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.
36 Call `put_var_into_stack' when you learn, belatedly, that a variable
37 previously given a pseudo-register must in fact go in the stack.
38 This function changes the DECL_RTL to be a stack slot instead of a reg
39 then scans all the RTL instructions so far generated to correct them. */
43 #include "coretypes.h"
54 #include "hard-reg-set.h"
55 #include "insn-config.h"
58 #include "basic-block.h"
63 #include "integrate.h"
64 #include "langhooks.h"
66 #include "cfglayout.h"
68 #ifndef LOCAL_ALIGNMENT
69 #define LOCAL_ALIGNMENT(TYPE, ALIGNMENT) ALIGNMENT
72 #ifndef STACK_ALIGNMENT_NEEDED
73 #define STACK_ALIGNMENT_NEEDED 1
76 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
78 /* Some systems use __main in a way incompatible with its use in gcc, in these
79 cases use the macros NAME__MAIN to give a quoted symbol and SYMBOL__MAIN to
80 give the same symbol without quotes for an alternative entry point. You
81 must define both, or neither. */
83 #define NAME__MAIN "__main"
86 /* Round a value to the lowest integer less than it that is a multiple of
87 the required alignment. Avoid using division in case the value is
88 negative. Assume the alignment is a power of two. */
89 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
91 /* Similar, but round to the next highest integer that meets the
93 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
95 /* NEED_SEPARATE_AP means that we cannot derive ap from the value of fp
96 during rtl generation. If they are different register numbers, this is
97 always true. It may also be true if
98 FIRST_PARM_OFFSET - STARTING_FRAME_OFFSET is not a constant during rtl
99 generation. See fix_lexical_addr for details. */
101 #if ARG_POINTER_REGNUM != FRAME_POINTER_REGNUM
102 #define NEED_SEPARATE_AP
105 /* Nonzero if function being compiled doesn't contain any calls
106 (ignoring the prologue and epilogue). This is set prior to
107 local register allocation and is valid for the remaining
109 int current_function_is_leaf;
111 /* Nonzero if function being compiled doesn't contain any instructions
112 that can throw an exception. This is set prior to final. */
114 int current_function_nothrow;
116 /* Nonzero if function being compiled doesn't modify the stack pointer
117 (ignoring the prologue and epilogue). This is only valid after
118 life_analysis has run. */
119 int current_function_sp_is_unchanging;
121 /* Nonzero if the function being compiled is a leaf function which only
122 uses leaf registers. This is valid after reload (specifically after
123 sched2) and is useful only if the port defines LEAF_REGISTERS. */
124 int current_function_uses_only_leaf_regs;
126 /* Nonzero once virtual register instantiation has been done.
127 assign_stack_local uses frame_pointer_rtx when this is nonzero.
128 calls.c:emit_library_call_value_1 uses it to set up
129 post-instantiation libcalls. */
130 int virtuals_instantiated;
132 /* Assign unique numbers to labels generated for profiling, debugging, etc. */
133 static GTY(()) int funcdef_no;
135 /* These variables hold pointers to functions to create and destroy
136 target specific, per-function data structures. */
137 struct machine_function * (*init_machine_status) (void);
139 /* The currently compiled function. */
140 struct function *cfun = 0;
142 /* These arrays record the INSN_UIDs of the prologue and epilogue insns. */
143 static GTY(()) varray_type prologue;
144 static GTY(()) varray_type epilogue;
146 /* Array of INSN_UIDs to hold the INSN_UIDs for each sibcall epilogue
148 static GTY(()) varray_type sibcall_epilogue;
150 /* In order to evaluate some expressions, such as function calls returning
151 structures in memory, we need to temporarily allocate stack locations.
152 We record each allocated temporary in the following structure.
154 Associated with each temporary slot is a nesting level. When we pop up
155 one level, all temporaries associated with the previous level are freed.
156 Normally, all temporaries are freed after the execution of the statement
157 in which they were created. However, if we are inside a ({...}) grouping,
158 the result may be in a temporary and hence must be preserved. If the
159 result could be in a temporary, we preserve it if we can determine which
160 one it is in. If we cannot determine which temporary may contain the
161 result, all temporaries are preserved. A temporary is preserved by
162 pretending it was allocated at the previous nesting level.
164 Automatic variables are also assigned temporary slots, at the nesting
165 level where they are defined. They are marked a "kept" so that
166 free_temp_slots will not free them. */
168 struct temp_slot GTY(())
170 /* Points to next temporary slot. */
171 struct temp_slot *next;
172 /* Points to previous temporary slot. */
173 struct temp_slot *prev;
175 /* The rtx to used to reference the slot. */
177 /* The rtx used to represent the address if not the address of the
178 slot above. May be an EXPR_LIST if multiple addresses exist. */
180 /* The alignment (in bits) of the slot. */
182 /* The size, in units, of the slot. */
184 /* The type of the object in the slot, or zero if it doesn't correspond
185 to a type. We use this to determine whether a slot can be reused.
186 It can be reused if objects of the type of the new slot will always
187 conflict with objects of the type of the old slot. */
189 /* The value of `sequence_rtl_expr' when this temporary is allocated. */
191 /* Nonzero if this temporary is currently in use. */
193 /* Nonzero if this temporary has its address taken. */
195 /* Nesting level at which this slot is being used. */
197 /* Nonzero if this should survive a call to free_temp_slots. */
199 /* The offset of the slot from the frame_pointer, including extra space
200 for alignment. This info is for combine_temp_slots. */
201 HOST_WIDE_INT base_offset;
202 /* The size of the slot, including extra space for alignment. This
203 info is for combine_temp_slots. */
204 HOST_WIDE_INT full_size;
207 /* This structure is used to record MEMs or pseudos used to replace VAR, any
208 SUBREGs of VAR, and any MEMs containing VAR as an address. We need to
209 maintain this list in case two operands of an insn were required to match;
210 in that case we must ensure we use the same replacement. */
212 struct fixup_replacement GTY(())
216 struct fixup_replacement *next;
219 struct insns_for_mem_entry
223 /* These are the INSNs which reference the MEM. */
227 /* Forward declarations. */
229 static rtx assign_stack_local_1 (enum machine_mode, HOST_WIDE_INT, int,
231 static struct temp_slot *find_temp_slot_from_address (rtx);
232 static void put_reg_into_stack (struct function *, rtx, tree, enum machine_mode,
233 unsigned int, bool, bool, bool, htab_t);
234 static void schedule_fixup_var_refs (struct function *, rtx, tree, enum machine_mode,
236 static void fixup_var_refs (rtx, enum machine_mode, int, rtx, htab_t);
237 static struct fixup_replacement
238 *find_fixup_replacement (struct fixup_replacement **, rtx);
239 static void fixup_var_refs_insns (rtx, rtx, enum machine_mode, int, int, rtx);
240 static void fixup_var_refs_insns_with_hash (htab_t, rtx, enum machine_mode, int, rtx);
241 static void fixup_var_refs_insn (rtx, rtx, enum machine_mode, int, int, rtx);
242 static void fixup_var_refs_1 (rtx, enum machine_mode, rtx *, rtx,
243 struct fixup_replacement **, rtx);
244 static rtx fixup_memory_subreg (rtx, rtx, enum machine_mode, int);
245 static rtx walk_fixup_memory_subreg (rtx, rtx, rtx, enum machine_mode, int);
246 static rtx fixup_stack_1 (rtx, rtx);
247 static void optimize_bit_field (rtx, rtx, rtx *);
248 static void instantiate_decls (tree, int);
249 static void instantiate_decls_1 (tree, int);
250 static void instantiate_decl (rtx, HOST_WIDE_INT, int);
251 static rtx instantiate_new_reg (rtx, HOST_WIDE_INT *);
252 static int instantiate_virtual_regs_1 (rtx *, rtx, int);
253 static void pad_to_arg_alignment (struct args_size *, int, struct args_size *);
254 static void pad_below (struct args_size *, enum machine_mode, tree);
255 static tree *identify_blocks_1 (rtx, tree *, tree *, tree *);
256 static void reorder_blocks_1 (rtx, tree, varray_type *);
257 static void reorder_fix_fragments (tree);
258 static int all_blocks (tree, tree *);
259 static tree *get_block_vector (tree, int *);
260 extern tree debug_find_var_in_block_tree (tree, tree);
261 /* We always define `record_insns' even if it's not used so that we
262 can always export `prologue_epilogue_contains'. */
263 static void record_insns (rtx, varray_type *) ATTRIBUTE_UNUSED;
264 static int contains (rtx, varray_type);
266 static void emit_return_into_block (basic_block, rtx);
268 static void put_addressof_into_stack (rtx, htab_t);
269 static bool purge_addressof_1 (rtx *, rtx, int, int, int, htab_t);
270 static void purge_single_hard_subreg_set (rtx);
271 #if defined(HAVE_epilogue) && defined(INCOMING_RETURN_ADDR_RTX)
272 static rtx keep_stack_depressed (rtx);
274 static int is_addressof (rtx *, void *);
275 static hashval_t insns_for_mem_hash (const void *);
276 static int insns_for_mem_comp (const void *, const void *);
277 static int insns_for_mem_walk (rtx *, void *);
278 static void compute_insns_for_mem (rtx, rtx, htab_t);
279 static void prepare_function_start (tree);
280 static void do_clobber_return_reg (rtx, void *);
281 static void do_use_return_reg (rtx, void *);
282 static void instantiate_virtual_regs_lossage (rtx);
283 static tree split_complex_args (tree);
284 static void set_insn_locators (rtx, int) ATTRIBUTE_UNUSED;
286 /* Pointer to chain of `struct function' for containing functions. */
287 struct function *outer_function_chain;
289 /* List of insns that were postponed by purge_addressof_1. */
290 static rtx postponed_insns;
292 /* Given a function decl for a containing function,
293 return the `struct function' for it. */
296 find_function_data (tree decl)
300 for (p = outer_function_chain; p; p = p->outer)
307 /* Save the current context for compilation of a nested function.
308 This is called from language-specific code. The caller should use
309 the enter_nested langhook to save any language-specific state,
310 since this function knows only about language-independent
314 push_function_context_to (tree context)
320 if (context == current_function_decl)
321 cfun->contains_functions = 1;
324 struct function *containing = find_function_data (context);
325 containing->contains_functions = 1;
330 init_dummy_function_start ();
333 p->outer = outer_function_chain;
334 outer_function_chain = p;
335 p->fixup_var_refs_queue = 0;
337 lang_hooks.function.enter_nested (p);
343 push_function_context (void)
345 push_function_context_to (current_function_decl);
348 /* Restore the last saved context, at the end of a nested function.
349 This function is called from language-specific code. */
352 pop_function_context_from (tree context ATTRIBUTE_UNUSED)
354 struct function *p = outer_function_chain;
355 struct var_refs_queue *queue;
358 outer_function_chain = p->outer;
360 current_function_decl = p->decl;
363 restore_emit_status (p);
365 lang_hooks.function.leave_nested (p);
367 /* Finish doing put_var_into_stack for any of our variables which became
368 addressable during the nested function. If only one entry has to be
369 fixed up, just do that one. Otherwise, first make a list of MEMs that
370 are not to be unshared. */
371 if (p->fixup_var_refs_queue == 0)
373 else if (p->fixup_var_refs_queue->next == 0)
374 fixup_var_refs (p->fixup_var_refs_queue->modified,
375 p->fixup_var_refs_queue->promoted_mode,
376 p->fixup_var_refs_queue->unsignedp,
377 p->fixup_var_refs_queue->modified, 0);
382 for (queue = p->fixup_var_refs_queue; queue; queue = queue->next)
383 list = gen_rtx_EXPR_LIST (VOIDmode, queue->modified, list);
385 for (queue = p->fixup_var_refs_queue; queue; queue = queue->next)
386 fixup_var_refs (queue->modified, queue->promoted_mode,
387 queue->unsignedp, list, 0);
391 p->fixup_var_refs_queue = 0;
393 /* Reset variables that have known state during rtx generation. */
394 rtx_equal_function_value_matters = 1;
395 virtuals_instantiated = 0;
396 generating_concat_p = 1;
400 pop_function_context (void)
402 pop_function_context_from (current_function_decl);
405 /* Clear out all parts of the state in F that can safely be discarded
406 after the function has been parsed, but not compiled, to let
407 garbage collection reclaim the memory. */
410 free_after_parsing (struct function *f)
412 /* f->expr->forced_labels is used by code generation. */
413 /* f->emit->regno_reg_rtx is used by code generation. */
414 /* f->varasm is used by code generation. */
415 /* f->eh->eh_return_stub_label is used by code generation. */
417 lang_hooks.function.final (f);
421 /* Clear out all parts of the state in F that can safely be discarded
422 after the function has been compiled, to let garbage collection
423 reclaim the memory. */
426 free_after_compilation (struct function *f)
434 f->x_avail_temp_slots = NULL;
435 f->x_used_temp_slots = NULL;
436 f->arg_offset_rtx = NULL;
437 f->return_rtx = NULL;
438 f->internal_arg_pointer = NULL;
439 f->x_nonlocal_goto_handler_labels = NULL;
440 f->x_cleanup_label = NULL;
441 f->x_return_label = NULL;
442 f->x_naked_return_label = NULL;
443 f->x_save_expr_regs = NULL;
444 f->x_stack_slot_list = NULL;
445 f->x_rtl_expr_chain = NULL;
446 f->x_tail_recursion_reentry = NULL;
447 f->x_arg_pointer_save_area = NULL;
448 f->x_parm_birth_insn = NULL;
449 f->x_parm_reg_stack_loc = NULL;
450 f->fixup_var_refs_queue = NULL;
451 f->original_arg_vector = NULL;
452 f->original_decl_initial = NULL;
453 f->epilogue_delay_list = NULL;
456 /* Allocate fixed slots in the stack frame of the current function. */
458 /* Return size needed for stack frame based on slots so far allocated in
460 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
461 the caller may have to do that. */
464 get_func_frame_size (struct function *f)
466 #ifdef FRAME_GROWS_DOWNWARD
467 return -f->x_frame_offset;
469 return f->x_frame_offset;
473 /* Return size needed for stack frame based on slots so far allocated.
474 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
475 the caller may have to do that. */
477 get_frame_size (void)
479 return get_func_frame_size (cfun);
482 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
483 with machine mode MODE.
485 ALIGN controls the amount of alignment for the address of the slot:
486 0 means according to MODE,
487 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
488 -2 means use BITS_PER_UNIT,
489 positive specifies alignment boundary in bits.
491 We do not round to stack_boundary here.
493 FUNCTION specifies the function to allocate in. */
496 assign_stack_local_1 (enum machine_mode mode, HOST_WIDE_INT size, int align,
497 struct function *function)
500 int bigend_correction = 0;
502 int frame_off, frame_alignment, frame_phase;
509 alignment = BIGGEST_ALIGNMENT;
511 alignment = GET_MODE_ALIGNMENT (mode);
513 /* Allow the target to (possibly) increase the alignment of this
515 type = lang_hooks.types.type_for_mode (mode, 0);
517 alignment = LOCAL_ALIGNMENT (type, alignment);
519 alignment /= BITS_PER_UNIT;
521 else if (align == -1)
523 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
524 size = CEIL_ROUND (size, alignment);
526 else if (align == -2)
527 alignment = 1; /* BITS_PER_UNIT / BITS_PER_UNIT */
529 alignment = align / BITS_PER_UNIT;
531 #ifdef FRAME_GROWS_DOWNWARD
532 function->x_frame_offset -= size;
535 /* Ignore alignment we can't do with expected alignment of the boundary. */
536 if (alignment * BITS_PER_UNIT > PREFERRED_STACK_BOUNDARY)
537 alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
539 if (function->stack_alignment_needed < alignment * BITS_PER_UNIT)
540 function->stack_alignment_needed = alignment * BITS_PER_UNIT;
542 /* Calculate how many bytes the start of local variables is off from
544 frame_alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
545 frame_off = STARTING_FRAME_OFFSET % frame_alignment;
546 frame_phase = frame_off ? frame_alignment - frame_off : 0;
548 /* Round the frame offset to the specified alignment. The default is
549 to always honor requests to align the stack but a port may choose to
550 do its own stack alignment by defining STACK_ALIGNMENT_NEEDED. */
551 if (STACK_ALIGNMENT_NEEDED
555 /* We must be careful here, since FRAME_OFFSET might be negative and
556 division with a negative dividend isn't as well defined as we might
557 like. So we instead assume that ALIGNMENT is a power of two and
558 use logical operations which are unambiguous. */
559 #ifdef FRAME_GROWS_DOWNWARD
560 function->x_frame_offset
561 = (FLOOR_ROUND (function->x_frame_offset - frame_phase, alignment)
564 function->x_frame_offset
565 = (CEIL_ROUND (function->x_frame_offset - frame_phase, alignment)
570 /* On a big-endian machine, if we are allocating more space than we will use,
571 use the least significant bytes of those that are allocated. */
572 if (BYTES_BIG_ENDIAN && mode != BLKmode)
573 bigend_correction = size - GET_MODE_SIZE (mode);
575 /* If we have already instantiated virtual registers, return the actual
576 address relative to the frame pointer. */
577 if (function == cfun && virtuals_instantiated)
578 addr = plus_constant (frame_pointer_rtx,
580 (frame_offset + bigend_correction
581 + STARTING_FRAME_OFFSET, Pmode));
583 addr = plus_constant (virtual_stack_vars_rtx,
585 (function->x_frame_offset + bigend_correction,
588 #ifndef FRAME_GROWS_DOWNWARD
589 function->x_frame_offset += size;
592 x = gen_rtx_MEM (mode, addr);
594 function->x_stack_slot_list
595 = gen_rtx_EXPR_LIST (VOIDmode, x, function->x_stack_slot_list);
600 /* Wrapper around assign_stack_local_1; assign a local stack slot for the
604 assign_stack_local (enum machine_mode mode, HOST_WIDE_INT size, int align)
606 return assign_stack_local_1 (mode, size, align, cfun);
610 /* Removes temporary slot TEMP from LIST. */
613 cut_slot_from_list (struct temp_slot *temp, struct temp_slot **list)
616 temp->next->prev = temp->prev;
618 temp->prev->next = temp->next;
622 temp->prev = temp->next = NULL;
625 /* Inserts temporary slot TEMP to LIST. */
628 insert_slot_to_list (struct temp_slot *temp, struct temp_slot **list)
632 (*list)->prev = temp;
637 /* Returns the list of used temp slots at LEVEL. */
639 static struct temp_slot **
640 temp_slots_at_level (int level)
644 if (!used_temp_slots)
645 VARRAY_GENERIC_PTR_INIT (used_temp_slots, 3, "used_temp_slots");
647 while (level >= (int) VARRAY_ACTIVE_SIZE (used_temp_slots))
648 VARRAY_PUSH_GENERIC_PTR (used_temp_slots, NULL);
650 return (struct temp_slot **) &VARRAY_GENERIC_PTR (used_temp_slots, level);
653 /* Returns the maximal temporary slot level. */
656 max_slot_level (void)
658 if (!used_temp_slots)
661 return VARRAY_ACTIVE_SIZE (used_temp_slots) - 1;
664 /* Moves temporary slot TEMP to LEVEL. */
667 move_slot_to_level (struct temp_slot *temp, int level)
669 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
670 insert_slot_to_list (temp, temp_slots_at_level (level));
674 /* Make temporary slot TEMP available. */
677 make_slot_available (struct temp_slot *temp)
679 cut_slot_from_list (temp, temp_slots_at_level (temp->level));
680 insert_slot_to_list (temp, &avail_temp_slots);
685 /* Allocate a temporary stack slot and record it for possible later
688 MODE is the machine mode to be given to the returned rtx.
690 SIZE is the size in units of the space required. We do no rounding here
691 since assign_stack_local will do any required rounding.
693 KEEP is 1 if this slot is to be retained after a call to
694 free_temp_slots. Automatic variables for a block are allocated
695 with this flag. KEEP is 2 if we allocate a longer term temporary,
696 whose lifetime is controlled by CLEANUP_POINT_EXPRs. KEEP is 3
697 if we are to allocate something at an inner level to be treated as
698 a variable in the block (e.g., a SAVE_EXPR).
700 TYPE is the type that will be used for the stack slot. */
703 assign_stack_temp_for_type (enum machine_mode mode, HOST_WIDE_INT size, int keep,
707 struct temp_slot *p, *best_p = 0, *selected = NULL, **pp;
710 /* If SIZE is -1 it means that somebody tried to allocate a temporary
711 of a variable size. */
716 align = BIGGEST_ALIGNMENT;
718 align = GET_MODE_ALIGNMENT (mode);
721 type = lang_hooks.types.type_for_mode (mode, 0);
724 align = LOCAL_ALIGNMENT (type, align);
726 /* Try to find an available, already-allocated temporary of the proper
727 mode which meets the size and alignment requirements. Choose the
728 smallest one with the closest alignment. */
729 for (p = avail_temp_slots; p; p = p->next)
731 if (p->align >= align && p->size >= size && GET_MODE (p->slot) == mode
732 && objects_must_conflict_p (p->type, type)
733 && (best_p == 0 || best_p->size > p->size
734 || (best_p->size == p->size && best_p->align > p->align)))
736 if (p->align == align && p->size == size)
739 cut_slot_from_list (selected, &avail_temp_slots);
747 /* Make our best, if any, the one to use. */
751 cut_slot_from_list (selected, &avail_temp_slots);
753 /* If there are enough aligned bytes left over, make them into a new
754 temp_slot so that the extra bytes don't get wasted. Do this only
755 for BLKmode slots, so that we can be sure of the alignment. */
756 if (GET_MODE (best_p->slot) == BLKmode)
758 int alignment = best_p->align / BITS_PER_UNIT;
759 HOST_WIDE_INT rounded_size = CEIL_ROUND (size, alignment);
761 if (best_p->size - rounded_size >= alignment)
763 p = ggc_alloc (sizeof (struct temp_slot));
764 p->in_use = p->addr_taken = 0;
765 p->size = best_p->size - rounded_size;
766 p->base_offset = best_p->base_offset + rounded_size;
767 p->full_size = best_p->full_size - rounded_size;
768 p->slot = gen_rtx_MEM (BLKmode,
769 plus_constant (XEXP (best_p->slot, 0),
771 p->align = best_p->align;
774 p->type = best_p->type;
775 insert_slot_to_list (p, &avail_temp_slots);
777 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, p->slot,
780 best_p->size = rounded_size;
781 best_p->full_size = rounded_size;
786 /* If we still didn't find one, make a new temporary. */
789 HOST_WIDE_INT frame_offset_old = frame_offset;
791 p = ggc_alloc (sizeof (struct temp_slot));
793 /* We are passing an explicit alignment request to assign_stack_local.
794 One side effect of that is assign_stack_local will not round SIZE
795 to ensure the frame offset remains suitably aligned.
797 So for requests which depended on the rounding of SIZE, we go ahead
798 and round it now. We also make sure ALIGNMENT is at least
799 BIGGEST_ALIGNMENT. */
800 if (mode == BLKmode && align < BIGGEST_ALIGNMENT)
802 p->slot = assign_stack_local (mode,
804 ? CEIL_ROUND (size, (int) align / BITS_PER_UNIT)
810 /* The following slot size computation is necessary because we don't
811 know the actual size of the temporary slot until assign_stack_local
812 has performed all the frame alignment and size rounding for the
813 requested temporary. Note that extra space added for alignment
814 can be either above or below this stack slot depending on which
815 way the frame grows. We include the extra space if and only if it
816 is above this slot. */
817 #ifdef FRAME_GROWS_DOWNWARD
818 p->size = frame_offset_old - frame_offset;
823 /* Now define the fields used by combine_temp_slots. */
824 #ifdef FRAME_GROWS_DOWNWARD
825 p->base_offset = frame_offset;
826 p->full_size = frame_offset_old - frame_offset;
828 p->base_offset = frame_offset_old;
829 p->full_size = frame_offset - frame_offset_old;
839 p->rtl_expr = seq_rtl_expr;
844 p->level = target_temp_slot_level;
849 p->level = var_temp_slot_level;
854 p->level = temp_slot_level;
858 pp = temp_slots_at_level (p->level);
859 insert_slot_to_list (p, pp);
861 /* Create a new MEM rtx to avoid clobbering MEM flags of old slots. */
862 slot = gen_rtx_MEM (mode, XEXP (p->slot, 0));
863 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, slot, stack_slot_list);
865 /* If we know the alias set for the memory that will be used, use
866 it. If there's no TYPE, then we don't know anything about the
867 alias set for the memory. */
868 set_mem_alias_set (slot, type ? get_alias_set (type) : 0);
869 set_mem_align (slot, align);
871 /* If a type is specified, set the relevant flags. */
874 RTX_UNCHANGING_P (slot) = (lang_hooks.honor_readonly
875 && TYPE_READONLY (type));
876 MEM_VOLATILE_P (slot) = TYPE_VOLATILE (type);
877 MEM_SET_IN_STRUCT_P (slot, AGGREGATE_TYPE_P (type));
883 /* Allocate a temporary stack slot and record it for possible later
884 reuse. First three arguments are same as in preceding function. */
887 assign_stack_temp (enum machine_mode mode, HOST_WIDE_INT size, int keep)
889 return assign_stack_temp_for_type (mode, size, keep, NULL_TREE);
892 /* Assign a temporary.
893 If TYPE_OR_DECL is a decl, then we are doing it on behalf of the decl
894 and so that should be used in error messages. In either case, we
895 allocate of the given type.
896 KEEP is as for assign_stack_temp.
897 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
898 it is 0 if a register is OK.
899 DONT_PROMOTE is 1 if we should not promote values in register
903 assign_temp (tree type_or_decl, int keep, int memory_required,
904 int dont_promote ATTRIBUTE_UNUSED)
907 enum machine_mode mode;
912 if (DECL_P (type_or_decl))
913 decl = type_or_decl, type = TREE_TYPE (decl);
915 decl = NULL, type = type_or_decl;
917 mode = TYPE_MODE (type);
919 unsignedp = TYPE_UNSIGNED (type);
922 if (mode == BLKmode || memory_required)
924 HOST_WIDE_INT size = int_size_in_bytes (type);
927 /* Zero sized arrays are GNU C extension. Set size to 1 to avoid
928 problems with allocating the stack space. */
932 /* Unfortunately, we don't yet know how to allocate variable-sized
933 temporaries. However, sometimes we have a fixed upper limit on
934 the size (which is stored in TYPE_ARRAY_MAX_SIZE) and can use that
935 instead. This is the case for Chill variable-sized strings. */
936 if (size == -1 && TREE_CODE (type) == ARRAY_TYPE
937 && TYPE_ARRAY_MAX_SIZE (type) != NULL_TREE
938 && host_integerp (TYPE_ARRAY_MAX_SIZE (type), 1))
939 size = tree_low_cst (TYPE_ARRAY_MAX_SIZE (type), 1);
941 /* The size of the temporary may be too large to fit into an integer. */
942 /* ??? Not sure this should happen except for user silliness, so limit
943 this to things that aren't compiler-generated temporaries. The
944 rest of the time we'll abort in assign_stack_temp_for_type. */
945 if (decl && size == -1
946 && TREE_CODE (TYPE_SIZE_UNIT (type)) == INTEGER_CST)
948 error ("%Jsize of variable '%D' is too large", decl, decl);
952 tmp = assign_stack_temp_for_type (mode, size, keep, type);
958 mode = promote_mode (type, mode, &unsignedp, 0);
961 return gen_reg_rtx (mode);
964 /* Combine temporary stack slots which are adjacent on the stack.
966 This allows for better use of already allocated stack space. This is only
967 done for BLKmode slots because we can be sure that we won't have alignment
968 problems in this case. */
971 combine_temp_slots (void)
973 struct temp_slot *p, *q, *next, *next_q;
976 /* We can't combine slots, because the information about which slot
977 is in which alias set will be lost. */
978 if (flag_strict_aliasing)
981 /* If there are a lot of temp slots, don't do anything unless
982 high levels of optimization. */
983 if (! flag_expensive_optimizations)
984 for (p = avail_temp_slots, num_slots = 0; p; p = p->next, num_slots++)
985 if (num_slots > 100 || (num_slots > 10 && optimize == 0))
988 for (p = avail_temp_slots; p; p = next)
994 if (GET_MODE (p->slot) != BLKmode)
997 for (q = p->next; q; q = next_q)
1003 if (GET_MODE (q->slot) != BLKmode)
1006 if (p->base_offset + p->full_size == q->base_offset)
1008 /* Q comes after P; combine Q into P. */
1010 p->full_size += q->full_size;
1013 else if (q->base_offset + q->full_size == p->base_offset)
1015 /* P comes after Q; combine P into Q. */
1017 q->full_size += p->full_size;
1022 cut_slot_from_list (q, &avail_temp_slots);
1025 /* Either delete P or advance past it. */
1027 cut_slot_from_list (p, &avail_temp_slots);
1031 /* Find the temp slot corresponding to the object at address X. */
1033 static struct temp_slot *
1034 find_temp_slot_from_address (rtx x)
1036 struct temp_slot *p;
1040 for (i = max_slot_level (); i >= 0; i--)
1041 for (p = *temp_slots_at_level (i); p; p = p->next)
1043 if (XEXP (p->slot, 0) == x
1045 || (GET_CODE (x) == PLUS
1046 && XEXP (x, 0) == virtual_stack_vars_rtx
1047 && GET_CODE (XEXP (x, 1)) == CONST_INT
1048 && INTVAL (XEXP (x, 1)) >= p->base_offset
1049 && INTVAL (XEXP (x, 1)) < p->base_offset + p->full_size))
1052 else if (p->address != 0 && GET_CODE (p->address) == EXPR_LIST)
1053 for (next = p->address; next; next = XEXP (next, 1))
1054 if (XEXP (next, 0) == x)
1058 /* If we have a sum involving a register, see if it points to a temp
1060 if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 0))
1061 && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
1063 else if (GET_CODE (x) == PLUS && REG_P (XEXP (x, 1))
1064 && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
1070 /* Indicate that NEW is an alternate way of referring to the temp slot
1071 that previously was known by OLD. */
1074 update_temp_slot_address (rtx old, rtx new)
1076 struct temp_slot *p;
1078 if (rtx_equal_p (old, new))
1081 p = find_temp_slot_from_address (old);
1083 /* If we didn't find one, see if both OLD is a PLUS. If so, and NEW
1084 is a register, see if one operand of the PLUS is a temporary
1085 location. If so, NEW points into it. Otherwise, if both OLD and
1086 NEW are a PLUS and if there is a register in common between them.
1087 If so, try a recursive call on those values. */
1090 if (GET_CODE (old) != PLUS)
1095 update_temp_slot_address (XEXP (old, 0), new);
1096 update_temp_slot_address (XEXP (old, 1), new);
1099 else if (GET_CODE (new) != PLUS)
1102 if (rtx_equal_p (XEXP (old, 0), XEXP (new, 0)))
1103 update_temp_slot_address (XEXP (old, 1), XEXP (new, 1));
1104 else if (rtx_equal_p (XEXP (old, 1), XEXP (new, 0)))
1105 update_temp_slot_address (XEXP (old, 0), XEXP (new, 1));
1106 else if (rtx_equal_p (XEXP (old, 0), XEXP (new, 1)))
1107 update_temp_slot_address (XEXP (old, 1), XEXP (new, 0));
1108 else if (rtx_equal_p (XEXP (old, 1), XEXP (new, 1)))
1109 update_temp_slot_address (XEXP (old, 0), XEXP (new, 0));
1114 /* Otherwise add an alias for the temp's address. */
1115 else if (p->address == 0)
1119 if (GET_CODE (p->address) != EXPR_LIST)
1120 p->address = gen_rtx_EXPR_LIST (VOIDmode, p->address, NULL_RTX);
1122 p->address = gen_rtx_EXPR_LIST (VOIDmode, new, p->address);
1126 /* If X could be a reference to a temporary slot, mark the fact that its
1127 address was taken. */
1130 mark_temp_addr_taken (rtx x)
1132 struct temp_slot *p;
1137 /* If X is not in memory or is at a constant address, it cannot be in
1138 a temporary slot. */
1139 if (GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0)))
1142 p = find_temp_slot_from_address (XEXP (x, 0));
1147 /* If X could be a reference to a temporary slot, mark that slot as
1148 belonging to the to one level higher than the current level. If X
1149 matched one of our slots, just mark that one. Otherwise, we can't
1150 easily predict which it is, so upgrade all of them. Kept slots
1151 need not be touched.
1153 This is called when an ({...}) construct occurs and a statement
1154 returns a value in memory. */
1157 preserve_temp_slots (rtx x)
1159 struct temp_slot *p = 0, *next;
1161 /* If there is no result, we still might have some objects whose address
1162 were taken, so we need to make sure they stay around. */
1165 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1170 move_slot_to_level (p, temp_slot_level - 1);
1176 /* If X is a register that is being used as a pointer, see if we have
1177 a temporary slot we know it points to. To be consistent with
1178 the code below, we really should preserve all non-kept slots
1179 if we can't find a match, but that seems to be much too costly. */
1180 if (REG_P (x) && REG_POINTER (x))
1181 p = find_temp_slot_from_address (x);
1183 /* If X is not in memory or is at a constant address, it cannot be in
1184 a temporary slot, but it can contain something whose address was
1186 if (p == 0 && (GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0))))
1188 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1193 move_slot_to_level (p, temp_slot_level - 1);
1199 /* First see if we can find a match. */
1201 p = find_temp_slot_from_address (XEXP (x, 0));
1205 /* Move everything at our level whose address was taken to our new
1206 level in case we used its address. */
1207 struct temp_slot *q;
1209 if (p->level == temp_slot_level)
1211 for (q = *temp_slots_at_level (temp_slot_level); q; q = next)
1215 if (p != q && q->addr_taken)
1216 move_slot_to_level (q, temp_slot_level - 1);
1219 move_slot_to_level (p, temp_slot_level - 1);
1225 /* Otherwise, preserve all non-kept slots at this level. */
1226 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1231 move_slot_to_level (p, temp_slot_level - 1);
1235 /* X is the result of an RTL_EXPR. If it is a temporary slot associated
1236 with that RTL_EXPR, promote it into a temporary slot at the present
1237 level so it will not be freed when we free slots made in the
1241 preserve_rtl_expr_result (rtx x)
1243 struct temp_slot *p;
1245 /* If X is not in memory or is at a constant address, it cannot be in
1246 a temporary slot. */
1247 if (x == 0 || GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0)))
1250 /* If we can find a match, move it to our level unless it is already at
1252 p = find_temp_slot_from_address (XEXP (x, 0));
1255 move_slot_to_level (p, MIN (p->level, temp_slot_level));
1262 /* Free all temporaries used so far. This is normally called at the end
1263 of generating code for a statement. Don't free any temporaries
1264 currently in use for an RTL_EXPR that hasn't yet been emitted.
1265 We could eventually do better than this since it can be reused while
1266 generating the same RTL_EXPR, but this is complex and probably not
1270 free_temp_slots (void)
1272 struct temp_slot *p, *next;
1274 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1278 if (!p->keep && p->rtl_expr == 0)
1279 make_slot_available (p);
1282 combine_temp_slots ();
1285 /* Free all temporary slots used in T, an RTL_EXPR node. */
1288 free_temps_for_rtl_expr (tree t)
1290 struct temp_slot *p, *next;
1292 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1296 if (p->rtl_expr == t)
1298 /* If this slot is below the current TEMP_SLOT_LEVEL, then it
1299 needs to be preserved. This can happen if a temporary in
1300 the RTL_EXPR was addressed; preserve_temp_slots will move
1301 the temporary into a higher level. */
1302 if (temp_slot_level <= p->level)
1303 make_slot_available (p);
1305 p->rtl_expr = NULL_TREE;
1309 combine_temp_slots ();
1312 /* Push deeper into the nesting level for stack temporaries. */
1315 push_temp_slots (void)
1320 /* Pop a temporary nesting level. All slots in use in the current level
1324 pop_temp_slots (void)
1326 struct temp_slot *p, *next;
1328 for (p = *temp_slots_at_level (temp_slot_level); p; p = next)
1332 if (p->rtl_expr == 0)
1333 make_slot_available (p);
1336 combine_temp_slots ();
1341 /* Initialize temporary slots. */
1344 init_temp_slots (void)
1346 /* We have not allocated any temporaries yet. */
1347 avail_temp_slots = 0;
1348 used_temp_slots = 0;
1349 temp_slot_level = 0;
1350 var_temp_slot_level = 0;
1351 target_temp_slot_level = 0;
1354 /* Retroactively move an auto variable from a register to a stack
1355 slot. This is done when an address-reference to the variable is
1356 seen. If RESCAN is true, all previously emitted instructions are
1357 examined and modified to handle the fact that DECL is now
1361 put_var_into_stack (tree decl, int rescan)
1364 enum machine_mode promoted_mode, decl_mode;
1365 struct function *function = 0;
1367 bool can_use_addressof_p;
1368 bool volatile_p = TREE_CODE (decl) != SAVE_EXPR && TREE_THIS_VOLATILE (decl);
1369 bool used_p = (TREE_USED (decl)
1370 || (TREE_CODE (decl) != SAVE_EXPR && DECL_INITIAL (decl) != 0));
1372 context = decl_function_context (decl);
1374 /* Get the current rtl used for this object and its original mode. */
1375 orig_reg = reg = (TREE_CODE (decl) == SAVE_EXPR
1376 ? SAVE_EXPR_RTL (decl)
1377 : DECL_RTL_IF_SET (decl));
1379 /* No need to do anything if decl has no rtx yet
1380 since in that case caller is setting TREE_ADDRESSABLE
1381 and a stack slot will be assigned when the rtl is made. */
1385 /* Get the declared mode for this object. */
1386 decl_mode = (TREE_CODE (decl) == SAVE_EXPR ? TYPE_MODE (TREE_TYPE (decl))
1387 : DECL_MODE (decl));
1388 /* Get the mode it's actually stored in. */
1389 promoted_mode = GET_MODE (reg);
1391 /* If this variable comes from an outer function, find that
1392 function's saved context. Don't use find_function_data here,
1393 because it might not be in any active function.
1394 FIXME: Is that really supposed to happen?
1395 It does in ObjC at least. */
1396 if (context != current_function_decl)
1397 for (function = outer_function_chain; function; function = function->outer)
1398 if (function->decl == context)
1401 /* If this is a variable-sized object or a structure passed by invisible
1402 reference, with a pseudo to address it, put that pseudo into the stack
1403 if the var is non-local. */
1404 if (TREE_CODE (decl) != SAVE_EXPR && DECL_NONLOCAL (decl)
1405 && GET_CODE (reg) == MEM
1406 && REG_P (XEXP (reg, 0))
1407 && REGNO (XEXP (reg, 0)) > LAST_VIRTUAL_REGISTER)
1409 orig_reg = reg = XEXP (reg, 0);
1410 decl_mode = promoted_mode = GET_MODE (reg);
1413 /* If this variable lives in the current function and we don't need to put it
1414 in the stack for the sake of setjmp or the non-locality, try to keep it in
1415 a register until we know we actually need the address. */
1418 && ! (TREE_CODE (decl) != SAVE_EXPR && DECL_NONLOCAL (decl))
1420 /* FIXME make it work for promoted modes too */
1421 && decl_mode == promoted_mode
1422 #ifdef NON_SAVING_SETJMP
1423 && ! (NON_SAVING_SETJMP && current_function_calls_setjmp)
1427 /* If we can't use ADDRESSOF, make sure we see through one we already
1429 if (! can_use_addressof_p
1430 && GET_CODE (reg) == MEM
1431 && GET_CODE (XEXP (reg, 0)) == ADDRESSOF)
1432 reg = XEXP (XEXP (reg, 0), 0);
1434 /* Now we should have a value that resides in one or more pseudo regs. */
1438 if (can_use_addressof_p)
1439 gen_mem_addressof (reg, decl, rescan);
1441 put_reg_into_stack (function, reg, TREE_TYPE (decl), decl_mode,
1442 0, volatile_p, used_p, false, 0);
1444 /* If this was previously a MEM but we've removed the ADDRESSOF,
1445 set this address into that MEM so we always use the same
1446 rtx for this variable. */
1447 if (orig_reg != reg && GET_CODE (orig_reg) == MEM)
1448 XEXP (orig_reg, 0) = XEXP (reg, 0);
1450 else if (GET_CODE (reg) == CONCAT)
1452 /* A CONCAT contains two pseudos; put them both in the stack.
1453 We do it so they end up consecutive.
1454 We fixup references to the parts only after we fixup references
1455 to the whole CONCAT, lest we do double fixups for the latter
1457 enum machine_mode part_mode = GET_MODE (XEXP (reg, 0));
1458 tree part_type = lang_hooks.types.type_for_mode (part_mode, 0);
1459 rtx lopart = XEXP (reg, 0);
1460 rtx hipart = XEXP (reg, 1);
1461 #ifdef FRAME_GROWS_DOWNWARD
1462 /* Since part 0 should have a lower address, do it second. */
1463 put_reg_into_stack (function, hipart, part_type, part_mode,
1464 0, volatile_p, false, false, 0);
1465 put_reg_into_stack (function, lopart, part_type, part_mode,
1466 0, volatile_p, false, true, 0);
1468 put_reg_into_stack (function, lopart, part_type, part_mode,
1469 0, volatile_p, false, false, 0);
1470 put_reg_into_stack (function, hipart, part_type, part_mode,
1471 0, volatile_p, false, true, 0);
1474 /* Change the CONCAT into a combined MEM for both parts. */
1475 PUT_CODE (reg, MEM);
1476 MEM_ATTRS (reg) = 0;
1478 /* set_mem_attributes uses DECL_RTL to avoid re-generating of
1479 already computed alias sets. Here we want to re-generate. */
1481 SET_DECL_RTL (decl, NULL);
1482 set_mem_attributes (reg, decl, 1);
1484 SET_DECL_RTL (decl, reg);
1486 /* The two parts are in memory order already.
1487 Use the lower parts address as ours. */
1488 XEXP (reg, 0) = XEXP (XEXP (reg, 0), 0);
1489 /* Prevent sharing of rtl that might lose. */
1490 if (GET_CODE (XEXP (reg, 0)) == PLUS)
1491 XEXP (reg, 0) = copy_rtx (XEXP (reg, 0));
1492 if (used_p && rescan)
1494 schedule_fixup_var_refs (function, reg, TREE_TYPE (decl),
1496 schedule_fixup_var_refs (function, lopart, part_type, part_mode, 0);
1497 schedule_fixup_var_refs (function, hipart, part_type, part_mode, 0);
1504 /* Subroutine of put_var_into_stack. This puts a single pseudo reg REG
1505 into the stack frame of FUNCTION (0 means the current function).
1506 TYPE is the user-level data type of the value hold in the register.
1507 DECL_MODE is the machine mode of the user-level data type.
1508 ORIGINAL_REGNO must be set if the real regno is not visible in REG.
1509 VOLATILE_P is true if this is for a "volatile" decl.
1510 USED_P is true if this reg might have already been used in an insn.
1511 CONSECUTIVE_P is true if the stack slot assigned to reg must be
1512 consecutive with the previous stack slot. */
1515 put_reg_into_stack (struct function *function, rtx reg, tree type,
1516 enum machine_mode decl_mode, unsigned int original_regno,
1517 bool volatile_p, bool used_p, bool consecutive_p,
1520 struct function *func = function ? function : cfun;
1521 enum machine_mode mode = GET_MODE (reg);
1522 unsigned int regno = original_regno;
1526 regno = REGNO (reg);
1528 if (regno < func->x_max_parm_reg)
1530 if (!func->x_parm_reg_stack_loc)
1532 new = func->x_parm_reg_stack_loc[regno];
1536 new = assign_stack_local_1 (decl_mode, GET_MODE_SIZE (decl_mode),
1537 consecutive_p ? -2 : 0, func);
1539 PUT_CODE (reg, MEM);
1540 PUT_MODE (reg, decl_mode);
1541 XEXP (reg, 0) = XEXP (new, 0);
1542 MEM_ATTRS (reg) = 0;
1543 /* `volatil' bit means one thing for MEMs, another entirely for REGs. */
1544 MEM_VOLATILE_P (reg) = volatile_p;
1546 /* If this is a memory ref that contains aggregate components,
1547 mark it as such for cse and loop optimize. If we are reusing a
1548 previously generated stack slot, then we need to copy the bit in
1549 case it was set for other reasons. For instance, it is set for
1550 __builtin_va_alist. */
1553 MEM_SET_IN_STRUCT_P (reg,
1554 AGGREGATE_TYPE_P (type) || MEM_IN_STRUCT_P (new));
1555 set_mem_alias_set (reg, get_alias_set (type));
1559 schedule_fixup_var_refs (function, reg, type, mode, ht);
1562 /* Make sure that all refs to the variable, previously made
1563 when it was a register, are fixed up to be valid again.
1564 See function above for meaning of arguments. */
1567 schedule_fixup_var_refs (struct function *function, rtx reg, tree type,
1568 enum machine_mode promoted_mode, htab_t ht)
1570 int unsigned_p = type ? TYPE_UNSIGNED (type) : 0;
1574 struct var_refs_queue *temp;
1576 temp = ggc_alloc (sizeof (struct var_refs_queue));
1577 temp->modified = reg;
1578 temp->promoted_mode = promoted_mode;
1579 temp->unsignedp = unsigned_p;
1580 temp->next = function->fixup_var_refs_queue;
1581 function->fixup_var_refs_queue = temp;
1584 /* Variable is local; fix it up now. */
1585 fixup_var_refs (reg, promoted_mode, unsigned_p, reg, ht);
1589 fixup_var_refs (rtx var, enum machine_mode promoted_mode, int unsignedp,
1590 rtx may_share, htab_t ht)
1593 rtx first_insn = get_insns ();
1594 struct sequence_stack *stack = seq_stack;
1595 tree rtl_exps = rtl_expr_chain;
1596 int save_volatile_ok = volatile_ok;
1598 /* If there's a hash table, it must record all uses of VAR. */
1603 fixup_var_refs_insns_with_hash (ht, var, promoted_mode, unsignedp,
1608 /* Volatile is valid in MEMs because all we're doing in changing the
1611 fixup_var_refs_insns (first_insn, var, promoted_mode, unsignedp,
1612 stack == 0, may_share);
1614 /* Scan all pending sequences too. */
1615 for (; stack; stack = stack->next)
1617 push_to_full_sequence (stack->first, stack->last);
1618 fixup_var_refs_insns (stack->first, var, promoted_mode, unsignedp,
1619 stack->next != 0, may_share);
1620 /* Update bounds of sequence in case we added insns. */
1621 stack->first = get_insns ();
1622 stack->last = get_last_insn ();
1626 /* Scan all waiting RTL_EXPRs too. */
1627 for (pending = rtl_exps; pending; pending = TREE_CHAIN (pending))
1629 rtx seq = RTL_EXPR_SEQUENCE (TREE_VALUE (pending));
1630 if (seq != const0_rtx && seq != 0)
1632 push_to_sequence (seq);
1633 fixup_var_refs_insns (seq, var, promoted_mode, unsignedp, 0,
1639 volatile_ok = save_volatile_ok;
1642 /* REPLACEMENTS is a pointer to a list of the struct fixup_replacement and X is
1643 some part of an insn. Return a struct fixup_replacement whose OLD
1644 value is equal to X. Allocate a new structure if no such entry exists. */
1646 static struct fixup_replacement *
1647 find_fixup_replacement (struct fixup_replacement **replacements, rtx x)
1649 struct fixup_replacement *p;
1651 /* See if we have already replaced this. */
1652 for (p = *replacements; p != 0 && ! rtx_equal_p (p->old, x); p = p->next)
1657 p = xmalloc (sizeof (struct fixup_replacement));
1660 p->next = *replacements;
1667 /* Scan the insn-chain starting with INSN for refs to VAR and fix them
1668 up. TOPLEVEL is nonzero if this chain is the main chain of insns
1669 for the current function. MAY_SHARE is either a MEM that is not
1670 to be unshared or a list of them. */
1673 fixup_var_refs_insns (rtx insn, rtx var, enum machine_mode promoted_mode,
1674 int unsignedp, int toplevel, rtx may_share)
1678 /* fixup_var_refs_insn might modify insn, so save its next
1680 rtx next = NEXT_INSN (insn);
1683 fixup_var_refs_insn (insn, var, promoted_mode, unsignedp, toplevel,
1690 /* Look up the insns which reference VAR in HT and fix them up. Other
1691 arguments are the same as fixup_var_refs_insns. */
1694 fixup_var_refs_insns_with_hash (htab_t ht, rtx var, enum machine_mode promoted_mode,
1695 int unsignedp, rtx may_share)
1697 struct insns_for_mem_entry tmp;
1698 struct insns_for_mem_entry *ime;
1702 ime = htab_find (ht, &tmp);
1703 for (insn_list = ime->insns; insn_list != 0; insn_list = XEXP (insn_list, 1))
1704 if (INSN_P (XEXP (insn_list, 0)))
1705 fixup_var_refs_insn (XEXP (insn_list, 0), var, promoted_mode,
1706 unsignedp, 1, may_share);
1710 /* Per-insn processing by fixup_var_refs_insns(_with_hash). INSN is
1711 the insn under examination, VAR is the variable to fix up
1712 references to, PROMOTED_MODE and UNSIGNEDP describe VAR, and
1713 TOPLEVEL is nonzero if this is the main insn chain for this
1717 fixup_var_refs_insn (rtx insn, rtx var, enum machine_mode promoted_mode,
1718 int unsignedp, int toplevel, rtx no_share)
1721 rtx set, prev, prev_set;
1724 /* Remember the notes in case we delete the insn. */
1725 note = REG_NOTES (insn);
1727 /* If this is a CLOBBER of VAR, delete it.
1729 If it has a REG_LIBCALL note, delete the REG_LIBCALL
1730 and REG_RETVAL notes too. */
1731 if (GET_CODE (PATTERN (insn)) == CLOBBER
1732 && (XEXP (PATTERN (insn), 0) == var
1733 || (GET_CODE (XEXP (PATTERN (insn), 0)) == CONCAT
1734 && (XEXP (XEXP (PATTERN (insn), 0), 0) == var
1735 || XEXP (XEXP (PATTERN (insn), 0), 1) == var))))
1737 if ((note = find_reg_note (insn, REG_LIBCALL, NULL_RTX)) != 0)
1738 /* The REG_LIBCALL note will go away since we are going to
1739 turn INSN into a NOTE, so just delete the
1740 corresponding REG_RETVAL note. */
1741 remove_note (XEXP (note, 0),
1742 find_reg_note (XEXP (note, 0), REG_RETVAL,
1748 /* The insn to load VAR from a home in the arglist
1749 is now a no-op. When we see it, just delete it.
1750 Similarly if this is storing VAR from a register from which
1751 it was loaded in the previous insn. This will occur
1752 when an ADDRESSOF was made for an arglist slot. */
1754 && (set = single_set (insn)) != 0
1755 && SET_DEST (set) == var
1756 /* If this represents the result of an insn group,
1757 don't delete the insn. */
1758 && find_reg_note (insn, REG_RETVAL, NULL_RTX) == 0
1759 && (rtx_equal_p (SET_SRC (set), var)
1760 || (REG_P (SET_SRC (set))
1761 && (prev = prev_nonnote_insn (insn)) != 0
1762 && (prev_set = single_set (prev)) != 0
1763 && SET_DEST (prev_set) == SET_SRC (set)
1764 && rtx_equal_p (SET_SRC (prev_set), var))))
1770 struct fixup_replacement *replacements = 0;
1771 rtx next_insn = NEXT_INSN (insn);
1773 if (SMALL_REGISTER_CLASSES)
1775 /* If the insn that copies the results of a CALL_INSN
1776 into a pseudo now references VAR, we have to use an
1777 intermediate pseudo since we want the life of the
1778 return value register to be only a single insn.
1780 If we don't use an intermediate pseudo, such things as
1781 address computations to make the address of VAR valid
1782 if it is not can be placed between the CALL_INSN and INSN.
1784 To make sure this doesn't happen, we record the destination
1785 of the CALL_INSN and see if the next insn uses both that
1788 if (call_dest != 0 && GET_CODE (insn) == INSN
1789 && reg_mentioned_p (var, PATTERN (insn))
1790 && reg_mentioned_p (call_dest, PATTERN (insn)))
1792 rtx temp = gen_reg_rtx (GET_MODE (call_dest));
1794 emit_insn_before (gen_move_insn (temp, call_dest), insn);
1796 PATTERN (insn) = replace_rtx (PATTERN (insn),
1800 if (GET_CODE (insn) == CALL_INSN
1801 && GET_CODE (PATTERN (insn)) == SET)
1802 call_dest = SET_DEST (PATTERN (insn));
1803 else if (GET_CODE (insn) == CALL_INSN
1804 && GET_CODE (PATTERN (insn)) == PARALLEL
1805 && GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == SET)
1806 call_dest = SET_DEST (XVECEXP (PATTERN (insn), 0, 0));
1811 /* See if we have to do anything to INSN now that VAR is in
1812 memory. If it needs to be loaded into a pseudo, use a single
1813 pseudo for the entire insn in case there is a MATCH_DUP
1814 between two operands. We pass a pointer to the head of
1815 a list of struct fixup_replacements. If fixup_var_refs_1
1816 needs to allocate pseudos or replacement MEMs (for SUBREGs),
1817 it will record them in this list.
1819 If it allocated a pseudo for any replacement, we copy into
1822 fixup_var_refs_1 (var, promoted_mode, &PATTERN (insn), insn,
1823 &replacements, no_share);
1825 while (replacements)
1827 struct fixup_replacement *next;
1829 if (REG_P (replacements->new))
1834 /* OLD might be a (subreg (mem)). */
1835 if (GET_CODE (replacements->old) == SUBREG)
1837 = fixup_memory_subreg (replacements->old, insn,
1841 = fixup_stack_1 (replacements->old, insn);
1843 insert_before = insn;
1845 /* If we are changing the mode, do a conversion.
1846 This might be wasteful, but combine.c will
1847 eliminate much of the waste. */
1849 if (GET_MODE (replacements->new)
1850 != GET_MODE (replacements->old))
1853 convert_move (replacements->new,
1854 replacements->old, unsignedp);
1859 seq = gen_move_insn (replacements->new,
1862 emit_insn_before (seq, insert_before);
1865 next = replacements->next;
1866 free (replacements);
1867 replacements = next;
1871 /* Also fix up any invalid exprs in the REG_NOTES of this insn.
1872 But don't touch other insns referred to by reg-notes;
1873 we will get them elsewhere. */
1876 if (GET_CODE (note) != INSN_LIST)
1878 = walk_fixup_memory_subreg (XEXP (note, 0), insn, var,
1880 note = XEXP (note, 1);
1884 /* VAR is a MEM that used to be a pseudo register with mode PROMOTED_MODE.
1885 See if the rtx expression at *LOC in INSN needs to be changed.
1887 REPLACEMENTS is a pointer to a list head that starts out zero, but may
1888 contain a list of original rtx's and replacements. If we find that we need
1889 to modify this insn by replacing a memory reference with a pseudo or by
1890 making a new MEM to implement a SUBREG, we consult that list to see if
1891 we have already chosen a replacement. If none has already been allocated,
1892 we allocate it and update the list. fixup_var_refs_insn will copy VAR
1893 or the SUBREG, as appropriate, to the pseudo. */
1896 fixup_var_refs_1 (rtx var, enum machine_mode promoted_mode, rtx *loc, rtx insn,
1897 struct fixup_replacement **replacements, rtx no_share)
1901 RTX_CODE code = GET_CODE (x);
1904 struct fixup_replacement *replacement;
1909 if (XEXP (x, 0) == var)
1911 /* Prevent sharing of rtl that might lose. */
1912 rtx sub = copy_rtx (XEXP (var, 0));
1914 if (! validate_change (insn, loc, sub, 0))
1916 rtx y = gen_reg_rtx (GET_MODE (sub));
1919 /* We should be able to replace with a register or all is lost.
1920 Note that we can't use validate_change to verify this, since
1921 we're not caring for replacing all dups simultaneously. */
1922 if (! validate_replace_rtx (*loc, y, insn))
1925 /* Careful! First try to recognize a direct move of the
1926 value, mimicking how things are done in gen_reload wrt
1927 PLUS. Consider what happens when insn is a conditional
1928 move instruction and addsi3 clobbers flags. */
1931 new_insn = emit_insn (gen_rtx_SET (VOIDmode, y, sub));
1935 if (recog_memoized (new_insn) < 0)
1937 /* That failed. Fall back on force_operand and hope. */
1940 sub = force_operand (sub, y);
1942 emit_insn (gen_move_insn (y, sub));
1948 /* Don't separate setter from user. */
1949 if (PREV_INSN (insn) && sets_cc0_p (PREV_INSN (insn)))
1950 insn = PREV_INSN (insn);
1953 emit_insn_before (seq, insn);
1961 /* If we already have a replacement, use it. Otherwise,
1962 try to fix up this address in case it is invalid. */
1964 replacement = find_fixup_replacement (replacements, var);
1965 if (replacement->new)
1967 *loc = replacement->new;
1971 *loc = replacement->new = x = fixup_stack_1 (x, insn);
1973 /* Unless we are forcing memory to register or we changed the mode,
1974 we can leave things the way they are if the insn is valid. */
1976 INSN_CODE (insn) = -1;
1977 if (! flag_force_mem && GET_MODE (x) == promoted_mode
1978 && recog_memoized (insn) >= 0)
1981 *loc = replacement->new = gen_reg_rtx (promoted_mode);
1985 /* If X contains VAR, we need to unshare it here so that we update
1986 each occurrence separately. But all identical MEMs in one insn
1987 must be replaced with the same rtx because of the possibility of
1990 if (reg_mentioned_p (var, x))
1992 replacement = find_fixup_replacement (replacements, x);
1993 if (replacement->new == 0)
1994 replacement->new = copy_most_rtx (x, no_share);
1996 *loc = x = replacement->new;
1997 code = GET_CODE (x);
2014 /* Note that in some cases those types of expressions are altered
2015 by optimize_bit_field, and do not survive to get here. */
2016 if (XEXP (x, 0) == var
2017 || (GET_CODE (XEXP (x, 0)) == SUBREG
2018 && SUBREG_REG (XEXP (x, 0)) == var))
2020 /* Get TEM as a valid MEM in the mode presently in the insn.
2022 We don't worry about the possibility of MATCH_DUP here; it
2023 is highly unlikely and would be tricky to handle. */
2026 if (GET_CODE (tem) == SUBREG)
2028 if (GET_MODE_BITSIZE (GET_MODE (tem))
2029 > GET_MODE_BITSIZE (GET_MODE (var)))
2031 replacement = find_fixup_replacement (replacements, var);
2032 if (replacement->new == 0)
2033 replacement->new = gen_reg_rtx (GET_MODE (var));
2034 SUBREG_REG (tem) = replacement->new;
2036 /* The following code works only if we have a MEM, so we
2037 need to handle the subreg here. We directly substitute
2038 it assuming that a subreg must be OK here. We already
2039 scheduled a replacement to copy the mem into the
2045 tem = fixup_memory_subreg (tem, insn, promoted_mode, 0);
2048 tem = fixup_stack_1 (tem, insn);
2050 /* Unless we want to load from memory, get TEM into the proper mode
2051 for an extract from memory. This can only be done if the
2052 extract is at a constant position and length. */
2054 if (! flag_force_mem && GET_CODE (XEXP (x, 1)) == CONST_INT
2055 && GET_CODE (XEXP (x, 2)) == CONST_INT
2056 && ! mode_dependent_address_p (XEXP (tem, 0))
2057 && ! MEM_VOLATILE_P (tem))
2059 enum machine_mode wanted_mode = VOIDmode;
2060 enum machine_mode is_mode = GET_MODE (tem);
2061 HOST_WIDE_INT pos = INTVAL (XEXP (x, 2));
2063 if (GET_CODE (x) == ZERO_EXTRACT)
2065 enum machine_mode new_mode
2066 = mode_for_extraction (EP_extzv, 1);
2067 if (new_mode != MAX_MACHINE_MODE)
2068 wanted_mode = new_mode;
2070 else if (GET_CODE (x) == SIGN_EXTRACT)
2072 enum machine_mode new_mode
2073 = mode_for_extraction (EP_extv, 1);
2074 if (new_mode != MAX_MACHINE_MODE)
2075 wanted_mode = new_mode;
2078 /* If we have a narrower mode, we can do something. */
2079 if (wanted_mode != VOIDmode
2080 && GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
2082 HOST_WIDE_INT offset = pos / BITS_PER_UNIT;
2083 rtx old_pos = XEXP (x, 2);
2086 /* If the bytes and bits are counted differently, we
2087 must adjust the offset. */
2088 if (BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN)
2089 offset = (GET_MODE_SIZE (is_mode)
2090 - GET_MODE_SIZE (wanted_mode) - offset);
2092 pos %= GET_MODE_BITSIZE (wanted_mode);
2094 newmem = adjust_address_nv (tem, wanted_mode, offset);
2096 /* Make the change and see if the insn remains valid. */
2097 INSN_CODE (insn) = -1;
2098 XEXP (x, 0) = newmem;
2099 XEXP (x, 2) = GEN_INT (pos);
2101 if (recog_memoized (insn) >= 0)
2104 /* Otherwise, restore old position. XEXP (x, 0) will be
2106 XEXP (x, 2) = old_pos;
2110 /* If we get here, the bitfield extract insn can't accept a memory
2111 reference. Copy the input into a register. */
2113 tem1 = gen_reg_rtx (GET_MODE (tem));
2114 emit_insn_before (gen_move_insn (tem1, tem), insn);
2121 if (SUBREG_REG (x) == var)
2123 /* If this is a special SUBREG made because VAR was promoted
2124 from a wider mode, replace it with VAR and call ourself
2125 recursively, this time saying that the object previously
2126 had its current mode (by virtue of the SUBREG). */
2128 if (SUBREG_PROMOTED_VAR_P (x))
2131 fixup_var_refs_1 (var, GET_MODE (var), loc, insn, replacements,
2136 /* If this SUBREG makes VAR wider, it has become a paradoxical
2137 SUBREG with VAR in memory, but these aren't allowed at this
2138 stage of the compilation. So load VAR into a pseudo and take
2139 a SUBREG of that pseudo. */
2140 if (GET_MODE_SIZE (GET_MODE (x)) > GET_MODE_SIZE (GET_MODE (var)))
2142 replacement = find_fixup_replacement (replacements, var);
2143 if (replacement->new == 0)
2144 replacement->new = gen_reg_rtx (promoted_mode);
2145 SUBREG_REG (x) = replacement->new;
2149 /* See if we have already found a replacement for this SUBREG.
2150 If so, use it. Otherwise, make a MEM and see if the insn
2151 is recognized. If not, or if we should force MEM into a register,
2152 make a pseudo for this SUBREG. */
2153 replacement = find_fixup_replacement (replacements, x);
2154 if (replacement->new)
2156 enum machine_mode mode = GET_MODE (x);
2157 *loc = replacement->new;
2159 /* Careful! We may have just replaced a SUBREG by a MEM, which
2160 means that the insn may have become invalid again. We can't
2161 in this case make a new replacement since we already have one
2162 and we must deal with MATCH_DUPs. */
2163 if (GET_CODE (replacement->new) == MEM)
2165 INSN_CODE (insn) = -1;
2166 if (recog_memoized (insn) >= 0)
2169 fixup_var_refs_1 (replacement->new, mode, &PATTERN (insn),
2170 insn, replacements, no_share);
2176 replacement->new = *loc = fixup_memory_subreg (x, insn,
2179 INSN_CODE (insn) = -1;
2180 if (! flag_force_mem && recog_memoized (insn) >= 0)
2183 *loc = replacement->new = gen_reg_rtx (GET_MODE (x));
2189 /* First do special simplification of bit-field references. */
2190 if (GET_CODE (SET_DEST (x)) == SIGN_EXTRACT
2191 || GET_CODE (SET_DEST (x)) == ZERO_EXTRACT)
2192 optimize_bit_field (x, insn, 0);
2193 if (GET_CODE (SET_SRC (x)) == SIGN_EXTRACT
2194 || GET_CODE (SET_SRC (x)) == ZERO_EXTRACT)
2195 optimize_bit_field (x, insn, 0);
2197 /* For a paradoxical SUBREG inside a ZERO_EXTRACT, load the object
2198 into a register and then store it back out. */
2199 if (GET_CODE (SET_DEST (x)) == ZERO_EXTRACT
2200 && GET_CODE (XEXP (SET_DEST (x), 0)) == SUBREG
2201 && SUBREG_REG (XEXP (SET_DEST (x), 0)) == var
2202 && (GET_MODE_SIZE (GET_MODE (XEXP (SET_DEST (x), 0)))
2203 > GET_MODE_SIZE (GET_MODE (var))))
2205 replacement = find_fixup_replacement (replacements, var);
2206 if (replacement->new == 0)
2207 replacement->new = gen_reg_rtx (GET_MODE (var));
2209 SUBREG_REG (XEXP (SET_DEST (x), 0)) = replacement->new;
2210 emit_insn_after (gen_move_insn (var, replacement->new), insn);
2213 /* If SET_DEST is now a paradoxical SUBREG, put the result of this
2214 insn into a pseudo and store the low part of the pseudo into VAR. */
2215 if (GET_CODE (SET_DEST (x)) == SUBREG
2216 && SUBREG_REG (SET_DEST (x)) == var
2217 && (GET_MODE_SIZE (GET_MODE (SET_DEST (x)))
2218 > GET_MODE_SIZE (GET_MODE (var))))
2220 SET_DEST (x) = tem = gen_reg_rtx (GET_MODE (SET_DEST (x)));
2221 emit_insn_after (gen_move_insn (var, gen_lowpart (GET_MODE (var),
2228 rtx dest = SET_DEST (x);
2229 rtx src = SET_SRC (x);
2230 rtx outerdest = dest;
2232 while (GET_CODE (dest) == SUBREG || GET_CODE (dest) == STRICT_LOW_PART
2233 || GET_CODE (dest) == SIGN_EXTRACT
2234 || GET_CODE (dest) == ZERO_EXTRACT)
2235 dest = XEXP (dest, 0);
2237 if (GET_CODE (src) == SUBREG)
2238 src = SUBREG_REG (src);
2240 /* If VAR does not appear at the top level of the SET
2241 just scan the lower levels of the tree. */
2243 if (src != var && dest != var)
2246 /* We will need to rerecognize this insn. */
2247 INSN_CODE (insn) = -1;
2249 if (GET_CODE (outerdest) == ZERO_EXTRACT && dest == var
2250 && mode_for_extraction (EP_insv, -1) != MAX_MACHINE_MODE)
2252 /* Since this case will return, ensure we fixup all the
2254 fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 1),
2255 insn, replacements, no_share);
2256 fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 2),
2257 insn, replacements, no_share);
2258 fixup_var_refs_1 (var, promoted_mode, &SET_SRC (x),
2259 insn, replacements, no_share);
2261 tem = XEXP (outerdest, 0);
2263 /* Clean up (SUBREG:SI (MEM:mode ...) 0)
2264 that may appear inside a ZERO_EXTRACT.
2265 This was legitimate when the MEM was a REG. */
2266 if (GET_CODE (tem) == SUBREG
2267 && SUBREG_REG (tem) == var)
2268 tem = fixup_memory_subreg (tem, insn, promoted_mode, 0);
2270 tem = fixup_stack_1 (tem, insn);
2272 if (GET_CODE (XEXP (outerdest, 1)) == CONST_INT
2273 && GET_CODE (XEXP (outerdest, 2)) == CONST_INT
2274 && ! mode_dependent_address_p (XEXP (tem, 0))
2275 && ! MEM_VOLATILE_P (tem))
2277 enum machine_mode wanted_mode;
2278 enum machine_mode is_mode = GET_MODE (tem);
2279 HOST_WIDE_INT pos = INTVAL (XEXP (outerdest, 2));
2281 wanted_mode = mode_for_extraction (EP_insv, 0);
2283 /* If we have a narrower mode, we can do something. */
2284 if (GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
2286 HOST_WIDE_INT offset = pos / BITS_PER_UNIT;
2287 rtx old_pos = XEXP (outerdest, 2);
2290 if (BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN)
2291 offset = (GET_MODE_SIZE (is_mode)
2292 - GET_MODE_SIZE (wanted_mode) - offset);
2294 pos %= GET_MODE_BITSIZE (wanted_mode);
2296 newmem = adjust_address_nv (tem, wanted_mode, offset);
2298 /* Make the change and see if the insn remains valid. */
2299 INSN_CODE (insn) = -1;
2300 XEXP (outerdest, 0) = newmem;
2301 XEXP (outerdest, 2) = GEN_INT (pos);
2303 if (recog_memoized (insn) >= 0)
2306 /* Otherwise, restore old position. XEXP (x, 0) will be
2308 XEXP (outerdest, 2) = old_pos;
2312 /* If we get here, the bit-field store doesn't allow memory
2313 or isn't located at a constant position. Load the value into
2314 a register, do the store, and put it back into memory. */
2316 tem1 = gen_reg_rtx (GET_MODE (tem));
2317 emit_insn_before (gen_move_insn (tem1, tem), insn);
2318 emit_insn_after (gen_move_insn (tem, tem1), insn);
2319 XEXP (outerdest, 0) = tem1;
2323 /* STRICT_LOW_PART is a no-op on memory references
2324 and it can cause combinations to be unrecognizable,
2327 if (dest == var && GET_CODE (SET_DEST (x)) == STRICT_LOW_PART)
2328 SET_DEST (x) = XEXP (SET_DEST (x), 0);
2330 /* A valid insn to copy VAR into or out of a register
2331 must be left alone, to avoid an infinite loop here.
2332 If the reference to VAR is by a subreg, fix that up,
2333 since SUBREG is not valid for a memref.
2334 Also fix up the address of the stack slot.
2336 Note that we must not try to recognize the insn until
2337 after we know that we have valid addresses and no
2338 (subreg (mem ...) ...) constructs, since these interfere
2339 with determining the validity of the insn. */
2341 if ((SET_SRC (x) == var
2342 || (GET_CODE (SET_SRC (x)) == SUBREG
2343 && SUBREG_REG (SET_SRC (x)) == var))
2344 && (REG_P (SET_DEST (x))
2345 || (GET_CODE (SET_DEST (x)) == SUBREG
2346 && REG_P (SUBREG_REG (SET_DEST (x)))))
2347 && GET_MODE (var) == promoted_mode
2348 && x == single_set (insn))
2352 if (GET_CODE (SET_SRC (x)) == SUBREG
2353 && (GET_MODE_SIZE (GET_MODE (SET_SRC (x)))
2354 > GET_MODE_SIZE (GET_MODE (var))))
2356 /* This (subreg VAR) is now a paradoxical subreg. We need
2357 to replace VAR instead of the subreg. */
2358 replacement = find_fixup_replacement (replacements, var);
2359 if (replacement->new == NULL_RTX)
2360 replacement->new = gen_reg_rtx (GET_MODE (var));
2361 SUBREG_REG (SET_SRC (x)) = replacement->new;
2365 replacement = find_fixup_replacement (replacements, SET_SRC (x));
2366 if (replacement->new)
2367 SET_SRC (x) = replacement->new;
2368 else if (GET_CODE (SET_SRC (x)) == SUBREG)
2369 SET_SRC (x) = replacement->new
2370 = fixup_memory_subreg (SET_SRC (x), insn, promoted_mode,
2373 SET_SRC (x) = replacement->new
2374 = fixup_stack_1 (SET_SRC (x), insn);
2377 if (recog_memoized (insn) >= 0)
2380 /* INSN is not valid, but we know that we want to
2381 copy SET_SRC (x) to SET_DEST (x) in some way. So
2382 we generate the move and see whether it requires more
2383 than one insn. If it does, we emit those insns and
2384 delete INSN. Otherwise, we can just replace the pattern
2385 of INSN; we have already verified above that INSN has
2386 no other function that to do X. */
2388 pat = gen_move_insn (SET_DEST (x), SET_SRC (x));
2389 if (NEXT_INSN (pat) != NULL_RTX)
2391 last = emit_insn_before (pat, insn);
2393 /* INSN might have REG_RETVAL or other important notes, so
2394 we need to store the pattern of the last insn in the
2395 sequence into INSN similarly to the normal case. LAST
2396 should not have REG_NOTES, but we allow them if INSN has
2398 if (REG_NOTES (last) && REG_NOTES (insn))
2400 if (REG_NOTES (last))
2401 REG_NOTES (insn) = REG_NOTES (last);
2402 PATTERN (insn) = PATTERN (last);
2407 PATTERN (insn) = PATTERN (pat);
2412 if ((SET_DEST (x) == var
2413 || (GET_CODE (SET_DEST (x)) == SUBREG
2414 && SUBREG_REG (SET_DEST (x)) == var))
2415 && (REG_P (SET_SRC (x))
2416 || (GET_CODE (SET_SRC (x)) == SUBREG
2417 && REG_P (SUBREG_REG (SET_SRC (x)))))
2418 && GET_MODE (var) == promoted_mode
2419 && x == single_set (insn))
2423 if (GET_CODE (SET_DEST (x)) == SUBREG)
2424 SET_DEST (x) = fixup_memory_subreg (SET_DEST (x), insn,
2427 SET_DEST (x) = fixup_stack_1 (SET_DEST (x), insn);
2429 if (recog_memoized (insn) >= 0)
2432 pat = gen_move_insn (SET_DEST (x), SET_SRC (x));
2433 if (NEXT_INSN (pat) != NULL_RTX)
2435 last = emit_insn_before (pat, insn);
2437 /* INSN might have REG_RETVAL or other important notes, so
2438 we need to store the pattern of the last insn in the
2439 sequence into INSN similarly to the normal case. LAST
2440 should not have REG_NOTES, but we allow them if INSN has
2442 if (REG_NOTES (last) && REG_NOTES (insn))
2444 if (REG_NOTES (last))
2445 REG_NOTES (insn) = REG_NOTES (last);
2446 PATTERN (insn) = PATTERN (last);
2451 PATTERN (insn) = PATTERN (pat);
2456 /* Otherwise, storing into VAR must be handled specially
2457 by storing into a temporary and copying that into VAR
2458 with a new insn after this one. Note that this case
2459 will be used when storing into a promoted scalar since
2460 the insn will now have different modes on the input
2461 and output and hence will be invalid (except for the case
2462 of setting it to a constant, which does not need any
2463 change if it is valid). We generate extra code in that case,
2464 but combine.c will eliminate it. */
2469 rtx fixeddest = SET_DEST (x);
2470 enum machine_mode temp_mode;
2472 /* STRICT_LOW_PART can be discarded, around a MEM. */
2473 if (GET_CODE (fixeddest) == STRICT_LOW_PART)
2474 fixeddest = XEXP (fixeddest, 0);
2475 /* Convert (SUBREG (MEM)) to a MEM in a changed mode. */
2476 if (GET_CODE (fixeddest) == SUBREG)
2478 fixeddest = fixup_memory_subreg (fixeddest, insn,
2480 temp_mode = GET_MODE (fixeddest);
2484 fixeddest = fixup_stack_1 (fixeddest, insn);
2485 temp_mode = promoted_mode;
2488 temp = gen_reg_rtx (temp_mode);
2490 emit_insn_after (gen_move_insn (fixeddest,
2491 gen_lowpart (GET_MODE (fixeddest),
2495 SET_DEST (x) = temp;
2503 /* Nothing special about this RTX; fix its operands. */
2505 fmt = GET_RTX_FORMAT (code);
2506 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2509 fixup_var_refs_1 (var, promoted_mode, &XEXP (x, i), insn, replacements,
2511 else if (fmt[i] == 'E')
2514 for (j = 0; j < XVECLEN (x, i); j++)
2515 fixup_var_refs_1 (var, promoted_mode, &XVECEXP (x, i, j),
2516 insn, replacements, no_share);
2521 /* Previously, X had the form (SUBREG:m1 (REG:PROMOTED_MODE ...)).
2522 The REG was placed on the stack, so X now has the form (SUBREG:m1
2525 Return an rtx (MEM:m1 newaddr) which is equivalent. If any insns
2526 must be emitted to compute NEWADDR, put them before INSN.
2528 UNCRITICAL nonzero means accept paradoxical subregs.
2529 This is used for subregs found inside REG_NOTES. */
2532 fixup_memory_subreg (rtx x, rtx insn, enum machine_mode promoted_mode, int uncritical)
2535 rtx mem = SUBREG_REG (x);
2536 rtx addr = XEXP (mem, 0);
2537 enum machine_mode mode = GET_MODE (x);
2540 /* Paradoxical SUBREGs are usually invalid during RTL generation. */
2541 if (GET_MODE_SIZE (mode) > GET_MODE_SIZE (GET_MODE (mem)) && ! uncritical)
2544 offset = SUBREG_BYTE (x);
2545 if (BYTES_BIG_ENDIAN)
2546 /* If the PROMOTED_MODE is wider than the mode of the MEM, adjust
2547 the offset so that it points to the right location within the
2549 offset -= (GET_MODE_SIZE (promoted_mode) - GET_MODE_SIZE (GET_MODE (mem)));
2551 if (!flag_force_addr
2552 && memory_address_p (mode, plus_constant (addr, offset)))
2553 /* Shortcut if no insns need be emitted. */
2554 return adjust_address (mem, mode, offset);
2557 result = adjust_address (mem, mode, offset);
2561 emit_insn_before (seq, insn);
2565 /* Do fixup_memory_subreg on all (SUBREG (VAR) ...) contained in X.
2566 VAR is a MEM that used to be a pseudo register with mode PROMOTED_MODE.
2567 Replace subexpressions of X in place.
2568 If X itself is a (SUBREG (VAR) ...), return the replacement expression.
2569 Otherwise return X, with its contents possibly altered.
2571 INSN and UNCRITICAL are as for fixup_memory_subreg. */
2574 walk_fixup_memory_subreg (rtx x, rtx insn, rtx var,
2575 enum machine_mode promoted_mode, int uncritical)
2584 code = GET_CODE (x);
2586 if (code == SUBREG && SUBREG_REG (x) == var)
2587 return fixup_memory_subreg (x, insn, promoted_mode, uncritical);
2589 /* Nothing special about this RTX; fix its operands. */
2591 fmt = GET_RTX_FORMAT (code);
2592 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2595 XEXP (x, i) = walk_fixup_memory_subreg (XEXP (x, i), insn, var,
2596 promoted_mode, uncritical);
2597 else if (fmt[i] == 'E')
2600 for (j = 0; j < XVECLEN (x, i); j++)
2602 = walk_fixup_memory_subreg (XVECEXP (x, i, j), insn, var,
2603 promoted_mode, uncritical);
2609 /* For each memory ref within X, if it refers to a stack slot
2610 with an out of range displacement, put the address in a temp register
2611 (emitting new insns before INSN to load these registers)
2612 and alter the memory ref to use that register.
2613 Replace each such MEM rtx with a copy, to avoid clobberage. */
2616 fixup_stack_1 (rtx x, rtx insn)
2619 RTX_CODE code = GET_CODE (x);
2624 rtx ad = XEXP (x, 0);
2625 /* If we have address of a stack slot but it's not valid
2626 (displacement is too large), compute the sum in a register. */
2627 if (GET_CODE (ad) == PLUS
2628 && REG_P (XEXP (ad, 0))
2629 && ((REGNO (XEXP (ad, 0)) >= FIRST_VIRTUAL_REGISTER
2630 && REGNO (XEXP (ad, 0)) <= LAST_VIRTUAL_REGISTER)
2631 || REGNO (XEXP (ad, 0)) == FRAME_POINTER_REGNUM
2632 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
2633 || REGNO (XEXP (ad, 0)) == HARD_FRAME_POINTER_REGNUM
2635 || REGNO (XEXP (ad, 0)) == STACK_POINTER_REGNUM
2636 || REGNO (XEXP (ad, 0)) == ARG_POINTER_REGNUM
2637 || XEXP (ad, 0) == current_function_internal_arg_pointer)
2638 && GET_CODE (XEXP (ad, 1)) == CONST_INT)
2641 if (memory_address_p (GET_MODE (x), ad))
2645 temp = copy_to_reg (ad);
2648 emit_insn_before (seq, insn);
2649 return replace_equiv_address (x, temp);
2654 fmt = GET_RTX_FORMAT (code);
2655 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2658 XEXP (x, i) = fixup_stack_1 (XEXP (x, i), insn);
2659 else if (fmt[i] == 'E')
2662 for (j = 0; j < XVECLEN (x, i); j++)
2663 XVECEXP (x, i, j) = fixup_stack_1 (XVECEXP (x, i, j), insn);
2669 /* Optimization: a bit-field instruction whose field
2670 happens to be a byte or halfword in memory
2671 can be changed to a move instruction.
2673 We call here when INSN is an insn to examine or store into a bit-field.
2674 BODY is the SET-rtx to be altered.
2676 EQUIV_MEM is the table `reg_equiv_mem' if that is available; else 0.
2677 (Currently this is called only from function.c, and EQUIV_MEM
2681 optimize_bit_field (rtx body, rtx insn, rtx *equiv_mem)
2686 enum machine_mode mode;
2688 if (GET_CODE (SET_DEST (body)) == SIGN_EXTRACT
2689 || GET_CODE (SET_DEST (body)) == ZERO_EXTRACT)
2690 bitfield = SET_DEST (body), destflag = 1;
2692 bitfield = SET_SRC (body), destflag = 0;
2694 /* First check that the field being stored has constant size and position
2695 and is in fact a byte or halfword suitably aligned. */
2697 if (GET_CODE (XEXP (bitfield, 1)) == CONST_INT
2698 && GET_CODE (XEXP (bitfield, 2)) == CONST_INT
2699 && ((mode = mode_for_size (INTVAL (XEXP (bitfield, 1)), MODE_INT, 1))
2701 && INTVAL (XEXP (bitfield, 2)) % INTVAL (XEXP (bitfield, 1)) == 0)
2705 /* Now check that the containing word is memory, not a register,
2706 and that it is safe to change the machine mode. */
2708 if (GET_CODE (XEXP (bitfield, 0)) == MEM)
2709 memref = XEXP (bitfield, 0);
2710 else if (REG_P (XEXP (bitfield, 0))
2712 memref = equiv_mem[REGNO (XEXP (bitfield, 0))];
2713 else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
2714 && GET_CODE (SUBREG_REG (XEXP (bitfield, 0))) == MEM)
2715 memref = SUBREG_REG (XEXP (bitfield, 0));
2716 else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
2718 && REG_P (SUBREG_REG (XEXP (bitfield, 0))))
2719 memref = equiv_mem[REGNO (SUBREG_REG (XEXP (bitfield, 0)))];
2722 && ! mode_dependent_address_p (XEXP (memref, 0))
2723 && ! MEM_VOLATILE_P (memref))
2725 /* Now adjust the address, first for any subreg'ing
2726 that we are now getting rid of,
2727 and then for which byte of the word is wanted. */
2729 HOST_WIDE_INT offset = INTVAL (XEXP (bitfield, 2));
2732 /* Adjust OFFSET to count bits from low-address byte. */
2733 if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN)
2734 offset = (GET_MODE_BITSIZE (GET_MODE (XEXP (bitfield, 0)))
2735 - offset - INTVAL (XEXP (bitfield, 1)));
2737 /* Adjust OFFSET to count bytes from low-address byte. */
2738 offset /= BITS_PER_UNIT;
2739 if (GET_CODE (XEXP (bitfield, 0)) == SUBREG)
2741 offset += (SUBREG_BYTE (XEXP (bitfield, 0))
2742 / UNITS_PER_WORD) * UNITS_PER_WORD;
2743 if (BYTES_BIG_ENDIAN)
2744 offset -= (MIN (UNITS_PER_WORD,
2745 GET_MODE_SIZE (GET_MODE (XEXP (bitfield, 0))))
2746 - MIN (UNITS_PER_WORD,
2747 GET_MODE_SIZE (GET_MODE (memref))));
2751 memref = adjust_address (memref, mode, offset);
2752 insns = get_insns ();
2754 emit_insn_before (insns, insn);
2756 /* Store this memory reference where
2757 we found the bit field reference. */
2761 validate_change (insn, &SET_DEST (body), memref, 1);
2762 if (! CONSTANT_ADDRESS_P (SET_SRC (body)))
2764 rtx src = SET_SRC (body);
2765 while (GET_CODE (src) == SUBREG
2766 && SUBREG_BYTE (src) == 0)
2767 src = SUBREG_REG (src);
2768 if (GET_MODE (src) != GET_MODE (memref))
2769 src = gen_lowpart (GET_MODE (memref), SET_SRC (body));
2770 validate_change (insn, &SET_SRC (body), src, 1);
2772 else if (GET_MODE (SET_SRC (body)) != VOIDmode
2773 && GET_MODE (SET_SRC (body)) != GET_MODE (memref))
2774 /* This shouldn't happen because anything that didn't have
2775 one of these modes should have got converted explicitly
2776 and then referenced through a subreg.
2777 This is so because the original bit-field was
2778 handled by agg_mode and so its tree structure had
2779 the same mode that memref now has. */
2784 rtx dest = SET_DEST (body);
2786 while (GET_CODE (dest) == SUBREG
2787 && SUBREG_BYTE (dest) == 0
2788 && (GET_MODE_CLASS (GET_MODE (dest))
2789 == GET_MODE_CLASS (GET_MODE (SUBREG_REG (dest))))
2790 && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest)))
2792 dest = SUBREG_REG (dest);
2794 validate_change (insn, &SET_DEST (body), dest, 1);
2796 if (GET_MODE (dest) == GET_MODE (memref))
2797 validate_change (insn, &SET_SRC (body), memref, 1);
2800 /* Convert the mem ref to the destination mode. */
2801 rtx newreg = gen_reg_rtx (GET_MODE (dest));
2804 convert_move (newreg, memref,
2805 GET_CODE (SET_SRC (body)) == ZERO_EXTRACT);
2809 validate_change (insn, &SET_SRC (body), newreg, 1);
2813 /* See if we can convert this extraction or insertion into
2814 a simple move insn. We might not be able to do so if this
2815 was, for example, part of a PARALLEL.
2817 If we succeed, write out any needed conversions. If we fail,
2818 it is hard to guess why we failed, so don't do anything
2819 special; just let the optimization be suppressed. */
2821 if (apply_change_group () && seq)
2822 emit_insn_before (seq, insn);
2827 /* These routines are responsible for converting virtual register references
2828 to the actual hard register references once RTL generation is complete.
2830 The following four variables are used for communication between the
2831 routines. They contain the offsets of the virtual registers from their
2832 respective hard registers. */
2834 static int in_arg_offset;
2835 static int var_offset;
2836 static int dynamic_offset;
2837 static int out_arg_offset;
2838 static int cfa_offset;
2840 /* In most machines, the stack pointer register is equivalent to the bottom
2843 #ifndef STACK_POINTER_OFFSET
2844 #define STACK_POINTER_OFFSET 0
2847 /* If not defined, pick an appropriate default for the offset of dynamically
2848 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
2849 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
2851 #ifndef STACK_DYNAMIC_OFFSET
2853 /* The bottom of the stack points to the actual arguments. If
2854 REG_PARM_STACK_SPACE is defined, this includes the space for the register
2855 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
2856 stack space for register parameters is not pushed by the caller, but
2857 rather part of the fixed stack areas and hence not included in
2858 `current_function_outgoing_args_size'. Nevertheless, we must allow
2859 for it when allocating stack dynamic objects. */
2861 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
2862 #define STACK_DYNAMIC_OFFSET(FNDECL) \
2863 ((ACCUMULATE_OUTGOING_ARGS \
2864 ? (current_function_outgoing_args_size + REG_PARM_STACK_SPACE (FNDECL)) : 0)\
2865 + (STACK_POINTER_OFFSET)) \
2868 #define STACK_DYNAMIC_OFFSET(FNDECL) \
2869 ((ACCUMULATE_OUTGOING_ARGS ? current_function_outgoing_args_size : 0) \
2870 + (STACK_POINTER_OFFSET))
2874 /* On most machines, the CFA coincides with the first incoming parm. */
2876 #ifndef ARG_POINTER_CFA_OFFSET
2877 #define ARG_POINTER_CFA_OFFSET(FNDECL) FIRST_PARM_OFFSET (FNDECL)
2880 /* Build up a (MEM (ADDRESSOF (REG))) rtx for a register REG that just
2881 had its address taken. DECL is the decl or SAVE_EXPR for the
2882 object stored in the register, for later use if we do need to force
2883 REG into the stack. REG is overwritten by the MEM like in
2884 put_reg_into_stack. RESCAN is true if previously emitted
2885 instructions must be rescanned and modified now that the REG has
2886 been transformed. */
2889 gen_mem_addressof (rtx reg, tree decl, int rescan)
2891 rtx r = gen_rtx_ADDRESSOF (Pmode, gen_reg_rtx (GET_MODE (reg)),
2894 /* Calculate this before we start messing with decl's RTL. */
2895 HOST_WIDE_INT set = decl ? get_alias_set (decl) : 0;
2897 /* If the original REG was a user-variable, then so is the REG whose
2898 address is being taken. Likewise for unchanging. */
2899 REG_USERVAR_P (XEXP (r, 0)) = REG_USERVAR_P (reg);
2900 RTX_UNCHANGING_P (XEXP (r, 0)) = RTX_UNCHANGING_P (reg);
2902 PUT_CODE (reg, MEM);
2903 MEM_VOLATILE_P (reg) = 0;
2904 MEM_ATTRS (reg) = 0;
2909 tree type = TREE_TYPE (decl);
2910 enum machine_mode decl_mode
2911 = (DECL_P (decl) ? DECL_MODE (decl) : TYPE_MODE (TREE_TYPE (decl)));
2912 rtx decl_rtl = (TREE_CODE (decl) == SAVE_EXPR ? SAVE_EXPR_RTL (decl)
2913 : DECL_RTL_IF_SET (decl));
2915 PUT_MODE (reg, decl_mode);
2917 /* Clear DECL_RTL momentarily so functions below will work
2918 properly, then set it again. */
2919 if (DECL_P (decl) && decl_rtl == reg)
2920 SET_DECL_RTL (decl, 0);
2922 set_mem_attributes (reg, decl, 1);
2923 set_mem_alias_set (reg, set);
2925 if (DECL_P (decl) && decl_rtl == reg)
2926 SET_DECL_RTL (decl, reg);
2929 && (TREE_USED (decl) || (DECL_P (decl) && DECL_INITIAL (decl) != 0)))
2930 fixup_var_refs (reg, GET_MODE (reg), TYPE_UNSIGNED (type), reg, 0);
2934 /* This can only happen during reload. Clear the same flag bits as
2936 RTX_UNCHANGING_P (reg) = 0;
2937 MEM_IN_STRUCT_P (reg) = 0;
2938 MEM_SCALAR_P (reg) = 0;
2940 fixup_var_refs (reg, GET_MODE (reg), 0, reg, 0);
2946 /* If DECL has an RTL that is an ADDRESSOF rtx, put it into the stack. */
2949 flush_addressof (tree decl)
2951 if ((TREE_CODE (decl) == PARM_DECL || TREE_CODE (decl) == VAR_DECL)
2952 && DECL_RTL (decl) != 0
2953 && GET_CODE (DECL_RTL (decl)) == MEM
2954 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == ADDRESSOF
2955 && REG_P (XEXP (XEXP (DECL_RTL (decl), 0), 0)))
2956 put_addressof_into_stack (XEXP (DECL_RTL (decl), 0), 0);
2959 /* Force the register pointed to by R, an ADDRESSOF rtx, into the stack. */
2962 put_addressof_into_stack (rtx r, htab_t ht)
2965 bool volatile_p, used_p;
2967 rtx reg = XEXP (r, 0);
2972 decl = ADDRESSOF_DECL (r);
2975 type = TREE_TYPE (decl);
2976 volatile_p = (TREE_CODE (decl) != SAVE_EXPR
2977 && TREE_THIS_VOLATILE (decl));
2978 used_p = (TREE_USED (decl)
2979 || (DECL_P (decl) && DECL_INITIAL (decl) != 0));
2988 put_reg_into_stack (0, reg, type, GET_MODE (reg), ADDRESSOF_REGNO (r),
2989 volatile_p, used_p, false, ht);
2992 /* List of replacements made below in purge_addressof_1 when creating
2993 bitfield insertions. */
2994 static rtx purge_bitfield_addressof_replacements;
2996 /* List of replacements made below in purge_addressof_1 for patterns
2997 (MEM (ADDRESSOF (REG ...))). The key of the list entry is the
2998 corresponding (ADDRESSOF (REG ...)) and value is a substitution for
2999 the all pattern. List PURGE_BITFIELD_ADDRESSOF_REPLACEMENTS is not
3000 enough in complex cases, e.g. when some field values can be
3001 extracted by usage MEM with narrower mode. */
3002 static rtx purge_addressof_replacements;
3004 /* Helper function for purge_addressof. See if the rtx expression at *LOC
3005 in INSN needs to be changed. If FORCE, always put any ADDRESSOFs into
3006 the stack. If the function returns FALSE then the replacement could not
3007 be made. If MAY_POSTPONE is true and we would not put the addressof
3008 to stack, postpone processing of the insn. */
3011 purge_addressof_1 (rtx *loc, rtx insn, int force, int store, int may_postpone,
3019 bool libcall = false;
3021 /* Re-start here to avoid recursion in common cases. */
3028 /* Is this a libcall? */
3030 libcall = REG_NOTE_KIND (*loc) == REG_RETVAL;
3032 code = GET_CODE (x);
3034 /* If we don't return in any of the cases below, we will recurse inside
3035 the RTX, which will normally result in any ADDRESSOF being forced into
3039 result = purge_addressof_1 (&SET_DEST (x), insn, force, 1,
3041 result &= purge_addressof_1 (&SET_SRC (x), insn, force, 0,
3045 else if (code == ADDRESSOF)
3049 if (GET_CODE (XEXP (x, 0)) != MEM)
3050 put_addressof_into_stack (x, ht);
3052 /* We must create a copy of the rtx because it was created by
3053 overwriting a REG rtx which is always shared. */
3054 sub = copy_rtx (XEXP (XEXP (x, 0), 0));
3055 if (validate_change (insn, loc, sub, 0)
3056 || validate_replace_rtx (x, sub, insn))
3061 /* If SUB is a hard or virtual register, try it as a pseudo-register.
3062 Otherwise, perhaps SUB is an expression, so generate code to compute
3064 if (REG_P (sub) && REGNO (sub) <= LAST_VIRTUAL_REGISTER)
3065 sub = copy_to_reg (sub);
3067 sub = force_operand (sub, NULL_RTX);
3069 if (! validate_change (insn, loc, sub, 0)
3070 && ! validate_replace_rtx (x, sub, insn))
3073 insns = get_insns ();
3075 emit_insn_before (insns, insn);
3079 else if (code == MEM && GET_CODE (XEXP (x, 0)) == ADDRESSOF && ! force)
3081 rtx sub = XEXP (XEXP (x, 0), 0);
3083 if (GET_CODE (sub) == MEM)
3084 sub = adjust_address_nv (sub, GET_MODE (x), 0);
3085 else if (REG_P (sub)
3086 && (MEM_VOLATILE_P (x) || GET_MODE (x) == BLKmode))
3088 else if (REG_P (sub) && GET_MODE (x) != GET_MODE (sub))
3090 int size_x, size_sub;
3094 /* Postpone for now, so that we do not emit bitfield arithmetics
3095 unless there is some benefit from it. */
3096 if (!postponed_insns || XEXP (postponed_insns, 0) != insn)
3097 postponed_insns = alloc_INSN_LIST (insn, postponed_insns);
3103 /* When processing REG_NOTES look at the list of
3104 replacements done on the insn to find the register that X
3108 for (tem = purge_bitfield_addressof_replacements;
3110 tem = XEXP (XEXP (tem, 1), 1))
3111 if (rtx_equal_p (x, XEXP (tem, 0)))
3113 *loc = XEXP (XEXP (tem, 1), 0);
3117 /* See comment for purge_addressof_replacements. */
3118 for (tem = purge_addressof_replacements;
3120 tem = XEXP (XEXP (tem, 1), 1))
3121 if (rtx_equal_p (XEXP (x, 0), XEXP (tem, 0)))
3123 rtx z = XEXP (XEXP (tem, 1), 0);
3125 if (GET_MODE (x) == GET_MODE (z)
3126 || (!REG_P (XEXP (XEXP (tem, 1), 0))
3127 && GET_CODE (XEXP (XEXP (tem, 1), 0)) != SUBREG))
3130 /* It can happen that the note may speak of things
3131 in a wider (or just different) mode than the
3132 code did. This is especially true of
3135 if (GET_CODE (z) == SUBREG && SUBREG_BYTE (z) == 0)
3138 if (GET_MODE_SIZE (GET_MODE (x)) > UNITS_PER_WORD
3139 && (GET_MODE_SIZE (GET_MODE (x))
3140 > GET_MODE_SIZE (GET_MODE (z))))
3142 /* This can occur as a result in invalid
3143 pointer casts, e.g. float f; ...
3144 *(long long int *)&f.
3145 ??? We could emit a warning here, but
3146 without a line number that wouldn't be
3148 z = gen_rtx_SUBREG (GET_MODE (x), z, 0);
3151 z = gen_lowpart (GET_MODE (x), z);
3157 /* When we are processing the REG_NOTES of the last instruction
3158 of a libcall, there will be typically no replacements
3159 for that insn; the replacements happened before, piecemeal
3160 fashion. OTOH we are not interested in the details of
3161 this for the REG_EQUAL note, we want to know the big picture,
3162 which can be succinctly described with a simple SUBREG.
3163 Note that removing the REG_EQUAL note is not an option
3164 on the last insn of a libcall, so we must do a replacement. */
3166 /* In compile/990107-1.c:7 compiled at -O1 -m1 for sh-elf,
3168 (mem:DI (addressof:SI (reg/v:DF 160) 159 0x401c8510)
3169 [0 S8 A32]), which can be expressed with a simple
3171 if ((GET_MODE_SIZE (GET_MODE (x))
3172 <= GET_MODE_SIZE (GET_MODE (sub)))
3173 /* Again, invalid pointer casts (as in
3174 compile/990203-1.c) can require paradoxical
3176 || (GET_MODE_SIZE (GET_MODE (x)) > UNITS_PER_WORD
3177 && (GET_MODE_SIZE (GET_MODE (x))
3178 > GET_MODE_SIZE (GET_MODE (sub)))
3181 *loc = gen_rtx_SUBREG (GET_MODE (x), sub, 0);
3184 /* ??? Are there other cases we should handle? */
3186 /* Sometimes we may not be able to find the replacement. For
3187 example when the original insn was a MEM in a wider mode,
3188 and the note is part of a sign extension of a narrowed
3189 version of that MEM. Gcc testcase compile/990829-1.c can
3190 generate an example of this situation. Rather than complain
3191 we return false, which will prompt our caller to remove the
3196 size_x = GET_MODE_BITSIZE (GET_MODE (x));
3197 size_sub = GET_MODE_BITSIZE (GET_MODE (sub));
3199 /* Do not frob unchanging MEMs. If a later reference forces the
3200 pseudo to the stack, we can wind up with multiple writes to
3201 an unchanging memory, which is invalid. */
3202 if (RTX_UNCHANGING_P (x) && size_x != size_sub)
3205 /* Don't even consider working with paradoxical subregs,
3206 or the moral equivalent seen here. */
3207 else if (size_x <= size_sub
3208 && int_mode_for_mode (GET_MODE (sub)) != BLKmode)
3210 /* Do a bitfield insertion to mirror what would happen
3217 rtx p = PREV_INSN (insn);
3220 val = gen_reg_rtx (GET_MODE (x));
3221 if (! validate_change (insn, loc, val, 0))
3223 /* Discard the current sequence and put the
3224 ADDRESSOF on stack. */
3230 emit_insn_before (seq, insn);
3231 compute_insns_for_mem (p ? NEXT_INSN (p) : get_insns (),
3235 store_bit_field (sub, size_x, 0, GET_MODE (x),
3236 val, GET_MODE_SIZE (GET_MODE (sub)));
3238 /* Make sure to unshare any shared rtl that store_bit_field
3239 might have created. */
3240 unshare_all_rtl_again (get_insns ());
3244 p = emit_insn_after (seq, insn);
3245 if (NEXT_INSN (insn))
3246 compute_insns_for_mem (NEXT_INSN (insn),
3247 p ? NEXT_INSN (p) : NULL_RTX,
3252 rtx p = PREV_INSN (insn);
3255 val = extract_bit_field (sub, size_x, 0, 1, NULL_RTX,
3256 GET_MODE (x), GET_MODE (x),
3257 GET_MODE_SIZE (GET_MODE (sub)));
3259 if (! validate_change (insn, loc, val, 0))
3261 /* Discard the current sequence and put the
3262 ADDRESSOF on stack. */
3269 emit_insn_before (seq, insn);
3270 compute_insns_for_mem (p ? NEXT_INSN (p) : get_insns (),
3274 /* Remember the replacement so that the same one can be done
3275 on the REG_NOTES. */
3276 purge_bitfield_addressof_replacements
3277 = gen_rtx_EXPR_LIST (VOIDmode, x,
3280 purge_bitfield_addressof_replacements));
3282 /* We replaced with a reg -- all done. */
3287 else if (validate_change (insn, loc, sub, 0))
3289 /* Remember the replacement so that the same one can be done
3290 on the REG_NOTES. */
3291 if (REG_P (sub) || GET_CODE (sub) == SUBREG)
3295 for (tem = purge_addressof_replacements;
3297 tem = XEXP (XEXP (tem, 1), 1))
3298 if (rtx_equal_p (XEXP (x, 0), XEXP (tem, 0)))
3300 XEXP (XEXP (tem, 1), 0) = sub;
3303 purge_addressof_replacements
3304 = gen_rtx_EXPR_LIST (VOIDmode, XEXP (x, 0),
3305 gen_rtx_EXPR_LIST (VOIDmode, sub,
3306 purge_addressof_replacements));
3314 /* Scan all subexpressions. */
3315 fmt = GET_RTX_FORMAT (code);
3316 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
3319 result &= purge_addressof_1 (&XEXP (x, i), insn, force, 0,
3321 else if (*fmt == 'E')
3322 for (j = 0; j < XVECLEN (x, i); j++)
3323 result &= purge_addressof_1 (&XVECEXP (x, i, j), insn, force, 0,
3330 /* Return a hash value for K, a REG. */
3333 insns_for_mem_hash (const void *k)
3335 /* Use the address of the key for the hash value. */
3336 struct insns_for_mem_entry *m = (struct insns_for_mem_entry *) k;
3337 return htab_hash_pointer (m->key);
3340 /* Return nonzero if K1 and K2 (two REGs) are the same. */
3343 insns_for_mem_comp (const void *k1, const void *k2)
3345 struct insns_for_mem_entry *m1 = (struct insns_for_mem_entry *) k1;
3346 struct insns_for_mem_entry *m2 = (struct insns_for_mem_entry *) k2;
3347 return m1->key == m2->key;
3350 struct insns_for_mem_walk_info
3352 /* The hash table that we are using to record which INSNs use which
3356 /* The INSN we are currently processing. */
3359 /* Zero if we are walking to find ADDRESSOFs, one if we are walking
3360 to find the insns that use the REGs in the ADDRESSOFs. */
3364 /* Called from compute_insns_for_mem via for_each_rtx. If R is a REG
3365 that might be used in an ADDRESSOF expression, record this INSN in
3366 the hash table given by DATA (which is really a pointer to an
3367 insns_for_mem_walk_info structure). */
3370 insns_for_mem_walk (rtx *r, void *data)
3372 struct insns_for_mem_walk_info *ifmwi
3373 = (struct insns_for_mem_walk_info *) data;
3374 struct insns_for_mem_entry tmp;
3375 tmp.insns = NULL_RTX;
3377 if (ifmwi->pass == 0 && *r && GET_CODE (*r) == ADDRESSOF
3378 && REG_P (XEXP (*r, 0)))
3381 tmp.key = XEXP (*r, 0);
3382 e = htab_find_slot (ifmwi->ht, &tmp, INSERT);
3385 *e = ggc_alloc (sizeof (tmp));
3386 memcpy (*e, &tmp, sizeof (tmp));
3389 else if (ifmwi->pass == 1 && *r && REG_P (*r))
3391 struct insns_for_mem_entry *ifme;
3393 ifme = htab_find (ifmwi->ht, &tmp);
3395 /* If we have not already recorded this INSN, do so now. Since
3396 we process the INSNs in order, we know that if we have
3397 recorded it it must be at the front of the list. */
3398 if (ifme && (!ifme->insns || XEXP (ifme->insns, 0) != ifmwi->insn))
3399 ifme->insns = gen_rtx_EXPR_LIST (VOIDmode, ifmwi->insn,
3406 /* Walk the INSNS, until we reach LAST_INSN, recording which INSNs use
3407 which REGs in HT. */
3410 compute_insns_for_mem (rtx insns, rtx last_insn, htab_t ht)
3413 struct insns_for_mem_walk_info ifmwi;
3416 for (ifmwi.pass = 0; ifmwi.pass < 2; ++ifmwi.pass)
3417 for (insn = insns; insn != last_insn; insn = NEXT_INSN (insn))
3421 for_each_rtx (&insn, insns_for_mem_walk, &ifmwi);
3425 /* Helper function for purge_addressof called through for_each_rtx.
3426 Returns true iff the rtl is an ADDRESSOF. */
3429 is_addressof (rtx *rtl, void *data ATTRIBUTE_UNUSED)
3431 return GET_CODE (*rtl) == ADDRESSOF;
3434 /* Eliminate all occurrences of ADDRESSOF from INSNS. Elide any remaining
3435 (MEM (ADDRESSOF)) patterns, and force any needed registers into the
3439 purge_addressof (rtx insns)
3444 /* When we actually purge ADDRESSOFs, we turn REGs into MEMs. That
3445 requires a fixup pass over the instruction stream to correct
3446 INSNs that depended on the REG being a REG, and not a MEM. But,
3447 these fixup passes are slow. Furthermore, most MEMs are not
3448 mentioned in very many instructions. So, we speed up the process
3449 by pre-calculating which REGs occur in which INSNs; that allows
3450 us to perform the fixup passes much more quickly. */
3451 ht = htab_create_ggc (1000, insns_for_mem_hash, insns_for_mem_comp, NULL);
3452 compute_insns_for_mem (insns, NULL_RTX, ht);
3454 postponed_insns = NULL;
3456 for (insn = insns; insn; insn = NEXT_INSN (insn))
3459 if (! purge_addressof_1 (&PATTERN (insn), insn,
3460 asm_noperands (PATTERN (insn)) > 0, 0, 1, ht))
3461 /* If we could not replace the ADDRESSOFs in the insn,
3462 something is wrong. */
3465 if (! purge_addressof_1 (®_NOTES (insn), NULL_RTX, 0, 0, 0, ht))
3467 /* If we could not replace the ADDRESSOFs in the insn's notes,
3468 we can just remove the offending notes instead. */
3471 for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
3473 /* If we find a REG_RETVAL note then the insn is a libcall.
3474 Such insns must have REG_EQUAL notes as well, in order
3475 for later passes of the compiler to work. So it is not
3476 safe to delete the notes here, and instead we abort. */
3477 if (REG_NOTE_KIND (note) == REG_RETVAL)
3479 if (for_each_rtx (¬e, is_addressof, NULL))
3480 remove_note (insn, note);
3485 /* Process the postponed insns. */
3486 while (postponed_insns)
3488 insn = XEXP (postponed_insns, 0);
3489 tmp = postponed_insns;
3490 postponed_insns = XEXP (postponed_insns, 1);
3491 free_INSN_LIST_node (tmp);
3493 if (! purge_addressof_1 (&PATTERN (insn), insn,
3494 asm_noperands (PATTERN (insn)) > 0, 0, 0, ht))
3499 purge_bitfield_addressof_replacements = 0;
3500 purge_addressof_replacements = 0;
3502 /* REGs are shared. purge_addressof will destructively replace a REG
3503 with a MEM, which creates shared MEMs.
3505 Unfortunately, the children of put_reg_into_stack assume that MEMs
3506 referring to the same stack slot are shared (fixup_var_refs and
3507 the associated hash table code).
3509 So, we have to do another unsharing pass after we have flushed any
3510 REGs that had their address taken into the stack.
3512 It may be worth tracking whether or not we converted any REGs into
3513 MEMs to avoid this overhead when it is not needed. */
3514 unshare_all_rtl_again (get_insns ());
3517 /* Convert a SET of a hard subreg to a set of the appropriate hard
3518 register. A subroutine of purge_hard_subreg_sets. */
3521 purge_single_hard_subreg_set (rtx pattern)
3523 rtx reg = SET_DEST (pattern);
3524 enum machine_mode mode = GET_MODE (SET_DEST (pattern));
3527 if (GET_CODE (reg) == SUBREG && REG_P (SUBREG_REG (reg))
3528 && REGNO (SUBREG_REG (reg)) < FIRST_PSEUDO_REGISTER)
3530 offset = subreg_regno_offset (REGNO (SUBREG_REG (reg)),
3531 GET_MODE (SUBREG_REG (reg)),
3534 reg = SUBREG_REG (reg);
3538 if (REG_P (reg) && REGNO (reg) < FIRST_PSEUDO_REGISTER)
3540 reg = gen_rtx_REG (mode, REGNO (reg) + offset);
3541 SET_DEST (pattern) = reg;
3545 /* Eliminate all occurrences of SETs of hard subregs from INSNS. The
3546 only such SETs that we expect to see are those left in because
3547 integrate can't handle sets of parts of a return value register.
3549 We don't use alter_subreg because we only want to eliminate subregs
3550 of hard registers. */
3553 purge_hard_subreg_sets (rtx insn)
3555 for (; insn; insn = NEXT_INSN (insn))
3559 rtx pattern = PATTERN (insn);
3560 switch (GET_CODE (pattern))
3563 if (GET_CODE (SET_DEST (pattern)) == SUBREG)
3564 purge_single_hard_subreg_set (pattern);
3569 for (j = XVECLEN (pattern, 0) - 1; j >= 0; j--)
3571 rtx inner_pattern = XVECEXP (pattern, 0, j);
3572 if (GET_CODE (inner_pattern) == SET
3573 && GET_CODE (SET_DEST (inner_pattern)) == SUBREG)
3574 purge_single_hard_subreg_set (inner_pattern);
3585 /* Pass through the INSNS of function FNDECL and convert virtual register
3586 references to hard register references. */
3589 instantiate_virtual_regs (void)
3594 /* Compute the offsets to use for this function. */
3595 in_arg_offset = FIRST_PARM_OFFSET (current_function_decl);
3596 var_offset = STARTING_FRAME_OFFSET;
3597 dynamic_offset = STACK_DYNAMIC_OFFSET (current_function_decl);
3598 out_arg_offset = STACK_POINTER_OFFSET;
3599 cfa_offset = ARG_POINTER_CFA_OFFSET (current_function_decl);
3601 /* Scan all variables and parameters of this function. For each that is
3602 in memory, instantiate all virtual registers if the result is a valid
3603 address. If not, we do it later. That will handle most uses of virtual
3604 regs on many machines. */
3605 instantiate_decls (current_function_decl, 1);
3607 /* Initialize recognition, indicating that volatile is OK. */
3610 /* Scan through all the insns, instantiating every virtual register still
3612 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3613 if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN
3614 || GET_CODE (insn) == CALL_INSN)
3616 instantiate_virtual_regs_1 (&PATTERN (insn), insn, 1);
3617 if (INSN_DELETED_P (insn))
3619 instantiate_virtual_regs_1 (®_NOTES (insn), NULL_RTX, 0);
3620 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
3621 if (GET_CODE (insn) == CALL_INSN)
3622 instantiate_virtual_regs_1 (&CALL_INSN_FUNCTION_USAGE (insn),
3625 /* Past this point all ASM statements should match. Verify that
3626 to avoid failures later in the compilation process. */
3627 if (asm_noperands (PATTERN (insn)) >= 0
3628 && ! check_asm_operands (PATTERN (insn)))
3629 instantiate_virtual_regs_lossage (insn);
3632 /* Instantiate the stack slots for the parm registers, for later use in
3633 addressof elimination. */
3634 for (i = 0; i < max_parm_reg; ++i)
3635 if (parm_reg_stack_loc[i])
3636 instantiate_virtual_regs_1 (&parm_reg_stack_loc[i], NULL_RTX, 0);
3638 /* Now instantiate the remaining register equivalences for debugging info.
3639 These will not be valid addresses. */
3640 instantiate_decls (current_function_decl, 0);
3642 /* Indicate that, from now on, assign_stack_local should use
3643 frame_pointer_rtx. */
3644 virtuals_instantiated = 1;
3647 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
3648 all virtual registers in their DECL_RTL's.
3650 If VALID_ONLY, do this only if the resulting address is still valid.
3651 Otherwise, always do it. */
3654 instantiate_decls (tree fndecl, int valid_only)
3658 /* Process all parameters of the function. */
3659 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = TREE_CHAIN (decl))
3661 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (decl));
3662 HOST_WIDE_INT size_rtl;
3664 instantiate_decl (DECL_RTL (decl), size, valid_only);
3666 /* If the parameter was promoted, then the incoming RTL mode may be
3667 larger than the declared type size. We must use the larger of
3669 size_rtl = GET_MODE_SIZE (GET_MODE (DECL_INCOMING_RTL (decl)));
3670 size = MAX (size_rtl, size);
3671 instantiate_decl (DECL_INCOMING_RTL (decl), size, valid_only);
3674 /* Now process all variables defined in the function or its subblocks. */
3675 instantiate_decls_1 (DECL_INITIAL (fndecl), valid_only);
3678 /* Subroutine of instantiate_decls: Process all decls in the given
3679 BLOCK node and all its subblocks. */
3682 instantiate_decls_1 (tree let, int valid_only)
3686 for (t = BLOCK_VARS (let); t; t = TREE_CHAIN (t))
3687 if (DECL_RTL_SET_P (t))
3688 instantiate_decl (DECL_RTL (t),
3689 int_size_in_bytes (TREE_TYPE (t)),
3692 /* Process all subblocks. */
3693 for (t = BLOCK_SUBBLOCKS (let); t; t = TREE_CHAIN (t))
3694 instantiate_decls_1 (t, valid_only);
3697 /* Subroutine of the preceding procedures: Given RTL representing a
3698 decl and the size of the object, do any instantiation required.
3700 If VALID_ONLY is nonzero, it means that the RTL should only be
3701 changed if the new address is valid. */
3704 instantiate_decl (rtx x, HOST_WIDE_INT size, int valid_only)
3706 enum machine_mode mode;
3709 /* If this is not a MEM, no need to do anything. Similarly if the
3710 address is a constant or a register that is not a virtual register. */
3712 if (x == 0 || GET_CODE (x) != MEM)
3716 if (CONSTANT_P (addr)
3717 || (GET_CODE (addr) == ADDRESSOF && REG_P (XEXP (addr, 0)))
3719 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
3720 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
3723 /* If we should only do this if the address is valid, copy the address.
3724 We need to do this so we can undo any changes that might make the
3725 address invalid. This copy is unfortunate, but probably can't be
3729 addr = copy_rtx (addr);
3731 instantiate_virtual_regs_1 (&addr, NULL_RTX, 0);
3733 if (valid_only && size >= 0)
3735 unsigned HOST_WIDE_INT decl_size = size;
3737 /* Now verify that the resulting address is valid for every integer or
3738 floating-point mode up to and including SIZE bytes long. We do this
3739 since the object might be accessed in any mode and frame addresses
3742 for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
3743 mode != VOIDmode && GET_MODE_SIZE (mode) <= decl_size;
3744 mode = GET_MODE_WIDER_MODE (mode))
3745 if (! memory_address_p (mode, addr))
3748 for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT);
3749 mode != VOIDmode && GET_MODE_SIZE (mode) <= decl_size;
3750 mode = GET_MODE_WIDER_MODE (mode))
3751 if (! memory_address_p (mode, addr))
3755 /* Put back the address now that we have updated it and we either know
3756 it is valid or we don't care whether it is valid. */
3761 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
3762 is a virtual register, return the equivalent hard register and set the
3763 offset indirectly through the pointer. Otherwise, return 0. */
3766 instantiate_new_reg (rtx x, HOST_WIDE_INT *poffset)
3769 HOST_WIDE_INT offset;
3771 if (x == virtual_incoming_args_rtx)
3772 new = arg_pointer_rtx, offset = in_arg_offset;
3773 else if (x == virtual_stack_vars_rtx)
3774 new = frame_pointer_rtx, offset = var_offset;
3775 else if (x == virtual_stack_dynamic_rtx)
3776 new = stack_pointer_rtx, offset = dynamic_offset;
3777 else if (x == virtual_outgoing_args_rtx)
3778 new = stack_pointer_rtx, offset = out_arg_offset;
3779 else if (x == virtual_cfa_rtx)
3780 new = arg_pointer_rtx, offset = cfa_offset;
3789 /* Called when instantiate_virtual_regs has failed to update the instruction.
3790 Usually this means that non-matching instruction has been emit, however for
3791 asm statements it may be the problem in the constraints. */
3793 instantiate_virtual_regs_lossage (rtx insn)
3795 if (asm_noperands (PATTERN (insn)) >= 0)
3797 error_for_asm (insn, "impossible constraint in `asm'");
3803 /* Given a pointer to a piece of rtx and an optional pointer to the
3804 containing object, instantiate any virtual registers present in it.
3806 If EXTRA_INSNS, we always do the replacement and generate
3807 any extra insns before OBJECT. If it zero, we do nothing if replacement
3810 Return 1 if we either had nothing to do or if we were able to do the
3811 needed replacement. Return 0 otherwise; we only return zero if
3812 EXTRA_INSNS is zero.
3814 We first try some simple transformations to avoid the creation of extra
3818 instantiate_virtual_regs_1 (rtx *loc, rtx object, int extra_insns)
3823 HOST_WIDE_INT offset = 0;
3829 /* Re-start here to avoid recursion in common cases. */
3836 /* We may have detected and deleted invalid asm statements. */
3837 if (object && INSN_P (object) && INSN_DELETED_P (object))
3840 code = GET_CODE (x);
3842 /* Check for some special cases. */
3860 /* We are allowed to set the virtual registers. This means that
3861 the actual register should receive the source minus the
3862 appropriate offset. This is used, for example, in the handling
3863 of non-local gotos. */
3864 if ((new = instantiate_new_reg (SET_DEST (x), &offset)) != 0)
3866 rtx src = SET_SRC (x);
3868 /* We are setting the register, not using it, so the relevant
3869 offset is the negative of the offset to use were we using
3872 instantiate_virtual_regs_1 (&src, NULL_RTX, 0);
3874 /* The only valid sources here are PLUS or REG. Just do
3875 the simplest possible thing to handle them. */
3876 if (!REG_P (src) && GET_CODE (src) != PLUS)
3878 instantiate_virtual_regs_lossage (object);
3884 temp = force_operand (src, NULL_RTX);
3887 temp = force_operand (plus_constant (temp, offset), NULL_RTX);
3891 emit_insn_before (seq, object);
3894 if (! validate_change (object, &SET_SRC (x), temp, 0)
3896 instantiate_virtual_regs_lossage (object);
3901 instantiate_virtual_regs_1 (&SET_DEST (x), object, extra_insns);
3906 /* Handle special case of virtual register plus constant. */
3907 if (CONSTANT_P (XEXP (x, 1)))
3909 rtx old, new_offset;
3911 /* Check for (plus (plus VIRT foo) (const_int)) first. */
3912 if (GET_CODE (XEXP (x, 0)) == PLUS)
3914 if ((new = instantiate_new_reg (XEXP (XEXP (x, 0), 0), &offset)))
3916 instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 1), object,
3918 new = gen_rtx_PLUS (Pmode, new, XEXP (XEXP (x, 0), 1));
3927 #ifdef POINTERS_EXTEND_UNSIGNED
3928 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
3929 we can commute the PLUS and SUBREG because pointers into the
3930 frame are well-behaved. */
3931 else if (GET_CODE (XEXP (x, 0)) == SUBREG && GET_MODE (x) == ptr_mode
3932 && GET_CODE (XEXP (x, 1)) == CONST_INT
3934 = instantiate_new_reg (SUBREG_REG (XEXP (x, 0)),
3936 && validate_change (object, loc,
3937 plus_constant (gen_lowpart (ptr_mode,
3940 + INTVAL (XEXP (x, 1))),
3944 else if ((new = instantiate_new_reg (XEXP (x, 0), &offset)) == 0)
3946 /* We know the second operand is a constant. Unless the
3947 first operand is a REG (which has been already checked),
3948 it needs to be checked. */
3949 if (!REG_P (XEXP (x, 0)))
3957 new_offset = plus_constant (XEXP (x, 1), offset);
3959 /* If the new constant is zero, try to replace the sum with just
3961 if (new_offset == const0_rtx
3962 && validate_change (object, loc, new, 0))
3965 /* Next try to replace the register and new offset.
3966 There are two changes to validate here and we can't assume that
3967 in the case of old offset equals new just changing the register
3968 will yield a valid insn. In the interests of a little efficiency,
3969 however, we only call validate change once (we don't queue up the
3970 changes and then call apply_change_group). */
3974 ? ! validate_change (object, &XEXP (x, 0), new, 0)
3975 : (XEXP (x, 0) = new,
3976 ! validate_change (object, &XEXP (x, 1), new_offset, 0)))
3984 /* Otherwise copy the new constant into a register and replace
3985 constant with that register. */
3986 temp = gen_reg_rtx (Pmode);
3988 if (validate_change (object, &XEXP (x, 1), temp, 0))
3989 emit_insn_before (gen_move_insn (temp, new_offset), object);
3992 /* If that didn't work, replace this expression with a
3993 register containing the sum. */
3996 new = gen_rtx_PLUS (Pmode, new, new_offset);
3999 temp = force_operand (new, NULL_RTX);
4003 emit_insn_before (seq, object);
4004 if (! validate_change (object, loc, temp, 0)
4005 && ! validate_replace_rtx (x, temp, object))
4007 instantiate_virtual_regs_lossage (object);
4016 /* Fall through to generic two-operand expression case. */
4022 case DIV: case UDIV:
4023 case MOD: case UMOD:
4024 case AND: case IOR: case XOR:
4025 case ROTATERT: case ROTATE:
4026 case ASHIFTRT: case LSHIFTRT: case ASHIFT:
4028 case GE: case GT: case GEU: case GTU:
4029 case LE: case LT: case LEU: case LTU:
4030 if (XEXP (x, 1) && ! CONSTANT_P (XEXP (x, 1)))
4031 instantiate_virtual_regs_1 (&XEXP (x, 1), object, extra_insns);
4036 /* Most cases of MEM that convert to valid addresses have already been
4037 handled by our scan of decls. The only special handling we
4038 need here is to make a copy of the rtx to ensure it isn't being
4039 shared if we have to change it to a pseudo.
4041 If the rtx is a simple reference to an address via a virtual register,
4042 it can potentially be shared. In such cases, first try to make it
4043 a valid address, which can also be shared. Otherwise, copy it and
4046 First check for common cases that need no processing. These are
4047 usually due to instantiation already being done on a previous instance
4051 if (CONSTANT_ADDRESS_P (temp)
4052 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
4053 || temp == arg_pointer_rtx
4055 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
4056 || temp == hard_frame_pointer_rtx
4058 || temp == frame_pointer_rtx)
4061 if (GET_CODE (temp) == PLUS
4062 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
4063 && (XEXP (temp, 0) == frame_pointer_rtx
4064 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
4065 || XEXP (temp, 0) == hard_frame_pointer_rtx
4067 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
4068 || XEXP (temp, 0) == arg_pointer_rtx
4073 if (temp == virtual_stack_vars_rtx
4074 || temp == virtual_incoming_args_rtx
4075 || (GET_CODE (temp) == PLUS
4076 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
4077 && (XEXP (temp, 0) == virtual_stack_vars_rtx
4078 || XEXP (temp, 0) == virtual_incoming_args_rtx)))
4080 /* This MEM may be shared. If the substitution can be done without
4081 the need to generate new pseudos, we want to do it in place
4082 so all copies of the shared rtx benefit. The call below will
4083 only make substitutions if the resulting address is still
4086 Note that we cannot pass X as the object in the recursive call
4087 since the insn being processed may not allow all valid
4088 addresses. However, if we were not passed on object, we can
4089 only modify X without copying it if X will have a valid
4092 ??? Also note that this can still lose if OBJECT is an insn that
4093 has less restrictions on an address that some other insn.
4094 In that case, we will modify the shared address. This case
4095 doesn't seem very likely, though. One case where this could
4096 happen is in the case of a USE or CLOBBER reference, but we
4097 take care of that below. */
4099 if (instantiate_virtual_regs_1 (&XEXP (x, 0),
4100 object ? object : x, 0))
4103 /* Otherwise make a copy and process that copy. We copy the entire
4104 RTL expression since it might be a PLUS which could also be
4106 *loc = x = copy_rtx (x);
4109 /* Fall through to generic unary operation case. */
4112 case STRICT_LOW_PART:
4114 case PRE_DEC: case PRE_INC: case POST_DEC: case POST_INC:
4115 case SIGN_EXTEND: case ZERO_EXTEND:
4116 case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE:
4117 case FLOAT: case FIX:
4118 case UNSIGNED_FIX: case UNSIGNED_FLOAT:
4123 case POPCOUNT: case PARITY:
4124 /* These case either have just one operand or we know that we need not
4125 check the rest of the operands. */
4131 /* If the operand is a MEM, see if the change is a valid MEM. If not,
4132 go ahead and make the invalid one, but do it to a copy. For a REG,
4133 just make the recursive call, since there's no chance of a problem. */
4135 if ((GET_CODE (XEXP (x, 0)) == MEM
4136 && instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 0), XEXP (x, 0),
4138 || (REG_P (XEXP (x, 0))
4139 && instantiate_virtual_regs_1 (&XEXP (x, 0), object, 0)))
4142 XEXP (x, 0) = copy_rtx (XEXP (x, 0));
4147 /* Try to replace with a PLUS. If that doesn't work, compute the sum
4148 in front of this insn and substitute the temporary. */
4149 if ((new = instantiate_new_reg (x, &offset)) != 0)
4151 temp = plus_constant (new, offset);
4152 if (!validate_change (object, loc, temp, 0))
4158 temp = force_operand (temp, NULL_RTX);
4162 emit_insn_before (seq, object);
4163 if (! validate_change (object, loc, temp, 0)
4164 && ! validate_replace_rtx (x, temp, object))
4165 instantiate_virtual_regs_lossage (object);
4172 if (REG_P (XEXP (x, 0)))
4175 else if (GET_CODE (XEXP (x, 0)) == MEM)
4177 /* If we have a (addressof (mem ..)), do any instantiation inside
4178 since we know we'll be making the inside valid when we finally
4179 remove the ADDRESSOF. */
4180 instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 0), NULL_RTX, 0);
4189 /* Scan all subexpressions. */
4190 fmt = GET_RTX_FORMAT (code);
4191 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
4194 if (!instantiate_virtual_regs_1 (&XEXP (x, i), object, extra_insns))
4197 else if (*fmt == 'E')
4198 for (j = 0; j < XVECLEN (x, i); j++)
4199 if (! instantiate_virtual_regs_1 (&XVECEXP (x, i, j), object,
4206 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
4207 This means a type for which function calls must pass an address to the
4208 function or get an address back from the function.
4209 EXP may be a type node or an expression (whose type is tested). */
4212 aggregate_value_p (tree exp, tree fntype)
4214 int i, regno, nregs;
4217 tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
4220 switch (TREE_CODE (fntype))
4223 fntype = get_callee_fndecl (fntype);
4224 fntype = fntype ? TREE_TYPE (fntype) : 0;
4227 fntype = TREE_TYPE (fntype);
4232 case IDENTIFIER_NODE:
4236 /* We don't expect other rtl types here. */
4240 if (TREE_CODE (type) == VOID_TYPE)
4242 if (targetm.calls.return_in_memory (type, fntype))
4244 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
4245 and thus can't be returned in registers. */
4246 if (TREE_ADDRESSABLE (type))
4248 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
4250 /* Make sure we have suitable call-clobbered regs to return
4251 the value in; if not, we must return it in memory. */
4252 reg = hard_function_value (type, 0, 0);
4254 /* If we have something other than a REG (e.g. a PARALLEL), then assume
4259 regno = REGNO (reg);
4260 nregs = hard_regno_nregs[regno][TYPE_MODE (type)];
4261 for (i = 0; i < nregs; i++)
4262 if (! call_used_regs[regno + i])
4267 /* Assign RTL expressions to the function's parameters.
4268 This may involve copying them into registers and using
4269 those registers as the RTL for them. */
4272 assign_parms (tree fndecl)
4275 CUMULATIVE_ARGS args_so_far;
4276 /* Total space needed so far for args on the stack,
4277 given as a constant and a tree-expression. */
4278 struct args_size stack_args_size;
4279 HOST_WIDE_INT extra_pretend_bytes = 0;
4280 tree fntype = TREE_TYPE (fndecl);
4281 tree fnargs = DECL_ARGUMENTS (fndecl), orig_fnargs;
4282 /* This is used for the arg pointer when referring to stack args. */
4283 rtx internal_arg_pointer;
4284 /* This is a dummy PARM_DECL that we used for the function result if
4285 the function returns a structure. */
4286 tree function_result_decl = 0;
4287 int varargs_setup = 0;
4288 int reg_parm_stack_space ATTRIBUTE_UNUSED = 0;
4289 rtx conversion_insns = 0;
4291 /* Nonzero if function takes extra anonymous args.
4292 This means the last named arg must be on the stack
4293 right before the anonymous ones. */
4294 int stdarg = current_function_stdarg;
4296 /* If the reg that the virtual arg pointer will be translated into is
4297 not a fixed reg or is the stack pointer, make a copy of the virtual
4298 arg pointer, and address parms via the copy. The frame pointer is
4299 considered fixed even though it is not marked as such.
4301 The second time through, simply use ap to avoid generating rtx. */
4303 if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
4304 || ! (fixed_regs[ARG_POINTER_REGNUM]
4305 || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
4306 internal_arg_pointer = copy_to_reg (virtual_incoming_args_rtx);
4308 internal_arg_pointer = virtual_incoming_args_rtx;
4309 current_function_internal_arg_pointer = internal_arg_pointer;
4311 stack_args_size.constant = 0;
4312 stack_args_size.var = 0;
4314 /* If struct value address is treated as the first argument, make it so. */
4315 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
4316 && ! current_function_returns_pcc_struct
4317 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
4319 tree type = build_pointer_type (TREE_TYPE (fntype));
4321 function_result_decl = build_decl (PARM_DECL, NULL_TREE, type);
4323 DECL_ARG_TYPE (function_result_decl) = type;
4324 TREE_CHAIN (function_result_decl) = fnargs;
4325 fnargs = function_result_decl;
4328 orig_fnargs = fnargs;
4330 max_parm_reg = LAST_VIRTUAL_REGISTER + 1;
4331 parm_reg_stack_loc = ggc_alloc_cleared (max_parm_reg * sizeof (rtx));
4333 /* If the target wants to split complex arguments into scalars, do so. */
4334 if (targetm.calls.split_complex_arg)
4335 fnargs = split_complex_args (fnargs);
4337 #ifdef REG_PARM_STACK_SPACE
4338 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
4341 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
4342 INIT_CUMULATIVE_INCOMING_ARGS (args_so_far, fntype, NULL_RTX);
4344 INIT_CUMULATIVE_ARGS (args_so_far, fntype, NULL_RTX, fndecl, -1);
4347 /* We haven't yet found an argument that we must push and pretend the
4349 current_function_pretend_args_size = 0;
4351 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
4355 enum machine_mode promoted_mode, passed_mode;
4356 enum machine_mode nominal_mode, promoted_nominal_mode;
4358 struct locate_and_pad_arg_data locate;
4359 int passed_pointer = 0;
4360 int did_conversion = 0;
4361 tree passed_type = DECL_ARG_TYPE (parm);
4362 tree nominal_type = TREE_TYPE (parm);
4363 int last_named = 0, named_arg;
4366 int pretend_bytes = 0;
4367 int loaded_in_reg = 0;
4369 /* Set LAST_NAMED if this is last named arg before last
4375 for (tem = TREE_CHAIN (parm); tem; tem = TREE_CHAIN (tem))
4376 if (DECL_NAME (tem))
4382 /* Set NAMED_ARG if this arg should be treated as a named arg. For
4383 most machines, if this is a varargs/stdarg function, then we treat
4384 the last named arg as if it were anonymous too. */
4385 named_arg = (targetm.calls.strict_argument_naming (&args_so_far)
4388 if (TREE_TYPE (parm) == error_mark_node
4389 /* This can happen after weird syntax errors
4390 or if an enum type is defined among the parms. */
4391 || TREE_CODE (parm) != PARM_DECL
4392 || passed_type == NULL)
4394 SET_DECL_RTL (parm, gen_rtx_MEM (BLKmode, const0_rtx));
4395 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
4396 TREE_USED (parm) = 1;
4400 /* Find mode of arg as it is passed, and mode of arg
4401 as it should be during execution of this function. */
4402 passed_mode = TYPE_MODE (passed_type);
4403 nominal_mode = TYPE_MODE (nominal_type);
4405 /* If the parm's mode is VOID, its value doesn't matter,
4406 and avoid the usual things like emit_move_insn that could crash. */
4407 if (nominal_mode == VOIDmode)
4409 SET_DECL_RTL (parm, const0_rtx);
4410 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
4414 /* If the parm is to be passed as a transparent union, use the
4415 type of the first field for the tests below. We have already
4416 verified that the modes are the same. */
4417 if (DECL_TRANSPARENT_UNION (parm)
4418 || (TREE_CODE (passed_type) == UNION_TYPE
4419 && TYPE_TRANSPARENT_UNION (passed_type)))
4420 passed_type = TREE_TYPE (TYPE_FIELDS (passed_type));
4422 /* See if this arg was passed by invisible reference. It is if
4423 it is an object whose size depends on the contents of the
4424 object itself or if the machine requires these objects be passed
4427 if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (passed_type))
4428 || TREE_ADDRESSABLE (passed_type)
4429 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
4430 || FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, passed_mode,
4431 passed_type, named_arg)
4435 passed_type = nominal_type = build_pointer_type (passed_type);
4437 passed_mode = nominal_mode = Pmode;
4439 /* See if the frontend wants to pass this by invisible reference. */
4440 else if (passed_type != nominal_type
4441 && POINTER_TYPE_P (passed_type)
4442 && TREE_TYPE (passed_type) == nominal_type)
4444 nominal_type = passed_type;
4446 passed_mode = nominal_mode = Pmode;
4449 promoted_mode = passed_mode;
4451 if (targetm.calls.promote_function_args (TREE_TYPE (fndecl)))
4453 /* Compute the mode in which the arg is actually extended to. */
4454 unsignedp = TYPE_UNSIGNED (passed_type);
4455 promoted_mode = promote_mode (passed_type, promoted_mode,
4459 /* Let machine desc say which reg (if any) the parm arrives in.
4460 0 means it arrives on the stack. */
4461 #ifdef FUNCTION_INCOMING_ARG
4462 entry_parm = FUNCTION_INCOMING_ARG (args_so_far, promoted_mode,
4463 passed_type, named_arg);
4465 entry_parm = FUNCTION_ARG (args_so_far, promoted_mode,
4466 passed_type, named_arg);
4469 if (entry_parm == 0)
4470 promoted_mode = passed_mode;
4472 /* If this is the last named parameter, do any required setup for
4473 varargs or stdargs. We need to know about the case of this being an
4474 addressable type, in which case we skip the registers it
4475 would have arrived in.
4477 For stdargs, LAST_NAMED will be set for two parameters, the one that
4478 is actually the last named, and the dummy parameter. We only
4479 want to do this action once.
4481 Also, indicate when RTL generation is to be suppressed. */
4482 if (last_named && !varargs_setup)
4484 int varargs_pretend_bytes = 0;
4485 targetm.calls.setup_incoming_varargs (&args_so_far, promoted_mode,
4487 &varargs_pretend_bytes, 0);
4490 /* If the back-end has requested extra stack space, record how
4491 much is needed. Do not change pretend_args_size otherwise
4492 since it may be nonzero from an earlier partial argument. */
4493 if (varargs_pretend_bytes > 0)
4494 current_function_pretend_args_size = varargs_pretend_bytes;
4497 /* Determine parm's home in the stack,
4498 in case it arrives in the stack or we should pretend it did.
4500 Compute the stack position and rtx where the argument arrives
4503 There is one complexity here: If this was a parameter that would
4504 have been passed in registers, but wasn't only because it is
4505 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
4506 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
4507 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of
4508 0 as it was the previous time. */
4509 in_regs = entry_parm != 0;
4510 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4513 if (!in_regs && !named_arg)
4516 targetm.calls.pretend_outgoing_varargs_named (&args_so_far);
4519 #ifdef FUNCTION_INCOMING_ARG
4520 in_regs = FUNCTION_INCOMING_ARG (args_so_far, promoted_mode,
4522 pretend_named) != 0;
4524 in_regs = FUNCTION_ARG (args_so_far, promoted_mode,
4526 pretend_named) != 0;
4531 /* If this parameter was passed both in registers and in the stack,
4532 use the copy on the stack. */
4533 if (MUST_PASS_IN_STACK (promoted_mode, passed_type))
4536 #ifdef FUNCTION_ARG_PARTIAL_NREGS
4539 partial = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, promoted_mode,
4540 passed_type, named_arg);
4542 /* The caller might already have allocated stack space
4543 for the register parameters. */
4544 && reg_parm_stack_space == 0)
4546 /* Part of this argument is passed in registers and part
4547 is passed on the stack. Ask the prologue code to extend
4548 the stack part so that we can recreate the full value.
4550 PRETEND_BYTES is the size of the registers we need to store.
4551 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
4552 stack space that the prologue should allocate.
4554 Internally, gcc assumes that the argument pointer is
4555 aligned to STACK_BOUNDARY bits. This is used both for
4556 alignment optimizations (see init_emit) and to locate
4557 arguments that are aligned to more than PARM_BOUNDARY
4558 bits. We must preserve this invariant by rounding
4559 CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to a stack
4562 /* We assume at most one partial arg, and it must be the first
4563 argument on the stack. */
4564 if (extra_pretend_bytes || current_function_pretend_args_size)
4567 pretend_bytes = partial * UNITS_PER_WORD;
4568 current_function_pretend_args_size
4569 = CEIL_ROUND (pretend_bytes, STACK_BYTES);
4571 /* We want to align relative to the actual stack pointer, so
4572 don't include this in the stack size until later. */
4573 extra_pretend_bytes = current_function_pretend_args_size;
4578 memset (&locate, 0, sizeof (locate));
4579 locate_and_pad_parm (promoted_mode, passed_type, in_regs,
4580 entry_parm ? partial : 0, fndecl,
4581 &stack_args_size, &locate);
4582 /* Adjust offsets to include the pretend args. */
4583 locate.slot_offset.constant += extra_pretend_bytes - pretend_bytes;
4584 locate.offset.constant += extra_pretend_bytes - pretend_bytes;
4588 unsigned int align, boundary;
4590 /* If we're passing this arg using a reg, make its stack home
4591 the aligned stack slot. */
4593 offset_rtx = ARGS_SIZE_RTX (locate.slot_offset);
4595 offset_rtx = ARGS_SIZE_RTX (locate.offset);
4597 if (offset_rtx == const0_rtx)
4598 stack_parm = gen_rtx_MEM (promoted_mode, internal_arg_pointer);
4600 stack_parm = gen_rtx_MEM (promoted_mode,
4601 gen_rtx_PLUS (Pmode,
4602 internal_arg_pointer,
4605 set_mem_attributes (stack_parm, parm, 1);
4607 boundary = FUNCTION_ARG_BOUNDARY (promoted_mode, passed_type);
4610 /* If we're padding upward, we know that the alignment of the slot
4611 is FUNCTION_ARG_BOUNDARY. If we're using slot_offset, we're
4612 intentionally forcing upward padding. Otherwise we have to come
4613 up with a guess at the alignment based on OFFSET_RTX. */
4614 if (locate.where_pad == upward || entry_parm)
4616 else if (GET_CODE (offset_rtx) == CONST_INT)
4618 align = INTVAL (offset_rtx) * BITS_PER_UNIT | boundary;
4619 align = align & -align;
4622 set_mem_align (stack_parm, align);
4625 set_reg_attrs_for_parm (entry_parm, stack_parm);
4628 /* If this parm was passed part in regs and part in memory,
4629 pretend it arrived entirely in memory
4630 by pushing the register-part onto the stack.
4632 In the special case of a DImode or DFmode that is split,
4633 we could put it together in a pseudoreg directly,
4634 but for now that's not worth bothering with. */
4638 /* Handle calls that pass values in multiple non-contiguous
4639 locations. The Irix 6 ABI has examples of this. */
4640 if (GET_CODE (entry_parm) == PARALLEL)
4641 emit_group_store (validize_mem (stack_parm), entry_parm,
4643 int_size_in_bytes (TREE_TYPE (parm)));
4646 move_block_from_reg (REGNO (entry_parm), validize_mem (stack_parm),
4649 entry_parm = stack_parm;
4652 /* If we didn't decide this parm came in a register,
4653 by default it came on the stack. */
4654 if (entry_parm == 0)
4655 entry_parm = stack_parm;
4657 /* Record permanently how this parm was passed. */
4658 set_decl_incoming_rtl (parm, entry_parm);
4660 /* If there is actually space on the stack for this parm,
4661 count it in stack_args_size; otherwise set stack_parm to 0
4662 to indicate there is no preallocated stack slot for the parm. */
4664 if (entry_parm == stack_parm
4665 || (GET_CODE (entry_parm) == PARALLEL
4666 && XEXP (XVECEXP (entry_parm, 0, 0), 0) == NULL_RTX)
4667 #if defined (REG_PARM_STACK_SPACE)
4668 /* On some machines, even if a parm value arrives in a register
4669 there is still an (uninitialized) stack slot allocated
4671 || REG_PARM_STACK_SPACE (fndecl) > 0
4675 stack_args_size.constant += locate.size.constant;
4676 if (locate.size.var)
4677 ADD_PARM_SIZE (stack_args_size, locate.size.var);
4680 /* No stack slot was pushed for this parm. */
4683 /* Update info on where next arg arrives in registers. */
4685 FUNCTION_ARG_ADVANCE (args_so_far, promoted_mode,
4686 passed_type, named_arg);
4688 /* If we can't trust the parm stack slot to be aligned enough
4689 for its ultimate type, don't use that slot after entry.
4690 We'll make another stack slot, if we need one. */
4691 if (STRICT_ALIGNMENT && stack_parm
4692 && GET_MODE_ALIGNMENT (nominal_mode) > MEM_ALIGN (stack_parm))
4695 /* If parm was passed in memory, and we need to convert it on entry,
4696 don't store it back in that same slot. */
4697 if (entry_parm == stack_parm
4698 && nominal_mode != BLKmode && nominal_mode != passed_mode)
4701 /* When an argument is passed in multiple locations, we can't
4702 make use of this information, but we can save some copying if
4703 the whole argument is passed in a single register. */
4704 if (GET_CODE (entry_parm) == PARALLEL
4705 && nominal_mode != BLKmode && passed_mode != BLKmode)
4707 int i, len = XVECLEN (entry_parm, 0);
4709 for (i = 0; i < len; i++)
4710 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
4711 && REG_P (XEXP (XVECEXP (entry_parm, 0, i), 0))
4712 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
4714 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
4716 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
4717 set_decl_incoming_rtl (parm, entry_parm);
4722 /* ENTRY_PARM is an RTX for the parameter as it arrives,
4723 in the mode in which it arrives.
4724 STACK_PARM is an RTX for a stack slot where the parameter can live
4725 during the function (in case we want to put it there).
4726 STACK_PARM is 0 if no stack slot was pushed for it.
4728 Now output code if necessary to convert ENTRY_PARM to
4729 the type in which this function declares it,
4730 and store that result in an appropriate place,
4731 which may be a pseudo reg, may be STACK_PARM,
4732 or may be a local stack slot if STACK_PARM is 0.
4734 Set DECL_RTL to that place. */
4736 if (GET_CODE (entry_parm) == PARALLEL && nominal_mode != BLKmode
4737 && XVECLEN (entry_parm, 0) > 1)
4739 /* Reconstitute objects the size of a register or larger using
4740 register operations instead of the stack. */
4741 rtx parmreg = gen_reg_rtx (nominal_mode);
4743 if (REG_P (parmreg))
4745 unsigned int regno = REGNO (parmreg);
4747 emit_group_store (parmreg, entry_parm, TREE_TYPE (parm),
4748 int_size_in_bytes (TREE_TYPE (parm)));
4749 SET_DECL_RTL (parm, parmreg);
4752 if (regno >= max_parm_reg)
4755 int old_max_parm_reg = max_parm_reg;
4757 /* It's slow to expand this one register at a time,
4758 but it's also rare and we need max_parm_reg to be
4759 precisely correct. */
4760 max_parm_reg = regno + 1;
4761 new = ggc_realloc (parm_reg_stack_loc,
4762 max_parm_reg * sizeof (rtx));
4763 memset (new + old_max_parm_reg, 0,
4764 (max_parm_reg - old_max_parm_reg) * sizeof (rtx));
4765 parm_reg_stack_loc = new;
4766 parm_reg_stack_loc[regno] = stack_parm;
4771 if (nominal_mode == BLKmode
4772 #ifdef BLOCK_REG_PADDING
4773 || (locate.where_pad == (BYTES_BIG_ENDIAN ? upward : downward)
4774 && GET_MODE_SIZE (promoted_mode) < UNITS_PER_WORD)
4776 || GET_CODE (entry_parm) == PARALLEL)
4778 /* If a BLKmode arrives in registers, copy it to a stack slot.
4779 Handle calls that pass values in multiple non-contiguous
4780 locations. The Irix 6 ABI has examples of this. */
4781 if (REG_P (entry_parm)
4782 || (GET_CODE (entry_parm) == PARALLEL
4783 && (!loaded_in_reg || !optimize)))
4785 int size = int_size_in_bytes (TREE_TYPE (parm));
4786 int size_stored = CEIL_ROUND (size, UNITS_PER_WORD);
4789 /* Note that we will be storing an integral number of words.
4790 So we have to be careful to ensure that we allocate an
4791 integral number of words. We do this below in the
4792 assign_stack_local if space was not allocated in the argument
4793 list. If it was, this will not work if PARM_BOUNDARY is not
4794 a multiple of BITS_PER_WORD. It isn't clear how to fix this
4795 if it becomes a problem. Exception is when BLKmode arrives
4796 with arguments not conforming to word_mode. */
4798 if (stack_parm == 0)
4800 stack_parm = assign_stack_local (BLKmode, size_stored, 0);
4801 PUT_MODE (stack_parm, GET_MODE (entry_parm));
4802 set_mem_attributes (stack_parm, parm, 1);
4804 else if (GET_CODE (entry_parm) == PARALLEL)
4806 else if (size != 0 && PARM_BOUNDARY % BITS_PER_WORD != 0)
4809 mem = validize_mem (stack_parm);
4811 /* Handle calls that pass values in multiple non-contiguous
4812 locations. The Irix 6 ABI has examples of this. */
4813 if (GET_CODE (entry_parm) == PARALLEL)
4814 emit_group_store (mem, entry_parm, TREE_TYPE (parm), size);
4819 /* If SIZE is that of a mode no bigger than a word, just use
4820 that mode's store operation. */
4821 else if (size <= UNITS_PER_WORD)
4823 enum machine_mode mode
4824 = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
4827 #ifdef BLOCK_REG_PADDING
4828 && (size == UNITS_PER_WORD
4829 || (BLOCK_REG_PADDING (mode, TREE_TYPE (parm), 1)
4830 != (BYTES_BIG_ENDIAN ? upward : downward)))
4834 rtx reg = gen_rtx_REG (mode, REGNO (entry_parm));
4835 emit_move_insn (change_address (mem, mode, 0), reg);
4838 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
4839 machine must be aligned to the left before storing
4840 to memory. Note that the previous test doesn't
4841 handle all cases (e.g. SIZE == 3). */
4842 else if (size != UNITS_PER_WORD
4843 #ifdef BLOCK_REG_PADDING
4844 && (BLOCK_REG_PADDING (mode, TREE_TYPE (parm), 1)
4852 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
4853 rtx reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
4855 x = expand_binop (word_mode, ashl_optab, reg,
4856 GEN_INT (by), 0, 1, OPTAB_WIDEN);
4857 tem = change_address (mem, word_mode, 0);
4858 emit_move_insn (tem, x);
4861 move_block_from_reg (REGNO (entry_parm), mem,
4862 size_stored / UNITS_PER_WORD);
4865 move_block_from_reg (REGNO (entry_parm), mem,
4866 size_stored / UNITS_PER_WORD);
4868 /* If parm is already bound to register pair, don't change
4870 if (! DECL_RTL_SET_P (parm))
4871 SET_DECL_RTL (parm, stack_parm);
4873 else if (! ((! optimize
4874 && ! DECL_REGISTER (parm))
4875 || TREE_SIDE_EFFECTS (parm)
4876 /* If -ffloat-store specified, don't put explicit
4877 float variables into registers. */
4878 || (flag_float_store
4879 && TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE))
4880 /* Always assign pseudo to structure return or item passed
4881 by invisible reference. */
4882 || passed_pointer || parm == function_result_decl)
4884 /* Store the parm in a pseudoregister during the function, but we
4885 may need to do it in a wider mode. */
4888 unsigned int regno, regnoi = 0, regnor = 0;
4890 unsignedp = TYPE_UNSIGNED (TREE_TYPE (parm));
4892 promoted_nominal_mode
4893 = promote_mode (TREE_TYPE (parm), nominal_mode, &unsignedp, 0);
4895 parmreg = gen_reg_rtx (promoted_nominal_mode);
4896 mark_user_reg (parmreg);
4898 /* If this was an item that we received a pointer to, set DECL_RTL
4902 rtx x = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (passed_type)),
4904 set_mem_attributes (x, parm, 1);
4905 SET_DECL_RTL (parm, x);
4909 SET_DECL_RTL (parm, parmreg);
4910 maybe_set_unchanging (DECL_RTL (parm), parm);
4913 /* Copy the value into the register. */
4914 if (nominal_mode != passed_mode
4915 || promoted_nominal_mode != promoted_mode)
4918 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
4919 mode, by the caller. We now have to convert it to
4920 NOMINAL_MODE, if different. However, PARMREG may be in
4921 a different mode than NOMINAL_MODE if it is being stored
4924 If ENTRY_PARM is a hard register, it might be in a register
4925 not valid for operating in its mode (e.g., an odd-numbered
4926 register for a DFmode). In that case, moves are the only
4927 thing valid, so we can't do a convert from there. This
4928 occurs when the calling sequence allow such misaligned
4931 In addition, the conversion may involve a call, which could
4932 clobber parameters which haven't been copied to pseudo
4933 registers yet. Therefore, we must first copy the parm to
4934 a pseudo reg here, and save the conversion until after all
4935 parameters have been moved. */
4937 rtx tempreg = gen_reg_rtx (GET_MODE (entry_parm));
4939 emit_move_insn (tempreg, validize_mem (entry_parm));
4941 push_to_sequence (conversion_insns);
4942 tempreg = convert_to_mode (nominal_mode, tempreg, unsignedp);
4944 if (GET_CODE (tempreg) == SUBREG
4945 && GET_MODE (tempreg) == nominal_mode
4946 && REG_P (SUBREG_REG (tempreg))
4947 && nominal_mode == passed_mode
4948 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (entry_parm)
4949 && GET_MODE_SIZE (GET_MODE (tempreg))
4950 < GET_MODE_SIZE (GET_MODE (entry_parm)))
4952 /* The argument is already sign/zero extended, so note it
4954 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
4955 SUBREG_PROMOTED_UNSIGNED_SET (tempreg, unsignedp);
4958 /* TREE_USED gets set erroneously during expand_assignment. */
4959 save_tree_used = TREE_USED (parm);
4960 expand_assignment (parm,
4961 make_tree (nominal_type, tempreg), 0);
4962 TREE_USED (parm) = save_tree_used;
4963 conversion_insns = get_insns ();
4968 emit_move_insn (parmreg, validize_mem (entry_parm));
4970 /* If we were passed a pointer but the actual value
4971 can safely live in a register, put it in one. */
4972 if (passed_pointer && TYPE_MODE (TREE_TYPE (parm)) != BLKmode
4973 /* If by-reference argument was promoted, demote it. */
4974 && (TYPE_MODE (TREE_TYPE (parm)) != GET_MODE (DECL_RTL (parm))
4976 && ! DECL_REGISTER (parm))
4977 || TREE_SIDE_EFFECTS (parm)
4978 /* If -ffloat-store specified, don't put explicit
4979 float variables into registers. */
4980 || (flag_float_store
4981 && TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE))))
4983 /* We can't use nominal_mode, because it will have been set to
4984 Pmode above. We must use the actual mode of the parm. */
4985 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
4986 mark_user_reg (parmreg);
4987 if (GET_MODE (parmreg) != GET_MODE (DECL_RTL (parm)))
4989 rtx tempreg = gen_reg_rtx (GET_MODE (DECL_RTL (parm)));
4990 int unsigned_p = TYPE_UNSIGNED (TREE_TYPE (parm));
4991 push_to_sequence (conversion_insns);
4992 emit_move_insn (tempreg, DECL_RTL (parm));
4994 convert_to_mode (GET_MODE (parmreg),
4997 emit_move_insn (parmreg, DECL_RTL (parm));
4998 conversion_insns = get_insns();
5003 emit_move_insn (parmreg, DECL_RTL (parm));
5004 SET_DECL_RTL (parm, parmreg);
5005 /* STACK_PARM is the pointer, not the parm, and PARMREG is
5009 #ifdef FUNCTION_ARG_CALLEE_COPIES
5010 /* If we are passed an arg by reference and it is our responsibility
5011 to make a copy, do it now.
5012 PASSED_TYPE and PASSED mode now refer to the pointer, not the
5013 original argument, so we must recreate them in the call to
5014 FUNCTION_ARG_CALLEE_COPIES. */
5015 /* ??? Later add code to handle the case that if the argument isn't
5016 modified, don't do the copy. */
5018 else if (passed_pointer
5019 && FUNCTION_ARG_CALLEE_COPIES (args_so_far,
5020 TYPE_MODE (TREE_TYPE (passed_type)),
5021 TREE_TYPE (passed_type),
5023 && ! TREE_ADDRESSABLE (TREE_TYPE (passed_type)))
5026 tree type = TREE_TYPE (passed_type);
5028 /* This sequence may involve a library call perhaps clobbering
5029 registers that haven't been copied to pseudos yet. */
5031 push_to_sequence (conversion_insns);
5033 if (!COMPLETE_TYPE_P (type)
5034 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
5035 /* This is a variable sized object. */
5036 copy = gen_rtx_MEM (BLKmode,
5037 allocate_dynamic_stack_space
5038 (expr_size (parm), NULL_RTX,
5039 TYPE_ALIGN (type)));
5041 copy = assign_stack_temp (TYPE_MODE (type),
5042 int_size_in_bytes (type), 1);
5043 set_mem_attributes (copy, parm, 1);
5045 store_expr (parm, copy, 0);
5046 emit_move_insn (parmreg, XEXP (copy, 0));
5047 conversion_insns = get_insns ();
5051 #endif /* FUNCTION_ARG_CALLEE_COPIES */
5053 /* In any case, record the parm's desired stack location
5054 in case we later discover it must live in the stack.
5056 If it is a COMPLEX value, store the stack location for both
5059 if (GET_CODE (parmreg) == CONCAT)
5060 regno = MAX (REGNO (XEXP (parmreg, 0)), REGNO (XEXP (parmreg, 1)));
5062 regno = REGNO (parmreg);
5064 if (regno >= max_parm_reg)
5067 int old_max_parm_reg = max_parm_reg;
5069 /* It's slow to expand this one register at a time,
5070 but it's also rare and we need max_parm_reg to be
5071 precisely correct. */
5072 max_parm_reg = regno + 1;
5073 new = ggc_realloc (parm_reg_stack_loc,
5074 max_parm_reg * sizeof (rtx));
5075 memset (new + old_max_parm_reg, 0,
5076 (max_parm_reg - old_max_parm_reg) * sizeof (rtx));
5077 parm_reg_stack_loc = new;
5080 if (GET_CODE (parmreg) == CONCAT)
5082 enum machine_mode submode = GET_MODE (XEXP (parmreg, 0));
5084 regnor = REGNO (gen_realpart (submode, parmreg));
5085 regnoi = REGNO (gen_imagpart (submode, parmreg));
5087 if (stack_parm != 0)
5089 parm_reg_stack_loc[regnor]
5090 = gen_realpart (submode, stack_parm);
5091 parm_reg_stack_loc[regnoi]
5092 = gen_imagpart (submode, stack_parm);
5096 parm_reg_stack_loc[regnor] = 0;
5097 parm_reg_stack_loc[regnoi] = 0;
5101 parm_reg_stack_loc[REGNO (parmreg)] = stack_parm;
5103 /* Mark the register as eliminable if we did no conversion
5104 and it was copied from memory at a fixed offset,
5105 and the arg pointer was not copied to a pseudo-reg.
5106 If the arg pointer is a pseudo reg or the offset formed
5107 an invalid address, such memory-equivalences
5108 as we make here would screw up life analysis for it. */
5109 if (nominal_mode == passed_mode
5112 && GET_CODE (stack_parm) == MEM
5113 && locate.offset.var == 0
5114 && reg_mentioned_p (virtual_incoming_args_rtx,
5115 XEXP (stack_parm, 0)))
5117 rtx linsn = get_last_insn ();
5120 /* Mark complex types separately. */
5121 if (GET_CODE (parmreg) == CONCAT)
5122 /* Scan backwards for the set of the real and
5124 for (sinsn = linsn; sinsn != 0;
5125 sinsn = prev_nonnote_insn (sinsn))
5127 set = single_set (sinsn);
5129 && SET_DEST (set) == regno_reg_rtx [regnoi])
5131 = gen_rtx_EXPR_LIST (REG_EQUIV,
5132 parm_reg_stack_loc[regnoi],
5135 && SET_DEST (set) == regno_reg_rtx [regnor])
5137 = gen_rtx_EXPR_LIST (REG_EQUIV,
5138 parm_reg_stack_loc[regnor],
5141 else if ((set = single_set (linsn)) != 0
5142 && SET_DEST (set) == parmreg)
5144 = gen_rtx_EXPR_LIST (REG_EQUIV,
5145 stack_parm, REG_NOTES (linsn));
5148 /* For pointer data type, suggest pointer register. */
5149 if (POINTER_TYPE_P (TREE_TYPE (parm)))
5150 mark_reg_pointer (parmreg,
5151 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
5153 /* If something wants our address, try to use ADDRESSOF. */
5154 if (TREE_ADDRESSABLE (parm))
5156 /* If we end up putting something into the stack,
5157 fixup_var_refs_insns will need to make a pass over
5158 all the instructions. It looks through the pending
5159 sequences -- but it can't see the ones in the
5160 CONVERSION_INSNS, if they're not on the sequence
5161 stack. So, we go back to that sequence, just so that
5162 the fixups will happen. */
5163 push_to_sequence (conversion_insns);
5164 put_var_into_stack (parm, /*rescan=*/true);
5165 conversion_insns = get_insns ();
5171 /* Value must be stored in the stack slot STACK_PARM
5172 during function execution. */
5174 if (promoted_mode != nominal_mode)
5176 /* Conversion is required. */
5177 rtx tempreg = gen_reg_rtx (GET_MODE (entry_parm));
5179 emit_move_insn (tempreg, validize_mem (entry_parm));
5181 push_to_sequence (conversion_insns);
5182 entry_parm = convert_to_mode (nominal_mode, tempreg,
5183 TYPE_UNSIGNED (TREE_TYPE (parm)));
5185 /* ??? This may need a big-endian conversion on sparc64. */
5186 stack_parm = adjust_address (stack_parm, nominal_mode, 0);
5188 conversion_insns = get_insns ();
5193 if (entry_parm != stack_parm)
5195 if (stack_parm == 0)
5198 = assign_stack_local (GET_MODE (entry_parm),
5199 GET_MODE_SIZE (GET_MODE (entry_parm)),
5201 set_mem_attributes (stack_parm, parm, 1);
5204 if (promoted_mode != nominal_mode)
5206 push_to_sequence (conversion_insns);
5207 emit_move_insn (validize_mem (stack_parm),
5208 validize_mem (entry_parm));
5209 conversion_insns = get_insns ();
5213 emit_move_insn (validize_mem (stack_parm),
5214 validize_mem (entry_parm));
5217 SET_DECL_RTL (parm, stack_parm);
5221 if (targetm.calls.split_complex_arg && fnargs != orig_fnargs)
5223 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm))
5225 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
5226 && targetm.calls.split_complex_arg (TREE_TYPE (parm)))
5228 rtx tmp, real, imag;
5229 enum machine_mode inner = GET_MODE_INNER (DECL_MODE (parm));
5231 real = DECL_RTL (fnargs);
5232 imag = DECL_RTL (TREE_CHAIN (fnargs));
5233 if (inner != GET_MODE (real))
5235 real = gen_lowpart_SUBREG (inner, real);
5236 imag = gen_lowpart_SUBREG (inner, imag);
5238 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
5239 SET_DECL_RTL (parm, tmp);
5241 real = DECL_INCOMING_RTL (fnargs);
5242 imag = DECL_INCOMING_RTL (TREE_CHAIN (fnargs));
5243 if (inner != GET_MODE (real))
5245 real = gen_lowpart_SUBREG (inner, real);
5246 imag = gen_lowpart_SUBREG (inner, imag);
5248 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
5249 set_decl_incoming_rtl (parm, tmp);
5250 fnargs = TREE_CHAIN (fnargs);
5254 SET_DECL_RTL (parm, DECL_RTL (fnargs));
5255 set_decl_incoming_rtl (parm, DECL_INCOMING_RTL (fnargs));
5257 /* Set MEM_EXPR to the original decl, i.e. to PARM,
5258 instead of the copy of decl, i.e. FNARGS. */
5259 if (DECL_INCOMING_RTL (parm)
5260 && GET_CODE (DECL_INCOMING_RTL (parm)) == MEM)
5261 set_mem_expr (DECL_INCOMING_RTL (parm), parm);
5263 fnargs = TREE_CHAIN (fnargs);
5267 /* Output all parameter conversion instructions (possibly including calls)
5268 now that all parameters have been copied out of hard registers. */
5269 emit_insn (conversion_insns);
5271 /* If we are receiving a struct value address as the first argument, set up
5272 the RTL for the function result. As this might require code to convert
5273 the transmitted address to Pmode, we do this here to ensure that possible
5274 preliminary conversions of the address have been emitted already. */
5275 if (function_result_decl)
5277 tree result = DECL_RESULT (fndecl);
5278 rtx addr = DECL_RTL (function_result_decl);
5281 addr = convert_memory_address (Pmode, addr);
5282 x = gen_rtx_MEM (DECL_MODE (result), addr);
5283 set_mem_attributes (x, result, 1);
5284 SET_DECL_RTL (result, x);
5287 /* We have aligned all the args, so add space for the pretend args. */
5288 stack_args_size.constant += extra_pretend_bytes;
5289 current_function_args_size = stack_args_size.constant;
5291 /* Adjust function incoming argument size for alignment and
5294 #ifdef REG_PARM_STACK_SPACE
5295 current_function_args_size = MAX (current_function_args_size,
5296 REG_PARM_STACK_SPACE (fndecl));
5299 current_function_args_size
5300 = ((current_function_args_size + STACK_BYTES - 1)
5301 / STACK_BYTES) * STACK_BYTES;
5303 #ifdef ARGS_GROW_DOWNWARD
5304 current_function_arg_offset_rtx
5305 = (stack_args_size.var == 0 ? GEN_INT (-stack_args_size.constant)
5306 : expand_expr (size_diffop (stack_args_size.var,
5307 size_int (-stack_args_size.constant)),
5308 NULL_RTX, VOIDmode, 0));
5310 current_function_arg_offset_rtx = ARGS_SIZE_RTX (stack_args_size);
5313 /* See how many bytes, if any, of its args a function should try to pop
5316 current_function_pops_args = RETURN_POPS_ARGS (fndecl, TREE_TYPE (fndecl),
5317 current_function_args_size);
5319 /* For stdarg.h function, save info about
5320 regs and stack space used by the named args. */
5322 current_function_args_info = args_so_far;
5324 /* Set the rtx used for the function return value. Put this in its
5325 own variable so any optimizers that need this information don't have
5326 to include tree.h. Do this here so it gets done when an inlined
5327 function gets output. */
5329 current_function_return_rtx
5330 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
5331 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
5333 /* If scalar return value was computed in a pseudo-reg, or was a named
5334 return value that got dumped to the stack, copy that to the hard
5336 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
5338 tree decl_result = DECL_RESULT (fndecl);
5339 rtx decl_rtl = DECL_RTL (decl_result);
5341 if (REG_P (decl_rtl)
5342 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
5343 : DECL_REGISTER (decl_result))
5347 #ifdef FUNCTION_OUTGOING_VALUE
5348 real_decl_rtl = FUNCTION_OUTGOING_VALUE (TREE_TYPE (decl_result),
5351 real_decl_rtl = FUNCTION_VALUE (TREE_TYPE (decl_result),
5354 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
5355 /* The delay slot scheduler assumes that current_function_return_rtx
5356 holds the hard register containing the return value, not a
5357 temporary pseudo. */
5358 current_function_return_rtx = real_decl_rtl;
5363 /* If ARGS contains entries with complex types, split the entry into two
5364 entries of the component type. Return a new list of substitutions are
5365 needed, else the old list. */
5368 split_complex_args (tree args)
5372 /* Before allocating memory, check for the common case of no complex. */
5373 for (p = args; p; p = TREE_CHAIN (p))
5375 tree type = TREE_TYPE (p);
5376 if (TREE_CODE (type) == COMPLEX_TYPE
5377 && targetm.calls.split_complex_arg (type))
5383 args = copy_list (args);
5385 for (p = args; p; p = TREE_CHAIN (p))
5387 tree type = TREE_TYPE (p);
5388 if (TREE_CODE (type) == COMPLEX_TYPE
5389 && targetm.calls.split_complex_arg (type))
5392 tree subtype = TREE_TYPE (type);
5394 /* Rewrite the PARM_DECL's type with its component. */
5395 TREE_TYPE (p) = subtype;
5396 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
5397 DECL_MODE (p) = VOIDmode;
5398 DECL_SIZE (p) = NULL;
5399 DECL_SIZE_UNIT (p) = NULL;
5402 /* Build a second synthetic decl. */
5403 decl = build_decl (PARM_DECL, NULL_TREE, subtype);
5404 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
5405 layout_decl (decl, 0);
5407 /* Splice it in; skip the new decl. */
5408 TREE_CHAIN (decl) = TREE_CHAIN (p);
5409 TREE_CHAIN (p) = decl;
5417 /* Indicate whether REGNO is an incoming argument to the current function
5418 that was promoted to a wider mode. If so, return the RTX for the
5419 register (to get its mode). PMODE and PUNSIGNEDP are set to the mode
5420 that REGNO is promoted from and whether the promotion was signed or
5424 promoted_input_arg (unsigned int regno, enum machine_mode *pmode, int *punsignedp)
5428 for (arg = DECL_ARGUMENTS (current_function_decl); arg;
5429 arg = TREE_CHAIN (arg))
5430 if (REG_P (DECL_INCOMING_RTL (arg))
5431 && REGNO (DECL_INCOMING_RTL (arg)) == regno
5432 && TYPE_MODE (DECL_ARG_TYPE (arg)) == TYPE_MODE (TREE_TYPE (arg)))
5434 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg));
5435 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (arg));
5437 mode = promote_mode (TREE_TYPE (arg), mode, &unsignedp, 1);
5438 if (mode == GET_MODE (DECL_INCOMING_RTL (arg))
5439 && mode != DECL_MODE (arg))
5441 *pmode = DECL_MODE (arg);
5442 *punsignedp = unsignedp;
5443 return DECL_INCOMING_RTL (arg);
5451 /* Compute the size and offset from the start of the stacked arguments for a
5452 parm passed in mode PASSED_MODE and with type TYPE.
5454 INITIAL_OFFSET_PTR points to the current offset into the stacked
5457 The starting offset and size for this parm are returned in
5458 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
5459 nonzero, the offset is that of stack slot, which is returned in
5460 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
5461 padding required from the initial offset ptr to the stack slot.
5463 IN_REGS is nonzero if the argument will be passed in registers. It will
5464 never be set if REG_PARM_STACK_SPACE is not defined.
5466 FNDECL is the function in which the argument was defined.
5468 There are two types of rounding that are done. The first, controlled by
5469 FUNCTION_ARG_BOUNDARY, forces the offset from the start of the argument
5470 list to be aligned to the specific boundary (in bits). This rounding
5471 affects the initial and starting offsets, but not the argument size.
5473 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
5474 optionally rounds the size of the parm to PARM_BOUNDARY. The
5475 initial offset is not affected by this rounding, while the size always
5476 is and the starting offset may be. */
5478 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
5479 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
5480 callers pass in the total size of args so far as
5481 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
5484 locate_and_pad_parm (enum machine_mode passed_mode, tree type, int in_regs,
5485 int partial, tree fndecl ATTRIBUTE_UNUSED,
5486 struct args_size *initial_offset_ptr,
5487 struct locate_and_pad_arg_data *locate)
5490 enum direction where_pad;
5492 int reg_parm_stack_space = 0;
5493 int part_size_in_regs;
5495 #ifdef REG_PARM_STACK_SPACE
5496 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
5498 /* If we have found a stack parm before we reach the end of the
5499 area reserved for registers, skip that area. */
5502 if (reg_parm_stack_space > 0)
5504 if (initial_offset_ptr->var)
5506 initial_offset_ptr->var
5507 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
5508 ssize_int (reg_parm_stack_space));
5509 initial_offset_ptr->constant = 0;
5511 else if (initial_offset_ptr->constant < reg_parm_stack_space)
5512 initial_offset_ptr->constant = reg_parm_stack_space;
5515 #endif /* REG_PARM_STACK_SPACE */
5517 part_size_in_regs = 0;
5518 if (reg_parm_stack_space == 0)
5519 part_size_in_regs = ((partial * UNITS_PER_WORD)
5520 / (PARM_BOUNDARY / BITS_PER_UNIT)
5521 * (PARM_BOUNDARY / BITS_PER_UNIT));
5524 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
5525 where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
5526 boundary = FUNCTION_ARG_BOUNDARY (passed_mode, type);
5527 locate->where_pad = where_pad;
5529 #ifdef ARGS_GROW_DOWNWARD
5530 locate->slot_offset.constant = -initial_offset_ptr->constant;
5531 if (initial_offset_ptr->var)
5532 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
5533 initial_offset_ptr->var);
5537 if (where_pad != none
5538 && (!host_integerp (sizetree, 1)
5539 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
5540 s2 = round_up (s2, PARM_BOUNDARY / BITS_PER_UNIT);
5541 SUB_PARM_SIZE (locate->slot_offset, s2);
5544 locate->slot_offset.constant += part_size_in_regs;
5547 #ifdef REG_PARM_STACK_SPACE
5548 || REG_PARM_STACK_SPACE (fndecl) > 0
5551 pad_to_arg_alignment (&locate->slot_offset, boundary,
5552 &locate->alignment_pad);
5554 locate->size.constant = (-initial_offset_ptr->constant
5555 - locate->slot_offset.constant);
5556 if (initial_offset_ptr->var)
5557 locate->size.var = size_binop (MINUS_EXPR,
5558 size_binop (MINUS_EXPR,
5560 initial_offset_ptr->var),
5561 locate->slot_offset.var);
5563 /* Pad_below needs the pre-rounded size to know how much to pad
5565 locate->offset = locate->slot_offset;
5566 if (where_pad == downward)
5567 pad_below (&locate->offset, passed_mode, sizetree);
5569 #else /* !ARGS_GROW_DOWNWARD */
5571 #ifdef REG_PARM_STACK_SPACE
5572 || REG_PARM_STACK_SPACE (fndecl) > 0
5575 pad_to_arg_alignment (initial_offset_ptr, boundary,
5576 &locate->alignment_pad);
5577 locate->slot_offset = *initial_offset_ptr;
5579 #ifdef PUSH_ROUNDING
5580 if (passed_mode != BLKmode)
5581 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
5584 /* Pad_below needs the pre-rounded size to know how much to pad below
5585 so this must be done before rounding up. */
5586 locate->offset = locate->slot_offset;
5587 if (where_pad == downward)
5588 pad_below (&locate->offset, passed_mode, sizetree);
5590 if (where_pad != none
5591 && (!host_integerp (sizetree, 1)
5592 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
5593 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
5595 ADD_PARM_SIZE (locate->size, sizetree);
5597 locate->size.constant -= part_size_in_regs;
5598 #endif /* ARGS_GROW_DOWNWARD */
5601 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
5602 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
5605 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
5606 struct args_size *alignment_pad)
5608 tree save_var = NULL_TREE;
5609 HOST_WIDE_INT save_constant = 0;
5610 int boundary_in_bytes = boundary / BITS_PER_UNIT;
5611 HOST_WIDE_INT sp_offset = STACK_POINTER_OFFSET;
5613 #ifdef SPARC_STACK_BOUNDARY_HACK
5614 /* The sparc port has a bug. It sometimes claims a STACK_BOUNDARY
5615 higher than the real alignment of %sp. However, when it does this,
5616 the alignment of %sp+STACK_POINTER_OFFSET will be STACK_BOUNDARY.
5617 This is a temporary hack while the sparc port is fixed. */
5618 if (SPARC_STACK_BOUNDARY_HACK)
5622 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
5624 save_var = offset_ptr->var;
5625 save_constant = offset_ptr->constant;
5628 alignment_pad->var = NULL_TREE;
5629 alignment_pad->constant = 0;
5631 if (boundary > BITS_PER_UNIT)
5633 if (offset_ptr->var)
5635 tree sp_offset_tree = ssize_int (sp_offset);
5636 tree offset = size_binop (PLUS_EXPR,
5637 ARGS_SIZE_TREE (*offset_ptr),
5639 #ifdef ARGS_GROW_DOWNWARD
5640 tree rounded = round_down (offset, boundary / BITS_PER_UNIT);
5642 tree rounded = round_up (offset, boundary / BITS_PER_UNIT);
5645 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
5646 /* ARGS_SIZE_TREE includes constant term. */
5647 offset_ptr->constant = 0;
5648 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
5649 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
5654 offset_ptr->constant = -sp_offset +
5655 #ifdef ARGS_GROW_DOWNWARD
5656 FLOOR_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
5658 CEIL_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
5660 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
5661 alignment_pad->constant = offset_ptr->constant - save_constant;
5667 pad_below (struct args_size *offset_ptr, enum machine_mode passed_mode, tree sizetree)
5669 if (passed_mode != BLKmode)
5671 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
5672 offset_ptr->constant
5673 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
5674 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
5675 - GET_MODE_SIZE (passed_mode));
5679 if (TREE_CODE (sizetree) != INTEGER_CST
5680 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
5682 /* Round the size up to multiple of PARM_BOUNDARY bits. */
5683 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
5685 ADD_PARM_SIZE (*offset_ptr, s2);
5686 SUB_PARM_SIZE (*offset_ptr, sizetree);
5691 /* Walk the tree of blocks describing the binding levels within a function
5692 and warn about variables the might be killed by setjmp or vfork.
5693 This is done after calling flow_analysis and before global_alloc
5694 clobbers the pseudo-regs to hard regs. */
5697 setjmp_vars_warning (tree block)
5701 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
5703 if (TREE_CODE (decl) == VAR_DECL
5704 && DECL_RTL_SET_P (decl)
5705 && REG_P (DECL_RTL (decl))
5706 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
5707 warning ("%Jvariable '%D' might be clobbered by `longjmp' or `vfork'",
5711 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
5712 setjmp_vars_warning (sub);
5715 /* Do the appropriate part of setjmp_vars_warning
5716 but for arguments instead of local variables. */
5719 setjmp_args_warning (void)
5722 for (decl = DECL_ARGUMENTS (current_function_decl);
5723 decl; decl = TREE_CHAIN (decl))
5724 if (DECL_RTL (decl) != 0
5725 && REG_P (DECL_RTL (decl))
5726 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
5727 warning ("%Jargument '%D' might be clobbered by `longjmp' or `vfork'",
5731 /* If this function call setjmp, put all vars into the stack
5732 unless they were declared `register'. */
5735 setjmp_protect (tree block)
5738 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
5739 if ((TREE_CODE (decl) == VAR_DECL
5740 || TREE_CODE (decl) == PARM_DECL)
5741 && DECL_RTL (decl) != 0
5742 && (REG_P (DECL_RTL (decl))
5743 || (GET_CODE (DECL_RTL (decl)) == MEM
5744 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == ADDRESSOF))
5745 /* If this variable came from an inline function, it must be
5746 that its life doesn't overlap the setjmp. If there was a
5747 setjmp in the function, it would already be in memory. We
5748 must exclude such variable because their DECL_RTL might be
5749 set to strange things such as virtual_stack_vars_rtx. */
5750 && ! DECL_FROM_INLINE (decl)
5752 #ifdef NON_SAVING_SETJMP
5753 /* If longjmp doesn't restore the registers,
5754 don't put anything in them. */
5758 ! DECL_REGISTER (decl)))
5759 put_var_into_stack (decl, /*rescan=*/true);
5760 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
5761 setjmp_protect (sub);
5764 /* Like the previous function, but for args instead of local variables. */
5767 setjmp_protect_args (void)
5770 for (decl = DECL_ARGUMENTS (current_function_decl);
5771 decl; decl = TREE_CHAIN (decl))
5772 if ((TREE_CODE (decl) == VAR_DECL
5773 || TREE_CODE (decl) == PARM_DECL)
5774 && DECL_RTL (decl) != 0
5775 && (REG_P (DECL_RTL (decl))
5776 || (GET_CODE (DECL_RTL (decl)) == MEM
5777 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == ADDRESSOF))
5779 /* If longjmp doesn't restore the registers,
5780 don't put anything in them. */
5781 #ifdef NON_SAVING_SETJMP
5785 ! DECL_REGISTER (decl)))
5786 put_var_into_stack (decl, /*rescan=*/true);
5789 /* Convert a stack slot address ADDR for variable VAR
5790 (from a containing function)
5791 into an address valid in this function (using a static chain). */
5794 fix_lexical_addr (rtx addr, tree var)
5797 HOST_WIDE_INT displacement;
5798 tree context = decl_function_context (var);
5799 struct function *fp;
5802 /* If this is the present function, we need not do anything. */
5803 if (context == current_function_decl)
5806 fp = find_function_data (context);
5808 if (GET_CODE (addr) == ADDRESSOF && GET_CODE (XEXP (addr, 0)) == MEM)
5809 addr = XEXP (XEXP (addr, 0), 0);
5811 /* Decode given address as base reg plus displacement. */
5813 basereg = addr, displacement = 0;
5814 else if (GET_CODE (addr) == PLUS && GET_CODE (XEXP (addr, 1)) == CONST_INT)
5815 basereg = XEXP (addr, 0), displacement = INTVAL (XEXP (addr, 1));
5822 /* Use same offset, relative to appropriate static chain or argument
5824 return plus_constant (base, displacement);
5827 /* Put all this function's BLOCK nodes including those that are chained
5828 onto the first block into a vector, and return it.
5829 Also store in each NOTE for the beginning or end of a block
5830 the index of that block in the vector.
5831 The arguments are BLOCK, the chain of top-level blocks of the function,
5832 and INSNS, the insn chain of the function. */
5835 identify_blocks (void)
5838 tree *block_vector, *last_block_vector;
5840 tree block = DECL_INITIAL (current_function_decl);
5845 /* Fill the BLOCK_VECTOR with all of the BLOCKs in this function, in
5846 depth-first order. */
5847 block_vector = get_block_vector (block, &n_blocks);
5848 block_stack = xmalloc (n_blocks * sizeof (tree));
5850 last_block_vector = identify_blocks_1 (get_insns (),
5852 block_vector + n_blocks,
5855 /* If we didn't use all of the subblocks, we've misplaced block notes. */
5856 /* ??? This appears to happen all the time. Latent bugs elsewhere? */
5857 if (0 && last_block_vector != block_vector + n_blocks)
5860 free (block_vector);
5864 /* Subroutine of identify_blocks. Do the block substitution on the
5865 insn chain beginning with INSNS.
5867 BLOCK_STACK is pushed and popped for each BLOCK_BEGIN/BLOCK_END pair.
5868 BLOCK_VECTOR is incremented for each block seen. */
5871 identify_blocks_1 (rtx insns, tree *block_vector, tree *end_block_vector,
5872 tree *orig_block_stack)
5875 tree *block_stack = orig_block_stack;
5877 for (insn = insns; insn; insn = NEXT_INSN (insn))
5879 if (GET_CODE (insn) == NOTE)
5881 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
5885 /* If there are more block notes than BLOCKs, something
5887 if (block_vector == end_block_vector)
5890 b = *block_vector++;
5891 NOTE_BLOCK (insn) = b;
5894 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
5896 /* If there are more NOTE_INSN_BLOCK_ENDs than
5897 NOTE_INSN_BLOCK_BEGs, something is badly wrong. */
5898 if (block_stack == orig_block_stack)
5901 NOTE_BLOCK (insn) = *--block_stack;
5906 /* If there are more NOTE_INSN_BLOCK_BEGINs than NOTE_INSN_BLOCK_ENDs,
5907 something is badly wrong. */
5908 if (block_stack != orig_block_stack)
5911 return block_vector;
5914 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
5915 and create duplicate blocks. */
5916 /* ??? Need an option to either create block fragments or to create
5917 abstract origin duplicates of a source block. It really depends
5918 on what optimization has been performed. */
5921 reorder_blocks (void)
5923 tree block = DECL_INITIAL (current_function_decl);
5924 varray_type block_stack;
5926 if (block == NULL_TREE)
5929 VARRAY_TREE_INIT (block_stack, 10, "block_stack");
5931 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
5932 clear_block_marks (block);
5934 /* Prune the old trees away, so that they don't get in the way. */
5935 BLOCK_SUBBLOCKS (block) = NULL_TREE;
5936 BLOCK_CHAIN (block) = NULL_TREE;
5938 /* Recreate the block tree from the note nesting. */
5939 reorder_blocks_1 (get_insns (), block, &block_stack);
5940 BLOCK_SUBBLOCKS (block) = blocks_nreverse (BLOCK_SUBBLOCKS (block));
5942 /* Remove deleted blocks from the block fragment chains. */
5943 reorder_fix_fragments (block);
5946 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
5949 clear_block_marks (tree block)
5953 TREE_ASM_WRITTEN (block) = 0;
5954 clear_block_marks (BLOCK_SUBBLOCKS (block));
5955 block = BLOCK_CHAIN (block);
5960 reorder_blocks_1 (rtx insns, tree current_block, varray_type *p_block_stack)
5964 for (insn = insns; insn; insn = NEXT_INSN (insn))
5966 if (GET_CODE (insn) == NOTE)
5968 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
5970 tree block = NOTE_BLOCK (insn);
5972 /* If we have seen this block before, that means it now
5973 spans multiple address regions. Create a new fragment. */
5974 if (TREE_ASM_WRITTEN (block))
5976 tree new_block = copy_node (block);
5979 origin = (BLOCK_FRAGMENT_ORIGIN (block)
5980 ? BLOCK_FRAGMENT_ORIGIN (block)
5982 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
5983 BLOCK_FRAGMENT_CHAIN (new_block)
5984 = BLOCK_FRAGMENT_CHAIN (origin);
5985 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
5987 NOTE_BLOCK (insn) = new_block;
5991 BLOCK_SUBBLOCKS (block) = 0;
5992 TREE_ASM_WRITTEN (block) = 1;
5993 /* When there's only one block for the entire function,
5994 current_block == block and we mustn't do this, it
5995 will cause infinite recursion. */
5996 if (block != current_block)
5998 BLOCK_SUPERCONTEXT (block) = current_block;
5999 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
6000 BLOCK_SUBBLOCKS (current_block) = block;
6001 current_block = block;
6003 VARRAY_PUSH_TREE (*p_block_stack, block);
6005 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
6007 NOTE_BLOCK (insn) = VARRAY_TOP_TREE (*p_block_stack);
6008 VARRAY_POP (*p_block_stack);
6009 BLOCK_SUBBLOCKS (current_block)
6010 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block));
6011 current_block = BLOCK_SUPERCONTEXT (current_block);
6017 /* Rationalize BLOCK_FRAGMENT_ORIGIN. If an origin block no longer
6018 appears in the block tree, select one of the fragments to become
6019 the new origin block. */
6022 reorder_fix_fragments (tree block)
6026 tree dup_origin = BLOCK_FRAGMENT_ORIGIN (block);
6027 tree new_origin = NULL_TREE;
6031 if (! TREE_ASM_WRITTEN (dup_origin))
6033 new_origin = BLOCK_FRAGMENT_CHAIN (dup_origin);
6035 /* Find the first of the remaining fragments. There must
6036 be at least one -- the current block. */
6037 while (! TREE_ASM_WRITTEN (new_origin))
6038 new_origin = BLOCK_FRAGMENT_CHAIN (new_origin);
6039 BLOCK_FRAGMENT_ORIGIN (new_origin) = NULL_TREE;
6042 else if (! dup_origin)
6045 /* Re-root the rest of the fragments to the new origin. In the
6046 case that DUP_ORIGIN was null, that means BLOCK was the origin
6047 of a chain of fragments and we want to remove those fragments
6048 that didn't make it to the output. */
6051 tree *pp = &BLOCK_FRAGMENT_CHAIN (new_origin);
6056 if (TREE_ASM_WRITTEN (chain))
6058 BLOCK_FRAGMENT_ORIGIN (chain) = new_origin;
6060 pp = &BLOCK_FRAGMENT_CHAIN (chain);
6062 chain = BLOCK_FRAGMENT_CHAIN (chain);
6067 reorder_fix_fragments (BLOCK_SUBBLOCKS (block));
6068 block = BLOCK_CHAIN (block);
6072 /* Reverse the order of elements in the chain T of blocks,
6073 and return the new head of the chain (old last element). */
6076 blocks_nreverse (tree t)
6078 tree prev = 0, decl, next;
6079 for (decl = t; decl; decl = next)
6081 next = BLOCK_CHAIN (decl);
6082 BLOCK_CHAIN (decl) = prev;
6088 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
6089 non-NULL, list them all into VECTOR, in a depth-first preorder
6090 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
6094 all_blocks (tree block, tree *vector)
6100 TREE_ASM_WRITTEN (block) = 0;
6102 /* Record this block. */
6104 vector[n_blocks] = block;
6108 /* Record the subblocks, and their subblocks... */
6109 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
6110 vector ? vector + n_blocks : 0);
6111 block = BLOCK_CHAIN (block);
6117 /* Return a vector containing all the blocks rooted at BLOCK. The
6118 number of elements in the vector is stored in N_BLOCKS_P. The
6119 vector is dynamically allocated; it is the caller's responsibility
6120 to call `free' on the pointer returned. */
6123 get_block_vector (tree block, int *n_blocks_p)
6127 *n_blocks_p = all_blocks (block, NULL);
6128 block_vector = xmalloc (*n_blocks_p * sizeof (tree));
6129 all_blocks (block, block_vector);
6131 return block_vector;
6134 static GTY(()) int next_block_index = 2;
6136 /* Set BLOCK_NUMBER for all the blocks in FN. */
6139 number_blocks (tree fn)
6145 /* For SDB and XCOFF debugging output, we start numbering the blocks
6146 from 1 within each function, rather than keeping a running
6148 #if defined (SDB_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
6149 if (write_symbols == SDB_DEBUG || write_symbols == XCOFF_DEBUG)
6150 next_block_index = 1;
6153 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
6155 /* The top-level BLOCK isn't numbered at all. */
6156 for (i = 1; i < n_blocks; ++i)
6157 /* We number the blocks from two. */
6158 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
6160 free (block_vector);
6165 /* If VAR is present in a subblock of BLOCK, return the subblock. */
6168 debug_find_var_in_block_tree (tree var, tree block)
6172 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
6176 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
6178 tree ret = debug_find_var_in_block_tree (var, t);
6186 /* Allocate a function structure for FNDECL and set its contents
6190 allocate_struct_function (tree fndecl)
6193 tree fntype = fndecl ? TREE_TYPE (fndecl) : NULL_TREE;
6195 cfun = ggc_alloc_cleared (sizeof (struct function));
6197 max_parm_reg = LAST_VIRTUAL_REGISTER + 1;
6199 cfun->stack_alignment_needed = STACK_BOUNDARY;
6200 cfun->preferred_stack_boundary = STACK_BOUNDARY;
6202 current_function_funcdef_no = funcdef_no++;
6204 cfun->function_frequency = FUNCTION_FREQUENCY_NORMAL;
6206 init_stmt_for_function ();
6207 init_eh_for_function ();
6209 lang_hooks.function.init (cfun);
6210 if (init_machine_status)
6211 cfun->machine = (*init_machine_status) ();
6216 DECL_STRUCT_FUNCTION (fndecl) = cfun;
6217 cfun->decl = fndecl;
6219 result = DECL_RESULT (fndecl);
6220 if (aggregate_value_p (result, fndecl))
6222 #ifdef PCC_STATIC_STRUCT_RETURN
6223 current_function_returns_pcc_struct = 1;
6225 current_function_returns_struct = 1;
6228 current_function_returns_pointer = POINTER_TYPE_P (TREE_TYPE (result));
6230 current_function_stdarg
6232 && TYPE_ARG_TYPES (fntype) != 0
6233 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
6234 != void_type_node));
6237 /* Reset cfun, and other non-struct-function variables to defaults as
6238 appropriate for emitting rtl at the start of a function. */
6241 prepare_function_start (tree fndecl)
6243 if (fndecl && DECL_STRUCT_FUNCTION (fndecl))
6244 cfun = DECL_STRUCT_FUNCTION (fndecl);
6246 allocate_struct_function (fndecl);
6248 init_varasm_status (cfun);
6251 cse_not_expected = ! optimize;
6253 /* Caller save not needed yet. */
6254 caller_save_needed = 0;
6256 /* We haven't done register allocation yet. */
6259 /* Indicate that we need to distinguish between the return value of the
6260 present function and the return value of a function being called. */
6261 rtx_equal_function_value_matters = 1;
6263 /* Indicate that we have not instantiated virtual registers yet. */
6264 virtuals_instantiated = 0;
6266 /* Indicate that we want CONCATs now. */
6267 generating_concat_p = 1;
6269 /* Indicate we have no need of a frame pointer yet. */
6270 frame_pointer_needed = 0;
6273 /* Initialize the rtl expansion mechanism so that we can do simple things
6274 like generate sequences. This is used to provide a context during global
6275 initialization of some passes. */
6277 init_dummy_function_start (void)
6279 prepare_function_start (NULL);
6282 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
6283 and initialize static variables for generating RTL for the statements
6287 init_function_start (tree subr)
6289 prepare_function_start (subr);
6291 /* Prevent ever trying to delete the first instruction of a
6292 function. Also tell final how to output a linenum before the
6293 function prologue. Note linenums could be missing, e.g. when
6294 compiling a Java .class file. */
6295 if (! DECL_IS_BUILTIN (subr))
6296 emit_line_note (DECL_SOURCE_LOCATION (subr));
6298 /* Make sure first insn is a note even if we don't want linenums.
6299 This makes sure the first insn will never be deleted.
6300 Also, final expects a note to appear there. */
6301 emit_note (NOTE_INSN_DELETED);
6303 /* Warn if this value is an aggregate type,
6304 regardless of which calling convention we are using for it. */
6305 if (warn_aggregate_return
6306 && AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
6307 warning ("function returns an aggregate");
6310 /* Make sure all values used by the optimization passes have sane
6313 init_function_for_compilation (void)
6317 /* No prologue/epilogue insns yet. */
6318 VARRAY_GROW (prologue, 0);
6319 VARRAY_GROW (epilogue, 0);
6320 VARRAY_GROW (sibcall_epilogue, 0);
6323 /* Expand a call to __main at the beginning of a possible main function. */
6325 #if defined(INIT_SECTION_ASM_OP) && !defined(INVOKE__main)
6326 #undef HAS_INIT_SECTION
6327 #define HAS_INIT_SECTION
6331 expand_main_function (void)
6333 #ifdef FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN
6334 if (FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN)
6336 int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
6340 /* Forcibly align the stack. */
6341 #ifdef STACK_GROWS_DOWNWARD
6342 tmp = expand_simple_binop (Pmode, AND, stack_pointer_rtx, GEN_INT(-align),
6343 stack_pointer_rtx, 1, OPTAB_WIDEN);
6345 tmp = expand_simple_binop (Pmode, PLUS, stack_pointer_rtx,
6346 GEN_INT (align - 1), NULL_RTX, 1, OPTAB_WIDEN);
6347 tmp = expand_simple_binop (Pmode, AND, tmp, GEN_INT (-align),
6348 stack_pointer_rtx, 1, OPTAB_WIDEN);
6350 if (tmp != stack_pointer_rtx)
6351 emit_move_insn (stack_pointer_rtx, tmp);
6353 /* Enlist allocate_dynamic_stack_space to pick up the pieces. */
6354 tmp = force_reg (Pmode, const0_rtx);
6355 allocate_dynamic_stack_space (tmp, NULL_RTX, BIGGEST_ALIGNMENT);
6359 for (tmp = get_last_insn (); tmp; tmp = PREV_INSN (tmp))
6360 if (NOTE_P (tmp) && NOTE_LINE_NUMBER (tmp) == NOTE_INSN_FUNCTION_BEG)
6363 emit_insn_before (seq, tmp);
6369 #ifndef HAS_INIT_SECTION
6370 emit_library_call (init_one_libfunc (NAME__MAIN), LCT_NORMAL, VOIDmode, 0);
6374 /* The PENDING_SIZES represent the sizes of variable-sized types.
6375 Create RTL for the various sizes now (using temporary variables),
6376 so that we can refer to the sizes from the RTL we are generating
6377 for the current function. The PENDING_SIZES are a TREE_LIST. The
6378 TREE_VALUE of each node is a SAVE_EXPR. */
6381 expand_pending_sizes (tree pending_sizes)
6385 /* Evaluate now the sizes of any types declared among the arguments. */
6386 for (tem = pending_sizes; tem; tem = TREE_CHAIN (tem))
6388 expand_expr (TREE_VALUE (tem), const0_rtx, VOIDmode, 0);
6389 /* Flush the queue in case this parameter declaration has
6395 /* Start the RTL for a new function, and set variables used for
6397 SUBR is the FUNCTION_DECL node.
6398 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
6399 the function's parameters, which must be run at any return statement. */
6402 expand_function_start (tree subr, int parms_have_cleanups)
6404 /* Make sure volatile mem refs aren't considered
6405 valid operands of arithmetic insns. */
6406 init_recog_no_volatile ();
6408 current_function_profile
6410 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
6412 current_function_limit_stack
6413 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
6415 /* If the parameters of this function need cleaning up, get a label
6416 for the beginning of the code which executes those cleanups. This must
6417 be done before doing anything with return_label. */
6418 if (parms_have_cleanups)
6419 cleanup_label = gen_label_rtx ();
6423 /* Make the label for return statements to jump to. Do not special
6424 case machines with special return instructions -- they will be
6425 handled later during jump, ifcvt, or epilogue creation. */
6426 return_label = gen_label_rtx ();
6428 /* Initialize rtx used to return the value. */
6429 /* Do this before assign_parms so that we copy the struct value address
6430 before any library calls that assign parms might generate. */
6432 /* Decide whether to return the value in memory or in a register. */
6433 if (aggregate_value_p (DECL_RESULT (subr), subr))
6435 /* Returning something that won't go in a register. */
6436 rtx value_address = 0;
6438 #ifdef PCC_STATIC_STRUCT_RETURN
6439 if (current_function_returns_pcc_struct)
6441 int size = int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr)));
6442 value_address = assemble_static_space (size);
6447 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 1);
6448 /* Expect to be passed the address of a place to store the value.
6449 If it is passed as an argument, assign_parms will take care of
6453 value_address = gen_reg_rtx (Pmode);
6454 emit_move_insn (value_address, sv);
6459 rtx x = gen_rtx_MEM (DECL_MODE (DECL_RESULT (subr)), value_address);
6460 set_mem_attributes (x, DECL_RESULT (subr), 1);
6461 SET_DECL_RTL (DECL_RESULT (subr), x);
6464 else if (DECL_MODE (DECL_RESULT (subr)) == VOIDmode)
6465 /* If return mode is void, this decl rtl should not be used. */
6466 SET_DECL_RTL (DECL_RESULT (subr), NULL_RTX);
6469 /* Compute the return values into a pseudo reg, which we will copy
6470 into the true return register after the cleanups are done. */
6472 /* In order to figure out what mode to use for the pseudo, we
6473 figure out what the mode of the eventual return register will
6474 actually be, and use that. */
6476 = hard_function_value (TREE_TYPE (DECL_RESULT (subr)),
6479 /* Structures that are returned in registers are not aggregate_value_p,
6480 so we may see a PARALLEL or a REG. */
6481 if (REG_P (hard_reg))
6482 SET_DECL_RTL (DECL_RESULT (subr), gen_reg_rtx (GET_MODE (hard_reg)));
6483 else if (GET_CODE (hard_reg) == PARALLEL)
6484 SET_DECL_RTL (DECL_RESULT (subr), gen_group_rtx (hard_reg));
6488 /* Set DECL_REGISTER flag so that expand_function_end will copy the
6489 result to the real return register(s). */
6490 DECL_REGISTER (DECL_RESULT (subr)) = 1;
6493 /* Initialize rtx for parameters and local variables.
6494 In some cases this requires emitting insns. */
6495 assign_parms (subr);
6497 /* If function gets a static chain arg, store it. */
6498 if (cfun->static_chain_decl)
6500 tree parm = cfun->static_chain_decl;
6501 rtx local = gen_reg_rtx (Pmode);
6503 set_decl_incoming_rtl (parm, static_chain_incoming_rtx);
6504 SET_DECL_RTL (parm, local);
6505 maybe_set_unchanging (local, parm);
6506 mark_reg_pointer (local, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
6508 emit_move_insn (local, static_chain_incoming_rtx);
6511 /* If the function receives a non-local goto, then store the
6512 bits we need to restore the frame pointer. */
6513 if (cfun->nonlocal_goto_save_area)
6518 /* ??? We need to do this save early. Unfortunately here is
6519 before the frame variable gets declared. Help out... */
6520 expand_var (TREE_OPERAND (cfun->nonlocal_goto_save_area, 0));
6522 t_save = build (ARRAY_REF, ptr_type_node, cfun->nonlocal_goto_save_area,
6523 integer_zero_node, NULL_TREE, NULL_TREE);
6524 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
6526 emit_move_insn (r_save, virtual_stack_vars_rtx);
6527 update_nonlocal_goto_save_area ();
6530 /* The following was moved from init_function_start.
6531 The move is supposed to make sdb output more accurate. */
6532 /* Indicate the beginning of the function body,
6533 as opposed to parm setup. */
6534 emit_note (NOTE_INSN_FUNCTION_BEG);
6536 if (GET_CODE (get_last_insn ()) != NOTE)
6537 emit_note (NOTE_INSN_DELETED);
6538 parm_birth_insn = get_last_insn ();
6540 if (current_function_profile)
6543 PROFILE_HOOK (current_function_funcdef_no);
6547 /* After the display initializations is where the tail-recursion label
6548 should go, if we end up needing one. Ensure we have a NOTE here
6549 since some things (like trampolines) get placed before this. */
6550 tail_recursion_reentry = emit_note (NOTE_INSN_DELETED);
6552 /* Evaluate now the sizes of any types declared among the arguments. */
6553 expand_pending_sizes (nreverse (get_pending_sizes ()));
6555 /* Make sure there is a line number after the function entry setup code. */
6556 force_next_line_note ();
6559 /* Undo the effects of init_dummy_function_start. */
6561 expand_dummy_function_end (void)
6563 /* End any sequences that failed to be closed due to syntax errors. */
6564 while (in_sequence_p ())
6567 /* Outside function body, can't compute type's actual size
6568 until next function's body starts. */
6570 free_after_parsing (cfun);
6571 free_after_compilation (cfun);
6575 /* Call DOIT for each hard register used as a return value from
6576 the current function. */
6579 diddle_return_value (void (*doit) (rtx, void *), void *arg)
6581 rtx outgoing = current_function_return_rtx;
6586 if (REG_P (outgoing))
6587 (*doit) (outgoing, arg);
6588 else if (GET_CODE (outgoing) == PARALLEL)
6592 for (i = 0; i < XVECLEN (outgoing, 0); i++)
6594 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
6596 if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
6603 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
6605 emit_insn (gen_rtx_CLOBBER (VOIDmode, reg));
6609 clobber_return_register (void)
6611 diddle_return_value (do_clobber_return_reg, NULL);
6613 /* In case we do use pseudo to return value, clobber it too. */
6614 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
6616 tree decl_result = DECL_RESULT (current_function_decl);
6617 rtx decl_rtl = DECL_RTL (decl_result);
6618 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
6620 do_clobber_return_reg (decl_rtl, NULL);
6626 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
6628 emit_insn (gen_rtx_USE (VOIDmode, reg));
6632 use_return_register (void)
6634 diddle_return_value (do_use_return_reg, NULL);
6637 /* Possibly warn about unused parameters. */
6639 do_warn_unused_parameter (tree fn)
6643 for (decl = DECL_ARGUMENTS (fn);
6644 decl; decl = TREE_CHAIN (decl))
6645 if (!TREE_USED (decl) && TREE_CODE (decl) == PARM_DECL
6646 && DECL_NAME (decl) && !DECL_ARTIFICIAL (decl))
6647 warning ("%Junused parameter '%D'", decl, decl);
6650 static GTY(()) rtx initial_trampoline;
6652 /* Generate RTL for the end of the current function. */
6655 expand_function_end (void)
6659 finish_expr_for_function ();
6661 /* If arg_pointer_save_area was referenced only from a nested
6662 function, we will not have initialized it yet. Do that now. */
6663 if (arg_pointer_save_area && ! cfun->arg_pointer_save_area_init)
6664 get_arg_pointer_save_area (cfun);
6666 #ifdef NON_SAVING_SETJMP
6667 /* Don't put any variables in registers if we call setjmp
6668 on a machine that fails to restore the registers. */
6669 if (NON_SAVING_SETJMP && current_function_calls_setjmp)
6671 if (DECL_INITIAL (current_function_decl) != error_mark_node)
6672 setjmp_protect (DECL_INITIAL (current_function_decl));
6674 setjmp_protect_args ();
6678 /* If we are doing stack checking and this function makes calls,
6679 do a stack probe at the start of the function to ensure we have enough
6680 space for another stack frame. */
6681 if (flag_stack_check && ! STACK_CHECK_BUILTIN)
6685 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
6686 if (GET_CODE (insn) == CALL_INSN)
6689 probe_stack_range (STACK_CHECK_PROTECT,
6690 GEN_INT (STACK_CHECK_MAX_FRAME_SIZE));
6693 emit_insn_before (seq, tail_recursion_reentry);
6698 /* Possibly warn about unused parameters.
6699 When frontend does unit-at-a-time, the warning is already
6700 issued at finalization time. */
6701 if (warn_unused_parameter
6702 && !lang_hooks.callgraph.expand_function)
6703 do_warn_unused_parameter (current_function_decl);
6705 /* End any sequences that failed to be closed due to syntax errors. */
6706 while (in_sequence_p ())
6709 clear_pending_stack_adjust ();
6710 do_pending_stack_adjust ();
6712 /* @@@ This is a kludge. We want to ensure that instructions that
6713 may trap are not moved into the epilogue by scheduling, because
6714 we don't always emit unwind information for the epilogue.
6715 However, not all machine descriptions define a blockage insn, so
6716 emit an ASM_INPUT to act as one. */
6717 if (flag_non_call_exceptions)
6718 emit_insn (gen_rtx_ASM_INPUT (VOIDmode, ""));
6720 /* Mark the end of the function body.
6721 If control reaches this insn, the function can drop through
6722 without returning a value. */
6723 emit_note (NOTE_INSN_FUNCTION_END);
6725 /* Must mark the last line number note in the function, so that the test
6726 coverage code can avoid counting the last line twice. This just tells
6727 the code to ignore the immediately following line note, since there
6728 already exists a copy of this note somewhere above. This line number
6729 note is still needed for debugging though, so we can't delete it. */
6730 if (flag_test_coverage)
6731 emit_note (NOTE_INSN_REPEATED_LINE_NUMBER);
6733 /* Output a linenumber for the end of the function.
6734 SDB depends on this. */
6735 force_next_line_note ();
6736 emit_line_note (input_location);
6738 /* Before the return label (if any), clobber the return
6739 registers so that they are not propagated live to the rest of
6740 the function. This can only happen with functions that drop
6741 through; if there had been a return statement, there would
6742 have either been a return rtx, or a jump to the return label.
6744 We delay actual code generation after the current_function_value_rtx
6746 clobber_after = get_last_insn ();
6748 /* Output the label for the actual return from the function,
6749 if one is expected. This happens either because a function epilogue
6750 is used instead of a return instruction, or because a return was done
6751 with a goto in order to run local cleanups, or because of pcc-style
6752 structure returning. */
6754 emit_label (return_label);
6756 /* Let except.c know where it should emit the call to unregister
6757 the function context for sjlj exceptions. */
6758 if (flag_exceptions && USING_SJLJ_EXCEPTIONS)
6759 sjlj_emit_function_exit_after (get_last_insn ());
6761 /* If we had calls to alloca, and this machine needs
6762 an accurate stack pointer to exit the function,
6763 insert some code to save and restore the stack pointer. */
6764 if (! EXIT_IGNORE_STACK
6765 && current_function_calls_alloca)
6769 emit_stack_save (SAVE_FUNCTION, &tem, parm_birth_insn);
6770 emit_stack_restore (SAVE_FUNCTION, tem, NULL_RTX);
6773 /* If scalar return value was computed in a pseudo-reg, or was a named
6774 return value that got dumped to the stack, copy that to the hard
6776 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
6778 tree decl_result = DECL_RESULT (current_function_decl);
6779 rtx decl_rtl = DECL_RTL (decl_result);
6781 if (REG_P (decl_rtl)
6782 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
6783 : DECL_REGISTER (decl_result))
6785 rtx real_decl_rtl = current_function_return_rtx;
6787 /* This should be set in assign_parms. */
6788 if (! REG_FUNCTION_VALUE_P (real_decl_rtl))
6791 /* If this is a BLKmode structure being returned in registers,
6792 then use the mode computed in expand_return. Note that if
6793 decl_rtl is memory, then its mode may have been changed,
6794 but that current_function_return_rtx has not. */
6795 if (GET_MODE (real_decl_rtl) == BLKmode)
6796 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
6798 /* If a named return value dumped decl_return to memory, then
6799 we may need to re-do the PROMOTE_MODE signed/unsigned
6801 if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
6803 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
6805 if (targetm.calls.promote_function_return (TREE_TYPE (current_function_decl)))
6806 promote_mode (TREE_TYPE (decl_result), GET_MODE (decl_rtl),
6809 convert_move (real_decl_rtl, decl_rtl, unsignedp);
6811 else if (GET_CODE (real_decl_rtl) == PARALLEL)
6813 /* If expand_function_start has created a PARALLEL for decl_rtl,
6814 move the result to the real return registers. Otherwise, do
6815 a group load from decl_rtl for a named return. */
6816 if (GET_CODE (decl_rtl) == PARALLEL)
6817 emit_group_move (real_decl_rtl, decl_rtl);
6819 emit_group_load (real_decl_rtl, decl_rtl,
6820 TREE_TYPE (decl_result),
6821 int_size_in_bytes (TREE_TYPE (decl_result)));
6824 emit_move_insn (real_decl_rtl, decl_rtl);
6828 /* If returning a structure, arrange to return the address of the value
6829 in a place where debuggers expect to find it.
6831 If returning a structure PCC style,
6832 the caller also depends on this value.
6833 And current_function_returns_pcc_struct is not necessarily set. */
6834 if (current_function_returns_struct
6835 || current_function_returns_pcc_struct)
6838 = XEXP (DECL_RTL (DECL_RESULT (current_function_decl)), 0);
6839 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
6840 #ifdef FUNCTION_OUTGOING_VALUE
6842 = FUNCTION_OUTGOING_VALUE (build_pointer_type (type),
6843 current_function_decl);
6846 = FUNCTION_VALUE (build_pointer_type (type), current_function_decl);
6849 /* Mark this as a function return value so integrate will delete the
6850 assignment and USE below when inlining this function. */
6851 REG_FUNCTION_VALUE_P (outgoing) = 1;
6853 /* The address may be ptr_mode and OUTGOING may be Pmode. */
6854 value_address = convert_memory_address (GET_MODE (outgoing),
6857 emit_move_insn (outgoing, value_address);
6859 /* Show return register used to hold result (in this case the address
6861 current_function_return_rtx = outgoing;
6864 /* If this is an implementation of throw, do what's necessary to
6865 communicate between __builtin_eh_return and the epilogue. */
6866 expand_eh_return ();
6868 /* Emit the actual code to clobber return register. */
6873 clobber_return_register ();
6877 after = emit_insn_after (seq, clobber_after);
6880 /* Output the label for the naked return from the function, if one is
6881 expected. This is currently used only by __builtin_return. */
6882 if (naked_return_label)
6883 emit_label (naked_return_label);
6885 /* ??? This should no longer be necessary since stupid is no longer with
6886 us, but there are some parts of the compiler (eg reload_combine, and
6887 sh mach_dep_reorg) that still try and compute their own lifetime info
6888 instead of using the general framework. */
6889 use_return_register ();
6891 /* Fix up any gotos that jumped out to the outermost
6892 binding level of the function.
6893 Must follow emitting RETURN_LABEL. */
6895 /* If you have any cleanups to do at this point,
6896 and they need to create temporary variables,
6897 then you will lose. */
6898 expand_fixups (get_insns ());
6902 get_arg_pointer_save_area (struct function *f)
6904 rtx ret = f->x_arg_pointer_save_area;
6908 ret = assign_stack_local_1 (Pmode, GET_MODE_SIZE (Pmode), 0, f);
6909 f->x_arg_pointer_save_area = ret;
6912 if (f == cfun && ! f->arg_pointer_save_area_init)
6916 /* Save the arg pointer at the beginning of the function. The
6917 generated stack slot may not be a valid memory address, so we
6918 have to check it and fix it if necessary. */
6920 emit_move_insn (validize_mem (ret), virtual_incoming_args_rtx);
6924 push_topmost_sequence ();
6925 emit_insn_after (seq, get_insns ());
6926 pop_topmost_sequence ();
6932 /* Extend a vector that records the INSN_UIDs of INSNS
6933 (a list of one or more insns). */
6936 record_insns (rtx insns, varray_type *vecp)
6943 while (tmp != NULL_RTX)
6946 tmp = NEXT_INSN (tmp);
6949 i = VARRAY_SIZE (*vecp);
6950 VARRAY_GROW (*vecp, i + len);
6952 while (tmp != NULL_RTX)
6954 VARRAY_INT (*vecp, i) = INSN_UID (tmp);
6956 tmp = NEXT_INSN (tmp);
6960 /* Set the locator of the insn chain starting at INSN to LOC. */
6962 set_insn_locators (rtx insn, int loc)
6964 while (insn != NULL_RTX)
6967 INSN_LOCATOR (insn) = loc;
6968 insn = NEXT_INSN (insn);
6972 /* Determine how many INSN_UIDs in VEC are part of INSN. Because we can
6973 be running after reorg, SEQUENCE rtl is possible. */
6976 contains (rtx insn, varray_type vec)
6980 if (GET_CODE (insn) == INSN
6981 && GET_CODE (PATTERN (insn)) == SEQUENCE)
6984 for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
6985 for (j = VARRAY_SIZE (vec) - 1; j >= 0; --j)
6986 if (INSN_UID (XVECEXP (PATTERN (insn), 0, i)) == VARRAY_INT (vec, j))
6992 for (j = VARRAY_SIZE (vec) - 1; j >= 0; --j)
6993 if (INSN_UID (insn) == VARRAY_INT (vec, j))
7000 prologue_epilogue_contains (rtx insn)
7002 if (contains (insn, prologue))
7004 if (contains (insn, epilogue))
7010 sibcall_epilogue_contains (rtx insn)
7012 if (sibcall_epilogue)
7013 return contains (insn, sibcall_epilogue);
7018 /* Insert gen_return at the end of block BB. This also means updating
7019 block_for_insn appropriately. */
7022 emit_return_into_block (basic_block bb, rtx line_note)
7024 emit_jump_insn_after (gen_return (), BB_END (bb));
7026 emit_note_copy_after (line_note, PREV_INSN (BB_END (bb)));
7028 #endif /* HAVE_return */
7030 #if defined(HAVE_epilogue) && defined(INCOMING_RETURN_ADDR_RTX)
7032 /* These functions convert the epilogue into a variant that does not modify the
7033 stack pointer. This is used in cases where a function returns an object
7034 whose size is not known until it is computed. The called function leaves the
7035 object on the stack, leaves the stack depressed, and returns a pointer to
7038 What we need to do is track all modifications and references to the stack
7039 pointer, deleting the modifications and changing the references to point to
7040 the location the stack pointer would have pointed to had the modifications
7043 These functions need to be portable so we need to make as few assumptions
7044 about the epilogue as we can. However, the epilogue basically contains
7045 three things: instructions to reset the stack pointer, instructions to
7046 reload registers, possibly including the frame pointer, and an
7047 instruction to return to the caller.
7049 If we can't be sure of what a relevant epilogue insn is doing, we abort.
7050 We also make no attempt to validate the insns we make since if they are
7051 invalid, we probably can't do anything valid. The intent is that these
7052 routines get "smarter" as more and more machines start to use them and
7053 they try operating on different epilogues.
7055 We use the following structure to track what the part of the epilogue that
7056 we've already processed has done. We keep two copies of the SP equivalence,
7057 one for use during the insn we are processing and one for use in the next
7058 insn. The difference is because one part of a PARALLEL may adjust SP
7059 and the other may use it. */
7063 rtx sp_equiv_reg; /* REG that SP is set from, perhaps SP. */
7064 HOST_WIDE_INT sp_offset; /* Offset from SP_EQUIV_REG of present SP. */
7065 rtx new_sp_equiv_reg; /* REG to be used at end of insn. */
7066 HOST_WIDE_INT new_sp_offset; /* Offset to be used at end of insn. */
7067 rtx equiv_reg_src; /* If nonzero, the value that SP_EQUIV_REG
7068 should be set to once we no longer need
7070 rtx const_equiv[FIRST_PSEUDO_REGISTER]; /* Any known constant equivalences
7074 static void handle_epilogue_set (rtx, struct epi_info *);
7075 static void update_epilogue_consts (rtx, rtx, void *);
7076 static void emit_equiv_load (struct epi_info *);
7078 /* Modify INSN, a list of one or more insns that is part of the epilogue, to
7079 no modifications to the stack pointer. Return the new list of insns. */
7082 keep_stack_depressed (rtx insns)
7085 struct epi_info info;
7088 /* If the epilogue is just a single instruction, it must be OK as is. */
7089 if (NEXT_INSN (insns) == NULL_RTX)
7092 /* Otherwise, start a sequence, initialize the information we have, and
7093 process all the insns we were given. */
7096 info.sp_equiv_reg = stack_pointer_rtx;
7098 info.equiv_reg_src = 0;
7100 for (j = 0; j < FIRST_PSEUDO_REGISTER; j++)
7101 info.const_equiv[j] = 0;
7105 while (insn != NULL_RTX)
7107 next = NEXT_INSN (insn);
7116 /* If this insn references the register that SP is equivalent to and
7117 we have a pending load to that register, we must force out the load
7118 first and then indicate we no longer know what SP's equivalent is. */
7119 if (info.equiv_reg_src != 0
7120 && reg_referenced_p (info.sp_equiv_reg, PATTERN (insn)))
7122 emit_equiv_load (&info);
7123 info.sp_equiv_reg = 0;
7126 info.new_sp_equiv_reg = info.sp_equiv_reg;
7127 info.new_sp_offset = info.sp_offset;
7129 /* If this is a (RETURN) and the return address is on the stack,
7130 update the address and change to an indirect jump. */
7131 if (GET_CODE (PATTERN (insn)) == RETURN
7132 || (GET_CODE (PATTERN (insn)) == PARALLEL
7133 && GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == RETURN))
7135 rtx retaddr = INCOMING_RETURN_ADDR_RTX;
7137 HOST_WIDE_INT offset = 0;
7138 rtx jump_insn, jump_set;
7140 /* If the return address is in a register, we can emit the insn
7141 unchanged. Otherwise, it must be a MEM and we see what the
7142 base register and offset are. In any case, we have to emit any
7143 pending load to the equivalent reg of SP, if any. */
7144 if (REG_P (retaddr))
7146 emit_equiv_load (&info);
7151 else if (GET_CODE (retaddr) == MEM
7152 && REG_P (XEXP (retaddr, 0)))
7153 base = gen_rtx_REG (Pmode, REGNO (XEXP (retaddr, 0))), offset = 0;
7154 else if (GET_CODE (retaddr) == MEM
7155 && GET_CODE (XEXP (retaddr, 0)) == PLUS
7156 && REG_P (XEXP (XEXP (retaddr, 0), 0))
7157 && GET_CODE (XEXP (XEXP (retaddr, 0), 1)) == CONST_INT)
7159 base = gen_rtx_REG (Pmode, REGNO (XEXP (XEXP (retaddr, 0), 0)));
7160 offset = INTVAL (XEXP (XEXP (retaddr, 0), 1));
7165 /* If the base of the location containing the return pointer
7166 is SP, we must update it with the replacement address. Otherwise,
7167 just build the necessary MEM. */
7168 retaddr = plus_constant (base, offset);
7169 if (base == stack_pointer_rtx)
7170 retaddr = simplify_replace_rtx (retaddr, stack_pointer_rtx,
7171 plus_constant (info.sp_equiv_reg,
7174 retaddr = gen_rtx_MEM (Pmode, retaddr);
7176 /* If there is a pending load to the equivalent register for SP
7177 and we reference that register, we must load our address into
7178 a scratch register and then do that load. */
7179 if (info.equiv_reg_src
7180 && reg_overlap_mentioned_p (info.equiv_reg_src, retaddr))
7185 for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
7186 if (HARD_REGNO_MODE_OK (regno, Pmode)
7187 && !fixed_regs[regno]
7188 && TEST_HARD_REG_BIT (regs_invalidated_by_call, regno)
7189 && !REGNO_REG_SET_P (EXIT_BLOCK_PTR->global_live_at_start,
7191 && !refers_to_regno_p (regno,
7192 regno + hard_regno_nregs[regno]
7194 info.equiv_reg_src, NULL)
7195 && info.const_equiv[regno] == 0)
7198 if (regno == FIRST_PSEUDO_REGISTER)
7201 reg = gen_rtx_REG (Pmode, regno);
7202 emit_move_insn (reg, retaddr);
7206 emit_equiv_load (&info);
7207 jump_insn = emit_jump_insn (gen_indirect_jump (retaddr));
7209 /* Show the SET in the above insn is a RETURN. */
7210 jump_set = single_set (jump_insn);
7214 SET_IS_RETURN_P (jump_set) = 1;
7217 /* If SP is not mentioned in the pattern and its equivalent register, if
7218 any, is not modified, just emit it. Otherwise, if neither is set,
7219 replace the reference to SP and emit the insn. If none of those are
7220 true, handle each SET individually. */
7221 else if (!reg_mentioned_p (stack_pointer_rtx, PATTERN (insn))
7222 && (info.sp_equiv_reg == stack_pointer_rtx
7223 || !reg_set_p (info.sp_equiv_reg, insn)))
7225 else if (! reg_set_p (stack_pointer_rtx, insn)
7226 && (info.sp_equiv_reg == stack_pointer_rtx
7227 || !reg_set_p (info.sp_equiv_reg, insn)))
7229 if (! validate_replace_rtx (stack_pointer_rtx,
7230 plus_constant (info.sp_equiv_reg,
7237 else if (GET_CODE (PATTERN (insn)) == SET)
7238 handle_epilogue_set (PATTERN (insn), &info);
7239 else if (GET_CODE (PATTERN (insn)) == PARALLEL)
7241 for (j = 0; j < XVECLEN (PATTERN (insn), 0); j++)
7242 if (GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == SET)
7243 handle_epilogue_set (XVECEXP (PATTERN (insn), 0, j), &info);
7248 info.sp_equiv_reg = info.new_sp_equiv_reg;
7249 info.sp_offset = info.new_sp_offset;
7251 /* Now update any constants this insn sets. */
7252 note_stores (PATTERN (insn), update_epilogue_consts, &info);
7256 insns = get_insns ();
7261 /* SET is a SET from an insn in the epilogue. P is a pointer to the epi_info
7262 structure that contains information about what we've seen so far. We
7263 process this SET by either updating that data or by emitting one or
7267 handle_epilogue_set (rtx set, struct epi_info *p)
7269 /* First handle the case where we are setting SP. Record what it is being
7270 set from. If unknown, abort. */
7271 if (reg_set_p (stack_pointer_rtx, set))
7273 if (SET_DEST (set) != stack_pointer_rtx)
7276 if (GET_CODE (SET_SRC (set)) == PLUS)
7278 p->new_sp_equiv_reg = XEXP (SET_SRC (set), 0);
7279 if (GET_CODE (XEXP (SET_SRC (set), 1)) == CONST_INT)
7280 p->new_sp_offset = INTVAL (XEXP (SET_SRC (set), 1));
7281 else if (REG_P (XEXP (SET_SRC (set), 1))
7282 && REGNO (XEXP (SET_SRC (set), 1)) < FIRST_PSEUDO_REGISTER
7283 && p->const_equiv[REGNO (XEXP (SET_SRC (set), 1))] != 0)
7285 = INTVAL (p->const_equiv[REGNO (XEXP (SET_SRC (set), 1))]);
7290 p->new_sp_equiv_reg = SET_SRC (set), p->new_sp_offset = 0;
7292 /* If we are adjusting SP, we adjust from the old data. */
7293 if (p->new_sp_equiv_reg == stack_pointer_rtx)
7295 p->new_sp_equiv_reg = p->sp_equiv_reg;
7296 p->new_sp_offset += p->sp_offset;
7299 if (p->new_sp_equiv_reg == 0 || !REG_P (p->new_sp_equiv_reg))
7305 /* Next handle the case where we are setting SP's equivalent register.
7306 If we already have a value to set it to, abort. We could update, but
7307 there seems little point in handling that case. Note that we have
7308 to allow for the case where we are setting the register set in
7309 the previous part of a PARALLEL inside a single insn. But use the
7310 old offset for any updates within this insn. We must allow for the case
7311 where the register is being set in a different (usually wider) mode than
7313 else if (p->new_sp_equiv_reg != 0 && reg_set_p (p->new_sp_equiv_reg, set))
7315 if (p->equiv_reg_src != 0
7316 || !REG_P (p->new_sp_equiv_reg)
7317 || !REG_P (SET_DEST (set))
7318 || GET_MODE_BITSIZE (GET_MODE (SET_DEST (set))) > BITS_PER_WORD
7319 || REGNO (p->new_sp_equiv_reg) != REGNO (SET_DEST (set)))
7323 = simplify_replace_rtx (SET_SRC (set), stack_pointer_rtx,
7324 plus_constant (p->sp_equiv_reg,
7328 /* Otherwise, replace any references to SP in the insn to its new value
7329 and emit the insn. */
7332 SET_SRC (set) = simplify_replace_rtx (SET_SRC (set), stack_pointer_rtx,
7333 plus_constant (p->sp_equiv_reg,
7335 SET_DEST (set) = simplify_replace_rtx (SET_DEST (set), stack_pointer_rtx,
7336 plus_constant (p->sp_equiv_reg,
7342 /* Update the tracking information for registers set to constants. */
7345 update_epilogue_consts (rtx dest, rtx x, void *data)
7347 struct epi_info *p = (struct epi_info *) data;
7350 if (!REG_P (dest) || REGNO (dest) >= FIRST_PSEUDO_REGISTER)
7353 /* If we are either clobbering a register or doing a partial set,
7354 show we don't know the value. */
7355 else if (GET_CODE (x) == CLOBBER || ! rtx_equal_p (dest, SET_DEST (x)))
7356 p->const_equiv[REGNO (dest)] = 0;
7358 /* If we are setting it to a constant, record that constant. */
7359 else if (GET_CODE (SET_SRC (x)) == CONST_INT)
7360 p->const_equiv[REGNO (dest)] = SET_SRC (x);
7362 /* If this is a binary operation between a register we have been tracking
7363 and a constant, see if we can compute a new constant value. */
7364 else if (ARITHMETIC_P (SET_SRC (x))
7365 && REG_P (XEXP (SET_SRC (x), 0))
7366 && REGNO (XEXP (SET_SRC (x), 0)) < FIRST_PSEUDO_REGISTER
7367 && p->const_equiv[REGNO (XEXP (SET_SRC (x), 0))] != 0
7368 && GET_CODE (XEXP (SET_SRC (x), 1)) == CONST_INT
7369 && 0 != (new = simplify_binary_operation
7370 (GET_CODE (SET_SRC (x)), GET_MODE (dest),
7371 p->const_equiv[REGNO (XEXP (SET_SRC (x), 0))],
7372 XEXP (SET_SRC (x), 1)))
7373 && GET_CODE (new) == CONST_INT)
7374 p->const_equiv[REGNO (dest)] = new;
7376 /* Otherwise, we can't do anything with this value. */
7378 p->const_equiv[REGNO (dest)] = 0;
7381 /* Emit an insn to do the load shown in p->equiv_reg_src, if needed. */
7384 emit_equiv_load (struct epi_info *p)
7386 if (p->equiv_reg_src != 0)
7388 rtx dest = p->sp_equiv_reg;
7390 if (GET_MODE (p->equiv_reg_src) != GET_MODE (dest))
7391 dest = gen_rtx_REG (GET_MODE (p->equiv_reg_src),
7392 REGNO (p->sp_equiv_reg));
7394 emit_move_insn (dest, p->equiv_reg_src);
7395 p->equiv_reg_src = 0;
7400 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
7401 this into place with notes indicating where the prologue ends and where
7402 the epilogue begins. Update the basic block information when possible. */
7405 thread_prologue_and_epilogue_insns (rtx f ATTRIBUTE_UNUSED)
7409 #if defined (HAVE_sibcall_epilogue) || defined (HAVE_epilogue) || defined (HAVE_return) || defined (HAVE_prologue)
7412 #ifdef HAVE_prologue
7413 rtx prologue_end = NULL_RTX;
7415 #if defined (HAVE_epilogue) || defined(HAVE_return)
7416 rtx epilogue_end = NULL_RTX;
7419 #ifdef HAVE_prologue
7423 seq = gen_prologue ();
7426 /* Retain a map of the prologue insns. */
7427 record_insns (seq, &prologue);
7428 prologue_end = emit_note (NOTE_INSN_PROLOGUE_END);
7432 set_insn_locators (seq, prologue_locator);
7434 /* Can't deal with multiple successors of the entry block
7435 at the moment. Function should always have at least one
7437 if (!ENTRY_BLOCK_PTR->succ || ENTRY_BLOCK_PTR->succ->succ_next)
7440 insert_insn_on_edge (seq, ENTRY_BLOCK_PTR->succ);
7445 /* If the exit block has no non-fake predecessors, we don't need
7447 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7448 if ((e->flags & EDGE_FAKE) == 0)
7454 if (optimize && HAVE_return)
7456 /* If we're allowed to generate a simple return instruction,
7457 then by definition we don't need a full epilogue. Examine
7458 the block that falls through to EXIT. If it does not
7459 contain any code, examine its predecessors and try to
7460 emit (conditional) return instructions. */
7466 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7467 if (e->flags & EDGE_FALLTHRU)
7473 /* Verify that there are no active instructions in the last block. */
7474 label = BB_END (last);
7475 while (label && GET_CODE (label) != CODE_LABEL)
7477 if (active_insn_p (label))
7479 label = PREV_INSN (label);
7482 if (BB_HEAD (last) == label && GET_CODE (label) == CODE_LABEL)
7484 rtx epilogue_line_note = NULL_RTX;
7486 /* Locate the line number associated with the closing brace,
7487 if we can find one. */
7488 for (seq = get_last_insn ();
7489 seq && ! active_insn_p (seq);
7490 seq = PREV_INSN (seq))
7491 if (GET_CODE (seq) == NOTE && NOTE_LINE_NUMBER (seq) > 0)
7493 epilogue_line_note = seq;
7497 for (e = last->pred; e; e = e_next)
7499 basic_block bb = e->src;
7502 e_next = e->pred_next;
7503 if (bb == ENTRY_BLOCK_PTR)
7507 if ((GET_CODE (jump) != JUMP_INSN) || JUMP_LABEL (jump) != label)
7510 /* If we have an unconditional jump, we can replace that
7511 with a simple return instruction. */
7512 if (simplejump_p (jump))
7514 emit_return_into_block (bb, epilogue_line_note);
7518 /* If we have a conditional jump, we can try to replace
7519 that with a conditional return instruction. */
7520 else if (condjump_p (jump))
7522 if (! redirect_jump (jump, 0, 0))
7525 /* If this block has only one successor, it both jumps
7526 and falls through to the fallthru block, so we can't
7528 if (bb->succ->succ_next == NULL)
7534 /* Fix up the CFG for the successful change we just made. */
7535 redirect_edge_succ (e, EXIT_BLOCK_PTR);
7538 /* Emit a return insn for the exit fallthru block. Whether
7539 this is still reachable will be determined later. */
7541 emit_barrier_after (BB_END (last));
7542 emit_return_into_block (last, epilogue_line_note);
7543 epilogue_end = BB_END (last);
7544 last->succ->flags &= ~EDGE_FALLTHRU;
7549 /* Find the edge that falls through to EXIT. Other edges may exist
7550 due to RETURN instructions, but those don't need epilogues.
7551 There really shouldn't be a mixture -- either all should have
7552 been converted or none, however... */
7554 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7555 if (e->flags & EDGE_FALLTHRU)
7560 #ifdef HAVE_epilogue
7564 epilogue_end = emit_note (NOTE_INSN_EPILOGUE_BEG);
7566 seq = gen_epilogue ();
7568 #ifdef INCOMING_RETURN_ADDR_RTX
7569 /* If this function returns with the stack depressed and we can support
7570 it, massage the epilogue to actually do that. */
7571 if (TREE_CODE (TREE_TYPE (current_function_decl)) == FUNCTION_TYPE
7572 && TYPE_RETURNS_STACK_DEPRESSED (TREE_TYPE (current_function_decl)))
7573 seq = keep_stack_depressed (seq);
7576 emit_jump_insn (seq);
7578 /* Retain a map of the epilogue insns. */
7579 record_insns (seq, &epilogue);
7580 set_insn_locators (seq, epilogue_locator);
7585 insert_insn_on_edge (seq, e);
7593 if (! next_active_insn (BB_END (e->src)))
7595 /* We have a fall-through edge to the exit block, the source is not
7596 at the end of the function, and there will be an assembler epilogue
7597 at the end of the function.
7598 We can't use force_nonfallthru here, because that would try to
7599 use return. Inserting a jump 'by hand' is extremely messy, so
7600 we take advantage of cfg_layout_finalize using
7601 fixup_fallthru_exit_predecessor. */
7602 cfg_layout_initialize ();
7603 FOR_EACH_BB (cur_bb)
7604 if (cur_bb->index >= 0 && cur_bb->next_bb->index >= 0)
7605 cur_bb->rbi->next = cur_bb->next_bb;
7606 cfg_layout_finalize ();
7611 commit_edge_insertions ();
7613 #ifdef HAVE_sibcall_epilogue
7614 /* Emit sibling epilogues before any sibling call sites. */
7615 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7617 basic_block bb = e->src;
7618 rtx insn = BB_END (bb);
7622 if (GET_CODE (insn) != CALL_INSN
7623 || ! SIBLING_CALL_P (insn))
7627 emit_insn (gen_sibcall_epilogue ());
7631 /* Retain a map of the epilogue insns. Used in life analysis to
7632 avoid getting rid of sibcall epilogue insns. Do this before we
7633 actually emit the sequence. */
7634 record_insns (seq, &sibcall_epilogue);
7635 set_insn_locators (seq, epilogue_locator);
7637 i = PREV_INSN (insn);
7638 newinsn = emit_insn_before (seq, insn);
7642 #ifdef HAVE_prologue
7643 /* This is probably all useless now that we use locators. */
7648 /* GDB handles `break f' by setting a breakpoint on the first
7649 line note after the prologue. Which means (1) that if
7650 there are line number notes before where we inserted the
7651 prologue we should move them, and (2) we should generate a
7652 note before the end of the first basic block, if there isn't
7655 ??? This behavior is completely broken when dealing with
7656 multiple entry functions. We simply place the note always
7657 into first basic block and let alternate entry points
7661 for (insn = prologue_end; insn; insn = prev)
7663 prev = PREV_INSN (insn);
7664 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
7666 /* Note that we cannot reorder the first insn in the
7667 chain, since rest_of_compilation relies on that
7668 remaining constant. */
7671 reorder_insns (insn, insn, prologue_end);
7675 /* Find the last line number note in the first block. */
7676 for (insn = BB_END (ENTRY_BLOCK_PTR->next_bb);
7677 insn != prologue_end && insn;
7678 insn = PREV_INSN (insn))
7679 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
7682 /* If we didn't find one, make a copy of the first line number
7686 for (insn = next_active_insn (prologue_end);
7688 insn = PREV_INSN (insn))
7689 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
7691 emit_note_copy_after (insn, prologue_end);
7697 #ifdef HAVE_epilogue
7702 /* Similarly, move any line notes that appear after the epilogue.
7703 There is no need, however, to be quite so anal about the existence
7704 of such a note. Also move the NOTE_INSN_FUNCTION_END and (possibly)
7705 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
7707 for (insn = epilogue_end; insn; insn = next)
7709 next = NEXT_INSN (insn);
7710 if (GET_CODE (insn) == NOTE
7711 && (NOTE_LINE_NUMBER (insn) > 0
7712 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_BEG
7713 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_END))
7714 reorder_insns (insn, insn, PREV_INSN (epilogue_end));
7720 /* Reposition the prologue-end and epilogue-begin notes after instruction
7721 scheduling and delayed branch scheduling. */
7724 reposition_prologue_and_epilogue_notes (rtx f ATTRIBUTE_UNUSED)
7726 #if defined (HAVE_prologue) || defined (HAVE_epilogue)
7727 rtx insn, last, note;
7730 if ((len = VARRAY_SIZE (prologue)) > 0)
7734 /* Scan from the beginning until we reach the last prologue insn.
7735 We apparently can't depend on basic_block_{head,end} after
7737 for (insn = f; insn; insn = NEXT_INSN (insn))
7739 if (GET_CODE (insn) == NOTE)
7741 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_PROLOGUE_END)
7744 else if (contains (insn, prologue))
7754 /* Find the prologue-end note if we haven't already, and
7755 move it to just after the last prologue insn. */
7758 for (note = last; (note = NEXT_INSN (note));)
7759 if (GET_CODE (note) == NOTE
7760 && NOTE_LINE_NUMBER (note) == NOTE_INSN_PROLOGUE_END)
7764 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
7765 if (GET_CODE (last) == CODE_LABEL)
7766 last = NEXT_INSN (last);
7767 reorder_insns (note, note, last);
7771 if ((len = VARRAY_SIZE (epilogue)) > 0)
7775 /* Scan from the end until we reach the first epilogue insn.
7776 We apparently can't depend on basic_block_{head,end} after
7778 for (insn = get_last_insn (); insn; insn = PREV_INSN (insn))
7780 if (GET_CODE (insn) == NOTE)
7782 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EPILOGUE_BEG)
7785 else if (contains (insn, epilogue))
7795 /* Find the epilogue-begin note if we haven't already, and
7796 move it to just before the first epilogue insn. */
7799 for (note = insn; (note = PREV_INSN (note));)
7800 if (GET_CODE (note) == NOTE
7801 && NOTE_LINE_NUMBER (note) == NOTE_INSN_EPILOGUE_BEG)
7805 if (PREV_INSN (last) != note)
7806 reorder_insns (note, note, PREV_INSN (last));
7809 #endif /* HAVE_prologue or HAVE_epilogue */
7812 /* Called once, at initialization, to initialize function.c. */
7815 init_function_once (void)
7817 VARRAY_INT_INIT (prologue, 0, "prologue");
7818 VARRAY_INT_INIT (epilogue, 0, "epilogue");
7819 VARRAY_INT_INIT (sibcall_epilogue, 0, "sibcall_epilogue");
7822 /* Resets insn_block_boundaries array. */
7825 reset_block_changes (void)
7827 VARRAY_TREE_INIT (cfun->ib_boundaries_block, 100, "ib_boundaries_block");
7828 VARRAY_PUSH_TREE (cfun->ib_boundaries_block, NULL_TREE);
7831 /* Record the boundary for BLOCK. */
7833 record_block_change (tree block)
7841 last_block = VARRAY_TOP_TREE (cfun->ib_boundaries_block);
7842 VARRAY_POP (cfun->ib_boundaries_block);
7844 for (i = VARRAY_ACTIVE_SIZE (cfun->ib_boundaries_block); i < n; i++)
7845 VARRAY_PUSH_TREE (cfun->ib_boundaries_block, last_block);
7847 VARRAY_PUSH_TREE (cfun->ib_boundaries_block, block);
7850 /* Finishes record of boundaries. */
7851 void finalize_block_changes (void)
7853 record_block_change (DECL_INITIAL (current_function_decl));
7856 /* For INSN return the BLOCK it belongs to. */
7858 check_block_change (rtx insn, tree *block)
7860 unsigned uid = INSN_UID (insn);
7862 if (uid >= VARRAY_ACTIVE_SIZE (cfun->ib_boundaries_block))
7865 *block = VARRAY_TREE (cfun->ib_boundaries_block, uid);
7868 /* Releases the ib_boundaries_block records. */
7870 free_block_changes (void)
7872 cfun->ib_boundaries_block = NULL;
7875 /* Returns the name of the current function. */
7877 current_function_name (void)
7879 return lang_hooks.decl_printable_name (cfun->decl, 2);
7882 #include "gt-function.h"