Does VC6 also produces code for 64-bit processor? If gcc is slow for you stick with the faster environment. -ishwar On Wed, 20 Apr 2005, Snoopy Cyber wrote: > I've written a small numeric program(600 lines) with c under linux. I > compiled it under 64bit linux using 64bit gcc-3.4(without linking > other external library), the program runs very slow. > Then I managed to compile it under windows using VC on a machine which > is exactly the same with mine(amd64 2800, 1g ram). The program runs > very fast, the speed is nearly 1000 times faster. I don't know how to > solve the problem, as my main develop environment is linux. > I used gcc as follows: > gcc-3.4 -g0 -march=k8 -O3 -fomit-frame-pointer -funit-at-a-time > -fpeel-loops -ftracer -funswitch-loops -mfpmath=sse > (do not use -ffast-math, as it will cause output error) > with vc6.0 I just use the default options. > > I use clock()/1.e6 to determine the time elapsed in second > under linux, output : 1.39 s > under windows, output: 2.5e-3 s >
