contrib/gmp/mpf/cmp_d.c

   1 /* mpf_cmp_d -- compare mpf and double.
   2
   3 Copyright 2001, 2003 Free Software Foundation, Inc.
   4
   5 This file is part of the GNU MP Library.
   6
   7 The GNU MP Library is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU Lesser General Public License as published by
   9 the Free Software Foundation; either version 3 of the License, or (at your
  10 option) any later version.
  11
  12 The GNU MP Library is distributed in the hope that it will be useful, but
  13 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  14 or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  15 License for more details.
  16
  17 You should have received a copy of the GNU Lesser General Public License
  18 along with the GNU MP Library.  If not, see http://www.gnu.org/licenses/.  */
  19
  20 #include "config.h"
  21
  22 #if HAVE_FLOAT_H
  23 #include <float.h>  /* for DBL_MAX */
  24 #endif
  25
  26 #include "gmp.h"
  27 #include "gmp-impl.h"
  28
  29 int
  30 mpf_cmp_d (mpf_srcptr f, double d)
  31 {
  32   mp_limb_t  darray[LIMBS_PER_DOUBLE];
  33   mpf_t      df;
  34
  35   /* d=NaN has no sensible return value, so raise an exception.
  36      d=Inf or -Inf is always bigger than z.  */
  37   DOUBLE_NAN_INF_ACTION (d,
  38                          __gmp_invalid_operation (),
  39                          return (d < 0.0 ? 1 : -1));
  40
  41   if (d == 0.0)
  42     return SIZ(f);
  43
  44   PTR(df) = darray;
  45   SIZ(df) = (d >= 0.0 ? LIMBS_PER_DOUBLE : -LIMBS_PER_DOUBLE);
  46   EXP(df) = __gmp_extract_double (darray, ABS(d));
  47
  48   return mpf_cmp (f, df);
  49 }