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    SubjectRe: [PATCH 03/13] jump label v9: x86 support
    On Thu, Jun 10, 2010 at 02:14:40PM +0200, Ingo Molnar wrote:
    > * Peter Zijlstra <> wrote:
    > > On Wed, 2010-06-09 at 17:39 -0400, Jason Baron wrote:
    > >
    > > That deserves a comment somewhere, it basically makes OPTIMIZE_FOR_SIZE
    > > useless...
    > Hm, we need more than a comment for that - distros enable CC_OPTIMIZE_FOR_SIZE
    > all the time, for the massive kernel image (and hotpath cache footprint)
    > savings. Is this fixable?
    > Thanks,
    > Ingo

    When I tested 'jump label' with CC_OPTIMIZE_FOR_SIZE, I saw a small
    performance drop , b/c there is less block re-ordering happening. There
    was a small gcc patch that Richard Henderson wrote to allow block
    re-ordering while still taking size into account. However, it did
    increase the text size somewhat from what current optimize for size
    does. This small patch combined with jump labels resulted in the
    expected performance gains. However, to keep the size to what it is now
    a much more involved gcc patch would be required.

    Thus, until this additional gcc optimization is done, I've posted this
    as depends on !CC_OPTIMIZE_FOR_SIZE. If this gcc work is done, we can
    lift this restriction. As mentioned, a number of large distros are
    compiled !CC_OPTIMIZE_FOR_SIZE (rhel, sles), so we should still get a lot of
    benefit from this. Also, if people find these patches useful we might
    create some more impetus for the gcc work. So i see this as an iterative



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