public RPST build() {
// find canonical regions
detectRegions();
// build tree of canonical regions
RPSTRegion root = new RPSTRegion(cfg.getEntryBlock(), null);
buildRegionTree(cfg.getEntryBlock(), root);
// build children
for (RPSTRegion r : bb2region.values()) {
for (RPSTRegion r2 = r; r2 != null; r2 = r2.parent) {
if (r2.parent != null) {
r2.parent.children.add(r2);
}
}
}
RPST rpst = new RPST(cfg, new RegionImpl(cfg.getEntryBlock(), null, ParentType.ROOT));
Map<RPSTRegion, Region> mapR = new HashMap<>();
a(root, rpst.getRootRegion(), rpst, mapR);
for (Map.Entry<BasicBlock, RPSTRegion> entry : bb2region.entrySet()) {
BasicBlock bb = entry.getKey();
RPSTRegion r = entry.getValue();
Region r2 = mapR.get(r);
rpst.addRegion(bb, r2);
}
// add non canonical region to the tree
findNonCanonicalRegions(rpst, rpst.getRootRegion());
return rpst;
}
private void a(RPSTRegion r, Region r2, RPST rpst, Map<RPSTRegion, Region> mapR) {
mapR.put(r, r2);
for (RPSTRegion c : r.children) {
Region c2 = new RegionImpl(c.entry, c.exit, ParentType.UNDEFINED);
rpst.addRegion(c2, r2);
a(c, c2, rpst, mapR);
}
}
private void findNonCanonicalRegions(RPST rpst, Region region) {
Set<Region> childrenBefore = new HashSet<>(rpst.getChildren(region));
if (rpst.getChildCount(region) > 1) {
boolean found = true;
while (found) {
found = false;
// children ordered by dominance
List<Region> children = new ArrayList<>(rpst.getChildren(region));
Collections.sort(
children,
new Comparator<Region>() {
@Override
public int compare(Region region1, Region region2) {
return getDomInfo().dominates(region1.getEntry(), region2.getEntry()) ? 1 : -1;
}
});
for (Region child1 : children) {
for (Region child2 : children) {
if (!child1.equals(child2)) {
if (isNonCanonicalRegion(rpst, child1, child2)) {
Region newRegion =
new RegionImpl(child1.getEntry(), child2.getExit(), ParentType.UNDEFINED);
LOGGER.debug("New non canonical region {}", newRegion);
rpst.addRegion(newRegion, region);
rpst.setNewParent(child1, newRegion);
rpst.setNewParent(child2, newRegion);
found = true;
break;
}
}
}
if (found) {
break;
}
}
}
}
for (Region child : childrenBefore) {
findNonCanonicalRegions(rpst, child);
}
}
/** Test if two canonical regions could be merge in one non canonical region. */
private boolean isNonCanonicalRegion(RPST rpst, Region region1, Region region2) {
if (!region1.getExit().equals(region2.getEntry())) {
return false;
}
if (rpst.getChildCount(region2) == 0) {
return false;
}
// basic blocks of merged region
Set<BasicBlock> basicBlocks = new HashSet<>();
basicBlocks.addAll(rpst.getBasicBlocks(region1));
basicBlocks.addAll(rpst.getBasicBlocks(region2));
basicBlocks.add(region2.getExit());
if (!basicBlocks.containsAll(cfg.getSuccessorsOf(region1.getExit()))) {
return false;
}
if (!basicBlocks.containsAll(cfg.getPredecessorsOf(region1.getExit()))) {
return false;
}
return true;
}
