return find(Blocks.begin(), Blocks.end(), BB) != Blocks.end();
}
+bool Loop::isLoopExit(const BasicBlock *BB) const {
+ for (BasicBlock::succ_const_iterator SI = succ_begin(BB), SE = succ_end(BB);
+ SI != SE; ++SI) {
+ if (!contains(*SI))
+ return true;
+ }
+ return false;
+}
+
+unsigned Loop::getNumBackEdges() const {
+ unsigned NumBackEdges = 0;
+ BasicBlock *H = getHeader();
+
+ for (std::vector<BasicBlock*>::const_iterator I = Blocks.begin(),
+ E = Blocks.end(); I != E; ++I)
+ for (BasicBlock::succ_iterator SI = succ_begin(*I), SE = succ_end(*I);
+ SI != SE; ++SI)
+ if (*SI == H)
+ ++NumBackEdges;
+
+ return NumBackEdges;
+}
+
void Loop::print(std::ostream &OS) const {
OS << std::string(getLoopDepth()*2, ' ') << "Loop Containing: ";
for (unsigned i = 0; i < getBlocks().size(); ++i) {
if (i) OS << ",";
- WriteAsOperand(OS, (const Value*)getBlocks()[i]);
+ WriteAsOperand(OS, getBlocks()[i], false);
}
+ if (!ExitBlocks.empty()) {
+ OS << "\tExitBlocks: ";
+ for (unsigned i = 0; i < getExitBlocks().size(); ++i) {
+ if (i) OS << ",";
+ WriteAsOperand(OS, getExitBlocks()[i], false);
+ }
+ }
+
OS << "\n";
- std::copy(getSubLoops().begin(), getSubLoops().end(),
- std::ostream_iterator<const Loop*>(OS, "\n"));
+ for (unsigned i = 0, e = getSubLoops().size(); i != e; ++i)
+ getSubLoops()[i]->print(OS);
}
+void Loop::dump() const {
+ print(std::cerr);
+}
+
+
//===----------------------------------------------------------------------===//
// LoopInfo implementation
//
void LoopInfo::print(std::ostream &OS) const {
for (unsigned i = 0; i < TopLevelLoops.size(); ++i)
TopLevelLoops[i]->print(OS);
+#if 0
+ for (std::map<BasicBlock*, Loop*>::const_iterator I = BBMap.begin(),
+ E = BBMap.end(); I != E; ++I)
+ OS << "BB '" << I->first->getName() << "' level = "
+ << I->second->LoopDepth << "\n";
+#endif
}
Loop *LoopInfo::ConsiderForLoop(BasicBlock *BB, const DominatorSet &DS) {
BasicBlock *X = TodoStack.back();
TodoStack.pop_back();
- if (!L->contains(X)) { // As of yet unprocessed??
+ if (!L->contains(X)) { // As of yet unprocessed??
L->Blocks.push_back(X);
-
+
// Add all of the predecessors of X to the end of the work stack...
TodoStack.insert(TodoStack.end(), pred_begin(X), pred_end(X));
}
}
- // Add the basic blocks that comprise this loop to the BBMap so that this
- // loop can be found for them. Also check subsidary basic blocks to see if
- // they start subloops of their own.
- //
- for (std::vector<BasicBlock*>::reverse_iterator I = L->Blocks.rbegin(),
- E = L->Blocks.rend(); I != E; ++I) {
-
- // Check to see if this block starts a new loop
+ // If there are any loops nested within this loop, create them now!
+ for (std::vector<BasicBlock*>::iterator I = L->Blocks.begin(),
+ E = L->Blocks.end(); I != E; ++I)
if (Loop *NewLoop = ConsiderForLoop(*I, DS)) {
L->SubLoops.push_back(NewLoop);
NewLoop->ParentLoop = L;
}
-
- if (BBMap.find(*I) == BBMap.end())
- BBMap.insert(std::make_pair(*I, L));
+
+
+ // Add the basic blocks that comprise this loop to the BBMap so that this
+ // loop can be found for them.
+ //
+ for (std::vector<BasicBlock*>::iterator I = L->Blocks.begin(),
+ E = L->Blocks.end(); I != E; ++I) {
+ std::map<BasicBlock*, Loop*>::iterator BBMI = BBMap.lower_bound(*I);
+ if (BBMI == BBMap.end() || BBMI->first != *I) // Not in map yet...
+ BBMap.insert(BBMI, std::make_pair(*I, L)); // Must be at this level
}
+ // Now that we know all of the blocks that make up this loop, see if there are
+ // any branches to outside of the loop... building the ExitBlocks list.
+ for (std::vector<BasicBlock*>::iterator BI = L->Blocks.begin(),
+ BE = L->Blocks.end(); BI != BE; ++BI)
+ for (succ_iterator I = succ_begin(*BI), E = succ_end(*BI); I != E; ++I)
+ if (!L->contains(*I)) // Not in current loop?
+ L->ExitBlocks.push_back(*I); // It must be an exit block...
+
return L;
}
BasicBlock *Header = getHeader();
for (pred_iterator PI = pred_begin(Header), PE = pred_end(Header);
PI != PE; ++PI)
- if (!contains(*PI)) { // If the block is not in the loop...
- if (Out) return 0; // Multiple predecessors outside the loop
+ if (!contains(*PI)) { // If the block is not in the loop...
+ if (Out && Out != *PI)
+ return 0; // Multiple predecessors outside the loop
Out = *PI;
}
+
+ // Make sure there is only one exit out of the preheader...
+ succ_iterator SI = succ_begin(Out);
+ ++SI;
+ if (SI != succ_end(Out))
+ return 0; // Multiple exits from the block, must not be a preheader.
+
// If there is exactly one preheader, return it. If there was zero, then Out
// is still null.
L = L->getParentLoop();
}
}
+
+/// changeExitBlock - This method is used to update loop information. All
+/// instances of the specified Old basic block are removed from the exit list
+/// and replaced with New.
+///
+void Loop::changeExitBlock(BasicBlock *Old, BasicBlock *New) {
+ assert(Old != New && "Cannot changeExitBlock to the same thing!");
+ assert(Old && New && "Cannot changeExitBlock to or from a null node!");
+ assert(hasExitBlock(Old) && "Old exit block not found!");
+ std::vector<BasicBlock*>::iterator
+ I = std::find(ExitBlocks.begin(), ExitBlocks.end(), Old);
+ while (I != ExitBlocks.end()) {
+ *I = New;
+ I = std::find(I+1, ExitBlocks.end(), Old);
+ }
+}
projects / oota-llvm.git / blobdiff