[LegalizeVectorTypes] Have SplitVecOp_TruncateHelper fall back to SplitVecOp_UnaryOp if splitting the output type would be a legal type.
SplitVecOp_TruncateHelper tries to introduce a multilevel truncate to avoid scalarization. But if splitting the result type would still be a legal type we don't need to do that.
The comment block at the top of the function implied that this was already implemented. I looked back through the history and it doesn't look to have ever been checked.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@347479 91177308-0d34-0410-b5e6-96231b3b80d8
5 files changed