C++amp矩陣分塊

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參考自：https://msdn.microsoft.com/en-us/library/hh873135.aspx

#include <iostream>#include <iomanip>#include <amp.h>using namespace concurrency;const int ROWS = 8;const int COLS = 9;// tileRow and tileColumn specify the tile that each thread is in.// globalRow and globalColum specify the location of the thread in the array_view.// localRow and localColumn specify the location of the thread relativie to  the tile.struct Description{int value;int tileRow;int tileColumn;int globalRow;int globalColumn;int localRow;int localColumn;};// A helper function for formatting the output.void SetConsoleColor(int color){int colorValue = (color == 4) ? 4 : 2;SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE), colorValue);}// A helper function for farmatting the output.void SetConsoleSize(int height, int width){COORD coord; coord.X = width; coord.Y = height;SetConsoleScreenBufferSize(GetStdHandle(STD_OUTPUT_HANDLE), coord);SMALL_RECT *rect = new SMALL_RECT();rect->Left = 0;rect->Top = 0;rect->Right = width;rect->Bottom = height;SetConsoleWindowInfo(GetStdHandle(STD_OUTPUT_HANDLE), true, rect);}// This method creates an 8 x 9 matrix of Description structures. In the// call to parallel_for_each, the structure is updated with tile,global, and local indices.void TilingDescription(){// Create 72(8x9) Description structures.std::vector<Description> descs;for (int i = 0; i < ROWS * COLS; i++){Description d = { i, 0, 0, 0, 0, 0, 0 };descs.push_back(d);}// Create an array_view from the Description structures.extent<2> matrix(ROWS, COLS);array_view<Description, 2> descriptions(matrix, descs);// Update each Description with the tile, global. and local indices.parallel_for_each(descriptions.extent.tile<2, 3>(),[=](tiled_index<2, 3> t_idx) restrict(amp){descriptions[t_idx].globalRow = t_idx.global[0];descriptions[t_idx].globalColumn = t_idx.global[1];descriptions[t_idx].tileRow = t_idx.tile[0];descriptions[t_idx].tileColumn = t_idx.tile[1];descriptions[t_idx].localRow = t_idx.local[0];descriptions[t_idx].localColumn = t_idx.local[1];});// Print out the Description structure for each element in the matrix.// Tiles are displayed in red and green to distinguish them from each other.SetConsoleSize(100, 150);for (int row = 0; row < ROWS; row++){for (int column = 0; column < COLS; column++){SetConsoleColor((descriptions(row, column).tileRow + descriptions(row, column).tileColumn) % 2);std::cout << "Value: " << std::setw(2) << descriptions(row, column).value << "    ";}std::cout << "\n";for (int column = 0; column < COLS; column++){SetConsoleColor((descriptions(row, column).tileRow + descriptions(row, column).tileColumn) % 2);std::cout << "Tile: " << "(" << descriptions(row, column).tileRow << "," << descriptions(row, column).tileColumn << ") ";}std::cout << "\n";for (int column = 0; column < COLS; column++){SetConsoleColor((descriptions(row, column).tileRow + descriptions(row, column).tileColumn) % 2);std::cout << "Global: " << "(" << descriptions(row, column).globalRow << "," << descriptions(row, column).globalColumn << ")";}std::cout << "\n";for (int column = 0; column < COLS; column++){SetConsoleColor((descriptions(row, column).tileRow + descriptions(row, column).tileColumn) % 2);std::cout << "Local: " << "(" << descriptions(row, column).localRow << "," << descriptions(row, column).localColumn << ")";}std::cout << "\n";std::cout << "\n";}}#define SAMPLESIZE 2#define MATRIXSIZE 8void SamplingExample(){// Create data and array_view for the matrix.std::vector<float> rawData;for (int i = 0; i < MATRIXSIZE * MATRIXSIZE; i++){rawData.push_back((float)i);}extent<2> dataExtent(MATRIXSIZE, MATRIXSIZE);array_view<float, 2> matrix(dataExtent, rawData);// Create the array for  the averages.// There is one element in the output for each tile in the data.std::vector<float> outputData;int outputSize = MATRIXSIZE / SAMPLESIZE;for (int j = 0; j < outputSize * outputSize; j++){outputData.push_back((float)0);}extent<2> outputExtent(MATRIXSIZE / SAMPLESIZE, MATRIXSIZE / SAMPLESIZE);array<float, 2> averages(outputExtent, outputData.begin(), outputData.end());// Use tiles that are SAMPLESIZE x SAMPLESIZE// Find the average of the values in each tile.// The only reference-type variable you can pass into the parallel_fo_each_call// is a concurrency::array.parallel_for_each(matrix.extent.tile<SAMPLESIZE, SAMPLESIZE>(),[=, &averages](tiled_index<SAMPLESIZE, SAMPLESIZE> t_idx) restrict(amp){// Copy the values of the tile into a tile-sized array.tile_static float tileValues[SAMPLESIZE][SAMPLESIZE];tileValues[t_idx.local[0]][t_idx.local[1]] = matrix[t_idx];// Wait for the tile-sized array to load before you calculate the average.t_idx.barrier.wait();// IF you remove the if statement, then the  calculation executes for every// thread in the tile, and makes the same assignemnt to averages each time.if (t_idx.local[0] == 0 && t_idx.local[1] == 0){for (int trow = 0; trow < SAMPLESIZE; trow++){for (int tcol = 0; tcol < SAMPLESIZE; tcol++){averages(t_idx.tile[0], t_idx.tile[1]) += tileValues[trow][tcol];}}averages(t_idx.tile[0], t_idx.tile[1]) /= (float)(SAMPLESIZE * SAMPLESIZE);}});// Print out the results.// You cannot access the values in aveages directly. You must copy them// vack to a CPU variable.outputData = averages;for (int row = 0; row < outputSize; row++){for (int col = 0; col < outputSize; col++){std::cout << outputData[row * outputSize + col] << " ";}std::cout << "\n";}// Output for SAMPLESSIZE = 2 is:// 4.5  6.5  8.5  10.5// 20.5 22.5 24.5 26.5// 36.5 38.5 40.5 42.5// 52.5 54.5 56.5 58.5// Output for SAMPLESIZE = 4 is:// 13.5  17.5// 45.5  49.5}void main(){//TilingDescription();SamplingExample();char wait;std::cin >> wait;}

　　

C++amp矩陣分塊