OpenRISC 1000

<p> The specification of <tt>l.xori</tt> was recently updated (see <a href="http://opencores.org/bug,view,1789">Bug 1789</a>). The implementation in Or1ksim does not match this behavior. </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> This architectural causes problems, since it changes the functional behavior of l.xori. In the absence of a l.not instruction </p> <pre> l.xori rD,rA,-1 </pre> <p> is a convenient way to invert rA. This is heavily used by GCC. </p> <p> This behavior will be made a configuration option in Or1ksim, but the default will be to treat this as a signed immediate. </p> <p> Jeremy </p>

<p> New configuration option --enable-unsigned-xori added to Or1ksim and committed to top of tree. </p> <p> This is as far as can be done with the current architecture. To make this the default would break all the existing code. </p> <p> Marking closed. </p> <p> Jeremy </p>