don't assume only bits are looked for in bit-vectors

[sbcl.git] / src / compiler / seqtran.lisp

diff --git a/src/compiler/seqtran.lisp b/src/compiler/seqtran.lisp
index ac8cd0f..0b52e48 100644 (file)
--- a/src/compiler/seqtran.lisp
+++ b/src/compiler/seqtran.lisp
@@ -1453,20 +1453,20 @@
   (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)))))
+  (catch 'not-a-bit
+    `(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 (throw 'not-a-bit `(values nil nil))))
+                     `(%bit-position 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)