1 /* RTL-level loop invariant motion.
2 Copyright (C) 2004-2014 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 the
8 Free Software Foundation; either version 3, or (at your option) any
11 GCC is distributed in the hope that it will be useful, but WITHOUT
12 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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/>. */
20 /* This implements the loop invariant motion pass. It is very simple
21 (no calls, no loads/stores, etc.). This should be sufficient to cleanup
22 things like address arithmetics -- other more complicated invariants should
23 be eliminated on GIMPLE either in tree-ssa-loop-im.c or in tree-ssa-pre.c.
25 We proceed loop by loop -- it is simpler than trying to handle things
26 globally and should not lose much. First we inspect all sets inside loop
27 and create a dependency graph on insns (saying "to move this insn, you must
28 also move the following insns").
30 We then need to determine what to move. We estimate the number of registers
31 used and move as many invariants as possible while we still have enough free
32 registers. We prefer the expensive invariants.
34 Then we move the selected invariants out of the loop, creating a new
35 temporaries for them if necessary. */
39 #include "coretypes.h"
41 #include "hard-reg-set.h"
45 #include "basic-block.h"
53 #include "hash-table.h"
60 /* The data stored for the loop. */
64 struct loop
*outermost_exit
; /* The outermost exit of the loop. */
65 bool has_call
; /* True if the loop contains a call. */
66 /* Maximal register pressure inside loop for given register class
67 (defined only for the pressure classes). */
68 int max_reg_pressure
[N_REG_CLASSES
];
69 /* Loop regs referenced and live pseudo-registers. */
71 bitmap_head regs_live
;
74 #define LOOP_DATA(LOOP) ((struct loop_data *) (LOOP)->aux)
76 /* The description of an use. */
80 rtx
*pos
; /* Position of the use. */
81 rtx insn
; /* The insn in that the use occurs. */
82 unsigned addr_use_p
; /* Whether the use occurs in an address. */
83 struct use
*next
; /* Next use in the list. */
86 /* The description of a def. */
90 struct use
*uses
; /* The list of uses that are uniquely reached
92 unsigned n_uses
; /* Number of such uses. */
93 unsigned n_addr_uses
; /* Number of uses in addresses. */
94 unsigned invno
; /* The corresponding invariant. */
97 /* The data stored for each invariant. */
101 /* The number of the invariant. */
104 /* The number of the invariant with the same value. */
107 /* If we moved the invariant out of the loop, the register that contains its
111 /* If we moved the invariant out of the loop, the original regno
112 that contained its value. */
115 /* The definition of the invariant. */
118 /* The insn in that it is defined. */
121 /* Whether it is always executed. */
122 bool always_executed
;
124 /* Whether to move the invariant. */
127 /* Whether the invariant is cheap when used as an address. */
130 /* Cost of the invariant. */
133 /* The invariants it depends on. */
136 /* Used for detecting already visited invariants during determining
137 costs of movements. */
141 /* Currently processed loop. */
142 static struct loop
*curr_loop
;
144 /* Table of invariants indexed by the df_ref uid field. */
146 static unsigned int invariant_table_size
= 0;
147 static struct invariant
** invariant_table
;
149 /* Entry for hash table of invariant expressions. */
151 struct invariant_expr_entry
154 struct invariant
*inv
;
160 enum machine_mode mode
;
166 /* The actual stamp for marking already visited invariants during determining
167 costs of movements. */
169 static unsigned actual_stamp
;
171 typedef struct invariant
*invariant_p
;
174 /* The invariants. */
176 static vec
<invariant_p
> invariants
;
178 /* Check the size of the invariant table and realloc if necessary. */
181 check_invariant_table_size (void)
183 if (invariant_table_size
< DF_DEFS_TABLE_SIZE ())
185 unsigned int new_size
= DF_DEFS_TABLE_SIZE () + (DF_DEFS_TABLE_SIZE () / 4);
186 invariant_table
= XRESIZEVEC (struct invariant
*, invariant_table
, new_size
);
187 memset (&invariant_table
[invariant_table_size
], 0,
188 (new_size
- invariant_table_size
) * sizeof (struct invariant
*));
189 invariant_table_size
= new_size
;
193 /* Test for possibility of invariantness of X. */
196 check_maybe_invariant (rtx x
)
198 enum rtx_code code
= GET_CODE (x
);
212 case UNSPEC_VOLATILE
:
220 /* Load/store motion is done elsewhere. ??? Perhaps also add it here?
221 It should not be hard, and might be faster than "elsewhere". */
223 /* Just handle the most trivial case where we load from an unchanging
224 location (most importantly, pic tables). */
225 if (MEM_READONLY_P (x
) && !MEM_VOLATILE_P (x
))
231 /* Don't mess with insns declared volatile. */
232 if (MEM_VOLATILE_P (x
))
240 fmt
= GET_RTX_FORMAT (code
);
241 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
245 if (!check_maybe_invariant (XEXP (x
, i
)))
248 else if (fmt
[i
] == 'E')
250 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
251 if (!check_maybe_invariant (XVECEXP (x
, i
, j
)))
259 /* Returns the invariant definition for USE, or NULL if USE is not
262 static struct invariant
*
263 invariant_for_use (df_ref use
)
265 struct df_link
*defs
;
267 basic_block bb
= DF_REF_BB (use
), def_bb
;
269 if (DF_REF_FLAGS (use
) & DF_REF_READ_WRITE
)
272 defs
= DF_REF_CHAIN (use
);
273 if (!defs
|| defs
->next
)
276 check_invariant_table_size ();
277 if (!invariant_table
[DF_REF_ID (def
)])
280 def_bb
= DF_REF_BB (def
);
281 if (!dominated_by_p (CDI_DOMINATORS
, bb
, def_bb
))
283 return invariant_table
[DF_REF_ID (def
)];
286 /* Computes hash value for invariant expression X in INSN. */
289 hash_invariant_expr_1 (rtx insn
, rtx x
)
291 enum rtx_code code
= GET_CODE (x
);
294 hashval_t val
= code
;
297 struct invariant
*inv
;
305 return hash_rtx (x
, GET_MODE (x
), &do_not_record_p
, NULL
, false);
308 use
= df_find_use (insn
, x
);
310 return hash_rtx (x
, GET_MODE (x
), &do_not_record_p
, NULL
, false);
311 inv
= invariant_for_use (use
);
313 return hash_rtx (x
, GET_MODE (x
), &do_not_record_p
, NULL
, false);
315 gcc_assert (inv
->eqto
!= ~0u);
322 fmt
= GET_RTX_FORMAT (code
);
323 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
326 val
^= hash_invariant_expr_1 (insn
, XEXP (x
, i
));
327 else if (fmt
[i
] == 'E')
329 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
330 val
^= hash_invariant_expr_1 (insn
, XVECEXP (x
, i
, j
));
332 else if (fmt
[i
] == 'i' || fmt
[i
] == 'n')
339 /* Returns true if the invariant expressions E1 and E2 used in insns INSN1
340 and INSN2 have always the same value. */
343 invariant_expr_equal_p (rtx insn1
, rtx e1
, rtx insn2
, rtx e2
)
345 enum rtx_code code
= GET_CODE (e1
);
349 struct invariant
*inv1
= NULL
, *inv2
= NULL
;
352 /* If mode of only one of the operands is VOIDmode, it is not equivalent to
353 the other one. If both are VOIDmode, we rely on the caller of this
354 function to verify that their modes are the same. */
355 if (code
!= GET_CODE (e2
) || GET_MODE (e1
) != GET_MODE (e2
))
364 return rtx_equal_p (e1
, e2
);
367 use1
= df_find_use (insn1
, e1
);
368 use2
= df_find_use (insn2
, e2
);
370 inv1
= invariant_for_use (use1
);
372 inv2
= invariant_for_use (use2
);
375 return rtx_equal_p (e1
, e2
);
380 gcc_assert (inv1
->eqto
!= ~0u);
381 gcc_assert (inv2
->eqto
!= ~0u);
382 return inv1
->eqto
== inv2
->eqto
;
388 fmt
= GET_RTX_FORMAT (code
);
389 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
396 if (!invariant_expr_equal_p (insn1
, sub1
, insn2
, sub2
))
400 else if (fmt
[i
] == 'E')
402 if (XVECLEN (e1
, i
) != XVECLEN (e2
, i
))
405 for (j
= 0; j
< XVECLEN (e1
, i
); j
++)
407 sub1
= XVECEXP (e1
, i
, j
);
408 sub2
= XVECEXP (e2
, i
, j
);
410 if (!invariant_expr_equal_p (insn1
, sub1
, insn2
, sub2
))
414 else if (fmt
[i
] == 'i' || fmt
[i
] == 'n')
416 if (XINT (e1
, i
) != XINT (e2
, i
))
419 /* Unhandled type of subexpression, we fail conservatively. */
427 struct invariant_expr_hasher
: typed_free_remove
<invariant_expr_entry
>
429 typedef invariant_expr_entry value_type
;
430 typedef invariant_expr_entry compare_type
;
431 static inline hashval_t
hash (const value_type
*);
432 static inline bool equal (const value_type
*, const compare_type
*);
435 /* Returns hash value for invariant expression entry ENTRY. */
438 invariant_expr_hasher::hash (const value_type
*entry
)
443 /* Compares invariant expression entries ENTRY1 and ENTRY2. */
446 invariant_expr_hasher::equal (const value_type
*entry1
,
447 const compare_type
*entry2
)
449 if (entry1
->mode
!= entry2
->mode
)
452 return invariant_expr_equal_p (entry1
->inv
->insn
, entry1
->expr
,
453 entry2
->inv
->insn
, entry2
->expr
);
456 typedef hash_table
<invariant_expr_hasher
> invariant_htab_type
;
458 /* Checks whether invariant with value EXPR in machine mode MODE is
459 recorded in EQ. If this is the case, return the invariant. Otherwise
460 insert INV to the table for this expression and return INV. */
462 static struct invariant
*
463 find_or_insert_inv (invariant_htab_type eq
, rtx expr
, enum machine_mode mode
,
464 struct invariant
*inv
)
466 hashval_t hash
= hash_invariant_expr_1 (inv
->insn
, expr
);
467 struct invariant_expr_entry
*entry
;
468 struct invariant_expr_entry pentry
;
469 invariant_expr_entry
**slot
;
474 slot
= eq
.find_slot_with_hash (&pentry
, hash
, INSERT
);
480 entry
= XNEW (struct invariant_expr_entry
);
490 /* Finds invariants identical to INV and records the equivalence. EQ is the
491 hash table of the invariants. */
494 find_identical_invariants (invariant_htab_type eq
, struct invariant
*inv
)
498 struct invariant
*dep
;
500 enum machine_mode mode
;
502 if (inv
->eqto
!= ~0u)
505 EXECUTE_IF_SET_IN_BITMAP (inv
->depends_on
, 0, depno
, bi
)
507 dep
= invariants
[depno
];
508 find_identical_invariants (eq
, dep
);
511 set
= single_set (inv
->insn
);
512 expr
= SET_SRC (set
);
513 mode
= GET_MODE (expr
);
514 if (mode
== VOIDmode
)
515 mode
= GET_MODE (SET_DEST (set
));
516 inv
->eqto
= find_or_insert_inv (eq
, expr
, mode
, inv
)->invno
;
518 if (dump_file
&& inv
->eqto
!= inv
->invno
)
520 "Invariant %d is equivalent to invariant %d.\n",
521 inv
->invno
, inv
->eqto
);
524 /* Find invariants with the same value and record the equivalences. */
527 merge_identical_invariants (void)
530 struct invariant
*inv
;
531 invariant_htab_type eq
;
532 eq
.create (invariants
.length ());
534 FOR_EACH_VEC_ELT (invariants
, i
, inv
)
535 find_identical_invariants (eq
, inv
);
540 /* Determines the basic blocks inside LOOP that are always executed and
541 stores their bitmap to ALWAYS_REACHED. MAY_EXIT is a bitmap of
542 basic blocks that may either exit the loop, or contain the call that
543 does not have to return. BODY is body of the loop obtained by
544 get_loop_body_in_dom_order. */
547 compute_always_reached (struct loop
*loop
, basic_block
*body
,
548 bitmap may_exit
, bitmap always_reached
)
552 for (i
= 0; i
< loop
->num_nodes
; i
++)
554 if (dominated_by_p (CDI_DOMINATORS
, loop
->latch
, body
[i
]))
555 bitmap_set_bit (always_reached
, i
);
557 if (bitmap_bit_p (may_exit
, i
))
562 /* Finds exits out of the LOOP with body BODY. Marks blocks in that we may
563 exit the loop by cfg edge to HAS_EXIT and MAY_EXIT. In MAY_EXIT
564 additionally mark blocks that may exit due to a call. */
567 find_exits (struct loop
*loop
, basic_block
*body
,
568 bitmap may_exit
, bitmap has_exit
)
573 struct loop
*outermost_exit
= loop
, *aexit
;
574 bool has_call
= false;
577 for (i
= 0; i
< loop
->num_nodes
; i
++)
579 if (body
[i
]->loop_father
== loop
)
581 FOR_BB_INSNS (body
[i
], insn
)
584 && (RTL_LOOPING_CONST_OR_PURE_CALL_P (insn
)
585 || !RTL_CONST_OR_PURE_CALL_P (insn
)))
588 bitmap_set_bit (may_exit
, i
);
593 FOR_EACH_EDGE (e
, ei
, body
[i
]->succs
)
595 if (flow_bb_inside_loop_p (loop
, e
->dest
))
598 bitmap_set_bit (may_exit
, i
);
599 bitmap_set_bit (has_exit
, i
);
600 outermost_exit
= find_common_loop (outermost_exit
,
601 e
->dest
->loop_father
);
606 /* Use the data stored for the subloop to decide whether we may exit
607 through it. It is sufficient to do this for header of the loop,
608 as other basic blocks inside it must be dominated by it. */
609 if (body
[i
]->loop_father
->header
!= body
[i
])
612 if (LOOP_DATA (body
[i
]->loop_father
)->has_call
)
615 bitmap_set_bit (may_exit
, i
);
617 aexit
= LOOP_DATA (body
[i
]->loop_father
)->outermost_exit
;
620 bitmap_set_bit (may_exit
, i
);
621 bitmap_set_bit (has_exit
, i
);
623 if (flow_loop_nested_p (aexit
, outermost_exit
))
624 outermost_exit
= aexit
;
628 if (loop
->aux
== NULL
)
630 loop
->aux
= xcalloc (1, sizeof (struct loop_data
));
631 bitmap_initialize (&LOOP_DATA (loop
)->regs_ref
, ®_obstack
);
632 bitmap_initialize (&LOOP_DATA (loop
)->regs_live
, ®_obstack
);
634 LOOP_DATA (loop
)->outermost_exit
= outermost_exit
;
635 LOOP_DATA (loop
)->has_call
= has_call
;
638 /* Check whether we may assign a value to X from a register. */
641 may_assign_reg_p (rtx x
)
643 return (GET_MODE (x
) != VOIDmode
644 && GET_MODE (x
) != BLKmode
645 && can_copy_p (GET_MODE (x
))
647 || !HARD_REGISTER_P (x
)
648 || REGNO_REG_CLASS (REGNO (x
)) != NO_REGS
));
651 /* Finds definitions that may correspond to invariants in LOOP with body
655 find_defs (struct loop
*loop
)
660 "*****starting processing of loop %d ******\n",
664 df_remove_problem (df_chain
);
665 df_process_deferred_rescans ();
666 df_chain_add_problem (DF_UD_CHAIN
);
667 df_set_flags (DF_RD_PRUNE_DEAD_DEFS
);
668 df_analyze_loop (loop
);
669 check_invariant_table_size ();
673 df_dump_region (dump_file
);
675 "*****ending processing of loop %d ******\n",
680 /* Creates a new invariant for definition DEF in INSN, depending on invariants
681 in DEPENDS_ON. ALWAYS_EXECUTED is true if the insn is always executed,
682 unless the program ends due to a function call. The newly created invariant
685 static struct invariant
*
686 create_new_invariant (struct def
*def
, rtx insn
, bitmap depends_on
,
687 bool always_executed
)
689 struct invariant
*inv
= XNEW (struct invariant
);
690 rtx set
= single_set (insn
);
691 bool speed
= optimize_bb_for_speed_p (BLOCK_FOR_INSN (insn
));
694 inv
->always_executed
= always_executed
;
695 inv
->depends_on
= depends_on
;
697 /* If the set is simple, usually by moving it we move the whole store out of
698 the loop. Otherwise we save only cost of the computation. */
701 inv
->cost
= set_rtx_cost (set
, speed
);
702 /* ??? Try to determine cheapness of address computation. Unfortunately
703 the address cost is only a relative measure, we can't really compare
704 it with any absolute number, but only with other address costs.
705 But here we don't have any other addresses, so compare with a magic
706 number anyway. It has to be large enough to not regress PR33928
707 (by avoiding to move reg+8,reg+16,reg+24 invariants), but small
708 enough to not regress 410.bwaves either (by still moving reg+reg
710 See http://gcc.gnu.org/ml/gcc-patches/2009-10/msg01210.html . */
711 inv
->cheap_address
= address_cost (SET_SRC (set
), word_mode
,
712 ADDR_SPACE_GENERIC
, speed
) < 3;
716 inv
->cost
= set_src_cost (SET_SRC (set
), speed
);
717 inv
->cheap_address
= false;
722 inv
->orig_regno
= -1;
726 inv
->invno
= invariants
.length ();
729 def
->invno
= inv
->invno
;
730 invariants
.safe_push (inv
);
735 "Set in insn %d is invariant (%d), cost %d, depends on ",
736 INSN_UID (insn
), inv
->invno
, inv
->cost
);
737 dump_bitmap (dump_file
, inv
->depends_on
);
743 /* Record USE at DEF. */
746 record_use (struct def
*def
, df_ref use
)
748 struct use
*u
= XNEW (struct use
);
750 u
->pos
= DF_REF_REAL_LOC (use
);
751 u
->insn
= DF_REF_INSN (use
);
752 u
->addr_use_p
= (DF_REF_TYPE (use
) == DF_REF_REG_MEM_LOAD
753 || DF_REF_TYPE (use
) == DF_REF_REG_MEM_STORE
);
761 /* Finds the invariants USE depends on and store them to the DEPENDS_ON
762 bitmap. Returns true if all dependencies of USE are known to be
763 loop invariants, false otherwise. */
766 check_dependency (basic_block bb
, df_ref use
, bitmap depends_on
)
770 struct df_link
*defs
;
771 struct def
*def_data
;
772 struct invariant
*inv
;
774 if (DF_REF_FLAGS (use
) & DF_REF_READ_WRITE
)
777 defs
= DF_REF_CHAIN (use
);
780 unsigned int regno
= DF_REF_REGNO (use
);
782 /* If this is the use of an uninitialized argument register that is
783 likely to be spilled, do not move it lest this might extend its
784 lifetime and cause reload to die. This can occur for a call to
785 a function taking complex number arguments and moving the insns
786 preparing the arguments without moving the call itself wouldn't
787 gain much in practice. */
788 if ((DF_REF_FLAGS (use
) & DF_HARD_REG_LIVE
)
789 && FUNCTION_ARG_REGNO_P (regno
)
790 && targetm
.class_likely_spilled_p (REGNO_REG_CLASS (regno
)))
800 check_invariant_table_size ();
801 inv
= invariant_table
[DF_REF_ID (def
)];
806 gcc_assert (def_data
!= NULL
);
808 def_bb
= DF_REF_BB (def
);
809 /* Note that in case bb == def_bb, we know that the definition
810 dominates insn, because def has invariant_table[DF_REF_ID(def)]
811 defined and we process the insns in the basic block bb
813 if (!dominated_by_p (CDI_DOMINATORS
, bb
, def_bb
))
816 bitmap_set_bit (depends_on
, def_data
->invno
);
821 /* Finds the invariants INSN depends on and store them to the DEPENDS_ON
822 bitmap. Returns true if all dependencies of INSN are known to be
823 loop invariants, false otherwise. */
826 check_dependencies (rtx insn
, bitmap depends_on
)
828 struct df_insn_info
*insn_info
= DF_INSN_INFO_GET (insn
);
830 basic_block bb
= BLOCK_FOR_INSN (insn
);
832 FOR_EACH_INSN_INFO_USE (use
, insn_info
)
833 if (!check_dependency (bb
, use
, depends_on
))
835 FOR_EACH_INSN_INFO_EQ_USE (use
, insn_info
)
836 if (!check_dependency (bb
, use
, depends_on
))
842 /* Finds invariant in INSN. ALWAYS_REACHED is true if the insn is always
843 executed. ALWAYS_EXECUTED is true if the insn is always executed,
844 unless the program ends due to a function call. */
847 find_invariant_insn (rtx insn
, bool always_reached
, bool always_executed
)
854 struct invariant
*inv
;
857 /* We can't move a CC0 setter without the user. */
858 if (sets_cc0_p (insn
))
862 set
= single_set (insn
);
865 dest
= SET_DEST (set
);
868 || HARD_REGISTER_P (dest
))
871 if (!may_assign_reg_p (SET_DEST (set
))
872 || !check_maybe_invariant (SET_SRC (set
)))
875 /* If the insn can throw exception, we cannot move it at all without changing
877 if (can_throw_internal (insn
))
880 /* We cannot make trapping insn executed, unless it was executed before. */
881 if (may_trap_or_fault_p (PATTERN (insn
)) && !always_reached
)
884 depends_on
= BITMAP_ALLOC (NULL
);
885 if (!check_dependencies (insn
, depends_on
))
887 BITMAP_FREE (depends_on
);
892 def
= XCNEW (struct def
);
896 inv
= create_new_invariant (def
, insn
, depends_on
, always_executed
);
900 ref
= df_find_def (insn
, dest
);
901 check_invariant_table_size ();
902 invariant_table
[DF_REF_ID (ref
)] = inv
;
906 /* Record registers used in INSN that have a unique invariant definition. */
909 record_uses (rtx insn
)
911 struct df_insn_info
*insn_info
= DF_INSN_INFO_GET (insn
);
913 struct invariant
*inv
;
915 FOR_EACH_INSN_INFO_USE (use
, insn_info
)
917 inv
= invariant_for_use (use
);
919 record_use (inv
->def
, use
);
921 FOR_EACH_INSN_INFO_EQ_USE (use
, insn_info
)
923 inv
= invariant_for_use (use
);
925 record_use (inv
->def
, use
);
929 /* Finds invariants in INSN. ALWAYS_REACHED is true if the insn is always
930 executed. ALWAYS_EXECUTED is true if the insn is always executed,
931 unless the program ends due to a function call. */
934 find_invariants_insn (rtx insn
, bool always_reached
, bool always_executed
)
936 find_invariant_insn (insn
, always_reached
, always_executed
);
940 /* Finds invariants in basic block BB. ALWAYS_REACHED is true if the
941 basic block is always executed. ALWAYS_EXECUTED is true if the basic
942 block is always executed, unless the program ends due to a function
946 find_invariants_bb (basic_block bb
, bool always_reached
, bool always_executed
)
950 FOR_BB_INSNS (bb
, insn
)
952 if (!NONDEBUG_INSN_P (insn
))
955 find_invariants_insn (insn
, always_reached
, always_executed
);
959 && (RTL_LOOPING_CONST_OR_PURE_CALL_P (insn
)
960 || ! RTL_CONST_OR_PURE_CALL_P (insn
)))
961 always_reached
= false;
965 /* Finds invariants in LOOP with body BODY. ALWAYS_REACHED is the bitmap of
966 basic blocks in BODY that are always executed. ALWAYS_EXECUTED is the
967 bitmap of basic blocks in BODY that are always executed unless the program
968 ends due to a function call. */
971 find_invariants_body (struct loop
*loop
, basic_block
*body
,
972 bitmap always_reached
, bitmap always_executed
)
976 for (i
= 0; i
< loop
->num_nodes
; i
++)
977 find_invariants_bb (body
[i
],
978 bitmap_bit_p (always_reached
, i
),
979 bitmap_bit_p (always_executed
, i
));
982 /* Finds invariants in LOOP. */
985 find_invariants (struct loop
*loop
)
987 bitmap may_exit
= BITMAP_ALLOC (NULL
);
988 bitmap always_reached
= BITMAP_ALLOC (NULL
);
989 bitmap has_exit
= BITMAP_ALLOC (NULL
);
990 bitmap always_executed
= BITMAP_ALLOC (NULL
);
991 basic_block
*body
= get_loop_body_in_dom_order (loop
);
993 find_exits (loop
, body
, may_exit
, has_exit
);
994 compute_always_reached (loop
, body
, may_exit
, always_reached
);
995 compute_always_reached (loop
, body
, has_exit
, always_executed
);
998 find_invariants_body (loop
, body
, always_reached
, always_executed
);
999 merge_identical_invariants ();
1001 BITMAP_FREE (always_reached
);
1002 BITMAP_FREE (always_executed
);
1003 BITMAP_FREE (may_exit
);
1004 BITMAP_FREE (has_exit
);
1008 /* Frees a list of uses USE. */
1011 free_use_list (struct use
*use
)
1015 for (; use
; use
= next
)
1022 /* Return pressure class and number of hard registers (through *NREGS)
1023 for destination of INSN. */
1024 static enum reg_class
1025 get_pressure_class_and_nregs (rtx insn
, int *nregs
)
1028 enum reg_class pressure_class
;
1029 rtx set
= single_set (insn
);
1031 /* Considered invariant insns have only one set. */
1032 gcc_assert (set
!= NULL_RTX
);
1033 reg
= SET_DEST (set
);
1034 if (GET_CODE (reg
) == SUBREG
)
1035 reg
= SUBREG_REG (reg
);
1039 pressure_class
= NO_REGS
;
1045 if (reg
== NULL_RTX
)
1046 pressure_class
= GENERAL_REGS
;
1049 pressure_class
= reg_allocno_class (REGNO (reg
));
1050 pressure_class
= ira_pressure_class_translate
[pressure_class
];
1053 = ira_reg_class_max_nregs
[pressure_class
][GET_MODE (SET_SRC (set
))];
1055 return pressure_class
;
1058 /* Calculates cost and number of registers needed for moving invariant INV
1059 out of the loop and stores them to *COST and *REGS_NEEDED. */
1062 get_inv_cost (struct invariant
*inv
, int *comp_cost
, unsigned *regs_needed
)
1065 unsigned aregs_needed
[N_REG_CLASSES
];
1067 struct invariant
*dep
;
1070 /* Find the representative of the class of the equivalent invariants. */
1071 inv
= invariants
[inv
->eqto
];
1074 if (! flag_ira_loop_pressure
)
1078 for (i
= 0; i
< ira_pressure_classes_num
; i
++)
1079 regs_needed
[ira_pressure_classes
[i
]] = 0;
1083 || inv
->stamp
== actual_stamp
)
1085 inv
->stamp
= actual_stamp
;
1087 if (! flag_ira_loop_pressure
)
1092 enum reg_class pressure_class
;
1094 pressure_class
= get_pressure_class_and_nregs (inv
->insn
, &nregs
);
1095 regs_needed
[pressure_class
] += nregs
;
1098 if (!inv
->cheap_address
1099 || inv
->def
->n_addr_uses
< inv
->def
->n_uses
)
1100 (*comp_cost
) += inv
->cost
;
1104 /* Hoisting constant pool constants into stack regs may cost more than
1105 just single register. On x87, the balance is affected both by the
1106 small number of FP registers, and by its register stack organization,
1107 that forces us to add compensation code in and around the loop to
1108 shuffle the operands to the top of stack before use, and pop them
1109 from the stack after the loop finishes.
1111 To model this effect, we increase the number of registers needed for
1112 stack registers by two: one register push, and one register pop.
1113 This usually has the effect that FP constant loads from the constant
1114 pool are not moved out of the loop.
1116 Note that this also means that dependent invariants can not be moved.
1117 However, the primary purpose of this pass is to move loop invariant
1118 address arithmetic out of loops, and address arithmetic that depends
1119 on floating point constants is unlikely to ever occur. */
1120 rtx set
= single_set (inv
->insn
);
1122 && IS_STACK_MODE (GET_MODE (SET_SRC (set
)))
1123 && constant_pool_constant_p (SET_SRC (set
)))
1125 if (flag_ira_loop_pressure
)
1126 regs_needed
[ira_stack_reg_pressure_class
] += 2;
1128 regs_needed
[0] += 2;
1133 EXECUTE_IF_SET_IN_BITMAP (inv
->depends_on
, 0, depno
, bi
)
1137 dep
= invariants
[depno
];
1139 /* If DEP is moved out of the loop, it is not a depends_on any more. */
1143 get_inv_cost (dep
, &acomp_cost
, aregs_needed
);
1145 if (! flag_ira_loop_pressure
)
1146 check_p
= aregs_needed
[0] != 0;
1149 for (i
= 0; i
< ira_pressure_classes_num
; i
++)
1150 if (aregs_needed
[ira_pressure_classes
[i
]] != 0)
1152 check_p
= i
< ira_pressure_classes_num
;
1155 /* We need to check always_executed, since if the original value of
1156 the invariant may be preserved, we may need to keep it in a
1157 separate register. TODO check whether the register has an
1158 use outside of the loop. */
1159 && dep
->always_executed
1160 && !dep
->def
->uses
->next
)
1162 /* If this is a single use, after moving the dependency we will not
1163 need a new register. */
1164 if (! flag_ira_loop_pressure
)
1169 enum reg_class pressure_class
;
1171 pressure_class
= get_pressure_class_and_nregs (inv
->insn
, &nregs
);
1172 aregs_needed
[pressure_class
] -= nregs
;
1176 if (! flag_ira_loop_pressure
)
1177 regs_needed
[0] += aregs_needed
[0];
1180 for (i
= 0; i
< ira_pressure_classes_num
; i
++)
1181 regs_needed
[ira_pressure_classes
[i
]]
1182 += aregs_needed
[ira_pressure_classes
[i
]];
1184 (*comp_cost
) += acomp_cost
;
1188 /* Calculates gain for eliminating invariant INV. REGS_USED is the number
1189 of registers used in the loop, NEW_REGS is the number of new variables
1190 already added due to the invariant motion. The number of registers needed
1191 for it is stored in *REGS_NEEDED. SPEED and CALL_P are flags passed
1192 through to estimate_reg_pressure_cost. */
1195 gain_for_invariant (struct invariant
*inv
, unsigned *regs_needed
,
1196 unsigned *new_regs
, unsigned regs_used
,
1197 bool speed
, bool call_p
)
1199 int comp_cost
, size_cost
;
1203 get_inv_cost (inv
, &comp_cost
, regs_needed
);
1205 if (! flag_ira_loop_pressure
)
1207 size_cost
= (estimate_reg_pressure_cost (new_regs
[0] + regs_needed
[0],
1208 regs_used
, speed
, call_p
)
1209 - estimate_reg_pressure_cost (new_regs
[0],
1210 regs_used
, speed
, call_p
));
1215 enum reg_class pressure_class
;
1217 for (i
= 0; i
< ira_pressure_classes_num
; i
++)
1219 pressure_class
= ira_pressure_classes
[i
];
1220 if ((int) new_regs
[pressure_class
]
1221 + (int) regs_needed
[pressure_class
]
1222 + LOOP_DATA (curr_loop
)->max_reg_pressure
[pressure_class
]
1223 + IRA_LOOP_RESERVED_REGS
1224 > ira_class_hard_regs_num
[pressure_class
])
1227 if (i
< ira_pressure_classes_num
)
1228 /* There will be register pressure excess and we want not to
1229 make this loop invariant motion. All loop invariants with
1230 non-positive gains will be rejected in function
1231 find_invariants_to_move. Therefore we return the negative
1234 One could think that this rejects also expensive loop
1235 invariant motions and this will hurt code performance.
1236 However numerous experiments with different heuristics
1237 taking invariant cost into account did not confirm this
1238 assumption. There are possible explanations for this
1240 o probably all expensive invariants were already moved out
1241 of the loop by PRE and gimple invariant motion pass.
1242 o expensive invariant execution will be hidden by insn
1243 scheduling or OOO processor hardware because usually such
1244 invariants have a lot of freedom to be executed
1246 Another reason for ignoring invariant cost vs spilling cost
1247 heuristics is also in difficulties to evaluate accurately
1248 spill cost at this stage. */
1254 return comp_cost
- size_cost
;
1257 /* Finds invariant with best gain for moving. Returns the gain, stores
1258 the invariant in *BEST and number of registers needed for it to
1259 *REGS_NEEDED. REGS_USED is the number of registers used in the loop.
1260 NEW_REGS is the number of new variables already added due to invariant
1264 best_gain_for_invariant (struct invariant
**best
, unsigned *regs_needed
,
1265 unsigned *new_regs
, unsigned regs_used
,
1266 bool speed
, bool call_p
)
1268 struct invariant
*inv
;
1269 int i
, gain
= 0, again
;
1270 unsigned aregs_needed
[N_REG_CLASSES
], invno
;
1272 FOR_EACH_VEC_ELT (invariants
, invno
, inv
)
1277 /* Only consider the "representatives" of equivalent invariants. */
1278 if (inv
->eqto
!= inv
->invno
)
1281 again
= gain_for_invariant (inv
, aregs_needed
, new_regs
, regs_used
,
1287 if (! flag_ira_loop_pressure
)
1288 regs_needed
[0] = aregs_needed
[0];
1291 for (i
= 0; i
< ira_pressure_classes_num
; i
++)
1292 regs_needed
[ira_pressure_classes
[i
]]
1293 = aregs_needed
[ira_pressure_classes
[i
]];
1301 /* Marks invariant INVNO and all its dependencies for moving. */
1304 set_move_mark (unsigned invno
, int gain
)
1306 struct invariant
*inv
= invariants
[invno
];
1309 /* Find the representative of the class of the equivalent invariants. */
1310 inv
= invariants
[inv
->eqto
];
1319 fprintf (dump_file
, "Decided to move invariant %d -- gain %d\n",
1322 fprintf (dump_file
, "Decided to move dependent invariant %d\n",
1326 EXECUTE_IF_SET_IN_BITMAP (inv
->depends_on
, 0, invno
, bi
)
1328 set_move_mark (invno
, -1);
1332 /* Determines which invariants to move. */
1335 find_invariants_to_move (bool speed
, bool call_p
)
1338 unsigned i
, regs_used
, regs_needed
[N_REG_CLASSES
], new_regs
[N_REG_CLASSES
];
1339 struct invariant
*inv
= NULL
;
1341 if (!invariants
.length ())
1344 if (flag_ira_loop_pressure
)
1345 /* REGS_USED is actually never used when the flag is on. */
1348 /* We do not really do a good job in estimating number of
1349 registers used; we put some initial bound here to stand for
1350 induction variables etc. that we do not detect. */
1352 unsigned int n_regs
= DF_REG_SIZE (df
);
1356 for (i
= 0; i
< n_regs
; i
++)
1358 if (!DF_REGNO_FIRST_DEF (i
) && DF_REGNO_LAST_USE (i
))
1360 /* This is a value that is used but not changed inside loop. */
1366 if (! flag_ira_loop_pressure
)
1367 new_regs
[0] = regs_needed
[0] = 0;
1370 for (i
= 0; (int) i
< ira_pressure_classes_num
; i
++)
1371 new_regs
[ira_pressure_classes
[i
]] = 0;
1373 while ((gain
= best_gain_for_invariant (&inv
, regs_needed
,
1374 new_regs
, regs_used
,
1375 speed
, call_p
)) > 0)
1377 set_move_mark (inv
->invno
, gain
);
1378 if (! flag_ira_loop_pressure
)
1379 new_regs
[0] += regs_needed
[0];
1382 for (i
= 0; (int) i
< ira_pressure_classes_num
; i
++)
1383 new_regs
[ira_pressure_classes
[i
]]
1384 += regs_needed
[ira_pressure_classes
[i
]];
1389 /* Replace the uses, reached by the definition of invariant INV, by REG.
1391 IN_GROUP is nonzero if this is part of a group of changes that must be
1392 performed as a group. In that case, the changes will be stored. The
1393 function `apply_change_group' will validate and apply the changes. */
1396 replace_uses (struct invariant
*inv
, rtx reg
, bool in_group
)
1398 /* Replace the uses we know to be dominated. It saves work for copy
1399 propagation, and also it is necessary so that dependent invariants
1400 are computed right. */
1404 for (use
= inv
->def
->uses
; use
; use
= use
->next
)
1405 validate_change (use
->insn
, use
->pos
, reg
, true);
1407 /* If we aren't part of a larger group, apply the changes now. */
1409 return apply_change_group ();
1415 /* Move invariant INVNO out of the LOOP. Returns true if this succeeds, false
1419 move_invariant_reg (struct loop
*loop
, unsigned invno
)
1421 struct invariant
*inv
= invariants
[invno
];
1422 struct invariant
*repr
= invariants
[inv
->eqto
];
1424 basic_block preheader
= loop_preheader_edge (loop
)->src
;
1425 rtx reg
, set
, dest
, note
;
1434 /* If this is a representative of the class of equivalent invariants,
1435 really move the invariant. Otherwise just replace its use with
1436 the register used for the representative. */
1439 if (inv
->depends_on
)
1441 EXECUTE_IF_SET_IN_BITMAP (inv
->depends_on
, 0, i
, bi
)
1443 if (!move_invariant_reg (loop
, i
))
1448 /* Move the set out of the loop. If the set is always executed (we could
1449 omit this condition if we know that the register is unused outside of
1450 the loop, but it does not seem worth finding out) and it has no uses
1451 that would not be dominated by it, we may just move it (TODO).
1452 Otherwise we need to create a temporary register. */
1453 set
= single_set (inv
->insn
);
1454 reg
= dest
= SET_DEST (set
);
1455 if (GET_CODE (reg
) == SUBREG
)
1456 reg
= SUBREG_REG (reg
);
1458 regno
= REGNO (reg
);
1460 reg
= gen_reg_rtx_and_attrs (dest
);
1462 /* Try replacing the destination by a new pseudoregister. */
1463 validate_change (inv
->insn
, &SET_DEST (set
), reg
, true);
1465 /* As well as all the dominated uses. */
1466 replace_uses (inv
, reg
, true);
1468 /* And validate all the changes. */
1469 if (!apply_change_group ())
1472 emit_insn_after (gen_move_insn (dest
, reg
), inv
->insn
);
1473 reorder_insns (inv
->insn
, inv
->insn
, BB_END (preheader
));
1475 /* If there is a REG_EQUAL note on the insn we just moved, and the
1476 insn is in a basic block that is not always executed or the note
1477 contains something for which we don't know the invariant status,
1478 the note may no longer be valid after we move the insn. Note that
1479 uses in REG_EQUAL notes are taken into account in the computation
1480 of invariants, so it is safe to retain the note even if it contains
1481 register references for which we know the invariant status. */
1482 if ((note
= find_reg_note (inv
->insn
, REG_EQUAL
, NULL_RTX
))
1483 && (!inv
->always_executed
1484 || !check_maybe_invariant (XEXP (note
, 0))))
1485 remove_note (inv
->insn
, note
);
1489 if (!move_invariant_reg (loop
, repr
->invno
))
1492 regno
= repr
->orig_regno
;
1493 if (!replace_uses (inv
, reg
, false))
1495 set
= single_set (inv
->insn
);
1496 emit_insn_after (gen_move_insn (SET_DEST (set
), reg
), inv
->insn
);
1497 delete_insn (inv
->insn
);
1501 inv
->orig_regno
= regno
;
1506 /* If we failed, clear move flag, so that we do not try to move inv
1509 fprintf (dump_file
, "Failed to move invariant %d\n", invno
);
1511 inv
->reg
= NULL_RTX
;
1512 inv
->orig_regno
= -1;
1517 /* Move selected invariant out of the LOOP. Newly created regs are marked
1518 in TEMPORARY_REGS. */
1521 move_invariants (struct loop
*loop
)
1523 struct invariant
*inv
;
1526 FOR_EACH_VEC_ELT (invariants
, i
, inv
)
1527 move_invariant_reg (loop
, i
);
1528 if (flag_ira_loop_pressure
&& resize_reg_info ())
1530 FOR_EACH_VEC_ELT (invariants
, i
, inv
)
1531 if (inv
->reg
!= NULL_RTX
)
1533 if (inv
->orig_regno
>= 0)
1534 setup_reg_classes (REGNO (inv
->reg
),
1535 reg_preferred_class (inv
->orig_regno
),
1536 reg_alternate_class (inv
->orig_regno
),
1537 reg_allocno_class (inv
->orig_regno
));
1539 setup_reg_classes (REGNO (inv
->reg
),
1540 GENERAL_REGS
, NO_REGS
, GENERAL_REGS
);
1545 /* Initializes invariant motion data. */
1548 init_inv_motion_data (void)
1552 invariants
.create (100);
1555 /* Frees the data allocated by invariant motion. */
1558 free_inv_motion_data (void)
1562 struct invariant
*inv
;
1564 check_invariant_table_size ();
1565 for (i
= 0; i
< DF_DEFS_TABLE_SIZE (); i
++)
1567 inv
= invariant_table
[i
];
1571 gcc_assert (def
!= NULL
);
1573 free_use_list (def
->uses
);
1575 invariant_table
[i
] = NULL
;
1579 FOR_EACH_VEC_ELT (invariants
, i
, inv
)
1581 BITMAP_FREE (inv
->depends_on
);
1584 invariants
.release ();
1587 /* Move the invariants out of the LOOP. */
1590 move_single_loop_invariants (struct loop
*loop
)
1592 init_inv_motion_data ();
1594 find_invariants (loop
);
1595 find_invariants_to_move (optimize_loop_for_speed_p (loop
),
1596 LOOP_DATA (loop
)->has_call
);
1597 move_invariants (loop
);
1599 free_inv_motion_data ();
1602 /* Releases the auxiliary data for LOOP. */
1605 free_loop_data (struct loop
*loop
)
1607 struct loop_data
*data
= LOOP_DATA (loop
);
1611 bitmap_clear (&LOOP_DATA (loop
)->regs_ref
);
1612 bitmap_clear (&LOOP_DATA (loop
)->regs_live
);
1619 /* Registers currently living. */
1620 static bitmap_head curr_regs_live
;
1622 /* Current reg pressure for each pressure class. */
1623 static int curr_reg_pressure
[N_REG_CLASSES
];
1625 /* Record all regs that are set in any one insn. Communication from
1626 mark_reg_{store,clobber} and global_conflicts. Asm can refer to
1627 all hard-registers. */
1628 static rtx regs_set
[(FIRST_PSEUDO_REGISTER
> MAX_RECOG_OPERANDS
1629 ? FIRST_PSEUDO_REGISTER
: MAX_RECOG_OPERANDS
) * 2];
1630 /* Number of regs stored in the previous array. */
1631 static int n_regs_set
;
1633 /* Return pressure class and number of needed hard registers (through
1634 *NREGS) of register REGNO. */
1635 static enum reg_class
1636 get_regno_pressure_class (int regno
, int *nregs
)
1638 if (regno
>= FIRST_PSEUDO_REGISTER
)
1640 enum reg_class pressure_class
;
1642 pressure_class
= reg_allocno_class (regno
);
1643 pressure_class
= ira_pressure_class_translate
[pressure_class
];
1645 = ira_reg_class_max_nregs
[pressure_class
][PSEUDO_REGNO_MODE (regno
)];
1646 return pressure_class
;
1648 else if (! TEST_HARD_REG_BIT (ira_no_alloc_regs
, regno
)
1649 && ! TEST_HARD_REG_BIT (eliminable_regset
, regno
))
1652 return ira_pressure_class_translate
[REGNO_REG_CLASS (regno
)];
1661 /* Increase (if INCR_P) or decrease current register pressure for
1664 change_pressure (int regno
, bool incr_p
)
1667 enum reg_class pressure_class
;
1669 pressure_class
= get_regno_pressure_class (regno
, &nregs
);
1671 curr_reg_pressure
[pressure_class
] -= nregs
;
1674 curr_reg_pressure
[pressure_class
] += nregs
;
1675 if (LOOP_DATA (curr_loop
)->max_reg_pressure
[pressure_class
]
1676 < curr_reg_pressure
[pressure_class
])
1677 LOOP_DATA (curr_loop
)->max_reg_pressure
[pressure_class
]
1678 = curr_reg_pressure
[pressure_class
];
1682 /* Mark REGNO birth. */
1684 mark_regno_live (int regno
)
1688 for (loop
= curr_loop
;
1689 loop
!= current_loops
->tree_root
;
1690 loop
= loop_outer (loop
))
1691 bitmap_set_bit (&LOOP_DATA (loop
)->regs_live
, regno
);
1692 if (!bitmap_set_bit (&curr_regs_live
, regno
))
1694 change_pressure (regno
, true);
1697 /* Mark REGNO death. */
1699 mark_regno_death (int regno
)
1701 if (! bitmap_clear_bit (&curr_regs_live
, regno
))
1703 change_pressure (regno
, false);
1706 /* Mark setting register REG. */
1708 mark_reg_store (rtx reg
, const_rtx setter ATTRIBUTE_UNUSED
,
1709 void *data ATTRIBUTE_UNUSED
)
1713 if (GET_CODE (reg
) == SUBREG
)
1714 reg
= SUBREG_REG (reg
);
1719 regs_set
[n_regs_set
++] = reg
;
1721 regno
= REGNO (reg
);
1723 if (regno
>= FIRST_PSEUDO_REGISTER
)
1724 mark_regno_live (regno
);
1727 int last
= regno
+ hard_regno_nregs
[regno
][GET_MODE (reg
)];
1729 while (regno
< last
)
1731 mark_regno_live (regno
);
1737 /* Mark clobbering register REG. */
1739 mark_reg_clobber (rtx reg
, const_rtx setter
, void *data
)
1741 if (GET_CODE (setter
) == CLOBBER
)
1742 mark_reg_store (reg
, setter
, data
);
1745 /* Mark register REG death. */
1747 mark_reg_death (rtx reg
)
1749 int regno
= REGNO (reg
);
1751 if (regno
>= FIRST_PSEUDO_REGISTER
)
1752 mark_regno_death (regno
);
1755 int last
= regno
+ hard_regno_nregs
[regno
][GET_MODE (reg
)];
1757 while (regno
< last
)
1759 mark_regno_death (regno
);
1765 /* Mark occurrence of registers in X for the current loop. */
1767 mark_ref_regs (rtx x
)
1776 code
= GET_CODE (x
);
1781 for (loop
= curr_loop
;
1782 loop
!= current_loops
->tree_root
;
1783 loop
= loop_outer (loop
))
1784 bitmap_set_bit (&LOOP_DATA (loop
)->regs_ref
, REGNO (x
));
1788 fmt
= GET_RTX_FORMAT (code
);
1789 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
1791 mark_ref_regs (XEXP (x
, i
));
1792 else if (fmt
[i
] == 'E')
1796 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
1797 mark_ref_regs (XVECEXP (x
, i
, j
));
1801 /* Calculate register pressure in the loops. */
1803 calculate_loop_reg_pressure (void)
1810 struct loop
*loop
, *parent
;
1812 FOR_EACH_LOOP (loop
, 0)
1813 if (loop
->aux
== NULL
)
1815 loop
->aux
= xcalloc (1, sizeof (struct loop_data
));
1816 bitmap_initialize (&LOOP_DATA (loop
)->regs_ref
, ®_obstack
);
1817 bitmap_initialize (&LOOP_DATA (loop
)->regs_live
, ®_obstack
);
1819 ira_setup_eliminable_regset ();
1820 bitmap_initialize (&curr_regs_live
, ®_obstack
);
1821 FOR_EACH_BB_FN (bb
, cfun
)
1823 curr_loop
= bb
->loop_father
;
1824 if (curr_loop
== current_loops
->tree_root
)
1827 for (loop
= curr_loop
;
1828 loop
!= current_loops
->tree_root
;
1829 loop
= loop_outer (loop
))
1830 bitmap_ior_into (&LOOP_DATA (loop
)->regs_live
, DF_LR_IN (bb
));
1832 bitmap_copy (&curr_regs_live
, DF_LR_IN (bb
));
1833 for (i
= 0; i
< ira_pressure_classes_num
; i
++)
1834 curr_reg_pressure
[ira_pressure_classes
[i
]] = 0;
1835 EXECUTE_IF_SET_IN_BITMAP (&curr_regs_live
, 0, j
, bi
)
1836 change_pressure (j
, true);
1838 FOR_BB_INSNS (bb
, insn
)
1840 if (! NONDEBUG_INSN_P (insn
))
1843 mark_ref_regs (PATTERN (insn
));
1845 note_stores (PATTERN (insn
), mark_reg_clobber
, NULL
);
1847 /* Mark any registers dead after INSN as dead now. */
1849 for (link
= REG_NOTES (insn
); link
; link
= XEXP (link
, 1))
1850 if (REG_NOTE_KIND (link
) == REG_DEAD
)
1851 mark_reg_death (XEXP (link
, 0));
1853 /* Mark any registers set in INSN as live,
1854 and mark them as conflicting with all other live regs.
1855 Clobbers are processed again, so they conflict with
1856 the registers that are set. */
1858 note_stores (PATTERN (insn
), mark_reg_store
, NULL
);
1861 for (link
= REG_NOTES (insn
); link
; link
= XEXP (link
, 1))
1862 if (REG_NOTE_KIND (link
) == REG_INC
)
1863 mark_reg_store (XEXP (link
, 0), NULL_RTX
, NULL
);
1865 while (n_regs_set
-- > 0)
1867 rtx note
= find_regno_note (insn
, REG_UNUSED
,
1868 REGNO (regs_set
[n_regs_set
]));
1872 mark_reg_death (XEXP (note
, 0));
1876 bitmap_clear (&curr_regs_live
);
1877 if (flag_ira_region
== IRA_REGION_MIXED
1878 || flag_ira_region
== IRA_REGION_ALL
)
1879 FOR_EACH_LOOP (loop
, 0)
1881 EXECUTE_IF_SET_IN_BITMAP (&LOOP_DATA (loop
)->regs_live
, 0, j
, bi
)
1882 if (! bitmap_bit_p (&LOOP_DATA (loop
)->regs_ref
, j
))
1884 enum reg_class pressure_class
;
1887 pressure_class
= get_regno_pressure_class (j
, &nregs
);
1888 LOOP_DATA (loop
)->max_reg_pressure
[pressure_class
] -= nregs
;
1891 if (dump_file
== NULL
)
1893 FOR_EACH_LOOP (loop
, 0)
1895 parent
= loop_outer (loop
);
1896 fprintf (dump_file
, "\n Loop %d (parent %d, header bb%d, depth %d)\n",
1897 loop
->num
, (parent
== NULL
? -1 : parent
->num
),
1898 loop
->header
->index
, loop_depth (loop
));
1899 fprintf (dump_file
, "\n ref. regnos:");
1900 EXECUTE_IF_SET_IN_BITMAP (&LOOP_DATA (loop
)->regs_ref
, 0, j
, bi
)
1901 fprintf (dump_file
, " %d", j
);
1902 fprintf (dump_file
, "\n live regnos:");
1903 EXECUTE_IF_SET_IN_BITMAP (&LOOP_DATA (loop
)->regs_live
, 0, j
, bi
)
1904 fprintf (dump_file
, " %d", j
);
1905 fprintf (dump_file
, "\n Pressure:");
1906 for (i
= 0; (int) i
< ira_pressure_classes_num
; i
++)
1908 enum reg_class pressure_class
;
1910 pressure_class
= ira_pressure_classes
[i
];
1911 if (LOOP_DATA (loop
)->max_reg_pressure
[pressure_class
] == 0)
1913 fprintf (dump_file
, " %s=%d", reg_class_names
[pressure_class
],
1914 LOOP_DATA (loop
)->max_reg_pressure
[pressure_class
]);
1916 fprintf (dump_file
, "\n");
1922 /* Move the invariants out of the loops. */
1925 move_loop_invariants (void)
1929 if (flag_ira_loop_pressure
)
1932 regstat_init_n_sets_and_refs ();
1933 ira_set_pseudo_classes (true, dump_file
);
1934 calculate_loop_reg_pressure ();
1935 regstat_free_n_sets_and_refs ();
1937 df_set_flags (DF_EQ_NOTES
+ DF_DEFER_INSN_RESCAN
);
1938 /* Process the loops, innermost first. */
1939 FOR_EACH_LOOP (loop
, LI_FROM_INNERMOST
)
1942 /* move_single_loop_invariants for very large loops
1943 is time consuming and might need a lot of memory. */
1944 if (loop
->num_nodes
<= (unsigned) LOOP_INVARIANT_MAX_BBS_IN_LOOP
)
1945 move_single_loop_invariants (loop
);
1948 FOR_EACH_LOOP (loop
, 0)
1950 free_loop_data (loop
);
1953 if (flag_ira_loop_pressure
)
1954 /* There is no sense to keep this info because it was most
1955 probably outdated by subsequent passes. */
1957 free (invariant_table
);
1958 invariant_table
= NULL
;
1959 invariant_table_size
= 0;
1961 #ifdef ENABLE_CHECKING
1962 verify_flow_info ();