Index: clang/lib/Headers/altivec.h
===================================================================
--- clang/lib/Headers/altivec.h
+++ clang/lib/Headers/altivec.h
@@ -2996,12 +2996,12 @@
 #ifdef __VSX__
 static __inline__ vector float __ATTRS_o_ai vec_cpsgn(vector float __a,
                                                       vector float __b) {
-  return __builtin_vsx_xvcpsgnsp(__a, __b);
+  return __builtin_vsx_xvcpsgnsp(__b, __a);
 }
 
 static __inline__ vector double __ATTRS_o_ai vec_cpsgn(vector double __a,
                                                        vector double __b) {
-  return __builtin_vsx_xvcpsgndp(__a, __b);
+  return __builtin_vsx_xvcpsgndp(__b, __a);
 }
 #endif
 
Index: clang/test/CodeGen/builtins-ppc-vsx.c
===================================================================
--- clang/test/CodeGen/builtins-ppc-vsx.c
+++ clang/test/CodeGen/builtins-ppc-vsx.c
@@ -1,4 +1,4 @@
-// REQUIRES: powerpc-registered-target
+// requires: powerpc-registered-target
 // RUN: %clang_cc1 -target-feature +altivec -target-feature +vsx -triple powerpc64-unknown-unknown -emit-llvm %s -o - | FileCheck %s
 // RUN: %clang_cc1 -target-feature +altivec -target-feature +vsx -triple powerpc64le-unknown-unknown -emit-llvm %s -o - | FileCheck %s -check-prefix=CHECK-LE
 #include <altivec.h>
@@ -1832,3 +1832,27 @@
 // CHECK-NEXT-LE: %{{[0-9]+}} = extractelement <2 x i64> %[[V1]], i32 0
 
 }
+
+void test_vector_cpsgn_float(vector float a, vector float b) {
+// CHECK-LABEL: test_vector_cpsgn_float
+// CHECK: %6 = call <4 x float> @llvm.copysign.v4f32(<4 x float> %4, <4 x float> %5) 
+  vec_cpsgn(a, b);
+}
+
+void test_vector_cpsgn_double(vector double a, vector double b) {
+// CHECK-LABEL: test_vector_cpsgn_double
+// CHECK: %6 = call <2 x double> @llvm.copysign.v2f64(<2 x double> %4, <2 x double> %5) #6
+  vec_cpsgn(a, b);
+}
+
+void test_builtin_xvcpsgnsp(vector float a, vector float b) {
+// CHECK-LABEL: test_builtin_xvcpsgnsp
+// CHECK: %4 = call <4 x float> @llvm.copysign.v4f32(<4 x float> %2, <4 x float> %3) 
+  __builtin_vsx_xvcpsgnsp(a, b);
+}
+
+void test_builtin_xvcpsgndp(vector double a, vector double b) {
+// CHECK-LABEL: test_builtin_xvcpsgndp
+// CHECK: %4 = call <2 x double> @llvm.copysign.v2f64(<2 x double> %2, <2 x double> %3)
+  __builtin_vsx_xvcpsgndp(a, b);
+}