1 /* Copy propagation on hard registers for the GNU compiler.
2 Copyright (C) 2000-2015 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 3, 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 COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
22 #include "coretypes.h"
27 #include "insn-config.h"
29 #include "addresses.h"
33 #include "diagnostic-core.h"
34 #include "tree-pass.h"
38 /* The following code does forward propagation of hard register copies.
39 The object is to eliminate as many dependencies as possible, so that
40 we have the most scheduling freedom. As a side effect, we also clean
41 up some silly register allocation decisions made by reload. This
42 code may be obsoleted by a new register allocator. */
44 /* DEBUG_INSNs aren't changed right away, as doing so might extend the
45 lifetime of a register and get the DEBUG_INSN subsequently reset.
46 So they are queued instead, and updated only when the register is
47 used in some subsequent real insn before it is set. */
48 struct queued_debug_insn_change
50 struct queued_debug_insn_change
*next
;
56 /* For each register, we have a list of registers that contain the same
57 value. The OLDEST_REGNO field points to the head of the list, and
58 the NEXT_REGNO field runs through the list. The MODE field indicates
59 what mode the data is known to be in; this field is VOIDmode when the
60 register is not known to contain valid data. */
62 struct value_data_entry
65 unsigned int oldest_regno
;
66 unsigned int next_regno
;
67 struct queued_debug_insn_change
*debug_insn_changes
;
72 struct value_data_entry e
[FIRST_PSEUDO_REGISTER
];
73 unsigned int max_value_regs
;
74 unsigned int n_debug_insn_changes
;
77 static object_allocator
<queued_debug_insn_change
> queued_debug_insn_change_pool
78 ("debug insn changes pool");
80 static bool skip_debug_insn_p
;
82 static void kill_value_one_regno (unsigned, struct value_data
*);
83 static void kill_value_regno (unsigned, unsigned, struct value_data
*);
84 static void kill_value (const_rtx
, struct value_data
*);
85 static void set_value_regno (unsigned, machine_mode
, struct value_data
*);
86 static void init_value_data (struct value_data
*);
87 static void kill_clobbered_value (rtx
, const_rtx
, void *);
88 static void kill_set_value (rtx
, const_rtx
, void *);
89 static void copy_value (rtx
, rtx
, struct value_data
*);
90 static bool mode_change_ok (machine_mode
, machine_mode
,
92 static rtx
maybe_mode_change (machine_mode
, machine_mode
,
93 machine_mode
, unsigned int, unsigned int);
94 static rtx
find_oldest_value_reg (enum reg_class
, rtx
, struct value_data
*);
95 static bool replace_oldest_value_reg (rtx
*, enum reg_class
, rtx_insn
*,
97 static bool replace_oldest_value_addr (rtx
*, enum reg_class
,
98 machine_mode
, addr_space_t
,
99 rtx_insn
*, struct value_data
*);
100 static bool replace_oldest_value_mem (rtx
, rtx_insn
*, struct value_data
*);
101 static bool copyprop_hardreg_forward_1 (basic_block
, struct value_data
*);
102 extern void debug_value_data (struct value_data
*);
103 static void validate_value_data (struct value_data
*);
105 /* Free all queued updates for DEBUG_INSNs that change some reg to
109 free_debug_insn_changes (struct value_data
*vd
, unsigned int regno
)
111 struct queued_debug_insn_change
*cur
, *next
;
112 for (cur
= vd
->e
[regno
].debug_insn_changes
; cur
; cur
= next
)
115 --vd
->n_debug_insn_changes
;
116 queued_debug_insn_change_pool
.remove (cur
);
118 vd
->e
[regno
].debug_insn_changes
= NULL
;
121 /* Kill register REGNO. This involves removing it from any value
122 lists, and resetting the value mode to VOIDmode. This is only a
123 helper function; it does not handle any hard registers overlapping
127 kill_value_one_regno (unsigned int regno
, struct value_data
*vd
)
129 unsigned int i
, next
;
131 if (vd
->e
[regno
].oldest_regno
!= regno
)
133 for (i
= vd
->e
[regno
].oldest_regno
;
134 vd
->e
[i
].next_regno
!= regno
;
135 i
= vd
->e
[i
].next_regno
)
137 vd
->e
[i
].next_regno
= vd
->e
[regno
].next_regno
;
139 else if ((next
= vd
->e
[regno
].next_regno
) != INVALID_REGNUM
)
141 for (i
= next
; i
!= INVALID_REGNUM
; i
= vd
->e
[i
].next_regno
)
142 vd
->e
[i
].oldest_regno
= next
;
145 vd
->e
[regno
].mode
= VOIDmode
;
146 vd
->e
[regno
].oldest_regno
= regno
;
147 vd
->e
[regno
].next_regno
= INVALID_REGNUM
;
148 if (vd
->e
[regno
].debug_insn_changes
)
149 free_debug_insn_changes (vd
, regno
);
152 validate_value_data (vd
);
155 /* Kill the value in register REGNO for NREGS, and any other registers
156 whose values overlap. */
159 kill_value_regno (unsigned int regno
, unsigned int nregs
,
160 struct value_data
*vd
)
164 /* Kill the value we're told to kill. */
165 for (j
= 0; j
< nregs
; ++j
)
166 kill_value_one_regno (regno
+ j
, vd
);
168 /* Kill everything that overlapped what we're told to kill. */
169 if (regno
< vd
->max_value_regs
)
172 j
= regno
- vd
->max_value_regs
;
173 for (; j
< regno
; ++j
)
176 if (vd
->e
[j
].mode
== VOIDmode
)
178 n
= hard_regno_nregs
[j
][vd
->e
[j
].mode
];
180 for (i
= 0; i
< n
; ++i
)
181 kill_value_one_regno (j
+ i
, vd
);
185 /* Kill X. This is a convenience function wrapping kill_value_regno
186 so that we mind the mode the register is in. */
189 kill_value (const_rtx x
, struct value_data
*vd
)
191 if (GET_CODE (x
) == SUBREG
)
193 rtx tmp
= simplify_subreg (GET_MODE (x
), SUBREG_REG (x
),
194 GET_MODE (SUBREG_REG (x
)), SUBREG_BYTE (x
));
195 x
= tmp
? tmp
: SUBREG_REG (x
);
198 kill_value_regno (REGNO (x
), REG_NREGS (x
), vd
);
201 /* Remember that REGNO is valid in MODE. */
204 set_value_regno (unsigned int regno
, machine_mode mode
,
205 struct value_data
*vd
)
209 vd
->e
[regno
].mode
= mode
;
211 nregs
= hard_regno_nregs
[regno
][mode
];
212 if (nregs
> vd
->max_value_regs
)
213 vd
->max_value_regs
= nregs
;
216 /* Initialize VD such that there are no known relationships between regs. */
219 init_value_data (struct value_data
*vd
)
222 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
224 vd
->e
[i
].mode
= VOIDmode
;
225 vd
->e
[i
].oldest_regno
= i
;
226 vd
->e
[i
].next_regno
= INVALID_REGNUM
;
227 vd
->e
[i
].debug_insn_changes
= NULL
;
229 vd
->max_value_regs
= 0;
230 vd
->n_debug_insn_changes
= 0;
233 /* Called through note_stores. If X is clobbered, kill its value. */
236 kill_clobbered_value (rtx x
, const_rtx set
, void *data
)
238 struct value_data
*const vd
= (struct value_data
*) data
;
239 if (GET_CODE (set
) == CLOBBER
)
243 /* A structure passed as data to kill_set_value through note_stores. */
244 struct kill_set_value_data
246 struct value_data
*vd
;
250 /* Called through note_stores. If X is set, not clobbered, kill its
251 current value and install it as the root of its own value list. */
254 kill_set_value (rtx x
, const_rtx set
, void *data
)
256 struct kill_set_value_data
*ksvd
= (struct kill_set_value_data
*) data
;
257 if (rtx_equal_p (x
, ksvd
->ignore_set_reg
))
259 if (GET_CODE (set
) != CLOBBER
)
261 kill_value (x
, ksvd
->vd
);
263 set_value_regno (REGNO (x
), GET_MODE (x
), ksvd
->vd
);
267 /* Kill any register used in X as the base of an auto-increment expression,
268 and install that register as the root of its own value list. */
271 kill_autoinc_value (rtx_insn
*insn
, struct value_data
*vd
)
273 subrtx_iterator::array_type array
;
274 FOR_EACH_SUBRTX (iter
, array
, PATTERN (insn
), NONCONST
)
277 if (GET_RTX_CLASS (GET_CODE (x
)) == RTX_AUTOINC
)
281 set_value_regno (REGNO (x
), GET_MODE (x
), vd
);
282 iter
.skip_subrtxes ();
287 /* Assert that SRC has been copied to DEST. Adjust the data structures
288 to reflect that SRC contains an older copy of the shared value. */
291 copy_value (rtx dest
, rtx src
, struct value_data
*vd
)
293 unsigned int dr
= REGNO (dest
);
294 unsigned int sr
= REGNO (src
);
298 /* ??? At present, it's possible to see noop sets. It'd be nice if
299 this were cleaned up beforehand... */
303 /* Do not propagate copies to the stack pointer, as that can leave
304 memory accesses with no scheduling dependency on the stack update. */
305 if (dr
== STACK_POINTER_REGNUM
)
308 /* Likewise with the frame pointer, if we're using one. */
309 if (frame_pointer_needed
&& dr
== HARD_FRAME_POINTER_REGNUM
)
312 /* Do not propagate copies to fixed or global registers, patterns
313 can be relying to see particular fixed register or users can
314 expect the chosen global register in asm. */
315 if (fixed_regs
[dr
] || global_regs
[dr
])
318 /* If SRC and DEST overlap, don't record anything. */
319 dn
= REG_NREGS (dest
);
320 sn
= REG_NREGS (src
);
321 if ((dr
> sr
&& dr
< sr
+ sn
)
322 || (sr
> dr
&& sr
< dr
+ dn
))
325 /* If SRC had no assigned mode (i.e. we didn't know it was live)
326 assign it now and assume the value came from an input argument
328 if (vd
->e
[sr
].mode
== VOIDmode
)
329 set_value_regno (sr
, vd
->e
[dr
].mode
, vd
);
331 /* If we are narrowing the input to a smaller number of hard regs,
332 and it is in big endian, we are really extracting a high part.
333 Since we generally associate a low part of a value with the value itself,
334 we must not do the same for the high part.
335 Note we can still get low parts for the same mode combination through
336 a two-step copy involving differently sized hard regs.
337 Assume hard regs fr* are 32 bits each, while r* are 64 bits each:
338 (set (reg:DI r0) (reg:DI fr0))
339 (set (reg:SI fr2) (reg:SI r0))
340 loads the low part of (reg:DI fr0) - i.e. fr1 - into fr2, while:
341 (set (reg:SI fr2) (reg:SI fr0))
342 loads the high part of (reg:DI fr0) into fr2.
344 We can't properly represent the latter case in our tables, so don't
345 record anything then. */
346 else if (sn
< (unsigned int) hard_regno_nregs
[sr
][vd
->e
[sr
].mode
]
347 && (GET_MODE_SIZE (vd
->e
[sr
].mode
) > UNITS_PER_WORD
348 ? WORDS_BIG_ENDIAN
: BYTES_BIG_ENDIAN
))
351 /* If SRC had been assigned a mode narrower than the copy, we can't
352 link DEST into the chain, because not all of the pieces of the
353 copy came from oldest_regno. */
354 else if (sn
> (unsigned int) hard_regno_nregs
[sr
][vd
->e
[sr
].mode
])
357 /* Link DR at the end of the value chain used by SR. */
359 vd
->e
[dr
].oldest_regno
= vd
->e
[sr
].oldest_regno
;
361 for (i
= sr
; vd
->e
[i
].next_regno
!= INVALID_REGNUM
; i
= vd
->e
[i
].next_regno
)
363 vd
->e
[i
].next_regno
= dr
;
366 validate_value_data (vd
);
369 /* Return true if a mode change from ORIG to NEW is allowed for REGNO. */
372 mode_change_ok (machine_mode orig_mode
, machine_mode new_mode
,
373 unsigned int regno ATTRIBUTE_UNUSED
)
375 if (GET_MODE_SIZE (orig_mode
) < GET_MODE_SIZE (new_mode
))
378 #ifdef CANNOT_CHANGE_MODE_CLASS
379 return !REG_CANNOT_CHANGE_MODE_P (regno
, orig_mode
, new_mode
);
385 /* Register REGNO was originally set in ORIG_MODE. It - or a copy of it -
386 was copied in COPY_MODE to COPY_REGNO, and then COPY_REGNO was accessed
388 Return a NEW_MODE rtx for REGNO if that's OK, otherwise return NULL_RTX. */
391 maybe_mode_change (machine_mode orig_mode
, machine_mode copy_mode
,
392 machine_mode new_mode
, unsigned int regno
,
393 unsigned int copy_regno ATTRIBUTE_UNUSED
)
395 if (GET_MODE_SIZE (copy_mode
) < GET_MODE_SIZE (orig_mode
)
396 && GET_MODE_SIZE (copy_mode
) < GET_MODE_SIZE (new_mode
))
399 if (orig_mode
== new_mode
)
400 return gen_raw_REG (new_mode
, regno
);
401 else if (mode_change_ok (orig_mode
, new_mode
, regno
))
403 int copy_nregs
= hard_regno_nregs
[copy_regno
][copy_mode
];
404 int use_nregs
= hard_regno_nregs
[copy_regno
][new_mode
];
406 = GET_MODE_SIZE (copy_mode
) / copy_nregs
* (copy_nregs
- use_nregs
);
408 = GET_MODE_SIZE (orig_mode
) - GET_MODE_SIZE (new_mode
) - copy_offset
;
409 int byteoffset
= offset
% UNITS_PER_WORD
;
410 int wordoffset
= offset
- byteoffset
;
412 offset
= ((WORDS_BIG_ENDIAN
? wordoffset
: 0)
413 + (BYTES_BIG_ENDIAN
? byteoffset
: 0));
414 regno
+= subreg_regno_offset (regno
, orig_mode
, offset
, new_mode
);
415 if (HARD_REGNO_MODE_OK (regno
, new_mode
))
416 return gen_raw_REG (new_mode
, regno
);
421 /* Find the oldest copy of the value contained in REGNO that is in
422 register class CL and has mode MODE. If found, return an rtx
423 of that oldest register, otherwise return NULL. */
426 find_oldest_value_reg (enum reg_class cl
, rtx reg
, struct value_data
*vd
)
428 unsigned int regno
= REGNO (reg
);
429 machine_mode mode
= GET_MODE (reg
);
432 /* If we are accessing REG in some mode other that what we set it in,
433 make sure that the replacement is valid. In particular, consider
434 (set (reg:DI r11) (...))
435 (set (reg:SI r9) (reg:SI r11))
436 (set (reg:SI r10) (...))
437 (set (...) (reg:DI r9))
438 Replacing r9 with r11 is invalid. */
439 if (mode
!= vd
->e
[regno
].mode
)
441 if (hard_regno_nregs
[regno
][mode
]
442 > hard_regno_nregs
[regno
][vd
->e
[regno
].mode
])
446 for (i
= vd
->e
[regno
].oldest_regno
; i
!= regno
; i
= vd
->e
[i
].next_regno
)
448 machine_mode oldmode
= vd
->e
[i
].mode
;
451 if (!in_hard_reg_set_p (reg_class_contents
[cl
], mode
, i
))
454 new_rtx
= maybe_mode_change (oldmode
, vd
->e
[regno
].mode
, mode
, i
, regno
);
457 ORIGINAL_REGNO (new_rtx
) = ORIGINAL_REGNO (reg
);
458 REG_ATTRS (new_rtx
) = REG_ATTRS (reg
);
459 REG_POINTER (new_rtx
) = REG_POINTER (reg
);
467 /* If possible, replace the register at *LOC with the oldest register
468 in register class CL. Return true if successfully replaced. */
471 replace_oldest_value_reg (rtx
*loc
, enum reg_class cl
, rtx_insn
*insn
,
472 struct value_data
*vd
)
474 rtx new_rtx
= find_oldest_value_reg (cl
, *loc
, vd
);
475 if (new_rtx
&& (!DEBUG_INSN_P (insn
) || !skip_debug_insn_p
))
477 if (DEBUG_INSN_P (insn
))
479 struct queued_debug_insn_change
*change
;
482 fprintf (dump_file
, "debug_insn %u: queued replacing reg %u with %u\n",
483 INSN_UID (insn
), REGNO (*loc
), REGNO (new_rtx
));
485 change
= queued_debug_insn_change_pool
.allocate ();
486 change
->next
= vd
->e
[REGNO (new_rtx
)].debug_insn_changes
;
489 change
->new_rtx
= new_rtx
;
490 vd
->e
[REGNO (new_rtx
)].debug_insn_changes
= change
;
491 ++vd
->n_debug_insn_changes
;
495 fprintf (dump_file
, "insn %u: replaced reg %u with %u\n",
496 INSN_UID (insn
), REGNO (*loc
), REGNO (new_rtx
));
498 validate_change (insn
, loc
, new_rtx
, 1);
504 /* Similar to replace_oldest_value_reg, but *LOC contains an address.
505 Adapted from find_reloads_address_1. CL is INDEX_REG_CLASS or
506 BASE_REG_CLASS depending on how the register is being considered. */
509 replace_oldest_value_addr (rtx
*loc
, enum reg_class cl
,
510 machine_mode mode
, addr_space_t as
,
511 rtx_insn
*insn
, struct value_data
*vd
)
514 RTX_CODE code
= GET_CODE (x
);
517 bool changed
= false;
522 if (DEBUG_INSN_P (insn
))
526 rtx orig_op0
= XEXP (x
, 0);
527 rtx orig_op1
= XEXP (x
, 1);
528 RTX_CODE code0
= GET_CODE (orig_op0
);
529 RTX_CODE code1
= GET_CODE (orig_op1
);
534 enum rtx_code index_code
= SCRATCH
;
536 if (GET_CODE (op0
) == SUBREG
)
538 op0
= SUBREG_REG (op0
);
539 code0
= GET_CODE (op0
);
542 if (GET_CODE (op1
) == SUBREG
)
544 op1
= SUBREG_REG (op1
);
545 code1
= GET_CODE (op1
);
548 if (code0
== MULT
|| code0
== SIGN_EXTEND
|| code0
== TRUNCATE
549 || code0
== ZERO_EXTEND
|| code1
== MEM
)
553 index_code
= GET_CODE (*locI
);
555 else if (code1
== MULT
|| code1
== SIGN_EXTEND
|| code1
== TRUNCATE
556 || code1
== ZERO_EXTEND
|| code0
== MEM
)
560 index_code
= GET_CODE (*locI
);
562 else if (code0
== CONST_INT
|| code0
== CONST
563 || code0
== SYMBOL_REF
|| code0
== LABEL_REF
)
566 index_code
= GET_CODE (XEXP (x
, 0));
568 else if (code1
== CONST_INT
|| code1
== CONST
569 || code1
== SYMBOL_REF
|| code1
== LABEL_REF
)
572 index_code
= GET_CODE (XEXP (x
, 1));
574 else if (code0
== REG
&& code1
== REG
)
577 unsigned regno0
= REGNO (op0
), regno1
= REGNO (op1
);
579 if (REGNO_OK_FOR_INDEX_P (regno1
)
580 && regno_ok_for_base_p (regno0
, mode
, as
, PLUS
, REG
))
582 else if (REGNO_OK_FOR_INDEX_P (regno0
)
583 && regno_ok_for_base_p (regno1
, mode
, as
, PLUS
, REG
))
585 else if (regno_ok_for_base_p (regno0
, mode
, as
, PLUS
, REG
)
586 || REGNO_OK_FOR_INDEX_P (regno1
))
588 else if (regno_ok_for_base_p (regno1
, mode
, as
, PLUS
, REG
))
593 locI
= &XEXP (x
, index_op
);
594 locB
= &XEXP (x
, !index_op
);
595 index_code
= GET_CODE (*locI
);
597 else if (code0
== REG
)
601 index_code
= GET_CODE (*locI
);
603 else if (code1
== REG
)
607 index_code
= GET_CODE (*locI
);
611 changed
|= replace_oldest_value_addr (locI
, INDEX_REG_CLASS
,
614 changed
|= replace_oldest_value_addr (locB
,
615 base_reg_class (mode
, as
, PLUS
,
630 return replace_oldest_value_mem (x
, insn
, vd
);
633 return replace_oldest_value_reg (loc
, cl
, insn
, vd
);
639 fmt
= GET_RTX_FORMAT (code
);
640 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
643 changed
|= replace_oldest_value_addr (&XEXP (x
, i
), cl
, mode
, as
,
645 else if (fmt
[i
] == 'E')
646 for (j
= XVECLEN (x
, i
) - 1; j
>= 0; j
--)
647 changed
|= replace_oldest_value_addr (&XVECEXP (x
, i
, j
), cl
,
654 /* Similar to replace_oldest_value_reg, but X contains a memory. */
657 replace_oldest_value_mem (rtx x
, rtx_insn
*insn
, struct value_data
*vd
)
661 if (DEBUG_INSN_P (insn
))
664 cl
= base_reg_class (GET_MODE (x
), MEM_ADDR_SPACE (x
), MEM
, SCRATCH
);
666 return replace_oldest_value_addr (&XEXP (x
, 0), cl
,
667 GET_MODE (x
), MEM_ADDR_SPACE (x
),
671 /* Apply all queued updates for DEBUG_INSNs that change some reg to
675 apply_debug_insn_changes (struct value_data
*vd
, unsigned int regno
)
677 struct queued_debug_insn_change
*change
;
678 rtx_insn
*last_insn
= vd
->e
[regno
].debug_insn_changes
->insn
;
680 for (change
= vd
->e
[regno
].debug_insn_changes
;
682 change
= change
->next
)
684 if (last_insn
!= change
->insn
)
686 apply_change_group ();
687 last_insn
= change
->insn
;
689 validate_change (change
->insn
, change
->loc
, change
->new_rtx
, 1);
691 apply_change_group ();
694 /* Called via note_uses, for all used registers in a real insn
695 apply DEBUG_INSN changes that change registers to the used
699 cprop_find_used_regs (rtx
*loc
, void *data
)
701 struct value_data
*const vd
= (struct value_data
*) data
;
702 subrtx_iterator::array_type array
;
703 FOR_EACH_SUBRTX (iter
, array
, *loc
, NONCONST
)
708 unsigned int regno
= REGNO (x
);
709 if (vd
->e
[regno
].debug_insn_changes
)
711 apply_debug_insn_changes (vd
, regno
);
712 free_debug_insn_changes (vd
, regno
);
718 /* Apply clobbers of INSN in PATTERN and C_I_F_U to value_data VD. */
721 kill_clobbered_values (rtx_insn
*insn
, struct value_data
*vd
)
723 note_stores (PATTERN (insn
), kill_clobbered_value
, vd
);
729 for (exp
= CALL_INSN_FUNCTION_USAGE (insn
); exp
; exp
= XEXP (exp
, 1))
731 rtx x
= XEXP (exp
, 0);
732 if (GET_CODE (x
) == CLOBBER
)
733 kill_value (SET_DEST (x
), vd
);
738 /* Perform the forward copy propagation on basic block BB. */
741 copyprop_hardreg_forward_1 (basic_block bb
, struct value_data
*vd
)
743 bool anything_changed
= false;
746 for (insn
= BB_HEAD (bb
); ; insn
= NEXT_INSN (insn
))
748 int n_ops
, i
, predicated
;
749 bool is_asm
, any_replacements
;
752 bool replaced
[MAX_RECOG_OPERANDS
];
753 bool changed
= false;
754 struct kill_set_value_data ksvd
;
756 if (!NONDEBUG_INSN_P (insn
))
758 if (DEBUG_INSN_P (insn
))
760 rtx loc
= INSN_VAR_LOCATION_LOC (insn
);
761 if (!VAR_LOC_UNKNOWN_P (loc
))
762 replace_oldest_value_addr (&INSN_VAR_LOCATION_LOC (insn
),
763 ALL_REGS
, GET_MODE (loc
),
764 ADDR_SPACE_GENERIC
, insn
, vd
);
767 if (insn
== BB_END (bb
))
773 set
= single_set (insn
);
774 extract_constrain_insn (insn
);
775 preprocess_constraints (insn
);
776 const operand_alternative
*op_alt
= which_op_alt ();
777 n_ops
= recog_data
.n_operands
;
778 is_asm
= asm_noperands (PATTERN (insn
)) >= 0;
780 /* Simplify the code below by promoting OP_OUT to OP_INOUT
781 in predicated instructions. */
783 predicated
= GET_CODE (PATTERN (insn
)) == COND_EXEC
;
784 for (i
= 0; i
< n_ops
; ++i
)
786 int matches
= op_alt
[i
].matches
;
787 if (matches
>= 0 || op_alt
[i
].matched
>= 0
788 || (predicated
&& recog_data
.operand_type
[i
] == OP_OUT
))
789 recog_data
.operand_type
[i
] = OP_INOUT
;
792 /* Apply changes to earlier DEBUG_INSNs if possible. */
793 if (vd
->n_debug_insn_changes
)
794 note_uses (&PATTERN (insn
), cprop_find_used_regs
, vd
);
796 /* For each earlyclobber operand, zap the value data. */
797 for (i
= 0; i
< n_ops
; i
++)
798 if (op_alt
[i
].earlyclobber
)
799 kill_value (recog_data
.operand
[i
], vd
);
801 /* Within asms, a clobber cannot overlap inputs or outputs.
802 I wouldn't think this were true for regular insns, but
803 scan_rtx treats them like that... */
804 kill_clobbered_values (insn
, vd
);
806 /* Kill all auto-incremented values. */
807 /* ??? REG_INC is useless, since stack pushes aren't done that way. */
808 kill_autoinc_value (insn
, vd
);
810 /* Kill all early-clobbered operands. */
811 for (i
= 0; i
< n_ops
; i
++)
812 if (op_alt
[i
].earlyclobber
)
813 kill_value (recog_data
.operand
[i
], vd
);
815 /* If we have dead sets in the insn, then we need to note these as we
817 for (link
= REG_NOTES (insn
); link
; link
= XEXP (link
, 1))
819 if (REG_NOTE_KIND (link
) == REG_UNUSED
)
821 kill_value (XEXP (link
, 0), vd
);
822 /* Furthermore, if the insn looked like a single-set,
823 but the dead store kills the source value of that
824 set, then we can no-longer use the plain move
825 special case below. */
827 && reg_overlap_mentioned_p (XEXP (link
, 0), SET_SRC (set
)))
832 /* Special-case plain move instructions, since we may well
833 be able to do the move from a different register class. */
834 if (set
&& REG_P (SET_SRC (set
)))
836 rtx src
= SET_SRC (set
);
837 unsigned int regno
= REGNO (src
);
838 machine_mode mode
= GET_MODE (src
);
842 /* If we are accessing SRC in some mode other that what we
843 set it in, make sure that the replacement is valid. */
844 if (mode
!= vd
->e
[regno
].mode
)
846 if (hard_regno_nregs
[regno
][mode
]
847 > hard_regno_nregs
[regno
][vd
->e
[regno
].mode
])
848 goto no_move_special_case
;
850 /* And likewise, if we are narrowing on big endian the transformation
852 if (hard_regno_nregs
[regno
][mode
]
853 < hard_regno_nregs
[regno
][vd
->e
[regno
].mode
]
854 && (GET_MODE_SIZE (vd
->e
[regno
].mode
) > UNITS_PER_WORD
855 ? WORDS_BIG_ENDIAN
: BYTES_BIG_ENDIAN
))
856 goto no_move_special_case
;
859 /* If the destination is also a register, try to find a source
860 register in the same class. */
861 if (REG_P (SET_DEST (set
)))
863 new_rtx
= find_oldest_value_reg (REGNO_REG_CLASS (regno
), src
, vd
);
864 if (new_rtx
&& validate_change (insn
, &SET_SRC (set
), new_rtx
, 0))
868 "insn %u: replaced reg %u with %u\n",
869 INSN_UID (insn
), regno
, REGNO (new_rtx
));
871 goto did_replacement
;
873 /* We need to re-extract as validate_change clobbers
875 extract_constrain_insn (insn
);
876 preprocess_constraints (insn
);
879 /* Otherwise, try all valid registers and see if its valid. */
880 for (i
= vd
->e
[regno
].oldest_regno
; i
!= regno
;
881 i
= vd
->e
[i
].next_regno
)
883 new_rtx
= maybe_mode_change (vd
->e
[i
].mode
, vd
->e
[regno
].mode
,
885 if (new_rtx
!= NULL_RTX
)
887 if (validate_change (insn
, &SET_SRC (set
), new_rtx
, 0))
889 ORIGINAL_REGNO (new_rtx
) = ORIGINAL_REGNO (src
);
890 REG_ATTRS (new_rtx
) = REG_ATTRS (src
);
891 REG_POINTER (new_rtx
) = REG_POINTER (src
);
894 "insn %u: replaced reg %u with %u\n",
895 INSN_UID (insn
), regno
, REGNO (new_rtx
));
897 goto did_replacement
;
899 /* We need to re-extract as validate_change clobbers
901 extract_constrain_insn (insn
);
902 preprocess_constraints (insn
);
906 no_move_special_case
:
908 any_replacements
= false;
910 /* For each input operand, replace a hard register with the
911 eldest live copy that's in an appropriate register class. */
912 for (i
= 0; i
< n_ops
; i
++)
916 /* Don't scan match_operand here, since we've no reg class
917 information to pass down. Any operands that we could
918 substitute in will be represented elsewhere. */
919 if (recog_data
.constraints
[i
][0] == '\0')
922 /* Don't replace in asms intentionally referencing hard regs. */
923 if (is_asm
&& REG_P (recog_data
.operand
[i
])
924 && (REGNO (recog_data
.operand
[i
])
925 == ORIGINAL_REGNO (recog_data
.operand
[i
])))
928 if (recog_data
.operand_type
[i
] == OP_IN
)
930 if (op_alt
[i
].is_address
)
932 = replace_oldest_value_addr (recog_data
.operand_loc
[i
],
933 alternative_class (op_alt
, i
),
934 VOIDmode
, ADDR_SPACE_GENERIC
,
936 else if (REG_P (recog_data
.operand
[i
]))
938 = replace_oldest_value_reg (recog_data
.operand_loc
[i
],
939 alternative_class (op_alt
, i
),
941 else if (MEM_P (recog_data
.operand
[i
]))
942 replaced
[i
] = replace_oldest_value_mem (recog_data
.operand
[i
],
945 else if (MEM_P (recog_data
.operand
[i
]))
946 replaced
[i
] = replace_oldest_value_mem (recog_data
.operand
[i
],
949 /* If we performed any replacement, update match_dups. */
955 new_rtx
= *recog_data
.operand_loc
[i
];
956 recog_data
.operand
[i
] = new_rtx
;
957 for (j
= 0; j
< recog_data
.n_dups
; j
++)
958 if (recog_data
.dup_num
[j
] == i
)
959 validate_unshare_change (insn
, recog_data
.dup_loc
[j
], new_rtx
, 1);
961 any_replacements
= true;
965 if (any_replacements
)
967 if (! apply_change_group ())
969 for (i
= 0; i
< n_ops
; i
++)
972 rtx old
= *recog_data
.operand_loc
[i
];
973 recog_data
.operand
[i
] = old
;
978 "insn %u: reg replacements not verified\n",
988 anything_changed
= true;
990 /* If something changed, perhaps further changes to earlier
991 DEBUG_INSNs can be applied. */
992 if (vd
->n_debug_insn_changes
)
993 note_uses (&PATTERN (insn
), cprop_find_used_regs
, vd
);
997 ksvd
.ignore_set_reg
= NULL_RTX
;
999 /* Clobber call-clobbered registers. */
1002 unsigned int set_regno
= INVALID_REGNUM
;
1003 unsigned int set_nregs
= 0;
1006 HARD_REG_SET regs_invalidated_by_this_call
;
1008 for (exp
= CALL_INSN_FUNCTION_USAGE (insn
); exp
; exp
= XEXP (exp
, 1))
1010 rtx x
= XEXP (exp
, 0);
1011 if (GET_CODE (x
) == SET
)
1013 rtx dest
= SET_DEST (x
);
1014 kill_value (dest
, vd
);
1015 set_value_regno (REGNO (dest
), GET_MODE (dest
), vd
);
1016 copy_value (dest
, SET_SRC (x
), vd
);
1017 ksvd
.ignore_set_reg
= dest
;
1018 set_regno
= REGNO (dest
);
1019 set_nregs
= REG_NREGS (dest
);
1024 get_call_reg_set_usage (insn
,
1025 ®s_invalidated_by_this_call
,
1026 regs_invalidated_by_call
);
1027 for (regno
= 0; regno
< FIRST_PSEUDO_REGISTER
; regno
++)
1028 if ((TEST_HARD_REG_BIT (regs_invalidated_by_this_call
, regno
)
1029 || HARD_REGNO_CALL_PART_CLOBBERED (regno
, vd
->e
[regno
].mode
))
1030 && (regno
< set_regno
|| regno
>= set_regno
+ set_nregs
))
1031 kill_value_regno (regno
, 1, vd
);
1033 /* If SET was seen in CALL_INSN_FUNCTION_USAGE, and SET_SRC
1034 of the SET isn't in regs_invalidated_by_call hard reg set,
1035 but instead among CLOBBERs on the CALL_INSN, we could wrongly
1036 assume the value in it is still live. */
1037 if (ksvd
.ignore_set_reg
)
1038 kill_clobbered_values (insn
, vd
);
1042 && REG_P (SET_DEST (set
))
1043 && REG_P (SET_SRC (set
)));
1044 bool noop_p
= (copy_p
1045 && rtx_equal_p (SET_DEST (set
), SET_SRC (set
)));
1049 /* Notice stores. */
1050 note_stores (PATTERN (insn
), kill_set_value
, &ksvd
);
1052 /* Notice copies. */
1054 copy_value (SET_DEST (set
), SET_SRC (set
), vd
);
1057 if (insn
== BB_END (bb
))
1061 return anything_changed
;
1064 /* Dump the value chain data to stderr. */
1067 debug_value_data (struct value_data
*vd
)
1072 CLEAR_HARD_REG_SET (set
);
1074 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
1075 if (vd
->e
[i
].oldest_regno
== i
)
1077 if (vd
->e
[i
].mode
== VOIDmode
)
1079 if (vd
->e
[i
].next_regno
!= INVALID_REGNUM
)
1080 fprintf (stderr
, "[%u] Bad next_regno for empty chain (%u)\n",
1081 i
, vd
->e
[i
].next_regno
);
1085 SET_HARD_REG_BIT (set
, i
);
1086 fprintf (stderr
, "[%u %s] ", i
, GET_MODE_NAME (vd
->e
[i
].mode
));
1088 for (j
= vd
->e
[i
].next_regno
;
1089 j
!= INVALID_REGNUM
;
1090 j
= vd
->e
[j
].next_regno
)
1092 if (TEST_HARD_REG_BIT (set
, j
))
1094 fprintf (stderr
, "[%u] Loop in regno chain\n", j
);
1098 if (vd
->e
[j
].oldest_regno
!= i
)
1100 fprintf (stderr
, "[%u] Bad oldest_regno (%u)\n",
1101 j
, vd
->e
[j
].oldest_regno
);
1104 SET_HARD_REG_BIT (set
, j
);
1105 fprintf (stderr
, "[%u %s] ", j
, GET_MODE_NAME (vd
->e
[j
].mode
));
1107 fputc ('\n', stderr
);
1110 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
1111 if (! TEST_HARD_REG_BIT (set
, i
)
1112 && (vd
->e
[i
].mode
!= VOIDmode
1113 || vd
->e
[i
].oldest_regno
!= i
1114 || vd
->e
[i
].next_regno
!= INVALID_REGNUM
))
1115 fprintf (stderr
, "[%u] Non-empty reg in chain (%s %u %i)\n",
1116 i
, GET_MODE_NAME (vd
->e
[i
].mode
), vd
->e
[i
].oldest_regno
,
1117 vd
->e
[i
].next_regno
);
1120 /* Do copyprop_hardreg_forward_1 for a single basic block BB.
1121 DEBUG_INSN is skipped since we do not want to involve DF related
1122 staff as how it is handled in function pass_cprop_hardreg::execute.
1124 NOTE: Currently it is only used for shrink-wrap. Maybe extend it
1125 to handle DEBUG_INSN for other uses. */
1128 copyprop_hardreg_forward_bb_without_debug_insn (basic_block bb
)
1130 struct value_data
*vd
;
1131 vd
= XNEWVEC (struct value_data
, 1);
1132 init_value_data (vd
);
1134 skip_debug_insn_p
= true;
1135 copyprop_hardreg_forward_1 (bb
, vd
);
1137 skip_debug_insn_p
= false;
1141 validate_value_data (struct value_data
*vd
)
1146 CLEAR_HARD_REG_SET (set
);
1148 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
1149 if (vd
->e
[i
].oldest_regno
== i
)
1151 if (vd
->e
[i
].mode
== VOIDmode
)
1153 if (vd
->e
[i
].next_regno
!= INVALID_REGNUM
)
1154 internal_error ("validate_value_data: [%u] Bad next_regno for empty chain (%u)",
1155 i
, vd
->e
[i
].next_regno
);
1159 SET_HARD_REG_BIT (set
, i
);
1161 for (j
= vd
->e
[i
].next_regno
;
1162 j
!= INVALID_REGNUM
;
1163 j
= vd
->e
[j
].next_regno
)
1165 if (TEST_HARD_REG_BIT (set
, j
))
1166 internal_error ("validate_value_data: Loop in regno chain (%u)",
1168 if (vd
->e
[j
].oldest_regno
!= i
)
1169 internal_error ("validate_value_data: [%u] Bad oldest_regno (%u)",
1170 j
, vd
->e
[j
].oldest_regno
);
1172 SET_HARD_REG_BIT (set
, j
);
1176 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
1177 if (! TEST_HARD_REG_BIT (set
, i
)
1178 && (vd
->e
[i
].mode
!= VOIDmode
1179 || vd
->e
[i
].oldest_regno
!= i
1180 || vd
->e
[i
].next_regno
!= INVALID_REGNUM
))
1181 internal_error ("validate_value_data: [%u] Non-empty reg in chain (%s %u %i)",
1182 i
, GET_MODE_NAME (vd
->e
[i
].mode
), vd
->e
[i
].oldest_regno
,
1183 vd
->e
[i
].next_regno
);
1189 const pass_data pass_data_cprop_hardreg
=
1191 RTL_PASS
, /* type */
1192 "cprop_hardreg", /* name */
1193 OPTGROUP_NONE
, /* optinfo_flags */
1194 TV_CPROP_REGISTERS
, /* tv_id */
1195 0, /* properties_required */
1196 0, /* properties_provided */
1197 0, /* properties_destroyed */
1198 0, /* todo_flags_start */
1199 TODO_df_finish
, /* todo_flags_finish */
1202 class pass_cprop_hardreg
: public rtl_opt_pass
1205 pass_cprop_hardreg (gcc::context
*ctxt
)
1206 : rtl_opt_pass (pass_data_cprop_hardreg
, ctxt
)
1209 /* opt_pass methods: */
1210 virtual bool gate (function
*)
1212 return (optimize
> 0 && (flag_cprop_registers
));
1215 virtual unsigned int execute (function
*);
1217 }; // class pass_cprop_hardreg
1220 pass_cprop_hardreg::execute (function
*fun
)
1222 struct value_data
*all_vd
;
1225 bool analyze_called
= false;
1227 all_vd
= XNEWVEC (struct value_data
, last_basic_block_for_fn (fun
));
1229 visited
= sbitmap_alloc (last_basic_block_for_fn (fun
));
1230 bitmap_clear (visited
);
1232 FOR_EACH_BB_FN (bb
, fun
)
1234 bitmap_set_bit (visited
, bb
->index
);
1236 /* If a block has a single predecessor, that we've already
1237 processed, begin with the value data that was live at
1238 the end of the predecessor block. */
1239 /* ??? Ought to use more intelligent queuing of blocks. */
1240 if (single_pred_p (bb
)
1241 && bitmap_bit_p (visited
, single_pred (bb
)->index
)
1242 && ! (single_pred_edge (bb
)->flags
& (EDGE_ABNORMAL_CALL
| EDGE_EH
)))
1244 all_vd
[bb
->index
] = all_vd
[single_pred (bb
)->index
];
1245 if (all_vd
[bb
->index
].n_debug_insn_changes
)
1249 for (regno
= 0; regno
< FIRST_PSEUDO_REGISTER
; regno
++)
1251 if (all_vd
[bb
->index
].e
[regno
].debug_insn_changes
)
1253 all_vd
[bb
->index
].e
[regno
].debug_insn_changes
= NULL
;
1254 if (--all_vd
[bb
->index
].n_debug_insn_changes
== 0)
1261 init_value_data (all_vd
+ bb
->index
);
1263 copyprop_hardreg_forward_1 (bb
, all_vd
+ bb
->index
);
1266 if (MAY_HAVE_DEBUG_INSNS
)
1268 FOR_EACH_BB_FN (bb
, fun
)
1269 if (bitmap_bit_p (visited
, bb
->index
)
1270 && all_vd
[bb
->index
].n_debug_insn_changes
)
1275 if (!analyze_called
)
1278 analyze_called
= true;
1280 live
= df_get_live_out (bb
);
1281 for (regno
= 0; regno
< FIRST_PSEUDO_REGISTER
; regno
++)
1282 if (all_vd
[bb
->index
].e
[regno
].debug_insn_changes
)
1284 if (REGNO_REG_SET_P (live
, regno
))
1285 apply_debug_insn_changes (all_vd
+ bb
->index
, regno
);
1286 if (all_vd
[bb
->index
].n_debug_insn_changes
== 0)
1291 queued_debug_insn_change_pool
.release ();
1294 sbitmap_free (visited
);
1302 make_pass_cprop_hardreg (gcc::context
*ctxt
)
1304 return new pass_cprop_hardreg (ctxt
);