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> likely/unlikely set the branch prediction values to 99% or 1% > respectively. If this causes the code generated to perform less > optimally than without, I'm sure the gcc guys would be -very- interested > to hear that... On some ppc64 the branch prediction is quite good and static prediction will override the dynamic prediction. I think we avoid predicting a branch unless we are quite sure (95%/5%). So if likely/unlikely is overused (on more marginal conditionals) then it could be a performance loss. Anton - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ | |||||||||
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