<br><br><div class="gmail_quote">On Wed, Jan 21, 2009 at 12:38 PM, Nicolas Cellier <span dir="ltr"><<a href="mailto:ncellier@ifrance.com">ncellier@ifrance.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div class="Ih2E3d">Eliot Miranda <eliot.miranda <at> <a href="http://gmail.com" target="_blank">gmail.com</a>> writes:<br>
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> Hi All,<br>
><br>
> anyone know the x86/IA32 really well? If so, read on. Otherwise save<br>
yourself the yawn.<br>
><br>
> I just tried to save an instruction in Cog;s generated bitShift: primitive.<br>
It seems to me that SARL (shift arithmetic right long) should set the sign flag<br>
based on the result, in fact it says as much in the manual; I quote from IA-32<br>
Intel® Architecture Software Developer's Manual Volume 2B: Instruction Set<br>
Reference, N-Z p 4-192<br>
></div></blockquote><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><div class="Ih2E3d"><br>
<br>
</div>Hi Eliot,<br>
I guess you are adressing case of SmallInteger, otherwise I would understand<br>
optimize as using some MMX 64 or 128 bits arithmetic (like PSRLLQ).<br>
If relevant, check my trivial optimizations for large ints at<br>
<a href="http://bugs.squeak.org/view.php?id=7109" target="_blank">http://bugs.squeak.org/view.php?id=7109</a></blockquote><div><br></div><div><br></div><div>Hi Nicholas,</div><div><br></div><div> yes I'm doing SmallInteger and also trying to keep the JIT very simple initially so no MMX registers or instructions in the stage one JIT until I do floating-point. I'll take a look at these. Thanks.</div>
<blockquote class="gmail_quote" style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0.8ex; border-left-width: 1px; border-left-color: rgb(204, 204, 204); border-left-style: solid; padding-left: 1ex; ">
</blockquote><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;"><a href="http://bugs.squeak.org/view.php?id=7109" target="_blank"></a><br>
<font color="#888888"><br>
Nicolas<br>
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