public static uint[][] HistogramByteComponents(long[] inArray, Int32 l, Int32 r)
{
const int numberOfBins = 256;
const int numberOfDigits = sizeof(ulong);
uint[][] count = new uint[numberOfDigits][];
for (int i = 0; i < numberOfDigits; i++)
{
count[i] = new uint[numberOfBins];
}
var union = new Int64ByteUnion();
for (int current = l; current <= r; current++) // Scan the array and count the number of times each digit value appears - i.e. size of each bin
{
union.integer = inArray[current];
count[0][union.byte0]++;
count[1][union.byte1]++;
count[2][union.byte2]++;
count[3][union.byte3]++;
count[4][union.byte4]++;
count[5][union.byte5]++;
count[6][union.byte6]++;
count[7][((ulong)inArray[current] >> 56) ^ 128]++;
}
return(count);
}
public static Tuple <uint[][], int> HistogramByteComponentsAndStatistics(long[] inArray, Int32 l, Int32 r)
{
const int numberOfBins = 256;
const int numberOfDigits = sizeof(ulong);
uint[][] count = new uint[numberOfDigits][];
for (int i = 0; i < numberOfDigits; i++)
{
count[i] = new uint[numberOfBins];
}
int numElementsPreSorted = 0;
var union = new Int64ByteUnion();
int current = l;
if (current <= r)
{
union.integer = inArray[current];
count[0][union.byte0]++;
count[1][union.byte1]++;
count[2][union.byte2]++;
count[3][union.byte3]++;
count[4][union.byte4]++;
count[5][union.byte5]++;
count[6][union.byte6]++;
count[7][((ulong)inArray[current] >> 56) ^ 128]++;
current++;
numElementsPreSorted++; // initial single array element is considered sorted, since there is only a single element
}
for (; current <= r; current++) // Scan the array and count the number of times each digit value appears - i.e. size of each bin
{
union.integer = inArray[current];
count[0][union.byte0]++;
count[1][union.byte1]++;
count[2][union.byte2]++;
count[3][union.byte3]++;
count[4][union.byte4]++;
count[5][union.byte5]++;
count[6][union.byte6]++;
count[7][((ulong)inArray[current] >> 56) ^ 128]++;
// TODO: It should be possible to take the if/branch out, possibly by using SIMD/SSE or by separating the > from the ==, where ? can be done with a subtraction
// and equal with XOR followed by a subtraction from all 1's
if (inArray[current] >= inArray[current - 1])
{
numElementsPreSorted++;
}
}
return(new Tuple <uint[][], int>(count, numElementsPreSorted));
}
public static int[] HistogramByteComponentsUsingUnion(long[] inArray, Int32 l, Int32 r, int shiftRightAmount)
{
const int numberOfBins = 256;
int[] count = new int[numberOfBins];
int whichByte = shiftRightAmount / 8;
var union = new Int64ByteUnion();
switch (whichByte)
{
case 0:
for (int current = l; current <= r; current++) // Scan the array and count the number of times each digit value appears - i.e. size of each bin
{
union.integer = inArray[current];
count[union.byte0]++;
}
break;
case 1:
for (int current = l; current <= r; current++)
{
union.integer = inArray[current];
count[union.byte1]++;
}
break;
case 2:
for (int current = l; current <= r; current++)
{
union.integer = inArray[current];
count[union.byte2]++;
}
break;
case 3:
for (int current = l; current <= r; current++)
{
union.integer = inArray[current];
count[union.byte3]++;
}
break;
case 4:
for (int current = l; current <= r; current++)
{
union.integer = inArray[current];
count[union.byte4]++;
}
break;
case 5:
for (int current = l; current <= r; current++)
{
union.integer = inArray[current];
count[union.byte5]++;
}
break;
case 6:
for (int current = l; current <= r; current++)
{
union.integer = inArray[current];
count[union.byte6]++;
}
break;
case 7:
for (int current = l; current <= r; current++)
{
count[((ulong)inArray[current] >> shiftRightAmount) ^ 128]++;
}
break;
}
return(count);
}