[x265] [PATCH] alignment DCT8's stack to 64-bytes to avoid crash and improvement cache performance

[Steve Borho]

On Tue, Apr 15, 2014 at 9:49 PM, Min Chen <chenm003 at 163.com> wrote:
> # HG changeset patch
> # User Min Chen <chenm003 at 163.com>
> # Date 1397616580 -28800
> # Node ID 1a8b54ce0dfa8eba524c4cadc81939710054ae44
> # Parent  1cf67a7b362d24d292d7cca574cbcfe88a8eb1cb
> alignment DCT8's stack to 64-bytes to avoid crash and improvement cache performance

queued, thanks!

for future reference, you want to use "align" the verb here, instead
of "alignment" the noun.
Similarly, "improve" rather than "improvement".

>
> diff -r 1cf67a7b362d -r 1a8b54ce0dfa source/common/x86/dct8.asm
> --- a/source/common/x86/dct8.asm        Mon Apr 14 21:26:37 2014 -0500
> +++ b/source/common/x86/dct8.asm        Wed Apr 16 10:49:40 2014 +0800
> @@ -834,8 +834,14 @@
>
>      ret
>
> -cglobal idct8, 3,7,8,0-16*mmsize
> +cglobal idct8, 3,7,8 ;,0-16*mmsize
> +    ; alignment stack to 64-bytes
>      mov         r5, rsp
> +    sub         rsp, 16*mmsize + gprsize
> +    and         rsp, ~(64-1)
> +    mov         [rsp + 16*mmsize], r5
> +    mov         r5, rsp
> +
>      lea         r4, [tab_idct8_3]
>      lea         r6, [tab_dct4]
>
> @@ -866,4 +872,7 @@
>
>      call        patial_butterfly_inverse_internal_pass2
>
> +    ; restore origin stack pointer
> +    mov         rsp, [rsp + 16*mmsize]
> +
>      RET
>
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-- 
Steve Borho