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    SubjectRe: [PATCH] Make shr to divide by power of 2
    On 08/07/2009 12:50 AM, Andi Kleen wrote:
    > Sergey Senozhatsky<sergey.senozhatsky@gmail.com> writes:
    >> Of course, compiler supposed to do something like
    >> add $0x7,%eax
    >> shr $0x3,%eax
    >> instead of div. Should we rely on this?
    >
    > Yes. We should rely on this.

    It may depend on the selected CPU type that gcc is optimizing for - I
    believe that on some P4s the shift may actually be slower than the divide..


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