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From:   Nick Desaulniers <ndesaulniers@google.com>
Date:   Tue, 1 Feb 2022 13:15:57 -0800
Message-ID: <CAKwvOdk3rtHCDfW-kCmmQ=UueeXpVVBnG1XGwdoiWWHZgmt5yQ@mail.gmail.com>
Subject: Re: [PATCH 1/5] Kconfig: Add option for asm goto w/ tied outputs to
 workaround clang-13 bug
To:     Sean Christopherson <seanjc@google.com>
Cc:     Paolo Bonzini <pbonzini@redhat.com>,
        Nathan Chancellor <nathan@kernel.org>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Jim Mattson <jmattson@google.com>,
        Joerg Roedel <joro@8bytes.org>, kvm@vger.kernel.org,
        llvm@lists.linux.dev, linux-kernel@vger.kernel.org,
        Peter Zijlstra <peterz@infradead.org>,
        syzbot+6cde2282daa792c49ab8@syzkaller.appspotmail.com
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On Tue, Feb 1, 2022 at 12:56 PM Sean Christopherson <seanjc@google.com> wrote:
>
> On Tue, Feb 01, 2022, Nick Desaulniers wrote:
> > Note: gcc-10 had a bug with the symbolic references to labels when
> > using tied constraints.
> > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98096
> >
> > Both compilers had bugs here, and it may be worth mentioning that in
> > the commit message.
>
> Is this wording accurate?
>
>   gcc also had a similar bug[3], fixed in gcc-11, where gcc failed to
>   account for its behavior of assigning two numbers to tied outputs (one
>   for input, one for output) when evaluating symbolic references.

SGTM
-- 
Thanks,
~Nick Desaulniers