verify: new macro 'assume'

[gnulib.git] / lib / frexpl.c

diff --git a/lib/frexpl.c b/lib/frexpl.c
index a3c4dc0..5ec2780 100644 (file)
--- a/lib/frexpl.c
+++ b/lib/frexpl.c
@@ -1,101 +1,35 @@
-/* Emulation for frexpl.
-   Contributed by Paolo Bonzini
+/* Split a 'long double' into fraction and mantissa.
+   Copyright (C) 2007, 2009-2013 Free Software Foundation, Inc.
 
-   Copyright 2002, 2003 Free Software Foundation, Inc.
-
-   This file is part of gnulib.
-
-   This program is free software; you can redistribute it and/or modify
+   This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
-   the Free Software Foundation; either version 2, or (at your option)
-   any later version.
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
 
-   You should have received a copy of the GNU General Public License along
-   with this program; if not, write to the Free Software Foundation,
-   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
-#include <float.h>
-#include <math.h>
+#include <config.h>
 
-#include "mathl.h"
+#if HAVE_SAME_LONG_DOUBLE_AS_DOUBLE
+
+/* Specification.  */
+# include <math.h>
 
-/* Binary search.  Quite inefficient but portable. */
 long double
-frexpl(long double x, int *exp)
+frexpl (long double x, int *expptr)
 {
-  long double exponents[20], *next;
-  int exponent, bit;
-
-  /* Check for zero, nan and infinity. */
-  if (x != x || x + x == x )
-    {
-      *exp = 0;
-      return x;
-    }
-
-  if (x < 0)
-    return -frexpl(-x, exp);
-
-  exponent = 0;
-  if (x > 1.0)
-    {
-      for (next = exponents, exponents[0] = 2.0L, bit = 1;
-          *next <= x + x;
-          bit <<= 1, next[1] = next[0] * next[0], next++);
-
-      for (; next >= exponents; bit >>= 1, next--)
-       if (x + x >= *next)
-         {
-           x /= *next;
-           exponent |= bit;
-         }
-
-    }
-
-  else if (x < 0.5)
-    {
-      for (next = exponents, exponents[0] = 0.5L, bit = 1;
-          *next > x;
-          bit <<= 1, next[1] = next[0] * next[0], next++);
-
-      for (; next >= exponents; bit >>= 1, next--)
-       if (x < *next)
-         {
-           x /= *next;
-           exponent |= bit;
-         }
+  return frexp (x, expptr);
+}
 
-      exponent = -exponent;
-    }
+#else
 
-  *exp = exponent;
-  return x;
-}
+# define USE_LONG_DOUBLE
+# include "frexp.c"
 
-#if 0
-int
-main (void)
-{
-  long double x;
-  int y;
-  x = frexpl(0.0L / 0.0L, &y); printf ("%.6Lg %d\n", x, y);
-  x = frexpl(1.0L / 0.0L, &y); printf ("%.6Lg %d\n", x, y);
-  x = frexpl(-1.0L / 0.0L, &y); printf ("%.6Lg %d\n", x, y);
-  x = frexpl(0.5L, &y); printf ("%.6Lg %d\n", x, y);
-  x = frexpl(0.75L, &y); printf ("%.6Lg %d\n", x, y);
-  x = frexpl(3.6L, &y); printf ("%.6Lg %d\n", x, y);
-  x = frexpl(17.8L, &y); printf ("%.6Lg %d\n", x, y);
-  x = frexpl(8.0L, &y); printf ("%.6Lg %d\n", x, y);
-  x = frexpl(0.3L, &y); printf ("%.6Lg %d\n", x, y);
-  x = frexpl(0.49L, &y); printf ("%.6Lg %d\n", x, y);
-  x = frexpl(0.049L, &y); printf ("%.6Lg %d\n", x, y);
-  x = frexpl(0.0245L, &y); printf ("%.6Lg %d\n", x, y);
-  x = frexpl(0.0625L, &y); printf ("%.6Lg %d\n", x, y);
-}
 #endif
-