are you sure about that? 
<a href="http:&#x2F;&#x2F;docs.huihoo.com&#x2F;help-pc&#x2F;asm-repne.html" rel="nofollow">http:&#x2F;&#x2F;docs.huihoo.com&#x2F;help-pc&#x2F;asm-repne.html</a>
<a href="http:&#x2F;&#x2F;faydoc.tripod.com&#x2F;cpu&#x2F;repnz.htm" rel="nofollow">http:&#x2F;&#x2F;faydoc.tripod.com&#x2F;cpu&#x2F;repnz.htm</a><p>repnz movsb is undocumented and undefined, MOVS doesnt modify flags, not sure how would that work