Index: include/llvm/CodeGen/SelectionDAGNodes.h
===================================================================
--- include/llvm/CodeGen/SelectionDAGNodes.h
+++ include/llvm/CodeGen/SelectionDAGNodes.h
@@ -1401,16 +1401,24 @@
 
 /// Returns true if \p V is a constant integer zero.
 bool isNullConstant(SDValue V);
+
 /// Returns true if \p V is an FP constant with a value of positive zero.
 bool isNullFPConstant(SDValue V);
+
 /// Returns true if \p V is an integer constant with all bits set.
 bool isAllOnesConstant(SDValue V);
+
 /// Returns true if \p V is a constant integer one.
 bool isOneConstant(SDValue V);
+
 /// Returns true if \p V is a bitwise not operation. Assumes that an all ones
 /// constant is canonicalized to be operand 1.
 bool isBitwiseNot(SDValue V);
 
+/// Returns the SDNode if it is a constant splat BuildVector or constant int.
+ConstantSDNode *isConstOrConstSplat(SDValue N);
+
+
 class GlobalAddressSDNode : public SDNode {
   const GlobalValue *TheGlobal;
   int64_t Offset;
Index: lib/CodeGen/SelectionDAG/DAGCombiner.cpp
===================================================================
--- lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -787,27 +787,6 @@
 }
 
 // \brief Returns the SDNode if it is a constant splat BuildVector or constant
-// int.
-static ConstantSDNode *isConstOrConstSplat(SDValue N) {
-  if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N))
-    return CN;
-
-  if (BuildVectorSDNode *BV = dyn_cast<BuildVectorSDNode>(N)) {
-    BitVector UndefElements;
-    ConstantSDNode *CN = BV->getConstantSplatNode(&UndefElements);
-
-    // BuildVectors can truncate their operands. Ignore that case here.
-    // FIXME: We blindly ignore splats which include undef which is overly
-    // pessimistic.
-    if (CN && UndefElements.none() &&
-        CN->getValueType(0) == N.getValueType().getScalarType())
-      return CN;
-  }
-
-  return nullptr;
-}
-
-// \brief Returns the SDNode if it is a constant splat BuildVector or constant
 // float.
 static ConstantFPSDNode *isConstOrConstSplatFP(SDValue N) {
   if (ConstantFPSDNode *CN = dyn_cast<ConstantFPSDNode>(N))
Index: lib/CodeGen/SelectionDAG/SelectionDAG.cpp
===================================================================
--- lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -2697,7 +2697,7 @@
     if (Tmp2 == 1) return 1;
 
     // Handle NEG.
-    if (ConstantSDNode *CLHS = dyn_cast<ConstantSDNode>(Op.getOperand(0)))
+    if (ConstantSDNode *CLHS = isConstOrConstSplat(Op.getOperand(0)))
       if (CLHS->isNullValue()) {
         APInt KnownZero, KnownOne;
         computeKnownBits(Op.getOperand(1), KnownZero, KnownOne, Depth+1);
@@ -6653,6 +6653,25 @@
   return V.getOpcode() == ISD::XOR && isAllOnesConstant(V.getOperand(1));
 }
 
+ConstantSDNode *llvm::isConstOrConstSplat(SDValue N) {
+  if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N))
+    return CN;
+
+  if (BuildVectorSDNode *BV = dyn_cast<BuildVectorSDNode>(N)) {
+    BitVector UndefElements;
+    ConstantSDNode *CN = BV->getConstantSplatNode(&UndefElements);
+
+    // BuildVectors can truncate their operands. Ignore that case here.
+    // FIXME: We blindly ignore splats which include undef which is overly
+    // pessimistic.
+    if (CN && UndefElements.none() &&
+        CN->getValueType(0) == N.getValueType().getScalarType())
+      return CN;
+  }
+
+  return nullptr;
+}
+
 HandleSDNode::~HandleSDNode() {
   DropOperands();
 }
Index: test/CodeGen/X86/sar_fold64.ll
===================================================================
--- test/CodeGen/X86/sar_fold64.ll
+++ test/CodeGen/X86/sar_fold64.ll
@@ -80,16 +80,6 @@
 ; CHECK-NEXT:    pxor %xmm1, %xmm1
 ; CHECK-NEXT:    psubd %xmm0, %xmm1
 ; CHECK-NEXT:    movdqa %xmm1, %xmm0
-; CHECK-NEXT:    psrad $31, %xmm0
-; CHECK-NEXT:    movdqa %xmm1, %xmm2
-; CHECK-NEXT:    movsd {{.*#+}} xmm2 = xmm0[0],xmm2[1]
-; CHECK-NEXT:    pshufd {{.*#+}} xmm2 = xmm2[1,3,2,3]
-; CHECK-NEXT:    movdqa %xmm1, %xmm0
-; CHECK-NEXT:    psrad $5, %xmm0
-; CHECK-NEXT:    psrad $1, %xmm1
-; CHECK-NEXT:    movsd {{.*#+}} xmm0 = xmm1[0],xmm0[1]
-; CHECK-NEXT:    pshufd {{.*#+}} xmm0 = xmm0[0,2,2,3]
-; CHECK-NEXT:    punpckldq {{.*#+}} xmm0 = xmm0[0],xmm2[0],xmm0[1],xmm2[1]
 ; CHECK-NEXT:    retq
 ;
   %and = and <4 x i32> %x, <i32 1, i32 1, i32 1 , i32 1>