On Thursday 26 August 2004 11:40 am, Alexander Dalloz wrote:
[snip]
This is an alway returning question, asked time by time. The RPMs of
Fedora Core are build for arch i386 with optimization enabled for P4
CPU. So they are able to run on all i386 platform and will use special
instructions on newer CPUs.
Yes, this comes up all the time. Unless they changed tp P4 optimization in FC3, though,
the build flags are what they've aleays been:
--march=i386 -mcpu=i686
That is, 386-compatible, but instruction organization optimized for a Pentium Pro/II/II.
How much improvement you'd see by building with "-march=pentium4" is left as
an exercise for the reader.
Also, I wonder about the quality of the P4 GCC optimizations in general. Back when the
current version was 3.2.x I read on the GCC mailing list that the P4 optimization probably
wouldn't be fully realized until v3.4. As the default compile for FC2 is v3.3.3, I
wonder if the P4-specific handling is completely baked.