Add TF<>PT and Flax<>PT everywhere (#14047)

* up

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* add clip

* fix clip PyTorch

* fix clip PyTorch

* up

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src/transformers/models/albert/modeling_flax_albert.py

@@ -314,35 +314,13 @@ class FlaxAlbertLayer(nn.Module):
         return outputs
 
 
-class FlaxAlbertLayers(nn.Module):
-    config: AlbertConfig
-    dtype: jnp.dtype = jnp.float32  # the dtype of the computation
-    layer_index: Optional[str] = None
-
-    def setup(self):
-        self.albert_layers = FlaxAlbertLayer(self.config, name=self.layer_index, dtype=self.dtype)
-
-    def __call__(
-        self,
-        hidden_states,
-        attention_mask,
-        deterministic: bool = True,
-        output_attentions: bool = False,
-    ):
-        outputs = self.albert_layers(
-            hidden_states, attention_mask, deterministic=deterministic, output_attentions=output_attentions
-        )
-        return outputs
-
-
 class FlaxAlbertLayerCollection(nn.Module):
     config: AlbertConfig
     dtype: jnp.dtype = jnp.float32  # the dtype of the computation
 
     def setup(self):
         self.layers = [
-            FlaxAlbertLayers(self.config, name="albert_layers", layer_index=str(i), dtype=self.dtype)
-            for i in range(self.config.inner_group_num)
+            FlaxAlbertLayer(self.config, name=str(i), dtype=self.dtype) for i in range(self.config.inner_group_num)
         ]
 
     def __call__(
@@ -385,7 +363,7 @@ class FlaxAlbertLayerCollections(nn.Module):
     layer_index: Optional[str] = None
 
     def setup(self):
-        self.albert_layer_groups = FlaxAlbertLayerCollection(self.config, name=self.layer_index, dtype=self.dtype)
+        self.albert_layers = FlaxAlbertLayerCollection(self.config, dtype=self.dtype)
 
     def __call__(
         self,
@@ -395,7 +373,7 @@ class FlaxAlbertLayerCollections(nn.Module):
         output_attentions: bool = False,
         output_hidden_states: bool = False,
     ):
-        outputs = self.albert_layer_groups(
+        outputs = self.albert_layers(
             hidden_states,
             attention_mask,
             deterministic=deterministic,
@@ -405,19 +383,13 @@ class FlaxAlbertLayerCollections(nn.Module):
         return outputs
 
 
-class FlaxAlbertEncoder(nn.Module):
+class FlaxAlbertLayerGroups(nn.Module):
     config: AlbertConfig
     dtype: jnp.dtype = jnp.float32  # the dtype of the computation
 
     def setup(self):
-        self.layers_per_group = int(self.config.num_hidden_layers / self.config.num_hidden_groups)
-        self.embedding_hidden_mapping_in = nn.Dense(
-            self.config.hidden_size,
-            kernel_init=jax.nn.initializers.normal(self.config.initializer_range, self.dtype),
-            dtype=self.dtype,
-        )
         self.layers = [
-            FlaxAlbertLayerCollections(self.config, name="albert_layer_groups", layer_index=str(i), dtype=self.dtype)
+            FlaxAlbertLayerCollections(self.config, name=str(i), layer_index=str(i), dtype=self.dtype)
             for i in range(self.config.num_hidden_groups)
         ]
 
@@ -430,7 +402,6 @@ class FlaxAlbertEncoder(nn.Module):
         output_hidden_states: bool = False,
         return_dict: bool = True,
     ):
-        hidden_states = self.embedding_hidden_mapping_in(hidden_states)
         all_attentions = () if output_attentions else None
         all_hidden_states = (hidden_states,) if output_hidden_states else None
 
@@ -459,6 +430,37 @@ class FlaxAlbertEncoder(nn.Module):
         )
 
 
+class FlaxAlbertEncoder(nn.Module):
+    config: AlbertConfig
+    dtype: jnp.dtype = jnp.float32  # the dtype of the computation
+
+    def setup(self):
+        self.embedding_hidden_mapping_in = nn.Dense(
+            self.config.hidden_size,
+            kernel_init=jax.nn.initializers.normal(self.config.initializer_range, self.dtype),
+            dtype=self.dtype,
+        )
+        self.albert_layer_groups = FlaxAlbertLayerGroups(self.config, dtype=self.dtype)
+
+    def __call__(
+        self,
+        hidden_states,
+        attention_mask,
+        deterministic: bool = True,
+        output_attentions: bool = False,
+        output_hidden_states: bool = False,
+        return_dict: bool = True,
+    ):
+        hidden_states = self.embedding_hidden_mapping_in(hidden_states)
+        return self.albert_layer_groups(
+            hidden_states,
+            attention_mask,
+            deterministic=deterministic,
+            output_attentions=output_attentions,
+            output_hidden_states=output_hidden_states,
+        )
+
+
 class FlaxAlbertOnlyMLMHead(nn.Module):
     config: AlbertConfig
     dtype: jnp.dtype = jnp.float32

src/transformers/models/hubert/modeling_tf_hubert.py

@@ -1222,7 +1222,10 @@ class TFHubertMainLayer(tf.keras.layers.Layer):
         if inputs["attention_mask"] is not None:
             # compute real output lengths according to convolution formula
             output_lengths = self._get_feat_extract_output_lengths(tf.reduce_sum(inputs["attention_mask"], -1))
-            attention_mask = tf.sequence_mask(output_lengths, dtype=hidden_states.dtype)
+
+            attention_mask = tf.sequence_mask(
+                output_lengths, maxlen=shape_list(hidden_states)[1], dtype=hidden_states.dtype
+            )
 
         hidden_states = self.feature_projection(hidden_states, training=inputs["training"])
 

tests/test_modeling_big_bird.py

@@ -59,7 +59,7 @@ class BigBirdModelTester:
         num_hidden_layers=2,
         num_attention_heads=4,
         intermediate_size=37,
-        hidden_act="gelu_fast",
+        hidden_act="gelu_new",
         hidden_dropout_prob=0.1,
         attention_probs_dropout_prob=0.1,
         max_position_embeddings=256,

tests/test_modeling_clip.py

@@ -23,9 +23,17 @@ import unittest
 import numpy as np
 
 import requests
+import transformers
 from transformers import CLIPConfig, CLIPTextConfig, CLIPVisionConfig
 from transformers.file_utils import is_torch_available, is_vision_available
-from transformers.testing_utils import require_torch, require_vision, slow, torch_device
+from transformers.testing_utils import (
+    is_flax_available,
+    is_pt_flax_cross_test,
+    require_torch,
+    require_vision,
+    slow,
+    torch_device,
+)
 
 from .test_configuration_common import ConfigTester
 from .test_modeling_common import ModelTesterMixin, _config_zero_init, floats_tensor, ids_tensor, random_attention_mask
@@ -45,6 +53,14 @@ if is_vision_available():
     from transformers import CLIPProcessor
 
 
+if is_flax_available():
+    import jax.numpy as jnp
+    from transformers.modeling_flax_pytorch_utils import (
+        convert_pytorch_state_dict_to_flax,
+        load_flax_weights_in_pytorch_model,
+    )
+
+
 class CLIPVisionModelTester:
     def __init__(
         self,
@@ -330,6 +346,13 @@ class CLIPTextModelTester:
         if self.use_input_mask:
             input_mask = random_attention_mask([self.batch_size, self.seq_length])
 
+        if input_mask is not None:
+            batch_size, seq_length = input_mask.shape
+            rnd_start_indices = np.random.randint(1, seq_length - 1, size=(batch_size,))
+            for batch_idx, start_index in enumerate(rnd_start_indices):
+                input_mask[batch_idx, :start_index] = 1
+                input_mask[batch_idx, start_index:] = 0
+
         config = self.get_config()
 
         return config, input_ids, input_mask
@@ -558,6 +581,125 @@ class CLIPModelTest(ModelTesterMixin, unittest.TestCase):
 
             self.assertTrue(models_equal)
 
+    # overwrite from common since FlaxCLIPModel returns nested output
+    # which is not supported in the common test
+    @is_pt_flax_cross_test
+    def test_equivalence_pt_to_flax(self):
+        config, inputs_dict = self.model_tester.prepare_config_and_inputs_for_common()
+
+        for model_class in self.all_model_classes:
+            with self.subTest(model_class.__name__):
+
+                # load PyTorch class
+                pt_model = model_class(config).eval()
+                # Flax models don't use the `use_cache` option and cache is not returned as a default.
+                # So we disable `use_cache` here for PyTorch model.
+                pt_model.config.use_cache = False
+
+                fx_model_class_name = "Flax" + model_class.__name__
+
+                if not hasattr(transformers, fx_model_class_name):
+                    return
+
+                fx_model_class = getattr(transformers, fx_model_class_name)
+
+                # load Flax class
+                fx_model = fx_model_class(config, dtype=jnp.float32)
+                # make sure only flax inputs are forward that actually exist in function args
+                fx_input_keys = inspect.signature(fx_model.__call__).parameters.keys()
+
+                # prepare inputs
+                pt_inputs = self._prepare_for_class(inputs_dict, model_class)
+
+                # remove function args that don't exist in Flax
+                pt_inputs = {k: v for k, v in pt_inputs.items() if k in fx_input_keys}
+
+                fx_state = convert_pytorch_state_dict_to_flax(pt_model.state_dict(), fx_model)
+                fx_model.params = fx_state
+
+                with torch.no_grad():
+                    pt_outputs = pt_model(**pt_inputs).to_tuple()
+
+                # convert inputs to Flax
+                fx_inputs = {k: np.array(v) for k, v in pt_inputs.items() if torch.is_tensor(v)}
+                fx_outputs = fx_model(**fx_inputs).to_tuple()
+                self.assertEqual(len(fx_outputs), len(pt_outputs), "Output lengths differ between Flax and PyTorch")
+                for fx_output, pt_output in zip(fx_outputs[:4], pt_outputs[:4]):
+                    self.assert_almost_equals(fx_output, pt_output.numpy(), 4e-2)
+
+                with tempfile.TemporaryDirectory() as tmpdirname:
+                    pt_model.save_pretrained(tmpdirname)
+                    fx_model_loaded = fx_model_class.from_pretrained(tmpdirname, from_pt=True)
+
+                fx_outputs_loaded = fx_model_loaded(**fx_inputs).to_tuple()
+                self.assertEqual(
+                    len(fx_outputs_loaded), len(pt_outputs), "Output lengths differ between Flax and PyTorch"
+                )
+                for fx_output_loaded, pt_output in zip(fx_outputs_loaded[:4], pt_outputs[:4]):
+                    self.assert_almost_equals(fx_output_loaded, pt_output.numpy(), 4e-2)
+
+    # overwrite from common since FlaxCLIPModel returns nested output
+    # which is not supported in the common test
+    @is_pt_flax_cross_test
+    def test_equivalence_flax_to_pt(self):
+        config, inputs_dict = self.model_tester.prepare_config_and_inputs_for_common()
+
+        for model_class in self.all_model_classes:
+            with self.subTest(model_class.__name__):
+                # load corresponding PyTorch class
+                pt_model = model_class(config).eval()
+
+                # So we disable `use_cache` here for PyTorch model.
+                pt_model.config.use_cache = False
+
+                fx_model_class_name = "Flax" + model_class.__name__
+
+                if not hasattr(transformers, fx_model_class_name):
+                    # no flax model exists for this class
+                    return
+
+                fx_model_class = getattr(transformers, fx_model_class_name)
+
+                # load Flax class
+                fx_model = fx_model_class(config, dtype=jnp.float32)
+                # make sure only flax inputs are forward that actually exist in function args
+                fx_input_keys = inspect.signature(fx_model.__call__).parameters.keys()
+
+                pt_model = load_flax_weights_in_pytorch_model(pt_model, fx_model.params)
+
+                # make sure weights are tied in PyTorch
+                pt_model.tie_weights()
+
+                # prepare inputs
+                pt_inputs = self._prepare_for_class(inputs_dict, model_class)
+
+                # remove function args that don't exist in Flax
+                pt_inputs = {k: v for k, v in pt_inputs.items() if k in fx_input_keys}
+
+                with torch.no_grad():
+                    pt_outputs = pt_model(**pt_inputs).to_tuple()
+
+                fx_inputs = {k: np.array(v) for k, v in pt_inputs.items() if torch.is_tensor(v)}
+
+                fx_outputs = fx_model(**fx_inputs).to_tuple()
+                self.assertEqual(len(fx_outputs), len(pt_outputs), "Output lengths differ between Flax and PyTorch")
+
+                for fx_output, pt_output in zip(fx_outputs[:4], pt_outputs[:4]):
+                    self.assert_almost_equals(fx_output, pt_output.numpy(), 4e-2)
+
+                with tempfile.TemporaryDirectory() as tmpdirname:
+                    fx_model.save_pretrained(tmpdirname)
+                    pt_model_loaded = model_class.from_pretrained(tmpdirname, from_flax=True)
+
+                with torch.no_grad():
+                    pt_outputs_loaded = pt_model_loaded(**pt_inputs).to_tuple()
+
+                self.assertEqual(
+                    len(fx_outputs), len(pt_outputs_loaded), "Output lengths differ between Flax and PyTorch"
+                )
+                for fx_output, pt_output in zip(fx_outputs[:4], pt_outputs_loaded[:4]):
+                    self.assert_almost_equals(fx_output, pt_output.numpy(), 4e-2)
+
     @slow
     def test_model_from_pretrained(self):
         for model_name in CLIP_PRETRAINED_MODEL_ARCHIVE_LIST[:1]:

tests/test_modeling_common.py

@@ -25,10 +25,13 @@ import unittest
 import warnings
 from typing import Dict, List, Tuple
 
+import numpy as np
+
+import transformers
 from huggingface_hub import HfApi, Repository
 from requests.exceptions import HTTPError
 from transformers import AutoModel, AutoModelForSequenceClassification, is_torch_available, logging
-from transformers.file_utils import WEIGHTS_NAME, is_torch_fx_available
+from transformers.file_utils import WEIGHTS_NAME, is_flax_available, is_torch_fx_available
 from transformers.models.auto import get_values
 from transformers.testing_utils import (
     ENDPOINT_STAGING,
@@ -36,6 +39,8 @@ from transformers.testing_utils import (
     USER,
     CaptureLogger,
     TestCasePlus,
+    is_pt_flax_cross_test,
+    is_pt_tf_cross_test,
     is_staging_test,
     require_torch,
     require_torch_multi_gpu,
@@ -45,7 +50,6 @@ from transformers.testing_utils import (
 
 
 if is_torch_available():
-    import numpy as np
     import torch
     from torch import nn
 
@@ -70,6 +74,13 @@ if is_torch_available():
         T5ForConditionalGeneration,
     )
 
+if is_flax_available():
+    import jax.numpy as jnp
+    from transformers.modeling_flax_pytorch_utils import (
+        convert_pytorch_state_dict_to_flax,
+        load_flax_weights_in_pytorch_model,
+    )
+
 if is_torch_fx_available():
     from transformers.utils.fx import symbolic_trace
 
@@ -1417,6 +1428,241 @@ class ModelTesterMixin:
                 model, tuple_inputs, dict_inputs, {"output_hidden_states": True, "output_attentions": True}
             )
 
+    @is_pt_tf_cross_test
+    def test_pt_tf_model_equivalence(self):
+        import numpy as np
+        import tensorflow as tf
+
+        import transformers
+
+        config, inputs_dict = self.model_tester.prepare_config_and_inputs_for_common()
+
+        for model_class in self.all_model_classes:
+            tf_model_class_name = "TF" + model_class.__name__  # Add the "TF" at the beginning
+
+            if not hasattr(transformers, tf_model_class_name):
+                # transformers does not have TF version yet
+                return
+
+            tf_model_class = getattr(transformers, tf_model_class_name)
+
+            config.output_hidden_states = True
+
+            tf_model = tf_model_class(config)
+            pt_model = model_class(config)
+
+            # make sure only tf inputs are forward that actually exist in function args
+            tf_input_keys = set(inspect.signature(tf_model.call).parameters.keys())
+
+            # remove all head masks
+            tf_input_keys.discard("head_mask")
+            tf_input_keys.discard("cross_attn_head_mask")
+            tf_input_keys.discard("decoder_head_mask")
+
+            pt_inputs = self._prepare_for_class(inputs_dict, model_class)
+            pt_inputs = {k: v for k, v in pt_inputs.items() if k in tf_input_keys}
+
+            # Check predictions on first output (logits/hidden-states) are close enought given low-level computational differences
+            pt_model.eval()
+            tf_inputs_dict = {}
+            for key, tensor in pt_inputs.items():
+                # skip key that does not exist in tf
+                if type(tensor) == bool:
+                    tf_inputs_dict[key] = tensor
+                elif key == "input_values":
+                    tf_inputs_dict[key] = tf.convert_to_tensor(tensor.numpy(), dtype=tf.float32)
+                else:
+                    tf_inputs_dict[key] = tf.convert_to_tensor(tensor.numpy(), dtype=tf.int32)
+
+            # Check we can load pt model in tf and vice-versa with model => model functions
+            tf_model = transformers.load_pytorch_model_in_tf2_model(tf_model, pt_model, tf_inputs=tf_inputs_dict)
+            pt_model = transformers.load_tf2_model_in_pytorch_model(pt_model, tf_model)
+
+            # need to rename encoder-decoder "inputs" for PyTorch
+            #            if "inputs" in pt_inputs_dict and self.is_encoder_decoder:
+            #                pt_inputs_dict["input_ids"] = pt_inputs_dict.pop("inputs")
+
+            with torch.no_grad():
+                pto = pt_model(**pt_inputs)
+            tfo = tf_model(tf_inputs_dict, training=False)
+
+            tf_hidden_states = tfo[0].numpy()
+            pt_hidden_states = pto[0].numpy()
+
+            tf_nans = np.copy(np.isnan(tf_hidden_states))
+            pt_nans = np.copy(np.isnan(pt_hidden_states))
+
+            pt_hidden_states[tf_nans] = 0
+            tf_hidden_states[tf_nans] = 0
+            pt_hidden_states[pt_nans] = 0
+            tf_hidden_states[pt_nans] = 0
+
+            max_diff = np.amax(np.abs(tf_hidden_states - pt_hidden_states))
+            self.assertLessEqual(max_diff, 4e-2)
+
+            # Check we can load pt model in tf and vice-versa with checkpoint => model functions
+            with tempfile.TemporaryDirectory() as tmpdirname:
+                pt_checkpoint_path = os.path.join(tmpdirname, "pt_model.bin")
+                torch.save(pt_model.state_dict(), pt_checkpoint_path)
+                tf_model = transformers.load_pytorch_checkpoint_in_tf2_model(tf_model, pt_checkpoint_path)
+
+                tf_checkpoint_path = os.path.join(tmpdirname, "tf_model.h5")
+                tf_model.save_weights(tf_checkpoint_path)
+                pt_model = transformers.load_tf2_checkpoint_in_pytorch_model(pt_model, tf_checkpoint_path)
+
+            # Check predictions on first output (logits/hidden-states) are close enought given low-level computational differences
+            pt_model.eval()
+            tf_inputs_dict = {}
+            for key, tensor in pt_inputs.items():
+                # skip key that does not exist in tf
+                if type(tensor) == bool:
+                    tensor = np.array(tensor, dtype=bool)
+                    tf_inputs_dict[key] = tf.convert_to_tensor(tensor, dtype=tf.int32)
+                elif key == "input_values":
+                    tf_inputs_dict[key] = tf.convert_to_tensor(tensor.numpy(), dtype=tf.float32)
+                else:
+                    tf_inputs_dict[key] = tf.convert_to_tensor(tensor.numpy(), dtype=tf.int32)
+
+            # need to rename encoder-decoder "inputs" for PyTorch
+            #            if "inputs" in pt_inputs_dict and self.is_encoder_decoder:
+            #                pt_inputs_dict["input_ids"] = pt_inputs_dict.pop("inputs")
+
+            with torch.no_grad():
+                pto = pt_model(**pt_inputs)
+
+            tfo = tf_model(tf_inputs_dict)
+            tfo = tfo[0].numpy()
+            pto = pto[0].numpy()
+            tf_nans = np.copy(np.isnan(tfo))
+            pt_nans = np.copy(np.isnan(pto))
+
+            pto[tf_nans] = 0
+            tfo[tf_nans] = 0
+            pto[pt_nans] = 0
+            tfo[pt_nans] = 0
+
+            max_diff = np.amax(np.abs(tfo - pto))
+            self.assertLessEqual(max_diff, 4e-2)
+
+    def assert_almost_equals(self, a: np.ndarray, b: np.ndarray, tol: float):
+        diff = np.abs((a - b)).max()
+        self.assertLessEqual(diff, tol, f"Difference between torch and flax is {diff} (>= {tol}).")
+
+    @is_pt_flax_cross_test
+    def test_equivalence_pt_to_flax(self):
+        config, inputs_dict = self.model_tester.prepare_config_and_inputs_for_common()
+
+        for model_class in self.all_model_classes:
+            with self.subTest(model_class.__name__):
+
+                # load PyTorch class
+                pt_model = model_class(config).eval()
+                # Flax models don't use the `use_cache` option and cache is not returned as a default.
+                # So we disable `use_cache` here for PyTorch model.
+                pt_model.config.use_cache = False
+
+                fx_model_class_name = "Flax" + model_class.__name__
+
+                if not hasattr(transformers, fx_model_class_name):
+                    return
+
+                fx_model_class = getattr(transformers, fx_model_class_name)
+
+                # load Flax class
+                fx_model = fx_model_class(config, dtype=jnp.float32)
+                # make sure only flax inputs are forward that actually exist in function args
+                fx_input_keys = inspect.signature(fx_model.__call__).parameters.keys()
+
+                # prepare inputs
+                pt_inputs = self._prepare_for_class(inputs_dict, model_class)
+
+                # remove function args that don't exist in Flax
+                pt_inputs = {k: v for k, v in pt_inputs.items() if k in fx_input_keys}
+
+                fx_state = convert_pytorch_state_dict_to_flax(pt_model.state_dict(), fx_model)
+                fx_model.params = fx_state
+
+                with torch.no_grad():
+                    pt_outputs = pt_model(**pt_inputs).to_tuple()
+
+                # convert inputs to Flax
+                fx_inputs = {k: np.array(v) for k, v in pt_inputs.items() if torch.is_tensor(v)}
+                fx_outputs = fx_model(**fx_inputs).to_tuple()
+                self.assertEqual(len(fx_outputs), len(pt_outputs), "Output lengths differ between Flax and PyTorch")
+                for fx_output, pt_output in zip(fx_outputs, pt_outputs):
+                    self.assert_almost_equals(fx_output, pt_output.numpy(), 4e-2)
+
+                with tempfile.TemporaryDirectory() as tmpdirname:
+                    pt_model.save_pretrained(tmpdirname)
+                    fx_model_loaded = fx_model_class.from_pretrained(tmpdirname, from_pt=True)
+
+                fx_outputs_loaded = fx_model_loaded(**fx_inputs).to_tuple()
+                self.assertEqual(
+                    len(fx_outputs_loaded), len(pt_outputs), "Output lengths differ between Flax and PyTorch"
+                )
+                for fx_output_loaded, pt_output in zip(fx_outputs_loaded, pt_outputs):
+                    self.assert_almost_equals(fx_output_loaded, pt_output.numpy(), 4e-2)
+
+    @is_pt_flax_cross_test
+    def test_equivalence_flax_to_pt(self):
+        config, inputs_dict = self.model_tester.prepare_config_and_inputs_for_common()
+
+        for model_class in self.all_model_classes:
+            with self.subTest(model_class.__name__):
+                # load corresponding PyTorch class
+                pt_model = model_class(config).eval()
+
+                # So we disable `use_cache` here for PyTorch model.
+                pt_model.config.use_cache = False
+
+                fx_model_class_name = "Flax" + model_class.__name__
+
+                if not hasattr(transformers, fx_model_class_name):
+                    # no flax model exists for this class
+                    return
+
+                fx_model_class = getattr(transformers, fx_model_class_name)
+
+                # load Flax class
+                fx_model = fx_model_class(config, dtype=jnp.float32)
+                # make sure only flax inputs are forward that actually exist in function args
+                fx_input_keys = inspect.signature(fx_model.__call__).parameters.keys()
+
+                pt_model = load_flax_weights_in_pytorch_model(pt_model, fx_model.params)
+
+                # make sure weights are tied in PyTorch
+                pt_model.tie_weights()
+
+                # prepare inputs
+                pt_inputs = self._prepare_for_class(inputs_dict, model_class)
+
+                # remove function args that don't exist in Flax
+                pt_inputs = {k: v for k, v in pt_inputs.items() if k in fx_input_keys}
+
+                with torch.no_grad():
+                    pt_outputs = pt_model(**pt_inputs).to_tuple()
+
+                fx_inputs = {k: np.array(v) for k, v in pt_inputs.items() if torch.is_tensor(v)}
+
+                fx_outputs = fx_model(**fx_inputs).to_tuple()
+                self.assertEqual(len(fx_outputs), len(pt_outputs), "Output lengths differ between Flax and PyTorch")
+
+                for fx_output, pt_output in zip(fx_outputs, pt_outputs):
+                    self.assert_almost_equals(fx_output, pt_output.numpy(), 4e-2)
+
+                with tempfile.TemporaryDirectory() as tmpdirname:
+                    fx_model.save_pretrained(tmpdirname)
+                    pt_model_loaded = model_class.from_pretrained(tmpdirname, from_flax=True)
+
+                with torch.no_grad():
+                    pt_outputs_loaded = pt_model_loaded(**pt_inputs).to_tuple()
+
+                self.assertEqual(
+                    len(fx_outputs), len(pt_outputs_loaded), "Output lengths differ between Flax and PyTorch"
+                )
+                for fx_output, pt_output in zip(fx_outputs, pt_outputs_loaded):
+                    self.assert_almost_equals(fx_output, pt_output.numpy(), 4e-2)
+
     def test_inputs_embeds(self):
         config, inputs_dict = self.model_tester.prepare_config_and_inputs_for_common()
 

tests/test_modeling_longformer.py

@@ -72,7 +72,7 @@ class LongformerModelTester:
         # because its local attention only attends to `self.attention_window + 1` locations
         # (assuming no token with global attention, otherwise the last dimension of attentions
         # is x + self.attention_window + 1, where x is the number of tokens with global attention)
-        self.key_length = self.attention_window + 1
+        self.key_length = self.attention_window + 2
 
         # because of padding `encoder_seq_length`, is different from `seq_length`. Relevant for
         # the `test_attention_outputs` and `test_hidden_states_output` tests
@@ -243,6 +243,8 @@ class LongformerModelTester:
             choice_labels,
         ) = config_and_inputs
         global_attention_mask = torch.zeros_like(input_ids)
+        global_attention_mask[:, -1] = 1
+
         inputs_dict = {
             "input_ids": input_ids,
             "token_type_ids": token_type_ids,

tests/test_modeling_lxmert.py

@@ -15,13 +15,16 @@
 
 
 import copy
+import os
+import tempfile
 import unittest
 
 import numpy as np
 
-from transformers import LxmertConfig, is_torch_available
+import transformers
+from transformers import LxmertConfig, is_tf_available, is_torch_available
 from transformers.models.auto import get_values
-from transformers.testing_utils import require_torch, slow, torch_device
+from transformers.testing_utils import is_pt_tf_cross_test, require_torch, slow, torch_device
 
 from .test_configuration_common import ConfigTester
 from .test_modeling_common import ModelTesterMixin, ids_tensor
@@ -40,6 +43,10 @@ if is_torch_available():
     from transformers.models.lxmert.modeling_lxmert import LXMERT_PRETRAINED_MODEL_ARCHIVE_LIST
 
 
+if is_tf_available():
+    import tensorflow as tf
+
+
 class LxmertModelTester:
     """You can also import this e.g from .test_modeling_bart import BartModelTester"""
 
@@ -496,7 +503,7 @@ class LxmertModelTester:
             result_pretrain_more.question_answering_score.shape, (self.batch_size, num_large_labels)
         )
 
-    def prepare_config_and_inputs_for_common(self):
+    def prepare_config_and_inputs_for_common(self, return_obj_labels=False):
         config_and_inputs = self.prepare_config_and_inputs()
         (
             config,
@@ -520,6 +527,9 @@ class LxmertModelTester:
             "attention_mask": input_mask,
         }
 
+        if return_obj_labels:
+            inputs_dict["obj_labels"] = obj_labels
+
         return config, inputs_dict
 
 
@@ -732,6 +742,128 @@ class LxmertModelTest(ModelTesterMixin, unittest.TestCase):
         self.assertIsNotNone(hidden_states_vision.grad)
         self.assertIsNotNone(attentions_vision.grad)
 
+    @is_pt_tf_cross_test
+    def test_pt_tf_model_equivalence(self):
+        for model_class in self.all_model_classes:
+            config, inputs_dict = self.model_tester.prepare_config_and_inputs_for_common(
+                return_obj_labels="PreTraining" in model_class.__name__
+            )
+
+            tf_model_class_name = "TF" + model_class.__name__  # Add the "TF" at the beginning
+
+            if not hasattr(transformers, tf_model_class_name):
+                # transformers does not have TF version yet
+                return
+
+            tf_model_class = getattr(transformers, tf_model_class_name)
+
+            config.output_hidden_states = True
+            config.task_obj_predict = False
+
+            pt_model = model_class(config)
+            tf_model = tf_model_class(config)
+
+            # Check we can load pt model in tf and vice-versa with model => model functions
+            pt_inputs = self._prepare_for_class(inputs_dict, model_class)
+
+            def recursive_numpy_convert(iterable):
+                return_dict = {}
+                for key, value in iterable.items():
+                    if type(value) == bool:
+                        return_dict[key] = value
+                    if isinstance(value, dict):
+                        return_dict[key] = recursive_numpy_convert(value)
+                    else:
+                        if isinstance(value, (list, tuple)):
+                            return_dict[key] = (
+                                tf.convert_to_tensor(iter_value.numpy(), dtype=tf.int32) for iter_value in value
+                            )
+                        else:
+                            return_dict[key] = tf.convert_to_tensor(value.numpy(), dtype=tf.int32)
+                return return_dict
+
+            tf_inputs_dict = recursive_numpy_convert(pt_inputs)
+
+            tf_model = transformers.load_pytorch_model_in_tf2_model(tf_model, pt_model, tf_inputs=tf_inputs_dict)
+            pt_model = transformers.load_tf2_model_in_pytorch_model(pt_model, tf_model)
+
+            # Check predictions on first output (logits/hidden-states) are close enought given low-level computational differences
+            pt_model.eval()
+
+            # Delete obj labels as we want to compute the hidden states and not the loss
+
+            if "obj_labels" in inputs_dict:
+                del inputs_dict["obj_labels"]
+
+            def torch_type(key):
+                if key in ("visual_feats", "visual_pos"):
+                    return torch.float32
+                else:
+                    return torch.long
+
+            pt_inputs = self._prepare_for_class(inputs_dict, model_class)
+            tf_inputs_dict = recursive_numpy_convert(pt_inputs)
+
+            with torch.no_grad():
+                pto = pt_model(**pt_inputs)
+            tfo = tf_model(tf_inputs_dict, training=False)
+            tf_hidden_states = tfo[0].numpy()
+            pt_hidden_states = pto[0].numpy()
+
+            tf_nans = np.copy(np.isnan(tf_hidden_states))
+            pt_nans = np.copy(np.isnan(pt_hidden_states))
+
+            pt_hidden_states[tf_nans] = 0
+            tf_hidden_states[tf_nans] = 0
+            pt_hidden_states[pt_nans] = 0
+            tf_hidden_states[pt_nans] = 0
+
+            max_diff = np.amax(np.abs(tf_hidden_states - pt_hidden_states))
+            # Debug info (remove when fixed)
+            if max_diff >= 2e-2:
+                print("===")
+                print(model_class)
+                print(config)
+                print(inputs_dict)
+                print(pt_inputs)
+            self.assertLessEqual(max_diff, 6e-2)
+
+            # Check we can load pt model in tf and vice-versa with checkpoint => model functions
+            with tempfile.TemporaryDirectory() as tmpdirname:
+                pt_checkpoint_path = os.path.join(tmpdirname, "pt_model.bin")
+                torch.save(pt_model.state_dict(), pt_checkpoint_path)
+                tf_model = transformers.load_pytorch_checkpoint_in_tf2_model(tf_model, pt_checkpoint_path)
+
+                tf_checkpoint_path = os.path.join(tmpdirname, "tf_model.h5")
+                tf_model.save_weights(tf_checkpoint_path)
+                pt_model = transformers.load_tf2_checkpoint_in_pytorch_model(pt_model, tf_checkpoint_path)
+
+            # Check predictions on first output (logits/hidden-states) are close enought given low-level computational differences
+            pt_model.eval()
+
+            for key, value in pt_inputs.items():
+                if key in ("visual_feats", "visual_pos"):
+                    pt_inputs[key] = value.to(torch.float32)
+                else:
+                    pt_inputs[key] = value.to(torch.long)
+
+            with torch.no_grad():
+                pto = pt_model(**pt_inputs)
+
+            tfo = tf_model(tf_inputs_dict)
+            tfo = tfo[0].numpy()
+            pto = pto[0].numpy()
+            tf_nans = np.copy(np.isnan(tfo))
+            pt_nans = np.copy(np.isnan(pto))
+
+            pto[tf_nans] = 0
+            tfo[tf_nans] = 0
+            pto[pt_nans] = 0
+            tfo[pt_nans] = 0
+
+            max_diff = np.amax(np.abs(tfo - pto))
+            self.assertLessEqual(max_diff, 6e-2)
+
 
 @require_torch
 class LxmertModelIntegrationTest(unittest.TestCase):

tests/test_modeling_tf_common.py

@@ -431,7 +431,6 @@ class TFModelTesterMixin:
 
     @is_pt_tf_cross_test
     def test_pt_tf_model_equivalence(self):
-
         import torch
 
         import transformers

tests/test_modeling_wav2vec2.py

@@ -22,7 +22,14 @@ import pytest
 
 from tests.test_modeling_common import floats_tensor, ids_tensor, random_attention_mask
 from transformers import Wav2Vec2Config, is_torch_available
-from transformers.testing_utils import require_datasets, require_soundfile, require_torch, slow, torch_device
+from transformers.testing_utils import (
+    is_pt_flax_cross_test,
+    require_datasets,
+    require_soundfile,
+    require_torch,
+    slow,
+    torch_device,
+)
 
 from .test_configuration_common import ConfigTester
 from .test_modeling_common import ModelTesterMixin, _config_zero_init
@@ -131,6 +138,7 @@ class Wav2Vec2ModelTester:
             hidden_dropout_prob=self.hidden_dropout_prob,
             intermediate_size=self.intermediate_size,
             layer_norm_eps=self.layer_norm_eps,
+            do_stable_layer_norm=self.do_stable_layer_norm,
             hidden_act=self.hidden_act,
             initializer_range=self.initializer_range,
             vocab_size=self.vocab_size,
@@ -357,6 +365,16 @@ class Wav2Vec2ModelTest(ModelTesterMixin, unittest.TestCase):
     def test_model_common_attributes(self):
         pass
 
+    @is_pt_flax_cross_test
+    # non-robust architecture does not exist in Flax
+    def test_equivalence_flax_to_pt(self):
+        pass
+
+    @is_pt_flax_cross_test
+    # non-robust architecture does not exist in Flax
+    def test_equivalence_pt_to_flax(self):
+        pass
+
     def test_retain_grad_hidden_states_attentions(self):
         config, inputs_dict = self.model_tester.prepare_config_and_inputs_for_common()
         config.output_hidden_states = True