Agner Fog
Agner Fog is a Danish scientist and independent researcher known for his extensive work on optimizing software performance, particularly for x86 processors. He is recognized for his freely available manuals and software tools related to assembly language programming, instruction scheduling, calling conventions, and microarchitecture analysis.
His research focuses on providing practical and detailed information to programmers and developers to enable them to write more efficient code. Fog's manuals cover a wide range of topics, including:
- Optimization Manuals: Detailed guides explaining how to optimize code for different x86 processor families. These manuals cover topics such as instruction timing, cache behavior, and branch prediction.
- Calling Conventions: Documentation of standard calling conventions used on various platforms, enabling interoperability between different programming languages and libraries.
- Vectorization: Guides on using Single Instruction, Multiple Data (SIMD) instructions for parallel processing.
- Microarchitecture Analysis: Descriptions of the microarchitectural details of different x86 processor generations, including information on pipeline stages, execution units, and cache hierarchies.
Fog also provides software tools like the "Optimizing Assembly inlining library" (OAIL) and other utilities designed to assist in optimizing code and analyzing performance bottlenecks.
His work is widely respected within the software development community for its depth, clarity, and practical applicability. The materials he provides are often used as a reference by compiler writers, performance engineers, and anyone seeking a deeper understanding of x86 architecture and software optimization.