PhraseSet.FillPhraseSet rewritten to use pointers only

dotnet/WhiteRabbit/PhraseSet.cs

@@ -19,13 +19,16 @@
                 {
                     fixed (int* wordIndexesPointer = wordIndexes)
                     {
-                        FillPhraseSet(bufferPointer, allWords, wordIndexesPointer, permutationsPointer, permutationOffset, numberOfCharacters, wordIndexes.Length);
+                        fixed (Word* allWordsPointer = allWords)
+                        {
+                            FillPhraseSet(bufferPointer, (long*)allWordsPointer, wordIndexesPointer, permutationsPointer, permutationOffset, numberOfCharacters, wordIndexes.Length);
+                        }
                     }
                 }
             }
         }
 
-        private static unsafe void FillPhraseSet(long* bufferPointer, Word[] allWords, int* wordIndexes, ulong* permutationsPointer, int permutationOffset, int numberOfCharacters, int numberOfWords)
+        private static unsafe void FillPhraseSet(long* bufferPointer, long* allWordsPointer, int* wordIndexes, ulong* permutationsPointer, int permutationOffset, int numberOfCharacters, int numberOfWords)
         {
             long* longBuffer = (long*)bufferPointer;
 
@@ -41,13 +44,13 @@
                 var cumulativeWordOffsetX4 = 0;
                 for (var j = 0; j < numberOfWords; j++)
                 {
-                    var currentWord = allWords[wordIndexes[permutation & 15]];
+                    var currentWord = allWordsPointer + wordIndexes[permutation & 15] * 128;
                     permutation = permutation >> 4;
-                    longBuffer[0] |= currentWord.Buffers[cumulativeWordOffsetX4 + 0];
-                    longBuffer[1] |= currentWord.Buffers[cumulativeWordOffsetX4 + 1];
-                    longBuffer[2] ^= currentWord.Buffers[cumulativeWordOffsetX4 + 2];
-                    longBuffer[3] ^= currentWord.Buffers[cumulativeWordOffsetX4 + 3];
-                    cumulativeWordOffsetX4 += currentWord.LengthX4;
+                    longBuffer[0] |= currentWord[cumulativeWordOffsetX4 + 0];
+                    longBuffer[1] |= currentWord[cumulativeWordOffsetX4 + 1];
+                    longBuffer[2] ^= currentWord[cumulativeWordOffsetX4 + 2];
+                    longBuffer[3] ^= currentWord[cumulativeWordOffsetX4 + 3];
+                    cumulativeWordOffsetX4 += unchecked((int)currentWord[127]);
                 }
 
                 longBuffer += 4;

dotnet/WhiteRabbit/Word.cs

@@ -1,19 +1,8 @@
 namespace WhiteRabbit
 {
-    class Word
+    internal unsafe struct Word
     {
-        public byte[] Original;
-
-        public long[] Buffers { get; }
-
-        public int LengthX4 { get; }
-
-        private Word()
-        {
-            this.Original = new byte[0];
-            this.Buffers = new long[128];
-            this.LengthX4 = 0;
-        }
+        public fixed long Buffers[128];
 
         public unsafe Word(byte[] word)
         {
@@ -24,10 +13,7 @@
                 tmpWord[i] = word[i];
             }
 
-            this.Original = tmpWord;
-
-            var buffers = new long[128];
-            fixed (long* buffersPointer = buffers)
+            fixed (long* buffersPointer = this.Buffers)
             {
                 for (var i = 0; i < 32; i++)
                 {
@@ -39,10 +25,9 @@
                         *currentPointer = tmpWord[j];
                     }
                 }
-            }
 
-            this.Buffers = buffers;
-            this.LengthX4 = tmpWord.Length * 4;
+                buffersPointer[127] = tmpWord.Length * 4;
+            }
         }
 
         private static Word Empty { get; } = new Word();