diff --git a/util/mcgg/iburg.c b/util/mcgg/iburg.c
index 0477f216b..9979627c0 100644
--- a/util/mcgg/iburg.c
+++ b/util/mcgg/iburg.c
@@ -16,7 +16,10 @@
 #include "smap.h"
 #include "mcgg.h"
 
-static char rcsid[] = "$Id$";
+#define REGATTR_INT 0
+#define REGATTR_LONG 1
+#define REGATTR_FLOAT 2
+#define REGATTR_DOUBLE 3
 
 int maxcost = SHRT_MAX / 2;
 
@@ -162,6 +165,18 @@ int main(int argc, char* argv[])
 		rule(&reg, tree(&NOPL, tree(&reg, NULL, NULL), NULL))->cost = 1;
 		rule(&reg, tree(&NOPD, tree(&reg, NULL, NULL), NULL))->cost = 1;
 		rule(NULL, tree(&RET, NULL, NULL))->cost = 1;
+
+	}
+
+	{
+		struct regattr* attr = makeregattr("int");
+		assert(attr->number == REGATTR_INT);
+		attr = makeregattr("long");
+		assert(attr->number == REGATTR_LONG);
+		attr = makeregattr("float");
+		assert(attr->number == REGATTR_FLOAT);
+		attr = makeregattr("double");
+		assert(attr->number == REGATTR_DOUBLE);
 	}
 
 	yyin = infp;
@@ -612,7 +627,8 @@ static void emitregisterattrs(void)
 		assert(rc->number == i);
 
 		print("%1\"%s\",\n", rc->name);
-		printh("#define %P%s_ATTR (1U<<%d)\n", rc->name, rc->number);
+		if (rc->number > REGATTR_DOUBLE)
+			printh("#define %P%s_ATTR (1U<<%d)\n", rc->name, rc->number);
 	}
 	print("};\n\n");
 	printh("\n");
@@ -655,7 +671,10 @@ static void emitregisters(void)
 	for (i=0; i<registers.count; i++)
 	{
 		struct reg* r = registers.item[i].right;
+		uint32_t type = r->attrs & TYPE_ATTRS;
 		assert(r->number == i);
+		if (type & (type-1))
+			yyerror("register %s has more than one type attribute set", r->name);
 
 		print("%1{ \"%s\", 0x%x, %Pregister_names_%d_%s, %Pregister_aliases_%d_%s },\n",
 			r->name, r->attrs, i, r->name, i, r->name);
diff --git a/util/mcgg/ircodes.h b/util/mcgg/ircodes.h
index d9c05126f..16be32a5b 100644
--- a/util/mcgg/ircodes.h
+++ b/util/mcgg/ircodes.h
@@ -17,6 +17,11 @@ struct ir_data
 
 extern const struct ir_data ir_data[];
 
+#define burm_int_ATTR (1U<<0)
+#define burm_long_ATTR (1U<<1)
+#define burm_float_ATTR (1U<<2)
+#define burm_double_ATTR (1U<<3)
+
 #define TYPE_ATTRS \
     (burm_int_ATTR | burm_long_ATTR | burm_float_ATTR | burm_double_ATTR)