1 /* Copy propagation on hard registers for the GNU compiler.
2 Copyright (C) 2000-2017 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"
28 #include "insn-config.h"
32 #include "diagnostic-core.h"
33 #include "addresses.h"
34 #include "tree-pass.h"
39 /* The following code does forward propagation of hard register copies.
40 The object is to eliminate as many dependencies as possible, so that
41 we have the most scheduling freedom. As a side effect, we also clean
42 up some silly register allocation decisions made by reload. This
43 code may be obsoleted by a new register allocator. */
45 /* DEBUG_INSNs aren't changed right away, as doing so might extend the
46 lifetime of a register and get the DEBUG_INSN subsequently reset.
47 So they are queued instead, and updated only when the register is
48 used in some subsequent real insn before it is set. */
49 struct queued_debug_insn_change
51 struct queued_debug_insn_change
*next
;
57 /* For each register, we have a list of registers that contain the same
58 value. The OLDEST_REGNO field points to the head of the list, and
59 the NEXT_REGNO field runs through the list. The MODE field indicates
60 what mode the data is known to be in; this field is VOIDmode when the
61 register is not known to contain valid data. */
63 struct value_data_entry
66 unsigned int oldest_regno
;
67 unsigned int next_regno
;
68 struct queued_debug_insn_change
*debug_insn_changes
;
73 struct value_data_entry e
[FIRST_PSEUDO_REGISTER
];
74 unsigned int max_value_regs
;
75 unsigned int n_debug_insn_changes
;
78 static object_allocator
<queued_debug_insn_change
> queued_debug_insn_change_pool
79 ("debug insn changes pool");
81 static bool skip_debug_insn_p
;
83 static void kill_value_one_regno (unsigned, struct value_data
*);
84 static void kill_value_regno (unsigned, unsigned, struct value_data
*);
85 static void kill_value (const_rtx
, struct value_data
*);
86 static void set_value_regno (unsigned, machine_mode
, struct value_data
*);
87 static void init_value_data (struct value_data
*);
88 static void kill_clobbered_value (rtx
, const_rtx
, void *);
89 static void kill_set_value (rtx
, const_rtx
, void *);
90 static void copy_value (rtx
, rtx
, struct value_data
*);
91 static bool mode_change_ok (machine_mode
, machine_mode
,
93 static rtx
maybe_mode_change (machine_mode
, machine_mode
,
94 machine_mode
, unsigned int, unsigned int);
95 static rtx
find_oldest_value_reg (enum reg_class
, rtx
, struct value_data
*);
96 static bool replace_oldest_value_reg (rtx
*, enum reg_class
, rtx_insn
*,
98 static bool replace_oldest_value_addr (rtx
*, enum reg_class
,
99 machine_mode
, addr_space_t
,
100 rtx_insn
*, struct value_data
*);
101 static bool replace_oldest_value_mem (rtx
, rtx_insn
*, struct value_data
*);
102 static bool copyprop_hardreg_forward_1 (basic_block
, struct value_data
*);
103 extern void debug_value_data (struct value_data
*);
104 static void validate_value_data (struct value_data
*);
106 /* Free all queued updates for DEBUG_INSNs that change some reg to
110 free_debug_insn_changes (struct value_data
*vd
, unsigned int regno
)
112 struct queued_debug_insn_change
*cur
, *next
;
113 for (cur
= vd
->e
[regno
].debug_insn_changes
; cur
; cur
= next
)
116 --vd
->n_debug_insn_changes
;
117 queued_debug_insn_change_pool
.remove (cur
);
119 vd
->e
[regno
].debug_insn_changes
= NULL
;
122 /* Kill register REGNO. This involves removing it from any value
123 lists, and resetting the value mode to VOIDmode. This is only a
124 helper function; it does not handle any hard registers overlapping
128 kill_value_one_regno (unsigned int regno
, struct value_data
*vd
)
130 unsigned int i
, next
;
132 if (vd
->e
[regno
].oldest_regno
!= regno
)
134 for (i
= vd
->e
[regno
].oldest_regno
;
135 vd
->e
[i
].next_regno
!= regno
;
136 i
= vd
->e
[i
].next_regno
)
138 vd
->e
[i
].next_regno
= vd
->e
[regno
].next_regno
;
140 else if ((next
= vd
->e
[regno
].next_regno
) != INVALID_REGNUM
)
142 for (i
= next
; i
!= INVALID_REGNUM
; i
= vd
->e
[i
].next_regno
)
143 vd
->e
[i
].oldest_regno
= next
;
146 vd
->e
[regno
].mode
= VOIDmode
;
147 vd
->e
[regno
].oldest_regno
= regno
;
148 vd
->e
[regno
].next_regno
= INVALID_REGNUM
;
149 if (vd
->e
[regno
].debug_insn_changes
)
150 free_debug_insn_changes (vd
, regno
);
153 validate_value_data (vd
);
156 /* Kill the value in register REGNO for NREGS, and any other registers
157 whose values overlap. */
160 kill_value_regno (unsigned int regno
, unsigned int nregs
,
161 struct value_data
*vd
)
165 /* Kill the value we're told to kill. */
166 for (j
= 0; j
< nregs
; ++j
)
167 kill_value_one_regno (regno
+ j
, vd
);
169 /* Kill everything that overlapped what we're told to kill. */
170 if (regno
< vd
->max_value_regs
)
173 j
= regno
- vd
->max_value_regs
;
174 for (; j
< regno
; ++j
)
177 if (vd
->e
[j
].mode
== VOIDmode
)
179 n
= hard_regno_nregs
[j
][vd
->e
[j
].mode
];
181 for (i
= 0; i
< n
; ++i
)
182 kill_value_one_regno (j
+ i
, vd
);
186 /* Kill X. This is a convenience function wrapping kill_value_regno
187 so that we mind the mode the register is in. */
190 kill_value (const_rtx x
, struct value_data
*vd
)
192 if (GET_CODE (x
) == SUBREG
)
194 rtx tmp
= simplify_subreg (GET_MODE (x
), SUBREG_REG (x
),
195 GET_MODE (SUBREG_REG (x
)), SUBREG_BYTE (x
));
196 x
= tmp
? tmp
: SUBREG_REG (x
);
199 kill_value_regno (REGNO (x
), REG_NREGS (x
), vd
);
202 /* Remember that REGNO is valid in MODE. */
205 set_value_regno (unsigned int regno
, machine_mode mode
,
206 struct value_data
*vd
)
210 vd
->e
[regno
].mode
= mode
;
212 nregs
= hard_regno_nregs
[regno
][mode
];
213 if (nregs
> vd
->max_value_regs
)
214 vd
->max_value_regs
= nregs
;
217 /* Initialize VD such that there are no known relationships between regs. */
220 init_value_data (struct value_data
*vd
)
223 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
225 vd
->e
[i
].mode
= VOIDmode
;
226 vd
->e
[i
].oldest_regno
= i
;
227 vd
->e
[i
].next_regno
= INVALID_REGNUM
;
228 vd
->e
[i
].debug_insn_changes
= NULL
;
230 vd
->max_value_regs
= 0;
231 vd
->n_debug_insn_changes
= 0;
234 /* Called through note_stores. If X is clobbered, kill its value. */
237 kill_clobbered_value (rtx x
, const_rtx set
, void *data
)
239 struct value_data
*const vd
= (struct value_data
*) data
;
240 if (GET_CODE (set
) == CLOBBER
)
244 /* A structure passed as data to kill_set_value through note_stores. */
245 struct kill_set_value_data
247 struct value_data
*vd
;
251 /* Called through note_stores. If X is set, not clobbered, kill its
252 current value and install it as the root of its own value list. */
255 kill_set_value (rtx x
, const_rtx set
, void *data
)
257 struct kill_set_value_data
*ksvd
= (struct kill_set_value_data
*) data
;
258 if (rtx_equal_p (x
, ksvd
->ignore_set_reg
))
260 if (GET_CODE (set
) != CLOBBER
)
262 kill_value (x
, ksvd
->vd
);
264 set_value_regno (REGNO (x
), GET_MODE (x
), ksvd
->vd
);
268 /* Kill any register used in X as the base of an auto-increment expression,
269 and install that register as the root of its own value list. */
272 kill_autoinc_value (rtx_insn
*insn
, struct value_data
*vd
)
274 subrtx_iterator::array_type array
;
275 FOR_EACH_SUBRTX (iter
, array
, PATTERN (insn
), NONCONST
)
278 if (GET_RTX_CLASS (GET_CODE (x
)) == RTX_AUTOINC
)
282 set_value_regno (REGNO (x
), GET_MODE (x
), vd
);
283 iter
.skip_subrtxes ();
288 /* Assert that SRC has been copied to DEST. Adjust the data structures
289 to reflect that SRC contains an older copy of the shared value. */
292 copy_value (rtx dest
, rtx src
, struct value_data
*vd
)
294 unsigned int dr
= REGNO (dest
);
295 unsigned int sr
= REGNO (src
);
299 /* ??? At present, it's possible to see noop sets. It'd be nice if
300 this were cleaned up beforehand... */
304 /* Do not propagate copies to the stack pointer, as that can leave
305 memory accesses with no scheduling dependency on the stack update. */
306 if (dr
== STACK_POINTER_REGNUM
)
309 /* Likewise with the frame pointer, if we're using one. */
310 if (frame_pointer_needed
&& dr
== HARD_FRAME_POINTER_REGNUM
)
313 /* Do not propagate copies to fixed or global registers, patterns
314 can be relying to see particular fixed register or users can
315 expect the chosen global register in asm. */
316 if (fixed_regs
[dr
] || global_regs
[dr
])
319 /* If SRC and DEST overlap, don't record anything. */
320 dn
= REG_NREGS (dest
);
321 sn
= REG_NREGS (src
);
322 if ((dr
> sr
&& dr
< sr
+ sn
)
323 || (sr
> dr
&& sr
< dr
+ dn
))
326 /* If SRC had no assigned mode (i.e. we didn't know it was live)
327 assign it now and assume the value came from an input argument
329 if (vd
->e
[sr
].mode
== VOIDmode
)
330 set_value_regno (sr
, vd
->e
[dr
].mode
, vd
);
332 /* If we are narrowing the input to a smaller number of hard regs,
333 and it is in big endian, we are really extracting a high part.
334 Since we generally associate a low part of a value with the value itself,
335 we must not do the same for the high part.
336 Note we can still get low parts for the same mode combination through
337 a two-step copy involving differently sized hard regs.
338 Assume hard regs fr* are 32 bits each, while r* are 64 bits each:
339 (set (reg:DI r0) (reg:DI fr0))
340 (set (reg:SI fr2) (reg:SI r0))
341 loads the low part of (reg:DI fr0) - i.e. fr1 - into fr2, while:
342 (set (reg:SI fr2) (reg:SI fr0))
343 loads the high part of (reg:DI fr0) into fr2.
345 We can't properly represent the latter case in our tables, so don't
346 record anything then. */
347 else if (sn
< (unsigned int) hard_regno_nregs
[sr
][vd
->e
[sr
].mode
]
348 && (GET_MODE_SIZE (vd
->e
[sr
].mode
) > UNITS_PER_WORD
349 ? WORDS_BIG_ENDIAN
: BYTES_BIG_ENDIAN
))
352 /* If SRC had been assigned a mode narrower than the copy, we can't
353 link DEST into the chain, because not all of the pieces of the
354 copy came from oldest_regno. */
355 else if (sn
> (unsigned int) hard_regno_nregs
[sr
][vd
->e
[sr
].mode
])
358 /* Link DR at the end of the value chain used by SR. */
360 vd
->e
[dr
].oldest_regno
= vd
->e
[sr
].oldest_regno
;
362 for (i
= sr
; vd
->e
[i
].next_regno
!= INVALID_REGNUM
; i
= vd
->e
[i
].next_regno
)
364 vd
->e
[i
].next_regno
= dr
;
367 validate_value_data (vd
);
370 /* Return true if a mode change from ORIG to NEW is allowed for REGNO. */
373 mode_change_ok (machine_mode orig_mode
, machine_mode new_mode
,
374 unsigned int regno ATTRIBUTE_UNUSED
)
376 if (partial_subreg_p (orig_mode
, new_mode
))
379 #ifdef CANNOT_CHANGE_MODE_CLASS
380 return !REG_CANNOT_CHANGE_MODE_P (regno
, orig_mode
, new_mode
);
386 /* Register REGNO was originally set in ORIG_MODE. It - or a copy of it -
387 was copied in COPY_MODE to COPY_REGNO, and then COPY_REGNO was accessed
389 Return a NEW_MODE rtx for REGNO if that's OK, otherwise return NULL_RTX. */
392 maybe_mode_change (machine_mode orig_mode
, machine_mode copy_mode
,
393 machine_mode new_mode
, unsigned int regno
,
394 unsigned int copy_regno ATTRIBUTE_UNUSED
)
396 if (partial_subreg_p (copy_mode
, orig_mode
)
397 && partial_subreg_p (copy_mode
, new_mode
))
400 /* Avoid creating multiple copies of the stack pointer. Some ports
401 assume there is one and only one stack pointer.
403 It's unclear if we need to do the same for other special registers. */
404 if (regno
== STACK_POINTER_REGNUM
)
407 if (orig_mode
== new_mode
)
408 return gen_raw_REG (new_mode
, regno
);
409 else if (mode_change_ok (orig_mode
, new_mode
, regno
))
411 int copy_nregs
= hard_regno_nregs
[copy_regno
][copy_mode
];
412 int use_nregs
= hard_regno_nregs
[copy_regno
][new_mode
];
414 = GET_MODE_SIZE (copy_mode
) / copy_nregs
* (copy_nregs
- use_nregs
);
416 = GET_MODE_SIZE (orig_mode
) - GET_MODE_SIZE (new_mode
) - copy_offset
;
417 int byteoffset
= offset
% UNITS_PER_WORD
;
418 int wordoffset
= offset
- byteoffset
;
420 offset
= ((WORDS_BIG_ENDIAN
? wordoffset
: 0)
421 + (BYTES_BIG_ENDIAN
? byteoffset
: 0));
422 regno
+= subreg_regno_offset (regno
, orig_mode
, offset
, new_mode
);
423 if (targetm
.hard_regno_mode_ok (regno
, new_mode
))
424 return gen_raw_REG (new_mode
, regno
);
429 /* Find the oldest copy of the value contained in REGNO that is in
430 register class CL and has mode MODE. If found, return an rtx
431 of that oldest register, otherwise return NULL. */
434 find_oldest_value_reg (enum reg_class cl
, rtx reg
, struct value_data
*vd
)
436 unsigned int regno
= REGNO (reg
);
437 machine_mode mode
= GET_MODE (reg
);
440 /* If we are accessing REG in some mode other that what we set it in,
441 make sure that the replacement is valid. In particular, consider
442 (set (reg:DI r11) (...))
443 (set (reg:SI r9) (reg:SI r11))
444 (set (reg:SI r10) (...))
445 (set (...) (reg:DI r9))
446 Replacing r9 with r11 is invalid. */
447 if (mode
!= vd
->e
[regno
].mode
)
449 if (hard_regno_nregs
[regno
][mode
]
450 > hard_regno_nregs
[regno
][vd
->e
[regno
].mode
])
454 for (i
= vd
->e
[regno
].oldest_regno
; i
!= regno
; i
= vd
->e
[i
].next_regno
)
456 machine_mode oldmode
= vd
->e
[i
].mode
;
459 if (!in_hard_reg_set_p (reg_class_contents
[cl
], mode
, i
))
462 new_rtx
= maybe_mode_change (oldmode
, vd
->e
[regno
].mode
, mode
, i
, regno
);
465 ORIGINAL_REGNO (new_rtx
) = ORIGINAL_REGNO (reg
);
466 REG_ATTRS (new_rtx
) = REG_ATTRS (reg
);
467 REG_POINTER (new_rtx
) = REG_POINTER (reg
);
475 /* If possible, replace the register at *LOC with the oldest register
476 in register class CL. Return true if successfully replaced. */
479 replace_oldest_value_reg (rtx
*loc
, enum reg_class cl
, rtx_insn
*insn
,
480 struct value_data
*vd
)
482 rtx new_rtx
= find_oldest_value_reg (cl
, *loc
, vd
);
483 if (new_rtx
&& (!DEBUG_INSN_P (insn
) || !skip_debug_insn_p
))
485 if (DEBUG_INSN_P (insn
))
487 struct queued_debug_insn_change
*change
;
490 fprintf (dump_file
, "debug_insn %u: queued replacing reg %u with %u\n",
491 INSN_UID (insn
), REGNO (*loc
), REGNO (new_rtx
));
493 change
= queued_debug_insn_change_pool
.allocate ();
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 machine_mode mode
, addr_space_t as
,
519 rtx_insn
*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
*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_insn
*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 note_uses, for all used registers in a real insn
703 apply DEBUG_INSN changes that change registers to the used
707 cprop_find_used_regs (rtx
*loc
, void *data
)
709 struct value_data
*const vd
= (struct value_data
*) data
;
710 subrtx_iterator::array_type array
;
711 FOR_EACH_SUBRTX (iter
, array
, *loc
, NONCONST
)
716 unsigned int regno
= REGNO (x
);
717 if (vd
->e
[regno
].debug_insn_changes
)
719 apply_debug_insn_changes (vd
, regno
);
720 free_debug_insn_changes (vd
, regno
);
726 /* Apply clobbers of INSN in PATTERN and C_I_F_U to value_data VD. */
729 kill_clobbered_values (rtx_insn
*insn
, struct value_data
*vd
)
731 note_stores (PATTERN (insn
), kill_clobbered_value
, vd
);
737 for (exp
= CALL_INSN_FUNCTION_USAGE (insn
); exp
; exp
= XEXP (exp
, 1))
739 rtx x
= XEXP (exp
, 0);
740 if (GET_CODE (x
) == CLOBBER
)
741 kill_value (SET_DEST (x
), vd
);
746 /* Perform the forward copy propagation on basic block BB. */
749 copyprop_hardreg_forward_1 (basic_block bb
, struct value_data
*vd
)
751 bool anything_changed
= false;
752 rtx_insn
*insn
, *next
;
754 for (insn
= BB_HEAD (bb
); ; insn
= next
)
756 int n_ops
, i
, predicated
;
757 bool is_asm
, any_replacements
;
760 bool replaced
[MAX_RECOG_OPERANDS
];
761 bool changed
= false;
762 struct kill_set_value_data ksvd
;
764 next
= NEXT_INSN (insn
);
765 if (!NONDEBUG_INSN_P (insn
))
767 if (DEBUG_INSN_P (insn
))
769 rtx loc
= INSN_VAR_LOCATION_LOC (insn
);
770 if (!VAR_LOC_UNKNOWN_P (loc
))
771 replace_oldest_value_addr (&INSN_VAR_LOCATION_LOC (insn
),
772 ALL_REGS
, GET_MODE (loc
),
773 ADDR_SPACE_GENERIC
, insn
, vd
);
776 if (insn
== BB_END (bb
))
782 set
= single_set (insn
);
784 /* Detect noop sets and remove them before processing side effects. */
785 if (set
&& REG_P (SET_DEST (set
)) && REG_P (SET_SRC (set
)))
787 unsigned int regno
= REGNO (SET_SRC (set
));
788 rtx r1
= find_oldest_value_reg (REGNO_REG_CLASS (regno
),
790 rtx r2
= find_oldest_value_reg (REGNO_REG_CLASS (regno
),
792 if (rtx_equal_p (r1
? r1
: SET_DEST (set
), r2
? r2
: SET_SRC (set
)))
794 bool last
= insn
== BB_END (bb
);
802 extract_constrain_insn (insn
);
803 preprocess_constraints (insn
);
804 const operand_alternative
*op_alt
= which_op_alt ();
805 n_ops
= recog_data
.n_operands
;
806 is_asm
= asm_noperands (PATTERN (insn
)) >= 0;
808 /* Simplify the code below by promoting OP_OUT to OP_INOUT
809 in predicated instructions. */
811 predicated
= GET_CODE (PATTERN (insn
)) == COND_EXEC
;
812 for (i
= 0; i
< n_ops
; ++i
)
814 int matches
= op_alt
[i
].matches
;
815 if (matches
>= 0 || op_alt
[i
].matched
>= 0
816 || (predicated
&& recog_data
.operand_type
[i
] == OP_OUT
))
817 recog_data
.operand_type
[i
] = OP_INOUT
;
820 /* Apply changes to earlier DEBUG_INSNs if possible. */
821 if (vd
->n_debug_insn_changes
)
822 note_uses (&PATTERN (insn
), cprop_find_used_regs
, vd
);
824 /* For each earlyclobber operand, zap the value data. */
825 for (i
= 0; i
< n_ops
; i
++)
826 if (op_alt
[i
].earlyclobber
)
827 kill_value (recog_data
.operand
[i
], vd
);
829 /* Within asms, a clobber cannot overlap inputs or outputs.
830 I wouldn't think this were true for regular insns, but
831 scan_rtx treats them like that... */
832 kill_clobbered_values (insn
, vd
);
834 /* Kill all auto-incremented values. */
835 /* ??? REG_INC is useless, since stack pushes aren't done that way. */
836 kill_autoinc_value (insn
, vd
);
838 /* Kill all early-clobbered operands. */
839 for (i
= 0; i
< n_ops
; i
++)
840 if (op_alt
[i
].earlyclobber
)
841 kill_value (recog_data
.operand
[i
], vd
);
843 /* If we have dead sets in the insn, then we need to note these as we
845 for (link
= REG_NOTES (insn
); link
; link
= XEXP (link
, 1))
847 if (REG_NOTE_KIND (link
) == REG_UNUSED
)
849 kill_value (XEXP (link
, 0), vd
);
850 /* Furthermore, if the insn looked like a single-set,
851 but the dead store kills the source value of that
852 set, then we can no-longer use the plain move
853 special case below. */
855 && reg_overlap_mentioned_p (XEXP (link
, 0), SET_SRC (set
)))
860 /* Special-case plain move instructions, since we may well
861 be able to do the move from a different register class. */
862 if (set
&& REG_P (SET_SRC (set
)))
864 rtx src
= SET_SRC (set
);
865 unsigned int regno
= REGNO (src
);
866 machine_mode mode
= GET_MODE (src
);
870 /* If we are accessing SRC in some mode other that what we
871 set it in, make sure that the replacement is valid. */
872 if (mode
!= vd
->e
[regno
].mode
)
874 if (hard_regno_nregs
[regno
][mode
]
875 > hard_regno_nregs
[regno
][vd
->e
[regno
].mode
])
876 goto no_move_special_case
;
878 /* And likewise, if we are narrowing on big endian the transformation
880 if (hard_regno_nregs
[regno
][mode
]
881 < hard_regno_nregs
[regno
][vd
->e
[regno
].mode
]
882 && (GET_MODE_SIZE (vd
->e
[regno
].mode
) > UNITS_PER_WORD
883 ? WORDS_BIG_ENDIAN
: BYTES_BIG_ENDIAN
))
884 goto no_move_special_case
;
887 /* If the destination is also a register, try to find a source
888 register in the same class. */
889 if (REG_P (SET_DEST (set
)))
891 new_rtx
= find_oldest_value_reg (REGNO_REG_CLASS (regno
),
894 if (new_rtx
&& validate_change (insn
, &SET_SRC (set
), new_rtx
, 0))
898 "insn %u: replaced reg %u with %u\n",
899 INSN_UID (insn
), regno
, REGNO (new_rtx
));
901 goto did_replacement
;
903 /* We need to re-extract as validate_change clobbers
905 extract_constrain_insn (insn
);
906 preprocess_constraints (insn
);
909 /* Otherwise, try all valid registers and see if its valid. */
910 for (i
= vd
->e
[regno
].oldest_regno
; i
!= regno
;
911 i
= vd
->e
[i
].next_regno
)
913 new_rtx
= maybe_mode_change (vd
->e
[i
].mode
, vd
->e
[regno
].mode
,
915 if (new_rtx
!= NULL_RTX
)
917 if (validate_change (insn
, &SET_SRC (set
), new_rtx
, 0))
919 ORIGINAL_REGNO (new_rtx
) = ORIGINAL_REGNO (src
);
920 REG_ATTRS (new_rtx
) = REG_ATTRS (src
);
921 REG_POINTER (new_rtx
) = REG_POINTER (src
);
924 "insn %u: replaced reg %u with %u\n",
925 INSN_UID (insn
), regno
, REGNO (new_rtx
));
927 goto did_replacement
;
929 /* We need to re-extract as validate_change clobbers
931 extract_constrain_insn (insn
);
932 preprocess_constraints (insn
);
936 no_move_special_case
:
938 any_replacements
= false;
940 /* For each input operand, replace a hard register with the
941 eldest live copy that's in an appropriate register class. */
942 for (i
= 0; i
< n_ops
; i
++)
946 /* Don't scan match_operand here, since we've no reg class
947 information to pass down. Any operands that we could
948 substitute in will be represented elsewhere. */
949 if (recog_data
.constraints
[i
][0] == '\0')
952 /* Don't replace in asms intentionally referencing hard regs. */
953 if (is_asm
&& REG_P (recog_data
.operand
[i
])
954 && (REGNO (recog_data
.operand
[i
])
955 == ORIGINAL_REGNO (recog_data
.operand
[i
])))
958 if (recog_data
.operand_type
[i
] == OP_IN
)
960 if (op_alt
[i
].is_address
)
962 = replace_oldest_value_addr (recog_data
.operand_loc
[i
],
963 alternative_class (op_alt
, i
),
964 VOIDmode
, ADDR_SPACE_GENERIC
,
966 else if (REG_P (recog_data
.operand
[i
]))
968 = replace_oldest_value_reg (recog_data
.operand_loc
[i
],
969 alternative_class (op_alt
, i
),
971 else if (MEM_P (recog_data
.operand
[i
]))
972 replaced
[i
] = replace_oldest_value_mem (recog_data
.operand
[i
],
975 else if (MEM_P (recog_data
.operand
[i
]))
976 replaced
[i
] = replace_oldest_value_mem (recog_data
.operand
[i
],
979 /* If we performed any replacement, update match_dups. */
985 new_rtx
= *recog_data
.operand_loc
[i
];
986 recog_data
.operand
[i
] = new_rtx
;
987 for (j
= 0; j
< recog_data
.n_dups
; j
++)
988 if (recog_data
.dup_num
[j
] == i
)
989 validate_unshare_change (insn
, recog_data
.dup_loc
[j
], new_rtx
, 1);
991 any_replacements
= true;
995 if (any_replacements
)
997 if (! apply_change_group ())
999 for (i
= 0; i
< n_ops
; i
++)
1002 rtx old
= *recog_data
.operand_loc
[i
];
1003 recog_data
.operand
[i
] = old
;
1008 "insn %u: reg replacements not verified\n",
1018 anything_changed
= true;
1020 /* If something changed, perhaps further changes to earlier
1021 DEBUG_INSNs can be applied. */
1022 if (vd
->n_debug_insn_changes
)
1023 note_uses (&PATTERN (insn
), cprop_find_used_regs
, vd
);
1027 ksvd
.ignore_set_reg
= NULL_RTX
;
1029 /* Clobber call-clobbered registers. */
1032 unsigned int set_regno
= INVALID_REGNUM
;
1033 unsigned int set_nregs
= 0;
1036 HARD_REG_SET regs_invalidated_by_this_call
;
1038 for (exp
= CALL_INSN_FUNCTION_USAGE (insn
); exp
; exp
= XEXP (exp
, 1))
1040 rtx x
= XEXP (exp
, 0);
1041 if (GET_CODE (x
) == SET
)
1043 rtx dest
= SET_DEST (x
);
1044 kill_value (dest
, vd
);
1045 set_value_regno (REGNO (dest
), GET_MODE (dest
), vd
);
1046 copy_value (dest
, SET_SRC (x
), vd
);
1047 ksvd
.ignore_set_reg
= dest
;
1048 set_regno
= REGNO (dest
);
1049 set_nregs
= REG_NREGS (dest
);
1054 get_call_reg_set_usage (insn
,
1055 ®s_invalidated_by_this_call
,
1056 regs_invalidated_by_call
);
1057 for (regno
= 0; regno
< FIRST_PSEUDO_REGISTER
; regno
++)
1058 if ((TEST_HARD_REG_BIT (regs_invalidated_by_this_call
, regno
)
1059 || (targetm
.hard_regno_call_part_clobbered
1060 (regno
, vd
->e
[regno
].mode
)))
1061 && (regno
< set_regno
|| regno
>= set_regno
+ set_nregs
))
1062 kill_value_regno (regno
, 1, vd
);
1064 /* If SET was seen in CALL_INSN_FUNCTION_USAGE, and SET_SRC
1065 of the SET isn't in regs_invalidated_by_call hard reg set,
1066 but instead among CLOBBERs on the CALL_INSN, we could wrongly
1067 assume the value in it is still live. */
1068 if (ksvd
.ignore_set_reg
)
1069 kill_clobbered_values (insn
, vd
);
1073 && REG_P (SET_DEST (set
))
1074 && REG_P (SET_SRC (set
)));
1075 bool noop_p
= (copy_p
1076 && rtx_equal_p (SET_DEST (set
), SET_SRC (set
)));
1078 /* If a noop move is using narrower mode than we have recorded,
1079 we need to either remove the noop move, or kill_set_value. */
1081 && partial_subreg_p (GET_MODE (SET_DEST (set
)),
1082 vd
->e
[REGNO (SET_DEST (set
))].mode
))
1084 if (noop_move_p (insn
))
1086 bool last
= insn
== BB_END (bb
);
1097 /* Notice stores. */
1098 note_stores (PATTERN (insn
), kill_set_value
, &ksvd
);
1100 /* Notice copies. */
1102 copy_value (SET_DEST (set
), SET_SRC (set
), vd
);
1105 if (insn
== BB_END (bb
))
1109 return anything_changed
;
1112 /* Dump the value chain data to stderr. */
1115 debug_value_data (struct value_data
*vd
)
1120 CLEAR_HARD_REG_SET (set
);
1122 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
1123 if (vd
->e
[i
].oldest_regno
== i
)
1125 if (vd
->e
[i
].mode
== VOIDmode
)
1127 if (vd
->e
[i
].next_regno
!= INVALID_REGNUM
)
1128 fprintf (stderr
, "[%u] Bad next_regno for empty chain (%u)\n",
1129 i
, vd
->e
[i
].next_regno
);
1133 SET_HARD_REG_BIT (set
, i
);
1134 fprintf (stderr
, "[%u %s] ", i
, GET_MODE_NAME (vd
->e
[i
].mode
));
1136 for (j
= vd
->e
[i
].next_regno
;
1137 j
!= INVALID_REGNUM
;
1138 j
= vd
->e
[j
].next_regno
)
1140 if (TEST_HARD_REG_BIT (set
, j
))
1142 fprintf (stderr
, "[%u] Loop in regno chain\n", j
);
1146 if (vd
->e
[j
].oldest_regno
!= i
)
1148 fprintf (stderr
, "[%u] Bad oldest_regno (%u)\n",
1149 j
, vd
->e
[j
].oldest_regno
);
1152 SET_HARD_REG_BIT (set
, j
);
1153 fprintf (stderr
, "[%u %s] ", j
, GET_MODE_NAME (vd
->e
[j
].mode
));
1155 fputc ('\n', stderr
);
1158 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
1159 if (! TEST_HARD_REG_BIT (set
, i
)
1160 && (vd
->e
[i
].mode
!= VOIDmode
1161 || vd
->e
[i
].oldest_regno
!= i
1162 || vd
->e
[i
].next_regno
!= INVALID_REGNUM
))
1163 fprintf (stderr
, "[%u] Non-empty reg in chain (%s %u %i)\n",
1164 i
, GET_MODE_NAME (vd
->e
[i
].mode
), vd
->e
[i
].oldest_regno
,
1165 vd
->e
[i
].next_regno
);
1168 /* Do copyprop_hardreg_forward_1 for a single basic block BB.
1169 DEBUG_INSN is skipped since we do not want to involve DF related
1170 staff as how it is handled in function pass_cprop_hardreg::execute.
1172 NOTE: Currently it is only used for shrink-wrap. Maybe extend it
1173 to handle DEBUG_INSN for other uses. */
1176 copyprop_hardreg_forward_bb_without_debug_insn (basic_block bb
)
1178 struct value_data
*vd
;
1179 vd
= XNEWVEC (struct value_data
, 1);
1180 init_value_data (vd
);
1182 skip_debug_insn_p
= true;
1183 copyprop_hardreg_forward_1 (bb
, vd
);
1185 skip_debug_insn_p
= false;
1189 validate_value_data (struct value_data
*vd
)
1194 CLEAR_HARD_REG_SET (set
);
1196 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
1197 if (vd
->e
[i
].oldest_regno
== i
)
1199 if (vd
->e
[i
].mode
== VOIDmode
)
1201 if (vd
->e
[i
].next_regno
!= INVALID_REGNUM
)
1202 internal_error ("validate_value_data: [%u] Bad next_regno for empty chain (%u)",
1203 i
, vd
->e
[i
].next_regno
);
1207 SET_HARD_REG_BIT (set
, i
);
1209 for (j
= vd
->e
[i
].next_regno
;
1210 j
!= INVALID_REGNUM
;
1211 j
= vd
->e
[j
].next_regno
)
1213 if (TEST_HARD_REG_BIT (set
, j
))
1214 internal_error ("validate_value_data: Loop in regno chain (%u)",
1216 if (vd
->e
[j
].oldest_regno
!= i
)
1217 internal_error ("validate_value_data: [%u] Bad oldest_regno (%u)",
1218 j
, vd
->e
[j
].oldest_regno
);
1220 SET_HARD_REG_BIT (set
, j
);
1224 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
1225 if (! TEST_HARD_REG_BIT (set
, i
)
1226 && (vd
->e
[i
].mode
!= VOIDmode
1227 || vd
->e
[i
].oldest_regno
!= i
1228 || vd
->e
[i
].next_regno
!= INVALID_REGNUM
))
1229 internal_error ("validate_value_data: [%u] Non-empty reg in chain (%s %u %i)",
1230 i
, GET_MODE_NAME (vd
->e
[i
].mode
), vd
->e
[i
].oldest_regno
,
1231 vd
->e
[i
].next_regno
);
1237 const pass_data pass_data_cprop_hardreg
=
1239 RTL_PASS
, /* type */
1240 "cprop_hardreg", /* name */
1241 OPTGROUP_NONE
, /* optinfo_flags */
1242 TV_CPROP_REGISTERS
, /* tv_id */
1243 0, /* properties_required */
1244 0, /* properties_provided */
1245 0, /* properties_destroyed */
1246 0, /* todo_flags_start */
1247 TODO_df_finish
, /* todo_flags_finish */
1250 class pass_cprop_hardreg
: public rtl_opt_pass
1253 pass_cprop_hardreg (gcc::context
*ctxt
)
1254 : rtl_opt_pass (pass_data_cprop_hardreg
, ctxt
)
1257 /* opt_pass methods: */
1258 virtual bool gate (function
*)
1260 return (optimize
> 0 && (flag_cprop_registers
));
1263 virtual unsigned int execute (function
*);
1265 }; // class pass_cprop_hardreg
1268 pass_cprop_hardreg::execute (function
*fun
)
1270 struct value_data
*all_vd
;
1272 bool analyze_called
= false;
1274 all_vd
= XNEWVEC (struct value_data
, last_basic_block_for_fn (fun
));
1276 auto_sbitmap
visited (last_basic_block_for_fn (fun
));
1277 bitmap_clear (visited
);
1279 FOR_EACH_BB_FN (bb
, fun
)
1281 bitmap_set_bit (visited
, bb
->index
);
1283 /* If a block has a single predecessor, that we've already
1284 processed, begin with the value data that was live at
1285 the end of the predecessor block. */
1286 /* ??? Ought to use more intelligent queuing of blocks. */
1287 if (single_pred_p (bb
)
1288 && bitmap_bit_p (visited
, single_pred (bb
)->index
)
1289 && ! (single_pred_edge (bb
)->flags
& (EDGE_ABNORMAL_CALL
| EDGE_EH
)))
1291 all_vd
[bb
->index
] = all_vd
[single_pred (bb
)->index
];
1292 if (all_vd
[bb
->index
].n_debug_insn_changes
)
1296 for (regno
= 0; regno
< FIRST_PSEUDO_REGISTER
; regno
++)
1298 if (all_vd
[bb
->index
].e
[regno
].debug_insn_changes
)
1300 all_vd
[bb
->index
].e
[regno
].debug_insn_changes
= NULL
;
1301 if (--all_vd
[bb
->index
].n_debug_insn_changes
== 0)
1308 init_value_data (all_vd
+ bb
->index
);
1310 copyprop_hardreg_forward_1 (bb
, all_vd
+ bb
->index
);
1313 if (MAY_HAVE_DEBUG_INSNS
)
1315 FOR_EACH_BB_FN (bb
, fun
)
1316 if (bitmap_bit_p (visited
, bb
->index
)
1317 && all_vd
[bb
->index
].n_debug_insn_changes
)
1322 if (!analyze_called
)
1325 analyze_called
= true;
1327 live
= df_get_live_out (bb
);
1328 for (regno
= 0; regno
< FIRST_PSEUDO_REGISTER
; regno
++)
1329 if (all_vd
[bb
->index
].e
[regno
].debug_insn_changes
)
1331 if (REGNO_REG_SET_P (live
, regno
))
1332 apply_debug_insn_changes (all_vd
+ bb
->index
, regno
);
1333 if (all_vd
[bb
->index
].n_debug_insn_changes
== 0)
1338 queued_debug_insn_change_pool
.release ();
1348 make_pass_cprop_hardreg (gcc::context
*ctxt
)
1350 return new pass_cprop_hardreg (ctxt
);