#------------------------------------------------------------------------- # Copyright (c) Microsoft Corporation. All rights reserved. # Licensed under the MIT License. #-------------------------------------------------------------------------- from typing import Dict, Optional from logging import getLogger from onnx import helper from onnx_model import OnnxModel from fusion_base import Fusion logger = getLogger(__name__) class FusionFastGelu(Fusion): def __init__(self, model: OnnxModel): super().__init__(model, "FastGelu", "Tanh") def fuse(self, erf_node, input_name_to_nodes: Dict, output_name_to_node: Dict): if self.fuse_1(erf_node, input_name_to_nodes, output_name_to_node): return self.fuse_2(erf_node, input_name_to_nodes, output_name_to_node) def fuse_1(self, tanh_node, input_name_to_nodes, output_name_to_node) -> Optional[bool]: """ Fuse Gelu with tanh into one node: +---------------------------+ | | | v [root] --> Pow --> Mul -----> Add --> Mul --> Tanh --> Add --> Mul | (Y=3) (B=0.0447...) (B=0.7978...) (B=1) ^ | | +------> Mul(B=0.5)--------------------------------------------+ Note that constant input for Add and Mul could be first or second input: like either A=0.5 or B=0.5 is fine. """ if tanh_node.output[0] not in input_name_to_nodes: return children = input_name_to_nodes[tanh_node.output[0]] if len(children) != 1 or children[0].op_type != 'Add': return add_after_tanh = children[0] if not self.model.has_constant_input(add_after_tanh, 1.0): return if add_after_tanh.output[0] not in input_name_to_nodes: return children = input_name_to_nodes[add_after_tanh.output[0]] if len(children) != 1 or children[0].op_type != 'Mul': return mul_after_tanh = children[0] mul_half = self.model.match_parent(mul_after_tanh, 'Mul', None, output_name_to_node) if mul_half is None: return i = self.model.find_constant_input(mul_half, 0.5) if i < 0: return root_node = self.model.get_parent(mul_half, 0 if i == 1 else 1, output_name_to_node) if root_node is None: return mul_before_tanh = self.model.match_parent(tanh_node, 'Mul', 0, output_name_to_node) if mul_before_tanh is None: return i = self.model.find_constant_input(mul_before_tanh, 0.7978, delta=0.0001) if i < 0: return add_before_tanh = self.model.match_parent(mul_before_tanh, 'Add', 0 if i == 1 else 1, output_name_to_node) if add_before_tanh is None: return mul_after_pow = self.model.match_parent(add_before_tanh, 'Mul', None, output_name_to_node, exclude=[root_node]) if mul_after_pow is None: return i = self.model.find_constant_input(mul_after_pow, 0.0447, delta=0.0001) if i < 0: return pow = self.model.match_parent(mul_after_pow, 'Pow', 0 if i == 1 else 1, output_name_to_node) if pow is None: return if not self.model.has_constant_input(pow, 3.0): return if pow.input[0] != root_node.output[0]: return subgraph_nodes = [ mul_after_tanh, mul_half, add_after_tanh, tanh_node, mul_before_tanh, add_before_tanh, mul_after_pow, pow ] if not self.model.is_safe_to_fuse_nodes(subgraph_nodes, [mul_after_tanh.output[0]], input_name_to_nodes, output_name_to_node): return self.nodes_to_remove.extend(subgraph_nodes) fused_node = helper.make_node('FastGelu', inputs=[root_node.output[0]], outputs=mul_after_tanh.output, name=self.model.create_node_name('FastGelu')) fused_node.domain = "com.microsoft" self.nodes_to_add.append(fused_node) def fuse_2(self, tanh_node, input_name_to_nodes: Dict, output_name_to_node: Dict) -> Optional[bool]: """ This pattern is from Tensorflow mode. Fuse Gelu with tanh into one node: +---------------------------+ | | | v [root] --> Pow --> Mul -----> Add --> Mul --> Tanh --> Add --> Mul(B=0.5)-->Mul--> | (Y=3) (B=0.0447...) (B=0.7978...) (B=1) ^ | | +---------------------------------------------------------------------------+ Note that constant input for Add and Mul could be first or second input: like either A=0.5 or B=0.5 is fine. """ if tanh_node.output[0] not in input_name_to_nodes: return children = input_name_to_nodes[tanh_node.output[0]] if len(children) != 1 or children[0].op_type != 'Add': return add_after_tanh = children[0] if not self.model.has_constant_input(add_after_tanh, 1.0): return if add_after_tanh.output[0] not in input_name_to_nodes: return children = input_name_to_nodes[add_after_tanh.output[0]] if len(children) != 1 or children[0].op_type != 'Mul': return mul_half = children[0] i = self.model.find_constant_input(mul_half, 0.5) if i < 0: return if mul_half.output[0] not in input_name_to_nodes: return children = input_name_to_nodes[mul_half.output[0]] if len(children) != 1 or children[0].op_type != 'Mul': return mul_after_mul_half = children[0] root_node = self.model.get_parent(mul_after_mul_half, 0 if mul_after_mul_half.input[1] == mul_half.output[0] else 1, output_name_to_node) if root_node is None: return mul_before_tanh = self.model.match_parent(tanh_node, 'Mul', 0, output_name_to_node) if mul_before_tanh is None: return i = self.model.find_constant_input(mul_before_tanh, 0.7978, delta=0.0001) if i < 0: return add_before_tanh = self.model.match_parent(mul_before_tanh, 'Add', 0 if i == 1 else 1, output_name_to_node) if add_before_tanh is None: return mul_after_pow = self.model.match_parent(add_before_tanh, 'Mul', None, output_name_to_node, exclude=[root_node]) if mul_after_pow is None: return i = self.model.find_constant_input(mul_after_pow, 0.0447, delta=0.0001) if i < 0: return pow = self.model.match_parent(mul_after_pow, 'Pow', 0 if i == 1 else 1, output_name_to_node) if pow is None: return if not self.model.has_constant_input(pow, 3.0): return if pow.input[0] != root_node.output[0]: return subgraph_nodes = [ mul_after_mul_half, mul_half, add_after_tanh, tanh_node, mul_before_tanh, add_before_tanh, mul_after_pow, pow ] if not self.model.is_safe_to_fuse_nodes(subgraph_nodes, [mul_after_mul_half.output[0]], input_name_to_nodes, output_name_to_node): return self.nodes_to_remove.extend(subgraph_nodes) fused_node = helper.make_node('FastGelu', inputs=[root_node.output[0]], outputs=mul_after_mul_half.output, name=self.model.create_node_name('FastGelu')) fused_node.domain = "com.microsoft" self.nodes_to_add.append(fused_node) return True