1 /* Common subexpression elimination library for GNU compiler.
2 Copyright (C) 1987-2018 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
22 #include "coretypes.h"
36 /* A list of cselib_val structures. */
39 struct elt_list
*next
;
43 static bool cselib_record_memory
;
44 static bool cselib_preserve_constants
;
45 static bool cselib_any_perm_equivs
;
46 static inline void promote_debug_loc (struct elt_loc_list
*l
);
47 static struct elt_list
*new_elt_list (struct elt_list
*, cselib_val
*);
48 static void new_elt_loc_list (cselib_val
*, rtx
);
49 static void unchain_one_value (cselib_val
*);
50 static void unchain_one_elt_list (struct elt_list
**);
51 static void unchain_one_elt_loc_list (struct elt_loc_list
**);
52 static void remove_useless_values (void);
53 static unsigned int cselib_hash_rtx (rtx
, int, machine_mode
);
54 static cselib_val
*new_cselib_val (unsigned int, machine_mode
, rtx
);
55 static void add_mem_for_addr (cselib_val
*, cselib_val
*, rtx
);
56 static cselib_val
*cselib_lookup_mem (rtx
, int);
57 static void cselib_invalidate_regno (unsigned int, machine_mode
);
58 static void cselib_invalidate_mem (rtx
);
59 static void cselib_record_set (rtx
, cselib_val
*, cselib_val
*);
60 static void cselib_record_sets (rtx_insn
*);
62 struct expand_value_data
65 cselib_expand_callback callback
;
70 static rtx
cselib_expand_value_rtx_1 (rtx
, struct expand_value_data
*, int);
72 /* There are three ways in which cselib can look up an rtx:
73 - for a REG, the reg_values table (which is indexed by regno) is used
74 - for a MEM, we recursively look up its address and then follow the
75 addr_list of that value
76 - for everything else, we compute a hash value and go through the hash
77 table. Since different rtx's can still have the same hash value,
78 this involves walking the table entries for a given value and comparing
79 the locations of the entries with the rtx we are looking up. */
81 struct cselib_hasher
: nofree_ptr_hash
<cselib_val
>
84 /* The rtx value and its mode (needed separately for constant
88 /* The mode of the contaning MEM, if any, otherwise VOIDmode. */
91 typedef key
*compare_type
;
92 static inline hashval_t
hash (const cselib_val
*);
93 static inline bool equal (const cselib_val
*, const key
*);
96 /* The hash function for our hash table. The value is always computed with
97 cselib_hash_rtx when adding an element; this function just extracts the
98 hash value from a cselib_val structure. */
101 cselib_hasher::hash (const cselib_val
*v
)
106 /* The equality test for our hash table. The first argument V is a table
107 element (i.e. a cselib_val), while the second arg X is an rtx. We know
108 that all callers of htab_find_slot_with_hash will wrap CONST_INTs into a
109 CONST of an appropriate mode. */
112 cselib_hasher::equal (const cselib_val
*v
, const key
*x_arg
)
114 struct elt_loc_list
*l
;
116 machine_mode mode
= x_arg
->mode
;
117 machine_mode memmode
= x_arg
->memmode
;
119 if (mode
!= GET_MODE (v
->val_rtx
))
122 if (GET_CODE (x
) == VALUE
)
123 return x
== v
->val_rtx
;
125 /* We don't guarantee that distinct rtx's have different hash values,
126 so we need to do a comparison. */
127 for (l
= v
->locs
; l
; l
= l
->next
)
128 if (rtx_equal_for_cselib_1 (l
->loc
, x
, memmode
, 0))
130 promote_debug_loc (l
);
137 /* A table that enables us to look up elts by their value. */
138 static hash_table
<cselib_hasher
> *cselib_hash_table
;
140 /* A table to hold preserved values. */
141 static hash_table
<cselib_hasher
> *cselib_preserved_hash_table
;
143 /* This is a global so we don't have to pass this through every function.
144 It is used in new_elt_loc_list to set SETTING_INSN. */
145 static rtx_insn
*cselib_current_insn
;
147 /* The unique id that the next create value will take. */
148 static unsigned int next_uid
;
150 /* The number of registers we had when the varrays were last resized. */
151 static unsigned int cselib_nregs
;
153 /* Count values without known locations, or with only locations that
154 wouldn't have been known except for debug insns. Whenever this
155 grows too big, we remove these useless values from the table.
157 Counting values with only debug values is a bit tricky. We don't
158 want to increment n_useless_values when we create a value for a
159 debug insn, for this would get n_useless_values out of sync, but we
160 want increment it if all locs in the list that were ever referenced
161 in nondebug insns are removed from the list.
163 In the general case, once we do that, we'd have to stop accepting
164 nondebug expressions in the loc list, to avoid having two values
165 equivalent that, without debug insns, would have been made into
166 separate values. However, because debug insns never introduce
167 equivalences themselves (no assignments), the only means for
168 growing loc lists is through nondebug assignments. If the locs
169 also happen to be referenced in debug insns, it will work just fine.
171 A consequence of this is that there's at most one debug-only loc in
172 each loc list. If we keep it in the first entry, testing whether
173 we have a debug-only loc list takes O(1).
175 Furthermore, since any additional entry in a loc list containing a
176 debug loc would have to come from an assignment (nondebug) that
177 references both the initial debug loc and the newly-equivalent loc,
178 the initial debug loc would be promoted to a nondebug loc, and the
179 loc list would not contain debug locs any more.
181 So the only case we have to be careful with in order to keep
182 n_useless_values in sync between debug and nondebug compilations is
183 to avoid incrementing n_useless_values when removing the single loc
184 from a value that turns out to not appear outside debug values. We
185 increment n_useless_debug_values instead, and leave such values
186 alone until, for other reasons, we garbage-collect useless
188 static int n_useless_values
;
189 static int n_useless_debug_values
;
191 /* Count values whose locs have been taken exclusively from debug
192 insns for the entire life of the value. */
193 static int n_debug_values
;
195 /* Number of useless values before we remove them from the hash table. */
196 #define MAX_USELESS_VALUES 32
198 /* This table maps from register number to values. It does not
199 contain pointers to cselib_val structures, but rather elt_lists.
200 The purpose is to be able to refer to the same register in
201 different modes. The first element of the list defines the mode in
202 which the register was set; if the mode is unknown or the value is
203 no longer valid in that mode, ELT will be NULL for the first
205 static struct elt_list
**reg_values
;
206 static unsigned int reg_values_size
;
207 #define REG_VALUES(i) reg_values[i]
209 /* The largest number of hard regs used by any entry added to the
210 REG_VALUES table. Cleared on each cselib_clear_table() invocation. */
211 static unsigned int max_value_regs
;
213 /* Here the set of indices I with REG_VALUES(I) != 0 is saved. This is used
214 in cselib_clear_table() for fast emptying. */
215 static unsigned int *used_regs
;
216 static unsigned int n_used_regs
;
218 /* We pass this to cselib_invalidate_mem to invalidate all of
219 memory for a non-const call instruction. */
220 static GTY(()) rtx callmem
;
222 /* Set by discard_useless_locs if it deleted the last location of any
224 static int values_became_useless
;
226 /* Used as stop element of the containing_mem list so we can check
227 presence in the list by checking the next pointer. */
228 static cselib_val dummy_val
;
230 /* If non-NULL, value of the eliminated arg_pointer_rtx or frame_pointer_rtx
231 that is constant through the whole function and should never be
233 static cselib_val
*cfa_base_preserved_val
;
234 static unsigned int cfa_base_preserved_regno
= INVALID_REGNUM
;
236 /* Used to list all values that contain memory reference.
237 May or may not contain the useless values - the list is compacted
238 each time memory is invalidated. */
239 static cselib_val
*first_containing_mem
= &dummy_val
;
241 static object_allocator
<elt_list
> elt_list_pool ("elt_list");
242 static object_allocator
<elt_loc_list
> elt_loc_list_pool ("elt_loc_list");
243 static object_allocator
<cselib_val
> cselib_val_pool ("cselib_val_list");
245 static pool_allocator
value_pool ("value", RTX_CODE_SIZE (VALUE
));
247 /* If nonnull, cselib will call this function before freeing useless
248 VALUEs. A VALUE is deemed useless if its "locs" field is null. */
249 void (*cselib_discard_hook
) (cselib_val
*);
251 /* If nonnull, cselib will call this function before recording sets or
252 even clobbering outputs of INSN. All the recorded sets will be
253 represented in the array sets[n_sets]. new_val_min can be used to
254 tell whether values present in sets are introduced by this
256 void (*cselib_record_sets_hook
) (rtx_insn
*insn
, struct cselib_set
*sets
,
259 #define PRESERVED_VALUE_P(RTX) \
260 (RTL_FLAG_CHECK1 ("PRESERVED_VALUE_P", (RTX), VALUE)->unchanging)
262 #define SP_BASED_VALUE_P(RTX) \
263 (RTL_FLAG_CHECK1 ("SP_BASED_VALUE_P", (RTX), VALUE)->jump)
267 /* Allocate a struct elt_list and fill in its two elements with the
270 static inline struct elt_list
*
271 new_elt_list (struct elt_list
*next
, cselib_val
*elt
)
273 elt_list
*el
= elt_list_pool
.allocate ();
279 /* Allocate a struct elt_loc_list with LOC and prepend it to VAL's loc
283 new_elt_loc_list (cselib_val
*val
, rtx loc
)
285 struct elt_loc_list
*el
, *next
= val
->locs
;
287 gcc_checking_assert (!next
|| !next
->setting_insn
288 || !DEBUG_INSN_P (next
->setting_insn
)
289 || cselib_current_insn
== next
->setting_insn
);
291 /* If we're creating the first loc in a debug insn context, we've
292 just created a debug value. Count it. */
293 if (!next
&& cselib_current_insn
&& DEBUG_INSN_P (cselib_current_insn
))
296 val
= canonical_cselib_val (val
);
299 if (GET_CODE (loc
) == VALUE
)
301 loc
= canonical_cselib_val (CSELIB_VAL_PTR (loc
))->val_rtx
;
303 gcc_checking_assert (PRESERVED_VALUE_P (loc
)
304 == PRESERVED_VALUE_P (val
->val_rtx
));
306 if (val
->val_rtx
== loc
)
308 else if (val
->uid
> CSELIB_VAL_PTR (loc
)->uid
)
310 /* Reverse the insertion. */
311 new_elt_loc_list (CSELIB_VAL_PTR (loc
), val
->val_rtx
);
315 gcc_checking_assert (val
->uid
< CSELIB_VAL_PTR (loc
)->uid
);
317 if (CSELIB_VAL_PTR (loc
)->locs
)
319 /* Bring all locs from LOC to VAL. */
320 for (el
= CSELIB_VAL_PTR (loc
)->locs
; el
->next
; el
= el
->next
)
322 /* Adjust values that have LOC as canonical so that VAL
323 becomes their canonical. */
324 if (el
->loc
&& GET_CODE (el
->loc
) == VALUE
)
326 gcc_checking_assert (CSELIB_VAL_PTR (el
->loc
)->locs
->loc
328 CSELIB_VAL_PTR (el
->loc
)->locs
->loc
= val
->val_rtx
;
331 el
->next
= val
->locs
;
332 next
= val
->locs
= CSELIB_VAL_PTR (loc
)->locs
;
335 if (CSELIB_VAL_PTR (loc
)->addr_list
)
337 /* Bring in addr_list into canonical node. */
338 struct elt_list
*last
= CSELIB_VAL_PTR (loc
)->addr_list
;
341 last
->next
= val
->addr_list
;
342 val
->addr_list
= CSELIB_VAL_PTR (loc
)->addr_list
;
343 CSELIB_VAL_PTR (loc
)->addr_list
= NULL
;
346 if (CSELIB_VAL_PTR (loc
)->next_containing_mem
!= NULL
347 && val
->next_containing_mem
== NULL
)
349 /* Add VAL to the containing_mem list after LOC. LOC will
350 be removed when we notice it doesn't contain any
352 val
->next_containing_mem
= CSELIB_VAL_PTR (loc
)->next_containing_mem
;
353 CSELIB_VAL_PTR (loc
)->next_containing_mem
= val
;
356 /* Chain LOC back to VAL. */
357 el
= elt_loc_list_pool
.allocate ();
358 el
->loc
= val
->val_rtx
;
359 el
->setting_insn
= cselib_current_insn
;
361 CSELIB_VAL_PTR (loc
)->locs
= el
;
364 el
= elt_loc_list_pool
.allocate ();
366 el
->setting_insn
= cselib_current_insn
;
371 /* Promote loc L to a nondebug cselib_current_insn if L is marked as
372 originating from a debug insn, maintaining the debug values
376 promote_debug_loc (struct elt_loc_list
*l
)
378 if (l
&& l
->setting_insn
&& DEBUG_INSN_P (l
->setting_insn
)
379 && (!cselib_current_insn
|| !DEBUG_INSN_P (cselib_current_insn
)))
382 l
->setting_insn
= cselib_current_insn
;
383 if (cselib_preserve_constants
&& l
->next
)
385 gcc_assert (l
->next
->setting_insn
386 && DEBUG_INSN_P (l
->next
->setting_insn
)
388 l
->next
->setting_insn
= cselib_current_insn
;
391 gcc_assert (!l
->next
);
395 /* The elt_list at *PL is no longer needed. Unchain it and free its
399 unchain_one_elt_list (struct elt_list
**pl
)
401 struct elt_list
*l
= *pl
;
404 elt_list_pool
.remove (l
);
407 /* Likewise for elt_loc_lists. */
410 unchain_one_elt_loc_list (struct elt_loc_list
**pl
)
412 struct elt_loc_list
*l
= *pl
;
415 elt_loc_list_pool
.remove (l
);
418 /* Likewise for cselib_vals. This also frees the addr_list associated with
422 unchain_one_value (cselib_val
*v
)
425 unchain_one_elt_list (&v
->addr_list
);
427 cselib_val_pool
.remove (v
);
430 /* Remove all entries from the hash table. Also used during
434 cselib_clear_table (void)
436 cselib_reset_table (1);
439 /* Return TRUE if V is a constant, a function invariant or a VALUE
440 equivalence; FALSE otherwise. */
443 invariant_or_equiv_p (cselib_val
*v
)
445 struct elt_loc_list
*l
;
447 if (v
== cfa_base_preserved_val
)
450 /* Keep VALUE equivalences around. */
451 for (l
= v
->locs
; l
; l
= l
->next
)
452 if (GET_CODE (l
->loc
) == VALUE
)
456 && v
->locs
->next
== NULL
)
458 if (CONSTANT_P (v
->locs
->loc
)
459 && (GET_CODE (v
->locs
->loc
) != CONST
460 || !references_value_p (v
->locs
->loc
, 0)))
462 /* Although a debug expr may be bound to different expressions,
463 we can preserve it as if it was constant, to get unification
464 and proper merging within var-tracking. */
465 if (GET_CODE (v
->locs
->loc
) == DEBUG_EXPR
466 || GET_CODE (v
->locs
->loc
) == DEBUG_IMPLICIT_PTR
467 || GET_CODE (v
->locs
->loc
) == ENTRY_VALUE
468 || GET_CODE (v
->locs
->loc
) == DEBUG_PARAMETER_REF
)
471 /* (plus (value V) (const_int C)) is invariant iff V is invariant. */
472 if (GET_CODE (v
->locs
->loc
) == PLUS
473 && CONST_INT_P (XEXP (v
->locs
->loc
, 1))
474 && GET_CODE (XEXP (v
->locs
->loc
, 0)) == VALUE
475 && invariant_or_equiv_p (CSELIB_VAL_PTR (XEXP (v
->locs
->loc
, 0))))
482 /* Remove from hash table all VALUEs except constants, function
483 invariants and VALUE equivalences. */
486 preserve_constants_and_equivs (cselib_val
**x
, void *info ATTRIBUTE_UNUSED
)
490 if (invariant_or_equiv_p (v
))
492 cselib_hasher::key lookup
= {
493 GET_MODE (v
->val_rtx
), v
->val_rtx
, VOIDmode
496 = cselib_preserved_hash_table
->find_slot_with_hash (&lookup
,
502 cselib_hash_table
->clear_slot (x
);
507 /* Remove all entries from the hash table, arranging for the next
508 value to be numbered NUM. */
511 cselib_reset_table (unsigned int num
)
517 if (cfa_base_preserved_val
)
519 unsigned int regno
= cfa_base_preserved_regno
;
520 unsigned int new_used_regs
= 0;
521 for (i
= 0; i
< n_used_regs
; i
++)
522 if (used_regs
[i
] == regno
)
528 REG_VALUES (used_regs
[i
]) = 0;
529 gcc_assert (new_used_regs
== 1);
530 n_used_regs
= new_used_regs
;
531 used_regs
[0] = regno
;
533 = hard_regno_nregs (regno
,
534 GET_MODE (cfa_base_preserved_val
->locs
->loc
));
538 for (i
= 0; i
< n_used_regs
; i
++)
539 REG_VALUES (used_regs
[i
]) = 0;
543 if (cselib_preserve_constants
)
544 cselib_hash_table
->traverse
<void *, preserve_constants_and_equivs
>
548 cselib_hash_table
->empty ();
549 gcc_checking_assert (!cselib_any_perm_equivs
);
552 n_useless_values
= 0;
553 n_useless_debug_values
= 0;
558 first_containing_mem
= &dummy_val
;
561 /* Return the number of the next value that will be generated. */
564 cselib_get_next_uid (void)
569 /* Search for X, whose hashcode is HASH, in CSELIB_HASH_TABLE,
570 INSERTing if requested. When X is part of the address of a MEM,
571 MEMMODE should specify the mode of the MEM. */
574 cselib_find_slot (machine_mode mode
, rtx x
, hashval_t hash
,
575 enum insert_option insert
, machine_mode memmode
)
577 cselib_val
**slot
= NULL
;
578 cselib_hasher::key lookup
= { mode
, x
, memmode
};
579 if (cselib_preserve_constants
)
580 slot
= cselib_preserved_hash_table
->find_slot_with_hash (&lookup
, hash
,
583 slot
= cselib_hash_table
->find_slot_with_hash (&lookup
, hash
, insert
);
587 /* Return true if X contains a VALUE rtx. If ONLY_USELESS is set, we
588 only return true for values which point to a cselib_val whose value
589 element has been set to zero, which implies the cselib_val will be
593 references_value_p (const_rtx x
, int only_useless
)
595 const enum rtx_code code
= GET_CODE (x
);
596 const char *fmt
= GET_RTX_FORMAT (code
);
599 if (GET_CODE (x
) == VALUE
600 && (! only_useless
||
601 (CSELIB_VAL_PTR (x
)->locs
== 0 && !PRESERVED_VALUE_P (x
))))
604 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
606 if (fmt
[i
] == 'e' && references_value_p (XEXP (x
, i
), only_useless
))
608 else if (fmt
[i
] == 'E')
609 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
610 if (references_value_p (XVECEXP (x
, i
, j
), only_useless
))
617 /* For all locations found in X, delete locations that reference useless
618 values (i.e. values without any location). Called through
622 discard_useless_locs (cselib_val
**x
, void *info ATTRIBUTE_UNUSED
)
625 struct elt_loc_list
**p
= &v
->locs
;
626 bool had_locs
= v
->locs
!= NULL
;
627 rtx_insn
*setting_insn
= v
->locs
? v
->locs
->setting_insn
: NULL
;
631 if (references_value_p ((*p
)->loc
, 1))
632 unchain_one_elt_loc_list (p
);
637 if (had_locs
&& v
->locs
== 0 && !PRESERVED_VALUE_P (v
->val_rtx
))
639 if (setting_insn
&& DEBUG_INSN_P (setting_insn
))
640 n_useless_debug_values
++;
643 values_became_useless
= 1;
648 /* If X is a value with no locations, remove it from the hashtable. */
651 discard_useless_values (cselib_val
**x
, void *info ATTRIBUTE_UNUSED
)
655 if (v
->locs
== 0 && !PRESERVED_VALUE_P (v
->val_rtx
))
657 if (cselib_discard_hook
)
658 cselib_discard_hook (v
);
660 CSELIB_VAL_PTR (v
->val_rtx
) = NULL
;
661 cselib_hash_table
->clear_slot (x
);
662 unchain_one_value (v
);
669 /* Clean out useless values (i.e. those which no longer have locations
670 associated with them) from the hash table. */
673 remove_useless_values (void)
677 /* First pass: eliminate locations that reference the value. That in
678 turn can make more values useless. */
681 values_became_useless
= 0;
682 cselib_hash_table
->traverse
<void *, discard_useless_locs
> (NULL
);
684 while (values_became_useless
);
686 /* Second pass: actually remove the values. */
688 p
= &first_containing_mem
;
689 for (v
= *p
; v
!= &dummy_val
; v
= v
->next_containing_mem
)
690 if (v
->locs
&& v
== canonical_cselib_val (v
))
693 p
= &(*p
)->next_containing_mem
;
697 n_useless_values
+= n_useless_debug_values
;
698 n_debug_values
-= n_useless_debug_values
;
699 n_useless_debug_values
= 0;
701 cselib_hash_table
->traverse
<void *, discard_useless_values
> (NULL
);
703 gcc_assert (!n_useless_values
);
706 /* Arrange for a value to not be removed from the hash table even if
707 it becomes useless. */
710 cselib_preserve_value (cselib_val
*v
)
712 PRESERVED_VALUE_P (v
->val_rtx
) = 1;
715 /* Test whether a value is preserved. */
718 cselib_preserved_value_p (cselib_val
*v
)
720 return PRESERVED_VALUE_P (v
->val_rtx
);
723 /* Arrange for a REG value to be assumed constant through the whole function,
724 never invalidated and preserved across cselib_reset_table calls. */
727 cselib_preserve_cfa_base_value (cselib_val
*v
, unsigned int regno
)
729 if (cselib_preserve_constants
731 && REG_P (v
->locs
->loc
))
733 cfa_base_preserved_val
= v
;
734 cfa_base_preserved_regno
= regno
;
738 /* Clean all non-constant expressions in the hash table, but retain
742 cselib_preserve_only_values (void)
746 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; i
++)
747 cselib_invalidate_regno (i
, reg_raw_mode
[i
]);
749 cselib_invalidate_mem (callmem
);
751 remove_useless_values ();
753 gcc_assert (first_containing_mem
== &dummy_val
);
756 /* Arrange for a value to be marked as based on stack pointer
757 for find_base_term purposes. */
760 cselib_set_value_sp_based (cselib_val
*v
)
762 SP_BASED_VALUE_P (v
->val_rtx
) = 1;
765 /* Test whether a value is based on stack pointer for
766 find_base_term purposes. */
769 cselib_sp_based_value_p (cselib_val
*v
)
771 return SP_BASED_VALUE_P (v
->val_rtx
);
774 /* Return the mode in which a register was last set. If X is not a
775 register, return its mode. If the mode in which the register was
776 set is not known, or the value was already clobbered, return
780 cselib_reg_set_mode (const_rtx x
)
785 if (REG_VALUES (REGNO (x
)) == NULL
786 || REG_VALUES (REGNO (x
))->elt
== NULL
)
789 return GET_MODE (REG_VALUES (REGNO (x
))->elt
->val_rtx
);
792 /* If x is a PLUS or an autoinc operation, expand the operation,
793 storing the offset, if any, in *OFF. */
796 autoinc_split (rtx x
, rtx
*off
, machine_mode memmode
)
798 switch (GET_CODE (x
))
805 if (memmode
== VOIDmode
)
808 *off
= GEN_INT (-GET_MODE_SIZE (memmode
));
812 if (memmode
== VOIDmode
)
815 *off
= GEN_INT (GET_MODE_SIZE (memmode
));
831 /* Return nonzero if we can prove that X and Y contain the same value,
832 taking our gathered information into account. MEMMODE holds the
833 mode of the enclosing MEM, if any, as required to deal with autoinc
834 addressing modes. If X and Y are not (known to be) part of
835 addresses, MEMMODE should be VOIDmode. */
838 rtx_equal_for_cselib_1 (rtx x
, rtx y
, machine_mode memmode
, int depth
)
844 if (REG_P (x
) || MEM_P (x
))
846 cselib_val
*e
= cselib_lookup (x
, GET_MODE (x
), 0, memmode
);
852 if (REG_P (y
) || MEM_P (y
))
854 cselib_val
*e
= cselib_lookup (y
, GET_MODE (y
), 0, memmode
);
863 if (GET_CODE (x
) == VALUE
)
865 cselib_val
*e
= canonical_cselib_val (CSELIB_VAL_PTR (x
));
866 struct elt_loc_list
*l
;
868 if (GET_CODE (y
) == VALUE
)
869 return e
== canonical_cselib_val (CSELIB_VAL_PTR (y
));
874 for (l
= e
->locs
; l
; l
= l
->next
)
878 /* Avoid infinite recursion. We know we have the canonical
879 value, so we can just skip any values in the equivalence
881 if (REG_P (t
) || MEM_P (t
) || GET_CODE (t
) == VALUE
)
883 else if (rtx_equal_for_cselib_1 (t
, y
, memmode
, depth
+ 1))
889 else if (GET_CODE (y
) == VALUE
)
891 cselib_val
*e
= canonical_cselib_val (CSELIB_VAL_PTR (y
));
892 struct elt_loc_list
*l
;
897 for (l
= e
->locs
; l
; l
= l
->next
)
901 if (REG_P (t
) || MEM_P (t
) || GET_CODE (t
) == VALUE
)
903 else if (rtx_equal_for_cselib_1 (x
, t
, memmode
, depth
+ 1))
910 if (GET_MODE (x
) != GET_MODE (y
))
913 if (GET_CODE (x
) != GET_CODE (y
))
915 rtx xorig
= x
, yorig
= y
;
916 rtx xoff
= NULL
, yoff
= NULL
;
918 x
= autoinc_split (x
, &xoff
, memmode
);
919 y
= autoinc_split (y
, &yoff
, memmode
);
924 if (xoff
&& !rtx_equal_for_cselib_1 (xoff
, yoff
, memmode
, depth
))
927 /* Don't recurse if nothing changed. */
928 if (x
!= xorig
|| y
!= yorig
)
929 return rtx_equal_for_cselib_1 (x
, y
, memmode
, depth
);
934 /* These won't be handled correctly by the code below. */
935 switch (GET_CODE (x
))
941 case DEBUG_IMPLICIT_PTR
:
942 return DEBUG_IMPLICIT_PTR_DECL (x
)
943 == DEBUG_IMPLICIT_PTR_DECL (y
);
945 case DEBUG_PARAMETER_REF
:
946 return DEBUG_PARAMETER_REF_DECL (x
)
947 == DEBUG_PARAMETER_REF_DECL (y
);
950 /* ENTRY_VALUEs are function invariant, it is thus undesirable to
951 use rtx_equal_for_cselib_1 to compare the operands. */
952 return rtx_equal_p (ENTRY_VALUE_EXP (x
), ENTRY_VALUE_EXP (y
));
955 return label_ref_label (x
) == label_ref_label (y
);
958 return REGNO (x
) == REGNO (y
);
961 /* We have to compare any autoinc operations in the addresses
962 using this MEM's mode. */
963 return rtx_equal_for_cselib_1 (XEXP (x
, 0), XEXP (y
, 0), GET_MODE (x
),
971 fmt
= GET_RTX_FORMAT (code
);
973 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
980 if (XWINT (x
, i
) != XWINT (y
, i
))
986 if (XINT (x
, i
) != XINT (y
, i
))
991 if (maybe_ne (SUBREG_BYTE (x
), SUBREG_BYTE (y
)))
997 /* Two vectors must have the same length. */
998 if (XVECLEN (x
, i
) != XVECLEN (y
, i
))
1001 /* And the corresponding elements must match. */
1002 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
1003 if (! rtx_equal_for_cselib_1 (XVECEXP (x
, i
, j
),
1004 XVECEXP (y
, i
, j
), memmode
, depth
))
1010 && targetm
.commutative_p (x
, UNKNOWN
)
1011 && rtx_equal_for_cselib_1 (XEXP (x
, 1), XEXP (y
, 0), memmode
,
1013 && rtx_equal_for_cselib_1 (XEXP (x
, 0), XEXP (y
, 1), memmode
,
1016 if (! rtx_equal_for_cselib_1 (XEXP (x
, i
), XEXP (y
, i
), memmode
,
1023 if (strcmp (XSTR (x
, i
), XSTR (y
, i
)))
1028 /* These are just backpointers, so they don't matter. */
1035 /* It is believed that rtx's at this level will never
1036 contain anything but integers and other rtx's,
1037 except for within LABEL_REFs and SYMBOL_REFs. */
1045 /* Hash an rtx. Return 0 if we couldn't hash the rtx.
1046 For registers and memory locations, we look up their cselib_val structure
1047 and return its VALUE element.
1048 Possible reasons for return 0 are: the object is volatile, or we couldn't
1049 find a register or memory location in the table and CREATE is zero. If
1050 CREATE is nonzero, table elts are created for regs and mem.
1051 N.B. this hash function returns the same hash value for RTXes that
1052 differ only in the order of operands, thus it is suitable for comparisons
1053 that take commutativity into account.
1054 If we wanted to also support associative rules, we'd have to use a different
1055 strategy to avoid returning spurious 0, e.g. return ~(~0U >> 1) .
1056 MEMMODE indicates the mode of an enclosing MEM, and it's only
1057 used to compute autoinc values.
1058 We used to have a MODE argument for hashing for CONST_INTs, but that
1059 didn't make sense, since it caused spurious hash differences between
1060 (set (reg:SI 1) (const_int))
1061 (plus:SI (reg:SI 2) (reg:SI 1))
1063 (plus:SI (reg:SI 2) (const_int))
1064 If the mode is important in any context, it must be checked specifically
1065 in a comparison anyway, since relying on hash differences is unsafe. */
1068 cselib_hash_rtx (rtx x
, int create
, machine_mode memmode
)
1074 unsigned int hash
= 0;
1076 code
= GET_CODE (x
);
1077 hash
+= (unsigned) code
+ (unsigned) GET_MODE (x
);
1082 e
= CSELIB_VAL_PTR (x
);
1087 e
= cselib_lookup (x
, GET_MODE (x
), create
, memmode
);
1094 hash
+= ((unsigned) DEBUG_EXPR
<< 7)
1095 + DEBUG_TEMP_UID (DEBUG_EXPR_TREE_DECL (x
));
1096 return hash
? hash
: (unsigned int) DEBUG_EXPR
;
1098 case DEBUG_IMPLICIT_PTR
:
1099 hash
+= ((unsigned) DEBUG_IMPLICIT_PTR
<< 7)
1100 + DECL_UID (DEBUG_IMPLICIT_PTR_DECL (x
));
1101 return hash
? hash
: (unsigned int) DEBUG_IMPLICIT_PTR
;
1103 case DEBUG_PARAMETER_REF
:
1104 hash
+= ((unsigned) DEBUG_PARAMETER_REF
<< 7)
1105 + DECL_UID (DEBUG_PARAMETER_REF_DECL (x
));
1106 return hash
? hash
: (unsigned int) DEBUG_PARAMETER_REF
;
1109 /* ENTRY_VALUEs are function invariant, thus try to avoid
1110 recursing on argument if ENTRY_VALUE is one of the
1111 forms emitted by expand_debug_expr, otherwise
1112 ENTRY_VALUE hash would depend on the current value
1113 in some register or memory. */
1114 if (REG_P (ENTRY_VALUE_EXP (x
)))
1115 hash
+= (unsigned int) REG
1116 + (unsigned int) GET_MODE (ENTRY_VALUE_EXP (x
))
1117 + (unsigned int) REGNO (ENTRY_VALUE_EXP (x
));
1118 else if (MEM_P (ENTRY_VALUE_EXP (x
))
1119 && REG_P (XEXP (ENTRY_VALUE_EXP (x
), 0)))
1120 hash
+= (unsigned int) MEM
1121 + (unsigned int) GET_MODE (XEXP (ENTRY_VALUE_EXP (x
), 0))
1122 + (unsigned int) REGNO (XEXP (ENTRY_VALUE_EXP (x
), 0));
1124 hash
+= cselib_hash_rtx (ENTRY_VALUE_EXP (x
), create
, memmode
);
1125 return hash
? hash
: (unsigned int) ENTRY_VALUE
;
1128 hash
+= ((unsigned) CONST_INT
<< 7) + UINTVAL (x
);
1129 return hash
? hash
: (unsigned int) CONST_INT
;
1131 case CONST_WIDE_INT
:
1132 for (i
= 0; i
< CONST_WIDE_INT_NUNITS (x
); i
++)
1133 hash
+= CONST_WIDE_INT_ELT (x
, i
);
1136 case CONST_POLY_INT
:
1140 for (unsigned int i
= 0; i
< NUM_POLY_INT_COEFFS
; ++i
)
1141 h
.add_wide_int (CONST_POLY_INT_COEFFS (x
)[i
]);
1146 /* This is like the general case, except that it only counts
1147 the integers representing the constant. */
1148 hash
+= (unsigned) code
+ (unsigned) GET_MODE (x
);
1149 if (TARGET_SUPPORTS_WIDE_INT
== 0 && GET_MODE (x
) == VOIDmode
)
1150 hash
+= ((unsigned) CONST_DOUBLE_LOW (x
)
1151 + (unsigned) CONST_DOUBLE_HIGH (x
));
1153 hash
+= real_hash (CONST_DOUBLE_REAL_VALUE (x
));
1154 return hash
? hash
: (unsigned int) CONST_DOUBLE
;
1157 hash
+= (unsigned int) code
+ (unsigned int) GET_MODE (x
);
1158 hash
+= fixed_hash (CONST_FIXED_VALUE (x
));
1159 return hash
? hash
: (unsigned int) CONST_FIXED
;
1166 units
= CONST_VECTOR_NUNITS (x
);
1168 for (i
= 0; i
< units
; ++i
)
1170 elt
= CONST_VECTOR_ELT (x
, i
);
1171 hash
+= cselib_hash_rtx (elt
, 0, memmode
);
1177 /* Assume there is only one rtx object for any given label. */
1179 /* We don't hash on the address of the CODE_LABEL to avoid bootstrap
1180 differences and differences between each stage's debugging dumps. */
1181 hash
+= (((unsigned int) LABEL_REF
<< 7)
1182 + CODE_LABEL_NUMBER (label_ref_label (x
)));
1183 return hash
? hash
: (unsigned int) LABEL_REF
;
1187 /* Don't hash on the symbol's address to avoid bootstrap differences.
1188 Different hash values may cause expressions to be recorded in
1189 different orders and thus different registers to be used in the
1190 final assembler. This also avoids differences in the dump files
1191 between various stages. */
1193 const unsigned char *p
= (const unsigned char *) XSTR (x
, 0);
1196 h
+= (h
<< 7) + *p
++; /* ??? revisit */
1198 hash
+= ((unsigned int) SYMBOL_REF
<< 7) + h
;
1199 return hash
? hash
: (unsigned int) SYMBOL_REF
;
1204 /* We can't compute these without knowing the MEM mode. */
1205 gcc_assert (memmode
!= VOIDmode
);
1206 i
= GET_MODE_SIZE (memmode
);
1207 if (code
== PRE_DEC
)
1209 /* Adjust the hash so that (mem:MEMMODE (pre_* (reg))) hashes
1210 like (mem:MEMMODE (plus (reg) (const_int I))). */
1211 hash
+= (unsigned) PLUS
- (unsigned)code
1212 + cselib_hash_rtx (XEXP (x
, 0), create
, memmode
)
1213 + cselib_hash_rtx (GEN_INT (i
), create
, memmode
);
1214 return hash
? hash
: 1 + (unsigned) PLUS
;
1217 gcc_assert (memmode
!= VOIDmode
);
1218 return cselib_hash_rtx (XEXP (x
, 1), create
, memmode
);
1223 gcc_assert (memmode
!= VOIDmode
);
1224 return cselib_hash_rtx (XEXP (x
, 0), create
, memmode
);
1229 case UNSPEC_VOLATILE
:
1233 if (MEM_VOLATILE_P (x
))
1242 i
= GET_RTX_LENGTH (code
) - 1;
1243 fmt
= GET_RTX_FORMAT (code
);
1250 rtx tem
= XEXP (x
, i
);
1251 unsigned int tem_hash
= cselib_hash_rtx (tem
, create
, memmode
);
1260 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
1262 unsigned int tem_hash
1263 = cselib_hash_rtx (XVECEXP (x
, i
, j
), create
, memmode
);
1274 const unsigned char *p
= (const unsigned char *) XSTR (x
, i
);
1283 hash
+= XINT (x
, i
);
1287 hash
+= constant_lower_bound (SUBREG_BYTE (x
));
1300 return hash
? hash
: 1 + (unsigned int) GET_CODE (x
);
1303 /* Create a new value structure for VALUE and initialize it. The mode of the
1306 static inline cselib_val
*
1307 new_cselib_val (unsigned int hash
, machine_mode mode
, rtx x
)
1309 cselib_val
*e
= cselib_val_pool
.allocate ();
1312 gcc_assert (next_uid
);
1315 e
->uid
= next_uid
++;
1316 /* We use an alloc pool to allocate this RTL construct because it
1317 accounts for about 8% of the overall memory usage. We know
1318 precisely when we can have VALUE RTXen (when cselib is active)
1319 so we don't need to put them in garbage collected memory.
1320 ??? Why should a VALUE be an RTX in the first place? */
1321 e
->val_rtx
= (rtx_def
*) value_pool
.allocate ();
1322 memset (e
->val_rtx
, 0, RTX_HDR_SIZE
);
1323 PUT_CODE (e
->val_rtx
, VALUE
);
1324 PUT_MODE (e
->val_rtx
, mode
);
1325 CSELIB_VAL_PTR (e
->val_rtx
) = e
;
1328 e
->next_containing_mem
= 0;
1330 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1332 fprintf (dump_file
, "cselib value %u:%u ", e
->uid
, hash
);
1333 if (flag_dump_noaddr
|| flag_dump_unnumbered
)
1334 fputs ("# ", dump_file
);
1336 fprintf (dump_file
, "%p ", (void*)e
);
1337 print_rtl_single (dump_file
, x
);
1338 fputc ('\n', dump_file
);
1344 /* ADDR_ELT is a value that is used as address. MEM_ELT is the value that
1345 contains the data at this address. X is a MEM that represents the
1346 value. Update the two value structures to represent this situation. */
1349 add_mem_for_addr (cselib_val
*addr_elt
, cselib_val
*mem_elt
, rtx x
)
1351 addr_elt
= canonical_cselib_val (addr_elt
);
1352 mem_elt
= canonical_cselib_val (mem_elt
);
1354 /* Avoid duplicates. */
1355 addr_space_t as
= MEM_ADDR_SPACE (x
);
1356 for (elt_loc_list
*l
= mem_elt
->locs
; l
; l
= l
->next
)
1358 && CSELIB_VAL_PTR (XEXP (l
->loc
, 0)) == addr_elt
1359 && MEM_ADDR_SPACE (l
->loc
) == as
)
1361 promote_debug_loc (l
);
1365 addr_elt
->addr_list
= new_elt_list (addr_elt
->addr_list
, mem_elt
);
1366 new_elt_loc_list (mem_elt
,
1367 replace_equiv_address_nv (x
, addr_elt
->val_rtx
));
1368 if (mem_elt
->next_containing_mem
== NULL
)
1370 mem_elt
->next_containing_mem
= first_containing_mem
;
1371 first_containing_mem
= mem_elt
;
1375 /* Subroutine of cselib_lookup. Return a value for X, which is a MEM rtx.
1376 If CREATE, make a new one if we haven't seen it before. */
1379 cselib_lookup_mem (rtx x
, int create
)
1381 machine_mode mode
= GET_MODE (x
);
1382 machine_mode addr_mode
;
1385 cselib_val
*mem_elt
;
1387 if (MEM_VOLATILE_P (x
) || mode
== BLKmode
1388 || !cselib_record_memory
1389 || (FLOAT_MODE_P (mode
) && flag_float_store
))
1392 addr_mode
= GET_MODE (XEXP (x
, 0));
1393 if (addr_mode
== VOIDmode
)
1396 /* Look up the value for the address. */
1397 addr
= cselib_lookup (XEXP (x
, 0), addr_mode
, create
, mode
);
1400 addr
= canonical_cselib_val (addr
);
1402 /* Find a value that describes a value of our mode at that address. */
1403 addr_space_t as
= MEM_ADDR_SPACE (x
);
1404 for (elt_list
*l
= addr
->addr_list
; l
; l
= l
->next
)
1405 if (GET_MODE (l
->elt
->val_rtx
) == mode
)
1407 for (elt_loc_list
*l2
= l
->elt
->locs
; l2
; l2
= l2
->next
)
1408 if (MEM_P (l2
->loc
) && MEM_ADDR_SPACE (l2
->loc
) == as
)
1410 promote_debug_loc (l
->elt
->locs
);
1418 mem_elt
= new_cselib_val (next_uid
, mode
, x
);
1419 add_mem_for_addr (addr
, mem_elt
, x
);
1420 slot
= cselib_find_slot (mode
, x
, mem_elt
->hash
, INSERT
, VOIDmode
);
1425 /* Search through the possible substitutions in P. We prefer a non reg
1426 substitution because this allows us to expand the tree further. If
1427 we find, just a reg, take the lowest regno. There may be several
1428 non-reg results, we just take the first one because they will all
1429 expand to the same place. */
1432 expand_loc (struct elt_loc_list
*p
, struct expand_value_data
*evd
,
1435 rtx reg_result
= NULL
;
1436 unsigned int regno
= UINT_MAX
;
1437 struct elt_loc_list
*p_in
= p
;
1439 for (; p
; p
= p
->next
)
1441 /* Return these right away to avoid returning stack pointer based
1442 expressions for frame pointer and vice versa, which is something
1443 that would confuse DSE. See the comment in cselib_expand_value_rtx_1
1444 for more details. */
1446 && (REGNO (p
->loc
) == STACK_POINTER_REGNUM
1447 || REGNO (p
->loc
) == FRAME_POINTER_REGNUM
1448 || REGNO (p
->loc
) == HARD_FRAME_POINTER_REGNUM
1449 || REGNO (p
->loc
) == cfa_base_preserved_regno
))
1451 /* Avoid infinite recursion trying to expand a reg into a
1453 if ((REG_P (p
->loc
))
1454 && (REGNO (p
->loc
) < regno
)
1455 && !bitmap_bit_p (evd
->regs_active
, REGNO (p
->loc
)))
1457 reg_result
= p
->loc
;
1458 regno
= REGNO (p
->loc
);
1460 /* Avoid infinite recursion and do not try to expand the
1462 else if (GET_CODE (p
->loc
) == VALUE
1463 && CSELIB_VAL_PTR (p
->loc
)->locs
== p_in
)
1465 else if (!REG_P (p
->loc
))
1468 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1470 print_inline_rtx (dump_file
, p
->loc
, 0);
1471 fprintf (dump_file
, "\n");
1473 if (GET_CODE (p
->loc
) == LO_SUM
1474 && GET_CODE (XEXP (p
->loc
, 1)) == SYMBOL_REF
1476 && (note
= find_reg_note (p
->setting_insn
, REG_EQUAL
, NULL_RTX
))
1477 && XEXP (note
, 0) == XEXP (p
->loc
, 1))
1478 return XEXP (p
->loc
, 1);
1479 result
= cselib_expand_value_rtx_1 (p
->loc
, evd
, max_depth
- 1);
1486 if (regno
!= UINT_MAX
)
1489 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1490 fprintf (dump_file
, "r%d\n", regno
);
1492 result
= cselib_expand_value_rtx_1 (reg_result
, evd
, max_depth
- 1);
1497 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1501 print_inline_rtx (dump_file
, reg_result
, 0);
1502 fprintf (dump_file
, "\n");
1505 fprintf (dump_file
, "NULL\n");
1511 /* Forward substitute and expand an expression out to its roots.
1512 This is the opposite of common subexpression. Because local value
1513 numbering is such a weak optimization, the expanded expression is
1514 pretty much unique (not from a pointer equals point of view but
1515 from a tree shape point of view.
1517 This function returns NULL if the expansion fails. The expansion
1518 will fail if there is no value number for one of the operands or if
1519 one of the operands has been overwritten between the current insn
1520 and the beginning of the basic block. For instance x has no
1526 REGS_ACTIVE is a scratch bitmap that should be clear when passing in.
1527 It is clear on return. */
1530 cselib_expand_value_rtx (rtx orig
, bitmap regs_active
, int max_depth
)
1532 struct expand_value_data evd
;
1534 evd
.regs_active
= regs_active
;
1535 evd
.callback
= NULL
;
1536 evd
.callback_arg
= NULL
;
1539 return cselib_expand_value_rtx_1 (orig
, &evd
, max_depth
);
1542 /* Same as cselib_expand_value_rtx, but using a callback to try to
1543 resolve some expressions. The CB function should return ORIG if it
1544 can't or does not want to deal with a certain RTX. Any other
1545 return value, including NULL, will be used as the expansion for
1546 VALUE, without any further changes. */
1549 cselib_expand_value_rtx_cb (rtx orig
, bitmap regs_active
, int max_depth
,
1550 cselib_expand_callback cb
, void *data
)
1552 struct expand_value_data evd
;
1554 evd
.regs_active
= regs_active
;
1556 evd
.callback_arg
= data
;
1559 return cselib_expand_value_rtx_1 (orig
, &evd
, max_depth
);
1562 /* Similar to cselib_expand_value_rtx_cb, but no rtxs are actually copied
1563 or simplified. Useful to find out whether cselib_expand_value_rtx_cb
1564 would return NULL or non-NULL, without allocating new rtx. */
1567 cselib_dummy_expand_value_rtx_cb (rtx orig
, bitmap regs_active
, int max_depth
,
1568 cselib_expand_callback cb
, void *data
)
1570 struct expand_value_data evd
;
1572 evd
.regs_active
= regs_active
;
1574 evd
.callback_arg
= data
;
1577 return cselib_expand_value_rtx_1 (orig
, &evd
, max_depth
) != NULL
;
1580 /* Internal implementation of cselib_expand_value_rtx and
1581 cselib_expand_value_rtx_cb. */
1584 cselib_expand_value_rtx_1 (rtx orig
, struct expand_value_data
*evd
,
1590 const char *format_ptr
;
1593 code
= GET_CODE (orig
);
1595 /* For the context of dse, if we end up expand into a huge tree, we
1596 will not have a useful address, so we might as well just give up
1605 struct elt_list
*l
= REG_VALUES (REGNO (orig
));
1607 if (l
&& l
->elt
== NULL
)
1609 for (; l
; l
= l
->next
)
1610 if (GET_MODE (l
->elt
->val_rtx
) == GET_MODE (orig
))
1613 unsigned regno
= REGNO (orig
);
1615 /* The only thing that we are not willing to do (this
1616 is requirement of dse and if others potential uses
1617 need this function we should add a parm to control
1618 it) is that we will not substitute the
1619 STACK_POINTER_REGNUM, FRAME_POINTER or the
1622 These expansions confuses the code that notices that
1623 stores into the frame go dead at the end of the
1624 function and that the frame is not effected by calls
1625 to subroutines. If you allow the
1626 STACK_POINTER_REGNUM substitution, then dse will
1627 think that parameter pushing also goes dead which is
1628 wrong. If you allow the FRAME_POINTER or the
1629 HARD_FRAME_POINTER then you lose the opportunity to
1630 make the frame assumptions. */
1631 if (regno
== STACK_POINTER_REGNUM
1632 || regno
== FRAME_POINTER_REGNUM
1633 || regno
== HARD_FRAME_POINTER_REGNUM
1634 || regno
== cfa_base_preserved_regno
)
1637 bitmap_set_bit (evd
->regs_active
, regno
);
1639 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1640 fprintf (dump_file
, "expanding: r%d into: ", regno
);
1642 result
= expand_loc (l
->elt
->locs
, evd
, max_depth
);
1643 bitmap_clear_bit (evd
->regs_active
, regno
);
1659 /* SCRATCH must be shared because they represent distinct values. */
1662 if (REG_P (XEXP (orig
, 0)) && HARD_REGISTER_NUM_P (REGNO (XEXP (orig
, 0))))
1667 if (shared_const_p (orig
))
1677 subreg
= evd
->callback (orig
, evd
->regs_active
, max_depth
,
1683 subreg
= cselib_expand_value_rtx_1 (SUBREG_REG (orig
), evd
,
1687 scopy
= simplify_gen_subreg (GET_MODE (orig
), subreg
,
1688 GET_MODE (SUBREG_REG (orig
)),
1689 SUBREG_BYTE (orig
));
1691 || (GET_CODE (scopy
) == SUBREG
1692 && !REG_P (SUBREG_REG (scopy
))
1693 && !MEM_P (SUBREG_REG (scopy
))))
1703 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
1705 fputs ("\nexpanding ", dump_file
);
1706 print_rtl_single (dump_file
, orig
);
1707 fputs (" into...", dump_file
);
1712 result
= evd
->callback (orig
, evd
->regs_active
, max_depth
,
1719 result
= expand_loc (CSELIB_VAL_PTR (orig
)->locs
, evd
, max_depth
);
1725 return evd
->callback (orig
, evd
->regs_active
, max_depth
,
1733 /* Copy the various flags, fields, and other information. We assume
1734 that all fields need copying, and then clear the fields that should
1735 not be copied. That is the sensible default behavior, and forces
1736 us to explicitly document why we are *not* copying a flag. */
1740 copy
= shallow_copy_rtx (orig
);
1742 format_ptr
= GET_RTX_FORMAT (code
);
1744 for (i
= 0; i
< GET_RTX_LENGTH (code
); i
++)
1745 switch (*format_ptr
++)
1748 if (XEXP (orig
, i
) != NULL
)
1750 rtx result
= cselib_expand_value_rtx_1 (XEXP (orig
, i
), evd
,
1755 XEXP (copy
, i
) = result
;
1761 if (XVEC (orig
, i
) != NULL
)
1764 XVEC (copy
, i
) = rtvec_alloc (XVECLEN (orig
, i
));
1765 for (j
= 0; j
< XVECLEN (orig
, i
); j
++)
1767 rtx result
= cselib_expand_value_rtx_1 (XVECEXP (orig
, i
, j
),
1768 evd
, max_depth
- 1);
1772 XVECEXP (copy
, i
, j
) = result
;
1786 /* These are left unchanged. */
1796 mode
= GET_MODE (copy
);
1797 /* If an operand has been simplified into CONST_INT, which doesn't
1798 have a mode and the mode isn't derivable from whole rtx's mode,
1799 try simplify_*_operation first with mode from original's operand
1800 and as a fallback wrap CONST_INT into gen_rtx_CONST. */
1802 switch (GET_RTX_CLASS (code
))
1805 if (CONST_INT_P (XEXP (copy
, 0))
1806 && GET_MODE (XEXP (orig
, 0)) != VOIDmode
)
1808 scopy
= simplify_unary_operation (code
, mode
, XEXP (copy
, 0),
1809 GET_MODE (XEXP (orig
, 0)));
1814 case RTX_COMM_ARITH
:
1816 /* These expressions can derive operand modes from the whole rtx's mode. */
1819 case RTX_BITFIELD_OPS
:
1820 if (CONST_INT_P (XEXP (copy
, 0))
1821 && GET_MODE (XEXP (orig
, 0)) != VOIDmode
)
1823 scopy
= simplify_ternary_operation (code
, mode
,
1824 GET_MODE (XEXP (orig
, 0)),
1825 XEXP (copy
, 0), XEXP (copy
, 1),
1832 case RTX_COMM_COMPARE
:
1833 if (CONST_INT_P (XEXP (copy
, 0))
1834 && GET_MODE (XEXP (copy
, 1)) == VOIDmode
1835 && (GET_MODE (XEXP (orig
, 0)) != VOIDmode
1836 || GET_MODE (XEXP (orig
, 1)) != VOIDmode
))
1838 scopy
= simplify_relational_operation (code
, mode
,
1839 (GET_MODE (XEXP (orig
, 0))
1841 ? GET_MODE (XEXP (orig
, 0))
1842 : GET_MODE (XEXP (orig
, 1)),
1852 scopy
= simplify_rtx (copy
);
1858 /* Walk rtx X and replace all occurrences of REG and MEM subexpressions
1859 with VALUE expressions. This way, it becomes independent of changes
1860 to registers and memory.
1861 X isn't actually modified; if modifications are needed, new rtl is
1862 allocated. However, the return value can share rtl with X.
1863 If X is within a MEM, MEMMODE must be the mode of the MEM. */
1866 cselib_subst_to_values (rtx x
, machine_mode memmode
)
1868 enum rtx_code code
= GET_CODE (x
);
1869 const char *fmt
= GET_RTX_FORMAT (code
);
1878 l
= REG_VALUES (REGNO (x
));
1879 if (l
&& l
->elt
== NULL
)
1881 for (; l
; l
= l
->next
)
1882 if (GET_MODE (l
->elt
->val_rtx
) == GET_MODE (x
))
1883 return l
->elt
->val_rtx
;
1888 e
= cselib_lookup_mem (x
, 0);
1889 /* This used to happen for autoincrements, but we deal with them
1890 properly now. Remove the if stmt for the next release. */
1893 /* Assign a value that doesn't match any other. */
1894 e
= new_cselib_val (next_uid
, GET_MODE (x
), x
);
1899 e
= cselib_lookup (x
, GET_MODE (x
), 0, memmode
);
1909 gcc_assert (memmode
!= VOIDmode
);
1910 i
= GET_MODE_SIZE (memmode
);
1911 if (code
== PRE_DEC
)
1913 return cselib_subst_to_values (plus_constant (GET_MODE (x
),
1918 gcc_assert (memmode
!= VOIDmode
);
1919 return cselib_subst_to_values (XEXP (x
, 1), memmode
);
1924 gcc_assert (memmode
!= VOIDmode
);
1925 return cselib_subst_to_values (XEXP (x
, 0), memmode
);
1931 for (i
= GET_RTX_LENGTH (code
) - 1; i
>= 0; i
--)
1935 rtx t
= cselib_subst_to_values (XEXP (x
, i
), memmode
);
1937 if (t
!= XEXP (x
, i
))
1940 copy
= shallow_copy_rtx (x
);
1944 else if (fmt
[i
] == 'E')
1948 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
1950 rtx t
= cselib_subst_to_values (XVECEXP (x
, i
, j
), memmode
);
1952 if (t
!= XVECEXP (x
, i
, j
))
1954 if (XVEC (x
, i
) == XVEC (copy
, i
))
1957 copy
= shallow_copy_rtx (x
);
1958 XVEC (copy
, i
) = shallow_copy_rtvec (XVEC (x
, i
));
1960 XVECEXP (copy
, i
, j
) = t
;
1969 /* Wrapper for cselib_subst_to_values, that indicates X is in INSN. */
1972 cselib_subst_to_values_from_insn (rtx x
, machine_mode memmode
, rtx_insn
*insn
)
1975 gcc_assert (!cselib_current_insn
);
1976 cselib_current_insn
= insn
;
1977 ret
= cselib_subst_to_values (x
, memmode
);
1978 cselib_current_insn
= NULL
;
1982 /* Look up the rtl expression X in our tables and return the value it
1983 has. If CREATE is zero, we return NULL if we don't know the value.
1984 Otherwise, we create a new one if possible, using mode MODE if X
1985 doesn't have a mode (i.e. because it's a constant). When X is part
1986 of an address, MEMMODE should be the mode of the enclosing MEM if
1987 we're tracking autoinc expressions. */
1990 cselib_lookup_1 (rtx x
, machine_mode mode
,
1991 int create
, machine_mode memmode
)
1995 unsigned int hashval
;
1997 if (GET_MODE (x
) != VOIDmode
)
1998 mode
= GET_MODE (x
);
2000 if (GET_CODE (x
) == VALUE
)
2001 return CSELIB_VAL_PTR (x
);
2006 unsigned int i
= REGNO (x
);
2009 if (l
&& l
->elt
== NULL
)
2011 for (; l
; l
= l
->next
)
2012 if (mode
== GET_MODE (l
->elt
->val_rtx
))
2014 promote_debug_loc (l
->elt
->locs
);
2021 if (i
< FIRST_PSEUDO_REGISTER
)
2023 unsigned int n
= hard_regno_nregs (i
, mode
);
2025 if (n
> max_value_regs
)
2029 e
= new_cselib_val (next_uid
, GET_MODE (x
), x
);
2030 new_elt_loc_list (e
, x
);
2032 scalar_int_mode int_mode
;
2033 if (REG_VALUES (i
) == 0)
2035 /* Maintain the invariant that the first entry of
2036 REG_VALUES, if present, must be the value used to set the
2037 register, or NULL. */
2038 used_regs
[n_used_regs
++] = i
;
2039 REG_VALUES (i
) = new_elt_list (REG_VALUES (i
), NULL
);
2041 else if (cselib_preserve_constants
2042 && is_int_mode (mode
, &int_mode
))
2044 /* During var-tracking, try harder to find equivalences
2045 for SUBREGs. If a setter sets say a DImode register
2046 and user uses that register only in SImode, add a lowpart
2048 struct elt_list
*lwider
= NULL
;
2049 scalar_int_mode lmode
;
2051 if (l
&& l
->elt
== NULL
)
2053 for (; l
; l
= l
->next
)
2054 if (is_int_mode (GET_MODE (l
->elt
->val_rtx
), &lmode
)
2055 && GET_MODE_SIZE (lmode
) > GET_MODE_SIZE (int_mode
)
2057 || partial_subreg_p (lmode
,
2058 GET_MODE (lwider
->elt
->val_rtx
))))
2060 struct elt_loc_list
*el
;
2061 if (i
< FIRST_PSEUDO_REGISTER
2062 && hard_regno_nregs (i
, lmode
) != 1)
2064 for (el
= l
->elt
->locs
; el
; el
= el
->next
)
2065 if (!REG_P (el
->loc
))
2072 rtx sub
= lowpart_subreg (int_mode
, lwider
->elt
->val_rtx
,
2073 GET_MODE (lwider
->elt
->val_rtx
));
2075 new_elt_loc_list (e
, sub
);
2078 REG_VALUES (i
)->next
= new_elt_list (REG_VALUES (i
)->next
, e
);
2079 slot
= cselib_find_slot (mode
, x
, e
->hash
, INSERT
, memmode
);
2085 return cselib_lookup_mem (x
, create
);
2087 hashval
= cselib_hash_rtx (x
, create
, memmode
);
2088 /* Can't even create if hashing is not possible. */
2092 slot
= cselib_find_slot (mode
, x
, hashval
,
2093 create
? INSERT
: NO_INSERT
, memmode
);
2097 e
= (cselib_val
*) *slot
;
2101 e
= new_cselib_val (hashval
, mode
, x
);
2103 /* We have to fill the slot before calling cselib_subst_to_values:
2104 the hash table is inconsistent until we do so, and
2105 cselib_subst_to_values will need to do lookups. */
2107 new_elt_loc_list (e
, cselib_subst_to_values (x
, memmode
));
2111 /* Wrapper for cselib_lookup, that indicates X is in INSN. */
2114 cselib_lookup_from_insn (rtx x
, machine_mode mode
,
2115 int create
, machine_mode memmode
, rtx_insn
*insn
)
2119 gcc_assert (!cselib_current_insn
);
2120 cselib_current_insn
= insn
;
2122 ret
= cselib_lookup (x
, mode
, create
, memmode
);
2124 cselib_current_insn
= NULL
;
2129 /* Wrapper for cselib_lookup_1, that logs the lookup result and
2130 maintains invariants related with debug insns. */
2133 cselib_lookup (rtx x
, machine_mode mode
,
2134 int create
, machine_mode memmode
)
2136 cselib_val
*ret
= cselib_lookup_1 (x
, mode
, create
, memmode
);
2138 /* ??? Should we return NULL if we're not to create an entry, the
2139 found loc is a debug loc and cselib_current_insn is not DEBUG?
2140 If so, we should also avoid converting val to non-DEBUG; probably
2141 easiest setting cselib_current_insn to NULL before the call
2144 if (dump_file
&& (dump_flags
& TDF_CSELIB
))
2146 fputs ("cselib lookup ", dump_file
);
2147 print_inline_rtx (dump_file
, x
, 2);
2148 fprintf (dump_file
, " => %u:%u\n",
2150 ret
? ret
->hash
: 0);
2156 /* Invalidate any entries in reg_values that overlap REGNO. This is called
2157 if REGNO is changing. MODE is the mode of the assignment to REGNO, which
2158 is used to determine how many hard registers are being changed. If MODE
2159 is VOIDmode, then only REGNO is being changed; this is used when
2160 invalidating call clobbered registers across a call. */
2163 cselib_invalidate_regno (unsigned int regno
, machine_mode mode
)
2165 unsigned int endregno
;
2168 /* If we see pseudos after reload, something is _wrong_. */
2169 gcc_assert (!reload_completed
|| regno
< FIRST_PSEUDO_REGISTER
2170 || reg_renumber
[regno
] < 0);
2172 /* Determine the range of registers that must be invalidated. For
2173 pseudos, only REGNO is affected. For hard regs, we must take MODE
2174 into account, and we must also invalidate lower register numbers
2175 if they contain values that overlap REGNO. */
2176 if (regno
< FIRST_PSEUDO_REGISTER
)
2178 gcc_assert (mode
!= VOIDmode
);
2180 if (regno
< max_value_regs
)
2183 i
= regno
- max_value_regs
;
2185 endregno
= end_hard_regno (mode
, regno
);
2190 endregno
= regno
+ 1;
2193 for (; i
< endregno
; i
++)
2195 struct elt_list
**l
= ®_VALUES (i
);
2197 /* Go through all known values for this reg; if it overlaps the range
2198 we're invalidating, remove the value. */
2201 cselib_val
*v
= (*l
)->elt
;
2203 rtx_insn
*setting_insn
;
2204 struct elt_loc_list
**p
;
2205 unsigned int this_last
= i
;
2207 if (i
< FIRST_PSEUDO_REGISTER
&& v
!= NULL
)
2208 this_last
= end_hard_regno (GET_MODE (v
->val_rtx
), i
) - 1;
2210 if (this_last
< regno
|| v
== NULL
2211 || (v
== cfa_base_preserved_val
2212 && i
== cfa_base_preserved_regno
))
2218 /* We have an overlap. */
2219 if (*l
== REG_VALUES (i
))
2221 /* Maintain the invariant that the first entry of
2222 REG_VALUES, if present, must be the value used to set
2223 the register, or NULL. This is also nice because
2224 then we won't push the same regno onto user_regs
2230 unchain_one_elt_list (l
);
2232 v
= canonical_cselib_val (v
);
2234 had_locs
= v
->locs
!= NULL
;
2235 setting_insn
= v
->locs
? v
->locs
->setting_insn
: NULL
;
2237 /* Now, we clear the mapping from value to reg. It must exist, so
2238 this code will crash intentionally if it doesn't. */
2239 for (p
= &v
->locs
; ; p
= &(*p
)->next
)
2243 if (REG_P (x
) && REGNO (x
) == i
)
2245 unchain_one_elt_loc_list (p
);
2250 if (had_locs
&& v
->locs
== 0 && !PRESERVED_VALUE_P (v
->val_rtx
))
2252 if (setting_insn
&& DEBUG_INSN_P (setting_insn
))
2253 n_useless_debug_values
++;
2261 /* Invalidate any locations in the table which are changed because of a
2262 store to MEM_RTX. If this is called because of a non-const call
2263 instruction, MEM_RTX is (mem:BLK const0_rtx). */
2266 cselib_invalidate_mem (rtx mem_rtx
)
2268 cselib_val
**vp
, *v
, *next
;
2272 mem_addr
= canon_rtx (get_addr (XEXP (mem_rtx
, 0)));
2273 mem_rtx
= canon_rtx (mem_rtx
);
2275 vp
= &first_containing_mem
;
2276 for (v
= *vp
; v
!= &dummy_val
; v
= next
)
2278 bool has_mem
= false;
2279 struct elt_loc_list
**p
= &v
->locs
;
2280 bool had_locs
= v
->locs
!= NULL
;
2281 rtx_insn
*setting_insn
= v
->locs
? v
->locs
->setting_insn
: NULL
;
2287 struct elt_list
**mem_chain
;
2289 /* MEMs may occur in locations only at the top level; below
2290 that every MEM or REG is substituted by its VALUE. */
2296 if (num_mems
< PARAM_VALUE (PARAM_MAX_CSELIB_MEMORY_LOCATIONS
)
2297 && ! canon_anti_dependence (x
, false, mem_rtx
,
2298 GET_MODE (mem_rtx
), mem_addr
))
2306 /* This one overlaps. */
2307 /* We must have a mapping from this MEM's address to the
2308 value (E). Remove that, too. */
2309 addr
= cselib_lookup (XEXP (x
, 0), VOIDmode
, 0, GET_MODE (x
));
2310 addr
= canonical_cselib_val (addr
);
2311 gcc_checking_assert (v
== canonical_cselib_val (v
));
2312 mem_chain
= &addr
->addr_list
;
2315 cselib_val
*canon
= canonical_cselib_val ((*mem_chain
)->elt
);
2319 unchain_one_elt_list (mem_chain
);
2323 /* Record canonicalized elt. */
2324 (*mem_chain
)->elt
= canon
;
2326 mem_chain
= &(*mem_chain
)->next
;
2329 unchain_one_elt_loc_list (p
);
2332 if (had_locs
&& v
->locs
== 0 && !PRESERVED_VALUE_P (v
->val_rtx
))
2334 if (setting_insn
&& DEBUG_INSN_P (setting_insn
))
2335 n_useless_debug_values
++;
2340 next
= v
->next_containing_mem
;
2344 vp
= &(*vp
)->next_containing_mem
;
2347 v
->next_containing_mem
= NULL
;
2352 /* Invalidate DEST, which is being assigned to or clobbered. */
2355 cselib_invalidate_rtx (rtx dest
)
2357 while (GET_CODE (dest
) == SUBREG
2358 || GET_CODE (dest
) == ZERO_EXTRACT
2359 || GET_CODE (dest
) == STRICT_LOW_PART
)
2360 dest
= XEXP (dest
, 0);
2363 cselib_invalidate_regno (REGNO (dest
), GET_MODE (dest
));
2364 else if (MEM_P (dest
))
2365 cselib_invalidate_mem (dest
);
2368 /* A wrapper for cselib_invalidate_rtx to be called via note_stores. */
2371 cselib_invalidate_rtx_note_stores (rtx dest
, const_rtx ignore ATTRIBUTE_UNUSED
,
2372 void *data ATTRIBUTE_UNUSED
)
2374 cselib_invalidate_rtx (dest
);
2377 /* Record the result of a SET instruction. DEST is being set; the source
2378 contains the value described by SRC_ELT. If DEST is a MEM, DEST_ADDR_ELT
2379 describes its address. */
2382 cselib_record_set (rtx dest
, cselib_val
*src_elt
, cselib_val
*dest_addr_elt
)
2384 if (src_elt
== 0 || side_effects_p (dest
))
2389 unsigned int dreg
= REGNO (dest
);
2390 if (dreg
< FIRST_PSEUDO_REGISTER
)
2392 unsigned int n
= REG_NREGS (dest
);
2394 if (n
> max_value_regs
)
2398 if (REG_VALUES (dreg
) == 0)
2400 used_regs
[n_used_regs
++] = dreg
;
2401 REG_VALUES (dreg
) = new_elt_list (REG_VALUES (dreg
), src_elt
);
2405 /* The register should have been invalidated. */
2406 gcc_assert (REG_VALUES (dreg
)->elt
== 0);
2407 REG_VALUES (dreg
)->elt
= src_elt
;
2410 if (src_elt
->locs
== 0 && !PRESERVED_VALUE_P (src_elt
->val_rtx
))
2412 new_elt_loc_list (src_elt
, dest
);
2414 else if (MEM_P (dest
) && dest_addr_elt
!= 0
2415 && cselib_record_memory
)
2417 if (src_elt
->locs
== 0 && !PRESERVED_VALUE_P (src_elt
->val_rtx
))
2419 add_mem_for_addr (dest_addr_elt
, src_elt
, dest
);
2423 /* Make ELT and X's VALUE equivalent to each other at INSN. */
2426 cselib_add_permanent_equiv (cselib_val
*elt
, rtx x
, rtx_insn
*insn
)
2429 rtx_insn
*save_cselib_current_insn
= cselib_current_insn
;
2431 gcc_checking_assert (elt
);
2432 gcc_checking_assert (PRESERVED_VALUE_P (elt
->val_rtx
));
2433 gcc_checking_assert (!side_effects_p (x
));
2435 cselib_current_insn
= insn
;
2437 nelt
= cselib_lookup (x
, GET_MODE (elt
->val_rtx
), 1, VOIDmode
);
2441 cselib_any_perm_equivs
= true;
2443 if (!PRESERVED_VALUE_P (nelt
->val_rtx
))
2444 cselib_preserve_value (nelt
);
2446 new_elt_loc_list (nelt
, elt
->val_rtx
);
2449 cselib_current_insn
= save_cselib_current_insn
;
2452 /* Return TRUE if any permanent equivalences have been recorded since
2453 the table was last initialized. */
2455 cselib_have_permanent_equivalences (void)
2457 return cselib_any_perm_equivs
;
2460 /* There is no good way to determine how many elements there can be
2461 in a PARALLEL. Since it's fairly cheap, use a really large number. */
2462 #define MAX_SETS (FIRST_PSEUDO_REGISTER * 2)
2464 struct cselib_record_autoinc_data
2466 struct cselib_set
*sets
;
2470 /* Callback for for_each_inc_dec. Records in ARG the SETs implied by
2471 autoinc RTXs: SRC plus SRCOFF if non-NULL is stored in DEST. */
2474 cselib_record_autoinc_cb (rtx mem ATTRIBUTE_UNUSED
, rtx op ATTRIBUTE_UNUSED
,
2475 rtx dest
, rtx src
, rtx srcoff
, void *arg
)
2477 struct cselib_record_autoinc_data
*data
;
2478 data
= (struct cselib_record_autoinc_data
*)arg
;
2480 data
->sets
[data
->n_sets
].dest
= dest
;
2483 data
->sets
[data
->n_sets
].src
= gen_rtx_PLUS (GET_MODE (src
), src
, srcoff
);
2485 data
->sets
[data
->n_sets
].src
= src
;
2492 /* Record the effects of any sets and autoincs in INSN. */
2494 cselib_record_sets (rtx_insn
*insn
)
2498 struct cselib_set sets
[MAX_SETS
];
2499 rtx body
= PATTERN (insn
);
2501 int n_sets_before_autoinc
;
2502 struct cselib_record_autoinc_data data
;
2504 body
= PATTERN (insn
);
2505 if (GET_CODE (body
) == COND_EXEC
)
2507 cond
= COND_EXEC_TEST (body
);
2508 body
= COND_EXEC_CODE (body
);
2511 /* Find all sets. */
2512 if (GET_CODE (body
) == SET
)
2514 sets
[0].src
= SET_SRC (body
);
2515 sets
[0].dest
= SET_DEST (body
);
2518 else if (GET_CODE (body
) == PARALLEL
)
2520 /* Look through the PARALLEL and record the values being
2521 set, if possible. Also handle any CLOBBERs. */
2522 for (i
= XVECLEN (body
, 0) - 1; i
>= 0; --i
)
2524 rtx x
= XVECEXP (body
, 0, i
);
2526 if (GET_CODE (x
) == SET
)
2528 sets
[n_sets
].src
= SET_SRC (x
);
2529 sets
[n_sets
].dest
= SET_DEST (x
);
2536 && MEM_P (sets
[0].src
)
2537 && !cselib_record_memory
2538 && MEM_READONLY_P (sets
[0].src
))
2540 rtx note
= find_reg_equal_equiv_note (insn
);
2542 if (note
&& CONSTANT_P (XEXP (note
, 0)))
2543 sets
[0].src
= XEXP (note
, 0);
2547 data
.n_sets
= n_sets_before_autoinc
= n_sets
;
2548 for_each_inc_dec (PATTERN (insn
), cselib_record_autoinc_cb
, &data
);
2549 n_sets
= data
.n_sets
;
2551 /* Look up the values that are read. Do this before invalidating the
2552 locations that are written. */
2553 for (i
= 0; i
< n_sets
; i
++)
2555 rtx dest
= sets
[i
].dest
;
2557 /* A STRICT_LOW_PART can be ignored; we'll record the equivalence for
2558 the low part after invalidating any knowledge about larger modes. */
2559 if (GET_CODE (sets
[i
].dest
) == STRICT_LOW_PART
)
2560 sets
[i
].dest
= dest
= XEXP (dest
, 0);
2562 /* We don't know how to record anything but REG or MEM. */
2564 || (MEM_P (dest
) && cselib_record_memory
))
2566 rtx src
= sets
[i
].src
;
2568 src
= gen_rtx_IF_THEN_ELSE (GET_MODE (dest
), cond
, src
, dest
);
2569 sets
[i
].src_elt
= cselib_lookup (src
, GET_MODE (dest
), 1, VOIDmode
);
2572 machine_mode address_mode
= get_address_mode (dest
);
2574 sets
[i
].dest_addr_elt
= cselib_lookup (XEXP (dest
, 0),
2579 sets
[i
].dest_addr_elt
= 0;
2583 if (cselib_record_sets_hook
)
2584 cselib_record_sets_hook (insn
, sets
, n_sets
);
2586 /* Invalidate all locations written by this insn. Note that the elts we
2587 looked up in the previous loop aren't affected, just some of their
2588 locations may go away. */
2589 note_stores (body
, cselib_invalidate_rtx_note_stores
, NULL
);
2591 for (i
= n_sets_before_autoinc
; i
< n_sets
; i
++)
2592 cselib_invalidate_rtx (sets
[i
].dest
);
2594 /* If this is an asm, look for duplicate sets. This can happen when the
2595 user uses the same value as an output multiple times. This is valid
2596 if the outputs are not actually used thereafter. Treat this case as
2597 if the value isn't actually set. We do this by smashing the destination
2598 to pc_rtx, so that we won't record the value later. */
2599 if (n_sets
>= 2 && asm_noperands (body
) >= 0)
2601 for (i
= 0; i
< n_sets
; i
++)
2603 rtx dest
= sets
[i
].dest
;
2604 if (REG_P (dest
) || MEM_P (dest
))
2607 for (j
= i
+ 1; j
< n_sets
; j
++)
2608 if (rtx_equal_p (dest
, sets
[j
].dest
))
2610 sets
[i
].dest
= pc_rtx
;
2611 sets
[j
].dest
= pc_rtx
;
2617 /* Now enter the equivalences in our tables. */
2618 for (i
= 0; i
< n_sets
; i
++)
2620 rtx dest
= sets
[i
].dest
;
2622 || (MEM_P (dest
) && cselib_record_memory
))
2623 cselib_record_set (dest
, sets
[i
].src_elt
, sets
[i
].dest_addr_elt
);
2627 /* Return true if INSN in the prologue initializes hard_frame_pointer_rtx. */
2630 fp_setter_insn (rtx_insn
*insn
)
2632 rtx expr
, pat
= NULL_RTX
;
2634 if (!RTX_FRAME_RELATED_P (insn
))
2637 expr
= find_reg_note (insn
, REG_FRAME_RELATED_EXPR
, NULL_RTX
);
2639 pat
= XEXP (expr
, 0);
2640 if (!modified_in_p (hard_frame_pointer_rtx
, pat
? pat
: insn
))
2643 /* Don't return true for frame pointer restores in the epilogue. */
2644 if (find_reg_note (insn
, REG_CFA_RESTORE
, hard_frame_pointer_rtx
))
2649 /* Record the effects of INSN. */
2652 cselib_process_insn (rtx_insn
*insn
)
2657 cselib_current_insn
= insn
;
2659 /* Forget everything at a CODE_LABEL or a setjmp. */
2662 && find_reg_note (insn
, REG_SETJMP
, NULL
)))
2663 && !cselib_preserve_constants
)
2665 cselib_reset_table (next_uid
);
2666 cselib_current_insn
= NULL
;
2670 if (! INSN_P (insn
))
2672 cselib_current_insn
= NULL
;
2676 /* If this is a call instruction, forget anything stored in a
2677 call clobbered register, or, if this is not a const call, in
2681 for (i
= 0; i
< FIRST_PSEUDO_REGISTER
; i
++)
2682 if (call_used_regs
[i
]
2683 || (REG_VALUES (i
) && REG_VALUES (i
)->elt
2684 && (targetm
.hard_regno_call_part_clobbered
2685 (i
, GET_MODE (REG_VALUES (i
)->elt
->val_rtx
)))))
2686 cselib_invalidate_regno (i
, reg_raw_mode
[i
]);
2688 /* Since it is not clear how cselib is going to be used, be
2689 conservative here and treat looping pure or const functions
2690 as if they were regular functions. */
2691 if (RTL_LOOPING_CONST_OR_PURE_CALL_P (insn
)
2692 || !(RTL_CONST_OR_PURE_CALL_P (insn
)))
2693 cselib_invalidate_mem (callmem
);
2695 /* For const/pure calls, invalidate any argument slots because
2696 they are owned by the callee. */
2697 for (x
= CALL_INSN_FUNCTION_USAGE (insn
); x
; x
= XEXP (x
, 1))
2698 if (GET_CODE (XEXP (x
, 0)) == USE
2699 && MEM_P (XEXP (XEXP (x
, 0), 0)))
2700 cselib_invalidate_mem (XEXP (XEXP (x
, 0), 0));
2703 cselib_record_sets (insn
);
2705 /* Look for any CLOBBERs in CALL_INSN_FUNCTION_USAGE, but only
2706 after we have processed the insn. */
2709 for (x
= CALL_INSN_FUNCTION_USAGE (insn
); x
; x
= XEXP (x
, 1))
2710 if (GET_CODE (XEXP (x
, 0)) == CLOBBER
)
2711 cselib_invalidate_rtx (XEXP (XEXP (x
, 0), 0));
2712 /* Flush evertything on setjmp. */
2713 if (cselib_preserve_constants
2714 && find_reg_note (insn
, REG_SETJMP
, NULL
))
2716 cselib_preserve_only_values ();
2717 cselib_reset_table (next_uid
);
2721 /* On setter of the hard frame pointer if frame_pointer_needed,
2722 invalidate stack_pointer_rtx, so that sp and {,h}fp based
2723 VALUEs are distinct. */
2724 if (reload_completed
2725 && frame_pointer_needed
2726 && fp_setter_insn (insn
))
2727 cselib_invalidate_rtx (stack_pointer_rtx
);
2729 cselib_current_insn
= NULL
;
2731 if (n_useless_values
> MAX_USELESS_VALUES
2732 /* remove_useless_values is linear in the hash table size. Avoid
2733 quadratic behavior for very large hashtables with very few
2734 useless elements. */
2735 && ((unsigned int)n_useless_values
2736 > (cselib_hash_table
->elements () - n_debug_values
) / 4))
2737 remove_useless_values ();
2740 /* Initialize cselib for one pass. The caller must also call
2741 init_alias_analysis. */
2744 cselib_init (int record_what
)
2746 cselib_record_memory
= record_what
& CSELIB_RECORD_MEMORY
;
2747 cselib_preserve_constants
= record_what
& CSELIB_PRESERVE_CONSTANTS
;
2748 cselib_any_perm_equivs
= false;
2750 /* (mem:BLK (scratch)) is a special mechanism to conflict with everything,
2751 see canon_true_dependence. This is only created once. */
2753 callmem
= gen_rtx_MEM (BLKmode
, gen_rtx_SCRATCH (VOIDmode
));
2755 cselib_nregs
= max_reg_num ();
2757 /* We preserve reg_values to allow expensive clearing of the whole thing.
2758 Reallocate it however if it happens to be too large. */
2759 if (!reg_values
|| reg_values_size
< cselib_nregs
2760 || (reg_values_size
> 10 && reg_values_size
> cselib_nregs
* 4))
2763 /* Some space for newly emit instructions so we don't end up
2764 reallocating in between passes. */
2765 reg_values_size
= cselib_nregs
+ (63 + cselib_nregs
) / 16;
2766 reg_values
= XCNEWVEC (struct elt_list
*, reg_values_size
);
2768 used_regs
= XNEWVEC (unsigned int, cselib_nregs
);
2770 cselib_hash_table
= new hash_table
<cselib_hasher
> (31);
2771 if (cselib_preserve_constants
)
2772 cselib_preserved_hash_table
= new hash_table
<cselib_hasher
> (31);
2776 /* Called when the current user is done with cselib. */
2779 cselib_finish (void)
2781 bool preserved
= cselib_preserve_constants
;
2782 cselib_discard_hook
= NULL
;
2783 cselib_preserve_constants
= false;
2784 cselib_any_perm_equivs
= false;
2785 cfa_base_preserved_val
= NULL
;
2786 cfa_base_preserved_regno
= INVALID_REGNUM
;
2787 elt_list_pool
.release ();
2788 elt_loc_list_pool
.release ();
2789 cselib_val_pool
.release ();
2790 value_pool
.release ();
2791 cselib_clear_table ();
2792 delete cselib_hash_table
;
2793 cselib_hash_table
= NULL
;
2795 delete cselib_preserved_hash_table
;
2796 cselib_preserved_hash_table
= NULL
;
2799 n_useless_values
= 0;
2800 n_useless_debug_values
= 0;
2805 /* Dump the cselib_val *X to FILE *OUT. */
2808 dump_cselib_val (cselib_val
**x
, FILE *out
)
2811 bool need_lf
= true;
2813 print_inline_rtx (out
, v
->val_rtx
, 0);
2817 struct elt_loc_list
*l
= v
->locs
;
2823 fputs (" locs:", out
);
2826 if (l
->setting_insn
)
2827 fprintf (out
, "\n from insn %i ",
2828 INSN_UID (l
->setting_insn
));
2830 fprintf (out
, "\n ");
2831 print_inline_rtx (out
, l
->loc
, 4);
2833 while ((l
= l
->next
));
2838 fputs (" no locs", out
);
2844 struct elt_list
*e
= v
->addr_list
;
2850 fputs (" addr list:", out
);
2854 print_inline_rtx (out
, e
->elt
->val_rtx
, 2);
2856 while ((e
= e
->next
));
2861 fputs (" no addrs", out
);
2865 if (v
->next_containing_mem
== &dummy_val
)
2866 fputs (" last mem\n", out
);
2867 else if (v
->next_containing_mem
)
2869 fputs (" next mem ", out
);
2870 print_inline_rtx (out
, v
->next_containing_mem
->val_rtx
, 2);
2879 /* Dump to OUT everything in the CSELIB table. */
2882 dump_cselib_table (FILE *out
)
2884 fprintf (out
, "cselib hash table:\n");
2885 cselib_hash_table
->traverse
<FILE *, dump_cselib_val
> (out
);
2886 fprintf (out
, "cselib preserved hash table:\n");
2887 cselib_preserved_hash_table
->traverse
<FILE *, dump_cselib_val
> (out
);
2888 if (first_containing_mem
!= &dummy_val
)
2890 fputs ("first mem ", out
);
2891 print_inline_rtx (out
, first_containing_mem
->val_rtx
, 2);
2894 fprintf (out
, "next uid %i\n", next_uid
);
2897 #include "gt-cselib.h"