Abstract visualization of a JIT compiler pipeline transforming bytecode into optimized machine code

Inside V8's TurboFan's Maglev: How Speculative JIT Compilation Powers Modern JavaScript

Maglev is V8’s mid-tier JIT compiler sitting between Sparkplug and TurboFan. It uses speculative type feedback and SSA-based IR to compile hot functions quickly while preserving most of TurboFan’s optimization headroom.

September 7, 2026 · 11 min · 2228 words · martinuke0
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