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    SubjectRe: [PATCH] [POWERPC] Improve (in|out)_beXX() asm code
    Date
    Trent Piepho <tpiepho@freescale.com> writes:

    > For the LE versions, eventually they boil down to an asm that will look
    > something like this:
    > asm("sync; stwbrx %1,0,%2" : "=m" (*addr) : "r" (val), "r" (addr));
    >
    > While not perfect, this appears to be the best one can do. The issue is
    > that the "stwbrx" instruction only comes in an indexed, or 'x', version, in
    > which the address is represented by the sum of two registers (the "0,%2").
    > Unfortunately, gcc doesn't have a constraint for an indexed memory
    > reference.

    There is the "Z" constraint, which matches either an indirect or an
    indexed memory address. That should fit here.

    Andreas.

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    Andreas Schwab, SuSE Labs, schwab@suse.de
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