python/serializer/tosa_serializer.py

# Copyright (c) 2020-2022, ARM Limited.
#
#    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
#
#         http://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.

import os
import json
import flatbuffers
import numpy as np
import struct
from enum import IntEnum, unique
from tosa import (
    TosaGraph,
    TosaBasicBlock,
    TosaTensor,
    TosaOperator,
    Version,
)
import tosa.DType as TosaDType
import tosa.Op as TosaOp

# Keep version number in sync with the version default value with schema/tosa.fbs
TOSA_VERSION_MAJOR = 0
TOSA_VERSION_MINOR = 41
TOSA_VERSION_PATCH = 0
TOSA_VERSION_DRAFT = True
TOSA_VERSION = [
    TOSA_VERSION_MAJOR,
    TOSA_VERSION_MINOR,
    TOSA_VERSION_PATCH,
    TOSA_VERSION_DRAFT,
]

# File identifier needs to be kept in sync with schema/tosa.fbs
TOSA_GRAPH_IDENTIFIER = b"\x54\x4F\x53\x41"

# With the way flatc generates its python types, there is no programatic way
# to get string names for the integer types.  Manually maintain a string table
# here.
DType = TosaDType.DType()
DTypeNames = [
    "UNKNOWN",
    "BOOL",
    "UINT8",
    "INT4",
    "INT8",
    "INT16",
    "INT32",
    "INT48",
    "FLOAT",
    "UINT16",
]

ByteMask = np.uint64(0xFF)


def dtype_str_to_val(name):

    for i in range(len(DTypeNames)):
        if name.casefold() == DTypeNames[i].casefold():
            return i
    raise Exception("Unable to parse DType name {}".format(name))


class TosaSerializerUnion:
    """This class handles encapsulating and serializing union types into flatbuffers"""

    def __init__(self):

        # A tuple of the start and end functions.
        # Set by the options constructors below
        self.optFcns = None

        # The type from the tosa.Options enumeration.
        # Set by the options constructors below.
        self.utype = None

        # Each of these lists is a tuple of the add function and the
        # value being added.  Set by the options constructors below.
        self.ints = []
        self.bools = []
        self.floats = []
        self.strings = []
        self.int16vecs = []
        self.intvecs = []
        self.fpvecs = []

    def serialize(self, builder):

        # We have to build strings and vectors first
        strList = []
        intVecList = []
        fpVecList = []

        for fcn, val in self.strings:
            strList.append((fcn, builder.CreateString(val)))

        for fcn, val in self.intvecs:
            intVecList.append((fcn, TosaSerializer.serializeInt32Vec(builder, val)))

        for fcn, val in self.int16vecs:
            intVecList.append((fcn, TosaSerializer.serializeInt16Vec(builder, val)))

        for fcn, val in self.fpvecs:
            fpVecList.append((fcn, TosaSerializer.serializeFpVec(builder, val)))

        startFcn, endFcn = self.optFcns

        # Then serialize the options object from the list of primitives and
        # other serialized values
        startFcn(builder)
        for fcn, val in self.ints:
            fcn(builder, val)

        for fcn, val in self.bools:
            fcn(builder, val)

        for fcn, val in self.floats:
            fcn(builder, val)

        for fcn, val in strList:
            fcn(builder, val)

        for fcn, val in intVecList:
            fcn(builder, val)

        for fcn, val in fpVecList:
            fcn(builder, val)

        return endFcn(builder)


class TosaSerializerAttribute(TosaSerializerUnion):
    """This class handles encapsulating all of the enumerated types for attributes"""

    def __init__(self):
        super().__init__()

    def PoolAttribute(self, kernel, stride, pad, input_zp, output_zp):
        from tosa import PoolAttribute as a, Attribute

        self.utype = Attribute.Attribute().PoolAttribute

        self.optFcns = (a.Start, a.End)
        self.intvecs.append((a.AddPad, pad))
        self.intvecs.append((a.AddKernel, kernel))
        self.intvecs.append((a.AddStride, stride))
        self.ints.append((a.AddInputZp, input_zp))
        self.ints.append((a.AddOutputZp, output_zp))

    def ConvAttribute(self, pad, stride, dilation, input_zp, weight_zp):
        from tosa import ConvAttribute as a, Attribute

        self.utype = Attribute.Attribute().ConvAttribute
        self.optFcns = (a.Start, a.End)

        self.intvecs.append((a.AddPad, pad))
        self.intvecs.append((a.AddStride, stride))
        self.intvecs.append((a.AddDilation, dilation))
        self.ints.append((a.AddInputZp, input_zp))
        self.ints.append((a.AddWeightZp, weight_zp))

    def TransposeConvAttribute(self, outpad, stride, output_shape, input_zp, weight_zp):
        from tosa import TransposeConvAttribute as a, Attribute

        self.utype = Attribute.Attribute().TransposeConvAttribute
        self.optFcns = (a.Start, a.End)

        self.intvecs.append((a.AddOutPad, outpad))
        self.intvecs.append((a.AddStride, stride))
        self.intvecs.append((a.AddOutputShape, output_shape))
        self.ints.append((a.AddInputZp, input_zp))
        self.ints.append((a.AddWeightZp, weight_zp))

    def PadAttribute(self, padding, pad_const_int, pad_const_fp):
        from tosa import PadAttribute as a, Attribute

        self.utype = Attribute.Attribute().PadAttribute
        self.optFcns = (a.Start, a.End)

        self.intvecs.append((a.AddPadding, padding))
        self.ints.append((a.AddPadConstInt, pad_const_int))
        self.floats.append((a.AddPadConstFp, pad_const_fp))

    def AxisAttribute(self, axis):
        from tosa import AxisAttribute as a, Attribute

        self.utype = Attribute.Attribute().AxisAttribute
        self.optFcns = (a.Start, a.End)

        self.ints.append((a.AddAxis, axis))

    def ReshapeAttribute(self, new_shape):
        from tosa import ReshapeAttribute as a, Attribute

        self.utype = Attribute.Attribute().ReshapeAttribute
        self.optFcns = (a.Start, a.End)

        self.intvecs.append((a.AddNewShape, new_shape))

    def SliceAttribute(self, start, size):
        from tosa import SliceAttribute as a, Attribute

        self.utype = Attribute.Attribute().SliceAttribute
        self.optFcns = (a.Start, a.End)

        self.intvecs.append((a.AddStart, start))
        self.intvecs.append((a.AddSize, size))

    def TileAttribute(self, multiples):
        from tosa import TileAttribute as a, Attribute

        self.utype = Attribute.Attribute().TileAttribute
        self.optFcns = (a.Start, a.End)

        self.intvecs.append((a.AddMultiples, multiples))

    def ResizeAttribute(self, scale, offset, border, mode):
        from tosa import ResizeAttribute as a, Attribute

        self.utype = Attribute.Attribute().ResizeAttribute
        self.optFcns = (a.Start, a.End)

        self.int16vecs.append((a.AddScale, scale))
        self.int16vecs.append((a.AddOffset, offset))
        self.int16vecs.append((a.AddBorder, border))
        self.ints.append((a.AddMode, mode))

    def ClampAttribute(self, minint, maxint, minfp, maxfp):
        from tosa import ClampAttribute as a, Attribute

        self.utype = Attribute.Attribute().ClampAttribute
        self.optFcns = (a.Start, a.End)

        self.ints.append((a.AddMinInt, minint))
        self.ints.append((a.AddMaxInt, maxint))

        self.ints.append((a.AddMinFp, minfp))
        self.ints.append((a.AddMaxFp, maxfp))

    def RescaleAttribute(
        self, input_zp, output_zp, multiplier, shift, scale32, double_round, per_channel
    ):
        from tosa import RescaleAttribute as a, Attribute

        self.utype = Attribute.Attribute().RescaleAttribute
        self.optFcns = (a.Start, a.End)

        self.ints.append((a.AddInputZp, input_zp))
        self.ints.append((a.AddOutputZp, output_zp))
        self.intvecs.append((a.AddMultiplier, multiplier))
        self.intvecs.append((a.AddShift, shift))
        self.bools.append((a.AddScale32, scale32))
        self.bools.append((a.AddDoubleRound, double_round))
        self.bools.append((a.AddPerChannel, per_channel))

    def MulAttribute(self, shift):
        from tosa import MulAttribute as a, Attribute

        self.utype = Attribute.Attribute().MulAttribute
        self.optFcns = (a.Start, a.End)

        self.ints.append((a.AddShift, shift))

    def ArithmeticRightShiftAttribute(self, round):
        from tosa import ArithmeticRightShiftAttribute as a, Attribute

        self.utype = Attribute.Attribute().ArithmeticRightShiftAttribute
        self.optFcns = (
            a.Start,
            a.End,
        )

        self.bools.append((a.AddRound, round))

    def CondIfAttribute(self, then_branch, else_branch):
        from tosa import CondIfAttribute as a, Attribute

        self.utype = Attribute.Attribute().CondIfAttribute
        self.optFcns = (a.Start, a.End)

        self.strings.append((a.AddThenBranch, then_branch))
        self.strings.append((a.AddElseBranch, else_branch))

    def WhileLoopAttribute(self, cond_branch, body_branch):
        from tosa import WhileLoopAttribute as a, Attribute

        self.utype = Attribute.Attribute().WhileLoopAttribute
        self.optFcns = (a.Start, a.End)

        self.strings.append((a.AddCondBranch, cond_branch))
        self.strings.append((a.AddBodyBranch, body_branch))

    def TransposeAttribute(self, perms):
        from tosa import TransposeAttribute as a, Attribute

        self.utype = Attribute.Attribute().TransposeAttribute
        self.optFcns = (a.Start, a.End)

        self.intvecs.append((a.AddPerms, perms))

    def TableAttribute(self, table):
        from tosa import TableAttribute as a, Attribute

        self.utype = Attribute.Attribute().TableAttribute
        self.optFcns = (a.Start, a.End)

        self.intvecs.append((a.AddTable, table))

    def MatMulAttribute(self, A_zp, B_zp):
        from tosa import MatMulAttribute as a, Attribute

        self.utype = Attribute.Attribute().MatMulAttribute
        self.optFcns = (a.Start, a.End)

        self.ints.append((a.AddAZp, A_zp))
        self.ints.append((a.AddBZp, B_zp))

    def FullyConnectedAttribute(self, input_zp, weight_zp):
        from tosa import FullyConnectedAttribute as a, Attribute

        self.utype = Attribute.Attribute().FullyConnectedAttribute
        self.optFcns = (a.Start, a.End)

        self.ints.append((a.AddInputZp, input_zp))
        self.ints.append((a.AddWeightZp, weight_zp))

    def NegateAttribute(self, input1_zp, output_zp):
        from tosa import NegateAttribute as a, Attribute

        self.utype = Attribute.Attribute().NegateAttribute
        self.optFcns = (a.Start, a.End)

        self.ints.append((a.AddInput1Zp, input1_zp))
        self.ints.append((a.AddOutputZp, output_zp))


class TosaSerializerTensor:
    def __init__(
        self,
        name,
        shape,
        dtype,
        data=None,
        placeholderFilename=None,
    ):
        self.name = name

        if isinstance(shape, np.ndarray):
            shape = shape.astype(int).tolist()
        shape = list(map(int, shape))

        self.shape = shape
        self.dtype = dtype

        if dtype == DType.FLOAT:
            fntype = np.float32
        else:
            fntype = int

        if isinstance(data, np.ndarray):
            data = data.flatten().astype(fntype).tolist()
            data = list(map(fntype, data))
            self.data = data
        elif isinstance(data, list):
            data = list(map(fntype, data))
            self.data = data
        else:
            self.data = None

        # Filename for placeholder tensors.  These get generated by the test generation
        # process and are written to disk, but are considered input tensors by the
        # network so they do not appear in the TOSA serialiazation.  However, if we
        # want to form a unit test around these input tensors, we can get the filename
        # from here.
        self.placeholderFilename = placeholderFilename

    def __str__(self):
        str = "TosaSerializerTensor name: {} shape: {} dtype: {}".format(
            self.name,
            self.shape,
            DTypeNames[self.dtype],
        )
        return str

    def setDtype(self, dtype):
        self.dtype = dtype

    def serialize(self, builder):
        fb_name = builder.CreateString(self.name)
        fb_shapes = TosaSerializer.serializeInt32Vec(builder, self.shape)
        if self.data:
            u8_data = list()
            # little endianess
            if self.dtype == DType.BOOL:
                for val in self.data:
                    val_u8 = np.uint8(val)
                    u8_data.append(val_u8)
            elif self.dtype == DType.INT4:
                in_size = len(self.data)
                out_size = (in_size + 1) // 2
                for i in range(out_size):
                    val_0 = self.data[2 * i]
                    if (2 * i + 1) < in_size:
                        val_1 = self.data[2 * i + 1]
                    else:
                        val_1 = 0
                    val_i8 = (val_0 & 0xF) | ((val_1 & 0xF) << 4)
                    val_u8 = np.uint8(val_i8)
                    u8_data.append(val_u8)
            elif self.dtype == DType.INT8:
                for val in self.data:
                    val_u8 = np.uint8(val)
                    u8_data.append(val_u8)
            elif self.dtype == DType.INT16:
                for val in self.data:
                    val_u16 = np.uint16(val)
                    b0 = val_u16 & ByteMask
                    b1 = (val_u16 >> np.uint16(8)) & ByteMask
                    u8_data.extend([b0, b1])
            elif self.dtype == DType.INT32:
                for val in self.data:
                    val_u32 = np.uint32(val)
                    b0 = val_u32 & ByteMask
                    b1 = (val_u32 >> np.uint32(8)) & ByteMask
                    b2 = (val_u32 >> np.uint32(16)) & ByteMask
                    b3 = (val_u32 >> np.uint32(24)) & ByteMask
                    u8_data.extend([b0, b1, b2, b3])
            elif self.dtype == DType.INT48:
                for val in self.data:
                    val_u64 = np.uint64(val)
                    b0 = val_u64 & ByteMask
                    b1 = (val_u64 >> np.uint64(8)) & ByteMask
                    b2 = (val_u64 >> np.uint64(16)) & ByteMask
                    b3 = (val_u64 >> np.uint64(24)) & ByteMask
                    b4 = (val_u64 >> np.uint64(32)) & ByteMask
                    b5 = (val_u64 >> np.uint64(40)) & ByteMask
                    u8_data.extend([b0, b1, b2, b3, b4, b5])
            elif self.dtype == DType.FLOAT:
                for val in self.data:
                    b = struct.pack("!f", val)
                    u8_data.extend([b[3], b[2], b[1], b[0]])
            else:
                raise Exception(
                    "unsupported data type {}".format(DTypeNames[self.dtype])
                )
            fb_data = TosaSerializer.serializeUint8Vec(builder, u8_data)

        TosaTensor.Start(builder)
        TosaTensor.AddName(builder, fb_name)
        TosaTensor.AddShape(builder, fb_shapes)
        TosaTensor.AddType(builder, self.dtype)
        if self.data:
            TosaTensor.AddData(builder, fb_data)

        return TosaTensor.End(builder)


class TosaSerializerOperator:
    def __init__(self, op, inputs, outputs, attributes=None):
        self.op = op
        self.attributes = attributes
        self.inputs = TosaSerializer.toList(inputs)
        self.outputs = TosaSerializer.toList(outputs)

    def __str__(self):
        str = "Op {}\n----\n".format(self.op)

        for i in self.inputs:
            str = str + "  Input:  {}\n".format(i)
        for o in self.outputs:
            str = str + "  Output: {}\n".format(o)

        return str

    def serialize(self, builder):
        fb_inputs = TosaSerializer.serializeStrVec(
            builder, self.inputs, TosaOperator.StartInputsVector
        )
        fb_outputs = TosaSerializer.serializeStrVec(
            builder, self.outputs, TosaOperator.StartOutputsVector
        )
        # Need to serialize attributes enums still
        if self.attributes is not None:
            fb_attributes = self.attributes.serialize(builder)

        TosaOperator.Start(builder)
        TosaOperator.AddOp(builder, self.op)
        TosaOperator.AddInputs(builder, fb_inputs)
        TosaOperator.AddOutputs(builder, fb_outputs)
        if self.attributes is not None:
            TosaOperator.AddAttributeType(builder, self.attributes.utype)
            TosaOperator.AddAttribute(builder, fb_attributes)

        return TosaOperator.End(builder)


class TosaSerializerBasicBlock:
    def __init__(self, name):
        self.name = name
        self.operators = []

        # Dict assures uniqueness, but allows us to look up by name
        self.tensors = dict()

        self.inputs = []
        self.outputs = []

    def addTensor(
        self,
        name,
        shape,
        dtype,
        data=None,
        placeholderFilename=None,
    ):
        if name not in self.tensors:
            self.tensors[name] = TosaSerializerTensor(
                name, shape, dtype, data, placeholderFilename
            )

        return self.tensors[name]

    def addInput(self, name):
        self.inputs.append(name)

    def addOutput(self, name):
        self.outputs.append(name)

    def addOperator(self, op, inputs, outputs, attributes=None):
        self.operators.append(TosaSerializerOperator(op, inputs, outputs, attributes))

    def serialize(self, builder):
        fb_name = builder.CreateString(self.name)
        fbv_inputs = TosaSerializer.serializeStrVec(
            builder, list(self.inputs), TosaBasicBlock.StartInputsVector
        )
        fbv_outputs = TosaSerializer.serializeStrVec(
            builder, list(self.outputs), TosaBasicBlock.StartOutputsVector
        )
        fbv_tensors = TosaSerializer.serializeObjVec(
            builder,
            list(self.tensors.values()),
            TosaBasicBlock.StartTensorsVector,
        )
        fbv_operators = TosaSerializer.serializeObjVec(
            builder, self.operators, TosaBasicBlock.StartOperatorsVector
        )

        TosaBasicBlock.Start(builder)
        TosaBasicBlock.AddName(builder, fb_name)
        TosaBasicBlock.AddInputs(builder, fbv_inputs)
        TosaBasicBlock.AddOutputs(builder, fbv_outputs)
        TosaBasicBlock.AddTensors(builder, fbv_tensors)
        TosaBasicBlock.AddOperators(builder, fbv_operators)
        return TosaBasicBlock.End(builder)


@unique
class TensorDir(IntEnum):
    PLACEHOLDER = 0
    CONST = 1
    INTERMEDIATE = 2
    RESULT = 3


class TosaSerializer:
    def __init__(self, pathPrefix, saveConstsToFile=False):
        self.add_compat_methods()
        # Get the global TOSA version if not already defined

        self.builder = flatbuffers.Builder(0)

        self.basicBlocks = []
        self.startBasicBlock("main")
        self.pathPrefix = pathPrefix

        # Enables inspection of constant data outside of graph
        self.saveConstsToFile = saveConstsToFile

        # Indicies used for adding/naming tensors
        self.currInputIdx = 0
        self.currConstIdx = 0
        self.currLayerIdx = 1
        self.currResultIdx = 0

        # Is this an illegal test that is expected to fail?
        self.expectedReturnCode = 0
        self.expectedFailure = False
        self.expectedFailureDesc = ""

    def __str__(self):
        str = ""
        for bb in self.basicBlocks:
            str = str + bb.__str__()
        return str

    def addPlaceholder(self, shape, dtype, vals):
        if not self.currBasicBlock:
            raise Exception("addTensor called without valid basic block")

        name = "input-{}".format(self.currInputIdx)
        filename = "{}.npy".format(name)
        self.currInputIdx = self.currInputIdx + 1

        tens = self.currBasicBlock.addTensor(name, shape, dtype, None, filename)
        # This is always an input to the block
        self.currBasicBlock.addInput(name)

        if vals is not None:
            np.save(os.path.join(self.pathPrefix, filename), vals, False)

        return tens

    def addConst(self, shape, dtype, vals):
        if not self.currBasicBlock:
            raise Exception("addTensor called without valid basic block")

        name = "const-{}".format(self.currInputIdx)
        self.currInputIdx = self.currInputIdx + 1

        tens = self.currBasicBlock.addTensor(name, shape, dtype, vals)
        # Add the operator now
        self.currBasicBlock.addOperator(TosaOp.Op().CONST, [], name)

        if self.saveConstsToFile:
            filename = "{}.npy".format(name)
            np.save(os.path.join(self.pathPrefix, filename), vals, False)

        return tens

    def addIntermediate(self, shape, dtype):

        if not self.currBasicBlock:
            raise Exception("addTensor called without valid basic block")

        name = "layer-{}".format(self.currLayerIdx)
        self.currLayerIdx = self.currLayerIdx + 1

        tens = self.currBasicBlock.addTensor(name, shape, dtype, None)

        return tens

    def addInputTensor(self, tensor):
        self.currBasicBlock.addTensor(tensor.name, tensor.shape, tensor.dtype)
        self.currBasicBlock.addInput(tensor.name)

    def addOutputTensor(self, tensor):
        self.currBasicBlock.addOutput(tensor.name)

    def addOutput(self, shape, dtype):
        if not self.currBasicBlock:
            raise Exception("addTensor called without valid basic block")

        name = "result-{}".format(self.currResultIdx)
        self.currResultIdx = self.currResultIdx + 1

        tens = self.currBasicBlock.addTensor(name, shape, dtype, None)
        self.currBasicBlock.addOutput(name)
        return tens

    def addOperator(self, op, inputs, outputs, attributes=None):

        if op == TosaOp.Op().CONST:
            raise Exception("Use addConstTensor() to add CONST ops")

        return self.currBasicBlock.addOperator(
            op,
            inputs,
            outputs,
            attributes,
        )

    def setExpectedReturnCode(self, val, fail, desc=""):

        self.expectedReturnCode = val
        self.expectedFailureDesc = desc
        self.expectedFailure = fail

    def serialize(self):

        builder = self.builder

        Version.Start(builder)
        Version.Add_major(builder, TOSA_VERSION[0])
        Version.Add_minor(builder, TOSA_VERSION[1])
        Version.Add_patch(builder, TOSA_VERSION[2])
        Version.Add_draft(builder, TOSA_VERSION[3])
        version = Version.End(builder)

        fbv_bb = TosaSerializer.serializeObjVec(
            builder, self.basicBlocks, TosaGraph.StartBlocksVector
        )

        TosaGraph.Start(builder)
        TosaGraph.AddVersion(builder, version)
        TosaGraph.AddBlocks(builder, fbv_bb)
        graph = TosaGraph.End(builder)

        self.builder.Finish(graph, TOSA_GRAPH_IDENTIFIER)
        return self.builder.Output()

    def writeJson(self, tosa_filename):
        """Write a json test file so that it is fairly easy to pick up the test
        and generate commands for third party tool"""
        test_desc = dict()

        test_desc["tosa_file"] = tosa_filename
        ifm_name = []
        ifm_file = []
        ofm_name = []
        ofm_file = []

        for b in self.basicBlocks:
            if b.name == "main":
                for i in b.inputs:
                    ifm_name.append(i)
                    ifm_file.append(b.tensors[i].placeholderFilename)
                for o in b.outputs:
                    ofm_name.append(o)
                    # Make up an OFM filename here.  One isn't generated until the
                    # reference tool is run, so any name is a good name
                    ofm_file.append("ref-{}.npy".format(o))

        test_desc["ifm_name"] = ifm_name
        test_desc["ifm_file"] = ifm_file
        test_desc["ofm_name"] = ofm_name
        test_desc["ofm_file"] = ofm_file
        test_desc["expected_return_code"] = self.expectedReturnCode
        test_desc["expected_failure"] = self.expectedFailure
        if self.expectedFailureDesc:
            test_desc["expected_failure_desc"] = self.expectedFailureDesc

        return json.dumps(test_desc, indent="  ")

    def startBasicBlock(self, name):
        self.currBasicBlock = TosaSerializerBasicBlock(name)
        self.basicBlocks.append(self.currBasicBlock)

    @staticmethod
    def serializeStrVec(builder, vec, start_fcn):
        fb_strs = [builder.CreateString(i) for i in vec]
        start_fcn(builder, len(fb_strs))
        for s in fb_strs[::-1]:
            builder.PrependUOffsetTRelative(s)
        try:
            return builder.EndVector()
        except TypeError:
            return builder.EndVector(len(vec))

    @staticmethod
    def serializeUint8Vec(builder, vec):
        builder.StartVector(1, len(vec), 8)
        for v in vec[::-1]:
            builder.PrependUint8(v)
        try:
            return builder.EndVector()
        except TypeError:
            return builder.EndVector(len(vec))

    @staticmethod
    def serializeInt16Vec(builder, vec):
        builder.StartVector(2, len(vec), 4)
        for v in vec[::-1]:
            builder.PrependInt16(v)
        try:
            return builder.EndVector()
        except TypeError:
            return builder.EndVector(len(vec))

    @staticmethod
    def serializeInt32Vec(builder, vec):
        builder.StartVector(4, len(vec), 4)
        for v in vec[::-1]:
            builder.PrependInt32(v)
        try:
            return builder.EndVector()
        except TypeError:
            return builder.EndVector(len(vec))

    @staticmethod
    def serializeFpVec(builder, vec):
        builder.StartVector(4, len(vec), 4)
        for v in vec[::-1]:
            builder.PrependFloat32(v)
        try:
            return builder.EndVector()
        except TypeError:
            return builder.EndVector(len(vec))

    @staticmethod
    def serializeObjVec(builder, vec, start_fcn):
        serialized_vec = []
        for v in vec[::-1]:
            serialized_vec.append(v.serialize(builder))

        start_fcn(builder, len(vec))
        for v in serialized_vec:
            builder.PrependUOffsetTRelative(v)
        try:
            return builder.EndVector()
        except TypeError:
            return builder.EndVector(len(vec))

    @staticmethod
    def toList(val):
        if isinstance(val, list):
            return val
        else:
            return [val]

    # Remove when switching to flatbuffers 2.0
    # contains a mapping of the deprecated 1.12 method to the 2.0 version

    def add_compat_methods(self):

        from tosa import ArithmeticRightShiftAttribute

        if not hasattr(ArithmeticRightShiftAttribute, "Start"):
            ArithmeticRightShiftAttribute.Start = (
                ArithmeticRightShiftAttribute.ArithmeticRightShiftAttributeStart
            )
            ArithmeticRightShiftAttribute.AddRound = (
                ArithmeticRightShiftAttribute.ArithmeticRightShiftAttributeAddRound
            )
            ArithmeticRightShiftAttribute.End = (
                ArithmeticRightShiftAttribute.ArithmeticRightShiftAttributeEnd
            )
        from tosa import AxisAttribute

        if not hasattr(AxisAttribute, "Start"):
            AxisAttribute.Start = AxisAttribute.AxisAttributeStart
            AxisAttribute.AddAxis = AxisAttribute.AxisAttributeAddAxis
            AxisAttribute.End = AxisAttribute.AxisAttributeEnd
        from tosa import ClampAttribute

        if not hasattr(ClampAttribute, "Start"):
            ClampAttribute.Start = ClampAttribute.ClampAttributeStart
            ClampAttribute.AddMinInt = ClampAttribute.ClampAttributeAddMinInt
            ClampAttribute.AddMaxInt = ClampAttribute.ClampAttributeAddMaxInt
            ClampAttribute.AddMinFp = ClampAttribute.ClampAttributeAddMinFp
            ClampAttribute.AddMaxFp = ClampAttribute.ClampAttributeAddMaxFp
            ClampAttribute.End = ClampAttribute.ClampAttributeEnd
        from tosa import CondIfAttribute

        if not hasattr(CondIfAttribute, "Start"):
            CondIfAttribute.Start = CondIfAttribute.CondIfAttributeStart
            CondIfAttribute.AddThenBranch = CondIfAttribute.CondIfAttributeAddThenBranch
            CondIfAttribute.AddElseBranch = CondIfAttribute.CondIfAttributeAddElseBranch
            CondIfAttribute.End = CondIfAttribute.CondIfAttributeEnd
        from tosa import ConvAttribute

        if not hasattr(ConvAttribute, "Start"):
            ConvAttribute.Start = ConvAttribute.ConvAttributeStart
            ConvAttribute.AddPad = ConvAttribute.ConvAttributeAddPad
            ConvAttribute.StartPadVector = ConvAttribute.ConvAttributeStartPadVector
            ConvAttribute.AddStride = ConvAttribute.ConvAttributeAddStride
            ConvAttribute.StartStrideVector = (
                ConvAttribute.ConvAttributeStartStrideVector
            )
            ConvAttribute.AddDilation = ConvAttribute.ConvAttributeAddDilation
            ConvAttribute.StartDilationVector = (
                ConvAttribute.ConvAttributeStartDilationVector
            )
            ConvAttribute.AddInputZp = ConvAttribute.ConvAttributeAddInputZp
            ConvAttribute.AddWeightZp = ConvAttribute.ConvAttributeAddWeightZp
            ConvAttribute.End = ConvAttribute.ConvAttributeEnd
        from tosa import FullyConnectedAttribute

        if not hasattr(FullyConnectedAttribute, "Start"):
            FullyConnectedAttribute.Start = (
                FullyConnectedAttribute.FullyConnectedAttributeStart
            )
            FullyConnectedAttribute.AddInputZp = (
                FullyConnectedAttribute.FullyConnectedAttributeAddInputZp
            )
            FullyConnectedAttribute.AddWeightZp = (
                FullyConnectedAttribute.FullyConnectedAttributeAddWeightZp
            )
            FullyConnectedAttribute.End = (
                FullyConnectedAttribute.FullyConnectedAttributeEnd
            )
        from tosa import MatMulAttribute

        if not hasattr(MatMulAttribute, "Start"):
            MatMulAttribute.Start = MatMulAttribute.MatMulAttributeStart
            MatMulAttribute.AddAZp = MatMulAttribute.MatMulAttributeAddAZp
            MatMulAttribute.AddBZp = MatMulAttribute.MatMulAttributeAddBZp
            MatMulAttribute.End = MatMulAttribute.MatMulAttributeEnd
        from tosa import PoolAttribute

        if not hasattr(PoolAttribute, "Start"):
            PoolAttribute.Start = PoolAttribute.PoolAttributeStart
            PoolAttribute.AddPad = PoolAttribute.PoolAttributeAddPad
            PoolAttribute.StartPadVector = PoolAttribute.PoolAttributeStartPadVector
            PoolAttribute.AddKernel = PoolAttribute.PoolAttributeAddKernel
            PoolAttribute.StartKernelVector = (
                PoolAttribute.PoolAttributeStartKernelVector
            )
            PoolAttribute.AddStride = PoolAttribute.PoolAttributeAddStride
            PoolAttribute.StartStrideVector = (
                PoolAttribute.PoolAttributeStartStrideVector
            )
            PoolAttribute.AddInputZp = PoolAttribute.PoolAttributeAddInputZp
            PoolAttribute.AddOutputZp = PoolAttribute.PoolAttributeAddOutputZp
            PoolAttribute.End = PoolAttribute.PoolAttributeEnd
        from tosa import MulAttribute

        if not hasattr(MulAttribute, "Start"):
            MulAttribute.Start = MulAttribute.MulAttributeStart
            MulAttribute.AddShift = MulAttribute.MulAttributeAddShift
            MulAttribute.End = MulAttribute.MulAttributeEnd
        from tosa import PadAttribute

        if not hasattr(PadAttribute, "Start"):
            PadAttribute.Start = PadAttribute.PadAttributeStart
            PadAttribute.AddPadding = PadAttribute.PadAttributeAddPadding
            PadAttribute.StartPaddingVector = (
                PadAttribute.PadAttributeStartPaddingVector
            )
            PadAttribute.AddPadConstInt = PadAttribute.PadAttributeAddPadConstInt
            PadAttribute.AddPadConstFp = PadAttribute.PadAttributeAddPadConstFp
            PadAttribute.End = PadAttribute.PadAttributeEnd
        from tosa import PoolAttribute

        if not hasattr(PoolAttribute, "Start"):
            PoolAttribute.Start = PoolAttribute.PoolAttributeStart
            PoolAttribute.AddPad = PoolAttribute.PoolAttributeAddPad
            PoolAttribute.StartPadVector = PoolAttribute.PoolAttributeStartPadVector
            PoolAttribute.AddKernel = PoolAttribute.PoolAttributeAddKernel
            PoolAttribute.StartKernelVector = (
                PoolAttribute.PoolAttributeStartKernelVector
            )
            PoolAttribute.AddStride = PoolAttribute.PoolAttributeAddStride
            PoolAttribute.StartStrideVector = (
                PoolAttribute.PoolAttributeStartStrideVector
            )
            PoolAttribute.AddInputZp = PoolAttribute.PoolAttributeAddInputZp
            PoolAttribute.AddOutputZp = PoolAttribute.PoolAttributeAddOutputZp
            PoolAttribute.End = PoolAttribute.PoolAttributeEnd
        from tosa import RescaleAttribute

        if not hasattr(RescaleAttribute, "Start"):
            RescaleAttribute.Start = RescaleAttribute.RescaleAttributeStart
            RescaleAttribute.AddInputZp = RescaleAttribute.RescaleAttributeAddInputZp
            RescaleAttribute.AddOutputZp = RescaleAttribute.RescaleAttributeAddOutputZp
            RescaleAttribute.AddMultiplier = (
                RescaleAttribute.RescaleAttributeAddMultiplier
            )
            RescaleAttribute.StartMultiplierVector = (
                RescaleAttribute.RescaleAttributeStartMultiplierVector
            )
            RescaleAttribute.AddShift = RescaleAttribute.RescaleAttributeAddShift
            RescaleAttribute.StartShiftVector = (
                RescaleAttribute.RescaleAttributeStartShiftVector
            )
            RescaleAttribute.AddScale32 = RescaleAttribute.RescaleAttributeAddScale32
            RescaleAttribute.AddDoubleRound = (
                RescaleAttribute.RescaleAttributeAddDoubleRound
            )
            RescaleAttribute.AddPerChannel = (
                RescaleAttribute.RescaleAttributeAddPerChannel
            )
            RescaleAttribute.End = RescaleAttribute.RescaleAttributeEnd
        from tosa import ReshapeAttribute

        if not hasattr(ReshapeAttribute, "Start"):
            ReshapeAttribute.Start = ReshapeAttribute.ReshapeAttributeStart
            ReshapeAttribute.AddNewShape = ReshapeAttribute.ReshapeAttributeAddNewShape
            ReshapeAttribute.StartNewShapeVector = (
                ReshapeAttribute.ReshapeAttributeStartNewShapeVector
            )
            ReshapeAttribute.End = ReshapeAttribute.ReshapeAttributeEnd
        from tosa import ResizeAttribute

        if not hasattr(ResizeAttribute, "Start"):
            ResizeAttribute.Start = ResizeAttribute.ResizeAttributeStart
            ResizeAttribute.AddScale = ResizeAttribute.ResizeAttributeAddScale
            ResizeAttribute.StartScaleVector = (
                ResizeAttribute.ResizeAttributeStartScaleVector
            )
            ResizeAttribute.AddOffset = ResizeAttribute.ResizeAttributeAddOffset
            ResizeAttribute.StartOffsetVector = (
                ResizeAttribute.ResizeAttributeStartOffsetVector
            )
            ResizeAttribute.AddBorder = ResizeAttribute.ResizeAttributeAddBorder
            ResizeAttribute.StartBorderVector = (
                ResizeAttribute.ResizeAttributeStartBorderVector
            )
            ResizeAttribute.AddMode = ResizeAttribute.ResizeAttributeAddMode
            ResizeAttribute.End = ResizeAttribute.ResizeAttributeEnd
        from tosa import SliceAttribute

        if not hasattr(SliceAttribute, "Start"):
            SliceAttribute.Start = SliceAttribute.SliceAttributeStart
            SliceAttribute.AddStart = SliceAttribute.SliceAttributeAddStart
            SliceAttribute.StartStartVector = (
                SliceAttribute.SliceAttributeStartStartVector
            )
            SliceAttribute.AddSize = SliceAttribute.SliceAttributeAddSize
            SliceAttribute.StartSizeVector = (
                SliceAttribute.SliceAttributeStartSizeVector
            )
            SliceAttribute.End = SliceAttribute.SliceAttributeEnd
        from tosa import TableAttribute

        if not hasattr(TableAttribute, "Start"):
            TableAttribute.Start = TableAttribute.TableAttributeStart
            TableAttribute.AddTable = TableAttribute.TableAttributeAddTable
            TableAttribute.StartTableVector = (
                TableAttribute.TableAttributeStartTableVector
            )
            TableAttribute.End = TableAttribute.TableAttributeEnd
        from tosa import TileAttribute

        if not hasattr(TileAttribute, "Start"):
            TileAttribute.Start = TileAttribute.TileAttributeStart
            TileAttribute.AddMultiples = TileAttribute.TileAttributeAddMultiples
            TileAttribute.StartMultiplesVector = (
                TileAttribute.TileAttributeStartMultiplesVector
            )
            TileAttribute.End = TileAttribute.TileAttributeEnd
        from tosa import TosaBasicBlock

        if not hasattr(TosaBasicBlock, "Start"):
            TosaBasicBlock.Start = TosaBasicBlock.TosaBasicBlockStart
            TosaBasicBlock.AddName = TosaBasicBlock.TosaBasicBlockAddName
            TosaBasicBlock.AddOperators = TosaBasicBlock.TosaBasicBlockAddOperators
            TosaBasicBlock.StartOperatorsVector = (
                TosaBasicBlock.TosaBasicBlockStartOperatorsVector
            )
            TosaBasicBlock.AddTensors = TosaBasicBlock.TosaBasicBlockAddTensors
            TosaBasicBlock.StartTensorsVector = (
                TosaBasicBlock.TosaBasicBlockStartTensorsVector
            )
            TosaBasicBlock.AddInputs = TosaBasicBlock.TosaBasicBlockAddInputs
            TosaBasicBlock.StartInputsVector = (
                TosaBasicBlock.TosaBasicBlockStartInputsVector
            )
            TosaBasicBlock.AddOutputs = TosaBasicBlock.TosaBasicBlockAddOutputs
            TosaBasicBlock.StartOutputsVector = (
                TosaBasicBlock.TosaBasicBlockStartOutputsVector
            )
            TosaBasicBlock.End = TosaBasicBlock.TosaBasicBlockEnd
        from tosa import TosaGraph

        if not hasattr(TosaGraph, "Start"):
            TosaGraph.Start = TosaGraph.TosaGraphStart
            TosaGraph.AddVersion = TosaGraph.TosaGraphAddVersion
            TosaGraph.AddBlocks = TosaGraph.TosaGraphAddBlocks
            TosaGraph.StartBlocksVector = TosaGraph.TosaGraphStartBlocksVector
            TosaGraph.End = TosaGraph.TosaGraphEnd
        from tosa import TosaOperator

        if not hasattr(TosaOperator, "Start"):
            TosaOperator.Start = TosaOperator.TosaOperatorStart
            TosaOperator.AddOp = TosaOperator.TosaOperatorAddOp
            TosaOperator.AddAttributeType = TosaOperator.TosaOperatorAddAttributeType
            TosaOperator.AddAttribute = TosaOperator.TosaOperatorAddAttribute
            TosaOperator.AddInputs = TosaOperator.TosaOperatorAddInputs
            TosaOperator.StartInputsVector = TosaOperator.TosaOperatorStartInputsVector
            TosaOperator.AddOutputs = TosaOperator.TosaOperatorAddOutputs
            TosaOperator.StartOutputsVector = (
                TosaOperator.TosaOperatorStartOutputsVector
            )
            TosaOperator.End = TosaOperator.TosaOperatorEnd
        from tosa import TosaTensor

        if not hasattr(TosaTensor, "Start"):
            TosaTensor.Start = TosaTensor.TosaTensorStart
            TosaTensor.AddName = TosaTensor.TosaTensorAddName
            TosaTensor.AddShape = TosaTensor.TosaTensorAddShape
            TosaTensor.StartShapeVector = TosaTensor.TosaTensorStartShapeVector
            TosaTensor.AddType = TosaTensor.TosaTensorAddType
            TosaTensor.AddData = TosaTensor.TosaTensorAddData
            TosaTensor.StartDataVector = TosaTensor.TosaTensorStartDataVector
            TosaTensor.End = TosaTensor.TosaTensorEnd
        from tosa import TransposeAttribute

        if not hasattr(TransposeAttribute, "Start"):
            TransposeAttribute.Start = TransposeAttribute.TransposeAttributeStart
            TransposeAttribute.AddPerms = TransposeAttribute.TransposeAttributeAddPerms
            TransposeAttribute.StartPermsVector = (
                TransposeAttribute.TransposeAttributeStartPermsVector
            )
            TransposeAttribute.End = TransposeAttribute.TransposeAttributeEnd
        from tosa import TransposeConvAttribute

        if not hasattr(TransposeConvAttribute, "Start"):
            TransposeConvAttribute.Start = (
                TransposeConvAttribute.TransposeConvAttributeStart
            )
            TransposeConvAttribute.AddOutPad = (
                TransposeConvAttribute.TransposeConvAttributeAddOutPad
            )
            TransposeConvAttribute.StartOutPadVector = (
                TransposeConvAttribute.TransposeConvAttributeStartOutPadVector
            )
            TransposeConvAttribute.AddStride = (
                TransposeConvAttribute.TransposeConvAttributeAddStride
            )
            TransposeConvAttribute.StartStrideVector = (
                TransposeConvAttribute.TransposeConvAttributeStartStrideVector
            )
            TransposeConvAttribute.AddOutputShape = (
                TransposeConvAttribute.TransposeConvAttributeAddOutputShape
            )
            TransposeConvAttribute.StartOutputShapeVector = (
                TransposeConvAttribute.TransposeConvAttributeStartOutputShapeVector
            )
            TransposeConvAttribute.AddInputZp = (
                TransposeConvAttribute.TransposeConvAttributeAddInputZp
            )
            TransposeConvAttribute.AddWeightZp = (
                TransposeConvAttribute.TransposeConvAttributeAddWeightZp
            )
            TransposeConvAttribute.End = (
                TransposeConvAttribute.TransposeConvAttributeEnd
            )
        from tosa import Version

        if not hasattr(Version, "Start"):
            Version.Start = Version.VersionStart
            Version.Add_major = Version.VersionAdd_major
            Version.Add_minor = Version.VersionAdd_minor
            Version.Add_patch = Version.VersionAdd_patch
            Version.Add_draft = Version.VersionAdd_draft
            Version.End = Version.VersionEnd
        from tosa import MatMulAttribute

        if not hasattr(MatMulAttribute, "Start"):
            MatMulAttribute.Start = MatMulAttribute.MatMulAttributeStart
            MatMulAttribute.AddAZp = MatMulAttribute.MatMulAttributeAddAZp
            MatMulAttribute.AddBZp = MatMulAttribute.MatMulAttributeAddBZp
            MatMulAttribute.End = MatMulAttribute.MatMulAttributeEnd
        from tosa import FullyConnectedAttribute

        if not hasattr(FullyConnectedAttribute, "Start"):
            FullyConnectedAttribute.Start = (
                FullyConnectedAttribute.FullyConnectedAttributeStart
            )
            FullyConnectedAttribute.AddInputZp = (
                FullyConnectedAttribute.FullyConnectedAttributeAddInputZp
            )
            FullyConnectedAttribute.AddWeightZp = (
                FullyConnectedAttribute.FullyConnectedAttributeAddWeightZp
            )
            FullyConnectedAttribute.End = (
                FullyConnectedAttribute.FullyConnectedAttributeEnd
            )
        from tosa import NegateAttribute

        if not hasattr(NegateAttribute, "Start"):
            NegateAttribute.Start = NegateAttribute.NegateAttributeStart
            NegateAttribute.AddInput1Zp = NegateAttribute.NegateAttributeAddInput1Zp
            NegateAttribute.AddOutputZp = NegateAttribute.NegateAttributeAddOutputZp
            NegateAttribute.End = NegateAttribute.NegateAttributeEnd
        from tosa import WhileLoopAttribute

        if not hasattr(WhileLoopAttribute, "Start"):
            WhileLoopAttribute.Start = WhileLoopAttribute.WhileLoopAttributeStart
            WhileLoopAttribute.AddCondBranch = (
                WhileLoopAttribute.WhileLoopAttributeAddCondBranch
            )
            WhileLoopAttribute.AddBodyBranch = (
                WhileLoopAttribute.WhileLoopAttributeAddBodyBranch
            )
            WhileLoopAttribute.End = WhileLoopAttribute.WhileLoopAttributeEnd