From: lkcl <lkcl@web>
Date: Fri, 26 Feb 2021 08:04:05 +0000 (+0000)
Subject: (no commit message)
X-Git-Tag: convert-csv-opcode-to-binary~124
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=393910c2da6b48f2e28c49c5f28916213d92dd59;p=libreriscv.git

---

diff --git a/openpower/isa.mdwn b/openpower/isa.mdwn
index 4a039a2b3..9b8ce96fd 100644
--- a/openpower/isa.mdwn
+++ b/openpower/isa.mdwn
@@ -39,10 +39,15 @@ results in the parser seeing the following python code:
 
 To support this python-like syntax some of the pseudocode after extraction from the PDF had to be cleaned up and proper indentation added.
 
-Also worth noting as used in the above example: the following operators are used:
+Also worth noting as used in the above example: the following operators are used (see section 1.3 "Notation" of v3.0B PDF):
 
 * `<-` assignment, instead of "=" as in python
 * `=` equals comparator, instead of "==" as in python
 * `||` concatenate, done bitwise, in MSB0 order.
 * `>u' for unsigned greater (">" is signed)
 * `<u' for unsigned lessthan ("<" is signed)
+* X superscript n subscript is instead expressed `[X]*n`
+* X subscript n or n:m is expressed as `X[n:m]`
+
+The reason for the addition of the unsigned comparator operators is because numbers in the pseudocode are bitpatterns, not assigned a type or a sign as would normally be done in a standard programming language
+