1 /* Expands front end tree to back end RTL for GCC.
2 Copyright (C) 1987, 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* This file handles the generation of rtl code from tree structure
23 at the level of the function as a whole.
24 It creates the rtl expressions for parameters and auto variables
25 and has full responsibility for allocating stack slots.
27 `expand_function_start' is called at the beginning of a function,
28 before the function body is parsed, and `expand_function_end' is
29 called after parsing the body.
31 Call `assign_stack_local' to allocate a stack slot for a local variable.
32 This is usually done during the RTL generation for the function body,
33 but it can also be done in the reload pass when a pseudo-register does
34 not get a hard register. */
38 #include "coretypes.h"
49 #include "hard-reg-set.h"
50 #include "insn-config.h"
53 #include "basic-block.h"
58 #include "integrate.h"
59 #include "langhooks.h"
61 #include "cfglayout.h"
62 #include "tree-gimple.h"
63 #include "tree-pass.h"
69 /* So we can assign to cfun in this file. */
72 #ifndef LOCAL_ALIGNMENT
73 #define LOCAL_ALIGNMENT(TYPE, ALIGNMENT) ALIGNMENT
76 #ifndef STACK_ALIGNMENT_NEEDED
77 #define STACK_ALIGNMENT_NEEDED 1
80 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
82 /* Some systems use __main in a way incompatible with its use in gcc, in these
83 cases use the macros NAME__MAIN to give a quoted symbol and SYMBOL__MAIN to
84 give the same symbol without quotes for an alternative entry point. You
85 must define both, or neither. */
87 #define NAME__MAIN "__main"
90 /* Round a value to the lowest integer less than it that is a multiple of
91 the required alignment. Avoid using division in case the value is
92 negative. Assume the alignment is a power of two. */
93 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
95 /* Similar, but round to the next highest integer that meets the
97 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
99 /* Nonzero if function being compiled doesn't contain any calls
100 (ignoring the prologue and epilogue). This is set prior to
101 local register allocation and is valid for the remaining
103 int current_function_is_leaf;
105 /* Nonzero if function being compiled doesn't modify the stack pointer
106 (ignoring the prologue and epilogue). This is only valid after
107 pass_stack_ptr_mod has run. */
108 int current_function_sp_is_unchanging;
110 /* Nonzero if the function being compiled is a leaf function which only
111 uses leaf registers. This is valid after reload (specifically after
112 sched2) and is useful only if the port defines LEAF_REGISTERS. */
113 int current_function_uses_only_leaf_regs;
115 /* Nonzero once virtual register instantiation has been done.
116 assign_stack_local uses frame_pointer_rtx when this is nonzero.
117 calls.c:emit_library_call_value_1 uses it to set up
118 post-instantiation libcalls. */
119 int virtuals_instantiated;
121 /* Assign unique numbers to labels generated for profiling, debugging, etc. */
122 static GTY(()) int funcdef_no;
124 /* These variables hold pointers to functions to create and destroy
125 target specific, per-function data structures. */
126 struct machine_function * (*init_machine_status) (void);
128 /* The currently compiled function. */
129 struct function *cfun = 0;
131 /* These arrays record the INSN_UIDs of the prologue and epilogue insns. */
132 static VEC(int,heap) *prologue;
133 static VEC(int,heap) *epilogue;
135 /* Array of INSN_UIDs to hold the INSN_UIDs for each sibcall epilogue
137 static VEC(int,heap) *sibcall_epilogue;
139 /* In order to evaluate some expressions, such as function calls returning
140 structures in memory, we need to temporarily allocate stack locations.
141 We record each allocated temporary in the following structure.
143 Associated with each temporary slot is a nesting level. When we pop up
144 one level, all temporaries associated with the previous level are freed.
145 Normally, all temporaries are freed after the execution of the statement
146 in which they were created. However, if we are inside a ({...}) grouping,
147 the result may be in a temporary and hence must be preserved. If the
148 result could be in a temporary, we preserve it if we can determine which
149 one it is in. If we cannot determine which temporary may contain the
150 result, all temporaries are preserved. A temporary is preserved by
151 pretending it was allocated at the previous nesting level.
153 Automatic variables are also assigned temporary slots, at the nesting
154 level where they are defined. They are marked a "kept" so that
155 free_temp_slots will not free them. */
157 struct temp_slot GTY(())
159 /* Points to next temporary slot. */
160 struct temp_slot *next;
161 /* Points to previous temporary slot. */
162 struct temp_slot *prev;
164 /* The rtx to used to reference the slot. */
166 /* The rtx used to represent the address if not the address of the
167 slot above. May be an EXPR_LIST if multiple addresses exist. */
169 /* The alignment (in bits) of the slot. */
171 /* The size, in units, of the slot. */
173 /* The type of the object in the slot, or zero if it doesn't correspond
174 to a type. We use this to determine whether a slot can be reused.
175 It can be reused if objects of the type of the new slot will always
176 conflict with objects of the type of the old slot. */
178 /* Nonzero if this temporary is currently in use. */
180 /* Nonzero if this temporary has its address taken. */
182 /* Nesting level at which this slot is being used. */
184 /* Nonzero if this should survive a call to free_temp_slots. */
186 /* The offset of the slot from the frame_pointer, including extra space
187 for alignment. This info is for combine_temp_slots. */
188 HOST_WIDE_INT base_offset;
189 /* The size of the slot, including extra space for alignment. This
190 info is for combine_temp_slots. */
191 HOST_WIDE_INT full_size;
194 /* Forward declarations. */
196 static struct temp_slot *find_temp_slot_from_address (rtx);
197 static void pad_to_arg_alignment (struct args_size *, int, struct args_size *);
198 static void pad_below (struct args_size *, enum machine_mode, tree);
199 static void reorder_blocks_1 (rtx, tree, VEC(tree,heap) **);
200 static int all_blocks (tree, tree *);
201 static tree *get_block_vector (tree, int *);
202 extern tree debug_find_var_in_block_tree (tree, tree);
203 /* We always define `record_insns' even if it's not used so that we
204 can always export `prologue_epilogue_contains'. */
205 static void record_insns (rtx, VEC(int,heap) **) ATTRIBUTE_UNUSED;
206 static int contains (const_rtx, VEC(int,heap) **);
208 static void emit_return_into_block (basic_block);
210 #if defined(HAVE_epilogue) && defined(INCOMING_RETURN_ADDR_RTX)
211 static rtx keep_stack_depressed (rtx);
213 static void prepare_function_start (void);
214 static void do_clobber_return_reg (rtx, void *);
215 static void do_use_return_reg (rtx, void *);
216 static void set_insn_locators (rtx, int) ATTRIBUTE_UNUSED;
218 /* Pointer to chain of `struct function' for containing functions. */
219 struct function *outer_function_chain;
221 /* Given a function decl for a containing function,
222 return the `struct function' for it. */
225 find_function_data (tree decl)
229 for (p = outer_function_chain; p; p = p->outer)
236 /* Save the current context for compilation of a nested function.
237 This is called from language-specific code. The caller should use
238 the enter_nested langhook to save any language-specific state,
239 since this function knows only about language-independent
243 push_function_context_to (tree context ATTRIBUTE_UNUSED)
248 allocate_struct_function (NULL, false);
251 p->outer = outer_function_chain;
252 outer_function_chain = p;
254 lang_hooks.function.enter_nested (p);
260 push_function_context (void)
262 push_function_context_to (current_function_decl);
265 /* Restore the last saved context, at the end of a nested function.
266 This function is called from language-specific code. */
269 pop_function_context_from (tree context ATTRIBUTE_UNUSED)
271 struct function *p = outer_function_chain;
274 outer_function_chain = p->outer;
276 current_function_decl = p->decl;
278 lang_hooks.function.leave_nested (p);
280 /* Reset variables that have known state during rtx generation. */
281 virtuals_instantiated = 0;
282 generating_concat_p = 1;
286 pop_function_context (void)
288 pop_function_context_from (current_function_decl);
291 /* Clear out all parts of the state in F that can safely be discarded
292 after the function has been parsed, but not compiled, to let
293 garbage collection reclaim the memory. */
296 free_after_parsing (struct function *f)
298 /* f->expr->forced_labels is used by code generation. */
299 /* f->emit->regno_reg_rtx is used by code generation. */
300 /* f->varasm is used by code generation. */
301 /* f->eh->eh_return_stub_label is used by code generation. */
303 lang_hooks.function.final (f);
306 /* Clear out all parts of the state in F that can safely be discarded
307 after the function has been compiled, to let garbage collection
308 reclaim the memory. */
311 free_after_compilation (struct function *f)
313 VEC_free (int, heap, prologue);
314 VEC_free (int, heap, epilogue);
315 VEC_free (int, heap, sibcall_epilogue);
316 free (rtl.emit.regno_pointer_align);
318 memset (&rtl, 0, sizeof (rtl));
323 f->arg_offset_rtx = NULL;
324 f->return_rtx = NULL;
325 f->internal_arg_pointer = NULL;
328 /* Return size needed for stack frame based on slots so far allocated.
329 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
330 the caller may have to do that. */
333 get_frame_size (void)
335 if (FRAME_GROWS_DOWNWARD)
336 return -frame_offset;
341 /* Issue an error message and return TRUE if frame OFFSET overflows in
342 the signed target pointer arithmetics for function FUNC. Otherwise
346 frame_offset_overflow (HOST_WIDE_INT offset, tree func)
348 unsigned HOST_WIDE_INT size = FRAME_GROWS_DOWNWARD ? -offset : offset;
350 if (size > ((unsigned HOST_WIDE_INT) 1 << (GET_MODE_BITSIZE (Pmode) - 1))
351 /* Leave room for the fixed part of the frame. */
352 - 64 * UNITS_PER_WORD)
354 error ("%Jtotal size of local objects too large", func);
361 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
362 with machine mode MODE.
364 ALIGN controls the amount of alignment for the address of the slot:
365 0 means according to MODE,
366 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
367 -2 means use BITS_PER_UNIT,
368 positive specifies alignment boundary in bits.
370 We do not round to stack_boundary here. */
373 assign_stack_local (enum machine_mode mode, HOST_WIDE_INT size, int align)
376 int bigend_correction = 0;
377 unsigned int alignment;
378 int frame_off, frame_alignment, frame_phase;
385 alignment = BIGGEST_ALIGNMENT;
387 alignment = GET_MODE_ALIGNMENT (mode);
389 /* Allow the target to (possibly) increase the alignment of this
391 type = lang_hooks.types.type_for_mode (mode, 0);
393 alignment = LOCAL_ALIGNMENT (type, alignment);
395 alignment /= BITS_PER_UNIT;
397 else if (align == -1)
399 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
400 size = CEIL_ROUND (size, alignment);
402 else if (align == -2)
403 alignment = 1; /* BITS_PER_UNIT / BITS_PER_UNIT */
405 alignment = align / BITS_PER_UNIT;
407 if (FRAME_GROWS_DOWNWARD)
408 frame_offset -= size;
410 /* Ignore alignment we can't do with expected alignment of the boundary. */
411 if (alignment * BITS_PER_UNIT > PREFERRED_STACK_BOUNDARY)
412 alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
414 if (cfun->stack_alignment_needed < alignment * BITS_PER_UNIT)
415 cfun->stack_alignment_needed = alignment * BITS_PER_UNIT;
417 /* Calculate how many bytes the start of local variables is off from
419 frame_alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
420 frame_off = STARTING_FRAME_OFFSET % frame_alignment;
421 frame_phase = frame_off ? frame_alignment - frame_off : 0;
423 /* Round the frame offset to the specified alignment. The default is
424 to always honor requests to align the stack but a port may choose to
425 do its own stack alignment by defining STACK_ALIGNMENT_NEEDED. */
426 if (STACK_ALIGNMENT_NEEDED
430 /* We must be careful here, since FRAME_OFFSET might be negative and
431 division with a negative dividend isn't as well defined as we might
432 like. So we instead assume that ALIGNMENT is a power of two and
433 use logical operations which are unambiguous. */
434 if (FRAME_GROWS_DOWNWARD)
436 = (FLOOR_ROUND (frame_offset - frame_phase,
437 (unsigned HOST_WIDE_INT) alignment)
441 = (CEIL_ROUND (frame_offset - frame_phase,
442 (unsigned HOST_WIDE_INT) alignment)
446 /* On a big-endian machine, if we are allocating more space than we will use,
447 use the least significant bytes of those that are allocated. */
448 if (BYTES_BIG_ENDIAN && mode != BLKmode && GET_MODE_SIZE (mode) < size)
449 bigend_correction = size - GET_MODE_SIZE (mode);
451 /* If we have already instantiated virtual registers, return the actual
452 address relative to the frame pointer. */
453 if (virtuals_instantiated)
454 addr = plus_constant (frame_pointer_rtx,
456 (frame_offset + bigend_correction
457 + STARTING_FRAME_OFFSET, Pmode));
459 addr = plus_constant (virtual_stack_vars_rtx,
461 (frame_offset + bigend_correction,
464 if (!FRAME_GROWS_DOWNWARD)
465 frame_offset += size;
467 x = gen_rtx_MEM (mode, addr);
468 MEM_NOTRAP_P (x) = 1;
471 = gen_rtx_EXPR_LIST (VOIDmode, x, stack_slot_list);
473 if (frame_offset_overflow (frame_offset, current_function_decl))
479 /* Removes temporary slot TEMP from LIST. */
482 cut_slot_from_list (struct temp_slot *temp, struct temp_slot **list)
485 temp->next->prev = temp->prev;
487 temp->prev->next = temp->next;
491 temp->prev = temp->next = NULL;
494 /* Inserts temporary slot TEMP to LIST. */
497 insert_slot_to_list (struct temp_slot *temp, struct temp_slot **list)
501 (*list)->prev = temp;
506 /* Returns the list of used temp slots at LEVEL. */
508 static struct temp_slot **
509 temp_slots_at_level (int level)
511 if (level >= (int) VEC_length (temp_slot_p, used_temp_slots))
512 VEC_safe_grow_cleared (temp_slot_p, gc, used_temp_slots, level + 1);
514 return &(VEC_address (temp_slot_p, used_temp_slots)[level]);
517 /* Returns the maximal temporary slot level. */
520 max_slot_level (void)
522 if (!used_temp_slots)
525 return VEC_length (temp_slot_p, used_temp_slots) - 1;
528 /* Moves temporary slot TEMP to LEVEL. */
531 move_slot_to_level (struct temp_slot *temp, int level)
533 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
534 insert_slot_to_list (temp, temp_slots_at_level (level));
538 /* Make temporary slot TEMP available. */
541 make_slot_available (struct temp_slot *temp)
543 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
544 insert_slot_to_list (temp, &avail_temp_slots);
549 /* Allocate a temporary stack slot and record it for possible later
552 MODE is the machine mode to be given to the returned rtx.
554 SIZE is the size in units of the space required. We do no rounding here
555 since assign_stack_local will do any required rounding.
557 KEEP is 1 if this slot is to be retained after a call to
558 free_temp_slots. Automatic variables for a block are allocated
559 with this flag. KEEP values of 2 or 3 were needed respectively
560 for variables whose lifetime is controlled by CLEANUP_POINT_EXPRs
561 or for SAVE_EXPRs, but they are now unused.
563 TYPE is the type that will be used for the stack slot. */
566 assign_stack_temp_for_type (enum machine_mode mode, HOST_WIDE_INT size,
570 struct temp_slot *p, *best_p = 0, *selected = NULL, **pp;
573 /* If SIZE is -1 it means that somebody tried to allocate a temporary
574 of a variable size. */
575 gcc_assert (size != -1);
577 /* These are now unused. */
578 gcc_assert (keep <= 1);
581 align = BIGGEST_ALIGNMENT;
583 align = GET_MODE_ALIGNMENT (mode);
586 type = lang_hooks.types.type_for_mode (mode, 0);
589 align = LOCAL_ALIGNMENT (type, align);
591 /* Try to find an available, already-allocated temporary of the proper
592 mode which meets the size and alignment requirements. Choose the
593 smallest one with the closest alignment.
595 If assign_stack_temp is called outside of the tree->rtl expansion,
596 we cannot reuse the stack slots (that may still refer to
597 VIRTUAL_STACK_VARS_REGNUM). */
598 if (!virtuals_instantiated)
600 for (p = avail_temp_slots; p; p = p->next)
602 if (p->align >= align && p->size >= size
603 && GET_MODE (p->slot) == mode
604 && objects_must_conflict_p (p->type, type)
605 && (best_p == 0 || best_p->size > p->size
606 || (best_p->size == p->size && best_p->align > p->align)))
608 if (p->align == align && p->size == size)
611 cut_slot_from_list (selected, &avail_temp_slots);
620 /* Make our best, if any, the one to use. */
624 cut_slot_from_list (selected, &avail_temp_slots);
626 /* If there are enough aligned bytes left over, make them into a new
627 temp_slot so that the extra bytes don't get wasted. Do this only
628 for BLKmode slots, so that we can be sure of the alignment. */
629 if (GET_MODE (best_p->slot) == BLKmode)
631 int alignment = best_p->align / BITS_PER_UNIT;
632 HOST_WIDE_INT rounded_size = CEIL_ROUND (size, alignment);
634 if (best_p->size - rounded_size >= alignment)
636 p = ggc_alloc (sizeof (struct temp_slot));
637 p->in_use = p->addr_taken = 0;
638 p->size = best_p->size - rounded_size;
639 p->base_offset = best_p->base_offset + rounded_size;
640 p->full_size = best_p->full_size - rounded_size;
641 p->slot = adjust_address_nv (best_p->slot, BLKmode, rounded_size);
642 p->align = best_p->align;
644 p->type = best_p->type;
645 insert_slot_to_list (p, &avail_temp_slots);
647 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, p->slot,
650 best_p->size = rounded_size;
651 best_p->full_size = rounded_size;
656 /* If we still didn't find one, make a new temporary. */
659 HOST_WIDE_INT frame_offset_old = frame_offset;
661 p = ggc_alloc (sizeof (struct temp_slot));
663 /* We are passing an explicit alignment request to assign_stack_local.
664 One side effect of that is assign_stack_local will not round SIZE
665 to ensure the frame offset remains suitably aligned.
667 So for requests which depended on the rounding of SIZE, we go ahead
668 and round it now. We also make sure ALIGNMENT is at least
669 BIGGEST_ALIGNMENT. */
670 gcc_assert (mode != BLKmode || align == BIGGEST_ALIGNMENT);
671 p->slot = assign_stack_local (mode,
673 ? CEIL_ROUND (size, (int) align / BITS_PER_UNIT)
679 /* The following slot size computation is necessary because we don't
680 know the actual size of the temporary slot until assign_stack_local
681 has performed all the frame alignment and size rounding for the
682 requested temporary. Note that extra space added for alignment
683 can be either above or below this stack slot depending on which
684 way the frame grows. We include the extra space if and only if it
685 is above this slot. */
686 if (FRAME_GROWS_DOWNWARD)
687 p->size = frame_offset_old - frame_offset;
691 /* Now define the fields used by combine_temp_slots. */
692 if (FRAME_GROWS_DOWNWARD)
694 p->base_offset = frame_offset;
695 p->full_size = frame_offset_old - frame_offset;
699 p->base_offset = frame_offset_old;
700 p->full_size = frame_offset - frame_offset_old;
711 p->level = temp_slot_level;
714 pp = temp_slots_at_level (p->level);
715 insert_slot_to_list (p, pp);
717 /* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
718 slot = gen_rtx_MEM (mode, XEXP (p->slot, 0));
719 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, slot, stack_slot_list);
721 /* If we know the alias set for the memory that will be used, use
722 it. If there's no TYPE, then we don't know anything about the
723 alias set for the memory. */
724 set_mem_alias_set (slot, type ? get_alias_set (type) : 0);
725 set_mem_align (slot, align);
727 /* If a type is specified, set the relevant flags. */
730 MEM_VOLATILE_P (slot) = TYPE_VOLATILE (type);
731 MEM_SET_IN_STRUCT_P (slot, (AGGREGATE_TYPE_P (type)
732 || TREE_CODE (type) == COMPLEX_TYPE));
734 MEM_NOTRAP_P (slot) = 1;
739 /* Allocate a temporary stack slot and record it for possible later
740 reuse. First three arguments are same as in preceding function. */
743 assign_stack_temp (enum machine_mode mode, HOST_WIDE_INT size, int keep)
745 return assign_stack_temp_for_type (mode, size, keep, NULL_TREE);
748 /* Assign a temporary.
749 If TYPE_OR_DECL is a decl, then we are doing it on behalf of the decl
750 and so that should be used in error messages. In either case, we
751 allocate of the given type.
752 KEEP is as for assign_stack_temp.
753 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
754 it is 0 if a register is OK.
755 DONT_PROMOTE is 1 if we should not promote values in register
759 assign_temp (tree type_or_decl, int keep, int memory_required,
760 int dont_promote ATTRIBUTE_UNUSED)
763 enum machine_mode mode;
768 if (DECL_P (type_or_decl))
769 decl = type_or_decl, type = TREE_TYPE (decl);
771 decl = NULL, type = type_or_decl;
773 mode = TYPE_MODE (type);
775 unsignedp = TYPE_UNSIGNED (type);
778 if (mode == BLKmode || memory_required)
780 HOST_WIDE_INT size = int_size_in_bytes (type);
783 /* Zero sized arrays are GNU C extension. Set size to 1 to avoid
784 problems with allocating the stack space. */
788 /* Unfortunately, we don't yet know how to allocate variable-sized
789 temporaries. However, sometimes we can find a fixed upper limit on
790 the size, so try that instead. */
792 size = max_int_size_in_bytes (type);
794 /* The size of the temporary may be too large to fit into an integer. */
795 /* ??? Not sure this should happen except for user silliness, so limit
796 this to things that aren't compiler-generated temporaries. The
797 rest of the time we'll die in assign_stack_temp_for_type. */
798 if (decl && size == -1
799 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST)
801 error ("size of variable %q+D is too large", decl);
805 tmp = assign_stack_temp_for_type (mode, size, keep, type);
811 mode = promote_mode (type, mode, &unsignedp, 0);
814 return gen_reg_rtx (mode);
817 /* Combine temporary stack slots which are adjacent on the stack.
819 This allows for better use of already allocated stack space. This is only
820 done for BLKmode slots because we can be sure that we won't have alignment
821 problems in this case. */
824 combine_temp_slots (void)
826 struct temp_slot *p, *q, *next, *next_q;
829 /* We can't combine slots, because the information about which slot
830 is in which alias set will be lost. */
831 if (flag_strict_aliasing)
834 /* If there are a lot of temp slots, don't do anything unless
835 high levels of optimization. */
836 if (! flag_expensive_optimizations)
837 for (p = avail_temp_slots, num_slots = 0; p; p = p->next, num_slots++)
838 if (num_slots > 100 || (num_slots > 10 && optimize == 0))
841 for (p = avail_temp_slots; p; p = next)
847 if (GET_MODE (p->slot) != BLKmode)
850 for (q = p->next; q; q = next_q)
856 if (GET_MODE (q->slot) != BLKmode)
859 if (p->base_offset + p->full_size == q->base_offset)
861 /* Q comes after P; combine Q into P. */
863 p->full_size += q->full_size;
866 else if (q->base_offset + q->full_size == p->base_offset)
868 /* P comes after Q; combine P into Q. */
870 q->full_size += p->full_size;
875 cut_slot_from_list (q, &avail_temp_slots);
878 /* Either delete P or advance past it. */
880 cut_slot_from_list (p, &avail_temp_slots);
884 /* Find the temp slot corresponding to the object at address X. */
886 static struct temp_slot *
887 find_temp_slot_from_address (rtx x)
893 for (i = max_slot_level (); i >= 0; i--)
894 for (p = *temp_slots_at_level (i); p; p = p->next)
896 if (XEXP (p->slot, 0) == x
898 || (GET_CODE (x) == PLUS
899 && XEXP (x, 0) == virtual_stack_vars_rtx
900 && GET_CODE (XEXP (x, 1)) == CONST_INT
901 && INTVAL (XEXP (x, 1)) >= p->base_offset
902 && INTVAL (XEXP (x, 1)) < p->base_offset + p->full_size))
905 else if (p->address != 0 && GET_CODE (p->address) == EXPR_LIST)
906 for (next = p->address; next; next = XEXP (next, 1))
907 if (XEXP (next, 0) == x)
911 /* If we have a sum involving a register, see if it points to a temp
913 if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 0))
914 && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
916 else if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 1))
917 && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
923 /* Indicate that NEW is an alternate way of referring to the temp slot
924 that previously was known by OLD. */
927 update_temp_slot_address (rtx old, rtx new)
931 if (rtx_equal_p (old, new))
934 p = find_temp_slot_from_address (old);
936 /* If we didn't find one, see if both OLD is a PLUS. If so, and NEW
937 is a register, see if one operand of the PLUS is a temporary
938 location. If so, NEW points into it. Otherwise, if both OLD and
939 NEW are a PLUS and if there is a register in common between them.
940 If so, try a recursive call on those values. */
943 if (GET_CODE (old) != PLUS)
948 update_temp_slot_address (XEXP (old, 0), new);
949 update_temp_slot_address (XEXP (old, 1), new);
952 else if (GET_CODE (new) != PLUS)
955 if (rtx_equal_p (XEXP (old, 0), XEXP (new, 0)))
956 update_temp_slot_address (XEXP (old, 1), XEXP (new, 1));
957 else if (rtx_equal_p (XEXP (old, 1), XEXP (new, 0)))
958 update_temp_slot_address (XEXP (old, 0), XEXP (new, 1));
959 else if (rtx_equal_p (XEXP (old, 0), XEXP (new, 1)))
960 update_temp_slot_address (XEXP (old, 1), XEXP (new, 0));
961 else if (rtx_equal_p (XEXP (old, 1), XEXP (new, 1)))
962 update_temp_slot_address (XEXP (old, 0), XEXP (new, 0));
967 /* Otherwise add an alias for the temp's address. */
968 else if (p->address == 0)
972 if (GET_CODE (p->address) != EXPR_LIST)
973 p->address = gen_rtx_EXPR_LIST (VOIDmode, p->address, NULL_RTX);
975 p->address = gen_rtx_EXPR_LIST (VOIDmode, new, p->address);
979 /* If X could be a reference to a temporary slot, mark the fact that its
980 address was taken. */
983 mark_temp_addr_taken (rtx x)
990 /* If X is not in memory or is at a constant address, it cannot be in
992 if (!MEM_P (x) || CONSTANT_P (XEXP (x, 0)))
995 p = find_temp_slot_from_address (XEXP (x, 0));
1000 /* If X could be a reference to a temporary slot, mark that slot as
1001 belonging to the to one level higher than the current level. If X
1002 matched one of our slots, just mark that one. Otherwise, we can't
1003 easily predict which it is, so upgrade all of them. Kept slots
1004 need not be touched.
1006 This is called when an ({...}) construct occurs and a statement
1007 returns a value in memory. */
1010 preserve_temp_slots (rtx x)
1012 struct temp_slot *p = 0, *next;
1014 /* If there is no result, we still might have some objects whose address
1015 were taken, so we need to make sure they stay around. */
1018 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1023 move_slot_to_level (p, temp_slot_level - 1);
1029 /* If X is a register that is being used as a pointer, see if we have
1030 a temporary slot we know it points to. To be consistent with
1031 the code below, we really should preserve all non-kept slots
1032 if we can't find a match, but that seems to be much too costly. */
1033 if (REG_P (x) && REG_POINTER (x))
1034 p = find_temp_slot_from_address (x);
1036 /* If X is not in memory or is at a constant address, it cannot be in
1037 a temporary slot, but it can contain something whose address was
1039 if (p == 0 && (!MEM_P (x) || CONSTANT_P (XEXP (x, 0))))
1041 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1046 move_slot_to_level (p, temp_slot_level - 1);
1052 /* First see if we can find a match. */
1054 p = find_temp_slot_from_address (XEXP (x, 0));
1058 /* Move everything at our level whose address was taken to our new
1059 level in case we used its address. */
1060 struct temp_slot *q;
1062 if (p->level == temp_slot_level)
1064 for (q = *temp_slots_at_level (temp_slot_level); q; q = next)
1068 if (p != q && q->addr_taken)
1069 move_slot_to_level (q, temp_slot_level - 1);
1072 move_slot_to_level (p, temp_slot_level - 1);
1078 /* Otherwise, preserve all non-kept slots at this level. */
1079 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1084 move_slot_to_level (p, temp_slot_level - 1);
1088 /* Free all temporaries used so far. This is normally called at the
1089 end of generating code for a statement. */
1092 free_temp_slots (void)
1094 struct temp_slot *p, *next;
1096 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1101 make_slot_available (p);
1104 combine_temp_slots ();
1107 /* Push deeper into the nesting level for stack temporaries. */
1110 push_temp_slots (void)
1115 /* Pop a temporary nesting level. All slots in use in the current level
1119 pop_temp_slots (void)
1121 struct temp_slot *p, *next;
1123 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1126 make_slot_available (p);
1129 combine_temp_slots ();
1134 /* Initialize temporary slots. */
1137 init_temp_slots (void)
1139 /* We have not allocated any temporaries yet. */
1140 avail_temp_slots = 0;
1141 used_temp_slots = 0;
1142 temp_slot_level = 0;
1145 /* These routines are responsible for converting virtual register references
1146 to the actual hard register references once RTL generation is complete.
1148 The following four variables are used for communication between the
1149 routines. They contain the offsets of the virtual registers from their
1150 respective hard registers. */
1152 static int in_arg_offset;
1153 static int var_offset;
1154 static int dynamic_offset;
1155 static int out_arg_offset;
1156 static int cfa_offset;
1158 /* In most machines, the stack pointer register is equivalent to the bottom
1161 #ifndef STACK_POINTER_OFFSET
1162 #define STACK_POINTER_OFFSET 0
1165 /* If not defined, pick an appropriate default for the offset of dynamically
1166 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
1167 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
1169 #ifndef STACK_DYNAMIC_OFFSET
1171 /* The bottom of the stack points to the actual arguments. If
1172 REG_PARM_STACK_SPACE is defined, this includes the space for the register
1173 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
1174 stack space for register parameters is not pushed by the caller, but
1175 rather part of the fixed stack areas and hence not included in
1176 `current_function_outgoing_args_size'. Nevertheless, we must allow
1177 for it when allocating stack dynamic objects. */
1179 #if defined(REG_PARM_STACK_SPACE)
1180 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1181 ((ACCUMULATE_OUTGOING_ARGS \
1182 ? (current_function_outgoing_args_size \
1183 + (OUTGOING_REG_PARM_STACK_SPACE ? 0 : REG_PARM_STACK_SPACE (FNDECL))) \
1184 : 0) + (STACK_POINTER_OFFSET))
1186 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1187 ((ACCUMULATE_OUTGOING_ARGS ? current_function_outgoing_args_size : 0) \
1188 + (STACK_POINTER_OFFSET))
1193 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
1194 is a virtual register, return the equivalent hard register and set the
1195 offset indirectly through the pointer. Otherwise, return 0. */
1198 instantiate_new_reg (rtx x, HOST_WIDE_INT *poffset)
1201 HOST_WIDE_INT offset;
1203 if (x == virtual_incoming_args_rtx)
1204 new = arg_pointer_rtx, offset = in_arg_offset;
1205 else if (x == virtual_stack_vars_rtx)
1206 new = frame_pointer_rtx, offset = var_offset;
1207 else if (x == virtual_stack_dynamic_rtx)
1208 new = stack_pointer_rtx, offset = dynamic_offset;
1209 else if (x == virtual_outgoing_args_rtx)
1210 new = stack_pointer_rtx, offset = out_arg_offset;
1211 else if (x == virtual_cfa_rtx)
1213 #ifdef FRAME_POINTER_CFA_OFFSET
1214 new = frame_pointer_rtx;
1216 new = arg_pointer_rtx;
1218 offset = cfa_offset;
1227 /* A subroutine of instantiate_virtual_regs, called via for_each_rtx.
1228 Instantiate any virtual registers present inside of *LOC. The expression
1229 is simplified, as much as possible, but is not to be considered "valid"
1230 in any sense implied by the target. If any change is made, set CHANGED
1234 instantiate_virtual_regs_in_rtx (rtx *loc, void *data)
1236 HOST_WIDE_INT offset;
1237 bool *changed = (bool *) data;
1244 switch (GET_CODE (x))
1247 new = instantiate_new_reg (x, &offset);
1250 *loc = plus_constant (new, offset);
1257 new = instantiate_new_reg (XEXP (x, 0), &offset);
1260 new = plus_constant (new, offset);
1261 *loc = simplify_gen_binary (PLUS, GET_MODE (x), new, XEXP (x, 1));
1267 /* FIXME -- from old code */
1268 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
1269 we can commute the PLUS and SUBREG because pointers into the
1270 frame are well-behaved. */
1280 /* A subroutine of instantiate_virtual_regs_in_insn. Return true if X
1281 matches the predicate for insn CODE operand OPERAND. */
1284 safe_insn_predicate (int code, int operand, rtx x)
1286 const struct insn_operand_data *op_data;
1291 op_data = &insn_data[code].operand[operand];
1292 if (op_data->predicate == NULL)
1295 return op_data->predicate (x, op_data->mode);
1298 /* A subroutine of instantiate_virtual_regs. Instantiate any virtual
1299 registers present inside of insn. The result will be a valid insn. */
1302 instantiate_virtual_regs_in_insn (rtx insn)
1304 HOST_WIDE_INT offset;
1306 bool any_change = false;
1307 rtx set, new, x, seq;
1309 /* There are some special cases to be handled first. */
1310 set = single_set (insn);
1313 /* We're allowed to assign to a virtual register. This is interpreted
1314 to mean that the underlying register gets assigned the inverse
1315 transformation. This is used, for example, in the handling of
1317 new = instantiate_new_reg (SET_DEST (set), &offset);
1322 for_each_rtx (&SET_SRC (set), instantiate_virtual_regs_in_rtx, NULL);
1323 x = simplify_gen_binary (PLUS, GET_MODE (new), SET_SRC (set),
1325 x = force_operand (x, new);
1327 emit_move_insn (new, x);
1332 emit_insn_before (seq, insn);
1337 /* Handle a straight copy from a virtual register by generating a
1338 new add insn. The difference between this and falling through
1339 to the generic case is avoiding a new pseudo and eliminating a
1340 move insn in the initial rtl stream. */
1341 new = instantiate_new_reg (SET_SRC (set), &offset);
1342 if (new && offset != 0
1343 && REG_P (SET_DEST (set))
1344 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1348 x = expand_simple_binop (GET_MODE (SET_DEST (set)), PLUS,
1349 new, GEN_INT (offset), SET_DEST (set),
1350 1, OPTAB_LIB_WIDEN);
1351 if (x != SET_DEST (set))
1352 emit_move_insn (SET_DEST (set), x);
1357 emit_insn_before (seq, insn);
1362 extract_insn (insn);
1363 insn_code = INSN_CODE (insn);
1365 /* Handle a plus involving a virtual register by determining if the
1366 operands remain valid if they're modified in place. */
1367 if (GET_CODE (SET_SRC (set)) == PLUS
1368 && recog_data.n_operands >= 3
1369 && recog_data.operand_loc[1] == &XEXP (SET_SRC (set), 0)
1370 && recog_data.operand_loc[2] == &XEXP (SET_SRC (set), 1)
1371 && GET_CODE (recog_data.operand[2]) == CONST_INT
1372 && (new = instantiate_new_reg (recog_data.operand[1], &offset)))
1374 offset += INTVAL (recog_data.operand[2]);
1376 /* If the sum is zero, then replace with a plain move. */
1378 && REG_P (SET_DEST (set))
1379 && REGNO (SET_DEST (set)) > LAST_VIRTUAL_REGISTER)
1382 emit_move_insn (SET_DEST (set), new);
1386 emit_insn_before (seq, insn);
1391 x = gen_int_mode (offset, recog_data.operand_mode[2]);
1393 /* Using validate_change and apply_change_group here leaves
1394 recog_data in an invalid state. Since we know exactly what
1395 we want to check, do those two by hand. */
1396 if (safe_insn_predicate (insn_code, 1, new)
1397 && safe_insn_predicate (insn_code, 2, x))
1399 *recog_data.operand_loc[1] = recog_data.operand[1] = new;
1400 *recog_data.operand_loc[2] = recog_data.operand[2] = x;
1403 /* Fall through into the regular operand fixup loop in
1404 order to take care of operands other than 1 and 2. */
1410 extract_insn (insn);
1411 insn_code = INSN_CODE (insn);
1414 /* In the general case, we expect virtual registers to appear only in
1415 operands, and then only as either bare registers or inside memories. */
1416 for (i = 0; i < recog_data.n_operands; ++i)
1418 x = recog_data.operand[i];
1419 switch (GET_CODE (x))
1423 rtx addr = XEXP (x, 0);
1424 bool changed = false;
1426 for_each_rtx (&addr, instantiate_virtual_regs_in_rtx, &changed);
1431 x = replace_equiv_address (x, addr);
1432 /* It may happen that the address with the virtual reg
1433 was valid (e.g. based on the virtual stack reg, which might
1434 be acceptable to the predicates with all offsets), whereas
1435 the address now isn't anymore, for instance when the address
1436 is still offsetted, but the base reg isn't virtual-stack-reg
1437 anymore. Below we would do a force_reg on the whole operand,
1438 but this insn might actually only accept memory. Hence,
1439 before doing that last resort, try to reload the address into
1440 a register, so this operand stays a MEM. */
1441 if (!safe_insn_predicate (insn_code, i, x))
1443 addr = force_reg (GET_MODE (addr), addr);
1444 x = replace_equiv_address (x, addr);
1449 emit_insn_before (seq, insn);
1454 new = instantiate_new_reg (x, &offset);
1463 /* Careful, special mode predicates may have stuff in
1464 insn_data[insn_code].operand[i].mode that isn't useful
1465 to us for computing a new value. */
1466 /* ??? Recognize address_operand and/or "p" constraints
1467 to see if (plus new offset) is a valid before we put
1468 this through expand_simple_binop. */
1469 x = expand_simple_binop (GET_MODE (x), PLUS, new,
1470 GEN_INT (offset), NULL_RTX,
1471 1, OPTAB_LIB_WIDEN);
1474 emit_insn_before (seq, insn);
1479 new = instantiate_new_reg (SUBREG_REG (x), &offset);
1485 new = expand_simple_binop (GET_MODE (new), PLUS, new,
1486 GEN_INT (offset), NULL_RTX,
1487 1, OPTAB_LIB_WIDEN);
1490 emit_insn_before (seq, insn);
1492 x = simplify_gen_subreg (recog_data.operand_mode[i], new,
1493 GET_MODE (new), SUBREG_BYTE (x));
1500 /* At this point, X contains the new value for the operand.
1501 Validate the new value vs the insn predicate. Note that
1502 asm insns will have insn_code -1 here. */
1503 if (!safe_insn_predicate (insn_code, i, x))
1506 x = force_reg (insn_data[insn_code].operand[i].mode, x);
1510 emit_insn_before (seq, insn);
1513 *recog_data.operand_loc[i] = recog_data.operand[i] = x;
1519 /* Propagate operand changes into the duplicates. */
1520 for (i = 0; i < recog_data.n_dups; ++i)
1521 *recog_data.dup_loc[i]
1522 = copy_rtx (recog_data.operand[(unsigned)recog_data.dup_num[i]]);
1524 /* Force re-recognition of the instruction for validation. */
1525 INSN_CODE (insn) = -1;
1528 if (asm_noperands (PATTERN (insn)) >= 0)
1530 if (!check_asm_operands (PATTERN (insn)))
1532 error_for_asm (insn, "impossible constraint in %<asm%>");
1538 if (recog_memoized (insn) < 0)
1539 fatal_insn_not_found (insn);
1543 /* Subroutine of instantiate_decls. Given RTL representing a decl,
1544 do any instantiation required. */
1547 instantiate_decl_rtl (rtx x)
1554 /* If this is a CONCAT, recurse for the pieces. */
1555 if (GET_CODE (x) == CONCAT)
1557 instantiate_decl_rtl (XEXP (x, 0));
1558 instantiate_decl_rtl (XEXP (x, 1));
1562 /* If this is not a MEM, no need to do anything. Similarly if the
1563 address is a constant or a register that is not a virtual register. */
1568 if (CONSTANT_P (addr)
1570 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
1571 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
1574 for_each_rtx (&XEXP (x, 0), instantiate_virtual_regs_in_rtx, NULL);
1577 /* Helper for instantiate_decls called via walk_tree: Process all decls
1578 in the given DECL_VALUE_EXPR. */
1581 instantiate_expr (tree *tp, int *walk_subtrees, void *data ATTRIBUTE_UNUSED)
1584 if (! EXPR_P (t) && ! GIMPLE_STMT_P (t))
1587 if (DECL_P (t) && DECL_RTL_SET_P (t))
1588 instantiate_decl_rtl (DECL_RTL (t));
1593 /* Subroutine of instantiate_decls: Process all decls in the given
1594 BLOCK node and all its subblocks. */
1597 instantiate_decls_1 (tree let)
1601 for (t = BLOCK_VARS (let); t; t = TREE_CHAIN (t))
1603 if (DECL_RTL_SET_P (t))
1604 instantiate_decl_rtl (DECL_RTL (t));
1605 if (TREE_CODE (t) == VAR_DECL && DECL_HAS_VALUE_EXPR_P (t))
1607 tree v = DECL_VALUE_EXPR (t);
1608 walk_tree (&v, instantiate_expr, NULL, NULL);
1612 /* Process all subblocks. */
1613 for (t = BLOCK_SUBBLOCKS (let); t; t = BLOCK_CHAIN (t))
1614 instantiate_decls_1 (t);
1617 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1618 all virtual registers in their DECL_RTL's. */
1621 instantiate_decls (tree fndecl)
1625 /* Process all parameters of the function. */
1626 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = TREE_CHAIN (decl))
1628 instantiate_decl_rtl (DECL_RTL (decl));
1629 instantiate_decl_rtl (DECL_INCOMING_RTL (decl));
1630 if (DECL_HAS_VALUE_EXPR_P (decl))
1632 tree v = DECL_VALUE_EXPR (decl);
1633 walk_tree (&v, instantiate_expr, NULL, NULL);
1637 /* Now process all variables defined in the function or its subblocks. */
1638 instantiate_decls_1 (DECL_INITIAL (fndecl));
1641 /* Pass through the INSNS of function FNDECL and convert virtual register
1642 references to hard register references. */
1645 instantiate_virtual_regs (void)
1649 /* Compute the offsets to use for this function. */
1650 in_arg_offset = FIRST_PARM_OFFSET (current_function_decl);
1651 var_offset = STARTING_FRAME_OFFSET;
1652 dynamic_offset = STACK_DYNAMIC_OFFSET (current_function_decl);
1653 out_arg_offset = STACK_POINTER_OFFSET;
1654 #ifdef FRAME_POINTER_CFA_OFFSET
1655 cfa_offset = FRAME_POINTER_CFA_OFFSET (current_function_decl);
1657 cfa_offset = ARG_POINTER_CFA_OFFSET (current_function_decl);
1660 /* Initialize recognition, indicating that volatile is OK. */
1663 /* Scan through all the insns, instantiating every virtual register still
1665 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
1668 /* These patterns in the instruction stream can never be recognized.
1669 Fortunately, they shouldn't contain virtual registers either. */
1670 if (GET_CODE (PATTERN (insn)) == USE
1671 || GET_CODE (PATTERN (insn)) == CLOBBER
1672 || GET_CODE (PATTERN (insn)) == ADDR_VEC
1673 || GET_CODE (PATTERN (insn)) == ADDR_DIFF_VEC
1674 || GET_CODE (PATTERN (insn)) == ASM_INPUT)
1677 instantiate_virtual_regs_in_insn (insn);
1679 if (INSN_DELETED_P (insn))
1682 for_each_rtx (®_NOTES (insn), instantiate_virtual_regs_in_rtx, NULL);
1684 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
1685 if (GET_CODE (insn) == CALL_INSN)
1686 for_each_rtx (&CALL_INSN_FUNCTION_USAGE (insn),
1687 instantiate_virtual_regs_in_rtx, NULL);
1690 /* Instantiate the virtual registers in the DECLs for debugging purposes. */
1691 instantiate_decls (current_function_decl);
1693 targetm.instantiate_decls ();
1695 /* Indicate that, from now on, assign_stack_local should use
1696 frame_pointer_rtx. */
1697 virtuals_instantiated = 1;
1701 struct rtl_opt_pass pass_instantiate_virtual_regs =
1707 instantiate_virtual_regs, /* execute */
1710 0, /* static_pass_number */
1712 0, /* properties_required */
1713 0, /* properties_provided */
1714 0, /* properties_destroyed */
1715 0, /* todo_flags_start */
1716 TODO_dump_func /* todo_flags_finish */
1721 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
1722 This means a type for which function calls must pass an address to the
1723 function or get an address back from the function.
1724 EXP may be a type node or an expression (whose type is tested). */
1727 aggregate_value_p (const_tree exp, const_tree fntype)
1729 int i, regno, nregs;
1732 const_tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
1734 /* DECL node associated with FNTYPE when relevant, which we might need to
1735 check for by-invisible-reference returns, typically for CALL_EXPR input
1737 const_tree fndecl = NULL_TREE;
1740 switch (TREE_CODE (fntype))
1743 fndecl = get_callee_fndecl (fntype);
1744 fntype = fndecl ? TREE_TYPE (fndecl) : 0;
1748 fntype = TREE_TYPE (fndecl);
1753 case IDENTIFIER_NODE:
1757 /* We don't expect other rtl types here. */
1761 if (TREE_CODE (type) == VOID_TYPE)
1764 /* If the front end has decided that this needs to be passed by
1765 reference, do so. */
1766 if ((TREE_CODE (exp) == PARM_DECL || TREE_CODE (exp) == RESULT_DECL)
1767 && DECL_BY_REFERENCE (exp))
1770 /* If the EXPression is a CALL_EXPR, honor DECL_BY_REFERENCE set on the
1771 called function RESULT_DECL, meaning the function returns in memory by
1772 invisible reference. This check lets front-ends not set TREE_ADDRESSABLE
1773 on the function type, which used to be the way to request such a return
1774 mechanism but might now be causing troubles at gimplification time if
1775 temporaries with the function type need to be created. */
1776 if (TREE_CODE (exp) == CALL_EXPR && fndecl && DECL_RESULT (fndecl)
1777 && DECL_BY_REFERENCE (DECL_RESULT (fndecl)))
1780 if (targetm.calls.return_in_memory (type, fntype))
1782 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
1783 and thus can't be returned in registers. */
1784 if (TREE_ADDRESSABLE (type))
1786 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
1788 /* Make sure we have suitable call-clobbered regs to return
1789 the value in; if not, we must return it in memory. */
1790 reg = hard_function_value (type, 0, fntype, 0);
1792 /* If we have something other than a REG (e.g. a PARALLEL), then assume
1797 regno = REGNO (reg);
1798 nregs = hard_regno_nregs[regno][TYPE_MODE (type)];
1799 for (i = 0; i < nregs; i++)
1800 if (! call_used_regs[regno + i])
1805 /* Return true if we should assign DECL a pseudo register; false if it
1806 should live on the local stack. */
1809 use_register_for_decl (const_tree decl)
1811 /* Honor volatile. */
1812 if (TREE_SIDE_EFFECTS (decl))
1815 /* Honor addressability. */
1816 if (TREE_ADDRESSABLE (decl))
1819 /* Only register-like things go in registers. */
1820 if (DECL_MODE (decl) == BLKmode)
1823 /* If -ffloat-store specified, don't put explicit float variables
1825 /* ??? This should be checked after DECL_ARTIFICIAL, but tree-ssa
1826 propagates values across these stores, and it probably shouldn't. */
1827 if (flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)))
1830 /* If we're not interested in tracking debugging information for
1831 this decl, then we can certainly put it in a register. */
1832 if (DECL_IGNORED_P (decl))
1835 return (optimize || DECL_REGISTER (decl));
1838 /* Return true if TYPE should be passed by invisible reference. */
1841 pass_by_reference (CUMULATIVE_ARGS *ca, enum machine_mode mode,
1842 tree type, bool named_arg)
1846 /* If this type contains non-trivial constructors, then it is
1847 forbidden for the middle-end to create any new copies. */
1848 if (TREE_ADDRESSABLE (type))
1851 /* GCC post 3.4 passes *all* variable sized types by reference. */
1852 if (!TYPE_SIZE (type) || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
1856 return targetm.calls.pass_by_reference (ca, mode, type, named_arg);
1859 /* Return true if TYPE, which is passed by reference, should be callee
1860 copied instead of caller copied. */
1863 reference_callee_copied (CUMULATIVE_ARGS *ca, enum machine_mode mode,
1864 tree type, bool named_arg)
1866 if (type && TREE_ADDRESSABLE (type))
1868 return targetm.calls.callee_copies (ca, mode, type, named_arg);
1871 /* Structures to communicate between the subroutines of assign_parms.
1872 The first holds data persistent across all parameters, the second
1873 is cleared out for each parameter. */
1875 struct assign_parm_data_all
1877 CUMULATIVE_ARGS args_so_far;
1878 struct args_size stack_args_size;
1879 tree function_result_decl;
1881 rtx first_conversion_insn;
1882 rtx last_conversion_insn;
1883 HOST_WIDE_INT pretend_args_size;
1884 HOST_WIDE_INT extra_pretend_bytes;
1885 int reg_parm_stack_space;
1888 struct assign_parm_data_one
1894 enum machine_mode nominal_mode;
1895 enum machine_mode passed_mode;
1896 enum machine_mode promoted_mode;
1897 struct locate_and_pad_arg_data locate;
1899 BOOL_BITFIELD named_arg : 1;
1900 BOOL_BITFIELD passed_pointer : 1;
1901 BOOL_BITFIELD on_stack : 1;
1902 BOOL_BITFIELD loaded_in_reg : 1;
1905 /* A subroutine of assign_parms. Initialize ALL. */
1908 assign_parms_initialize_all (struct assign_parm_data_all *all)
1912 memset (all, 0, sizeof (*all));
1914 fntype = TREE_TYPE (current_function_decl);
1916 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
1917 INIT_CUMULATIVE_INCOMING_ARGS (all->args_so_far, fntype, NULL_RTX);
1919 INIT_CUMULATIVE_ARGS (all->args_so_far, fntype, NULL_RTX,
1920 current_function_decl, -1);
1923 #ifdef REG_PARM_STACK_SPACE
1924 all->reg_parm_stack_space = REG_PARM_STACK_SPACE (current_function_decl);
1928 /* If ARGS contains entries with complex types, split the entry into two
1929 entries of the component type. Return a new list of substitutions are
1930 needed, else the old list. */
1933 split_complex_args (tree args)
1937 /* Before allocating memory, check for the common case of no complex. */
1938 for (p = args; p; p = TREE_CHAIN (p))
1940 tree type = TREE_TYPE (p);
1941 if (TREE_CODE (type) == COMPLEX_TYPE
1942 && targetm.calls.split_complex_arg (type))
1948 args = copy_list (args);
1950 for (p = args; p; p = TREE_CHAIN (p))
1952 tree type = TREE_TYPE (p);
1953 if (TREE_CODE (type) == COMPLEX_TYPE
1954 && targetm.calls.split_complex_arg (type))
1957 tree subtype = TREE_TYPE (type);
1958 bool addressable = TREE_ADDRESSABLE (p);
1960 /* Rewrite the PARM_DECL's type with its component. */
1961 TREE_TYPE (p) = subtype;
1962 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
1963 DECL_MODE (p) = VOIDmode;
1964 DECL_SIZE (p) = NULL;
1965 DECL_SIZE_UNIT (p) = NULL;
1966 /* If this arg must go in memory, put it in a pseudo here.
1967 We can't allow it to go in memory as per normal parms,
1968 because the usual place might not have the imag part
1969 adjacent to the real part. */
1970 DECL_ARTIFICIAL (p) = addressable;
1971 DECL_IGNORED_P (p) = addressable;
1972 TREE_ADDRESSABLE (p) = 0;
1975 /* Build a second synthetic decl. */
1976 decl = build_decl (PARM_DECL, NULL_TREE, subtype);
1977 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
1978 DECL_ARTIFICIAL (decl) = addressable;
1979 DECL_IGNORED_P (decl) = addressable;
1980 layout_decl (decl, 0);
1982 /* Splice it in; skip the new decl. */
1983 TREE_CHAIN (decl) = TREE_CHAIN (p);
1984 TREE_CHAIN (p) = decl;
1992 /* A subroutine of assign_parms. Adjust the parameter list to incorporate
1993 the hidden struct return argument, and (abi willing) complex args.
1994 Return the new parameter list. */
1997 assign_parms_augmented_arg_list (struct assign_parm_data_all *all)
1999 tree fndecl = current_function_decl;
2000 tree fntype = TREE_TYPE (fndecl);
2001 tree fnargs = DECL_ARGUMENTS (fndecl);
2003 /* If struct value address is treated as the first argument, make it so. */
2004 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
2005 && ! current_function_returns_pcc_struct
2006 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
2008 tree type = build_pointer_type (TREE_TYPE (fntype));
2011 decl = build_decl (PARM_DECL, NULL_TREE, type);
2012 DECL_ARG_TYPE (decl) = type;
2013 DECL_ARTIFICIAL (decl) = 1;
2014 DECL_IGNORED_P (decl) = 1;
2016 TREE_CHAIN (decl) = fnargs;
2018 all->function_result_decl = decl;
2021 all->orig_fnargs = fnargs;
2023 /* If the target wants to split complex arguments into scalars, do so. */
2024 if (targetm.calls.split_complex_arg)
2025 fnargs = split_complex_args (fnargs);
2030 /* A subroutine of assign_parms. Examine PARM and pull out type and mode
2031 data for the parameter. Incorporate ABI specifics such as pass-by-
2032 reference and type promotion. */
2035 assign_parm_find_data_types (struct assign_parm_data_all *all, tree parm,
2036 struct assign_parm_data_one *data)
2038 tree nominal_type, passed_type;
2039 enum machine_mode nominal_mode, passed_mode, promoted_mode;
2041 memset (data, 0, sizeof (*data));
2043 /* NAMED_ARG is a mis-nomer. We really mean 'non-varadic'. */
2044 if (!current_function_stdarg)
2045 data->named_arg = 1; /* No varadic parms. */
2046 else if (TREE_CHAIN (parm))
2047 data->named_arg = 1; /* Not the last non-varadic parm. */
2048 else if (targetm.calls.strict_argument_naming (&all->args_so_far))
2049 data->named_arg = 1; /* Only varadic ones are unnamed. */
2051 data->named_arg = 0; /* Treat as varadic. */
2053 nominal_type = TREE_TYPE (parm);
2054 passed_type = DECL_ARG_TYPE (parm);
2056 /* Look out for errors propagating this far. Also, if the parameter's
2057 type is void then its value doesn't matter. */
2058 if (TREE_TYPE (parm) == error_mark_node
2059 /* This can happen after weird syntax errors
2060 or if an enum type is defined among the parms. */
2061 || TREE_CODE (parm) != PARM_DECL
2062 || passed_type == NULL
2063 || VOID_TYPE_P (nominal_type))
2065 nominal_type = passed_type = void_type_node;
2066 nominal_mode = passed_mode = promoted_mode = VOIDmode;
2070 /* Find mode of arg as it is passed, and mode of arg as it should be
2071 during execution of this function. */
2072 passed_mode = TYPE_MODE (passed_type);
2073 nominal_mode = TYPE_MODE (nominal_type);
2075 /* If the parm is to be passed as a transparent union, use the type of
2076 the first field for the tests below. We have already verified that
2077 the modes are the same. */
2078 if (TREE_CODE (passed_type) == UNION_TYPE
2079 && TYPE_TRANSPARENT_UNION (passed_type))
2080 passed_type = TREE_TYPE (TYPE_FIELDS (passed_type));
2082 /* See if this arg was passed by invisible reference. */
2083 if (pass_by_reference (&all->args_so_far, passed_mode,
2084 passed_type, data->named_arg))
2086 passed_type = nominal_type = build_pointer_type (passed_type);
2087 data->passed_pointer = true;
2088 passed_mode = nominal_mode = Pmode;
2091 /* Find mode as it is passed by the ABI. */
2092 promoted_mode = passed_mode;
2093 if (targetm.calls.promote_function_args (TREE_TYPE (current_function_decl)))
2095 int unsignedp = TYPE_UNSIGNED (passed_type);
2096 promoted_mode = promote_mode (passed_type, promoted_mode,
2101 data->nominal_type = nominal_type;
2102 data->passed_type = passed_type;
2103 data->nominal_mode = nominal_mode;
2104 data->passed_mode = passed_mode;
2105 data->promoted_mode = promoted_mode;
2108 /* A subroutine of assign_parms. Invoke setup_incoming_varargs. */
2111 assign_parms_setup_varargs (struct assign_parm_data_all *all,
2112 struct assign_parm_data_one *data, bool no_rtl)
2114 int varargs_pretend_bytes = 0;
2116 targetm.calls.setup_incoming_varargs (&all->args_so_far,
2117 data->promoted_mode,
2119 &varargs_pretend_bytes, no_rtl);
2121 /* If the back-end has requested extra stack space, record how much is
2122 needed. Do not change pretend_args_size otherwise since it may be
2123 nonzero from an earlier partial argument. */
2124 if (varargs_pretend_bytes > 0)
2125 all->pretend_args_size = varargs_pretend_bytes;
2128 /* A subroutine of assign_parms. Set DATA->ENTRY_PARM corresponding to
2129 the incoming location of the current parameter. */
2132 assign_parm_find_entry_rtl (struct assign_parm_data_all *all,
2133 struct assign_parm_data_one *data)
2135 HOST_WIDE_INT pretend_bytes = 0;
2139 if (data->promoted_mode == VOIDmode)
2141 data->entry_parm = data->stack_parm = const0_rtx;
2145 #ifdef FUNCTION_INCOMING_ARG
2146 entry_parm = FUNCTION_INCOMING_ARG (all->args_so_far, data->promoted_mode,
2147 data->passed_type, data->named_arg);
2149 entry_parm = FUNCTION_ARG (all->args_so_far, data->promoted_mode,
2150 data->passed_type, data->named_arg);
2153 if (entry_parm == 0)
2154 data->promoted_mode = data->passed_mode;
2156 /* Determine parm's home in the stack, in case it arrives in the stack
2157 or we should pretend it did. Compute the stack position and rtx where
2158 the argument arrives and its size.
2160 There is one complexity here: If this was a parameter that would
2161 have been passed in registers, but wasn't only because it is
2162 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2163 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2164 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of 0
2165 as it was the previous time. */
2166 in_regs = entry_parm != 0;
2167 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2170 if (!in_regs && !data->named_arg)
2172 if (targetm.calls.pretend_outgoing_varargs_named (&all->args_so_far))
2175 #ifdef FUNCTION_INCOMING_ARG
2176 tem = FUNCTION_INCOMING_ARG (all->args_so_far, data->promoted_mode,
2177 data->passed_type, true);
2179 tem = FUNCTION_ARG (all->args_so_far, data->promoted_mode,
2180 data->passed_type, true);
2182 in_regs = tem != NULL;
2186 /* If this parameter was passed both in registers and in the stack, use
2187 the copy on the stack. */
2188 if (targetm.calls.must_pass_in_stack (data->promoted_mode,
2196 partial = targetm.calls.arg_partial_bytes (&all->args_so_far,
2197 data->promoted_mode,
2200 data->partial = partial;
2202 /* The caller might already have allocated stack space for the
2203 register parameters. */
2204 if (partial != 0 && all->reg_parm_stack_space == 0)
2206 /* Part of this argument is passed in registers and part
2207 is passed on the stack. Ask the prologue code to extend
2208 the stack part so that we can recreate the full value.
2210 PRETEND_BYTES is the size of the registers we need to store.
2211 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
2212 stack space that the prologue should allocate.
2214 Internally, gcc assumes that the argument pointer is aligned
2215 to STACK_BOUNDARY bits. This is used both for alignment
2216 optimizations (see init_emit) and to locate arguments that are
2217 aligned to more than PARM_BOUNDARY bits. We must preserve this
2218 invariant by rounding CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to
2219 a stack boundary. */
2221 /* We assume at most one partial arg, and it must be the first
2222 argument on the stack. */
2223 gcc_assert (!all->extra_pretend_bytes && !all->pretend_args_size);
2225 pretend_bytes = partial;
2226 all->pretend_args_size = CEIL_ROUND (pretend_bytes, STACK_BYTES);
2228 /* We want to align relative to the actual stack pointer, so
2229 don't include this in the stack size until later. */
2230 all->extra_pretend_bytes = all->pretend_args_size;
2234 locate_and_pad_parm (data->promoted_mode, data->passed_type, in_regs,
2235 entry_parm ? data->partial : 0, current_function_decl,
2236 &all->stack_args_size, &data->locate);
2238 /* Adjust offsets to include the pretend args. */
2239 pretend_bytes = all->extra_pretend_bytes - pretend_bytes;
2240 data->locate.slot_offset.constant += pretend_bytes;
2241 data->locate.offset.constant += pretend_bytes;
2243 data->entry_parm = entry_parm;
2246 /* A subroutine of assign_parms. If there is actually space on the stack
2247 for this parm, count it in stack_args_size and return true. */
2250 assign_parm_is_stack_parm (struct assign_parm_data_all *all,
2251 struct assign_parm_data_one *data)
2253 /* Trivially true if we've no incoming register. */
2254 if (data->entry_parm == NULL)
2256 /* Also true if we're partially in registers and partially not,
2257 since we've arranged to drop the entire argument on the stack. */
2258 else if (data->partial != 0)
2260 /* Also true if the target says that it's passed in both registers
2261 and on the stack. */
2262 else if (GET_CODE (data->entry_parm) == PARALLEL
2263 && XEXP (XVECEXP (data->entry_parm, 0, 0), 0) == NULL_RTX)
2265 /* Also true if the target says that there's stack allocated for
2266 all register parameters. */
2267 else if (all->reg_parm_stack_space > 0)
2269 /* Otherwise, no, this parameter has no ABI defined stack slot. */
2273 all->stack_args_size.constant += data->locate.size.constant;
2274 if (data->locate.size.var)
2275 ADD_PARM_SIZE (all->stack_args_size, data->locate.size.var);
2280 /* A subroutine of assign_parms. Given that this parameter is allocated
2281 stack space by the ABI, find it. */
2284 assign_parm_find_stack_rtl (tree parm, struct assign_parm_data_one *data)
2286 rtx offset_rtx, stack_parm;
2287 unsigned int align, boundary;
2289 /* If we're passing this arg using a reg, make its stack home the
2290 aligned stack slot. */
2291 if (data->entry_parm)
2292 offset_rtx = ARGS_SIZE_RTX (data->locate.slot_offset);
2294 offset_rtx = ARGS_SIZE_RTX (data->locate.offset);
2296 stack_parm = current_function_internal_arg_pointer;
2297 if (offset_rtx != const0_rtx)
2298 stack_parm = gen_rtx_PLUS (Pmode, stack_parm, offset_rtx);
2299 stack_parm = gen_rtx_MEM (data->promoted_mode, stack_parm);
2301 set_mem_attributes (stack_parm, parm, 1);
2303 boundary = data->locate.boundary;
2304 align = BITS_PER_UNIT;
2306 /* If we're padding upward, we know that the alignment of the slot
2307 is FUNCTION_ARG_BOUNDARY. If we're using slot_offset, we're
2308 intentionally forcing upward padding. Otherwise we have to come
2309 up with a guess at the alignment based on OFFSET_RTX. */
2310 if (data->locate.where_pad != downward || data->entry_parm)
2312 else if (GET_CODE (offset_rtx) == CONST_INT)
2314 align = INTVAL (offset_rtx) * BITS_PER_UNIT | boundary;
2315 align = align & -align;
2317 set_mem_align (stack_parm, align);
2319 if (data->entry_parm)
2320 set_reg_attrs_for_parm (data->entry_parm, stack_parm);
2322 data->stack_parm = stack_parm;
2325 /* A subroutine of assign_parms. Adjust DATA->ENTRY_RTL such that it's
2326 always valid and contiguous. */
2329 assign_parm_adjust_entry_rtl (struct assign_parm_data_one *data)
2331 rtx entry_parm = data->entry_parm;
2332 rtx stack_parm = data->stack_parm;
2334 /* If this parm was passed part in regs and part in memory, pretend it
2335 arrived entirely in memory by pushing the register-part onto the stack.
2336 In the special case of a DImode or DFmode that is split, we could put
2337 it together in a pseudoreg directly, but for now that's not worth
2339 if (data->partial != 0)
2341 /* Handle calls that pass values in multiple non-contiguous
2342 locations. The Irix 6 ABI has examples of this. */
2343 if (GET_CODE (entry_parm) == PARALLEL)
2344 emit_group_store (validize_mem (stack_parm), entry_parm,
2346 int_size_in_bytes (data->passed_type));
2349 gcc_assert (data->partial % UNITS_PER_WORD == 0);
2350 move_block_from_reg (REGNO (entry_parm), validize_mem (stack_parm),
2351 data->partial / UNITS_PER_WORD);
2354 entry_parm = stack_parm;
2357 /* If we didn't decide this parm came in a register, by default it came
2359 else if (entry_parm == NULL)
2360 entry_parm = stack_parm;
2362 /* When an argument is passed in multiple locations, we can't make use
2363 of this information, but we can save some copying if the whole argument
2364 is passed in a single register. */
2365 else if (GET_CODE (entry_parm) == PARALLEL
2366 && data->nominal_mode != BLKmode
2367 && data->passed_mode != BLKmode)
2369 size_t i, len = XVECLEN (entry_parm, 0);
2371 for (i = 0; i < len; i++)
2372 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
2373 && REG_P (XEXP (XVECEXP (entry_parm, 0, i), 0))
2374 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
2375 == data->passed_mode)
2376 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
2378 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
2383 data->entry_parm = entry_parm;
2386 /* A subroutine of assign_parms. Adjust DATA->STACK_RTL such that it's
2387 always valid and properly aligned. */
2390 assign_parm_adjust_stack_rtl (struct assign_parm_data_one *data)
2392 rtx stack_parm = data->stack_parm;
2394 /* If we can't trust the parm stack slot to be aligned enough for its
2395 ultimate type, don't use that slot after entry. We'll make another
2396 stack slot, if we need one. */
2398 && ((STRICT_ALIGNMENT
2399 && GET_MODE_ALIGNMENT (data->nominal_mode) > MEM_ALIGN (stack_parm))
2400 || (data->nominal_type
2401 && TYPE_ALIGN (data->nominal_type) > MEM_ALIGN (stack_parm)
2402 && MEM_ALIGN (stack_parm) < PREFERRED_STACK_BOUNDARY)))
2405 /* If parm was passed in memory, and we need to convert it on entry,
2406 don't store it back in that same slot. */
2407 else if (data->entry_parm == stack_parm
2408 && data->nominal_mode != BLKmode
2409 && data->nominal_mode != data->passed_mode)
2412 /* If stack protection is in effect for this function, don't leave any
2413 pointers in their passed stack slots. */
2414 else if (cfun->stack_protect_guard
2415 && (flag_stack_protect == 2
2416 || data->passed_pointer
2417 || POINTER_TYPE_P (data->nominal_type)))
2420 data->stack_parm = stack_parm;
2423 /* A subroutine of assign_parms. Return true if the current parameter
2424 should be stored as a BLKmode in the current frame. */
2427 assign_parm_setup_block_p (struct assign_parm_data_one *data)
2429 if (data->nominal_mode == BLKmode)
2431 if (GET_CODE (data->entry_parm) == PARALLEL)
2434 #ifdef BLOCK_REG_PADDING
2435 /* Only assign_parm_setup_block knows how to deal with register arguments
2436 that are padded at the least significant end. */
2437 if (REG_P (data->entry_parm)
2438 && GET_MODE_SIZE (data->promoted_mode) < UNITS_PER_WORD
2439 && (BLOCK_REG_PADDING (data->passed_mode, data->passed_type, 1)
2440 == (BYTES_BIG_ENDIAN ? upward : downward)))
2447 /* A subroutine of assign_parms. Arrange for the parameter to be
2448 present and valid in DATA->STACK_RTL. */
2451 assign_parm_setup_block (struct assign_parm_data_all *all,
2452 tree parm, struct assign_parm_data_one *data)
2454 rtx entry_parm = data->entry_parm;
2455 rtx stack_parm = data->stack_parm;
2457 HOST_WIDE_INT size_stored;
2458 rtx orig_entry_parm = entry_parm;
2460 if (GET_CODE (entry_parm) == PARALLEL)
2461 entry_parm = emit_group_move_into_temps (entry_parm);
2463 /* If we've a non-block object that's nevertheless passed in parts,
2464 reconstitute it in register operations rather than on the stack. */
2465 if (GET_CODE (entry_parm) == PARALLEL
2466 && data->nominal_mode != BLKmode)
2468 rtx elt0 = XEXP (XVECEXP (orig_entry_parm, 0, 0), 0);
2470 if ((XVECLEN (entry_parm, 0) > 1
2471 || hard_regno_nregs[REGNO (elt0)][GET_MODE (elt0)] > 1)
2472 && use_register_for_decl (parm))
2474 rtx parmreg = gen_reg_rtx (data->nominal_mode);
2476 push_to_sequence2 (all->first_conversion_insn,
2477 all->last_conversion_insn);
2479 /* For values returned in multiple registers, handle possible
2480 incompatible calls to emit_group_store.
2482 For example, the following would be invalid, and would have to
2483 be fixed by the conditional below:
2485 emit_group_store ((reg:SF), (parallel:DF))
2486 emit_group_store ((reg:SI), (parallel:DI))
2488 An example of this are doubles in e500 v2:
2489 (parallel:DF (expr_list (reg:SI) (const_int 0))
2490 (expr_list (reg:SI) (const_int 4))). */
2491 if (data->nominal_mode != data->passed_mode)
2493 rtx t = gen_reg_rtx (GET_MODE (entry_parm));
2494 emit_group_store (t, entry_parm, NULL_TREE,
2495 GET_MODE_SIZE (GET_MODE (entry_parm)));
2496 convert_move (parmreg, t, 0);
2499 emit_group_store (parmreg, entry_parm, data->nominal_type,
2500 int_size_in_bytes (data->nominal_type));
2502 all->first_conversion_insn = get_insns ();
2503 all->last_conversion_insn = get_last_insn ();
2506 SET_DECL_RTL (parm, parmreg);
2511 size = int_size_in_bytes (data->passed_type);
2512 size_stored = CEIL_ROUND (size, UNITS_PER_WORD);
2513 if (stack_parm == 0)
2515 DECL_ALIGN (parm) = MAX (DECL_ALIGN (parm), BITS_PER_WORD);
2516 stack_parm = assign_stack_local (BLKmode, size_stored,
2518 if (GET_MODE_SIZE (GET_MODE (entry_parm)) == size)
2519 PUT_MODE (stack_parm, GET_MODE (entry_parm));
2520 set_mem_attributes (stack_parm, parm, 1);
2523 /* If a BLKmode arrives in registers, copy it to a stack slot. Handle
2524 calls that pass values in multiple non-contiguous locations. */
2525 if (REG_P (entry_parm) || GET_CODE (entry_parm) == PARALLEL)
2529 /* Note that we will be storing an integral number of words.
2530 So we have to be careful to ensure that we allocate an
2531 integral number of words. We do this above when we call
2532 assign_stack_local if space was not allocated in the argument
2533 list. If it was, this will not work if PARM_BOUNDARY is not
2534 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2535 if it becomes a problem. Exception is when BLKmode arrives
2536 with arguments not conforming to word_mode. */
2538 if (data->stack_parm == 0)
2540 else if (GET_CODE (entry_parm) == PARALLEL)
2543 gcc_assert (!size || !(PARM_BOUNDARY % BITS_PER_WORD));
2545 mem = validize_mem (stack_parm);
2547 /* Handle values in multiple non-contiguous locations. */
2548 if (GET_CODE (entry_parm) == PARALLEL)
2550 push_to_sequence2 (all->first_conversion_insn,
2551 all->last_conversion_insn);
2552 emit_group_store (mem, entry_parm, data->passed_type, size);
2553 all->first_conversion_insn = get_insns ();
2554 all->last_conversion_insn = get_last_insn ();
2561 /* If SIZE is that of a mode no bigger than a word, just use
2562 that mode's store operation. */
2563 else if (size <= UNITS_PER_WORD)
2565 enum machine_mode mode
2566 = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
2569 #ifdef BLOCK_REG_PADDING
2570 && (size == UNITS_PER_WORD
2571 || (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2572 != (BYTES_BIG_ENDIAN ? upward : downward)))
2578 /* We are really truncating a word_mode value containing
2579 SIZE bytes into a value of mode MODE. If such an
2580 operation requires no actual instructions, we can refer
2581 to the value directly in mode MODE, otherwise we must
2582 start with the register in word_mode and explicitly
2584 if (TRULY_NOOP_TRUNCATION (size * BITS_PER_UNIT, BITS_PER_WORD))
2585 reg = gen_rtx_REG (mode, REGNO (entry_parm));
2588 reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
2589 reg = convert_to_mode (mode, copy_to_reg (reg), 1);
2591 emit_move_insn (change_address (mem, mode, 0), reg);
2594 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
2595 machine must be aligned to the left before storing
2596 to memory. Note that the previous test doesn't
2597 handle all cases (e.g. SIZE == 3). */
2598 else if (size != UNITS_PER_WORD
2599 #ifdef BLOCK_REG_PADDING
2600 && (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2608 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
2609 rtx reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
2611 x = expand_shift (LSHIFT_EXPR, word_mode, reg,
2612 build_int_cst (NULL_TREE, by),
2614 tem = change_address (mem, word_mode, 0);
2615 emit_move_insn (tem, x);
2618 move_block_from_reg (REGNO (entry_parm), mem,
2619 size_stored / UNITS_PER_WORD);
2622 move_block_from_reg (REGNO (entry_parm), mem,
2623 size_stored / UNITS_PER_WORD);
2625 else if (data->stack_parm == 0)
2627 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2628 emit_block_move (stack_parm, data->entry_parm, GEN_INT (size),
2630 all->first_conversion_insn = get_insns ();
2631 all->last_conversion_insn = get_last_insn ();
2635 data->stack_parm = stack_parm;
2636 SET_DECL_RTL (parm, stack_parm);
2639 /* A subroutine of assign_parms. Allocate a pseudo to hold the current
2640 parameter. Get it there. Perform all ABI specified conversions. */
2643 assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm,
2644 struct assign_parm_data_one *data)
2647 enum machine_mode promoted_nominal_mode;
2648 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (parm));
2649 bool did_conversion = false;
2651 /* Store the parm in a pseudoregister during the function, but we may
2652 need to do it in a wider mode. */
2654 /* This is not really promoting for a call. However we need to be
2655 consistent with assign_parm_find_data_types and expand_expr_real_1. */
2656 promoted_nominal_mode
2657 = promote_mode (data->nominal_type, data->nominal_mode, &unsignedp, 1);
2659 parmreg = gen_reg_rtx (promoted_nominal_mode);
2661 if (!DECL_ARTIFICIAL (parm))
2662 mark_user_reg (parmreg);
2664 /* If this was an item that we received a pointer to,
2665 set DECL_RTL appropriately. */
2666 if (data->passed_pointer)
2668 rtx x = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data->passed_type)), parmreg);
2669 set_mem_attributes (x, parm, 1);
2670 SET_DECL_RTL (parm, x);
2673 SET_DECL_RTL (parm, parmreg);
2675 /* Copy the value into the register. */
2676 if (data->nominal_mode != data->passed_mode
2677 || promoted_nominal_mode != data->promoted_mode)
2681 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
2682 mode, by the caller. We now have to convert it to
2683 NOMINAL_MODE, if different. However, PARMREG may be in
2684 a different mode than NOMINAL_MODE if it is being stored
2687 If ENTRY_PARM is a hard register, it might be in a register
2688 not valid for operating in its mode (e.g., an odd-numbered
2689 register for a DFmode). In that case, moves are the only
2690 thing valid, so we can't do a convert from there. This
2691 occurs when the calling sequence allow such misaligned
2694 In addition, the conversion may involve a call, which could
2695 clobber parameters which haven't been copied to pseudo
2696 registers yet. Therefore, we must first copy the parm to
2697 a pseudo reg here, and save the conversion until after all
2698 parameters have been moved. */
2700 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
2702 emit_move_insn (tempreg, validize_mem (data->entry_parm));
2704 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2705 tempreg = convert_to_mode (data->nominal_mode, tempreg, unsignedp);
2707 if (GET_CODE (tempreg) == SUBREG
2708 && GET_MODE (tempreg) == data->nominal_mode
2709 && REG_P (SUBREG_REG (tempreg))
2710 && data->nominal_mode == data->passed_mode
2711 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (data->entry_parm)
2712 && GET_MODE_SIZE (GET_MODE (tempreg))
2713 < GET_MODE_SIZE (GET_MODE (data->entry_parm)))
2715 /* The argument is already sign/zero extended, so note it
2717 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
2718 SUBREG_PROMOTED_UNSIGNED_SET (tempreg, unsignedp);
2721 /* TREE_USED gets set erroneously during expand_assignment. */
2722 save_tree_used = TREE_USED (parm);
2723 expand_assignment (parm, make_tree (data->nominal_type, tempreg), false);
2724 TREE_USED (parm) = save_tree_used;
2725 all->first_conversion_insn = get_insns ();
2726 all->last_conversion_insn = get_last_insn ();
2729 did_conversion = true;
2732 emit_move_insn (parmreg, validize_mem (data->entry_parm));
2734 /* If we were passed a pointer but the actual value can safely live
2735 in a register, put it in one. */
2736 if (data->passed_pointer
2737 && TYPE_MODE (TREE_TYPE (parm)) != BLKmode
2738 /* If by-reference argument was promoted, demote it. */
2739 && (TYPE_MODE (TREE_TYPE (parm)) != GET_MODE (DECL_RTL (parm))
2740 || use_register_for_decl (parm)))
2742 /* We can't use nominal_mode, because it will have been set to
2743 Pmode above. We must use the actual mode of the parm. */
2744 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
2745 mark_user_reg (parmreg);
2747 if (GET_MODE (parmreg) != GET_MODE (DECL_RTL (parm)))
2749 rtx tempreg = gen_reg_rtx (GET_MODE (DECL_RTL (parm)));
2750 int unsigned_p = TYPE_UNSIGNED (TREE_TYPE (parm));
2752 push_to_sequence2 (all->first_conversion_insn,
2753 all->last_conversion_insn);
2754 emit_move_insn (tempreg, DECL_RTL (parm));
2755 tempreg = convert_to_mode (GET_MODE (parmreg), tempreg, unsigned_p);
2756 emit_move_insn (parmreg, tempreg);
2757 all->first_conversion_insn = get_insns ();
2758 all->last_conversion_insn = get_last_insn ();
2761 did_conversion = true;
2764 emit_move_insn (parmreg, DECL_RTL (parm));
2766 SET_DECL_RTL (parm, parmreg);
2768 /* STACK_PARM is the pointer, not the parm, and PARMREG is
2770 data->stack_parm = NULL;
2773 /* Mark the register as eliminable if we did no conversion and it was
2774 copied from memory at a fixed offset, and the arg pointer was not
2775 copied to a pseudo-reg. If the arg pointer is a pseudo reg or the
2776 offset formed an invalid address, such memory-equivalences as we
2777 make here would screw up life analysis for it. */
2778 if (data->nominal_mode == data->passed_mode
2780 && data->stack_parm != 0
2781 && MEM_P (data->stack_parm)
2782 && data->locate.offset.var == 0
2783 && reg_mentioned_p (virtual_incoming_args_rtx,
2784 XEXP (data->stack_parm, 0)))
2786 rtx linsn = get_last_insn ();
2789 /* Mark complex types separately. */
2790 if (GET_CODE (parmreg) == CONCAT)
2792 enum machine_mode submode
2793 = GET_MODE_INNER (GET_MODE (parmreg));
2794 int regnor = REGNO (XEXP (parmreg, 0));
2795 int regnoi = REGNO (XEXP (parmreg, 1));
2796 rtx stackr = adjust_address_nv (data->stack_parm, submode, 0);
2797 rtx stacki = adjust_address_nv (data->stack_parm, submode,
2798 GET_MODE_SIZE (submode));
2800 /* Scan backwards for the set of the real and
2802 for (sinsn = linsn; sinsn != 0;
2803 sinsn = prev_nonnote_insn (sinsn))
2805 set = single_set (sinsn);
2809 if (SET_DEST (set) == regno_reg_rtx [regnoi])
2810 set_unique_reg_note (sinsn, REG_EQUIV, stacki);
2811 else if (SET_DEST (set) == regno_reg_rtx [regnor])
2812 set_unique_reg_note (sinsn, REG_EQUIV, stackr);
2815 else if ((set = single_set (linsn)) != 0
2816 && SET_DEST (set) == parmreg)
2817 set_unique_reg_note (linsn, REG_EQUIV, data->stack_parm);
2820 /* For pointer data type, suggest pointer register. */
2821 if (POINTER_TYPE_P (TREE_TYPE (parm)))
2822 mark_reg_pointer (parmreg,
2823 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
2826 /* A subroutine of assign_parms. Allocate stack space to hold the current
2827 parameter. Get it there. Perform all ABI specified conversions. */
2830 assign_parm_setup_stack (struct assign_parm_data_all *all, tree parm,
2831 struct assign_parm_data_one *data)
2833 /* Value must be stored in the stack slot STACK_PARM during function
2835 bool to_conversion = false;
2837 if (data->promoted_mode != data->nominal_mode)
2839 /* Conversion is required. */
2840 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
2842 emit_move_insn (tempreg, validize_mem (data->entry_parm));
2844 push_to_sequence2 (all->first_conversion_insn, all->last_conversion_insn);
2845 to_conversion = true;
2847 data->entry_parm = convert_to_mode (data->nominal_mode, tempreg,
2848 TYPE_UNSIGNED (TREE_TYPE (parm)));
2850 if (data->stack_parm)
2851 /* ??? This may need a big-endian conversion on sparc64. */
2853 = adjust_address (data->stack_parm, data->nominal_mode, 0);
2856 if (data->entry_parm != data->stack_parm)
2860 if (data->stack_parm == 0)
2863 = assign_stack_local (GET_MODE (data->entry_parm),
2864 GET_MODE_SIZE (GET_MODE (data->entry_parm)),
2865 TYPE_ALIGN (data->passed_type));
2866 set_mem_attributes (data->stack_parm, parm, 1);
2869 dest = validize_mem (data->stack_parm);
2870 src = validize_mem (data->entry_parm);
2874 /* Use a block move to handle potentially misaligned entry_parm. */
2876 push_to_sequence2 (all->first_conversion_insn,
2877 all->last_conversion_insn);
2878 to_conversion = true;
2880 emit_block_move (dest, src,
2881 GEN_INT (int_size_in_bytes (data->passed_type)),
2885 emit_move_insn (dest, src);
2890 all->first_conversion_insn = get_insns ();
2891 all->last_conversion_insn = get_last_insn ();
2895 SET_DECL_RTL (parm, data->stack_parm);
2898 /* A subroutine of assign_parms. If the ABI splits complex arguments, then
2899 undo the frobbing that we did in assign_parms_augmented_arg_list. */
2902 assign_parms_unsplit_complex (struct assign_parm_data_all *all, tree fnargs)
2905 tree orig_fnargs = all->orig_fnargs;
2907 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm))
2909 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
2910 && targetm.calls.split_complex_arg (TREE_TYPE (parm)))
2912 rtx tmp, real, imag;
2913 enum machine_mode inner = GET_MODE_INNER (DECL_MODE (parm));
2915 real = DECL_RTL (fnargs);
2916 imag = DECL_RTL (TREE_CHAIN (fnargs));
2917 if (inner != GET_MODE (real))
2919 real = gen_lowpart_SUBREG (inner, real);
2920 imag = gen_lowpart_SUBREG (inner, imag);
2923 if (TREE_ADDRESSABLE (parm))
2926 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (parm));
2928 /* split_complex_arg put the real and imag parts in
2929 pseudos. Move them to memory. */
2930 tmp = assign_stack_local (DECL_MODE (parm), size,
2931 TYPE_ALIGN (TREE_TYPE (parm)));
2932 set_mem_attributes (tmp, parm, 1);
2933 rmem = adjust_address_nv (tmp, inner, 0);
2934 imem = adjust_address_nv (tmp, inner, GET_MODE_SIZE (inner));
2935 push_to_sequence2 (all->first_conversion_insn,
2936 all->last_conversion_insn);
2937 emit_move_insn (rmem, real);
2938 emit_move_insn (imem, imag);
2939 all->first_conversion_insn = get_insns ();
2940 all->last_conversion_insn = get_last_insn ();
2944 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
2945 SET_DECL_RTL (parm, tmp);
2947 real = DECL_INCOMING_RTL (fnargs);
2948 imag = DECL_INCOMING_RTL (TREE_CHAIN (fnargs));
2949 if (inner != GET_MODE (real))
2951 real = gen_lowpart_SUBREG (inner, real);
2952 imag = gen_lowpart_SUBREG (inner, imag);
2954 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
2955 set_decl_incoming_rtl (parm, tmp, false);
2956 fnargs = TREE_CHAIN (fnargs);
2960 SET_DECL_RTL (parm, DECL_RTL (fnargs));
2961 set_decl_incoming_rtl (parm, DECL_INCOMING_RTL (fnargs), false);
2963 /* Set MEM_EXPR to the original decl, i.e. to PARM,
2964 instead of the copy of decl, i.e. FNARGS. */
2965 if (DECL_INCOMING_RTL (parm) && MEM_P (DECL_INCOMING_RTL (parm)))
2966 set_mem_expr (DECL_INCOMING_RTL (parm), parm);
2969 fnargs = TREE_CHAIN (fnargs);
2973 /* Assign RTL expressions to the function's parameters. This may involve
2974 copying them into registers and using those registers as the DECL_RTL. */
2977 assign_parms (tree fndecl)
2979 struct assign_parm_data_all all;
2982 current_function_internal_arg_pointer
2983 = targetm.calls.internal_arg_pointer ();
2985 assign_parms_initialize_all (&all);
2986 fnargs = assign_parms_augmented_arg_list (&all);
2988 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
2990 struct assign_parm_data_one data;
2992 /* Extract the type of PARM; adjust it according to ABI. */
2993 assign_parm_find_data_types (&all, parm, &data);
2995 /* Early out for errors and void parameters. */
2996 if (data.passed_mode == VOIDmode)
2998 SET_DECL_RTL (parm, const0_rtx);
2999 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
3003 if (current_function_stdarg && !TREE_CHAIN (parm))
3004 assign_parms_setup_varargs (&all, &data, false);
3006 /* Find out where the parameter arrives in this function. */
3007 assign_parm_find_entry_rtl (&all, &data);
3009 /* Find out where stack space for this parameter might be. */
3010 if (assign_parm_is_stack_parm (&all, &data))
3012 assign_parm_find_stack_rtl (parm, &data);
3013 assign_parm_adjust_entry_rtl (&data);
3016 /* Record permanently how this parm was passed. */
3017 set_decl_incoming_rtl (parm, data.entry_parm, data.passed_pointer);
3019 /* Update info on where next arg arrives in registers. */
3020 FUNCTION_ARG_ADVANCE (all.args_so_far, data.promoted_mode,
3021 data.passed_type, data.named_arg);
3023 assign_parm_adjust_stack_rtl (&data);
3025 if (assign_parm_setup_block_p (&data))
3026 assign_parm_setup_block (&all, parm, &data);
3027 else if (data.passed_pointer || use_register_for_decl (parm))
3028 assign_parm_setup_reg (&all, parm, &data);
3030 assign_parm_setup_stack (&all, parm, &data);
3033 if (targetm.calls.split_complex_arg && fnargs != all.orig_fnargs)
3034 assign_parms_unsplit_complex (&all, fnargs);
3036 /* Output all parameter conversion instructions (possibly including calls)
3037 now that all parameters have been copied out of hard registers. */
3038 emit_insn (all.first_conversion_insn);
3040 /* If we are receiving a struct value address as the first argument, set up
3041 the RTL for the function result. As this might require code to convert
3042 the transmitted address to Pmode, we do this here to ensure that possible
3043 preliminary conversions of the address have been emitted already. */
3044 if (all.function_result_decl)
3046 tree result = DECL_RESULT (current_function_decl);
3047 rtx addr = DECL_RTL (all.function_result_decl);
3050 if (DECL_BY_REFERENCE (result))
3054 addr = convert_memory_address (Pmode, addr);
3055 x = gen_rtx_MEM (DECL_MODE (result), addr);
3056 set_mem_attributes (x, result, 1);
3058 SET_DECL_RTL (result, x);
3061 /* We have aligned all the args, so add space for the pretend args. */
3062 current_function_pretend_args_size = all.pretend_args_size;
3063 all.stack_args_size.constant += all.extra_pretend_bytes;
3064 current_function_args_size = all.stack_args_size.constant;
3066 /* Adjust function incoming argument size for alignment and
3069 #ifdef REG_PARM_STACK_SPACE
3070 current_function_args_size = MAX (current_function_args_size,
3071 REG_PARM_STACK_SPACE (fndecl));
3074 current_function_args_size = CEIL_ROUND (current_function_args_size,
3075 PARM_BOUNDARY / BITS_PER_UNIT);
3077 #ifdef ARGS_GROW_DOWNWARD
3078 current_function_arg_offset_rtx
3079 = (all.stack_args_size.var == 0 ? GEN_INT (-all.stack_args_size.constant)
3080 : expand_expr (size_diffop (all.stack_args_size.var,
3081 size_int (-all.stack_args_size.constant)),
3082 NULL_RTX, VOIDmode, 0));
3084 current_function_arg_offset_rtx = ARGS_SIZE_RTX (all.stack_args_size);
3087 /* See how many bytes, if any, of its args a function should try to pop
3090 current_function_pops_args = RETURN_POPS_ARGS (fndecl, TREE_TYPE (fndecl),
3091 current_function_args_size);
3093 /* For stdarg.h function, save info about
3094 regs and stack space used by the named args. */
3096 current_function_args_info = all.args_so_far;
3098 /* Set the rtx used for the function return value. Put this in its
3099 own variable so any optimizers that need this information don't have
3100 to include tree.h. Do this here so it gets done when an inlined
3101 function gets output. */
3103 current_function_return_rtx
3104 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
3105 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
3107 /* If scalar return value was computed in a pseudo-reg, or was a named
3108 return value that got dumped to the stack, copy that to the hard
3110 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
3112 tree decl_result = DECL_RESULT (fndecl);
3113 rtx decl_rtl = DECL_RTL (decl_result);
3115 if (REG_P (decl_rtl)
3116 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
3117 : DECL_REGISTER (decl_result))
3121 real_decl_rtl = targetm.calls.function_value (TREE_TYPE (decl_result),
3123 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
3124 /* The delay slot scheduler assumes that current_function_return_rtx
3125 holds the hard register containing the return value, not a
3126 temporary pseudo. */
3127 current_function_return_rtx = real_decl_rtl;
3132 /* A subroutine of gimplify_parameters, invoked via walk_tree.
3133 For all seen types, gimplify their sizes. */
3136 gimplify_parm_type (tree *tp, int *walk_subtrees, void *data)
3143 if (POINTER_TYPE_P (t))
3145 else if (TYPE_SIZE (t) && !TREE_CONSTANT (TYPE_SIZE (t))
3146 && !TYPE_SIZES_GIMPLIFIED (t))
3148 gimplify_type_sizes (t, (tree *) data);
3156 /* Gimplify the parameter list for current_function_decl. This involves
3157 evaluating SAVE_EXPRs of variable sized parameters and generating code
3158 to implement callee-copies reference parameters. Returns a list of
3159 statements to add to the beginning of the function, or NULL if nothing
3163 gimplify_parameters (void)
3165 struct assign_parm_data_all all;
3166 tree fnargs, parm, stmts = NULL;
3168 assign_parms_initialize_all (&all);
3169 fnargs = assign_parms_augmented_arg_list (&all);
3171 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
3173 struct assign_parm_data_one data;
3175 /* Extract the type of PARM; adjust it according to ABI. */
3176 assign_parm_find_data_types (&all, parm, &data);
3178 /* Early out for errors and void parameters. */
3179 if (data.passed_mode == VOIDmode || DECL_SIZE (parm) == NULL)
3182 /* Update info on where next arg arrives in registers. */
3183 FUNCTION_ARG_ADVANCE (all.args_so_far, data.promoted_mode,
3184 data.passed_type, data.named_arg);
3186 /* ??? Once upon a time variable_size stuffed parameter list
3187 SAVE_EXPRs (amongst others) onto a pending sizes list. This
3188 turned out to be less than manageable in the gimple world.
3189 Now we have to hunt them down ourselves. */
3190 walk_tree_without_duplicates (&data.passed_type,
3191 gimplify_parm_type, &stmts);
3193 if (!TREE_CONSTANT (DECL_SIZE (parm)))
3195 gimplify_one_sizepos (&DECL_SIZE (parm), &stmts);
3196 gimplify_one_sizepos (&DECL_SIZE_UNIT (parm), &stmts);
3199 if (data.passed_pointer)
3201 tree type = TREE_TYPE (data.passed_type);
3202 if (reference_callee_copied (&all.args_so_far, TYPE_MODE (type),
3203 type, data.named_arg))
3207 /* For constant sized objects, this is trivial; for
3208 variable-sized objects, we have to play games. */
3209 if (TREE_CONSTANT (DECL_SIZE (parm)))
3211 local = create_tmp_var (type, get_name (parm));
3212 DECL_IGNORED_P (local) = 0;
3216 tree ptr_type, addr;
3218 ptr_type = build_pointer_type (type);
3219 addr = create_tmp_var (ptr_type, get_name (parm));
3220 DECL_IGNORED_P (addr) = 0;
3221 local = build_fold_indirect_ref (addr);
3223 t = built_in_decls[BUILT_IN_ALLOCA];
3224 t = build_call_expr (t, 1, DECL_SIZE_UNIT (parm));
3225 t = fold_convert (ptr_type, t);
3226 t = build_gimple_modify_stmt (addr, t);
3227 gimplify_and_add (t, &stmts);
3230 t = build_gimple_modify_stmt (local, parm);
3231 gimplify_and_add (t, &stmts);
3233 SET_DECL_VALUE_EXPR (parm, local);
3234 DECL_HAS_VALUE_EXPR_P (parm) = 1;
3242 /* Compute the size and offset from the start of the stacked arguments for a
3243 parm passed in mode PASSED_MODE and with type TYPE.
3245 INITIAL_OFFSET_PTR points to the current offset into the stacked
3248 The starting offset and size for this parm are returned in
3249 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
3250 nonzero, the offset is that of stack slot, which is returned in
3251 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
3252 padding required from the initial offset ptr to the stack slot.
3254 IN_REGS is nonzero if the argument will be passed in registers. It will
3255 never be set if REG_PARM_STACK_SPACE is not defined.
3257 FNDECL is the function in which the argument was defined.
3259 There are two types of rounding that are done. The first, controlled by
3260 FUNCTION_ARG_BOUNDARY, forces the offset from the start of the argument
3261 list to be aligned to the specific boundary (in bits). This rounding
3262 affects the initial and starting offsets, but not the argument size.
3264 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
3265 optionally rounds the size of the parm to PARM_BOUNDARY. The
3266 initial offset is not affected by this rounding, while the size always
3267 is and the starting offset may be. */
3269 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
3270 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
3271 callers pass in the total size of args so far as
3272 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
3275 locate_and_pad_parm (enum machine_mode passed_mode, tree type, int in_regs,
3276 int partial, tree fndecl ATTRIBUTE_UNUSED,
3277 struct args_size *initial_offset_ptr,
3278 struct locate_and_pad_arg_data *locate)
3281 enum direction where_pad;
3282 unsigned int boundary;
3283 int reg_parm_stack_space = 0;
3284 int part_size_in_regs;
3286 #ifdef REG_PARM_STACK_SPACE
3287 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
3289 /* If we have found a stack parm before we reach the end of the
3290 area reserved for registers, skip that area. */
3293 if (reg_parm_stack_space > 0)
3295 if (initial_offset_ptr->var)
3297 initial_offset_ptr->var
3298 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
3299 ssize_int (reg_parm_stack_space));
3300 initial_offset_ptr->constant = 0;
3302 else if (initial_offset_ptr->constant < reg_parm_stack_space)
3303 initial_offset_ptr->constant = reg_parm_stack_space;
3306 #endif /* REG_PARM_STACK_SPACE */
3308 part_size_in_regs = (reg_parm_stack_space == 0 ? partial : 0);
3311 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
3312 where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
3313 boundary = FUNCTION_ARG_BOUNDARY (passed_mode, type);
3314 locate->where_pad = where_pad;
3315 locate->boundary = boundary;
3317 /* Remember if the outgoing parameter requires extra alignment on the
3318 calling function side. */
3319 if (boundary > PREFERRED_STACK_BOUNDARY)
3320 boundary = PREFERRED_STACK_BOUNDARY;
3321 if (cfun->stack_alignment_needed < boundary)
3322 cfun->stack_alignment_needed = boundary;
3324 #ifdef ARGS_GROW_DOWNWARD
3325 locate->slot_offset.constant = -initial_offset_ptr->constant;
3326 if (initial_offset_ptr->var)
3327 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
3328 initial_offset_ptr->var);
3332 if (where_pad != none
3333 && (!host_integerp (sizetree, 1)
3334 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
3335 s2 = round_up (s2, PARM_BOUNDARY / BITS_PER_UNIT);
3336 SUB_PARM_SIZE (locate->slot_offset, s2);
3339 locate->slot_offset.constant += part_size_in_regs;
3342 #ifdef REG_PARM_STACK_SPACE
3343 || REG_PARM_STACK_SPACE (fndecl) > 0
3346 pad_to_arg_alignment (&locate->slot_offset, boundary,
3347 &locate->alignment_pad);
3349 locate->size.constant = (-initial_offset_ptr->constant
3350 - locate->slot_offset.constant);
3351 if (initial_offset_ptr->var)
3352 locate->size.var = size_binop (MINUS_EXPR,
3353 size_binop (MINUS_EXPR,
3355 initial_offset_ptr->var),
3356 locate->slot_offset.var);
3358 /* Pad_below needs the pre-rounded size to know how much to pad
3360 locate->offset = locate->slot_offset;
3361 if (where_pad == downward)
3362 pad_below (&locate->offset, passed_mode, sizetree);
3364 #else /* !ARGS_GROW_DOWNWARD */
3366 #ifdef REG_PARM_STACK_SPACE
3367 || REG_PARM_STACK_SPACE (fndecl) > 0
3370 pad_to_arg_alignment (initial_offset_ptr, boundary,
3371 &locate->alignment_pad);
3372 locate->slot_offset = *initial_offset_ptr;
3374 #ifdef PUSH_ROUNDING
3375 if (passed_mode != BLKmode)
3376 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
3379 /* Pad_below needs the pre-rounded size to know how much to pad below
3380 so this must be done before rounding up. */
3381 locate->offset = locate->slot_offset;
3382 if (where_pad == downward)
3383 pad_below (&locate->offset, passed_mode, sizetree);
3385 if (where_pad != none
3386 && (!host_integerp (sizetree, 1)
3387 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
3388 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3390 ADD_PARM_SIZE (locate->size, sizetree);
3392 locate->size.constant -= part_size_in_regs;
3393 #endif /* ARGS_GROW_DOWNWARD */
3396 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
3397 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
3400 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
3401 struct args_size *alignment_pad)
3403 tree save_var = NULL_TREE;
3404 HOST_WIDE_INT save_constant = 0;
3405 int boundary_in_bytes = boundary / BITS_PER_UNIT;
3406 HOST_WIDE_INT sp_offset = STACK_POINTER_OFFSET;
3408 #ifdef SPARC_STACK_BOUNDARY_HACK
3409 /* ??? The SPARC port may claim a STACK_BOUNDARY higher than
3410 the real alignment of %sp. However, when it does this, the
3411 alignment of %sp+STACK_POINTER_OFFSET is STACK_BOUNDARY. */
3412 if (SPARC_STACK_BOUNDARY_HACK)
3416 if (boundary > PARM_BOUNDARY)
3418 save_var = offset_ptr->var;
3419 save_constant = offset_ptr->constant;
3422 alignment_pad->var = NULL_TREE;
3423 alignment_pad->constant = 0;
3425 if (boundary > BITS_PER_UNIT)
3427 if (offset_ptr->var)
3429 tree sp_offset_tree = ssize_int (sp_offset);
3430 tree offset = size_binop (PLUS_EXPR,
3431 ARGS_SIZE_TREE (*offset_ptr),
3433 #ifdef ARGS_GROW_DOWNWARD
3434 tree rounded = round_down (offset, boundary / BITS_PER_UNIT);
3436 tree rounded = round_up (offset, boundary / BITS_PER_UNIT);
3439 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
3440 /* ARGS_SIZE_TREE includes constant term. */
3441 offset_ptr->constant = 0;
3442 if (boundary > PARM_BOUNDARY)
3443 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
3448 offset_ptr->constant = -sp_offset +
3449 #ifdef ARGS_GROW_DOWNWARD
3450 FLOOR_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
3452 CEIL_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
3454 if (boundary > PARM_BOUNDARY)
3455 alignment_pad->constant = offset_ptr->constant - save_constant;
3461 pad_below (struct args_size *offset_ptr, enum machine_mode passed_mode, tree sizetree)
3463 if (passed_mode != BLKmode)
3465 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
3466 offset_ptr->constant
3467 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
3468 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
3469 - GET_MODE_SIZE (passed_mode));
3473 if (TREE_CODE (sizetree) != INTEGER_CST
3474 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
3476 /* Round the size up to multiple of PARM_BOUNDARY bits. */
3477 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3479 ADD_PARM_SIZE (*offset_ptr, s2);
3480 SUB_PARM_SIZE (*offset_ptr, sizetree);
3486 /* True if register REGNO was alive at a place where `setjmp' was
3487 called and was set more than once or is an argument. Such regs may
3488 be clobbered by `longjmp'. */
3491 regno_clobbered_at_setjmp (bitmap setjmp_crosses, int regno)
3493 /* There appear to be cases where some local vars never reach the
3494 backend but have bogus regnos. */
3495 if (regno >= max_reg_num ())
3498 return ((REG_N_SETS (regno) > 1
3499 || REGNO_REG_SET_P (df_get_live_out (ENTRY_BLOCK_PTR), regno))
3500 && REGNO_REG_SET_P (setjmp_crosses, regno));
3503 /* Walk the tree of blocks describing the binding levels within a
3504 function and warn about variables the might be killed by setjmp or
3505 vfork. This is done after calling flow_analysis before register
3506 allocation since that will clobber the pseudo-regs to hard
3510 setjmp_vars_warning (bitmap setjmp_crosses, tree block)
3514 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
3516 if (TREE_CODE (decl) == VAR_DECL
3517 && DECL_RTL_SET_P (decl)
3518 && REG_P (DECL_RTL (decl))
3519 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
3520 warning (OPT_Wclobbered, "variable %q+D might be clobbered by"
3521 " %<longjmp%> or %<vfork%>", decl);
3524 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = BLOCK_CHAIN (sub))
3525 setjmp_vars_warning (setjmp_crosses, sub);
3528 /* Do the appropriate part of setjmp_vars_warning
3529 but for arguments instead of local variables. */
3532 setjmp_args_warning (bitmap setjmp_crosses)
3535 for (decl = DECL_ARGUMENTS (current_function_decl);
3536 decl; decl = TREE_CHAIN (decl))
3537 if (DECL_RTL (decl) != 0
3538 && REG_P (DECL_RTL (decl))
3539 && regno_clobbered_at_setjmp (setjmp_crosses, REGNO (DECL_RTL (decl))))
3540 warning (OPT_Wclobbered,
3541 "argument %q+D might be clobbered by %<longjmp%> or %<vfork%>",
3545 /* Generate warning messages for variables live across setjmp. */
3548 generate_setjmp_warnings (void)
3550 bitmap setjmp_crosses = regstat_get_setjmp_crosses ();
3552 if (n_basic_blocks == NUM_FIXED_BLOCKS
3553 || bitmap_empty_p (setjmp_crosses))
3556 setjmp_vars_warning (setjmp_crosses, DECL_INITIAL (current_function_decl));
3557 setjmp_args_warning (setjmp_crosses);
3561 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
3562 and create duplicate blocks. */
3563 /* ??? Need an option to either create block fragments or to create
3564 abstract origin duplicates of a source block. It really depends
3565 on what optimization has been performed. */
3568 reorder_blocks (void)
3570 tree block = DECL_INITIAL (current_function_decl);
3571 VEC(tree,heap) *block_stack;
3573 if (block == NULL_TREE)
3576 block_stack = VEC_alloc (tree, heap, 10);
3578 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
3579 clear_block_marks (block);
3581 /* Prune the old trees away, so that they don't get in the way. */
3582 BLOCK_SUBBLOCKS (block) = NULL_TREE;
3583 BLOCK_CHAIN (block) = NULL_TREE;
3585 /* Recreate the block tree from the note nesting. */
3586 reorder_blocks_1 (get_insns (), block, &block_stack);
3587 BLOCK_SUBBLOCKS (block) = blocks_nreverse (BLOCK_SUBBLOCKS (block));
3589 VEC_free (tree, heap, block_stack);
3592 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
3595 clear_block_marks (tree block)
3599 TREE_ASM_WRITTEN (block) = 0;
3600 clear_block_marks (BLOCK_SUBBLOCKS (block));
3601 block = BLOCK_CHAIN (block);
3606 reorder_blocks_1 (rtx insns, tree current_block, VEC(tree,heap) **p_block_stack)
3610 for (insn = insns; insn; insn = NEXT_INSN (insn))
3614 if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_BEG)
3616 tree block = NOTE_BLOCK (insn);
3619 origin = (BLOCK_FRAGMENT_ORIGIN (block)
3620 ? BLOCK_FRAGMENT_ORIGIN (block)
3623 /* If we have seen this block before, that means it now
3624 spans multiple address regions. Create a new fragment. */
3625 if (TREE_ASM_WRITTEN (block))
3627 tree new_block = copy_node (block);
3629 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
3630 BLOCK_FRAGMENT_CHAIN (new_block)
3631 = BLOCK_FRAGMENT_CHAIN (origin);
3632 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
3634 NOTE_BLOCK (insn) = new_block;
3638 BLOCK_SUBBLOCKS (block) = 0;
3639 TREE_ASM_WRITTEN (block) = 1;
3640 /* When there's only one block for the entire function,
3641 current_block == block and we mustn't do this, it
3642 will cause infinite recursion. */
3643 if (block != current_block)
3645 if (block != origin)
3646 gcc_assert (BLOCK_SUPERCONTEXT (origin) == current_block);
3648 BLOCK_SUPERCONTEXT (block) = current_block;
3649 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
3650 BLOCK_SUBBLOCKS (current_block) = block;
3651 current_block = origin;
3653 VEC_safe_push (tree, heap, *p_block_stack, block);
3655 else if (NOTE_KIND (insn) == NOTE_INSN_BLOCK_END)
3657 NOTE_BLOCK (insn) = VEC_pop (tree, *p_block_stack);
3658 BLOCK_SUBBLOCKS (current_block)
3659 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block));
3660 current_block = BLOCK_SUPERCONTEXT (current_block);
3666 /* Reverse the order of elements in the chain T of blocks,
3667 and return the new head of the chain (old last element). */
3670 blocks_nreverse (tree t)
3672 tree prev = 0, decl, next;
3673 for (decl = t; decl; decl = next)
3675 next = BLOCK_CHAIN (decl);
3676 BLOCK_CHAIN (decl) = prev;
3682 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
3683 non-NULL, list them all into VECTOR, in a depth-first preorder
3684 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
3688 all_blocks (tree block, tree *vector)
3694 TREE_ASM_WRITTEN (block) = 0;
3696 /* Record this block. */
3698 vector[n_blocks] = block;
3702 /* Record the subblocks, and their subblocks... */
3703 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
3704 vector ? vector + n_blocks : 0);
3705 block = BLOCK_CHAIN (block);
3711 /* Return a vector containing all the blocks rooted at BLOCK. The
3712 number of elements in the vector is stored in N_BLOCKS_P. The
3713 vector is dynamically allocated; it is the caller's responsibility
3714 to call `free' on the pointer returned. */
3717 get_block_vector (tree block, int *n_blocks_p)
3721 *n_blocks_p = all_blocks (block, NULL);
3722 block_vector = XNEWVEC (tree, *n_blocks_p);
3723 all_blocks (block, block_vector);
3725 return block_vector;
3728 static GTY(()) int next_block_index = 2;
3730 /* Set BLOCK_NUMBER for all the blocks in FN. */
3733 number_blocks (tree fn)
3739 /* For SDB and XCOFF debugging output, we start numbering the blocks
3740 from 1 within each function, rather than keeping a running
3742 #if defined (SDB_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
3743 if (write_symbols == SDB_DEBUG || write_symbols == XCOFF_DEBUG)
3744 next_block_index = 1;
3747 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
3749 /* The top-level BLOCK isn't numbered at all. */
3750 for (i = 1; i < n_blocks; ++i)
3751 /* We number the blocks from two. */
3752 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
3754 free (block_vector);
3759 /* If VAR is present in a subblock of BLOCK, return the subblock. */
3762 debug_find_var_in_block_tree (tree var, tree block)
3766 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
3770 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
3772 tree ret = debug_find_var_in_block_tree (var, t);
3780 /* Keep track of whether we're in a dummy function context. If we are,
3781 we don't want to invoke the set_current_function hook, because we'll
3782 get into trouble if the hook calls target_reinit () recursively or
3783 when the initial initialization is not yet complete. */
3785 static bool in_dummy_function;
3787 /* Invoke the target hook when setting cfun. */
3790 invoke_set_current_function_hook (tree fndecl)
3792 if (!in_dummy_function)
3793 targetm.set_current_function (fndecl);
3796 /* cfun should never be set directly; use this function. */
3799 set_cfun (struct function *new_cfun)
3801 if (cfun != new_cfun)
3804 invoke_set_current_function_hook (new_cfun ? new_cfun->decl : NULL_TREE);
3808 /* Keep track of the cfun stack. */
3810 typedef struct function *function_p;
3812 DEF_VEC_P(function_p);
3813 DEF_VEC_ALLOC_P(function_p,heap);
3815 /* Initialized with NOGC, making this poisonous to the garbage collector. */
3817 static VEC(function_p,heap) *cfun_stack;
3819 /* We save the value of in_system_header here when pushing the first
3820 function on the cfun stack, and we restore it from here when
3821 popping the last function. */
3823 static bool saved_in_system_header;
3825 /* Push the current cfun onto the stack, and set cfun to new_cfun. */
3828 push_cfun (struct function *new_cfun)
3831 saved_in_system_header = in_system_header;
3832 VEC_safe_push (function_p, heap, cfun_stack, cfun);
3834 in_system_header = DECL_IN_SYSTEM_HEADER (new_cfun->decl);
3835 set_cfun (new_cfun);
3838 /* Pop cfun from the stack. */
3843 struct function *new_cfun = VEC_pop (function_p, cfun_stack);
3844 in_system_header = ((new_cfun == NULL) ? saved_in_system_header
3845 : DECL_IN_SYSTEM_HEADER (new_cfun->decl));
3846 set_cfun (new_cfun);
3849 /* Return value of funcdef and increase it. */
3851 get_next_funcdef_no (void)
3853 return funcdef_no++;
3856 /* Allocate a function structure for FNDECL and set its contents
3857 to the defaults. Set cfun to the newly-allocated object.
3858 Some of the helper functions invoked during initialization assume
3859 that cfun has already been set. Therefore, assign the new object
3860 directly into cfun and invoke the back end hook explicitly at the
3861 very end, rather than initializing a temporary and calling set_cfun
3864 ABSTRACT_P is true if this is a function that will never be seen by
3865 the middle-end. Such functions are front-end concepts (like C++
3866 function templates) that do not correspond directly to functions
3867 placed in object files. */
3870 allocate_struct_function (tree fndecl, bool abstract_p)
3873 tree fntype = fndecl ? TREE_TYPE (fndecl) : NULL_TREE;
3875 cfun = ggc_alloc_cleared (sizeof (struct function));
3877 cfun->stack_alignment_needed = STACK_BOUNDARY;
3878 cfun->preferred_stack_boundary = STACK_BOUNDARY;
3880 current_function_funcdef_no = get_next_funcdef_no ();
3882 cfun->function_frequency = FUNCTION_FREQUENCY_NORMAL;
3884 init_eh_for_function ();
3886 lang_hooks.function.init (cfun);
3887 if (init_machine_status)
3888 cfun->machine = (*init_machine_status) ();
3892 DECL_STRUCT_FUNCTION (fndecl) = cfun;
3893 cfun->decl = fndecl;
3895 result = DECL_RESULT (fndecl);
3896 if (!abstract_p && aggregate_value_p (result, fndecl))
3898 #ifdef PCC_STATIC_STRUCT_RETURN
3899 current_function_returns_pcc_struct = 1;
3901 current_function_returns_struct = 1;
3904 current_function_stdarg
3906 && TYPE_ARG_TYPES (fntype) != 0
3907 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
3908 != void_type_node));
3910 /* Assume all registers in stdarg functions need to be saved. */
3911 cfun->va_list_gpr_size = VA_LIST_MAX_GPR_SIZE;
3912 cfun->va_list_fpr_size = VA_LIST_MAX_FPR_SIZE;
3915 invoke_set_current_function_hook (fndecl);
3918 /* This is like allocate_struct_function, but pushes a new cfun for FNDECL
3919 instead of just setting it. */
3922 push_struct_function (tree fndecl)
3925 saved_in_system_header = in_system_header;
3926 VEC_safe_push (function_p, heap, cfun_stack, cfun);
3928 in_system_header = DECL_IN_SYSTEM_HEADER (fndecl);
3929 allocate_struct_function (fndecl, false);
3932 /* Reset cfun, and other non-struct-function variables to defaults as
3933 appropriate for emitting rtl at the start of a function. */
3936 prepare_function_start (void)
3939 init_varasm_status ();
3942 cse_not_expected = ! optimize;
3944 /* Caller save not needed yet. */
3945 caller_save_needed = 0;
3947 /* We haven't done register allocation yet. */
3950 /* Indicate that we have not instantiated virtual registers yet. */
3951 virtuals_instantiated = 0;
3953 /* Indicate that we want CONCATs now. */
3954 generating_concat_p = 1;
3956 /* Indicate we have no need of a frame pointer yet. */
3957 frame_pointer_needed = 0;
3960 /* Initialize the rtl expansion mechanism so that we can do simple things
3961 like generate sequences. This is used to provide a context during global
3962 initialization of some passes. You must call expand_dummy_function_end
3963 to exit this context. */
3966 init_dummy_function_start (void)
3968 gcc_assert (!in_dummy_function);
3969 in_dummy_function = true;
3970 push_struct_function (NULL_TREE);
3971 prepare_function_start ();
3974 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
3975 and initialize static variables for generating RTL for the statements
3979 init_function_start (tree subr)
3981 if (subr && DECL_STRUCT_FUNCTION (subr))
3982 set_cfun (DECL_STRUCT_FUNCTION (subr));
3984 allocate_struct_function (subr, false);
3985 prepare_function_start ();
3987 /* Warn if this value is an aggregate type,
3988 regardless of which calling convention we are using for it. */
3989 if (AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
3990 warning (OPT_Waggregate_return, "function returns an aggregate");
3993 /* Make sure all values used by the optimization passes have sane
3996 init_function_for_compilation (void)
4000 /* No prologue/epilogue insns yet. Make sure that these vectors are
4002 gcc_assert (VEC_length (int, prologue) == 0);
4003 gcc_assert (VEC_length (int, epilogue) == 0);
4004 gcc_assert (VEC_length (int, sibcall_epilogue) == 0);
4008 struct rtl_opt_pass pass_init_function =
4014 init_function_for_compilation, /* execute */
4017 0, /* static_pass_number */
4019 0, /* properties_required */
4020 0, /* properties_provided */
4021 0, /* properties_destroyed */
4022 0, /* todo_flags_start */
4023 0 /* todo_flags_finish */
4029 expand_main_function (void)
4031 #if (defined(INVOKE__main) \
4032 || (!defined(HAS_INIT_SECTION) \
4033 && !defined(INIT_SECTION_ASM_OP) \
4034 && !defined(INIT_ARRAY_SECTION_ASM_OP)))
4035 emit_library_call (init_one_libfunc (NAME__MAIN), LCT_NORMAL, VOIDmode, 0);
4039 /* Expand code to initialize the stack_protect_guard. This is invoked at
4040 the beginning of a function to be protected. */
4042 #ifndef HAVE_stack_protect_set
4043 # define HAVE_stack_protect_set 0
4044 # define gen_stack_protect_set(x,y) (gcc_unreachable (), NULL_RTX)
4048 stack_protect_prologue (void)
4050 tree guard_decl = targetm.stack_protect_guard ();
4053 /* Avoid expand_expr here, because we don't want guard_decl pulled
4054 into registers unless absolutely necessary. And we know that
4055 cfun->stack_protect_guard is a local stack slot, so this skips
4057 x = validize_mem (DECL_RTL (cfun->stack_protect_guard));
4058 y = validize_mem (DECL_RTL (guard_decl));
4060 /* Allow the target to copy from Y to X without leaking Y into a
4062 if (HAVE_stack_protect_set)
4064 rtx insn = gen_stack_protect_set (x, y);
4072 /* Otherwise do a straight move. */
4073 emit_move_insn (x, y);
4076 /* Expand code to verify the stack_protect_guard. This is invoked at
4077 the end of a function to be protected. */
4079 #ifndef HAVE_stack_protect_test
4080 # define HAVE_stack_protect_test 0
4081 # define gen_stack_protect_test(x, y, z) (gcc_unreachable (), NULL_RTX)
4085 stack_protect_epilogue (void)
4087 tree guard_decl = targetm.stack_protect_guard ();
4088 rtx label = gen_label_rtx ();
4091 /* Avoid expand_expr here, because we don't want guard_decl pulled
4092 into registers unless absolutely necessary. And we know that
4093 cfun->stack_protect_guard is a local stack slot, so this skips
4095 x = validize_mem (DECL_RTL (cfun->stack_protect_guard));
4096 y = validize_mem (DECL_RTL (guard_decl));
4098 /* Allow the target to compare Y with X without leaking either into
4100 switch (HAVE_stack_protect_test != 0)
4103 tmp = gen_stack_protect_test (x, y, label);
4112 emit_cmp_and_jump_insns (x, y, EQ, NULL_RTX, ptr_mode, 1, label);
4116 /* The noreturn predictor has been moved to the tree level. The rtl-level
4117 predictors estimate this branch about 20%, which isn't enough to get
4118 things moved out of line. Since this is the only extant case of adding
4119 a noreturn function at the rtl level, it doesn't seem worth doing ought
4120 except adding the prediction by hand. */
4121 tmp = get_last_insn ();
4123 predict_insn_def (tmp, PRED_NORETURN, TAKEN);
4125 expand_expr_stmt (targetm.stack_protect_fail ());
4129 /* Start the RTL for a new function, and set variables used for
4131 SUBR is the FUNCTION_DECL node.
4132 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
4133 the function's parameters, which must be run at any return statement. */
4136 expand_function_start (tree subr)
4138 /* Make sure volatile mem refs aren't considered
4139 valid operands of arithmetic insns. */
4140 init_recog_no_volatile ();
4142 current_function_profile
4144 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
4146 current_function_limit_stack
4147 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
4149 /* Make the label for return statements to jump to. Do not special
4150 case machines with special return instructions -- they will be
4151 handled later during jump, ifcvt, or epilogue creation. */
4152 return_label = gen_label_rtx ();
4154 /* Initialize rtx used to return the value. */
4155 /* Do this before assign_parms so that we copy the struct value address
4156 before any library calls that assign parms might generate. */
4158 /* Decide whether to return the value in memory or in a register. */
4159 if (aggregate_value_p (DECL_RESULT (subr), subr))
4161 /* Returning something that won't go in a register. */
4162 rtx value_address = 0;
4164 #ifdef PCC_STATIC_STRUCT_RETURN
4165 if (current_function_returns_pcc_struct)
4167 int size = int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr)));
4168 value_address = assemble_static_space (size);
4173 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 2);
4174 /* Expect to be passed the address of a place to store the value.
4175 If it is passed as an argument, assign_parms will take care of
4179 value_address = gen_reg_rtx (Pmode);
4180 emit_move_insn (value_address, sv);
4185 rtx x = value_address;
4186 if (!DECL_BY_REFERENCE (DECL_RESULT (subr)))
4188 x = gen_rtx_MEM (DECL_MODE (DECL_RESULT (subr)), x);
4189 set_mem_attributes (x, DECL_RESULT (subr), 1);
4191 SET_DECL_RTL (DECL_RESULT (subr), x);
4194 else if (DECL_MODE (DECL_RESULT (subr)) == VOIDmode)
4195 /* If return mode is void, this decl rtl should not be used. */
4196 SET_DECL_RTL (DECL_RESULT (subr), NULL_RTX);
4199 /* Compute the return values into a pseudo reg, which we will copy
4200 into the true return register after the cleanups are done. */
4201 tree return_type = TREE_TYPE (DECL_RESULT (subr));
4202 if (TYPE_MODE (return_type) != BLKmode
4203 && targetm.calls.return_in_msb (return_type))
4204 /* expand_function_end will insert the appropriate padding in
4205 this case. Use the return value's natural (unpadded) mode
4206 within the function proper. */
4207 SET_DECL_RTL (DECL_RESULT (subr),
4208 gen_reg_rtx (TYPE_MODE (return_type)));
4211 /* In order to figure out what mode to use for the pseudo, we
4212 figure out what the mode of the eventual return register will
4213 actually be, and use that. */
4214 rtx hard_reg = hard_function_value (return_type, subr, 0, 1);
4216 /* Structures that are returned in registers are not
4217 aggregate_value_p, so we may see a PARALLEL or a REG. */
4218 if (REG_P (hard_reg))
4219 SET_DECL_RTL (DECL_RESULT (subr),
4220 gen_reg_rtx (GET_MODE (hard_reg)));
4223 gcc_assert (GET_CODE (hard_reg) == PARALLEL);
4224 SET_DECL_RTL (DECL_RESULT (subr), gen_group_rtx (hard_reg));
4228 /* Set DECL_REGISTER flag so that expand_function_end will copy the
4229 result to the real return register(s). */
4230 DECL_REGISTER (DECL_RESULT (subr)) = 1;
4233 /* Initialize rtx for parameters and local variables.
4234 In some cases this requires emitting insns. */
4235 assign_parms (subr);
4237 /* If function gets a static chain arg, store it. */
4238 if (cfun->static_chain_decl)
4240 tree parm = cfun->static_chain_decl;
4241 rtx local = gen_reg_rtx (Pmode);
4243 set_decl_incoming_rtl (parm, static_chain_incoming_rtx, false);
4244 SET_DECL_RTL (parm, local);
4245 mark_reg_pointer (local, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
4247 emit_move_insn (local, static_chain_incoming_rtx);
4250 /* If the function receives a non-local goto, then store the
4251 bits we need to restore the frame pointer. */
4252 if (cfun->nonlocal_goto_save_area)
4257 /* ??? We need to do this save early. Unfortunately here is
4258 before the frame variable gets declared. Help out... */
4259 expand_var (TREE_OPERAND (cfun->nonlocal_goto_save_area, 0));
4261 t_save = build4 (ARRAY_REF, ptr_type_node,
4262 cfun->nonlocal_goto_save_area,
4263 integer_zero_node, NULL_TREE, NULL_TREE);
4264 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
4265 r_save = convert_memory_address (Pmode, r_save);
4267 emit_move_insn (r_save, virtual_stack_vars_rtx);
4268 update_nonlocal_goto_save_area ();
4271 /* The following was moved from init_function_start.
4272 The move is supposed to make sdb output more accurate. */
4273 /* Indicate the beginning of the function body,
4274 as opposed to parm setup. */
4275 emit_note (NOTE_INSN_FUNCTION_BEG);
4277 gcc_assert (NOTE_P (get_last_insn ()));
4279 parm_birth_insn = get_last_insn ();
4281 if (current_function_profile)
4284 PROFILE_HOOK (current_function_funcdef_no);
4288 /* After the display initializations is where the stack checking
4290 if(flag_stack_check)
4291 stack_check_probe_note = emit_note (NOTE_INSN_DELETED);
4293 /* Make sure there is a line number after the function entry setup code. */
4294 force_next_line_note ();
4297 /* Undo the effects of init_dummy_function_start. */
4299 expand_dummy_function_end (void)
4301 gcc_assert (in_dummy_function);
4303 /* End any sequences that failed to be closed due to syntax errors. */
4304 while (in_sequence_p ())
4307 /* Outside function body, can't compute type's actual size
4308 until next function's body starts. */
4310 free_after_parsing (cfun);
4311 free_after_compilation (cfun);
4313 in_dummy_function = false;
4316 /* Call DOIT for each hard register used as a return value from
4317 the current function. */
4320 diddle_return_value (void (*doit) (rtx, void *), void *arg)
4322 rtx outgoing = current_function_return_rtx;
4327 if (REG_P (outgoing))
4328 (*doit) (outgoing, arg);
4329 else if (GET_CODE (outgoing) == PARALLEL)
4333 for (i = 0; i < XVECLEN (outgoing, 0); i++)
4335 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
4337 if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
4344 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
4346 emit_insn (gen_rtx_CLOBBER (VOIDmode, reg));
4350 clobber_return_register (void)
4352 diddle_return_value (do_clobber_return_reg, NULL);
4354 /* In case we do use pseudo to return value, clobber it too. */
4355 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
4357 tree decl_result = DECL_RESULT (current_function_decl);
4358 rtx decl_rtl = DECL_RTL (decl_result);
4359 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
4361 do_clobber_return_reg (decl_rtl, NULL);
4367 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
4369 emit_insn (gen_rtx_USE (VOIDmode, reg));
4373 use_return_register (void)
4375 diddle_return_value (do_use_return_reg, NULL);
4378 /* Possibly warn about unused parameters. */
4380 do_warn_unused_parameter (tree fn)
4384 for (decl = DECL_ARGUMENTS (fn);
4385 decl; decl = TREE_CHAIN (decl))
4386 if (!TREE_USED (decl) && TREE_CODE (decl) == PARM_DECL
4387 && DECL_NAME (decl) && !DECL_ARTIFICIAL (decl)
4388 && !TREE_NO_WARNING (decl))
4389 warning (OPT_Wunused_parameter, "unused parameter %q+D", decl);
4392 static GTY(()) rtx initial_trampoline;
4394 /* Generate RTL for the end of the current function. */
4397 expand_function_end (void)
4401 /* If arg_pointer_save_area was referenced only from a nested
4402 function, we will not have initialized it yet. Do that now. */
4403 if (arg_pointer_save_area && ! cfun->arg_pointer_save_area_init)
4404 get_arg_pointer_save_area ();
4406 /* If we are doing stack checking and this function makes calls,
4407 do a stack probe at the start of the function to ensure we have enough
4408 space for another stack frame. */
4409 if (flag_stack_check && ! STACK_CHECK_BUILTIN)
4413 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
4417 probe_stack_range (STACK_CHECK_PROTECT,
4418 GEN_INT (STACK_CHECK_MAX_FRAME_SIZE));
4421 emit_insn_before (seq, stack_check_probe_note);
4426 /* End any sequences that failed to be closed due to syntax errors. */
4427 while (in_sequence_p ())
4430 clear_pending_stack_adjust ();
4431 do_pending_stack_adjust ();
4433 /* Output a linenumber for the end of the function.
4434 SDB depends on this. */
4435 force_next_line_note ();
4436 set_curr_insn_source_location (input_location);
4438 /* Before the return label (if any), clobber the return
4439 registers so that they are not propagated live to the rest of
4440 the function. This can only happen with functions that drop
4441 through; if there had been a return statement, there would
4442 have either been a return rtx, or a jump to the return label.
4444 We delay actual code generation after the current_function_value_rtx
4446 clobber_after = get_last_insn ();
4448 /* Output the label for the actual return from the function. */
4449 emit_label (return_label);
4451 if (USING_SJLJ_EXCEPTIONS)
4453 /* Let except.c know where it should emit the call to unregister
4454 the function context for sjlj exceptions. */
4455 if (flag_exceptions)
4456 sjlj_emit_function_exit_after (get_last_insn ());
4460 /* We want to ensure that instructions that may trap are not
4461 moved into the epilogue by scheduling, because we don't
4462 always emit unwind information for the epilogue. */
4463 if (flag_non_call_exceptions)
4464 emit_insn (gen_blockage ());
4467 /* If this is an implementation of throw, do what's necessary to
4468 communicate between __builtin_eh_return and the epilogue. */
4469 expand_eh_return ();
4471 /* If scalar return value was computed in a pseudo-reg, or was a named
4472 return value that got dumped to the stack, copy that to the hard
4474 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
4476 tree decl_result = DECL_RESULT (current_function_decl);
4477 rtx decl_rtl = DECL_RTL (decl_result);
4479 if (REG_P (decl_rtl)
4480 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
4481 : DECL_REGISTER (decl_result))
4483 rtx real_decl_rtl = current_function_return_rtx;
4485 /* This should be set in assign_parms. */
4486 gcc_assert (REG_FUNCTION_VALUE_P (real_decl_rtl));
4488 /* If this is a BLKmode structure being returned in registers,
4489 then use the mode computed in expand_return. Note that if
4490 decl_rtl is memory, then its mode may have been changed,
4491 but that current_function_return_rtx has not. */
4492 if (GET_MODE (real_decl_rtl) == BLKmode)
4493 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
4495 /* If a non-BLKmode return value should be padded at the least
4496 significant end of the register, shift it left by the appropriate
4497 amount. BLKmode results are handled using the group load/store
4499 if (TYPE_MODE (TREE_TYPE (decl_result)) != BLKmode
4500 && targetm.calls.return_in_msb (TREE_TYPE (decl_result)))
4502 emit_move_insn (gen_rtx_REG (GET_MODE (decl_rtl),
4503 REGNO (real_decl_rtl)),
4505 shift_return_value (GET_MODE (decl_rtl), true, real_decl_rtl);
4507 /* If a named return value dumped decl_return to memory, then
4508 we may need to re-do the PROMOTE_MODE signed/unsigned
4510 else if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
4512 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
4514 if (targetm.calls.promote_function_return (TREE_TYPE (current_function_decl)))
4515 promote_mode (TREE_TYPE (decl_result), GET_MODE (decl_rtl),
4518 convert_move (real_decl_rtl, decl_rtl, unsignedp);
4520 else if (GET_CODE (real_decl_rtl) == PARALLEL)
4522 /* If expand_function_start has created a PARALLEL for decl_rtl,
4523 move the result to the real return registers. Otherwise, do
4524 a group load from decl_rtl for a named return. */
4525 if (GET_CODE (decl_rtl) == PARALLEL)
4526 emit_group_move (real_decl_rtl, decl_rtl);
4528 emit_group_load (real_decl_rtl, decl_rtl,
4529 TREE_TYPE (decl_result),
4530 int_size_in_bytes (TREE_TYPE (decl_result)));
4532 /* In the case of complex integer modes smaller than a word, we'll
4533 need to generate some non-trivial bitfield insertions. Do that
4534 on a pseudo and not the hard register. */
4535 else if (GET_CODE (decl_rtl) == CONCAT
4536 && GET_MODE_CLASS (GET_MODE (decl_rtl)) == MODE_COMPLEX_INT
4537 && GET_MODE_BITSIZE (GET_MODE (decl_rtl)) <= BITS_PER_WORD)
4539 int old_generating_concat_p;
4542 old_generating_concat_p = generating_concat_p;
4543 generating_concat_p = 0;
4544 tmp = gen_reg_rtx (GET_MODE (decl_rtl));
4545 generating_concat_p = old_generating_concat_p;
4547 emit_move_insn (tmp, decl_rtl);
4548 emit_move_insn (real_decl_rtl, tmp);
4551 emit_move_insn (real_decl_rtl, decl_rtl);
4555 /* If returning a structure, arrange to return the address of the value
4556 in a place where debuggers expect to find it.
4558 If returning a structure PCC style,
4559 the caller also depends on this value.
4560 And current_function_returns_pcc_struct is not necessarily set. */
4561 if (current_function_returns_struct
4562 || current_function_returns_pcc_struct)
4564 rtx value_address = DECL_RTL (DECL_RESULT (current_function_decl));
4565 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
4568 if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
4569 type = TREE_TYPE (type);
4571 value_address = XEXP (value_address, 0);
4573 outgoing = targetm.calls.function_value (build_pointer_type (type),
4574 current_function_decl, true);
4576 /* Mark this as a function return value so integrate will delete the
4577 assignment and USE below when inlining this function. */
4578 REG_FUNCTION_VALUE_P (outgoing) = 1;
4580 /* The address may be ptr_mode and OUTGOING may be Pmode. */
4581 value_address = convert_memory_address (GET_MODE (outgoing),
4584 emit_move_insn (outgoing, value_address);
4586 /* Show return register used to hold result (in this case the address
4588 current_function_return_rtx = outgoing;
4591 /* Emit the actual code to clobber return register. */
4596 clobber_return_register ();
4597 expand_naked_return ();
4601 emit_insn_after (seq, clobber_after);
4604 /* Output the label for the naked return from the function. */
4605 emit_label (naked_return_label);
4607 /* @@@ This is a kludge. We want to ensure that instructions that
4608 may trap are not moved into the epilogue by scheduling, because
4609 we don't always emit unwind information for the epilogue. */
4610 if (! USING_SJLJ_EXCEPTIONS && flag_non_call_exceptions)
4611 emit_insn (gen_blockage ());
4613 /* If stack protection is enabled for this function, check the guard. */
4614 if (cfun->stack_protect_guard)
4615 stack_protect_epilogue ();
4617 /* If we had calls to alloca, and this machine needs
4618 an accurate stack pointer to exit the function,
4619 insert some code to save and restore the stack pointer. */
4620 if (! EXIT_IGNORE_STACK
4621 && current_function_calls_alloca)
4625 emit_stack_save (SAVE_FUNCTION, &tem, parm_birth_insn);
4626 emit_stack_restore (SAVE_FUNCTION, tem, NULL_RTX);
4629 /* ??? This should no longer be necessary since stupid is no longer with
4630 us, but there are some parts of the compiler (eg reload_combine, and
4631 sh mach_dep_reorg) that still try and compute their own lifetime info
4632 instead of using the general framework. */
4633 use_return_register ();
4637 get_arg_pointer_save_area (void)
4639 rtx ret = arg_pointer_save_area;
4643 ret = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
4644 arg_pointer_save_area = ret;
4647 if (! cfun->arg_pointer_save_area_init)
4651 /* Save the arg pointer at the beginning of the function. The
4652 generated stack slot may not be a valid memory address, so we
4653 have to check it and fix it if necessary. */
4655 emit_move_insn (validize_mem (ret), virtual_incoming_args_rtx);
4659 push_topmost_sequence ();
4660 emit_insn_after (seq, entry_of_function ());
4661 pop_topmost_sequence ();
4667 /* Extend a vector that records the INSN_UIDs of INSNS
4668 (a list of one or more insns). */
4671 record_insns (rtx insns, VEC(int,heap) **vecp)
4675 for (tmp = insns; tmp != NULL_RTX; tmp = NEXT_INSN (tmp))
4676 VEC_safe_push (int, heap, *vecp, INSN_UID (tmp));
4679 /* Set the locator of the insn chain starting at INSN to LOC. */
4681 set_insn_locators (rtx insn, int loc)
4683 while (insn != NULL_RTX)
4686 INSN_LOCATOR (insn) = loc;
4687 insn = NEXT_INSN (insn);
4691 /* Determine how many INSN_UIDs in VEC are part of INSN. Because we can
4692 be running after reorg, SEQUENCE rtl is possible. */
4695 contains (const_rtx insn, VEC(int,heap) **vec)
4699 if (NONJUMP_INSN_P (insn)
4700 && GET_CODE (PATTERN (insn)) == SEQUENCE)
4703 for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
4704 for (j = VEC_length (int, *vec) - 1; j >= 0; --j)
4705 if (INSN_UID (XVECEXP (PATTERN (insn), 0, i))
4706 == VEC_index (int, *vec, j))
4712 for (j = VEC_length (int, *vec) - 1; j >= 0; --j)
4713 if (INSN_UID (insn) == VEC_index (int, *vec, j))
4720 prologue_epilogue_contains (const_rtx insn)
4722 if (contains (insn, &prologue))
4724 if (contains (insn, &epilogue))
4730 sibcall_epilogue_contains (const_rtx insn)
4732 if (sibcall_epilogue)
4733 return contains (insn, &sibcall_epilogue);
4738 /* Insert gen_return at the end of block BB. This also means updating
4739 block_for_insn appropriately. */
4742 emit_return_into_block (basic_block bb)
4744 emit_jump_insn_after (gen_return (), BB_END (bb));
4746 #endif /* HAVE_return */
4748 #if defined(HAVE_epilogue) && defined(INCOMING_RETURN_ADDR_RTX)
4750 /* These functions convert the epilogue into a variant that does not
4751 modify the stack pointer. This is used in cases where a function
4752 returns an object whose size is not known until it is computed.
4753 The called function leaves the object on the stack, leaves the
4754 stack depressed, and returns a pointer to the object.
4756 What we need to do is track all modifications and references to the
4757 stack pointer, deleting the modifications and changing the
4758 references to point to the location the stack pointer would have
4759 pointed to had the modifications taken place.
4761 These functions need to be portable so we need to make as few
4762 assumptions about the epilogue as we can. However, the epilogue
4763 basically contains three things: instructions to reset the stack
4764 pointer, instructions to reload registers, possibly including the
4765 frame pointer, and an instruction to return to the caller.
4767 We must be sure of what a relevant epilogue insn is doing. We also
4768 make no attempt to validate the insns we make since if they are
4769 invalid, we probably can't do anything valid. The intent is that
4770 these routines get "smarter" as more and more machines start to use
4771 them and they try operating on different epilogues.
4773 We use the following structure to track what the part of the
4774 epilogue that we've already processed has done. We keep two copies
4775 of the SP equivalence, one for use during the insn we are
4776 processing and one for use in the next insn. The difference is
4777 because one part of a PARALLEL may adjust SP and the other may use
4782 rtx sp_equiv_reg; /* REG that SP is set from, perhaps SP. */
4783 HOST_WIDE_INT sp_offset; /* Offset from SP_EQUIV_REG of present SP. */
4784 rtx new_sp_equiv_reg; /* REG to be used at end of insn. */
4785 HOST_WIDE_INT new_sp_offset; /* Offset to be used at end of insn. */
4786 rtx equiv_reg_src; /* If nonzero, the value that SP_EQUIV_REG
4787 should be set to once we no longer need
4789 rtx const_equiv[FIRST_PSEUDO_REGISTER]; /* Any known constant equivalences
4793 static void handle_epilogue_set (rtx, struct epi_info *);
4794 static void update_epilogue_consts (rtx, const_rtx, void *);
4795 static void emit_equiv_load (struct epi_info *);
4797 /* Modify INSN, a list of one or more insns that is part of the epilogue, to
4798 no modifications to the stack pointer. Return the new list of insns. */
4801 keep_stack_depressed (rtx insns)
4804 struct epi_info info;
4807 /* If the epilogue is just a single instruction, it must be OK as is. */
4808 if (NEXT_INSN (insns) == NULL_RTX)
4811 /* Otherwise, start a sequence, initialize the information we have, and
4812 process all the insns we were given. */
4815 info.sp_equiv_reg = stack_pointer_rtx;
4817 info.equiv_reg_src = 0;
4819 for (j = 0; j < FIRST_PSEUDO_REGISTER; j++)
4820 info.const_equiv[j] = 0;
4824 while (insn != NULL_RTX)
4826 next = NEXT_INSN (insn);
4835 /* If this insn references the register that SP is equivalent to and
4836 we have a pending load to that register, we must force out the load
4837 first and then indicate we no longer know what SP's equivalent is. */
4838 if (info.equiv_reg_src != 0
4839 && reg_referenced_p (info.sp_equiv_reg, PATTERN (insn)))
4841 emit_equiv_load (&info);
4842 info.sp_equiv_reg = 0;
4845 info.new_sp_equiv_reg = info.sp_equiv_reg;
4846 info.new_sp_offset = info.sp_offset;
4848 /* If this is a (RETURN) and the return address is on the stack,
4849 update the address and change to an indirect jump. */
4850 if (GET_CODE (PATTERN (insn)) == RETURN
4851 || (GET_CODE (PATTERN (insn)) == PARALLEL
4852 && GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == RETURN))
4854 rtx retaddr = INCOMING_RETURN_ADDR_RTX;
4856 HOST_WIDE_INT offset = 0;
4857 rtx jump_insn, jump_set;
4859 /* If the return address is in a register, we can emit the insn
4860 unchanged. Otherwise, it must be a MEM and we see what the
4861 base register and offset are. In any case, we have to emit any
4862 pending load to the equivalent reg of SP, if any. */
4863 if (REG_P (retaddr))
4865 emit_equiv_load (&info);
4873 gcc_assert (MEM_P (retaddr));
4875 ret_ptr = XEXP (retaddr, 0);
4877 if (REG_P (ret_ptr))
4879 base = gen_rtx_REG (Pmode, REGNO (ret_ptr));
4884 gcc_assert (GET_CODE (ret_ptr) == PLUS
4885 && REG_P (XEXP (ret_ptr, 0))
4886 && GET_CODE (XEXP (ret_ptr, 1)) == CONST_INT);
4887 base = gen_rtx_REG (Pmode, REGNO (XEXP (ret_ptr, 0)));
4888 offset = INTVAL (XEXP (ret_ptr, 1));
4892 /* If the base of the location containing the return pointer
4893 is SP, we must update it with the replacement address. Otherwise,
4894 just build the necessary MEM. */
4895 retaddr = plus_constant (base, offset);
4896 if (base == stack_pointer_rtx)
4897 retaddr = simplify_replace_rtx (retaddr, stack_pointer_rtx,
4898 plus_constant (info.sp_equiv_reg,
4901 retaddr = gen_rtx_MEM (Pmode, retaddr);
4902 MEM_NOTRAP_P (retaddr) = 1;
4904 /* If there is a pending load to the equivalent register for SP
4905 and we reference that register, we must load our address into
4906 a scratch register and then do that load. */
4907 if (info.equiv_reg_src
4908 && reg_overlap_mentioned_p (info.equiv_reg_src, retaddr))
4913 for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
4914 if (HARD_REGNO_MODE_OK (regno, Pmode)
4915 && !fixed_regs[regno]
4916 && TEST_HARD_REG_BIT (regs_invalidated_by_call, regno)
4918 (DF_LR_IN (EXIT_BLOCK_PTR), regno)
4919 && !refers_to_regno_p (regno,
4920 end_hard_regno (Pmode, regno),
4921 info.equiv_reg_src, NULL)
4922 && info.const_equiv[regno] == 0)
4925 gcc_assert (regno < FIRST_PSEUDO_REGISTER);
4927 reg = gen_rtx_REG (Pmode, regno);
4928 emit_move_insn (reg, retaddr);
4932 emit_equiv_load (&info);
4933 jump_insn = emit_jump_insn (gen_indirect_jump (retaddr));
4935 /* Show the SET in the above insn is a RETURN. */
4936 jump_set = single_set (jump_insn);
4937 gcc_assert (jump_set);
4938 SET_IS_RETURN_P (jump_set) = 1;
4941 /* If SP is not mentioned in the pattern and its equivalent register, if
4942 any, is not modified, just emit it. Otherwise, if neither is set,
4943 replace the reference to SP and emit the insn. If none of those are
4944 true, handle each SET individually. */
4945 else if (!reg_mentioned_p (stack_pointer_rtx, PATTERN (insn))
4946 && (info.sp_equiv_reg == stack_pointer_rtx
4947 || !reg_set_p (info.sp_equiv_reg, insn)))
4949 else if (! reg_set_p (stack_pointer_rtx, insn)
4950 && (info.sp_equiv_reg == stack_pointer_rtx
4951 || !reg_set_p (info.sp_equiv_reg, insn)))
4955 changed = validate_replace_rtx (stack_pointer_rtx,
4956 plus_constant (info.sp_equiv_reg,
4959 gcc_assert (changed);
4963 else if (GET_CODE (PATTERN (insn)) == SET)
4964 handle_epilogue_set (PATTERN (insn), &info);
4965 else if (GET_CODE (PATTERN (insn)) == PARALLEL)
4967 for (j = 0; j < XVECLEN (PATTERN (insn), 0); j++)
4968 if (GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == SET)
4969 handle_epilogue_set (XVECEXP (PATTERN (insn), 0, j), &info);
4974 info.sp_equiv_reg = info.new_sp_equiv_reg;
4975 info.sp_offset = info.new_sp_offset;
4977 /* Now update any constants this insn sets. */
4978 note_stores (PATTERN (insn), update_epilogue_consts, &info);
4982 insns = get_insns ();
4987 /* SET is a SET from an insn in the epilogue. P is a pointer to the epi_info
4988 structure that contains information about what we've seen so far. We
4989 process this SET by either updating that data or by emitting one or
4993 handle_epilogue_set (rtx set, struct epi_info *p)
4995 /* First handle the case where we are setting SP. Record what it is being
4996 set from, which we must be able to determine */
4997 if (reg_set_p (stack_pointer_rtx, set))
4999 gcc_assert (SET_DEST (set) == stack_pointer_rtx);
5001 if (GET_CODE (SET_SRC (set)) == PLUS)
5003 p->new_sp_equiv_reg = XEXP (SET_SRC (set), 0);
5004 if (GET_CODE (XEXP (SET_SRC (set), 1)) == CONST_INT)
5005 p->new_sp_offset = INTVAL (XEXP (SET_SRC (set), 1));
5008 gcc_assert (REG_P (XEXP (SET_SRC (set), 1))
5009 && (REGNO (XEXP (SET_SRC (set), 1))
5010 < FIRST_PSEUDO_REGISTER)
5011 && p->const_equiv[REGNO (XEXP (SET_SRC (set), 1))]);
5013 = INTVAL (p->const_equiv[REGNO (XEXP (SET_SRC (set), 1))]);
5017 p->new_sp_equiv_reg = SET_SRC (set), p->new_sp_offset = 0;
5019 /* If we are adjusting SP, we adjust from the old data. */
5020 if (p->new_sp_equiv_reg == stack_pointer_rtx)
5022 p->new_sp_equiv_reg = p->sp_equiv_reg;
5023 p->new_sp_offset += p->sp_offset;
5026 gcc_assert (p->new_sp_equiv_reg && REG_P (p->new_sp_equiv_reg));
5031 /* Next handle the case where we are setting SP's equivalent
5032 register. We must not already have a value to set it to. We
5033 could update, but there seems little point in handling that case.
5034 Note that we have to allow for the case where we are setting the
5035 register set in the previous part of a PARALLEL inside a single
5036 insn. But use the old offset for any updates within this insn.
5037 We must allow for the case where the register is being set in a
5038 different (usually wider) mode than Pmode). */
5039 else if (p->new_sp_equiv_reg != 0 && reg_set_p (p->new_sp_equiv_reg, set))
5041 gcc_assert (!p->equiv_reg_src
5042 && REG_P (p->new_sp_equiv_reg)
5043 && REG_P (SET_DEST (set))
5044 && (GET_MODE_BITSIZE (GET_MODE (SET_DEST (set)))
5046 && REGNO (p->new_sp_equiv_reg) == REGNO (SET_DEST (set)));
5048 = simplify_replace_rtx (SET_SRC (set), stack_pointer_rtx,
5049 plus_constant (p->sp_equiv_reg,
5053 /* Otherwise, replace any references to SP in the insn to its new value
5054 and emit the insn. */
5057 SET_SRC (set) = simplify_replace_rtx (SET_SRC (set), stack_pointer_rtx,
5058 plus_constant (p->sp_equiv_reg,
5060 SET_DEST (set) = simplify_replace_rtx (SET_DEST (set), stack_pointer_rtx,
5061 plus_constant (p->sp_equiv_reg,
5067 /* Update the tracking information for registers set to constants. */
5070 update_epilogue_consts (rtx dest, const_rtx x, void *data)
5072 struct epi_info *p = (struct epi_info *) data;
5075 if (!REG_P (dest) || REGNO (dest) >= FIRST_PSEUDO_REGISTER)
5078 /* If we are either clobbering a register or doing a partial set,
5079 show we don't know the value. */
5080 else if (GET_CODE (x) == CLOBBER || ! rtx_equal_p (dest, SET_DEST (x)))
5081 p->const_equiv[REGNO (dest)] = 0;
5083 /* If we are setting it to a constant, record that constant. */
5084 else if (GET_CODE (SET_SRC (x)) == CONST_INT)
5085 p->const_equiv[REGNO (dest)] = SET_SRC (x);
5087 /* If this is a binary operation between a register we have been tracking
5088 and a constant, see if we can compute a new constant value. */
5089 else if (ARITHMETIC_P (SET_SRC (x))
5090 && REG_P (XEXP (SET_SRC (x), 0))
5091 && REGNO (XEXP (SET_SRC (x), 0)) < FIRST_PSEUDO_REGISTER
5092 && p->const_equiv[REGNO (XEXP (SET_SRC (x), 0))] != 0
5093 && GET_CODE (XEXP (SET_SRC (x), 1)) == CONST_INT
5094 && 0 != (new = simplify_binary_operation
5095 (GET_CODE (SET_SRC (x)), GET_MODE (dest),
5096 p->const_equiv[REGNO (XEXP (SET_SRC (x), 0))],
5097 XEXP (SET_SRC (x), 1)))
5098 && GET_CODE (new) == CONST_INT)
5099 p->const_equiv[REGNO (dest)] = new;
5101 /* Otherwise, we can't do anything with this value. */
5103 p->const_equiv[REGNO (dest)] = 0;
5106 /* Emit an insn to do the load shown in p->equiv_reg_src, if needed. */
5109 emit_equiv_load (struct epi_info *p)
5111 if (p->equiv_reg_src != 0)
5113 rtx dest = p->sp_equiv_reg;
5115 if (GET_MODE (p->equiv_reg_src) != GET_MODE (dest))
5116 dest = gen_rtx_REG (GET_MODE (p->equiv_reg_src),
5117 REGNO (p->sp_equiv_reg));
5119 emit_move_insn (dest, p->equiv_reg_src);
5120 p->equiv_reg_src = 0;
5125 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
5126 this into place with notes indicating where the prologue ends and where
5127 the epilogue begins. Update the basic block information when possible. */
5130 thread_prologue_and_epilogue_insns (void)
5134 #if defined (HAVE_sibcall_epilogue) || defined (HAVE_epilogue) || defined (HAVE_return) || defined (HAVE_prologue)
5137 #if defined (HAVE_epilogue) || defined(HAVE_return)
5138 rtx epilogue_end = NULL_RTX;
5142 #ifdef HAVE_prologue
5146 seq = gen_prologue ();
5149 /* Insert an explicit USE for the frame pointer
5150 if the profiling is on and the frame pointer is required. */
5151 if (current_function_profile && frame_pointer_needed)
5152 emit_insn (gen_rtx_USE (VOIDmode, hard_frame_pointer_rtx));
5154 /* Retain a map of the prologue insns. */
5155 record_insns (seq, &prologue);
5156 emit_note (NOTE_INSN_PROLOGUE_END);
5158 #ifndef PROFILE_BEFORE_PROLOGUE
5159 /* Ensure that instructions are not moved into the prologue when
5160 profiling is on. The call to the profiling routine can be
5161 emitted within the live range of a call-clobbered register. */
5162 if (current_function_profile)
5163 emit_insn (gen_blockage ());
5168 set_insn_locators (seq, prologue_locator);
5170 /* Can't deal with multiple successors of the entry block
5171 at the moment. Function should always have at least one
5173 gcc_assert (single_succ_p (ENTRY_BLOCK_PTR));
5175 insert_insn_on_edge (seq, single_succ_edge (ENTRY_BLOCK_PTR));
5180 /* If the exit block has no non-fake predecessors, we don't need
5182 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5183 if ((e->flags & EDGE_FAKE) == 0)
5189 if (optimize && HAVE_return)
5191 /* If we're allowed to generate a simple return instruction,
5192 then by definition we don't need a full epilogue. Examine
5193 the block that falls through to EXIT. If it does not
5194 contain any code, examine its predecessors and try to
5195 emit (conditional) return instructions. */
5200 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5201 if (e->flags & EDGE_FALLTHRU)
5207 /* Verify that there are no active instructions in the last block. */
5208 label = BB_END (last);
5209 while (label && !LABEL_P (label))
5211 if (active_insn_p (label))
5213 label = PREV_INSN (label);
5216 if (BB_HEAD (last) == label && LABEL_P (label))
5220 for (ei2 = ei_start (last->preds); (e = ei_safe_edge (ei2)); )
5222 basic_block bb = e->src;
5225 if (bb == ENTRY_BLOCK_PTR)
5232 if (!JUMP_P (jump) || JUMP_LABEL (jump) != label)
5238 /* If we have an unconditional jump, we can replace that
5239 with a simple return instruction. */
5240 if (simplejump_p (jump))
5242 emit_return_into_block (bb);
5246 /* If we have a conditional jump, we can try to replace
5247 that with a conditional return instruction. */
5248 else if (condjump_p (jump))
5250 if (! redirect_jump (jump, 0, 0))
5256 /* If this block has only one successor, it both jumps
5257 and falls through to the fallthru block, so we can't
5259 if (single_succ_p (bb))
5271 /* Fix up the CFG for the successful change we just made. */
5272 redirect_edge_succ (e, EXIT_BLOCK_PTR);
5275 /* Emit a return insn for the exit fallthru block. Whether
5276 this is still reachable will be determined later. */
5278 emit_barrier_after (BB_END (last));
5279 emit_return_into_block (last);
5280 epilogue_end = BB_END (last);
5281 single_succ_edge (last)->flags &= ~EDGE_FALLTHRU;
5286 /* Find the edge that falls through to EXIT. Other edges may exist
5287 due to RETURN instructions, but those don't need epilogues.
5288 There really shouldn't be a mixture -- either all should have
5289 been converted or none, however... */
5291 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5292 if (e->flags & EDGE_FALLTHRU)
5297 #ifdef HAVE_epilogue
5301 epilogue_end = emit_note (NOTE_INSN_EPILOGUE_BEG);
5303 seq = gen_epilogue ();
5305 #ifdef INCOMING_RETURN_ADDR_RTX
5306 /* If this function returns with the stack depressed and we can support
5307 it, massage the epilogue to actually do that. */
5308 if (TREE_CODE (TREE_TYPE (current_function_decl)) == FUNCTION_TYPE
5309 && TYPE_RETURNS_STACK_DEPRESSED (TREE_TYPE (current_function_decl)))
5310 seq = keep_stack_depressed (seq);
5313 emit_jump_insn (seq);
5315 /* Retain a map of the epilogue insns. */
5316 record_insns (seq, &epilogue);
5317 set_insn_locators (seq, epilogue_locator);
5322 insert_insn_on_edge (seq, e);
5330 if (! next_active_insn (BB_END (e->src)))
5332 /* We have a fall-through edge to the exit block, the source is not
5333 at the end of the function, and there will be an assembler epilogue
5334 at the end of the function.
5335 We can't use force_nonfallthru here, because that would try to
5336 use return. Inserting a jump 'by hand' is extremely messy, so
5337 we take advantage of cfg_layout_finalize using
5338 fixup_fallthru_exit_predecessor. */
5339 cfg_layout_initialize (0);
5340 FOR_EACH_BB (cur_bb)
5341 if (cur_bb->index >= NUM_FIXED_BLOCKS
5342 && cur_bb->next_bb->index >= NUM_FIXED_BLOCKS)
5343 cur_bb->aux = cur_bb->next_bb;
5344 cfg_layout_finalize ();
5350 commit_edge_insertions ();
5352 /* The epilogue insns we inserted may cause the exit edge to no longer
5354 FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds)
5356 if (((e->flags & EDGE_FALLTHRU) != 0)
5357 && returnjump_p (BB_END (e->src)))
5358 e->flags &= ~EDGE_FALLTHRU;
5362 #ifdef HAVE_sibcall_epilogue
5363 /* Emit sibling epilogues before any sibling call sites. */
5364 for (ei = ei_start (EXIT_BLOCK_PTR->preds); (e = ei_safe_edge (ei)); )
5366 basic_block bb = e->src;
5367 rtx insn = BB_END (bb);
5370 || ! SIBLING_CALL_P (insn))
5377 emit_insn (gen_sibcall_epilogue ());
5381 /* Retain a map of the epilogue insns. Used in life analysis to
5382 avoid getting rid of sibcall epilogue insns. Do this before we
5383 actually emit the sequence. */
5384 record_insns (seq, &sibcall_epilogue);
5385 set_insn_locators (seq, epilogue_locator);
5387 emit_insn_before (seq, insn);
5392 #ifdef HAVE_epilogue
5397 /* Similarly, move any line notes that appear after the epilogue.
5398 There is no need, however, to be quite so anal about the existence
5399 of such a note. Also possibly move
5400 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
5402 for (insn = epilogue_end; insn; insn = next)
5404 next = NEXT_INSN (insn);
5406 && (NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG))
5407 reorder_insns (insn, insn, PREV_INSN (epilogue_end));
5412 /* Threading the prologue and epilogue changes the artificial refs
5413 in the entry and exit blocks. */
5414 epilogue_completed = 1;
5415 df_update_entry_exit_and_calls ();
5418 /* Reposition the prologue-end and epilogue-begin notes after instruction
5419 scheduling and delayed branch scheduling. */
5422 reposition_prologue_and_epilogue_notes (void)
5424 #if defined (HAVE_prologue) || defined (HAVE_epilogue)
5425 rtx insn, last, note;
5428 if ((len = VEC_length (int, prologue)) > 0)
5432 /* Scan from the beginning until we reach the last prologue insn.
5433 We apparently can't depend on basic_block_{head,end} after
5435 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
5439 if (NOTE_KIND (insn) == NOTE_INSN_PROLOGUE_END)
5442 else if (contains (insn, &prologue))
5452 /* Find the prologue-end note if we haven't already, and
5453 move it to just after the last prologue insn. */
5456 for (note = last; (note = NEXT_INSN (note));)
5458 && NOTE_KIND (note) == NOTE_INSN_PROLOGUE_END)
5462 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
5464 last = NEXT_INSN (last);
5465 reorder_insns (note, note, last);
5469 if ((len = VEC_length (int, epilogue)) > 0)
5473 /* Scan from the end until we reach the first epilogue insn.
5474 We apparently can't depend on basic_block_{head,end} after
5476 for (insn = get_last_insn (); insn; insn = PREV_INSN (insn))
5480 if (NOTE_KIND (insn) == NOTE_INSN_EPILOGUE_BEG)
5483 else if (contains (insn, &epilogue))
5493 /* Find the epilogue-begin note if we haven't already, and
5494 move it to just before the first epilogue insn. */
5497 for (note = insn; (note = PREV_INSN (note));)
5499 && NOTE_KIND (note) == NOTE_INSN_EPILOGUE_BEG)
5503 if (PREV_INSN (last) != note)
5504 reorder_insns (note, note, PREV_INSN (last));
5507 #endif /* HAVE_prologue or HAVE_epilogue */
5510 /* Returns the name of the current function. */
5512 current_function_name (void)
5514 return lang_hooks.decl_printable_name (cfun->decl, 2);
5517 /* Returns the raw (mangled) name of the current function. */
5519 current_function_assembler_name (void)
5521 return IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (cfun->decl));
5526 rest_of_handle_check_leaf_regs (void)
5528 #ifdef LEAF_REGISTERS
5529 current_function_uses_only_leaf_regs
5530 = optimize > 0 && only_leaf_regs_used () && leaf_function_p ();
5535 /* Insert a TYPE into the used types hash table of CFUN. */
5537 used_types_insert_helper (tree type, struct function *func)
5539 if (type != NULL && func != NULL)
5543 if (func->used_types_hash == NULL)
5544 func->used_types_hash = htab_create_ggc (37, htab_hash_pointer,
5545 htab_eq_pointer, NULL);
5546 slot = htab_find_slot (func->used_types_hash, type, INSERT);
5552 /* Given a type, insert it into the used hash table in cfun. */
5554 used_types_insert (tree t)
5556 while (POINTER_TYPE_P (t) || TREE_CODE (t) == ARRAY_TYPE)
5558 t = TYPE_MAIN_VARIANT (t);
5559 if (debug_info_level > DINFO_LEVEL_NONE)
5560 used_types_insert_helper (t, cfun);
5563 struct rtl_opt_pass pass_leaf_regs =
5569 rest_of_handle_check_leaf_regs, /* execute */
5572 0, /* static_pass_number */
5574 0, /* properties_required */
5575 0, /* properties_provided */
5576 0, /* properties_destroyed */
5577 0, /* todo_flags_start */
5578 0 /* todo_flags_finish */
5583 rest_of_handle_thread_prologue_and_epilogue (void)
5586 cleanup_cfg (CLEANUP_EXPENSIVE);
5587 /* On some machines, the prologue and epilogue code, or parts thereof,
5588 can be represented as RTL. Doing so lets us schedule insns between
5589 it and the rest of the code and also allows delayed branch
5590 scheduling to operate in the epilogue. */
5592 thread_prologue_and_epilogue_insns ();
5596 struct rtl_opt_pass pass_thread_prologue_and_epilogue =
5600 "pro_and_epilogue", /* name */
5602 rest_of_handle_thread_prologue_and_epilogue, /* execute */
5605 0, /* static_pass_number */
5606 TV_THREAD_PROLOGUE_AND_EPILOGUE, /* tv_id */
5607 0, /* properties_required */
5608 0, /* properties_provided */
5609 0, /* properties_destroyed */
5610 TODO_verify_flow, /* todo_flags_start */
5613 TODO_df_finish | TODO_verify_rtl_sharing |
5614 TODO_ggc_collect /* todo_flags_finish */
5619 /* This mini-pass fixes fall-out from SSA in asm statements that have
5620 in-out constraints. Say you start with
5623 asm ("": "+mr" (inout));
5626 which is transformed very early to use explicit output and match operands:
5629 asm ("": "=mr" (inout) : "0" (inout));
5632 Or, after SSA and copyprop,
5634 asm ("": "=mr" (inout_2) : "0" (inout_1));
5637 Clearly inout_2 and inout_1 can't be coalesced easily anymore, as
5638 they represent two separate values, so they will get different pseudo
5639 registers during expansion. Then, since the two operands need to match
5640 per the constraints, but use different pseudo registers, reload can
5641 only register a reload for these operands. But reloads can only be
5642 satisfied by hardregs, not by memory, so we need a register for this
5643 reload, just because we are presented with non-matching operands.
5644 So, even though we allow memory for this operand, no memory can be
5645 used for it, just because the two operands don't match. This can
5646 cause reload failures on register-starved targets.
5648 So it's a symptom of reload not being able to use memory for reloads
5649 or, alternatively it's also a symptom of both operands not coming into
5650 reload as matching (in which case the pseudo could go to memory just
5651 fine, as the alternative allows it, and no reload would be necessary).
5652 We fix the latter problem here, by transforming
5654 asm ("": "=mr" (inout_2) : "0" (inout_1));
5659 asm ("": "=mr" (inout_2) : "0" (inout_2)); */
5662 match_asm_constraints_1 (rtx insn, rtx *p_sets, int noutputs)
5665 bool changed = false;
5666 rtx op = SET_SRC (p_sets[0]);
5667 int ninputs = ASM_OPERANDS_INPUT_LENGTH (op);
5668 rtvec inputs = ASM_OPERANDS_INPUT_VEC (op);
5669 bool *output_matched = alloca (noutputs * sizeof (bool));
5671 memset (output_matched, 0, noutputs * sizeof (bool));
5672 for (i = 0; i < ninputs; i++)
5674 rtx input, output, insns;
5675 const char *constraint = ASM_OPERANDS_INPUT_CONSTRAINT (op, i);
5679 match = strtoul (constraint, &end, 10);
5680 if (end == constraint)
5683 gcc_assert (match < noutputs);
5684 output = SET_DEST (p_sets[match]);
5685 input = RTVEC_ELT (inputs, i);
5686 /* Only do the transformation for pseudos. */
5687 if (! REG_P (output)
5688 || rtx_equal_p (output, input)
5689 || (GET_MODE (input) != VOIDmode
5690 && GET_MODE (input) != GET_MODE (output)))
5693 /* We can't do anything if the output is also used as input,
5694 as we're going to overwrite it. */
5695 for (j = 0; j < ninputs; j++)
5696 if (reg_overlap_mentioned_p (output, RTVEC_ELT (inputs, j)))
5701 /* Avoid changing the same input several times. For
5702 asm ("" : "=mr" (out1), "=mr" (out2) : "0" (in), "1" (in));
5703 only change in once (to out1), rather than changing it
5704 first to out1 and afterwards to out2. */
5707 for (j = 0; j < noutputs; j++)
5708 if (output_matched[j] && input == SET_DEST (p_sets[j]))
5713 output_matched[match] = true;
5716 emit_move_insn (output, input);
5717 insns = get_insns ();
5719 emit_insn_before (insns, insn);
5721 /* Now replace all mentions of the input with output. We can't
5722 just replace the occurence in inputs[i], as the register might
5723 also be used in some other input (or even in an address of an
5724 output), which would mean possibly increasing the number of
5725 inputs by one (namely 'output' in addition), which might pose
5726 a too complicated problem for reload to solve. E.g. this situation:
5728 asm ("" : "=r" (output), "=m" (input) : "0" (input))
5730 Here 'input' is used in two occurrences as input (once for the
5731 input operand, once for the address in the second output operand).
5732 If we would replace only the occurence of the input operand (to
5733 make the matching) we would be left with this:
5736 asm ("" : "=r" (output), "=m" (input) : "0" (output))
5738 Now we suddenly have two different input values (containing the same
5739 value, but different pseudos) where we formerly had only one.
5740 With more complicated asms this might lead to reload failures
5741 which wouldn't have happen without this pass. So, iterate over
5742 all operands and replace all occurrences of the register used. */
5743 for (j = 0; j < noutputs; j++)
5744 if (!rtx_equal_p (SET_DEST (p_sets[j]), input)
5745 && reg_overlap_mentioned_p (input, SET_DEST (p_sets[j])))
5746 SET_DEST (p_sets[j]) = replace_rtx (SET_DEST (p_sets[j]),
5748 for (j = 0; j < ninputs; j++)
5749 if (reg_overlap_mentioned_p (input, RTVEC_ELT (inputs, j)))
5750 RTVEC_ELT (inputs, j) = replace_rtx (RTVEC_ELT (inputs, j),
5757 df_insn_rescan (insn);
5761 rest_of_match_asm_constraints (void)
5764 rtx insn, pat, *p_sets;
5767 if (!cfun->has_asm_statement)
5770 df_set_flags (DF_DEFER_INSN_RESCAN);
5773 FOR_BB_INSNS (bb, insn)
5778 pat = PATTERN (insn);
5779 if (GET_CODE (pat) == PARALLEL)
5780 p_sets = &XVECEXP (pat, 0, 0), noutputs = XVECLEN (pat, 0);
5781 else if (GET_CODE (pat) == SET)
5782 p_sets = &PATTERN (insn), noutputs = 1;
5786 if (GET_CODE (*p_sets) == SET
5787 && GET_CODE (SET_SRC (*p_sets)) == ASM_OPERANDS)
5788 match_asm_constraints_1 (insn, p_sets, noutputs);
5792 return TODO_df_finish;
5795 struct rtl_opt_pass pass_match_asm_constraints =
5799 "asmcons", /* name */
5801 rest_of_match_asm_constraints, /* execute */
5804 0, /* static_pass_number */
5806 0, /* properties_required */
5807 0, /* properties_provided */
5808 0, /* properties_destroyed */
5809 0, /* todo_flags_start */
5810 TODO_dump_func /* todo_flags_finish */
5815 #include "gt-function.h"