Exemplo n.º 1
0
        public static int FindMoveIndex(MGMove[] moves, ConverterMGMoveEncodedMove.FromTo moveSquares, int startIndex, int numMovesUsed)
        {
            short fromAndTo = moveSquares.FromAndToCombined;

            // partially unroll the loop to improve instruction-level parallelism
            int i = startIndex;

            while (i < numMovesUsed - 3)
            {
                if (moves[i].FromAndToCombined == fromAndTo)
                {
                    return(i);
                }
                if (moves[i + 1].FromAndToCombined == fromAndTo)
                {
                    return(i + 1);
                }
                if (moves[i + 2].FromAndToCombined == fromAndTo)
                {
                    return(i + 2);
                }
                if (moves[i + 3].FromAndToCombined == fromAndTo)
                {
                    return(i + 3);
                }

                i += 4;
            }

            while (i < numMovesUsed)
            {
                if (moves[i].FromAndToCombined == fromAndTo)
                {
                    return(i);
                }

                i++;
            }

            return(-1);
        }
Exemplo n.º 2
0
        // --------------------------------------------------------------------------------------------
        internal unsafe static int FindMoveIndexAVX(MGMove[] moves, ConverterMGMoveEncodedMove.FromTo moveSquares, int startIndex, int numMovesUsed)
        {
            // Use non-AVX version if few move to check
            if (numMovesUsed - startIndex < 12)
            {
                return(MoveInMGMovesArrayLocator.FindMoveIndex(moves, moveSquares, startIndex, numMovesUsed));
            }

            void *     ptrStart = Unsafe.AsPointer(ref moves[0]);
            Span <int> ints     = new Span <int>(ptrStart, numMovesUsed);

            int foundIndex = FindIndexOfShortAtEvenIndexHavingValue(ints, moveSquares.FromAndToCombined, startIndex, numMovesUsed - 1);

            if (foundIndex == -2)
            {
                // The AVX routine found a false pseudo-match at odd index
                // Fallback to non AVX version
                // This is expected to happen only very rarely
                return(MoveInMGMovesArrayLocator.FindMoveIndex(moves, moveSquares, startIndex, numMovesUsed));
            }

            return(foundIndex);
        }