On Thu, 24 Feb 2005 17:09:46 +0100, Biagio Lucini <[EMAIL PROTECTED]> wrote: > On Thursday 24 February 2005 16.52, Paolo Bonzini wrote: > > > > Try these five combinations: > > > [...] > > > > -O3 -fomit-frame-pointer -ffast-math -fno-tree-pre > > [...] > > This + 387 math is the one with the larger impact: it rises MC to around 80, > but composite is still 279 (vs. ~ 345 for GCC 3.4). I will test on amd64, > just to see whether there is any difference.
I think the Intel compiler with -iop will inline Random_nextDouble which should explain the difference you see. The best options for gcc I found were compiling and linking via gcc-4.0 -O3 -funroll-loops -D__NO_MATH_INLINES -ffast-math -march=pentium4 -mfpmath=sse -ftree-vectorize -onestep -o scimark2 scimark2.c FFT.c kernel.c Stopwatch.c Random.c SOR.c SparseCompRow.c array.c MonteCarlo.c LU.c -lm -fomit-frame-pointer -finline-functions Note that gcc with -onestep still cannot inline over unit-boundaries. Richard.
