-On [20080413 00:47], Gregory P. Smith ([EMAIL PROTECTED]) wrote: >With gcc 4.1.3 i'm finding that profile guided optimization when trained on >pybench or regrtest does make a measurable difference (2-5% overall time with >10-20% on some pybench tests). I haven't run benchmarks enough times to be >confident in my results yet, I'll report back with data once I have it. I'm >testing both pybench and regrtest as profiling training runs.
It seems GCC 4.2.4 yields worse code for Python with the same options as 4.2.1, I measured about ~7%-8% slowdown (~0,5 seconds) on my test. Granted, in general this might all be nitpicking, but for our friends in the calculating departments this might be quite useful to know. The differences are in general not concentrated in specific sections of pybench, but are uniformly distributed. I know my employer can use such additional free optimizations since our jobs spawn in many hours of execution. Next to optimizing the source code, of course, this will also shave off quite a lot of execution time. >I will check in a special makefile target for easy gcc profile guided compiles >shortly so that those who want faster builds easily produce them. That would be interesting I think. I went with -fprofile-generate and -fprofile-use in my small test. -- Jeroen Ruigrok van der Werven <asmodai(-at-)in-nomine.org> / asmodai イェルーン ラウフロック ヴァン デル ウェルヴェン http://www.in-nomine.org/ | http://www.rangaku.org/ Put your heart, mind, intellect and soul even to your smallest acts. This is the secret of success... _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
