Raymond Chen on an x86 emulator team patching bad code during emulation

Category: Engineering post
Status: discussion
Sources: The Old New Thing, HN discussion
Summary: A 2026-06-15 Old New Thing post recounts an x86-on-ARM emulator team encountering code pathological enough for the emulator's just-in-time translator that they special-cased it and effectively fixed it during emulation rather than translating it faithfully. The post is a short engineering anecdote on emulation and JIT-translation edge cases.
Why it matters: It is a concrete look at how binary-translation emulators handle adversarial or degenerate instruction patterns, relevant to anyone running x86 workloads under ARM translation layers.