[PATCH] D13364: [x86] PR24562: fix incorrect folding of X86ISD::PSHUFB nodes that have a mask of all indices with the most significant bit set.

[Simon Pilgrim via llvm-commits]

RKSimon added a comment.

What about asserting that the Index is Zero/Undef or a valid index? This might be going too far but the 'undef == (index < 0)' pattern is something that is very common in the shuffle code and I think we should be doing more to sanitize these values,


http://reviews.llvm.org/D13364