This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [Patch, PPC] extend TARGET_NO_LWSYNC to cover 440 and 603 processors.


On 21 Jul 2012, at 18:04, Iain Sandoe wrote:
> On 21 Jul 2012, at 17:43, Andrew Pinski wrote:
>> On Sat, Jul 21, 2012 at 9:12 AM, Iain Sandoe <iain@codesourcery.com> wrote:

>>> The following patch was been in use internally, for some time, to handle two further cases where the processor does not have lwsync.  Verified on a cross from i686-linux-gnu to powerpc-linux-gnu.

>> This was only done for e500 and not other proessors as the e500 was
>> not fully compatible even with the older spec.  In that lwsync would
>> cause an illegal instruction exception.  This is NOT the case for 603
>> and the 440 so I don't think this patch should applied.
> 
> The original report, for which our change was made, was of an instruction exception caused by lwsync on 440.
> I'm not personally familiar with that processor, I'll try and get access to a board/confirm in due course.

To follow up on this thread and ref[1].
This is not repeatable on a 440EP.  It was reported against a device using a 440H6 core.
We have not been able to locate an erratum, so we're going to drop the patch unless/until there is a specific reproducible report of failure.
thanks
Iain

[1] http://gcc.gnu.org/ml/gcc-patches/2012-03/msg01817.html


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]