[SCEV] Make SCEV or modeling more aggressive.

Use haveNoCommonBitsSet to figure out whether an "or" instruction
is equivalent to addition. This handles more cases than just
checking for a constant on the RHS.

Differential Revision: https://reviews.llvm.org/D32239



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300746 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed