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    SubjectRe: BUG: GCC-4.4.x changes the function frame on some functions
    On Fri, 20 Nov 2009, Thomas Gleixner wrote:

    > On Thu, 19 Nov 2009, Linus Torvalds wrote:
    > > On Fri, 20 Nov 2009, Thomas Gleixner wrote:
    > > >
    > > > While testing various kernel configs we found out that the problem
    > > > comes and goes. Finally I started to compare the gcc command line
    > > > options and after some fiddling it turned out that the following
    > > > minimal deltas change the code generator behaviour:
    > > >
    > > > Bad: -march=pentium-mmx -Wa,-mtune=generic32
    > > > Good: -march=i686 -mtune=generic -Wa,-mtune=generic32
    > > > Good: -march=pentium-mmx -mtune-generic -Wa,-mtune=generic32

    Found some more:

    Bad: -march=k6 -Wa,-mtune=generic32
    Bad: -march=geode -Wa,-mtune=generic32
    Bad: -march=c3 -Wa,-mtune=generic32

    That seems every thing which has MMX support but no SSE and is somehow
    compatible to the pentium-mmx.

    Looks like the code generator optimization for those was done after
    consuming the secret gcc-shrooms.

    Thanks,

    tglx


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