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      1 /* mpfr_cmp_d -- compare a floating-point number with a long double
      2 
      3 Copyright 2004, 2006-2023 Free Software Foundation, Inc.
      4 Contributed by the AriC and Caramba projects, INRIA.
      5 
      6 This file is part of the GNU MPFR Library.
      7 
      8 The GNU MPFR Library is free software; you can redistribute it and/or modify
      9 it under the terms of the GNU Lesser General Public License as published by
     10 the Free Software Foundation; either version 3 of the License, or (at your
     11 option) any later version.
     12 
     13 The GNU MPFR Library is distributed in the hope that it will be useful, but
     14 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
     15 or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
     16 License for more details.
     17 
     18 You should have received a copy of the GNU Lesser General Public License
     19 along with the GNU MPFR Library; see the file COPYING.LESSER.  If not, see
     20 https://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
     21 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */
     22 
     23 #include <float.h> /* needed so that MPFR_LDBL_MANT_DIG is correctly defined */
     24 
     25 #include "mpfr-impl.h"
     26 
     27 int
     28 mpfr_cmp_ld (mpfr_srcptr b, long double d)
     29 {
     30   mpfr_t tmp;
     31   int res;
     32   MPFR_SAVE_EXPO_DECL (expo);
     33 
     34   MPFR_SAVE_EXPO_MARK (expo);
     35 
     36 #if !HAVE_LDOUBLE_MAYBE_DOUBLE_DOUBLE
     37   mpfr_init2 (tmp, MPFR_LDBL_MANT_DIG);
     38 #else
     39   /* since the smallest value is 2^(-1074) and the largest is < 2^1024,
     40      every double-double is exactly representable with 1024 + 1074 bits */
     41   mpfr_init2 (tmp, 1024 + 1074);
     42 #endif
     43   res = mpfr_set_ld (tmp, d, MPFR_RNDN);
     44   MPFR_ASSERTD (res == 0);
     45 
     46   MPFR_CLEAR_FLAGS ();
     47   res = mpfr_cmp (b, tmp);
     48   MPFR_SAVE_EXPO_UPDATE_FLAGS (expo, __gmpfr_flags);
     49 
     50   mpfr_clear (tmp);
     51   MPFR_SAVE_EXPO_FREE (expo);
     52   return res;
     53 }
     54