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Date: Wed, 11 May 2016 06:11:28 +0200
From: Borislav Petkov <bp@suse.de>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>, x86-ml <x86@kernel.org>,
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        Andy Lutomirski <luto@amacapital.net>
Subject: Re: [PATCH -v2] x86/hweight: Get rid of the special calling
 convention
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On Tue, May 10, 2016 at 03:30:48PM -0700, H. Peter Anvin wrote:
> I didn't mean inline assembly.

How does that matter?

The problem is having as less insn bytes as possible and the minimal
size we can do is issuing POPCNT everywhere which is 4 or 5 bytes. The
alternatives then replace that with a CALL which is also 5 bytes.

The way I did it now, it adds 22K more to allyesconfig vmlinux due to
the static_cpu_has doubled alternatives sections and the JMPs. The
thunks will keep those 5 bytes *and* get rid of the calling convention
without the growth.

Or?

-- 
Regards/Gruss,
    Boris.

SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
--