Irwin D'souza
JIT Compiler Developer at IBM Canada Ltd.
Old Toronto, Ontario, Canada
Summary
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Rockstar🎓
Top SchoolIrwin D'souza is a Staff Engineer and JIT compiler specialist with nine years of experience building high-performance VM tooling, currently contributing to Qualcomm after a long tenure at IBM where he was an OpenJ9 and OMR committer. He architects and implements Ahead-Of-Time and dynamic compilation features that measurably improved startup and throughput—driving a 15% AOT throughput gain and enabling 2x faster OpenLiberty startup in dev mode. Irwin led technical debt reduction, linting and formatting initiatives, owned runtime instrumentation and memory frameworks, and fixed elusive, non-deterministic compiler bugs via core dump analysis. An active open-source maintainer on widely-used projects Eclipse OpenJ9 and OMR, he focuses on relocatable code, heuristic regions, and robust relocation records to reduce AOT load failures and support checkpoint/restore use cases. Based in Toronto with a BASc in Electrical & Computer Engineering from University of Toronto, he blends low-level systems expertise with practical tooling ownership and mentorship of junior engineers.
9 years of coding experience
1 year of employment as a software developer
Mary Ward Catholic Secondary SchoolBASc, Electrical Engineering, Computer Engineering, BASc, Electrical Engineering, Computer Engineering at University of Toronto
Stackoverflow
91reputation
1kreached
4answers
0questions
Github Skills (20)
c-language10
jvm10
java10
javas10
aot10
compile10
compiler-optimization10
compiler10
cprogramming-language10
x869
g8
garbage-collection8
garbage8
collector8
maven-compiler-plugin6
Programming languages (9)
Github contributions (5)
eclipse-omr/omr
Jul 2019 - Dec 2022
Eclipse OMR™ Cross platform components for building reliable, high performance language runtimes
Role in this project:
Back-end Developer
Back-end DeveloperContributions:248 reviews, 139 commits, 181 PRs in 3 years 5 months
Contributions summary:Irwin primarily contributed to the Eclipse OMR project by implementing and refining compiler optimization features. Their work focused on enhancing the compiler's ability to handle relocatable code, as evidenced by the introduction of heuristic regions and the masking of processor flags to facilitate this functionality. The user also added new APIs related to heuristic regions and class chain validation, demonstrating a focus on improving compiler performance and supporting advanced compilation techniques. In addition, the user made changes to the compilation process and code generation for AOT.
jitruntimesomrruntimeportability
eclipse-openj9/openj9
Jan 2019 - Jan 2023
Eclipse OpenJ9: A Java Virtual Machine for OpenJDK that's optimized for small footprint, fast start-up, and high throughput. Builds on Eclipse OMR (https://github.com/eclipse/omr) and combines with the Extensions for OpenJDK for OpenJ9 repo.
Role in this project:Back-end Developer
Back-end DeveloperContributions:718 reviews, 490 commits, 484 PRs in 4 years
Contributions summary:Irwin primarily focused on improving the AOT compilation process within the Eclipse OpenJ9 JVM. Their contributions involved implementing and refining relocation records related to various components, including inlined methods and class chains. They also added features to handle exception hooks in AOT and refined the process for code generation during checkpoint/restore. Their work directly addresses reducing AOT load failures and improving overall startup performance under specific conditions within the JVM.
runtimecompilerextensionseclipseomr
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