From mboxrd@z Thu Jan  1 00:00:00 1970
From: Paolo Bonzini <pbonzini@redhat.com>
Subject: Re: [Qemu-devel] [PATCH for-1.7] target-i386: Fix build by providing
 stub kvm_arch_get_supported_cpuid()
Date: Tue, 12 Nov 2013 23:53:47 +0100
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Cc: Anthony Liguori <anthony@codemonkey.ws>,
	Peter Maydell <peter.maydell@linaro.org>,
	kvm-devel <kvm@vger.kernel.org>, Gleb Natapov <gleb@redhat.com>,
	Patch Tracking <patches@linaro.org>,
	QEMU Developers <qemu-devel@nongnu.org>,
	Andreas Tobler <andreast@freebsd.org>,
	Anthony Liguori <aliguori@amazon.com>
To: Richard Henderson <rth@twiddle.net>
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Il 12/11/2013 19:54, Richard Henderson ha scritto:
> For what it's worth, I think BOTH of the patches that have been posted
> should be applied.  That is, the patch that does (X || 1) -> (1 || X),
> and the patch that adds the stub.
> 
> Frankly I'd have thought this was obvious

It's not that obvious to me.

If you add the stub, the patch that reorders operands is not necessary.
 If you reorder operands, the stub is not necessary.

The patch that does (X || 1) -> (1 || X) is unnecessary as a
microoptimization, since this code basically runs once at startup.  The
code is also a little bit less clear with the reordered operands, but
perhaps that's just me because I wrote the code that way.  (Splitting
the if in two would also make sense, and would not affect clarity).

Why should both be applied?

Paolo