fix a bug in signed modular arithmetic

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

diff --git a/src/compiler/srctran.lisp b/src/compiler/srctran.lisp
index 3278e7b..7736902 100644 (file)
--- a/src/compiler/srctran.lisp
+++ b/src/compiler/srctran.lisp
@@ -3160,7 +3160,7 @@
         (when (and (numberp low) (numberp high))
           (let ((width (max (integer-length high) (integer-length low))))
             (multiple-value-bind (w kind)
-                (best-modular-version width t)
+                (best-modular-version (1+ width) t)
               (when w
                 ;; FIXME: This should be (CUT-TO-WIDTH NODE KIND W T).
                 ;; [ see comment above in LOGAND optimizer ]