1 /* Expands front end tree to back end RTL for GCC.
2 Copyright (C) 1987, 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* This file handles the generation of rtl code from tree structure
23 at the level of the function as a whole.
24 It creates the rtl expressions for parameters and auto variables
25 and has full responsibility for allocating stack slots.
27 `expand_function_start' is called at the beginning of a function,
28 before the function body is parsed, and `expand_function_end' is
29 called after parsing the body.
31 Call `assign_stack_local' to allocate a stack slot for a local variable.
32 This is usually done during the RTL generation for the function body,
33 but it can also be done in the reload pass when a pseudo-register does
34 not get a hard register. */
38 #include "coretypes.h"
49 #include "hard-reg-set.h"
50 #include "insn-config.h"
53 #include "basic-block.h"
58 #include "integrate.h"
59 #include "langhooks.h"
61 #include "cfglayout.h"
63 #include "tree-pass.h"
69 /* So we can assign to cfun in this file. */
72 #ifndef STACK_ALIGNMENT_NEEDED
73 #define STACK_ALIGNMENT_NEEDED 1
76 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
78 /* Some systems use __main in a way incompatible with its use in gcc, in these
79 cases use the macros NAME__MAIN to give a quoted symbol and SYMBOL__MAIN to
80 give the same symbol without quotes for an alternative entry point. You
81 must define both, or neither. */
83 #define NAME__MAIN "__main"
86 /* Round a value to the lowest integer less than it that is a multiple of
87 the required alignment. Avoid using division in case the value is
88 negative. Assume the alignment is a power of two. */
89 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
91 /* Similar, but round to the next highest integer that meets the
93 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
95 /* Nonzero if function being compiled doesn't contain any calls
96 (ignoring the prologue and epilogue). This is set prior to
97 local register allocation and is valid for the remaining
99 int current_function_is_leaf;
101 /* Nonzero if function being compiled doesn't modify the stack pointer
102 (ignoring the prologue and epilogue). This is only valid after
103 pass_stack_ptr_mod has run. */
104 int current_function_sp_is_unchanging;
106 /* Nonzero if the function being compiled is a leaf function which only
107 uses leaf registers. This is valid after reload (specifically after
108 sched2) and is useful only if the port defines LEAF_REGISTERS. */
109 int current_function_uses_only_leaf_regs;
111 /* Nonzero once virtual register instantiation has been done.
112 assign_stack_local uses frame_pointer_rtx when this is nonzero.
113 calls.c:emit_library_call_value_1 uses it to set up
114 post-instantiation libcalls. */
115 int virtuals_instantiated;
117 /* Assign unique numbers to labels generated for profiling, debugging, etc. */
118 static GTY(()) int funcdef_no;
120 /* These variables hold pointers to functions to create and destroy
121 target specific, per-function data structures. */
122 struct machine_function * (*init_machine_status) (void);
124 /* The currently compiled function. */
125 struct function *cfun = 0;
127 /* These arrays record the INSN_UIDs of the prologue and epilogue insns. */
128 static VEC(int,heap) *prologue;
129 static VEC(int,heap) *epilogue;
131 /* Array of INSN_UIDs to hold the INSN_UIDs for each sibcall epilogue
133 static VEC(int,heap) *sibcall_epilogue;
135 /* In order to evaluate some expressions, such as function calls returning
136 structures in memory, we need to temporarily allocate stack locations.
137 We record each allocated temporary in the following structure.
139 Associated with each temporary slot is a nesting level. When we pop up
140 one level, all temporaries associated with the previous level are freed.
141 Normally, all temporaries are freed after the execution of the statement
142 in which they were created. However, if we are inside a ({...}) grouping,
143 the result may be in a temporary and hence must be preserved. If the
144 result could be in a temporary, we preserve it if we can determine which
145 one it is in. If we cannot determine which temporary may contain the
146 result, all temporaries are preserved. A temporary is preserved by
147 pretending it was allocated at the previous nesting level.
149 Automatic variables are also assigned temporary slots, at the nesting
150 level where they are defined. They are marked a "kept" so that
151 free_temp_slots will not free them. */
153 struct temp_slot GTY(())
155 /* Points to next temporary slot. */
156 struct temp_slot *next;
157 /* Points to previous temporary slot. */
158 struct temp_slot *prev;
160 /* The rtx to used to reference the slot. */
162 /* The rtx used to represent the address if not the address of the
163 slot above. May be an EXPR_LIST if multiple addresses exist. */
165 /* The alignment (in bits) of the slot. */
167 /* The size, in units, of the slot. */
169 /* The type of the object in the slot, or zero if it doesn't correspond
170 to a type. We use this to determine whether a slot can be reused.
171 It can be reused if objects of the type of the new slot will always
172 conflict with objects of the type of the old slot. */
174 /* Nonzero if this temporary is currently in use. */
176 /* Nonzero if this temporary has its address taken. */
178 /* Nesting level at which this slot is being used. */
180 /* Nonzero if this should survive a call to free_temp_slots. */
182 /* The offset of the slot from the frame_pointer, including extra space
183 for alignment. This info is for combine_temp_slots. */
184 HOST_WIDE_INT base_offset;
185 /* The size of the slot, including extra space for alignment. This
186 info is for combine_temp_slots. */
187 HOST_WIDE_INT full_size;
190 /* Forward declarations. */
192 static struct temp_slot *find_temp_slot_from_address (rtx);
193 static void pad_to_arg_alignment (struct args_size *, int, struct args_size *);
194 static void pad_below (struct args_size *, enum machine_mode, tree);
195 static void reorder_blocks_1 (rtx, tree, VEC(tree,heap) **);
196 static int all_blocks (tree, tree *);
197 static tree *get_block_vector (tree, int *);
198 extern tree debug_find_var_in_block_tree (tree, tree);
199 /* We always define `record_insns' even if it's not used so that we
200 can always export `prologue_epilogue_contains'. */
201 static void record_insns (rtx, VEC(int,heap) **) ATTRIBUTE_UNUSED;
202 static int contains (const_rtx, VEC(int,heap) **);
204 static void emit_return_into_block (basic_block);
206 static void prepare_function_start (void);
207 static void do_clobber_return_reg (rtx, void *);
208 static void do_use_return_reg (rtx, void *);
209 static void set_insn_locators (rtx, int) ATTRIBUTE_UNUSED;
211 /* Stack of nested functions. */
212 /* Keep track of the cfun stack. */
214 typedef struct function *function_p;
216 DEF_VEC_P(function_p);
217 DEF_VEC_ALLOC_P(function_p,heap);
218 static VEC(function_p,heap) *function_context_stack;
220 /* Save the current context for compilation of a nested function.
221 This is called from language-specific code. */
224 push_function_context (void)
227 allocate_struct_function (NULL, false);
229 VEC_safe_push (function_p, heap, function_context_stack, cfun);
233 /* Restore the last saved context, at the end of a nested function.
234 This function is called from language-specific code. */
237 pop_function_context (void)
239 struct function *p = VEC_pop (function_p, function_context_stack);
241 current_function_decl = p->decl;
243 /* Reset variables that have known state during rtx generation. */
244 virtuals_instantiated = 0;
245 generating_concat_p = 1;
248 /* Clear out all parts of the state in F that can safely be discarded
249 after the function has been parsed, but not compiled, to let
250 garbage collection reclaim the memory. */
253 free_after_parsing (struct function *f)
258 /* Clear out all parts of the state in F that can safely be discarded
259 after the function has been compiled, to let garbage collection
260 reclaim the memory. */
263 free_after_compilation (struct function *f)
265 VEC_free (int, heap, prologue);
266 VEC_free (int, heap, epilogue);
267 VEC_free (int, heap, sibcall_epilogue);
268 if (crtl->emit.regno_pointer_align)
269 free (crtl->emit.regno_pointer_align);
271 memset (crtl, 0, sizeof (struct rtl_data));
276 regno_reg_rtx = NULL;
277 insn_locators_free ();
280 /* Return size needed for stack frame based on slots so far allocated.
281 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
282 the caller may have to do that. */
285 get_frame_size (void)
287 if (FRAME_GROWS_DOWNWARD)
288 return -frame_offset;
293 /* Issue an error message and return TRUE if frame OFFSET overflows in
294 the signed target pointer arithmetics for function FUNC. Otherwise
298 frame_offset_overflow (HOST_WIDE_INT offset, tree func)
300 unsigned HOST_WIDE_INT size = FRAME_GROWS_DOWNWARD ? -offset : offset;
302 if (size > ((unsigned HOST_WIDE_INT) 1 << (GET_MODE_BITSIZE (Pmode) - 1))
303 /* Leave room for the fixed part of the frame. */
304 - 64 * UNITS_PER_WORD)
306 error ("%Jtotal size of local objects too large", func);
313 /* Return stack slot alignment in bits for TYPE and MODE. */
316 get_stack_local_alignment (tree type, enum machine_mode mode)
318 unsigned int alignment;
321 alignment = BIGGEST_ALIGNMENT;
323 alignment = GET_MODE_ALIGNMENT (mode);
325 /* Allow the frond-end to (possibly) increase the alignment of this
328 type = lang_hooks.types.type_for_mode (mode, 0);
330 return STACK_SLOT_ALIGNMENT (type, mode, alignment);
333 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
334 with machine mode MODE.
336 ALIGN controls the amount of alignment for the address of the slot:
337 0 means according to MODE,
338 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
339 -2 means use BITS_PER_UNIT,
340 positive specifies alignment boundary in bits.
342 If REDUCE_ALIGNMENT_OK is true, it is OK to reduce alignment.
344 We do not round to stack_boundary here. */
347 assign_stack_local_1 (enum machine_mode mode, HOST_WIDE_INT size,
349 bool reduce_alignment_ok ATTRIBUTE_UNUSED)
352 int bigend_correction = 0;
353 unsigned int alignment, alignment_in_bits;
354 int frame_off, frame_alignment, frame_phase;
358 alignment = get_stack_local_alignment (NULL, mode);
359 alignment /= BITS_PER_UNIT;
361 else if (align == -1)
363 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
364 size = CEIL_ROUND (size, alignment);
366 else if (align == -2)
367 alignment = 1; /* BITS_PER_UNIT / BITS_PER_UNIT */
369 alignment = align / BITS_PER_UNIT;
371 alignment_in_bits = alignment * BITS_PER_UNIT;
373 if (FRAME_GROWS_DOWNWARD)
374 frame_offset -= size;
376 /* Ignore alignment if it exceeds MAX_SUPPORTED_STACK_ALIGNMENT. */
377 if (alignment_in_bits > MAX_SUPPORTED_STACK_ALIGNMENT)
379 alignment_in_bits = MAX_SUPPORTED_STACK_ALIGNMENT;
380 alignment = alignment_in_bits / BITS_PER_UNIT;
383 if (SUPPORTS_STACK_ALIGNMENT)
385 if (crtl->stack_alignment_estimated < alignment_in_bits)
387 if (!crtl->stack_realign_processed)
388 crtl->stack_alignment_estimated = alignment_in_bits;
391 /* If stack is realigned and stack alignment value
392 hasn't been finalized, it is OK not to increase
393 stack_alignment_estimated. The bigger alignment
394 requirement is recorded in stack_alignment_needed
396 gcc_assert (!crtl->stack_realign_finalized);
397 if (!crtl->stack_realign_needed)
399 /* It is OK to reduce the alignment as long as the
400 requested size is 0 or the estimated stack
401 alignment >= mode alignment. */
402 gcc_assert (reduce_alignment_ok
404 || (crtl->stack_alignment_estimated
405 >= GET_MODE_ALIGNMENT (mode)));
406 alignment_in_bits = crtl->stack_alignment_estimated;
407 alignment = alignment_in_bits / BITS_PER_UNIT;
413 if (crtl->stack_alignment_needed < alignment_in_bits)
414 crtl->stack_alignment_needed = alignment_in_bits;
415 if (crtl->max_used_stack_slot_alignment < crtl->stack_alignment_needed)
416 crtl->max_used_stack_slot_alignment = crtl->stack_alignment_needed;
418 /* Calculate how many bytes the start of local variables is off from
420 frame_alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
421 frame_off = STARTING_FRAME_OFFSET % frame_alignment;
422 frame_phase = frame_off ? frame_alignment - frame_off : 0;
424 /* Round the frame offset to the specified alignment. The default is
425 to always honor requests to align the stack but a port may choose to
426 do its own stack alignment by defining STACK_ALIGNMENT_NEEDED. */
427 if (STACK_ALIGNMENT_NEEDED
431 /* We must be careful here, since FRAME_OFFSET might be negative and
432 division with a negative dividend isn't as well defined as we might
433 like. So we instead assume that ALIGNMENT is a power of two and
434 use logical operations which are unambiguous. */
435 if (FRAME_GROWS_DOWNWARD)
437 = (FLOOR_ROUND (frame_offset - frame_phase,
438 (unsigned HOST_WIDE_INT) alignment)
442 = (CEIL_ROUND (frame_offset - frame_phase,
443 (unsigned HOST_WIDE_INT) alignment)
447 /* On a big-endian machine, if we are allocating more space than we will use,
448 use the least significant bytes of those that are allocated. */
449 if (BYTES_BIG_ENDIAN && mode != BLKmode && GET_MODE_SIZE (mode) < size)
450 bigend_correction = size - GET_MODE_SIZE (mode);
452 /* If we have already instantiated virtual registers, return the actual
453 address relative to the frame pointer. */
454 if (virtuals_instantiated)
455 addr = plus_constant (frame_pointer_rtx,
457 (frame_offset + bigend_correction
458 + STARTING_FRAME_OFFSET, Pmode));
460 addr = plus_constant (virtual_stack_vars_rtx,
462 (frame_offset + bigend_correction,
465 if (!FRAME_GROWS_DOWNWARD)
466 frame_offset += size;
468 x = gen_rtx_MEM (mode, addr);
469 set_mem_align (x, alignment_in_bits);
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 /* Wrap up assign_stack_local_1 with last parameter as false. */
484 assign_stack_local (enum machine_mode mode, HOST_WIDE_INT size, int align)
486 return assign_stack_local_1 (mode, size, align, false);
489 /* Removes temporary slot TEMP from LIST. */
492 cut_slot_from_list (struct temp_slot *temp, struct temp_slot **list)
495 temp->next->prev = temp->prev;
497 temp->prev->next = temp->next;
501 temp->prev = temp->next = NULL;
504 /* Inserts temporary slot TEMP to LIST. */
507 insert_slot_to_list (struct temp_slot *temp, struct temp_slot **list)
511 (*list)->prev = temp;
516 /* Returns the list of used temp slots at LEVEL. */
518 static struct temp_slot **
519 temp_slots_at_level (int level)
521 if (level >= (int) VEC_length (temp_slot_p, used_temp_slots))
522 VEC_safe_grow_cleared (temp_slot_p, gc, used_temp_slots, level + 1);
524 return &(VEC_address (temp_slot_p, used_temp_slots)[level]);
527 /* Returns the maximal temporary slot level. */
530 max_slot_level (void)
532 if (!used_temp_slots)
535 return VEC_length (temp_slot_p, used_temp_slots) - 1;
538 /* Moves temporary slot TEMP to LEVEL. */
541 move_slot_to_level (struct temp_slot *temp, int level)
543 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
544 insert_slot_to_list (temp, temp_slots_at_level (level));
548 /* Make temporary slot TEMP available. */
551 make_slot_available (struct temp_slot *temp)
553 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
554 insert_slot_to_list (temp, &avail_temp_slots);
559 /* Allocate a temporary stack slot and record it for possible later
562 MODE is the machine mode to be given to the returned rtx.
564 SIZE is the size in units of the space required. We do no rounding here
565 since assign_stack_local will do any required rounding.
567 KEEP is 1 if this slot is to be retained after a call to
568 free_temp_slots. Automatic variables for a block are allocated
569 with this flag. KEEP values of 2 or 3 were needed respectively
570 for variables whose lifetime is controlled by CLEANUP_POINT_EXPRs
571 or for SAVE_EXPRs, but they are now unused.
573 TYPE is the type that will be used for the stack slot. */
576 assign_stack_temp_for_type (enum machine_mode mode, HOST_WIDE_INT size,
580 struct temp_slot *p, *best_p = 0, *selected = NULL, **pp;
583 /* If SIZE is -1 it means that somebody tried to allocate a temporary
584 of a variable size. */
585 gcc_assert (size != -1);
587 /* These are now unused. */
588 gcc_assert (keep <= 1);
590 align = get_stack_local_alignment (type, mode);
592 /* Try to find an available, already-allocated temporary of the proper
593 mode which meets the size and alignment requirements. Choose the
594 smallest one with the closest alignment.
596 If assign_stack_temp is called outside of the tree->rtl expansion,
597 we cannot reuse the stack slots (that may still refer to
598 VIRTUAL_STACK_VARS_REGNUM). */
599 if (!virtuals_instantiated)
601 for (p = avail_temp_slots; p; p = p->next)
603 if (p->align >= align && p->size >= size
604 && GET_MODE (p->slot) == mode
605 && objects_must_conflict_p (p->type, type)
606 && (best_p == 0 || best_p->size > p->size
607 || (best_p->size == p->size && best_p->align > p->align)))
609 if (p->align == align && p->size == size)
612 cut_slot_from_list (selected, &avail_temp_slots);
621 /* Make our best, if any, the one to use. */
625 cut_slot_from_list (selected, &avail_temp_slots);
627 /* If there are enough aligned bytes left over, make them into a new
628 temp_slot so that the extra bytes don't get wasted. Do this only
629 for BLKmode slots, so that we can be sure of the alignment. */
630 if (GET_MODE (best_p->slot) == BLKmode)
632 int alignment = best_p->align / BITS_PER_UNIT;
633 HOST_WIDE_INT rounded_size = CEIL_ROUND (size, alignment);
635 if (best_p->size - rounded_size >= alignment)
637 p = GGC_NEW (struct temp_slot);
638 p->in_use = p->addr_taken = 0;
639 p->size = best_p->size - rounded_size;
640 p->base_offset = best_p->base_offset + rounded_size;
641 p->full_size = best_p->full_size - rounded_size;
642 p->slot = adjust_address_nv (best_p->slot, BLKmode, rounded_size);
643 p->align = best_p->align;
645 p->type = best_p->type;
646 insert_slot_to_list (p, &avail_temp_slots);
648 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, p->slot,
651 best_p->size = rounded_size;
652 best_p->full_size = rounded_size;
657 /* If we still didn't find one, make a new temporary. */
660 HOST_WIDE_INT frame_offset_old = frame_offset;
662 p = GGC_NEW (struct temp_slot);
664 /* We are passing an explicit alignment request to assign_stack_local.
665 One side effect of that is assign_stack_local will not round SIZE
666 to ensure the frame offset remains suitably aligned.
668 So for requests which depended on the rounding of SIZE, we go ahead
669 and round it now. We also make sure ALIGNMENT is at least
670 BIGGEST_ALIGNMENT. */
671 gcc_assert (mode != BLKmode || align == BIGGEST_ALIGNMENT);
672 p->slot = assign_stack_local (mode,
674 ? CEIL_ROUND (size, (int) align / BITS_PER_UNIT)
680 /* The following slot size computation is necessary because we don't
681 know the actual size of the temporary slot until assign_stack_local
682 has performed all the frame alignment and size rounding for the
683 requested temporary. Note that extra space added for alignment
684 can be either above or below this stack slot depending on which
685 way the frame grows. We include the extra space if and only if it
686 is above this slot. */
687 if (FRAME_GROWS_DOWNWARD)
688 p->size = frame_offset_old - frame_offset;
692 /* Now define the fields used by combine_temp_slots. */
693 if (FRAME_GROWS_DOWNWARD)
695 p->base_offset = frame_offset;
696 p->full_size = frame_offset_old - frame_offset;
700 p->base_offset = frame_offset_old;
701 p->full_size = frame_offset - frame_offset_old;
712 p->level = temp_slot_level;
715 pp = temp_slots_at_level (p->level);
716 insert_slot_to_list (p, pp);
718 /* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
719 slot = gen_rtx_MEM (mode, XEXP (p->slot, 0));
720 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, slot, stack_slot_list);
722 /* If we know the alias set for the memory that will be used, use
723 it. If there's no TYPE, then we don't know anything about the
724 alias set for the memory. */
725 set_mem_alias_set (slot, type ? get_alias_set (type) : 0);
726 set_mem_align (slot, align);
728 /* If a type is specified, set the relevant flags. */
731 MEM_VOLATILE_P (slot) = TYPE_VOLATILE (type);
732 MEM_SET_IN_STRUCT_P (slot, (AGGREGATE_TYPE_P (type)
733 || TREE_CODE (type) == COMPLEX_TYPE));
735 MEM_NOTRAP_P (slot) = 1;
740 /* Allocate a temporary stack slot and record it for possible later
741 reuse. First three arguments are same as in preceding function. */
744 assign_stack_temp (enum machine_mode mode, HOST_WIDE_INT size, int keep)
746 return assign_stack_temp_for_type (mode, size, keep, NULL_TREE);
749 /* Assign a temporary.
750 If TYPE_OR_DECL is a decl, then we are doing it on behalf of the decl
751 and so that should be used in error messages. In either case, we
752 allocate of the given type.
753 KEEP is as for assign_stack_temp.
754 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
755 it is 0 if a register is OK.
756 DONT_PROMOTE is 1 if we should not promote values in register
760 assign_temp (tree type_or_decl, int keep, int memory_required,
761 int dont_promote ATTRIBUTE_UNUSED)
764 enum machine_mode mode;
769 if (DECL_P (type_or_decl))
770 decl = type_or_decl, type = TREE_TYPE (decl);
772 decl = NULL, type = type_or_decl;
774 mode = TYPE_MODE (type);
776 unsignedp = TYPE_UNSIGNED (type);
779 if (mode == BLKmode || memory_required)
781 HOST_WIDE_INT size = int_size_in_bytes (type);
784 /* Zero sized arrays are GNU C extension. Set size to 1 to avoid
785 problems with allocating the stack space. */
789 /* Unfortunately, we don't yet know how to allocate variable-sized
790 temporaries. However, sometimes we can find a fixed upper limit on
791 the size, so try that instead. */
793 size = max_int_size_in_bytes (type);
795 /* The size of the temporary may be too large to fit into an integer. */
796 /* ??? Not sure this should happen except for user silliness, so limit
797 this to things that aren't compiler-generated temporaries. The
798 rest of the time we'll die in assign_stack_temp_for_type. */
799 if (decl && size == -1
800 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST)
802 error ("size of variable %q+D is too large", decl);
806 tmp = assign_stack_temp_for_type (mode, size, keep, type);
812 mode = promote_mode (type, mode, &unsignedp, 0);
815 return gen_reg_rtx (mode);
818 /* Combine temporary stack slots which are adjacent on the stack.
820 This allows for better use of already allocated stack space. This is only
821 done for BLKmode slots because we can be sure that we won't have alignment
822 problems in this case. */
825 combine_temp_slots (void)
827 struct temp_slot *p, *q, *next, *next_q;
830 /* We can't combine slots, because the information about which slot
831 is in which alias set will be lost. */
832 if (flag_strict_aliasing)
835 /* If there are a lot of temp slots, don't do anything unless
836 high levels of optimization. */
837 if (! flag_expensive_optimizations)
838 for (p = avail_temp_slots, num_slots = 0; p; p = p->next, num_slots++)
839 if (num_slots > 100 || (num_slots > 10 && optimize == 0))
842 for (p = avail_temp_slots; p; p = next)
848 if (GET_MODE (p->slot) != BLKmode)
851 for (q = p->next; q; q = next_q)
857 if (GET_MODE (q->slot) != BLKmode)
860 if (p->base_offset + p->full_size == q->base_offset)
862 /* Q comes after P; combine Q into P. */
864 p->full_size += q->full_size;
867 else if (q->base_offset + q->full_size == p->base_offset)
869 /* P comes after Q; combine P into Q. */
871 q->full_size += p->full_size;
876 cut_slot_from_list (q, &avail_temp_slots);
879 /* Either delete P or advance past it. */
881 cut_slot_from_list (p, &avail_temp_slots);
885 /* Find the temp slot corresponding to the object at address X. */
887 static struct temp_slot *
888 find_temp_slot_from_address (rtx x)
894 for (i = max_slot_level (); i >= 0; i--)
895 for (p = *temp_slots_at_level (i); p; p = p->next)
897 if (XEXP (p->slot, 0) == x
899 || (GET_CODE (x) == PLUS
900 && XEXP (x, 0) == virtual_stack_vars_rtx
901 && GET_CODE (XEXP (x, 1)) == CONST_INT
902 && INTVAL (XEXP (x, 1)) >= p->base_offset
903 && INTVAL (XEXP (x, 1)) < p->base_offset + p->full_size))
906 else if (p->address != 0 && GET_CODE (p->address) == EXPR_LIST)
907 for (next = p->address; next; next = XEXP (next, 1))
908 if (XEXP (next, 0) == x)
912 /* If we have a sum involving a register, see if it points to a temp
914 if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 0))
915 && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
917 else if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 1))
918 && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
924 /* Indicate that NEW_RTX is an alternate way of referring to the temp
925 slot that previously was known by OLD_RTX. */
928 update_temp_slot_address (rtx old_rtx, rtx new_rtx)
932 if (rtx_equal_p (old_rtx, new_rtx))
935 p = find_temp_slot_from_address (old_rtx);
937 /* If we didn't find one, see if both OLD_RTX is a PLUS. If so, and
938 NEW_RTX is a register, see if one operand of the PLUS is a
939 temporary location. If so, NEW_RTX points into it. Otherwise,
940 if both OLD_RTX and NEW_RTX are a PLUS and if there is a register
941 in common between them. If so, try a recursive call on those
945 if (GET_CODE (old_rtx) != PLUS)
950 update_temp_slot_address (XEXP (old_rtx, 0), new_rtx);
951 update_temp_slot_address (XEXP (old_rtx, 1), new_rtx);
954 else if (GET_CODE (new_rtx) != PLUS)
957 if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 0)))
958 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 1));
959 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 0)))
960 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 1));
961 else if (rtx_equal_p (XEXP (old_rtx, 0), XEXP (new_rtx, 1)))
962 update_temp_slot_address (XEXP (old_rtx, 1), XEXP (new_rtx, 0));
963 else if (rtx_equal_p (XEXP (old_rtx, 1), XEXP (new_rtx, 1)))
964 update_temp_slot_address (XEXP (old_rtx, 0), XEXP (new_rtx, 0));
969 /* Otherwise add an alias for the temp's address. */
970 else if (p->address == 0)
971 p->address = new_rtx;
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_rtx, 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 `crtl->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 ? (crtl->outgoing_args_size \
1185 + (OUTGOING_REG_PARM_STACK_SPACE ((!(FNDECL) ? NULL_TREE : TREE_TYPE (FNDECL))) ? 0 \
1186 : REG_PARM_STACK_SPACE (FNDECL))) \
1187 : 0) + (STACK_POINTER_OFFSET))
1189 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1190 ((ACCUMULATE_OUTGOING_ARGS ? crtl->outgoing_args_size : 0) \
1191 + (STACK_POINTER_OFFSET))
1196 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
1197 is a virtual register, return the equivalent hard register and set the
1198 offset indirectly through the pointer. Otherwise, return 0. */
1201 instantiate_new_reg (rtx x, HOST_WIDE_INT *poffset)
1204 HOST_WIDE_INT offset;
1206 if (x == virtual_incoming_args_rtx)
1208 if (stack_realign_drap)
1210 /* Replace virtual_incoming_args_rtx with internal arg
1211 pointer if DRAP is used to realign stack. */
1212 new_rtx = crtl->args.internal_arg_pointer;
1216 new_rtx = arg_pointer_rtx, offset = in_arg_offset;
1218 else if (x == virtual_stack_vars_rtx)
1219 new_rtx = frame_pointer_rtx, offset = var_offset;
1220 else if (x == virtual_stack_dynamic_rtx)
1221 new_rtx = stack_pointer_rtx, offset = dynamic_offset;
1222 else if (x == virtual_outgoing_args_rtx)
1223 new_rtx = stack_pointer_rtx, offset = out_arg_offset;
1224 else if (x == virtual_cfa_rtx)
1226 #ifdef FRAME_POINTER_CFA_OFFSET
1227 new_rtx = frame_pointer_rtx;
1229 new_rtx = arg_pointer_rtx;
1231 offset = cfa_offset;
1240 /* A subroutine of instantiate_virtual_regs, called via for_each_rtx.
1241 Instantiate any virtual registers present inside of *LOC. The expression
1242 is simplified, as much as possible, but is not to be considered "valid"
1243 in any sense implied by the target. If any change is made, set CHANGED
1247 instantiate_virtual_regs_in_rtx (rtx *loc, void *data)
1249 HOST_WIDE_INT offset;
1250 bool *changed = (bool *) data;
1257 switch (GET_CODE (x))
1260 new_rtx = instantiate_new_reg (x, &offset);
1263 *loc = plus_constant (new_rtx, offset);
1270 new_rtx = instantiate_new_reg (XEXP (x, 0), &offset);
1273 new_rtx = plus_constant (new_rtx, offset);
1274 *loc = simplify_gen_binary (PLUS, GET_MODE (x), new_rtx, XEXP (x, 1));
1280 /* FIXME -- from old code */
1281 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
1282 we can commute the PLUS and SUBREG because pointers into the
1283 frame are well-behaved. */
1293 /* A subroutine of instantiate_virtual_regs_in_insn. Return true if X
1294 matches the predicate for insn CODE operand OPERAND. */
1297 safe_insn_predicate (int code, int operand, rtx x)
1299 const struct insn_operand_data *op_data;
1304 op_data = &insn_data[code].operand[operand];
1305 if (op_data->predicate == NULL)
1308 return op_data->predicate (x, op_data->mode);
1311 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1312 registers present inside of insn. The result will be a valid insn. */
1315 instantiate_virtual_regs_in_insn (rtx insn)
1317 HOST_WIDE_INT offset;
1319 bool any_change = false;
1320 rtx set, new_rtx, x, seq;
1322 /* There are some special cases to be handled first. */
1323 set = single_set (insn);
1326 /* We're allowed to assign to a virtual register. This is interpreted
1327 to mean that the underlying register gets assigned the inverse
1328 transformation. This is used, for example, in the handling of
1330 new_rtx = instantiate_new_reg (SET_DEST (set), &offset);
1335 for_each_rtx (&SET_SRC (set), instantiate_virtual_regs_in_rtx, NULL);
1336 x = simplify_gen_binary (PLUS, GET_MODE (new_rtx), SET_SRC (set),
1338 x = force_operand (x, new_rtx);
1340 emit_move_insn (new_rtx, x);
1345 emit_insn_before (seq, insn);
1350 /* Handle a straight copy from a virtual register by generating a
1351 new add insn. The difference between this and falling through
1352 to the generic case is avoiding a new pseudo and eliminating a
1353 move insn in the initial rtl stream. */
1354 new_rtx = instantiate_new_reg (SET_SRC (set), &offset);
1355 if (new_rtx && offset != 0
1356 && REG_P (SET_DEST (set))
1357 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1361 x = expand_simple_binop (GET_MODE (SET_DEST (set)), PLUS,
1362 new_rtx, GEN_INT (offset), SET_DEST (set),
1363 1, OPTAB_LIB_WIDEN);
1364 if (x != SET_DEST (set))
1365 emit_move_insn (SET_DEST (set), x);
1370 emit_insn_before (seq, insn);
1375 extract_insn (insn);
1376 insn_code = INSN_CODE (insn);
1378 /* Handle a plus involving a virtual register by determining if the
1379 operands remain valid if they're modified in place. */
1380 if (GET_CODE (SET_SRC (set)) == PLUS
1381 && recog_data.n_operands >= 3
1382 && recog_data.operand_loc[1] == &XEXP (SET_SRC (set), 0)
1383 && recog_data.operand_loc[2] == &XEXP (SET_SRC (set), 1)
1384 && GET_CODE (recog_data.operand[2]) == CONST_INT
1385 && (new_rtx = instantiate_new_reg (recog_data.operand[1], &offset)))
1387 offset += INTVAL (recog_data.operand[2]);
1389 /* If the sum is zero, then replace with a plain move. */
1391 && REG_P (SET_DEST (set))
1392 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1395 emit_move_insn (SET_DEST (set), new_rtx);
1399 emit_insn_before (seq, insn);
1404 x = gen_int_mode (offset, recog_data.operand_mode[2]);
1406 /* Using validate_change and apply_change_group here leaves
1407 recog_data in an invalid state. Since we know exactly what
1408 we want to check, do those two by hand. */
1409 if (safe_insn_predicate (insn_code, 1, new_rtx)
1410 && safe_insn_predicate (insn_code, 2, x))
1412 *recog_data.operand_loc[1] = recog_data.operand[1] = new_rtx;
1413 *recog_data.operand_loc[2] = recog_data.operand[2] = x;
1416 /* Fall through into the regular operand fixup loop in
1417 order to take care of operands other than 1 and 2. */
1423 extract_insn (insn);
1424 insn_code = INSN_CODE (insn);
1427 /* In the general case, we expect virtual registers to appear only in
1428 operands, and then only as either bare registers or inside memories. */
1429 for (i = 0; i < recog_data.n_operands; ++i)
1431 x = recog_data.operand[i];
1432 switch (GET_CODE (x))
1436 rtx addr = XEXP (x, 0);
1437 bool changed = false;
1439 for_each_rtx (&addr, instantiate_virtual_regs_in_rtx, &changed);
1444 x = replace_equiv_address (x, addr);
1445 /* It may happen that the address with the virtual reg
1446 was valid (e.g. based on the virtual stack reg, which might
1447 be acceptable to the predicates with all offsets), whereas
1448 the address now isn't anymore, for instance when the address
1449 is still offsetted, but the base reg isn't virtual-stack-reg
1450 anymore. Below we would do a force_reg on the whole operand,
1451 but this insn might actually only accept memory. Hence,
1452 before doing that last resort, try to reload the address into
1453 a register, so this operand stays a MEM. */
1454 if (!safe_insn_predicate (insn_code, i, x))
1456 addr = force_reg (GET_MODE (addr), addr);
1457 x = replace_equiv_address (x, addr);
1462 emit_insn_before (seq, insn);
1467 new_rtx = instantiate_new_reg (x, &offset);
1468 if (new_rtx == NULL)
1476 /* Careful, special mode predicates may have stuff in
1477 insn_data[insn_code].operand[i].mode that isn't useful
1478 to us for computing a new value. */
1479 /* ??? Recognize address_operand and/or "p" constraints
1480 to see if (plus new offset) is a valid before we put
1481 this through expand_simple_binop. */
1482 x = expand_simple_binop (GET_MODE (x), PLUS, new_rtx,
1483 GEN_INT (offset), NULL_RTX,
1484 1, OPTAB_LIB_WIDEN);
1487 emit_insn_before (seq, insn);
1492 new_rtx = instantiate_new_reg (SUBREG_REG (x), &offset);
1493 if (new_rtx == NULL)
1498 new_rtx = expand_simple_binop (GET_MODE (new_rtx), PLUS, new_rtx,
1499 GEN_INT (offset), NULL_RTX,
1500 1, OPTAB_LIB_WIDEN);
1503 emit_insn_before (seq, insn);
1505 x = simplify_gen_subreg (recog_data.operand_mode[i], new_rtx,
1506 GET_MODE (new_rtx), SUBREG_BYTE (x));
1514 /* At this point, X contains the new value for the operand.
1515 Validate the new value vs the insn predicate. Note that
1516 asm insns will have insn_code -1 here. */
1517 if (!safe_insn_predicate (insn_code, i, x))
1520 x = force_reg (insn_data[insn_code].operand[i].mode, x);
1524 emit_insn_before (seq, insn);
1527 *recog_data.operand_loc[i] = recog_data.operand[i] = x;
1533 /* Propagate operand changes into the duplicates. */
1534 for (i = 0; i < recog_data.n_dups; ++i)
1535 *recog_data.dup_loc[i]
1536 = copy_rtx (recog_data.operand[(unsigned)recog_data.dup_num[i]]);
1538 /* Force re-recognition of the instruction for validation. */
1539 INSN_CODE (insn) = -1;
1542 if (asm_noperands (PATTERN (insn)) >= 0)
1544 if (!check_asm_operands (PATTERN (insn)))
1546 error_for_asm (insn, "impossible constraint in %<asm%>");
1552 if (recog_memoized (insn) < 0)
1553 fatal_insn_not_found (insn);
1557 /* Subroutine of instantiate_decls. Given RTL representing a decl,
1558 do any instantiation required. */
1561 instantiate_decl_rtl (rtx x)
1568 /* If this is a CONCAT, recurse for the pieces. */
1569 if (GET_CODE (x) == CONCAT)
1571 instantiate_decl_rtl (XEXP (x, 0));
1572 instantiate_decl_rtl (XEXP (x, 1));
1576 /* If this is not a MEM, no need to do anything. Similarly if the
1577 address is a constant or a register that is not a virtual register. */
1582 if (CONSTANT_P (addr)
1584 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
1585 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
1588 for_each_rtx (&XEXP (x, 0), instantiate_virtual_regs_in_rtx, NULL);
1591 /* Helper for instantiate_decls called via walk_tree: Process all decls
1592 in the given DECL_VALUE_EXPR. */
1595 instantiate_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1601 if (DECL_P (t) && DECL_RTL_SET_P (t))
1602 instantiate_decl_rtl (DECL_RTL (t));
1607 /* Subroutine of instantiate_decls: Process all decls in the given
1608 BLOCK node and all its subblocks. */
1611 instantiate_decls_1 (tree let)
1615 for (t = BLOCK_VARS (let); t; t = TREE_CHAIN (t))
1617 if (DECL_RTL_SET_P (t))
1618 instantiate_decl_rtl (DECL_RTL (t));
1619 if (TREE_CODE (t) == VAR_DECL && DECL_HAS_VALUE_EXPR_P (t))
1621 tree v = DECL_VALUE_EXPR (t);
1622 walk_tree (&v, instantiate_expr, NULL, NULL);
1626 /* Process all subblocks. */
1627 for (t = BLOCK_SUBBLOCKS (let); t; t = BLOCK_CHAIN (t))
1628 instantiate_decls_1 (t);
1631 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1632 all virtual registers in their DECL_RTL's. */
1635 instantiate_decls (tree fndecl)
1639 /* Process all parameters of the function. */
1640 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = TREE_CHAIN (decl))
1642 instantiate_decl_rtl (DECL_RTL (decl));
1643 instantiate_decl_rtl (DECL_INCOMING_RTL (decl));
1644 if (DECL_HAS_VALUE_EXPR_P (decl))
1646 tree v = DECL_VALUE_EXPR (decl);
1647 walk_tree (&v, instantiate_expr, NULL, NULL);
1651 /* Now process all variables defined in the function or its subblocks. */
1652 instantiate_decls_1 (DECL_INITIAL (fndecl));
1654 t = cfun->local_decls;
1655 cfun->local_decls = NULL_TREE;
1658 next = TREE_CHAIN (t);
1659 decl = TREE_VALUE (t);
1660 if (DECL_RTL_SET_P (decl))
1661 instantiate_decl_rtl (DECL_RTL (decl));
1666 /* Pass through the INSNS of function FNDECL and convert virtual register
1667 references to hard register references. */
1670 instantiate_virtual_regs (void)
1674 /* Compute the offsets to use for this function. */
1675 in_arg_offset = FIRST_PARM_OFFSET (current_function_decl);
1676 var_offset = STARTING_FRAME_OFFSET;
1677 dynamic_offset = STACK_DYNAMIC_OFFSET (current_function_decl);
1678 out_arg_offset = STACK_POINTER_OFFSET;
1679 #ifdef FRAME_POINTER_CFA_OFFSET
1680 cfa_offset = FRAME_POINTER_CFA_OFFSET (current_function_decl);
1682 cfa_offset = ARG_POINTER_CFA_OFFSET (current_function_decl);
1685 /* Initialize recognition, indicating that volatile is OK. */
1688 /* Scan through all the insns, instantiating every virtual register still
1690 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
1693 /* These patterns in the instruction stream can never be recognized.
1694 Fortunately, they shouldn't contain virtual registers either. */
1695 if (GET_CODE (PATTERN (insn)) == USE
1696 || GET_CODE (PATTERN (insn)) == CLOBBER
1697 || GET_CODE (PATTERN (insn)) == ADDR_VEC
1698 || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC
1699 || GET_CODE (PATTERN (insn)) == ASM_INPUT)
1702 instantiate_virtual_regs_in_insn (insn);
1704 if (INSN_DELETED_P (insn))
1707 for_each_rtx (®_NOTES (insn), instantiate_virtual_regs_in_rtx, NULL);
1709 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
1710 if (GET_CODE (insn) == CALL_INSN)
1711 for_each_rtx (&CALL_INSN_FUNCTION_USAGE (insn),
1712 instantiate_virtual_regs_in_rtx, NULL);
1715 /* Instantiate the virtual registers in the DECLs for debugging purposes. */
1716 instantiate_decls (current_function_decl);
1718 targetm.instantiate_decls ();
1720 /* Indicate that, from now on, assign_stack_local should use
1721 frame_pointer_rtx. */
1722 virtuals_instantiated = 1;
1726 struct rtl_opt_pass pass_instantiate_virtual_regs =
1732 instantiate_virtual_regs, /* execute */
1735 0, /* static_pass_number */
1737 0, /* properties_required */
1738 0, /* properties_provided */
1739 0, /* properties_destroyed */
1740 0, /* todo_flags_start */
1741 TODO_dump_func /* todo_flags_finish */
1746 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
1747 This means a type for which function calls must pass an address to the
1748 function or get an address back from the function.
1749 EXP may be a type node or an expression (whose type is tested). */
1752 aggregate_value_p (const_tree exp, const_tree fntype)
1754 int i, regno, nregs;
1757 const_tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
1759 /* DECL node associated with FNTYPE when relevant, which we might need to
1760 check for by-invisible-reference returns, typically for CALL_EXPR input
1762 const_tree fndecl = NULL_TREE;
1765 switch (TREE_CODE (fntype))
1768 fndecl = get_callee_fndecl (fntype);
1769 fntype = fndecl ? TREE_TYPE (fndecl) : 0;
1773 fntype = TREE_TYPE (fndecl);
1778 case IDENTIFIER_NODE:
1782 /* We don't expect other rtl types here. */
1786 if (TREE_CODE (type) == VOID_TYPE)
1789 /* If the front end has decided that this needs to be passed by
1790 reference, do so. */
1791 if ((TREE_CODE (exp) == PARM_DECL || TREE_CODE (exp) == RESULT_DECL)
1792 && DECL_BY_REFERENCE (exp))
1795 /* If the EXPression is a CALL_EXPR, honor DECL_BY_REFERENCE set on the
1796 called function RESULT_DECL, meaning the function returns in memory by
1797 invisible reference. This check lets front-ends not set TREE_ADDRESSABLE
1798 on the function type, which used to be the way to request such a return
1799 mechanism but might now be causing troubles at gimplification time if
1800 temporaries with the function type need to be created. */
1801 if (TREE_CODE (exp) == CALL_EXPR && fndecl && DECL_RESULT (fndecl)
1802 && DECL_BY_REFERENCE (DECL_RESULT (fndecl)))
1805 if (targetm.calls.return_in_memory (type, fntype))
1807 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
1808 and thus can't be returned in registers. */
1809 if (TREE_ADDRESSABLE (type))
1811 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
1813 /* Make sure we have suitable call-clobbered regs to return
1814 the value in; if not, we must return it in memory. */
1815 reg = hard_function_value (type, 0, fntype, 0);
1817 /* If we have something other than a REG (e.g. a PARALLEL), then assume
1822 regno = REGNO (reg);
1823 nregs = hard_regno_nregs[regno][TYPE_MODE (type)];
1824 for (i = 0; i < nregs; i++)
1825 if (! call_used_regs[regno + i])
1830 /* Return true if we should assign DECL a pseudo register; false if it
1831 should live on the local stack. */
1834 use_register_for_decl (const_tree decl)
1836 if (!targetm.calls.allocate_stack_slots_for_args())
1839 /* Honor volatile. */
1840 if (TREE_SIDE_EFFECTS (decl))
1843 /* Honor addressability. */
1844 if (TREE_ADDRESSABLE (decl))
1847 /* Only register-like things go in registers. */
1848 if (DECL_MODE (decl) == BLKmode)
1851 /* If -ffloat-store specified, don't put explicit float variables
1853 /* ??? This should be checked after DECL_ARTIFICIAL, but tree-ssa
1854 propagates values across these stores, and it probably shouldn't. */
1855 if (flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)))
1858 /* If we're not interested in tracking debugging information for
1859 this decl, then we can certainly put it in a register. */
1860 if (DECL_IGNORED_P (decl))
1863 return (optimize || DECL_REGISTER (decl));
1866 /* Return true if TYPE should be passed by invisible reference. */
1869 pass_by_reference (CUMULATIVE_ARGS *ca, enum machine_mode mode,
1870 tree type, bool named_arg)
1874 /* If this type contains non-trivial constructors, then it is
1875 forbidden for the middle-end to create any new copies. */
1876 if (TREE_ADDRESSABLE (type))
1879 /* GCC post 3.4 passes *all* variable sized types by reference. */
1880 if (!TYPE_SIZE (type) || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
1884 return targetm.calls.pass_by_reference (ca, mode, type, named_arg);
1887 /* Return true if TYPE, which is passed by reference, should be callee
1888 copied instead of caller copied. */
1891 reference_callee_copied (CUMULATIVE_ARGS *ca, enum machine_mode mode,
1892 tree type, bool named_arg)
1894 if (type && TREE_ADDRESSABLE (type))
1896 return targetm.calls.callee_copies (ca, mode, type, named_arg);
1899 /* Structures to communicate between the subroutines of assign_parms.
1900 The first holds data persistent across all parameters, the second
1901 is cleared out for each parameter. */
1903 struct assign_parm_data_all
1905 CUMULATIVE_ARGS args_so_far;
1906 struct args_size stack_args_size;
1907 tree function_result_decl;
1909 rtx first_conversion_insn;
1910 rtx last_conversion_insn;
1911 HOST_WIDE_INT pretend_args_size;
1912 HOST_WIDE_INT extra_pretend_bytes;
1913 int reg_parm_stack_space;
1916 struct assign_parm_data_one
1922 enum machine_mode nominal_mode;
1923 enum machine_mode passed_mode;
1924 enum machine_mode promoted_mode;
1925 struct locate_and_pad_arg_data locate;
1927 BOOL_BITFIELD named_arg : 1;
1928 BOOL_BITFIELD passed_pointer : 1;
1929 BOOL_BITFIELD on_stack : 1;
1930 BOOL_BITFIELD loaded_in_reg : 1;
1933 /* A subroutine of assign_parms. Initialize ALL. */
1936 assign_parms_initialize_all (struct assign_parm_data_all *all)
1940 memset (all, 0, sizeof (*all));
1942 fntype = TREE_TYPE (current_function_decl);
1944 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
1945 INIT_CUMULATIVE_INCOMING_ARGS (all->args_so_far, fntype, NULL_RTX);
1947 INIT_CUMULATIVE_ARGS (all->args_so_far, fntype, NULL_RTX,
1948 current_function_decl, -1);
1951 #ifdef REG_PARM_STACK_SPACE
1952 all->reg_parm_stack_space = REG_PARM_STACK_SPACE (current_function_decl);
1956 /* If ARGS contains entries with complex types, split the entry into two
1957 entries of the component type. Return a new list of substitutions are
1958 needed, else the old list. */
1961 split_complex_args (tree args)
1965 /* Before allocating memory, check for the common case of no complex. */
1966 for (p = args; p; p = TREE_CHAIN (p))
1968 tree type = TREE_TYPE (p);
1969 if (TREE_CODE (type) == COMPLEX_TYPE
1970 && targetm.calls.split_complex_arg (type))
1976 args = copy_list (args);
1978 for (p = args; p; p = TREE_CHAIN (p))
1980 tree type = TREE_TYPE (p);
1981 if (TREE_CODE (type) == COMPLEX_TYPE
1982 && targetm.calls.split_complex_arg (type))
1985 tree subtype = TREE_TYPE (type);
1986 bool addressable = TREE_ADDRESSABLE (p);
1988 /* Rewrite the PARM_DECL's type with its component. */
1989 TREE_TYPE (p) = subtype;
1990 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
1991 DECL_MODE (p) = VOIDmode;
1992 DECL_SIZE (p) = NULL;
1993 DECL_SIZE_UNIT (p) = NULL;
1994 /* If this arg must go in memory, put it in a pseudo here.
1995 We can't allow it to go in memory as per normal parms,
1996 because the usual place might not have the imag part
1997 adjacent to the real part. */
1998 DECL_ARTIFICIAL (p) = addressable;
1999 DECL_IGNORED_P (p) = addressable;
2000 TREE_ADDRESSABLE (p) = 0;
2003 /* Build a second synthetic decl. */
2004 decl = build_decl (PARM_DECL, NULL_TREE, subtype);
2005 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
2006 DECL_ARTIFICIAL (decl) = addressable;
2007 DECL_IGNORED_P (decl) = addressable;
2008 layout_decl (decl, 0);
2010 /* Splice it in; skip the new decl. */
2011 TREE_CHAIN (decl) = TREE_CHAIN (p);
2012 TREE_CHAIN (p) = decl;
2020 /* A subroutine of assign_parms. Adjust the parameter list to incorporate
2021 the hidden struct return argument, and (abi willing) complex args.
2022 Return the new parameter list. */
2025 assign_parms_augmented_arg_list (struct assign_parm_data_all *all)
2027 tree fndecl = current_function_decl;
2028 tree fntype = TREE_TYPE (fndecl);
2029 tree fnargs = DECL_ARGUMENTS (fndecl);
2031 /* If struct value address is treated as the first argument, make it so. */
2032 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
2033 && ! cfun->returns_pcc_struct
2034 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
2036 tree type = build_pointer_type (TREE_TYPE (fntype));
2039 decl = build_decl (PARM_DECL, NULL_TREE, type);
2040 DECL_ARG_TYPE (decl) = type;
2041 DECL_ARTIFICIAL (decl) = 1;
2042 DECL_IGNORED_P (decl) = 1;
2044 TREE_CHAIN (decl) = fnargs;
2046 all->function_result_decl = decl;
2049 all->orig_fnargs = fnargs;
2051 /* If the target wants to split complex arguments into scalars, do so. */
2052 if (targetm.calls.split_complex_arg)
2053 fnargs = split_complex_args (fnargs);
2058 /* A subroutine of assign_parms. Examine PARM and pull out type and mode
2059 data for the parameter. Incorporate ABI specifics such as pass-by-
2060 reference and type promotion. */
2063 assign_parm_find_data_types (struct assign_parm_data_all *all, tree parm,
2064 struct assign_parm_data_one *data)
2066 tree nominal_type, passed_type;
2067 enum machine_mode nominal_mode, passed_mode, promoted_mode;
2069 memset (data, 0, sizeof (*data));
2071 /* NAMED_ARG is a misnomer. We really mean 'non-variadic'. */
2073 data->named_arg = 1; /* No variadic parms. */
2074 else if (TREE_CHAIN (parm))
2075 data->named_arg = 1; /* Not the last non-variadic parm. */
2076 else if (targetm.calls.strict_argument_naming (&all->args_so_far))
2077 data->named_arg = 1; /* Only variadic ones are unnamed. */
2079 data->named_arg = 0; /* Treat as variadic. */
2081 nominal_type = TREE_TYPE (parm);
2082 passed_type = DECL_ARG_TYPE (parm);
2084 /* Look out for errors propagating this far. Also, if the parameter's
2085 type is void then its value doesn't matter. */
2086 if (TREE_TYPE (parm) == error_mark_node
2087 /* This can happen after weird syntax errors
2088 or if an enum type is defined among the parms. */
2089 || TREE_CODE (parm) != PARM_DECL
2090 || passed_type == NULL
2091 || VOID_TYPE_P (nominal_type))
2093 nominal_type = passed_type = void_type_node;
2094 nominal_mode = passed_mode = promoted_mode = VOIDmode;
2098 /* Find mode of arg as it is passed, and mode of arg as it should be
2099 during execution of this function. */
2100 passed_mode = TYPE_MODE (passed_type);
2101 nominal_mode = TYPE_MODE (nominal_type);
2103 /* If the parm is to be passed as a transparent union, use the type of
2104 the first field for the tests below. We have already verified that
2105 the modes are the same. */
2106 if (TREE_CODE (passed_type) == UNION_TYPE
2107 && TYPE_TRANSPARENT_UNION (passed_type))
2108 passed_type = TREE_TYPE (TYPE_FIELDS (passed_type));
2110 /* See if this arg was passed by invisible reference. */
2111 if (pass_by_reference (&all->args_so_far, passed_mode,
2112 passed_type, data->named_arg))
2114 passed_type = nominal_type = build_pointer_type (passed_type);
2115 data->passed_pointer = true;
2116 passed_mode = nominal_mode = Pmode;
2119 /* Find mode as it is passed by the ABI. */
2120 promoted_mode = passed_mode;
2121 if (targetm.calls.promote_function_args (TREE_TYPE (current_function_decl)))
2123 int unsignedp = TYPE_UNSIGNED (passed_type);
2124 promoted_mode = promote_mode (passed_type, promoted_mode,
2129 data->nominal_type = nominal_type;
2130 data->passed_type = passed_type;
2131 data->nominal_mode = nominal_mode;
2132 data->passed_mode = passed_mode;
2133 data->promoted_mode = promoted_mode;
2136 /* A subroutine of assign_parms. Invoke setup_incoming_varargs. */
2139 assign_parms_setup_varargs (struct assign_parm_data_all *all,
2140 struct assign_parm_data_one *data, bool no_rtl)
2142 int varargs_pretend_bytes = 0;
2144 targetm.calls.setup_incoming_varargs (&all->args_so_far,
2145 data->promoted_mode,
2147 &varargs_pretend_bytes, no_rtl);
2149 /* If the back-end has requested extra stack space, record how much is
2150 needed. Do not change pretend_args_size otherwise since it may be
2151 nonzero from an earlier partial argument. */
2152 if (varargs_pretend_bytes > 0)
2153 all->pretend_args_size = varargs_pretend_bytes;
2156 /* A subroutine of assign_parms. Set DATA->ENTRY_PARM corresponding to
2157 the incoming location of the current parameter. */
2160 assign_parm_find_entry_rtl (struct assign_parm_data_all *all,
2161 struct assign_parm_data_one *data)
2163 HOST_WIDE_INT pretend_bytes = 0;
2167 if (data->promoted_mode == VOIDmode)
2169 data->entry_parm = data->stack_parm = const0_rtx;
2173 #ifdef FUNCTION_INCOMING_ARG
2174 entry_parm = FUNCTION_INCOMING_ARG (all->args_so_far, data->promoted_mode,
2175 data->passed_type, data->named_arg);
2177 entry_parm = FUNCTION_ARG (all->args_so_far, data->promoted_mode,
2178 data->passed_type, data->named_arg);
2181 if (entry_parm == 0)
2182 data->promoted_mode = data->passed_mode;
2184 /* Determine parm's home in the stack, in case it arrives in the stack
2185 or we should pretend it did. Compute the stack position and rtx where
2186 the argument arrives and its size.
2188 There is one complexity here: If this was a parameter that would
2189 have been passed in registers, but wasn't only because it is
2190 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2191 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2192 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of 0
2193 as it was the previous time. */
2194 in_regs = entry_parm != 0;
2195 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2198 if (!in_regs && !data->named_arg)
2200 if (targetm.calls.pretend_outgoing_varargs_named (&all->args_so_far))
2203 #ifdef FUNCTION_INCOMING_ARG
2204 tem = FUNCTION_INCOMING_ARG (all->args_so_far, data->promoted_mode,
2205 data->passed_type, true);
2207 tem = FUNCTION_ARG (all->args_so_far, data->promoted_mode,
2208 data->passed_type, true);
2210 in_regs = tem != NULL;
2214 /* If this parameter was passed both in registers and in the stack, use
2215 the copy on the stack. */
2216 if (targetm.calls.must_pass_in_stack (data->promoted_mode,
2224 partial = targetm.calls.arg_partial_bytes (&all->args_so_far,
2225 data->promoted_mode,
2228 data->partial = partial;
2230 /* The caller might already have allocated stack space for the
2231 register parameters. */
2232 if (partial != 0 && all->reg_parm_stack_space == 0)
2234 /* Part of this argument is passed in registers and part
2235 is passed on the stack. Ask the prologue code to extend
2236 the stack part so that we can recreate the full value.
2238 PRETEND_BYTES is the size of the registers we need to store.
2239 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
2240 stack space that the prologue should allocate.
2242 Internally, gcc assumes that the argument pointer is aligned
2243 to STACK_BOUNDARY bits. This is used both for alignment
2244 optimizations (see init_emit) and to locate arguments that are
2245 aligned to more than PARM_BOUNDARY bits. We must preserve this
2246 invariant by rounding CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to
2247 a stack boundary. */
2249 /* We assume at most one partial arg, and it must be the first
2250 argument on the stack. */
2251 gcc_assert (!all->extra_pretend_bytes && !all->pretend_args_size);
2253 pretend_bytes = partial;
2254 all->pretend_args_size = CEIL_ROUND (pretend_bytes, STACK_BYTES);
2256 /* We want to align relative to the actual stack pointer, so
2257 don't include this in the stack size until later. */
2258 all->extra_pretend_bytes = all->pretend_args_size;
2262 locate_and_pad_parm (data->promoted_mode, data->passed_type, in_regs,
2263 entry_parm ? data->partial : 0, current_function_decl,
2264 &all->stack_args_size, &data->locate);
2266 /* Update parm_stack_boundary if this parameter is passed in the
2268 if (!in_regs && crtl->parm_stack_boundary < data->locate.boundary)
2269 crtl->parm_stack_boundary = data->locate.boundary;
2271 /* Adjust offsets to include the pretend args. */
2272 pretend_bytes = all->extra_pretend_bytes - pretend_bytes;
2273 data->locate.slot_offset.constant += pretend_bytes;
2274 data->locate.offset.constant += pretend_bytes;
2276 data->entry_parm = entry_parm;
2279 /* A subroutine of assign_parms. If there is actually space on the stack
2280 for this parm, count it in stack_args_size and return true. */
2283 assign_parm_is_stack_parm (struct assign_parm_data_all *all,
2284 struct assign_parm_data_one *data)
2286 /* Trivially true if we've no incoming register. */
2287 if (data->entry_parm == NULL)
2289 /* Also true if we're partially in registers and partially not,
2290 since we've arranged to drop the entire argument on the stack. */
2291 else if (data->partial != 0)
2293 /* Also true if the target says that it's passed in both registers
2294 and on the stack. */
2295 else if (GET_CODE (data->entry_parm) == PARALLEL
2296 && XEXP (XVECEXP (data->entry_parm, 0, 0), 0) == NULL_RTX)
2298 /* Also true if the target says that there's stack allocated for
2299 all register parameters. */
2300 else if (all->reg_parm_stack_space > 0)
2302 /* Otherwise, no, this parameter has no ABI defined stack slot. */
2306 all->stack_args_size.constant += data->locate.size.constant;
2307 if (data->locate.size.var)
2308 ADD_PARM_SIZE (all->stack_args_size, data->locate.size.var);
2313 /* A subroutine of assign_parms. Given that this parameter is allocated
2314 stack space by the ABI, find it. */
2317 assign_parm_find_stack_rtl (tree parm, struct assign_parm_data_one *data)
2319 rtx offset_rtx, stack_parm;
2320 unsigned int align, boundary;
2322 /* If we're passing this arg using a reg, make its stack home the
2323 aligned stack slot. */
2324 if (data->entry_parm)
2325 offset_rtx = ARGS_SIZE_RTX (data->locate.slot_offset);
2327 offset_rtx = ARGS_SIZE_RTX (data->locate.offset);
2329 stack_parm = crtl->args.internal_arg_pointer;
2330 if (offset_rtx != const0_rtx)
2331 stack_parm = gen_rtx_PLUS (Pmode, stack_parm, offset_rtx);
2332 stack_parm = gen_rtx_MEM (data->promoted_mode, stack_parm);
2334 set_mem_attributes (stack_parm, parm, 1);
2335 /* set_mem_attributes could set MEM_SIZE to the passed mode's size,
2336 while promoted mode's size is needed. */
2337 if (data->promoted_mode != BLKmode
2338 && data->promoted_mode != DECL_MODE (parm))
2340 set_mem_size (stack_parm, GEN_INT (GET_MODE_SIZE (data->promoted_mode)));
2341 if (MEM_EXPR (stack_parm) && MEM_OFFSET (stack_parm))
2343 int offset = subreg_lowpart_offset (DECL_MODE (parm),
2344 data->promoted_mode);
2346 set_mem_offset (stack_parm,
2347 plus_constant (MEM_OFFSET (stack_parm), -offset));
2351 boundary = data->locate.boundary;
2352 align = BITS_PER_UNIT;
2354 /* If we're padding upward, we know that the alignment of the slot
2355 is FUNCTION_ARG_BOUNDARY. If we're using slot_offset, we're
2356 intentionally forcing upward padding. Otherwise we have to come
2357 up with a guess at the alignment based on OFFSET_RTX. */
2358 if (data->locate.where_pad != downward || data->entry_parm)
2360 else if (GET_CODE (offset_rtx) == CONST_INT)
2362 align = INTVAL (offset_rtx) * BITS_PER_UNIT | boundary;
2363 align = align & -align;
2365 set_mem_align (stack_parm, align);
2367 if (data->entry_parm)
2368 set_reg_attrs_for_parm (data->entry_parm, stack_parm);
2370 data->stack_parm = stack_parm;
2373 /* A subroutine of assign_parms. Adjust DATA->ENTRY_RTL such that it's
2374 always valid and contiguous. */
2377 assign_parm_adjust_entry_rtl (struct assign_parm_data_one *data)
2379 rtx entry_parm = data->entry_parm;
2380 rtx stack_parm = data->stack_parm;
2382 /* If this parm was passed part in regs and part in memory, pretend it
2383 arrived entirely in memory by pushing the register-part onto the stack.
2384 In the special case of a DImode or DFmode that is split, we could put
2385 it together in a pseudoreg directly, but for now that's not worth
2387 if (data->partial != 0)
2389 /* Handle calls that pass values in multiple non-contiguous
2390 locations. The Irix 6 ABI has examples of this. */
2391 if (GET_CODE (entry_parm) == PARALLEL)
2392 emit_group_store (validize_mem (stack_parm), entry_parm,
2394 int_size_in_bytes (data->passed_type));
2397 gcc_assert (data->partial % UNITS_PER_WORD == 0);
2398 move_block_from_reg (REGNO (entry_parm), validize_mem (stack_parm),
2399 data->partial / UNITS_PER_WORD);
2402 entry_parm = stack_parm;
2405 /* If we didn't decide this parm came in a register, by default it came
2407 else if (entry_parm == NULL)
2408 entry_parm = stack_parm;
2410 /* When an argument is passed in multiple locations, we can't make use
2411 of this information, but we can save some copying if the whole argument
2412 is passed in a single register. */
2413 else if (GET_CODE (entry_parm) == PARALLEL
2414 && data->nominal_mode != BLKmode
2415 && data->passed_mode != BLKmode)
2417 size_t i, len = XVECLEN (entry_parm, 0);
2419 for (i = 0; i < len; i++)
2420 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
2421 && REG_P (XEXP (XVECEXP (entry_parm, 0, i), 0))
2422 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
2423 == data->passed_mode)
2424 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
2426 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
2431 data->entry_parm = entry_parm;
2434 /* A subroutine of assign_parms. Reconstitute any values which were
2435 passed in multiple registers and would fit in a single register. */
2438 assign_parm_remove_parallels (struct assign_parm_data_one *data)
2440 rtx entry_parm = data->entry_parm;
2442 /* Convert the PARALLEL to a REG of the same mode as the parallel.
2443 This can be done with register operations rather than on the
2444 stack, even if we will store the reconstituted parameter on the
2446 if (GET_CODE (entry_parm) == PARALLEL && GET_MODE (entry_parm) != BLKmode)
2448 rtx parmreg = gen_reg_rtx (GET_MODE (entry_parm));
2449 emit_group_store (parmreg, entry_parm, data->passed_type,
2450 GET_MODE_SIZE (GET_MODE (entry_parm)));
2451 entry_parm = parmreg;
2454 data->entry_parm = entry_parm;
2457 /* A subroutine of assign_parms. Adjust DATA->STACK_RTL such that it's
2458 always valid and properly aligned. */
2461 assign_parm_adjust_stack_rtl (struct assign_parm_data_one *data)
2463 rtx stack_parm = data->stack_parm;
2465 /* If we can't trust the parm stack slot to be aligned enough for its
2466 ultimate type, don't use that slot after entry. We'll make another
2467 stack slot, if we need one. */
2469 && ((STRICT_ALIGNMENT
2470 && GET_MODE_ALIGNMENT (data->nominal_mode) > MEM_ALIGN (stack_parm))
2471 || (data->nominal_type
2472 && TYPE_ALIGN (data->nominal_type) > MEM_ALIGN (stack_parm)
2473 && MEM_ALIGN (stack_parm) < PREFERRED_STACK_BOUNDARY)))
2476 /* If parm was passed in memory, and we need to convert it on entry,
2477 don't store it back in that same slot. */
2478 else if (data->entry_parm == stack_parm
2479 && data->nominal_mode != BLKmode
2480 && data->nominal_mode != data->passed_mode)
2483 /* If stack protection is in effect for this function, don't leave any
2484 pointers in their passed stack slots. */
2485 else if (crtl->stack_protect_guard
2486 && (flag_stack_protect == 2
2487 || data->passed_pointer
2488 || POINTER_TYPE_P (data->nominal_type)))
2491 data->stack_parm = stack_parm;
2494 /* A subroutine of assign_parms. Return true if the current parameter
2495 should be stored as a BLKmode in the current frame. */
2498 assign_parm_setup_block_p (struct assign_parm_data_one *data)
2500 if (data->nominal_mode == BLKmode)
2502 if (GET_MODE (data->entry_parm) == BLKmode)
2505 #ifdef BLOCK_REG_PADDING
2506 /* Only assign_parm_setup_block knows how to deal with register arguments
2507 that are padded at the least significant end. */
2508 if (REG_P (data->entry_parm)
2509 && GET_MODE_SIZE (data->promoted_mode) < UNITS_PER_WORD
2510 && (BLOCK_REG_PADDING (data->passed_mode, data->passed_type, 1)
2511 == (BYTES_BIG_ENDIAN ? upward : downward)))
2518 /* A subroutine of assign_parms. Arrange for the parameter to be
2519 present and valid in DATA->STACK_RTL. */
2522 assign_parm_setup_block (struct assign_parm_data_all *all,
2523 tree parm, struct assign_parm_data_one *data)
2525 rtx entry_parm = data->entry_parm;
2526 rtx stack_parm = data->stack_parm;
2528 HOST_WIDE_INT size_stored;
2530 if (GET_CODE (entry_parm) == PARALLEL)
2531 entry_parm = emit_group_move_into_temps (entry_parm);
2533 size = int_size_in_bytes (data->passed_type);
2534 size_stored = CEIL_ROUND (size, UNITS_PER_WORD);
2535 if (stack_parm == 0)
2537 DECL_ALIGN (parm) = MAX (DECL_ALIGN (parm), BITS_PER_WORD);
2538 stack_parm = assign_stack_local (BLKmode, size_stored,
2540 if (GET_MODE_SIZE (GET_MODE (entry_parm)) == size)
2541 PUT_MODE (stack_parm, GET_MODE (entry_parm));
2542 set_mem_attributes (stack_parm, parm, 1);
2545 /* If a BLKmode arrives in registers, copy it to a stack slot. Handle
2546 calls that pass values in multiple non-contiguous locations. */
2547 if (REG_P (entry_parm) || GET_CODE (entry_parm) == PARALLEL)
2551 /* Note that we will be storing an integral number of words.
2552 So we have to be careful to ensure that we allocate an
2553 integral number of words. We do this above when we call
2554 assign_stack_local if space was not allocated in the argument
2555 list. If it was, this will not work if PARM_BOUNDARY is not
2556 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2557 if it becomes a problem. Exception is when BLKmode arrives
2558 with arguments not conforming to word_mode. */
2560 if (data->stack_parm == 0)
2562 else if (GET_CODE (entry_parm) == PARALLEL)
2565 gcc_assert (!size || !(PARM_BOUNDARY % BITS_PER_WORD));
2567 mem = validize_mem (stack_parm);
2569 /* Handle values in multiple non-contiguous locations. */
2570 if (GET_CODE (entry_parm) == PARALLEL)
2572 push_to_sequence2 (all->first_conversion_insn,
2573 all->last_conversion_insn);
2574 emit_group_store (mem, entry_parm, data->passed_type, size);
2575 all->first_conversion_insn = get_insns ();
2576 all->last_conversion_insn = get_last_insn ();
2583 /* If SIZE is that of a mode no bigger than a word, just use
2584 that mode's store operation. */
2585 else if (size <= UNITS_PER_WORD)
2587 enum machine_mode mode
2588 = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
2591 #ifdef BLOCK_REG_PADDING
2592 && (size == UNITS_PER_WORD
2593 || (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2594 != (BYTES_BIG_ENDIAN ? upward : downward)))
2600 /* We are really truncating a word_mode value containing
2601 SIZE bytes into a value of mode MODE. If such an
2602 operation requires no actual instructions, we can refer
2603 to the value directly in mode MODE, otherwise we must
2604 start with the register in word_mode and explicitly
2606 if (TRULY_NOOP_TRUNCATION (size * BITS_PER_UNIT, BITS_PER_WORD))
2607 reg = gen_rtx_REG (mode, REGNO (entry_parm));
2610 reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
2611 reg = convert_to_mode (mode, copy_to_reg (reg), 1);
2613 emit_move_insn (change_address (mem, mode, 0), reg);
2616 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
2617 machine must be aligned to the left before storing
2618 to memory. Note that the previous test doesn't
2619 handle all cases (e.g. SIZE == 3). */
2620 else if (size != UNITS_PER_WORD
2621 #ifdef BLOCK_REG_PADDING
2622 && (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2630 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
2631 rtx reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
2633 x = expand_shift (LSHIFT_EXPR, word_mode, reg,
2634 build_int_cst (NULL_TREE, by),
2636 tem = change_address (mem, word_mode, 0);
2637 emit_move_insn (tem, x);
2640 move_block_from_reg (REGNO (entry_parm), mem,
2641 size_stored / UNITS_PER_WORD);
2644 move_block_from_reg (REGNO (entry_parm), mem,
2645 size_stored / UNITS_PER_WORD);
2647 else if (data->stack_parm == 0)
2649 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2650 emit_block_move (stack_parm, data->entry_parm, GEN_INT (size),
2652 all->first_conversion_insn = get_insns ();
2653 all->last_conversion_insn = get_last_insn ();
2657 data->stack_parm = stack_parm;
2658 SET_DECL_RTL (parm, stack_parm);
2661 /* A subroutine of assign_parms. Allocate a pseudo to hold the current
2662 parameter. Get it there. Perform all ABI specified conversions. */
2665 assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm,
2666 struct assign_parm_data_one *data)
2669 enum machine_mode promoted_nominal_mode;
2670 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (parm));
2671 bool did_conversion = false;
2673 /* Store the parm in a pseudoregister during the function, but we may
2674 need to do it in a wider mode. */
2676 /* This is not really promoting for a call. However we need to be
2677 consistent with assign_parm_find_data_types and expand_expr_real_1. */
2678 promoted_nominal_mode
2679 = promote_mode (data->nominal_type, data->nominal_mode, &unsignedp, 1);
2681 parmreg = gen_reg_rtx (promoted_nominal_mode);
2683 if (!DECL_ARTIFICIAL (parm))
2684 mark_user_reg (parmreg);
2686 /* If this was an item that we received a pointer to,
2687 set DECL_RTL appropriately. */
2688 if (data->passed_pointer)
2690 rtx x = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data->passed_type)), parmreg);
2691 set_mem_attributes (x, parm, 1);
2692 SET_DECL_RTL (parm, x);
2695 SET_DECL_RTL (parm, parmreg);
2697 assign_parm_remove_parallels (data);
2699 /* Copy the value into the register. */
2700 if (data->nominal_mode != data->passed_mode
2701 || promoted_nominal_mode != data->promoted_mode)
2705 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
2706 mode, by the caller. We now have to convert it to
2707 NOMINAL_MODE, if different. However, PARMREG may be in
2708 a different mode than NOMINAL_MODE if it is being stored
2711 If ENTRY_PARM is a hard register, it might be in a register
2712 not valid for operating in its mode (e.g., an odd-numbered
2713 register for a DFmode). In that case, moves are the only
2714 thing valid, so we can't do a convert from there. This
2715 occurs when the calling sequence allow such misaligned
2718 In addition, the conversion may involve a call, which could
2719 clobber parameters which haven't been copied to pseudo
2720 registers yet. Therefore, we must first copy the parm to
2721 a pseudo reg here, and save the conversion until after all
2722 parameters have been moved. */
2724 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
2726 emit_move_insn (tempreg, validize_mem (data->entry_parm));
2728 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2729 tempreg = convert_to_mode (data->nominal_mode, tempreg, unsignedp);
2731 if (GET_CODE (tempreg) == SUBREG
2732 && GET_MODE (tempreg) == data->nominal_mode
2733 && REG_P (SUBREG_REG (tempreg))
2734 && data->nominal_mode == data->passed_mode
2735 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (data->entry_parm)
2736 && GET_MODE_SIZE (GET_MODE (tempreg))
2737 < GET_MODE_SIZE (GET_MODE (data->entry_parm)))
2739 /* The argument is already sign/zero extended, so note it
2741 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
2742 SUBREG_PROMOTED_UNSIGNED_SET (tempreg, unsignedp);
2745 /* TREE_USED gets set erroneously during expand_assignment. */
2746 save_tree_used = TREE_USED (parm);
2747 expand_assignment (parm, make_tree (data->nominal_type, tempreg), false);
2748 TREE_USED (parm) = save_tree_used;
2749 all->first_conversion_insn = get_insns ();
2750 all->last_conversion_insn = get_last_insn ();
2753 did_conversion = true;
2756 emit_move_insn (parmreg, validize_mem (data->entry_parm));
2758 /* If we were passed a pointer but the actual value can safely live
2759 in a register, put it in one. */
2760 if (data->passed_pointer
2761 && TYPE_MODE (TREE_TYPE (parm)) != BLKmode
2762 /* If by-reference argument was promoted, demote it. */
2763 && (TYPE_MODE (TREE_TYPE (parm)) != GET_MODE (DECL_RTL (parm))
2764 || use_register_for_decl (parm)))
2766 /* We can't use nominal_mode, because it will have been set to
2767 Pmode above. We must use the actual mode of the parm. */
2768 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
2769 mark_user_reg (parmreg);
2771 if (GET_MODE (parmreg) != GET_MODE (DECL_RTL (parm)))
2773 rtx tempreg = gen_reg_rtx (GET_MODE (DECL_RTL (parm)));
2774 int unsigned_p = TYPE_UNSIGNED (TREE_TYPE (parm));
2776 push_to_sequence2 (all->first_conversion_insn,
2777 all->last_conversion_insn);
2778 emit_move_insn (tempreg, DECL_RTL (parm));
2779 tempreg = convert_to_mode (GET_MODE (parmreg), tempreg, unsigned_p);
2780 emit_move_insn (parmreg, tempreg);
2781 all->first_conversion_insn = get_insns ();
2782 all->last_conversion_insn = get_last_insn ();
2785 did_conversion = true;
2788 emit_move_insn (parmreg, DECL_RTL (parm));
2790 SET_DECL_RTL (parm, parmreg);
2792 /* STACK_PARM is the pointer, not the parm, and PARMREG is
2794 data->stack_parm = NULL;
2797 /* Mark the register as eliminable if we did no conversion and it was
2798 copied from memory at a fixed offset, and the arg pointer was not
2799 copied to a pseudo-reg. If the arg pointer is a pseudo reg or the
2800 offset formed an invalid address, such memory-equivalences as we
2801 make here would screw up life analysis for it. */
2802 if (data->nominal_mode == data->passed_mode
2804 && data->stack_parm != 0
2805 && MEM_P (data->stack_parm)
2806 && data->locate.offset.var == 0
2807 && reg_mentioned_p (virtual_incoming_args_rtx,
2808 XEXP (data->stack_parm, 0)))
2810 rtx linsn = get_last_insn ();
2813 /* Mark complex types separately. */
2814 if (GET_CODE (parmreg) == CONCAT)
2816 enum machine_mode submode
2817 = GET_MODE_INNER (GET_MODE (parmreg));
2818 int regnor = REGNO (XEXP (parmreg, 0));
2819 int regnoi = REGNO (XEXP (parmreg, 1));
2820 rtx stackr = adjust_address_nv (data->stack_parm, submode, 0);
2821 rtx stacki = adjust_address_nv (data->stack_parm, submode,
2822 GET_MODE_SIZE (submode));
2824 /* Scan backwards for the set of the real and
2826 for (sinsn = linsn; sinsn != 0;
2827 sinsn = prev_nonnote_insn (sinsn))
2829 set = single_set (sinsn);
2833 if (SET_DEST (set) == regno_reg_rtx [regnoi])
2834 set_unique_reg_note (sinsn, REG_EQUIV, stacki);
2835 else if (SET_DEST (set) == regno_reg_rtx [regnor])
2836 set_unique_reg_note (sinsn, REG_EQUIV, stackr);
2839 else if ((set = single_set (linsn)) != 0
2840 && SET_DEST (set) == parmreg)
2841 set_unique_reg_note (linsn, REG_EQUIV, data->stack_parm);
2844 /* For pointer data type, suggest pointer register. */
2845 if (POINTER_TYPE_P (TREE_TYPE (parm)))
2846 mark_reg_pointer (parmreg,
2847 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
2850 /* A subroutine of assign_parms. Allocate stack space to hold the current
2851 parameter. Get it there. Perform all ABI specified conversions. */
2854 assign_parm_setup_stack (struct assign_parm_data_all *all, tree parm,
2855 struct assign_parm_data_one *data)
2857 /* Value must be stored in the stack slot STACK_PARM during function
2859 bool to_conversion = false;
2861 assign_parm_remove_parallels (data);
2863 if (data->promoted_mode != data->nominal_mode)
2865 /* Conversion is required. */
2866 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
2868 emit_move_insn (tempreg, validize_mem (data->entry_parm));
2870 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2871 to_conversion = true;
2873 data->entry_parm = convert_to_mode (data->nominal_mode, tempreg,
2874 TYPE_UNSIGNED (TREE_TYPE (parm)));
2876 if (data->stack_parm)
2877 /* ??? This may need a big-endian conversion on sparc64. */
2879 = adjust_address (data->stack_parm, data->nominal_mode, 0);
2882 if (data->entry_parm != data->stack_parm)
2886 if (data->stack_parm == 0)
2889 = assign_stack_local (GET_MODE (data->entry_parm),
2890 GET_MODE_SIZE (GET_MODE (data->entry_parm)),
2891 TYPE_ALIGN (data->passed_type));
2892 set_mem_attributes (data->stack_parm, parm, 1);
2895 dest = validize_mem (data->stack_parm);
2896 src = validize_mem (data->entry_parm);
2900 /* Use a block move to handle potentially misaligned entry_parm. */
2902 push_to_sequence2 (all->first_conversion_insn,
2903 all->last_conversion_insn);
2904 to_conversion = true;
2906 emit_block_move (dest, src,
2907 GEN_INT (int_size_in_bytes (data->passed_type)),
2911 emit_move_insn (dest, src);
2916 all->first_conversion_insn = get_insns ();
2917 all->last_conversion_insn = get_last_insn ();
2921 SET_DECL_RTL (parm, data->stack_parm);
2924 /* A subroutine of assign_parms. If the ABI splits complex arguments, then
2925 undo the frobbing that we did in assign_parms_augmented_arg_list. */
2928 assign_parms_unsplit_complex (struct assign_parm_data_all *all, tree fnargs)
2931 tree orig_fnargs = all->orig_fnargs;
2933 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm))
2935 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
2936 && targetm.calls.split_complex_arg (TREE_TYPE (parm)))
2938 rtx tmp, real, imag;
2939 enum machine_mode inner = GET_MODE_INNER (DECL_MODE (parm));
2941 real = DECL_RTL (fnargs);
2942 imag = DECL_RTL (TREE_CHAIN (fnargs));
2943 if (inner != GET_MODE (real))
2945 real = gen_lowpart_SUBREG (inner, real);
2946 imag = gen_lowpart_SUBREG (inner, imag);
2949 if (TREE_ADDRESSABLE (parm))
2952 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (parm));
2954 /* split_complex_arg put the real and imag parts in
2955 pseudos. Move them to memory. */
2956 tmp = assign_stack_local (DECL_MODE (parm), size,
2957 TYPE_ALIGN (TREE_TYPE (parm)));
2958 set_mem_attributes (tmp, parm, 1);
2959 rmem = adjust_address_nv (tmp, inner, 0);
2960 imem = adjust_address_nv (tmp, inner, GET_MODE_SIZE (inner));
2961 push_to_sequence2 (all->first_conversion_insn,
2962 all->last_conversion_insn);
2963 emit_move_insn (rmem, real);
2964 emit_move_insn (imem, imag);
2965 all->first_conversion_insn = get_insns ();
2966 all->last_conversion_insn = get_last_insn ();
2970 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
2971 SET_DECL_RTL (parm, tmp);
2973 real = DECL_INCOMING_RTL (fnargs);
2974 imag = DECL_INCOMING_RTL (TREE_CHAIN (fnargs));
2975 if (inner != GET_MODE (real))
2977 real = gen_lowpart_SUBREG (inner, real);
2978 imag = gen_lowpart_SUBREG (inner, imag);
2980 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
2981 set_decl_incoming_rtl (parm, tmp, false);
2982 fnargs = TREE_CHAIN (fnargs);
2986 SET_DECL_RTL (parm, DECL_RTL (fnargs));
2987 set_decl_incoming_rtl (parm, DECL_INCOMING_RTL (fnargs), false);
2989 /* Set MEM_EXPR to the original decl, i.e. to PARM,
2990 instead of the copy of decl, i.e. FNARGS. */
2991 if (DECL_INCOMING_RTL (parm) && MEM_P (DECL_INCOMING_RTL (parm)))
2992 set_mem_expr (DECL_INCOMING_RTL (parm), parm);
2995 fnargs = TREE_CHAIN (fnargs);
2999 /* Assign RTL expressions to the function's parameters. This may involve
3000 copying them into registers and using those registers as the DECL_RTL. */
3003 assign_parms (tree fndecl)
3005 struct assign_parm_data_all all;
3008 crtl->args.internal_arg_pointer
3009 = targetm.calls.internal_arg_pointer ();
3011 assign_parms_initialize_all (&all);
3012 fnargs = assign_parms_augmented_arg_list (&all);
3014 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
3016 struct assign_parm_data_one data;
3018 /* Extract the type of PARM; adjust it according to ABI. */
3019 assign_parm_find_data_types (&all, parm, &data);
3021 /* Early out for errors and void parameters. */
3022 if (data.passed_mode == VOIDmode)
3024 SET_DECL_RTL (parm, const0_rtx);
3025 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
3029 /* Estimate stack alignment from parameter alignment. */
3030 if (SUPPORTS_STACK_ALIGNMENT)
3032 unsigned int align = FUNCTION_ARG_BOUNDARY (data.promoted_mode,
3034 if (TYPE_ALIGN (data.nominal_type) > align)
3035 align = TYPE_ALIGN (data.passed_type);
3036 if (crtl->stack_alignment_estimated < align)
3038 gcc_assert (!crtl->stack_realign_processed);
3039 crtl->stack_alignment_estimated = align;
3043 if (cfun->stdarg && !TREE_CHAIN (parm))
3044 assign_parms_setup_varargs (&all, &data, false);
3046 /* Find out where the parameter arrives in this function. */
3047 assign_parm_find_entry_rtl (&all, &data);
3049 /* Find out where stack space for this parameter might be. */
3050 if (assign_parm_is_stack_parm (&all, &data))
3052 assign_parm_find_stack_rtl (parm, &data);
3053 assign_parm_adjust_entry_rtl (&data);
3056 /* Record permanently how this parm was passed. */
3057 set_decl_incoming_rtl (parm, data.entry_parm, data.passed_pointer);
3059 /* Update info on where next arg arrives in registers. */
3060 FUNCTION_ARG_ADVANCE (all.args_so_far, data.promoted_mode,
3061 data.passed_type, data.named_arg);
3063 assign_parm_adjust_stack_rtl (&data);
3065 if (assign_parm_setup_block_p (&data))
3066 assign_parm_setup_block (&all, parm, &data);
3067 else if (data.passed_pointer || use_register_for_decl (parm))
3068 assign_parm_setup_reg (&all, parm, &data);
3070 assign_parm_setup_stack (&all, parm, &data);
3073 if (targetm.calls.split_complex_arg && fnargs != all.orig_fnargs)
3074 assign_parms_unsplit_complex (&all, fnargs);
3076 /* Output all parameter conversion instructions (possibly including calls)
3077 now that all parameters have been copied out of hard registers. */
3078 emit_insn (all.first_conversion_insn);
3080 /* Estimate reload stack alignment from scalar return mode. */
3081 if (SUPPORTS_STACK_ALIGNMENT)
3083 if (DECL_RESULT (fndecl))
3085 tree type = TREE_TYPE (DECL_RESULT (fndecl));
3086 enum machine_mode mode = TYPE_MODE (type);
3090 && !AGGREGATE_TYPE_P (type))
3092 unsigned int align = GET_MODE_ALIGNMENT (mode);
3093 if (crtl->stack_alignment_estimated < align)
3095 gcc_assert (!crtl->stack_realign_processed);
3096 crtl->stack_alignment_estimated = align;
3102 /* If we are receiving a struct value address as the first argument, set up
3103 the RTL for the function result. As this might require code to convert
3104 the transmitted address to Pmode, we do this here to ensure that possible
3105 preliminary conversions of the address have been emitted already. */
3106 if (all.function_result_decl)
3108 tree result = DECL_RESULT (current_function_decl);
3109 rtx addr = DECL_RTL (all.function_result_decl);
3112 if (DECL_BY_REFERENCE (result))
3116 addr = convert_memory_address (Pmode, addr);
3117 x = gen_rtx_MEM (DECL_MODE (result), addr);
3118 set_mem_attributes (x, result, 1);
3120 SET_DECL_RTL (result, x);
3123 /* We have aligned all the args, so add space for the pretend args. */
3124 crtl->args.pretend_args_size = all.pretend_args_size;
3125 all.stack_args_size.constant += all.extra_pretend_bytes;
3126 crtl->args.size = all.stack_args_size.constant;
3128 /* Adjust function incoming argument size for alignment and
3131 #ifdef REG_PARM_STACK_SPACE
3132 crtl->args.size = MAX (crtl->args.size,
3133 REG_PARM_STACK_SPACE (fndecl));
3136 crtl->args.size = CEIL_ROUND (crtl->args.size,
3137 PARM_BOUNDARY / BITS_PER_UNIT);
3139 #ifdef ARGS_GROW_DOWNWARD
3140 crtl->args.arg_offset_rtx
3141 = (all.stack_args_size.var == 0 ? GEN_INT (-all.stack_args_size.constant)
3142 : expand_expr (size_diffop (all.stack_args_size.var,
3143 size_int (-all.stack_args_size.constant)),
3144 NULL_RTX, VOIDmode, 0));
3146 crtl->args.arg_offset_rtx = ARGS_SIZE_RTX (all.stack_args_size);
3149 /* See how many bytes, if any, of its args a function should try to pop
3152 crtl->args.pops_args = RETURN_POPS_ARGS (fndecl, TREE_TYPE (fndecl),
3155 /* For stdarg.h function, save info about
3156 regs and stack space used by the named args. */
3158 crtl->args.info = all.args_so_far;
3160 /* Set the rtx used for the function return value. Put this in its
3161 own variable so any optimizers that need this information don't have
3162 to include tree.h. Do this here so it gets done when an inlined
3163 function gets output. */
3166 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
3167 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
3169 /* If scalar return value was computed in a pseudo-reg, or was a named
3170 return value that got dumped to the stack, copy that to the hard
3172 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
3174 tree decl_result = DECL_RESULT (fndecl);
3175 rtx decl_rtl = DECL_RTL (decl_result);
3177 if (REG_P (decl_rtl)
3178 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
3179 : DECL_REGISTER (decl_result))
3183 real_decl_rtl = targetm.calls.function_value (TREE_TYPE (decl_result),
3185 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
3186 /* The delay slot scheduler assumes that crtl->return_rtx
3187 holds the hard register containing the return value, not a
3188 temporary pseudo. */
3189 crtl->return_rtx = real_decl_rtl;
3194 /* A subroutine of gimplify_parameters, invoked via walk_tree.
3195 For all seen types, gimplify their sizes. */
3198 gimplify_parm_type (tree *tp, int *walk_subtrees, void *data)
3205 if (POINTER_TYPE_P (t))
3207 else if (TYPE_SIZE (t) && !TREE_CONSTANT (TYPE_SIZE (t))
3208 && !TYPE_SIZES_GIMPLIFIED (t))
3210 gimplify_type_sizes (t, (gimple_seq *) data);
3218 /* Gimplify the parameter list for current_function_decl. This involves
3219 evaluating SAVE_EXPRs of variable sized parameters and generating code
3220 to implement callee-copies reference parameters. Returns a sequence of
3221 statements to add to the beginning of the function. */
3224 gimplify_parameters (void)
3226 struct assign_parm_data_all all;
3228 gimple_seq stmts = NULL;
3230 assign_parms_initialize_all (&all);
3231 fnargs = assign_parms_augmented_arg_list (&all);
3233 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
3235 struct assign_parm_data_one data;
3237 /* Extract the type of PARM; adjust it according to ABI. */
3238 assign_parm_find_data_types (&all, parm, &data);
3240 /* Early out for errors and void parameters. */
3241 if (data.passed_mode == VOIDmode || DECL_SIZE (parm) == NULL)
3244 /* Update info on where next arg arrives in registers. */
3245 FUNCTION_ARG_ADVANCE (all.args_so_far, data.promoted_mode,
3246 data.passed_type, data.named_arg);
3248 /* ??? Once upon a time variable_size stuffed parameter list
3249 SAVE_EXPRs (amongst others) onto a pending sizes list. This
3250 turned out to be less than manageable in the gimple world.
3251 Now we have to hunt them down ourselves. */
3252 walk_tree_without_duplicates (&data.passed_type,
3253 gimplify_parm_type, &stmts);
3255 if (TREE_CODE (DECL_SIZE_UNIT (parm)) != INTEGER_CST)
3257 gimplify_one_sizepos (&DECL_SIZE (parm), &stmts);
3258 gimplify_one_sizepos (&DECL_SIZE_UNIT (parm), &stmts);
3261 if (data.passed_pointer)
3263 tree type = TREE_TYPE (data.passed_type);
3264 if (reference_callee_copied (&all.args_so_far, TYPE_MODE (type),
3265 type, data.named_arg))
3269 /* For constant-sized objects, this is trivial; for
3270 variable-sized objects, we have to play games. */
3271 if (TREE_CODE (DECL_SIZE_UNIT (parm)) == INTEGER_CST
3272 && !(flag_stack_check == GENERIC_STACK_CHECK
3273 && compare_tree_int (DECL_SIZE_UNIT (parm),
3274 STACK_CHECK_MAX_VAR_SIZE) > 0))
3276 local = create_tmp_var (type, get_name (parm));
3277 DECL_IGNORED_P (local) = 0;
3278 /* If PARM was addressable, move that flag over
3279 to the local copy, as its address will be taken,
3281 if (TREE_ADDRESSABLE (parm))
3283 TREE_ADDRESSABLE (parm) = 0;
3284 TREE_ADDRESSABLE (local) = 1;
3289 tree ptr_type, addr;
3291 ptr_type = build_pointer_type (type);
3292 addr = create_tmp_var (ptr_type, get_name (parm));
3293 DECL_IGNORED_P (addr) = 0;
3294 local = build_fold_indirect_ref (addr);
3296 t = built_in_decls[BUILT_IN_ALLOCA];
3297 t = build_call_expr (t, 1, DECL_SIZE_UNIT (parm));
3298 t = fold_convert (ptr_type, t);
3299 t = build2 (MODIFY_EXPR, TREE_TYPE (addr), addr, t);
3300 gimplify_and_add (t, &stmts);
3303 gimplify_assign (local, parm, &stmts);
3305 SET_DECL_VALUE_EXPR (parm, local);
3306 DECL_HAS_VALUE_EXPR_P (parm) = 1;
3314 /* Compute the size and offset from the start of the stacked arguments for a
3315 parm passed in mode PASSED_MODE and with type TYPE.
3317 INITIAL_OFFSET_PTR points to the current offset into the stacked
3320 The starting offset and size for this parm are returned in
3321 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
3322 nonzero, the offset is that of stack slot, which is returned in
3323 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
3324 padding required from the initial offset ptr to the stack slot.
3326 IN_REGS is nonzero if the argument will be passed in registers. It will
3327 never be set if REG_PARM_STACK_SPACE is not defined.
3329 FNDECL is the function in which the argument was defined.
3331 There are two types of rounding that are done. The first, controlled by
3332 FUNCTION_ARG_BOUNDARY, forces the offset from the start of the argument
3333 list to be aligned to the specific boundary (in bits). This rounding
3334 affects the initial and starting offsets, but not the argument size.
3336 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
3337 optionally rounds the size of the parm to PARM_BOUNDARY. The
3338 initial offset is not affected by this rounding, while the size always
3339 is and the starting offset may be. */
3341 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
3342 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
3343 callers pass in the total size of args so far as
3344 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
3347 locate_and_pad_parm (enum machine_mode passed_mode, tree type, int in_regs,
3348 int partial, tree fndecl ATTRIBUTE_UNUSED,
3349 struct args_size *initial_offset_ptr,
3350 struct locate_and_pad_arg_data *locate)
3353 enum direction where_pad;
3354 unsigned int boundary;
3355 int reg_parm_stack_space = 0;
3356 int part_size_in_regs;
3358 #ifdef REG_PARM_STACK_SPACE
3359 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
3361 /* If we have found a stack parm before we reach the end of the
3362 area reserved for registers, skip that area. */
3365 if (reg_parm_stack_space > 0)
3367 if (initial_offset_ptr->var)
3369 initial_offset_ptr->var
3370 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
3371 ssize_int (reg_parm_stack_space));
3372 initial_offset_ptr->constant = 0;
3374 else if (initial_offset_ptr->constant < reg_parm_stack_space)
3375 initial_offset_ptr->constant = reg_parm_stack_space;
3378 #endif /* REG_PARM_STACK_SPACE */
3380 part_size_in_regs = (reg_parm_stack_space == 0 ? partial : 0);
3383 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
3384 where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
3385 boundary = FUNCTION_ARG_BOUNDARY (passed_mode, type);
3386 locate->where_pad = where_pad;
3388 /* Alignment can't exceed MAX_SUPPORTED_STACK_ALIGNMENT. */
3389 if (boundary > MAX_SUPPORTED_STACK_ALIGNMENT)
3390 boundary = MAX_SUPPORTED_STACK_ALIGNMENT;
3392 locate->boundary = boundary;
3394 if (SUPPORTS_STACK_ALIGNMENT)
3396 /* stack_alignment_estimated can't change after stack has been
3398 if (crtl->stack_alignment_estimated < boundary)
3400 if (!crtl->stack_realign_processed)
3401 crtl->stack_alignment_estimated = boundary;
3404 /* If stack is realigned and stack alignment value
3405 hasn't been finalized, it is OK not to increase
3406 stack_alignment_estimated. The bigger alignment
3407 requirement is recorded in stack_alignment_needed
3409 gcc_assert (!crtl->stack_realign_finalized
3410 && crtl->stack_realign_needed);
3415 /* Remember if the outgoing parameter requires extra alignment on the
3416 calling function side. */
3417 if (crtl->stack_alignment_needed < boundary)
3418 crtl->stack_alignment_needed = boundary;
3419 if (crtl->max_used_stack_slot_alignment < crtl->stack_alignment_needed)
3420 crtl->max_used_stack_slot_alignment = crtl->stack_alignment_needed;
3421 if (crtl->preferred_stack_boundary < boundary)
3422 crtl->preferred_stack_boundary = boundary;
3424 #ifdef ARGS_GROW_DOWNWARD
3425 locate->slot_offset.constant = -initial_offset_ptr->constant;
3426 if (initial_offset_ptr->var)
3427 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
3428 initial_offset_ptr->var);
3432 if (where_pad != none
3433 && (!host_integerp (sizetree, 1)
3434 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
3435 s2 = round_up (s2, PARM_BOUNDARY / BITS_PER_UNIT);
3436 SUB_PARM_SIZE (locate->slot_offset, s2);
3439 locate->slot_offset.constant += part_size_in_regs;
3442 #ifdef REG_PARM_STACK_SPACE
3443 || REG_PARM_STACK_SPACE (fndecl) > 0
3446 pad_to_arg_alignment (&locate->slot_offset, boundary,
3447 &locate->alignment_pad);
3449 locate->size.constant = (-initial_offset_ptr->constant
3450 - locate->slot_offset.constant);
3451 if (initial_offset_ptr->var)
3452 locate->size.var = size_binop (MINUS_EXPR,
3453 size_binop (MINUS_EXPR,
3455 initial_offset_ptr->var),
3456 locate->slot_offset.var);
3458 /* Pad_below needs the pre-rounded size to know how much to pad
3460 locate->offset = locate->slot_offset;
3461 if (where_pad == downward)
3462 pad_below (&locate->offset, passed_mode, sizetree);
3464 #else /* !ARGS_GROW_DOWNWARD */
3466 #ifdef REG_PARM_STACK_SPACE
3467 || REG_PARM_STACK_SPACE (fndecl) > 0
3470 pad_to_arg_alignment (initial_offset_ptr, boundary,
3471 &locate->alignment_pad);
3472 locate->slot_offset = *initial_offset_ptr;
3474 #ifdef PUSH_ROUNDING
3475 if (passed_mode != BLKmode)
3476 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
3479 /* Pad_below needs the pre-rounded size to know how much to pad below
3480 so this must be done before rounding up. */
3481 locate->offset = locate->slot_offset;
3482 if (where_pad == downward)
3483 pad_below (&locate->offset, passed_mode, sizetree);
3485 if (where_pad != none
3486 && (!host_integerp (sizetree, 1)
3487 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
3488 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3490 ADD_PARM_SIZE (locate->size, sizetree);
3492 locate->size.constant -= part_size_in_regs;
3493 #endif /* ARGS_GROW_DOWNWARD */
3495 #ifdef FUNCTION_ARG_OFFSET
3496 locate->offset.constant += FUNCTION_ARG_OFFSET (passed_mode, type);
3500 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
3501 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
3504 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
3505 struct args_size *alignment_pad)
3507 tree save_var = NULL_TREE;
3508 HOST_WIDE_INT save_constant = 0;
3509 int boundary_in_bytes = boundary / BITS_PER_UNIT;
3510 HOST_WIDE_INT sp_offset = STACK_POINTER_OFFSET;
3512 #ifdef SPARC_STACK_BOUNDARY_HACK
3513 /* ??? The SPARC port may claim a STACK_BOUNDARY higher than
3514 the real alignment of %sp. However, when it does this, the
3515 alignment of %sp+STACK_POINTER_OFFSET is STACK_BOUNDARY. */
3516 if (SPARC_STACK_BOUNDARY_HACK)
3520 if (boundary > PARM_BOUNDARY)
3522 save_var = offset_ptr->var;
3523 save_constant = offset_ptr->constant;
3526 alignment_pad->var = NULL_TREE;
3527 alignment_pad->constant = 0;
3529 if (boundary > BITS_PER_UNIT)
3531 if (offset_ptr->var)
3533 tree sp_offset_tree = ssize_int (sp_offset);
3534 tree offset = size_binop (PLUS_EXPR,
3535 ARGS_SIZE_TREE (*offset_ptr),
3537 #ifdef ARGS_GROW_DOWNWARD
3538 tree rounded = round_down (offset, boundary / BITS_PER_UNIT);
3540 tree rounded = round_up (offset, boundary / BITS_PER_UNIT);
3543 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
3544 /* ARGS_SIZE_TREE includes constant term. */
3545 offset_ptr->constant = 0;
3546 if (boundary > PARM_BOUNDARY)
3547 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
3552 offset_ptr->constant = -sp_offset +
3553 #ifdef ARGS_GROW_DOWNWARD
3554 FLOOR_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
3556 CEIL_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
3558 if (boundary > PARM_BOUNDARY)
3559 alignment_pad->constant = offset_ptr->constant - save_constant;
3565 pad_below (struct args_size *offset_ptr, enum machine_mode passed_mode, tree sizetree)
3567 if (passed_mode != BLKmode)
3569 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
3570 offset_ptr->constant
3571 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
3572 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
3573 - GET_MODE_SIZE (passed_mode));
3577 if (TREE_CODE (sizetree) != INTEGER_CST
3578 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
3580 /* Round the size up to multiple of PARM_BOUNDARY bits. */
3581 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3583 ADD_PARM_SIZE (*offset_ptr, s2);
3584 SUB_PARM_SIZE (*offset_ptr, sizetree);
3590 /* True if register REGNO was alive at a place where `setjmp' was
3591 called and was set more than once or is an argument. Such regs may
3592 be clobbered by `longjmp'. */
3595 regno_clobbered_at_setjmp (bitmap setjmp_crosses, int regno)
3597 /* There appear to be cases where some local vars never reach the
3598 backend but have bogus regnos. */
3599 if (regno >= max_reg_num ())
3602 return ((REG_N_SETS (regno) > 1
3603 || REGNO_REG_SET_P (df_get_live_out (ENTRY_BLOCK_PTR), regno))
3604 && REGNO_REG_SET_P (setjmp_crosses, regno));
3607 /* Walk the tree of blocks describing the binding levels within a
3608 function and warn about variables the might be killed by setjmp or
3609 vfork. This is done after calling flow_analysis before register
3610 allocation since that will clobber the pseudo-regs to hard
3614 setjmp_vars_warning (bitmap setjmp_crosses, tree block)
3618 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
3620 if (TREE_CODE (decl) == VAR_DECL
3621 && DECL_RTL_SET_P (decl)
3622 && REG_P (DECL_RTL (decl))
3623 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
3624 warning (OPT_Wclobbered, "variable %q+D might be clobbered by"
3625 " %<longjmp%> or %<vfork%>", decl);
3628 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = BLOCK_CHAIN (sub))
3629 setjmp_vars_warning (setjmp_crosses, sub);
3632 /* Do the appropriate part of setjmp_vars_warning
3633 but for arguments instead of local variables. */
3636 setjmp_args_warning (bitmap setjmp_crosses)
3639 for (decl = DECL_ARGUMENTS (current_function_decl);
3640 decl; decl = TREE_CHAIN (decl))
3641 if (DECL_RTL (decl) != 0
3642 && REG_P (DECL_RTL (decl))
3643 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
3644 warning (OPT_Wclobbered,
3645 "argument %q+D might be clobbered by %<longjmp%> or %<vfork%>",
3649 /* Generate warning messages for variables live across setjmp. */
3652 generate_setjmp_warnings (void)
3654 bitmap setjmp_crosses = regstat_get_setjmp_crosses ();
3656 if (n_basic_blocks == NUM_FIXED_BLOCKS
3657 || bitmap_empty_p (setjmp_crosses))
3660 setjmp_vars_warning (setjmp_crosses, DECL_INITIAL (current_function_decl));
3661 setjmp_args_warning (setjmp_crosses);
3665 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
3666 and create duplicate blocks. */
3667 /* ??? Need an option to either create block fragments or to create
3668 abstract origin duplicates of a source block. It really depends
3669 on what optimization has been performed. */
3672 reorder_blocks (void)
3674 tree block = DECL_INITIAL (current_function_decl);
3675 VEC(tree,heap) *block_stack;
3677 if (block == NULL_TREE)
3680 block_stack = VEC_alloc (tree, heap, 10);
3682 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
3683 clear_block_marks (block);
3685 /* Prune the old trees away, so that they don't get in the way. */
3686 BLOCK_SUBBLOCKS (block) = NULL_TREE;
3687 BLOCK_CHAIN (block) = NULL_TREE;
3689 /* Recreate the block tree from the note nesting. */
3690 reorder_blocks_1 (get_insns (), block, &block_stack);
3691 BLOCK_SUBBLOCKS (block) = blocks_nreverse (BLOCK_SUBBLOCKS (block));
3693 VEC_free (tree, heap, block_stack);
3696 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
3699 clear_block_marks (tree block)
3703 TREE_ASM_WRITTEN (block) = 0;
3704 clear_block_marks (BLOCK_SUBBLOCKS (block));
3705 block = BLOCK_CHAIN (block);
3710 reorder_blocks_1 (rtx insns, tree current_block, VEC(tree,heap) **p_block_stack)
3714 for (insn = insns; insn; insn = NEXT_INSN (insn))
3718 if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_BEG)
3720 tree block = NOTE_BLOCK (insn);
3723 origin = (BLOCK_FRAGMENT_ORIGIN (block)
3724 ? BLOCK_FRAGMENT_ORIGIN (block)
3727 /* If we have seen this block before, that means it now
3728 spans multiple address regions. Create a new fragment. */
3729 if (TREE_ASM_WRITTEN (block))
3731 tree new_block = copy_node (block);
3733 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
3734 BLOCK_FRAGMENT_CHAIN (new_block)
3735 = BLOCK_FRAGMENT_CHAIN (origin);
3736 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
3738 NOTE_BLOCK (insn) = new_block;
3742 BLOCK_SUBBLOCKS (block) = 0;
3743 TREE_ASM_WRITTEN (block) = 1;
3744 /* When there's only one block for the entire function,
3745 current_block == block and we mustn't do this, it
3746 will cause infinite recursion. */
3747 if (block != current_block)
3749 if (block != origin)
3750 gcc_assert (BLOCK_SUPERCONTEXT (origin) == current_block);
3752 BLOCK_SUPERCONTEXT (block) = current_block;
3753 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
3754 BLOCK_SUBBLOCKS (current_block) = block;
3755 current_block = origin;
3757 VEC_safe_push (tree, heap, *p_block_stack, block);
3759 else if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_END)
3761 NOTE_BLOCK (insn) = VEC_pop (tree, *p_block_stack);
3762 BLOCK_SUBBLOCKS (current_block)
3763 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block));
3764 current_block = BLOCK_SUPERCONTEXT (current_block);
3770 /* Reverse the order of elements in the chain T of blocks,
3771 and return the new head of the chain (old last element). */
3774 blocks_nreverse (tree t)
3776 tree prev = 0, decl, next;
3777 for (decl = t; decl; decl = next)
3779 next = BLOCK_CHAIN (decl);
3780 BLOCK_CHAIN (decl) = prev;
3786 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
3787 non-NULL, list them all into VECTOR, in a depth-first preorder
3788 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
3792 all_blocks (tree block, tree *vector)
3798 TREE_ASM_WRITTEN (block) = 0;
3800 /* Record this block. */
3802 vector[n_blocks] = block;
3806 /* Record the subblocks, and their subblocks... */
3807 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
3808 vector ? vector + n_blocks : 0);
3809 block = BLOCK_CHAIN (block);
3815 /* Return a vector containing all the blocks rooted at BLOCK. The
3816 number of elements in the vector is stored in N_BLOCKS_P. The
3817 vector is dynamically allocated; it is the caller's responsibility
3818 to call `free' on the pointer returned. */
3821 get_block_vector (tree block, int *n_blocks_p)
3825 *n_blocks_p = all_blocks (block, NULL);
3826 block_vector = XNEWVEC (tree, *n_blocks_p);
3827 all_blocks (block, block_vector);
3829 return block_vector;
3832 static GTY(()) int next_block_index = 2;
3834 /* Set BLOCK_NUMBER for all the blocks in FN. */
3837 number_blocks (tree fn)
3843 /* For SDB and XCOFF debugging output, we start numbering the blocks
3844 from 1 within each function, rather than keeping a running
3846 #if defined (SDB_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
3847 if (write_symbols == SDB_DEBUG || write_symbols == XCOFF_DEBUG)
3848 next_block_index = 1;
3851 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
3853 /* The top-level BLOCK isn't numbered at all. */
3854 for (i = 1; i < n_blocks; ++i)
3855 /* We number the blocks from two. */
3856 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
3858 free (block_vector);
3863 /* If VAR is present in a subblock of BLOCK, return the subblock. */
3866 debug_find_var_in_block_tree (tree var, tree block)
3870 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
3874 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
3876 tree ret = debug_find_var_in_block_tree (var, t);
3884 /* Keep track of whether we're in a dummy function context. If we are,
3885 we don't want to invoke the set_current_function hook, because we'll
3886 get into trouble if the hook calls target_reinit () recursively or
3887 when the initial initialization is not yet complete. */
3889 static bool in_dummy_function;
3891 /* Invoke the target hook when setting cfun. Update the optimization options
3892 if the function uses different options than the default. */
3895 invoke_set_current_function_hook (tree fndecl)
3897 if (!in_dummy_function)
3899 tree opts = ((fndecl)
3900 ? DECL_FUNCTION_SPECIFIC_OPTIMIZATION (fndecl)
3901 : optimization_default_node);
3904 opts = optimization_default_node;
3906 /* Change optimization options if needed. */
3907 if (optimization_current_node != opts)
3909 optimization_current_node = opts;
3910 cl_optimization_restore (TREE_OPTIMIZATION (opts));
3913 targetm.set_current_function (fndecl);
3917 /* cfun should never be set directly; use this function. */
3920 set_cfun (struct function *new_cfun)
3922 if (cfun != new_cfun)
3925 invoke_set_current_function_hook (new_cfun ? new_cfun->decl : NULL_TREE);
3929 /* Initialized with NOGC, making this poisonous to the garbage collector. */
3931 static VEC(function_p,heap) *cfun_stack;
3933 /* Push the current cfun onto the stack, and set cfun to new_cfun. */
3936 push_cfun (struct function *new_cfun)
3938 VEC_safe_push (function_p, heap, cfun_stack, cfun);
3939 set_cfun (new_cfun);
3942 /* Pop cfun from the stack. */
3947 struct function *new_cfun = VEC_pop (function_p, cfun_stack);
3948 set_cfun (new_cfun);
3951 /* Return value of funcdef and increase it. */
3953 get_next_funcdef_no (void)
3955 return funcdef_no++;
3958 /* Allocate a function structure for FNDECL and set its contents
3959 to the defaults. Set cfun to the newly-allocated object.
3960 Some of the helper functions invoked during initialization assume
3961 that cfun has already been set. Therefore, assign the new object
3962 directly into cfun and invoke the back end hook explicitly at the
3963 very end, rather than initializing a temporary and calling set_cfun
3966 ABSTRACT_P is true if this is a function that will never be seen by
3967 the middle-end. Such functions are front-end concepts (like C++
3968 function templates) that do not correspond directly to functions
3969 placed in object files. */
3972 allocate_struct_function (tree fndecl, bool abstract_p)
3975 tree fntype = fndecl ? TREE_TYPE (fndecl) : NULL_TREE;
3977 cfun = GGC_CNEW (struct function);
3979 cfun->function_frequency = FUNCTION_FREQUENCY_NORMAL;
3981 init_eh_for_function ();
3983 if (init_machine_status)
3984 cfun->machine = (*init_machine_status) ();
3986 #ifdef OVERRIDE_ABI_FORMAT
3987 OVERRIDE_ABI_FORMAT (fndecl);
3990 invoke_set_current_function_hook (fndecl);
3992 if (fndecl != NULL_TREE)
3994 DECL_STRUCT_FUNCTION (fndecl) = cfun;
3995 cfun->decl = fndecl;
3996 current_function_funcdef_no = get_next_funcdef_no ();
3998 result = DECL_RESULT (fndecl);
3999 if (!abstract_p && aggregate_value_p (result, fndecl))
4001 #ifdef PCC_STATIC_STRUCT_RETURN
4002 cfun->returns_pcc_struct = 1;
4004 cfun->returns_struct = 1;
4009 && TYPE_ARG_TYPES (fntype) != 0
4010 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
4011 != void_type_node));
4013 /* Assume all registers in stdarg functions need to be saved. */
4014 cfun->va_list_gpr_size = VA_LIST_MAX_GPR_SIZE;
4015 cfun->va_list_fpr_size = VA_LIST_MAX_FPR_SIZE;
4019 /* This is like allocate_struct_function, but pushes a new cfun for FNDECL
4020 instead of just setting it. */
4023 push_struct_function (tree fndecl)
4025 VEC_safe_push (function_p, heap, cfun_stack, cfun);
4026 allocate_struct_function (fndecl, false);
4029 /* Reset cfun, and other non-struct-function variables to defaults as
4030 appropriate for emitting rtl at the start of a function. */
4033 prepare_function_start (void)
4035 gcc_assert (!crtl->emit.x_last_insn);
4037 init_varasm_status ();
4039 default_rtl_profile ();
4041 cse_not_expected = ! optimize;
4043 /* Caller save not needed yet. */
4044 caller_save_needed = 0;
4046 /* We haven't done register allocation yet. */
4049 /* Indicate that we have not instantiated virtual registers yet. */
4050 virtuals_instantiated = 0;
4052 /* Indicate that we want CONCATs now. */
4053 generating_concat_p = 1;
4055 /* Indicate we have no need of a frame pointer yet. */
4056 frame_pointer_needed = 0;
4059 /* Initialize the rtl expansion mechanism so that we can do simple things
4060 like generate sequences. This is used to provide a context during global
4061 initialization of some passes. You must call expand_dummy_function_end
4062 to exit this context. */
4065 init_dummy_function_start (void)
4067 gcc_assert (!in_dummy_function);
4068 in_dummy_function = true;
4069 push_struct_function (NULL_TREE);
4070 prepare_function_start ();
4073 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
4074 and initialize static variables for generating RTL for the statements
4078 init_function_start (tree subr)
4080 if (subr && DECL_STRUCT_FUNCTION (subr))
4081 set_cfun (DECL_STRUCT_FUNCTION (subr));
4083 allocate_struct_function (subr, false);
4084 prepare_function_start ();
4086 /* Warn if this value is an aggregate type,
4087 regardless of which calling convention we are using for it. */
4088 if (AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
4089 warning (OPT_Waggregate_return, "function returns an aggregate");
4092 /* Make sure all values used by the optimization passes have sane
4095 init_function_for_compilation (void)
4099 /* No prologue/epilogue insns yet. Make sure that these vectors are
4101 gcc_assert (VEC_length (int, prologue) == 0);
4102 gcc_assert (VEC_length (int, epilogue) == 0);
4103 gcc_assert (VEC_length (int, sibcall_epilogue) == 0);
4107 struct rtl_opt_pass pass_init_function =
4113 init_function_for_compilation, /* execute */
4116 0, /* static_pass_number */
4118 0, /* properties_required */
4119 0, /* properties_provided */
4120 0, /* properties_destroyed */
4121 0, /* todo_flags_start */
4122 0 /* todo_flags_finish */
4128 expand_main_function (void)
4130 #if (defined(INVOKE__main) \
4131 || (!defined(HAS_INIT_SECTION) \
4132 && !defined(INIT_SECTION_ASM_OP) \
4133 && !defined(INIT_ARRAY_SECTION_ASM_OP)))
4134 emit_library_call (init_one_libfunc (NAME__MAIN), LCT_NORMAL, VOIDmode, 0);
4138 /* Expand code to initialize the stack_protect_guard. This is invoked at
4139 the beginning of a function to be protected. */
4141 #ifndef HAVE_stack_protect_set
4142 # define HAVE_stack_protect_set 0
4143 # define gen_stack_protect_set(x,y) (gcc_unreachable (), NULL_RTX)
4147 stack_protect_prologue (void)
4149 tree guard_decl = targetm.stack_protect_guard ();
4152 /* Avoid expand_expr here, because we don't want guard_decl pulled
4153 into registers unless absolutely necessary. And we know that
4154 crtl->stack_protect_guard is a local stack slot, so this skips
4156 x = validize_mem (DECL_RTL (crtl->stack_protect_guard));
4157 y = validize_mem (DECL_RTL (guard_decl));
4159 /* Allow the target to copy from Y to X without leaking Y into a
4161 if (HAVE_stack_protect_set)
4163 rtx insn = gen_stack_protect_set (x, y);
4171 /* Otherwise do a straight move. */
4172 emit_move_insn (x, y);
4175 /* Expand code to verify the stack_protect_guard. This is invoked at
4176 the end of a function to be protected. */
4178 #ifndef HAVE_stack_protect_test
4179 # define HAVE_stack_protect_test 0
4180 # define gen_stack_protect_test(x, y, z) (gcc_unreachable (), NULL_RTX)
4184 stack_protect_epilogue (void)
4186 tree guard_decl = targetm.stack_protect_guard ();
4187 rtx label = gen_label_rtx ();
4190 /* Avoid expand_expr here, because we don't want guard_decl pulled
4191 into registers unless absolutely necessary. And we know that
4192 crtl->stack_protect_guard is a local stack slot, so this skips
4194 x = validize_mem (DECL_RTL (crtl->stack_protect_guard));
4195 y = validize_mem (DECL_RTL (guard_decl));
4197 /* Allow the target to compare Y with X without leaking either into
4199 switch (HAVE_stack_protect_test != 0)
4202 tmp = gen_stack_protect_test (x, y, label);
4211 emit_cmp_and_jump_insns (x, y, EQ, NULL_RTX, ptr_mode, 1, label);
4215 /* The noreturn predictor has been moved to the tree level. The rtl-level
4216 predictors estimate this branch about 20%, which isn't enough to get
4217 things moved out of line. Since this is the only extant case of adding
4218 a noreturn function at the rtl level, it doesn't seem worth doing ought
4219 except adding the prediction by hand. */
4220 tmp = get_last_insn ();
4222 predict_insn_def (tmp, PRED_NORETURN, TAKEN);
4224 expand_expr_stmt (targetm.stack_protect_fail ());
4228 /* Start the RTL for a new function, and set variables used for
4230 SUBR is the FUNCTION_DECL node.
4231 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
4232 the function's parameters, which must be run at any return statement. */
4235 expand_function_start (tree subr)
4237 /* Make sure volatile mem refs aren't considered
4238 valid operands of arithmetic insns. */
4239 init_recog_no_volatile ();
4243 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
4246 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
4248 /* Make the label for return statements to jump to. Do not special
4249 case machines with special return instructions -- they will be
4250 handled later during jump, ifcvt, or epilogue creation. */
4251 return_label = gen_label_rtx ();
4253 /* Initialize rtx used to return the value. */
4254 /* Do this before assign_parms so that we copy the struct value address
4255 before any library calls that assign parms might generate. */
4257 /* Decide whether to return the value in memory or in a register. */
4258 if (aggregate_value_p (DECL_RESULT (subr), subr))
4260 /* Returning something that won't go in a register. */
4261 rtx value_address = 0;
4263 #ifdef PCC_STATIC_STRUCT_RETURN
4264 if (cfun->returns_pcc_struct)
4266 int size = int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr)));
4267 value_address = assemble_static_space (size);
4272 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 2);
4273 /* Expect to be passed the address of a place to store the value.
4274 If it is passed as an argument, assign_parms will take care of
4278 value_address = gen_reg_rtx (Pmode);
4279 emit_move_insn (value_address, sv);
4284 rtx x = value_address;
4285 if (!DECL_BY_REFERENCE (DECL_RESULT (subr)))
4287 x = gen_rtx_MEM (DECL_MODE (DECL_RESULT (subr)), x);
4288 set_mem_attributes (x, DECL_RESULT (subr), 1);
4290 SET_DECL_RTL (DECL_RESULT (subr), x);
4293 else if (DECL_MODE (DECL_RESULT (subr)) == VOIDmode)
4294 /* If return mode is void, this decl rtl should not be used. */
4295 SET_DECL_RTL (DECL_RESULT (subr), NULL_RTX);
4298 /* Compute the return values into a pseudo reg, which we will copy
4299 into the true return register after the cleanups are done. */
4300 tree return_type = TREE_TYPE (DECL_RESULT (subr));
4301 if (TYPE_MODE (return_type) != BLKmode
4302 && targetm.calls.return_in_msb (return_type))
4303 /* expand_function_end will insert the appropriate padding in
4304 this case. Use the return value's natural (unpadded) mode
4305 within the function proper. */
4306 SET_DECL_RTL (DECL_RESULT (subr),
4307 gen_reg_rtx (TYPE_MODE (return_type)));
4310 /* In order to figure out what mode to use for the pseudo, we
4311 figure out what the mode of the eventual return register will
4312 actually be, and use that. */
4313 rtx hard_reg = hard_function_value (return_type, subr, 0, 1);
4315 /* Structures that are returned in registers are not
4316 aggregate_value_p, so we may see a PARALLEL or a REG. */
4317 if (REG_P (hard_reg))
4318 SET_DECL_RTL (DECL_RESULT (subr),
4319 gen_reg_rtx (GET_MODE (hard_reg)));
4322 gcc_assert (GET_CODE (hard_reg) == PARALLEL);
4323 SET_DECL_RTL (DECL_RESULT (subr), gen_group_rtx (hard_reg));
4327 /* Set DECL_REGISTER flag so that expand_function_end will copy the
4328 result to the real return register(s). */
4329 DECL_REGISTER (DECL_RESULT (subr)) = 1;
4332 /* Initialize rtx for parameters and local variables.
4333 In some cases this requires emitting insns. */
4334 assign_parms (subr);
4336 /* If function gets a static chain arg, store it. */
4337 if (cfun->static_chain_decl)
4339 tree parm = cfun->static_chain_decl;
4340 rtx local = gen_reg_rtx (Pmode);
4342 set_decl_incoming_rtl (parm, static_chain_incoming_rtx, false);
4343 SET_DECL_RTL (parm, local);
4344 mark_reg_pointer (local, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
4346 emit_move_insn (local, static_chain_incoming_rtx);
4349 /* If the function receives a non-local goto, then store the
4350 bits we need to restore the frame pointer. */
4351 if (cfun->nonlocal_goto_save_area)
4356 /* ??? We need to do this save early. Unfortunately here is
4357 before the frame variable gets declared. Help out... */
4358 tree var = TREE_OPERAND (cfun->nonlocal_goto_save_area, 0);
4359 if (!DECL_RTL_SET_P (var))
4362 t_save = build4 (ARRAY_REF, ptr_type_node,
4363 cfun->nonlocal_goto_save_area,
4364 integer_zero_node, NULL_TREE, NULL_TREE);
4365 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
4366 r_save = convert_memory_address (Pmode, r_save);
4368 emit_move_insn (r_save, targetm.builtin_setjmp_frame_value ());
4369 update_nonlocal_goto_save_area ();
4372 /* The following was moved from init_function_start.
4373 The move is supposed to make sdb output more accurate. */
4374 /* Indicate the beginning of the function body,
4375 as opposed to parm setup. */
4376 emit_note (NOTE_INSN_FUNCTION_BEG);
4378 gcc_assert (NOTE_P (get_last_insn ()));
4380 parm_birth_insn = get_last_insn ();
4385 PROFILE_HOOK (current_function_funcdef_no);
4389 /* After the display initializations is where the stack checking
4391 if(flag_stack_check)
4392 stack_check_probe_note = emit_note (NOTE_INSN_DELETED);
4394 /* Make sure there is a line number after the function entry setup code. */
4395 force_next_line_note ();
4398 /* Undo the effects of init_dummy_function_start. */
4400 expand_dummy_function_end (void)
4402 gcc_assert (in_dummy_function);
4404 /* End any sequences that failed to be closed due to syntax errors. */
4405 while (in_sequence_p ())
4408 /* Outside function body, can't compute type's actual size
4409 until next function's body starts. */
4411 free_after_parsing (cfun);
4412 free_after_compilation (cfun);
4414 in_dummy_function = false;
4417 /* Call DOIT for each hard register used as a return value from
4418 the current function. */
4421 diddle_return_value (void (*doit) (rtx, void *), void *arg)
4423 rtx outgoing = crtl->return_rtx;
4428 if (REG_P (outgoing))
4429 (*doit) (outgoing, arg);
4430 else if (GET_CODE (outgoing) == PARALLEL)
4434 for (i = 0; i < XVECLEN (outgoing, 0); i++)
4436 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
4438 if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
4445 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
4451 clobber_return_register (void)
4453 diddle_return_value (do_clobber_return_reg, NULL);
4455 /* In case we do use pseudo to return value, clobber it too. */
4456 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
4458 tree decl_result = DECL_RESULT (current_function_decl);
4459 rtx decl_rtl = DECL_RTL (decl_result);
4460 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
4462 do_clobber_return_reg (decl_rtl, NULL);
4468 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
4474 use_return_register (void)
4476 diddle_return_value (do_use_return_reg, NULL);
4479 /* Possibly warn about unused parameters. */
4481 do_warn_unused_parameter (tree fn)
4485 for (decl = DECL_ARGUMENTS (fn);
4486 decl; decl = TREE_CHAIN (decl))
4487 if (!TREE_USED (decl) && TREE_CODE (decl) == PARM_DECL
4488 && DECL_NAME (decl) && !DECL_ARTIFICIAL (decl)
4489 && !TREE_NO_WARNING (decl))
4490 warning (OPT_Wunused_parameter, "unused parameter %q+D", decl);
4493 static GTY(()) rtx initial_trampoline;
4495 /* Generate RTL for the end of the current function. */
4498 expand_function_end (void)
4502 /* If arg_pointer_save_area was referenced only from a nested
4503 function, we will not have initialized it yet. Do that now. */
4504 if (arg_pointer_save_area && ! crtl->arg_pointer_save_area_init)
4505 get_arg_pointer_save_area ();
4507 /* If we are doing generic stack checking and this function makes calls,
4508 do a stack probe at the start of the function to ensure we have enough
4509 space for another stack frame. */
4510 if (flag_stack_check == GENERIC_STACK_CHECK)
4514 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
4518 probe_stack_range (STACK_OLD_CHECK_PROTECT,
4519 GEN_INT (STACK_CHECK_MAX_FRAME_SIZE));
4522 emit_insn_before (seq, stack_check_probe_note);
4527 /* End any sequences that failed to be closed due to syntax errors. */
4528 while (in_sequence_p ())
4531 clear_pending_stack_adjust ();
4532 do_pending_stack_adjust ();
4534 /* Output a linenumber for the end of the function.
4535 SDB depends on this. */
4536 force_next_line_note ();
4537 set_curr_insn_source_location (input_location);
4539 /* Before the return label (if any), clobber the return
4540 registers so that they are not propagated live to the rest of
4541 the function. This can only happen with functions that drop
4542 through; if there had been a return statement, there would
4543 have either been a return rtx, or a jump to the return label.
4545 We delay actual code generation after the current_function_value_rtx
4547 clobber_after = get_last_insn ();
4549 /* Output the label for the actual return from the function. */
4550 emit_label (return_label);
4552 if (USING_SJLJ_EXCEPTIONS)
4554 /* Let except.c know where it should emit the call to unregister
4555 the function context for sjlj exceptions. */
4556 if (flag_exceptions)
4557 sjlj_emit_function_exit_after (get_last_insn ());
4561 /* We want to ensure that instructions that may trap are not
4562 moved into the epilogue by scheduling, because we don't
4563 always emit unwind information for the epilogue. */
4564 if (flag_non_call_exceptions)
4565 emit_insn (gen_blockage ());
4568 /* If this is an implementation of throw, do what's necessary to
4569 communicate between __builtin_eh_return and the epilogue. */
4570 expand_eh_return ();
4572 /* If scalar return value was computed in a pseudo-reg, or was a named
4573 return value that got dumped to the stack, copy that to the hard
4575 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
4577 tree decl_result = DECL_RESULT (current_function_decl);
4578 rtx decl_rtl = DECL_RTL (decl_result);
4580 if (REG_P (decl_rtl)
4581 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
4582 : DECL_REGISTER (decl_result))
4584 rtx real_decl_rtl = crtl->return_rtx;
4586 /* This should be set in assign_parms. */
4587 gcc_assert (REG_FUNCTION_VALUE_P (real_decl_rtl));
4589 /* If this is a BLKmode structure being returned in registers,
4590 then use the mode computed in expand_return. Note that if
4591 decl_rtl is memory, then its mode may have been changed,
4592 but that crtl->return_rtx has not. */
4593 if (GET_MODE (real_decl_rtl) == BLKmode)
4594 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
4596 /* If a non-BLKmode return value should be padded at the least
4597 significant end of the register, shift it left by the appropriate
4598 amount. BLKmode results are handled using the group load/store
4600 if (TYPE_MODE (TREE_TYPE (decl_result)) != BLKmode
4601 && targetm.calls.return_in_msb (TREE_TYPE (decl_result)))
4603 emit_move_insn (gen_rtx_REG (GET_MODE (decl_rtl),
4604 REGNO (real_decl_rtl)),
4606 shift_return_value (GET_MODE (decl_rtl), true, real_decl_rtl);
4608 /* If a named return value dumped decl_return to memory, then
4609 we may need to re-do the PROMOTE_MODE signed/unsigned
4611 else if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
4613 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
4615 if (targetm.calls.promote_function_return (TREE_TYPE (current_function_decl)))
4616 promote_mode (TREE_TYPE (decl_result), GET_MODE (decl_rtl),
4619 convert_move (real_decl_rtl, decl_rtl, unsignedp);
4621 else if (GET_CODE (real_decl_rtl) == PARALLEL)
4623 /* If expand_function_start has created a PARALLEL for decl_rtl,
4624 move the result to the real return registers. Otherwise, do
4625 a group load from decl_rtl for a named return. */
4626 if (GET_CODE (decl_rtl) == PARALLEL)
4627 emit_group_move (real_decl_rtl, decl_rtl);
4629 emit_group_load (real_decl_rtl, decl_rtl,
4630 TREE_TYPE (decl_result),
4631 int_size_in_bytes (TREE_TYPE (decl_result)));
4633 /* In the case of complex integer modes smaller than a word, we'll
4634 need to generate some non-trivial bitfield insertions. Do that
4635 on a pseudo and not the hard register. */
4636 else if (GET_CODE (decl_rtl) == CONCAT
4637 && GET_MODE_CLASS (GET_MODE (decl_rtl)) == MODE_COMPLEX_INT
4638 && GET_MODE_BITSIZE (GET_MODE (decl_rtl)) <= BITS_PER_WORD)
4640 int old_generating_concat_p;
4643 old_generating_concat_p = generating_concat_p;
4644 generating_concat_p = 0;
4645 tmp = gen_reg_rtx (GET_MODE (decl_rtl));
4646 generating_concat_p = old_generating_concat_p;
4648 emit_move_insn (tmp, decl_rtl);
4649 emit_move_insn (real_decl_rtl, tmp);
4652 emit_move_insn (real_decl_rtl, decl_rtl);
4656 /* If returning a structure, arrange to return the address of the value
4657 in a place where debuggers expect to find it.
4659 If returning a structure PCC style,
4660 the caller also depends on this value.
4661 And cfun->returns_pcc_struct is not necessarily set. */
4662 if (cfun->returns_struct
4663 || cfun->returns_pcc_struct)
4665 rtx value_address = DECL_RTL (DECL_RESULT (current_function_decl));
4666 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
4669 if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
4670 type = TREE_TYPE (type);
4672 value_address = XEXP (value_address, 0);
4674 outgoing = targetm.calls.function_value (build_pointer_type (type),
4675 current_function_decl, true);
4677 /* Mark this as a function return value so integrate will delete the
4678 assignment and USE below when inlining this function. */
4679 REG_FUNCTION_VALUE_P (outgoing) = 1;
4681 /* The address may be ptr_mode and OUTGOING may be Pmode. */
4682 value_address = convert_memory_address (GET_MODE (outgoing),
4685 emit_move_insn (outgoing, value_address);
4687 /* Show return register used to hold result (in this case the address
4689 crtl->return_rtx = outgoing;
4692 /* Emit the actual code to clobber return register. */
4697 clobber_return_register ();
4698 expand_naked_return ();
4702 emit_insn_after (seq, clobber_after);
4705 /* Output the label for the naked return from the function. */
4706 emit_label (naked_return_label);
4708 /* @@@ This is a kludge. We want to ensure that instructions that
4709 may trap are not moved into the epilogue by scheduling, because
4710 we don't always emit unwind information for the epilogue. */
4711 if (! USING_SJLJ_EXCEPTIONS && flag_non_call_exceptions)
4712 emit_insn (gen_blockage ());
4714 /* If stack protection is enabled for this function, check the guard. */
4715 if (crtl->stack_protect_guard)
4716 stack_protect_epilogue ();
4718 /* If we had calls to alloca, and this machine needs
4719 an accurate stack pointer to exit the function,
4720 insert some code to save and restore the stack pointer. */
4721 if (! EXIT_IGNORE_STACK
4722 && cfun->calls_alloca)
4726 emit_stack_save (SAVE_FUNCTION, &tem, parm_birth_insn);
4727 emit_stack_restore (SAVE_FUNCTION, tem, NULL_RTX);
4730 /* ??? This should no longer be necessary since stupid is no longer with
4731 us, but there are some parts of the compiler (eg reload_combine, and
4732 sh mach_dep_reorg) that still try and compute their own lifetime info
4733 instead of using the general framework. */
4734 use_return_register ();
4738 get_arg_pointer_save_area (void)
4740 rtx ret = arg_pointer_save_area;
4744 ret = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
4745 arg_pointer_save_area = ret;
4748 if (! crtl->arg_pointer_save_area_init)
4752 /* Save the arg pointer at the beginning of the function. The
4753 generated stack slot may not be a valid memory address, so we
4754 have to check it and fix it if necessary. */
4756 emit_move_insn (validize_mem (ret),
4757 crtl->args.internal_arg_pointer);
4761 push_topmost_sequence ();
4762 emit_insn_after (seq, entry_of_function ());
4763 pop_topmost_sequence ();
4769 /* Extend a vector that records the INSN_UIDs of INSNS
4770 (a list of one or more insns). */
4773 record_insns (rtx insns, VEC(int,heap) **vecp)
4777 for (tmp = insns; tmp != NULL_RTX; tmp = NEXT_INSN (tmp))
4778 VEC_safe_push (int, heap, *vecp, INSN_UID (tmp));
4781 /* Set the locator of the insn chain starting at INSN to LOC. */
4783 set_insn_locators (rtx insn, int loc)
4785 while (insn != NULL_RTX)
4788 INSN_LOCATOR (insn) = loc;
4789 insn = NEXT_INSN (insn);
4793 /* Determine how many INSN_UIDs in VEC are part of INSN. Because we can
4794 be running after reorg, SEQUENCE rtl is possible. */
4797 contains (const_rtx insn, VEC(int,heap) **vec)
4801 if (NONJUMP_INSN_P (insn)
4802 && GET_CODE (PATTERN (insn)) == SEQUENCE)
4805 for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
4806 for (j = VEC_length (int, *vec) - 1; j >= 0; --j)
4807 if (INSN_UID (XVECEXP (PATTERN (insn), 0, i))
4808 == VEC_index (int, *vec, j))
4814 for (j = VEC_length (int, *vec) - 1; j >= 0; --j)
4815 if (INSN_UID (insn) == VEC_index (int, *vec, j))
4822 prologue_epilogue_contains (const_rtx insn)
4824 if (contains (insn, &prologue))
4826 if (contains (insn, &epilogue))
4832 sibcall_epilogue_contains (const_rtx insn)
4834 if (sibcall_epilogue)
4835 return contains (insn, &sibcall_epilogue);
4840 /* Insert gen_return at the end of block BB. This also means updating
4841 block_for_insn appropriately. */
4844 emit_return_into_block (basic_block bb)
4846 emit_jump_insn_after (gen_return (), BB_END (bb));
4848 #endif /* HAVE_return */
4850 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
4851 this into place with notes indicating where the prologue ends and where
4852 the epilogue begins. Update the basic block information when possible. */
4855 thread_prologue_and_epilogue_insns (void)
4859 #if defined (HAVE_sibcall_epilogue) || defined (HAVE_epilogue) || defined (HAVE_return) || defined (HAVE_prologue)
4862 #if defined (HAVE_epilogue) || defined(HAVE_return)
4863 rtx epilogue_end = NULL_RTX;
4867 rtl_profile_for_bb (ENTRY_BLOCK_PTR);
4868 #ifdef HAVE_prologue
4872 seq = gen_prologue ();
4875 /* Insert an explicit USE for the frame pointer
4876 if the profiling is on and the frame pointer is required. */
4877 if (crtl->profile && frame_pointer_needed)
4878 emit_use (hard_frame_pointer_rtx);
4880 /* Retain a map of the prologue insns. */
4881 record_insns (seq, &prologue);
4882 emit_note (NOTE_INSN_PROLOGUE_END);
4884 #ifndef PROFILE_BEFORE_PROLOGUE
4885 /* Ensure that instructions are not moved into the prologue when
4886 profiling is on. The call to the profiling routine can be
4887 emitted within the live range of a call-clobbered register. */
4889 emit_insn (gen_blockage ());
4894 set_insn_locators (seq, prologue_locator);
4896 /* Can't deal with multiple successors of the entry block
4897 at the moment. Function should always have at least one
4899 gcc_assert (single_succ_p (ENTRY_BLOCK_PTR));
4901 insert_insn_on_edge (seq, single_succ_edge (ENTRY_BLOCK_PTR));
4906 /* If the exit block has no non-fake predecessors, we don't need
4908 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
4909 if ((e->flags & EDGE_FAKE) == 0)
4914 rtl_profile_for_bb (EXIT_BLOCK_PTR);
4916 if (optimize && HAVE_return)
4918 /* If we're allowed to generate a simple return instruction,
4919 then by definition we don't need a full epilogue. Examine
4920 the block that falls through to EXIT. If it does not
4921 contain any code, examine its predecessors and try to
4922 emit (conditional) return instructions. */
4927 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
4928 if (e->flags & EDGE_FALLTHRU)
4934 /* Verify that there are no active instructions in the last block. */
4935 label = BB_END (last);
4936 while (label && !LABEL_P (label))
4938 if (active_insn_p (label))
4940 label = PREV_INSN (label);
4943 if (BB_HEAD (last) == label && LABEL_P (label))
4947 for (ei2 = ei_start (last->preds); (e = ei_safe_edge (ei2)); )
4949 basic_block bb = e->src;
4952 if (bb == ENTRY_BLOCK_PTR)
4959 if (!JUMP_P (jump) || JUMP_LABEL (jump) != label)
4965 /* If we have an unconditional jump, we can replace that
4966 with a simple return instruction. */
4967 if (simplejump_p (jump))
4969 emit_return_into_block (bb);
4973 /* If we have a conditional jump, we can try to replace
4974 that with a conditional return instruction. */
4975 else if (condjump_p (jump))
4977 if (! redirect_jump (jump, 0, 0))
4983 /* If this block has only one successor, it both jumps
4984 and falls through to the fallthru block, so we can't
4986 if (single_succ_p (bb))
4998 /* Fix up the CFG for the successful change we just made. */
4999 redirect_edge_succ (e, EXIT_BLOCK_PTR);
5002 /* Emit a return insn for the exit fallthru block. Whether
5003 this is still reachable will be determined later. */
5005 emit_barrier_after (BB_END (last));
5006 emit_return_into_block (last);
5007 epilogue_end = BB_END (last);
5008 single_succ_edge (last)->flags &= ~EDGE_FALLTHRU;
5013 /* Find the edge that falls through to EXIT. Other edges may exist
5014 due to RETURN instructions, but those don't need epilogues.
5015 There really shouldn't be a mixture -- either all should have
5016 been converted or none, however... */
5018 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5019 if (e->flags & EDGE_FALLTHRU)
5024 #ifdef HAVE_epilogue
5028 epilogue_end = emit_note (NOTE_INSN_EPILOGUE_BEG);
5029 seq = gen_epilogue ();
5030 emit_jump_insn (seq);
5032 /* Retain a map of the epilogue insns. */
5033 record_insns (seq, &epilogue);
5034 set_insn_locators (seq, epilogue_locator);
5039 insert_insn_on_edge (seq, e);
5047 if (! next_active_insn (BB_END (e->src)))
5049 /* We have a fall-through edge to the exit block, the source is not
5050 at the end of the function, and there will be an assembler epilogue
5051 at the end of the function.
5052 We can't use force_nonfallthru here, because that would try to
5053 use return. Inserting a jump 'by hand' is extremely messy, so
5054 we take advantage of cfg_layout_finalize using
5055 fixup_fallthru_exit_predecessor. */
5056 cfg_layout_initialize (0);
5057 FOR_EACH_BB (cur_bb)
5058 if (cur_bb->index >= NUM_FIXED_BLOCKS
5059 && cur_bb->next_bb->index >= NUM_FIXED_BLOCKS)
5060 cur_bb->aux = cur_bb->next_bb;
5061 cfg_layout_finalize ();
5064 default_rtl_profile ();
5068 commit_edge_insertions ();
5070 /* The epilogue insns we inserted may cause the exit edge to no longer
5072 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5074 if (((e->flags & EDGE_FALLTHRU) != 0)
5075 && returnjump_p (BB_END (e->src)))
5076 e->flags &= ~EDGE_FALLTHRU;
5080 #ifdef HAVE_sibcall_epilogue
5081 /* Emit sibling epilogues before any sibling call sites. */
5082 for (ei = ei_start (EXIT_BLOCK_PTR->preds); (e = ei_safe_edge (ei)); )
5084 basic_block bb = e->src;
5085 rtx insn = BB_END (bb);
5088 || ! SIBLING_CALL_P (insn))
5095 emit_insn (gen_sibcall_epilogue ());
5099 /* Retain a map of the epilogue insns. Used in life analysis to
5100 avoid getting rid of sibcall epilogue insns. Do this before we
5101 actually emit the sequence. */
5102 record_insns (seq, &sibcall_epilogue);
5103 set_insn_locators (seq, epilogue_locator);
5105 emit_insn_before (seq, insn);
5110 #ifdef HAVE_epilogue
5115 /* Similarly, move any line notes that appear after the epilogue.
5116 There is no need, however, to be quite so anal about the existence
5117 of such a note. Also possibly move
5118 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
5120 for (insn = epilogue_end; insn; insn = next)
5122 next = NEXT_INSN (insn);
5124 && (NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG))
5125 reorder_insns (insn, insn, PREV_INSN (epilogue_end));
5130 /* Threading the prologue and epilogue changes the artificial refs
5131 in the entry and exit blocks. */
5132 epilogue_completed = 1;
5133 df_update_entry_exit_and_calls ();
5136 /* Reposition the prologue-end and epilogue-begin notes after instruction
5137 scheduling and delayed branch scheduling. */
5140 reposition_prologue_and_epilogue_notes (void)
5142 #if defined (HAVE_prologue) || defined (HAVE_epilogue)
5143 rtx insn, last, note;
5146 if ((len = VEC_length (int, prologue)) > 0)
5150 /* Scan from the beginning until we reach the last prologue insn.
5151 We apparently can't depend on basic_block_{head,end} after
5153 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
5157 if (NOTE_KIND (insn) == NOTE_INSN_PROLOGUE_END)
5160 else if (contains (insn, &prologue))
5170 /* Find the prologue-end note if we haven't already, and
5171 move it to just after the last prologue insn. */
5174 for (note = last; (note = NEXT_INSN (note));)
5176 && NOTE_KIND (note) == NOTE_INSN_PROLOGUE_END)
5180 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
5182 last = NEXT_INSN (last);
5183 reorder_insns (note, note, last);
5187 if ((len = VEC_length (int, epilogue)) > 0)
5191 /* Scan from the end until we reach the first epilogue insn.
5192 We apparently can't depend on basic_block_{head,end} after
5194 for (insn = get_last_insn (); insn; insn = PREV_INSN (insn))
5198 if (NOTE_KIND (insn) == NOTE_INSN_EPILOGUE_BEG)
5201 else if (contains (insn, &epilogue))
5211 /* Find the epilogue-begin note if we haven't already, and
5212 move it to just before the first epilogue insn. */
5215 for (note = insn; (note = PREV_INSN (note));)
5217 && NOTE_KIND (note) == NOTE_INSN_EPILOGUE_BEG)
5221 if (PREV_INSN (last) != note)
5222 reorder_insns (note, note, PREV_INSN (last));
5225 #endif /* HAVE_prologue or HAVE_epilogue */
5228 /* Returns the name of the current function. */
5230 current_function_name (void)
5232 return lang_hooks.decl_printable_name (cfun->decl, 2);
5235 /* Returns the raw (mangled) name of the current function. */
5237 current_function_assembler_name (void)
5239 return IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (cfun->decl));
5244 rest_of_handle_check_leaf_regs (void)
5246 #ifdef LEAF_REGISTERS
5247 current_function_uses_only_leaf_regs
5248 = optimize > 0 && only_leaf_regs_used () && leaf_function_p ();
5253 /* Insert a TYPE into the used types hash table of CFUN. */
5255 used_types_insert_helper (tree type, struct function *func)
5257 if (type != NULL && func != NULL)
5261 if (func->used_types_hash == NULL)
5262 func->used_types_hash = htab_create_ggc (37, htab_hash_pointer,
5263 htab_eq_pointer, NULL);
5264 slot = htab_find_slot (func->used_types_hash, type, INSERT);
5270 /* Given a type, insert it into the used hash table in cfun. */
5272 used_types_insert (tree t)
5274 while (POINTER_TYPE_P (t) || TREE_CODE (t) == ARRAY_TYPE)
5276 t = TYPE_MAIN_VARIANT (t);
5277 if (debug_info_level > DINFO_LEVEL_NONE)
5278 used_types_insert_helper (t, cfun);
5281 struct rtl_opt_pass pass_leaf_regs =
5287 rest_of_handle_check_leaf_regs, /* execute */
5290 0, /* static_pass_number */
5292 0, /* properties_required */
5293 0, /* properties_provided */
5294 0, /* properties_destroyed */
5295 0, /* todo_flags_start */
5296 0 /* todo_flags_finish */
5301 rest_of_handle_thread_prologue_and_epilogue (void)
5304 cleanup_cfg (CLEANUP_EXPENSIVE);
5305 /* On some machines, the prologue and epilogue code, or parts thereof,
5306 can be represented as RTL. Doing so lets us schedule insns between
5307 it and the rest of the code and also allows delayed branch
5308 scheduling to operate in the epilogue. */
5310 thread_prologue_and_epilogue_insns ();
5314 struct rtl_opt_pass pass_thread_prologue_and_epilogue =
5318 "pro_and_epilogue", /* name */
5320 rest_of_handle_thread_prologue_and_epilogue, /* execute */
5323 0, /* static_pass_number */
5324 TV_THREAD_PROLOGUE_AND_EPILOGUE, /* tv_id */
5325 0, /* properties_required */
5326 0, /* properties_provided */
5327 0, /* properties_destroyed */
5328 TODO_verify_flow, /* todo_flags_start */
5331 TODO_df_finish | TODO_verify_rtl_sharing |
5332 TODO_ggc_collect /* todo_flags_finish */
5337 /* This mini-pass fixes fall-out from SSA in asm statements that have
5338 in-out constraints. Say you start with
5341 asm ("": "+mr" (inout));
5344 which is transformed very early to use explicit output and match operands:
5347 asm ("": "=mr" (inout) : "0" (inout));
5350 Or, after SSA and copyprop,
5352 asm ("": "=mr" (inout_2) : "0" (inout_1));
5355 Clearly inout_2 and inout_1 can't be coalesced easily anymore, as
5356 they represent two separate values, so they will get different pseudo
5357 registers during expansion. Then, since the two operands need to match
5358 per the constraints, but use different pseudo registers, reload can
5359 only register a reload for these operands. But reloads can only be
5360 satisfied by hardregs, not by memory, so we need a register for this
5361 reload, just because we are presented with non-matching operands.
5362 So, even though we allow memory for this operand, no memory can be
5363 used for it, just because the two operands don't match. This can
5364 cause reload failures on register-starved targets.
5366 So it's a symptom of reload not being able to use memory for reloads
5367 or, alternatively it's also a symptom of both operands not coming into
5368 reload as matching (in which case the pseudo could go to memory just
5369 fine, as the alternative allows it, and no reload would be necessary).
5370 We fix the latter problem here, by transforming
5372 asm ("": "=mr" (inout_2) : "0" (inout_1));
5377 asm ("": "=mr" (inout_2) : "0" (inout_2)); */
5380 match_asm_constraints_1 (rtx insn, rtx *p_sets, int noutputs)
5383 bool changed = false;
5384 rtx op = SET_SRC (p_sets[0]);
5385 int ninputs = ASM_OPERANDS_INPUT_LENGTH (op);
5386 rtvec inputs = ASM_OPERANDS_INPUT_VEC (op);
5387 bool *output_matched = XALLOCAVEC (bool, noutputs);
5389 memset (output_matched, 0, noutputs * sizeof (bool));
5390 for (i = 0; i < ninputs; i++)
5392 rtx input, output, insns;
5393 const char *constraint = ASM_OPERANDS_INPUT_CONSTRAINT (op, i);
5397 match = strtoul (constraint, &end, 10);
5398 if (end == constraint)
5401 gcc_assert (match < noutputs);
5402 output = SET_DEST (p_sets[match]);
5403 input = RTVEC_ELT (inputs, i);
5404 /* Only do the transformation for pseudos. */
5405 if (! REG_P (output)
5406 || rtx_equal_p (output, input)
5407 || (GET_MODE (input) != VOIDmode
5408 && GET_MODE (input) != GET_MODE (output)))
5411 /* We can't do anything if the output is also used as input,
5412 as we're going to overwrite it. */
5413 for (j = 0; j < ninputs; j++)
5414 if (reg_overlap_mentioned_p (output, RTVEC_ELT (inputs, j)))
5419 /* Avoid changing the same input several times. For
5420 asm ("" : "=mr" (out1), "=mr" (out2) : "0" (in), "1" (in));
5421 only change in once (to out1), rather than changing it
5422 first to out1 and afterwards to out2. */
5425 for (j = 0; j < noutputs; j++)
5426 if (output_matched[j] && input == SET_DEST (p_sets[j]))
5431 output_matched[match] = true;
5434 emit_move_insn (output, input);
5435 insns = get_insns ();
5437 emit_insn_before (insns, insn);
5439 /* Now replace all mentions of the input with output. We can't
5440 just replace the occurrence in inputs[i], as the register might
5441 also be used in some other input (or even in an address of an
5442 output), which would mean possibly increasing the number of
5443 inputs by one (namely 'output' in addition), which might pose
5444 a too complicated problem for reload to solve. E.g. this situation:
5446 asm ("" : "=r" (output), "=m" (input) : "0" (input))
5448 Here 'input' is used in two occurrences as input (once for the
5449 input operand, once for the address in the second output operand).
5450 If we would replace only the occurrence of the input operand (to
5451 make the matching) we would be left with this:
5454 asm ("" : "=r" (output), "=m" (input) : "0" (output))
5456 Now we suddenly have two different input values (containing the same
5457 value, but different pseudos) where we formerly had only one.
5458 With more complicated asms this might lead to reload failures
5459 which wouldn't have happen without this pass. So, iterate over
5460 all operands and replace all occurrences of the register used. */
5461 for (j = 0; j < noutputs; j++)
5462 if (!rtx_equal_p (SET_DEST (p_sets[j]), input)
5463 && reg_overlap_mentioned_p (input, SET_DEST (p_sets[j])))
5464 SET_DEST (p_sets[j]) = replace_rtx (SET_DEST (p_sets[j]),
5466 for (j = 0; j < ninputs; j++)
5467 if (reg_overlap_mentioned_p (input, RTVEC_ELT (inputs, j)))
5468 RTVEC_ELT (inputs, j) = replace_rtx (RTVEC_ELT (inputs, j),
5475 df_insn_rescan (insn);
5479 rest_of_match_asm_constraints (void)
5482 rtx insn, pat, *p_sets;
5485 if (!crtl->has_asm_statement)
5488 df_set_flags (DF_DEFER_INSN_RESCAN);
5491 FOR_BB_INSNS (bb, insn)
5496 pat = PATTERN (insn);
5497 if (GET_CODE (pat) == PARALLEL)
5498 p_sets = &XVECEXP (pat, 0, 0), noutputs = XVECLEN (pat, 0);
5499 else if (GET_CODE (pat) == SET)
5500 p_sets = &PATTERN (insn), noutputs = 1;
5504 if (GET_CODE (*p_sets) == SET
5505 && GET_CODE (SET_SRC (*p_sets)) == ASM_OPERANDS)
5506 match_asm_constraints_1 (insn, p_sets, noutputs);
5510 return TODO_df_finish;
5513 struct rtl_opt_pass pass_match_asm_constraints =
5517 "asmcons", /* name */
5519 rest_of_match_asm_constraints, /* execute */
5522 0, /* static_pass_number */
5524 0, /* properties_required */
5525 0, /* properties_provided */
5526 0, /* properties_destroyed */
5527 0, /* todo_flags_start */
5528 TODO_dump_func /* todo_flags_finish */
5533 #include "gt-function.h"