use bit_length rather than log2_int function in mask.py

diff --git a/src/nmutil/mask.py b/src/nmutil/mask.py
index 4a04862afe99dd7c1dcaf225dfd1c89df5935ff3..dc2f05d59f4e460b2692798cc749142b2abb933e 100644 (file)
--- a/src/nmutil/mask.py
+++ b/src/nmutil/mask.py
@@ -17,14 +17,14 @@ def masked(m_out, m_in, mask):
 class Mask(Elaboratable):
     def __init__(self, sz):
         self.sz = sz
-        self.shift = Signal(log2_int(sz, False)+1)
+        self.shift = Signal(sz.bit_length()+1)
         self.mask = Signal(sz)
 
     def elaborate(self, platform):
         m = Module()
 
         for i in range(self.sz):
-            with m.If(self.shift > i):
+            with m.If(i < self.shift):
                 m.d.comb += self.mask[i].eq(1)
 
         return m