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math.c: faster tanh

* math.c (tanh): make faster by the extract form if three
  hyperbolic functions are unavailable.  [Feature #12647]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55799 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
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nobu 2016-08-02 12:42:42 +00:00
parent 83cfc94563
commit 4483d59fbd
2 changed files with 10 additions and 0 deletions

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@ -1,3 +1,8 @@
Tue Aug 2 21:42:40 2016 Chia-sheng Chen <qitar888@gmail.com>
* math.c (tanh): make faster by the extract form if three
hyperbolic functions are unavailable. [Feature #12647]
Tue Aug 2 12:37:00 2016 Nobuyoshi Nakada <nobu@ruby-lang.org>
* ext/socket/option.c, ext/socket/rubysocket.h (inet_ntop): share

5
math.c
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@ -283,8 +283,13 @@ math_sinh(VALUE obj, VALUE x)
double
tanh(double x)
{
# if defined(HAVE_SINH) && defined(HAVE_COSH)
const double c = cosh(x);
if (!isinf(c)) return sinh(x) / c;
# else
const double e = exp(x+x);
if (!isinf(e)) return (e - 1) / (e + 1);
# endif
return x > 0 ? 1.0 : -1.0;
}
#endif