[SelectionDAG] add helper query for binops; NFC

We will also use this in a planned enhancement for vector insertelement.

llvm-svn: 340741

llvm/include/llvm/CodeGen/SelectionDAGNodes.h

@@ -2444,6 +2444,18 @@ namespace ISD {
       cast<StoreSDNode>(N)->getAddressingMode() == ISD::UNINDEXED;
   }
 
+  /// Return true if the node is a math/logic binary operator. This corresponds
+  /// to the IR function of the same name.
+  inline bool isBinaryOp(const SDNode *N) {
+    auto Op = N->getOpcode();
+    return (Op == ISD::ADD || Op == ISD::SUB || Op == ISD::MUL ||
+            Op == ISD::AND || Op == ISD::OR || Op == ISD::XOR ||
+            Op == ISD::SHL || Op == ISD::SRL || Op == ISD::SRA ||
+            Op == ISD::SDIV || Op == ISD::UDIV || Op == ISD::SREM ||
+            Op == ISD::UREM || Op == ISD::FADD || Op == ISD::FSUB ||
+            Op == ISD::FMUL || Op == ISD::FDIV || Op == ISD::FREM);
+  }
+
   /// Attempt to match a unary predicate against a scalar/splat constant or
   /// every element of a constant BUILD_VECTOR.
   bool matchUnaryPredicate(SDValue Op,

llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

@@ -1874,17 +1874,7 @@ static ConstantSDNode *getAsNonOpaqueConstant(SDValue N) {
 }
 
 SDValue DAGCombiner::foldBinOpIntoSelect(SDNode *BO) {
-  auto BinOpcode = BO->getOpcode();
-  assert((BinOpcode == ISD::ADD || BinOpcode == ISD::SUB ||
-          BinOpcode == ISD::MUL || BinOpcode == ISD::SDIV ||
-          BinOpcode == ISD::UDIV || BinOpcode == ISD::SREM ||
-          BinOpcode == ISD::UREM || BinOpcode == ISD::AND ||
-          BinOpcode == ISD::OR || BinOpcode == ISD::XOR ||
-          BinOpcode == ISD::SHL || BinOpcode == ISD::SRL ||
-          BinOpcode == ISD::SRA || BinOpcode == ISD::FADD ||
-          BinOpcode == ISD::FSUB || BinOpcode == ISD::FMUL ||
-          BinOpcode == ISD::FDIV || BinOpcode == ISD::FREM) &&
-         "Unexpected binary operator");
+  assert(ISD::isBinaryOp(BO) && "Unexpected binary operator");
 
   // Don't do this unless the old select is going away. We want to eliminate the
   // binary operator, not replace a binop with a select.
@@ -1914,6 +1904,7 @@ SDValue DAGCombiner::foldBinOpIntoSelect(SDNode *BO) {
   // propagate non constant operands into select. I.e.:
   // and (select Cond, 0, -1), X --> select Cond, 0, X
   // or X, (select Cond, -1, 0) --> select Cond, -1, X
+  auto BinOpcode = BO->getOpcode();
   bool CanFoldNonConst = (BinOpcode == ISD::AND || BinOpcode == ISD::OR) &&
                          (isNullConstantOrNullSplatConstant(CT) ||
                           isAllOnesConstantOrAllOnesSplatConstant(CT)) &&