From: s.wanabe@...
Date: 2014-12-25T07:49:53+00:00
Subject: [ruby-core:67124] [ruby-trunk - Bug #10642] 2.2: TestMath#test_gamma test failure (MinGW)

Issue #10642 has been updated by _ wanabe.


http://sourceforge.net/p/mingw-w64/mingw-w64/ci/8a67ab4541226a80b3ec2047347890d915126de1/tree/mingw-w64-crt/math/tgamma.c#l122
tgamma() of mingw32-w64 is buggy in x > 709.782712893384 because `pow(x, 0.5 * x - 0.25) / exp(x) == Inf / Inf == NaN`.
It doesn't care of `x > 172`.

I guess the ticket should be "3rd party's issue", shouldn't it?
If you're going to insist, how about using missing/tgamma.c on mingw32-w64?

----------------------------------------
Bug #10642: 2.2: TestMath#test_gamma test failure (MinGW)
https://bugs.ruby-lang.org/issues/10642#change-50627

* Author: Luis Lavena
* Status: Assigned
* Priority: Normal
* Assignee: Yui NARUSE
* Category: test
* Target version: current: 2.2.0
* ruby -v: ruby 2.2.0dev (2014-12-24) [i386-mingw32]
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN
----------------------------------------
Hello,

Running tests against ruby_2_2 branch, mingw-w64 4.7.2, Windows 7 x64:

~~~
TestMath#test_gamma [C:/Users/Luis/Code/ruby/ruby/test/ruby/test_math.rb:237]:
Math.gamma(2147483648) should be INF.
Expected NaN to be infinite?.
~~~



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