On Fri, Oct 31, 2008 at 01:01:30AM -0400, Kumba wrote: > +#ifndef (_MIPS_ARCH_R10000) > +#define R10K_BEQZ_INSN "beqz %1,1b\n" > +#else > +#define R10K_BEQZ_INSN "beqzl %1,1b\n" > +#endif In the kernel we have very good knowledge about what types of processors are being used for what configuration; much less in userland and the code as suggested by you would result in a silent failure on affected R10000 machines if version built not for the R10000 was being used - iow no improvment over what we have right now. So for userland I'd prefer to o MIPS I builds: use the some 28 nops. o Builds for MIPS II or better: always use the branch likely o A runtime test would have to be implemented pessimisticall because it would have to rely on /proc being mounted which isn't available early in the boot process. It's probably going to add more overhead than it saves anyway. There is a price for using branch likely - but not that high. In the grand picture it'll almost certainly vanish in the benchmarking noise. Ralf
