diff --git a/tcc.h b/tcc.h
index 124d7e5..156bdd0 100644
--- a/tcc.h
+++ b/tcc.h
@@ -267,7 +267,8 @@ typedef struct AttributeDef {
       func_export   : 1,
       func_import   : 1,
       func_args     : 5,
-      fill          : 16;
+      mode          : 4,
+      fill          : 12;
     struct Section *section;
 } AttributeDef;
 
@@ -278,6 +279,7 @@ typedef struct AttributeDef {
 #define FUNC_ARGS(r) (((AttributeDef*)&(r))->func_args)
 #define FUNC_ALIGN(r) (((AttributeDef*)&(r))->aligned)
 #define FUNC_PACKED(r) (((AttributeDef*)&(r))->packed)
+#define ATTR_MODE(r)  (((AttributeDef*)&(r))->mode)
 #define INT_ATTR(ad) (*(int*)(ad))
 
 /* -------------------------------------------------- */
diff --git a/tccgen.c b/tccgen.c
index be8d80f..e761f91 100644
--- a/tccgen.c
+++ b/tccgen.c
@@ -2501,6 +2501,25 @@ static void parse_attribute(AttributeDef *ad)
             ad->func_call = FUNC_FASTCALLW;
             break;            
 #endif
+        case TOK_MODE:
+            skip('(');
+            switch(tok) {
+                case TOK_MODE_DI:
+                    ad->mode = VT_LLONG + 1;
+                    break;
+                case TOK_MODE_HI:
+                    ad->mode = VT_SHORT + 1;
+                    break;
+                case TOK_MODE_SI:
+                    ad->mode = VT_INT + 1;
+                    break;
+                default:
+                    warning("__mode__(%s) not supported\n", get_tok_str(tok, NULL));
+                    break;
+            }
+            next();
+            skip(')');
+            break;
         case TOK_DLLEXPORT:
             ad->func_export = 1;
             break;
@@ -2874,6 +2893,10 @@ static int parse_btype(CType *type, AttributeDef *ad)
         case TOK_ATTRIBUTE1:
         case TOK_ATTRIBUTE2:
             parse_attribute(ad);
+            if (ATTR_MODE(ad)) {
+                u = ATTR_MODE(ad) -1;
+                t = (t & ~VT_BTYPE) | u;
+            }
             break;
             /* GNUC typeof */
         case TOK_TYPEOF1:
diff --git a/tcctok.h b/tcctok.h
index 889ba0b..9075865 100644
--- a/tcctok.h
+++ b/tcctok.h
@@ -104,6 +104,10 @@
      DEF(TOK_FASTCALL1, "fastcall")
      DEF(TOK_FASTCALL2, "__fastcall")
      DEF(TOK_FASTCALL3, "__fastcall__")
+     DEF(TOK_MODE, "__mode__")
+     DEF(TOK_MODE_DI, "__DI__")
+     DEF(TOK_MODE_HI, "__HI__")
+     DEF(TOK_MODE_SI, "__SI__")
      DEF(TOK_DLLEXPORT, "dllexport")
      DEF(TOK_DLLIMPORT, "dllimport")
      DEF(TOK_NORETURN1, "noreturn")