Remove two if statements in fp8 padding (pytorch#935)

Reviewed By: vkuzo

Differential Revision: D63051205

Pull Request resolved: pytorch#935
Approved by: https://github.com/vkuzo

Author: y-sq

torchao/float8/float8_utils.py

@@ -198,9 +198,7 @@ def _get_min_alignment(size: int, alignment_value: int) -> int:
         16
     ```
     """
-    if size % alignment_value == 0:
-        return size
-    return (1 + (size // alignment_value)) * alignment_value
+    return (1 + ((size - 1) // alignment_value)) * alignment_value
 
 
 def pad_tensor_for_matmul(
@@ -236,10 +234,6 @@ def pad_tensor_for_matmul(
     dim1_aligned = _get_min_alignment(dim1, 16) if 0 in dims else dim1
     dim2_aligned = _get_min_alignment(dim2, 16) if 1 in dims else dim2
 
-    # Check if padding is needed for either dimension
-    if dim1 == dim1_aligned and dim2 == dim2_aligned:
-        return tensor
-
     # Calculate padding values for both dimensions
     pad_dim1 = dim1_aligned - dim1
     pad_dim2 = dim2_aligned - dim2