Currently the overview indicates that if the mask lane is not zero, not all-ones, and the top bit is 0 then the output must be the b element. This doesn't match (what I believe is) the intended implementation on AArch64 using the bsl instruction which is the same as v128.bitselect.
Currently the overview indicates that if the mask lane is not zero, not all-ones, and the top bit is 0 then the output must be the
belement. This doesn't match (what I believe is) the intended implementation on AArch64 using thebslinstruction which is the same asv128.bitselect.