On Fri, Nov 05, 1999 at 11:08:34AM -0500, Ben Collins wrote: > On Fri, Nov 05, 1999 at 09:57:07AM -0600, Brian Boonstra wrote: > > Ingo wrote: > > > On Thu, Nov 04, 1999 at 05:08:04PM +0100, Robert Varga wrote: > > > > > > > > How can I recompile the packages so that they be optimized for running > > > > on > > > > Pentium or Pentium-II or else? > > > > Does that mean that gcc normally is NOT Pentium optimized? > > No. GCC can optimize for pentiums, by default it compiles for i386 though. > This is needed so that we don't produce code which wont run on some > systems that we want to support. All that is need is the proper CFLAGS set > (which I assume the scripts that replace the normal gcc and g++ merely add > these manually, and without the need for modifying the build).
Don't expect too much of these pentium-specific options. The biggest speedup I have seen for a fractal generator on a PentiumII, was the one I got with -Os. This is not pentium-specific at all. It reduces the code size, so that it fits better in the processor cache. It was only 12% faster than the regular -O2 optimization, which everybody uses. Adding -ffast-math made the program slower (sic), and -march=pentiumpro did not do anything noticable at all. I personally don't think you will note a big difference if you recompile all of debian with pentium-specific optimization options. This may change once the intel optimizations are built into gcc though. HTH, Eric -- E.L. Meijer ([EMAIL PROTECTED]) Eindhoven Univ. of Technology Lab. for Catalysis and Inorg. Chem. (SKA)
