RE: [Xen-devel] [PATCH 3/3] Add shadow VRAM

Dugger, Donald D
Wed, 15 Mar 2006 23:28:01 -0000

Kier-

My concern is the flag `-msse2'' that has to be added to the compile
flags.  I''m not an expert on GCC but I didn''t want to create a
situation
where someone using an older compiler wasn''t able to compile.
I''d only
want to remove the compile time checks if we were sure that all build
machines use a compiler with sse2 support.

A secondary concern was that I wanted to accommodate someone who wanted
to disable using the sse2 instructions even if running on a machine with
sse2 support.  Probably not a likely occurrence but I like to cover all
eventualities.

If we don''t think this is a necessary feature it''s easy enough
to remove
the build time check.

--
Don Dugger
"Censeo Toto nos in Kansa esse decisse." - D. Gale
Donald.D.Dugger@intel.com
Ph: (303)440-1368

>-----Original Message-----
>From: Keir Fraser [mailto:Keir.Fraser@cl.cam.ac.uk]
>Sent: Wednesday, March 15, 2006 4:14 PM
>To: Dugger, Donald D
>Cc: xen-devel@lists.xensource.com
>Subject: Re: [Xen-devel] [PATCH 3/3] Add shadow VRAM
>
>
>On 15 Mar 2006, at 23:13, Dugger, Donald D wrote:
>
>> Nice try but I thought of that :-)  The code checks at run time also,
>> for just the reason you state.  Also, I did measure and the runtime
>> check adds no measurable overhead.
>
>Can you get rid of the compile-time checks from your patch then, since
>they''re redundant.
>
>I think that, although we''d like to track qemu''s source
files, we''ll
>avoid their build system as much as possible. So I''d
>definitely like to
>avoid adding stuff into their configuration scripts.