[LLVMdev] Prolog/Epilog Insertion Question

[David Greene]

I've been looking through the code for pologue/epilogoue generation and
noticed this oddity:

void PEI::replaceFrameIndices(MachineFunction &Fn) {
  [...]
    for (MachineBasicBlock::iterator I = BB->begin(); I != BB->end(); ) {
        [...]
      if (I->getOpcode() == FrameSetupOpcode ||
          I->getOpcode() == FrameDestroyOpcode) {
        [...]
      } else {
        [...]
        for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i)
          if (MI->getOperand(i).isFrameIndex()) {
            // If this instruction has a FrameIndex operand, we need to use 
            // that
            // target machine register info object to eliminate it.
            MRI.eliminateFrameIndex(MI, SPAdj, RS);

            // Revisit the instruction in full.  Some instructions (e.g. 
            // inline
            // asm instructions) can have multiple frame indices.
            --I;
            MI = 0;
            break;
          }
      }
      // Update register states.
      if (RS && MI) RS->forward(MI);
    }

The break causes the instruction to be reprocessed but forward() is called
on the register scavenger.  Doesn't this create an inconsistency?

                                               -Dave