[PATCH] D36781: [InstCombine] Make folding (X >s -1) ? C1 : C2 --> ((X >>s 31) & (C2 - C1)) + C1 support splat vectors

[Craig Topper via Phabricator via llvm-commits]

craig.topper created this revision.

This reuses decomposeBitTestICmp to decode the compare.

I'm assuming that pointer icmps will never match decomposeBitTestICmp because we shouldn't be doing relational comparisons on points, I think? So I removed the IntegerType check, but I could be wrong.

I've deferred the equality check on the type of compare vs the select until after the decomposeBitTestICmp call because I've considering putting an m_Trunc test inside of decomposeBitTestICmp so X won't always just be the CmpLHS.


https://reviews.llvm.org/D36781

Files:
  lib/Transforms/InstCombine/InstCombineSelect.cpp
  test/Transforms/InstCombine/select.ll

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