1 /* Common subexpression elimination library for GNU compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011,
4 2012 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
24 #include "coretypes.h"
28 #include "tree.h"/* FIXME: For hashing DEBUG_EXPR & friends. */
31 #include "hard-reg-set.h"
33 #include "insn-config.h"
37 #include "diagnostic-core.h"
44 #include "alloc-pool.h"
48 /* A list of cselib_val structures. */
50 struct elt_list
*next
;
54 static bool cselib_record_memory
;
55 static bool cselib_preserve_constants
;
56 static bool cselib_any_perm_equivs
;
57 static int entry_and_rtx_equal_p (const void *, const void *);
58 static hashval_t
get_value_hash (const void *);
59 static struct elt_list
*new_elt_list (struct elt_list
*, cselib_val
*);
60 static void new_elt_loc_list (cselib_val
*, rtx
);
61 static void unchain_one_value (cselib_val
*);
62 static void unchain_one_elt_list (struct elt_list
**);
63 static void unchain_one_elt_loc_list (struct elt_loc_list
**);
64 static int discard_useless_locs (void **, void *);
65 static int discard_useless_values (void **, void *);
66 static void remove_useless_values (void);
67 static int rtx_equal_for_cselib_1 (rtx
, rtx
, enum machine_mode
);
68 static unsigned int cselib_hash_rtx (rtx
, int, enum machine_mode
);
69 static cselib_val
*new_cselib_val (unsigned int, enum machine_mode
, rtx
);
70 static void add_mem_for_addr (cselib_val
*, cselib_val
*, rtx
);
71 static cselib_val
*cselib_lookup_mem (rtx
, int);
72 static void cselib_invalidate_regno (unsigned int, enum machine_mode
);
73 static void cselib_invalidate_mem (rtx
);
74 static void cselib_record_set (rtx
, cselib_val
*, cselib_val
*);
75 static void cselib_record_sets (rtx
);
77 struct expand_value_data
80 cselib_expand_callback callback
;
85 static rtx
cselib_expand_value_rtx_1 (rtx
, struct expand_value_data
*, int);
87 /* There are three ways in which cselib can look up an rtx:
88 - for a REG, the reg_values table (which is indexed by regno) is used
89 - for a MEM, we recursively look up its address and then follow the
90 addr_list of that value
91 - for everything else, we compute a hash value and go through the hash
92 table. Since different rtx's can still have the same hash value,
93 this involves walking the table entries for a given value and comparing
94 the locations of the entries with the rtx we are looking up. */
96 /* A table that enables us to look up elts by their value. */
97 static htab_t cselib_hash_table
;
99 /* This is a global so we don't have to pass this through every function.
100 It is used in new_elt_loc_list to set SETTING_INSN. */
101 static rtx cselib_current_insn
;
103 /* The unique id that the next create value will take. */
104 static unsigned int next_uid
;
106 /* The number of registers we had when the varrays were last resized. */
107 static unsigned int cselib_nregs
;
109 /* Count values without known locations, or with only locations that
110 wouldn't have been known except for debug insns. Whenever this
111 grows too big, we remove these useless values from the table.
113 Counting values with only debug values is a bit tricky. We don't
114 want to increment n_useless_values when we create a value for a
115 debug insn, for this would get n_useless_values out of sync, but we
116 want increment it if all locs in the list that were ever referenced
117 in nondebug insns are removed from the list.
119 In the general case, once we do that, we'd have to stop accepting
120 nondebug expressions in the loc list, to avoid having two values
121 equivalent that, without debug insns, would have been made into
122 separate values. However, because debug insns never introduce
123 equivalences themselves (no assignments), the only means for
124 growing loc lists is through nondebug assignments. If the locs
125 also happen to be referenced in debug insns, it will work just fine.
127 A consequence of this is that there's at most one debug-only loc in
128 each loc list. If we keep it in the first entry, testing whether
129 we have a debug-only loc list takes O(1).
131 Furthermore, since any additional entry in a loc list containing a
132 debug loc would have to come from an assignment (nondebug) that
133 references both the initial debug loc and the newly-equivalent loc,
134 the initial debug loc would be promoted to a nondebug loc, and the
135 loc list would not contain debug locs any more.
137 So the only case we have to be careful with in order to keep
138 n_useless_values in sync between debug and nondebug compilations is
139 to avoid incrementing n_useless_values when removing the single loc
140 from a value that turns out to not appear outside debug values. We
141 increment n_useless_debug_values instead, and leave such values
142 alone until, for other reasons, we garbage-collect useless
144 static int n_useless_values
;
145 static int n_useless_debug_values
;
147 /* Count values whose locs have been taken exclusively from debug
148 insns for the entire life of the value. */
149 static int n_debug_values
;
151 /* Number of useless values before we remove them from the hash table. */
152 #define MAX_USELESS_VALUES 32
154 /* This table maps from register number to values. It does not
155 contain pointers to cselib_val structures, but rather elt_lists.
156 The purpose is to be able to refer to the same register in
157 different modes. The first element of the list defines the mode in
158 which the register was set; if the mode is unknown or the value is
159 no longer valid in that mode, ELT will be NULL for the first
161 static struct elt_list
**reg_values
;
162 static unsigned int reg_values_size
;
163 #define REG_VALUES(i) reg_values[i]
165 /* The largest number of hard regs used by any entry added to the
166 REG_VALUES table. Cleared on each cselib_clear_table() invocation. */
167 static unsigned int max_value_regs
;
169 /* Here the set of indices I with REG_VALUES(I) != 0 is saved. This is used
170 in cselib_clear_table() for fast emptying. */
171 static unsigned int *used_regs
;
172 static unsigned int n_used_regs
;
174 /* We pass this to cselib_invalidate_mem to invalidate all of
175 memory for a non-const call instruction. */
176 static GTY(()) rtx callmem
;
178 /* Set by discard_useless_locs if it deleted the last location of any
180 static int values_became_useless
;
182 /* Used as stop element of the containing_mem list so we can check
183 presence in the list by checking the next pointer. */
184 static cselib_val dummy_val
;
186 /* If non-NULL, value of the eliminated arg_pointer_rtx or frame_pointer_rtx
187 that is constant through the whole function and should never be
189 static cselib_val
*cfa_base_preserved_val
;
190 static unsigned int cfa_base_preserved_regno
= INVALID_REGNUM
;
192 /* Used to list all values that contain memory reference.
193 May or may not contain the useless values - the list is compacted
194 each time memory is invalidated. */
195 static cselib_val
*first_containing_mem
= &dummy_val
;
196 static alloc_pool elt_loc_list_pool
, elt_list_pool
, cselib_val_pool
, value_pool
;
198 /* If nonnull, cselib will call this function before freeing useless
199 VALUEs. A VALUE is deemed useless if its "locs" field is null. */
200 void (*cselib_discard_hook
) (cselib_val
*);
202 /* If nonnull, cselib will call this function before recording sets or
203 even clobbering outputs of INSN. All the recorded sets will be
204 represented in the array sets[n_sets]. new_val_min can be used to
205 tell whether values present in sets are introduced by this
207 void (*cselib_record_sets_hook
) (rtx insn
, struct cselib_set
*sets
,
210 #define PRESERVED_VALUE_P(RTX) \
211 (RTL_FLAG_CHECK1("PRESERVED_VALUE_P", (RTX), VALUE)->unchanging)
215 /* Allocate a struct elt_list and fill in its two elements with the
218 static inline struct elt_list
*
219 new_elt_list (struct elt_list
*next
, cselib_val
*elt
)
222 el
= (struct elt_list
*) pool_alloc (elt_list_pool
);
228 /* Allocate a struct elt_loc_list with LOC and prepend it to VAL's loc
232 new_elt_loc_list (cselib_val
*val
, rtx loc
)
234 struct elt_loc_list
*el
, *next
= val
->locs
;
236 gcc_checking_assert (!next
|| !next
->setting_insn
237 || !DEBUG_INSN_P (next
->setting_insn
)
238 || cselib_current_insn
== next
->setting_insn
);
240 /* If we're creating the first loc in a debug insn context, we've
241 just created a debug value. Count it. */
242 if (!next
&& cselib_current_insn
&& DEBUG_INSN_P (cselib_current_insn
))
245 val
= canonical_cselib_val (val
);
248 if (GET_CODE (loc
) == VALUE
)
250 loc
= canonical_cselib_val (CSELIB_VAL_PTR (loc
))->val_rtx
;
252 gcc_checking_assert (PRESERVED_VALUE_P (loc
)
253 == PRESERVED_VALUE_P (val
->val_rtx
));
255 if (val
->val_rtx
== loc
)
257 else if (val
->uid
> CSELIB_VAL_PTR (loc
)->uid
)
259 /* Reverse the insertion. */
260 new_elt_loc_list (CSELIB_VAL_PTR (loc
), val
->val_rtx
);
264 gcc_checking_assert (val
->uid
< CSELIB_VAL_PTR (loc
)->uid
);
266 if (CSELIB_VAL_PTR (loc
)->locs
)
268 /* Bring all locs from LOC to VAL. */
269 for (el
= CSELIB_VAL_PTR (loc
)->locs
; el
->next
; el
= el
->next
)
271 /* Adjust values that have LOC as canonical so that VAL
272 becomes their canonical. */
273 if (el
->loc
&& GET_CODE (el
->loc
) == VALUE
)
275 gcc_checking_assert (CSELIB_VAL_PTR (el
->loc
)->locs
->loc
277 CSELIB_VAL_PTR (el
->loc
)->locs
->loc
= val
->val_rtx
;
280 el
->next
= val
->locs
;
281 next
= val
->locs
= CSELIB_VAL_PTR (loc
)->locs
;
284 if (CSELIB_VAL_PTR (loc
)->addr_list
)
286 /* Bring in addr_list into canonical node. */
287 struct elt_list
*last
= CSELIB_VAL_PTR (loc
)->addr_list
;
290 last
->next
= val
->addr_list
;
291 val
->addr_list
= CSELIB_VAL_PTR (loc
)->addr_list
;
292 CSELIB_VAL_PTR (loc
)->addr_list
= NULL
;
295 if (CSELIB_VAL_PTR (loc
)->next_containing_mem
!= NULL
296 && val
->next_containing_mem
== NULL
)
298 /* Add VAL to the containing_mem list after LOC. LOC will
299 be removed when we notice it doesn't contain any
301 val
->next_containing_mem
= CSELIB_VAL_PTR (loc
)->next_containing_mem
;
302 CSELIB_VAL_PTR (loc
)->next_containing_mem
= val
;
305 /* Chain LOC back to VAL. */
306 el
= (struct elt_loc_list
*) pool_alloc (elt_loc_list_pool
);
307 el
->loc
= val
->val_rtx
;
308 el
->setting_insn
= cselib_current_insn
;
310 CSELIB_VAL_PTR (loc
)->locs
= el
;
313 el
= (struct elt_loc_list
*) pool_alloc (elt_loc_list_pool
);
315 el
->setting_insn
= cselib_current_insn
;
320 /* Promote loc L to a nondebug cselib_current_insn if L is marked as
321 originating from a debug insn, maintaining the debug values
325 promote_debug_loc (struct elt_loc_list
*l
)
327 if (l
&& l
->setting_insn
&& DEBUG_INSN_P (l
->setting_insn
)
328 && (!cselib_current_insn
|| !DEBUG_INSN_P (cselib_current_insn
)))
331 l
->setting_insn
= cselib_current_insn
;
332 if (cselib_preserve_constants
&& l
->next
)
334 gcc_assert (l
->next
->setting_insn
335 && DEBUG_INSN_P (l
->next
->setting_insn
)
337 l
->next
->setting_insn
= cselib_current_insn
;
340 gcc_assert (!l
->next
);
344 /* The elt_list at *PL is no longer needed. Unchain it and free its
348 unchain_one_elt_list (struct elt_list
**pl
)
350 struct elt_list
*l
= *pl
;
353 pool_free (elt_list_pool
, l
);
356 /* Likewise for elt_loc_lists. */
359 unchain_one_elt_loc_list (struct elt_loc_list
**pl
)
361 struct elt_loc_list
*l
= *pl
;
364 pool_free (elt_loc_list_pool
, l
);
367 /* Likewise for cselib_vals. This also frees the addr_list associated with
371 unchain_one_value (cselib_val
*v
)
374 unchain_one_elt_list (&v
->addr_list
);
376 pool_free (cselib_val_pool
, v
);
379 /* Remove all entries from the hash table. Also used during
383 cselib_clear_table (void)
385 cselib_reset_table (1);
388 /* Return TRUE if V is a constant, a function invariant or a VALUE
389 equivalence; FALSE otherwise. */
392 invariant_or_equiv_p (cselib_val
*v
)
394 struct elt_loc_list
*l
;
396 if (v
== cfa_base_preserved_val
)
399 /* Keep VALUE equivalences around. */
400 for (l
= v
->locs
; l
; l
= l
->next
)
401 if (GET_CODE (l
->loc
) == VALUE
)
405 && v
->locs
->next
== NULL
)
407 if (CONSTANT_P (v
->locs
->loc
)
408 && (GET_CODE (v
->locs
->loc
) != CONST
409 || !references_value_p (v
->locs
->loc
, 0)))
411 /* Although a debug expr may be bound to different expressions,
412 we can preserve it as if it was constant, to get unification
413 and proper merging within var-tracking. */
414 if (GET_CODE (v
->locs
->loc
) == DEBUG_EXPR
415 || GET_CODE (v
->locs
->loc
) == DEBUG_IMPLICIT_PTR
416 || GET_CODE (v
->locs
->loc
) == ENTRY_VALUE
417 || GET_CODE (v
->locs
->loc
) == DEBUG_PARAMETER_REF
)
420 /* (plus (value V) (const_int C)) is invariant iff V is invariant. */
421 if (GET_CODE (v
->locs
->loc
) == PLUS
422 && CONST_INT_P (XEXP (v
->locs
->loc
, 1))
423 && GET_CODE (XEXP (v
->locs
->loc
, 0)) == VALUE
424 && invariant_or_equiv_p (CSELIB_VAL_PTR (XEXP (v
->locs
->loc
, 0))))
431 /* Remove from hash table all VALUEs except constants, function
432 invariants and VALUE equivalences. */
435 preserve_constants_and_equivs (void **x
, void *info ATTRIBUTE_UNUSED
)
437 cselib_val
*v
= (cselib_val
*)*x
;
439 if (!invariant_or_equiv_p (v
))
440 htab_clear_slot (cselib_hash_table
, x
);
444 /* Remove all entries from the hash table, arranging for the next
445 value to be numbered NUM. */
448 cselib_reset_table (unsigned int num
)
454 if (cfa_base_preserved_val
)
456 unsigned int regno
= cfa_base_preserved_regno
;
457 unsigned int new_used_regs
= 0;
458 for (i
= 0; i
< n_used_regs
; i
++)
459 if (used_regs
[i
] == regno
)
465 REG_VALUES (used_regs
[i
]) = 0;
466 gcc_assert (new_used_regs
== 1);
467 n_used_regs
= new_used_regs
;
468 used_regs
[0] = regno
;
470 = hard_regno_nregs
[regno
][GET_MODE (cfa_base_preserved_val
->locs
->loc
)];
474 for (i
= 0; i
< n_used_regs
; i
++)
475 REG_VALUES (used_regs
[i
]) = 0;
479 if (cselib_preserve_constants
)
480 htab_traverse (cselib_hash_table
, preserve_constants_and_equivs
, NULL
);
483 htab_empty (cselib_hash_table
);
484 gcc_checking_assert (!cselib_any_perm_equivs
);
487 n_useless_values
= 0;
488 n_useless_debug_values
= 0;
493 first_containing_mem
= &dummy_val
;
496 /* Return the number of the next value that will be generated. */
499 cselib_get_next_uid (void)
504 /* See the documentation of cselib_find_slot below. */
505 static enum machine_mode find_slot_memmode
;
507 /* Search for X, whose hashcode is HASH, in CSELIB_HASH_TABLE,
508 INSERTing if requested. When X is part of the address of a MEM,
509 MEMMODE should specify the mode of the MEM. While searching the
510 table, MEMMODE is held in FIND_SLOT_MEMMODE, so that autoinc RTXs
511 in X can be resolved. */
514 cselib_find_slot (rtx x
, hashval_t hash
, enum insert_option insert
,
515 enum machine_mode memmode
)
518 find_slot_memmode
= memmode
;
519 slot
= htab_find_slot_with_hash (cselib_hash_table
, x
, hash
, insert
);
520 find_slot_memmode
= VOIDmode
;
524 /* The equality test for our hash table. The first argument ENTRY is a table
525 element (i.e. a cselib_val), while the second arg X is an rtx. We know
526 that all callers of htab_find_slot_with_hash will wrap CONST_INTs into a
527 CONST of an appropriate mode. */
530 entry_and_rtx_equal_p (const void *entry
, const void *x_arg
)
532 struct elt_loc_list
*l
;
533 const cselib_val
*const v
= (const cselib_val
*) entry
;
534 rtx x
= CONST_CAST_RTX ((const_rtx
)x_arg
);
535 enum machine_mode mode
= GET_MODE (x
);
537 gcc_assert (!CONST_INT_P (x
) && GET_CODE (x
) != CONST_FIXED
538 && (mode
!= VOIDmode
|| GET_CODE (x
) != CONST_DOUBLE
));
540 if (mode
!= GET_MODE (v
->val_rtx
))
543 /* Unwrap X if necessary. */
544 if (GET_CODE (x
) == CONST
545 && (CONST_INT_P (XEXP (x
, 0))
546 || GET_CODE (XEXP (x
, 0)) == CONST_FIXED
547 || GET_CODE (XEXP (x
, 0)) == CONST_DOUBLE
))
550 /* We don't guarantee that distinct rtx's have different hash values,
551 so we need to do a comparison. */
552 for (l
= v
->locs
; l
; l
= l
->next
)
553 if (rtx_equal_for_cselib_1 (l
->loc
, x
, find_slot_memmode
))
555 promote_debug_loc (l
);
562 /* The hash function for our hash table. The value is always computed with
563 cselib_hash_rtx when adding an element; this function just extracts the
564 hash value from a cselib_val structure. */
567 get_value_hash (const void *entry
)
569 const cselib_val
*const v
= (const cselib_val
*) entry
;
573 /* Return true if X contains a VALUE rtx. If ONLY_USELESS is set, we
574 only return true for values which point to a cselib_val whose value
575 element has been set to zero, which implies the cselib_val will be
579 references_value_p (const_rtx x
, int only_useless
)
581 const enum rtx_code code
= GET_CODE (x
);
582 const char *fmt
= GET_RTX_FORMAT (code
);
585 if (GET_CODE (x
) == VALUE
586 && (! only_useless
||
587 (CSELIB_VAL_PTR (x
)->locs
== 0 && !PRESERVED_VALUE_P (x
))))
590 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
592 if (fmt
[i
] == 'e' && references_value_p (XEXP (x
, i
), only_useless
))
594 else if (fmt
[i
] == 'E')
595 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
596 if (references_value_p (XVECEXP (x
, i
, j
), only_useless
))
603 /* For all locations found in X, delete locations that reference useless
604 values (i.e. values without any location). Called through
608 discard_useless_locs (void **x
, void *info ATTRIBUTE_UNUSED
)
610 cselib_val
*v
= (cselib_val
*)*x
;
611 struct elt_loc_list
**p
= &v
->locs
;
612 bool had_locs
= v
->locs
!= NULL
;
613 rtx setting_insn
= v
->locs
? v
->locs
->setting_insn
: NULL
;
617 if (references_value_p ((*p
)->loc
, 1))
618 unchain_one_elt_loc_list (p
);
623 if (had_locs
&& v
->locs
== 0 && !PRESERVED_VALUE_P (v
->val_rtx
))
625 if (setting_insn
&& DEBUG_INSN_P (setting_insn
))
626 n_useless_debug_values
++;
629 values_became_useless
= 1;
634 /* If X is a value with no locations, remove it from the hashtable. */
637 discard_useless_values (void **x
, void *info ATTRIBUTE_UNUSED
)
639 cselib_val
*v
= (cselib_val
*)*x
;
641 if (v
->locs
== 0 && !PRESERVED_VALUE_P (v
->val_rtx
))
643 if (cselib_discard_hook
)
644 cselib_discard_hook (v
);
646 CSELIB_VAL_PTR (v
->val_rtx
) = NULL
;
647 htab_clear_slot (cselib_hash_table
, x
);
648 unchain_one_value (v
);
655 /* Clean out useless values (i.e. those which no longer have locations
656 associated with them) from the hash table. */
659 remove_useless_values (void)
663 /* First pass: eliminate locations that reference the value. That in
664 turn can make more values useless. */
667 values_became_useless
= 0;
668 htab_traverse (cselib_hash_table
, discard_useless_locs
, 0);
670 while (values_became_useless
);
672 /* Second pass: actually remove the values. */
674 p
= &first_containing_mem
;
675 for (v
= *p
; v
!= &dummy_val
; v
= v
->next_containing_mem
)
676 if (v
->locs
&& v
== canonical_cselib_val (v
))
679 p
= &(*p
)->next_containing_mem
;
683 n_useless_values
+= n_useless_debug_values
;
684 n_debug_values
-= n_useless_debug_values
;
685 n_useless_debug_values
= 0;
687 htab_traverse (cselib_hash_table
, discard_useless_values
, 0);
689 gcc_assert (!n_useless_values
);
692 /* Arrange for a value to not be removed from the hash table even if
693 it becomes useless. */
696 cselib_preserve_value (cselib_val
*v
)
698 PRESERVED_VALUE_P (v
->val_rtx
) = 1;
701 /* Test whether a value is preserved. */
704 cselib_preserved_value_p (cselib_val
*v
)
706 return PRESERVED_VALUE_P (v
->val_rtx
);
709 /* Arrange for a REG value to be assumed constant through the whole function,
710 never invalidated and preserved across cselib_reset_table calls. */
713 cselib_preserve_cfa_base_value (cselib_val
*v
, unsigned int regno
)
715 if (cselib_preserve_constants
717 && REG_P (v
->locs
->loc
))
719 cfa_base_preserved_val
= v
;
720 cfa_base_preserved_regno
= regno
;
724 /* Clean all non-constant expressions in the hash table, but retain
728 cselib_preserve_only_values (void)
732 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; i
++)
733 cselib_invalidate_regno (i
, reg_raw_mode
[i
]);
735 cselib_invalidate_mem (callmem
);
737 remove_useless_values ();
739 gcc_assert (first_containing_mem
== &dummy_val
);
742 /* Return the mode in which a register was last set. If X is not a
743 register, return its mode. If the mode in which the register was
744 set is not known, or the value was already clobbered, return
748 cselib_reg_set_mode (const_rtx x
)
753 if (REG_VALUES (REGNO (x
)) == NULL
754 || REG_VALUES (REGNO (x
))->elt
== NULL
)
757 return GET_MODE (REG_VALUES (REGNO (x
))->elt
->val_rtx
);
760 /* Return nonzero if we can prove that X and Y contain the same value, taking
761 our gathered information into account. */
764 rtx_equal_for_cselib_p (rtx x
, rtx y
)
766 return rtx_equal_for_cselib_1 (x
, y
, VOIDmode
);
769 /* If x is a PLUS or an autoinc operation, expand the operation,
770 storing the offset, if any, in *OFF. */
773 autoinc_split (rtx x
, rtx
*off
, enum machine_mode memmode
)
775 switch (GET_CODE (x
))
782 if (memmode
== VOIDmode
)
785 *off
= GEN_INT (-GET_MODE_SIZE (memmode
));
790 if (memmode
== VOIDmode
)
793 *off
= GEN_INT (GET_MODE_SIZE (memmode
));
809 /* Return nonzero if we can prove that X and Y contain the same value,
810 taking our gathered information into account. MEMMODE holds the
811 mode of the enclosing MEM, if any, as required to deal with autoinc
812 addressing modes. If X and Y are not (known to be) part of
813 addresses, MEMMODE should be VOIDmode. */
816 rtx_equal_for_cselib_1 (rtx x
, rtx y
, enum machine_mode memmode
)
822 if (REG_P (x
) || MEM_P (x
))
824 cselib_val
*e
= cselib_lookup (x
, GET_MODE (x
), 0, memmode
);
830 if (REG_P (y
) || MEM_P (y
))
832 cselib_val
*e
= cselib_lookup (y
, GET_MODE (y
), 0, memmode
);
841 if (GET_CODE (x
) == VALUE
)
843 cselib_val
*e
= canonical_cselib_val (CSELIB_VAL_PTR (x
));
844 struct elt_loc_list
*l
;
846 if (GET_CODE (y
) == VALUE
)
847 return e
== canonical_cselib_val (CSELIB_VAL_PTR (y
));
849 for (l
= e
->locs
; l
; l
= l
->next
)
853 /* Avoid infinite recursion. We know we have the canonical
854 value, so we can just skip any values in the equivalence
856 if (REG_P (t
) || MEM_P (t
) || GET_CODE (t
) == VALUE
)
858 else if (rtx_equal_for_cselib_1 (t
, y
, memmode
))
864 else if (GET_CODE (y
) == VALUE
)
866 cselib_val
*e
= canonical_cselib_val (CSELIB_VAL_PTR (y
));
867 struct elt_loc_list
*l
;
869 for (l
= e
->locs
; l
; l
= l
->next
)
873 if (REG_P (t
) || MEM_P (t
) || GET_CODE (t
) == VALUE
)
875 else if (rtx_equal_for_cselib_1 (x
, t
, memmode
))
882 if (GET_MODE (x
) != GET_MODE (y
))
885 if (GET_CODE (x
) != GET_CODE (y
))
887 rtx xorig
= x
, yorig
= y
;
888 rtx xoff
= NULL
, yoff
= NULL
;
890 x
= autoinc_split (x
, &xoff
, memmode
);
891 y
= autoinc_split (y
, &yoff
, memmode
);
896 if (xoff
&& !rtx_equal_for_cselib_1 (xoff
, yoff
, memmode
))
899 /* Don't recurse if nothing changed. */
900 if (x
!= xorig
|| y
!= yorig
)
901 return rtx_equal_for_cselib_1 (x
, y
, memmode
);
906 /* These won't be handled correctly by the code below. */
907 switch (GET_CODE (x
))
914 case DEBUG_IMPLICIT_PTR
:
915 return DEBUG_IMPLICIT_PTR_DECL (x
)
916 == DEBUG_IMPLICIT_PTR_DECL (y
);
918 case DEBUG_PARAMETER_REF
:
919 return DEBUG_PARAMETER_REF_DECL (x
)
920 == DEBUG_PARAMETER_REF_DECL (y
);
923 /* ENTRY_VALUEs are function invariant, it is thus undesirable to
924 use rtx_equal_for_cselib_1 to compare the operands. */
925 return rtx_equal_p (ENTRY_VALUE_EXP (x
), ENTRY_VALUE_EXP (y
));
928 return XEXP (x
, 0) == XEXP (y
, 0);
931 /* We have to compare any autoinc operations in the addresses
932 using this MEM's mode. */
933 return rtx_equal_for_cselib_1 (XEXP (x
, 0), XEXP (y
, 0), GET_MODE (x
));
940 fmt
= GET_RTX_FORMAT (code
);
942 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
949 if (XWINT (x
, i
) != XWINT (y
, i
))
955 if (XINT (x
, i
) != XINT (y
, i
))
961 /* Two vectors must have the same length. */
962 if (XVECLEN (x
, i
) != XVECLEN (y
, i
))
965 /* And the corresponding elements must match. */
966 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
967 if (! rtx_equal_for_cselib_1 (XVECEXP (x
, i
, j
),
968 XVECEXP (y
, i
, j
), memmode
))
974 && targetm
.commutative_p (x
, UNKNOWN
)
975 && rtx_equal_for_cselib_1 (XEXP (x
, 1), XEXP (y
, 0), memmode
)
976 && rtx_equal_for_cselib_1 (XEXP (x
, 0), XEXP (y
, 1), memmode
))
978 if (! rtx_equal_for_cselib_1 (XEXP (x
, i
), XEXP (y
, i
), memmode
))
984 if (strcmp (XSTR (x
, i
), XSTR (y
, i
)))
989 /* These are just backpointers, so they don't matter. */
996 /* It is believed that rtx's at this level will never
997 contain anything but integers and other rtx's,
998 except for within LABEL_REFs and SYMBOL_REFs. */
1006 /* We need to pass down the mode of constants through the hash table
1007 functions. For that purpose, wrap them in a CONST of the appropriate
1010 wrap_constant (enum machine_mode mode
, rtx x
)
1012 if (!CONST_INT_P (x
)
1013 && GET_CODE (x
) != CONST_FIXED
1014 && !CONST_DOUBLE_AS_INT_P (x
))
1016 gcc_assert (mode
!= VOIDmode
);
1017 return gen_rtx_CONST (mode
, x
);
1020 /* Hash an rtx. Return 0 if we couldn't hash the rtx.
1021 For registers and memory locations, we look up their cselib_val structure
1022 and return its VALUE element.
1023 Possible reasons for return 0 are: the object is volatile, or we couldn't
1024 find a register or memory location in the table and CREATE is zero. If
1025 CREATE is nonzero, table elts are created for regs and mem.
1026 N.B. this hash function returns the same hash value for RTXes that
1027 differ only in the order of operands, thus it is suitable for comparisons
1028 that take commutativity into account.
1029 If we wanted to also support associative rules, we'd have to use a different
1030 strategy to avoid returning spurious 0, e.g. return ~(~0U >> 1) .
1031 MEMMODE indicates the mode of an enclosing MEM, and it's only
1032 used to compute autoinc values.
1033 We used to have a MODE argument for hashing for CONST_INTs, but that
1034 didn't make sense, since it caused spurious hash differences between
1035 (set (reg:SI 1) (const_int))
1036 (plus:SI (reg:SI 2) (reg:SI 1))
1038 (plus:SI (reg:SI 2) (const_int))
1039 If the mode is important in any context, it must be checked specifically
1040 in a comparison anyway, since relying on hash differences is unsafe. */
1043 cselib_hash_rtx (rtx x
, int create
, enum machine_mode memmode
)
1049 unsigned int hash
= 0;
1051 code
= GET_CODE (x
);
1052 hash
+= (unsigned) code
+ (unsigned) GET_MODE (x
);
1057 e
= CSELIB_VAL_PTR (x
);
1062 e
= cselib_lookup (x
, GET_MODE (x
), create
, memmode
);
1069 hash
+= ((unsigned) DEBUG_EXPR
<< 7)
1070 + DEBUG_TEMP_UID (DEBUG_EXPR_TREE_DECL (x
));
1071 return hash
? hash
: (unsigned int) DEBUG_EXPR
;
1073 case DEBUG_IMPLICIT_PTR
:
1074 hash
+= ((unsigned) DEBUG_IMPLICIT_PTR
<< 7)
1075 + DECL_UID (DEBUG_IMPLICIT_PTR_DECL (x
));
1076 return hash
? hash
: (unsigned int) DEBUG_IMPLICIT_PTR
;
1078 case DEBUG_PARAMETER_REF
:
1079 hash
+= ((unsigned) DEBUG_PARAMETER_REF
<< 7)
1080 + DECL_UID (DEBUG_PARAMETER_REF_DECL (x
));
1081 return hash
? hash
: (unsigned int) DEBUG_PARAMETER_REF
;
1084 /* ENTRY_VALUEs are function invariant, thus try to avoid
1085 recursing on argument if ENTRY_VALUE is one of the
1086 forms emitted by expand_debug_expr, otherwise
1087 ENTRY_VALUE hash would depend on the current value
1088 in some register or memory. */
1089 if (REG_P (ENTRY_VALUE_EXP (x
)))
1090 hash
+= (unsigned int) REG
1091 + (unsigned int) GET_MODE (ENTRY_VALUE_EXP (x
))
1092 + (unsigned int) REGNO (ENTRY_VALUE_EXP (x
));
1093 else if (MEM_P (ENTRY_VALUE_EXP (x
))
1094 && REG_P (XEXP (ENTRY_VALUE_EXP (x
), 0)))
1095 hash
+= (unsigned int) MEM
1096 + (unsigned int) GET_MODE (XEXP (ENTRY_VALUE_EXP (x
), 0))
1097 + (unsigned int) REGNO (XEXP (ENTRY_VALUE_EXP (x
), 0));
1099 hash
+= cselib_hash_rtx (ENTRY_VALUE_EXP (x
), create
, memmode
);
1100 return hash
? hash
: (unsigned int) ENTRY_VALUE
;
1103 hash
+= ((unsigned) CONST_INT
<< 7) + INTVAL (x
);
1104 return hash
? hash
: (unsigned int) CONST_INT
;
1107 /* This is like the general case, except that it only counts
1108 the integers representing the constant. */
1109 hash
+= (unsigned) code
+ (unsigned) GET_MODE (x
);
1110 if (GET_MODE (x
) != VOIDmode
)
1111 hash
+= real_hash (CONST_DOUBLE_REAL_VALUE (x
));
1113 hash
+= ((unsigned) CONST_DOUBLE_LOW (x
)
1114 + (unsigned) CONST_DOUBLE_HIGH (x
));
1115 return hash
? hash
: (unsigned int) CONST_DOUBLE
;
1118 hash
+= (unsigned int) code
+ (unsigned int) GET_MODE (x
);
1119 hash
+= fixed_hash (CONST_FIXED_VALUE (x
));
1120 return hash
? hash
: (unsigned int) CONST_FIXED
;
1127 units
= CONST_VECTOR_NUNITS (x
);
1129 for (i
= 0; i
< units
; ++i
)
1131 elt
= CONST_VECTOR_ELT (x
, i
);
1132 hash
+= cselib_hash_rtx (elt
, 0, memmode
);
1138 /* Assume there is only one rtx object for any given label. */
1140 /* We don't hash on the address of the CODE_LABEL to avoid bootstrap
1141 differences and differences between each stage's debugging dumps. */
1142 hash
+= (((unsigned int) LABEL_REF
<< 7)
1143 + CODE_LABEL_NUMBER (XEXP (x
, 0)));
1144 return hash
? hash
: (unsigned int) LABEL_REF
;
1148 /* Don't hash on the symbol's address to avoid bootstrap differences.
1149 Different hash values may cause expressions to be recorded in
1150 different orders and thus different registers to be used in the
1151 final assembler. This also avoids differences in the dump files
1152 between various stages. */
1154 const unsigned char *p
= (const unsigned char *) XSTR (x
, 0);
1157 h
+= (h
<< 7) + *p
++; /* ??? revisit */
1159 hash
+= ((unsigned int) SYMBOL_REF
<< 7) + h
;
1160 return hash
? hash
: (unsigned int) SYMBOL_REF
;
1165 /* We can't compute these without knowing the MEM mode. */
1166 gcc_assert (memmode
!= VOIDmode
);
1167 i
= GET_MODE_SIZE (memmode
);
1168 if (code
== PRE_DEC
)
1170 /* Adjust the hash so that (mem:MEMMODE (pre_* (reg))) hashes
1171 like (mem:MEMMODE (plus (reg) (const_int I))). */
1172 hash
+= (unsigned) PLUS
- (unsigned)code
1173 + cselib_hash_rtx (XEXP (x
, 0), create
, memmode
)
1174 + cselib_hash_rtx (GEN_INT (i
), create
, memmode
);
1175 return hash
? hash
: 1 + (unsigned) PLUS
;
1178 gcc_assert (memmode
!= VOIDmode
);
1179 return cselib_hash_rtx (XEXP (x
, 1), create
, memmode
);
1184 gcc_assert (memmode
!= VOIDmode
);
1185 return cselib_hash_rtx (XEXP (x
, 0), create
, memmode
);
1190 case UNSPEC_VOLATILE
:
1194 if (MEM_VOLATILE_P (x
))
1203 i
= GET_RTX_LENGTH (code
) - 1;
1204 fmt
= GET_RTX_FORMAT (code
);
1211 rtx tem
= XEXP (x
, i
);
1212 unsigned int tem_hash
= cselib_hash_rtx (tem
, create
, memmode
);
1221 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
1223 unsigned int tem_hash
1224 = cselib_hash_rtx (XVECEXP (x
, i
, j
), create
, memmode
);
1235 const unsigned char *p
= (const unsigned char *) XSTR (x
, i
);
1244 hash
+= XINT (x
, i
);
1257 return hash
? hash
: 1 + (unsigned int) GET_CODE (x
);
1260 /* Create a new value structure for VALUE and initialize it. The mode of the
1263 static inline cselib_val
*
1264 new_cselib_val (unsigned int hash
, enum machine_mode mode
, rtx x
)
1266 cselib_val
*e
= (cselib_val
*) pool_alloc (cselib_val_pool
);
1269 gcc_assert (next_uid
);
1272 e
->uid
= next_uid
++;
1273 /* We use an alloc pool to allocate this RTL construct because it
1274 accounts for about 8% of the overall memory usage. We know
1275 precisely when we can have VALUE RTXen (when cselib is active)
1276 so we don't need to put them in garbage collected memory.
1277 ??? Why should a VALUE be an RTX in the first place? */
1278 e
->val_rtx
= (rtx
) pool_alloc (value_pool
);
1279 memset (e
->val_rtx
, 0, RTX_HDR_SIZE
);
1280 PUT_CODE (e
->val_rtx
, VALUE
);
1281 PUT_MODE (e
->val_rtx
, mode
);
1282 CSELIB_VAL_PTR (e
->val_rtx
) = e
;
1285 e
->next_containing_mem
= 0;
1287 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1289 fprintf (dump_file
, "cselib value %u:%u ", e
->uid
, hash
);
1290 if (flag_dump_noaddr
|| flag_dump_unnumbered
)
1291 fputs ("# ", dump_file
);
1293 fprintf (dump_file
, "%p ", (void*)e
);
1294 print_rtl_single (dump_file
, x
);
1295 fputc ('\n', dump_file
);
1301 /* ADDR_ELT is a value that is used as address. MEM_ELT is the value that
1302 contains the data at this address. X is a MEM that represents the
1303 value. Update the two value structures to represent this situation. */
1306 add_mem_for_addr (cselib_val
*addr_elt
, cselib_val
*mem_elt
, rtx x
)
1308 struct elt_loc_list
*l
;
1310 addr_elt
= canonical_cselib_val (addr_elt
);
1311 mem_elt
= canonical_cselib_val (mem_elt
);
1313 /* Avoid duplicates. */
1314 for (l
= mem_elt
->locs
; l
; l
= l
->next
)
1316 && CSELIB_VAL_PTR (XEXP (l
->loc
, 0)) == addr_elt
)
1318 promote_debug_loc (l
);
1322 addr_elt
->addr_list
= new_elt_list (addr_elt
->addr_list
, mem_elt
);
1323 new_elt_loc_list (mem_elt
,
1324 replace_equiv_address_nv (x
, addr_elt
->val_rtx
));
1325 if (mem_elt
->next_containing_mem
== NULL
)
1327 mem_elt
->next_containing_mem
= first_containing_mem
;
1328 first_containing_mem
= mem_elt
;
1332 /* Subroutine of cselib_lookup. Return a value for X, which is a MEM rtx.
1333 If CREATE, make a new one if we haven't seen it before. */
1336 cselib_lookup_mem (rtx x
, int create
)
1338 enum machine_mode mode
= GET_MODE (x
);
1339 enum machine_mode addr_mode
;
1342 cselib_val
*mem_elt
;
1345 if (MEM_VOLATILE_P (x
) || mode
== BLKmode
1346 || !cselib_record_memory
1347 || (FLOAT_MODE_P (mode
) && flag_float_store
))
1350 addr_mode
= GET_MODE (XEXP (x
, 0));
1351 if (addr_mode
== VOIDmode
)
1354 /* Look up the value for the address. */
1355 addr
= cselib_lookup (XEXP (x
, 0), addr_mode
, create
, mode
);
1359 addr
= canonical_cselib_val (addr
);
1360 /* Find a value that describes a value of our mode at that address. */
1361 for (l
= addr
->addr_list
; l
; l
= l
->next
)
1362 if (GET_MODE (l
->elt
->val_rtx
) == mode
)
1364 promote_debug_loc (l
->elt
->locs
);
1371 mem_elt
= new_cselib_val (next_uid
, mode
, x
);
1372 add_mem_for_addr (addr
, mem_elt
, x
);
1373 slot
= cselib_find_slot (wrap_constant (mode
, x
), mem_elt
->hash
,
1379 /* Search through the possible substitutions in P. We prefer a non reg
1380 substitution because this allows us to expand the tree further. If
1381 we find, just a reg, take the lowest regno. There may be several
1382 non-reg results, we just take the first one because they will all
1383 expand to the same place. */
1386 expand_loc (struct elt_loc_list
*p
, struct expand_value_data
*evd
,
1389 rtx reg_result
= NULL
;
1390 unsigned int regno
= UINT_MAX
;
1391 struct elt_loc_list
*p_in
= p
;
1393 for (; p
; p
= p
->next
)
1395 /* Return these right away to avoid returning stack pointer based
1396 expressions for frame pointer and vice versa, which is something
1397 that would confuse DSE. See the comment in cselib_expand_value_rtx_1
1398 for more details. */
1400 && (REGNO (p
->loc
) == STACK_POINTER_REGNUM
1401 || REGNO (p
->loc
) == FRAME_POINTER_REGNUM
1402 || REGNO (p
->loc
) == HARD_FRAME_POINTER_REGNUM
1403 || REGNO (p
->loc
) == cfa_base_preserved_regno
))
1405 /* Avoid infinite recursion trying to expand a reg into a
1407 if ((REG_P (p
->loc
))
1408 && (REGNO (p
->loc
) < regno
)
1409 && !bitmap_bit_p (evd
->regs_active
, REGNO (p
->loc
)))
1411 reg_result
= p
->loc
;
1412 regno
= REGNO (p
->loc
);
1414 /* Avoid infinite recursion and do not try to expand the
1416 else if (GET_CODE (p
->loc
) == VALUE
1417 && CSELIB_VAL_PTR (p
->loc
)->locs
== p_in
)
1419 else if (!REG_P (p
->loc
))
1422 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1424 print_inline_rtx (dump_file
, p
->loc
, 0);
1425 fprintf (dump_file
, "\n");
1427 if (GET_CODE (p
->loc
) == LO_SUM
1428 && GET_CODE (XEXP (p
->loc
, 1)) == SYMBOL_REF
1430 && (note
= find_reg_note (p
->setting_insn
, REG_EQUAL
, NULL_RTX
))
1431 && XEXP (note
, 0) == XEXP (p
->loc
, 1))
1432 return XEXP (p
->loc
, 1);
1433 result
= cselib_expand_value_rtx_1 (p
->loc
, evd
, max_depth
- 1);
1440 if (regno
!= UINT_MAX
)
1443 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1444 fprintf (dump_file
, "r%d\n", regno
);
1446 result
= cselib_expand_value_rtx_1 (reg_result
, evd
, max_depth
- 1);
1451 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1455 print_inline_rtx (dump_file
, reg_result
, 0);
1456 fprintf (dump_file
, "\n");
1459 fprintf (dump_file
, "NULL\n");
1465 /* Forward substitute and expand an expression out to its roots.
1466 This is the opposite of common subexpression. Because local value
1467 numbering is such a weak optimization, the expanded expression is
1468 pretty much unique (not from a pointer equals point of view but
1469 from a tree shape point of view.
1471 This function returns NULL if the expansion fails. The expansion
1472 will fail if there is no value number for one of the operands or if
1473 one of the operands has been overwritten between the current insn
1474 and the beginning of the basic block. For instance x has no
1480 REGS_ACTIVE is a scratch bitmap that should be clear when passing in.
1481 It is clear on return. */
1484 cselib_expand_value_rtx (rtx orig
, bitmap regs_active
, int max_depth
)
1486 struct expand_value_data evd
;
1488 evd
.regs_active
= regs_active
;
1489 evd
.callback
= NULL
;
1490 evd
.callback_arg
= NULL
;
1493 return cselib_expand_value_rtx_1 (orig
, &evd
, max_depth
);
1496 /* Same as cselib_expand_value_rtx, but using a callback to try to
1497 resolve some expressions. The CB function should return ORIG if it
1498 can't or does not want to deal with a certain RTX. Any other
1499 return value, including NULL, will be used as the expansion for
1500 VALUE, without any further changes. */
1503 cselib_expand_value_rtx_cb (rtx orig
, bitmap regs_active
, int max_depth
,
1504 cselib_expand_callback cb
, void *data
)
1506 struct expand_value_data evd
;
1508 evd
.regs_active
= regs_active
;
1510 evd
.callback_arg
= data
;
1513 return cselib_expand_value_rtx_1 (orig
, &evd
, max_depth
);
1516 /* Similar to cselib_expand_value_rtx_cb, but no rtxs are actually copied
1517 or simplified. Useful to find out whether cselib_expand_value_rtx_cb
1518 would return NULL or non-NULL, without allocating new rtx. */
1521 cselib_dummy_expand_value_rtx_cb (rtx orig
, bitmap regs_active
, int max_depth
,
1522 cselib_expand_callback cb
, void *data
)
1524 struct expand_value_data evd
;
1526 evd
.regs_active
= regs_active
;
1528 evd
.callback_arg
= data
;
1531 return cselib_expand_value_rtx_1 (orig
, &evd
, max_depth
) != NULL
;
1534 /* Internal implementation of cselib_expand_value_rtx and
1535 cselib_expand_value_rtx_cb. */
1538 cselib_expand_value_rtx_1 (rtx orig
, struct expand_value_data
*evd
,
1544 const char *format_ptr
;
1545 enum machine_mode mode
;
1547 code
= GET_CODE (orig
);
1549 /* For the context of dse, if we end up expand into a huge tree, we
1550 will not have a useful address, so we might as well just give up
1559 struct elt_list
*l
= REG_VALUES (REGNO (orig
));
1561 if (l
&& l
->elt
== NULL
)
1563 for (; l
; l
= l
->next
)
1564 if (GET_MODE (l
->elt
->val_rtx
) == GET_MODE (orig
))
1567 unsigned regno
= REGNO (orig
);
1569 /* The only thing that we are not willing to do (this
1570 is requirement of dse and if others potential uses
1571 need this function we should add a parm to control
1572 it) is that we will not substitute the
1573 STACK_POINTER_REGNUM, FRAME_POINTER or the
1576 These expansions confuses the code that notices that
1577 stores into the frame go dead at the end of the
1578 function and that the frame is not effected by calls
1579 to subroutines. If you allow the
1580 STACK_POINTER_REGNUM substitution, then dse will
1581 think that parameter pushing also goes dead which is
1582 wrong. If you allow the FRAME_POINTER or the
1583 HARD_FRAME_POINTER then you lose the opportunity to
1584 make the frame assumptions. */
1585 if (regno
== STACK_POINTER_REGNUM
1586 || regno
== FRAME_POINTER_REGNUM
1587 || regno
== HARD_FRAME_POINTER_REGNUM
1588 || regno
== cfa_base_preserved_regno
)
1591 bitmap_set_bit (evd
->regs_active
, regno
);
1593 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1594 fprintf (dump_file
, "expanding: r%d into: ", regno
);
1596 result
= expand_loc (l
->elt
->locs
, evd
, max_depth
);
1597 bitmap_clear_bit (evd
->regs_active
, regno
);
1612 /* SCRATCH must be shared because they represent distinct values. */
1615 if (REG_P (XEXP (orig
, 0)) && HARD_REGISTER_NUM_P (REGNO (XEXP (orig
, 0))))
1620 if (shared_const_p (orig
))
1630 subreg
= evd
->callback (orig
, evd
->regs_active
, max_depth
,
1636 subreg
= cselib_expand_value_rtx_1 (SUBREG_REG (orig
), evd
,
1640 scopy
= simplify_gen_subreg (GET_MODE (orig
), subreg
,
1641 GET_MODE (SUBREG_REG (orig
)),
1642 SUBREG_BYTE (orig
));
1644 || (GET_CODE (scopy
) == SUBREG
1645 && !REG_P (SUBREG_REG (scopy
))
1646 && !MEM_P (SUBREG_REG (scopy
))))
1656 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1658 fputs ("\nexpanding ", dump_file
);
1659 print_rtl_single (dump_file
, orig
);
1660 fputs (" into...", dump_file
);
1665 result
= evd
->callback (orig
, evd
->regs_active
, max_depth
,
1672 result
= expand_loc (CSELIB_VAL_PTR (orig
)->locs
, evd
, max_depth
);
1678 return evd
->callback (orig
, evd
->regs_active
, max_depth
,
1686 /* Copy the various flags, fields, and other information. We assume
1687 that all fields need copying, and then clear the fields that should
1688 not be copied. That is the sensible default behavior, and forces
1689 us to explicitly document why we are *not* copying a flag. */
1693 copy
= shallow_copy_rtx (orig
);
1695 format_ptr
= GET_RTX_FORMAT (code
);
1697 for (i
= 0; i
< GET_RTX_LENGTH (code
); i
++)
1698 switch (*format_ptr
++)
1701 if (XEXP (orig
, i
) != NULL
)
1703 rtx result
= cselib_expand_value_rtx_1 (XEXP (orig
, i
), evd
,
1708 XEXP (copy
, i
) = result
;
1714 if (XVEC (orig
, i
) != NULL
)
1717 XVEC (copy
, i
) = rtvec_alloc (XVECLEN (orig
, i
));
1718 for (j
= 0; j
< XVECLEN (orig
, i
); j
++)
1720 rtx result
= cselib_expand_value_rtx_1 (XVECEXP (orig
, i
, j
),
1721 evd
, max_depth
- 1);
1725 XVECEXP (copy
, i
, j
) = result
;
1739 /* These are left unchanged. */
1749 mode
= GET_MODE (copy
);
1750 /* If an operand has been simplified into CONST_INT, which doesn't
1751 have a mode and the mode isn't derivable from whole rtx's mode,
1752 try simplify_*_operation first with mode from original's operand
1753 and as a fallback wrap CONST_INT into gen_rtx_CONST. */
1755 switch (GET_RTX_CLASS (code
))
1758 if (CONST_INT_P (XEXP (copy
, 0))
1759 && GET_MODE (XEXP (orig
, 0)) != VOIDmode
)
1761 scopy
= simplify_unary_operation (code
, mode
, XEXP (copy
, 0),
1762 GET_MODE (XEXP (orig
, 0)));
1767 case RTX_COMM_ARITH
:
1769 /* These expressions can derive operand modes from the whole rtx's mode. */
1772 case RTX_BITFIELD_OPS
:
1773 if (CONST_INT_P (XEXP (copy
, 0))
1774 && GET_MODE (XEXP (orig
, 0)) != VOIDmode
)
1776 scopy
= simplify_ternary_operation (code
, mode
,
1777 GET_MODE (XEXP (orig
, 0)),
1778 XEXP (copy
, 0), XEXP (copy
, 1),
1785 case RTX_COMM_COMPARE
:
1786 if (CONST_INT_P (XEXP (copy
, 0))
1787 && GET_MODE (XEXP (copy
, 1)) == VOIDmode
1788 && (GET_MODE (XEXP (orig
, 0)) != VOIDmode
1789 || GET_MODE (XEXP (orig
, 1)) != VOIDmode
))
1791 scopy
= simplify_relational_operation (code
, mode
,
1792 (GET_MODE (XEXP (orig
, 0))
1794 ? GET_MODE (XEXP (orig
, 0))
1795 : GET_MODE (XEXP (orig
, 1)),
1805 scopy
= simplify_rtx (copy
);
1811 /* Walk rtx X and replace all occurrences of REG and MEM subexpressions
1812 with VALUE expressions. This way, it becomes independent of changes
1813 to registers and memory.
1814 X isn't actually modified; if modifications are needed, new rtl is
1815 allocated. However, the return value can share rtl with X.
1816 If X is within a MEM, MEMMODE must be the mode of the MEM. */
1819 cselib_subst_to_values (rtx x
, enum machine_mode memmode
)
1821 enum rtx_code code
= GET_CODE (x
);
1822 const char *fmt
= GET_RTX_FORMAT (code
);
1831 l
= REG_VALUES (REGNO (x
));
1832 if (l
&& l
->elt
== NULL
)
1834 for (; l
; l
= l
->next
)
1835 if (GET_MODE (l
->elt
->val_rtx
) == GET_MODE (x
))
1836 return l
->elt
->val_rtx
;
1841 e
= cselib_lookup_mem (x
, 0);
1842 /* This used to happen for autoincrements, but we deal with them
1843 properly now. Remove the if stmt for the next release. */
1846 /* Assign a value that doesn't match any other. */
1847 e
= new_cselib_val (next_uid
, GET_MODE (x
), x
);
1852 e
= cselib_lookup (x
, GET_MODE (x
), 0, memmode
);
1862 gcc_assert (memmode
!= VOIDmode
);
1863 i
= GET_MODE_SIZE (memmode
);
1864 if (code
== PRE_DEC
)
1866 return cselib_subst_to_values (plus_constant (GET_MODE (x
),
1871 gcc_assert (memmode
!= VOIDmode
);
1872 return cselib_subst_to_values (XEXP (x
, 1), memmode
);
1877 gcc_assert (memmode
!= VOIDmode
);
1878 return cselib_subst_to_values (XEXP (x
, 0), memmode
);
1884 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
1888 rtx t
= cselib_subst_to_values (XEXP (x
, i
), memmode
);
1890 if (t
!= XEXP (x
, i
))
1893 copy
= shallow_copy_rtx (x
);
1897 else if (fmt
[i
] == 'E')
1901 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
1903 rtx t
= cselib_subst_to_values (XVECEXP (x
, i
, j
), memmode
);
1905 if (t
!= XVECEXP (x
, i
, j
))
1907 if (XVEC (x
, i
) == XVEC (copy
, i
))
1910 copy
= shallow_copy_rtx (x
);
1911 XVEC (copy
, i
) = shallow_copy_rtvec (XVEC (x
, i
));
1913 XVECEXP (copy
, i
, j
) = t
;
1922 /* Wrapper for cselib_subst_to_values, that indicates X is in INSN. */
1925 cselib_subst_to_values_from_insn (rtx x
, enum machine_mode memmode
, rtx insn
)
1928 gcc_assert (!cselib_current_insn
);
1929 cselib_current_insn
= insn
;
1930 ret
= cselib_subst_to_values (x
, memmode
);
1931 cselib_current_insn
= NULL
;
1935 /* Look up the rtl expression X in our tables and return the value it
1936 has. If CREATE is zero, we return NULL if we don't know the value.
1937 Otherwise, we create a new one if possible, using mode MODE if X
1938 doesn't have a mode (i.e. because it's a constant). When X is part
1939 of an address, MEMMODE should be the mode of the enclosing MEM if
1940 we're tracking autoinc expressions. */
1943 cselib_lookup_1 (rtx x
, enum machine_mode mode
,
1944 int create
, enum machine_mode memmode
)
1948 unsigned int hashval
;
1950 if (GET_MODE (x
) != VOIDmode
)
1951 mode
= GET_MODE (x
);
1953 if (GET_CODE (x
) == VALUE
)
1954 return CSELIB_VAL_PTR (x
);
1959 unsigned int i
= REGNO (x
);
1962 if (l
&& l
->elt
== NULL
)
1964 for (; l
; l
= l
->next
)
1965 if (mode
== GET_MODE (l
->elt
->val_rtx
))
1967 promote_debug_loc (l
->elt
->locs
);
1974 if (i
< FIRST_PSEUDO_REGISTER
)
1976 unsigned int n
= hard_regno_nregs
[i
][mode
];
1978 if (n
> max_value_regs
)
1982 e
= new_cselib_val (next_uid
, GET_MODE (x
), x
);
1983 new_elt_loc_list (e
, x
);
1984 if (REG_VALUES (i
) == 0)
1986 /* Maintain the invariant that the first entry of
1987 REG_VALUES, if present, must be the value used to set the
1988 register, or NULL. */
1989 used_regs
[n_used_regs
++] = i
;
1990 REG_VALUES (i
) = new_elt_list (REG_VALUES (i
), NULL
);
1992 else if (cselib_preserve_constants
1993 && GET_MODE_CLASS (mode
) == MODE_INT
)
1995 /* During var-tracking, try harder to find equivalences
1996 for SUBREGs. If a setter sets say a DImode register
1997 and user uses that register only in SImode, add a lowpart
1999 struct elt_list
*lwider
= NULL
;
2001 if (l
&& l
->elt
== NULL
)
2003 for (; l
; l
= l
->next
)
2004 if (GET_MODE_CLASS (GET_MODE (l
->elt
->val_rtx
)) == MODE_INT
2005 && GET_MODE_SIZE (GET_MODE (l
->elt
->val_rtx
))
2006 > GET_MODE_SIZE (mode
)
2008 || GET_MODE_SIZE (GET_MODE (l
->elt
->val_rtx
))
2009 < GET_MODE_SIZE (GET_MODE (lwider
->elt
->val_rtx
))))
2011 struct elt_loc_list
*el
;
2012 if (i
< FIRST_PSEUDO_REGISTER
2013 && hard_regno_nregs
[i
][GET_MODE (l
->elt
->val_rtx
)] != 1)
2015 for (el
= l
->elt
->locs
; el
; el
= el
->next
)
2016 if (!REG_P (el
->loc
))
2023 rtx sub
= lowpart_subreg (mode
, lwider
->elt
->val_rtx
,
2024 GET_MODE (lwider
->elt
->val_rtx
));
2026 new_elt_loc_list (e
, sub
);
2029 REG_VALUES (i
)->next
= new_elt_list (REG_VALUES (i
)->next
, e
);
2030 slot
= cselib_find_slot (x
, e
->hash
, INSERT
, memmode
);
2036 return cselib_lookup_mem (x
, create
);
2038 hashval
= cselib_hash_rtx (x
, create
, memmode
);
2039 /* Can't even create if hashing is not possible. */
2043 slot
= cselib_find_slot (wrap_constant (mode
, x
), hashval
,
2044 create
? INSERT
: NO_INSERT
, memmode
);
2048 e
= (cselib_val
*) *slot
;
2052 e
= new_cselib_val (hashval
, mode
, x
);
2054 /* We have to fill the slot before calling cselib_subst_to_values:
2055 the hash table is inconsistent until we do so, and
2056 cselib_subst_to_values will need to do lookups. */
2058 new_elt_loc_list (e
, cselib_subst_to_values (x
, memmode
));
2062 /* Wrapper for cselib_lookup, that indicates X is in INSN. */
2065 cselib_lookup_from_insn (rtx x
, enum machine_mode mode
,
2066 int create
, enum machine_mode memmode
, rtx insn
)
2070 gcc_assert (!cselib_current_insn
);
2071 cselib_current_insn
= insn
;
2073 ret
= cselib_lookup (x
, mode
, create
, memmode
);
2075 cselib_current_insn
= NULL
;
2080 /* Wrapper for cselib_lookup_1, that logs the lookup result and
2081 maintains invariants related with debug insns. */
2084 cselib_lookup (rtx x
, enum machine_mode mode
,
2085 int create
, enum machine_mode memmode
)
2087 cselib_val
*ret
= cselib_lookup_1 (x
, mode
, create
, memmode
);
2089 /* ??? Should we return NULL if we're not to create an entry, the
2090 found loc is a debug loc and cselib_current_insn is not DEBUG?
2091 If so, we should also avoid converting val to non-DEBUG; probably
2092 easiest setting cselib_current_insn to NULL before the call
2095 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
2097 fputs ("cselib lookup ", dump_file
);
2098 print_inline_rtx (dump_file
, x
, 2);
2099 fprintf (dump_file
, " => %u:%u\n",
2101 ret
? ret
->hash
: 0);
2107 /* Invalidate any entries in reg_values that overlap REGNO. This is called
2108 if REGNO is changing. MODE is the mode of the assignment to REGNO, which
2109 is used to determine how many hard registers are being changed. If MODE
2110 is VOIDmode, then only REGNO is being changed; this is used when
2111 invalidating call clobbered registers across a call. */
2114 cselib_invalidate_regno (unsigned int regno
, enum machine_mode mode
)
2116 unsigned int endregno
;
2119 /* If we see pseudos after reload, something is _wrong_. */
2120 gcc_assert (!reload_completed
|| regno
< FIRST_PSEUDO_REGISTER
2121 || reg_renumber
[regno
] < 0);
2123 /* Determine the range of registers that must be invalidated. For
2124 pseudos, only REGNO is affected. For hard regs, we must take MODE
2125 into account, and we must also invalidate lower register numbers
2126 if they contain values that overlap REGNO. */
2127 if (regno
< FIRST_PSEUDO_REGISTER
)
2129 gcc_assert (mode
!= VOIDmode
);
2131 if (regno
< max_value_regs
)
2134 i
= regno
- max_value_regs
;
2136 endregno
= end_hard_regno (mode
, regno
);
2141 endregno
= regno
+ 1;
2144 for (; i
< endregno
; i
++)
2146 struct elt_list
**l
= ®_VALUES (i
);
2148 /* Go through all known values for this reg; if it overlaps the range
2149 we're invalidating, remove the value. */
2152 cselib_val
*v
= (*l
)->elt
;
2155 struct elt_loc_list
**p
;
2156 unsigned int this_last
= i
;
2158 if (i
< FIRST_PSEUDO_REGISTER
&& v
!= NULL
)
2159 this_last
= end_hard_regno (GET_MODE (v
->val_rtx
), i
) - 1;
2161 if (this_last
< regno
|| v
== NULL
2162 || (v
== cfa_base_preserved_val
2163 && i
== cfa_base_preserved_regno
))
2169 /* We have an overlap. */
2170 if (*l
== REG_VALUES (i
))
2172 /* Maintain the invariant that the first entry of
2173 REG_VALUES, if present, must be the value used to set
2174 the register, or NULL. This is also nice because
2175 then we won't push the same regno onto user_regs
2181 unchain_one_elt_list (l
);
2183 v
= canonical_cselib_val (v
);
2185 had_locs
= v
->locs
!= NULL
;
2186 setting_insn
= v
->locs
? v
->locs
->setting_insn
: NULL
;
2188 /* Now, we clear the mapping from value to reg. It must exist, so
2189 this code will crash intentionally if it doesn't. */
2190 for (p
= &v
->locs
; ; p
= &(*p
)->next
)
2194 if (REG_P (x
) && REGNO (x
) == i
)
2196 unchain_one_elt_loc_list (p
);
2201 if (had_locs
&& v
->locs
== 0 && !PRESERVED_VALUE_P (v
->val_rtx
))
2203 if (setting_insn
&& DEBUG_INSN_P (setting_insn
))
2204 n_useless_debug_values
++;
2212 /* Invalidate any locations in the table which are changed because of a
2213 store to MEM_RTX. If this is called because of a non-const call
2214 instruction, MEM_RTX is (mem:BLK const0_rtx). */
2217 cselib_invalidate_mem (rtx mem_rtx
)
2219 cselib_val
**vp
, *v
, *next
;
2223 mem_addr
= canon_rtx (get_addr (XEXP (mem_rtx
, 0)));
2224 mem_rtx
= canon_rtx (mem_rtx
);
2226 vp
= &first_containing_mem
;
2227 for (v
= *vp
; v
!= &dummy_val
; v
= next
)
2229 bool has_mem
= false;
2230 struct elt_loc_list
**p
= &v
->locs
;
2231 bool had_locs
= v
->locs
!= NULL
;
2232 rtx setting_insn
= v
->locs
? v
->locs
->setting_insn
: NULL
;
2238 struct elt_list
**mem_chain
;
2240 /* MEMs may occur in locations only at the top level; below
2241 that every MEM or REG is substituted by its VALUE. */
2247 if (num_mems
< PARAM_VALUE (PARAM_MAX_CSELIB_MEMORY_LOCATIONS
)
2248 && ! canon_true_dependence (mem_rtx
, GET_MODE (mem_rtx
),
2249 mem_addr
, x
, NULL_RTX
))
2257 /* This one overlaps. */
2258 /* We must have a mapping from this MEM's address to the
2259 value (E). Remove that, too. */
2260 addr
= cselib_lookup (XEXP (x
, 0), VOIDmode
, 0, GET_MODE (x
));
2261 addr
= canonical_cselib_val (addr
);
2262 gcc_checking_assert (v
== canonical_cselib_val (v
));
2263 mem_chain
= &addr
->addr_list
;
2266 cselib_val
*canon
= canonical_cselib_val ((*mem_chain
)->elt
);
2270 unchain_one_elt_list (mem_chain
);
2274 /* Record canonicalized elt. */
2275 (*mem_chain
)->elt
= canon
;
2277 mem_chain
= &(*mem_chain
)->next
;
2280 unchain_one_elt_loc_list (p
);
2283 if (had_locs
&& v
->locs
== 0 && !PRESERVED_VALUE_P (v
->val_rtx
))
2285 if (setting_insn
&& DEBUG_INSN_P (setting_insn
))
2286 n_useless_debug_values
++;
2291 next
= v
->next_containing_mem
;
2295 vp
= &(*vp
)->next_containing_mem
;
2298 v
->next_containing_mem
= NULL
;
2303 /* Invalidate DEST, which is being assigned to or clobbered. */
2306 cselib_invalidate_rtx (rtx dest
)
2308 while (GET_CODE (dest
) == SUBREG
2309 || GET_CODE (dest
) == ZERO_EXTRACT
2310 || GET_CODE (dest
) == STRICT_LOW_PART
)
2311 dest
= XEXP (dest
, 0);
2314 cselib_invalidate_regno (REGNO (dest
), GET_MODE (dest
));
2315 else if (MEM_P (dest
))
2316 cselib_invalidate_mem (dest
);
2319 /* A wrapper for cselib_invalidate_rtx to be called via note_stores. */
2322 cselib_invalidate_rtx_note_stores (rtx dest
, const_rtx ignore ATTRIBUTE_UNUSED
,
2323 void *data ATTRIBUTE_UNUSED
)
2325 cselib_invalidate_rtx (dest
);
2328 /* Record the result of a SET instruction. DEST is being set; the source
2329 contains the value described by SRC_ELT. If DEST is a MEM, DEST_ADDR_ELT
2330 describes its address. */
2333 cselib_record_set (rtx dest
, cselib_val
*src_elt
, cselib_val
*dest_addr_elt
)
2335 int dreg
= REG_P (dest
) ? (int) REGNO (dest
) : -1;
2337 if (src_elt
== 0 || side_effects_p (dest
))
2342 if (dreg
< FIRST_PSEUDO_REGISTER
)
2344 unsigned int n
= hard_regno_nregs
[dreg
][GET_MODE (dest
)];
2346 if (n
> max_value_regs
)
2350 if (REG_VALUES (dreg
) == 0)
2352 used_regs
[n_used_regs
++] = dreg
;
2353 REG_VALUES (dreg
) = new_elt_list (REG_VALUES (dreg
), src_elt
);
2357 /* The register should have been invalidated. */
2358 gcc_assert (REG_VALUES (dreg
)->elt
== 0);
2359 REG_VALUES (dreg
)->elt
= src_elt
;
2362 if (src_elt
->locs
== 0 && !PRESERVED_VALUE_P (src_elt
->val_rtx
))
2364 new_elt_loc_list (src_elt
, dest
);
2366 else if (MEM_P (dest
) && dest_addr_elt
!= 0
2367 && cselib_record_memory
)
2369 if (src_elt
->locs
== 0 && !PRESERVED_VALUE_P (src_elt
->val_rtx
))
2371 add_mem_for_addr (dest_addr_elt
, src_elt
, dest
);
2375 /* Make ELT and X's VALUE equivalent to each other at INSN. */
2378 cselib_add_permanent_equiv (cselib_val
*elt
, rtx x
, rtx insn
)
2381 rtx save_cselib_current_insn
= cselib_current_insn
;
2383 gcc_checking_assert (elt
);
2384 gcc_checking_assert (PRESERVED_VALUE_P (elt
->val_rtx
));
2385 gcc_checking_assert (!side_effects_p (x
));
2387 cselib_current_insn
= insn
;
2389 nelt
= cselib_lookup (x
, GET_MODE (elt
->val_rtx
), 1, VOIDmode
);
2393 cselib_any_perm_equivs
= true;
2395 if (!PRESERVED_VALUE_P (nelt
->val_rtx
))
2396 cselib_preserve_value (nelt
);
2398 new_elt_loc_list (nelt
, elt
->val_rtx
);
2401 cselib_current_insn
= save_cselib_current_insn
;
2404 /* Return TRUE if any permanent equivalences have been recorded since
2405 the table was last initialized. */
2407 cselib_have_permanent_equivalences (void)
2409 return cselib_any_perm_equivs
;
2412 /* There is no good way to determine how many elements there can be
2413 in a PARALLEL. Since it's fairly cheap, use a really large number. */
2414 #define MAX_SETS (FIRST_PSEUDO_REGISTER * 2)
2416 struct cselib_record_autoinc_data
2418 struct cselib_set
*sets
;
2422 /* Callback for for_each_inc_dec. Records in ARG the SETs implied by
2423 autoinc RTXs: SRC plus SRCOFF if non-NULL is stored in DEST. */
2426 cselib_record_autoinc_cb (rtx mem ATTRIBUTE_UNUSED
, rtx op ATTRIBUTE_UNUSED
,
2427 rtx dest
, rtx src
, rtx srcoff
, void *arg
)
2429 struct cselib_record_autoinc_data
*data
;
2430 data
= (struct cselib_record_autoinc_data
*)arg
;
2432 data
->sets
[data
->n_sets
].dest
= dest
;
2435 data
->sets
[data
->n_sets
].src
= gen_rtx_PLUS (GET_MODE (src
), src
, srcoff
);
2437 data
->sets
[data
->n_sets
].src
= src
;
2444 /* Record the effects of any sets and autoincs in INSN. */
2446 cselib_record_sets (rtx insn
)
2450 struct cselib_set sets
[MAX_SETS
];
2451 rtx body
= PATTERN (insn
);
2453 int n_sets_before_autoinc
;
2454 struct cselib_record_autoinc_data data
;
2456 body
= PATTERN (insn
);
2457 if (GET_CODE (body
) == COND_EXEC
)
2459 cond
= COND_EXEC_TEST (body
);
2460 body
= COND_EXEC_CODE (body
);
2463 /* Find all sets. */
2464 if (GET_CODE (body
) == SET
)
2466 sets
[0].src
= SET_SRC (body
);
2467 sets
[0].dest
= SET_DEST (body
);
2470 else if (GET_CODE (body
) == PARALLEL
)
2472 /* Look through the PARALLEL and record the values being
2473 set, if possible. Also handle any CLOBBERs. */
2474 for (i
= XVECLEN (body
, 0) - 1; i
>= 0; --i
)
2476 rtx x
= XVECEXP (body
, 0, i
);
2478 if (GET_CODE (x
) == SET
)
2480 sets
[n_sets
].src
= SET_SRC (x
);
2481 sets
[n_sets
].dest
= SET_DEST (x
);
2488 && MEM_P (sets
[0].src
)
2489 && !cselib_record_memory
2490 && MEM_READONLY_P (sets
[0].src
))
2492 rtx note
= find_reg_equal_equiv_note (insn
);
2494 if (note
&& CONSTANT_P (XEXP (note
, 0)))
2495 sets
[0].src
= XEXP (note
, 0);
2499 data
.n_sets
= n_sets_before_autoinc
= n_sets
;
2500 for_each_inc_dec (&insn
, cselib_record_autoinc_cb
, &data
);
2501 n_sets
= data
.n_sets
;
2503 /* Look up the values that are read. Do this before invalidating the
2504 locations that are written. */
2505 for (i
= 0; i
< n_sets
; i
++)
2507 rtx dest
= sets
[i
].dest
;
2509 /* A STRICT_LOW_PART can be ignored; we'll record the equivalence for
2510 the low part after invalidating any knowledge about larger modes. */
2511 if (GET_CODE (sets
[i
].dest
) == STRICT_LOW_PART
)
2512 sets
[i
].dest
= dest
= XEXP (dest
, 0);
2514 /* We don't know how to record anything but REG or MEM. */
2516 || (MEM_P (dest
) && cselib_record_memory
))
2518 rtx src
= sets
[i
].src
;
2520 src
= gen_rtx_IF_THEN_ELSE (GET_MODE (dest
), cond
, src
, dest
);
2521 sets
[i
].src_elt
= cselib_lookup (src
, GET_MODE (dest
), 1, VOIDmode
);
2524 enum machine_mode address_mode
= get_address_mode (dest
);
2526 sets
[i
].dest_addr_elt
= cselib_lookup (XEXP (dest
, 0),
2531 sets
[i
].dest_addr_elt
= 0;
2535 if (cselib_record_sets_hook
)
2536 cselib_record_sets_hook (insn
, sets
, n_sets
);
2538 /* Invalidate all locations written by this insn. Note that the elts we
2539 looked up in the previous loop aren't affected, just some of their
2540 locations may go away. */
2541 note_stores (body
, cselib_invalidate_rtx_note_stores
, NULL
);
2543 for (i
= n_sets_before_autoinc
; i
< n_sets
; i
++)
2544 cselib_invalidate_rtx (sets
[i
].dest
);
2546 /* If this is an asm, look for duplicate sets. This can happen when the
2547 user uses the same value as an output multiple times. This is valid
2548 if the outputs are not actually used thereafter. Treat this case as
2549 if the value isn't actually set. We do this by smashing the destination
2550 to pc_rtx, so that we won't record the value later. */
2551 if (n_sets
>= 2 && asm_noperands (body
) >= 0)
2553 for (i
= 0; i
< n_sets
; i
++)
2555 rtx dest
= sets
[i
].dest
;
2556 if (REG_P (dest
) || MEM_P (dest
))
2559 for (j
= i
+ 1; j
< n_sets
; j
++)
2560 if (rtx_equal_p (dest
, sets
[j
].dest
))
2562 sets
[i
].dest
= pc_rtx
;
2563 sets
[j
].dest
= pc_rtx
;
2569 /* Now enter the equivalences in our tables. */
2570 for (i
= 0; i
< n_sets
; i
++)
2572 rtx dest
= sets
[i
].dest
;
2574 || (MEM_P (dest
) && cselib_record_memory
))
2575 cselib_record_set (dest
, sets
[i
].src_elt
, sets
[i
].dest_addr_elt
);
2579 /* Record the effects of INSN. */
2582 cselib_process_insn (rtx insn
)
2587 cselib_current_insn
= insn
;
2589 /* Forget everything at a CODE_LABEL, a volatile asm, or a setjmp. */
2592 && find_reg_note (insn
, REG_SETJMP
, NULL
))
2593 || (NONJUMP_INSN_P (insn
)
2594 && GET_CODE (PATTERN (insn
)) == ASM_OPERANDS
2595 && MEM_VOLATILE_P (PATTERN (insn
))))
2597 cselib_reset_table (next_uid
);
2598 cselib_current_insn
= NULL_RTX
;
2602 if (! INSN_P (insn
))
2604 cselib_current_insn
= NULL_RTX
;
2608 /* If this is a call instruction, forget anything stored in a
2609 call clobbered register, or, if this is not a const call, in
2613 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; i
++)
2614 if (call_used_regs
[i
]
2615 || (REG_VALUES (i
) && REG_VALUES (i
)->elt
2616 && HARD_REGNO_CALL_PART_CLOBBERED (i
,
2617 GET_MODE (REG_VALUES (i
)->elt
->val_rtx
))))
2618 cselib_invalidate_regno (i
, reg_raw_mode
[i
]);
2620 /* Since it is not clear how cselib is going to be used, be
2621 conservative here and treat looping pure or const functions
2622 as if they were regular functions. */
2623 if (RTL_LOOPING_CONST_OR_PURE_CALL_P (insn
)
2624 || !(RTL_CONST_OR_PURE_CALL_P (insn
)))
2625 cselib_invalidate_mem (callmem
);
2628 cselib_record_sets (insn
);
2630 /* Look for any CLOBBERs in CALL_INSN_FUNCTION_USAGE, but only
2631 after we have processed the insn. */
2633 for (x
= CALL_INSN_FUNCTION_USAGE (insn
); x
; x
= XEXP (x
, 1))
2634 if (GET_CODE (XEXP (x
, 0)) == CLOBBER
)
2635 cselib_invalidate_rtx (XEXP (XEXP (x
, 0), 0));
2637 cselib_current_insn
= NULL_RTX
;
2639 if (n_useless_values
> MAX_USELESS_VALUES
2640 /* remove_useless_values is linear in the hash table size. Avoid
2641 quadratic behavior for very large hashtables with very few
2642 useless elements. */
2643 && ((unsigned int)n_useless_values
2644 > (cselib_hash_table
->n_elements
2645 - cselib_hash_table
->n_deleted
2646 - n_debug_values
) / 4))
2647 remove_useless_values ();
2650 /* Initialize cselib for one pass. The caller must also call
2651 init_alias_analysis. */
2654 cselib_init (int record_what
)
2656 elt_list_pool
= create_alloc_pool ("elt_list",
2657 sizeof (struct elt_list
), 10);
2658 elt_loc_list_pool
= create_alloc_pool ("elt_loc_list",
2659 sizeof (struct elt_loc_list
), 10);
2660 cselib_val_pool
= create_alloc_pool ("cselib_val_list",
2661 sizeof (cselib_val
), 10);
2662 value_pool
= create_alloc_pool ("value", RTX_CODE_SIZE (VALUE
), 100);
2663 cselib_record_memory
= record_what
& CSELIB_RECORD_MEMORY
;
2664 cselib_preserve_constants
= record_what
& CSELIB_PRESERVE_CONSTANTS
;
2665 cselib_any_perm_equivs
= false;
2667 /* (mem:BLK (scratch)) is a special mechanism to conflict with everything,
2668 see canon_true_dependence. This is only created once. */
2670 callmem
= gen_rtx_MEM (BLKmode
, gen_rtx_SCRATCH (VOIDmode
));
2672 cselib_nregs
= max_reg_num ();
2674 /* We preserve reg_values to allow expensive clearing of the whole thing.
2675 Reallocate it however if it happens to be too large. */
2676 if (!reg_values
|| reg_values_size
< cselib_nregs
2677 || (reg_values_size
> 10 && reg_values_size
> cselib_nregs
* 4))
2680 /* Some space for newly emit instructions so we don't end up
2681 reallocating in between passes. */
2682 reg_values_size
= cselib_nregs
+ (63 + cselib_nregs
) / 16;
2683 reg_values
= XCNEWVEC (struct elt_list
*, reg_values_size
);
2685 used_regs
= XNEWVEC (unsigned int, cselib_nregs
);
2687 cselib_hash_table
= htab_create (31, get_value_hash
,
2688 entry_and_rtx_equal_p
, NULL
);
2692 /* Called when the current user is done with cselib. */
2695 cselib_finish (void)
2697 cselib_discard_hook
= NULL
;
2698 cselib_preserve_constants
= false;
2699 cselib_any_perm_equivs
= false;
2700 cfa_base_preserved_val
= NULL
;
2701 cfa_base_preserved_regno
= INVALID_REGNUM
;
2702 free_alloc_pool (elt_list_pool
);
2703 free_alloc_pool (elt_loc_list_pool
);
2704 free_alloc_pool (cselib_val_pool
);
2705 free_alloc_pool (value_pool
);
2706 cselib_clear_table ();
2707 htab_delete (cselib_hash_table
);
2710 cselib_hash_table
= 0;
2711 n_useless_values
= 0;
2712 n_useless_debug_values
= 0;
2717 /* Dump the cselib_val *X to FILE *info. */
2720 dump_cselib_val (void **x
, void *info
)
2722 cselib_val
*v
= (cselib_val
*)*x
;
2723 FILE *out
= (FILE *)info
;
2724 bool need_lf
= true;
2726 print_inline_rtx (out
, v
->val_rtx
, 0);
2730 struct elt_loc_list
*l
= v
->locs
;
2736 fputs (" locs:", out
);
2739 if (l
->setting_insn
)
2740 fprintf (out
, "\n from insn %i ",
2741 INSN_UID (l
->setting_insn
));
2743 fprintf (out
, "\n ");
2744 print_inline_rtx (out
, l
->loc
, 4);
2746 while ((l
= l
->next
));
2751 fputs (" no locs", out
);
2757 struct elt_list
*e
= v
->addr_list
;
2763 fputs (" addr list:", out
);
2767 print_inline_rtx (out
, e
->elt
->val_rtx
, 2);
2769 while ((e
= e
->next
));
2774 fputs (" no addrs", out
);
2778 if (v
->next_containing_mem
== &dummy_val
)
2779 fputs (" last mem\n", out
);
2780 else if (v
->next_containing_mem
)
2782 fputs (" next mem ", out
);
2783 print_inline_rtx (out
, v
->next_containing_mem
->val_rtx
, 2);
2792 /* Dump to OUT everything in the CSELIB table. */
2795 dump_cselib_table (FILE *out
)
2797 fprintf (out
, "cselib hash table:\n");
2798 htab_traverse (cselib_hash_table
, dump_cselib_val
, out
);
2799 if (first_containing_mem
!= &dummy_val
)
2801 fputs ("first mem ", out
);
2802 print_inline_rtx (out
, first_containing_mem
->val_rtx
, 2);
2805 fprintf (out
, "next uid %i\n", next_uid
);
2808 #include "gt-cselib.h"