* @param newOpcode A RegOp from {@link RegOps}
*/
private void replacePlainInsn(NormalSsaInsn insn,
RegisterSpecList newSources, int newOpcode) {
Insn originalRopInsn = insn.getOriginalRopInsn();
Rop newRop = Rops.ropFor(newOpcode,
insn.getResult(), newSources, null);
Insn newRopInsn = new PlainInsn(newRop,
originalRopInsn.getPosition(), insn.getResult(),
newSources);
NormalSsaInsn newInsn
= new NormalSsaInsn(newRopInsn, insn.getBlock());