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authorUlrich Drepper <drepper@gmail.com>2011-10-12 11:27:51 -0400
committerUlrich Drepper <drepper@gmail.com>2011-10-12 11:27:51 -0400
commit0ac5ae2335292908f39031b1ea9fe8edce433c0f (patch)
treef9d26c8abc0de39d18d4c13e70f6022cdc6b461f /math/w_log2l.c
parenta843a204a3e8a0dd53584dad3668771abaec84ac (diff)
downloadglibc-0ac5ae2335292908f39031b1ea9fe8edce433c0f.tar.gz
Optimize libm
libm is now somewhat integrated with gcc's -ffinite-math-only option and lots of the wrapper functions have been optimized.
Diffstat (limited to 'math/w_log2l.c')
-rw-r--r--math/w_log2l.c51
1 files changed, 34 insertions, 17 deletions
diff --git a/math/w_log2l.c b/math/w_log2l.c
index ff7ba2621e..f589768b15 100644
--- a/math/w_log2l.c
+++ b/math/w_log2l.c
@@ -1,28 +1,45 @@
-/*
- * wrapper log2l(X)
- */
+/* Copyright (C) 2011 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Ulrich Drepper <drepper@gmail.com>, 2011.
+ The GNU C Library 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 of the License, or (at your option) any later version.
+
+ The GNU C Library 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.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <fenv.h>
#include <math.h>
#include <math_private.h>
+
+/* wrapper log2l(x) */
long double
-__log2l (long double x) /* wrapper log2l */
+__log2l (long double x)
{
-#ifdef _IEEE_LIBM
- return __ieee754_log2l (x);
-#else
- long double z;
- z = __ieee754_log2l (x);
- if (_LIB_VERSION == _IEEE_ || __isnanl (x)) return z;
- if (x <= 0.0)
+ if (__builtin_expect (x <= 0.0L, 0) && _LIB_VERSION != _IEEE_)
{
- if (x == 0.0)
- return __kernel_standard (x, x, 248); /* log2l (0) */
+ if (x == 0.0L)
+ {
+ feraiseexcept (FE_DIVBYZERO);
+ return __kernel_standard (x, x, 248); /* log2(0) */
+ }
else
- return __kernel_standard (x, x, 249); /* log2l (x < 0) */
+ {
+ feraiseexcept (FE_INVALID);
+ return __kernel_standard (x, x, 249); /* log2(x<0) */
+ }
}
- else
- return z;
-#endif
+
+ return __ieee754_log2l (x);
}
weak_alias (__log2l, log2l)