[cmucl-cvs] CMUCL commit: src/code (reader.lisp)

[Raymond Toy]

    Date: Wednesday, January 26, 2011 @ 19:49:32
  Author: rtoy
    Path: /project/cmucl/cvsroot/src/code

Modified: reader.lisp

Micro optimization:  In SET-CMT-ENTRY, if the char-code is above
attribute-table-limit and if the newvalue is #'read-token, we don't
actually add the entry to the character-macro-hash-table, because that
is the default value for the hash-table.  This helps to keep the
hash-table size small.


-------------+
 reader.lisp |   12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)


Index: src/code/reader.lisp
diff -u src/code/reader.lisp:1.67 src/code/reader.lisp:1.68
--- src/code/reader.lisp:1.67	Tue Apr 20 13:57:45 2010
+++ src/code/reader.lisp	Wed Jan 26 19:49:32 2011
@@ -5,7 +5,7 @@
 ;;; Carnegie Mellon University, and has been placed in the public domain.
 ;;;
 (ext:file-comment
-  "$Header: /project/cmucl/cvsroot/src/code/reader.lisp,v 1.67 2010-04-20 17:57:45 rtoy Rel $")
+  "$Header: /project/cmucl/cvsroot/src/code/reader.lisp,v 1.68 2011-01-27 00:49:32 rtoy Exp $")
 ;;;
 ;;; **********************************************************************
 ;;;
@@ -275,8 +275,14 @@
 	(setf (elt (the simple-vector (character-macro-table rt))
 		   code)
 	      (coerce newvalue 'function))
-	(setf (gethash code (character-macro-hash-table rt))
-	      (coerce newvalue 'function)))))
+	(let ((f (coerce newvalue 'function)))
+	  ;; Don't add an entry if the function would be the same as
+	  ;; the default.  This needs to be coordinated with
+	  ;; GET-CMT-ENTRY above.
+	  (if (eq f #'read-token)
+	      f
+	      (setf (gethash code (character-macro-hash-table rt))
+		    f))))))
 
 (defun undefined-macro-char (stream char)
   (unless *read-suppress*