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"
35 #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
;
56 /* Pool allocation new operator. */
57 inline void *operator new (size_t)
59 return pool
.allocate ();
62 /* Delete operator utilizing pool allocation. */
63 inline void operator delete (void *ptr
)
65 pool
.remove ((queued_debug_insn_change
*) ptr
);
68 /* Memory allocation pool. */
69 static pool_allocator
<queued_debug_insn_change
> pool
;
72 /* For each register, we have a list of registers that contain the same
73 value. The OLDEST_REGNO field points to the head of the list, and
74 the NEXT_REGNO field runs through the list. The MODE field indicates
75 what mode the data is known to be in; this field is VOIDmode when the
76 register is not known to contain valid data. */
78 struct value_data_entry
81 unsigned int oldest_regno
;
82 unsigned int next_regno
;
83 struct queued_debug_insn_change
*debug_insn_changes
;
88 struct value_data_entry e
[FIRST_PSEUDO_REGISTER
];
89 unsigned int max_value_regs
;
90 unsigned int n_debug_insn_changes
;
93 pool_allocator
<queued_debug_insn_change
> queued_debug_insn_change::pool
94 ("debug insn changes pool", 256);
96 static bool skip_debug_insn_p
;
98 static void kill_value_one_regno (unsigned, struct value_data
*);
99 static void kill_value_regno (unsigned, unsigned, struct value_data
*);
100 static void kill_value (const_rtx
, struct value_data
*);
101 static void set_value_regno (unsigned, machine_mode
, struct value_data
*);
102 static void init_value_data (struct value_data
*);
103 static void kill_clobbered_value (rtx
, const_rtx
, void *);
104 static void kill_set_value (rtx
, const_rtx
, void *);
105 static void copy_value (rtx
, rtx
, struct value_data
*);
106 static bool mode_change_ok (machine_mode
, machine_mode
,
108 static rtx
maybe_mode_change (machine_mode
, machine_mode
,
109 machine_mode
, unsigned int, unsigned int);
110 static rtx
find_oldest_value_reg (enum reg_class
, rtx
, struct value_data
*);
111 static bool replace_oldest_value_reg (rtx
*, enum reg_class
, rtx_insn
*,
112 struct value_data
*);
113 static bool replace_oldest_value_addr (rtx
*, enum reg_class
,
114 machine_mode
, addr_space_t
,
115 rtx_insn
*, struct value_data
*);
116 static bool replace_oldest_value_mem (rtx
, rtx_insn
*, struct value_data
*);
117 static bool copyprop_hardreg_forward_1 (basic_block
, struct value_data
*);
118 extern void debug_value_data (struct value_data
*);
119 #ifdef ENABLE_CHECKING
120 static void validate_value_data (struct value_data
*);
123 /* Free all queued updates for DEBUG_INSNs that change some reg to
127 free_debug_insn_changes (struct value_data
*vd
, unsigned int regno
)
129 struct queued_debug_insn_change
*cur
, *next
;
130 for (cur
= vd
->e
[regno
].debug_insn_changes
; cur
; cur
= next
)
133 --vd
->n_debug_insn_changes
;
136 vd
->e
[regno
].debug_insn_changes
= NULL
;
139 /* Kill register REGNO. This involves removing it from any value
140 lists, and resetting the value mode to VOIDmode. This is only a
141 helper function; it does not handle any hard registers overlapping
145 kill_value_one_regno (unsigned int regno
, struct value_data
*vd
)
147 unsigned int i
, next
;
149 if (vd
->e
[regno
].oldest_regno
!= regno
)
151 for (i
= vd
->e
[regno
].oldest_regno
;
152 vd
->e
[i
].next_regno
!= regno
;
153 i
= vd
->e
[i
].next_regno
)
155 vd
->e
[i
].next_regno
= vd
->e
[regno
].next_regno
;
157 else if ((next
= vd
->e
[regno
].next_regno
) != INVALID_REGNUM
)
159 for (i
= next
; i
!= INVALID_REGNUM
; i
= vd
->e
[i
].next_regno
)
160 vd
->e
[i
].oldest_regno
= next
;
163 vd
->e
[regno
].mode
= VOIDmode
;
164 vd
->e
[regno
].oldest_regno
= regno
;
165 vd
->e
[regno
].next_regno
= INVALID_REGNUM
;
166 if (vd
->e
[regno
].debug_insn_changes
)
167 free_debug_insn_changes (vd
, regno
);
169 #ifdef ENABLE_CHECKING
170 validate_value_data (vd
);
174 /* Kill the value in register REGNO for NREGS, and any other registers
175 whose values overlap. */
178 kill_value_regno (unsigned int regno
, unsigned int nregs
,
179 struct value_data
*vd
)
183 /* Kill the value we're told to kill. */
184 for (j
= 0; j
< nregs
; ++j
)
185 kill_value_one_regno (regno
+ j
, vd
);
187 /* Kill everything that overlapped what we're told to kill. */
188 if (regno
< vd
->max_value_regs
)
191 j
= regno
- vd
->max_value_regs
;
192 for (; j
< regno
; ++j
)
195 if (vd
->e
[j
].mode
== VOIDmode
)
197 n
= hard_regno_nregs
[j
][vd
->e
[j
].mode
];
199 for (i
= 0; i
< n
; ++i
)
200 kill_value_one_regno (j
+ i
, vd
);
204 /* Kill X. This is a convenience function wrapping kill_value_regno
205 so that we mind the mode the register is in. */
208 kill_value (const_rtx x
, struct value_data
*vd
)
210 if (GET_CODE (x
) == SUBREG
)
212 rtx tmp
= simplify_subreg (GET_MODE (x
), SUBREG_REG (x
),
213 GET_MODE (SUBREG_REG (x
)), SUBREG_BYTE (x
));
214 x
= tmp
? tmp
: SUBREG_REG (x
);
217 kill_value_regno (REGNO (x
), REG_NREGS (x
), vd
);
220 /* Remember that REGNO is valid in MODE. */
223 set_value_regno (unsigned int regno
, machine_mode mode
,
224 struct value_data
*vd
)
228 vd
->e
[regno
].mode
= mode
;
230 nregs
= hard_regno_nregs
[regno
][mode
];
231 if (nregs
> vd
->max_value_regs
)
232 vd
->max_value_regs
= nregs
;
235 /* Initialize VD such that there are no known relationships between regs. */
238 init_value_data (struct value_data
*vd
)
241 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
243 vd
->e
[i
].mode
= VOIDmode
;
244 vd
->e
[i
].oldest_regno
= i
;
245 vd
->e
[i
].next_regno
= INVALID_REGNUM
;
246 vd
->e
[i
].debug_insn_changes
= NULL
;
248 vd
->max_value_regs
= 0;
249 vd
->n_debug_insn_changes
= 0;
252 /* Called through note_stores. If X is clobbered, kill its value. */
255 kill_clobbered_value (rtx x
, const_rtx set
, void *data
)
257 struct value_data
*const vd
= (struct value_data
*) data
;
258 if (GET_CODE (set
) == CLOBBER
)
262 /* A structure passed as data to kill_set_value through note_stores. */
263 struct kill_set_value_data
265 struct value_data
*vd
;
269 /* Called through note_stores. If X is set, not clobbered, kill its
270 current value and install it as the root of its own value list. */
273 kill_set_value (rtx x
, const_rtx set
, void *data
)
275 struct kill_set_value_data
*ksvd
= (struct kill_set_value_data
*) data
;
276 if (rtx_equal_p (x
, ksvd
->ignore_set_reg
))
278 if (GET_CODE (set
) != CLOBBER
)
280 kill_value (x
, ksvd
->vd
);
282 set_value_regno (REGNO (x
), GET_MODE (x
), ksvd
->vd
);
286 /* Kill any register used in X as the base of an auto-increment expression,
287 and install that register as the root of its own value list. */
290 kill_autoinc_value (rtx_insn
*insn
, struct value_data
*vd
)
292 subrtx_iterator::array_type array
;
293 FOR_EACH_SUBRTX (iter
, array
, PATTERN (insn
), NONCONST
)
296 if (GET_RTX_CLASS (GET_CODE (x
)) == RTX_AUTOINC
)
300 set_value_regno (REGNO (x
), GET_MODE (x
), vd
);
301 iter
.skip_subrtxes ();
306 /* Assert that SRC has been copied to DEST. Adjust the data structures
307 to reflect that SRC contains an older copy of the shared value. */
310 copy_value (rtx dest
, rtx src
, struct value_data
*vd
)
312 unsigned int dr
= REGNO (dest
);
313 unsigned int sr
= REGNO (src
);
317 /* ??? At present, it's possible to see noop sets. It'd be nice if
318 this were cleaned up beforehand... */
322 /* Do not propagate copies to the stack pointer, as that can leave
323 memory accesses with no scheduling dependency on the stack update. */
324 if (dr
== STACK_POINTER_REGNUM
)
327 /* Likewise with the frame pointer, if we're using one. */
328 if (frame_pointer_needed
&& dr
== HARD_FRAME_POINTER_REGNUM
)
331 /* Do not propagate copies to fixed or global registers, patterns
332 can be relying to see particular fixed register or users can
333 expect the chosen global register in asm. */
334 if (fixed_regs
[dr
] || global_regs
[dr
])
337 /* If SRC and DEST overlap, don't record anything. */
338 dn
= REG_NREGS (dest
);
339 sn
= REG_NREGS (src
);
340 if ((dr
> sr
&& dr
< sr
+ sn
)
341 || (sr
> dr
&& sr
< dr
+ dn
))
344 /* If SRC had no assigned mode (i.e. we didn't know it was live)
345 assign it now and assume the value came from an input argument
347 if (vd
->e
[sr
].mode
== VOIDmode
)
348 set_value_regno (sr
, vd
->e
[dr
].mode
, vd
);
350 /* If we are narrowing the input to a smaller number of hard regs,
351 and it is in big endian, we are really extracting a high part.
352 Since we generally associate a low part of a value with the value itself,
353 we must not do the same for the high part.
354 Note we can still get low parts for the same mode combination through
355 a two-step copy involving differently sized hard regs.
356 Assume hard regs fr* are 32 bits bits each, while r* are 64 bits each:
357 (set (reg:DI r0) (reg:DI fr0))
358 (set (reg:SI fr2) (reg:SI r0))
359 loads the low part of (reg:DI fr0) - i.e. fr1 - into fr2, while:
360 (set (reg:SI fr2) (reg:SI fr0))
361 loads the high part of (reg:DI fr0) into fr2.
363 We can't properly represent the latter case in our tables, so don't
364 record anything then. */
365 else if (sn
< (unsigned int) hard_regno_nregs
[sr
][vd
->e
[sr
].mode
]
366 && (GET_MODE_SIZE (vd
->e
[sr
].mode
) > UNITS_PER_WORD
367 ? WORDS_BIG_ENDIAN
: BYTES_BIG_ENDIAN
))
370 /* If SRC had been assigned a mode narrower than the copy, we can't
371 link DEST into the chain, because not all of the pieces of the
372 copy came from oldest_regno. */
373 else if (sn
> (unsigned int) hard_regno_nregs
[sr
][vd
->e
[sr
].mode
])
376 /* Link DR at the end of the value chain used by SR. */
378 vd
->e
[dr
].oldest_regno
= vd
->e
[sr
].oldest_regno
;
380 for (i
= sr
; vd
->e
[i
].next_regno
!= INVALID_REGNUM
; i
= vd
->e
[i
].next_regno
)
382 vd
->e
[i
].next_regno
= dr
;
384 #ifdef ENABLE_CHECKING
385 validate_value_data (vd
);
389 /* Return true if a mode change from ORIG to NEW is allowed for REGNO. */
392 mode_change_ok (machine_mode orig_mode
, machine_mode new_mode
,
393 unsigned int regno ATTRIBUTE_UNUSED
)
395 if (GET_MODE_SIZE (orig_mode
) < GET_MODE_SIZE (new_mode
))
398 #ifdef CANNOT_CHANGE_MODE_CLASS
399 return !REG_CANNOT_CHANGE_MODE_P (regno
, orig_mode
, new_mode
);
405 /* Register REGNO was originally set in ORIG_MODE. It - or a copy of it -
406 was copied in COPY_MODE to COPY_REGNO, and then COPY_REGNO was accessed
408 Return a NEW_MODE rtx for REGNO if that's OK, otherwise return NULL_RTX. */
411 maybe_mode_change (machine_mode orig_mode
, machine_mode copy_mode
,
412 machine_mode new_mode
, unsigned int regno
,
413 unsigned int copy_regno ATTRIBUTE_UNUSED
)
415 if (GET_MODE_SIZE (copy_mode
) < GET_MODE_SIZE (orig_mode
)
416 && GET_MODE_SIZE (copy_mode
) < GET_MODE_SIZE (new_mode
))
419 if (orig_mode
== new_mode
)
420 return gen_raw_REG (new_mode
, regno
);
421 else if (mode_change_ok (orig_mode
, new_mode
, regno
))
423 int copy_nregs
= hard_regno_nregs
[copy_regno
][copy_mode
];
424 int use_nregs
= hard_regno_nregs
[copy_regno
][new_mode
];
426 = GET_MODE_SIZE (copy_mode
) / copy_nregs
* (copy_nregs
- use_nregs
);
428 = GET_MODE_SIZE (orig_mode
) - GET_MODE_SIZE (new_mode
) - copy_offset
;
429 int byteoffset
= offset
% UNITS_PER_WORD
;
430 int wordoffset
= offset
- byteoffset
;
432 offset
= ((WORDS_BIG_ENDIAN
? wordoffset
: 0)
433 + (BYTES_BIG_ENDIAN
? byteoffset
: 0));
434 regno
+= subreg_regno_offset (regno
, orig_mode
, offset
, new_mode
);
435 if (HARD_REGNO_MODE_OK (regno
, new_mode
))
436 return gen_raw_REG (new_mode
, regno
);
441 /* Find the oldest copy of the value contained in REGNO that is in
442 register class CL and has mode MODE. If found, return an rtx
443 of that oldest register, otherwise return NULL. */
446 find_oldest_value_reg (enum reg_class cl
, rtx reg
, struct value_data
*vd
)
448 unsigned int regno
= REGNO (reg
);
449 machine_mode mode
= GET_MODE (reg
);
452 /* If we are accessing REG in some mode other that what we set it in,
453 make sure that the replacement is valid. In particular, consider
454 (set (reg:DI r11) (...))
455 (set (reg:SI r9) (reg:SI r11))
456 (set (reg:SI r10) (...))
457 (set (...) (reg:DI r9))
458 Replacing r9 with r11 is invalid. */
459 if (mode
!= vd
->e
[regno
].mode
)
461 if (hard_regno_nregs
[regno
][mode
]
462 > hard_regno_nregs
[regno
][vd
->e
[regno
].mode
])
466 for (i
= vd
->e
[regno
].oldest_regno
; i
!= regno
; i
= vd
->e
[i
].next_regno
)
468 machine_mode oldmode
= vd
->e
[i
].mode
;
471 if (!in_hard_reg_set_p (reg_class_contents
[cl
], mode
, i
))
474 new_rtx
= maybe_mode_change (oldmode
, vd
->e
[regno
].mode
, mode
, i
, regno
);
477 ORIGINAL_REGNO (new_rtx
) = ORIGINAL_REGNO (reg
);
478 REG_ATTRS (new_rtx
) = REG_ATTRS (reg
);
479 REG_POINTER (new_rtx
) = REG_POINTER (reg
);
487 /* If possible, replace the register at *LOC with the oldest register
488 in register class CL. Return true if successfully replaced. */
491 replace_oldest_value_reg (rtx
*loc
, enum reg_class cl
, rtx_insn
*insn
,
492 struct value_data
*vd
)
494 rtx new_rtx
= find_oldest_value_reg (cl
, *loc
, vd
);
495 if (new_rtx
&& (!DEBUG_INSN_P (insn
) || !skip_debug_insn_p
))
497 if (DEBUG_INSN_P (insn
))
499 struct queued_debug_insn_change
*change
;
502 fprintf (dump_file
, "debug_insn %u: queued replacing reg %u with %u\n",
503 INSN_UID (insn
), REGNO (*loc
), REGNO (new_rtx
));
505 change
= new queued_debug_insn_change
;
506 change
->next
= vd
->e
[REGNO (new_rtx
)].debug_insn_changes
;
509 change
->new_rtx
= new_rtx
;
510 vd
->e
[REGNO (new_rtx
)].debug_insn_changes
= change
;
511 ++vd
->n_debug_insn_changes
;
515 fprintf (dump_file
, "insn %u: replaced reg %u with %u\n",
516 INSN_UID (insn
), REGNO (*loc
), REGNO (new_rtx
));
518 validate_change (insn
, loc
, new_rtx
, 1);
524 /* Similar to replace_oldest_value_reg, but *LOC contains an address.
525 Adapted from find_reloads_address_1. CL is INDEX_REG_CLASS or
526 BASE_REG_CLASS depending on how the register is being considered. */
529 replace_oldest_value_addr (rtx
*loc
, enum reg_class cl
,
530 machine_mode mode
, addr_space_t as
,
531 rtx_insn
*insn
, struct value_data
*vd
)
534 RTX_CODE code
= GET_CODE (x
);
537 bool changed
= false;
542 if (DEBUG_INSN_P (insn
))
546 rtx orig_op0
= XEXP (x
, 0);
547 rtx orig_op1
= XEXP (x
, 1);
548 RTX_CODE code0
= GET_CODE (orig_op0
);
549 RTX_CODE code1
= GET_CODE (orig_op1
);
554 enum rtx_code index_code
= SCRATCH
;
556 if (GET_CODE (op0
) == SUBREG
)
558 op0
= SUBREG_REG (op0
);
559 code0
= GET_CODE (op0
);
562 if (GET_CODE (op1
) == SUBREG
)
564 op1
= SUBREG_REG (op1
);
565 code1
= GET_CODE (op1
);
568 if (code0
== MULT
|| code0
== SIGN_EXTEND
|| code0
== TRUNCATE
569 || code0
== ZERO_EXTEND
|| code1
== MEM
)
573 index_code
= GET_CODE (*locI
);
575 else if (code1
== MULT
|| code1
== SIGN_EXTEND
|| code1
== TRUNCATE
576 || code1
== ZERO_EXTEND
|| code0
== MEM
)
580 index_code
= GET_CODE (*locI
);
582 else if (code0
== CONST_INT
|| code0
== CONST
583 || code0
== SYMBOL_REF
|| code0
== LABEL_REF
)
586 index_code
= GET_CODE (XEXP (x
, 0));
588 else if (code1
== CONST_INT
|| code1
== CONST
589 || code1
== SYMBOL_REF
|| code1
== LABEL_REF
)
592 index_code
= GET_CODE (XEXP (x
, 1));
594 else if (code0
== REG
&& code1
== REG
)
597 unsigned regno0
= REGNO (op0
), regno1
= REGNO (op1
);
599 if (REGNO_OK_FOR_INDEX_P (regno1
)
600 && regno_ok_for_base_p (regno0
, mode
, as
, PLUS
, REG
))
602 else if (REGNO_OK_FOR_INDEX_P (regno0
)
603 && regno_ok_for_base_p (regno1
, mode
, as
, PLUS
, REG
))
605 else if (regno_ok_for_base_p (regno0
, mode
, as
, PLUS
, REG
)
606 || REGNO_OK_FOR_INDEX_P (regno1
))
608 else if (regno_ok_for_base_p (regno1
, mode
, as
, PLUS
, REG
))
613 locI
= &XEXP (x
, index_op
);
614 locB
= &XEXP (x
, !index_op
);
615 index_code
= GET_CODE (*locI
);
617 else if (code0
== REG
)
621 index_code
= GET_CODE (*locI
);
623 else if (code1
== REG
)
627 index_code
= GET_CODE (*locI
);
631 changed
|= replace_oldest_value_addr (locI
, INDEX_REG_CLASS
,
634 changed
|= replace_oldest_value_addr (locB
,
635 base_reg_class (mode
, as
, PLUS
,
650 return replace_oldest_value_mem (x
, insn
, vd
);
653 return replace_oldest_value_reg (loc
, cl
, insn
, vd
);
659 fmt
= GET_RTX_FORMAT (code
);
660 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
663 changed
|= replace_oldest_value_addr (&XEXP (x
, i
), cl
, mode
, as
,
665 else if (fmt
[i
] == 'E')
666 for (j
= XVECLEN (x
, i
) - 1; j
>= 0; j
--)
667 changed
|= replace_oldest_value_addr (&XVECEXP (x
, i
, j
), cl
,
674 /* Similar to replace_oldest_value_reg, but X contains a memory. */
677 replace_oldest_value_mem (rtx x
, rtx_insn
*insn
, struct value_data
*vd
)
681 if (DEBUG_INSN_P (insn
))
684 cl
= base_reg_class (GET_MODE (x
), MEM_ADDR_SPACE (x
), MEM
, SCRATCH
);
686 return replace_oldest_value_addr (&XEXP (x
, 0), cl
,
687 GET_MODE (x
), MEM_ADDR_SPACE (x
),
691 /* Apply all queued updates for DEBUG_INSNs that change some reg to
695 apply_debug_insn_changes (struct value_data
*vd
, unsigned int regno
)
697 struct queued_debug_insn_change
*change
;
698 rtx_insn
*last_insn
= vd
->e
[regno
].debug_insn_changes
->insn
;
700 for (change
= vd
->e
[regno
].debug_insn_changes
;
702 change
= change
->next
)
704 if (last_insn
!= change
->insn
)
706 apply_change_group ();
707 last_insn
= change
->insn
;
709 validate_change (change
->insn
, change
->loc
, change
->new_rtx
, 1);
711 apply_change_group ();
714 /* Called via note_uses, for all used registers in a real insn
715 apply DEBUG_INSN changes that change registers to the used
719 cprop_find_used_regs (rtx
*loc
, void *data
)
721 struct value_data
*const vd
= (struct value_data
*) data
;
722 subrtx_iterator::array_type array
;
723 FOR_EACH_SUBRTX (iter
, array
, *loc
, NONCONST
)
728 unsigned int regno
= REGNO (x
);
729 if (vd
->e
[regno
].debug_insn_changes
)
731 apply_debug_insn_changes (vd
, regno
);
732 free_debug_insn_changes (vd
, regno
);
738 /* Apply clobbers of INSN in PATTERN and C_I_F_U to value_data VD. */
741 kill_clobbered_values (rtx_insn
*insn
, struct value_data
*vd
)
743 note_stores (PATTERN (insn
), kill_clobbered_value
, vd
);
749 for (exp
= CALL_INSN_FUNCTION_USAGE (insn
); exp
; exp
= XEXP (exp
, 1))
751 rtx x
= XEXP (exp
, 0);
752 if (GET_CODE (x
) == CLOBBER
)
753 kill_value (SET_DEST (x
), vd
);
758 /* Perform the forward copy propagation on basic block BB. */
761 copyprop_hardreg_forward_1 (basic_block bb
, struct value_data
*vd
)
763 bool anything_changed
= false;
766 for (insn
= BB_HEAD (bb
); ; insn
= NEXT_INSN (insn
))
768 int n_ops
, i
, predicated
;
769 bool is_asm
, any_replacements
;
772 bool replaced
[MAX_RECOG_OPERANDS
];
773 bool changed
= false;
774 struct kill_set_value_data ksvd
;
776 if (!NONDEBUG_INSN_P (insn
))
778 if (DEBUG_INSN_P (insn
))
780 rtx loc
= INSN_VAR_LOCATION_LOC (insn
);
781 if (!VAR_LOC_UNKNOWN_P (loc
))
782 replace_oldest_value_addr (&INSN_VAR_LOCATION_LOC (insn
),
783 ALL_REGS
, GET_MODE (loc
),
784 ADDR_SPACE_GENERIC
, insn
, vd
);
787 if (insn
== BB_END (bb
))
793 set
= single_set (insn
);
794 extract_constrain_insn (insn
);
795 preprocess_constraints (insn
);
796 const operand_alternative
*op_alt
= which_op_alt ();
797 n_ops
= recog_data
.n_operands
;
798 is_asm
= asm_noperands (PATTERN (insn
)) >= 0;
800 /* Simplify the code below by promoting OP_OUT to OP_INOUT
801 in predicated instructions. */
803 predicated
= GET_CODE (PATTERN (insn
)) == COND_EXEC
;
804 for (i
= 0; i
< n_ops
; ++i
)
806 int matches
= op_alt
[i
].matches
;
807 if (matches
>= 0 || op_alt
[i
].matched
>= 0
808 || (predicated
&& recog_data
.operand_type
[i
] == OP_OUT
))
809 recog_data
.operand_type
[i
] = OP_INOUT
;
812 /* Apply changes to earlier DEBUG_INSNs if possible. */
813 if (vd
->n_debug_insn_changes
)
814 note_uses (&PATTERN (insn
), cprop_find_used_regs
, vd
);
816 /* For each earlyclobber operand, zap the value data. */
817 for (i
= 0; i
< n_ops
; i
++)
818 if (op_alt
[i
].earlyclobber
)
819 kill_value (recog_data
.operand
[i
], vd
);
821 /* Within asms, a clobber cannot overlap inputs or outputs.
822 I wouldn't think this were true for regular insns, but
823 scan_rtx treats them like that... */
824 kill_clobbered_values (insn
, vd
);
826 /* Kill all auto-incremented values. */
827 /* ??? REG_INC is useless, since stack pushes aren't done that way. */
828 kill_autoinc_value (insn
, vd
);
830 /* Kill all early-clobbered operands. */
831 for (i
= 0; i
< n_ops
; i
++)
832 if (op_alt
[i
].earlyclobber
)
833 kill_value (recog_data
.operand
[i
], vd
);
835 /* If we have dead sets in the insn, then we need to note these as we
837 for (link
= REG_NOTES (insn
); link
; link
= XEXP (link
, 1))
839 if (REG_NOTE_KIND (link
) == REG_UNUSED
)
841 kill_value (XEXP (link
, 0), vd
);
842 /* Furthermore, if the insn looked like a single-set,
843 but the dead store kills the source value of that
844 set, then we can no-longer use the plain move
845 special case below. */
847 && reg_overlap_mentioned_p (XEXP (link
, 0), SET_SRC (set
)))
852 /* Special-case plain move instructions, since we may well
853 be able to do the move from a different register class. */
854 if (set
&& REG_P (SET_SRC (set
)))
856 rtx src
= SET_SRC (set
);
857 unsigned int regno
= REGNO (src
);
858 machine_mode mode
= GET_MODE (src
);
862 /* If we are accessing SRC in some mode other that what we
863 set it in, make sure that the replacement is valid. */
864 if (mode
!= vd
->e
[regno
].mode
)
866 if (hard_regno_nregs
[regno
][mode
]
867 > hard_regno_nregs
[regno
][vd
->e
[regno
].mode
])
868 goto no_move_special_case
;
870 /* And likewise, if we are narrowing on big endian the transformation
872 if (hard_regno_nregs
[regno
][mode
]
873 < hard_regno_nregs
[regno
][vd
->e
[regno
].mode
]
874 && (GET_MODE_SIZE (vd
->e
[regno
].mode
) > UNITS_PER_WORD
875 ? WORDS_BIG_ENDIAN
: BYTES_BIG_ENDIAN
))
876 goto no_move_special_case
;
879 /* If the destination is also a register, try to find a source
880 register in the same class. */
881 if (REG_P (SET_DEST (set
)))
883 new_rtx
= find_oldest_value_reg (REGNO_REG_CLASS (regno
), src
, vd
);
884 if (new_rtx
&& validate_change (insn
, &SET_SRC (set
), new_rtx
, 0))
888 "insn %u: replaced reg %u with %u\n",
889 INSN_UID (insn
), regno
, REGNO (new_rtx
));
891 goto did_replacement
;
893 /* We need to re-extract as validate_change clobbers
895 extract_constrain_insn (insn
);
896 preprocess_constraints (insn
);
899 /* Otherwise, try all valid registers and see if its valid. */
900 for (i
= vd
->e
[regno
].oldest_regno
; i
!= regno
;
901 i
= vd
->e
[i
].next_regno
)
903 new_rtx
= maybe_mode_change (vd
->e
[i
].mode
, vd
->e
[regno
].mode
,
905 if (new_rtx
!= NULL_RTX
)
907 if (validate_change (insn
, &SET_SRC (set
), new_rtx
, 0))
909 ORIGINAL_REGNO (new_rtx
) = ORIGINAL_REGNO (src
);
910 REG_ATTRS (new_rtx
) = REG_ATTRS (src
);
911 REG_POINTER (new_rtx
) = REG_POINTER (src
);
914 "insn %u: replaced reg %u with %u\n",
915 INSN_UID (insn
), regno
, REGNO (new_rtx
));
917 goto did_replacement
;
919 /* We need to re-extract as validate_change clobbers
921 extract_constrain_insn (insn
);
922 preprocess_constraints (insn
);
926 no_move_special_case
:
928 any_replacements
= false;
930 /* For each input operand, replace a hard register with the
931 eldest live copy that's in an appropriate register class. */
932 for (i
= 0; i
< n_ops
; i
++)
936 /* Don't scan match_operand here, since we've no reg class
937 information to pass down. Any operands that we could
938 substitute in will be represented elsewhere. */
939 if (recog_data
.constraints
[i
][0] == '\0')
942 /* Don't replace in asms intentionally referencing hard regs. */
943 if (is_asm
&& REG_P (recog_data
.operand
[i
])
944 && (REGNO (recog_data
.operand
[i
])
945 == ORIGINAL_REGNO (recog_data
.operand
[i
])))
948 if (recog_data
.operand_type
[i
] == OP_IN
)
950 if (op_alt
[i
].is_address
)
952 = replace_oldest_value_addr (recog_data
.operand_loc
[i
],
953 alternative_class (op_alt
, i
),
954 VOIDmode
, ADDR_SPACE_GENERIC
,
956 else if (REG_P (recog_data
.operand
[i
]))
958 = replace_oldest_value_reg (recog_data
.operand_loc
[i
],
959 alternative_class (op_alt
, i
),
961 else if (MEM_P (recog_data
.operand
[i
]))
962 replaced
[i
] = replace_oldest_value_mem (recog_data
.operand
[i
],
965 else if (MEM_P (recog_data
.operand
[i
]))
966 replaced
[i
] = replace_oldest_value_mem (recog_data
.operand
[i
],
969 /* If we performed any replacement, update match_dups. */
975 new_rtx
= *recog_data
.operand_loc
[i
];
976 recog_data
.operand
[i
] = new_rtx
;
977 for (j
= 0; j
< recog_data
.n_dups
; j
++)
978 if (recog_data
.dup_num
[j
] == i
)
979 validate_unshare_change (insn
, recog_data
.dup_loc
[j
], new_rtx
, 1);
981 any_replacements
= true;
985 if (any_replacements
)
987 if (! apply_change_group ())
989 for (i
= 0; i
< n_ops
; i
++)
992 rtx old
= *recog_data
.operand_loc
[i
];
993 recog_data
.operand
[i
] = old
;
998 "insn %u: reg replacements not verified\n",
1008 anything_changed
= true;
1010 /* If something changed, perhaps further changes to earlier
1011 DEBUG_INSNs can be applied. */
1012 if (vd
->n_debug_insn_changes
)
1013 note_uses (&PATTERN (insn
), cprop_find_used_regs
, vd
);
1017 ksvd
.ignore_set_reg
= NULL_RTX
;
1019 /* Clobber call-clobbered registers. */
1022 unsigned int set_regno
= INVALID_REGNUM
;
1023 unsigned int set_nregs
= 0;
1026 HARD_REG_SET regs_invalidated_by_this_call
;
1028 for (exp
= CALL_INSN_FUNCTION_USAGE (insn
); exp
; exp
= XEXP (exp
, 1))
1030 rtx x
= XEXP (exp
, 0);
1031 if (GET_CODE (x
) == SET
)
1033 rtx dest
= SET_DEST (x
);
1034 kill_value (dest
, vd
);
1035 set_value_regno (REGNO (dest
), GET_MODE (dest
), vd
);
1036 copy_value (dest
, SET_SRC (x
), vd
);
1037 ksvd
.ignore_set_reg
= dest
;
1038 set_regno
= REGNO (dest
);
1039 set_nregs
= REG_NREGS (dest
);
1044 get_call_reg_set_usage (insn
,
1045 ®s_invalidated_by_this_call
,
1046 regs_invalidated_by_call
);
1047 for (regno
= 0; regno
< FIRST_PSEUDO_REGISTER
; regno
++)
1048 if ((TEST_HARD_REG_BIT (regs_invalidated_by_this_call
, regno
)
1049 || HARD_REGNO_CALL_PART_CLOBBERED (regno
, vd
->e
[regno
].mode
))
1050 && (regno
< set_regno
|| regno
>= set_regno
+ set_nregs
))
1051 kill_value_regno (regno
, 1, vd
);
1053 /* If SET was seen in CALL_INSN_FUNCTION_USAGE, and SET_SRC
1054 of the SET isn't in regs_invalidated_by_call hard reg set,
1055 but instead among CLOBBERs on the CALL_INSN, we could wrongly
1056 assume the value in it is still live. */
1057 if (ksvd
.ignore_set_reg
)
1058 kill_clobbered_values (insn
, vd
);
1062 && REG_P (SET_DEST (set
))
1063 && REG_P (SET_SRC (set
)));
1064 bool noop_p
= (copy_p
1065 && rtx_equal_p (SET_DEST (set
), SET_SRC (set
)));
1069 /* Notice stores. */
1070 note_stores (PATTERN (insn
), kill_set_value
, &ksvd
);
1072 /* Notice copies. */
1074 copy_value (SET_DEST (set
), SET_SRC (set
), vd
);
1077 if (insn
== BB_END (bb
))
1081 return anything_changed
;
1084 /* Dump the value chain data to stderr. */
1087 debug_value_data (struct value_data
*vd
)
1092 CLEAR_HARD_REG_SET (set
);
1094 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
1095 if (vd
->e
[i
].oldest_regno
== i
)
1097 if (vd
->e
[i
].mode
== VOIDmode
)
1099 if (vd
->e
[i
].next_regno
!= INVALID_REGNUM
)
1100 fprintf (stderr
, "[%u] Bad next_regno for empty chain (%u)\n",
1101 i
, vd
->e
[i
].next_regno
);
1105 SET_HARD_REG_BIT (set
, i
);
1106 fprintf (stderr
, "[%u %s] ", i
, GET_MODE_NAME (vd
->e
[i
].mode
));
1108 for (j
= vd
->e
[i
].next_regno
;
1109 j
!= INVALID_REGNUM
;
1110 j
= vd
->e
[j
].next_regno
)
1112 if (TEST_HARD_REG_BIT (set
, j
))
1114 fprintf (stderr
, "[%u] Loop in regno chain\n", j
);
1118 if (vd
->e
[j
].oldest_regno
!= i
)
1120 fprintf (stderr
, "[%u] Bad oldest_regno (%u)\n",
1121 j
, vd
->e
[j
].oldest_regno
);
1124 SET_HARD_REG_BIT (set
, j
);
1125 fprintf (stderr
, "[%u %s] ", j
, GET_MODE_NAME (vd
->e
[j
].mode
));
1127 fputc ('\n', stderr
);
1130 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; ++i
)
1131 if (! TEST_HARD_REG_BIT (set
, i
)
1132 && (vd
->e
[i
].mode
!= VOIDmode
1133 || vd
->e
[i
].oldest_regno
!= i
1134 || vd
->e
[i
].next_regno
!= INVALID_REGNUM
))
1135 fprintf (stderr
, "[%u] Non-empty reg in chain (%s %u %i)\n",
1136 i
, GET_MODE_NAME (vd
->e
[i
].mode
), vd
->e
[i
].oldest_regno
,
1137 vd
->e
[i
].next_regno
);
1140 /* Do copyprop_hardreg_forward_1 for a single basic block BB.
1141 DEBUG_INSN is skipped since we do not want to involve DF related
1142 staff as how it is handled in function pass_cprop_hardreg::execute.
1144 NOTE: Currently it is only used for shrink-wrap. Maybe extend it
1145 to handle DEBUG_INSN for other uses. */
1148 copyprop_hardreg_forward_bb_without_debug_insn (basic_block bb
)
1150 struct value_data
*vd
;
1151 vd
= XNEWVEC (struct value_data
, 1);
1152 init_value_data (vd
);
1154 skip_debug_insn_p
= true;
1155 copyprop_hardreg_forward_1 (bb
, vd
);
1157 skip_debug_insn_p
= false;
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
);
1210 const pass_data pass_data_cprop_hardreg
=
1212 RTL_PASS
, /* type */
1213 "cprop_hardreg", /* name */
1214 OPTGROUP_NONE
, /* optinfo_flags */
1215 TV_CPROP_REGISTERS
, /* tv_id */
1216 0, /* properties_required */
1217 0, /* properties_provided */
1218 0, /* properties_destroyed */
1219 0, /* todo_flags_start */
1220 TODO_df_finish
, /* todo_flags_finish */
1223 class pass_cprop_hardreg
: public rtl_opt_pass
1226 pass_cprop_hardreg (gcc::context
*ctxt
)
1227 : rtl_opt_pass (pass_data_cprop_hardreg
, ctxt
)
1230 /* opt_pass methods: */
1231 virtual bool gate (function
*)
1233 return (optimize
> 0 && (flag_cprop_registers
));
1236 virtual unsigned int execute (function
*);
1238 }; // class pass_cprop_hardreg
1241 pass_cprop_hardreg::execute (function
*fun
)
1243 struct value_data
*all_vd
;
1246 bool analyze_called
= false;
1248 all_vd
= XNEWVEC (struct value_data
, last_basic_block_for_fn (fun
));
1250 visited
= sbitmap_alloc (last_basic_block_for_fn (fun
));
1251 bitmap_clear (visited
);
1253 FOR_EACH_BB_FN (bb
, fun
)
1255 bitmap_set_bit (visited
, bb
->index
);
1257 /* If a block has a single predecessor, that we've already
1258 processed, begin with the value data that was live at
1259 the end of the predecessor block. */
1260 /* ??? Ought to use more intelligent queuing of blocks. */
1261 if (single_pred_p (bb
)
1262 && bitmap_bit_p (visited
, single_pred (bb
)->index
)
1263 && ! (single_pred_edge (bb
)->flags
& (EDGE_ABNORMAL_CALL
| EDGE_EH
)))
1265 all_vd
[bb
->index
] = all_vd
[single_pred (bb
)->index
];
1266 if (all_vd
[bb
->index
].n_debug_insn_changes
)
1270 for (regno
= 0; regno
< FIRST_PSEUDO_REGISTER
; regno
++)
1272 if (all_vd
[bb
->index
].e
[regno
].debug_insn_changes
)
1274 all_vd
[bb
->index
].e
[regno
].debug_insn_changes
= NULL
;
1275 if (--all_vd
[bb
->index
].n_debug_insn_changes
== 0)
1282 init_value_data (all_vd
+ bb
->index
);
1284 copyprop_hardreg_forward_1 (bb
, all_vd
+ bb
->index
);
1287 if (MAY_HAVE_DEBUG_INSNS
)
1289 FOR_EACH_BB_FN (bb
, fun
)
1290 if (bitmap_bit_p (visited
, bb
->index
)
1291 && all_vd
[bb
->index
].n_debug_insn_changes
)
1296 if (!analyze_called
)
1299 analyze_called
= true;
1301 live
= df_get_live_out (bb
);
1302 for (regno
= 0; regno
< FIRST_PSEUDO_REGISTER
; regno
++)
1303 if (all_vd
[bb
->index
].e
[regno
].debug_insn_changes
)
1305 if (REGNO_REG_SET_P (live
, regno
))
1306 apply_debug_insn_changes (all_vd
+ bb
->index
, regno
);
1307 if (all_vd
[bb
->index
].n_debug_insn_changes
== 0)
1312 queued_debug_insn_change::pool
.release ();
1315 sbitmap_free (visited
);
1323 make_pass_cprop_hardreg (gcc::context
*ctxt
)
1325 return new pass_cprop_hardreg (ctxt
);