mov reg,0 vs xor reg,reg in core.atomic ?

[darat via Digitalmars-d-learn]

Is there a particular reason explaining why mov reg,0 is used and 
not xor reg,reg ?
(or even and reg, 0)

for example here:
https://github.com/D-Programming-Language/druntime/blob/master/src/core/atomic.d#L1009

It seems that in Go too mov is used:
https://github.com/golang/go/blob/0104a31b8fbcbe52728a08867b26415d282c35d2/src/runtime/internal/atomic/asm_amd64p32.s#L15