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-rw-r--r--lib/CodeGen/MachineBasicBlock.cpp372
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diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp
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+//===-- 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 <algorithm>
+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;
+}
+
+/// 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<MachineBasicBlock>::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<MachineBasicBlock>::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<MachineInstr>::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<MachineInstr>::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<MachineInstr>::transferNodesFromList(
+ ilist_traits<MachineInstr>& 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<MachineInstr>::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(std::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 {
+ 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";
+
+ 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) {
+ OS << "\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);
+}
+
+void MachineBasicBlock::removePredecessor(MachineBasicBlock *pred) {
+ std::vector<MachineBasicBlock *>::iterator I =
+ std::find(Predecessors.begin(), Predecessors.end(), pred);
+ assert(I != Predecessors.end() && "Pred is not a predecessor of this block!");
+ Predecessors.erase(I);
+}
+
+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);
+ }
+ while(!fromMBB->succ_empty())
+ fromMBB->removeSuccessor(fromMBB->succ_begin());
+}
+
+bool MachineBasicBlock::isSuccessor(const MachineBasicBlock *MBB) const {
+ std::vector<MachineBasicBlock *>::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;
+}
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