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 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 2, 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 COPYING.  If not, write to the Free
  19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  20 02111-1307, USA.  */
  21
  22 /* Describe a value.  */
  23 typedef struct cselib_val_struct GTY(())
  24 {
  25   /* The hash value.  */
  26   unsigned int value;
  27   union cselib_val_u
  28   {
  29     /* A VALUE rtx that points back to this structure.  */
  30     rtx GTY ((tag ("1"))) val_rtx;
  31     /* Used to keep a list of free cselib_val structures.  */
  32     struct cselib_val_struct * GTY ((skip (""))) next_free;
  33   } GTY ((desc ("1"))) 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 GTY(())
  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 GTY(())
  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));
  68 extern rtx cselib_subst_to_values       PARAMS ((rtx));