Original sentence: One example is the CMPXCHG16B instruction, an extension of the CMPXCHG8B instruction present on most x86 processors; this extension relates to lock-free algorithms in multi-threaded codes in conjunction with 128 bit compare & swap; which is rarely used in today; early AMD64 processors do not have this instruction, while all EM64T processors do
Edited sentence: One example is the CMPXCHG16B instruction, an extension of the CMPXCHG8B instruction present on most x86 processors; early AMD64 processors do not have this instruction, while all EM64T processors do