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Raphael Moreira Zinsly

PROFILE

Raphael Moreira Zinsly

Worked on compiler back-end development and low-level systems programming, focusing on RISC-V and SH architectures across the espressif/llvm-project and rust-lang/gcc repositories. Delivered stack clash protection and stack probing for RISC-V, including enhancements for vector (RVV) and dynamic memory allocations, using C, C++, and LLVM IR. Improved code generation by optimizing right-shift recognition for the SH architecture and expanded vector extension support for RISC-V, enhancing both performance and reliability. Addressed stack probing correctness and vector permutation bugs, contributing robust tests and debugging workflows. Demonstrated depth in assembly optimization, memory management, and embedded systems through targeted, security-focused engineering solutions.

Overall Statistics

Feature vs Bugs

80%Features

Repository Contributions

7Total
Bugs
1
Commits
7
Features
4
Lines of code
3,559
Activity Months5

Work History

October 2025

2 Commits

Oct 1, 2025

October 2025: Focused on RISC-V architecture correctness in the rust-lang/gcc repo. Implemented critical stack-probing reliability fixes and slide-pattern recognition improvements, with tests added to prevent regressions. These changes enhance codegen reliability on RV architectures (RV64/RV32), reduce miscompilation risk, and strengthen test coverage for future RV-related work.

September 2025

1 Commits • 1 Features

Sep 1, 2025

September 2025 monthly summary focused on RISC-V vector extension improvements in rust-lang/gcc, with extended shuffle_slide_patterns recognition and expanded tests to boost vectorization reliability and performance potential.

June 2025

1 Commits • 1 Features

Jun 1, 2025

June 2025 monthly summary for rust-lang/gcc: Focused on performance-oriented back-end optimization in the SH architecture. Delivered an optimization to recognize right-shifts by 31, generating more efficient code for affected cases. Implemented by introducing a new SH backend function, sh_recog_treg_set_expr_not_01, to improve recognition of expressions like >> 31. This change reduces the instruction count in generated assembly, enhancing runtime performance and code quality for critical SH paths. The work was committed in a single change with message "sh: Recognize >> 31 in treg_set_expr_not_const01" (commit eda5a15909c315f0a4a7e76ad083f5f16cf1aef9).

January 2025

2 Commits • 1 Features

Jan 1, 2025

January 2025: Delivered stack clash protection enhancements for RISC-V RVV allocations and dynamic memory allocations in espressif/llvm-project. Implemented stack-clash safe RVV vector allocations via RISCV::PROBED_STACKALLOC_RVV, introduced frame lowering changes for variable-sized RVV stack probing, and added a runtime probing loop with SelectionDAG support for dynamic allocations to ensure stack safety at runtime. These changes improve memory safety for RVV workloads and reduce risk of runtime crashes or instability in production builds, aligning with reliability and safety goals for vector workloads.

December 2024

1 Commits • 1 Features

Dec 1, 2024

December 2024 monthly summary for espressif/llvm-project: Implemented RISC-V stack clash protection and stack probing to harden stack usage and prevent overflows. Enabled -fstack-clash-protection for RISC-V, added stack probing in function prologues, and updated the Clang driver and RISC-V backend to allocate stacks with probing. Implemented unrolled and variable-length probing loops to cover different allocation sizes. All changes are in commit 708a478d6739aea20a8834cea45490f05b07ca10 ( RISCV: Add stack clash protection ).

Activity

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Quality Metrics

Correctness97.2%
Maintainability82.8%
Architecture85.8%
Performance87.2%
AI Usage20.0%

Skills & Technologies

Programming Languages

CC++LLVM IR

Technical Skills

Assembly LanguageAssembly OptimizationCompiler DevelopmentEmbedded SystemsLow-Level OptimizationLow-Level Systems ProgrammingMemory ManagementRISC-V ArchitectureStack ManagementVector Extensions

Repositories Contributed To

2 repos

Overview of all repositories you've contributed to across your timeline

rust-lang/gcc

Jun 2025 Oct 2025
3 Months active

Languages Used

C

Technical Skills

Assembly OptimizationCompiler DevelopmentEmbedded SystemsAssembly LanguageRISC-V ArchitectureVector Extensions

espressif/llvm-project

Dec 2024 Jan 2025
2 Months active

Languages Used

C++LLVM IR

Technical Skills

Compiler DevelopmentEmbedded SystemsLow-Level Systems ProgrammingRISC-V ArchitectureAssembly LanguageLow-Level Optimization