diff --git a/lib/CodeGen/CGBuiltin.cpp b/lib/CodeGen/CGBuiltin.cpp
index 4c401c5..59ed313 100644
--- a/lib/CodeGen/CGBuiltin.cpp
+++ b/lib/CodeGen/CGBuiltin.cpp
@@ -229,6 +229,35 @@
 
     return RValue::get(Result);
   }
+  
+  case Builtin::BI__builtin_conj:
+  case Builtin::BI__builtin_conjf:
+  case Builtin::BI__builtin_conjl: {
+    ComplexPairTy ComplexVal = EmitComplexExpr(E->getArg(0));
+    Value *Real = ComplexVal.first;
+    Value *Imag = ComplexVal.second;
+    Value *Zero = 
+      Imag->getType()->isFPOrFPVectorTy() 
+        ? llvm::ConstantFP::getZeroValueForNegation(Imag->getType())
+        : llvm::Constant::getNullValue(Imag->getType());
+    
+    Imag = Builder.CreateFSub(Zero, Imag, "sub");
+    return RValue::getComplex(std::make_pair(Real, Imag));
+  }
+  case Builtin::BI__builtin_creal:
+  case Builtin::BI__builtin_crealf:
+  case Builtin::BI__builtin_creall: {
+    ComplexPairTy ComplexVal = EmitComplexExpr(E->getArg(0));
+    return RValue::get(ComplexVal.first);
+  }
+      
+  case Builtin::BI__builtin_cimag:
+  case Builtin::BI__builtin_cimagf:
+  case Builtin::BI__builtin_cimagl: {
+    ComplexPairTy ComplexVal = EmitComplexExpr(E->getArg(0));
+    return RValue::get(ComplexVal.second);
+  }
+      
   case Builtin::BI__builtin_ctzs:
   case Builtin::BI__builtin_ctz:
   case Builtin::BI__builtin_ctzl:
diff --git a/test/CodeGen/complex-builtints.c b/test/CodeGen/complex-builtints.c
new file mode 100644
index 0000000..09219cf
--- /dev/null
+++ b/test/CodeGen/complex-builtints.c
@@ -0,0 +1,71 @@
+// RUN: %clang_cc1 %s -O1 -emit-llvm -o - | FileCheck %s
+// rdar://8315199
+
+/* Test for builtin conj, creal, cimag.  */
+/* Origin: Joseph Myers <jsm28@cam.ac.uk> */
+
+extern float _Complex conjf (float _Complex);
+extern double _Complex conj (double _Complex);
+extern long double _Complex conjl (long double _Complex);
+
+extern float crealf (float _Complex);
+extern double creal (double _Complex);
+extern long double creall (long double _Complex);
+
+extern float cimagf (float _Complex);
+extern double cimag (double _Complex);
+extern long double cimagl (long double _Complex);
+
+extern void abort (void);
+extern void link_error (void);
+
+int
+main ()
+{
+  /* For each type, test both runtime and compile time (constant folding)
+     optimization.  */
+  volatile float _Complex fc = 1.0F + 2.0iF;
+  volatile double _Complex dc = 1.0 + 2.0i;
+  volatile long double _Complex ldc = 1.0L + 2.0iL;
+  /* Test floats.  */
+  if (__builtin_conjf (fc) != 1.0F - 2.0iF)
+    abort ();
+  if (__builtin_conjf (1.0F + 2.0iF) != 1.0F - 2.0iF)
+    link_error ();
+  if (__builtin_crealf (fc) != 1.0F)
+    abort ();
+  if (__builtin_crealf (1.0F + 2.0iF) != 1.0F)
+    link_error ();
+  if (__builtin_cimagf (fc) != 2.0F)
+    abort ();
+  if (__builtin_cimagf (1.0F + 2.0iF) != 2.0F)
+    link_error ();
+  /* Test doubles.  */
+  if (__builtin_conj (dc) != 1.0 - 2.0i)
+    abort ();
+  if (__builtin_conj (1.0 + 2.0i) != 1.0 - 2.0i)
+    link_error ();
+  if (__builtin_creal (dc) != 1.0)
+    abort ();
+  if (__builtin_creal (1.0 + 2.0i) != 1.0)
+    link_error ();
+  if (__builtin_cimag (dc) != 2.0)
+    abort ();
+  if (__builtin_cimag (1.0 + 2.0i) != 2.0)
+    link_error ();
+  /* Test long doubles.  */
+  if (__builtin_conjl (ldc) != 1.0L - 2.0iL)
+    abort ();
+  if (__builtin_conjl (1.0L + 2.0iL) != 1.0L - 2.0iL)
+    link_error ();
+  if (__builtin_creall (ldc) != 1.0L)
+    abort ();
+  if (__builtin_creall (1.0L + 2.0iL) != 1.0L)
+    link_error ();
+  if (__builtin_cimagl (ldc) != 2.0L)
+    abort ();
+  if (__builtin_cimagl (1.0L + 2.0iL) != 2.0L)
+    link_error ();
+}
+
+// CHECK-NOT: link_error