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-rw-r--r--lib/Analysis/LoopInfo.cpp396
1 files changed, 0 insertions, 396 deletions
diff --git a/lib/Analysis/LoopInfo.cpp b/lib/Analysis/LoopInfo.cpp
index 09dca27958..20ca892997 100644
--- a/lib/Analysis/LoopInfo.cpp
+++ b/lib/Analysis/LoopInfo.cpp
@@ -34,69 +34,9 @@ X("loops", "Natural Loop Construction", true);
//===----------------------------------------------------------------------===//
// Loop implementation
//
-bool Loop::contains(const BasicBlock *BB) const {
- return std::find(Blocks.begin(), Blocks.end(), BB) != Blocks.end();
-}
-
-bool Loop::isLoopExit(const BasicBlock *BB) const {
- for (succ_const_iterator SI = succ_begin(BB), SE = succ_end(BB);
- SI != SE; ++SI) {
- if (!contains(*SI))
- return true;
- }
- return false;
-}
/// getNumBackEdges - Calculate the number of back edges to the loop header.
///
-unsigned Loop::getNumBackEdges() const {
- unsigned NumBackEdges = 0;
- BasicBlock *H = getHeader();
-
- for (pred_iterator I = pred_begin(H), E = pred_end(H); I != E; ++I)
- if (contains(*I))
- ++NumBackEdges;
-
- return NumBackEdges;
-}
-
-/// isLoopInvariant - Return true if the specified value is loop invariant
-///
-bool Loop::isLoopInvariant(Value *V) const {
- if (Instruction *I = dyn_cast<Instruction>(V))
- return !contains(I->getParent());
- return true; // All non-instructions are loop invariant
-}
-
-void Loop::print(std::ostream &OS, unsigned Depth) const {
- OS << std::string(Depth*2, ' ') << "Loop Containing: ";
-
- for (unsigned i = 0; i < getBlocks().size(); ++i) {
- if (i) OS << ",";
- WriteAsOperand(OS, getBlocks()[i], false);
- }
- OS << "\n";
-
- for (iterator I = begin(), E = end(); I != E; ++I)
- (*I)->print(OS, Depth+2);
-}
-
-/// verifyLoop - Verify loop structure
-void Loop::verifyLoop() const {
-#ifndef NDEBUG
- assert (getHeader() && "Loop header is missing");
- assert (getLoopPreheader() && "Loop preheader is missing");
- assert (getLoopLatch() && "Loop latch is missing");
- for (std::vector<Loop*>::const_iterator I = SubLoops.begin(), E = SubLoops.end();
- I != E; ++I)
- (*I)->verifyLoop();
-#endif
-}
-
-void Loop::dump() const {
- print(cerr);
-}
-
//===----------------------------------------------------------------------===//
// LoopInfo implementation
@@ -341,341 +281,5 @@ void LoopInfo::removeBlock(BasicBlock *BB) {
}
}
-
-//===----------------------------------------------------------------------===//
-// APIs for simple analysis of the loop.
-//
-
-/// getExitingBlocks - Return all blocks inside the loop that have successors
-/// outside of the loop. These are the blocks _inside of the current loop_
-/// which branch out. The returned list is always unique.
-///
-void Loop::getExitingBlocks(SmallVectorImpl<BasicBlock*> &ExitingBlocks) const {
- // Sort the blocks vector so that we can use binary search to do quick
- // lookups.
- SmallVector<BasicBlock*, 128> LoopBBs(block_begin(), block_end());
- std::sort(LoopBBs.begin(), LoopBBs.end());
-
- for (std::vector<BasicBlock*>::const_iterator BI = Blocks.begin(),
- BE = Blocks.end(); BI != BE; ++BI)
- for (succ_iterator I = succ_begin(*BI), E = succ_end(*BI); I != E; ++I)
- if (!std::binary_search(LoopBBs.begin(), LoopBBs.end(), *I)) {
- // Not in current loop? It must be an exit block.
- ExitingBlocks.push_back(*BI);
- break;
- }
-}
-
-/// getExitBlocks - Return all of the successor blocks of this loop. These
-/// are the blocks _outside of the current loop_ which are branched to.
-///
-void Loop::getExitBlocks(SmallVectorImpl<BasicBlock*> &ExitBlocks) const {
- // Sort the blocks vector so that we can use binary search to do quick
- // lookups.
- SmallVector<BasicBlock*, 128> LoopBBs(block_begin(), block_end());
- std::sort(LoopBBs.begin(), LoopBBs.end());
-
- for (std::vector<BasicBlock*>::const_iterator BI = Blocks.begin(),
- BE = Blocks.end(); BI != BE; ++BI)
- for (succ_iterator I = succ_begin(*BI), E = succ_end(*BI); I != E; ++I)
- if (!std::binary_search(LoopBBs.begin(), LoopBBs.end(), *I))
- // Not in current loop? It must be an exit block.
- ExitBlocks.push_back(*I);
-}
-
-/// getUniqueExitBlocks - Return all unique successor blocks of this loop. These
-/// are the blocks _outside of the current loop_ which are branched to. This
-/// assumes that loop is in canonical form.
-//
-void Loop::getUniqueExitBlocks(SmallVectorImpl<BasicBlock*> &ExitBlocks) const {
- // Sort the blocks vector so that we can use binary search to do quick
- // lookups.
- SmallVector<BasicBlock*, 128> LoopBBs(block_begin(), block_end());
- std::sort(LoopBBs.begin(), LoopBBs.end());
-
- std::vector<BasicBlock*> switchExitBlocks;
-
- for (std::vector<BasicBlock*>::const_iterator BI = Blocks.begin(),
- BE = Blocks.end(); BI != BE; ++BI) {
-
- BasicBlock *current = *BI;
- switchExitBlocks.clear();
-
- for (succ_iterator I = succ_begin(*BI), E = succ_end(*BI); I != E; ++I) {
- if (std::binary_search(LoopBBs.begin(), LoopBBs.end(), *I))
- // If block is inside the loop then it is not a exit block.
- continue;
-
- pred_iterator PI = pred_begin(*I);
- BasicBlock *firstPred = *PI;
-
- // If current basic block is this exit block's first predecessor
- // then only insert exit block in to the output ExitBlocks vector.
- // This ensures that same exit block is not inserted twice into
- // ExitBlocks vector.
- if (current != firstPred)
- continue;
-
- // If a terminator has more then two successors, for example SwitchInst,
- // then it is possible that there are multiple edges from current block
- // to one exit block.
- if (current->getTerminator()->getNumSuccessors() <= 2) {
- ExitBlocks.push_back(*I);
- continue;
- }
-
- // In case of multiple edges from current block to exit block, collect
- // only one edge in ExitBlocks. Use switchExitBlocks to keep track of
- // duplicate edges.
- if (std::find(switchExitBlocks.begin(), switchExitBlocks.end(), *I)
- == switchExitBlocks.end()) {
- switchExitBlocks.push_back(*I);
- ExitBlocks.push_back(*I);
- }
- }
- }
-}
-
-
-/// getLoopPreheader - If there is a preheader for this loop, return it. A
-/// loop has a preheader if there is only one edge to the header of the loop
-/// from outside of the loop. If this is the case, the block branching to the
-/// header of the loop is the preheader node.
-///
-/// This method returns null if there is no preheader for the loop.
-///
-BasicBlock *Loop::getLoopPreheader() const {
- // Keep track of nodes outside the loop branching to the header...
- BasicBlock *Out = 0;
-
- // Loop over the predecessors of the header node...
- 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 && Out != *PI)
- return 0; // Multiple predecessors outside the loop
- Out = *PI;
- }
-
- // Make sure there is only one exit out of the preheader.
- assert(Out && "Header of loop has no predecessors from outside loop?");
- 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.
- return Out;
-}
-
-/// getLoopLatch - If there is a latch block for this loop, return it. A
-/// latch block is the canonical backedge for a loop. A loop header in normal
-/// form has two edges into it: one from a preheader and one from a latch
-/// block.
-BasicBlock *Loop::getLoopLatch() const {
- BasicBlock *Header = getHeader();
- pred_iterator PI = pred_begin(Header), PE = pred_end(Header);
- if (PI == PE) return 0; // no preds?
-
- BasicBlock *Latch = 0;
- if (contains(*PI))
- Latch = *PI;
- ++PI;
- if (PI == PE) return 0; // only one pred?
-
- if (contains(*PI)) {
- if (Latch) return 0; // multiple backedges
- Latch = *PI;
- }
- ++PI;
- if (PI != PE) return 0; // more than two preds
-
- return Latch;
-}
-
-/// getCanonicalInductionVariable - Check to see if the loop has a canonical
-/// induction variable: an integer recurrence that starts at 0 and increments by
-/// one each time through the loop. If so, return the phi node that corresponds
-/// to it.
-///
-PHINode *Loop::getCanonicalInductionVariable() const {
- BasicBlock *H = getHeader();
-
- BasicBlock *Incoming = 0, *Backedge = 0;
- pred_iterator PI = pred_begin(H);
- assert(PI != pred_end(H) && "Loop must have at least one backedge!");
- Backedge = *PI++;
- if (PI == pred_end(H)) return 0; // dead loop
- Incoming = *PI++;
- if (PI != pred_end(H)) return 0; // multiple backedges?
-
- if (contains(Incoming)) {
- if (contains(Backedge))
- return 0;
- std::swap(Incoming, Backedge);
- } else if (!contains(Backedge))
- return 0;
-
- // Loop over all of the PHI nodes, looking for a canonical indvar.
- for (BasicBlock::iterator I = H->begin(); isa<PHINode>(I); ++I) {
- PHINode *PN = cast<PHINode>(I);
- if (Instruction *Inc =
- dyn_cast<Instruction>(PN->getIncomingValueForBlock(Backedge)))
- if (Inc->getOpcode() == Instruction::Add && Inc->getOperand(0) == PN)
- if (ConstantInt *CI = dyn_cast<ConstantInt>(Inc->getOperand(1)))
- if (CI->equalsInt(1))
- return PN;
- }
- return 0;
-}
-
-/// getCanonicalInductionVariableIncrement - Return the LLVM value that holds
-/// the canonical induction variable value for the "next" iteration of the loop.
-/// This always succeeds if getCanonicalInductionVariable succeeds.
-///
-Instruction *Loop::getCanonicalInductionVariableIncrement() const {
- if (PHINode *PN = getCanonicalInductionVariable()) {
- bool P1InLoop = contains(PN->getIncomingBlock(1));
- return cast<Instruction>(PN->getIncomingValue(P1InLoop));
- }
- return 0;
-}
-
-/// getTripCount - Return a loop-invariant LLVM value indicating the number of
-/// times the loop will be executed. Note that this means that the backedge of
-/// the loop executes N-1 times. If the trip-count cannot be determined, this
-/// returns null.
-///
-Value *Loop::getTripCount() const {
- // Canonical loops will end with a 'cmp ne I, V', where I is the incremented
- // canonical induction variable and V is the trip count of the loop.
- Instruction *Inc = getCanonicalInductionVariableIncrement();
- if (Inc == 0) return 0;
- PHINode *IV = cast<PHINode>(Inc->getOperand(0));
-
- BasicBlock *BackedgeBlock =
- IV->getIncomingBlock(contains(IV->getIncomingBlock(1)));
-
- if (BranchInst *BI = dyn_cast<BranchInst>(BackedgeBlock->getTerminator()))
- if (BI->isConditional()) {
- if (ICmpInst *ICI = dyn_cast<ICmpInst>(BI->getCondition())) {
- if (ICI->getOperand(0) == Inc)
- if (BI->getSuccessor(0) == getHeader()) {
- if (ICI->getPredicate() == ICmpInst::ICMP_NE)
- return ICI->getOperand(1);
- } else if (ICI->getPredicate() == ICmpInst::ICMP_EQ) {
- return ICI->getOperand(1);
- }
- }
- }
-
- return 0;
-}
-
-/// isLCSSAForm - Return true if the Loop is in LCSSA form
-bool Loop::isLCSSAForm() const {
- // Sort the blocks vector so that we can use binary search to do quick
- // lookups.
- SmallPtrSet<BasicBlock*, 16> LoopBBs(block_begin(), block_end());
-
- for (block_iterator BI = block_begin(), E = block_end(); BI != E; ++BI) {
- BasicBlock *BB = *BI;
- for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
- for (Value::use_iterator UI = I->use_begin(), E = I->use_end(); UI != E;
- ++UI) {
- BasicBlock *UserBB = cast<Instruction>(*UI)->getParent();
- if (PHINode *P = dyn_cast<PHINode>(*UI)) {
- unsigned OperandNo = UI.getOperandNo();
- UserBB = P->getIncomingBlock(OperandNo/2);
- }
-
- // Check the current block, as a fast-path. Most values are used in the
- // same block they are defined in.
- if (UserBB != BB && !LoopBBs.count(UserBB))
- return false;
- }
- }
-
- return true;
-}
-
-//===-------------------------------------------------------------------===//
-// APIs for updating loop information after changing the CFG
-//
-
-/// addBasicBlockToLoop - This function is used by other analyses to update loop
-/// information. NewBB is set to be a new member of the current loop. Because
-/// of this, it is added as a member of all parent loops, and is added to the
-/// specified LoopInfo object as being in the current basic block. It is not
-/// valid to replace the loop header with this method.
-///
-void Loop::addBasicBlockToLoop(BasicBlock *NewBB, LoopInfo &LI) {
- assert((Blocks.empty() || LI[getHeader()] == this) &&
- "Incorrect LI specified for this loop!");
- assert(NewBB && "Cannot add a null basic block to the loop!");
- assert(LI[NewBB] == 0 && "BasicBlock already in the loop!");
-
- // Add the loop mapping to the LoopInfo object...
- LI.BBMap[NewBB] = this;
-
- // Add the basic block to this loop and all parent loops...
- Loop *L = this;
- while (L) {
- L->Blocks.push_back(NewBB);
- L = L->getParentLoop();
- }
-}
-
-/// replaceChildLoopWith - This is used when splitting loops up. It replaces
-/// the OldChild entry in our children list with NewChild, and updates the
-/// parent pointers of the two loops as appropriate.
-void Loop::replaceChildLoopWith(Loop *OldChild, Loop *NewChild) {
- assert(OldChild->ParentLoop == this && "This loop is already broken!");
- assert(NewChild->ParentLoop == 0 && "NewChild already has a parent!");
- std::vector<Loop*>::iterator I = std::find(SubLoops.begin(), SubLoops.end(),
- OldChild);
- assert(I != SubLoops.end() && "OldChild not in loop!");
- *I = NewChild;
- OldChild->ParentLoop = 0;
- NewChild->ParentLoop = this;
-}
-
-/// addChildLoop - Add the specified loop to be a child of this loop.
-///
-void Loop::addChildLoop(Loop *NewChild) {
- assert(NewChild->ParentLoop == 0 && "NewChild already has a parent!");
- NewChild->ParentLoop = this;
- SubLoops.push_back(NewChild);
-}
-
-template<typename T>
-static void RemoveFromVector(std::vector<T*> &V, T *N) {
- typename std::vector<T*>::iterator I = std::find(V.begin(), V.end(), N);
- assert(I != V.end() && "N is not in this list!");
- V.erase(I);
-}
-
-/// removeChildLoop - This removes the specified child from being a subloop of
-/// this loop. The loop is not deleted, as it will presumably be inserted
-/// into another loop.
-Loop *Loop::removeChildLoop(iterator I) {
- assert(I != SubLoops.end() && "Cannot remove end iterator!");
- Loop *Child = *I;
- assert(Child->ParentLoop == this && "Child is not a child of this loop!");
- SubLoops.erase(SubLoops.begin()+(I-begin()));
- Child->ParentLoop = 0;
- return Child;
-}
-
-
-/// removeBlockFromLoop - This removes the specified basic block from the
-/// current loop, updating the Blocks and ExitBlocks lists as appropriate. This
-/// does not update the mapping in the LoopInfo class.
-void Loop::removeBlockFromLoop(BasicBlock *BB) {
- RemoveFromVector(Blocks, BB);
-}
-
// Ensure this file gets linked when LoopInfo.h is used.
DEFINING_FILE_FOR(LoopInfo)
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