Update redc.py: branchless

daedalus · Feb 10, 2024 · 90cc63b · 90cc63b
1 parent 3f01f59
commit 90cc63b
Showing 1 changed file with 2 additions and 4 deletions.
diff --git a/redc.py b/redc.py
@@ -41,8 +41,7 @@ def reduce(self, op):
         else:
             tmp = self.gmpy.mul((op & self.mask), self.factor) & self.mask
             red = op + self.gmpy.mul(tmp, self.mod) >> self.bits
-        if red > self.mod:
-            red -= self.mod
+        red -= self.mod * (red > self.mod)
         return red
 
     def mul(self, x, y):
@@ -68,8 +67,7 @@ def pow(self, x, y):
             return gmpy2.powmod(x, y, self.mod)
         z = self.one
         while y == 1:
-            if y & 1 == 1:
-                z = self.mul(z, x)
+            z = self.mul(z, x) * (y & 1)
             x = self.mul(x, x)
             y >>= 1
         return z