X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FVMCore%2FBasicBlock.cpp;h=d3df1d1d71dbd1265a6d2ca420132d5126d50ab4;hb=0f7eea5d0401a3aaff27d2fdb34044e5983db3d1;hp=b00ce51f2f71e59f9876d156d0632f99e2651013;hpb=f8485c643412dbff46fe87ea2867445169a5c28e;p=oota-llvm.git diff --git a/lib/VMCore/BasicBlock.cpp b/lib/VMCore/BasicBlock.cpp index b00ce51f2f7..d3df1d1d71d 100644 --- a/lib/VMCore/BasicBlock.cpp +++ b/lib/VMCore/BasicBlock.cpp @@ -21,33 +21,33 @@ #include "Support/LeakDetector.h" #include "SymbolTableListTraitsImpl.h" #include +using namespace llvm; + +namespace { + /// DummyInst - An instance of this class is used to mark the end of the + /// instruction list. This is not a real instruction. + struct DummyInst : public Instruction { + DummyInst() : Instruction(Type::VoidTy, OtherOpsEnd) { + // This should not be garbage monitored. + LeakDetector::removeGarbageObject(this); + } -namespace llvm { - -// DummyInst - An instance of this class is used to mark the end of the -// instruction list. This is not a real instruction. -// -struct DummyInst : public Instruction { - DummyInst() : Instruction(Type::VoidTy, OtherOpsEnd) { - // This should not be garbage monitored. - LeakDetector::removeGarbageObject(this); - } - - virtual Instruction *clone() const { - assert(0 && "Cannot clone EOL");abort(); - return 0; - } - virtual const char *getOpcodeName() const { return "*end-of-list-inst*"; } + virtual Instruction *clone() const { + assert(0 && "Cannot clone EOL");abort(); + return 0; + } + virtual const char *getOpcodeName() const { return "*end-of-list-inst*"; } - // Methods for support type inquiry through isa, cast, and dyn_cast... - static inline bool classof(const DummyInst *) { return true; } - static inline bool classof(const Instruction *I) { - return I->getOpcode() == OtherOpsEnd; - } - static inline bool classof(const Value *V) { - return isa(V) && classof(cast(V)); - } -}; + // Methods for support type inquiry through isa, cast, and dyn_cast... + static inline bool classof(const DummyInst *) { return true; } + static inline bool classof(const Instruction *I) { + return I->getOpcode() == OtherOpsEnd; + } + static inline bool classof(const Value *V) { + return isa(V) && classof(cast(V)); + } + }; +} Instruction *ilist_traits::createNode() { return new DummyInst(); @@ -61,25 +61,8 @@ iplist &ilist_traits::getList(BasicBlock *BB) { template class SymbolTableListTraits; -// BasicBlock ctor - If the function parameter is specified, the basic block is -// automatically inserted at the end of the function. -// -BasicBlock::BasicBlock(const std::string &name, Function *Parent) - : Value(Type::LabelTy, Value::BasicBlockVal, name) { - // Initialize the instlist... - InstList.setItemParent(this); - - // Make sure that we get added to a function - LeakDetector::addGarbageObject(this); - - if (Parent) - Parent->getBasicBlockList().push_back(this); -} - -/// BasicBlock ctor - If the InsertBefore parameter is specified, the basic -/// block is automatically inserted right before the specified block. -/// -BasicBlock::BasicBlock(const std::string &Name, BasicBlock *InsertBefore) +BasicBlock::BasicBlock(const std::string &Name, Function *Parent, + BasicBlock *InsertBefore) : Value(Type::LabelTy, Value::BasicBlockVal, Name) { // Initialize the instlist... InstList.setItemParent(this); @@ -88,15 +71,17 @@ BasicBlock::BasicBlock(const std::string &Name, BasicBlock *InsertBefore) LeakDetector::addGarbageObject(this); if (InsertBefore) { - assert(InsertBefore->getParent() && - "Cannot insert block before another block that is not embedded into" - " a function yet!"); - InsertBefore->getParent()->getBasicBlockList().insert(InsertBefore, this); + assert(Parent && + "Cannot insert block before another block with no function!"); + Parent->getBasicBlockList().insert(InsertBefore, this); + } else if (Parent) { + Parent->getBasicBlockList().push_back(this); } } BasicBlock::~BasicBlock() { + assert(getParent() == 0 && "BasicBlock still linked into the program!"); dropAllReferences(); InstList.clear(); } @@ -136,19 +121,6 @@ void BasicBlock::dropAllReferences() { I->dropAllReferences(); } -// hasConstantReferences() - This predicate is true if there is a -// reference to this basic block in the constant pool for this method. For -// example, if a block is reached through a switch table, that table resides -// in the constant pool, and the basic block is reference from it. -// -bool BasicBlock::hasConstantReferences() const { - for (use_const_iterator I = use_begin(), E = use_end(); I != E; ++I) - if (isa((Value*)*I)) - return true; - - return false; -} - // removePredecessor - This method is used to notify a BasicBlock that the // specified Predecessor of the block is no longer able to reach it. This is // actually not used to update the Predecessor list, but is actually used to @@ -158,17 +130,11 @@ bool BasicBlock::hasConstantReferences() const { void BasicBlock::removePredecessor(BasicBlock *Pred) { assert(find(pred_begin(this), pred_end(this), Pred) != pred_end(this) && "removePredecessor: BB is not a predecessor!"); - if (!isa(front())) return; // Quick exit. - - pred_iterator PI(pred_begin(this)), EI(pred_end(this)); - unsigned max_idx; - - // Loop over the rest of the predecessors until we run out, or until we find - // out that there are more than 2 predecessors. - for (max_idx = 0; PI != EI && max_idx < 3; ++PI, ++max_idx) /*empty*/; + PHINode *APN = dyn_cast(&front()); + if (!APN) return; // Quick exit. // If there are exactly two predecessors, then we want to nuke the PHI nodes - // altogether. We cannot do this, however if this in this case however: + // altogether. However, we cannot do this, if this in this case: // // Loop: // %x = phi [X, Loop] @@ -179,10 +145,10 @@ void BasicBlock::removePredecessor(BasicBlock *Pred) { // basic block. The only case this can happen is with a self loop, so we // check for this case explicitly now. // + unsigned max_idx = APN->getNumIncomingValues(); assert(max_idx != 0 && "PHI Node in block with 0 predecessors!?!?!"); if (max_idx == 2) { - PI = pred_begin(this); - BasicBlock *Other = *PI == Pred ? *++PI : *PI; + BasicBlock *Other = APN->getIncomingBlock(APN->getIncomingBlock(0) == Pred); // Disable PHI elimination! if (this == Other) max_idx = 3; @@ -209,7 +175,8 @@ void BasicBlock::removePredecessor(BasicBlock *Pred) { } else { // Okay, now we know that we need to remove predecessor #pred_idx from all // PHI nodes. Iterate over each PHI node fixing them up - for (iterator II = begin(); PHINode *PN = dyn_cast(II); ++II) + PHINode *PN; + for (iterator II = begin(); (PN = dyn_cast(II)); ++II) PN->removeIncomingValue(Pred); } } @@ -231,19 +198,14 @@ BasicBlock *BasicBlock::splitBasicBlock(iterator I, const std::string &BBName) { assert(I != InstList.end() && "Trying to get me to create degenerate basic block!"); - BasicBlock *New = new BasicBlock(BBName, getParent()); + BasicBlock *New = new BasicBlock(BBName, getParent(), getNext()); - // Go from the end of the basic block through to the iterator pointer, moving - // to the new basic block... - Instruction *Inst = 0; - do { - iterator EndIt = end(); - Inst = InstList.remove(--EndIt); // Remove from end - New->InstList.push_front(Inst); // Add to front - } while (Inst != &*I); // Loop until we move the specified instruction. + // Move all of the specified instructions from the original basic block into + // the new basic block. + New->getInstList().splice(New->end(), this->getInstList(), I, end()); // Add a branch instruction to the newly formed basic block. - new BranchInst(New, 0, 0, this); + new BranchInst(New, this); // Now we must loop through all of the successors of the New block (which // _were_ the successors of the 'this' block), and update any PHI nodes in @@ -254,8 +216,9 @@ BasicBlock *BasicBlock::splitBasicBlock(iterator I, const std::string &BBName) { // Loop over any phi nodes in the basic block, updating the BB field of // incoming values... BasicBlock *Successor = *I; + PHINode *PN; for (BasicBlock::iterator II = Successor->begin(); - PHINode *PN = dyn_cast(II); ++II) { + (PN = dyn_cast(II)); ++II) { int IDX = PN->getBasicBlockIndex(this); while (IDX != -1) { PN->setIncomingBlock((unsigned)IDX, New); @@ -265,5 +228,3 @@ BasicBlock *BasicBlock::splitBasicBlock(iterator I, const std::string &BBName) { } return New; } - -} // End llvm namespace