X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FMachineBasicBlock.cpp;h=b30a3fcf3004d18bcc157d3304464b5f73b3d9b1;hb=a6b677d209013d82b03fa8da937296b6faae7de0;hp=666d5477b3a8e34f55e60361a665f556a857fb24;hpb=55291ead559c902e46ddcebad50dbfefe50ec2d6;p=oota-llvm.git diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp index 666d5477b3a..b30a3fcf300 100644 --- a/lib/CodeGen/MachineBasicBlock.cpp +++ b/lib/CodeGen/MachineBasicBlock.cpp @@ -1,23 +1,384 @@ -//===-- MachineBasicBlock.cpp ---------------------------------------------===// -// +//===-- llvm/CodeGen/MachineBasicBlock.cpp ----------------------*- C++ -*-===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// // Collect the sequence of machine instructions for a basic block. // //===----------------------------------------------------------------------===// #include "llvm/CodeGen/MachineBasicBlock.h" +#include "llvm/BasicBlock.h" +#include "llvm/CodeGen/MachineFunction.h" +#include "llvm/Target/TargetRegisterInfo.h" +#include "llvm/Target/TargetData.h" +#include "llvm/Target/TargetInstrDesc.h" +#include "llvm/Target/TargetMachine.h" +#include "llvm/Support/LeakDetector.h" +#include "llvm/Support/raw_ostream.h" +#include +using namespace llvm; + +MachineBasicBlock::MachineBasicBlock(MachineFunction &mf, const BasicBlock *bb) + : BB(bb), Number(-1), xParent(&mf), Alignment(0), IsLandingPad(false) { + Insts.Parent = this; +} + +MachineBasicBlock::~MachineBasicBlock() { + LeakDetector::removeGarbageObject(this); +} + +std::ostream& llvm::operator<<(std::ostream &OS, const MachineBasicBlock &MBB) { + MBB.print(OS); + return OS; +} +raw_ostream& llvm::operator<<(raw_ostream &OS, const MachineBasicBlock &MBB) { + MBB.print(OS); + return OS; +} + +/// addNodeToList (MBB) - When an MBB is added to an MF, we need to update the +/// parent pointer of the MBB, the MBB numbering, and any instructions in the +/// MBB to be on the right operand list for registers. +/// +/// MBBs start out as #-1. When a MBB is added to a MachineFunction, it +/// gets the next available unique MBB number. If it is removed from a +/// MachineFunction, it goes back to being #-1. +void ilist_traits::addNodeToList(MachineBasicBlock* N) { + MachineFunction &MF = *N->getParent(); + N->Number = MF.addToMBBNumbering(N); + + // Make sure the instructions have their operands in the reginfo lists. + MachineRegisterInfo &RegInfo = MF.getRegInfo(); + for (MachineBasicBlock::iterator I = N->begin(), E = N->end(); I != E; ++I) + I->AddRegOperandsToUseLists(RegInfo); + + LeakDetector::removeGarbageObject(N); +} + +void ilist_traits::removeNodeFromList(MachineBasicBlock* N) { + N->getParent()->removeFromMBBNumbering(N->Number); + N->Number = -1; + LeakDetector::addGarbageObject(N); +} + + +/// addNodeToList (MI) - When we add an instruction to a basic block +/// list, we update its parent pointer and add its operands from reg use/def +/// lists if appropriate. +void ilist_traits::addNodeToList(MachineInstr* N) { + assert(N->getParent() == 0 && "machine instruction already in a basic block"); + N->setParent(Parent); + + // Add the instruction's register operands to their corresponding + // use/def lists. + MachineFunction *MF = Parent->getParent(); + N->AddRegOperandsToUseLists(MF->getRegInfo()); + + LeakDetector::removeGarbageObject(N); +} + +/// removeNodeFromList (MI) - When we remove an instruction from a basic block +/// list, we update its parent pointer and remove its operands from reg use/def +/// lists if appropriate. +void ilist_traits::removeNodeFromList(MachineInstr* N) { + assert(N->getParent() != 0 && "machine instruction not in a basic block"); + + // Remove from the use/def lists. + N->RemoveRegOperandsFromUseLists(); + + N->setParent(0); + + LeakDetector::addGarbageObject(N); +} + +/// transferNodesFromList (MI) - When moving a range of instructions from one +/// MBB list to another, we need to update the parent pointers and the use/def +/// lists. +void ilist_traits::transferNodesFromList( + ilist_traits& fromList, + MachineBasicBlock::iterator first, + MachineBasicBlock::iterator last) { + assert(Parent->getParent() == fromList.Parent->getParent() && + "MachineInstr parent mismatch!"); + + // Splice within the same MBB -> no change. + if (Parent == fromList.Parent) return; + + // If splicing between two blocks within the same function, just update the + // parent pointers. + for (; first != last; ++first) + first->setParent(Parent); +} + +void ilist_traits::deleteNode(MachineInstr* MI) { + assert(!MI->getParent() && "MI is still in a block!"); + Parent->getParent()->DeleteMachineInstr(MI); +} + +MachineBasicBlock::iterator MachineBasicBlock::getFirstTerminator() { + iterator I = end(); + while (I != begin() && (--I)->getDesc().isTerminator()) + ; /*noop */ + if (I != end() && !I->getDesc().isTerminator()) ++I; + return I; +} + +bool +MachineBasicBlock::isOnlyReachableByFallthrough() const { + return !isLandingPad() && + !pred_empty() && + next(pred_begin()) == pred_end() && + (*pred_begin())->isLayoutSuccessor(this) && + ((*pred_begin())->empty() || + !(*pred_begin())->back().getDesc().isBarrier()); +} + +void MachineBasicBlock::dump() const { + print(*cerr.stream()); +} + +static inline void OutputReg(raw_ostream &os, unsigned RegNo, + const TargetRegisterInfo *TRI = 0) { + if (!RegNo || TargetRegisterInfo::isPhysicalRegister(RegNo)) { + if (TRI) + os << " %" << TRI->get(RegNo).Name; + else + os << " %mreg(" << RegNo << ")"; + } else + os << " %reg" << RegNo; +} + +void MachineBasicBlock::print(std::ostream &OS, + const PrefixPrinter &prefix) const { + raw_os_ostream RawOS(OS); + print(RawOS, prefix); +} + +void MachineBasicBlock::print(raw_ostream &OS, + const PrefixPrinter &prefix) const { + const MachineFunction *MF = getParent(); + if(!MF) { + OS << "Can't print out MachineBasicBlock because parent MachineFunction" + << " is null\n"; + return; + } + + const BasicBlock *LBB = getBasicBlock(); + OS << "\n"; + if (LBB) OS << LBB->getName() << ": "; + OS << (const void*)this + << ", LLVM BB @" << (const void*) LBB << ", ID#" << getNumber(); + if (Alignment) OS << ", Alignment " << Alignment; + if (isLandingPad()) OS << ", EH LANDING PAD"; + OS << ":\n"; -AnnotationID MCFBB_AID( - AnnotationManager::getID("CodeGen::MachineBasicBlock")); + const TargetRegisterInfo *TRI = MF->getTarget().getRegisterInfo(); + if (!livein_empty()) { + OS << "Live Ins:"; + for (const_livein_iterator I = livein_begin(),E = livein_end(); I != E; ++I) + OutputReg(OS, *I, TRI); + OS << "\n"; + } + // Print the preds of this block according to the CFG. + if (!pred_empty()) { + OS << " Predecessors according to CFG:"; + for (const_pred_iterator PI = pred_begin(), E = pred_end(); PI != E; ++PI) + OS << " " << *PI << " (#" << (*PI)->getNumber() << ")"; + OS << "\n"; + } + + for (const_iterator I = begin(); I != end(); ++I) { + prefix(OS, *I) << "\t"; + I->print(OS, &getParent()->getTarget()); + } + + // Print the successors of this block according to the CFG. + if (!succ_empty()) { + OS << " Successors according to CFG:"; + for (const_succ_iterator SI = succ_begin(), E = succ_end(); SI != E; ++SI) + OS << " " << *SI << " (#" << (*SI)->getNumber() << ")"; + OS << "\n"; + } +} + +void MachineBasicBlock::removeLiveIn(unsigned Reg) { + livein_iterator I = std::find(livein_begin(), livein_end(), Reg); + assert(I != livein_end() && "Not a live in!"); + LiveIns.erase(I); +} + +bool MachineBasicBlock::isLiveIn(unsigned Reg) const { + const_livein_iterator I = std::find(livein_begin(), livein_end(), Reg); + return I != livein_end(); +} + +void MachineBasicBlock::moveBefore(MachineBasicBlock *NewAfter) { + getParent()->splice(NewAfter, this); +} + +void MachineBasicBlock::moveAfter(MachineBasicBlock *NewBefore) { + MachineFunction::iterator BBI = NewBefore; + getParent()->splice(++BBI, this); +} + + +void MachineBasicBlock::addSuccessor(MachineBasicBlock *succ) { + Successors.push_back(succ); + succ->addPredecessor(this); +} + +void MachineBasicBlock::removeSuccessor(MachineBasicBlock *succ) { + succ->removePredecessor(this); + succ_iterator I = std::find(Successors.begin(), Successors.end(), succ); + assert(I != Successors.end() && "Not a current successor!"); + Successors.erase(I); +} + +MachineBasicBlock::succ_iterator +MachineBasicBlock::removeSuccessor(succ_iterator I) { + assert(I != Successors.end() && "Not a current successor!"); + (*I)->removePredecessor(this); + return Successors.erase(I); +} + +void MachineBasicBlock::addPredecessor(MachineBasicBlock *pred) { + Predecessors.push_back(pred); +} -static Annotation *CreateMCFBB(AnnotationID AID, const Annotable *, void *) { - assert(AID == MCFBB_AID); - return new MachineBasicBlock(); // Invoke constructor! +void MachineBasicBlock::removePredecessor(MachineBasicBlock *pred) { + std::vector::iterator I = + std::find(Predecessors.begin(), Predecessors.end(), pred); + assert(I != Predecessors.end() && "Pred is not a predecessor of this block!"); + Predecessors.erase(I); } -// Register the annotation with the annotation factory -static struct MCFBBInitializer { - MCFBBInitializer() { - AnnotationManager::registerAnnotationFactory(MCFBB_AID, &CreateMCFBB); +void MachineBasicBlock::transferSuccessors(MachineBasicBlock *fromMBB) +{ + if (this == fromMBB) + return; + + for(MachineBasicBlock::succ_iterator iter = fromMBB->succ_begin(), + end = fromMBB->succ_end(); iter != end; ++iter) { + addSuccessor(*iter); } -} RegisterCreateMCFBB; + while(!fromMBB->succ_empty()) + fromMBB->removeSuccessor(fromMBB->succ_begin()); +} + +bool MachineBasicBlock::isSuccessor(const MachineBasicBlock *MBB) const { + std::vector::const_iterator I = + std::find(Successors.begin(), Successors.end(), MBB); + return I != Successors.end(); +} + +bool MachineBasicBlock::isLayoutSuccessor(const MachineBasicBlock *MBB) const { + MachineFunction::const_iterator I(this); + return next(I) == MachineFunction::const_iterator(MBB); +} + +/// removeFromParent - This method unlinks 'this' from the containing function, +/// and returns it, but does not delete it. +MachineBasicBlock *MachineBasicBlock::removeFromParent() { + assert(getParent() && "Not embedded in a function!"); + getParent()->remove(this); + return this; +} + + +/// eraseFromParent - This method unlinks 'this' from the containing function, +/// and deletes it. +void MachineBasicBlock::eraseFromParent() { + assert(getParent() && "Not embedded in a function!"); + getParent()->erase(this); +} + +/// ReplaceUsesOfBlockWith - Given a machine basic block that branched to +/// 'Old', change the code and CFG so that it branches to 'New' instead. +void MachineBasicBlock::ReplaceUsesOfBlockWith(MachineBasicBlock *Old, + MachineBasicBlock *New) { + assert(Old != New && "Cannot replace self with self!"); + + MachineBasicBlock::iterator I = end(); + while (I != begin()) { + --I; + if (!I->getDesc().isTerminator()) break; + + // Scan the operands of this machine instruction, replacing any uses of Old + // with New. + for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) + if (I->getOperand(i).isMBB() && + I->getOperand(i).getMBB() == Old) + I->getOperand(i).setMBB(New); + } + + // Update the successor information. + removeSuccessor(Old); + addSuccessor(New); +} + +/// CorrectExtraCFGEdges - Various pieces of code can cause excess edges in the +/// CFG to be inserted. If we have proven that MBB can only branch to DestA and +/// DestB, remove any other MBB successors from the CFG. DestA and DestB can +/// be null. +/// Besides DestA and DestB, retain other edges leading to LandingPads +/// (currently there can be only one; we don't check or require that here). +/// Note it is possible that DestA and/or DestB are LandingPads. +bool MachineBasicBlock::CorrectExtraCFGEdges(MachineBasicBlock *DestA, + MachineBasicBlock *DestB, + bool isCond) { + bool MadeChange = false; + bool AddedFallThrough = false; + + MachineFunction::iterator FallThru = next(MachineFunction::iterator(this)); + + // If this block ends with a conditional branch that falls through to its + // successor, set DestB as the successor. + if (isCond) { + if (DestB == 0 && FallThru != getParent()->end()) { + DestB = FallThru; + AddedFallThrough = true; + } + } else { + // If this is an unconditional branch with no explicit dest, it must just be + // a fallthrough into DestB. + if (DestA == 0 && FallThru != getParent()->end()) { + DestA = FallThru; + AddedFallThrough = true; + } + } + + MachineBasicBlock::succ_iterator SI = succ_begin(); + MachineBasicBlock *OrigDestA = DestA, *OrigDestB = DestB; + while (SI != succ_end()) { + if (*SI == DestA && DestA == DestB) { + DestA = DestB = 0; + ++SI; + } else if (*SI == DestA) { + DestA = 0; + ++SI; + } else if (*SI == DestB) { + DestB = 0; + ++SI; + } else if ((*SI)->isLandingPad() && + *SI!=OrigDestA && *SI!=OrigDestB) { + ++SI; + } else { + // Otherwise, this is a superfluous edge, remove it. + SI = removeSuccessor(SI); + MadeChange = true; + } + } + if (!AddedFallThrough) { + assert(DestA == 0 && DestB == 0 && + "MachineCFG is missing edges!"); + } else if (isCond) { + assert(DestA == 0 && "MachineCFG is missing edges!"); + } + return MadeChange; +}