BigInteger.abs and .neg wrong result on ARM

martin — Tue, 20 Jul 2010 10:49:13 -0000

The BigInteger.abs and BigInteger.neg functions give a wrong result when called with the argument Integer.MIN_VALUE on an ARM9 platform. The problem occurs in BigInteger.setNegative, where the expression

(-(long)len)

gives a wrong result. See the attached file for an example to reproduce the error and the output of that program.

jamvm -version:
java version "1.5.0"
JamVM version 1.5.4
Copyright (C) 2003-2010 Robert Lougher <rob@jamvm.org.uk>

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2,
or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.

Build information:

Execution Engine: inline-threaded interpreter with stack-caching
Compiled with: gcc 4.2.4

Boot Library Path: /usr/lib/classpath
Boot Class Path: /usr/share/jamvm/classes.zip:/usr/share/classpath/glibj.zip

Platform:

uname -a
Linux at91sam9g20ek 2.6.30 #5 Mon Jul 12 13:19:09 CEST 2010 armv5tejl unknown

Recent changes to 49: BigInteger.abs and .neg wrong result on ARM

BigInteger.abs and .neg wrong result on ARM