erlang/otp
Nov 2024 – May 2025
3 Months active
Languages Used
Erlang
Technical Skills
Bug FixingCode AnalysisCode OptimizationCode RefactoringCompiler DevelopmentStatic Analysis
Frej Drejhammar
PROFILE
Frej Drejhammar
Worked on enhancing the erlang/otp compiler by improving alias analysis and patch merging logic to increase reliability and correctness. Focused on handling repeated tuple element extraction and function call arguments, introducing forced aliasing and refactoring to distinguish between Phi-instruction and general call arguments. Addressed patch merging for nested structures, preventing unsafe destructive updates and reducing crash risk. Implemented aliasing-aware handling for comparison built-ins, ensuring safe optimizations based on type information. Utilized Erlang and applied skills in static analysis, code optimization, and debugging. Added comprehensive tests and improved debugging output, contributing to safer, more maintainable compiler development and optimization workflows.
Overall Statistics
Feature vs Bugs
25%Features
Repository Contributions
10Total
Bugs
3
Commits
10
Features
1
Lines of code
753
Activity Months3
Your Network
180 peopleShared Repositories
180
Work History
May 2025
2 Commits
May 1, 2025Month: 2025-05 — Summary of work on erlang/otp focused on correctness and reliability of the compiler alias analysis for comparison built-ins (bifs). Implemented aliasing-aware handling for bifs, preventing visibility of destructive updates to internal term elements and avoiding unnecessary aliasing when type information indicates the bif will be reduced to a simple tag test. Added improved debugging printout for alias analysis to facilitate quicker troubleshooting. This work reduces subtle correctness risks in compiler optimizations, improves maintenance of aliasing logic, and contributes to more stable builds.
2 Commits
May 1, 2025Month: 2025-05 — Summary of work on erlang/otp focused on correctness and reliability of the compiler alias analysis for comparison built-ins (bifs). Implemented aliasing-aware handling for bifs, preventing visibility of destructive updates to internal term elements and avoiding unnecessary aliasing when type information indicates the bif will be reduced to a simple tag test. Added improved debugging printout for alias analysis to facilitate quicker troubleshooting. This work reduces subtle correctness risks in compiler optimizations, improves maintenance of aliasing logic, and contributes to more stable builds.
May 2025
January 2025
2 Commits
Jan 1, 2025January 2025 monthly summary focused on strengthening the Erlang/OTP compiler’s alias analysis for repeated arguments in function calls. Executed a targeted bug fix that involved renaming an existing Phi-instruction related function, introducing a new handler to process repeated call arguments, and refactoring to distinguish Phi-instruction arguments from general call arguments to improve alias detection accuracy. Added a dedicated test (duplicated_args/1) to validate repeated-argument scenarios, and consolidated changes into two commits that implement the fix. Business value centers on correctness of optimization and reliability of the compiler.
January 2025
2 Commits
Jan 1, 2025January 2025 monthly summary focused on strengthening the Erlang/OTP compiler’s alias analysis for repeated arguments in function calls. Executed a targeted bug fix that involved renaming an existing Phi-instruction related function, introducing a new handler to process repeated call arguments, and refactoring to distinguish Phi-instruction arguments from general call arguments to improve alias detection accuracy. Added a dedicated test (duplicated_args/1) to validate repeated-argument scenarios, and consolidated changes into two commits that implement the fix. Business value centers on correctness of optimization and reliability of the compiler.
November 2024
6 Commits • 1 Features
Nov 1, 2024In 2024-11, delivered key compiler reliability improvements in erlang/otp: enhanced alias analysis to correctly handle repeated tuple element extraction with forced aliasing to prevent unsafe destructive updates; fixed patch merging for nested structures and multiple updates to literals in patching and Phi-instructions; added comprehensive tests and merging helpers. These changes reduce crash risk, preserve data integrity during in-place updates, and lay groundwork for safer optimizations.
6 Commits • 1 Features
Nov 1, 2024In 2024-11, delivered key compiler reliability improvements in erlang/otp: enhanced alias analysis to correctly handle repeated tuple element extraction with forced aliasing to prevent unsafe destructive updates; fixed patch merging for nested structures and multiple updates to literals in patching and Phi-instructions; added comprehensive tests and merging helpers. These changes reduce crash risk, preserve data integrity during in-place updates, and lay groundwork for safer optimizations.
November 2024
Activity
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Quality Metrics
Correctness92.0%
Maintainability82.0%
Architecture82.0%
Performance70.0%
AI Usage20.0%
Skills & Technologies
Programming Languages
Erlang
Technical Skills
Alias AnalysisBug FixingCode AnalysisCode OptimizationCode RefactoringCompiler DevelopmentDebuggingStatic Analysis
Repositories Contributed To
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