diff options
Diffstat (limited to 'llvm/lib/Transforms/Scalar/Reassociate.cpp')
| -rw-r--r-- | llvm/lib/Transforms/Scalar/Reassociate.cpp | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/llvm/lib/Transforms/Scalar/Reassociate.cpp b/llvm/lib/Transforms/Scalar/Reassociate.cpp index ed7340f7e6d..66fa0744b84 100644 --- a/llvm/lib/Transforms/Scalar/Reassociate.cpp +++ b/llvm/lib/Transforms/Scalar/Reassociate.cpp @@ -629,8 +629,13 @@ static bool LinearizeExprTree(BinaryOperator *I, // Add any constants back into Ops, all globbed together and reduced to having // weight 1 for the convenience of users. Constant *Identity = ConstantExpr::getBinOpIdentity(Opcode, I->getType()); - if (Cst && Cst != Identity) + if (Cst && Cst != Identity) { + // If combining multiple constants resulted in the absorber then the entire + // expression must evaluate to the absorber. + if (Cst == Absorber) + Ops.clear(); Ops.push_back(std::make_pair(Cst, APInt(Bitwidth, 1))); + } // For nilpotent operations or addition there may be no operands, for example // because the expression was "X xor X" or consisted of 2^Bitwidth additions: |
