IMPLICIT_DEF's

Hi, guys.

     sorry if this has already been discussed, but I still feel like clarifying: how should the register allocator handle IMPLICIT_DEF instructions? The LiveIntervalAnalysis class is assigning them zero length intervals. After I removed this, e.g, by removing the lines:

if (mi->getOpcode() == TargetInstrInfo::IMPLICIT_DEF) {
     DOUT << "is a implicit_def\n";
     return;
}

from LiveIntervalAnalysis, it makes it easier for my allocator to pass the LLVM 2.3 tests. I guess that is not really what I was supposed to do, so, what is the way that I should handle IMPLICIT_DEF's in my allocator?

All the best,

Fernando