/**
* Compute the entry points for a list of hyperblocks to be inserted into the HFG. This method
* also removes the link between hbStart and all its successors.
*/
public static HashMap<Instruction, Hyperblock> computeEntries(
Hyperblock hbStart, Vector<Hyperblock> hbs) {
HashMap<Instruction, Hyperblock> entries = new HashMap<Instruction, Hyperblock>(203);
// Find the entry points in the new hyperblocks.
int l = hbs.size();
for (int i = 0; i < l; i++) {
Hyperblock hb = hbs.elementAt(i);
PredicateBlock start = hb.getFirstBlock();
Instruction first = start.getFirstInstruction();
entries.put(first, hb);
}
// The successors of the original hyperblock are also entry points.
int sl = hbStart.numOutEdges();
for (int i = 0; i < sl; i++) {
Hyperblock succ = (Hyperblock) hbStart.getOutEdge(0);
PredicateBlock start = succ.getFirstBlock();
Instruction first = start.getFirstInstruction();
hbStart.deleteOutEdge(succ);
succ.deleteInEdge(hbStart);
entries.put(first, succ);
}
return entries;
}
/** Split an unpredicated predicate block. */
private void splitBlock(Hyperblock hb, PredicateBlock block) {
int chunkSize = (block.getBlockSize() + block.getFanout()) / 2;
int maxChunk = (int) (Trips2Machine.maxBlockSize * MAXFILL);
if (chunkSize > maxChunk) {
chunkSize = maxChunk;
}
Instruction splitLocation = findSplitLocation(hb, block, chunkSize);
PredicateBlock start = block.cut(splitLocation, gen);
Hyperblock nhb = new Hyperblock(start, regs);
// Insert the new hyperblock into the HFG.
for (int i = hb.numOutEdges() - 1; i > -1; i--) {
Hyperblock out = (Hyperblock) hb.getOutEdge(i);
out.replaceInEdge(hb, nhb);
hb.deleteOutEdge(out);
nhb.addOutEdge(out);
}
hb.addOutEdge(nhb);
nhb.addInEdge(hb);
workingSet.add(nhb);
hb.invalidateDomination();
hb.findLastBlock();
hb.determinePredicatesBranches();
nhb.findLastBlock();
nhb.determinePredicatesBranches();
// Update the return block if it has changed.
if (gen.getReturnBlock() == hb) {
gen.setReturnBlock(nhb);
}
}
