# Copyright (C) 2020 Arm Limited or its affiliates. All rights reserved. # # SPDX-License-Identifier: Apache-2.0 # # Licensed under the Apache License, Version 2.0 (the License); you may # not use this file except in compliance with the License. # You may obtain a copy of the License at # # www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an AS IS BASIS, WITHOUT # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. # Description: # Early optimisation of the network graph, using the rewrite_graph module to do the traversal of the graph. These are # split into two parts optimise_graph_a and optimise_graph_b. import math import numpy as np from . import fp_math from . import lut from . import rewrite_graph from . import scaling from .data_type import DataType from .debug_database import DebugDatabase from .errors import UnsupportedFeatureError from .ethos_u55_regs.ethos_u55_regs import resampling_mode from .numeric_util import clamp_sigmoid from .numeric_util import full_shape from .numeric_util import round_away_zero from .operation import create_activation_function from .operation import create_avgpool_nop from .operation import NpuBlockType from .operation import Op from .operation import Operation from .softmax import SoftMax from .tensor import check_quantized_tens_scaling_equal from .tensor import create_const_tensor from .tensor import create_reshape_tensor from .tensor import QuantizationParameters from .tensor import Tensor passthrough_nodes = set((Op.Identity,)) memory_only_ops = set((Op.Reshape,)) def remove_passthrough_tensor(tens, arch, nng): if len(tens.ops) == 1 and tens.ops[0].type in passthrough_nodes: assert len(tens.ops[0].inputs) == 1 tens = tens.ops[0].inputs[0] return tens def rewrite_concat(tens, arch, nng): if len(tens.ops) == 1 and tens.ops[0].type.is_concat_op(): concat_op = tens.ops[0] if tens != concat_op.outputs[0]: return tens # don't attempt to rewrite the min/max outputs of QuantizedConcat # Not supported so leave it and run on CPU if not concat_op.run_on_npu: return tens inputs, axis = concat_op.get_concat_inputs_axis() tens.ops = [] offset = 0 for idx, inp in enumerate(inputs): new_op = Operation(Op.ConcatSliceWrite, concat_op.name + str(idx)) new_op.inputs = [inp] new_op.outputs = [tens] new_op.attrs["concat_axis"] = axis new_op.attrs["concat_start"] = offset offset += inp.shape[axis] new_op.attrs["concat_end"] = offset new_op.run_on_npu = True tens.ops.append(new_op) DebugDatabase.add_optimised(concat_op, new_op) assert tens.shape[axis] == offset # If axis corresponds to C-dimension, NHCWB16 can only be used in the output if all the concat_start's are a # multiple of 16. This as, it is only then the address offset for the ofm, for all operations, will be 16 byte # aligned. For other values of axis the address offsets will be 16 byte aligned, as they are all based on c = 0 # and those addresses are always 16 byte aligned due to the NHCWB16 format. if axis == -1 or axis == (len(tens.shape) - 1): for op in tens.ops: if op.attrs["concat_start"] % 16 != 0: tens.avoid_NHCWB16 = True break return tens def rewrite_split(tens, arch, nng): if len(tens.ops) == 1 and tens.ops[0].type.is_split_op(): split_op = tens.ops[0] # Not supported so leave it and run on CPU if not split_op.run_on_npu: return tens inp, outputs, axis, offset_start, offset_end = split_op.get_split_inputs_axis() tens.ops = [] new_op = Operation(Op.SplitSliceRead, split_op.name) new_op.inputs = [inp] # For Split the offset cannot be extracted from the tensor so it has to # be calculated from the index of the output tensor if axis is not None: # Get the start and end of the split offset_start = [0] * len(tens.shape) offset_end = [0] * len(tens.shape) for out in outputs: if out == tens: break offset_start[axis] += out.shape[axis] # If start offset is not a multiple of 16 in the C-dimension, NHCWB16 need to be avoided in the input if (offset_start[-1] % 16) != 0: inp.avoid_NHCWB16 = True offset_end[axis] = offset_start[axis] + tens.shape[axis] new_op.attrs["split_start"] = offset_start new_op.attrs["split_end"] = offset_end new_op.run_on_npu = True new_op.set_output_tensor(tens) DebugDatabase.add_optimised(split_op, new_op) return tens def needed_total_padding(input_size, stride, filter_size): out_size = (input_size + stride - 1) // stride needed_input = (out_size - 1) * stride + filter_size total_padding = max(0, needed_input - input_size) return total_padding def calc_padding_and_skirt(padding_type, kernel_size, stride, input_dims): ypad = needed_total_padding(int(input_dims[1]), int(stride[1]), int(kernel_size[0])) xpad = needed_total_padding(int(input_dims[2]), int(stride[2]), int(kernel_size[1])) if padding_type == b"SAME": left_pad = (xpad + 0) // 2 right_pad = (xpad + 1) // 2 top_pad = (ypad + 0) // 2 bottom_pad = (ypad + 1) // 2 elif padding_type == b"VALID": left_pad = 0 right_pad = 0 top_pad = 0 bottom_pad = 0 else: raise UnsupportedFeatureError("Unknown padding {}".format(str(padding_type))) padding = (top_pad, left_pad, bottom_pad, right_pad) skirt = (top_pad, left_pad, ypad - top_pad, xpad - left_pad) return padding, skirt def calc_upscaled_padding_and_skirt(padding_type, kernel_size, stride, input_dims, upscaling_factor): kernel_height, kernel_width = kernel_size[0], kernel_size[1] if padding_type == b"SAME": ypad = needed_total_padding(int(input_dims[1]) * upscaling_factor, int(stride[1]), int(kernel_height)) xpad = needed_total_padding(int(input_dims[2]) * upscaling_factor, int(stride[2]), int(kernel_width)) right_pad = max(((xpad + 1) // upscaling_factor) - 1, 0) bottom_pad = max(((ypad + 1) // upscaling_factor) - 1, 0) left_pad = max(kernel_width - 1 - right_pad, 0) top_pad = max(kernel_height - 1 - bottom_pad, 0) elif padding_type == b"VALID": right_pad = max(kernel_width - 2, 0) bottom_pad = max(kernel_height - 2, 0) left_pad = kernel_width - 1 top_pad = kernel_height - 1 else: assert 0, "Unknown padding" padding = (top_pad, left_pad, bottom_pad, right_pad) skirt = padding return padding, skirt def fixup_conv2d_backprop(op, arch, nng): if op.type == Op.Conv2DBackpropInput: # flip the inputs op.inputs[0], op.inputs[2] = op.inputs[2], op.inputs[0] op.type = Op.Conv2DBackpropInputSwitchedBias # Update strides op.attrs.update({"stride_w": 1, "stride_h": 1, "strides": (1, 1, 1, 1)}) return op # Convert the op to an elementwise add def convert_resizebilinear_1x1_to_add(op): op.type = Op.Add op.name = op.name + "_add" op.attrs["resizebilinear"] = True # Create an input tensor filled with zeros shape = op.outputs[0].shape tens = Tensor(shape, op.inputs[0].dtype, op.inputs[1].name + "_add") tens.values = np.zeros(shape) tens.quant_values = np.zeros(shape, np.uint8) tens.quantization = QuantizationParameters(0.0, 255.0) tens.quantization.scale_f32 = 1.0 tens.quantization.zero_point = 0 tens.consumer_list = [op] tens_op = op.inputs[1].ops[0] tens_op.set_output_tensor(tens) # Set the add inputs op.inputs[1] = op.inputs[0] op.inputs[0] = tens return op # Convert ResizeBilinear to a number of 2x2 pool ops def convert_resizebilinear_to_2x2_pool(op): count = 0 pre_op = op outputs = op.outputs op.attrs.update({"strides": (1, 1, 1, 1), "ksize": (1, 2, 2, 1)}) if op.attrs["align_corners"]: shape_modifier = 1 op.attrs["padding"] = b"VALID" else: shape_modifier = 0 op.attrs["padding"] = b"SAME" op.inputs[0].resampling_mode = resampling_mode.NEAREST upscaled_shape = np.array(op.inputs[0].shape[1:3]) out_shape = np.array(op.outputs[0].shape[1:3]) if (upscaled_shape == upscaled_shape * 2 - shape_modifier).all(): return op while (upscaled_shape < out_shape).all(): if count == 0: scaled_op = pre_op else: scaled_op = op.clone("_{}".format(count)) scaled_op.inputs[0] = pre_op.outputs[0] upscaled_shape = upscaled_shape * 2 - shape_modifier if (upscaled_shape == out_shape).all(): scaled_op.outputs = outputs scaled_op.outputs[0].ops = [scaled_op] else: shape = outputs[0].shape.copy() shape[1:3] = upscaled_shape[0:2] out_tens = Tensor(shape, DataType.int16, "{}_{}".format(op.outputs[0].name, count)) out_tens.quantization = op.outputs[0].quantization.clone() out_tens.quantization.quant_min = np.iinfo(np.int16).min out_tens.quantization.quant_max = np.iinfo(np.int16).max scaled_op.set_output_tensor(out_tens) pre_op = scaled_op count += 1 # Setup the scale value if scaled_op.inputs[0].dtype.bits == 8 and scaled_op.outputs[0].dtype.bits == 16: scaled_op.attrs["rescale"] = 128 elif scaled_op.inputs[0].dtype.bits == 16 and scaled_op.outputs[0].dtype.bits == 8: scaled_op.attrs["rescale"] = 1 / 128 elif "rescale" in scaled_op.attrs: del scaled_op.attrs["rescale"] return op def fixup_resizebilinear(op, arch, nng): if op.type == Op.ResizeBilinear and op.run_on_npu: if op.inputs[0].shape == op.outputs[0].shape: # Bypass nop resizebilinear op.inputs = op.inputs[:1] op.type = Op.Identity elif op.inputs[0].shape[1] == 1 and op.inputs[0].shape[2] == 1: convert_resizebilinear_1x1_to_add(op) else: convert_resizebilinear_to_2x2_pool(op) return op def convert_nop_split_to_identity(op, arch, nng): if op.type == Op.Split and op.attrs.get("num_splits") == 1: # the list comprehension should return a list with a single tensor # if it shouldn't, remove_passthrough_tensor will fail appropriately op.inputs = [i for i in op.inputs if i.shape == op.outputs[0].shape] op.type = Op.Identity return op def fixup_fully_connected_input(op, arch, nng): if op.type == Op.FullyConnected: inp = op.inputs[0] weights = op.inputs[1] n_in_elems = weights.shape[-2] elms = inp.elements() batch_size = elms // n_in_elems assert batch_size * n_in_elems == elms desired_shape = [batch_size, n_in_elems] if inp.shape != desired_shape: # mismatch, insert a reshape to fix this. op.set_input_tensor(create_reshape_tensor(inp, desired_shape), 0) return op def convert_batched_fc_shape(op, arch, nng): if op.type == Op.FullyConnected: ifm = op.inputs[0] ofm = op.outputs[0] # Check if the FC is 2D and first dimension indicates batching if len(ifm.shape) == len(ofm.shape) == 2 and ifm.shape[0] > 1: n = ifm.shape[0] batching_split = {4: (2, 2), 8: (2, 4), 16: (4, 4)} h, w = batching_split.get(n, (1, n)) prev_op = ifm.ops[0] desired_shape = [1, h, w, ifm.shape[-1]] if len(ifm.consumer_list) == 1 and prev_op is not None and prev_op.type == Op.Reshape: # There is a preceding Reshape # Compare input of prev_op and input of op, to see if prev_op can be removed ifm_prev_op = prev_op.inputs[0] if ifm_prev_op.shape == ifm.shape and check_quantized_tens_scaling_equal(ifm_prev_op, ifm): # prev_op can be removed op.set_input_tensor(ifm_prev_op, 0) else: op.inputs[0].set_all_shapes(desired_shape) prev_op.set_input_tensor( create_const_tensor(prev_op.inputs[1].name, [1], DataType.int32, desired_shape), 1 ) prev_op.attrs["new_shape"] = desired_shape else: # Add reshape op to the input if there is no preceding reshape ifm.consumer_list.remove(op) op.set_input_tensor(create_reshape_tensor(ifm, desired_shape), 0) # Reshape Weights to be 4D. IO becomes HWIO weight_tensor = op.inputs[1] weight_tensor.quant_values = np.expand_dims(np.expand_dims(weight_tensor.quant_values, axis=0), axis=0) weight_tensor.set_all_shapes(list(weight_tensor.quant_values.shape)) desired_shape = [1, h, w, ofm.shape[-1]] if ( len(ofm.consumer_list) == 1 and ofm.consumer_list[0] is not None and ofm.consumer_list[0].type == Op.Reshape ): # There is a subsequent Reshape # Compare desired shape and output of consumer op, to see if consumer op can be removed ofm_cons_op = ofm.consumer_list[0].outputs[0] if desired_shape == ofm_cons_op.shape and check_quantized_tens_scaling_equal(ofm, ofm_cons_op): op.outputs[0] = ofm_cons_op op.outputs[0].ops = [op] else: op.outputs[0].set_all_shapes(desired_shape) else: # Add reshape op to the output op.set_output_tensor(create_reshape_tensor(ofm, desired_shape, False)) return op def fixup_pack_input(op, arch, nng): if op.type == Op.Pack: # Pack is also referred to as Stack # Requires the rewrite_concat function to be called on the op afterwards axis = int(op.attrs["axis"]) desired_shape = op.inputs[0].shape[:axis] + [1] + op.inputs[0].shape[axis:] # Construct 1 shape tensor to be used by all inserted reshape ops new_shape_tens = create_const_tensor(op.name + "_reshape_shape", [1], DataType.int32, desired_shape) for idx, inp in enumerate(op.inputs): reshape_out = inp.clone("_reshaped") reshape_out.set_all_shapes(desired_shape) reshape_op = Operation(Op.Reshape, "{}{}_reshape".format(op.name, idx)) reshape_op.attrs["new_shape"] = desired_shape reshape_op.inputs = [inp, new_shape_tens] reshape_op.set_output_tensor(reshape_out) DebugDatabase.add_optimised(op, reshape_op) op.inputs[idx] = reshape_out op.type = Op.PackReshaped return op def unfuse_activation_function(op, arch, nng): if op.type == Op.ConcatTFLite and op.run_on_npu and op.activation is not None: act_op = Operation(op.activation.op_type, op.name + op.activation.op_type.name) op.activation = None out_tens = op.outputs[0] intermediate_tens = out_tens.clone("_act_intermediate") act_op.set_output_tensor(out_tens) act_op.add_input_tensor(intermediate_tens) op.set_output_tensor(intermediate_tens) return op def fixup_stridedslice_output(tens, arch, nng): op = tens.ops[0] if op.run_on_npu and op.type == Op.StridedSlice: reshape_input_shape = tens.shape new_axis_mask = op.attrs["new_axis_mask"] shrink_axis_mask = op.attrs["shrink_axis_mask"] if shrink_axis_mask != 0: n = 0 axis = 0 while shrink_axis_mask: prev_mask = shrink_axis_mask n += 1 shrink_axis_mask &= shrink_axis_mask - 1 axis = int(math.log2(prev_mask - shrink_axis_mask)) reshape_input_shape = reshape_input_shape[:axis] + [1] + reshape_input_shape[axis:] assert len(tens.shape) == (len(op.inputs[0].shape) - n) op.attrs["shrink_axis_mask"] = 0 elif new_axis_mask != 0: n = 0 axis = 0 while new_axis_mask: prev_mask = new_axis_mask n += 1 new_axis_mask &= new_axis_mask - 1 axis = int(math.log2(prev_mask - new_axis_mask)) reshape_input_shape = reshape_input_shape[:axis] + reshape_input_shape[(axis + 1) :] new_axis_mask >>= 1 assert len(tens.shape) == (len(op.inputs[0].shape) + n) op.attrs["new_axis_mask"] = 0 else: # Equal Rank StridedSlice, no need to insert reshape return tens # Construct 1 shape tensor to be used by all inserted reshape ops new_shape_tens = create_const_tensor(op.name + "_reshape_shape", [1], DataType.int32, tens.shape) for idx, out_tens in enumerate(op.outputs): reshape_in = out_tens.clone("_reshaped") reshape_in.set_all_shapes(reshape_input_shape) reshape_in.ops = [op] reshape_op = Operation(Op.Reshape, "{}{}_reshape".format(op.name, idx)) reshape_op.attrs["new_shape"] = reshape_input_shape reshape_op.inputs = [reshape_in, new_shape_tens] reshape_op.set_output_tensor(out_tens) op.outputs[idx] = reshape_in return tens def fixup_unpack_output(tens, arch, nng): op = tens.ops[0] if op.run_on_npu and op.type == Op.Unpack: # Unpack is also referred to as Unstack # Requires the rewrite_split function to be called on the op afterwards axis = int(op.attrs["axis"]) op.type = Op.UnpackReshaped reshape_input_shape = tens.shape[:axis] + [1] + tens.shape[axis:] # Construct 1 shape tensor to be used by all inserted reshape ops new_shape_tens = create_const_tensor(op.name + "_reshape_shape", [1], DataType.int32, tens.shape) for idx, out_tens in enumerate(op.outputs): reshape_in = out_tens.clone("_reshaped") reshape_in.set_all_shapes(reshape_input_shape) reshape_in.ops = [op] reshape_op = Operation(Op.Reshape, "{}{}_reshape".format(op.name, idx)) reshape_op.attrs["new_shape"] = reshape_input_shape reshape_op.inputs = [reshape_in, new_shape_tens] reshape_op.set_output_tensor(out_tens) DebugDatabase.add_optimised(op, reshape_op) op.outputs[idx] = reshape_in return tens def add_padding_fields(op, arch, nng): if op.run_on_npu: if "padding" in op.attrs: if op.type.is_conv2d_op() or op.type.is_depthwise_conv2d_op(): kernel_size = op.inputs[1].shape[:2] input_shape = op.inputs[0].shape elif op.type.is_pool_op() or op.type.npu_block_type == NpuBlockType.ReduceSum: kernel_size = op.attrs["ksize"][1:3] input_shape = op.inputs[0].shape else: raise UnsupportedFeatureError("Unknown operation that uses padding: {}".format(op.type)) if op.type == Op.Conv2DBackpropInputSwitchedBias: upscaling_factor = op.outputs[0].shape[1] // input_shape[1] padding, skirt = calc_upscaled_padding_and_skirt( op.attrs["padding"], kernel_size, op.attrs["strides"], input_shape, upscaling_factor ) else: dilation_h, dilation_w = op.get_dilation_h_w() dilated_kernel_size = [dilation_h * (kernel_size[0] - 1) + 1, dilation_w * (kernel_size[1] - 1) + 1] padding, skirt = calc_padding_and_skirt( op.attrs["padding"], dilated_kernel_size, op.attrs["strides"], input_shape ) op.attrs["explicit_padding"] = padding op.attrs["skirt"] = skirt return op # Check if the op can be reordered def get_prepend_op(op): inp = op.inputs[0] # The op should be reordered between prev_op and prep_op prev_op = inp.ops[-1] prep_op = None while prev_op.type in memory_only_ops and len(prev_op.outputs) == 1 and len(prev_op.outputs[0].consumers()) == 1: prep_op = prev_op inp = prev_op.inputs[0] prev_op = inp.ops[-1] if prev_op is not None and len(prev_op.outputs) == 1 and len(prev_op.outputs[0].consumers()) == 1: return prep_op return None def convert_depthwise_to_conv(op, arch, nng): # Depthwise is equivalent to a single conv2d if the ifm depth is 1 and # the ofm depth equals the depth multipler. # If those conditions are true, then we can perform a simple # switch of the operator type (and weight order) if op.type == Op.DepthwiseConv2DBias and (op.attrs["depth_multiplier"] != 1): ifm_tensor = op.inputs[0] weight_tensor = op.inputs[1] ofm_tensor = op.outputs[0] if (ifm_tensor.shape[3] == 1) and (ofm_tensor.shape[3] == op.attrs["depth_multiplier"]): # Change op type to Conv2d op.type = Op.Conv2DBias del op.attrs["channel_multiplier"] del op.attrs["depth_multiplier"] weight_tensor.quant_values = np.transpose(weight_tensor.quant_values, (0, 1, 3, 2)) weight_tensor.set_all_shapes(list(weight_tensor.quant_values.shape)) else: raise UnsupportedFeatureError( "Unsupported DepthwiseConv2d with depth_multiplier = {}, ifm channels = {}, ofm channels = {}".format( op.attrs["depth_multiplier"], ifm_tensor.shape[3], ofm_tensor.shape[3] ) ) DebugDatabase.add_optimised(op, op) return op def reorder_depthwise_weights(op, arch, nng): if op.type.is_depthwise_conv2d_op(): weight_tensor = op.inputs[1] weight_tensor.quant_values = np.transpose(weight_tensor.quant_values, (0, 1, 3, 2)) weight_tensor.set_all_shapes(list(weight_tensor.quant_values.shape)) weight_tensor.weight_transpose_depthwise = True return op def convert_conv_to_fc(op, arch, nng): # Conv 1x1 can be equivalent to Fully Connected. # By representing certain convs as fully connected layers, Vela can better determine wether or not to use # caching/double buffering for the weights. # (Weights dont need to be reloaded for convs when IFM H and W are 1) if op.type == Op.Conv2DBias: _, h, w, _ = op.inputs[0].shape kh, kw, _, _ = op.inputs[1].shape if h == 1 and w == 1 and kh == 1 and kw == 1: # Overwrite this op as a Fully Connected Op op.name += "_fc" op.type = Op.FullyConnected op.attrs = { "weights_format": 0, } # Reshape Weights to be 2D. HWIO becomes just IO (as H and W are 1, they can just be dropped) weight_tensor = op.inputs[1] weight_tensor.quant_values = weight_tensor.quant_values.squeeze(axis=(0, 1)) weight_tensor.set_all_shapes(list(weight_tensor.quant_values.shape)) # The output from a fully connected is expected to be 2D so we need to add a reshape layer to convert it # back to 4D afterwards as the next layer is expecting that shape orig_ofm_tensor = op.outputs[0] # Reshape this ops output to be 2D: {(N*H*W), C} (We know N H and W are all 1 so this becomes {1, C}) fc_ofm_tensor = orig_ofm_tensor.clone("_fc") fc_ofm_tensor.set_all_shapes([1, fc_ofm_tensor.shape[-1]]) fc_ofm_tensor.ops = [op] # Add a reshape after the new OFM to convert it back to the original 4D shape reshape_name = op.name + "_reshape" new_shape_tens = create_const_tensor(reshape_name + "_shape", [1], DataType.int32, orig_ofm_tensor.shape) reshape_op = Operation(Op.Reshape, reshape_name) reshape_op.attrs["new_shape"] = orig_ofm_tensor.shape reshape_op.inputs = [fc_ofm_tensor, new_shape_tens] reshape_op.set_output_tensor(orig_ofm_tensor) # Replace this ops OFM to point to the 2D tensor op.outputs[0] = fc_ofm_tensor # Record optimisation in debug database DebugDatabase.add_optimised(op, reshape_op) DebugDatabase.add_optimised(op, op) return op def fixup_relus_with_differing_ifm_ofm_scaling(op, arch, nng): if op.run_on_npu and op.type.is_relu_op(): ifm = op.inputs[0] ofm = op.outputs[0] # Relu with differing IFM and OFM scaling cannot be fused with another primary op # and requires its own to be inserted if not check_quantized_tens_scaling_equal(ifm, ofm): # Override this op with its own primary op (avgpool) relu_fused_op = create_avgpool_nop(op.name + "_avgpool") # And fuse the original activation function to it relu_fused_op.activation = create_activation_function(op.type) # Tidy up and assign the ifm and ofm to the new op ifm.consumer_list.remove(op) # if not 4d, reshape ifm/ofm if len(ifm.shape) < 4: ifm_shaped = create_reshape_tensor(ifm, full_shape(4, ifm.shape, 1)) ifm = ifm_shaped if len(ofm.shape) < 4: ofm_shaped = create_reshape_tensor(ofm, full_shape(4, ofm.shape, 1), False) ofm = ofm_shaped relu_fused_op.add_input_tensor(ifm) relu_fused_op.set_output_tensor(ofm) op = relu_fused_op return op # Reorder activation op if it's after the memory only operations def fixup_act_reorder(op, arch, nng): if op.type.is_relu_op() or op.type in set((Op.Sigmoid, Op.Tanh)): prep_op = get_prepend_op(op) if prep_op is not None: act_op = op.clone("_reordered") # There is only one input tensor, overwrite it act_op.set_input_tensor(prep_op.inputs[0], 0) act_op_out = act_op.inputs[0].clone("_acted") act_op_out.quantization = op.outputs[0].quantization.clone() act_op.set_output_tensor(act_op_out) # Update the consumer list act_op_out.consumer_list = op.outputs[0].consumer_list.copy() act_op_out.consumer_list.append(prep_op) prep_op.inputs[0] = act_op_out prep_op.outputs[0].quantization = act_op_out.quantization.clone() # Mark the op so that it will be removed as passthrough later on op.type = Op.Identity # Record optimisation in debug database DebugDatabase.add_optimised(op, act_op) DebugDatabase.add_optimised(op, op) return op def fixup_elementwise_with_scalars(op, arch, nng): if op.type.is_binary_elementwise_op(): ifm_tensor, ifm2_tensor, _, _ = op.get_ifm_ifm2_weights_ofm() if ifm2_tensor.shape != [] and ifm_tensor.shape != []: diff = len(ifm_tensor.shape) - len(ifm2_tensor.shape) if diff > 0: ifm2_tensor.shape = full_shape(len(ifm_tensor.shape), ifm2_tensor.shape, 1) elif diff < 0: ifm_tensor.shape = full_shape(len(ifm2_tensor.shape), ifm_tensor.shape, 1) elif ifm_tensor.shape == [] and ifm_tensor.quant_values is None: # IFM is marked as a scalar, but is a result of an operation; change it to a shape of size 1 ifm_tensor.shape = len(ifm2_tensor.shape) * [1] ifm_tensor.storage_shape = ifm_tensor.shape elif ifm2_tensor.shape == [] and ifm2_tensor.quant_values is None: # IFM2 is marked as a scalar, but is a result of an operation; change it to a shape of size 1 ifm2_tensor.shape = len(ifm_tensor.shape) * [1] ifm2_tensor.storage_shape = ifm2_tensor.shape return op # Set input/output tensor equivalence to the same id for memory operations def set_tensor_equivalence(op, arch, nng): if op.type in memory_only_ops: eid = op.outputs[0].equivalence_id for inp in op.inputs: inp.equivalence_id = eid return op def convert_softmax(op, arch, nng): if op.type == Op.Softmax and op.run_on_npu: softmax = SoftMax(op) op = softmax.get_graph() return op def convert_mul_max_to_abs_or_lrelu(op, arch, nng): r"""Whenever there is a subgraph with this topology: Input X For X = -1 or X > 0 | \ / This subgraph can be replaced with either | Mul an Abs (if X = -1) or a LeakyReLU (if X > 0) | / Max """ if op.type == Op.Maximum: # finds the Mul input(s) to the Max muls = [i for i in op.inputs if i.ops[0].type == Op.Mul] if len(muls) == 1: mul = muls[0].ops[0] elif len(muls) == 2: # In the case both inputs are Muls, find the one with the same input as the Max mul = [m for m in muls if len(set(op.inputs + m.ops[0].inputs)) == 1][0].ops[0] else: # No Mul inputs return op # make sure the Mul doesn't have any other consumers mul_ofm = mul.outputs[0] if len(mul_ofm.consumers()) != 1: return op # make sure the Mul doesn't have a fused activation function if mul.activation: return op ifm, ofm = op.get_ifm_ofm() if ifm is None or ofm is None: return op if ifm.dtype not in (DataType.uint8, DataType.int8) or ifm.dtype != ofm.dtype: return op if not check_quantized_tens_scaling_equal(ifm, ofm) or not check_quantized_tens_scaling_equal(ifm, mul_ofm): # rewrite to LeakyRelu currently only makes sense if the quantization is identical return op # finds the branched input that goes to both the Max and the Mul shared = set(op.inputs) & set(mul.inputs) if len(shared) == 1: shared_in = shared.pop() # find the constant scalar input to the Mul const_tens = (set(mul.inputs) - {shared_in}).pop() # check that it is a scalar if const_tens.shape != []: return op const = const_tens.ops[0] # check that it is a constant if const.type != Op.Const: return op # Remove the Mul from the shared input's consumers shared_in.consumer_list.remove(mul) else: return op val = const.outputs[0].values if val >= 0: new_op = Op.LeakyRelu op.attrs["alpha"] = val # to produce bit exact results, the alpha is not enough; # save additional scaling info in attr "alpha_scale", to be used as input # to the LUT construction alpha_scalar = const_tens.quant_values - const_tens.quantization.zero_point mul_ifm_scale = np.double(ifm.quantization.scale_f32) mul_ifm2_scale = np.double(const_tens.quantization.scale_f32) mul_ofm_scale = np.double(mul_ofm.quantization.scale_f32) alpha_scale, alpha_shift = scaling.elementwise_mul_scale(mul_ifm_scale, mul_ifm2_scale, mul_ofm_scale) op.attrs["alpha_scaling"] = (alpha_scalar, alpha_scale, alpha_shift) elif val == -1: new_op = Op.Abs else: return op op.type = new_op op.name = op.name.replace("Maximum", new_op.name) op.outputs[0].name = op.outputs[0].name.replace("Maximum", new_op.name) op.inputs = [shared_in] # Record optimisation in debug database DebugDatabase.add_optimised(op, op) return op def convert_lrelu_to_mul_max(op, arch): # Converts LeakyRelu to Max(alpha * IFM, identity * IFM) # (the opposite of convert_mul_max_to_abs_or_lrelu) ifm, ofm = op.get_ifm_ofm() if ifm is None or ofm is None: return op # Add multiplication with alpha mul_alpha = Operation(Op.Mul, op.name + "_mul_alpha") mul_alpha.add_input_tensor(ifm) # Create const tensor containing alpha as scalar alpha = op.attrs["alpha"] quantization = ifm.quantization.clone() quantization.min = 0 quantization.max = alpha * (quantization.quant_max - quantization.quant_min) quantization.scale_f32 = alpha quantization.zero_point = 0 alpha_tens = create_const_tensor(op.name + "_alpha_scalar", [], ifm.dtype, [1], np.int8, quantization=quantization) mul_alpha.add_input_tensor(alpha_tens) fm_alpha = ofm.clone(op.name + "_alpha") mul_alpha.set_output_tensor(fm_alpha) DebugDatabase.add_optimised(op, mul_alpha) if check_quantized_tens_scaling_equal(ifm, ofm): # No identity multiplication is needed fm_id = ifm else: # Add multiplication with identity mul_identity = Operation(Op.Mul, op.name + "_mul_identity") mul_identity.add_input_tensor(ifm) # Create const tensor containing identity as scalar quantization = ifm.quantization.clone() quantization.min = 0 quantization.max = quantization.quant_max - quantization.quant_min quantization.scale_f32 = 1 quantization.zero_point = 0 identity_tens = create_const_tensor( op.name + "_id_scalar", [], ifm.dtype, [1], np.uint8, quantization=quantization ) mul_identity.add_input_tensor(identity_tens) fm_id = ofm.clone(op.name + "_id") mul_identity.set_output_tensor(fm_id) DebugDatabase.add_optimised(op, mul_alpha) # Convert LeakyRelu to Max, add the results of the multiplication(s) as inputs op.type = Op.Maximum op.name = op.name.replace("LeakyRelu", "Maximum") op.inputs = [] ifm.consumer_list.remove(op) op.add_input_tensor(fm_alpha) op.add_input_tensor(fm_id) DebugDatabase.add_optimised(op, op) return op def convert_to_lut(op, lut_values, lut_name): # Rewrite the operation by Add with scalar 0 + LUT activation ifm = op.inputs[0] if ifm is None: return op assert ifm.dtype.size_in_bytes() == 1 op.type = Op.Add op.name = op.name + "_lut_" + lut_name # Mark as no-op to enable potential fusing optimizations op.attrs["is_nop"] = True # Create an input tensor containing scalar zero quantization = QuantizationParameters(0.0, 255.0) quantization.scale_f32 = ifm.quantization.scale_f32 quantization.zero_point = 0 tens = create_const_tensor(op.inputs[0].name + "_scalar0", [], ifm.dtype, [0], np.uint8, quantization=quantization) op.add_input_tensor(tens) # The LUT must be applied without any preceding rescaling (the LUT itself performs the rescale), # so even if the OFM has a different scale than the IFM, the generated OFM scale instructions # should be the same as the IFM op.forced_output_quantization = ifm.quantization lut_tensor = lut.create_lut_tensor(op.name + "_values", lut_values, DataType.int8) op.set_activation_lut(lut_tensor) return op def convert_to_lut8(op, fn, fn_name): # Converts op to a no-op + int8/uint8 LUT which is generated with the given function. # fn is a function(real) -> real ifm, ofm = op.get_ifm_ofm() if ifm.dtype not in (DataType.uint8, DataType.int8) or ifm.dtype != ofm.dtype: return op # Generate the LUT ifm_scale = np.double(ifm.quantization.scale_f32) ofm_scale = np.double(ofm.quantization.scale_f32) zp_in = ifm.quantization.zero_point zp_out = ofm.quantization.zero_point values = [] ix = range(256) if ifm.dtype == DataType.uint8 else range(-128, 128) quantized_min = min(ix) quantized_max = max(ix) for x in ix: x_real = ifm_scale * (x - zp_in) y_real = fn(x_real) lut_result = round_away_zero(zp_out + y_real / ofm_scale) lut_result = min(quantized_max, max(quantized_min, lut_result)) values.append(lut_result) return convert_to_lut(op, values, fn_name) def convert_lrelu_to_lut(op, arch): ifm, ofm = op.get_ifm_ofm() # Generate the LUT alpha = op.attrs["alpha"] ifm_scale = np.double(ifm.quantization.scale_f32) ofm_scale = np.double(ofm.quantization.scale_f32) zp_in = ifm.quantization.zero_point zp_out = ofm.quantization.zero_point identity_scale, identity_shift = scaling.elementwise_mul_scale(ifm_scale, 1, ofm_scale) alpha_scalar = 1 alpha_scale, alpha_shift = scaling.elementwise_mul_scale(ifm_scale, alpha, ofm_scale) if "alpha_scaling" in op.attrs: # The LeakyRelu was the result from convert_mul_max_to_abs_or_lrelu alpha_scalar, alpha_scale, alpha_shift = op.attrs["alpha_scaling"] values = [] ix = range(256) if ifm.dtype == DataType.uint8 else range(-128, 128) quantized_min = min(ix) quantized_max = max(ix) for x in ix: if x < zp_in: lut_result = zp_out + fp_math.multiply_by_quantized_multiplier( alpha_scalar * (x - zp_in), alpha_scale, alpha_shift ) else: lut_result = zp_out + fp_math.multiply_by_quantized_multiplier(x - zp_in, identity_scale, identity_shift) lut_result = min(quantized_max, max(quantized_min, lut_result)) values.append(lut_result) return convert_to_lut(op, values, "lrelu") def convert_lrelu(op, arch, nng): # Converts LeakyRelu to a LUT based solution if possible, otherwise a mul + max if op.type != Op.LeakyRelu: return op ifm, ofm = op.get_ifm_ofm() if ifm is None or ofm is None: return op if ifm.dtype in (DataType.uint8, DataType.int8) and ifm.dtype == ofm.dtype: # use LUT for int8/uint8 return convert_lrelu_to_lut(op, arch) if check_quantized_tens_scaling_equal(ifm, ofm) and ifm.dtype == ofm.dtype == DataType.int16: # use LeakyRelu unmodified for int16 with equal input/output scaling return op return convert_lrelu_to_mul_max(op, arch) def convert_tanh_sigmoid_to_lut(op, arch, nng): # Converts int8/uint8 Sigmoid and Tanh to a LUT based solution if op.type == Op.Sigmoid: return convert_to_lut8(op, clamp_sigmoid, "sigmoid") elif op.type == Op.Tanh: return convert_to_lut8(op, math.tanh, "tanh") return op def remove_unwanted_reshapes(op, arch, nng): # Try to remove reshapes enclosing ElementWise operator with only one non-constant input if not op.run_on_npu or not op.type.is_elementwise_op(): return op # Check if the ElementWise operator only have one non-constant input non_const_tens = [x for x in op.inputs if x.ops[0].type != Op.Const] if len(non_const_tens) != 1: return op ifm = non_const_tens[0] # Check if operation is enclosed by Reshapes that can be removed ofm = op.outputs[0] prev_op = ifm.ops[0] if ( len(ifm.consumer_list) == 1 and prev_op.type == Op.Reshape and len(ofm.consumer_list) == 1 and ofm.consumer_list[0].type == Op.Reshape ): # Operation is enclosed by reshapes, check if they can be removed prev_op_ifm, prev_op_ofm = prev_op.get_ifm_ofm() cons_op = ofm.consumer_list[0] cons_op_ifm = ofm cons_op_ofm = cons_op.outputs[0] if len(prev_op_ifm.shape) == len(cons_op_ofm.shape): # Check if quantization is the same in the input and output for the reshape ops if check_quantized_tens_scaling_equal(prev_op_ifm, prev_op_ofm) and check_quantized_tens_scaling_equal( cons_op_ifm, cons_op_ofm ): op.set_input_tensor(prev_op_ifm, 0) op.set_output_tensor(cons_op_ofm) return op def fuse_activation_function_with_prev(op, arch, nng): # if op is a no-op: attempts to move the activation function to the preceding op if not op.attrs.get("is_nop", False) or op.activation is None: return op ifm, ofm = op.get_ifm_ofm() if ifm is None or ofm is None: return op # finds the input(s) to the operation prev_op = ifm.ops[0] # Note: the below checks on prev_op require that a first optimize pass on the full graph has been performed fuse = ( prev_op.run_on_npu and prev_op.type.npu_block_type != NpuBlockType.Default and len(ifm.ops) == 1 and len(prev_op.outputs[0].consumers()) == 1 and prev_op.activation is None ) if op.activation_lut is not None and arch.shram_reserved_unused_banks == 0: # TODO: if SHRAM LUT space is shared with SHRAM ACC (32, 64 MAC), # LUT currently only works correctly for elementwise ops fuse = False if not fuse: return op # Move the fused activation function + corresponding info to prev_op prev_op.activation = op.activation prev_op.forced_output_quantization = op.forced_output_quantization if op.activation_lut is not None: prev_op.set_activation_lut(op.activation_lut) # Bypass op prev_op.set_output_tensor(ofm) DebugDatabase.add_optimised(op, prev_op) return op def add_attrs_to_resizebilinear(op, arch, nng): if op.type == Op.ResizeBilinear and op.run_on_npu: input_tensor = op.inputs[0] upscaled_shape = [input_tensor.shape[1] * 2, input_tensor.shape[2] * 2] out_shape = op.outputs[0].shape[1:3] if not op.attrs["align_corners"] and out_shape == upscaled_shape: # this means the output is supposed to be a x2 upscale, # so we need to do SAME padding op.attrs["padding"] = b"SAME" elif op.attrs["align_corners"] and out_shape == [upscaled_shape[0] - 1, upscaled_shape[1] - 1]: # here we can just run the avg pool without padding and # produce a (M * 2 - 1, N * 2 - 1) sized output op.attrs["padding"] = b"VALID" else: return op input_tensor.resampling_mode = resampling_mode.NEAREST op.attrs.update({"strides": (1, 1, 1, 1), "ksize": (1, 2, 2, 1)}) return op def fixup_bias_tensors(op, arch, nng): if op.type.needs_bias() and op.bias is None: # Op has no bias, add bias tensor filled with zeros nr_biases = op.inputs[1].shape[-1] bias_values = [0] * nr_biases bias_tensor = create_const_tensor(op.name + "_bias", [nr_biases], DataType.int32, bias_values) bias_tensor.quant_values = bias_tensor.values op.set_input_tensor(bias_tensor, -1) return op def supported_operator_check(op, arch, nng): op.run_on_npu = arch.supported_operators.is_operator_supported(op) return op def _record_optimised(op, arch): if op.type != Op.Const: DebugDatabase.add_optimised(op, op) def optimise_graph_a(nng, arch, verbose_graph=False): if verbose_graph: nng.print_graph() op_rewrite_list = [ set_tensor_equivalence, supported_operator_check, # then do any rewrites of supported operators convert_depthwise_to_conv, convert_conv_to_fc, convert_softmax, fixup_fully_connected_input, convert_batched_fc_shape, fixup_pack_input, unfuse_activation_function, fixup_conv2d_backprop, fixup_relus_with_differing_ifm_ofm_scaling, fixup_act_reorder, fixup_elementwise_with_scalars, reorder_depthwise_weights, fixup_resizebilinear, fixup_bias_tensors, convert_nop_split_to_identity, convert_mul_max_to_abs_or_lrelu, remove_unwanted_reshapes, convert_lrelu, convert_tanh_sigmoid_to_lut, ] for idx, sg in enumerate(nng.subgraphs): # rewrite graph pass nng.subgraphs[idx] = rewrite_graph.rewrite_graph_pre_order( nng, sg, arch, [], op_rewrite_list, rewrite_unsupported=False, ) for idx, sg in enumerate(nng.subgraphs): # remove passthrough tensors and attempt further optimizations nng.subgraphs[idx] = rewrite_graph.rewrite_graph_pre_order( nng, sg, arch, [remove_passthrough_tensor], [fuse_activation_function_with_prev, add_padding_fields] ) # Post-optimisation operator debug tracing for sg in nng.subgraphs: rewrite_graph.visit_graph_post_order(sg.output_tensors, arch, [], [_record_optimised]) if verbose_graph: nng.print_graph() return nng def optimise_graph_b(nng, arch, verbose_graph=False): if verbose_graph: nng.print_graph() for idx, sg in enumerate(nng.subgraphs): # combined rewrite graph pass nng.subgraphs[idx] = rewrite_graph.rewrite_graph_pre_order( nng, sg, arch, [fixup_unpack_output, fixup_stridedslice_output, rewrite_concat, rewrite_split], [] ) if verbose_graph: nng.print_graph() return nng