intriguing small tidyup on gfpinv making it more symmetrical

diff --git a/gf_reference/gfpinv.py b/gf_reference/gfpinv.py
index 45b6dbbdd4cb19bdbfa0538fb9dfcb79981655fe..ba1494e28977ce4b66290d040a0028d7ae1d2bf2 100644 (file)
--- 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: