Re^4: perllVm: A Linux test of how Perl and LLVM would work together.

[flexvault]

in reply to Re^3: perllVm: A Linux test of how Perl and LLVM would work together.
in thread perllVm: A Linux test of how Perl and LLVM would work together.

chromatic,

...at a few percentage points improvement from clang optimizations versus gcc optimizations

I re-read your post, and just to clarify what I was talking about.

The 15% improvement was comparing the original Perl5.16.0 compiled with '-O2' and the new Perl5.16.0 (perllvm) compiled with '-O3', and not the incremental re-running of the script.

• 'GCC' '-O2' was 'perl5.16.0 -sw BrowserUK_991333.pl 3 9' -> Took: 15.2425358295441
• 'clang' '-O3' was 'perllvm -sw BrowserUK_991333.pl 3 9' -> Took: 13.2621982097626

And by dividing the 'GCC' time by 'clang' time, I got 1.149.

But now I realized I compared '-O2' to '-O3' ( which could be the cause of any increase). So I went back and compiled 'GCC' with '-O3', but the Perl 'Configure' changed it to '-O2', so I couldn't compare apples to apples anyway. 'Configure' did allow the '-O3' with 'clang' but not with 'GCC'.

I looked at the 'Configure' and it would have to change to add the 'jit' parameters as well, but until I get some feedback from the LLVM developers, it would be a waste of time.

Regards