[llvm] r185966 - Reapply an improved version of r180816/180817.

[Adrian Prantl]

Hey Eric,

thanks for the comments!


On Jul 9, 2013, at 2:15 PM, Eric Christopher <echristo at gmail.com> wrote:

>> bool LDVImpl::handleDebugValue(MachineInstr *MI, SlotIndex Idx) {
>>   // DBG_VALUE loc, offset, variable
>>   if (MI->getNumOperands() != 3 ||
>> -      !MI->getOperand(1).isImm() || !MI->getOperand(2).isMetadata()) {
>> +      !(MI->getOperand(1).isReg() || MI->getOperand(1).isImm()) ||
>> +      !MI->getOperand(2).isMetadata()) {
> 
> Mind commenting this a bit more on what we aren't handling?

I’m not sure if I can come up with a comprehensive list of cases that are not handled. One case that I can think of would be a FrameIndex DBG_VALUE, but I’m not even sure whether they can even be introduced before LDV is run. 


>> -  FuncInfo.ArgDbgValues.push_back(
>> +    FuncInfo.ArgDbgValues.push_back(BuildMI(MF, getCurDebugLoc(),
>> +                                            TII->get(TargetOpcode::DBG_VALUE),
>> +                                            /* IsIndirect */ Offset != 0,
>> +                                            Op->getReg(), Offset, Variable));
>> 
> 
> Curious about the "Offset != 0" since we could have a 0 offset in the
> dbg.value intrinsic coming in yes?

I agree! I’m gradually pushing the problem up layer by layer. Currently this is just a more explicit notation of the status quo. I will add in a comment.

cheers,
Adrian