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 *));
297 static void purge_single_hard_subreg_set PARAMS ((rtx));
299 static void keep_stack_depressed PARAMS ((rtx));
301 static int is_addressof PARAMS ((rtx *, void *));
302 static struct hash_entry *insns_for_mem_newfunc PARAMS ((struct hash_entry *,
305 static unsigned long insns_for_mem_hash PARAMS ((hash_table_key));
306 static boolean insns_for_mem_comp PARAMS ((hash_table_key, hash_table_key));
307 static int insns_for_mem_walk PARAMS ((rtx *, void *));
308 static void compute_insns_for_mem PARAMS ((rtx, rtx, struct hash_table *));
309 static void mark_temp_slot PARAMS ((struct temp_slot *));
310 static void mark_function_status PARAMS ((struct function *));
311 static void mark_function_chain PARAMS ((void *));
312 static void prepare_function_start PARAMS ((void));
313 static void do_clobber_return_reg PARAMS ((rtx, void *));
314 static void do_use_return_reg PARAMS ((rtx, void *));
316 /* Pointer to chain of `struct function' for containing functions. */
317 struct function *outer_function_chain;
319 /* Given a function decl for a containing function,
320 return the `struct function' for it. */
323 find_function_data (decl)
328 for (p = outer_function_chain; p; p = p->next)
335 /* Save the current context for compilation of a nested function.
336 This is called from language-specific code. The caller should use
337 the save_lang_status callback to save any language-specific state,
338 since this function knows only about language-independent
342 push_function_context_to (context)
345 struct function *p, *context_data;
349 context_data = (context == current_function_decl
351 : find_function_data (context));
352 context_data->contains_functions = 1;
356 init_dummy_function_start ();
359 p->next = outer_function_chain;
360 outer_function_chain = p;
361 p->fixup_var_refs_queue = 0;
363 save_tree_status (p);
364 if (save_lang_status)
365 (*save_lang_status) (p);
366 if (save_machine_status)
367 (*save_machine_status) (p);
373 push_function_context ()
375 push_function_context_to (current_function_decl);
378 /* Restore the last saved context, at the end of a nested function.
379 This function is called from language-specific code. */
382 pop_function_context_from (context)
383 tree context ATTRIBUTE_UNUSED;
385 struct function *p = outer_function_chain;
386 struct var_refs_queue *queue;
387 struct var_refs_queue *next;
390 outer_function_chain = p->next;
392 current_function_decl = p->decl;
395 restore_tree_status (p);
396 restore_emit_status (p);
398 if (restore_machine_status)
399 (*restore_machine_status) (p);
400 if (restore_lang_status)
401 (*restore_lang_status) (p);
403 /* Finish doing put_var_into_stack for any of our variables
404 which became addressable during the nested function. */
405 for (queue = p->fixup_var_refs_queue; queue; queue = next)
408 fixup_var_refs (queue->modified, queue->promoted_mode,
409 queue->unsignedp, 0);
412 p->fixup_var_refs_queue = 0;
414 /* Reset variables that have known state during rtx generation. */
415 rtx_equal_function_value_matters = 1;
416 virtuals_instantiated = 0;
417 generating_concat_p = 1;
421 pop_function_context ()
423 pop_function_context_from (current_function_decl);
426 /* Clear out all parts of the state in F that can safely be discarded
427 after the function has been parsed, but not compiled, to let
428 garbage collection reclaim the memory. */
431 free_after_parsing (f)
434 /* f->expr->forced_labels is used by code generation. */
435 /* f->emit->regno_reg_rtx is used by code generation. */
436 /* f->varasm is used by code generation. */
437 /* f->eh->eh_return_stub_label is used by code generation. */
439 if (free_lang_status)
440 (*free_lang_status) (f);
441 free_stmt_status (f);
444 /* Clear out all parts of the state in F that can safely be discarded
445 after the function has been compiled, to let garbage collection
446 reclaim the memory. */
449 free_after_compilation (f)
452 struct temp_slot *ts;
453 struct temp_slot *next;
456 free_expr_status (f);
457 free_emit_status (f);
458 free_varasm_status (f);
460 if (free_machine_status)
461 (*free_machine_status) (f);
463 if (f->x_parm_reg_stack_loc)
464 free (f->x_parm_reg_stack_loc);
466 for (ts = f->x_temp_slots; ts; ts = next)
471 f->x_temp_slots = NULL;
473 f->arg_offset_rtx = NULL;
474 f->return_rtx = NULL;
475 f->internal_arg_pointer = NULL;
476 f->x_nonlocal_labels = NULL;
477 f->x_nonlocal_goto_handler_slots = NULL;
478 f->x_nonlocal_goto_handler_labels = NULL;
479 f->x_nonlocal_goto_stack_level = NULL;
480 f->x_cleanup_label = NULL;
481 f->x_return_label = NULL;
482 f->x_save_expr_regs = NULL;
483 f->x_stack_slot_list = NULL;
484 f->x_rtl_expr_chain = NULL;
485 f->x_tail_recursion_label = NULL;
486 f->x_tail_recursion_reentry = NULL;
487 f->x_arg_pointer_save_area = NULL;
488 f->x_context_display = NULL;
489 f->x_trampoline_list = NULL;
490 f->x_parm_birth_insn = NULL;
491 f->x_last_parm_insn = NULL;
492 f->x_parm_reg_stack_loc = NULL;
493 f->fixup_var_refs_queue = NULL;
494 f->original_arg_vector = NULL;
495 f->original_decl_initial = NULL;
496 f->inl_last_parm_insn = NULL;
497 f->epilogue_delay_list = NULL;
500 /* Allocate fixed slots in the stack frame of the current function. */
502 /* Return size needed for stack frame based on slots so far allocated in
504 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
505 the caller may have to do that. */
508 get_func_frame_size (f)
511 #ifdef FRAME_GROWS_DOWNWARD
512 return -f->x_frame_offset;
514 return f->x_frame_offset;
518 /* Return size needed for stack frame based on slots so far allocated.
519 This size counts from zero. It is not rounded to PREFERRED_STACK_BOUNDARY;
520 the caller may have to do that. */
524 return get_func_frame_size (cfun);
527 /* Allocate a stack slot of SIZE bytes and return a MEM rtx for it
528 with machine mode MODE.
530 ALIGN controls the amount of alignment for the address of the slot:
531 0 means according to MODE,
532 -1 means use BIGGEST_ALIGNMENT and round size to multiple of that,
533 positive specifies alignment boundary in bits.
535 We do not round to stack_boundary here.
537 FUNCTION specifies the function to allocate in. */
540 assign_stack_local_1 (mode, size, align, function)
541 enum machine_mode mode;
544 struct function *function;
546 register rtx x, addr;
547 int bigend_correction = 0;
550 /* Allocate in the memory associated with the function in whose frame
552 if (function != cfun)
553 push_obstacks (function->function_obstack,
554 function->function_maybepermanent_obstack);
561 alignment = BIGGEST_ALIGNMENT;
563 alignment = GET_MODE_ALIGNMENT (mode);
565 /* Allow the target to (possibly) increase the alignment of this
567 type = type_for_mode (mode, 0);
569 alignment = LOCAL_ALIGNMENT (type, alignment);
571 alignment /= BITS_PER_UNIT;
573 else if (align == -1)
575 alignment = BIGGEST_ALIGNMENT / BITS_PER_UNIT;
576 size = CEIL_ROUND (size, alignment);
579 alignment = align / BITS_PER_UNIT;
581 #ifdef FRAME_GROWS_DOWNWARD
582 function->x_frame_offset -= size;
585 /* Ignore alignment we can't do with expected alignment of the boundary. */
586 if (alignment * BITS_PER_UNIT > PREFERRED_STACK_BOUNDARY)
587 alignment = PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT;
589 if (function->stack_alignment_needed < alignment * BITS_PER_UNIT)
590 function->stack_alignment_needed = alignment * BITS_PER_UNIT;
592 /* Round frame offset to that alignment.
593 We must be careful here, since FRAME_OFFSET might be negative and
594 division with a negative dividend isn't as well defined as we might
595 like. So we instead assume that ALIGNMENT is a power of two and
596 use logical operations which are unambiguous. */
597 #ifdef FRAME_GROWS_DOWNWARD
598 function->x_frame_offset = FLOOR_ROUND (function->x_frame_offset, alignment);
600 function->x_frame_offset = CEIL_ROUND (function->x_frame_offset, alignment);
603 /* On a big-endian machine, if we are allocating more space than we will use,
604 use the least significant bytes of those that are allocated. */
605 if (BYTES_BIG_ENDIAN && mode != BLKmode)
606 bigend_correction = size - GET_MODE_SIZE (mode);
608 /* If we have already instantiated virtual registers, return the actual
609 address relative to the frame pointer. */
610 if (function == cfun && virtuals_instantiated)
611 addr = plus_constant (frame_pointer_rtx,
612 (frame_offset + bigend_correction
613 + STARTING_FRAME_OFFSET));
615 addr = plus_constant (virtual_stack_vars_rtx,
616 function->x_frame_offset + bigend_correction);
618 #ifndef FRAME_GROWS_DOWNWARD
619 function->x_frame_offset += size;
622 x = gen_rtx_MEM (mode, addr);
624 function->x_stack_slot_list
625 = gen_rtx_EXPR_LIST (VOIDmode, x, function->x_stack_slot_list);
627 if (function != cfun)
633 /* Wrapper around assign_stack_local_1; assign a local stack slot for the
637 assign_stack_local (mode, size, align)
638 enum machine_mode mode;
642 return assign_stack_local_1 (mode, size, align, cfun);
645 /* Allocate a temporary stack slot and record it for possible later
648 MODE is the machine mode to be given to the returned rtx.
650 SIZE is the size in units of the space required. We do no rounding here
651 since assign_stack_local will do any required rounding.
653 KEEP is 1 if this slot is to be retained after a call to
654 free_temp_slots. Automatic variables for a block are allocated
655 with this flag. KEEP is 2 if we allocate a longer term temporary,
656 whose lifetime is controlled by CLEANUP_POINT_EXPRs. KEEP is 3
657 if we are to allocate something at an inner level to be treated as
658 a variable in the block (e.g., a SAVE_EXPR).
660 TYPE is the type that will be used for the stack slot. */
663 assign_stack_temp_for_type (mode, size, keep, type)
664 enum machine_mode mode;
670 HOST_WIDE_INT alias_set;
671 struct temp_slot *p, *best_p = 0;
673 /* If SIZE is -1 it means that somebody tried to allocate a temporary
674 of a variable size. */
678 /* If we know the alias set for the memory that will be used, use
679 it. If there's no TYPE, then we don't know anything about the
680 alias set for the memory. */
682 alias_set = get_alias_set (type);
687 align = BIGGEST_ALIGNMENT;
689 align = GET_MODE_ALIGNMENT (mode);
692 type = type_for_mode (mode, 0);
695 align = LOCAL_ALIGNMENT (type, align);
697 /* Try to find an available, already-allocated temporary of the proper
698 mode which meets the size and alignment requirements. Choose the
699 smallest one with the closest alignment. */
700 for (p = temp_slots; p; p = p->next)
701 if (p->align >= align && p->size >= size && GET_MODE (p->slot) == mode
703 && (! flag_strict_aliasing
704 || (alias_set && p->alias_set == alias_set))
705 && (best_p == 0 || best_p->size > p->size
706 || (best_p->size == p->size && best_p->align > p->align)))
708 if (p->align == align && p->size == size)
716 /* Make our best, if any, the one to use. */
719 /* If there are enough aligned bytes left over, make them into a new
720 temp_slot so that the extra bytes don't get wasted. Do this only
721 for BLKmode slots, so that we can be sure of the alignment. */
722 if (GET_MODE (best_p->slot) == BLKmode)
724 int alignment = best_p->align / BITS_PER_UNIT;
725 HOST_WIDE_INT rounded_size = CEIL_ROUND (size, alignment);
727 if (best_p->size - rounded_size >= alignment)
729 p = (struct temp_slot *) xmalloc (sizeof (struct temp_slot));
730 p->in_use = p->addr_taken = 0;
731 p->size = best_p->size - rounded_size;
732 p->base_offset = best_p->base_offset + rounded_size;
733 p->full_size = best_p->full_size - rounded_size;
734 p->slot = gen_rtx_MEM (BLKmode,
735 plus_constant (XEXP (best_p->slot, 0),
737 p->align = best_p->align;
740 p->alias_set = best_p->alias_set;
741 p->next = temp_slots;
744 stack_slot_list = gen_rtx_EXPR_LIST (VOIDmode, p->slot,
747 best_p->size = rounded_size;
748 best_p->full_size = rounded_size;
755 /* If we still didn't find one, make a new temporary. */
758 HOST_WIDE_INT frame_offset_old = frame_offset;
760 p = (struct temp_slot *) xmalloc (sizeof (struct temp_slot));
762 /* We are passing an explicit alignment request to assign_stack_local.
763 One side effect of that is assign_stack_local will not round SIZE
764 to ensure the frame offset remains suitably aligned.
766 So for requests which depended on the rounding of SIZE, we go ahead
767 and round it now. We also make sure ALIGNMENT is at least
768 BIGGEST_ALIGNMENT. */
769 if (mode == BLKmode && align < BIGGEST_ALIGNMENT)
771 p->slot = assign_stack_local (mode,
773 ? CEIL_ROUND (size, align / BITS_PER_UNIT)
778 p->alias_set = alias_set;
780 /* The following slot size computation is necessary because we don't
781 know the actual size of the temporary slot until assign_stack_local
782 has performed all the frame alignment and size rounding for the
783 requested temporary. Note that extra space added for alignment
784 can be either above or below this stack slot depending on which
785 way the frame grows. We include the extra space if and only if it
786 is above this slot. */
787 #ifdef FRAME_GROWS_DOWNWARD
788 p->size = frame_offset_old - frame_offset;
793 /* Now define the fields used by combine_temp_slots. */
794 #ifdef FRAME_GROWS_DOWNWARD
795 p->base_offset = frame_offset;
796 p->full_size = frame_offset_old - frame_offset;
798 p->base_offset = frame_offset_old;
799 p->full_size = frame_offset - frame_offset_old;
802 p->next = temp_slots;
808 p->rtl_expr = seq_rtl_expr;
812 p->level = target_temp_slot_level;
817 p->level = var_temp_slot_level;
822 p->level = temp_slot_level;
826 /* We may be reusing an old slot, so clear any MEM flags that may have been
828 RTX_UNCHANGING_P (p->slot) = 0;
829 MEM_IN_STRUCT_P (p->slot) = 0;
830 MEM_SCALAR_P (p->slot) = 0;
831 MEM_ALIAS_SET (p->slot) = alias_set;
834 MEM_SET_IN_STRUCT_P (p->slot, AGGREGATE_TYPE_P (type));
839 /* Allocate a temporary stack slot and record it for possible later
840 reuse. First three arguments are same as in preceding function. */
843 assign_stack_temp (mode, size, keep)
844 enum machine_mode mode;
848 return assign_stack_temp_for_type (mode, size, keep, NULL_TREE);
851 /* Assign a temporary of given TYPE.
852 KEEP is as for assign_stack_temp.
853 MEMORY_REQUIRED is 1 if the result must be addressable stack memory;
854 it is 0 if a register is OK.
855 DONT_PROMOTE is 1 if we should not promote values in register
859 assign_temp (type, keep, memory_required, dont_promote)
863 int dont_promote ATTRIBUTE_UNUSED;
865 enum machine_mode mode = TYPE_MODE (type);
866 #ifndef PROMOTE_FOR_CALL_ONLY
867 int unsignedp = TREE_UNSIGNED (type);
870 if (mode == BLKmode || memory_required)
872 HOST_WIDE_INT size = int_size_in_bytes (type);
875 /* Zero sized arrays are GNU C extension. Set size to 1 to avoid
876 problems with allocating the stack space. */
880 /* Unfortunately, we don't yet know how to allocate variable-sized
881 temporaries. However, sometimes we have a fixed upper limit on
882 the size (which is stored in TYPE_ARRAY_MAX_SIZE) and can use that
883 instead. This is the case for Chill variable-sized strings. */
884 if (size == -1 && TREE_CODE (type) == ARRAY_TYPE
885 && TYPE_ARRAY_MAX_SIZE (type) != NULL_TREE
886 && host_integerp (TYPE_ARRAY_MAX_SIZE (type), 1))
887 size = tree_low_cst (TYPE_ARRAY_MAX_SIZE (type), 1);
889 tmp = assign_stack_temp_for_type (mode, size, keep, type);
893 #ifndef PROMOTE_FOR_CALL_ONLY
895 mode = promote_mode (type, mode, &unsignedp, 0);
898 return gen_reg_rtx (mode);
901 /* Combine temporary stack slots which are adjacent on the stack.
903 This allows for better use of already allocated stack space. This is only
904 done for BLKmode slots because we can be sure that we won't have alignment
905 problems in this case. */
908 combine_temp_slots ()
910 struct temp_slot *p, *q;
911 struct temp_slot *prev_p, *prev_q;
914 /* We can't combine slots, because the information about which slot
915 is in which alias set will be lost. */
916 if (flag_strict_aliasing)
919 /* If there are a lot of temp slots, don't do anything unless
920 high levels of optimizaton. */
921 if (! flag_expensive_optimizations)
922 for (p = temp_slots, num_slots = 0; p; p = p->next, num_slots++)
923 if (num_slots > 100 || (num_slots > 10 && optimize == 0))
926 for (p = temp_slots, prev_p = 0; p; p = prev_p ? prev_p->next : temp_slots)
930 if (! p->in_use && GET_MODE (p->slot) == BLKmode)
931 for (q = p->next, prev_q = p; q; q = prev_q->next)
934 if (! q->in_use && GET_MODE (q->slot) == BLKmode)
936 if (p->base_offset + p->full_size == q->base_offset)
938 /* Q comes after P; combine Q into P. */
940 p->full_size += q->full_size;
943 else if (q->base_offset + q->full_size == p->base_offset)
945 /* P comes after Q; combine P into Q. */
947 q->full_size += p->full_size;
952 /* Either delete Q or advance past it. */
955 prev_q->next = q->next;
961 /* Either delete P or advance past it. */
965 prev_p->next = p->next;
967 temp_slots = p->next;
974 /* Find the temp slot corresponding to the object at address X. */
976 static struct temp_slot *
977 find_temp_slot_from_address (x)
983 for (p = temp_slots; p; p = p->next)
988 else if (XEXP (p->slot, 0) == x
990 || (GET_CODE (x) == PLUS
991 && XEXP (x, 0) == virtual_stack_vars_rtx
992 && GET_CODE (XEXP (x, 1)) == CONST_INT
993 && INTVAL (XEXP (x, 1)) >= p->base_offset
994 && INTVAL (XEXP (x, 1)) < p->base_offset + p->full_size))
997 else if (p->address != 0 && GET_CODE (p->address) == EXPR_LIST)
998 for (next = p->address; next; next = XEXP (next, 1))
999 if (XEXP (next, 0) == x)
1003 /* If we have a sum involving a register, see if it points to a temp
1005 if (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 0)) == REG
1006 && (p = find_temp_slot_from_address (XEXP (x, 0))) != 0)
1008 else if (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 1)) == REG
1009 && (p = find_temp_slot_from_address (XEXP (x, 1))) != 0)
1015 /* Indicate that NEW is an alternate way of referring to the temp slot
1016 that previously was known by OLD. */
1019 update_temp_slot_address (old, new)
1022 struct temp_slot *p;
1024 if (rtx_equal_p (old, new))
1027 p = find_temp_slot_from_address (old);
1029 /* If we didn't find one, see if both OLD is a PLUS. If so, and NEW
1030 is a register, see if one operand of the PLUS is a temporary
1031 location. If so, NEW points into it. Otherwise, if both OLD and
1032 NEW are a PLUS and if there is a register in common between them.
1033 If so, try a recursive call on those values. */
1036 if (GET_CODE (old) != PLUS)
1039 if (GET_CODE (new) == REG)
1041 update_temp_slot_address (XEXP (old, 0), new);
1042 update_temp_slot_address (XEXP (old, 1), new);
1045 else if (GET_CODE (new) != PLUS)
1048 if (rtx_equal_p (XEXP (old, 0), XEXP (new, 0)))
1049 update_temp_slot_address (XEXP (old, 1), XEXP (new, 1));
1050 else if (rtx_equal_p (XEXP (old, 1), XEXP (new, 0)))
1051 update_temp_slot_address (XEXP (old, 0), XEXP (new, 1));
1052 else if (rtx_equal_p (XEXP (old, 0), XEXP (new, 1)))
1053 update_temp_slot_address (XEXP (old, 1), XEXP (new, 0));
1054 else if (rtx_equal_p (XEXP (old, 1), XEXP (new, 1)))
1055 update_temp_slot_address (XEXP (old, 0), XEXP (new, 0));
1060 /* Otherwise add an alias for the temp's address. */
1061 else if (p->address == 0)
1065 if (GET_CODE (p->address) != EXPR_LIST)
1066 p->address = gen_rtx_EXPR_LIST (VOIDmode, p->address, NULL_RTX);
1068 p->address = gen_rtx_EXPR_LIST (VOIDmode, new, p->address);
1072 /* If X could be a reference to a temporary slot, mark the fact that its
1073 address was taken. */
1076 mark_temp_addr_taken (x)
1079 struct temp_slot *p;
1084 /* If X is not in memory or is at a constant address, it cannot be in
1085 a temporary slot. */
1086 if (GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0)))
1089 p = find_temp_slot_from_address (XEXP (x, 0));
1094 /* If X could be a reference to a temporary slot, mark that slot as
1095 belonging to the to one level higher than the current level. If X
1096 matched one of our slots, just mark that one. Otherwise, we can't
1097 easily predict which it is, so upgrade all of them. Kept slots
1098 need not be touched.
1100 This is called when an ({...}) construct occurs and a statement
1101 returns a value in memory. */
1104 preserve_temp_slots (x)
1107 struct temp_slot *p = 0;
1109 /* If there is no result, we still might have some objects whose address
1110 were taken, so we need to make sure they stay around. */
1113 for (p = temp_slots; p; p = p->next)
1114 if (p->in_use && p->level == temp_slot_level && p->addr_taken)
1120 /* If X is a register that is being used as a pointer, see if we have
1121 a temporary slot we know it points to. To be consistent with
1122 the code below, we really should preserve all non-kept slots
1123 if we can't find a match, but that seems to be much too costly. */
1124 if (GET_CODE (x) == REG && REGNO_POINTER_FLAG (REGNO (x)))
1125 p = find_temp_slot_from_address (x);
1127 /* If X is not in memory or is at a constant address, it cannot be in
1128 a temporary slot, but it can contain something whose address was
1130 if (p == 0 && (GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0))))
1132 for (p = temp_slots; p; p = p->next)
1133 if (p->in_use && p->level == temp_slot_level && p->addr_taken)
1139 /* First see if we can find a match. */
1141 p = find_temp_slot_from_address (XEXP (x, 0));
1145 /* Move everything at our level whose address was taken to our new
1146 level in case we used its address. */
1147 struct temp_slot *q;
1149 if (p->level == temp_slot_level)
1151 for (q = temp_slots; q; q = q->next)
1152 if (q != p && q->addr_taken && q->level == p->level)
1161 /* Otherwise, preserve all non-kept slots at this level. */
1162 for (p = temp_slots; p; p = p->next)
1163 if (p->in_use && p->level == temp_slot_level && ! p->keep)
1167 /* X is the result of an RTL_EXPR. If it is a temporary slot associated
1168 with that RTL_EXPR, promote it into a temporary slot at the present
1169 level so it will not be freed when we free slots made in the
1173 preserve_rtl_expr_result (x)
1176 struct temp_slot *p;
1178 /* If X is not in memory or is at a constant address, it cannot be in
1179 a temporary slot. */
1180 if (x == 0 || GET_CODE (x) != MEM || CONSTANT_P (XEXP (x, 0)))
1183 /* If we can find a match, move it to our level unless it is already at
1185 p = find_temp_slot_from_address (XEXP (x, 0));
1188 p->level = MIN (p->level, temp_slot_level);
1195 /* Free all temporaries used so far. This is normally called at the end
1196 of generating code for a statement. Don't free any temporaries
1197 currently in use for an RTL_EXPR that hasn't yet been emitted.
1198 We could eventually do better than this since it can be reused while
1199 generating the same RTL_EXPR, but this is complex and probably not
1205 struct temp_slot *p;
1207 for (p = temp_slots; p; p = p->next)
1208 if (p->in_use && p->level == temp_slot_level && ! p->keep
1209 && p->rtl_expr == 0)
1212 combine_temp_slots ();
1215 /* Free all temporary slots used in T, an RTL_EXPR node. */
1218 free_temps_for_rtl_expr (t)
1221 struct temp_slot *p;
1223 for (p = temp_slots; p; p = p->next)
1224 if (p->rtl_expr == t)
1226 /* If this slot is below the current TEMP_SLOT_LEVEL, then it
1227 needs to be preserved. This can happen if a temporary in
1228 the RTL_EXPR was addressed; preserve_temp_slots will move
1229 the temporary into a higher level. */
1230 if (temp_slot_level <= p->level)
1233 p->rtl_expr = NULL_TREE;
1236 combine_temp_slots ();
1239 /* Mark all temporaries ever allocated in this function as not suitable
1240 for reuse until the current level is exited. */
1243 mark_all_temps_used ()
1245 struct temp_slot *p;
1247 for (p = temp_slots; p; p = p->next)
1249 p->in_use = p->keep = 1;
1250 p->level = MIN (p->level, temp_slot_level);
1254 /* Push deeper into the nesting level for stack temporaries. */
1262 /* Likewise, but save the new level as the place to allocate variables
1267 push_temp_slots_for_block ()
1271 var_temp_slot_level = temp_slot_level;
1274 /* Likewise, but save the new level as the place to allocate temporaries
1275 for TARGET_EXPRs. */
1278 push_temp_slots_for_target ()
1282 target_temp_slot_level = temp_slot_level;
1285 /* Set and get the value of target_temp_slot_level. The only
1286 permitted use of these functions is to save and restore this value. */
1289 get_target_temp_slot_level ()
1291 return target_temp_slot_level;
1295 set_target_temp_slot_level (level)
1298 target_temp_slot_level = level;
1302 /* Pop a temporary nesting level. All slots in use in the current level
1308 struct temp_slot *p;
1310 for (p = temp_slots; p; p = p->next)
1311 if (p->in_use && p->level == temp_slot_level && p->rtl_expr == 0)
1314 combine_temp_slots ();
1319 /* Initialize temporary slots. */
1324 /* We have not allocated any temporaries yet. */
1326 temp_slot_level = 0;
1327 var_temp_slot_level = 0;
1328 target_temp_slot_level = 0;
1331 /* Retroactively move an auto variable from a register to a stack slot.
1332 This is done when an address-reference to the variable is seen. */
1335 put_var_into_stack (decl)
1339 enum machine_mode promoted_mode, decl_mode;
1340 struct function *function = 0;
1342 int can_use_addressof;
1343 int volatilep = TREE_CODE (decl) != SAVE_EXPR && TREE_THIS_VOLATILE (decl);
1344 int usedp = (TREE_USED (decl)
1345 || (TREE_CODE (decl) != SAVE_EXPR && DECL_INITIAL (decl) != 0));
1347 context = decl_function_context (decl);
1349 /* Get the current rtl used for this object and its original mode. */
1350 reg = TREE_CODE (decl) == SAVE_EXPR ? SAVE_EXPR_RTL (decl) : DECL_RTL (decl);
1352 /* No need to do anything if decl has no rtx yet
1353 since in that case caller is setting TREE_ADDRESSABLE
1354 and a stack slot will be assigned when the rtl is made. */
1358 /* Get the declared mode for this object. */
1359 decl_mode = (TREE_CODE (decl) == SAVE_EXPR ? TYPE_MODE (TREE_TYPE (decl))
1360 : DECL_MODE (decl));
1361 /* Get the mode it's actually stored in. */
1362 promoted_mode = GET_MODE (reg);
1364 /* If this variable comes from an outer function,
1365 find that function's saved context. */
1366 if (context != current_function_decl && context != inline_function_decl)
1367 for (function = outer_function_chain; function; function = function->next)
1368 if (function->decl == context)
1371 /* If this is a variable-size object with a pseudo to address it,
1372 put that pseudo into the stack, if the var is nonlocal. */
1373 if (TREE_CODE (decl) != SAVE_EXPR && DECL_NONLOCAL (decl)
1374 && GET_CODE (reg) == MEM
1375 && GET_CODE (XEXP (reg, 0)) == REG
1376 && REGNO (XEXP (reg, 0)) > LAST_VIRTUAL_REGISTER)
1378 reg = XEXP (reg, 0);
1379 decl_mode = promoted_mode = GET_MODE (reg);
1385 /* FIXME make it work for promoted modes too */
1386 && decl_mode == promoted_mode
1387 #ifdef NON_SAVING_SETJMP
1388 && ! (NON_SAVING_SETJMP && current_function_calls_setjmp)
1392 /* If we can't use ADDRESSOF, make sure we see through one we already
1394 if (! can_use_addressof && GET_CODE (reg) == MEM
1395 && GET_CODE (XEXP (reg, 0)) == ADDRESSOF)
1396 reg = XEXP (XEXP (reg, 0), 0);
1398 /* Now we should have a value that resides in one or more pseudo regs. */
1400 if (GET_CODE (reg) == REG)
1402 /* If this variable lives in the current function and we don't need
1403 to put things in the stack for the sake of setjmp, try to keep it
1404 in a register until we know we actually need the address. */
1405 if (can_use_addressof)
1406 gen_mem_addressof (reg, decl);
1408 put_reg_into_stack (function, reg, TREE_TYPE (decl), promoted_mode,
1409 decl_mode, volatilep, 0, usedp, 0);
1411 else if (GET_CODE (reg) == CONCAT)
1413 /* A CONCAT contains two pseudos; put them both in the stack.
1414 We do it so they end up consecutive.
1415 We fixup references to the parts only after we fixup references
1416 to the whole CONCAT, lest we do double fixups for the latter
1418 enum machine_mode part_mode = GET_MODE (XEXP (reg, 0));
1419 tree part_type = type_for_mode (part_mode, 0);
1420 rtx lopart = XEXP (reg, 0);
1421 rtx hipart = XEXP (reg, 1);
1422 #ifdef FRAME_GROWS_DOWNWARD
1423 /* Since part 0 should have a lower address, do it second. */
1424 put_reg_into_stack (function, hipart, part_type, part_mode,
1425 part_mode, volatilep, 0, 0, 0);
1426 put_reg_into_stack (function, lopart, part_type, part_mode,
1427 part_mode, volatilep, 0, 0, 0);
1429 put_reg_into_stack (function, lopart, part_type, part_mode,
1430 part_mode, volatilep, 0, 0, 0);
1431 put_reg_into_stack (function, hipart, part_type, part_mode,
1432 part_mode, volatilep, 0, 0, 0);
1435 /* Change the CONCAT into a combined MEM for both parts. */
1436 PUT_CODE (reg, MEM);
1437 set_mem_attributes (reg, decl, 1);
1439 /* The two parts are in memory order already.
1440 Use the lower parts address as ours. */
1441 XEXP (reg, 0) = XEXP (XEXP (reg, 0), 0);
1442 /* Prevent sharing of rtl that might lose. */
1443 if (GET_CODE (XEXP (reg, 0)) == PLUS)
1444 XEXP (reg, 0) = copy_rtx (XEXP (reg, 0));
1447 schedule_fixup_var_refs (function, reg, TREE_TYPE (decl),
1449 schedule_fixup_var_refs (function, lopart, part_type, part_mode, 0);
1450 schedule_fixup_var_refs (function, hipart, part_type, part_mode, 0);
1456 if (current_function_check_memory_usage)
1457 emit_library_call (chkr_set_right_libfunc, LCT_CONST_MAKE_BLOCK, VOIDmode,
1458 3, XEXP (reg, 0), Pmode,
1459 GEN_INT (GET_MODE_SIZE (GET_MODE (reg))),
1460 TYPE_MODE (sizetype),
1461 GEN_INT (MEMORY_USE_RW),
1462 TYPE_MODE (integer_type_node));
1465 /* Subroutine of put_var_into_stack. This puts a single pseudo reg REG
1466 into the stack frame of FUNCTION (0 means the current function).
1467 DECL_MODE is the machine mode of the user-level data type.
1468 PROMOTED_MODE is the machine mode of the register.
1469 VOLATILE_P is nonzero if this is for a "volatile" decl.
1470 USED_P is nonzero if this reg might have already been used in an insn. */
1473 put_reg_into_stack (function, reg, type, promoted_mode, decl_mode, volatile_p,
1474 original_regno, used_p, ht)
1475 struct function *function;
1478 enum machine_mode promoted_mode, decl_mode;
1480 unsigned int original_regno;
1482 struct hash_table *ht;
1484 struct function *func = function ? function : cfun;
1486 unsigned int regno = original_regno;
1489 regno = REGNO (reg);
1491 if (regno < func->x_max_parm_reg)
1492 new = func->x_parm_reg_stack_loc[regno];
1495 new = assign_stack_local_1 (decl_mode, GET_MODE_SIZE (decl_mode), 0, func);
1497 PUT_CODE (reg, MEM);
1498 PUT_MODE (reg, decl_mode);
1499 XEXP (reg, 0) = XEXP (new, 0);
1500 /* `volatil' bit means one thing for MEMs, another entirely for REGs. */
1501 MEM_VOLATILE_P (reg) = volatile_p;
1503 /* If this is a memory ref that contains aggregate components,
1504 mark it as such for cse and loop optimize. If we are reusing a
1505 previously generated stack slot, then we need to copy the bit in
1506 case it was set for other reasons. For instance, it is set for
1507 __builtin_va_alist. */
1510 MEM_SET_IN_STRUCT_P (reg,
1511 AGGREGATE_TYPE_P (type) || MEM_IN_STRUCT_P (new));
1512 MEM_ALIAS_SET (reg) = get_alias_set (type);
1515 schedule_fixup_var_refs (function, reg, type, promoted_mode, ht);
1518 /* Make sure that all refs to the variable, previously made
1519 when it was a register, are fixed up to be valid again.
1520 See function above for meaning of arguments. */
1522 schedule_fixup_var_refs (function, reg, type, promoted_mode, ht)
1523 struct function *function;
1526 enum machine_mode promoted_mode;
1527 struct hash_table *ht;
1529 int unsigned_p = type ? TREE_UNSIGNED (type) : 0;
1533 struct var_refs_queue *temp;
1536 = (struct var_refs_queue *) xmalloc (sizeof (struct var_refs_queue));
1537 temp->modified = reg;
1538 temp->promoted_mode = promoted_mode;
1539 temp->unsignedp = unsigned_p;
1540 temp->next = function->fixup_var_refs_queue;
1541 function->fixup_var_refs_queue = temp;
1544 /* Variable is local; fix it up now. */
1545 fixup_var_refs (reg, promoted_mode, unsigned_p, ht);
1549 fixup_var_refs (var, promoted_mode, unsignedp, ht)
1551 enum machine_mode promoted_mode;
1553 struct hash_table *ht;
1556 rtx first_insn = get_insns ();
1557 struct sequence_stack *stack = seq_stack;
1558 tree rtl_exps = rtl_expr_chain;
1561 /* Must scan all insns for stack-refs that exceed the limit. */
1562 fixup_var_refs_insns (var, promoted_mode, unsignedp, first_insn,
1564 /* If there's a hash table, it must record all uses of VAR. */
1568 /* Scan all pending sequences too. */
1569 for (; stack; stack = stack->next)
1571 push_to_sequence (stack->first);
1572 fixup_var_refs_insns (var, promoted_mode, unsignedp,
1573 stack->first, stack->next != 0, 0);
1574 /* Update remembered end of sequence
1575 in case we added an insn at the end. */
1576 stack->last = get_last_insn ();
1580 /* Scan all waiting RTL_EXPRs too. */
1581 for (pending = rtl_exps; pending; pending = TREE_CHAIN (pending))
1583 rtx seq = RTL_EXPR_SEQUENCE (TREE_VALUE (pending));
1584 if (seq != const0_rtx && seq != 0)
1586 push_to_sequence (seq);
1587 fixup_var_refs_insns (var, promoted_mode, unsignedp, seq, 0, 0);
1592 /* Scan the catch clauses for exception handling too. */
1593 push_to_full_sequence (catch_clauses, catch_clauses_last);
1594 fixup_var_refs_insns (var, promoted_mode, unsignedp, catch_clauses, 0, 0);
1595 end_full_sequence (&catch_clauses, &catch_clauses_last);
1597 /* Scan sequences saved in CALL_PLACEHOLDERS too. */
1598 for (insn = first_insn; insn; insn = NEXT_INSN (insn))
1600 if (GET_CODE (insn) == CALL_INSN
1601 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
1605 /* Look at the Normal call, sibling call and tail recursion
1606 sequences attached to the CALL_PLACEHOLDER. */
1607 for (i = 0; i < 3; i++)
1609 rtx seq = XEXP (PATTERN (insn), i);
1612 push_to_sequence (seq);
1613 fixup_var_refs_insns (var, promoted_mode, unsignedp,
1615 XEXP (PATTERN (insn), i) = get_insns ();
1623 /* REPLACEMENTS is a pointer to a list of the struct fixup_replacement and X is
1624 some part of an insn. Return a struct fixup_replacement whose OLD
1625 value is equal to X. Allocate a new structure if no such entry exists. */
1627 static struct fixup_replacement *
1628 find_fixup_replacement (replacements, x)
1629 struct fixup_replacement **replacements;
1632 struct fixup_replacement *p;
1634 /* See if we have already replaced this. */
1635 for (p = *replacements; p != 0 && ! rtx_equal_p (p->old, x); p = p->next)
1640 p = (struct fixup_replacement *) oballoc (sizeof (struct fixup_replacement));
1643 p->next = *replacements;
1650 /* Scan the insn-chain starting with INSN for refs to VAR
1651 and fix them up. TOPLEVEL is nonzero if this chain is the
1652 main chain of insns for the current function. */
1655 fixup_var_refs_insns (var, promoted_mode, unsignedp, insn, toplevel, ht)
1657 enum machine_mode promoted_mode;
1661 struct hash_table *ht;
1664 rtx insn_list = NULL_RTX;
1666 /* If we already know which INSNs reference VAR there's no need
1667 to walk the entire instruction chain. */
1670 insn_list = ((struct insns_for_mem_entry *)
1671 hash_lookup (ht, var, /*create=*/0, /*copy=*/0))->insns;
1672 insn = insn_list ? XEXP (insn_list, 0) : NULL_RTX;
1673 insn_list = XEXP (insn_list, 1);
1678 rtx next = NEXT_INSN (insn);
1679 rtx set, prev, prev_set;
1684 /* Remember the notes in case we delete the insn. */
1685 note = REG_NOTES (insn);
1687 /* If this is a CLOBBER of VAR, delete it.
1689 If it has a REG_LIBCALL note, delete the REG_LIBCALL
1690 and REG_RETVAL notes too. */
1691 if (GET_CODE (PATTERN (insn)) == CLOBBER
1692 && (XEXP (PATTERN (insn), 0) == var
1693 || (GET_CODE (XEXP (PATTERN (insn), 0)) == CONCAT
1694 && (XEXP (XEXP (PATTERN (insn), 0), 0) == var
1695 || XEXP (XEXP (PATTERN (insn), 0), 1) == var))))
1697 if ((note = find_reg_note (insn, REG_LIBCALL, NULL_RTX)) != 0)
1698 /* The REG_LIBCALL note will go away since we are going to
1699 turn INSN into a NOTE, so just delete the
1700 corresponding REG_RETVAL note. */
1701 remove_note (XEXP (note, 0),
1702 find_reg_note (XEXP (note, 0), REG_RETVAL,
1705 /* In unoptimized compilation, we shouldn't call delete_insn
1706 except in jump.c doing warnings. */
1707 PUT_CODE (insn, NOTE);
1708 NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
1709 NOTE_SOURCE_FILE (insn) = 0;
1712 /* The insn to load VAR from a home in the arglist
1713 is now a no-op. When we see it, just delete it.
1714 Similarly if this is storing VAR from a register from which
1715 it was loaded in the previous insn. This will occur
1716 when an ADDRESSOF was made for an arglist slot. */
1718 && (set = single_set (insn)) != 0
1719 && SET_DEST (set) == var
1720 /* If this represents the result of an insn group,
1721 don't delete the insn. */
1722 && find_reg_note (insn, REG_RETVAL, NULL_RTX) == 0
1723 && (rtx_equal_p (SET_SRC (set), var)
1724 || (GET_CODE (SET_SRC (set)) == REG
1725 && (prev = prev_nonnote_insn (insn)) != 0
1726 && (prev_set = single_set (prev)) != 0
1727 && SET_DEST (prev_set) == SET_SRC (set)
1728 && rtx_equal_p (SET_SRC (prev_set), var))))
1730 /* In unoptimized compilation, we shouldn't call delete_insn
1731 except in jump.c doing warnings. */
1732 PUT_CODE (insn, NOTE);
1733 NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
1734 NOTE_SOURCE_FILE (insn) = 0;
1735 if (insn == last_parm_insn)
1736 last_parm_insn = PREV_INSN (next);
1740 struct fixup_replacement *replacements = 0;
1741 rtx next_insn = NEXT_INSN (insn);
1743 if (SMALL_REGISTER_CLASSES)
1745 /* If the insn that copies the results of a CALL_INSN
1746 into a pseudo now references VAR, we have to use an
1747 intermediate pseudo since we want the life of the
1748 return value register to be only a single insn.
1750 If we don't use an intermediate pseudo, such things as
1751 address computations to make the address of VAR valid
1752 if it is not can be placed between the CALL_INSN and INSN.
1754 To make sure this doesn't happen, we record the destination
1755 of the CALL_INSN and see if the next insn uses both that
1758 if (call_dest != 0 && GET_CODE (insn) == INSN
1759 && reg_mentioned_p (var, PATTERN (insn))
1760 && reg_mentioned_p (call_dest, PATTERN (insn)))
1762 rtx temp = gen_reg_rtx (GET_MODE (call_dest));
1764 emit_insn_before (gen_move_insn (temp, call_dest), insn);
1766 PATTERN (insn) = replace_rtx (PATTERN (insn),
1770 if (GET_CODE (insn) == CALL_INSN
1771 && GET_CODE (PATTERN (insn)) == SET)
1772 call_dest = SET_DEST (PATTERN (insn));
1773 else if (GET_CODE (insn) == CALL_INSN
1774 && GET_CODE (PATTERN (insn)) == PARALLEL
1775 && GET_CODE (XVECEXP (PATTERN (insn), 0, 0)) == SET)
1776 call_dest = SET_DEST (XVECEXP (PATTERN (insn), 0, 0));
1781 /* See if we have to do anything to INSN now that VAR is in
1782 memory. If it needs to be loaded into a pseudo, use a single
1783 pseudo for the entire insn in case there is a MATCH_DUP
1784 between two operands. We pass a pointer to the head of
1785 a list of struct fixup_replacements. If fixup_var_refs_1
1786 needs to allocate pseudos or replacement MEMs (for SUBREGs),
1787 it will record them in this list.
1789 If it allocated a pseudo for any replacement, we copy into
1792 fixup_var_refs_1 (var, promoted_mode, &PATTERN (insn), insn,
1795 /* If this is last_parm_insn, and any instructions were output
1796 after it to fix it up, then we must set last_parm_insn to
1797 the last such instruction emitted. */
1798 if (insn == last_parm_insn)
1799 last_parm_insn = PREV_INSN (next_insn);
1801 while (replacements)
1803 if (GET_CODE (replacements->new) == REG)
1808 /* OLD might be a (subreg (mem)). */
1809 if (GET_CODE (replacements->old) == SUBREG)
1811 = fixup_memory_subreg (replacements->old, insn, 0);
1814 = fixup_stack_1 (replacements->old, insn);
1816 insert_before = insn;
1818 /* If we are changing the mode, do a conversion.
1819 This might be wasteful, but combine.c will
1820 eliminate much of the waste. */
1822 if (GET_MODE (replacements->new)
1823 != GET_MODE (replacements->old))
1826 convert_move (replacements->new,
1827 replacements->old, unsignedp);
1828 seq = gen_sequence ();
1832 seq = gen_move_insn (replacements->new,
1835 emit_insn_before (seq, insert_before);
1838 replacements = replacements->next;
1842 /* Also fix up any invalid exprs in the REG_NOTES of this insn.
1843 But don't touch other insns referred to by reg-notes;
1844 we will get them elsewhere. */
1847 if (GET_CODE (note) != INSN_LIST)
1849 = walk_fixup_memory_subreg (XEXP (note, 0), insn, 1);
1850 note = XEXP (note, 1);
1858 insn = XEXP (insn_list, 0);
1859 insn_list = XEXP (insn_list, 1);
1866 /* VAR is a MEM that used to be a pseudo register with mode PROMOTED_MODE.
1867 See if the rtx expression at *LOC in INSN needs to be changed.
1869 REPLACEMENTS is a pointer to a list head that starts out zero, but may
1870 contain a list of original rtx's and replacements. If we find that we need
1871 to modify this insn by replacing a memory reference with a pseudo or by
1872 making a new MEM to implement a SUBREG, we consult that list to see if
1873 we have already chosen a replacement. If none has already been allocated,
1874 we allocate it and update the list. fixup_var_refs_insns will copy VAR
1875 or the SUBREG, as appropriate, to the pseudo. */
1878 fixup_var_refs_1 (var, promoted_mode, loc, insn, replacements)
1880 enum machine_mode promoted_mode;
1883 struct fixup_replacement **replacements;
1886 register rtx x = *loc;
1887 RTX_CODE code = GET_CODE (x);
1888 register const char *fmt;
1889 register rtx tem, tem1;
1890 struct fixup_replacement *replacement;
1895 if (XEXP (x, 0) == var)
1897 /* Prevent sharing of rtl that might lose. */
1898 rtx sub = copy_rtx (XEXP (var, 0));
1900 if (! validate_change (insn, loc, sub, 0))
1902 rtx y = gen_reg_rtx (GET_MODE (sub));
1905 /* We should be able to replace with a register or all is lost.
1906 Note that we can't use validate_change to verify this, since
1907 we're not caring for replacing all dups simultaneously. */
1908 if (! validate_replace_rtx (*loc, y, insn))
1911 /* Careful! First try to recognize a direct move of the
1912 value, mimicking how things are done in gen_reload wrt
1913 PLUS. Consider what happens when insn is a conditional
1914 move instruction and addsi3 clobbers flags. */
1917 new_insn = emit_insn (gen_rtx_SET (VOIDmode, y, sub));
1918 seq = gen_sequence ();
1921 if (recog_memoized (new_insn) < 0)
1923 /* That failed. Fall back on force_operand and hope. */
1926 force_operand (sub, y);
1927 seq = gen_sequence ();
1932 /* Don't separate setter from user. */
1933 if (PREV_INSN (insn) && sets_cc0_p (PREV_INSN (insn)))
1934 insn = PREV_INSN (insn);
1937 emit_insn_before (seq, insn);
1945 /* If we already have a replacement, use it. Otherwise,
1946 try to fix up this address in case it is invalid. */
1948 replacement = find_fixup_replacement (replacements, var);
1949 if (replacement->new)
1951 *loc = replacement->new;
1955 *loc = replacement->new = x = fixup_stack_1 (x, insn);
1957 /* Unless we are forcing memory to register or we changed the mode,
1958 we can leave things the way they are if the insn is valid. */
1960 INSN_CODE (insn) = -1;
1961 if (! flag_force_mem && GET_MODE (x) == promoted_mode
1962 && recog_memoized (insn) >= 0)
1965 *loc = replacement->new = gen_reg_rtx (promoted_mode);
1969 /* If X contains VAR, we need to unshare it here so that we update
1970 each occurrence separately. But all identical MEMs in one insn
1971 must be replaced with the same rtx because of the possibility of
1974 if (reg_mentioned_p (var, x))
1976 replacement = find_fixup_replacement (replacements, x);
1977 if (replacement->new == 0)
1978 replacement->new = copy_most_rtx (x, var);
1980 *loc = x = replacement->new;
1981 code = GET_CODE (x);
1997 /* Note that in some cases those types of expressions are altered
1998 by optimize_bit_field, and do not survive to get here. */
1999 if (XEXP (x, 0) == var
2000 || (GET_CODE (XEXP (x, 0)) == SUBREG
2001 && SUBREG_REG (XEXP (x, 0)) == var))
2003 /* Get TEM as a valid MEM in the mode presently in the insn.
2005 We don't worry about the possibility of MATCH_DUP here; it
2006 is highly unlikely and would be tricky to handle. */
2009 if (GET_CODE (tem) == SUBREG)
2011 if (GET_MODE_BITSIZE (GET_MODE (tem))
2012 > GET_MODE_BITSIZE (GET_MODE (var)))
2014 replacement = find_fixup_replacement (replacements, var);
2015 if (replacement->new == 0)
2016 replacement->new = gen_reg_rtx (GET_MODE (var));
2017 SUBREG_REG (tem) = replacement->new;
2019 /* The following code works only if we have a MEM, so we
2020 need to handle the subreg here. We directly substitute
2021 it assuming that a subreg must be OK here. We already
2022 scheduled a replacement to copy the mem into the
2028 tem = fixup_memory_subreg (tem, insn, 0);
2031 tem = fixup_stack_1 (tem, insn);
2033 /* Unless we want to load from memory, get TEM into the proper mode
2034 for an extract from memory. This can only be done if the
2035 extract is at a constant position and length. */
2037 if (! flag_force_mem && GET_CODE (XEXP (x, 1)) == CONST_INT
2038 && GET_CODE (XEXP (x, 2)) == CONST_INT
2039 && ! mode_dependent_address_p (XEXP (tem, 0))
2040 && ! MEM_VOLATILE_P (tem))
2042 enum machine_mode wanted_mode = VOIDmode;
2043 enum machine_mode is_mode = GET_MODE (tem);
2044 HOST_WIDE_INT pos = INTVAL (XEXP (x, 2));
2047 if (GET_CODE (x) == ZERO_EXTRACT)
2050 = insn_data[(int) CODE_FOR_extzv].operand[1].mode;
2051 if (wanted_mode == VOIDmode)
2052 wanted_mode = word_mode;
2056 if (GET_CODE (x) == SIGN_EXTRACT)
2058 wanted_mode = insn_data[(int) CODE_FOR_extv].operand[1].mode;
2059 if (wanted_mode == VOIDmode)
2060 wanted_mode = word_mode;
2063 /* If we have a narrower mode, we can do something. */
2064 if (wanted_mode != VOIDmode
2065 && GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
2067 HOST_WIDE_INT offset = pos / BITS_PER_UNIT;
2068 rtx old_pos = XEXP (x, 2);
2071 /* If the bytes and bits are counted differently, we
2072 must adjust the offset. */
2073 if (BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN)
2074 offset = (GET_MODE_SIZE (is_mode)
2075 - GET_MODE_SIZE (wanted_mode) - offset);
2077 pos %= GET_MODE_BITSIZE (wanted_mode);
2079 newmem = gen_rtx_MEM (wanted_mode,
2080 plus_constant (XEXP (tem, 0), offset));
2081 MEM_COPY_ATTRIBUTES (newmem, tem);
2083 /* Make the change and see if the insn remains valid. */
2084 INSN_CODE (insn) = -1;
2085 XEXP (x, 0) = newmem;
2086 XEXP (x, 2) = GEN_INT (pos);
2088 if (recog_memoized (insn) >= 0)
2091 /* Otherwise, restore old position. XEXP (x, 0) will be
2093 XEXP (x, 2) = old_pos;
2097 /* If we get here, the bitfield extract insn can't accept a memory
2098 reference. Copy the input into a register. */
2100 tem1 = gen_reg_rtx (GET_MODE (tem));
2101 emit_insn_before (gen_move_insn (tem1, tem), insn);
2108 if (SUBREG_REG (x) == var)
2110 /* If this is a special SUBREG made because VAR was promoted
2111 from a wider mode, replace it with VAR and call ourself
2112 recursively, this time saying that the object previously
2113 had its current mode (by virtue of the SUBREG). */
2115 if (SUBREG_PROMOTED_VAR_P (x))
2118 fixup_var_refs_1 (var, GET_MODE (var), loc, insn, replacements);
2122 /* If this SUBREG makes VAR wider, it has become a paradoxical
2123 SUBREG with VAR in memory, but these aren't allowed at this
2124 stage of the compilation. So load VAR into a pseudo and take
2125 a SUBREG of that pseudo. */
2126 if (GET_MODE_SIZE (GET_MODE (x)) > GET_MODE_SIZE (GET_MODE (var)))
2128 replacement = find_fixup_replacement (replacements, var);
2129 if (replacement->new == 0)
2130 replacement->new = gen_reg_rtx (GET_MODE (var));
2131 SUBREG_REG (x) = replacement->new;
2135 /* See if we have already found a replacement for this SUBREG.
2136 If so, use it. Otherwise, make a MEM and see if the insn
2137 is recognized. If not, or if we should force MEM into a register,
2138 make a pseudo for this SUBREG. */
2139 replacement = find_fixup_replacement (replacements, x);
2140 if (replacement->new)
2142 *loc = replacement->new;
2146 replacement->new = *loc = fixup_memory_subreg (x, insn, 0);
2148 INSN_CODE (insn) = -1;
2149 if (! flag_force_mem && recog_memoized (insn) >= 0)
2152 *loc = replacement->new = gen_reg_rtx (GET_MODE (x));
2158 /* First do special simplification of bit-field references. */
2159 if (GET_CODE (SET_DEST (x)) == SIGN_EXTRACT
2160 || GET_CODE (SET_DEST (x)) == ZERO_EXTRACT)
2161 optimize_bit_field (x, insn, 0);
2162 if (GET_CODE (SET_SRC (x)) == SIGN_EXTRACT
2163 || GET_CODE (SET_SRC (x)) == ZERO_EXTRACT)
2164 optimize_bit_field (x, insn, NULL_PTR);
2166 /* For a paradoxical SUBREG inside a ZERO_EXTRACT, load the object
2167 into a register and then store it back out. */
2168 if (GET_CODE (SET_DEST (x)) == ZERO_EXTRACT
2169 && GET_CODE (XEXP (SET_DEST (x), 0)) == SUBREG
2170 && SUBREG_REG (XEXP (SET_DEST (x), 0)) == var
2171 && (GET_MODE_SIZE (GET_MODE (XEXP (SET_DEST (x), 0)))
2172 > GET_MODE_SIZE (GET_MODE (var))))
2174 replacement = find_fixup_replacement (replacements, var);
2175 if (replacement->new == 0)
2176 replacement->new = gen_reg_rtx (GET_MODE (var));
2178 SUBREG_REG (XEXP (SET_DEST (x), 0)) = replacement->new;
2179 emit_insn_after (gen_move_insn (var, replacement->new), insn);
2182 /* If SET_DEST is now a paradoxical SUBREG, put the result of this
2183 insn into a pseudo and store the low part of the pseudo into VAR. */
2184 if (GET_CODE (SET_DEST (x)) == SUBREG
2185 && SUBREG_REG (SET_DEST (x)) == var
2186 && (GET_MODE_SIZE (GET_MODE (SET_DEST (x)))
2187 > GET_MODE_SIZE (GET_MODE (var))))
2189 SET_DEST (x) = tem = gen_reg_rtx (GET_MODE (SET_DEST (x)));
2190 emit_insn_after (gen_move_insn (var, gen_lowpart (GET_MODE (var),
2197 rtx dest = SET_DEST (x);
2198 rtx src = SET_SRC (x);
2200 rtx outerdest = dest;
2203 while (GET_CODE (dest) == SUBREG || GET_CODE (dest) == STRICT_LOW_PART
2204 || GET_CODE (dest) == SIGN_EXTRACT
2205 || GET_CODE (dest) == ZERO_EXTRACT)
2206 dest = XEXP (dest, 0);
2208 if (GET_CODE (src) == SUBREG)
2209 src = XEXP (src, 0);
2211 /* If VAR does not appear at the top level of the SET
2212 just scan the lower levels of the tree. */
2214 if (src != var && dest != var)
2217 /* We will need to rerecognize this insn. */
2218 INSN_CODE (insn) = -1;
2221 if (GET_CODE (outerdest) == ZERO_EXTRACT && dest == var)
2223 /* Since this case will return, ensure we fixup all the
2225 fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 1),
2226 insn, replacements);
2227 fixup_var_refs_1 (var, promoted_mode, &XEXP (outerdest, 2),
2228 insn, replacements);
2229 fixup_var_refs_1 (var, promoted_mode, &SET_SRC (x),
2230 insn, replacements);
2232 tem = XEXP (outerdest, 0);
2234 /* Clean up (SUBREG:SI (MEM:mode ...) 0)
2235 that may appear inside a ZERO_EXTRACT.
2236 This was legitimate when the MEM was a REG. */
2237 if (GET_CODE (tem) == SUBREG
2238 && SUBREG_REG (tem) == var)
2239 tem = fixup_memory_subreg (tem, insn, 0);
2241 tem = fixup_stack_1 (tem, insn);
2243 if (GET_CODE (XEXP (outerdest, 1)) == CONST_INT
2244 && GET_CODE (XEXP (outerdest, 2)) == CONST_INT
2245 && ! mode_dependent_address_p (XEXP (tem, 0))
2246 && ! MEM_VOLATILE_P (tem))
2248 enum machine_mode wanted_mode;
2249 enum machine_mode is_mode = GET_MODE (tem);
2250 HOST_WIDE_INT pos = INTVAL (XEXP (outerdest, 2));
2252 wanted_mode = insn_data[(int) CODE_FOR_insv].operand[0].mode;
2253 if (wanted_mode == VOIDmode)
2254 wanted_mode = word_mode;
2256 /* If we have a narrower mode, we can do something. */
2257 if (GET_MODE_SIZE (wanted_mode) < GET_MODE_SIZE (is_mode))
2259 HOST_WIDE_INT offset = pos / BITS_PER_UNIT;
2260 rtx old_pos = XEXP (outerdest, 2);
2263 if (BYTES_BIG_ENDIAN != BITS_BIG_ENDIAN)
2264 offset = (GET_MODE_SIZE (is_mode)
2265 - GET_MODE_SIZE (wanted_mode) - offset);
2267 pos %= GET_MODE_BITSIZE (wanted_mode);
2269 newmem = gen_rtx_MEM (wanted_mode,
2270 plus_constant (XEXP (tem, 0),
2272 MEM_COPY_ATTRIBUTES (newmem, tem);
2274 /* Make the change and see if the insn remains valid. */
2275 INSN_CODE (insn) = -1;
2276 XEXP (outerdest, 0) = newmem;
2277 XEXP (outerdest, 2) = GEN_INT (pos);
2279 if (recog_memoized (insn) >= 0)
2282 /* Otherwise, restore old position. XEXP (x, 0) will be
2284 XEXP (outerdest, 2) = old_pos;
2288 /* If we get here, the bit-field store doesn't allow memory
2289 or isn't located at a constant position. Load the value into
2290 a register, do the store, and put it back into memory. */
2292 tem1 = gen_reg_rtx (GET_MODE (tem));
2293 emit_insn_before (gen_move_insn (tem1, tem), insn);
2294 emit_insn_after (gen_move_insn (tem, tem1), insn);
2295 XEXP (outerdest, 0) = tem1;
2300 /* STRICT_LOW_PART is a no-op on memory references
2301 and it can cause combinations to be unrecognizable,
2304 if (dest == var && GET_CODE (SET_DEST (x)) == STRICT_LOW_PART)
2305 SET_DEST (x) = XEXP (SET_DEST (x), 0);
2307 /* A valid insn to copy VAR into or out of a register
2308 must be left alone, to avoid an infinite loop here.
2309 If the reference to VAR is by a subreg, fix that up,
2310 since SUBREG is not valid for a memref.
2311 Also fix up the address of the stack slot.
2313 Note that we must not try to recognize the insn until
2314 after we know that we have valid addresses and no
2315 (subreg (mem ...) ...) constructs, since these interfere
2316 with determining the validity of the insn. */
2318 if ((SET_SRC (x) == var
2319 || (GET_CODE (SET_SRC (x)) == SUBREG
2320 && SUBREG_REG (SET_SRC (x)) == var))
2321 && (GET_CODE (SET_DEST (x)) == REG
2322 || (GET_CODE (SET_DEST (x)) == SUBREG
2323 && GET_CODE (SUBREG_REG (SET_DEST (x))) == REG))
2324 && GET_MODE (var) == promoted_mode
2325 && x == single_set (insn))
2329 replacement = find_fixup_replacement (replacements, SET_SRC (x));
2330 if (replacement->new)
2331 SET_SRC (x) = replacement->new;
2332 else if (GET_CODE (SET_SRC (x)) == SUBREG)
2333 SET_SRC (x) = replacement->new
2334 = fixup_memory_subreg (SET_SRC (x), insn, 0);
2336 SET_SRC (x) = replacement->new
2337 = fixup_stack_1 (SET_SRC (x), insn);
2339 if (recog_memoized (insn) >= 0)
2342 /* INSN is not valid, but we know that we want to
2343 copy SET_SRC (x) to SET_DEST (x) in some way. So
2344 we generate the move and see whether it requires more
2345 than one insn. If it does, we emit those insns and
2346 delete INSN. Otherwise, we an just replace the pattern
2347 of INSN; we have already verified above that INSN has
2348 no other function that to do X. */
2350 pat = gen_move_insn (SET_DEST (x), SET_SRC (x));
2351 if (GET_CODE (pat) == SEQUENCE)
2353 last = emit_insn_before (pat, insn);
2355 /* INSN might have REG_RETVAL or other important notes, so
2356 we need to store the pattern of the last insn in the
2357 sequence into INSN similarly to the normal case. LAST
2358 should not have REG_NOTES, but we allow them if INSN has
2360 if (REG_NOTES (last) && REG_NOTES (insn))
2362 if (REG_NOTES (last))
2363 REG_NOTES (insn) = REG_NOTES (last);
2364 PATTERN (insn) = PATTERN (last);
2366 PUT_CODE (last, NOTE);
2367 NOTE_LINE_NUMBER (last) = NOTE_INSN_DELETED;
2368 NOTE_SOURCE_FILE (last) = 0;
2371 PATTERN (insn) = pat;
2376 if ((SET_DEST (x) == var
2377 || (GET_CODE (SET_DEST (x)) == SUBREG
2378 && SUBREG_REG (SET_DEST (x)) == var))
2379 && (GET_CODE (SET_SRC (x)) == REG
2380 || (GET_CODE (SET_SRC (x)) == SUBREG
2381 && GET_CODE (SUBREG_REG (SET_SRC (x))) == REG))
2382 && GET_MODE (var) == promoted_mode
2383 && x == single_set (insn))
2387 if (GET_CODE (SET_DEST (x)) == SUBREG)
2388 SET_DEST (x) = fixup_memory_subreg (SET_DEST (x), insn, 0);
2390 SET_DEST (x) = fixup_stack_1 (SET_DEST (x), insn);
2392 if (recog_memoized (insn) >= 0)
2395 pat = gen_move_insn (SET_DEST (x), SET_SRC (x));
2396 if (GET_CODE (pat) == SEQUENCE)
2398 last = emit_insn_before (pat, insn);
2400 /* INSN might have REG_RETVAL or other important notes, so
2401 we need to store the pattern of the last insn in the
2402 sequence into INSN similarly to the normal case. LAST
2403 should not have REG_NOTES, but we allow them if INSN has
2405 if (REG_NOTES (last) && REG_NOTES (insn))
2407 if (REG_NOTES (last))
2408 REG_NOTES (insn) = REG_NOTES (last);
2409 PATTERN (insn) = PATTERN (last);
2411 PUT_CODE (last, NOTE);
2412 NOTE_LINE_NUMBER (last) = NOTE_INSN_DELETED;
2413 NOTE_SOURCE_FILE (last) = 0;
2416 PATTERN (insn) = pat;
2421 /* Otherwise, storing into VAR must be handled specially
2422 by storing into a temporary and copying that into VAR
2423 with a new insn after this one. Note that this case
2424 will be used when storing into a promoted scalar since
2425 the insn will now have different modes on the input
2426 and output and hence will be invalid (except for the case
2427 of setting it to a constant, which does not need any
2428 change if it is valid). We generate extra code in that case,
2429 but combine.c will eliminate it. */
2434 rtx fixeddest = SET_DEST (x);
2436 /* STRICT_LOW_PART can be discarded, around a MEM. */
2437 if (GET_CODE (fixeddest) == STRICT_LOW_PART)
2438 fixeddest = XEXP (fixeddest, 0);
2439 /* Convert (SUBREG (MEM)) to a MEM in a changed mode. */
2440 if (GET_CODE (fixeddest) == SUBREG)
2442 fixeddest = fixup_memory_subreg (fixeddest, insn, 0);
2443 promoted_mode = GET_MODE (fixeddest);
2446 fixeddest = fixup_stack_1 (fixeddest, insn);
2448 temp = gen_reg_rtx (promoted_mode);
2450 emit_insn_after (gen_move_insn (fixeddest,
2451 gen_lowpart (GET_MODE (fixeddest),
2455 SET_DEST (x) = temp;
2463 /* Nothing special about this RTX; fix its operands. */
2465 fmt = GET_RTX_FORMAT (code);
2466 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2469 fixup_var_refs_1 (var, promoted_mode, &XEXP (x, i), insn, replacements);
2470 else if (fmt[i] == 'E')
2473 for (j = 0; j < XVECLEN (x, i); j++)
2474 fixup_var_refs_1 (var, promoted_mode, &XVECEXP (x, i, j),
2475 insn, replacements);
2480 /* Given X, an rtx of the form (SUBREG:m1 (MEM:m2 addr)),
2481 return an rtx (MEM:m1 newaddr) which is equivalent.
2482 If any insns must be emitted to compute NEWADDR, put them before INSN.
2484 UNCRITICAL nonzero means accept paradoxical subregs.
2485 This is used for subregs found inside REG_NOTES. */
2488 fixup_memory_subreg (x, insn, uncritical)
2493 int offset = SUBREG_WORD (x) * UNITS_PER_WORD;
2494 rtx addr = XEXP (SUBREG_REG (x), 0);
2495 enum machine_mode mode = GET_MODE (x);
2498 /* Paradoxical SUBREGs are usually invalid during RTL generation. */
2499 if (GET_MODE_SIZE (mode) > GET_MODE_SIZE (GET_MODE (SUBREG_REG (x)))
2503 if (BYTES_BIG_ENDIAN)
2504 offset += (MIN (UNITS_PER_WORD, GET_MODE_SIZE (GET_MODE (SUBREG_REG (x))))
2505 - MIN (UNITS_PER_WORD, GET_MODE_SIZE (mode)));
2506 addr = plus_constant (addr, offset);
2507 if (!flag_force_addr && memory_address_p (mode, addr))
2508 /* Shortcut if no insns need be emitted. */
2509 return change_address (SUBREG_REG (x), mode, addr);
2511 result = change_address (SUBREG_REG (x), mode, addr);
2512 emit_insn_before (gen_sequence (), insn);
2517 /* Do fixup_memory_subreg on all (SUBREG (MEM ...) ...) contained in X.
2518 Replace subexpressions of X in place.
2519 If X itself is a (SUBREG (MEM ...) ...), return the replacement expression.
2520 Otherwise return X, with its contents possibly altered.
2522 If any insns must be emitted to compute NEWADDR, put them before INSN.
2524 UNCRITICAL is as in fixup_memory_subreg. */
2527 walk_fixup_memory_subreg (x, insn, uncritical)
2532 register enum rtx_code code;
2533 register const char *fmt;
2539 code = GET_CODE (x);
2541 if (code == SUBREG && GET_CODE (SUBREG_REG (x)) == MEM)
2542 return fixup_memory_subreg (x, insn, uncritical);
2544 /* Nothing special about this RTX; fix its operands. */
2546 fmt = GET_RTX_FORMAT (code);
2547 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2550 XEXP (x, i) = walk_fixup_memory_subreg (XEXP (x, i), insn, uncritical);
2551 else if (fmt[i] == 'E')
2554 for (j = 0; j < XVECLEN (x, i); j++)
2556 = walk_fixup_memory_subreg (XVECEXP (x, i, j), insn, uncritical);
2562 /* For each memory ref within X, if it refers to a stack slot
2563 with an out of range displacement, put the address in a temp register
2564 (emitting new insns before INSN to load these registers)
2565 and alter the memory ref to use that register.
2566 Replace each such MEM rtx with a copy, to avoid clobberage. */
2569 fixup_stack_1 (x, insn)
2574 register RTX_CODE code = GET_CODE (x);
2575 register const char *fmt;
2579 register rtx ad = XEXP (x, 0);
2580 /* If we have address of a stack slot but it's not valid
2581 (displacement is too large), compute the sum in a register. */
2582 if (GET_CODE (ad) == PLUS
2583 && GET_CODE (XEXP (ad, 0)) == REG
2584 && ((REGNO (XEXP (ad, 0)) >= FIRST_VIRTUAL_REGISTER
2585 && REGNO (XEXP (ad, 0)) <= LAST_VIRTUAL_REGISTER)
2586 || REGNO (XEXP (ad, 0)) == FRAME_POINTER_REGNUM
2587 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
2588 || REGNO (XEXP (ad, 0)) == HARD_FRAME_POINTER_REGNUM
2590 || REGNO (XEXP (ad, 0)) == STACK_POINTER_REGNUM
2591 || REGNO (XEXP (ad, 0)) == ARG_POINTER_REGNUM
2592 || XEXP (ad, 0) == current_function_internal_arg_pointer)
2593 && GET_CODE (XEXP (ad, 1)) == CONST_INT)
2596 if (memory_address_p (GET_MODE (x), ad))
2600 temp = copy_to_reg (ad);
2601 seq = gen_sequence ();
2603 emit_insn_before (seq, insn);
2604 return change_address (x, VOIDmode, temp);
2609 fmt = GET_RTX_FORMAT (code);
2610 for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
2613 XEXP (x, i) = fixup_stack_1 (XEXP (x, i), insn);
2614 else if (fmt[i] == 'E')
2617 for (j = 0; j < XVECLEN (x, i); j++)
2618 XVECEXP (x, i, j) = fixup_stack_1 (XVECEXP (x, i, j), insn);
2624 /* Optimization: a bit-field instruction whose field
2625 happens to be a byte or halfword in memory
2626 can be changed to a move instruction.
2628 We call here when INSN is an insn to examine or store into a bit-field.
2629 BODY is the SET-rtx to be altered.
2631 EQUIV_MEM is the table `reg_equiv_mem' if that is available; else 0.
2632 (Currently this is called only from function.c, and EQUIV_MEM
2636 optimize_bit_field (body, insn, equiv_mem)
2641 register rtx bitfield;
2644 enum machine_mode mode;
2646 if (GET_CODE (SET_DEST (body)) == SIGN_EXTRACT
2647 || GET_CODE (SET_DEST (body)) == ZERO_EXTRACT)
2648 bitfield = SET_DEST (body), destflag = 1;
2650 bitfield = SET_SRC (body), destflag = 0;
2652 /* First check that the field being stored has constant size and position
2653 and is in fact a byte or halfword suitably aligned. */
2655 if (GET_CODE (XEXP (bitfield, 1)) == CONST_INT
2656 && GET_CODE (XEXP (bitfield, 2)) == CONST_INT
2657 && ((mode = mode_for_size (INTVAL (XEXP (bitfield, 1)), MODE_INT, 1))
2659 && INTVAL (XEXP (bitfield, 2)) % INTVAL (XEXP (bitfield, 1)) == 0)
2661 register rtx memref = 0;
2663 /* Now check that the containing word is memory, not a register,
2664 and that it is safe to change the machine mode. */
2666 if (GET_CODE (XEXP (bitfield, 0)) == MEM)
2667 memref = XEXP (bitfield, 0);
2668 else if (GET_CODE (XEXP (bitfield, 0)) == REG
2670 memref = equiv_mem[REGNO (XEXP (bitfield, 0))];
2671 else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
2672 && GET_CODE (SUBREG_REG (XEXP (bitfield, 0))) == MEM)
2673 memref = SUBREG_REG (XEXP (bitfield, 0));
2674 else if (GET_CODE (XEXP (bitfield, 0)) == SUBREG
2676 && GET_CODE (SUBREG_REG (XEXP (bitfield, 0))) == REG)
2677 memref = equiv_mem[REGNO (SUBREG_REG (XEXP (bitfield, 0)))];
2680 && ! mode_dependent_address_p (XEXP (memref, 0))
2681 && ! MEM_VOLATILE_P (memref))
2683 /* Now adjust the address, first for any subreg'ing
2684 that we are now getting rid of,
2685 and then for which byte of the word is wanted. */
2687 HOST_WIDE_INT offset = INTVAL (XEXP (bitfield, 2));
2690 /* Adjust OFFSET to count bits from low-address byte. */
2691 if (BITS_BIG_ENDIAN != BYTES_BIG_ENDIAN)
2692 offset = (GET_MODE_BITSIZE (GET_MODE (XEXP (bitfield, 0)))
2693 - offset - INTVAL (XEXP (bitfield, 1)));
2695 /* Adjust OFFSET to count bytes from low-address byte. */
2696 offset /= BITS_PER_UNIT;
2697 if (GET_CODE (XEXP (bitfield, 0)) == SUBREG)
2699 offset += SUBREG_WORD (XEXP (bitfield, 0)) * UNITS_PER_WORD;
2700 if (BYTES_BIG_ENDIAN)
2701 offset -= (MIN (UNITS_PER_WORD,
2702 GET_MODE_SIZE (GET_MODE (XEXP (bitfield, 0))))
2703 - MIN (UNITS_PER_WORD,
2704 GET_MODE_SIZE (GET_MODE (memref))));
2708 memref = change_address (memref, mode,
2709 plus_constant (XEXP (memref, 0), offset));
2710 insns = get_insns ();
2712 emit_insns_before (insns, insn);
2714 /* Store this memory reference where
2715 we found the bit field reference. */
2719 validate_change (insn, &SET_DEST (body), memref, 1);
2720 if (! CONSTANT_ADDRESS_P (SET_SRC (body)))
2722 rtx src = SET_SRC (body);
2723 while (GET_CODE (src) == SUBREG
2724 && SUBREG_WORD (src) == 0)
2725 src = SUBREG_REG (src);
2726 if (GET_MODE (src) != GET_MODE (memref))
2727 src = gen_lowpart (GET_MODE (memref), SET_SRC (body));
2728 validate_change (insn, &SET_SRC (body), src, 1);
2730 else if (GET_MODE (SET_SRC (body)) != VOIDmode
2731 && GET_MODE (SET_SRC (body)) != GET_MODE (memref))
2732 /* This shouldn't happen because anything that didn't have
2733 one of these modes should have got converted explicitly
2734 and then referenced through a subreg.
2735 This is so because the original bit-field was
2736 handled by agg_mode and so its tree structure had
2737 the same mode that memref now has. */
2742 rtx dest = SET_DEST (body);
2744 while (GET_CODE (dest) == SUBREG
2745 && SUBREG_WORD (dest) == 0
2746 && (GET_MODE_CLASS (GET_MODE (dest))
2747 == GET_MODE_CLASS (GET_MODE (SUBREG_REG (dest))))
2748 && (GET_MODE_SIZE (GET_MODE (SUBREG_REG (dest)))
2750 dest = SUBREG_REG (dest);
2752 validate_change (insn, &SET_DEST (body), dest, 1);
2754 if (GET_MODE (dest) == GET_MODE (memref))
2755 validate_change (insn, &SET_SRC (body), memref, 1);
2758 /* Convert the mem ref to the destination mode. */
2759 rtx newreg = gen_reg_rtx (GET_MODE (dest));
2762 convert_move (newreg, memref,
2763 GET_CODE (SET_SRC (body)) == ZERO_EXTRACT);
2767 validate_change (insn, &SET_SRC (body), newreg, 1);
2771 /* See if we can convert this extraction or insertion into
2772 a simple move insn. We might not be able to do so if this
2773 was, for example, part of a PARALLEL.
2775 If we succeed, write out any needed conversions. If we fail,
2776 it is hard to guess why we failed, so don't do anything
2777 special; just let the optimization be suppressed. */
2779 if (apply_change_group () && seq)
2780 emit_insns_before (seq, insn);
2785 /* These routines are responsible for converting virtual register references
2786 to the actual hard register references once RTL generation is complete.
2788 The following four variables are used for communication between the
2789 routines. They contain the offsets of the virtual registers from their
2790 respective hard registers. */
2792 static int in_arg_offset;
2793 static int var_offset;
2794 static int dynamic_offset;
2795 static int out_arg_offset;
2796 static int cfa_offset;
2798 /* In most machines, the stack pointer register is equivalent to the bottom
2801 #ifndef STACK_POINTER_OFFSET
2802 #define STACK_POINTER_OFFSET 0
2805 /* If not defined, pick an appropriate default for the offset of dynamically
2806 allocated memory depending on the value of ACCUMULATE_OUTGOING_ARGS,
2807 REG_PARM_STACK_SPACE, and OUTGOING_REG_PARM_STACK_SPACE. */
2809 #ifndef STACK_DYNAMIC_OFFSET
2811 /* The bottom of the stack points to the actual arguments. If
2812 REG_PARM_STACK_SPACE is defined, this includes the space for the register
2813 parameters. However, if OUTGOING_REG_PARM_STACK space is not defined,
2814 stack space for register parameters is not pushed by the caller, but
2815 rather part of the fixed stack areas and hence not included in
2816 `current_function_outgoing_args_size'. Nevertheless, we must allow
2817 for it when allocating stack dynamic objects. */
2819 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
2820 #define STACK_DYNAMIC_OFFSET(FNDECL) \
2821 ((ACCUMULATE_OUTGOING_ARGS \
2822 ? (current_function_outgoing_args_size + REG_PARM_STACK_SPACE (FNDECL)) : 0)\
2823 + (STACK_POINTER_OFFSET)) \
2826 #define STACK_DYNAMIC_OFFSET(FNDECL) \
2827 ((ACCUMULATE_OUTGOING_ARGS ? current_function_outgoing_args_size : 0) \
2828 + (STACK_POINTER_OFFSET))
2832 /* On most machines, the CFA coincides with the first incoming parm. */
2834 #ifndef ARG_POINTER_CFA_OFFSET
2835 #define ARG_POINTER_CFA_OFFSET(FNDECL) FIRST_PARM_OFFSET (FNDECL)
2838 /* Build up a (MEM (ADDRESSOF (REG))) rtx for a register REG that just had
2839 its address taken. DECL is the decl for the object stored in the
2840 register, for later use if we do need to force REG into the stack.
2841 REG is overwritten by the MEM like in put_reg_into_stack. */
2844 gen_mem_addressof (reg, decl)
2848 rtx r = gen_rtx_ADDRESSOF (Pmode, gen_reg_rtx (GET_MODE (reg)),
2851 /* If the original REG was a user-variable, then so is the REG whose
2852 address is being taken. Likewise for unchanging. */
2853 REG_USERVAR_P (XEXP (r, 0)) = REG_USERVAR_P (reg);
2854 RTX_UNCHANGING_P (XEXP (r, 0)) = RTX_UNCHANGING_P (reg);
2856 PUT_CODE (reg, MEM);
2860 tree type = TREE_TYPE (decl);
2862 PUT_MODE (reg, DECL_MODE (decl));
2863 MEM_VOLATILE_P (reg) = TREE_SIDE_EFFECTS (decl);
2864 MEM_SET_IN_STRUCT_P (reg, AGGREGATE_TYPE_P (type));
2865 MEM_ALIAS_SET (reg) = get_alias_set (decl);
2867 if (TREE_USED (decl) || DECL_INITIAL (decl) != 0)
2868 fixup_var_refs (reg, GET_MODE (reg), TREE_UNSIGNED (type), 0);
2872 /* We have no alias information about this newly created MEM. */
2873 MEM_ALIAS_SET (reg) = 0;
2875 fixup_var_refs (reg, GET_MODE (reg), 0, 0);
2881 /* If DECL has an RTL that is an ADDRESSOF rtx, put it into the stack. */
2884 flush_addressof (decl)
2887 if ((TREE_CODE (decl) == PARM_DECL || TREE_CODE (decl) == VAR_DECL)
2888 && DECL_RTL (decl) != 0
2889 && GET_CODE (DECL_RTL (decl)) == MEM
2890 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == ADDRESSOF
2891 && GET_CODE (XEXP (XEXP (DECL_RTL (decl), 0), 0)) == REG)
2892 put_addressof_into_stack (XEXP (DECL_RTL (decl), 0), 0);
2895 /* Force the register pointed to by R, an ADDRESSOF rtx, into the stack. */
2898 put_addressof_into_stack (r, ht)
2900 struct hash_table *ht;
2903 int volatile_p, used_p;
2905 rtx reg = XEXP (r, 0);
2907 if (GET_CODE (reg) != REG)
2910 decl = ADDRESSOF_DECL (r);
2913 type = TREE_TYPE (decl);
2914 volatile_p = (TREE_CODE (decl) != SAVE_EXPR
2915 && TREE_THIS_VOLATILE (decl));
2916 used_p = (TREE_USED (decl)
2917 || (TREE_CODE (decl) != SAVE_EXPR
2918 && DECL_INITIAL (decl) != 0));
2927 put_reg_into_stack (0, reg, type, GET_MODE (reg), GET_MODE (reg),
2928 volatile_p, ADDRESSOF_REGNO (r), used_p, ht);
2931 /* List of replacements made below in purge_addressof_1 when creating
2932 bitfield insertions. */
2933 static rtx purge_bitfield_addressof_replacements;
2935 /* List of replacements made below in purge_addressof_1 for patterns
2936 (MEM (ADDRESSOF (REG ...))). The key of the list entry is the
2937 corresponding (ADDRESSOF (REG ...)) and value is a substitution for
2938 the all pattern. List PURGE_BITFIELD_ADDRESSOF_REPLACEMENTS is not
2939 enough in complex cases, e.g. when some field values can be
2940 extracted by usage MEM with narrower mode. */
2941 static rtx purge_addressof_replacements;
2943 /* Helper function for purge_addressof. See if the rtx expression at *LOC
2944 in INSN needs to be changed. If FORCE, always put any ADDRESSOFs into
2945 the stack. If the function returns FALSE then the replacement could not
2949 purge_addressof_1 (loc, insn, force, store, ht)
2953 struct hash_table *ht;
2959 boolean result = true;
2961 /* Re-start here to avoid recursion in common cases. */
2968 code = GET_CODE (x);
2970 /* If we don't return in any of the cases below, we will recurse inside
2971 the RTX, which will normally result in any ADDRESSOF being forced into
2975 result = purge_addressof_1 (&SET_DEST (x), insn, force, 1, ht);
2976 result &= purge_addressof_1 (&SET_SRC (x), insn, force, 0, ht);
2980 else if (code == ADDRESSOF && GET_CODE (XEXP (x, 0)) == MEM)
2982 /* We must create a copy of the rtx because it was created by
2983 overwriting a REG rtx which is always shared. */
2984 rtx sub = copy_rtx (XEXP (XEXP (x, 0), 0));
2987 if (validate_change (insn, loc, sub, 0)
2988 || validate_replace_rtx (x, sub, insn))
2992 sub = force_operand (sub, NULL_RTX);
2993 if (! validate_change (insn, loc, sub, 0)
2994 && ! validate_replace_rtx (x, sub, insn))
2997 insns = gen_sequence ();
2999 emit_insn_before (insns, insn);
3003 else if (code == MEM && GET_CODE (XEXP (x, 0)) == ADDRESSOF && ! force)
3005 rtx sub = XEXP (XEXP (x, 0), 0);
3008 if (GET_CODE (sub) == MEM)
3010 sub2 = gen_rtx_MEM (GET_MODE (x), copy_rtx (XEXP (sub, 0)));
3011 MEM_COPY_ATTRIBUTES (sub2, sub);
3014 else if (GET_CODE (sub) == REG
3015 && (MEM_VOLATILE_P (x) || GET_MODE (x) == BLKmode))
3017 else if (GET_CODE (sub) == REG && GET_MODE (x) != GET_MODE (sub))
3019 int size_x, size_sub;
3023 /* When processing REG_NOTES look at the list of
3024 replacements done on the insn to find the register that X
3028 for (tem = purge_bitfield_addressof_replacements;
3030 tem = XEXP (XEXP (tem, 1), 1))
3031 if (rtx_equal_p (x, XEXP (tem, 0)))
3033 *loc = XEXP (XEXP (tem, 1), 0);
3037 /* See comment for purge_addressof_replacements. */
3038 for (tem = purge_addressof_replacements;
3040 tem = XEXP (XEXP (tem, 1), 1))
3041 if (rtx_equal_p (XEXP (x, 0), XEXP (tem, 0)))
3043 rtx z = XEXP (XEXP (tem, 1), 0);
3045 if (GET_MODE (x) == GET_MODE (z)
3046 || (GET_CODE (XEXP (XEXP (tem, 1), 0)) != REG
3047 && GET_CODE (XEXP (XEXP (tem, 1), 0)) != SUBREG))
3050 /* It can happen that the note may speak of things
3051 in a wider (or just different) mode than the
3052 code did. This is especially true of
3055 if (GET_CODE (z) == SUBREG && SUBREG_WORD (z) == 0)
3058 if (GET_MODE_SIZE (GET_MODE (x)) > UNITS_PER_WORD
3059 && (GET_MODE_SIZE (GET_MODE (x))
3060 > GET_MODE_SIZE (GET_MODE (z))))
3062 /* This can occur as a result in invalid
3063 pointer casts, e.g. float f; ...
3064 *(long long int *)&f.
3065 ??? We could emit a warning here, but
3066 without a line number that wouldn't be
3068 z = gen_rtx_SUBREG (GET_MODE (x), z, 0);
3071 z = gen_lowpart (GET_MODE (x), z);
3077 /* Sometimes we may not be able to find the replacement. For
3078 example when the original insn was a MEM in a wider mode,
3079 and the note is part of a sign extension of a narrowed
3080 version of that MEM. Gcc testcase compile/990829-1.c can
3081 generate an example of this siutation. Rather than complain
3082 we return false, which will prompt our caller to remove the
3087 size_x = GET_MODE_BITSIZE (GET_MODE (x));
3088 size_sub = GET_MODE_BITSIZE (GET_MODE (sub));
3090 /* Don't even consider working with paradoxical subregs,
3091 or the moral equivalent seen here. */
3092 if (size_x <= size_sub
3093 && int_mode_for_mode (GET_MODE (sub)) != BLKmode)
3095 /* Do a bitfield insertion to mirror what would happen
3102 rtx p = PREV_INSN (insn);
3105 val = gen_reg_rtx (GET_MODE (x));
3106 if (! validate_change (insn, loc, val, 0))
3108 /* Discard the current sequence and put the
3109 ADDRESSOF on stack. */
3113 seq = gen_sequence ();
3115 emit_insn_before (seq, insn);
3116 compute_insns_for_mem (p ? NEXT_INSN (p) : get_insns (),
3120 store_bit_field (sub, size_x, 0, GET_MODE (x),
3121 val, GET_MODE_SIZE (GET_MODE (sub)),
3122 GET_MODE_ALIGNMENT (GET_MODE (sub)));
3124 /* Make sure to unshare any shared rtl that store_bit_field
3125 might have created. */
3126 unshare_all_rtl_again (get_insns ());
3128 seq = gen_sequence ();
3130 p = emit_insn_after (seq, insn);
3131 if (NEXT_INSN (insn))
3132 compute_insns_for_mem (NEXT_INSN (insn),
3133 p ? NEXT_INSN (p) : NULL_RTX,
3138 rtx p = PREV_INSN (insn);
3141 val = extract_bit_field (sub, size_x, 0, 1, NULL_RTX,
3142 GET_MODE (x), GET_MODE (x),
3143 GET_MODE_SIZE (GET_MODE (sub)),
3144 GET_MODE_SIZE (GET_MODE (sub)));
3146 if (! validate_change (insn, loc, val, 0))
3148 /* Discard the current sequence and put the
3149 ADDRESSOF on stack. */
3154 seq = gen_sequence ();
3156 emit_insn_before (seq, insn);
3157 compute_insns_for_mem (p ? NEXT_INSN (p) : get_insns (),
3161 /* Remember the replacement so that the same one can be done
3162 on the REG_NOTES. */
3163 purge_bitfield_addressof_replacements
3164 = gen_rtx_EXPR_LIST (VOIDmode, x,
3167 purge_bitfield_addressof_replacements));
3169 /* We replaced with a reg -- all done. */
3174 else if (validate_change (insn, loc, sub, 0))
3176 /* Remember the replacement so that the same one can be done
3177 on the REG_NOTES. */
3178 if (GET_CODE (sub) == REG || GET_CODE (sub) == SUBREG)
3182 for (tem = purge_addressof_replacements;
3184 tem = XEXP (XEXP (tem, 1), 1))
3185 if (rtx_equal_p (XEXP (x, 0), XEXP (tem, 0)))
3187 XEXP (XEXP (tem, 1), 0) = sub;
3190 purge_addressof_replacements
3191 = gen_rtx (EXPR_LIST, VOIDmode, XEXP (x, 0),
3192 gen_rtx_EXPR_LIST (VOIDmode, sub,
3193 purge_addressof_replacements));
3199 /* else give up and put it into the stack */
3202 else if (code == ADDRESSOF)
3204 put_addressof_into_stack (x, ht);
3207 else if (code == SET)
3209 result = purge_addressof_1 (&SET_DEST (x), insn, force, 1, ht);
3210 result &= purge_addressof_1 (&SET_SRC (x), insn, force, 0, ht);
3214 /* Scan all subexpressions. */
3215 fmt = GET_RTX_FORMAT (code);
3216 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
3219 result &= purge_addressof_1 (&XEXP (x, i), insn, force, 0, ht);
3220 else if (*fmt == 'E')
3221 for (j = 0; j < XVECLEN (x, i); j++)
3222 result &= purge_addressof_1 (&XVECEXP (x, i, j), insn, force, 0, ht);
3228 /* Return a new hash table entry in HT. */
3230 static struct hash_entry *
3231 insns_for_mem_newfunc (he, ht, k)
3232 struct hash_entry *he;
3233 struct hash_table *ht;
3234 hash_table_key k ATTRIBUTE_UNUSED;
3236 struct insns_for_mem_entry *ifmhe;
3240 ifmhe = ((struct insns_for_mem_entry *)
3241 hash_allocate (ht, sizeof (struct insns_for_mem_entry)));
3242 ifmhe->insns = NULL_RTX;
3247 /* Return a hash value for K, a REG. */
3249 static unsigned long
3250 insns_for_mem_hash (k)
3253 /* K is really a RTX. Just use the address as the hash value. */
3254 return (unsigned long) k;
3257 /* Return non-zero if K1 and K2 (two REGs) are the same. */
3260 insns_for_mem_comp (k1, k2)
3267 struct insns_for_mem_walk_info {
3268 /* The hash table that we are using to record which INSNs use which
3270 struct hash_table *ht;
3272 /* The INSN we are currently proessing. */
3275 /* Zero if we are walking to find ADDRESSOFs, one if we are walking
3276 to find the insns that use the REGs in the ADDRESSOFs. */
3280 /* Called from compute_insns_for_mem via for_each_rtx. If R is a REG
3281 that might be used in an ADDRESSOF expression, record this INSN in
3282 the hash table given by DATA (which is really a pointer to an
3283 insns_for_mem_walk_info structure). */
3286 insns_for_mem_walk (r, data)
3290 struct insns_for_mem_walk_info *ifmwi
3291 = (struct insns_for_mem_walk_info *) data;
3293 if (ifmwi->pass == 0 && *r && GET_CODE (*r) == ADDRESSOF
3294 && GET_CODE (XEXP (*r, 0)) == REG)
3295 hash_lookup (ifmwi->ht, XEXP (*r, 0), /*create=*/1, /*copy=*/0);
3296 else if (ifmwi->pass == 1 && *r && GET_CODE (*r) == REG)
3298 /* Lookup this MEM in the hashtable, creating it if necessary. */
3299 struct insns_for_mem_entry *ifme
3300 = (struct insns_for_mem_entry *) hash_lookup (ifmwi->ht,
3305 /* If we have not already recorded this INSN, do so now. Since
3306 we process the INSNs in order, we know that if we have
3307 recorded it it must be at the front of the list. */
3308 if (ifme && (!ifme->insns || XEXP (ifme->insns, 0) != ifmwi->insn))
3310 /* We do the allocation on the same obstack as is used for
3311 the hash table since this memory will not be used once
3312 the hash table is deallocated. */
3313 push_obstacks (&ifmwi->ht->memory, &ifmwi->ht->memory);
3314 ifme->insns = gen_rtx_EXPR_LIST (VOIDmode, ifmwi->insn,
3323 /* Walk the INSNS, until we reach LAST_INSN, recording which INSNs use
3324 which REGs in HT. */
3327 compute_insns_for_mem (insns, last_insn, ht)
3330 struct hash_table *ht;
3333 struct insns_for_mem_walk_info ifmwi;
3336 for (ifmwi.pass = 0; ifmwi.pass < 2; ++ifmwi.pass)
3337 for (insn = insns; insn != last_insn; insn = NEXT_INSN (insn))
3341 for_each_rtx (&insn, insns_for_mem_walk, &ifmwi);
3345 /* Helper function for purge_addressof called through for_each_rtx.
3346 Returns true iff the rtl is an ADDRESSOF. */
3348 is_addressof (rtl, data)
3350 void *data ATTRIBUTE_UNUSED;
3352 return GET_CODE (*rtl) == ADDRESSOF;
3355 /* Eliminate all occurrences of ADDRESSOF from INSNS. Elide any remaining
3356 (MEM (ADDRESSOF)) patterns, and force any needed registers into the
3360 purge_addressof (insns)
3364 struct hash_table ht;
3366 /* When we actually purge ADDRESSOFs, we turn REGs into MEMs. That
3367 requires a fixup pass over the instruction stream to correct
3368 INSNs that depended on the REG being a REG, and not a MEM. But,
3369 these fixup passes are slow. Furthermore, most MEMs are not
3370 mentioned in very many instructions. So, we speed up the process
3371 by pre-calculating which REGs occur in which INSNs; that allows
3372 us to perform the fixup passes much more quickly. */
3373 hash_table_init (&ht,
3374 insns_for_mem_newfunc,
3376 insns_for_mem_comp);
3377 compute_insns_for_mem (insns, NULL_RTX, &ht);
3379 for (insn = insns; insn; insn = NEXT_INSN (insn))
3380 if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN
3381 || GET_CODE (insn) == CALL_INSN)
3383 if (! purge_addressof_1 (&PATTERN (insn), insn,
3384 asm_noperands (PATTERN (insn)) > 0, 0, &ht))
3385 /* If we could not replace the ADDRESSOFs in the insn,
3386 something is wrong. */
3389 if (! purge_addressof_1 (®_NOTES (insn), NULL_RTX, 0, 0, &ht))
3391 /* If we could not replace the ADDRESSOFs in the insn's notes,
3392 we can just remove the offending notes instead. */
3395 for (note = REG_NOTES (insn); note; note = XEXP (note, 1))
3397 /* If we find a REG_RETVAL note then the insn is a libcall.
3398 Such insns must have REG_EQUAL notes as well, in order
3399 for later passes of the compiler to work. So it is not
3400 safe to delete the notes here, and instead we abort. */
3401 if (REG_NOTE_KIND (note) == REG_RETVAL)
3403 if (for_each_rtx (¬e, is_addressof, NULL))
3404 remove_note (insn, note);
3410 hash_table_free (&ht);
3411 purge_bitfield_addressof_replacements = 0;
3412 purge_addressof_replacements = 0;
3414 /* REGs are shared. purge_addressof will destructively replace a REG
3415 with a MEM, which creates shared MEMs.
3417 Unfortunately, the children of put_reg_into_stack assume that MEMs
3418 referring to the same stack slot are shared (fixup_var_refs and
3419 the associated hash table code).
3421 So, we have to do another unsharing pass after we have flushed any
3422 REGs that had their address taken into the stack.
3424 It may be worth tracking whether or not we converted any REGs into
3425 MEMs to avoid this overhead when it is not needed. */
3426 unshare_all_rtl_again (get_insns ());
3429 /* Convert a SET of a hard subreg to a set of the appropriet hard
3430 register. A subroutine of purge_hard_subreg_sets. */
3433 purge_single_hard_subreg_set (pattern)
3436 rtx reg = SET_DEST (pattern);
3437 enum machine_mode mode = GET_MODE (SET_DEST (pattern));
3440 while (GET_CODE (reg) == SUBREG)
3442 word += SUBREG_WORD (reg);
3443 reg = SUBREG_REG (reg);
3446 if (REGNO (reg) < FIRST_PSEUDO_REGISTER)
3448 reg = gen_rtx_REG (mode, REGNO (reg) + word);
3449 SET_DEST (pattern) = reg;
3453 /* Eliminate all occurrences of SETs of hard subregs from INSNS. The
3454 only such SETs that we expect to see are those left in because
3455 integrate can't handle sets of parts of a return value register.
3457 We don't use alter_subreg because we only want to eliminate subregs
3458 of hard registers. */
3461 purge_hard_subreg_sets (insn)
3464 for (; insn; insn = NEXT_INSN (insn))
3468 rtx pattern = PATTERN (insn);
3469 switch (GET_CODE (pattern))
3472 if (GET_CODE (SET_DEST (pattern)) == SUBREG)
3473 purge_single_hard_subreg_set (pattern);
3478 for (j = XVECLEN (pattern, 0) - 1; j >= 0; j--)
3480 rtx inner_pattern = XVECEXP (pattern, 0, j);
3481 if (GET_CODE (inner_pattern) == SET
3482 && GET_CODE (SET_DEST (inner_pattern)) == SUBREG)
3483 purge_single_hard_subreg_set (inner_pattern);
3494 /* Pass through the INSNS of function FNDECL and convert virtual register
3495 references to hard register references. */
3498 instantiate_virtual_regs (fndecl, insns)
3505 /* Compute the offsets to use for this function. */
3506 in_arg_offset = FIRST_PARM_OFFSET (fndecl);
3507 var_offset = STARTING_FRAME_OFFSET;
3508 dynamic_offset = STACK_DYNAMIC_OFFSET (fndecl);
3509 out_arg_offset = STACK_POINTER_OFFSET;
3510 cfa_offset = ARG_POINTER_CFA_OFFSET (fndecl);
3512 /* Scan all variables and parameters of this function. For each that is
3513 in memory, instantiate all virtual registers if the result is a valid
3514 address. If not, we do it later. That will handle most uses of virtual
3515 regs on many machines. */
3516 instantiate_decls (fndecl, 1);
3518 /* Initialize recognition, indicating that volatile is OK. */
3521 /* Scan through all the insns, instantiating every virtual register still
3523 for (insn = insns; insn; insn = NEXT_INSN (insn))
3524 if (GET_CODE (insn) == INSN || GET_CODE (insn) == JUMP_INSN
3525 || GET_CODE (insn) == CALL_INSN)
3527 instantiate_virtual_regs_1 (&PATTERN (insn), insn, 1);
3528 instantiate_virtual_regs_1 (®_NOTES (insn), NULL_RTX, 0);
3531 /* Instantiate the stack slots for the parm registers, for later use in
3532 addressof elimination. */
3533 for (i = 0; i < max_parm_reg; ++i)
3534 if (parm_reg_stack_loc[i])
3535 instantiate_virtual_regs_1 (&parm_reg_stack_loc[i], NULL_RTX, 0);
3537 /* Now instantiate the remaining register equivalences for debugging info.
3538 These will not be valid addresses. */
3539 instantiate_decls (fndecl, 0);
3541 /* Indicate that, from now on, assign_stack_local should use
3542 frame_pointer_rtx. */
3543 virtuals_instantiated = 1;
3546 /* Scan all decls in FNDECL (both variables and parameters) and instantiate
3547 all virtual registers in their DECL_RTL's.
3549 If VALID_ONLY, do this only if the resulting address is still valid.
3550 Otherwise, always do it. */
3553 instantiate_decls (fndecl, valid_only)
3559 if (DECL_SAVED_INSNS (fndecl))
3560 /* When compiling an inline function, the obstack used for
3561 rtl allocation is the maybepermanent_obstack. Calling
3562 `resume_temporary_allocation' switches us back to that
3563 obstack while we process this function's parameters. */
3564 resume_temporary_allocation ();
3566 /* Process all parameters of the function. */
3567 for (decl = DECL_ARGUMENTS (fndecl); decl; decl = TREE_CHAIN (decl))
3569 HOST_WIDE_INT size = int_size_in_bytes (TREE_TYPE (decl));
3571 instantiate_decl (DECL_RTL (decl), size, valid_only);
3573 /* If the parameter was promoted, then the incoming RTL mode may be
3574 larger than the declared type size. We must use the larger of
3576 size = MAX (GET_MODE_SIZE (GET_MODE (DECL_INCOMING_RTL (decl))), size);
3577 instantiate_decl (DECL_INCOMING_RTL (decl), size, valid_only);
3580 /* Now process all variables defined in the function or its subblocks. */
3581 instantiate_decls_1 (DECL_INITIAL (fndecl), valid_only);
3583 if (DECL_INLINE (fndecl) || DECL_DEFER_OUTPUT (fndecl))
3585 /* Save all rtl allocated for this function by raising the
3586 high-water mark on the maybepermanent_obstack. */
3588 /* All further rtl allocation is now done in the current_obstack. */
3589 rtl_in_current_obstack ();
3593 /* Subroutine of instantiate_decls: Process all decls in the given
3594 BLOCK node and all its subblocks. */
3597 instantiate_decls_1 (let, valid_only)
3603 for (t = BLOCK_VARS (let); t; t = TREE_CHAIN (t))
3604 instantiate_decl (DECL_RTL (t), int_size_in_bytes (TREE_TYPE (t)),
3607 /* Process all subblocks. */
3608 for (t = BLOCK_SUBBLOCKS (let); t; t = TREE_CHAIN (t))
3609 instantiate_decls_1 (t, valid_only);
3612 /* Subroutine of the preceding procedures: Given RTL representing a
3613 decl and the size of the object, do any instantiation required.
3615 If VALID_ONLY is non-zero, it means that the RTL should only be
3616 changed if the new address is valid. */
3619 instantiate_decl (x, size, valid_only)
3624 enum machine_mode mode;
3627 /* If this is not a MEM, no need to do anything. Similarly if the
3628 address is a constant or a register that is not a virtual register. */
3630 if (x == 0 || GET_CODE (x) != MEM)
3634 if (CONSTANT_P (addr)
3635 || (GET_CODE (addr) == ADDRESSOF && GET_CODE (XEXP (addr, 0)) == REG)
3636 || (GET_CODE (addr) == REG
3637 && (REGNO (addr) < FIRST_VIRTUAL_REGISTER
3638 || REGNO (addr) > LAST_VIRTUAL_REGISTER)))
3641 /* If we should only do this if the address is valid, copy the address.
3642 We need to do this so we can undo any changes that might make the
3643 address invalid. This copy is unfortunate, but probably can't be
3647 addr = copy_rtx (addr);
3649 instantiate_virtual_regs_1 (&addr, NULL_RTX, 0);
3651 if (valid_only && size >= 0)
3653 unsigned HOST_WIDE_INT decl_size = size;
3655 /* Now verify that the resulting address is valid for every integer or
3656 floating-point mode up to and including SIZE bytes long. We do this
3657 since the object might be accessed in any mode and frame addresses
3660 for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT);
3661 mode != VOIDmode && GET_MODE_SIZE (mode) <= decl_size;
3662 mode = GET_MODE_WIDER_MODE (mode))
3663 if (! memory_address_p (mode, addr))
3666 for (mode = GET_CLASS_NARROWEST_MODE (MODE_FLOAT);
3667 mode != VOIDmode && GET_MODE_SIZE (mode) <= decl_size;
3668 mode = GET_MODE_WIDER_MODE (mode))
3669 if (! memory_address_p (mode, addr))
3673 /* Put back the address now that we have updated it and we either know
3674 it is valid or we don't care whether it is valid. */
3679 /* Given a pointer to a piece of rtx and an optional pointer to the
3680 containing object, instantiate any virtual registers present in it.
3682 If EXTRA_INSNS, we always do the replacement and generate
3683 any extra insns before OBJECT. If it zero, we do nothing if replacement
3686 Return 1 if we either had nothing to do or if we were able to do the
3687 needed replacement. Return 0 otherwise; we only return zero if
3688 EXTRA_INSNS is zero.
3690 We first try some simple transformations to avoid the creation of extra
3694 instantiate_virtual_regs_1 (loc, object, extra_insns)
3702 HOST_WIDE_INT offset = 0;
3708 /* Re-start here to avoid recursion in common cases. */
3715 code = GET_CODE (x);
3717 /* Check for some special cases. */
3734 /* We are allowed to set the virtual registers. This means that
3735 the actual register should receive the source minus the
3736 appropriate offset. This is used, for example, in the handling
3737 of non-local gotos. */
3738 if (SET_DEST (x) == virtual_incoming_args_rtx)
3739 new = arg_pointer_rtx, offset = -in_arg_offset;
3740 else if (SET_DEST (x) == virtual_stack_vars_rtx)
3741 new = frame_pointer_rtx, offset = -var_offset;
3742 else if (SET_DEST (x) == virtual_stack_dynamic_rtx)
3743 new = stack_pointer_rtx, offset = -dynamic_offset;
3744 else if (SET_DEST (x) == virtual_outgoing_args_rtx)
3745 new = stack_pointer_rtx, offset = -out_arg_offset;
3746 else if (SET_DEST (x) == virtual_cfa_rtx)
3747 new = arg_pointer_rtx, offset = -cfa_offset;
3751 rtx src = SET_SRC (x);
3753 instantiate_virtual_regs_1 (&src, NULL_RTX, 0);
3755 /* The only valid sources here are PLUS or REG. Just do
3756 the simplest possible thing to handle them. */
3757 if (GET_CODE (src) != REG && GET_CODE (src) != PLUS)
3761 if (GET_CODE (src) != REG)
3762 temp = force_operand (src, NULL_RTX);
3765 temp = force_operand (plus_constant (temp, offset), NULL_RTX);
3769 emit_insns_before (seq, object);
3772 if (! validate_change (object, &SET_SRC (x), temp, 0)
3779 instantiate_virtual_regs_1 (&SET_DEST (x), object, extra_insns);
3784 /* Handle special case of virtual register plus constant. */
3785 if (CONSTANT_P (XEXP (x, 1)))
3787 rtx old, new_offset;
3789 /* Check for (plus (plus VIRT foo) (const_int)) first. */
3790 if (GET_CODE (XEXP (x, 0)) == PLUS)
3792 rtx inner = XEXP (XEXP (x, 0), 0);
3794 if (inner == virtual_incoming_args_rtx)
3795 new = arg_pointer_rtx, offset = in_arg_offset;
3796 else if (inner == virtual_stack_vars_rtx)
3797 new = frame_pointer_rtx, offset = var_offset;
3798 else if (inner == virtual_stack_dynamic_rtx)
3799 new = stack_pointer_rtx, offset = dynamic_offset;
3800 else if (inner == virtual_outgoing_args_rtx)
3801 new = stack_pointer_rtx, offset = out_arg_offset;
3802 else if (inner == virtual_cfa_rtx)
3803 new = arg_pointer_rtx, offset = cfa_offset;
3810 instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 1), object,
3812 new = gen_rtx_PLUS (Pmode, new, XEXP (XEXP (x, 0), 1));
3815 else if (XEXP (x, 0) == virtual_incoming_args_rtx)
3816 new = arg_pointer_rtx, offset = in_arg_offset;
3817 else if (XEXP (x, 0) == virtual_stack_vars_rtx)
3818 new = frame_pointer_rtx, offset = var_offset;
3819 else if (XEXP (x, 0) == virtual_stack_dynamic_rtx)
3820 new = stack_pointer_rtx, offset = dynamic_offset;
3821 else if (XEXP (x, 0) == virtual_outgoing_args_rtx)
3822 new = stack_pointer_rtx, offset = out_arg_offset;
3823 else if (XEXP (x, 0) == virtual_cfa_rtx)
3824 new = arg_pointer_rtx, offset = cfa_offset;
3827 /* We know the second operand is a constant. Unless the
3828 first operand is a REG (which has been already checked),
3829 it needs to be checked. */
3830 if (GET_CODE (XEXP (x, 0)) != REG)
3838 new_offset = plus_constant (XEXP (x, 1), offset);
3840 /* If the new constant is zero, try to replace the sum with just
3842 if (new_offset == const0_rtx
3843 && validate_change (object, loc, new, 0))
3846 /* Next try to replace the register and new offset.
3847 There are two changes to validate here and we can't assume that
3848 in the case of old offset equals new just changing the register
3849 will yield a valid insn. In the interests of a little efficiency,
3850 however, we only call validate change once (we don't queue up the
3851 changes and then call apply_change_group). */
3855 ? ! validate_change (object, &XEXP (x, 0), new, 0)
3856 : (XEXP (x, 0) = new,
3857 ! validate_change (object, &XEXP (x, 1), new_offset, 0)))
3865 /* Otherwise copy the new constant into a register and replace
3866 constant with that register. */
3867 temp = gen_reg_rtx (Pmode);
3869 if (validate_change (object, &XEXP (x, 1), temp, 0))
3870 emit_insn_before (gen_move_insn (temp, new_offset), object);
3873 /* If that didn't work, replace this expression with a
3874 register containing the sum. */
3877 new = gen_rtx_PLUS (Pmode, new, new_offset);
3880 temp = force_operand (new, NULL_RTX);
3884 emit_insns_before (seq, object);
3885 if (! validate_change (object, loc, temp, 0)
3886 && ! validate_replace_rtx (x, temp, object))
3894 /* Fall through to generic two-operand expression case. */
3900 case DIV: case UDIV:
3901 case MOD: case UMOD:
3902 case AND: case IOR: case XOR:
3903 case ROTATERT: case ROTATE:
3904 case ASHIFTRT: case LSHIFTRT: case ASHIFT:
3906 case GE: case GT: case GEU: case GTU:
3907 case LE: case LT: case LEU: case LTU:
3908 if (XEXP (x, 1) && ! CONSTANT_P (XEXP (x, 1)))
3909 instantiate_virtual_regs_1 (&XEXP (x, 1), object, extra_insns);
3914 /* Most cases of MEM that convert to valid addresses have already been
3915 handled by our scan of decls. The only special handling we
3916 need here is to make a copy of the rtx to ensure it isn't being
3917 shared if we have to change it to a pseudo.
3919 If the rtx is a simple reference to an address via a virtual register,
3920 it can potentially be shared. In such cases, first try to make it
3921 a valid address, which can also be shared. Otherwise, copy it and
3924 First check for common cases that need no processing. These are
3925 usually due to instantiation already being done on a previous instance
3929 if (CONSTANT_ADDRESS_P (temp)
3930 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
3931 || temp == arg_pointer_rtx
3933 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
3934 || temp == hard_frame_pointer_rtx
3936 || temp == frame_pointer_rtx)
3939 if (GET_CODE (temp) == PLUS
3940 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
3941 && (XEXP (temp, 0) == frame_pointer_rtx
3942 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
3943 || XEXP (temp, 0) == hard_frame_pointer_rtx
3945 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
3946 || XEXP (temp, 0) == arg_pointer_rtx
3951 if (temp == virtual_stack_vars_rtx
3952 || temp == virtual_incoming_args_rtx
3953 || (GET_CODE (temp) == PLUS
3954 && CONSTANT_ADDRESS_P (XEXP (temp, 1))
3955 && (XEXP (temp, 0) == virtual_stack_vars_rtx
3956 || XEXP (temp, 0) == virtual_incoming_args_rtx)))
3958 /* This MEM may be shared. If the substitution can be done without
3959 the need to generate new pseudos, we want to do it in place
3960 so all copies of the shared rtx benefit. The call below will
3961 only make substitutions if the resulting address is still
3964 Note that we cannot pass X as the object in the recursive call
3965 since the insn being processed may not allow all valid
3966 addresses. However, if we were not passed on object, we can
3967 only modify X without copying it if X will have a valid
3970 ??? Also note that this can still lose if OBJECT is an insn that
3971 has less restrictions on an address that some other insn.
3972 In that case, we will modify the shared address. This case
3973 doesn't seem very likely, though. One case where this could
3974 happen is in the case of a USE or CLOBBER reference, but we
3975 take care of that below. */
3977 if (instantiate_virtual_regs_1 (&XEXP (x, 0),
3978 object ? object : x, 0))
3981 /* Otherwise make a copy and process that copy. We copy the entire
3982 RTL expression since it might be a PLUS which could also be
3984 *loc = x = copy_rtx (x);
3987 /* Fall through to generic unary operation case. */
3989 case STRICT_LOW_PART:
3991 case PRE_DEC: case PRE_INC: case POST_DEC: case POST_INC:
3992 case SIGN_EXTEND: case ZERO_EXTEND:
3993 case TRUNCATE: case FLOAT_EXTEND: case FLOAT_TRUNCATE:
3994 case FLOAT: case FIX:
3995 case UNSIGNED_FIX: case UNSIGNED_FLOAT:
3999 /* These case either have just one operand or we know that we need not
4000 check the rest of the operands. */
4006 /* If the operand is a MEM, see if the change is a valid MEM. If not,
4007 go ahead and make the invalid one, but do it to a copy. For a REG,
4008 just make the recursive call, since there's no chance of a problem. */
4010 if ((GET_CODE (XEXP (x, 0)) == MEM
4011 && instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 0), XEXP (x, 0),
4013 || (GET_CODE (XEXP (x, 0)) == REG
4014 && instantiate_virtual_regs_1 (&XEXP (x, 0), object, 0)))
4017 XEXP (x, 0) = copy_rtx (XEXP (x, 0));
4022 /* Try to replace with a PLUS. If that doesn't work, compute the sum
4023 in front of this insn and substitute the temporary. */
4024 if (x == virtual_incoming_args_rtx)
4025 new = arg_pointer_rtx, offset = in_arg_offset;
4026 else if (x == virtual_stack_vars_rtx)
4027 new = frame_pointer_rtx, offset = var_offset;
4028 else if (x == virtual_stack_dynamic_rtx)
4029 new = stack_pointer_rtx, offset = dynamic_offset;
4030 else if (x == virtual_outgoing_args_rtx)
4031 new = stack_pointer_rtx, offset = out_arg_offset;
4032 else if (x == virtual_cfa_rtx)
4033 new = arg_pointer_rtx, offset = cfa_offset;
4037 temp = plus_constant (new, offset);
4038 if (!validate_change (object, loc, temp, 0))
4044 temp = force_operand (temp, NULL_RTX);
4048 emit_insns_before (seq, object);
4049 if (! validate_change (object, loc, temp, 0)
4050 && ! validate_replace_rtx (x, temp, object))
4058 if (GET_CODE (XEXP (x, 0)) == REG)
4061 else if (GET_CODE (XEXP (x, 0)) == MEM)
4063 /* If we have a (addressof (mem ..)), do any instantiation inside
4064 since we know we'll be making the inside valid when we finally
4065 remove the ADDRESSOF. */
4066 instantiate_virtual_regs_1 (&XEXP (XEXP (x, 0), 0), NULL_RTX, 0);
4075 /* Scan all subexpressions. */
4076 fmt = GET_RTX_FORMAT (code);
4077 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
4080 if (!instantiate_virtual_regs_1 (&XEXP (x, i), object, extra_insns))
4083 else if (*fmt == 'E')
4084 for (j = 0; j < XVECLEN (x, i); j++)
4085 if (! instantiate_virtual_regs_1 (&XVECEXP (x, i, j), object,
4092 /* Optimization: assuming this function does not receive nonlocal gotos,
4093 delete the handlers for such, as well as the insns to establish
4094 and disestablish them. */
4100 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
4102 /* Delete the handler by turning off the flag that would
4103 prevent jump_optimize from deleting it.
4104 Also permit deletion of the nonlocal labels themselves
4105 if nothing local refers to them. */
4106 if (GET_CODE (insn) == CODE_LABEL)
4110 LABEL_PRESERVE_P (insn) = 0;
4112 /* Remove it from the nonlocal_label list, to avoid confusing
4114 for (t = nonlocal_labels, last_t = 0; t;
4115 last_t = t, t = TREE_CHAIN (t))
4116 if (DECL_RTL (TREE_VALUE (t)) == insn)
4121 nonlocal_labels = TREE_CHAIN (nonlocal_labels);
4123 TREE_CHAIN (last_t) = TREE_CHAIN (t);
4126 if (GET_CODE (insn) == INSN)
4130 for (t = nonlocal_goto_handler_slots; t != 0; t = XEXP (t, 1))
4131 if (reg_mentioned_p (t, PATTERN (insn)))
4137 || (nonlocal_goto_stack_level != 0
4138 && reg_mentioned_p (nonlocal_goto_stack_level,
4148 return max_parm_reg;
4151 /* Return the first insn following those generated by `assign_parms'. */
4154 get_first_nonparm_insn ()
4157 return NEXT_INSN (last_parm_insn);
4158 return get_insns ();
4161 /* Return the first NOTE_INSN_BLOCK_BEG note in the function.
4162 Crash if there is none. */
4165 get_first_block_beg ()
4167 register rtx searcher;
4168 register rtx insn = get_first_nonparm_insn ();
4170 for (searcher = insn; searcher; searcher = NEXT_INSN (searcher))
4171 if (GET_CODE (searcher) == NOTE
4172 && NOTE_LINE_NUMBER (searcher) == NOTE_INSN_BLOCK_BEG)
4175 abort (); /* Invalid call to this function. (See comments above.) */
4179 /* Return 1 if EXP is an aggregate type (or a value with aggregate type).
4180 This means a type for which function calls must pass an address to the
4181 function or get an address back from the function.
4182 EXP may be a type node or an expression (whose type is tested). */
4185 aggregate_value_p (exp)
4188 int i, regno, nregs;
4191 tree type = (TYPE_P (exp)) ? exp : TREE_TYPE (exp);
4193 if (TREE_CODE (type) == VOID_TYPE)
4195 if (RETURN_IN_MEMORY (type))
4197 /* Types that are TREE_ADDRESSABLE must be constructed in memory,
4198 and thus can't be returned in registers. */
4199 if (TREE_ADDRESSABLE (type))
4201 if (flag_pcc_struct_return && AGGREGATE_TYPE_P (type))
4203 /* Make sure we have suitable call-clobbered regs to return
4204 the value in; if not, we must return it in memory. */
4205 reg = hard_function_value (type, 0, 0);
4207 /* If we have something other than a REG (e.g. a PARALLEL), then assume
4209 if (GET_CODE (reg) != REG)
4212 regno = REGNO (reg);
4213 nregs = HARD_REGNO_NREGS (regno, TYPE_MODE (type));
4214 for (i = 0; i < nregs; i++)
4215 if (! call_used_regs[regno + i])
4220 /* Assign RTL expressions to the function's parameters.
4221 This may involve copying them into registers and using
4222 those registers as the RTL for them. */
4225 assign_parms (fndecl)
4229 register rtx entry_parm = 0;
4230 register rtx stack_parm = 0;
4231 CUMULATIVE_ARGS args_so_far;
4232 enum machine_mode promoted_mode, passed_mode;
4233 enum machine_mode nominal_mode, promoted_nominal_mode;
4235 /* Total space needed so far for args on the stack,
4236 given as a constant and a tree-expression. */
4237 struct args_size stack_args_size;
4238 tree fntype = TREE_TYPE (fndecl);
4239 tree fnargs = DECL_ARGUMENTS (fndecl);
4240 /* This is used for the arg pointer when referring to stack args. */
4241 rtx internal_arg_pointer;
4242 /* This is a dummy PARM_DECL that we used for the function result if
4243 the function returns a structure. */
4244 tree function_result_decl = 0;
4245 #ifdef SETUP_INCOMING_VARARGS
4246 int varargs_setup = 0;
4248 rtx conversion_insns = 0;
4249 struct args_size alignment_pad;
4251 /* Nonzero if the last arg is named `__builtin_va_alist',
4252 which is used on some machines for old-fashioned non-ANSI varargs.h;
4253 this should be stuck onto the stack as if it had arrived there. */
4255 = (current_function_varargs
4257 && (parm = tree_last (fnargs)) != 0
4259 && (! strcmp (IDENTIFIER_POINTER (DECL_NAME (parm)),
4260 "__builtin_va_alist")));
4262 /* Nonzero if function takes extra anonymous args.
4263 This means the last named arg must be on the stack
4264 right before the anonymous ones. */
4266 = (TYPE_ARG_TYPES (fntype) != 0
4267 && (TREE_VALUE (tree_last (TYPE_ARG_TYPES (fntype)))
4268 != void_type_node));
4270 current_function_stdarg = stdarg;
4272 /* If the reg that the virtual arg pointer will be translated into is
4273 not a fixed reg or is the stack pointer, make a copy of the virtual
4274 arg pointer, and address parms via the copy. The frame pointer is
4275 considered fixed even though it is not marked as such.
4277 The second time through, simply use ap to avoid generating rtx. */
4279 if ((ARG_POINTER_REGNUM == STACK_POINTER_REGNUM
4280 || ! (fixed_regs[ARG_POINTER_REGNUM]
4281 || ARG_POINTER_REGNUM == FRAME_POINTER_REGNUM)))
4282 internal_arg_pointer = copy_to_reg (virtual_incoming_args_rtx);
4284 internal_arg_pointer = virtual_incoming_args_rtx;
4285 current_function_internal_arg_pointer = internal_arg_pointer;
4287 stack_args_size.constant = 0;
4288 stack_args_size.var = 0;
4290 /* If struct value address is treated as the first argument, make it so. */
4291 if (aggregate_value_p (DECL_RESULT (fndecl))
4292 && ! current_function_returns_pcc_struct
4293 && struct_value_incoming_rtx == 0)
4295 tree type = build_pointer_type (TREE_TYPE (fntype));
4297 function_result_decl = build_decl (PARM_DECL, NULL_TREE, type);
4299 DECL_ARG_TYPE (function_result_decl) = type;
4300 TREE_CHAIN (function_result_decl) = fnargs;
4301 fnargs = function_result_decl;
4304 max_parm_reg = LAST_VIRTUAL_REGISTER + 1;
4305 parm_reg_stack_loc = (rtx *) xcalloc (max_parm_reg, sizeof (rtx));
4307 #ifdef INIT_CUMULATIVE_INCOMING_ARGS
4308 INIT_CUMULATIVE_INCOMING_ARGS (args_so_far, fntype, NULL_RTX);
4310 INIT_CUMULATIVE_ARGS (args_so_far, fntype, NULL_RTX, 0);
4313 /* We haven't yet found an argument that we must push and pretend the
4315 current_function_pretend_args_size = 0;
4317 for (parm = fnargs; parm; parm = TREE_CHAIN (parm))
4319 struct args_size stack_offset;
4320 struct args_size arg_size;
4321 int passed_pointer = 0;
4322 int did_conversion = 0;
4323 tree passed_type = DECL_ARG_TYPE (parm);
4324 tree nominal_type = TREE_TYPE (parm);
4327 /* Set LAST_NAMED if this is last named arg before some
4329 int last_named = ((TREE_CHAIN (parm) == 0
4330 || DECL_NAME (TREE_CHAIN (parm)) == 0)
4331 && (stdarg || current_function_varargs));
4332 /* Set NAMED_ARG if this arg should be treated as a named arg. For
4333 most machines, if this is a varargs/stdarg function, then we treat
4334 the last named arg as if it were anonymous too. */
4335 int named_arg = STRICT_ARGUMENT_NAMING ? 1 : ! last_named;
4337 if (TREE_TYPE (parm) == error_mark_node
4338 /* This can happen after weird syntax errors
4339 or if an enum type is defined among the parms. */
4340 || TREE_CODE (parm) != PARM_DECL
4341 || passed_type == NULL)
4343 DECL_INCOMING_RTL (parm) = DECL_RTL (parm)
4344 = gen_rtx_MEM (BLKmode, const0_rtx);
4345 TREE_USED (parm) = 1;
4349 /* For varargs.h function, save info about regs and stack space
4350 used by the individual args, not including the va_alist arg. */
4351 if (hide_last_arg && last_named)
4352 current_function_args_info = args_so_far;
4354 /* Find mode of arg as it is passed, and mode of arg
4355 as it should be during execution of this function. */
4356 passed_mode = TYPE_MODE (passed_type);
4357 nominal_mode = TYPE_MODE (nominal_type);
4359 /* If the parm's mode is VOID, its value doesn't matter,
4360 and avoid the usual things like emit_move_insn that could crash. */
4361 if (nominal_mode == VOIDmode)
4363 DECL_INCOMING_RTL (parm) = DECL_RTL (parm) = const0_rtx;
4367 /* If the parm is to be passed as a transparent union, use the
4368 type of the first field for the tests below. We have already
4369 verified that the modes are the same. */
4370 if (DECL_TRANSPARENT_UNION (parm)
4371 || (TREE_CODE (passed_type) == UNION_TYPE
4372 && TYPE_TRANSPARENT_UNION (passed_type)))
4373 passed_type = TREE_TYPE (TYPE_FIELDS (passed_type));
4375 /* See if this arg was passed by invisible reference. It is if
4376 it is an object whose size depends on the contents of the
4377 object itself or if the machine requires these objects be passed
4380 if ((TREE_CODE (TYPE_SIZE (passed_type)) != INTEGER_CST
4381 && contains_placeholder_p (TYPE_SIZE (passed_type)))
4382 || TREE_ADDRESSABLE (passed_type)
4383 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
4384 || FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, passed_mode,
4385 passed_type, named_arg)
4389 passed_type = nominal_type = build_pointer_type (passed_type);
4391 passed_mode = nominal_mode = Pmode;
4394 promoted_mode = passed_mode;
4396 #ifdef PROMOTE_FUNCTION_ARGS
4397 /* Compute the mode in which the arg is actually extended to. */
4398 unsignedp = TREE_UNSIGNED (passed_type);
4399 promoted_mode = promote_mode (passed_type, promoted_mode, &unsignedp, 1);
4402 /* Let machine desc say which reg (if any) the parm arrives in.
4403 0 means it arrives on the stack. */
4404 #ifdef FUNCTION_INCOMING_ARG
4405 entry_parm = FUNCTION_INCOMING_ARG (args_so_far, promoted_mode,
4406 passed_type, named_arg);
4408 entry_parm = FUNCTION_ARG (args_so_far, promoted_mode,
4409 passed_type, named_arg);
4412 if (entry_parm == 0)
4413 promoted_mode = passed_mode;
4415 #ifdef SETUP_INCOMING_VARARGS
4416 /* If this is the last named parameter, do any required setup for
4417 varargs or stdargs. We need to know about the case of this being an
4418 addressable type, in which case we skip the registers it
4419 would have arrived in.
4421 For stdargs, LAST_NAMED will be set for two parameters, the one that
4422 is actually the last named, and the dummy parameter. We only
4423 want to do this action once.
4425 Also, indicate when RTL generation is to be suppressed. */
4426 if (last_named && !varargs_setup)
4428 SETUP_INCOMING_VARARGS (args_so_far, promoted_mode, passed_type,
4429 current_function_pretend_args_size, 0);
4434 /* Determine parm's home in the stack,
4435 in case it arrives in the stack or we should pretend it did.
4437 Compute the stack position and rtx where the argument arrives
4440 There is one complexity here: If this was a parameter that would
4441 have been passed in registers, but wasn't only because it is
4442 __builtin_va_alist, we want locate_and_pad_parm to treat it as if
4443 it came in a register so that REG_PARM_STACK_SPACE isn't skipped.
4444 In this case, we call FUNCTION_ARG with NAMED set to 1 instead of
4445 0 as it was the previous time. */
4447 pretend_named = named_arg || PRETEND_OUTGOING_VARARGS_NAMED;
4448 locate_and_pad_parm (promoted_mode, passed_type,
4449 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4452 #ifdef FUNCTION_INCOMING_ARG
4453 FUNCTION_INCOMING_ARG (args_so_far, promoted_mode,
4455 pretend_named) != 0,
4457 FUNCTION_ARG (args_so_far, promoted_mode,
4459 pretend_named) != 0,
4462 fndecl, &stack_args_size, &stack_offset, &arg_size,
4466 rtx offset_rtx = ARGS_SIZE_RTX (stack_offset);
4468 if (offset_rtx == const0_rtx)
4469 stack_parm = gen_rtx_MEM (promoted_mode, internal_arg_pointer);
4471 stack_parm = gen_rtx_MEM (promoted_mode,
4472 gen_rtx_PLUS (Pmode,
4473 internal_arg_pointer,
4476 set_mem_attributes (stack_parm, parm, 1);
4479 /* If this parameter was passed both in registers and in the stack,
4480 use the copy on the stack. */
4481 if (MUST_PASS_IN_STACK (promoted_mode, passed_type))
4484 #ifdef FUNCTION_ARG_PARTIAL_NREGS
4485 /* If this parm was passed part in regs and part in memory,
4486 pretend it arrived entirely in memory
4487 by pushing the register-part onto the stack.
4489 In the special case of a DImode or DFmode that is split,
4490 we could put it together in a pseudoreg directly,
4491 but for now that's not worth bothering with. */
4495 int nregs = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, promoted_mode,
4496 passed_type, named_arg);
4500 current_function_pretend_args_size
4501 = (((nregs * UNITS_PER_WORD) + (PARM_BOUNDARY / BITS_PER_UNIT) - 1)
4502 / (PARM_BOUNDARY / BITS_PER_UNIT)
4503 * (PARM_BOUNDARY / BITS_PER_UNIT));
4505 /* Handle calls that pass values in multiple non-contiguous
4506 locations. The Irix 6 ABI has examples of this. */
4507 if (GET_CODE (entry_parm) == PARALLEL)
4508 emit_group_store (validize_mem (stack_parm), entry_parm,
4509 int_size_in_bytes (TREE_TYPE (parm)),
4510 TYPE_ALIGN (TREE_TYPE (parm)));
4513 move_block_from_reg (REGNO (entry_parm),
4514 validize_mem (stack_parm), nregs,
4515 int_size_in_bytes (TREE_TYPE (parm)));
4517 entry_parm = stack_parm;
4522 /* If we didn't decide this parm came in a register,
4523 by default it came on the stack. */
4524 if (entry_parm == 0)
4525 entry_parm = stack_parm;
4527 /* Record permanently how this parm was passed. */
4528 DECL_INCOMING_RTL (parm) = entry_parm;
4530 /* If there is actually space on the stack for this parm,
4531 count it in stack_args_size; otherwise set stack_parm to 0
4532 to indicate there is no preallocated stack slot for the parm. */
4534 if (entry_parm == stack_parm
4535 || (GET_CODE (entry_parm) == PARALLEL
4536 && XEXP (XVECEXP (entry_parm, 0, 0), 0) == NULL_RTX)
4537 #if defined (REG_PARM_STACK_SPACE) && ! defined (MAYBE_REG_PARM_STACK_SPACE)
4538 /* On some machines, even if a parm value arrives in a register
4539 there is still an (uninitialized) stack slot allocated for it.
4541 ??? When MAYBE_REG_PARM_STACK_SPACE is defined, we can't tell
4542 whether this parameter already has a stack slot allocated,
4543 because an arg block exists only if current_function_args_size
4544 is larger than some threshold, and we haven't calculated that
4545 yet. So, for now, we just assume that stack slots never exist
4547 || REG_PARM_STACK_SPACE (fndecl) > 0
4551 stack_args_size.constant += arg_size.constant;
4553 ADD_PARM_SIZE (stack_args_size, arg_size.var);
4556 /* No stack slot was pushed for this parm. */
4559 /* Update info on where next arg arrives in registers. */
4561 FUNCTION_ARG_ADVANCE (args_so_far, promoted_mode,
4562 passed_type, named_arg);
4564 /* If we can't trust the parm stack slot to be aligned enough
4565 for its ultimate type, don't use that slot after entry.
4566 We'll make another stack slot, if we need one. */
4568 unsigned int thisparm_boundary
4569 = FUNCTION_ARG_BOUNDARY (promoted_mode, passed_type);
4571 if (GET_MODE_ALIGNMENT (nominal_mode) > thisparm_boundary)
4575 /* If parm was passed in memory, and we need to convert it on entry,
4576 don't store it back in that same slot. */
4578 && nominal_mode != BLKmode && nominal_mode != passed_mode)
4581 /* ENTRY_PARM is an RTX for the parameter as it arrives,
4582 in the mode in which it arrives.
4583 STACK_PARM is an RTX for a stack slot where the parameter can live
4584 during the function (in case we want to put it there).
4585 STACK_PARM is 0 if no stack slot was pushed for it.
4587 Now output code if necessary to convert ENTRY_PARM to
4588 the type in which this function declares it,
4589 and store that result in an appropriate place,
4590 which may be a pseudo reg, may be STACK_PARM,
4591 or may be a local stack slot if STACK_PARM is 0.
4593 Set DECL_RTL to that place. */
4595 if (nominal_mode == BLKmode || GET_CODE (entry_parm) == PARALLEL)
4597 /* If a BLKmode arrives in registers, copy it to a stack slot.
4598 Handle calls that pass values in multiple non-contiguous
4599 locations. The Irix 6 ABI has examples of this. */
4600 if (GET_CODE (entry_parm) == REG
4601 || GET_CODE (entry_parm) == PARALLEL)
4604 = CEIL_ROUND (int_size_in_bytes (TREE_TYPE (parm)),
4607 /* Note that we will be storing an integral number of words.
4608 So we have to be careful to ensure that we allocate an
4609 integral number of words. We do this below in the
4610 assign_stack_local if space was not allocated in the argument
4611 list. If it was, this will not work if PARM_BOUNDARY is not
4612 a multiple of BITS_PER_WORD. It isn't clear how to fix this
4613 if it becomes a problem. */
4615 if (stack_parm == 0)
4618 = assign_stack_local (GET_MODE (entry_parm),
4620 set_mem_attributes (stack_parm, parm, 1);
4623 else if (PARM_BOUNDARY % BITS_PER_WORD != 0)
4626 /* Handle calls that pass values in multiple non-contiguous
4627 locations. The Irix 6 ABI has examples of this. */
4628 if (GET_CODE (entry_parm) == PARALLEL)
4629 emit_group_store (validize_mem (stack_parm), entry_parm,
4630 int_size_in_bytes (TREE_TYPE (parm)),
4631 TYPE_ALIGN (TREE_TYPE (parm)));
4633 move_block_from_reg (REGNO (entry_parm),
4634 validize_mem (stack_parm),
4635 size_stored / UNITS_PER_WORD,
4636 int_size_in_bytes (TREE_TYPE (parm)));
4638 DECL_RTL (parm) = stack_parm;
4640 else if (! ((! optimize
4641 && ! DECL_REGISTER (parm)
4642 && ! DECL_INLINE (fndecl))
4643 /* layout_decl may set this. */
4644 || TREE_ADDRESSABLE (parm)
4645 || TREE_SIDE_EFFECTS (parm)
4646 /* If -ffloat-store specified, don't put explicit
4647 float variables into registers. */
4648 || (flag_float_store
4649 && TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE))
4650 /* Always assign pseudo to structure return or item passed
4651 by invisible reference. */
4652 || passed_pointer || parm == function_result_decl)
4654 /* Store the parm in a pseudoregister during the function, but we
4655 may need to do it in a wider mode. */
4657 register rtx parmreg;
4658 unsigned int regno, regnoi = 0, regnor = 0;
4660 unsignedp = TREE_UNSIGNED (TREE_TYPE (parm));
4662 promoted_nominal_mode
4663 = promote_mode (TREE_TYPE (parm), nominal_mode, &unsignedp, 0);
4665 parmreg = gen_reg_rtx (promoted_nominal_mode);
4666 mark_user_reg (parmreg);
4668 /* If this was an item that we received a pointer to, set DECL_RTL
4673 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (passed_type)), parmreg);
4674 set_mem_attributes (DECL_RTL (parm), parm, 1);
4677 DECL_RTL (parm) = parmreg;
4679 /* Copy the value into the register. */
4680 if (nominal_mode != passed_mode
4681 || promoted_nominal_mode != promoted_mode)
4684 /* ENTRY_PARM has been converted to PROMOTED_MODE, its
4685 mode, by the caller. We now have to convert it to
4686 NOMINAL_MODE, if different. However, PARMREG may be in
4687 a different mode than NOMINAL_MODE if it is being stored
4690 If ENTRY_PARM is a hard register, it might be in a register
4691 not valid for operating in its mode (e.g., an odd-numbered
4692 register for a DFmode). In that case, moves are the only
4693 thing valid, so we can't do a convert from there. This
4694 occurs when the calling sequence allow such misaligned
4697 In addition, the conversion may involve a call, which could
4698 clobber parameters which haven't been copied to pseudo
4699 registers yet. Therefore, we must first copy the parm to
4700 a pseudo reg here, and save the conversion until after all
4701 parameters have been moved. */
4703 rtx tempreg = gen_reg_rtx (GET_MODE (entry_parm));
4705 emit_move_insn (tempreg, validize_mem (entry_parm));
4707 push_to_sequence (conversion_insns);
4708 tempreg = convert_to_mode (nominal_mode, tempreg, unsignedp);
4710 /* TREE_USED gets set erroneously during expand_assignment. */
4711 save_tree_used = TREE_USED (parm);
4712 expand_assignment (parm,
4713 make_tree (nominal_type, tempreg), 0, 0);
4714 TREE_USED (parm) = save_tree_used;
4715 conversion_insns = get_insns ();
4720 emit_move_insn (parmreg, validize_mem (entry_parm));
4722 /* If we were passed a pointer but the actual value
4723 can safely live in a register, put it in one. */
4724 if (passed_pointer && TYPE_MODE (TREE_TYPE (parm)) != BLKmode
4726 && ! DECL_REGISTER (parm)
4727 && ! DECL_INLINE (fndecl))
4728 /* layout_decl may set this. */
4729 || TREE_ADDRESSABLE (parm)
4730 || TREE_SIDE_EFFECTS (parm)
4731 /* If -ffloat-store specified, don't put explicit
4732 float variables into registers. */
4733 || (flag_float_store
4734 && TREE_CODE (TREE_TYPE (parm)) == REAL_TYPE)))
4736 /* We can't use nominal_mode, because it will have been set to
4737 Pmode above. We must use the actual mode of the parm. */
4738 parmreg = gen_reg_rtx (TYPE_MODE (TREE_TYPE (parm)));
4739 mark_user_reg (parmreg);
4740 emit_move_insn (parmreg, DECL_RTL (parm));
4741 DECL_RTL (parm) = parmreg;
4742 /* STACK_PARM is the pointer, not the parm, and PARMREG is
4746 #ifdef FUNCTION_ARG_CALLEE_COPIES
4747 /* If we are passed an arg by reference and it is our responsibility
4748 to make a copy, do it now.
4749 PASSED_TYPE and PASSED mode now refer to the pointer, not the
4750 original argument, so we must recreate them in the call to
4751 FUNCTION_ARG_CALLEE_COPIES. */
4752 /* ??? Later add code to handle the case that if the argument isn't
4753 modified, don't do the copy. */
4755 else if (passed_pointer
4756 && FUNCTION_ARG_CALLEE_COPIES (args_so_far,
4757 TYPE_MODE (DECL_ARG_TYPE (parm)),
4758 DECL_ARG_TYPE (parm),
4760 && ! TREE_ADDRESSABLE (DECL_ARG_TYPE (parm)))
4763 tree type = DECL_ARG_TYPE (parm);
4765 /* This sequence may involve a library call perhaps clobbering
4766 registers that haven't been copied to pseudos yet. */
4768 push_to_sequence (conversion_insns);
4770 if (!COMPLETE_TYPE_P (type)
4771 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4772 /* This is a variable sized object. */
4773 copy = gen_rtx_MEM (BLKmode,
4774 allocate_dynamic_stack_space
4775 (expr_size (parm), NULL_RTX,
4776 TYPE_ALIGN (type)));
4778 copy = assign_stack_temp (TYPE_MODE (type),
4779 int_size_in_bytes (type), 1);
4780 set_mem_attributes (copy, parm, 1);
4782 store_expr (parm, copy, 0);
4783 emit_move_insn (parmreg, XEXP (copy, 0));
4784 if (current_function_check_memory_usage)
4785 emit_library_call (chkr_set_right_libfunc,
4786 LCT_CONST_MAKE_BLOCK, VOIDmode, 3,
4787 XEXP (copy, 0), Pmode,
4788 GEN_INT (int_size_in_bytes (type)),
4789 TYPE_MODE (sizetype),
4790 GEN_INT (MEMORY_USE_RW),
4791 TYPE_MODE (integer_type_node));
4792 conversion_insns = get_insns ();
4796 #endif /* FUNCTION_ARG_CALLEE_COPIES */
4798 /* In any case, record the parm's desired stack location
4799 in case we later discover it must live in the stack.
4801 If it is a COMPLEX value, store the stack location for both
4804 if (GET_CODE (parmreg) == CONCAT)
4805 regno = MAX (REGNO (XEXP (parmreg, 0)), REGNO (XEXP (parmreg, 1)));
4807 regno = REGNO (parmreg);
4809 if (regno >= max_parm_reg)
4812 int old_max_parm_reg = max_parm_reg;
4814 /* It's slow to expand this one register at a time,
4815 but it's also rare and we need max_parm_reg to be
4816 precisely correct. */
4817 max_parm_reg = regno + 1;
4818 new = (rtx *) xrealloc (parm_reg_stack_loc,
4819 max_parm_reg * sizeof (rtx));
4820 bzero ((char *) (new + old_max_parm_reg),
4821 (max_parm_reg - old_max_parm_reg) * sizeof (rtx));
4822 parm_reg_stack_loc = new;
4825 if (GET_CODE (parmreg) == CONCAT)
4827 enum machine_mode submode = GET_MODE (XEXP (parmreg, 0));
4829 regnor = REGNO (gen_realpart (submode, parmreg));
4830 regnoi = REGNO (gen_imagpart (submode, parmreg));
4832 if (stack_parm != 0)
4834 parm_reg_stack_loc[regnor]
4835 = gen_realpart (submode, stack_parm);
4836 parm_reg_stack_loc[regnoi]
4837 = gen_imagpart (submode, stack_parm);
4841 parm_reg_stack_loc[regnor] = 0;
4842 parm_reg_stack_loc[regnoi] = 0;
4846 parm_reg_stack_loc[REGNO (parmreg)] = stack_parm;
4848 /* Mark the register as eliminable if we did no conversion
4849 and it was copied from memory at a fixed offset,
4850 and the arg pointer was not copied to a pseudo-reg.
4851 If the arg pointer is a pseudo reg or the offset formed
4852 an invalid address, such memory-equivalences
4853 as we make here would screw up life analysis for it. */
4854 if (nominal_mode == passed_mode
4857 && GET_CODE (stack_parm) == MEM
4858 && stack_offset.var == 0
4859 && reg_mentioned_p (virtual_incoming_args_rtx,
4860 XEXP (stack_parm, 0)))
4862 rtx linsn = get_last_insn ();
4865 /* Mark complex types separately. */
4866 if (GET_CODE (parmreg) == CONCAT)
4867 /* Scan backwards for the set of the real and
4869 for (sinsn = linsn; sinsn != 0;
4870 sinsn = prev_nonnote_insn (sinsn))
4872 set = single_set (sinsn);
4874 && SET_DEST (set) == regno_reg_rtx [regnoi])
4876 = gen_rtx_EXPR_LIST (REG_EQUIV,
4877 parm_reg_stack_loc[regnoi],
4880 && SET_DEST (set) == regno_reg_rtx [regnor])
4882 = gen_rtx_EXPR_LIST (REG_EQUIV,
4883 parm_reg_stack_loc[regnor],
4886 else if ((set = single_set (linsn)) != 0
4887 && SET_DEST (set) == parmreg)
4889 = gen_rtx_EXPR_LIST (REG_EQUIV,
4890 stack_parm, REG_NOTES (linsn));
4893 /* For pointer data type, suggest pointer register. */
4894 if (POINTER_TYPE_P (TREE_TYPE (parm)))
4895 mark_reg_pointer (parmreg,
4896 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (parm))));
4901 /* Value must be stored in the stack slot STACK_PARM
4902 during function execution. */
4904 if (promoted_mode != nominal_mode)
4906 /* Conversion is required. */
4907 rtx tempreg = gen_reg_rtx (GET_MODE (entry_parm));
4909 emit_move_insn (tempreg, validize_mem (entry_parm));
4911 push_to_sequence (conversion_insns);
4912 entry_parm = convert_to_mode (nominal_mode, tempreg,
4913 TREE_UNSIGNED (TREE_TYPE (parm)));
4916 /* ??? This may need a big-endian conversion on sparc64. */
4917 stack_parm = change_address (stack_parm, nominal_mode,
4920 conversion_insns = get_insns ();
4925 if (entry_parm != stack_parm)
4927 if (stack_parm == 0)
4930 = assign_stack_local (GET_MODE (entry_parm),
4931 GET_MODE_SIZE (GET_MODE (entry_parm)), 0);
4932 set_mem_attributes (stack_parm, parm, 1);
4935 if (promoted_mode != nominal_mode)
4937 push_to_sequence (conversion_insns);
4938 emit_move_insn (validize_mem (stack_parm),
4939 validize_mem (entry_parm));
4940 conversion_insns = get_insns ();
4944 emit_move_insn (validize_mem (stack_parm),
4945 validize_mem (entry_parm));
4947 if (current_function_check_memory_usage)
4949 push_to_sequence (conversion_insns);
4950 emit_library_call (chkr_set_right_libfunc, LCT_CONST_MAKE_BLOCK,
4951 VOIDmode, 3, XEXP (stack_parm, 0), Pmode,
4952 GEN_INT (GET_MODE_SIZE (GET_MODE
4954 TYPE_MODE (sizetype),
4955 GEN_INT (MEMORY_USE_RW),
4956 TYPE_MODE (integer_type_node));
4958 conversion_insns = get_insns ();
4961 DECL_RTL (parm) = stack_parm;
4964 /* If this "parameter" was the place where we are receiving the
4965 function's incoming structure pointer, set up the result. */
4966 if (parm == function_result_decl)
4968 tree result = DECL_RESULT (fndecl);
4971 = gen_rtx_MEM (DECL_MODE (result), DECL_RTL (parm));
4973 set_mem_attributes (DECL_RTL (result), result, 1);
4977 /* Output all parameter conversion instructions (possibly including calls)
4978 now that all parameters have been copied out of hard registers. */
4979 emit_insns (conversion_insns);
4981 last_parm_insn = get_last_insn ();
4983 current_function_args_size = stack_args_size.constant;
4985 /* Adjust function incoming argument size for alignment and
4988 #ifdef REG_PARM_STACK_SPACE
4989 #ifndef MAYBE_REG_PARM_STACK_SPACE
4990 current_function_args_size = MAX (current_function_args_size,
4991 REG_PARM_STACK_SPACE (fndecl));
4995 #ifdef STACK_BOUNDARY
4996 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
4998 current_function_args_size
4999 = ((current_function_args_size + STACK_BYTES - 1)
5000 / STACK_BYTES) * STACK_BYTES;
5003 #ifdef ARGS_GROW_DOWNWARD
5004 current_function_arg_offset_rtx
5005 = (stack_args_size.var == 0 ? GEN_INT (-stack_args_size.constant)
5006 : expand_expr (size_diffop (stack_args_size.var,
5007 size_int (-stack_args_size.constant)),
5008 NULL_RTX, VOIDmode, EXPAND_MEMORY_USE_BAD));
5010 current_function_arg_offset_rtx = ARGS_SIZE_RTX (stack_args_size);
5013 /* See how many bytes, if any, of its args a function should try to pop
5016 current_function_pops_args = RETURN_POPS_ARGS (fndecl, TREE_TYPE (fndecl),
5017 current_function_args_size);
5019 /* For stdarg.h function, save info about
5020 regs and stack space used by the named args. */
5023 current_function_args_info = args_so_far;
5025 /* Set the rtx used for the function return value. Put this in its
5026 own variable so any optimizers that need this information don't have
5027 to include tree.h. Do this here so it gets done when an inlined
5028 function gets output. */
5030 current_function_return_rtx = DECL_RTL (DECL_RESULT (fndecl));
5033 /* Indicate whether REGNO is an incoming argument to the current function
5034 that was promoted to a wider mode. If so, return the RTX for the
5035 register (to get its mode). PMODE and PUNSIGNEDP are set to the mode
5036 that REGNO is promoted from and whether the promotion was signed or
5039 #ifdef PROMOTE_FUNCTION_ARGS
5042 promoted_input_arg (regno, pmode, punsignedp)
5044 enum machine_mode *pmode;
5049 for (arg = DECL_ARGUMENTS (current_function_decl); arg;
5050 arg = TREE_CHAIN (arg))
5051 if (GET_CODE (DECL_INCOMING_RTL (arg)) == REG
5052 && REGNO (DECL_INCOMING_RTL (arg)) == regno
5053 && TYPE_MODE (DECL_ARG_TYPE (arg)) == TYPE_MODE (TREE_TYPE (arg)))
5055 enum machine_mode mode = TYPE_MODE (TREE_TYPE (arg));
5056 int unsignedp = TREE_UNSIGNED (TREE_TYPE (arg));
5058 mode = promote_mode (TREE_TYPE (arg), mode, &unsignedp, 1);
5059 if (mode == GET_MODE (DECL_INCOMING_RTL (arg))
5060 && mode != DECL_MODE (arg))
5062 *pmode = DECL_MODE (arg);
5063 *punsignedp = unsignedp;
5064 return DECL_INCOMING_RTL (arg);
5073 /* Compute the size and offset from the start of the stacked arguments for a
5074 parm passed in mode PASSED_MODE and with type TYPE.
5076 INITIAL_OFFSET_PTR points to the current offset into the stacked
5079 The starting offset and size for this parm are returned in *OFFSET_PTR
5080 and *ARG_SIZE_PTR, respectively.
5082 IN_REGS is non-zero if the argument will be passed in registers. It will
5083 never be set if REG_PARM_STACK_SPACE is not defined.
5085 FNDECL is the function in which the argument was defined.
5087 There are two types of rounding that are done. The first, controlled by
5088 FUNCTION_ARG_BOUNDARY, forces the offset from the start of the argument
5089 list to be aligned to the specific boundary (in bits). This rounding
5090 affects the initial and starting offsets, but not the argument size.
5092 The second, controlled by FUNCTION_ARG_PADDING and PARM_BOUNDARY,
5093 optionally rounds the size of the parm to PARM_BOUNDARY. The
5094 initial offset is not affected by this rounding, while the size always
5095 is and the starting offset may be. */
5097 /* offset_ptr will be negative for ARGS_GROW_DOWNWARD case;
5098 initial_offset_ptr is positive because locate_and_pad_parm's
5099 callers pass in the total size of args so far as
5100 initial_offset_ptr. arg_size_ptr is always positive.*/
5103 locate_and_pad_parm (passed_mode, type, in_regs, fndecl,
5104 initial_offset_ptr, offset_ptr, arg_size_ptr,
5106 enum machine_mode passed_mode;
5108 int in_regs ATTRIBUTE_UNUSED;
5109 tree fndecl ATTRIBUTE_UNUSED;
5110 struct args_size *initial_offset_ptr;
5111 struct args_size *offset_ptr;
5112 struct args_size *arg_size_ptr;
5113 struct args_size *alignment_pad;
5117 = type ? size_in_bytes (type) : size_int (GET_MODE_SIZE (passed_mode));
5118 enum direction where_pad = FUNCTION_ARG_PADDING (passed_mode, type);
5119 int boundary = FUNCTION_ARG_BOUNDARY (passed_mode, type);
5121 #ifdef REG_PARM_STACK_SPACE
5122 /* If we have found a stack parm before we reach the end of the
5123 area reserved for registers, skip that area. */
5126 int reg_parm_stack_space = 0;
5128 #ifdef MAYBE_REG_PARM_STACK_SPACE
5129 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
5131 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
5133 if (reg_parm_stack_space > 0)
5135 if (initial_offset_ptr->var)
5137 initial_offset_ptr->var
5138 = size_binop (MAX_EXPR, ARGS_SIZE_TREE (*initial_offset_ptr),
5139 ssize_int (reg_parm_stack_space));
5140 initial_offset_ptr->constant = 0;
5142 else if (initial_offset_ptr->constant < reg_parm_stack_space)
5143 initial_offset_ptr->constant = reg_parm_stack_space;
5146 #endif /* REG_PARM_STACK_SPACE */
5148 arg_size_ptr->var = 0;
5149 arg_size_ptr->constant = 0;
5151 #ifdef ARGS_GROW_DOWNWARD
5152 if (initial_offset_ptr->var)
5154 offset_ptr->constant = 0;
5155 offset_ptr->var = size_binop (MINUS_EXPR, ssize_int (0),
5156 initial_offset_ptr->var);
5160 offset_ptr->constant = -initial_offset_ptr->constant;
5161 offset_ptr->var = 0;
5163 if (where_pad != none
5164 && (TREE_CODE (sizetree) != INTEGER_CST
5165 || ((TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)))
5166 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
5167 SUB_PARM_SIZE (*offset_ptr, sizetree);
5168 if (where_pad != downward)
5169 pad_to_arg_alignment (offset_ptr, boundary, alignment_pad);
5170 if (initial_offset_ptr->var)
5171 arg_size_ptr->var = size_binop (MINUS_EXPR,
5172 size_binop (MINUS_EXPR,
5174 initial_offset_ptr->var),
5178 arg_size_ptr->constant = (-initial_offset_ptr->constant
5179 - offset_ptr->constant);
5181 #else /* !ARGS_GROW_DOWNWARD */
5182 pad_to_arg_alignment (initial_offset_ptr, boundary, alignment_pad);
5183 *offset_ptr = *initial_offset_ptr;
5185 #ifdef PUSH_ROUNDING
5186 if (passed_mode != BLKmode)
5187 sizetree = size_int (PUSH_ROUNDING (TREE_INT_CST_LOW (sizetree)));
5190 /* Pad_below needs the pre-rounded size to know how much to pad below
5191 so this must be done before rounding up. */
5192 if (where_pad == downward
5193 /* However, BLKmode args passed in regs have their padding done elsewhere.
5194 The stack slot must be able to hold the entire register. */
5195 && !(in_regs && passed_mode == BLKmode))
5196 pad_below (offset_ptr, passed_mode, sizetree);
5198 if (where_pad != none
5199 && (TREE_CODE (sizetree) != INTEGER_CST
5200 || ((TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)))
5201 sizetree = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
5203 ADD_PARM_SIZE (*arg_size_ptr, sizetree);
5204 #endif /* ARGS_GROW_DOWNWARD */
5207 /* Round the stack offset in *OFFSET_PTR up to a multiple of BOUNDARY.
5208 BOUNDARY is measured in bits, but must be a multiple of a storage unit. */
5211 pad_to_arg_alignment (offset_ptr, boundary, alignment_pad)
5212 struct args_size *offset_ptr;
5214 struct args_size *alignment_pad;
5216 tree save_var = NULL_TREE;
5217 HOST_WIDE_INT save_constant = 0;
5219 int boundary_in_bytes = boundary / BITS_PER_UNIT;
5221 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
5223 save_var = offset_ptr->var;
5224 save_constant = offset_ptr->constant;
5227 alignment_pad->var = NULL_TREE;
5228 alignment_pad->constant = 0;
5230 if (boundary > BITS_PER_UNIT)
5232 if (offset_ptr->var)
5235 #ifdef ARGS_GROW_DOWNWARD
5240 (ARGS_SIZE_TREE (*offset_ptr),
5241 boundary / BITS_PER_UNIT);
5242 offset_ptr->constant = 0; /*?*/
5243 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
5244 alignment_pad->var = size_binop (MINUS_EXPR, offset_ptr->var,
5249 offset_ptr->constant =
5250 #ifdef ARGS_GROW_DOWNWARD
5251 FLOOR_ROUND (offset_ptr->constant, boundary_in_bytes);
5253 CEIL_ROUND (offset_ptr->constant, boundary_in_bytes);
5255 if (boundary > PARM_BOUNDARY && boundary > STACK_BOUNDARY)
5256 alignment_pad->constant = offset_ptr->constant - save_constant;
5261 #ifndef ARGS_GROW_DOWNWARD
5263 pad_below (offset_ptr, passed_mode, sizetree)
5264 struct args_size *offset_ptr;
5265 enum machine_mode passed_mode;
5268 if (passed_mode != BLKmode)
5270 if (GET_MODE_BITSIZE (passed_mode) % PARM_BOUNDARY)
5271 offset_ptr->constant
5272 += (((GET_MODE_BITSIZE (passed_mode) + PARM_BOUNDARY - 1)
5273 / PARM_BOUNDARY * PARM_BOUNDARY / BITS_PER_UNIT)
5274 - GET_MODE_SIZE (passed_mode));
5278 if (TREE_CODE (sizetree) != INTEGER_CST
5279 || (TREE_INT_CST_LOW (sizetree) * BITS_PER_UNIT) % PARM_BOUNDARY)
5281 /* Round the size up to multiple of PARM_BOUNDARY bits. */
5282 tree s2 = round_up (sizetree, PARM_BOUNDARY / BITS_PER_UNIT);
5284 ADD_PARM_SIZE (*offset_ptr, s2);
5285 SUB_PARM_SIZE (*offset_ptr, sizetree);
5291 /* Walk the tree of blocks describing the binding levels within a function
5292 and warn about uninitialized variables.
5293 This is done after calling flow_analysis and before global_alloc
5294 clobbers the pseudo-regs to hard regs. */
5297 uninitialized_vars_warning (block)
5300 register tree decl, sub;
5301 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
5303 if (warn_uninitialized
5304 && TREE_CODE (decl) == VAR_DECL
5305 /* These warnings are unreliable for and aggregates
5306 because assigning the fields one by one can fail to convince
5307 flow.c that the entire aggregate was initialized.
5308 Unions are troublesome because members may be shorter. */
5309 && ! AGGREGATE_TYPE_P (TREE_TYPE (decl))
5310 && DECL_RTL (decl) != 0
5311 && GET_CODE (DECL_RTL (decl)) == REG
5312 /* Global optimizations can make it difficult to determine if a
5313 particular variable has been initialized. However, a VAR_DECL
5314 with a nonzero DECL_INITIAL had an initializer, so do not
5315 claim it is potentially uninitialized.
5317 We do not care about the actual value in DECL_INITIAL, so we do
5318 not worry that it may be a dangling pointer. */
5319 && DECL_INITIAL (decl) == NULL_TREE
5320 && regno_uninitialized (REGNO (DECL_RTL (decl))))
5321 warning_with_decl (decl,
5322 "`%s' might be used uninitialized in this function");
5324 && TREE_CODE (decl) == VAR_DECL
5325 && DECL_RTL (decl) != 0
5326 && GET_CODE (DECL_RTL (decl)) == REG
5327 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
5328 warning_with_decl (decl,
5329 "variable `%s' might be clobbered by `longjmp' or `vfork'");
5331 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
5332 uninitialized_vars_warning (sub);
5335 /* Do the appropriate part of uninitialized_vars_warning
5336 but for arguments instead of local variables. */
5339 setjmp_args_warning ()
5342 for (decl = DECL_ARGUMENTS (current_function_decl);
5343 decl; decl = TREE_CHAIN (decl))
5344 if (DECL_RTL (decl) != 0
5345 && GET_CODE (DECL_RTL (decl)) == REG
5346 && regno_clobbered_at_setjmp (REGNO (DECL_RTL (decl))))
5347 warning_with_decl (decl,
5348 "argument `%s' might be clobbered by `longjmp' or `vfork'");
5351 /* If this function call setjmp, put all vars into the stack
5352 unless they were declared `register'. */
5355 setjmp_protect (block)
5358 register tree decl, sub;
5359 for (decl = BLOCK_VARS (block); decl; decl = TREE_CHAIN (decl))
5360 if ((TREE_CODE (decl) == VAR_DECL
5361 || TREE_CODE (decl) == PARM_DECL)
5362 && DECL_RTL (decl) != 0
5363 && (GET_CODE (DECL_RTL (decl)) == REG
5364 || (GET_CODE (DECL_RTL (decl)) == MEM
5365 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == ADDRESSOF))
5366 /* If this variable came from an inline function, it must be
5367 that its life doesn't overlap the setjmp. If there was a
5368 setjmp in the function, it would already be in memory. We
5369 must exclude such variable because their DECL_RTL might be
5370 set to strange things such as virtual_stack_vars_rtx. */
5371 && ! DECL_FROM_INLINE (decl)
5373 #ifdef NON_SAVING_SETJMP
5374 /* If longjmp doesn't restore the registers,
5375 don't put anything in them. */
5379 ! DECL_REGISTER (decl)))
5380 put_var_into_stack (decl);
5381 for (sub = BLOCK_SUBBLOCKS (block); sub; sub = TREE_CHAIN (sub))
5382 setjmp_protect (sub);
5385 /* Like the previous function, but for args instead of local variables. */
5388 setjmp_protect_args ()
5391 for (decl = DECL_ARGUMENTS (current_function_decl);
5392 decl; decl = TREE_CHAIN (decl))
5393 if ((TREE_CODE (decl) == VAR_DECL
5394 || TREE_CODE (decl) == PARM_DECL)
5395 && DECL_RTL (decl) != 0
5396 && (GET_CODE (DECL_RTL (decl)) == REG
5397 || (GET_CODE (DECL_RTL (decl)) == MEM
5398 && GET_CODE (XEXP (DECL_RTL (decl), 0)) == ADDRESSOF))
5400 /* If longjmp doesn't restore the registers,
5401 don't put anything in them. */
5402 #ifdef NON_SAVING_SETJMP
5406 ! DECL_REGISTER (decl)))
5407 put_var_into_stack (decl);
5410 /* Return the context-pointer register corresponding to DECL,
5411 or 0 if it does not need one. */
5414 lookup_static_chain (decl)
5417 tree context = decl_function_context (decl);
5421 || (TREE_CODE (decl) == FUNCTION_DECL && DECL_NO_STATIC_CHAIN (decl)))
5424 /* We treat inline_function_decl as an alias for the current function
5425 because that is the inline function whose vars, types, etc.
5426 are being merged into the current function.
5427 See expand_inline_function. */
5428 if (context == current_function_decl || context == inline_function_decl)
5429 return virtual_stack_vars_rtx;
5431 for (link = context_display; link; link = TREE_CHAIN (link))
5432 if (TREE_PURPOSE (link) == context)
5433 return RTL_EXPR_RTL (TREE_VALUE (link));
5438 /* Convert a stack slot address ADDR for variable VAR
5439 (from a containing function)
5440 into an address valid in this function (using a static chain). */
5443 fix_lexical_addr (addr, var)
5448 HOST_WIDE_INT displacement;
5449 tree context = decl_function_context (var);
5450 struct function *fp;
5453 /* If this is the present function, we need not do anything. */
5454 if (context == current_function_decl || context == inline_function_decl)
5457 for (fp = outer_function_chain; fp; fp = fp->next)
5458 if (fp->decl == context)
5464 if (GET_CODE (addr) == ADDRESSOF && GET_CODE (XEXP (addr, 0)) == MEM)
5465 addr = XEXP (XEXP (addr, 0), 0);
5467 /* Decode given address as base reg plus displacement. */
5468 if (GET_CODE (addr) == REG)
5469 basereg = addr, displacement = 0;
5470 else if (GET_CODE (addr) == PLUS && GET_CODE (XEXP (addr, 1)) == CONST_INT)
5471 basereg = XEXP (addr, 0), displacement = INTVAL (XEXP (addr, 1));
5475 /* We accept vars reached via the containing function's
5476 incoming arg pointer and via its stack variables pointer. */
5477 if (basereg == fp->internal_arg_pointer)
5479 /* If reached via arg pointer, get the arg pointer value
5480 out of that function's stack frame.
5482 There are two cases: If a separate ap is needed, allocate a
5483 slot in the outer function for it and dereference it that way.
5484 This is correct even if the real ap is actually a pseudo.
5485 Otherwise, just adjust the offset from the frame pointer to
5488 #ifdef NEED_SEPARATE_AP
5491 if (fp->x_arg_pointer_save_area == 0)
5492 fp->x_arg_pointer_save_area
5493 = assign_stack_local_1 (Pmode, GET_MODE_SIZE (Pmode), 0, fp);
5495 addr = fix_lexical_addr (XEXP (fp->x_arg_pointer_save_area, 0), var);
5496 addr = memory_address (Pmode, addr);
5498 base = gen_rtx_MEM (Pmode, addr);
5499 MEM_ALIAS_SET (base) = get_frame_alias_set ();
5500 base = copy_to_reg (base);
5502 displacement += (FIRST_PARM_OFFSET (context) - STARTING_FRAME_OFFSET);
5503 base = lookup_static_chain (var);
5507 else if (basereg == virtual_stack_vars_rtx)
5509 /* This is the same code as lookup_static_chain, duplicated here to
5510 avoid an extra call to decl_function_context. */
5513 for (link = context_display; link; link = TREE_CHAIN (link))
5514 if (TREE_PURPOSE (link) == context)
5516 base = RTL_EXPR_RTL (TREE_VALUE (link));
5524 /* Use same offset, relative to appropriate static chain or argument
5526 return plus_constant (base, displacement);
5529 /* Return the address of the trampoline for entering nested fn FUNCTION.
5530 If necessary, allocate a trampoline (in the stack frame)
5531 and emit rtl to initialize its contents (at entry to this function). */
5534 trampoline_address (function)
5540 struct function *fp;
5543 /* Find an existing trampoline and return it. */
5544 for (link = trampoline_list; link; link = TREE_CHAIN (link))
5545 if (TREE_PURPOSE (link) == function)
5547 round_trampoline_addr (XEXP (RTL_EXPR_RTL (TREE_VALUE (link)), 0));
5549 for (fp = outer_function_chain; fp; fp = fp->next)
5550 for (link = fp->x_trampoline_list; link; link = TREE_CHAIN (link))
5551 if (TREE_PURPOSE (link) == function)
5553 tramp = fix_lexical_addr (XEXP (RTL_EXPR_RTL (TREE_VALUE (link)), 0),
5555 return round_trampoline_addr (tramp);
5558 /* None exists; we must make one. */
5560 /* Find the `struct function' for the function containing FUNCTION. */
5562 fn_context = decl_function_context (function);
5563 if (fn_context != current_function_decl
5564 && fn_context != inline_function_decl)
5565 for (fp = outer_function_chain; fp; fp = fp->next)
5566 if (fp->decl == fn_context)
5569 /* Allocate run-time space for this trampoline
5570 (usually in the defining function's stack frame). */
5571 #ifdef ALLOCATE_TRAMPOLINE
5572 tramp = ALLOCATE_TRAMPOLINE (fp);
5574 /* If rounding needed, allocate extra space
5575 to ensure we have TRAMPOLINE_SIZE bytes left after rounding up. */
5576 #ifdef TRAMPOLINE_ALIGNMENT
5577 #define TRAMPOLINE_REAL_SIZE \
5578 (TRAMPOLINE_SIZE + (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT) - 1)
5580 #define TRAMPOLINE_REAL_SIZE (TRAMPOLINE_SIZE)
5582 tramp = assign_stack_local_1 (BLKmode, TRAMPOLINE_REAL_SIZE, 0,
5586 /* Record the trampoline for reuse and note it for later initialization
5587 by expand_function_end. */
5590 push_obstacks (fp->function_maybepermanent_obstack,
5591 fp->function_maybepermanent_obstack);
5592 rtlexp = make_node (RTL_EXPR);
5593 RTL_EXPR_RTL (rtlexp) = tramp;
5594 fp->x_trampoline_list = tree_cons (function, rtlexp,
5595 fp->x_trampoline_list);
5600 /* Make the RTL_EXPR node temporary, not momentary, so that the
5601 trampoline_list doesn't become garbage. */
5602 int momentary = suspend_momentary ();
5603 rtlexp = make_node (RTL_EXPR);
5604 resume_momentary (momentary);
5606 RTL_EXPR_RTL (rtlexp) = tramp;
5607 trampoline_list = tree_cons (function, rtlexp, trampoline_list);
5610 tramp = fix_lexical_addr (XEXP (tramp, 0), function);
5611 return round_trampoline_addr (tramp);
5614 /* Given a trampoline address,
5615 round it to multiple of TRAMPOLINE_ALIGNMENT. */
5618 round_trampoline_addr (tramp)
5621 #ifdef TRAMPOLINE_ALIGNMENT
5622 /* Round address up to desired boundary. */
5623 rtx temp = gen_reg_rtx (Pmode);
5624 temp = expand_binop (Pmode, add_optab, tramp,
5625 GEN_INT (TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT - 1),
5626 temp, 0, OPTAB_LIB_WIDEN);
5627 tramp = expand_binop (Pmode, and_optab, temp,
5628 GEN_INT (-TRAMPOLINE_ALIGNMENT / BITS_PER_UNIT),
5629 temp, 0, OPTAB_LIB_WIDEN);
5634 /* Put all this function's BLOCK nodes including those that are chained
5635 onto the first block into a vector, and return it.
5636 Also store in each NOTE for the beginning or end of a block
5637 the index of that block in the vector.
5638 The arguments are BLOCK, the chain of top-level blocks of the function,
5639 and INSNS, the insn chain of the function. */
5645 tree *block_vector, *last_block_vector;
5647 tree block = DECL_INITIAL (current_function_decl);
5652 /* Fill the BLOCK_VECTOR with all of the BLOCKs in this function, in
5653 depth-first order. */
5654 block_vector = get_block_vector (block, &n_blocks);
5655 block_stack = (tree *) xmalloc (n_blocks * sizeof (tree));
5657 last_block_vector = identify_blocks_1 (get_insns (),
5659 block_vector + n_blocks,
5662 /* If we didn't use all of the subblocks, we've misplaced block notes. */
5663 /* ??? This appears to happen all the time. Latent bugs elsewhere? */
5664 if (0 && last_block_vector != block_vector + n_blocks)
5667 free (block_vector);
5671 /* Subroutine of identify_blocks. Do the block substitution on the
5672 insn chain beginning with INSNS. Recurse for CALL_PLACEHOLDER chains.
5674 BLOCK_STACK is pushed and popped for each BLOCK_BEGIN/BLOCK_END pair.
5675 BLOCK_VECTOR is incremented for each block seen. */
5678 identify_blocks_1 (insns, block_vector, end_block_vector, orig_block_stack)
5681 tree *end_block_vector;
5682 tree *orig_block_stack;
5685 tree *block_stack = orig_block_stack;
5687 for (insn = insns; insn; insn = NEXT_INSN (insn))
5689 if (GET_CODE (insn) == NOTE)
5691 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
5695 /* If there are more block notes than BLOCKs, something
5697 if (block_vector == end_block_vector)
5700 b = *block_vector++;
5701 NOTE_BLOCK (insn) = b;
5704 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
5706 /* If there are more NOTE_INSN_BLOCK_ENDs than
5707 NOTE_INSN_BLOCK_BEGs, something is badly wrong. */
5708 if (block_stack == orig_block_stack)
5711 NOTE_BLOCK (insn) = *--block_stack;
5714 else if (GET_CODE (insn) == CALL_INSN
5715 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
5717 rtx cp = PATTERN (insn);
5719 block_vector = identify_blocks_1 (XEXP (cp, 0), block_vector,
5720 end_block_vector, block_stack);
5722 block_vector = identify_blocks_1 (XEXP (cp, 1), block_vector,
5723 end_block_vector, block_stack);
5725 block_vector = identify_blocks_1 (XEXP (cp, 2), block_vector,
5726 end_block_vector, block_stack);
5730 /* If there are more NOTE_INSN_BLOCK_BEGINs than NOTE_INSN_BLOCK_ENDs,
5731 something is badly wrong. */
5732 if (block_stack != orig_block_stack)
5735 return block_vector;
5738 /* Identify BLOCKs referenced by more than one
5739 NOTE_INSN_BLOCK_{BEG,END}, and create duplicate blocks. */
5744 tree block = DECL_INITIAL (current_function_decl);
5745 varray_type block_stack;
5747 if (block == NULL_TREE)
5750 VARRAY_TREE_INIT (block_stack, 10, "block_stack");
5752 /* Prune the old trees away, so that they don't get in the way. */
5753 BLOCK_SUBBLOCKS (block) = NULL_TREE;
5754 BLOCK_CHAIN (block) = NULL_TREE;
5756 reorder_blocks_1 (get_insns (), block, &block_stack);
5758 BLOCK_SUBBLOCKS (block) = blocks_nreverse (BLOCK_SUBBLOCKS (block));
5760 VARRAY_FREE (block_stack);
5763 /* Helper function for reorder_blocks. Process the insn chain beginning
5764 at INSNS. Recurse for CALL_PLACEHOLDER insns. */
5767 reorder_blocks_1 (insns, current_block, p_block_stack)
5770 varray_type *p_block_stack;
5774 for (insn = insns; insn; insn = NEXT_INSN (insn))
5776 if (GET_CODE (insn) == NOTE)
5778 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG)
5780 tree block = NOTE_BLOCK (insn);
5781 /* If we have seen this block before, copy it. */
5782 if (TREE_ASM_WRITTEN (block))
5784 block = copy_node (block);
5785 NOTE_BLOCK (insn) = block;
5787 BLOCK_SUBBLOCKS (block) = 0;
5788 TREE_ASM_WRITTEN (block) = 1;
5789 BLOCK_SUPERCONTEXT (block) = current_block;
5790 BLOCK_CHAIN (block) = BLOCK_SUBBLOCKS (current_block);
5791 BLOCK_SUBBLOCKS (current_block) = block;
5792 current_block = block;
5793 VARRAY_PUSH_TREE (*p_block_stack, block);
5795 else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)
5797 NOTE_BLOCK (insn) = VARRAY_TOP_TREE (*p_block_stack);
5798 VARRAY_POP (*p_block_stack);
5799 BLOCK_SUBBLOCKS (current_block)
5800 = blocks_nreverse (BLOCK_SUBBLOCKS (current_block));
5801 current_block = BLOCK_SUPERCONTEXT (current_block);
5804 else if (GET_CODE (insn) == CALL_INSN
5805 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
5807 rtx cp = PATTERN (insn);
5808 reorder_blocks_1 (XEXP (cp, 0), current_block, p_block_stack);
5810 reorder_blocks_1 (XEXP (cp, 1), current_block, p_block_stack);
5812 reorder_blocks_1 (XEXP (cp, 2), current_block, p_block_stack);
5817 /* Reverse the order of elements in the chain T of blocks,
5818 and return the new head of the chain (old last element). */
5824 register tree prev = 0, decl, next;
5825 for (decl = t; decl; decl = next)
5827 next = BLOCK_CHAIN (decl);
5828 BLOCK_CHAIN (decl) = prev;
5834 /* Count the subblocks of the list starting with BLOCK. If VECTOR is
5835 non-NULL, list them all into VECTOR, in a depth-first preorder
5836 traversal of the block tree. Also clear TREE_ASM_WRITTEN in all
5840 all_blocks (block, vector)
5848 TREE_ASM_WRITTEN (block) = 0;
5850 /* Record this block. */
5852 vector[n_blocks] = block;
5856 /* Record the subblocks, and their subblocks... */
5857 n_blocks += all_blocks (BLOCK_SUBBLOCKS (block),
5858 vector ? vector + n_blocks : 0);
5859 block = BLOCK_CHAIN (block);
5865 /* Return a vector containing all the blocks rooted at BLOCK. The
5866 number of elements in the vector is stored in N_BLOCKS_P. The
5867 vector is dynamically allocated; it is the caller's responsibility
5868 to call `free' on the pointer returned. */
5871 get_block_vector (block, n_blocks_p)
5877 *n_blocks_p = all_blocks (block, NULL);
5878 block_vector = (tree *) xmalloc (*n_blocks_p * sizeof (tree));
5879 all_blocks (block, block_vector);
5881 return block_vector;
5884 static int next_block_index = 2;
5886 /* Set BLOCK_NUMBER for all the blocks in FN. */
5896 /* For SDB and XCOFF debugging output, we start numbering the blocks
5897 from 1 within each function, rather than keeping a running
5899 #if defined (SDB_DEBUGGING_INFO) || defined (XCOFF_DEBUGGING_INFO)
5900 if (write_symbols == SDB_DEBUG || write_symbols == XCOFF_DEBUG)
5901 next_block_index = 1;
5904 block_vector = get_block_vector (DECL_INITIAL (fn), &n_blocks);
5906 /* The top-level BLOCK isn't numbered at all. */
5907 for (i = 1; i < n_blocks; ++i)
5908 /* We number the blocks from two. */
5909 BLOCK_NUMBER (block_vector[i]) = next_block_index++;
5911 free (block_vector);
5916 /* Allocate a function structure and reset its contents to the defaults. */
5918 prepare_function_start ()
5920 cfun = (struct function *) xcalloc (1, sizeof (struct function));
5922 init_stmt_for_function ();
5923 init_eh_for_function ();
5925 cse_not_expected = ! optimize;
5927 /* Caller save not needed yet. */
5928 caller_save_needed = 0;
5930 /* No stack slots have been made yet. */
5931 stack_slot_list = 0;
5933 current_function_has_nonlocal_label = 0;
5934 current_function_has_nonlocal_goto = 0;
5936 /* There is no stack slot for handling nonlocal gotos. */
5937 nonlocal_goto_handler_slots = 0;
5938 nonlocal_goto_stack_level = 0;
5940 /* No labels have been declared for nonlocal use. */
5941 nonlocal_labels = 0;
5942 nonlocal_goto_handler_labels = 0;
5944 /* No function calls so far in this function. */
5945 function_call_count = 0;
5947 /* No parm regs have been allocated.
5948 (This is important for output_inline_function.) */
5949 max_parm_reg = LAST_VIRTUAL_REGISTER + 1;
5951 /* Initialize the RTL mechanism. */
5954 /* Initialize the queue of pending postincrement and postdecrements,
5955 and some other info in expr.c. */
5958 /* We haven't done register allocation yet. */
5961 init_varasm_status (cfun);
5963 /* Clear out data used for inlining. */
5964 cfun->inlinable = 0;
5965 cfun->original_decl_initial = 0;
5966 cfun->original_arg_vector = 0;
5968 #ifdef STACK_BOUNDARY
5969 cfun->stack_alignment_needed = STACK_BOUNDARY;
5970 cfun->preferred_stack_boundary = STACK_BOUNDARY;
5972 cfun->stack_alignment_needed = 0;
5973 cfun->preferred_stack_boundary = 0;
5976 /* Set if a call to setjmp is seen. */
5977 current_function_calls_setjmp = 0;
5979 /* Set if a call to longjmp is seen. */
5980 current_function_calls_longjmp = 0;
5982 current_function_calls_alloca = 0;
5983 current_function_contains_functions = 0;
5984 current_function_is_leaf = 0;
5985 current_function_nothrow = 0;
5986 current_function_sp_is_unchanging = 0;
5987 current_function_uses_only_leaf_regs = 0;
5988 current_function_has_computed_jump = 0;
5989 current_function_is_thunk = 0;
5991 current_function_returns_pcc_struct = 0;
5992 current_function_returns_struct = 0;
5993 current_function_epilogue_delay_list = 0;
5994 current_function_uses_const_pool = 0;
5995 current_function_uses_pic_offset_table = 0;
5996 current_function_cannot_inline = 0;
5998 /* We have not yet needed to make a label to jump to for tail-recursion. */
5999 tail_recursion_label = 0;
6001 /* We haven't had a need to make a save area for ap yet. */
6002 arg_pointer_save_area = 0;
6004 /* No stack slots allocated yet. */
6007 /* No SAVE_EXPRs in this function yet. */
6010 /* No RTL_EXPRs in this function yet. */
6013 /* Set up to allocate temporaries. */
6016 /* Indicate that we need to distinguish between the return value of the
6017 present function and the return value of a function being called. */
6018 rtx_equal_function_value_matters = 1;
6020 /* Indicate that we have not instantiated virtual registers yet. */
6021 virtuals_instantiated = 0;
6023 /* Indicate that we want CONCATs now. */
6024 generating_concat_p = 1;
6026 /* Indicate we have no need of a frame pointer yet. */
6027 frame_pointer_needed = 0;
6029 /* By default assume not varargs or stdarg. */
6030 current_function_varargs = 0;
6031 current_function_stdarg = 0;
6033 /* We haven't made any trampolines for this function yet. */
6034 trampoline_list = 0;
6036 init_pending_stack_adjust ();
6037 inhibit_defer_pop = 0;
6039 current_function_outgoing_args_size = 0;
6041 if (init_lang_status)
6042 (*init_lang_status) (cfun);
6043 if (init_machine_status)
6044 (*init_machine_status) (cfun);
6047 /* Initialize the rtl expansion mechanism so that we can do simple things
6048 like generate sequences. This is used to provide a context during global
6049 initialization of some passes. */
6051 init_dummy_function_start ()
6053 prepare_function_start ();
6056 /* Generate RTL for the start of the function SUBR (a FUNCTION_DECL tree node)
6057 and initialize static variables for generating RTL for the statements
6061 init_function_start (subr, filename, line)
6063 const char *filename;
6066 prepare_function_start ();
6068 /* Remember this function for later. */
6069 cfun->next_global = all_functions;
6070 all_functions = cfun;
6072 current_function_name = (*decl_printable_name) (subr, 2);
6075 /* Nonzero if this is a nested function that uses a static chain. */
6077 current_function_needs_context
6078 = (decl_function_context (current_function_decl) != 0
6079 && ! DECL_NO_STATIC_CHAIN (current_function_decl));
6081 /* Within function body, compute a type's size as soon it is laid out. */
6082 immediate_size_expand++;
6084 /* Prevent ever trying to delete the first instruction of a function.
6085 Also tell final how to output a linenum before the function prologue.
6086 Note linenums could be missing, e.g. when compiling a Java .class file. */
6088 emit_line_note (filename, line);
6090 /* Make sure first insn is a note even if we don't want linenums.
6091 This makes sure the first insn will never be deleted.
6092 Also, final expects a note to appear there. */
6093 emit_note (NULL_PTR, NOTE_INSN_DELETED);
6095 /* Set flags used by final.c. */
6096 if (aggregate_value_p (DECL_RESULT (subr)))
6098 #ifdef PCC_STATIC_STRUCT_RETURN
6099 current_function_returns_pcc_struct = 1;
6101 current_function_returns_struct = 1;
6104 /* Warn if this value is an aggregate type,
6105 regardless of which calling convention we are using for it. */
6106 if (warn_aggregate_return
6107 && AGGREGATE_TYPE_P (TREE_TYPE (DECL_RESULT (subr))))
6108 warning ("function returns an aggregate");
6110 current_function_returns_pointer
6111 = POINTER_TYPE_P (TREE_TYPE (DECL_RESULT (subr)));
6114 /* Make sure all values used by the optimization passes have sane
6117 init_function_for_compilation ()
6121 /* No prologue/epilogue insns yet. */
6122 VARRAY_GROW (prologue, 0);
6123 VARRAY_GROW (epilogue, 0);
6124 VARRAY_GROW (sibcall_epilogue, 0);
6127 /* Indicate that the current function uses extra args
6128 not explicitly mentioned in the argument list in any fashion. */
6133 current_function_varargs = 1;
6136 /* Expand a call to __main at the beginning of a possible main function. */
6138 #if defined(INIT_SECTION_ASM_OP) && !defined(INVOKE__main)
6139 #undef HAS_INIT_SECTION
6140 #define HAS_INIT_SECTION
6144 expand_main_function ()
6146 #if !defined (HAS_INIT_SECTION)
6147 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, NAME__MAIN), 0,
6149 #endif /* not HAS_INIT_SECTION */
6152 extern struct obstack permanent_obstack;
6154 /* Start the RTL for a new function, and set variables used for
6156 SUBR is the FUNCTION_DECL node.
6157 PARMS_HAVE_CLEANUPS is nonzero if there are cleanups associated with
6158 the function's parameters, which must be run at any return statement. */
6161 expand_function_start (subr, parms_have_cleanups)
6163 int parms_have_cleanups;
6166 rtx last_ptr = NULL_RTX;
6168 /* Make sure volatile mem refs aren't considered
6169 valid operands of arithmetic insns. */
6170 init_recog_no_volatile ();
6172 /* Set this before generating any memory accesses. */
6173 current_function_check_memory_usage
6174 = (flag_check_memory_usage
6175 && ! DECL_NO_CHECK_MEMORY_USAGE (current_function_decl));
6177 current_function_instrument_entry_exit
6178 = (flag_instrument_function_entry_exit
6179 && ! DECL_NO_INSTRUMENT_FUNCTION_ENTRY_EXIT (subr));
6181 current_function_limit_stack
6182 = (stack_limit_rtx != NULL_RTX && ! DECL_NO_LIMIT_STACK (subr));
6184 /* If function gets a static chain arg, store it in the stack frame.
6185 Do this first, so it gets the first stack slot offset. */
6186 if (current_function_needs_context)
6188 last_ptr = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0);
6190 /* Delay copying static chain if it is not a register to avoid
6191 conflicts with regs used for parameters. */
6192 if (! SMALL_REGISTER_CLASSES
6193 || GET_CODE (static_chain_incoming_rtx) == REG)
6194 emit_move_insn (last_ptr, static_chain_incoming_rtx);
6197 /* If the parameters of this function need cleaning up, get a label
6198 for the beginning of the code which executes those cleanups. This must
6199 be done before doing anything with return_label. */
6200 if (parms_have_cleanups)
6201 cleanup_label = gen_label_rtx ();
6205 /* Make the label for return statements to jump to, if this machine
6206 does not have a one-instruction return and uses an epilogue,
6207 or if it returns a structure, or if it has parm cleanups. */
6209 if (cleanup_label == 0 && HAVE_return
6210 && ! current_function_instrument_entry_exit
6211 && ! current_function_returns_pcc_struct
6212 && ! (current_function_returns_struct && ! optimize))
6215 return_label = gen_label_rtx ();
6217 return_label = gen_label_rtx ();
6220 /* Initialize rtx used to return the value. */
6221 /* Do this before assign_parms so that we copy the struct value address
6222 before any library calls that assign parms might generate. */
6224 /* Decide whether to return the value in memory or in a register. */
6225 if (aggregate_value_p (DECL_RESULT (subr)))
6227 /* Returning something that won't go in a register. */
6228 register rtx value_address = 0;
6230 #ifdef PCC_STATIC_STRUCT_RETURN
6231 if (current_function_returns_pcc_struct)
6233 int size = int_size_in_bytes (TREE_TYPE (DECL_RESULT (subr)));
6234 value_address = assemble_static_space (size);
6239 /* Expect to be passed the address of a place to store the value.
6240 If it is passed as an argument, assign_parms will take care of
6242 if (struct_value_incoming_rtx)
6244 value_address = gen_reg_rtx (Pmode);
6245 emit_move_insn (value_address, struct_value_incoming_rtx);
6250 DECL_RTL (DECL_RESULT (subr))
6251 = gen_rtx_MEM (DECL_MODE (DECL_RESULT (subr)), value_address);
6252 set_mem_attributes (DECL_RTL (DECL_RESULT (subr)),
6253 DECL_RESULT (subr), 1);
6256 else if (DECL_MODE (DECL_RESULT (subr)) == VOIDmode)
6257 /* If return mode is void, this decl rtl should not be used. */
6258 DECL_RTL (DECL_RESULT (subr)) = 0;
6259 else if (parms_have_cleanups || current_function_instrument_entry_exit)
6261 /* If function will end with cleanup code for parms,
6262 compute the return values into a pseudo reg,
6263 which we will copy into the true return register
6264 after the cleanups are done. */
6266 enum machine_mode mode = DECL_MODE (DECL_RESULT (subr));
6268 #ifdef PROMOTE_FUNCTION_RETURN
6269 tree type = TREE_TYPE (DECL_RESULT (subr));
6270 int unsignedp = TREE_UNSIGNED (type);
6272 mode = promote_mode (type, mode, &unsignedp, 1);
6275 DECL_RTL (DECL_RESULT (subr)) = gen_reg_rtx (mode);
6278 /* Scalar, returned in a register. */
6280 DECL_RTL (DECL_RESULT (subr))
6281 = hard_function_value (TREE_TYPE (DECL_RESULT (subr)), subr, 1);
6283 /* Mark this reg as the function's return value. */
6284 if (GET_CODE (DECL_RTL (DECL_RESULT (subr))) == REG)
6286 REG_FUNCTION_VALUE_P (DECL_RTL (DECL_RESULT (subr))) = 1;
6287 /* Needed because we may need to move this to memory
6288 in case it's a named return value whose address is taken. */
6289 DECL_REGISTER (DECL_RESULT (subr)) = 1;
6293 /* Initialize rtx for parameters and local variables.
6294 In some cases this requires emitting insns. */
6296 assign_parms (subr);
6298 /* Copy the static chain now if it wasn't a register. The delay is to
6299 avoid conflicts with the parameter passing registers. */
6301 if (SMALL_REGISTER_CLASSES && current_function_needs_context)
6302 if (GET_CODE (static_chain_incoming_rtx) != REG)
6303 emit_move_insn (last_ptr, static_chain_incoming_rtx);
6305 /* The following was moved from init_function_start.
6306 The move is supposed to make sdb output more accurate. */
6307 /* Indicate the beginning of the function body,
6308 as opposed to parm setup. */
6309 emit_note (NULL_PTR, NOTE_INSN_FUNCTION_BEG);
6311 if (GET_CODE (get_last_insn ()) != NOTE)
6312 emit_note (NULL_PTR, NOTE_INSN_DELETED);
6313 parm_birth_insn = get_last_insn ();
6315 context_display = 0;
6316 if (current_function_needs_context)
6318 /* Fetch static chain values for containing functions. */
6319 tem = decl_function_context (current_function_decl);
6320 /* Copy the static chain pointer into a pseudo. If we have
6321 small register classes, copy the value from memory if
6322 static_chain_incoming_rtx is a REG. */
6325 /* If the static chain originally came in a register, put it back
6326 there, then move it out in the next insn. The reason for
6327 this peculiar code is to satisfy function integration. */
6328 if (SMALL_REGISTER_CLASSES
6329 && GET_CODE (static_chain_incoming_rtx) == REG)
6330 emit_move_insn (static_chain_incoming_rtx, last_ptr);
6331 last_ptr = copy_to_reg (static_chain_incoming_rtx);
6336 tree rtlexp = make_node (RTL_EXPR);
6338 RTL_EXPR_RTL (rtlexp) = last_ptr;
6339 context_display = tree_cons (tem, rtlexp, context_display);
6340 tem = decl_function_context (tem);
6343 /* Chain thru stack frames, assuming pointer to next lexical frame
6344 is found at the place we always store it. */
6345 #ifdef FRAME_GROWS_DOWNWARD
6346 last_ptr = plus_constant (last_ptr, -GET_MODE_SIZE (Pmode));
6348 last_ptr = gen_rtx_MEM (Pmode, memory_address (Pmode, last_ptr));
6349 MEM_ALIAS_SET (last_ptr) = get_frame_alias_set ();
6350 last_ptr = copy_to_reg (last_ptr);
6352 /* If we are not optimizing, ensure that we know that this
6353 piece of context is live over the entire function. */
6355 save_expr_regs = gen_rtx_EXPR_LIST (VOIDmode, last_ptr,
6360 if (current_function_instrument_entry_exit)
6362 rtx fun = DECL_RTL (current_function_decl);
6363 if (GET_CODE (fun) == MEM)
6364 fun = XEXP (fun, 0);
6367 emit_library_call (profile_function_entry_libfunc, 0, VOIDmode, 2,
6369 expand_builtin_return_addr (BUILT_IN_RETURN_ADDRESS,
6371 hard_frame_pointer_rtx),
6375 /* After the display initializations is where the tail-recursion label
6376 should go, if we end up needing one. Ensure we have a NOTE here
6377 since some things (like trampolines) get placed before this. */
6378 tail_recursion_reentry = emit_note (NULL_PTR, NOTE_INSN_DELETED);
6380 /* Evaluate now the sizes of any types declared among the arguments. */
6381 for (tem = nreverse (get_pending_sizes ()); tem; tem = TREE_CHAIN (tem))
6383 expand_expr (TREE_VALUE (tem), const0_rtx, VOIDmode,
6384 EXPAND_MEMORY_USE_BAD);
6385 /* Flush the queue in case this parameter declaration has
6390 /* Make sure there is a line number after the function entry setup code. */
6391 force_next_line_note ();
6394 /* Undo the effects of init_dummy_function_start. */
6396 expand_dummy_function_end ()
6398 /* End any sequences that failed to be closed due to syntax errors. */
6399 while (in_sequence_p ())
6402 /* Outside function body, can't compute type's actual size
6403 until next function's body starts. */
6405 free_after_parsing (cfun);
6406 free_after_compilation (cfun);
6411 /* Call DOIT for each hard register used as a return value from
6412 the current function. */
6415 diddle_return_value (doit, arg)
6416 void (*doit) PARAMS ((rtx, void *));
6419 rtx outgoing = current_function_return_rtx;
6425 pcc = (current_function_returns_struct
6426 || current_function_returns_pcc_struct);
6428 if ((GET_CODE (outgoing) == REG
6429 && REGNO (outgoing) >= FIRST_PSEUDO_REGISTER)
6432 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
6434 /* A PCC-style return returns a pointer to the memory in which
6435 the structure is stored. */
6437 type = build_pointer_type (type);
6439 #ifdef FUNCTION_OUTGOING_VALUE
6440 outgoing = FUNCTION_OUTGOING_VALUE (type, current_function_decl);
6442 outgoing = FUNCTION_VALUE (type, current_function_decl);
6444 /* If this is a BLKmode structure being returned in registers, then use
6445 the mode computed in expand_return. */
6446 if (GET_MODE (outgoing) == BLKmode)
6447 PUT_MODE (outgoing, GET_MODE (current_function_return_rtx));
6448 REG_FUNCTION_VALUE_P (outgoing) = 1;
6451 if (GET_CODE (outgoing) == REG)
6452 (*doit) (outgoing, arg);
6453 else if (GET_CODE (outgoing) == PARALLEL)
6457 for (i = 0; i < XVECLEN (outgoing, 0); i++)
6459 rtx x = XEXP (XVECEXP (outgoing, 0, i), 0);
6461 if (GET_CODE (x) == REG && REGNO (x) < FIRST_PSEUDO_REGISTER)
6468 do_clobber_return_reg (reg, arg)
6470 void *arg ATTRIBUTE_UNUSED;
6472 emit_insn (gen_rtx_CLOBBER (VOIDmode, reg));
6476 clobber_return_register ()
6478 diddle_return_value (do_clobber_return_reg, NULL);
6482 do_use_return_reg (reg, arg)
6484 void *arg ATTRIBUTE_UNUSED;
6486 emit_insn (gen_rtx_USE (VOIDmode, reg));
6490 use_return_register ()
6492 diddle_return_value (do_use_return_reg, NULL);
6495 /* Generate RTL for the end of the current function.
6496 FILENAME and LINE are the current position in the source file.
6498 It is up to language-specific callers to do cleanups for parameters--
6499 or else, supply 1 for END_BINDINGS and we will call expand_end_bindings. */
6502 expand_function_end (filename, line, end_bindings)
6503 const char *filename;
6509 #ifdef TRAMPOLINE_TEMPLATE
6510 static rtx initial_trampoline;
6513 finish_expr_for_function ();
6515 #ifdef NON_SAVING_SETJMP
6516 /* Don't put any variables in registers if we call setjmp
6517 on a machine that fails to restore the registers. */
6518 if (NON_SAVING_SETJMP && current_function_calls_setjmp)
6520 if (DECL_INITIAL (current_function_decl) != error_mark_node)
6521 setjmp_protect (DECL_INITIAL (current_function_decl));
6523 setjmp_protect_args ();
6527 /* Save the argument pointer if a save area was made for it. */
6528 if (arg_pointer_save_area)
6530 /* arg_pointer_save_area may not be a valid memory address, so we
6531 have to check it and fix it if necessary. */
6534 emit_move_insn (validize_mem (arg_pointer_save_area),
6535 virtual_incoming_args_rtx);
6536 seq = gen_sequence ();
6538 emit_insn_before (seq, tail_recursion_reentry);
6541 /* Initialize any trampolines required by this function. */
6542 for (link = trampoline_list; link; link = TREE_CHAIN (link))
6544 tree function = TREE_PURPOSE (link);
6545 rtx context ATTRIBUTE_UNUSED = lookup_static_chain (function);
6546 rtx tramp = RTL_EXPR_RTL (TREE_VALUE (link));
6547 #ifdef TRAMPOLINE_TEMPLATE
6552 #ifdef TRAMPOLINE_TEMPLATE
6553 /* First make sure this compilation has a template for
6554 initializing trampolines. */
6555 if (initial_trampoline == 0)
6557 end_temporary_allocation ();
6559 = gen_rtx_MEM (BLKmode, assemble_trampoline_template ());
6560 resume_temporary_allocation ();
6562 ggc_add_rtx_root (&initial_trampoline, 1);
6566 /* Generate insns to initialize the trampoline. */
6568 tramp = round_trampoline_addr (XEXP (tramp, 0));
6569 #ifdef TRAMPOLINE_TEMPLATE
6570 blktramp = change_address (initial_trampoline, BLKmode, tramp);
6571 emit_block_move (blktramp, initial_trampoline,
6572 GEN_INT (TRAMPOLINE_SIZE),
6573 TRAMPOLINE_ALIGNMENT);
6575 INITIALIZE_TRAMPOLINE (tramp, XEXP (DECL_RTL (function), 0), context);
6579 /* Put those insns at entry to the containing function (this one). */
6580 emit_insns_before (seq, tail_recursion_reentry);
6583 /* If we are doing stack checking and this function makes calls,
6584 do a stack probe at the start of the function to ensure we have enough
6585 space for another stack frame. */
6586 if (flag_stack_check && ! STACK_CHECK_BUILTIN)
6590 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
6591 if (GET_CODE (insn) == CALL_INSN)
6594 probe_stack_range (STACK_CHECK_PROTECT,
6595 GEN_INT (STACK_CHECK_MAX_FRAME_SIZE));
6598 emit_insns_before (seq, tail_recursion_reentry);
6603 /* Warn about unused parms if extra warnings were specified. */
6604 /* Either ``-W -Wunused'' or ``-Wunused-parameter'' enables this
6605 warning. WARN_UNUSED_PARAMETER is negative when set by
6607 if (warn_unused_parameter > 0
6608 || (warn_unused_parameter < 0 && extra_warnings))
6612 for (decl = DECL_ARGUMENTS (current_function_decl);
6613 decl; decl = TREE_CHAIN (decl))
6614 if (! TREE_USED (decl) && TREE_CODE (decl) == PARM_DECL
6615 && DECL_NAME (decl) && ! DECL_ARTIFICIAL (decl))
6616 warning_with_decl (decl, "unused parameter `%s'");
6619 /* Delete handlers for nonlocal gotos if nothing uses them. */
6620 if (nonlocal_goto_handler_slots != 0
6621 && ! current_function_has_nonlocal_label)
6624 /* End any sequences that failed to be closed due to syntax errors. */
6625 while (in_sequence_p ())
6628 /* Outside function body, can't compute type's actual size
6629 until next function's body starts. */
6630 immediate_size_expand--;
6632 clear_pending_stack_adjust ();
6633 do_pending_stack_adjust ();
6635 /* Mark the end of the function body.
6636 If control reaches this insn, the function can drop through
6637 without returning a value. */
6638 emit_note (NULL_PTR, NOTE_INSN_FUNCTION_END);
6640 /* Must mark the last line number note in the function, so that the test
6641 coverage code can avoid counting the last line twice. This just tells
6642 the code to ignore the immediately following line note, since there
6643 already exists a copy of this note somewhere above. This line number
6644 note is still needed for debugging though, so we can't delete it. */
6645 if (flag_test_coverage)
6646 emit_note (NULL_PTR, NOTE_INSN_REPEATED_LINE_NUMBER);
6648 /* Output a linenumber for the end of the function.
6649 SDB depends on this. */
6650 emit_line_note_force (filename, line);
6652 /* Output the label for the actual return from the function,
6653 if one is expected. This happens either because a function epilogue
6654 is used instead of a return instruction, or because a return was done
6655 with a goto in order to run local cleanups, or because of pcc-style
6656 structure returning. */
6662 /* Before the return label, clobber the return registers so that
6663 they are not propogated live to the rest of the function. This
6664 can only happen with functions that drop through; if there had
6665 been a return statement, there would have either been a return
6666 rtx, or a jump to the return label. */
6668 before = get_last_insn ();
6669 clobber_return_register ();
6670 after = get_last_insn ();
6672 if (before != after)
6673 cfun->x_clobber_return_insn = after;
6675 emit_label (return_label);
6678 /* C++ uses this. */
6680 expand_end_bindings (0, 0, 0);
6682 /* Now handle any leftover exception regions that may have been
6683 created for the parameters. */
6685 rtx last = get_last_insn ();
6688 expand_leftover_cleanups ();
6690 /* If there are any catch_clauses remaining, output them now. */
6691 emit_insns (catch_clauses);
6692 catch_clauses = catch_clauses_last = NULL_RTX;
6693 /* If the above emitted any code, may sure we jump around it. */
6694 if (last != get_last_insn ())
6696 label = gen_label_rtx ();
6697 last = emit_jump_insn_after (gen_jump (label), last);
6698 last = emit_barrier_after (last);
6703 if (current_function_instrument_entry_exit)
6705 rtx fun = DECL_RTL (current_function_decl);
6706 if (GET_CODE (fun) == MEM)
6707 fun = XEXP (fun, 0);
6710 emit_library_call (profile_function_exit_libfunc, 0, VOIDmode, 2,
6712 expand_builtin_return_addr (BUILT_IN_RETURN_ADDRESS,
6714 hard_frame_pointer_rtx),
6718 /* If we had calls to alloca, and this machine needs
6719 an accurate stack pointer to exit the function,
6720 insert some code to save and restore the stack pointer. */
6721 #ifdef EXIT_IGNORE_STACK
6722 if (! EXIT_IGNORE_STACK)
6724 if (current_function_calls_alloca)
6728 emit_stack_save (SAVE_FUNCTION, &tem, parm_birth_insn);
6729 emit_stack_restore (SAVE_FUNCTION, tem, NULL_RTX);
6732 /* If scalar return value was computed in a pseudo-reg, or was a named
6733 return value that got dumped to the stack, copy that to the hard
6735 if (DECL_RTL (DECL_RESULT (current_function_decl)) != 0)
6737 tree decl_result = DECL_RESULT (current_function_decl);
6738 rtx decl_rtl = DECL_RTL (decl_result);
6740 if (REG_P (decl_rtl)
6741 ? REGNO (decl_rtl) >= FIRST_PSEUDO_REGISTER
6742 : DECL_REGISTER (decl_result))
6746 #ifdef FUNCTION_OUTGOING_VALUE
6747 real_decl_rtl = FUNCTION_OUTGOING_VALUE (TREE_TYPE (decl_result),
6748 current_function_decl);
6750 real_decl_rtl = FUNCTION_VALUE (TREE_TYPE (decl_result),
6751 current_function_decl);
6753 REG_FUNCTION_VALUE_P (real_decl_rtl) = 1;
6755 /* If this is a BLKmode structure being returned in registers,
6756 then use the mode computed in expand_return. Note that if
6757 decl_rtl is memory, then its mode may have been changed,
6758 but that current_function_return_rtx has not. */
6759 if (GET_MODE (real_decl_rtl) == BLKmode)
6760 PUT_MODE (real_decl_rtl, GET_MODE (current_function_return_rtx));
6762 /* If a named return value dumped decl_return to memory, then
6763 we may need to re-do the PROMOTE_MODE signed/unsigned
6765 if (GET_MODE (real_decl_rtl) != GET_MODE (decl_rtl))
6767 int unsignedp = TREE_UNSIGNED (TREE_TYPE (decl_result));
6769 #ifdef PROMOTE_FUNCTION_RETURN
6770 promote_mode (TREE_TYPE (decl_result), GET_MODE (decl_rtl),
6774 convert_move (real_decl_rtl, decl_rtl, unsignedp);
6777 emit_move_insn (real_decl_rtl, decl_rtl);
6779 /* The delay slot scheduler assumes that current_function_return_rtx
6780 holds the hard register containing the return value, not a
6781 temporary pseudo. */
6782 current_function_return_rtx = real_decl_rtl;
6786 /* If returning a structure, arrange to return the address of the value
6787 in a place where debuggers expect to find it.
6789 If returning a structure PCC style,
6790 the caller also depends on this value.
6791 And current_function_returns_pcc_struct is not necessarily set. */
6792 if (current_function_returns_struct
6793 || current_function_returns_pcc_struct)
6796 XEXP (DECL_RTL (DECL_RESULT (current_function_decl)), 0);
6797 tree type = TREE_TYPE (DECL_RESULT (current_function_decl));
6798 #ifdef FUNCTION_OUTGOING_VALUE
6800 = FUNCTION_OUTGOING_VALUE (build_pointer_type (type),
6801 current_function_decl);
6804 = FUNCTION_VALUE (build_pointer_type (type),
6805 current_function_decl);
6808 /* Mark this as a function return value so integrate will delete the
6809 assignment and USE below when inlining this function. */
6810 REG_FUNCTION_VALUE_P (outgoing) = 1;
6812 emit_move_insn (outgoing, value_address);
6815 /* ??? This should no longer be necessary since stupid is no longer with
6816 us, but there are some parts of the compiler (eg reload_combine, and
6817 sh mach_dep_reorg) that still try and compute their own lifetime info
6818 instead of using the general framework. */
6819 use_return_register ();
6821 /* If this is an implementation of __throw, do what's necessary to
6822 communicate between __builtin_eh_return and the epilogue. */
6823 expand_eh_return ();
6825 /* Output a return insn if we are using one.
6826 Otherwise, let the rtl chain end here, to drop through
6827 into the epilogue. */
6832 emit_jump_insn (gen_return ());
6837 /* Fix up any gotos that jumped out to the outermost
6838 binding level of the function.
6839 Must follow emitting RETURN_LABEL. */
6841 /* If you have any cleanups to do at this point,
6842 and they need to create temporary variables,
6843 then you will lose. */
6844 expand_fixups (get_insns ());
6847 /* Extend a vector that records the INSN_UIDs of INSNS (either a
6848 sequence or a single insn). */
6851 record_insns (insns, vecp)
6855 if (GET_CODE (insns) == SEQUENCE)
6857 int len = XVECLEN (insns, 0);
6858 int i = VARRAY_SIZE (*vecp);
6860 VARRAY_GROW (*vecp, i + len);
6863 VARRAY_INT (*vecp, i) = INSN_UID (XVECEXP (insns, 0, len));
6869 int i = VARRAY_SIZE (*vecp);
6870 VARRAY_GROW (*vecp, i + 1);
6871 VARRAY_INT (*vecp, i) = INSN_UID (insns);
6875 /* Determine how many INSN_UIDs in VEC are part of INSN. */
6878 contains (insn, vec)
6884 if (GET_CODE (insn) == INSN
6885 && GET_CODE (PATTERN (insn)) == SEQUENCE)
6888 for (i = XVECLEN (PATTERN (insn), 0) - 1; i >= 0; i--)
6889 for (j = VARRAY_SIZE (vec) - 1; j >= 0; --j)
6890 if (INSN_UID (XVECEXP (PATTERN (insn), 0, i)) == VARRAY_INT (vec, j))
6896 for (j = VARRAY_SIZE (vec) - 1; j >= 0; --j)
6897 if (INSN_UID (insn) == VARRAY_INT (vec, j))
6904 prologue_epilogue_contains (insn)
6907 if (contains (insn, prologue))
6909 if (contains (insn, epilogue))
6915 sibcall_epilogue_contains (insn)
6918 if (sibcall_epilogue)
6919 return contains (insn, sibcall_epilogue);
6924 /* Insert gen_return at the end of block BB. This also means updating
6925 block_for_insn appropriately. */
6928 emit_return_into_block (bb, line_note)
6934 p = NEXT_INSN (bb->end);
6935 end = emit_jump_insn_after (gen_return (), bb->end);
6937 emit_line_note_after (NOTE_SOURCE_FILE (line_note),
6938 NOTE_LINE_NUMBER (line_note), bb->end);
6942 set_block_for_insn (p, bb);
6949 #endif /* HAVE_return */
6951 #ifdef HAVE_epilogue
6953 /* Modify SEQ, a SEQUENCE that is part of the epilogue, to no modifications
6954 to the stack pointer. */
6957 keep_stack_depressed (seq)
6961 rtx sp_from_reg = 0;
6962 int sp_modified_unknown = 0;
6964 /* If the epilogue is just a single instruction, it's OK as is */
6966 if (GET_CODE (seq) != SEQUENCE) return;
6968 /* Scan all insns in SEQ looking for ones that modified the stack
6969 pointer. Record if it modified the stack pointer by copying it
6970 from the frame pointer or if it modified it in some other way.
6971 Then modify any subsequent stack pointer references to take that
6972 into account. We start by only allowing SP to be copied from a
6973 register (presumably FP) and then be subsequently referenced. */
6975 for (i = 0; i < XVECLEN (seq, 0); i++)
6977 rtx insn = XVECEXP (seq, 0, i);
6979 if (GET_RTX_CLASS (GET_CODE (insn)) != 'i')
6982 if (reg_set_p (stack_pointer_rtx, insn))
6984 rtx set = single_set (insn);
6986 /* If SP is set as a side-effect, we can't support this. */
6990 if (GET_CODE (SET_SRC (set)) == REG)
6991 sp_from_reg = SET_SRC (set);
6993 sp_modified_unknown = 1;
6995 /* Don't allow the SP modification to happen. */
6996 PUT_CODE (insn, NOTE);
6997 NOTE_LINE_NUMBER (insn) = NOTE_INSN_DELETED;
6998 NOTE_SOURCE_FILE (insn) = 0;
7000 else if (reg_referenced_p (stack_pointer_rtx, PATTERN (insn)))
7002 if (sp_modified_unknown)
7005 else if (sp_from_reg != 0)
7007 = replace_rtx (PATTERN (insn), stack_pointer_rtx, sp_from_reg);
7013 /* Generate the prologue and epilogue RTL if the machine supports it. Thread
7014 this into place with notes indicating where the prologue ends and where
7015 the epilogue begins. Update the basic block information when possible. */
7018 thread_prologue_and_epilogue_insns (f)
7019 rtx f ATTRIBUTE_UNUSED;
7024 #ifdef HAVE_prologue
7025 rtx prologue_end = NULL_RTX;
7027 #if defined (HAVE_epilogue) || defined(HAVE_return)
7028 rtx epilogue_end = NULL_RTX;
7031 #ifdef HAVE_prologue
7035 seq = gen_prologue ();
7038 /* Retain a map of the prologue insns. */
7039 if (GET_CODE (seq) != SEQUENCE)
7041 record_insns (seq, &prologue);
7042 prologue_end = emit_note (NULL, NOTE_INSN_PROLOGUE_END);
7044 seq = gen_sequence ();
7047 /* If optimization is off, and perhaps in an empty function,
7048 the entry block will have no successors. */
7049 if (ENTRY_BLOCK_PTR->succ)
7051 /* Can't deal with multiple successsors of the entry block. */
7052 if (ENTRY_BLOCK_PTR->succ->succ_next)
7055 insert_insn_on_edge (seq, ENTRY_BLOCK_PTR->succ);
7059 emit_insn_after (seq, f);
7063 /* If the exit block has no non-fake predecessors, we don't need
7065 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7066 if ((e->flags & EDGE_FAKE) == 0)
7072 if (optimize && HAVE_return)
7074 /* If we're allowed to generate a simple return instruction,
7075 then by definition we don't need a full epilogue. Examine
7076 the block that falls through to EXIT. If it does not
7077 contain any code, examine its predecessors and try to
7078 emit (conditional) return instructions. */
7084 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7085 if (e->flags & EDGE_FALLTHRU)
7091 /* Verify that there are no active instructions in the last block. */
7093 while (label && GET_CODE (label) != CODE_LABEL)
7095 if (active_insn_p (label))
7097 label = PREV_INSN (label);
7100 if (last->head == label && GET_CODE (label) == CODE_LABEL)
7102 rtx epilogue_line_note = NULL_RTX;
7104 /* Locate the line number associated with the closing brace,
7105 if we can find one. */
7106 for (seq = get_last_insn ();
7107 seq && ! active_insn_p (seq);
7108 seq = PREV_INSN (seq))
7109 if (GET_CODE (seq) == NOTE && NOTE_LINE_NUMBER (seq) > 0)
7111 epilogue_line_note = seq;
7115 for (e = last->pred; e; e = e_next)
7117 basic_block bb = e->src;
7120 e_next = e->pred_next;
7121 if (bb == ENTRY_BLOCK_PTR)
7125 if ((GET_CODE (jump) != JUMP_INSN) || JUMP_LABEL (jump) != label)
7128 /* If we have an unconditional jump, we can replace that
7129 with a simple return instruction. */
7130 if (simplejump_p (jump))
7132 emit_return_into_block (bb, epilogue_line_note);
7133 flow_delete_insn (jump);
7136 /* If we have a conditional jump, we can try to replace
7137 that with a conditional return instruction. */
7138 else if (condjump_p (jump))
7142 ret = SET_SRC (PATTERN (jump));
7143 if (GET_CODE (XEXP (ret, 1)) == LABEL_REF)
7144 loc = &XEXP (ret, 1);
7146 loc = &XEXP (ret, 2);
7147 ret = gen_rtx_RETURN (VOIDmode);
7149 if (! validate_change (jump, loc, ret, 0))
7151 if (JUMP_LABEL (jump))
7152 LABEL_NUSES (JUMP_LABEL (jump))--;
7154 /* If this block has only one successor, it both jumps
7155 and falls through to the fallthru block, so we can't
7157 if (bb->succ->succ_next == NULL)
7163 /* Fix up the CFG for the successful change we just made. */
7164 redirect_edge_succ (e, EXIT_BLOCK_PTR);
7167 /* Emit a return insn for the exit fallthru block. Whether
7168 this is still reachable will be determined later. */
7170 emit_barrier_after (last->end);
7171 emit_return_into_block (last, epilogue_line_note);
7172 epilogue_end = last->end;
7177 #ifdef HAVE_epilogue
7180 /* Find the edge that falls through to EXIT. Other edges may exist
7181 due to RETURN instructions, but those don't need epilogues.
7182 There really shouldn't be a mixture -- either all should have
7183 been converted or none, however... */
7185 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7186 if (e->flags & EDGE_FALLTHRU)
7192 epilogue_end = emit_note (NULL, NOTE_INSN_EPILOGUE_BEG);
7194 seq = gen_epilogue ();
7196 /* If this function returns with the stack depressed, massage
7197 the epilogue to actually do that. */
7198 if (TREE_CODE (TREE_TYPE (current_function_decl)) == FUNCTION_TYPE
7199 && TYPE_RETURNS_STACK_DEPRESSED (TREE_TYPE (current_function_decl)))
7200 keep_stack_depressed (seq);
7202 emit_jump_insn (seq);
7204 /* Retain a map of the epilogue insns. */
7205 if (GET_CODE (seq) != SEQUENCE)
7207 record_insns (seq, &epilogue);
7209 seq = gen_sequence ();
7212 insert_insn_on_edge (seq, e);
7219 commit_edge_insertions ();
7221 #ifdef HAVE_sibcall_epilogue
7222 /* Emit sibling epilogues before any sibling call sites. */
7223 for (e = EXIT_BLOCK_PTR->pred; e; e = e->pred_next)
7225 basic_block bb = e->src;
7230 if (GET_CODE (insn) != CALL_INSN
7231 || ! SIBLING_CALL_P (insn))
7235 seq = gen_sibcall_epilogue ();
7238 i = PREV_INSN (insn);
7239 newinsn = emit_insn_before (seq, insn);
7241 /* Update the UID to basic block map. */
7242 for (i = NEXT_INSN (i); i != insn; i = NEXT_INSN (i))
7243 set_block_for_insn (i, bb);
7245 /* Retain a map of the epilogue insns. Used in life analysis to
7246 avoid getting rid of sibcall epilogue insns. */
7247 record_insns (GET_CODE (seq) == SEQUENCE
7248 ? seq : newinsn, &sibcall_epilogue);
7252 #ifdef HAVE_prologue
7257 /* GDB handles `break f' by setting a breakpoint on the first
7258 line note after the prologue. Which means (1) that if
7259 there are line number notes before where we inserted the
7260 prologue we should move them, and (2) we should generate a
7261 note before the end of the first basic block, if there isn't
7262 one already there. */
7264 for (insn = prologue_end; insn; insn = prev)
7266 prev = PREV_INSN (insn);
7267 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
7269 /* Note that we cannot reorder the first insn in the
7270 chain, since rest_of_compilation relies on that
7271 remaining constant. */
7274 reorder_insns (insn, insn, prologue_end);
7278 /* Find the last line number note in the first block. */
7279 for (insn = BASIC_BLOCK (0)->end;
7280 insn != prologue_end;
7281 insn = PREV_INSN (insn))
7282 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
7285 /* If we didn't find one, make a copy of the first line number
7289 for (insn = next_active_insn (prologue_end);
7291 insn = PREV_INSN (insn))
7292 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
7294 emit_line_note_after (NOTE_SOURCE_FILE (insn),
7295 NOTE_LINE_NUMBER (insn),
7302 #ifdef HAVE_epilogue
7307 /* Similarly, move any line notes that appear after the epilogue.
7308 There is no need, however, to be quite so anal about the existance
7310 for (insn = epilogue_end; insn; insn = next)
7312 next = NEXT_INSN (insn);
7313 if (GET_CODE (insn) == NOTE && NOTE_LINE_NUMBER (insn) > 0)
7314 reorder_insns (insn, insn, PREV_INSN (epilogue_end));
7320 /* Reposition the prologue-end and epilogue-begin notes after instruction
7321 scheduling and delayed branch scheduling. */
7324 reposition_prologue_and_epilogue_notes (f)
7325 rtx f ATTRIBUTE_UNUSED;
7327 #if defined (HAVE_prologue) || defined (HAVE_epilogue)
7330 if ((len = VARRAY_SIZE (prologue)) > 0)
7332 register rtx insn, note = 0;
7334 /* Scan from the beginning until we reach the last prologue insn.
7335 We apparently can't depend on basic_block_{head,end} after
7337 for (insn = f; len && insn; insn = NEXT_INSN (insn))
7339 if (GET_CODE (insn) == NOTE)
7341 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_PROLOGUE_END)
7344 else if ((len -= contains (insn, prologue)) == 0)
7347 /* Find the prologue-end note if we haven't already, and
7348 move it to just after the last prologue insn. */
7351 for (note = insn; (note = NEXT_INSN (note));)
7352 if (GET_CODE (note) == NOTE
7353 && NOTE_LINE_NUMBER (note) == NOTE_INSN_PROLOGUE_END)
7357 next = NEXT_INSN (note);
7359 /* Whether or not we can depend on BLOCK_HEAD,
7360 attempt to keep it up-to-date. */
7361 if (BLOCK_HEAD (0) == note)
7362 BLOCK_HEAD (0) = next;
7365 add_insn_after (note, insn);
7370 if ((len = VARRAY_SIZE (epilogue)) > 0)
7372 register rtx insn, note = 0;
7374 /* Scan from the end until we reach the first epilogue insn.
7375 We apparently can't depend on basic_block_{head,end} after
7377 for (insn = get_last_insn (); len && insn; insn = PREV_INSN (insn))
7379 if (GET_CODE (insn) == NOTE)
7381 if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EPILOGUE_BEG)
7384 else if ((len -= contains (insn, epilogue)) == 0)
7386 /* Find the epilogue-begin note if we haven't already, and
7387 move it to just before the first epilogue insn. */
7390 for (note = insn; (note = PREV_INSN (note));)
7391 if (GET_CODE (note) == NOTE
7392 && NOTE_LINE_NUMBER (note) == NOTE_INSN_EPILOGUE_BEG)
7396 /* Whether or not we can depend on BLOCK_HEAD,
7397 attempt to keep it up-to-date. */
7399 && BLOCK_HEAD (n_basic_blocks-1) == insn)
7400 BLOCK_HEAD (n_basic_blocks-1) = note;
7403 add_insn_before (note, insn);
7407 #endif /* HAVE_prologue or HAVE_epilogue */
7410 /* Mark T for GC. */
7414 struct temp_slot *t;
7418 ggc_mark_rtx (t->slot);
7419 ggc_mark_rtx (t->address);
7420 ggc_mark_tree (t->rtl_expr);
7426 /* Mark P for GC. */
7429 mark_function_status (p)
7438 ggc_mark_rtx (p->arg_offset_rtx);
7440 if (p->x_parm_reg_stack_loc)
7441 for (i = p->x_max_parm_reg, r = p->x_parm_reg_stack_loc;
7445 ggc_mark_rtx (p->return_rtx);
7446 ggc_mark_rtx (p->x_cleanup_label);
7447 ggc_mark_rtx (p->x_return_label);
7448 ggc_mark_rtx (p->x_save_expr_regs);
7449 ggc_mark_rtx (p->x_stack_slot_list);
7450 ggc_mark_rtx (p->x_parm_birth_insn);
7451 ggc_mark_rtx (p->x_tail_recursion_label);
7452 ggc_mark_rtx (p->x_tail_recursion_reentry);
7453 ggc_mark_rtx (p->internal_arg_pointer);
7454 ggc_mark_rtx (p->x_arg_pointer_save_area);
7455 ggc_mark_tree (p->x_rtl_expr_chain);
7456 ggc_mark_rtx (p->x_last_parm_insn);
7457 ggc_mark_tree (p->x_context_display);
7458 ggc_mark_tree (p->x_trampoline_list);
7459 ggc_mark_rtx (p->epilogue_delay_list);
7460 ggc_mark_rtx (p->x_clobber_return_insn);
7462 mark_temp_slot (p->x_temp_slots);
7465 struct var_refs_queue *q = p->fixup_var_refs_queue;
7468 ggc_mark_rtx (q->modified);
7473 ggc_mark_rtx (p->x_nonlocal_goto_handler_slots);
7474 ggc_mark_rtx (p->x_nonlocal_goto_handler_labels);
7475 ggc_mark_rtx (p->x_nonlocal_goto_stack_level);
7476 ggc_mark_tree (p->x_nonlocal_labels);
7479 /* Mark the function chain ARG (which is really a struct function **)
7483 mark_function_chain (arg)
7486 struct function *f = *(struct function **) arg;
7488 for (; f; f = f->next_global)
7490 ggc_mark_tree (f->decl);
7492 mark_function_status (f);
7493 mark_eh_status (f->eh);
7494 mark_stmt_status (f->stmt);
7495 mark_expr_status (f->expr);
7496 mark_emit_status (f->emit);
7497 mark_varasm_status (f->varasm);
7499 if (mark_machine_status)
7500 (*mark_machine_status) (f);
7501 if (mark_lang_status)
7502 (*mark_lang_status) (f);
7504 if (f->original_arg_vector)
7505 ggc_mark_rtvec ((rtvec) f->original_arg_vector);
7506 if (f->original_decl_initial)
7507 ggc_mark_tree (f->original_decl_initial);
7511 /* Called once, at initialization, to initialize function.c. */
7514 init_function_once ()
7516 ggc_add_root (&all_functions, 1, sizeof all_functions,
7517 mark_function_chain);
7519 VARRAY_INT_INIT (prologue, 0, "prologue");
7520 VARRAY_INT_INIT (epilogue, 0, "epilogue");
7521 VARRAY_INT_INIT (sibcall_epilogue, 0, "sibcall_epilogue");