+extern unsigned int ya_random (void);
+extern void ya_rand_init (unsigned int);
+
+
+#if defined (__GNUC__) && (__GNUC__ >= 2)
+ /* Implement frand using GCC's statement-expression extension. */
+
+# define frand(f) \
+ ({ double tmp = (((double) random()) / \
+ (((double) ((unsigned int)~0)) / ((double) (f)))); \
+ tmp < 0 ? (-tmp) : tmp; })
+
+#else /* not GCC2 - implement frand using a global variable.*/
+
+static double _frand_tmp_;
+# define frand(f) \
+ (_frand_tmp_ = (((double) random()) / \
+ (((double) ((unsigned int)~0)) / ((double) (f)))), \
+ _frand_tmp_ < 0 ? (-_frand_tmp_) : _frand_tmp_)
+
+#endif /* not GCC2 */