tcg/loongarch64: Implement the memory barrier op

Signed-off-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20211221054105.178795-9-git@xen0n.name>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

tcg/loongarch64/tcg-target.c.inc

@@ -234,3 +234,35 @@ static bool patch_reloc(tcg_insn_unit *code_ptr, int type,
         g_assert_not_reached();
     }
 }
+
+#include "tcg-insn-defs.c.inc"
+
+/*
+ * TCG intrinsics
+ */
+
+static void tcg_out_mb(TCGContext *s, TCGArg a0)
+{
+    /* Baseline LoongArch only has the full barrier, unfortunately.  */
+    tcg_out_opc_dbar(s, 0);
+}
+
+/*
+ * Entry-points
+ */
+
+static void tcg_out_op(TCGContext *s, TCGOpcode opc,
+                       const TCGArg args[TCG_MAX_OP_ARGS],
+                       const int const_args[TCG_MAX_OP_ARGS])
+{
+    TCGArg a0 = args[0];
+
+    switch (opc) {
+    case INDEX_op_mb:
+        tcg_out_mb(s, a0);
+        break;
+
+    default:
+        g_assert_not_reached();
+    }
+}