4 ms·
They would also need to know which specific instructions are really invalid and which just don’t exist on this specific core. X86 doesn’t make that easy.
by jdsully 5y ago
They would also need to know which specific instructions are really invalid and which just don’t exist on this specific core.
X86 doesn’t make that easy.
- rbanffy 5y agoCPU flags should take care of that. Besides, you can examine where the program counter was when the core encountered the invalid instruction. I wouldn't be surprised if the x86 would let us down here however. Wouldn't be the 8367th time.
- jdsully 5y agoThere’s no CPU flag to say “this instruction exists on another core”. X86 disassemblers are very complex if you want to handle more than just the happy path. X86 instructions can be up to 15 bytes long. Then there is the issue with new instructions that get added.