Qualcomm AI Engine Direct - support dim_order (#7189)

Summary
- remove _to_dim op and let backend take care of tensor layout
- test cases

Author: haowhsu-quic

backends/qualcomm/_passes/remove_redundancy.py

@@ -11,7 +11,7 @@
 
 class RemoveRedundancy(ExportPass):
     """
-    Trim the 'identity' operators to reduce the unnecessary copy overhead.
+    Trim certain operators to reduce unnecessary overhead.
     """
 
     redundant_ops = {
@@ -21,6 +21,10 @@ class RemoveRedundancy(ExportPass):
         torch.ops.aten.alias.default,
         exir_ops.edge.aten.alias.default,
         exir_ops.edge.aten.lift_fresh_copy.default,
+        # remove this target if '_skip_dim_order' is set to False
+        exir_ops.edge.dim_order_ops._to_dim_order_copy.default,
+        # remove channel_last / contiguous _to_copy if '_skip_dim_order' is set to True
+        exir_ops.edge.aten._to_copy.default,
     }
 
     def __init__(self):
@@ -31,6 +35,13 @@ def _remove(self, graph_module: torch.fx.GraphModule) -> torch.fx.GraphModule:
             if n.target not in self.redundant_ops:
                 continue
 
+            # do not remove cast operator
+            if (
+                n.target == exir_ops.edge.aten._to_copy.default
+                and "memory_format" not in n.kwargs
+            ):
+                continue
+
             to_be_remove = n
             for user_n in list(n.users.keys()):
                 user_n.replace_input_with(n, n.args[0])

backends/qualcomm/tests/models.py

@@ -325,7 +325,7 @@ def forward(self, x):
 
 
 class Conv2dSequential(torch.nn.Module):
-    def __init__(self, bias=True):
+    def __init__(self, bias=True, channel_last=False):
         super().__init__()
         self.first = torch.nn.Conv2d(
             in_channels=1,
@@ -341,8 +341,10 @@ def __init__(self, bias=True):
             padding=1,
             bias=bias,
         )
+        self.channel_last = channel_last
 
     def forward(self, x):
+        x = x.to(memory_format=torch.channels_last) if self.channel_last else x
         return self.second(self.first(x))
 
 

backends/qualcomm/tests/test_qnn_delegate.py

@@ -133,6 +133,16 @@ def test_qnn_backend_conv2d(self):
             with self.subTest(i=i):
                 self.lower_module_and_test_output(module, sample_input)
 
+    def test_qnn_backend_conv2d_channel_last(self):
+        modules = [
+            Conv2dSequential(channel_last=True),  # noqa: F405
+            Conv2dSequential(bias=False, channel_last=True),  # noqa: F405
+        ]
+        sample_input = (torch.randn([1, 1, 3, 3]),)
+        for i, module in enumerate(modules):
+            with self.subTest(i=i):
+                self.lower_module_and_test_output(module, sample_input)
+
     def test_qnn_backend_conv_transpose2d(self):
         modules = [
             ConvTranspose2dSingle(),  # noqa: F405
@@ -824,6 +834,17 @@ def test_qnn_backend_conv2d(self):
                 module = self.get_qdq_module(module, sample_input)
                 self.lower_module_and_test_output(module, sample_input)
 
+    def test_qnn_backend_conv2d_channel_last(self):
+        modules = [
+            Conv2dSequential(channel_last=True),  # noqa: F405
+            Conv2dSequential(bias=False, channel_last=True),  # noqa: F405
+        ]
+        sample_input = (torch.randn([1, 1, 3, 3]),)
+        for i, module in enumerate(modules):
+            with self.subTest(i=i):
+                module = self.get_qdq_module(module, sample_input)
+                self.lower_module_and_test_output(module, sample_input)
+
     def test_qnn_backend_conv_transpose2d(self):
         modules = [
             ConvTranspose2dSingle(),  # noqa: F405

backends/qualcomm/utils/utils.py

@@ -166,7 +166,6 @@ def qnn_capture_config():
 def qnn_edge_config() -> exir.EdgeCompileConfig:
     return exir.EdgeCompileConfig(
         _check_ir_validity=False,
-        _skip_dim_order=True,  # TODO(T182928844): Delegate dim order op to backend.
     )