YosysHQ/yosys
Nov 2024 – Jun 2026
11 Months active
Languages Used
C++TextVerilogYosys ScriptPythontextYAMLYosys
Technical Skills
Code RefactoringCompiler DesignDigital DesignDigital Logic DesignHardware Description Language ParsingLibrary Parsing
Lofty
PROFILE
Lofty
Over 11 months, contributed to the YosysHQ/yosys repository by developing and refining digital synthesis features, focusing on analog and digital device support, timing model enhancements, and ABC tool integration. Leveraged C++, Verilog, and Python to implement new synthesis libraries, optimize timing specifications, and improve compatibility with AIGER and XAIGER flows. Delivered robust code refactoring, enhanced test automation, and streamlined logging to improve maintainability and synthesis reliability. Integrated ABC standard-cell mappings and modularized synthesis passes, enabling more predictable and maintainable flows. Emphasized code quality, documentation governance, and cross-module collaboration to support evolving hardware design and verification requirements.
Overall Statistics
Feature vs Bugs
100%Features
Repository Contributions
51Total
Bugs
0
Commits
51
Features
20
Lines of code
600,216
Activity Months11
Your Network
87 peopleWork History
June 2026
2 Commits • 1 Features
Jun 1, 2026June 2026 monthly summary for YosysHQ/yosys. Delivered ABC Integration Enhancements for XAIGER Parsing and Yosys Synthesis Flow, focusing on improved import of ABC standard-cell mappings into the AIGER reader for XAIGER parsing and the introduction of a dedicated pass to reintegrate ABC9 operations into the Yosys synthesis flow. This work increases modularity, maintainability, and reliability of the synthesis pipeline, enabling easier future ABC updates and more predictable results in downstream flows.
2 Commits • 1 Features
Jun 1, 2026June 2026 monthly summary for YosysHQ/yosys. Delivered ABC Integration Enhancements for XAIGER Parsing and Yosys Synthesis Flow, focusing on improved import of ABC standard-cell mappings into the AIGER reader for XAIGER parsing and the introduction of a dedicated pass to reintegrate ABC9 operations into the Yosys synthesis flow. This work increases modularity, maintainability, and reliability of the synthesis pipeline, enabling easier future ABC updates and more predictable results in downstream flows.
June 2026
May 2026
1 Commits • 1 Features
May 1, 2026May 2026: Implemented a new AIGER support feature in Yosys by adding the aiger2_zbuf constant identifier to the constids list and updating the abc9_ops.cc logic to assign a boolean attribute in the design module. This enhances compatibility with AIGER-based flows and enables more accurate synthesis and attribute-driven optimizations. The change is tracked in commit de1dd3b1c5ac6f95323a56a6c456632d5623320a. No major bugs were recorded this month; effort focused on delivering the feature and improving code quality. Business impact: smoother design-to-synthesis path for AIGER designs, improved attribute handling, and reduced risk of misinterpretation in the synthesis pipeline.
May 2026
1 Commits • 1 Features
May 1, 2026May 2026: Implemented a new AIGER support feature in Yosys by adding the aiger2_zbuf constant identifier to the constids list and updating the abc9_ops.cc logic to assign a boolean attribute in the design module. This enhances compatibility with AIGER-based flows and enables more accurate synthesis and attribute-driven optimizations. The change is tracked in commit de1dd3b1c5ac6f95323a56a6c456632d5623320a. No major bugs were recorded this month; effort focused on delivering the feature and improving code quality. Business impact: smoother design-to-synthesis path for AIGER designs, improved attribute handling, and reduced risk of misinterpretation in the synthesis pipeline.
April 2026
5 Commits • 2 Features
Apr 1, 2026April 2026: Focused on robustness, readability, and integration within the Yosys XAIGER and abc_new workflows. Delivered code-quality improvements to the XAIGER writer/frontend and integrated enhancements for abc_new mapping, enabling safer defaults and configurable passes. Strengthened diagnostic capabilities for map-file processing and improved maintainability of the frontend/writer to facilitate faster issue resolution and future feature work.
5 Commits • 2 Features
Apr 1, 2026April 2026: Focused on robustness, readability, and integration within the Yosys XAIGER and abc_new workflows. Delivered code-quality improvements to the XAIGER writer/frontend and integrated enhancements for abc_new mapping, enabling safer defaults and configurable passes. Strengthened diagnostic capabilities for map-file processing and improved maintainability of the frontend/writer to facilitate faster issue resolution and future feature work.
April 2026
March 2026
16 Commits • 3 Features
Mar 1, 2026Month: 2026-03 – This month focused on delivering improved ABC-driven synthesis workflows for Yosys, tightening device-specific timing support, and enhancing code hygiene to improve maintainability across the repository. Key outcomes include configurable and higher-quality synthesis with ABC tool integration, updated timing for target devices (notably T40LP), and standardized module naming across Analog Devices/Xilinx conventions, driving reliable builds and faster iteration for customers.
March 2026
16 Commits • 3 Features
Mar 1, 2026Month: 2026-03 – This month focused on delivering improved ABC-driven synthesis workflows for Yosys, tightening device-specific timing support, and enhancing code hygiene to improve maintainability across the repository. Key outcomes include configurable and higher-quality synthesis with ABC tool integration, updated timing for target devices (notably T40LP), and standardized module naming across Analog Devices/Xilinx conventions, driving reliable builds and faster iteration for customers.
January 2026
2 Commits • 1 Features
Jan 1, 2026Monthly Summary — 2026-01 Key outcomes: - Timing Specifications Enhancement for T16FFC and T40LP Modules: Improved timing specs in the Analog Devices library, increasing signal timing accuracy and processing performance across critical modules. Major bugs fixed: - None reported this month. Overall impact and accomplishments: - The timing enhancements deliver higher fidelity simulations and more robust hardware integration, enabling downstream designers to meet performance targets with reduced risk. Two focused commits were applied to YosysHQ/yosys, establishing a standard timing profile for T16FFC and T40LP, and reducing iteration cycles for design validation. Technologies/skills demonstrated: - Timing analysis and library integration for Analog Devices components - Version control and commit hygiene (Git) across multiple modules - Cross-module collaboration and performance optimization for hardware libraries - Verification planning and impact assessment for timing-related changes
2 Commits • 1 Features
Jan 1, 2026Monthly Summary — 2026-01 Key outcomes: - Timing Specifications Enhancement for T16FFC and T40LP Modules: Improved timing specs in the Analog Devices library, increasing signal timing accuracy and processing performance across critical modules. Major bugs fixed: - None reported this month. Overall impact and accomplishments: - The timing enhancements deliver higher fidelity simulations and more robust hardware integration, enabling downstream designers to meet performance targets with reduced risk. Two focused commits were applied to YosysHQ/yosys, establishing a standard timing profile for T16FFC and T40LP, and reducing iteration cycles for design validation. Technologies/skills demonstrated: - Timing analysis and library integration for Analog Devices components - Version control and commit hygiene (Git) across multiple modules - Cross-module collaboration and performance optimization for hardware libraries - Verification planning and impact assessment for timing-related changes
January 2026
November 2025
1 Commits • 1 Features
Nov 1, 2025November 2025 performance summary for YosysHQ/yosys focused on analog timing accuracy and test reliability. Implemented Analog Devices Timing Model Enhancements by updating timing models for flip-flops and memory components in the analog devices library, paired with test suite hygiene improvements. This work included removing outdated test files and adjusting existing tests to reflect the new timing parameters, ensuring CI stability and alignment with vendor specs. Commit cd60dd49120b407f2650d9d1dbf2c5b2a6f787ef captured the changes.
November 2025
1 Commits • 1 Features
Nov 1, 2025November 2025 performance summary for YosysHQ/yosys focused on analog timing accuracy and test reliability. Implemented Analog Devices Timing Model Enhancements by updating timing models for flip-flops and memory components in the analog devices library, paired with test suite hygiene improvements. This work included removing outdated test files and adjusting existing tests to reflect the new timing parameters, ensuring CI stability and alignment with vendor specs. Commit cd60dd49120b407f2650d9d1dbf2c5b2a6f787ef captured the changes.
October 2025
13 Commits • 4 Features
Oct 1, 2025October 2025 monthly summary for YosysHQ/yosys: Delivered key features and performance improvements in the analog devices integration. Implemented the RBBDSP DSP module with updated DSP mapping and synthesis support; enhanced timing models for analog devices and prepared for T40LP timing analysis; expanded LUTRAM/RAM modules for better performance and resource modeling; performed comprehensive code cleanup and refactor to improve maintainability and synthesis reliability. These efforts increase hardware efficiency, simulation fidelity, and overall system reliability, enabling faster time-to-market for DSP-enabled devices and more accurate resource planning.
13 Commits • 4 Features
Oct 1, 2025October 2025 monthly summary for YosysHQ/yosys: Delivered key features and performance improvements in the analog devices integration. Implemented the RBBDSP DSP module with updated DSP mapping and synthesis support; enhanced timing models for analog devices and prepared for T40LP timing analysis; expanded LUTRAM/RAM modules for better performance and resource modeling; performed comprehensive code cleanup and refactor to improve maintainability and synthesis reliability. These efforts increase hardware efficiency, simulation fidelity, and overall system reliability, enabling faster time-to-market for DSP-enabled devices and more accurate resource planning.
October 2025
September 2025
6 Commits • 3 Features
Sep 1, 2025September 2025 monthly summary for YosysHQ/yosys focusing on feature delivery, refactor, and verification enhancements. Key outcomes include a new Analog Devices synthesis library, a major Digital Design Core refactor for clarity and EDIF optimization, and a comprehensive test suite to improve design verification. These efforts collectively tightened design cycles, improved synthesis quality, and strengthened maintainability across the repository.
September 2025
6 Commits • 3 Features
Sep 1, 2025September 2025 monthly summary for YosysHQ/yosys focusing on feature delivery, refactor, and verification enhancements. Key outcomes include a new Analog Devices synthesis library, a major Digital Design Core refactor for clarity and EDIF optimization, and a comprehensive test suite to improve design verification. These efforts collectively tightened design cycles, improved synthesis quality, and strengthened maintainability across the repository.
May 2025
2 Commits • 2 Features
May 1, 2025May 2025 monthly summary for repository YosysHQ/yosys: Focused on feature delivery around ABC integration and documentation governance. Key achievements include Genlib support in the abc_new pass with reading genlib files and using as a cell library description, validation to prevent -dont_use with genlib, and updates to abc9_exe help messaging. Documentation ownership for ABC docs updated to include the author as a reviewer for the relevant documentation. This period emphasized business value through enhanced synthesis configurability, reliability, and clearer governance of ABC documentation.
2 Commits • 2 Features
May 1, 2025May 2025 monthly summary for repository YosysHQ/yosys: Focused on feature delivery around ABC integration and documentation governance. Key achievements include Genlib support in the abc_new pass with reading genlib files and using as a cell library description, validation to prevent -dont_use with genlib, and updates to abc9_exe help messaging. Documentation ownership for ABC docs updated to include the author as a reviewer for the relevant documentation. This period emphasized business value through enhanced synthesis configurability, reliability, and clearer governance of ABC documentation.
May 2025
December 2024
1 Commits • 1 Features
Dec 1, 2024December 2024 monthly summary for YosysHQ/yosys focusing on reducing log noise during cell parsing and inference through targeted log verbosity optimization. No explicit bug fixes this period; rather, the effort centers on improving log signal quality to accelerate issue triage and maintenance.
December 2024
1 Commits • 1 Features
Dec 1, 2024December 2024 monthly summary for YosysHQ/yosys focusing on reducing log noise during cell parsing and inference through targeted log verbosity optimization. No explicit bug fixes this period; rather, the effort centers on improving log signal quality to accelerate issue triage and maintenance.
November 2024
2 Commits • 1 Features
Nov 1, 2024Month: 2024-11 — Delivered targeted improvements to DFF library mapping and Liberty parsing in Yosys. Implemented enable pin inference for D-type flip-flops within dfflibmap and expanded supported DFF configurations. Refactored Liberty expression handling by introducing LibertyExpression and centralizing parsing in libparse to support complex cell attribute expressions. These changes improve synthesis accuracy, library compatibility, and reduce manual configuration for users. Technologies/skills demonstrated include Liberty parsing, libparse refactor, DFF library mapping, and commit-level traceability.
2 Commits • 1 Features
Nov 1, 2024Month: 2024-11 — Delivered targeted improvements to DFF library mapping and Liberty parsing in Yosys. Implemented enable pin inference for D-type flip-flops within dfflibmap and expanded supported DFF configurations. Refactored Liberty expression handling by introducing LibertyExpression and centralizing parsing in libparse to support complex cell attribute expressions. These changes improve synthesis accuracy, library compatibility, and reduce manual configuration for users. Technologies/skills demonstrated include Liberty parsing, libparse refactor, DFF library mapping, and commit-level traceability.
November 2024
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Quality Metrics
Correctness91.8%
Maintainability89.4%
Architecture89.8%
Performance87.8%
AI Usage23.6%
Skills & Technologies
Programming Languages
C++PythonTextVerilogYAMLYosysYosys Scripttext
Technical Skills
C++C++ developmentC++ programmingCode RefactoringCommand-line Interface (CLI) DevelopmentCompiler DesignCompiler DevelopmentContinuous IntegrationDigital DesignDigital Design Automation (EDA)Digital Logic DesignDigital designDocumentation ManagementFPGA designFPGA development
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