Add fusion patterns for conformer-transducer model (#18461)

### Description
Add conformer-transducer model type to optimizer. This PR adds pattern
matches for attention shown below:
Unfused attention:

![ct_unfused](https://github.com/microsoft/onnxruntime/assets/111780983/46c71ed8-67e0-4607-85b1-bcadba5a2956)

Fused attention:

![ct_fused](https://github.com/microsoft/onnxruntime/assets/111780983/fbb91c96-0d4b-4f0b-8674-1ae3b9b9a92e)

cmake/onnxruntime_python.cmake

@@ -436,6 +436,9 @@ if (onnxruntime_BUILD_UNIT_TESTS)
   file(GLOB onnxruntime_python_transformers_testdata_whisper CONFIGURE_DEPENDS
       "${ONNXRUNTIME_ROOT}/test/python/transformers/test_data/models/whisper/*.onnx"
   )
+  file(GLOB onnxruntime_python_transformers_testdata_conformer CONFIGURE_DEPENDS
+      "${ONNXRUNTIME_ROOT}/test/python/transformers/test_data/models/conformer/*.onnx"
+  )
 endif()
 
 file(GLOB onnxruntime_python_tools_srcs CONFIGURE_DEPENDS
@@ -549,6 +552,7 @@ add_custom_command(
   COMMAND ${CMAKE_COMMAND} -E make_directory $<TARGET_FILE_DIR:${build_output_target}>/transformers/test_data/models
   COMMAND ${CMAKE_COMMAND} -E make_directory $<TARGET_FILE_DIR:${build_output_target}>/transformers/test_data/models/whisper
   COMMAND ${CMAKE_COMMAND} -E make_directory $<TARGET_FILE_DIR:${build_output_target}>/eager_test
+  COMMAND ${CMAKE_COMMAND} -E make_directory $<TARGET_FILE_DIR:${build_output_target}>/transformers/test_data/models/conformer
   COMMAND ${CMAKE_COMMAND} -E copy
       ${ONNXRUNTIME_ROOT}/__init__.py
       $<TARGET_FILE_DIR:${build_output_target}>/onnxruntime/
@@ -701,6 +705,9 @@ if (onnxruntime_BUILD_UNIT_TESTS)
     COMMAND ${CMAKE_COMMAND} -E copy
         ${onnxruntime_python_transformers_testdata_whisper}
         $<TARGET_FILE_DIR:${build_output_target}>/transformers/test_data/models/whisper/
+    COMMAND ${CMAKE_COMMAND} -E copy
+        ${onnxruntime_python_transformers_testdata_conformer}
+        $<TARGET_FILE_DIR:${build_output_target}>/transformers/test_data/models/conformer/
   )
 endif()
 

onnxruntime/python/tools/transformers/fusion_attention.py

@@ -657,7 +657,6 @@ def create_multihead_attention_node(
             return None
 
         graph_input_names = set([node.name for node in self.model.graph().input])
-        graph_output_names = set([node.name for node in self.model.graph().output])
         mha_node_name = self.model.create_node_name("Attention")
 
         # Add initial Q/K/V inputs for MHA
@@ -693,12 +692,15 @@ def create_multihead_attention_node(
             mha_inputs.append("")
 
         # Add optional inputs for MHA
-        if past_k and past_v and past_k in graph_input_names and past_v in graph_input_names:
+
+        if past_k and past_v:
             mha_inputs.extend([key_padding_mask, add_qk, past_k, past_v])
+        elif key_padding_mask or add_qk:
+            mha_inputs.extend([key_padding_mask, add_qk])
 
         # Add outputs for MHA
         mha_outputs = [output]
-        if present_k and present_v and present_k in graph_output_names and present_v in graph_output_names:
+        if present_k and present_v:
             mha_outputs.extend([present_k, present_v])
 
         mha_node = helper.make_node(

onnxruntime/python/tools/transformers/fusion_conformer_attention.py

@@ -0,0 +1,143 @@
+# -------------------------------------------------------------------------
+# Copyright (c) Microsoft Corporation.  All rights reserved.
+# Licensed under the MIT License.
+# --------------------------------------------------------------------------
+import logging
+
+from fusion_attention import AttentionMask, FusionAttention
+from onnx_model import OnnxModel
+
+logger = logging.getLogger(__name__)
+
+
+class FusionConformerAttention(FusionAttention):
+    """
+    Fuse Conformer Attention subgraph into one MultiHeadAttention node.
+    """
+
+    def __init__(
+        self,
+        model: OnnxModel,
+        hidden_size: int,
+        num_heads: int,
+        attention_mask: AttentionMask,
+    ):
+        super().__init__(model, hidden_size, num_heads, attention_mask)
+
+    def fuse(self, normalize_node, input_name_to_nodes, output_name_to_node):
+        # SkipLayerNormalization has two inputs, and one of them is the root input for attention.
+        qkv_nodes = self.model.match_parent_path(
+            normalize_node,
+            ["Add", "MatMul", "Reshape", "Transpose", "MatMul"],
+            [1, 1, 0, 0, 0],
+        )
+        if qkv_nodes is not None:
+            (
+                _,
+                _,
+                reshape_qkv,
+                transpose_qkv,
+                matmul_qkv,
+            ) = qkv_nodes
+        else:
+            logger.debug("fuse_conformer_attention: failed to match qkv path")
+            return
+
+        v_nodes = self.model.match_parent_path(
+            matmul_qkv,
+            ["Concat", "Transpose", "Reshape", "Add", "MatMul"],
+            [1, 1, 0, 0, 1],
+        )
+
+        add_v = None
+        if v_nodes is not None:
+            (concat_v, _, _, add_v, matmul_v) = v_nodes
+            concat_parent = self.model.get_parent(concat_v, 0, None)
+            present_v = concat_v.output[0]
+            past_v = concat_parent.output[0]
+        else:
+            logger.debug("fuse_conformer_attention: failed to match v path")
+            return
+
+        qk_nodes = self.model.match_parent_path(matmul_qkv, ["Softmax", "Add", "MatMul"], [0, 0, 0])
+
+        if qk_nodes is not None:
+            _, add_qk, matmul_qk = qk_nodes
+        else:
+            logger.debug("fuse_conformer_attention: failed to match qk path")
+            return
+
+        q_nodes = self.model.match_parent_path(
+            matmul_qk,
+            ["Div", "Transpose", "Reshape", "Add", "MatMul"],
+            [0, 0, 0, 0, 1],
+        )
+        if q_nodes is not None:
+            _, _, reshape_q, add_q, matmul_q = q_nodes
+        else:
+            logger.debug("fuse_conformer_attention: failed to match q path")
+            return
+
+        k_nodes = self.model.match_parent_path(
+            matmul_qk,
+            ["Transpose", "Concat", "Transpose", "Reshape", "Add", "MatMul"],
+            [1, 0, 1, 0, 0, 1],
+        )
+
+        matmul_k = None
+        if k_nodes is not None:
+            _, concat_k, _, _, add_k, matmul_k = k_nodes
+            concat_parent = self.model.get_parent(concat_k, 0, None)
+            past_k = concat_parent.output[0]
+            present_k = concat_k.output[0]
+        else:
+            logger.debug("fuse_conformer_attention: failed to match k path")
+            return
+
+        attention_last_node = reshape_qkv
+        num_heads, hidden_size = self.get_num_heads_and_hidden_size(reshape_q)
+
+        if num_heads <= 0 or hidden_size <= 0 or (hidden_size % num_heads) != 0:
+            logger.debug("fuse_conformer_attention: failed to detect num_heads or hidden_size")
+            return
+
+        new_node = self.create_multihead_attention_node(
+            matmul_q,
+            matmul_k,
+            matmul_v,
+            add_q,
+            add_k,
+            add_v,
+            num_heads,
+            hidden_size,
+            attention_last_node.output[0],
+            add_qk=add_qk.input[1],
+            past_k=past_k,
+            past_v=past_v,
+            present_k=present_k,
+            present_v=present_v,
+        )
+
+        if new_node is None:
+            logger.debug("fuse_conformer_attention: MultiHeadAttention node creation failed")
+            return
+
+        self.nodes_to_add.append(new_node)
+        self.node_name_to_graph_name[new_node.name] = self.this_graph_name
+
+        self.nodes_to_remove.extend([attention_last_node, transpose_qkv, matmul_qkv])
+        self.nodes_to_remove.extend(qk_nodes)
+
+        # When using multihead attention, keep MatMul nodes in original graph
+        if q_nodes[-1].op_type == "MatMul":
+            q_nodes.pop()
+        if k_nodes[-1].op_type == "MatMul":
+            k_nodes.pop()
+        if v_nodes[-1].op_type == "MatMul":
+            v_nodes.pop()
+
+        self.nodes_to_remove.extend(k_nodes)
+        self.nodes_to_remove.extend(v_nodes)
+
+        # Use prune graph to remove mask nodes since they are shared by all attention nodes.
+        self.prune_graph = True

onnxruntime/python/tools/transformers/onnx_model_conformer.py

@@ -0,0 +1,33 @@
+# -------------------------------------------------------------------------
+# Copyright (c) Microsoft Corporation.  All rights reserved.
+# Licensed under the MIT License.
+# --------------------------------------------------------------------------
+import logging
+from typing import Optional
+
+from fusion_attention import AttentionMask
+from fusion_conformer_attention import FusionConformerAttention
+from fusion_options import FusionOptions
+from onnx_model_bert import BertOnnxModel
+
+logger = logging.getLogger(__name__)
+
+
+class ConformerOnnxModel(BertOnnxModel):
+    def __init__(self, model, num_heads, hidden_size):
+        super().__init__(model, num_heads, hidden_size)
+        self.attention_mask = AttentionMask(self)
+        self.attention_fusion = FusionConformerAttention(self, self.hidden_size, self.num_heads, self.attention_mask)
+
+    def optimize(self, options: Optional[FusionOptions] = None, add_dynamic_axes: bool = False):
+        self.attention_fusion.use_multi_head_attention = False if options is None else options.use_multi_head_attention
+        self.attention_fusion.disable_multi_head_attention_bias = (
+            False if options is None else options.disable_multi_head_attention_bias
+        )
+        super().optimize(options, add_dynamic_axes)
+
+    def fuse_attention(self):
+        self.attention_fusion.apply()
+
+    def preprocess(self):
+        self.adjust_reshape_and_expand()

onnxruntime/python/tools/transformers/optimizer.py

@@ -32,6 +32,7 @@
 from onnx_model_bert_keras import BertOnnxModelKeras
 from onnx_model_bert_tf import BertOnnxModelTF
 from onnx_model_clip import ClipOnnxModel
+from onnx_model_conformer import ConformerOnnxModel
 from onnx_model_gpt2 import Gpt2OnnxModel
 from onnx_model_t5 import T5OnnxModel
 from onnx_model_tnlr import TnlrOnnxModel
@@ -56,6 +57,7 @@
     "unet": (UnetOnnxModel, "pytorch", 1),  # UNet in Stable Diffusion
     "vae": (VaeOnnxModel, "pytorch", 1),  # UAE in Stable Diffusion
     "vit": (BertOnnxModel, "pytorch", 1),
+    "conformer": (ConformerOnnxModel, "pytorch", 1),
 }