d74d841b65
Try to push the constant operand into a ZExt: A + zext (-A + B) -> zext (B), if trunc (A) + -A + B does not unsigned-wrap. The actual code supports ZExts with arbitrary number of arguments, hence the getAddExpr in the return. This helps SCEV reasoning in some cases, commonly when adding an offset to a zero-extended SCEV that subtracts the same offset. Note that this is restricted to cases where we can fold away an operand of the inner Add. This is needed to avoid bad interactions with patterns when forming ZExts, which try to push to ZExt to add operands. https://alive2.llvm.org/ce/z/q7d303 PR: https://github.com/llvm/llvm-project/pull/151227