Avoid copy for y2.

Rev: nettle/misc/serpent-sbox6i.dot:1.2

misc/serpent-sbox6i.dot

 strict digraph sbox6i {
-  x0 [shape=box, label="\N"];
-  x1 [shape=box, label="\N"];
-  x2 [shape=box, label="\N"];
-  x3 [shape=box, label="\N"];
+  x0 [shape=box];
+  x1 [shape=box];
+  x2 [shape=box];
+  x3 [shape=box];
 
-  y0 [shape=box, label="\N"];
-  y1 [shape=box, label="\N"];
-  y2 [shape=box, label="\N"];
-  y3 [shape=box, label="\N"];
-
-  // To get to y1, we need to save t02
-  // To get to y3, we need to save y1, t02, t05, t07, t01
-  // To get to y0, we need to save t02, t07, t05, t01
+  y0 [shape=box];
+  y1 [shape=box];
+  y2 [shape=box];
+  y3 [shape=box];
 
   // Get to y1
-  t02 [label="\N\ny3\n1"];
-  t06 [label="\N\ny0\n2"];
-  t08 [label="\N\ny1\n3"];
-  y1  [label="\N\n4"];
+  t01 [label="\N\ny2\n1"];
+  t02 [label="\N\nx2\n2"];
+  t06 [label="\N\ny0\n3"];
+  t08 [label="\N\ny1\n4"];
+  y1  [label="\N\n5"];
   // Get to t05
-  t01 [label="\N\nx2\n4"];
-  t03 [label="\N\ny2\n5"];
-  t05 [label="\N\ny2\n6"];
+  t03 [label="\N\ny3\n6"];
+  t05 [label="\N\ny3\n7"];
   // Get to t07
-  t16 [label="\N\nx3\n7"];
-  t04 [label="\N\ny3\n8"];
-  t07 [label="\N\ny3\n9"];  
+  t16 [label="\N\nx3\n8"];
+  t04 [label="\N\nx2\n9"];
+  t07 [label="\N\nx2\n10"];  
   // Get to y0
-  t09 [label="\N\ny0\n10"];
-  y0  [label="\N\n11"];
+  t09 [label="\N\ny0\n11"];
+  y0  [label="\N\n12"];
   // Get to y3
-  t13 [label="\N\ny2\n12"];
-  t15 [label="\N\ny3\n13"];
-  t17 [label="\N\nx0\n14"];
-  y3  [label="\N\n15"];
+  t13 [label="\N\ny3\n13"];
+  t15 [label="\N\ny3\n14"];
+  t17 [label="\N\nx0\n15"];
+  y3  [label="\N\n16"];
   // Get to y2
-  t12 [label="\N\nx1\n16"];
-  t14 [label="\N\ny2\n17"];
-  y2  [label="\N\n18"];
-  
-  // t02 [label="\N\nx2\n1"];
-  // t08 [label="\N\ny1\n2"];
-  // t06 [label="\N\ny2\n3"];
-  // y1  [label="\N\n4", shape=box];
-  // t04 [label="\N\ny0\n6"];
-  // t07 [label="\N\ny0\n7"];
-  // t16 [label="\N\nx2\n9"];
-  // t03 [label="\N\ny2\n10"];
-  // t05 [label="\N\nx3\n11"];
-  
+  t12 [label="\N\nx1\n17"];
+  t14 [label="\N\ny2\n18"];
+  y2  [label="\N\n19"];
+    
   x0  -> t01; x2 -> t01;  // t01 = x0  ^ x2;
   x2  -> t02;             // t02 =     ~ x2;
   x1  -> t03; t01-> t03;  // t03 = x1  & t01;