This is the mail archive of the libc-alpha@sourceware.org mailing list for the glibc 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: [RFC][PATCH 0/2] Make sparcv8 work again on cas enabled hardware

On 11/03/2016 11:22 AM, David Miller wrote:

From: Torvald Riegel <triegel@redhat.com>
Date: Thu, 03 Nov 2016 16:39:21 +0100


Is there any difference between the additional CAS on a v8 and the CAS
on a v9?  If there should be none (eg, same instruciton encoding etc.),
we wouldn't need a runtime check for this, would we?


A quick look at binutils shows that the encoding appears to be the same.


Yes and no.  The instruction format is the same, but the ASI used is different.
The CAS for leon userspace uses ASI_USERDATA (0x0A), not the v9 ASI_P (0x80). It's a really annoying difference that I wish the cpu designers hadn't made. 


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