
Tom Natan engineered robust sharding and distributed compilation features across the openxla/xla and ROCm/tensorflow-upstream repositories, focusing on StableHLO and Shardy integration. He developed and optimized cross-dialect import/export pipelines, improved mesh deduplication, and enhanced round-trip correctness for distributed tensor operations. Using C++ and MLIR, Tom implemented selective conversion logic, serialization compatibility, and auto-partitioning defaults, addressing both performance and reliability. His work included targeted bug fixes for shape handling and thread safety, as well as API and build system refinements. These contributions enabled more reliable distributed training, streamlined cross-platform workflows, and reduced manual intervention in complex machine learning pipelines.

August 2025 performance and stability improvements across Intel-tensorflow/tensorflow, openxla/xla, and ROCm/tensorflow-upstream. Focused on business value by reducing runtime overhead, hardening round-trip correctness, and enabling flexible shard-map handling for StableHLO and related flows. Delivered targeted improvements to dedup mesh processing, stabilized round-trip export paths, and expanded shard-map export options, with explicit TSAN race mitigations to improve reliability in parallel passes.
August 2025 performance and stability improvements across Intel-tensorflow/tensorflow, openxla/xla, and ROCm/tensorflow-upstream. Focused on business value by reducing runtime overhead, hardening round-trip correctness, and enabling flexible shard-map handling for StableHLO and related flows. Delivered targeted improvements to dedup mesh processing, stabilized round-trip export paths, and expanded shard-map export options, with explicit TSAN race mitigations to improve reliability in parallel passes.
2025-07 Monthly Summary: Focused delivery across Shardy/StableHLO integration, auto-sharding defaults, serialization compatibility, and cross-dialect reliability. The work enabled more robust import/export pipelines, safer LocalToGlobalShape handling, and smoother cross-repo interoperability, accelerating release readiness and reducing integration risk.
2025-07 Monthly Summary: Focused delivery across Shardy/StableHLO integration, auto-sharding defaults, serialization compatibility, and cross-dialect reliability. The work enabled more robust import/export pipelines, safer LocalToGlobalShape handling, and smoother cross-repo interoperability, accelerating release readiness and reducing integration risk.
June 2025: Delivered cross-repo SDY/StableHLO integration and sharding optimizations across ROCm/tensorflow-upstream, ROCm/xla, and openxla/xla, along with stability and shape-handling improvements. The work enhances distributed training performance, reliability, and graph compatibility, while reducing manual intervention in mesh/axis management.
June 2025: Delivered cross-repo SDY/StableHLO integration and sharding optimizations across ROCm/tensorflow-upstream, ROCm/xla, and openxla/xla, along with stability and shape-handling improvements. The work enhances distributed training performance, reliability, and graph compatibility, while reducing manual intervention in mesh/axis management.
May 2025 monthly summary: Focused on stabilizing and expanding SDY/Shardy integration across multiple XLA backends and dialects, improving cross-architecture reliability (X64), and tightening build/CI hygiene. Delivered concrete correctness and performance improvements in propagation and sharding, advanced shape handling and AWS-like reductions, and prepared round-trip/export paths for future release cycles. Business impact includes more robust distributed training/compute pipelines, easier maintenance, and faster enablement of cross-platform support.
May 2025 monthly summary: Focused on stabilizing and expanding SDY/Shardy integration across multiple XLA backends and dialects, improving cross-architecture reliability (X64), and tightening build/CI hygiene. Delivered concrete correctness and performance improvements in propagation and sharding, advanced shape handling and AWS-like reductions, and prepared round-trip/export paths for future release cycles. Business impact includes more robust distributed training/compute pipelines, easier maintenance, and faster enablement of cross-platform support.
April 2025 performance summary: Delivered extensive Shardy integration and sharding lifecycle improvements across ROCm/xla, ROCm/tensorflow-upstream, jax-ml/jax, and ROCm/jax, delivering measurable business impact in compilation efficiency, correctness, and test reliability. Key accomplishments include implementing frontend attribute escaping improvements and API simplifications, end-to-end sharding lifecycle enhancements with improved gating and memory-management optimizations, stabilization of StableHLO tests during assembly format transitions, reduced redundant MLIR bytecode conversions in Shardy paths, and expanded GPU topology testing with new Shardy configurations. These changes reduce parsing and compilation errors, accelerate build/test cycles, and strengthen cross-repo Shardy support for scalable workloads across CPU/GPU targets.
April 2025 performance summary: Delivered extensive Shardy integration and sharding lifecycle improvements across ROCm/xla, ROCm/tensorflow-upstream, jax-ml/jax, and ROCm/jax, delivering measurable business impact in compilation efficiency, correctness, and test reliability. Key accomplishments include implementing frontend attribute escaping improvements and API simplifications, end-to-end sharding lifecycle enhancements with improved gating and memory-management optimizations, stabilization of StableHLO tests during assembly format transitions, reduced redundant MLIR bytecode conversions in Shardy paths, and expanded GPU topology testing with new Shardy configurations. These changes reduce parsing and compilation errors, accelerate build/test cycles, and strengthen cross-repo Shardy support for scalable workloads across CPU/GPU targets.
Monthly work summary focusing on key accomplishments for 2025-03. Key achievements (top 3-5): - ROCm/xla: Enabled MHLO dialect in the build and added a CopyOp sharding rule to support SHARDY/StableHLO conversion, enabling continued MHLO-to-CopyOp compatibility across the SHARDY path. (Commits: 7aabfd0d9d63419eddf80b8180fb1d27edb90a92; 5adcd7913acb2504436dbb04aad8988213c17518) - ROCm/xla: Reworked StableHLO to Shardy conversion to aid the GSPMD partitioner by rewriting collectives to mhlo::CopyOp, refactoring rewriting logic, and converting uninlineable func.call usages to sdy.named_computation (Commits: 348509c2b4b44dbcbdfa26a8c601b0ed2dac6047; 8e445a94142639aae2630e40c8cd945949ee7f55; f05219f24c8a813c5b2a2a6b39365bf5bf751dfd) - jax-ml/jax: Stabilized Shardy test coverage by unskipping tests related to Shardy functionality; underlying issues resolved (Commits: c098b363fb032bbf812eceef679141e5261380bd; 8bbd738df1d77b998241b36a110eb5545cf4d2f3) - ROCm/jax: Improved test stability by restoring ComputeOffload test in memories_test and removing conditional skip logic, increasing reliability and coverage (Commit: 21ce20ac8b42d4f73e06202e30fcfd75e279fe33) Overall impact and accomplishments: - Strengthened stability and coverage of Shardy-related features across ROCm/xla, jax-ml/jax, and ROCm/jax, reducing regression risk and enabling more reliable experimentation and deployment. - Improved compatibility between StableHLO and SHARDY, enabling more scalable partitioning workflows (GSPMD), and better handling of non-inlineable calls. Technologies/skills demonstrated: - MLIR dialects (MHLO), SHARDY, StableHLO, mhlo::CopyOp, sdy.named_computation - Code refactoring and architecture awareness for rewriting logic - Test stabilization and coverage improvement, including unskipping and reliability hardening Business value: - Reduced risk in cross-repo SHARDY adoption, faster validation of MHLO-related paths, and more reliable end-to-end partitioning for production workloads.
Monthly work summary focusing on key accomplishments for 2025-03. Key achievements (top 3-5): - ROCm/xla: Enabled MHLO dialect in the build and added a CopyOp sharding rule to support SHARDY/StableHLO conversion, enabling continued MHLO-to-CopyOp compatibility across the SHARDY path. (Commits: 7aabfd0d9d63419eddf80b8180fb1d27edb90a92; 5adcd7913acb2504436dbb04aad8988213c17518) - ROCm/xla: Reworked StableHLO to Shardy conversion to aid the GSPMD partitioner by rewriting collectives to mhlo::CopyOp, refactoring rewriting logic, and converting uninlineable func.call usages to sdy.named_computation (Commits: 348509c2b4b44dbcbdfa26a8c601b0ed2dac6047; 8e445a94142639aae2630e40c8cd945949ee7f55; f05219f24c8a813c5b2a2a6b39365bf5bf751dfd) - jax-ml/jax: Stabilized Shardy test coverage by unskipping tests related to Shardy functionality; underlying issues resolved (Commits: c098b363fb032bbf812eceef679141e5261380bd; 8bbd738df1d77b998241b36a110eb5545cf4d2f3) - ROCm/jax: Improved test stability by restoring ComputeOffload test in memories_test and removing conditional skip logic, increasing reliability and coverage (Commit: 21ce20ac8b42d4f73e06202e30fcfd75e279fe33) Overall impact and accomplishments: - Strengthened stability and coverage of Shardy-related features across ROCm/xla, jax-ml/jax, and ROCm/jax, reducing regression risk and enabling more reliable experimentation and deployment. - Improved compatibility between StableHLO and SHARDY, enabling more scalable partitioning workflows (GSPMD), and better handling of non-inlineable calls. Technologies/skills demonstrated: - MLIR dialects (MHLO), SHARDY, StableHLO, mhlo::CopyOp, sdy.named_computation - Code refactoring and architecture awareness for rewriting logic - Test stabilization and coverage improvement, including unskipping and reliability hardening Business value: - Reduced risk in cross-repo SHARDY adoption, faster validation of MHLO-related paths, and more reliable end-to-end partitioning for production workloads.
February 2025 focused on strengthening stability, correctness, and performance in ROCm/xla. Deliveries span critical StableHLO to HLO conversion improvements, platform robustness for Android, and optimization of string handling in hot paths, contributing to more reliable deployments and better runtime characteristics.
February 2025 focused on strengthening stability, correctness, and performance in ROCm/xla. Deliveries span critical StableHLO to HLO conversion improvements, platform robustness for Android, and optimization of string handling in hot paths, contributing to more reliable deployments and better runtime characteristics.
Month: 2025-01 — ROCm/xla: concise performance-focused update across the canonicalizer path for SHARDED_DIALECT_TO_STABLEHLO conversion. Key feature delivered: a targeted performance optimization in the Canonicalizer Pass by disabling expensive optimizations (constant folding and CSE for constants) to reduce runtime in the conversion pipeline, complemented by an updated GreedyRewriteConfig. No major bugs fixed this month; the delivered changes prioritize stability and trackable performance gains for the next QA cycle. Overall impact: improved conversion throughput and reduced resource usage, enabling faster iteration and deployment of subsequent optimizations. Technologies/skills demonstrated: C++, MLIR/LLVM-based passes, GreedyRewriteConfig, canonicalizer tuning, ROCm/xla ecosystem, performance profiling and careful code-review discipline.
Month: 2025-01 — ROCm/xla: concise performance-focused update across the canonicalizer path for SHARDED_DIALECT_TO_STABLEHLO conversion. Key feature delivered: a targeted performance optimization in the Canonicalizer Pass by disabling expensive optimizations (constant folding and CSE for constants) to reduce runtime in the conversion pipeline, complemented by an updated GreedyRewriteConfig. No major bugs fixed this month; the delivered changes prioritize stability and trackable performance gains for the next QA cycle. Overall impact: improved conversion throughput and reduced resource usage, enabling faster iteration and deployment of subsequent optimizations. Technologies/skills demonstrated: C++, MLIR/LLVM-based passes, GreedyRewriteConfig, canonicalizer tuning, ROCm/xla ecosystem, performance profiling and careful code-review discipline.
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