gcc/tree-vrp.h

   1 /* Support routines for Value Range Propagation (VRP).
   2    Copyright (C) 2016-2017 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC 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 3, or (at your option)
   9 any later version.
  10
  11 GCC 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 GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 #ifndef GCC_TREE_VRP_H
  21 #define GCC_TREE_VRP_H
  22
  23 /* Type of value ranges.  See value_range below for a
  24    description of these types.  */
  25 enum value_range_type { VR_UNDEFINED, VR_RANGE,
  26                         VR_ANTI_RANGE, VR_VARYING, VR_LAST };
  27
  28 /* Range of values that can be associated with an SSA_NAME after VRP
  29    has executed.  */
  30 struct GTY((for_user)) value_range
  31 {
  32   /* Lattice value represented by this range.  */
  33   enum value_range_type type;
  34
  35   /* Minimum and maximum values represented by this range.  These
  36      values should be interpreted as follows:
  37
  38         - If TYPE is VR_UNDEFINED or VR_VARYING then MIN and MAX must
  39           be NULL.
  40
  41         - If TYPE == VR_RANGE then MIN holds the minimum value and
  42           MAX holds the maximum value of the range [MIN, MAX].
  43
  44         - If TYPE == ANTI_RANGE the variable is known to NOT
  45           take any values in the range [MIN, MAX].  */
  46   tree min;
  47   tree max;
  48
  49   /* Set of SSA names whose value ranges are equivalent to this one.
  50      This set is only valid when TYPE is VR_RANGE or VR_ANTI_RANGE.  */
  51   bitmap equiv;
  52 };
  53
  54 extern void vrp_intersect_ranges (value_range *vr0, value_range *vr1);
  55 extern void vrp_meet (value_range *vr0, const value_range *vr1);
  56 extern void dump_value_range (FILE *, const value_range *);
  57 extern void extract_range_from_unary_expr (value_range *vr,
  58                                            enum tree_code code,
  59                                            tree type,
  60                                            value_range *vr0_,
  61                                            tree op0_type);
  62
  63 #endif /* GCC_TREE_VRP_H */