From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Mon, 7 Mar 2022 22:37:11 +0000 (+0000)
Subject: use full polynomial in gf_invert()
X-Git-Tag: opf_rfc_ls005_v1~3123
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=15b1d20fce21a9f4488dce744b4a68a13615a826;p=libreriscv.git

use full polynomial in gf_invert()
---

diff --git a/openpower/sv/gf2.py b/openpower/sv/gf2.py
index 6798cd1f6..420034d46 100644
--- a/openpower/sv/gf2.py
+++ b/openpower/sv/gf2.py
@@ -76,7 +76,7 @@ def xgcd(a, b):
 # https://ftp.libre-soc.org/ARITH18_Kobayashi.pdf
 def gf_invert(a) :
 
-    s = polyred
+    s = getGF2() # get the full polynomial (including the MSB)
     r = a
     v = 0
     u = 1
@@ -140,5 +140,5 @@ if __name__ == "__main__":
 
     y1 = gf_invert(y)
     z1 = multGF2(z, y1)
-    print(hex(polyred), hex(y1), hex(z1))
+    print(hex(polyred), hex(y1), hex(x), "==", hex(z1))