path: root/lib/CodeGen/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/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/Assembly/Writer.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/LiveVariables.h"
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineLoopInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/SlotIndexes.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/LeakDetector.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include <algorithm>
using namespace llvm;

MachineBasicBlock::MachineBasicBlock(MachineFunction &mf, const BasicBlock *bb)
  : BB(bb), Number(-1), xParent(&mf), Alignment(0), IsLandingPad(false),
    AddressTaken(false), CachedMCSymbol(NULL) {
  Insts.Parent = this;
}

MachineBasicBlock::~MachineBasicBlock() {
  LeakDetector::removeGarbageObject(this);
}

/// getSymbol - Return the MCSymbol for this basic block.
///
MCSymbol *MachineBasicBlock::getSymbol() const {
  if (!CachedMCSymbol) {
    const MachineFunction *MF = getParent();
    MCContext &Ctx = MF->getContext();
    const char *Prefix = Ctx.getAsmInfo().getPrivateGlobalPrefix();
    CachedMCSymbol = Ctx.GetOrCreateSymbol(Twine(Prefix) + "BB" +
                                           Twine(MF->getFunctionNumber()) +
                                           "_" + Twine(getNumber()));
  }

  return CachedMCSymbol;
}


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<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::instr_iterator
         I = N->instr_begin(), E = N->instr_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