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 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
  42   struct cselib_val_struct *next_containing_mem;
  43 } cselib_val;
  44
  45 /* A list of rtl expressions that hold the same value.  */
  46 struct elt_loc_list GTY(())
  47 {
  48   /* Next element in the list.  */
  49   struct elt_loc_list *next;
  50   /* An rtl expression that holds the value.  */
  51   rtx loc;
  52   /* The insn that made the equivalence.  */
  53   rtx setting_insn;
  54   /* True when setting insn is inside libcall.  */
  55   bool in_libcall;
  56 };
  57
  58 /* A list of cselib_val structures.  */
  59 struct elt_list GTY(())
  60 {
  61   struct elt_list *next;
  62   cselib_val *elt;
  63 };
  64
  65 extern cselib_val *cselib_lookup (rtx, enum machine_mode, int);
  66 extern void cselib_init (bool record_memory);
  67 extern void cselib_finish (void);
  68 extern void cselib_process_insn (rtx);
  69 extern enum machine_mode cselib_reg_set_mode (rtx);
  70 extern int rtx_equal_for_cselib_p (rtx, rtx);
  71 extern int references_value_p (rtx, int);
  72 extern rtx cselib_subst_to_values (rtx);