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 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
22 /* This file handles the generation of rtl code from tree structure
23 at the level of the function as a whole.
24 It creates the rtl expressions for parameters and auto variables
25 and has full responsibility for allocating stack slots.
27 `expand_function_start' is called at the beginning of a function,
28 before the function body is parsed, and `expand_function_end' is
29 called after parsing the body.
31 Call `assign_stack_local' to allocate a stack slot for a local variable.
32 This is usually done during the RTL generation for the function body,
33 but it can also be done in the reload pass when a pseudo-register does
34 not get a hard register. */
38 #include "coretypes.h"
49 #include "hard-reg-set.h"
50 #include "insn-config.h"
53 #include "basic-block.h"
58 #include "integrate.h"
59 #include "langhooks.h"
61 #include "cfglayout.h"
63 #ifndef LOCAL_ALIGNMENT
64 #define LOCAL_ALIGNMENT(TYPE, ALIGNMENT) ALIGNMENT
67 #ifndef STACK_ALIGNMENT_NEEDED
68 #define STACK_ALIGNMENT_NEEDED 1
71 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
73 /* Some systems use __main in a way incompatible with its use in gcc, in these
74 cases use the macros NAME__MAIN to give a quoted symbol and SYMBOL__MAIN to
75 give the same symbol without quotes for an alternative entry point. You
76 must define both, or neither. */
78 #define NAME__MAIN "__main"
81 /* Round a value to the lowest integer less than it that is a multiple of
82 the required alignment. Avoid using division in case the value is
83 negative. Assume the alignment is a power of two. */
84 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
86 /* Similar, but round to the next highest integer that meets the
88 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
90 /* Nonzero if function being compiled doesn't contain any calls
91 (ignoring the prologue and epilogue). This is set prior to
92 local register allocation and is valid for the remaining
94 int current_function_is_leaf;
96 /* Nonzero if function being compiled doesn't modify the stack pointer
97 (ignoring the prologue and epilogue). This is only valid after
98 life_analysis has run. */
99 int current_function_sp_is_unchanging;
101 /* Nonzero if the function being compiled is a leaf function which only
102 uses leaf registers. This is valid after reload (specifically after
103 sched2) and is useful only if the port defines LEAF_REGISTERS. */
104 int current_function_uses_only_leaf_regs;
106 /* Nonzero once virtual register instantiation has been done.
107 assign_stack_local uses frame_pointer_rtx when this is nonzero.
108 calls.c:emit_library_call_value_1 uses it to set up
109 post-instantiation libcalls. */
110 int virtuals_instantiated;
112 /* Assign unique numbers to labels generated for profiling, debugging, etc. */
113 static GTY(()) int funcdef_no;
115 /* These variables hold pointers to functions to create and destroy
116 target specific, per-function data structures. */
117 struct machine_function * (*init_machine_status) (void);
119 /* The currently compiled function. */
120 struct function *cfun = 0;
122 /* These arrays record the INSN_UIDs of the prologue and epilogue insns. */
123 static GTY(()) varray_type prologue;
124 static GTY(()) varray_type epilogue;
126 /* Array of INSN_UIDs to hold the INSN_UIDs for each sibcall epilogue
128 static GTY(()) varray_type sibcall_epilogue;
130 /* In order to evaluate some expressions, such as function calls returning
131 structures in memory, we need to temporarily allocate stack locations.
132 We record each allocated temporary in the following structure.
134 Associated with each temporary slot is a nesting level. When we pop up
135 one level, all temporaries associated with the previous level are freed.
136 Normally, all temporaries are freed after the execution of the statement
137 in which they were created. However, if we are inside a ({...}) grouping,
138 the result may be in a temporary and hence must be preserved. If the
139 result could be in a temporary, we preserve it if we can determine which
140 one it is in. If we cannot determine which temporary may contain the
141 result, all temporaries are preserved. A temporary is preserved by
142 pretending it was allocated at the previous nesting level.
144 Automatic variables are also assigned temporary slots, at the nesting
145 level where they are defined. They are marked a "kept" so that
146 free_temp_slots will not free them. */
148 struct temp_slot GTY(())
150 /* Points to next temporary slot. */
151 struct temp_slot *next;
152 /* Points to previous temporary slot. */
153 struct temp_slot *prev;
155 /* The rtx to used to reference the slot. */
157 /* The rtx used to represent the address if not the address of the
158 slot above. May be an EXPR_LIST if multiple addresses exist. */
160 /* The alignment (in bits) of the slot. */
162 /* The size, in units, of the slot. */
164 /* The type of the object in the slot, or zero if it doesn't correspond
165 to a type. We use this to determine whether a slot can be reused.
166 It can be reused if objects of the type of the new slot will always
167 conflict with objects of the type of the old slot. */
169 /* Nonzero if this temporary is currently in use. */
171 /* Nonzero if this temporary has its address taken. */
173 /* Nesting level at which this slot is being used. */
175 /* Nonzero if this should survive a call to free_temp_slots. */
177 /* The offset of the slot from the frame_pointer, including extra space
178 for alignment. This info is for combine_temp_slots. */
179 HOST_WIDE_INT base_offset;
180 /* The size of the slot, including extra space for alignment. This
181 info is for combine_temp_slots. */
182 HOST_WIDE_INT full_size;
185 /* Forward declarations. */
187 static rtx assign_stack_local_1 (enum machine_mode, HOST_WIDE_INT, int,
189 static struct temp_slot *find_temp_slot_from_address (rtx);
190 static void instantiate_decls (tree, int);
191 static void instantiate_decls_1 (tree, int);
192 static void instantiate_decl (rtx, HOST_WIDE_INT, int);
193 static rtx instantiate_new_reg (rtx, HOST_WIDE_INT *);
194 static int instantiate_virtual_regs_1 (rtx *, rtx, int);
195 static void pad_to_arg_alignment (struct args_size *, int, struct args_size *);
196 static void pad_below (struct args_size *, enum machine_mode, tree);
197 static void reorder_blocks_1 (rtx, tree, varray_type *);
198 static void reorder_fix_fragments (tree);
199 static int all_blocks (tree, tree *);
200 static tree *get_block_vector (tree, int *);
201 extern tree debug_find_var_in_block_tree (tree, tree);
202 /* We always define `record_insns' even if it's not used so that we
203 can always export `prologue_epilogue_contains'. */
204 static void record_insns (rtx, varray_type *) ATTRIBUTE_UNUSED;
205 static int contains (rtx, varray_type);
207 static void emit_return_into_block (basic_block, rtx);
209 #if defined(HAVE_epilogue) && defined(INCOMING_RETURN_ADDR_RTX)
210 static rtx keep_stack_depressed (rtx);
212 static void prepare_function_start (tree);
213 static void do_clobber_return_reg (rtx, void *);
214 static void do_use_return_reg (rtx, void *);
215 static void instantiate_virtual_regs_lossage (rtx);
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)
249 if (context == current_function_decl)
250 cfun->contains_functions = 1;
253 struct function *containing = find_function_data (context);
254 containing->contains_functions = 1;
259 init_dummy_function_start ();
262 p->outer = outer_function_chain;
263 outer_function_chain = p;
265 lang_hooks.function.enter_nested (p);
271 push_function_context (void)
273 push_function_context_to (current_function_decl);
276 /* Restore the last saved context, at the end of a nested function.
277 This function is called from language-specific code. */
280 pop_function_context_from (tree context ATTRIBUTE_UNUSED)
282 struct function *p = outer_function_chain;
285 outer_function_chain = p->outer;
287 current_function_decl = p->decl;
290 restore_emit_status (p);
292 lang_hooks.function.leave_nested (p);
294 /* Reset variables that have known state during rtx generation. */
295 virtuals_instantiated = 0;
296 generating_concat_p = 1;
300 pop_function_context (void)
302 pop_function_context_from (current_function_decl);
305 /* Clear out all parts of the state in F that can safely be discarded
306 after the function has been parsed, but not compiled, to let
307 garbage collection reclaim the memory. */
310 free_after_parsing (struct function *f)
312 /* f->expr->forced_labels is used by code generation. */
313 /* f->emit->regno_reg_rtx is used by code generation. */
314 /* f->varasm is used by code generation. */
315 /* f->eh->eh_return_stub_label is used by code generation. */
317 lang_hooks.function.final (f);
320 /* Clear out all parts of the state in F that can safely be discarded
321 after the function has been compiled, to let garbage collection
322 reclaim the memory. */
325 free_after_compilation (struct function *f)
333 f->x_avail_temp_slots = NULL;
334 f->x_used_temp_slots = NULL;
335 f->arg_offset_rtx = NULL;
336 f->return_rtx = NULL;
337 f->internal_arg_pointer = NULL;
338 f->x_nonlocal_goto_handler_labels = NULL;
339 f->x_return_label = NULL;
340 f->x_naked_return_label = NULL;
341 f->x_stack_slot_list = NULL;
342 f->x_tail_recursion_reentry = NULL;
343 f->x_arg_pointer_save_area = NULL;
344 f->x_parm_birth_insn = NULL;
345 f->original_arg_vector = NULL;
346 f->original_decl_initial = NULL;
347 f->epilogue_delay_list = NULL;
350 /* Allocate fixed slots in the stack frame of the current function. */
352 /* Return size needed for stack frame based on slots so far allocated in
354 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
355 the caller may have to do that. */
358 get_func_frame_size (struct function *f)
360 #ifdef FRAME_GROWS_DOWNWARD
361 return -f->x_frame_offset;
363 return f->x_frame_offset;
367 /* Return size needed for stack frame based on slots so far allocated.
368 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
369 the caller may have to do that. */
371 get_frame_size (void)
373 return get_func_frame_size (cfun);
376 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
377 with machine mode MODE.
379 ALIGN controls the amount of alignment for the address of the slot:
380 0 means according to MODE,
381 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
382 -2 means use BITS_PER_UNIT,
383 positive specifies alignment boundary in bits.
385 We do not round to stack_boundary here.
387 FUNCTION specifies the function to allocate in. */
390 assign_stack_local_1 (enum machine_mode mode, HOST_WIDE_INT size, int align,
391 struct function *function)
394 int bigend_correction = 0;
395 unsigned int alignment;
396 int frame_off, frame_alignment, frame_phase;
403 alignment = BIGGEST_ALIGNMENT;
405 alignment = GET_MODE_ALIGNMENT (mode);
407 /* Allow the target to (possibly) increase the alignment of this
409 type = lang_hooks.types.type_for_mode (mode, 0);
411 alignment = LOCAL_ALIGNMENT (type, alignment);
413 alignment /= BITS_PER_UNIT;
415 else if (align == -1)
417 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
418 size = CEIL_ROUND (size, alignment);
420 else if (align == -2)
421 alignment = 1; /* BITS_PER_UNIT / BITS_PER_UNIT */
423 alignment = align / BITS_PER_UNIT;
425 #ifdef FRAME_GROWS_DOWNWARD
426 function->x_frame_offset -= size;
429 /* Ignore alignment we can't do with expected alignment of the boundary. */
430 if (alignment * BITS_PER_UNIT > PREFERRED_STACK_BOUNDARY)
431 alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
433 if (function->stack_alignment_needed < alignment * BITS_PER_UNIT)
434 function->stack_alignment_needed = alignment * BITS_PER_UNIT;
436 /* Calculate how many bytes the start of local variables is off from
438 frame_alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
439 frame_off = STARTING_FRAME_OFFSET % frame_alignment;
440 frame_phase = frame_off ? frame_alignment - frame_off : 0;
442 /* Round the frame offset to the specified alignment. The default is
443 to always honor requests to align the stack but a port may choose to
444 do its own stack alignment by defining STACK_ALIGNMENT_NEEDED. */
445 if (STACK_ALIGNMENT_NEEDED
449 /* We must be careful here, since FRAME_OFFSET might be negative and
450 division with a negative dividend isn't as well defined as we might
451 like. So we instead assume that ALIGNMENT is a power of two and
452 use logical operations which are unambiguous. */
453 #ifdef FRAME_GROWS_DOWNWARD
454 function->x_frame_offset
455 = (FLOOR_ROUND (function->x_frame_offset - frame_phase,
456 (unsigned HOST_WIDE_INT) alignment)
459 function->x_frame_offset
460 = (CEIL_ROUND (function->x_frame_offset - frame_phase,
461 (unsigned HOST_WIDE_INT) alignment)
466 /* On a big-endian machine, if we are allocating more space than we will use,
467 use the least significant bytes of those that are allocated. */
468 if (BYTES_BIG_ENDIAN && mode != BLKmode)
469 bigend_correction = size - GET_MODE_SIZE (mode);
471 /* If we have already instantiated virtual registers, return the actual
472 address relative to the frame pointer. */
473 if (function == cfun && virtuals_instantiated)
474 addr = plus_constant (frame_pointer_rtx,
476 (frame_offset + bigend_correction
477 + STARTING_FRAME_OFFSET, Pmode));
479 addr = plus_constant (virtual_stack_vars_rtx,
481 (function->x_frame_offset + bigend_correction,
484 #ifndef FRAME_GROWS_DOWNWARD
485 function->x_frame_offset += size;
488 x = gen_rtx_MEM (mode, addr);
490 function->x_stack_slot_list
491 = gen_rtx_EXPR_LIST (VOIDmode, x, function->x_stack_slot_list);
496 /* Wrapper around assign_stack_local_1; assign a local stack slot for the
500 assign_stack_local (enum machine_mode mode, HOST_WIDE_INT size, int align)
502 return assign_stack_local_1 (mode, size, align, cfun);
506 /* Removes temporary slot TEMP from LIST. */
509 cut_slot_from_list (struct temp_slot *temp, struct temp_slot **list)
512 temp->next->prev = temp->prev;
514 temp->prev->next = temp->next;
518 temp->prev = temp->next = NULL;
521 /* Inserts temporary slot TEMP to LIST. */
524 insert_slot_to_list (struct temp_slot *temp, struct temp_slot **list)
528 (*list)->prev = temp;
533 /* Returns the list of used temp slots at LEVEL. */
535 static struct temp_slot **
536 temp_slots_at_level (int level)
540 if (!used_temp_slots)
541 VARRAY_GENERIC_PTR_INIT (used_temp_slots, 3, "used_temp_slots");
543 while (level >= (int) VARRAY_ACTIVE_SIZE (used_temp_slots))
544 VARRAY_PUSH_GENERIC_PTR (used_temp_slots, NULL);
546 return (struct temp_slot **) &VARRAY_GENERIC_PTR (used_temp_slots, level);
549 /* Returns the maximal temporary slot level. */
552 max_slot_level (void)
554 if (!used_temp_slots)
557 return VARRAY_ACTIVE_SIZE (used_temp_slots) - 1;
560 /* Moves temporary slot TEMP to LEVEL. */
563 move_slot_to_level (struct temp_slot *temp, int level)
565 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
566 insert_slot_to_list (temp, temp_slots_at_level (level));
570 /* Make temporary slot TEMP available. */
573 make_slot_available (struct temp_slot *temp)
575 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
576 insert_slot_to_list (temp, &avail_temp_slots);
581 /* Allocate a temporary stack slot and record it for possible later
584 MODE is the machine mode to be given to the returned rtx.
586 SIZE is the size in units of the space required. We do no rounding here
587 since assign_stack_local will do any required rounding.
589 KEEP is 1 if this slot is to be retained after a call to
590 free_temp_slots. Automatic variables for a block are allocated
591 with this flag. KEEP values of 2 or 3 were needed respectively
592 for variables whose lifetime is controlled by CLEANUP_POINT_EXPRs
593 or for SAVE_EXPRs, but they are now unused and will abort.
595 TYPE is the type that will be used for the stack slot. */
598 assign_stack_temp_for_type (enum machine_mode mode, HOST_WIDE_INT size, int keep,
602 struct temp_slot *p, *best_p = 0, *selected = NULL, **pp;
605 /* If SIZE is -1 it means that somebody tried to allocate a temporary
606 of a variable size. */
610 /* These are now unused. */
615 align = BIGGEST_ALIGNMENT;
617 align = GET_MODE_ALIGNMENT (mode);
620 type = lang_hooks.types.type_for_mode (mode, 0);
623 align = LOCAL_ALIGNMENT (type, align);
625 /* Try to find an available, already-allocated temporary of the proper
626 mode which meets the size and alignment requirements. Choose the
627 smallest one with the closest alignment. */
628 for (p = avail_temp_slots; p; p = p->next)
630 if (p->align >= align && p->size >= size && GET_MODE (p->slot) == mode
631 && objects_must_conflict_p (p->type, type)
632 && (best_p == 0 || best_p->size > p->size
633 || (best_p->size == p->size && best_p->align > p->align)))
635 if (p->align == align && p->size == size)
638 cut_slot_from_list (selected, &avail_temp_slots);
646 /* Make our best, if any, the one to use. */
650 cut_slot_from_list (selected, &avail_temp_slots);
652 /* If there are enough aligned bytes left over, make them into a new
653 temp_slot so that the extra bytes don't get wasted. Do this only
654 for BLKmode slots, so that we can be sure of the alignment. */
655 if (GET_MODE (best_p->slot) == BLKmode)
657 int alignment = best_p->align / BITS_PER_UNIT;
658 HOST_WIDE_INT rounded_size = CEIL_ROUND (size, alignment);
660 if (best_p->size - rounded_size >= alignment)
662 p = ggc_alloc (sizeof (struct temp_slot));
663 p->in_use = p->addr_taken = 0;
664 p->size = best_p->size - rounded_size;
665 p->base_offset = best_p->base_offset + rounded_size;
666 p->full_size = best_p->full_size - rounded_size;
667 p->slot = gen_rtx_MEM (BLKmode,
668 plus_constant (XEXP (best_p->slot, 0),
670 p->align = best_p->align;
672 p->type = best_p->type;
673 insert_slot_to_list (p, &avail_temp_slots);
675 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, p->slot,
678 best_p->size = rounded_size;
679 best_p->full_size = rounded_size;
684 /* If we still didn't find one, make a new temporary. */
687 HOST_WIDE_INT frame_offset_old = frame_offset;
689 p = ggc_alloc (sizeof (struct temp_slot));
691 /* We are passing an explicit alignment request to assign_stack_local.
692 One side effect of that is assign_stack_local will not round SIZE
693 to ensure the frame offset remains suitably aligned.
695 So for requests which depended on the rounding of SIZE, we go ahead
696 and round it now. We also make sure ALIGNMENT is at least
697 BIGGEST_ALIGNMENT. */
698 if (mode == BLKmode && align < BIGGEST_ALIGNMENT)
700 p->slot = assign_stack_local (mode,
702 ? CEIL_ROUND (size, (int) align / BITS_PER_UNIT)
708 /* The following slot size computation is necessary because we don't
709 know the actual size of the temporary slot until assign_stack_local
710 has performed all the frame alignment and size rounding for the
711 requested temporary. Note that extra space added for alignment
712 can be either above or below this stack slot depending on which
713 way the frame grows. We include the extra space if and only if it
714 is above this slot. */
715 #ifdef FRAME_GROWS_DOWNWARD
716 p->size = frame_offset_old - frame_offset;
721 /* Now define the fields used by combine_temp_slots. */
722 #ifdef FRAME_GROWS_DOWNWARD
723 p->base_offset = frame_offset;
724 p->full_size = frame_offset_old - frame_offset;
726 p->base_offset = frame_offset_old;
727 p->full_size = frame_offset - frame_offset_old;
738 p->level = temp_slot_level;
741 pp = temp_slots_at_level (p->level);
742 insert_slot_to_list (p, pp);
744 /* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
745 slot = gen_rtx_MEM (mode, XEXP (p->slot, 0));
746 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, slot, stack_slot_list);
748 /* If we know the alias set for the memory that will be used, use
749 it. If there's no TYPE, then we don't know anything about the
750 alias set for the memory. */
751 set_mem_alias_set (slot, type ? get_alias_set (type) : 0);
752 set_mem_align (slot, align);
754 /* If a type is specified, set the relevant flags. */
757 RTX_UNCHANGING_P (slot) = (lang_hooks.honor_readonly
758 && TYPE_READONLY (type));
759 MEM_VOLATILE_P (slot) = TYPE_VOLATILE (type);
760 MEM_SET_IN_STRUCT_P (slot, AGGREGATE_TYPE_P (type));
766 /* Allocate a temporary stack slot and record it for possible later
767 reuse. First three arguments are same as in preceding function. */
770 assign_stack_temp (enum machine_mode mode, HOST_WIDE_INT size, int keep)
772 return assign_stack_temp_for_type (mode, size, keep, NULL_TREE);
775 /* Assign a temporary.
776 If TYPE_OR_DECL is a decl, then we are doing it on behalf of the decl
777 and so that should be used in error messages. In either case, we
778 allocate of the given type.
779 KEEP is as for assign_stack_temp.
780 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
781 it is 0 if a register is OK.
782 DONT_PROMOTE is 1 if we should not promote values in register
786 assign_temp (tree type_or_decl, int keep, int memory_required,
787 int dont_promote ATTRIBUTE_UNUSED)
790 enum machine_mode mode;
795 if (DECL_P (type_or_decl))
796 decl = type_or_decl, type = TREE_TYPE (decl);
798 decl = NULL, type = type_or_decl;
800 mode = TYPE_MODE (type);
802 unsignedp = TYPE_UNSIGNED (type);
805 if (mode == BLKmode || memory_required)
807 HOST_WIDE_INT size = int_size_in_bytes (type);
811 /* Zero sized arrays are GNU C extension. Set size to 1 to avoid
812 problems with allocating the stack space. */
816 /* Unfortunately, we don't yet know how to allocate variable-sized
817 temporaries. However, sometimes we have a fixed upper limit on
818 the size (which is stored in TYPE_ARRAY_MAX_SIZE) and can use that
819 instead. This is the case for Chill variable-sized strings. */
820 if (size == -1 && TREE_CODE (type) == ARRAY_TYPE
821 && TYPE_ARRAY_MAX_SIZE (type) != NULL_TREE
822 && host_integerp (TYPE_ARRAY_MAX_SIZE (type), 1))
823 size = tree_low_cst (TYPE_ARRAY_MAX_SIZE (type), 1);
825 /* If we still haven't been able to get a size, see if the language
826 can compute a maximum size. */
828 && (size_tree = lang_hooks.types.max_size (type)) != 0
829 && host_integerp (size_tree, 1))
830 size = tree_low_cst (size_tree, 1);
832 /* The size of the temporary may be too large to fit into an integer. */
833 /* ??? Not sure this should happen except for user silliness, so limit
834 this to things that aren't compiler-generated temporaries. The
835 rest of the time we'll abort in assign_stack_temp_for_type. */
836 if (decl && size == -1
837 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST)
839 error ("%Jsize of variable '%D' is too large", decl, decl);
843 tmp = assign_stack_temp_for_type (mode, size, keep, type);
849 mode = promote_mode (type, mode, &unsignedp, 0);
852 return gen_reg_rtx (mode);
855 /* Combine temporary stack slots which are adjacent on the stack.
857 This allows for better use of already allocated stack space. This is only
858 done for BLKmode slots because we can be sure that we won't have alignment
859 problems in this case. */
862 combine_temp_slots (void)
864 struct temp_slot *p, *q, *next, *next_q;
867 /* We can't combine slots, because the information about which slot
868 is in which alias set will be lost. */
869 if (flag_strict_aliasing)
872 /* If there are a lot of temp slots, don't do anything unless
873 high levels of optimization. */
874 if (! flag_expensive_optimizations)
875 for (p = avail_temp_slots, num_slots = 0; p; p = p->next, num_slots++)
876 if (num_slots > 100 || (num_slots > 10 && optimize == 0))
879 for (p = avail_temp_slots; p; p = next)
885 if (GET_MODE (p->slot) != BLKmode)
888 for (q = p->next; q; q = next_q)
894 if (GET_MODE (q->slot) != BLKmode)
897 if (p->base_offset + p->full_size == q->base_offset)
899 /* Q comes after P; combine Q into P. */
901 p->full_size += q->full_size;
904 else if (q->base_offset + q->full_size == p->base_offset)
906 /* P comes after Q; combine P into Q. */
908 q->full_size += p->full_size;
913 cut_slot_from_list (q, &avail_temp_slots);
916 /* Either delete P or advance past it. */
918 cut_slot_from_list (p, &avail_temp_slots);
922 /* Find the temp slot corresponding to the object at address X. */
924 static struct temp_slot *
925 find_temp_slot_from_address (rtx x)
931 for (i = max_slot_level (); i >= 0; i--)
932 for (p = *temp_slots_at_level (i); p; p = p->next)
934 if (XEXP (p->slot, 0) == x
936 || (GET_CODE (x) == PLUS
937 && XEXP (x, 0) == virtual_stack_vars_rtx
938 && GET_CODE (XEXP (x, 1)) == CONST_INT
939 && INTVAL (XEXP (x, 1)) >= p->base_offset
940 && INTVAL (XEXP (x, 1)) < p->base_offset + p->full_size))
943 else if (p->address != 0 && GET_CODE (p->address) == EXPR_LIST)
944 for (next = p->address; next; next = XEXP (next, 1))
945 if (XEXP (next, 0) == x)
949 /* If we have a sum involving a register, see if it points to a temp
951 if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 0))
952 && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
954 else if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 1))
955 && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
961 /* Indicate that NEW is an alternate way of referring to the temp slot
962 that previously was known by OLD. */
965 update_temp_slot_address (rtx old, rtx new)
969 if (rtx_equal_p (old, new))
972 p = find_temp_slot_from_address (old);
974 /* If we didn't find one, see if both OLD is a PLUS. If so, and NEW
975 is a register, see if one operand of the PLUS is a temporary
976 location. If so, NEW points into it. Otherwise, if both OLD and
977 NEW are a PLUS and if there is a register in common between them.
978 If so, try a recursive call on those values. */
981 if (GET_CODE (old) != PLUS)
986 update_temp_slot_address (XEXP (old, 0), new);
987 update_temp_slot_address (XEXP (old, 1), new);
990 else if (GET_CODE (new) != PLUS)
993 if (rtx_equal_p (XEXP (old, 0), XEXP (new, 0)))
994 update_temp_slot_address (XEXP (old, 1), XEXP (new, 1));
995 else if (rtx_equal_p (XEXP (old, 1), XEXP (new, 0)))
996 update_temp_slot_address (XEXP (old, 0), XEXP (new, 1));
997 else if (rtx_equal_p (XEXP (old, 0), XEXP (new, 1)))
998 update_temp_slot_address (XEXP (old, 1), XEXP (new, 0));
999 else if (rtx_equal_p (XEXP (old, 1), XEXP (new, 1)))
1000 update_temp_slot_address (XEXP (old, 0), XEXP (new, 0));
1005 /* Otherwise add an alias for the temp's address. */
1006 else if (p->address == 0)
1010 if (GET_CODE (p->address) != EXPR_LIST)
1011 p->address = gen_rtx_EXPR_LIST (VOIDmode, p->address, NULL_RTX);
1013 p->address = gen_rtx_EXPR_LIST (VOIDmode, new, p->address);
1017 /* If X could be a reference to a temporary slot, mark the fact that its
1018 address was taken. */
1021 mark_temp_addr_taken (rtx x)
1023 struct temp_slot *p;
1028 /* If X is not in memory or is at a constant address, it cannot be in
1029 a temporary slot. */
1030 if (!MEM_P (x) || CONSTANT_P (XEXP (x, 0)))
1033 p = find_temp_slot_from_address (XEXP (x, 0));
1038 /* If X could be a reference to a temporary slot, mark that slot as
1039 belonging to the to one level higher than the current level. If X
1040 matched one of our slots, just mark that one. Otherwise, we can't
1041 easily predict which it is, so upgrade all of them. Kept slots
1042 need not be touched.
1044 This is called when an ({...}) construct occurs and a statement
1045 returns a value in memory. */
1048 preserve_temp_slots (rtx x)
1050 struct temp_slot *p = 0, *next;
1052 /* If there is no result, we still might have some objects whose address
1053 were taken, so we need to make sure they stay around. */
1056 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1061 move_slot_to_level (p, temp_slot_level - 1);
1067 /* If X is a register that is being used as a pointer, see if we have
1068 a temporary slot we know it points to. To be consistent with
1069 the code below, we really should preserve all non-kept slots
1070 if we can't find a match, but that seems to be much too costly. */
1071 if (REG_P (x) && REG_POINTER (x))
1072 p = find_temp_slot_from_address (x);
1074 /* If X is not in memory or is at a constant address, it cannot be in
1075 a temporary slot, but it can contain something whose address was
1077 if (p == 0 && (!MEM_P (x) || CONSTANT_P (XEXP (x, 0))))
1079 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1084 move_slot_to_level (p, temp_slot_level - 1);
1090 /* First see if we can find a match. */
1092 p = find_temp_slot_from_address (XEXP (x, 0));
1096 /* Move everything at our level whose address was taken to our new
1097 level in case we used its address. */
1098 struct temp_slot *q;
1100 if (p->level == temp_slot_level)
1102 for (q = *temp_slots_at_level (temp_slot_level); q; q = next)
1106 if (p != q && q->addr_taken)
1107 move_slot_to_level (q, temp_slot_level - 1);
1110 move_slot_to_level (p, temp_slot_level - 1);
1116 /* Otherwise, preserve all non-kept slots at this level. */
1117 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1122 move_slot_to_level (p, temp_slot_level - 1);
1126 /* Free all temporaries used so far. This is normally called at the
1127 end of generating code for a statement. */
1130 free_temp_slots (void)
1132 struct temp_slot *p, *next;
1134 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1139 make_slot_available (p);
1142 combine_temp_slots ();
1145 /* Push deeper into the nesting level for stack temporaries. */
1148 push_temp_slots (void)
1153 /* Pop a temporary nesting level. All slots in use in the current level
1157 pop_temp_slots (void)
1159 struct temp_slot *p, *next;
1161 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1164 make_slot_available (p);
1167 combine_temp_slots ();
1172 /* Initialize temporary slots. */
1175 init_temp_slots (void)
1177 /* We have not allocated any temporaries yet. */
1178 avail_temp_slots = 0;
1179 used_temp_slots = 0;
1180 temp_slot_level = 0;
1183 /* These routines are responsible for converting virtual register references
1184 to the actual hard register references once RTL generation is complete.
1186 The following four variables are used for communication between the
1187 routines. They contain the offsets of the virtual registers from their
1188 respective hard registers. */
1190 static int in_arg_offset;
1191 static int var_offset;
1192 static int dynamic_offset;
1193 static int out_arg_offset;
1194 static int cfa_offset;
1196 /* In most machines, the stack pointer register is equivalent to the bottom
1199 #ifndef STACK_POINTER_OFFSET
1200 #define STACK_POINTER_OFFSET 0
1203 /* If not defined, pick an appropriate default for the offset of dynamically
1204 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
1205 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
1207 #ifndef STACK_DYNAMIC_OFFSET
1209 /* The bottom of the stack points to the actual arguments. If
1210 REG_PARM_STACK_SPACE is defined, this includes the space for the register
1211 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
1212 stack space for register parameters is not pushed by the caller, but
1213 rather part of the fixed stack areas and hence not included in
1214 `current_function_outgoing_args_size'. Nevertheless, we must allow
1215 for it when allocating stack dynamic objects. */
1217 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
1218 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1219 ((ACCUMULATE_OUTGOING_ARGS \
1220 ? (current_function_outgoing_args_size + REG_PARM_STACK_SPACE (FNDECL)) : 0)\
1221 + (STACK_POINTER_OFFSET)) \
1224 #define STACK_DYNAMIC_OFFSET(FNDECL) \
1225 ((ACCUMULATE_OUTGOING_ARGS ? current_function_outgoing_args_size : 0) \
1226 + (STACK_POINTER_OFFSET))
1230 /* On most machines, the CFA coincides with the first incoming parm. */
1232 #ifndef ARG_POINTER_CFA_OFFSET
1233 #define ARG_POINTER_CFA_OFFSET(FNDECL) FIRST_PARM_OFFSET (FNDECL)
1237 /* Pass through the INSNS of function FNDECL and convert virtual register
1238 references to hard register references. */
1241 instantiate_virtual_regs (void)
1245 /* Compute the offsets to use for this function. */
1246 in_arg_offset = FIRST_PARM_OFFSET (current_function_decl);
1247 var_offset = STARTING_FRAME_OFFSET;
1248 dynamic_offset = STACK_DYNAMIC_OFFSET (current_function_decl);
1249 out_arg_offset = STACK_POINTER_OFFSET;
1250 cfa_offset = ARG_POINTER_CFA_OFFSET (current_function_decl);
1252 /* Scan all variables and parameters of this function. For each that is
1253 in memory, instantiate all virtual registers if the result is a valid
1254 address. If not, we do it later. That will handle most uses of virtual
1255 regs on many machines. */
1256 instantiate_decls (current_function_decl, 1);
1258 /* Initialize recognition, indicating that volatile is OK. */
1261 /* Scan through all the insns, instantiating every virtual register still
1263 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
1264 if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN
1265 || GET_CODE (insn) == CALL_INSN)
1267 instantiate_virtual_regs_1 (&PATTERN (insn), insn, 1);
1268 if (INSN_DELETED_P (insn))
1270 instantiate_virtual_regs_1 (®_NOTES (insn), NULL_RTX, 0);
1271 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
1272 if (GET_CODE (insn) == CALL_INSN)
1273 instantiate_virtual_regs_1 (&CALL_INSN_FUNCTION_USAGE (insn),
1276 /* Past this point all ASM statements should match. Verify that
1277 to avoid failures later in the compilation process. */
1278 if (asm_noperands (PATTERN (insn)) >= 0
1279 && ! check_asm_operands (PATTERN (insn)))
1280 instantiate_virtual_regs_lossage (insn);
1283 /* Now instantiate the remaining register equivalences for debugging info.
1284 These will not be valid addresses. */
1285 instantiate_decls (current_function_decl, 0);
1287 /* Indicate that, from now on, assign_stack_local should use
1288 frame_pointer_rtx. */
1289 virtuals_instantiated = 1;
1292 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
1293 all virtual registers in their DECL_RTL's.
1295 If VALID_ONLY, do this only if the resulting address is still valid.
1296 Otherwise, always do it. */
1299 instantiate_decls (tree fndecl, int valid_only)
1303 /* Process all parameters of the function. */
1304 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = TREE_CHAIN (decl))
1306 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (decl));
1307 HOST_WIDE_INT size_rtl;
1309 instantiate_decl (DECL_RTL (decl), size, valid_only);
1311 /* If the parameter was promoted, then the incoming RTL mode may be
1312 larger than the declared type size. We must use the larger of
1314 size_rtl = GET_MODE_SIZE (GET_MODE (DECL_INCOMING_RTL (decl)));
1315 size = MAX (size_rtl, size);
1316 instantiate_decl (DECL_INCOMING_RTL (decl), size, valid_only);
1319 /* Now process all variables defined in the function or its subblocks. */
1320 instantiate_decls_1 (DECL_INITIAL (fndecl), valid_only);
1323 /* Subroutine of instantiate_decls: Process all decls in the given
1324 BLOCK node and all its subblocks. */
1327 instantiate_decls_1 (tree let, int valid_only)
1331 for (t = BLOCK_VARS (let); t; t = TREE_CHAIN (t))
1332 if (DECL_RTL_SET_P (t))
1333 instantiate_decl (DECL_RTL (t),
1334 int_size_in_bytes (TREE_TYPE (t)),
1337 /* Process all subblocks. */
1338 for (t = BLOCK_SUBBLOCKS (let); t; t = TREE_CHAIN (t))
1339 instantiate_decls_1 (t, valid_only);
1342 /* Subroutine of the preceding procedures: Given RTL representing a
1343 decl and the size of the object, do any instantiation required.
1345 If VALID_ONLY is nonzero, it means that the RTL should only be
1346 changed if the new address is valid. */
1349 instantiate_decl (rtx x, HOST_WIDE_INT size, int valid_only)
1351 enum machine_mode mode;
1354 /* If this is not a MEM, no need to do anything. Similarly if the
1355 address is a constant or a register that is not a virtual register. */
1357 if (x == 0 || !MEM_P (x))
1361 if (CONSTANT_P (addr)
1363 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
1364 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
1367 /* If we should only do this if the address is valid, copy the address.
1368 We need to do this so we can undo any changes that might make the
1369 address invalid. This copy is unfortunate, but probably can't be
1373 addr = copy_rtx (addr);
1375 instantiate_virtual_regs_1 (&addr, NULL_RTX, 0);
1377 if (valid_only && size >= 0)
1379 unsigned HOST_WIDE_INT decl_size = size;
1381 /* Now verify that the resulting address is valid for every integer or
1382 floating-point mode up to and including SIZE bytes long. We do this
1383 since the object might be accessed in any mode and frame addresses
1386 for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
1387 mode != VOIDmode && GET_MODE_SIZE (mode) <= decl_size;
1388 mode = GET_MODE_WIDER_MODE (mode))
1389 if (! memory_address_p (mode, addr))
1392 for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT);
1393 mode != VOIDmode && GET_MODE_SIZE (mode) <= decl_size;
1394 mode = GET_MODE_WIDER_MODE (mode))
1395 if (! memory_address_p (mode, addr))
1399 /* Put back the address now that we have updated it and we either know
1400 it is valid or we don't care whether it is valid. */
1405 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
1406 is a virtual register, return the equivalent hard register and set the
1407 offset indirectly through the pointer. Otherwise, return 0. */
1410 instantiate_new_reg (rtx x, HOST_WIDE_INT *poffset)
1413 HOST_WIDE_INT offset;
1415 if (x == virtual_incoming_args_rtx)
1416 new = arg_pointer_rtx, offset = in_arg_offset;
1417 else if (x == virtual_stack_vars_rtx)
1418 new = frame_pointer_rtx, offset = var_offset;
1419 else if (x == virtual_stack_dynamic_rtx)
1420 new = stack_pointer_rtx, offset = dynamic_offset;
1421 else if (x == virtual_outgoing_args_rtx)
1422 new = stack_pointer_rtx, offset = out_arg_offset;
1423 else if (x == virtual_cfa_rtx)
1424 new = arg_pointer_rtx, offset = cfa_offset;
1433 /* Called when instantiate_virtual_regs has failed to update the instruction.
1434 Usually this means that non-matching instruction has been emit, however for
1435 asm statements it may be the problem in the constraints. */
1437 instantiate_virtual_regs_lossage (rtx insn)
1439 if (asm_noperands (PATTERN (insn)) >= 0)
1441 error_for_asm (insn, "impossible constraint in `asm'");
1447 /* Given a pointer to a piece of rtx and an optional pointer to the
1448 containing object, instantiate any virtual registers present in it.
1450 If EXTRA_INSNS, we always do the replacement and generate
1451 any extra insns before OBJECT. If it zero, we do nothing if replacement
1454 Return 1 if we either had nothing to do or if we were able to do the
1455 needed replacement. Return 0 otherwise; we only return zero if
1456 EXTRA_INSNS is zero.
1458 We first try some simple transformations to avoid the creation of extra
1462 instantiate_virtual_regs_1 (rtx *loc, rtx object, int extra_insns)
1467 HOST_WIDE_INT offset = 0;
1473 /* Re-start here to avoid recursion in common cases. */
1480 /* We may have detected and deleted invalid asm statements. */
1481 if (object && INSN_P (object) && INSN_DELETED_P (object))
1484 code = GET_CODE (x);
1486 /* Check for some special cases. */
1504 /* We are allowed to set the virtual registers. This means that
1505 the actual register should receive the source minus the
1506 appropriate offset. This is used, for example, in the handling
1507 of non-local gotos. */
1508 if ((new = instantiate_new_reg (SET_DEST (x), &offset)) != 0)
1510 rtx src = SET_SRC (x);
1512 /* We are setting the register, not using it, so the relevant
1513 offset is the negative of the offset to use were we using
1516 instantiate_virtual_regs_1 (&src, NULL_RTX, 0);
1518 /* The only valid sources here are PLUS or REG. Just do
1519 the simplest possible thing to handle them. */
1520 if (!REG_P (src) && GET_CODE (src) != PLUS)
1522 instantiate_virtual_regs_lossage (object);
1528 temp = force_operand (src, NULL_RTX);
1531 temp = force_operand (plus_constant (temp, offset), NULL_RTX);
1535 emit_insn_before (seq, object);
1538 if (! validate_change (object, &SET_SRC (x), temp, 0)
1540 instantiate_virtual_regs_lossage (object);
1545 instantiate_virtual_regs_1 (&SET_DEST (x), object, extra_insns);
1550 /* Handle special case of virtual register plus constant. */
1551 if (CONSTANT_P (XEXP (x, 1)))
1553 rtx old, new_offset;
1555 /* Check for (plus (plus VIRT foo) (const_int)) first. */
1556 if (GET_CODE (XEXP (x, 0)) == PLUS)
1558 if ((new = instantiate_new_reg (XEXP (XEXP (x, 0), 0), &offset)))
1560 instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 1), object,
1562 new = gen_rtx_PLUS (Pmode, new, XEXP (XEXP (x, 0), 1));
1571 #ifdef POINTERS_EXTEND_UNSIGNED
1572 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
1573 we can commute the PLUS and SUBREG because pointers into the
1574 frame are well-behaved. */
1575 else if (GET_CODE (XEXP (x, 0)) == SUBREG && GET_MODE (x) == ptr_mode
1576 && GET_CODE (XEXP (x, 1)) == CONST_INT
1578 = instantiate_new_reg (SUBREG_REG (XEXP (x, 0)),
1580 && validate_change (object, loc,
1581 plus_constant (gen_lowpart (ptr_mode,
1584 + INTVAL (XEXP (x, 1))),
1588 else if ((new = instantiate_new_reg (XEXP (x, 0), &offset)) == 0)
1590 /* We know the second operand is a constant. Unless the
1591 first operand is a REG (which has been already checked),
1592 it needs to be checked. */
1593 if (!REG_P (XEXP (x, 0)))
1601 new_offset = plus_constant (XEXP (x, 1), offset);
1603 /* If the new constant is zero, try to replace the sum with just
1605 if (new_offset == const0_rtx
1606 && validate_change (object, loc, new, 0))
1609 /* Next try to replace the register and new offset.
1610 There are two changes to validate here and we can't assume that
1611 in the case of old offset equals new just changing the register
1612 will yield a valid insn. In the interests of a little efficiency,
1613 however, we only call validate change once (we don't queue up the
1614 changes and then call apply_change_group). */
1618 ? ! validate_change (object, &XEXP (x, 0), new, 0)
1619 : (XEXP (x, 0) = new,
1620 ! validate_change (object, &XEXP (x, 1), new_offset, 0)))
1628 /* Otherwise copy the new constant into a register and replace
1629 constant with that register. */
1630 temp = gen_reg_rtx (Pmode);
1632 if (validate_change (object, &XEXP (x, 1), temp, 0))
1633 emit_insn_before (gen_move_insn (temp, new_offset), object);
1636 /* If that didn't work, replace this expression with a
1637 register containing the sum. */
1640 new = gen_rtx_PLUS (Pmode, new, new_offset);
1643 temp = force_operand (new, NULL_RTX);
1647 emit_insn_before (seq, object);
1648 if (! validate_change (object, loc, temp, 0)
1649 && ! validate_replace_rtx (x, temp, object))
1651 instantiate_virtual_regs_lossage (object);
1660 /* Fall through to generic two-operand expression case. */
1666 case DIV: case UDIV:
1667 case MOD: case UMOD:
1668 case AND: case IOR: case XOR:
1669 case ROTATERT: case ROTATE:
1670 case ASHIFTRT: case LSHIFTRT: case ASHIFT:
1672 case GE: case GT: case GEU: case GTU:
1673 case LE: case LT: case LEU: case LTU:
1674 if (XEXP (x, 1) && ! CONSTANT_P (XEXP (x, 1)))
1675 instantiate_virtual_regs_1 (&XEXP (x, 1), object, extra_insns);
1680 /* Most cases of MEM that convert to valid addresses have already been
1681 handled by our scan of decls. The only special handling we
1682 need here is to make a copy of the rtx to ensure it isn't being
1683 shared if we have to change it to a pseudo.
1685 If the rtx is a simple reference to an address via a virtual register,
1686 it can potentially be shared. In such cases, first try to make it
1687 a valid address, which can also be shared. Otherwise, copy it and
1690 First check for common cases that need no processing. These are
1691 usually due to instantiation already being done on a previous instance
1695 if (CONSTANT_ADDRESS_P (temp)
1696 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
1697 || temp == arg_pointer_rtx
1699 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
1700 || temp == hard_frame_pointer_rtx
1702 || temp == frame_pointer_rtx)
1705 if (GET_CODE (temp) == PLUS
1706 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
1707 && (XEXP (temp, 0) == frame_pointer_rtx
1708 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
1709 || XEXP (temp, 0) == hard_frame_pointer_rtx
1711 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
1712 || XEXP (temp, 0) == arg_pointer_rtx
1717 if (temp == virtual_stack_vars_rtx
1718 || temp == virtual_incoming_args_rtx
1719 || (GET_CODE (temp) == PLUS
1720 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
1721 && (XEXP (temp, 0) == virtual_stack_vars_rtx
1722 || XEXP (temp, 0) == virtual_incoming_args_rtx)))
1724 /* This MEM may be shared. If the substitution can be done without
1725 the need to generate new pseudos, we want to do it in place
1726 so all copies of the shared rtx benefit. The call below will
1727 only make substitutions if the resulting address is still
1730 Note that we cannot pass X as the object in the recursive call
1731 since the insn being processed may not allow all valid
1732 addresses. However, if we were not passed on object, we can
1733 only modify X without copying it if X will have a valid
1736 ??? Also note that this can still lose if OBJECT is an insn that
1737 has less restrictions on an address that some other insn.
1738 In that case, we will modify the shared address. This case
1739 doesn't seem very likely, though. One case where this could
1740 happen is in the case of a USE or CLOBBER reference, but we
1741 take care of that below. */
1743 if (instantiate_virtual_regs_1 (&XEXP (x, 0),
1744 object ? object : x, 0))
1747 /* Otherwise make a copy and process that copy. We copy the entire
1748 RTL expression since it might be a PLUS which could also be
1750 *loc = x = copy_rtx (x);
1753 /* Fall through to generic unary operation case. */
1756 case STRICT_LOW_PART:
1758 case PRE_DEC: case PRE_INC: case POST_DEC: case POST_INC:
1759 case SIGN_EXTEND: case ZERO_EXTEND:
1760 case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE:
1761 case FLOAT: case FIX:
1762 case UNSIGNED_FIX: case UNSIGNED_FLOAT:
1767 case POPCOUNT: case PARITY:
1768 /* These case either have just one operand or we know that we need not
1769 check the rest of the operands. */
1775 /* If the operand is a MEM, see if the change is a valid MEM. If not,
1776 go ahead and make the invalid one, but do it to a copy. For a REG,
1777 just make the recursive call, since there's no chance of a problem. */
1779 if ((MEM_P (XEXP (x, 0))
1780 && instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 0), XEXP (x, 0),
1782 || (REG_P (XEXP (x, 0))
1783 && instantiate_virtual_regs_1 (&XEXP (x, 0), object, 0)))
1786 XEXP (x, 0) = copy_rtx (XEXP (x, 0));
1791 /* Try to replace with a PLUS. If that doesn't work, compute the sum
1792 in front of this insn and substitute the temporary. */
1793 if ((new = instantiate_new_reg (x, &offset)) != 0)
1795 temp = plus_constant (new, offset);
1796 if (!validate_change (object, loc, temp, 0))
1802 temp = force_operand (temp, NULL_RTX);
1806 emit_insn_before (seq, object);
1807 if (! validate_change (object, loc, temp, 0)
1808 && ! validate_replace_rtx (x, temp, object))
1809 instantiate_virtual_regs_lossage (object);
1819 /* Scan all subexpressions. */
1820 fmt = GET_RTX_FORMAT (code);
1821 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
1824 if (!instantiate_virtual_regs_1 (&XEXP (x, i), object, extra_insns))
1827 else if (*fmt == 'E')
1828 for (j = 0; j < XVECLEN (x, i); j++)
1829 if (! instantiate_virtual_regs_1 (&XVECEXP (x, i, j), object,
1836 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
1837 This means a type for which function calls must pass an address to the
1838 function or get an address back from the function.
1839 EXP may be a type node or an expression (whose type is tested). */
1842 aggregate_value_p (tree exp, tree fntype)
1844 int i, regno, nregs;
1847 tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
1850 switch (TREE_CODE (fntype))
1853 fntype = get_callee_fndecl (fntype);
1854 fntype = fntype ? TREE_TYPE (fntype) : 0;
1857 fntype = TREE_TYPE (fntype);
1862 case IDENTIFIER_NODE:
1866 /* We don't expect other rtl types here. */
1870 if (TREE_CODE (type) == VOID_TYPE)
1872 /* If the front end has decided that this needs to be passed by
1873 reference, do so. */
1874 if ((TREE_CODE (exp) == PARM_DECL || TREE_CODE (exp) == RESULT_DECL)
1875 && DECL_BY_REFERENCE (exp))
1877 if (targetm.calls.return_in_memory (type, fntype))
1879 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
1880 and thus can't be returned in registers. */
1881 if (TREE_ADDRESSABLE (type))
1883 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
1885 /* Make sure we have suitable call-clobbered regs to return
1886 the value in; if not, we must return it in memory. */
1887 reg = hard_function_value (type, 0, 0);
1889 /* If we have something other than a REG (e.g. a PARALLEL), then assume
1894 regno = REGNO (reg);
1895 nregs = hard_regno_nregs[regno][TYPE_MODE (type)];
1896 for (i = 0; i < nregs; i++)
1897 if (! call_used_regs[regno + i])
1902 /* Return true if we should assign DECL a pseudo register; false if it
1903 should live on the local stack. */
1906 use_register_for_decl (tree decl)
1908 /* Honor volatile. */
1909 if (TREE_SIDE_EFFECTS (decl))
1912 /* Honor addressability. */
1913 if (TREE_ADDRESSABLE (decl))
1916 /* Only register-like things go in registers. */
1917 if (DECL_MODE (decl) == BLKmode)
1920 /* If -ffloat-store specified, don't put explicit float variables
1922 /* ??? This should be checked after DECL_ARTIFICIAL, but tree-ssa
1923 propagates values across these stores, and it probably shouldn't. */
1924 if (flag_float_store && FLOAT_TYPE_P (TREE_TYPE (decl)))
1927 /* Compiler-generated temporaries can always go in registers. */
1928 if (DECL_ARTIFICIAL (decl))
1931 #ifdef NON_SAVING_SETJMP
1932 /* Protect variables not declared "register" from setjmp. */
1933 if (NON_SAVING_SETJMP
1934 && current_function_calls_setjmp
1935 && !DECL_REGISTER (decl))
1939 return (optimize || DECL_REGISTER (decl));
1942 /* Return true if TYPE should be passed by invisible reference. */
1945 pass_by_reference (CUMULATIVE_ARGS *ca, enum machine_mode mode,
1946 tree type, bool named_arg)
1950 /* If this type contains non-trivial constructors, then it is
1951 forbidden for the middle-end to create any new copies. */
1952 if (TREE_ADDRESSABLE (type))
1955 /* GCC post 3.4 passes *all* variable sized types by reference. */
1956 if (!TYPE_SIZE (type) || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
1960 return targetm.calls.pass_by_reference (ca, mode, type, named_arg);
1963 /* Structures to communicate between the subroutines of assign_parms.
1964 The first holds data persistent across all parameters, the second
1965 is cleared out for each parameter. */
1967 struct assign_parm_data_all
1969 CUMULATIVE_ARGS args_so_far;
1970 struct args_size stack_args_size;
1971 tree function_result_decl;
1973 rtx conversion_insns;
1974 HOST_WIDE_INT pretend_args_size;
1975 HOST_WIDE_INT extra_pretend_bytes;
1976 int reg_parm_stack_space;
1979 struct assign_parm_data_one
1985 enum machine_mode nominal_mode;
1986 enum machine_mode passed_mode;
1987 enum machine_mode promoted_mode;
1988 struct locate_and_pad_arg_data locate;
1990 BOOL_BITFIELD named_arg : 1;
1991 BOOL_BITFIELD last_named : 1;
1992 BOOL_BITFIELD passed_pointer : 1;
1993 BOOL_BITFIELD on_stack : 1;
1994 BOOL_BITFIELD loaded_in_reg : 1;
1997 /* A subroutine of assign_parms. Initialize ALL. */
2000 assign_parms_initialize_all (struct assign_parm_data_all *all)
2004 memset (all, 0, sizeof (*all));
2006 fntype = TREE_TYPE (current_function_decl);
2008 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
2009 INIT_CUMULATIVE_INCOMING_ARGS (all->args_so_far, fntype, NULL_RTX);
2011 INIT_CUMULATIVE_ARGS (all->args_so_far, fntype, NULL_RTX,
2012 current_function_decl, -1);
2015 #ifdef REG_PARM_STACK_SPACE
2016 all->reg_parm_stack_space = REG_PARM_STACK_SPACE (current_function_decl);
2020 /* If ARGS contains entries with complex types, split the entry into two
2021 entries of the component type. Return a new list of substitutions are
2022 needed, else the old list. */
2025 split_complex_args (tree args)
2029 /* Before allocating memory, check for the common case of no complex. */
2030 for (p = args; p; p = TREE_CHAIN (p))
2032 tree type = TREE_TYPE (p);
2033 if (TREE_CODE (type) == COMPLEX_TYPE
2034 && targetm.calls.split_complex_arg (type))
2040 args = copy_list (args);
2042 for (p = args; p; p = TREE_CHAIN (p))
2044 tree type = TREE_TYPE (p);
2045 if (TREE_CODE (type) == COMPLEX_TYPE
2046 && targetm.calls.split_complex_arg (type))
2049 tree subtype = TREE_TYPE (type);
2051 /* Rewrite the PARM_DECL's type with its component. */
2052 TREE_TYPE (p) = subtype;
2053 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
2054 DECL_MODE (p) = VOIDmode;
2055 DECL_SIZE (p) = NULL;
2056 DECL_SIZE_UNIT (p) = NULL;
2059 /* Build a second synthetic decl. */
2060 decl = build_decl (PARM_DECL, NULL_TREE, subtype);
2061 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
2062 layout_decl (decl, 0);
2064 /* Splice it in; skip the new decl. */
2065 TREE_CHAIN (decl) = TREE_CHAIN (p);
2066 TREE_CHAIN (p) = decl;
2074 /* A subroutine of assign_parms. Adjust the parameter list to incorporate
2075 the hidden struct return argument, and (abi willing) complex args.
2076 Return the new parameter list. */
2079 assign_parms_augmented_arg_list (struct assign_parm_data_all *all)
2081 tree fndecl = current_function_decl;
2082 tree fntype = TREE_TYPE (fndecl);
2083 tree fnargs = DECL_ARGUMENTS (fndecl);
2085 /* If struct value address is treated as the first argument, make it so. */
2086 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
2087 && ! current_function_returns_pcc_struct
2088 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
2090 tree type = build_pointer_type (TREE_TYPE (fntype));
2093 decl = build_decl (PARM_DECL, NULL_TREE, type);
2094 DECL_ARG_TYPE (decl) = type;
2095 DECL_ARTIFICIAL (decl) = 1;
2097 TREE_CHAIN (decl) = fnargs;
2099 all->function_result_decl = decl;
2102 all->orig_fnargs = fnargs;
2104 /* If the target wants to split complex arguments into scalars, do so. */
2105 if (targetm.calls.split_complex_arg)
2106 fnargs = split_complex_args (fnargs);
2111 /* A subroutine of assign_parms. Examine PARM and pull out type and mode
2112 data for the parameter. Incorporate ABI specifics such as pass-by-
2113 reference and type promotion. */
2116 assign_parm_find_data_types (struct assign_parm_data_all *all, tree parm,
2117 struct assign_parm_data_one *data)
2119 tree nominal_type, passed_type;
2120 enum machine_mode nominal_mode, passed_mode, promoted_mode;
2122 memset (data, 0, sizeof (*data));
2124 /* Set LAST_NAMED if this is last named arg before last anonymous args. */
2125 if (current_function_stdarg)
2128 for (tem = TREE_CHAIN (parm); tem; tem = TREE_CHAIN (tem))
2129 if (DECL_NAME (tem))
2132 data->last_named = true;
2135 /* Set NAMED_ARG if this arg should be treated as a named arg. For
2136 most machines, if this is a varargs/stdarg function, then we treat
2137 the last named arg as if it were anonymous too. */
2138 if (targetm.calls.strict_argument_naming (&all->args_so_far))
2139 data->named_arg = 1;
2141 data->named_arg = !data->last_named;
2143 nominal_type = TREE_TYPE (parm);
2144 passed_type = DECL_ARG_TYPE (parm);
2146 /* Look out for errors propagating this far. Also, if the parameter's
2147 type is void then its value doesn't matter. */
2148 if (TREE_TYPE (parm) == error_mark_node
2149 /* This can happen after weird syntax errors
2150 or if an enum type is defined among the parms. */
2151 || TREE_CODE (parm) != PARM_DECL
2152 || passed_type == NULL
2153 || VOID_TYPE_P (nominal_type))
2155 nominal_type = passed_type = void_type_node;
2156 nominal_mode = passed_mode = promoted_mode = VOIDmode;
2160 /* Find mode of arg as it is passed, and mode of arg as it should be
2161 during execution of this function. */
2162 passed_mode = TYPE_MODE (passed_type);
2163 nominal_mode = TYPE_MODE (nominal_type);
2165 /* If the parm is to be passed as a transparent union, use the type of
2166 the first field for the tests below. We have already verified that
2167 the modes are the same. */
2168 if (DECL_TRANSPARENT_UNION (parm)
2169 || (TREE_CODE (passed_type) == UNION_TYPE
2170 && TYPE_TRANSPARENT_UNION (passed_type)))
2171 passed_type = TREE_TYPE (TYPE_FIELDS (passed_type));
2173 /* See if this arg was passed by invisible reference. */
2174 if (pass_by_reference (&all->args_so_far, passed_mode,
2175 passed_type, data->named_arg))
2177 passed_type = nominal_type = build_pointer_type (passed_type);
2178 data->passed_pointer = true;
2179 passed_mode = nominal_mode = Pmode;
2182 /* Find mode as it is passed by the ABI. */
2183 promoted_mode = passed_mode;
2184 if (targetm.calls.promote_function_args (TREE_TYPE (current_function_decl)))
2186 int unsignedp = TYPE_UNSIGNED (passed_type);
2187 promoted_mode = promote_mode (passed_type, promoted_mode,
2192 data->nominal_type = nominal_type;
2193 data->passed_type = passed_type;
2194 data->nominal_mode = nominal_mode;
2195 data->passed_mode = passed_mode;
2196 data->promoted_mode = promoted_mode;
2199 /* A subroutine of assign_parms. Invoke setup_incoming_varargs. */
2202 assign_parms_setup_varargs (struct assign_parm_data_all *all,
2203 struct assign_parm_data_one *data, bool no_rtl)
2205 int varargs_pretend_bytes = 0;
2207 targetm.calls.setup_incoming_varargs (&all->args_so_far,
2208 data->promoted_mode,
2210 &varargs_pretend_bytes, no_rtl);
2212 /* If the back-end has requested extra stack space, record how much is
2213 needed. Do not change pretend_args_size otherwise since it may be
2214 nonzero from an earlier partial argument. */
2215 if (varargs_pretend_bytes > 0)
2216 all->pretend_args_size = varargs_pretend_bytes;
2219 /* A subroutine of assign_parms. Set DATA->ENTRY_PARM corresponding to
2220 the incoming location of the current parameter. */
2223 assign_parm_find_entry_rtl (struct assign_parm_data_all *all,
2224 struct assign_parm_data_one *data)
2226 HOST_WIDE_INT pretend_bytes = 0;
2230 if (data->promoted_mode == VOIDmode)
2232 data->entry_parm = data->stack_parm = const0_rtx;
2236 #ifdef FUNCTION_INCOMING_ARG
2237 entry_parm = FUNCTION_INCOMING_ARG (all->args_so_far, data->promoted_mode,
2238 data->passed_type, data->named_arg);
2240 entry_parm = FUNCTION_ARG (all->args_so_far, data->promoted_mode,
2241 data->passed_type, data->named_arg);
2244 if (entry_parm == 0)
2245 data->promoted_mode = data->passed_mode;
2247 /* Determine parm's home in the stack, in case it arrives in the stack
2248 or we should pretend it did. Compute the stack position and rtx where
2249 the argument arrives and its size.
2251 There is one complexity here: If this was a parameter that would
2252 have been passed in registers, but wasn't only because it is
2253 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
2254 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
2255 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of 0
2256 as it was the previous time. */
2257 in_regs = entry_parm != 0;
2258 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2261 if (!in_regs && !data->named_arg)
2263 if (targetm.calls.pretend_outgoing_varargs_named (&all->args_so_far))
2266 #ifdef FUNCTION_INCOMING_ARG
2267 tem = FUNCTION_INCOMING_ARG (all->args_so_far, data->promoted_mode,
2268 data->passed_type, true);
2270 tem = FUNCTION_ARG (all->args_so_far, data->promoted_mode,
2271 data->passed_type, true);
2273 in_regs = tem != NULL;
2277 /* If this parameter was passed both in registers and in the stack, use
2278 the copy on the stack. */
2279 if (targetm.calls.must_pass_in_stack (data->promoted_mode,
2287 partial = FUNCTION_ARG_PARTIAL_NREGS (all->args_so_far,
2288 data->promoted_mode,
2291 data->partial = partial;
2293 /* The caller might already have allocated stack space for the
2294 register parameters. */
2295 if (partial != 0 && all->reg_parm_stack_space == 0)
2297 /* Part of this argument is passed in registers and part
2298 is passed on the stack. Ask the prologue code to extend
2299 the stack part so that we can recreate the full value.
2301 PRETEND_BYTES is the size of the registers we need to store.
2302 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
2303 stack space that the prologue should allocate.
2305 Internally, gcc assumes that the argument pointer is aligned
2306 to STACK_BOUNDARY bits. This is used both for alignment
2307 optimizations (see init_emit) and to locate arguments that are
2308 aligned to more than PARM_BOUNDARY bits. We must preserve this
2309 invariant by rounding CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to
2310 a stack boundary. */
2312 /* We assume at most one partial arg, and it must be the first
2313 argument on the stack. */
2314 if (all->extra_pretend_bytes || all->pretend_args_size)
2317 pretend_bytes = partial * UNITS_PER_WORD;
2318 all->pretend_args_size = CEIL_ROUND (pretend_bytes, STACK_BYTES);
2320 /* We want to align relative to the actual stack pointer, so
2321 don't include this in the stack size until later. */
2322 all->extra_pretend_bytes = all->pretend_args_size;
2326 locate_and_pad_parm (data->promoted_mode, data->passed_type, in_regs,
2327 entry_parm ? data->partial : 0, current_function_decl,
2328 &all->stack_args_size, &data->locate);
2330 /* Adjust offsets to include the pretend args. */
2331 pretend_bytes = all->extra_pretend_bytes - pretend_bytes;
2332 data->locate.slot_offset.constant += pretend_bytes;
2333 data->locate.offset.constant += pretend_bytes;
2335 data->entry_parm = entry_parm;
2338 /* A subroutine of assign_parms. If there is actually space on the stack
2339 for this parm, count it in stack_args_size and return true. */
2342 assign_parm_is_stack_parm (struct assign_parm_data_all *all,
2343 struct assign_parm_data_one *data)
2345 /* Trivially true if we've no incomming register. */
2346 if (data->entry_parm == NULL)
2348 /* Also true if we're partially in registers and partially not,
2349 since we've arranged to drop the entire argument on the stack. */
2350 else if (data->partial != 0)
2352 /* Also true if the target says that it's passed in both registers
2353 and on the stack. */
2354 else if (GET_CODE (data->entry_parm) == PARALLEL
2355 && XEXP (XVECEXP (data->entry_parm, 0, 0), 0) == NULL_RTX)
2357 /* Also true if the target says that there's stack allocated for
2358 all register parameters. */
2359 else if (all->reg_parm_stack_space > 0)
2361 /* Otherwise, no, this parameter has no ABI defined stack slot. */
2365 all->stack_args_size.constant += data->locate.size.constant;
2366 if (data->locate.size.var)
2367 ADD_PARM_SIZE (all->stack_args_size, data->locate.size.var);
2372 /* A subroutine of assign_parms. Given that this parameter is allocated
2373 stack space by the ABI, find it. */
2376 assign_parm_find_stack_rtl (tree parm, struct assign_parm_data_one *data)
2378 rtx offset_rtx, stack_parm;
2379 unsigned int align, boundary;
2381 /* If we're passing this arg using a reg, make its stack home the
2382 aligned stack slot. */
2383 if (data->entry_parm)
2384 offset_rtx = ARGS_SIZE_RTX (data->locate.slot_offset);
2386 offset_rtx = ARGS_SIZE_RTX (data->locate.offset);
2388 stack_parm = current_function_internal_arg_pointer;
2389 if (offset_rtx != const0_rtx)
2390 stack_parm = gen_rtx_PLUS (Pmode, stack_parm, offset_rtx);
2391 stack_parm = gen_rtx_MEM (data->promoted_mode, stack_parm);
2393 set_mem_attributes (stack_parm, parm, 1);
2395 boundary = FUNCTION_ARG_BOUNDARY (data->promoted_mode, data->passed_type);
2398 /* If we're padding upward, we know that the alignment of the slot
2399 is FUNCTION_ARG_BOUNDARY. If we're using slot_offset, we're
2400 intentionally forcing upward padding. Otherwise we have to come
2401 up with a guess at the alignment based on OFFSET_RTX. */
2402 if (data->locate.where_pad == upward || data->entry_parm)
2404 else if (GET_CODE (offset_rtx) == CONST_INT)
2406 align = INTVAL (offset_rtx) * BITS_PER_UNIT | boundary;
2407 align = align & -align;
2410 set_mem_align (stack_parm, align);
2412 if (data->entry_parm)
2413 set_reg_attrs_for_parm (data->entry_parm, stack_parm);
2415 data->stack_parm = stack_parm;
2418 /* A subroutine of assign_parms. Adjust DATA->ENTRY_RTL such that it's
2419 always valid and contiguous. */
2422 assign_parm_adjust_entry_rtl (struct assign_parm_data_one *data)
2424 rtx entry_parm = data->entry_parm;
2425 rtx stack_parm = data->stack_parm;
2427 /* If this parm was passed part in regs and part in memory, pretend it
2428 arrived entirely in memory by pushing the register-part onto the stack.
2429 In the special case of a DImode or DFmode that is split, we could put
2430 it together in a pseudoreg directly, but for now that's not worth
2432 if (data->partial != 0)
2434 /* Handle calls that pass values in multiple non-contiguous
2435 locations. The Irix 6 ABI has examples of this. */
2436 if (GET_CODE (entry_parm) == PARALLEL)
2437 emit_group_store (validize_mem (stack_parm), entry_parm,
2439 int_size_in_bytes (data->passed_type));
2441 move_block_from_reg (REGNO (entry_parm), validize_mem (stack_parm),
2444 entry_parm = stack_parm;
2447 /* If we didn't decide this parm came in a register, by default it came
2449 else if (entry_parm == NULL)
2450 entry_parm = stack_parm;
2452 /* When an argument is passed in multiple locations, we can't make use
2453 of this information, but we can save some copying if the whole argument
2454 is passed in a single register. */
2455 else if (GET_CODE (entry_parm) == PARALLEL
2456 && data->nominal_mode != BLKmode
2457 && data->passed_mode != BLKmode)
2459 size_t i, len = XVECLEN (entry_parm, 0);
2461 for (i = 0; i < len; i++)
2462 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
2463 && REG_P (XEXP (XVECEXP (entry_parm, 0, i), 0))
2464 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
2465 == data->passed_mode)
2466 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
2468 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
2473 data->entry_parm = entry_parm;
2476 /* A subroutine of assign_parms. Adjust DATA->STACK_RTL such that it's
2477 always valid and properly aligned. */
2481 assign_parm_adjust_stack_rtl (struct assign_parm_data_one *data)
2483 rtx stack_parm = data->stack_parm;
2485 /* If we can't trust the parm stack slot to be aligned enough for its
2486 ultimate type, don't use that slot after entry. We'll make another
2487 stack slot, if we need one. */
2488 if (STRICT_ALIGNMENT && stack_parm
2489 && GET_MODE_ALIGNMENT (data->nominal_mode) > MEM_ALIGN (stack_parm))
2492 /* If parm was passed in memory, and we need to convert it on entry,
2493 don't store it back in that same slot. */
2494 else if (data->entry_parm == stack_parm
2495 && data->nominal_mode != BLKmode
2496 && data->nominal_mode != data->passed_mode)
2499 data->stack_parm = stack_parm;
2502 /* A subroutine of assign_parms. Return true if the current parameter
2503 should be stored as a BLKmode in the current frame. */
2506 assign_parm_setup_block_p (struct assign_parm_data_one *data)
2508 if (data->nominal_mode == BLKmode)
2510 if (GET_CODE (data->entry_parm) == PARALLEL)
2513 #ifdef BLOCK_REG_PADDING
2514 if (data->locate.where_pad == (BYTES_BIG_ENDIAN ? upward : downward)
2515 && GET_MODE_SIZE (data->promoted_mode) < UNITS_PER_WORD)
2522 /* A subroutine of assign_parms. Arrange for the parameter to be
2523 present and valid in DATA->STACK_RTL. */
2526 assign_parm_setup_block (tree parm, struct assign_parm_data_one *data)
2528 rtx entry_parm = data->entry_parm;
2529 rtx stack_parm = data->stack_parm;
2531 /* If we've a non-block object that's nevertheless passed in parts,
2532 reconstitute it in register operations rather than on the stack. */
2533 if (GET_CODE (entry_parm) == PARALLEL
2534 && data->nominal_mode != BLKmode
2535 && XVECLEN (entry_parm, 0) > 1
2538 rtx parmreg = gen_reg_rtx (data->nominal_mode);
2540 emit_group_store (parmreg, entry_parm, data->nominal_type,
2541 int_size_in_bytes (data->nominal_type));
2542 SET_DECL_RTL (parm, parmreg);
2546 /* If a BLKmode arrives in registers, copy it to a stack slot. Handle
2547 calls that pass values in multiple non-contiguous locations. */
2548 if (REG_P (entry_parm) || GET_CODE (entry_parm) == PARALLEL)
2550 HOST_WIDE_INT size = int_size_in_bytes (data->passed_type);
2551 HOST_WIDE_INT size_stored = CEIL_ROUND (size, UNITS_PER_WORD);
2554 /* Note that we will be storing an integral number of words.
2555 So we have to be careful to ensure that we allocate an
2556 integral number of words. We do this below in the
2557 assign_stack_local if space was not allocated in the argument
2558 list. If it was, this will not work if PARM_BOUNDARY is not
2559 a multiple of BITS_PER_WORD. It isn't clear how to fix this
2560 if it becomes a problem. Exception is when BLKmode arrives
2561 with arguments not conforming to word_mode. */
2563 if (stack_parm == 0)
2565 stack_parm = assign_stack_local (BLKmode, size_stored, 0);
2566 data->stack_parm = stack_parm;
2567 PUT_MODE (stack_parm, GET_MODE (entry_parm));
2568 set_mem_attributes (stack_parm, parm, 1);
2570 else if (GET_CODE (entry_parm) == PARALLEL)
2572 else if (size != 0 && PARM_BOUNDARY % BITS_PER_WORD != 0)
2575 mem = validize_mem (stack_parm);
2577 /* Handle values in multiple non-contiguous locations. */
2578 if (GET_CODE (entry_parm) == PARALLEL)
2579 emit_group_store (mem, entry_parm, data->passed_type, size);
2584 /* If SIZE is that of a mode no bigger than a word, just use
2585 that mode's store operation. */
2586 else if (size <= UNITS_PER_WORD)
2588 enum machine_mode mode
2589 = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
2592 #ifdef BLOCK_REG_PADDING
2593 && (size == UNITS_PER_WORD
2594 || (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2595 != (BYTES_BIG_ENDIAN ? upward : downward)))
2599 rtx reg = gen_rtx_REG (mode, REGNO (entry_parm));
2600 emit_move_insn (change_address (mem, mode, 0), reg);
2603 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
2604 machine must be aligned to the left before storing
2605 to memory. Note that the previous test doesn't
2606 handle all cases (e.g. SIZE == 3). */
2607 else if (size != UNITS_PER_WORD
2608 #ifdef BLOCK_REG_PADDING
2609 && (BLOCK_REG_PADDING (mode, data->passed_type, 1)
2617 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
2618 rtx reg = gen_rtx_REG (word_mode, REGNO (data->entry_parm));
2620 x = expand_shift (LSHIFT_EXPR, word_mode, reg,
2621 build_int_2 (by, 0), NULL_RTX, 1);
2622 tem = change_address (mem, word_mode, 0);
2623 emit_move_insn (tem, x);
2626 move_block_from_reg (REGNO (data->entry_parm), mem,
2627 size_stored / UNITS_PER_WORD);
2630 move_block_from_reg (REGNO (data->entry_parm), mem,
2631 size_stored / UNITS_PER_WORD);
2634 SET_DECL_RTL (parm, stack_parm);
2637 /* A subroutine of assign_parms. Allocate a pseudo to hold the current
2638 parameter. Get it there. Perform all ABI specified conversions. */
2641 assign_parm_setup_reg (struct assign_parm_data_all *all, tree parm,
2642 struct assign_parm_data_one *data)
2645 enum machine_mode promoted_nominal_mode;
2646 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (parm));
2647 bool did_conversion = false;
2649 /* Store the parm in a pseudoregister during the function, but we may
2650 need to do it in a wider mode. */
2652 promoted_nominal_mode
2653 = promote_mode (data->nominal_type, data->nominal_mode, &unsignedp, 0);
2655 parmreg = gen_reg_rtx (promoted_nominal_mode);
2657 if (!DECL_ARTIFICIAL (parm))
2658 mark_user_reg (parmreg);
2660 /* If this was an item that we received a pointer to,
2661 set DECL_RTL appropriately. */
2662 if (data->passed_pointer)
2664 rtx x = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (data->passed_type)), parmreg);
2665 set_mem_attributes (x, parm, 1);
2666 SET_DECL_RTL (parm, x);
2670 SET_DECL_RTL (parm, parmreg);
2671 maybe_set_unchanging (DECL_RTL (parm), parm);
2674 /* Copy the value into the register. */
2675 if (data->nominal_mode != data->passed_mode
2676 || promoted_nominal_mode != data->promoted_mode)
2680 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
2681 mode, by the caller. We now have to convert it to
2682 NOMINAL_MODE, if different. However, PARMREG may be in
2683 a different mode than NOMINAL_MODE if it is being stored
2686 If ENTRY_PARM is a hard register, it might be in a register
2687 not valid for operating in its mode (e.g., an odd-numbered
2688 register for a DFmode). In that case, moves are the only
2689 thing valid, so we can't do a convert from there. This
2690 occurs when the calling sequence allow such misaligned
2693 In addition, the conversion may involve a call, which could
2694 clobber parameters which haven't been copied to pseudo
2695 registers yet. Therefore, we must first copy the parm to
2696 a pseudo reg here, and save the conversion until after all
2697 parameters have been moved. */
2699 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
2701 emit_move_insn (tempreg, validize_mem (data->entry_parm));
2703 push_to_sequence (all->conversion_insns);
2704 tempreg = convert_to_mode (data->nominal_mode, tempreg, unsignedp);
2706 if (GET_CODE (tempreg) == SUBREG
2707 && GET_MODE (tempreg) == data->nominal_mode
2708 && REG_P (SUBREG_REG (tempreg))
2709 && data->nominal_mode == data->passed_mode
2710 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (data->entry_parm)
2711 && GET_MODE_SIZE (GET_MODE (tempreg))
2712 < GET_MODE_SIZE (GET_MODE (data->entry_parm)))
2714 /* The argument is already sign/zero extended, so note it
2716 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
2717 SUBREG_PROMOTED_UNSIGNED_SET (tempreg, unsignedp);
2720 /* TREE_USED gets set erroneously during expand_assignment. */
2721 save_tree_used = TREE_USED (parm);
2722 expand_assignment (parm, make_tree (data->nominal_type, tempreg), 0);
2723 TREE_USED (parm) = save_tree_used;
2724 all->conversion_insns = get_insns ();
2727 did_conversion = true;
2730 emit_move_insn (parmreg, validize_mem (data->entry_parm));
2732 /* If we were passed a pointer but the actual value can safely live
2733 in a register, put it in one. */
2734 if (data->passed_pointer
2735 && TYPE_MODE (TREE_TYPE (parm)) != BLKmode
2736 /* If by-reference argument was promoted, demote it. */
2737 && (TYPE_MODE (TREE_TYPE (parm)) != GET_MODE (DECL_RTL (parm))
2738 || use_register_for_decl (parm)))
2740 /* We can't use nominal_mode, because it will have been set to
2741 Pmode above. We must use the actual mode of the parm. */
2742 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
2743 mark_user_reg (parmreg);
2745 if (GET_MODE (parmreg) != GET_MODE (DECL_RTL (parm)))
2747 rtx tempreg = gen_reg_rtx (GET_MODE (DECL_RTL (parm)));
2748 int unsigned_p = TYPE_UNSIGNED (TREE_TYPE (parm));
2750 push_to_sequence (all->conversion_insns);
2751 emit_move_insn (tempreg, DECL_RTL (parm));
2752 tempreg = convert_to_mode (GET_MODE (parmreg), tempreg, unsigned_p);
2753 emit_move_insn (parmreg, tempreg);
2754 all->conversion_insns = get_insns();
2757 did_conversion = true;
2760 emit_move_insn (parmreg, DECL_RTL (parm));
2762 SET_DECL_RTL (parm, parmreg);
2764 /* STACK_PARM is the pointer, not the parm, and PARMREG is
2766 data->stack_parm = NULL;
2769 /* If we are passed an arg by reference and it is our responsibility
2770 to make a copy, do it now.
2771 PASSED_TYPE and PASSED mode now refer to the pointer, not the
2772 original argument, so we must recreate them in the call to
2773 FUNCTION_ARG_CALLEE_COPIES. */
2774 /* ??? Later add code to handle the case that if the argument isn't
2775 modified, don't do the copy. */
2777 else if (data->passed_pointer)
2779 tree type = TREE_TYPE (data->passed_type);
2781 if (FUNCTION_ARG_CALLEE_COPIES (all->args_so_far, TYPE_MODE (type),
2782 type, data->named_arg)
2783 && !TREE_ADDRESSABLE (type))
2787 /* This sequence may involve a library call perhaps clobbering
2788 registers that haven't been copied to pseudos yet. */
2790 push_to_sequence (all->conversion_insns);
2792 if (!COMPLETE_TYPE_P (type)
2793 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
2795 /* This is a variable sized object. */
2796 copy = allocate_dynamic_stack_space (expr_size (parm), NULL_RTX,
2798 copy = gen_rtx_MEM (BLKmode, copy);
2801 copy = assign_stack_temp (TYPE_MODE (type),
2802 int_size_in_bytes (type), 1);
2803 set_mem_attributes (copy, parm, 1);
2805 store_expr (parm, copy, 0);
2806 emit_move_insn (parmreg, XEXP (copy, 0));
2807 all->conversion_insns = get_insns ();
2810 did_conversion = true;
2814 /* Mark the register as eliminable if we did no conversion and it was
2815 copied from memory at a fixed offset, and the arg pointer was not
2816 copied to a pseudo-reg. If the arg pointer is a pseudo reg or the
2817 offset formed an invalid address, such memory-equivalences as we
2818 make here would screw up life analysis for it. */
2819 if (data->nominal_mode == data->passed_mode
2821 && data->stack_parm != 0
2822 && MEM_P (data->stack_parm)
2823 && data->locate.offset.var == 0
2824 && reg_mentioned_p (virtual_incoming_args_rtx,
2825 XEXP (data->stack_parm, 0)))
2827 rtx linsn = get_last_insn ();
2830 /* Mark complex types separately. */
2831 if (GET_CODE (parmreg) == CONCAT)
2833 enum machine_mode submode
2834 = GET_MODE_INNER (GET_MODE (parmreg));
2835 int regnor = REGNO (gen_realpart (submode, parmreg));
2836 int regnoi = REGNO (gen_imagpart (submode, parmreg));
2837 rtx stackr = gen_realpart (submode, data->stack_parm);
2838 rtx stacki = gen_imagpart (submode, data->stack_parm);
2840 /* Scan backwards for the set of the real and
2842 for (sinsn = linsn; sinsn != 0;
2843 sinsn = prev_nonnote_insn (sinsn))
2845 set = single_set (sinsn);
2849 if (SET_DEST (set) == regno_reg_rtx [regnoi])
2851 = gen_rtx_EXPR_LIST (REG_EQUIV, stacki,
2853 else if (SET_DEST (set) == regno_reg_rtx [regnor])
2855 = gen_rtx_EXPR_LIST (REG_EQUIV, stackr,
2859 else if ((set = single_set (linsn)) != 0
2860 && SET_DEST (set) == parmreg)
2862 = gen_rtx_EXPR_LIST (REG_EQUIV,
2863 data->stack_parm, REG_NOTES (linsn));
2866 /* For pointer data type, suggest pointer register. */
2867 if (POINTER_TYPE_P (TREE_TYPE (parm)))
2868 mark_reg_pointer (parmreg,
2869 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
2872 /* A subroutine of assign_parms. Allocate stack space to hold the current
2873 parameter. Get it there. Perform all ABI specified conversions. */
2876 assign_parm_setup_stack (struct assign_parm_data_all *all, tree parm,
2877 struct assign_parm_data_one *data)
2879 /* Value must be stored in the stack slot STACK_PARM during function
2882 if (data->promoted_mode != data->nominal_mode)
2884 /* Conversion is required. */
2885 rtx tempreg = gen_reg_rtx (GET_MODE (data->entry_parm));
2887 emit_move_insn (tempreg, validize_mem (data->entry_parm));
2889 push_to_sequence (all->conversion_insns);
2890 data->entry_parm = convert_to_mode (data->nominal_mode, tempreg,
2891 TYPE_UNSIGNED (TREE_TYPE (parm)));
2893 if (data->stack_parm)
2894 /* ??? This may need a big-endian conversion on sparc64. */
2896 = adjust_address (data->stack_parm, data->nominal_mode, 0);
2898 all->conversion_insns = get_insns ();
2902 if (data->entry_parm != data->stack_parm)
2904 if (data->stack_parm == 0)
2907 = assign_stack_local (GET_MODE (data->entry_parm),
2908 GET_MODE_SIZE (GET_MODE (data->entry_parm)),
2910 set_mem_attributes (data->stack_parm, parm, 1);
2913 if (data->promoted_mode != data->nominal_mode)
2915 push_to_sequence (all->conversion_insns);
2916 emit_move_insn (validize_mem (data->stack_parm),
2917 validize_mem (data->entry_parm));
2918 all->conversion_insns = get_insns ();
2922 emit_move_insn (validize_mem (data->stack_parm),
2923 validize_mem (data->entry_parm));
2926 SET_DECL_RTL (parm, data->stack_parm);
2929 /* A subroutine of assign_parms. If the ABI splits complex arguments, then
2930 undo the frobbing that we did in assign_parms_augmented_arg_list. */
2933 assign_parms_unsplit_complex (tree orig_fnargs, tree fnargs)
2937 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm))
2939 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
2940 && targetm.calls.split_complex_arg (TREE_TYPE (parm)))
2942 rtx tmp, real, imag;
2943 enum machine_mode inner = GET_MODE_INNER (DECL_MODE (parm));
2945 real = DECL_RTL (fnargs);
2946 imag = DECL_RTL (TREE_CHAIN (fnargs));
2947 if (inner != GET_MODE (real))
2949 real = gen_lowpart_SUBREG (inner, real);
2950 imag = gen_lowpart_SUBREG (inner, imag);
2952 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
2953 SET_DECL_RTL (parm, tmp);
2955 real = DECL_INCOMING_RTL (fnargs);
2956 imag = DECL_INCOMING_RTL (TREE_CHAIN (fnargs));
2957 if (inner != GET_MODE (real))
2959 real = gen_lowpart_SUBREG (inner, real);
2960 imag = gen_lowpart_SUBREG (inner, imag);
2962 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
2963 set_decl_incoming_rtl (parm, tmp);
2964 fnargs = TREE_CHAIN (fnargs);
2968 SET_DECL_RTL (parm, DECL_RTL (fnargs));
2969 set_decl_incoming_rtl (parm, DECL_INCOMING_RTL (fnargs));
2971 /* Set MEM_EXPR to the original decl, i.e. to PARM,
2972 instead of the copy of decl, i.e. FNARGS. */
2973 if (DECL_INCOMING_RTL (parm) && MEM_P (DECL_INCOMING_RTL (parm)))
2974 set_mem_expr (DECL_INCOMING_RTL (parm), parm);
2977 fnargs = TREE_CHAIN (fnargs);
2981 /* Assign RTL expressions to the function's parameters. This may involve
2982 copying them into registers and using those registers as the DECL_RTL. */
2985 assign_parms (tree fndecl)
2987 struct assign_parm_data_all all;
2989 rtx internal_arg_pointer;
2990 int varargs_setup = 0;
2992 /* If the reg that the virtual arg pointer will be translated into is
2993 not a fixed reg or is the stack pointer, make a copy of the virtual
2994 arg pointer, and address parms via the copy. The frame pointer is
2995 considered fixed even though it is not marked as such.
2997 The second time through, simply use ap to avoid generating rtx. */
2999 if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
3000 || ! (fixed_regs[ARG_POINTER_REGNUM]
3001 || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
3002 internal_arg_pointer = copy_to_reg (virtual_incoming_args_rtx);
3004 internal_arg_pointer = virtual_incoming_args_rtx;
3005 current_function_internal_arg_pointer = internal_arg_pointer;
3007 assign_parms_initialize_all (&all);
3008 fnargs = assign_parms_augmented_arg_list (&all);
3010 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
3012 struct assign_parm_data_one data;
3014 /* Extract the type of PARM; adjust it according to ABI. */
3015 assign_parm_find_data_types (&all, parm, &data);
3017 /* Early out for errors and void parameters. */
3018 if (data.passed_mode == VOIDmode)
3020 SET_DECL_RTL (parm, const0_rtx);
3021 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
3025 /* Handle stdargs. LAST_NAMED is a slight mis-nomer; it's also true
3026 for the unnamed dummy argument following the last named argument.
3027 See ABI silliness wrt strict_argument_naming and NAMED_ARG. So
3028 we only want to do this when we get to the actual last named
3029 argument, which will be the first time LAST_NAMED gets set. */
3030 if (data.last_named && !varargs_setup)
3032 varargs_setup = true;
3033 assign_parms_setup_varargs (&all, &data, false);
3036 /* Find out where the parameter arrives in this function. */
3037 assign_parm_find_entry_rtl (&all, &data);
3039 /* Find out where stack space for this parameter might be. */
3040 if (assign_parm_is_stack_parm (&all, &data))
3042 assign_parm_find_stack_rtl (parm, &data);
3043 assign_parm_adjust_entry_rtl (&data);
3046 /* Record permanently how this parm was passed. */
3047 set_decl_incoming_rtl (parm, data.entry_parm);
3049 /* Update info on where next arg arrives in registers. */
3050 FUNCTION_ARG_ADVANCE (all.args_so_far, data.promoted_mode,
3051 data.passed_type, data.named_arg);
3053 assign_parm_adjust_stack_rtl (&data);
3055 if (assign_parm_setup_block_p (&data))
3056 assign_parm_setup_block (parm, &data);
3057 else if (data.passed_pointer || use_register_for_decl (parm))
3058 assign_parm_setup_reg (&all, parm, &data);
3060 assign_parm_setup_stack (&all, parm, &data);
3063 if (targetm.calls.split_complex_arg && fnargs != all.orig_fnargs)
3064 assign_parms_unsplit_complex (all.orig_fnargs, fnargs);
3066 /* Output all parameter conversion instructions (possibly including calls)
3067 now that all parameters have been copied out of hard registers. */
3068 emit_insn (all.conversion_insns);
3070 /* If we are receiving a struct value address as the first argument, set up
3071 the RTL for the function result. As this might require code to convert
3072 the transmitted address to Pmode, we do this here to ensure that possible
3073 preliminary conversions of the address have been emitted already. */
3074 if (all.function_result_decl)
3076 tree result = DECL_RESULT (current_function_decl);
3077 rtx addr = DECL_RTL (all.function_result_decl);
3080 if (DECL_BY_REFERENCE (result))
3084 addr = convert_memory_address (Pmode, addr);
3085 x = gen_rtx_MEM (DECL_MODE (result), addr);
3086 set_mem_attributes (x, result, 1);
3088 SET_DECL_RTL (result, x);
3091 /* We have aligned all the args, so add space for the pretend args. */
3092 current_function_pretend_args_size = all.pretend_args_size;
3093 all.stack_args_size.constant += all.extra_pretend_bytes;
3094 current_function_args_size = all.stack_args_size.constant;
3096 /* Adjust function incoming argument size for alignment and
3099 #ifdef REG_PARM_STACK_SPACE
3100 current_function_args_size = MAX (current_function_args_size,
3101 REG_PARM_STACK_SPACE (fndecl));
3104 current_function_args_size
3105 = ((current_function_args_size + STACK_BYTES - 1)
3106 / STACK_BYTES) * STACK_BYTES;
3108 #ifdef ARGS_GROW_DOWNWARD
3109 current_function_arg_offset_rtx
3110 = (all.stack_args_size.var == 0 ? GEN_INT (-all.stack_args_size.constant)
3111 : expand_expr (size_diffop (all.stack_args_size.var,
3112 size_int (-all.stack_args_size.constant)),
3113 NULL_RTX, VOIDmode, 0));
3115 current_function_arg_offset_rtx = ARGS_SIZE_RTX (all.stack_args_size);
3118 /* See how many bytes, if any, of its args a function should try to pop
3121 current_function_pops_args = RETURN_POPS_ARGS (fndecl, TREE_TYPE (fndecl),
3122 current_function_args_size);
3124 /* For stdarg.h function, save info about
3125 regs and stack space used by the named args. */
3127 current_function_args_info = all.args_so_far;
3129 /* Set the rtx used for the function return value. Put this in its
3130 own variable so any optimizers that need this information don't have
3131 to include tree.h. Do this here so it gets done when an inlined
3132 function gets output. */
3134 current_function_return_rtx
3135 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
3136 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
3138 /* If scalar return value was computed in a pseudo-reg, or was a named
3139 return value that got dumped to the stack, copy that to the hard
3141 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
3143 tree decl_result = DECL_RESULT (fndecl);
3144 rtx decl_rtl = DECL_RTL (decl_result);
3146 if (REG_P (decl_rtl)
3147 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
3148 : DECL_REGISTER (decl_result))
3152 #ifdef FUNCTION_OUTGOING_VALUE
3153 real_decl_rtl = FUNCTION_OUTGOING_VALUE (TREE_TYPE (decl_result),
3156 real_decl_rtl = FUNCTION_VALUE (TREE_TYPE (decl_result),
3159 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
3160 /* The delay slot scheduler assumes that current_function_return_rtx
3161 holds the hard register containing the return value, not a
3162 temporary pseudo. */
3163 current_function_return_rtx = real_decl_rtl;
3168 /* Indicate whether REGNO is an incoming argument to the current function
3169 that was promoted to a wider mode. If so, return the RTX for the
3170 register (to get its mode). PMODE and PUNSIGNEDP are set to the mode
3171 that REGNO is promoted from and whether the promotion was signed or
3175 promoted_input_arg (unsigned int regno, enum machine_mode *pmode, int *punsignedp)
3179 for (arg = DECL_ARGUMENTS (current_function_decl); arg;
3180 arg = TREE_CHAIN (arg))
3181 if (REG_P (DECL_INCOMING_RTL (arg))
3182 && REGNO (DECL_INCOMING_RTL (arg)) == regno
3183 && TYPE_MODE (DECL_ARG_TYPE (arg)) == TYPE_MODE (TREE_TYPE (arg)))
3185 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg));
3186 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (arg));
3188 mode = promote_mode (TREE_TYPE (arg), mode, &unsignedp, 1);
3189 if (mode == GET_MODE (DECL_INCOMING_RTL (arg))
3190 && mode != DECL_MODE (arg))
3192 *pmode = DECL_MODE (arg);
3193 *punsignedp = unsignedp;
3194 return DECL_INCOMING_RTL (arg);
3202 /* Compute the size and offset from the start of the stacked arguments for a
3203 parm passed in mode PASSED_MODE and with type TYPE.
3205 INITIAL_OFFSET_PTR points to the current offset into the stacked
3208 The starting offset and size for this parm are returned in
3209 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
3210 nonzero, the offset is that of stack slot, which is returned in
3211 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
3212 padding required from the initial offset ptr to the stack slot.
3214 IN_REGS is nonzero if the argument will be passed in registers. It will
3215 never be set if REG_PARM_STACK_SPACE is not defined.
3217 FNDECL is the function in which the argument was defined.
3219 There are two types of rounding that are done. The first, controlled by
3220 FUNCTION_ARG_BOUNDARY, forces the offset from the start of the argument
3221 list to be aligned to the specific boundary (in bits). This rounding
3222 affects the initial and starting offsets, but not the argument size.
3224 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
3225 optionally rounds the size of the parm to PARM_BOUNDARY. The
3226 initial offset is not affected by this rounding, while the size always
3227 is and the starting offset may be. */
3229 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
3230 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
3231 callers pass in the total size of args so far as
3232 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
3235 locate_and_pad_parm (enum machine_mode passed_mode, tree type, int in_regs,
3236 int partial, tree fndecl ATTRIBUTE_UNUSED,
3237 struct args_size *initial_offset_ptr,
3238 struct locate_and_pad_arg_data *locate)
3241 enum direction where_pad;
3243 int reg_parm_stack_space = 0;
3244 int part_size_in_regs;
3246 #ifdef REG_PARM_STACK_SPACE
3247 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
3249 /* If we have found a stack parm before we reach the end of the
3250 area reserved for registers, skip that area. */
3253 if (reg_parm_stack_space > 0)
3255 if (initial_offset_ptr->var)
3257 initial_offset_ptr->var
3258 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
3259 ssize_int (reg_parm_stack_space));
3260 initial_offset_ptr->constant = 0;
3262 else if (initial_offset_ptr->constant < reg_parm_stack_space)
3263 initial_offset_ptr->constant = reg_parm_stack_space;
3266 #endif /* REG_PARM_STACK_SPACE */
3268 part_size_in_regs = 0;
3269 if (reg_parm_stack_space == 0)
3270 part_size_in_regs = ((partial * UNITS_PER_WORD)
3271 / (PARM_BOUNDARY / BITS_PER_UNIT)
3272 * (PARM_BOUNDARY / BITS_PER_UNIT));
3275 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
3276 where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
3277 boundary = FUNCTION_ARG_BOUNDARY (passed_mode, type);
3278 locate->where_pad = where_pad;
3280 #ifdef ARGS_GROW_DOWNWARD
3281 locate->slot_offset.constant = -initial_offset_ptr->constant;
3282 if (initial_offset_ptr->var)
3283 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
3284 initial_offset_ptr->var);
3288 if (where_pad != none
3289 && (!host_integerp (sizetree, 1)
3290 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
3291 s2 = round_up (s2, PARM_BOUNDARY / BITS_PER_UNIT);
3292 SUB_PARM_SIZE (locate->slot_offset, s2);
3295 locate->slot_offset.constant += part_size_in_regs;
3298 #ifdef REG_PARM_STACK_SPACE
3299 || REG_PARM_STACK_SPACE (fndecl) > 0
3302 pad_to_arg_alignment (&locate->slot_offset, boundary,
3303 &locate->alignment_pad);
3305 locate->size.constant = (-initial_offset_ptr->constant
3306 - locate->slot_offset.constant);
3307 if (initial_offset_ptr->var)
3308 locate->size.var = size_binop (MINUS_EXPR,
3309 size_binop (MINUS_EXPR,
3311 initial_offset_ptr->var),
3312 locate->slot_offset.var);
3314 /* Pad_below needs the pre-rounded size to know how much to pad
3316 locate->offset = locate->slot_offset;
3317 if (where_pad == downward)
3318 pad_below (&locate->offset, passed_mode, sizetree);
3320 #else /* !ARGS_GROW_DOWNWARD */
3322 #ifdef REG_PARM_STACK_SPACE
3323 || REG_PARM_STACK_SPACE (fndecl) > 0
3326 pad_to_arg_alignment (initial_offset_ptr, boundary,
3327 &locate->alignment_pad);
3328 locate->slot_offset = *initial_offset_ptr;
3330 #ifdef PUSH_ROUNDING
3331 if (passed_mode != BLKmode)
3332 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
3335 /* Pad_below needs the pre-rounded size to know how much to pad below
3336 so this must be done before rounding up. */
3337 locate->offset = locate->slot_offset;
3338 if (where_pad == downward)
3339 pad_below (&locate->offset, passed_mode, sizetree);
3341 if (where_pad != none
3342 && (!host_integerp (sizetree, 1)
3343 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
3344 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3346 ADD_PARM_SIZE (locate->size, sizetree);
3348 locate->size.constant -= part_size_in_regs;
3349 #endif /* ARGS_GROW_DOWNWARD */
3352 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
3353 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
3356 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
3357 struct args_size *alignment_pad)
3359 tree save_var = NULL_TREE;
3360 HOST_WIDE_INT save_constant = 0;
3361 int boundary_in_bytes = boundary / BITS_PER_UNIT;
3362 HOST_WIDE_INT sp_offset = STACK_POINTER_OFFSET;
3364 #ifdef SPARC_STACK_BOUNDARY_HACK
3365 /* The sparc port has a bug. It sometimes claims a STACK_BOUNDARY
3366 higher than the real alignment of %sp. However, when it does this,
3367 the alignment of %sp+STACK_POINTER_OFFSET will be STACK_BOUNDARY.
3368 This is a temporary hack while the sparc port is fixed. */
3369 if (SPARC_STACK_BOUNDARY_HACK)
3373 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
3375 save_var = offset_ptr->var;
3376 save_constant = offset_ptr->constant;
3379 alignment_pad->var = NULL_TREE;
3380 alignment_pad->constant = 0;
3382 if (boundary > BITS_PER_UNIT)
3384 if (offset_ptr->var)
3386 tree sp_offset_tree = ssize_int (sp_offset);
3387 tree offset = size_binop (PLUS_EXPR,
3388 ARGS_SIZE_TREE (*offset_ptr),
3390 #ifdef ARGS_GROW_DOWNWARD
3391 tree rounded = round_down (offset, boundary / BITS_PER_UNIT);
3393 tree rounded = round_up (offset, boundary / BITS_PER_UNIT);
3396 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
3397 /* ARGS_SIZE_TREE includes constant term. */
3398 offset_ptr->constant = 0;
3399 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
3400 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
3405 offset_ptr->constant = -sp_offset +
3406 #ifdef ARGS_GROW_DOWNWARD
3407 FLOOR_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
3409 CEIL_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
3411 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
3412 alignment_pad->constant = offset_ptr->constant - save_constant;
3418 pad_below (struct args_size *offset_ptr, enum machine_mode passed_mode, tree sizetree)
3420 if (passed_mode != BLKmode)
3422 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
3423 offset_ptr->constant
3424 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
3425 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
3426 - GET_MODE_SIZE (passed_mode));
3430 if (TREE_CODE (sizetree) != INTEGER_CST
3431 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
3433 /* Round the size up to multiple of PARM_BOUNDARY bits. */
3434 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
3436 ADD_PARM_SIZE (*offset_ptr, s2);
3437 SUB_PARM_SIZE (*offset_ptr, sizetree);
3442 /* Walk the tree of blocks describing the binding levels within a function
3443 and warn about variables the might be killed by setjmp or vfork.
3444 This is done after calling flow_analysis and before global_alloc
3445 clobbers the pseudo-regs to hard regs. */
3448 setjmp_vars_warning (tree block)
3452 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
3454 if (TREE_CODE (decl) == VAR_DECL
3455 && DECL_RTL_SET_P (decl)
3456 && REG_P (DECL_RTL (decl))
3457 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
3458 warning ("%Jvariable '%D' might be clobbered by `longjmp' or `vfork'",
3462 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
3463 setjmp_vars_warning (sub);
3466 /* Do the appropriate part of setjmp_vars_warning
3467 but for arguments instead of local variables. */
3470 setjmp_args_warning (void)
3473 for (decl = DECL_ARGUMENTS (current_function_decl);
3474 decl; decl = TREE_CHAIN (decl))
3475 if (DECL_RTL (decl) != 0
3476 && REG_P (DECL_RTL (decl))
3477 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
3478 warning ("%Jargument '%D' might be clobbered by `longjmp' or `vfork'",
3483 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
3484 and create duplicate blocks. */
3485 /* ??? Need an option to either create block fragments or to create
3486 abstract origin duplicates of a source block. It really depends
3487 on what optimization has been performed. */
3490 reorder_blocks (void)
3492 tree block = DECL_INITIAL (current_function_decl);
3493 varray_type block_stack;
3495 if (block == NULL_TREE)
3498 VARRAY_TREE_INIT (block_stack, 10, "block_stack");
3500 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
3501 clear_block_marks (block);
3503 /* Prune the old trees away, so that they don't get in the way. */
3504 BLOCK_SUBBLOCKS (block) = NULL_TREE;
3505 BLOCK_CHAIN (block) = NULL_TREE;
3507 /* Recreate the block tree from the note nesting. */
3508 reorder_blocks_1 (get_insns (), block, &block_stack);
3509 BLOCK_SUBBLOCKS (block) = blocks_nreverse (BLOCK_SUBBLOCKS (block));
3511 /* Remove deleted blocks from the block fragment chains. */
3512 reorder_fix_fragments (block);
3515 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
3518 clear_block_marks (tree block)
3522 TREE_ASM_WRITTEN (block) = 0;
3523 clear_block_marks (BLOCK_SUBBLOCKS (block));
3524 block = BLOCK_CHAIN (block);
3529 reorder_blocks_1 (rtx insns, tree current_block, varray_type *p_block_stack)
3533 for (insn = insns; insn; insn = NEXT_INSN (insn))
3537 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
3539 tree block = NOTE_BLOCK (insn);
3541 /* If we have seen this block before, that means it now
3542 spans multiple address regions. Create a new fragment. */
3543 if (TREE_ASM_WRITTEN (block))
3545 tree new_block = copy_node (block);
3548 origin = (BLOCK_FRAGMENT_ORIGIN (block)
3549 ? BLOCK_FRAGMENT_ORIGIN (block)
3551 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
3552 BLOCK_FRAGMENT_CHAIN (new_block)
3553 = BLOCK_FRAGMENT_CHAIN (origin);
3554 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
3556 NOTE_BLOCK (insn) = new_block;
3560 BLOCK_SUBBLOCKS (block) = 0;
3561 TREE_ASM_WRITTEN (block) = 1;
3562 /* When there's only one block for the entire function,
3563 current_block == block and we mustn't do this, it
3564 will cause infinite recursion. */
3565 if (block != current_block)
3567 BLOCK_SUPERCONTEXT (block) = current_block;
3568 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
3569 BLOCK_SUBBLOCKS (current_block) = block;
3570 current_block = block;
3572 VARRAY_PUSH_TREE (*p_block_stack, block);
3574 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
3576 NOTE_BLOCK (insn) = VARRAY_TOP_TREE (*p_block_stack);
3577 VARRAY_POP (*p_block_stack);
3578 BLOCK_SUBBLOCKS (current_block)
3579 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block));
3580 current_block = BLOCK_SUPERCONTEXT (current_block);
3586 /* Rationalize BLOCK_FRAGMENT_ORIGIN. If an origin block no longer
3587 appears in the block tree, select one of the fragments to become
3588 the new origin block. */
3591 reorder_fix_fragments (tree block)
3595 tree dup_origin = BLOCK_FRAGMENT_ORIGIN (block);
3596 tree new_origin = NULL_TREE;
3600 if (! TREE_ASM_WRITTEN (dup_origin))
3602 new_origin = BLOCK_FRAGMENT_CHAIN (dup_origin);
3604 /* Find the first of the remaining fragments. There must
3605 be at least one -- the current block. */
3606 while (! TREE_ASM_WRITTEN (new_origin))
3607 new_origin = BLOCK_FRAGMENT_CHAIN (new_origin);
3608 BLOCK_FRAGMENT_ORIGIN (new_origin) = NULL_TREE;
3611 else if (! dup_origin)
3614 /* Re-root the rest of the fragments to the new origin. In the
3615 case that DUP_ORIGIN was null, that means BLOCK was the origin
3616 of a chain of fragments and we want to remove those fragments
3617 that didn't make it to the output. */
3620 tree *pp = &BLOCK_FRAGMENT_CHAIN (new_origin);
3625 if (TREE_ASM_WRITTEN (chain))
3627 BLOCK_FRAGMENT_ORIGIN (chain) = new_origin;
3629 pp = &BLOCK_FRAGMENT_CHAIN (chain);
3631 chain = BLOCK_FRAGMENT_CHAIN (chain);
3636 reorder_fix_fragments (BLOCK_SUBBLOCKS (block));
3637 block = BLOCK_CHAIN (block);
3641 /* Reverse the order of elements in the chain T of blocks,
3642 and return the new head of the chain (old last element). */
3645 blocks_nreverse (tree t)
3647 tree prev = 0, decl, next;
3648 for (decl = t; decl; decl = next)
3650 next = BLOCK_CHAIN (decl);
3651 BLOCK_CHAIN (decl) = prev;
3657 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
3658 non-NULL, list them all into VECTOR, in a depth-first preorder
3659 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
3663 all_blocks (tree block, tree *vector)
3669 TREE_ASM_WRITTEN (block) = 0;
3671 /* Record this block. */
3673 vector[n_blocks] = block;
3677 /* Record the subblocks, and their subblocks... */
3678 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
3679 vector ? vector + n_blocks : 0);
3680 block = BLOCK_CHAIN (block);
3686 /* Return a vector containing all the blocks rooted at BLOCK. The
3687 number of elements in the vector is stored in N_BLOCKS_P. The
3688 vector is dynamically allocated; it is the caller's responsibility
3689 to call `free' on the pointer returned. */
3692 get_block_vector (tree block, int *n_blocks_p)
3696 *n_blocks_p = all_blocks (block, NULL);
3697 block_vector = xmalloc (*n_blocks_p * sizeof (tree));
3698 all_blocks (block, block_vector);
3700 return block_vector;
3703 static GTY(()) int next_block_index = 2;
3705 /* Set BLOCK_NUMBER for all the blocks in FN. */
3708 number_blocks (tree fn)
3714 /* For SDB and XCOFF debugging output, we start numbering the blocks
3715 from 1 within each function, rather than keeping a running
3717 #if defined (SDB_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
3718 if (write_symbols == SDB_DEBUG || write_symbols == XCOFF_DEBUG)
3719 next_block_index = 1;
3722 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
3724 /* The top-level BLOCK isn't numbered at all. */
3725 for (i = 1; i < n_blocks; ++i)
3726 /* We number the blocks from two. */
3727 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
3729 free (block_vector);
3734 /* If VAR is present in a subblock of BLOCK, return the subblock. */
3737 debug_find_var_in_block_tree (tree var, tree block)
3741 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
3745 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
3747 tree ret = debug_find_var_in_block_tree (var, t);
3755 /* Allocate a function structure for FNDECL and set its contents
3759 allocate_struct_function (tree fndecl)
3762 tree fntype = fndecl ? TREE_TYPE (fndecl) : NULL_TREE;
3764 cfun = ggc_alloc_cleared (sizeof (struct function));
3766 cfun->stack_alignment_needed = STACK_BOUNDARY;
3767 cfun->preferred_stack_boundary = STACK_BOUNDARY;
3769 current_function_funcdef_no = funcdef_no++;
3771 cfun->function_frequency = FUNCTION_FREQUENCY_NORMAL;
3773 init_eh_for_function ();
3775 lang_hooks.function.init (cfun);
3776 if (init_machine_status)
3777 cfun->machine = (*init_machine_status) ();
3782 DECL_STRUCT_FUNCTION (fndecl) = cfun;
3783 cfun->decl = fndecl;
3785 result = DECL_RESULT (fndecl);
3786 if (aggregate_value_p (result, fndecl))
3788 #ifdef PCC_STATIC_STRUCT_RETURN
3789 current_function_returns_pcc_struct = 1;
3791 current_function_returns_struct = 1;
3794 current_function_returns_pointer = POINTER_TYPE_P (TREE_TYPE (result));
3796 current_function_stdarg
3798 && TYPE_ARG_TYPES (fntype) != 0
3799 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
3800 != void_type_node));
3803 /* Reset cfun, and other non-struct-function variables to defaults as
3804 appropriate for emitting rtl at the start of a function. */
3807 prepare_function_start (tree fndecl)
3809 if (fndecl && DECL_STRUCT_FUNCTION (fndecl))
3810 cfun = DECL_STRUCT_FUNCTION (fndecl);
3812 allocate_struct_function (fndecl);
3814 init_varasm_status (cfun);
3817 cse_not_expected = ! optimize;
3819 /* Caller save not needed yet. */
3820 caller_save_needed = 0;
3822 /* We haven't done register allocation yet. */
3825 /* Indicate that we have not instantiated virtual registers yet. */
3826 virtuals_instantiated = 0;
3828 /* Indicate that we want CONCATs now. */
3829 generating_concat_p = 1;
3831 /* Indicate we have no need of a frame pointer yet. */
3832 frame_pointer_needed = 0;
3835 /* Initialize the rtl expansion mechanism so that we can do simple things
3836 like generate sequences. This is used to provide a context during global
3837 initialization of some passes. */
3839 init_dummy_function_start (void)
3841 prepare_function_start (NULL);
3844 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
3845 and initialize static variables for generating RTL for the statements
3849 init_function_start (tree subr)
3851 prepare_function_start (subr);
3853 /* Prevent ever trying to delete the first instruction of a
3854 function. Also tell final how to output a linenum before the
3855 function prologue. Note linenums could be missing, e.g. when
3856 compiling a Java .class file. */
3857 if (! DECL_IS_BUILTIN (subr))
3858 emit_line_note (DECL_SOURCE_LOCATION (subr));
3860 /* Make sure first insn is a note even if we don't want linenums.
3861 This makes sure the first insn will never be deleted.
3862 Also, final expects a note to appear there. */
3863 emit_note (NOTE_INSN_DELETED);
3865 /* Warn if this value is an aggregate type,
3866 regardless of which calling convention we are using for it. */
3867 if (warn_aggregate_return
3868 && AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
3869 warning ("function returns an aggregate");
3872 /* Make sure all values used by the optimization passes have sane
3875 init_function_for_compilation (void)
3879 /* No prologue/epilogue insns yet. */
3880 VARRAY_GROW (prologue, 0);
3881 VARRAY_GROW (epilogue, 0);
3882 VARRAY_GROW (sibcall_epilogue, 0);
3885 /* Expand a call to __main at the beginning of a possible main function. */
3887 #if defined(INIT_SECTION_ASM_OP) && !defined(INVOKE__main)
3888 #undef HAS_INIT_SECTION
3889 #define HAS_INIT_SECTION
3893 expand_main_function (void)
3895 #ifdef FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN
3896 if (FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN)
3898 int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
3902 /* Forcibly align the stack. */
3903 #ifdef STACK_GROWS_DOWNWARD
3904 tmp = expand_simple_binop (Pmode, AND, stack_pointer_rtx, GEN_INT(-align),
3905 stack_pointer_rtx, 1, OPTAB_WIDEN);
3907 tmp = expand_simple_binop (Pmode, PLUS, stack_pointer_rtx,
3908 GEN_INT (align - 1), NULL_RTX, 1, OPTAB_WIDEN);
3909 tmp = expand_simple_binop (Pmode, AND, tmp, GEN_INT (-align),
3910 stack_pointer_rtx, 1, OPTAB_WIDEN);
3912 if (tmp != stack_pointer_rtx)
3913 emit_move_insn (stack_pointer_rtx, tmp);
3915 /* Enlist allocate_dynamic_stack_space to pick up the pieces. */
3916 tmp = force_reg (Pmode, const0_rtx);
3917 allocate_dynamic_stack_space (tmp, NULL_RTX, BIGGEST_ALIGNMENT);
3921 for (tmp = get_last_insn (); tmp; tmp = PREV_INSN (tmp))
3922 if (NOTE_P (tmp) && NOTE_LINE_NUMBER (tmp) == NOTE_INSN_FUNCTION_BEG)
3925 emit_insn_before (seq, tmp);
3931 #ifndef HAS_INIT_SECTION
3932 emit_library_call (init_one_libfunc (NAME__MAIN), LCT_NORMAL, VOIDmode, 0);
3936 /* The PENDING_SIZES represent the sizes of variable-sized types.
3937 Create RTL for the various sizes now (using temporary variables),
3938 so that we can refer to the sizes from the RTL we are generating
3939 for the current function. The PENDING_SIZES are a TREE_LIST. The
3940 TREE_VALUE of each node is a SAVE_EXPR. */
3943 expand_pending_sizes (tree pending_sizes)
3947 /* Evaluate now the sizes of any types declared among the arguments. */
3948 for (tem = pending_sizes; tem; tem = TREE_CHAIN (tem))
3949 expand_expr (TREE_VALUE (tem), const0_rtx, VOIDmode, 0);
3952 /* Start the RTL for a new function, and set variables used for
3954 SUBR is the FUNCTION_DECL node.
3955 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
3956 the function's parameters, which must be run at any return statement. */
3959 expand_function_start (tree subr)
3961 /* Make sure volatile mem refs aren't considered
3962 valid operands of arithmetic insns. */
3963 init_recog_no_volatile ();
3965 current_function_profile
3967 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
3969 current_function_limit_stack
3970 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
3972 /* Make the label for return statements to jump to. Do not special
3973 case machines with special return instructions -- they will be
3974 handled later during jump, ifcvt, or epilogue creation. */
3975 return_label = gen_label_rtx ();
3977 /* Initialize rtx used to return the value. */
3978 /* Do this before assign_parms so that we copy the struct value address
3979 before any library calls that assign parms might generate. */
3981 /* Decide whether to return the value in memory or in a register. */
3982 if (aggregate_value_p (DECL_RESULT (subr), subr))
3984 /* Returning something that won't go in a register. */
3985 rtx value_address = 0;
3987 #ifdef PCC_STATIC_STRUCT_RETURN
3988 if (current_function_returns_pcc_struct)
3990 int size = int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr)));
3991 value_address = assemble_static_space (size);
3996 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 1);
3997 /* Expect to be passed the address of a place to store the value.
3998 If it is passed as an argument, assign_parms will take care of
4002 value_address = gen_reg_rtx (Pmode);
4003 emit_move_insn (value_address, sv);
4008 rtx x = value_address;
4009 if (!DECL_BY_REFERENCE (DECL_RESULT (subr)))
4011 x = gen_rtx_MEM (DECL_MODE (DECL_RESULT (subr)), x);
4012 set_mem_attributes (x, DECL_RESULT (subr), 1);
4014 SET_DECL_RTL (DECL_RESULT (subr), x);
4017 else if (DECL_MODE (DECL_RESULT (subr)) == VOIDmode)
4018 /* If return mode is void, this decl rtl should not be used. */
4019 SET_DECL_RTL (DECL_RESULT (subr), NULL_RTX);
4022 /* Compute the return values into a pseudo reg, which we will copy
4023 into the true return register after the cleanups are done. */
4025 /* In order to figure out what mode to use for the pseudo, we
4026 figure out what the mode of the eventual return register will
4027 actually be, and use that. */
4029 = hard_function_value (TREE_TYPE (DECL_RESULT (subr)),
4032 /* Structures that are returned in registers are not aggregate_value_p,
4033 so we may see a PARALLEL or a REG. */
4034 if (REG_P (hard_reg))
4035 SET_DECL_RTL (DECL_RESULT (subr), gen_reg_rtx (GET_MODE (hard_reg)));
4036 else if (GET_CODE (hard_reg) == PARALLEL)
4037 SET_DECL_RTL (DECL_RESULT (subr), gen_group_rtx (hard_reg));
4041 /* Set DECL_REGISTER flag so that expand_function_end will copy the
4042 result to the real return register(s). */
4043 DECL_REGISTER (DECL_RESULT (subr)) = 1;
4046 /* Initialize rtx for parameters and local variables.
4047 In some cases this requires emitting insns. */
4048 assign_parms (subr);
4050 /* If function gets a static chain arg, store it. */
4051 if (cfun->static_chain_decl)
4053 tree parm = cfun->static_chain_decl;
4054 rtx local = gen_reg_rtx (Pmode);
4056 set_decl_incoming_rtl (parm, static_chain_incoming_rtx);
4057 SET_DECL_RTL (parm, local);
4058 maybe_set_unchanging (local, parm);
4059 mark_reg_pointer (local, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
4061 emit_move_insn (local, static_chain_incoming_rtx);
4064 /* If the function receives a non-local goto, then store the
4065 bits we need to restore the frame pointer. */
4066 if (cfun->nonlocal_goto_save_area)
4071 /* ??? We need to do this save early. Unfortunately here is
4072 before the frame variable gets declared. Help out... */
4073 expand_var (TREE_OPERAND (cfun->nonlocal_goto_save_area, 0));
4075 t_save = build4 (ARRAY_REF, ptr_type_node,
4076 cfun->nonlocal_goto_save_area,
4077 integer_zero_node, NULL_TREE, NULL_TREE);
4078 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
4079 r_save = convert_memory_address (Pmode, r_save);
4081 emit_move_insn (r_save, virtual_stack_vars_rtx);
4082 update_nonlocal_goto_save_area ();
4085 /* The following was moved from init_function_start.
4086 The move is supposed to make sdb output more accurate. */
4087 /* Indicate the beginning of the function body,
4088 as opposed to parm setup. */
4089 emit_note (NOTE_INSN_FUNCTION_BEG);
4091 if (!NOTE_P (get_last_insn ()))
4092 emit_note (NOTE_INSN_DELETED);
4093 parm_birth_insn = get_last_insn ();
4095 if (current_function_profile)
4098 PROFILE_HOOK (current_function_funcdef_no);
4102 /* After the display initializations is where the tail-recursion label
4103 should go, if we end up needing one. Ensure we have a NOTE here
4104 since some things (like trampolines) get placed before this. */
4105 tail_recursion_reentry = emit_note (NOTE_INSN_DELETED);
4107 /* Evaluate now the sizes of any types declared among the arguments. */
4108 expand_pending_sizes (nreverse (get_pending_sizes ()));
4110 /* Make sure there is a line number after the function entry setup code. */
4111 force_next_line_note ();
4114 /* Undo the effects of init_dummy_function_start. */
4116 expand_dummy_function_end (void)
4118 /* End any sequences that failed to be closed due to syntax errors. */
4119 while (in_sequence_p ())
4122 /* Outside function body, can't compute type's actual size
4123 until next function's body starts. */
4125 free_after_parsing (cfun);
4126 free_after_compilation (cfun);
4130 /* Call DOIT for each hard register used as a return value from
4131 the current function. */
4134 diddle_return_value (void (*doit) (rtx, void *), void *arg)
4136 rtx outgoing = current_function_return_rtx;
4141 if (REG_P (outgoing))
4142 (*doit) (outgoing, arg);
4143 else if (GET_CODE (outgoing) == PARALLEL)
4147 for (i = 0; i < XVECLEN (outgoing, 0); i++)
4149 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
4151 if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
4158 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
4160 emit_insn (gen_rtx_CLOBBER (VOIDmode, reg));
4164 clobber_return_register (void)
4166 diddle_return_value (do_clobber_return_reg, NULL);
4168 /* In case we do use pseudo to return value, clobber it too. */
4169 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
4171 tree decl_result = DECL_RESULT (current_function_decl);
4172 rtx decl_rtl = DECL_RTL (decl_result);
4173 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
4175 do_clobber_return_reg (decl_rtl, NULL);
4181 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
4183 emit_insn (gen_rtx_USE (VOIDmode, reg));
4187 use_return_register (void)
4189 diddle_return_value (do_use_return_reg, NULL);
4192 /* Possibly warn about unused parameters. */
4194 do_warn_unused_parameter (tree fn)
4198 for (decl = DECL_ARGUMENTS (fn);
4199 decl; decl = TREE_CHAIN (decl))
4200 if (!TREE_USED (decl) && TREE_CODE (decl) == PARM_DECL
4201 && DECL_NAME (decl) && !DECL_ARTIFICIAL (decl))
4202 warning ("%Junused parameter '%D'", decl, decl);
4205 static GTY(()) rtx initial_trampoline;
4207 /* Generate RTL for the end of the current function. */
4210 expand_function_end (void)
4214 /* If arg_pointer_save_area was referenced only from a nested
4215 function, we will not have initialized it yet. Do that now. */
4216 if (arg_pointer_save_area && ! cfun->arg_pointer_save_area_init)
4217 get_arg_pointer_save_area (cfun);
4219 /* If we are doing stack checking and this function makes calls,
4220 do a stack probe at the start of the function to ensure we have enough
4221 space for another stack frame. */
4222 if (flag_stack_check && ! STACK_CHECK_BUILTIN)
4226 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
4230 probe_stack_range (STACK_CHECK_PROTECT,
4231 GEN_INT (STACK_CHECK_MAX_FRAME_SIZE));
4234 emit_insn_before (seq, tail_recursion_reentry);
4239 /* Possibly warn about unused parameters.
4240 When frontend does unit-at-a-time, the warning is already
4241 issued at finalization time. */
4242 if (warn_unused_parameter
4243 && !lang_hooks.callgraph.expand_function)
4244 do_warn_unused_parameter (current_function_decl);
4246 /* End any sequences that failed to be closed due to syntax errors. */
4247 while (in_sequence_p ())
4250 clear_pending_stack_adjust ();
4251 do_pending_stack_adjust ();
4253 /* @@@ This is a kludge. We want to ensure that instructions that
4254 may trap are not moved into the epilogue by scheduling, because
4255 we don't always emit unwind information for the epilogue.
4256 However, not all machine descriptions define a blockage insn, so
4257 emit an ASM_INPUT to act as one. */
4258 if (flag_non_call_exceptions)
4259 emit_insn (gen_rtx_ASM_INPUT (VOIDmode, ""));
4261 /* Mark the end of the function body.
4262 If control reaches this insn, the function can drop through
4263 without returning a value. */
4264 emit_note (NOTE_INSN_FUNCTION_END);
4266 /* Must mark the last line number note in the function, so that the test
4267 coverage code can avoid counting the last line twice. This just tells
4268 the code to ignore the immediately following line note, since there
4269 already exists a copy of this note somewhere above. This line number
4270 note is still needed for debugging though, so we can't delete it. */
4271 if (flag_test_coverage)
4272 emit_note (NOTE_INSN_REPEATED_LINE_NUMBER);
4274 /* Output a linenumber for the end of the function.
4275 SDB depends on this. */
4276 force_next_line_note ();
4277 emit_line_note (input_location);
4279 /* Before the return label (if any), clobber the return
4280 registers so that they are not propagated live to the rest of
4281 the function. This can only happen with functions that drop
4282 through; if there had been a return statement, there would
4283 have either been a return rtx, or a jump to the return label.
4285 We delay actual code generation after the current_function_value_rtx
4287 clobber_after = get_last_insn ();
4289 /* Output the label for the actual return from the function,
4290 if one is expected. This happens either because a function epilogue
4291 is used instead of a return instruction, or because a return was done
4292 with a goto in order to run local cleanups, or because of pcc-style
4293 structure returning. */
4295 emit_label (return_label);
4297 /* Let except.c know where it should emit the call to unregister
4298 the function context for sjlj exceptions. */
4299 if (flag_exceptions && USING_SJLJ_EXCEPTIONS)
4300 sjlj_emit_function_exit_after (get_last_insn ());
4302 /* If we had calls to alloca, and this machine needs
4303 an accurate stack pointer to exit the function,
4304 insert some code to save and restore the stack pointer. */
4305 if (! EXIT_IGNORE_STACK
4306 && current_function_calls_alloca)
4310 emit_stack_save (SAVE_FUNCTION, &tem, parm_birth_insn);
4311 emit_stack_restore (SAVE_FUNCTION, tem, NULL_RTX);
4314 /* If scalar return value was computed in a pseudo-reg, or was a named
4315 return value that got dumped to the stack, copy that to the hard
4317 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
4319 tree decl_result = DECL_RESULT (current_function_decl);
4320 rtx decl_rtl = DECL_RTL (decl_result);
4322 if (REG_P (decl_rtl)
4323 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
4324 : DECL_REGISTER (decl_result))
4326 rtx real_decl_rtl = current_function_return_rtx;
4328 /* This should be set in assign_parms. */
4329 if (! REG_FUNCTION_VALUE_P (real_decl_rtl))
4332 /* If this is a BLKmode structure being returned in registers,
4333 then use the mode computed in expand_return. Note that if
4334 decl_rtl is memory, then its mode may have been changed,
4335 but that current_function_return_rtx has not. */
4336 if (GET_MODE (real_decl_rtl) == BLKmode)
4337 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
4339 /* If a named return value dumped decl_return to memory, then
4340 we may need to re-do the PROMOTE_MODE signed/unsigned
4342 if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
4344 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
4346 if (targetm.calls.promote_function_return (TREE_TYPE (current_function_decl)))
4347 promote_mode (TREE_TYPE (decl_result), GET_MODE (decl_rtl),
4350 convert_move (real_decl_rtl, decl_rtl, unsignedp);
4352 else if (GET_CODE (real_decl_rtl) == PARALLEL)
4354 /* If expand_function_start has created a PARALLEL for decl_rtl,
4355 move the result to the real return registers. Otherwise, do
4356 a group load from decl_rtl for a named return. */
4357 if (GET_CODE (decl_rtl) == PARALLEL)
4358 emit_group_move (real_decl_rtl, decl_rtl);
4360 emit_group_load (real_decl_rtl, decl_rtl,
4361 TREE_TYPE (decl_result),
4362 int_size_in_bytes (TREE_TYPE (decl_result)));
4365 emit_move_insn (real_decl_rtl, decl_rtl);
4369 /* If returning a structure, arrange to return the address of the value
4370 in a place where debuggers expect to find it.
4372 If returning a structure PCC style,
4373 the caller also depends on this value.
4374 And current_function_returns_pcc_struct is not necessarily set. */
4375 if (current_function_returns_struct
4376 || current_function_returns_pcc_struct)
4378 rtx value_address = DECL_RTL (DECL_RESULT (current_function_decl));
4379 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
4382 if (DECL_BY_REFERENCE (DECL_RESULT (current_function_decl)))
4383 type = TREE_TYPE (type);
4385 value_address = XEXP (value_address, 0);
4387 #ifdef FUNCTION_OUTGOING_VALUE
4388 outgoing = FUNCTION_OUTGOING_VALUE (build_pointer_type (type),
4389 current_function_decl);
4391 outgoing = FUNCTION_VALUE (build_pointer_type (type),
4392 current_function_decl);
4395 /* Mark this as a function return value so integrate will delete the
4396 assignment and USE below when inlining this function. */
4397 REG_FUNCTION_VALUE_P (outgoing) = 1;
4399 /* The address may be ptr_mode and OUTGOING may be Pmode. */
4400 value_address = convert_memory_address (GET_MODE (outgoing),
4403 emit_move_insn (outgoing, value_address);
4405 /* Show return register used to hold result (in this case the address
4407 current_function_return_rtx = outgoing;
4410 /* If this is an implementation of throw, do what's necessary to
4411 communicate between __builtin_eh_return and the epilogue. */
4412 expand_eh_return ();
4414 /* Emit the actual code to clobber return register. */
4419 clobber_return_register ();
4423 after = emit_insn_after (seq, clobber_after);
4426 /* Output the label for the naked return from the function, if one is
4427 expected. This is currently used only by __builtin_return. */
4428 if (naked_return_label)
4429 emit_label (naked_return_label);
4431 /* ??? This should no longer be necessary since stupid is no longer with
4432 us, but there are some parts of the compiler (eg reload_combine, and
4433 sh mach_dep_reorg) that still try and compute their own lifetime info
4434 instead of using the general framework. */
4435 use_return_register ();
4439 get_arg_pointer_save_area (struct function *f)
4441 rtx ret = f->x_arg_pointer_save_area;
4445 ret = assign_stack_local_1 (Pmode, GET_MODE_SIZE (Pmode), 0, f);
4446 f->x_arg_pointer_save_area = ret;
4449 if (f == cfun && ! f->arg_pointer_save_area_init)
4453 /* Save the arg pointer at the beginning of the function. The
4454 generated stack slot may not be a valid memory address, so we
4455 have to check it and fix it if necessary. */
4457 emit_move_insn (validize_mem (ret), virtual_incoming_args_rtx);
4461 push_topmost_sequence ();
4462 emit_insn_after (seq, get_insns ());
4463 pop_topmost_sequence ();
4469 /* Extend a vector that records the INSN_UIDs of INSNS
4470 (a list of one or more insns). */
4473 record_insns (rtx insns, varray_type *vecp)
4480 while (tmp != NULL_RTX)
4483 tmp = NEXT_INSN (tmp);
4486 i = VARRAY_SIZE (*vecp);
4487 VARRAY_GROW (*vecp, i + len);
4489 while (tmp != NULL_RTX)
4491 VARRAY_INT (*vecp, i) = INSN_UID (tmp);
4493 tmp = NEXT_INSN (tmp);
4497 /* Set the locator of the insn chain starting at INSN to LOC. */
4499 set_insn_locators (rtx insn, int loc)
4501 while (insn != NULL_RTX)
4504 INSN_LOCATOR (insn) = loc;
4505 insn = NEXT_INSN (insn);
4509 /* Determine how many INSN_UIDs in VEC are part of INSN. Because we can
4510 be running after reorg, SEQUENCE rtl is possible. */
4513 contains (rtx insn, varray_type vec)
4517 if (NONJUMP_INSN_P (insn)
4518 && GET_CODE (PATTERN (insn)) == SEQUENCE)
4521 for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
4522 for (j = VARRAY_SIZE (vec) - 1; j >= 0; --j)
4523 if (INSN_UID (XVECEXP (PATTERN (insn), 0, i)) == VARRAY_INT (vec, j))
4529 for (j = VARRAY_SIZE (vec) - 1; j >= 0; --j)
4530 if (INSN_UID (insn) == VARRAY_INT (vec, j))
4537 prologue_epilogue_contains (rtx insn)
4539 if (contains (insn, prologue))
4541 if (contains (insn, epilogue))
4547 sibcall_epilogue_contains (rtx insn)
4549 if (sibcall_epilogue)
4550 return contains (insn, sibcall_epilogue);
4555 /* Insert gen_return at the end of block BB. This also means updating
4556 block_for_insn appropriately. */
4559 emit_return_into_block (basic_block bb, rtx line_note)
4561 emit_jump_insn_after (gen_return (), BB_END (bb));
4563 emit_note_copy_after (line_note, PREV_INSN (BB_END (bb)));
4565 #endif /* HAVE_return */
4567 #if defined(HAVE_epilogue) && defined(INCOMING_RETURN_ADDR_RTX)
4569 /* These functions convert the epilogue into a variant that does not modify the
4570 stack pointer. This is used in cases where a function returns an object
4571 whose size is not known until it is computed. The called function leaves the
4572 object on the stack, leaves the stack depressed, and returns a pointer to
4575 What we need to do is track all modifications and references to the stack
4576 pointer, deleting the modifications and changing the references to point to
4577 the location the stack pointer would have pointed to had the modifications
4580 These functions need to be portable so we need to make as few assumptions
4581 about the epilogue as we can. However, the epilogue basically contains
4582 three things: instructions to reset the stack pointer, instructions to
4583 reload registers, possibly including the frame pointer, and an
4584 instruction to return to the caller.
4586 If we can't be sure of what a relevant epilogue insn is doing, we abort.
4587 We also make no attempt to validate the insns we make since if they are
4588 invalid, we probably can't do anything valid. The intent is that these
4589 routines get "smarter" as more and more machines start to use them and
4590 they try operating on different epilogues.
4592 We use the following structure to track what the part of the epilogue that
4593 we've already processed has done. We keep two copies of the SP equivalence,
4594 one for use during the insn we are processing and one for use in the next
4595 insn. The difference is because one part of a PARALLEL may adjust SP
4596 and the other may use it. */
4600 rtx sp_equiv_reg; /* REG that SP is set from, perhaps SP. */
4601 HOST_WIDE_INT sp_offset; /* Offset from SP_EQUIV_REG of present SP. */
4602 rtx new_sp_equiv_reg; /* REG to be used at end of insn. */
4603 HOST_WIDE_INT new_sp_offset; /* Offset to be used at end of insn. */
4604 rtx equiv_reg_src; /* If nonzero, the value that SP_EQUIV_REG
4605 should be set to once we no longer need
4607 rtx const_equiv[FIRST_PSEUDO_REGISTER]; /* Any known constant equivalences
4611 static void handle_epilogue_set (rtx, struct epi_info *);
4612 static void update_epilogue_consts (rtx, rtx, void *);
4613 static void emit_equiv_load (struct epi_info *);
4615 /* Modify INSN, a list of one or more insns that is part of the epilogue, to
4616 no modifications to the stack pointer. Return the new list of insns. */
4619 keep_stack_depressed (rtx insns)
4622 struct epi_info info;
4625 /* If the epilogue is just a single instruction, it must be OK as is. */
4626 if (NEXT_INSN (insns) == NULL_RTX)
4629 /* Otherwise, start a sequence, initialize the information we have, and
4630 process all the insns we were given. */
4633 info.sp_equiv_reg = stack_pointer_rtx;
4635 info.equiv_reg_src = 0;
4637 for (j = 0; j < FIRST_PSEUDO_REGISTER; j++)
4638 info.const_equiv[j] = 0;
4642 while (insn != NULL_RTX)
4644 next = NEXT_INSN (insn);
4653 /* If this insn references the register that SP is equivalent to and
4654 we have a pending load to that register, we must force out the load
4655 first and then indicate we no longer know what SP's equivalent is. */
4656 if (info.equiv_reg_src != 0
4657 && reg_referenced_p (info.sp_equiv_reg, PATTERN (insn)))
4659 emit_equiv_load (&info);
4660 info.sp_equiv_reg = 0;
4663 info.new_sp_equiv_reg = info.sp_equiv_reg;
4664 info.new_sp_offset = info.sp_offset;
4666 /* If this is a (RETURN) and the return address is on the stack,
4667 update the address and change to an indirect jump. */
4668 if (GET_CODE (PATTERN (insn)) == RETURN
4669 || (GET_CODE (PATTERN (insn)) == PARALLEL
4670 && GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == RETURN))
4672 rtx retaddr = INCOMING_RETURN_ADDR_RTX;
4674 HOST_WIDE_INT offset = 0;
4675 rtx jump_insn, jump_set;
4677 /* If the return address is in a register, we can emit the insn
4678 unchanged. Otherwise, it must be a MEM and we see what the
4679 base register and offset are. In any case, we have to emit any
4680 pending load to the equivalent reg of SP, if any. */
4681 if (REG_P (retaddr))
4683 emit_equiv_load (&info);
4688 else if (MEM_P (retaddr)
4689 && REG_P (XEXP (retaddr, 0)))
4690 base = gen_rtx_REG (Pmode, REGNO (XEXP (retaddr, 0))), offset = 0;
4691 else if (MEM_P (retaddr)
4692 && GET_CODE (XEXP (retaddr, 0)) == PLUS
4693 && REG_P (XEXP (XEXP (retaddr, 0), 0))
4694 && GET_CODE (XEXP (XEXP (retaddr, 0), 1)) == CONST_INT)
4696 base = gen_rtx_REG (Pmode, REGNO (XEXP (XEXP (retaddr, 0), 0)));
4697 offset = INTVAL (XEXP (XEXP (retaddr, 0), 1));
4702 /* If the base of the location containing the return pointer
4703 is SP, we must update it with the replacement address. Otherwise,
4704 just build the necessary MEM. */
4705 retaddr = plus_constant (base, offset);
4706 if (base == stack_pointer_rtx)
4707 retaddr = simplify_replace_rtx (retaddr, stack_pointer_rtx,
4708 plus_constant (info.sp_equiv_reg,
4711 retaddr = gen_rtx_MEM (Pmode, retaddr);
4713 /* If there is a pending load to the equivalent register for SP
4714 and we reference that register, we must load our address into
4715 a scratch register and then do that load. */
4716 if (info.equiv_reg_src
4717 && reg_overlap_mentioned_p (info.equiv_reg_src, retaddr))
4722 for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
4723 if (HARD_REGNO_MODE_OK (regno, Pmode)
4724 && !fixed_regs[regno]
4725 && TEST_HARD_REG_BIT (regs_invalidated_by_call, regno)
4726 && !REGNO_REG_SET_P (EXIT_BLOCK_PTR->global_live_at_start,
4728 && !refers_to_regno_p (regno,
4729 regno + hard_regno_nregs[regno]
4731 info.equiv_reg_src, NULL)
4732 && info.const_equiv[regno] == 0)
4735 if (regno == FIRST_PSEUDO_REGISTER)
4738 reg = gen_rtx_REG (Pmode, regno);
4739 emit_move_insn (reg, retaddr);
4743 emit_equiv_load (&info);
4744 jump_insn = emit_jump_insn (gen_indirect_jump (retaddr));
4746 /* Show the SET in the above insn is a RETURN. */
4747 jump_set = single_set (jump_insn);
4751 SET_IS_RETURN_P (jump_set) = 1;
4754 /* If SP is not mentioned in the pattern and its equivalent register, if
4755 any, is not modified, just emit it. Otherwise, if neither is set,
4756 replace the reference to SP and emit the insn. If none of those are
4757 true, handle each SET individually. */
4758 else if (!reg_mentioned_p (stack_pointer_rtx, PATTERN (insn))
4759 && (info.sp_equiv_reg == stack_pointer_rtx
4760 || !reg_set_p (info.sp_equiv_reg, insn)))
4762 else if (! reg_set_p (stack_pointer_rtx, insn)
4763 && (info.sp_equiv_reg == stack_pointer_rtx
4764 || !reg_set_p (info.sp_equiv_reg, insn)))
4766 if (! validate_replace_rtx (stack_pointer_rtx,
4767 plus_constant (info.sp_equiv_reg,
4774 else if (GET_CODE (PATTERN (insn)) == SET)
4775 handle_epilogue_set (PATTERN (insn), &info);
4776 else if (GET_CODE (PATTERN (insn)) == PARALLEL)
4778 for (j = 0; j < XVECLEN (PATTERN (insn), 0); j++)
4779 if (GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == SET)
4780 handle_epilogue_set (XVECEXP (PATTERN (insn), 0, j), &info);
4785 info.sp_equiv_reg = info.new_sp_equiv_reg;
4786 info.sp_offset = info.new_sp_offset;
4788 /* Now update any constants this insn sets. */
4789 note_stores (PATTERN (insn), update_epilogue_consts, &info);
4793 insns = get_insns ();
4798 /* SET is a SET from an insn in the epilogue. P is a pointer to the epi_info
4799 structure that contains information about what we've seen so far. We
4800 process this SET by either updating that data or by emitting one or
4804 handle_epilogue_set (rtx set, struct epi_info *p)
4806 /* First handle the case where we are setting SP. Record what it is being
4807 set from. If unknown, abort. */
4808 if (reg_set_p (stack_pointer_rtx, set))
4810 if (SET_DEST (set) != stack_pointer_rtx)
4813 if (GET_CODE (SET_SRC (set)) == PLUS)
4815 p->new_sp_equiv_reg = XEXP (SET_SRC (set), 0);
4816 if (GET_CODE (XEXP (SET_SRC (set), 1)) == CONST_INT)
4817 p->new_sp_offset = INTVAL (XEXP (SET_SRC (set), 1));
4818 else if (REG_P (XEXP (SET_SRC (set), 1))
4819 && REGNO (XEXP (SET_SRC (set), 1)) < FIRST_PSEUDO_REGISTER
4820 && p->const_equiv[REGNO (XEXP (SET_SRC (set), 1))] != 0)
4822 = INTVAL (p->const_equiv[REGNO (XEXP (SET_SRC (set), 1))]);
4827 p->new_sp_equiv_reg = SET_SRC (set), p->new_sp_offset = 0;
4829 /* If we are adjusting SP, we adjust from the old data. */
4830 if (p->new_sp_equiv_reg == stack_pointer_rtx)
4832 p->new_sp_equiv_reg = p->sp_equiv_reg;
4833 p->new_sp_offset += p->sp_offset;
4836 if (p->new_sp_equiv_reg == 0 || !REG_P (p->new_sp_equiv_reg))
4842 /* Next handle the case where we are setting SP's equivalent register.
4843 If we already have a value to set it to, abort. We could update, but
4844 there seems little point in handling that case. Note that we have
4845 to allow for the case where we are setting the register set in
4846 the previous part of a PARALLEL inside a single insn. But use the
4847 old offset for any updates within this insn. We must allow for the case
4848 where the register is being set in a different (usually wider) mode than
4850 else if (p->new_sp_equiv_reg != 0 && reg_set_p (p->new_sp_equiv_reg, set))
4852 if (p->equiv_reg_src != 0
4853 || !REG_P (p->new_sp_equiv_reg)
4854 || !REG_P (SET_DEST (set))
4855 || GET_MODE_BITSIZE (GET_MODE (SET_DEST (set))) > BITS_PER_WORD
4856 || REGNO (p->new_sp_equiv_reg) != REGNO (SET_DEST (set)))
4860 = simplify_replace_rtx (SET_SRC (set), stack_pointer_rtx,
4861 plus_constant (p->sp_equiv_reg,
4865 /* Otherwise, replace any references to SP in the insn to its new value
4866 and emit the insn. */
4869 SET_SRC (set) = simplify_replace_rtx (SET_SRC (set), stack_pointer_rtx,
4870 plus_constant (p->sp_equiv_reg,
4872 SET_DEST (set) = simplify_replace_rtx (SET_DEST (set), stack_pointer_rtx,
4873 plus_constant (p->sp_equiv_reg,
4879 /* Update the tracking information for registers set to constants. */
4882 update_epilogue_consts (rtx dest, rtx x, void *data)
4884 struct epi_info *p = (struct epi_info *) data;
4887 if (!REG_P (dest) || REGNO (dest) >= FIRST_PSEUDO_REGISTER)
4890 /* If we are either clobbering a register or doing a partial set,
4891 show we don't know the value. */
4892 else if (GET_CODE (x) == CLOBBER || ! rtx_equal_p (dest, SET_DEST (x)))
4893 p->const_equiv[REGNO (dest)] = 0;
4895 /* If we are setting it to a constant, record that constant. */
4896 else if (GET_CODE (SET_SRC (x)) == CONST_INT)
4897 p->const_equiv[REGNO (dest)] = SET_SRC (x);
4899 /* If this is a binary operation between a register we have been tracking
4900 and a constant, see if we can compute a new constant value. */
4901 else if (ARITHMETIC_P (SET_SRC (x))
4902 && REG_P (XEXP (SET_SRC (x), 0))
4903 && REGNO (XEXP (SET_SRC (x), 0)) < FIRST_PSEUDO_REGISTER
4904 && p->const_equiv[REGNO (XEXP (SET_SRC (x), 0))] != 0
4905 && GET_CODE (XEXP (SET_SRC (x), 1)) == CONST_INT
4906 && 0 != (new = simplify_binary_operation
4907 (GET_CODE (SET_SRC (x)), GET_MODE (dest),
4908 p->const_equiv[REGNO (XEXP (SET_SRC (x), 0))],
4909 XEXP (SET_SRC (x), 1)))
4910 && GET_CODE (new) == CONST_INT)
4911 p->const_equiv[REGNO (dest)] = new;
4913 /* Otherwise, we can't do anything with this value. */
4915 p->const_equiv[REGNO (dest)] = 0;
4918 /* Emit an insn to do the load shown in p->equiv_reg_src, if needed. */
4921 emit_equiv_load (struct epi_info *p)
4923 if (p->equiv_reg_src != 0)
4925 rtx dest = p->sp_equiv_reg;
4927 if (GET_MODE (p->equiv_reg_src) != GET_MODE (dest))
4928 dest = gen_rtx_REG (GET_MODE (p->equiv_reg_src),
4929 REGNO (p->sp_equiv_reg));
4931 emit_move_insn (dest, p->equiv_reg_src);
4932 p->equiv_reg_src = 0;
4937 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
4938 this into place with notes indicating where the prologue ends and where
4939 the epilogue begins. Update the basic block information when possible. */
4942 thread_prologue_and_epilogue_insns (rtx f ATTRIBUTE_UNUSED)
4946 #if defined (HAVE_sibcall_epilogue) || defined (HAVE_epilogue) || defined (HAVE_return) || defined (HAVE_prologue)
4949 #ifdef HAVE_prologue
4950 rtx prologue_end = NULL_RTX;
4952 #if defined (HAVE_epilogue) || defined(HAVE_return)
4953 rtx epilogue_end = NULL_RTX;
4956 #ifdef HAVE_prologue
4960 seq = gen_prologue ();
4963 /* Retain a map of the prologue insns. */
4964 record_insns (seq, &prologue);
4965 prologue_end = emit_note (NOTE_INSN_PROLOGUE_END);
4969 set_insn_locators (seq, prologue_locator);
4971 /* Can't deal with multiple successors of the entry block
4972 at the moment. Function should always have at least one
4974 if (!ENTRY_BLOCK_PTR->succ || ENTRY_BLOCK_PTR->succ->succ_next)
4977 insert_insn_on_edge (seq, ENTRY_BLOCK_PTR->succ);
4982 /* If the exit block has no non-fake predecessors, we don't need
4984 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
4985 if ((e->flags & EDGE_FAKE) == 0)
4991 if (optimize && HAVE_return)
4993 /* If we're allowed to generate a simple return instruction,
4994 then by definition we don't need a full epilogue. Examine
4995 the block that falls through to EXIT. If it does not
4996 contain any code, examine its predecessors and try to
4997 emit (conditional) return instructions. */
5003 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
5004 if (e->flags & EDGE_FALLTHRU)
5010 /* Verify that there are no active instructions in the last block. */
5011 label = BB_END (last);
5012 while (label && !LABEL_P (label))
5014 if (active_insn_p (label))
5016 label = PREV_INSN (label);
5019 if (BB_HEAD (last) == label && LABEL_P (label))
5021 rtx epilogue_line_note = NULL_RTX;
5023 /* Locate the line number associated with the closing brace,
5024 if we can find one. */
5025 for (seq = get_last_insn ();
5026 seq && ! active_insn_p (seq);
5027 seq = PREV_INSN (seq))
5028 if (NOTE_P (seq) && NOTE_LINE_NUMBER (seq) > 0)
5030 epilogue_line_note = seq;
5034 for (e = last->pred; e; e = e_next)
5036 basic_block bb = e->src;
5039 e_next = e->pred_next;
5040 if (bb == ENTRY_BLOCK_PTR)
5044 if (!JUMP_P (jump) || JUMP_LABEL (jump) != label)
5047 /* If we have an unconditional jump, we can replace that
5048 with a simple return instruction. */
5049 if (simplejump_p (jump))
5051 emit_return_into_block (bb, epilogue_line_note);
5055 /* If we have a conditional jump, we can try to replace
5056 that with a conditional return instruction. */
5057 else if (condjump_p (jump))
5059 if (! redirect_jump (jump, 0, 0))
5062 /* If this block has only one successor, it both jumps
5063 and falls through to the fallthru block, so we can't
5065 if (bb->succ->succ_next == NULL)
5071 /* Fix up the CFG for the successful change we just made. */
5072 redirect_edge_succ (e, EXIT_BLOCK_PTR);
5075 /* Emit a return insn for the exit fallthru block. Whether
5076 this is still reachable will be determined later. */
5078 emit_barrier_after (BB_END (last));
5079 emit_return_into_block (last, epilogue_line_note);
5080 epilogue_end = BB_END (last);
5081 last->succ->flags &= ~EDGE_FALLTHRU;
5086 /* Find the edge that falls through to EXIT. Other edges may exist
5087 due to RETURN instructions, but those don't need epilogues.
5088 There really shouldn't be a mixture -- either all should have
5089 been converted or none, however... */
5091 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
5092 if (e->flags & EDGE_FALLTHRU)
5097 #ifdef HAVE_epilogue
5101 epilogue_end = emit_note (NOTE_INSN_EPILOGUE_BEG);
5103 seq = gen_epilogue ();
5105 #ifdef INCOMING_RETURN_ADDR_RTX
5106 /* If this function returns with the stack depressed and we can support
5107 it, massage the epilogue to actually do that. */
5108 if (TREE_CODE (TREE_TYPE (current_function_decl)) == FUNCTION_TYPE
5109 && TYPE_RETURNS_STACK_DEPRESSED (TREE_TYPE (current_function_decl)))
5110 seq = keep_stack_depressed (seq);
5113 emit_jump_insn (seq);
5115 /* Retain a map of the epilogue insns. */
5116 record_insns (seq, &epilogue);
5117 set_insn_locators (seq, epilogue_locator);
5122 insert_insn_on_edge (seq, e);
5130 if (! next_active_insn (BB_END (e->src)))
5132 /* We have a fall-through edge to the exit block, the source is not
5133 at the end of the function, and there will be an assembler epilogue
5134 at the end of the function.
5135 We can't use force_nonfallthru here, because that would try to
5136 use return. Inserting a jump 'by hand' is extremely messy, so
5137 we take advantage of cfg_layout_finalize using
5138 fixup_fallthru_exit_predecessor. */
5139 cfg_layout_initialize (0);
5140 FOR_EACH_BB (cur_bb)
5141 if (cur_bb->index >= 0 && cur_bb->next_bb->index >= 0)
5142 cur_bb->rbi->next = cur_bb->next_bb;
5143 cfg_layout_finalize ();
5148 commit_edge_insertions ();
5150 #ifdef HAVE_sibcall_epilogue
5151 /* Emit sibling epilogues before any sibling call sites. */
5152 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
5154 basic_block bb = e->src;
5155 rtx insn = BB_END (bb);
5160 || ! SIBLING_CALL_P (insn))
5164 emit_insn (gen_sibcall_epilogue ());
5168 /* Retain a map of the epilogue insns. Used in life analysis to
5169 avoid getting rid of sibcall epilogue insns. Do this before we
5170 actually emit the sequence. */
5171 record_insns (seq, &sibcall_epilogue);
5172 set_insn_locators (seq, epilogue_locator);
5174 i = PREV_INSN (insn);
5175 newinsn = emit_insn_before (seq, insn);
5179 #ifdef HAVE_prologue
5180 /* This is probably all useless now that we use locators. */
5185 /* GDB handles `break f' by setting a breakpoint on the first
5186 line note after the prologue. Which means (1) that if
5187 there are line number notes before where we inserted the
5188 prologue we should move them, and (2) we should generate a
5189 note before the end of the first basic block, if there isn't
5192 ??? This behavior is completely broken when dealing with
5193 multiple entry functions. We simply place the note always
5194 into first basic block and let alternate entry points
5198 for (insn = prologue_end; insn; insn = prev)
5200 prev = PREV_INSN (insn);
5201 if (NOTE_P (insn) && NOTE_LINE_NUMBER (insn) > 0)
5203 /* Note that we cannot reorder the first insn in the
5204 chain, since rest_of_compilation relies on that
5205 remaining constant. */
5208 reorder_insns (insn, insn, prologue_end);
5212 /* Find the last line number note in the first block. */
5213 for (insn = BB_END (ENTRY_BLOCK_PTR->next_bb);
5214 insn != prologue_end && insn;
5215 insn = PREV_INSN (insn))
5216 if (NOTE_P (insn) && NOTE_LINE_NUMBER (insn) > 0)
5219 /* If we didn't find one, make a copy of the first line number
5223 for (insn = next_active_insn (prologue_end);
5225 insn = PREV_INSN (insn))
5226 if (NOTE_P (insn) && NOTE_LINE_NUMBER (insn) > 0)
5228 emit_note_copy_after (insn, prologue_end);
5234 #ifdef HAVE_epilogue
5239 /* Similarly, move any line notes that appear after the epilogue.
5240 There is no need, however, to be quite so anal about the existence
5241 of such a note. Also move the NOTE_INSN_FUNCTION_END and (possibly)
5242 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
5244 for (insn = epilogue_end; insn; insn = next)
5246 next = NEXT_INSN (insn);
5248 && (NOTE_LINE_NUMBER (insn) > 0
5249 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_BEG
5250 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_END))
5251 reorder_insns (insn, insn, PREV_INSN (epilogue_end));
5257 /* Reposition the prologue-end and epilogue-begin notes after instruction
5258 scheduling and delayed branch scheduling. */
5261 reposition_prologue_and_epilogue_notes (rtx f ATTRIBUTE_UNUSED)
5263 #if defined (HAVE_prologue) || defined (HAVE_epilogue)
5264 rtx insn, last, note;
5267 if ((len = VARRAY_SIZE (prologue)) > 0)
5271 /* Scan from the beginning until we reach the last prologue insn.
5272 We apparently can't depend on basic_block_{head,end} after
5274 for (insn = f; insn; insn = NEXT_INSN (insn))
5278 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_PROLOGUE_END)
5281 else if (contains (insn, prologue))
5291 /* Find the prologue-end note if we haven't already, and
5292 move it to just after the last prologue insn. */
5295 for (note = last; (note = NEXT_INSN (note));)
5297 && NOTE_LINE_NUMBER (note) == NOTE_INSN_PROLOGUE_END)
5301 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
5303 last = NEXT_INSN (last);
5304 reorder_insns (note, note, last);
5308 if ((len = VARRAY_SIZE (epilogue)) > 0)
5312 /* Scan from the end until we reach the first epilogue insn.
5313 We apparently can't depend on basic_block_{head,end} after
5315 for (insn = get_last_insn (); insn; insn = PREV_INSN (insn))
5319 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EPILOGUE_BEG)
5322 else if (contains (insn, epilogue))
5332 /* Find the epilogue-begin note if we haven't already, and
5333 move it to just before the first epilogue insn. */
5336 for (note = insn; (note = PREV_INSN (note));)
5338 && NOTE_LINE_NUMBER (note) == NOTE_INSN_EPILOGUE_BEG)
5342 if (PREV_INSN (last) != note)
5343 reorder_insns (note, note, PREV_INSN (last));
5346 #endif /* HAVE_prologue or HAVE_epilogue */
5349 /* Called once, at initialization, to initialize function.c. */
5352 init_function_once (void)
5354 VARRAY_INT_INIT (prologue, 0, "prologue");
5355 VARRAY_INT_INIT (epilogue, 0, "epilogue");
5356 VARRAY_INT_INIT (sibcall_epilogue, 0, "sibcall_epilogue");
5359 /* Resets insn_block_boundaries array. */
5362 reset_block_changes (void)
5364 VARRAY_TREE_INIT (cfun->ib_boundaries_block, 100, "ib_boundaries_block");
5365 VARRAY_PUSH_TREE (cfun->ib_boundaries_block, NULL_TREE);
5368 /* Record the boundary for BLOCK. */
5370 record_block_change (tree block)
5378 last_block = VARRAY_TOP_TREE (cfun->ib_boundaries_block);
5379 VARRAY_POP (cfun->ib_boundaries_block);
5381 for (i = VARRAY_ACTIVE_SIZE (cfun->ib_boundaries_block); i < n; i++)
5382 VARRAY_PUSH_TREE (cfun->ib_boundaries_block, last_block);
5384 VARRAY_PUSH_TREE (cfun->ib_boundaries_block, block);
5387 /* Finishes record of boundaries. */
5388 void finalize_block_changes (void)
5390 record_block_change (DECL_INITIAL (current_function_decl));
5393 /* For INSN return the BLOCK it belongs to. */
5395 check_block_change (rtx insn, tree *block)
5397 unsigned uid = INSN_UID (insn);
5399 if (uid >= VARRAY_ACTIVE_SIZE (cfun->ib_boundaries_block))
5402 *block = VARRAY_TREE (cfun->ib_boundaries_block, uid);
5405 /* Releases the ib_boundaries_block records. */
5407 free_block_changes (void)
5409 cfun->ib_boundaries_block = NULL;
5412 /* Returns the name of the current function. */
5414 current_function_name (void)
5416 return lang_hooks.decl_printable_name (cfun->decl, 2);
5419 #include "gt-function.h"