[X86][InstCombine] Teach SimplifyDemandedVectorElts to handle scalar round intrinsics more correctly.
Now we only pass bit 0 of the DemandedElts to optimize operand 1 as we recurse since the upper bits are unused. Similarly we clear bit 0 for optimizing operand 0.
Also calculate UndefElts correctly.
Simplify InstCombineCalls for these instrinics to just call SimplifyDemandedVectorElts for the call instrution to reuse this support.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289629 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed