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Subject: Re: [PATCH -v2] x86/hweight: Get rid of the special calling
 convention
To: Borislav Petkov <bp@suse.de>
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Cc: Peter Zijlstra <peterz@infradead.org>, x86-ml <x86@kernel.org>,
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        Ingo Molnar <mingo@redhat.com>,
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From: "H. Peter Anvin" <hpa@zytor.com>
Message-ID: <ca79a89a-7240-8572-1688-ec5506c12665@zytor.com>
Date: Tue, 10 May 2016 15:30:48 -0700
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On 05/10/16 12:10, Borislav Petkov wrote:
> On Tue, May 10, 2016 at 12:03:48PM -0700, H. Peter Anvin wrote:
>> Also, to be fair... if the problem is with these being in C then we
>> could just do it in assembly easily enough.
> 
> I thought about converting the __sw_hweight* variants to asm but
> __sw_hweight32, for example, is 55 bytes here and that's a lot.
> 
> Or do you have a better idea?
> 
> peterz's sounds ok to me: we call a thunk which then calls __sw_hweight*
> after having saved regs properly - problem solved.
> 

I didn't mean inline assembly.

	-hpa