chundoong-lab-ta/SamsungDS22/submissions/HW2/taekyung.yeo/mat_mul.cpp

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2022-09-29 18:01:45 +09:00
#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) {
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 = 32;
for (int kk=0; kk<K; kk+=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=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;
pthread_t * thread;
thread = (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(&thread[i], NULL, mat_mul_thread, pid);
}
for (int i=0; i<num_threads; i++){
pthread_join(thread[i], NULL);
}
}