Pentium 4 Optimization Complimenting icc 5.0

[Joe Buck]

On Wed, Feb 06, 2002 at 12:35:41PM -0800, Joe Buck wrote:
> > Intel has been attacked for this, by the way: the P4 often is slower than
> > the P3 for code tuned for the P3.

Richard Henderson writes:
> Not just "tuned for p3" -- the P4 is about 20% slower across the
> board when similar clock speeds are compared.  The P4 architecture
> team inside Intel has taken quite a lot of heat for this.

... unless you can get all the pipelines set up just right with DSP-like
code with completely predictable control flow, in which case the P4 flies.