Quantize annotate assertion in add_rewrite

tico · July 2, 2019, 1:46pm

Hi,

I am trying to quantize a TensorFlow model but I get an assertion in add_rewrite as shown as follows:

File "/home/tvm/tvm/python/tvm/relay/quantize/_annotate.py", line 263, in add_rewrite   
assert lhs_kind == QAnnotateKind.ACTIVATION TVMError: AssertionError

Any ideas on how to fix this?

Thanks

vinx13 · July 3, 2019, 3:24am

This line has been removed. https://github.com/dmlc/tvm/blob/master/python/tvm/relay/quantize/_annotate.py#L241

Can you try latest master?

tico · July 3, 2019, 7:17am

Hi,

I tried the latest master but I get the error. In the current master the assertion is actually still there at line 263:

github.com

dmlc/tvm/blob/master/python/tvm/relay/quantize/_annotate.py#L263


    # quantize lhs to INPUT field if it is normal expression
    assert rhs_kind == QAnnotateKind.INPUT
    lhs_expr = attach_simulated_quantize(lhs_expr, QAnnotateKind.INPUT)
    expr = _forward_op(ref_call, [lhs_expr, rhs_expr])
    return QAnnotateExpr(expr, QAnnotateKind.INPUT)


if lhs_kind is not None and rhs_kind is None:
    if isinstance(rhs_expr, _expr.Constant):
        # quantize rhs to WEIGHT field if it is Constant
        rhs_expr = attach_simulated_quantize(rhs_expr, QAnnotateKind.WEIGHT)
        assert lhs_kind == QAnnotateKind.ACTIVATION
        expr = _forward_op(ref_call, [lhs_expr, rhs_expr])
        return QAnnotateExpr(expr, QAnnotateKind.ACTIVATION)
    else:
        # quantize rhs to INPUT field if it is not Constant
        rhs_expr = attach_simulated_quantize(rhs_expr, QAnnotateKind.INPUT)
        raise ValueError


if lhs_kind is not None and rhs_kind is not None:
    if lhs_kind == QAnnotateKind.INPUT and rhs_kind == QAnnotateKind.INPUT:
        expr = _forward_op(ref_call, [lhs_expr, rhs_expr])

What line did you mean it was removed?

Thanks

vinx13 · July 3, 2019, 7:41am

Basically this assertion means that you are adding a bias to some activation (int32 result) and there might be some cases missing here. So you can add a check on lhs_kind and rhs_kind and then handle that case

tico · July 3, 2019, 9:35am

Hi,

Indeed I have biases in my model. By handling do you mean skipping those cases? or what actions I would need to consider to handle these cases?

Also I am not yet 100% sure of the meaning of lhs and rhs in this context and also about the QAnnotateKind. Could you clarify me a bit this?

Thanks a lot

vinx13 · July 3, 2019, 10:12am

You should handle it like the other cases.
QAnnotateKind.ACTIVATION means the expression is output of a quantized layer (e.g. output of quantized conv2d)
QAnnotateKind.INPUT means the expression has been quantized to int8

tico · July 4, 2019, 8:13am

I am still trying to figure out how to handle this. However, I realized that by using the NCHW layout there is no issue but if I use the default layout is when I hit the assertion. The problem with NCHW is that I see lots of transpose operations being added in the Relay IR