from-end start end key test))
(deftransform %find-position ((item sequence from-end start end key test)
+ (t bit-vector t t t t t)
+ * :node node)
+ (when (and test (lvar-fun-is test '(eq eql equal)))
+ (setf test nil))
+ (when (and key (lvar-fun-is key '(identity)))
+ (setf key nil))
+ (when (or test key)
+ (delay-ir1-transform node :optimize)
+ (give-up-ir1-transform "non-trivial :KEY or :TEST"))
+ `(with-array-data ((bits sequence :offset-var offset)
+ (start start)
+ (end end)
+ :check-fill-pointer t)
+ (let ((p ,(if (constant-lvar-p item)
+ (case (lvar-value item)
+ (0 `(%bit-position/0 bits from-end start end))
+ (1 `(%bit-position/1 bits from-end start end))
+ (otherwise
+ (abort-ir1-transform)))
+ `(%bit-position (the bit item) bits from-end start end))))
+ (if p
+ (values item (the index (- (truly-the index p) offset)))
+ (values nil nil)))))
+
+(deftransform %find-position ((item sequence from-end start end key test)
(character string t t t function function)
*
:policy (> speed space))