[InstCombine] reduce raw IR narrowing rotate patterns to funnel shift
  
Similar to rL350199 - there are no known analysis/codegen holes for
funnel shift intrinsics now, so we can canonicalize the 6+ regular
instructions to funnel shift to improve vectorization, inlining,
unrolling, etc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@350419 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed