gcc/tree-vrp.h

   1 /* Support routines for Value Range Propagation (VRP).
   2    Copyright (C) 2016 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 /* Type of value ranges.  See value_range_d In tree-vrp.c for a
  21    description of these types.  */
  22 enum value_range_type { VR_UNDEFINED, VR_RANGE,
  23                         VR_ANTI_RANGE, VR_VARYING, VR_LAST };
  24
  25 /* Range of values that can be associated with an SSA_NAME after VRP
  26    has executed.  */
  27 struct GTY(()) value_range
  28 {
  29   /* Lattice value represented by this range.  */
  30   enum value_range_type type;
  31
  32   /* Minimum and maximum values represented by this range.  These
  33      values should be interpreted as follows:
  34
  35         - If TYPE is VR_UNDEFINED or VR_VARYING then MIN and MAX must
  36           be NULL.
  37
  38         - If TYPE == VR_RANGE then MIN holds the minimum value and
  39           MAX holds the maximum value of the range [MIN, MAX].
  40
  41         - If TYPE == ANTI_RANGE the variable is known to NOT
  42           take any values in the range [MIN, MAX].  */
  43   tree min;
  44   tree max;
  45
  46   /* Set of SSA names whose value ranges are equivalent to this one.
  47      This set is only valid when TYPE is VR_RANGE or VR_ANTI_RANGE.  */
  48   bitmap equiv;
  49 };
  50
  51 extern void vrp_intersect_ranges (value_range *vr0, value_range *vr1);
  52 extern void vrp_meet (value_range *vr0, const value_range *vr1);
  53 extern void dump_value_range (FILE *, const value_range *);
  54 extern void extract_range_from_unary_expr (value_range *vr,
  55                                            enum tree_code code,
  56                                            tree type,
  57                                            value_range *vr0_,
  58                                            tree op0_type);
  59