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/* Common subexpression elimination for GNU compiler.
Copyright (C) 1987-2017 Free Software Foundation, Inc.
This file is part of GCC.
GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
version.
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING3. If not see
<http://www.gnu.org/licenses/>. */
#ifndef GCC_CSELIB_H
#define GCC_CSELIB_H
/* Describe a value. */
struct cselib_val
{
/* The hash value. */
unsigned int hash;
/* A unique id assigned to values. */
int uid;
/* A VALUE rtx that points back to this structure. */
rtx val_rtx;
/* All rtl expressions that hold this value at the current time during a
scan. */
struct elt_loc_list *locs;
/* If this value is used as an address, points to a list of values that
use it as an address in a MEM. */
struct elt_list *addr_list;
struct cselib_val *next_containing_mem;
};
/* A list of rtl expressions that hold the same value. */
struct elt_loc_list {
/* Next element in the list. */
struct elt_loc_list *next;
/* An rtl expression that holds the value. */
rtx loc;
/* The insn that made the equivalence. */
rtx_insn *setting_insn;
};
/* Describe a single set that is part of an insn. */
struct cselib_set
{
rtx src;
rtx dest;
cselib_val *src_elt;
cselib_val *dest_addr_elt;
};
enum cselib_record_what
{
CSELIB_RECORD_MEMORY = 1,
CSELIB_PRESERVE_CONSTANTS = 2
};
extern void (*cselib_discard_hook) (cselib_val *);
extern void (*cselib_record_sets_hook) (rtx_insn *insn, struct cselib_set *sets,
int n_sets);
extern cselib_val *cselib_lookup (rtx, machine_mode,
int, machine_mode);
extern cselib_val *cselib_lookup_from_insn (rtx, machine_mode,
int, machine_mode, rtx_insn *);
extern void cselib_init (int);
extern void cselib_clear_table (void);
extern void cselib_finish (void);
extern void cselib_process_insn (rtx_insn *);
extern bool fp_setter_insn (rtx_insn *);
extern machine_mode cselib_reg_set_mode (const_rtx);
extern int rtx_equal_for_cselib_1 (rtx, rtx, machine_mode, int);
extern int references_value_p (const_rtx, int);
extern rtx cselib_expand_value_rtx (rtx, bitmap, int);
typedef rtx (*cselib_expand_callback)(rtx, bitmap, int, void *);
extern rtx cselib_expand_value_rtx_cb (rtx, bitmap, int,
cselib_expand_callback, void *);
extern bool cselib_dummy_expand_value_rtx_cb (rtx, bitmap, int,
cselib_expand_callback, void *);
extern rtx cselib_subst_to_values (rtx, machine_mode);
extern rtx cselib_subst_to_values_from_insn (rtx, machine_mode, rtx_insn *);
extern void cselib_invalidate_rtx (rtx);
extern void cselib_reset_table (unsigned int);
extern unsigned int cselib_get_next_uid (void);
extern void cselib_preserve_value (cselib_val *);
extern bool cselib_preserved_value_p (cselib_val *);
extern void cselib_preserve_only_values (void);
extern void cselib_preserve_cfa_base_value (cselib_val *, unsigned int);
extern void cselib_add_permanent_equiv (cselib_val *, rtx, rtx_insn *);
extern bool cselib_have_permanent_equivalences (void);
extern void cselib_set_value_sp_based (cselib_val *);
extern bool cselib_sp_based_value_p (cselib_val *);
extern void dump_cselib_table (FILE *);
/* Return the canonical value for VAL, following the equivalence chain
towards the earliest (== lowest uid) equivalent value. */
static inline cselib_val *
canonical_cselib_val (cselib_val *val)
{
cselib_val *canon;
if (!val->locs || val->locs->next
|| !val->locs->loc || GET_CODE (val->locs->loc) != VALUE
|| val->uid < CSELIB_VAL_PTR (val->locs->loc)->uid)
return val;
canon = CSELIB_VAL_PTR (val->locs->loc);
gcc_checking_assert (canonical_cselib_val (canon) == canon);
return canon;
}
/* Return nonzero if we can prove that X and Y contain the same value, taking
our gathered information into account. */
static inline int
rtx_equal_for_cselib_p (rtx x, rtx y)
{
if (x == y)
return 1;
return rtx_equal_for_cselib_1 (x, y, VOIDmode, 0);
}
#endif /* GCC_CSELIB_H */