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"
30 #include "hard-reg-set.h"
32 #include "insn-config.h"
36 #include "diagnostic-core.h"
40 #include "tree-pass.h"
43 #include "alloc-pool.h"
47 /* A list of cselib_val structures. */
49 struct elt_list
*next
;
53 static bool cselib_record_memory
;
54 static bool cselib_preserve_constants
;
55 static bool cselib_any_perm_equivs
;
56 static int entry_and_rtx_equal_p (const void *, const void *);
57 static hashval_t
get_value_hash (const void *);
58 static struct elt_list
*new_elt_list (struct elt_list
*, cselib_val
*);
59 static void new_elt_loc_list (cselib_val
*, rtx
);
60 static void unchain_one_value (cselib_val
*);
61 static void unchain_one_elt_list (struct elt_list
**);
62 static void unchain_one_elt_loc_list (struct elt_loc_list
**);
63 static int discard_useless_locs (void **, void *);
64 static int discard_useless_values (void **, void *);
65 static void remove_useless_values (void);
66 static int rtx_equal_for_cselib_1 (rtx
, rtx
, enum machine_mode
);
67 static unsigned int cselib_hash_rtx (rtx
, int, enum machine_mode
);
68 static cselib_val
*new_cselib_val (unsigned int, enum machine_mode
, rtx
);
69 static void add_mem_for_addr (cselib_val
*, cselib_val
*, rtx
);
70 static cselib_val
*cselib_lookup_mem (rtx
, int);
71 static void cselib_invalidate_regno (unsigned int, enum machine_mode
);
72 static void cselib_invalidate_mem (rtx
);
73 static void cselib_record_set (rtx
, cselib_val
*, cselib_val
*);
74 static void cselib_record_sets (rtx
);
76 struct expand_value_data
79 cselib_expand_callback callback
;
84 static rtx
cselib_expand_value_rtx_1 (rtx
, struct expand_value_data
*, int);
86 /* There are three ways in which cselib can look up an rtx:
87 - for a REG, the reg_values table (which is indexed by regno) is used
88 - for a MEM, we recursively look up its address and then follow the
89 addr_list of that value
90 - for everything else, we compute a hash value and go through the hash
91 table. Since different rtx's can still have the same hash value,
92 this involves walking the table entries for a given value and comparing
93 the locations of the entries with the rtx we are looking up. */
95 /* A table that enables us to look up elts by their value. */
96 static htab_t cselib_hash_table
;
98 /* This is a global so we don't have to pass this through every function.
99 It is used in new_elt_loc_list to set SETTING_INSN. */
100 static rtx cselib_current_insn
;
102 /* The unique id that the next create value will take. */
103 static unsigned int next_uid
;
105 /* The number of registers we had when the varrays were last resized. */
106 static unsigned int cselib_nregs
;
108 /* Count values without known locations, or with only locations that
109 wouldn't have been known except for debug insns. Whenever this
110 grows too big, we remove these useless values from the table.
112 Counting values with only debug values is a bit tricky. We don't
113 want to increment n_useless_values when we create a value for a
114 debug insn, for this would get n_useless_values out of sync, but we
115 want increment it if all locs in the list that were ever referenced
116 in nondebug insns are removed from the list.
118 In the general case, once we do that, we'd have to stop accepting
119 nondebug expressions in the loc list, to avoid having two values
120 equivalent that, without debug insns, would have been made into
121 separate values. However, because debug insns never introduce
122 equivalences themselves (no assignments), the only means for
123 growing loc lists is through nondebug assignments. If the locs
124 also happen to be referenced in debug insns, it will work just fine.
126 A consequence of this is that there's at most one debug-only loc in
127 each loc list. If we keep it in the first entry, testing whether
128 we have a debug-only loc list takes O(1).
130 Furthermore, since any additional entry in a loc list containing a
131 debug loc would have to come from an assignment (nondebug) that
132 references both the initial debug loc and the newly-equivalent loc,
133 the initial debug loc would be promoted to a nondebug loc, and the
134 loc list would not contain debug locs any more.
136 So the only case we have to be careful with in order to keep
137 n_useless_values in sync between debug and nondebug compilations is
138 to avoid incrementing n_useless_values when removing the single loc
139 from a value that turns out to not appear outside debug values. We
140 increment n_useless_debug_values instead, and leave such values
141 alone until, for other reasons, we garbage-collect useless
143 static int n_useless_values
;
144 static int n_useless_debug_values
;
146 /* Count values whose locs have been taken exclusively from debug
147 insns for the entire life of the value. */
148 static int n_debug_values
;
150 /* Number of useless values before we remove them from the hash table. */
151 #define MAX_USELESS_VALUES 32
153 /* This table maps from register number to values. It does not
154 contain pointers to cselib_val structures, but rather elt_lists.
155 The purpose is to be able to refer to the same register in
156 different modes. The first element of the list defines the mode in
157 which the register was set; if the mode is unknown or the value is
158 no longer valid in that mode, ELT will be NULL for the first
160 static struct elt_list
**reg_values
;
161 static unsigned int reg_values_size
;
162 #define REG_VALUES(i) reg_values[i]
164 /* The largest number of hard regs used by any entry added to the
165 REG_VALUES table. Cleared on each cselib_clear_table() invocation. */
166 static unsigned int max_value_regs
;
168 /* Here the set of indices I with REG_VALUES(I) != 0 is saved. This is used
169 in cselib_clear_table() for fast emptying. */
170 static unsigned int *used_regs
;
171 static unsigned int n_used_regs
;
173 /* We pass this to cselib_invalidate_mem to invalidate all of
174 memory for a non-const call instruction. */
175 static GTY(()) rtx callmem
;
177 /* Set by discard_useless_locs if it deleted the last location of any
179 static int values_became_useless
;
181 /* Used as stop element of the containing_mem list so we can check
182 presence in the list by checking the next pointer. */
183 static cselib_val dummy_val
;
185 /* If non-NULL, value of the eliminated arg_pointer_rtx or frame_pointer_rtx
186 that is constant through the whole function and should never be
188 static cselib_val
*cfa_base_preserved_val
;
189 static unsigned int cfa_base_preserved_regno
= INVALID_REGNUM
;
191 /* Used to list all values that contain memory reference.
192 May or may not contain the useless values - the list is compacted
193 each time memory is invalidated. */
194 static cselib_val
*first_containing_mem
= &dummy_val
;
195 static alloc_pool elt_loc_list_pool
, elt_list_pool
, cselib_val_pool
, value_pool
;
197 /* If nonnull, cselib will call this function before freeing useless
198 VALUEs. A VALUE is deemed useless if its "locs" field is null. */
199 void (*cselib_discard_hook
) (cselib_val
*);
201 /* If nonnull, cselib will call this function before recording sets or
202 even clobbering outputs of INSN. All the recorded sets will be
203 represented in the array sets[n_sets]. new_val_min can be used to
204 tell whether values present in sets are introduced by this
206 void (*cselib_record_sets_hook
) (rtx insn
, struct cselib_set
*sets
,
209 #define PRESERVED_VALUE_P(RTX) \
210 (RTL_FLAG_CHECK1("PRESERVED_VALUE_P", (RTX), VALUE)->unchanging)
214 /* Allocate a struct elt_list and fill in its two elements with the
217 static inline struct elt_list
*
218 new_elt_list (struct elt_list
*next
, cselib_val
*elt
)
221 el
= (struct elt_list
*) pool_alloc (elt_list_pool
);
227 /* Allocate a struct elt_loc_list with LOC and prepend it to VAL's loc
231 new_elt_loc_list (cselib_val
*val
, rtx loc
)
233 struct elt_loc_list
*el
, *next
= val
->locs
;
235 gcc_checking_assert (!next
|| !next
->setting_insn
236 || !DEBUG_INSN_P (next
->setting_insn
)
237 || cselib_current_insn
== next
->setting_insn
);
239 /* If we're creating the first loc in a debug insn context, we've
240 just created a debug value. Count it. */
241 if (!next
&& cselib_current_insn
&& DEBUG_INSN_P (cselib_current_insn
))
244 val
= canonical_cselib_val (val
);
247 if (GET_CODE (loc
) == VALUE
)
249 loc
= canonical_cselib_val (CSELIB_VAL_PTR (loc
))->val_rtx
;
251 gcc_checking_assert (PRESERVED_VALUE_P (loc
)
252 == PRESERVED_VALUE_P (val
->val_rtx
));
254 if (val
->val_rtx
== loc
)
256 else if (val
->uid
> CSELIB_VAL_PTR (loc
)->uid
)
258 /* Reverse the insertion. */
259 new_elt_loc_list (CSELIB_VAL_PTR (loc
), val
->val_rtx
);
263 gcc_checking_assert (val
->uid
< CSELIB_VAL_PTR (loc
)->uid
);
265 if (CSELIB_VAL_PTR (loc
)->locs
)
267 /* Bring all locs from LOC to VAL. */
268 for (el
= CSELIB_VAL_PTR (loc
)->locs
; el
->next
; el
= el
->next
)
270 /* Adjust values that have LOC as canonical so that VAL
271 becomes their canonical. */
272 if (el
->loc
&& GET_CODE (el
->loc
) == VALUE
)
274 gcc_checking_assert (CSELIB_VAL_PTR (el
->loc
)->locs
->loc
276 CSELIB_VAL_PTR (el
->loc
)->locs
->loc
= val
->val_rtx
;
279 el
->next
= val
->locs
;
280 next
= val
->locs
= CSELIB_VAL_PTR (loc
)->locs
;
283 if (CSELIB_VAL_PTR (loc
)->addr_list
)
285 /* Bring in addr_list into canonical node. */
286 struct elt_list
*last
= CSELIB_VAL_PTR (loc
)->addr_list
;
289 last
->next
= val
->addr_list
;
290 val
->addr_list
= CSELIB_VAL_PTR (loc
)->addr_list
;
291 CSELIB_VAL_PTR (loc
)->addr_list
= NULL
;
294 if (CSELIB_VAL_PTR (loc
)->next_containing_mem
!= NULL
295 && val
->next_containing_mem
== NULL
)
297 /* Add VAL to the containing_mem list after LOC. LOC will
298 be removed when we notice it doesn't contain any
300 val
->next_containing_mem
= CSELIB_VAL_PTR (loc
)->next_containing_mem
;
301 CSELIB_VAL_PTR (loc
)->next_containing_mem
= val
;
304 /* Chain LOC back to VAL. */
305 el
= (struct elt_loc_list
*) pool_alloc (elt_loc_list_pool
);
306 el
->loc
= val
->val_rtx
;
307 el
->setting_insn
= cselib_current_insn
;
309 CSELIB_VAL_PTR (loc
)->locs
= el
;
312 el
= (struct elt_loc_list
*) pool_alloc (elt_loc_list_pool
);
314 el
->setting_insn
= cselib_current_insn
;
319 /* Promote loc L to a nondebug cselib_current_insn if L is marked as
320 originating from a debug insn, maintaining the debug values
324 promote_debug_loc (struct elt_loc_list
*l
)
326 if (l
->setting_insn
&& DEBUG_INSN_P (l
->setting_insn
)
327 && (!cselib_current_insn
|| !DEBUG_INSN_P (cselib_current_insn
)))
330 l
->setting_insn
= cselib_current_insn
;
331 if (cselib_preserve_constants
&& l
->next
)
333 gcc_assert (l
->next
->setting_insn
334 && DEBUG_INSN_P (l
->next
->setting_insn
)
336 l
->next
->setting_insn
= cselib_current_insn
;
339 gcc_assert (!l
->next
);
343 /* The elt_list at *PL is no longer needed. Unchain it and free its
347 unchain_one_elt_list (struct elt_list
**pl
)
349 struct elt_list
*l
= *pl
;
352 pool_free (elt_list_pool
, l
);
355 /* Likewise for elt_loc_lists. */
358 unchain_one_elt_loc_list (struct elt_loc_list
**pl
)
360 struct elt_loc_list
*l
= *pl
;
363 pool_free (elt_loc_list_pool
, l
);
366 /* Likewise for cselib_vals. This also frees the addr_list associated with
370 unchain_one_value (cselib_val
*v
)
373 unchain_one_elt_list (&v
->addr_list
);
375 pool_free (cselib_val_pool
, v
);
378 /* Remove all entries from the hash table. Also used during
382 cselib_clear_table (void)
384 cselib_reset_table (1);
387 /* Return TRUE if V is a constant, a function invariant or a VALUE
388 equivalence; FALSE otherwise. */
391 invariant_or_equiv_p (cselib_val
*v
)
393 struct elt_loc_list
*l
;
395 if (v
== cfa_base_preserved_val
)
398 /* Keep VALUE equivalences around. */
399 for (l
= v
->locs
; l
; l
= l
->next
)
400 if (GET_CODE (l
->loc
) == VALUE
)
404 && v
->locs
->next
== NULL
)
406 if (CONSTANT_P (v
->locs
->loc
)
407 && (GET_CODE (v
->locs
->loc
) != CONST
408 || !references_value_p (v
->locs
->loc
, 0)))
410 /* Although a debug expr may be bound to different expressions,
411 we can preserve it as if it was constant, to get unification
412 and proper merging within var-tracking. */
413 if (GET_CODE (v
->locs
->loc
) == DEBUG_EXPR
414 || GET_CODE (v
->locs
->loc
) == DEBUG_IMPLICIT_PTR
415 || GET_CODE (v
->locs
->loc
) == ENTRY_VALUE
416 || GET_CODE (v
->locs
->loc
) == DEBUG_PARAMETER_REF
)
419 /* (plus (value V) (const_int C)) is invariant iff V is invariant. */
420 if (GET_CODE (v
->locs
->loc
) == PLUS
421 && CONST_INT_P (XEXP (v
->locs
->loc
, 1))
422 && GET_CODE (XEXP (v
->locs
->loc
, 0)) == VALUE
423 && invariant_or_equiv_p (CSELIB_VAL_PTR (XEXP (v
->locs
->loc
, 0))))
430 /* Remove from hash table all VALUEs except constants, function
431 invariants and VALUE equivalences. */
434 preserve_constants_and_equivs (void **x
, void *info ATTRIBUTE_UNUSED
)
436 cselib_val
*v
= (cselib_val
*)*x
;
438 if (!invariant_or_equiv_p (v
))
439 htab_clear_slot (cselib_hash_table
, x
);
443 /* Remove all entries from the hash table, arranging for the next
444 value to be numbered NUM. */
447 cselib_reset_table (unsigned int num
)
453 if (cfa_base_preserved_val
)
455 unsigned int regno
= cfa_base_preserved_regno
;
456 unsigned int new_used_regs
= 0;
457 for (i
= 0; i
< n_used_regs
; i
++)
458 if (used_regs
[i
] == regno
)
464 REG_VALUES (used_regs
[i
]) = 0;
465 gcc_assert (new_used_regs
== 1);
466 n_used_regs
= new_used_regs
;
467 used_regs
[0] = regno
;
469 = hard_regno_nregs
[regno
][GET_MODE (cfa_base_preserved_val
->locs
->loc
)];
473 for (i
= 0; i
< n_used_regs
; i
++)
474 REG_VALUES (used_regs
[i
]) = 0;
478 if (cselib_preserve_constants
)
479 htab_traverse (cselib_hash_table
, preserve_constants_and_equivs
, NULL
);
482 htab_empty (cselib_hash_table
);
483 gcc_checking_assert (!cselib_any_perm_equivs
);
486 n_useless_values
= 0;
487 n_useless_debug_values
= 0;
492 first_containing_mem
= &dummy_val
;
495 /* Return the number of the next value that will be generated. */
498 cselib_get_next_uid (void)
503 /* See the documentation of cselib_find_slot below. */
504 static enum machine_mode find_slot_memmode
;
506 /* Search for X, whose hashcode is HASH, in CSELIB_HASH_TABLE,
507 INSERTing if requested. When X is part of the address of a MEM,
508 MEMMODE should specify the mode of the MEM. While searching the
509 table, MEMMODE is held in FIND_SLOT_MEMMODE, so that autoinc RTXs
510 in X can be resolved. */
513 cselib_find_slot (rtx x
, hashval_t hash
, enum insert_option insert
,
514 enum machine_mode memmode
)
517 find_slot_memmode
= memmode
;
518 slot
= htab_find_slot_with_hash (cselib_hash_table
, x
, hash
, insert
);
519 find_slot_memmode
= VOIDmode
;
523 /* The equality test for our hash table. The first argument ENTRY is a table
524 element (i.e. a cselib_val), while the second arg X is an rtx. We know
525 that all callers of htab_find_slot_with_hash will wrap CONST_INTs into a
526 CONST of an appropriate mode. */
529 entry_and_rtx_equal_p (const void *entry
, const void *x_arg
)
531 struct elt_loc_list
*l
;
532 const cselib_val
*const v
= (const cselib_val
*) entry
;
533 rtx x
= CONST_CAST_RTX ((const_rtx
)x_arg
);
534 enum machine_mode mode
= GET_MODE (x
);
536 gcc_assert (!CONST_INT_P (x
) && GET_CODE (x
) != CONST_FIXED
537 && (mode
!= VOIDmode
|| GET_CODE (x
) != CONST_DOUBLE
));
539 if (mode
!= GET_MODE (v
->val_rtx
))
542 /* Unwrap X if necessary. */
543 if (GET_CODE (x
) == CONST
544 && (CONST_INT_P (XEXP (x
, 0))
545 || GET_CODE (XEXP (x
, 0)) == CONST_FIXED
546 || GET_CODE (XEXP (x
, 0)) == CONST_DOUBLE
))
549 /* We don't guarantee that distinct rtx's have different hash values,
550 so we need to do a comparison. */
551 for (l
= v
->locs
; l
; l
= l
->next
)
552 if (rtx_equal_for_cselib_1 (l
->loc
, x
, find_slot_memmode
))
554 promote_debug_loc (l
);
561 /* The hash function for our hash table. The value is always computed with
562 cselib_hash_rtx when adding an element; this function just extracts the
563 hash value from a cselib_val structure. */
566 get_value_hash (const void *entry
)
568 const cselib_val
*const v
= (const cselib_val
*) entry
;
572 /* Return true if X contains a VALUE rtx. If ONLY_USELESS is set, we
573 only return true for values which point to a cselib_val whose value
574 element has been set to zero, which implies the cselib_val will be
578 references_value_p (const_rtx x
, int only_useless
)
580 const enum rtx_code code
= GET_CODE (x
);
581 const char *fmt
= GET_RTX_FORMAT (code
);
584 if (GET_CODE (x
) == VALUE
585 && (! only_useless
||
586 (CSELIB_VAL_PTR (x
)->locs
== 0 && !PRESERVED_VALUE_P (x
))))
589 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
591 if (fmt
[i
] == 'e' && references_value_p (XEXP (x
, i
), only_useless
))
593 else if (fmt
[i
] == 'E')
594 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
595 if (references_value_p (XVECEXP (x
, i
, j
), only_useless
))
602 /* For all locations found in X, delete locations that reference useless
603 values (i.e. values without any location). Called through
607 discard_useless_locs (void **x
, void *info ATTRIBUTE_UNUSED
)
609 cselib_val
*v
= (cselib_val
*)*x
;
610 struct elt_loc_list
**p
= &v
->locs
;
611 bool had_locs
= v
->locs
!= NULL
;
612 rtx setting_insn
= v
->locs
? v
->locs
->setting_insn
: NULL
;
616 if (references_value_p ((*p
)->loc
, 1))
617 unchain_one_elt_loc_list (p
);
622 if (had_locs
&& v
->locs
== 0 && !PRESERVED_VALUE_P (v
->val_rtx
))
624 if (setting_insn
&& DEBUG_INSN_P (setting_insn
))
625 n_useless_debug_values
++;
628 values_became_useless
= 1;
633 /* If X is a value with no locations, remove it from the hashtable. */
636 discard_useless_values (void **x
, void *info ATTRIBUTE_UNUSED
)
638 cselib_val
*v
= (cselib_val
*)*x
;
640 if (v
->locs
== 0 && !PRESERVED_VALUE_P (v
->val_rtx
))
642 if (cselib_discard_hook
)
643 cselib_discard_hook (v
);
645 CSELIB_VAL_PTR (v
->val_rtx
) = NULL
;
646 htab_clear_slot (cselib_hash_table
, x
);
647 unchain_one_value (v
);
654 /* Clean out useless values (i.e. those which no longer have locations
655 associated with them) from the hash table. */
658 remove_useless_values (void)
662 /* First pass: eliminate locations that reference the value. That in
663 turn can make more values useless. */
666 values_became_useless
= 0;
667 htab_traverse (cselib_hash_table
, discard_useless_locs
, 0);
669 while (values_became_useless
);
671 /* Second pass: actually remove the values. */
673 p
= &first_containing_mem
;
674 for (v
= *p
; v
!= &dummy_val
; v
= v
->next_containing_mem
)
675 if (v
->locs
&& v
== canonical_cselib_val (v
))
678 p
= &(*p
)->next_containing_mem
;
682 n_useless_values
+= n_useless_debug_values
;
683 n_debug_values
-= n_useless_debug_values
;
684 n_useless_debug_values
= 0;
686 htab_traverse (cselib_hash_table
, discard_useless_values
, 0);
688 gcc_assert (!n_useless_values
);
691 /* Arrange for a value to not be removed from the hash table even if
692 it becomes useless. */
695 cselib_preserve_value (cselib_val
*v
)
697 PRESERVED_VALUE_P (v
->val_rtx
) = 1;
700 /* Test whether a value is preserved. */
703 cselib_preserved_value_p (cselib_val
*v
)
705 return PRESERVED_VALUE_P (v
->val_rtx
);
708 /* Arrange for a REG value to be assumed constant through the whole function,
709 never invalidated and preserved across cselib_reset_table calls. */
712 cselib_preserve_cfa_base_value (cselib_val
*v
, unsigned int regno
)
714 if (cselib_preserve_constants
716 && REG_P (v
->locs
->loc
))
718 cfa_base_preserved_val
= v
;
719 cfa_base_preserved_regno
= regno
;
723 /* Clean all non-constant expressions in the hash table, but retain
727 cselib_preserve_only_values (void)
731 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; i
++)
732 cselib_invalidate_regno (i
, reg_raw_mode
[i
]);
734 cselib_invalidate_mem (callmem
);
736 remove_useless_values ();
738 gcc_assert (first_containing_mem
== &dummy_val
);
741 /* Return the mode in which a register was last set. If X is not a
742 register, return its mode. If the mode in which the register was
743 set is not known, or the value was already clobbered, return
747 cselib_reg_set_mode (const_rtx x
)
752 if (REG_VALUES (REGNO (x
)) == NULL
753 || REG_VALUES (REGNO (x
))->elt
== NULL
)
756 return GET_MODE (REG_VALUES (REGNO (x
))->elt
->val_rtx
);
759 /* Return nonzero if we can prove that X and Y contain the same value, taking
760 our gathered information into account. */
763 rtx_equal_for_cselib_p (rtx x
, rtx y
)
765 return rtx_equal_for_cselib_1 (x
, y
, VOIDmode
);
768 /* If x is a PLUS or an autoinc operation, expand the operation,
769 storing the offset, if any, in *OFF. */
772 autoinc_split (rtx x
, rtx
*off
, enum machine_mode memmode
)
774 switch (GET_CODE (x
))
781 if (memmode
== VOIDmode
)
784 *off
= GEN_INT (-GET_MODE_SIZE (memmode
));
789 if (memmode
== VOIDmode
)
792 *off
= GEN_INT (GET_MODE_SIZE (memmode
));
808 /* Return nonzero if we can prove that X and Y contain the same value,
809 taking our gathered information into account. MEMMODE holds the
810 mode of the enclosing MEM, if any, as required to deal with autoinc
811 addressing modes. If X and Y are not (known to be) part of
812 addresses, MEMMODE should be VOIDmode. */
815 rtx_equal_for_cselib_1 (rtx x
, rtx y
, enum machine_mode memmode
)
821 if (REG_P (x
) || MEM_P (x
))
823 cselib_val
*e
= cselib_lookup (x
, GET_MODE (x
), 0, memmode
);
829 if (REG_P (y
) || MEM_P (y
))
831 cselib_val
*e
= cselib_lookup (y
, GET_MODE (y
), 0, memmode
);
840 if (GET_CODE (x
) == VALUE
)
842 cselib_val
*e
= canonical_cselib_val (CSELIB_VAL_PTR (x
));
843 struct elt_loc_list
*l
;
845 if (GET_CODE (y
) == VALUE
)
846 return e
== canonical_cselib_val (CSELIB_VAL_PTR (y
));
848 for (l
= e
->locs
; l
; l
= l
->next
)
852 /* Avoid infinite recursion. We know we have the canonical
853 value, so we can just skip any values in the equivalence
855 if (REG_P (t
) || MEM_P (t
) || GET_CODE (t
) == VALUE
)
857 else if (rtx_equal_for_cselib_1 (t
, y
, memmode
))
863 else if (GET_CODE (y
) == VALUE
)
865 cselib_val
*e
= canonical_cselib_val (CSELIB_VAL_PTR (y
));
866 struct elt_loc_list
*l
;
868 for (l
= e
->locs
; l
; l
= l
->next
)
872 if (REG_P (t
) || MEM_P (t
) || GET_CODE (t
) == VALUE
)
874 else if (rtx_equal_for_cselib_1 (x
, t
, memmode
))
881 if (GET_MODE (x
) != GET_MODE (y
))
884 if (GET_CODE (x
) != GET_CODE (y
))
886 rtx xorig
= x
, yorig
= y
;
887 rtx xoff
= NULL
, yoff
= NULL
;
889 x
= autoinc_split (x
, &xoff
, memmode
);
890 y
= autoinc_split (y
, &yoff
, memmode
);
895 if (xoff
&& !rtx_equal_for_cselib_1 (xoff
, yoff
, memmode
))
898 /* Don't recurse if nothing changed. */
899 if (x
!= xorig
|| y
!= yorig
)
900 return rtx_equal_for_cselib_1 (x
, y
, memmode
);
905 /* These won't be handled correctly by the code below. */
906 switch (GET_CODE (x
))
913 case DEBUG_IMPLICIT_PTR
:
914 return DEBUG_IMPLICIT_PTR_DECL (x
)
915 == DEBUG_IMPLICIT_PTR_DECL (y
);
917 case DEBUG_PARAMETER_REF
:
918 return DEBUG_PARAMETER_REF_DECL (x
)
919 == DEBUG_PARAMETER_REF_DECL (y
);
922 /* ENTRY_VALUEs are function invariant, it is thus undesirable to
923 use rtx_equal_for_cselib_1 to compare the operands. */
924 return rtx_equal_p (ENTRY_VALUE_EXP (x
), ENTRY_VALUE_EXP (y
));
927 return XEXP (x
, 0) == XEXP (y
, 0);
930 /* We have to compare any autoinc operations in the addresses
931 using this MEM's mode. */
932 return rtx_equal_for_cselib_1 (XEXP (x
, 0), XEXP (y
, 0), GET_MODE (x
));
939 fmt
= GET_RTX_FORMAT (code
);
941 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
948 if (XWINT (x
, i
) != XWINT (y
, i
))
954 if (XINT (x
, i
) != XINT (y
, i
))
960 /* Two vectors must have the same length. */
961 if (XVECLEN (x
, i
) != XVECLEN (y
, i
))
964 /* And the corresponding elements must match. */
965 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
966 if (! rtx_equal_for_cselib_1 (XVECEXP (x
, i
, j
),
967 XVECEXP (y
, i
, j
), memmode
))
973 && targetm
.commutative_p (x
, UNKNOWN
)
974 && rtx_equal_for_cselib_1 (XEXP (x
, 1), XEXP (y
, 0), memmode
)
975 && rtx_equal_for_cselib_1 (XEXP (x
, 0), XEXP (y
, 1), memmode
))
977 if (! rtx_equal_for_cselib_1 (XEXP (x
, i
), XEXP (y
, i
), memmode
))
983 if (strcmp (XSTR (x
, i
), XSTR (y
, i
)))
988 /* These are just backpointers, so they don't matter. */
995 /* It is believed that rtx's at this level will never
996 contain anything but integers and other rtx's,
997 except for within LABEL_REFs and SYMBOL_REFs. */
1005 /* We need to pass down the mode of constants through the hash table
1006 functions. For that purpose, wrap them in a CONST of the appropriate
1009 wrap_constant (enum machine_mode mode
, rtx x
)
1011 if (!CONST_INT_P (x
) && GET_CODE (x
) != CONST_FIXED
1012 && (GET_CODE (x
) != CONST_DOUBLE
|| GET_MODE (x
) != VOIDmode
))
1014 gcc_assert (mode
!= VOIDmode
);
1015 return gen_rtx_CONST (mode
, x
);
1018 /* Hash an rtx. Return 0 if we couldn't hash the rtx.
1019 For registers and memory locations, we look up their cselib_val structure
1020 and return its VALUE element.
1021 Possible reasons for return 0 are: the object is volatile, or we couldn't
1022 find a register or memory location in the table and CREATE is zero. If
1023 CREATE is nonzero, table elts are created for regs and mem.
1024 N.B. this hash function returns the same hash value for RTXes that
1025 differ only in the order of operands, thus it is suitable for comparisons
1026 that take commutativity into account.
1027 If we wanted to also support associative rules, we'd have to use a different
1028 strategy to avoid returning spurious 0, e.g. return ~(~0U >> 1) .
1029 MEMMODE indicates the mode of an enclosing MEM, and it's only
1030 used to compute autoinc values.
1031 We used to have a MODE argument for hashing for CONST_INTs, but that
1032 didn't make sense, since it caused spurious hash differences between
1033 (set (reg:SI 1) (const_int))
1034 (plus:SI (reg:SI 2) (reg:SI 1))
1036 (plus:SI (reg:SI 2) (const_int))
1037 If the mode is important in any context, it must be checked specifically
1038 in a comparison anyway, since relying on hash differences is unsafe. */
1041 cselib_hash_rtx (rtx x
, int create
, enum machine_mode memmode
)
1047 unsigned int hash
= 0;
1049 code
= GET_CODE (x
);
1050 hash
+= (unsigned) code
+ (unsigned) GET_MODE (x
);
1055 e
= CSELIB_VAL_PTR (x
);
1060 e
= cselib_lookup (x
, GET_MODE (x
), create
, memmode
);
1067 hash
+= ((unsigned) DEBUG_EXPR
<< 7)
1068 + DEBUG_TEMP_UID (DEBUG_EXPR_TREE_DECL (x
));
1069 return hash
? hash
: (unsigned int) DEBUG_EXPR
;
1071 case DEBUG_IMPLICIT_PTR
:
1072 hash
+= ((unsigned) DEBUG_IMPLICIT_PTR
<< 7)
1073 + DECL_UID (DEBUG_IMPLICIT_PTR_DECL (x
));
1074 return hash
? hash
: (unsigned int) DEBUG_IMPLICIT_PTR
;
1076 case DEBUG_PARAMETER_REF
:
1077 hash
+= ((unsigned) DEBUG_PARAMETER_REF
<< 7)
1078 + DECL_UID (DEBUG_PARAMETER_REF_DECL (x
));
1079 return hash
? hash
: (unsigned int) DEBUG_PARAMETER_REF
;
1082 /* ENTRY_VALUEs are function invariant, thus try to avoid
1083 recursing on argument if ENTRY_VALUE is one of the
1084 forms emitted by expand_debug_expr, otherwise
1085 ENTRY_VALUE hash would depend on the current value
1086 in some register or memory. */
1087 if (REG_P (ENTRY_VALUE_EXP (x
)))
1088 hash
+= (unsigned int) REG
1089 + (unsigned int) GET_MODE (ENTRY_VALUE_EXP (x
))
1090 + (unsigned int) REGNO (ENTRY_VALUE_EXP (x
));
1091 else if (MEM_P (ENTRY_VALUE_EXP (x
))
1092 && REG_P (XEXP (ENTRY_VALUE_EXP (x
), 0)))
1093 hash
+= (unsigned int) MEM
1094 + (unsigned int) GET_MODE (XEXP (ENTRY_VALUE_EXP (x
), 0))
1095 + (unsigned int) REGNO (XEXP (ENTRY_VALUE_EXP (x
), 0));
1097 hash
+= cselib_hash_rtx (ENTRY_VALUE_EXP (x
), create
, memmode
);
1098 return hash
? hash
: (unsigned int) ENTRY_VALUE
;
1101 hash
+= ((unsigned) CONST_INT
<< 7) + INTVAL (x
);
1102 return hash
? hash
: (unsigned int) CONST_INT
;
1105 /* This is like the general case, except that it only counts
1106 the integers representing the constant. */
1107 hash
+= (unsigned) code
+ (unsigned) GET_MODE (x
);
1108 if (GET_MODE (x
) != VOIDmode
)
1109 hash
+= real_hash (CONST_DOUBLE_REAL_VALUE (x
));
1111 hash
+= ((unsigned) CONST_DOUBLE_LOW (x
)
1112 + (unsigned) CONST_DOUBLE_HIGH (x
));
1113 return hash
? hash
: (unsigned int) CONST_DOUBLE
;
1116 hash
+= (unsigned int) code
+ (unsigned int) GET_MODE (x
);
1117 hash
+= fixed_hash (CONST_FIXED_VALUE (x
));
1118 return hash
? hash
: (unsigned int) CONST_FIXED
;
1125 units
= CONST_VECTOR_NUNITS (x
);
1127 for (i
= 0; i
< units
; ++i
)
1129 elt
= CONST_VECTOR_ELT (x
, i
);
1130 hash
+= cselib_hash_rtx (elt
, 0, memmode
);
1136 /* Assume there is only one rtx object for any given label. */
1138 /* We don't hash on the address of the CODE_LABEL to avoid bootstrap
1139 differences and differences between each stage's debugging dumps. */
1140 hash
+= (((unsigned int) LABEL_REF
<< 7)
1141 + CODE_LABEL_NUMBER (XEXP (x
, 0)));
1142 return hash
? hash
: (unsigned int) LABEL_REF
;
1146 /* Don't hash on the symbol's address to avoid bootstrap differences.
1147 Different hash values may cause expressions to be recorded in
1148 different orders and thus different registers to be used in the
1149 final assembler. This also avoids differences in the dump files
1150 between various stages. */
1152 const unsigned char *p
= (const unsigned char *) XSTR (x
, 0);
1155 h
+= (h
<< 7) + *p
++; /* ??? revisit */
1157 hash
+= ((unsigned int) SYMBOL_REF
<< 7) + h
;
1158 return hash
? hash
: (unsigned int) SYMBOL_REF
;
1163 /* We can't compute these without knowing the MEM mode. */
1164 gcc_assert (memmode
!= VOIDmode
);
1165 i
= GET_MODE_SIZE (memmode
);
1166 if (code
== PRE_DEC
)
1168 /* Adjust the hash so that (mem:MEMMODE (pre_* (reg))) hashes
1169 like (mem:MEMMODE (plus (reg) (const_int I))). */
1170 hash
+= (unsigned) PLUS
- (unsigned)code
1171 + cselib_hash_rtx (XEXP (x
, 0), create
, memmode
)
1172 + cselib_hash_rtx (GEN_INT (i
), create
, memmode
);
1173 return hash
? hash
: 1 + (unsigned) PLUS
;
1176 gcc_assert (memmode
!= VOIDmode
);
1177 return cselib_hash_rtx (XEXP (x
, 1), create
, memmode
);
1182 gcc_assert (memmode
!= VOIDmode
);
1183 return cselib_hash_rtx (XEXP (x
, 0), create
, memmode
);
1188 case UNSPEC_VOLATILE
:
1192 if (MEM_VOLATILE_P (x
))
1201 i
= GET_RTX_LENGTH (code
) - 1;
1202 fmt
= GET_RTX_FORMAT (code
);
1209 rtx tem
= XEXP (x
, i
);
1210 unsigned int tem_hash
= cselib_hash_rtx (tem
, create
, memmode
);
1219 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
1221 unsigned int tem_hash
1222 = cselib_hash_rtx (XVECEXP (x
, i
, j
), create
, memmode
);
1233 const unsigned char *p
= (const unsigned char *) XSTR (x
, i
);
1242 hash
+= XINT (x
, i
);
1255 return hash
? hash
: 1 + (unsigned int) GET_CODE (x
);
1258 /* Create a new value structure for VALUE and initialize it. The mode of the
1261 static inline cselib_val
*
1262 new_cselib_val (unsigned int hash
, enum machine_mode mode
, rtx x
)
1264 cselib_val
*e
= (cselib_val
*) pool_alloc (cselib_val_pool
);
1267 gcc_assert (next_uid
);
1270 e
->uid
= next_uid
++;
1271 /* We use an alloc pool to allocate this RTL construct because it
1272 accounts for about 8% of the overall memory usage. We know
1273 precisely when we can have VALUE RTXen (when cselib is active)
1274 so we don't need to put them in garbage collected memory.
1275 ??? Why should a VALUE be an RTX in the first place? */
1276 e
->val_rtx
= (rtx
) pool_alloc (value_pool
);
1277 memset (e
->val_rtx
, 0, RTX_HDR_SIZE
);
1278 PUT_CODE (e
->val_rtx
, VALUE
);
1279 PUT_MODE (e
->val_rtx
, mode
);
1280 CSELIB_VAL_PTR (e
->val_rtx
) = e
;
1283 e
->next_containing_mem
= 0;
1285 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1287 fprintf (dump_file
, "cselib value %u:%u ", e
->uid
, hash
);
1288 if (flag_dump_noaddr
|| flag_dump_unnumbered
)
1289 fputs ("# ", dump_file
);
1291 fprintf (dump_file
, "%p ", (void*)e
);
1292 print_rtl_single (dump_file
, x
);
1293 fputc ('\n', dump_file
);
1299 /* ADDR_ELT is a value that is used as address. MEM_ELT is the value that
1300 contains the data at this address. X is a MEM that represents the
1301 value. Update the two value structures to represent this situation. */
1304 add_mem_for_addr (cselib_val
*addr_elt
, cselib_val
*mem_elt
, rtx x
)
1306 struct elt_loc_list
*l
;
1308 addr_elt
= canonical_cselib_val (addr_elt
);
1309 mem_elt
= canonical_cselib_val (mem_elt
);
1311 /* Avoid duplicates. */
1312 for (l
= mem_elt
->locs
; l
; l
= l
->next
)
1314 && CSELIB_VAL_PTR (XEXP (l
->loc
, 0)) == addr_elt
)
1316 promote_debug_loc (l
);
1320 addr_elt
->addr_list
= new_elt_list (addr_elt
->addr_list
, mem_elt
);
1321 new_elt_loc_list (mem_elt
,
1322 replace_equiv_address_nv (x
, addr_elt
->val_rtx
));
1323 if (mem_elt
->next_containing_mem
== NULL
)
1325 mem_elt
->next_containing_mem
= first_containing_mem
;
1326 first_containing_mem
= mem_elt
;
1330 /* Subroutine of cselib_lookup. Return a value for X, which is a MEM rtx.
1331 If CREATE, make a new one if we haven't seen it before. */
1334 cselib_lookup_mem (rtx x
, int create
)
1336 enum machine_mode mode
= GET_MODE (x
);
1337 enum machine_mode addr_mode
;
1340 cselib_val
*mem_elt
;
1343 if (MEM_VOLATILE_P (x
) || mode
== BLKmode
1344 || !cselib_record_memory
1345 || (FLOAT_MODE_P (mode
) && flag_float_store
))
1348 addr_mode
= GET_MODE (XEXP (x
, 0));
1349 if (addr_mode
== VOIDmode
)
1352 /* Look up the value for the address. */
1353 addr
= cselib_lookup (XEXP (x
, 0), addr_mode
, create
, mode
);
1357 addr
= canonical_cselib_val (addr
);
1358 /* Find a value that describes a value of our mode at that address. */
1359 for (l
= addr
->addr_list
; l
; l
= l
->next
)
1360 if (GET_MODE (l
->elt
->val_rtx
) == mode
)
1362 promote_debug_loc (l
->elt
->locs
);
1369 mem_elt
= new_cselib_val (next_uid
, mode
, x
);
1370 add_mem_for_addr (addr
, mem_elt
, x
);
1371 slot
= cselib_find_slot (wrap_constant (mode
, x
), mem_elt
->hash
,
1377 /* Search thru the possible substitutions in P. We prefer a non reg
1378 substitution because this allows us to expand the tree further. If
1379 we find, just a reg, take the lowest regno. There may be several
1380 non-reg results, we just take the first one because they will all
1381 expand to the same place. */
1384 expand_loc (struct elt_loc_list
*p
, struct expand_value_data
*evd
,
1387 rtx reg_result
= NULL
;
1388 unsigned int regno
= UINT_MAX
;
1389 struct elt_loc_list
*p_in
= p
;
1391 for (; p
; p
= p
->next
)
1393 /* Return these right away to avoid returning stack pointer based
1394 expressions for frame pointer and vice versa, which is something
1395 that would confuse DSE. See the comment in cselib_expand_value_rtx_1
1396 for more details. */
1398 && (REGNO (p
->loc
) == STACK_POINTER_REGNUM
1399 || REGNO (p
->loc
) == FRAME_POINTER_REGNUM
1400 || REGNO (p
->loc
) == HARD_FRAME_POINTER_REGNUM
1401 || REGNO (p
->loc
) == cfa_base_preserved_regno
))
1403 /* Avoid infinite recursion trying to expand a reg into a
1405 if ((REG_P (p
->loc
))
1406 && (REGNO (p
->loc
) < regno
)
1407 && !bitmap_bit_p (evd
->regs_active
, REGNO (p
->loc
)))
1409 reg_result
= p
->loc
;
1410 regno
= REGNO (p
->loc
);
1412 /* Avoid infinite recursion and do not try to expand the
1414 else if (GET_CODE (p
->loc
) == VALUE
1415 && CSELIB_VAL_PTR (p
->loc
)->locs
== p_in
)
1417 else if (!REG_P (p
->loc
))
1420 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1422 print_inline_rtx (dump_file
, p
->loc
, 0);
1423 fprintf (dump_file
, "\n");
1425 if (GET_CODE (p
->loc
) == LO_SUM
1426 && GET_CODE (XEXP (p
->loc
, 1)) == SYMBOL_REF
1428 && (note
= find_reg_note (p
->setting_insn
, REG_EQUAL
, NULL_RTX
))
1429 && XEXP (note
, 0) == XEXP (p
->loc
, 1))
1430 return XEXP (p
->loc
, 1);
1431 result
= cselib_expand_value_rtx_1 (p
->loc
, evd
, max_depth
- 1);
1438 if (regno
!= UINT_MAX
)
1441 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1442 fprintf (dump_file
, "r%d\n", regno
);
1444 result
= cselib_expand_value_rtx_1 (reg_result
, evd
, max_depth
- 1);
1449 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1453 print_inline_rtx (dump_file
, reg_result
, 0);
1454 fprintf (dump_file
, "\n");
1457 fprintf (dump_file
, "NULL\n");
1463 /* Forward substitute and expand an expression out to its roots.
1464 This is the opposite of common subexpression. Because local value
1465 numbering is such a weak optimization, the expanded expression is
1466 pretty much unique (not from a pointer equals point of view but
1467 from a tree shape point of view.
1469 This function returns NULL if the expansion fails. The expansion
1470 will fail if there is no value number for one of the operands or if
1471 one of the operands has been overwritten between the current insn
1472 and the beginning of the basic block. For instance x has no
1478 REGS_ACTIVE is a scratch bitmap that should be clear when passing in.
1479 It is clear on return. */
1482 cselib_expand_value_rtx (rtx orig
, bitmap regs_active
, int max_depth
)
1484 struct expand_value_data evd
;
1486 evd
.regs_active
= regs_active
;
1487 evd
.callback
= NULL
;
1488 evd
.callback_arg
= NULL
;
1491 return cselib_expand_value_rtx_1 (orig
, &evd
, max_depth
);
1494 /* Same as cselib_expand_value_rtx, but using a callback to try to
1495 resolve some expressions. The CB function should return ORIG if it
1496 can't or does not want to deal with a certain RTX. Any other
1497 return value, including NULL, will be used as the expansion for
1498 VALUE, without any further changes. */
1501 cselib_expand_value_rtx_cb (rtx orig
, bitmap regs_active
, int max_depth
,
1502 cselib_expand_callback cb
, void *data
)
1504 struct expand_value_data evd
;
1506 evd
.regs_active
= regs_active
;
1508 evd
.callback_arg
= data
;
1511 return cselib_expand_value_rtx_1 (orig
, &evd
, max_depth
);
1514 /* Similar to cselib_expand_value_rtx_cb, but no rtxs are actually copied
1515 or simplified. Useful to find out whether cselib_expand_value_rtx_cb
1516 would return NULL or non-NULL, without allocating new rtx. */
1519 cselib_dummy_expand_value_rtx_cb (rtx orig
, bitmap regs_active
, int max_depth
,
1520 cselib_expand_callback cb
, void *data
)
1522 struct expand_value_data evd
;
1524 evd
.regs_active
= regs_active
;
1526 evd
.callback_arg
= data
;
1529 return cselib_expand_value_rtx_1 (orig
, &evd
, max_depth
) != NULL
;
1532 /* Internal implementation of cselib_expand_value_rtx and
1533 cselib_expand_value_rtx_cb. */
1536 cselib_expand_value_rtx_1 (rtx orig
, struct expand_value_data
*evd
,
1542 const char *format_ptr
;
1543 enum machine_mode mode
;
1545 code
= GET_CODE (orig
);
1547 /* For the context of dse, if we end up expand into a huge tree, we
1548 will not have a useful address, so we might as well just give up
1557 struct elt_list
*l
= REG_VALUES (REGNO (orig
));
1559 if (l
&& l
->elt
== NULL
)
1561 for (; l
; l
= l
->next
)
1562 if (GET_MODE (l
->elt
->val_rtx
) == GET_MODE (orig
))
1565 unsigned regno
= REGNO (orig
);
1567 /* The only thing that we are not willing to do (this
1568 is requirement of dse and if others potential uses
1569 need this function we should add a parm to control
1570 it) is that we will not substitute the
1571 STACK_POINTER_REGNUM, FRAME_POINTER or the
1574 These expansions confuses the code that notices that
1575 stores into the frame go dead at the end of the
1576 function and that the frame is not effected by calls
1577 to subroutines. If you allow the
1578 STACK_POINTER_REGNUM substitution, then dse will
1579 think that parameter pushing also goes dead which is
1580 wrong. If you allow the FRAME_POINTER or the
1581 HARD_FRAME_POINTER then you lose the opportunity to
1582 make the frame assumptions. */
1583 if (regno
== STACK_POINTER_REGNUM
1584 || regno
== FRAME_POINTER_REGNUM
1585 || regno
== HARD_FRAME_POINTER_REGNUM
1586 || regno
== cfa_base_preserved_regno
)
1589 bitmap_set_bit (evd
->regs_active
, regno
);
1591 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1592 fprintf (dump_file
, "expanding: r%d into: ", regno
);
1594 result
= expand_loc (l
->elt
->locs
, evd
, max_depth
);
1595 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
);
1865 gcc_assert (memmode
!= VOIDmode
);
1866 i
= GET_MODE_SIZE (memmode
);
1867 if (code
== PRE_DEC
)
1869 return cselib_subst_to_values (plus_constant (GET_MODE (x
),
1874 gcc_assert (memmode
!= VOIDmode
);
1875 return cselib_subst_to_values (XEXP (x
, 1), memmode
);
1880 gcc_assert (memmode
!= VOIDmode
);
1881 return cselib_subst_to_values (XEXP (x
, 0), memmode
);
1887 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
1891 rtx t
= cselib_subst_to_values (XEXP (x
, i
), memmode
);
1893 if (t
!= XEXP (x
, i
))
1896 copy
= shallow_copy_rtx (x
);
1900 else if (fmt
[i
] == 'E')
1904 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
1906 rtx t
= cselib_subst_to_values (XVECEXP (x
, i
, j
), memmode
);
1908 if (t
!= XVECEXP (x
, i
, j
))
1910 if (XVEC (x
, i
) == XVEC (copy
, i
))
1913 copy
= shallow_copy_rtx (x
);
1914 XVEC (copy
, i
) = shallow_copy_rtvec (XVEC (x
, i
));
1916 XVECEXP (copy
, i
, j
) = t
;
1925 /* Wrapper for cselib_subst_to_values, that indicates X is in INSN. */
1928 cselib_subst_to_values_from_insn (rtx x
, enum machine_mode memmode
, rtx insn
)
1931 gcc_assert (!cselib_current_insn
);
1932 cselib_current_insn
= insn
;
1933 ret
= cselib_subst_to_values (x
, memmode
);
1934 cselib_current_insn
= NULL
;
1938 /* Look up the rtl expression X in our tables and return the value it
1939 has. If CREATE is zero, we return NULL if we don't know the value.
1940 Otherwise, we create a new one if possible, using mode MODE if X
1941 doesn't have a mode (i.e. because it's a constant). When X is part
1942 of an address, MEMMODE should be the mode of the enclosing MEM if
1943 we're tracking autoinc expressions. */
1946 cselib_lookup_1 (rtx x
, enum machine_mode mode
,
1947 int create
, enum machine_mode memmode
)
1951 unsigned int hashval
;
1953 if (GET_MODE (x
) != VOIDmode
)
1954 mode
= GET_MODE (x
);
1956 if (GET_CODE (x
) == VALUE
)
1957 return CSELIB_VAL_PTR (x
);
1962 unsigned int i
= REGNO (x
);
1965 if (l
&& l
->elt
== NULL
)
1967 for (; l
; l
= l
->next
)
1968 if (mode
== GET_MODE (l
->elt
->val_rtx
))
1970 promote_debug_loc (l
->elt
->locs
);
1977 if (i
< FIRST_PSEUDO_REGISTER
)
1979 unsigned int n
= hard_regno_nregs
[i
][mode
];
1981 if (n
> max_value_regs
)
1985 e
= new_cselib_val (next_uid
, GET_MODE (x
), x
);
1986 new_elt_loc_list (e
, x
);
1987 if (REG_VALUES (i
) == 0)
1989 /* Maintain the invariant that the first entry of
1990 REG_VALUES, if present, must be the value used to set the
1991 register, or NULL. */
1992 used_regs
[n_used_regs
++] = i
;
1993 REG_VALUES (i
) = new_elt_list (REG_VALUES (i
), NULL
);
1995 else if (cselib_preserve_constants
1996 && GET_MODE_CLASS (mode
) == MODE_INT
)
1998 /* During var-tracking, try harder to find equivalences
1999 for SUBREGs. If a setter sets say a DImode register
2000 and user uses that register only in SImode, add a lowpart
2002 struct elt_list
*lwider
= NULL
;
2004 if (l
&& l
->elt
== NULL
)
2006 for (; l
; l
= l
->next
)
2007 if (GET_MODE_CLASS (GET_MODE (l
->elt
->val_rtx
)) == MODE_INT
2008 && GET_MODE_SIZE (GET_MODE (l
->elt
->val_rtx
))
2009 > GET_MODE_SIZE (mode
)
2011 || GET_MODE_SIZE (GET_MODE (l
->elt
->val_rtx
))
2012 < GET_MODE_SIZE (GET_MODE (lwider
->elt
->val_rtx
))))
2014 struct elt_loc_list
*el
;
2015 if (i
< FIRST_PSEUDO_REGISTER
2016 && hard_regno_nregs
[i
][GET_MODE (l
->elt
->val_rtx
)] != 1)
2018 for (el
= l
->elt
->locs
; el
; el
= el
->next
)
2019 if (!REG_P (el
->loc
))
2026 rtx sub
= lowpart_subreg (mode
, lwider
->elt
->val_rtx
,
2027 GET_MODE (lwider
->elt
->val_rtx
));
2029 new_elt_loc_list (e
, sub
);
2032 REG_VALUES (i
)->next
= new_elt_list (REG_VALUES (i
)->next
, e
);
2033 slot
= cselib_find_slot (x
, e
->hash
, INSERT
, memmode
);
2039 return cselib_lookup_mem (x
, create
);
2041 hashval
= cselib_hash_rtx (x
, create
, memmode
);
2042 /* Can't even create if hashing is not possible. */
2046 slot
= cselib_find_slot (wrap_constant (mode
, x
), hashval
,
2047 create
? INSERT
: NO_INSERT
, memmode
);
2051 e
= (cselib_val
*) *slot
;
2055 e
= new_cselib_val (hashval
, mode
, x
);
2057 /* We have to fill the slot before calling cselib_subst_to_values:
2058 the hash table is inconsistent until we do so, and
2059 cselib_subst_to_values will need to do lookups. */
2061 new_elt_loc_list (e
, cselib_subst_to_values (x
, memmode
));
2065 /* Wrapper for cselib_lookup, that indicates X is in INSN. */
2068 cselib_lookup_from_insn (rtx x
, enum machine_mode mode
,
2069 int create
, enum machine_mode memmode
, rtx insn
)
2073 gcc_assert (!cselib_current_insn
);
2074 cselib_current_insn
= insn
;
2076 ret
= cselib_lookup (x
, mode
, create
, memmode
);
2078 cselib_current_insn
= NULL
;
2083 /* Wrapper for cselib_lookup_1, that logs the lookup result and
2084 maintains invariants related with debug insns. */
2087 cselib_lookup (rtx x
, enum machine_mode mode
,
2088 int create
, enum machine_mode memmode
)
2090 cselib_val
*ret
= cselib_lookup_1 (x
, mode
, create
, memmode
);
2092 /* ??? Should we return NULL if we're not to create an entry, the
2093 found loc is a debug loc and cselib_current_insn is not DEBUG?
2094 If so, we should also avoid converting val to non-DEBUG; probably
2095 easiest setting cselib_current_insn to NULL before the call
2098 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
2100 fputs ("cselib lookup ", dump_file
);
2101 print_inline_rtx (dump_file
, x
, 2);
2102 fprintf (dump_file
, " => %u:%u\n",
2104 ret
? ret
->hash
: 0);
2110 /* Invalidate any entries in reg_values that overlap REGNO. This is called
2111 if REGNO is changing. MODE is the mode of the assignment to REGNO, which
2112 is used to determine how many hard registers are being changed. If MODE
2113 is VOIDmode, then only REGNO is being changed; this is used when
2114 invalidating call clobbered registers across a call. */
2117 cselib_invalidate_regno (unsigned int regno
, enum machine_mode mode
)
2119 unsigned int endregno
;
2122 /* If we see pseudos after reload, something is _wrong_. */
2123 gcc_assert (!reload_completed
|| regno
< FIRST_PSEUDO_REGISTER
2124 || reg_renumber
[regno
] < 0);
2126 /* Determine the range of registers that must be invalidated. For
2127 pseudos, only REGNO is affected. For hard regs, we must take MODE
2128 into account, and we must also invalidate lower register numbers
2129 if they contain values that overlap REGNO. */
2130 if (regno
< FIRST_PSEUDO_REGISTER
)
2132 gcc_assert (mode
!= VOIDmode
);
2134 if (regno
< max_value_regs
)
2137 i
= regno
- max_value_regs
;
2139 endregno
= end_hard_regno (mode
, regno
);
2144 endregno
= regno
+ 1;
2147 for (; i
< endregno
; i
++)
2149 struct elt_list
**l
= ®_VALUES (i
);
2151 /* Go through all known values for this reg; if it overlaps the range
2152 we're invalidating, remove the value. */
2155 cselib_val
*v
= (*l
)->elt
;
2158 struct elt_loc_list
**p
;
2159 unsigned int this_last
= i
;
2161 if (i
< FIRST_PSEUDO_REGISTER
&& v
!= NULL
)
2162 this_last
= end_hard_regno (GET_MODE (v
->val_rtx
), i
) - 1;
2164 if (this_last
< regno
|| v
== NULL
2165 || (v
== cfa_base_preserved_val
2166 && i
== cfa_base_preserved_regno
))
2172 /* We have an overlap. */
2173 if (*l
== REG_VALUES (i
))
2175 /* Maintain the invariant that the first entry of
2176 REG_VALUES, if present, must be the value used to set
2177 the register, or NULL. This is also nice because
2178 then we won't push the same regno onto user_regs
2184 unchain_one_elt_list (l
);
2186 v
= canonical_cselib_val (v
);
2188 had_locs
= v
->locs
!= NULL
;
2189 setting_insn
= v
->locs
? v
->locs
->setting_insn
: NULL
;
2191 /* Now, we clear the mapping from value to reg. It must exist, so
2192 this code will crash intentionally if it doesn't. */
2193 for (p
= &v
->locs
; ; p
= &(*p
)->next
)
2197 if (REG_P (x
) && REGNO (x
) == i
)
2199 unchain_one_elt_loc_list (p
);
2204 if (had_locs
&& v
->locs
== 0 && !PRESERVED_VALUE_P (v
->val_rtx
))
2206 if (setting_insn
&& DEBUG_INSN_P (setting_insn
))
2207 n_useless_debug_values
++;
2215 /* Invalidate any locations in the table which are changed because of a
2216 store to MEM_RTX. If this is called because of a non-const call
2217 instruction, MEM_RTX is (mem:BLK const0_rtx). */
2220 cselib_invalidate_mem (rtx mem_rtx
)
2222 cselib_val
**vp
, *v
, *next
;
2226 mem_addr
= canon_rtx (get_addr (XEXP (mem_rtx
, 0)));
2227 mem_rtx
= canon_rtx (mem_rtx
);
2229 vp
= &first_containing_mem
;
2230 for (v
= *vp
; v
!= &dummy_val
; v
= next
)
2232 bool has_mem
= false;
2233 struct elt_loc_list
**p
= &v
->locs
;
2234 bool had_locs
= v
->locs
!= NULL
;
2235 rtx setting_insn
= v
->locs
? v
->locs
->setting_insn
: NULL
;
2241 struct elt_list
**mem_chain
;
2243 /* MEMs may occur in locations only at the top level; below
2244 that every MEM or REG is substituted by its VALUE. */
2250 if (num_mems
< PARAM_VALUE (PARAM_MAX_CSELIB_MEMORY_LOCATIONS
)
2251 && ! canon_true_dependence (mem_rtx
, GET_MODE (mem_rtx
),
2252 mem_addr
, x
, NULL_RTX
))
2260 /* This one overlaps. */
2261 /* We must have a mapping from this MEM's address to the
2262 value (E). Remove that, too. */
2263 addr
= cselib_lookup (XEXP (x
, 0), VOIDmode
, 0, GET_MODE (x
));
2264 addr
= canonical_cselib_val (addr
);
2265 gcc_checking_assert (v
== canonical_cselib_val (v
));
2266 mem_chain
= &addr
->addr_list
;
2269 cselib_val
*canon
= canonical_cselib_val ((*mem_chain
)->elt
);
2273 unchain_one_elt_list (mem_chain
);
2277 /* Record canonicalized elt. */
2278 (*mem_chain
)->elt
= canon
;
2280 mem_chain
= &(*mem_chain
)->next
;
2283 unchain_one_elt_loc_list (p
);
2286 if (had_locs
&& v
->locs
== 0 && !PRESERVED_VALUE_P (v
->val_rtx
))
2288 if (setting_insn
&& DEBUG_INSN_P (setting_insn
))
2289 n_useless_debug_values
++;
2294 next
= v
->next_containing_mem
;
2298 vp
= &(*vp
)->next_containing_mem
;
2301 v
->next_containing_mem
= NULL
;
2306 /* Invalidate DEST, which is being assigned to or clobbered. */
2309 cselib_invalidate_rtx (rtx dest
)
2311 while (GET_CODE (dest
) == SUBREG
2312 || GET_CODE (dest
) == ZERO_EXTRACT
2313 || GET_CODE (dest
) == STRICT_LOW_PART
)
2314 dest
= XEXP (dest
, 0);
2317 cselib_invalidate_regno (REGNO (dest
), GET_MODE (dest
));
2318 else if (MEM_P (dest
))
2319 cselib_invalidate_mem (dest
);
2322 /* A wrapper for cselib_invalidate_rtx to be called via note_stores. */
2325 cselib_invalidate_rtx_note_stores (rtx dest
, const_rtx ignore ATTRIBUTE_UNUSED
,
2326 void *data ATTRIBUTE_UNUSED
)
2328 cselib_invalidate_rtx (dest
);
2331 /* Record the result of a SET instruction. DEST is being set; the source
2332 contains the value described by SRC_ELT. If DEST is a MEM, DEST_ADDR_ELT
2333 describes its address. */
2336 cselib_record_set (rtx dest
, cselib_val
*src_elt
, cselib_val
*dest_addr_elt
)
2338 int dreg
= REG_P (dest
) ? (int) REGNO (dest
) : -1;
2340 if (src_elt
== 0 || side_effects_p (dest
))
2345 if (dreg
< FIRST_PSEUDO_REGISTER
)
2347 unsigned int n
= hard_regno_nregs
[dreg
][GET_MODE (dest
)];
2349 if (n
> max_value_regs
)
2353 if (REG_VALUES (dreg
) == 0)
2355 used_regs
[n_used_regs
++] = dreg
;
2356 REG_VALUES (dreg
) = new_elt_list (REG_VALUES (dreg
), src_elt
);
2360 /* The register should have been invalidated. */
2361 gcc_assert (REG_VALUES (dreg
)->elt
== 0);
2362 REG_VALUES (dreg
)->elt
= src_elt
;
2365 if (src_elt
->locs
== 0 && !PRESERVED_VALUE_P (src_elt
->val_rtx
))
2367 new_elt_loc_list (src_elt
, dest
);
2369 else if (MEM_P (dest
) && dest_addr_elt
!= 0
2370 && cselib_record_memory
)
2372 if (src_elt
->locs
== 0 && !PRESERVED_VALUE_P (src_elt
->val_rtx
))
2374 add_mem_for_addr (dest_addr_elt
, src_elt
, dest
);
2378 /* Make ELT and X's VALUE equivalent to each other at INSN. */
2381 cselib_add_permanent_equiv (cselib_val
*elt
, rtx x
, rtx insn
)
2384 rtx save_cselib_current_insn
= cselib_current_insn
;
2386 gcc_checking_assert (elt
);
2387 gcc_checking_assert (PRESERVED_VALUE_P (elt
->val_rtx
));
2388 gcc_checking_assert (!side_effects_p (x
));
2390 cselib_current_insn
= insn
;
2392 nelt
= cselib_lookup (x
, GET_MODE (elt
->val_rtx
), 1, VOIDmode
);
2396 cselib_any_perm_equivs
= true;
2398 if (!PRESERVED_VALUE_P (nelt
->val_rtx
))
2399 cselib_preserve_value (nelt
);
2401 new_elt_loc_list (nelt
, elt
->val_rtx
);
2404 cselib_current_insn
= save_cselib_current_insn
;
2407 /* Return TRUE if any permanent equivalences have been recorded since
2408 the table was last initialized. */
2410 cselib_have_permanent_equivalences (void)
2412 return cselib_any_perm_equivs
;
2415 /* There is no good way to determine how many elements there can be
2416 in a PARALLEL. Since it's fairly cheap, use a really large number. */
2417 #define MAX_SETS (FIRST_PSEUDO_REGISTER * 2)
2419 struct cselib_record_autoinc_data
2421 struct cselib_set
*sets
;
2425 /* Callback for for_each_inc_dec. Records in ARG the SETs implied by
2426 autoinc RTXs: SRC plus SRCOFF if non-NULL is stored in DEST. */
2429 cselib_record_autoinc_cb (rtx mem ATTRIBUTE_UNUSED
, rtx op ATTRIBUTE_UNUSED
,
2430 rtx dest
, rtx src
, rtx srcoff
, void *arg
)
2432 struct cselib_record_autoinc_data
*data
;
2433 data
= (struct cselib_record_autoinc_data
*)arg
;
2435 data
->sets
[data
->n_sets
].dest
= dest
;
2438 data
->sets
[data
->n_sets
].src
= gen_rtx_PLUS (GET_MODE (src
), src
, srcoff
);
2440 data
->sets
[data
->n_sets
].src
= src
;
2447 /* Record the effects of any sets and autoincs in INSN. */
2449 cselib_record_sets (rtx insn
)
2453 struct cselib_set sets
[MAX_SETS
];
2454 rtx body
= PATTERN (insn
);
2456 int n_sets_before_autoinc
;
2457 struct cselib_record_autoinc_data data
;
2459 body
= PATTERN (insn
);
2460 if (GET_CODE (body
) == COND_EXEC
)
2462 cond
= COND_EXEC_TEST (body
);
2463 body
= COND_EXEC_CODE (body
);
2466 /* Find all sets. */
2467 if (GET_CODE (body
) == SET
)
2469 sets
[0].src
= SET_SRC (body
);
2470 sets
[0].dest
= SET_DEST (body
);
2473 else if (GET_CODE (body
) == PARALLEL
)
2475 /* Look through the PARALLEL and record the values being
2476 set, if possible. Also handle any CLOBBERs. */
2477 for (i
= XVECLEN (body
, 0) - 1; i
>= 0; --i
)
2479 rtx x
= XVECEXP (body
, 0, i
);
2481 if (GET_CODE (x
) == SET
)
2483 sets
[n_sets
].src
= SET_SRC (x
);
2484 sets
[n_sets
].dest
= SET_DEST (x
);
2491 && MEM_P (sets
[0].src
)
2492 && !cselib_record_memory
2493 && MEM_READONLY_P (sets
[0].src
))
2495 rtx note
= find_reg_equal_equiv_note (insn
);
2497 if (note
&& CONSTANT_P (XEXP (note
, 0)))
2498 sets
[0].src
= XEXP (note
, 0);
2502 data
.n_sets
= n_sets_before_autoinc
= n_sets
;
2503 for_each_inc_dec (&insn
, cselib_record_autoinc_cb
, &data
);
2504 n_sets
= data
.n_sets
;
2506 /* Look up the values that are read. Do this before invalidating the
2507 locations that are written. */
2508 for (i
= 0; i
< n_sets
; i
++)
2510 rtx dest
= sets
[i
].dest
;
2512 /* A STRICT_LOW_PART can be ignored; we'll record the equivalence for
2513 the low part after invalidating any knowledge about larger modes. */
2514 if (GET_CODE (sets
[i
].dest
) == STRICT_LOW_PART
)
2515 sets
[i
].dest
= dest
= XEXP (dest
, 0);
2517 /* We don't know how to record anything but REG or MEM. */
2519 || (MEM_P (dest
) && cselib_record_memory
))
2521 rtx src
= sets
[i
].src
;
2523 src
= gen_rtx_IF_THEN_ELSE (GET_MODE (dest
), cond
, src
, dest
);
2524 sets
[i
].src_elt
= cselib_lookup (src
, GET_MODE (dest
), 1, VOIDmode
);
2527 enum machine_mode address_mode
= get_address_mode (dest
);
2529 sets
[i
].dest_addr_elt
= cselib_lookup (XEXP (dest
, 0),
2534 sets
[i
].dest_addr_elt
= 0;
2538 if (cselib_record_sets_hook
)
2539 cselib_record_sets_hook (insn
, sets
, n_sets
);
2541 /* Invalidate all locations written by this insn. Note that the elts we
2542 looked up in the previous loop aren't affected, just some of their
2543 locations may go away. */
2544 note_stores (body
, cselib_invalidate_rtx_note_stores
, NULL
);
2546 for (i
= n_sets_before_autoinc
; i
< n_sets
; i
++)
2547 cselib_invalidate_rtx (sets
[i
].dest
);
2549 /* If this is an asm, look for duplicate sets. This can happen when the
2550 user uses the same value as an output multiple times. This is valid
2551 if the outputs are not actually used thereafter. Treat this case as
2552 if the value isn't actually set. We do this by smashing the destination
2553 to pc_rtx, so that we won't record the value later. */
2554 if (n_sets
>= 2 && asm_noperands (body
) >= 0)
2556 for (i
= 0; i
< n_sets
; i
++)
2558 rtx dest
= sets
[i
].dest
;
2559 if (REG_P (dest
) || MEM_P (dest
))
2562 for (j
= i
+ 1; j
< n_sets
; j
++)
2563 if (rtx_equal_p (dest
, sets
[j
].dest
))
2565 sets
[i
].dest
= pc_rtx
;
2566 sets
[j
].dest
= pc_rtx
;
2572 /* Now enter the equivalences in our tables. */
2573 for (i
= 0; i
< n_sets
; i
++)
2575 rtx dest
= sets
[i
].dest
;
2577 || (MEM_P (dest
) && cselib_record_memory
))
2578 cselib_record_set (dest
, sets
[i
].src_elt
, sets
[i
].dest_addr_elt
);
2582 /* Record the effects of INSN. */
2585 cselib_process_insn (rtx insn
)
2590 cselib_current_insn
= insn
;
2592 /* Forget everything at a CODE_LABEL, a volatile asm, or a setjmp. */
2595 && find_reg_note (insn
, REG_SETJMP
, NULL
))
2596 || (NONJUMP_INSN_P (insn
)
2597 && GET_CODE (PATTERN (insn
)) == ASM_OPERANDS
2598 && MEM_VOLATILE_P (PATTERN (insn
))))
2600 cselib_reset_table (next_uid
);
2601 cselib_current_insn
= NULL_RTX
;
2605 if (! INSN_P (insn
))
2607 cselib_current_insn
= NULL_RTX
;
2611 /* If this is a call instruction, forget anything stored in a
2612 call clobbered register, or, if this is not a const call, in
2616 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; i
++)
2617 if (call_used_regs
[i
]
2618 || (REG_VALUES (i
) && REG_VALUES (i
)->elt
2619 && HARD_REGNO_CALL_PART_CLOBBERED (i
,
2620 GET_MODE (REG_VALUES (i
)->elt
->val_rtx
))))
2621 cselib_invalidate_regno (i
, reg_raw_mode
[i
]);
2623 /* Since it is not clear how cselib is going to be used, be
2624 conservative here and treat looping pure or const functions
2625 as if they were regular functions. */
2626 if (RTL_LOOPING_CONST_OR_PURE_CALL_P (insn
)
2627 || !(RTL_CONST_OR_PURE_CALL_P (insn
)))
2628 cselib_invalidate_mem (callmem
);
2631 cselib_record_sets (insn
);
2633 /* Look for any CLOBBERs in CALL_INSN_FUNCTION_USAGE, but only
2634 after we have processed the insn. */
2636 for (x
= CALL_INSN_FUNCTION_USAGE (insn
); x
; x
= XEXP (x
, 1))
2637 if (GET_CODE (XEXP (x
, 0)) == CLOBBER
)
2638 cselib_invalidate_rtx (XEXP (XEXP (x
, 0), 0));
2640 cselib_current_insn
= NULL_RTX
;
2642 if (n_useless_values
> MAX_USELESS_VALUES
2643 /* remove_useless_values is linear in the hash table size. Avoid
2644 quadratic behavior for very large hashtables with very few
2645 useless elements. */
2646 && ((unsigned int)n_useless_values
2647 > (cselib_hash_table
->n_elements
2648 - cselib_hash_table
->n_deleted
2649 - n_debug_values
) / 4))
2650 remove_useless_values ();
2653 /* Initialize cselib for one pass. The caller must also call
2654 init_alias_analysis. */
2657 cselib_init (int record_what
)
2659 elt_list_pool
= create_alloc_pool ("elt_list",
2660 sizeof (struct elt_list
), 10);
2661 elt_loc_list_pool
= create_alloc_pool ("elt_loc_list",
2662 sizeof (struct elt_loc_list
), 10);
2663 cselib_val_pool
= create_alloc_pool ("cselib_val_list",
2664 sizeof (cselib_val
), 10);
2665 value_pool
= create_alloc_pool ("value", RTX_CODE_SIZE (VALUE
), 100);
2666 cselib_record_memory
= record_what
& CSELIB_RECORD_MEMORY
;
2667 cselib_preserve_constants
= record_what
& CSELIB_PRESERVE_CONSTANTS
;
2668 cselib_any_perm_equivs
= false;
2670 /* (mem:BLK (scratch)) is a special mechanism to conflict with everything,
2671 see canon_true_dependence. This is only created once. */
2673 callmem
= gen_rtx_MEM (BLKmode
, gen_rtx_SCRATCH (VOIDmode
));
2675 cselib_nregs
= max_reg_num ();
2677 /* We preserve reg_values to allow expensive clearing of the whole thing.
2678 Reallocate it however if it happens to be too large. */
2679 if (!reg_values
|| reg_values_size
< cselib_nregs
2680 || (reg_values_size
> 10 && reg_values_size
> cselib_nregs
* 4))
2683 /* Some space for newly emit instructions so we don't end up
2684 reallocating in between passes. */
2685 reg_values_size
= cselib_nregs
+ (63 + cselib_nregs
) / 16;
2686 reg_values
= XCNEWVEC (struct elt_list
*, reg_values_size
);
2688 used_regs
= XNEWVEC (unsigned int, cselib_nregs
);
2690 cselib_hash_table
= htab_create (31, get_value_hash
,
2691 entry_and_rtx_equal_p
, NULL
);
2695 /* Called when the current user is done with cselib. */
2698 cselib_finish (void)
2700 cselib_discard_hook
= NULL
;
2701 cselib_preserve_constants
= false;
2702 cselib_any_perm_equivs
= false;
2703 cfa_base_preserved_val
= NULL
;
2704 cfa_base_preserved_regno
= INVALID_REGNUM
;
2705 free_alloc_pool (elt_list_pool
);
2706 free_alloc_pool (elt_loc_list_pool
);
2707 free_alloc_pool (cselib_val_pool
);
2708 free_alloc_pool (value_pool
);
2709 cselib_clear_table ();
2710 htab_delete (cselib_hash_table
);
2713 cselib_hash_table
= 0;
2714 n_useless_values
= 0;
2715 n_useless_debug_values
= 0;
2720 /* Dump the cselib_val *X to FILE *info. */
2723 dump_cselib_val (void **x
, void *info
)
2725 cselib_val
*v
= (cselib_val
*)*x
;
2726 FILE *out
= (FILE *)info
;
2727 bool need_lf
= true;
2729 print_inline_rtx (out
, v
->val_rtx
, 0);
2733 struct elt_loc_list
*l
= v
->locs
;
2739 fputs (" locs:", out
);
2742 if (l
->setting_insn
)
2743 fprintf (out
, "\n from insn %i ",
2744 INSN_UID (l
->setting_insn
));
2746 fprintf (out
, "\n ");
2747 print_inline_rtx (out
, l
->loc
, 4);
2749 while ((l
= l
->next
));
2754 fputs (" no locs", out
);
2760 struct elt_list
*e
= v
->addr_list
;
2766 fputs (" addr list:", out
);
2770 print_inline_rtx (out
, e
->elt
->val_rtx
, 2);
2772 while ((e
= e
->next
));
2777 fputs (" no addrs", out
);
2781 if (v
->next_containing_mem
== &dummy_val
)
2782 fputs (" last mem\n", out
);
2783 else if (v
->next_containing_mem
)
2785 fputs (" next mem ", out
);
2786 print_inline_rtx (out
, v
->next_containing_mem
->val_rtx
, 2);
2795 /* Dump to OUT everything in the CSELIB table. */
2798 dump_cselib_table (FILE *out
)
2800 fprintf (out
, "cselib hash table:\n");
2801 htab_traverse (cselib_hash_table
, dump_cselib_val
, out
);
2802 if (first_containing_mem
!= &dummy_val
)
2804 fputs ("first mem ", out
);
2805 print_inline_rtx (out
, first_containing_mem
->val_rtx
, 2);
2808 fprintf (out
, "next uid %i\n", next_uid
);
2811 #include "gt-cselib.h"