Réécriture de M_R² en Python

1 files changed, 15 insertions, 26 deletions

diff --git a/src/add_python/lilliput/multiplications.py b/src/add_python/lilliput/multiplications.py
index 8ca8c7f..edbdaf3 100644
--- a/src/add_python/lilliput/multiplications.py
+++ b/src/add_python/lilliput/multiplications.py
@@ -41,6 +41,9 @@ def _M1(xi):
 def _M2(xi):
     return (xi<<6 ^ (xi&0b11111000) ^ xi>>6) & 0xff
 
+def _M3(xi):
+    return xi & 0b00011111
+
 
 M = (
     ( _0,    _Id,     _0,     _0,  _0,  _0,  _0,  _0),
@@ -91,6 +94,17 @@ MR = (
     (_Id,  _0,  _0,     _0,     _0,  _0,     _0,  _0),
 )
 
+MR2 = (
+    ( _0,  _0, _Id,     _0,     _0,     _0,     _0,     _0),
+    ( _0,  _0,  _0,    _Id, _Sr(3),     _0,     _0,     _0),
+    ( _0,  _0,  _0,     _0,    _Id, _Sr(3),    _M3,     _0),
+    ( _0,  _0,  _0,     _0,     _0,    _Id, _Sl(3),     _0),
+    ( _0,  _0,  _0, _Sl(2),     _0,     _0,    _Id, _Sl(3)),
+    ( _0,  _0,  _0,     _0, _Sl(2),     _0,     _0,    _Id),
+    (_Id,  _0,  _0,     _0,     _0,     _0,     _0,     _0),
+    ( _0, _Id,  _0,     _0,     _0,     _0,     _0,     _0),
+)
+
 
 def _multiplication(m, reverse=True):
     def ordered(l):
@@ -107,31 +121,6 @@ def _multiplication(m, reverse=True):
     return _multiply
 
 
-def _multiply_MR2(lane):
-    multiplied_lane = [lane[(byte+2) % 8] for byte in range(0, 8)]
-
-    multiplied_lane[1] ^= ((lane[4] >> 3) & 0xff)
-    multiplied_lane[2] ^= ((lane[5] >> 3) & 0xff)
-    multiplied_lane[3] ^= ((lane[6] << 3) & 0xff)
-    multiplied_lane[4] ^= ((lane[3] << 2) & 0xff) ^ ((lane[7] << 3) & 0xff)
-    multiplied_lane[5] ^= ((lane[4] << 2) & 0xff)
-
-
-    # binary matrix m3
-    multi_mat_l6_m3 = 0
-    l6 = lane[6]
-    multi_mat_l6_m3 ^= (l6 & 0x1)
-    multi_mat_l6_m3 ^= (l6 & 0x2)
-    multi_mat_l6_m3 ^= (l6 & 0x4)
-    multi_mat_l6_m3 ^= (l6 & 0x8)
-    multi_mat_l6_m3 ^= (l6 & 0x10)
-
-
-    multiplied_lane[2] ^= multi_mat_l6_m3
-
-    return multiplied_lane
-
-
 def _multiply_MR3(lane):
     multiplied_lane = [lane[(byte+3) % 8] for byte in range(0, 8)]
 
@@ -193,6 +182,6 @@ ALPHAS = (
     _multiplication(M2),
     _multiplication(M3),
     _multiplication(MR, reverse=False),
-    _multiply_MR2,
+    _multiplication(MR2, reverse=False),
     _multiply_MR3
 )