1 /* Perform branch target register load optimizations.
2 Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
3 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
23 #include "coretypes.h"
26 #include "hard-reg-set.h"
33 #include "insn-attr.h"
37 #include "diagnostic-core.h"
38 #include "tree-pass.h"
42 /* Target register optimizations - these are performed after reload. */
44 typedef struct btr_def_group_s
46 struct btr_def_group_s
*next
;
48 struct btr_def_s
*members
;
51 typedef struct btr_user_s
53 struct btr_user_s
*next
;
57 /* If INSN has a single use of a single branch register, then
58 USE points to it within INSN. If there is more than
59 one branch register use, or the use is in some way ambiguous,
63 int first_reaching_def
;
64 char other_use_this_block
;
67 /* btr_def structs appear on three lists:
68 1. A list of all btr_def structures (head is
69 ALL_BTR_DEFS, linked by the NEXT field).
70 2. A list of branch reg definitions per basic block (head is
71 BB_BTR_DEFS[i], linked by the NEXT_THIS_BB field).
72 3. A list of all branch reg definitions belonging to the same
73 group (head is in a BTR_DEF_GROUP struct, linked by
74 NEXT_THIS_GROUP field). */
76 typedef struct btr_def_s
78 struct btr_def_s
*next_this_bb
;
79 struct btr_def_s
*next_this_group
;
85 /* For a branch register setting insn that has a constant
86 source (i.e. a label), group links together all the
87 insns with the same source. For other branch register
88 setting insns, group is NULL. */
91 /* If this def has a reaching use which is not a simple use
92 in a branch instruction, then has_ambiguous_use will be true,
93 and we will not attempt to migrate this definition. */
94 char has_ambiguous_use
;
95 /* live_range is an approximation to the true live range for this
96 def/use web, because it records the set of blocks that contain
97 the live range. There could be other live ranges for the same
98 branch register in that set of blocks, either in the block
99 containing the def (before the def), or in a block containing
100 a use (after the use). If there are such other live ranges, then
101 other_btr_uses_before_def or other_btr_uses_after_use must be set true
103 char other_btr_uses_before_def
;
104 char other_btr_uses_after_use
;
105 /* We set own_end when we have moved a definition into a dominator.
106 Thus, when a later combination removes this definition again, we know
107 to clear out trs_live_at_end again. */
112 static int issue_rate
;
114 static int basic_block_freq (const_basic_block
);
115 static int insn_sets_btr_p (const_rtx
, int, int *);
116 static rtx
*find_btr_use (rtx
);
117 static int btr_referenced_p (rtx
, rtx
*);
118 static int find_btr_reference (rtx
*, void *);
119 static void find_btr_def_group (btr_def_group
*, btr_def
);
120 static btr_def
add_btr_def (fibheap_t
, basic_block
, int, rtx
,
121 unsigned int, int, btr_def_group
*);
122 static btr_user
new_btr_user (basic_block
, int, rtx
);
123 static void dump_hard_reg_set (HARD_REG_SET
);
124 static void dump_btrs_live (int);
125 static void note_other_use_this_block (unsigned int, btr_user
);
126 static void compute_defs_uses_and_gen (fibheap_t
, btr_def
*,btr_user
*,
127 sbitmap
*, sbitmap
*, HARD_REG_SET
*);
128 static void compute_kill (sbitmap
*, sbitmap
*, HARD_REG_SET
*);
129 static void compute_out (sbitmap
*bb_out
, sbitmap
*, sbitmap
*, int);
130 static void link_btr_uses (btr_def
*, btr_user
*, sbitmap
*, sbitmap
*, int);
131 static void build_btr_def_use_webs (fibheap_t
);
132 static int block_at_edge_of_live_range_p (int, btr_def
);
133 static void clear_btr_from_live_range (btr_def def
);
134 static void add_btr_to_live_range (btr_def
, int);
135 static void augment_live_range (bitmap
, HARD_REG_SET
*, basic_block
,
137 static int choose_btr (HARD_REG_SET
);
138 static void combine_btr_defs (btr_def
, HARD_REG_SET
*);
139 static void btr_def_live_range (btr_def
, HARD_REG_SET
*);
140 static void move_btr_def (basic_block
, int, btr_def
, bitmap
, HARD_REG_SET
*);
141 static int migrate_btr_def (btr_def
, int);
142 static void migrate_btr_defs (enum reg_class
, int);
143 static int can_move_up (const_basic_block
, const_rtx
, int);
144 static void note_btr_set (rtx
, const_rtx
, void *);
146 /* The following code performs code motion of target load instructions
147 (instructions that set branch target registers), to move them
148 forward away from the branch instructions and out of loops (or,
149 more generally, from a more frequently executed place to a less
150 frequently executed place).
151 Moving target load instructions further in front of the branch
152 instruction that uses the target register value means that the hardware
153 has a better chance of preloading the instructions at the branch
154 target by the time the branch is reached. This avoids bubbles
155 when a taken branch needs to flush out the pipeline.
156 Moving target load instructions out of loops means they are executed
159 /* An obstack to hold the def-use web data structures built up for
160 migrating branch target load instructions. */
161 static struct obstack migrate_btrl_obstack
;
163 /* Array indexed by basic block number, giving the set of registers
164 live in that block. */
165 static HARD_REG_SET
*btrs_live
;
167 /* Array indexed by basic block number, giving the set of registers live at
168 the end of that block, including any uses by a final jump insn, if any. */
169 static HARD_REG_SET
*btrs_live_at_end
;
171 /* Set of all target registers that we are willing to allocate. */
172 static HARD_REG_SET all_btrs
;
174 /* Provide lower and upper bounds for target register numbers, so that
175 we don't need to search through all the hard registers all the time. */
176 static int first_btr
, last_btr
;
180 /* Return an estimate of the frequency of execution of block bb. */
182 basic_block_freq (const_basic_block bb
)
184 return bb
->frequency
;
187 static rtx
*btr_reference_found
;
189 /* A subroutine of btr_referenced_p, called through for_each_rtx.
190 PREG is a pointer to an rtx that is to be excluded from the
191 traversal. If we find a reference to a target register anywhere
192 else, return 1, and put a pointer to it into btr_reference_found. */
194 find_btr_reference (rtx
*px
, void *preg
)
203 if (overlaps_hard_reg_set_p (all_btrs
, GET_MODE (x
), REGNO (x
)))
205 btr_reference_found
= px
;
211 /* Return nonzero if X references (sets or reads) any branch target register.
212 If EXCLUDEP is set, disregard any references within the rtx pointed to
213 by it. If returning nonzero, also set btr_reference_found as above. */
215 btr_referenced_p (rtx x
, rtx
*excludep
)
217 return for_each_rtx (&x
, find_btr_reference
, excludep
);
220 /* Return true if insn is an instruction that sets a target register.
221 if CHECK_CONST is true, only return true if the source is constant.
222 If such a set is found and REGNO is nonzero, assign the register number
223 of the destination register to *REGNO. */
225 insn_sets_btr_p (const_rtx insn
, int check_const
, int *regno
)
229 if (NONJUMP_INSN_P (insn
)
230 && (set
= single_set (insn
)))
232 rtx dest
= SET_DEST (set
);
233 rtx src
= SET_SRC (set
);
235 if (GET_CODE (dest
) == SUBREG
)
236 dest
= XEXP (dest
, 0);
239 && TEST_HARD_REG_BIT (all_btrs
, REGNO (dest
)))
241 gcc_assert (!btr_referenced_p (src
, NULL
));
243 if (!check_const
|| CONSTANT_P (src
))
246 *regno
= REGNO (dest
);
254 /* Find and return a use of a target register within an instruction INSN. */
256 find_btr_use (rtx insn
)
258 return btr_referenced_p (insn
, NULL
) ? btr_reference_found
: NULL
;
261 /* Find the group that the target register definition DEF belongs
262 to in the list starting with *ALL_BTR_DEF_GROUPS. If no such
263 group exists, create one. Add def to the group. */
265 find_btr_def_group (btr_def_group
*all_btr_def_groups
, btr_def def
)
267 if (insn_sets_btr_p (def
->insn
, 1, NULL
))
269 btr_def_group this_group
;
270 rtx def_src
= SET_SRC (single_set (def
->insn
));
272 /* ?? This linear search is an efficiency concern, particularly
273 as the search will almost always fail to find a match. */
274 for (this_group
= *all_btr_def_groups
;
276 this_group
= this_group
->next
)
277 if (rtx_equal_p (def_src
, this_group
->src
))
282 this_group
= XOBNEW (&migrate_btrl_obstack
, struct btr_def_group_s
);
283 this_group
->src
= def_src
;
284 this_group
->members
= NULL
;
285 this_group
->next
= *all_btr_def_groups
;
286 *all_btr_def_groups
= this_group
;
288 def
->group
= this_group
;
289 def
->next_this_group
= this_group
->members
;
290 this_group
->members
= def
;
296 /* Create a new target register definition structure, for a definition in
297 block BB, instruction INSN, and insert it into ALL_BTR_DEFS. Return
298 the new definition. */
300 add_btr_def (fibheap_t all_btr_defs
, basic_block bb
, int insn_luid
, rtx insn
,
301 unsigned int dest_reg
, int other_btr_uses_before_def
,
302 btr_def_group
*all_btr_def_groups
)
304 btr_def this_def
= XOBNEW (&migrate_btrl_obstack
, struct btr_def_s
);
306 this_def
->luid
= insn_luid
;
307 this_def
->insn
= insn
;
308 this_def
->btr
= dest_reg
;
309 this_def
->cost
= basic_block_freq (bb
);
310 this_def
->has_ambiguous_use
= 0;
311 this_def
->other_btr_uses_before_def
= other_btr_uses_before_def
;
312 this_def
->other_btr_uses_after_use
= 0;
313 this_def
->next_this_bb
= NULL
;
314 this_def
->next_this_group
= NULL
;
315 this_def
->uses
= NULL
;
316 this_def
->live_range
= NULL
;
317 find_btr_def_group (all_btr_def_groups
, this_def
);
319 fibheap_insert (all_btr_defs
, -this_def
->cost
, this_def
);
323 "Found target reg definition: sets %u { bb %d, insn %d }%s priority %d\n",
324 dest_reg
, bb
->index
, INSN_UID (insn
),
325 (this_def
->group
? "" : ":not const"), this_def
->cost
);
330 /* Create a new target register user structure, for a use in block BB,
331 instruction INSN. Return the new user. */
333 new_btr_user (basic_block bb
, int insn_luid
, rtx insn
)
335 /* This instruction reads target registers. We need
336 to decide whether we can replace all target register
339 rtx
*usep
= find_btr_use (PATTERN (insn
));
341 btr_user user
= NULL
;
345 int unambiguous_single_use
;
347 /* We want to ensure that USE is the only use of a target
348 register in INSN, so that we know that to rewrite INSN to use
349 a different target register, all we have to do is replace USE. */
350 unambiguous_single_use
= !btr_referenced_p (PATTERN (insn
), usep
);
351 if (!unambiguous_single_use
)
354 use
= usep
? *usep
: NULL_RTX
;
355 user
= XOBNEW (&migrate_btrl_obstack
, struct btr_user_s
);
357 user
->luid
= insn_luid
;
360 user
->other_use_this_block
= 0;
362 user
->n_reaching_defs
= 0;
363 user
->first_reaching_def
= -1;
367 fprintf (dump_file
, "Uses target reg: { bb %d, insn %d }",
368 bb
->index
, INSN_UID (insn
));
371 fprintf (dump_file
, ": unambiguous use of reg %d\n",
378 /* Write the contents of S to the dump file. */
380 dump_hard_reg_set (HARD_REG_SET s
)
383 for (reg
= 0; reg
< FIRST_PSEUDO_REGISTER
; reg
++)
384 if (TEST_HARD_REG_BIT (s
, reg
))
385 fprintf (dump_file
, " %d", reg
);
388 /* Write the set of target regs live in block BB to the dump file. */
390 dump_btrs_live (int bb
)
392 fprintf (dump_file
, "BB%d live:", bb
);
393 dump_hard_reg_set (btrs_live
[bb
]);
394 fprintf (dump_file
, "\n");
397 /* REGNO is the number of a branch target register that is being used or
398 set. USERS_THIS_BB is a list of preceding branch target register users;
399 If any of them use the same register, set their other_use_this_block
402 note_other_use_this_block (unsigned int regno
, btr_user users_this_bb
)
406 for (user
= users_this_bb
; user
!= NULL
; user
= user
->next
)
407 if (user
->use
&& REGNO (user
->use
) == regno
)
408 user
->other_use_this_block
= 1;
412 btr_user users_this_bb
;
413 HARD_REG_SET btrs_written_in_block
;
414 HARD_REG_SET btrs_live_in_block
;
419 /* Called via note_stores or directly to register stores into /
420 clobbers of a branch target register DEST that are not recognized as
421 straightforward definitions. DATA points to information about the
422 current basic block that needs updating. */
424 note_btr_set (rtx dest
, const_rtx set ATTRIBUTE_UNUSED
, void *data
)
426 defs_uses_info
*info
= (defs_uses_info
*) data
;
427 int regno
, end_regno
;
431 regno
= REGNO (dest
);
432 end_regno
= END_HARD_REGNO (dest
);
433 for (; regno
< end_regno
; regno
++)
434 if (TEST_HARD_REG_BIT (all_btrs
, regno
))
436 note_other_use_this_block (regno
, info
->users_this_bb
);
437 SET_HARD_REG_BIT (info
->btrs_written_in_block
, regno
);
438 SET_HARD_REG_BIT (info
->btrs_live_in_block
, regno
);
439 sbitmap_difference (info
->bb_gen
, info
->bb_gen
,
440 info
->btr_defset
[regno
- first_btr
]);
445 compute_defs_uses_and_gen (fibheap_t all_btr_defs
, btr_def
*def_array
,
446 btr_user
*use_array
, sbitmap
*btr_defset
,
447 sbitmap
*bb_gen
, HARD_REG_SET
*btrs_written
)
449 /* Scan the code building up the set of all defs and all uses.
450 For each target register, build the set of defs of that register.
451 For each block, calculate the set of target registers
452 written in that block.
453 Also calculate the set of btrs ever live in that block.
457 btr_def_group all_btr_def_groups
= NULL
;
460 sbitmap_vector_zero (bb_gen
, last_basic_block
);
461 for (i
= NUM_FIXED_BLOCKS
; i
< last_basic_block
; i
++)
463 basic_block bb
= BASIC_BLOCK (i
);
465 btr_def defs_this_bb
= NULL
;
470 info
.users_this_bb
= NULL
;
471 info
.bb_gen
= bb_gen
[i
];
472 info
.btr_defset
= btr_defset
;
474 CLEAR_HARD_REG_SET (info
.btrs_live_in_block
);
475 CLEAR_HARD_REG_SET (info
.btrs_written_in_block
);
476 for (reg
= first_btr
; reg
<= last_btr
; reg
++)
477 if (TEST_HARD_REG_BIT (all_btrs
, reg
)
478 && REGNO_REG_SET_P (df_get_live_in (bb
), reg
))
479 SET_HARD_REG_BIT (info
.btrs_live_in_block
, reg
);
481 for (insn
= BB_HEAD (bb
), last
= NEXT_INSN (BB_END (bb
));
483 insn
= NEXT_INSN (insn
), insn_luid
++)
488 int insn_uid
= INSN_UID (insn
);
490 if (insn_sets_btr_p (insn
, 0, ®no
))
492 btr_def def
= add_btr_def (
493 all_btr_defs
, bb
, insn_luid
, insn
, regno
,
494 TEST_HARD_REG_BIT (info
.btrs_live_in_block
, regno
),
495 &all_btr_def_groups
);
497 def_array
[insn_uid
] = def
;
498 SET_HARD_REG_BIT (info
.btrs_written_in_block
, regno
);
499 SET_HARD_REG_BIT (info
.btrs_live_in_block
, regno
);
500 sbitmap_difference (bb_gen
[i
], bb_gen
[i
],
501 btr_defset
[regno
- first_btr
]);
502 SET_BIT (bb_gen
[i
], insn_uid
);
503 def
->next_this_bb
= defs_this_bb
;
505 SET_BIT (btr_defset
[regno
- first_btr
], insn_uid
);
506 note_other_use_this_block (regno
, info
.users_this_bb
);
508 /* Check for the blockage emitted by expand_nl_goto_receiver. */
509 else if (cfun
->has_nonlocal_label
510 && GET_CODE (PATTERN (insn
)) == UNSPEC_VOLATILE
)
514 /* Do the equivalent of calling note_other_use_this_block
515 for every target register. */
516 for (user
= info
.users_this_bb
; user
!= NULL
;
519 user
->other_use_this_block
= 1;
520 IOR_HARD_REG_SET (info
.btrs_written_in_block
, all_btrs
);
521 IOR_HARD_REG_SET (info
.btrs_live_in_block
, all_btrs
);
522 sbitmap_zero (info
.bb_gen
);
526 if (btr_referenced_p (PATTERN (insn
), NULL
))
528 btr_user user
= new_btr_user (bb
, insn_luid
, insn
);
530 use_array
[insn_uid
] = user
;
532 SET_HARD_REG_BIT (info
.btrs_live_in_block
,
537 for (reg
= first_btr
; reg
<= last_btr
; reg
++)
538 if (TEST_HARD_REG_BIT (all_btrs
, reg
)
539 && refers_to_regno_p (reg
, reg
+ 1, user
->insn
,
542 note_other_use_this_block (reg
,
544 SET_HARD_REG_BIT (info
.btrs_live_in_block
, reg
);
546 note_stores (PATTERN (insn
), note_btr_set
, &info
);
548 user
->next
= info
.users_this_bb
;
549 info
.users_this_bb
= user
;
553 HARD_REG_SET
*clobbered
= &call_used_reg_set
;
554 HARD_REG_SET call_saved
;
555 rtx pat
= PATTERN (insn
);
558 /* Check for sibcall. */
559 if (GET_CODE (pat
) == PARALLEL
)
560 for (i
= XVECLEN (pat
, 0) - 1; i
>= 0; i
--)
561 if (GET_CODE (XVECEXP (pat
, 0, i
)) == RETURN
)
563 COMPL_HARD_REG_SET (call_saved
,
565 clobbered
= &call_saved
;
568 for (regno
= first_btr
; regno
<= last_btr
; regno
++)
569 if (TEST_HARD_REG_BIT (*clobbered
, regno
))
570 note_btr_set (regno_reg_rtx
[regno
], NULL_RTX
, &info
);
576 COPY_HARD_REG_SET (btrs_live
[i
], info
.btrs_live_in_block
);
577 COPY_HARD_REG_SET (btrs_written
[i
], info
.btrs_written_in_block
);
579 REG_SET_TO_HARD_REG_SET (btrs_live_at_end
[i
], df_get_live_out (bb
));
580 /* If this block ends in a jump insn, add any uses or even clobbers
581 of branch target registers that it might have. */
582 for (insn
= BB_END (bb
); insn
!= BB_HEAD (bb
) && ! INSN_P (insn
); )
583 insn
= PREV_INSN (insn
);
584 /* ??? for the fall-through edge, it would make sense to insert the
585 btr set on the edge, but that would require to split the block
586 early on so that we can distinguish between dominance from the fall
587 through edge - which can use the call-clobbered registers - from
588 dominance by the throw edge. */
589 if (can_throw_internal (insn
))
593 COPY_HARD_REG_SET (tmp
, call_used_reg_set
);
594 AND_HARD_REG_SET (tmp
, all_btrs
);
595 IOR_HARD_REG_SET (btrs_live_at_end
[i
], tmp
);
598 if (can_throw
|| JUMP_P (insn
))
602 for (regno
= first_btr
; regno
<= last_btr
; regno
++)
603 if (refers_to_regno_p (regno
, regno
+1, insn
, NULL
))
604 SET_HARD_REG_BIT (btrs_live_at_end
[i
], regno
);
613 compute_kill (sbitmap
*bb_kill
, sbitmap
*btr_defset
,
614 HARD_REG_SET
*btrs_written
)
619 /* For each basic block, form the set BB_KILL - the set
620 of definitions that the block kills. */
621 sbitmap_vector_zero (bb_kill
, last_basic_block
);
622 for (i
= NUM_FIXED_BLOCKS
; i
< last_basic_block
; i
++)
624 for (regno
= first_btr
; regno
<= last_btr
; regno
++)
625 if (TEST_HARD_REG_BIT (all_btrs
, regno
)
626 && TEST_HARD_REG_BIT (btrs_written
[i
], regno
))
627 sbitmap_a_or_b (bb_kill
[i
], bb_kill
[i
],
628 btr_defset
[regno
- first_btr
]);
633 compute_out (sbitmap
*bb_out
, sbitmap
*bb_gen
, sbitmap
*bb_kill
, int max_uid
)
635 /* Perform iterative dataflow:
636 Initially, for all blocks, BB_OUT = BB_GEN.
638 BB_IN = union over predecessors of BB_OUT(pred)
639 BB_OUT = (BB_IN - BB_KILL) + BB_GEN
640 Iterate until the bb_out sets stop growing. */
643 sbitmap bb_in
= sbitmap_alloc (max_uid
);
645 for (i
= NUM_FIXED_BLOCKS
; i
< last_basic_block
; i
++)
646 sbitmap_copy (bb_out
[i
], bb_gen
[i
]);
652 for (i
= NUM_FIXED_BLOCKS
; i
< last_basic_block
; i
++)
654 sbitmap_union_of_preds (bb_in
, bb_out
, i
);
655 changed
|= sbitmap_union_of_diff_cg (bb_out
[i
], bb_gen
[i
],
659 sbitmap_free (bb_in
);
663 link_btr_uses (btr_def
*def_array
, btr_user
*use_array
, sbitmap
*bb_out
,
664 sbitmap
*btr_defset
, int max_uid
)
667 sbitmap reaching_defs
= sbitmap_alloc (max_uid
);
669 /* Link uses to the uses lists of all of their reaching defs.
670 Count up the number of reaching defs of each use. */
671 for (i
= NUM_FIXED_BLOCKS
; i
< last_basic_block
; i
++)
673 basic_block bb
= BASIC_BLOCK (i
);
677 sbitmap_union_of_preds (reaching_defs
, bb_out
, i
);
678 for (insn
= BB_HEAD (bb
), last
= NEXT_INSN (BB_END (bb
));
680 insn
= NEXT_INSN (insn
))
684 int insn_uid
= INSN_UID (insn
);
686 btr_def def
= def_array
[insn_uid
];
687 btr_user user
= use_array
[insn_uid
];
690 /* Remove all reaching defs of regno except
692 sbitmap_difference (reaching_defs
, reaching_defs
,
693 btr_defset
[def
->btr
- first_btr
]);
694 SET_BIT(reaching_defs
, insn_uid
);
699 /* Find all the reaching defs for this use. */
700 sbitmap reaching_defs_of_reg
= sbitmap_alloc(max_uid
);
701 unsigned int uid
= 0;
702 sbitmap_iterator sbi
;
706 reaching_defs_of_reg
,
708 btr_defset
[REGNO (user
->use
) - first_btr
]);
713 sbitmap_zero (reaching_defs_of_reg
);
714 for (reg
= first_btr
; reg
<= last_btr
; reg
++)
715 if (TEST_HARD_REG_BIT (all_btrs
, reg
)
716 && refers_to_regno_p (reg
, reg
+ 1, user
->insn
,
718 sbitmap_a_or_b_and_c (reaching_defs_of_reg
,
719 reaching_defs_of_reg
,
721 btr_defset
[reg
- first_btr
]);
723 EXECUTE_IF_SET_IN_SBITMAP (reaching_defs_of_reg
, 0, uid
, sbi
)
725 btr_def def
= def_array
[uid
];
727 /* We now know that def reaches user. */
731 "Def in insn %d reaches use in insn %d\n",
734 user
->n_reaching_defs
++;
736 def
->has_ambiguous_use
= 1;
737 if (user
->first_reaching_def
!= -1)
738 { /* There is more than one reaching def. This is
739 a rare case, so just give up on this def/use
740 web when it occurs. */
741 def
->has_ambiguous_use
= 1;
742 def_array
[user
->first_reaching_def
]
743 ->has_ambiguous_use
= 1;
746 "(use %d has multiple reaching defs)\n",
750 user
->first_reaching_def
= uid
;
751 if (user
->other_use_this_block
)
752 def
->other_btr_uses_after_use
= 1;
753 user
->next
= def
->uses
;
756 sbitmap_free (reaching_defs_of_reg
);
763 for (regno
= first_btr
; regno
<= last_btr
; regno
++)
764 if (TEST_HARD_REG_BIT (all_btrs
, regno
)
765 && TEST_HARD_REG_BIT (call_used_reg_set
, regno
))
766 sbitmap_difference (reaching_defs
, reaching_defs
,
767 btr_defset
[regno
- first_btr
]);
772 sbitmap_free (reaching_defs
);
776 build_btr_def_use_webs (fibheap_t all_btr_defs
)
778 const int max_uid
= get_max_uid ();
779 btr_def
*def_array
= XCNEWVEC (btr_def
, max_uid
);
780 btr_user
*use_array
= XCNEWVEC (btr_user
, max_uid
);
781 sbitmap
*btr_defset
= sbitmap_vector_alloc (
782 (last_btr
- first_btr
) + 1, max_uid
);
783 sbitmap
*bb_gen
= sbitmap_vector_alloc (last_basic_block
, max_uid
);
784 HARD_REG_SET
*btrs_written
= XCNEWVEC (HARD_REG_SET
, last_basic_block
);
788 sbitmap_vector_zero (btr_defset
, (last_btr
- first_btr
) + 1);
790 compute_defs_uses_and_gen (all_btr_defs
, def_array
, use_array
, btr_defset
,
791 bb_gen
, btrs_written
);
793 bb_kill
= sbitmap_vector_alloc (last_basic_block
, max_uid
);
794 compute_kill (bb_kill
, btr_defset
, btrs_written
);
797 bb_out
= sbitmap_vector_alloc (last_basic_block
, max_uid
);
798 compute_out (bb_out
, bb_gen
, bb_kill
, max_uid
);
800 sbitmap_vector_free (bb_gen
);
801 sbitmap_vector_free (bb_kill
);
803 link_btr_uses (def_array
, use_array
, bb_out
, btr_defset
, max_uid
);
805 sbitmap_vector_free (bb_out
);
806 sbitmap_vector_free (btr_defset
);
811 /* Return true if basic block BB contains the start or end of the
812 live range of the definition DEF, AND there are other live
813 ranges of the same target register that include BB. */
815 block_at_edge_of_live_range_p (int bb
, btr_def def
)
817 if (def
->other_btr_uses_before_def
&& BASIC_BLOCK (bb
) == def
->bb
)
819 else if (def
->other_btr_uses_after_use
)
822 for (user
= def
->uses
; user
!= NULL
; user
= user
->next
)
823 if (BASIC_BLOCK (bb
) == user
->bb
)
829 /* We are removing the def/use web DEF. The target register
830 used in this web is therefore no longer live in the live range
831 of this web, so remove it from the live set of all basic blocks
832 in the live range of the web.
833 Blocks at the boundary of the live range may contain other live
834 ranges for the same target register, so we have to be careful
835 to remove the target register from the live set of these blocks
836 only if they do not contain other live ranges for the same register. */
838 clear_btr_from_live_range (btr_def def
)
843 EXECUTE_IF_SET_IN_BITMAP (def
->live_range
, 0, bb
, bi
)
845 if ((!def
->other_btr_uses_before_def
846 && !def
->other_btr_uses_after_use
)
847 || !block_at_edge_of_live_range_p (bb
, def
))
849 CLEAR_HARD_REG_BIT (btrs_live
[bb
], def
->btr
);
850 CLEAR_HARD_REG_BIT (btrs_live_at_end
[bb
], def
->btr
);
856 CLEAR_HARD_REG_BIT (btrs_live_at_end
[def
->bb
->index
], def
->btr
);
860 /* We are adding the def/use web DEF. Add the target register used
861 in this web to the live set of all of the basic blocks that contain
862 the live range of the web.
863 If OWN_END is set, also show that the register is live from our
864 definitions at the end of the basic block where it is defined. */
866 add_btr_to_live_range (btr_def def
, int own_end
)
871 EXECUTE_IF_SET_IN_BITMAP (def
->live_range
, 0, bb
, bi
)
873 SET_HARD_REG_BIT (btrs_live
[bb
], def
->btr
);
874 SET_HARD_REG_BIT (btrs_live_at_end
[bb
], def
->btr
);
880 SET_HARD_REG_BIT (btrs_live_at_end
[def
->bb
->index
], def
->btr
);
885 /* Update a live range to contain the basic block NEW_BLOCK, and all
886 blocks on paths between the existing live range and NEW_BLOCK.
887 HEAD is a block contained in the existing live range that dominates
888 all other blocks in the existing live range.
889 Also add to the set BTRS_LIVE_IN_RANGE all target registers that
890 are live in the blocks that we add to the live range.
891 If FULL_RANGE is set, include the full live range of NEW_BB;
892 otherwise, if NEW_BB dominates HEAD_BB, only add registers that
893 are life at the end of NEW_BB for NEW_BB itself.
894 It is a precondition that either NEW_BLOCK dominates HEAD,or
895 HEAD dom NEW_BLOCK. This is used to speed up the
896 implementation of this function. */
898 augment_live_range (bitmap live_range
, HARD_REG_SET
*btrs_live_in_range
,
899 basic_block head_bb
, basic_block new_bb
, int full_range
)
901 basic_block
*worklist
, *tos
;
903 tos
= worklist
= XNEWVEC (basic_block
, n_basic_blocks
+ 1);
905 if (dominated_by_p (CDI_DOMINATORS
, new_bb
, head_bb
))
907 if (new_bb
== head_bb
)
910 IOR_HARD_REG_SET (*btrs_live_in_range
, btrs_live
[new_bb
->index
]);
920 int new_block
= new_bb
->index
;
922 gcc_assert (dominated_by_p (CDI_DOMINATORS
, head_bb
, new_bb
));
924 IOR_HARD_REG_SET (*btrs_live_in_range
, btrs_live
[head_bb
->index
]);
925 bitmap_set_bit (live_range
, new_block
);
926 /* A previous btr migration could have caused a register to be
927 live just at the end of new_block which we need in full, so
928 use trs_live_at_end even if full_range is set. */
929 IOR_HARD_REG_SET (*btrs_live_in_range
, btrs_live_at_end
[new_block
]);
931 IOR_HARD_REG_SET (*btrs_live_in_range
, btrs_live
[new_block
]);
935 "Adding end of block %d and rest of %d to live range\n",
936 new_block
, head_bb
->index
);
937 fprintf (dump_file
,"Now live btrs are ");
938 dump_hard_reg_set (*btrs_live_in_range
);
939 fprintf (dump_file
, "\n");
941 FOR_EACH_EDGE (e
, ei
, head_bb
->preds
)
945 while (tos
!= worklist
)
947 basic_block bb
= *--tos
;
948 if (!bitmap_bit_p (live_range
, bb
->index
))
953 bitmap_set_bit (live_range
, bb
->index
);
954 IOR_HARD_REG_SET (*btrs_live_in_range
,
955 btrs_live
[bb
->index
]);
956 /* A previous btr migration could have caused a register to be
957 live just at the end of a block which we need in full. */
958 IOR_HARD_REG_SET (*btrs_live_in_range
,
959 btrs_live_at_end
[bb
->index
]);
963 "Adding block %d to live range\n", bb
->index
);
964 fprintf (dump_file
,"Now live btrs are ");
965 dump_hard_reg_set (*btrs_live_in_range
);
966 fprintf (dump_file
, "\n");
969 FOR_EACH_EDGE (e
, ei
, bb
->preds
)
971 basic_block pred
= e
->src
;
972 if (!bitmap_bit_p (live_range
, pred
->index
))
981 /* Return the most desirable target register that is not in
982 the set USED_BTRS. */
984 choose_btr (HARD_REG_SET used_btrs
)
988 if (!hard_reg_set_subset_p (all_btrs
, used_btrs
))
989 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; i
++)
991 #ifdef REG_ALLOC_ORDER
992 int regno
= reg_alloc_order
[i
];
996 if (TEST_HARD_REG_BIT (all_btrs
, regno
)
997 && !TEST_HARD_REG_BIT (used_btrs
, regno
))
1003 /* Calculate the set of basic blocks that contain the live range of
1004 the def/use web DEF.
1005 Also calculate the set of target registers that are live at time
1006 in this live range, but ignore the live range represented by DEF
1007 when calculating this set. */
1009 btr_def_live_range (btr_def def
, HARD_REG_SET
*btrs_live_in_range
)
1011 if (!def
->live_range
)
1015 def
->live_range
= BITMAP_ALLOC (NULL
);
1017 bitmap_set_bit (def
->live_range
, def
->bb
->index
);
1018 COPY_HARD_REG_SET (*btrs_live_in_range
,
1019 (flag_btr_bb_exclusive
1020 ? btrs_live
: btrs_live_at_end
)[def
->bb
->index
]);
1022 for (user
= def
->uses
; user
!= NULL
; user
= user
->next
)
1023 augment_live_range (def
->live_range
, btrs_live_in_range
,
1025 (flag_btr_bb_exclusive
1026 || user
->insn
!= BB_END (def
->bb
)
1027 || !JUMP_P (user
->insn
)));
1031 /* def->live_range is accurate, but we need to recompute
1032 the set of target registers live over it, because migration
1033 of other PT instructions may have affected it.
1036 unsigned def_bb
= flag_btr_bb_exclusive
? -1 : def
->bb
->index
;
1039 CLEAR_HARD_REG_SET (*btrs_live_in_range
);
1040 EXECUTE_IF_SET_IN_BITMAP (def
->live_range
, 0, bb
, bi
)
1042 IOR_HARD_REG_SET (*btrs_live_in_range
,
1044 ? btrs_live_at_end
: btrs_live
) [bb
]);
1047 if (!def
->other_btr_uses_before_def
&&
1048 !def
->other_btr_uses_after_use
)
1049 CLEAR_HARD_REG_BIT (*btrs_live_in_range
, def
->btr
);
1052 /* Merge into the def/use web DEF any other def/use webs in the same
1053 group that are dominated by DEF, provided that there is a target
1054 register available to allocate to the merged web. */
1056 combine_btr_defs (btr_def def
, HARD_REG_SET
*btrs_live_in_range
)
1060 for (other_def
= def
->group
->members
;
1062 other_def
= other_def
->next_this_group
)
1064 if (other_def
!= def
1065 && other_def
->uses
!= NULL
1066 && ! other_def
->has_ambiguous_use
1067 && dominated_by_p (CDI_DOMINATORS
, other_def
->bb
, def
->bb
))
1069 /* def->bb dominates the other def, so def and other_def could
1071 /* Merge their live ranges, and get the set of
1072 target registers live over the merged range. */
1074 HARD_REG_SET combined_btrs_live
;
1075 bitmap combined_live_range
= BITMAP_ALLOC (NULL
);
1078 if (other_def
->live_range
== NULL
)
1080 HARD_REG_SET dummy_btrs_live_in_range
;
1081 btr_def_live_range (other_def
, &dummy_btrs_live_in_range
);
1083 COPY_HARD_REG_SET (combined_btrs_live
, *btrs_live_in_range
);
1084 bitmap_copy (combined_live_range
, def
->live_range
);
1086 for (user
= other_def
->uses
; user
!= NULL
; user
= user
->next
)
1087 augment_live_range (combined_live_range
, &combined_btrs_live
,
1089 (flag_btr_bb_exclusive
1090 || user
->insn
!= BB_END (def
->bb
)
1091 || !JUMP_P (user
->insn
)));
1093 btr
= choose_btr (combined_btrs_live
);
1096 /* We can combine them. */
1099 "Combining def in insn %d with def in insn %d\n",
1100 INSN_UID (other_def
->insn
), INSN_UID (def
->insn
));
1103 user
= other_def
->uses
;
1104 while (user
!= NULL
)
1106 btr_user next
= user
->next
;
1108 user
->next
= def
->uses
;
1112 /* Combining def/use webs can make target registers live
1113 after uses where they previously were not. This means
1114 some REG_DEAD notes may no longer be correct. We could
1115 be more precise about this if we looked at the combined
1116 live range, but here I just delete any REG_DEAD notes
1117 in case they are no longer correct. */
1118 for (user
= def
->uses
; user
!= NULL
; user
= user
->next
)
1119 remove_note (user
->insn
,
1120 find_regno_note (user
->insn
, REG_DEAD
,
1121 REGNO (user
->use
)));
1122 clear_btr_from_live_range (other_def
);
1123 other_def
->uses
= NULL
;
1124 bitmap_copy (def
->live_range
, combined_live_range
);
1125 if (other_def
->btr
== btr
&& other_def
->other_btr_uses_after_use
)
1126 def
->other_btr_uses_after_use
= 1;
1127 COPY_HARD_REG_SET (*btrs_live_in_range
, combined_btrs_live
);
1129 /* Delete the old target register initialization. */
1130 delete_insn (other_def
->insn
);
1133 BITMAP_FREE (combined_live_range
);
1138 /* Move the definition DEF from its current position to basic
1139 block NEW_DEF_BB, and modify it to use branch target register BTR.
1140 Delete the old defining insn, and insert a new one in NEW_DEF_BB.
1141 Update all reaching uses of DEF in the RTL to use BTR.
1142 If this new position means that other defs in the
1143 same group can be combined with DEF then combine them. */
1145 move_btr_def (basic_block new_def_bb
, int btr
, btr_def def
, bitmap live_range
,
1146 HARD_REG_SET
*btrs_live_in_range
)
1148 /* We can move the instruction.
1149 Set a target register in block NEW_DEF_BB to the value
1150 needed for this target register definition.
1151 Replace all uses of the old target register definition by
1152 uses of the new definition. Delete the old definition. */
1153 basic_block b
= new_def_bb
;
1154 rtx insp
= BB_HEAD (b
);
1155 rtx old_insn
= def
->insn
;
1159 enum machine_mode btr_mode
;
1164 fprintf(dump_file
, "migrating to basic block %d, using reg %d\n",
1165 new_def_bb
->index
, btr
);
1167 clear_btr_from_live_range (def
);
1169 def
->bb
= new_def_bb
;
1171 def
->cost
= basic_block_freq (new_def_bb
);
1172 bitmap_copy (def
->live_range
, live_range
);
1173 combine_btr_defs (def
, btrs_live_in_range
);
1175 def
->other_btr_uses_before_def
1176 = TEST_HARD_REG_BIT (btrs_live
[b
->index
], btr
) ? 1 : 0;
1177 add_btr_to_live_range (def
, 1);
1179 insp
= NEXT_INSN (insp
);
1180 /* N.B.: insp is expected to be NOTE_INSN_BASIC_BLOCK now. Some
1181 optimizations can result in insp being both first and last insn of
1183 /* ?? some assertions to check that insp is sensible? */
1185 if (def
->other_btr_uses_before_def
)
1188 for (insp
= BB_END (b
); ! INSN_P (insp
); insp
= PREV_INSN (insp
))
1189 gcc_assert (insp
!= BB_HEAD (b
));
1191 if (JUMP_P (insp
) || can_throw_internal (insp
))
1192 insp
= PREV_INSN (insp
);
1195 set
= single_set (old_insn
);
1196 src
= SET_SRC (set
);
1197 btr_mode
= GET_MODE (SET_DEST (set
));
1198 btr_rtx
= gen_rtx_REG (btr_mode
, btr
);
1200 new_insn
= gen_move_insn (btr_rtx
, src
);
1202 /* Insert target register initialization at head of basic block. */
1203 def
->insn
= emit_insn_after (new_insn
, insp
);
1205 df_set_regs_ever_live (btr
, true);
1208 fprintf (dump_file
, "New pt is insn %d, inserted after insn %d\n",
1209 INSN_UID (def
->insn
), INSN_UID (insp
));
1211 /* Delete the old target register initialization. */
1212 delete_insn (old_insn
);
1214 /* Replace each use of the old target register by a use of the new target
1216 for (user
= def
->uses
; user
!= NULL
; user
= user
->next
)
1218 /* Some extra work here to ensure consistent modes, because
1219 it seems that a target register REG rtx can be given a different
1220 mode depending on the context (surely that should not be
1222 rtx replacement_rtx
;
1223 if (GET_MODE (user
->use
) == GET_MODE (btr_rtx
)
1224 || GET_MODE (user
->use
) == VOIDmode
)
1225 replacement_rtx
= btr_rtx
;
1227 replacement_rtx
= gen_rtx_REG (GET_MODE (user
->use
), btr
);
1228 validate_replace_rtx (user
->use
, replacement_rtx
, user
->insn
);
1229 user
->use
= replacement_rtx
;
1233 /* We anticipate intra-block scheduling to be done. See if INSN could move
1234 up within BB by N_INSNS. */
1236 can_move_up (const_basic_block bb
, const_rtx insn
, int n_insns
)
1238 while (insn
!= BB_HEAD (bb
) && n_insns
> 0)
1240 insn
= PREV_INSN (insn
);
1241 /* ??? What if we have an anti-dependency that actually prevents the
1242 scheduler from doing the move? We'd like to re-allocate the register,
1243 but not necessarily put the load into another basic block. */
1247 return n_insns
<= 0;
1250 /* Attempt to migrate the target register definition DEF to an
1251 earlier point in the flowgraph.
1253 It is a precondition of this function that DEF is migratable:
1254 i.e. it has a constant source, and all uses are unambiguous.
1256 Only migrations that reduce the cost of DEF will be made.
1257 MIN_COST is the lower bound on the cost of the DEF after migration.
1258 If we migrate DEF so that its cost falls below MIN_COST,
1259 then we do not attempt to migrate further. The idea is that
1260 we migrate definitions in a priority order based on their cost,
1261 when the cost of this definition falls below MIN_COST, then
1262 there is another definition with cost == MIN_COST which now
1263 has a higher priority than this definition.
1265 Return nonzero if there may be benefit from attempting to
1266 migrate this DEF further (i.e. we have reduced the cost below
1267 MIN_COST, but we may be able to reduce it further).
1268 Return zero if no further migration is possible. */
1270 migrate_btr_def (btr_def def
, int min_cost
)
1273 HARD_REG_SET btrs_live_in_range
;
1274 int btr_used_near_def
= 0;
1275 int def_basic_block_freq
;
1276 basic_block attempt
;
1284 "Attempting to migrate pt from insn %d (cost = %d, min_cost = %d) ... ",
1285 INSN_UID (def
->insn
), def
->cost
, min_cost
);
1287 if (!def
->group
|| def
->has_ambiguous_use
)
1288 /* These defs are not migratable. */
1291 fprintf (dump_file
, "it's not migratable\n");
1296 /* We have combined this def with another in the same group, so
1297 no need to consider it further.
1301 fprintf (dump_file
, "it's already combined with another pt\n");
1305 btr_def_live_range (def
, &btrs_live_in_range
);
1306 live_range
= BITMAP_ALLOC (NULL
);
1307 bitmap_copy (live_range
, def
->live_range
);
1309 #ifdef INSN_SCHEDULING
1310 def_latency
= insn_default_latency (def
->insn
) * issue_rate
;
1312 def_latency
= issue_rate
;
1315 for (user
= def
->uses
; user
!= NULL
; user
= user
->next
)
1317 if (user
->bb
== def
->bb
1318 && user
->luid
> def
->luid
1319 && (def
->luid
+ def_latency
) > user
->luid
1320 && ! can_move_up (def
->bb
, def
->insn
,
1321 (def
->luid
+ def_latency
) - user
->luid
))
1323 btr_used_near_def
= 1;
1328 def_basic_block_freq
= basic_block_freq (def
->bb
);
1330 for (attempt
= get_immediate_dominator (CDI_DOMINATORS
, def
->bb
);
1331 !give_up
&& attempt
&& attempt
!= ENTRY_BLOCK_PTR
&& def
->cost
>= min_cost
;
1332 attempt
= get_immediate_dominator (CDI_DOMINATORS
, attempt
))
1334 /* Try to move the instruction that sets the target register into
1335 basic block ATTEMPT. */
1336 int try_freq
= basic_block_freq (attempt
);
1340 /* If ATTEMPT has abnormal edges, skip it. */
1341 FOR_EACH_EDGE (e
, ei
, attempt
->succs
)
1342 if (e
->flags
& EDGE_COMPLEX
)
1348 fprintf (dump_file
, "trying block %d ...", attempt
->index
);
1350 if (try_freq
< def_basic_block_freq
1351 || (try_freq
== def_basic_block_freq
&& btr_used_near_def
))
1354 augment_live_range (live_range
, &btrs_live_in_range
, def
->bb
, attempt
,
1355 flag_btr_bb_exclusive
);
1358 fprintf (dump_file
, "Now btrs live in range are: ");
1359 dump_hard_reg_set (btrs_live_in_range
);
1360 fprintf (dump_file
, "\n");
1362 btr
= choose_btr (btrs_live_in_range
);
1365 move_btr_def (attempt
, btr
, def
, live_range
, &btrs_live_in_range
);
1366 bitmap_copy(live_range
, def
->live_range
);
1367 btr_used_near_def
= 0;
1369 def_basic_block_freq
= basic_block_freq (def
->bb
);
1373 /* There are no free target registers available to move
1374 this far forward, so give up */
1378 "giving up because there are no free target registers\n");
1387 fprintf (dump_file
, "failed to move\n");
1389 BITMAP_FREE (live_range
);
1393 /* Attempt to move instructions that set target registers earlier
1394 in the flowgraph, away from their corresponding uses. */
1396 migrate_btr_defs (enum reg_class btr_class
, int allow_callee_save
)
1398 fibheap_t all_btr_defs
= fibheap_new ();
1401 gcc_obstack_init (&migrate_btrl_obstack
);
1406 for (i
= NUM_FIXED_BLOCKS
; i
< last_basic_block
; i
++)
1408 basic_block bb
= BASIC_BLOCK (i
);
1410 "Basic block %d: count = " HOST_WIDEST_INT_PRINT_DEC
1411 " loop-depth = %d idom = %d\n",
1412 i
, (HOST_WIDEST_INT
) bb
->count
, bb
->loop_depth
,
1413 get_immediate_dominator (CDI_DOMINATORS
, bb
)->index
);
1417 CLEAR_HARD_REG_SET (all_btrs
);
1418 for (first_btr
= -1, reg
= 0; reg
< FIRST_PSEUDO_REGISTER
; reg
++)
1419 if (TEST_HARD_REG_BIT (reg_class_contents
[(int) btr_class
], reg
)
1420 && (allow_callee_save
|| call_used_regs
[reg
]
1421 || df_regs_ever_live_p (reg
)))
1423 SET_HARD_REG_BIT (all_btrs
, reg
);
1429 btrs_live
= XCNEWVEC (HARD_REG_SET
, last_basic_block
);
1430 btrs_live_at_end
= XCNEWVEC (HARD_REG_SET
, last_basic_block
);
1432 build_btr_def_use_webs (all_btr_defs
);
1434 while (!fibheap_empty (all_btr_defs
))
1436 btr_def def
= (btr_def
) fibheap_extract_min (all_btr_defs
);
1437 int min_cost
= -fibheap_min_key (all_btr_defs
);
1438 if (migrate_btr_def (def
, min_cost
))
1440 fibheap_insert (all_btr_defs
, -def
->cost
, (void *) def
);
1444 "Putting insn %d back on queue with priority %d\n",
1445 INSN_UID (def
->insn
), def
->cost
);
1449 BITMAP_FREE (def
->live_range
);
1453 free (btrs_live_at_end
);
1454 obstack_free (&migrate_btrl_obstack
, NULL
);
1455 fibheap_delete (all_btr_defs
);
1459 branch_target_load_optimize (bool after_prologue_epilogue_gen
)
1461 enum reg_class klass
1462 = (enum reg_class
) targetm
.branch_target_register_class ();
1463 if (klass
!= NO_REGS
)
1465 /* Initialize issue_rate. */
1466 if (targetm
.sched
.issue_rate
)
1467 issue_rate
= targetm
.sched
.issue_rate ();
1471 if (!after_prologue_epilogue_gen
)
1473 /* Build the CFG for migrate_btr_defs. */
1475 /* This may or may not be needed, depending on where we
1477 cleanup_cfg (optimize
? CLEANUP_EXPENSIVE
: 0);
1483 /* Dominator info is also needed for migrate_btr_def. */
1484 calculate_dominance_info (CDI_DOMINATORS
);
1485 migrate_btr_defs (klass
,
1486 (targetm
.branch_target_register_callee_saved
1487 (after_prologue_epilogue_gen
)));
1489 free_dominance_info (CDI_DOMINATORS
);
1494 gate_handle_branch_target_load_optimize1 (void)
1496 return flag_branch_target_load_optimize
;
1501 rest_of_handle_branch_target_load_optimize1 (void)
1503 branch_target_load_optimize (epilogue_completed
);
1507 struct rtl_opt_pass pass_branch_target_load_optimize1
=
1512 gate_handle_branch_target_load_optimize1
, /* gate */
1513 rest_of_handle_branch_target_load_optimize1
, /* execute */
1516 0, /* static_pass_number */
1517 TV_NONE
, /* tv_id */
1518 0, /* properties_required */
1519 0, /* properties_provided */
1520 0, /* properties_destroyed */
1521 0, /* todo_flags_start */
1522 TODO_verify_rtl_sharing
|
1523 TODO_ggc_collect
, /* todo_flags_finish */
1528 gate_handle_branch_target_load_optimize2 (void)
1530 return (optimize
> 0 && flag_branch_target_load_optimize2
);
1535 rest_of_handle_branch_target_load_optimize2 (void)
1537 static int warned
= 0;
1539 /* Leave this a warning for now so that it is possible to experiment
1540 with running this pass twice. In 3.6, we should either make this
1541 an error, or use separate dump files. */
1542 if (flag_branch_target_load_optimize
1543 && flag_branch_target_load_optimize2
1546 warning (0, "branch target register load optimization is not intended "
1552 branch_target_load_optimize (epilogue_completed
);
1556 struct rtl_opt_pass pass_branch_target_load_optimize2
=
1561 gate_handle_branch_target_load_optimize2
, /* gate */
1562 rest_of_handle_branch_target_load_optimize2
, /* execute */
1565 0, /* static_pass_number */
1566 TV_NONE
, /* tv_id */
1567 0, /* properties_required */
1568 0, /* properties_provided */
1569 0, /* properties_destroyed */
1570 0, /* todo_flags_start */
1571 TODO_ggc_collect
, /* todo_flags_finish */