1 /* Register renaming for the GNU compiler.
2 Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005
3 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it
8 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 GCC is distributed in the hope that it will be useful, but WITHOUT
13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
15 License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
24 #include "coretypes.h"
28 #include "insn-config.h"
30 #include "hard-reg-set.h"
31 #include "basic-block.h"
42 struct du_chain
*next_chain
;
43 struct du_chain
*next_use
;
47 ENUM_BITFIELD(reg_class
) cl
: 16;
48 unsigned int need_caller_save_reg
:1;
49 unsigned int earlyclobber
:1;
55 terminate_overlapping_read
,
62 static const char * const scan_actions_name
[] =
65 "terminate_overlapping_read",
72 static struct obstack rename_obstack
;
74 static void do_replace (struct du_chain
*, int);
75 static void scan_rtx_reg (rtx
, rtx
*, enum reg_class
,
76 enum scan_actions
, enum op_type
, int);
77 static void scan_rtx_address (rtx
, rtx
*, enum reg_class
,
78 enum scan_actions
, enum machine_mode
);
79 static void scan_rtx (rtx
, rtx
*, enum reg_class
, enum scan_actions
,
81 static struct du_chain
*build_def_use (basic_block
);
82 static void dump_def_use_chain (struct du_chain
*);
83 static void note_sets (rtx
, rtx
, void *);
84 static void clear_dead_regs (HARD_REG_SET
*, enum machine_mode
, rtx
);
85 static void merge_overlapping_regs (basic_block
, HARD_REG_SET
*,
88 /* Called through note_stores from update_life. Find sets of registers, and
89 record them in *DATA (which is actually a HARD_REG_SET *). */
92 note_sets (rtx x
, rtx set ATTRIBUTE_UNUSED
, void *data
)
94 HARD_REG_SET
*pset
= (HARD_REG_SET
*) data
;
100 nregs
= hard_regno_nregs
[regno
][GET_MODE (x
)];
102 /* There must not be pseudos at this point. */
103 gcc_assert (regno
+ nregs
<= FIRST_PSEUDO_REGISTER
);
106 SET_HARD_REG_BIT (*pset
, regno
+ nregs
);
109 /* Clear all registers from *PSET for which a note of kind KIND can be found
110 in the list NOTES. */
113 clear_dead_regs (HARD_REG_SET
*pset
, enum machine_mode kind
, rtx notes
)
116 for (note
= notes
; note
; note
= XEXP (note
, 1))
117 if (REG_NOTE_KIND (note
) == kind
&& REG_P (XEXP (note
, 0)))
119 rtx reg
= XEXP (note
, 0);
120 unsigned int regno
= REGNO (reg
);
121 int nregs
= hard_regno_nregs
[regno
][GET_MODE (reg
)];
123 /* There must not be pseudos at this point. */
124 gcc_assert (regno
+ nregs
<= FIRST_PSEUDO_REGISTER
);
127 CLEAR_HARD_REG_BIT (*pset
, regno
+ nregs
);
131 /* For a def-use chain CHAIN in basic block B, find which registers overlap
132 its lifetime and set the corresponding bits in *PSET. */
135 merge_overlapping_regs (basic_block b
, HARD_REG_SET
*pset
,
136 struct du_chain
*chain
)
138 struct du_chain
*t
= chain
;
142 REG_SET_TO_HARD_REG_SET (live
, b
->global_live_at_start
);
146 /* Search forward until the next reference to the register to be
148 while (insn
!= t
->insn
)
152 clear_dead_regs (&live
, REG_DEAD
, REG_NOTES (insn
));
153 note_stores (PATTERN (insn
), note_sets
, (void *) &live
);
154 /* Only record currently live regs if we are inside the
157 IOR_HARD_REG_SET (*pset
, live
);
158 clear_dead_regs (&live
, REG_UNUSED
, REG_NOTES (insn
));
160 insn
= NEXT_INSN (insn
);
163 IOR_HARD_REG_SET (*pset
, live
);
165 /* For the last reference, also merge in all registers set in the
167 @@@ We only have take earlyclobbered sets into account. */
169 note_stores (PATTERN (insn
), note_sets
, (void *) pset
);
175 /* Perform register renaming on the current function. */
178 regrename_optimize (void)
180 int tick
[FIRST_PSEUDO_REGISTER
];
185 memset (tick
, 0, sizeof tick
);
187 gcc_obstack_init (&rename_obstack
);
188 first_obj
= obstack_alloc (&rename_obstack
, 0);
192 struct du_chain
*all_chains
= 0;
193 HARD_REG_SET unavailable
;
194 HARD_REG_SET regs_seen
;
196 CLEAR_HARD_REG_SET (unavailable
);
199 fprintf (dump_file
, "\nBasic block %d:\n", bb
->index
);
201 all_chains
= build_def_use (bb
);
204 dump_def_use_chain (all_chains
);
206 CLEAR_HARD_REG_SET (unavailable
);
207 /* Don't clobber traceback for noreturn functions. */
208 if (frame_pointer_needed
)
212 for (i
= hard_regno_nregs
[FRAME_POINTER_REGNUM
][Pmode
]; i
--;)
213 SET_HARD_REG_BIT (unavailable
, FRAME_POINTER_REGNUM
+ i
);
215 #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
216 for (i
= hard_regno_nregs
[HARD_FRAME_POINTER_REGNUM
][Pmode
]; i
--;)
217 SET_HARD_REG_BIT (unavailable
, HARD_FRAME_POINTER_REGNUM
+ i
);
221 CLEAR_HARD_REG_SET (regs_seen
);
224 int new_reg
, best_new_reg
;
226 struct du_chain
*this = all_chains
;
227 struct du_chain
*tmp
, *last
;
228 HARD_REG_SET this_unavailable
;
229 int reg
= REGNO (*this->loc
);
232 all_chains
= this->next_chain
;
236 #if 0 /* This just disables optimization opportunities. */
237 /* Only rename once we've seen the reg more than once. */
238 if (! TEST_HARD_REG_BIT (regs_seen
, reg
))
240 SET_HARD_REG_BIT (regs_seen
, reg
);
245 if (fixed_regs
[reg
] || global_regs
[reg
]
246 #if FRAME_POINTER_REGNUM != HARD_FRAME_POINTER_REGNUM
247 || (frame_pointer_needed
&& reg
== HARD_FRAME_POINTER_REGNUM
)
249 || (frame_pointer_needed
&& reg
== FRAME_POINTER_REGNUM
)
254 COPY_HARD_REG_SET (this_unavailable
, unavailable
);
256 /* Find last entry on chain (which has the need_caller_save bit),
257 count number of uses, and narrow the set of registers we can
260 for (last
= this; last
->next_use
; last
= last
->next_use
)
263 IOR_COMPL_HARD_REG_SET (this_unavailable
,
264 reg_class_contents
[last
->cl
]);
269 IOR_COMPL_HARD_REG_SET (this_unavailable
,
270 reg_class_contents
[last
->cl
]);
272 if (this->need_caller_save_reg
)
273 IOR_HARD_REG_SET (this_unavailable
, call_used_reg_set
);
275 merge_overlapping_regs (bb
, &this_unavailable
, this);
277 /* Now potential_regs is a reasonable approximation, let's
278 have a closer look at each register still in there. */
279 for (new_reg
= 0; new_reg
< FIRST_PSEUDO_REGISTER
; new_reg
++)
281 int nregs
= hard_regno_nregs
[new_reg
][GET_MODE (*this->loc
)];
283 for (i
= nregs
- 1; i
>= 0; --i
)
284 if (TEST_HARD_REG_BIT (this_unavailable
, new_reg
+ i
)
285 || fixed_regs
[new_reg
+ i
]
286 || global_regs
[new_reg
+ i
]
287 /* Can't use regs which aren't saved by the prologue. */
288 || (! regs_ever_live
[new_reg
+ i
]
289 && ! call_used_regs
[new_reg
+ i
])
290 #ifdef LEAF_REGISTERS
291 /* We can't use a non-leaf register if we're in a
293 || (current_function_is_leaf
294 && !LEAF_REGISTERS
[new_reg
+ i
])
296 #ifdef HARD_REGNO_RENAME_OK
297 || ! HARD_REGNO_RENAME_OK (reg
+ i
, new_reg
+ i
)
304 /* See whether it accepts all modes that occur in
305 definition and uses. */
306 for (tmp
= this; tmp
; tmp
= tmp
->next_use
)
307 if (! HARD_REGNO_MODE_OK (new_reg
, GET_MODE (*tmp
->loc
))
308 || (tmp
->need_caller_save_reg
309 && ! (HARD_REGNO_CALL_PART_CLOBBERED
310 (reg
, GET_MODE (*tmp
->loc
)))
311 && (HARD_REGNO_CALL_PART_CLOBBERED
312 (new_reg
, GET_MODE (*tmp
->loc
)))))
316 if (tick
[best_new_reg
] > tick
[new_reg
])
317 best_new_reg
= new_reg
;
323 fprintf (dump_file
, "Register %s in insn %d",
324 reg_names
[reg
], INSN_UID (last
->insn
));
325 if (last
->need_caller_save_reg
)
326 fprintf (dump_file
, " crosses a call");
329 if (best_new_reg
== reg
)
331 tick
[reg
] = ++this_tick
;
333 fprintf (dump_file
, "; no available better choice\n");
337 do_replace (this, best_new_reg
);
338 tick
[best_new_reg
] = ++this_tick
;
339 regs_ever_live
[best_new_reg
] = 1;
342 fprintf (dump_file
, ", renamed as %s\n", reg_names
[best_new_reg
]);
345 obstack_free (&rename_obstack
, first_obj
);
348 obstack_free (&rename_obstack
, NULL
);
351 fputc ('\n', dump_file
);
353 count_or_remove_death_notes (NULL
, 1);
354 update_life_info (NULL
, UPDATE_LIFE_LOCAL
,
359 do_replace (struct du_chain
*chain
, int reg
)
363 unsigned int regno
= ORIGINAL_REGNO (*chain
->loc
);
364 struct reg_attrs
* attr
= REG_ATTRS (*chain
->loc
);
366 *chain
->loc
= gen_raw_REG (GET_MODE (*chain
->loc
), reg
);
367 if (regno
>= FIRST_PSEUDO_REGISTER
)
368 ORIGINAL_REGNO (*chain
->loc
) = regno
;
369 REG_ATTRS (*chain
->loc
) = attr
;
370 chain
= chain
->next_use
;
375 static struct du_chain
*open_chains
;
376 static struct du_chain
*closed_chains
;
379 scan_rtx_reg (rtx insn
, rtx
*loc
, enum reg_class cl
,
380 enum scan_actions action
, enum op_type type
, int earlyclobber
)
384 enum machine_mode mode
= GET_MODE (x
);
385 int this_regno
= REGNO (x
);
386 int this_nregs
= hard_regno_nregs
[this_regno
][mode
];
388 if (action
== mark_write
)
392 struct du_chain
*this
393 = obstack_alloc (&rename_obstack
, sizeof (struct du_chain
));
395 this->next_chain
= open_chains
;
399 this->need_caller_save_reg
= 0;
400 this->earlyclobber
= earlyclobber
;
406 if ((type
== OP_OUT
&& action
!= terminate_write
)
407 || (type
!= OP_OUT
&& action
== terminate_write
))
410 for (p
= &open_chains
; *p
;)
412 struct du_chain
*this = *p
;
414 /* Check if the chain has been terminated if it has then skip to
417 This can happen when we've already appended the location to
418 the chain in Step 3, but are trying to hide in-out operands
419 from terminate_write in Step 5. */
421 if (*this->loc
== cc0_rtx
)
422 p
= &this->next_chain
;
425 int regno
= REGNO (*this->loc
);
426 int nregs
= hard_regno_nregs
[regno
][GET_MODE (*this->loc
)];
427 int exact_match
= (regno
== this_regno
&& nregs
== this_nregs
);
429 if (regno
+ nregs
<= this_regno
430 || this_regno
+ this_nregs
<= regno
)
432 p
= &this->next_chain
;
436 if (action
== mark_read
)
438 gcc_assert (exact_match
);
440 /* ??? Class NO_REGS can happen if the md file makes use of
441 EXTRA_CONSTRAINTS to match registers. Which is arguably
442 wrong, but there we are. Since we know not what this may
443 be replaced with, terminate the chain. */
446 this = obstack_alloc (&rename_obstack
, sizeof (struct du_chain
));
448 this->next_chain
= (*p
)->next_chain
;
452 this->need_caller_save_reg
= 0;
460 if (action
!= terminate_overlapping_read
|| ! exact_match
)
462 struct du_chain
*next
= this->next_chain
;
464 /* Whether the terminated chain can be used for renaming
465 depends on the action and this being an exact match.
466 In either case, we remove this element from open_chains. */
468 if ((action
== terminate_dead
|| action
== terminate_write
)
471 this->next_chain
= closed_chains
;
472 closed_chains
= this;
475 "Closing chain %s at insn %d (%s)\n",
476 reg_names
[REGNO (*this->loc
)], INSN_UID (insn
),
477 scan_actions_name
[(int) action
]);
483 "Discarding chain %s at insn %d (%s)\n",
484 reg_names
[REGNO (*this->loc
)], INSN_UID (insn
),
485 scan_actions_name
[(int) action
]);
490 p
= &this->next_chain
;
495 /* Adapted from find_reloads_address_1. CL is INDEX_REG_CLASS or
496 BASE_REG_CLASS depending on how the register is being considered. */
499 scan_rtx_address (rtx insn
, rtx
*loc
, enum reg_class cl
,
500 enum scan_actions action
, enum machine_mode mode
)
503 RTX_CODE code
= GET_CODE (x
);
507 if (action
== mark_write
)
514 rtx orig_op0
= XEXP (x
, 0);
515 rtx orig_op1
= XEXP (x
, 1);
516 RTX_CODE code0
= GET_CODE (orig_op0
);
517 RTX_CODE code1
= GET_CODE (orig_op1
);
522 rtx
*locB_reg
= NULL
;
524 if (GET_CODE (op0
) == SUBREG
)
526 op0
= SUBREG_REG (op0
);
527 code0
= GET_CODE (op0
);
530 if (GET_CODE (op1
) == SUBREG
)
532 op1
= SUBREG_REG (op1
);
533 code1
= GET_CODE (op1
);
536 if (code0
== MULT
|| code0
== SIGN_EXTEND
|| code0
== TRUNCATE
537 || code0
== ZERO_EXTEND
|| code1
== MEM
)
542 else if (code1
== MULT
|| code1
== SIGN_EXTEND
|| code1
== TRUNCATE
543 || code1
== ZERO_EXTEND
|| code0
== MEM
)
548 else if (code0
== CONST_INT
|| code0
== CONST
549 || code0
== SYMBOL_REF
|| code0
== LABEL_REF
)
551 else if (code1
== CONST_INT
|| code1
== CONST
552 || code1
== SYMBOL_REF
|| code1
== LABEL_REF
)
554 else if (code0
== REG
&& code1
== REG
)
558 if (REG_OK_FOR_INDEX_P (op0
)
559 && REG_MODE_OK_FOR_REG_BASE_P (op1
, mode
))
561 else if (REG_OK_FOR_INDEX_P (op1
)
562 && REG_MODE_OK_FOR_REG_BASE_P (op0
, mode
))
564 else if (REG_MODE_OK_FOR_REG_BASE_P (op1
, mode
))
566 else if (REG_MODE_OK_FOR_REG_BASE_P (op0
, mode
))
568 else if (REG_OK_FOR_INDEX_P (op1
))
573 locI
= &XEXP (x
, index_op
);
574 locB_reg
= &XEXP (x
, !index_op
);
576 else if (code0
== REG
)
581 else if (code1
== REG
)
588 scan_rtx_address (insn
, locI
, INDEX_REG_CLASS
, action
, mode
);
590 scan_rtx_address (insn
, locB
, MODE_BASE_REG_CLASS (mode
), action
, mode
);
592 scan_rtx_address (insn
, locB_reg
, MODE_BASE_REG_REG_CLASS (mode
),
604 /* If the target doesn't claim to handle autoinc, this must be
605 something special, like a stack push. Kill this chain. */
606 action
= terminate_all_read
;
611 scan_rtx_address (insn
, &XEXP (x
, 0),
612 MODE_BASE_REG_CLASS (GET_MODE (x
)), action
,
617 scan_rtx_reg (insn
, loc
, cl
, action
, OP_IN
, 0);
624 fmt
= GET_RTX_FORMAT (code
);
625 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
628 scan_rtx_address (insn
, &XEXP (x
, i
), cl
, action
, mode
);
629 else if (fmt
[i
] == 'E')
630 for (j
= XVECLEN (x
, i
) - 1; j
>= 0; j
--)
631 scan_rtx_address (insn
, &XVECEXP (x
, i
, j
), cl
, action
, mode
);
636 scan_rtx (rtx insn
, rtx
*loc
, enum reg_class cl
,
637 enum scan_actions action
, enum op_type type
, int earlyclobber
)
641 enum rtx_code code
= GET_CODE (x
);
658 scan_rtx_reg (insn
, loc
, cl
, action
, type
, earlyclobber
);
662 scan_rtx_address (insn
, &XEXP (x
, 0),
663 MODE_BASE_REG_CLASS (GET_MODE (x
)), action
,
668 scan_rtx (insn
, &SET_SRC (x
), cl
, action
, OP_IN
, 0);
669 scan_rtx (insn
, &SET_DEST (x
), cl
, action
,
670 GET_CODE (PATTERN (insn
)) == COND_EXEC
? OP_INOUT
: OP_OUT
, 0);
673 case STRICT_LOW_PART
:
674 scan_rtx (insn
, &XEXP (x
, 0), cl
, action
, OP_INOUT
, earlyclobber
);
679 scan_rtx (insn
, &XEXP (x
, 0), cl
, action
,
680 type
== OP_IN
? OP_IN
: OP_INOUT
, earlyclobber
);
681 scan_rtx (insn
, &XEXP (x
, 1), cl
, action
, OP_IN
, 0);
682 scan_rtx (insn
, &XEXP (x
, 2), cl
, action
, OP_IN
, 0);
691 /* Should only happen inside MEM. */
695 scan_rtx (insn
, &SET_DEST (x
), cl
, action
,
696 GET_CODE (PATTERN (insn
)) == COND_EXEC
? OP_INOUT
: OP_OUT
, 0);
700 scan_rtx (insn
, &XEXP (x
, 0), cl
, action
, type
, 0);
702 scan_rtx (insn
, &XEXP (x
, 1), cl
, action
, type
, 0);
709 fmt
= GET_RTX_FORMAT (code
);
710 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
713 scan_rtx (insn
, &XEXP (x
, i
), cl
, action
, type
, 0);
714 else if (fmt
[i
] == 'E')
715 for (j
= XVECLEN (x
, i
) - 1; j
>= 0; j
--)
716 scan_rtx (insn
, &XVECEXP (x
, i
, j
), cl
, action
, type
, 0);
720 /* Build def/use chain. */
722 static struct du_chain
*
723 build_def_use (basic_block bb
)
727 open_chains
= closed_chains
= NULL
;
729 for (insn
= BB_HEAD (bb
); ; insn
= NEXT_INSN (insn
))
735 rtx old_operands
[MAX_RECOG_OPERANDS
];
736 rtx old_dups
[MAX_DUP_OPERANDS
];
741 /* Process the insn, determining its effect on the def-use
742 chains. We perform the following steps with the register
743 references in the insn:
744 (1) Any read that overlaps an open chain, but doesn't exactly
745 match, causes that chain to be closed. We can't deal
747 (2) Any read outside an operand causes any chain it overlaps
748 with to be closed, since we can't replace it.
749 (3) Any read inside an operand is added if there's already
750 an open chain for it.
751 (4) For any REG_DEAD note we find, close open chains that
753 (5) For any write we find, close open chains that overlap it.
754 (6) For any write we find in an operand, make a new chain.
755 (7) For any REG_UNUSED, close any chains we just opened. */
757 icode
= recog_memoized (insn
);
759 if (! constrain_operands (1))
760 fatal_insn_not_found (insn
);
761 preprocess_constraints ();
762 alt
= which_alternative
;
763 n_ops
= recog_data
.n_operands
;
765 /* Simplify the code below by rewriting things to reflect
766 matching constraints. Also promote OP_OUT to OP_INOUT
767 in predicated instructions. */
769 predicated
= GET_CODE (PATTERN (insn
)) == COND_EXEC
;
770 for (i
= 0; i
< n_ops
; ++i
)
772 int matches
= recog_op_alt
[i
][alt
].matches
;
774 recog_op_alt
[i
][alt
].cl
= recog_op_alt
[matches
][alt
].cl
;
775 if (matches
>= 0 || recog_op_alt
[i
][alt
].matched
>= 0
776 || (predicated
&& recog_data
.operand_type
[i
] == OP_OUT
))
777 recog_data
.operand_type
[i
] = OP_INOUT
;
780 /* Step 1: Close chains for which we have overlapping reads. */
781 for (i
= 0; i
< n_ops
; i
++)
782 scan_rtx (insn
, recog_data
.operand_loc
[i
],
783 NO_REGS
, terminate_overlapping_read
,
784 recog_data
.operand_type
[i
], 0);
786 /* Step 2: Close chains for which we have reads outside operands.
787 We do this by munging all operands into CC0, and closing
788 everything remaining. */
790 for (i
= 0; i
< n_ops
; i
++)
792 old_operands
[i
] = recog_data
.operand
[i
];
793 /* Don't squash match_operator or match_parallel here, since
794 we don't know that all of the contained registers are
795 reachable by proper operands. */
796 if (recog_data
.constraints
[i
][0] == '\0')
798 *recog_data
.operand_loc
[i
] = cc0_rtx
;
800 for (i
= 0; i
< recog_data
.n_dups
; i
++)
802 int dup_num
= recog_data
.dup_num
[i
];
804 old_dups
[i
] = *recog_data
.dup_loc
[i
];
805 *recog_data
.dup_loc
[i
] = cc0_rtx
;
807 /* For match_dup of match_operator or match_parallel, share
808 them, so that we don't miss changes in the dup. */
810 && insn_data
[icode
].operand
[dup_num
].eliminable
== 0)
811 old_dups
[i
] = recog_data
.operand
[dup_num
];
814 scan_rtx (insn
, &PATTERN (insn
), NO_REGS
, terminate_all_read
,
817 for (i
= 0; i
< recog_data
.n_dups
; i
++)
818 *recog_data
.dup_loc
[i
] = old_dups
[i
];
819 for (i
= 0; i
< n_ops
; i
++)
820 *recog_data
.operand_loc
[i
] = old_operands
[i
];
822 /* Step 2B: Can't rename function call argument registers. */
823 if (CALL_P (insn
) && CALL_INSN_FUNCTION_USAGE (insn
))
824 scan_rtx (insn
, &CALL_INSN_FUNCTION_USAGE (insn
),
825 NO_REGS
, terminate_all_read
, OP_IN
, 0);
827 /* Step 2C: Can't rename asm operands that were originally
829 if (asm_noperands (PATTERN (insn
)) > 0)
830 for (i
= 0; i
< n_ops
; i
++)
832 rtx
*loc
= recog_data
.operand_loc
[i
];
836 && REGNO (op
) == ORIGINAL_REGNO (op
)
837 && (recog_data
.operand_type
[i
] == OP_IN
838 || recog_data
.operand_type
[i
] == OP_INOUT
))
839 scan_rtx (insn
, loc
, NO_REGS
, terminate_all_read
, OP_IN
, 0);
842 /* Step 3: Append to chains for reads inside operands. */
843 for (i
= 0; i
< n_ops
+ recog_data
.n_dups
; i
++)
845 int opn
= i
< n_ops
? i
: recog_data
.dup_num
[i
- n_ops
];
846 rtx
*loc
= (i
< n_ops
847 ? recog_data
.operand_loc
[opn
]
848 : recog_data
.dup_loc
[i
- n_ops
]);
849 enum reg_class cl
= recog_op_alt
[opn
][alt
].cl
;
850 enum op_type type
= recog_data
.operand_type
[opn
];
852 /* Don't scan match_operand here, since we've no reg class
853 information to pass down. Any operands that we could
854 substitute in will be represented elsewhere. */
855 if (recog_data
.constraints
[opn
][0] == '\0')
858 if (recog_op_alt
[opn
][alt
].is_address
)
859 scan_rtx_address (insn
, loc
, cl
, mark_read
, VOIDmode
);
861 scan_rtx (insn
, loc
, cl
, mark_read
, type
, 0);
864 /* Step 4: Close chains for registers that die here.
865 Also record updates for REG_INC notes. */
866 for (note
= REG_NOTES (insn
); note
; note
= XEXP (note
, 1))
868 if (REG_NOTE_KIND (note
) == REG_DEAD
)
869 scan_rtx (insn
, &XEXP (note
, 0), NO_REGS
, terminate_dead
,
871 else if (REG_NOTE_KIND (note
) == REG_INC
)
872 scan_rtx (insn
, &XEXP (note
, 0), ALL_REGS
, mark_read
,
876 /* Step 4B: If this is a call, any chain live at this point
877 requires a caller-saved reg. */
881 for (p
= open_chains
; p
; p
= p
->next_chain
)
882 p
->need_caller_save_reg
= 1;
885 /* Step 5: Close open chains that overlap writes. Similar to
886 step 2, we hide in-out operands, since we do not want to
887 close these chains. */
889 for (i
= 0; i
< n_ops
; i
++)
891 old_operands
[i
] = recog_data
.operand
[i
];
892 if (recog_data
.operand_type
[i
] == OP_INOUT
)
893 *recog_data
.operand_loc
[i
] = cc0_rtx
;
895 for (i
= 0; i
< recog_data
.n_dups
; i
++)
897 int opn
= recog_data
.dup_num
[i
];
898 old_dups
[i
] = *recog_data
.dup_loc
[i
];
899 if (recog_data
.operand_type
[opn
] == OP_INOUT
)
900 *recog_data
.dup_loc
[i
] = cc0_rtx
;
903 scan_rtx (insn
, &PATTERN (insn
), NO_REGS
, terminate_write
, OP_IN
, 0);
905 for (i
= 0; i
< recog_data
.n_dups
; i
++)
906 *recog_data
.dup_loc
[i
] = old_dups
[i
];
907 for (i
= 0; i
< n_ops
; i
++)
908 *recog_data
.operand_loc
[i
] = old_operands
[i
];
910 /* Step 6: Begin new chains for writes inside operands. */
911 /* ??? Many targets have output constraints on the SET_DEST
912 of a call insn, which is stupid, since these are certainly
913 ABI defined hard registers. Don't change calls at all.
914 Similarly take special care for asm statement that originally
915 referenced hard registers. */
916 if (asm_noperands (PATTERN (insn
)) > 0)
918 for (i
= 0; i
< n_ops
; i
++)
919 if (recog_data
.operand_type
[i
] == OP_OUT
)
921 rtx
*loc
= recog_data
.operand_loc
[i
];
923 enum reg_class cl
= recog_op_alt
[i
][alt
].cl
;
926 && REGNO (op
) == ORIGINAL_REGNO (op
))
929 scan_rtx (insn
, loc
, cl
, mark_write
, OP_OUT
,
930 recog_op_alt
[i
][alt
].earlyclobber
);
933 else if (!CALL_P (insn
))
934 for (i
= 0; i
< n_ops
+ recog_data
.n_dups
; i
++)
936 int opn
= i
< n_ops
? i
: recog_data
.dup_num
[i
- n_ops
];
937 rtx
*loc
= (i
< n_ops
938 ? recog_data
.operand_loc
[opn
]
939 : recog_data
.dup_loc
[i
- n_ops
]);
940 enum reg_class cl
= recog_op_alt
[opn
][alt
].cl
;
942 if (recog_data
.operand_type
[opn
] == OP_OUT
)
943 scan_rtx (insn
, loc
, cl
, mark_write
, OP_OUT
,
944 recog_op_alt
[opn
][alt
].earlyclobber
);
947 /* Step 7: Close chains for registers that were never
949 for (note
= REG_NOTES (insn
); note
; note
= XEXP (note
, 1))
950 if (REG_NOTE_KIND (note
) == REG_UNUSED
)
951 scan_rtx (insn
, &XEXP (note
, 0), NO_REGS
, terminate_dead
,
954 if (insn
== BB_END (bb
))
958 /* Since we close every chain when we find a REG_DEAD note, anything that
959 is still open lives past the basic block, so it can't be renamed. */
960 return closed_chains
;
963 /* Dump all def/use chains in CHAINS to DUMP_FILE. They are
964 printed in reverse order as that's how we build them. */
967 dump_def_use_chain (struct du_chain
*chains
)
971 struct du_chain
*this = chains
;
972 int r
= REGNO (*this->loc
);
973 int nregs
= hard_regno_nregs
[r
][GET_MODE (*this->loc
)];
974 fprintf (dump_file
, "Register %s (%d):", reg_names
[r
], nregs
);
977 fprintf (dump_file
, " %d [%s]", INSN_UID (this->insn
),
978 reg_class_names
[this->cl
]);
979 this = this->next_use
;
981 fprintf (dump_file
, "\n");
982 chains
= chains
->next_chain
;
986 /* The following code does forward propagation of hard register copies.
987 The object is to eliminate as many dependencies as possible, so that
988 we have the most scheduling freedom. As a side effect, we also clean
989 up some silly register allocation decisions made by reload. This
990 code may be obsoleted by a new register allocator. */
992 /* For each register, we have a list of registers that contain the same
993 value. The OLDEST_REGNO field points to the head of the list, and
994 the NEXT_REGNO field runs through the list. The MODE field indicates
995 what mode the data is known to be in; this field is VOIDmode when the
996 register is not known to contain valid data. */
998 struct value_data_entry
1000 enum machine_mode mode
;
1001 unsigned int oldest_regno
;
1002 unsigned int next_regno
;
1007 struct value_data_entry e
[FIRST_PSEUDO_REGISTER
];
1008 unsigned int max_value_regs
;
1011 static void kill_value_one_regno (unsigned, struct value_data
*);
1012 static void kill_value_regno (unsigned, unsigned, struct value_data
*);
1013 static void kill_value (rtx
, struct value_data
*);
1014 static void set_value_regno (unsigned, enum machine_mode
, struct value_data
*);
1015 static void init_value_data (struct value_data
*);
1016 static void kill_clobbered_value (rtx
, rtx
, void *);
1017 static void kill_set_value (rtx
, rtx
, void *);
1018 static int kill_autoinc_value (rtx
*, void *);
1019 static void copy_value (rtx
, rtx
, struct value_data
*);
1020 static bool mode_change_ok (enum machine_mode
, enum machine_mode
,
1022 static rtx
maybe_mode_change (enum machine_mode
, enum machine_mode
,
1023 enum machine_mode
, unsigned int, unsigned int);
1024 static rtx
find_oldest_value_reg (enum reg_class
, rtx
, struct value_data
*);
1025 static bool replace_oldest_value_reg (rtx
*, enum reg_class
, rtx
,
1026 struct value_data
*);
1027 static bool replace_oldest_value_addr (rtx
*, enum reg_class
,
1028 enum machine_mode
, rtx
,
1029 struct value_data
*);
1030 static bool replace_oldest_value_mem (rtx
, rtx
, struct value_data
*);
1031 static bool copyprop_hardreg_forward_1 (basic_block
, struct value_data
*);
1032 extern void debug_value_data (struct value_data
*);
1033 #ifdef ENABLE_CHECKING
1034 static void validate_value_data (struct value_data
*);
1037 /* Kill register REGNO. This involves removing it from any value
1038 lists, and resetting the value mode to VOIDmode. This is only a
1039 helper function; it does not handle any hard registers overlapping
1043 kill_value_one_regno (unsigned int regno
, struct value_data
*vd
)
1045 unsigned int i
, next
;
1047 if (vd
->e
[regno
].oldest_regno
!= regno
)
1049 for (i
= vd
->e
[regno
].oldest_regno
;
1050 vd
->e
[i
].next_regno
!= regno
;
1051 i
= vd
->e
[i
].next_regno
)
1053 vd
->e
[i
].next_regno
= vd
->e
[regno
].next_regno
;
1055 else if ((next
= vd
->e
[regno
].next_regno
) != INVALID_REGNUM
)
1057 for (i
= next
; i
!= INVALID_REGNUM
; i
= vd
->e
[i
].next_regno
)
1058 vd
->e
[i
].oldest_regno
= next
;
1061 vd
->e
[regno
].mode
= VOIDmode
;
1062 vd
->e
[regno
].oldest_regno
= regno
;
1063 vd
->e
[regno
].next_regno
= INVALID_REGNUM
;
1065 #ifdef ENABLE_CHECKING
1066 validate_value_data (vd
);
1070 /* Kill the value in register REGNO for NREGS, and any other registers
1071 whose values overlap. */
1074 kill_value_regno (unsigned int regno
, unsigned int nregs
,
1075 struct value_data
*vd
)
1079 /* Kill the value we're told to kill. */
1080 for (j
= 0; j
< nregs
; ++j
)
1081 kill_value_one_regno (regno
+ j
, vd
);
1083 /* Kill everything that overlapped what we're told to kill. */
1084 if (regno
< vd
->max_value_regs
)
1087 j
= regno
- vd
->max_value_regs
;
1088 for (; j
< regno
; ++j
)
1091 if (vd
->e
[j
].mode
== VOIDmode
)
1093 n
= hard_regno_nregs
[j
][vd
->e
[j
].mode
];
1095 for (i
= 0; i
< n
; ++i
)
1096 kill_value_one_regno (j
+ i
, vd
);
1100 /* Kill X. This is a convenience function wrapping kill_value_regno
1101 so that we mind the mode the register is in. */
1104 kill_value (rtx x
, struct value_data
*vd
)
1108 if (GET_CODE (x
) == SUBREG
)
1110 x
= simplify_subreg (GET_MODE (x
), SUBREG_REG (x
),
1111 GET_MODE (SUBREG_REG (x
)), SUBREG_BYTE (x
));
1113 x
= SUBREG_REG (orig_rtx
);
1117 unsigned int regno
= REGNO (x
);
1118 unsigned int n
= hard_regno_nregs
[regno
][GET_MODE (x
)];
1120 kill_value_regno (regno
, n
, vd
);
1124 /* Remember that REGNO is valid in MODE. */
1127 set_value_regno (unsigned int regno
, enum machine_mode mode
,
1128 struct value_data
*vd
)
1132 vd
->e
[regno
].mode
= mode
;
1134 nregs
= hard_regno_nregs
[regno
][mode
];
1135 if (nregs
> vd
->max_value_regs
)
1136 vd
->max_value_regs
= nregs
;
1139 /* Initialize VD such that there are no known relationships between regs. */
1142 init_value_data (struct value_data
*vd
)
1145 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
1147 vd
->e
[i
].mode
= VOIDmode
;
1148 vd
->e
[i
].oldest_regno
= i
;
1149 vd
->e
[i
].next_regno
= INVALID_REGNUM
;
1151 vd
->max_value_regs
= 0;
1154 /* Called through note_stores. If X is clobbered, kill its value. */
1157 kill_clobbered_value (rtx x
, rtx set
, void *data
)
1159 struct value_data
*vd
= data
;
1160 if (GET_CODE (set
) == CLOBBER
)
1164 /* Called through note_stores. If X is set, not clobbered, kill its
1165 current value and install it as the root of its own value list. */
1168 kill_set_value (rtx x
, rtx set
, void *data
)
1170 struct value_data
*vd
= data
;
1171 if (GET_CODE (set
) != CLOBBER
)
1175 set_value_regno (REGNO (x
), GET_MODE (x
), vd
);
1179 /* Called through for_each_rtx. Kill any register used as the base of an
1180 auto-increment expression, and install that register as the root of its
1184 kill_autoinc_value (rtx
*px
, void *data
)
1187 struct value_data
*vd
= data
;
1189 if (GET_RTX_CLASS (GET_CODE (x
)) == RTX_AUTOINC
)
1193 set_value_regno (REGNO (x
), Pmode
, vd
);
1200 /* Assert that SRC has been copied to DEST. Adjust the data structures
1201 to reflect that SRC contains an older copy of the shared value. */
1204 copy_value (rtx dest
, rtx src
, struct value_data
*vd
)
1206 unsigned int dr
= REGNO (dest
);
1207 unsigned int sr
= REGNO (src
);
1208 unsigned int dn
, sn
;
1211 /* ??? At present, it's possible to see noop sets. It'd be nice if
1212 this were cleaned up beforehand... */
1216 /* Do not propagate copies to the stack pointer, as that can leave
1217 memory accesses with no scheduling dependency on the stack update. */
1218 if (dr
== STACK_POINTER_REGNUM
)
1221 /* Likewise with the frame pointer, if we're using one. */
1222 if (frame_pointer_needed
&& dr
== HARD_FRAME_POINTER_REGNUM
)
1225 /* If SRC and DEST overlap, don't record anything. */
1226 dn
= hard_regno_nregs
[dr
][GET_MODE (dest
)];
1227 sn
= hard_regno_nregs
[sr
][GET_MODE (dest
)];
1228 if ((dr
> sr
&& dr
< sr
+ sn
)
1229 || (sr
> dr
&& sr
< dr
+ dn
))
1232 /* If SRC had no assigned mode (i.e. we didn't know it was live)
1233 assign it now and assume the value came from an input argument
1235 if (vd
->e
[sr
].mode
== VOIDmode
)
1236 set_value_regno (sr
, vd
->e
[dr
].mode
, vd
);
1238 /* If we are narrowing the input to a smaller number of hard regs,
1239 and it is in big endian, we are really extracting a high part.
1240 Since we generally associate a low part of a value with the value itself,
1241 we must not do the same for the high part.
1242 Note we can still get low parts for the same mode combination through
1243 a two-step copy involving differently sized hard regs.
1244 Assume hard regs fr* are 32 bits bits each, while r* are 64 bits each:
1245 (set (reg:DI r0) (reg:DI fr0))
1246 (set (reg:SI fr2) (reg:SI r0))
1247 loads the low part of (reg:DI fr0) - i.e. fr1 - into fr2, while:
1248 (set (reg:SI fr2) (reg:SI fr0))
1249 loads the high part of (reg:DI fr0) into fr2.
1251 We can't properly represent the latter case in our tables, so don't
1252 record anything then. */
1253 else if (sn
< (unsigned int) hard_regno_nregs
[sr
][vd
->e
[sr
].mode
]
1254 && (GET_MODE_SIZE (vd
->e
[sr
].mode
) > UNITS_PER_WORD
1255 ? WORDS_BIG_ENDIAN
: BYTES_BIG_ENDIAN
))
1258 /* If SRC had been assigned a mode narrower than the copy, we can't
1259 link DEST into the chain, because not all of the pieces of the
1260 copy came from oldest_regno. */
1261 else if (sn
> (unsigned int) hard_regno_nregs
[sr
][vd
->e
[sr
].mode
])
1264 /* Link DR at the end of the value chain used by SR. */
1266 vd
->e
[dr
].oldest_regno
= vd
->e
[sr
].oldest_regno
;
1268 for (i
= sr
; vd
->e
[i
].next_regno
!= INVALID_REGNUM
; i
= vd
->e
[i
].next_regno
)
1270 vd
->e
[i
].next_regno
= dr
;
1272 #ifdef ENABLE_CHECKING
1273 validate_value_data (vd
);
1277 /* Return true if a mode change from ORIG to NEW is allowed for REGNO. */
1280 mode_change_ok (enum machine_mode orig_mode
, enum machine_mode new_mode
,
1281 unsigned int regno ATTRIBUTE_UNUSED
)
1283 if (GET_MODE_SIZE (orig_mode
) < GET_MODE_SIZE (new_mode
))
1286 #ifdef CANNOT_CHANGE_MODE_CLASS
1287 return !REG_CANNOT_CHANGE_MODE_P (regno
, orig_mode
, new_mode
);
1293 /* Register REGNO was originally set in ORIG_MODE. It - or a copy of it -
1294 was copied in COPY_MODE to COPY_REGNO, and then COPY_REGNO was accessed
1296 Return a NEW_MODE rtx for REGNO if that's OK, otherwise return NULL_RTX. */
1299 maybe_mode_change (enum machine_mode orig_mode
, enum machine_mode copy_mode
,
1300 enum machine_mode new_mode
, unsigned int regno
,
1301 unsigned int copy_regno ATTRIBUTE_UNUSED
)
1303 if (orig_mode
== new_mode
)
1304 return gen_rtx_raw_REG (new_mode
, regno
);
1305 else if (mode_change_ok (orig_mode
, new_mode
, regno
))
1307 int copy_nregs
= hard_regno_nregs
[copy_regno
][copy_mode
];
1308 int use_nregs
= hard_regno_nregs
[copy_regno
][new_mode
];
1310 = GET_MODE_SIZE (copy_mode
) / copy_nregs
* (copy_nregs
- use_nregs
);
1312 = GET_MODE_SIZE (orig_mode
) - GET_MODE_SIZE (new_mode
) - copy_offset
;
1313 int byteoffset
= offset
% UNITS_PER_WORD
;
1314 int wordoffset
= offset
- byteoffset
;
1316 offset
= ((WORDS_BIG_ENDIAN
? wordoffset
: 0)
1317 + (BYTES_BIG_ENDIAN
? byteoffset
: 0));
1318 return gen_rtx_raw_REG (new_mode
,
1319 regno
+ subreg_regno_offset (regno
, orig_mode
,
1326 /* Find the oldest copy of the value contained in REGNO that is in
1327 register class CL and has mode MODE. If found, return an rtx
1328 of that oldest register, otherwise return NULL. */
1331 find_oldest_value_reg (enum reg_class cl
, rtx reg
, struct value_data
*vd
)
1333 unsigned int regno
= REGNO (reg
);
1334 enum machine_mode mode
= GET_MODE (reg
);
1337 /* If we are accessing REG in some mode other that what we set it in,
1338 make sure that the replacement is valid. In particular, consider
1339 (set (reg:DI r11) (...))
1340 (set (reg:SI r9) (reg:SI r11))
1341 (set (reg:SI r10) (...))
1342 (set (...) (reg:DI r9))
1343 Replacing r9 with r11 is invalid. */
1344 if (mode
!= vd
->e
[regno
].mode
)
1346 if (hard_regno_nregs
[regno
][mode
]
1347 > hard_regno_nregs
[regno
][vd
->e
[regno
].mode
])
1351 for (i
= vd
->e
[regno
].oldest_regno
; i
!= regno
; i
= vd
->e
[i
].next_regno
)
1353 enum machine_mode oldmode
= vd
->e
[i
].mode
;
1357 for (last
= i
; last
< i
+ hard_regno_nregs
[i
][mode
]; last
++)
1358 if (!TEST_HARD_REG_BIT (reg_class_contents
[cl
], last
))
1361 new = maybe_mode_change (oldmode
, vd
->e
[regno
].mode
, mode
, i
, regno
);
1364 ORIGINAL_REGNO (new) = ORIGINAL_REGNO (reg
);
1365 REG_ATTRS (new) = REG_ATTRS (reg
);
1373 /* If possible, replace the register at *LOC with the oldest register
1374 in register class CL. Return true if successfully replaced. */
1377 replace_oldest_value_reg (rtx
*loc
, enum reg_class cl
, rtx insn
,
1378 struct value_data
*vd
)
1380 rtx
new = find_oldest_value_reg (cl
, *loc
, vd
);
1384 fprintf (dump_file
, "insn %u: replaced reg %u with %u\n",
1385 INSN_UID (insn
), REGNO (*loc
), REGNO (new));
1393 /* Similar to replace_oldest_value_reg, but *LOC contains an address.
1394 Adapted from find_reloads_address_1. CL is INDEX_REG_CLASS or
1395 BASE_REG_CLASS depending on how the register is being considered. */
1398 replace_oldest_value_addr (rtx
*loc
, enum reg_class cl
,
1399 enum machine_mode mode
, rtx insn
,
1400 struct value_data
*vd
)
1403 RTX_CODE code
= GET_CODE (x
);
1406 bool changed
= false;
1412 rtx orig_op0
= XEXP (x
, 0);
1413 rtx orig_op1
= XEXP (x
, 1);
1414 RTX_CODE code0
= GET_CODE (orig_op0
);
1415 RTX_CODE code1
= GET_CODE (orig_op1
);
1420 rtx
*locB_reg
= NULL
;
1422 if (GET_CODE (op0
) == SUBREG
)
1424 op0
= SUBREG_REG (op0
);
1425 code0
= GET_CODE (op0
);
1428 if (GET_CODE (op1
) == SUBREG
)
1430 op1
= SUBREG_REG (op1
);
1431 code1
= GET_CODE (op1
);
1434 if (code0
== MULT
|| code0
== SIGN_EXTEND
|| code0
== TRUNCATE
1435 || code0
== ZERO_EXTEND
|| code1
== MEM
)
1437 locI
= &XEXP (x
, 0);
1438 locB
= &XEXP (x
, 1);
1440 else if (code1
== MULT
|| code1
== SIGN_EXTEND
|| code1
== TRUNCATE
1441 || code1
== ZERO_EXTEND
|| code0
== MEM
)
1443 locI
= &XEXP (x
, 1);
1444 locB
= &XEXP (x
, 0);
1446 else if (code0
== CONST_INT
|| code0
== CONST
1447 || code0
== SYMBOL_REF
|| code0
== LABEL_REF
)
1448 locB
= &XEXP (x
, 1);
1449 else if (code1
== CONST_INT
|| code1
== CONST
1450 || code1
== SYMBOL_REF
|| code1
== LABEL_REF
)
1451 locB
= &XEXP (x
, 0);
1452 else if (code0
== REG
&& code1
== REG
)
1456 if (REG_OK_FOR_INDEX_P (op0
)
1457 && REG_MODE_OK_FOR_REG_BASE_P (op1
, mode
))
1459 else if (REG_OK_FOR_INDEX_P (op1
)
1460 && REG_MODE_OK_FOR_REG_BASE_P (op0
, mode
))
1462 else if (REG_MODE_OK_FOR_REG_BASE_P (op1
, mode
))
1464 else if (REG_MODE_OK_FOR_REG_BASE_P (op0
, mode
))
1466 else if (REG_OK_FOR_INDEX_P (op1
))
1471 locI
= &XEXP (x
, index_op
);
1472 locB_reg
= &XEXP (x
, !index_op
);
1474 else if (code0
== REG
)
1476 locI
= &XEXP (x
, 0);
1477 locB
= &XEXP (x
, 1);
1479 else if (code1
== REG
)
1481 locI
= &XEXP (x
, 1);
1482 locB
= &XEXP (x
, 0);
1486 changed
|= replace_oldest_value_addr (locI
, INDEX_REG_CLASS
, mode
,
1489 changed
|= replace_oldest_value_addr (locB
,
1490 MODE_BASE_REG_CLASS (mode
),
1493 changed
|= replace_oldest_value_addr (locB_reg
,
1494 MODE_BASE_REG_REG_CLASS (mode
),
1508 return replace_oldest_value_mem (x
, insn
, vd
);
1511 return replace_oldest_value_reg (loc
, cl
, insn
, vd
);
1517 fmt
= GET_RTX_FORMAT (code
);
1518 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
1521 changed
|= replace_oldest_value_addr (&XEXP (x
, i
), cl
, mode
,
1523 else if (fmt
[i
] == 'E')
1524 for (j
= XVECLEN (x
, i
) - 1; j
>= 0; j
--)
1525 changed
|= replace_oldest_value_addr (&XVECEXP (x
, i
, j
), cl
,
1532 /* Similar to replace_oldest_value_reg, but X contains a memory. */
1535 replace_oldest_value_mem (rtx x
, rtx insn
, struct value_data
*vd
)
1537 return replace_oldest_value_addr (&XEXP (x
, 0),
1538 MODE_BASE_REG_CLASS (GET_MODE (x
)),
1539 GET_MODE (x
), insn
, vd
);
1542 /* Perform the forward copy propagation on basic block BB. */
1545 copyprop_hardreg_forward_1 (basic_block bb
, struct value_data
*vd
)
1547 bool changed
= false;
1550 for (insn
= BB_HEAD (bb
); ; insn
= NEXT_INSN (insn
))
1552 int n_ops
, i
, alt
, predicated
;
1556 if (! INSN_P (insn
))
1558 if (insn
== BB_END (bb
))
1564 set
= single_set (insn
);
1565 extract_insn (insn
);
1566 if (! constrain_operands (1))
1567 fatal_insn_not_found (insn
);
1568 preprocess_constraints ();
1569 alt
= which_alternative
;
1570 n_ops
= recog_data
.n_operands
;
1571 is_asm
= asm_noperands (PATTERN (insn
)) >= 0;
1573 /* Simplify the code below by rewriting things to reflect
1574 matching constraints. Also promote OP_OUT to OP_INOUT
1575 in predicated instructions. */
1577 predicated
= GET_CODE (PATTERN (insn
)) == COND_EXEC
;
1578 for (i
= 0; i
< n_ops
; ++i
)
1580 int matches
= recog_op_alt
[i
][alt
].matches
;
1582 recog_op_alt
[i
][alt
].cl
= recog_op_alt
[matches
][alt
].cl
;
1583 if (matches
>= 0 || recog_op_alt
[i
][alt
].matched
>= 0
1584 || (predicated
&& recog_data
.operand_type
[i
] == OP_OUT
))
1585 recog_data
.operand_type
[i
] = OP_INOUT
;
1588 /* For each earlyclobber operand, zap the value data. */
1589 for (i
= 0; i
< n_ops
; i
++)
1590 if (recog_op_alt
[i
][alt
].earlyclobber
)
1591 kill_value (recog_data
.operand
[i
], vd
);
1593 /* Within asms, a clobber cannot overlap inputs or outputs.
1594 I wouldn't think this were true for regular insns, but
1595 scan_rtx treats them like that... */
1596 note_stores (PATTERN (insn
), kill_clobbered_value
, vd
);
1598 /* Kill all auto-incremented values. */
1599 /* ??? REG_INC is useless, since stack pushes aren't done that way. */
1600 for_each_rtx (&PATTERN (insn
), kill_autoinc_value
, vd
);
1602 /* Kill all early-clobbered operands. */
1603 for (i
= 0; i
< n_ops
; i
++)
1604 if (recog_op_alt
[i
][alt
].earlyclobber
)
1605 kill_value (recog_data
.operand
[i
], vd
);
1607 /* Special-case plain move instructions, since we may well
1608 be able to do the move from a different register class. */
1609 if (set
&& REG_P (SET_SRC (set
)))
1611 rtx src
= SET_SRC (set
);
1612 unsigned int regno
= REGNO (src
);
1613 enum machine_mode mode
= GET_MODE (src
);
1617 /* If we are accessing SRC in some mode other that what we
1618 set it in, make sure that the replacement is valid. */
1619 if (mode
!= vd
->e
[regno
].mode
)
1621 if (hard_regno_nregs
[regno
][mode
]
1622 > hard_regno_nregs
[regno
][vd
->e
[regno
].mode
])
1623 goto no_move_special_case
;
1626 /* If the destination is also a register, try to find a source
1627 register in the same class. */
1628 if (REG_P (SET_DEST (set
)))
1630 new = find_oldest_value_reg (REGNO_REG_CLASS (regno
), src
, vd
);
1631 if (new && validate_change (insn
, &SET_SRC (set
), new, 0))
1635 "insn %u: replaced reg %u with %u\n",
1636 INSN_UID (insn
), regno
, REGNO (new));
1638 goto did_replacement
;
1642 /* Otherwise, try all valid registers and see if its valid. */
1643 for (i
= vd
->e
[regno
].oldest_regno
; i
!= regno
;
1644 i
= vd
->e
[i
].next_regno
)
1646 new = maybe_mode_change (vd
->e
[i
].mode
, vd
->e
[regno
].mode
,
1648 if (new != NULL_RTX
)
1650 if (validate_change (insn
, &SET_SRC (set
), new, 0))
1652 ORIGINAL_REGNO (new) = ORIGINAL_REGNO (src
);
1653 REG_ATTRS (new) = REG_ATTRS (src
);
1656 "insn %u: replaced reg %u with %u\n",
1657 INSN_UID (insn
), regno
, REGNO (new));
1659 goto did_replacement
;
1664 no_move_special_case
:
1666 /* For each input operand, replace a hard register with the
1667 eldest live copy that's in an appropriate register class. */
1668 for (i
= 0; i
< n_ops
; i
++)
1670 bool replaced
= false;
1672 /* Don't scan match_operand here, since we've no reg class
1673 information to pass down. Any operands that we could
1674 substitute in will be represented elsewhere. */
1675 if (recog_data
.constraints
[i
][0] == '\0')
1678 /* Don't replace in asms intentionally referencing hard regs. */
1679 if (is_asm
&& REG_P (recog_data
.operand
[i
])
1680 && (REGNO (recog_data
.operand
[i
])
1681 == ORIGINAL_REGNO (recog_data
.operand
[i
])))
1684 if (recog_data
.operand_type
[i
] == OP_IN
)
1686 if (recog_op_alt
[i
][alt
].is_address
)
1688 = replace_oldest_value_addr (recog_data
.operand_loc
[i
],
1689 recog_op_alt
[i
][alt
].cl
,
1690 VOIDmode
, insn
, vd
);
1691 else if (REG_P (recog_data
.operand
[i
]))
1693 = replace_oldest_value_reg (recog_data
.operand_loc
[i
],
1694 recog_op_alt
[i
][alt
].cl
,
1696 else if (MEM_P (recog_data
.operand
[i
]))
1697 replaced
= replace_oldest_value_mem (recog_data
.operand
[i
],
1700 else if (MEM_P (recog_data
.operand
[i
]))
1701 replaced
= replace_oldest_value_mem (recog_data
.operand
[i
],
1704 /* If we performed any replacement, update match_dups. */
1712 new = *recog_data
.operand_loc
[i
];
1713 recog_data
.operand
[i
] = new;
1714 for (j
= 0; j
< recog_data
.n_dups
; j
++)
1715 if (recog_data
.dup_num
[j
] == i
)
1716 *recog_data
.dup_loc
[j
] = new;
1721 /* Clobber call-clobbered registers. */
1723 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; i
++)
1724 if (TEST_HARD_REG_BIT (regs_invalidated_by_call
, i
))
1725 kill_value_regno (i
, 1, vd
);
1727 /* Notice stores. */
1728 note_stores (PATTERN (insn
), kill_set_value
, vd
);
1730 /* Notice copies. */
1731 if (set
&& REG_P (SET_DEST (set
)) && REG_P (SET_SRC (set
)))
1732 copy_value (SET_DEST (set
), SET_SRC (set
), vd
);
1734 if (insn
== BB_END (bb
))
1741 /* Main entry point for the forward copy propagation optimization. */
1744 copyprop_hardreg_forward (void)
1746 struct value_data
*all_vd
;
1751 need_refresh
= false;
1753 all_vd
= xmalloc (sizeof (struct value_data
) * last_basic_block
);
1755 visited
= sbitmap_alloc (last_basic_block
- (INVALID_BLOCK
+ 1));
1756 sbitmap_zero (visited
);
1760 SET_BIT (visited
, bb
->index
- (INVALID_BLOCK
+ 1));
1762 /* If a block has a single predecessor, that we've already
1763 processed, begin with the value data that was live at
1764 the end of the predecessor block. */
1765 /* ??? Ought to use more intelligent queuing of blocks. */
1766 if (EDGE_COUNT (bb
->preds
) == 1
1767 && TEST_BIT (visited
,
1768 EDGE_PRED (bb
, 0)->src
->index
- (INVALID_BLOCK
+ 1))
1769 && ! (EDGE_PRED (bb
, 0)->flags
& (EDGE_ABNORMAL_CALL
| EDGE_EH
)))
1770 all_vd
[bb
->index
] = all_vd
[EDGE_PRED (bb
, 0)->src
->index
];
1772 init_value_data (all_vd
+ bb
->index
);
1774 if (copyprop_hardreg_forward_1 (bb
, all_vd
+ bb
->index
))
1775 need_refresh
= true;
1778 sbitmap_free (visited
);
1783 fputs ("\n\n", dump_file
);
1785 /* ??? Irritatingly, delete_noop_moves does not take a set of blocks
1786 to scan, so we have to do a life update with no initial set of
1787 blocks Just In Case. */
1788 delete_noop_moves ();
1789 update_life_info (NULL
, UPDATE_LIFE_GLOBAL_RM_NOTES
,
1791 | PROP_SCAN_DEAD_CODE
1792 | PROP_KILL_DEAD_CODE
);
1798 /* Dump the value chain data to stderr. */
1801 debug_value_data (struct value_data
*vd
)
1806 CLEAR_HARD_REG_SET (set
);
1808 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
1809 if (vd
->e
[i
].oldest_regno
== i
)
1811 if (vd
->e
[i
].mode
== VOIDmode
)
1813 if (vd
->e
[i
].next_regno
!= INVALID_REGNUM
)
1814 fprintf (stderr
, "[%u] Bad next_regno for empty chain (%u)\n",
1815 i
, vd
->e
[i
].next_regno
);
1819 SET_HARD_REG_BIT (set
, i
);
1820 fprintf (stderr
, "[%u %s] ", i
, GET_MODE_NAME (vd
->e
[i
].mode
));
1822 for (j
= vd
->e
[i
].next_regno
;
1823 j
!= INVALID_REGNUM
;
1824 j
= vd
->e
[j
].next_regno
)
1826 if (TEST_HARD_REG_BIT (set
, j
))
1828 fprintf (stderr
, "[%u] Loop in regno chain\n", j
);
1832 if (vd
->e
[j
].oldest_regno
!= i
)
1834 fprintf (stderr
, "[%u] Bad oldest_regno (%u)\n",
1835 j
, vd
->e
[j
].oldest_regno
);
1838 SET_HARD_REG_BIT (set
, j
);
1839 fprintf (stderr
, "[%u %s] ", j
, GET_MODE_NAME (vd
->e
[j
].mode
));
1841 fputc ('\n', stderr
);
1844 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
1845 if (! TEST_HARD_REG_BIT (set
, i
)
1846 && (vd
->e
[i
].mode
!= VOIDmode
1847 || vd
->e
[i
].oldest_regno
!= i
1848 || vd
->e
[i
].next_regno
!= INVALID_REGNUM
))
1849 fprintf (stderr
, "[%u] Non-empty reg in chain (%s %u %i)\n",
1850 i
, GET_MODE_NAME (vd
->e
[i
].mode
), vd
->e
[i
].oldest_regno
,
1851 vd
->e
[i
].next_regno
);
1854 #ifdef ENABLE_CHECKING
1856 validate_value_data (struct value_data
*vd
)
1861 CLEAR_HARD_REG_SET (set
);
1863 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
1864 if (vd
->e
[i
].oldest_regno
== i
)
1866 if (vd
->e
[i
].mode
== VOIDmode
)
1868 if (vd
->e
[i
].next_regno
!= INVALID_REGNUM
)
1869 internal_error ("validate_value_data: [%u] Bad next_regno for empty chain (%u)",
1870 i
, vd
->e
[i
].next_regno
);
1874 SET_HARD_REG_BIT (set
, i
);
1876 for (j
= vd
->e
[i
].next_regno
;
1877 j
!= INVALID_REGNUM
;
1878 j
= vd
->e
[j
].next_regno
)
1880 if (TEST_HARD_REG_BIT (set
, j
))
1881 internal_error ("validate_value_data: Loop in regno chain (%u)",
1883 if (vd
->e
[j
].oldest_regno
!= i
)
1884 internal_error ("validate_value_data: [%u] Bad oldest_regno (%u)",
1885 j
, vd
->e
[j
].oldest_regno
);
1887 SET_HARD_REG_BIT (set
, j
);
1891 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
1892 if (! TEST_HARD_REG_BIT (set
, i
)
1893 && (vd
->e
[i
].mode
!= VOIDmode
1894 || vd
->e
[i
].oldest_regno
!= i
1895 || vd
->e
[i
].next_regno
!= INVALID_REGNUM
))
1896 internal_error ("validate_value_data: [%u] Non-empty reg in chain (%s %u %i)",
1897 i
, GET_MODE_NAME (vd
->e
[i
].mode
), vd
->e
[i
].oldest_regno
,
1898 vd
->e
[i
].next_regno
);