processBackwardBranch(int index, int branchtarget, short b2BBMap[], VM_BasicBlock basicBlocks[]) {
private void processBackwardBranch(int index, int branchtarget) {
  processBackwardBranch(int index, int branchtarget, short b2BBMap[],                         VM_BasicBlock basicBlocks[]) {    VM_BasicBlock existingBB, currentBB, newBB, targetBB;    int newBlockNum, i, newBlockEnd;    existingBB = basicBlocks[b2BBMap[branchtarget]];    if (existingBB.getStart() != branchtarget) {      // Need to split the existing block in two, by ending the existing block      // at the previous instruction and starting a new block at the branchtarget      // Need to split the existing block in two. It is best to set up the new      // block to end at the instruction before the target and the existing      // block to start at the target. That way the tail stays the same.       newBB = new VM_BasicBlock(existingBB.getStart());      basicBlocks = addBasicBlock(newBB, basicBlocks);      newBlockNum = newBB.getBlockNumber();      existingBB.setStart(branchtarget);      // Find the last instruction prior to the branch target;      //  that's the end of the new block      //      for (i=branchtarget-1; b2BBMap[i]==VM_BasicBlock.NOTBLOCK; i--);      newBlockEnd = i;      newBB.setEnd(i);      // Going forwards, mark the start of each instruction with the new block       // number      //      for (i=newBB.getStart(); i<=newBlockEnd; i++) {	if (b2BBMap[i] != VM_BasicBlock.NOTBLOCK)	  b2BBMap[i]= (short)newBlockNum;      }      VM_BasicBlock.transferPredecessors(existingBB, newBB);      // The new block is a predecessor of the existing block      existingBB.addPredecessor(newBB);    }    else {}  // Nice coincidence, the existing block starts at "branchtarget"    // Now mark the "current" block (the one that ends at "index") as a predecessor    // of the target block (which is either the existing block or a newly made     // block)    //    currentBB = basicBlocks[b2BBMap[index]];    existingBB.addPredecessor(currentBB);    return basicBlocks;      }