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 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
->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
);
480 htab_empty (cselib_hash_table
);
482 n_useless_values
= 0;
483 n_useless_debug_values
= 0;
488 first_containing_mem
= &dummy_val
;
491 /* Return the number of the next value that will be generated. */
494 cselib_get_next_uid (void)
499 /* See the documentation of cselib_find_slot below. */
500 static enum machine_mode find_slot_memmode
;
502 /* Search for X, whose hashcode is HASH, in CSELIB_HASH_TABLE,
503 INSERTing if requested. When X is part of the address of a MEM,
504 MEMMODE should specify the mode of the MEM. While searching the
505 table, MEMMODE is held in FIND_SLOT_MEMMODE, so that autoinc RTXs
506 in X can be resolved. */
509 cselib_find_slot (rtx x
, hashval_t hash
, enum insert_option insert
,
510 enum machine_mode memmode
)
513 find_slot_memmode
= memmode
;
514 slot
= htab_find_slot_with_hash (cselib_hash_table
, x
, hash
, insert
);
515 find_slot_memmode
= VOIDmode
;
519 /* The equality test for our hash table. The first argument ENTRY is a table
520 element (i.e. a cselib_val), while the second arg X is an rtx. We know
521 that all callers of htab_find_slot_with_hash will wrap CONST_INTs into a
522 CONST of an appropriate mode. */
525 entry_and_rtx_equal_p (const void *entry
, const void *x_arg
)
527 struct elt_loc_list
*l
;
528 const cselib_val
*const v
= (const cselib_val
*) entry
;
529 rtx x
= CONST_CAST_RTX ((const_rtx
)x_arg
);
530 enum machine_mode mode
= GET_MODE (x
);
532 gcc_assert (!CONST_INT_P (x
) && GET_CODE (x
) != CONST_FIXED
533 && (mode
!= VOIDmode
|| GET_CODE (x
) != CONST_DOUBLE
));
535 if (mode
!= GET_MODE (v
->val_rtx
))
538 /* Unwrap X if necessary. */
539 if (GET_CODE (x
) == CONST
540 && (CONST_INT_P (XEXP (x
, 0))
541 || GET_CODE (XEXP (x
, 0)) == CONST_FIXED
542 || GET_CODE (XEXP (x
, 0)) == CONST_DOUBLE
))
545 /* We don't guarantee that distinct rtx's have different hash values,
546 so we need to do a comparison. */
547 for (l
= v
->locs
; l
; l
= l
->next
)
548 if (rtx_equal_for_cselib_1 (l
->loc
, x
, find_slot_memmode
))
550 promote_debug_loc (l
);
557 /* The hash function for our hash table. The value is always computed with
558 cselib_hash_rtx when adding an element; this function just extracts the
559 hash value from a cselib_val structure. */
562 get_value_hash (const void *entry
)
564 const cselib_val
*const v
= (const cselib_val
*) entry
;
568 /* Return true if X contains a VALUE rtx. If ONLY_USELESS is set, we
569 only return true for values which point to a cselib_val whose value
570 element has been set to zero, which implies the cselib_val will be
574 references_value_p (const_rtx x
, int only_useless
)
576 const enum rtx_code code
= GET_CODE (x
);
577 const char *fmt
= GET_RTX_FORMAT (code
);
580 if (GET_CODE (x
) == VALUE
581 && (! only_useless
||
582 (CSELIB_VAL_PTR (x
)->locs
== 0 && !PRESERVED_VALUE_P (x
))))
585 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
587 if (fmt
[i
] == 'e' && references_value_p (XEXP (x
, i
), only_useless
))
589 else if (fmt
[i
] == 'E')
590 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
591 if (references_value_p (XVECEXP (x
, i
, j
), only_useless
))
598 /* For all locations found in X, delete locations that reference useless
599 values (i.e. values without any location). Called through
603 discard_useless_locs (void **x
, void *info ATTRIBUTE_UNUSED
)
605 cselib_val
*v
= (cselib_val
*)*x
;
606 struct elt_loc_list
**p
= &v
->locs
;
607 bool had_locs
= v
->locs
!= NULL
;
608 rtx setting_insn
= v
->locs
? v
->locs
->setting_insn
: NULL
;
612 if (references_value_p ((*p
)->loc
, 1))
613 unchain_one_elt_loc_list (p
);
618 if (had_locs
&& v
->locs
== 0 && !PRESERVED_VALUE_P (v
->val_rtx
))
620 if (setting_insn
&& DEBUG_INSN_P (setting_insn
))
621 n_useless_debug_values
++;
624 values_became_useless
= 1;
629 /* If X is a value with no locations, remove it from the hashtable. */
632 discard_useless_values (void **x
, void *info ATTRIBUTE_UNUSED
)
634 cselib_val
*v
= (cselib_val
*)*x
;
636 if (v
->locs
== 0 && !PRESERVED_VALUE_P (v
->val_rtx
))
638 if (cselib_discard_hook
)
639 cselib_discard_hook (v
);
641 CSELIB_VAL_PTR (v
->val_rtx
) = NULL
;
642 htab_clear_slot (cselib_hash_table
, x
);
643 unchain_one_value (v
);
650 /* Clean out useless values (i.e. those which no longer have locations
651 associated with them) from the hash table. */
654 remove_useless_values (void)
658 /* First pass: eliminate locations that reference the value. That in
659 turn can make more values useless. */
662 values_became_useless
= 0;
663 htab_traverse (cselib_hash_table
, discard_useless_locs
, 0);
665 while (values_became_useless
);
667 /* Second pass: actually remove the values. */
669 p
= &first_containing_mem
;
670 for (v
= *p
; v
!= &dummy_val
; v
= v
->next_containing_mem
)
671 if (v
->locs
&& v
== canonical_cselib_val (v
))
674 p
= &(*p
)->next_containing_mem
;
678 n_useless_values
+= n_useless_debug_values
;
679 n_debug_values
-= n_useless_debug_values
;
680 n_useless_debug_values
= 0;
682 htab_traverse (cselib_hash_table
, discard_useless_values
, 0);
684 gcc_assert (!n_useless_values
);
687 /* Arrange for a value to not be removed from the hash table even if
688 it becomes useless. */
691 cselib_preserve_value (cselib_val
*v
)
693 PRESERVED_VALUE_P (v
->val_rtx
) = 1;
696 /* Test whether a value is preserved. */
699 cselib_preserved_value_p (cselib_val
*v
)
701 return PRESERVED_VALUE_P (v
->val_rtx
);
704 /* Arrange for a REG value to be assumed constant through the whole function,
705 never invalidated and preserved across cselib_reset_table calls. */
708 cselib_preserve_cfa_base_value (cselib_val
*v
, unsigned int regno
)
710 if (cselib_preserve_constants
712 && REG_P (v
->locs
->loc
))
714 cfa_base_preserved_val
= v
;
715 cfa_base_preserved_regno
= regno
;
719 /* Clean all non-constant expressions in the hash table, but retain
723 cselib_preserve_only_values (void)
727 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; i
++)
728 cselib_invalidate_regno (i
, reg_raw_mode
[i
]);
730 cselib_invalidate_mem (callmem
);
732 remove_useless_values ();
734 gcc_assert (first_containing_mem
== &dummy_val
);
737 /* Return the mode in which a register was last set. If X is not a
738 register, return its mode. If the mode in which the register was
739 set is not known, or the value was already clobbered, return
743 cselib_reg_set_mode (const_rtx x
)
748 if (REG_VALUES (REGNO (x
)) == NULL
749 || REG_VALUES (REGNO (x
))->elt
== NULL
)
752 return GET_MODE (REG_VALUES (REGNO (x
))->elt
->val_rtx
);
755 /* Return nonzero if we can prove that X and Y contain the same value, taking
756 our gathered information into account. */
759 rtx_equal_for_cselib_p (rtx x
, rtx y
)
761 return rtx_equal_for_cselib_1 (x
, y
, VOIDmode
);
764 /* If x is a PLUS or an autoinc operation, expand the operation,
765 storing the offset, if any, in *OFF. */
768 autoinc_split (rtx x
, rtx
*off
, enum machine_mode memmode
)
770 switch (GET_CODE (x
))
777 if (memmode
== VOIDmode
)
780 *off
= GEN_INT (-GET_MODE_SIZE (memmode
));
785 if (memmode
== VOIDmode
)
788 *off
= GEN_INT (GET_MODE_SIZE (memmode
));
804 /* Return nonzero if we can prove that X and Y contain the same value,
805 taking our gathered information into account. MEMMODE holds the
806 mode of the enclosing MEM, if any, as required to deal with autoinc
807 addressing modes. If X and Y are not (known to be) part of
808 addresses, MEMMODE should be VOIDmode. */
811 rtx_equal_for_cselib_1 (rtx x
, rtx y
, enum machine_mode memmode
)
817 if (REG_P (x
) || MEM_P (x
))
819 cselib_val
*e
= cselib_lookup (x
, GET_MODE (x
), 0, memmode
);
825 if (REG_P (y
) || MEM_P (y
))
827 cselib_val
*e
= cselib_lookup (y
, GET_MODE (y
), 0, memmode
);
836 if (GET_CODE (x
) == VALUE
)
838 cselib_val
*e
= canonical_cselib_val (CSELIB_VAL_PTR (x
));
839 struct elt_loc_list
*l
;
841 if (GET_CODE (y
) == VALUE
)
842 return e
== canonical_cselib_val (CSELIB_VAL_PTR (y
));
844 for (l
= e
->locs
; l
; l
= l
->next
)
848 /* Avoid infinite recursion. We know we have the canonical
849 value, so we can just skip any values in the equivalence
851 if (REG_P (t
) || MEM_P (t
) || GET_CODE (t
) == VALUE
)
853 else if (rtx_equal_for_cselib_1 (t
, y
, memmode
))
859 else if (GET_CODE (y
) == VALUE
)
861 cselib_val
*e
= canonical_cselib_val (CSELIB_VAL_PTR (y
));
862 struct elt_loc_list
*l
;
864 for (l
= e
->locs
; l
; l
= l
->next
)
868 if (REG_P (t
) || MEM_P (t
) || GET_CODE (t
) == VALUE
)
870 else if (rtx_equal_for_cselib_1 (x
, t
, memmode
))
877 if (GET_MODE (x
) != GET_MODE (y
))
880 if (GET_CODE (x
) != GET_CODE (y
))
882 rtx xorig
= x
, yorig
= y
;
883 rtx xoff
= NULL
, yoff
= NULL
;
885 x
= autoinc_split (x
, &xoff
, memmode
);
886 y
= autoinc_split (y
, &yoff
, memmode
);
891 if (xoff
&& !rtx_equal_for_cselib_1 (xoff
, yoff
, memmode
))
894 /* Don't recurse if nothing changed. */
895 if (x
!= xorig
|| y
!= yorig
)
896 return rtx_equal_for_cselib_1 (x
, y
, memmode
);
901 /* These won't be handled correctly by the code below. */
902 switch (GET_CODE (x
))
909 case DEBUG_IMPLICIT_PTR
:
910 return DEBUG_IMPLICIT_PTR_DECL (x
)
911 == DEBUG_IMPLICIT_PTR_DECL (y
);
913 case DEBUG_PARAMETER_REF
:
914 return DEBUG_PARAMETER_REF_DECL (x
)
915 == DEBUG_PARAMETER_REF_DECL (y
);
918 /* ENTRY_VALUEs are function invariant, it is thus undesirable to
919 use rtx_equal_for_cselib_1 to compare the operands. */
920 return rtx_equal_p (ENTRY_VALUE_EXP (x
), ENTRY_VALUE_EXP (y
));
923 return XEXP (x
, 0) == XEXP (y
, 0);
926 /* We have to compare any autoinc operations in the addresses
927 using this MEM's mode. */
928 return rtx_equal_for_cselib_1 (XEXP (x
, 0), XEXP (y
, 0), GET_MODE (x
));
935 fmt
= GET_RTX_FORMAT (code
);
937 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
944 if (XWINT (x
, i
) != XWINT (y
, i
))
950 if (XINT (x
, i
) != XINT (y
, i
))
956 /* Two vectors must have the same length. */
957 if (XVECLEN (x
, i
) != XVECLEN (y
, i
))
960 /* And the corresponding elements must match. */
961 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
962 if (! rtx_equal_for_cselib_1 (XVECEXP (x
, i
, j
),
963 XVECEXP (y
, i
, j
), memmode
))
969 && targetm
.commutative_p (x
, UNKNOWN
)
970 && rtx_equal_for_cselib_1 (XEXP (x
, 1), XEXP (y
, 0), memmode
)
971 && rtx_equal_for_cselib_1 (XEXP (x
, 0), XEXP (y
, 1), memmode
))
973 if (! rtx_equal_for_cselib_1 (XEXP (x
, i
), XEXP (y
, i
), memmode
))
979 if (strcmp (XSTR (x
, i
), XSTR (y
, i
)))
984 /* These are just backpointers, so they don't matter. */
991 /* It is believed that rtx's at this level will never
992 contain anything but integers and other rtx's,
993 except for within LABEL_REFs and SYMBOL_REFs. */
1001 /* We need to pass down the mode of constants through the hash table
1002 functions. For that purpose, wrap them in a CONST of the appropriate
1005 wrap_constant (enum machine_mode mode
, rtx x
)
1007 if (!CONST_INT_P (x
) && GET_CODE (x
) != CONST_FIXED
1008 && (GET_CODE (x
) != CONST_DOUBLE
|| GET_MODE (x
) != VOIDmode
))
1010 gcc_assert (mode
!= VOIDmode
);
1011 return gen_rtx_CONST (mode
, x
);
1014 /* Hash an rtx. Return 0 if we couldn't hash the rtx.
1015 For registers and memory locations, we look up their cselib_val structure
1016 and return its VALUE element.
1017 Possible reasons for return 0 are: the object is volatile, or we couldn't
1018 find a register or memory location in the table and CREATE is zero. If
1019 CREATE is nonzero, table elts are created for regs and mem.
1020 N.B. this hash function returns the same hash value for RTXes that
1021 differ only in the order of operands, thus it is suitable for comparisons
1022 that take commutativity into account.
1023 If we wanted to also support associative rules, we'd have to use a different
1024 strategy to avoid returning spurious 0, e.g. return ~(~0U >> 1) .
1025 MEMMODE indicates the mode of an enclosing MEM, and it's only
1026 used to compute autoinc values.
1027 We used to have a MODE argument for hashing for CONST_INTs, but that
1028 didn't make sense, since it caused spurious hash differences between
1029 (set (reg:SI 1) (const_int))
1030 (plus:SI (reg:SI 2) (reg:SI 1))
1032 (plus:SI (reg:SI 2) (const_int))
1033 If the mode is important in any context, it must be checked specifically
1034 in a comparison anyway, since relying on hash differences is unsafe. */
1037 cselib_hash_rtx (rtx x
, int create
, enum machine_mode memmode
)
1043 unsigned int hash
= 0;
1045 code
= GET_CODE (x
);
1046 hash
+= (unsigned) code
+ (unsigned) GET_MODE (x
);
1051 e
= CSELIB_VAL_PTR (x
);
1056 e
= cselib_lookup (x
, GET_MODE (x
), create
, memmode
);
1063 hash
+= ((unsigned) DEBUG_EXPR
<< 7)
1064 + DEBUG_TEMP_UID (DEBUG_EXPR_TREE_DECL (x
));
1065 return hash
? hash
: (unsigned int) DEBUG_EXPR
;
1067 case DEBUG_IMPLICIT_PTR
:
1068 hash
+= ((unsigned) DEBUG_IMPLICIT_PTR
<< 7)
1069 + DECL_UID (DEBUG_IMPLICIT_PTR_DECL (x
));
1070 return hash
? hash
: (unsigned int) DEBUG_IMPLICIT_PTR
;
1072 case DEBUG_PARAMETER_REF
:
1073 hash
+= ((unsigned) DEBUG_PARAMETER_REF
<< 7)
1074 + DECL_UID (DEBUG_PARAMETER_REF_DECL (x
));
1075 return hash
? hash
: (unsigned int) DEBUG_PARAMETER_REF
;
1078 /* ENTRY_VALUEs are function invariant, thus try to avoid
1079 recursing on argument if ENTRY_VALUE is one of the
1080 forms emitted by expand_debug_expr, otherwise
1081 ENTRY_VALUE hash would depend on the current value
1082 in some register or memory. */
1083 if (REG_P (ENTRY_VALUE_EXP (x
)))
1084 hash
+= (unsigned int) REG
1085 + (unsigned int) GET_MODE (ENTRY_VALUE_EXP (x
))
1086 + (unsigned int) REGNO (ENTRY_VALUE_EXP (x
));
1087 else if (MEM_P (ENTRY_VALUE_EXP (x
))
1088 && REG_P (XEXP (ENTRY_VALUE_EXP (x
), 0)))
1089 hash
+= (unsigned int) MEM
1090 + (unsigned int) GET_MODE (XEXP (ENTRY_VALUE_EXP (x
), 0))
1091 + (unsigned int) REGNO (XEXP (ENTRY_VALUE_EXP (x
), 0));
1093 hash
+= cselib_hash_rtx (ENTRY_VALUE_EXP (x
), create
, memmode
);
1094 return hash
? hash
: (unsigned int) ENTRY_VALUE
;
1097 hash
+= ((unsigned) CONST_INT
<< 7) + INTVAL (x
);
1098 return hash
? hash
: (unsigned int) CONST_INT
;
1101 /* This is like the general case, except that it only counts
1102 the integers representing the constant. */
1103 hash
+= (unsigned) code
+ (unsigned) GET_MODE (x
);
1104 if (GET_MODE (x
) != VOIDmode
)
1105 hash
+= real_hash (CONST_DOUBLE_REAL_VALUE (x
));
1107 hash
+= ((unsigned) CONST_DOUBLE_LOW (x
)
1108 + (unsigned) CONST_DOUBLE_HIGH (x
));
1109 return hash
? hash
: (unsigned int) CONST_DOUBLE
;
1112 hash
+= (unsigned int) code
+ (unsigned int) GET_MODE (x
);
1113 hash
+= fixed_hash (CONST_FIXED_VALUE (x
));
1114 return hash
? hash
: (unsigned int) CONST_FIXED
;
1121 units
= CONST_VECTOR_NUNITS (x
);
1123 for (i
= 0; i
< units
; ++i
)
1125 elt
= CONST_VECTOR_ELT (x
, i
);
1126 hash
+= cselib_hash_rtx (elt
, 0, memmode
);
1132 /* Assume there is only one rtx object for any given label. */
1134 /* We don't hash on the address of the CODE_LABEL to avoid bootstrap
1135 differences and differences between each stage's debugging dumps. */
1136 hash
+= (((unsigned int) LABEL_REF
<< 7)
1137 + CODE_LABEL_NUMBER (XEXP (x
, 0)));
1138 return hash
? hash
: (unsigned int) LABEL_REF
;
1142 /* Don't hash on the symbol's address to avoid bootstrap differences.
1143 Different hash values may cause expressions to be recorded in
1144 different orders and thus different registers to be used in the
1145 final assembler. This also avoids differences in the dump files
1146 between various stages. */
1148 const unsigned char *p
= (const unsigned char *) XSTR (x
, 0);
1151 h
+= (h
<< 7) + *p
++; /* ??? revisit */
1153 hash
+= ((unsigned int) SYMBOL_REF
<< 7) + h
;
1154 return hash
? hash
: (unsigned int) SYMBOL_REF
;
1159 /* We can't compute these without knowing the MEM mode. */
1160 gcc_assert (memmode
!= VOIDmode
);
1161 i
= GET_MODE_SIZE (memmode
);
1162 if (code
== PRE_DEC
)
1164 /* Adjust the hash so that (mem:MEMMODE (pre_* (reg))) hashes
1165 like (mem:MEMMODE (plus (reg) (const_int I))). */
1166 hash
+= (unsigned) PLUS
- (unsigned)code
1167 + cselib_hash_rtx (XEXP (x
, 0), create
, memmode
)
1168 + cselib_hash_rtx (GEN_INT (i
), create
, memmode
);
1169 return hash
? hash
: 1 + (unsigned) PLUS
;
1172 gcc_assert (memmode
!= VOIDmode
);
1173 return cselib_hash_rtx (XEXP (x
, 1), create
, memmode
);
1178 gcc_assert (memmode
!= VOIDmode
);
1179 return cselib_hash_rtx (XEXP (x
, 0), create
, memmode
);
1184 case UNSPEC_VOLATILE
:
1188 if (MEM_VOLATILE_P (x
))
1197 i
= GET_RTX_LENGTH (code
) - 1;
1198 fmt
= GET_RTX_FORMAT (code
);
1205 rtx tem
= XEXP (x
, i
);
1206 unsigned int tem_hash
= cselib_hash_rtx (tem
, create
, memmode
);
1215 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
1217 unsigned int tem_hash
1218 = cselib_hash_rtx (XVECEXP (x
, i
, j
), create
, memmode
);
1229 const unsigned char *p
= (const unsigned char *) XSTR (x
, i
);
1238 hash
+= XINT (x
, i
);
1251 return hash
? hash
: 1 + (unsigned int) GET_CODE (x
);
1254 /* Create a new value structure for VALUE and initialize it. The mode of the
1257 static inline cselib_val
*
1258 new_cselib_val (unsigned int hash
, enum machine_mode mode
, rtx x
)
1260 cselib_val
*e
= (cselib_val
*) pool_alloc (cselib_val_pool
);
1263 gcc_assert (next_uid
);
1266 e
->uid
= next_uid
++;
1267 /* We use an alloc pool to allocate this RTL construct because it
1268 accounts for about 8% of the overall memory usage. We know
1269 precisely when we can have VALUE RTXen (when cselib is active)
1270 so we don't need to put them in garbage collected memory.
1271 ??? Why should a VALUE be an RTX in the first place? */
1272 e
->val_rtx
= (rtx
) pool_alloc (value_pool
);
1273 memset (e
->val_rtx
, 0, RTX_HDR_SIZE
);
1274 PUT_CODE (e
->val_rtx
, VALUE
);
1275 PUT_MODE (e
->val_rtx
, mode
);
1276 CSELIB_VAL_PTR (e
->val_rtx
) = e
;
1279 e
->next_containing_mem
= 0;
1281 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1283 fprintf (dump_file
, "cselib value %u:%u ", e
->uid
, hash
);
1284 if (flag_dump_noaddr
|| flag_dump_unnumbered
)
1285 fputs ("# ", dump_file
);
1287 fprintf (dump_file
, "%p ", (void*)e
);
1288 print_rtl_single (dump_file
, x
);
1289 fputc ('\n', dump_file
);
1295 /* ADDR_ELT is a value that is used as address. MEM_ELT is the value that
1296 contains the data at this address. X is a MEM that represents the
1297 value. Update the two value structures to represent this situation. */
1300 add_mem_for_addr (cselib_val
*addr_elt
, cselib_val
*mem_elt
, rtx x
)
1302 struct elt_loc_list
*l
;
1304 addr_elt
= canonical_cselib_val (addr_elt
);
1305 mem_elt
= canonical_cselib_val (mem_elt
);
1307 /* Avoid duplicates. */
1308 for (l
= mem_elt
->locs
; l
; l
= l
->next
)
1310 && CSELIB_VAL_PTR (XEXP (l
->loc
, 0)) == addr_elt
)
1312 promote_debug_loc (l
);
1316 addr_elt
->addr_list
= new_elt_list (addr_elt
->addr_list
, mem_elt
);
1317 new_elt_loc_list (mem_elt
,
1318 replace_equiv_address_nv (x
, addr_elt
->val_rtx
));
1319 if (mem_elt
->next_containing_mem
== NULL
)
1321 mem_elt
->next_containing_mem
= first_containing_mem
;
1322 first_containing_mem
= mem_elt
;
1326 /* Subroutine of cselib_lookup. Return a value for X, which is a MEM rtx.
1327 If CREATE, make a new one if we haven't seen it before. */
1330 cselib_lookup_mem (rtx x
, int create
)
1332 enum machine_mode mode
= GET_MODE (x
);
1333 enum machine_mode addr_mode
;
1336 cselib_val
*mem_elt
;
1339 if (MEM_VOLATILE_P (x
) || mode
== BLKmode
1340 || !cselib_record_memory
1341 || (FLOAT_MODE_P (mode
) && flag_float_store
))
1344 addr_mode
= GET_MODE (XEXP (x
, 0));
1345 if (addr_mode
== VOIDmode
)
1348 /* Look up the value for the address. */
1349 addr
= cselib_lookup (XEXP (x
, 0), addr_mode
, create
, mode
);
1353 addr
= canonical_cselib_val (addr
);
1354 /* Find a value that describes a value of our mode at that address. */
1355 for (l
= addr
->addr_list
; l
; l
= l
->next
)
1356 if (GET_MODE (l
->elt
->val_rtx
) == mode
)
1358 promote_debug_loc (l
->elt
->locs
);
1365 mem_elt
= new_cselib_val (next_uid
, mode
, x
);
1366 add_mem_for_addr (addr
, mem_elt
, x
);
1367 slot
= cselib_find_slot (wrap_constant (mode
, x
), mem_elt
->hash
,
1373 /* Search thru the possible substitutions in P. We prefer a non reg
1374 substitution because this allows us to expand the tree further. If
1375 we find, just a reg, take the lowest regno. There may be several
1376 non-reg results, we just take the first one because they will all
1377 expand to the same place. */
1380 expand_loc (struct elt_loc_list
*p
, struct expand_value_data
*evd
,
1383 rtx reg_result
= NULL
;
1384 unsigned int regno
= UINT_MAX
;
1385 struct elt_loc_list
*p_in
= p
;
1387 for (; p
; p
= p
->next
)
1389 /* Return these right away to avoid returning stack pointer based
1390 expressions for frame pointer and vice versa, which is something
1391 that would confuse DSE. See the comment in cselib_expand_value_rtx_1
1392 for more details. */
1394 && (REGNO (p
->loc
) == STACK_POINTER_REGNUM
1395 || REGNO (p
->loc
) == FRAME_POINTER_REGNUM
1396 || REGNO (p
->loc
) == HARD_FRAME_POINTER_REGNUM
1397 || REGNO (p
->loc
) == cfa_base_preserved_regno
))
1399 /* Avoid infinite recursion trying to expand a reg into a
1401 if ((REG_P (p
->loc
))
1402 && (REGNO (p
->loc
) < regno
)
1403 && !bitmap_bit_p (evd
->regs_active
, REGNO (p
->loc
)))
1405 reg_result
= p
->loc
;
1406 regno
= REGNO (p
->loc
);
1408 /* Avoid infinite recursion and do not try to expand the
1410 else if (GET_CODE (p
->loc
) == VALUE
1411 && CSELIB_VAL_PTR (p
->loc
)->locs
== p_in
)
1413 else if (!REG_P (p
->loc
))
1416 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1418 print_inline_rtx (dump_file
, p
->loc
, 0);
1419 fprintf (dump_file
, "\n");
1421 if (GET_CODE (p
->loc
) == LO_SUM
1422 && GET_CODE (XEXP (p
->loc
, 1)) == SYMBOL_REF
1424 && (note
= find_reg_note (p
->setting_insn
, REG_EQUAL
, NULL_RTX
))
1425 && XEXP (note
, 0) == XEXP (p
->loc
, 1))
1426 return XEXP (p
->loc
, 1);
1427 result
= cselib_expand_value_rtx_1 (p
->loc
, evd
, max_depth
- 1);
1434 if (regno
!= UINT_MAX
)
1437 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1438 fprintf (dump_file
, "r%d\n", regno
);
1440 result
= cselib_expand_value_rtx_1 (reg_result
, evd
, max_depth
- 1);
1445 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1449 print_inline_rtx (dump_file
, reg_result
, 0);
1450 fprintf (dump_file
, "\n");
1453 fprintf (dump_file
, "NULL\n");
1459 /* Forward substitute and expand an expression out to its roots.
1460 This is the opposite of common subexpression. Because local value
1461 numbering is such a weak optimization, the expanded expression is
1462 pretty much unique (not from a pointer equals point of view but
1463 from a tree shape point of view.
1465 This function returns NULL if the expansion fails. The expansion
1466 will fail if there is no value number for one of the operands or if
1467 one of the operands has been overwritten between the current insn
1468 and the beginning of the basic block. For instance x has no
1474 REGS_ACTIVE is a scratch bitmap that should be clear when passing in.
1475 It is clear on return. */
1478 cselib_expand_value_rtx (rtx orig
, bitmap regs_active
, int max_depth
)
1480 struct expand_value_data evd
;
1482 evd
.regs_active
= regs_active
;
1483 evd
.callback
= NULL
;
1484 evd
.callback_arg
= NULL
;
1487 return cselib_expand_value_rtx_1 (orig
, &evd
, max_depth
);
1490 /* Same as cselib_expand_value_rtx, but using a callback to try to
1491 resolve some expressions. The CB function should return ORIG if it
1492 can't or does not want to deal with a certain RTX. Any other
1493 return value, including NULL, will be used as the expansion for
1494 VALUE, without any further changes. */
1497 cselib_expand_value_rtx_cb (rtx orig
, bitmap regs_active
, int max_depth
,
1498 cselib_expand_callback cb
, void *data
)
1500 struct expand_value_data evd
;
1502 evd
.regs_active
= regs_active
;
1504 evd
.callback_arg
= data
;
1507 return cselib_expand_value_rtx_1 (orig
, &evd
, max_depth
);
1510 /* Similar to cselib_expand_value_rtx_cb, but no rtxs are actually copied
1511 or simplified. Useful to find out whether cselib_expand_value_rtx_cb
1512 would return NULL or non-NULL, without allocating new rtx. */
1515 cselib_dummy_expand_value_rtx_cb (rtx orig
, bitmap regs_active
, int max_depth
,
1516 cselib_expand_callback cb
, void *data
)
1518 struct expand_value_data evd
;
1520 evd
.regs_active
= regs_active
;
1522 evd
.callback_arg
= data
;
1525 return cselib_expand_value_rtx_1 (orig
, &evd
, max_depth
) != NULL
;
1528 /* Internal implementation of cselib_expand_value_rtx and
1529 cselib_expand_value_rtx_cb. */
1532 cselib_expand_value_rtx_1 (rtx orig
, struct expand_value_data
*evd
,
1538 const char *format_ptr
;
1539 enum machine_mode mode
;
1541 code
= GET_CODE (orig
);
1543 /* For the context of dse, if we end up expand into a huge tree, we
1544 will not have a useful address, so we might as well just give up
1553 struct elt_list
*l
= REG_VALUES (REGNO (orig
));
1555 if (l
&& l
->elt
== NULL
)
1557 for (; l
; l
= l
->next
)
1558 if (GET_MODE (l
->elt
->val_rtx
) == GET_MODE (orig
))
1561 unsigned regno
= REGNO (orig
);
1563 /* The only thing that we are not willing to do (this
1564 is requirement of dse and if others potential uses
1565 need this function we should add a parm to control
1566 it) is that we will not substitute the
1567 STACK_POINTER_REGNUM, FRAME_POINTER or the
1570 These expansions confuses the code that notices that
1571 stores into the frame go dead at the end of the
1572 function and that the frame is not effected by calls
1573 to subroutines. If you allow the
1574 STACK_POINTER_REGNUM substitution, then dse will
1575 think that parameter pushing also goes dead which is
1576 wrong. If you allow the FRAME_POINTER or the
1577 HARD_FRAME_POINTER then you lose the opportunity to
1578 make the frame assumptions. */
1579 if (regno
== STACK_POINTER_REGNUM
1580 || regno
== FRAME_POINTER_REGNUM
1581 || regno
== HARD_FRAME_POINTER_REGNUM
1582 || regno
== cfa_base_preserved_regno
)
1585 bitmap_set_bit (evd
->regs_active
, regno
);
1587 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1588 fprintf (dump_file
, "expanding: r%d into: ", regno
);
1590 result
= expand_loc (l
->elt
->locs
, evd
, max_depth
);
1591 bitmap_clear_bit (evd
->regs_active
, regno
);
1608 /* SCRATCH must be shared because they represent distinct values. */
1611 if (REG_P (XEXP (orig
, 0)) && HARD_REGISTER_NUM_P (REGNO (XEXP (orig
, 0))))
1616 if (shared_const_p (orig
))
1626 subreg
= evd
->callback (orig
, evd
->regs_active
, max_depth
,
1632 subreg
= cselib_expand_value_rtx_1 (SUBREG_REG (orig
), evd
,
1636 scopy
= simplify_gen_subreg (GET_MODE (orig
), subreg
,
1637 GET_MODE (SUBREG_REG (orig
)),
1638 SUBREG_BYTE (orig
));
1640 || (GET_CODE (scopy
) == SUBREG
1641 && !REG_P (SUBREG_REG (scopy
))
1642 && !MEM_P (SUBREG_REG (scopy
))))
1652 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1654 fputs ("\nexpanding ", dump_file
);
1655 print_rtl_single (dump_file
, orig
);
1656 fputs (" into...", dump_file
);
1661 result
= evd
->callback (orig
, evd
->regs_active
, max_depth
,
1668 result
= expand_loc (CSELIB_VAL_PTR (orig
)->locs
, evd
, max_depth
);
1674 return evd
->callback (orig
, evd
->regs_active
, max_depth
,
1682 /* Copy the various flags, fields, and other information. We assume
1683 that all fields need copying, and then clear the fields that should
1684 not be copied. That is the sensible default behavior, and forces
1685 us to explicitly document why we are *not* copying a flag. */
1689 copy
= shallow_copy_rtx (orig
);
1691 format_ptr
= GET_RTX_FORMAT (code
);
1693 for (i
= 0; i
< GET_RTX_LENGTH (code
); i
++)
1694 switch (*format_ptr
++)
1697 if (XEXP (orig
, i
) != NULL
)
1699 rtx result
= cselib_expand_value_rtx_1 (XEXP (orig
, i
), evd
,
1704 XEXP (copy
, i
) = result
;
1710 if (XVEC (orig
, i
) != NULL
)
1713 XVEC (copy
, i
) = rtvec_alloc (XVECLEN (orig
, i
));
1714 for (j
= 0; j
< XVECLEN (orig
, i
); j
++)
1716 rtx result
= cselib_expand_value_rtx_1 (XVECEXP (orig
, i
, j
),
1717 evd
, max_depth
- 1);
1721 XVECEXP (copy
, i
, j
) = result
;
1735 /* These are left unchanged. */
1745 mode
= GET_MODE (copy
);
1746 /* If an operand has been simplified into CONST_INT, which doesn't
1747 have a mode and the mode isn't derivable from whole rtx's mode,
1748 try simplify_*_operation first with mode from original's operand
1749 and as a fallback wrap CONST_INT into gen_rtx_CONST. */
1751 switch (GET_RTX_CLASS (code
))
1754 if (CONST_INT_P (XEXP (copy
, 0))
1755 && GET_MODE (XEXP (orig
, 0)) != VOIDmode
)
1757 scopy
= simplify_unary_operation (code
, mode
, XEXP (copy
, 0),
1758 GET_MODE (XEXP (orig
, 0)));
1763 case RTX_COMM_ARITH
:
1765 /* These expressions can derive operand modes from the whole rtx's mode. */
1768 case RTX_BITFIELD_OPS
:
1769 if (CONST_INT_P (XEXP (copy
, 0))
1770 && GET_MODE (XEXP (orig
, 0)) != VOIDmode
)
1772 scopy
= simplify_ternary_operation (code
, mode
,
1773 GET_MODE (XEXP (orig
, 0)),
1774 XEXP (copy
, 0), XEXP (copy
, 1),
1781 case RTX_COMM_COMPARE
:
1782 if (CONST_INT_P (XEXP (copy
, 0))
1783 && GET_MODE (XEXP (copy
, 1)) == VOIDmode
1784 && (GET_MODE (XEXP (orig
, 0)) != VOIDmode
1785 || GET_MODE (XEXP (orig
, 1)) != VOIDmode
))
1787 scopy
= simplify_relational_operation (code
, mode
,
1788 (GET_MODE (XEXP (orig
, 0))
1790 ? GET_MODE (XEXP (orig
, 0))
1791 : GET_MODE (XEXP (orig
, 1)),
1801 scopy
= simplify_rtx (copy
);
1807 /* Walk rtx X and replace all occurrences of REG and MEM subexpressions
1808 with VALUE expressions. This way, it becomes independent of changes
1809 to registers and memory.
1810 X isn't actually modified; if modifications are needed, new rtl is
1811 allocated. However, the return value can share rtl with X.
1812 If X is within a MEM, MEMMODE must be the mode of the MEM. */
1815 cselib_subst_to_values (rtx x
, enum machine_mode memmode
)
1817 enum rtx_code code
= GET_CODE (x
);
1818 const char *fmt
= GET_RTX_FORMAT (code
);
1827 l
= REG_VALUES (REGNO (x
));
1828 if (l
&& l
->elt
== NULL
)
1830 for (; l
; l
= l
->next
)
1831 if (GET_MODE (l
->elt
->val_rtx
) == GET_MODE (x
))
1832 return l
->elt
->val_rtx
;
1837 e
= cselib_lookup_mem (x
, 0);
1838 /* This used to happen for autoincrements, but we deal with them
1839 properly now. Remove the if stmt for the next release. */
1842 /* Assign a value that doesn't match any other. */
1843 e
= new_cselib_val (next_uid
, GET_MODE (x
), x
);
1848 e
= cselib_lookup (x
, GET_MODE (x
), 0, memmode
);
1861 gcc_assert (memmode
!= VOIDmode
);
1862 i
= GET_MODE_SIZE (memmode
);
1863 if (code
== PRE_DEC
)
1865 return cselib_subst_to_values (plus_constant (XEXP (x
, 0), i
),
1869 gcc_assert (memmode
!= VOIDmode
);
1870 return cselib_subst_to_values (XEXP (x
, 1), memmode
);
1875 gcc_assert (memmode
!= VOIDmode
);
1876 return cselib_subst_to_values (XEXP (x
, 0), memmode
);
1882 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
1886 rtx t
= cselib_subst_to_values (XEXP (x
, i
), memmode
);
1888 if (t
!= XEXP (x
, i
))
1891 copy
= shallow_copy_rtx (x
);
1895 else if (fmt
[i
] == 'E')
1899 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
1901 rtx t
= cselib_subst_to_values (XVECEXP (x
, i
, j
), memmode
);
1903 if (t
!= XVECEXP (x
, i
, j
))
1905 if (XVEC (x
, i
) == XVEC (copy
, i
))
1908 copy
= shallow_copy_rtx (x
);
1909 XVEC (copy
, i
) = shallow_copy_rtvec (XVEC (x
, i
));
1911 XVECEXP (copy
, i
, j
) = t
;
1920 /* Wrapper for cselib_subst_to_values, that indicates X is in INSN. */
1923 cselib_subst_to_values_from_insn (rtx x
, enum machine_mode memmode
, rtx insn
)
1926 gcc_assert (!cselib_current_insn
);
1927 cselib_current_insn
= insn
;
1928 ret
= cselib_subst_to_values (x
, memmode
);
1929 cselib_current_insn
= NULL
;
1933 /* Look up the rtl expression X in our tables and return the value it
1934 has. If CREATE is zero, we return NULL if we don't know the value.
1935 Otherwise, we create a new one if possible, using mode MODE if X
1936 doesn't have a mode (i.e. because it's a constant). When X is part
1937 of an address, MEMMODE should be the mode of the enclosing MEM if
1938 we're tracking autoinc expressions. */
1941 cselib_lookup_1 (rtx x
, enum machine_mode mode
,
1942 int create
, enum machine_mode memmode
)
1946 unsigned int hashval
;
1948 if (GET_MODE (x
) != VOIDmode
)
1949 mode
= GET_MODE (x
);
1951 if (GET_CODE (x
) == VALUE
)
1952 return CSELIB_VAL_PTR (x
);
1957 unsigned int i
= REGNO (x
);
1960 if (l
&& l
->elt
== NULL
)
1962 for (; l
; l
= l
->next
)
1963 if (mode
== GET_MODE (l
->elt
->val_rtx
))
1965 promote_debug_loc (l
->elt
->locs
);
1972 if (i
< FIRST_PSEUDO_REGISTER
)
1974 unsigned int n
= hard_regno_nregs
[i
][mode
];
1976 if (n
> max_value_regs
)
1980 e
= new_cselib_val (next_uid
, GET_MODE (x
), x
);
1981 new_elt_loc_list (e
, x
);
1982 if (REG_VALUES (i
) == 0)
1984 /* Maintain the invariant that the first entry of
1985 REG_VALUES, if present, must be the value used to set the
1986 register, or NULL. */
1987 used_regs
[n_used_regs
++] = i
;
1988 REG_VALUES (i
) = new_elt_list (REG_VALUES (i
), NULL
);
1990 else if (cselib_preserve_constants
1991 && GET_MODE_CLASS (mode
) == MODE_INT
)
1993 /* During var-tracking, try harder to find equivalences
1994 for SUBREGs. If a setter sets say a DImode register
1995 and user uses that register only in SImode, add a lowpart
1997 struct elt_list
*lwider
= NULL
;
1999 if (l
&& l
->elt
== NULL
)
2001 for (; l
; l
= l
->next
)
2002 if (GET_MODE_CLASS (GET_MODE (l
->elt
->val_rtx
)) == MODE_INT
2003 && GET_MODE_SIZE (GET_MODE (l
->elt
->val_rtx
))
2004 > GET_MODE_SIZE (mode
)
2006 || GET_MODE_SIZE (GET_MODE (l
->elt
->val_rtx
))
2007 < GET_MODE_SIZE (GET_MODE (lwider
->elt
->val_rtx
))))
2009 struct elt_loc_list
*el
;
2010 if (i
< FIRST_PSEUDO_REGISTER
2011 && hard_regno_nregs
[i
][GET_MODE (l
->elt
->val_rtx
)] != 1)
2013 for (el
= l
->elt
->locs
; el
; el
= el
->next
)
2014 if (!REG_P (el
->loc
))
2021 rtx sub
= lowpart_subreg (mode
, lwider
->elt
->val_rtx
,
2022 GET_MODE (lwider
->elt
->val_rtx
));
2024 new_elt_loc_list (e
, sub
);
2027 REG_VALUES (i
)->next
= new_elt_list (REG_VALUES (i
)->next
, e
);
2028 slot
= cselib_find_slot (x
, e
->hash
, INSERT
, memmode
);
2034 return cselib_lookup_mem (x
, create
);
2036 hashval
= cselib_hash_rtx (x
, create
, memmode
);
2037 /* Can't even create if hashing is not possible. */
2041 slot
= cselib_find_slot (wrap_constant (mode
, x
), hashval
,
2042 create
? INSERT
: NO_INSERT
, memmode
);
2046 e
= (cselib_val
*) *slot
;
2050 e
= new_cselib_val (hashval
, mode
, x
);
2052 /* We have to fill the slot before calling cselib_subst_to_values:
2053 the hash table is inconsistent until we do so, and
2054 cselib_subst_to_values will need to do lookups. */
2056 new_elt_loc_list (e
, cselib_subst_to_values (x
, memmode
));
2060 /* Wrapper for cselib_lookup, that indicates X is in INSN. */
2063 cselib_lookup_from_insn (rtx x
, enum machine_mode mode
,
2064 int create
, enum machine_mode memmode
, rtx insn
)
2068 gcc_assert (!cselib_current_insn
);
2069 cselib_current_insn
= insn
;
2071 ret
= cselib_lookup (x
, mode
, create
, memmode
);
2073 cselib_current_insn
= NULL
;
2078 /* Wrapper for cselib_lookup_1, that logs the lookup result and
2079 maintains invariants related with debug insns. */
2082 cselib_lookup (rtx x
, enum machine_mode mode
,
2083 int create
, enum machine_mode memmode
)
2085 cselib_val
*ret
= cselib_lookup_1 (x
, mode
, create
, memmode
);
2087 /* ??? Should we return NULL if we're not to create an entry, the
2088 found loc is a debug loc and cselib_current_insn is not DEBUG?
2089 If so, we should also avoid converting val to non-DEBUG; probably
2090 easiest setting cselib_current_insn to NULL before the call
2093 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
2095 fputs ("cselib lookup ", dump_file
);
2096 print_inline_rtx (dump_file
, x
, 2);
2097 fprintf (dump_file
, " => %u:%u\n",
2099 ret
? ret
->hash
: 0);
2105 /* Invalidate any entries in reg_values that overlap REGNO. This is called
2106 if REGNO is changing. MODE is the mode of the assignment to REGNO, which
2107 is used to determine how many hard registers are being changed. If MODE
2108 is VOIDmode, then only REGNO is being changed; this is used when
2109 invalidating call clobbered registers across a call. */
2112 cselib_invalidate_regno (unsigned int regno
, enum machine_mode mode
)
2114 unsigned int endregno
;
2117 /* If we see pseudos after reload, something is _wrong_. */
2118 gcc_assert (!reload_completed
|| regno
< FIRST_PSEUDO_REGISTER
2119 || reg_renumber
[regno
] < 0);
2121 /* Determine the range of registers that must be invalidated. For
2122 pseudos, only REGNO is affected. For hard regs, we must take MODE
2123 into account, and we must also invalidate lower register numbers
2124 if they contain values that overlap REGNO. */
2125 if (regno
< FIRST_PSEUDO_REGISTER
)
2127 gcc_assert (mode
!= VOIDmode
);
2129 if (regno
< max_value_regs
)
2132 i
= regno
- max_value_regs
;
2134 endregno
= end_hard_regno (mode
, regno
);
2139 endregno
= regno
+ 1;
2142 for (; i
< endregno
; i
++)
2144 struct elt_list
**l
= ®_VALUES (i
);
2146 /* Go through all known values for this reg; if it overlaps the range
2147 we're invalidating, remove the value. */
2150 cselib_val
*v
= (*l
)->elt
;
2153 struct elt_loc_list
**p
;
2154 unsigned int this_last
= i
;
2156 if (i
< FIRST_PSEUDO_REGISTER
&& v
!= NULL
)
2157 this_last
= end_hard_regno (GET_MODE (v
->val_rtx
), i
) - 1;
2159 if (this_last
< regno
|| v
== NULL
2160 || (v
== cfa_base_preserved_val
2161 && i
== cfa_base_preserved_regno
))
2167 /* We have an overlap. */
2168 if (*l
== REG_VALUES (i
))
2170 /* Maintain the invariant that the first entry of
2171 REG_VALUES, if present, must be the value used to set
2172 the register, or NULL. This is also nice because
2173 then we won't push the same regno onto user_regs
2179 unchain_one_elt_list (l
);
2181 v
= canonical_cselib_val (v
);
2183 had_locs
= v
->locs
!= NULL
;
2184 setting_insn
= v
->locs
? v
->locs
->setting_insn
: NULL
;
2186 /* Now, we clear the mapping from value to reg. It must exist, so
2187 this code will crash intentionally if it doesn't. */
2188 for (p
= &v
->locs
; ; p
= &(*p
)->next
)
2192 if (REG_P (x
) && REGNO (x
) == i
)
2194 unchain_one_elt_loc_list (p
);
2199 if (had_locs
&& v
->locs
== 0 && !PRESERVED_VALUE_P (v
->val_rtx
))
2201 if (setting_insn
&& DEBUG_INSN_P (setting_insn
))
2202 n_useless_debug_values
++;
2210 /* Invalidate any locations in the table which are changed because of a
2211 store to MEM_RTX. If this is called because of a non-const call
2212 instruction, MEM_RTX is (mem:BLK const0_rtx). */
2215 cselib_invalidate_mem (rtx mem_rtx
)
2217 cselib_val
**vp
, *v
, *next
;
2221 mem_addr
= canon_rtx (get_addr (XEXP (mem_rtx
, 0)));
2222 mem_rtx
= canon_rtx (mem_rtx
);
2224 vp
= &first_containing_mem
;
2225 for (v
= *vp
; v
!= &dummy_val
; v
= next
)
2227 bool has_mem
= false;
2228 struct elt_loc_list
**p
= &v
->locs
;
2229 bool had_locs
= v
->locs
!= NULL
;
2230 rtx setting_insn
= v
->locs
? v
->locs
->setting_insn
: NULL
;
2236 struct elt_list
**mem_chain
;
2238 /* MEMs may occur in locations only at the top level; below
2239 that every MEM or REG is substituted by its VALUE. */
2245 if (num_mems
< PARAM_VALUE (PARAM_MAX_CSELIB_MEMORY_LOCATIONS
)
2246 && ! canon_true_dependence (mem_rtx
, GET_MODE (mem_rtx
),
2247 mem_addr
, x
, NULL_RTX
))
2255 /* This one overlaps. */
2256 /* We must have a mapping from this MEM's address to the
2257 value (E). Remove that, too. */
2258 addr
= cselib_lookup (XEXP (x
, 0), VOIDmode
, 0, GET_MODE (x
));
2259 addr
= canonical_cselib_val (addr
);
2260 gcc_checking_assert (v
== canonical_cselib_val (v
));
2261 mem_chain
= &addr
->addr_list
;
2264 cselib_val
*canon
= canonical_cselib_val ((*mem_chain
)->elt
);
2268 unchain_one_elt_list (mem_chain
);
2272 /* Record canonicalized elt. */
2273 (*mem_chain
)->elt
= canon
;
2275 mem_chain
= &(*mem_chain
)->next
;
2278 unchain_one_elt_loc_list (p
);
2281 if (had_locs
&& v
->locs
== 0 && !PRESERVED_VALUE_P (v
->val_rtx
))
2283 if (setting_insn
&& DEBUG_INSN_P (setting_insn
))
2284 n_useless_debug_values
++;
2289 next
= v
->next_containing_mem
;
2293 vp
= &(*vp
)->next_containing_mem
;
2296 v
->next_containing_mem
= NULL
;
2301 /* Invalidate DEST, which is being assigned to or clobbered. */
2304 cselib_invalidate_rtx (rtx dest
)
2306 while (GET_CODE (dest
) == SUBREG
2307 || GET_CODE (dest
) == ZERO_EXTRACT
2308 || GET_CODE (dest
) == STRICT_LOW_PART
)
2309 dest
= XEXP (dest
, 0);
2312 cselib_invalidate_regno (REGNO (dest
), GET_MODE (dest
));
2313 else if (MEM_P (dest
))
2314 cselib_invalidate_mem (dest
);
2317 /* A wrapper for cselib_invalidate_rtx to be called via note_stores. */
2320 cselib_invalidate_rtx_note_stores (rtx dest
, const_rtx ignore ATTRIBUTE_UNUSED
,
2321 void *data ATTRIBUTE_UNUSED
)
2323 cselib_invalidate_rtx (dest
);
2326 /* Record the result of a SET instruction. DEST is being set; the source
2327 contains the value described by SRC_ELT. If DEST is a MEM, DEST_ADDR_ELT
2328 describes its address. */
2331 cselib_record_set (rtx dest
, cselib_val
*src_elt
, cselib_val
*dest_addr_elt
)
2333 int dreg
= REG_P (dest
) ? (int) REGNO (dest
) : -1;
2335 if (src_elt
== 0 || side_effects_p (dest
))
2340 if (dreg
< FIRST_PSEUDO_REGISTER
)
2342 unsigned int n
= hard_regno_nregs
[dreg
][GET_MODE (dest
)];
2344 if (n
> max_value_regs
)
2348 if (REG_VALUES (dreg
) == 0)
2350 used_regs
[n_used_regs
++] = dreg
;
2351 REG_VALUES (dreg
) = new_elt_list (REG_VALUES (dreg
), src_elt
);
2355 /* The register should have been invalidated. */
2356 gcc_assert (REG_VALUES (dreg
)->elt
== 0);
2357 REG_VALUES (dreg
)->elt
= src_elt
;
2360 if (src_elt
->locs
== 0 && !PRESERVED_VALUE_P (src_elt
->val_rtx
))
2362 new_elt_loc_list (src_elt
, dest
);
2364 else if (MEM_P (dest
) && dest_addr_elt
!= 0
2365 && cselib_record_memory
)
2367 if (src_elt
->locs
== 0 && !PRESERVED_VALUE_P (src_elt
->val_rtx
))
2369 add_mem_for_addr (dest_addr_elt
, src_elt
, dest
);
2373 /* Make ELT and X's VALUE equivalent to each other at INSN. */
2376 cselib_add_permanent_equiv (cselib_val
*elt
, rtx x
, rtx insn
)
2379 rtx save_cselib_current_insn
= cselib_current_insn
;
2381 gcc_checking_assert (elt
);
2382 gcc_checking_assert (PRESERVED_VALUE_P (elt
->val_rtx
));
2383 gcc_checking_assert (!side_effects_p (x
));
2385 cselib_current_insn
= insn
;
2387 nelt
= cselib_lookup (x
, GET_MODE (elt
->val_rtx
), 1, VOIDmode
);
2391 if (!PRESERVED_VALUE_P (nelt
->val_rtx
))
2392 cselib_preserve_value (nelt
);
2394 new_elt_loc_list (nelt
, elt
->val_rtx
);
2397 cselib_current_insn
= save_cselib_current_insn
;
2400 /* There is no good way to determine how many elements there can be
2401 in a PARALLEL. Since it's fairly cheap, use a really large number. */
2402 #define MAX_SETS (FIRST_PSEUDO_REGISTER * 2)
2404 struct cselib_record_autoinc_data
2406 struct cselib_set
*sets
;
2410 /* Callback for for_each_inc_dec. Records in ARG the SETs implied by
2411 autoinc RTXs: SRC plus SRCOFF if non-NULL is stored in DEST. */
2414 cselib_record_autoinc_cb (rtx mem ATTRIBUTE_UNUSED
, rtx op ATTRIBUTE_UNUSED
,
2415 rtx dest
, rtx src
, rtx srcoff
, void *arg
)
2417 struct cselib_record_autoinc_data
*data
;
2418 data
= (struct cselib_record_autoinc_data
*)arg
;
2420 data
->sets
[data
->n_sets
].dest
= dest
;
2423 data
->sets
[data
->n_sets
].src
= gen_rtx_PLUS (GET_MODE (src
), src
, srcoff
);
2425 data
->sets
[data
->n_sets
].src
= src
;
2432 /* Record the effects of any sets and autoincs in INSN. */
2434 cselib_record_sets (rtx insn
)
2438 struct cselib_set sets
[MAX_SETS
];
2439 rtx body
= PATTERN (insn
);
2441 int n_sets_before_autoinc
;
2442 struct cselib_record_autoinc_data data
;
2444 body
= PATTERN (insn
);
2445 if (GET_CODE (body
) == COND_EXEC
)
2447 cond
= COND_EXEC_TEST (body
);
2448 body
= COND_EXEC_CODE (body
);
2451 /* Find all sets. */
2452 if (GET_CODE (body
) == SET
)
2454 sets
[0].src
= SET_SRC (body
);
2455 sets
[0].dest
= SET_DEST (body
);
2458 else if (GET_CODE (body
) == PARALLEL
)
2460 /* Look through the PARALLEL and record the values being
2461 set, if possible. Also handle any CLOBBERs. */
2462 for (i
= XVECLEN (body
, 0) - 1; i
>= 0; --i
)
2464 rtx x
= XVECEXP (body
, 0, i
);
2466 if (GET_CODE (x
) == SET
)
2468 sets
[n_sets
].src
= SET_SRC (x
);
2469 sets
[n_sets
].dest
= SET_DEST (x
);
2476 && MEM_P (sets
[0].src
)
2477 && !cselib_record_memory
2478 && MEM_READONLY_P (sets
[0].src
))
2480 rtx note
= find_reg_equal_equiv_note (insn
);
2482 if (note
&& CONSTANT_P (XEXP (note
, 0)))
2483 sets
[0].src
= XEXP (note
, 0);
2487 data
.n_sets
= n_sets_before_autoinc
= n_sets
;
2488 for_each_inc_dec (&insn
, cselib_record_autoinc_cb
, &data
);
2489 n_sets
= data
.n_sets
;
2491 /* Look up the values that are read. Do this before invalidating the
2492 locations that are written. */
2493 for (i
= 0; i
< n_sets
; i
++)
2495 rtx dest
= sets
[i
].dest
;
2497 /* A STRICT_LOW_PART can be ignored; we'll record the equivalence for
2498 the low part after invalidating any knowledge about larger modes. */
2499 if (GET_CODE (sets
[i
].dest
) == STRICT_LOW_PART
)
2500 sets
[i
].dest
= dest
= XEXP (dest
, 0);
2502 /* We don't know how to record anything but REG or MEM. */
2504 || (MEM_P (dest
) && cselib_record_memory
))
2506 rtx src
= sets
[i
].src
;
2508 src
= gen_rtx_IF_THEN_ELSE (GET_MODE (dest
), cond
, src
, dest
);
2509 sets
[i
].src_elt
= cselib_lookup (src
, GET_MODE (dest
), 1, VOIDmode
);
2512 enum machine_mode address_mode
2513 = targetm
.addr_space
.address_mode (MEM_ADDR_SPACE (dest
));
2515 sets
[i
].dest_addr_elt
= cselib_lookup (XEXP (dest
, 0),
2520 sets
[i
].dest_addr_elt
= 0;
2524 if (cselib_record_sets_hook
)
2525 cselib_record_sets_hook (insn
, sets
, n_sets
);
2527 /* Invalidate all locations written by this insn. Note that the elts we
2528 looked up in the previous loop aren't affected, just some of their
2529 locations may go away. */
2530 note_stores (body
, cselib_invalidate_rtx_note_stores
, NULL
);
2532 for (i
= n_sets_before_autoinc
; i
< n_sets
; i
++)
2533 cselib_invalidate_rtx (sets
[i
].dest
);
2535 /* If this is an asm, look for duplicate sets. This can happen when the
2536 user uses the same value as an output multiple times. This is valid
2537 if the outputs are not actually used thereafter. Treat this case as
2538 if the value isn't actually set. We do this by smashing the destination
2539 to pc_rtx, so that we won't record the value later. */
2540 if (n_sets
>= 2 && asm_noperands (body
) >= 0)
2542 for (i
= 0; i
< n_sets
; i
++)
2544 rtx dest
= sets
[i
].dest
;
2545 if (REG_P (dest
) || MEM_P (dest
))
2548 for (j
= i
+ 1; j
< n_sets
; j
++)
2549 if (rtx_equal_p (dest
, sets
[j
].dest
))
2551 sets
[i
].dest
= pc_rtx
;
2552 sets
[j
].dest
= pc_rtx
;
2558 /* Now enter the equivalences in our tables. */
2559 for (i
= 0; i
< n_sets
; i
++)
2561 rtx dest
= sets
[i
].dest
;
2563 || (MEM_P (dest
) && cselib_record_memory
))
2564 cselib_record_set (dest
, sets
[i
].src_elt
, sets
[i
].dest_addr_elt
);
2568 /* Record the effects of INSN. */
2571 cselib_process_insn (rtx insn
)
2576 cselib_current_insn
= insn
;
2578 /* Forget everything at a CODE_LABEL, a volatile asm, or a setjmp. */
2581 && find_reg_note (insn
, REG_SETJMP
, NULL
))
2582 || (NONJUMP_INSN_P (insn
)
2583 && GET_CODE (PATTERN (insn
)) == ASM_OPERANDS
2584 && MEM_VOLATILE_P (PATTERN (insn
))))
2586 cselib_reset_table (next_uid
);
2587 cselib_current_insn
= NULL_RTX
;
2591 if (! INSN_P (insn
))
2593 cselib_current_insn
= NULL_RTX
;
2597 /* If this is a call instruction, forget anything stored in a
2598 call clobbered register, or, if this is not a const call, in
2602 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; i
++)
2603 if (call_used_regs
[i
]
2604 || (REG_VALUES (i
) && REG_VALUES (i
)->elt
2605 && HARD_REGNO_CALL_PART_CLOBBERED (i
,
2606 GET_MODE (REG_VALUES (i
)->elt
->val_rtx
))))
2607 cselib_invalidate_regno (i
, reg_raw_mode
[i
]);
2609 /* Since it is not clear how cselib is going to be used, be
2610 conservative here and treat looping pure or const functions
2611 as if they were regular functions. */
2612 if (RTL_LOOPING_CONST_OR_PURE_CALL_P (insn
)
2613 || !(RTL_CONST_OR_PURE_CALL_P (insn
)))
2614 cselib_invalidate_mem (callmem
);
2617 cselib_record_sets (insn
);
2619 /* Look for any CLOBBERs in CALL_INSN_FUNCTION_USAGE, but only
2620 after we have processed the insn. */
2622 for (x
= CALL_INSN_FUNCTION_USAGE (insn
); x
; x
= XEXP (x
, 1))
2623 if (GET_CODE (XEXP (x
, 0)) == CLOBBER
)
2624 cselib_invalidate_rtx (XEXP (XEXP (x
, 0), 0));
2626 cselib_current_insn
= NULL_RTX
;
2628 if (n_useless_values
> MAX_USELESS_VALUES
2629 /* remove_useless_values is linear in the hash table size. Avoid
2630 quadratic behavior for very large hashtables with very few
2631 useless elements. */
2632 && ((unsigned int)n_useless_values
2633 > (cselib_hash_table
->n_elements
2634 - cselib_hash_table
->n_deleted
2635 - n_debug_values
) / 4))
2636 remove_useless_values ();
2639 /* Initialize cselib for one pass. The caller must also call
2640 init_alias_analysis. */
2643 cselib_init (int record_what
)
2645 elt_list_pool
= create_alloc_pool ("elt_list",
2646 sizeof (struct elt_list
), 10);
2647 elt_loc_list_pool
= create_alloc_pool ("elt_loc_list",
2648 sizeof (struct elt_loc_list
), 10);
2649 cselib_val_pool
= create_alloc_pool ("cselib_val_list",
2650 sizeof (cselib_val
), 10);
2651 value_pool
= create_alloc_pool ("value", RTX_CODE_SIZE (VALUE
), 100);
2652 cselib_record_memory
= record_what
& CSELIB_RECORD_MEMORY
;
2653 cselib_preserve_constants
= record_what
& CSELIB_PRESERVE_CONSTANTS
;
2655 /* (mem:BLK (scratch)) is a special mechanism to conflict with everything,
2656 see canon_true_dependence. This is only created once. */
2658 callmem
= gen_rtx_MEM (BLKmode
, gen_rtx_SCRATCH (VOIDmode
));
2660 cselib_nregs
= max_reg_num ();
2662 /* We preserve reg_values to allow expensive clearing of the whole thing.
2663 Reallocate it however if it happens to be too large. */
2664 if (!reg_values
|| reg_values_size
< cselib_nregs
2665 || (reg_values_size
> 10 && reg_values_size
> cselib_nregs
* 4))
2668 /* Some space for newly emit instructions so we don't end up
2669 reallocating in between passes. */
2670 reg_values_size
= cselib_nregs
+ (63 + cselib_nregs
) / 16;
2671 reg_values
= XCNEWVEC (struct elt_list
*, reg_values_size
);
2673 used_regs
= XNEWVEC (unsigned int, cselib_nregs
);
2675 cselib_hash_table
= htab_create (31, get_value_hash
,
2676 entry_and_rtx_equal_p
, NULL
);
2680 /* Called when the current user is done with cselib. */
2683 cselib_finish (void)
2685 cselib_discard_hook
= NULL
;
2686 cselib_preserve_constants
= false;
2687 cfa_base_preserved_val
= NULL
;
2688 cfa_base_preserved_regno
= INVALID_REGNUM
;
2689 free_alloc_pool (elt_list_pool
);
2690 free_alloc_pool (elt_loc_list_pool
);
2691 free_alloc_pool (cselib_val_pool
);
2692 free_alloc_pool (value_pool
);
2693 cselib_clear_table ();
2694 htab_delete (cselib_hash_table
);
2697 cselib_hash_table
= 0;
2698 n_useless_values
= 0;
2699 n_useless_debug_values
= 0;
2704 /* Dump the cselib_val *X to FILE *info. */
2707 dump_cselib_val (void **x
, void *info
)
2709 cselib_val
*v
= (cselib_val
*)*x
;
2710 FILE *out
= (FILE *)info
;
2711 bool need_lf
= true;
2713 print_inline_rtx (out
, v
->val_rtx
, 0);
2717 struct elt_loc_list
*l
= v
->locs
;
2723 fputs (" locs:", out
);
2726 if (l
->setting_insn
)
2727 fprintf (out
, "\n from insn %i ",
2728 INSN_UID (l
->setting_insn
));
2730 fprintf (out
, "\n ");
2731 print_inline_rtx (out
, l
->loc
, 4);
2733 while ((l
= l
->next
));
2738 fputs (" no locs", out
);
2744 struct elt_list
*e
= v
->addr_list
;
2750 fputs (" addr list:", out
);
2754 print_inline_rtx (out
, e
->elt
->val_rtx
, 2);
2756 while ((e
= e
->next
));
2761 fputs (" no addrs", out
);
2765 if (v
->next_containing_mem
== &dummy_val
)
2766 fputs (" last mem\n", out
);
2767 else if (v
->next_containing_mem
)
2769 fputs (" next mem ", out
);
2770 print_inline_rtx (out
, v
->next_containing_mem
->val_rtx
, 2);
2779 /* Dump to OUT everything in the CSELIB table. */
2782 dump_cselib_table (FILE *out
)
2784 fprintf (out
, "cselib hash table:\n");
2785 htab_traverse (cselib_hash_table
, dump_cselib_val
, out
);
2786 if (first_containing_mem
!= &dummy_val
)
2788 fputs ("first mem ", out
);
2789 print_inline_rtx (out
, first_containing_mem
->val_rtx
, 2);
2792 fprintf (out
, "next uid %i\n", next_uid
);
2795 #include "gt-cselib.h"