xc-llm-ascend/vllm_ascend/quantization/utils.py

from typing import Any, Dict, Optional, Type

import torch
from vllm.logger import logger

from vllm_ascend.utils import COMPRESSED_TENSORS_METHOD

from .w4a4_flatquant_dynamic import AscendW4A4FlatQuantDynamicLinearMethod
from .w4a8_dynamic import (AscendW4A8DynamicFusedMoEMethod,
                           AscendW4A8DynamicLinearMethod)
from .w4a16 import AscendW4A16FusedMoEMethod
from .w8a8 import AscendW8A8LinearMethod
from .w8a8_dynamic import (AscendW8A8DynamicFusedMoEMethod,
                           AscendW8A8DynamicLinearMethod)
from .w8a8_pdmix import (AscendW8A8PDMixFusedMoeMethod,
                         AscendW8A8PDMixLinearMethod)
from .w8a8mxfp8 import AscendW8A8MXFP8DynamicLinearMethod
from .w8a16 import AscendW8A16LinearMethod

ASCEND_QUANTIZATION_METHOD_MAP: Dict[str, Dict[str, Type[Any]]] = {
    "W4A16": {
        "moe": AscendW4A16FusedMoEMethod,
    },
    "W4A8_DYNAMIC": {
        "linear": AscendW4A8DynamicLinearMethod,
        "moe": AscendW4A8DynamicFusedMoEMethod,
    },
    "W4A4_FLATQUANT_DYNAMIC": {
        "linear": AscendW4A4FlatQuantDynamicLinearMethod,
    },
    "W8A8": {
        "linear": AscendW8A8LinearMethod,
    },
    "W8A8_DYNAMIC": {
        "linear": AscendW8A8DynamicLinearMethod,
        "moe": AscendW8A8DynamicFusedMoEMethod,
    },
    "W8A8_MIX": {
        "linear": AscendW8A8PDMixLinearMethod,
        "moe": AscendW8A8PDMixFusedMoeMethod,
    },
    "W8A16": {
        "linear": AscendW8A16LinearMethod,
    },
    "W8A8_MXFP8": {
        "linear": AscendW8A8MXFP8DynamicLinearMethod,
    },
}


def get_linear_quant_type(quant_description: Dict[str, Any], prefix: str,
                          packed_modules_mapping: Dict[str, Any]):
    proj_name = prefix.split(".")[-1]
    if proj_name in packed_modules_mapping:
        quant_type = None
        shard_prefixes = [
            prefix.replace(proj_name, shard_proj_name)
            for shard_proj_name in packed_modules_mapping[proj_name]
        ]
        for shard_prefix in shard_prefixes:
            shard_quant_type = quant_description[shard_prefix + '.weight']

            if quant_type is None:
                quant_type = shard_quant_type
            elif shard_quant_type != quant_type:
                raise ValueError(
                    f"Not all shards of {prefix} are quantized with same quant type."
                    f"Shard {proj_name} uses {shard_quant_type}, but another shard"
                    f"use {quant_type}. Please check quantization config.")
    else:
        quant_type = quant_description[prefix + '.weight']
    return quant_type


def get_quant_method(quant_description: Dict[str, Any],
                     prefix: str,
                     layer_type: str,
                     packed_modules_mapping: Optional[Dict[str, Any]] = None,
                     layer: torch.nn.Module = None):
    if quant_description.get("quant_method") == COMPRESSED_TENSORS_METHOD:
        return get_quant_method_llmcompressor(layer)

    return get_quant_method_modelslim(quant_description, prefix, layer_type,
                                      packed_modules_mapping)


def get_quant_method_llmcompressor(layer: torch.nn.Module):
    logger.info_once("Using the vLLM Ascend llmcompressor Quantization now!")
    if layer.scheme is None:
        raise ValueError("A scheme must be defined for each layer")
    return layer.scheme


def get_quant_method_modelslim(
        quant_description: Dict[str, Any],
        prefix: str,
        layer_type: str,
        packed_modules_mapping: Optional[Dict[str, Any]] = None):
    logger.info_once("Using the vLLM Ascend modelslim Quantization now!")
    if packed_modules_mapping is None:
        packed_modules_mapping = dict()
    # Attention
    if '.attn' in prefix and 'fa_quant_type' in quant_description.keys():
        quant_type = quant_description['fa_quant_type']
    # Linear
    else:
        quant_type = get_linear_quant_type(quant_description, prefix,
                                           packed_modules_mapping)
    if quant_type in ASCEND_QUANTIZATION_METHOD_MAP.keys():
        method_map = ASCEND_QUANTIZATION_METHOD_MAP[quant_type]
        if layer_type in method_map.keys():
            method_cls = method_map[layer_type]
            return method_cls()
        else:
            raise NotImplementedError(
                f"Currently, vLLM Ascend doesn't support {quant_type} for {layer_type}."
            )
    raise NotImplementedError("Currently, vLLM Ascend only supports following quant types:" \
                                f"{list(ASCEND_QUANTIZATION_METHOD_MAP.keys())}")


def is_mx_quant_type(instance: Any) -> bool:
    """Checks if the quantization method is a mix-precision type."""
    MX_QUANT_TYPES = (AscendW8A8MXFP8DynamicLinearMethod, )
    return isinstance(instance, MX_QUANT_TYPES)