On Tue, Nov 30, 2004 at 12:05:51PM -0500, William M. Quarles wrote: > this case irrelevant instruction set), I'd really like to see that > performance difference. Now were you saying that this cmov is part of > i486 or i686? I'd like to try rebuilding everything to see if it makes > a difference. cmov is an optional instruction for i686 - it turns up on the PPro, PII, PIII, PIV and Pentium M at least. By PIV its as slow or slower than not using it. > Is the advantage still there, or is it just no longer a significant > advantage? Or is it a cost? Unless it's a cost, I don't see what's > wrong with putting in the advantage, unless it's a lot more work on your > part. Is it more work? Its a cost because some processors we support today lack this instruction but are otherwise 686. Alan
