summaryrefslogtreecommitdiff
path: root/libstdc++-v3/include/std/complex
diff options
context:
space:
mode:
authoraldyh <aldyh@138bc75d-0d04-0410-961f-82ee72b054a4>2011-11-08 03:20:30 +0000
committeraldyh <aldyh@138bc75d-0d04-0410-961f-82ee72b054a4>2011-11-08 03:20:30 +0000
commit643df0593c630691fa6877cddeefdd4c3023d444 (patch)
tree1eb48ad31d05a9ce117bedc17115de96dffa2f0b /libstdc++-v3/include/std/complex
parent54f3f029d816c6d1626310649adfda740e203f7b (diff)
parentd5d8f1ccc6d3972dc5cfc0949e85e0b1c9e24ee0 (diff)
downloadgcc-transactional-memory.tar.gz
* Merge from mainline rev 181122.transactional-memory
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/transactional-memory@181148 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'libstdc++-v3/include/std/complex')
-rw-r--r--libstdc++-v3/include/std/complex11
1 files changed, 3 insertions, 8 deletions
diff --git a/libstdc++-v3/include/std/complex b/libstdc++-v3/include/std/complex
index 3c41b483cd2..d7423433803 100644
--- a/libstdc++-v3/include/std/complex
+++ b/libstdc++-v3/include/std/complex
@@ -1686,14 +1686,9 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
std::complex<_Tp>
__complex_acosh(const std::complex<_Tp>& __z)
{
- std::complex<_Tp> __t((__z.real() - __z.imag())
- * (__z.real() + __z.imag()) - _Tp(1.0),
- _Tp(2.0) * __z.real() * __z.imag());
- __t = std::sqrt(__t);
- if (__z.real() < _Tp())
- __t = -__t;
-
- return std::log(__t + __z);
+ // Kahan's formula.
+ return _Tp(2.0) * std::log(std::sqrt(_Tp(0.5) * (__z + _Tp(1.0)))
+ + std::sqrt(_Tp(0.5) * (__z - _Tp(1.0))));
}
#if _GLIBCXX_USE_C99_COMPLEX_TR1