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    SubjectRe: likely/unlikely

    > 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.

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      Last update: 2005-03-22 13:23    [W:0.023 / U:6.776 seconds]
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