Messages in this thread | | | Date | Fri, 25 Jul 1997 13:33:26 +0200 (MET DST) | From | Bernd Schmidt <> | Subject | Re: Pentium emulation |
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> Imagine the following situation: > > You have several PCs from 386 to Pentium (or Pentium II or whatever). > You also have programs that should run on any of your PCs. This means > you have to compile with the -m386 or -m486 option rather than > optimizing for Pentium.
No.
> Or you have a cool binary that has been compiled for Pentium but > you want to try it on a 486... > > Couldn't the kernel provide emulation of the Pentium instructions > for the 386/486, to solve this problem? I guess it could be done > since it would be very similar to the FPU emulator. > > So the question is mainly: Would it make sense?
No. There are no new Pentium opcodes other than things like RDTSC or RDMSR, which aren't really useful for normal user programs and are never generated by the compiler. Things are different with PPro/Pentium II which have a new conditional move instruction. The currently available GCC versions don't generate these either, but 2.8.0 will most likely support them. It might make sense to try to provide an emulation for those, but it would not be very useful because of the performance loss. I don't think there will be any precompiled binaries with those opcodes anytime soon.
Bernd
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