message: Add validation of maximum values of input paramters
diff: #include "Matrix.h"
  #include "sgemm.hpp"
  +constexpr int MAX_ITERS = 1000000;
  +constexpr int MAX_M = 4096;
  +constexpr int MAX_TH = 4096;
  +
  static void usage() {
  fprintf(stderr, "usage: sgemm [gemm block] [niterations] [group threads width] [group threads height]\n");
  + fprintf(stderr, "\tmaximum size of gemm block: %d\n", MAX_M);
  + fprintf(stderr, "\tmaximum number of iterations: %d\n", MAX_ITERS);
  + fprintf(stderr, "\tmaximum value of group threads width/height: %d\n", MAX_TH);
  }
  int main(int argc, char *argv[]) {
  @@ -42,7 +49,8 @@ int main(int argc, char *argv[]) {
  gy = atoi(argv[4]);
  }
  }
  - if (m < 1 || niterations < 1 || gx < 1 || gy < 1) {
  + if (m < 1 || niterations < 1 || gx < 1 || gy < 1 ||
  + m > MAX_M || niterations > MAX_ITERS || gx > MAX_TH || gy > MAX_TH) {
  usage();
  return -1;
  }
  