From adabaaa74c78cc282c2c0cfd5da75b63cc526017 Mon Sep 17 00:00:00 2001 From: lkcl Date: Tue, 19 Jan 2021 13:44:44 +0000 Subject: [PATCH] --- openpower/sv/remap.mdwn | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/openpower/sv/remap.mdwn b/openpower/sv/remap.mdwn index 5a8c537d4..2ac51201c 100644 --- a/openpower/sv/remap.mdwn +++ b/openpower/sv/remap.mdwn @@ -178,5 +178,13 @@ The reason for allowing SUBVL Remaps is that some regular patterns using Swizzle An example where SUBVL Remap is appropriate is the Rijndael MixColumns stage: - + + +A 2D REMAP allows: + +* the column bytes (as a vec4) to be iterated over as an inner loop. +* the columns themselves to be iterated as an outer loop +* a 32 bit `GF(256)` multiply on the vec4 to be performed. + +This entirely in-place without special 128-bit opcodes. -- 2.30.2