diff options
| -rw-r--r-- | llvm/lib/Transforms/Scalar/NaryReassociate.cpp | 3 | ||||
| -rw-r--r-- | llvm/test/Transforms/NaryReassociate/pr35710.ll | 19 |
2 files changed, 22 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/Scalar/NaryReassociate.cpp b/llvm/lib/Transforms/Scalar/NaryReassociate.cpp index b026c8d692c..243d7fefb67 100644 --- a/llvm/lib/Transforms/Scalar/NaryReassociate.cpp +++ b/llvm/lib/Transforms/Scalar/NaryReassociate.cpp @@ -429,6 +429,9 @@ NaryReassociatePass::tryReassociateGEPAtIndex(GetElementPtrInst *GEP, Instruction *NaryReassociatePass::tryReassociateBinaryOp(BinaryOperator *I) { Value *LHS = I->getOperand(0), *RHS = I->getOperand(1); + // There is no need to reassociate 0. + if (SE->getSCEV(I)->isZero()) + return nullptr; if (auto *NewI = tryReassociateBinaryOp(LHS, RHS, I)) return NewI; if (auto *NewI = tryReassociateBinaryOp(RHS, LHS, I)) diff --git a/llvm/test/Transforms/NaryReassociate/pr35710.ll b/llvm/test/Transforms/NaryReassociate/pr35710.ll new file mode 100644 index 00000000000..f46dd27607e --- /dev/null +++ b/llvm/test/Transforms/NaryReassociate/pr35710.ll @@ -0,0 +1,19 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py +; RUN: opt < %s -nary-reassociate -S | FileCheck %s + +; The test check that compilation does not fall into infinite loop. + +define i8 @foo(i8 %v) local_unnamed_addr #0 { +; CHECK-LABEL: @foo( +; CHECK-NEXT: region.0: +; CHECK-NEXT: [[TMP0:%.*]] = mul nsw i8 16, [[V:%.*]] +; CHECK-NEXT: [[TMP1:%.*]] = mul nsw i8 0, [[TMP0]] +; CHECK-NEXT: [[TMP2:%.*]] = mul nsw i8 1, [[TMP1]] +; CHECK-NEXT: ret i8 [[TMP2]] +; +region.0: + %0 = mul nsw i8 16, %v + %1 = mul nsw i8 0, %0 + %2 = mul nsw i8 1, %1 + ret i8 %2 +} |
