On Apple silicon, there's a fun new twist: the instruction (I) and data (D) caches are separate, so you have to remember to call sys_icache_flush [1] to keep them in sync!

If you don't handle this correctly, then you'll have a Very Fun time [2].

What's especially Fun is that if you halt your program in a debugger and read back the contents of the JIT buffer, it will look perfectly correct – because those reads are coming through RAM / DCache, not ICache!

[1] https://developer.apple.com/library/archive/documentation/Sy... [2] https://twitter.com/impraxical/status/1579586601117548544