From: Guillermo J. Rozas <edu/mit/csail/zurich/gjr>
Date: Thu, 19 Jul 1990 19:11:32 +0000 (+0000)
Subject: Take word size into account.  Shifts past fixnum size always return
X-Git-Tag: 20090517-FFI~11316
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=ae54c2f1ffa1606b1b757f40d5ff93f1afc06e01;p=mit-scheme.git

Take word size into account.  Shifts past fixnum size always return
0.
---

diff --git a/v7/src/microcode/fixnum.c b/v7/src/microcode/fixnum.c
index 9f43f5f6d..0a718316e 100644
--- a/v7/src/microcode/fixnum.c
+++ b/v7/src/microcode/fixnum.c
@@ -1,6 +1,6 @@
 /* -*-C-*-
 
-$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/microcode/fixnum.c,v 9.31 1990/07/15 22:49:32 jinx Exp $
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/microcode/fixnum.c,v 9.32 1990/07/19 19:11:32 jinx Rel $
 
 Copyright (c) 1987, 1988, 1989, 1990 Massachusetts Institute of Technology
 
@@ -313,11 +313,11 @@ DEFINE_PRIMITIVE ("FIXNUM-LSH", Prim_fixnum_lsh, 2, 2, 0)
 
   if (y < 0)
   {
-    z = (x >> (- y));
+    z = ((y < (- FIXNUM_LENGTH)) ? 0 : (x >> (- y)));
   }
   else
   {
-    z = (x << y);
+    z = ((y > FIXNUM_LENGTH) ? 0 : (x << y));
   }
   return (LONG_TO_FIXNUM (z));
 }