[InstCombine] Fold  x & (-1 >> y) != x  to  x u> (-1 >> y)

Summary:
A complementary fold to D49179.

https://bugs.llvm.org/show_bug.cgi?id=38123
https://rise4fun.com/Alive/Rny

Caveat: one more thing in `test/Transforms/InstCombine/icmp-logical.ll` breaks.

Reviewers: spatel, craig.topper

Reviewed By: spatel

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D49205

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@336911 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed