[PATCH] D30123: [InstCombine] shrink truncated shuffle with constant operand

[Eli Friedman via Phabricator via llvm-commits]

efriedma added a comment.

"the mask doesn't change"

That's technically true... but doesn't really match the spirit of the rule that we don't change shuffle masks.  Many targets have shuffles that only work at specific widths.


https://reviews.llvm.org/D30123