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Date: Wed, 10 Aug 2016 10:56:05 +0200
From: Gabriel Paubert <paubert@iram.es>
To: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
 Paul Mackerras <paulus@samba.org>, Michael Ellerman <mpe@ellerman.id.au>,
 Scott Wood <oss@buserror.net>, linuxppc-dev@lists.ozlabs.org,
 linux-kernel@vger.kernel.org
Subject: Re: [PATCH] powerpc/32: Remove one insn in __bswapdi2
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On Fri, Aug 05, 2016 at 01:28:02PM +0200, Christophe Leroy wrote:
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
> ---
>  arch/powerpc/kernel/misc_32.S | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
> index e025230..e18055c 100644
> --- a/arch/powerpc/kernel/misc_32.S
> +++ b/arch/powerpc/kernel/misc_32.S
> @@ -578,9 +578,8 @@ _GLOBAL(__bswapdi2)
>  	rlwimi  r9,r4,24,0,7
>  	rlwimi  r10,r3,24,0,7
>  	rlwimi  r9,r4,24,16,23
> -	rlwimi  r10,r3,24,16,23
> +	rlwimi  r4,r3,24,16,23
>  	mr      r3,r9
> -	mr      r4,r10
>  	blr
>  

Hmmm, are you sure that it works? rlwimi is a bit special since the
first operand is both an input and an output of the instruction.


In other words, did you test the code?

    Gabriel