diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp
index 08b60671a63..ff1124ad878 100644
--- a/lib/Analysis/ConstantFolding.cpp
+++ b/lib/Analysis/ConstantFolding.cpp
@@ -1195,6 +1195,7 @@ bool llvm::canConstantFoldCallTo(const Function *F) {
   case Intrinsic::cttz:
   case Intrinsic::fma:
   case Intrinsic::fmuladd:
+  case Intrinsic::copysign:
   case Intrinsic::sadd_with_overflow:
   case Intrinsic::uadd_with_overflow:
   case Intrinsic::ssub_with_overflow:
@@ -1532,6 +1533,12 @@ static Constant *ConstantFoldScalarCall(StringRef Name, unsigned IntrinsicID,
         if (IntrinsicID == Intrinsic::pow) {
           return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty);
         }
+        if (IntrinsicID == Intrinsic::copysign) {
+          APFloat V1 = Op1->getValueAPF();
+          APFloat V2 = Op2->getValueAPF();
+          V1.copySign(V2);
+          return ConstantFP::get(Ty->getContext(), V1);
+        }
         if (!TLI)
           return 0;
         if (Name == "pow" && TLI->has(LibFunc::pow))
diff --git a/test/Transforms/InstCombine/copysign.ll b/test/Transforms/InstCombine/copysign.ll
new file mode 100644
index 00000000000..556b79999b0
--- /dev/null
+++ b/test/Transforms/InstCombine/copysign.ll
@@ -0,0 +1,49 @@
+; RUN: opt -S -instcombine < %s | FileCheck %s
+
+declare float @llvm.copysign.f32(float, float) #0
+declare double @llvm.copysign.f64(double, double) #0
+
+; CHECK-LABEL: @constant_fold_copysign_f32_01
+; CHECK-NEXT: ret float -1.000000e+00
+define float @constant_fold_copysign_f32_01() #0 {
+  %x = call float @llvm.copysign.f32(float 1.0, float -2.0) #0
+  ret float %x
+}
+
+; CHECK-LABEL: @constant_fold_copysign_f32_02
+; CHECK-NEXT: ret float 2.000000e+00
+define float @constant_fold_copysign_f32_02() #0 {
+  %x = call float @llvm.copysign.f32(float -2.0, float 1.0) #0
+  ret float %x
+}
+
+; CHECK-LABEL: @constant_fold_copysign_f32_03
+; CHECK-NEXT: ret float -2.000000e+00
+define float @constant_fold_copysign_f32_03() #0 {
+  %x = call float @llvm.copysign.f32(float -2.0, float -1.0) #0
+  ret float %x
+}
+
+; CHECK-LABEL: @constant_fold_copysign_f64_01
+; CHECK-NEXT: ret double -1.000000e+00
+define double @constant_fold_copysign_f64_01() #0 {
+  %x = call double @llvm.copysign.f64(double 1.0, double -2.0) #0
+  ret double %x
+}
+
+; CHECK-LABEL: @constant_fold_copysign_f64_02
+; CHECK-NEXT: ret double 1.000000e+00
+define double @constant_fold_copysign_f64_02() #0 {
+  %x = call double @llvm.copysign.f64(double -1.0, double 2.0) #0
+  ret double %x
+}
+
+; CHECK-LABEL: @constant_fold_copysign_f64_03
+; CHECK-NEXT: ret double -1.000000e+00
+define double @constant_fold_copysign_f64_03() #0 {
+  %x = call double @llvm.copysign.f64(double -1.0, double -2.0) #0
+  ret double %x
+}
+
+
+attributes #0 = { nounwind readnone }