
Chen Hao worked across TensorFlow, ROCm/xla, and AI-Hypercomputer/maxtext, building and refining GPU-accelerated deep learning features and infrastructure. He developed cross-memory-space sorting in ROCm/xla and enabled device-specific kernel execution in TensorFlow’s XLA, leveraging C++ and CUDA for high-performance computing. In maxtext, he improved FP8 quantization workflows by shifting from fake to direct quantization, enhancing numerical reliability and efficiency. Chen also addressed correctness in deterministic scatter operations, implementing fixes and optimizations in TensorFlow and Intel-tensorflow/xla. His work demonstrated strong algorithm design, rigorous testing, and a focus on performance optimization, contributing robust solutions to complex machine learning and compiler challenges.

December 2025 monthly summary focused on deterministic scatter improvements in the XLA GPU backend across Intel-tensorflow/xla and ROCm/tensorflow-upstream. Key outcomes include default enablement of the ScatterDeterminismExpander leading to substantial performance gains, a correctness fix for batched scatter after normalization, and cross-repo alignment with robust testing. Business value: improved reproducibility for batched attention and embedding lookups, faster training/inference, and reduced compute waste. Technologies demonstrated include XLA GPU compiler passes, BatchedGatherScatterNormalizer, FlattenIndices, and scatter_dims_to_operand_dims, along with test automation and cross-repo import workflows.
December 2025 monthly summary focused on deterministic scatter improvements in the XLA GPU backend across Intel-tensorflow/xla and ROCm/tensorflow-upstream. Key outcomes include default enablement of the ScatterDeterminismExpander leading to substantial performance gains, a correctness fix for batched scatter after normalization, and cross-repo alignment with robust testing. Business value: improved reproducibility for batched attention and embedding lookups, faster training/inference, and reduced compute waste. Technologies demonstrated include XLA GPU compiler passes, BatchedGatherScatterNormalizer, FlattenIndices, and scatter_dims_to_operand_dims, along with test automation and cross-repo import workflows.
October 2025: Delivered the Execute Device Kernel feature in XLA within the TensorFlow/TensorFlow repo, enabling embedding and execution of device-specific code inside JAX programs with dynamic compilation during JIT. This expands accelerator programming capabilities and provides a path toward more flexible and performant device kernels for ML workloads.
October 2025: Delivered the Execute Device Kernel feature in XLA within the TensorFlow/TensorFlow repo, enabling embedding and execution of device-specific code inside JAX programs with dynamic compilation during JIT. This expands accelerator programming capabilities and provides a path toward more flexible and performant device kernels for ML workloads.
September 2025 monthly summary for tensorflow/tensorflow: Delivered a critical correctness fix in ScatterDeterminismExpander addressing zero-index handling in scatter_set operations and prefix scan, preventing incorrect results and false matches caused by zero padding. Updated mask initialization and added tests to cover zero-padding edge cases. Related commits fixed shifting issues and updated the padded index value to be invalid in prefix scan, aligning with PRs #31063 and #31746.
September 2025 monthly summary for tensorflow/tensorflow: Delivered a critical correctness fix in ScatterDeterminismExpander addressing zero-index handling in scatter_set operations and prefix scan, preventing incorrect results and false matches caused by zero padding. Updated mask initialization and added tests to cover zero-padding edge cases. Related commits fixed shifting issues and updated the padded index value to be invalid in prefix scan, aligning with PRs #31063 and #31746.
July 2025 highlights across two major repos. AI-Hypercomputer/maxtext delivered a new Fp8Einsum dtype management wrapper (_Fp8EinsumWrapper) to enforce correct right-hand side casting to the computation dtype and to cast the left-hand side within the FP8 quantization workflow, improving numerical stability and data-type control in FP8 einsum paths. In TensorFlow, implemented a CuDNN multi-threaded compilation optimization by introducing a shared cuDNN handle reused across threads, replacing LocalCuDnnHandle, reducing compilation overhead and preventing hangs on Blackwell GPUs. Additionally, fixed CUDA platform registration to stabilize GPU AOT tests, ensuring reliable test discovery and execution. These changes collectively improve performance, reliability, and correctness for FP8 workflows and GPU-accelerated operations.
July 2025 highlights across two major repos. AI-Hypercomputer/maxtext delivered a new Fp8Einsum dtype management wrapper (_Fp8EinsumWrapper) to enforce correct right-hand side casting to the computation dtype and to cast the left-hand side within the FP8 quantization workflow, improving numerical stability and data-type control in FP8 einsum paths. In TensorFlow, implemented a CuDNN multi-threaded compilation optimization by introducing a shared cuDNN handle reused across threads, replacing LocalCuDnnHandle, reducing compilation overhead and preventing hangs on Blackwell GPUs. Additionally, fixed CUDA platform registration to stabilize GPU AOT tests, ensuring reliable test discovery and execution. These changes collectively improve performance, reliability, and correctness for FP8 workflows and GPU-accelerated operations.
June 2025 monthly summary for AI-Hypercomputer/maxtext: Delivered FP8 Quantization Refinement in the MaxText library, shifting FP8 computations from a fake-quantization approach to a direct quantization path. This change improved precision and computational efficiency in FP8 workflows, enabling more reliable quantized inference and better utilization of hardware accelerators. The work strengthens the MaxText FP8 ecosystem and lays groundwork for further performance optimizations.
June 2025 monthly summary for AI-Hypercomputer/maxtext: Delivered FP8 Quantization Refinement in the MaxText library, shifting FP8 computations from a fake-quantization approach to a direct quantization path. This change improved precision and computational efficiency in FP8 workflows, enabling more reliable quantized inference and better utilization of hardware accelerators. The work strengthens the MaxText FP8 ecosystem and lays groundwork for further performance optimizations.
April 2025 monthly summary for AI-Hypercomputer/maxtext: Focused on correctness and reliability of FP8 computations. Delivered a critical bug fix by switching the FP8 dot product path from fake quantization to direct quantization, correcting the quantization path and improving FP8 computation accuracy. The change is captured in commit 6775a40de9c757e94dab1330a087a10666753e4c. Impact: more reliable FP8 math for AI workloads and reduced downstream quantization errors. This work strengthens the foundation for future performance optimizations in the maxtext kernel.
April 2025 monthly summary for AI-Hypercomputer/maxtext: Focused on correctness and reliability of FP8 computations. Delivered a critical bug fix by switching the FP8 dot product path from fake quantization to direct quantization, correcting the quantization path and improving FP8 computation accuracy. The change is captured in commit 6775a40de9c757e94dab1330a087a10666753e4c. Impact: more reliable FP8 math for AI workloads and reduced downstream quantization errors. This work strengthens the foundation for future performance optimizations in the maxtext kernel.
March 2025: Delivered cross-memory-space support for EmitSort with IgnoreMemorySpace in ROCm/xla, expanded test coverage for multi-memory-space inputs, and fixed EmitSort validation after enabling NVLS and user buffer to improve reliability and correctness of multi-memory-space sorts on the same device. These changes reduce memory-space related errors and enable scenarios with inputs from different memory spaces, delivering business value through more robust device-side sorting and broader hardware compatibility.
March 2025: Delivered cross-memory-space support for EmitSort with IgnoreMemorySpace in ROCm/xla, expanded test coverage for multi-memory-space inputs, and fixed EmitSort validation after enabling NVLS and user buffer to improve reliability and correctness of multi-memory-space sorts on the same device. These changes reduce memory-space related errors and enable scenarios with inputs from different memory spaces, delivering business value through more robust device-side sorting and broader hardware compatibility.
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