Support Empty Input Tensors and > 5 Cat Inputs

Differential Revision: D68523312

Pull Request resolved: pytorch#7855

backends/xnnpack/_passes/TARGETS

@@ -4,20 +4,7 @@ oncall("executorch")
 
 python_library(
     name = "xnnpack_passes",
-    srcs = [
-        "__init__.py",
-        "channels_last_tagged_reshape_pass.py",
-        "conv1d_unsqueeze_pass.py",
-        "convert_to_linear.py",
-        "convert_to_sdpa.py",
-        "convert_to_upsample_bilinear2d.py",
-        "fuse_activation_pass.py",
-        "fuse_batch_norm_with_conv.py",
-        "prelu_reshape_pass.py",
-        "remove_getitem_op.py",
-        "tag_implicit_q_dq_pass.py",
-        "xnnpack_pass.py",
-    ],
+    srcs = native.glob(["*.py"]),
     deps = [
         "//caffe2:torch",
         "//executorch/backends/transforms:addmm_mm_to_linear",

backends/xnnpack/_passes/__init__.py

@@ -17,6 +17,7 @@
 from executorch.backends.xnnpack._passes.convert_to_upsample_bilinear2d import (
     ConvertToUpsampleBilinear2d,
 )
+from executorch.backends.xnnpack._passes.decompose_cat import DecomposeConcatenate
 from executorch.backends.xnnpack._passes.fuse_activation_pass import FuseActivationPass
 from executorch.backends.xnnpack._passes.fuse_batch_norm_with_conv import (
     FuseBatchNormWithConvPass,
@@ -63,6 +64,7 @@ def __init__(
                 ConstPropPass,
                 FuseBatchNormWithConvPass,
                 FuseActivationPass,
+                DecomposeConcatenate,
                 RemoveGetItemPass,
                 Conv1dUnsqueezePass,
                 PReLUReshapePass,

backends/xnnpack/_passes/decompose_cat.py

@@ -0,0 +1,99 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree.
+
+import logging
+
+import torch
+from executorch.backends.xnnpack.utils.quant_utils import is_dequant, is_quant
+from executorch.exir.dialects._ops import ops as exir_ops
+
+from executorch.exir.pass_base import ExportPass, PassResult
+
+logger = logging.getLogger(__name__)
+logger.setLevel(logging.WARNING)
+
+
+class DecomposeConcatenate(ExportPass):
+    """
+    XNNPACK's Concatenate operation only supports concatenation for <= 5 tensors
+    at a time. As a result, to support concatenates with > 5 tensors, we can decompose
+    concatenates into sequences of cats each with <= 5 tensors.
+
+    Example:
+    Before Pass:
+        cat: "f32" = torch.ops.aten.cat.default([t1, t2, t3, t4, t5, t6], 1);
+
+    After Pass:
+        cat: "f32" = torch.ops.aten.cat.default([t1, t2, t3, t4, t5], 1);
+        cat_1: "f32" = torch.ops.aten.cat.default([cat, t6], 1);
+    """
+
+    def call(self, graph_module: torch.fx.GraphModule):
+        gm = graph_module
+        for node in gm.graph.nodes:
+            if (
+                node.op == "call_function"
+                and node.target.__name__ == "aten.cat.default"
+            ):
+                concat_args = node.args
+                nodes_to_concat = node.args[0]
+                if len(nodes_to_concat) <= 5:
+                    continue
+
+                is_quantized = all(
+                    is_dequant(node) for node in nodes_to_concat
+                ) and all(is_quant(node) for node in node.users.keys())
+
+                # replace the cat args with the same args but only with the first 5 nodes
+                new_concat_args = (nodes_to_concat[:5],) + concat_args[1:]
+                node.args = new_concat_args
+
+                remainder_nodes_to_concat = nodes_to_concat[5:]
+                with gm.graph.inserting_after(node):
+                    logger.debug(f"Decomposing cat node {node}")
+                    remainder_concat_node = gm.graph.create_node(
+                        "call_function",
+                        target=exir_ops.edge.aten.cat.default,
+                        args=([],),  # we will replace this remainder_nodes later
+                        kwargs=node.kwargs,
+                    )
+                    node.replace_all_uses_with(remainder_concat_node)
+                if is_quantized:
+                    # if quantized we need to enforce the q/dq pattern for the newly inserted
+                    # concat node
+                    q_params = nodes_to_concat[0].args[1:]
+                    q_kwargs = nodes_to_concat[0].kwargs
+                    # Quantizer enforces all the inputs and output to a concat node must share
+                    # the same qparams, this means the newly inserted q/dq pair must share the
+                    # same qparams as the first quantized input in the concat node.
+                    with gm.graph.inserting_after(node):
+                        logger.debug(
+                            f"Inserting Q/DQ pair for new cat node {remainder_concat_node}"
+                        )
+                        q_node = gm.graph.create_node(
+                            "call_function",
+                            target=exir_ops.edge.quantized_decomposed.quantize_per_tensor.default,
+                            args=(node,) + q_params,
+                            kwargs=q_kwargs,
+                        )
+                    with gm.graph.inserting_after(q_node):
+                        dq_node = gm.graph.create_node(
+                            "call_function",
+                            target=exir_ops.edge.quantized_decomposed.dequantize_per_tensor.default,
+                            args=(q_node,) + q_params,
+                            kwargs=q_kwargs,
+                        )
+                    remainder_concat_node.args = (
+                        [dq_node] + remainder_nodes_to_concat,
+                    ) + node.args[1:]
+                else:
+                    remainder_concat_node.args = (
+                        [node] + remainder_nodes_to_concat,
+                    ) + node.args[1:]
+
+        gm.recompile()
+        new_gm = super().call(gm).graph_module
+        return PassResult(new_gm, True)

backends/xnnpack/partition/config/generic_node_configs.py

@@ -181,10 +181,10 @@ def check_constraints(self, node: torch.fx.Node, ep: ExportedProgram) -> bool:
 
         num_tensors = len(node.all_input_nodes)
 
-        if not (num_tensors >= 2 and num_tensors <= 5):
+        if not (num_tensors >= 2):
             why(
                 node,
-                reason=f"only support concatenation of 2 - 5 tensors, got {num_tensors} tensors",
+                reason=f"only support concatenation of > 2 tensors, got {num_tensors} tensors",
             )
             return False
 

backends/xnnpack/test/ops/test_cat.py

@@ -14,9 +14,13 @@
 
 class TestCat(unittest.TestCase):
     class Cat(torch.nn.Module):
+        def __init__(self, dim=0):
+            super().__init__()
+            self.dim = dim
+
         def forward(self, *args):
             xs = [*args]
-            x = torch.cat(xs)
+            x = torch.cat(xs, dim=self.dim)
             return x + x  # Quantize by propagation.
 
     def _test_cat(self, module, inputs, cat_num=1, quant=False, quant_ops=2):
@@ -27,7 +31,6 @@ def _test_cat(self, module, inputs, cat_num=1, quant=False, quant_ops=2):
                 tester.quantize()
 
             tester.export().check_count({"torch.ops.aten.cat": 1})
-            tester.dump_artifact()
 
             if quant:
                 # Expect multiple quantize ops - one per input, cat, and add.
@@ -93,6 +96,29 @@ def test_fp16_cat4(self):
         )
         self._test_cat(self.Cat(), inputs)
 
+    def test_fp16_cat5(self):
+        """
+        Using Clamp2 because fp16 add is done in fp32 ATM. Need to fix that first.
+        """
+        inputs = (
+            torch.randn(1, 2, 3).to(torch.float16),
+            torch.randn(3, 2, 3).to(torch.float16),
+            torch.randn(2, 2, 3).to(torch.float16),
+            torch.randn(5, 2, 3).to(torch.float16),
+            torch.randn(5, 2, 3).to(torch.float16),
+        )
+        self._test_cat(self.Cat(), inputs)
+
+    def test_fp16_cat_gt_5(self):
+        """
+        Using Clamp2 because fp16 add is done in fp32 ATM. Need to fix that first.
+        """
+        for num_inputs in range(6, 10):
+            inputs = []
+            for _ in range(num_inputs):
+                inputs.append(torch.randn(1, 2, 3).to(torch.float16))
+            self._test_cat(self.Cat(), tuple(inputs))
+
     def test_fp32_cat2(self):
         inputs = (torch.randn(1, 2, 3), torch.randn(3, 2, 3))
         self._test_cat(self.Cat(), inputs)
@@ -120,6 +146,13 @@ def test_fp32_cat5(self):
         )
         self._test_cat(self.Cat(), inputs)
 
+    def test_fp32_cat_gt_5(self):
+        for num_inputs in range(6, 10):
+            inputs = []
+            for _ in range(num_inputs):
+                inputs.append(torch.randn(1, 2, 3))
+            self._test_cat(self.Cat(), tuple(inputs))
+
     def test_qs8_cat2(self):
         inputs = (torch.randn(1, 2, 3), torch.randn(3, 2, 3))
         self._test_cat(self.Cat(), inputs, cat_num=2, quant=True)
@@ -137,46 +170,22 @@ def test_qs8_cat4(self):
         )
         self._test_cat(self.Cat(), inputs, cat_num=4, quant=True)
 
-    def test_fp32_cat_unsupported(self):
-        """
-        XNNPACK only supports concatenating up to 4 values, so it should not delegate here.
-        """
+    def test_qs8_cat5(self):
         inputs = (
             torch.randn(1, 2, 3),
             torch.randn(3, 2, 3),
             torch.randn(2, 2, 3),
             torch.randn(5, 2, 3),
-            torch.randn(1, 2, 3),
-            torch.randn(2, 2, 3),
-        )
-        (
-            Tester(self.Cat(), inputs)
-            .export()
-            .check_count({"torch.ops.aten.cat": 1})
-            .to_edge_transform_and_lower()
-            .check_count({"executorch_exir_dialects_edge__ops_aten_cat": 1})
-        )
-
-    def test_fp32_cat_unsupported_legacy_mode(self):
-        """
-        XNNPACK only supports concatenating up to 5 values, so it should not delegate here.
-        """
-        inputs = (
-            torch.randn(1, 2, 3),
-            torch.randn(3, 2, 3),
-            torch.randn(2, 2, 3),
             torch.randn(5, 2, 3),
-            torch.randn(1, 2, 3),
-            torch.randn(6, 2, 3),
-        )
-        (
-            Tester(self.Cat(), inputs)
-            .export()
-            .check_count({"torch.ops.aten.cat": 1})
-            .to_edge()
-            .partition()
-            .check_count({"executorch_exir_dialects_edge__ops_aten_cat": 1})
         )
+        self._test_cat(self.Cat(), inputs, cat_num=5, quant=True)
+
+    def test_qs8_cat_gt_5(self):
+        for num_inputs in range(6, 10):
+            inputs = []
+            for _ in range(num_inputs):
+                inputs.append(torch.randn(1, 2, 3))
+            self._test_cat(self.Cat(), tuple(inputs), cat_num=num_inputs, quant=True)
 
     class CatNegativeDim(torch.nn.Module):
         def __init__(self):

backends/xnnpack/test/passes/test_decompose_cat_pass.py

@@ -0,0 +1,109 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the BSD-style license found in the
+# LICENSE file in the root directory of this source tree.
+
+import math
+import unittest
+
+import torch
+from executorch.backends.xnnpack._passes.decompose_cat import DecomposeConcatenate
+from executorch.backends.xnnpack.test.tester import RunPasses, Tester
+
+
+class TestDecomposeCatPass(unittest.TestCase):
+    PassStage = RunPasses([DecomposeConcatenate])
+    cat_name = "executorch_exir_dialects_edge__ops_aten_cat_default"
+
+    class Cat(torch.nn.Module):
+        def forward(self, *args):
+            xs = [*args]
+            x = torch.cat(xs)
+            return x + x  # Quantize by propagation.
+
+    def test_cat_gt_5(self):
+        inputs = [
+            torch.randn(1, 2, 3),
+        ]
+        for num_inputs in range(6, 10):
+            inputs = []
+            for _ in range(num_inputs):
+                inputs.append(torch.randn(1, 2, 3))
+
+            num_cats = int(len(inputs) > 5)
+            num_cats += math.ceil((len(inputs) - 5) / 4)
+            (
+                Tester(self.Cat(), tuple(inputs))
+                .export()
+                .to_edge()
+                .check_count({self.cat_name: 1})
+                .run_passes(self.PassStage)
+                .check_count({self.cat_name: num_cats})
+                .run_method_and_compare_outputs()
+            )
+
+    def test_cat_gt_10(self):
+        inputs = [
+            torch.randn(1, 2, 3),
+        ]
+        for num_inputs in [11, 16, 18]:
+            inputs = []
+            for _ in range(num_inputs):
+                inputs.append(torch.randn(1, 2, 3))
+
+            num_cats = int(len(inputs) > 5)
+            num_cats += math.ceil((len(inputs) - 5) / 4)
+            (
+                Tester(self.Cat(), tuple(inputs))
+                .export()
+                .to_edge()
+                .check_count({self.cat_name: 1})
+                .run_passes(self.PassStage)
+                .check_count({self.cat_name: num_cats})
+                .run_method_and_compare_outputs()
+            )
+
+    def test_qs8_cat_gt_5(self):
+        inputs = [
+            torch.randn(1, 2, 3),
+        ]
+        for num_inputs in range(6, 10):
+            inputs = []
+            for _ in range(num_inputs):
+                inputs.append(torch.randn(1, 2, 3))
+
+            num_cats = int(len(inputs) > 5)
+            num_cats += math.ceil((len(inputs) - 5) / 4)
+            (
+                Tester(self.Cat(), tuple(inputs))
+                .quantize()
+                .export()
+                .to_edge()
+                .check_count({self.cat_name: 1})
+                .run_passes(self.PassStage)
+                .check_count({self.cat_name: num_cats})
+                .run_method_and_compare_outputs()
+            )
+
+    def test_qs8_cat_gt_10(self):
+        inputs = [
+            torch.randn(1, 2, 3),
+        ]
+        for num_inputs in [11, 16, 18]:
+            inputs = []
+            for _ in range(num_inputs):
+                inputs.append(torch.randn(1, 2, 3))
+
+            num_cats = int(len(inputs) > 5)
+            num_cats += math.ceil((len(inputs) - 5) / 4)
+            (
+                Tester(self.Cat(), tuple(inputs))
+                .quantize()
+                .export()
+                .to_edge()
+                .check_count({self.cat_name: 1})
+                .run_passes(self.PassStage)
+                .check_count({self.cat_name: num_cats})
+                .run_method_and_compare_outputs()
+            )