Add new quant method (#32047)

* Add new quant method

* update

* fix multi-device

* add test

* add offload

* style

* style

* add simple example

* initial doc

* docstring

* style again

* works ?

* better docs

* switch to non persistant

* remove print

* fix init

* code review

docs/source/en/quantization/fbgemm_fp8.md

@@ -0,0 +1,58 @@
+<!--Copyright 2024 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
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+http://www.apache.org/licenses/LICENSE-2.0
+
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+
+⚠️ Note that this file is in Markdown but contain specific syntax for our doc-builder (similar to MDX) that may not be
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+
+-->
+
+# FBGEMM FP8
+
+With FBGEMM FP8 quantization method, you can quantize your model in FP8 (W8A8):
+- the weights will be quantized in 8bit (FP8) per channel
+- the activation will be quantized in 8bit (FP8) per token
+
+It relies on the [FBGEMM](https://github.com/pytorch/FBGEMM) library which provides efficient low-precision general matrix multiplication for small batch sizes and support for accuracy-loss minimizing techniques such as row-wise quantization and outlier-aware quantization. 
+
+> [!TIP]
+> You need a GPU with compute capability>=9 (e.g. H100) 
+
+Before you begin, make sure the following libraries are installed with their latest version:
+
+```bash
+pip install --upgrade accelerate fbgemm-gpu torch
+```
+
+If you are having issues with fbgemm-gpu and torch library, you might need to install the nighlty release. You can follow the instruction [here](https://pytorch.org/FBGEMM/fbgemm_gpu-development/InstallationInstructions.html#fbgemm-gpu-install-libraries:~:text=found%20here.-,Install%20the%20FBGEMM_GPU%20Package,-Install%20through%20PyTorch)
+
+
+```py
+from transformers import FbgemmFp8Config, AutoModelForCausalLM, AutoTokenizer
+
+model_name = "meta-llama/Meta-Llama-3-8B"
+quantization_config = FbgemmFp8Config()
+quantized_model = AutoModelForCausalLM.from_pretrained(model_name, device_map="auto", quantization_config=quantization_config)
+
+tokenizer = AutoTokenizer.from_pretrained(model_name)
+input_text = "What are we having for dinner?"
+input_ids = tokenizer(input_text, return_tensors="pt").to("cuda")
+
+output = quantized_model.generate(**input_ids, max_new_tokens=10)
+print(tokenizer.decode(output[0], skip_special_tokens=True))
+```
+
+A quantized model can be saved via "saved_pretrained" and be reused again via the "from_pretrained".
+
+```py
+quant_path = "/path/to/save/quantized/model"
+model.save_pretrained(quant_path)
+model = AutoModelForCausalLM.from_pretrained(quant_path, device_map="auto")
+```

docs/source/en/quantization/overview.md

@@ -55,4 +55,5 @@ Use the table below to help you decide which quantization method to use.
 | [GPTQ](./gptq)                                | 🔴                       | 🔴   | 🟢        | 🟢              | 🔴                     | 🔴                       | 2 - 3 - 4 - 8          | 🟢                                   | 🟢            | 🟢                      | https://github.com/AutoGPTQ/AutoGPTQ        |
 | [HQQ](./hqq)                                 | 🟢                       | 🟢    | 🟢        | 🔴              | 🔴                     | 🟢                       | 1 - 8          | 🟢                                   | 🔴            | 🟢                      | https://github.com/mobiusml/hqq/            |
 | [Quanto](./quanto)                              | 🟢                       | 🟢   | 🟢        | 🔴              | 🟢                     | 🟢                       | 2 / 4 / 8      | 🔴                                   | 🔴            | 🟢                      | https://github.com/huggingface/quanto       |
+| [FBGEMM_FP8](./fbgemm_fp8.md)                              | 🟢                       | 🔴    | 🟢        | 🔴              | 🔴                      | 🔴                        | 8      | 🔴                                   | 🟢            | 🟢                      | https://github.com/pytorch/FBGEMM       |