Changeset b429c16 in git

Timestamp:

Dec 6, 2006, 5:59:49 PM (17 years ago)

Author:

Oliver Wienand <wienand@…>

Branches:

(u'spielwiese', '91fdef05f09f54b8d58d92a472e9c4a43aa4656f')

Children:

bd860d3f60d5d79e7b9c070896415f1cf8e9e66a

Parents:

c80090fcc5ae3a1dc7fbae1ee5ff9decaf6e9dec

Message:

Division durch Nullteiler erlaubt


git-svn-id: file:///usr/local/Singular/svn/trunk@9541 2c84dea3-7e68-4137-9b89-c4e89433aadc

File:

• kernel/rmodulo2m.cc (modified) (3 diffs)

kernel/rmodulo2m.cc

@@ -2 +2 @@
 *  Computer Algebra System SINGULAR     *
 ****************************************/
-/* $Id: rmodulo2m.cc,v 1.4 2006-03-20 20:33:57 wienand Exp $ */
+/* $Id: rmodulo2m.cc,v 1.5 2006-12-06 16:59:49 wienand Exp $ */
 /*
 * ABSTRACT: numbers modulo 2^m
@@ -58 +58 @@
 /*
  * Give the largest non unit k, such that a = x * k, b = y * k has
- * a solution. 
+ * a solution.
  */
 number nr2mGcd (number a,number b,ring r)
@@ -246 +246 @@
   else if ((long)b%2==0)
   {
-    WerrorS("div by zero divisor");
-    return (number)0;
-  }
-  else
-  {
-    return (number) nr2mMult(a, nr2mInversM(b));
-  }
+    if ((long)b != 0)
+    {
+      while ((long) b%2 == 0 && (long) a%2 == 0)
+      {
+        a = (number) ((long) a / 2);
+        b = (number) ((long) b / 2);
+      }
+    }
+    if ((long) b%2 == 0)
+    {
+      WerrorS("div by zero divisor");
+      return (number)0;
+    }
+  }
+  return (number) nr2mMult(a, nr2mInversM(b));
 }