[InstCombine] (A + 1) + (B ^ -1) --> A - B

Turn canonicalized subtraction back into (-1 - B) and combine it with (A + 1) into (A - B).
This is similar to the folding already done for (B ^ -1) + Const into (-1 + Const) - B.

Differential Revision: https://reviews.llvm.org/D48535


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@335579 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed