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    SubjectRe: [PATCH] [2.5] asm-generic/atomic.h and changes to arm, parisc, mips, m68k, sh, cris to use it
    Hi,

    On 9 Aug 2002, Luca Barbieri wrote:

    > > The compiler can cache the value in a register
    > It shouldn't since it is volatile and the machine has instructions with
    > memory operands.

    volatile is no guarantee for that:

    volatile int x;

    void f(int y)
    {
    x += y;
    }

    becomes:

    move.l x,%d0
    add.l 8(%a6),%d0
    move.l %d0,x

    I agree that volatile should avoid caching, but it does not guarantee an
    atomic modify.

    bye, Roman

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