[Openmcl-devel] Windows versions of CCL available for smoke-testing

Gary Byers gb at clozure.com
Thu Oct 9 10:12:07 PDT 2008

This is all potentially confusing.  Wikipedia provides good overviews
of what the terms SSE2 and SSE3 mean in this context:


SSE2 was an extension that provides vector floating-point registers
(that can also be used as scalar floating-point registers.)  It was
introduced in 2001, and most CPUs sold since then provide it.  (One
notable exception is the AMD Geode, which is used in the the laptops
made by the One Laptop Per Child project.)

SSE3 adds a relatively small set of instructions to SSE2 (most of
which operate on these vector registers.)

The kernel checks for the presence of SSE2 on startup and says something
like "CPU doesn't support required features" and exits if it's not present.
Nothing in the lisp uses SSE3 or later.

There's a little (free) Windows program called "CPU-Z" that'll tell you way
more than you want to know about the features of the installed CPU.


On a Linux system, you can do:

shell> cat /proc/cpuinfo

to see the same sort of info.  (Darwin assumes at least SSE3; there are
probably ways to see CPU info via 'sysctl' on FreeBSD or Solaris, but
I don't remember what they are, offhand.)

We've spoken a bit about the idea of emulating the SSE2 features that
we use or of otherwise trying to run on SSE2-less hardware.  Right now,
we're just trying to find out if this runs at all ...

On Thu, 9 Oct 2008, David Brown wrote:

> On Wed, Oct 08, 2008 at 08:28:25PM -0600, Gary Byers wrote:
>> 32- and 64-bit versions of Clozure CL for Windows are now available in svn:
> General question about the 32-bit x86 ports.  A while back there was
> mention of needing SSE3.  Is this still a requirement for these ports?
> Thanks,
> David

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