1 /* Copy propagation on hard registers for the GNU compiler.
2 Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
3 2010 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 3, 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 COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
23 #include "coretypes.h"
27 #include "insn-config.h"
29 #include "addresses.h"
30 #include "hard-reg-set.h"
31 #include "basic-block.h"
37 #include "diagnostic-core.h"
40 #include "tree-pass.h"
43 /* The following code does forward propagation of hard register copies.
44 The object is to eliminate as many dependencies as possible, so that
45 we have the most scheduling freedom. As a side effect, we also clean
46 up some silly register allocation decisions made by reload. This
47 code may be obsoleted by a new register allocator. */
49 /* DEBUG_INSNs aren't changed right away, as doing so might extend the
50 lifetime of a register and get the DEBUG_INSN subsequently reset.
51 So they are queued instead, and updated only when the register is
52 used in some subsequent real insn before it is set. */
53 struct queued_debug_insn_change
55 struct queued_debug_insn_change
*next
;
61 /* For each register, we have a list of registers that contain the same
62 value. The OLDEST_REGNO field points to the head of the list, and
63 the NEXT_REGNO field runs through the list. The MODE field indicates
64 what mode the data is known to be in; this field is VOIDmode when the
65 register is not known to contain valid data. */
67 struct value_data_entry
69 enum machine_mode mode
;
70 unsigned int oldest_regno
;
71 unsigned int next_regno
;
72 struct queued_debug_insn_change
*debug_insn_changes
;
77 struct value_data_entry e
[FIRST_PSEUDO_REGISTER
];
78 unsigned int max_value_regs
;
79 unsigned int n_debug_insn_changes
;
82 static alloc_pool debug_insn_changes_pool
;
84 static void kill_value_one_regno (unsigned, struct value_data
*);
85 static void kill_value_regno (unsigned, unsigned, struct value_data
*);
86 static void kill_value (rtx
, struct value_data
*);
87 static void set_value_regno (unsigned, enum machine_mode
, struct value_data
*);
88 static void init_value_data (struct value_data
*);
89 static void kill_clobbered_value (rtx
, const_rtx
, void *);
90 static void kill_set_value (rtx
, const_rtx
, void *);
91 static int kill_autoinc_value (rtx
*, void *);
92 static void copy_value (rtx
, rtx
, struct value_data
*);
93 static bool mode_change_ok (enum machine_mode
, enum machine_mode
,
95 static rtx
maybe_mode_change (enum machine_mode
, enum machine_mode
,
96 enum machine_mode
, unsigned int, unsigned int);
97 static rtx
find_oldest_value_reg (enum reg_class
, rtx
, struct value_data
*);
98 static bool replace_oldest_value_reg (rtx
*, enum reg_class
, rtx
,
100 static bool replace_oldest_value_addr (rtx
*, enum reg_class
,
101 enum machine_mode
, addr_space_t
, rtx
,
102 struct value_data
*);
103 static bool replace_oldest_value_mem (rtx
, rtx
, struct value_data
*);
104 static bool copyprop_hardreg_forward_1 (basic_block
, struct value_data
*);
105 extern void debug_value_data (struct value_data
*);
106 #ifdef ENABLE_CHECKING
107 static void validate_value_data (struct value_data
*);
110 /* Free all queued updates for DEBUG_INSNs that change some reg to
114 free_debug_insn_changes (struct value_data
*vd
, unsigned int regno
)
116 struct queued_debug_insn_change
*cur
, *next
;
117 for (cur
= vd
->e
[regno
].debug_insn_changes
; cur
; cur
= next
)
120 --vd
->n_debug_insn_changes
;
121 pool_free (debug_insn_changes_pool
, cur
);
123 vd
->e
[regno
].debug_insn_changes
= NULL
;
126 /* Kill register REGNO. This involves removing it from any value
127 lists, and resetting the value mode to VOIDmode. This is only a
128 helper function; it does not handle any hard registers overlapping
132 kill_value_one_regno (unsigned int regno
, struct value_data
*vd
)
134 unsigned int i
, next
;
136 if (vd
->e
[regno
].oldest_regno
!= regno
)
138 for (i
= vd
->e
[regno
].oldest_regno
;
139 vd
->e
[i
].next_regno
!= regno
;
140 i
= vd
->e
[i
].next_regno
)
142 vd
->e
[i
].next_regno
= vd
->e
[regno
].next_regno
;
144 else if ((next
= vd
->e
[regno
].next_regno
) != INVALID_REGNUM
)
146 for (i
= next
; i
!= INVALID_REGNUM
; i
= vd
->e
[i
].next_regno
)
147 vd
->e
[i
].oldest_regno
= next
;
150 vd
->e
[regno
].mode
= VOIDmode
;
151 vd
->e
[regno
].oldest_regno
= regno
;
152 vd
->e
[regno
].next_regno
= INVALID_REGNUM
;
153 if (vd
->e
[regno
].debug_insn_changes
)
154 free_debug_insn_changes (vd
, regno
);
156 #ifdef ENABLE_CHECKING
157 validate_value_data (vd
);
161 /* Kill the value in register REGNO for NREGS, and any other registers
162 whose values overlap. */
165 kill_value_regno (unsigned int regno
, unsigned int nregs
,
166 struct value_data
*vd
)
170 /* Kill the value we're told to kill. */
171 for (j
= 0; j
< nregs
; ++j
)
172 kill_value_one_regno (regno
+ j
, vd
);
174 /* Kill everything that overlapped what we're told to kill. */
175 if (regno
< vd
->max_value_regs
)
178 j
= regno
- vd
->max_value_regs
;
179 for (; j
< regno
; ++j
)
182 if (vd
->e
[j
].mode
== VOIDmode
)
184 n
= hard_regno_nregs
[j
][vd
->e
[j
].mode
];
186 for (i
= 0; i
< n
; ++i
)
187 kill_value_one_regno (j
+ i
, vd
);
191 /* Kill X. This is a convenience function wrapping kill_value_regno
192 so that we mind the mode the register is in. */
195 kill_value (rtx x
, struct value_data
*vd
)
199 if (GET_CODE (x
) == SUBREG
)
201 x
= simplify_subreg (GET_MODE (x
), SUBREG_REG (x
),
202 GET_MODE (SUBREG_REG (x
)), SUBREG_BYTE (x
));
204 x
= SUBREG_REG (orig_rtx
);
208 unsigned int regno
= REGNO (x
);
209 unsigned int n
= hard_regno_nregs
[regno
][GET_MODE (x
)];
211 kill_value_regno (regno
, n
, vd
);
215 /* Remember that REGNO is valid in MODE. */
218 set_value_regno (unsigned int regno
, enum machine_mode mode
,
219 struct value_data
*vd
)
223 vd
->e
[regno
].mode
= mode
;
225 nregs
= hard_regno_nregs
[regno
][mode
];
226 if (nregs
> vd
->max_value_regs
)
227 vd
->max_value_regs
= nregs
;
230 /* Initialize VD such that there are no known relationships between regs. */
233 init_value_data (struct value_data
*vd
)
236 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
238 vd
->e
[i
].mode
= VOIDmode
;
239 vd
->e
[i
].oldest_regno
= i
;
240 vd
->e
[i
].next_regno
= INVALID_REGNUM
;
241 vd
->e
[i
].debug_insn_changes
= NULL
;
243 vd
->max_value_regs
= 0;
244 vd
->n_debug_insn_changes
= 0;
247 /* Called through note_stores. If X is clobbered, kill its value. */
250 kill_clobbered_value (rtx x
, const_rtx set
, void *data
)
252 struct value_data
*const vd
= (struct value_data
*) data
;
253 if (GET_CODE (set
) == CLOBBER
)
257 /* Called through note_stores. If X is set, not clobbered, kill its
258 current value and install it as the root of its own value list. */
261 kill_set_value (rtx x
, const_rtx set
, void *data
)
263 struct value_data
*const vd
= (struct value_data
*) data
;
264 if (GET_CODE (set
) != CLOBBER
)
268 set_value_regno (REGNO (x
), GET_MODE (x
), vd
);
272 /* Called through for_each_rtx. Kill any register used as the base of an
273 auto-increment expression, and install that register as the root of its
277 kill_autoinc_value (rtx
*px
, void *data
)
280 struct value_data
*const vd
= (struct value_data
*) data
;
282 if (GET_RTX_CLASS (GET_CODE (x
)) == RTX_AUTOINC
)
286 set_value_regno (REGNO (x
), GET_MODE (x
), vd
);
293 /* Assert that SRC has been copied to DEST. Adjust the data structures
294 to reflect that SRC contains an older copy of the shared value. */
297 copy_value (rtx dest
, rtx src
, struct value_data
*vd
)
299 unsigned int dr
= REGNO (dest
);
300 unsigned int sr
= REGNO (src
);
304 /* ??? At present, it's possible to see noop sets. It'd be nice if
305 this were cleaned up beforehand... */
309 /* Do not propagate copies to the stack pointer, as that can leave
310 memory accesses with no scheduling dependency on the stack update. */
311 if (dr
== STACK_POINTER_REGNUM
)
314 /* Likewise with the frame pointer, if we're using one. */
315 if (frame_pointer_needed
&& dr
== HARD_FRAME_POINTER_REGNUM
)
318 /* Do not propagate copies to fixed or global registers, patterns
319 can be relying to see particular fixed register or users can
320 expect the chosen global register in asm. */
321 if (fixed_regs
[dr
] || global_regs
[dr
])
324 /* If SRC and DEST overlap, don't record anything. */
325 dn
= hard_regno_nregs
[dr
][GET_MODE (dest
)];
326 sn
= hard_regno_nregs
[sr
][GET_MODE (dest
)];
327 if ((dr
> sr
&& dr
< sr
+ sn
)
328 || (sr
> dr
&& sr
< dr
+ dn
))
331 /* If SRC had no assigned mode (i.e. we didn't know it was live)
332 assign it now and assume the value came from an input argument
334 if (vd
->e
[sr
].mode
== VOIDmode
)
335 set_value_regno (sr
, vd
->e
[dr
].mode
, vd
);
337 /* If we are narrowing the input to a smaller number of hard regs,
338 and it is in big endian, we are really extracting a high part.
339 Since we generally associate a low part of a value with the value itself,
340 we must not do the same for the high part.
341 Note we can still get low parts for the same mode combination through
342 a two-step copy involving differently sized hard regs.
343 Assume hard regs fr* are 32 bits bits each, while r* are 64 bits each:
344 (set (reg:DI r0) (reg:DI fr0))
345 (set (reg:SI fr2) (reg:SI r0))
346 loads the low part of (reg:DI fr0) - i.e. fr1 - into fr2, while:
347 (set (reg:SI fr2) (reg:SI fr0))
348 loads the high part of (reg:DI fr0) into fr2.
350 We can't properly represent the latter case in our tables, so don't
351 record anything then. */
352 else if (sn
< (unsigned int) hard_regno_nregs
[sr
][vd
->e
[sr
].mode
]
353 && (GET_MODE_SIZE (vd
->e
[sr
].mode
) > UNITS_PER_WORD
354 ? WORDS_BIG_ENDIAN
: BYTES_BIG_ENDIAN
))
357 /* If SRC had been assigned a mode narrower than the copy, we can't
358 link DEST into the chain, because not all of the pieces of the
359 copy came from oldest_regno. */
360 else if (sn
> (unsigned int) hard_regno_nregs
[sr
][vd
->e
[sr
].mode
])
363 /* Link DR at the end of the value chain used by SR. */
365 vd
->e
[dr
].oldest_regno
= vd
->e
[sr
].oldest_regno
;
367 for (i
= sr
; vd
->e
[i
].next_regno
!= INVALID_REGNUM
; i
= vd
->e
[i
].next_regno
)
369 vd
->e
[i
].next_regno
= dr
;
371 #ifdef ENABLE_CHECKING
372 validate_value_data (vd
);
376 /* Return true if a mode change from ORIG to NEW is allowed for REGNO. */
379 mode_change_ok (enum machine_mode orig_mode
, enum machine_mode new_mode
,
380 unsigned int regno ATTRIBUTE_UNUSED
)
382 if (GET_MODE_SIZE (orig_mode
) < GET_MODE_SIZE (new_mode
))
385 #ifdef CANNOT_CHANGE_MODE_CLASS
386 return !REG_CANNOT_CHANGE_MODE_P (regno
, orig_mode
, new_mode
);
392 /* Register REGNO was originally set in ORIG_MODE. It - or a copy of it -
393 was copied in COPY_MODE to COPY_REGNO, and then COPY_REGNO was accessed
395 Return a NEW_MODE rtx for REGNO if that's OK, otherwise return NULL_RTX. */
398 maybe_mode_change (enum machine_mode orig_mode
, enum machine_mode copy_mode
,
399 enum machine_mode new_mode
, unsigned int regno
,
400 unsigned int copy_regno ATTRIBUTE_UNUSED
)
402 if (GET_MODE_SIZE (copy_mode
) < GET_MODE_SIZE (orig_mode
)
403 && GET_MODE_SIZE (copy_mode
) < GET_MODE_SIZE (new_mode
))
406 if (orig_mode
== new_mode
)
407 return gen_rtx_raw_REG (new_mode
, regno
);
408 else if (mode_change_ok (orig_mode
, new_mode
, regno
))
410 int copy_nregs
= hard_regno_nregs
[copy_regno
][copy_mode
];
411 int use_nregs
= hard_regno_nregs
[copy_regno
][new_mode
];
413 = GET_MODE_SIZE (copy_mode
) / copy_nregs
* (copy_nregs
- use_nregs
);
415 = GET_MODE_SIZE (orig_mode
) - GET_MODE_SIZE (new_mode
) - copy_offset
;
416 int byteoffset
= offset
% UNITS_PER_WORD
;
417 int wordoffset
= offset
- byteoffset
;
419 offset
= ((WORDS_BIG_ENDIAN
? wordoffset
: 0)
420 + (BYTES_BIG_ENDIAN
? byteoffset
: 0));
421 regno
+= subreg_regno_offset (regno
, orig_mode
, offset
, new_mode
);
422 if (HARD_REGNO_MODE_OK (regno
, new_mode
))
423 return gen_rtx_raw_REG (new_mode
, regno
);
428 /* Find the oldest copy of the value contained in REGNO that is in
429 register class CL and has mode MODE. If found, return an rtx
430 of that oldest register, otherwise return NULL. */
433 find_oldest_value_reg (enum reg_class cl
, rtx reg
, struct value_data
*vd
)
435 unsigned int regno
= REGNO (reg
);
436 enum machine_mode mode
= GET_MODE (reg
);
439 /* If we are accessing REG in some mode other that what we set it in,
440 make sure that the replacement is valid. In particular, consider
441 (set (reg:DI r11) (...))
442 (set (reg:SI r9) (reg:SI r11))
443 (set (reg:SI r10) (...))
444 (set (...) (reg:DI r9))
445 Replacing r9 with r11 is invalid. */
446 if (mode
!= vd
->e
[regno
].mode
)
448 if (hard_regno_nregs
[regno
][mode
]
449 > hard_regno_nregs
[regno
][vd
->e
[regno
].mode
])
453 for (i
= vd
->e
[regno
].oldest_regno
; i
!= regno
; i
= vd
->e
[i
].next_regno
)
455 enum machine_mode oldmode
= vd
->e
[i
].mode
;
458 if (!in_hard_reg_set_p (reg_class_contents
[cl
], mode
, i
))
461 new_rtx
= maybe_mode_change (oldmode
, vd
->e
[regno
].mode
, mode
, i
, regno
);
464 ORIGINAL_REGNO (new_rtx
) = ORIGINAL_REGNO (reg
);
465 REG_ATTRS (new_rtx
) = REG_ATTRS (reg
);
466 REG_POINTER (new_rtx
) = REG_POINTER (reg
);
474 /* If possible, replace the register at *LOC with the oldest register
475 in register class CL. Return true if successfully replaced. */
478 replace_oldest_value_reg (rtx
*loc
, enum reg_class cl
, rtx insn
,
479 struct value_data
*vd
)
481 rtx new_rtx
= find_oldest_value_reg (cl
, *loc
, vd
);
484 if (DEBUG_INSN_P (insn
))
486 struct queued_debug_insn_change
*change
;
489 fprintf (dump_file
, "debug_insn %u: queued replacing reg %u with %u\n",
490 INSN_UID (insn
), REGNO (*loc
), REGNO (new_rtx
));
492 change
= (struct queued_debug_insn_change
*)
493 pool_alloc (debug_insn_changes_pool
);
494 change
->next
= vd
->e
[REGNO (new_rtx
)].debug_insn_changes
;
497 change
->new_rtx
= new_rtx
;
498 vd
->e
[REGNO (new_rtx
)].debug_insn_changes
= change
;
499 ++vd
->n_debug_insn_changes
;
503 fprintf (dump_file
, "insn %u: replaced reg %u with %u\n",
504 INSN_UID (insn
), REGNO (*loc
), REGNO (new_rtx
));
506 validate_change (insn
, loc
, new_rtx
, 1);
512 /* Similar to replace_oldest_value_reg, but *LOC contains an address.
513 Adapted from find_reloads_address_1. CL is INDEX_REG_CLASS or
514 BASE_REG_CLASS depending on how the register is being considered. */
517 replace_oldest_value_addr (rtx
*loc
, enum reg_class cl
,
518 enum machine_mode mode
, addr_space_t as
,
519 rtx insn
, struct value_data
*vd
)
522 RTX_CODE code
= GET_CODE (x
);
525 bool changed
= false;
530 if (DEBUG_INSN_P (insn
))
534 rtx orig_op0
= XEXP (x
, 0);
535 rtx orig_op1
= XEXP (x
, 1);
536 RTX_CODE code0
= GET_CODE (orig_op0
);
537 RTX_CODE code1
= GET_CODE (orig_op1
);
542 enum rtx_code index_code
= SCRATCH
;
544 if (GET_CODE (op0
) == SUBREG
)
546 op0
= SUBREG_REG (op0
);
547 code0
= GET_CODE (op0
);
550 if (GET_CODE (op1
) == SUBREG
)
552 op1
= SUBREG_REG (op1
);
553 code1
= GET_CODE (op1
);
556 if (code0
== MULT
|| code0
== SIGN_EXTEND
|| code0
== TRUNCATE
557 || code0
== ZERO_EXTEND
|| code1
== MEM
)
561 index_code
= GET_CODE (*locI
);
563 else if (code1
== MULT
|| code1
== SIGN_EXTEND
|| code1
== TRUNCATE
564 || code1
== ZERO_EXTEND
|| code0
== MEM
)
568 index_code
= GET_CODE (*locI
);
570 else if (code0
== CONST_INT
|| code0
== CONST
571 || code0
== SYMBOL_REF
|| code0
== LABEL_REF
)
574 index_code
= GET_CODE (XEXP (x
, 0));
576 else if (code1
== CONST_INT
|| code1
== CONST
577 || code1
== SYMBOL_REF
|| code1
== LABEL_REF
)
580 index_code
= GET_CODE (XEXP (x
, 1));
582 else if (code0
== REG
&& code1
== REG
)
585 unsigned regno0
= REGNO (op0
), regno1
= REGNO (op1
);
587 if (REGNO_OK_FOR_INDEX_P (regno1
)
588 && regno_ok_for_base_p (regno0
, mode
, as
, PLUS
, REG
))
590 else if (REGNO_OK_FOR_INDEX_P (regno0
)
591 && regno_ok_for_base_p (regno1
, mode
, as
, PLUS
, REG
))
593 else if (regno_ok_for_base_p (regno0
, mode
, as
, PLUS
, REG
)
594 || REGNO_OK_FOR_INDEX_P (regno1
))
596 else if (regno_ok_for_base_p (regno1
, mode
, as
, PLUS
, REG
))
601 locI
= &XEXP (x
, index_op
);
602 locB
= &XEXP (x
, !index_op
);
603 index_code
= GET_CODE (*locI
);
605 else if (code0
== REG
)
609 index_code
= GET_CODE (*locI
);
611 else if (code1
== REG
)
615 index_code
= GET_CODE (*locI
);
619 changed
|= replace_oldest_value_addr (locI
, INDEX_REG_CLASS
,
622 changed
|= replace_oldest_value_addr (locB
,
623 base_reg_class (mode
, as
, PLUS
,
638 return replace_oldest_value_mem (x
, insn
, vd
);
641 return replace_oldest_value_reg (loc
, cl
, insn
, vd
);
647 fmt
= GET_RTX_FORMAT (code
);
648 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
651 changed
|= replace_oldest_value_addr (&XEXP (x
, i
), cl
, mode
, as
,
653 else if (fmt
[i
] == 'E')
654 for (j
= XVECLEN (x
, i
) - 1; j
>= 0; j
--)
655 changed
|= replace_oldest_value_addr (&XVECEXP (x
, i
, j
), cl
,
662 /* Similar to replace_oldest_value_reg, but X contains a memory. */
665 replace_oldest_value_mem (rtx x
, rtx insn
, struct value_data
*vd
)
669 if (DEBUG_INSN_P (insn
))
672 cl
= base_reg_class (GET_MODE (x
), MEM_ADDR_SPACE (x
), MEM
, SCRATCH
);
674 return replace_oldest_value_addr (&XEXP (x
, 0), cl
,
675 GET_MODE (x
), MEM_ADDR_SPACE (x
),
679 /* Apply all queued updates for DEBUG_INSNs that change some reg to
683 apply_debug_insn_changes (struct value_data
*vd
, unsigned int regno
)
685 struct queued_debug_insn_change
*change
;
686 rtx last_insn
= vd
->e
[regno
].debug_insn_changes
->insn
;
688 for (change
= vd
->e
[regno
].debug_insn_changes
;
690 change
= change
->next
)
692 if (last_insn
!= change
->insn
)
694 apply_change_group ();
695 last_insn
= change
->insn
;
697 validate_change (change
->insn
, change
->loc
, change
->new_rtx
, 1);
699 apply_change_group ();
702 /* Called via for_each_rtx, for all used registers in a real
703 insn apply DEBUG_INSN changes that change registers to the
707 cprop_find_used_regs_1 (rtx
*loc
, void *data
)
711 struct value_data
*vd
= (struct value_data
*) data
;
712 if (vd
->e
[REGNO (*loc
)].debug_insn_changes
)
714 apply_debug_insn_changes (vd
, REGNO (*loc
));
715 free_debug_insn_changes (vd
, REGNO (*loc
));
721 /* Called via note_uses, for all used registers in a real insn
722 apply DEBUG_INSN changes that change registers to the used
726 cprop_find_used_regs (rtx
*loc
, void *vd
)
728 for_each_rtx (loc
, cprop_find_used_regs_1
, vd
);
731 /* Perform the forward copy propagation on basic block BB. */
734 copyprop_hardreg_forward_1 (basic_block bb
, struct value_data
*vd
)
736 bool anything_changed
= false;
739 for (insn
= BB_HEAD (bb
); ; insn
= NEXT_INSN (insn
))
741 int n_ops
, i
, alt
, predicated
;
742 bool is_asm
, any_replacements
;
745 bool replaced
[MAX_RECOG_OPERANDS
];
746 bool changed
= false;
748 if (!NONDEBUG_INSN_P (insn
))
750 if (DEBUG_INSN_P (insn
))
752 rtx loc
= INSN_VAR_LOCATION_LOC (insn
);
753 if (!VAR_LOC_UNKNOWN_P (loc
))
754 replace_oldest_value_addr (&INSN_VAR_LOCATION_LOC (insn
),
755 ALL_REGS
, GET_MODE (loc
),
756 ADDR_SPACE_GENERIC
, insn
, vd
);
759 if (insn
== BB_END (bb
))
765 set
= single_set (insn
);
767 if (! constrain_operands (1))
768 fatal_insn_not_found (insn
);
769 preprocess_constraints ();
770 alt
= which_alternative
;
771 n_ops
= recog_data
.n_operands
;
772 is_asm
= asm_noperands (PATTERN (insn
)) >= 0;
774 /* Simplify the code below by rewriting things to reflect
775 matching constraints. Also promote OP_OUT to OP_INOUT
776 in predicated instructions. */
778 predicated
= GET_CODE (PATTERN (insn
)) == COND_EXEC
;
779 for (i
= 0; i
< n_ops
; ++i
)
781 int matches
= recog_op_alt
[i
][alt
].matches
;
783 recog_op_alt
[i
][alt
].cl
= recog_op_alt
[matches
][alt
].cl
;
784 if (matches
>= 0 || recog_op_alt
[i
][alt
].matched
>= 0
785 || (predicated
&& recog_data
.operand_type
[i
] == OP_OUT
))
786 recog_data
.operand_type
[i
] = OP_INOUT
;
789 /* Apply changes to earlier DEBUG_INSNs if possible. */
790 if (vd
->n_debug_insn_changes
)
791 note_uses (&PATTERN (insn
), cprop_find_used_regs
, vd
);
793 /* For each earlyclobber operand, zap the value data. */
794 for (i
= 0; i
< n_ops
; i
++)
795 if (recog_op_alt
[i
][alt
].earlyclobber
)
796 kill_value (recog_data
.operand
[i
], vd
);
798 /* Within asms, a clobber cannot overlap inputs or outputs.
799 I wouldn't think this were true for regular insns, but
800 scan_rtx treats them like that... */
801 note_stores (PATTERN (insn
), kill_clobbered_value
, vd
);
803 /* Kill all auto-incremented values. */
804 /* ??? REG_INC is useless, since stack pushes aren't done that way. */
805 for_each_rtx (&PATTERN (insn
), kill_autoinc_value
, vd
);
807 /* Kill all early-clobbered operands. */
808 for (i
= 0; i
< n_ops
; i
++)
809 if (recog_op_alt
[i
][alt
].earlyclobber
)
810 kill_value (recog_data
.operand
[i
], vd
);
812 /* If we have dead sets in the insn, then we need to note these as we
814 for (link
= REG_NOTES (insn
); link
; link
= XEXP (link
, 1))
816 if (REG_NOTE_KIND (link
) == REG_UNUSED
)
818 kill_value (XEXP (link
, 0), vd
);
819 /* Furthermore, if the insn looked like a single-set,
820 but the dead store kills the source value of that
821 set, then we can no-longer use the plain move
822 special case below. */
824 && reg_overlap_mentioned_p (XEXP (link
, 0), SET_SRC (set
)))
829 /* Special-case plain move instructions, since we may well
830 be able to do the move from a different register class. */
831 if (set
&& REG_P (SET_SRC (set
)))
833 rtx src
= SET_SRC (set
);
834 unsigned int regno
= REGNO (src
);
835 enum machine_mode mode
= GET_MODE (src
);
839 /* If we are accessing SRC in some mode other that what we
840 set it in, make sure that the replacement is valid. */
841 if (mode
!= vd
->e
[regno
].mode
)
843 if (hard_regno_nregs
[regno
][mode
]
844 > hard_regno_nregs
[regno
][vd
->e
[regno
].mode
])
845 goto no_move_special_case
;
847 /* And likewise, if we are narrowing on big endian the transformation
849 if (hard_regno_nregs
[regno
][mode
]
850 < hard_regno_nregs
[regno
][vd
->e
[regno
].mode
]
851 && (GET_MODE_SIZE (vd
->e
[regno
].mode
) > UNITS_PER_WORD
852 ? WORDS_BIG_ENDIAN
: BYTES_BIG_ENDIAN
))
853 goto no_move_special_case
;
856 /* If the destination is also a register, try to find a source
857 register in the same class. */
858 if (REG_P (SET_DEST (set
)))
860 new_rtx
= find_oldest_value_reg (REGNO_REG_CLASS (regno
), src
, vd
);
861 if (new_rtx
&& validate_change (insn
, &SET_SRC (set
), new_rtx
, 0))
865 "insn %u: replaced reg %u with %u\n",
866 INSN_UID (insn
), regno
, REGNO (new_rtx
));
868 goto did_replacement
;
870 /* We need to re-extract as validate_change clobbers
873 if (! constrain_operands (1))
874 fatal_insn_not_found (insn
);
875 preprocess_constraints ();
878 /* Otherwise, try all valid registers and see if its valid. */
879 for (i
= vd
->e
[regno
].oldest_regno
; i
!= regno
;
880 i
= vd
->e
[i
].next_regno
)
882 new_rtx
= maybe_mode_change (vd
->e
[i
].mode
, vd
->e
[regno
].mode
,
884 if (new_rtx
!= NULL_RTX
)
886 if (validate_change (insn
, &SET_SRC (set
), new_rtx
, 0))
888 ORIGINAL_REGNO (new_rtx
) = ORIGINAL_REGNO (src
);
889 REG_ATTRS (new_rtx
) = REG_ATTRS (src
);
890 REG_POINTER (new_rtx
) = REG_POINTER (src
);
893 "insn %u: replaced reg %u with %u\n",
894 INSN_UID (insn
), regno
, REGNO (new_rtx
));
896 goto did_replacement
;
898 /* We need to re-extract as validate_change clobbers
901 if (! constrain_operands (1))
902 fatal_insn_not_found (insn
);
903 preprocess_constraints ();
907 no_move_special_case
:
909 any_replacements
= false;
911 /* For each input operand, replace a hard register with the
912 eldest live copy that's in an appropriate register class. */
913 for (i
= 0; i
< n_ops
; i
++)
917 /* Don't scan match_operand here, since we've no reg class
918 information to pass down. Any operands that we could
919 substitute in will be represented elsewhere. */
920 if (recog_data
.constraints
[i
][0] == '\0')
923 /* Don't replace in asms intentionally referencing hard regs. */
924 if (is_asm
&& REG_P (recog_data
.operand
[i
])
925 && (REGNO (recog_data
.operand
[i
])
926 == ORIGINAL_REGNO (recog_data
.operand
[i
])))
929 if (recog_data
.operand_type
[i
] == OP_IN
)
931 if (recog_op_alt
[i
][alt
].is_address
)
933 = replace_oldest_value_addr (recog_data
.operand_loc
[i
],
934 recog_op_alt
[i
][alt
].cl
,
935 VOIDmode
, ADDR_SPACE_GENERIC
,
937 else if (REG_P (recog_data
.operand
[i
]))
939 = replace_oldest_value_reg (recog_data
.operand_loc
[i
],
940 recog_op_alt
[i
][alt
].cl
,
942 else if (MEM_P (recog_data
.operand
[i
]))
943 replaced
[i
] = replace_oldest_value_mem (recog_data
.operand
[i
],
946 else if (MEM_P (recog_data
.operand
[i
]))
947 replaced
[i
] = replace_oldest_value_mem (recog_data
.operand
[i
],
950 /* If we performed any replacement, update match_dups. */
956 new_rtx
= *recog_data
.operand_loc
[i
];
957 recog_data
.operand
[i
] = new_rtx
;
958 for (j
= 0; j
< recog_data
.n_dups
; j
++)
959 if (recog_data
.dup_num
[j
] == i
)
960 validate_unshare_change (insn
, recog_data
.dup_loc
[j
], new_rtx
, 1);
962 any_replacements
= true;
966 if (any_replacements
)
968 if (! apply_change_group ())
970 for (i
= 0; i
< n_ops
; i
++)
973 rtx old
= *recog_data
.operand_loc
[i
];
974 recog_data
.operand
[i
] = old
;
979 "insn %u: reg replacements not verified\n",
989 anything_changed
= true;
991 /* If something changed, perhaps further changes to earlier
992 DEBUG_INSNs can be applied. */
993 if (vd
->n_debug_insn_changes
)
994 note_uses (&PATTERN (insn
), cprop_find_used_regs
, vd
);
997 /* Clobber call-clobbered registers. */
999 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; i
++)
1000 if (TEST_HARD_REG_BIT (regs_invalidated_by_call
, i
))
1001 kill_value_regno (i
, 1, vd
);
1003 /* Notice stores. */
1004 note_stores (PATTERN (insn
), kill_set_value
, vd
);
1006 /* Notice copies. */
1007 if (set
&& REG_P (SET_DEST (set
)) && REG_P (SET_SRC (set
)))
1008 copy_value (SET_DEST (set
), SET_SRC (set
), vd
);
1010 if (insn
== BB_END (bb
))
1014 return anything_changed
;
1017 /* Main entry point for the forward copy propagation optimization. */
1020 copyprop_hardreg_forward (void)
1022 struct value_data
*all_vd
;
1025 bool analyze_called
= false;
1027 all_vd
= XNEWVEC (struct value_data
, last_basic_block
);
1029 visited
= sbitmap_alloc (last_basic_block
);
1030 sbitmap_zero (visited
);
1032 if (MAY_HAVE_DEBUG_INSNS
)
1033 debug_insn_changes_pool
1034 = create_alloc_pool ("debug insn changes pool",
1035 sizeof (struct queued_debug_insn_change
), 256);
1039 SET_BIT (visited
, bb
->index
);
1041 /* If a block has a single predecessor, that we've already
1042 processed, begin with the value data that was live at
1043 the end of the predecessor block. */
1044 /* ??? Ought to use more intelligent queuing of blocks. */
1045 if (single_pred_p (bb
)
1046 && TEST_BIT (visited
, single_pred (bb
)->index
)
1047 && ! (single_pred_edge (bb
)->flags
& (EDGE_ABNORMAL_CALL
| EDGE_EH
)))
1049 all_vd
[bb
->index
] = all_vd
[single_pred (bb
)->index
];
1050 if (all_vd
[bb
->index
].n_debug_insn_changes
)
1054 for (regno
= 0; regno
< FIRST_PSEUDO_REGISTER
; regno
++)
1056 if (all_vd
[bb
->index
].e
[regno
].debug_insn_changes
)
1058 all_vd
[bb
->index
].e
[regno
].debug_insn_changes
= NULL
;
1059 if (--all_vd
[bb
->index
].n_debug_insn_changes
== 0)
1066 init_value_data (all_vd
+ bb
->index
);
1068 copyprop_hardreg_forward_1 (bb
, all_vd
+ bb
->index
);
1071 if (MAY_HAVE_DEBUG_INSNS
)
1074 if (TEST_BIT (visited
, bb
->index
)
1075 && all_vd
[bb
->index
].n_debug_insn_changes
)
1080 if (!analyze_called
)
1083 analyze_called
= true;
1085 live
= df_get_live_out (bb
);
1086 for (regno
= 0; regno
< FIRST_PSEUDO_REGISTER
; regno
++)
1087 if (all_vd
[bb
->index
].e
[regno
].debug_insn_changes
)
1089 if (REGNO_REG_SET_P (live
, regno
))
1090 apply_debug_insn_changes (all_vd
+ bb
->index
, regno
);
1091 if (all_vd
[bb
->index
].n_debug_insn_changes
== 0)
1096 free_alloc_pool (debug_insn_changes_pool
);
1099 sbitmap_free (visited
);
1104 /* Dump the value chain data to stderr. */
1107 debug_value_data (struct value_data
*vd
)
1112 CLEAR_HARD_REG_SET (set
);
1114 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
1115 if (vd
->e
[i
].oldest_regno
== i
)
1117 if (vd
->e
[i
].mode
== VOIDmode
)
1119 if (vd
->e
[i
].next_regno
!= INVALID_REGNUM
)
1120 fprintf (stderr
, "[%u] Bad next_regno for empty chain (%u)\n",
1121 i
, vd
->e
[i
].next_regno
);
1125 SET_HARD_REG_BIT (set
, i
);
1126 fprintf (stderr
, "[%u %s] ", i
, GET_MODE_NAME (vd
->e
[i
].mode
));
1128 for (j
= vd
->e
[i
].next_regno
;
1129 j
!= INVALID_REGNUM
;
1130 j
= vd
->e
[j
].next_regno
)
1132 if (TEST_HARD_REG_BIT (set
, j
))
1134 fprintf (stderr
, "[%u] Loop in regno chain\n", j
);
1138 if (vd
->e
[j
].oldest_regno
!= i
)
1140 fprintf (stderr
, "[%u] Bad oldest_regno (%u)\n",
1141 j
, vd
->e
[j
].oldest_regno
);
1144 SET_HARD_REG_BIT (set
, j
);
1145 fprintf (stderr
, "[%u %s] ", j
, GET_MODE_NAME (vd
->e
[j
].mode
));
1147 fputc ('\n', stderr
);
1150 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
1151 if (! TEST_HARD_REG_BIT (set
, i
)
1152 && (vd
->e
[i
].mode
!= VOIDmode
1153 || vd
->e
[i
].oldest_regno
!= i
1154 || vd
->e
[i
].next_regno
!= INVALID_REGNUM
))
1155 fprintf (stderr
, "[%u] Non-empty reg in chain (%s %u %i)\n",
1156 i
, GET_MODE_NAME (vd
->e
[i
].mode
), vd
->e
[i
].oldest_regno
,
1157 vd
->e
[i
].next_regno
);
1160 #ifdef ENABLE_CHECKING
1162 validate_value_data (struct value_data
*vd
)
1167 CLEAR_HARD_REG_SET (set
);
1169 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
1170 if (vd
->e
[i
].oldest_regno
== i
)
1172 if (vd
->e
[i
].mode
== VOIDmode
)
1174 if (vd
->e
[i
].next_regno
!= INVALID_REGNUM
)
1175 internal_error ("validate_value_data: [%u] Bad next_regno for empty chain (%u)",
1176 i
, vd
->e
[i
].next_regno
);
1180 SET_HARD_REG_BIT (set
, i
);
1182 for (j
= vd
->e
[i
].next_regno
;
1183 j
!= INVALID_REGNUM
;
1184 j
= vd
->e
[j
].next_regno
)
1186 if (TEST_HARD_REG_BIT (set
, j
))
1187 internal_error ("validate_value_data: Loop in regno chain (%u)",
1189 if (vd
->e
[j
].oldest_regno
!= i
)
1190 internal_error ("validate_value_data: [%u] Bad oldest_regno (%u)",
1191 j
, vd
->e
[j
].oldest_regno
);
1193 SET_HARD_REG_BIT (set
, j
);
1197 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
1198 if (! TEST_HARD_REG_BIT (set
, i
)
1199 && (vd
->e
[i
].mode
!= VOIDmode
1200 || vd
->e
[i
].oldest_regno
!= i
1201 || vd
->e
[i
].next_regno
!= INVALID_REGNUM
))
1202 internal_error ("validate_value_data: [%u] Non-empty reg in chain (%s %u %i)",
1203 i
, GET_MODE_NAME (vd
->e
[i
].mode
), vd
->e
[i
].oldest_regno
,
1204 vd
->e
[i
].next_regno
);
1209 gate_handle_cprop (void)
1211 return (optimize
> 0 && (flag_cprop_registers
));
1215 struct rtl_opt_pass pass_cprop_hardreg
=
1219 "cprop_hardreg", /* name */
1220 gate_handle_cprop
, /* gate */
1221 copyprop_hardreg_forward
, /* execute */
1224 0, /* static_pass_number */
1225 TV_CPROP_REGISTERS
, /* tv_id */
1226 0, /* properties_required */
1227 0, /* properties_provided */
1228 0, /* properties_destroyed */
1229 0, /* todo_flags_start */
1231 | TODO_verify_rtl_sharing
/* todo_flags_finish */