cvs commit: src/sys/i386/i386 pmap.c

[Dag-ErlingSmørgrav]

Peter Wemm <peter at wemm.org> writes:
> Massively deep pipelines help get the MHz up, and careful optimization can
> stop it affecting frame rates.  But it blows chunks if you mispredict a
> branch in typical gcc generated code.  Or take our libc syscall stubs..
> every single one will be mispredicted because the usual case (no errors)
> has an opposite direction branch to what intel's static branch prediction
> expects.

Is there any way to teach (or trick) gcc to generate a branch which
the p4 will predict correctly?

DES
-- 
Dag-Erling Smørgrav - des at des.no