From 83cfc94563c3f5eb0339f4cab280e5219a179a0c Mon Sep 17 00:00:00 2001 From: nobu Date: Tue, 2 Aug 2016 12:40:51 +0000 Subject: [PATCH] math.c: tanh overflow * math.c (tanh): check overflows, and return +-1.0. git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55798 b2dd03c8-39d4-4d8f-98ff-823fe69b080e --- math.c | 4 +++- test/ruby/test_math.rb | 2 ++ 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/math.c b/math.c index a781167d5e..eefcec3c93 100644 --- a/math.c +++ b/math.c @@ -283,7 +283,9 @@ math_sinh(VALUE obj, VALUE x) double tanh(double x) { - return sinh(x) / cosh(x); + const double c = cosh(x); + if (!isinf(c)) return sinh(x) / c; + return x > 0 ? 1.0 : -1.0; } #endif diff --git a/test/ruby/test_math.rb b/test/ruby/test_math.rb index ac9ab3c961..f226287442 100644 --- a/test/ruby/test_math.rb +++ b/test/ruby/test_math.rb @@ -111,6 +111,8 @@ class TestMath < Test::Unit::TestCase check(Math.sinh(0) / Math.cosh(0), Math.tanh(0)) check(Math.sinh(1) / Math.cosh(1), Math.tanh(1)) check(Math.sinh(2) / Math.cosh(2), Math.tanh(2)) + check(+1.0, Math.tanh(+1000.0)) + check(-1.0, Math.tanh(-1000.0)) end def test_acosh