Even though the implementation in emitAtomicCmpSwapW() was correct, it made Valgrind report an error.
Instead of using a RISBG on CmpVal, an LL[CH]R can be made on the OldVal, and the problem is avoided.
CmpVal: Should not need a LL[HC]R, as it should already be zero-extended also in the case of a non-constant, or?
Test updating only begun...
This is not needed any more -- it is already done by common code now that you set getAtomicExtendOps to ZERO_EXTEND.