Changeset 6041 for trunk/j/src/org/armedbear/lisp/ldb.lisp

Timestamp:

02/28/04 18:40:42 (20 years ago)

Author:

piso

Message:

%LDB

File:

• trunk/j/src/org/armedbear/lisp/ldb.lisp (modified) (3 diffs)

trunk/j/src/org/armedbear/lisp/ldb.lisp

@@ -1 +1 @@
 ;;; ldb.lisp
 ;;;
-;;; Copyright (C) 2003 Peter Graves
-;;; $Id: ldb.lisp,v 1.2 2003-09-12 14:16:44 piso Exp $
+;;; Copyright (C) 2003-2004 Peter Graves
+;;; $Id: ldb.lisp,v 1.3 2004-02-28 18:40:08 piso Exp $
 ;;;
 ;;; This program is free software; you can redistribute it and/or
@@ -18 +18 @@
 ;;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 
+(in-package "SYSTEM")
+
 (defun byte (size position)
   (cons size position))
@@ -26 +28 @@
 (defun byte-position (bytespec)
   (cdr bytespec))
+
+;; For the LDB compiler macro.
+(defun %ldb (size position integer)
+  (logand (ash integer (- position))
+    (1- (ash 1 size))))
 
 (defun ldb (bytespec integer)