From: "kosaki (Motohiro KOSAKI)" <kosaki.motohiro@...>
Date: 2013-03-27T11:46:51+09:00
Subject: [ruby-core:53761] [ruby-trunk - Bug #7984] Severe speed issues in 2.0.0 compiled with Clang


Issue #7984 has been updated by kosaki (Motohiro KOSAKI).


sorry, my previous mail has a typo. I've measured them again.

-------------------------------------
% ruby -v ../test63.rb  
ruby 1.9.3p392 (2013-02-22 revision 39386) [x86_64-linux]
  3.460000   0.000000   3.460000 (  3.458038)

% ruby -v ../test63.rb
ruby 2.0.0p0 (2013-02-24 revision 39474) [x86_64-linux]
  3.820000   0.000000   3.820000 (  3.811076)

% ruby -v ../test63.rb
ruby 2.1.0dev (2013-03-20 trunk 39832) [x86_64-linux]
  3.290000   0.000000   3.290000 (  3.289948)


----------------------------------------
Bug #7984: Severe speed issues in 2.0.0 compiled with Clang
https://bugs.ruby-lang.org/issues/7984#change-37958

Author: jcole1989 (James Coleman)
Status: Open
Priority: Normal
Assignee: 
Category: 
Target version: 
ruby -v: 2.0.0p0 on darwin


I've been comparing Ruby 2.0.0 with 1.9.3-head, both compiled with the same basic set of CFLAGs with Clang on Mac OS 10.8 (Mountain Lion). A decent sized rails app was showing performance degradations, so I looked into the most basic of (micro)benchmarks. Running the following:

t = Benchmark.measure do
  50000000.times { Object.new }
end

Gives me the following output:

1.9.3-head: 11.240000 0.000000 11.240000 ( 11.247285)
2.0.0p0: 23.610000 0.010000 23.620000 ( 23.629643)

Ruby 2.0.0 takes over twice as long as 1.9.3. In contrast, running the same test under rubies compiled with GCC on linux (unfortunately I can't do a direct test on OSX because 2.0.0 currently won't compile under the current apple gcc 4.2) Ruby 2.0.0 shows a 15-20% speed improvement over 1.9.3.

So it seems there's a severe speed regression interaction with the ruby 2.0.0 code and Clang.


-- 
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