Index: lib/Sema/SemaChecking.cpp
===================================================================
--- lib/Sema/SemaChecking.cpp
+++ lib/Sema/SemaChecking.cpp
@@ -919,6 +919,9 @@
   case Builtin::BI__builtin_isinf_sign:
   case Builtin::BI__builtin_isnan:
   case Builtin::BI__builtin_isnormal:
+  case Builtin::BI__builtin_signbit:
+  case Builtin::BI__builtin_signbitf:
+  case Builtin::BI__builtin_signbitl:
     if (SemaBuiltinFPClassification(TheCall, 1))
       return ExprError();
     break;
Index: test/Sema/builtins.c
===================================================================
--- test/Sema/builtins.c
+++ test/Sema/builtins.c
@@ -225,7 +225,7 @@
 
         strlcat(buf, b, sizeof(b)); // expected-warning {{size argument in 'strlcat' call appears to be size of the source; expected the size of the destination}} \
                                     // expected-note {{change size argument to be the size of the destination}}
-				    
+
         __builtin___strlcat_chk(buf, b, sizeof(b), __builtin_object_size(buf, 0)); // expected-warning {{size argument in '__builtin___strlcat_chk' call appears to be size of the source; expected the size of the destination}} \
                                                                                    // expected-note {{change size argument to be the size of the destination}} \
 				                                                   // expected-warning {{'__builtin___strlcat_chk' will always overflow destination buffer}}
@@ -253,3 +253,17 @@
   __sync_fetch_and_add(ptr, 1); // expected-error{{address argument to atomic builtin cannot be const-qualified ('const int *' invalid)}}
   __atomic_fetch_add(ptr, 1, 0);  // expected-error {{address argument to atomic operation must be a pointer to non-const type ('const int *' invalid)}}
 }
+
+void test22(void) {
+  (void)__builtin_signbit(); // expected-error{{too few arguments to function call, expected 1, have 0}}
+  (void)__builtin_signbit(1.0, 2.0, 3.0); // expected-error{{too many arguments to function call, expected 1, have 3}}
+  (void)__builtin_signbit(1); // expected-error {{floating point classification requires argument of floating point type (passed in 'int')}}
+
+  (void)__builtin_signbitf(); // expected-error{{too few arguments to function call, expected 1, have 0}}
+  (void)__builtin_signbitf(1.0, 2.0, 3.0); // expected-error{{too many arguments to function call, expected 1, have 3}}
+  (void)__builtin_signbitf(1);
+
+  (void)__builtin_signbitl(); // expected-error{{too few arguments to function call, expected 1, have 0}}
+  (void)__builtin_signbitl(1.0, 2.0, 3.0); // expected-error{{too many arguments to function call, expected 1, have 3}}
+  (void)__builtin_signbitl(1);
+}