[FFmpeg-devel] libavutil: optimize camellia cipher

[Michael Niedermayer]

On Tue, Feb 10, 2015 at 12:44:23AM +0530, supraja reddy wrote:
> Hello,
> 
> I have attached a patch to optimize the camellia block cipher.
> I ran crypto_bench on the optimized version. Here are the results of
> runtime using crypto_bench.
> 
> Before the changes :
> lavu       CAMELLIA     size: 1048576  runs:   1024  time:   32.541 +- 0.044
> 
> After the changes:
> lavu       CAMELLIA     size: 1048576  runs:   1024  time:   24.589 +- 0.066
> 
> I ran this on a Linux x86_64 OS with Intel Core i5-3210M CPU.
> 
> Please let me know if there are any changes you would like.
> 
> 
> Thanks,
> 
> Supraja

>  camellia.c |   37 +++++++++++++++++++++++++++----------
>  1 file changed, 27 insertions(+), 10 deletions(-)
> 0aecabcca7c8404e628afc26ff632314d01f2c1c  camopt1.patch
> From 9079c80bd5caa122ea1261b47e1fcb0e7d554af5 Mon Sep 17 00:00:00 2001
> From: Supraja Meedinti <supraja0493 at gmail.com>
> Date: Tue, 10 Feb 2015 00:16:55 +0530
> Subject: [PATCH] libavutil: optimize camellia cipher

applied

[...]
> @@ -140,17 +142,11 @@ static void LR128(uint64_t d[2], const uint64_t K[2], int x)
>  
>  static uint64_t F(uint64_t F_IN, uint64_t KE)
>  {
> -    uint32_t Zl, Zr;
> +    uint8_t y[8];
>      KE ^= F_IN;
[...]
> +    AV_WB64(y,KE);
> +    KE=SP[0][y[0]]^SP[1][y[1]]^SP[2][y[2]]^SP[3][y[3]]^SP[4][y[4]]^SP[5][y[5]]^SP[6][y[6]]^SP[7][y[7]];
> +    return KE;

have you tried it without the y[] array ?
storing and loading from memory may (or may not) be slower

thanks

[...]

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