[PATCH] D13749: x86 atomic codegen: don't drop globals

[Pete Cooper via llvm-commits]

pete added a comment.



> I'm not a huge fan of the code duplication, but it seems easier to read that cleverly reusing partially-constructed MIs.


Yeah, this isn't the easiest thing to avoid here.

One option is to change addDisp to take an Optional<MachineOperand> or something like that which only applies the displacement when its set.

Another alternative is that you create a temporary MachineOperand on the stack and rely on the code in addDisp which checks for immediates, and if they are immediates just adds to them.  That is, you could do

MachineOperand ZeroDisp = MachineOperand::createImm(0);
BuildMI(...)
.add...
.addDisp(hasDisp ? Disp : ZeroDisp)

then you won't have any duplication.  Thats the least duplication I could come up with.

Cheers!
Pete


http://reviews.llvm.org/D13749