chundoong-lab-ta/SamsungDS22/submissions/HW5/ys798.choi/kernel.cl

79 lines
2.4 KiB
Common Lisp

// Constants for kernels 1 -- 5
#define TS 32 // The square-root of the 2D tile-size (== work-group dims)
// Constants for kernels 3, 5
#define WPT 8 // The amount of work-per-thread, i.e. the thread-coarsening factor
#define RTS (TS/WPT) // The reduced tile-size in one dimension
// Increased the amount of work-per-thread by a factor WPT
__kernel void sgemm(const __global float* A,
const __global float* B,
__global float* C,
const int M, const int N, const int K) {
// Thread identifiers
const int row = get_local_id(0); // Local row ID (max: TS)
const int col = get_local_id(1); // Local col ID (max: TS/WPT == RTS)
const int globalRow = TS*get_group_id(0) + row; // Row ID of C (0..M)
const int globalCol = TS*get_group_id(1) + col; // Col ID of C (0..N)
// Local memory to fit a tile of TS*TS elements of A and B
__local float Asub[TS][TS];
__local float Bsub[TS][TS];
// Initialise the accumulation registers
float c_temp[WPT];
for (int w=0; w<WPT; w++) {
c_temp[w] = 0.0f;
}
// Loop over all tiles
const int nTiles = (K + TS - 1) / TS;
for (int t=0; t<nTiles; t++) {
// Load one tile of A and B into local memory
for (int w=0; w<WPT; w++) {
const int tiledRow = TS*t + row;
const int tiledCol = TS*t + col;
if(globalRow + w*RTS < M && tiledCol < K)
{
Asub[row + w*RTS][col] = A[(globalRow + w*RTS)*K + tiledCol];
}
else
{
Asub[row + w*RTS][col] = 0.0f;
}
if(globalCol < N && tiledRow + w*RTS < K)
{
Bsub[row + w*RTS][col] = B[(tiledRow + w*RTS)*N + globalCol];
}
else
{
Bsub[row + w*RTS][col] = 0.0f;
}
}
// Synchronise to make sure the tile is loaded
barrier(CLK_LOCAL_MEM_FENCE);
// Perform the computation for a single tile
for (int k=0; k<TS; k++) {
for (int w=0; w<WPT; w++) {
c_temp[w] += Asub[row + w*RTS][k] * Bsub[k][col];
}
}
// Synchronise before loading the next tile
barrier(CLK_LOCAL_MEM_FENCE);
}
// Store the final results in C
for (int w=0; w<WPT; w++) {
if(globalRow + w*RTS < M && globalCol < N)
{
C[(globalRow + w*RTS)*N + globalCol] = c_temp[w];
}
}
}