WebAssembly (Wasm) is a compact, well-specified bytecode format that offers a portable compilation target with near-native execution speed. The bytecode format was specifically designed to be fast to parse, validate, and compile, positioning itself as a portable alternative to native code. It was pointedly not designed to be interpreted directly. Instead, design considerations at the time focused on competing with native code, utilizing optimizing compilers as the primary execution tier. Yet, in JIT scenarios, compilation time and memory consumption critically impact application startup, leading many Wasm engines to later deploy faster single-pass (baseline) compilers. Though faster, baseline compilers still take time and waste code space for infrequently executed code. A typical interpreter being infeasible, some engines resort to compiling Wasm not to machine code, but to a more compact, but easy to interpret format. This still takes time and wastes memory. Instead, we introduce in this article a fast in-place interpreter for WebAssembly, where no rewrite and no separate format is necessary. Our evaluation shows that in-place interpretation of Wasm code is space-efficient and fast, achieving performance on-par with interpreting a custom-designed internal format. This fills a hole in the execution tier space for Wasm, allowing for even faster startup and lower memory footprint than previous engine configurations.
Thu 8 DecDisplayed time zone: Auckland, Wellington change
10:30 - 12:00
|A Fast In-Place Interpreter for WebAssembly
Ben L. Titzer Carnegie Mellon UniversityDOI
|Optimal Heap Limits for Reducing Browser Memory Use
Marisa Kirisame University of Utah, Pranav Shenoy University of Utah, Pavel Panchekha University of UtahDOI
|The Road Not Taken: Exploring Alias Analysis Based Optimizations Missed by the Compiler