Add hybrid quantization for StableDiffusion pipelines

docs/source/optimization_ov.mdx

@@ -69,6 +69,23 @@ from optimum.intel import OVModelForCausalLM
 model = OVModelForCausalLM.from_pretrained(model_id, load_in_8bit=True)
 ```
 
+##  Hybrid quantization
+
+Traditional optimization methods like post-training 8-bit quantization do not work well for Stable Diffusion models and can lead to poor generation results. On the other hand, weight compression does not improve performance significantly when applied to Stable Diffusion models, as the size of activations is comparable to weights.
+The UNet model takes up most of the overall execution time of the pipeline. Thus, optimizing just one model brings substantial benefits in terms of inference speed while keeping acceptable accuracy without fine-tuning. Quantizing the rest of the diffusion pipeline does not significantly improve inference performance but could potentially lead to substantial degradation of accuracy.
+Therefore, the proposal is to apply quantization in *hybrid mode* for the UNet model and weight-only quantization for the rest of the pipeline components. The hybrid mode involves the quantization of weights in MatMul and Embedding layers, and activations of other layers, facilitating accuracy preservation post-optimization while reducing the model size.
+The `quantization_config` is utilized to define optimization parameters for optimizing the Stable Diffusion pipeline. To enable hybrid quantization, specify the quantization dataset in the `quantization_config`. Otherwise, weight-only quantization to a specified data type (8 tr 4 bits) is applied to UNet model.
+
+```python
+from optimum.intel import OVStableDiffusionPipeline, OVWeightQuantizationConfig
+
+model = OVStableDiffusionPipeline.from_pretrained(
+    model_id,
+    export=True,
+    quantization_config=OVWeightQuantizationConfig(bits=8, dataset="conceptual_captions"),
+)
+```
+
 <Tip warning={true}>
 
 `load_in_8bit` is enabled by default for the models larger than 1 billion parameters.

optimum/intel/openvino/configuration.py

@@ -167,7 +167,7 @@ class OVWeightQuantizationConfig(QuantizationConfigMixin):
 
         bits (`int`, defaults to 8):
             The number of bits to quantize to.
-        sym (`bool`, *optional*, defaults to `False`):
+        sym (`bool`, defaults to `False`):
             Whether to use symetric quantization.
         tokenizer (`str` or `PreTrainedTokenizerBase`, *optional*):
             The tokenizer used to process the dataset. You can pass either:
@@ -177,23 +177,24 @@ class OVWeightQuantizationConfig(QuantizationConfigMixin):
                     user or organization name, like `dbmdz/bert-base-german-cased`.
                 - A path to a *directory* containing vocabulary files required by the tokenizer, for instance saved
                     using the [`~PreTrainedTokenizer.save_pretrained`] method, e.g., `./my_model_directory/`.
-        dataset (`Union[List[str]]`, *optional*):
-            The dataset used for data-aware compression. You can provide your own dataset in a list of string or just use the
-            the one from the list ['wikitext2','c4','c4-new','ptb','ptb-new']
-        group_size (`int`, *optional*, defaults to 128):
-            The group size to use for quantization. Recommended value is 128 and -1 uses per-column quantization.
-        ratio (`float`, *optional*, defaults to 1.0):
+        dataset (`str or List[str]`, *optional*):
+            The dataset used for data-aware compression or quantization with NNCF. You can provide your own dataset
+            in a list of strings or just use the one from the list ['wikitext2','c4','c4-new','ptb','ptb-new'] for LLLMs
+            or ['conceptual_captions','laion/220k-GPT4Vision-captions-from-LIVIS','laion/filtered-wit'] for diffusion models.
+        ratio (`float`, defaults to 1.0):
             The ratio between baseline and backup precisions (e.g. 0.9 means 90% of layers quantized to INT4_ASYM
             and the rest to INT8_ASYM).
+        group_size (`int`, *optional*):
+            The group size to use for quantization. Recommended value is 128 and -1 uses per-column quantization.
         all_layers (`bool`, *optional*):
             Defines how many layers are compressed to 4-bits while the rest are kept in 8-bit presicion.
-        sensitivity_metric (`nncf.SensitivityMetric`, *optional*):
+        sensitivity_metric (`str`, *optional*):
             The sensitivity metric for assigning quantization precision to layers. In order to
             preserve the accuracy of the model, the more sensitive layers receives a higher precision.
-        awq (`bool`, *optional*):
-            Enables AWQ method to unify weight ranges and improve overall model accuracy.
-        ignored_scope (`nncf.IgnoredScope`, *optional*):
+        ignored_scope (`dict`, *optional*):
             An ignored scope that defined the list of model control flow graph nodes to be ignored during quantization.
+        num_samples (`int`, *optional*):
+            The maximum number of samples composing the calibration dataset.
 
     """
 
@@ -202,12 +203,13 @@ def __init__(
         bits: int = 8,
         sym: bool = False,
         tokenizer: Optional[Any] = None,
-        dataset: Optional[str] = None,
+        dataset: Optional[Union[str, List[str]]] = None,
         ratio: float = 1.0,
         group_size: Optional[int] = None,
         all_layers: Optional[bool] = None,
         sensitivity_metric: Optional[str] = None,
         ignored_scope: Optional[dict] = None,
+        num_samples: Optional[int] = None,
         **kwargs,
     ):
         self.bits = bits
@@ -219,6 +221,7 @@ def __init__(
         self.all_layers = all_layers
         self.sensitivity_metric = sensitivity_metric
         self.ignored_scope = ignored_scope
+        self.num_samples = num_samples
         self.quant_method = "default"  # TODO : enable AWQ after nncf v2.9.0 release
         self.post_init()
 
@@ -231,10 +234,16 @@ def post_init(self):
         if self.group_size is not None and self.group_size != -1 and self.group_size <= 0:
             raise ValueError("`group_size` must be greater than 0 or equal to -1")
         if self.dataset is not None and isinstance(self.dataset, str):
-            if self.dataset not in ["wikitext2", "c4", "c4-new", "ptb", "ptb-new"]:
+            llm_datasets = ["wikitext2", "c4", "c4-new", "ptb", "ptb-new"]
+            stable_diffusion_datasets = [
+                "conceptual_captions",
+                "laion/220k-GPT4Vision-captions-from-LIVIS",
+                "laion/filtered-wit",
+            ]
+            if self.dataset not in llm_datasets + stable_diffusion_datasets:
                 raise ValueError(
                     f"""You have entered a string value for dataset. You can only choose between
-                    ['wikitext2','c4','c4-new','ptb','ptb-new'], but we found {self.dataset}"""
+                    {llm_datasets} for LLLMs or {stable_diffusion_datasets} for diffusion models, but we found {self.dataset}"""
                 )
 
         if self.bits not in [4, 8]:

optimum/intel/openvino/modeling_decoder.py

@@ -635,7 +635,8 @@ def _from_pretrained(
                 # from optimum.gptq.utils import get_seqlen
 
                 # seqlen = get_seqlen(causal_model)
-                dataset = get_dataset(quantization_config.dataset, tokenizer, seqlen=32)
+                nsamples = quantization_config.num_samples if quantization_config.num_samples else 128
+                dataset = get_dataset(quantization_config.dataset, tokenizer, seqlen=32, nsamples=nsamples)
                 dataset = prepare_dataset(dataset)
                 quantization_config = copy.deepcopy(quantization_config)
                 quantization_config.dataset = nncf.Dataset(dataset, lambda x: causal_model.prepare_inputs(**x))

optimum/intel/openvino/modeling_diffusion.py

@@ -16,6 +16,7 @@
 import logging
 import os
 import shutil
+from copy import deepcopy
 from pathlib import Path
 from tempfile import TemporaryDirectory, gettempdir
 from typing import Any, Dict, List, Optional, Union
@@ -57,7 +58,13 @@
 from .configuration import OVConfig, OVWeightQuantizationConfig
 from .loaders import OVTextualInversionLoaderMixin
 from .modeling_base import OVBaseModel
-from .utils import ONNX_WEIGHTS_NAME, OV_TO_NP_TYPE, OV_XML_FILE_NAME, _print_compiled_model_properties
+from .utils import (
+    ONNX_WEIGHTS_NAME,
+    OV_TO_NP_TYPE,
+    OV_XML_FILE_NAME,
+    PREDEFINED_SD_DATASETS,
+    _print_compiled_model_properties,
+)
 
 
 core = Core()
@@ -274,9 +281,19 @@ def _from_pretrained(
                     kwargs[name] = load_method(new_model_save_dir)
 
         quantization_config = cls._prepare_weight_quantization_config(quantization_config, load_in_8bit)
-        unet = cls.load_model(
-            new_model_save_dir / DIFFUSION_MODEL_UNET_SUBFOLDER / unet_file_name, quantization_config
-        )
+
+        unet_path = new_model_save_dir / DIFFUSION_MODEL_UNET_SUBFOLDER / unet_file_name
+        if quantization_config is not None and quantization_config.dataset is not None:
+            # load the UNet model uncompressed to apply hybrid quantization further
+            unet = cls.load_model(unet_path)
+            # Apply weights compression to other `components` without dataset
+            weight_quantization_params = {
+                param: value for param, value in quantization_config.__dict__.items() if param != "dataset"
+            }
+            weight_quantization_config = OVWeightQuantizationConfig.from_dict(weight_quantization_params)
+        else:
+            weight_quantization_config = quantization_config
+            unet = cls.load_model(unet_path, weight_quantization_config)
 
         components = {
             "vae_encoder": new_model_save_dir / DIFFUSION_MODEL_VAE_ENCODER_SUBFOLDER / vae_encoder_file_name,
@@ -286,11 +303,29 @@ def _from_pretrained(
         }
 
         for key, value in components.items():
-            components[key] = cls.load_model(value, quantization_config) if value.is_file() else None
+            components[key] = cls.load_model(value, weight_quantization_config) if value.is_file() else None
 
         if model_save_dir is None:
             model_save_dir = new_model_save_dir
 
+        if quantization_config is not None and quantization_config.dataset is not None:
+            sd_model = cls(unet=unet, config=config, model_save_dir=model_save_dir, **components, **kwargs)
+
+            supported_pipelines = (
+                OVStableDiffusionPipeline,
+                OVStableDiffusionXLPipeline,
+                OVLatentConsistencyModelPipeline,
+            )
+            if not isinstance(sd_model, supported_pipelines):
+                raise NotImplementedError(f"Quantization in hybrid mode is not supported for {cls.__name__}")
+
+            nsamples = quantization_config.num_samples if quantization_config.num_samples else 200
+            unet_inputs = sd_model._prepare_unet_inputs(quantization_config.dataset, nsamples)
+
+            from .quantization import _hybrid_quantization
+
+            unet = _hybrid_quantization(sd_model.unet.model, weight_quantization_config, dataset=unet_inputs)
+
         return cls(
             unet=unet,
             config=config,
@@ -300,6 +335,62 @@ def _from_pretrained(
             **kwargs,
         )
 
+    def _prepare_unet_inputs(
+        self,
+        dataset: Union[str, List[Any]],
+        num_samples: int,
+        height: Optional[int] = None,
+        width: Optional[int] = None,
+        seed: Optional[int] = 42,
+        **kwargs,
+    ) -> Dict[str, Any]:
+        self.compile()
+
+        size = self.unet.config.get("sample_size", 64) * self.vae_scale_factor
+        height = height or min(size, 512)
+        width = width or min(size, 512)
+
+        if isinstance(dataset, str):
+            dataset = deepcopy(dataset)
+            available_datasets = PREDEFINED_SD_DATASETS.keys()
+            if dataset not in available_datasets:
+                raise ValueError(
+                    f"""You have entered a string value for dataset. You can only choose between
+                    {list(available_datasets)}, but the {dataset} was found"""
+                )
+
+            from datasets import load_dataset
+
+            dataset_metadata = PREDEFINED_SD_DATASETS[dataset]
+            dataset = load_dataset(dataset, split=dataset_metadata["split"], streaming=True).shuffle(seed=seed)
+            input_names = dataset_metadata["inputs"]
+            dataset = dataset.select_columns(list(input_names.values()))
+
+            def transform_fn(data_item):
+                return {inp_name: data_item[column] for inp_name, column in input_names.items()}
+
+        else:
+
+            def transform_fn(data_item):
+                return data_item if isinstance(data_item, (list, dict)) else [data_item]
+
+        from .quantization import InferRequestWrapper
+
+        calibration_data = []
+        self.unet.request = InferRequestWrapper(self.unet.request, calibration_data)
+
+        for inputs in dataset:
+            inputs = transform_fn(inputs)
+            if isinstance(inputs, dict):
+                self.__call__(**inputs, height=height, width=width)
+            else:
+                self.__call__(*inputs, height=height, width=width)
+            if len(calibration_data) > num_samples:
+                break
+
+        self.unet.request = self.unet.request.request
+        return calibration_data[:num_samples]
+
     @classmethod
     def _from_transformers(
         cls,

optimum/intel/openvino/quantization.py

@@ -16,6 +16,7 @@
 import inspect
 import logging
 import os
+from collections import deque
 from pathlib import Path
 from typing import Any, Callable, Dict, Optional, Tuple, Union
 
@@ -24,6 +25,7 @@
 import torch
 import transformers
 from nncf import CompressWeightsMode, IgnoredScope, NNCFConfig, SensitivityMetric
+from nncf.quantization.advanced_parameters import AdvancedSmoothQuantParameters
 from nncf.torch import create_compressed_model, register_default_init_args, register_module
 from nncf.torch.dynamic_graph.io_handling import wrap_nncf_model_inputs_with_objwalk
 from nncf.torch.initialization import PTInitializingDataLoader
@@ -550,7 +552,7 @@ def _remove_unused_columns(self, dataset: "Dataset"):
 
 def _weight_only_quantization(
     model: openvino.runtime.Model, quantization_config: Union[OVWeightQuantizationConfig, Dict]
-):
+) -> openvino.runtime.Model:
     config = quantization_config
     if isinstance(config, dict):
         config = OVWeightQuantizationConfig.from_dict(quantization_config)
@@ -564,7 +566,8 @@ def _weight_only_quantization(
 
         from optimum.gptq.data import get_dataset, prepare_dataset
 
-        dataset = get_dataset(config.dataset, tokenizer, seqlen=32)
+        nsamples = config.num_samples if config.num_samples else 128
+        dataset = get_dataset(config.dataset, tokenizer, seqlen=32, nsamples=nsamples)
         dataset = prepare_dataset(dataset)
 
     sensitivity_metric = None
@@ -590,4 +593,92 @@ def _weight_only_quantization(
         # awq=config.quant_method == "awq", # TODO : remove and add it back once nncf v2.9.0
         ignored_scope=ignored_scope,
         dataset=dataset,
+        # subset_size=config.num_samples if config.num_samples else 128, # TODO : enable from nncf v2.9.0
     )
+
+
+def _get_operation_const_op(operation, const_port_id: int):
+    node = operation.input_value(const_port_id).get_node()
+    queue = deque([node])
+    constant_node = None
+    allowed_propagation_types_list = ["Convert", "FakeQuantize", "Reshape"]
+
+    while len(queue) != 0:
+        curr_node = queue.popleft()
+        if curr_node.get_type_name() == "Constant":
+            constant_node = curr_node
+            break
+        if len(curr_node.inputs()) == 0:
+            break
+        if curr_node.get_type_name() in allowed_propagation_types_list:
+            queue.append(curr_node.input_value(0).get_node())
+
+    return constant_node
+
+
+def _is_embedding(node) -> bool:
+    allowed_types_list = ["f16", "f32", "f64"]
+    const_port_id = 0
+    input_tensor = node.input_value(const_port_id)
+    if input_tensor.get_element_type().get_type_name() in allowed_types_list:
+        const_node = _get_operation_const_op(node, const_port_id)
+        if const_node is not None:
+            return True
+
+    return False
+
+
+def _collect_ops_with_weights(model):
+    ops_with_weights = []
+    for op in model.get_ops():
+        if op.get_type_name() == "MatMul":
+            constant_node_0 = _get_operation_const_op(op, const_port_id=0)
+            constant_node_1 = _get_operation_const_op(op, const_port_id=1)
+            if constant_node_0 or constant_node_1:
+                ops_with_weights.append(op.get_friendly_name())
+        if op.get_type_name() == "Gather" and _is_embedding(op):
+            ops_with_weights.append(op.get_friendly_name())
+
+    return ops_with_weights
+
+
+def _hybrid_quantization(
+    model: openvino.runtime.Model, quantization_config: OVWeightQuantizationConfig, dataset: Dict[str, Any]
+) -> openvino.runtime.Model:
+    """
+    Quantize a model in hybrid mode with NNCF which means that we quantize:
+    weights of MatMul and Embedding layers and activations of other layers.
+    The optimization specifications defined in `quantization_config`.
+
+    Args:
+        model (`openvino.runtime.Model`):
+            The OpenVINO Runtime model for applying hybrid quantization.
+        quantization_config (`OVWeightQuantizationConfig`):
+            The configuration containing the parameters related to quantization.
+        dataset (`Dict[str, Any]`):
+            The dataset used for hybrid quantization.
+    Returns:
+        The OpenVINO Runtime model with applied hybrid quantization.
+    """
+    ops_to_compress = _collect_ops_with_weights(model)
+
+    ignored_scope = quantization_config.ignored_scope if isinstance(quantization_config.ignored_scope, dict) else {}
+    ptq_ignored_scope = nncf.IgnoredScope(**ignored_scope)
+    ptq_ignored_scope.names += ops_to_compress
+
+    wc_quantization_config = copy.deepcopy(quantization_config)
+    wc_quantization_config.ignored_scope = ignored_scope
+    wc_quantization_config.ignored_scope["types"] = ignored_scope.get("types", []) + ["Convolution"]
+    compressed_model = _weight_only_quantization(model, wc_quantization_config)
+
+    subset_size = quantization_config.num_samples if quantization_config.num_samples else 200
+    quantized_model = nncf.quantize(
+        model=compressed_model,
+        calibration_dataset=nncf.Dataset(dataset),
+        model_type=nncf.ModelType.TRANSFORMER,
+        ignored_scope=ptq_ignored_scope,
+        # The SQ algo should be disabled for MatMul nodes because their weights are already compressed
+        advanced_parameters=nncf.AdvancedQuantizationParameters(AdvancedSmoothQuantParameters(matmul=-1)),
+        subset_size=subset_size,
+    )
+    return quantized_model