Emscripten and asm.js: C++'s role in the modern web

on YouTube ↗59m

" summary

LLVM+clang → Emscripten emits JavaScript (an asm.js subset) that views program memory as an ArrayBuffer heap with typed‑array views, uses tricks like or|0 coercion for 32‑bit integers, and maps C++ exceptions onto JS exceptions. Measured performance sits around 50–67% of native on large benchmarks (Box2D, Bullet, Lua VM, zlib); big builds take seconds (roughly 5–10s) to compile, current limits include 32‑bit integer emulation and no shared‑memory threads (only web workers).

AI-written summary · about

" chapters (10)

1. 0:00The case for C++ on the web
2. 2:00Compiling C++ to JavaScript
3. 4:29Working with Emscripten
4. 6:06Architecture and libraries
5. 8:28Emitted code and asm.js
6. 14:49Fundamental design differences
7. 21:06Performance optimization
8. 25:15Benchmarks and real-world use
9. 31:43Handling exceptions
10. 37:54Q&A and closing thoughts

" related talks

• 45mEmscriptenAlon Zakai · JSConf EU 2011
• 39mBringing the power of C++ to the webKrzysztof Paprocki · Meeting C++ 2019
• 39mWebAssembly for the rest of usJan-Erik Rediger · Codemotion Amsterdam 2017
• 23mA Love Story Between JavaScript and C++Fredy Andrade · JSConfCO 2018
• 30mNative Speed on the Web: JavaScript and asm.jsAlon Zakai · Strange Loop 2013
• 42mWebAssembly: A New Compilation Target for the WebLuke Wagner · Philly ETE 2016
• 46mTurbocharging Client-Side Processing: Leveraging asm.jsVladimir Vukicevic · Spotlight: Advanced JS 2013
• 42mWebAssembly? Web and Assembler? WTF!Nicolas Decoster · DevFest Toulouse 2017