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In-Reply-To: <7a756b816161007903ca8b28aec662de27135c55.1527161282.git.christophe.leroy@c-s.fr>
To:     Christophe Leroy <christophe.leroy@c-s.fr>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>, segher@kernel.crashing.org
From:   Michael Ellerman <patch-notifications@ellerman.id.au>
Cc:     linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [v4] powerpc: Implement csum_ipv6_magic in assembly
Message-Id: <40zxgH0VQMz9s7P@ozlabs.org>
Date:   Tue,  5 Jun 2018 00:11:04 +1000 (AEST)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Thu, 2018-05-24 at 11:33:18 UTC, Christophe Leroy wrote:
> The generic csum_ipv6_magic() generates a pretty bad result
> 
> 00000000 <csum_ipv6_magic>: (PPC32)
>    0:	81 23 00 00 	lwz     r9,0(r3)
>    4:	81 03 00 04 	lwz     r8,4(r3)
>    8:	7c e7 4a 14 	add     r7,r7,r9
>    c:	7d 29 38 10 	subfc   r9,r9,r7
>   10:	7d 4a 51 10 	subfe   r10,r10,r10
>   14:	7d 27 42 14 	add     r9,r7,r8
>   18:	7d 2a 48 50 	subf    r9,r10,r9
>   1c:	80 e3 00 08 	lwz     r7,8(r3)
>   20:	7d 08 48 10 	subfc   r8,r8,r9
>   24:	7d 4a 51 10 	subfe   r10,r10,r10
>   28:	7d 29 3a 14 	add     r9,r9,r7
>   2c:	81 03 00 0c 	lwz     r8,12(r3)
>   30:	7d 2a 48 50 	subf    r9,r10,r9
>   34:	7c e7 48 10 	subfc   r7,r7,r9
>   38:	7d 4a 51 10 	subfe   r10,r10,r10
>   3c:	7d 29 42 14 	add     r9,r9,r8
>   40:	7d 2a 48 50 	subf    r9,r10,r9
>   44:	80 e4 00 00 	lwz     r7,0(r4)
>   48:	7d 08 48 10 	subfc   r8,r8,r9
>   4c:	7d 4a 51 10 	subfe   r10,r10,r10
>   50:	7d 29 3a 14 	add     r9,r9,r7
>   54:	7d 2a 48 50 	subf    r9,r10,r9
>   58:	81 04 00 04 	lwz     r8,4(r4)
>   5c:	7c e7 48 10 	subfc   r7,r7,r9
>   60:	7d 4a 51 10 	subfe   r10,r10,r10
>   64:	7d 29 42 14 	add     r9,r9,r8
>   68:	7d 2a 48 50 	subf    r9,r10,r9
>   6c:	80 e4 00 08 	lwz     r7,8(r4)
>   70:	7d 08 48 10 	subfc   r8,r8,r9
>   74:	7d 4a 51 10 	subfe   r10,r10,r10
>   78:	7d 29 3a 14 	add     r9,r9,r7
>   7c:	7d 2a 48 50 	subf    r9,r10,r9
>   80:	81 04 00 0c 	lwz     r8,12(r4)
>   84:	7c e7 48 10 	subfc   r7,r7,r9
>   88:	7d 4a 51 10 	subfe   r10,r10,r10
>   8c:	7d 29 42 14 	add     r9,r9,r8
>   90:	7d 2a 48 50 	subf    r9,r10,r9
>   94:	7d 08 48 10 	subfc   r8,r8,r9
>   98:	7d 4a 51 10 	subfe   r10,r10,r10
>   9c:	7d 29 2a 14 	add     r9,r9,r5
>   a0:	7d 2a 48 50 	subf    r9,r10,r9
>   a4:	7c a5 48 10 	subfc   r5,r5,r9
>   a8:	7c 63 19 10 	subfe   r3,r3,r3
>   ac:	7d 29 32 14 	add     r9,r9,r6
>   b0:	7d 23 48 50 	subf    r9,r3,r9
>   b4:	7c c6 48 10 	subfc   r6,r6,r9
>   b8:	7c 63 19 10 	subfe   r3,r3,r3
>   bc:	7c 63 48 50 	subf    r3,r3,r9
>   c0:	54 6a 80 3e 	rotlwi  r10,r3,16
>   c4:	7c 63 52 14 	add     r3,r3,r10
>   c8:	7c 63 18 f8 	not     r3,r3
>   cc:	54 63 84 3e 	rlwinm  r3,r3,16,16,31
>   d0:	4e 80 00 20 	blr
> 
> 0000000000000000 <.csum_ipv6_magic>: (PPC64)
>    0:	81 23 00 00 	lwz     r9,0(r3)
>    4:	80 03 00 04 	lwz     r0,4(r3)
>    8:	81 63 00 08 	lwz     r11,8(r3)
>    c:	7c e7 4a 14 	add     r7,r7,r9
>   10:	7f 89 38 40 	cmplw   cr7,r9,r7
>   14:	7d 47 02 14 	add     r10,r7,r0
>   18:	7d 30 10 26 	mfocrf  r9,1
>   1c:	55 29 f7 fe 	rlwinm  r9,r9,30,31,31
>   20:	7d 4a 4a 14 	add     r10,r10,r9
>   24:	7f 80 50 40 	cmplw   cr7,r0,r10
>   28:	7d 2a 5a 14 	add     r9,r10,r11
>   2c:	80 03 00 0c 	lwz     r0,12(r3)
>   30:	81 44 00 00 	lwz     r10,0(r4)
>   34:	7d 10 10 26 	mfocrf  r8,1
>   38:	55 08 f7 fe 	rlwinm  r8,r8,30,31,31
>   3c:	7d 29 42 14 	add     r9,r9,r8
>   40:	81 04 00 04 	lwz     r8,4(r4)
>   44:	7f 8b 48 40 	cmplw   cr7,r11,r9
>   48:	7d 29 02 14 	add     r9,r9,r0
>   4c:	7d 70 10 26 	mfocrf  r11,1
>   50:	55 6b f7 fe 	rlwinm  r11,r11,30,31,31
>   54:	7d 29 5a 14 	add     r9,r9,r11
>   58:	7f 80 48 40 	cmplw   cr7,r0,r9
>   5c:	7d 29 52 14 	add     r9,r9,r10
>   60:	7c 10 10 26 	mfocrf  r0,1
>   64:	54 00 f7 fe 	rlwinm  r0,r0,30,31,31
>   68:	7d 69 02 14 	add     r11,r9,r0
>   6c:	7f 8a 58 40 	cmplw   cr7,r10,r11
>   70:	7c 0b 42 14 	add     r0,r11,r8
>   74:	81 44 00 08 	lwz     r10,8(r4)
>   78:	7c f0 10 26 	mfocrf  r7,1
>   7c:	54 e7 f7 fe 	rlwinm  r7,r7,30,31,31
>   80:	7c 00 3a 14 	add     r0,r0,r7
>   84:	7f 88 00 40 	cmplw   cr7,r8,r0
>   88:	7d 20 52 14 	add     r9,r0,r10
>   8c:	80 04 00 0c 	lwz     r0,12(r4)
>   90:	7d 70 10 26 	mfocrf  r11,1
>   94:	55 6b f7 fe 	rlwinm  r11,r11,30,31,31
>   98:	7d 29 5a 14 	add     r9,r9,r11
>   9c:	7f 8a 48 40 	cmplw   cr7,r10,r9
>   a0:	7d 29 02 14 	add     r9,r9,r0
>   a4:	7d 70 10 26 	mfocrf  r11,1
>   a8:	55 6b f7 fe 	rlwinm  r11,r11,30,31,31
>   ac:	7d 29 5a 14 	add     r9,r9,r11
>   b0:	7f 80 48 40 	cmplw   cr7,r0,r9
>   b4:	7d 29 2a 14 	add     r9,r9,r5
>   b8:	7c 10 10 26 	mfocrf  r0,1
>   bc:	54 00 f7 fe 	rlwinm  r0,r0,30,31,31
>   c0:	7d 29 02 14 	add     r9,r9,r0
>   c4:	7f 85 48 40 	cmplw   cr7,r5,r9
>   c8:	7c 09 32 14 	add     r0,r9,r6
>   cc:	7d 50 10 26 	mfocrf  r10,1
>   d0:	55 4a f7 fe 	rlwinm  r10,r10,30,31,31
>   d4:	7c 00 52 14 	add     r0,r0,r10
>   d8:	7f 80 30 40 	cmplw   cr7,r0,r6
>   dc:	7d 30 10 26 	mfocrf  r9,1
>   e0:	55 29 ef fe 	rlwinm  r9,r9,29,31,31
>   e4:	7c 09 02 14 	add     r0,r9,r0
>   e8:	54 03 80 3e 	rotlwi  r3,r0,16
>   ec:	7c 03 02 14 	add     r0,r3,r0
>   f0:	7c 03 00 f8 	not     r3,r0
>   f4:	78 63 84 22 	rldicl  r3,r3,48,48
>   f8:	4e 80 00 20 	blr
> 
> This patch implements it in assembly for both PPC32 and PPC64
> 
> Link: https://github.com/linuxppc/linux/issues/9
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
> Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/e9c4943a107b56696e4872cdffdba6

cheers