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Xuan Liao

PROFILE

Xuan Liao

Xuan Liao developed and optimized quantized model inference and transformer attention workflows across the pytorch/ao, pytorch/pytorch, and intel/ai-reference-models repositories. He implemented INT8 and FP8 Scaled Dot Product Attention (SDPA) CPU kernels, leveraging AVX-512 vectorization and C++ for efficient low-precision computation. His work included memory management improvements, autotuning for large models, and integration with PyTorch quantization utilities, resulting in faster, more scalable inference and training on commodity hardware. Xuan also addressed reliability by expanding unit test coverage and fixing edge-case bugs, demonstrating depth in performance optimization, distributed computing, and robust Python and C++ development for machine learning systems.

Overall Statistics

Feature vs Bugs

78%Features

Repository Contributions

21Total
Bugs
4
Commits
21
Features
14
Lines of code
14,416
Activity Months6

Work History

September 2025

5 Commits • 4 Features

Sep 1, 2025

September 2025 focused on expanding FP8/INT8 quantization on CPU and strengthening stability across PyTorch repos. Delivered CPU-side FP8 SDPA support with new kernels and tests, fixed FP8 SDPA compilation issues for PyTorch, and optimized INT8 SDPA kernels for memory and speed, enabling faster quantized inference. Expanded TorchAO and PyTorch quantization capabilities (transpose/pack optimization, aten.reshape.default support) with updated measurement metrics, improving performance visibility. Result: higher throughput for quantized models, broader hardware compatibility, and stronger CI/test coverage.

August 2025

1 Commits

Aug 1, 2025

August 2025 monthly summary for pytorch/ao: Focused on stabilizing Int8 SDPA fusion tests and improving test coverage. Delivered a targeted unit test fix addressing an assertion error and expanded coverage by adding a new operation to the test suite, enhancing reliability of the feature in CI and future releases. Resulted in more stable CI signals, reduced regression risk, and clearer validation for the Int8 SDPA fusion workflow.

July 2025

6 Commits • 4 Features

Jul 1, 2025

July 2025 performance and reliability update: Delivered CPU-focused optimizations and reliability improvements across PyTorch and AI reference models, boosting throughput for 8-bit quantized workloads and transformer attention, while hardening edge cases and test coverage. Key features include AVX-512 INT8 path, Grouped Query Attention (GQA) support in CPU Flash Attention, INT8 SDPA manual transpose/packing, and autotuning for ViT/BERT large models. Major bugs addressed include FakeTensorMode safety guards to prevent runtime errors with non-Fake inputs and fixes for bf16 memory access and None handling in attention backward paths. These contributions collectively improve performance, energy efficiency, and stability for CPU ML workloads, enabling more scalable inference and training on commodity hardware. Technologies demonstrated include AVX-512 vectorization, int8 quantization, sbgemm, GQA, Flash Attention, and autotuning workflows.

June 2025

4 Commits • 3 Features

Jun 1, 2025

June 2025 performance summary: Delivered cross-repo performance optimizations and distributed computing enhancements across intel/ai-reference-models, pytorch/ao, and pytorch/pytorch. Key outcomes include notable inference performance gains on CPU through INT8 SDPA quantization, AVX512-accelerated C++ kernels, and AOTI shims for distributed collectives, with accompanying tests and deployment-ready updates. These workstreams improved throughput, reduced latency, and expanded hardware support, contributing to faster model iteration and scalable distributed training/inference.

May 2025

2 Commits • 1 Features

May 1, 2025

Concise monthly summary for 2025-05 focused on the INT8 SDPA path for CPU in the pytorch/ao repo. Delivered a complete INT8 Scaled Dot Product Attention (SDPA) implementation and CPU template to accelerate quantized models, with new kernels, memory management optimizations, and integration with TorchAO quantization utilities. Added comprehensive tests to validate compatibility across input types and configurations, and re-landed key PRs to stabilize the feature set.

April 2025

3 Commits • 2 Features

Apr 1, 2025

April 2025 performance highlights across intel/ai-reference-models and pytorch/ao. Focused on quantization-driven performance and accuracy improvements: implemented INT8 quantization with refined evaluation logic, fixed a training/evaluation accuracy issue, and introduced a comprehensive INT8 SDPA CPU path with new kernels, framework integration, and tests, enabling faster, more efficient quantized inference across CPU workloads.

Activity

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Quality Metrics

Correctness94.2%
Maintainability81.0%
Architecture89.6%
Performance92.4%
AI Usage42.0%

Skills & Technologies

Programming Languages

C++PythonShellbash

Technical Skills

AVX-512AVX512Bash ScriptingC++C++ developmentC++ programmingCPU DevelopmentCPU optimizationCUDADeep LearningDevOpsMachine LearningModel OptimizationNumerical computingPerformance Optimization

Repositories Contributed To

3 repos

Overview of all repositories you've contributed to across your timeline

pytorch/ao

Apr 2025 Sep 2025
6 Months active

Languages Used

C++Python

Technical Skills

CPU optimizationPyTorchdeep learningquantizationC++ developmentPython programming

pytorch/pytorch

Jun 2025 Sep 2025
3 Months active

Languages Used

C++Python

Technical Skills

C++ developmentPython testingdistributed computingunit testingAVX-512C++

intel/ai-reference-models

Apr 2025 Jul 2025
3 Months active

Languages Used

PythonShellbash

Technical Skills

Deep LearningMachine LearningModel OptimizationPyTorchBash ScriptingDevOps

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