#include "mat_mul.h"

#include <cstdlib>
#include <cstdio>
#include <pthread.h>

#define BLOCKSIZE 32



 #ifndef min
 #define min(a,b)  (((a) < (b)) ? (a) : (b))
 #endif

static float *A, *B, *C;
static int M, N, K;
static int num_threads;

static void* worker(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 = BLOCKSIZE;
  int ssize;
  int j;

/*
  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 < min(kk + bs, K); ++k) {
          Aik = A[i * K + k];
          
          ssize = (min(jj + bs, N)/8)*8;
          for (j = jj; j < ssize; j+=8  ) {
            C[i * N + j] += Aik * B[k * N + j];
            C[i * N + j+1] += Aik * B[k * N + j+1]; 
            C[i * N + j+2] += Aik * B[k * N + j+2];
            C[i * N + j+3] += Aik * B[k * N + j+3];
            C[i * N + j+4] += Aik * B[k * N + j+4];
            C[i * N + j+5] += Aik * B[k * N + j+5];
            C[i * N + j+6] += Aik * B[k * N + j+6];
            C[i * N + j+7] += Aik * B[k * N + j+7];
          }
          for(j;j<min(jj + bs, N);j++){
            C[i * N + j] += Aik * B[k * N + j];
          }
          
          
          
        }
      }
    }
  }
*/


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) { 
            Aik = A[i * K + k];
             
            ssize = (N/8)*8;
            for (j = 0; j < ssize; j+=8  ) {
              C[i * N + j] += Aik * B[k * N + j];
              C[i * N + j+1] += Aik * B[k * N + j+1]; 
              C[i * N + j+2] += Aik * B[k * N + j+2];
              C[i * N + j+3] += Aik * B[k * N + j+3];
              C[i * N + j+4] += Aik * B[k * N + j+4];
              C[i * N + j+5] += Aik * B[k * N + j+5];
              C[i * N + j+6] += Aik * B[k * N + j+6];
              C[i * N + j+7] += Aik * B[k * N + j+7];
            }
            for(j;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, worker, pid);
}

for (int i = 0; i < num_threads; i++) {
  pthread_join(threads[i], NULL);
}
}