--- rxvt-unicode/src/rxvtutil.h	2007/12/14 11:11:31	1.36
+++ rxvt-unicode/src/rxvtutil.h	2008/07/21 16:51:31	1.37
@@ -15,10 +15,18 @@
 
 #if __GNUC__ >= 4
 # define rxvt_attribute(x) __attribute__(x)
+# define expect(expr,value)         __builtin_expect ((expr),(value))
 #else
 # define rxvt_attribute(x)
+# define expect(expr,value)         (expr)
 #endif
 
+// put into ifs if you are very sure that the expression
+// is mostly true or mosty false. note that these return
+// booleans, not the expression.
+#define expect_false(expr) expect ((expr) != 0, 0)
+#define expect_true(expr)  expect ((expr) != 0, 1)
+
 #define NORETURN rxvt_attribute ((noreturn))
 #define UNUSED   rxvt_attribute ((unused))
 #define CONST    rxvt_attribute ((const))