google/heir
Nov 2024 – Sep 2025
10 Months active
Languages Used
C++TableGenMLIRPythonStarlarkShellMarkdownBazel
Technical Skills
Compiler DevelopmentData Flow AnalysisMLIRStatic AnalysisC++Code Transformation
Alexander Viand
PROFILE
Alexander Viand
Alexander Viand developed core compiler infrastructure and secure computation features for the google/heir repository, focusing on homomorphic encryption and MLIR-based transformations. He engineered passes for secretness annotation, type inference, and dialect conversion, enabling explicit tracking of sensitive data and supporting compliance requirements. Using C++, Python, and MLIR, Alexander refactored the frontend for modularity, expanded tensor and arithmetic support, and improved backend reliability with OpenFHE integration. His work included build system enhancements, robust debugging tools, and test coverage expansion. The depth of his contributions advanced both the flexibility and security of the compilation pipeline, supporting scalable, production-ready cryptographic workflows.
Overall Statistics
Feature vs Bugs
88%Features
Repository Contributions
38Total
Bugs
4
Commits
38
Features
28
Lines of code
14,700
Activity Months10
Your Network
2019 people
Work History
September 2025
1 Commits • 1 Features
Sep 1, 2025September 2025 monthly summary for google/heir focused on dependency upgrades and build cleanup to improve stability and prepare for future features.
1 Commits • 1 Features
Sep 1, 2025September 2025 monthly summary for google/heir focused on dependency upgrades and build cleanup to improve stability and prepare for future features.
September 2025
July 2025
8 Commits • 6 Features
Jul 1, 2025July 2025 – google/heir: Delivered a set of high-impact backend and MLIR enhancements, focusing on reliability and performance. Key features include: (1) OpenFHE backend build and runtime improvements with include_dirs fixes and OpenMP enablement, plus GIL release for Python bindings to boost parallelism (commits c390d345def1ba7015ee3e737bbd678c94c70aab; 169034b7e70a1ee2a70f99152991117759aaec3f); (2) CKKS lowering for arith.negf implemented as lowering to ckks.negate in the Secret dialect with updated tests (de9bab2e730cc77c098abd6fe1aa0914c001179c); (3) Python/MLIR frontend and tooling enhancements, including consolidated dependencies, pyink formatter, MLIR from strings, and --emit-function-info (f8815fd82f10f41397cab3950bbc820a4aa06526); (4) Math_ext dialect and polynomial lowering enhancements, enabling sign operations and poly-approx lowering for arith.cmpi with compatibility improvements (15757ce92f718fac3dd44fb59e2d6f5a5f14a84f); (5) Stabilization of tests by aligning global variables to prevent segfaults in memrefCopy (794aee2de55fdea6c7782276a7cacf3ce7457114).
July 2025
8 Commits • 6 Features
Jul 1, 2025July 2025 – google/heir: Delivered a set of high-impact backend and MLIR enhancements, focusing on reliability and performance. Key features include: (1) OpenFHE backend build and runtime improvements with include_dirs fixes and OpenMP enablement, plus GIL release for Python bindings to boost parallelism (commits c390d345def1ba7015ee3e737bbd678c94c70aab; 169034b7e70a1ee2a70f99152991117759aaec3f); (2) CKKS lowering for arith.negf implemented as lowering to ckks.negate in the Secret dialect with updated tests (de9bab2e730cc77c098abd6fe1aa0914c001179c); (3) Python/MLIR frontend and tooling enhancements, including consolidated dependencies, pyink formatter, MLIR from strings, and --emit-function-info (f8815fd82f10f41397cab3950bbc820a4aa06526); (4) Math_ext dialect and polynomial lowering enhancements, enabling sign operations and poly-approx lowering for arith.cmpi with compatibility improvements (15757ce92f718fac3dd44fb59e2d6f5a5f14a84f); (5) Stabilization of tests by aligning global variables to prevent segfaults in memrefCopy (794aee2de55fdea6c7782276a7cacf3ce7457114).
June 2025
5 Commits • 4 Features
Jun 1, 2025June 2025 monthly summary for google/heir: Delivered core MLIR enhancements, developer experience improvements, and emitter tooling for CKKS and OpenFHE. Focused on business value, performance modeling, and production readiness with scalable architecture and clear documentation of changes.
5 Commits • 4 Features
Jun 1, 2025June 2025 monthly summary for google/heir: Delivered core MLIR enhancements, developer experience improvements, and emitter tooling for CKKS and OpenFHE. Focused on business value, performance modeling, and production readiness with scalable architecture and clear documentation of changes.
June 2025
May 2025
3 Commits • 2 Features
May 1, 2025Month: 2025-05 – Focused on delivering core frontend tensor capabilities for HEIR and strengthening backend type handling. Delivered tensor type support in the HEIR frontend, updated build files, MLIR type annotations, added shape inference passes, and new tests for tensor operations. Expanded test coverage and refactoring of HEIR frontend examples to well-scoped functions. Fixed critical type inference issues in the Numba backend to improve runtime correctness and reliability.
May 2025
3 Commits • 2 Features
May 1, 2025Month: 2025-05 – Focused on delivering core frontend tensor capabilities for HEIR and strengthening backend type handling. Delivered tensor type support in the HEIR frontend, updated build files, MLIR type annotations, added shape inference passes, and new tests for tensor operations. Expanded test coverage and refactoring of HEIR frontend examples to well-scoped functions. Fixed critical type inference issues in the Numba backend to improve runtime correctness and reliability.
April 2025
1 Commits • 1 Features
Apr 1, 2025April 2025: Implemented development-time OpenFHE discovery and configuration in google/heir to prioritize a bazel-built OpenFHE when not installed. This change adds development_openfhe_config to locate and configure OpenFHE from the repository's build artifacts, and updates environment variable handling and test configurations to support the discovery mechanism. The update improves build reproducibility, reduces dependency fragility, and accelerates development and testing cycles.
1 Commits • 1 Features
Apr 1, 2025April 2025: Implemented development-time OpenFHE discovery and configuration in google/heir to prioritize a bazel-built OpenFHE when not installed. This change adds development_openfhe_config to locate and configure OpenFHE from the repository's build artifacts, and updates environment variable handling and test configurations to support the discovery mechanism. The update improves build reproducibility, reduces dependency fragility, and accelerates development and testing cycles.
April 2025
March 2025
4 Commits • 3 Features
Mar 1, 2025Monthly summary for 2025-03 focusing on google/heir delivery. Key features delivered include cross-dialect LWE reinterpretation adjustments, mixed bitwidth arithmetic support in the Frontend/MLIR emitter, and a new HE-friendly arith.select rewrite pass. These changes improve interoperability, API consistency, and HE compatibility across SecretToBGV and SecretToCKKS pipelines, with accompanying tests and type-system adjustments.
March 2025
4 Commits • 3 Features
Mar 1, 2025Monthly summary for 2025-03 focusing on google/heir delivery. Key features delivered include cross-dialect LWE reinterpretation adjustments, mixed bitwidth arithmetic support in the Frontend/MLIR emitter, and a new HE-friendly arith.select rewrite pass. These changes improve interoperability, API consistency, and HE compatibility across SecretToBGV and SecretToCKKS pipelines, with accompanying tests and type-system adjustments.
February 2025
4 Commits • 2 Features
Feb 1, 2025February 2025 monthly summary for google/heir. Focused on frontend refactor, type inference, bug fix in Numba migration, and ModArith constant handling enhancements. Delivered improvements to reliability, Python 3.11 compatibility, and dialect parsing with dense constants.
4 Commits • 2 Features
Feb 1, 2025February 2025 monthly summary for google/heir. Focused on frontend refactor, type inference, bug fix in Numba migration, and ModArith constant handling enhancements. Delivered improvements to reliability, Python 3.11 compatibility, and dialect parsing with dense constants.
February 2025
January 2025
4 Commits • 3 Features
Jan 1, 2025January 2025 focused on delivering modularity, debugging improvements, and cross-dialect flexibility in the google/heir repository. Key refinements include OpenFHE Emitter and Pipeline Modernization, enhanced secretness debugging, and broader ciphertext compatibility across dialects, collectively increasing developer velocity and enabling broader cryptographic experimentation.
January 2025
4 Commits • 3 Features
Jan 1, 2025January 2025 focused on delivering modularity, debugging improvements, and cross-dialect flexibility in the google/heir repository. Key refinements include OpenFHE Emitter and Pipeline Modernization, enhanced secretness debugging, and broader ciphertext compatibility across dialects, collectively increasing developer velocity and enabling broader cryptographic experimentation.
December 2024
7 Commits • 5 Features
Dec 1, 2024December 2024 for google/heir delivered broader secretization coverage, CKKS/RLWE experimentation enablement, pipeline improvements, and IR stability enhancements, coupled with enhanced debugging capabilities. The work reduces manual transformation effort, expands secure-computation experimentation, and improves reliability and observability across the mlir-to-secret-arithmetic stack. Key outcomes include a more general --secretize pass with documentation/testing updates, CKKS support in AddClientInterface integrated with the RLWE pipeline, the new --operation-balancer in the arithmetic pipeline, targeted IR stability fixes, and a debug mode that emits intermediate MLIR for troubleshooting.
7 Commits • 5 Features
Dec 1, 2024December 2024 for google/heir delivered broader secretization coverage, CKKS/RLWE experimentation enablement, pipeline improvements, and IR stability enhancements, coupled with enhanced debugging capabilities. The work reduces manual transformation effort, expands secure-computation experimentation, and improves reliability and observability across the mlir-to-secret-arithmetic stack. Key outcomes include a more general --secretize pass with documentation/testing updates, CKKS support in AddClientInterface integrated with the RLWE pipeline, the new --operation-balancer in the arithmetic pipeline, targeted IR stability fixes, and a debug mode that emits intermediate MLIR for troubleshooting.
December 2024
November 2024
1 Commits • 1 Features
Nov 1, 2024Month: 2024-11 — Focused on security-oriented compiler improvements in google/heir. Delivered Secretness Annotation Pass for MLIR IR to annotate secretness of SSA values using SecretnessAnalysis, enabling explicit tracking of secret data flow throughout the compilation pipeline and supporting security/compliance goals. Committed as: add `--annotate-secretness` pass (055793027e6a63063dfd00ab868fb45692ef45e9).
November 2024
1 Commits • 1 Features
Nov 1, 2024Month: 2024-11 — Focused on security-oriented compiler improvements in google/heir. Delivered Secretness Annotation Pass for MLIR IR to annotate secretness of SSA values using SecretnessAnalysis, enabling explicit tracking of secret data flow throughout the compilation pipeline and supporting security/compliance goals. Committed as: add `--annotate-secretness` pass (055793027e6a63063dfd00ab868fb45692ef45e9).
Activity
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Quality Metrics
Correctness89.6%
Maintainability87.2%
Architecture88.0%
Performance77.6%
AI Usage20.6%
Skills & Technologies
Programming Languages
BazelCC++MLIRMarkdownPythonShellStarlarkTableGen
Technical Skills
Backend DevelopmentBuild System ConfigurationBuild SystemsBuild Systems (Bazel)C ProgrammingC++Code GenerationCode RefactoringCode TransformationCompiler DevelopmentConfiguration ManagementData Flow AnalysisDebuggingDependency ManagementDeveloper Tooling
Repositories Contributed To
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