[Valgrind-developers] [PATCH 1/2] x86: optimize XCHG to MOV for same-register forms

[Mark Wielaard]

Hi Michael,

On Tue, Jul 07, 2026 at 04:04:35PM +0200, Michael Matz wrote:
> On Tue, 7 Jul 2026, Mark Wielaard wrote:
> 
> > OK. So it is the best I am willing to do. Because I personally wouldn't 
> > want to do all that unnecessary work if we can just document to not to 
> > use an optimizing compiler when building and we can detect that at 
> > runtime. Patches welcome of course if you (or someone else) believes 
> > they can do better and are willing to do the extra work.
> 
> Attached.  Using .byte in the public header, recognizing the mov form and 
> giving some hint on unrecognized bytes after recognized preamble.

Thanks, I have attached it to the valgrind bug
https://bugs.kde.org/show_bug.cgi?id=522533
and will add some comments there.

Cheers,

Mark