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>

1 files changed, 46 insertions, 0 deletions

diff --git a/libm/w_atan2.c b/libm/w_atan2.c
new file mode 100644
index 000000000..0c036e6ca
--- /dev/null
+++ b/libm/w_atan2.c
@@ -0,0 +1,46 @@
+/* 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.
+
+   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/>.  */
+
+/*
+ * wrapper atan2(y,x)
+ */
+
+#include <math.h>
+#include "math_private.h"
+#if __UCLIBC_HAS_FENV__
+#include <errno.h>
+#endif
+
+double
+atan2 (double y, double x)
+{
+#if __UCLIBC_HAS_FENV__
+  double z;
+
+  if (__builtin_expect (x == 0.0 && y == 0.0, 0) && _LIB_VERSION == _SVID_)
+    return __kernel_standard (y, x, 3); /* atan2(+-0,+-0) */
+
+  z = __ieee754_atan2 (y, x);
+  if (__builtin_expect (z == 0.0 && y != 0.0 && isfinite (x),0))
+    __set_errno (ERANGE);
+  return z;
+#else
+  return __ieee754_atan2 (y, x);
+#endif
+}
+libm_hidden_def(atan2)
\ No newline at end of file