X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcompiler%2Fseqtran.lisp;h=0b52e48c455bd6ef9fae87518990b7aba16f9063;hb=bcd323c39d6f5f80020ba4a5d9eb8d348c6cc499;hp=ac8cd0fd14e5305b56443557a22e95686e05ebb8;hpb=41cb424785ec6daf0263acb1a6a8af9d41708990;p=sbcl.git

diff --git a/src/compiler/seqtran.lisp b/src/compiler/seqtran.lisp
index ac8cd0f..0b52e48 100644
--- 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)