chundoong-lab-ta/SamsungDS22/submissions/HW2/yk77.oh/mat_mul.cpp

77 lines
1.7 KiB
C++

#include "mat_mul.h"
#include <cstdlib>
#include <cstdio>
#include <pthread.h>
#include <algorithm>
#define blocksize 45
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 start = pid * slice;
int end = pid == num_threads - 1 ? M : (pid + 1) * slice;
float Aik;
int bs = blocksize;
for (int kk = 0; kk < K; kk += bs) {
//for (int jj = 0; jj < N; jj += bs) {
for (int i = start; i < end; ++i) {
for (int k = kk; k < std::min(kk + bs, K); ++k) {
Aik = A[i * K + k];
// for (int j = jj; j < std::min(jj + bs, N); ++j) {
for (int j = 0; j < N; ++j) {
C[i * N + j] += Aik * B[k * N + j];
}
}
}
//}
}
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);
}
}