JavaScript AOT compilation

International audienceStatic compilation, a.k.a., ahead-of-time (AOT) compilation, is an alternative approach to JIT compilation that can combine good speed and lightweight memory footprint, and that can accommodate read-only memory constraints that are imposed by some devices and some operating systems. Unfortunately the highly dynamic nature of JavaScript makes it hard to compile statically and all existing AOT compilers have either gave up on good performance or full language support. We have designed and implemented an AOT compiler that aims at satisfying both. It supports full unrestricted ECMAScript 5.1 plus many ECMAScript 2017 features and the majority of benchmarks are within 50% of the performance of one of the fastest JIT compilers

Efficient dynamic language for technical computing

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 56-60).Dynamic programming languages have become popular for scientific computing. They are generally considered highly productive, but lacking in performance. This thesis presents a new dynamic language for technical computing, designed for performance from the beginning by adapting and extending modem programming language techniques. A design based on generic functions and a rich type system simultaneously enables an expressive programming model and successful type inference, leading to good performance for a wide range of programs. In our system, more behavior can be defined in libraries and user code, allowing our infrastructure to be shared across disciplines.by Jeffrey Werner Bezanson.S.M

Shader optimization and specialization

In the field of real-time graphics for computer games, performance has a significant effect on the player’s enjoyment and immersion. Graphics processing units (GPUs) are hardware accelerators that run small parallelized shader programs to speed up computationally expensive rendering calculations. This thesis examines optimizing shader programs and explores ways in which data patterns on both the CPU and GPU can be analyzed to automatically speed up rendering in games. Initially, the effect of traditional compiler optimizations on shader source-code was explored. Techniques such as loop unrolling or arithmetic reassociation provided speed-ups on several devices, but different GPU hardware responded differently to each set of optimizations. Analyzing execution traces from numerous popular PC games revealed that much of the data passed from CPU-based API calls to GPU-based shaders is either unused, or remains constant. A system was developed to capture this constant data and fold it into the shaders’ source-code. Re-running the game’s rendering code using these specialized shader variants resulted in performance improvements in several commercial games without impacting their visual quality