Specify the operand data type constraints of operation #283
Description
The current spec doesn't specify the operand type constraints of an operation. However, some operations, e.g., softmax should only support float32 operand type according to the survey of frameworks and native ML APIs in the following table. The lack of the operand type constraints specification would lead to implementation issue, such as Chromium CL 3856752.
| Framework / API | supported data types |
|---|---|
| TensorFlow tf.nn.softmax | half, float32, float64 |
| ONNX Softmax | tensor(float16), tensor(float), tensor(double), tensor(bfloat16) |
| NNAPI ANEURALNETWORKS_SOFTMAX | FLOAT32, FLOAT16 |
| DirectML DML_ACTIVATION_SOFTMAX_OPERATOR_DESC | FLOAT32, FLOAT16 |
| BNNS ActivationFunction | float |
Thanks @wacky6 for pointing this out.