J.C. Pizarro wrote: > p7zip-4.57 > [...] > 1. 1m50s compile, 1630164 file, 1618639 text, 6120 data, 27168 bss, 5m50s run. > 2. 1m53s compile, 1665952 file, 1649829 text, 4668 data, 29160 bss, 6m04s run. > 3. 2m08s compile, 1629088 file, 1613313 text, 4672 data, 29160 bss, 5m54s run. > 4. 2m36s compile, 2063216 file, 2047420 text, 4380 data, 29160 bss, 6m14s run. > 5. 2m30s compile, 1976228 file, 1960164 text, 4380 data, 29160 bss, 6m12s run.
Has anybody analyzed this code size and performance regression? For simplicity, we could limit our comparison to 3 (gcc-4.2.4) against 4 (gcc-4.3.0) or 5 (gcc-4.4.0). For the performance regression, one could proceed like this: - profile the 7z run to find the hot-spot(s) - disassemble the output of both compilers - look for obvious pessimizations in the hot parts We're looking for a 6-7% change in time, so it may very well be a single instruction. -- \___/ |___| Bernardo Innocenti - http://www.codewiz.org/ \___\ One Laptop Per Child - http://www.laptop.org/
