gcc/range.cc

   1 /* Misc range functions.
   2    Copyright (C) 2017-2019 Free Software Foundation, Inc.
   3    Contributed by Aldy Hernandez <aldyh@redhat.com>.
   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 3, 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 COPYING3.  If not see
  19 <http://www.gnu.org/licenses/>.  */
  20
  21 #include "config.h"
  22 #include "system.h"
  23 #include "coretypes.h"
  24 #include "backend.h"
  25 #include "tree.h"
  26 #include "gimple.h"
  27 #include "gimple-pretty-print.h"
  28 #include "fold-const.h"
  29 #include "ssa.h"
  30 #include "range.h"
  31
  32 value_range
  33 range_zero (tree type)
  34 {
  35   return value_range (build_zero_cst (type), build_zero_cst (type));
  36 }
  37
  38 value_range
  39 range_nonzero (tree type)
  40 {
  41   return value_range (build_zero_cst (type), build_zero_cst (type),
  42                       VR_ANTI_RANGE);
  43 }
  44
  45 value_range
  46 range_positives (tree type)
  47 {
  48   unsigned prec = TYPE_PRECISION (type);
  49   signop sign = TYPE_SIGN (type);
  50   return value_range (type, wi::zero (prec), wi::max_value (prec, sign));
  51 }
  52
  53 value_range
  54 range_negatives (tree type)
  55 {
  56   unsigned prec = TYPE_PRECISION (type);
  57   signop sign = TYPE_SIGN (type);
  58   value_range r;
  59   if (sign == UNSIGNED)
  60     r.set_undefined ();
  61   else
  62     r = value_range (type, wi::min_value (prec, sign), wi::minus_one (prec));
  63   return r;
  64 }