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if /bin/sh ${ATOMICDIR}/chkdup.sh arch_${atomic}_dec_if_positive dec_if_positive
then
cat <<EOF
/**
* arch_${atomic}_dec_if_positive - Atomic decrement if old value is positive
* @v: pointer of type ${atomic}_t
*
* Atomically decrement @v with full ordering, but only if the original
* value is greater than zero, returning new value. Note that the desired
* new value will be returned even if the decrement did not occur, so that
* if the old value is -3, then there @v will not be decremented, but -4
* will be returned. As a result, if the return value is non-negative,
* then the value was in fact decremented.
*/
EOF
fi
cat <<EOF
static __always_inline ${ret}
arch_${atomic}_dec_if_positive(${atomic}_t *v)
{
${int} dec, c = arch_${atomic}_read(v);
do {
dec = c - 1;
if (unlikely(dec < 0))
break;
} while (!arch_${atomic}_try_cmpxchg(v, &c, dec));
return dec;
}
EOF
|
