gcc/cselib.h

   1 /* Common subexpression elimination for GNU compiler.
   2    Copyright (C) 1987, 88, 89, 92-7, 1998, 1999 Free Software Foundation, Inc.
   3
   4 This file is part of GNU CC.
   5
   6 GNU CC is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU CC is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU CC; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 59 Temple Place - Suite 330,
  19 Boston, MA 02111-1307, USA.  */
  20
  21 /* Describe a value.  */
  22 typedef struct cselib_val_struct
  23 {
  24   /* The hash value.  */
  25   unsigned int value;
  26   union
  27   {
  28     /* A VALUE rtx that points back to this structure.  */
  29     rtx val_rtx;
  30     /* Used to keep a list of free cselib_val structures.  */
  31     struct cselib_val_struct *next_free;
  32   } u;
  33
  34   /* All rtl expressions that hold this value at the current time during a
  35      scan.  */
  36   struct elt_loc_list *locs;
  37   /* If this value is used as an address, points to a list of values that
  38      use it as an address in a MEM.  */
  39   struct elt_list *addr_list;
  40 } cselib_val;
  41
  42 /* A list of rtl expressions that hold the same value.  */
  43 struct elt_loc_list
  44 {
  45   /* Next element in the list.  */
  46   struct elt_loc_list *next;
  47   /* An rtl expression that holds the value.  */
  48   rtx loc;
  49   /* The insn that made the equivalence.  */
  50   rtx setting_insn;
  51 };
  52
  53 /* A list of cselib_val structures.  */
  54 struct elt_list
  55 {
  56   struct elt_list *next;
  57   cselib_val *elt;
  58 };
  59
  60 extern cselib_val *cselib_lookup        PARAMS ((rtx, enum machine_mode, int));
  61 extern void cselib_update_varray_sizes  PARAMS ((void));
  62 extern void cselib_init                 PARAMS ((void));
  63 extern void cselib_finish               PARAMS ((void));
  64 extern void cselib_process_insn         PARAMS ((rtx));
  65 extern int rtx_equal_for_cselib_p       PARAMS ((rtx, rtx));
  66 extern int references_value_p           PARAMS ((rtx, int));