From: lkcl <lkcl@web>
Date: Sat, 11 Jun 2022 15:09:00 +0000 (+0100)
Subject: (no commit message)
X-Git-Tag: opf_rfc_ls005_v1~1850
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=7a257aa08cf07fe98486297c09ab27a3685d79d5;p=libreriscv.git

---

diff --git a/openpower/sv/mv.swizzle.mdwn b/openpower/sv/mv.swizzle.mdwn
index f417589a0..2aaa8504a 100644
--- a/openpower/sv/mv.swizzle.mdwn
+++ b/openpower/sv/mv.swizzle.mdwn
@@ -5,8 +5,15 @@
 Links
 
 * <https://bugs.libre-soc.org/show_bug.cgi?id=139>
-
-the encoding embeds predication into the swizzle as well as constants 1/1.0 and 0/0.0
+* <https://lists.libre-soc.org/pipermail/libre-soc-dev/2022-June/004913.html>
+
+Swizzle is usually done on a per-operand basis in 3D GPU ISAs, making
+for extremely long instructions (64 bits or greater).
+Their value lies in the high occurrence of Swizzle
+in 3D Shader Binaries (over 10% of all instructions).
+A compromise is to provide a Swizzle "Move".
+The encoding for this instruction embeds static predication into the
+swizzle as well as constants 1/1.0 and 0/0.0
 
 **As a Scalar instruction**