X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fcode%2Fdeftypes-for-target.lisp;h=4e657c9ddeba23809a9f9316db204f9d26671c2d;hb=4ed3f0d08c3a57a6762018d9622f253ab9d0f2b6;hp=0928858c8100d3485579523ed01653fa505f4ee1;hpb=403bacffd903f8c5787a182f4133cffc69b55dc0;p=sbcl.git

diff --git a/src/code/deftypes-for-target.lisp b/src/code/deftypes-for-target.lisp
index 0928858..4e657c9 100644
--- a/src/code/deftypes-for-target.lisp
+++ b/src/code/deftypes-for-target.lisp
@@ -33,7 +33,7 @@
 
 (sb!xc:deftype signed-byte (&optional s)
   (cond ((eq s '*) 'integer)
-	((and (integerp s) (> s 1))
+	((and (integerp s) (> s 0))
 	 (let ((bound (ash 1 (1- s))))
 	   `(integer ,(- bound) ,(1- bound))))
 	(t
@@ -46,6 +46,14 @@
 	(t
 	 (error "bad size specified for UNSIGNED-BYTE type specifier: ~S" s))))
 
+;;; ANSI got UNSIGNED-BYTE wrong, prohibiting (UNSIGNED-BYTE 0).
+;;; Since this is actually a substantial impediment to clarity...
+(sb!xc:deftype unsigned-byte* (&optional s)
+  (cond
+    ((eq s '*) '(integer 0))
+    ((zerop s) '(integer 0 0))
+    (t `(unsigned-byte ,s))))
+
 (sb!xc:deftype bit () '(integer 0 1))
 
 (sb!xc:deftype compiled-function () 'function)