Dice R. Random wrote: > > It is not necessary to tell gcc to use special instruction sets for > your processor. When you specify -march gcc automatically knows > exactly what instructions your processor is capable of utilizing most > effectively. I'm not sure about this. Tonight I'll make a test: I'll compile a package with and without these flags and watch the output and the outcome.
> > I am not familiar with PIC, but if portage gives a big red warning > about explicitly enabling it in your CFLAGS I'm sure that there have > been problems with it. If a package requires the flag then it should > enable it in its own local CFLAGS. > Already answered about Position Independent Code and why I use it. Shortly: http://www.gentoo.org/doc/en/prelink-howto.xml > A 3dnow instruction path isn't always the best optimization for every > user and every package. Also, AMD's Athlon and Opteron processors are > not the only ones supported under the amd64 arch, there are also > Intel's x86-64 processors to consider. While I imagine that Intel > processors can execute 3dnow instructions I also imagine that SSE > would be faster. I'm really not sure here. I cant tell which is better -3dnow(ext) or sse{1..3}, but isn't it best if one enables all kinds of optimizations supported by the CPU? -- [email protected] mailing list
