From: lkcl <lkcl@web>
Date: Tue, 19 Jan 2021 14:51:59 +0000 (+0000)
Subject: (no commit message)
X-Git-Tag: convert-csv-opcode-to-binary~398
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=5a5ac81fe9916f532f6e05e730497d4970eeb910;p=libreriscv.git

---

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.