echuraev commented on code in PR #13119:
URL: https://github.com/apache/tvm/pull/13119#discussion_r1001805009
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python/tvm/relay/frontend/onnx.py:
##########
@@ -926,10 +926,45 @@ def _impl_v1(cls, inputs, attr, params):
return _op.multiply(term1, term2)
+class FastGelu(OnnxOpConverter):
+ """Operator converter for FastGelu from Microsoft onnxruntime contrib
opset.
+
+ fast_gelu(x) = 0.5x(1 + tanh(sqrt(2/pi)(x + 0.044715x^3)))
+ = 0.5x(1 + tanh((sqrt(2/pi)x + 0.044715(sqrt(2/pi)x^3)))
+ = 0.5x(1 + tanh(c1 * x + c2 * x^3)))
+ , where
+ c1 = sqrt(2/pi)
+ c2 = 0.044715 * sqrt(2/pi)
+ """
+
+ @classmethod
+ def _impl_v1(cls, inputs, attr, params):
+ x = inputs[0]
+ if inputs[1]:
+ bias = inputs[1]
+ bias_shape = infer_shape(bias)
+ assert len(bias_shape) == 1, "bias term must be a 1D tensor"
+ x += bias
+
+ # Declare consts
+ const_dtype = infer_type(x).checked_type.dtype
+ half = _expr.const(0.5, dtype=const_dtype)
+ one = _expr.const(1.0, dtype=const_dtype)
+ const1 = _expr.const(0.7978845608028654, dtype=const_dtype) #
sqrt(2.0 / PI)
+ const2 = _expr.const(0.0356774081363001, dtype=const_dtype) #
0.044715 * sqrt(2.0 / PI)
Review Comment:
Let's return explicit calculation of these values if it is not affect on the
accuracy
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