chundoong-lab-ta/SamsungDS22/submissions/HW2/jinho.yi/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>
#define bs 32
#define min(a, b) (((a) < (b)) ? (a) : (b))
#define max(a, b) (((a) > (b)) ? (a) : (b))
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 chunk = M / num_threads;
int start = pid * chunk;
int end = pid == num_threads - 1 ? M : (pid + 1) * chunk;
float tmp;
for (int kk = 0; kk < K; kk += bs) {
for (int i = start; i < end; ++i) {
for (int k = kk; k < min(kk + bs, K); ++k) {
tmp = A[i * K + k];
for (int j = 0; j < N; ++j) {
C[i * N + j] += tmp * 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[num_threads];
int pid[num_threads];
for (int i = 0; i < num_threads; i++) {
pid[i] = i;
pthread_create(&thread[i], NULL, mat_mul_thread, (void*) &pid[i]);
}
for (int i = 0; i < num_threads; i++) {
pthread_join(thread[i], NULL);
}
}