[ET-VK][ez] Update requirements for partitioning to_dim_order_copy (#7949)

Pull Request resolved: #7859

## Context

The previous registration of the to dim order copy op is incorrect. Currently, there is no implementation for the op in the Vulkan backend, but since Vulkan manages memory layout internally the op node can be removed as long as the only thing being changed is dim order.

In some instances the op can be used to modify the dtype, in which case it will not be removed and the Vulkan delegate cannot execute the op correctly. Therefore, update the registration of the op to reflect this restriction.

This diff should unblock enabling dim order ops for Vulkan.
ghstack-source-id: 262710507
@exported-using-ghexport

Differential Revision: [D68528213](https://our.internmc.facebook.com/intern/diff/D68528213/)

Co-authored-by: Stephen Jia <[email protected]>
(cherry picked from commit 5ee5f2f)

Author: pytorchbot

backends/vulkan/op_registry.py

@@ -228,8 +228,6 @@ def update_features_impl(op: OpKey):
         exir_ops.edge.quantized_decomposed.dequantize_per_tensor.default,
         exir_ops.edge.quantized_decomposed.dequantize_per_tensor.tensor,
         exir_ops.edge.quantized_decomposed.dequantize_per_channel.default,
-        # dim order copy operator will be removed; memory layout is handled internally
-        exir_ops.edge.dim_order_ops._to_dim_order_copy.default,
     ]
 )
 def register_ephemeral_op(features: OpFeatures):
@@ -322,6 +320,37 @@ def check_to_copy_node(node: torch.fx.Node) -> bool:
     return features
 
 
+@update_features(exir_ops.edge.dim_order_ops._to_dim_order_copy.default)
+def register_to_copy_dim_order_op(features: OpFeatures):
+    features.texture_impl = TextureImplFeatures(
+        uses_axis_map=True,
+        valid_packed_dims=all_packed_dims,
+    )
+    features.buffer_impl = True
+    features.resize_fn = True
+
+    # Currently there is no "real" implementation for to_dim_order_copy, but it can be
+    # removed as long as the operator is not changing the dtype, i.e. the operator call
+    # is modifying the dim order only. Therefore, check that the input and output dtypes
+    # are the same, if so the operator is safe to remove.
+    def check_dim_order_copy_node(node: torch.fx.Node) -> bool:
+        in_arg = node.args[0]
+        if not isinstance(in_arg, torch.fx.Node):
+            return False
+
+        in_tensor = in_arg.meta.get("val", None)
+        out_tensor = node.meta.get("val", None)
+
+        if in_tensor.dtype != out_tensor.dtype:
+            return False
+
+        return True
+
+    features.check_node_fn = check_dim_order_copy_node
+
+    return features
+
+
 @update_features(
     [
         exir_ops.edge.aten.bmm.default,