[BUG] matx::argmax returns weird results for tensors that have all-negative elements

[AtomicVar]

Describe the bug
When the input tensor has all-negative elements, like [-3, -1, -7], the matx::argmax returns weird index.

To Reproduce

#include <matx.h>

int main() {
  // Create a tensor with all negative elements
  auto t = matx::make_tensor<float, 1>({3});
  t.SetVals({-3, -1, -7});
  t.Print();

  // Apply matx::argmax
  matx::tensor_t<float, 0> max_val{};
  matx::tensor_t<matx::index_t, 0> max_idx{};
  matx::argmax(max_val, max_idx, t);
  max_val.Print();
  max_idx.Print();

  return 0;
}

Output:

000000: -3.0000e+00 
000001: -1.0000e+00 
000002: -7.0000e+00 
1.1755e-38 
9223372036854775807

The max_val is 1.1755e-38 and max_idx is 9223372036854775807 which make no sense.

Expected behavior
The max_val should be -1 and max_idx should be 1.

System details (please complete the following information):

• OS: Ubuntu 20.04
• CUDA version: CUDA 11.4
• g++ version: 9.3.0

[cliffburdick]

Hi @ZJUGuoShuai this has been fixed. Sorry for the delay.