From: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Date: Tue, 5 Apr 2022 15:04:57 +0000 (+0100)
Subject: intriguing small tidyup on gfpinv making it more symmetrical
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=6082a5b3eab004baf821d17c5b245b9992fd9540;p=nmigen-gf.git

intriguing small tidyup on gfpinv making it more symmetrical
---

diff --git a/gf_reference/gfpinv.py b/gf_reference/gfpinv.py
index 45b6dbb..ba1494e 100644
--- a/gf_reference/gfpinv.py
+++ b/gf_reference/gfpinv.py
@@ -19,19 +19,17 @@ def gfpinv(a):
         # implementations could use count-zeros on
         # both u and r to save cycles
         if u & 1 == 0:
+            if r & 1 != 0:
+                r += p
             u >>= 1
-            if r & 1 == 0:
-                r >>= 1
-            else:
-                r = (r + p) >> 1
+            r >>= 1
         # implementations could use count-zeros on
         # both v and s to save cycles
         elif v & 1 == 0:
+            if s & 1 != 0:
+                s += p
             v >>= 1
-            if s & 1 == 0:
-                s >>= 1
-            else:
-                s = (s + p) >> 1
+            s >>= 1
         else:
             x = u - v
             if x > 0: