[Relay to Onnx][LRN] (#8323)

* Added support for LRN operator

* [Relay to Onnx]

* Added unit test case for LRN

* * reformatted

* * reformatted (2)

* * fixed formatting issues in relay to onnx conversion script

* * fixed formatting
* change single quotes to double
* set space to 4 instead of 2

* * reformatted onnx.py: corrected spaces

* [Relay to Onnx] LRN

* Assert if axis != 1

* * fixed formatting

Co-authored-by: zxy844288792 <zhoxingy@amazon.com>

python/tvm/contrib/target/onnx.py

@@ -617,6 +617,22 @@ def convert_attributes(cls, attrs):
         return {"value": 1}
 
 
+class LRN(OpConverter):
+    """Operator converter for LRN."""
+
+    @classmethod
+    def convert_attributes(cls, attrs):
+        """axis attr is not supported as an argument in onnx.
+        Onnx only supports axis=1 (channels)."""
+        if attrs.get_int("axis") != 1:
+            raise RuntimeError(
+                "Unsupported axis %s in operator relay lrn operator. "
+                "Only axis = 1 is supported by Onnx." % (attrs.get_int("axis"))
+            )
+
+        return {"alpha": attrs.alpha, "beta": attrs.beta, "bias": attrs.bias, "size": attrs.size}
+
+
 relay_to_onnx_op_mapping = {
     "reshape": Reshape,
     "nn.conv2d": Conv,
@@ -650,6 +666,7 @@ def convert_attributes(cls, attrs):
     "layout_transform": LayoutTransform,
     "clip": Clip,
     "expand_dims": Expand,
+    "nn.lrn": LRN,
 }
 
 

tests/python/contrib/test_onnx.py

@@ -515,6 +515,21 @@ def verify_expand_dims(dshape, axis, num_newaxis, dtype="float32"):
     verify_expand_dims((1, 1, 1001), 2, 2)
 
 
+def test_lrn():
+    def verify_lrn(xshape, size, dtype="float32"):
+        x = relay.var("x", relay.ty.TensorType(xshape, dtype))
+        y = relay.nn.lrn(x, size=size, axis=1, alpha=1.0, beta=1.0, bias=1.0)
+        func = relay.Function([x], y)
+        x_data = np.random.uniform(size=xshape).astype(dtype)
+        verify_results(func, [x_data], "test_lrn", rtol=1e-5, atol=1e-5)
+
+    isize = [(1, 1, 480, 640), (1, 3, 224, 224)]
+    sizes = [1, 3]
+    for i in isize:
+        for s in sizes:
+            verify_lrn(i, s)
+
+
 if __name__ == "__main__":
     test_add()
     test_bias_add()
@@ -538,3 +553,4 @@ def verify_expand_dims(dshape, axis, num_newaxis, dtype="float32"):
     test_layout_transform()
     test_clip()
     test_expand_dims()
+    test_lrn()