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 Free Software Foundation, Inc.
   4
   5 This file is part of GNU CC.
   6
   7 GNU CC is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2, or (at your option)
  10 any later version.
  11
  12 GNU CC is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU CC; see the file COPYING.  If not, write to
  19 the Free Software Foundation, 59 Temple Place - Suite 330,
  20 Boston, MA 02111-1307, USA.  */
  21
  22 /* Describe a value.  */
  23 typedef struct cselib_val_struct
  24 {
  25   /* The hash value.  */
  26   unsigned int value;
  27   union
  28   {
  29     /* A VALUE rtx that points back to this structure.  */
  30     rtx val_rtx;
  31     /* Used to keep a list of free cselib_val structures.  */
  32     struct cselib_val_struct *next_free;
  33   } u;
  34
  35   /* All rtl expressions that hold this value at the current time during a
  36      scan.  */
  37   struct elt_loc_list *locs;
  38   /* If this value is used as an address, points to a list of values that
  39      use it as an address in a MEM.  */
  40   struct elt_list *addr_list;
  41 } cselib_val;
  42
  43 /* A list of rtl expressions that hold the same value.  */
  44 struct elt_loc_list
  45 {
  46   /* Next element in the list.  */
  47   struct elt_loc_list *next;
  48   /* An rtl expression that holds the value.  */
  49   rtx loc;
  50   /* The insn that made the equivalence.  */
  51   rtx setting_insn;
  52 };
  53
  54 /* A list of cselib_val structures.  */
  55 struct elt_list
  56 {
  57   struct elt_list *next;
  58   cselib_val *elt;
  59 };
  60
  61 extern cselib_val *cselib_lookup        PARAMS ((rtx, enum machine_mode, int));
  62 extern void cselib_update_varray_sizes  PARAMS ((void));
  63 extern void cselib_init                 PARAMS ((void));
  64 extern void cselib_finish               PARAMS ((void));
  65 extern void cselib_process_insn         PARAMS ((rtx));
  66 extern int rtx_equal_for_cselib_p       PARAMS ((rtx, rtx));
  67 extern int references_value_p           PARAMS ((rtx, int));