gcc/cselib.h

   1 /* Common subexpression elimination for GNU compiler.
   2    Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
   3    1999, 2003, 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 3, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 /* Describe a value.  */
  22 typedef struct GTY(()) cselib_val_struct {
  23   /* The hash value.  */
  24   unsigned int value;
  25
  26   /* A VALUE rtx that points back to this structure.  */
  27   rtx val_rtx;
  28
  29   /* All rtl expressions that hold this value at the current time during a
  30      scan.  */
  31   struct elt_loc_list *locs;
  32
  33   /* If this value is used as an address, points to a list of values that
  34      use it as an address in a MEM.  */
  35   struct elt_list *addr_list;
  36
  37   struct cselib_val_struct *next_containing_mem;
  38 } cselib_val;
  39
  40 /* A list of rtl expressions that hold the same value.  */
  41 struct GTY(()) elt_loc_list {
  42   /* Next element in the list.  */
  43   struct elt_loc_list *next;
  44   /* An rtl expression that holds the value.  */
  45   rtx loc;
  46   /* The insn that made the equivalence.  */
  47   rtx setting_insn;
  48 };
  49
  50 /* A list of cselib_val structures.  */
  51 struct GTY(()) elt_list {
  52   struct elt_list *next;
  53   cselib_val *elt;
  54 };
  55
  56 /* Describe a single set that is part of an insn.  */
  57 struct cselib_set
  58 {
  59   rtx src;
  60   rtx dest;
  61   cselib_val *src_elt;
  62   cselib_val *dest_addr_elt;
  63 };
  64
  65 extern void (*cselib_discard_hook) (cselib_val *);
  66 extern void (*cselib_record_sets_hook) (rtx insn, struct cselib_set *sets,
  67                                         int n_sets);
  68
  69 extern cselib_val *cselib_lookup (rtx, enum machine_mode, int);
  70 extern void cselib_init (bool record_memory);
  71 extern void cselib_clear_table (void);
  72 extern void cselib_finish (void);
  73 extern void cselib_process_insn (rtx);
  74 extern enum machine_mode cselib_reg_set_mode (const_rtx);
  75 extern int rtx_equal_for_cselib_p (rtx, rtx);
  76 extern int references_value_p (const_rtx, int);
  77 extern rtx cselib_expand_value_rtx (rtx, bitmap, int);
  78 typedef rtx (*cselib_expand_callback)(rtx, bitmap, int, void *);
  79 extern rtx cselib_expand_value_rtx_cb (rtx, bitmap, int,
  80                                        cselib_expand_callback, void*);
  81 extern rtx cselib_subst_to_values (rtx);
  82 extern void cselib_invalidate_rtx (rtx);
  83
  84 extern void cselib_reset_table_with_next_value (unsigned int);
  85 extern unsigned int cselib_get_next_unknown_value (void);
  86 extern void cselib_preserve_value (cselib_val *);
  87 extern bool cselib_preserved_value_p (cselib_val *);
  88 extern void cselib_preserve_only_values (bool);
  89
  90 extern void dump_cselib_table (FILE *);