Multiple updates and refactorings (#280)

deep_gemm/testing/numeric.py

@@ -5,6 +5,8 @@ from typing import Iterable
 def calc_diff(x: torch.Tensor, y: torch.Tensor):
     x, y = x.double(), y.double()
     denominator = (x * x + y * y).sum()
+    if denominator == 0:    # Which means that all elements in x and y are 0
+        return 0.0
     sim = 2 * (x * y).sum() / denominator
     return 1 - sim