Merge branch 'main' into higgs

src/diffusers/models/model_loading_utils.py

@@ -30,6 +30,7 @@ from huggingface_hub import DDUFEntry
 from huggingface_hub.utils import EntryNotFoundError
 
 from ..quantizers import DiffusersQuantizer
+from ..quantizers.quantization_config import QuantizationMethod
 from ..utils import (
     GGUF_FILE_EXTENSION,
     SAFE_WEIGHTS_INDEX_NAME,
@@ -231,6 +232,7 @@ def load_model_dict_into_meta(
     """
 
     is_quantized = hf_quantizer is not None
+    is_higgs = is_quantized and hf_quantizer.quantization_config.quant_method == QuantizationMethod.HIGGS
     empty_state_dict = model.state_dict()
 
     for param_name, param in state_dict.items():
@@ -280,7 +282,8 @@ def load_model_dict_into_meta(
 
         # bnb params are flattened.
         # gguf quants have a different shape based on the type of quantization applied
-        if empty_state_dict[param_name].shape != param.shape:
+        # higgs quants repack the weights so they will have different shapes
+        if empty_state_dict[param_name].shape != param.shape and not is_higgs:
             if (
                 is_quantized
                 and hf_quantizer.pre_quantized
@@ -304,7 +307,7 @@ def load_model_dict_into_meta(
             hf_quantizer.create_quantized_param(
                 model, param, param_name, param_device, state_dict, unexpected_keys, dtype=dtype
             )
-        else:
+        elif hf_quantizer is not None:
             set_module_tensor_to_device(model, param_name, param_device, value=param, **set_module_kwargs)
 
     return offload_index, state_dict_index

src/diffusers/quantizers/auto.py

@@ -21,9 +21,11 @@ from typing import Dict, Optional, Union
 
 from .bitsandbytes import BnB4BitDiffusersQuantizer, BnB8BitDiffusersQuantizer
 from .gguf import GGUFQuantizer
+from .higgs import HiggsQuantizer
 from .quantization_config import (
     BitsAndBytesConfig,
     GGUFQuantizationConfig,
+    HiggsConfig,
     QuantizationConfigMixin,
     QuantizationMethod,
     QuantoConfig,
@@ -39,6 +41,7 @@ AUTO_QUANTIZER_MAPPING = {
     "gguf": GGUFQuantizer,
     "quanto": QuantoQuantizer,
     "torchao": TorchAoHfQuantizer,
+    "higgs": HiggsQuantizer,
 }
 
 AUTO_QUANTIZATION_CONFIG_MAPPING = {
@@ -47,6 +50,7 @@ AUTO_QUANTIZATION_CONFIG_MAPPING = {
     "gguf": GGUFQuantizationConfig,
     "quanto": QuantoConfig,
     "torchao": TorchAoConfig,
+    "higgs": HiggsConfig,
 }
 
 

src/diffusers/quantizers/higgs/__init__.py

@@ -0,0 +1 @@
+from .higgs_quantizer import HiggsQuantizer

src/diffusers/quantizers/higgs/higgs_quantizer.py

@@ -0,0 +1,205 @@
+# Copyright 2025 The HuggingFace Inc. team. All rights reserved.
+#
+# 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.
+"""
+Adapted from
+https://github.com/huggingface/transformers/blob/d3d835d4fc145e5062d2153ac23ccd4b3e2c2cbd/src/transformers/quantizers/quantizer_higgs.py
+"""
+
+from typing import TYPE_CHECKING, Any, Optional
+
+from ...utils import get_module_from_name
+from ..base import DiffusersQuantizer
+
+
+if TYPE_CHECKING:
+    from ...models.modeling_utils import ModelMixin
+
+from ...utils import is_accelerate_available, is_torch_available, logging
+from ...utils.logging import tqdm
+
+
+if is_torch_available():
+    import torch
+
+logger = logging.get_logger(__name__)
+
+
+class HiggsQuantizer(DiffusersQuantizer):
+    """
+    Quantizer of the HIGGS method. Enables the loading of prequantized models and in-flight quantization of
+    full-precision models.
+    """
+
+    requires_calibration = False
+    requires_parameters_quantization = True
+    required_packages = ["flute-kernel", "fast_hadamard_transform"]
+
+    def __init__(self, quantization_config, **kwargs):
+        super().__init__(quantization_config, **kwargs)
+        self.quantization_config = quantization_config
+
+    def validate_environment(self, device_map, **kwargs):
+        if not torch.cuda.is_available():
+            raise NotImplementedError("HIGGS quantization is only supported on GPU. Please use a different quantizer.")
+
+        if not is_accelerate_available():
+            raise ImportError("Using `higgs` quantization requires Accelerate: `pip install accelerate`")
+
+        # TODO: enable this.
+        # if not is_flute_available():
+        #     raise ImportError("Using `higgs` quantization requires FLUTE: `pip install flute-kernel>=0.3.0`")
+
+        # if not is_hadamard_available():
+        #     raise ImportError(
+        #         "Using `higgs` quantization requires fast_hadamard_transform: `pip install fast_hadamard_transform`"
+        #     )
+
+        if device_map is None:
+            raise ValueError(
+                "You are attempting to load a HIGGS model without setting device_map."
+                " Please set device_map comprised of 'cuda' devices."
+            )
+        elif isinstance(device_map, dict) and ("cpu" in device_map.values() or "disk" in device_map.values()):
+            raise ValueError(
+                "You are attempting to load a HIGGS model with a device_map that contains a CPU or disk device."
+                " This is not supported. Please remove the CPU or disk device from the device_map."
+            )
+
+    def update_torch_dtype(self, torch_dtype: "torch.dtype") -> "torch.dtype":
+        if torch_dtype is None:
+            logger.info("`torch_dtype` is None. Setting `torch_dtype=torch.float16` for FLUTE compatibility.")
+            torch_dtype = torch.float16
+        elif torch_dtype != torch.float16 and torch_dtype != torch.bfloat16:
+            raise ValueError(
+                f"Invalid `torch_dtype` {torch_dtype}. HIGGS quantization only supports `torch_dtype=torch.float16` or `torch_dtype=torch.bfloat16`."
+            )
+
+        return torch_dtype
+
+    def create_quantized_param(
+        self,
+        model: "ModelMixin",
+        param_value: "torch.Tensor",
+        param_name: str,
+        target_device: "torch.device",
+        state_dict: dict[str, Any],
+        unexpected_keys: Optional[list[str]] = None,
+    ):
+        from .utils import quantize_with_higgs
+
+        """
+        Quantizes weights into weight and weight_scale
+        """
+        flute_dict = quantize_with_higgs(
+            param_value.to(target_device),
+            self.quantization_config.bits,
+            self.quantization_config.p,
+            self.quantization_config.group_size,
+            self.quantization_config.hadamard_size,
+        )
+        del param_value
+
+        module, _ = get_module_from_name(model, param_name)
+        module_name = ".".join(param_name.split(".")[:-1])
+        for key, value in flute_dict.items():
+            if key in module._parameters:
+                module._parameters[key] = torch.nn.Parameter(value, requires_grad=False)
+            elif key in module._buffers:
+                module._buffers[key] = torch.nn.Buffer(value)
+            elif key == "tune_metadata":
+                module.tune_metadata = value
+                self.quantization_config.tune_metadata[module_name] = value.to_dict()
+            else:
+                raise ValueError(f"Unexpected key {key} in module {module}")
+
+        if unexpected_keys is not None and param_name in unexpected_keys:
+            unexpected_keys.remove(param_name)
+
+    def update_missing_keys(self, model, missing_keys: list[str], prefix: str) -> list[str]:
+        from .utils import HiggsLinear
+
+        higgs_names = {name for name, module in model.named_modules() if isinstance(module, HiggsLinear)}
+
+        def should_update(key: str) -> bool:
+            if key.endswith(".weight") or key.endswith(".bias"):
+                return False
+            full_key = f"{prefix}.{key}"
+            return any(name in key or name in full_key for name in higgs_names)
+
+        return [key for key in missing_keys if not should_update(key)]
+
+    @property
+    def is_trainable(self):
+        return False
+
+    def is_serializable(self):
+        return True
+
+    def check_quantized_param(
+        self,
+        model: "ModelMixin",
+        param_value: "torch.Tensor",
+        param_name: str,
+        state_dict: dict[str, Any],
+        **kwargs,
+    ) -> bool:
+        from .utils import HiggsLinear
+
+        module, tensor_name = get_module_from_name(model, param_name)
+        if isinstance(module, HiggsLinear) and tensor_name == "weight" and param_value.dtype != torch.int16:
+            # Only quantize weights of HiggsLinear modules that are not already quantized
+            return True
+        else:
+            return False
+
+    def _process_model_before_weight_loading(
+        self,
+        model: "ModelMixin",
+        **kwargs,
+    ):
+        from .utils import replace_with_higgs_linear
+
+        replace_with_higgs_linear(model, quantization_config=self.quantization_config)
+        model.config.quantization_config = self.quantization_config
+
+    def _process_model_after_weight_loading(self, model: "ModelMixin", **kwargs):
+        from flute.tune import TuneMetaData, maybe_tune_and_repack
+        from flute.utils import make_workspace_streamk
+
+        from .utils import HiggsLinear
+
+        flute_workspaces = {}
+        flute_modules = {name: module for name, module in model.named_modules() if isinstance(module, HiggsLinear)}
+        for name, module in tqdm(flute_modules.items(), desc="Repacking HIGGS modules", leave=False):
+            # Every HiggsLinear needs a "workspace": a buffer for the unpacking operation.
+            # This buffer needs to be on the same device as the weights, but can be reused across modules otherwise.
+            if module.weight.device not in flute_workspaces:
+                flute_workspaces[module.weight.device] = make_workspace_streamk(device=module.weight.device)
+            module.workspace = flute_workspaces[module.weight.device]
+
+            # FLUTE weights are packed in a way that is optimized for a specific number of SMs (GPU streaming multiprocessors).
+            # If the model is loaded on a different device than the one it was saved on, we need to repack the weights.
+            module.tune_metadata = TuneMetaData.from_dict(self.quantization_config.tune_metadata[name])
+            module.weight.data, module.tune_metadata = maybe_tune_and_repack(
+                weight=module.weight.data,
+                scales=module.scales.data,
+                metadata=module.tune_metadata,
+            )
+            self.quantization_config.tune_metadata[name] = module.tune_metadata.to_dict()
+
+    def _dequantize(self, model):
+        from .utils import dequantize_higgs
+
+        model = dequantize_higgs(model)
+        return model

src/diffusers/quantizers/higgs/utils.py

@@ -0,0 +1,690 @@
+# Copyright 2025 The HuggingFace Team. All rights reserved.
+#
+# 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.
+"""
+HIGGS through FLUTE (Flexible Lookup Table Engine for LUT-quantized LLMs) integration file.
+
+Taken from:
+https://github.com/huggingface/transformers/blob/d3d835d4fc145e5062d2153ac23ccd4b3e2c2cbd/src/transformers/integrations/higgs.py
+"""
+
+from math import sqrt
+
+from ...utils import (
+    # TODO enable:
+    # is_flute_available,
+    # is_hadamard_available,
+    is_torch_available,
+    logging,
+)
+
+
+if is_torch_available():
+    import torch
+    from torch import nn
+
+
+# if is_flute_available():
+# if is_hadamard_available():
+from fast_hadamard_transform import hadamard_transform
+from flute.integrations.higgs import prepare_data_transposed
+from flute.tune import TuneMetaData, qgemm_v2
+
+
+logger = logging.get_logger(__name__)
+
+
+def pad_to_block(tensor, dims, had_block_size, value=0):
+    pad_dims = [0 for _ in range(2 * len(tensor.shape))]
+    for dim in dims:
+        size = tensor.shape[dim]
+        next_multiple_of_1024 = ((size - 1) // had_block_size + 1) * had_block_size
+        delta = next_multiple_of_1024 - size
+        pad_dims[-2 * dim - 1] = delta
+
+    return nn.functional.pad(tensor, pad_dims, "constant", value)
+
+
+def get_higgs_grid(p: int, n: int):
+    if (p, n) == (2, 256):
+        return torch.tensor(
+            [
+                [-2.501467704772949, 0.17954708635807037],
+                [-0.6761789321899414, 1.2728623151779175],
+                [-1.8025816679000854, 0.7613157629966736],
+                [-0.538287878036499, -2.6028504371643066],
+                [0.8415029644966125, -0.8600977659225464],
+                [0.7023013234138489, 3.3138747215270996],
+                [0.5699077844619751, 2.5782253742218018],
+                [3.292393207550049, -0.6016128063201904],
+                [0.5561617016792297, -1.7723814249038696],
+                [-2.1012380123138428, 0.020958125591278076],
+                [0.46085724234580994, 0.8428705334663391],
+                [1.4548040628433228, -0.6156039237976074],
+                [3.210029363632202, 0.3546904921531677],
+                [0.8893890976905823, -0.5967988967895508],
+                [0.8618854284286499, -3.2061192989349365],
+                [1.1360996961593628, -0.23852407932281494],
+                [1.6646337509155273, -0.9265465140342712],
+                [1.4767773151397705, 1.2476022243499756],
+                [-1.0511897802352905, 1.94503915309906],
+                [-1.56318998336792, -0.3264186680316925],
+                [-0.1829211413860321, 0.2922491431236267],
+                [-0.8950616717338562, -1.3887052536010742],
+                [-0.08206957578659058, -1.329533576965332],
+                [-0.487422913312912, 1.4817842245101929],
+                [-1.6769757270812988, -2.8269758224487305],
+                [-1.5057679414749146, 1.8905963897705078],
+                [1.8335362672805786, 1.0515104532241821],
+                [0.3273945450782776, 1.0491033792495728],
+                [-3.295924186706543, -0.7021600008010864],
+                [-1.8428784608840942, -1.2315762042999268],
+                [-0.8575026392936707, -1.7005949020385742],
+                [-1.120667815208435, 0.6467998027801514],
+                [-0.1588846743106842, -1.804071068763733],
+                [-0.8539647459983826, 0.5645008683204651],
+                [-1.4192019701004028, -0.6175029873847961],
+                [1.0799058675765991, 1.7871345281600952],
+                [1.171311855316162, 0.7511613965034485],
+                [2.162078380584717, 0.8044339418411255],
+                [1.3969420194625854, -1.243762493133545],
+                [-0.23818807303905487, 0.053944624960422516],
+                [2.304199457168579, -1.2667627334594727],
+                [1.4225027561187744, 0.568610668182373],
+                [0.376836895942688, -0.7134661674499512],
+                [2.0404467582702637, 0.4087389409542084],
+                [0.7639489769935608, -1.1367933750152588],
+                [0.3622530400753021, -1.4827953577041626],
+                [0.4100743532180786, 0.36108437180519104],
+                [-1.5867475271224976, -1.618212342262268],
+                [-2.2769672870635986, -1.2132309675216675],
+                [0.9184022545814514, -0.34428009390830994],
+                [-0.3902314603328705, 0.21785245835781097],
+                [3.120687484741211, 1.3077973127365112],
+                [1.587440848350525, -1.6506884098052979],
+                [-1.718808889389038, -0.038405973464250565],
+                [-0.6888407468795776, -0.8402308821678162],
+                [-0.7981445789337158, -1.1117373704910278],
+                [-2.4124443531036377, 1.3419722318649292],
+                [-0.6611530184745789, 0.9939885139465332],
+                [-0.33103418350219727, -0.16702833771705627],
+                [-2.4091389179229736, -2.326857566833496],
+                [1.6610108613967896, -2.159703254699707],
+                [0.014884627424180508, 0.3887578248977661],
+                [0.029668325558304787, 1.8786455392837524],
+                [1.180362582206726, 2.699317216873169],
+                [1.821286678314209, -0.5960053205490112],
+                [-0.44835323095321655, 3.327436685562134],
+                [-0.3714401423931122, -2.1466753482818604],
+                [-1.1103475093841553, -2.4536871910095215],
+                [-0.39110705256462097, 0.6670510172843933],
+                [0.474752813577652, -1.1959707736968994],
+                [-0.013110585510730743, -2.52519154548645],
+                [-2.0836575031280518, -1.703289270401001],
+                [-1.1077687740325928, -0.1252644956111908],
+                [-0.4138077199459076, 1.1837692260742188],
+                [-1.977599024772644, 1.688241720199585],
+                [-1.659559965133667, -2.1387736797332764],
+                [0.03242531046271324, 0.6526556015014648],
+                [0.9127950072288513, 0.6099498867988586],
+                [-0.38478314876556396, 0.433487206697464],
+                [0.27454206347465515, -0.27719801664352417],
+                [0.10388526320457458, 2.2812814712524414],
+                [-0.014394169673323631, -3.177137613296509],
+                [-1.2871228456497192, -0.8961855173110962],
+                [0.5720916986465454, -0.921597957611084],
+                [1.1159656047821045, -0.7609877586364746],
+                [2.4383342266082764, -2.2983546257019043],
+                [-0.294057160615921, -0.9770799875259399],
+                [-0.9342701435089111, 1.107579231262207],
+                [-1.549338698387146, 3.090520143508911],
+                [2.6076579093933105, 2.051239013671875],
+                [-0.9259037375450134, 1.407211184501648],
+                [-0.1747353971004486, 0.540488600730896],
+                [-0.8963701725006104, 0.8271111249923706],
+                [0.6480194926261902, 1.0128909349441528],
+                [0.980783998966217, -0.06156221032142639],
+                [-0.16883476078510284, 1.0601658821105957],
+                [0.5839992761611938, 0.004697148688137531],
+                [-0.34228450059890747, -1.2423977851867676],
+                [2.500824451446533, 0.3665279746055603],
+                [-0.17641609907150269, 1.3529551029205322],
+                [0.05378641560673714, 2.817232847213745],
+                [-1.2391047477722168, 2.354328155517578],
+                [0.630434513092041, -0.668536365032196],
+                [1.7576488256454468, 0.6738647818565369],
+                [0.4435231387615204, 0.6000469326972961],
+                [-0.08794835954904556, -0.11511358618736267],
+                [1.6540337800979614, 0.33995017409324646],
+                [-0.04202975332736969, -0.5375117063522339],
+                [-0.4247745871543884, -0.7897617220878601],
+                [0.06695003807544708, 1.2000739574432373],
+                [-3.2508881092071533, 0.28734830021858215],
+                [-1.613816261291504, 0.4944162368774414],
+                [1.3598989248275757, 0.26117825508117676],
+                [2.308382511138916, 1.3462618589401245],
+                [-1.2137469053268433, -1.9254342317581177],
+                [-0.4889402985572815, 1.8136259317398071],
+                [-0.1870335340499878, -0.3480615019798279],
+                [1.0766386985778809, -1.0627082586288452],
+                [0.4651014506816864, 2.131748914718628],
+                [-0.1306295394897461, -0.7811847925186157],
+                [0.06433182954788208, -1.5397958755493164],
+                [-0.2894323468208313, -0.5789554715156555],
+                [-0.6081662178039551, 0.4845278263092041],
+                [2.697964668273926, -0.18515698611736298],
+                [0.1277363896369934, -0.7221432328224182],
+                [0.8700758218765259, 0.35042452812194824],
+                [0.22088994085788727, 0.495242178440094],
+                [-2.5843818187713623, -0.8000828623771667],
+                [0.6732649803161621, -1.4362232685089111],
+                [-1.5286413431167603, 1.0417330265045166],
+                [-1.1222513914108276, -0.6269875764846802],
+                [-0.9752035140991211, -0.8750635385513306],
+                [-2.6369473934173584, 0.6918523907661438],
+                [0.14478731155395508, -0.041986867785453796],
+                [-1.5629483461380005, 1.4369450807571411],
+                [0.38952457904815674, -2.16428804397583],
+                [-0.16885095834732056, 0.7976621985435486],
+                [-3.12416934967041, 1.256506085395813],
+                [0.6843105554580688, -0.4203019142150879],
+                [1.9345275163650513, 1.934950351715088],
+                [0.012184220366179943, -2.1080918312072754],
+                [-0.6350273489952087, 0.7358828186988831],
+                [-0.837304949760437, -0.6214472651481628],
+                [0.08211923390626907, -0.9472538232803345],
+                [2.9332995414733887, -1.4956780672073364],
+                [1.3806978464126587, -0.2916182279586792],
+                [0.06773144006729126, 0.9285762310028076],
+                [-1.1943119764328003, 1.5963770151138306],
+                [1.6395620107650757, -0.32285431027412415],
+                [-1.390851378440857, -0.08273141086101532],
+                [1.816330909729004, -1.2812227010726929],
+                [0.7921574711799622, -2.1135804653167725],
+                [0.5817914605140686, 1.2644577026367188],
+                [1.929347038269043, -0.2386285960674286],
+                [0.8877345323562622, 1.190008521080017],
+                [1.4732073545455933, 0.8935023546218872],
+                [-2.8518524169921875, -1.5478795766830444],
+                [0.2439267635345459, 0.7576767802238464],
+                [0.5246709585189819, -2.606659412384033],
+                [1.150876760482788, 1.4073830842971802],
+                [-0.2643202245235443, 2.0634236335754395],
+                [1.555483341217041, -0.0023102816194295883],
+                [2.0830578804016113, -1.7225427627563477],
+                [-0.5424830317497253, -1.070199728012085],
+                [0.9168899655342102, 0.8955540060997009],
+                [-0.8120972514152527, 2.696739912033081],
+                [-0.29908373951911926, -1.5310651063919067],
+                [1.2320337295532227, -1.556247353553772],
+                [1.8612544536590576, 0.08704725652933121],
+                [0.22133447229862213, -1.8091708421707153],
+                [-0.4403655230998993, -0.38571012020111084],
+                [-1.88539457321167, 1.192205786705017],
+                [2.239687919616699, 0.004709010478109121],
+                [1.139495611190796, 0.45733731985092163],
+                [-1.507995367050171, 0.19716016948223114],
+                [0.46986445784568787, 1.5422041416168213],
+                [-1.2573751211166382, -0.35984551906585693],
+                [-1.7415345907211304, -0.6020717024803162],
+                [1.0751984119415283, 0.19006384909152985],
+                [2.24186635017395, -0.46343153715133667],
+                [0.3610347509384155, -0.07658443599939346],
+                [-1.3111497163772583, 0.432013601064682],
+                [0.6164408326148987, 0.24538464844226837],
+                [-1.9266542196273804, -0.3256155550479889],
+                [-0.5870336890220642, -0.1879584938287735],
+                [-1.0476511716842651, 0.3677721917629242],
+                [-1.229940414428711, 1.2433830499649048],
+                [0.18550436198711395, 0.22753673791885376],
+                [-0.017921989783644676, 0.12625974416732788],
+                [1.1659504175186157, -0.5020995736122131],
+                [-0.5983408093452454, -1.40438973903656],
+                [0.7519024014472961, -0.16282692551612854],
+                [0.9920787811279297, -1.344896912574768],
+                [-0.8103678226470947, 0.3064485788345337],
+                [0.6956969499588013, 1.8208192586898804],
+                [-2.7830491065979004, -0.2299390584230423],
+                [-0.34681546688079834, 2.4890666007995605],
+                [-1.4452646970748901, -1.2216600179672241],
+                [-2.1872897148132324, 0.8926076292991638],
+                [1.706072211265564, -2.8440372943878174],
+                [1.1119003295898438, -2.4923460483551025],
+                [-2.582794666290283, 2.0973289012908936],
+                [0.04987720400094986, -0.2964983284473419],
+                [-2.063807487487793, -0.7847916483879089],
+                [-0.4068813621997833, 0.9135897755622864],
+                [-0.9814359545707703, -0.3874954879283905],
+                [-1.4227229356765747, 0.7337291240692139],
+                [0.3065044581890106, 1.3125417232513428],
+                [1.2160996198654175, -1.9643305540084839],
+                [-1.2163853645324707, 0.14608727395534515],
+                [-2.3030710220336914, -0.37558120489120483],
+                [0.9232977628707886, 2.1843791007995605],
+                [-0.1989777386188507, 1.651851773262024],
+                [-0.714374840259552, -0.39365994930267334],
+                [-0.7805715799331665, -2.099881887435913],
+                [0.9015759229660034, -1.7053706645965576],
+                [0.1033422127366066, 1.5256654024124146],
+                [-1.8773194551467896, 2.324174165725708],
+                [1.9227174520492554, 2.7441604137420654],
+                [-0.5994020104408264, 0.23984014987945557],
+                [1.3496100902557373, -0.9126054644584656],
+                [-0.8765304088592529, -3.1877026557922363],
+                [-1.2040035724639893, -1.5169521570205688],
+                [1.4261796474456787, 2.150200128555298],
+                [1.463774561882019, 1.6656692028045654],
+                [0.20364105701446533, -0.4988172650337219],
+                [0.5195154547691345, -0.24067887663841248],
+                [-1.1116786003112793, -1.1599653959274292],
+                [-0.8490808606147766, -0.1681060940027237],
+                [0.3189965784549713, -0.9641751646995544],
+                [-0.5664751529693604, -0.5951744318008423],
+                [-1.6347930431365967, -0.9137664437294006],
+                [0.44048091769218445, -0.47259435057640076],
+                [-2.147747039794922, 0.47442489862442017],
+                [1.834734320640564, 1.4462147951126099],
+                [1.1777573823928833, 1.0659226179122925],
+                [-0.9568989872932434, 0.09495053440332413],
+                [-1.838529348373413, 0.2950586676597595],
+                [-0.4800611734390259, 0.014894310384988785],
+                [-0.5235516428947449, -1.7687653303146362],
+                [2.0735011100769043, -0.8825281262397766],
+                [2.637502431869507, 0.8455678224563599],
+                [2.606602907180786, -0.7848446369171143],
+                [-1.1886937618255615, 0.9330510497093201],
+                [0.38082656264305115, 0.13328030705451965],
+                [0.6847941875457764, 0.7384101152420044],
+                [1.2638574838638306, -0.007309418171644211],
+                [0.18292222917079926, -1.22371244430542],
+                [0.8143821954727173, 1.4976691007614136],
+                [0.6571850776672363, 0.48368802666664124],
+                [-0.6991601586341858, 2.150190830230713],
+                [0.8101756572723389, 0.10206498205661774],
+                [-0.08768226951360703, -1.084917664527893],
+                [-0.7208092212677002, 0.03657956421375275],
+                [0.3211449086666107, 1.803687334060669],
+                [-0.7835946083068848, 1.6869111061096191],
+            ]
+        )
+    if (p, n) == (2, 64):
+        return torch.tensor(
+            [
+                [-2.7216711044311523, 0.14431366324424744],
+                [-0.766914427280426, 1.7193410396575928],
+                [-2.2575762271881104, 1.2476624250411987],
+                [1.233758807182312, -2.3560616970062256],
+                [0.8701965808868408, -0.2649352252483368],
+                [1.4506438970565796, 2.1776366233825684],
+                [-0.06305818259716034, 1.9049758911132812],
+                [2.536226511001587, 0.563927412033081],
+                [0.4599496126174927, -1.8745561838150024],
+                [-1.900517225265503, -0.30703988671302795],
+                [0.09386251866817474, 0.8755807280540466],
+                [1.946500539779663, -0.6743080615997314],
+                [2.1338934898376465, 1.4581491947174072],
+                [0.9429940581321716, -0.8038390278816223],
+                [2.0697755813598633, -1.614896535873413],
+                [0.772676408290863, 0.22017823159694672],
+                [1.0689979791641235, -1.525044322013855],
+                [0.6813604831695557, 1.1345642805099487],
+                [0.4706456661224365, 2.606626272201538],
+                [-1.294018030166626, -0.4372096061706543],
+                [-0.09134224057197571, 0.4610418677330017],
+                [-0.7907772064208984, -0.48412787914276123],
+                [0.060459110885858536, -0.9172890186309814],
+                [-0.5855047702789307, 2.56172513961792],
+                [0.11484206467866898, -2.659848213195801],
+                [-1.5893300771713257, 2.188580274581909],
+                [1.6750942468643188, 0.7089915871620178],
+                [-0.445697546005249, 0.7452405095100403],
+                [-1.8539940118789673, -1.8377939462661743],
+                [-1.5791912078857422, -1.017285943031311],
+                [-1.030419945716858, -1.5746369361877441],
+                [-1.9511750936508179, 0.43696075677871704],
+                [-0.3446580767631531, -1.8953213691711426],
+                [-1.4219647645950317, 0.7676230669021606],
+                [-0.9191089272499084, 0.5021472573280334],
+                [0.20464491844177246, 1.3684605360031128],
+                [0.5402919054031372, 0.6699410676956177],
+                [1.8903915882110596, 0.03638288006186485],
+                [0.4723062515258789, -0.6216739416122437],
+                [-0.41345009207725525, -0.22752176225185394],
+                [2.7119064331054688, -0.5111885070800781],
+                [1.065286636352539, 0.6950305700302124],
+                [0.40629103779792786, -0.14339995384216309],
+                [1.2815024852752686, 0.17108257114887238],
+                [0.01785222627222538, -0.43778058886528015],
+                [0.054590027779340744, -1.4225547313690186],
+                [0.3076786696910858, 0.30697619915008545],
+                [-0.9498570561408997, -0.9576997756958008],
+                [-2.4640724658966064, -0.9660449028015137],
+                [1.3714425563812256, -0.39760473370552063],
+                [-0.4857747256755829, 0.2386789172887802],
+                [1.2797833681106567, 1.3097363710403442],
+                [0.5508887767791748, -1.1777795553207397],
+                [-1.384316325187683, 0.1465839296579361],
+                [-0.46556955575942993, -1.2442727088928223],
+                [-0.3915477693080902, -0.7319604158401489],
+                [-1.4005504846572876, 1.3890998363494873],
+                [-0.8647305965423584, 1.0617644786834717],
+                [-0.8901953101158142, -0.01650036871433258],
+                [-0.9893633723258972, -2.4662880897521973],
+                [1.445534110069275, -1.049334168434143],
+                [-0.041650623083114624, 0.012734669260680676],
+                [-0.3302375078201294, 1.26217782497406],
+                [0.6934980154037476, 1.7714335918426514],
+            ]
+        )
+    elif (p, n) == (2, 16):
+        return torch.tensor(
+            [
+                [-0.8996632695198059, -1.6360418796539307],
+                [-0.961183488368988, 1.5999565124511719],
+                [-1.882026195526123, 0.678778350353241],
+                [0.36300793290138245, -1.9667866230010986],
+                [-0.6814072728157043, -0.576818585395813],
+                [0.7270012497901917, 0.6186859607696533],
+                [0.3359416127204895, 1.8371193408966064],
+                [1.859930396080017, 0.036668598651885986],
+                [0.17208248376846313, -0.9401724338531494],
+                [-1.7599700689315796, -0.6244229674339294],
+                [-0.8993809223175049, 0.32267823815345764],
+                [0.839488685131073, -0.3017036020755768],
+                [1.5314953327178955, 1.2942044734954834],
+                [-0.0011779458727687597, 0.00022069070837460458],
+                [1.4274526834487915, -1.207889199256897],
+                [-0.16123905777931213, 0.8787511587142944],
+            ]
+        )
+    elif (p, n) == (1, 16):
+        return torch.tensor(
+            [
+                [-2.7325894832611084],
+                [-2.069017171859741],
+                [-1.6180464029312134],
+                [-1.2562311887741089],
+                [-0.9423404335975647],
+                [-0.6567591428756714],
+                [-0.38804829120635986],
+                [-0.12839503586292267],
+                [0.12839503586292267],
+                [0.38804829120635986],
+                [0.6567591428756714],
+                [0.9423404335975647],
+                [1.2562311887741089],
+                [1.6180464029312134],
+                [2.069017171859741],
+                [2.7325894832611084],
+            ]
+        )
+    elif (p, n) == (1, 8):
+        return torch.tensor(
+            [
+                [-2.1519455909729004],
+                [-1.3439092636108398],
+                [-0.7560052871704102],
+                [-0.2450941801071167],
+                [0.2450941801071167],
+                [0.7560052871704102],
+                [1.3439092636108398],
+                [2.1519455909729004],
+            ]
+        )
+    elif (p, n) == (1, 4):
+        return torch.tensor([[-1.5104175806045532], [-0.4527800381183624], [0.4527800381183624], [1.5104175806045532]])
+    else:
+        raise NotImplementedError(f"Unsupported p={p}, n={n}")
+
+
+def quantize_with_higgs(weight, bits: int = 4, p: int = 2, group_size: int = 256, hadamard_size: int = 1024):
+    assert len(weight.shape) == 2, "Only 2D weights are supported for now"
+
+    grid = get_higgs_grid(p, 2 ** (p * bits)).to(weight.device)
+    grid_norm_2 = torch.linalg.norm(grid, axis=-1) ** 2
+
+    device = weight.device
+    dtype = weight.dtype
+    weight = weight.to(copy=True, dtype=torch.float32)
+    # Pad to Hadamard transform size
+    weight = pad_to_block(weight, [1], hadamard_size)
+
+    # Scale and Hadamard transform
+    mult = weight.shape[1] // hadamard_size
+    weight = weight.reshape(-1, mult, hadamard_size)
+    scales = torch.linalg.norm(weight, axis=-1)
+    weight = hadamard_transform(weight, 1) / scales[:, :, None]
+
+    # Pad to edenn_d and project
+    weight = pad_to_block(weight, [2], p).reshape(weight.shape[0], mult, -1, p)
+
+    # Quantize
+    codes = torch.empty(weight.shape[:-1], device=device, dtype=torch.uint8)
+    for i in range(0, weight.shape[0], 16):
+        codes[i : i + 16] = torch.argmax(2 * weight[i : i + 16] @ grid.T - grid_norm_2, dim=-1).to(torch.uint8)
+    del weight
+
+    codes = codes.reshape(codes.shape[0], -1)
+    scales = scales / sqrt(hadamard_size)
+
+    weight, scales, tables, tables2, tune_metadata = prepare_data_transposed(
+        codes,
+        torch.repeat_interleave(scales.to(dtype), hadamard_size // group_size, dim=1),
+        grid.to(dtype),
+        num_bits=bits,
+        group_size=group_size,
+        vector_size=p,
+        dtype=dtype,
+        device=device,
+        check_correctness=False,
+    )
+
+    return {
+        "weight": weight,
+        "scales": scales,
+        "tables": tables,
+        "tables2": tables2.view(dtype=torch.float16),
+        "tune_metadata": tune_metadata,
+    }
+
+
+class HiggsLinear(torch.nn.Module):
+    def __init__(
+        self,
+        in_features: int,
+        out_features: int,
+        num_bits: int,
+        bias=True,
+        dtype: torch.dtype = None,
+        device: torch.device = None,
+        group_size: int = 256,
+        hadamard_size: int = 1024,
+    ):
+        super().__init__()
+        self.in_features = in_features
+        self.out_features = out_features
+        self.num_bits = num_bits
+        self.group_size = group_size
+        self.hadamard_size = hadamard_size
+
+        assert in_features % group_size == 0
+        assert num_bits in [2, 3, 4]
+
+        self.weight = nn.Parameter(
+            torch.empty((out_features * num_bits // 16, in_features), dtype=torch.int16, device=device),
+            requires_grad=False,
+        )
+        self.scales = nn.Parameter(
+            torch.empty((out_features, in_features // group_size), dtype=dtype, device=device), requires_grad=False
+        )
+        self.tables = nn.Parameter(torch.empty((2**num_bits,), dtype=dtype, device=device), requires_grad=False)
+        self.tables2 = nn.Parameter(
+            torch.empty((2**num_bits, 2**num_bits, 2), dtype=dtype, device=device), requires_grad=False
+        )
+
+        if bias:
+            self.bias = nn.Parameter(torch.empty(out_features, device=device, dtype=dtype), requires_grad=False)
+        else:
+            self.register_parameter("bias", None)
+
+        self.workspace = None  # must be set externally to be reused among layers
+        self.tune_metadata: TuneMetaData = None  # must be set externally because architecture dependent
+
+    def forward(self, x):
+        x = pad_to_block(x, [-1], self.hadamard_size)
+
+        if self.workspace is None:
+            raise Exception("Workspace must be set before calling forward")
+
+        return qgemm_v2(
+            x,
+            self.weight,
+            self.scales,
+            self.tables,
+            self.tables2.view(dtype=torch.float32),
+            self.workspace,
+            self.tune_metadata,
+            hadamard_size=self.hadamard_size,
+        )
+
+
+def _replace_with_higgs_linear(
+    model, quantization_config=None, current_key_name=None, modules_to_not_convert=None, has_been_replaced=False
+):
+    from accelerate import init_empty_weights
+
+    for name, module in model.named_children():
+        if current_key_name is None:
+            current_key_name = []
+        current_key_name.append(name)
+
+        if isinstance(module, nn.Linear):
+            current_key_name_str = ".".join(current_key_name)
+            if not any(current_key_name_str.endswith(key) for key in modules_to_not_convert):
+                with init_empty_weights():
+                    in_features = module.in_features
+                    out_features = module.out_features
+                    # Original size is [3072, 4096]. But after `HiggsLinear`, this is
+                    # [768, 4096]. 🤯
+                    if name == "context_embedder":
+                        print(f"{in_features=}, {out_features=}")
+                    model._modules[name] = HiggsLinear(
+                        in_features,
+                        out_features,
+                        bias=module.bias is not None,
+                        num_bits=quantization_config.bits,
+                        hadamard_size=quantization_config.hadamard_size,
+                        group_size=quantization_config.group_size,
+                    )
+                    if name == "context_embedder":
+                        print(model._modules[name].weight.shape)
+                    has_been_replaced = True
+
+                    # Store the module class in case we need to transpose the weight later
+                    model._modules[name].source_cls = type(module)
+                    # Force requires grad to False to avoid unexpected errors
+                    model._modules[name].requires_grad_(False)
+        if len(list(module.children())) > 0:
+            _, has_been_replaced = _replace_with_higgs_linear(
+                module,
+                quantization_config=quantization_config,
+                current_key_name=current_key_name,
+                modules_to_not_convert=modules_to_not_convert,
+                has_been_replaced=has_been_replaced,
+            )
+        # Remove the last key for recursion
+        current_key_name.pop(-1)
+
+    return model, has_been_replaced
+
+
+def replace_with_higgs_linear(
+    model,
+    quantization_config=None,
+    current_key_name=None,
+    has_been_replaced=False,
+):
+    """
+    Public method that recursively replaces the Linear layers of the given model with HIGGS quantized layers.
+    `accelerate` is needed to use this method. Returns the converted model and a boolean that indicates if the
+    conversion has been successful or not.
+
+    Args:
+        model (`torch.nn.Module`):
+            The model to convert, can be any `torch.nn.Module` instance.
+        quantization_config (`HiggsConfig`):
+            The quantization config object that contains the quantization parameters.
+        current_key_name (`list`, *optional*):
+            A list that contains the current key name. This is used for recursion and should not be passed by the user.
+        has_been_replaced (`bool`, *optional*):
+            A boolean that indicates if the conversion has been successful or not. This is used for recursion and
+            should not be passed by the user.
+    """
+    modules_to_not_convert = quantization_config.modules_to_not_convert or []
+    model, _ = _replace_with_higgs_linear(
+        model, quantization_config, current_key_name, modules_to_not_convert, has_been_replaced
+    )
+
+    has_been_replaced = any(isinstance(replaced_module, HiggsLinear) for _, replaced_module in model.named_modules())
+    if not has_been_replaced:
+        logger.warning(
+            "You are loading your model in Higgs but no linear modules were found in your model."
+            " Please double check your model architecture, or submit an issue on github if you think this is"
+            " a bug."
+        )
+
+    return model
+
+
+def dequantize_higgs(model, current_key_name=None):
+    """
+    Dequantizes the HiggsLinear layers in the given model by replacing them with standard torch.nn.Linear layers.
+
+    Args:
+        model (torch.nn.Module): The model containing HiggsLinear layers to be dequantized.
+        current_key_name (list, optional):
+            A list to keep track of the current module names during recursion. Defaults to None.
+    Returns:
+        torch.nn.Module: The model with HiggsLinear layers replaced by torch.nn.Linear layers.
+    """
+
+    with torch.no_grad():
+        for name, module in model.named_children():
+            if current_key_name is None:
+                current_key_name = []
+            current_key_name.append(name)
+
+            if isinstance(module, HiggsLinear):
+                in_features = module.in_features
+                out_features = module.out_features
+
+                model._modules[name] = torch.nn.Linear(
+                    in_features,
+                    out_features,
+                    bias=module.bias is not None,
+                    device=module.scales.device,
+                    dtype=module.scales.dtype,
+                )
+
+                model._modules[name].weight.data = module(
+                    torch.eye(in_features, device=module.scales.device, dtype=module.scales.dtype)
+                ).T.contiguous()
+
+            if len(list(module.children())) > 0:
+                _ = dequantize_higgs(
+                    module,
+                    current_key_name=current_key_name,
+                )
+            # Remove the last key for recursion
+            current_key_name.pop(-1)
+        return model

src/diffusers/quantizers/quantization_config.py

@@ -46,6 +46,7 @@ class QuantizationMethod(str, Enum):
     GGUF = "gguf"
     TORCHAO = "torchao"
     QUANTO = "quanto"
+    HIGGS = "higgs"
 
 
 if is_torchao_available():
@@ -724,3 +725,62 @@ class QuantoConfig(QuantizationConfigMixin):
         accepted_weights = ["float8", "int8", "int4", "int2"]
         if self.weights_dtype not in accepted_weights:
             raise ValueError(f"Only support weights in {accepted_weights} but found {self.weights_dtype}")
+
+
+@dataclass
+class HiggsConfig(QuantizationConfigMixin):
+    """
+    HiggsConfig is a configuration class for quantization using the HIGGS method.
+
+    Args:
+        bits (int, *optional*, defaults to 4):
+            Number of bits to use for quantization. Can be 2, 3 or 4. Default is 4.
+        p (int, *optional*, defaults to 2):
+            Quantization grid dimension. 1 and 2 are supported. 2 is always better in practice. Default is 2.
+        modules_to_not_convert (`list`, *optional*, default to ["lm_head"]):
+            List of linear layers that should not be quantized.
+        hadamard_size (int, *optional*, defaults to 512):
+            Hadamard size for the HIGGS method. Default is 512. Input dimension of matrices is padded to this value.
+            Decreasing this below 512 will reduce the quality of the quantization.
+        group_size (int, *optional*, defaults to 256):
+            Group size for the HIGGS method. Can be 64, 128 or 256. Decreasing it barely affects the performance.
+            Default is 256. Must be a divisor of hadamard_size.
+        tune_metadata ('dict', *optional*, defaults to {}):
+            Module-wise metadata (gemm block shapes, GPU metadata, etc.) for saving the kernel tuning results. Default
+            is an empty dictionary. Is set automatically during tuning.
+    """
+
+    def __init__(
+        self,
+        bits: int = 4,
+        p: int = 2,
+        modules_to_not_convert: Optional[list[str]] = None,
+        hadamard_size: int = 512,
+        group_size: int = 256,
+        tune_metadata: Optional[dict[str, Any]] = None,
+        **kwargs,
+    ):
+        if tune_metadata is None:
+            tune_metadata = {}
+        self.quant_method = QuantizationMethod.HIGGS
+        self.bits = bits
+        self.p = p
+        self.modules_to_not_convert = modules_to_not_convert
+        self.hadamard_size = hadamard_size
+        self.group_size = group_size
+        self.tune_metadata = tune_metadata
+
+        self.post_init()
+
+    def post_init(self):
+        r"""
+        Safety checker that arguments are correct - also replaces some NoneType arguments with their default values.
+        """
+        if self.bits not in [2, 3, 4]:
+            raise ValueError("bits must be 2, 3, or 4")
+        if self.p not in [1, 2]:
+            raise ValueError("p must be 1 or 2. 2 is always better in practice")
+        if self.group_size not in [64, 128, 256]:
+            raise ValueError("group_size must be 64, 128, or 256")
+        if self.hadamard_size % self.group_size != 0:
+            raise ValueError("hadamard_size must be divisible by group_size")