diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 30a4c9f637cc..9770ae232bfe 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -1282,6 +1282,9 @@ SDOperand DAGCombiner::visitSHL(SDNode *N) { // fold (shl x, 0) -> x if (N1C && N1C->isNullValue()) return N0; + // fold (shl x, 1) -> (add x, x) + if (N1C && N1C->getValue() == 1) + return DAG.getNode(ISD::ADD, VT, N0, N0); // if (shl x, c) is known to be zero, return 0 if (N1C && MaskedValueIsZero(SDOperand(N, 0), ~0ULL >> (64-OpSizeInBits),TLI)) return DAG.getConstant(0, VT); diff --git a/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp b/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp index 1a926d076e90..437519c3f12c 100644 --- a/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp +++ b/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp @@ -363,26 +363,6 @@ SDOperand X86DAGToDAGISel::Select(SDOperand N) { switch (Node->getOpcode()) { default: break; - case ISD::SHL: - if (ConstantSDNode *CN = dyn_cast(Node->getOperand(1))) { - if (CN->getValue() == 1) { - // X = SHL Y, 1 -> X = ADD Y, Y - switch (NVT) { - default: assert(0 && "Cannot shift this type!"); - case MVT::i8: Opc = X86::ADD8rr; break; - case MVT::i16: Opc = X86::ADD16rr; break; - case MVT::i32: Opc = X86::ADD32rr; break; - } - SDOperand Tmp0 = Select(Node->getOperand(0)); - if (Node->hasOneUse()) - return CurDAG->SelectNodeTo(Node, Opc, NVT, Tmp0, Tmp0); - else - return CodeGenMap[N] = - CurDAG->getTargetNode(Opc, NVT, Tmp0, Tmp0); - } - } - break; - case ISD::TRUNCATE: { unsigned Reg; MVT::ValueType VT;