Pádraig Brady <p...@draigbrady.com> writes: > -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions > -fstack-protector --param=ssp-buffer-size=4 -m32 -march=i586 > -mtune=generic -fasynchronous-unwind-tables -D_GNU_SOURCE=1
thanks. I did again all tests on my machine using these same options. I repeated each test 6 times and I took the median without consider the first result. Except the first run that it is not considered, I didn't report a big variance on results of the same test. gcc 4.3.3 gnulib sha1: real 0m2.543s gnulib sha1 lookup: real 0m1.906s (-25%) linus's sha1: real 0m2.468s (-3%) linus's sha1 no asm: real 0m2.289s (-9%) gcc 4.4.1 gnulib sha1: real 0m3.386s gnulib sha1 lookup: real 0m3.110s (-8%) linus's sha1: real 0m1.701s (-49%) linus's sha1 no asm: real 0m1.284s (-62%) I don't see such big differences in asm generated by gcc 4.4.1 and gcc 4.3.3 to explain this performance difference, what I noticed immediately is that in the gcc-4.4 generated asm there are more "lea" instructions (+30%), but I doubt this is the reason of these poor results. Anyway, I haven't yet looked much in details. Cheers, Giuseppe
