diff --git a/clang/lib/CodeGen/CGBuiltin.cpp b/clang/lib/CodeGen/CGBuiltin.cpp
--- a/clang/lib/CodeGen/CGBuiltin.cpp
+++ b/clang/lib/CodeGen/CGBuiltin.cpp
@@ -1938,7 +1938,10 @@
   }
   case Builtin::BI__builtin_conj:
   case Builtin::BI__builtin_conjf:
-  case Builtin::BI__builtin_conjl: {
+  case Builtin::BI__builtin_conjl:
+  case Builtin::BIconj:
+  case Builtin::BIconjf:
+  case Builtin::BIconjl: {
     ComplexPairTy ComplexVal = EmitComplexExpr(E->getArg(0));
     Value *Real = ComplexVal.first;
     Value *Imag = ComplexVal.second;
diff --git a/clang/test/CodeGen/complex-libcalls-2.c b/clang/test/CodeGen/complex-libcalls-2.c
new file mode 100644
--- /dev/null
+++ b/clang/test/CodeGen/complex-libcalls-2.c
@@ -0,0 +1,20 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -w -S -o - -emit-llvm              %s | FileCheck %s
+// RUN: %clang_cc1 -triple x86_64-unknown-unknown -w -S -o - -emit-llvm -fmath-errno %s | FileCheck %s
+
+float _Complex test_conjf(float _Complex x) {
+// CHECK-LABEL: @test_conjf(
+// CHECK: fneg float %x.imag
+  return conjf(x);
+}
+
+double _Complex test_conj(double _Complex x) {
+// CHECK-LABEL: @test_conj(
+// CHECK: fneg double %x.imag
+  return conj(x);
+}
+
+long double _Complex test_conjl(long double _Complex x) {
+// CHECK-LABEL: @test_conjl(
+// CHECK: fneg x86_fp80 %x.imag
+  return conjl(x);
+}
diff --git a/clang/test/CodeGen/complex-libcalls.c b/clang/test/CodeGen/complex-libcalls.c
--- a/clang/test/CodeGen/complex-libcalls.c
+++ b/clang/test/CodeGen/complex-libcalls.c
@@ -112,12 +112,10 @@
 
   conj(f);       conjf(f);      conjl(f);
 
-// NO__ERRNO: declare { double, double } @conj(double, double) [[READNONE:#[0-9]+]]
-// NO__ERRNO: declare <2 x float> @conjf(<2 x float>) [[READNONE]]
-// NO__ERRNO: declare { x86_fp80, x86_fp80 } @conjl({ x86_fp80, x86_fp80 }* byval({ x86_fp80, x86_fp80 }) align 16) [[NOT_READNONE]]
-// HAS_ERRNO: declare { double, double } @conj(double, double) [[READNONE:#[0-9]+]]
-// HAS_ERRNO: declare <2 x float> @conjf(<2 x float>) [[READNONE]]
-// HAS_ERRNO: declare { x86_fp80, x86_fp80 } @conjl({ x86_fp80, x86_fp80 }* byval({ x86_fp80, x86_fp80 }) align 16) [[NOT_READNONE]]
+// NO__ERRNO-NOT: .conj
+// NO__ERRNO-NOT: @conj
+// HAS_ERRNO-NOT: .conj
+// HAS_ERRNO-NOT: @conj
 
   clog(f);       clogf(f);      clogl(f);
 
@@ -133,7 +131,7 @@
 // NO__ERRNO: declare { double, double } @cproj(double, double) [[READNONE]]
 // NO__ERRNO: declare <2 x float> @cprojf(<2 x float>) [[READNONE]]
 // NO__ERRNO: declare { x86_fp80, x86_fp80 } @cprojl({ x86_fp80, x86_fp80 }* byval({ x86_fp80, x86_fp80 }) align 16) [[NOT_READNONE]]
-// HAS_ERRNO: declare { double, double } @cproj(double, double) [[READNONE]]
+// HAS_ERRNO: declare { double, double } @cproj(double, double) [[READNONE:#[0-9]+]]
 // HAS_ERRNO: declare <2 x float> @cprojf(<2 x float>) [[READNONE]]
 // HAS_ERRNO: declare { x86_fp80, x86_fp80 } @cprojl({ x86_fp80, x86_fp80 }* byval({ x86_fp80, x86_fp80 }) align 16) [[NOT_READNONE]]