private static FatBlock newFatBlock(int startNodeIndex, int endNodeIndex) {
FatBlock fb = new FatBlock();
fb.realBlock = new Block(startNodeIndex, endNodeIndex);
return fb;
}
private static Block[] buildBlocks(Node[] statementNodes) {
// a mapping from each target node to the block it begins
Map<Node, FatBlock> theTargetBlocks = new HashMap<Node, FatBlock>();
ObjArray theBlocks = new ObjArray();
// there's a block that starts at index 0
int beginNodeIndex = 0;
for (int i = 0; i < statementNodes.length; i++) {
switch (statementNodes[i].getType()) {
case Token.TARGET:
{
if (i != beginNodeIndex) {
FatBlock fb = newFatBlock(beginNodeIndex, i - 1);
if (statementNodes[beginNodeIndex].getType() == Token.TARGET)
theTargetBlocks.put(statementNodes[beginNodeIndex], fb);
theBlocks.add(fb);
// start the next block at this node
beginNodeIndex = i;
}
}
break;
case Token.IFNE:
case Token.IFEQ:
case Token.GOTO:
{
FatBlock fb = newFatBlock(beginNodeIndex, i);
if (statementNodes[beginNodeIndex].getType() == Token.TARGET)
theTargetBlocks.put(statementNodes[beginNodeIndex], fb);
theBlocks.add(fb);
// start the next block at the next node
beginNodeIndex = i + 1;
}
break;
}
}
if (beginNodeIndex != statementNodes.length) {
FatBlock fb = newFatBlock(beginNodeIndex, statementNodes.length - 1);
if (statementNodes[beginNodeIndex].getType() == Token.TARGET)
theTargetBlocks.put(statementNodes[beginNodeIndex], fb);
theBlocks.add(fb);
}
// build successor and predecessor links
for (int i = 0; i < theBlocks.size(); i++) {
FatBlock fb = (FatBlock) (theBlocks.get(i));
Node blockEndNode = statementNodes[fb.realBlock.itsEndNodeIndex];
int blockEndNodeType = blockEndNode.getType();
if ((blockEndNodeType != Token.GOTO) && (i < (theBlocks.size() - 1))) {
FatBlock fallThruTarget = (FatBlock) (theBlocks.get(i + 1));
fb.addSuccessor(fallThruTarget);
fallThruTarget.addPredecessor(fb);
}
if ((blockEndNodeType == Token.IFNE)
|| (blockEndNodeType == Token.IFEQ)
|| (blockEndNodeType == Token.GOTO)) {
Node target = ((Jump) blockEndNode).target;
FatBlock branchTargetBlock = theTargetBlocks.get(target);
target.putProp(Node.TARGETBLOCK_PROP, branchTargetBlock.realBlock);
fb.addSuccessor(branchTargetBlock);
branchTargetBlock.addPredecessor(fb);
}
}
Block[] result = new Block[theBlocks.size()];
for (int i = 0; i < theBlocks.size(); i++) {
FatBlock fb = (FatBlock) (theBlocks.get(i));
Block b = fb.realBlock;
b.itsSuccessors = fb.getSuccessors();
b.itsPredecessors = fb.getPredecessors();
b.itsBlockID = i;
result[i] = b;
}
return result;
}
