[llvm] [LegalizeVectorOps] Use getBoolConstant instead of getAllOnesConstant in VectorLegalizer::UnrollVSETCC. (PR #121526)

[Simon Pilgrim via llvm-commits]

https://github.com/RKSimon approved this pull request.

LGTM with a suitable comment that we should be avoiding the select and performing a setcc+boolext instead

https://github.com/llvm/llvm-project/pull/121526