/**
* Constructs and inserts a new empty GOTO block {@code Z} between this block ({@code A}) and a
* current successor block ({@code B}). The new block will replace B as A's successor and A as B's
* predecessor. A and B will no longer be directly connected. If B is listed as a successor
* multiple times, all references are replaced.
*
* @param other current successor (B)
* @return {@code non-null;} an appropriately-constructed instance
*/
public SsaBasicBlock insertNewSuccessor(SsaBasicBlock other) {
SsaBasicBlock newSucc = parent.makeNewGotoBlock();
if (!successors.get(other.index)) {
throw new RuntimeException(
"Block " + other.getRopLabelString() + " not successor of " + getRopLabelString());
}
// Update the new block.
newSucc.predecessors.set(this.index);
newSucc.successors.set(other.index);
newSucc.successorList.add(other.index);
newSucc.primarySuccessor = other.index;
// Update us.
for (int i = successorList.size() - 1; i >= 0; i--) {
if (successorList.get(i) == other.index) {
successorList.set(i, newSucc.index);
}
}
if (primarySuccessor == other.index) {
primarySuccessor = newSucc.index;
}
successors.clear(other.index);
successors.set(newSucc.index);
// Update "other".
other.predecessors.set(newSucc.index);
other.predecessors.set(index, successors.get(other.index));
return newSucc;
}
/**
* Inserts a new empty GOTO block as a predecessor to this block. All previous predecessors will
* be predecessors to the new block.
*
* @return {@code non-null;} an appropriately-constructed instance
*/
public SsaBasicBlock insertNewPredecessor() {
SsaBasicBlock newPred = parent.makeNewGotoBlock();
// Update the new block.
newPred.predecessors = predecessors;
newPred.successors.set(index);
newPred.successorList.add(index);
newPred.primarySuccessor = index;
// Update us.
predecessors = new BitSet(parent.getBlocks().size());
predecessors.set(newPred.index);
// Update our (soon-to-be) old predecessors.
for (int i = newPred.predecessors.nextSetBit(0);
i >= 0;
i = newPred.predecessors.nextSetBit(i + 1)) {
SsaBasicBlock predBlock = parent.getBlocks().get(i);
predBlock.replaceSuccessor(index, newPred.index);
}
return newPred;
}