1 /* Register renaming for the GNU compiler.
2 Copyright (C) 2000, 2001, 2002 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GCC is distributed in the hope that it will be useful, but WITHOUT
12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
14 License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING. If not, write to the Free
18 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
27 #include "insn-config.h"
29 #include "hard-reg-set.h"
30 #include "basic-block.h"
39 #define obstack_chunk_alloc xmalloc
40 #define obstack_chunk_free free
42 #ifndef REGNO_MODE_OK_FOR_BASE_P
43 #define REGNO_MODE_OK_FOR_BASE_P(REGNO, MODE) REGNO_OK_FOR_BASE_P (REGNO)
46 #ifndef REG_MODE_OK_FOR_BASE_P
47 #define REG_MODE_OK_FOR_BASE_P(REGNO, MODE) REG_OK_FOR_BASE_P (REGNO)
50 static const char *const reg_class_names
[] = REG_CLASS_NAMES
;
54 struct du_chain
*next_chain
;
55 struct du_chain
*next_use
;
60 unsigned int need_caller_save_reg
:1;
61 unsigned int earlyclobber
:1;
67 terminate_overlapping_read
,
74 static const char * const scan_actions_name
[] =
77 "terminate_overlapping_read",
84 static struct obstack rename_obstack
;
86 static void do_replace
PARAMS ((struct du_chain
*, int));
87 static void scan_rtx_reg
PARAMS ((rtx
, rtx
*, enum reg_class
,
88 enum scan_actions
, enum op_type
, int));
89 static void scan_rtx_address
PARAMS ((rtx
, rtx
*, enum reg_class
,
90 enum scan_actions
, enum machine_mode
));
91 static void scan_rtx
PARAMS ((rtx
, rtx
*, enum reg_class
,
92 enum scan_actions
, enum op_type
, int));
93 static struct du_chain
*build_def_use
PARAMS ((basic_block
));
94 static void dump_def_use_chain
PARAMS ((struct du_chain
*));
95 static void note_sets
PARAMS ((rtx
, rtx
, void *));
96 static void clear_dead_regs
PARAMS ((HARD_REG_SET
*, enum machine_mode
, rtx
));
97 static void merge_overlapping_regs
PARAMS ((basic_block
, HARD_REG_SET
*,
100 /* Called through note_stores from update_life. Find sets of registers, and
101 record them in *DATA (which is actually a HARD_REG_SET *). */
104 note_sets (x
, set
, data
)
106 rtx set ATTRIBUTE_UNUSED
;
109 HARD_REG_SET
*pset
= (HARD_REG_SET
*) data
;
112 if (GET_CODE (x
) != REG
)
115 nregs
= HARD_REGNO_NREGS (regno
, GET_MODE (x
));
117 /* There must not be pseudos at this point. */
118 if (regno
+ nregs
> FIRST_PSEUDO_REGISTER
)
122 SET_HARD_REG_BIT (*pset
, regno
+ nregs
);
125 /* Clear all registers from *PSET for which a note of kind KIND can be found
126 in the list NOTES. */
129 clear_dead_regs (pset
, kind
, notes
)
131 enum machine_mode kind
;
135 for (note
= notes
; note
; note
= XEXP (note
, 1))
136 if (REG_NOTE_KIND (note
) == kind
&& REG_P (XEXP (note
, 0)))
138 rtx reg
= XEXP (note
, 0);
139 unsigned int regno
= REGNO (reg
);
140 int nregs
= HARD_REGNO_NREGS (regno
, GET_MODE (reg
));
142 /* There must not be pseudos at this point. */
143 if (regno
+ nregs
> FIRST_PSEUDO_REGISTER
)
147 CLEAR_HARD_REG_BIT (*pset
, regno
+ nregs
);
151 /* For a def-use chain CHAIN in basic block B, find which registers overlap
152 its lifetime and set the corresponding bits in *PSET. */
155 merge_overlapping_regs (b
, pset
, chain
)
158 struct du_chain
*chain
;
160 struct du_chain
*t
= chain
;
164 REG_SET_TO_HARD_REG_SET (live
, b
->global_live_at_start
);
168 /* Search forward until the next reference to the register to be
170 while (insn
!= t
->insn
)
174 clear_dead_regs (&live
, REG_DEAD
, REG_NOTES (insn
));
175 note_stores (PATTERN (insn
), note_sets
, (void *) &live
);
176 /* Only record currently live regs if we are inside the
179 IOR_HARD_REG_SET (*pset
, live
);
180 clear_dead_regs (&live
, REG_UNUSED
, REG_NOTES (insn
));
182 insn
= NEXT_INSN (insn
);
185 IOR_HARD_REG_SET (*pset
, live
);
187 /* For the last reference, also merge in all registers set in the
189 @@@ We only have take earlyclobbered sets into account. */
191 note_stores (PATTERN (insn
), note_sets
, (void *) pset
);
197 /* Perform register renaming on the current function. */
200 regrename_optimize ()
202 int tick
[FIRST_PSEUDO_REGISTER
];
207 memset (tick
, 0, sizeof tick
);
209 gcc_obstack_init (&rename_obstack
);
210 first_obj
= (char *) obstack_alloc (&rename_obstack
, 0);
212 for (b
= 0; b
< n_basic_blocks
; b
++)
214 basic_block bb
= BASIC_BLOCK (b
);
215 struct du_chain
*all_chains
= 0;
216 HARD_REG_SET unavailable
;
217 HARD_REG_SET regs_seen
;
219 CLEAR_HARD_REG_SET (unavailable
);
222 fprintf (rtl_dump_file
, "\nBasic block %d:\n", b
);
224 all_chains
= build_def_use (bb
);
227 dump_def_use_chain (all_chains
);
229 CLEAR_HARD_REG_SET (unavailable
);
230 /* Don't clobber traceback for noreturn functions. */
231 if (frame_pointer_needed
)
235 for (i
= HARD_REGNO_NREGS (FRAME_POINTER_REGNUM
, Pmode
); i
--;)
236 SET_HARD_REG_BIT (unavailable
, FRAME_POINTER_REGNUM
+ i
);
238 #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
239 for (i
= HARD_REGNO_NREGS (HARD_FRAME_POINTER_REGNUM
, Pmode
); i
--;)
240 SET_HARD_REG_BIT (unavailable
, HARD_FRAME_POINTER_REGNUM
+ i
);
244 CLEAR_HARD_REG_SET (regs_seen
);
247 int new_reg
, best_new_reg
= -1;
249 struct du_chain
*this = all_chains
;
250 struct du_chain
*tmp
, *last
;
251 HARD_REG_SET this_unavailable
;
252 int reg
= REGNO (*this->loc
);
255 all_chains
= this->next_chain
;
257 #if 0 /* This just disables optimization opportunities. */
258 /* Only rename once we've seen the reg more than once. */
259 if (! TEST_HARD_REG_BIT (regs_seen
, reg
))
261 SET_HARD_REG_BIT (regs_seen
, reg
);
266 if (fixed_regs
[reg
] || global_regs
[reg
]
267 #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
268 || (frame_pointer_needed
&& reg
== HARD_FRAME_POINTER_REGNUM
)
270 || (frame_pointer_needed
&& reg
== FRAME_POINTER_REGNUM
)
275 COPY_HARD_REG_SET (this_unavailable
, unavailable
);
277 /* Find last entry on chain (which has the need_caller_save bit),
278 count number of uses, and narrow the set of registers we can
281 for (last
= this; last
->next_use
; last
= last
->next_use
)
284 IOR_COMPL_HARD_REG_SET (this_unavailable
,
285 reg_class_contents
[last
->class]);
290 IOR_COMPL_HARD_REG_SET (this_unavailable
,
291 reg_class_contents
[last
->class]);
293 if (this->need_caller_save_reg
)
294 IOR_HARD_REG_SET (this_unavailable
, call_used_reg_set
);
296 merge_overlapping_regs (bb
, &this_unavailable
, this);
298 /* Now potential_regs is a reasonable approximation, let's
299 have a closer look at each register still in there. */
300 for (new_reg
= 0; new_reg
< FIRST_PSEUDO_REGISTER
; new_reg
++)
302 int nregs
= HARD_REGNO_NREGS (new_reg
, GET_MODE (*this->loc
));
304 for (i
= nregs
- 1; i
>= 0; --i
)
305 if (TEST_HARD_REG_BIT (this_unavailable
, new_reg
+ i
)
306 || fixed_regs
[new_reg
+ i
]
307 || global_regs
[new_reg
+ i
]
308 /* Can't use regs which aren't saved by the prologue. */
309 || (! regs_ever_live
[new_reg
+ i
]
310 && ! call_used_regs
[new_reg
+ i
])
311 #ifdef LEAF_REGISTERS
312 /* We can't use a non-leaf register if we're in a
314 || (current_function_is_leaf
315 && !LEAF_REGISTERS
[new_reg
+ i
])
317 #ifdef HARD_REGNO_RENAME_OK
318 || ! HARD_REGNO_RENAME_OK (reg
+ i
, new_reg
+ i
)
325 /* See whether it accepts all modes that occur in
326 definition and uses. */
327 for (tmp
= this; tmp
; tmp
= tmp
->next_use
)
328 if (! HARD_REGNO_MODE_OK (new_reg
, GET_MODE (*tmp
->loc
))
329 || (tmp
->need_caller_save_reg
330 && ! (HARD_REGNO_CALL_PART_CLOBBERED
331 (reg
, GET_MODE (*tmp
->loc
)))
332 && (HARD_REGNO_CALL_PART_CLOBBERED
333 (new_reg
, GET_MODE (*tmp
->loc
)))))
337 if (best_new_reg
== -1
338 || tick
[best_new_reg
] > tick
[new_reg
])
339 best_new_reg
= new_reg
;
345 fprintf (rtl_dump_file
, "Register %s in insn %d",
346 reg_names
[reg
], INSN_UID (last
->insn
));
347 if (last
->need_caller_save_reg
)
348 fprintf (rtl_dump_file
, " crosses a call");
351 if (best_new_reg
== -1)
354 fprintf (rtl_dump_file
, "; no available registers\n");
358 do_replace (this, best_new_reg
);
359 tick
[best_new_reg
] = this_tick
++;
362 fprintf (rtl_dump_file
, ", renamed as %s\n", reg_names
[best_new_reg
]);
365 obstack_free (&rename_obstack
, first_obj
);
368 obstack_free (&rename_obstack
, NULL
);
371 fputc ('\n', rtl_dump_file
);
373 count_or_remove_death_notes (NULL
, 1);
374 update_life_info (NULL
, UPDATE_LIFE_LOCAL
,
375 PROP_REG_INFO
| PROP_DEATH_NOTES
);
379 do_replace (chain
, reg
)
380 struct du_chain
*chain
;
385 unsigned int regno
= ORIGINAL_REGNO (*chain
->loc
);
386 *chain
->loc
= gen_raw_REG (GET_MODE (*chain
->loc
), reg
);
387 if (regno
>= FIRST_PSEUDO_REGISTER
)
388 ORIGINAL_REGNO (*chain
->loc
) = regno
;
389 chain
= chain
->next_use
;
394 static struct du_chain
*open_chains
;
395 static struct du_chain
*closed_chains
;
398 scan_rtx_reg (insn
, loc
, class, action
, type
, earlyclobber
)
401 enum reg_class
class;
402 enum scan_actions action
;
408 enum machine_mode mode
= GET_MODE (x
);
409 int this_regno
= REGNO (x
);
410 int this_nregs
= HARD_REGNO_NREGS (this_regno
, mode
);
412 if (action
== mark_write
)
416 struct du_chain
*this = (struct du_chain
*)
417 obstack_alloc (&rename_obstack
, sizeof (struct du_chain
));
419 this->next_chain
= open_chains
;
423 this->need_caller_save_reg
= 0;
424 this->earlyclobber
= earlyclobber
;
430 if ((type
== OP_OUT
&& action
!= terminate_write
)
431 || (type
!= OP_OUT
&& action
== terminate_write
))
434 for (p
= &open_chains
; *p
;)
436 struct du_chain
*this = *p
;
438 /* Check if the chain has been terminated if it has then skip to
441 This can happen when we've already appended the location to
442 the chain in Step 3, but are trying to hide in-out operands
443 from terminate_write in Step 5. */
445 if (*this->loc
== cc0_rtx
)
446 p
= &this->next_chain
;
449 int regno
= REGNO (*this->loc
);
450 int nregs
= HARD_REGNO_NREGS (regno
, GET_MODE (*this->loc
));
451 int exact_match
= (regno
== this_regno
&& nregs
== this_nregs
);
453 if (regno
+ nregs
<= this_regno
454 || this_regno
+ this_nregs
<= regno
)
456 p
= &this->next_chain
;
460 if (action
== mark_read
)
465 /* ??? Class NO_REGS can happen if the md file makes use of
466 EXTRA_CONSTRAINTS to match registers. Which is arguably
467 wrong, but there we are. Since we know not what this may
468 be replaced with, terminate the chain. */
469 if (class != NO_REGS
)
471 this = (struct du_chain
*)
472 obstack_alloc (&rename_obstack
, sizeof (struct du_chain
));
474 this->next_chain
= (*p
)->next_chain
;
478 this->need_caller_save_reg
= 0;
486 if (action
!= terminate_overlapping_read
|| ! exact_match
)
488 struct du_chain
*next
= this->next_chain
;
490 /* Whether the terminated chain can be used for renaming
491 depends on the action and this being an exact match.
492 In either case, we remove this element from open_chains. */
494 if ((action
== terminate_dead
|| action
== terminate_write
)
497 this->next_chain
= closed_chains
;
498 closed_chains
= this;
500 fprintf (rtl_dump_file
,
501 "Closing chain %s at insn %d (%s)\n",
502 reg_names
[REGNO (*this->loc
)], INSN_UID (insn
),
503 scan_actions_name
[(int) action
]);
508 fprintf (rtl_dump_file
,
509 "Discarding chain %s at insn %d (%s)\n",
510 reg_names
[REGNO (*this->loc
)], INSN_UID (insn
),
511 scan_actions_name
[(int) action
]);
516 p
= &this->next_chain
;
521 /* Adapted from find_reloads_address_1. CLASS is INDEX_REG_CLASS or
522 BASE_REG_CLASS depending on how the register is being considered. */
525 scan_rtx_address (insn
, loc
, class, action
, mode
)
528 enum reg_class
class;
529 enum scan_actions action
;
530 enum machine_mode mode
;
533 RTX_CODE code
= GET_CODE (x
);
537 if (action
== mark_write
)
544 rtx orig_op0
= XEXP (x
, 0);
545 rtx orig_op1
= XEXP (x
, 1);
546 RTX_CODE code0
= GET_CODE (orig_op0
);
547 RTX_CODE code1
= GET_CODE (orig_op1
);
553 if (GET_CODE (op0
) == SUBREG
)
555 op0
= SUBREG_REG (op0
);
556 code0
= GET_CODE (op0
);
559 if (GET_CODE (op1
) == SUBREG
)
561 op1
= SUBREG_REG (op1
);
562 code1
= GET_CODE (op1
);
565 if (code0
== MULT
|| code0
== SIGN_EXTEND
|| code0
== TRUNCATE
566 || code0
== ZERO_EXTEND
|| code1
== MEM
)
571 else if (code1
== MULT
|| code1
== SIGN_EXTEND
|| code1
== TRUNCATE
572 || code1
== ZERO_EXTEND
|| code0
== MEM
)
577 else if (code0
== CONST_INT
|| code0
== CONST
578 || code0
== SYMBOL_REF
|| code0
== LABEL_REF
)
580 else if (code1
== CONST_INT
|| code1
== CONST
581 || code1
== SYMBOL_REF
|| code1
== LABEL_REF
)
583 else if (code0
== REG
&& code1
== REG
)
587 if (REG_OK_FOR_INDEX_P (op0
)
588 && REG_MODE_OK_FOR_BASE_P (op1
, mode
))
590 else if (REG_OK_FOR_INDEX_P (op1
)
591 && REG_MODE_OK_FOR_BASE_P (op0
, mode
))
593 else if (REG_MODE_OK_FOR_BASE_P (op1
, mode
))
595 else if (REG_MODE_OK_FOR_BASE_P (op0
, mode
))
597 else if (REG_OK_FOR_INDEX_P (op1
))
602 locI
= &XEXP (x
, index_op
);
603 locB
= &XEXP (x
, !index_op
);
605 else if (code0
== REG
)
610 else if (code1
== REG
)
617 scan_rtx_address (insn
, locI
, INDEX_REG_CLASS
, action
, mode
);
619 scan_rtx_address (insn
, locB
, MODE_BASE_REG_CLASS (mode
), action
, mode
);
630 /* If the target doesn't claim to handle autoinc, this must be
631 something special, like a stack push. Kill this chain. */
632 action
= terminate_all_read
;
637 scan_rtx_address (insn
, &XEXP (x
, 0),
638 MODE_BASE_REG_CLASS (GET_MODE (x
)), action
,
643 scan_rtx_reg (insn
, loc
, class, action
, OP_IN
, 0);
650 fmt
= GET_RTX_FORMAT (code
);
651 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
654 scan_rtx_address (insn
, &XEXP (x
, i
), class, action
, mode
);
655 else if (fmt
[i
] == 'E')
656 for (j
= XVECLEN (x
, i
) - 1; j
>= 0; j
--)
657 scan_rtx_address (insn
, &XVECEXP (x
, i
, j
), class, action
, mode
);
662 scan_rtx (insn
, loc
, class, action
, type
, earlyclobber
)
665 enum reg_class
class;
666 enum scan_actions action
;
672 enum rtx_code code
= GET_CODE (x
);
688 scan_rtx_reg (insn
, loc
, class, action
, type
, earlyclobber
);
692 scan_rtx_address (insn
, &XEXP (x
, 0),
693 MODE_BASE_REG_CLASS (GET_MODE (x
)), action
,
698 scan_rtx (insn
, &SET_SRC (x
), class, action
, OP_IN
, 0);
699 scan_rtx (insn
, &SET_DEST (x
), class, action
, OP_OUT
, 0);
702 case STRICT_LOW_PART
:
703 scan_rtx (insn
, &XEXP (x
, 0), class, action
, OP_INOUT
, earlyclobber
);
708 scan_rtx (insn
, &XEXP (x
, 0), class, action
,
709 type
== OP_IN
? OP_IN
: OP_INOUT
, earlyclobber
);
710 scan_rtx (insn
, &XEXP (x
, 1), class, action
, OP_IN
, 0);
711 scan_rtx (insn
, &XEXP (x
, 2), class, action
, OP_IN
, 0);
720 /* Should only happen inside MEM. */
724 scan_rtx (insn
, &SET_DEST (x
), class, action
, OP_OUT
, 1);
728 scan_rtx (insn
, &XEXP (x
, 0), class, action
, type
, 0);
730 scan_rtx (insn
, &XEXP (x
, 1), class, action
, type
, 0);
737 fmt
= GET_RTX_FORMAT (code
);
738 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
741 scan_rtx (insn
, &XEXP (x
, i
), class, action
, type
, 0);
742 else if (fmt
[i
] == 'E')
743 for (j
= XVECLEN (x
, i
) - 1; j
>= 0; j
--)
744 scan_rtx (insn
, &XVECEXP (x
, i
, j
), class, action
, type
, 0);
748 /* Build def/use chain */
750 static struct du_chain
*
756 open_chains
= closed_chains
= NULL
;
758 for (insn
= bb
->head
; ; insn
= NEXT_INSN (insn
))
764 rtx old_operands
[MAX_RECOG_OPERANDS
];
765 rtx old_dups
[MAX_DUP_OPERANDS
];
770 /* Process the insn, determining its effect on the def-use
771 chains. We perform the following steps with the register
772 references in the insn:
773 (1) Any read that overlaps an open chain, but doesn't exactly
774 match, causes that chain to be closed. We can't deal
776 (2) Any read outside an operand causes any chain it overlaps
777 with to be closed, since we can't replace it.
778 (3) Any read inside an operand is added if there's already
779 an open chain for it.
780 (4) For any REG_DEAD note we find, close open chains that
782 (5) For any write we find, close open chains that overlap it.
783 (6) For any write we find in an operand, make a new chain.
784 (7) For any REG_UNUSED, close any chains we just opened. */
787 constrain_operands (1);
788 preprocess_constraints ();
789 alt
= which_alternative
;
790 n_ops
= recog_data
.n_operands
;
792 /* Simplify the code below by rewriting things to reflect
793 matching constraints. Also promote OP_OUT to OP_INOUT
794 in predicated instructions. */
796 predicated
= GET_CODE (PATTERN (insn
)) == COND_EXEC
;
797 for (i
= 0; i
< n_ops
; ++i
)
799 int matches
= recog_op_alt
[i
][alt
].matches
;
801 recog_op_alt
[i
][alt
].class = recog_op_alt
[matches
][alt
].class;
802 if (matches
>= 0 || recog_op_alt
[i
][alt
].matched
>= 0
803 || (predicated
&& recog_data
.operand_type
[i
] == OP_OUT
))
804 recog_data
.operand_type
[i
] = OP_INOUT
;
807 /* Step 1: Close chains for which we have overlapping reads. */
808 for (i
= 0; i
< n_ops
; i
++)
809 scan_rtx (insn
, recog_data
.operand_loc
[i
],
810 NO_REGS
, terminate_overlapping_read
,
811 recog_data
.operand_type
[i
], 0);
813 /* Step 2: Close chains for which we have reads outside operands.
814 We do this by munging all operands into CC0, and closing
815 everything remaining. */
817 for (i
= 0; i
< n_ops
; i
++)
819 old_operands
[i
] = recog_data
.operand
[i
];
820 /* Don't squash match_operator or match_parallel here, since
821 we don't know that all of the contained registers are
822 reachable by proper operands. */
823 if (recog_data
.constraints
[i
][0] == '\0')
825 *recog_data
.operand_loc
[i
] = cc0_rtx
;
827 for (i
= 0; i
< recog_data
.n_dups
; i
++)
829 old_dups
[i
] = *recog_data
.dup_loc
[i
];
830 *recog_data
.dup_loc
[i
] = cc0_rtx
;
833 scan_rtx (insn
, &PATTERN (insn
), NO_REGS
, terminate_all_read
,
836 for (i
= 0; i
< recog_data
.n_dups
; i
++)
837 *recog_data
.dup_loc
[i
] = old_dups
[i
];
838 for (i
= 0; i
< n_ops
; i
++)
839 *recog_data
.operand_loc
[i
] = old_operands
[i
];
841 /* Step 2B: Can't rename function call argument registers. */
842 if (GET_CODE (insn
) == CALL_INSN
&& CALL_INSN_FUNCTION_USAGE (insn
))
843 scan_rtx (insn
, &CALL_INSN_FUNCTION_USAGE (insn
),
844 NO_REGS
, terminate_all_read
, OP_IN
, 0);
846 /* Step 2C: Can't rename asm operands that were originally
848 if (asm_noperands (PATTERN (insn
)) > 0)
849 for (i
= 0; i
< n_ops
; i
++)
851 rtx
*loc
= recog_data
.operand_loc
[i
];
854 if (GET_CODE (op
) == REG
855 && REGNO (op
) == ORIGINAL_REGNO (op
)
856 && (recog_data
.operand_type
[i
] == OP_IN
857 || recog_data
.operand_type
[i
] == OP_INOUT
))
858 scan_rtx (insn
, loc
, NO_REGS
, terminate_all_read
, OP_IN
, 0);
861 /* Step 3: Append to chains for reads inside operands. */
862 for (i
= 0; i
< n_ops
+ recog_data
.n_dups
; i
++)
864 int opn
= i
< n_ops
? i
: recog_data
.dup_num
[i
- n_ops
];
865 rtx
*loc
= (i
< n_ops
866 ? recog_data
.operand_loc
[opn
]
867 : recog_data
.dup_loc
[i
- n_ops
]);
868 enum reg_class
class = recog_op_alt
[opn
][alt
].class;
869 enum op_type type
= recog_data
.operand_type
[opn
];
871 /* Don't scan match_operand here, since we've no reg class
872 information to pass down. Any operands that we could
873 substitute in will be represented elsewhere. */
874 if (recog_data
.constraints
[opn
][0] == '\0')
877 if (recog_op_alt
[opn
][alt
].is_address
)
878 scan_rtx_address (insn
, loc
, class, mark_read
, VOIDmode
);
880 scan_rtx (insn
, loc
, class, mark_read
, type
, 0);
883 /* Step 4: Close chains for registers that die here.
884 Also record updates for REG_INC notes. */
885 for (note
= REG_NOTES (insn
); note
; note
= XEXP (note
, 1))
887 if (REG_NOTE_KIND (note
) == REG_DEAD
)
888 scan_rtx (insn
, &XEXP (note
, 0), NO_REGS
, terminate_dead
,
890 else if (REG_NOTE_KIND (note
) == REG_INC
)
891 scan_rtx (insn
, &XEXP (note
, 0), ALL_REGS
, mark_read
,
895 /* Step 4B: If this is a call, any chain live at this point
896 requires a caller-saved reg. */
897 if (GET_CODE (insn
) == CALL_INSN
)
900 for (p
= open_chains
; p
; p
= p
->next_chain
)
901 p
->need_caller_save_reg
= 1;
904 /* Step 5: Close open chains that overlap writes. Similar to
905 step 2, we hide in-out operands, since we do not want to
906 close these chains. */
908 for (i
= 0; i
< n_ops
; i
++)
910 old_operands
[i
] = recog_data
.operand
[i
];
911 if (recog_data
.operand_type
[i
] == OP_INOUT
)
912 *recog_data
.operand_loc
[i
] = cc0_rtx
;
914 for (i
= 0; i
< recog_data
.n_dups
; i
++)
916 int opn
= recog_data
.dup_num
[i
];
917 old_dups
[i
] = *recog_data
.dup_loc
[i
];
918 if (recog_data
.operand_type
[opn
] == OP_INOUT
)
919 *recog_data
.dup_loc
[i
] = cc0_rtx
;
922 scan_rtx (insn
, &PATTERN (insn
), NO_REGS
, terminate_write
, OP_IN
, 0);
924 for (i
= 0; i
< recog_data
.n_dups
; i
++)
925 *recog_data
.dup_loc
[i
] = old_dups
[i
];
926 for (i
= 0; i
< n_ops
; i
++)
927 *recog_data
.operand_loc
[i
] = old_operands
[i
];
929 /* Step 6: Begin new chains for writes inside operands. */
930 /* ??? Many targets have output constraints on the SET_DEST
931 of a call insn, which is stupid, since these are certainly
932 ABI defined hard registers. Don't change calls at all.
933 Similarly take special care for asm statement that originally
934 referenced hard registers. */
935 if (asm_noperands (PATTERN (insn
)) > 0)
937 for (i
= 0; i
< n_ops
; i
++)
938 if (recog_data
.operand_type
[i
] == OP_OUT
)
940 rtx
*loc
= recog_data
.operand_loc
[i
];
942 enum reg_class
class = recog_op_alt
[i
][alt
].class;
944 if (GET_CODE (op
) == REG
945 && REGNO (op
) == ORIGINAL_REGNO (op
))
948 scan_rtx (insn
, loc
, class, mark_write
, OP_OUT
,
949 recog_op_alt
[i
][alt
].earlyclobber
);
952 else if (GET_CODE (insn
) != CALL_INSN
)
953 for (i
= 0; i
< n_ops
+ recog_data
.n_dups
; i
++)
955 int opn
= i
< n_ops
? i
: recog_data
.dup_num
[i
- n_ops
];
956 rtx
*loc
= (i
< n_ops
957 ? recog_data
.operand_loc
[opn
]
958 : recog_data
.dup_loc
[i
- n_ops
]);
959 enum reg_class
class = recog_op_alt
[opn
][alt
].class;
961 if (recog_data
.operand_type
[opn
] == OP_OUT
)
962 scan_rtx (insn
, loc
, class, mark_write
, OP_OUT
,
963 recog_op_alt
[opn
][alt
].earlyclobber
);
966 /* Step 7: Close chains for registers that were never
968 for (note
= REG_NOTES (insn
); note
; note
= XEXP (note
, 1))
969 if (REG_NOTE_KIND (note
) == REG_UNUSED
)
970 scan_rtx (insn
, &XEXP (note
, 0), NO_REGS
, terminate_dead
,
977 /* Since we close every chain when we find a REG_DEAD note, anything that
978 is still open lives past the basic block, so it can't be renamed. */
979 return closed_chains
;
982 /* Dump all def/use chains in CHAINS to RTL_DUMP_FILE. They are
983 printed in reverse order as that's how we build them. */
986 dump_def_use_chain (chains
)
987 struct du_chain
*chains
;
991 struct du_chain
*this = chains
;
992 int r
= REGNO (*this->loc
);
993 int nregs
= HARD_REGNO_NREGS (r
, GET_MODE (*this->loc
));
994 fprintf (rtl_dump_file
, "Register %s (%d):", reg_names
[r
], nregs
);
997 fprintf (rtl_dump_file
, " %d [%s]", INSN_UID (this->insn
),
998 reg_class_names
[this->class]);
999 this = this->next_use
;
1001 fprintf (rtl_dump_file
, "\n");
1002 chains
= chains
->next_chain
;
1006 /* The following code does forward propagation of hard register copies.
1007 The object is to eliminate as many dependencies as possible, so that
1008 we have the most scheduling freedom. As a side effect, we also clean
1009 up some silly register allocation decisions made by reload. This
1010 code may be obsoleted by a new register allocator. */
1012 /* For each register, we have a list of registers that contain the same
1013 value. The OLDEST_REGNO field points to the head of the list, and
1014 the NEXT_REGNO field runs through the list. The MODE field indicates
1015 what mode the data is known to be in; this field is VOIDmode when the
1016 register is not known to contain valid data. */
1018 struct value_data_entry
1020 enum machine_mode mode
;
1021 unsigned int oldest_regno
;
1022 unsigned int next_regno
;
1027 struct value_data_entry e
[FIRST_PSEUDO_REGISTER
];
1028 unsigned int max_value_regs
;
1031 static void kill_value_regno
PARAMS ((unsigned, struct value_data
*));
1032 static void kill_value
PARAMS ((rtx
, struct value_data
*));
1033 static void set_value_regno
PARAMS ((unsigned, enum machine_mode
,
1034 struct value_data
*));
1035 static void init_value_data
PARAMS ((struct value_data
*));
1036 static void kill_clobbered_value
PARAMS ((rtx
, rtx
, void *));
1037 static void kill_set_value
PARAMS ((rtx
, rtx
, void *));
1038 static int kill_autoinc_value
PARAMS ((rtx
*, void *));
1039 static void copy_value
PARAMS ((rtx
, rtx
, struct value_data
*));
1040 static bool mode_change_ok
PARAMS ((enum machine_mode
, enum machine_mode
,
1042 static rtx find_oldest_value_reg
PARAMS ((enum reg_class
, rtx
,
1043 struct value_data
*));
1044 static bool replace_oldest_value_reg
PARAMS ((rtx
*, enum reg_class
, rtx
,
1045 struct value_data
*));
1046 static bool replace_oldest_value_addr
PARAMS ((rtx
*, enum reg_class
,
1047 enum machine_mode
, rtx
,
1048 struct value_data
*));
1049 static bool replace_oldest_value_mem
PARAMS ((rtx
, rtx
, struct value_data
*));
1050 static bool copyprop_hardreg_forward_1
PARAMS ((basic_block
,
1051 struct value_data
*));
1052 extern void debug_value_data
PARAMS ((struct value_data
*));
1053 #ifdef ENABLE_CHECKING
1054 static void validate_value_data
PARAMS ((struct value_data
*));
1057 /* Kill register REGNO. This involves removing it from any value lists,
1058 and resetting the value mode to VOIDmode. */
1061 kill_value_regno (regno
, vd
)
1063 struct value_data
*vd
;
1065 unsigned int i
, next
;
1067 if (vd
->e
[regno
].oldest_regno
!= regno
)
1069 for (i
= vd
->e
[regno
].oldest_regno
;
1070 vd
->e
[i
].next_regno
!= regno
;
1071 i
= vd
->e
[i
].next_regno
)
1073 vd
->e
[i
].next_regno
= vd
->e
[regno
].next_regno
;
1075 else if ((next
= vd
->e
[regno
].next_regno
) != INVALID_REGNUM
)
1077 for (i
= next
; i
!= INVALID_REGNUM
; i
= vd
->e
[i
].next_regno
)
1078 vd
->e
[i
].oldest_regno
= next
;
1081 vd
->e
[regno
].mode
= VOIDmode
;
1082 vd
->e
[regno
].oldest_regno
= regno
;
1083 vd
->e
[regno
].next_regno
= INVALID_REGNUM
;
1085 #ifdef ENABLE_CHECKING
1086 validate_value_data (vd
);
1090 /* Kill X. This is a convenience function for kill_value_regno
1091 so that we mind the mode the register is in. */
1096 struct value_data
*vd
;
1098 /* SUBREGS are supposed to have been eliminated by now. But some
1099 ports, e.g. i386 sse, use them to smuggle vector type information
1100 through to instruction selection. Each such SUBREG should simplify,
1101 so if we get a NULL we've done something wrong elsewhere. */
1103 if (GET_CODE (x
) == SUBREG
)
1104 x
= simplify_subreg (GET_MODE (x
), SUBREG_REG (x
),
1105 GET_MODE (SUBREG_REG (x
)), SUBREG_BYTE (x
));
1108 unsigned int regno
= REGNO (x
);
1109 unsigned int n
= HARD_REGNO_NREGS (regno
, GET_MODE (x
));
1112 /* Kill the value we're told to kill. */
1113 for (i
= 0; i
< n
; ++i
)
1114 kill_value_regno (regno
+ i
, vd
);
1116 /* Kill everything that overlapped what we're told to kill. */
1117 if (regno
< vd
->max_value_regs
)
1120 j
= regno
- vd
->max_value_regs
;
1121 for (; j
< regno
; ++j
)
1123 if (vd
->e
[j
].mode
== VOIDmode
)
1125 n
= HARD_REGNO_NREGS (j
, vd
->e
[j
].mode
);
1127 for (i
= 0; i
< n
; ++i
)
1128 kill_value_regno (j
+ i
, vd
);
1133 /* Remember that REGNO is valid in MODE. */
1136 set_value_regno (regno
, mode
, vd
)
1138 enum machine_mode mode
;
1139 struct value_data
*vd
;
1143 vd
->e
[regno
].mode
= mode
;
1145 nregs
= HARD_REGNO_NREGS (regno
, mode
);
1146 if (nregs
> vd
->max_value_regs
)
1147 vd
->max_value_regs
= nregs
;
1150 /* Initialize VD such that there are no known relationships between regs. */
1153 init_value_data (vd
)
1154 struct value_data
*vd
;
1157 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
1159 vd
->e
[i
].mode
= VOIDmode
;
1160 vd
->e
[i
].oldest_regno
= i
;
1161 vd
->e
[i
].next_regno
= INVALID_REGNUM
;
1163 vd
->max_value_regs
= 0;
1166 /* Called through note_stores. If X is clobbered, kill its value. */
1169 kill_clobbered_value (x
, set
, data
)
1174 struct value_data
*vd
= data
;
1175 if (GET_CODE (set
) == CLOBBER
)
1179 /* Called through note_stores. If X is set, not clobbered, kill its
1180 current value and install it as the root of its own value list. */
1183 kill_set_value (x
, set
, data
)
1188 struct value_data
*vd
= data
;
1189 if (GET_CODE (set
) != CLOBBER
&& REG_P (x
))
1192 set_value_regno (REGNO (x
), GET_MODE (x
), vd
);
1196 /* Called through for_each_rtx. Kill any register used as the base of an
1197 auto-increment expression, and install that register as the root of its
1201 kill_autoinc_value (px
, data
)
1206 struct value_data
*vd
= data
;
1208 if (GET_RTX_CLASS (GET_CODE (x
)) == 'a')
1212 set_value_regno (REGNO (x
), Pmode
, vd
);
1219 /* Assert that SRC has been copied to DEST. Adjust the data structures
1220 to reflect that SRC contains an older copy of the shared value. */
1223 copy_value (dest
, src
, vd
)
1226 struct value_data
*vd
;
1228 unsigned int dr
= REGNO (dest
);
1229 unsigned int sr
= REGNO (src
);
1230 unsigned int dn
, sn
;
1233 /* ??? At present, it's possible to see noop sets. It'd be nice if
1234 this were cleaned up beforehand... */
1238 /* Do not propagate copies to the stack pointer, as that can leave
1239 memory accesses with no scheduling dependancy on the stack update. */
1240 if (dr
== STACK_POINTER_REGNUM
)
1243 /* Likewise with the frame pointer, if we're using one. */
1244 if (frame_pointer_needed
&& dr
== HARD_FRAME_POINTER_REGNUM
)
1247 /* If SRC and DEST overlap, don't record anything. */
1248 dn
= HARD_REGNO_NREGS (dr
, GET_MODE (dest
));
1249 sn
= HARD_REGNO_NREGS (sr
, GET_MODE (dest
));
1250 if ((dr
> sr
&& dr
< sr
+ sn
)
1251 || (sr
> dr
&& sr
< dr
+ dn
))
1254 /* If SRC had no assigned mode (i.e. we didn't know it was live)
1255 assign it now and assume the value came from an input argument
1257 if (vd
->e
[sr
].mode
== VOIDmode
)
1258 set_value_regno (sr
, vd
->e
[dr
].mode
, vd
);
1260 /* If SRC had been assigned a mode narrower than the copy, we can't
1261 link DEST into the chain, because not all of the pieces of the
1262 copy came from oldest_regno. */
1263 else if (sn
> (unsigned int) HARD_REGNO_NREGS (sr
, vd
->e
[sr
].mode
))
1266 /* Link DR at the end of the value chain used by SR. */
1268 vd
->e
[dr
].oldest_regno
= vd
->e
[sr
].oldest_regno
;
1270 for (i
= sr
; vd
->e
[i
].next_regno
!= INVALID_REGNUM
; i
= vd
->e
[i
].next_regno
)
1272 vd
->e
[i
].next_regno
= dr
;
1274 #ifdef ENABLE_CHECKING
1275 validate_value_data (vd
);
1279 /* Return true if a mode change from ORIG to NEW is allowed for REGNO. */
1282 mode_change_ok (orig_mode
, new_mode
, regno
)
1283 enum machine_mode orig_mode
, new_mode
;
1284 unsigned int regno ATTRIBUTE_UNUSED
;
1286 if (GET_MODE_SIZE (orig_mode
) < GET_MODE_SIZE (new_mode
))
1289 #ifdef CLASS_CANNOT_CHANGE_MODE
1290 if (TEST_HARD_REG_BIT (reg_class_contents
[CLASS_CANNOT_CHANGE_MODE
], regno
)
1291 && CLASS_CANNOT_CHANGE_MODE_P (orig_mode
, new_mode
))
1298 /* Find the oldest copy of the value contained in REGNO that is in
1299 register class CLASS and has mode MODE. If found, return an rtx
1300 of that oldest register, otherwise return NULL. */
1303 find_oldest_value_reg (class, reg
, vd
)
1304 enum reg_class
class;
1306 struct value_data
*vd
;
1308 unsigned int regno
= REGNO (reg
);
1309 enum machine_mode mode
= GET_MODE (reg
);
1312 /* If we are accessing REG in some mode other that what we set it in,
1313 make sure that the replacement is valid. In particular, consider
1314 (set (reg:DI r11) (...))
1315 (set (reg:SI r9) (reg:SI r11))
1316 (set (reg:SI r10) (...))
1317 (set (...) (reg:DI r9))
1318 Replacing r9 with r11 is invalid. */
1319 if (mode
!= vd
->e
[regno
].mode
)
1321 if (HARD_REGNO_NREGS (regno
, mode
)
1322 > HARD_REGNO_NREGS (regno
, vd
->e
[regno
].mode
))
1326 for (i
= vd
->e
[regno
].oldest_regno
; i
!= regno
; i
= vd
->e
[i
].next_regno
)
1327 if (TEST_HARD_REG_BIT (reg_class_contents
[class], i
)
1328 && (vd
->e
[i
].mode
== mode
1329 || mode_change_ok (vd
->e
[i
].mode
, mode
, i
)))
1331 rtx
new = gen_rtx_raw_REG (mode
, i
);
1332 ORIGINAL_REGNO (new) = ORIGINAL_REGNO (reg
);
1339 /* If possible, replace the register at *LOC with the oldest register
1340 in register class CLASS. Return true if successfully replaced. */
1343 replace_oldest_value_reg (loc
, class, insn
, vd
)
1345 enum reg_class
class;
1347 struct value_data
*vd
;
1349 rtx
new = find_oldest_value_reg (class, *loc
, vd
);
1353 fprintf (rtl_dump_file
, "insn %u: replaced reg %u with %u\n",
1354 INSN_UID (insn
), REGNO (*loc
), REGNO (new));
1362 /* Similar to replace_oldest_value_reg, but *LOC contains an address.
1363 Adapted from find_reloads_address_1. CLASS is INDEX_REG_CLASS or
1364 BASE_REG_CLASS depending on how the register is being considered. */
1367 replace_oldest_value_addr (loc
, class, mode
, insn
, vd
)
1369 enum reg_class
class;
1370 enum machine_mode mode
;
1372 struct value_data
*vd
;
1375 RTX_CODE code
= GET_CODE (x
);
1378 bool changed
= false;
1384 rtx orig_op0
= XEXP (x
, 0);
1385 rtx orig_op1
= XEXP (x
, 1);
1386 RTX_CODE code0
= GET_CODE (orig_op0
);
1387 RTX_CODE code1
= GET_CODE (orig_op1
);
1393 if (GET_CODE (op0
) == SUBREG
)
1395 op0
= SUBREG_REG (op0
);
1396 code0
= GET_CODE (op0
);
1399 if (GET_CODE (op1
) == SUBREG
)
1401 op1
= SUBREG_REG (op1
);
1402 code1
= GET_CODE (op1
);
1405 if (code0
== MULT
|| code0
== SIGN_EXTEND
|| code0
== TRUNCATE
1406 || code0
== ZERO_EXTEND
|| code1
== MEM
)
1408 locI
= &XEXP (x
, 0);
1409 locB
= &XEXP (x
, 1);
1411 else if (code1
== MULT
|| code1
== SIGN_EXTEND
|| code1
== TRUNCATE
1412 || code1
== ZERO_EXTEND
|| code0
== MEM
)
1414 locI
= &XEXP (x
, 1);
1415 locB
= &XEXP (x
, 0);
1417 else if (code0
== CONST_INT
|| code0
== CONST
1418 || code0
== SYMBOL_REF
|| code0
== LABEL_REF
)
1419 locB
= &XEXP (x
, 1);
1420 else if (code1
== CONST_INT
|| code1
== CONST
1421 || code1
== SYMBOL_REF
|| code1
== LABEL_REF
)
1422 locB
= &XEXP (x
, 0);
1423 else if (code0
== REG
&& code1
== REG
)
1427 if (REG_OK_FOR_INDEX_P (op0
)
1428 && REG_MODE_OK_FOR_BASE_P (op1
, mode
))
1430 else if (REG_OK_FOR_INDEX_P (op1
)
1431 && REG_MODE_OK_FOR_BASE_P (op0
, mode
))
1433 else if (REG_MODE_OK_FOR_BASE_P (op1
, mode
))
1435 else if (REG_MODE_OK_FOR_BASE_P (op0
, mode
))
1437 else if (REG_OK_FOR_INDEX_P (op1
))
1442 locI
= &XEXP (x
, index_op
);
1443 locB
= &XEXP (x
, !index_op
);
1445 else if (code0
== REG
)
1447 locI
= &XEXP (x
, 0);
1448 locB
= &XEXP (x
, 1);
1450 else if (code1
== REG
)
1452 locI
= &XEXP (x
, 1);
1453 locB
= &XEXP (x
, 0);
1457 changed
|= replace_oldest_value_addr (locI
, INDEX_REG_CLASS
, mode
,
1460 changed
|= replace_oldest_value_addr (locB
,
1461 MODE_BASE_REG_CLASS (mode
),
1475 return replace_oldest_value_mem (x
, insn
, vd
);
1478 return replace_oldest_value_reg (loc
, class, insn
, vd
);
1484 fmt
= GET_RTX_FORMAT (code
);
1485 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
1488 changed
|= replace_oldest_value_addr (&XEXP (x
, i
), class, mode
,
1490 else if (fmt
[i
] == 'E')
1491 for (j
= XVECLEN (x
, i
) - 1; j
>= 0; j
--)
1492 changed
|= replace_oldest_value_addr (&XVECEXP (x
, i
, j
), class,
1499 /* Similar to replace_oldest_value_reg, but X contains a memory. */
1502 replace_oldest_value_mem (x
, insn
, vd
)
1505 struct value_data
*vd
;
1507 return replace_oldest_value_addr (&XEXP (x
, 0),
1508 MODE_BASE_REG_CLASS (GET_MODE (x
)),
1509 GET_MODE (x
), insn
, vd
);
1512 /* Perform the forward copy propagation on basic block BB. */
1515 copyprop_hardreg_forward_1 (bb
, vd
)
1517 struct value_data
*vd
;
1519 bool changed
= false;
1522 for (insn
= bb
->head
; ; insn
= NEXT_INSN (insn
))
1524 int n_ops
, i
, alt
, predicated
;
1528 if (! INSN_P (insn
))
1530 if (insn
== bb
->end
)
1536 set
= single_set (insn
);
1537 extract_insn (insn
);
1538 constrain_operands (1);
1539 preprocess_constraints ();
1540 alt
= which_alternative
;
1541 n_ops
= recog_data
.n_operands
;
1542 is_asm
= asm_noperands (PATTERN (insn
)) >= 0;
1544 /* Simplify the code below by rewriting things to reflect
1545 matching constraints. Also promote OP_OUT to OP_INOUT
1546 in predicated instructions. */
1548 predicated
= GET_CODE (PATTERN (insn
)) == COND_EXEC
;
1549 for (i
= 0; i
< n_ops
; ++i
)
1551 int matches
= recog_op_alt
[i
][alt
].matches
;
1553 recog_op_alt
[i
][alt
].class = recog_op_alt
[matches
][alt
].class;
1554 if (matches
>= 0 || recog_op_alt
[i
][alt
].matched
>= 0
1555 || (predicated
&& recog_data
.operand_type
[i
] == OP_OUT
))
1556 recog_data
.operand_type
[i
] = OP_INOUT
;
1559 /* For each earlyclobber operand, zap the value data. */
1560 for (i
= 0; i
< n_ops
; i
++)
1561 if (recog_op_alt
[i
][alt
].earlyclobber
)
1562 kill_value (recog_data
.operand
[i
], vd
);
1564 /* Within asms, a clobber cannot overlap inputs or outputs.
1565 I wouldn't think this were true for regular insns, but
1566 scan_rtx treats them like that... */
1567 note_stores (PATTERN (insn
), kill_clobbered_value
, vd
);
1569 /* Kill all auto-incremented values. */
1570 /* ??? REG_INC is useless, since stack pushes aren't done that way. */
1571 for_each_rtx (&PATTERN (insn
), kill_autoinc_value
, vd
);
1573 /* Kill all early-clobbered operands. */
1574 for (i
= 0; i
< n_ops
; i
++)
1575 if (recog_op_alt
[i
][alt
].earlyclobber
)
1576 kill_value (recog_data
.operand
[i
], vd
);
1578 /* Special-case plain move instructions, since we may well
1579 be able to do the move from a different register class. */
1580 if (set
&& REG_P (SET_SRC (set
)))
1582 rtx src
= SET_SRC (set
);
1583 unsigned int regno
= REGNO (src
);
1584 enum machine_mode mode
= GET_MODE (src
);
1588 /* If we are accessing SRC in some mode other that what we
1589 set it in, make sure that the replacement is valid. */
1590 if (mode
!= vd
->e
[regno
].mode
)
1592 if (HARD_REGNO_NREGS (regno
, mode
)
1593 > HARD_REGNO_NREGS (regno
, vd
->e
[regno
].mode
))
1594 goto no_move_special_case
;
1597 /* If the destination is also a register, try to find a source
1598 register in the same class. */
1599 if (REG_P (SET_DEST (set
)))
1601 new = find_oldest_value_reg (REGNO_REG_CLASS (regno
), src
, vd
);
1602 if (new && validate_change (insn
, &SET_SRC (set
), new, 0))
1605 fprintf (rtl_dump_file
,
1606 "insn %u: replaced reg %u with %u\n",
1607 INSN_UID (insn
), regno
, REGNO (new));
1609 goto did_replacement
;
1613 /* Otherwise, try all valid registers and see if its valid. */
1614 for (i
= vd
->e
[regno
].oldest_regno
; i
!= regno
;
1615 i
= vd
->e
[i
].next_regno
)
1616 if (vd
->e
[i
].mode
== mode
1617 || mode_change_ok (vd
->e
[i
].mode
, mode
, i
))
1619 new = gen_rtx_raw_REG (mode
, i
);
1620 if (validate_change (insn
, &SET_SRC (set
), new, 0))
1622 ORIGINAL_REGNO (new) = ORIGINAL_REGNO (src
);
1624 fprintf (rtl_dump_file
,
1625 "insn %u: replaced reg %u with %u\n",
1626 INSN_UID (insn
), regno
, REGNO (new));
1628 goto did_replacement
;
1632 no_move_special_case
:
1634 /* For each input operand, replace a hard register with the
1635 eldest live copy that's in an appropriate register class. */
1636 for (i
= 0; i
< n_ops
; i
++)
1638 bool replaced
= false;
1640 /* Don't scan match_operand here, since we've no reg class
1641 information to pass down. Any operands that we could
1642 substitute in will be represented elsewhere. */
1643 if (recog_data
.constraints
[i
][0] == '\0')
1646 /* Don't replace in asms intentionally referencing hard regs. */
1647 if (is_asm
&& GET_CODE (recog_data
.operand
[i
]) == REG
1648 && (REGNO (recog_data
.operand
[i
])
1649 == ORIGINAL_REGNO (recog_data
.operand
[i
])))
1652 if (recog_data
.operand_type
[i
] == OP_IN
)
1654 if (recog_op_alt
[i
][alt
].is_address
)
1656 = replace_oldest_value_addr (recog_data
.operand_loc
[i
],
1657 recog_op_alt
[i
][alt
].class,
1658 VOIDmode
, insn
, vd
);
1659 else if (REG_P (recog_data
.operand
[i
]))
1661 = replace_oldest_value_reg (recog_data
.operand_loc
[i
],
1662 recog_op_alt
[i
][alt
].class,
1664 else if (GET_CODE (recog_data
.operand
[i
]) == MEM
)
1665 replaced
= replace_oldest_value_mem (recog_data
.operand
[i
],
1668 else if (GET_CODE (recog_data
.operand
[i
]) == MEM
)
1669 replaced
= replace_oldest_value_mem (recog_data
.operand
[i
],
1672 /* If we performed any replacement, update match_dups. */
1680 new = *recog_data
.operand_loc
[i
];
1681 recog_data
.operand
[i
] = new;
1682 for (j
= 0; j
< recog_data
.n_dups
; j
++)
1683 if (recog_data
.dup_num
[j
] == i
)
1684 *recog_data
.dup_loc
[j
] = new;
1689 /* Clobber call-clobbered registers. */
1690 if (GET_CODE (insn
) == CALL_INSN
)
1691 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; i
++)
1692 if (TEST_HARD_REG_BIT (regs_invalidated_by_call
, i
))
1693 kill_value_regno (i
, vd
);
1695 /* Notice stores. */
1696 note_stores (PATTERN (insn
), kill_set_value
, vd
);
1698 /* Notice copies. */
1699 if (set
&& REG_P (SET_DEST (set
)) && REG_P (SET_SRC (set
)))
1700 copy_value (SET_DEST (set
), SET_SRC (set
), vd
);
1702 if (insn
== bb
->end
)
1709 /* Main entry point for the forward copy propagation optimization. */
1712 copyprop_hardreg_forward ()
1714 struct value_data
*all_vd
;
1718 need_refresh
= false;
1720 all_vd
= xmalloc (sizeof (struct value_data
) * n_basic_blocks
);
1722 for (b
= 0; b
< n_basic_blocks
; b
++)
1724 basic_block bb
= BASIC_BLOCK (b
);
1726 /* If a block has a single predecessor, that we've already
1727 processed, begin with the value data that was live at
1728 the end of the predecessor block. */
1729 /* ??? Ought to use more intelligent queueing of blocks. */
1731 && ! bb
->pred
->pred_next
1732 && ! (bb
->pred
->flags
& (EDGE_ABNORMAL_CALL
| EDGE_EH
))
1733 && bb
->pred
->src
->index
!= ENTRY_BLOCK
1734 && bb
->pred
->src
->index
< b
)
1735 all_vd
[b
] = all_vd
[bb
->pred
->src
->index
];
1737 init_value_data (all_vd
+ b
);
1739 if (copyprop_hardreg_forward_1 (bb
, all_vd
+ b
))
1740 need_refresh
= true;
1746 fputs ("\n\n", rtl_dump_file
);
1748 /* ??? Irritatingly, delete_noop_moves does not take a set of blocks
1749 to scan, so we have to do a life update with no initial set of
1750 blocks Just In Case. */
1751 delete_noop_moves (get_insns ());
1752 update_life_info (NULL
, UPDATE_LIFE_GLOBAL_RM_NOTES
,
1754 | PROP_SCAN_DEAD_CODE
1755 | PROP_KILL_DEAD_CODE
);
1761 /* Dump the value chain data to stderr. */
1764 debug_value_data (vd
)
1765 struct value_data
*vd
;
1770 CLEAR_HARD_REG_SET (set
);
1772 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
1773 if (vd
->e
[i
].oldest_regno
== i
)
1775 if (vd
->e
[i
].mode
== VOIDmode
)
1777 if (vd
->e
[i
].next_regno
!= INVALID_REGNUM
)
1778 fprintf (stderr
, "[%u] Bad next_regno for empty chain (%u)\n",
1779 i
, vd
->e
[i
].next_regno
);
1783 SET_HARD_REG_BIT (set
, i
);
1784 fprintf (stderr
, "[%u %s] ", i
, GET_MODE_NAME (vd
->e
[i
].mode
));
1786 for (j
= vd
->e
[i
].next_regno
;
1787 j
!= INVALID_REGNUM
;
1788 j
= vd
->e
[j
].next_regno
)
1790 if (TEST_HARD_REG_BIT (set
, j
))
1792 fprintf (stderr
, "[%u] Loop in regno chain\n", j
);
1796 if (vd
->e
[j
].oldest_regno
!= i
)
1798 fprintf (stderr
, "[%u] Bad oldest_regno (%u)\n",
1799 j
, vd
->e
[j
].oldest_regno
);
1802 SET_HARD_REG_BIT (set
, j
);
1803 fprintf (stderr
, "[%u %s] ", j
, GET_MODE_NAME (vd
->e
[j
].mode
));
1805 fputc ('\n', stderr
);
1808 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
1809 if (! TEST_HARD_REG_BIT (set
, i
)
1810 && (vd
->e
[i
].mode
!= VOIDmode
1811 || vd
->e
[i
].oldest_regno
!= i
1812 || vd
->e
[i
].next_regno
!= INVALID_REGNUM
))
1813 fprintf (stderr
, "[%u] Non-empty reg in chain (%s %u %i)\n",
1814 i
, GET_MODE_NAME (vd
->e
[i
].mode
), vd
->e
[i
].oldest_regno
,
1815 vd
->e
[i
].next_regno
);
1818 #ifdef ENABLE_CHECKING
1820 validate_value_data (vd
)
1821 struct value_data
*vd
;
1826 CLEAR_HARD_REG_SET (set
);
1828 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
1829 if (vd
->e
[i
].oldest_regno
== i
)
1831 if (vd
->e
[i
].mode
== VOIDmode
)
1833 if (vd
->e
[i
].next_regno
!= INVALID_REGNUM
)
1834 internal_error ("validate_value_data: [%u] Bad next_regno for empty chain (%u)",
1835 i
, vd
->e
[i
].next_regno
);
1839 SET_HARD_REG_BIT (set
, i
);
1841 for (j
= vd
->e
[i
].next_regno
;
1842 j
!= INVALID_REGNUM
;
1843 j
= vd
->e
[j
].next_regno
)
1845 if (TEST_HARD_REG_BIT (set
, j
))
1846 internal_error ("validate_value_data: Loop in regno chain (%u)",
1848 if (vd
->e
[j
].oldest_regno
!= i
)
1849 internal_error ("validate_value_data: [%u] Bad oldest_regno (%u)",
1850 j
, vd
->e
[j
].oldest_regno
);
1852 SET_HARD_REG_BIT (set
, j
);
1856 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
1857 if (! TEST_HARD_REG_BIT (set
, i
)
1858 && (vd
->e
[i
].mode
!= VOIDmode
1859 || vd
->e
[i
].oldest_regno
!= i
1860 || vd
->e
[i
].next_regno
!= INVALID_REGNUM
))
1861 internal_error ("validate_value_data: [%u] Non-empty reg in chain (%s %u %i)",
1862 i
, GET_MODE_NAME (vd
->e
[i
].mode
), vd
->e
[i
].oldest_regno
,
1863 vd
->e
[i
].next_regno
);