141 lines
4.4 KiB
C
141 lines
4.4 KiB
C
/* Common subexpression elimination for GNU compiler.
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Copyright (C) 1987-2019 Free Software Foundation, Inc.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free
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Software Foundation; either version 3, or (at your option) any later
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version.
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GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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for more details.
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You should have received a copy of the GNU General Public License
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along with GCC; see the file COPYING3. If not see
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<http://www.gnu.org/licenses/>. */
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#ifndef GCC_CSELIB_H
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#define GCC_CSELIB_H
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/* Describe a value. */
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struct cselib_val
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{
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/* The hash value. */
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unsigned int hash;
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/* A unique id assigned to values. */
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int uid;
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/* A VALUE rtx that points back to this structure. */
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rtx val_rtx;
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/* All rtl expressions that hold this value at the current time during a
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scan. */
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struct elt_loc_list *locs;
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/* If this value is used as an address, points to a list of values that
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use it as an address in a MEM. */
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struct elt_list *addr_list;
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struct cselib_val *next_containing_mem;
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};
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/* A list of rtl expressions that hold the same value. */
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struct elt_loc_list {
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/* Next element in the list. */
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struct elt_loc_list *next;
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/* An rtl expression that holds the value. */
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rtx loc;
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/* The insn that made the equivalence. */
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rtx_insn *setting_insn;
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};
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/* Describe a single set that is part of an insn. */
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struct cselib_set
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{
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rtx src;
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rtx dest;
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cselib_val *src_elt;
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cselib_val *dest_addr_elt;
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};
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enum cselib_record_what
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{
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CSELIB_RECORD_MEMORY = 1,
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CSELIB_PRESERVE_CONSTANTS = 2
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};
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extern void (*cselib_discard_hook) (cselib_val *);
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extern void (*cselib_record_sets_hook) (rtx_insn *insn, struct cselib_set *sets,
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int n_sets);
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extern cselib_val *cselib_lookup (rtx, machine_mode,
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int, machine_mode);
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extern cselib_val *cselib_lookup_from_insn (rtx, machine_mode,
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int, machine_mode, rtx_insn *);
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extern void cselib_init (int);
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extern void cselib_clear_table (void);
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extern void cselib_finish (void);
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extern void cselib_process_insn (rtx_insn *);
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extern bool fp_setter_insn (rtx_insn *);
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extern machine_mode cselib_reg_set_mode (const_rtx);
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extern int rtx_equal_for_cselib_1 (rtx, rtx, machine_mode, int);
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extern int references_value_p (const_rtx, int);
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extern rtx cselib_expand_value_rtx (rtx, bitmap, int);
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typedef rtx (*cselib_expand_callback)(rtx, bitmap, int, void *);
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extern rtx cselib_expand_value_rtx_cb (rtx, bitmap, int,
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cselib_expand_callback, void *);
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extern bool cselib_dummy_expand_value_rtx_cb (rtx, bitmap, int,
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cselib_expand_callback, void *);
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extern rtx cselib_subst_to_values (rtx, machine_mode);
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extern rtx cselib_subst_to_values_from_insn (rtx, machine_mode, rtx_insn *);
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extern void cselib_invalidate_rtx (rtx, const_rtx = NULL);
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extern void cselib_reset_table (unsigned int);
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extern unsigned int cselib_get_next_uid (void);
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extern void cselib_preserve_value (cselib_val *);
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extern bool cselib_preserved_value_p (cselib_val *);
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extern void cselib_preserve_only_values (void);
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extern void cselib_preserve_cfa_base_value (cselib_val *, unsigned int);
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extern void cselib_add_permanent_equiv (cselib_val *, rtx, rtx_insn *);
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extern bool cselib_have_permanent_equivalences (void);
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extern void cselib_set_value_sp_based (cselib_val *);
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extern bool cselib_sp_based_value_p (cselib_val *);
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extern void dump_cselib_table (FILE *);
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/* Return the canonical value for VAL, following the equivalence chain
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towards the earliest (== lowest uid) equivalent value. */
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static inline cselib_val *
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canonical_cselib_val (cselib_val *val)
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{
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cselib_val *canon;
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if (!val->locs || val->locs->next
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|| !val->locs->loc || GET_CODE (val->locs->loc) != VALUE
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|| val->uid < CSELIB_VAL_PTR (val->locs->loc)->uid)
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return val;
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canon = CSELIB_VAL_PTR (val->locs->loc);
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gcc_checking_assert (canonical_cselib_val (canon) == canon);
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return canon;
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}
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/* Return nonzero if we can prove that X and Y contain the same value, taking
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our gathered information into account. */
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static inline int
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rtx_equal_for_cselib_p (rtx x, rtx y)
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{
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if (x == y)
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return 1;
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return rtx_equal_for_cselib_1 (x, y, VOIDmode, 0);
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}
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#endif /* GCC_CSELIB_H */
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