[prev in list] [next in list] [prev in thread] [next in thread] 

List:       linux-kernel
Subject:    Re: [PATCH v4 04/17] x86/acrn: Introduce hypercall interfaces
From:       Segher Boessenkool <segher () kernel ! crashing ! org>
Date:       2020-09-30 23:58:48
Message-ID: 20200930235848.GD28786 () gate ! crashing ! org
[Download RAW message or body]

On Wed, Sep 30, 2020 at 09:42:40PM +0200, Peter Zijlstra wrote:
> > Looks like yes. You can even check different GCC versions via the
> > dropdown in the top right.
> 
> That only tells me it compiles it, not if that (IMO) weird construct is
> actually guaranteed to work as expected.
> 
> I'd almost dive into the GCC archives to read the back-story to this
> 'feature', it just seems to weird to me. A well, for another day that.

It was documented in 1996 (<https://gcc.gnu.org/g:c1f7febfcb10>), the
feature is older than that though.

In 2004 (in <https://gcc.gnu.org/g:805c33df1366>) the documentation for
this was made more explicit (it has been rewritten since, but it still
says the same thing).


Segher
[prev in list] [next in list] [prev in thread] [next in thread]