[llvm] [ScalarEvolutionExpander] Use IRBuilder::CreateBinOp in SCEVExpander::InsertBinop. (PR #146443)

[Nikita Popov via llvm-commits]

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@@ -19,8 +19,7 @@ define i8 @drop_nuw() {
 ; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[IV_NEXT]], 0
 ; CHECK-NEXT:    br i1 [[CMP]], label [[EXIT:%.*]], label [[LOOP]]
 ; CHECK:       exit:
-; CHECK-NEXT:    [[TMP0:%.*]] = add i8 [[IV_NEXT]], -1
-; CHECK-NEXT:    ret i8 [[TMP0]]
+; CHECK-NEXT:    ret i8 [[IV]]
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nikic wrote:

Without looking into it too deeply, changes like this might be problematic for LSR? Now the live-out is going to be the pre-inc IV rather than the post-inc one. (LSR should probably be wrapping things into Unknown in cases where it cares.)

https://github.com/llvm/llvm-project/pull/146443