diff options
| -rw-r--r-- | llvm/lib/Transforms/Scalar/NaryReassociate.cpp | 12 | ||||
| -rw-r--r-- | llvm/test/Transforms/NaryReassociate/nary-add.ll | 11 |
2 files changed, 19 insertions, 4 deletions
diff --git a/llvm/lib/Transforms/Scalar/NaryReassociate.cpp b/llvm/lib/Transforms/Scalar/NaryReassociate.cpp index 7d3080dcd9b..af61068c97b 100644 --- a/llvm/lib/Transforms/Scalar/NaryReassociate.cpp +++ b/llvm/lib/Transforms/Scalar/NaryReassociate.cpp @@ -217,10 +217,14 @@ Instruction *NaryReassociate::tryReassociateAdd(Value *LHS, Value *RHS, // = (A + RHS) + B or (B + RHS) + A const SCEV *AExpr = SE->getSCEV(A), *BExpr = SE->getSCEV(B); const SCEV *RHSExpr = SE->getSCEV(RHS); - if (auto *NewI = tryReassociatedAdd(SE->getAddExpr(AExpr, RHSExpr), B, I)) - return NewI; - if (auto *NewI = tryReassociatedAdd(SE->getAddExpr(BExpr, RHSExpr), A, I)) - return NewI; + if (BExpr != RHSExpr) { + if (auto *NewI = tryReassociatedAdd(SE->getAddExpr(AExpr, RHSExpr), B, I)) + return NewI; + } + if (AExpr != RHSExpr) { + if (auto *NewI = tryReassociatedAdd(SE->getAddExpr(BExpr, RHSExpr), A, I)) + return NewI; + } } return nullptr; } diff --git a/llvm/test/Transforms/NaryReassociate/nary-add.ll b/llvm/test/Transforms/NaryReassociate/nary-add.ll index 39d7c59ef9d..b3093ff6ecd 100644 --- a/llvm/test/Transforms/NaryReassociate/nary-add.ll +++ b/llvm/test/Transforms/NaryReassociate/nary-add.ll @@ -196,3 +196,14 @@ define void @iterative(i32 %a, i32 %b, i32 %c) { ret void } + +define void @avoid_infinite_loop(i32 %a, i32 %b) { +; CHECK-LABEL: @avoid_infinite_loop + %ab = add i32 %a, %b +; CHECK-NEXT: %ab + %ab2 = add i32 %ab, %b +; CHECK-NEXT: %ab2 + call void @foo(i32 %ab2) +; CHECK-NEXT: @foo(i32 %ab2) + ret void +} |
