbage collector. */
3819 static VEC(function_p,heap) *cfun_stack;
3821 /* We save the value of in_system_header here when pushing the first
3822 function on the cfun stack, and we restore it from here when
3823 popping the last function. */
3825 static bool saved_in_system_header;
3827 /* Push the current cfun onto the stack, and set cfun to new_cfun. */
3830 push_cfun (struct function *new_cfun)
3833 saved_in_system_header = in_system_header;
3834 VEC_safe_push (function_p, heap, cfun_stack, cfun);
3836 in_system_header = DECL_IN_SYSTEM_HEADER (new_cfun->decl);
3837 set_cfun (new_cfun);
3840 /* Pop cfun from the stack. */
3845 struct function *new_cfun = VEC_pop (function_p, cfun_stack);
3846 in_system_header = ((new_cfun == NULL) ? saved_in_system_header
3847 : DECL_IN_SYSTEM_HEADER (new_cfun->decl));
3848 set_cfun (new_cfun);
3851 /* Return value of funcdef and increase it. */
3853 get_next_funcdef_no (void)
3855 return funcdef_no++;
3858 /* Allocate a function structure for FNDECL and set its contents
3859 to the defaults. Set cfun to the newly-allocated object.
3860 Some of the helper functions invoked during initialization assume
3861 that cfun has already been set. Therefore, assign the new object
3862 directly into cfun and invoke the back end hook explicitly at the
3863 very end, rather than initializing a temporary and calling set_cfun
3866 ABSTRACT_P is true if this is a function that will never be seen by
3867 the middle-end. Such functions are front-end concepts (like C++
3868 function templates) that do not correspond directly to functions
3869 placed in object files. */
3872 allocate_struct_function (tree fndecl, bool abstract_p)
3875 tree fntype = fndecl ? TREE_TYPE (fndecl) : NULL_TREE;
3877 cfun = ggc_alloc_cleared (sizeof (struct function));
3879 cfun->stack_alignment_needed = STACK_BOUNDARY;
3880 cfun->preferred_stack_boundary = STACK_BOUNDARY;
3882 current_function_funcdef_no = get_next_funcdef_no ();
3884 cfun->function_frequency = FUNCTION_FREQUENCY_NORMAL;
3886 init_eh_for_function ();
3888 lang_hooks.function.init (cfun);
3889 if (init_machine_status)
3890 cfun->machine = (*init_machine_status) ();
3894 DECL_STRUCT_FUNCTION (fndecl) = cfun;
3895 cfun->decl = fndecl;
3897 result = DECL_RESULT (fndecl);
3898 if (!abstract_p && aggregate_value_p (result, fndecl))
3900 #ifdef PCC_STATIC_STRUCT_RETURN
3901 current_function_returns_pcc_struct = 1;
3903 current_function_returns_struct = 1;
3906 current_function_stdarg
3908 && TYPE_ARG_TYPES (fntype) != 0
3909 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
3910 != void_type_node));
3912 /* Assume all registers in stdarg functions need to be saved. */
3913 cfun->va_list_gpr_size = VA_LIST_MAX_GPR_SIZE;
3914 cfun->va_list_fpr_size = VA_LIST_MAX_FPR_SIZE;
3917 invoke_set_current_function_hook (fndecl);
3920 /* This is like allocate_struct_function, but pushes a new cfun for FNDECL
3921 instead of just setting it. */
3924 push_struct_function (tree fndecl)
3927 saved_in_system_header = in_system_header;
3928 VEC_safe_push (function_p, heap, cfun_stack, cfun);
3930 in_system_header = DECL_IN_SYSTEM_HEADER (fndecl);
3931 allocate_struct_function (fndecl, false);
3934 /* Reset cfun, and other non-struct-function variables to defaults as
3935 appropriate for emitting rtl at the start of a function. */
3938 prepare_function_start (void)
3940 gcc_assert (!rtl.emit.x_last_insn);
3942 init_varasm_status ();
3945 cse_not_expected = ! optimize;
3947 /* Caller save not needed yet. */
3948 caller_save_needed = 0;
3950 /* We haven't done register allocation yet. */
3953 /* Indicate that we have not instantiated virtual registers yet. */
3954 virtuals_instantiated = 0;
3956 /* Indicate that we want CONCATs now. */
3957 generating_concat_p = 1;
3959 /* Indicate we have no need of a frame pointer yet. */
3960 frame_pointer_needed = 0;
3963 /* Initialize the rtl expansion mechanism so that we can do simple things
3964 like generate sequences. This is used to provide a context during global
3965 initialization of some passes. You must call expand_dummy_function_end
3966 to exit this context. */
3969 init_dummy_function_start (void)
3971 gcc_assert (!in_dummy_function);
3972 in_dummy_function = true;
3973 push_struct_function (NULL_TREE);
3974 prepare_function_start ();
3977 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
3978 and initialize static variables for generating RTL for the statements
3982 init_function_start (tree subr)
3984 if (subr && DECL_STRUCT_FUNCTION (subr))
3985 set_cfun (DECL_STRUCT_FUNCTION (subr));
3987 allocate_struct_function (subr, false);
3988 prepare_function_start ();
3990 /* Warn if this value is an aggregate type,
3991 regardless of which calling convention we are using for it. */
3992 if (AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
3993 warning (OPT_Waggregate_return, "function returns an aggregate");
3996 /* Make sure all values used by the optimization passes have sane
3999 init_function_for_compilation (void)
4003 /* No prologue/epilogue insns yet. Make sure that these vectors are
4005 gcc_assert (VEC_length (int, prologue) == 0);
4006 gcc_assert (VEC_length (int, epilogue) == 0);
4007 gcc_assert (VEC_length (int, sibcall_epilogue) == 0);
4011 struct rtl_opt_pass pass_init_function =
4017 init_function_for_compilation, /* execute */
4020 0, /* static_pass_number */
4022 0, /* properties_required */
4023 0, /* properties_provided */
4024 0, /* properties_destroyed */
4025 0, /* todo_flags_start */
4026 0 /* todo_flags_finish */
4032 expand_main_function (void)
4034 #if (defined(INVOKE__main) \
4035 || (!defined(HAS_INIT_SECTION) \
4036 && !defined(INIT_SECTION_ASM_OP) \
4037 && !defined(INIT_ARRAY_SECTION_ASM_OP)))
4038 emit_library_call (init_one_libfunc (NAME__MAIN), LCT_NORMAL, VOIDmode, 0);
4042 /* Expand code to initialize the stack_protect_guard. This is invoked at
4043 the beginning of a function to be protected. */
4045 #ifndef HAVE_stack_protect_set
4046 # define HAVE_stack_protect_set 0
4047 # define gen_stack_protect_set(x,y) (gcc_unreachable (), NULL_RTX)
4051 stack_protect_prologue (void)
4053 tree guard_decl = targetm.stack_protect_guard ();
4056 /* Avoid expand_expr here, because we don't want guard_decl pulled
4057 into registers unless absolutely necessary. And we know that
4058 cfun->stack_protect_guard is a local stack slot, so this skips
4060 x = validize_mem (DECL_RTL (cfun->stack_protect_guard));
4061 y = validize_mem (DECL_RTL (guard_decl));
4063 /* Allow the target to copy from Y to X without leaking Y into a
4065 if (HAVE_stack_protect_set)
4067 rtx insn = gen_stack_protect_set (x, y);
4075 /* Otherwise do a straight move. */
4076 emit_move_insn (x, y);
4079 /* Expand code to verify the stack_protect_guard. This is invoked at
4080 the end of a function to be protected. */
4082 #ifndef HAVE_stack_protect_test
4083 # define HAVE_stack_protect_test 0
4084 # define gen_stack_protect_test(x, y, z) (gcc_unreachable (), NULL_RTX)
4088 stack_protect_epilogue (void)
4090 tree guard_decl = targetm.stack_protect_guard ();
4091 rtx label = gen_label_rtx ();
4094 /* Avoid expand_expr here, because we don't want guard_decl pulled
4095 into registers unless absolutely necessary. And we know that
4096 cfun->stack_protect_guard is a local stack slot, so this skips
4098 x = validize_mem (DECL_RTL (cfun->stack_protect_guard));
4099 y = validize_mem (DECL_RTL (guard_decl));
4101 /* Allow the target to compare Y with X without leaking either into
4103 switch (HAVE_stack_protect_test != 0)
4106 tmp = gen_stack_protect_test (x, y, label);
4115 emit_cmp_and_jump_insns (x, y, EQ, NULL_RTX, ptr_mode, 1, label);
4119 /* The noreturn predictor has been moved to the tree level. The rtl-level
4120 predictors estimate this branch about 20%, which isn't enough to get
4121 things moved out of line. Since this is the only extant case of adding
4122 a noreturn function at the rtl level, it doesn't seem worth doing ought
4123 except adding the prediction by hand. */
4124 tmp = get_last_insn ();
4126 predict_insn_def (tmp, PRED_NORETURN, TAKEN);
4128 expand_expr_stmt (targetm.stack_protect_fail ());
4132 /* Start the RTL for a new function, and set variables used for
4134 SUBR is the FUNCTION_DECL node.
4135 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
4136 the function's parameters, which must be run at any return statement. */
4139 expand_function_start (tree subr)
4141 /* Make sure volatile mem refs aren't considered
4142 valid operands of arithmetic insns. */
4143 init_recog_no_volatile ();
4145 current_function_profile
4147 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
4149 current_function_limit_stack
4150 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
4152 /* Make the label for return statements to jump to. Do not special
4153 case machines with special return instructions -- they will be
4154 handled later during jump, ifcvt, or epilogue creation. */
4155 return_label = gen_label_rtx ();
4157 /* Initialize rtx used to return the value. */
4158 /* Do this before assign_parms so that we copy the struct value address
4159 before any library calls that assign parms might generate. */
4161 /* Decide whether to return the value in memory or in a register. */
4162 if (aggregate_value_p (DECL_RESULT (subr), subr))
4164 /* Returning something that won't go in a register. */
4165 rtx value_address = 0;
4167 #ifdef PCC_STATIC_STRUCT_RETURN
4168 if (current_function_returns_pcc_struct)
4170 int size = int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr)));
4171 value_address = assemble_static_space (size);
4176 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 2);
4177 /* Expect to be passed the address of a place to store the value.
4178 If it is passed as an argument, assign_parms will take care of
4182 value_address = gen_reg_rtx (Pmode);
4183 emit_move_insn (value_address, sv);
4188 rtx x = value_address;
4189 if (!DECL_BY_REFERENCE (DECL_RESULT (subr)))
4191 x = gen_rtx_MEM (DECL_MODE (DECL_RESULT (subr)), x);
4192 set_mem_attributes (x, DECL_RESULT (subr), 1);
4194 SET_DECL_RTL (DECL_RESULT (subr), x);
4197 else if (DECL_MODE (DECL_RESULT (subr)) == VOIDmode)
4198 /* If return mode is void, this decl rtl should not be used. */
4199 SET_DECL_RTL (DECL_RESULT (subr), NULL_RTX);
4202 /* Compute the return values into a pseudo reg, which we will copy
4203 into the true return register after the cleanups are done. */
4204 tree return_type = TREE_TYPE (DECL_RESULT (subr));
4205 if (TYPE_MODE (return_type) != BLKmode
4206 && targetm.calls.return_in_msb (return_type))
4207 /* expand_function_end will insert the appropriate padding in
4208 this case. Use the return value's natural (unpadded) mode
4209 within the function proper. */
4210 SET_DECL_RTL (DECL_RESULT (subr),
4211 gen_reg_rtx (TYPE_MODE (return_type)));
4214 /* In order to figure out what mode to use for the pseudo, we
4215 figure out what the mode of the eventual return register will
4216 actually be, and use that. */
4217 rtx hard_reg = hard_function_value (return_type, subr, 0, 1);
4219 /* Structures that are returned in registers are not
4220 aggregate_value_p, so we may see a PARALLEL or a REG. */
4221 if (REG_P (hard_reg))
4222 SET_DECL_RTL (DECL_RESULT (subr),
4223 gen_reg_rtx (GET_MODE (hard_reg)));
4226 gcc_assert (GET_CODE (hard_reg) == PARALLEL);
4227 SET_DECL_RTL (DECL_RESULT (subr), gen_group_rtx (hard_reg));
4231 /* Set DECL_REGISTER flag so that expand_function_end will copy the
4232 result to the real return register(s). */
4233 DECL_REGISTER (DECL_RESULT (subr)) = 1;
4236 /* Initialize rtx for parameters and local variables.
4237 In some cases this requires emitting insns. */
4238 assign_parms (subr);
4240 /* If function gets a static chain arg, store it. */
4241 if (cfun->static_chain_decl)
4243 tree parm = cfun->static_chain_decl;
4244 rtx local = gen_reg_rtx (Pmode);
4246 set_decl_incoming_rtl (parm, static_chain_incoming_rtx, false);
4247 SET_DECL_RTL (parm, local);
4248 mark_reg_pointer (local, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
4250 emit_move_insn (local, static_chain_incoming_rtx);
4253 /* If the function receives a non-local goto, then store the
4254 bits we need to restore the frame pointer. */
4255 if (cfun->nonlocal_goto_save_area)
4260 /* ??? We need to do this save early. Unfortunately here is
4261 before the frame variable gets declared. Help out... */
4262 tree var = TREE_OPERAND (cfun->nonlocal_goto_save_area, 0);
4263 if (!DECL_RTL_SET_P (var))
4266 t_save = build4 (ARRAY_REF, ptr_type_node,
4267 cfun->nonlocal_goto_save_area,
4268 integer_zero_node, NULL_TREE, NULL_TREE);
4269 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
4270 r_save = convert_memory_address (Pmode, r_save);
4272 emit_move_insn (r_save, virtual_stack_vars_rtx);
4273 update_nonlocal_goto_save_area ();
4276 /* The following was moved from init_function_start.
4277 The move is supposed to make sdb output more accurate. */
4278 /* Indicate the beginning of the function body,
4279 as opposed to parm setup. */
4280 emit_note (NOTE_INSN_FUNCTION_BEG);
4282 gcc_assert (NOTE_P (get_last_insn ()));
4284 parm_birth_insn = get_last_insn ();
4286 if (current_function_profile)
4289 PROFILE_HOOK (current_function_funcdef_no);
4293 /* After the display initializations is where the stack checking
4295 if(flag_stack_check)
4296 stack_check_probe_note = emit_note (NOTE_INSN_DELETED);
4298 /* Make sure there is a line number after the function entry setup code. */
4299 force_next_line_note ();
4302 /* Undo the effects of init_dummy_function_start. */
4304 expand_dummy_function_end (void)
4306 gcc_assert (in_dummy_function);
4308 /* End any sequences that failed to be closed due to syntax errors. */
4309 while (in_sequence_p ())
4312 /* Outside function body, can't compute type's actual size
4313 until next function's body starts. */
4315 free_after_parsing (cfun);
4316 free_after_compilation (cfun);
4318 in_dummy_function = false;
4321 /* Call DOIT for each hard register used as a return value from
4322 the current function. */
4325 diddle_return_value (void (*doit) (rtx, void *), void *arg)
4327 rtx outgoing = current_function_return_rtx;
4332 if (REG_P (outgoing))
4333 (*doit) (outgoing, arg);
4334 else if (GET_CODE (outgoing) == PARALLEL)
4338 for (i = 0; i < XVECLEN (outgoing, 0); i++)
4340 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
4342 if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
4349 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
4351 emit_insn (gen_rtx_CLOBBER (VOIDmode, reg));
4355 clobber_return_register (void)
4357 diddle_return_value (do_clobber_return_reg, NULL);
4359 /* In case we do use pseudo to return value, clobber it too. */
4360 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
4362 tree decl_result = DECL_RESULT (current_function_decl);
4363 rtx decl_rtl = DECL_RTL (decl_result);
4364 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
4366 do_clobber_return_reg (decl_rtl, NULL);
4372 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
4374 emit_insn (gen_rtx_USE (VOIDmode, reg));
4378 use_return_register (void)
4380 diddle_return_value (do_use_return_reg, NULL);
4383 /* Possibly warn about unused parameters. */
4385 do_warn_unused_parameter (tree fn)
4389 for (decl = DECL_ARGUMENTS (fn);
4390 decl; decl = TREE_CHAIN (decl))
4391 if (!TREE_USED (decl) && TREE_CODE (decl) == PARM_DECL
4392 && DECL_NAME (decl) && !DECL_ARTIFICIAL (decl)
4393 && !TREE_NO_WARNING (decl))
4394 warning (OPT_Wunused_parameter, "unused parameter %q+D", decl);
4397 static GTY(()) rtx initial_trampoline;
4399 /* Generate RTL for the end of the current function. */
4402 expand_function_end (void)
4406 /* If arg_pointer_save_area was referenced only from a nested
4407 function, we will not have initialized it yet. Do that now. */
4408 if (arg_pointer_save_area && ! cfun->arg_pointer_save_area_init)
4409 get_arg_pointer_save_area ();
4411 /* If we are doing stack checking and this function makes calls,
4412 do a stack probe at the start of the function to ensure we have enough
4413 space for another stack frame. */
4414 if (flag_stack_check && ! STACK_CHECK_BUILTIN)
4418 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
4422 probe_stack_range (STACK_CHECK_PROTECT,
4423 GEN_INT (STACK_CHECK_MAX_FRAME_SIZE));
4426 emit_insn_before (seq, stack_check_probe_note);
4431 /* End any sequences that failed to be closed due to syntax errors. */
4432 while (in_sequence_p ())
4435 clear_pending_stack_adjust ();
4436 do_pending_stack_adjust ();
4438 /* Output a linenumber for the end of the function.
4439 SDB depends on this. */
4440 force_next_line_note ();
4441 set_curr_insn_source_location (input_location);
4443 /* Before the return label (if any), clobber the return
4444 registers so that they are not propagated live to the rest of
4445 the function. This can only happen with functions that drop
4446 through; if there had been a return statement, there would
4447 have either been a return rtx, or a jump to the return label.
4449 We delay actual code generation after the current_function_value_rtx
4451 clobber_after = get_last_insn ();
4453 /* Output the label for the actual return from the function. */
4454 emit_label (return_label);
4456 if (USING_SJLJ_EXCEPTIONS)
4458 /* Let except.c know where it should emit the call to unregister
4459 the function context for sjlj exceptions. */
4460 if (flag_exceptions)
4461 sjlj_emit_function_exit_after (get_last_insn ());
4465 /* We want to ensure that instructions that may trap are not
4466 moved into the epilogue by scheduling, because we don't
4467 always emit unwind information for the epilogue. */
4468 if (flag_non_call_exceptions)
4469 emit_insn (gen_blockage ());
4472 /* If this is an implementation of throw, do what's necessary to
4473 communicate between __builtin_eh_return and the epilogue. */
4474 expand_eh_return ();
4476 /* If scalar return value was computed in a pseudo-reg, or was a named
4477 return value that got dumped to the stack, copy that to the hard
4479 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
4481 tree decl_result = DECL_RESULT (current_function_decl);
4482 rtx decl_rtl = DECL_RTL (decl_result);
4484 if (REG_P (decl_rtl)
4485 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
4486 : DECL_REGISTER (decl_result))
4488 rtx real_decl_rtl = current_function_return_rtx;
4490 /* This should be set in assign_parms. */
4491 gcc_assert (REG_FUNCTION_VALUE_P (real_decl_rtl));
4493 /* If this is a BLKmode structure being returned in registers,
4494 then use the mode computed in expand_return. Note that if
4495 decl_rtl is memory, then its mode may have been changed,
4496 but that current_function_return_rtx has not. */
4497 if (GET_MODE (real_decl_rtl) == BLKmode)
4498 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
4500 /* If a non-BLKmode return value should be padded at the least
4501 significant end of the register, shift it left by the appropriate
4502 amount. BLKmode results are handled using the group load/store
4504 if (TYPE_MODE (TREE_TYPE (decl_result)) != BLKmode
4505 && targetm.calls.return_in_msb (TREE_TYPE (decl_result)))
4507 emit_move_insn (gen_rtx_REG (GET_MODE (decl_rtl),
4508 REGNO (real_decl_rtl)),
4510 shift_return_value (GET_MODE (decl_rtl), true, real_decl_rtl);
4512 /* If a named return value dumped decl_return to memory, then
4513 we may need to re-do the PROMOTE_MODE signed/unsigned
4515 else if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
4517 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
4519 if (targetm.calls.promote_function_return (TREE_TYPE (current_function_decl)))
4520 promote_mode (TREE_TYPE (decl_result), GET_MODE (decl_rtl),
4523 convert_move (real_decl_rtl, decl_rtl, unsignedp);
4525 else if (GET_CODE (real_decl_rtl) == PARALLEL)
4527 /* If expand_function_start has created a PARALLEL for decl_rtl,
4528 move the result to the real return registers. Otherwise, do
4529 a group load from decl_rtl for a named return. */
4530 if (GET_CODE (decl_rtl) == PARALLEL)
4531 emit_group_move (real_decl_rtl, decl_rtl);
4533 emit_group_load (real_decl_rtl, decl_rtl,
4534 TREE_TYPE (decl_result),
4535 int_size_in_bytes (TREE_TYPE (decl_result)));
4537 /* In the case of complex integer modes smaller than a word, we'll
4538 need to generate some non-trivial bitfield insertions. Do that
4539 on a pseudo and not the hard register. */
4540 else if (GET_CODE (decl_rtl) == CONCAT
4541 && GET_MODE_CLASS (GET_MODE (decl_rtl)) == MODE_COMPLEX_INT
4542 && GET_MODE_BITSIZE (GET_MODE (decl_rtl)) <= BITS_PER_WORD)
4544 int old_generating_concat_p;
4547 old_generating_concat_p = generating_concat_p;
4548 generating_concat_p = 0;
4549 tmp = gen_reg_rtx (GET_MODE (decl_rtl));
4550 generating_concat_p = old_generating_concat_p;
4552 emit_move_insn (tmp, decl_rtl);
4553 emit_move_insn (real_decl_rtl, tmp);
4556 emit_move_insn (real_decl_rtl, decl_rtl);
4560 /* If returning a structure, arrange to return the address of the value
4561 in a place where debuggers expect to find it.
4563 If returning a structure PCC style,
4564 the caller also depends on this value.
4565 And current_function_returns_pcc_struct is not necessarily set. */
4566 if (current_function_returns_struct
4567 || current_function_returns_pcc_struct)
4569 rtx value_address = DECL_RTL (DECL_RESULT (current_function_decl));
4570 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
4573 if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
4574 type = TREE_TYPE (type);
4576 value_address = XEXP (value_address, 0);
4578 outgoing = targetm.calls.function_value (build_pointer_type (type),
4579 current_function_decl, true);
4581 /* Mark this as a function return value so integrate will delete the
4582 assignment and USE below when inlining this function. */
4583 REG_FUNCTION_VALUE_P (outgoing) = 1;
4585 /* The address may be ptr_mode and OUTGOING may be Pmode. */
4586 value_address = convert_memory_address (GET_MODE (outgoing),
4589 emit_move_insn (outgoing, value_address);
4591 /* Show return register used to hold result (in this case the address
4593 current_function_return_rtx = outgoing;
4596 /* Emit the actual code to clobber return register. */
4601 clobber_return_register ();
4602 expand_naked_return ();
4606 emit_insn_after (seq, clobber_after);
4609 /* Output the label for the naked return from the function. */
4610 emit_label (naked_return_label);
4612 /* @@@ This is a kludge. We want to ensure that instructions that
4613 may trap are not moved into the epilogue by scheduling, because
4614 we don't always emit unwind information for the epilogue. */
4615 if (! USING_SJLJ_EXCEPTIONS && flag_non_call_exceptions)
4616 emit_insn (gen_blockage ());
4618 /* If stack protection is enabled for this function, check the guard. */
4619 if (cfun->stack_protect_guard)
4620 stack_protect_epilogue ();
4622 /* If we had calls to alloca, and this machine needs
4623 an accurate stack pointer to exit the function,
4624 insert some code to save and restore the stack pointer. */
4625 if (! EXIT_IGNORE_STACK
4626 && current_function_calls_alloca)
4630 emit_stack_save (SAVE_FUNCTION, &tem, parm_birth_insn);
4631 emit_stack_restore (SAVE_FUNCTION, tem, NULL_RTX);
4634 /* ??? This should no longer be necessary since stupid is no longer with
4635 us, but there are some parts of the compiler (eg reload_combine, and
4636 sh mach_dep_reorg) that still try and compute their own lifetime info
4637 instead of using the general framework. */
4638 use_return_register ();
4642 get_arg_pointer_save_area (void)
4644 rtx ret = arg_pointer_save_area;
4648 ret = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
4649 arg_pointer_save_area = ret;
4652 if (! cfun->arg_pointer_save_area_init)
4656 /* Save the arg pointer at the beginning of the function. The
4657 generated stack slot may not be a valid memory address, so we
4658 have to check it and fix it if necessary. */
4660 emit_move_insn (validize_mem (ret), virtual_incoming_args_rtx);
4664 push_topmost_sequence ();
4665 emit_insn_after (seq, entry_of_function ());
4666 pop_topmost_sequence ();
4672 /* Extend a vector that records the INSN_UIDs of INSNS
4673 (a list of one or more insns). */
4676 record_insns (rtx insns, VEC(int,heap) **vecp)
4680 for (tmp = insns; tmp != NULL_RTX; tmp = NEXT_INSN (tmp))
4681 VEC_safe_push (int, heap, *vecp, INSN_UID (tmp));
4684 /* Set the locator of the insn chain starting at INSN to LOC. */
4686 set_insn_locators (rtx insn, int loc)
4688 while (insn != NULL_RTX)
4691 INSN_LOCATOR (insn) = loc;
4692 insn = NEXT_INSN (insn);
4696 /* Determine how many INSN_UIDs in VEC are part of INSN. Because we can
4697 be running after reorg, SEQUENCE rtl is possible. */
4700 contains (const_rtx insn, VEC(int,heap) **vec)
4704 if (NONJUMP_INSN_P (insn)
4705 && GET_CODE (PATTERN (insn)) == SEQUENCE)
4708 for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
4709 for (j = VEC_length (int, *vec) - 1; j >= 0; --j)
4710 if (INSN_UID (XVECEXP (PATTERN (insn), 0, i))
4711 == VEC_index (int, *vec, j))
4717 for (j = VEC_length (int, *vec) - 1; j >= 0; --j)
4718 if (INSN_UID (insn) == VEC_index (int, *vec, j))
4725 prologue_epilogue_contains (const_rtx insn)
4727 if (contains (insn, &prologue))
4729 if (contains (insn, &epilogue))
4735 sibcall_epilogue_contains (const_rtx insn)
4737 if (sibcall_epilogue)
4738 return contains (insn, &sibcall_epilogue);
4743 /* Insert gen_return at the end of block BB. This also means updating
4744 block_for_insn appropriately. */
4747 emit_return_into_block (basic_block bb)
4749 emit_jump_insn_after (gen_return (), BB_END (bb));
4751 #endif /* HAVE_return */
4753 #if defined(HAVE_epilogue) && defined(INCOMING_RETURN_ADDR_RTX)
4755 /* These functions convert the epilogue into a variant that does not
4756 modify the stack pointer. This is used in cases where a function
4757 returns an object whose size is not known until it is computed.
4758 The called function leaves the object on the stack, leaves the
4759 stack depressed, and returns a pointer to the object.
4761 What we need to do is track all modifications and references to the
4762 stack pointer, deleting the modifications and changing the
4763 references to point to the location the stack pointer would have
4764 pointed to had the modifications taken place.
4766 These functions need to be portable so we need to make as few
4767 assumptions about the epilogue as we can. However, the epilogue
4768 basically contains three things: instructions to reset the stack
4769 pointer, instructions to reload registers, possibly including the
4770 frame pointer, and an instruction to return to the caller.
4772 We must be sure of what a relevant epilogue insn is doing. We also
4773 make no attempt to validate the insns we make since if they are
4774 invalid, we probably can't do anything valid. The intent is that
4775 these routines get "smarter" as more and more machines start to use
4776 them and they try operating on different epilogues.
4778 We use the following structure to track what the part of the
4779 epilogue that we've already processed has done. We keep two copies
4780 of the SP equivalence, one for use during the insn we are
4781 processing and one for use in the next insn. The difference is
4782 because one part of a PARALLEL may adjust SP and the other may use
4787 rtx sp_equiv_reg; /* REG that SP is set from, perhaps SP. */
4788 HOST_WIDE_INT sp_offset; /* Offset from SP_EQUIV_REG of present SP. */
4789 rtx new_sp_equiv_reg; /* REG to be used at end of insn. */
4790 HOST_WIDE_INT new_sp_offset; /* Offset to be used at end of insn. */
4791 rtx equiv_reg_src; /* If nonzero, the value that SP_EQUIV_REG
4792 should be set to once we no longer need
4794 rtx const_equiv[FIRST_PSEUDO_REGISTER]; /* Any known constant equivalences
4798 static void handle_epilogue_set (rtx, struct epi_info *);
4799 static void update_epilogue_consts (rtx, const_rtx, void *);
4800 static void emit_equiv_load (struct epi_info *);
4802 /* Modify INSN, a list of one or more insns that is part of the epilogue, to
4803 no modifications to the stack pointer. Return the new list of insns. */
4806 keep_stack_depressed (rtx insns)
4809 struct epi_info info;
4812 /* If the epilogue is just a single instruction, it must be OK as is. */
4813 if (NEXT_INSN (insns) == NULL_RTX)
4816 /* Otherwise, start a sequence, initialize the information we have, and
4817 process all the insns we were given. */
4820 info.sp_equiv_reg = stack_pointer_rtx;
4822 info.equiv_reg_src = 0;
4824 for (j = 0; j < FIRST_PSEUDO_REGISTER; j++)
4825 info.const_equiv[j] = 0;
4829 while (insn != NULL_RTX)
4831 next = NEXT_INSN (insn);
4840 /* If this insn references the register that SP is equivalent to and
4841 we have a pending load to that register, we must force out the load
4842 first and then indicate we no longer know what SP's equivalent is. */
4843 if (info.equiv_reg_src != 0
4844 && reg_referenced_p (info.sp_equiv_reg, PATTERN (insn)))
4846 emit_equiv_load (&info);
4847 info.sp_equiv_reg = 0;
4850 info.new_sp_equiv_reg = info.sp_equiv_reg;
4851 info.new_sp_offset = info.sp_offset;
4853 /* If this is a (RETURN) and the return address is on the stack,
4854 update the address and change to an indirect jump. */
4855 if (GET_CODE (PATTERN (insn)) == RETURN
4856 || (GET_CODE (PATTERN (insn)) == PARALLEL
4857 && GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == RETURN))
4859 rtx retaddr = INCOMING_RETURN_ADDR_RTX;
4861 HOST_WIDE_INT offset = 0;
4862 rtx jump_insn, jump_set;
4864 /* If the return address is in a register, we can emit the insn
4865 unchanged. Otherwise, it must be a MEM and we see what the
4866 base register and offset are. In any case, we have to emit any
4867 pending load to the equivalent reg of SP, if any. */
4868 if (REG_P (retaddr))
4870 emit_equiv_load (&info);
4878 gcc_assert (MEM_P (retaddr));
4880 ret_ptr = XEXP (retaddr, 0);
4882 if (REG_P (ret_ptr))
4884 base = gen_rtx_REG (Pmode, REGNO (ret_ptr));
4889 gcc_assert (GET_CODE (ret_ptr) == PLUS
4890 && REG_P (XEXP (ret_ptr, 0))
4891 && GET_CODE (XEXP (ret_ptr, 1)) == CONST_INT);
4892 base = gen_rtx_REG (Pmode, REGNO (XEXP (ret_ptr, 0)));
4893 offset = INTVAL (XEXP (ret_ptr, 1));
4897 /* If the base of the location containing the return pointer
4898 is SP, we must update it with the replacement address. Otherwise,
4899 just build the necessary MEM. */
4900 retaddr = plus_constant (base, offset);
4901 if (base == stack_pointer_rtx)
4902 retaddr = simplify_replace_rtx (retaddr, stack_pointer_rtx,
4903 plus_constant (info.sp_equiv_reg,
4906 retaddr = gen_rtx_MEM (Pmode, retaddr);
4907 MEM_NOTRAP_P (retaddr) = 1;
4909 /* If there is a pending load to the equivalent register for SP
4910 and we reference that register, we must load our address into
4911 a scratch register and then do that load. */
4912 if (info.equiv_reg_src
4913 && reg_overlap_mentioned_p (info.equiv_reg_src, retaddr))
4918 for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
4919 if (HARD_REGNO_MODE_OK (regno, Pmode)
4920 && !fixed_regs[regno]
4921 && TEST_HARD_REG_BIT (regs_invalidated_by_call, regno)
4923 (DF_LR_IN (EXIT_BLOCK_PTR), regno)
4924 && !refers_to_regno_p (regno,
4925 end_hard_regno (Pmode, regno),
4926 info.equiv_reg_src, NULL)
4927 && info.const_equiv[regno] == 0)
4930 gcc_assert (regno < FIRST_PSEUDO_REGISTER);
4932 reg = gen_rtx_REG (Pmode, regno);
4933 emit_move_insn (reg, retaddr);
4937 emit_equiv_load (&info);
4938 jump_insn = emit_jump_insn (gen_indirect_jump (retaddr));
4940 /* Show the SET in the above insn is a RETURN. */
4941 jump_set = single_set (jump_insn);
4942 gcc_assert (jump_set);
4943 SET_IS_RETURN_P (jump_set) = 1;
4946 /* If SP is not mentioned in the pattern and its equivalent register, if
4947 any, is not modified, just emit it. Otherwise, if neither is set,
4948 replace the reference to SP and emit the insn. If none of those are
4949 true, handle each SET individually. */
4950 else if (!reg_mentioned_p (stack_pointer_rtx, PATTERN (insn))
4951 && (info.sp_equiv_reg == stack_pointer_rtx
4952 || !reg_set_p (info.sp_equiv_reg, insn)))
4954 else if (! reg_set_p (stack_pointer_rtx, insn)
4955 && (info.sp_equiv_reg == stack_pointer_rtx
4956 || !reg_set_p (info.sp_equiv_reg, insn)))
4960 changed = validate_replace_rtx (stack_pointer_rtx,
4961 plus_constant (info.sp_equiv_reg,
4964 gcc_assert (changed);
4968 else if (GET_CODE (PATTERN (insn)) == SET)
4969 handle_epilogue_set (PATTERN (insn), &info);
4970 else if (GET_CODE (PATTERN (insn)) == PARALLEL)
4972 for (j = 0; j < XVECLEN (PATTERN (insn), 0); j++)
4973 if (GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == SET)
4974 handle_epilogue_set (XVECEXP (PATTERN (insn), 0, j), &info);
4979 info.sp_equiv_reg = info.new_sp_equiv_reg;
4980 info.sp_offset = info.new_sp_offset;
4982 /* Now update any constants this insn sets. */
4983 note_stores (PATTERN (insn), update_epilogue_consts, &info);
4987 insns = get_insns ();
4992 /* SET is a SET from an insn in the epilogue. P is a pointer to the epi_info
4993 structure that contains information about what we've seen so far. We
4994 process this SET by either updating that data or by emitting one or
4998 handle_epilogue_set (rtx set, struct epi_info *p)
5000 /* First handle the case where we are setting SP. Record what it is being
5001 set from, which we must be able to determine */
5002 if (reg_set_p (stack_pointer_rtx, set))
5004 gcc_assert (SET_DEST (set) == stack_pointer_rtx);
5006 if (GET_CODE (SET_SRC (set)) == PLUS)
5008 p->new_sp_equiv_reg = XEXP (SET_SRC (set), 0);
5009 if (GET_CODE (XEXP (SET_SRC (set), 1)) == CONST_INT)
5010 p->new_sp_offset = INTVAL (XEXP (SET_SRC (set), 1));
5013 gcc_assert (REG_P (XEXP (SET_SRC (set), 1))
5014 && (REGNO (XEXP (SET_SRC (set), 1))
5015 < FIRST_PSEUDO_REGISTER)
5016 && p->const_equiv[REGNO (XEXP (SET_SRC (set), 1))]);
5018 = INTVAL (p->const_equiv[REGNO (XEXP (SET_SRC (set), 1))]);
5022 p->new_sp_equiv_reg = SET_SRC (set), p->new_sp_offset = 0;
5024 /* If we are adjusting SP, we adjust from the old data. */
5025 if (p->new_sp_equiv_reg == stack_pointer_rtx)
5027 p->new_sp_equiv_reg = p->sp_equiv_reg;
5028 p->new_sp_offset += p->sp_offset;
5031 gcc_assert (p->new_sp_equiv_reg && REG_P (p->new_sp_equiv_reg));
5036 /* Next handle the case where we are setting SP's equivalent
5037 register. We must not already have a value to set it to. We
5038 could update, but there seems little point in handling that case.
5039 Note that we have to allow for the case where we are setting the
5040 register set in the previous part of a PARALLEL inside a single
5041 insn. But use the old offset for any updates within this insn.
5042 We must allow for the case where the register is being set in a
5043 different (usually wider) mode than Pmode). */
5044 else if (p->new_sp_equiv_reg != 0 && reg_set_p (p->new_sp_equiv_reg, set))
5046 gcc_assert (!p->equiv_reg_src
5047 && REG_P (p->new_sp_equiv_reg)
5048 && REG_P (SET_DEST (set))
5049 && (GET_MODE_BITSIZE (GET_MODE (SET_DEST (set)))
5051 && REGNO (p->new_sp_equiv_reg) == REGNO (SET_DEST (set)));
5053 = simplify_replace_rtx (SET_SRC (set), stack_pointer_rtx,
5054 plus_constant (p->sp_equiv_reg,
5058 /* Otherwise, replace any references to SP in the insn to its new value
5059 and emit the insn. */
5062 SET_SRC (set) = simplify_replace_rtx (SET_SRC (set), stack_pointer_rtx,
5063 plus_constant (p->sp_equiv_reg,
5065 SET_DEST (set) = simplify_replace_rtx (SET_DEST (set), stack_pointer_rtx,
5066 plus_constant (p->sp_equiv_reg,
5072 /* Update the tracking information for registers set to constants. */
5075 update_epilogue_consts (rtx dest, const_rtx x, void *data)
5077 struct epi_info *p = (struct epi_info *) data;
5080 if (!REG_P (dest) || REGNO (dest) >= FIRST_PSEUDO_REGISTER)
5083 /* If we are either clobbering a register or doing a partial set,
5084 show we don't know the value. */
5085 else if (GET_CODE (x) == CLOBBER || ! rtx_equal_p (dest, SET_DEST (x)))
5086 p->const_equiv[REGNO (dest)] = 0;
5088 /* If we are setting it to a constant, record that constant. */
5089 else if (GET_CODE (SET_SRC (x)) == CONST_INT)
5090 p->const_equiv[REGNO (dest)] = SET_SRC (x);
5092 /* If this is a binary operation between a register we have been tracking
5093 and a constant, see if we can compute a new constant value. */
5094 else if (ARITHMETIC_P (SET_SRC (x))
5095 && REG_P (XEXP (SET_SRC (x), 0))
5096 && REGNO (XEXP (SET_SRC (x), 0)) < FIRST_PSEUDO_REGISTER
5097 && p->const_equiv[REGNO (XEXP (SET_SRC (x), 0))] != 0
5098 && GET_CODE (XEXP (SET_SRC (x), 1)) == CONST_INT
5099 && 0 != (new = simplify_binary_operation
5100 (GET_CODE (SET_SRC (x)), GET_MODE (dest),
5101 p->const_equiv[REGNO (XEXP (SET_SRC (x), 0))],
5102 XEXP (SET_SRC (x), 1)))
5103 && GET_CODE (new) == CONST_INT)
5104 p->const_equiv[REGNO (dest)] = new;
5106 /* Otherwise, we can't do anything with this value. */
5108 p->const_equiv[REGNO (dest)] = 0;
5111 /* Emit an insn to do the load shown in p->equiv_reg_src, if needed. */
5114 emit_equiv_load (struct epi_info *p)
5116 if (p->equiv_reg_src != 0)
5118 rtx dest = p->sp_equiv_reg;
5120 if (GET_MODE (p->equiv_reg_src) != GET_MODE (dest))
5121 dest = gen_rtx_REG (GET_MODE (p->equiv_reg_src),
5122 REGNO (p->sp_equiv_reg));
5124 emit_move_insn (dest, p->equiv_reg_src);
5125 p->equiv_reg_src = 0;
5130 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
5131 this into place with notes indicating where the prologue ends and where
5132 the epilogue begins. Update the basic block information when possible. */
5135 thread_prologue_and_epilogue_insns (void)
5139 #if defined (HAVE_sibcall_epilogue) || defined (HAVE_epilogue) || defined (HAVE_return) || defined (HAVE_prologue)
5142 #if defined (HAVE_epilogue) || defined(HAVE_return)
5143 rtx epilogue_end = NULL_RTX;
5147 #ifdef HAVE_prologue
5151 seq = gen_prologue ();
5154 /* Insert an explicit USE for the frame pointer
5155 if the profiling is on and the frame pointer is required. */
5156 if (current_function_profile && frame_pointer_needed)
5157 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
5159 /* Retain a map of the prologue insns. */
5160 record_insns (seq, &prologue);
5161 emit_note (NOTE_INSN_PROLOGUE_END);
5163 #ifndef PROFILE_BEFORE_PROLOGUE
5164 /* Ensure that instructions are not moved into the prologue when
5165 profiling is on. The call to the profiling routine can be
5166 emitted within the live range of a call-clobbered register. */
5167 if (current_function_profile)
5168 emit_insn (gen_blockage ());
5173 set_insn_locators (seq, prologue_locator);
5175 /* Can't deal with multiple successors of the entry block
5176 at the moment. Function should always have at least one
5178 gcc_assert (single_succ_p (ENTRY_BLOCK_PTR));
5180 insert_insn_on_edge (seq, single_succ_edge (ENTRY_BLOCK_PTR));
5185 /* If the exit block has no non-fake predecessors, we don't need
5187 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5188 if ((e->flags & EDGE_FAKE) == 0)
5194 if (optimize && HAVE_return)
5196 /* If we're allowed to generate a simple return instruction,
5197 then by definition we don't need a full epilogue. Examine
5198 the block that falls through to EXIT. If it does not
5199 contain any code, examine its predecessors and try to
5200 emit (conditional) return instructions. */
5205 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5206 if (e->flags & EDGE_FALLTHRU)
5212 /* Verify that there are no active instructions in the last block. */
5213 label = BB_END (last);
5214 while (label && !LABEL_P (label))
5216 if (active_insn_p (label))
5218 label = PREV_INSN (label);
5221 if (BB_HEAD (last) == label && LABEL_P (label))
5225 for (ei2 = ei_start (last->preds); (e = ei_safe_edge (ei2)); )
5227 basic_block bb = e->src;
5230 if (bb == ENTRY_BLOCK_PTR)
5237 if (!JUMP_P (jump) || JUMP_LABEL (jump) != label)
5243 /* If we have an unconditional jump, we can replace that
5244 with a simple return instruction. */
5245 if (simplejump_p (jump))
5247 emit_return_into_block (bb);
5251 /* If we have a conditional jump, we can try to replace
5252 that with a conditional return instruction. */
5253 else if (condjump_p (jump))
5255 if (! redirect_jump (jump, 0, 0))
5261 /* If this block has only one successor, it both jumps
5262 and falls through to the fallthru block, so we can't
5264 if (single_succ_p (bb))
5276 /* Fix up the CFG for the successful change we just made. */
5277 redirect_edge_succ (e, EXIT_BLOCK_PTR);
5280 /* Emit a return insn for the exit fallthru block. Whether
5281 this is still reachable will be determined later. */
5283 emit_barrier_after (BB_END (last));
5284 emit_return_into_block (last);
5285 epilogue_end = BB_END (last);
5286 single_succ_edge (last)->flags &= ~EDGE_FALLTHRU;
5291 /* Find the edge that falls through to EXIT. Other edges may exist
5292 due to RETURN instructions, but those don't need epilogues.
5293 There really shouldn't be a mixture -- either all should have
5294 been converted or none, however... */
5296 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5297 if (e->flags & EDGE_FALLTHRU)
5302 #ifdef HAVE_epilogue
5306 epilogue_end = emit_note (NOTE_INSN_EPILOGUE_BEG);
5308 seq = gen_epilogue ();
5310 #ifdef INCOMING_RETURN_ADDR_RTX
5311 /* If this function returns with the stack depressed and we can support
5312 it, massage the epilogue to actually do that. */
5313 if (TREE_CODE (TREE_TYPE (current_function_decl)) == FUNCTION_TYPE
5314 && TYPE_RETURNS_STACK_DEPRESSED (TREE_TYPE (current_function_decl)))
5315 seq = keep_stack_depressed (seq);
5318 emit_jump_insn (seq);
5320 /* Retain a map of the epilogue insns. */
5321 record_insns (seq, &epilogue);
5322 set_insn_locators (seq, epilogue_locator);
5327 insert_insn_on_edge (seq, e);
5335 if (! next_active_insn (BB_END (e->src)))
5337 /* We have a fall-through edge to the exit block, the source is not
5338 at the end of the function, and there will be an assembler epilogue
5339 at the end of the function.
5340 We can't use force_nonfallthru here, because that would try to
5341 use return. Inserting a jump 'by hand' is extremely messy, so
5342 we take advantage of cfg_layout_finalize using
5343 fixup_fallthru_exit_predecessor. */
5344 cfg_layout_initialize (0);
5345 FOR_EACH_BB (cur_bb)
5346 if (cur_bb->index >= NUM_FIXED_BLOCKS
5347 && cur_bb->next_bb->index >= NUM_FIXED_BLOCKS)
5348 cur_bb->aux = cur_bb->next_bb;
5349 cfg_layout_finalize ();
5355 commit_edge_insertions ();
5357 /* The epilogue insns we inserted may cause the exit edge to no longer
5359 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5361 if (((e->flags & EDGE_FALLTHRU) != 0)
5362 && returnjump_p (BB_END (e->src)))
5363 e->flags &= ~EDGE_FALLTHRU;
5367 #ifdef HAVE_sibcall_epilogue
5368 /* Emit sibling epilogues before any sibling call sites. */
5369 for (ei = ei_start (EXIT_BLOCK_PTR->preds); (e = ei_safe_edge (ei)); )
5371 basic_block bb = e->src;
5372 rtx insn = BB_END (bb);
5375 || ! SIBLING_CALL_P (insn))
5382 emit_insn (gen_sibcall_epilogue ());
5386 /* Retain a map of the epilogue insns. Used in life analysis to
5387 avoid getting rid of sibcall epilogue insns. Do this before we
5388 actually emit the sequence. */
5389 record_insns (seq, &sibcall_epilogue);
5390 set_insn_locators (seq, epilogue_locator);
5392 emit_insn_before (seq, insn);
5397 #ifdef HAVE_epilogue
5402 /* Similarly, move any line notes that appear after the epilogue.
5403 There is no need, however, to be quite so anal about the existence
5404 of such a note. Also possibly move
5405 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
5407 for (insn = epilogue_end; insn; insn = next)
5409 next = NEXT_INSN (insn);
5411 && (NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG))
5412 reorder_insns (insn, insn, PREV_INSN (epilogue_end));
5417 /* Threading the prologue and epilogue changes the artificial refs
5418 in the entry and exit blocks. */
5419 epilogue_completed = 1;
5420 df_update_entry_exit_and_calls ();
5423 /* Reposition the prologue-end and epilogue-begin notes after instruction
5424 scheduling and delayed branch scheduling. */
5427 reposition_prologue_and_epilogue_notes (void)
5429 #if defined (HAVE_prologue) || defined (HAVE_epilogue)
5430 rtx insn, last, note;
5433 if ((len = VEC_length (int, prologue)) > 0)
5437 /* Scan from the beginning until we reach the last prologue insn.
5438 We apparently can't depend on basic_block_{head,end} after
5440 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
5444 if (NOTE_KIND (insn) == NOTE_INSN_PROLOGUE_END)
5447 else if (contains (insn, &prologue))
5457 /* Find the prologue-end note if we haven't already, and
5458 move it to just after the last prologue insn. */
5461 for (note = last; (note = NEXT_INSN (note));)
5463 && NOTE_KIND (note) == NOTE_INSN_PROLOGUE_END)
5467 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
5469 last = NEXT_INSN (last);
5470 reorder_insns (note, note, last);
5474 if ((len = VEC_length (int, epilogue)) > 0)
5478 /* Scan from the end until we reach the first epilogue insn.
5479 We apparently can't depend on basic_block_{head,end} after
5481 for (insn = get_last_insn (); insn; insn = PREV_INSN (insn))
5485 if (NOTE_KIND (insn) == NOTE_INSN_EPILOGUE_BEG)
5488 else if (contains (insn, &epilogue))
5498 /* Find the epilogue-begin note if we haven't already, and
5499 move it to just before the first epilogue insn. */
5502 for (note = insn; (note = PREV_INSN (note));)
5504 && NOTE_KIND (note) == NOTE_INSN_EPILOGUE_BEG)
5508 if (PREV_INSN (last) != note)
5509 reorder_insns (note, note, PREV_INSN (last));
5512 #endif /* HAVE_prologue or HAVE_epilogue */
5515 /* Returns the name of the current function. */
5517 current_function_name (void)
5519 return lang_hooks.decl_printable_name (cfun->decl, 2);
5522 /* Returns the raw (mangled) name of the current function. */
5524 current_function_assembler_name (void)
5526 return IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (cfun->decl));
5531 rest_of_handle_check_leaf_regs (void)
5533 #ifdef LEAF_REGISTERS
5534 current_function_uses_only_leaf_regs
5535 = optimize > 0 && only_leaf_regs_used () && leaf_function_p ();
5540 /* Insert a TYPE into the used types hash table of CFUN. */
5542 used_types_insert_helper (tree type, struct function *func)
5544 if (type != NULL && func != NULL)
5548 if (func->used_types_hash == NULL)
5549 func->used_types_hash = htab_create_ggc (37, htab_hash_pointer,
5550 htab_eq_pointer, NULL);
5551 slot = htab_find_slot (func->used_types_hash, type, INSERT);
5557 /* Given a type, insert it into the used hash table in cfun. */
5559 used_types_insert (tree t)
5561 while (POINTER_TYPE_P (t) || TREE_CODE (t) == ARRAY_TYPE)
5563 t = TYPE_MAIN_VARIANT (t);
5564 if (debug_info_level > DINFO_LEVEL_NONE)
5565 used_types_insert_helper (t, cfun);
5568 struct rtl_opt_pass pass_leaf_regs =
5574 rest_of_handle_check_leaf_regs, /* execute */
5577 0, /* static_pass_number */
5579 0, /* properties_required */
5580 0, /* properties_provided */
5581 0, /* properties_destroyed */
5582 0, /* todo_flags_start */
5583 0 /* todo_flags_finish */
5588 rest_of_handle_thread_prologue_and_epilogue (void)
5591 cleanup_cfg (CLEANUP_EXPENSIVE);
5592 /* On some machines, the prologue and epilogue code, or parts thereof,
5593 can be represented as RTL. Doing so lets us schedule insns between
5594 it and the rest of the code and also allows delayed branch
5595 scheduling to operate in the epilogue. */
5597 thread_prologue_and_epilogue_insns ();
5601 struct rtl_opt_pass pass_thread_prologue_and_epilogue =
5605 "pro_and_epilogue", /* name */
5607 rest_of_handle_thread_prologue_and_epilogue, /* execute */
5610 0, /* static_pass_number */
5611 TV_THREAD_PROLOGUE_AND_EPILOGUE, /* tv_id */
5612 0, /* properties_required */
5613 0, /* properties_provided */
5614 0, /* properties_destroyed */
5615 TODO_verify_flow, /* todo_flags_start */
5618 TODO_df_finish | TODO_verify_rtl_sharing |
5619 TODO_ggc_collect /* todo_flags_finish */
5624 /* This mini-pass fixes fall-out from SSA in asm statements that have
5625 in-out constraints. Say you start with
5628 asm ("": "+mr" (inout));
5631 which is transformed very early to use explicit output and match operands:
5634 asm ("": "=mr" (inout) : "0" (inout));
5637 Or, after SSA and copyprop,
5639 asm ("": "=mr" (inout_2) : "0" (inout_1));
5642 Clearly inout_2 and inout_1 can't be coalesced easily anymore, as
5643 they represent two separate values, so they will get different pseudo
5644 registers during expansion. Then, since the two operands need to match
5645 per the constraints, but use different pseudo registers, reload can
5646 only register a reload for these operands. But reloads can only be
5647 satisfied by hardregs, not by memory, so we need a register for this
5648 reload, just because we are presented with non-matching operands.
5649 So, even though we allow memory for this operand, no memory can be
5650 used for it, just because the two operands don't match. This can
5651 cause reload failures on register-starved targets.
5653 So it's a symptom of reload not being able to use memory for reloads
5654 or, alternatively it's also a symptom of both operands not coming into
5655 reload as matching (in which case the pseudo could go to memory just
5656 fine, as the alternative allows it, and no reload would be necessary).
5657 We fix the latter problem here, by transforming
5659 asm ("": "=mr" (inout_2) : "0" (inout_1));
5664 asm ("": "=mr" (inout_2) : "0" (inout_2)); */
5667 match_asm_constraints_1 (rtx insn, rtx *p_sets, int noutputs)
5670 bool changed = false;
5671 rtx op = SET_SRC (p_sets[0]);
5672 int ninputs = ASM_OPERANDS_INPUT_LENGTH (op);
5673 rtvec inputs = ASM_OPERANDS_INPUT_VEC (op);
5674 bool *output_matched = alloca (noutputs * sizeof (bool));
5676 memset (output_matched, 0, noutputs * sizeof (bool));
5677 for (i = 0; i < ninputs; i++)
5679 rtx input, output, insns;
5680 const char *constraint = ASM_OPERANDS_INPUT_CONSTRAINT (op, i);
5684 match = strtoul (constraint, &end, 10);
5685 if (end == constraint)
5688 gcc_assert (match < noutputs);
5689 output = SET_DEST (p_sets[match]);
5690 input = RTVEC_ELT (inputs, i);
5691 /* Only do the transformation for pseudos. */
5692 if (! REG_P (output)
5693 || rtx_equal_p (output, input)
5694 || (GET_MODE (input) != VOIDmode
5695 && GET_MODE (input) != GET_MODE (output)))
5698 /* We can't do anything if the output is also used as input,
5699 as we're going to overwrite it. */
5700 for (j = 0; j < ninputs; j++)
5701 if (reg_overlap_mentioned_p (output, RTVEC_ELT (inputs, j)))
5706 /* Avoid changing the same input several times. For
5707 asm ("" : "=mr" (out1), "=mr" (out2) : "0" (in), "1" (in));
5708 only change in once (to out1), rather than changing it
5709 first to out1 and afterwards to out2. */
5712 for (j = 0; j < noutputs; j++)
5713 if (output_matched[j] && input == SET_DEST (p_sets[j]))
5718 output_matched[match] = true;
5721 emit_move_insn (output, input);
5722 insns = get_insns ();
5724 emit_insn_before (insns, insn);
5726 /* Now replace all mentions of the input with output. We can't
5727 just replace the occurence in inputs[i], as the register might
5728 also be used in some other input (or even in an address of an
5729 output), which would mean possibly increasing the number of
5730 inputs by one (namely 'output' in addition), which might pose
5731 a too complicated problem for reload to solve. E.g. this situation:
5733 asm ("" : "=r" (output), "=m" (input) : "0" (input))
5735 Here 'input' is used in two occurrences as input (once for the
5736 input operand, once for the address in the second output operand).
5737 If we would replace only the occurence of the input operand (to
5738 make the matching) we would be left with this:
5741 asm ("" : "=r" (output), "=m" (input) : "0" (output))
5743 Now we suddenly have two different input values (containing the same
5744 value, but different pseudos) where we formerly had only one.
5745 With more complicated asms this might lead to reload failures
5746 which wouldn't have happen without this pass. So, iterate over
5747 all operands and replace all occurrences of the register used. */
5748 for (j = 0; j < noutputs; j++)
5749 if (!rtx_equal_p (SET_DEST (p_sets[j]), input)
5750 && reg_overlap_mentioned_p (input, SET_DEST (p_sets[j])))
5751 SET_DEST (p_sets[j]) = replace_rtx (SET_DEST (p_sets[j]),
5753 for (j = 0; j < ninputs; j++)
5754 if (reg_overlap_mentioned_p (input, RTVEC_ELT (inputs, j)))
5755 RTVEC_ELT (inputs, j) = replace_rtx (RTVEC_ELT (inputs, j),
5762 df_insn_rescan (insn);
5766 rest_of_match_asm_constraints (void)
5769 rtx insn, pat, *p_sets;
5772 if (!cfun->has_asm_statement)
5775 df_set_flags (DF_DEFER_INSN_RESCAN);
5778 FOR_BB_INSNS (bb, insn)
5783 pat = PATTERN (insn);
5784 if (GET_CODE (pat) == PARALLEL)
5785 p_sets = &XVECEXP (pat, 0, 0), noutputs = XVECLEN (pat, 0);
5786 else if (GET_CODE (pat) == SET)
5787 p_sets = &PATTERN (insn), noutputs = 1;
5791 if (GET_CODE (*p_sets) == SET
5792 && GET_CODE (SET_SRC (*p_sets)) == ASM_OPERANDS)
5793 match_asm_constraints_1 (insn, p_sets, noutputs);
5797 return TODO_df_finish;
5800 struct rtl_opt_pass pass_match_asm_constraints =
5804 "asmcons", /* name */
5806 rest_of_match_asm_constraints, /* execute */
5809 0, /* static_pass_number */
5811 0, /* properties_required */
5812 0, /* properties_provided */
5813 0, /* properties_destroyed */
5814 0, /* todo_flags_start */
5815 TODO_dump_func /* todo_flags_finish */
5820 #include "gt-function.h"