Fix problem with getdate on mingw32 reported by Simon Josefsson

[gnulib.git] / lib / ldexpl.c

diff --git a/lib/ldexpl.c b/lib/ldexpl.c
index 6ad886a..6047413 100644 (file)
--- a/lib/ldexpl.c
+++ b/lib/ldexpl.c
@@ -5,19 +5,18 @@
 
    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 <config.h>
 
@@ -25,28 +24,44 @@
 #include <math.h>
 
 #include <float.h>
+#include "fpucw.h"
+#include "isnanl.h"
 
 long double
 ldexpl(long double x, int exp)
 {
   long double factor;
   int bit;
+  DECL_LONG_DOUBLE_ROUNDING
 
-  /* Check for zero, nan and infinity. */
-  if (x != x || x + x == x )
-    return x;
+  BEGIN_LONG_DOUBLE_ROUNDING ();
 
-  if (exp < 0)
+  /* Check for zero, nan and infinity. */
+  if (!(isnanl (x) || x + x == x))
     {
-      exp = -exp;
-      factor = 0.5L;
+      if (exp < 0)
+       {
+         exp = -exp;
+         factor = 0.5L;
+       }
+      else
+       factor = 2.0L;
+
+      if (exp > 0)
+       for (bit = 1;;)
+         {
+           /* Invariant: Here bit = 2^i, factor = 2^-2^i or = 2^2^i,
+              and bit <= exp.  */
+           if (exp & bit)
+             x *= factor;
+           bit <<= 1;
+           if (bit > exp)
+             break;
+           factor = factor * factor;
+         }
     }
-  else
-    factor = 2.0L;
 
-  for (bit = 1; bit <= exp; bit <<= 1, factor *= factor)
-    if (exp & bit)
-      x *= factor;
+  END_LONG_DOUBLE_ROUNDING ();
 
   return x;
 }