Model-Optimizer/modelopt/torch/quantization/mode.py

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"""This module contains the mode descriptor for the quantization mode."""

from abc import abstractmethod
from collections.abc import Callable

from modelopt.torch.opt.config import ModeloptBaseConfig
from modelopt.torch.opt.conversion import ModelLikeModule
from modelopt.torch.opt.mode import (
    ConvertEntrypoint,
    ConvertReturnType,
    ModeConfigList,
    ModeDescriptor,
    RestoreEntrypoint,
    UpdateEntrypoint,
    _ModeRegistryCls,
)
from modelopt.torch.opt.searcher import ForwardLoop

from .compress import compress_convert, compress_restore, update_compress_metadata
from .config import (
    AWQClipCalibConfig,
    AWQFullCalibConfig,
    AWQLiteCalibConfig,
    CompressConfig,
    MaxCalibConfig,
    QuantizeAlgoCfgType,
    QuantizeAlgorithmConfig,
    QuantizeConfig,
    SmoothQuantCalibConfig,
    SVDQuantConfig,
    _QuantizeExportConfig,
)
from .conversion import (
    convert_to_quantized_model,
    export_quantized_model,
    restore_export_quantized_model,
    restore_quantized_model,
    restore_quantizer_state,
    restore_svdquant_model,
    update_quantize_metadata,
)
from .model_calib import awq, max_calibrate, smoothquant, svdquant

__all__ = ["BaseCalibrateModeDescriptor"]

QuantizeModeRegistry = _ModeRegistryCls("quantization")


# TODO: OMNIML-717 Reuse search infra for quantization calibration algorithms
@QuantizeModeRegistry.register_mode
class QuantizeModeDescriptor(ModeDescriptor):
    """Class to describe the ``"quant"`` mode.

    The properties of this mode can be inspected via the source code.
    """

    @property
    def name(self) -> str:
        """Returns the value (str representation) of the mode."""
        return "quantize"

    @property
    def config_class(self) -> type[ModeloptBaseConfig]:
        """Specifies the config class for the mode."""
        return QuantizeConfig

    @property
    def next_prohibited_modes(self) -> set[str] | None:
        """Modes that should not be applied after this mode."""
        return {"sparsity", "autonas", "fastnas", "gradnas"}

    @property
    def export_mode(self) -> str | None:
        """The mode that corresponds to the export mode of this mode."""
        return "export_quantize"

    @property
    def convert(self) -> ConvertEntrypoint:
        """The mode's entrypoint for converting a model."""
        return convert_to_quantized_model

    @property
    def restore(self) -> RestoreEntrypoint:
        """The mode's entrypoint for restoring a model."""
        return restore_quantized_model

    @property
    def update_for_save(self) -> UpdateEntrypoint:
        """The mode's entrypoint for updating the models state before saving."""
        return update_quantize_metadata

    @property
    def update_for_new_mode(self) -> UpdateEntrypoint:
        """The mode's entrypoint for updating the models state before new mode."""
        return update_quantize_metadata


@QuantizeModeRegistry.register_mode
class QuantizeExportModeDescriptor(ModeDescriptor):
    """Class to describe the export of quantization mode.

    Note that this mode is just a placeholder to throw an error since we don't support exporting
    quantized models right now. It is used to properly indicate that the ``quantize`` mode does
    require an export mode if we ever wanted to do chaining/stacking of modes with it.
    """

    @property
    def name(self) -> str:
        """Returns the value (str representation) of the mode."""
        return "quantize_export"

    @property
    def config_class(self) -> type[ModeloptBaseConfig]:
        """Specifies the config class for the mode."""
        return _QuantizeExportConfig

    @property
    def is_export_mode(self) -> bool:
        """Specifies whether the mode is an export mode."""
        return True

    @property
    def convert(self) -> ConvertEntrypoint:
        """The mode's entrypoint for converting a model."""
        return export_quantized_model

    @property
    def restore(self) -> RestoreEntrypoint:
        """The mode's entrypoint for restoring a model."""
        return restore_export_quantized_model


@QuantizeModeRegistry.register_mode
class RealQuantizeModeDescriptor(ModeDescriptor):
    """Mode for real quantization."""

    @property
    def name(self) -> str:
        """Returns the value (str representation) of the mode."""
        return "real_quantize"

    @property
    def next_modes(self) -> set[str] | None:
        """Real quantization should be the last mode in the chain."""
        # TODO: update this to support QLoRA
        return {"max_calibrate", "eagle"}

    @property
    def config_class(self) -> type[ModeloptBaseConfig]:
        """Specifies the config class for the mode."""
        return CompressConfig

    @property
    def convert(self) -> ConvertEntrypoint:
        """The mode's entrypoint for converting a model."""
        return compress_convert

    @property
    def restore(self) -> RestoreEntrypoint:
        """The mode's entrypoint for restoring a model."""
        return compress_restore

    @property
    def update_for_save(self) -> UpdateEntrypoint:
        """The mode's entrypoint for updating the models state before saving."""
        return update_compress_metadata

    @property
    def update_for_new_mode(self) -> UpdateEntrypoint:
        """The mode's entrypoint for updating the models state before new mode."""
        return update_compress_metadata


@QuantizeModeRegistry.register_mode
class AutoQuantizeModeDescriptor(QuantizeModeDescriptor):
    """Mode for autoquantize."""

    @property
    def name(self) -> str:
        """Returns the value (str representation) of the mode."""
        return "auto_quantize"


def wrapped_calib_func(
    model: ModelLikeModule,
    config: QuantizeAlgorithmConfig,
    forward_loop: ForwardLoop | None = None,
    func: Callable | None = None,
) -> ConvertReturnType:
    """Wrap the calibration function to be compatible with the ModelOpt convert entrypoint.

    The calibration algorithms in ..model_calib.py are designed to be called directly with the model,
    forward_loop and the relevant kwargs and are independent of the ModelOpt framework.
    So lets wrap them to be compatible with the ModelOpt convert entrypoint.
    """
    kwargs = config.model_dump()
    method = kwargs.pop("method")
    if method is not None and "awq" in method:
        # For backward compatibility
        kwargs["algorithm"] = method

    if func is not None:
        # Call the function with forward_loop as a separate argument
        func(model, forward_loop=forward_loop, **kwargs)

    # Lets get the latest metadata for the quantizer states
    metadata = {}
    update_quantize_metadata(model, config, metadata)
    return model, metadata


class BaseCalibrateModeDescriptor(ModeDescriptor):
    """Base class for quantization calibration algorithm modes.

    All calibration algorithm modes must be derived from this base class.
    In addition, the `config_class` for the mode must return a subclass of :class:`QuantizeAlgorithmConfig`.

    This base class also provides some convenient wrappers/utilities for calibration algorithms to be
    translated into ModelOpt mode.

    It includes:
        1. A utility to convert the algorithm name to a mode name. This is useful since many algorithm names
            are trivial and not a good fit as a mode name. For example, ``"max"`` or ``None``.
        2. Conversion of the ``algorithm`` and ``kwargs`` arguments of
            :meth:`calibrate <modelopt.torch.quantization.model_quant.calibrate>` API to a mode config
            list compatible with :meth:`apply_mode <modelopt.torch.opt.conversion.apply_mode>`.
        3. Wrapper for the calibration functions in :mod:`modelopt.torch.quantization.model_calib` to be
            compatible with the ModelOpt convert entrypoint.
    """

    _calib_func: Callable | None

    def __init__(self, *args, **kwargs):
        """Initialize Base calibrate mode descriptor."""
        assert issubclass(self.config_class, QuantizeAlgorithmConfig), (
            f"`config_class` of {self.__class__} must be a subclass of `QuantizeAlgorithmConfig`!, "
            f"got {self.config_class}!"
        )
        super().__init__(*args, **kwargs)

    @classmethod
    def _get_mode_name(cls, algo_name: str | None = None, check: bool = False) -> str:
        mode_name = algo_name + "_calibrate" if algo_name else "_no_calibrate"
        if check:
            assert mode_name in CalibrateModeRegistry, (
                f"Algorithm {algo_name} not found in CalibrateModeRegistry!"
            )
        return mode_name

    @property
    def name(self) -> str:
        """Returns the value (str representation) of the mode."""
        return self._get_mode_name(self.config_class().method)

    @property
    @abstractmethod
    def config_class(self) -> type[QuantizeAlgorithmConfig]:
        """Specifies the config class for the mode."""

    @property
    def convert(self) -> ConvertEntrypoint:
        """The calibrate algorithm mode's entrypoint for converting a model.

        This method is called by the ModelOpt framework when applying this calibration mode to a model.
        See :meth:`wrapped_calib_func` for more details on the logic.

        Note: Subclasses must specify the `_calib_func` class attribute with the appropriate
        calibration function to be used or override this method.
        """
        assert hasattr(self.__class__, "_calib_func"), (
            f"Calibration function '_calib_func' not defined for {self.__class__}, "
            "either define it or override the `convert` method!"
        )

        def wrapped_func(model, config, forward_loop=None):
            # Access _calib_func as a class attribute to avoid binding
            # Check if _calib_func is defined as a class attribute
            return wrapped_calib_func(model, config, forward_loop, func=self.__class__._calib_func)

        return wrapped_func

    @property
    def restore(self) -> RestoreEntrypoint:
        """The mode's entrypoint for restoring a model."""
        return restore_quantizer_state

    @property
    def update_for_save(self) -> UpdateEntrypoint:
        """The mode's entrypoint for updating the models state before saving."""
        return update_quantize_metadata

    @property
    def update_for_new_mode(self) -> UpdateEntrypoint:
        """The mode's entrypoint for updating the models state before new mode."""
        return update_quantize_metadata


def get_modelike_from_algo_cfg(algo_cfg: QuantizeAlgoCfgType) -> ModeConfigList:
    """Get the mode like from the algorithm config."""
    if isinstance(algo_cfg, list):
        assert not any(isinstance(c, list) for c in algo_cfg), (
            f"Nested lists received as config! config: {algo_cfg}"
        )
        return [get_modelike_from_algo_cfg(c)[0] for c in algo_cfg]
    if algo_cfg is None or isinstance(algo_cfg, str):
        algo_name, algo_cfg = algo_cfg, {}
    elif isinstance(algo_cfg, dict):
        algo_name = algo_cfg["method"]
    else:
        raise ValueError(f"Invalid config type: {type(algo_cfg)}")
    return [(BaseCalibrateModeDescriptor._get_mode_name(algo_name, check=True), algo_cfg)]


class _CalibrateModeRegistryCls(_ModeRegistryCls):
    def register_mode(self, cls_descriptor: type[_ModeRegistryCls.T]) -> type[_ModeRegistryCls.T]:
        """Register a new mode with the given descriptor."""
        assert issubclass(cls_descriptor, BaseCalibrateModeDescriptor), (
            f"Mode descriptor for `_CalibrateModeRegistryCls` must be a subclass of `BaseCalibrateModeDescriptor`! "
            f"Got: {cls_descriptor}"
        )
        return super().register_mode(cls_descriptor)  # type: ignore [arg-type]


CalibrateModeRegistry = _CalibrateModeRegistryCls("calibrate_algos")


@CalibrateModeRegistry.register_mode
class NoneCalibrateModeDescriptor(BaseCalibrateModeDescriptor):
    """Mode for no calibration algorithm."""

    @property
    def config_class(self) -> type[QuantizeAlgorithmConfig]:
        """Specifies the config class for the mode."""
        return QuantizeAlgorithmConfig

    _calib_func = None


@CalibrateModeRegistry.register_mode
class MaxCalibrateModeDescriptor(BaseCalibrateModeDescriptor):
    """Mode for max calibration algorithm."""

    @property
    def config_class(self) -> type[QuantizeAlgorithmConfig]:
        """Specifies the config class for the mode."""
        return MaxCalibConfig

    _calib_func = max_calibrate


@CalibrateModeRegistry.register_mode
class SmoothQuantModeDescriptor(BaseCalibrateModeDescriptor):
    """Mode for smoothquant calibration algorithm."""

    @property
    def config_class(self) -> type[QuantizeAlgorithmConfig]:
        """Specifies the config class for the mode."""
        return SmoothQuantCalibConfig

    _calib_func = smoothquant


@CalibrateModeRegistry.register_mode
class AWQLiteModeDescriptor(BaseCalibrateModeDescriptor):
    """Mode for AWQ lite calibration algorithm."""

    @property
    def config_class(self) -> type[QuantizeAlgorithmConfig]:
        """Specifies the config class for the mode."""
        return AWQLiteCalibConfig

    _calib_func = awq


@CalibrateModeRegistry.register_mode
class AWQClipModeDescriptor(BaseCalibrateModeDescriptor):
    """Mode for AWQ clip calibration algorithm."""

    @property
    def config_class(self) -> type[QuantizeAlgorithmConfig]:
        """Specifies the config class for the mode."""
        return AWQClipCalibConfig

    _calib_func = awq


@CalibrateModeRegistry.register_mode
class AWQFullModeDescriptor(BaseCalibrateModeDescriptor):
    """Mode for AWQ full calibration algorithm."""

    @property
    def config_class(self) -> type[QuantizeAlgorithmConfig]:
        """Specifies the config class for the mode."""
        return AWQFullCalibConfig

    _calib_func = awq


@CalibrateModeRegistry.register_mode
class SVDQuantModeDescriptor(BaseCalibrateModeDescriptor):
    """Mode for SVDQuant calibration algorithm."""

    @property
    def config_class(self) -> type[QuantizeAlgorithmConfig]:
        """Specifies the config class for the mode."""
        return SVDQuantConfig

    _calib_func = svdquant

    @property
    def restore(self) -> RestoreEntrypoint:
        """The mode's entrypoint for restoring a model."""
        return restore_svdquant_model