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author | nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2016-08-02 12:42:42 +0000 |
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committer | nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2016-08-02 12:42:42 +0000 |
commit | 4483d59fbdb9f62ec7ddff9c1acc8af907fca72f (patch) | |
tree | 062864922f4a5c2f1d9a3b3eaf1bedf1aaad79ba | |
parent | 83cfc94563c3f5eb0339f4cab280e5219a179a0c (diff) |
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
-rw-r--r-- | ChangeLog | 5 | ||||
-rw-r--r-- | math.c | 5 |
2 files changed, 10 insertions, 0 deletions
@@ -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 @@ -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 |