From 5a5ac81fe9916f532f6e05e730497d4970eeb910 Mon Sep 17 00:00:00 2001 From: lkcl Date: Tue, 19 Jan 2021 14:51:59 +0000 Subject: [PATCH] --- openpower/sv/remap.mdwn | 2 ++ 1 file changed, 2 insertions(+) diff --git a/openpower/sv/remap.mdwn b/openpower/sv/remap.mdwn index 483d24478..6ded7ef6d 100644 --- a/openpower/sv/remap.mdwn +++ b/openpower/sv/remap.mdwn @@ -229,3 +229,5 @@ void gmix_column(unsigned char *r) { With the assumption made by the above code that the column bytes have already been turned around (vertical rather than horizontal) SUBVL.REMAP may transparently fill that role, in-place, without a complex byte-level mv operation. The application of the swizzles allows the remapped vec4 a, b and r variables to perform four straight linear 32 bit XOR operations where a scalar processor would be required to perform 16 byte-level individual operations. Given wide enough SIMD backends in hardware these 3 bit XORs may be done as single-cycle operations across the entire 128 bit Rijndael Matrix. + +The other alternative is to simply perform the actual 4x4 GF(256) Matrix Multiply using the MDS Matrix. -- 2.30.2