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"
39 #include "tree-pass.h"
42 #include "alloc-pool.h"
46 /* A list of cselib_val structures. */
48 struct elt_list
*next
;
52 static bool cselib_record_memory
;
53 static bool cselib_preserve_constants
;
54 static bool cselib_any_perm_equivs
;
55 static int entry_and_rtx_equal_p (const void *, const void *);
56 static hashval_t
get_value_hash (const void *);
57 static struct elt_list
*new_elt_list (struct elt_list
*, cselib_val
*);
58 static void new_elt_loc_list (cselib_val
*, rtx
);
59 static void unchain_one_value (cselib_val
*);
60 static void unchain_one_elt_list (struct elt_list
**);
61 static void unchain_one_elt_loc_list (struct elt_loc_list
**);
62 static int discard_useless_locs (void **, void *);
63 static int discard_useless_values (void **, void *);
64 static void remove_useless_values (void);
65 static int rtx_equal_for_cselib_1 (rtx
, rtx
, enum machine_mode
);
66 static unsigned int cselib_hash_rtx (rtx
, int, enum machine_mode
);
67 static cselib_val
*new_cselib_val (unsigned int, enum machine_mode
, rtx
);
68 static void add_mem_for_addr (cselib_val
*, cselib_val
*, rtx
);
69 static cselib_val
*cselib_lookup_mem (rtx
, int);
70 static void cselib_invalidate_regno (unsigned int, enum machine_mode
);
71 static void cselib_invalidate_mem (rtx
);
72 static void cselib_record_set (rtx
, cselib_val
*, cselib_val
*);
73 static void cselib_record_sets (rtx
);
75 struct expand_value_data
78 cselib_expand_callback callback
;
83 static rtx
cselib_expand_value_rtx_1 (rtx
, struct expand_value_data
*, int);
85 /* There are three ways in which cselib can look up an rtx:
86 - for a REG, the reg_values table (which is indexed by regno) is used
87 - for a MEM, we recursively look up its address and then follow the
88 addr_list of that value
89 - for everything else, we compute a hash value and go through the hash
90 table. Since different rtx's can still have the same hash value,
91 this involves walking the table entries for a given value and comparing
92 the locations of the entries with the rtx we are looking up. */
94 /* A table that enables us to look up elts by their value. */
95 static htab_t cselib_hash_table
;
97 /* This is a global so we don't have to pass this through every function.
98 It is used in new_elt_loc_list to set SETTING_INSN. */
99 static rtx cselib_current_insn
;
101 /* The unique id that the next create value will take. */
102 static unsigned int next_uid
;
104 /* The number of registers we had when the varrays were last resized. */
105 static unsigned int cselib_nregs
;
107 /* Count values without known locations, or with only locations that
108 wouldn't have been known except for debug insns. Whenever this
109 grows too big, we remove these useless values from the table.
111 Counting values with only debug values is a bit tricky. We don't
112 want to increment n_useless_values when we create a value for a
113 debug insn, for this would get n_useless_values out of sync, but we
114 want increment it if all locs in the list that were ever referenced
115 in nondebug insns are removed from the list.
117 In the general case, once we do that, we'd have to stop accepting
118 nondebug expressions in the loc list, to avoid having two values
119 equivalent that, without debug insns, would have been made into
120 separate values. However, because debug insns never introduce
121 equivalences themselves (no assignments), the only means for
122 growing loc lists is through nondebug assignments. If the locs
123 also happen to be referenced in debug insns, it will work just fine.
125 A consequence of this is that there's at most one debug-only loc in
126 each loc list. If we keep it in the first entry, testing whether
127 we have a debug-only loc list takes O(1).
129 Furthermore, since any additional entry in a loc list containing a
130 debug loc would have to come from an assignment (nondebug) that
131 references both the initial debug loc and the newly-equivalent loc,
132 the initial debug loc would be promoted to a nondebug loc, and the
133 loc list would not contain debug locs any more.
135 So the only case we have to be careful with in order to keep
136 n_useless_values in sync between debug and nondebug compilations is
137 to avoid incrementing n_useless_values when removing the single loc
138 from a value that turns out to not appear outside debug values. We
139 increment n_useless_debug_values instead, and leave such values
140 alone until, for other reasons, we garbage-collect useless
142 static int n_useless_values
;
143 static int n_useless_debug_values
;
145 /* Count values whose locs have been taken exclusively from debug
146 insns for the entire life of the value. */
147 static int n_debug_values
;
149 /* Number of useless values before we remove them from the hash table. */
150 #define MAX_USELESS_VALUES 32
152 /* This table maps from register number to values. It does not
153 contain pointers to cselib_val structures, but rather elt_lists.
154 The purpose is to be able to refer to the same register in
155 different modes. The first element of the list defines the mode in
156 which the register was set; if the mode is unknown or the value is
157 no longer valid in that mode, ELT will be NULL for the first
159 static struct elt_list
**reg_values
;
160 static unsigned int reg_values_size
;
161 #define REG_VALUES(i) reg_values[i]
163 /* The largest number of hard regs used by any entry added to the
164 REG_VALUES table. Cleared on each cselib_clear_table() invocation. */
165 static unsigned int max_value_regs
;
167 /* Here the set of indices I with REG_VALUES(I) != 0 is saved. This is used
168 in cselib_clear_table() for fast emptying. */
169 static unsigned int *used_regs
;
170 static unsigned int n_used_regs
;
172 /* We pass this to cselib_invalidate_mem to invalidate all of
173 memory for a non-const call instruction. */
174 static GTY(()) rtx callmem
;
176 /* Set by discard_useless_locs if it deleted the last location of any
178 static int values_became_useless
;
180 /* Used as stop element of the containing_mem list so we can check
181 presence in the list by checking the next pointer. */
182 static cselib_val dummy_val
;
184 /* If non-NULL, value of the eliminated arg_pointer_rtx or frame_pointer_rtx
185 that is constant through the whole function and should never be
187 static cselib_val
*cfa_base_preserved_val
;
188 static unsigned int cfa_base_preserved_regno
= INVALID_REGNUM
;
190 /* Used to list all values that contain memory reference.
191 May or may not contain the useless values - the list is compacted
192 each time memory is invalidated. */
193 static cselib_val
*first_containing_mem
= &dummy_val
;
194 static alloc_pool elt_loc_list_pool
, elt_list_pool
, cselib_val_pool
, value_pool
;
196 /* If nonnull, cselib will call this function before freeing useless
197 VALUEs. A VALUE is deemed useless if its "locs" field is null. */
198 void (*cselib_discard_hook
) (cselib_val
*);
200 /* If nonnull, cselib will call this function before recording sets or
201 even clobbering outputs of INSN. All the recorded sets will be
202 represented in the array sets[n_sets]. new_val_min can be used to
203 tell whether values present in sets are introduced by this
205 void (*cselib_record_sets_hook
) (rtx insn
, struct cselib_set
*sets
,
208 #define PRESERVED_VALUE_P(RTX) \
209 (RTL_FLAG_CHECK1("PRESERVED_VALUE_P", (RTX), VALUE)->unchanging)
213 /* Allocate a struct elt_list and fill in its two elements with the
216 static inline struct elt_list
*
217 new_elt_list (struct elt_list
*next
, cselib_val
*elt
)
220 el
= (struct elt_list
*) pool_alloc (elt_list_pool
);
226 /* Allocate a struct elt_loc_list with LOC and prepend it to VAL's loc
230 new_elt_loc_list (cselib_val
*val
, rtx loc
)
232 struct elt_loc_list
*el
, *next
= val
->locs
;
234 gcc_checking_assert (!next
|| !next
->setting_insn
235 || !DEBUG_INSN_P (next
->setting_insn
)
236 || cselib_current_insn
== next
->setting_insn
);
238 /* If we're creating the first loc in a debug insn context, we've
239 just created a debug value. Count it. */
240 if (!next
&& cselib_current_insn
&& DEBUG_INSN_P (cselib_current_insn
))
243 val
= canonical_cselib_val (val
);
246 if (GET_CODE (loc
) == VALUE
)
248 loc
= canonical_cselib_val (CSELIB_VAL_PTR (loc
))->val_rtx
;
250 gcc_checking_assert (PRESERVED_VALUE_P (loc
)
251 == PRESERVED_VALUE_P (val
->val_rtx
));
253 if (val
->val_rtx
== loc
)
255 else if (val
->uid
> CSELIB_VAL_PTR (loc
)->uid
)
257 /* Reverse the insertion. */
258 new_elt_loc_list (CSELIB_VAL_PTR (loc
), val
->val_rtx
);
262 gcc_checking_assert (val
->uid
< CSELIB_VAL_PTR (loc
)->uid
);
264 if (CSELIB_VAL_PTR (loc
)->locs
)
266 /* Bring all locs from LOC to VAL. */
267 for (el
= CSELIB_VAL_PTR (loc
)->locs
; el
->next
; el
= el
->next
)
269 /* Adjust values that have LOC as canonical so that VAL
270 becomes their canonical. */
271 if (el
->loc
&& GET_CODE (el
->loc
) == VALUE
)
273 gcc_checking_assert (CSELIB_VAL_PTR (el
->loc
)->locs
->loc
275 CSELIB_VAL_PTR (el
->loc
)->locs
->loc
= val
->val_rtx
;
278 el
->next
= val
->locs
;
279 next
= val
->locs
= CSELIB_VAL_PTR (loc
)->locs
;
282 if (CSELIB_VAL_PTR (loc
)->addr_list
)
284 /* Bring in addr_list into canonical node. */
285 struct elt_list
*last
= CSELIB_VAL_PTR (loc
)->addr_list
;
288 last
->next
= val
->addr_list
;
289 val
->addr_list
= CSELIB_VAL_PTR (loc
)->addr_list
;
290 CSELIB_VAL_PTR (loc
)->addr_list
= NULL
;
293 if (CSELIB_VAL_PTR (loc
)->next_containing_mem
!= NULL
294 && val
->next_containing_mem
== NULL
)
296 /* Add VAL to the containing_mem list after LOC. LOC will
297 be removed when we notice it doesn't contain any
299 val
->next_containing_mem
= CSELIB_VAL_PTR (loc
)->next_containing_mem
;
300 CSELIB_VAL_PTR (loc
)->next_containing_mem
= val
;
303 /* Chain LOC back to VAL. */
304 el
= (struct elt_loc_list
*) pool_alloc (elt_loc_list_pool
);
305 el
->loc
= val
->val_rtx
;
306 el
->setting_insn
= cselib_current_insn
;
308 CSELIB_VAL_PTR (loc
)->locs
= el
;
311 el
= (struct elt_loc_list
*) pool_alloc (elt_loc_list_pool
);
313 el
->setting_insn
= cselib_current_insn
;
318 /* Promote loc L to a nondebug cselib_current_insn if L is marked as
319 originating from a debug insn, maintaining the debug values
323 promote_debug_loc (struct elt_loc_list
*l
)
325 if (l
&& l
->setting_insn
&& DEBUG_INSN_P (l
->setting_insn
)
326 && (!cselib_current_insn
|| !DEBUG_INSN_P (cselib_current_insn
)))
329 l
->setting_insn
= cselib_current_insn
;
330 if (cselib_preserve_constants
&& l
->next
)
332 gcc_assert (l
->next
->setting_insn
333 && DEBUG_INSN_P (l
->next
->setting_insn
)
335 l
->next
->setting_insn
= cselib_current_insn
;
338 gcc_assert (!l
->next
);
342 /* The elt_list at *PL is no longer needed. Unchain it and free its
346 unchain_one_elt_list (struct elt_list
**pl
)
348 struct elt_list
*l
= *pl
;
351 pool_free (elt_list_pool
, l
);
354 /* Likewise for elt_loc_lists. */
357 unchain_one_elt_loc_list (struct elt_loc_list
**pl
)
359 struct elt_loc_list
*l
= *pl
;
362 pool_free (elt_loc_list_pool
, l
);
365 /* Likewise for cselib_vals. This also frees the addr_list associated with
369 unchain_one_value (cselib_val
*v
)
372 unchain_one_elt_list (&v
->addr_list
);
374 pool_free (cselib_val_pool
, v
);
377 /* Remove all entries from the hash table. Also used during
381 cselib_clear_table (void)
383 cselib_reset_table (1);
386 /* Return TRUE if V is a constant, a function invariant or a VALUE
387 equivalence; FALSE otherwise. */
390 invariant_or_equiv_p (cselib_val
*v
)
392 struct elt_loc_list
*l
;
394 if (v
== cfa_base_preserved_val
)
397 /* Keep VALUE equivalences around. */
398 for (l
= v
->locs
; l
; l
= l
->next
)
399 if (GET_CODE (l
->loc
) == VALUE
)
403 && v
->locs
->next
== NULL
)
405 if (CONSTANT_P (v
->locs
->loc
)
406 && (GET_CODE (v
->locs
->loc
) != CONST
407 || !references_value_p (v
->locs
->loc
, 0)))
409 /* Although a debug expr may be bound to different expressions,
410 we can preserve it as if it was constant, to get unification
411 and proper merging within var-tracking. */
412 if (GET_CODE (v
->locs
->loc
) == DEBUG_EXPR
413 || GET_CODE (v
->locs
->loc
) == DEBUG_IMPLICIT_PTR
414 || GET_CODE (v
->locs
->loc
) == ENTRY_VALUE
415 || GET_CODE (v
->locs
->loc
) == DEBUG_PARAMETER_REF
)
418 /* (plus (value V) (const_int C)) is invariant iff V is invariant. */
419 if (GET_CODE (v
->locs
->loc
) == PLUS
420 && CONST_INT_P (XEXP (v
->locs
->loc
, 1))
421 && GET_CODE (XEXP (v
->locs
->loc
, 0)) == VALUE
422 && invariant_or_equiv_p (CSELIB_VAL_PTR (XEXP (v
->locs
->loc
, 0))))
429 /* Remove from hash table all VALUEs except constants, function
430 invariants and VALUE equivalences. */
433 preserve_constants_and_equivs (void **x
, void *info ATTRIBUTE_UNUSED
)
435 cselib_val
*v
= (cselib_val
*)*x
;
437 if (!invariant_or_equiv_p (v
))
438 htab_clear_slot (cselib_hash_table
, x
);
442 /* Remove all entries from the hash table, arranging for the next
443 value to be numbered NUM. */
446 cselib_reset_table (unsigned int num
)
452 if (cfa_base_preserved_val
)
454 unsigned int regno
= cfa_base_preserved_regno
;
455 unsigned int new_used_regs
= 0;
456 for (i
= 0; i
< n_used_regs
; i
++)
457 if (used_regs
[i
] == regno
)
463 REG_VALUES (used_regs
[i
]) = 0;
464 gcc_assert (new_used_regs
== 1);
465 n_used_regs
= new_used_regs
;
466 used_regs
[0] = regno
;
468 = hard_regno_nregs
[regno
][GET_MODE (cfa_base_preserved_val
->locs
->loc
)];
472 for (i
= 0; i
< n_used_regs
; i
++)
473 REG_VALUES (used_regs
[i
]) = 0;
477 if (cselib_preserve_constants
)
478 htab_traverse (cselib_hash_table
, preserve_constants_and_equivs
, NULL
);
481 htab_empty (cselib_hash_table
);
482 gcc_checking_assert (!cselib_any_perm_equivs
);
485 n_useless_values
= 0;
486 n_useless_debug_values
= 0;
491 first_containing_mem
= &dummy_val
;
494 /* Return the number of the next value that will be generated. */
497 cselib_get_next_uid (void)
502 /* See the documentation of cselib_find_slot below. */
503 static enum machine_mode find_slot_memmode
;
505 /* Search for X, whose hashcode is HASH, in CSELIB_HASH_TABLE,
506 INSERTing if requested. When X is part of the address of a MEM,
507 MEMMODE should specify the mode of the MEM. While searching the
508 table, MEMMODE is held in FIND_SLOT_MEMMODE, so that autoinc RTXs
509 in X can be resolved. */
512 cselib_find_slot (rtx x
, hashval_t hash
, enum insert_option insert
,
513 enum machine_mode memmode
)
516 find_slot_memmode
= memmode
;
517 slot
= htab_find_slot_with_hash (cselib_hash_table
, x
, hash
, insert
);
518 find_slot_memmode
= VOIDmode
;
522 /* The equality test for our hash table. The first argument ENTRY is a table
523 element (i.e. a cselib_val), while the second arg X is an rtx. We know
524 that all callers of htab_find_slot_with_hash will wrap CONST_INTs into a
525 CONST of an appropriate mode. */
528 entry_and_rtx_equal_p (const void *entry
, const void *x_arg
)
530 struct elt_loc_list
*l
;
531 const cselib_val
*const v
= (const cselib_val
*) entry
;
532 rtx x
= CONST_CAST_RTX ((const_rtx
)x_arg
);
533 enum machine_mode mode
= GET_MODE (x
);
535 gcc_assert (!CONST_INT_P (x
) && GET_CODE (x
) != CONST_FIXED
536 && (mode
!= VOIDmode
|| GET_CODE (x
) != CONST_DOUBLE
));
538 if (mode
!= GET_MODE (v
->val_rtx
))
541 /* Unwrap X if necessary. */
542 if (GET_CODE (x
) == CONST
543 && (CONST_INT_P (XEXP (x
, 0))
544 || GET_CODE (XEXP (x
, 0)) == CONST_FIXED
545 || GET_CODE (XEXP (x
, 0)) == CONST_DOUBLE
))
548 /* We don't guarantee that distinct rtx's have different hash values,
549 so we need to do a comparison. */
550 for (l
= v
->locs
; l
; l
= l
->next
)
551 if (rtx_equal_for_cselib_1 (l
->loc
, x
, find_slot_memmode
))
553 promote_debug_loc (l
);
560 /* The hash function for our hash table. The value is always computed with
561 cselib_hash_rtx when adding an element; this function just extracts the
562 hash value from a cselib_val structure. */
565 get_value_hash (const void *entry
)
567 const cselib_val
*const v
= (const cselib_val
*) entry
;
571 /* Return true if X contains a VALUE rtx. If ONLY_USELESS is set, we
572 only return true for values which point to a cselib_val whose value
573 element has been set to zero, which implies the cselib_val will be
577 references_value_p (const_rtx x
, int only_useless
)
579 const enum rtx_code code
= GET_CODE (x
);
580 const char *fmt
= GET_RTX_FORMAT (code
);
583 if (GET_CODE (x
) == VALUE
584 && (! only_useless
||
585 (CSELIB_VAL_PTR (x
)->locs
== 0 && !PRESERVED_VALUE_P (x
))))
588 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
590 if (fmt
[i
] == 'e' && references_value_p (XEXP (x
, i
), only_useless
))
592 else if (fmt
[i
] == 'E')
593 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
594 if (references_value_p (XVECEXP (x
, i
, j
), only_useless
))
601 /* For all locations found in X, delete locations that reference useless
602 values (i.e. values without any location). Called through
606 discard_useless_locs (void **x
, void *info ATTRIBUTE_UNUSED
)
608 cselib_val
*v
= (cselib_val
*)*x
;
609 struct elt_loc_list
**p
= &v
->locs
;
610 bool had_locs
= v
->locs
!= NULL
;
611 rtx setting_insn
= v
->locs
? v
->locs
->setting_insn
: NULL
;
615 if (references_value_p ((*p
)->loc
, 1))
616 unchain_one_elt_loc_list (p
);
621 if (had_locs
&& v
->locs
== 0 && !PRESERVED_VALUE_P (v
->val_rtx
))
623 if (setting_insn
&& DEBUG_INSN_P (setting_insn
))
624 n_useless_debug_values
++;
627 values_became_useless
= 1;
632 /* If X is a value with no locations, remove it from the hashtable. */
635 discard_useless_values (void **x
, void *info ATTRIBUTE_UNUSED
)
637 cselib_val
*v
= (cselib_val
*)*x
;
639 if (v
->locs
== 0 && !PRESERVED_VALUE_P (v
->val_rtx
))
641 if (cselib_discard_hook
)
642 cselib_discard_hook (v
);
644 CSELIB_VAL_PTR (v
->val_rtx
) = NULL
;
645 htab_clear_slot (cselib_hash_table
, x
);
646 unchain_one_value (v
);
653 /* Clean out useless values (i.e. those which no longer have locations
654 associated with them) from the hash table. */
657 remove_useless_values (void)
661 /* First pass: eliminate locations that reference the value. That in
662 turn can make more values useless. */
665 values_became_useless
= 0;
666 htab_traverse (cselib_hash_table
, discard_useless_locs
, 0);
668 while (values_became_useless
);
670 /* Second pass: actually remove the values. */
672 p
= &first_containing_mem
;
673 for (v
= *p
; v
!= &dummy_val
; v
= v
->next_containing_mem
)
674 if (v
->locs
&& v
== canonical_cselib_val (v
))
677 p
= &(*p
)->next_containing_mem
;
681 n_useless_values
+= n_useless_debug_values
;
682 n_debug_values
-= n_useless_debug_values
;
683 n_useless_debug_values
= 0;
685 htab_traverse (cselib_hash_table
, discard_useless_values
, 0);
687 gcc_assert (!n_useless_values
);
690 /* Arrange for a value to not be removed from the hash table even if
691 it becomes useless. */
694 cselib_preserve_value (cselib_val
*v
)
696 PRESERVED_VALUE_P (v
->val_rtx
) = 1;
699 /* Test whether a value is preserved. */
702 cselib_preserved_value_p (cselib_val
*v
)
704 return PRESERVED_VALUE_P (v
->val_rtx
);
707 /* Arrange for a REG value to be assumed constant through the whole function,
708 never invalidated and preserved across cselib_reset_table calls. */
711 cselib_preserve_cfa_base_value (cselib_val
*v
, unsigned int regno
)
713 if (cselib_preserve_constants
715 && REG_P (v
->locs
->loc
))
717 cfa_base_preserved_val
= v
;
718 cfa_base_preserved_regno
= regno
;
722 /* Clean all non-constant expressions in the hash table, but retain
726 cselib_preserve_only_values (void)
730 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; i
++)
731 cselib_invalidate_regno (i
, reg_raw_mode
[i
]);
733 cselib_invalidate_mem (callmem
);
735 remove_useless_values ();
737 gcc_assert (first_containing_mem
== &dummy_val
);
740 /* Return the mode in which a register was last set. If X is not a
741 register, return its mode. If the mode in which the register was
742 set is not known, or the value was already clobbered, return
746 cselib_reg_set_mode (const_rtx x
)
751 if (REG_VALUES (REGNO (x
)) == NULL
752 || REG_VALUES (REGNO (x
))->elt
== NULL
)
755 return GET_MODE (REG_VALUES (REGNO (x
))->elt
->val_rtx
);
758 /* Return nonzero if we can prove that X and Y contain the same value, taking
759 our gathered information into account. */
762 rtx_equal_for_cselib_p (rtx x
, rtx y
)
764 return rtx_equal_for_cselib_1 (x
, y
, VOIDmode
);
767 /* If x is a PLUS or an autoinc operation, expand the operation,
768 storing the offset, if any, in *OFF. */
771 autoinc_split (rtx x
, rtx
*off
, enum machine_mode memmode
)
773 switch (GET_CODE (x
))
780 if (memmode
== VOIDmode
)
783 *off
= GEN_INT (-GET_MODE_SIZE (memmode
));
788 if (memmode
== VOIDmode
)
791 *off
= GEN_INT (GET_MODE_SIZE (memmode
));
807 /* Return nonzero if we can prove that X and Y contain the same value,
808 taking our gathered information into account. MEMMODE holds the
809 mode of the enclosing MEM, if any, as required to deal with autoinc
810 addressing modes. If X and Y are not (known to be) part of
811 addresses, MEMMODE should be VOIDmode. */
814 rtx_equal_for_cselib_1 (rtx x
, rtx y
, enum machine_mode memmode
)
820 if (REG_P (x
) || MEM_P (x
))
822 cselib_val
*e
= cselib_lookup (x
, GET_MODE (x
), 0, memmode
);
828 if (REG_P (y
) || MEM_P (y
))
830 cselib_val
*e
= cselib_lookup (y
, GET_MODE (y
), 0, memmode
);
839 if (GET_CODE (x
) == VALUE
)
841 cselib_val
*e
= canonical_cselib_val (CSELIB_VAL_PTR (x
));
842 struct elt_loc_list
*l
;
844 if (GET_CODE (y
) == VALUE
)
845 return e
== canonical_cselib_val (CSELIB_VAL_PTR (y
));
847 for (l
= e
->locs
; l
; l
= l
->next
)
851 /* Avoid infinite recursion. We know we have the canonical
852 value, so we can just skip any values in the equivalence
854 if (REG_P (t
) || MEM_P (t
) || GET_CODE (t
) == VALUE
)
856 else if (rtx_equal_for_cselib_1 (t
, y
, memmode
))
862 else if (GET_CODE (y
) == VALUE
)
864 cselib_val
*e
= canonical_cselib_val (CSELIB_VAL_PTR (y
));
865 struct elt_loc_list
*l
;
867 for (l
= e
->locs
; l
; l
= l
->next
)
871 if (REG_P (t
) || MEM_P (t
) || GET_CODE (t
) == VALUE
)
873 else if (rtx_equal_for_cselib_1 (x
, t
, memmode
))
880 if (GET_MODE (x
) != GET_MODE (y
))
883 if (GET_CODE (x
) != GET_CODE (y
))
885 rtx xorig
= x
, yorig
= y
;
886 rtx xoff
= NULL
, yoff
= NULL
;
888 x
= autoinc_split (x
, &xoff
, memmode
);
889 y
= autoinc_split (y
, &yoff
, memmode
);
894 if (xoff
&& !rtx_equal_for_cselib_1 (xoff
, yoff
, memmode
))
897 /* Don't recurse if nothing changed. */
898 if (x
!= xorig
|| y
!= yorig
)
899 return rtx_equal_for_cselib_1 (x
, y
, memmode
);
904 /* These won't be handled correctly by the code below. */
905 switch (GET_CODE (x
))
912 case DEBUG_IMPLICIT_PTR
:
913 return DEBUG_IMPLICIT_PTR_DECL (x
)
914 == DEBUG_IMPLICIT_PTR_DECL (y
);
916 case DEBUG_PARAMETER_REF
:
917 return DEBUG_PARAMETER_REF_DECL (x
)
918 == DEBUG_PARAMETER_REF_DECL (y
);
921 /* ENTRY_VALUEs are function invariant, it is thus undesirable to
922 use rtx_equal_for_cselib_1 to compare the operands. */
923 return rtx_equal_p (ENTRY_VALUE_EXP (x
), ENTRY_VALUE_EXP (y
));
926 return XEXP (x
, 0) == XEXP (y
, 0);
929 /* We have to compare any autoinc operations in the addresses
930 using this MEM's mode. */
931 return rtx_equal_for_cselib_1 (XEXP (x
, 0), XEXP (y
, 0), GET_MODE (x
));
938 fmt
= GET_RTX_FORMAT (code
);
940 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
947 if (XWINT (x
, i
) != XWINT (y
, i
))
953 if (XINT (x
, i
) != XINT (y
, i
))
959 /* Two vectors must have the same length. */
960 if (XVECLEN (x
, i
) != XVECLEN (y
, i
))
963 /* And the corresponding elements must match. */
964 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
965 if (! rtx_equal_for_cselib_1 (XVECEXP (x
, i
, j
),
966 XVECEXP (y
, i
, j
), memmode
))
972 && targetm
.commutative_p (x
, UNKNOWN
)
973 && rtx_equal_for_cselib_1 (XEXP (x
, 1), XEXP (y
, 0), memmode
)
974 && rtx_equal_for_cselib_1 (XEXP (x
, 0), XEXP (y
, 1), memmode
))
976 if (! rtx_equal_for_cselib_1 (XEXP (x
, i
), XEXP (y
, i
), memmode
))
982 if (strcmp (XSTR (x
, i
), XSTR (y
, i
)))
987 /* These are just backpointers, so they don't matter. */
994 /* It is believed that rtx's at this level will never
995 contain anything but integers and other rtx's,
996 except for within LABEL_REFs and SYMBOL_REFs. */
1004 /* We need to pass down the mode of constants through the hash table
1005 functions. For that purpose, wrap them in a CONST of the appropriate
1008 wrap_constant (enum machine_mode mode
, rtx x
)
1010 if (!CONST_INT_P (x
) && GET_CODE (x
) != CONST_FIXED
1011 && (GET_CODE (x
) != CONST_DOUBLE
|| GET_MODE (x
) != VOIDmode
))
1013 gcc_assert (mode
!= VOIDmode
);
1014 return gen_rtx_CONST (mode
, x
);
1017 /* Hash an rtx. Return 0 if we couldn't hash the rtx.
1018 For registers and memory locations, we look up their cselib_val structure
1019 and return its VALUE element.
1020 Possible reasons for return 0 are: the object is volatile, or we couldn't
1021 find a register or memory location in the table and CREATE is zero. If
1022 CREATE is nonzero, table elts are created for regs and mem.
1023 N.B. this hash function returns the same hash value for RTXes that
1024 differ only in the order of operands, thus it is suitable for comparisons
1025 that take commutativity into account.
1026 If we wanted to also support associative rules, we'd have to use a different
1027 strategy to avoid returning spurious 0, e.g. return ~(~0U >> 1) .
1028 MEMMODE indicates the mode of an enclosing MEM, and it's only
1029 used to compute autoinc values.
1030 We used to have a MODE argument for hashing for CONST_INTs, but that
1031 didn't make sense, since it caused spurious hash differences between
1032 (set (reg:SI 1) (const_int))
1033 (plus:SI (reg:SI 2) (reg:SI 1))
1035 (plus:SI (reg:SI 2) (const_int))
1036 If the mode is important in any context, it must be checked specifically
1037 in a comparison anyway, since relying on hash differences is unsafe. */
1040 cselib_hash_rtx (rtx x
, int create
, enum machine_mode memmode
)
1046 unsigned int hash
= 0;
1048 code
= GET_CODE (x
);
1049 hash
+= (unsigned) code
+ (unsigned) GET_MODE (x
);
1054 e
= CSELIB_VAL_PTR (x
);
1059 e
= cselib_lookup (x
, GET_MODE (x
), create
, memmode
);
1066 hash
+= ((unsigned) DEBUG_EXPR
<< 7)
1067 + DEBUG_TEMP_UID (DEBUG_EXPR_TREE_DECL (x
));
1068 return hash
? hash
: (unsigned int) DEBUG_EXPR
;
1070 case DEBUG_IMPLICIT_PTR
:
1071 hash
+= ((unsigned) DEBUG_IMPLICIT_PTR
<< 7)
1072 + DECL_UID (DEBUG_IMPLICIT_PTR_DECL (x
));
1073 return hash
? hash
: (unsigned int) DEBUG_IMPLICIT_PTR
;
1075 case DEBUG_PARAMETER_REF
:
1076 hash
+= ((unsigned) DEBUG_PARAMETER_REF
<< 7)
1077 + DECL_UID (DEBUG_PARAMETER_REF_DECL (x
));
1078 return hash
? hash
: (unsigned int) DEBUG_PARAMETER_REF
;
1081 /* ENTRY_VALUEs are function invariant, thus try to avoid
1082 recursing on argument if ENTRY_VALUE is one of the
1083 forms emitted by expand_debug_expr, otherwise
1084 ENTRY_VALUE hash would depend on the current value
1085 in some register or memory. */
1086 if (REG_P (ENTRY_VALUE_EXP (x
)))
1087 hash
+= (unsigned int) REG
1088 + (unsigned int) GET_MODE (ENTRY_VALUE_EXP (x
))
1089 + (unsigned int) REGNO (ENTRY_VALUE_EXP (x
));
1090 else if (MEM_P (ENTRY_VALUE_EXP (x
))
1091 && REG_P (XEXP (ENTRY_VALUE_EXP (x
), 0)))
1092 hash
+= (unsigned int) MEM
1093 + (unsigned int) GET_MODE (XEXP (ENTRY_VALUE_EXP (x
), 0))
1094 + (unsigned int) REGNO (XEXP (ENTRY_VALUE_EXP (x
), 0));
1096 hash
+= cselib_hash_rtx (ENTRY_VALUE_EXP (x
), create
, memmode
);
1097 return hash
? hash
: (unsigned int) ENTRY_VALUE
;
1100 hash
+= ((unsigned) CONST_INT
<< 7) + INTVAL (x
);
1101 return hash
? hash
: (unsigned int) CONST_INT
;
1104 /* This is like the general case, except that it only counts
1105 the integers representing the constant. */
1106 hash
+= (unsigned) code
+ (unsigned) GET_MODE (x
);
1107 if (GET_MODE (x
) != VOIDmode
)
1108 hash
+= real_hash (CONST_DOUBLE_REAL_VALUE (x
));
1110 hash
+= ((unsigned) CONST_DOUBLE_LOW (x
)
1111 + (unsigned) CONST_DOUBLE_HIGH (x
));
1112 return hash
? hash
: (unsigned int) CONST_DOUBLE
;
1115 hash
+= (unsigned int) code
+ (unsigned int) GET_MODE (x
);
1116 hash
+= fixed_hash (CONST_FIXED_VALUE (x
));
1117 return hash
? hash
: (unsigned int) CONST_FIXED
;
1124 units
= CONST_VECTOR_NUNITS (x
);
1126 for (i
= 0; i
< units
; ++i
)
1128 elt
= CONST_VECTOR_ELT (x
, i
);
1129 hash
+= cselib_hash_rtx (elt
, 0, memmode
);
1135 /* Assume there is only one rtx object for any given label. */
1137 /* We don't hash on the address of the CODE_LABEL to avoid bootstrap
1138 differences and differences between each stage's debugging dumps. */
1139 hash
+= (((unsigned int) LABEL_REF
<< 7)
1140 + CODE_LABEL_NUMBER (XEXP (x
, 0)));
1141 return hash
? hash
: (unsigned int) LABEL_REF
;
1145 /* Don't hash on the symbol's address to avoid bootstrap differences.
1146 Different hash values may cause expressions to be recorded in
1147 different orders and thus different registers to be used in the
1148 final assembler. This also avoids differences in the dump files
1149 between various stages. */
1151 const unsigned char *p
= (const unsigned char *) XSTR (x
, 0);
1154 h
+= (h
<< 7) + *p
++; /* ??? revisit */
1156 hash
+= ((unsigned int) SYMBOL_REF
<< 7) + h
;
1157 return hash
? hash
: (unsigned int) SYMBOL_REF
;
1162 /* We can't compute these without knowing the MEM mode. */
1163 gcc_assert (memmode
!= VOIDmode
);
1164 i
= GET_MODE_SIZE (memmode
);
1165 if (code
== PRE_DEC
)
1167 /* Adjust the hash so that (mem:MEMMODE (pre_* (reg))) hashes
1168 like (mem:MEMMODE (plus (reg) (const_int I))). */
1169 hash
+= (unsigned) PLUS
- (unsigned)code
1170 + cselib_hash_rtx (XEXP (x
, 0), create
, memmode
)
1171 + cselib_hash_rtx (GEN_INT (i
), create
, memmode
);
1172 return hash
? hash
: 1 + (unsigned) PLUS
;
1175 gcc_assert (memmode
!= VOIDmode
);
1176 return cselib_hash_rtx (XEXP (x
, 1), create
, memmode
);
1181 gcc_assert (memmode
!= VOIDmode
);
1182 return cselib_hash_rtx (XEXP (x
, 0), create
, memmode
);
1187 case UNSPEC_VOLATILE
:
1191 if (MEM_VOLATILE_P (x
))
1200 i
= GET_RTX_LENGTH (code
) - 1;
1201 fmt
= GET_RTX_FORMAT (code
);
1208 rtx tem
= XEXP (x
, i
);
1209 unsigned int tem_hash
= cselib_hash_rtx (tem
, create
, memmode
);
1218 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
1220 unsigned int tem_hash
1221 = cselib_hash_rtx (XVECEXP (x
, i
, j
), create
, memmode
);
1232 const unsigned char *p
= (const unsigned char *) XSTR (x
, i
);
1241 hash
+= XINT (x
, i
);
1254 return hash
? hash
: 1 + (unsigned int) GET_CODE (x
);
1257 /* Create a new value structure for VALUE and initialize it. The mode of the
1260 static inline cselib_val
*
1261 new_cselib_val (unsigned int hash
, enum machine_mode mode
, rtx x
)
1263 cselib_val
*e
= (cselib_val
*) pool_alloc (cselib_val_pool
);
1266 gcc_assert (next_uid
);
1269 e
->uid
= next_uid
++;
1270 /* We use an alloc pool to allocate this RTL construct because it
1271 accounts for about 8% of the overall memory usage. We know
1272 precisely when we can have VALUE RTXen (when cselib is active)
1273 so we don't need to put them in garbage collected memory.
1274 ??? Why should a VALUE be an RTX in the first place? */
1275 e
->val_rtx
= (rtx
) pool_alloc (value_pool
);
1276 memset (e
->val_rtx
, 0, RTX_HDR_SIZE
);
1277 PUT_CODE (e
->val_rtx
, VALUE
);
1278 PUT_MODE (e
->val_rtx
, mode
);
1279 CSELIB_VAL_PTR (e
->val_rtx
) = e
;
1282 e
->next_containing_mem
= 0;
1284 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1286 fprintf (dump_file
, "cselib value %u:%u ", e
->uid
, hash
);
1287 if (flag_dump_noaddr
|| flag_dump_unnumbered
)
1288 fputs ("# ", dump_file
);
1290 fprintf (dump_file
, "%p ", (void*)e
);
1291 print_rtl_single (dump_file
, x
);
1292 fputc ('\n', dump_file
);
1298 /* ADDR_ELT is a value that is used as address. MEM_ELT is the value that
1299 contains the data at this address. X is a MEM that represents the
1300 value. Update the two value structures to represent this situation. */
1303 add_mem_for_addr (cselib_val
*addr_elt
, cselib_val
*mem_elt
, rtx x
)
1305 struct elt_loc_list
*l
;
1307 addr_elt
= canonical_cselib_val (addr_elt
);
1308 mem_elt
= canonical_cselib_val (mem_elt
);
1310 /* Avoid duplicates. */
1311 for (l
= mem_elt
->locs
; l
; l
= l
->next
)
1313 && CSELIB_VAL_PTR (XEXP (l
->loc
, 0)) == addr_elt
)
1315 promote_debug_loc (l
);
1319 addr_elt
->addr_list
= new_elt_list (addr_elt
->addr_list
, mem_elt
);
1320 new_elt_loc_list (mem_elt
,
1321 replace_equiv_address_nv (x
, addr_elt
->val_rtx
));
1322 if (mem_elt
->next_containing_mem
== NULL
)
1324 mem_elt
->next_containing_mem
= first_containing_mem
;
1325 first_containing_mem
= mem_elt
;
1329 /* Subroutine of cselib_lookup. Return a value for X, which is a MEM rtx.
1330 If CREATE, make a new one if we haven't seen it before. */
1333 cselib_lookup_mem (rtx x
, int create
)
1335 enum machine_mode mode
= GET_MODE (x
);
1336 enum machine_mode addr_mode
;
1339 cselib_val
*mem_elt
;
1342 if (MEM_VOLATILE_P (x
) || mode
== BLKmode
1343 || !cselib_record_memory
1344 || (FLOAT_MODE_P (mode
) && flag_float_store
))
1347 addr_mode
= GET_MODE (XEXP (x
, 0));
1348 if (addr_mode
== VOIDmode
)
1351 /* Look up the value for the address. */
1352 addr
= cselib_lookup (XEXP (x
, 0), addr_mode
, create
, mode
);
1356 addr
= canonical_cselib_val (addr
);
1357 /* Find a value that describes a value of our mode at that address. */
1358 for (l
= addr
->addr_list
; l
; l
= l
->next
)
1359 if (GET_MODE (l
->elt
->val_rtx
) == mode
)
1361 promote_debug_loc (l
->elt
->locs
);
1368 mem_elt
= new_cselib_val (next_uid
, mode
, x
);
1369 add_mem_for_addr (addr
, mem_elt
, x
);
1370 slot
= cselib_find_slot (wrap_constant (mode
, x
), mem_elt
->hash
,
1376 /* Search through the possible substitutions in P. We prefer a non reg
1377 substitution because this allows us to expand the tree further. If
1378 we find, just a reg, take the lowest regno. There may be several
1379 non-reg results, we just take the first one because they will all
1380 expand to the same place. */
1383 expand_loc (struct elt_loc_list
*p
, struct expand_value_data
*evd
,
1386 rtx reg_result
= NULL
;
1387 unsigned int regno
= UINT_MAX
;
1388 struct elt_loc_list
*p_in
= p
;
1390 for (; p
; p
= p
->next
)
1392 /* Return these right away to avoid returning stack pointer based
1393 expressions for frame pointer and vice versa, which is something
1394 that would confuse DSE. See the comment in cselib_expand_value_rtx_1
1395 for more details. */
1397 && (REGNO (p
->loc
) == STACK_POINTER_REGNUM
1398 || REGNO (p
->loc
) == FRAME_POINTER_REGNUM
1399 || REGNO (p
->loc
) == HARD_FRAME_POINTER_REGNUM
1400 || REGNO (p
->loc
) == cfa_base_preserved_regno
))
1402 /* Avoid infinite recursion trying to expand a reg into a
1404 if ((REG_P (p
->loc
))
1405 && (REGNO (p
->loc
) < regno
)
1406 && !bitmap_bit_p (evd
->regs_active
, REGNO (p
->loc
)))
1408 reg_result
= p
->loc
;
1409 regno
= REGNO (p
->loc
);
1411 /* Avoid infinite recursion and do not try to expand the
1413 else if (GET_CODE (p
->loc
) == VALUE
1414 && CSELIB_VAL_PTR (p
->loc
)->locs
== p_in
)
1416 else if (!REG_P (p
->loc
))
1419 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1421 print_inline_rtx (dump_file
, p
->loc
, 0);
1422 fprintf (dump_file
, "\n");
1424 if (GET_CODE (p
->loc
) == LO_SUM
1425 && GET_CODE (XEXP (p
->loc
, 1)) == SYMBOL_REF
1427 && (note
= find_reg_note (p
->setting_insn
, REG_EQUAL
, NULL_RTX
))
1428 && XEXP (note
, 0) == XEXP (p
->loc
, 1))
1429 return XEXP (p
->loc
, 1);
1430 result
= cselib_expand_value_rtx_1 (p
->loc
, evd
, max_depth
- 1);
1437 if (regno
!= UINT_MAX
)
1440 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1441 fprintf (dump_file
, "r%d\n", regno
);
1443 result
= cselib_expand_value_rtx_1 (reg_result
, evd
, max_depth
- 1);
1448 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1452 print_inline_rtx (dump_file
, reg_result
, 0);
1453 fprintf (dump_file
, "\n");
1456 fprintf (dump_file
, "NULL\n");
1462 /* Forward substitute and expand an expression out to its roots.
1463 This is the opposite of common subexpression. Because local value
1464 numbering is such a weak optimization, the expanded expression is
1465 pretty much unique (not from a pointer equals point of view but
1466 from a tree shape point of view.
1468 This function returns NULL if the expansion fails. The expansion
1469 will fail if there is no value number for one of the operands or if
1470 one of the operands has been overwritten between the current insn
1471 and the beginning of the basic block. For instance x has no
1477 REGS_ACTIVE is a scratch bitmap that should be clear when passing in.
1478 It is clear on return. */
1481 cselib_expand_value_rtx (rtx orig
, bitmap regs_active
, int max_depth
)
1483 struct expand_value_data evd
;
1485 evd
.regs_active
= regs_active
;
1486 evd
.callback
= NULL
;
1487 evd
.callback_arg
= NULL
;
1490 return cselib_expand_value_rtx_1 (orig
, &evd
, max_depth
);
1493 /* Same as cselib_expand_value_rtx, but using a callback to try to
1494 resolve some expressions. The CB function should return ORIG if it
1495 can't or does not want to deal with a certain RTX. Any other
1496 return value, including NULL, will be used as the expansion for
1497 VALUE, without any further changes. */
1500 cselib_expand_value_rtx_cb (rtx orig
, bitmap regs_active
, int max_depth
,
1501 cselib_expand_callback cb
, void *data
)
1503 struct expand_value_data evd
;
1505 evd
.regs_active
= regs_active
;
1507 evd
.callback_arg
= data
;
1510 return cselib_expand_value_rtx_1 (orig
, &evd
, max_depth
);
1513 /* Similar to cselib_expand_value_rtx_cb, but no rtxs are actually copied
1514 or simplified. Useful to find out whether cselib_expand_value_rtx_cb
1515 would return NULL or non-NULL, without allocating new rtx. */
1518 cselib_dummy_expand_value_rtx_cb (rtx orig
, bitmap regs_active
, int max_depth
,
1519 cselib_expand_callback cb
, void *data
)
1521 struct expand_value_data evd
;
1523 evd
.regs_active
= regs_active
;
1525 evd
.callback_arg
= data
;
1528 return cselib_expand_value_rtx_1 (orig
, &evd
, max_depth
) != NULL
;
1531 /* Internal implementation of cselib_expand_value_rtx and
1532 cselib_expand_value_rtx_cb. */
1535 cselib_expand_value_rtx_1 (rtx orig
, struct expand_value_data
*evd
,
1541 const char *format_ptr
;
1542 enum machine_mode mode
;
1544 code
= GET_CODE (orig
);
1546 /* For the context of dse, if we end up expand into a huge tree, we
1547 will not have a useful address, so we might as well just give up
1556 struct elt_list
*l
= REG_VALUES (REGNO (orig
));
1558 if (l
&& l
->elt
== NULL
)
1560 for (; l
; l
= l
->next
)
1561 if (GET_MODE (l
->elt
->val_rtx
) == GET_MODE (orig
))
1564 unsigned regno
= REGNO (orig
);
1566 /* The only thing that we are not willing to do (this
1567 is requirement of dse and if others potential uses
1568 need this function we should add a parm to control
1569 it) is that we will not substitute the
1570 STACK_POINTER_REGNUM, FRAME_POINTER or the
1573 These expansions confuses the code that notices that
1574 stores into the frame go dead at the end of the
1575 function and that the frame is not effected by calls
1576 to subroutines. If you allow the
1577 STACK_POINTER_REGNUM substitution, then dse will
1578 think that parameter pushing also goes dead which is
1579 wrong. If you allow the FRAME_POINTER or the
1580 HARD_FRAME_POINTER then you lose the opportunity to
1581 make the frame assumptions. */
1582 if (regno
== STACK_POINTER_REGNUM
1583 || regno
== FRAME_POINTER_REGNUM
1584 || regno
== HARD_FRAME_POINTER_REGNUM
1585 || regno
== cfa_base_preserved_regno
)
1588 bitmap_set_bit (evd
->regs_active
, regno
);
1590 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1591 fprintf (dump_file
, "expanding: r%d into: ", regno
);
1593 result
= expand_loc (l
->elt
->locs
, evd
, max_depth
);
1594 bitmap_clear_bit (evd
->regs_active
, regno
);
1611 /* SCRATCH must be shared because they represent distinct values. */
1614 if (REG_P (XEXP (orig
, 0)) && HARD_REGISTER_NUM_P (REGNO (XEXP (orig
, 0))))
1619 if (shared_const_p (orig
))
1629 subreg
= evd
->callback (orig
, evd
->regs_active
, max_depth
,
1635 subreg
= cselib_expand_value_rtx_1 (SUBREG_REG (orig
), evd
,
1639 scopy
= simplify_gen_subreg (GET_MODE (orig
), subreg
,
1640 GET_MODE (SUBREG_REG (orig
)),
1641 SUBREG_BYTE (orig
));
1643 || (GET_CODE (scopy
) == SUBREG
1644 && !REG_P (SUBREG_REG (scopy
))
1645 && !MEM_P (SUBREG_REG (scopy
))))
1655 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1657 fputs ("\nexpanding ", dump_file
);
1658 print_rtl_single (dump_file
, orig
);
1659 fputs (" into...", dump_file
);
1664 result
= evd
->callback (orig
, evd
->regs_active
, max_depth
,
1671 result
= expand_loc (CSELIB_VAL_PTR (orig
)->locs
, evd
, max_depth
);
1677 return evd
->callback (orig
, evd
->regs_active
, max_depth
,
1685 /* Copy the various flags, fields, and other information. We assume
1686 that all fields need copying, and then clear the fields that should
1687 not be copied. That is the sensible default behavior, and forces
1688 us to explicitly document why we are *not* copying a flag. */
1692 copy
= shallow_copy_rtx (orig
);
1694 format_ptr
= GET_RTX_FORMAT (code
);
1696 for (i
= 0; i
< GET_RTX_LENGTH (code
); i
++)
1697 switch (*format_ptr
++)
1700 if (XEXP (orig
, i
) != NULL
)
1702 rtx result
= cselib_expand_value_rtx_1 (XEXP (orig
, i
), evd
,
1707 XEXP (copy
, i
) = result
;
1713 if (XVEC (orig
, i
) != NULL
)
1716 XVEC (copy
, i
) = rtvec_alloc (XVECLEN (orig
, i
));
1717 for (j
= 0; j
< XVECLEN (orig
, i
); j
++)
1719 rtx result
= cselib_expand_value_rtx_1 (XVECEXP (orig
, i
, j
),
1720 evd
, max_depth
- 1);
1724 XVECEXP (copy
, i
, j
) = result
;
1738 /* These are left unchanged. */
1748 mode
= GET_MODE (copy
);
1749 /* If an operand has been simplified into CONST_INT, which doesn't
1750 have a mode and the mode isn't derivable from whole rtx's mode,
1751 try simplify_*_operation first with mode from original's operand
1752 and as a fallback wrap CONST_INT into gen_rtx_CONST. */
1754 switch (GET_RTX_CLASS (code
))
1757 if (CONST_INT_P (XEXP (copy
, 0))
1758 && GET_MODE (XEXP (orig
, 0)) != VOIDmode
)
1760 scopy
= simplify_unary_operation (code
, mode
, XEXP (copy
, 0),
1761 GET_MODE (XEXP (orig
, 0)));
1766 case RTX_COMM_ARITH
:
1768 /* These expressions can derive operand modes from the whole rtx's mode. */
1771 case RTX_BITFIELD_OPS
:
1772 if (CONST_INT_P (XEXP (copy
, 0))
1773 && GET_MODE (XEXP (orig
, 0)) != VOIDmode
)
1775 scopy
= simplify_ternary_operation (code
, mode
,
1776 GET_MODE (XEXP (orig
, 0)),
1777 XEXP (copy
, 0), XEXP (copy
, 1),
1784 case RTX_COMM_COMPARE
:
1785 if (CONST_INT_P (XEXP (copy
, 0))
1786 && GET_MODE (XEXP (copy
, 1)) == VOIDmode
1787 && (GET_MODE (XEXP (orig
, 0)) != VOIDmode
1788 || GET_MODE (XEXP (orig
, 1)) != VOIDmode
))
1790 scopy
= simplify_relational_operation (code
, mode
,
1791 (GET_MODE (XEXP (orig
, 0))
1793 ? GET_MODE (XEXP (orig
, 0))
1794 : GET_MODE (XEXP (orig
, 1)),
1804 scopy
= simplify_rtx (copy
);
1810 /* Walk rtx X and replace all occurrences of REG and MEM subexpressions
1811 with VALUE expressions. This way, it becomes independent of changes
1812 to registers and memory.
1813 X isn't actually modified; if modifications are needed, new rtl is
1814 allocated. However, the return value can share rtl with X.
1815 If X is within a MEM, MEMMODE must be the mode of the MEM. */
1818 cselib_subst_to_values (rtx x
, enum machine_mode memmode
)
1820 enum rtx_code code
= GET_CODE (x
);
1821 const char *fmt
= GET_RTX_FORMAT (code
);
1830 l
= REG_VALUES (REGNO (x
));
1831 if (l
&& l
->elt
== NULL
)
1833 for (; l
; l
= l
->next
)
1834 if (GET_MODE (l
->elt
->val_rtx
) == GET_MODE (x
))
1835 return l
->elt
->val_rtx
;
1840 e
= cselib_lookup_mem (x
, 0);
1841 /* This used to happen for autoincrements, but we deal with them
1842 properly now. Remove the if stmt for the next release. */
1845 /* Assign a value that doesn't match any other. */
1846 e
= new_cselib_val (next_uid
, GET_MODE (x
), x
);
1851 e
= cselib_lookup (x
, GET_MODE (x
), 0, memmode
);
1864 gcc_assert (memmode
!= VOIDmode
);
1865 i
= GET_MODE_SIZE (memmode
);
1866 if (code
== PRE_DEC
)
1868 return cselib_subst_to_values (plus_constant (GET_MODE (x
),
1873 gcc_assert (memmode
!= VOIDmode
);
1874 return cselib_subst_to_values (XEXP (x
, 1), memmode
);
1879 gcc_assert (memmode
!= VOIDmode
);
1880 return cselib_subst_to_values (XEXP (x
, 0), memmode
);
1886 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
1890 rtx t
= cselib_subst_to_values (XEXP (x
, i
), memmode
);
1892 if (t
!= XEXP (x
, i
))
1895 copy
= shallow_copy_rtx (x
);
1899 else if (fmt
[i
] == 'E')
1903 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
1905 rtx t
= cselib_subst_to_values (XVECEXP (x
, i
, j
), memmode
);
1907 if (t
!= XVECEXP (x
, i
, j
))
1909 if (XVEC (x
, i
) == XVEC (copy
, i
))
1912 copy
= shallow_copy_rtx (x
);
1913 XVEC (copy
, i
) = shallow_copy_rtvec (XVEC (x
, i
));
1915 XVECEXP (copy
, i
, j
) = t
;
1924 /* Wrapper for cselib_subst_to_values, that indicates X is in INSN. */
1927 cselib_subst_to_values_from_insn (rtx x
, enum machine_mode memmode
, rtx insn
)
1930 gcc_assert (!cselib_current_insn
);
1931 cselib_current_insn
= insn
;
1932 ret
= cselib_subst_to_values (x
, memmode
);
1933 cselib_current_insn
= NULL
;
1937 /* Look up the rtl expression X in our tables and return the value it
1938 has. If CREATE is zero, we return NULL if we don't know the value.
1939 Otherwise, we create a new one if possible, using mode MODE if X
1940 doesn't have a mode (i.e. because it's a constant). When X is part
1941 of an address, MEMMODE should be the mode of the enclosing MEM if
1942 we're tracking autoinc expressions. */
1945 cselib_lookup_1 (rtx x
, enum machine_mode mode
,
1946 int create
, enum machine_mode memmode
)
1950 unsigned int hashval
;
1952 if (GET_MODE (x
) != VOIDmode
)
1953 mode
= GET_MODE (x
);
1955 if (GET_CODE (x
) == VALUE
)
1956 return CSELIB_VAL_PTR (x
);
1961 unsigned int i
= REGNO (x
);
1964 if (l
&& l
->elt
== NULL
)
1966 for (; l
; l
= l
->next
)
1967 if (mode
== GET_MODE (l
->elt
->val_rtx
))
1969 promote_debug_loc (l
->elt
->locs
);
1976 if (i
< FIRST_PSEUDO_REGISTER
)
1978 unsigned int n
= hard_regno_nregs
[i
][mode
];
1980 if (n
> max_value_regs
)
1984 e
= new_cselib_val (next_uid
, GET_MODE (x
), x
);
1985 new_elt_loc_list (e
, x
);
1986 if (REG_VALUES (i
) == 0)
1988 /* Maintain the invariant that the first entry of
1989 REG_VALUES, if present, must be the value used to set the
1990 register, or NULL. */
1991 used_regs
[n_used_regs
++] = i
;
1992 REG_VALUES (i
) = new_elt_list (REG_VALUES (i
), NULL
);
1994 else if (cselib_preserve_constants
1995 && GET_MODE_CLASS (mode
) == MODE_INT
)
1997 /* During var-tracking, try harder to find equivalences
1998 for SUBREGs. If a setter sets say a DImode register
1999 and user uses that register only in SImode, add a lowpart
2001 struct elt_list
*lwider
= NULL
;
2003 if (l
&& l
->elt
== NULL
)
2005 for (; l
; l
= l
->next
)
2006 if (GET_MODE_CLASS (GET_MODE (l
->elt
->val_rtx
)) == MODE_INT
2007 && GET_MODE_SIZE (GET_MODE (l
->elt
->val_rtx
))
2008 > GET_MODE_SIZE (mode
)
2010 || GET_MODE_SIZE (GET_MODE (l
->elt
->val_rtx
))
2011 < GET_MODE_SIZE (GET_MODE (lwider
->elt
->val_rtx
))))
2013 struct elt_loc_list
*el
;
2014 if (i
< FIRST_PSEUDO_REGISTER
2015 && hard_regno_nregs
[i
][GET_MODE (l
->elt
->val_rtx
)] != 1)
2017 for (el
= l
->elt
->locs
; el
; el
= el
->next
)
2018 if (!REG_P (el
->loc
))
2025 rtx sub
= lowpart_subreg (mode
, lwider
->elt
->val_rtx
,
2026 GET_MODE (lwider
->elt
->val_rtx
));
2028 new_elt_loc_list (e
, sub
);
2031 REG_VALUES (i
)->next
= new_elt_list (REG_VALUES (i
)->next
, e
);
2032 slot
= cselib_find_slot (x
, e
->hash
, INSERT
, memmode
);
2038 return cselib_lookup_mem (x
, create
);
2040 hashval
= cselib_hash_rtx (x
, create
, memmode
);
2041 /* Can't even create if hashing is not possible. */
2045 slot
= cselib_find_slot (wrap_constant (mode
, x
), hashval
,
2046 create
? INSERT
: NO_INSERT
, memmode
);
2050 e
= (cselib_val
*) *slot
;
2054 e
= new_cselib_val (hashval
, mode
, x
);
2056 /* We have to fill the slot before calling cselib_subst_to_values:
2057 the hash table is inconsistent until we do so, and
2058 cselib_subst_to_values will need to do lookups. */
2060 new_elt_loc_list (e
, cselib_subst_to_values (x
, memmode
));
2064 /* Wrapper for cselib_lookup, that indicates X is in INSN. */
2067 cselib_lookup_from_insn (rtx x
, enum machine_mode mode
,
2068 int create
, enum machine_mode memmode
, rtx insn
)
2072 gcc_assert (!cselib_current_insn
);
2073 cselib_current_insn
= insn
;
2075 ret
= cselib_lookup (x
, mode
, create
, memmode
);
2077 cselib_current_insn
= NULL
;
2082 /* Wrapper for cselib_lookup_1, that logs the lookup result and
2083 maintains invariants related with debug insns. */
2086 cselib_lookup (rtx x
, enum machine_mode mode
,
2087 int create
, enum machine_mode memmode
)
2089 cselib_val
*ret
= cselib_lookup_1 (x
, mode
, create
, memmode
);
2091 /* ??? Should we return NULL if we're not to create an entry, the
2092 found loc is a debug loc and cselib_current_insn is not DEBUG?
2093 If so, we should also avoid converting val to non-DEBUG; probably
2094 easiest setting cselib_current_insn to NULL before the call
2097 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
2099 fputs ("cselib lookup ", dump_file
);
2100 print_inline_rtx (dump_file
, x
, 2);
2101 fprintf (dump_file
, " => %u:%u\n",
2103 ret
? ret
->hash
: 0);
2109 /* Invalidate any entries in reg_values that overlap REGNO. This is called
2110 if REGNO is changing. MODE is the mode of the assignment to REGNO, which
2111 is used to determine how many hard registers are being changed. If MODE
2112 is VOIDmode, then only REGNO is being changed; this is used when
2113 invalidating call clobbered registers across a call. */
2116 cselib_invalidate_regno (unsigned int regno
, enum machine_mode mode
)
2118 unsigned int endregno
;
2121 /* If we see pseudos after reload, something is _wrong_. */
2122 gcc_assert (!reload_completed
|| regno
< FIRST_PSEUDO_REGISTER
2123 || reg_renumber
[regno
] < 0);
2125 /* Determine the range of registers that must be invalidated. For
2126 pseudos, only REGNO is affected. For hard regs, we must take MODE
2127 into account, and we must also invalidate lower register numbers
2128 if they contain values that overlap REGNO. */
2129 if (regno
< FIRST_PSEUDO_REGISTER
)
2131 gcc_assert (mode
!= VOIDmode
);
2133 if (regno
< max_value_regs
)
2136 i
= regno
- max_value_regs
;
2138 endregno
= end_hard_regno (mode
, regno
);
2143 endregno
= regno
+ 1;
2146 for (; i
< endregno
; i
++)
2148 struct elt_list
**l
= ®_VALUES (i
);
2150 /* Go through all known values for this reg; if it overlaps the range
2151 we're invalidating, remove the value. */
2154 cselib_val
*v
= (*l
)->elt
;
2157 struct elt_loc_list
**p
;
2158 unsigned int this_last
= i
;
2160 if (i
< FIRST_PSEUDO_REGISTER
&& v
!= NULL
)
2161 this_last
= end_hard_regno (GET_MODE (v
->val_rtx
), i
) - 1;
2163 if (this_last
< regno
|| v
== NULL
2164 || (v
== cfa_base_preserved_val
2165 && i
== cfa_base_preserved_regno
))
2171 /* We have an overlap. */
2172 if (*l
== REG_VALUES (i
))
2174 /* Maintain the invariant that the first entry of
2175 REG_VALUES, if present, must be the value used to set
2176 the register, or NULL. This is also nice because
2177 then we won't push the same regno onto user_regs
2183 unchain_one_elt_list (l
);
2185 v
= canonical_cselib_val (v
);
2187 had_locs
= v
->locs
!= NULL
;
2188 setting_insn
= v
->locs
? v
->locs
->setting_insn
: NULL
;
2190 /* Now, we clear the mapping from value to reg. It must exist, so
2191 this code will crash intentionally if it doesn't. */
2192 for (p
= &v
->locs
; ; p
= &(*p
)->next
)
2196 if (REG_P (x
) && REGNO (x
) == i
)
2198 unchain_one_elt_loc_list (p
);
2203 if (had_locs
&& v
->locs
== 0 && !PRESERVED_VALUE_P (v
->val_rtx
))
2205 if (setting_insn
&& DEBUG_INSN_P (setting_insn
))
2206 n_useless_debug_values
++;
2214 /* Invalidate any locations in the table which are changed because of a
2215 store to MEM_RTX. If this is called because of a non-const call
2216 instruction, MEM_RTX is (mem:BLK const0_rtx). */
2219 cselib_invalidate_mem (rtx mem_rtx
)
2221 cselib_val
**vp
, *v
, *next
;
2225 mem_addr
= canon_rtx (get_addr (XEXP (mem_rtx
, 0)));
2226 mem_rtx
= canon_rtx (mem_rtx
);
2228 vp
= &first_containing_mem
;
2229 for (v
= *vp
; v
!= &dummy_val
; v
= next
)
2231 bool has_mem
= false;
2232 struct elt_loc_list
**p
= &v
->locs
;
2233 bool had_locs
= v
->locs
!= NULL
;
2234 rtx setting_insn
= v
->locs
? v
->locs
->setting_insn
: NULL
;
2240 struct elt_list
**mem_chain
;
2242 /* MEMs may occur in locations only at the top level; below
2243 that every MEM or REG is substituted by its VALUE. */
2249 if (num_mems
< PARAM_VALUE (PARAM_MAX_CSELIB_MEMORY_LOCATIONS
)
2250 && ! canon_true_dependence (mem_rtx
, GET_MODE (mem_rtx
),
2251 mem_addr
, x
, NULL_RTX
))
2259 /* This one overlaps. */
2260 /* We must have a mapping from this MEM's address to the
2261 value (E). Remove that, too. */
2262 addr
= cselib_lookup (XEXP (x
, 0), VOIDmode
, 0, GET_MODE (x
));
2263 addr
= canonical_cselib_val (addr
);
2264 gcc_checking_assert (v
== canonical_cselib_val (v
));
2265 mem_chain
= &addr
->addr_list
;
2268 cselib_val
*canon
= canonical_cselib_val ((*mem_chain
)->elt
);
2272 unchain_one_elt_list (mem_chain
);
2276 /* Record canonicalized elt. */
2277 (*mem_chain
)->elt
= canon
;
2279 mem_chain
= &(*mem_chain
)->next
;
2282 unchain_one_elt_loc_list (p
);
2285 if (had_locs
&& v
->locs
== 0 && !PRESERVED_VALUE_P (v
->val_rtx
))
2287 if (setting_insn
&& DEBUG_INSN_P (setting_insn
))
2288 n_useless_debug_values
++;
2293 next
= v
->next_containing_mem
;
2297 vp
= &(*vp
)->next_containing_mem
;
2300 v
->next_containing_mem
= NULL
;
2305 /* Invalidate DEST, which is being assigned to or clobbered. */
2308 cselib_invalidate_rtx (rtx dest
)
2310 while (GET_CODE (dest
) == SUBREG
2311 || GET_CODE (dest
) == ZERO_EXTRACT
2312 || GET_CODE (dest
) == STRICT_LOW_PART
)
2313 dest
= XEXP (dest
, 0);
2316 cselib_invalidate_regno (REGNO (dest
), GET_MODE (dest
));
2317 else if (MEM_P (dest
))
2318 cselib_invalidate_mem (dest
);
2321 /* A wrapper for cselib_invalidate_rtx to be called via note_stores. */
2324 cselib_invalidate_rtx_note_stores (rtx dest
, const_rtx ignore ATTRIBUTE_UNUSED
,
2325 void *data ATTRIBUTE_UNUSED
)
2327 cselib_invalidate_rtx (dest
);
2330 /* Record the result of a SET instruction. DEST is being set; the source
2331 contains the value described by SRC_ELT. If DEST is a MEM, DEST_ADDR_ELT
2332 describes its address. */
2335 cselib_record_set (rtx dest
, cselib_val
*src_elt
, cselib_val
*dest_addr_elt
)
2337 int dreg
= REG_P (dest
) ? (int) REGNO (dest
) : -1;
2339 if (src_elt
== 0 || side_effects_p (dest
))
2344 if (dreg
< FIRST_PSEUDO_REGISTER
)
2346 unsigned int n
= hard_regno_nregs
[dreg
][GET_MODE (dest
)];
2348 if (n
> max_value_regs
)
2352 if (REG_VALUES (dreg
) == 0)
2354 used_regs
[n_used_regs
++] = dreg
;
2355 REG_VALUES (dreg
) = new_elt_list (REG_VALUES (dreg
), src_elt
);
2359 /* The register should have been invalidated. */
2360 gcc_assert (REG_VALUES (dreg
)->elt
== 0);
2361 REG_VALUES (dreg
)->elt
= src_elt
;
2364 if (src_elt
->locs
== 0 && !PRESERVED_VALUE_P (src_elt
->val_rtx
))
2366 new_elt_loc_list (src_elt
, dest
);
2368 else if (MEM_P (dest
) && dest_addr_elt
!= 0
2369 && cselib_record_memory
)
2371 if (src_elt
->locs
== 0 && !PRESERVED_VALUE_P (src_elt
->val_rtx
))
2373 add_mem_for_addr (dest_addr_elt
, src_elt
, dest
);
2377 /* Make ELT and X's VALUE equivalent to each other at INSN. */
2380 cselib_add_permanent_equiv (cselib_val
*elt
, rtx x
, rtx insn
)
2383 rtx save_cselib_current_insn
= cselib_current_insn
;
2385 gcc_checking_assert (elt
);
2386 gcc_checking_assert (PRESERVED_VALUE_P (elt
->val_rtx
));
2387 gcc_checking_assert (!side_effects_p (x
));
2389 cselib_current_insn
= insn
;
2391 nelt
= cselib_lookup (x
, GET_MODE (elt
->val_rtx
), 1, VOIDmode
);
2395 cselib_any_perm_equivs
= true;
2397 if (!PRESERVED_VALUE_P (nelt
->val_rtx
))
2398 cselib_preserve_value (nelt
);
2400 new_elt_loc_list (nelt
, elt
->val_rtx
);
2403 cselib_current_insn
= save_cselib_current_insn
;
2406 /* Return TRUE if any permanent equivalences have been recorded since
2407 the table was last initialized. */
2409 cselib_have_permanent_equivalences (void)
2411 return cselib_any_perm_equivs
;
2414 /* There is no good way to determine how many elements there can be
2415 in a PARALLEL. Since it's fairly cheap, use a really large number. */
2416 #define MAX_SETS (FIRST_PSEUDO_REGISTER * 2)
2418 struct cselib_record_autoinc_data
2420 struct cselib_set
*sets
;
2424 /* Callback for for_each_inc_dec. Records in ARG the SETs implied by
2425 autoinc RTXs: SRC plus SRCOFF if non-NULL is stored in DEST. */
2428 cselib_record_autoinc_cb (rtx mem ATTRIBUTE_UNUSED
, rtx op ATTRIBUTE_UNUSED
,
2429 rtx dest
, rtx src
, rtx srcoff
, void *arg
)
2431 struct cselib_record_autoinc_data
*data
;
2432 data
= (struct cselib_record_autoinc_data
*)arg
;
2434 data
->sets
[data
->n_sets
].dest
= dest
;
2437 data
->sets
[data
->n_sets
].src
= gen_rtx_PLUS (GET_MODE (src
), src
, srcoff
);
2439 data
->sets
[data
->n_sets
].src
= src
;
2446 /* Record the effects of any sets and autoincs in INSN. */
2448 cselib_record_sets (rtx insn
)
2452 struct cselib_set sets
[MAX_SETS
];
2453 rtx body
= PATTERN (insn
);
2455 int n_sets_before_autoinc
;
2456 struct cselib_record_autoinc_data data
;
2458 body
= PATTERN (insn
);
2459 if (GET_CODE (body
) == COND_EXEC
)
2461 cond
= COND_EXEC_TEST (body
);
2462 body
= COND_EXEC_CODE (body
);
2465 /* Find all sets. */
2466 if (GET_CODE (body
) == SET
)
2468 sets
[0].src
= SET_SRC (body
);
2469 sets
[0].dest
= SET_DEST (body
);
2472 else if (GET_CODE (body
) == PARALLEL
)
2474 /* Look through the PARALLEL and record the values being
2475 set, if possible. Also handle any CLOBBERs. */
2476 for (i
= XVECLEN (body
, 0) - 1; i
>= 0; --i
)
2478 rtx x
= XVECEXP (body
, 0, i
);
2480 if (GET_CODE (x
) == SET
)
2482 sets
[n_sets
].src
= SET_SRC (x
);
2483 sets
[n_sets
].dest
= SET_DEST (x
);
2490 && MEM_P (sets
[0].src
)
2491 && !cselib_record_memory
2492 && MEM_READONLY_P (sets
[0].src
))
2494 rtx note
= find_reg_equal_equiv_note (insn
);
2496 if (note
&& CONSTANT_P (XEXP (note
, 0)))
2497 sets
[0].src
= XEXP (note
, 0);
2501 data
.n_sets
= n_sets_before_autoinc
= n_sets
;
2502 for_each_inc_dec (&insn
, cselib_record_autoinc_cb
, &data
);
2503 n_sets
= data
.n_sets
;
2505 /* Look up the values that are read. Do this before invalidating the
2506 locations that are written. */
2507 for (i
= 0; i
< n_sets
; i
++)
2509 rtx dest
= sets
[i
].dest
;
2511 /* A STRICT_LOW_PART can be ignored; we'll record the equivalence for
2512 the low part after invalidating any knowledge about larger modes. */
2513 if (GET_CODE (sets
[i
].dest
) == STRICT_LOW_PART
)
2514 sets
[i
].dest
= dest
= XEXP (dest
, 0);
2516 /* We don't know how to record anything but REG or MEM. */
2518 || (MEM_P (dest
) && cselib_record_memory
))
2520 rtx src
= sets
[i
].src
;
2522 src
= gen_rtx_IF_THEN_ELSE (GET_MODE (dest
), cond
, src
, dest
);
2523 sets
[i
].src_elt
= cselib_lookup (src
, GET_MODE (dest
), 1, VOIDmode
);
2526 enum machine_mode address_mode
= get_address_mode (dest
);
2528 sets
[i
].dest_addr_elt
= cselib_lookup (XEXP (dest
, 0),
2533 sets
[i
].dest_addr_elt
= 0;
2537 if (cselib_record_sets_hook
)
2538 cselib_record_sets_hook (insn
, sets
, n_sets
);
2540 /* Invalidate all locations written by this insn. Note that the elts we
2541 looked up in the previous loop aren't affected, just some of their
2542 locations may go away. */
2543 note_stores (body
, cselib_invalidate_rtx_note_stores
, NULL
);
2545 for (i
= n_sets_before_autoinc
; i
< n_sets
; i
++)
2546 cselib_invalidate_rtx (sets
[i
].dest
);
2548 /* If this is an asm, look for duplicate sets. This can happen when the
2549 user uses the same value as an output multiple times. This is valid
2550 if the outputs are not actually used thereafter. Treat this case as
2551 if the value isn't actually set. We do this by smashing the destination
2552 to pc_rtx, so that we won't record the value later. */
2553 if (n_sets
>= 2 && asm_noperands (body
) >= 0)
2555 for (i
= 0; i
< n_sets
; i
++)
2557 rtx dest
= sets
[i
].dest
;
2558 if (REG_P (dest
) || MEM_P (dest
))
2561 for (j
= i
+ 1; j
< n_sets
; j
++)
2562 if (rtx_equal_p (dest
, sets
[j
].dest
))
2564 sets
[i
].dest
= pc_rtx
;
2565 sets
[j
].dest
= pc_rtx
;
2571 /* Now enter the equivalences in our tables. */
2572 for (i
= 0; i
< n_sets
; i
++)
2574 rtx dest
= sets
[i
].dest
;
2576 || (MEM_P (dest
) && cselib_record_memory
))
2577 cselib_record_set (dest
, sets
[i
].src_elt
, sets
[i
].dest_addr_elt
);
2581 /* Record the effects of INSN. */
2584 cselib_process_insn (rtx insn
)
2589 cselib_current_insn
= insn
;
2591 /* Forget everything at a CODE_LABEL, a volatile asm, or a setjmp. */
2594 && find_reg_note (insn
, REG_SETJMP
, NULL
))
2595 || (NONJUMP_INSN_P (insn
)
2596 && GET_CODE (PATTERN (insn
)) == ASM_OPERANDS
2597 && MEM_VOLATILE_P (PATTERN (insn
))))
2599 cselib_reset_table (next_uid
);
2600 cselib_current_insn
= NULL_RTX
;
2604 if (! INSN_P (insn
))
2606 cselib_current_insn
= NULL_RTX
;
2610 /* If this is a call instruction, forget anything stored in a
2611 call clobbered register, or, if this is not a const call, in
2615 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; i
++)
2616 if (call_used_regs
[i
]
2617 || (REG_VALUES (i
) && REG_VALUES (i
)->elt
2618 && HARD_REGNO_CALL_PART_CLOBBERED (i
,
2619 GET_MODE (REG_VALUES (i
)->elt
->val_rtx
))))
2620 cselib_invalidate_regno (i
, reg_raw_mode
[i
]);
2622 /* Since it is not clear how cselib is going to be used, be
2623 conservative here and treat looping pure or const functions
2624 as if they were regular functions. */
2625 if (RTL_LOOPING_CONST_OR_PURE_CALL_P (insn
)
2626 || !(RTL_CONST_OR_PURE_CALL_P (insn
)))
2627 cselib_invalidate_mem (callmem
);
2630 cselib_record_sets (insn
);
2632 /* Look for any CLOBBERs in CALL_INSN_FUNCTION_USAGE, but only
2633 after we have processed the insn. */
2635 for (x
= CALL_INSN_FUNCTION_USAGE (insn
); x
; x
= XEXP (x
, 1))
2636 if (GET_CODE (XEXP (x
, 0)) == CLOBBER
)
2637 cselib_invalidate_rtx (XEXP (XEXP (x
, 0), 0));
2639 cselib_current_insn
= NULL_RTX
;
2641 if (n_useless_values
> MAX_USELESS_VALUES
2642 /* remove_useless_values is linear in the hash table size. Avoid
2643 quadratic behavior for very large hashtables with very few
2644 useless elements. */
2645 && ((unsigned int)n_useless_values
2646 > (cselib_hash_table
->n_elements
2647 - cselib_hash_table
->n_deleted
2648 - n_debug_values
) / 4))
2649 remove_useless_values ();
2652 /* Initialize cselib for one pass. The caller must also call
2653 init_alias_analysis. */
2656 cselib_init (int record_what
)
2658 elt_list_pool
= create_alloc_pool ("elt_list",
2659 sizeof (struct elt_list
), 10);
2660 elt_loc_list_pool
= create_alloc_pool ("elt_loc_list",
2661 sizeof (struct elt_loc_list
), 10);
2662 cselib_val_pool
= create_alloc_pool ("cselib_val_list",
2663 sizeof (cselib_val
), 10);
2664 value_pool
= create_alloc_pool ("value", RTX_CODE_SIZE (VALUE
), 100);
2665 cselib_record_memory
= record_what
& CSELIB_RECORD_MEMORY
;
2666 cselib_preserve_constants
= record_what
& CSELIB_PRESERVE_CONSTANTS
;
2667 cselib_any_perm_equivs
= false;
2669 /* (mem:BLK (scratch)) is a special mechanism to conflict with everything,
2670 see canon_true_dependence. This is only created once. */
2672 callmem
= gen_rtx_MEM (BLKmode
, gen_rtx_SCRATCH (VOIDmode
));
2674 cselib_nregs
= max_reg_num ();
2676 /* We preserve reg_values to allow expensive clearing of the whole thing.
2677 Reallocate it however if it happens to be too large. */
2678 if (!reg_values
|| reg_values_size
< cselib_nregs
2679 || (reg_values_size
> 10 && reg_values_size
> cselib_nregs
* 4))
2682 /* Some space for newly emit instructions so we don't end up
2683 reallocating in between passes. */
2684 reg_values_size
= cselib_nregs
+ (63 + cselib_nregs
) / 16;
2685 reg_values
= XCNEWVEC (struct elt_list
*, reg_values_size
);
2687 used_regs
= XNEWVEC (unsigned int, cselib_nregs
);
2689 cselib_hash_table
= htab_create (31, get_value_hash
,
2690 entry_and_rtx_equal_p
, NULL
);
2694 /* Called when the current user is done with cselib. */
2697 cselib_finish (void)
2699 cselib_discard_hook
= NULL
;
2700 cselib_preserve_constants
= false;
2701 cselib_any_perm_equivs
= false;
2702 cfa_base_preserved_val
= NULL
;
2703 cfa_base_preserved_regno
= INVALID_REGNUM
;
2704 free_alloc_pool (elt_list_pool
);
2705 free_alloc_pool (elt_loc_list_pool
);
2706 free_alloc_pool (cselib_val_pool
);
2707 free_alloc_pool (value_pool
);
2708 cselib_clear_table ();
2709 htab_delete (cselib_hash_table
);
2712 cselib_hash_table
= 0;
2713 n_useless_values
= 0;
2714 n_useless_debug_values
= 0;
2719 /* Dump the cselib_val *X to FILE *info. */
2722 dump_cselib_val (void **x
, void *info
)
2724 cselib_val
*v
= (cselib_val
*)*x
;
2725 FILE *out
= (FILE *)info
;
2726 bool need_lf
= true;
2728 print_inline_rtx (out
, v
->val_rtx
, 0);
2732 struct elt_loc_list
*l
= v
->locs
;
2738 fputs (" locs:", out
);
2741 if (l
->setting_insn
)
2742 fprintf (out
, "\n from insn %i ",
2743 INSN_UID (l
->setting_insn
));
2745 fprintf (out
, "\n ");
2746 print_inline_rtx (out
, l
->loc
, 4);
2748 while ((l
= l
->next
));
2753 fputs (" no locs", out
);
2759 struct elt_list
*e
= v
->addr_list
;
2765 fputs (" addr list:", out
);
2769 print_inline_rtx (out
, e
->elt
->val_rtx
, 2);
2771 while ((e
= e
->next
));
2776 fputs (" no addrs", out
);
2780 if (v
->next_containing_mem
== &dummy_val
)
2781 fputs (" last mem\n", out
);
2782 else if (v
->next_containing_mem
)
2784 fputs (" next mem ", out
);
2785 print_inline_rtx (out
, v
->next_containing_mem
->val_rtx
, 2);
2794 /* Dump to OUT everything in the CSELIB table. */
2797 dump_cselib_table (FILE *out
)
2799 fprintf (out
, "cselib hash table:\n");
2800 htab_traverse (cselib_hash_table
, dump_cselib_val
, out
);
2801 if (first_containing_mem
!= &dummy_val
)
2803 fputs ("first mem ", out
);
2804 print_inline_rtx (out
, first_containing_mem
->val_rtx
, 2);
2807 fprintf (out
, "next uid %i\n", next_uid
);
2810 #include "gt-cselib.h"