From: lkcl <lkcl@web>
Date: Fri, 9 Jun 2023 11:13:15 +0000 (+0100)
Subject: (no commit message)
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=57398591b40ccf7cf3d9995b2c199f541f263df7;p=libreriscv.git

---

diff --git a/openpower/sv/po9_encoding/discussion.mdwn b/openpower/sv/po9_encoding/discussion.mdwn
index d85bdebc0..db1db31a3 100644
--- a/openpower/sv/po9_encoding/discussion.mdwn
+++ b/openpower/sv/po9_encoding/discussion.mdwn
@@ -1,7 +1,20 @@
 [[!toc]]
 
+# introduction
+
+the purpose of this page is to create and evaluate alternative
+encoding schemes that allow for a hybrid mixture of
+(ultra-precious) 32-bit and 64-bit (actually `x86 REP`-like
+prefixed) instructions.
+
+a specific view to attaining high-speed massive-wide multi-issue decode
+is a high priority.  therefore especially length-detection must be kept
+brutally simple.
+
 # alternative 32-64 encoding (1)
 
+**superseded**
+
 conflict to resolve: EXT90x and EXT232. they are indistinguishable.
 
 ```
@@ -51,6 +64,8 @@ Instruction allocation restrictions:
 
 # alternative 32-64 encoding (2)
 
+**superseded**
+
 requires reducing SVP64Single to 23 bits. luckily there are 2 spare
 
 the complexity of attempting to fit 32-bit instructions into
@@ -93,7 +108,8 @@ Length detection:
 
 # alternative 32-64 encoding (3)
 
-TODO 
+**current**
+
 aim of this idea is to attempt simplification of area identification
 and length.  the 55-bit area is eliminated and may only be reintroduced
 by sacrificing parts of EXT200-231, bear in mind that EXT209 is already