{
// We start with as early as possible nulls. Now we switch to
// as late as possible to prevent excess nulling
RegisterSet needsNull= RegisterSet.none();
InstructionActions act= null;
OnePathInstructionRegisterContents last= null;
for (OnePathInstructionRegisterContents curInst : c.path)
{
last= curInst;
act= beenTo.get(curInst.instruction);
needsNull.orEq(act.useInfo.willNull);