From: "phasis68 (Heesob Park)" <phasis@...>
Date: 2012-04-29T23:06:32+09:00
Subject: [ruby-core:44758] [ruby-trunk - Bug #6370] NaNTest failed for Ruby 1.9.3 P194


Issue #6370 has been updated by phasis68 (Heesob Park).


I can reproduce this issue on GCC 4.7.0 Mingw32.

The optimization flag -Ofast is the root cause of this issue.
Accoring to the manual, -Ofast is same to -O3 and -ffast-math.
And -ffast-math sets -fno-math-errno, -funsafe-math-optimizations, -ffinite-math-only, -fno-rounding-math, -fno-signaling-nans and -fcx-limited-range.

The flag -ffinite-math-only means 
"Allow optimizations for floating-point arithmetic that assume that arguments and results are not NaNs or +-Infs."
So the nan test is not worked as expected.

The workaround is adding -fno-finite-math-only in case of -Ofast flag.


----------------------------------------
Bug #6370: NaNTest failed for Ruby 1.9.3 P194
https://bugs.ruby-lang.org/issues/6370#change-26319

Author: raylinn@gmail.com (ray linn)
Status: Assigned
Priority: Normal
Assignee: luislavena (Luis Lavena)
Category: 
Target version: 
ruby -v: ruby 1.9.3p194 (2012-04-20) [x64-mingw32]


The Ruby 1.9.3 is compibled by GCC 4.7.0 (MinGW64) under Windows64. Configure line is as following:

.configure --build=x86_64-w64-mingw32 CFLAGS="-Ofast -mieee-fp -I/usr/local/include" CPPFLAGS="-Ofast -mieee-fp -I/usr/local/include" LDFLAGS="-L/usr/local/lib"

When compiled complete, run make test, it reports:
not ok float 15 -- C:/msys/1.0/home/beta/ruby-1.9.3-p194/sample/test.rb:1410:in `nan_test'
not ok float 20 -- C:/msys/1.0/home/beta/ruby-1.9.3-p194/sample/test.rb:1410:in `nan_test'
not ok float 25 -- C:/msys/1.0/home/beta/ruby-1.9.3-p194/sample/test.rb:1410:in `nan_test'
not ok float 30 -- C:/msys/1.0/home/beta/ruby-1.9.3-p194/sample/test.rb:1410:in `nan_test'
not ok float 35 -- C:/msys/1.0/home/beta/ruby-1.9.3-p194/sample/test.rb:1410:in `nan_test'
not ok float 40 -- C:/msys/1.0/home/beta/ruby-1.9.3-p194/sample/test.rb:1410:in `nan_test'
not ok float 45 -- C:/msys/1.0/home/beta/ruby-1.9.3-p194/sample/test.rb:1410:in `nan_test'
not ok/test: 903 failed 7

marked these 7 lines could pass the test

#nan_test(nan, 0)
#nan_test(nan, 1)
#nan_test(nan, -1)
#nan_test(nan, 1000)
#nan_test(nan, -1000)
#nan_test(nan, 1_000_000_000_000)
#nan_test(nan, -1_000_000_000_000)




-- 
http://bugs.ruby-lang.org/