Add pt2e tutorials to torchao doc page (#2384)

Summary:
att, after we migrate pt2e quant code from pytorch to torchao, now we
also want to migrate the docs as well

Test Plan:
check generated docs

Reviewers:

Subscribers:

Tasks:

Tags:

Author: jerryzh168

docs/source/index.rst

@@ -12,6 +12,7 @@ for an overall introduction to the library and recent highlight and updates.
    :caption: Getting Started
 
    quick_start
+   pt2e_quant
 
 .. toctree::
    :glob:
@@ -35,11 +36,23 @@ for an overall introduction to the library and recent highlight and updates.
 .. toctree::
    :glob:
    :maxdepth: 1
-   :caption: Tutorials
+   :caption: Eager Quantization Tutorials
 
    serialization
    subclass_basic
    subclass_advanced
    static_quantization
    pretraining
    torchao_vllm_integration
+
+.. toctree::
+   :glob:
+   :maxdepth: 1
+   :caption: PT2E Quantization Tutorials
+
+   tutorials_source/pt2e_quant_ptq
+   tutorials_source/pt2e_quant_qat
+   tutorials_source/pt2e_quant_x86_inductor
+   tutorials_source/pt2e_quant_xpu_inductor
+   tutorials_source/pt2e_quantizer
+   tutorials_source/openvino_quantizer

docs/source/quick_start.rst

@@ -29,20 +29,20 @@ First, let's set up our toy model:
 
   import copy
   import torch
-  
+
   class ToyLinearModel(torch.nn.Module):
       def __init__(self, m: int, n: int, k: int):
           super().__init__()
           self.linear1 = torch.nn.Linear(m, n, bias=False)
           self.linear2 = torch.nn.Linear(n, k, bias=False)
-  
+
       def forward(self, x):
           x = self.linear1(x)
           x = self.linear2(x)
           return x
-  
+
   model = ToyLinearModel(1024, 1024, 1024).eval().to(torch.bfloat16).to("cuda")
-  
+
   # Optional: compile model for faster inference and generation
   model = torch.compile(model, mode="max-autotune", fullgraph=True)
   model_bf16 = copy.deepcopy(model)
@@ -99,18 +99,18 @@ it is also much faster!
       benchmark_model,
       unwrap_tensor_subclass,
   )
-  
+
   # Temporary workaround for tensor subclass + torch.compile
   # Only needed for torch version < 2.5
   if not TORCH_VERSION_AT_LEAST_2_5:
       unwrap_tensor_subclass(model)
-  
+
   num_runs = 100
   torch._dynamo.reset()
   example_inputs = (torch.randn(1, 1024, dtype=torch.bfloat16, device="cuda"),)
   bf16_time = benchmark_model(model_bf16, num_runs, example_inputs)
   int4_time = benchmark_model(model, num_runs, example_inputs)
-  
+
   print("bf16 mean time: %0.3f ms" % bf16_time)
   print("int4 mean time: %0.3f ms" % int4_time)
   print("speedup: %0.1fx" % (bf16_time / int4_time))
@@ -121,6 +121,87 @@ On a single A100 GPU with 80GB memory, this prints::
   int4 mean time: 4.410 ms
   speedup: 6.9x
 
+PyTorch 2 Export Quantization
+=============================
+PyTorch 2 Export Quantization is a full graph quantization workflow mostly for static quantization. It targets hardwares that requires both input and output activation and weight to be quantized and relies of recognizing an operator pattern to make quantization decisions (such as linear - relu). PT2E quantization produces a pattern with quantize and dequantize ops inserted around the operators and during lowering quantized operator patterns will be fused into real quantized ops. Currently there are two typical lowering paths, 1. torch.compile through inductor lowering 2. ExecuTorch through delegation
+
+Here we show an example with X86InductorQuantizer
+
+API Example::
+
+  import torch
+  from torchao.quantization.pt2e.quantize_pt2e import prepare_pt2e
+  from torch.export import export
+  from torchao.quantization.pt2e.quantizer.x86_inductor_quantizer import (
+      X86InductorQuantizer,
+      get_default_x86_inductor_quantization_config,
+  )
+
+  class M(torch.nn.Module):
+      def __init__(self):
+          super().__init__()
+          self.linear = torch.nn.Linear(5, 10)
+
+     def forward(self, x):
+         return self.linear(x)
+
+  # initialize a floating point model
+  float_model = M().eval()
+
+  # define calibration function
+  def calibrate(model, data_loader):
+      model.eval()
+      with torch.no_grad():
+          for image, target in data_loader:
+              model(image)
+
+  # Step 1. program capture
+  m = export(m, *example_inputs).module()
+  # we get a model with aten ops
+
+  # Step 2. quantization
+  # backend developer will write their own Quantizer and expose methods to allow
+  # users to express how they
+  # want the model to be quantized
+  quantizer = X86InductorQuantizer()
+  quantizer.set_global(xiq.get_default_x86_inductor_quantization_config())
+
+  # or prepare_qat_pt2e for Quantization Aware Training
+  m = prepare_pt2e(m, quantizer)
+
+  # run calibration
+  # calibrate(m, sample_inference_data)
+  m = convert_pt2e(m)
+
+  # Step 3. lowering
+  # lower to target backend
+
+  # Optional: using the C++ wrapper instead of default Python wrapper
+  import torch._inductor.config as config
+  config.cpp_wrapper = True
+
+  with torch.no_grad():
+      optimized_model = torch.compile(converted_model)
+
+      # Running some benchmark
+      optimized_model(*example_inputs)
+
+
+Please follow these tutorials to get started on PyTorch 2 Export Quantization:
+
+Modeling Users:
+
+- `PyTorch 2 Export Post Training Quantization <https://docs.pytorch.org/ao/stable/tutorial_source/pt2e_quant_ptq.html>`_
+- `PyTorch 2 Export Quantization Aware Training <ttps://docs.pytorch.org/ao/stable/tutorial_source/pt2e_quant_qat.html>`_
+- `PyTorch 2 Export Post Training Quantization with X86 Backend through Inductor <https://docs.pytorch.org/ao/stable/tutorial_source/pt2e_quant_x86_inductor.html>`_
+- `PyTorch 2 Export Post Training Quantization with XPU Backend through Inductor <https://docs.pytorch.org/ao/stable/tutorial_source/pt2e_quant_xpu_inductor.html>`_
+- `PyTorch 2 Export Quantization for OpenVINO torch.compile Backend <https://docs.pytorch.org/ao/stable/tutorial_source/pt2e_quant_openvino.html>`_
+
+
+Backend Developers (please check out all Modeling Users docs as well):
+
+- `How to Write a Quantizer for PyTorch 2 Export Quantization <https://docs.pytorch.org/ao/stable/tutorial_source/pt2e_quantizer.html>`_
+
 
 Next Steps
 ==========