Use quantizable LSTM in test when flow has quantize=True (#14893)

It makes more sense to use the quantizable version of the LSTM. For
example, right now the xnnpack int8 tests pass, even though all tensors
are float, since the quantizer is not triggered.

Signed-off-by: Erik Lundell <[email protected]>

Author: Erik-Lundell

backends/test/suite/operators/test_lstm.py

@@ -1,5 +1,6 @@
 # Copyright (c) Meta Platforms, Inc. and affiliates.
 # All rights reserved.
+# Copyright 2025 Arm Limited and/or its affiliates.
 #
 # This source code is licensed under the BSD-style license found in the
 # LICENSE file in the root directory of this source tree.
@@ -15,6 +16,11 @@
     operator_test,
     OperatorTest,
 )
+from torch.nn.quantizable.modules.rnn import LSTM as QuantizableLSTM
+
+
+def _get_lstm_cls(use_quantizable_lstm: bool):
+    return QuantizableLSTM if use_quantizable_lstm else torch.nn.LSTM
 
 
 class Model(torch.nn.Module):
@@ -27,9 +33,11 @@ def __init__(
         batch_first=True,
         dropout=0.0,
         bidirectional=False,
+        use_quantizable_lstm: bool = False,
     ):
         super().__init__()
-        self.lstm = torch.nn.LSTM(
+        lstm_cls = _get_lstm_cls(use_quantizable_lstm)
+        self.lstm = lstm_cls(
             input_size=input_size,
             hidden_size=hidden_size,
             num_layers=num_layers,
@@ -47,116 +55,144 @@ def forward(self, x):
 class LSTM(OperatorTest):
     @dtype_test
     def test_lstm_dtype(self, flow: TestFlow, dtype) -> None:
+        use_quantizable_lstm = flow.quantize
         self._test_op(
-            Model(num_layers=2).to(dtype),
+            Model(num_layers=2, use_quantizable_lstm=use_quantizable_lstm).to(dtype),
             ((torch.rand(1, 10, 64) * 10).to(dtype),),  # (batch=1, seq_len, input_size)
             flow,
         )
 
     @dtype_test
     def test_lstm_no_bias_dtype(self, flow: TestFlow, dtype) -> None:
+        use_quantizable_lstm = flow.quantize
         self._test_op(
-            Model(num_layers=2, bias=False).to(dtype),
+            Model(
+                num_layers=2, bias=False, use_quantizable_lstm=use_quantizable_lstm
+            ).to(dtype),
             ((torch.rand(1, 10, 64) * 10).to(dtype),),
             flow,
         )
 
     def test_lstm_feature_sizes(self, flow: TestFlow) -> None:
+        use_quantizable_lstm = flow.quantize
         self._test_op(
-            Model(input_size=32, hidden_size=16),
+            Model(
+                input_size=32,
+                hidden_size=16,
+                use_quantizable_lstm=use_quantizable_lstm,
+            ),
             (torch.randn(1, 8, 32),),  # (batch=1, seq_len, input_size)
             flow,
         )
         self._test_op(
-            Model(input_size=128, hidden_size=64),
+            Model(
+                input_size=128,
+                hidden_size=64,
+                use_quantizable_lstm=use_quantizable_lstm,
+            ),
             (torch.randn(1, 12, 128),),
             flow,
         )
         self._test_op(
-            Model(input_size=256, hidden_size=128),
+            Model(
+                input_size=256,
+                hidden_size=128,
+                use_quantizable_lstm=use_quantizable_lstm,
+            ),
             (torch.randn(1, 6, 256),),
             flow,
         )
         self._test_op(
-            Model(input_size=16, hidden_size=32),
+            Model(
+                input_size=16,
+                hidden_size=32,
+                use_quantizable_lstm=use_quantizable_lstm,
+            ),
             (torch.randn(1, 5, 16),),
             flow,
         )
 
     def test_lstm_batch_sizes(self, flow: TestFlow) -> None:
+        use_quantizable_lstm = flow.quantize
         self._test_op(
-            Model(),
+            Model(use_quantizable_lstm=use_quantizable_lstm),
             (torch.randn(8, 10, 64),),
             flow,
         )
         self._test_op(
-            Model(),
+            Model(use_quantizable_lstm=use_quantizable_lstm),
             (torch.randn(32, 10, 64),),
             flow,
         )
         self._test_op(
-            Model(),
+            Model(use_quantizable_lstm=use_quantizable_lstm),
             (torch.randn(100, 10, 64),),
             flow,
         )
 
     def test_lstm_seq_lengths(self, flow: TestFlow) -> None:
+        use_quantizable_lstm = flow.quantize
         self._test_op(
-            Model(),
+            Model(use_quantizable_lstm=use_quantizable_lstm),
             (torch.randn(1, 5, 64),),
             flow,
         )
         self._test_op(
-            Model(),
+            Model(use_quantizable_lstm=use_quantizable_lstm),
             (torch.randn(1, 20, 64),),
             flow,
         )
         self._test_op(
-            Model(),
+            Model(use_quantizable_lstm=use_quantizable_lstm),
             (torch.randn(1, 50, 64),),
             flow,
         )
 
     def test_lstm_batch_first_false(self, flow: TestFlow) -> None:
+        use_quantizable_lstm = flow.quantize
         self._test_op(
-            Model(batch_first=False),
+            Model(batch_first=False, use_quantizable_lstm=use_quantizable_lstm),
             (torch.randn(10, 1, 64),),  # (seq_len, batch=1, input_size)
             flow,
         )
 
     def test_lstm_num_layers(self, flow: TestFlow) -> None:
+        use_quantizable_lstm = flow.quantize
         self._test_op(
-            Model(num_layers=2),
+            Model(num_layers=2, use_quantizable_lstm=use_quantizable_lstm),
             (torch.randn(1, 10, 64),),
             flow,
         )
         self._test_op(
-            Model(num_layers=3),
+            Model(num_layers=3, use_quantizable_lstm=use_quantizable_lstm),
             (torch.randn(1, 10, 64),),
             flow,
         )
 
     def test_lstm_bidirectional(self, flow: TestFlow) -> None:
+        use_quantizable_lstm = flow.quantize
         self._test_op(
-            Model(bidirectional=True),
+            Model(bidirectional=True, use_quantizable_lstm=use_quantizable_lstm),
             (torch.randn(1, 10, 64),),
             flow,
         )
 
     def test_lstm_with_dropout(self, flow: TestFlow) -> None:
         # Note: Dropout is only effective with num_layers > 1
+        use_quantizable_lstm = flow.quantize
         self._test_op(
-            Model(num_layers=2, dropout=0.2),
+            Model(num_layers=2, dropout=0.2, use_quantizable_lstm=use_quantizable_lstm),
             (torch.randn(1, 10, 64),),
             flow,
         )
 
     def test_lstm_with_initial_states(self, flow: TestFlow) -> None:
         # Create a model that accepts initial states
         class ModelWithStates(torch.nn.Module):
-            def __init__(self):
+            def __init__(self, use_quantizable_lstm: bool = False):
                 super().__init__()
-                self.lstm = torch.nn.LSTM(
+                lstm_cls = _get_lstm_cls(use_quantizable_lstm)
+                self.lstm = lstm_cls(
                     input_size=64,
                     hidden_size=32,
                     num_layers=2,
@@ -169,9 +205,10 @@ def forward(self, x, h0, c0):
         batch_size = 1
         num_layers = 2
         hidden_size = 32
+        use_quantizable_lstm = flow.quantize
 
         self._test_op(
-            ModelWithStates(),
+            ModelWithStates(use_quantizable_lstm=use_quantizable_lstm),
             (
                 torch.randn(batch_size, 10, 64),  # input
                 torch.randn(num_layers, batch_size, hidden_size),  # h0
@@ -183,9 +220,10 @@ def forward(self, x, h0, c0):
     def test_lstm_return_hidden_states(self, flow: TestFlow) -> None:
         # Create a model that returns both output and hidden states
         class ModelWithHiddenStates(torch.nn.Module):
-            def __init__(self):
+            def __init__(self, use_quantizable_lstm: bool = False):
                 super().__init__()
-                self.lstm = torch.nn.LSTM(
+                lstm_cls = _get_lstm_cls(use_quantizable_lstm)
+                self.lstm = lstm_cls(
                     input_size=64,
                     hidden_size=32,
                     num_layers=2,
@@ -200,9 +238,10 @@ def forward(self, x):
         batch_size = 1
         seq_len = 10
         input_size = 64
+        use_quantizable_lstm = flow.quantize
 
         self._test_op(
-            ModelWithHiddenStates(),
+            ModelWithHiddenStates(use_quantizable_lstm=use_quantizable_lstm),
             (torch.randn(batch_size, seq_len, input_size),),
             flow,
         )