chundoong-lab-ta/SamsungDS22/submissions/HW2/s.hyundeok/mat_mul.cpp

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2022-09-29 18:01:45 +09:00
#include "mat_mul.h"
#include <algorithm>
#include <cstdlib>
#include <cstdio>
#include <pthread.h>
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
//
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;
for (int kk=0; kk< K; kk+=32){
for(int i=start; i<end; i++){
for(int k = kk; k < ((kk+32)<K ? (kk+32):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;
// TODO: create '_num_threads' pthreads
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);
}
}