ETH:optimized double is_tagged check

a double version of is_tagged, uses "free lanes" in _mm_cmpeq_epi16
to check a second tag

this code was not yet tested for performance

Change-Id: I640017e1cc75c85a33d196ee911a7e4a512d9849
Signed-off-by: Eyal Bari <ebari@cisco.com>

diff --git a/src/vnet/ethernet/node.c b/src/vnet/ethernet/node.c
index 4529ca6..ce5b2c5 100755 (executable)
--- a/src/vnet/ethernet/node.c
+++ b/src/vnet/ethernet/node.c
@@ -285,6 +285,29 @@ determine_next_node (ethernet_main_t * em,
     }
 }
 
+static_always_inline int
+ethernet_frame_is_any_tagged (u16 type0, u16 type1)
+{
+#if __SSE4_2__
+  const __m128i ethertype_mask = _mm_set_epi16 (ETHERNET_TYPE_VLAN,
+                                               ETHERNET_TYPE_DOT1AD,
+                                               ETHERNET_TYPE_VLAN_9100,
+                                               ETHERNET_TYPE_VLAN_9200,
+                                               /* duplicate for type1 */
+                                               ETHERNET_TYPE_VLAN,
+                                               ETHERNET_TYPE_DOT1AD,
+                                               ETHERNET_TYPE_VLAN_9100,
+                                               ETHERNET_TYPE_VLAN_9200);
+
+  __m128i r =
+    _mm_set_epi16 (type0, type0, type0, type0, type1, type1, type1, type1);
+  r = _mm_cmpeq_epi16 (ethertype_mask, r);
+  return !_mm_test_all_zeros (r, r);
+#else
+  return ethernet_frame_is_tagged (type0) || ethernet_frame_istagged (type1);
+#endif
+}
+
 static_always_inline uword
 ethernet_input_inline (vlib_main_t * vm,
                       vlib_node_runtime_t * node,
@@ -377,8 +400,7 @@ ethernet_input_inline (vlib_main_t * vm,
 
          /* Speed-path for the untagged case */
          if (PREDICT_TRUE (variant == ETHERNET_INPUT_VARIANT_ETHERNET
-                           && !ethernet_frame_is_tagged (type0)
-                           && !ethernet_frame_is_tagged (type1)))
+                           && !ethernet_frame_is_any_tagged (type0, type1)))
            {
              main_intf_t *intf0;
              subint_config_t *subint0;