[Python-Dev] -O2 faster than -O3?

Steve Holden steve at holdenweb.com
Sat Dec 1 07:50:19 CET 2007

Neil Toronto wrote:
> If you're going to run these benchmarks yourself, make sure you "make 
> clean" before building with different options. (I don't know why it's 
> necessary, but it is.) 

Because the dependencies evaluated by "make" don't take into account the 
different options that were used to compile existing object files.

Without the "make clean" it says "aha, here's a nice up-to-date object 
file, I'll use that" and you don't get a freshly-compiled version.

Touching the sources should also work, and is a little quicker.

Steve Holden        +1 571 484 6266   +1 800 494 3119
Holden Web LLC              http://www.holdenweb.com/

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