[Bug target/53291] Code generated for xtest is wrong

[andi-gcc at firstfloor dot org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53291

--- Comment #3 from Andi Kleen <andi-gcc at firstfloor dot org> 2012-05-09 17:17:56 UTC ---
Correction. We can keep the xor %reg,%reg. We just need it because setnz only
sets 8 bit to initialize the higher order bits. 

Alternatively the value can be zero extended afterwards or just stay at 8 bit
if there is no need for it.