Index: lib/CodeGen/CGBuiltin.cpp
===================================================================
--- lib/CodeGen/CGBuiltin.cpp
+++ lib/CodeGen/CGBuiltin.cpp
@@ -1431,7 +1431,7 @@
     EmitNonNullArgCheck(RValue::get(Dest.getPointer()), E->getArg(0)->getType(),
                         E->getArg(0)->getExprLoc(), FD, 0);
     Builder.CreateMemSet(Dest, Builder.getInt8(0), SizeVal, false);
-    return RValue::get(Dest.getPointer());
+    return RValue::get(nullptr);
   }
   case Builtin::BImemcpy:
   case Builtin::BI__builtin_memcpy: {
Index: test/CodeGen/builtins.c
===================================================================
--- test/CodeGen/builtins.c
+++ test/CodeGen/builtins.c
@@ -176,6 +176,19 @@
 }
 // CHECK: }
 
+// CHECK-LABEL: define void @test_conditional_bzero
+void test_conditional_bzero() {
+  char dst[20];
+  int _sz = 20, len = 20;
+  return (_sz
+          ? ((_sz >= len)
+              ? __builtin_bzero(dst, len)
+              : foo())
+          : __builtin_bzero(dst, len));
+  // CHECK: call void @llvm.memset
+  // CHECK: call void @llvm.memset
+  // CHECK-NOT: phi
+}
 
 // CHECK-LABEL: define void @test_float_builtins
 void test_float_builtins(float F, double D, long double LD) {