rust-lang/gcc
Mar 2025 – Sep 2025
6 Months active
Languages Used
CC++Fortran
Technical Skills
Compiler DevelopmentCompiler TestingFortranLow-Level ProgrammingOpenMPRuntime Libraries
Paul-Antoine Arras
PROFILE
Paul-antoine Arras
Worked on the rust-lang/gcc repository, delivering a series of RISC-V vectorization and floating-point optimizations that improved code generation efficiency and test reliability. Focused on developing new instruction patterns and cost model refactoring in C and C++, enabling operation merging and reducing instruction counts for vector-scalar and floating-point workloads. Enhanced OpenMP interoperability across C, C++, and Fortran front-ends, and stabilized cross-architecture test suites. Addressed critical bugs in vector-scalar multiply-accumulate operations, ensuring robust compiler behavior. Demonstrated expertise in compiler development, assembly optimization, and vectorization, with a methodical approach to test-driven validation and maintainable backend improvements for embedded systems.
Overall Statistics
Feature vs Bugs
80%Features
Repository Contributions
27Total
Bugs
2
Commits
27
Features
8
Lines of code
7,695
Activity Months6
Your Network
317 peopleShared Repositories
280
Work History
September 2025
10 Commits • 1 Features
Sep 1, 2025Performance-focused backend work for the GCC repository rust-lang/gcc in September 2025. The principal objective was to deliver high-value optimizations for RISC-V vector-scalar floating-point operations through a new pattern suite, improving efficiency and throughput on FP workloads. Major bugs fixed: No major bugs reported in the provided data for this period; the emphasis was on feature delivery and performance enhancements. Overall impact: Introduced a set of vector-scalar FP patterns that reduce instruction count by merging vector-duplicate with vector-vector paths and optimize a broad set of operations (max, min, add, sub, and widening variants). This lays the groundwork for measurable performance gains on RISC-V vector-capable hardware and improves code quality with better documentation and tests. Technologies/skills demonstrated: RISC-V vector back-end optimization, pattern matching in the GCC backend, FP optimization strategies, test-driven development, and documentation practices.
10 Commits • 1 Features
Sep 1, 2025Performance-focused backend work for the GCC repository rust-lang/gcc in September 2025. The principal objective was to deliver high-value optimizations for RISC-V vector-scalar floating-point operations through a new pattern suite, improving efficiency and throughput on FP workloads. Major bugs fixed: No major bugs reported in the provided data for this period; the emphasis was on feature delivery and performance enhancements. Overall impact: Introduced a set of vector-scalar FP patterns that reduce instruction count by merging vector-duplicate with vector-vector paths and optimize a broad set of operations (max, min, add, sub, and widening variants). This lays the groundwork for measurable performance gains on RISC-V vector-capable hardware and improves code quality with better documentation and tests. Technologies/skills demonstrated: RISC-V vector back-end optimization, pattern matching in the GCC backend, FP optimization strategies, test-driven development, and documentation practices.
September 2025
August 2025
6 Commits • 1 Features
Aug 1, 2025In August 2025, focused on delivering core architectural optimizations for RISC-V vector FP paths in rust-lang/gcc and stabilizing the related test suite. Key outcomes include new FP vectorization patterns that reduce instruction counts and improve throughput for vector-scalar operations, and targeted test-suite improvements that enhance reliability and accuracy for the zvfh extension. The work supports faster, safer optimizations in RISC-V environments and strengthens confidence in FP path correctness.
August 2025
6 Commits • 1 Features
Aug 1, 2025In August 2025, focused on delivering core architectural optimizations for RISC-V vector FP paths in rust-lang/gcc and stabilizing the related test suite. Key outcomes include new FP vectorization patterns that reduce instruction counts and improve throughput for vector-scalar operations, and targeted test-suite improvements that enhance reliability and accuracy for the zvfh extension. The work supports faster, safer optimizations in RISC-V environments and strengthens confidence in FP path correctness.
July 2025
3 Commits • 2 Features
Jul 1, 2025July 2025: Key feature deliveries and stability improvements on the RISC-V target in the rust-lang/gcc repo. Highlights include enabling the zvfh extension for vector-scalar half-float tests with per-testcase enabling and adjusted MAX_RELATIVE_DIFF to improve test accuracy, and introducing vector-scalar widening patterns for multiply-(subtract-)accumulate and for widening negate-multiply-(subtract-)accumulate to enhance codegen and reduce instruction count. Documentation and test updates accompany these changes, improving overall test coverage and maintainability.
3 Commits • 2 Features
Jul 1, 2025July 2025: Key feature deliveries and stability improvements on the RISC-V target in the rust-lang/gcc repo. Highlights include enabling the zvfh extension for vector-scalar half-float tests with per-testcase enabling and adjusted MAX_RELATIVE_DIFF to improve test accuracy, and introducing vector-scalar widening patterns for multiply-(subtract-)accumulate and for widening negate-multiply-(subtract-)accumulate to enhance codegen and reduce instruction count. Documentation and test updates accompany these changes, improving overall test coverage and maintainability.
July 2025
June 2025
4 Commits • 1 Features
Jun 1, 2025June 2025 performance summary for rust-lang/gcc. Focused on RISC-V vector optimizations: introduced new instruction patterns for vector-scalar negate-(multiply-add/sub) and vector-scalar multiply-(subtract-) accumulate, with autovec-opt and vector/test suite updates, enabling operation merging and reducing instruction count. A critical bug in vector-scalar multiply-accumulate was fixed by correcting operand handling in prepare_ternary_operands, eliminating an internal compiler error. Impact: improved code generation efficiency and robustness for the RISC-V vector extension, supporting faster, smaller-vector workloads and more reliable builds. Technologies demonstrated: low-level pattern-based optimizations, RISC-V vector extension, autovec, and comprehensive vector test suites.
June 2025
4 Commits • 1 Features
Jun 1, 2025June 2025 performance summary for rust-lang/gcc. Focused on RISC-V vector optimizations: introduced new instruction patterns for vector-scalar negate-(multiply-add/sub) and vector-scalar multiply-(subtract-) accumulate, with autovec-opt and vector/test suite updates, enabling operation merging and reducing instruction count. A critical bug in vector-scalar multiply-accumulate was fixed by correcting operand handling in prepare_ternary_operands, eliminating an internal compiler error. Impact: improved code generation efficiency and robustness for the RISC-V vector extension, supporting faster, smaller-vector workloads and more reliable builds. Technologies demonstrated: low-level pattern-based optimizations, RISC-V vector extension, autovec, and comprehensive vector test suites.
May 2025
2 Commits • 2 Features
May 1, 2025May 2025 (2025-05) performance and craftsmanship focus in rust-lang/gcc, with emphasis on RISC-V vectorization patterns and cost-model maintainability. Two key features delivered: - RISC-V vector-scalar MADD/SUB fusion optimization: introduced a pattern to fuse vec_duplicate with vfmadd.vv or vfmsub.vv into a single vfmadd.vf or vfmsub.vf instruction, reducing dynamic instruction counts and potential gains on vectorized workloads (e.g., SPEC2017 503.bwaves_r). Commit: b437418bc9547073ec2704398c85c52e060e1fab. - RISC-V compiler cost model refactor (get_fr2vr_cost): refactored the cost calculation for moving data from floating-point registers to vector registers to use get_fr2vr_cost() instead of a constant, improving consistency across configuration files and maintainability. Commit: 5566b20dd5f7fa14d93d2808414bf72882ec567e. Major bugs fixed: None reported for rust-lang/gcc in May 2025. Overall impact: Strengthened RISC-V vectorization capabilities and improved maintainability of the cost model, supporting future performance tuning and more predictable configuration behavior. These changes lay groundwork for measurable performance improvements in vector-heavy workloads and reduce configuration drift across targets. Technologies/skills demonstrated: RISC-V vector ISA patterns, GCC optimization passes, pattern-based fusion optimizations, compiler cost-model design, code maintainability, commit hygiene, cross-file configurability.
2 Commits • 2 Features
May 1, 2025May 2025 (2025-05) performance and craftsmanship focus in rust-lang/gcc, with emphasis on RISC-V vectorization patterns and cost-model maintainability. Two key features delivered: - RISC-V vector-scalar MADD/SUB fusion optimization: introduced a pattern to fuse vec_duplicate with vfmadd.vv or vfmsub.vv into a single vfmadd.vf or vfmsub.vf instruction, reducing dynamic instruction counts and potential gains on vectorized workloads (e.g., SPEC2017 503.bwaves_r). Commit: b437418bc9547073ec2704398c85c52e060e1fab. - RISC-V compiler cost model refactor (get_fr2vr_cost): refactored the cost calculation for moving data from floating-point registers to vector registers to use get_fr2vr_cost() instead of a constant, improving consistency across configuration files and maintainability. Commit: 5566b20dd5f7fa14d93d2808414bf72882ec567e. Major bugs fixed: None reported for rust-lang/gcc in May 2025. Overall impact: Strengthened RISC-V vectorization capabilities and improved maintainability of the cost model, supporting future performance tuning and more predictable configuration behavior. These changes lay groundwork for measurable performance improvements in vector-heavy workloads and reduce configuration drift across targets. Technologies/skills demonstrated: RISC-V vector ISA patterns, GCC optimization passes, pattern-based fusion optimizations, compiler cost-model design, code maintainability, commit hygiene, cross-file configurability.
May 2025
March 2025
2 Commits • 1 Features
Mar 1, 2025March 2025: OpenMP Interoperability Support delivered in rust-lang/gcc. Implemented middle-end interop support in the omplower pass, added target-independent libgomp runtime components, and front-end changes for C, C++, and Fortran. Expanded test suite to validate interoperability across architectures (32-bit and 64-bit); fixed Fortran test to stabilize interop validation. Early commits include 99e2906: OpenMP interop - ME support + target-independent libgomp and e0a1d0e: interop - fix Fortran test. This work establishes cross-runtime OpenMP interoperability and improves portability across toolchains.
March 2025
2 Commits • 1 Features
Mar 1, 2025March 2025: OpenMP Interoperability Support delivered in rust-lang/gcc. Implemented middle-end interop support in the omplower pass, added target-independent libgomp runtime components, and front-end changes for C, C++, and Fortran. Expanded test suite to validate interoperability across architectures (32-bit and 64-bit); fixed Fortran test to stabilize interop validation. Early commits include 99e2906: OpenMP interop - ME support + target-independent libgomp and e0a1d0e: interop - fix Fortran test. This work establishes cross-runtime OpenMP interoperability and improves portability across toolchains.
Activity
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Quality Metrics
Correctness98.8%
Maintainability93.4%
Architecture96.6%
Performance97.8%
AI Usage20.0%
Skills & Technologies
Programming Languages
CC++Fortran
Technical Skills
Assembly LanguageAssembly OptimizationCode RefactoringCompiler DevelopmentCompiler OptimizationCompiler TestingEmbedded SystemsFortranLow-Level ProgrammingOpenMPOptimizationPerformance OptimizationRISC-VRISC-V ArchitectureRISC-V Assembly
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