chundoong-lab-ta/SamsungDS22/submissions/HW2/ss1.eom/mat_mul.cpp

103 lines
2.3 KiB
C++

#include "mat_mul.h"
#include <cstdlib>
#include <cstdio>
#include <pthread.h>
#include <algorithm>
static float *A, *B, *C;
static int M, N, K;
static int num_threads;
static void* mat_mul_thread(void *data) {
// TODO: parallelize & optimize matrix multiplication
//for (int i = 0; i < M; ++i) {
// for (int j = 0; j < N; ++j) {
// for (int k = 0; k < K; ++k) {
// C[i * N + j] += A[i * K + k] * B[k * N + j];
// }
// }
//}
int pid = * (int *) data;
int slice = M / num_threads;
//int slice = 210;
int start = pid * slice;
int end = pid == num_threads - 1 ? M : (pid + 1) * slice;
//float Aik;
int bs = 40;
short k_min;
//float* _B;
// _B = (float*) malloc(sizeof(float) * 4096);
// for (int k =0; k<K; k++)
// for (int j=0; j<N; j++)
// _B[k*N+j]= B[j*N+k];
//
for (int kk = 0; kk < K; kk += bs) {
k_min = std::min(kk+bs,K);
//for (int jj = 0; jj < N; jj += bs) {
//j_min = std::min(jj + bs, N);
//j_min = j_min>>2;
for (int i = start; i < end; ++i) {
//for (int k = kk; k < std::min(kk + bs, K); ++k) {
for (int k = kk; k < k_min; ++k) {
//for (int j = jj; j < j_min; j=j+1) {
//Aik = A[i * K + k];
for (int j = 0; j < N; j=j+1) {
//for (int j = jj; j < std::min(jj + bs, N); ++j) {
//C[i * N + j] += Aik * B[k * N + j];
C[i * N + j] += A[i*K +k] * B[k * N + j];
//C[i * N + j] += A[i*K +k] * _B[j * N + k];
}
}
//}
}
}
//free(_B);
return NULL;
}
void mat_mul(float *_A, float *_B, float *_C, int _M, int _N, int _K, int _num_threads) {
A = _A, B = _B, C = _C;
M = _M, N = _N, K = _K;
num_threads = _num_threads;
//// TODO: create '_num_threads' pthreads
//pthread_t thread;
//pthread_create(&thread, NULL, mat_mul_thread, NULL);
//pthread_join(thread, NULL);
pthread_t * threads;
threads = (pthread_t *) malloc(sizeof(pthread_t) * num_threads);
for (int i = 0; i < num_threads; i++) {
int * pid = (int *) malloc(sizeof(int));
*pid = i;
pthread_create(&threads[i], NULL, mat_mul_thread, pid);
}
for (int i = 0; i < num_threads; i++) {
pthread_join(threads[i], NULL);
}
}