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authorSergey Cherkashin <4erkashin@list.ru>2017-10-03 15:26:34 +0300
committerWaldemar Brodkorb <wbx@uclibc-ng.org>2017-11-03 20:23:10 +0100
commitea38f4d89c9698895b1cf53a5946429dc1d8bbaa (patch)
treee05828ca1fedf55f104b837bc9c44215c2978e99 /libm/w_exp2.c
parent68de9946e914d8c30dcc6667a059ea59e5b74cac (diff)
math: add exception handling functionality
According to standards SVID and SYSV. Modified lgamma calling in case when 'signgam' variable should not be used. Signed-off-by: Waldemar Brodkorb <wbx@uclibc-ng.org>
Diffstat (limited to 'libm/w_exp2.c')
-rw-r--r--libm/w_exp2.c45
1 files changed, 32 insertions, 13 deletions
diff --git a/libm/w_exp2.c b/libm/w_exp2.c
index e00277abf..1215c2e92 100644
--- a/libm/w_exp2.c
+++ b/libm/w_exp2.c
@@ -1,19 +1,38 @@
-/*
- * ====================================================
- * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
- *
- * Developed at SunPro, a Sun Microsystems, Inc. business.
- * Permission to use, copy, modify, and distribute this
- * software is freely granted, provided that this notice
- * is preserved.
- * ====================================================
- */
+/* Copyright (C) 2011-2016 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Ulrich Drepper <drepper@gmail.com>, 2011.
-#include "math.h"
+ 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, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <math.h>
#include "math_private.h"
-double exp2(double x)
+/* wrapper exp2(x) */
+double
+exp2 (double x)
{
- return pow(2.0, x);
+#if __UCLIBC_HAS_FENV__
+ double z = pow(2.0, x);
+ if (__builtin_expect (!isfinite (z) || z == 0, 0)
+ && isfinite (x) && _LIB_VERSION != _IEEE_)
+ /* exp2 overflow: 44, exp2 underflow: 45 */
+ return __kernel_standard (x, x, 44 + !!signbit (x));
+
+ return z;
+#else
+ return pow(2.0, x);
+#endif
}
libm_hidden_def(exp2)