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Subject: Re: [BUG] [5.15] Compilation error in arch/x86/kvm/mmu/spte.h with
 clang-14
From:   Christophe de Dinechin <cdupontd@redhat.com>
In-Reply-To: <fb1da4d3-9e3e-4604-2f30-30292f9d13aa@redhat.com>
Date:   Fri, 15 Oct 2021 11:17:22 +0200
Cc:     Nick Desaulniers <ndesaulniers@google.com>,
        Sean Christopherson <seanjc@google.com>,
        Nathan Chancellor <nathan@kernel.org>,
        Jim Mattson <jmattson@google.com>, torvic9@mailbox.org,
        "vkuznets@redhat.com" <vkuznets@redhat.com>,
        "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "tglx@linutronix.de" <tglx@linutronix.de>,
        "bp@alien8.de" <bp@alien8.de>
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To:     Paolo Bonzini <pbonzini@redhat.com>
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> On 14 Oct 2021, at 22:50, Paolo Bonzini <pbonzini@redhat.com> wrote:
>=20
> On 14/10/21 21:06, Nick Desaulniers wrote:
>>> If we want to fix this, my vote is for casting to an int and =
updating the comment
>> At the least, I think bitwise operations should only be performed on
>> unsigned types.
>=20
> This is not a bitwise operation, it's a non-short-circuiting boolean =
operation.  I'll apply Jim's suggestion.

What about making it an inline function, which would require evaluation =
of arguments:

	static __always_inline bool BITWISE_BOOLEAN_OR(bool a, bool b)
	{
	    return a || b; // Safe here, because arguments have been =
evaluated
	}

Suggesting that because I'm always nervous about casts in macros hiding =
something that the type  system would otherwise catch.


Christophe
>=20
> Paolo
>=20