chore: import upstream snapshot with attribution

vllm/model_executor/layers/quantization/experts_int8.py

@@ -0,0 +1,60 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+
+from typing import Any
+
+import torch
+
+from vllm.model_executor.layers.fused_moe import (
+    RoutedExperts,
+)
+from vllm.model_executor.layers.linear import LinearBase, UnquantizedLinearMethod
+from vllm.model_executor.layers.quantization import QuantizationMethods
+from vllm.model_executor.layers.quantization.base_config import (
+    QuantizationConfig,
+    QuantizeMethodBase,
+)
+from vllm.model_executor.layers.quantization.online.int8 import (
+    Int8OnlineMoEMethod,
+)
+
+
+class ExpertsInt8Config(QuantizationConfig):
+    """Online int8 quantization for MoE expert weights.
+    Linear layers are left unquantized.
+
+    Backward-compatible config for ``--quantization experts_int8``.
+    Prefer ``--quantization int8_per_channel``
+    """
+
+    def __init__(self) -> None:
+        super().__init__()
+
+    @classmethod
+    def get_name(cls) -> QuantizationMethods:
+        return "experts_int8"
+
+    @classmethod
+    def get_supported_act_dtypes(cls) -> list[torch.dtype]:
+        return [torch.bfloat16, torch.half]
+
+    @classmethod
+    def get_min_capability(cls) -> int:
+        return 80
+
+    @classmethod
+    def get_config_filenames(cls) -> list[str]:
+        return []
+
+    @classmethod
+    def from_config(cls, config: dict[str, Any]) -> "ExpertsInt8Config":
+        return cls()
+
+    def get_quant_method(
+        self, layer: torch.nn.Module, prefix: str
+    ) -> "QuantizeMethodBase | None":
+        if isinstance(layer, LinearBase):
+            return UnquantizedLinearMethod()
+        elif isinstance(layer, RoutedExperts):
+            return Int8OnlineMoEMethod(layer=layer)
+        return None