GCC/CFLAGS Benchmark for HEAD and PHP_5_0

I ran the Zend/bench.php script with PHP 5.0 and PHP 5.1 compiled with GCC 3.3 and GCC 3.4 using different optimizations on my Intel Pentium-M laptop: HEAD (PHP 5.1.0-dev) GCC 3.3.4 (-march=pentium3) -O0: 48.602 -Os: 29.920 -O1: 31.349 -O2: 29.029 -O3: 29.644 GCC 3.4.2 (-march=pentium-m -mtune=pentium-m) -O0: 48.966 -Os: 26.286 -O1: 29.253 -O2: 29.100 -O3: 27.767 -fprofile-{generate|use} -Os: 24.216 -fprofile-{generate|use} -O1: 26.575 -fprofile-{generate|use} -O2: 26.339 -fprofile-{generate|use} -O3: 25.537 PHP_5_0 (PHP 5.0.3-dev) GCC 3.3.4 (-march=pentium3) -O0: 58.394 -Os: 42.570 -O1: 43.454 -O2: 42.092 -O3: 42.066 GCC 3.4.2 (-march=pentium-m -mtune=pentium-m) -O0: 59.272 -Os: 35.853 -O1: 38.275 -O2: 37.989 -O3: 41.020 -fprofile-{generate|use} -Os: 33.926 -fprofile-{generate|use} -O1: 36.853 -fprofile-{generate|use} -O2: 35.335 -fprofile-{generate|use} -O3: 38.897 For the -fprofile-{generate|use} builds I used the Zend/bench.php script, too, to generate the profile information. If we were to add Makefile target (like GCC itself ("make profiled-bootstrap")) to the PHP build that makes use of -fprofile-{generate|use} it would make sense to use "make test" to generate the profiling information. When I find the time I will repeat the benchmark on my AMD Athlon64 box because I think the small L1/L2 caches of the laptop CPU affect the performance of the bigger code generated through optimizations. You can clearly see that code optimized for size (-Os) is faster than the more aggressive -O1, -O2, and -O3 optimization levels.