OpenRISC 1000

<p> Or1ksim has a configuration parameter which controls whether arithmetic instructions set the overflow flag. By default this is off, and applies to all arithmetic and logic instructions. </p> <p> This should not be an option. The setting or otherwise of the carry flag specified in each instruction's definition. </p> <p> Affects the following instructions, which should always set the overflow flag if approriate: <tt>l.add</tt>, <tt>l.addc</tt>, <tt>l.div</tt>, <tt>l.divu</tt>, <tt>l.mul</tt> and <tt>l.sub</tt>. </p> <p> Affects the following instructions, which should never set the overflow flag: <tt>l.and</tt>, <tt>l.or</tt>, <tt>l.sll</tt>, <tt>l.sra</tt>, <tt>l.srl</tt> and <tt>l.xor</tt>. </p> <p> A number of ALU operations are missing. When implemented, these should set the overflow flag appropriately. </p> <p> Jeremy </p> <p> -- <br /> Tel: +44 (1590) 610184<br /> Cell: +44 (7970) 676050<br /> SkypeID: jeremybennett<br /> Email: <a href="mailto:jeremy.bennett@embecosm.com">jeremy.bennett@embecosm.com</a><br /> Web: <a href="http://www.embecosm.com">www.embecosm.com</a> </p>

<p> Corrected in top of tree. Regression tests added. </p> <p> Marking closed. </p> <p> Jeremy </p>