RE: [PATCH v4 2/2] LAM: Enable tagged pointer support for watchpoints.

["Schimpe, Christina" <christina.schimpe@intel.com>]

> > From: "Schimpe, Christina" <christina.schimpe@intel.com>
> > CC: "gdb-patches@sourceware.org" <gdb-patches@sourceware.org>,
> > "Willgerodt,  Felix" <felix.willgerodt@intel.com>, "luis.machado@arm.com"
> > 	<luis.machado@arm.com>
> > Date: Thu, 4 Jul 2024 13:15:20 +0000
> >
> > So to answer your question properly: No, we don't explain the term "
> tagged data pointers" anywhere.
> > But we write for instance in the commit message "tagged pointers used
> > for data accesses", which is understandable I think.
> 
> Well, I'm sorry to say that it doesn't explain this enough for me.
> I'm quite a heavy user of GDB, but I have no idea what is a tagged pointer for
> data access.  Do we have in the manual anything related to such pointers,
> even if we use different words to talk about them?  If so, could you point me
> to those descriptions in the manual?  Maybe if I read what we say there, I
> could suggest wording for NEWS that will be consistent with our terminology
> in the manual.
> 
> Thanks.

Hi Eli, 

Sorry for the confusion here.
You are right, the term "tagged pointer" is not explained anywhere in the manual. 
Also I couldn't find a section that describes them but uses a different wording.

I think the first time we use this term in GDB is with commit
"Clear non-significant bits of address on memory access".  
The terms tagged address and tagged pointer are used.

A very similar commit for setting a  watchpoint on a tagged address but for AArch64 is:
"Clear non-significant bits of address in watchpoint"

For both commits I couldn't find any documentation/NEWS part.

I will try to come up with a section on tagged addresses/pointers in the manual.

Thanks,
Christina

Intel Deutschland GmbH
Registered Address: Am Campeon 10, 85579 Neubiberg, Germany
Tel: +49 89 99 8853-0, www.intel.de
Managing Directors: Sean Fennelly, Jeffrey Schneiderman, Tiffany Doon Silva
Chairperson of the Supervisory Board: Nicole Lau
Registered Office: Munich
Commercial Register: Amtsgericht Muenchen HRB 186928