target/arm: Add fp16 support to vfp_expand_imm

Signed-off-by: NRichard Henderson <richard.henderson@linaro.org>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Message-id: 20180110063337.21538-3-richard.henderson@linaro.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

target/arm/translate-a64.c

@@ -5006,6 +5006,11 @@ static uint64_t vfp_expand_imm(int size, uint8_t imm8)
             (extract32(imm8, 0, 6) << 3);
         imm <<= 16;
         break;
+    case MO_16:
+        imm = (extract32(imm8, 7, 1) ? 0x8000 : 0) |
+            (extract32(imm8, 6, 1) ? 0x3000 : 0x4000) |
+            (extract32(imm8, 0, 6) << 6);
+        break;
     default:
         g_assert_not_reached();
     }