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;
1772 if (SMALL_REGISTER_CLASSES)
1774 /* If the insn that copies the results of a CALL_INSN
1775 into a pseudo now references VAR, we have to use an
1776 intermediate pseudo since we want the life of the
1777 return value register to be only a single insn.
1779 If we don't use an intermediate pseudo, such things as
1780 address computations to make the address of VAR valid
1781 if it is not can be placed between the CALL_INSN and INSN.
1783 To make sure this doesn't happen, we record the destination
1784 of the CALL_INSN and see if the next insn uses both that
1787 if (call_dest != 0 && GET_CODE (insn) == INSN
1788 && reg_mentioned_p (var, PATTERN (insn))
1789 && reg_mentioned_p (call_dest, PATTERN (insn)))
1791 rtx temp = gen_reg_rtx (GET_MODE (call_dest));
1793 emit_insn_before (gen_move_insn (temp, call_dest), insn);
1795 PATTERN (insn) = replace_rtx (PATTERN (insn),
1799 if (GET_CODE (insn) == CALL_INSN
1800 && GET_CODE (PATTERN (insn)) == SET)
1801 call_dest = SET_DEST (PATTERN (insn));
1802 else if (GET_CODE (insn) == CALL_INSN
1803 && GET_CODE (PATTERN (insn)) == PARALLEL
1804 && GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == SET)
1805 call_dest = SET_DEST (XVECEXP (PATTERN (insn), 0, 0));
1810 /* See if we have to do anything to INSN now that VAR is in
1811 memory. If it needs to be loaded into a pseudo, use a single
1812 pseudo for the entire insn in case there is a MATCH_DUP
1813 between two operands. We pass a pointer to the head of
1814 a list of struct fixup_replacements. If fixup_var_refs_1
1815 needs to allocate pseudos or replacement MEMs (for SUBREGs),
1816 it will record them in this list.
1818 If it allocated a pseudo for any replacement, we copy into
1821 fixup_var_refs_1 (var, promoted_mode, &PATTERN (insn), insn,
1822 &replacements, no_share);
1824 while (replacements)
1826 struct fixup_replacement *next;
1828 if (REG_P (replacements->new))
1833 /* OLD might be a (subreg (mem)). */
1834 if (GET_CODE (replacements->old) == SUBREG)
1836 = fixup_memory_subreg (replacements->old, insn,
1840 = fixup_stack_1 (replacements->old, insn);
1842 insert_before = insn;
1844 /* If we are changing the mode, do a conversion.
1845 This might be wasteful, but combine.c will
1846 eliminate much of the waste. */
1848 if (GET_MODE (replacements->new)
1849 != GET_MODE (replacements->old))
1852 convert_move (replacements->new,
1853 replacements->old, unsignedp);
1858 seq = gen_move_insn (replacements->new,
1861 emit_insn_before (seq, insert_before);
1864 next = replacements->next;
1865 free (replacements);
1866 replacements = next;
1870 /* Also fix up any invalid exprs in the REG_NOTES of this insn.
1871 But don't touch other insns referred to by reg-notes;
1872 we will get them elsewhere. */
1875 if (GET_CODE (note) != INSN_LIST)
1877 = walk_fixup_memory_subreg (XEXP (note, 0), insn, var,
1879 note = XEXP (note, 1);
1883 /* VAR is a MEM that used to be a pseudo register with mode PROMOTED_MODE.
1884 See if the rtx expression at *LOC in INSN needs to be changed.
1886 REPLACEMENTS is a pointer to a list head that starts out zero, but may
1887 contain a list of original rtx's and replacements. If we find that we need
1888 to modify this insn by replacing a memory reference with a pseudo or by
1889 making a new MEM to implement a SUBREG, we consult that list to see if
1890 we have already chosen a replacement. If none has already been allocated,
1891 we allocate it and update the list. fixup_var_refs_insn will copy VAR
1892 or the SUBREG, as appropriate, to the pseudo. */
1895 fixup_var_refs_1 (rtx var, enum machine_mode promoted_mode, rtx *loc, rtx insn,
1896 struct fixup_replacement **replacements, rtx no_share)
1900 RTX_CODE code = GET_CODE (x);
1903 struct fixup_replacement *replacement;
1908 if (XEXP (x, 0) == var)
1910 /* Prevent sharing of rtl that might lose. */
1911 rtx sub = copy_rtx (XEXP (var, 0));
1913 if (! validate_change (insn, loc, sub, 0))
1915 rtx y = gen_reg_rtx (GET_MODE (sub));
1918 /* We should be able to replace with a register or all is lost.
1919 Note that we can't use validate_change to verify this, since
1920 we're not caring for replacing all dups simultaneously. */
1921 if (! validate_replace_rtx (*loc, y, insn))
1924 /* Careful! First try to recognize a direct move of the
1925 value, mimicking how things are done in gen_reload wrt
1926 PLUS. Consider what happens when insn is a conditional
1927 move instruction and addsi3 clobbers flags. */
1930 new_insn = emit_insn (gen_rtx_SET (VOIDmode, y, sub));
1934 if (recog_memoized (new_insn) < 0)
1936 /* That failed. Fall back on force_operand and hope. */
1939 sub = force_operand (sub, y);
1941 emit_insn (gen_move_insn (y, sub));
1947 /* Don't separate setter from user. */
1948 if (PREV_INSN (insn) && sets_cc0_p (PREV_INSN (insn)))
1949 insn = PREV_INSN (insn);
1952 emit_insn_before (seq, insn);
1960 /* If we already have a replacement, use it. Otherwise,
1961 try to fix up this address in case it is invalid. */
1963 replacement = find_fixup_replacement (replacements, var);
1964 if (replacement->new)
1966 *loc = replacement->new;
1970 *loc = replacement->new = x = fixup_stack_1 (x, insn);
1972 /* Unless we are forcing memory to register or we changed the mode,
1973 we can leave things the way they are if the insn is valid. */
1975 INSN_CODE (insn) = -1;
1976 if (! flag_force_mem && GET_MODE (x) == promoted_mode
1977 && recog_memoized (insn) >= 0)
1980 *loc = replacement->new = gen_reg_rtx (promoted_mode);
1984 /* If X contains VAR, we need to unshare it here so that we update
1985 each occurrence separately. But all identical MEMs in one insn
1986 must be replaced with the same rtx because of the possibility of
1989 if (reg_mentioned_p (var, x))
1991 replacement = find_fixup_replacement (replacements, x);
1992 if (replacement->new == 0)
1993 replacement->new = copy_most_rtx (x, no_share);
1995 *loc = x = replacement->new;
1996 code = GET_CODE (x);
2013 /* Note that in some cases those types of expressions are altered
2014 by optimize_bit_field, and do not survive to get here. */
2015 if (XEXP (x, 0) == var
2016 || (GET_CODE (XEXP (x, 0)) == SUBREG
2017 && SUBREG_REG (XEXP (x, 0)) == var))
2019 /* Get TEM as a valid MEM in the mode presently in the insn.
2021 We don't worry about the possibility of MATCH_DUP here; it
2022 is highly unlikely and would be tricky to handle. */
2025 if (GET_CODE (tem) == SUBREG)
2027 if (GET_MODE_BITSIZE (GET_MODE (tem))
2028 > GET_MODE_BITSIZE (GET_MODE (var)))
2030 replacement = find_fixup_replacement (replacements, var);
2031 if (replacement->new == 0)
2032 replacement->new = gen_reg_rtx (GET_MODE (var));
2033 SUBREG_REG (tem) = replacement->new;
2035 /* The following code works only if we have a MEM, so we
2036 need to handle the subreg here. We directly substitute
2037 it assuming that a subreg must be OK here. We already
2038 scheduled a replacement to copy the mem into the
2044 tem = fixup_memory_subreg (tem, insn, promoted_mode, 0);
2047 tem = fixup_stack_1 (tem, insn);
2049 /* Unless we want to load from memory, get TEM into the proper mode
2050 for an extract from memory. This can only be done if the
2051 extract is at a constant position and length. */
2053 if (! flag_force_mem && GET_CODE (XEXP (x, 1)) == CONST_INT
2054 && GET_CODE (XEXP (x, 2)) == CONST_INT
2055 && ! mode_dependent_address_p (XEXP (tem, 0))
2056 && ! MEM_VOLATILE_P (tem))
2058 enum machine_mode wanted_mode = VOIDmode;
2059 enum machine_mode is_mode = GET_MODE (tem);
2060 HOST_WIDE_INT pos = INTVAL (XEXP (x, 2));
2062 if (GET_CODE (x) == ZERO_EXTRACT)
2064 enum machine_mode new_mode
2065 = mode_for_extraction (EP_extzv, 1);
2066 if (new_mode != MAX_MACHINE_MODE)
2067 wanted_mode = new_mode;
2069 else if (GET_CODE (x) == SIGN_EXTRACT)
2071 enum machine_mode new_mode
2072 = mode_for_extraction (EP_extv, 1);
2073 if (new_mode != MAX_MACHINE_MODE)
2074 wanted_mode = new_mode;
2077 /* If we have a narrower mode, we can do something. */
2078 if (wanted_mode != VOIDmode
2079 && GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
2081 HOST_WIDE_INT offset = pos / BITS_PER_UNIT;
2082 rtx old_pos = XEXP (x, 2);
2085 /* If the bytes and bits are counted differently, we
2086 must adjust the offset. */
2087 if (BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN)
2088 offset = (GET_MODE_SIZE (is_mode)
2089 - GET_MODE_SIZE (wanted_mode) - offset);
2091 pos %= GET_MODE_BITSIZE (wanted_mode);
2093 newmem = adjust_address_nv (tem, wanted_mode, offset);
2095 /* Make the change and see if the insn remains valid. */
2096 INSN_CODE (insn) = -1;
2097 XEXP (x, 0) = newmem;
2098 XEXP (x, 2) = GEN_INT (pos);
2100 if (recog_memoized (insn) >= 0)
2103 /* Otherwise, restore old position. XEXP (x, 0) will be
2105 XEXP (x, 2) = old_pos;
2109 /* If we get here, the bitfield extract insn can't accept a memory
2110 reference. Copy the input into a register. */
2112 tem1 = gen_reg_rtx (GET_MODE (tem));
2113 emit_insn_before (gen_move_insn (tem1, tem), insn);
2120 if (SUBREG_REG (x) == var)
2122 /* If this is a special SUBREG made because VAR was promoted
2123 from a wider mode, replace it with VAR and call ourself
2124 recursively, this time saying that the object previously
2125 had its current mode (by virtue of the SUBREG). */
2127 if (SUBREG_PROMOTED_VAR_P (x))
2130 fixup_var_refs_1 (var, GET_MODE (var), loc, insn, replacements,
2135 /* If this SUBREG makes VAR wider, it has become a paradoxical
2136 SUBREG with VAR in memory, but these aren't allowed at this
2137 stage of the compilation. So load VAR into a pseudo and take
2138 a SUBREG of that pseudo. */
2139 if (GET_MODE_SIZE (GET_MODE (x)) > GET_MODE_SIZE (GET_MODE (var)))
2141 replacement = find_fixup_replacement (replacements, var);
2142 if (replacement->new == 0)
2143 replacement->new = gen_reg_rtx (promoted_mode);
2144 SUBREG_REG (x) = replacement->new;
2148 /* See if we have already found a replacement for this SUBREG.
2149 If so, use it. Otherwise, make a MEM and see if the insn
2150 is recognized. If not, or if we should force MEM into a register,
2151 make a pseudo for this SUBREG. */
2152 replacement = find_fixup_replacement (replacements, x);
2153 if (replacement->new)
2155 enum machine_mode mode = GET_MODE (x);
2156 *loc = replacement->new;
2158 /* Careful! We may have just replaced a SUBREG by a MEM, which
2159 means that the insn may have become invalid again. We can't
2160 in this case make a new replacement since we already have one
2161 and we must deal with MATCH_DUPs. */
2162 if (GET_CODE (replacement->new) == MEM)
2164 INSN_CODE (insn) = -1;
2165 if (recog_memoized (insn) >= 0)
2168 fixup_var_refs_1 (replacement->new, mode, &PATTERN (insn),
2169 insn, replacements, no_share);
2175 replacement->new = *loc = fixup_memory_subreg (x, insn,
2178 INSN_CODE (insn) = -1;
2179 if (! flag_force_mem && recog_memoized (insn) >= 0)
2182 *loc = replacement->new = gen_reg_rtx (GET_MODE (x));
2188 /* First do special simplification of bit-field references. */
2189 if (GET_CODE (SET_DEST (x)) == SIGN_EXTRACT
2190 || GET_CODE (SET_DEST (x)) == ZERO_EXTRACT)
2191 optimize_bit_field (x, insn, 0);
2192 if (GET_CODE (SET_SRC (x)) == SIGN_EXTRACT
2193 || GET_CODE (SET_SRC (x)) == ZERO_EXTRACT)
2194 optimize_bit_field (x, insn, 0);
2196 /* For a paradoxical SUBREG inside a ZERO_EXTRACT, load the object
2197 into a register and then store it back out. */
2198 if (GET_CODE (SET_DEST (x)) == ZERO_EXTRACT
2199 && GET_CODE (XEXP (SET_DEST (x), 0)) == SUBREG
2200 && SUBREG_REG (XEXP (SET_DEST (x), 0)) == var
2201 && (GET_MODE_SIZE (GET_MODE (XEXP (SET_DEST (x), 0)))
2202 > GET_MODE_SIZE (GET_MODE (var))))
2204 replacement = find_fixup_replacement (replacements, var);
2205 if (replacement->new == 0)
2206 replacement->new = gen_reg_rtx (GET_MODE (var));
2208 SUBREG_REG (XEXP (SET_DEST (x), 0)) = replacement->new;
2209 emit_insn_after (gen_move_insn (var, replacement->new), insn);
2212 /* If SET_DEST is now a paradoxical SUBREG, put the result of this
2213 insn into a pseudo and store the low part of the pseudo into VAR. */
2214 if (GET_CODE (SET_DEST (x)) == SUBREG
2215 && SUBREG_REG (SET_DEST (x)) == var
2216 && (GET_MODE_SIZE (GET_MODE (SET_DEST (x)))
2217 > GET_MODE_SIZE (GET_MODE (var))))
2219 SET_DEST (x) = tem = gen_reg_rtx (GET_MODE (SET_DEST (x)));
2220 emit_insn_after (gen_move_insn (var, gen_lowpart (GET_MODE (var),
2227 rtx dest = SET_DEST (x);
2228 rtx src = SET_SRC (x);
2229 rtx outerdest = dest;
2231 while (GET_CODE (dest) == SUBREG || GET_CODE (dest) == STRICT_LOW_PART
2232 || GET_CODE (dest) == SIGN_EXTRACT
2233 || GET_CODE (dest) == ZERO_EXTRACT)
2234 dest = XEXP (dest, 0);
2236 if (GET_CODE (src) == SUBREG)
2237 src = SUBREG_REG (src);
2239 /* If VAR does not appear at the top level of the SET
2240 just scan the lower levels of the tree. */
2242 if (src != var && dest != var)
2245 /* We will need to rerecognize this insn. */
2246 INSN_CODE (insn) = -1;
2248 if (GET_CODE (outerdest) == ZERO_EXTRACT && dest == var
2249 && mode_for_extraction (EP_insv, -1) != MAX_MACHINE_MODE)
2251 /* Since this case will return, ensure we fixup all the
2253 fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 1),
2254 insn, replacements, no_share);
2255 fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 2),
2256 insn, replacements, no_share);
2257 fixup_var_refs_1 (var, promoted_mode, &SET_SRC (x),
2258 insn, replacements, no_share);
2260 tem = XEXP (outerdest, 0);
2262 /* Clean up (SUBREG:SI (MEM:mode ...) 0)
2263 that may appear inside a ZERO_EXTRACT.
2264 This was legitimate when the MEM was a REG. */
2265 if (GET_CODE (tem) == SUBREG
2266 && SUBREG_REG (tem) == var)
2267 tem = fixup_memory_subreg (tem, insn, promoted_mode, 0);
2269 tem = fixup_stack_1 (tem, insn);
2271 if (GET_CODE (XEXP (outerdest, 1)) == CONST_INT
2272 && GET_CODE (XEXP (outerdest, 2)) == CONST_INT
2273 && ! mode_dependent_address_p (XEXP (tem, 0))
2274 && ! MEM_VOLATILE_P (tem))
2276 enum machine_mode wanted_mode;
2277 enum machine_mode is_mode = GET_MODE (tem);
2278 HOST_WIDE_INT pos = INTVAL (XEXP (outerdest, 2));
2280 wanted_mode = mode_for_extraction (EP_insv, 0);
2282 /* If we have a narrower mode, we can do something. */
2283 if (GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
2285 HOST_WIDE_INT offset = pos / BITS_PER_UNIT;
2286 rtx old_pos = XEXP (outerdest, 2);
2289 if (BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN)
2290 offset = (GET_MODE_SIZE (is_mode)
2291 - GET_MODE_SIZE (wanted_mode) - offset);
2293 pos %= GET_MODE_BITSIZE (wanted_mode);
2295 newmem = adjust_address_nv (tem, wanted_mode, offset);
2297 /* Make the change and see if the insn remains valid. */
2298 INSN_CODE (insn) = -1;
2299 XEXP (outerdest, 0) = newmem;
2300 XEXP (outerdest, 2) = GEN_INT (pos);
2302 if (recog_memoized (insn) >= 0)
2305 /* Otherwise, restore old position. XEXP (x, 0) will be
2307 XEXP (outerdest, 2) = old_pos;
2311 /* If we get here, the bit-field store doesn't allow memory
2312 or isn't located at a constant position. Load the value into
2313 a register, do the store, and put it back into memory. */
2315 tem1 = gen_reg_rtx (GET_MODE (tem));
2316 emit_insn_before (gen_move_insn (tem1, tem), insn);
2317 emit_insn_after (gen_move_insn (tem, tem1), insn);
2318 XEXP (outerdest, 0) = tem1;
2322 /* STRICT_LOW_PART is a no-op on memory references
2323 and it can cause combinations to be unrecognizable,
2326 if (dest == var && GET_CODE (SET_DEST (x)) == STRICT_LOW_PART)
2327 SET_DEST (x) = XEXP (SET_DEST (x), 0);
2329 /* A valid insn to copy VAR into or out of a register
2330 must be left alone, to avoid an infinite loop here.
2331 If the reference to VAR is by a subreg, fix that up,
2332 since SUBREG is not valid for a memref.
2333 Also fix up the address of the stack slot.
2335 Note that we must not try to recognize the insn until
2336 after we know that we have valid addresses and no
2337 (subreg (mem ...) ...) constructs, since these interfere
2338 with determining the validity of the insn. */
2340 if ((SET_SRC (x) == var
2341 || (GET_CODE (SET_SRC (x)) == SUBREG
2342 && SUBREG_REG (SET_SRC (x)) == var))
2343 && (REG_P (SET_DEST (x))
2344 || (GET_CODE (SET_DEST (x)) == SUBREG
2345 && REG_P (SUBREG_REG (SET_DEST (x)))))
2346 && GET_MODE (var) == promoted_mode
2347 && x == single_set (insn))
2351 if (GET_CODE (SET_SRC (x)) == SUBREG
2352 && (GET_MODE_SIZE (GET_MODE (SET_SRC (x)))
2353 > GET_MODE_SIZE (GET_MODE (var))))
2355 /* This (subreg VAR) is now a paradoxical subreg. We need
2356 to replace VAR instead of the subreg. */
2357 replacement = find_fixup_replacement (replacements, var);
2358 if (replacement->new == NULL_RTX)
2359 replacement->new = gen_reg_rtx (GET_MODE (var));
2360 SUBREG_REG (SET_SRC (x)) = replacement->new;
2364 replacement = find_fixup_replacement (replacements, SET_SRC (x));
2365 if (replacement->new)
2366 SET_SRC (x) = replacement->new;
2367 else if (GET_CODE (SET_SRC (x)) == SUBREG)
2368 SET_SRC (x) = replacement->new
2369 = fixup_memory_subreg (SET_SRC (x), insn, promoted_mode,
2372 SET_SRC (x) = replacement->new
2373 = fixup_stack_1 (SET_SRC (x), insn);
2376 if (recog_memoized (insn) >= 0)
2379 /* INSN is not valid, but we know that we want to
2380 copy SET_SRC (x) to SET_DEST (x) in some way. So
2381 we generate the move and see whether it requires more
2382 than one insn. If it does, we emit those insns and
2383 delete INSN. Otherwise, we can just replace the pattern
2384 of INSN; we have already verified above that INSN has
2385 no other function that to do X. */
2387 pat = gen_move_insn (SET_DEST (x), SET_SRC (x));
2388 if (NEXT_INSN (pat) != NULL_RTX)
2390 last = emit_insn_before (pat, insn);
2392 /* INSN might have REG_RETVAL or other important notes, so
2393 we need to store the pattern of the last insn in the
2394 sequence into INSN similarly to the normal case. LAST
2395 should not have REG_NOTES, but we allow them if INSN has
2397 if (REG_NOTES (last) && REG_NOTES (insn))
2399 if (REG_NOTES (last))
2400 REG_NOTES (insn) = REG_NOTES (last);
2401 PATTERN (insn) = PATTERN (last);
2406 PATTERN (insn) = PATTERN (pat);
2411 if ((SET_DEST (x) == var
2412 || (GET_CODE (SET_DEST (x)) == SUBREG
2413 && SUBREG_REG (SET_DEST (x)) == var))
2414 && (REG_P (SET_SRC (x))
2415 || (GET_CODE (SET_SRC (x)) == SUBREG
2416 && REG_P (SUBREG_REG (SET_SRC (x)))))
2417 && GET_MODE (var) == promoted_mode
2418 && x == single_set (insn))
2422 if (GET_CODE (SET_DEST (x)) == SUBREG)
2423 SET_DEST (x) = fixup_memory_subreg (SET_DEST (x), insn,
2426 SET_DEST (x) = fixup_stack_1 (SET_DEST (x), insn);
2428 if (recog_memoized (insn) >= 0)
2431 pat = gen_move_insn (SET_DEST (x), SET_SRC (x));
2432 if (NEXT_INSN (pat) != NULL_RTX)
2434 last = emit_insn_before (pat, insn);
2436 /* INSN might have REG_RETVAL or other important notes, so
2437 we need to store the pattern of the last insn in the
2438 sequence into INSN similarly to the normal case. LAST
2439 should not have REG_NOTES, but we allow them if INSN has
2441 if (REG_NOTES (last) && REG_NOTES (insn))
2443 if (REG_NOTES (last))
2444 REG_NOTES (insn) = REG_NOTES (last);
2445 PATTERN (insn) = PATTERN (last);
2450 PATTERN (insn) = PATTERN (pat);
2455 /* Otherwise, storing into VAR must be handled specially
2456 by storing into a temporary and copying that into VAR
2457 with a new insn after this one. Note that this case
2458 will be used when storing into a promoted scalar since
2459 the insn will now have different modes on the input
2460 and output and hence will be invalid (except for the case
2461 of setting it to a constant, which does not need any
2462 change if it is valid). We generate extra code in that case,
2463 but combine.c will eliminate it. */
2468 rtx fixeddest = SET_DEST (x);
2469 enum machine_mode temp_mode;
2471 /* STRICT_LOW_PART can be discarded, around a MEM. */
2472 if (GET_CODE (fixeddest) == STRICT_LOW_PART)
2473 fixeddest = XEXP (fixeddest, 0);
2474 /* Convert (SUBREG (MEM)) to a MEM in a changed mode. */
2475 if (GET_CODE (fixeddest) == SUBREG)
2477 fixeddest = fixup_memory_subreg (fixeddest, insn,
2479 temp_mode = GET_MODE (fixeddest);
2483 fixeddest = fixup_stack_1 (fixeddest, insn);
2484 temp_mode = promoted_mode;
2487 temp = gen_reg_rtx (temp_mode);
2489 emit_insn_after (gen_move_insn (fixeddest,
2490 gen_lowpart (GET_MODE (fixeddest),
2494 SET_DEST (x) = temp;
2502 /* Nothing special about this RTX; fix its operands. */
2504 fmt = GET_RTX_FORMAT (code);
2505 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2508 fixup_var_refs_1 (var, promoted_mode, &XEXP (x, i), insn, replacements,
2510 else if (fmt[i] == 'E')
2513 for (j = 0; j < XVECLEN (x, i); j++)
2514 fixup_var_refs_1 (var, promoted_mode, &XVECEXP (x, i, j),
2515 insn, replacements, no_share);
2520 /* Previously, X had the form (SUBREG:m1 (REG:PROMOTED_MODE ...)).
2521 The REG was placed on the stack, so X now has the form (SUBREG:m1
2524 Return an rtx (MEM:m1 newaddr) which is equivalent. If any insns
2525 must be emitted to compute NEWADDR, put them before INSN.
2527 UNCRITICAL nonzero means accept paradoxical subregs.
2528 This is used for subregs found inside REG_NOTES. */
2531 fixup_memory_subreg (rtx x, rtx insn, enum machine_mode promoted_mode, int uncritical)
2534 rtx mem = SUBREG_REG (x);
2535 rtx addr = XEXP (mem, 0);
2536 enum machine_mode mode = GET_MODE (x);
2539 /* Paradoxical SUBREGs are usually invalid during RTL generation. */
2540 if (GET_MODE_SIZE (mode) > GET_MODE_SIZE (GET_MODE (mem)) && ! uncritical)
2543 offset = SUBREG_BYTE (x);
2544 if (BYTES_BIG_ENDIAN)
2545 /* If the PROMOTED_MODE is wider than the mode of the MEM, adjust
2546 the offset so that it points to the right location within the
2548 offset -= (GET_MODE_SIZE (promoted_mode) - GET_MODE_SIZE (GET_MODE (mem)));
2550 if (!flag_force_addr
2551 && memory_address_p (mode, plus_constant (addr, offset)))
2552 /* Shortcut if no insns need be emitted. */
2553 return adjust_address (mem, mode, offset);
2556 result = adjust_address (mem, mode, offset);
2560 emit_insn_before (seq, insn);
2564 /* Do fixup_memory_subreg on all (SUBREG (VAR) ...) contained in X.
2565 VAR is a MEM that used to be a pseudo register with mode PROMOTED_MODE.
2566 Replace subexpressions of X in place.
2567 If X itself is a (SUBREG (VAR) ...), return the replacement expression.
2568 Otherwise return X, with its contents possibly altered.
2570 INSN and UNCRITICAL are as for fixup_memory_subreg. */
2573 walk_fixup_memory_subreg (rtx x, rtx insn, rtx var,
2574 enum machine_mode promoted_mode, int uncritical)
2583 code = GET_CODE (x);
2585 if (code == SUBREG && SUBREG_REG (x) == var)
2586 return fixup_memory_subreg (x, insn, promoted_mode, uncritical);
2588 /* Nothing special about this RTX; fix its operands. */
2590 fmt = GET_RTX_FORMAT (code);
2591 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2594 XEXP (x, i) = walk_fixup_memory_subreg (XEXP (x, i), insn, var,
2595 promoted_mode, uncritical);
2596 else if (fmt[i] == 'E')
2599 for (j = 0; j < XVECLEN (x, i); j++)
2601 = walk_fixup_memory_subreg (XVECEXP (x, i, j), insn, var,
2602 promoted_mode, uncritical);
2608 /* For each memory ref within X, if it refers to a stack slot
2609 with an out of range displacement, put the address in a temp register
2610 (emitting new insns before INSN to load these registers)
2611 and alter the memory ref to use that register.
2612 Replace each such MEM rtx with a copy, to avoid clobberage. */
2615 fixup_stack_1 (rtx x, rtx insn)
2618 RTX_CODE code = GET_CODE (x);
2623 rtx ad = XEXP (x, 0);
2624 /* If we have address of a stack slot but it's not valid
2625 (displacement is too large), compute the sum in a register. */
2626 if (GET_CODE (ad) == PLUS
2627 && REG_P (XEXP (ad, 0))
2628 && ((REGNO (XEXP (ad, 0)) >= FIRST_VIRTUAL_REGISTER
2629 && REGNO (XEXP (ad, 0)) <= LAST_VIRTUAL_REGISTER)
2630 || REGNO (XEXP (ad, 0)) == FRAME_POINTER_REGNUM
2631 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
2632 || REGNO (XEXP (ad, 0)) == HARD_FRAME_POINTER_REGNUM
2634 || REGNO (XEXP (ad, 0)) == STACK_POINTER_REGNUM
2635 || REGNO (XEXP (ad, 0)) == ARG_POINTER_REGNUM
2636 || XEXP (ad, 0) == current_function_internal_arg_pointer)
2637 && GET_CODE (XEXP (ad, 1)) == CONST_INT)
2640 if (memory_address_p (GET_MODE (x), ad))
2644 temp = copy_to_reg (ad);
2647 emit_insn_before (seq, insn);
2648 return replace_equiv_address (x, temp);
2653 fmt = GET_RTX_FORMAT (code);
2654 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2657 XEXP (x, i) = fixup_stack_1 (XEXP (x, i), insn);
2658 else if (fmt[i] == 'E')
2661 for (j = 0; j < XVECLEN (x, i); j++)
2662 XVECEXP (x, i, j) = fixup_stack_1 (XVECEXP (x, i, j), insn);
2668 /* Optimization: a bit-field instruction whose field
2669 happens to be a byte or halfword in memory
2670 can be changed to a move instruction.
2672 We call here when INSN is an insn to examine or store into a bit-field.
2673 BODY is the SET-rtx to be altered.
2675 EQUIV_MEM is the table `reg_equiv_mem' if that is available; else 0.
2676 (Currently this is called only from function.c, and EQUIV_MEM
2680 optimize_bit_field (rtx body, rtx insn, rtx *equiv_mem)
2685 enum machine_mode mode;
2687 if (GET_CODE (SET_DEST (body)) == SIGN_EXTRACT
2688 || GET_CODE (SET_DEST (body)) == ZERO_EXTRACT)
2689 bitfield = SET_DEST (body), destflag = 1;
2691 bitfield = SET_SRC (body), destflag = 0;
2693 /* First check that the field being stored has constant size and position
2694 and is in fact a byte or halfword suitably aligned. */
2696 if (GET_CODE (XEXP (bitfield, 1)) == CONST_INT
2697 && GET_CODE (XEXP (bitfield, 2)) == CONST_INT
2698 && ((mode = mode_for_size (INTVAL (XEXP (bitfield, 1)), MODE_INT, 1))
2700 && INTVAL (XEXP (bitfield, 2)) % INTVAL (XEXP (bitfield, 1)) == 0)
2704 /* Now check that the containing word is memory, not a register,
2705 and that it is safe to change the machine mode. */
2707 if (GET_CODE (XEXP (bitfield, 0)) == MEM)
2708 memref = XEXP (bitfield, 0);
2709 else if (REG_P (XEXP (bitfield, 0))
2711 memref = equiv_mem[REGNO (XEXP (bitfield, 0))];
2712 else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
2713 && GET_CODE (SUBREG_REG (XEXP (bitfield, 0))) == MEM)
2714 memref = SUBREG_REG (XEXP (bitfield, 0));
2715 else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
2717 && REG_P (SUBREG_REG (XEXP (bitfield, 0))))
2718 memref = equiv_mem[REGNO (SUBREG_REG (XEXP (bitfield, 0)))];
2721 && ! mode_dependent_address_p (XEXP (memref, 0))
2722 && ! MEM_VOLATILE_P (memref))
2724 /* Now adjust the address, first for any subreg'ing
2725 that we are now getting rid of,
2726 and then for which byte of the word is wanted. */
2728 HOST_WIDE_INT offset = INTVAL (XEXP (bitfield, 2));
2731 /* Adjust OFFSET to count bits from low-address byte. */
2732 if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN)
2733 offset = (GET_MODE_BITSIZE (GET_MODE (XEXP (bitfield, 0)))
2734 - offset - INTVAL (XEXP (bitfield, 1)));
2736 /* Adjust OFFSET to count bytes from low-address byte. */
2737 offset /= BITS_PER_UNIT;
2738 if (GET_CODE (XEXP (bitfield, 0)) == SUBREG)
2740 offset += (SUBREG_BYTE (XEXP (bitfield, 0))
2741 / UNITS_PER_WORD) * UNITS_PER_WORD;
2742 if (BYTES_BIG_ENDIAN)
2743 offset -= (MIN (UNITS_PER_WORD,
2744 GET_MODE_SIZE (GET_MODE (XEXP (bitfield, 0))))
2745 - MIN (UNITS_PER_WORD,
2746 GET_MODE_SIZE (GET_MODE (memref))));
2750 memref = adjust_address (memref, mode, offset);
2751 insns = get_insns ();
2753 emit_insn_before (insns, insn);
2755 /* Store this memory reference where
2756 we found the bit field reference. */
2760 validate_change (insn, &SET_DEST (body), memref, 1);
2761 if (! CONSTANT_ADDRESS_P (SET_SRC (body)))
2763 rtx src = SET_SRC (body);
2764 while (GET_CODE (src) == SUBREG
2765 && SUBREG_BYTE (src) == 0)
2766 src = SUBREG_REG (src);
2767 if (GET_MODE (src) != GET_MODE (memref))
2768 src = gen_lowpart (GET_MODE (memref), SET_SRC (body));
2769 validate_change (insn, &SET_SRC (body), src, 1);
2771 else if (GET_MODE (SET_SRC (body)) != VOIDmode
2772 && GET_MODE (SET_SRC (body)) != GET_MODE (memref))
2773 /* This shouldn't happen because anything that didn't have
2774 one of these modes should have got converted explicitly
2775 and then referenced through a subreg.
2776 This is so because the original bit-field was
2777 handled by agg_mode and so its tree structure had
2778 the same mode that memref now has. */
2783 rtx dest = SET_DEST (body);
2785 while (GET_CODE (dest) == SUBREG
2786 && SUBREG_BYTE (dest) == 0
2787 && (GET_MODE_CLASS (GET_MODE (dest))
2788 == GET_MODE_CLASS (GET_MODE (SUBREG_REG (dest))))
2789 && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest)))
2791 dest = SUBREG_REG (dest);
2793 validate_change (insn, &SET_DEST (body), dest, 1);
2795 if (GET_MODE (dest) == GET_MODE (memref))
2796 validate_change (insn, &SET_SRC (body), memref, 1);
2799 /* Convert the mem ref to the destination mode. */
2800 rtx newreg = gen_reg_rtx (GET_MODE (dest));
2803 convert_move (newreg, memref,
2804 GET_CODE (SET_SRC (body)) == ZERO_EXTRACT);
2808 validate_change (insn, &SET_SRC (body), newreg, 1);
2812 /* See if we can convert this extraction or insertion into
2813 a simple move insn. We might not be able to do so if this
2814 was, for example, part of a PARALLEL.
2816 If we succeed, write out any needed conversions. If we fail,
2817 it is hard to guess why we failed, so don't do anything
2818 special; just let the optimization be suppressed. */
2820 if (apply_change_group () && seq)
2821 emit_insn_before (seq, insn);
2826 /* These routines are responsible for converting virtual register references
2827 to the actual hard register references once RTL generation is complete.
2829 The following four variables are used for communication between the
2830 routines. They contain the offsets of the virtual registers from their
2831 respective hard registers. */
2833 static int in_arg_offset;
2834 static int var_offset;
2835 static int dynamic_offset;
2836 static int out_arg_offset;
2837 static int cfa_offset;
2839 /* In most machines, the stack pointer register is equivalent to the bottom
2842 #ifndef STACK_POINTER_OFFSET
2843 #define STACK_POINTER_OFFSET 0
2846 /* If not defined, pick an appropriate default for the offset of dynamically
2847 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
2848 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
2850 #ifndef STACK_DYNAMIC_OFFSET
2852 /* The bottom of the stack points to the actual arguments. If
2853 REG_PARM_STACK_SPACE is defined, this includes the space for the register
2854 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
2855 stack space for register parameters is not pushed by the caller, but
2856 rather part of the fixed stack areas and hence not included in
2857 `current_function_outgoing_args_size'. Nevertheless, we must allow
2858 for it when allocating stack dynamic objects. */
2860 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
2861 #define STACK_DYNAMIC_OFFSET(FNDECL) \
2862 ((ACCUMULATE_OUTGOING_ARGS \
2863 ? (current_function_outgoing_args_size + REG_PARM_STACK_SPACE (FNDECL)) : 0)\
2864 + (STACK_POINTER_OFFSET)) \
2867 #define STACK_DYNAMIC_OFFSET(FNDECL) \
2868 ((ACCUMULATE_OUTGOING_ARGS ? current_function_outgoing_args_size : 0) \
2869 + (STACK_POINTER_OFFSET))
2873 /* On most machines, the CFA coincides with the first incoming parm. */
2875 #ifndef ARG_POINTER_CFA_OFFSET
2876 #define ARG_POINTER_CFA_OFFSET(FNDECL) FIRST_PARM_OFFSET (FNDECL)
2879 /* Build up a (MEM (ADDRESSOF (REG))) rtx for a register REG that just
2880 had its address taken. DECL is the decl or SAVE_EXPR for the
2881 object stored in the register, for later use if we do need to force
2882 REG into the stack. REG is overwritten by the MEM like in
2883 put_reg_into_stack. RESCAN is true if previously emitted
2884 instructions must be rescanned and modified now that the REG has
2885 been transformed. */
2888 gen_mem_addressof (rtx reg, tree decl, int rescan)
2890 rtx r = gen_rtx_ADDRESSOF (Pmode, gen_reg_rtx (GET_MODE (reg)),
2893 /* Calculate this before we start messing with decl's RTL. */
2894 HOST_WIDE_INT set = decl ? get_alias_set (decl) : 0;
2896 /* If the original REG was a user-variable, then so is the REG whose
2897 address is being taken. Likewise for unchanging. */
2898 REG_USERVAR_P (XEXP (r, 0)) = REG_USERVAR_P (reg);
2899 RTX_UNCHANGING_P (XEXP (r, 0)) = RTX_UNCHANGING_P (reg);
2901 PUT_CODE (reg, MEM);
2902 MEM_VOLATILE_P (reg) = 0;
2903 MEM_ATTRS (reg) = 0;
2908 tree type = TREE_TYPE (decl);
2909 enum machine_mode decl_mode
2910 = (DECL_P (decl) ? DECL_MODE (decl) : TYPE_MODE (TREE_TYPE (decl)));
2911 rtx decl_rtl = (TREE_CODE (decl) == SAVE_EXPR ? SAVE_EXPR_RTL (decl)
2912 : DECL_RTL_IF_SET (decl));
2914 PUT_MODE (reg, decl_mode);
2916 /* Clear DECL_RTL momentarily so functions below will work
2917 properly, then set it again. */
2918 if (DECL_P (decl) && decl_rtl == reg)
2919 SET_DECL_RTL (decl, 0);
2921 set_mem_attributes (reg, decl, 1);
2922 set_mem_alias_set (reg, set);
2924 if (DECL_P (decl) && decl_rtl == reg)
2925 SET_DECL_RTL (decl, reg);
2928 && (TREE_USED (decl) || (DECL_P (decl) && DECL_INITIAL (decl) != 0)))
2929 fixup_var_refs (reg, GET_MODE (reg), TYPE_UNSIGNED (type), reg, 0);
2933 /* This can only happen during reload. Clear the same flag bits as
2935 RTX_UNCHANGING_P (reg) = 0;
2936 MEM_IN_STRUCT_P (reg) = 0;
2937 MEM_SCALAR_P (reg) = 0;
2939 fixup_var_refs (reg, GET_MODE (reg), 0, reg, 0);
2945 /* If DECL has an RTL that is an ADDRESSOF rtx, put it into the stack. */
2948 flush_addressof (tree decl)
2950 if ((TREE_CODE (decl) == PARM_DECL || TREE_CODE (decl) == VAR_DECL)
2951 && DECL_RTL (decl) != 0
2952 && GET_CODE (DECL_RTL (decl)) == MEM
2953 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == ADDRESSOF
2954 && REG_P (XEXP (XEXP (DECL_RTL (decl), 0), 0)))
2955 put_addressof_into_stack (XEXP (DECL_RTL (decl), 0), 0);
2958 /* Force the register pointed to by R, an ADDRESSOF rtx, into the stack. */
2961 put_addressof_into_stack (rtx r, htab_t ht)
2964 bool volatile_p, used_p;
2966 rtx reg = XEXP (r, 0);
2971 decl = ADDRESSOF_DECL (r);
2974 type = TREE_TYPE (decl);
2975 volatile_p = (TREE_CODE (decl) != SAVE_EXPR
2976 && TREE_THIS_VOLATILE (decl));
2977 used_p = (TREE_USED (decl)
2978 || (DECL_P (decl) && DECL_INITIAL (decl) != 0));
2987 put_reg_into_stack (0, reg, type, GET_MODE (reg), ADDRESSOF_REGNO (r),
2988 volatile_p, used_p, false, ht);
2991 /* List of replacements made below in purge_addressof_1 when creating
2992 bitfield insertions. */
2993 static rtx purge_bitfield_addressof_replacements;
2995 /* List of replacements made below in purge_addressof_1 for patterns
2996 (MEM (ADDRESSOF (REG ...))). The key of the list entry is the
2997 corresponding (ADDRESSOF (REG ...)) and value is a substitution for
2998 the all pattern. List PURGE_BITFIELD_ADDRESSOF_REPLACEMENTS is not
2999 enough in complex cases, e.g. when some field values can be
3000 extracted by usage MEM with narrower mode. */
3001 static rtx purge_addressof_replacements;
3003 /* Helper function for purge_addressof. See if the rtx expression at *LOC
3004 in INSN needs to be changed. If FORCE, always put any ADDRESSOFs into
3005 the stack. If the function returns FALSE then the replacement could not
3006 be made. If MAY_POSTPONE is true and we would not put the addressof
3007 to stack, postpone processing of the insn. */
3010 purge_addressof_1 (rtx *loc, rtx insn, int force, int store, int may_postpone,
3018 bool libcall = false;
3020 /* Re-start here to avoid recursion in common cases. */
3027 /* Is this a libcall? */
3029 libcall = REG_NOTE_KIND (*loc) == REG_RETVAL;
3031 code = GET_CODE (x);
3033 /* If we don't return in any of the cases below, we will recurse inside
3034 the RTX, which will normally result in any ADDRESSOF being forced into
3038 result = purge_addressof_1 (&SET_DEST (x), insn, force, 1,
3040 result &= purge_addressof_1 (&SET_SRC (x), insn, force, 0,
3044 else if (code == ADDRESSOF)
3048 if (GET_CODE (XEXP (x, 0)) != MEM)
3049 put_addressof_into_stack (x, ht);
3051 /* We must create a copy of the rtx because it was created by
3052 overwriting a REG rtx which is always shared. */
3053 sub = copy_rtx (XEXP (XEXP (x, 0), 0));
3054 if (validate_change (insn, loc, sub, 0)
3055 || validate_replace_rtx (x, sub, insn))
3060 /* If SUB is a hard or virtual register, try it as a pseudo-register.
3061 Otherwise, perhaps SUB is an expression, so generate code to compute
3063 if (REG_P (sub) && REGNO (sub) <= LAST_VIRTUAL_REGISTER)
3064 sub = copy_to_reg (sub);
3066 sub = force_operand (sub, NULL_RTX);
3068 if (! validate_change (insn, loc, sub, 0)
3069 && ! validate_replace_rtx (x, sub, insn))
3072 insns = get_insns ();
3074 emit_insn_before (insns, insn);
3078 else if (code == MEM && GET_CODE (XEXP (x, 0)) == ADDRESSOF && ! force)
3080 rtx sub = XEXP (XEXP (x, 0), 0);
3082 if (GET_CODE (sub) == MEM)
3083 sub = adjust_address_nv (sub, GET_MODE (x), 0);
3084 else if (REG_P (sub)
3085 && (MEM_VOLATILE_P (x) || GET_MODE (x) == BLKmode))
3087 else if (REG_P (sub) && GET_MODE (x) != GET_MODE (sub))
3089 int size_x, size_sub;
3093 /* Postpone for now, so that we do not emit bitfield arithmetics
3094 unless there is some benefit from it. */
3095 if (!postponed_insns || XEXP (postponed_insns, 0) != insn)
3096 postponed_insns = alloc_INSN_LIST (insn, postponed_insns);
3102 /* When processing REG_NOTES look at the list of
3103 replacements done on the insn to find the register that X
3107 for (tem = purge_bitfield_addressof_replacements;
3109 tem = XEXP (XEXP (tem, 1), 1))
3110 if (rtx_equal_p (x, XEXP (tem, 0)))
3112 *loc = XEXP (XEXP (tem, 1), 0);
3116 /* See comment for purge_addressof_replacements. */
3117 for (tem = purge_addressof_replacements;
3119 tem = XEXP (XEXP (tem, 1), 1))
3120 if (rtx_equal_p (XEXP (x, 0), XEXP (tem, 0)))
3122 rtx z = XEXP (XEXP (tem, 1), 0);
3124 if (GET_MODE (x) == GET_MODE (z)
3125 || (!REG_P (XEXP (XEXP (tem, 1), 0))
3126 && GET_CODE (XEXP (XEXP (tem, 1), 0)) != SUBREG))
3129 /* It can happen that the note may speak of things
3130 in a wider (or just different) mode than the
3131 code did. This is especially true of
3134 if (GET_CODE (z) == SUBREG && SUBREG_BYTE (z) == 0)
3137 if (GET_MODE_SIZE (GET_MODE (x)) > UNITS_PER_WORD
3138 && (GET_MODE_SIZE (GET_MODE (x))
3139 > GET_MODE_SIZE (GET_MODE (z))))
3141 /* This can occur as a result in invalid
3142 pointer casts, e.g. float f; ...
3143 *(long long int *)&f.
3144 ??? We could emit a warning here, but
3145 without a line number that wouldn't be
3147 z = gen_rtx_SUBREG (GET_MODE (x), z, 0);
3150 z = gen_lowpart (GET_MODE (x), z);
3156 /* When we are processing the REG_NOTES of the last instruction
3157 of a libcall, there will be typically no replacements
3158 for that insn; the replacements happened before, piecemeal
3159 fashion. OTOH we are not interested in the details of
3160 this for the REG_EQUAL note, we want to know the big picture,
3161 which can be succinctly described with a simple SUBREG.
3162 Note that removing the REG_EQUAL note is not an option
3163 on the last insn of a libcall, so we must do a replacement. */
3165 /* In compile/990107-1.c:7 compiled at -O1 -m1 for sh-elf,
3167 (mem:DI (addressof:SI (reg/v:DF 160) 159 0x401c8510)
3168 [0 S8 A32]), which can be expressed with a simple
3170 if ((GET_MODE_SIZE (GET_MODE (x))
3171 <= GET_MODE_SIZE (GET_MODE (sub)))
3172 /* Again, invalid pointer casts (as in
3173 compile/990203-1.c) can require paradoxical
3175 || (GET_MODE_SIZE (GET_MODE (x)) > UNITS_PER_WORD
3176 && (GET_MODE_SIZE (GET_MODE (x))
3177 > GET_MODE_SIZE (GET_MODE (sub)))
3180 *loc = gen_rtx_SUBREG (GET_MODE (x), sub, 0);
3183 /* ??? Are there other cases we should handle? */
3185 /* Sometimes we may not be able to find the replacement. For
3186 example when the original insn was a MEM in a wider mode,
3187 and the note is part of a sign extension of a narrowed
3188 version of that MEM. Gcc testcase compile/990829-1.c can
3189 generate an example of this situation. Rather than complain
3190 we return false, which will prompt our caller to remove the
3195 size_x = GET_MODE_BITSIZE (GET_MODE (x));
3196 size_sub = GET_MODE_BITSIZE (GET_MODE (sub));
3198 /* Do not frob unchanging MEMs. If a later reference forces the
3199 pseudo to the stack, we can wind up with multiple writes to
3200 an unchanging memory, which is invalid. */
3201 if (RTX_UNCHANGING_P (x) && size_x != size_sub)
3204 /* Don't even consider working with paradoxical subregs,
3205 or the moral equivalent seen here. */
3206 else if (size_x <= size_sub
3207 && int_mode_for_mode (GET_MODE (sub)) != BLKmode)
3209 /* Do a bitfield insertion to mirror what would happen
3216 rtx p = PREV_INSN (insn);
3219 val = gen_reg_rtx (GET_MODE (x));
3220 if (! validate_change (insn, loc, val, 0))
3222 /* Discard the current sequence and put the
3223 ADDRESSOF on stack. */
3229 emit_insn_before (seq, insn);
3230 compute_insns_for_mem (p ? NEXT_INSN (p) : get_insns (),
3234 store_bit_field (sub, size_x, 0, GET_MODE (x),
3235 val, GET_MODE_SIZE (GET_MODE (sub)));
3237 /* Make sure to unshare any shared rtl that store_bit_field
3238 might have created. */
3239 unshare_all_rtl_again (get_insns ());
3243 p = emit_insn_after (seq, insn);
3244 if (NEXT_INSN (insn))
3245 compute_insns_for_mem (NEXT_INSN (insn),
3246 p ? NEXT_INSN (p) : NULL_RTX,
3251 rtx p = PREV_INSN (insn);
3254 val = extract_bit_field (sub, size_x, 0, 1, NULL_RTX,
3255 GET_MODE (x), GET_MODE (x),
3256 GET_MODE_SIZE (GET_MODE (sub)));
3258 if (! validate_change (insn, loc, val, 0))
3260 /* Discard the current sequence and put the
3261 ADDRESSOF on stack. */
3268 emit_insn_before (seq, insn);
3269 compute_insns_for_mem (p ? NEXT_INSN (p) : get_insns (),
3273 /* Remember the replacement so that the same one can be done
3274 on the REG_NOTES. */
3275 purge_bitfield_addressof_replacements
3276 = gen_rtx_EXPR_LIST (VOIDmode, x,
3279 purge_bitfield_addressof_replacements));
3281 /* We replaced with a reg -- all done. */
3286 else if (validate_change (insn, loc, sub, 0))
3288 /* Remember the replacement so that the same one can be done
3289 on the REG_NOTES. */
3290 if (REG_P (sub) || GET_CODE (sub) == SUBREG)
3294 for (tem = purge_addressof_replacements;
3296 tem = XEXP (XEXP (tem, 1), 1))
3297 if (rtx_equal_p (XEXP (x, 0), XEXP (tem, 0)))
3299 XEXP (XEXP (tem, 1), 0) = sub;
3302 purge_addressof_replacements
3303 = gen_rtx_EXPR_LIST (VOIDmode, XEXP (x, 0),
3304 gen_rtx_EXPR_LIST (VOIDmode, sub,
3305 purge_addressof_replacements));
3313 /* Scan all subexpressions. */
3314 fmt = GET_RTX_FORMAT (code);
3315 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
3318 result &= purge_addressof_1 (&XEXP (x, i), insn, force, 0,
3320 else if (*fmt == 'E')
3321 for (j = 0; j < XVECLEN (x, i); j++)
3322 result &= purge_addressof_1 (&XVECEXP (x, i, j), insn, force, 0,
3329 /* Return a hash value for K, a REG. */
3332 insns_for_mem_hash (const void *k)
3334 /* Use the address of the key for the hash value. */
3335 struct insns_for_mem_entry *m = (struct insns_for_mem_entry *) k;
3336 return htab_hash_pointer (m->key);
3339 /* Return nonzero if K1 and K2 (two REGs) are the same. */
3342 insns_for_mem_comp (const void *k1, const void *k2)
3344 struct insns_for_mem_entry *m1 = (struct insns_for_mem_entry *) k1;
3345 struct insns_for_mem_entry *m2 = (struct insns_for_mem_entry *) k2;
3346 return m1->key == m2->key;
3349 struct insns_for_mem_walk_info
3351 /* The hash table that we are using to record which INSNs use which
3355 /* The INSN we are currently processing. */
3358 /* Zero if we are walking to find ADDRESSOFs, one if we are walking
3359 to find the insns that use the REGs in the ADDRESSOFs. */
3363 /* Called from compute_insns_for_mem via for_each_rtx. If R is a REG
3364 that might be used in an ADDRESSOF expression, record this INSN in
3365 the hash table given by DATA (which is really a pointer to an
3366 insns_for_mem_walk_info structure). */
3369 insns_for_mem_walk (rtx *r, void *data)
3371 struct insns_for_mem_walk_info *ifmwi
3372 = (struct insns_for_mem_walk_info *) data;
3373 struct insns_for_mem_entry tmp;
3374 tmp.insns = NULL_RTX;
3376 if (ifmwi->pass == 0 && *r && GET_CODE (*r) == ADDRESSOF
3377 && REG_P (XEXP (*r, 0)))
3380 tmp.key = XEXP (*r, 0);
3381 e = htab_find_slot (ifmwi->ht, &tmp, INSERT);
3384 *e = ggc_alloc (sizeof (tmp));
3385 memcpy (*e, &tmp, sizeof (tmp));
3388 else if (ifmwi->pass == 1 && *r && REG_P (*r))
3390 struct insns_for_mem_entry *ifme;
3392 ifme = htab_find (ifmwi->ht, &tmp);
3394 /* If we have not already recorded this INSN, do so now. Since
3395 we process the INSNs in order, we know that if we have
3396 recorded it it must be at the front of the list. */
3397 if (ifme && (!ifme->insns || XEXP (ifme->insns, 0) != ifmwi->insn))
3398 ifme->insns = gen_rtx_EXPR_LIST (VOIDmode, ifmwi->insn,
3405 /* Walk the INSNS, until we reach LAST_INSN, recording which INSNs use
3406 which REGs in HT. */
3409 compute_insns_for_mem (rtx insns, rtx last_insn, htab_t ht)
3412 struct insns_for_mem_walk_info ifmwi;
3415 for (ifmwi.pass = 0; ifmwi.pass < 2; ++ifmwi.pass)
3416 for (insn = insns; insn != last_insn; insn = NEXT_INSN (insn))
3420 for_each_rtx (&insn, insns_for_mem_walk, &ifmwi);
3424 /* Helper function for purge_addressof called through for_each_rtx.
3425 Returns true iff the rtl is an ADDRESSOF. */
3428 is_addressof (rtx *rtl, void *data ATTRIBUTE_UNUSED)
3430 return GET_CODE (*rtl) == ADDRESSOF;
3433 /* Eliminate all occurrences of ADDRESSOF from INSNS. Elide any remaining
3434 (MEM (ADDRESSOF)) patterns, and force any needed registers into the
3438 purge_addressof (rtx insns)
3443 /* When we actually purge ADDRESSOFs, we turn REGs into MEMs. That
3444 requires a fixup pass over the instruction stream to correct
3445 INSNs that depended on the REG being a REG, and not a MEM. But,
3446 these fixup passes are slow. Furthermore, most MEMs are not
3447 mentioned in very many instructions. So, we speed up the process
3448 by pre-calculating which REGs occur in which INSNs; that allows
3449 us to perform the fixup passes much more quickly. */
3450 ht = htab_create_ggc (1000, insns_for_mem_hash, insns_for_mem_comp, NULL);
3451 compute_insns_for_mem (insns, NULL_RTX, ht);
3453 postponed_insns = NULL;
3455 for (insn = insns; insn; insn = NEXT_INSN (insn))
3458 if (! purge_addressof_1 (&PATTERN (insn), insn,
3459 asm_noperands (PATTERN (insn)) > 0, 0, 1, ht))
3460 /* If we could not replace the ADDRESSOFs in the insn,
3461 something is wrong. */
3464 if (! purge_addressof_1 (®_NOTES (insn), NULL_RTX, 0, 0, 0, ht))
3466 /* If we could not replace the ADDRESSOFs in the insn's notes,
3467 we can just remove the offending notes instead. */
3470 for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
3472 /* If we find a REG_RETVAL note then the insn is a libcall.
3473 Such insns must have REG_EQUAL notes as well, in order
3474 for later passes of the compiler to work. So it is not
3475 safe to delete the notes here, and instead we abort. */
3476 if (REG_NOTE_KIND (note) == REG_RETVAL)
3478 if (for_each_rtx (¬e, is_addressof, NULL))
3479 remove_note (insn, note);
3484 /* Process the postponed insns. */
3485 while (postponed_insns)
3487 insn = XEXP (postponed_insns, 0);
3488 tmp = postponed_insns;
3489 postponed_insns = XEXP (postponed_insns, 1);
3490 free_INSN_LIST_node (tmp);
3492 if (! purge_addressof_1 (&PATTERN (insn), insn,
3493 asm_noperands (PATTERN (insn)) > 0, 0, 0, ht))
3498 purge_bitfield_addressof_replacements = 0;
3499 purge_addressof_replacements = 0;
3501 /* REGs are shared. purge_addressof will destructively replace a REG
3502 with a MEM, which creates shared MEMs.
3504 Unfortunately, the children of put_reg_into_stack assume that MEMs
3505 referring to the same stack slot are shared (fixup_var_refs and
3506 the associated hash table code).
3508 So, we have to do another unsharing pass after we have flushed any
3509 REGs that had their address taken into the stack.
3511 It may be worth tracking whether or not we converted any REGs into
3512 MEMs to avoid this overhead when it is not needed. */
3513 unshare_all_rtl_again (get_insns ());
3516 /* Convert a SET of a hard subreg to a set of the appropriate hard
3517 register. A subroutine of purge_hard_subreg_sets. */
3520 purge_single_hard_subreg_set (rtx pattern)
3522 rtx reg = SET_DEST (pattern);
3523 enum machine_mode mode = GET_MODE (SET_DEST (pattern));
3526 if (GET_CODE (reg) == SUBREG && REG_P (SUBREG_REG (reg))
3527 && REGNO (SUBREG_REG (reg)) < FIRST_PSEUDO_REGISTER)
3529 offset = subreg_regno_offset (REGNO (SUBREG_REG (reg)),
3530 GET_MODE (SUBREG_REG (reg)),
3533 reg = SUBREG_REG (reg);
3537 if (REG_P (reg) && REGNO (reg) < FIRST_PSEUDO_REGISTER)
3539 reg = gen_rtx_REG (mode, REGNO (reg) + offset);
3540 SET_DEST (pattern) = reg;
3544 /* Eliminate all occurrences of SETs of hard subregs from INSNS. The
3545 only such SETs that we expect to see are those left in because
3546 integrate can't handle sets of parts of a return value register.
3548 We don't use alter_subreg because we only want to eliminate subregs
3549 of hard registers. */
3552 purge_hard_subreg_sets (rtx insn)
3554 for (; insn; insn = NEXT_INSN (insn))
3558 rtx pattern = PATTERN (insn);
3559 switch (GET_CODE (pattern))
3562 if (GET_CODE (SET_DEST (pattern)) == SUBREG)
3563 purge_single_hard_subreg_set (pattern);
3568 for (j = XVECLEN (pattern, 0) - 1; j >= 0; j--)
3570 rtx inner_pattern = XVECEXP (pattern, 0, j);
3571 if (GET_CODE (inner_pattern) == SET
3572 && GET_CODE (SET_DEST (inner_pattern)) == SUBREG)
3573 purge_single_hard_subreg_set (inner_pattern);
3584 /* Pass through the INSNS of function FNDECL and convert virtual register
3585 references to hard register references. */
3588 instantiate_virtual_regs (void)
3593 /* Compute the offsets to use for this function. */
3594 in_arg_offset = FIRST_PARM_OFFSET (current_function_decl);
3595 var_offset = STARTING_FRAME_OFFSET;
3596 dynamic_offset = STACK_DYNAMIC_OFFSET (current_function_decl);
3597 out_arg_offset = STACK_POINTER_OFFSET;
3598 cfa_offset = ARG_POINTER_CFA_OFFSET (current_function_decl);
3600 /* Scan all variables and parameters of this function. For each that is
3601 in memory, instantiate all virtual registers if the result is a valid
3602 address. If not, we do it later. That will handle most uses of virtual
3603 regs on many machines. */
3604 instantiate_decls (current_function_decl, 1);
3606 /* Initialize recognition, indicating that volatile is OK. */
3609 /* Scan through all the insns, instantiating every virtual register still
3611 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3612 if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN
3613 || GET_CODE (insn) == CALL_INSN)
3615 instantiate_virtual_regs_1 (&PATTERN (insn), insn, 1);
3616 if (INSN_DELETED_P (insn))
3618 instantiate_virtual_regs_1 (®_NOTES (insn), NULL_RTX, 0);
3619 /* Instantiate any virtual registers in CALL_INSN_FUNCTION_USAGE. */
3620 if (GET_CODE (insn) == CALL_INSN)
3621 instantiate_virtual_regs_1 (&CALL_INSN_FUNCTION_USAGE (insn),
3624 /* Past this point all ASM statements should match. Verify that
3625 to avoid failures later in the compilation process. */
3626 if (asm_noperands (PATTERN (insn)) >= 0
3627 && ! check_asm_operands (PATTERN (insn)))
3628 instantiate_virtual_regs_lossage (insn);
3631 /* Instantiate the stack slots for the parm registers, for later use in
3632 addressof elimination. */
3633 for (i = 0; i < max_parm_reg; ++i)
3634 if (parm_reg_stack_loc[i])
3635 instantiate_virtual_regs_1 (&parm_reg_stack_loc[i], NULL_RTX, 0);
3637 /* Now instantiate the remaining register equivalences for debugging info.
3638 These will not be valid addresses. */
3639 instantiate_decls (current_function_decl, 0);
3641 /* Indicate that, from now on, assign_stack_local should use
3642 frame_pointer_rtx. */
3643 virtuals_instantiated = 1;
3646 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
3647 all virtual registers in their DECL_RTL's.
3649 If VALID_ONLY, do this only if the resulting address is still valid.
3650 Otherwise, always do it. */
3653 instantiate_decls (tree fndecl, int valid_only)
3657 /* Process all parameters of the function. */
3658 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = TREE_CHAIN (decl))
3660 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (decl));
3661 HOST_WIDE_INT size_rtl;
3663 instantiate_decl (DECL_RTL (decl), size, valid_only);
3665 /* If the parameter was promoted, then the incoming RTL mode may be
3666 larger than the declared type size. We must use the larger of
3668 size_rtl = GET_MODE_SIZE (GET_MODE (DECL_INCOMING_RTL (decl)));
3669 size = MAX (size_rtl, size);
3670 instantiate_decl (DECL_INCOMING_RTL (decl), size, valid_only);
3673 /* Now process all variables defined in the function or its subblocks. */
3674 instantiate_decls_1 (DECL_INITIAL (fndecl), valid_only);
3677 /* Subroutine of instantiate_decls: Process all decls in the given
3678 BLOCK node and all its subblocks. */
3681 instantiate_decls_1 (tree let, int valid_only)
3685 for (t = BLOCK_VARS (let); t; t = TREE_CHAIN (t))
3686 if (DECL_RTL_SET_P (t))
3687 instantiate_decl (DECL_RTL (t),
3688 int_size_in_bytes (TREE_TYPE (t)),
3691 /* Process all subblocks. */
3692 for (t = BLOCK_SUBBLOCKS (let); t; t = TREE_CHAIN (t))
3693 instantiate_decls_1 (t, valid_only);
3696 /* Subroutine of the preceding procedures: Given RTL representing a
3697 decl and the size of the object, do any instantiation required.
3699 If VALID_ONLY is nonzero, it means that the RTL should only be
3700 changed if the new address is valid. */
3703 instantiate_decl (rtx x, HOST_WIDE_INT size, int valid_only)
3705 enum machine_mode mode;
3708 /* If this is not a MEM, no need to do anything. Similarly if the
3709 address is a constant or a register that is not a virtual register. */
3711 if (x == 0 || GET_CODE (x) != MEM)
3715 if (CONSTANT_P (addr)
3716 || (GET_CODE (addr) == ADDRESSOF && REG_P (XEXP (addr, 0)))
3718 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
3719 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
3722 /* If we should only do this if the address is valid, copy the address.
3723 We need to do this so we can undo any changes that might make the
3724 address invalid. This copy is unfortunate, but probably can't be
3728 addr = copy_rtx (addr);
3730 instantiate_virtual_regs_1 (&addr, NULL_RTX, 0);
3732 if (valid_only && size >= 0)
3734 unsigned HOST_WIDE_INT decl_size = size;
3736 /* Now verify that the resulting address is valid for every integer or
3737 floating-point mode up to and including SIZE bytes long. We do this
3738 since the object might be accessed in any mode and frame addresses
3741 for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
3742 mode != VOIDmode && GET_MODE_SIZE (mode) <= decl_size;
3743 mode = GET_MODE_WIDER_MODE (mode))
3744 if (! memory_address_p (mode, addr))
3747 for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT);
3748 mode != VOIDmode && GET_MODE_SIZE (mode) <= decl_size;
3749 mode = GET_MODE_WIDER_MODE (mode))
3750 if (! memory_address_p (mode, addr))
3754 /* Put back the address now that we have updated it and we either know
3755 it is valid or we don't care whether it is valid. */
3760 /* Given a piece of RTX and a pointer to a HOST_WIDE_INT, if the RTX
3761 is a virtual register, return the equivalent hard register and set the
3762 offset indirectly through the pointer. Otherwise, return 0. */
3765 instantiate_new_reg (rtx x, HOST_WIDE_INT *poffset)
3768 HOST_WIDE_INT offset;
3770 if (x == virtual_incoming_args_rtx)
3771 new = arg_pointer_rtx, offset = in_arg_offset;
3772 else if (x == virtual_stack_vars_rtx)
3773 new = frame_pointer_rtx, offset = var_offset;
3774 else if (x == virtual_stack_dynamic_rtx)
3775 new = stack_pointer_rtx, offset = dynamic_offset;
3776 else if (x == virtual_outgoing_args_rtx)
3777 new = stack_pointer_rtx, offset = out_arg_offset;
3778 else if (x == virtual_cfa_rtx)
3779 new = arg_pointer_rtx, offset = cfa_offset;
3788 /* Called when instantiate_virtual_regs has failed to update the instruction.
3789 Usually this means that non-matching instruction has been emit, however for
3790 asm statements it may be the problem in the constraints. */
3792 instantiate_virtual_regs_lossage (rtx insn)
3794 if (asm_noperands (PATTERN (insn)) >= 0)
3796 error_for_asm (insn, "impossible constraint in `asm'");
3802 /* Given a pointer to a piece of rtx and an optional pointer to the
3803 containing object, instantiate any virtual registers present in it.
3805 If EXTRA_INSNS, we always do the replacement and generate
3806 any extra insns before OBJECT. If it zero, we do nothing if replacement
3809 Return 1 if we either had nothing to do or if we were able to do the
3810 needed replacement. Return 0 otherwise; we only return zero if
3811 EXTRA_INSNS is zero.
3813 We first try some simple transformations to avoid the creation of extra
3817 instantiate_virtual_regs_1 (rtx *loc, rtx object, int extra_insns)
3822 HOST_WIDE_INT offset = 0;
3828 /* Re-start here to avoid recursion in common cases. */
3835 /* We may have detected and deleted invalid asm statements. */
3836 if (object && INSN_P (object) && INSN_DELETED_P (object))
3839 code = GET_CODE (x);
3841 /* Check for some special cases. */
3859 /* We are allowed to set the virtual registers. This means that
3860 the actual register should receive the source minus the
3861 appropriate offset. This is used, for example, in the handling
3862 of non-local gotos. */
3863 if ((new = instantiate_new_reg (SET_DEST (x), &offset)) != 0)
3865 rtx src = SET_SRC (x);
3867 /* We are setting the register, not using it, so the relevant
3868 offset is the negative of the offset to use were we using
3871 instantiate_virtual_regs_1 (&src, NULL_RTX, 0);
3873 /* The only valid sources here are PLUS or REG. Just do
3874 the simplest possible thing to handle them. */
3875 if (!REG_P (src) && GET_CODE (src) != PLUS)
3877 instantiate_virtual_regs_lossage (object);
3883 temp = force_operand (src, NULL_RTX);
3886 temp = force_operand (plus_constant (temp, offset), NULL_RTX);
3890 emit_insn_before (seq, object);
3893 if (! validate_change (object, &SET_SRC (x), temp, 0)
3895 instantiate_virtual_regs_lossage (object);
3900 instantiate_virtual_regs_1 (&SET_DEST (x), object, extra_insns);
3905 /* Handle special case of virtual register plus constant. */
3906 if (CONSTANT_P (XEXP (x, 1)))
3908 rtx old, new_offset;
3910 /* Check for (plus (plus VIRT foo) (const_int)) first. */
3911 if (GET_CODE (XEXP (x, 0)) == PLUS)
3913 if ((new = instantiate_new_reg (XEXP (XEXP (x, 0), 0), &offset)))
3915 instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 1), object,
3917 new = gen_rtx_PLUS (Pmode, new, XEXP (XEXP (x, 0), 1));
3926 #ifdef POINTERS_EXTEND_UNSIGNED
3927 /* If we have (plus (subreg (virtual-reg)) (const_int)), we know
3928 we can commute the PLUS and SUBREG because pointers into the
3929 frame are well-behaved. */
3930 else if (GET_CODE (XEXP (x, 0)) == SUBREG && GET_MODE (x) == ptr_mode
3931 && GET_CODE (XEXP (x, 1)) == CONST_INT
3933 = instantiate_new_reg (SUBREG_REG (XEXP (x, 0)),
3935 && validate_change (object, loc,
3936 plus_constant (gen_lowpart (ptr_mode,
3939 + INTVAL (XEXP (x, 1))),
3943 else if ((new = instantiate_new_reg (XEXP (x, 0), &offset)) == 0)
3945 /* We know the second operand is a constant. Unless the
3946 first operand is a REG (which has been already checked),
3947 it needs to be checked. */
3948 if (!REG_P (XEXP (x, 0)))
3956 new_offset = plus_constant (XEXP (x, 1), offset);
3958 /* If the new constant is zero, try to replace the sum with just
3960 if (new_offset == const0_rtx
3961 && validate_change (object, loc, new, 0))
3964 /* Next try to replace the register and new offset.
3965 There are two changes to validate here and we can't assume that
3966 in the case of old offset equals new just changing the register
3967 will yield a valid insn. In the interests of a little efficiency,
3968 however, we only call validate change once (we don't queue up the
3969 changes and then call apply_change_group). */
3973 ? ! validate_change (object, &XEXP (x, 0), new, 0)
3974 : (XEXP (x, 0) = new,
3975 ! validate_change (object, &XEXP (x, 1), new_offset, 0)))
3983 /* Otherwise copy the new constant into a register and replace
3984 constant with that register. */
3985 temp = gen_reg_rtx (Pmode);
3987 if (validate_change (object, &XEXP (x, 1), temp, 0))
3988 emit_insn_before (gen_move_insn (temp, new_offset), object);
3991 /* If that didn't work, replace this expression with a
3992 register containing the sum. */
3995 new = gen_rtx_PLUS (Pmode, new, new_offset);
3998 temp = force_operand (new, NULL_RTX);
4002 emit_insn_before (seq, object);
4003 if (! validate_change (object, loc, temp, 0)
4004 && ! validate_replace_rtx (x, temp, object))
4006 instantiate_virtual_regs_lossage (object);
4015 /* Fall through to generic two-operand expression case. */
4021 case DIV: case UDIV:
4022 case MOD: case UMOD:
4023 case AND: case IOR: case XOR:
4024 case ROTATERT: case ROTATE:
4025 case ASHIFTRT: case LSHIFTRT: case ASHIFT:
4027 case GE: case GT: case GEU: case GTU:
4028 case LE: case LT: case LEU: case LTU:
4029 if (XEXP (x, 1) && ! CONSTANT_P (XEXP (x, 1)))
4030 instantiate_virtual_regs_1 (&XEXP (x, 1), object, extra_insns);
4035 /* Most cases of MEM that convert to valid addresses have already been
4036 handled by our scan of decls. The only special handling we
4037 need here is to make a copy of the rtx to ensure it isn't being
4038 shared if we have to change it to a pseudo.
4040 If the rtx is a simple reference to an address via a virtual register,
4041 it can potentially be shared. In such cases, first try to make it
4042 a valid address, which can also be shared. Otherwise, copy it and
4045 First check for common cases that need no processing. These are
4046 usually due to instantiation already being done on a previous instance
4050 if (CONSTANT_ADDRESS_P (temp)
4051 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
4052 || temp == arg_pointer_rtx
4054 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
4055 || temp == hard_frame_pointer_rtx
4057 || temp == frame_pointer_rtx)
4060 if (GET_CODE (temp) == PLUS
4061 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
4062 && (XEXP (temp, 0) == frame_pointer_rtx
4063 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
4064 || XEXP (temp, 0) == hard_frame_pointer_rtx
4066 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
4067 || XEXP (temp, 0) == arg_pointer_rtx
4072 if (temp == virtual_stack_vars_rtx
4073 || temp == virtual_incoming_args_rtx
4074 || (GET_CODE (temp) == PLUS
4075 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
4076 && (XEXP (temp, 0) == virtual_stack_vars_rtx
4077 || XEXP (temp, 0) == virtual_incoming_args_rtx)))
4079 /* This MEM may be shared. If the substitution can be done without
4080 the need to generate new pseudos, we want to do it in place
4081 so all copies of the shared rtx benefit. The call below will
4082 only make substitutions if the resulting address is still
4085 Note that we cannot pass X as the object in the recursive call
4086 since the insn being processed may not allow all valid
4087 addresses. However, if we were not passed on object, we can
4088 only modify X without copying it if X will have a valid
4091 ??? Also note that this can still lose if OBJECT is an insn that
4092 has less restrictions on an address that some other insn.
4093 In that case, we will modify the shared address. This case
4094 doesn't seem very likely, though. One case where this could
4095 happen is in the case of a USE or CLOBBER reference, but we
4096 take care of that below. */
4098 if (instantiate_virtual_regs_1 (&XEXP (x, 0),
4099 object ? object : x, 0))
4102 /* Otherwise make a copy and process that copy. We copy the entire
4103 RTL expression since it might be a PLUS which could also be
4105 *loc = x = copy_rtx (x);
4108 /* Fall through to generic unary operation case. */
4111 case STRICT_LOW_PART:
4113 case PRE_DEC: case PRE_INC: case POST_DEC: case POST_INC:
4114 case SIGN_EXTEND: case ZERO_EXTEND:
4115 case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE:
4116 case FLOAT: case FIX:
4117 case UNSIGNED_FIX: case UNSIGNED_FLOAT:
4122 case POPCOUNT: case PARITY:
4123 /* These case either have just one operand or we know that we need not
4124 check the rest of the operands. */
4130 /* If the operand is a MEM, see if the change is a valid MEM. If not,
4131 go ahead and make the invalid one, but do it to a copy. For a REG,
4132 just make the recursive call, since there's no chance of a problem. */
4134 if ((GET_CODE (XEXP (x, 0)) == MEM
4135 && instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 0), XEXP (x, 0),
4137 || (REG_P (XEXP (x, 0))
4138 && instantiate_virtual_regs_1 (&XEXP (x, 0), object, 0)))
4141 XEXP (x, 0) = copy_rtx (XEXP (x, 0));
4146 /* Try to replace with a PLUS. If that doesn't work, compute the sum
4147 in front of this insn and substitute the temporary. */
4148 if ((new = instantiate_new_reg (x, &offset)) != 0)
4150 temp = plus_constant (new, offset);
4151 if (!validate_change (object, loc, temp, 0))
4157 temp = force_operand (temp, NULL_RTX);
4161 emit_insn_before (seq, object);
4162 if (! validate_change (object, loc, temp, 0)
4163 && ! validate_replace_rtx (x, temp, object))
4164 instantiate_virtual_regs_lossage (object);
4171 if (REG_P (XEXP (x, 0)))
4174 else if (GET_CODE (XEXP (x, 0)) == MEM)
4176 /* If we have a (addressof (mem ..)), do any instantiation inside
4177 since we know we'll be making the inside valid when we finally
4178 remove the ADDRESSOF. */
4179 instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 0), NULL_RTX, 0);
4188 /* Scan all subexpressions. */
4189 fmt = GET_RTX_FORMAT (code);
4190 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
4193 if (!instantiate_virtual_regs_1 (&XEXP (x, i), object, extra_insns))
4196 else if (*fmt == 'E')
4197 for (j = 0; j < XVECLEN (x, i); j++)
4198 if (! instantiate_virtual_regs_1 (&XVECEXP (x, i, j), object,
4205 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
4206 This means a type for which function calls must pass an address to the
4207 function or get an address back from the function.
4208 EXP may be a type node or an expression (whose type is tested). */
4211 aggregate_value_p (tree exp, tree fntype)
4213 int i, regno, nregs;
4216 tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
4219 switch (TREE_CODE (fntype))
4222 fntype = get_callee_fndecl (fntype);
4223 fntype = fntype ? TREE_TYPE (fntype) : 0;
4226 fntype = TREE_TYPE (fntype);
4231 case IDENTIFIER_NODE:
4235 /* We don't expect other rtl types here. */
4239 if (TREE_CODE (type) == VOID_TYPE)
4241 if (targetm.calls.return_in_memory (type, fntype))
4243 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
4244 and thus can't be returned in registers. */
4245 if (TREE_ADDRESSABLE (type))
4247 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
4249 /* Make sure we have suitable call-clobbered regs to return
4250 the value in; if not, we must return it in memory. */
4251 reg = hard_function_value (type, 0, 0);
4253 /* If we have something other than a REG (e.g. a PARALLEL), then assume
4258 regno = REGNO (reg);
4259 nregs = hard_regno_nregs[regno][TYPE_MODE (type)];
4260 for (i = 0; i < nregs; i++)
4261 if (! call_used_regs[regno + i])
4266 /* Assign RTL expressions to the function's parameters.
4267 This may involve copying them into registers and using
4268 those registers as the RTL for them. */
4271 assign_parms (tree fndecl)
4274 CUMULATIVE_ARGS args_so_far;
4275 /* Total space needed so far for args on the stack,
4276 given as a constant and a tree-expression. */
4277 struct args_size stack_args_size;
4278 HOST_WIDE_INT extra_pretend_bytes = 0;
4279 tree fntype = TREE_TYPE (fndecl);
4280 tree fnargs = DECL_ARGUMENTS (fndecl), orig_fnargs;
4281 /* This is used for the arg pointer when referring to stack args. */
4282 rtx internal_arg_pointer;
4283 /* This is a dummy PARM_DECL that we used for the function result if
4284 the function returns a structure. */
4285 tree function_result_decl = 0;
4286 int varargs_setup = 0;
4287 int reg_parm_stack_space ATTRIBUTE_UNUSED = 0;
4288 rtx conversion_insns = 0;
4290 /* Nonzero if function takes extra anonymous args.
4291 This means the last named arg must be on the stack
4292 right before the anonymous ones. */
4293 int stdarg = current_function_stdarg;
4295 /* If the reg that the virtual arg pointer will be translated into is
4296 not a fixed reg or is the stack pointer, make a copy of the virtual
4297 arg pointer, and address parms via the copy. The frame pointer is
4298 considered fixed even though it is not marked as such.
4300 The second time through, simply use ap to avoid generating rtx. */
4302 if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
4303 || ! (fixed_regs[ARG_POINTER_REGNUM]
4304 || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
4305 internal_arg_pointer = copy_to_reg (virtual_incoming_args_rtx);
4307 internal_arg_pointer = virtual_incoming_args_rtx;
4308 current_function_internal_arg_pointer = internal_arg_pointer;
4310 stack_args_size.constant = 0;
4311 stack_args_size.var = 0;
4313 /* If struct value address is treated as the first argument, make it so. */
4314 if (aggregate_value_p (DECL_RESULT (fndecl), fndecl)
4315 && ! current_function_returns_pcc_struct
4316 && targetm.calls.struct_value_rtx (TREE_TYPE (fndecl), 1) == 0)
4318 tree type = build_pointer_type (TREE_TYPE (fntype));
4320 function_result_decl = build_decl (PARM_DECL, NULL_TREE, type);
4322 DECL_ARG_TYPE (function_result_decl) = type;
4323 TREE_CHAIN (function_result_decl) = fnargs;
4324 fnargs = function_result_decl;
4327 orig_fnargs = fnargs;
4329 max_parm_reg = LAST_VIRTUAL_REGISTER + 1;
4330 parm_reg_stack_loc = ggc_alloc_cleared (max_parm_reg * sizeof (rtx));
4332 /* If the target wants to split complex arguments into scalars, do so. */
4333 if (targetm.calls.split_complex_arg)
4334 fnargs = split_complex_args (fnargs);
4336 #ifdef REG_PARM_STACK_SPACE
4337 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
4340 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
4341 INIT_CUMULATIVE_INCOMING_ARGS (args_so_far, fntype, NULL_RTX);
4343 INIT_CUMULATIVE_ARGS (args_so_far, fntype, NULL_RTX, fndecl, -1);
4346 /* We haven't yet found an argument that we must push and pretend the
4348 current_function_pretend_args_size = 0;
4350 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
4354 enum machine_mode promoted_mode, passed_mode;
4355 enum machine_mode nominal_mode, promoted_nominal_mode;
4357 struct locate_and_pad_arg_data locate;
4358 int passed_pointer = 0;
4359 int did_conversion = 0;
4360 tree passed_type = DECL_ARG_TYPE (parm);
4361 tree nominal_type = TREE_TYPE (parm);
4362 int last_named = 0, named_arg;
4365 int pretend_bytes = 0;
4366 int loaded_in_reg = 0;
4368 /* Set LAST_NAMED if this is last named arg before last
4374 for (tem = TREE_CHAIN (parm); tem; tem = TREE_CHAIN (tem))
4375 if (DECL_NAME (tem))
4381 /* Set NAMED_ARG if this arg should be treated as a named arg. For
4382 most machines, if this is a varargs/stdarg function, then we treat
4383 the last named arg as if it were anonymous too. */
4384 named_arg = (targetm.calls.strict_argument_naming (&args_so_far)
4387 if (TREE_TYPE (parm) == error_mark_node
4388 /* This can happen after weird syntax errors
4389 or if an enum type is defined among the parms. */
4390 || TREE_CODE (parm) != PARM_DECL
4391 || passed_type == NULL)
4393 SET_DECL_RTL (parm, gen_rtx_MEM (BLKmode, const0_rtx));
4394 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
4395 TREE_USED (parm) = 1;
4399 /* Find mode of arg as it is passed, and mode of arg
4400 as it should be during execution of this function. */
4401 passed_mode = TYPE_MODE (passed_type);
4402 nominal_mode = TYPE_MODE (nominal_type);
4404 /* If the parm's mode is VOID, its value doesn't matter,
4405 and avoid the usual things like emit_move_insn that could crash. */
4406 if (nominal_mode == VOIDmode)
4408 SET_DECL_RTL (parm, const0_rtx);
4409 DECL_INCOMING_RTL (parm) = DECL_RTL (parm);
4413 /* If the parm is to be passed as a transparent union, use the
4414 type of the first field for the tests below. We have already
4415 verified that the modes are the same. */
4416 if (DECL_TRANSPARENT_UNION (parm)
4417 || (TREE_CODE (passed_type) == UNION_TYPE
4418 && TYPE_TRANSPARENT_UNION (passed_type)))
4419 passed_type = TREE_TYPE (TYPE_FIELDS (passed_type));
4421 /* See if this arg was passed by invisible reference. It is if
4422 it is an object whose size depends on the contents of the
4423 object itself or if the machine requires these objects be passed
4426 if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (passed_type))
4427 || TREE_ADDRESSABLE (passed_type)
4428 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
4429 || FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, passed_mode,
4430 passed_type, named_arg)
4434 passed_type = nominal_type = build_pointer_type (passed_type);
4436 passed_mode = nominal_mode = Pmode;
4438 /* See if the frontend wants to pass this by invisible reference. */
4439 else if (passed_type != nominal_type
4440 && POINTER_TYPE_P (passed_type)
4441 && TREE_TYPE (passed_type) == nominal_type)
4443 nominal_type = passed_type;
4445 passed_mode = nominal_mode = Pmode;
4448 promoted_mode = passed_mode;
4450 if (targetm.calls.promote_function_args (TREE_TYPE (fndecl)))
4452 /* Compute the mode in which the arg is actually extended to. */
4453 unsignedp = TYPE_UNSIGNED (passed_type);
4454 promoted_mode = promote_mode (passed_type, promoted_mode,
4458 /* Let machine desc say which reg (if any) the parm arrives in.
4459 0 means it arrives on the stack. */
4460 #ifdef FUNCTION_INCOMING_ARG
4461 entry_parm = FUNCTION_INCOMING_ARG (args_so_far, promoted_mode,
4462 passed_type, named_arg);
4464 entry_parm = FUNCTION_ARG (args_so_far, promoted_mode,
4465 passed_type, named_arg);
4468 if (entry_parm == 0)
4469 promoted_mode = passed_mode;
4471 /* If this is the last named parameter, do any required setup for
4472 varargs or stdargs. We need to know about the case of this being an
4473 addressable type, in which case we skip the registers it
4474 would have arrived in.
4476 For stdargs, LAST_NAMED will be set for two parameters, the one that
4477 is actually the last named, and the dummy parameter. We only
4478 want to do this action once.
4480 Also, indicate when RTL generation is to be suppressed. */
4481 if (last_named && !varargs_setup)
4483 int varargs_pretend_bytes = 0;
4484 targetm.calls.setup_incoming_varargs (&args_so_far, promoted_mode,
4486 &varargs_pretend_bytes, 0);
4489 /* If the back-end has requested extra stack space, record how
4490 much is needed. Do not change pretend_args_size otherwise
4491 since it may be nonzero from an earlier partial argument. */
4492 if (varargs_pretend_bytes > 0)
4493 current_function_pretend_args_size = varargs_pretend_bytes;
4496 /* Determine parm's home in the stack,
4497 in case it arrives in the stack or we should pretend it did.
4499 Compute the stack position and rtx where the argument arrives
4502 There is one complexity here: If this was a parameter that would
4503 have been passed in registers, but wasn't only because it is
4504 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
4505 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
4506 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of
4507 0 as it was the previous time. */
4508 in_regs = entry_parm != 0;
4509 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4512 if (!in_regs && !named_arg)
4515 targetm.calls.pretend_outgoing_varargs_named (&args_so_far);
4518 #ifdef FUNCTION_INCOMING_ARG
4519 in_regs = FUNCTION_INCOMING_ARG (args_so_far, promoted_mode,
4521 pretend_named) != 0;
4523 in_regs = FUNCTION_ARG (args_so_far, promoted_mode,
4525 pretend_named) != 0;
4530 /* If this parameter was passed both in registers and in the stack,
4531 use the copy on the stack. */
4532 if (MUST_PASS_IN_STACK (promoted_mode, passed_type))
4535 #ifdef FUNCTION_ARG_PARTIAL_NREGS
4538 partial = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, promoted_mode,
4539 passed_type, named_arg);
4541 /* The caller might already have allocated stack space
4542 for the register parameters. */
4543 && reg_parm_stack_space == 0)
4545 /* Part of this argument is passed in registers and part
4546 is passed on the stack. Ask the prologue code to extend
4547 the stack part so that we can recreate the full value.
4549 PRETEND_BYTES is the size of the registers we need to store.
4550 CURRENT_FUNCTION_PRETEND_ARGS_SIZE is the amount of extra
4551 stack space that the prologue should allocate.
4553 Internally, gcc assumes that the argument pointer is
4554 aligned to STACK_BOUNDARY bits. This is used both for
4555 alignment optimizations (see init_emit) and to locate
4556 arguments that are aligned to more than PARM_BOUNDARY
4557 bits. We must preserve this invariant by rounding
4558 CURRENT_FUNCTION_PRETEND_ARGS_SIZE up to a stack
4561 /* We assume at most one partial arg, and it must be the first
4562 argument on the stack. */
4563 if (extra_pretend_bytes || current_function_pretend_args_size)
4566 pretend_bytes = partial * UNITS_PER_WORD;
4567 current_function_pretend_args_size
4568 = CEIL_ROUND (pretend_bytes, STACK_BYTES);
4570 /* We want to align relative to the actual stack pointer, so
4571 don't include this in the stack size until later. */
4572 extra_pretend_bytes = current_function_pretend_args_size;
4577 memset (&locate, 0, sizeof (locate));
4578 locate_and_pad_parm (promoted_mode, passed_type, in_regs,
4579 entry_parm ? partial : 0, fndecl,
4580 &stack_args_size, &locate);
4581 /* Adjust offsets to include the pretend args. */
4582 locate.slot_offset.constant += extra_pretend_bytes - pretend_bytes;
4583 locate.offset.constant += extra_pretend_bytes - pretend_bytes;
4587 unsigned int align, boundary;
4589 /* If we're passing this arg using a reg, make its stack home
4590 the aligned stack slot. */
4592 offset_rtx = ARGS_SIZE_RTX (locate.slot_offset);
4594 offset_rtx = ARGS_SIZE_RTX (locate.offset);
4596 if (offset_rtx == const0_rtx)
4597 stack_parm = gen_rtx_MEM (promoted_mode, internal_arg_pointer);
4599 stack_parm = gen_rtx_MEM (promoted_mode,
4600 gen_rtx_PLUS (Pmode,
4601 internal_arg_pointer,
4604 set_mem_attributes (stack_parm, parm, 1);
4606 boundary = FUNCTION_ARG_BOUNDARY (promoted_mode, passed_type);
4609 /* If we're padding upward, we know that the alignment of the slot
4610 is FUNCTION_ARG_BOUNDARY. If we're using slot_offset, we're
4611 intentionally forcing upward padding. Otherwise we have to come
4612 up with a guess at the alignment based on OFFSET_RTX. */
4613 if (locate.where_pad == upward || entry_parm)
4615 else if (GET_CODE (offset_rtx) == CONST_INT)
4617 align = INTVAL (offset_rtx) * BITS_PER_UNIT | boundary;
4618 align = align & -align;
4621 set_mem_align (stack_parm, align);
4624 set_reg_attrs_for_parm (entry_parm, stack_parm);
4627 /* If this parm was passed part in regs and part in memory,
4628 pretend it arrived entirely in memory
4629 by pushing the register-part onto the stack.
4631 In the special case of a DImode or DFmode that is split,
4632 we could put it together in a pseudoreg directly,
4633 but for now that's not worth bothering with. */
4637 /* Handle calls that pass values in multiple non-contiguous
4638 locations. The Irix 6 ABI has examples of this. */
4639 if (GET_CODE (entry_parm) == PARALLEL)
4640 emit_group_store (validize_mem (stack_parm), entry_parm,
4642 int_size_in_bytes (TREE_TYPE (parm)));
4645 move_block_from_reg (REGNO (entry_parm), validize_mem (stack_parm),
4648 entry_parm = stack_parm;
4651 /* If we didn't decide this parm came in a register,
4652 by default it came on the stack. */
4653 if (entry_parm == 0)
4654 entry_parm = stack_parm;
4656 /* Record permanently how this parm was passed. */
4657 set_decl_incoming_rtl (parm, entry_parm);
4659 /* If there is actually space on the stack for this parm,
4660 count it in stack_args_size; otherwise set stack_parm to 0
4661 to indicate there is no preallocated stack slot for the parm. */
4663 if (entry_parm == stack_parm
4664 || (GET_CODE (entry_parm) == PARALLEL
4665 && XEXP (XVECEXP (entry_parm, 0, 0), 0) == NULL_RTX)
4666 #if defined (REG_PARM_STACK_SPACE)
4667 /* On some machines, even if a parm value arrives in a register
4668 there is still an (uninitialized) stack slot allocated
4670 || REG_PARM_STACK_SPACE (fndecl) > 0
4674 stack_args_size.constant += locate.size.constant;
4675 if (locate.size.var)
4676 ADD_PARM_SIZE (stack_args_size, locate.size.var);
4679 /* No stack slot was pushed for this parm. */
4682 /* Update info on where next arg arrives in registers. */
4684 FUNCTION_ARG_ADVANCE (args_so_far, promoted_mode,
4685 passed_type, named_arg);
4687 /* If we can't trust the parm stack slot to be aligned enough
4688 for its ultimate type, don't use that slot after entry.
4689 We'll make another stack slot, if we need one. */
4690 if (STRICT_ALIGNMENT && stack_parm
4691 && GET_MODE_ALIGNMENT (nominal_mode) > MEM_ALIGN (stack_parm))
4694 /* If parm was passed in memory, and we need to convert it on entry,
4695 don't store it back in that same slot. */
4696 if (entry_parm == stack_parm
4697 && nominal_mode != BLKmode && nominal_mode != passed_mode)
4700 /* When an argument is passed in multiple locations, we can't
4701 make use of this information, but we can save some copying if
4702 the whole argument is passed in a single register. */
4703 if (GET_CODE (entry_parm) == PARALLEL
4704 && nominal_mode != BLKmode && passed_mode != BLKmode)
4706 int i, len = XVECLEN (entry_parm, 0);
4708 for (i = 0; i < len; i++)
4709 if (XEXP (XVECEXP (entry_parm, 0, i), 0) != NULL_RTX
4710 && REG_P (XEXP (XVECEXP (entry_parm, 0, i), 0))
4711 && (GET_MODE (XEXP (XVECEXP (entry_parm, 0, i), 0))
4713 && INTVAL (XEXP (XVECEXP (entry_parm, 0, i), 1)) == 0)
4715 entry_parm = XEXP (XVECEXP (entry_parm, 0, i), 0);
4716 set_decl_incoming_rtl (parm, entry_parm);
4721 /* ENTRY_PARM is an RTX for the parameter as it arrives,
4722 in the mode in which it arrives.
4723 STACK_PARM is an RTX for a stack slot where the parameter can live
4724 during the function (in case we want to put it there).
4725 STACK_PARM is 0 if no stack slot was pushed for it.
4727 Now output code if necessary to convert ENTRY_PARM to
4728 the type in which this function declares it,
4729 and store that result in an appropriate place,
4730 which may be a pseudo reg, may be STACK_PARM,
4731 or may be a local stack slot if STACK_PARM is 0.
4733 Set DECL_RTL to that place. */
4735 if (GET_CODE (entry_parm) == PARALLEL && nominal_mode != BLKmode
4736 && XVECLEN (entry_parm, 0) > 1)
4738 /* Reconstitute objects the size of a register or larger using
4739 register operations instead of the stack. */
4740 rtx parmreg = gen_reg_rtx (nominal_mode);
4742 if (REG_P (parmreg))
4744 unsigned int regno = REGNO (parmreg);
4746 emit_group_store (parmreg, entry_parm, TREE_TYPE (parm),
4747 int_size_in_bytes (TREE_TYPE (parm)));
4748 SET_DECL_RTL (parm, parmreg);
4751 if (regno >= max_parm_reg)
4754 int old_max_parm_reg = max_parm_reg;
4756 /* It's slow to expand this one register at a time,
4757 but it's also rare and we need max_parm_reg to be
4758 precisely correct. */
4759 max_parm_reg = regno + 1;
4760 new = ggc_realloc (parm_reg_stack_loc,
4761 max_parm_reg * sizeof (rtx));
4762 memset (new + old_max_parm_reg, 0,
4763 (max_parm_reg - old_max_parm_reg) * sizeof (rtx));
4764 parm_reg_stack_loc = new;
4765 parm_reg_stack_loc[regno] = stack_parm;
4770 if (nominal_mode == BLKmode
4771 #ifdef BLOCK_REG_PADDING
4772 || (locate.where_pad == (BYTES_BIG_ENDIAN ? upward : downward)
4773 && GET_MODE_SIZE (promoted_mode) < UNITS_PER_WORD)
4775 || GET_CODE (entry_parm) == PARALLEL)
4777 /* If a BLKmode arrives in registers, copy it to a stack slot.
4778 Handle calls that pass values in multiple non-contiguous
4779 locations. The Irix 6 ABI has examples of this. */
4780 if (REG_P (entry_parm)
4781 || (GET_CODE (entry_parm) == PARALLEL
4782 && (!loaded_in_reg || !optimize)))
4784 int size = int_size_in_bytes (TREE_TYPE (parm));
4785 int size_stored = CEIL_ROUND (size, UNITS_PER_WORD);
4788 /* Note that we will be storing an integral number of words.
4789 So we have to be careful to ensure that we allocate an
4790 integral number of words. We do this below in the
4791 assign_stack_local if space was not allocated in the argument
4792 list. If it was, this will not work if PARM_BOUNDARY is not
4793 a multiple of BITS_PER_WORD. It isn't clear how to fix this
4794 if it becomes a problem. Exception is when BLKmode arrives
4795 with arguments not conforming to word_mode. */
4797 if (stack_parm == 0)
4799 stack_parm = assign_stack_local (BLKmode, size_stored, 0);
4800 PUT_MODE (stack_parm, GET_MODE (entry_parm));
4801 set_mem_attributes (stack_parm, parm, 1);
4803 else if (GET_CODE (entry_parm) == PARALLEL)
4805 else if (size != 0 && PARM_BOUNDARY % BITS_PER_WORD != 0)
4808 mem = validize_mem (stack_parm);
4810 /* Handle calls that pass values in multiple non-contiguous
4811 locations. The Irix 6 ABI has examples of this. */
4812 if (GET_CODE (entry_parm) == PARALLEL)
4813 emit_group_store (mem, entry_parm, TREE_TYPE (parm), size);
4818 /* If SIZE is that of a mode no bigger than a word, just use
4819 that mode's store operation. */
4820 else if (size <= UNITS_PER_WORD)
4822 enum machine_mode mode
4823 = mode_for_size (size * BITS_PER_UNIT, MODE_INT, 0);
4826 #ifdef BLOCK_REG_PADDING
4827 && (size == UNITS_PER_WORD
4828 || (BLOCK_REG_PADDING (mode, TREE_TYPE (parm), 1)
4829 != (BYTES_BIG_ENDIAN ? upward : downward)))
4833 rtx reg = gen_rtx_REG (mode, REGNO (entry_parm));
4834 emit_move_insn (change_address (mem, mode, 0), reg);
4837 /* Blocks smaller than a word on a BYTES_BIG_ENDIAN
4838 machine must be aligned to the left before storing
4839 to memory. Note that the previous test doesn't
4840 handle all cases (e.g. SIZE == 3). */
4841 else if (size != UNITS_PER_WORD
4842 #ifdef BLOCK_REG_PADDING
4843 && (BLOCK_REG_PADDING (mode, TREE_TYPE (parm), 1)
4851 int by = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
4852 rtx reg = gen_rtx_REG (word_mode, REGNO (entry_parm));
4854 x = expand_binop (word_mode, ashl_optab, reg,
4855 GEN_INT (by), 0, 1, OPTAB_WIDEN);
4856 tem = change_address (mem, word_mode, 0);
4857 emit_move_insn (tem, x);
4860 move_block_from_reg (REGNO (entry_parm), mem,
4861 size_stored / UNITS_PER_WORD);
4864 move_block_from_reg (REGNO (entry_parm), mem,
4865 size_stored / UNITS_PER_WORD);
4867 /* If parm is already bound to register pair, don't change
4869 if (! DECL_RTL_SET_P (parm))
4870 SET_DECL_RTL (parm, stack_parm);
4872 else if (! ((! optimize
4873 && ! DECL_REGISTER (parm))
4874 || TREE_SIDE_EFFECTS (parm)
4875 /* If -ffloat-store specified, don't put explicit
4876 float variables into registers. */
4877 || (flag_float_store
4878 && TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE))
4879 /* Always assign pseudo to structure return or item passed
4880 by invisible reference. */
4881 || passed_pointer || parm == function_result_decl)
4883 /* Store the parm in a pseudoregister during the function, but we
4884 may need to do it in a wider mode. */
4887 unsigned int regno, regnoi = 0, regnor = 0;
4889 unsignedp = TYPE_UNSIGNED (TREE_TYPE (parm));
4891 promoted_nominal_mode
4892 = promote_mode (TREE_TYPE (parm), nominal_mode, &unsignedp, 0);
4894 parmreg = gen_reg_rtx (promoted_nominal_mode);
4895 mark_user_reg (parmreg);
4897 /* If this was an item that we received a pointer to, set DECL_RTL
4901 rtx x = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (passed_type)),
4903 set_mem_attributes (x, parm, 1);
4904 SET_DECL_RTL (parm, x);
4908 SET_DECL_RTL (parm, parmreg);
4909 maybe_set_unchanging (DECL_RTL (parm), parm);
4912 /* Copy the value into the register. */
4913 if (nominal_mode != passed_mode
4914 || promoted_nominal_mode != promoted_mode)
4917 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
4918 mode, by the caller. We now have to convert it to
4919 NOMINAL_MODE, if different. However, PARMREG may be in
4920 a different mode than NOMINAL_MODE if it is being stored
4923 If ENTRY_PARM is a hard register, it might be in a register
4924 not valid for operating in its mode (e.g., an odd-numbered
4925 register for a DFmode). In that case, moves are the only
4926 thing valid, so we can't do a convert from there. This
4927 occurs when the calling sequence allow such misaligned
4930 In addition, the conversion may involve a call, which could
4931 clobber parameters which haven't been copied to pseudo
4932 registers yet. Therefore, we must first copy the parm to
4933 a pseudo reg here, and save the conversion until after all
4934 parameters have been moved. */
4936 rtx tempreg = gen_reg_rtx (GET_MODE (entry_parm));
4938 emit_move_insn (tempreg, validize_mem (entry_parm));
4940 push_to_sequence (conversion_insns);
4941 tempreg = convert_to_mode (nominal_mode, tempreg, unsignedp);
4943 if (GET_CODE (tempreg) == SUBREG
4944 && GET_MODE (tempreg) == nominal_mode
4945 && REG_P (SUBREG_REG (tempreg))
4946 && nominal_mode == passed_mode
4947 && GET_MODE (SUBREG_REG (tempreg)) == GET_MODE (entry_parm)
4948 && GET_MODE_SIZE (GET_MODE (tempreg))
4949 < GET_MODE_SIZE (GET_MODE (entry_parm)))
4951 /* The argument is already sign/zero extended, so note it
4953 SUBREG_PROMOTED_VAR_P (tempreg) = 1;
4954 SUBREG_PROMOTED_UNSIGNED_SET (tempreg, unsignedp);
4957 /* TREE_USED gets set erroneously during expand_assignment. */
4958 save_tree_used = TREE_USED (parm);
4959 expand_assignment (parm,
4960 make_tree (nominal_type, tempreg), 0);
4961 TREE_USED (parm) = save_tree_used;
4962 conversion_insns = get_insns ();
4967 emit_move_insn (parmreg, validize_mem (entry_parm));
4969 /* If we were passed a pointer but the actual value
4970 can safely live in a register, put it in one. */
4971 if (passed_pointer && TYPE_MODE (TREE_TYPE (parm)) != BLKmode
4972 /* If by-reference argument was promoted, demote it. */
4973 && (TYPE_MODE (TREE_TYPE (parm)) != GET_MODE (DECL_RTL (parm))
4975 && ! DECL_REGISTER (parm))
4976 || TREE_SIDE_EFFECTS (parm)
4977 /* If -ffloat-store specified, don't put explicit
4978 float variables into registers. */
4979 || (flag_float_store
4980 && TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE))))
4982 /* We can't use nominal_mode, because it will have been set to
4983 Pmode above. We must use the actual mode of the parm. */
4984 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
4985 mark_user_reg (parmreg);
4986 if (GET_MODE (parmreg) != GET_MODE (DECL_RTL (parm)))
4988 rtx tempreg = gen_reg_rtx (GET_MODE (DECL_RTL (parm)));
4989 int unsigned_p = TYPE_UNSIGNED (TREE_TYPE (parm));
4990 push_to_sequence (conversion_insns);
4991 emit_move_insn (tempreg, DECL_RTL (parm));
4993 convert_to_mode (GET_MODE (parmreg),
4996 emit_move_insn (parmreg, DECL_RTL (parm));
4997 conversion_insns = get_insns();
5002 emit_move_insn (parmreg, DECL_RTL (parm));
5003 SET_DECL_RTL (parm, parmreg);
5004 /* STACK_PARM is the pointer, not the parm, and PARMREG is
5008 #ifdef FUNCTION_ARG_CALLEE_COPIES
5009 /* If we are passed an arg by reference and it is our responsibility
5010 to make a copy, do it now.
5011 PASSED_TYPE and PASSED mode now refer to the pointer, not the
5012 original argument, so we must recreate them in the call to
5013 FUNCTION_ARG_CALLEE_COPIES. */
5014 /* ??? Later add code to handle the case that if the argument isn't
5015 modified, don't do the copy. */
5017 else if (passed_pointer
5018 && FUNCTION_ARG_CALLEE_COPIES (args_so_far,
5019 TYPE_MODE (TREE_TYPE (passed_type)),
5020 TREE_TYPE (passed_type),
5022 && ! TREE_ADDRESSABLE (TREE_TYPE (passed_type)))
5025 tree type = TREE_TYPE (passed_type);
5027 /* This sequence may involve a library call perhaps clobbering
5028 registers that haven't been copied to pseudos yet. */
5030 push_to_sequence (conversion_insns);
5032 if (!COMPLETE_TYPE_P (type)
5033 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
5034 /* This is a variable sized object. */
5035 copy = gen_rtx_MEM (BLKmode,
5036 allocate_dynamic_stack_space
5037 (expr_size (parm), NULL_RTX,
5038 TYPE_ALIGN (type)));
5040 copy = assign_stack_temp (TYPE_MODE (type),
5041 int_size_in_bytes (type), 1);
5042 set_mem_attributes (copy, parm, 1);
5044 store_expr (parm, copy, 0);
5045 emit_move_insn (parmreg, XEXP (copy, 0));
5046 conversion_insns = get_insns ();
5050 #endif /* FUNCTION_ARG_CALLEE_COPIES */
5052 /* In any case, record the parm's desired stack location
5053 in case we later discover it must live in the stack.
5055 If it is a COMPLEX value, store the stack location for both
5058 if (GET_CODE (parmreg) == CONCAT)
5059 regno = MAX (REGNO (XEXP (parmreg, 0)), REGNO (XEXP (parmreg, 1)));
5061 regno = REGNO (parmreg);
5063 if (regno >= max_parm_reg)
5066 int old_max_parm_reg = max_parm_reg;
5068 /* It's slow to expand this one register at a time,
5069 but it's also rare and we need max_parm_reg to be
5070 precisely correct. */
5071 max_parm_reg = regno + 1;
5072 new = ggc_realloc (parm_reg_stack_loc,
5073 max_parm_reg * sizeof (rtx));
5074 memset (new + old_max_parm_reg, 0,
5075 (max_parm_reg - old_max_parm_reg) * sizeof (rtx));
5076 parm_reg_stack_loc = new;
5079 if (GET_CODE (parmreg) == CONCAT)
5081 enum machine_mode submode = GET_MODE (XEXP (parmreg, 0));
5083 regnor = REGNO (gen_realpart (submode, parmreg));
5084 regnoi = REGNO (gen_imagpart (submode, parmreg));
5086 if (stack_parm != 0)
5088 parm_reg_stack_loc[regnor]
5089 = gen_realpart (submode, stack_parm);
5090 parm_reg_stack_loc[regnoi]
5091 = gen_imagpart (submode, stack_parm);
5095 parm_reg_stack_loc[regnor] = 0;
5096 parm_reg_stack_loc[regnoi] = 0;
5100 parm_reg_stack_loc[REGNO (parmreg)] = stack_parm;
5102 /* Mark the register as eliminable if we did no conversion
5103 and it was copied from memory at a fixed offset,
5104 and the arg pointer was not copied to a pseudo-reg.
5105 If the arg pointer is a pseudo reg or the offset formed
5106 an invalid address, such memory-equivalences
5107 as we make here would screw up life analysis for it. */
5108 if (nominal_mode == passed_mode
5111 && GET_CODE (stack_parm) == MEM
5112 && locate.offset.var == 0
5113 && reg_mentioned_p (virtual_incoming_args_rtx,
5114 XEXP (stack_parm, 0)))
5116 rtx linsn = get_last_insn ();
5119 /* Mark complex types separately. */
5120 if (GET_CODE (parmreg) == CONCAT)
5121 /* Scan backwards for the set of the real and
5123 for (sinsn = linsn; sinsn != 0;
5124 sinsn = prev_nonnote_insn (sinsn))
5126 set = single_set (sinsn);
5128 && SET_DEST (set) == regno_reg_rtx [regnoi])
5130 = gen_rtx_EXPR_LIST (REG_EQUIV,
5131 parm_reg_stack_loc[regnoi],
5134 && SET_DEST (set) == regno_reg_rtx [regnor])
5136 = gen_rtx_EXPR_LIST (REG_EQUIV,
5137 parm_reg_stack_loc[regnor],
5140 else if ((set = single_set (linsn)) != 0
5141 && SET_DEST (set) == parmreg)
5143 = gen_rtx_EXPR_LIST (REG_EQUIV,
5144 stack_parm, REG_NOTES (linsn));
5147 /* For pointer data type, suggest pointer register. */
5148 if (POINTER_TYPE_P (TREE_TYPE (parm)))
5149 mark_reg_pointer (parmreg,
5150 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
5152 /* If something wants our address, try to use ADDRESSOF. */
5153 if (TREE_ADDRESSABLE (parm))
5155 /* If we end up putting something into the stack,
5156 fixup_var_refs_insns will need to make a pass over
5157 all the instructions. It looks through the pending
5158 sequences -- but it can't see the ones in the
5159 CONVERSION_INSNS, if they're not on the sequence
5160 stack. So, we go back to that sequence, just so that
5161 the fixups will happen. */
5162 push_to_sequence (conversion_insns);
5163 put_var_into_stack (parm, /*rescan=*/true);
5164 conversion_insns = get_insns ();
5170 /* Value must be stored in the stack slot STACK_PARM
5171 during function execution. */
5173 if (promoted_mode != nominal_mode)
5175 /* Conversion is required. */
5176 rtx tempreg = gen_reg_rtx (GET_MODE (entry_parm));
5178 emit_move_insn (tempreg, validize_mem (entry_parm));
5180 push_to_sequence (conversion_insns);
5181 entry_parm = convert_to_mode (nominal_mode, tempreg,
5182 TYPE_UNSIGNED (TREE_TYPE (parm)));
5184 /* ??? This may need a big-endian conversion on sparc64. */
5185 stack_parm = adjust_address (stack_parm, nominal_mode, 0);
5187 conversion_insns = get_insns ();
5192 if (entry_parm != stack_parm)
5194 if (stack_parm == 0)
5197 = assign_stack_local (GET_MODE (entry_parm),
5198 GET_MODE_SIZE (GET_MODE (entry_parm)),
5200 set_mem_attributes (stack_parm, parm, 1);
5203 if (promoted_mode != nominal_mode)
5205 push_to_sequence (conversion_insns);
5206 emit_move_insn (validize_mem (stack_parm),
5207 validize_mem (entry_parm));
5208 conversion_insns = get_insns ();
5212 emit_move_insn (validize_mem (stack_parm),
5213 validize_mem (entry_parm));
5216 SET_DECL_RTL (parm, stack_parm);
5220 if (targetm.calls.split_complex_arg && fnargs != orig_fnargs)
5222 for (parm = orig_fnargs; parm; parm = TREE_CHAIN (parm))
5224 if (TREE_CODE (TREE_TYPE (parm)) == COMPLEX_TYPE
5225 && targetm.calls.split_complex_arg (TREE_TYPE (parm)))
5227 rtx tmp, real, imag;
5228 enum machine_mode inner = GET_MODE_INNER (DECL_MODE (parm));
5230 real = DECL_RTL (fnargs);
5231 imag = DECL_RTL (TREE_CHAIN (fnargs));
5232 if (inner != GET_MODE (real))
5234 real = gen_lowpart_SUBREG (inner, real);
5235 imag = gen_lowpart_SUBREG (inner, imag);
5237 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
5238 SET_DECL_RTL (parm, tmp);
5240 real = DECL_INCOMING_RTL (fnargs);
5241 imag = DECL_INCOMING_RTL (TREE_CHAIN (fnargs));
5242 if (inner != GET_MODE (real))
5244 real = gen_lowpart_SUBREG (inner, real);
5245 imag = gen_lowpart_SUBREG (inner, imag);
5247 tmp = gen_rtx_CONCAT (DECL_MODE (parm), real, imag);
5248 set_decl_incoming_rtl (parm, tmp);
5249 fnargs = TREE_CHAIN (fnargs);
5253 SET_DECL_RTL (parm, DECL_RTL (fnargs));
5254 set_decl_incoming_rtl (parm, DECL_INCOMING_RTL (fnargs));
5256 /* Set MEM_EXPR to the original decl, i.e. to PARM,
5257 instead of the copy of decl, i.e. FNARGS. */
5258 if (DECL_INCOMING_RTL (parm)
5259 && GET_CODE (DECL_INCOMING_RTL (parm)) == MEM)
5260 set_mem_expr (DECL_INCOMING_RTL (parm), parm);
5262 fnargs = TREE_CHAIN (fnargs);
5266 /* Output all parameter conversion instructions (possibly including calls)
5267 now that all parameters have been copied out of hard registers. */
5268 emit_insn (conversion_insns);
5270 /* If we are receiving a struct value address as the first argument, set up
5271 the RTL for the function result. As this might require code to convert
5272 the transmitted address to Pmode, we do this here to ensure that possible
5273 preliminary conversions of the address have been emitted already. */
5274 if (function_result_decl)
5276 tree result = DECL_RESULT (fndecl);
5277 rtx addr = DECL_RTL (function_result_decl);
5280 addr = convert_memory_address (Pmode, addr);
5281 x = gen_rtx_MEM (DECL_MODE (result), addr);
5282 set_mem_attributes (x, result, 1);
5283 SET_DECL_RTL (result, x);
5286 /* We have aligned all the args, so add space for the pretend args. */
5287 stack_args_size.constant += extra_pretend_bytes;
5288 current_function_args_size = stack_args_size.constant;
5290 /* Adjust function incoming argument size for alignment and
5293 #ifdef REG_PARM_STACK_SPACE
5294 current_function_args_size = MAX (current_function_args_size,
5295 REG_PARM_STACK_SPACE (fndecl));
5298 current_function_args_size
5299 = ((current_function_args_size + STACK_BYTES - 1)
5300 / STACK_BYTES) * STACK_BYTES;
5302 #ifdef ARGS_GROW_DOWNWARD
5303 current_function_arg_offset_rtx
5304 = (stack_args_size.var == 0 ? GEN_INT (-stack_args_size.constant)
5305 : expand_expr (size_diffop (stack_args_size.var,
5306 size_int (-stack_args_size.constant)),
5307 NULL_RTX, VOIDmode, 0));
5309 current_function_arg_offset_rtx = ARGS_SIZE_RTX (stack_args_size);
5312 /* See how many bytes, if any, of its args a function should try to pop
5315 current_function_pops_args = RETURN_POPS_ARGS (fndecl, TREE_TYPE (fndecl),
5316 current_function_args_size);
5318 /* For stdarg.h function, save info about
5319 regs and stack space used by the named args. */
5321 current_function_args_info = args_so_far;
5323 /* Set the rtx used for the function return value. Put this in its
5324 own variable so any optimizers that need this information don't have
5325 to include tree.h. Do this here so it gets done when an inlined
5326 function gets output. */
5328 current_function_return_rtx
5329 = (DECL_RTL_SET_P (DECL_RESULT (fndecl))
5330 ? DECL_RTL (DECL_RESULT (fndecl)) : NULL_RTX);
5332 /* If scalar return value was computed in a pseudo-reg, or was a named
5333 return value that got dumped to the stack, copy that to the hard
5335 if (DECL_RTL_SET_P (DECL_RESULT (fndecl)))
5337 tree decl_result = DECL_RESULT (fndecl);
5338 rtx decl_rtl = DECL_RTL (decl_result);
5340 if (REG_P (decl_rtl)
5341 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
5342 : DECL_REGISTER (decl_result))
5346 #ifdef FUNCTION_OUTGOING_VALUE
5347 real_decl_rtl = FUNCTION_OUTGOING_VALUE (TREE_TYPE (decl_result),
5350 real_decl_rtl = FUNCTION_VALUE (TREE_TYPE (decl_result),
5353 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
5354 /* The delay slot scheduler assumes that current_function_return_rtx
5355 holds the hard register containing the return value, not a
5356 temporary pseudo. */
5357 current_function_return_rtx = real_decl_rtl;
5362 /* If ARGS contains entries with complex types, split the entry into two
5363 entries of the component type. Return a new list of substitutions are
5364 needed, else the old list. */
5367 split_complex_args (tree args)
5371 /* Before allocating memory, check for the common case of no complex. */
5372 for (p = args; p; p = TREE_CHAIN (p))
5374 tree type = TREE_TYPE (p);
5375 if (TREE_CODE (type) == COMPLEX_TYPE
5376 && targetm.calls.split_complex_arg (type))
5382 args = copy_list (args);
5384 for (p = args; p; p = TREE_CHAIN (p))
5386 tree type = TREE_TYPE (p);
5387 if (TREE_CODE (type) == COMPLEX_TYPE
5388 && targetm.calls.split_complex_arg (type))
5391 tree subtype = TREE_TYPE (type);
5393 /* Rewrite the PARM_DECL's type with its component. */
5394 TREE_TYPE (p) = subtype;
5395 DECL_ARG_TYPE (p) = TREE_TYPE (DECL_ARG_TYPE (p));
5396 DECL_MODE (p) = VOIDmode;
5397 DECL_SIZE (p) = NULL;
5398 DECL_SIZE_UNIT (p) = NULL;
5401 /* Build a second synthetic decl. */
5402 decl = build_decl (PARM_DECL, NULL_TREE, subtype);
5403 DECL_ARG_TYPE (decl) = DECL_ARG_TYPE (p);
5404 layout_decl (decl, 0);
5406 /* Splice it in; skip the new decl. */
5407 TREE_CHAIN (decl) = TREE_CHAIN (p);
5408 TREE_CHAIN (p) = decl;
5416 /* Indicate whether REGNO is an incoming argument to the current function
5417 that was promoted to a wider mode. If so, return the RTX for the
5418 register (to get its mode). PMODE and PUNSIGNEDP are set to the mode
5419 that REGNO is promoted from and whether the promotion was signed or
5423 promoted_input_arg (unsigned int regno, enum machine_mode *pmode, int *punsignedp)
5427 for (arg = DECL_ARGUMENTS (current_function_decl); arg;
5428 arg = TREE_CHAIN (arg))
5429 if (REG_P (DECL_INCOMING_RTL (arg))
5430 && REGNO (DECL_INCOMING_RTL (arg)) == regno
5431 && TYPE_MODE (DECL_ARG_TYPE (arg)) == TYPE_MODE (TREE_TYPE (arg)))
5433 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg));
5434 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (arg));
5436 mode = promote_mode (TREE_TYPE (arg), mode, &unsignedp, 1);
5437 if (mode == GET_MODE (DECL_INCOMING_RTL (arg))
5438 && mode != DECL_MODE (arg))
5440 *pmode = DECL_MODE (arg);
5441 *punsignedp = unsignedp;
5442 return DECL_INCOMING_RTL (arg);
5450 /* Compute the size and offset from the start of the stacked arguments for a
5451 parm passed in mode PASSED_MODE and with type TYPE.
5453 INITIAL_OFFSET_PTR points to the current offset into the stacked
5456 The starting offset and size for this parm are returned in
5457 LOCATE->OFFSET and LOCATE->SIZE, respectively. When IN_REGS is
5458 nonzero, the offset is that of stack slot, which is returned in
5459 LOCATE->SLOT_OFFSET. LOCATE->ALIGNMENT_PAD is the amount of
5460 padding required from the initial offset ptr to the stack slot.
5462 IN_REGS is nonzero if the argument will be passed in registers. It will
5463 never be set if REG_PARM_STACK_SPACE is not defined.
5465 FNDECL is the function in which the argument was defined.
5467 There are two types of rounding that are done. The first, controlled by
5468 FUNCTION_ARG_BOUNDARY, forces the offset from the start of the argument
5469 list to be aligned to the specific boundary (in bits). This rounding
5470 affects the initial and starting offsets, but not the argument size.
5472 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
5473 optionally rounds the size of the parm to PARM_BOUNDARY. The
5474 initial offset is not affected by this rounding, while the size always
5475 is and the starting offset may be. */
5477 /* LOCATE->OFFSET will be negative for ARGS_GROW_DOWNWARD case;
5478 INITIAL_OFFSET_PTR is positive because locate_and_pad_parm's
5479 callers pass in the total size of args so far as
5480 INITIAL_OFFSET_PTR. LOCATE->SIZE is always positive. */
5483 locate_and_pad_parm (enum machine_mode passed_mode, tree type, int in_regs,
5484 int partial, tree fndecl ATTRIBUTE_UNUSED,
5485 struct args_size *initial_offset_ptr,
5486 struct locate_and_pad_arg_data *locate)
5489 enum direction where_pad;
5491 int reg_parm_stack_space = 0;
5492 int part_size_in_regs;
5494 #ifdef REG_PARM_STACK_SPACE
5495 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
5497 /* If we have found a stack parm before we reach the end of the
5498 area reserved for registers, skip that area. */
5501 if (reg_parm_stack_space > 0)
5503 if (initial_offset_ptr->var)
5505 initial_offset_ptr->var
5506 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
5507 ssize_int (reg_parm_stack_space));
5508 initial_offset_ptr->constant = 0;
5510 else if (initial_offset_ptr->constant < reg_parm_stack_space)
5511 initial_offset_ptr->constant = reg_parm_stack_space;
5514 #endif /* REG_PARM_STACK_SPACE */
5516 part_size_in_regs = 0;
5517 if (reg_parm_stack_space == 0)
5518 part_size_in_regs = ((partial * UNITS_PER_WORD)
5519 / (PARM_BOUNDARY / BITS_PER_UNIT)
5520 * (PARM_BOUNDARY / BITS_PER_UNIT));
5523 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
5524 where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
5525 boundary = FUNCTION_ARG_BOUNDARY (passed_mode, type);
5526 locate->where_pad = where_pad;
5528 #ifdef ARGS_GROW_DOWNWARD
5529 locate->slot_offset.constant = -initial_offset_ptr->constant;
5530 if (initial_offset_ptr->var)
5531 locate->slot_offset.var = size_binop (MINUS_EXPR, ssize_int (0),
5532 initial_offset_ptr->var);
5536 if (where_pad != none
5537 && (!host_integerp (sizetree, 1)
5538 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
5539 s2 = round_up (s2, PARM_BOUNDARY / BITS_PER_UNIT);
5540 SUB_PARM_SIZE (locate->slot_offset, s2);
5543 locate->slot_offset.constant += part_size_in_regs;
5546 #ifdef REG_PARM_STACK_SPACE
5547 || REG_PARM_STACK_SPACE (fndecl) > 0
5550 pad_to_arg_alignment (&locate->slot_offset, boundary,
5551 &locate->alignment_pad);
5553 locate->size.constant = (-initial_offset_ptr->constant
5554 - locate->slot_offset.constant);
5555 if (initial_offset_ptr->var)
5556 locate->size.var = size_binop (MINUS_EXPR,
5557 size_binop (MINUS_EXPR,
5559 initial_offset_ptr->var),
5560 locate->slot_offset.var);
5562 /* Pad_below needs the pre-rounded size to know how much to pad
5564 locate->offset = locate->slot_offset;
5565 if (where_pad == downward)
5566 pad_below (&locate->offset, passed_mode, sizetree);
5568 #else /* !ARGS_GROW_DOWNWARD */
5570 #ifdef REG_PARM_STACK_SPACE
5571 || REG_PARM_STACK_SPACE (fndecl) > 0
5574 pad_to_arg_alignment (initial_offset_ptr, boundary,
5575 &locate->alignment_pad);
5576 locate->slot_offset = *initial_offset_ptr;
5578 #ifdef PUSH_ROUNDING
5579 if (passed_mode != BLKmode)
5580 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
5583 /* Pad_below needs the pre-rounded size to know how much to pad below
5584 so this must be done before rounding up. */
5585 locate->offset = locate->slot_offset;
5586 if (where_pad == downward)
5587 pad_below (&locate->offset, passed_mode, sizetree);
5589 if (where_pad != none
5590 && (!host_integerp (sizetree, 1)
5591 || (tree_low_cst (sizetree, 1) * BITS_PER_UNIT) % PARM_BOUNDARY))
5592 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
5594 ADD_PARM_SIZE (locate->size, sizetree);
5596 locate->size.constant -= part_size_in_regs;
5597 #endif /* ARGS_GROW_DOWNWARD */
5600 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
5601 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
5604 pad_to_arg_alignment (struct args_size *offset_ptr, int boundary,
5605 struct args_size *alignment_pad)
5607 tree save_var = NULL_TREE;
5608 HOST_WIDE_INT save_constant = 0;
5609 int boundary_in_bytes = boundary / BITS_PER_UNIT;
5610 HOST_WIDE_INT sp_offset = STACK_POINTER_OFFSET;
5612 #ifdef SPARC_STACK_BOUNDARY_HACK
5613 /* The sparc port has a bug. It sometimes claims a STACK_BOUNDARY
5614 higher than the real alignment of %sp. However, when it does this,
5615 the alignment of %sp+STACK_POINTER_OFFSET will be STACK_BOUNDARY.
5616 This is a temporary hack while the sparc port is fixed. */
5617 if (SPARC_STACK_BOUNDARY_HACK)
5621 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
5623 save_var = offset_ptr->var;
5624 save_constant = offset_ptr->constant;
5627 alignment_pad->var = NULL_TREE;
5628 alignment_pad->constant = 0;
5630 if (boundary > BITS_PER_UNIT)
5632 if (offset_ptr->var)
5634 tree sp_offset_tree = ssize_int (sp_offset);
5635 tree offset = size_binop (PLUS_EXPR,
5636 ARGS_SIZE_TREE (*offset_ptr),
5638 #ifdef ARGS_GROW_DOWNWARD
5639 tree rounded = round_down (offset, boundary / BITS_PER_UNIT);
5641 tree rounded = round_up (offset, boundary / BITS_PER_UNIT);
5644 offset_ptr->var = size_binop (MINUS_EXPR, rounded, sp_offset_tree);
5645 /* ARGS_SIZE_TREE includes constant term. */
5646 offset_ptr->constant = 0;
5647 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
5648 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
5653 offset_ptr->constant = -sp_offset +
5654 #ifdef ARGS_GROW_DOWNWARD
5655 FLOOR_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
5657 CEIL_ROUND (offset_ptr->constant + sp_offset, boundary_in_bytes);
5659 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
5660 alignment_pad->constant = offset_ptr->constant - save_constant;
5666 pad_below (struct args_size *offset_ptr, enum machine_mode passed_mode, tree sizetree)
5668 if (passed_mode != BLKmode)
5670 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
5671 offset_ptr->constant
5672 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
5673 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
5674 - GET_MODE_SIZE (passed_mode));
5678 if (TREE_CODE (sizetree) != INTEGER_CST
5679 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
5681 /* Round the size up to multiple of PARM_BOUNDARY bits. */
5682 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
5684 ADD_PARM_SIZE (*offset_ptr, s2);
5685 SUB_PARM_SIZE (*offset_ptr, sizetree);
5690 /* Walk the tree of blocks describing the binding levels within a function
5691 and warn about variables the might be killed by setjmp or vfork.
5692 This is done after calling flow_analysis and before global_alloc
5693 clobbers the pseudo-regs to hard regs. */
5696 setjmp_vars_warning (tree block)
5700 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
5702 if (TREE_CODE (decl) == VAR_DECL
5703 && DECL_RTL_SET_P (decl)
5704 && REG_P (DECL_RTL (decl))
5705 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
5706 warning ("%Jvariable '%D' might be clobbered by `longjmp' or `vfork'",
5710 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
5711 setjmp_vars_warning (sub);
5714 /* Do the appropriate part of setjmp_vars_warning
5715 but for arguments instead of local variables. */
5718 setjmp_args_warning (void)
5721 for (decl = DECL_ARGUMENTS (current_function_decl);
5722 decl; decl = TREE_CHAIN (decl))
5723 if (DECL_RTL (decl) != 0
5724 && REG_P (DECL_RTL (decl))
5725 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
5726 warning ("%Jargument '%D' might be clobbered by `longjmp' or `vfork'",
5730 /* If this function call setjmp, put all vars into the stack
5731 unless they were declared `register'. */
5734 setjmp_protect (tree block)
5737 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
5738 if ((TREE_CODE (decl) == VAR_DECL
5739 || TREE_CODE (decl) == PARM_DECL)
5740 && DECL_RTL (decl) != 0
5741 && (REG_P (DECL_RTL (decl))
5742 || (GET_CODE (DECL_RTL (decl)) == MEM
5743 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == ADDRESSOF))
5744 /* If this variable came from an inline function, it must be
5745 that its life doesn't overlap the setjmp. If there was a
5746 setjmp in the function, it would already be in memory. We
5747 must exclude such variable because their DECL_RTL might be
5748 set to strange things such as virtual_stack_vars_rtx. */
5749 && ! DECL_FROM_INLINE (decl)
5751 #ifdef NON_SAVING_SETJMP
5752 /* If longjmp doesn't restore the registers,
5753 don't put anything in them. */
5757 ! DECL_REGISTER (decl)))
5758 put_var_into_stack (decl, /*rescan=*/true);
5759 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
5760 setjmp_protect (sub);
5763 /* Like the previous function, but for args instead of local variables. */
5766 setjmp_protect_args (void)
5769 for (decl = DECL_ARGUMENTS (current_function_decl);
5770 decl; decl = TREE_CHAIN (decl))
5771 if ((TREE_CODE (decl) == VAR_DECL
5772 || TREE_CODE (decl) == PARM_DECL)
5773 && DECL_RTL (decl) != 0
5774 && (REG_P (DECL_RTL (decl))
5775 || (GET_CODE (DECL_RTL (decl)) == MEM
5776 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == ADDRESSOF))
5778 /* If longjmp doesn't restore the registers,
5779 don't put anything in them. */
5780 #ifdef NON_SAVING_SETJMP
5784 ! DECL_REGISTER (decl)))
5785 put_var_into_stack (decl, /*rescan=*/true);
5788 /* Convert a stack slot address ADDR for variable VAR
5789 (from a containing function)
5790 into an address valid in this function (using a static chain). */
5793 fix_lexical_addr (rtx addr, tree var)
5796 HOST_WIDE_INT displacement;
5797 tree context = decl_function_context (var);
5798 struct function *fp;
5801 /* If this is the present function, we need not do anything. */
5802 if (context == current_function_decl)
5805 fp = find_function_data (context);
5807 if (GET_CODE (addr) == ADDRESSOF && GET_CODE (XEXP (addr, 0)) == MEM)
5808 addr = XEXP (XEXP (addr, 0), 0);
5810 /* Decode given address as base reg plus displacement. */
5812 basereg = addr, displacement = 0;
5813 else if (GET_CODE (addr) == PLUS && GET_CODE (XEXP (addr, 1)) == CONST_INT)
5814 basereg = XEXP (addr, 0), displacement = INTVAL (XEXP (addr, 1));
5821 /* Use same offset, relative to appropriate static chain or argument
5823 return plus_constant (base, displacement);
5826 /* Put all this function's BLOCK nodes including those that are chained
5827 onto the first block into a vector, and return it.
5828 Also store in each NOTE for the beginning or end of a block
5829 the index of that block in the vector.
5830 The arguments are BLOCK, the chain of top-level blocks of the function,
5831 and INSNS, the insn chain of the function. */
5834 identify_blocks (void)
5837 tree *block_vector, *last_block_vector;
5839 tree block = DECL_INITIAL (current_function_decl);
5844 /* Fill the BLOCK_VECTOR with all of the BLOCKs in this function, in
5845 depth-first order. */
5846 block_vector = get_block_vector (block, &n_blocks);
5847 block_stack = xmalloc (n_blocks * sizeof (tree));
5849 last_block_vector = identify_blocks_1 (get_insns (),
5851 block_vector + n_blocks,
5854 /* If we didn't use all of the subblocks, we've misplaced block notes. */
5855 /* ??? This appears to happen all the time. Latent bugs elsewhere? */
5856 if (0 && last_block_vector != block_vector + n_blocks)
5859 free (block_vector);
5863 /* Subroutine of identify_blocks. Do the block substitution on the
5864 insn chain beginning with INSNS.
5866 BLOCK_STACK is pushed and popped for each BLOCK_BEGIN/BLOCK_END pair.
5867 BLOCK_VECTOR is incremented for each block seen. */
5870 identify_blocks_1 (rtx insns, tree *block_vector, tree *end_block_vector,
5871 tree *orig_block_stack)
5874 tree *block_stack = orig_block_stack;
5876 for (insn = insns; insn; insn = NEXT_INSN (insn))
5878 if (GET_CODE (insn) == NOTE)
5880 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
5884 /* If there are more block notes than BLOCKs, something
5886 if (block_vector == end_block_vector)
5889 b = *block_vector++;
5890 NOTE_BLOCK (insn) = b;
5893 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
5895 /* If there are more NOTE_INSN_BLOCK_ENDs than
5896 NOTE_INSN_BLOCK_BEGs, something is badly wrong. */
5897 if (block_stack == orig_block_stack)
5900 NOTE_BLOCK (insn) = *--block_stack;
5905 /* If there are more NOTE_INSN_BLOCK_BEGINs than NOTE_INSN_BLOCK_ENDs,
5906 something is badly wrong. */
5907 if (block_stack != orig_block_stack)
5910 return block_vector;
5913 /* Identify BLOCKs referenced by more than one NOTE_INSN_BLOCK_{BEG,END},
5914 and create duplicate blocks. */
5915 /* ??? Need an option to either create block fragments or to create
5916 abstract origin duplicates of a source block. It really depends
5917 on what optimization has been performed. */
5920 reorder_blocks (void)
5922 tree block = DECL_INITIAL (current_function_decl);
5923 varray_type block_stack;
5925 if (block == NULL_TREE)
5928 VARRAY_TREE_INIT (block_stack, 10, "block_stack");
5930 /* Reset the TREE_ASM_WRITTEN bit for all blocks. */
5931 clear_block_marks (block);
5933 /* Prune the old trees away, so that they don't get in the way. */
5934 BLOCK_SUBBLOCKS (block) = NULL_TREE;
5935 BLOCK_CHAIN (block) = NULL_TREE;
5937 /* Recreate the block tree from the note nesting. */
5938 reorder_blocks_1 (get_insns (), block, &block_stack);
5939 BLOCK_SUBBLOCKS (block) = blocks_nreverse (BLOCK_SUBBLOCKS (block));
5941 /* Remove deleted blocks from the block fragment chains. */
5942 reorder_fix_fragments (block);
5945 /* Helper function for reorder_blocks. Reset TREE_ASM_WRITTEN. */
5948 clear_block_marks (tree block)
5952 TREE_ASM_WRITTEN (block) = 0;
5953 clear_block_marks (BLOCK_SUBBLOCKS (block));
5954 block = BLOCK_CHAIN (block);
5959 reorder_blocks_1 (rtx insns, tree current_block, varray_type *p_block_stack)
5963 for (insn = insns; insn; insn = NEXT_INSN (insn))
5965 if (GET_CODE (insn) == NOTE)
5967 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
5969 tree block = NOTE_BLOCK (insn);
5971 /* If we have seen this block before, that means it now
5972 spans multiple address regions. Create a new fragment. */
5973 if (TREE_ASM_WRITTEN (block))
5975 tree new_block = copy_node (block);
5978 origin = (BLOCK_FRAGMENT_ORIGIN (block)
5979 ? BLOCK_FRAGMENT_ORIGIN (block)
5981 BLOCK_FRAGMENT_ORIGIN (new_block) = origin;
5982 BLOCK_FRAGMENT_CHAIN (new_block)
5983 = BLOCK_FRAGMENT_CHAIN (origin);
5984 BLOCK_FRAGMENT_CHAIN (origin) = new_block;
5986 NOTE_BLOCK (insn) = new_block;
5990 BLOCK_SUBBLOCKS (block) = 0;
5991 TREE_ASM_WRITTEN (block) = 1;
5992 /* When there's only one block for the entire function,
5993 current_block == block and we mustn't do this, it
5994 will cause infinite recursion. */
5995 if (block != current_block)
5997 BLOCK_SUPERCONTEXT (block) = current_block;
5998 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
5999 BLOCK_SUBBLOCKS (current_block) = block;
6000 current_block = block;
6002 VARRAY_PUSH_TREE (*p_block_stack, block);
6004 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
6006 NOTE_BLOCK (insn) = VARRAY_TOP_TREE (*p_block_stack);
6007 VARRAY_POP (*p_block_stack);
6008 BLOCK_SUBBLOCKS (current_block)
6009 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block));
6010 current_block = BLOCK_SUPERCONTEXT (current_block);
6016 /* Rationalize BLOCK_FRAGMENT_ORIGIN. If an origin block no longer
6017 appears in the block tree, select one of the fragments to become
6018 the new origin block. */
6021 reorder_fix_fragments (tree block)
6025 tree dup_origin = BLOCK_FRAGMENT_ORIGIN (block);
6026 tree new_origin = NULL_TREE;
6030 if (! TREE_ASM_WRITTEN (dup_origin))
6032 new_origin = BLOCK_FRAGMENT_CHAIN (dup_origin);
6034 /* Find the first of the remaining fragments. There must
6035 be at least one -- the current block. */
6036 while (! TREE_ASM_WRITTEN (new_origin))
6037 new_origin = BLOCK_FRAGMENT_CHAIN (new_origin);
6038 BLOCK_FRAGMENT_ORIGIN (new_origin) = NULL_TREE;
6041 else if (! dup_origin)
6044 /* Re-root the rest of the fragments to the new origin. In the
6045 case that DUP_ORIGIN was null, that means BLOCK was the origin
6046 of a chain of fragments and we want to remove those fragments
6047 that didn't make it to the output. */
6050 tree *pp = &BLOCK_FRAGMENT_CHAIN (new_origin);
6055 if (TREE_ASM_WRITTEN (chain))
6057 BLOCK_FRAGMENT_ORIGIN (chain) = new_origin;
6059 pp = &BLOCK_FRAGMENT_CHAIN (chain);
6061 chain = BLOCK_FRAGMENT_CHAIN (chain);
6066 reorder_fix_fragments (BLOCK_SUBBLOCKS (block));
6067 block = BLOCK_CHAIN (block);
6071 /* Reverse the order of elements in the chain T of blocks,
6072 and return the new head of the chain (old last element). */
6075 blocks_nreverse (tree t)
6077 tree prev = 0, decl, next;
6078 for (decl = t; decl; decl = next)
6080 next = BLOCK_CHAIN (decl);
6081 BLOCK_CHAIN (decl) = prev;
6087 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
6088 non-NULL, list them all into VECTOR, in a depth-first preorder
6089 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
6093 all_blocks (tree block, tree *vector)
6099 TREE_ASM_WRITTEN (block) = 0;
6101 /* Record this block. */
6103 vector[n_blocks] = block;
6107 /* Record the subblocks, and their subblocks... */
6108 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
6109 vector ? vector + n_blocks : 0);
6110 block = BLOCK_CHAIN (block);
6116 /* Return a vector containing all the blocks rooted at BLOCK. The
6117 number of elements in the vector is stored in N_BLOCKS_P. The
6118 vector is dynamically allocated; it is the caller's responsibility
6119 to call `free' on the pointer returned. */
6122 get_block_vector (tree block, int *n_blocks_p)
6126 *n_blocks_p = all_blocks (block, NULL);
6127 block_vector = xmalloc (*n_blocks_p * sizeof (tree));
6128 all_blocks (block, block_vector);
6130 return block_vector;
6133 static GTY(()) int next_block_index = 2;
6135 /* Set BLOCK_NUMBER for all the blocks in FN. */
6138 number_blocks (tree fn)
6144 /* For SDB and XCOFF debugging output, we start numbering the blocks
6145 from 1 within each function, rather than keeping a running
6147 #if defined (SDB_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
6148 if (write_symbols == SDB_DEBUG || write_symbols == XCOFF_DEBUG)
6149 next_block_index = 1;
6152 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
6154 /* The top-level BLOCK isn't numbered at all. */
6155 for (i = 1; i < n_blocks; ++i)
6156 /* We number the blocks from two. */
6157 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
6159 free (block_vector);
6164 /* If VAR is present in a subblock of BLOCK, return the subblock. */
6167 debug_find_var_in_block_tree (tree var, tree block)
6171 for (t = BLOCK_VARS (block); t; t = TREE_CHAIN (t))
6175 for (t = BLOCK_SUBBLOCKS (block); t; t = TREE_CHAIN (t))
6177 tree ret = debug_find_var_in_block_tree (var, t);
6185 /* Allocate a function structure for FNDECL and set its contents
6189 allocate_struct_function (tree fndecl)
6192 tree fntype = fndecl ? TREE_TYPE (fndecl) : NULL_TREE;
6194 cfun = ggc_alloc_cleared (sizeof (struct function));
6196 max_parm_reg = LAST_VIRTUAL_REGISTER + 1;
6198 cfun->stack_alignment_needed = STACK_BOUNDARY;
6199 cfun->preferred_stack_boundary = STACK_BOUNDARY;
6201 current_function_funcdef_no = funcdef_no++;
6203 cfun->function_frequency = FUNCTION_FREQUENCY_NORMAL;
6205 init_stmt_for_function ();
6206 init_eh_for_function ();
6208 lang_hooks.function.init (cfun);
6209 if (init_machine_status)
6210 cfun->machine = (*init_machine_status) ();
6215 DECL_STRUCT_FUNCTION (fndecl) = cfun;
6216 cfun->decl = fndecl;
6218 result = DECL_RESULT (fndecl);
6219 if (aggregate_value_p (result, fndecl))
6221 #ifdef PCC_STATIC_STRUCT_RETURN
6222 current_function_returns_pcc_struct = 1;
6224 current_function_returns_struct = 1;
6227 current_function_returns_pointer = POINTER_TYPE_P (TREE_TYPE (result));
6229 current_function_stdarg
6231 && TYPE_ARG_TYPES (fntype) != 0
6232 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
6233 != void_type_node));
6236 /* Reset cfun, and other non-struct-function variables to defaults as
6237 appropriate for emitting rtl at the start of a function. */
6240 prepare_function_start (tree fndecl)
6242 if (fndecl && DECL_STRUCT_FUNCTION (fndecl))
6243 cfun = DECL_STRUCT_FUNCTION (fndecl);
6245 allocate_struct_function (fndecl);
6247 init_varasm_status (cfun);
6250 cse_not_expected = ! optimize;
6252 /* Caller save not needed yet. */
6253 caller_save_needed = 0;
6255 /* We haven't done register allocation yet. */
6258 /* Indicate that we need to distinguish between the return value of the
6259 present function and the return value of a function being called. */
6260 rtx_equal_function_value_matters = 1;
6262 /* Indicate that we have not instantiated virtual registers yet. */
6263 virtuals_instantiated = 0;
6265 /* Indicate that we want CONCATs now. */
6266 generating_concat_p = 1;
6268 /* Indicate we have no need of a frame pointer yet. */
6269 frame_pointer_needed = 0;
6272 /* Initialize the rtl expansion mechanism so that we can do simple things
6273 like generate sequences. This is used to provide a context during global
6274 initialization of some passes. */
6276 init_dummy_function_start (void)
6278 prepare_function_start (NULL);
6281 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
6282 and initialize static variables for generating RTL for the statements
6286 init_function_start (tree subr)
6288 prepare_function_start (subr);
6290 /* Prevent ever trying to delete the first instruction of a
6291 function. Also tell final how to output a linenum before the
6292 function prologue. Note linenums could be missing, e.g. when
6293 compiling a Java .class file. */
6294 if (! DECL_IS_BUILTIN (subr))
6295 emit_line_note (DECL_SOURCE_LOCATION (subr));
6297 /* Make sure first insn is a note even if we don't want linenums.
6298 This makes sure the first insn will never be deleted.
6299 Also, final expects a note to appear there. */
6300 emit_note (NOTE_INSN_DELETED);
6302 /* Warn if this value is an aggregate type,
6303 regardless of which calling convention we are using for it. */
6304 if (warn_aggregate_return
6305 && AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
6306 warning ("function returns an aggregate");
6309 /* Make sure all values used by the optimization passes have sane
6312 init_function_for_compilation (void)
6316 /* No prologue/epilogue insns yet. */
6317 VARRAY_GROW (prologue, 0);
6318 VARRAY_GROW (epilogue, 0);
6319 VARRAY_GROW (sibcall_epilogue, 0);
6322 /* Expand a call to __main at the beginning of a possible main function. */
6324 #if defined(INIT_SECTION_ASM_OP) && !defined(INVOKE__main)
6325 #undef HAS_INIT_SECTION
6326 #define HAS_INIT_SECTION
6330 expand_main_function (void)
6332 #ifdef FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN
6333 if (FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN)
6335 int align = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
6339 /* Forcibly align the stack. */
6340 #ifdef STACK_GROWS_DOWNWARD
6341 tmp = expand_simple_binop (Pmode, AND, stack_pointer_rtx, GEN_INT(-align),
6342 stack_pointer_rtx, 1, OPTAB_WIDEN);
6344 tmp = expand_simple_binop (Pmode, PLUS, stack_pointer_rtx,
6345 GEN_INT (align - 1), NULL_RTX, 1, OPTAB_WIDEN);
6346 tmp = expand_simple_binop (Pmode, AND, tmp, GEN_INT (-align),
6347 stack_pointer_rtx, 1, OPTAB_WIDEN);
6349 if (tmp != stack_pointer_rtx)
6350 emit_move_insn (stack_pointer_rtx, tmp);
6352 /* Enlist allocate_dynamic_stack_space to pick up the pieces. */
6353 tmp = force_reg (Pmode, const0_rtx);
6354 allocate_dynamic_stack_space (tmp, NULL_RTX, BIGGEST_ALIGNMENT);
6358 for (tmp = get_last_insn (); tmp; tmp = PREV_INSN (tmp))
6359 if (NOTE_P (tmp) && NOTE_LINE_NUMBER (tmp) == NOTE_INSN_FUNCTION_BEG)
6362 emit_insn_before (seq, tmp);
6368 #ifndef HAS_INIT_SECTION
6369 emit_library_call (init_one_libfunc (NAME__MAIN), LCT_NORMAL, VOIDmode, 0);
6373 /* The PENDING_SIZES represent the sizes of variable-sized types.
6374 Create RTL for the various sizes now (using temporary variables),
6375 so that we can refer to the sizes from the RTL we are generating
6376 for the current function. The PENDING_SIZES are a TREE_LIST. The
6377 TREE_VALUE of each node is a SAVE_EXPR. */
6380 expand_pending_sizes (tree pending_sizes)
6384 /* Evaluate now the sizes of any types declared among the arguments. */
6385 for (tem = pending_sizes; tem; tem = TREE_CHAIN (tem))
6387 expand_expr (TREE_VALUE (tem), const0_rtx, VOIDmode, 0);
6388 /* Flush the queue in case this parameter declaration has
6394 /* Start the RTL for a new function, and set variables used for
6396 SUBR is the FUNCTION_DECL node.
6397 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
6398 the function's parameters, which must be run at any return statement. */
6401 expand_function_start (tree subr, int parms_have_cleanups)
6403 /* Make sure volatile mem refs aren't considered
6404 valid operands of arithmetic insns. */
6405 init_recog_no_volatile ();
6407 current_function_profile
6409 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
6411 current_function_limit_stack
6412 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
6414 /* If the parameters of this function need cleaning up, get a label
6415 for the beginning of the code which executes those cleanups. This must
6416 be done before doing anything with return_label. */
6417 if (parms_have_cleanups)
6418 cleanup_label = gen_label_rtx ();
6422 /* Make the label for return statements to jump to. Do not special
6423 case machines with special return instructions -- they will be
6424 handled later during jump, ifcvt, or epilogue creation. */
6425 return_label = gen_label_rtx ();
6427 /* Initialize rtx used to return the value. */
6428 /* Do this before assign_parms so that we copy the struct value address
6429 before any library calls that assign parms might generate. */
6431 /* Decide whether to return the value in memory or in a register. */
6432 if (aggregate_value_p (DECL_RESULT (subr), subr))
6434 /* Returning something that won't go in a register. */
6435 rtx value_address = 0;
6437 #ifdef PCC_STATIC_STRUCT_RETURN
6438 if (current_function_returns_pcc_struct)
6440 int size = int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr)));
6441 value_address = assemble_static_space (size);
6446 rtx sv = targetm.calls.struct_value_rtx (TREE_TYPE (subr), 1);
6447 /* Expect to be passed the address of a place to store the value.
6448 If it is passed as an argument, assign_parms will take care of
6452 value_address = gen_reg_rtx (Pmode);
6453 emit_move_insn (value_address, sv);
6458 rtx x = gen_rtx_MEM (DECL_MODE (DECL_RESULT (subr)), value_address);
6459 set_mem_attributes (x, DECL_RESULT (subr), 1);
6460 SET_DECL_RTL (DECL_RESULT (subr), x);
6463 else if (DECL_MODE (DECL_RESULT (subr)) == VOIDmode)
6464 /* If return mode is void, this decl rtl should not be used. */
6465 SET_DECL_RTL (DECL_RESULT (subr), NULL_RTX);
6468 /* Compute the return values into a pseudo reg, which we will copy
6469 into the true return register after the cleanups are done. */
6471 /* In order to figure out what mode to use for the pseudo, we
6472 figure out what the mode of the eventual return register will
6473 actually be, and use that. */
6475 = hard_function_value (TREE_TYPE (DECL_RESULT (subr)),
6478 /* Structures that are returned in registers are not aggregate_value_p,
6479 so we may see a PARALLEL or a REG. */
6480 if (REG_P (hard_reg))
6481 SET_DECL_RTL (DECL_RESULT (subr), gen_reg_rtx (GET_MODE (hard_reg)));
6482 else if (GET_CODE (hard_reg) == PARALLEL)
6483 SET_DECL_RTL (DECL_RESULT (subr), gen_group_rtx (hard_reg));
6487 /* Set DECL_REGISTER flag so that expand_function_end will copy the
6488 result to the real return register(s). */
6489 DECL_REGISTER (DECL_RESULT (subr)) = 1;
6492 /* Initialize rtx for parameters and local variables.
6493 In some cases this requires emitting insns. */
6494 assign_parms (subr);
6496 /* If function gets a static chain arg, store it. */
6497 if (cfun->static_chain_decl)
6499 tree parm = cfun->static_chain_decl;
6500 rtx local = gen_reg_rtx (Pmode);
6502 set_decl_incoming_rtl (parm, static_chain_incoming_rtx);
6503 SET_DECL_RTL (parm, local);
6504 maybe_set_unchanging (local, parm);
6505 mark_reg_pointer (local, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
6507 emit_move_insn (local, static_chain_incoming_rtx);
6510 /* If the function receives a non-local goto, then store the
6511 bits we need to restore the frame pointer. */
6512 if (cfun->nonlocal_goto_save_area)
6517 /* ??? We need to do this save early. Unfortunately here is
6518 before the frame variable gets declared. Help out... */
6519 expand_var (TREE_OPERAND (cfun->nonlocal_goto_save_area, 0));
6521 t_save = build (ARRAY_REF, ptr_type_node, cfun->nonlocal_goto_save_area,
6522 integer_zero_node, NULL_TREE, NULL_TREE);
6523 r_save = expand_expr (t_save, NULL_RTX, VOIDmode, EXPAND_WRITE);
6525 emit_move_insn (r_save, virtual_stack_vars_rtx);
6526 update_nonlocal_goto_save_area ();
6529 /* The following was moved from init_function_start.
6530 The move is supposed to make sdb output more accurate. */
6531 /* Indicate the beginning of the function body,
6532 as opposed to parm setup. */
6533 emit_note (NOTE_INSN_FUNCTION_BEG);
6535 if (GET_CODE (get_last_insn ()) != NOTE)
6536 emit_note (NOTE_INSN_DELETED);
6537 parm_birth_insn = get_last_insn ();
6539 if (current_function_profile)
6542 PROFILE_HOOK (current_function_funcdef_no);
6546 /* After the display initializations is where the tail-recursion label
6547 should go, if we end up needing one. Ensure we have a NOTE here
6548 since some things (like trampolines) get placed before this. */
6549 tail_recursion_reentry = emit_note (NOTE_INSN_DELETED);
6551 /* Evaluate now the sizes of any types declared among the arguments. */
6552 expand_pending_sizes (nreverse (get_pending_sizes ()));
6554 /* Make sure there is a line number after the function entry setup code. */
6555 force_next_line_note ();
6558 /* Undo the effects of init_dummy_function_start. */
6560 expand_dummy_function_end (void)
6562 /* End any sequences that failed to be closed due to syntax errors. */
6563 while (in_sequence_p ())
6566 /* Outside function body, can't compute type's actual size
6567 until next function's body starts. */
6569 free_after_parsing (cfun);
6570 free_after_compilation (cfun);
6574 /* Call DOIT for each hard register used as a return value from
6575 the current function. */
6578 diddle_return_value (void (*doit) (rtx, void *), void *arg)
6580 rtx outgoing = current_function_return_rtx;
6585 if (REG_P (outgoing))
6586 (*doit) (outgoing, arg);
6587 else if (GET_CODE (outgoing) == PARALLEL)
6591 for (i = 0; i < XVECLEN (outgoing, 0); i++)
6593 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
6595 if (REG_P (x) && REGNO (x) < FIRST_PSEUDO_REGISTER)
6602 do_clobber_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
6604 emit_insn (gen_rtx_CLOBBER (VOIDmode, reg));
6608 clobber_return_register (void)
6610 diddle_return_value (do_clobber_return_reg, NULL);
6612 /* In case we do use pseudo to return value, clobber it too. */
6613 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
6615 tree decl_result = DECL_RESULT (current_function_decl);
6616 rtx decl_rtl = DECL_RTL (decl_result);
6617 if (REG_P (decl_rtl) && REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER)
6619 do_clobber_return_reg (decl_rtl, NULL);
6625 do_use_return_reg (rtx reg, void *arg ATTRIBUTE_UNUSED)
6627 emit_insn (gen_rtx_USE (VOIDmode, reg));
6631 use_return_register (void)
6633 diddle_return_value (do_use_return_reg, NULL);
6636 /* Possibly warn about unused parameters. */
6638 do_warn_unused_parameter (tree fn)
6642 for (decl = DECL_ARGUMENTS (fn);
6643 decl; decl = TREE_CHAIN (decl))
6644 if (!TREE_USED (decl) && TREE_CODE (decl) == PARM_DECL
6645 && DECL_NAME (decl) && !DECL_ARTIFICIAL (decl))
6646 warning ("%Junused parameter '%D'", decl, decl);
6649 static GTY(()) rtx initial_trampoline;
6651 /* Generate RTL for the end of the current function. */
6654 expand_function_end (void)
6658 finish_expr_for_function ();
6660 /* If arg_pointer_save_area was referenced only from a nested
6661 function, we will not have initialized it yet. Do that now. */
6662 if (arg_pointer_save_area && ! cfun->arg_pointer_save_area_init)
6663 get_arg_pointer_save_area (cfun);
6665 #ifdef NON_SAVING_SETJMP
6666 /* Don't put any variables in registers if we call setjmp
6667 on a machine that fails to restore the registers. */
6668 if (NON_SAVING_SETJMP && current_function_calls_setjmp)
6670 if (DECL_INITIAL (current_function_decl) != error_mark_node)
6671 setjmp_protect (DECL_INITIAL (current_function_decl));
6673 setjmp_protect_args ();
6677 /* If we are doing stack checking and this function makes calls,
6678 do a stack probe at the start of the function to ensure we have enough
6679 space for another stack frame. */
6680 if (flag_stack_check && ! STACK_CHECK_BUILTIN)
6684 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
6685 if (GET_CODE (insn) == CALL_INSN)
6688 probe_stack_range (STACK_CHECK_PROTECT,
6689 GEN_INT (STACK_CHECK_MAX_FRAME_SIZE));
6692 emit_insn_before (seq, tail_recursion_reentry);
6697 /* Possibly warn about unused parameters.
6698 When frontend does unit-at-a-time, the warning is already
6699 issued at finalization time. */
6700 if (warn_unused_parameter
6701 && !lang_hooks.callgraph.expand_function)
6702 do_warn_unused_parameter (current_function_decl);
6704 /* End any sequences that failed to be closed due to syntax errors. */
6705 while (in_sequence_p ())
6708 clear_pending_stack_adjust ();
6709 do_pending_stack_adjust ();
6711 /* @@@ This is a kludge. We want to ensure that instructions that
6712 may trap are not moved into the epilogue by scheduling, because
6713 we don't always emit unwind information for the epilogue.
6714 However, not all machine descriptions define a blockage insn, so
6715 emit an ASM_INPUT to act as one. */
6716 if (flag_non_call_exceptions)
6717 emit_insn (gen_rtx_ASM_INPUT (VOIDmode, ""));
6719 /* Mark the end of the function body.
6720 If control reaches this insn, the function can drop through
6721 without returning a value. */
6722 emit_note (NOTE_INSN_FUNCTION_END);
6724 /* Must mark the last line number note in the function, so that the test
6725 coverage code can avoid counting the last line twice. This just tells
6726 the code to ignore the immediately following line note, since there
6727 already exists a copy of this note somewhere above. This line number
6728 note is still needed for debugging though, so we can't delete it. */
6729 if (flag_test_coverage)
6730 emit_note (NOTE_INSN_REPEATED_LINE_NUMBER);
6732 /* Output a linenumber for the end of the function.
6733 SDB depends on this. */
6734 force_next_line_note ();
6735 emit_line_note (input_location);
6737 /* Before the return label (if any), clobber the return
6738 registers so that they are not propagated live to the rest of
6739 the function. This can only happen with functions that drop
6740 through; if there had been a return statement, there would
6741 have either been a return rtx, or a jump to the return label.
6743 We delay actual code generation after the current_function_value_rtx
6745 clobber_after = get_last_insn ();
6747 /* Output the label for the actual return from the function,
6748 if one is expected. This happens either because a function epilogue
6749 is used instead of a return instruction, or because a return was done
6750 with a goto in order to run local cleanups, or because of pcc-style
6751 structure returning. */
6753 emit_label (return_label);
6755 /* Let except.c know where it should emit the call to unregister
6756 the function context for sjlj exceptions. */
6757 if (flag_exceptions && USING_SJLJ_EXCEPTIONS)
6758 sjlj_emit_function_exit_after (get_last_insn ());
6760 /* If we had calls to alloca, and this machine needs
6761 an accurate stack pointer to exit the function,
6762 insert some code to save and restore the stack pointer. */
6763 if (! EXIT_IGNORE_STACK
6764 && current_function_calls_alloca)
6768 emit_stack_save (SAVE_FUNCTION, &tem, parm_birth_insn);
6769 emit_stack_restore (SAVE_FUNCTION, tem, NULL_RTX);
6772 /* If scalar return value was computed in a pseudo-reg, or was a named
6773 return value that got dumped to the stack, copy that to the hard
6775 if (DECL_RTL_SET_P (DECL_RESULT (current_function_decl)))
6777 tree decl_result = DECL_RESULT (current_function_decl);
6778 rtx decl_rtl = DECL_RTL (decl_result);
6780 if (REG_P (decl_rtl)
6781 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
6782 : DECL_REGISTER (decl_result))
6784 rtx real_decl_rtl = current_function_return_rtx;
6786 /* This should be set in assign_parms. */
6787 if (! REG_FUNCTION_VALUE_P (real_decl_rtl))
6790 /* If this is a BLKmode structure being returned in registers,
6791 then use the mode computed in expand_return. Note that if
6792 decl_rtl is memory, then its mode may have been changed,
6793 but that current_function_return_rtx has not. */
6794 if (GET_MODE (real_decl_rtl) == BLKmode)
6795 PUT_MODE (real_decl_rtl, GET_MODE (decl_rtl));
6797 /* If a named return value dumped decl_return to memory, then
6798 we may need to re-do the PROMOTE_MODE signed/unsigned
6800 if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
6802 int unsignedp = TYPE_UNSIGNED (TREE_TYPE (decl_result));
6804 if (targetm.calls.promote_function_return (TREE_TYPE (current_function_decl)))
6805 promote_mode (TREE_TYPE (decl_result), GET_MODE (decl_rtl),
6808 convert_move (real_decl_rtl, decl_rtl, unsignedp);
6810 else if (GET_CODE (real_decl_rtl) == PARALLEL)
6812 /* If expand_function_start has created a PARALLEL for decl_rtl,
6813 move the result to the real return registers. Otherwise, do
6814 a group load from decl_rtl for a named return. */
6815 if (GET_CODE (decl_rtl) == PARALLEL)
6816 emit_group_move (real_decl_rtl, decl_rtl);
6818 emit_group_load (real_decl_rtl, decl_rtl,
6819 TREE_TYPE (decl_result),
6820 int_size_in_bytes (TREE_TYPE (decl_result)));
6823 emit_move_insn (real_decl_rtl, decl_rtl);
6827 /* If returning a structure, arrange to return the address of the value
6828 in a place where debuggers expect to find it.
6830 If returning a structure PCC style,
6831 the caller also depends on this value.
6832 And current_function_returns_pcc_struct is not necessarily set. */
6833 if (current_function_returns_struct
6834 || current_function_returns_pcc_struct)
6837 = XEXP (DECL_RTL (DECL_RESULT (current_function_decl)), 0);
6838 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
6839 #ifdef FUNCTION_OUTGOING_VALUE
6841 = FUNCTION_OUTGOING_VALUE (build_pointer_type (type),
6842 current_function_decl);
6845 = FUNCTION_VALUE (build_pointer_type (type), current_function_decl);
6848 /* Mark this as a function return value so integrate will delete the
6849 assignment and USE below when inlining this function. */
6850 REG_FUNCTION_VALUE_P (outgoing) = 1;
6852 /* The address may be ptr_mode and OUTGOING may be Pmode. */
6853 value_address = convert_memory_address (GET_MODE (outgoing),
6856 emit_move_insn (outgoing, value_address);
6858 /* Show return register used to hold result (in this case the address
6860 current_function_return_rtx = outgoing;
6863 /* If this is an implementation of throw, do what's necessary to
6864 communicate between __builtin_eh_return and the epilogue. */
6865 expand_eh_return ();
6867 /* Emit the actual code to clobber return register. */
6872 clobber_return_register ();
6876 after = emit_insn_after (seq, clobber_after);
6879 /* Output the label for the naked return from the function, if one is
6880 expected. This is currently used only by __builtin_return. */
6881 if (naked_return_label)
6882 emit_label (naked_return_label);
6884 /* ??? This should no longer be necessary since stupid is no longer with
6885 us, but there are some parts of the compiler (eg reload_combine, and
6886 sh mach_dep_reorg) that still try and compute their own lifetime info
6887 instead of using the general framework. */
6888 use_return_register ();
6890 /* Fix up any gotos that jumped out to the outermost
6891 binding level of the function.
6892 Must follow emitting RETURN_LABEL. */
6894 /* If you have any cleanups to do at this point,
6895 and they need to create temporary variables,
6896 then you will lose. */
6897 expand_fixups (get_insns ());
6901 get_arg_pointer_save_area (struct function *f)
6903 rtx ret = f->x_arg_pointer_save_area;
6907 ret = assign_stack_local_1 (Pmode, GET_MODE_SIZE (Pmode), 0, f);
6908 f->x_arg_pointer_save_area = ret;
6911 if (f == cfun && ! f->arg_pointer_save_area_init)
6915 /* Save the arg pointer at the beginning of the function. The
6916 generated stack slot may not be a valid memory address, so we
6917 have to check it and fix it if necessary. */
6919 emit_move_insn (validize_mem (ret), virtual_incoming_args_rtx);
6923 push_topmost_sequence ();
6924 emit_insn_after (seq, get_insns ());
6925 pop_topmost_sequence ();
6931 /* Extend a vector that records the INSN_UIDs of INSNS
6932 (a list of one or more insns). */
6935 record_insns (rtx insns, varray_type *vecp)
6942 while (tmp != NULL_RTX)
6945 tmp = NEXT_INSN (tmp);
6948 i = VARRAY_SIZE (*vecp);
6949 VARRAY_GROW (*vecp, i + len);
6951 while (tmp != NULL_RTX)
6953 VARRAY_INT (*vecp, i) = INSN_UID (tmp);
6955 tmp = NEXT_INSN (tmp);
6959 /* Set the locator of the insn chain starting at INSN to LOC. */
6961 set_insn_locators (rtx insn, int loc)
6963 while (insn != NULL_RTX)
6966 INSN_LOCATOR (insn) = loc;
6967 insn = NEXT_INSN (insn);
6971 /* Determine how many INSN_UIDs in VEC are part of INSN. Because we can
6972 be running after reorg, SEQUENCE rtl is possible. */
6975 contains (rtx insn, varray_type vec)
6979 if (GET_CODE (insn) == INSN
6980 && GET_CODE (PATTERN (insn)) == SEQUENCE)
6983 for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
6984 for (j = VARRAY_SIZE (vec) - 1; j >= 0; --j)
6985 if (INSN_UID (XVECEXP (PATTERN (insn), 0, i)) == VARRAY_INT (vec, j))
6991 for (j = VARRAY_SIZE (vec) - 1; j >= 0; --j)
6992 if (INSN_UID (insn) == VARRAY_INT (vec, j))
6999 prologue_epilogue_contains (rtx insn)
7001 if (contains (insn, prologue))
7003 if (contains (insn, epilogue))
7009 sibcall_epilogue_contains (rtx insn)
7011 if (sibcall_epilogue)
7012 return contains (insn, sibcall_epilogue);
7017 /* Insert gen_return at the end of block BB. This also means updating
7018 block_for_insn appropriately. */
7021 emit_return_into_block (basic_block bb, rtx line_note)
7023 emit_jump_insn_after (gen_return (), BB_END (bb));
7025 emit_note_copy_after (line_note, PREV_INSN (BB_END (bb)));
7027 #endif /* HAVE_return */
7029 #if defined(HAVE_epilogue) && defined(INCOMING_RETURN_ADDR_RTX)
7031 /* These functions convert the epilogue into a variant that does not modify the
7032 stack pointer. This is used in cases where a function returns an object
7033 whose size is not known until it is computed. The called function leaves the
7034 object on the stack, leaves the stack depressed, and returns a pointer to
7037 What we need to do is track all modifications and references to the stack
7038 pointer, deleting the modifications and changing the references to point to
7039 the location the stack pointer would have pointed to had the modifications
7042 These functions need to be portable so we need to make as few assumptions
7043 about the epilogue as we can. However, the epilogue basically contains
7044 three things: instructions to reset the stack pointer, instructions to
7045 reload registers, possibly including the frame pointer, and an
7046 instruction to return to the caller.
7048 If we can't be sure of what a relevant epilogue insn is doing, we abort.
7049 We also make no attempt to validate the insns we make since if they are
7050 invalid, we probably can't do anything valid. The intent is that these
7051 routines get "smarter" as more and more machines start to use them and
7052 they try operating on different epilogues.
7054 We use the following structure to track what the part of the epilogue that
7055 we've already processed has done. We keep two copies of the SP equivalence,
7056 one for use during the insn we are processing and one for use in the next
7057 insn. The difference is because one part of a PARALLEL may adjust SP
7058 and the other may use it. */
7062 rtx sp_equiv_reg; /* REG that SP is set from, perhaps SP. */
7063 HOST_WIDE_INT sp_offset; /* Offset from SP_EQUIV_REG of present SP. */
7064 rtx new_sp_equiv_reg; /* REG to be used at end of insn. */
7065 HOST_WIDE_INT new_sp_offset; /* Offset to be used at end of insn. */
7066 rtx equiv_reg_src; /* If nonzero, the value that SP_EQUIV_REG
7067 should be set to once we no longer need
7069 rtx const_equiv[FIRST_PSEUDO_REGISTER]; /* Any known constant equivalences
7073 static void handle_epilogue_set (rtx, struct epi_info *);
7074 static void update_epilogue_consts (rtx, rtx, void *);
7075 static void emit_equiv_load (struct epi_info *);
7077 /* Modify INSN, a list of one or more insns that is part of the epilogue, to
7078 no modifications to the stack pointer. Return the new list of insns. */
7081 keep_stack_depressed (rtx insns)
7084 struct epi_info info;
7087 /* If the epilogue is just a single instruction, it must be OK as is. */
7088 if (NEXT_INSN (insns) == NULL_RTX)
7091 /* Otherwise, start a sequence, initialize the information we have, and
7092 process all the insns we were given. */
7095 info.sp_equiv_reg = stack_pointer_rtx;
7097 info.equiv_reg_src = 0;
7099 for (j = 0; j < FIRST_PSEUDO_REGISTER; j++)
7100 info.const_equiv[j] = 0;
7104 while (insn != NULL_RTX)
7106 next = NEXT_INSN (insn);
7115 /* If this insn references the register that SP is equivalent to and
7116 we have a pending load to that register, we must force out the load
7117 first and then indicate we no longer know what SP's equivalent is. */
7118 if (info.equiv_reg_src != 0
7119 && reg_referenced_p (info.sp_equiv_reg, PATTERN (insn)))
7121 emit_equiv_load (&info);
7122 info.sp_equiv_reg = 0;
7125 info.new_sp_equiv_reg = info.sp_equiv_reg;
7126 info.new_sp_offset = info.sp_offset;
7128 /* If this is a (RETURN) and the return address is on the stack,
7129 update the address and change to an indirect jump. */
7130 if (GET_CODE (PATTERN (insn)) == RETURN
7131 || (GET_CODE (PATTERN (insn)) == PARALLEL
7132 && GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == RETURN))
7134 rtx retaddr = INCOMING_RETURN_ADDR_RTX;
7136 HOST_WIDE_INT offset = 0;
7137 rtx jump_insn, jump_set;
7139 /* If the return address is in a register, we can emit the insn
7140 unchanged. Otherwise, it must be a MEM and we see what the
7141 base register and offset are. In any case, we have to emit any
7142 pending load to the equivalent reg of SP, if any. */
7143 if (REG_P (retaddr))
7145 emit_equiv_load (&info);
7150 else if (GET_CODE (retaddr) == MEM
7151 && REG_P (XEXP (retaddr, 0)))
7152 base = gen_rtx_REG (Pmode, REGNO (XEXP (retaddr, 0))), offset = 0;
7153 else if (GET_CODE (retaddr) == MEM
7154 && GET_CODE (XEXP (retaddr, 0)) == PLUS
7155 && REG_P (XEXP (XEXP (retaddr, 0), 0))
7156 && GET_CODE (XEXP (XEXP (retaddr, 0), 1)) == CONST_INT)
7158 base = gen_rtx_REG (Pmode, REGNO (XEXP (XEXP (retaddr, 0), 0)));
7159 offset = INTVAL (XEXP (XEXP (retaddr, 0), 1));
7164 /* If the base of the location containing the return pointer
7165 is SP, we must update it with the replacement address. Otherwise,
7166 just build the necessary MEM. */
7167 retaddr = plus_constant (base, offset);
7168 if (base == stack_pointer_rtx)
7169 retaddr = simplify_replace_rtx (retaddr, stack_pointer_rtx,
7170 plus_constant (info.sp_equiv_reg,
7173 retaddr = gen_rtx_MEM (Pmode, retaddr);
7175 /* If there is a pending load to the equivalent register for SP
7176 and we reference that register, we must load our address into
7177 a scratch register and then do that load. */
7178 if (info.equiv_reg_src
7179 && reg_overlap_mentioned_p (info.equiv_reg_src, retaddr))
7184 for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
7185 if (HARD_REGNO_MODE_OK (regno, Pmode)
7186 && !fixed_regs[regno]
7187 && TEST_HARD_REG_BIT (regs_invalidated_by_call, regno)
7188 && !REGNO_REG_SET_P (EXIT_BLOCK_PTR->global_live_at_start,
7190 && !refers_to_regno_p (regno,
7191 regno + hard_regno_nregs[regno]
7193 info.equiv_reg_src, NULL)
7194 && info.const_equiv[regno] == 0)
7197 if (regno == FIRST_PSEUDO_REGISTER)
7200 reg = gen_rtx_REG (Pmode, regno);
7201 emit_move_insn (reg, retaddr);
7205 emit_equiv_load (&info);
7206 jump_insn = emit_jump_insn (gen_indirect_jump (retaddr));
7208 /* Show the SET in the above insn is a RETURN. */
7209 jump_set = single_set (jump_insn);
7213 SET_IS_RETURN_P (jump_set) = 1;
7216 /* If SP is not mentioned in the pattern and its equivalent register, if
7217 any, is not modified, just emit it. Otherwise, if neither is set,
7218 replace the reference to SP and emit the insn. If none of those are
7219 true, handle each SET individually. */
7220 else if (!reg_mentioned_p (stack_pointer_rtx, PATTERN (insn))
7221 && (info.sp_equiv_reg == stack_pointer_rtx
7222 || !reg_set_p (info.sp_equiv_reg, insn)))
7224 else if (! reg_set_p (stack_pointer_rtx, insn)
7225 && (info.sp_equiv_reg == stack_pointer_rtx
7226 || !reg_set_p (info.sp_equiv_reg, insn)))
7228 if (! validate_replace_rtx (stack_pointer_rtx,
7229 plus_constant (info.sp_equiv_reg,
7236 else if (GET_CODE (PATTERN (insn)) == SET)
7237 handle_epilogue_set (PATTERN (insn), &info);
7238 else if (GET_CODE (PATTERN (insn)) == PARALLEL)
7240 for (j = 0; j < XVECLEN (PATTERN (insn), 0); j++)
7241 if (GET_CODE (XVECEXP (PATTERN (insn), 0, j)) == SET)
7242 handle_epilogue_set (XVECEXP (PATTERN (insn), 0, j), &info);
7247 info.sp_equiv_reg = info.new_sp_equiv_reg;
7248 info.sp_offset = info.new_sp_offset;
7250 /* Now update any constants this insn sets. */
7251 note_stores (PATTERN (insn), update_epilogue_consts, &info);
7255 insns = get_insns ();
7260 /* SET is a SET from an insn in the epilogue. P is a pointer to the epi_info
7261 structure that contains information about what we've seen so far. We
7262 process this SET by either updating that data or by emitting one or
7266 handle_epilogue_set (rtx set, struct epi_info *p)
7268 /* First handle the case where we are setting SP. Record what it is being
7269 set from. If unknown, abort. */
7270 if (reg_set_p (stack_pointer_rtx, set))
7272 if (SET_DEST (set) != stack_pointer_rtx)
7275 if (GET_CODE (SET_SRC (set)) == PLUS)
7277 p->new_sp_equiv_reg = XEXP (SET_SRC (set), 0);
7278 if (GET_CODE (XEXP (SET_SRC (set), 1)) == CONST_INT)
7279 p->new_sp_offset = INTVAL (XEXP (SET_SRC (set), 1));
7280 else if (REG_P (XEXP (SET_SRC (set), 1))
7281 && REGNO (XEXP (SET_SRC (set), 1)) < FIRST_PSEUDO_REGISTER
7282 && p->const_equiv[REGNO (XEXP (SET_SRC (set), 1))] != 0)
7284 = INTVAL (p->const_equiv[REGNO (XEXP (SET_SRC (set), 1))]);
7289 p->new_sp_equiv_reg = SET_SRC (set), p->new_sp_offset = 0;
7291 /* If we are adjusting SP, we adjust from the old data. */
7292 if (p->new_sp_equiv_reg == stack_pointer_rtx)
7294 p->new_sp_equiv_reg = p->sp_equiv_reg;
7295 p->new_sp_offset += p->sp_offset;
7298 if (p->new_sp_equiv_reg == 0 || !REG_P (p->new_sp_equiv_reg))
7304 /* Next handle the case where we are setting SP's equivalent register.
7305 If we already have a value to set it to, abort. We could update, but
7306 there seems little point in handling that case. Note that we have
7307 to allow for the case where we are setting the register set in
7308 the previous part of a PARALLEL inside a single insn. But use the
7309 old offset for any updates within this insn. We must allow for the case
7310 where the register is being set in a different (usually wider) mode than
7312 else if (p->new_sp_equiv_reg != 0 && reg_set_p (p->new_sp_equiv_reg, set))
7314 if (p->equiv_reg_src != 0
7315 || !REG_P (p->new_sp_equiv_reg)
7316 || !REG_P (SET_DEST (set))
7317 || GET_MODE_BITSIZE (GET_MODE (SET_DEST (set))) > BITS_PER_WORD
7318 || REGNO (p->new_sp_equiv_reg) != REGNO (SET_DEST (set)))
7322 = simplify_replace_rtx (SET_SRC (set), stack_pointer_rtx,
7323 plus_constant (p->sp_equiv_reg,
7327 /* Otherwise, replace any references to SP in the insn to its new value
7328 and emit the insn. */
7331 SET_SRC (set) = simplify_replace_rtx (SET_SRC (set), stack_pointer_rtx,
7332 plus_constant (p->sp_equiv_reg,
7334 SET_DEST (set) = simplify_replace_rtx (SET_DEST (set), stack_pointer_rtx,
7335 plus_constant (p->sp_equiv_reg,
7341 /* Update the tracking information for registers set to constants. */
7344 update_epilogue_consts (rtx dest, rtx x, void *data)
7346 struct epi_info *p = (struct epi_info *) data;
7349 if (!REG_P (dest) || REGNO (dest) >= FIRST_PSEUDO_REGISTER)
7352 /* If we are either clobbering a register or doing a partial set,
7353 show we don't know the value. */
7354 else if (GET_CODE (x) == CLOBBER || ! rtx_equal_p (dest, SET_DEST (x)))
7355 p->const_equiv[REGNO (dest)] = 0;
7357 /* If we are setting it to a constant, record that constant. */
7358 else if (GET_CODE (SET_SRC (x)) == CONST_INT)
7359 p->const_equiv[REGNO (dest)] = SET_SRC (x);
7361 /* If this is a binary operation between a register we have been tracking
7362 and a constant, see if we can compute a new constant value. */
7363 else if (ARITHMETIC_P (SET_SRC (x))
7364 && REG_P (XEXP (SET_SRC (x), 0))
7365 && REGNO (XEXP (SET_SRC (x), 0)) < FIRST_PSEUDO_REGISTER
7366 && p->const_equiv[REGNO (XEXP (SET_SRC (x), 0))] != 0
7367 && GET_CODE (XEXP (SET_SRC (x), 1)) == CONST_INT
7368 && 0 != (new = simplify_binary_operation
7369 (GET_CODE (SET_SRC (x)), GET_MODE (dest),
7370 p->const_equiv[REGNO (XEXP (SET_SRC (x), 0))],
7371 XEXP (SET_SRC (x), 1)))
7372 && GET_CODE (new) == CONST_INT)
7373 p->const_equiv[REGNO (dest)] = new;
7375 /* Otherwise, we can't do anything with this value. */
7377 p->const_equiv[REGNO (dest)] = 0;
7380 /* Emit an insn to do the load shown in p->equiv_reg_src, if needed. */
7383 emit_equiv_load (struct epi_info *p)
7385 if (p->equiv_reg_src != 0)
7387 rtx dest = p->sp_equiv_reg;
7389 if (GET_MODE (p->equiv_reg_src) != GET_MODE (dest))
7390 dest = gen_rtx_REG (GET_MODE (p->equiv_reg_src),
7391 REGNO (p->sp_equiv_reg));
7393 emit_move_insn (dest, p->equiv_reg_src);
7394 p->equiv_reg_src = 0;
7399 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
7400 this into place with notes indicating where the prologue ends and where
7401 the epilogue begins. Update the basic block information when possible. */
7404 thread_prologue_and_epilogue_insns (rtx f ATTRIBUTE_UNUSED)
7408 #if defined (HAVE_sibcall_epilogue) || defined (HAVE_epilogue) || defined (HAVE_return) || defined (HAVE_prologue)
7411 #ifdef HAVE_prologue
7412 rtx prologue_end = NULL_RTX;
7414 #if defined (HAVE_epilogue) || defined(HAVE_return)
7415 rtx epilogue_end = NULL_RTX;
7418 #ifdef HAVE_prologue
7422 seq = gen_prologue ();
7425 /* Retain a map of the prologue insns. */
7426 record_insns (seq, &prologue);
7427 prologue_end = emit_note (NOTE_INSN_PROLOGUE_END);
7431 set_insn_locators (seq, prologue_locator);
7433 /* Can't deal with multiple successors of the entry block
7434 at the moment. Function should always have at least one
7436 if (!ENTRY_BLOCK_PTR->succ || ENTRY_BLOCK_PTR->succ->succ_next)
7439 insert_insn_on_edge (seq, ENTRY_BLOCK_PTR->succ);
7444 /* If the exit block has no non-fake predecessors, we don't need
7446 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7447 if ((e->flags & EDGE_FAKE) == 0)
7453 if (optimize && HAVE_return)
7455 /* If we're allowed to generate a simple return instruction,
7456 then by definition we don't need a full epilogue. Examine
7457 the block that falls through to EXIT. If it does not
7458 contain any code, examine its predecessors and try to
7459 emit (conditional) return instructions. */
7465 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7466 if (e->flags & EDGE_FALLTHRU)
7472 /* Verify that there are no active instructions in the last block. */
7473 label = BB_END (last);
7474 while (label && GET_CODE (label) != CODE_LABEL)
7476 if (active_insn_p (label))
7478 label = PREV_INSN (label);
7481 if (BB_HEAD (last) == label && GET_CODE (label) == CODE_LABEL)
7483 rtx epilogue_line_note = NULL_RTX;
7485 /* Locate the line number associated with the closing brace,
7486 if we can find one. */
7487 for (seq = get_last_insn ();
7488 seq && ! active_insn_p (seq);
7489 seq = PREV_INSN (seq))
7490 if (GET_CODE (seq) == NOTE && NOTE_LINE_NUMBER (seq) > 0)
7492 epilogue_line_note = seq;
7496 for (e = last->pred; e; e = e_next)
7498 basic_block bb = e->src;
7501 e_next = e->pred_next;
7502 if (bb == ENTRY_BLOCK_PTR)
7506 if ((GET_CODE (jump) != JUMP_INSN) || JUMP_LABEL (jump) != label)
7509 /* If we have an unconditional jump, we can replace that
7510 with a simple return instruction. */
7511 if (simplejump_p (jump))
7513 emit_return_into_block (bb, epilogue_line_note);
7517 /* If we have a conditional jump, we can try to replace
7518 that with a conditional return instruction. */
7519 else if (condjump_p (jump))
7521 if (! redirect_jump (jump, 0, 0))
7524 /* If this block has only one successor, it both jumps
7525 and falls through to the fallthru block, so we can't
7527 if (bb->succ->succ_next == NULL)
7533 /* Fix up the CFG for the successful change we just made. */
7534 redirect_edge_succ (e, EXIT_BLOCK_PTR);
7537 /* Emit a return insn for the exit fallthru block. Whether
7538 this is still reachable will be determined later. */
7540 emit_barrier_after (BB_END (last));
7541 emit_return_into_block (last, epilogue_line_note);
7542 epilogue_end = BB_END (last);
7543 last->succ->flags &= ~EDGE_FALLTHRU;
7548 /* Find the edge that falls through to EXIT. Other edges may exist
7549 due to RETURN instructions, but those don't need epilogues.
7550 There really shouldn't be a mixture -- either all should have
7551 been converted or none, however... */
7553 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7554 if (e->flags & EDGE_FALLTHRU)
7559 #ifdef HAVE_epilogue
7563 epilogue_end = emit_note (NOTE_INSN_EPILOGUE_BEG);
7565 seq = gen_epilogue ();
7567 #ifdef INCOMING_RETURN_ADDR_RTX
7568 /* If this function returns with the stack depressed and we can support
7569 it, massage the epilogue to actually do that. */
7570 if (TREE_CODE (TREE_TYPE (current_function_decl)) == FUNCTION_TYPE
7571 && TYPE_RETURNS_STACK_DEPRESSED (TREE_TYPE (current_function_decl)))
7572 seq = keep_stack_depressed (seq);
7575 emit_jump_insn (seq);
7577 /* Retain a map of the epilogue insns. */
7578 record_insns (seq, &epilogue);
7579 set_insn_locators (seq, epilogue_locator);
7584 insert_insn_on_edge (seq, e);
7592 if (! next_active_insn (BB_END (e->src)))
7594 /* We have a fall-through edge to the exit block, the source is not
7595 at the end of the function, and there will be an assembler epilogue
7596 at the end of the function.
7597 We can't use force_nonfallthru here, because that would try to
7598 use return. Inserting a jump 'by hand' is extremely messy, so
7599 we take advantage of cfg_layout_finalize using
7600 fixup_fallthru_exit_predecessor. */
7601 cfg_layout_initialize ();
7602 FOR_EACH_BB (cur_bb)
7603 if (cur_bb->index >= 0 && cur_bb->next_bb->index >= 0)
7604 cur_bb->rbi->next = cur_bb->next_bb;
7605 cfg_layout_finalize ();
7610 commit_edge_insertions ();
7612 #ifdef HAVE_sibcall_epilogue
7613 /* Emit sibling epilogues before any sibling call sites. */
7614 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7616 basic_block bb = e->src;
7617 rtx insn = BB_END (bb);
7621 if (GET_CODE (insn) != CALL_INSN
7622 || ! SIBLING_CALL_P (insn))
7626 emit_insn (gen_sibcall_epilogue ());
7630 /* Retain a map of the epilogue insns. Used in life analysis to
7631 avoid getting rid of sibcall epilogue insns. Do this before we
7632 actually emit the sequence. */
7633 record_insns (seq, &sibcall_epilogue);
7634 set_insn_locators (seq, epilogue_locator);
7636 i = PREV_INSN (insn);
7637 newinsn = emit_insn_before (seq, insn);
7641 #ifdef HAVE_prologue
7642 /* This is probably all useless now that we use locators. */
7647 /* GDB handles `break f' by setting a breakpoint on the first
7648 line note after the prologue. Which means (1) that if
7649 there are line number notes before where we inserted the
7650 prologue we should move them, and (2) we should generate a
7651 note before the end of the first basic block, if there isn't
7654 ??? This behavior is completely broken when dealing with
7655 multiple entry functions. We simply place the note always
7656 into first basic block and let alternate entry points
7660 for (insn = prologue_end; insn; insn = prev)
7662 prev = PREV_INSN (insn);
7663 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
7665 /* Note that we cannot reorder the first insn in the
7666 chain, since rest_of_compilation relies on that
7667 remaining constant. */
7670 reorder_insns (insn, insn, prologue_end);
7674 /* Find the last line number note in the first block. */
7675 for (insn = BB_END (ENTRY_BLOCK_PTR->next_bb);
7676 insn != prologue_end && insn;
7677 insn = PREV_INSN (insn))
7678 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
7681 /* If we didn't find one, make a copy of the first line number
7685 for (insn = next_active_insn (prologue_end);
7687 insn = PREV_INSN (insn))
7688 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
7690 emit_note_copy_after (insn, prologue_end);
7696 #ifdef HAVE_epilogue
7701 /* Similarly, move any line notes that appear after the epilogue.
7702 There is no need, however, to be quite so anal about the existence
7703 of such a note. Also move the NOTE_INSN_FUNCTION_END and (possibly)
7704 NOTE_INSN_FUNCTION_BEG notes, as those can be relevant for debug
7706 for (insn = epilogue_end; insn; insn = next)
7708 next = NEXT_INSN (insn);
7709 if (GET_CODE (insn) == NOTE
7710 && (NOTE_LINE_NUMBER (insn) > 0
7711 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_BEG
7712 || NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_END))
7713 reorder_insns (insn, insn, PREV_INSN (epilogue_end));
7719 /* Reposition the prologue-end and epilogue-begin notes after instruction
7720 scheduling and delayed branch scheduling. */
7723 reposition_prologue_and_epilogue_notes (rtx f ATTRIBUTE_UNUSED)
7725 #if defined (HAVE_prologue) || defined (HAVE_epilogue)
7726 rtx insn, last, note;
7729 if ((len = VARRAY_SIZE (prologue)) > 0)
7733 /* Scan from the beginning until we reach the last prologue insn.
7734 We apparently can't depend on basic_block_{head,end} after
7736 for (insn = f; insn; insn = NEXT_INSN (insn))
7738 if (GET_CODE (insn) == NOTE)
7740 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_PROLOGUE_END)
7743 else if (contains (insn, prologue))
7753 /* Find the prologue-end note if we haven't already, and
7754 move it to just after the last prologue insn. */
7757 for (note = last; (note = NEXT_INSN (note));)
7758 if (GET_CODE (note) == NOTE
7759 && NOTE_LINE_NUMBER (note) == NOTE_INSN_PROLOGUE_END)
7763 /* Avoid placing note between CODE_LABEL and BASIC_BLOCK note. */
7764 if (GET_CODE (last) == CODE_LABEL)
7765 last = NEXT_INSN (last);
7766 reorder_insns (note, note, last);
7770 if ((len = VARRAY_SIZE (epilogue)) > 0)
7774 /* Scan from the end until we reach the first epilogue insn.
7775 We apparently can't depend on basic_block_{head,end} after
7777 for (insn = get_last_insn (); insn; insn = PREV_INSN (insn))
7779 if (GET_CODE (insn) == NOTE)
7781 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EPILOGUE_BEG)
7784 else if (contains (insn, epilogue))
7794 /* Find the epilogue-begin note if we haven't already, and
7795 move it to just before the first epilogue insn. */
7798 for (note = insn; (note = PREV_INSN (note));)
7799 if (GET_CODE (note) == NOTE
7800 && NOTE_LINE_NUMBER (note) == NOTE_INSN_EPILOGUE_BEG)
7804 if (PREV_INSN (last) != note)
7805 reorder_insns (note, note, PREV_INSN (last));
7808 #endif /* HAVE_prologue or HAVE_epilogue */
7811 /* Called once, at initialization, to initialize function.c. */
7814 init_function_once (void)
7816 VARRAY_INT_INIT (prologue, 0, "prologue");
7817 VARRAY_INT_INIT (epilogue, 0, "epilogue");
7818 VARRAY_INT_INIT (sibcall_epilogue, 0, "sibcall_epilogue");
7821 /* Resets insn_block_boundaries array. */
7824 reset_block_changes (void)
7826 VARRAY_TREE_INIT (cfun->ib_boundaries_block, 100, "ib_boundaries_block");
7827 VARRAY_PUSH_TREE (cfun->ib_boundaries_block, NULL_TREE);
7830 /* Record the boundary for BLOCK. */
7832 record_block_change (tree block)
7840 last_block = VARRAY_TOP_TREE (cfun->ib_boundaries_block);
7841 VARRAY_POP (cfun->ib_boundaries_block);
7843 for (i = VARRAY_ACTIVE_SIZE (cfun->ib_boundaries_block); i < n; i++)
7844 VARRAY_PUSH_TREE (cfun->ib_boundaries_block, last_block);
7846 VARRAY_PUSH_TREE (cfun->ib_boundaries_block, block);
7849 /* Finishes record of boundaries. */
7850 void finalize_block_changes (void)
7852 record_block_change (DECL_INITIAL (current_function_decl));
7855 /* For INSN return the BLOCK it belongs to. */
7857 check_block_change (rtx insn, tree *block)
7859 unsigned uid = INSN_UID (insn);
7861 if (uid >= VARRAY_ACTIVE_SIZE (cfun->ib_boundaries_block))
7864 *block = VARRAY_TREE (cfun->ib_boundaries_block, uid);
7867 /* Releases the ib_boundaries_block records. */
7869 free_block_changes (void)
7871 cfun->ib_boundaries_block = NULL;
7874 /* Returns the name of the current function. */
7876 current_function_name (void)
7878 return lang_hooks.decl_printable_name (cfun->decl, 2);
7881 #include "gt-function.h"