lkml.org 
[lkml]   [2004]   [Feb]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Intel vs AMD64


Nakajima, Jun wrote:
> Thanks for the clarification.
>
> Yes, "implementation specific" is one of the differences between IA-32e
> and AMD64, i.e. that behavior is architecturally defined on AMD64, but
> on IA-32e (as I posted):
> Near branch with 66H prefix:
> As documented in PRM the behavior is implementation specific and
> should
> avoid using 66H prefix on near branches.


In other words, Intel's implementation deviates from the architecture as
defined by AMD. So it's not 100% compatible. I just want this point to
be clear.


If these sorts of branches are common enough (and I suspect they are),
then this sort of deviation could have a notable code-size (and L1)
impact on code which is compiled to be compatible with both implementations.

Why did Intel decide to do that?

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 14:01    [from the cache]
©2003-2011 Jasper Spaans