diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 43a83566..a8e504e 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -1177,6 +1177,18 @@ aarch64_expand_mov_immediate (rtx dest, rtx imm)
 	}
     }
 
+  /* Look for case where upper 16 bits are set, so we can use MOVN.  */
+  if ((val & 0xffff000000000000ll) == 0xffff000000000000ll)
+    {
+      emit_insn (gen_rtx_SET (VOIDmode, dest,
+			      GEN_INT (~ (~val & (0xffffll << 32)))));
+      emit_insn (gen_insv_immdi (dest, GEN_INT (16),
+				 GEN_INT ((val >> 16) & 0xffff)));
+      emit_insn (gen_insv_immdi (dest, GEN_INT (0),
+				 GEN_INT (val & 0xffff)));
+      return;
+    }
+
  simple_sequence:
   first = true;
   mask = 0xffff;
diff --git a/gcc/testsuite/gcc.target/aarch64/movn_1.c b/gcc/testsuite/gcc.target/aarch64/movn_1.c
new file mode 100644
index 0000000..cc11ade
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/movn_1.c
@@ -0,0 +1,27 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fno-inline --save-temps" } */
+
+extern void abort (void);
+
+long long
+foo ()
+{
+  /* { dg-final { scan-assembler "mov\tx\[0-9\]+, -71536975282177" } } */
+  return 0xffffbeefcafebabell;
+}
+
+long long
+merge4 (int a, int b, int c, int d)
+{
+  return ((long long) a << 48 | (long long) b << 32
+	  | (long long) c << 16 | (long long) d);
+}
+
+int main ()
+{
+  if (foo () != merge4 (0xffff, 0xbeef, 0xcafe, 0xbabe))
+    abort ();
+  return 0;
+}
+
+/* { dg-final { cleanup-saved-temps } } */