Doesn't -msse have to be enabled as well for -mfpmath=see to work? But in my tests, sse math doesn't improve performance much (if all)...dosbox is not that fpu intensive.

you don't have to have -msse if you use -march with an appropriate cpu w/sse since it will be automatically turned on.

as for -mfpmath, i've seen improvements with other stuff so it's become a standard flag with anything i compile.

hey thnx for the heads up on dosbox & the sse math, it's been too long since i've tried using other cflag options. since i had some free time this evening i decided to rebench with some different cflag options and the one that produced the fastest code was:

configure CFLAGS="-g -O3 -pipe -fomit-frame-pointer -funroll-loops -ffast-math" CXXFLAGS="-g -O3 -pipe -fomit-frame-pointer -funroll-loops -ffast-math"

i used the .65 source, and this gave about a ~10% performance increase over the official release as i dropped the .exe from the official release into my testfolder for comparison.
of course my benching is unscientific, and should be taken with a grain of salt, a lime, and a shot of tequila.

which version of gcc did you use ?
-pipe doesn't influence speed.

You didn't specify an arch or a cpu
try: -march=i586 -mtune=i686 as aditional flags
It's a bit odd that you get 10 % increase from your own judgement as the flags are quite similar to ones I used (I have only 1 flag different except for the arch/tune flag)

Be sure to configure dosbox like this

1./configure --enable-core-inline

for dosbox i use gcc-3.4.2 as mentioned in an earlier post as it produces the fastest version of dosbox for me (i've benched dosbox with gcc-3.4.2, 3.4.5, 4.0.2, 4.0.3, and 4.1.0).

i used -march=athlon-xp as one of my flags when i rebenched that time around but when i used march=athlon-xp the speed was about the same speed as the official binary. i'll try compile and bench another with the march/mtune you mentioned instead of athlon-xp and will see what that does.

using "--enable-core-inline" put my builds using gcc-3.4.2 and gcc-4.1.0 and yours all within close to the same speed. i guess forgetting to add that is what gave mine the ~10% speed increase. i guess i can now ditch gcc-3.4.2 and stick with only using 4.1.0 since i only kept 3.4.2 just for dosbox, thanx for the info.

hmm well that is interresting. maybe your cpu has a small cache and the larger cpu core because of the inline memory funcitons made it slower.

We might need to benchmark that again.

i don't think it's my cache:

i've deleted the builds already, but if you are interested i could rebuild them and send them to you.