[LLVMdev] Mapping bytecode to X86

[Chris Lattner]

On Mon, 26 Jun 2006, Fernando Magno Quintao Pereira wrote:
>>> Thank you Chris. I will try to implement the TwoAddress pass to run on
>>> machine code. Why it has not been originally implemented to run on
>>> machine code?
>>
>> I'm not sure what you mean.  It definitely does run on machine code.
>
> I was thinking that it only transformed instructions with virtual
> registers because of this code in the TwoAddressInstructionPass.cpp:
>
>        unsigned regA = mi->getOperand(0).getReg();
>        unsigned regB = mi->getOperand(1).getReg();
>
>        assert(MRegisterInfo::isVirtualRegister(regA) &&
>               MRegisterInfo::isVirtualRegister(regB) &&
>               "cannot update physical register live information");
>
> By machine code I meant code with virtual registers, instead of machine
> (physical) registers; not the passes on machine functions/machine basic
> blocks.

Right. Two address instructions can only use virtual registers, not 
physical registers.

-Chris

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