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iximeow / yaxpeax-x86

x86 decoders for the yaxpeax project
BSD Zero Clause License
129 stars 23 forks source link

x86-64 doesn't require 3DNow as the README claims #36

Open fuel-pcbox opened 1 month ago

fuel-pcbox commented 1 month ago

No Intel CPU has ever supported 3DNow instructions, and 3DNow isn't required by the x86-64 specifications, but the README claims it is for some reason.

iximeow commented 1 month ago

yeah, that's outright wrong. i'm not sure why i wrote that. 3dnow is accepted by the decoders by default though, even though those instructions presumably #UD on real hardware from the last decade and a half. thank you for filing the issue.

incidentally that means all the helpers to configure decoders for specific microarchitectures are also wrong (since they build on InstDecoder::minimal() and that itself is wrong). so, i'll fix that up at some point this week..