feat: support aten.isnan converter (#2711)

py/torch_tensorrt/dynamo/conversion/aten_ops_converters.py

@@ -1517,6 +1517,23 @@ def aten_ops_isinf(
     )
 
 
+@dynamo_tensorrt_converter(torch.ops.aten.isnan.default)
+def aten_ops_isnan(
+    ctx: ConversionContext,
+    target: Target,
+    args: Tuple[Argument, ...],
+    kwargs: Dict[str, Argument],
+    name: str,
+) -> Union[TRTTensor, Sequence[TRTTensor]]:
+    return impl.unary.isnan(
+        ctx,
+        target,
+        SourceIR.ATEN,
+        name,
+        args[0],
+    )
+
+
 @dynamo_tensorrt_converter(torch.ops.aten.add.Tensor)
 @dynamo_tensorrt_converter(torch.ops.aten.add.Scalar)
 def aten_ops_add(

py/torch_tensorrt/dynamo/conversion/impl/unary/ops.py

@@ -508,3 +508,23 @@ def scalar_tensor(
     identity_layer = ctx.net.add_identity(tensor)
     set_layer_name(identity_layer, target, name, source_ir)
     return identity_layer.get_output(0)
+
+
+def isnan(
+    ctx: ConversionContext,
+    target: Target,
+    source_ir: Optional[SourceIR],
+    name: str,
+    input: TRTTensor,
+) -> TRTTensor:
+    # False for NaN elements since NaN is not equal to anything, including itself.
+    equality_result = impl.elementwise.eq(
+        ctx, target, source_ir, f"{name}_eq_nan", input, input
+    )
+
+    # Invert equality_result to get a mask where NaN values are marked as True.
+    nan_values_mask = logical_not(
+        ctx, target, source_ir, f"{name}_logical_not", equality_result
+    )
+
+    return nan_values_mask

tests/py/dynamo/conversion/test_isnan_aten.py

@@ -0,0 +1,82 @@
+import torch
+import torch.nn as nn
+from parameterized import parameterized
+from torch.testing._internal.common_utils import run_tests
+
+from .harness import DispatchTestCase
+
+
+class TestIsNanConverter(DispatchTestCase):
+    @parameterized.expand(
+        [
+            (
+                torch.tensor(
+                    [
+                        1.23,
+                        float("nan"),
+                        -4.56,
+                        float("inf"),
+                        float("-inf"),
+                        -100.0,
+                        float("nan"),
+                        0.13,
+                        -0.13,
+                        3.14159265,
+                    ]
+                ),
+            ),
+        ]
+    )
+    def test_isnan_float(self, data):
+        class isnan(nn.Module):
+            def forward(self, input):
+                return torch.ops.aten.isnan.default(input)
+
+        inputs = [data]
+        self.run_test(
+            isnan(),
+            inputs,
+            output_dtypes=[torch.bool],
+        )
+
+    @parameterized.expand(
+        [
+            (torch.full((2, 2), float("nan"), dtype=torch.float32),),
+            (torch.full((3, 10, 5), float("nan"), dtype=torch.float32),),
+            (torch.randn((5, 10, 5), dtype=torch.float32),),
+        ]
+    )
+    def test_isnan_dim(self, data):
+        class isnan(nn.Module):
+            def forward(self, input):
+                return torch.ops.aten.isnan.default(input)
+
+        inputs = [data]
+        self.run_test(
+            isnan(),
+            inputs,
+            output_dtypes=[torch.bool],
+        )
+
+    @parameterized.expand(
+        [
+            ((10,), torch.int, 0, 5),
+            ((1, 20), torch.int32, -10, 10),
+            ((2, 3, 4), torch.int, -5, 5),
+        ]
+    )
+    def test_isnan_int(self, input_shape, dtype, low, high):
+        class isnan(nn.Module):
+            def forward(self, input):
+                return torch.ops.aten.isnan.default(input)
+
+        inputs = [torch.randint(low, high, input_shape, dtype=dtype)]
+        self.run_test(
+            isnan(),
+            inputs,
+            output_dtypes=[torch.bool],
+        )
+
+
+if __name__ == "__main__":
+    run_tests()