X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fldexpl.c;h=4389f761b2442169d409ccb04bfee067fa4e4e47;hb=b94f2b3ac7049ef66bded4596431c453e3710209;hp=cd9bd21d490c49b62d73f4682b6194c81a9c1987;hpb=5657b2536d242966c41c268b9ab4fe8df727bb13;p=gnulib.git
diff --git a/lib/ldexpl.c b/lib/ldexpl.c
index cd9bd21d4..4389f761b 100644
--- a/lib/ldexpl.c
+++ b/lib/ldexpl.c
@@ -1,63 +1,77 @@
/* Emulation for ldexpl.
Contributed by Paolo Bonzini
- Copyright 2002, 2003 Free Software Foundation, Inc.
+ Copyright 2002-2003, 2007-2011 Free Software Foundation, Inc.
This file is part of gnulib.
- gnulib is free software; you can redistribute it and/or modify it
- under the terms of the GNU Lesser General Public License as published
- by the Free Software Foundation; either version 2.1, or (at your option)
- any later version.
+ 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 3 of the License, or
+ (at your option) any later version.
- gnulib 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 Lesser General Public
- License for more details.
+ 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 Lesser General Public License
- along with gnulib; see the file COPYING.LIB. If not, write to the Free
- Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
- USA.
- */
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see . */
-#include
+#include
+
+/* Specification. */
#include
-#include "mathl.h"
+#include
+#include "fpucw.h"
long double
-ldexpl(long double x, int exp)
+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;
}
#if 0
int
-main()
+main (void)
{
long double x;
int y;
for (y = 0; y < 29; y++)
- printf ("%5d %.16Lg %.16Lg\n", y, ldexpl(0.8L, y), ldexpl(0.8L, -y) * ldexpl(0.8L, y));
+ printf ("%5d %.16Lg %.16Lg\n", y, ldexpl (0.8L, y), ldexpl (0.8L, -y) * ldexpl (0.8L, y));
}
#endif