diff --git a/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp b/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp
index 3a4b3de..665b21f 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp
+++ b/lib/CodeGen/SelectionDAG/LegalizeFloatTypes.cpp
@@ -817,6 +817,7 @@
   case ISD::FABS:       ExpandFloatRes_FABS(N, Lo, Hi); break;
   case ISD::FADD:       ExpandFloatRes_FADD(N, Lo, Hi); break;
   case ISD::FCEIL:      ExpandFloatRes_FCEIL(N, Lo, Hi); break;
+  case ISD::FCOPYSIGN:  ExpandFloatRes_FCOPYSIGN(N, Lo, Hi); break;
   case ISD::FCOS:       ExpandFloatRes_FCOS(N, Lo, Hi); break;
   case ISD::FDIV:       ExpandFloatRes_FDIV(N, Lo, Hi); break;
   case ISD::FEXP:       ExpandFloatRes_FEXP(N, Lo, Hi); break;
@@ -890,6 +891,17 @@
   GetPairElements(Call, Lo, Hi);
 }
 
+void DAGTypeLegalizer::ExpandFloatRes_FCOPYSIGN(SDNode *N,
+                                                SDValue &Lo, SDValue &Hi) {
+  SDValue Call = LibCallify(GetFPLibCall(N->getValueType(0),
+                                         RTLIB::COPYSIGN_F32,
+                                         RTLIB::COPYSIGN_F64,
+                                         RTLIB::COPYSIGN_F80,
+                                         RTLIB::COPYSIGN_PPCF128),
+                            N, false);
+  GetPairElements(Call, Lo, Hi);
+}
+
 void DAGTypeLegalizer::ExpandFloatRes_FCOS(SDNode *N,
                                            SDValue &Lo, SDValue &Hi) {
   SDValue Call = LibCallify(GetFPLibCall(N->getValueType(0),
diff --git a/lib/CodeGen/SelectionDAG/LegalizeTypes.h b/lib/CodeGen/SelectionDAG/LegalizeTypes.h
index 7c70663..9dd9796 100644
--- a/lib/CodeGen/SelectionDAG/LegalizeTypes.h
+++ b/lib/CodeGen/SelectionDAG/LegalizeTypes.h
@@ -458,6 +458,7 @@
   void ExpandFloatRes_FABS      (SDNode *N, SDValue &Lo, SDValue &Hi);
   void ExpandFloatRes_FADD      (SDNode *N, SDValue &Lo, SDValue &Hi);
   void ExpandFloatRes_FCEIL     (SDNode *N, SDValue &Lo, SDValue &Hi);
+  void ExpandFloatRes_FCOPYSIGN (SDNode *N, SDValue &Lo, SDValue &Hi);
   void ExpandFloatRes_FCOS      (SDNode *N, SDValue &Lo, SDValue &Hi);
   void ExpandFloatRes_FDIV      (SDNode *N, SDValue &Lo, SDValue &Hi);
   void ExpandFloatRes_FEXP      (SDNode *N, SDValue &Lo, SDValue &Hi);
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index a034b4c..3c0a230 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -4639,7 +4639,7 @@
     // can't be a library call.
     if (!F->hasLocalLinkage() && F->hasName()) {
       StringRef Name = F->getName();
-      if (Name == "copysign" || Name == "copysignf") {
+      if (Name == "copysign" || Name == "copysignf" || Name == "copysignl") {
         if (I.getNumOperands() == 3 &&   // Basic sanity checks.
             I.getOperand(1)->getType()->isFloatingPointTy() &&
             I.getType() == I.getOperand(1)->getType() &&
diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 4df4d77..f7ef2d6 100644
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -174,6 +174,10 @@
   Names[RTLIB::FLOOR_F64] = "floor";
   Names[RTLIB::FLOOR_F80] = "floorl";
   Names[RTLIB::FLOOR_PPCF128] = "floorl";
+  Names[RTLIB::COPYSIGN_F32] = "copysignf";
+  Names[RTLIB::COPYSIGN_F64] = "copysign";
+  Names[RTLIB::COPYSIGN_F80] = "copysignl";
+  Names[RTLIB::COPYSIGN_PPCF128] = "copysignl";
   Names[RTLIB::FPEXT_F32_F64] = "__extendsfdf2";
   Names[RTLIB::FPEXT_F16_F32] = "__gnu_h2f_ieee";
   Names[RTLIB::FPROUND_F32_F16] = "__gnu_f2h_ieee";