1 /* Expands front end tree to back end RTL for GNU C-Compiler
2 Copyright (C) 1987, 1988, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000 Free Software Foundation, Inc.
5 This file is part of GNU CC.
7 GNU CC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU CC; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
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. */
48 #include "insn-flags.h"
50 #include "insn-codes.h"
52 #include "hard-reg-set.h"
53 #include "insn-config.h"
56 #include "basic-block.h"
63 #ifndef ACCUMULATE_OUTGOING_ARGS
64 #define ACCUMULATE_OUTGOING_ARGS 0
67 #ifndef TRAMPOLINE_ALIGNMENT
68 #define TRAMPOLINE_ALIGNMENT FUNCTION_BOUNDARY
71 #ifndef LOCAL_ALIGNMENT
72 #define LOCAL_ALIGNMENT(TYPE, ALIGNMENT) ALIGNMENT
75 #if !defined (PREFERRED_STACK_BOUNDARY) && defined (STACK_BOUNDARY)
76 #define PREFERRED_STACK_BOUNDARY STACK_BOUNDARY
79 /* Some systems use __main in a way incompatible with its use in gcc, in these
80 cases use the macros NAME__MAIN to give a quoted symbol and SYMBOL__MAIN to
81 give the same symbol without quotes for an alternative entry point. You
82 must define both, or neither. */
84 #define NAME__MAIN "__main"
85 #define SYMBOL__MAIN __main
88 /* Round a value to the lowest integer less than it that is a multiple of
89 the required alignment. Avoid using division in case the value is
90 negative. Assume the alignment is a power of two. */
91 #define FLOOR_ROUND(VALUE,ALIGN) ((VALUE) & ~((ALIGN) - 1))
93 /* Similar, but round to the next highest integer that meets the
95 #define CEIL_ROUND(VALUE,ALIGN) (((VALUE) + (ALIGN) - 1) & ~((ALIGN)- 1))
97 /* NEED_SEPARATE_AP means that we cannot derive ap from the value of fp
98 during rtl generation. If they are different register numbers, this is
99 always true. It may also be true if
100 FIRST_PARM_OFFSET - STARTING_FRAME_OFFSET is not a constant during rtl
101 generation. See fix_lexical_addr for details. */
103 #if ARG_POINTER_REGNUM != FRAME_POINTER_REGNUM
104 #define NEED_SEPARATE_AP
107 /* Nonzero if function being compiled doesn't contain any calls
108 (ignoring the prologue and epilogue). This is set prior to
109 local register allocation and is valid for the remaining
111 int current_function_is_leaf;
113 /* Nonzero if function being compiled doesn't contain any instructions
114 that can throw an exception. This is set prior to final. */
116 int current_function_nothrow;
118 /* Nonzero if function being compiled doesn't modify the stack pointer
119 (ignoring the prologue and epilogue). This is only valid after
120 life_analysis has run. */
121 int current_function_sp_is_unchanging;
123 /* Nonzero if the function being compiled is a leaf function which only
124 uses leaf registers. This is valid after reload (specifically after
125 sched2) and is useful only if the port defines LEAF_REGISTERS. */
126 int current_function_uses_only_leaf_regs;
128 /* Nonzero once virtual register instantiation has been done.
129 assign_stack_local uses frame_pointer_rtx when this is nonzero. */
130 static int virtuals_instantiated;
132 /* These variables hold pointers to functions to
133 save and restore machine-specific data,
134 in push_function_context and pop_function_context. */
135 void (*init_machine_status) PARAMS ((struct function *));
136 void (*save_machine_status) PARAMS ((struct function *));
137 void (*restore_machine_status) PARAMS ((struct function *));
138 void (*mark_machine_status) PARAMS ((struct function *));
139 void (*free_machine_status) PARAMS ((struct function *));
141 /* Likewise, but for language-specific data. */
142 void (*init_lang_status) PARAMS ((struct function *));
143 void (*save_lang_status) PARAMS ((struct function *));
144 void (*restore_lang_status) PARAMS ((struct function *));
145 void (*mark_lang_status) PARAMS ((struct function *));
146 void (*free_lang_status) PARAMS ((struct function *));
148 /* The FUNCTION_DECL for an inline function currently being expanded. */
149 tree inline_function_decl;
151 /* The currently compiled function. */
152 struct function *cfun = 0;
154 /* Global list of all compiled functions. */
155 struct function *all_functions = 0;
157 /* These arrays record the INSN_UIDs of the prologue and epilogue insns. */
158 static varray_type prologue;
159 static varray_type epilogue;
161 /* Array of INSN_UIDs to hold the INSN_UIDs for each sibcall epilogue
163 static varray_type sibcall_epilogue;
165 /* In order to evaluate some expressions, such as function calls returning
166 structures in memory, we need to temporarily allocate stack locations.
167 We record each allocated temporary in the following structure.
169 Associated with each temporary slot is a nesting level. When we pop up
170 one level, all temporaries associated with the previous level are freed.
171 Normally, all temporaries are freed after the execution of the statement
172 in which they were created. However, if we are inside a ({...}) grouping,
173 the result may be in a temporary and hence must be preserved. If the
174 result could be in a temporary, we preserve it if we can determine which
175 one it is in. If we cannot determine which temporary may contain the
176 result, all temporaries are preserved. A temporary is preserved by
177 pretending it was allocated at the previous nesting level.
179 Automatic variables are also assigned temporary slots, at the nesting
180 level where they are defined. They are marked a "kept" so that
181 free_temp_slots will not free them. */
185 /* Points to next temporary slot. */
186 struct temp_slot *next;
187 /* The rtx to used to reference the slot. */
189 /* The rtx used to represent the address if not the address of the
190 slot above. May be an EXPR_LIST if multiple addresses exist. */
192 /* The alignment (in bits) of the slot. */
194 /* The size, in units, of the slot. */
196 /* The alias set for the slot. If the alias set is zero, we don't
197 know anything about the alias set of the slot. We must only
198 reuse a slot if it is assigned an object of the same alias set.
199 Otherwise, the rest of the compiler may assume that the new use
200 of the slot cannot alias the old use of the slot, which is
201 false. If the slot has alias set zero, then we can't reuse the
202 slot at all, since we have no idea what alias set may have been
203 imposed on the memory. For example, if the stack slot is the
204 call frame for an inline functioned, we have no idea what alias
205 sets will be assigned to various pieces of the call frame. */
206 HOST_WIDE_INT alias_set;
207 /* The value of `sequence_rtl_expr' when this temporary is allocated. */
209 /* Non-zero if this temporary is currently in use. */
211 /* Non-zero if this temporary has its address taken. */
213 /* Nesting level at which this slot is being used. */
215 /* Non-zero if this should survive a call to free_temp_slots. */
217 /* The offset of the slot from the frame_pointer, including extra space
218 for alignment. This info is for combine_temp_slots. */
219 HOST_WIDE_INT base_offset;
220 /* The size of the slot, including extra space for alignment. This
221 info is for combine_temp_slots. */
222 HOST_WIDE_INT full_size;
225 /* This structure is used to record MEMs or pseudos used to replace VAR, any
226 SUBREGs of VAR, and any MEMs containing VAR as an address. We need to
227 maintain this list in case two operands of an insn were required to match;
228 in that case we must ensure we use the same replacement. */
230 struct fixup_replacement
234 struct fixup_replacement *next;
237 struct insns_for_mem_entry {
238 /* The KEY in HE will be a MEM. */
239 struct hash_entry he;
240 /* These are the INSNS which reference the MEM. */
244 /* Forward declarations. */
246 static rtx assign_stack_local_1 PARAMS ((enum machine_mode, HOST_WIDE_INT,
247 int, struct function *));
248 static rtx assign_stack_temp_for_type PARAMS ((enum machine_mode,
249 HOST_WIDE_INT, int, tree));
250 static struct temp_slot *find_temp_slot_from_address PARAMS ((rtx));
251 static void put_reg_into_stack PARAMS ((struct function *, rtx, tree,
252 enum machine_mode, enum machine_mode,
253 int, unsigned int, int,
254 struct hash_table *));
255 static void schedule_fixup_var_refs PARAMS ((struct function *, rtx, tree,
257 struct hash_table *));
258 static void fixup_var_refs PARAMS ((rtx, enum machine_mode, int,
259 struct hash_table *));
260 static struct fixup_replacement
261 *find_fixup_replacement PARAMS ((struct fixup_replacement **, rtx));
262 static void fixup_var_refs_insns PARAMS ((rtx, enum machine_mode, int,
263 rtx, int, struct hash_table *));
264 static void fixup_var_refs_1 PARAMS ((rtx, enum machine_mode, rtx *, rtx,
265 struct fixup_replacement **));
266 static rtx fixup_memory_subreg PARAMS ((rtx, rtx, int));
267 static rtx walk_fixup_memory_subreg PARAMS ((rtx, rtx, int));
268 static rtx fixup_stack_1 PARAMS ((rtx, rtx));
269 static void optimize_bit_field PARAMS ((rtx, rtx, rtx *));
270 static void instantiate_decls PARAMS ((tree, int));
271 static void instantiate_decls_1 PARAMS ((tree, int));
272 static void instantiate_decl PARAMS ((rtx, HOST_WIDE_INT, int));
273 static int instantiate_virtual_regs_1 PARAMS ((rtx *, rtx, int));
274 static void delete_handlers PARAMS ((void));
275 static void pad_to_arg_alignment PARAMS ((struct args_size *, int,
276 struct args_size *));
277 #ifndef ARGS_GROW_DOWNWARD
278 static void pad_below PARAMS ((struct args_size *, enum machine_mode,
281 static rtx round_trampoline_addr PARAMS ((rtx));
282 static tree *identify_blocks_1 PARAMS ((rtx, tree *, tree *, tree *));
283 static void reorder_blocks_1 PARAMS ((rtx, tree, varray_type *));
284 static tree blocks_nreverse PARAMS ((tree));
285 static int all_blocks PARAMS ((tree, tree *));
286 static tree *get_block_vector PARAMS ((tree, int *));
287 /* We always define `record_insns' even if its not used so that we
288 can always export `prologue_epilogue_contains'. */
289 static void record_insns PARAMS ((rtx, varray_type *)) ATTRIBUTE_UNUSED;
290 static int contains PARAMS ((rtx, varray_type));
292 static void emit_return_into_block PARAMS ((basic_block, rtx));
294 static void put_addressof_into_stack PARAMS ((rtx, struct hash_table *));
295 static boolean purge_addressof_1 PARAMS ((rtx *, rtx, int, int,
296 struct hash_table *));
298 static void keep_stack_depressed PARAMS ((rtx));
300 static int is_addressof PARAMS ((rtx *, void *));
301 static struct hash_entry *insns_for_mem_newfunc PARAMS ((struct hash_entry *,
304 static unsigned long insns_for_mem_hash PARAMS ((hash_table_key));
305 static boolean insns_for_mem_comp PARAMS ((hash_table_key, hash_table_key));
306 static int insns_for_mem_walk PARAMS ((rtx *, void *));
307 static void compute_insns_for_mem PARAMS ((rtx, rtx, struct hash_table *));
308 static void mark_temp_slot PARAMS ((struct temp_slot *));
309 static void mark_function_status PARAMS ((struct function *));
310 static void mark_function_chain PARAMS ((void *));
311 static void prepare_function_start PARAMS ((void));
312 static void do_clobber_return_reg PARAMS ((rtx, void *));
313 static void do_use_return_reg PARAMS ((rtx, void *));
315 /* Pointer to chain of `struct function' for containing functions. */
316 struct function *outer_function_chain;
318 /* Given a function decl for a containing function,
319 return the `struct function' for it. */
322 find_function_data (decl)
327 for (p = outer_function_chain; p; p = p->next)
334 /* Save the current context for compilation of a nested function.
335 This is called from language-specific code. The caller should use
336 the save_lang_status callback to save any language-specific state,
337 since this function knows only about language-independent
341 push_function_context_to (context)
344 struct function *p, *context_data;
348 context_data = (context == current_function_decl
350 : find_function_data (context));
351 context_data->contains_functions = 1;
355 init_dummy_function_start ();
358 p->next = outer_function_chain;
359 outer_function_chain = p;
360 p->fixup_var_refs_queue = 0;
362 save_tree_status (p);
363 if (save_lang_status)
364 (*save_lang_status) (p);
365 if (save_machine_status)
366 (*save_machine_status) (p);
372 push_function_context ()
374 push_function_context_to (current_function_decl);
377 /* Restore the last saved context, at the end of a nested function.
378 This function is called from language-specific code. */
381 pop_function_context_from (context)
382 tree context ATTRIBUTE_UNUSED;
384 struct function *p = outer_function_chain;
385 struct var_refs_queue *queue;
386 struct var_refs_queue *next;
389 outer_function_chain = p->next;
391 current_function_decl = p->decl;
394 restore_tree_status (p);
395 restore_emit_status (p);
397 if (restore_machine_status)
398 (*restore_machine_status) (p);
399 if (restore_lang_status)
400 (*restore_lang_status) (p);
402 /* Finish doing put_var_into_stack for any of our variables
403 which became addressable during the nested function. */
404 for (queue = p->fixup_var_refs_queue; queue; queue = next)
407 fixup_var_refs (queue->modified, queue->promoted_mode,
408 queue->unsignedp, 0);
411 p->fixup_var_refs_queue = 0;
413 /* Reset variables that have known state during rtx generation. */
414 rtx_equal_function_value_matters = 1;
415 virtuals_instantiated = 0;
419 pop_function_context ()
421 pop_function_context_from (current_function_decl);
424 /* Clear out all parts of the state in F that can safely be discarded
425 after the function has been parsed, but not compiled, to let
426 garbage collection reclaim the memory. */
429 free_after_parsing (f)
432 /* f->expr->forced_labels is used by code generation. */
433 /* f->emit->regno_reg_rtx is used by code generation. */
434 /* f->varasm is used by code generation. */
435 /* f->eh->eh_return_stub_label is used by code generation. */
437 if (free_lang_status)
438 (*free_lang_status) (f);
439 free_stmt_status (f);
442 /* Clear out all parts of the state in F that can safely be discarded
443 after the function has been compiled, to let garbage collection
444 reclaim the memory. */
447 free_after_compilation (f)
450 struct temp_slot *ts;
451 struct temp_slot *next;
454 free_expr_status (f);
455 free_emit_status (f);
456 free_varasm_status (f);
458 if (free_machine_status)
459 (*free_machine_status) (f);
461 if (f->x_parm_reg_stack_loc)
462 free (f->x_parm_reg_stack_loc);
464 for (ts = f->x_temp_slots; ts; ts = next)
469 f->x_temp_slots = NULL;
471 f->arg_offset_rtx = NULL;
472 f->return_rtx = NULL;
473 f->internal_arg_pointer = NULL;
474 f->x_nonlocal_labels = NULL;
475 f->x_nonlocal_goto_handler_slots = NULL;
476 f->x_nonlocal_goto_handler_labels = NULL;
477 f->x_nonlocal_goto_stack_level = NULL;
478 f->x_cleanup_label = NULL;
479 f->x_return_label = NULL;
480 f->x_save_expr_regs = NULL;
481 f->x_stack_slot_list = NULL;
482 f->x_rtl_expr_chain = NULL;
483 f->x_tail_recursion_label = NULL;
484 f->x_tail_recursion_reentry = NULL;
485 f->x_arg_pointer_save_area = NULL;
486 f->x_context_display = NULL;
487 f->x_trampoline_list = NULL;
488 f->x_parm_birth_insn = NULL;
489 f->x_last_parm_insn = NULL;
490 f->x_parm_reg_stack_loc = NULL;
491 f->fixup_var_refs_queue = NULL;
492 f->original_arg_vector = NULL;
493 f->original_decl_initial = NULL;
494 f->inl_last_parm_insn = NULL;
495 f->epilogue_delay_list = NULL;
498 /* Allocate fixed slots in the stack frame of the current function. */
500 /* Return size needed for stack frame based on slots so far allocated in
502 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
503 the caller may have to do that. */
506 get_func_frame_size (f)
509 #ifdef FRAME_GROWS_DOWNWARD
510 return -f->x_frame_offset;
512 return f->x_frame_offset;
516 /* Return size needed for stack frame based on slots so far allocated.
517 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
518 the caller may have to do that. */
522 return get_func_frame_size (cfun);
525 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
526 with machine mode MODE.
528 ALIGN controls the amount of alignment for the address of the slot:
529 0 means according to MODE,
530 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
531 positive specifies alignment boundary in bits.
533 We do not round to stack_boundary here.
535 FUNCTION specifies the function to allocate in. */
538 assign_stack_local_1 (mode, size, align, function)
539 enum machine_mode mode;
542 struct function *function;
544 register rtx x, addr;
545 int bigend_correction = 0;
548 /* Allocate in the memory associated with the function in whose frame
550 if (function != cfun)
551 push_obstacks (function->function_obstack,
552 function->function_maybepermanent_obstack);
559 alignment = BIGGEST_ALIGNMENT;
561 alignment = GET_MODE_ALIGNMENT (mode);
563 /* Allow the target to (possibly) increase the alignment of this
565 type = type_for_mode (mode, 0);
567 alignment = LOCAL_ALIGNMENT (type, alignment);
569 alignment /= BITS_PER_UNIT;
571 else if (align == -1)
573 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
574 size = CEIL_ROUND (size, alignment);
577 alignment = align / BITS_PER_UNIT;
579 #ifdef FRAME_GROWS_DOWNWARD
580 function->x_frame_offset -= size;
583 /* Ignore alignment we can't do with expected alignment of the boundary. */
584 if (alignment * BITS_PER_UNIT > PREFERRED_STACK_BOUNDARY)
585 alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
587 if (function->stack_alignment_needed < alignment * BITS_PER_UNIT)
588 function->stack_alignment_needed = alignment * BITS_PER_UNIT;
590 /* Round frame offset to that alignment.
591 We must be careful here, since FRAME_OFFSET might be negative and
592 division with a negative dividend isn't as well defined as we might
593 like. So we instead assume that ALIGNMENT is a power of two and
594 use logical operations which are unambiguous. */
595 #ifdef FRAME_GROWS_DOWNWARD
596 function->x_frame_offset = FLOOR_ROUND (function->x_frame_offset, alignment);
598 function->x_frame_offset = CEIL_ROUND (function->x_frame_offset, alignment);
601 /* On a big-endian machine, if we are allocating more space than we will use,
602 use the least significant bytes of those that are allocated. */
603 if (BYTES_BIG_ENDIAN && mode != BLKmode)
604 bigend_correction = size - GET_MODE_SIZE (mode);
606 /* If we have already instantiated virtual registers, return the actual
607 address relative to the frame pointer. */
608 if (function == cfun && virtuals_instantiated)
609 addr = plus_constant (frame_pointer_rtx,
610 (frame_offset + bigend_correction
611 + STARTING_FRAME_OFFSET));
613 addr = plus_constant (virtual_stack_vars_rtx,
614 function->x_frame_offset + bigend_correction);
616 #ifndef FRAME_GROWS_DOWNWARD
617 function->x_frame_offset += size;
620 x = gen_rtx_MEM (mode, addr);
622 function->x_stack_slot_list
623 = gen_rtx_EXPR_LIST (VOIDmode, x, function->x_stack_slot_list);
625 if (function != cfun)
631 /* Wrapper around assign_stack_local_1; assign a local stack slot for the
635 assign_stack_local (mode, size, align)
636 enum machine_mode mode;
640 return assign_stack_local_1 (mode, size, align, cfun);
643 /* Allocate a temporary stack slot and record it for possible later
646 MODE is the machine mode to be given to the returned rtx.
648 SIZE is the size in units of the space required. We do no rounding here
649 since assign_stack_local will do any required rounding.
651 KEEP is 1 if this slot is to be retained after a call to
652 free_temp_slots. Automatic variables for a block are allocated
653 with this flag. KEEP is 2 if we allocate a longer term temporary,
654 whose lifetime is controlled by CLEANUP_POINT_EXPRs. KEEP is 3
655 if we are to allocate something at an inner level to be treated as
656 a variable in the block (e.g., a SAVE_EXPR).
658 TYPE is the type that will be used for the stack slot. */
661 assign_stack_temp_for_type (mode, size, keep, type)
662 enum machine_mode mode;
668 HOST_WIDE_INT alias_set;
669 struct temp_slot *p, *best_p = 0;
671 /* If SIZE is -1 it means that somebody tried to allocate a temporary
672 of a variable size. */
676 /* If we know the alias set for the memory that will be used, use
677 it. If there's no TYPE, then we don't know anything about the
678 alias set for the memory. */
680 alias_set = get_alias_set (type);
685 align = BIGGEST_ALIGNMENT;
687 align = GET_MODE_ALIGNMENT (mode);
690 type = type_for_mode (mode, 0);
693 align = LOCAL_ALIGNMENT (type, align);
695 /* Try to find an available, already-allocated temporary of the proper
696 mode which meets the size and alignment requirements. Choose the
697 smallest one with the closest alignment. */
698 for (p = temp_slots; p; p = p->next)
699 if (p->align >= align && p->size >= size && GET_MODE (p->slot) == mode
701 && (! flag_strict_aliasing
702 || (alias_set && p->alias_set == alias_set))
703 && (best_p == 0 || best_p->size > p->size
704 || (best_p->size == p->size && best_p->align > p->align)))
706 if (p->align == align && p->size == size)
714 /* Make our best, if any, the one to use. */
717 /* If there are enough aligned bytes left over, make them into a new
718 temp_slot so that the extra bytes don't get wasted. Do this only
719 for BLKmode slots, so that we can be sure of the alignment. */
720 if (GET_MODE (best_p->slot) == BLKmode)
722 int alignment = best_p->align / BITS_PER_UNIT;
723 HOST_WIDE_INT rounded_size = CEIL_ROUND (size, alignment);
725 if (best_p->size - rounded_size >= alignment)
727 p = (struct temp_slot *) xmalloc (sizeof (struct temp_slot));
728 p->in_use = p->addr_taken = 0;
729 p->size = best_p->size - rounded_size;
730 p->base_offset = best_p->base_offset + rounded_size;
731 p->full_size = best_p->full_size - rounded_size;
732 p->slot = gen_rtx_MEM (BLKmode,
733 plus_constant (XEXP (best_p->slot, 0),
735 p->align = best_p->align;
738 p->alias_set = best_p->alias_set;
739 p->next = temp_slots;
742 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, p->slot,
745 best_p->size = rounded_size;
746 best_p->full_size = rounded_size;
753 /* If we still didn't find one, make a new temporary. */
756 HOST_WIDE_INT frame_offset_old = frame_offset;
758 p = (struct temp_slot *) xmalloc (sizeof (struct temp_slot));
760 /* We are passing an explicit alignment request to assign_stack_local.
761 One side effect of that is assign_stack_local will not round SIZE
762 to ensure the frame offset remains suitably aligned.
764 So for requests which depended on the rounding of SIZE, we go ahead
765 and round it now. We also make sure ALIGNMENT is at least
766 BIGGEST_ALIGNMENT. */
767 if (mode == BLKmode && align < BIGGEST_ALIGNMENT)
769 p->slot = assign_stack_local (mode,
771 ? CEIL_ROUND (size, align / BITS_PER_UNIT)
776 p->alias_set = alias_set;
778 /* The following slot size computation is necessary because we don't
779 know the actual size of the temporary slot until assign_stack_local
780 has performed all the frame alignment and size rounding for the
781 requested temporary. Note that extra space added for alignment
782 can be either above or below this stack slot depending on which
783 way the frame grows. We include the extra space if and only if it
784 is above this slot. */
785 #ifdef FRAME_GROWS_DOWNWARD
786 p->size = frame_offset_old - frame_offset;
791 /* Now define the fields used by combine_temp_slots. */
792 #ifdef FRAME_GROWS_DOWNWARD
793 p->base_offset = frame_offset;
794 p->full_size = frame_offset_old - frame_offset;
796 p->base_offset = frame_offset_old;
797 p->full_size = frame_offset - frame_offset_old;
800 p->next = temp_slots;
806 p->rtl_expr = seq_rtl_expr;
810 p->level = target_temp_slot_level;
815 p->level = var_temp_slot_level;
820 p->level = temp_slot_level;
824 /* We may be reusing an old slot, so clear any MEM flags that may have been
826 RTX_UNCHANGING_P (p->slot) = 0;
827 MEM_IN_STRUCT_P (p->slot) = 0;
828 MEM_SCALAR_P (p->slot) = 0;
829 MEM_ALIAS_SET (p->slot) = alias_set;
832 MEM_SET_IN_STRUCT_P (p->slot, AGGREGATE_TYPE_P (type));
837 /* Allocate a temporary stack slot and record it for possible later
838 reuse. First three arguments are same as in preceding function. */
841 assign_stack_temp (mode, size, keep)
842 enum machine_mode mode;
846 return assign_stack_temp_for_type (mode, size, keep, NULL_TREE);
849 /* Assign a temporary of given TYPE.
850 KEEP is as for assign_stack_temp.
851 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
852 it is 0 if a register is OK.
853 DONT_PROMOTE is 1 if we should not promote values in register
857 assign_temp (type, keep, memory_required, dont_promote)
861 int dont_promote ATTRIBUTE_UNUSED;
863 enum machine_mode mode = TYPE_MODE (type);
864 #ifndef PROMOTE_FOR_CALL_ONLY
865 int unsignedp = TREE_UNSIGNED (type);
868 if (mode == BLKmode || memory_required)
870 HOST_WIDE_INT size = int_size_in_bytes (type);
873 /* Zero sized arrays are GNU C extension. Set size to 1 to avoid
874 problems with allocating the stack space. */
878 /* Unfortunately, we don't yet know how to allocate variable-sized
879 temporaries. However, sometimes we have a fixed upper limit on
880 the size (which is stored in TYPE_ARRAY_MAX_SIZE) and can use that
881 instead. This is the case for Chill variable-sized strings. */
882 if (size == -1 && TREE_CODE (type) == ARRAY_TYPE
883 && TYPE_ARRAY_MAX_SIZE (type) != NULL_TREE
884 && host_integerp (TYPE_ARRAY_MAX_SIZE (type), 1))
885 size = tree_low_cst (TYPE_ARRAY_MAX_SIZE (type), 1);
887 tmp = assign_stack_temp_for_type (mode, size, keep, type);
891 #ifndef PROMOTE_FOR_CALL_ONLY
893 mode = promote_mode (type, mode, &unsignedp, 0);
896 return gen_reg_rtx (mode);
899 /* Combine temporary stack slots which are adjacent on the stack.
901 This allows for better use of already allocated stack space. This is only
902 done for BLKmode slots because we can be sure that we won't have alignment
903 problems in this case. */
906 combine_temp_slots ()
908 struct temp_slot *p, *q;
909 struct temp_slot *prev_p, *prev_q;
912 /* We can't combine slots, because the information about which slot
913 is in which alias set will be lost. */
914 if (flag_strict_aliasing)
917 /* If there are a lot of temp slots, don't do anything unless
918 high levels of optimizaton. */
919 if (! flag_expensive_optimizations)
920 for (p = temp_slots, num_slots = 0; p; p = p->next, num_slots++)
921 if (num_slots > 100 || (num_slots > 10 && optimize == 0))
924 for (p = temp_slots, prev_p = 0; p; p = prev_p ? prev_p->next : temp_slots)
928 if (! p->in_use && GET_MODE (p->slot) == BLKmode)
929 for (q = p->next, prev_q = p; q; q = prev_q->next)
932 if (! q->in_use && GET_MODE (q->slot) == BLKmode)
934 if (p->base_offset + p->full_size == q->base_offset)
936 /* Q comes after P; combine Q into P. */
938 p->full_size += q->full_size;
941 else if (q->base_offset + q->full_size == p->base_offset)
943 /* P comes after Q; combine P into Q. */
945 q->full_size += p->full_size;
950 /* Either delete Q or advance past it. */
953 prev_q->next = q->next;
959 /* Either delete P or advance past it. */
963 prev_p->next = p->next;
965 temp_slots = p->next;
972 /* Find the temp slot corresponding to the object at address X. */
974 static struct temp_slot *
975 find_temp_slot_from_address (x)
981 for (p = temp_slots; p; p = p->next)
986 else if (XEXP (p->slot, 0) == x
988 || (GET_CODE (x) == PLUS
989 && XEXP (x, 0) == virtual_stack_vars_rtx
990 && GET_CODE (XEXP (x, 1)) == CONST_INT
991 && INTVAL (XEXP (x, 1)) >= p->base_offset
992 && INTVAL (XEXP (x, 1)) < p->base_offset + p->full_size))
995 else if (p->address != 0 && GET_CODE (p->address) == EXPR_LIST)
996 for (next = p->address; next; next = XEXP (next, 1))
997 if (XEXP (next, 0) == x)
1001 /* If we have a sum involving a register, see if it points to a temp
1003 if (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 0)) == REG
1004 && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
1006 else if (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 1)) == REG
1007 && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
1013 /* Indicate that NEW is an alternate way of referring to the temp slot
1014 that previously was known by OLD. */
1017 update_temp_slot_address (old, new)
1020 struct temp_slot *p;
1022 if (rtx_equal_p (old, new))
1025 p = find_temp_slot_from_address (old);
1027 /* If we didn't find one, see if both OLD is a PLUS. If so, and NEW
1028 is a register, see if one operand of the PLUS is a temporary
1029 location. If so, NEW points into it. Otherwise, if both OLD and
1030 NEW are a PLUS and if there is a register in common between them.
1031 If so, try a recursive call on those values. */
1034 if (GET_CODE (old) != PLUS)
1037 if (GET_CODE (new) == REG)
1039 update_temp_slot_address (XEXP (old, 0), new);
1040 update_temp_slot_address (XEXP (old, 1), new);
1043 else if (GET_CODE (new) != PLUS)
1046 if (rtx_equal_p (XEXP (old, 0), XEXP (new, 0)))
1047 update_temp_slot_address (XEXP (old, 1), XEXP (new, 1));
1048 else if (rtx_equal_p (XEXP (old, 1), XEXP (new, 0)))
1049 update_temp_slot_address (XEXP (old, 0), XEXP (new, 1));
1050 else if (rtx_equal_p (XEXP (old, 0), XEXP (new, 1)))
1051 update_temp_slot_address (XEXP (old, 1), XEXP (new, 0));
1052 else if (rtx_equal_p (XEXP (old, 1), XEXP (new, 1)))
1053 update_temp_slot_address (XEXP (old, 0), XEXP (new, 0));
1058 /* Otherwise add an alias for the temp's address. */
1059 else if (p->address == 0)
1063 if (GET_CODE (p->address) != EXPR_LIST)
1064 p->address = gen_rtx_EXPR_LIST (VOIDmode, p->address, NULL_RTX);
1066 p->address = gen_rtx_EXPR_LIST (VOIDmode, new, p->address);
1070 /* If X could be a reference to a temporary slot, mark the fact that its
1071 address was taken. */
1074 mark_temp_addr_taken (x)
1077 struct temp_slot *p;
1082 /* If X is not in memory or is at a constant address, it cannot be in
1083 a temporary slot. */
1084 if (GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0)))
1087 p = find_temp_slot_from_address (XEXP (x, 0));
1092 /* If X could be a reference to a temporary slot, mark that slot as
1093 belonging to the to one level higher than the current level. If X
1094 matched one of our slots, just mark that one. Otherwise, we can't
1095 easily predict which it is, so upgrade all of them. Kept slots
1096 need not be touched.
1098 This is called when an ({...}) construct occurs and a statement
1099 returns a value in memory. */
1102 preserve_temp_slots (x)
1105 struct temp_slot *p = 0;
1107 /* If there is no result, we still might have some objects whose address
1108 were taken, so we need to make sure they stay around. */
1111 for (p = temp_slots; p; p = p->next)
1112 if (p->in_use && p->level == temp_slot_level && p->addr_taken)
1118 /* If X is a register that is being used as a pointer, see if we have
1119 a temporary slot we know it points to. To be consistent with
1120 the code below, we really should preserve all non-kept slots
1121 if we can't find a match, but that seems to be much too costly. */
1122 if (GET_CODE (x) == REG && REGNO_POINTER_FLAG (REGNO (x)))
1123 p = find_temp_slot_from_address (x);
1125 /* If X is not in memory or is at a constant address, it cannot be in
1126 a temporary slot, but it can contain something whose address was
1128 if (p == 0 && (GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0))))
1130 for (p = temp_slots; p; p = p->next)
1131 if (p->in_use && p->level == temp_slot_level && p->addr_taken)
1137 /* First see if we can find a match. */
1139 p = find_temp_slot_from_address (XEXP (x, 0));
1143 /* Move everything at our level whose address was taken to our new
1144 level in case we used its address. */
1145 struct temp_slot *q;
1147 if (p->level == temp_slot_level)
1149 for (q = temp_slots; q; q = q->next)
1150 if (q != p && q->addr_taken && q->level == p->level)
1159 /* Otherwise, preserve all non-kept slots at this level. */
1160 for (p = temp_slots; p; p = p->next)
1161 if (p->in_use && p->level == temp_slot_level && ! p->keep)
1165 /* X is the result of an RTL_EXPR. If it is a temporary slot associated
1166 with that RTL_EXPR, promote it into a temporary slot at the present
1167 level so it will not be freed when we free slots made in the
1171 preserve_rtl_expr_result (x)
1174 struct temp_slot *p;
1176 /* If X is not in memory or is at a constant address, it cannot be in
1177 a temporary slot. */
1178 if (x == 0 || GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0)))
1181 /* If we can find a match, move it to our level unless it is already at
1183 p = find_temp_slot_from_address (XEXP (x, 0));
1186 p->level = MIN (p->level, temp_slot_level);
1193 /* Free all temporaries used so far. This is normally called at the end
1194 of generating code for a statement. Don't free any temporaries
1195 currently in use for an RTL_EXPR that hasn't yet been emitted.
1196 We could eventually do better than this since it can be reused while
1197 generating the same RTL_EXPR, but this is complex and probably not
1203 struct temp_slot *p;
1205 for (p = temp_slots; p; p = p->next)
1206 if (p->in_use && p->level == temp_slot_level && ! p->keep
1207 && p->rtl_expr == 0)
1210 combine_temp_slots ();
1213 /* Free all temporary slots used in T, an RTL_EXPR node. */
1216 free_temps_for_rtl_expr (t)
1219 struct temp_slot *p;
1221 for (p = temp_slots; p; p = p->next)
1222 if (p->rtl_expr == t)
1224 /* If this slot is below the current TEMP_SLOT_LEVEL, then it
1225 needs to be preserved. This can happen if a temporary in
1226 the RTL_EXPR was addressed; preserve_temp_slots will move
1227 the temporary into a higher level. */
1228 if (temp_slot_level <= p->level)
1231 p->rtl_expr = NULL_TREE;
1234 combine_temp_slots ();
1237 /* Mark all temporaries ever allocated in this function as not suitable
1238 for reuse until the current level is exited. */
1241 mark_all_temps_used ()
1243 struct temp_slot *p;
1245 for (p = temp_slots; p; p = p->next)
1247 p->in_use = p->keep = 1;
1248 p->level = MIN (p->level, temp_slot_level);
1252 /* Push deeper into the nesting level for stack temporaries. */
1260 /* Likewise, but save the new level as the place to allocate variables
1265 push_temp_slots_for_block ()
1269 var_temp_slot_level = temp_slot_level;
1272 /* Likewise, but save the new level as the place to allocate temporaries
1273 for TARGET_EXPRs. */
1276 push_temp_slots_for_target ()
1280 target_temp_slot_level = temp_slot_level;
1283 /* Set and get the value of target_temp_slot_level. The only
1284 permitted use of these functions is to save and restore this value. */
1287 get_target_temp_slot_level ()
1289 return target_temp_slot_level;
1293 set_target_temp_slot_level (level)
1296 target_temp_slot_level = level;
1300 /* Pop a temporary nesting level. All slots in use in the current level
1306 struct temp_slot *p;
1308 for (p = temp_slots; p; p = p->next)
1309 if (p->in_use && p->level == temp_slot_level && p->rtl_expr == 0)
1312 combine_temp_slots ();
1317 /* Initialize temporary slots. */
1322 /* We have not allocated any temporaries yet. */
1324 temp_slot_level = 0;
1325 var_temp_slot_level = 0;
1326 target_temp_slot_level = 0;
1329 /* Retroactively move an auto variable from a register to a stack slot.
1330 This is done when an address-reference to the variable is seen. */
1333 put_var_into_stack (decl)
1337 enum machine_mode promoted_mode, decl_mode;
1338 struct function *function = 0;
1340 int can_use_addressof;
1341 int volatilep = TREE_CODE (decl) != SAVE_EXPR && TREE_THIS_VOLATILE (decl);
1342 int usedp = (TREE_USED (decl)
1343 || (TREE_CODE (decl) != SAVE_EXPR && DECL_INITIAL (decl) != 0));
1345 context = decl_function_context (decl);
1347 /* Get the current rtl used for this object and its original mode. */
1348 reg = TREE_CODE (decl) == SAVE_EXPR ? SAVE_EXPR_RTL (decl) : DECL_RTL (decl);
1350 /* No need to do anything if decl has no rtx yet
1351 since in that case caller is setting TREE_ADDRESSABLE
1352 and a stack slot will be assigned when the rtl is made. */
1356 /* Get the declared mode for this object. */
1357 decl_mode = (TREE_CODE (decl) == SAVE_EXPR ? TYPE_MODE (TREE_TYPE (decl))
1358 : DECL_MODE (decl));
1359 /* Get the mode it's actually stored in. */
1360 promoted_mode = GET_MODE (reg);
1362 /* If this variable comes from an outer function,
1363 find that function's saved context. */
1364 if (context != current_function_decl && context != inline_function_decl)
1365 for (function = outer_function_chain; function; function = function->next)
1366 if (function->decl == context)
1369 /* If this is a variable-size object with a pseudo to address it,
1370 put that pseudo into the stack, if the var is nonlocal. */
1371 if (TREE_CODE (decl) != SAVE_EXPR && DECL_NONLOCAL (decl)
1372 && GET_CODE (reg) == MEM
1373 && GET_CODE (XEXP (reg, 0)) == REG
1374 && REGNO (XEXP (reg, 0)) > LAST_VIRTUAL_REGISTER)
1376 reg = XEXP (reg, 0);
1377 decl_mode = promoted_mode = GET_MODE (reg);
1383 /* FIXME make it work for promoted modes too */
1384 && decl_mode == promoted_mode
1385 #ifdef NON_SAVING_SETJMP
1386 && ! (NON_SAVING_SETJMP && current_function_calls_setjmp)
1390 /* If we can't use ADDRESSOF, make sure we see through one we already
1392 if (! can_use_addressof && GET_CODE (reg) == MEM
1393 && GET_CODE (XEXP (reg, 0)) == ADDRESSOF)
1394 reg = XEXP (XEXP (reg, 0), 0);
1396 /* Now we should have a value that resides in one or more pseudo regs. */
1398 if (GET_CODE (reg) == REG)
1400 /* If this variable lives in the current function and we don't need
1401 to put things in the stack for the sake of setjmp, try to keep it
1402 in a register until we know we actually need the address. */
1403 if (can_use_addressof)
1404 gen_mem_addressof (reg, decl);
1406 put_reg_into_stack (function, reg, TREE_TYPE (decl), promoted_mode,
1407 decl_mode, volatilep, 0, usedp, 0);
1409 else if (GET_CODE (reg) == CONCAT)
1411 /* A CONCAT contains two pseudos; put them both in the stack.
1412 We do it so they end up consecutive.
1413 We fixup references to the parts only after we fixup references
1414 to the whole CONCAT, lest we do double fixups for the latter
1416 enum machine_mode part_mode = GET_MODE (XEXP (reg, 0));
1417 tree part_type = type_for_mode (part_mode, 0);
1418 rtx lopart = XEXP (reg, 0);
1419 rtx hipart = XEXP (reg, 1);
1420 #ifdef FRAME_GROWS_DOWNWARD
1421 /* Since part 0 should have a lower address, do it second. */
1422 put_reg_into_stack (function, hipart, part_type, part_mode,
1423 part_mode, volatilep, 0, 0, 0);
1424 put_reg_into_stack (function, lopart, part_type, part_mode,
1425 part_mode, volatilep, 0, 0, 0);
1427 put_reg_into_stack (function, lopart, part_type, part_mode,
1428 part_mode, volatilep, 0, 0, 0);
1429 put_reg_into_stack (function, hipart, part_type, part_mode,
1430 part_mode, volatilep, 0, 0, 0);
1433 /* Change the CONCAT into a combined MEM for both parts. */
1434 PUT_CODE (reg, MEM);
1435 set_mem_attributes (reg, decl, 1);
1437 /* The two parts are in memory order already.
1438 Use the lower parts address as ours. */
1439 XEXP (reg, 0) = XEXP (XEXP (reg, 0), 0);
1440 /* Prevent sharing of rtl that might lose. */
1441 if (GET_CODE (XEXP (reg, 0)) == PLUS)
1442 XEXP (reg, 0) = copy_rtx (XEXP (reg, 0));
1445 schedule_fixup_var_refs (function, reg, TREE_TYPE (decl),
1447 schedule_fixup_var_refs (function, lopart, part_type, part_mode, 0);
1448 schedule_fixup_var_refs (function, hipart, part_type, part_mode, 0);
1454 if (current_function_check_memory_usage)
1455 emit_library_call (chkr_set_right_libfunc, 1, VOIDmode, 3,
1456 XEXP (reg, 0), Pmode,
1457 GEN_INT (GET_MODE_SIZE (GET_MODE (reg))),
1458 TYPE_MODE (sizetype),
1459 GEN_INT (MEMORY_USE_RW),
1460 TYPE_MODE (integer_type_node));
1463 /* Subroutine of put_var_into_stack. This puts a single pseudo reg REG
1464 into the stack frame of FUNCTION (0 means the current function).
1465 DECL_MODE is the machine mode of the user-level data type.
1466 PROMOTED_MODE is the machine mode of the register.
1467 VOLATILE_P is nonzero if this is for a "volatile" decl.
1468 USED_P is nonzero if this reg might have already been used in an insn. */
1471 put_reg_into_stack (function, reg, type, promoted_mode, decl_mode, volatile_p,
1472 original_regno, used_p, ht)
1473 struct function *function;
1476 enum machine_mode promoted_mode, decl_mode;
1478 unsigned int original_regno;
1480 struct hash_table *ht;
1482 struct function *func = function ? function : cfun;
1484 unsigned int regno = original_regno;
1487 regno = REGNO (reg);
1489 if (regno < func->x_max_parm_reg)
1490 new = func->x_parm_reg_stack_loc[regno];
1493 new = assign_stack_local_1 (decl_mode, GET_MODE_SIZE (decl_mode), 0, func);
1495 PUT_CODE (reg, MEM);
1496 PUT_MODE (reg, decl_mode);
1497 XEXP (reg, 0) = XEXP (new, 0);
1498 /* `volatil' bit means one thing for MEMs, another entirely for REGs. */
1499 MEM_VOLATILE_P (reg) = volatile_p;
1501 /* If this is a memory ref that contains aggregate components,
1502 mark it as such for cse and loop optimize. If we are reusing a
1503 previously generated stack slot, then we need to copy the bit in
1504 case it was set for other reasons. For instance, it is set for
1505 __builtin_va_alist. */
1508 MEM_SET_IN_STRUCT_P (reg,
1509 AGGREGATE_TYPE_P (type) || MEM_IN_STRUCT_P (new));
1510 MEM_ALIAS_SET (reg) = get_alias_set (type);
1513 schedule_fixup_var_refs (function, reg, type, promoted_mode, ht);
1516 /* Make sure that all refs to the variable, previously made
1517 when it was a register, are fixed up to be valid again.
1518 See function above for meaning of arguments. */
1520 schedule_fixup_var_refs (function, reg, type, promoted_mode, ht)
1521 struct function *function;
1524 enum machine_mode promoted_mode;
1525 struct hash_table *ht;
1527 int unsigned_p = type ? TREE_UNSIGNED (type) : 0;
1531 struct var_refs_queue *temp;
1534 = (struct var_refs_queue *) xmalloc (sizeof (struct var_refs_queue));
1535 temp->modified = reg;
1536 temp->promoted_mode = promoted_mode;
1537 temp->unsignedp = unsigned_p;
1538 temp->next = function->fixup_var_refs_queue;
1539 function->fixup_var_refs_queue = temp;
1542 /* Variable is local; fix it up now. */
1543 fixup_var_refs (reg, promoted_mode, unsigned_p, ht);
1547 fixup_var_refs (var, promoted_mode, unsignedp, ht)
1549 enum machine_mode promoted_mode;
1551 struct hash_table *ht;
1554 rtx first_insn = get_insns ();
1555 struct sequence_stack *stack = seq_stack;
1556 tree rtl_exps = rtl_expr_chain;
1559 /* Must scan all insns for stack-refs that exceed the limit. */
1560 fixup_var_refs_insns (var, promoted_mode, unsignedp, first_insn,
1562 /* If there's a hash table, it must record all uses of VAR. */
1566 /* Scan all pending sequences too. */
1567 for (; stack; stack = stack->next)
1569 push_to_sequence (stack->first);
1570 fixup_var_refs_insns (var, promoted_mode, unsignedp,
1571 stack->first, stack->next != 0, 0);
1572 /* Update remembered end of sequence
1573 in case we added an insn at the end. */
1574 stack->last = get_last_insn ();
1578 /* Scan all waiting RTL_EXPRs too. */
1579 for (pending = rtl_exps; pending; pending = TREE_CHAIN (pending))
1581 rtx seq = RTL_EXPR_SEQUENCE (TREE_VALUE (pending));
1582 if (seq != const0_rtx && seq != 0)
1584 push_to_sequence (seq);
1585 fixup_var_refs_insns (var, promoted_mode, unsignedp, seq, 0, 0);
1590 /* Scan the catch clauses for exception handling too. */
1591 push_to_full_sequence (catch_clauses, catch_clauses_last);
1592 fixup_var_refs_insns (var, promoted_mode, unsignedp, catch_clauses, 0, 0);
1593 end_full_sequence (&catch_clauses, &catch_clauses_last);
1595 /* Scan sequences saved in CALL_PLACEHOLDERS too. */
1596 for (insn = first_insn; insn; insn = NEXT_INSN (insn))
1598 if (GET_CODE (insn) == CALL_INSN
1599 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
1603 /* Look at the Normal call, sibling call and tail recursion
1604 sequences attached to the CALL_PLACEHOLDER. */
1605 for (i = 0; i < 3; i++)
1607 rtx seq = XEXP (PATTERN (insn), i);
1610 push_to_sequence (seq);
1611 fixup_var_refs_insns (var, promoted_mode, unsignedp,
1613 XEXP (PATTERN (insn), i) = get_insns ();
1621 /* REPLACEMENTS is a pointer to a list of the struct fixup_replacement and X is
1622 some part of an insn. Return a struct fixup_replacement whose OLD
1623 value is equal to X. Allocate a new structure if no such entry exists. */
1625 static struct fixup_replacement *
1626 find_fixup_replacement (replacements, x)
1627 struct fixup_replacement **replacements;
1630 struct fixup_replacement *p;
1632 /* See if we have already replaced this. */
1633 for (p = *replacements; p != 0 && ! rtx_equal_p (p->old, x); p = p->next)
1638 p = (struct fixup_replacement *) oballoc (sizeof (struct fixup_replacement));
1641 p->next = *replacements;
1648 /* Scan the insn-chain starting with INSN for refs to VAR
1649 and fix them up. TOPLEVEL is nonzero if this chain is the
1650 main chain of insns for the current function. */
1653 fixup_var_refs_insns (var, promoted_mode, unsignedp, insn, toplevel, ht)
1655 enum machine_mode promoted_mode;
1659 struct hash_table *ht;
1662 rtx insn_list = NULL_RTX;
1664 /* If we already know which INSNs reference VAR there's no need
1665 to walk the entire instruction chain. */
1668 insn_list = ((struct insns_for_mem_entry *)
1669 hash_lookup (ht, var, /*create=*/0, /*copy=*/0))->insns;
1670 insn = insn_list ? XEXP (insn_list, 0) : NULL_RTX;
1671 insn_list = XEXP (insn_list, 1);
1676 rtx next = NEXT_INSN (insn);
1677 rtx set, prev, prev_set;
1682 /* Remember the notes in case we delete the insn. */
1683 note = REG_NOTES (insn);
1685 /* If this is a CLOBBER of VAR, delete it.
1687 If it has a REG_LIBCALL note, delete the REG_LIBCALL
1688 and REG_RETVAL notes too. */
1689 if (GET_CODE (PATTERN (insn)) == CLOBBER
1690 && (XEXP (PATTERN (insn), 0) == var
1691 || (GET_CODE (XEXP (PATTERN (insn), 0)) == CONCAT
1692 && (XEXP (XEXP (PATTERN (insn), 0), 0) == var
1693 || XEXP (XEXP (PATTERN (insn), 0), 1) == var))))
1695 if ((note = find_reg_note (insn, REG_LIBCALL, NULL_RTX)) != 0)
1696 /* The REG_LIBCALL note will go away since we are going to
1697 turn INSN into a NOTE, so just delete the
1698 corresponding REG_RETVAL note. */
1699 remove_note (XEXP (note, 0),
1700 find_reg_note (XEXP (note, 0), REG_RETVAL,
1703 /* In unoptimized compilation, we shouldn't call delete_insn
1704 except in jump.c doing warnings. */
1705 PUT_CODE (insn, NOTE);
1706 NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
1707 NOTE_SOURCE_FILE (insn) = 0;
1710 /* The insn to load VAR from a home in the arglist
1711 is now a no-op. When we see it, just delete it.
1712 Similarly if this is storing VAR from a register from which
1713 it was loaded in the previous insn. This will occur
1714 when an ADDRESSOF was made for an arglist slot. */
1716 && (set = single_set (insn)) != 0
1717 && SET_DEST (set) == var
1718 /* If this represents the result of an insn group,
1719 don't delete the insn. */
1720 && find_reg_note (insn, REG_RETVAL, NULL_RTX) == 0
1721 && (rtx_equal_p (SET_SRC (set), var)
1722 || (GET_CODE (SET_SRC (set)) == REG
1723 && (prev = prev_nonnote_insn (insn)) != 0
1724 && (prev_set = single_set (prev)) != 0
1725 && SET_DEST (prev_set) == SET_SRC (set)
1726 && rtx_equal_p (SET_SRC (prev_set), var))))
1728 /* In unoptimized compilation, we shouldn't call delete_insn
1729 except in jump.c doing warnings. */
1730 PUT_CODE (insn, NOTE);
1731 NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
1732 NOTE_SOURCE_FILE (insn) = 0;
1733 if (insn == last_parm_insn)
1734 last_parm_insn = PREV_INSN (next);
1738 struct fixup_replacement *replacements = 0;
1739 rtx next_insn = NEXT_INSN (insn);
1741 if (SMALL_REGISTER_CLASSES)
1743 /* If the insn that copies the results of a CALL_INSN
1744 into a pseudo now references VAR, we have to use an
1745 intermediate pseudo since we want the life of the
1746 return value register to be only a single insn.
1748 If we don't use an intermediate pseudo, such things as
1749 address computations to make the address of VAR valid
1750 if it is not can be placed between the CALL_INSN and INSN.
1752 To make sure this doesn't happen, we record the destination
1753 of the CALL_INSN and see if the next insn uses both that
1756 if (call_dest != 0 && GET_CODE (insn) == INSN
1757 && reg_mentioned_p (var, PATTERN (insn))
1758 && reg_mentioned_p (call_dest, PATTERN (insn)))
1760 rtx temp = gen_reg_rtx (GET_MODE (call_dest));
1762 emit_insn_before (gen_move_insn (temp, call_dest), insn);
1764 PATTERN (insn) = replace_rtx (PATTERN (insn),
1768 if (GET_CODE (insn) == CALL_INSN
1769 && GET_CODE (PATTERN (insn)) == SET)
1770 call_dest = SET_DEST (PATTERN (insn));
1771 else if (GET_CODE (insn) == CALL_INSN
1772 && GET_CODE (PATTERN (insn)) == PARALLEL
1773 && GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == SET)
1774 call_dest = SET_DEST (XVECEXP (PATTERN (insn), 0, 0));
1779 /* See if we have to do anything to INSN now that VAR is in
1780 memory. If it needs to be loaded into a pseudo, use a single
1781 pseudo for the entire insn in case there is a MATCH_DUP
1782 between two operands. We pass a pointer to the head of
1783 a list of struct fixup_replacements. If fixup_var_refs_1
1784 needs to allocate pseudos or replacement MEMs (for SUBREGs),
1785 it will record them in this list.
1787 If it allocated a pseudo for any replacement, we copy into
1790 fixup_var_refs_1 (var, promoted_mode, &PATTERN (insn), insn,
1793 /* If this is last_parm_insn, and any instructions were output
1794 after it to fix it up, then we must set last_parm_insn to
1795 the last such instruction emitted. */
1796 if (insn == last_parm_insn)
1797 last_parm_insn = PREV_INSN (next_insn);
1799 while (replacements)
1801 if (GET_CODE (replacements->new) == REG)
1806 /* OLD might be a (subreg (mem)). */
1807 if (GET_CODE (replacements->old) == SUBREG)
1809 = fixup_memory_subreg (replacements->old, insn, 0);
1812 = fixup_stack_1 (replacements->old, insn);
1814 insert_before = insn;
1816 /* If we are changing the mode, do a conversion.
1817 This might be wasteful, but combine.c will
1818 eliminate much of the waste. */
1820 if (GET_MODE (replacements->new)
1821 != GET_MODE (replacements->old))
1824 convert_move (replacements->new,
1825 replacements->old, unsignedp);
1826 seq = gen_sequence ();
1830 seq = gen_move_insn (replacements->new,
1833 emit_insn_before (seq, insert_before);
1836 replacements = replacements->next;
1840 /* Also fix up any invalid exprs in the REG_NOTES of this insn.
1841 But don't touch other insns referred to by reg-notes;
1842 we will get them elsewhere. */
1845 if (GET_CODE (note) != INSN_LIST)
1847 = walk_fixup_memory_subreg (XEXP (note, 0), insn, 1);
1848 note = XEXP (note, 1);
1856 insn = XEXP (insn_list, 0);
1857 insn_list = XEXP (insn_list, 1);
1864 /* VAR is a MEM that used to be a pseudo register with mode PROMOTED_MODE.
1865 See if the rtx expression at *LOC in INSN needs to be changed.
1867 REPLACEMENTS is a pointer to a list head that starts out zero, but may
1868 contain a list of original rtx's and replacements. If we find that we need
1869 to modify this insn by replacing a memory reference with a pseudo or by
1870 making a new MEM to implement a SUBREG, we consult that list to see if
1871 we have already chosen a replacement. If none has already been allocated,
1872 we allocate it and update the list. fixup_var_refs_insns will copy VAR
1873 or the SUBREG, as appropriate, to the pseudo. */
1876 fixup_var_refs_1 (var, promoted_mode, loc, insn, replacements)
1878 enum machine_mode promoted_mode;
1881 struct fixup_replacement **replacements;
1884 register rtx x = *loc;
1885 RTX_CODE code = GET_CODE (x);
1886 register const char *fmt;
1887 register rtx tem, tem1;
1888 struct fixup_replacement *replacement;
1893 if (XEXP (x, 0) == var)
1895 /* Prevent sharing of rtl that might lose. */
1896 rtx sub = copy_rtx (XEXP (var, 0));
1898 if (! validate_change (insn, loc, sub, 0))
1900 rtx y = gen_reg_rtx (GET_MODE (sub));
1903 /* We should be able to replace with a register or all is lost.
1904 Note that we can't use validate_change to verify this, since
1905 we're not caring for replacing all dups simultaneously. */
1906 if (! validate_replace_rtx (*loc, y, insn))
1909 /* Careful! First try to recognize a direct move of the
1910 value, mimicking how things are done in gen_reload wrt
1911 PLUS. Consider what happens when insn is a conditional
1912 move instruction and addsi3 clobbers flags. */
1915 new_insn = emit_insn (gen_rtx_SET (VOIDmode, y, sub));
1916 seq = gen_sequence ();
1919 if (recog_memoized (new_insn) < 0)
1921 /* That failed. Fall back on force_operand and hope. */
1924 force_operand (sub, y);
1925 seq = gen_sequence ();
1930 /* Don't separate setter from user. */
1931 if (PREV_INSN (insn) && sets_cc0_p (PREV_INSN (insn)))
1932 insn = PREV_INSN (insn);
1935 emit_insn_before (seq, insn);
1943 /* If we already have a replacement, use it. Otherwise,
1944 try to fix up this address in case it is invalid. */
1946 replacement = find_fixup_replacement (replacements, var);
1947 if (replacement->new)
1949 *loc = replacement->new;
1953 *loc = replacement->new = x = fixup_stack_1 (x, insn);
1955 /* Unless we are forcing memory to register or we changed the mode,
1956 we can leave things the way they are if the insn is valid. */
1958 INSN_CODE (insn) = -1;
1959 if (! flag_force_mem && GET_MODE (x) == promoted_mode
1960 && recog_memoized (insn) >= 0)
1963 *loc = replacement->new = gen_reg_rtx (promoted_mode);
1967 /* If X contains VAR, we need to unshare it here so that we update
1968 each occurrence separately. But all identical MEMs in one insn
1969 must be replaced with the same rtx because of the possibility of
1972 if (reg_mentioned_p (var, x))
1974 replacement = find_fixup_replacement (replacements, x);
1975 if (replacement->new == 0)
1976 replacement->new = copy_most_rtx (x, var);
1978 *loc = x = replacement->new;
1994 /* Note that in some cases those types of expressions are altered
1995 by optimize_bit_field, and do not survive to get here. */
1996 if (XEXP (x, 0) == var
1997 || (GET_CODE (XEXP (x, 0)) == SUBREG
1998 && SUBREG_REG (XEXP (x, 0)) == var))
2000 /* Get TEM as a valid MEM in the mode presently in the insn.
2002 We don't worry about the possibility of MATCH_DUP here; it
2003 is highly unlikely and would be tricky to handle. */
2006 if (GET_CODE (tem) == SUBREG)
2008 if (GET_MODE_BITSIZE (GET_MODE (tem))
2009 > GET_MODE_BITSIZE (GET_MODE (var)))
2011 replacement = find_fixup_replacement (replacements, var);
2012 if (replacement->new == 0)
2013 replacement->new = gen_reg_rtx (GET_MODE (var));
2014 SUBREG_REG (tem) = replacement->new;
2017 tem = fixup_memory_subreg (tem, insn, 0);
2020 tem = fixup_stack_1 (tem, insn);
2022 /* Unless we want to load from memory, get TEM into the proper mode
2023 for an extract from memory. This can only be done if the
2024 extract is at a constant position and length. */
2026 if (! flag_force_mem && GET_CODE (XEXP (x, 1)) == CONST_INT
2027 && GET_CODE (XEXP (x, 2)) == CONST_INT
2028 && ! mode_dependent_address_p (XEXP (tem, 0))
2029 && ! MEM_VOLATILE_P (tem))
2031 enum machine_mode wanted_mode = VOIDmode;
2032 enum machine_mode is_mode = GET_MODE (tem);
2033 HOST_WIDE_INT pos = INTVAL (XEXP (x, 2));
2036 if (GET_CODE (x) == ZERO_EXTRACT)
2039 = insn_data[(int) CODE_FOR_extzv].operand[1].mode;
2040 if (wanted_mode == VOIDmode)
2041 wanted_mode = word_mode;
2045 if (GET_CODE (x) == SIGN_EXTRACT)
2047 wanted_mode = insn_data[(int) CODE_FOR_extv].operand[1].mode;
2048 if (wanted_mode == VOIDmode)
2049 wanted_mode = word_mode;
2052 /* If we have a narrower mode, we can do something. */
2053 if (wanted_mode != VOIDmode
2054 && GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
2056 HOST_WIDE_INT offset = pos / BITS_PER_UNIT;
2057 rtx old_pos = XEXP (x, 2);
2060 /* If the bytes and bits are counted differently, we
2061 must adjust the offset. */
2062 if (BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN)
2063 offset = (GET_MODE_SIZE (is_mode)
2064 - GET_MODE_SIZE (wanted_mode) - offset);
2066 pos %= GET_MODE_BITSIZE (wanted_mode);
2068 newmem = gen_rtx_MEM (wanted_mode,
2069 plus_constant (XEXP (tem, 0), offset));
2070 MEM_COPY_ATTRIBUTES (newmem, tem);
2072 /* Make the change and see if the insn remains valid. */
2073 INSN_CODE (insn) = -1;
2074 XEXP (x, 0) = newmem;
2075 XEXP (x, 2) = GEN_INT (pos);
2077 if (recog_memoized (insn) >= 0)
2080 /* Otherwise, restore old position. XEXP (x, 0) will be
2082 XEXP (x, 2) = old_pos;
2086 /* If we get here, the bitfield extract insn can't accept a memory
2087 reference. Copy the input into a register. */
2089 tem1 = gen_reg_rtx (GET_MODE (tem));
2090 emit_insn_before (gen_move_insn (tem1, tem), insn);
2097 if (SUBREG_REG (x) == var)
2099 /* If this is a special SUBREG made because VAR was promoted
2100 from a wider mode, replace it with VAR and call ourself
2101 recursively, this time saying that the object previously
2102 had its current mode (by virtue of the SUBREG). */
2104 if (SUBREG_PROMOTED_VAR_P (x))
2107 fixup_var_refs_1 (var, GET_MODE (var), loc, insn, replacements);
2111 /* If this SUBREG makes VAR wider, it has become a paradoxical
2112 SUBREG with VAR in memory, but these aren't allowed at this
2113 stage of the compilation. So load VAR into a pseudo and take
2114 a SUBREG of that pseudo. */
2115 if (GET_MODE_SIZE (GET_MODE (x)) > GET_MODE_SIZE (GET_MODE (var)))
2117 replacement = find_fixup_replacement (replacements, var);
2118 if (replacement->new == 0)
2119 replacement->new = gen_reg_rtx (GET_MODE (var));
2120 SUBREG_REG (x) = replacement->new;
2124 /* See if we have already found a replacement for this SUBREG.
2125 If so, use it. Otherwise, make a MEM and see if the insn
2126 is recognized. If not, or if we should force MEM into a register,
2127 make a pseudo for this SUBREG. */
2128 replacement = find_fixup_replacement (replacements, x);
2129 if (replacement->new)
2131 *loc = replacement->new;
2135 replacement->new = *loc = fixup_memory_subreg (x, insn, 0);
2137 INSN_CODE (insn) = -1;
2138 if (! flag_force_mem && recog_memoized (insn) >= 0)
2141 *loc = replacement->new = gen_reg_rtx (GET_MODE (x));
2147 /* First do special simplification of bit-field references. */
2148 if (GET_CODE (SET_DEST (x)) == SIGN_EXTRACT
2149 || GET_CODE (SET_DEST (x)) == ZERO_EXTRACT)
2150 optimize_bit_field (x, insn, 0);
2151 if (GET_CODE (SET_SRC (x)) == SIGN_EXTRACT
2152 || GET_CODE (SET_SRC (x)) == ZERO_EXTRACT)
2153 optimize_bit_field (x, insn, NULL_PTR);
2155 /* For a paradoxical SUBREG inside a ZERO_EXTRACT, load the object
2156 into a register and then store it back out. */
2157 if (GET_CODE (SET_DEST (x)) == ZERO_EXTRACT
2158 && GET_CODE (XEXP (SET_DEST (x), 0)) == SUBREG
2159 && SUBREG_REG (XEXP (SET_DEST (x), 0)) == var
2160 && (GET_MODE_SIZE (GET_MODE (XEXP (SET_DEST (x), 0)))
2161 > GET_MODE_SIZE (GET_MODE (var))))
2163 replacement = find_fixup_replacement (replacements, var);
2164 if (replacement->new == 0)
2165 replacement->new = gen_reg_rtx (GET_MODE (var));
2167 SUBREG_REG (XEXP (SET_DEST (x), 0)) = replacement->new;
2168 emit_insn_after (gen_move_insn (var, replacement->new), insn);
2171 /* If SET_DEST is now a paradoxical SUBREG, put the result of this
2172 insn into a pseudo and store the low part of the pseudo into VAR. */
2173 if (GET_CODE (SET_DEST (x)) == SUBREG
2174 && SUBREG_REG (SET_DEST (x)) == var
2175 && (GET_MODE_SIZE (GET_MODE (SET_DEST (x)))
2176 > GET_MODE_SIZE (GET_MODE (var))))
2178 SET_DEST (x) = tem = gen_reg_rtx (GET_MODE (SET_DEST (x)));
2179 emit_insn_after (gen_move_insn (var, gen_lowpart (GET_MODE (var),
2186 rtx dest = SET_DEST (x);
2187 rtx src = SET_SRC (x);
2189 rtx outerdest = dest;
2192 while (GET_CODE (dest) == SUBREG || GET_CODE (dest) == STRICT_LOW_PART
2193 || GET_CODE (dest) == SIGN_EXTRACT
2194 || GET_CODE (dest) == ZERO_EXTRACT)
2195 dest = XEXP (dest, 0);
2197 if (GET_CODE (src) == SUBREG)
2198 src = XEXP (src, 0);
2200 /* If VAR does not appear at the top level of the SET
2201 just scan the lower levels of the tree. */
2203 if (src != var && dest != var)
2206 /* We will need to rerecognize this insn. */
2207 INSN_CODE (insn) = -1;
2210 if (GET_CODE (outerdest) == ZERO_EXTRACT && dest == var)
2212 /* Since this case will return, ensure we fixup all the
2214 fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 1),
2215 insn, replacements);
2216 fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 2),
2217 insn, replacements);
2218 fixup_var_refs_1 (var, promoted_mode, &SET_SRC (x),
2219 insn, replacements);
2221 tem = XEXP (outerdest, 0);
2223 /* Clean up (SUBREG:SI (MEM:mode ...) 0)
2224 that may appear inside a ZERO_EXTRACT.
2225 This was legitimate when the MEM was a REG. */
2226 if (GET_CODE (tem) == SUBREG
2227 && SUBREG_REG (tem) == var)
2228 tem = fixup_memory_subreg (tem, insn, 0);
2230 tem = fixup_stack_1 (tem, insn);
2232 if (GET_CODE (XEXP (outerdest, 1)) == CONST_INT
2233 && GET_CODE (XEXP (outerdest, 2)) == CONST_INT
2234 && ! mode_dependent_address_p (XEXP (tem, 0))
2235 && ! MEM_VOLATILE_P (tem))
2237 enum machine_mode wanted_mode;
2238 enum machine_mode is_mode = GET_MODE (tem);
2239 HOST_WIDE_INT pos = INTVAL (XEXP (outerdest, 2));
2241 wanted_mode = insn_data[(int) CODE_FOR_insv].operand[0].mode;
2242 if (wanted_mode == VOIDmode)
2243 wanted_mode = word_mode;
2245 /* If we have a narrower mode, we can do something. */
2246 if (GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
2248 HOST_WIDE_INT offset = pos / BITS_PER_UNIT;
2249 rtx old_pos = XEXP (outerdest, 2);
2252 if (BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN)
2253 offset = (GET_MODE_SIZE (is_mode)
2254 - GET_MODE_SIZE (wanted_mode) - offset);
2256 pos %= GET_MODE_BITSIZE (wanted_mode);
2258 newmem = gen_rtx_MEM (wanted_mode,
2259 plus_constant (XEXP (tem, 0),
2261 MEM_COPY_ATTRIBUTES (newmem, tem);
2263 /* Make the change and see if the insn remains valid. */
2264 INSN_CODE (insn) = -1;
2265 XEXP (outerdest, 0) = newmem;
2266 XEXP (outerdest, 2) = GEN_INT (pos);
2268 if (recog_memoized (insn) >= 0)
2271 /* Otherwise, restore old position. XEXP (x, 0) will be
2273 XEXP (outerdest, 2) = old_pos;
2277 /* If we get here, the bit-field store doesn't allow memory
2278 or isn't located at a constant position. Load the value into
2279 a register, do the store, and put it back into memory. */
2281 tem1 = gen_reg_rtx (GET_MODE (tem));
2282 emit_insn_before (gen_move_insn (tem1, tem), insn);
2283 emit_insn_after (gen_move_insn (tem, tem1), insn);
2284 XEXP (outerdest, 0) = tem1;
2289 /* STRICT_LOW_PART is a no-op on memory references
2290 and it can cause combinations to be unrecognizable,
2293 if (dest == var && GET_CODE (SET_DEST (x)) == STRICT_LOW_PART)
2294 SET_DEST (x) = XEXP (SET_DEST (x), 0);
2296 /* A valid insn to copy VAR into or out of a register
2297 must be left alone, to avoid an infinite loop here.
2298 If the reference to VAR is by a subreg, fix that up,
2299 since SUBREG is not valid for a memref.
2300 Also fix up the address of the stack slot.
2302 Note that we must not try to recognize the insn until
2303 after we know that we have valid addresses and no
2304 (subreg (mem ...) ...) constructs, since these interfere
2305 with determining the validity of the insn. */
2307 if ((SET_SRC (x) == var
2308 || (GET_CODE (SET_SRC (x)) == SUBREG
2309 && SUBREG_REG (SET_SRC (x)) == var))
2310 && (GET_CODE (SET_DEST (x)) == REG
2311 || (GET_CODE (SET_DEST (x)) == SUBREG
2312 && GET_CODE (SUBREG_REG (SET_DEST (x))) == REG))
2313 && GET_MODE (var) == promoted_mode
2314 && x == single_set (insn))
2318 replacement = find_fixup_replacement (replacements, SET_SRC (x));
2319 if (replacement->new)
2320 SET_SRC (x) = replacement->new;
2321 else if (GET_CODE (SET_SRC (x)) == SUBREG)
2322 SET_SRC (x) = replacement->new
2323 = fixup_memory_subreg (SET_SRC (x), insn, 0);
2325 SET_SRC (x) = replacement->new
2326 = fixup_stack_1 (SET_SRC (x), insn);
2328 if (recog_memoized (insn) >= 0)
2331 /* INSN is not valid, but we know that we want to
2332 copy SET_SRC (x) to SET_DEST (x) in some way. So
2333 we generate the move and see whether it requires more
2334 than one insn. If it does, we emit those insns and
2335 delete INSN. Otherwise, we an just replace the pattern
2336 of INSN; we have already verified above that INSN has
2337 no other function that to do X. */
2339 pat = gen_move_insn (SET_DEST (x), SET_SRC (x));
2340 if (GET_CODE (pat) == SEQUENCE)
2342 emit_insn_after (pat, insn);
2343 PUT_CODE (insn, NOTE);
2344 NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
2345 NOTE_SOURCE_FILE (insn) = 0;
2348 PATTERN (insn) = pat;
2353 if ((SET_DEST (x) == var
2354 || (GET_CODE (SET_DEST (x)) == SUBREG
2355 && SUBREG_REG (SET_DEST (x)) == var))
2356 && (GET_CODE (SET_SRC (x)) == REG
2357 || (GET_CODE (SET_SRC (x)) == SUBREG
2358 && GET_CODE (SUBREG_REG (SET_SRC (x))) == REG))
2359 && GET_MODE (var) == promoted_mode
2360 && x == single_set (insn))
2364 if (GET_CODE (SET_DEST (x)) == SUBREG)
2365 SET_DEST (x) = fixup_memory_subreg (SET_DEST (x), insn, 0);
2367 SET_DEST (x) = fixup_stack_1 (SET_DEST (x), insn);
2369 if (recog_memoized (insn) >= 0)
2372 pat = gen_move_insn (SET_DEST (x), SET_SRC (x));
2373 if (GET_CODE (pat) == SEQUENCE)
2375 emit_insn_after (pat, insn);
2376 PUT_CODE (insn, NOTE);
2377 NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
2378 NOTE_SOURCE_FILE (insn) = 0;
2381 PATTERN (insn) = pat;
2386 /* Otherwise, storing into VAR must be handled specially
2387 by storing into a temporary and copying that into VAR
2388 with a new insn after this one. Note that this case
2389 will be used when storing into a promoted scalar since
2390 the insn will now have different modes on the input
2391 and output and hence will be invalid (except for the case
2392 of setting it to a constant, which does not need any
2393 change if it is valid). We generate extra code in that case,
2394 but combine.c will eliminate it. */
2399 rtx fixeddest = SET_DEST (x);
2401 /* STRICT_LOW_PART can be discarded, around a MEM. */
2402 if (GET_CODE (fixeddest) == STRICT_LOW_PART)
2403 fixeddest = XEXP (fixeddest, 0);
2404 /* Convert (SUBREG (MEM)) to a MEM in a changed mode. */
2405 if (GET_CODE (fixeddest) == SUBREG)
2407 fixeddest = fixup_memory_subreg (fixeddest, insn, 0);
2408 promoted_mode = GET_MODE (fixeddest);
2411 fixeddest = fixup_stack_1 (fixeddest, insn);
2413 temp = gen_reg_rtx (promoted_mode);
2415 emit_insn_after (gen_move_insn (fixeddest,
2416 gen_lowpart (GET_MODE (fixeddest),
2420 SET_DEST (x) = temp;
2428 /* Nothing special about this RTX; fix its operands. */
2430 fmt = GET_RTX_FORMAT (code);
2431 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2434 fixup_var_refs_1 (var, promoted_mode, &XEXP (x, i), insn, replacements);
2435 else if (fmt[i] == 'E')
2438 for (j = 0; j < XVECLEN (x, i); j++)
2439 fixup_var_refs_1 (var, promoted_mode, &XVECEXP (x, i, j),
2440 insn, replacements);
2445 /* Given X, an rtx of the form (SUBREG:m1 (MEM:m2 addr)),
2446 return an rtx (MEM:m1 newaddr) which is equivalent.
2447 If any insns must be emitted to compute NEWADDR, put them before INSN.
2449 UNCRITICAL nonzero means accept paradoxical subregs.
2450 This is used for subregs found inside REG_NOTES. */
2453 fixup_memory_subreg (x, insn, uncritical)
2458 int offset = SUBREG_WORD (x) * UNITS_PER_WORD;
2459 rtx addr = XEXP (SUBREG_REG (x), 0);
2460 enum machine_mode mode = GET_MODE (x);
2463 /* Paradoxical SUBREGs are usually invalid during RTL generation. */
2464 if (GET_MODE_SIZE (mode) > GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))
2468 if (BYTES_BIG_ENDIAN)
2469 offset += (MIN (UNITS_PER_WORD, GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
2470 - MIN (UNITS_PER_WORD, GET_MODE_SIZE (mode)));
2471 addr = plus_constant (addr, offset);
2472 if (!flag_force_addr && memory_address_p (mode, addr))
2473 /* Shortcut if no insns need be emitted. */
2474 return change_address (SUBREG_REG (x), mode, addr);
2476 result = change_address (SUBREG_REG (x), mode, addr);
2477 emit_insn_before (gen_sequence (), insn);
2482 /* Do fixup_memory_subreg on all (SUBREG (MEM ...) ...) contained in X.
2483 Replace subexpressions of X in place.
2484 If X itself is a (SUBREG (MEM ...) ...), return the replacement expression.
2485 Otherwise return X, with its contents possibly altered.
2487 If any insns must be emitted to compute NEWADDR, put them before INSN.
2489 UNCRITICAL is as in fixup_memory_subreg. */
2492 walk_fixup_memory_subreg (x, insn, uncritical)
2497 register enum rtx_code code;
2498 register const char *fmt;
2504 code = GET_CODE (x);
2506 if (code == SUBREG && GET_CODE (SUBREG_REG (x)) == MEM)
2507 return fixup_memory_subreg (x, insn, uncritical);
2509 /* Nothing special about this RTX; fix its operands. */
2511 fmt = GET_RTX_FORMAT (code);
2512 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2515 XEXP (x, i) = walk_fixup_memory_subreg (XEXP (x, i), insn, uncritical);
2516 else if (fmt[i] == 'E')
2519 for (j = 0; j < XVECLEN (x, i); j++)
2521 = walk_fixup_memory_subreg (XVECEXP (x, i, j), insn, uncritical);
2527 /* For each memory ref within X, if it refers to a stack slot
2528 with an out of range displacement, put the address in a temp register
2529 (emitting new insns before INSN to load these registers)
2530 and alter the memory ref to use that register.
2531 Replace each such MEM rtx with a copy, to avoid clobberage. */
2534 fixup_stack_1 (x, insn)
2539 register RTX_CODE code = GET_CODE (x);
2540 register const char *fmt;
2544 register rtx ad = XEXP (x, 0);
2545 /* If we have address of a stack slot but it's not valid
2546 (displacement is too large), compute the sum in a register. */
2547 if (GET_CODE (ad) == PLUS
2548 && GET_CODE (XEXP (ad, 0)) == REG
2549 && ((REGNO (XEXP (ad, 0)) >= FIRST_VIRTUAL_REGISTER
2550 && REGNO (XEXP (ad, 0)) <= LAST_VIRTUAL_REGISTER)
2551 || REGNO (XEXP (ad, 0)) == FRAME_POINTER_REGNUM
2552 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
2553 || REGNO (XEXP (ad, 0)) == HARD_FRAME_POINTER_REGNUM
2555 || REGNO (XEXP (ad, 0)) == STACK_POINTER_REGNUM
2556 || REGNO (XEXP (ad, 0)) == ARG_POINTER_REGNUM
2557 || XEXP (ad, 0) == current_function_internal_arg_pointer)
2558 && GET_CODE (XEXP (ad, 1)) == CONST_INT)
2561 if (memory_address_p (GET_MODE (x), ad))
2565 temp = copy_to_reg (ad);
2566 seq = gen_sequence ();
2568 emit_insn_before (seq, insn);
2569 return change_address (x, VOIDmode, temp);
2574 fmt = GET_RTX_FORMAT (code);
2575 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2578 XEXP (x, i) = fixup_stack_1 (XEXP (x, i), insn);
2579 else if (fmt[i] == 'E')
2582 for (j = 0; j < XVECLEN (x, i); j++)
2583 XVECEXP (x, i, j) = fixup_stack_1 (XVECEXP (x, i, j), insn);
2589 /* Optimization: a bit-field instruction whose field
2590 happens to be a byte or halfword in memory
2591 can be changed to a move instruction.
2593 We call here when INSN is an insn to examine or store into a bit-field.
2594 BODY is the SET-rtx to be altered.
2596 EQUIV_MEM is the table `reg_equiv_mem' if that is available; else 0.
2597 (Currently this is called only from function.c, and EQUIV_MEM
2601 optimize_bit_field (body, insn, equiv_mem)
2606 register rtx bitfield;
2609 enum machine_mode mode;
2611 if (GET_CODE (SET_DEST (body)) == SIGN_EXTRACT
2612 || GET_CODE (SET_DEST (body)) == ZERO_EXTRACT)
2613 bitfield = SET_DEST (body), destflag = 1;
2615 bitfield = SET_SRC (body), destflag = 0;
2617 /* First check that the field being stored has constant size and position
2618 and is in fact a byte or halfword suitably aligned. */
2620 if (GET_CODE (XEXP (bitfield, 1)) == CONST_INT
2621 && GET_CODE (XEXP (bitfield, 2)) == CONST_INT
2622 && ((mode = mode_for_size (INTVAL (XEXP (bitfield, 1)), MODE_INT, 1))
2624 && INTVAL (XEXP (bitfield, 2)) % INTVAL (XEXP (bitfield, 1)) == 0)
2626 register rtx memref = 0;
2628 /* Now check that the containing word is memory, not a register,
2629 and that it is safe to change the machine mode. */
2631 if (GET_CODE (XEXP (bitfield, 0)) == MEM)
2632 memref = XEXP (bitfield, 0);
2633 else if (GET_CODE (XEXP (bitfield, 0)) == REG
2635 memref = equiv_mem[REGNO (XEXP (bitfield, 0))];
2636 else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
2637 && GET_CODE (SUBREG_REG (XEXP (bitfield, 0))) == MEM)
2638 memref = SUBREG_REG (XEXP (bitfield, 0));
2639 else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
2641 && GET_CODE (SUBREG_REG (XEXP (bitfield, 0))) == REG)
2642 memref = equiv_mem[REGNO (SUBREG_REG (XEXP (bitfield, 0)))];
2645 && ! mode_dependent_address_p (XEXP (memref, 0))
2646 && ! MEM_VOLATILE_P (memref))
2648 /* Now adjust the address, first for any subreg'ing
2649 that we are now getting rid of,
2650 and then for which byte of the word is wanted. */
2652 HOST_WIDE_INT offset = INTVAL (XEXP (bitfield, 2));
2655 /* Adjust OFFSET to count bits from low-address byte. */
2656 if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN)
2657 offset = (GET_MODE_BITSIZE (GET_MODE (XEXP (bitfield, 0)))
2658 - offset - INTVAL (XEXP (bitfield, 1)));
2660 /* Adjust OFFSET to count bytes from low-address byte. */
2661 offset /= BITS_PER_UNIT;
2662 if (GET_CODE (XEXP (bitfield, 0)) == SUBREG)
2664 offset += SUBREG_WORD (XEXP (bitfield, 0)) * UNITS_PER_WORD;
2665 if (BYTES_BIG_ENDIAN)
2666 offset -= (MIN (UNITS_PER_WORD,
2667 GET_MODE_SIZE (GET_MODE (XEXP (bitfield, 0))))
2668 - MIN (UNITS_PER_WORD,
2669 GET_MODE_SIZE (GET_MODE (memref))));
2673 memref = change_address (memref, mode,
2674 plus_constant (XEXP (memref, 0), offset));
2675 insns = get_insns ();
2677 emit_insns_before (insns, insn);
2679 /* Store this memory reference where
2680 we found the bit field reference. */
2684 validate_change (insn, &SET_DEST (body), memref, 1);
2685 if (! CONSTANT_ADDRESS_P (SET_SRC (body)))
2687 rtx src = SET_SRC (body);
2688 while (GET_CODE (src) == SUBREG
2689 && SUBREG_WORD (src) == 0)
2690 src = SUBREG_REG (src);
2691 if (GET_MODE (src) != GET_MODE (memref))
2692 src = gen_lowpart (GET_MODE (memref), SET_SRC (body));
2693 validate_change (insn, &SET_SRC (body), src, 1);
2695 else if (GET_MODE (SET_SRC (body)) != VOIDmode
2696 && GET_MODE (SET_SRC (body)) != GET_MODE (memref))
2697 /* This shouldn't happen because anything that didn't have
2698 one of these modes should have got converted explicitly
2699 and then referenced through a subreg.
2700 This is so because the original bit-field was
2701 handled by agg_mode and so its tree structure had
2702 the same mode that memref now has. */
2707 rtx dest = SET_DEST (body);
2709 while (GET_CODE (dest) == SUBREG
2710 && SUBREG_WORD (dest) == 0
2711 && (GET_MODE_CLASS (GET_MODE (dest))
2712 == GET_MODE_CLASS (GET_MODE (SUBREG_REG (dest))))
2713 && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest)))
2715 dest = SUBREG_REG (dest);
2717 validate_change (insn, &SET_DEST (body), dest, 1);
2719 if (GET_MODE (dest) == GET_MODE (memref))
2720 validate_change (insn, &SET_SRC (body), memref, 1);
2723 /* Convert the mem ref to the destination mode. */
2724 rtx newreg = gen_reg_rtx (GET_MODE (dest));
2727 convert_move (newreg, memref,
2728 GET_CODE (SET_SRC (body)) == ZERO_EXTRACT);
2732 validate_change (insn, &SET_SRC (body), newreg, 1);
2736 /* See if we can convert this extraction or insertion into
2737 a simple move insn. We might not be able to do so if this
2738 was, for example, part of a PARALLEL.
2740 If we succeed, write out any needed conversions. If we fail,
2741 it is hard to guess why we failed, so don't do anything
2742 special; just let the optimization be suppressed. */
2744 if (apply_change_group () && seq)
2745 emit_insns_before (seq, insn);
2750 /* These routines are responsible for converting virtual register references
2751 to the actual hard register references once RTL generation is complete.
2753 The following four variables are used for communication between the
2754 routines. They contain the offsets of the virtual registers from their
2755 respective hard registers. */
2757 static int in_arg_offset;
2758 static int var_offset;
2759 static int dynamic_offset;
2760 static int out_arg_offset;
2761 static int cfa_offset;
2763 /* In most machines, the stack pointer register is equivalent to the bottom
2766 #ifndef STACK_POINTER_OFFSET
2767 #define STACK_POINTER_OFFSET 0
2770 /* If not defined, pick an appropriate default for the offset of dynamically
2771 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
2772 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
2774 #ifndef STACK_DYNAMIC_OFFSET
2776 /* The bottom of the stack points to the actual arguments. If
2777 REG_PARM_STACK_SPACE is defined, this includes the space for the register
2778 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
2779 stack space for register parameters is not pushed by the caller, but
2780 rather part of the fixed stack areas and hence not included in
2781 `current_function_outgoing_args_size'. Nevertheless, we must allow
2782 for it when allocating stack dynamic objects. */
2784 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
2785 #define STACK_DYNAMIC_OFFSET(FNDECL) \
2786 ((ACCUMULATE_OUTGOING_ARGS \
2787 ? (current_function_outgoing_args_size + REG_PARM_STACK_SPACE (FNDECL)) : 0)\
2788 + (STACK_POINTER_OFFSET)) \
2791 #define STACK_DYNAMIC_OFFSET(FNDECL) \
2792 ((ACCUMULATE_OUTGOING_ARGS ? current_function_outgoing_args_size : 0) \
2793 + (STACK_POINTER_OFFSET))
2797 /* On most machines, the CFA coincides with the first incoming parm. */
2799 #ifndef ARG_POINTER_CFA_OFFSET
2800 #define ARG_POINTER_CFA_OFFSET(FNDECL) FIRST_PARM_OFFSET (FNDECL)
2803 /* Build up a (MEM (ADDRESSOF (REG))) rtx for a register REG that just had
2804 its address taken. DECL is the decl for the object stored in the
2805 register, for later use if we do need to force REG into the stack.
2806 REG is overwritten by the MEM like in put_reg_into_stack. */
2809 gen_mem_addressof (reg, decl)
2813 rtx r = gen_rtx_ADDRESSOF (Pmode, gen_reg_rtx (GET_MODE (reg)),
2816 /* If the original REG was a user-variable, then so is the REG whose
2817 address is being taken. Likewise for unchanging. */
2818 REG_USERVAR_P (XEXP (r, 0)) = REG_USERVAR_P (reg);
2819 RTX_UNCHANGING_P (XEXP (r, 0)) = RTX_UNCHANGING_P (reg);
2821 PUT_CODE (reg, MEM);
2825 tree type = TREE_TYPE (decl);
2827 PUT_MODE (reg, DECL_MODE (decl));
2828 MEM_VOLATILE_P (reg) = TREE_SIDE_EFFECTS (decl);
2829 MEM_SET_IN_STRUCT_P (reg, AGGREGATE_TYPE_P (type));
2830 MEM_ALIAS_SET (reg) = get_alias_set (decl);
2832 if (TREE_USED (decl) || DECL_INITIAL (decl) != 0)
2833 fixup_var_refs (reg, GET_MODE (reg), TREE_UNSIGNED (type), 0);
2836 fixup_var_refs (reg, GET_MODE (reg), 0, 0);
2841 /* If DECL has an RTL that is an ADDRESSOF rtx, put it into the stack. */
2844 flush_addressof (decl)
2847 if ((TREE_CODE (decl) == PARM_DECL || TREE_CODE (decl) == VAR_DECL)
2848 && DECL_RTL (decl) != 0
2849 && GET_CODE (DECL_RTL (decl)) == MEM
2850 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == ADDRESSOF
2851 && GET_CODE (XEXP (XEXP (DECL_RTL (decl), 0), 0)) == REG)
2852 put_addressof_into_stack (XEXP (DECL_RTL (decl), 0), 0);
2855 /* Force the register pointed to by R, an ADDRESSOF rtx, into the stack. */
2858 put_addressof_into_stack (r, ht)
2860 struct hash_table *ht;
2863 int volatile_p, used_p;
2865 rtx reg = XEXP (r, 0);
2867 if (GET_CODE (reg) != REG)
2870 decl = ADDRESSOF_DECL (r);
2873 type = TREE_TYPE (decl);
2874 volatile_p = (TREE_CODE (decl) != SAVE_EXPR
2875 && TREE_THIS_VOLATILE (decl));
2876 used_p = (TREE_USED (decl)
2877 || (TREE_CODE (decl) != SAVE_EXPR
2878 && DECL_INITIAL (decl) != 0));
2887 put_reg_into_stack (0, reg, type, GET_MODE (reg), GET_MODE (reg),
2888 volatile_p, ADDRESSOF_REGNO (r), used_p, ht);
2891 /* List of replacements made below in purge_addressof_1 when creating
2892 bitfield insertions. */
2893 static rtx purge_bitfield_addressof_replacements;
2895 /* List of replacements made below in purge_addressof_1 for patterns
2896 (MEM (ADDRESSOF (REG ...))). The key of the list entry is the
2897 corresponding (ADDRESSOF (REG ...)) and value is a substitution for
2898 the all pattern. List PURGE_BITFIELD_ADDRESSOF_REPLACEMENTS is not
2899 enough in complex cases, e.g. when some field values can be
2900 extracted by usage MEM with narrower mode. */
2901 static rtx purge_addressof_replacements;
2903 /* Helper function for purge_addressof. See if the rtx expression at *LOC
2904 in INSN needs to be changed. If FORCE, always put any ADDRESSOFs into
2905 the stack. If the function returns FALSE then the replacement could not
2909 purge_addressof_1 (loc, insn, force, store, ht)
2913 struct hash_table *ht;
2919 boolean result = true;
2921 /* Re-start here to avoid recursion in common cases. */
2928 code = GET_CODE (x);
2930 /* If we don't return in any of the cases below, we will recurse inside
2931 the RTX, which will normally result in any ADDRESSOF being forced into
2935 result = purge_addressof_1 (&SET_DEST (x), insn, force, 1, ht);
2936 result &= purge_addressof_1 (&SET_SRC (x), insn, force, 0, ht);
2940 else if (code == ADDRESSOF && GET_CODE (XEXP (x, 0)) == MEM)
2942 /* We must create a copy of the rtx because it was created by
2943 overwriting a REG rtx which is always shared. */
2944 rtx sub = copy_rtx (XEXP (XEXP (x, 0), 0));
2947 if (validate_change (insn, loc, sub, 0)
2948 || validate_replace_rtx (x, sub, insn))
2952 sub = force_operand (sub, NULL_RTX);
2953 if (! validate_change (insn, loc, sub, 0)
2954 && ! validate_replace_rtx (x, sub, insn))
2957 insns = gen_sequence ();
2959 emit_insn_before (insns, insn);
2963 else if (code == MEM && GET_CODE (XEXP (x, 0)) == ADDRESSOF && ! force)
2965 rtx sub = XEXP (XEXP (x, 0), 0);
2968 if (GET_CODE (sub) == MEM)
2970 sub2 = gen_rtx_MEM (GET_MODE (x), copy_rtx (XEXP (sub, 0)));
2971 MEM_COPY_ATTRIBUTES (sub2, sub);
2974 else if (GET_CODE (sub) == REG
2975 && (MEM_VOLATILE_P (x) || GET_MODE (x) == BLKmode))
2977 else if (GET_CODE (sub) == REG && GET_MODE (x) != GET_MODE (sub))
2979 int size_x, size_sub;
2983 /* When processing REG_NOTES look at the list of
2984 replacements done on the insn to find the register that X
2988 for (tem = purge_bitfield_addressof_replacements;
2990 tem = XEXP (XEXP (tem, 1), 1))
2991 if (rtx_equal_p (x, XEXP (tem, 0)))
2993 *loc = XEXP (XEXP (tem, 1), 0);
2997 /* See comment for purge_addressof_replacements. */
2998 for (tem = purge_addressof_replacements;
3000 tem = XEXP (XEXP (tem, 1), 1))
3001 if (rtx_equal_p (XEXP (x, 0), XEXP (tem, 0)))
3003 rtx z = XEXP (XEXP (tem, 1), 0);
3005 if (GET_MODE (x) == GET_MODE (z)
3006 || (GET_CODE (XEXP (XEXP (tem, 1), 0)) != REG
3007 && GET_CODE (XEXP (XEXP (tem, 1), 0)) != SUBREG))
3010 /* It can happen that the note may speak of things
3011 in a wider (or just different) mode than the
3012 code did. This is especially true of
3015 if (GET_CODE (z) == SUBREG && SUBREG_WORD (z) == 0)
3018 if (GET_MODE_SIZE (GET_MODE (x)) > UNITS_PER_WORD
3019 && (GET_MODE_SIZE (GET_MODE (x))
3020 > GET_MODE_SIZE (GET_MODE (z))))
3022 /* This can occur as a result in invalid
3023 pointer casts, e.g. float f; ...
3024 *(long long int *)&f.
3025 ??? We could emit a warning here, but
3026 without a line number that wouldn't be
3028 z = gen_rtx_SUBREG (GET_MODE (x), z, 0);
3031 z = gen_lowpart (GET_MODE (x), z);
3037 /* Sometimes we may not be able to find the replacement. For
3038 example when the original insn was a MEM in a wider mode,
3039 and the note is part of a sign extension of a narrowed
3040 version of that MEM. Gcc testcase compile/990829-1.c can
3041 generate an example of this siutation. Rather than complain
3042 we return false, which will prompt our caller to remove the
3047 size_x = GET_MODE_BITSIZE (GET_MODE (x));
3048 size_sub = GET_MODE_BITSIZE (GET_MODE (sub));
3050 /* Don't even consider working with paradoxical subregs,
3051 or the moral equivalent seen here. */
3052 if (size_x <= size_sub
3053 && int_mode_for_mode (GET_MODE (sub)) != BLKmode)
3055 /* Do a bitfield insertion to mirror what would happen
3062 rtx p = PREV_INSN (insn);
3065 val = gen_reg_rtx (GET_MODE (x));
3066 if (! validate_change (insn, loc, val, 0))
3068 /* Discard the current sequence and put the
3069 ADDRESSOF on stack. */
3073 seq = gen_sequence ();
3075 emit_insn_before (seq, insn);
3076 compute_insns_for_mem (p ? NEXT_INSN (p) : get_insns (),
3080 store_bit_field (sub, size_x, 0, GET_MODE (x),
3081 val, GET_MODE_SIZE (GET_MODE (sub)),
3082 GET_MODE_ALIGNMENT (GET_MODE (sub)));
3084 /* Make sure to unshare any shared rtl that store_bit_field
3085 might have created. */
3086 unshare_all_rtl_again (get_insns ());
3088 seq = gen_sequence ();
3090 p = emit_insn_after (seq, insn);
3091 if (NEXT_INSN (insn))
3092 compute_insns_for_mem (NEXT_INSN (insn),
3093 p ? NEXT_INSN (p) : NULL_RTX,
3098 rtx p = PREV_INSN (insn);
3101 val = extract_bit_field (sub, size_x, 0, 1, NULL_RTX,
3102 GET_MODE (x), GET_MODE (x),
3103 GET_MODE_SIZE (GET_MODE (sub)),
3104 GET_MODE_SIZE (GET_MODE (sub)));
3106 if (! validate_change (insn, loc, val, 0))
3108 /* Discard the current sequence and put the
3109 ADDRESSOF on stack. */
3114 seq = gen_sequence ();
3116 emit_insn_before (seq, insn);
3117 compute_insns_for_mem (p ? NEXT_INSN (p) : get_insns (),
3121 /* Remember the replacement so that the same one can be done
3122 on the REG_NOTES. */
3123 purge_bitfield_addressof_replacements
3124 = gen_rtx_EXPR_LIST (VOIDmode, x,
3127 purge_bitfield_addressof_replacements));
3129 /* We replaced with a reg -- all done. */
3134 else if (validate_change (insn, loc, sub, 0))
3136 /* Remember the replacement so that the same one can be done
3137 on the REG_NOTES. */
3138 if (GET_CODE (sub) == REG || GET_CODE (sub) == SUBREG)
3142 for (tem = purge_addressof_replacements;
3144 tem = XEXP (XEXP (tem, 1), 1))
3145 if (rtx_equal_p (XEXP (x, 0), XEXP (tem, 0)))
3147 XEXP (XEXP (tem, 1), 0) = sub;
3150 purge_addressof_replacements
3151 = gen_rtx (EXPR_LIST, VOIDmode, XEXP (x, 0),
3152 gen_rtx_EXPR_LIST (VOIDmode, sub,
3153 purge_addressof_replacements));
3159 /* else give up and put it into the stack */
3162 else if (code == ADDRESSOF)
3164 put_addressof_into_stack (x, ht);
3167 else if (code == SET)
3169 result = purge_addressof_1 (&SET_DEST (x), insn, force, 1, ht);
3170 result &= purge_addressof_1 (&SET_SRC (x), insn, force, 0, ht);
3174 /* Scan all subexpressions. */
3175 fmt = GET_RTX_FORMAT (code);
3176 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
3179 result &= purge_addressof_1 (&XEXP (x, i), insn, force, 0, ht);
3180 else if (*fmt == 'E')
3181 for (j = 0; j < XVECLEN (x, i); j++)
3182 result &= purge_addressof_1 (&XVECEXP (x, i, j), insn, force, 0, ht);
3188 /* Return a new hash table entry in HT. */
3190 static struct hash_entry *
3191 insns_for_mem_newfunc (he, ht, k)
3192 struct hash_entry *he;
3193 struct hash_table *ht;
3194 hash_table_key k ATTRIBUTE_UNUSED;
3196 struct insns_for_mem_entry *ifmhe;
3200 ifmhe = ((struct insns_for_mem_entry *)
3201 hash_allocate (ht, sizeof (struct insns_for_mem_entry)));
3202 ifmhe->insns = NULL_RTX;
3207 /* Return a hash value for K, a REG. */
3209 static unsigned long
3210 insns_for_mem_hash (k)
3213 /* K is really a RTX. Just use the address as the hash value. */
3214 return (unsigned long) k;
3217 /* Return non-zero if K1 and K2 (two REGs) are the same. */
3220 insns_for_mem_comp (k1, k2)
3227 struct insns_for_mem_walk_info {
3228 /* The hash table that we are using to record which INSNs use which
3230 struct hash_table *ht;
3232 /* The INSN we are currently proessing. */
3235 /* Zero if we are walking to find ADDRESSOFs, one if we are walking
3236 to find the insns that use the REGs in the ADDRESSOFs. */
3240 /* Called from compute_insns_for_mem via for_each_rtx. If R is a REG
3241 that might be used in an ADDRESSOF expression, record this INSN in
3242 the hash table given by DATA (which is really a pointer to an
3243 insns_for_mem_walk_info structure). */
3246 insns_for_mem_walk (r, data)
3250 struct insns_for_mem_walk_info *ifmwi
3251 = (struct insns_for_mem_walk_info *) data;
3253 if (ifmwi->pass == 0 && *r && GET_CODE (*r) == ADDRESSOF
3254 && GET_CODE (XEXP (*r, 0)) == REG)
3255 hash_lookup (ifmwi->ht, XEXP (*r, 0), /*create=*/1, /*copy=*/0);
3256 else if (ifmwi->pass == 1 && *r && GET_CODE (*r) == REG)
3258 /* Lookup this MEM in the hashtable, creating it if necessary. */
3259 struct insns_for_mem_entry *ifme
3260 = (struct insns_for_mem_entry *) hash_lookup (ifmwi->ht,
3265 /* If we have not already recorded this INSN, do so now. Since
3266 we process the INSNs in order, we know that if we have
3267 recorded it it must be at the front of the list. */
3268 if (ifme && (!ifme->insns || XEXP (ifme->insns, 0) != ifmwi->insn))
3270 /* We do the allocation on the same obstack as is used for
3271 the hash table since this memory will not be used once
3272 the hash table is deallocated. */
3273 push_obstacks (&ifmwi->ht->memory, &ifmwi->ht->memory);
3274 ifme->insns = gen_rtx_EXPR_LIST (VOIDmode, ifmwi->insn,
3283 /* Walk the INSNS, until we reach LAST_INSN, recording which INSNs use
3284 which REGs in HT. */
3287 compute_insns_for_mem (insns, last_insn, ht)
3290 struct hash_table *ht;
3293 struct insns_for_mem_walk_info ifmwi;
3296 for (ifmwi.pass = 0; ifmwi.pass < 2; ++ifmwi.pass)
3297 for (insn = insns; insn != last_insn; insn = NEXT_INSN (insn))
3301 for_each_rtx (&insn, insns_for_mem_walk, &ifmwi);
3305 /* Helper function for purge_addressof called through for_each_rtx.
3306 Returns true iff the rtl is an ADDRESSOF. */
3308 is_addressof (rtl, data)
3310 void *data ATTRIBUTE_UNUSED;
3312 return GET_CODE (*rtl) == ADDRESSOF;
3315 /* Eliminate all occurrences of ADDRESSOF from INSNS. Elide any remaining
3316 (MEM (ADDRESSOF)) patterns, and force any needed registers into the
3320 purge_addressof (insns)
3324 struct hash_table ht;
3326 /* When we actually purge ADDRESSOFs, we turn REGs into MEMs. That
3327 requires a fixup pass over the instruction stream to correct
3328 INSNs that depended on the REG being a REG, and not a MEM. But,
3329 these fixup passes are slow. Furthermore, most MEMs are not
3330 mentioned in very many instructions. So, we speed up the process
3331 by pre-calculating which REGs occur in which INSNs; that allows
3332 us to perform the fixup passes much more quickly. */
3333 hash_table_init (&ht,
3334 insns_for_mem_newfunc,
3336 insns_for_mem_comp);
3337 compute_insns_for_mem (insns, NULL_RTX, &ht);
3339 for (insn = insns; insn; insn = NEXT_INSN (insn))
3340 if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN
3341 || GET_CODE (insn) == CALL_INSN)
3343 if (! purge_addressof_1 (&PATTERN (insn), insn,
3344 asm_noperands (PATTERN (insn)) > 0, 0, &ht))
3345 /* If we could not replace the ADDRESSOFs in the insn,
3346 something is wrong. */
3349 if (! purge_addressof_1 (®_NOTES (insn), NULL_RTX, 0, 0, &ht))
3351 /* If we could not replace the ADDRESSOFs in the insn's notes,
3352 we can just remove the offending notes instead. */
3355 for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
3357 /* If we find a REG_RETVAL note then the insn is a libcall.
3358 Such insns must have REG_EQUAL notes as well, in order
3359 for later passes of the compiler to work. So it is not
3360 safe to delete the notes here, and instead we abort. */
3361 if (REG_NOTE_KIND (note) == REG_RETVAL)
3363 if (for_each_rtx (¬e, is_addressof, NULL))
3364 remove_note (insn, note);
3370 hash_table_free (&ht);
3371 purge_bitfield_addressof_replacements = 0;
3372 purge_addressof_replacements = 0;
3374 /* REGs are shared. purge_addressof will destructively replace a REG
3375 with a MEM, which creates shared MEMs.
3377 Unfortunately, the children of put_reg_into_stack assume that MEMs
3378 referring to the same stack slot are shared (fixup_var_refs and
3379 the associated hash table code).
3381 So, we have to do another unsharing pass after we have flushed any
3382 REGs that had their address taken into the stack.
3384 It may be worth tracking whether or not we converted any REGs into
3385 MEMs to avoid this overhead when it is not needed. */
3386 unshare_all_rtl_again (get_insns ());
3389 /* Pass through the INSNS of function FNDECL and convert virtual register
3390 references to hard register references. */
3393 instantiate_virtual_regs (fndecl, insns)
3400 /* Compute the offsets to use for this function. */
3401 in_arg_offset = FIRST_PARM_OFFSET (fndecl);
3402 var_offset = STARTING_FRAME_OFFSET;
3403 dynamic_offset = STACK_DYNAMIC_OFFSET (fndecl);
3404 out_arg_offset = STACK_POINTER_OFFSET;
3405 cfa_offset = ARG_POINTER_CFA_OFFSET (fndecl);
3407 /* Scan all variables and parameters of this function. For each that is
3408 in memory, instantiate all virtual registers if the result is a valid
3409 address. If not, we do it later. That will handle most uses of virtual
3410 regs on many machines. */
3411 instantiate_decls (fndecl, 1);
3413 /* Initialize recognition, indicating that volatile is OK. */
3416 /* Scan through all the insns, instantiating every virtual register still
3418 for (insn = insns; insn; insn = NEXT_INSN (insn))
3419 if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN
3420 || GET_CODE (insn) == CALL_INSN)
3422 instantiate_virtual_regs_1 (&PATTERN (insn), insn, 1);
3423 instantiate_virtual_regs_1 (®_NOTES (insn), NULL_RTX, 0);
3426 /* Instantiate the stack slots for the parm registers, for later use in
3427 addressof elimination. */
3428 for (i = 0; i < max_parm_reg; ++i)
3429 if (parm_reg_stack_loc[i])
3430 instantiate_virtual_regs_1 (&parm_reg_stack_loc[i], NULL_RTX, 0);
3432 /* Now instantiate the remaining register equivalences for debugging info.
3433 These will not be valid addresses. */
3434 instantiate_decls (fndecl, 0);
3436 /* Indicate that, from now on, assign_stack_local should use
3437 frame_pointer_rtx. */
3438 virtuals_instantiated = 1;
3441 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
3442 all virtual registers in their DECL_RTL's.
3444 If VALID_ONLY, do this only if the resulting address is still valid.
3445 Otherwise, always do it. */
3448 instantiate_decls (fndecl, valid_only)
3454 if (DECL_SAVED_INSNS (fndecl))
3455 /* When compiling an inline function, the obstack used for
3456 rtl allocation is the maybepermanent_obstack. Calling
3457 `resume_temporary_allocation' switches us back to that
3458 obstack while we process this function's parameters. */
3459 resume_temporary_allocation ();
3461 /* Process all parameters of the function. */
3462 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = TREE_CHAIN (decl))
3464 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (decl));
3466 instantiate_decl (DECL_RTL (decl), size, valid_only);
3468 /* If the parameter was promoted, then the incoming RTL mode may be
3469 larger than the declared type size. We must use the larger of
3471 size = MAX (GET_MODE_SIZE (GET_MODE (DECL_INCOMING_RTL (decl))), size);
3472 instantiate_decl (DECL_INCOMING_RTL (decl), size, valid_only);
3475 /* Now process all variables defined in the function or its subblocks. */
3476 instantiate_decls_1 (DECL_INITIAL (fndecl), valid_only);
3478 if (DECL_INLINE (fndecl) || DECL_DEFER_OUTPUT (fndecl))
3480 /* Save all rtl allocated for this function by raising the
3481 high-water mark on the maybepermanent_obstack. */
3483 /* All further rtl allocation is now done in the current_obstack. */
3484 rtl_in_current_obstack ();
3488 /* Subroutine of instantiate_decls: Process all decls in the given
3489 BLOCK node and all its subblocks. */
3492 instantiate_decls_1 (let, valid_only)
3498 for (t = BLOCK_VARS (let); t; t = TREE_CHAIN (t))
3499 instantiate_decl (DECL_RTL (t), int_size_in_bytes (TREE_TYPE (t)),
3502 /* Process all subblocks. */
3503 for (t = BLOCK_SUBBLOCKS (let); t; t = TREE_CHAIN (t))
3504 instantiate_decls_1 (t, valid_only);
3507 /* Subroutine of the preceding procedures: Given RTL representing a
3508 decl and the size of the object, do any instantiation required.
3510 If VALID_ONLY is non-zero, it means that the RTL should only be
3511 changed if the new address is valid. */
3514 instantiate_decl (x, size, valid_only)
3519 enum machine_mode mode;
3522 /* If this is not a MEM, no need to do anything. Similarly if the
3523 address is a constant or a register that is not a virtual register. */
3525 if (x == 0 || GET_CODE (x) != MEM)
3529 if (CONSTANT_P (addr)
3530 || (GET_CODE (addr) == ADDRESSOF && GET_CODE (XEXP (addr, 0)) == REG)
3531 || (GET_CODE (addr) == REG
3532 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
3533 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
3536 /* If we should only do this if the address is valid, copy the address.
3537 We need to do this so we can undo any changes that might make the
3538 address invalid. This copy is unfortunate, but probably can't be
3542 addr = copy_rtx (addr);
3544 instantiate_virtual_regs_1 (&addr, NULL_RTX, 0);
3546 if (valid_only && size >= 0)
3548 unsigned HOST_WIDE_INT decl_size = size;
3550 /* Now verify that the resulting address is valid for every integer or
3551 floating-point mode up to and including SIZE bytes long. We do this
3552 since the object might be accessed in any mode and frame addresses
3555 for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
3556 mode != VOIDmode && GET_MODE_SIZE (mode) <= decl_size;
3557 mode = GET_MODE_WIDER_MODE (mode))
3558 if (! memory_address_p (mode, addr))
3561 for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT);
3562 mode != VOIDmode && GET_MODE_SIZE (mode) <= decl_size;
3563 mode = GET_MODE_WIDER_MODE (mode))
3564 if (! memory_address_p (mode, addr))
3568 /* Put back the address now that we have updated it and we either know
3569 it is valid or we don't care whether it is valid. */
3574 /* Given a pointer to a piece of rtx and an optional pointer to the
3575 containing object, instantiate any virtual registers present in it.
3577 If EXTRA_INSNS, we always do the replacement and generate
3578 any extra insns before OBJECT. If it zero, we do nothing if replacement
3581 Return 1 if we either had nothing to do or if we were able to do the
3582 needed replacement. Return 0 otherwise; we only return zero if
3583 EXTRA_INSNS is zero.
3585 We first try some simple transformations to avoid the creation of extra
3589 instantiate_virtual_regs_1 (loc, object, extra_insns)
3597 HOST_WIDE_INT offset = 0;
3603 /* Re-start here to avoid recursion in common cases. */
3610 code = GET_CODE (x);
3612 /* Check for some special cases. */
3629 /* We are allowed to set the virtual registers. This means that
3630 the actual register should receive the source minus the
3631 appropriate offset. This is used, for example, in the handling
3632 of non-local gotos. */
3633 if (SET_DEST (x) == virtual_incoming_args_rtx)
3634 new = arg_pointer_rtx, offset = -in_arg_offset;
3635 else if (SET_DEST (x) == virtual_stack_vars_rtx)
3636 new = frame_pointer_rtx, offset = -var_offset;
3637 else if (SET_DEST (x) == virtual_stack_dynamic_rtx)
3638 new = stack_pointer_rtx, offset = -dynamic_offset;
3639 else if (SET_DEST (x) == virtual_outgoing_args_rtx)
3640 new = stack_pointer_rtx, offset = -out_arg_offset;
3641 else if (SET_DEST (x) == virtual_cfa_rtx)
3642 new = arg_pointer_rtx, offset = -cfa_offset;
3646 rtx src = SET_SRC (x);
3648 instantiate_virtual_regs_1 (&src, NULL_RTX, 0);
3650 /* The only valid sources here are PLUS or REG. Just do
3651 the simplest possible thing to handle them. */
3652 if (GET_CODE (src) != REG && GET_CODE (src) != PLUS)
3656 if (GET_CODE (src) != REG)
3657 temp = force_operand (src, NULL_RTX);
3660 temp = force_operand (plus_constant (temp, offset), NULL_RTX);
3664 emit_insns_before (seq, object);
3667 if (! validate_change (object, &SET_SRC (x), temp, 0)
3674 instantiate_virtual_regs_1 (&SET_DEST (x), object, extra_insns);
3679 /* Handle special case of virtual register plus constant. */
3680 if (CONSTANT_P (XEXP (x, 1)))
3682 rtx old, new_offset;
3684 /* Check for (plus (plus VIRT foo) (const_int)) first. */
3685 if (GET_CODE (XEXP (x, 0)) == PLUS)
3687 rtx inner = XEXP (XEXP (x, 0), 0);
3689 if (inner == virtual_incoming_args_rtx)
3690 new = arg_pointer_rtx, offset = in_arg_offset;
3691 else if (inner == virtual_stack_vars_rtx)
3692 new = frame_pointer_rtx, offset = var_offset;
3693 else if (inner == virtual_stack_dynamic_rtx)
3694 new = stack_pointer_rtx, offset = dynamic_offset;
3695 else if (inner == virtual_outgoing_args_rtx)
3696 new = stack_pointer_rtx, offset = out_arg_offset;
3697 else if (inner == virtual_cfa_rtx)
3698 new = arg_pointer_rtx, offset = cfa_offset;
3705 instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 1), object,
3707 new = gen_rtx_PLUS (Pmode, new, XEXP (XEXP (x, 0), 1));
3710 else if (XEXP (x, 0) == virtual_incoming_args_rtx)
3711 new = arg_pointer_rtx, offset = in_arg_offset;
3712 else if (XEXP (x, 0) == virtual_stack_vars_rtx)
3713 new = frame_pointer_rtx, offset = var_offset;
3714 else if (XEXP (x, 0) == virtual_stack_dynamic_rtx)
3715 new = stack_pointer_rtx, offset = dynamic_offset;
3716 else if (XEXP (x, 0) == virtual_outgoing_args_rtx)
3717 new = stack_pointer_rtx, offset = out_arg_offset;
3718 else if (XEXP (x, 0) == virtual_cfa_rtx)
3719 new = arg_pointer_rtx, offset = cfa_offset;
3722 /* We know the second operand is a constant. Unless the
3723 first operand is a REG (which has been already checked),
3724 it needs to be checked. */
3725 if (GET_CODE (XEXP (x, 0)) != REG)
3733 new_offset = plus_constant (XEXP (x, 1), offset);
3735 /* If the new constant is zero, try to replace the sum with just
3737 if (new_offset == const0_rtx
3738 && validate_change (object, loc, new, 0))
3741 /* Next try to replace the register and new offset.
3742 There are two changes to validate here and we can't assume that
3743 in the case of old offset equals new just changing the register
3744 will yield a valid insn. In the interests of a little efficiency,
3745 however, we only call validate change once (we don't queue up the
3746 changes and then call apply_change_group). */
3750 ? ! validate_change (object, &XEXP (x, 0), new, 0)
3751 : (XEXP (x, 0) = new,
3752 ! validate_change (object, &XEXP (x, 1), new_offset, 0)))
3760 /* Otherwise copy the new constant into a register and replace
3761 constant with that register. */
3762 temp = gen_reg_rtx (Pmode);
3764 if (validate_change (object, &XEXP (x, 1), temp, 0))
3765 emit_insn_before (gen_move_insn (temp, new_offset), object);
3768 /* If that didn't work, replace this expression with a
3769 register containing the sum. */
3772 new = gen_rtx_PLUS (Pmode, new, new_offset);
3775 temp = force_operand (new, NULL_RTX);
3779 emit_insns_before (seq, object);
3780 if (! validate_change (object, loc, temp, 0)
3781 && ! validate_replace_rtx (x, temp, object))
3789 /* Fall through to generic two-operand expression case. */
3795 case DIV: case UDIV:
3796 case MOD: case UMOD:
3797 case AND: case IOR: case XOR:
3798 case ROTATERT: case ROTATE:
3799 case ASHIFTRT: case LSHIFTRT: case ASHIFT:
3801 case GE: case GT: case GEU: case GTU:
3802 case LE: case LT: case LEU: case LTU:
3803 if (XEXP (x, 1) && ! CONSTANT_P (XEXP (x, 1)))
3804 instantiate_virtual_regs_1 (&XEXP (x, 1), object, extra_insns);
3809 /* Most cases of MEM that convert to valid addresses have already been
3810 handled by our scan of decls. The only special handling we
3811 need here is to make a copy of the rtx to ensure it isn't being
3812 shared if we have to change it to a pseudo.
3814 If the rtx is a simple reference to an address via a virtual register,
3815 it can potentially be shared. In such cases, first try to make it
3816 a valid address, which can also be shared. Otherwise, copy it and
3819 First check for common cases that need no processing. These are
3820 usually due to instantiation already being done on a previous instance
3824 if (CONSTANT_ADDRESS_P (temp)
3825 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
3826 || temp == arg_pointer_rtx
3828 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
3829 || temp == hard_frame_pointer_rtx
3831 || temp == frame_pointer_rtx)
3834 if (GET_CODE (temp) == PLUS
3835 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
3836 && (XEXP (temp, 0) == frame_pointer_rtx
3837 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
3838 || XEXP (temp, 0) == hard_frame_pointer_rtx
3840 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
3841 || XEXP (temp, 0) == arg_pointer_rtx
3846 if (temp == virtual_stack_vars_rtx
3847 || temp == virtual_incoming_args_rtx
3848 || (GET_CODE (temp) == PLUS
3849 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
3850 && (XEXP (temp, 0) == virtual_stack_vars_rtx
3851 || XEXP (temp, 0) == virtual_incoming_args_rtx)))
3853 /* This MEM may be shared. If the substitution can be done without
3854 the need to generate new pseudos, we want to do it in place
3855 so all copies of the shared rtx benefit. The call below will
3856 only make substitutions if the resulting address is still
3859 Note that we cannot pass X as the object in the recursive call
3860 since the insn being processed may not allow all valid
3861 addresses. However, if we were not passed on object, we can
3862 only modify X without copying it if X will have a valid
3865 ??? Also note that this can still lose if OBJECT is an insn that
3866 has less restrictions on an address that some other insn.
3867 In that case, we will modify the shared address. This case
3868 doesn't seem very likely, though. One case where this could
3869 happen is in the case of a USE or CLOBBER reference, but we
3870 take care of that below. */
3872 if (instantiate_virtual_regs_1 (&XEXP (x, 0),
3873 object ? object : x, 0))
3876 /* Otherwise make a copy and process that copy. We copy the entire
3877 RTL expression since it might be a PLUS which could also be
3879 *loc = x = copy_rtx (x);
3882 /* Fall through to generic unary operation case. */
3884 case STRICT_LOW_PART:
3886 case PRE_DEC: case PRE_INC: case POST_DEC: case POST_INC:
3887 case SIGN_EXTEND: case ZERO_EXTEND:
3888 case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE:
3889 case FLOAT: case FIX:
3890 case UNSIGNED_FIX: case UNSIGNED_FLOAT:
3894 /* These case either have just one operand or we know that we need not
3895 check the rest of the operands. */
3901 /* If the operand is a MEM, see if the change is a valid MEM. If not,
3902 go ahead and make the invalid one, but do it to a copy. For a REG,
3903 just make the recursive call, since there's no chance of a problem. */
3905 if ((GET_CODE (XEXP (x, 0)) == MEM
3906 && instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 0), XEXP (x, 0),
3908 || (GET_CODE (XEXP (x, 0)) == REG
3909 && instantiate_virtual_regs_1 (&XEXP (x, 0), object, 0)))
3912 XEXP (x, 0) = copy_rtx (XEXP (x, 0));
3917 /* Try to replace with a PLUS. If that doesn't work, compute the sum
3918 in front of this insn and substitute the temporary. */
3919 if (x == virtual_incoming_args_rtx)
3920 new = arg_pointer_rtx, offset = in_arg_offset;
3921 else if (x == virtual_stack_vars_rtx)
3922 new = frame_pointer_rtx, offset = var_offset;
3923 else if (x == virtual_stack_dynamic_rtx)
3924 new = stack_pointer_rtx, offset = dynamic_offset;
3925 else if (x == virtual_outgoing_args_rtx)
3926 new = stack_pointer_rtx, offset = out_arg_offset;
3927 else if (x == virtual_cfa_rtx)
3928 new = arg_pointer_rtx, offset = cfa_offset;
3932 temp = plus_constant (new, offset);
3933 if (!validate_change (object, loc, temp, 0))
3939 temp = force_operand (temp, NULL_RTX);
3943 emit_insns_before (seq, object);
3944 if (! validate_change (object, loc, temp, 0)
3945 && ! validate_replace_rtx (x, temp, object))
3953 if (GET_CODE (XEXP (x, 0)) == REG)
3956 else if (GET_CODE (XEXP (x, 0)) == MEM)
3958 /* If we have a (addressof (mem ..)), do any instantiation inside
3959 since we know we'll be making the inside valid when we finally
3960 remove the ADDRESSOF. */
3961 instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 0), NULL_RTX, 0);
3970 /* Scan all subexpressions. */
3971 fmt = GET_RTX_FORMAT (code);
3972 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
3975 if (!instantiate_virtual_regs_1 (&XEXP (x, i), object, extra_insns))
3978 else if (*fmt == 'E')
3979 for (j = 0; j < XVECLEN (x, i); j++)
3980 if (! instantiate_virtual_regs_1 (&XVECEXP (x, i, j), object,
3987 /* Optimization: assuming this function does not receive nonlocal gotos,
3988 delete the handlers for such, as well as the insns to establish
3989 and disestablish them. */
3995 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3997 /* Delete the handler by turning off the flag that would
3998 prevent jump_optimize from deleting it.
3999 Also permit deletion of the nonlocal labels themselves
4000 if nothing local refers to them. */
4001 if (GET_CODE (insn) == CODE_LABEL)
4005 LABEL_PRESERVE_P (insn) = 0;
4007 /* Remove it from the nonlocal_label list, to avoid confusing
4009 for (t = nonlocal_labels, last_t = 0; t;
4010 last_t = t, t = TREE_CHAIN (t))
4011 if (DECL_RTL (TREE_VALUE (t)) == insn)
4016 nonlocal_labels = TREE_CHAIN (nonlocal_labels);
4018 TREE_CHAIN (last_t) = TREE_CHAIN (t);
4021 if (GET_CODE (insn) == INSN)
4025 for (t = nonlocal_goto_handler_slots; t != 0; t = XEXP (t, 1))
4026 if (reg_mentioned_p (t, PATTERN (insn)))
4032 || (nonlocal_goto_stack_level != 0
4033 && reg_mentioned_p (nonlocal_goto_stack_level,
4043 return max_parm_reg;
4046 /* Return the first insn following those generated by `assign_parms'. */
4049 get_first_nonparm_insn ()
4052 return NEXT_INSN (last_parm_insn);
4053 return get_insns ();
4056 /* Return the first NOTE_INSN_BLOCK_BEG note in the function.
4057 Crash if there is none. */
4060 get_first_block_beg ()
4062 register rtx searcher;
4063 register rtx insn = get_first_nonparm_insn ();
4065 for (searcher = insn; searcher; searcher = NEXT_INSN (searcher))
4066 if (GET_CODE (searcher) == NOTE
4067 && NOTE_LINE_NUMBER (searcher) == NOTE_INSN_BLOCK_BEG)
4070 abort (); /* Invalid call to this function. (See comments above.) */
4074 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
4075 This means a type for which function calls must pass an address to the
4076 function or get an address back from the function.
4077 EXP may be a type node or an expression (whose type is tested). */
4080 aggregate_value_p (exp)
4083 int i, regno, nregs;
4086 tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
4088 if (TREE_CODE (type) == VOID_TYPE)
4090 if (RETURN_IN_MEMORY (type))
4092 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
4093 and thus can't be returned in registers. */
4094 if (TREE_ADDRESSABLE (type))
4096 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
4098 /* Make sure we have suitable call-clobbered regs to return
4099 the value in; if not, we must return it in memory. */
4100 reg = hard_function_value (type, 0, 0);
4102 /* If we have something other than a REG (e.g. a PARALLEL), then assume
4104 if (GET_CODE (reg) != REG)
4107 regno = REGNO (reg);
4108 nregs = HARD_REGNO_NREGS (regno, TYPE_MODE (type));
4109 for (i = 0; i < nregs; i++)
4110 if (! call_used_regs[regno + i])
4115 /* Assign RTL expressions to the function's parameters.
4116 This may involve copying them into registers and using
4117 those registers as the RTL for them. */
4120 assign_parms (fndecl)
4124 register rtx entry_parm = 0;
4125 register rtx stack_parm = 0;
4126 CUMULATIVE_ARGS args_so_far;
4127 enum machine_mode promoted_mode, passed_mode;
4128 enum machine_mode nominal_mode, promoted_nominal_mode;
4130 /* Total space needed so far for args on the stack,
4131 given as a constant and a tree-expression. */
4132 struct args_size stack_args_size;
4133 tree fntype = TREE_TYPE (fndecl);
4134 tree fnargs = DECL_ARGUMENTS (fndecl);
4135 /* This is used for the arg pointer when referring to stack args. */
4136 rtx internal_arg_pointer;
4137 /* This is a dummy PARM_DECL that we used for the function result if
4138 the function returns a structure. */
4139 tree function_result_decl = 0;
4140 #ifdef SETUP_INCOMING_VARARGS
4141 int varargs_setup = 0;
4143 rtx conversion_insns = 0;
4144 struct args_size alignment_pad;
4146 /* Nonzero if the last arg is named `__builtin_va_alist',
4147 which is used on some machines for old-fashioned non-ANSI varargs.h;
4148 this should be stuck onto the stack as if it had arrived there. */
4150 = (current_function_varargs
4152 && (parm = tree_last (fnargs)) != 0
4154 && (! strcmp (IDENTIFIER_POINTER (DECL_NAME (parm)),
4155 "__builtin_va_alist")));
4157 /* Nonzero if function takes extra anonymous args.
4158 This means the last named arg must be on the stack
4159 right before the anonymous ones. */
4161 = (TYPE_ARG_TYPES (fntype) != 0
4162 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
4163 != void_type_node));
4165 current_function_stdarg = stdarg;
4167 /* If the reg that the virtual arg pointer will be translated into is
4168 not a fixed reg or is the stack pointer, make a copy of the virtual
4169 arg pointer, and address parms via the copy. The frame pointer is
4170 considered fixed even though it is not marked as such.
4172 The second time through, simply use ap to avoid generating rtx. */
4174 if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
4175 || ! (fixed_regs[ARG_POINTER_REGNUM]
4176 || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
4177 internal_arg_pointer = copy_to_reg (virtual_incoming_args_rtx);
4179 internal_arg_pointer = virtual_incoming_args_rtx;
4180 current_function_internal_arg_pointer = internal_arg_pointer;
4182 stack_args_size.constant = 0;
4183 stack_args_size.var = 0;
4185 /* If struct value address is treated as the first argument, make it so. */
4186 if (aggregate_value_p (DECL_RESULT (fndecl))
4187 && ! current_function_returns_pcc_struct
4188 && struct_value_incoming_rtx == 0)
4190 tree type = build_pointer_type (TREE_TYPE (fntype));
4192 function_result_decl = build_decl (PARM_DECL, NULL_TREE, type);
4194 DECL_ARG_TYPE (function_result_decl) = type;
4195 TREE_CHAIN (function_result_decl) = fnargs;
4196 fnargs = function_result_decl;
4199 max_parm_reg = LAST_VIRTUAL_REGISTER + 1;
4200 parm_reg_stack_loc = (rtx *) xcalloc (max_parm_reg, sizeof (rtx));
4202 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
4203 INIT_CUMULATIVE_INCOMING_ARGS (args_so_far, fntype, NULL_RTX);
4205 INIT_CUMULATIVE_ARGS (args_so_far, fntype, NULL_RTX, 0);
4208 /* We haven't yet found an argument that we must push and pretend the
4210 current_function_pretend_args_size = 0;
4212 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
4214 struct args_size stack_offset;
4215 struct args_size arg_size;
4216 int passed_pointer = 0;
4217 int did_conversion = 0;
4218 tree passed_type = DECL_ARG_TYPE (parm);
4219 tree nominal_type = TREE_TYPE (parm);
4222 /* Set LAST_NAMED if this is last named arg before some
4224 int last_named = ((TREE_CHAIN (parm) == 0
4225 || DECL_NAME (TREE_CHAIN (parm)) == 0)
4226 && (stdarg || current_function_varargs));
4227 /* Set NAMED_ARG if this arg should be treated as a named arg. For
4228 most machines, if this is a varargs/stdarg function, then we treat
4229 the last named arg as if it were anonymous too. */
4230 int named_arg = STRICT_ARGUMENT_NAMING ? 1 : ! last_named;
4232 if (TREE_TYPE (parm) == error_mark_node
4233 /* This can happen after weird syntax errors
4234 or if an enum type is defined among the parms. */
4235 || TREE_CODE (parm) != PARM_DECL
4236 || passed_type == NULL)
4238 DECL_INCOMING_RTL (parm) = DECL_RTL (parm)
4239 = gen_rtx_MEM (BLKmode, const0_rtx);
4240 TREE_USED (parm) = 1;
4244 /* For varargs.h function, save info about regs and stack space
4245 used by the individual args, not including the va_alist arg. */
4246 if (hide_last_arg && last_named)
4247 current_function_args_info = args_so_far;
4249 /* Find mode of arg as it is passed, and mode of arg
4250 as it should be during execution of this function. */
4251 passed_mode = TYPE_MODE (passed_type);
4252 nominal_mode = TYPE_MODE (nominal_type);
4254 /* If the parm's mode is VOID, its value doesn't matter,
4255 and avoid the usual things like emit_move_insn that could crash. */
4256 if (nominal_mode == VOIDmode)
4258 DECL_INCOMING_RTL (parm) = DECL_RTL (parm) = const0_rtx;
4262 /* If the parm is to be passed as a transparent union, use the
4263 type of the first field for the tests below. We have already
4264 verified that the modes are the same. */
4265 if (DECL_TRANSPARENT_UNION (parm)
4266 || (TREE_CODE (passed_type) == UNION_TYPE
4267 && TYPE_TRANSPARENT_UNION (passed_type)))
4268 passed_type = TREE_TYPE (TYPE_FIELDS (passed_type));
4270 /* See if this arg was passed by invisible reference. It is if
4271 it is an object whose size depends on the contents of the
4272 object itself or if the machine requires these objects be passed
4275 if ((TREE_CODE (TYPE_SIZE (passed_type)) != INTEGER_CST
4276 && contains_placeholder_p (TYPE_SIZE (passed_type)))
4277 || TREE_ADDRESSABLE (passed_type)
4278 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
4279 || FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, passed_mode,
4280 passed_type, named_arg)
4284 passed_type = nominal_type = build_pointer_type (passed_type);
4286 passed_mode = nominal_mode = Pmode;
4289 promoted_mode = passed_mode;
4291 #ifdef PROMOTE_FUNCTION_ARGS
4292 /* Compute the mode in which the arg is actually extended to. */
4293 unsignedp = TREE_UNSIGNED (passed_type);
4294 promoted_mode = promote_mode (passed_type, promoted_mode, &unsignedp, 1);
4297 /* Let machine desc say which reg (if any) the parm arrives in.
4298 0 means it arrives on the stack. */
4299 #ifdef FUNCTION_INCOMING_ARG
4300 entry_parm = FUNCTION_INCOMING_ARG (args_so_far, promoted_mode,
4301 passed_type, named_arg);
4303 entry_parm = FUNCTION_ARG (args_so_far, promoted_mode,
4304 passed_type, named_arg);
4307 if (entry_parm == 0)
4308 promoted_mode = passed_mode;
4310 #ifdef SETUP_INCOMING_VARARGS
4311 /* If this is the last named parameter, do any required setup for
4312 varargs or stdargs. We need to know about the case of this being an
4313 addressable type, in which case we skip the registers it
4314 would have arrived in.
4316 For stdargs, LAST_NAMED will be set for two parameters, the one that
4317 is actually the last named, and the dummy parameter. We only
4318 want to do this action once.
4320 Also, indicate when RTL generation is to be suppressed. */
4321 if (last_named && !varargs_setup)
4323 SETUP_INCOMING_VARARGS (args_so_far, promoted_mode, passed_type,
4324 current_function_pretend_args_size, 0);
4329 /* Determine parm's home in the stack,
4330 in case it arrives in the stack or we should pretend it did.
4332 Compute the stack position and rtx where the argument arrives
4335 There is one complexity here: If this was a parameter that would
4336 have been passed in registers, but wasn't only because it is
4337 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
4338 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
4339 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of
4340 0 as it was the previous time. */
4342 pretend_named = named_arg || PRETEND_OUTGOING_VARARGS_NAMED;
4343 locate_and_pad_parm (promoted_mode, passed_type,
4344 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4347 #ifdef FUNCTION_INCOMING_ARG
4348 FUNCTION_INCOMING_ARG (args_so_far, promoted_mode,
4350 pretend_named) != 0,
4352 FUNCTION_ARG (args_so_far, promoted_mode,
4354 pretend_named) != 0,
4357 fndecl, &stack_args_size, &stack_offset, &arg_size,
4361 rtx offset_rtx = ARGS_SIZE_RTX (stack_offset);
4363 if (offset_rtx == const0_rtx)
4364 stack_parm = gen_rtx_MEM (promoted_mode, internal_arg_pointer);
4366 stack_parm = gen_rtx_MEM (promoted_mode,
4367 gen_rtx_PLUS (Pmode,
4368 internal_arg_pointer,
4371 set_mem_attributes (stack_parm, parm, 1);
4374 /* If this parameter was passed both in registers and in the stack,
4375 use the copy on the stack. */
4376 if (MUST_PASS_IN_STACK (promoted_mode, passed_type))
4379 #ifdef FUNCTION_ARG_PARTIAL_NREGS
4380 /* If this parm was passed part in regs and part in memory,
4381 pretend it arrived entirely in memory
4382 by pushing the register-part onto the stack.
4384 In the special case of a DImode or DFmode that is split,
4385 we could put it together in a pseudoreg directly,
4386 but for now that's not worth bothering with. */
4390 int nregs = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, promoted_mode,
4391 passed_type, named_arg);
4395 current_function_pretend_args_size
4396 = (((nregs * UNITS_PER_WORD) + (PARM_BOUNDARY / BITS_PER_UNIT) - 1)
4397 / (PARM_BOUNDARY / BITS_PER_UNIT)
4398 * (PARM_BOUNDARY / BITS_PER_UNIT));
4400 /* Handle calls that pass values in multiple non-contiguous
4401 locations. The Irix 6 ABI has examples of this. */
4402 if (GET_CODE (entry_parm) == PARALLEL)
4403 emit_group_store (validize_mem (stack_parm), entry_parm,
4404 int_size_in_bytes (TREE_TYPE (parm)),
4405 TYPE_ALIGN (TREE_TYPE (parm)));
4408 move_block_from_reg (REGNO (entry_parm),
4409 validize_mem (stack_parm), nregs,
4410 int_size_in_bytes (TREE_TYPE (parm)));
4412 entry_parm = stack_parm;
4417 /* If we didn't decide this parm came in a register,
4418 by default it came on the stack. */
4419 if (entry_parm == 0)
4420 entry_parm = stack_parm;
4422 /* Record permanently how this parm was passed. */
4423 DECL_INCOMING_RTL (parm) = entry_parm;
4425 /* If there is actually space on the stack for this parm,
4426 count it in stack_args_size; otherwise set stack_parm to 0
4427 to indicate there is no preallocated stack slot for the parm. */
4429 if (entry_parm == stack_parm
4430 || (GET_CODE (entry_parm) == PARALLEL
4431 && XEXP (XVECEXP (entry_parm, 0, 0), 0) == NULL_RTX)
4432 #if defined (REG_PARM_STACK_SPACE) && ! defined (MAYBE_REG_PARM_STACK_SPACE)
4433 /* On some machines, even if a parm value arrives in a register
4434 there is still an (uninitialized) stack slot allocated for it.
4436 ??? When MAYBE_REG_PARM_STACK_SPACE is defined, we can't tell
4437 whether this parameter already has a stack slot allocated,
4438 because an arg block exists only if current_function_args_size
4439 is larger than some threshold, and we haven't calculated that
4440 yet. So, for now, we just assume that stack slots never exist
4442 || REG_PARM_STACK_SPACE (fndecl) > 0
4446 stack_args_size.constant += arg_size.constant;
4448 ADD_PARM_SIZE (stack_args_size, arg_size.var);
4451 /* No stack slot was pushed for this parm. */
4454 /* Update info on where next arg arrives in registers. */
4456 FUNCTION_ARG_ADVANCE (args_so_far, promoted_mode,
4457 passed_type, named_arg);
4459 /* If we can't trust the parm stack slot to be aligned enough
4460 for its ultimate type, don't use that slot after entry.
4461 We'll make another stack slot, if we need one. */
4463 unsigned int thisparm_boundary
4464 = FUNCTION_ARG_BOUNDARY (promoted_mode, passed_type);
4466 if (GET_MODE_ALIGNMENT (nominal_mode) > thisparm_boundary)
4470 /* If parm was passed in memory, and we need to convert it on entry,
4471 don't store it back in that same slot. */
4473 && nominal_mode != BLKmode && nominal_mode != passed_mode)
4476 /* ENTRY_PARM is an RTX for the parameter as it arrives,
4477 in the mode in which it arrives.
4478 STACK_PARM is an RTX for a stack slot where the parameter can live
4479 during the function (in case we want to put it there).
4480 STACK_PARM is 0 if no stack slot was pushed for it.
4482 Now output code if necessary to convert ENTRY_PARM to
4483 the type in which this function declares it,
4484 and store that result in an appropriate place,
4485 which may be a pseudo reg, may be STACK_PARM,
4486 or may be a local stack slot if STACK_PARM is 0.
4488 Set DECL_RTL to that place. */
4490 if (nominal_mode == BLKmode || GET_CODE (entry_parm) == PARALLEL)
4492 /* If a BLKmode arrives in registers, copy it to a stack slot.
4493 Handle calls that pass values in multiple non-contiguous
4494 locations. The Irix 6 ABI has examples of this. */
4495 if (GET_CODE (entry_parm) == REG
4496 || GET_CODE (entry_parm) == PARALLEL)
4499 = CEIL_ROUND (int_size_in_bytes (TREE_TYPE (parm)),
4502 /* Note that we will be storing an integral number of words.
4503 So we have to be careful to ensure that we allocate an
4504 integral number of words. We do this below in the
4505 assign_stack_local if space was not allocated in the argument
4506 list. If it was, this will not work if PARM_BOUNDARY is not
4507 a multiple of BITS_PER_WORD. It isn't clear how to fix this
4508 if it becomes a problem. */
4510 if (stack_parm == 0)
4513 = assign_stack_local (GET_MODE (entry_parm),
4515 set_mem_attributes (stack_parm, parm, 1);
4518 else if (PARM_BOUNDARY % BITS_PER_WORD != 0)
4521 /* Handle calls that pass values in multiple non-contiguous
4522 locations. The Irix 6 ABI has examples of this. */
4523 if (GET_CODE (entry_parm) == PARALLEL)
4524 emit_group_store (validize_mem (stack_parm), entry_parm,
4525 int_size_in_bytes (TREE_TYPE (parm)),
4526 TYPE_ALIGN (TREE_TYPE (parm)));
4528 move_block_from_reg (REGNO (entry_parm),
4529 validize_mem (stack_parm),
4530 size_stored / UNITS_PER_WORD,
4531 int_size_in_bytes (TREE_TYPE (parm)));
4533 DECL_RTL (parm) = stack_parm;
4535 else if (! ((! optimize
4536 && ! DECL_REGISTER (parm)
4537 && ! DECL_INLINE (fndecl))
4538 /* layout_decl may set this. */
4539 || TREE_ADDRESSABLE (parm)
4540 || TREE_SIDE_EFFECTS (parm)
4541 /* If -ffloat-store specified, don't put explicit
4542 float variables into registers. */
4543 || (flag_float_store
4544 && TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE))
4545 /* Always assign pseudo to structure return or item passed
4546 by invisible reference. */
4547 || passed_pointer || parm == function_result_decl)
4549 /* Store the parm in a pseudoregister during the function, but we
4550 may need to do it in a wider mode. */
4552 register rtx parmreg;
4553 unsigned int regno, regnoi = 0, regnor = 0;
4555 unsignedp = TREE_UNSIGNED (TREE_TYPE (parm));
4557 promoted_nominal_mode
4558 = promote_mode (TREE_TYPE (parm), nominal_mode, &unsignedp, 0);
4560 parmreg = gen_reg_rtx (promoted_nominal_mode);
4561 mark_user_reg (parmreg);
4563 /* If this was an item that we received a pointer to, set DECL_RTL
4568 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (passed_type)), parmreg);
4569 set_mem_attributes (DECL_RTL (parm), parm, 1);
4572 DECL_RTL (parm) = parmreg;
4574 /* Copy the value into the register. */
4575 if (nominal_mode != passed_mode
4576 || promoted_nominal_mode != promoted_mode)
4579 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
4580 mode, by the caller. We now have to convert it to
4581 NOMINAL_MODE, if different. However, PARMREG may be in
4582 a different mode than NOMINAL_MODE if it is being stored
4585 If ENTRY_PARM is a hard register, it might be in a register
4586 not valid for operating in its mode (e.g., an odd-numbered
4587 register for a DFmode). In that case, moves are the only
4588 thing valid, so we can't do a convert from there. This
4589 occurs when the calling sequence allow such misaligned
4592 In addition, the conversion may involve a call, which could
4593 clobber parameters which haven't been copied to pseudo
4594 registers yet. Therefore, we must first copy the parm to
4595 a pseudo reg here, and save the conversion until after all
4596 parameters have been moved. */
4598 rtx tempreg = gen_reg_rtx (GET_MODE (entry_parm));
4600 emit_move_insn (tempreg, validize_mem (entry_parm));
4602 push_to_sequence (conversion_insns);
4603 tempreg = convert_to_mode (nominal_mode, tempreg, unsignedp);
4605 /* TREE_USED gets set erroneously during expand_assignment. */
4606 save_tree_used = TREE_USED (parm);
4607 expand_assignment (parm,
4608 make_tree (nominal_type, tempreg), 0, 0);
4609 TREE_USED (parm) = save_tree_used;
4610 conversion_insns = get_insns ();
4615 emit_move_insn (parmreg, validize_mem (entry_parm));
4617 /* If we were passed a pointer but the actual value
4618 can safely live in a register, put it in one. */
4619 if (passed_pointer && TYPE_MODE (TREE_TYPE (parm)) != BLKmode
4621 && ! DECL_REGISTER (parm)
4622 && ! DECL_INLINE (fndecl))
4623 /* layout_decl may set this. */
4624 || TREE_ADDRESSABLE (parm)
4625 || TREE_SIDE_EFFECTS (parm)
4626 /* If -ffloat-store specified, don't put explicit
4627 float variables into registers. */
4628 || (flag_float_store
4629 && TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE)))
4631 /* We can't use nominal_mode, because it will have been set to
4632 Pmode above. We must use the actual mode of the parm. */
4633 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
4634 mark_user_reg (parmreg);
4635 emit_move_insn (parmreg, DECL_RTL (parm));
4636 DECL_RTL (parm) = parmreg;
4637 /* STACK_PARM is the pointer, not the parm, and PARMREG is
4641 #ifdef FUNCTION_ARG_CALLEE_COPIES
4642 /* If we are passed an arg by reference and it is our responsibility
4643 to make a copy, do it now.
4644 PASSED_TYPE and PASSED mode now refer to the pointer, not the
4645 original argument, so we must recreate them in the call to
4646 FUNCTION_ARG_CALLEE_COPIES. */
4647 /* ??? Later add code to handle the case that if the argument isn't
4648 modified, don't do the copy. */
4650 else if (passed_pointer
4651 && FUNCTION_ARG_CALLEE_COPIES (args_so_far,
4652 TYPE_MODE (DECL_ARG_TYPE (parm)),
4653 DECL_ARG_TYPE (parm),
4655 && ! TREE_ADDRESSABLE (DECL_ARG_TYPE (parm)))
4658 tree type = DECL_ARG_TYPE (parm);
4660 /* This sequence may involve a library call perhaps clobbering
4661 registers that haven't been copied to pseudos yet. */
4663 push_to_sequence (conversion_insns);
4665 if (!COMPLETE_TYPE_P (type)
4666 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4667 /* This is a variable sized object. */
4668 copy = gen_rtx_MEM (BLKmode,
4669 allocate_dynamic_stack_space
4670 (expr_size (parm), NULL_RTX,
4671 TYPE_ALIGN (type)));
4673 copy = assign_stack_temp (TYPE_MODE (type),
4674 int_size_in_bytes (type), 1);
4675 set_mem_attributes (copy, parm, 1);
4677 store_expr (parm, copy, 0);
4678 emit_move_insn (parmreg, XEXP (copy, 0));
4679 if (current_function_check_memory_usage)
4680 emit_library_call (chkr_set_right_libfunc, 1, VOIDmode, 3,
4681 XEXP (copy, 0), Pmode,
4682 GEN_INT (int_size_in_bytes (type)),
4683 TYPE_MODE (sizetype),
4684 GEN_INT (MEMORY_USE_RW),
4685 TYPE_MODE (integer_type_node));
4686 conversion_insns = get_insns ();
4690 #endif /* FUNCTION_ARG_CALLEE_COPIES */
4692 /* In any case, record the parm's desired stack location
4693 in case we later discover it must live in the stack.
4695 If it is a COMPLEX value, store the stack location for both
4698 if (GET_CODE (parmreg) == CONCAT)
4699 regno = MAX (REGNO (XEXP (parmreg, 0)), REGNO (XEXP (parmreg, 1)));
4701 regno = REGNO (parmreg);
4703 if (regno >= max_parm_reg)
4706 int old_max_parm_reg = max_parm_reg;
4708 /* It's slow to expand this one register at a time,
4709 but it's also rare and we need max_parm_reg to be
4710 precisely correct. */
4711 max_parm_reg = regno + 1;
4712 new = (rtx *) xrealloc (parm_reg_stack_loc,
4713 max_parm_reg * sizeof (rtx));
4714 bzero ((char *) (new + old_max_parm_reg),
4715 (max_parm_reg - old_max_parm_reg) * sizeof (rtx));
4716 parm_reg_stack_loc = new;
4719 if (GET_CODE (parmreg) == CONCAT)
4721 enum machine_mode submode = GET_MODE (XEXP (parmreg, 0));
4723 regnor = REGNO (gen_realpart (submode, parmreg));
4724 regnoi = REGNO (gen_imagpart (submode, parmreg));
4726 if (stack_parm != 0)
4728 parm_reg_stack_loc[regnor]
4729 = gen_realpart (submode, stack_parm);
4730 parm_reg_stack_loc[regnoi]
4731 = gen_imagpart (submode, stack_parm);
4735 parm_reg_stack_loc[regnor] = 0;
4736 parm_reg_stack_loc[regnoi] = 0;
4740 parm_reg_stack_loc[REGNO (parmreg)] = stack_parm;
4742 /* Mark the register as eliminable if we did no conversion
4743 and it was copied from memory at a fixed offset,
4744 and the arg pointer was not copied to a pseudo-reg.
4745 If the arg pointer is a pseudo reg or the offset formed
4746 an invalid address, such memory-equivalences
4747 as we make here would screw up life analysis for it. */
4748 if (nominal_mode == passed_mode
4751 && GET_CODE (stack_parm) == MEM
4752 && stack_offset.var == 0
4753 && reg_mentioned_p (virtual_incoming_args_rtx,
4754 XEXP (stack_parm, 0)))
4756 rtx linsn = get_last_insn ();
4759 /* Mark complex types separately. */
4760 if (GET_CODE (parmreg) == CONCAT)
4761 /* Scan backwards for the set of the real and
4763 for (sinsn = linsn; sinsn != 0;
4764 sinsn = prev_nonnote_insn (sinsn))
4766 set = single_set (sinsn);
4768 && SET_DEST (set) == regno_reg_rtx [regnoi])
4770 = gen_rtx_EXPR_LIST (REG_EQUIV,
4771 parm_reg_stack_loc[regnoi],
4774 && SET_DEST (set) == regno_reg_rtx [regnor])
4776 = gen_rtx_EXPR_LIST (REG_EQUIV,
4777 parm_reg_stack_loc[regnor],
4780 else if ((set = single_set (linsn)) != 0
4781 && SET_DEST (set) == parmreg)
4783 = gen_rtx_EXPR_LIST (REG_EQUIV,
4784 stack_parm, REG_NOTES (linsn));
4787 /* For pointer data type, suggest pointer register. */
4788 if (POINTER_TYPE_P (TREE_TYPE (parm)))
4789 mark_reg_pointer (parmreg,
4790 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
4795 /* Value must be stored in the stack slot STACK_PARM
4796 during function execution. */
4798 if (promoted_mode != nominal_mode)
4800 /* Conversion is required. */
4801 rtx tempreg = gen_reg_rtx (GET_MODE (entry_parm));
4803 emit_move_insn (tempreg, validize_mem (entry_parm));
4805 push_to_sequence (conversion_insns);
4806 entry_parm = convert_to_mode (nominal_mode, tempreg,
4807 TREE_UNSIGNED (TREE_TYPE (parm)));
4810 /* ??? This may need a big-endian conversion on sparc64. */
4811 stack_parm = change_address (stack_parm, nominal_mode,
4814 conversion_insns = get_insns ();
4819 if (entry_parm != stack_parm)
4821 if (stack_parm == 0)
4824 = assign_stack_local (GET_MODE (entry_parm),
4825 GET_MODE_SIZE (GET_MODE (entry_parm)), 0);
4826 set_mem_attributes (stack_parm, parm, 1);
4829 if (promoted_mode != nominal_mode)
4831 push_to_sequence (conversion_insns);
4832 emit_move_insn (validize_mem (stack_parm),
4833 validize_mem (entry_parm));
4834 conversion_insns = get_insns ();
4838 emit_move_insn (validize_mem (stack_parm),
4839 validize_mem (entry_parm));
4841 if (current_function_check_memory_usage)
4843 push_to_sequence (conversion_insns);
4844 emit_library_call (chkr_set_right_libfunc, 1, VOIDmode, 3,
4845 XEXP (stack_parm, 0), Pmode,
4846 GEN_INT (GET_MODE_SIZE (GET_MODE
4848 TYPE_MODE (sizetype),
4849 GEN_INT (MEMORY_USE_RW),
4850 TYPE_MODE (integer_type_node));
4852 conversion_insns = get_insns ();
4855 DECL_RTL (parm) = stack_parm;
4858 /* If this "parameter" was the place where we are receiving the
4859 function's incoming structure pointer, set up the result. */
4860 if (parm == function_result_decl)
4862 tree result = DECL_RESULT (fndecl);
4865 = gen_rtx_MEM (DECL_MODE (result), DECL_RTL (parm));
4867 set_mem_attributes (DECL_RTL (result), result, 1);
4871 /* Output all parameter conversion instructions (possibly including calls)
4872 now that all parameters have been copied out of hard registers. */
4873 emit_insns (conversion_insns);
4875 last_parm_insn = get_last_insn ();
4877 current_function_args_size = stack_args_size.constant;
4879 /* Adjust function incoming argument size for alignment and
4882 #ifdef REG_PARM_STACK_SPACE
4883 #ifndef MAYBE_REG_PARM_STACK_SPACE
4884 current_function_args_size = MAX (current_function_args_size,
4885 REG_PARM_STACK_SPACE (fndecl));
4889 #ifdef STACK_BOUNDARY
4890 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
4892 current_function_args_size
4893 = ((current_function_args_size + STACK_BYTES - 1)
4894 / STACK_BYTES) * STACK_BYTES;
4897 #ifdef ARGS_GROW_DOWNWARD
4898 current_function_arg_offset_rtx
4899 = (stack_args_size.var == 0 ? GEN_INT (-stack_args_size.constant)
4900 : expand_expr (size_diffop (stack_args_size.var,
4901 size_int (-stack_args_size.constant)),
4902 NULL_RTX, VOIDmode, EXPAND_MEMORY_USE_BAD));
4904 current_function_arg_offset_rtx = ARGS_SIZE_RTX (stack_args_size);
4907 /* See how many bytes, if any, of its args a function should try to pop
4910 current_function_pops_args = RETURN_POPS_ARGS (fndecl, TREE_TYPE (fndecl),
4911 current_function_args_size);
4913 /* For stdarg.h function, save info about
4914 regs and stack space used by the named args. */
4917 current_function_args_info = args_so_far;
4919 /* Set the rtx used for the function return value. Put this in its
4920 own variable so any optimizers that need this information don't have
4921 to include tree.h. Do this here so it gets done when an inlined
4922 function gets output. */
4924 current_function_return_rtx = DECL_RTL (DECL_RESULT (fndecl));
4927 /* Indicate whether REGNO is an incoming argument to the current function
4928 that was promoted to a wider mode. If so, return the RTX for the
4929 register (to get its mode). PMODE and PUNSIGNEDP are set to the mode
4930 that REGNO is promoted from and whether the promotion was signed or
4933 #ifdef PROMOTE_FUNCTION_ARGS
4936 promoted_input_arg (regno, pmode, punsignedp)
4938 enum machine_mode *pmode;
4943 for (arg = DECL_ARGUMENTS (current_function_decl); arg;
4944 arg = TREE_CHAIN (arg))
4945 if (GET_CODE (DECL_INCOMING_RTL (arg)) == REG
4946 && REGNO (DECL_INCOMING_RTL (arg)) == regno
4947 && TYPE_MODE (DECL_ARG_TYPE (arg)) == TYPE_MODE (TREE_TYPE (arg)))
4949 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg));
4950 int unsignedp = TREE_UNSIGNED (TREE_TYPE (arg));
4952 mode = promote_mode (TREE_TYPE (arg), mode, &unsignedp, 1);
4953 if (mode == GET_MODE (DECL_INCOMING_RTL (arg))
4954 && mode != DECL_MODE (arg))
4956 *pmode = DECL_MODE (arg);
4957 *punsignedp = unsignedp;
4958 return DECL_INCOMING_RTL (arg);
4967 /* Compute the size and offset from the start of the stacked arguments for a
4968 parm passed in mode PASSED_MODE and with type TYPE.
4970 INITIAL_OFFSET_PTR points to the current offset into the stacked
4973 The starting offset and size for this parm are returned in *OFFSET_PTR
4974 and *ARG_SIZE_PTR, respectively.
4976 IN_REGS is non-zero if the argument will be passed in registers. It will
4977 never be set if REG_PARM_STACK_SPACE is not defined.
4979 FNDECL is the function in which the argument was defined.
4981 There are two types of rounding that are done. The first, controlled by
4982 FUNCTION_ARG_BOUNDARY, forces the offset from the start of the argument
4983 list to be aligned to the specific boundary (in bits). This rounding
4984 affects the initial and starting offsets, but not the argument size.
4986 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
4987 optionally rounds the size of the parm to PARM_BOUNDARY. The
4988 initial offset is not affected by this rounding, while the size always
4989 is and the starting offset may be. */
4991 /* offset_ptr will be negative for ARGS_GROW_DOWNWARD case;
4992 initial_offset_ptr is positive because locate_and_pad_parm's
4993 callers pass in the total size of args so far as
4994 initial_offset_ptr. arg_size_ptr is always positive.*/
4997 locate_and_pad_parm (passed_mode, type, in_regs, fndecl,
4998 initial_offset_ptr, offset_ptr, arg_size_ptr,
5000 enum machine_mode passed_mode;
5002 int in_regs ATTRIBUTE_UNUSED;
5003 tree fndecl ATTRIBUTE_UNUSED;
5004 struct args_size *initial_offset_ptr;
5005 struct args_size *offset_ptr;
5006 struct args_size *arg_size_ptr;
5007 struct args_size *alignment_pad;
5011 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
5012 enum direction where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
5013 int boundary = FUNCTION_ARG_BOUNDARY (passed_mode, type);
5015 #ifdef REG_PARM_STACK_SPACE
5016 /* If we have found a stack parm before we reach the end of the
5017 area reserved for registers, skip that area. */
5020 int reg_parm_stack_space = 0;
5022 #ifdef MAYBE_REG_PARM_STACK_SPACE
5023 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
5025 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
5027 if (reg_parm_stack_space > 0)
5029 if (initial_offset_ptr->var)
5031 initial_offset_ptr->var
5032 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
5033 ssize_int (reg_parm_stack_space));
5034 initial_offset_ptr->constant = 0;
5036 else if (initial_offset_ptr->constant < reg_parm_stack_space)
5037 initial_offset_ptr->constant = reg_parm_stack_space;
5040 #endif /* REG_PARM_STACK_SPACE */
5042 arg_size_ptr->var = 0;
5043 arg_size_ptr->constant = 0;
5045 #ifdef ARGS_GROW_DOWNWARD
5046 if (initial_offset_ptr->var)
5048 offset_ptr->constant = 0;
5049 offset_ptr->var = size_binop (MINUS_EXPR, ssize_int (0),
5050 initial_offset_ptr->var);
5054 offset_ptr->constant = -initial_offset_ptr->constant;
5055 offset_ptr->var = 0;
5057 if (where_pad != none
5058 && (TREE_CODE (sizetree) != INTEGER_CST
5059 || ((TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)))
5060 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
5061 SUB_PARM_SIZE (*offset_ptr, sizetree);
5062 if (where_pad != downward)
5063 pad_to_arg_alignment (offset_ptr, boundary, alignment_pad);
5064 if (initial_offset_ptr->var)
5065 arg_size_ptr->var = size_binop (MINUS_EXPR,
5066 size_binop (MINUS_EXPR,
5068 initial_offset_ptr->var),
5072 arg_size_ptr->constant = (-initial_offset_ptr->constant
5073 - offset_ptr->constant);
5075 #else /* !ARGS_GROW_DOWNWARD */
5076 pad_to_arg_alignment (initial_offset_ptr, boundary, alignment_pad);
5077 *offset_ptr = *initial_offset_ptr;
5079 #ifdef PUSH_ROUNDING
5080 if (passed_mode != BLKmode)
5081 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
5084 /* Pad_below needs the pre-rounded size to know how much to pad below
5085 so this must be done before rounding up. */
5086 if (where_pad == downward
5087 /* However, BLKmode args passed in regs have their padding done elsewhere.
5088 The stack slot must be able to hold the entire register. */
5089 && !(in_regs && passed_mode == BLKmode))
5090 pad_below (offset_ptr, passed_mode, sizetree);
5092 if (where_pad != none
5093 && (TREE_CODE (sizetree) != INTEGER_CST
5094 || ((TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)))
5095 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
5097 ADD_PARM_SIZE (*arg_size_ptr, sizetree);
5098 #endif /* ARGS_GROW_DOWNWARD */
5101 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
5102 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
5105 pad_to_arg_alignment (offset_ptr, boundary, alignment_pad)
5106 struct args_size *offset_ptr;
5108 struct args_size *alignment_pad;
5110 tree save_var = NULL_TREE;
5111 HOST_WIDE_INT save_constant = 0;
5113 int boundary_in_bytes = boundary / BITS_PER_UNIT;
5115 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
5117 save_var = offset_ptr->var;
5118 save_constant = offset_ptr->constant;
5121 alignment_pad->var = NULL_TREE;
5122 alignment_pad->constant = 0;
5124 if (boundary > BITS_PER_UNIT)
5126 if (offset_ptr->var)
5129 #ifdef ARGS_GROW_DOWNWARD
5134 (ARGS_SIZE_TREE (*offset_ptr),
5135 boundary / BITS_PER_UNIT);
5136 offset_ptr->constant = 0; /*?*/
5137 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
5138 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
5143 offset_ptr->constant =
5144 #ifdef ARGS_GROW_DOWNWARD
5145 FLOOR_ROUND (offset_ptr->constant, boundary_in_bytes);
5147 CEIL_ROUND (offset_ptr->constant, boundary_in_bytes);
5149 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
5150 alignment_pad->constant = offset_ptr->constant - save_constant;
5155 #ifndef ARGS_GROW_DOWNWARD
5157 pad_below (offset_ptr, passed_mode, sizetree)
5158 struct args_size *offset_ptr;
5159 enum machine_mode passed_mode;
5162 if (passed_mode != BLKmode)
5164 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
5165 offset_ptr->constant
5166 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
5167 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
5168 - GET_MODE_SIZE (passed_mode));
5172 if (TREE_CODE (sizetree) != INTEGER_CST
5173 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
5175 /* Round the size up to multiple of PARM_BOUNDARY bits. */
5176 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
5178 ADD_PARM_SIZE (*offset_ptr, s2);
5179 SUB_PARM_SIZE (*offset_ptr, sizetree);
5185 /* Walk the tree of blocks describing the binding levels within a function
5186 and warn about uninitialized variables.
5187 This is done after calling flow_analysis and before global_alloc
5188 clobbers the pseudo-regs to hard regs. */
5191 uninitialized_vars_warning (block)
5194 register tree decl, sub;
5195 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
5197 if (warn_uninitialized
5198 && TREE_CODE (decl) == VAR_DECL
5199 /* These warnings are unreliable for and aggregates
5200 because assigning the fields one by one can fail to convince
5201 flow.c that the entire aggregate was initialized.
5202 Unions are troublesome because members may be shorter. */
5203 && ! AGGREGATE_TYPE_P (TREE_TYPE (decl))
5204 && DECL_RTL (decl) != 0
5205 && GET_CODE (DECL_RTL (decl)) == REG
5206 /* Global optimizations can make it difficult to determine if a
5207 particular variable has been initialized. However, a VAR_DECL
5208 with a nonzero DECL_INITIAL had an initializer, so do not
5209 claim it is potentially uninitialized.
5211 We do not care about the actual value in DECL_INITIAL, so we do
5212 not worry that it may be a dangling pointer. */
5213 && DECL_INITIAL (decl) == NULL_TREE
5214 && regno_uninitialized (REGNO (DECL_RTL (decl))))
5215 warning_with_decl (decl,
5216 "`%s' might be used uninitialized in this function");
5218 && TREE_CODE (decl) == VAR_DECL
5219 && DECL_RTL (decl) != 0
5220 && GET_CODE (DECL_RTL (decl)) == REG
5221 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
5222 warning_with_decl (decl,
5223 "variable `%s' might be clobbered by `longjmp' or `vfork'");
5225 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
5226 uninitialized_vars_warning (sub);
5229 /* Do the appropriate part of uninitialized_vars_warning
5230 but for arguments instead of local variables. */
5233 setjmp_args_warning ()
5236 for (decl = DECL_ARGUMENTS (current_function_decl);
5237 decl; decl = TREE_CHAIN (decl))
5238 if (DECL_RTL (decl) != 0
5239 && GET_CODE (DECL_RTL (decl)) == REG
5240 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
5241 warning_with_decl (decl,
5242 "argument `%s' might be clobbered by `longjmp' or `vfork'");
5245 /* If this function call setjmp, put all vars into the stack
5246 unless they were declared `register'. */
5249 setjmp_protect (block)
5252 register tree decl, sub;
5253 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
5254 if ((TREE_CODE (decl) == VAR_DECL
5255 || TREE_CODE (decl) == PARM_DECL)
5256 && DECL_RTL (decl) != 0
5257 && (GET_CODE (DECL_RTL (decl)) == REG
5258 || (GET_CODE (DECL_RTL (decl)) == MEM
5259 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == ADDRESSOF))
5260 /* If this variable came from an inline function, it must be
5261 that its life doesn't overlap the setjmp. If there was a
5262 setjmp in the function, it would already be in memory. We
5263 must exclude such variable because their DECL_RTL might be
5264 set to strange things such as virtual_stack_vars_rtx. */
5265 && ! DECL_FROM_INLINE (decl)
5267 #ifdef NON_SAVING_SETJMP
5268 /* If longjmp doesn't restore the registers,
5269 don't put anything in them. */
5273 ! DECL_REGISTER (decl)))
5274 put_var_into_stack (decl);
5275 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
5276 setjmp_protect (sub);
5279 /* Like the previous function, but for args instead of local variables. */
5282 setjmp_protect_args ()
5285 for (decl = DECL_ARGUMENTS (current_function_decl);
5286 decl; decl = TREE_CHAIN (decl))
5287 if ((TREE_CODE (decl) == VAR_DECL
5288 || TREE_CODE (decl) == PARM_DECL)
5289 && DECL_RTL (decl) != 0
5290 && (GET_CODE (DECL_RTL (decl)) == REG
5291 || (GET_CODE (DECL_RTL (decl)) == MEM
5292 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == ADDRESSOF))
5294 /* If longjmp doesn't restore the registers,
5295 don't put anything in them. */
5296 #ifdef NON_SAVING_SETJMP
5300 ! DECL_REGISTER (decl)))
5301 put_var_into_stack (decl);
5304 /* Return the context-pointer register corresponding to DECL,
5305 or 0 if it does not need one. */
5308 lookup_static_chain (decl)
5311 tree context = decl_function_context (decl);
5315 || (TREE_CODE (decl) == FUNCTION_DECL && DECL_NO_STATIC_CHAIN (decl)))
5318 /* We treat inline_function_decl as an alias for the current function
5319 because that is the inline function whose vars, types, etc.
5320 are being merged into the current function.
5321 See expand_inline_function. */
5322 if (context == current_function_decl || context == inline_function_decl)
5323 return virtual_stack_vars_rtx;
5325 for (link = context_display; link; link = TREE_CHAIN (link))
5326 if (TREE_PURPOSE (link) == context)
5327 return RTL_EXPR_RTL (TREE_VALUE (link));
5332 /* Convert a stack slot address ADDR for variable VAR
5333 (from a containing function)
5334 into an address valid in this function (using a static chain). */
5337 fix_lexical_addr (addr, var)
5342 HOST_WIDE_INT displacement;
5343 tree context = decl_function_context (var);
5344 struct function *fp;
5347 /* If this is the present function, we need not do anything. */
5348 if (context == current_function_decl || context == inline_function_decl)
5351 for (fp = outer_function_chain; fp; fp = fp->next)
5352 if (fp->decl == context)
5358 if (GET_CODE (addr) == ADDRESSOF && GET_CODE (XEXP (addr, 0)) == MEM)
5359 addr = XEXP (XEXP (addr, 0), 0);
5361 /* Decode given address as base reg plus displacement. */
5362 if (GET_CODE (addr) == REG)
5363 basereg = addr, displacement = 0;
5364 else if (GET_CODE (addr) == PLUS && GET_CODE (XEXP (addr, 1)) == CONST_INT)
5365 basereg = XEXP (addr, 0), displacement = INTVAL (XEXP (addr, 1));
5369 /* We accept vars reached via the containing function's
5370 incoming arg pointer and via its stack variables pointer. */
5371 if (basereg == fp->internal_arg_pointer)
5373 /* If reached via arg pointer, get the arg pointer value
5374 out of that function's stack frame.
5376 There are two cases: If a separate ap is needed, allocate a
5377 slot in the outer function for it and dereference it that way.
5378 This is correct even if the real ap is actually a pseudo.
5379 Otherwise, just adjust the offset from the frame pointer to
5382 #ifdef NEED_SEPARATE_AP
5385 if (fp->x_arg_pointer_save_area == 0)
5386 fp->x_arg_pointer_save_area
5387 = assign_stack_local_1 (Pmode, GET_MODE_SIZE (Pmode), 0, fp);
5389 addr = fix_lexical_addr (XEXP (fp->x_arg_pointer_save_area, 0), var);
5390 addr = memory_address (Pmode, addr);
5392 base = gen_rtx_MEM (Pmode, addr);
5393 MEM_ALIAS_SET (base) = get_frame_alias_set ();
5394 base = copy_to_reg (base);
5396 displacement += (FIRST_PARM_OFFSET (context) - STARTING_FRAME_OFFSET);
5397 base = lookup_static_chain (var);
5401 else if (basereg == virtual_stack_vars_rtx)
5403 /* This is the same code as lookup_static_chain, duplicated here to
5404 avoid an extra call to decl_function_context. */
5407 for (link = context_display; link; link = TREE_CHAIN (link))
5408 if (TREE_PURPOSE (link) == context)
5410 base = RTL_EXPR_RTL (TREE_VALUE (link));
5418 /* Use same offset, relative to appropriate static chain or argument
5420 return plus_constant (base, displacement);
5423 /* Return the address of the trampoline for entering nested fn FUNCTION.
5424 If necessary, allocate a trampoline (in the stack frame)
5425 and emit rtl to initialize its contents (at entry to this function). */
5428 trampoline_address (function)
5434 struct function *fp;
5437 /* Find an existing trampoline and return it. */
5438 for (link = trampoline_list; link; link = TREE_CHAIN (link))
5439 if (TREE_PURPOSE (link) == function)
5441 round_trampoline_addr (XEXP (RTL_EXPR_RTL (TREE_VALUE (link)), 0));
5443 for (fp = outer_function_chain; fp; fp = fp->next)
5444 for (link = fp->x_trampoline_list; link; link = TREE_CHAIN (link))
5445 if (TREE_PURPOSE (link) == function)
5447 tramp = fix_lexical_addr (XEXP (RTL_EXPR_RTL (TREE_VALUE (link)), 0),
5449 return round_trampoline_addr (tramp);
5452 /* None exists; we must make one. */
5454 /* Find the `struct function' for the function containing FUNCTION. */
5456 fn_context = decl_function_context (function);
5457 if (fn_context != current_function_decl
5458 && fn_context != inline_function_decl)
5459 for (fp = outer_function_chain; fp; fp = fp->next)
5460 if (fp->decl == fn_context)
5463 /* Allocate run-time space for this trampoline
5464 (usually in the defining function's stack frame). */
5465 #ifdef ALLOCATE_TRAMPOLINE
5466 tramp = ALLOCATE_TRAMPOLINE (fp);
5468 /* If rounding needed, allocate extra space
5469 to ensure we have TRAMPOLINE_SIZE bytes left after rounding up. */
5470 #ifdef TRAMPOLINE_ALIGNMENT
5471 #define TRAMPOLINE_REAL_SIZE \
5472 (TRAMPOLINE_SIZE + (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT) - 1)
5474 #define TRAMPOLINE_REAL_SIZE (TRAMPOLINE_SIZE)
5476 tramp = assign_stack_local_1 (BLKmode, TRAMPOLINE_REAL_SIZE, 0,
5480 /* Record the trampoline for reuse and note it for later initialization
5481 by expand_function_end. */
5484 push_obstacks (fp->function_maybepermanent_obstack,
5485 fp->function_maybepermanent_obstack);
5486 rtlexp = make_node (RTL_EXPR);
5487 RTL_EXPR_RTL (rtlexp) = tramp;
5488 fp->x_trampoline_list = tree_cons (function, rtlexp,
5489 fp->x_trampoline_list);
5494 /* Make the RTL_EXPR node temporary, not momentary, so that the
5495 trampoline_list doesn't become garbage. */
5496 int momentary = suspend_momentary ();
5497 rtlexp = make_node (RTL_EXPR);
5498 resume_momentary (momentary);
5500 RTL_EXPR_RTL (rtlexp) = tramp;
5501 trampoline_list = tree_cons (function, rtlexp, trampoline_list);
5504 tramp = fix_lexical_addr (XEXP (tramp, 0), function);
5505 return round_trampoline_addr (tramp);
5508 /* Given a trampoline address,
5509 round it to multiple of TRAMPOLINE_ALIGNMENT. */
5512 round_trampoline_addr (tramp)
5515 #ifdef TRAMPOLINE_ALIGNMENT
5516 /* Round address up to desired boundary. */
5517 rtx temp = gen_reg_rtx (Pmode);
5518 temp = expand_binop (Pmode, add_optab, tramp,
5519 GEN_INT (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT - 1),
5520 temp, 0, OPTAB_LIB_WIDEN);
5521 tramp = expand_binop (Pmode, and_optab, temp,
5522 GEN_INT (-TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT),
5523 temp, 0, OPTAB_LIB_WIDEN);
5528 /* Put all this function's BLOCK nodes including those that are chained
5529 onto the first block into a vector, and return it.
5530 Also store in each NOTE for the beginning or end of a block
5531 the index of that block in the vector.
5532 The arguments are BLOCK, the chain of top-level blocks of the function,
5533 and INSNS, the insn chain of the function. */
5539 tree *block_vector, *last_block_vector;
5541 tree block = DECL_INITIAL (current_function_decl);
5546 /* Fill the BLOCK_VECTOR with all of the BLOCKs in this function, in
5547 depth-first order. */
5548 block_vector = get_block_vector (block, &n_blocks);
5549 block_stack = (tree *) xmalloc (n_blocks * sizeof (tree));
5551 last_block_vector = identify_blocks_1 (get_insns (),
5553 block_vector + n_blocks,
5556 /* If we didn't use all of the subblocks, we've misplaced block notes. */
5557 /* ??? This appears to happen all the time. Latent bugs elsewhere? */
5558 if (0 && last_block_vector != block_vector + n_blocks)
5561 free (block_vector);
5565 /* Subroutine of identify_blocks. Do the block substitution on the
5566 insn chain beginning with INSNS. Recurse for CALL_PLACEHOLDER chains.
5568 BLOCK_STACK is pushed and popped for each BLOCK_BEGIN/BLOCK_END pair.
5569 BLOCK_VECTOR is incremented for each block seen. */
5572 identify_blocks_1 (insns, block_vector, end_block_vector, orig_block_stack)
5575 tree *end_block_vector;
5576 tree *orig_block_stack;
5579 tree *block_stack = orig_block_stack;
5581 for (insn = insns; insn; insn = NEXT_INSN (insn))
5583 if (GET_CODE (insn) == NOTE)
5585 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
5589 /* If there are more block notes than BLOCKs, something
5591 if (block_vector == end_block_vector)
5594 b = *block_vector++;
5595 NOTE_BLOCK (insn) = b;
5598 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
5600 /* If there are more NOTE_INSN_BLOCK_ENDs than
5601 NOTE_INSN_BLOCK_BEGs, something is badly wrong. */
5602 if (block_stack == orig_block_stack)
5605 NOTE_BLOCK (insn) = *--block_stack;
5608 else if (GET_CODE (insn) == CALL_INSN
5609 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
5611 rtx cp = PATTERN (insn);
5613 block_vector = identify_blocks_1 (XEXP (cp, 0), block_vector,
5614 end_block_vector, block_stack);
5616 block_vector = identify_blocks_1 (XEXP (cp, 1), block_vector,
5617 end_block_vector, block_stack);
5619 block_vector = identify_blocks_1 (XEXP (cp, 2), block_vector,
5620 end_block_vector, block_stack);
5624 /* If there are more NOTE_INSN_BLOCK_BEGINs than NOTE_INSN_BLOCK_ENDs,
5625 something is badly wrong. */
5626 if (block_stack != orig_block_stack)
5629 return block_vector;
5632 /* Identify BLOCKs referenced by more than one
5633 NOTE_INSN_BLOCK_{BEG,END}, and create duplicate blocks. */
5638 tree block = DECL_INITIAL (current_function_decl);
5639 varray_type block_stack;
5641 if (block == NULL_TREE)
5644 VARRAY_TREE_INIT (block_stack, 10, "block_stack");
5646 /* Prune the old trees away, so that they don't get in the way. */
5647 BLOCK_SUBBLOCKS (block) = NULL_TREE;
5648 BLOCK_CHAIN (block) = NULL_TREE;
5650 reorder_blocks_1 (get_insns (), block, &block_stack);
5652 BLOCK_SUBBLOCKS (block) = blocks_nreverse (BLOCK_SUBBLOCKS (block));
5654 VARRAY_FREE (block_stack);
5657 /* Helper function for reorder_blocks. Process the insn chain beginning
5658 at INSNS. Recurse for CALL_PLACEHOLDER insns. */
5661 reorder_blocks_1 (insns, current_block, p_block_stack)
5664 varray_type *p_block_stack;
5668 for (insn = insns; insn; insn = NEXT_INSN (insn))
5670 if (GET_CODE (insn) == NOTE)
5672 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
5674 tree block = NOTE_BLOCK (insn);
5675 /* If we have seen this block before, copy it. */
5676 if (TREE_ASM_WRITTEN (block))
5678 block = copy_node (block);
5679 NOTE_BLOCK (insn) = block;
5681 BLOCK_SUBBLOCKS (block) = 0;
5682 TREE_ASM_WRITTEN (block) = 1;
5683 BLOCK_SUPERCONTEXT (block) = current_block;
5684 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
5685 BLOCK_SUBBLOCKS (current_block) = block;
5686 current_block = block;
5687 VARRAY_PUSH_TREE (*p_block_stack, block);
5689 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
5691 NOTE_BLOCK (insn) = VARRAY_TOP_TREE (*p_block_stack);
5692 VARRAY_POP (*p_block_stack);
5693 BLOCK_SUBBLOCKS (current_block)
5694 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block));
5695 current_block = BLOCK_SUPERCONTEXT (current_block);
5698 else if (GET_CODE (insn) == CALL_INSN
5699 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
5701 rtx cp = PATTERN (insn);
5702 reorder_blocks_1 (XEXP (cp, 0), current_block, p_block_stack);
5704 reorder_blocks_1 (XEXP (cp, 1), current_block, p_block_stack);
5706 reorder_blocks_1 (XEXP (cp, 2), current_block, p_block_stack);
5711 /* Reverse the order of elements in the chain T of blocks,
5712 and return the new head of the chain (old last element). */
5718 register tree prev = 0, decl, next;
5719 for (decl = t; decl; decl = next)
5721 next = BLOCK_CHAIN (decl);
5722 BLOCK_CHAIN (decl) = prev;
5728 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
5729 non-NULL, list them all into VECTOR, in a depth-first preorder
5730 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
5734 all_blocks (block, vector)
5742 TREE_ASM_WRITTEN (block) = 0;
5744 /* Record this block. */
5746 vector[n_blocks] = block;
5750 /* Record the subblocks, and their subblocks... */
5751 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
5752 vector ? vector + n_blocks : 0);
5753 block = BLOCK_CHAIN (block);
5759 /* Return a vector containing all the blocks rooted at BLOCK. The
5760 number of elements in the vector is stored in N_BLOCKS_P. The
5761 vector is dynamically allocated; it is the caller's responsibility
5762 to call `free' on the pointer returned. */
5765 get_block_vector (block, n_blocks_p)
5771 *n_blocks_p = all_blocks (block, NULL);
5772 block_vector = (tree *) xmalloc (*n_blocks_p * sizeof (tree));
5773 all_blocks (block, block_vector);
5775 return block_vector;
5778 static int next_block_index = 2;
5780 /* Set BLOCK_NUMBER for all the blocks in FN. */
5790 /* For SDB and XCOFF debugging output, we start numbering the blocks
5791 from 1 within each function, rather than keeping a running
5793 #if defined (SDB_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
5794 if (write_symbols == SDB_DEBUG || write_symbols == XCOFF_DEBUG)
5795 next_block_index = 1;
5798 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
5800 /* The top-level BLOCK isn't numbered at all. */
5801 for (i = 1; i < n_blocks; ++i)
5802 /* We number the blocks from two. */
5803 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
5805 free (block_vector);
5810 /* Allocate a function structure and reset its contents to the defaults. */
5812 prepare_function_start ()
5814 cfun = (struct function *) xcalloc (1, sizeof (struct function));
5816 init_stmt_for_function ();
5817 init_eh_for_function ();
5819 cse_not_expected = ! optimize;
5821 /* Caller save not needed yet. */
5822 caller_save_needed = 0;
5824 /* No stack slots have been made yet. */
5825 stack_slot_list = 0;
5827 current_function_has_nonlocal_label = 0;
5828 current_function_has_nonlocal_goto = 0;
5830 /* There is no stack slot for handling nonlocal gotos. */
5831 nonlocal_goto_handler_slots = 0;
5832 nonlocal_goto_stack_level = 0;
5834 /* No labels have been declared for nonlocal use. */
5835 nonlocal_labels = 0;
5836 nonlocal_goto_handler_labels = 0;
5838 /* No function calls so far in this function. */
5839 function_call_count = 0;
5841 /* No parm regs have been allocated.
5842 (This is important for output_inline_function.) */
5843 max_parm_reg = LAST_VIRTUAL_REGISTER + 1;
5845 /* Initialize the RTL mechanism. */
5848 /* Initialize the queue of pending postincrement and postdecrements,
5849 and some other info in expr.c. */
5852 /* We haven't done register allocation yet. */
5855 init_varasm_status (cfun);
5857 /* Clear out data used for inlining. */
5858 cfun->inlinable = 0;
5859 cfun->original_decl_initial = 0;
5860 cfun->original_arg_vector = 0;
5862 #ifdef STACK_BOUNDARY
5863 cfun->stack_alignment_needed = STACK_BOUNDARY;
5864 cfun->preferred_stack_boundary = STACK_BOUNDARY;
5866 cfun->stack_alignment_needed = 0;
5867 cfun->preferred_stack_boundary = 0;
5870 /* Set if a call to setjmp is seen. */
5871 current_function_calls_setjmp = 0;
5873 /* Set if a call to longjmp is seen. */
5874 current_function_calls_longjmp = 0;
5876 current_function_calls_alloca = 0;
5877 current_function_contains_functions = 0;
5878 current_function_is_leaf = 0;
5879 current_function_nothrow = 0;
5880 current_function_sp_is_unchanging = 0;
5881 current_function_uses_only_leaf_regs = 0;
5882 current_function_has_computed_jump = 0;
5883 current_function_is_thunk = 0;
5885 current_function_returns_pcc_struct = 0;
5886 current_function_returns_struct = 0;
5887 current_function_epilogue_delay_list = 0;
5888 current_function_uses_const_pool = 0;
5889 current_function_uses_pic_offset_table = 0;
5890 current_function_cannot_inline = 0;
5892 /* We have not yet needed to make a label to jump to for tail-recursion. */
5893 tail_recursion_label = 0;
5895 /* We haven't had a need to make a save area for ap yet. */
5896 arg_pointer_save_area = 0;
5898 /* No stack slots allocated yet. */
5901 /* No SAVE_EXPRs in this function yet. */
5904 /* No RTL_EXPRs in this function yet. */
5907 /* Set up to allocate temporaries. */
5910 /* Indicate that we need to distinguish between the return value of the
5911 present function and the return value of a function being called. */
5912 rtx_equal_function_value_matters = 1;
5914 /* Indicate that we have not instantiated virtual registers yet. */
5915 virtuals_instantiated = 0;
5917 /* Indicate we have no need of a frame pointer yet. */
5918 frame_pointer_needed = 0;
5920 /* By default assume not varargs or stdarg. */
5921 current_function_varargs = 0;
5922 current_function_stdarg = 0;
5924 /* We haven't made any trampolines for this function yet. */
5925 trampoline_list = 0;
5927 init_pending_stack_adjust ();
5928 inhibit_defer_pop = 0;
5930 current_function_outgoing_args_size = 0;
5932 if (init_lang_status)
5933 (*init_lang_status) (cfun);
5934 if (init_machine_status)
5935 (*init_machine_status) (cfun);
5938 /* Initialize the rtl expansion mechanism so that we can do simple things
5939 like generate sequences. This is used to provide a context during global
5940 initialization of some passes. */
5942 init_dummy_function_start ()
5944 prepare_function_start ();
5947 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
5948 and initialize static variables for generating RTL for the statements
5952 init_function_start (subr, filename, line)
5954 const char *filename;
5957 prepare_function_start ();
5959 /* Remember this function for later. */
5960 cfun->next_global = all_functions;
5961 all_functions = cfun;
5963 current_function_name = (*decl_printable_name) (subr, 2);
5966 /* Nonzero if this is a nested function that uses a static chain. */
5968 current_function_needs_context
5969 = (decl_function_context (current_function_decl) != 0
5970 && ! DECL_NO_STATIC_CHAIN (current_function_decl));
5972 /* Within function body, compute a type's size as soon it is laid out. */
5973 immediate_size_expand++;
5975 /* Prevent ever trying to delete the first instruction of a function.
5976 Also tell final how to output a linenum before the function prologue.
5977 Note linenums could be missing, e.g. when compiling a Java .class file. */
5979 emit_line_note (filename, line);
5981 /* Make sure first insn is a note even if we don't want linenums.
5982 This makes sure the first insn will never be deleted.
5983 Also, final expects a note to appear there. */
5984 emit_note (NULL_PTR, NOTE_INSN_DELETED);
5986 /* Set flags used by final.c. */
5987 if (aggregate_value_p (DECL_RESULT (subr)))
5989 #ifdef PCC_STATIC_STRUCT_RETURN
5990 current_function_returns_pcc_struct = 1;
5992 current_function_returns_struct = 1;
5995 /* Warn if this value is an aggregate type,
5996 regardless of which calling convention we are using for it. */
5997 if (warn_aggregate_return
5998 && AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
5999 warning ("function returns an aggregate");
6001 current_function_returns_pointer
6002 = POINTER_TYPE_P (TREE_TYPE (DECL_RESULT (subr)));
6005 /* Make sure all values used by the optimization passes have sane
6008 init_function_for_compilation ()
6012 /* No prologue/epilogue insns yet. */
6013 VARRAY_GROW (prologue, 0);
6014 VARRAY_GROW (epilogue, 0);
6015 VARRAY_GROW (sibcall_epilogue, 0);
6018 /* Indicate that the current function uses extra args
6019 not explicitly mentioned in the argument list in any fashion. */
6024 current_function_varargs = 1;
6027 /* Expand a call to __main at the beginning of a possible main function. */
6029 #if defined(INIT_SECTION_ASM_OP) && !defined(INVOKE__main)
6030 #undef HAS_INIT_SECTION
6031 #define HAS_INIT_SECTION
6035 expand_main_function ()
6037 #if !defined (HAS_INIT_SECTION)
6038 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, NAME__MAIN), 0,
6040 #endif /* not HAS_INIT_SECTION */
6043 extern struct obstack permanent_obstack;
6045 /* Start the RTL for a new function, and set variables used for
6047 SUBR is the FUNCTION_DECL node.
6048 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
6049 the function's parameters, which must be run at any return statement. */
6052 expand_function_start (subr, parms_have_cleanups)
6054 int parms_have_cleanups;
6057 rtx last_ptr = NULL_RTX;
6059 /* Make sure volatile mem refs aren't considered
6060 valid operands of arithmetic insns. */
6061 init_recog_no_volatile ();
6063 /* Set this before generating any memory accesses. */
6064 current_function_check_memory_usage
6065 = (flag_check_memory_usage
6066 && ! DECL_NO_CHECK_MEMORY_USAGE (current_function_decl));
6068 current_function_instrument_entry_exit
6069 = (flag_instrument_function_entry_exit
6070 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
6072 current_function_limit_stack
6073 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
6075 /* If function gets a static chain arg, store it in the stack frame.
6076 Do this first, so it gets the first stack slot offset. */
6077 if (current_function_needs_context)
6079 last_ptr = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
6081 /* Delay copying static chain if it is not a register to avoid
6082 conflicts with regs used for parameters. */
6083 if (! SMALL_REGISTER_CLASSES
6084 || GET_CODE (static_chain_incoming_rtx) == REG)
6085 emit_move_insn (last_ptr, static_chain_incoming_rtx);
6088 /* If the parameters of this function need cleaning up, get a label
6089 for the beginning of the code which executes those cleanups. This must
6090 be done before doing anything with return_label. */
6091 if (parms_have_cleanups)
6092 cleanup_label = gen_label_rtx ();
6096 /* Make the label for return statements to jump to, if this machine
6097 does not have a one-instruction return and uses an epilogue,
6098 or if it returns a structure, or if it has parm cleanups. */
6100 if (cleanup_label == 0 && HAVE_return
6101 && ! current_function_instrument_entry_exit
6102 && ! current_function_returns_pcc_struct
6103 && ! (current_function_returns_struct && ! optimize))
6106 return_label = gen_label_rtx ();
6108 return_label = gen_label_rtx ();
6111 /* Initialize rtx used to return the value. */
6112 /* Do this before assign_parms so that we copy the struct value address
6113 before any library calls that assign parms might generate. */
6115 /* Decide whether to return the value in memory or in a register. */
6116 if (aggregate_value_p (DECL_RESULT (subr)))
6118 /* Returning something that won't go in a register. */
6119 register rtx value_address = 0;
6121 #ifdef PCC_STATIC_STRUCT_RETURN
6122 if (current_function_returns_pcc_struct)
6124 int size = int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr)));
6125 value_address = assemble_static_space (size);
6130 /* Expect to be passed the address of a place to store the value.
6131 If it is passed as an argument, assign_parms will take care of
6133 if (struct_value_incoming_rtx)
6135 value_address = gen_reg_rtx (Pmode);
6136 emit_move_insn (value_address, struct_value_incoming_rtx);
6141 DECL_RTL (DECL_RESULT (subr))
6142 = gen_rtx_MEM (DECL_MODE (DECL_RESULT (subr)), value_address);
6143 set_mem_attributes (DECL_RTL (DECL_RESULT (subr)),
6144 DECL_RESULT (subr), 1);
6147 else if (DECL_MODE (DECL_RESULT (subr)) == VOIDmode)
6148 /* If return mode is void, this decl rtl should not be used. */
6149 DECL_RTL (DECL_RESULT (subr)) = 0;
6150 else if (parms_have_cleanups || current_function_instrument_entry_exit)
6152 /* If function will end with cleanup code for parms,
6153 compute the return values into a pseudo reg,
6154 which we will copy into the true return register
6155 after the cleanups are done. */
6157 enum machine_mode mode = DECL_MODE (DECL_RESULT (subr));
6159 #ifdef PROMOTE_FUNCTION_RETURN
6160 tree type = TREE_TYPE (DECL_RESULT (subr));
6161 int unsignedp = TREE_UNSIGNED (type);
6163 mode = promote_mode (type, mode, &unsignedp, 1);
6166 DECL_RTL (DECL_RESULT (subr)) = gen_reg_rtx (mode);
6169 /* Scalar, returned in a register. */
6171 DECL_RTL (DECL_RESULT (subr))
6172 = hard_function_value (TREE_TYPE (DECL_RESULT (subr)), subr, 1);
6174 /* Mark this reg as the function's return value. */
6175 if (GET_CODE (DECL_RTL (DECL_RESULT (subr))) == REG)
6177 REG_FUNCTION_VALUE_P (DECL_RTL (DECL_RESULT (subr))) = 1;
6178 /* Needed because we may need to move this to memory
6179 in case it's a named return value whose address is taken. */
6180 DECL_REGISTER (DECL_RESULT (subr)) = 1;
6184 /* Initialize rtx for parameters and local variables.
6185 In some cases this requires emitting insns. */
6187 assign_parms (subr);
6189 /* Copy the static chain now if it wasn't a register. The delay is to
6190 avoid conflicts with the parameter passing registers. */
6192 if (SMALL_REGISTER_CLASSES && current_function_needs_context)
6193 if (GET_CODE (static_chain_incoming_rtx) != REG)
6194 emit_move_insn (last_ptr, static_chain_incoming_rtx);
6196 /* The following was moved from init_function_start.
6197 The move is supposed to make sdb output more accurate. */
6198 /* Indicate the beginning of the function body,
6199 as opposed to parm setup. */
6200 emit_note (NULL_PTR, NOTE_INSN_FUNCTION_BEG);
6202 if (GET_CODE (get_last_insn ()) != NOTE)
6203 emit_note (NULL_PTR, NOTE_INSN_DELETED);
6204 parm_birth_insn = get_last_insn ();
6206 context_display = 0;
6207 if (current_function_needs_context)
6209 /* Fetch static chain values for containing functions. */
6210 tem = decl_function_context (current_function_decl);
6211 /* Copy the static chain pointer into a pseudo. If we have
6212 small register classes, copy the value from memory if
6213 static_chain_incoming_rtx is a REG. */
6216 /* If the static chain originally came in a register, put it back
6217 there, then move it out in the next insn. The reason for
6218 this peculiar code is to satisfy function integration. */
6219 if (SMALL_REGISTER_CLASSES
6220 && GET_CODE (static_chain_incoming_rtx) == REG)
6221 emit_move_insn (static_chain_incoming_rtx, last_ptr);
6222 last_ptr = copy_to_reg (static_chain_incoming_rtx);
6227 tree rtlexp = make_node (RTL_EXPR);
6229 RTL_EXPR_RTL (rtlexp) = last_ptr;
6230 context_display = tree_cons (tem, rtlexp, context_display);
6231 tem = decl_function_context (tem);
6234 /* Chain thru stack frames, assuming pointer to next lexical frame
6235 is found at the place we always store it. */
6236 #ifdef FRAME_GROWS_DOWNWARD
6237 last_ptr = plus_constant (last_ptr, -GET_MODE_SIZE (Pmode));
6239 last_ptr = gen_rtx_MEM (Pmode, memory_address (Pmode, last_ptr));
6240 MEM_ALIAS_SET (last_ptr) = get_frame_alias_set ();
6241 last_ptr = copy_to_reg (last_ptr);
6243 /* If we are not optimizing, ensure that we know that this
6244 piece of context is live over the entire function. */
6246 save_expr_regs = gen_rtx_EXPR_LIST (VOIDmode, last_ptr,
6251 if (current_function_instrument_entry_exit)
6253 rtx fun = DECL_RTL (current_function_decl);
6254 if (GET_CODE (fun) == MEM)
6255 fun = XEXP (fun, 0);
6258 emit_library_call (profile_function_entry_libfunc, 0, VOIDmode, 2,
6260 expand_builtin_return_addr (BUILT_IN_RETURN_ADDRESS,
6262 hard_frame_pointer_rtx),
6266 /* After the display initializations is where the tail-recursion label
6267 should go, if we end up needing one. Ensure we have a NOTE here
6268 since some things (like trampolines) get placed before this. */
6269 tail_recursion_reentry = emit_note (NULL_PTR, NOTE_INSN_DELETED);
6271 /* Evaluate now the sizes of any types declared among the arguments. */
6272 for (tem = nreverse (get_pending_sizes ()); tem; tem = TREE_CHAIN (tem))
6274 expand_expr (TREE_VALUE (tem), const0_rtx, VOIDmode,
6275 EXPAND_MEMORY_USE_BAD);
6276 /* Flush the queue in case this parameter declaration has
6281 /* Make sure there is a line number after the function entry setup code. */
6282 force_next_line_note ();
6285 /* Undo the effects of init_dummy_function_start. */
6287 expand_dummy_function_end ()
6289 /* End any sequences that failed to be closed due to syntax errors. */
6290 while (in_sequence_p ())
6293 /* Outside function body, can't compute type's actual size
6294 until next function's body starts. */
6296 free_after_parsing (cfun);
6297 free_after_compilation (cfun);
6302 /* Call DOIT for each hard register used as a return value from
6303 the current function. */
6306 diddle_return_value (doit, arg)
6307 void (*doit) PARAMS ((rtx, void *));
6310 rtx outgoing = current_function_return_rtx;
6316 pcc = (current_function_returns_struct
6317 || current_function_returns_pcc_struct);
6319 if ((GET_CODE (outgoing) == REG
6320 && REGNO (outgoing) >= FIRST_PSEUDO_REGISTER)
6323 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
6325 /* A PCC-style return returns a pointer to the memory in which
6326 the structure is stored. */
6328 type = build_pointer_type (type);
6330 #ifdef FUNCTION_OUTGOING_VALUE
6331 outgoing = FUNCTION_OUTGOING_VALUE (type, current_function_decl);
6333 outgoing = FUNCTION_VALUE (type, current_function_decl);
6335 /* If this is a BLKmode structure being returned in registers, then use
6336 the mode computed in expand_return. */
6337 if (GET_MODE (outgoing) == BLKmode)
6339 GET_MODE (DECL_RTL (DECL_RESULT (current_function_decl))));
6340 REG_FUNCTION_VALUE_P (outgoing) = 1;
6343 if (GET_CODE (outgoing) == REG)
6344 (*doit) (outgoing, arg);
6345 else if (GET_CODE (outgoing) == PARALLEL)
6349 for (i = 0; i < XVECLEN (outgoing, 0); i++)
6351 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
6353 if (GET_CODE (x) == REG && REGNO (x) < FIRST_PSEUDO_REGISTER)
6360 do_clobber_return_reg (reg, arg)
6362 void *arg ATTRIBUTE_UNUSED;
6364 emit_insn (gen_rtx_CLOBBER (VOIDmode, reg));
6368 clobber_return_register ()
6370 diddle_return_value (do_clobber_return_reg, NULL);
6374 do_use_return_reg (reg, arg)
6376 void *arg ATTRIBUTE_UNUSED;
6378 emit_insn (gen_rtx_USE (VOIDmode, reg));
6382 use_return_register ()
6384 diddle_return_value (do_use_return_reg, NULL);
6387 /* Generate RTL for the end of the current function.
6388 FILENAME and LINE are the current position in the source file.
6390 It is up to language-specific callers to do cleanups for parameters--
6391 or else, supply 1 for END_BINDINGS and we will call expand_end_bindings. */
6394 expand_function_end (filename, line, end_bindings)
6395 const char *filename;
6401 #ifdef TRAMPOLINE_TEMPLATE
6402 static rtx initial_trampoline;
6405 finish_expr_for_function ();
6407 #ifdef NON_SAVING_SETJMP
6408 /* Don't put any variables in registers if we call setjmp
6409 on a machine that fails to restore the registers. */
6410 if (NON_SAVING_SETJMP && current_function_calls_setjmp)
6412 if (DECL_INITIAL (current_function_decl) != error_mark_node)
6413 setjmp_protect (DECL_INITIAL (current_function_decl));
6415 setjmp_protect_args ();
6419 /* Save the argument pointer if a save area was made for it. */
6420 if (arg_pointer_save_area)
6422 /* arg_pointer_save_area may not be a valid memory address, so we
6423 have to check it and fix it if necessary. */
6426 emit_move_insn (validize_mem (arg_pointer_save_area),
6427 virtual_incoming_args_rtx);
6428 seq = gen_sequence ();
6430 emit_insn_before (seq, tail_recursion_reentry);
6433 /* Initialize any trampolines required by this function. */
6434 for (link = trampoline_list; link; link = TREE_CHAIN (link))
6436 tree function = TREE_PURPOSE (link);
6437 rtx context ATTRIBUTE_UNUSED = lookup_static_chain (function);
6438 rtx tramp = RTL_EXPR_RTL (TREE_VALUE (link));
6439 #ifdef TRAMPOLINE_TEMPLATE
6444 #ifdef TRAMPOLINE_TEMPLATE
6445 /* First make sure this compilation has a template for
6446 initializing trampolines. */
6447 if (initial_trampoline == 0)
6449 end_temporary_allocation ();
6451 = gen_rtx_MEM (BLKmode, assemble_trampoline_template ());
6452 resume_temporary_allocation ();
6454 ggc_add_rtx_root (&initial_trampoline, 1);
6458 /* Generate insns to initialize the trampoline. */
6460 tramp = round_trampoline_addr (XEXP (tramp, 0));
6461 #ifdef TRAMPOLINE_TEMPLATE
6462 blktramp = change_address (initial_trampoline, BLKmode, tramp);
6463 emit_block_move (blktramp, initial_trampoline,
6464 GEN_INT (TRAMPOLINE_SIZE),
6465 TRAMPOLINE_ALIGNMENT);
6467 INITIALIZE_TRAMPOLINE (tramp, XEXP (DECL_RTL (function), 0), context);
6471 /* Put those insns at entry to the containing function (this one). */
6472 emit_insns_before (seq, tail_recursion_reentry);
6475 /* If we are doing stack checking and this function makes calls,
6476 do a stack probe at the start of the function to ensure we have enough
6477 space for another stack frame. */
6478 if (flag_stack_check && ! STACK_CHECK_BUILTIN)
6482 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
6483 if (GET_CODE (insn) == CALL_INSN)
6486 probe_stack_range (STACK_CHECK_PROTECT,
6487 GEN_INT (STACK_CHECK_MAX_FRAME_SIZE));
6490 emit_insns_before (seq, tail_recursion_reentry);
6495 /* Warn about unused parms if extra warnings were specified. */
6496 /* Either ``-W -Wunused'' or ``-Wunused-parameter'' enables this
6497 warning. WARN_UNUSED_PARAMETER is negative when set by
6499 if (warn_unused_parameter > 0
6500 || (warn_unused_parameter < 0 && extra_warnings))
6504 for (decl = DECL_ARGUMENTS (current_function_decl);
6505 decl; decl = TREE_CHAIN (decl))
6506 if (! TREE_USED (decl) && TREE_CODE (decl) == PARM_DECL
6507 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
6508 warning_with_decl (decl, "unused parameter `%s'");
6511 /* Delete handlers for nonlocal gotos if nothing uses them. */
6512 if (nonlocal_goto_handler_slots != 0
6513 && ! current_function_has_nonlocal_label)
6516 /* End any sequences that failed to be closed due to syntax errors. */
6517 while (in_sequence_p ())
6520 /* Outside function body, can't compute type's actual size
6521 until next function's body starts. */
6522 immediate_size_expand--;
6524 clear_pending_stack_adjust ();
6525 do_pending_stack_adjust ();
6527 /* Mark the end of the function body.
6528 If control reaches this insn, the function can drop through
6529 without returning a value. */
6530 emit_note (NULL_PTR, NOTE_INSN_FUNCTION_END);
6532 /* Must mark the last line number note in the function, so that the test
6533 coverage code can avoid counting the last line twice. This just tells
6534 the code to ignore the immediately following line note, since there
6535 already exists a copy of this note somewhere above. This line number
6536 note is still needed for debugging though, so we can't delete it. */
6537 if (flag_test_coverage)
6538 emit_note (NULL_PTR, NOTE_INSN_REPEATED_LINE_NUMBER);
6540 /* Output a linenumber for the end of the function.
6541 SDB depends on this. */
6542 emit_line_note_force (filename, line);
6544 /* Output the label for the actual return from the function,
6545 if one is expected. This happens either because a function epilogue
6546 is used instead of a return instruction, or because a return was done
6547 with a goto in order to run local cleanups, or because of pcc-style
6548 structure returning. */
6552 /* Before the return label, clobber the return registers so that
6553 they are not propogated live to the rest of the function. This
6554 can only happen with functions that drop through; if there had
6555 been a return statement, there would have either been a return
6556 rtx, or a jump to the return label. */
6557 clobber_return_register ();
6559 emit_label (return_label);
6562 /* C++ uses this. */
6564 expand_end_bindings (0, 0, 0);
6566 /* Now handle any leftover exception regions that may have been
6567 created for the parameters. */
6569 rtx last = get_last_insn ();
6572 expand_leftover_cleanups ();
6574 /* If there are any catch_clauses remaining, output them now. */
6575 emit_insns (catch_clauses);
6576 catch_clauses = catch_clauses_last = NULL_RTX;
6577 /* If the above emitted any code, may sure we jump around it. */
6578 if (last != get_last_insn ())
6580 label = gen_label_rtx ();
6581 last = emit_jump_insn_after (gen_jump (label), last);
6582 last = emit_barrier_after (last);
6587 if (current_function_instrument_entry_exit)
6589 rtx fun = DECL_RTL (current_function_decl);
6590 if (GET_CODE (fun) == MEM)
6591 fun = XEXP (fun, 0);
6594 emit_library_call (profile_function_exit_libfunc, 0, VOIDmode, 2,
6596 expand_builtin_return_addr (BUILT_IN_RETURN_ADDRESS,
6598 hard_frame_pointer_rtx),
6602 /* If we had calls to alloca, and this machine needs
6603 an accurate stack pointer to exit the function,
6604 insert some code to save and restore the stack pointer. */
6605 #ifdef EXIT_IGNORE_STACK
6606 if (! EXIT_IGNORE_STACK)
6608 if (current_function_calls_alloca)
6612 emit_stack_save (SAVE_FUNCTION, &tem, parm_birth_insn);
6613 emit_stack_restore (SAVE_FUNCTION, tem, NULL_RTX);
6616 /* If scalar return value was computed in a pseudo-reg,
6617 copy that to the hard return register. */
6618 if (DECL_RTL (DECL_RESULT (current_function_decl)) != 0
6619 && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG
6620 && (REGNO (DECL_RTL (DECL_RESULT (current_function_decl)))
6621 >= FIRST_PSEUDO_REGISTER))
6623 rtx real_decl_result;
6625 #ifdef FUNCTION_OUTGOING_VALUE
6627 = FUNCTION_OUTGOING_VALUE (TREE_TYPE (DECL_RESULT (current_function_decl)),
6628 current_function_decl);
6631 = FUNCTION_VALUE (TREE_TYPE (DECL_RESULT (current_function_decl)),
6632 current_function_decl);
6634 REG_FUNCTION_VALUE_P (real_decl_result) = 1;
6635 /* If this is a BLKmode structure being returned in registers, then use
6636 the mode computed in expand_return. */
6637 if (GET_MODE (real_decl_result) == BLKmode)
6638 PUT_MODE (real_decl_result,
6639 GET_MODE (DECL_RTL (DECL_RESULT (current_function_decl))));
6640 emit_move_insn (real_decl_result,
6641 DECL_RTL (DECL_RESULT (current_function_decl)));
6643 /* The delay slot scheduler assumes that current_function_return_rtx
6644 holds the hard register containing the return value, not a temporary
6646 current_function_return_rtx = real_decl_result;
6649 /* If returning a structure, arrange to return the address of the value
6650 in a place where debuggers expect to find it.
6652 If returning a structure PCC style,
6653 the caller also depends on this value.
6654 And current_function_returns_pcc_struct is not necessarily set. */
6655 if (current_function_returns_struct
6656 || current_function_returns_pcc_struct)
6659 XEXP (DECL_RTL (DECL_RESULT (current_function_decl)), 0);
6660 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
6661 #ifdef FUNCTION_OUTGOING_VALUE
6663 = FUNCTION_OUTGOING_VALUE (build_pointer_type (type),
6664 current_function_decl);
6667 = FUNCTION_VALUE (build_pointer_type (type),
6668 current_function_decl);
6671 /* Mark this as a function return value so integrate will delete the
6672 assignment and USE below when inlining this function. */
6673 REG_FUNCTION_VALUE_P (outgoing) = 1;
6675 emit_move_insn (outgoing, value_address);
6678 /* ??? This should no longer be necessary since stupid is no longer with
6679 us, but there are some parts of the compiler (eg reload_combine, and
6680 sh mach_dep_reorg) that still try and compute their own lifetime info
6681 instead of using the general framework. */
6682 use_return_register ();
6684 /* If this is an implementation of __throw, do what's necessary to
6685 communicate between __builtin_eh_return and the epilogue. */
6686 expand_eh_return ();
6688 /* Output a return insn if we are using one.
6689 Otherwise, let the rtl chain end here, to drop through
6690 into the epilogue. */
6695 emit_jump_insn (gen_return ());
6700 /* Fix up any gotos that jumped out to the outermost
6701 binding level of the function.
6702 Must follow emitting RETURN_LABEL. */
6704 /* If you have any cleanups to do at this point,
6705 and they need to create temporary variables,
6706 then you will lose. */
6707 expand_fixups (get_insns ());
6710 /* Extend a vector that records the INSN_UIDs of INSNS (either a
6711 sequence or a single insn). */
6714 record_insns (insns, vecp)
6718 if (GET_CODE (insns) == SEQUENCE)
6720 int len = XVECLEN (insns, 0);
6721 int i = VARRAY_SIZE (*vecp);
6723 VARRAY_GROW (*vecp, i + len);
6726 VARRAY_INT (*vecp, i) = INSN_UID (XVECEXP (insns, 0, len));
6732 int i = VARRAY_SIZE (*vecp);
6733 VARRAY_GROW (*vecp, i + 1);
6734 VARRAY_INT (*vecp, i) = INSN_UID (insns);
6738 /* Determine how many INSN_UIDs in VEC are part of INSN. */
6741 contains (insn, vec)
6747 if (GET_CODE (insn) == INSN
6748 && GET_CODE (PATTERN (insn)) == SEQUENCE)
6751 for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
6752 for (j = VARRAY_SIZE (vec) - 1; j >= 0; --j)
6753 if (INSN_UID (XVECEXP (PATTERN (insn), 0, i)) == VARRAY_INT (vec, j))
6759 for (j = VARRAY_SIZE (vec) - 1; j >= 0; --j)
6760 if (INSN_UID (insn) == VARRAY_INT (vec, j))
6767 prologue_epilogue_contains (insn)
6770 if (contains (insn, prologue))
6772 if (contains (insn, epilogue))
6778 sibcall_epilogue_contains (insn)
6781 if (sibcall_epilogue)
6782 return contains (insn, sibcall_epilogue);
6787 /* Insert gen_return at the end of block BB. This also means updating
6788 block_for_insn appropriately. */
6791 emit_return_into_block (bb, line_note)
6797 p = NEXT_INSN (bb->end);
6798 end = emit_jump_insn_after (gen_return (), bb->end);
6800 emit_line_note_after (NOTE_SOURCE_FILE (line_note),
6801 NOTE_LINE_NUMBER (line_note), bb->end);
6805 set_block_for_insn (p, bb);
6812 #endif /* HAVE_return */
6814 #ifdef HAVE_epilogue
6816 /* Modify SEQ, a SEQUENCE that is part of the epilogue, to no modifications
6817 to the stack pointer. */
6820 keep_stack_depressed (seq)
6824 rtx sp_from_reg = 0;
6825 int sp_modified_unknown = 0;
6827 /* If the epilogue is just a single instruction, it's OK as is */
6829 if (GET_CODE (seq) != SEQUENCE) return;
6831 /* Scan all insns in SEQ looking for ones that modified the stack
6832 pointer. Record if it modified the stack pointer by copying it
6833 from the frame pointer or if it modified it in some other way.
6834 Then modify any subsequent stack pointer references to take that
6835 into account. We start by only allowing SP to be copied from a
6836 register (presumably FP) and then be subsequently referenced. */
6838 for (i = 0; i < XVECLEN (seq, 0); i++)
6840 rtx insn = XVECEXP (seq, 0, i);
6842 if (GET_RTX_CLASS (GET_CODE (insn)) != 'i')
6845 if (reg_set_p (stack_pointer_rtx, insn))
6847 rtx set = single_set (insn);
6849 /* If SP is set as a side-effect, we can't support this. */
6853 if (GET_CODE (SET_SRC (set)) == REG)
6854 sp_from_reg = SET_SRC (set);
6856 sp_modified_unknown = 1;
6858 /* Don't allow the SP modification to happen. */
6859 PUT_CODE (insn, NOTE);
6860 NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
6861 NOTE_SOURCE_FILE (insn) = 0;
6863 else if (reg_referenced_p (stack_pointer_rtx, PATTERN (insn)))
6865 if (sp_modified_unknown)
6868 else if (sp_from_reg != 0)
6870 = replace_rtx (PATTERN (insn), stack_pointer_rtx, sp_from_reg);
6876 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
6877 this into place with notes indicating where the prologue ends and where
6878 the epilogue begins. Update the basic block information when possible. */
6881 thread_prologue_and_epilogue_insns (f)
6882 rtx f ATTRIBUTE_UNUSED;
6887 #ifdef HAVE_prologue
6888 rtx prologue_end = NULL_RTX;
6890 #if defined (HAVE_epilogue) || defined(HAVE_return)
6891 rtx epilogue_end = NULL_RTX;
6894 #ifdef HAVE_prologue
6898 seq = gen_prologue ();
6901 /* Retain a map of the prologue insns. */
6902 if (GET_CODE (seq) != SEQUENCE)
6904 record_insns (seq, &prologue);
6905 prologue_end = emit_note (NULL, NOTE_INSN_PROLOGUE_END);
6907 seq = gen_sequence ();
6910 /* If optimization is off, and perhaps in an empty function,
6911 the entry block will have no successors. */
6912 if (ENTRY_BLOCK_PTR->succ)
6914 /* Can't deal with multiple successsors of the entry block. */
6915 if (ENTRY_BLOCK_PTR->succ->succ_next)
6918 insert_insn_on_edge (seq, ENTRY_BLOCK_PTR->succ);
6922 emit_insn_after (seq, f);
6926 /* If the exit block has no non-fake predecessors, we don't need
6928 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
6929 if ((e->flags & EDGE_FAKE) == 0)
6935 if (optimize && HAVE_return)
6937 /* If we're allowed to generate a simple return instruction,
6938 then by definition we don't need a full epilogue. Examine
6939 the block that falls through to EXIT. If it does not
6940 contain any code, examine its predecessors and try to
6941 emit (conditional) return instructions. */
6947 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
6948 if (e->flags & EDGE_FALLTHRU)
6954 /* Verify that there are no active instructions in the last block. */
6956 while (label && GET_CODE (label) != CODE_LABEL)
6958 if (active_insn_p (label))
6960 label = PREV_INSN (label);
6963 if (last->head == label && GET_CODE (label) == CODE_LABEL)
6965 rtx epilogue_line_note = NULL_RTX;
6967 /* Locate the line number associated with the closing brace,
6968 if we can find one. */
6969 for (seq = get_last_insn ();
6970 seq && ! active_insn_p (seq);
6971 seq = PREV_INSN (seq))
6972 if (GET_CODE (seq) == NOTE && NOTE_LINE_NUMBER (seq) > 0)
6974 epilogue_line_note = seq;
6978 for (e = last->pred; e; e = e_next)
6980 basic_block bb = e->src;
6983 e_next = e->pred_next;
6984 if (bb == ENTRY_BLOCK_PTR)
6988 if ((GET_CODE (jump) != JUMP_INSN) || JUMP_LABEL (jump) != label)
6991 /* If we have an unconditional jump, we can replace that
6992 with a simple return instruction. */
6993 if (simplejump_p (jump))
6995 emit_return_into_block (bb, epilogue_line_note);
6996 flow_delete_insn (jump);
6999 /* If we have a conditional jump, we can try to replace
7000 that with a conditional return instruction. */
7001 else if (condjump_p (jump))
7005 ret = SET_SRC (PATTERN (jump));
7006 if (GET_CODE (XEXP (ret, 1)) == LABEL_REF)
7007 loc = &XEXP (ret, 1);
7009 loc = &XEXP (ret, 2);
7010 ret = gen_rtx_RETURN (VOIDmode);
7012 if (! validate_change (jump, loc, ret, 0))
7014 if (JUMP_LABEL (jump))
7015 LABEL_NUSES (JUMP_LABEL (jump))--;
7017 /* If this block has only one successor, it both jumps
7018 and falls through to the fallthru block, so we can't
7020 if (bb->succ->succ_next == NULL)
7026 /* Fix up the CFG for the successful change we just made. */
7027 redirect_edge_succ (e, EXIT_BLOCK_PTR);
7030 /* Emit a return insn for the exit fallthru block. Whether
7031 this is still reachable will be determined later. */
7033 emit_barrier_after (last->end);
7034 emit_return_into_block (last, epilogue_line_note);
7035 epilogue_end = last->end;
7040 #ifdef HAVE_epilogue
7043 /* Find the edge that falls through to EXIT. Other edges may exist
7044 due to RETURN instructions, but those don't need epilogues.
7045 There really shouldn't be a mixture -- either all should have
7046 been converted or none, however... */
7048 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7049 if (e->flags & EDGE_FALLTHRU)
7055 epilogue_end = emit_note (NULL, NOTE_INSN_EPILOGUE_BEG);
7057 seq = gen_epilogue ();
7059 /* If this function returns with the stack depressed, massage
7060 the epilogue to actually do that. */
7061 if (TYPE_RETURNS_STACK_DEPRESSED (TREE_TYPE (current_function_decl)))
7062 keep_stack_depressed (seq);
7064 emit_jump_insn (seq);
7066 /* Retain a map of the epilogue insns. */
7067 if (GET_CODE (seq) != SEQUENCE)
7069 record_insns (seq, &epilogue);
7071 seq = gen_sequence ();
7074 insert_insn_on_edge (seq, e);
7081 commit_edge_insertions ();
7083 #ifdef HAVE_sibcall_epilogue
7084 /* Emit sibling epilogues before any sibling call sites. */
7085 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7087 basic_block bb = e->src;
7092 if (GET_CODE (insn) != CALL_INSN
7093 || ! SIBLING_CALL_P (insn))
7097 seq = gen_sibcall_epilogue ();
7100 i = PREV_INSN (insn);
7101 newinsn = emit_insn_before (seq, insn);
7103 /* Update the UID to basic block map. */
7104 for (i = NEXT_INSN (i); i != insn; i = NEXT_INSN (i))
7105 set_block_for_insn (i, bb);
7107 /* Retain a map of the epilogue insns. Used in life analysis to
7108 avoid getting rid of sibcall epilogue insns. */
7109 record_insns (GET_CODE (seq) == SEQUENCE
7110 ? seq : newinsn, &sibcall_epilogue);
7114 #ifdef HAVE_prologue
7119 /* GDB handles `break f' by setting a breakpoint on the first
7120 line note after the prologue. Which means (1) that if
7121 there are line number notes before where we inserted the
7122 prologue we should move them, and (2) we should generate a
7123 note before the end of the first basic block, if there isn't
7124 one already there. */
7126 for (insn = prologue_end; insn; insn = prev)
7128 prev = PREV_INSN (insn);
7129 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
7131 /* Note that we cannot reorder the first insn in the
7132 chain, since rest_of_compilation relies on that
7133 remaining constant. */
7136 reorder_insns (insn, insn, prologue_end);
7140 /* Find the last line number note in the first block. */
7141 for (insn = BASIC_BLOCK (0)->end;
7142 insn != prologue_end;
7143 insn = PREV_INSN (insn))
7144 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
7147 /* If we didn't find one, make a copy of the first line number
7151 for (insn = next_active_insn (prologue_end);
7153 insn = PREV_INSN (insn))
7154 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
7156 emit_line_note_after (NOTE_SOURCE_FILE (insn),
7157 NOTE_LINE_NUMBER (insn),
7164 #ifdef HAVE_epilogue
7169 /* Similarly, move any line notes that appear after the epilogue.
7170 There is no need, however, to be quite so anal about the existance
7172 for (insn = epilogue_end; insn; insn = next)
7174 next = NEXT_INSN (insn);
7175 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
7176 reorder_insns (insn, insn, PREV_INSN (epilogue_end));
7182 /* Reposition the prologue-end and epilogue-begin notes after instruction
7183 scheduling and delayed branch scheduling. */
7186 reposition_prologue_and_epilogue_notes (f)
7187 rtx f ATTRIBUTE_UNUSED;
7189 #if defined (HAVE_prologue) || defined (HAVE_epilogue)
7192 if ((len = VARRAY_SIZE (prologue)) > 0)
7194 register rtx insn, note = 0;
7196 /* Scan from the beginning until we reach the last prologue insn.
7197 We apparently can't depend on basic_block_{head,end} after
7199 for (insn = f; len && insn; insn = NEXT_INSN (insn))
7201 if (GET_CODE (insn) == NOTE)
7203 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_PROLOGUE_END)
7206 else if ((len -= contains (insn, prologue)) == 0)
7209 /* Find the prologue-end note if we haven't already, and
7210 move it to just after the last prologue insn. */
7213 for (note = insn; (note = NEXT_INSN (note));)
7214 if (GET_CODE (note) == NOTE
7215 && NOTE_LINE_NUMBER (note) == NOTE_INSN_PROLOGUE_END)
7219 next = NEXT_INSN (note);
7221 /* Whether or not we can depend on BLOCK_HEAD,
7222 attempt to keep it up-to-date. */
7223 if (BLOCK_HEAD (0) == note)
7224 BLOCK_HEAD (0) = next;
7227 add_insn_after (note, insn);
7232 if ((len = VARRAY_SIZE (epilogue)) > 0)
7234 register rtx insn, note = 0;
7236 /* Scan from the end until we reach the first epilogue insn.
7237 We apparently can't depend on basic_block_{head,end} after
7239 for (insn = get_last_insn (); len && insn; insn = PREV_INSN (insn))
7241 if (GET_CODE (insn) == NOTE)
7243 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EPILOGUE_BEG)
7246 else if ((len -= contains (insn, epilogue)) == 0)
7248 /* Find the epilogue-begin note if we haven't already, and
7249 move it to just before the first epilogue insn. */
7252 for (note = insn; (note = PREV_INSN (note));)
7253 if (GET_CODE (note) == NOTE
7254 && NOTE_LINE_NUMBER (note) == NOTE_INSN_EPILOGUE_BEG)
7258 /* Whether or not we can depend on BLOCK_HEAD,
7259 attempt to keep it up-to-date. */
7261 && BLOCK_HEAD (n_basic_blocks-1) == insn)
7262 BLOCK_HEAD (n_basic_blocks-1) = note;
7265 add_insn_before (note, insn);
7269 #endif /* HAVE_prologue or HAVE_epilogue */
7272 /* Mark T for GC. */
7276 struct temp_slot *t;
7280 ggc_mark_rtx (t->slot);
7281 ggc_mark_rtx (t->address);
7282 ggc_mark_tree (t->rtl_expr);
7288 /* Mark P for GC. */
7291 mark_function_status (p)
7300 ggc_mark_rtx (p->arg_offset_rtx);
7302 if (p->x_parm_reg_stack_loc)
7303 for (i = p->x_max_parm_reg, r = p->x_parm_reg_stack_loc;
7307 ggc_mark_rtx (p->return_rtx);
7308 ggc_mark_rtx (p->x_cleanup_label);
7309 ggc_mark_rtx (p->x_return_label);
7310 ggc_mark_rtx (p->x_save_expr_regs);
7311 ggc_mark_rtx (p->x_stack_slot_list);
7312 ggc_mark_rtx (p->x_parm_birth_insn);
7313 ggc_mark_rtx (p->x_tail_recursion_label);
7314 ggc_mark_rtx (p->x_tail_recursion_reentry);
7315 ggc_mark_rtx (p->internal_arg_pointer);
7316 ggc_mark_rtx (p->x_arg_pointer_save_area);
7317 ggc_mark_tree (p->x_rtl_expr_chain);
7318 ggc_mark_rtx (p->x_last_parm_insn);
7319 ggc_mark_tree (p->x_context_display);
7320 ggc_mark_tree (p->x_trampoline_list);
7321 ggc_mark_rtx (p->epilogue_delay_list);
7323 mark_temp_slot (p->x_temp_slots);
7326 struct var_refs_queue *q = p->fixup_var_refs_queue;
7329 ggc_mark_rtx (q->modified);
7334 ggc_mark_rtx (p->x_nonlocal_goto_handler_slots);
7335 ggc_mark_rtx (p->x_nonlocal_goto_handler_labels);
7336 ggc_mark_rtx (p->x_nonlocal_goto_stack_level);
7337 ggc_mark_tree (p->x_nonlocal_labels);
7340 /* Mark the function chain ARG (which is really a struct function **)
7344 mark_function_chain (arg)
7347 struct function *f = *(struct function **) arg;
7349 for (; f; f = f->next_global)
7351 ggc_mark_tree (f->decl);
7353 mark_function_status (f);
7354 mark_eh_status (f->eh);
7355 mark_stmt_status (f->stmt);
7356 mark_expr_status (f->expr);
7357 mark_emit_status (f->emit);
7358 mark_varasm_status (f->varasm);
7360 if (mark_machine_status)
7361 (*mark_machine_status) (f);
7362 if (mark_lang_status)
7363 (*mark_lang_status) (f);
7365 if (f->original_arg_vector)
7366 ggc_mark_rtvec ((rtvec) f->original_arg_vector);
7367 if (f->original_decl_initial)
7368 ggc_mark_tree (f->original_decl_initial);
7372 /* Called once, at initialization, to initialize function.c. */
7375 init_function_once ()
7377 ggc_add_root (&all_functions, 1, sizeof all_functions,
7378 mark_function_chain);
7380 VARRAY_INT_INIT (prologue, 0, "prologue");
7381 VARRAY_INT_INIT (epilogue, 0, "epilogue");
7382 VARRAY_INT_INIT (sibcall_epilogue, 0, "sibcall_epilogue");