diff options
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 /math.c | |
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
Diffstat (limited to 'math.c')
-rw-r--r-- | math.c | 5 |
1 files changed, 5 insertions, 0 deletions
@@ -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 |