Support ceil_mode=True on maxpool2d in XNNPACK delegate

backends/xnnpack/operators/op_max_pool2d.py

@@ -4,6 +4,8 @@
 # This source code is licensed under the BSD-style license found in the
 # LICENSE file in the root directory of this source tree.
 
+# pyre-unsafe
+
 from typing import cast, Dict, List
 
 import torch
@@ -51,9 +53,9 @@ def define_node(
         kwargs["output_id"] = vals_to_ids[node]
 
         # kernel info
-        kernal_shape = cast(List[int], node.args[1])
-        kwargs["pooling_height"] = kernal_shape[0]
-        kwargs["pooling_width"] = kernal_shape[1]
+        kernel_shape = cast(List[int], node.args[1])
+        kwargs["pooling_height"] = kernel_shape[0]
+        kwargs["pooling_width"] = kernel_shape[1]
 
         # stride info
         stride = cast(List[int], node.args[2])
@@ -81,6 +83,26 @@ def define_node(
             kwargs["dilation_height"] = dilation[0]
             kwargs["dilation_width"] = dilation[1]
 
+        # ceil mode
+        ceil_mode = node.args[5] if len(node.args) > 5 else False
+        if ceil_mode:
+            # use original input shape as xnnpack input may be permuted
+            orig_input_shape = node.all_input_nodes[0].meta["val"].shape
+            kwargs["padding_bottom"] += self.calculate_pad_amount_1d(
+                orig_input_shape[2],
+                kernel_shape[0],
+                stride[0],
+                padding_shape[0],
+                dilation[0],
+            )
+            kwargs["padding_right"] += self.calculate_pad_amount_1d(
+                orig_input_shape[3],
+                kernel_shape[1],
+                stride[1],
+                padding_shape[1],
+                dilation[1],
+            )
+
         kwargs["flags"] = XNN_FLAG_KEEP_DIMS
 
         ser_node = XNode(
@@ -90,3 +112,25 @@ def define_node(
             debug_handle=debug_handle,
         )
         xnn_graph.xnodes.append(ser_node)
+
+    def calculate_pad_amount_1d(self, in_size, kernel_size, stride, padding, dilation):
+        # Determine the number of padding elements to add along a single dimension
+        # to match the ceil_mode=True behavior.
+        # See https://pytorch.org/docs/stable/generated/torch.nn.MaxPool1d.html
+
+        # Determine the number of input elements to exactly bump up the output size
+        # by 1. Note that there is an additional condition to substract 1 from the
+        # output when ceil_mode=True and (output_size - 1) * stride >= in_size + padding
+        # In this case, we don't need to pad, as ceil_mode=False and True give the
+        # same behavior.
+        numerator_no_ceil = in_size + 2 * padding - dilation * (kernel_size - 1) - 1
+        numerator = numerator_no_ceil + stride - 1
+        output_size = numerator // stride + 1
+
+        needs_adjust = (output_size - 1) * stride >= in_size + padding
+        partial_stride = numerator_no_ceil % stride
+        pad_out = (
+            (stride - partial_stride) if partial_stride > 0 and not needs_adjust else 0
+        )
+
+        return pad_out

backends/xnnpack/partition/config/generic_node_configs.py

@@ -4,6 +4,8 @@
 # This source code is licensed under the BSD-style license found in the
 # LICENSE file in the root directory of this source tree.
 
+# pyre-unsafe
+
 import logging
 from typing import cast, List, Optional
 
@@ -287,9 +289,13 @@ def check_constraints(self, node: torch.fx.Node, ep: ExportedProgram) -> bool:
         if not self.check_common_constraints(node, ep):
             return False
 
+        # Ceil mode is supported via op padding, which must be statically known.
         is_ceil_mode = len(node.args) >= 6 and cast(bool, node.args[5])
-        if is_ceil_mode:
-            why(node, reason="ceil mode is not supported")
+        is_dynamic = "val" in node.meta and any(
+            isinstance(d, torch.SymInt) for d in node.meta["val"].shape
+        )
+        if is_ceil_mode and is_dynamic:
+            why(node, reason="ceil mode is not supported for dynamic shapes")
             return False
         return True
 

backends/xnnpack/test/ops/test_maxpool2d.py

@@ -4,10 +4,14 @@
 # This source code is licensed under the BSD-style license found in the
 # LICENSE file in the root directory of this source tree.
 
+# pyre-unsafe
+
+import itertools
 import unittest
 
 import torch
-from executorch.backends.xnnpack.test.tester import Tester
+from executorch.backends.xnnpack.test.tester import Export, Tester
+from torch.export.dynamic_shapes import Dim
 
 
 class TestMaxPool2d(unittest.TestCase):
@@ -38,10 +42,12 @@ def __init__(self, kernel_size=3, stride=1, padding=0, dilation=1):
         def forward(self, x):
             return self.max_pool2d_module(x)[1]
 
-    class MaxPool2dUnsupportedCeilMode(torch.nn.Module):
-        def __init__(self):
+    class MaxPool2dCeilMode(torch.nn.Module):
+        def __init__(self, kernel_size=3, stride=1, padding=0, dilation=1):
             super().__init__()
-            self.max_pool2d_module = torch.nn.MaxPool2d(2, stride=2, ceil_mode=True)
+            self.max_pool2d_module = torch.nn.MaxPool2d(
+                kernel_size, stride, padding, dilation, ceil_mode=True
+            )
 
         def forward(self, x):
             return self.max_pool2d_module(x)
@@ -93,14 +99,56 @@ def test_fp32_maxpool2d_unsupported(self):
             )
         )
 
-    def test_fp32_maxpool2d_unsupported_ceilmode(self):
+    def test_fp32_maxpool2d_ceilmode(self):
+        input_sizes = [[17, 32], [32, 37]]
+        kernel_sizes = [2, 3, 12]
+        strides = [1, 2, 4]
+        padding = [0, 1, 5]
+        dilations = [1, 2, 3]
+
+        for input_size, kernel_size, stride, pad, dilation in itertools.product(
+            input_sizes, kernel_sizes, strides, padding, dilations
+        ):
+            # Check XNNPACK and PyTorch constraints
+            if pad > ((kernel_size - 1) * dilation + 1) / 2:
+                continue
+            if stride > kernel_size:
+                continue
+            if any(
+                (size + 2 * pad - dilation * (kernel_size - 1) - 1) // stride + 1 <= 0
+                for size in input_size
+            ):  # Output size too small
+                continue
+
+            inputs = (torch.randn(1, 1, input_size[0], input_size[1]),)
+            (
+                Tester(
+                    self.MaxPool2dCeilMode(kernel_size, stride, pad, dilation), inputs
+                )
+                .export()
+                .check_count({"torch.ops.aten.max_pool2d.default": 1})
+                .to_edge_transform_and_lower()
+                .check_count({"torch.ops.higher_order.executorch_call_delegate": 1})
+                .check_not(
+                    [
+                        "executorch_exir_dialects_edge__ops_aten_max_pool2d_with_indices_default"
+                    ]
+                )
+                .to_executorch()
+                .serialize()
+                .run_method_and_compare_outputs()
+            )
+
+    def test_fp32_maxpool2d_unsupported_dynamic_ceilmode(self):
         """
-        MaxPool2d with ceil mode is not generally supported (see maxpool2d constraint).
+        MaxPool2d with ceil mode is supported with dynamic shape (see maxpool2d constraint).
         """
         inputs = (torch.randn(1, 32, 23, 23),)
+        dim3 = Dim("_dim3", min=11, max=50)
+        dynamic_shapes = {"x": {3: 2 * dim3 - 1}}
         (
-            Tester(self.MaxPool2dUnsupportedCeilMode(), inputs)
-            .export()
+            Tester(self.MaxPool2dCeilMode(), inputs)
+            .export(Export(dynamic_shapes=dynamic_shapes))
             .check_count({"torch.ops.aten.max_pool2d.default": 1})
             .to_edge_transform_and_lower()
             # We expect it not be be delegated.