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enginex-ascend-910-vllm/vllm_ascend/quantization/methods/w4a16_mxfp4.py
Sun Ruoxi 7f8a1b1f7a init v0.23.0
Signed-off-by: Sun Ruoxi <sunruoxi@4paradigm.com>
2026-08-27 15:11:51 +08:00

216 lines
8.6 KiB
Python

#
# Copyright (c) 2025 Huawei Technologies Co., Ltd. All Rights Reserved.
# This file is a part of the vllm-ascend project.
#
# 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.
#
"""Ascend W4A16_MXFP4 quantization helpers and fused MoE method."""
from collections.abc import Callable
from typing import Any
import torch
import torch_npu
from vllm.config import CompilationMode, get_current_vllm_config
from vllm.distributed import get_ep_group
from vllm_ascend.ascend_config import get_ascend_config
from vllm_ascend.ascend_forward_context import _EXTRA_CTX
from vllm_ascend.device.mxfp_compat import (
FLOAT8_E8M0FNU_DTYPE,
ensure_mxfp4_moe_available,
)
from vllm_ascend.ops.fused_moe.experts_selector import select_experts
from vllm_ascend.ops.fused_moe.moe_runtime_args import build_fused_experts_input
from .base import AscendMoEScheme, QuantType, get_moe_num_logical_experts
from .registry import register_scheme
# Unpack the weights to FP4 and return them in float32 format
def unpack_uint8_to_fp4_return_float32(packed: torch.Tensor) -> torch.Tensor:
low = packed & 0x0F
high = packed // 16
# The high 4 bits and low 4 bits are arranged alternately, with the low 4 bits in front.
unpacked = torch.stack([low, high], dim=-1).reshape(*packed.shape[:-1], -1)
# A 4-digit integer is mapped to mxfp4 based on its value.
fp4_values = torch.tensor(
[0.0, 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, 6.0, -0.0, -0.5, -1.0, -1.5, -2.0, -3.0, -4.0, -6.0],
dtype=torch.float32,
device=packed.device,
)
return fp4_values[unpacked.to(torch.long)]
@register_scheme("W4A16_MXFP4", "moe")
class AscendW4A16MXFP4FusedMoEMethod(AscendMoEScheme):
"""FusedMoE method for Ascend W4A16_MXFP4."""
quant_type: QuantType = QuantType.W4A16MXFP4
def __init__(self) -> None:
ensure_mxfp4_moe_available("W4A16_MXFP4 MoE quantization")
self.ep_group = get_ep_group()
vllm_config = get_current_vllm_config()
self.group_size = vllm_config.quant_config.quant_description.get("group_size", 32)
ascend_config = get_ascend_config()
self.use_aclgraph = (
vllm_config.compilation_config.mode == CompilationMode.VLLM_COMPILE
and not vllm_config.model_config.enforce_eager
)
self.dynamic_eplb = ascend_config.eplb_config.dynamic_eplb
def get_weight(
self,
num_experts: int,
intermediate_size_per_partition: int,
hidden_sizes: int,
params_dtype: torch.dtype,
) -> dict[str, Any]:
param_dict = {}
param_dict["w13_weight"] = torch.empty(
num_experts,
2 * intermediate_size_per_partition,
hidden_sizes // 2,
dtype=torch.uint8,
)
param_dict["w2_weight"] = torch.empty(
num_experts,
hidden_sizes,
intermediate_size_per_partition // 2,
dtype=torch.uint8,
)
return param_dict
def get_dynamic_quant_param(
self,
num_experts: int,
intermediate_size_per_partition: int,
hidden_sizes: int,
params_dtype: torch.dtype,
) -> dict[str, Any]:
param_dict = {}
param_dict["w13_weight_scale"] = torch.empty(
num_experts, 2 * intermediate_size_per_partition, hidden_sizes // self.group_size, dtype=torch.uint8
)
param_dict["w2_weight_scale"] = torch.empty(
num_experts, hidden_sizes, intermediate_size_per_partition // self.group_size, dtype=torch.uint8
)
return param_dict
def apply(
self,
layer: torch.nn.Module,
x: torch.Tensor,
router_logits: torch.Tensor,
top_k: int,
renormalize: bool,
use_grouped_topk: bool = False,
num_experts: int = -1,
expert_map: torch.Tensor | None = None,
topk_group: int | None = None,
num_expert_group: int | None = None,
custom_routing_function: Callable | None = None,
scoring_func: str = "softmax",
routed_scaling_factor: float = 1.0,
e_score_correction_bias: torch.Tensor | None = None,
is_prefill: bool = True,
enable_force_load_balance: bool = True,
log2phy: torch.Tensor | None = None,
global_redundant_expert_num: int = 0,
pertoken_scale: Any | None = None,
activation: str = "silu",
apply_router_weight_on_input: bool = False,
mc2_mask: torch.Tensor | None = None,
tid2eid: torch.Tensor | None = None,
) -> torch.Tensor:
num_shared_experts = getattr(layer, "n_shared_experts", 0)
if num_shared_experts is None:
num_shared_experts = 0
num_logical_experts = get_moe_num_logical_experts(
layer,
num_experts,
global_redundant_expert_num=global_redundant_expert_num,
num_shared_experts=num_shared_experts,
)
assert router_logits.shape[1] == num_logical_experts, (
"Number of global experts mismatch (excluding redundancy): "
f"router_logits.shape[1]={router_logits.shape[1]}, num_logical_experts={num_logical_experts}"
)
topk_weights, topk_ids = select_experts(
hidden_states=x,
router_logits=router_logits,
top_k=top_k,
use_grouped_topk=use_grouped_topk,
renormalize=renormalize,
topk_group=topk_group,
num_expert_group=num_expert_group,
custom_routing_function=custom_routing_function,
scoring_func=scoring_func,
e_score_correction_bias=e_score_correction_bias,
routed_scaling_factor=routed_scaling_factor,
num_experts=num_logical_experts,
tid2eid=tid2eid,
)
if enable_force_load_balance:
random_matrix = torch.rand(topk_ids.size(0), num_logical_experts, device=topk_ids.device)
topk_ids = torch.argsort(random_matrix, dim=1)[:, : topk_ids.size(1)].to(topk_ids.dtype)
topk_weights = topk_weights.to(x.dtype)
moe_comm_method = _EXTRA_CTX.moe_comm_method
return moe_comm_method.fused_experts(
fused_experts_input=build_fused_experts_input(
hidden_states=x,
topk_weights=topk_weights,
topk_ids=topk_ids,
w1=layer.w13_weight,
w2=layer.w2_weight,
quant_type=self.quant_type,
dynamic_eplb=self.dynamic_eplb,
expert_map=expert_map,
global_redundant_expert_num=global_redundant_expert_num,
mc2_mask=mc2_mask,
apply_router_weight_on_input=apply_router_weight_on_input,
log2phy=log2phy,
pertoken_scale=pertoken_scale,
activation=activation,
mxfp_act_quant_type=None,
mxfp_weight_quant_type=torch_npu.float4_e2m1fn_x2,
mxfp_scale_dtype=FLOAT8_E8M0FNU_DTYPE,
mxfp_per_token_scale_dtype=None,
mxfp_use_bf16=(x.dtype == torch.bfloat16),
w1_scale=layer.w13_weight_scale,
w2_scale=layer.w2_weight_scale,
swiglu_limit=layer.swiglu_limit,
)
)
def process_weights_after_loading(self, layer):
layer.w13_weight.data = unpack_uint8_to_fp4_return_float32(layer.w13_weight.data)
layer.w13_weight.data = layer.w13_weight.data.transpose(1, 2)
layer.w13_weight.data = torch_npu.npu_format_cast(layer.w13_weight.data, 29, customize_dtype=torch.bfloat16)
layer.w13_weight.data = torch_npu.npu_convert_weight_to_int4pack(layer.w13_weight.data).contiguous()
layer.w2_weight.data = unpack_uint8_to_fp4_return_float32(layer.w2_weight.data)
layer.w2_weight.data = layer.w2_weight.data.transpose(1, 2)
layer.w2_weight.data = torch_npu.npu_format_cast(layer.w2_weight.data, 29, customize_dtype=torch.bfloat16)
layer.w2_weight.data = torch_npu.npu_convert_weight_to_int4pack(layer.w2_weight.data).contiguous()
layer.w13_weight_scale.data = layer.w13_weight_scale.data.transpose(1, 2).contiguous()
layer.w2_weight_scale.data = layer.w2_weight_scale.data.transpose(1, 2).contiguous()