1 files changed, 0 insertions, 809 deletions

diff --git a/contrib/llvm/lib/CodeGen/LiveVariables.cpp b/contrib/llvm/lib/CodeGen/LiveVariables.cpp
deleted file mode 100644
index aaff982ef1b0..000000000000
--- a/contrib/llvm/lib/CodeGen/LiveVariables.cpp
+++ /dev/null
@@ -1,809 +0,0 @@
-//===-- LiveVariables.cpp - Live Variable Analysis for Machine Code -------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements the LiveVariable analysis pass.  For each machine
-// instruction in the function, this pass calculates the set of registers that
-// are immediately dead after the instruction (i.e., the instruction calculates
-// the value, but it is never used) and the set of registers that are used by
-// the instruction, but are never used after the instruction (i.e., they are
-// killed).
-//
-// This class computes live variables using a sparse implementation based on
-// the machine code SSA form.  This class computes live variable information for
-// each virtual and _register allocatable_ physical register in a function.  It
-// uses the dominance properties of SSA form to efficiently compute live
-// variables for virtual registers, and assumes that physical registers are only
-// live within a single basic block (allowing it to do a single local analysis
-// to resolve physical register lifetimes in each basic block).  If a physical
-// register is not register allocatable, it is not tracked.  This is useful for
-// things like the stack pointer and condition codes.
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/CodeGen/LiveVariables.h"
-#include "llvm/ADT/DepthFirstIterator.h"
-#include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/ADT/SmallSet.h"
-#include "llvm/CodeGen/MachineInstr.h"
-#include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/CodeGen/Passes.h"
-#include "llvm/Config/llvm-config.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/ErrorHandling.h"
-#include "llvm/Support/raw_ostream.h"
-#include <algorithm>
-using namespace llvm;
-
-char LiveVariables::ID = 0;
-char &llvm::LiveVariablesID = LiveVariables::ID;
-INITIALIZE_PASS_BEGIN(LiveVariables, "livevars",
-                "Live Variable Analysis", false, false)
-INITIALIZE_PASS_DEPENDENCY(UnreachableMachineBlockElim)
-INITIALIZE_PASS_END(LiveVariables, "livevars",
-                "Live Variable Analysis", false, false)
-
-
-void LiveVariables::getAnalysisUsage(AnalysisUsage &AU) const {
-  AU.addRequiredID(UnreachableMachineBlockElimID);
-  AU.setPreservesAll();
-  MachineFunctionPass::getAnalysisUsage(AU);
-}
-
-MachineInstr *
-LiveVariables::VarInfo::findKill(const MachineBasicBlock *MBB) const {
-  for (unsigned i = 0, e = Kills.size(); i != e; ++i)
-    if (Kills[i]->getParent() == MBB)
-      return Kills[i];
-  return nullptr;
-}
-
-#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
-LLVM_DUMP_METHOD void LiveVariables::VarInfo::dump() const {
-  dbgs() << "  Alive in blocks: ";
-  for (SparseBitVector<>::iterator I = AliveBlocks.begin(),
-           E = AliveBlocks.end(); I != E; ++I)
-    dbgs() << *I << ", ";
-  dbgs() << "\n  Killed by:";
-  if (Kills.empty())
-    dbgs() << " No instructions.\n";
-  else {
-    for (unsigned i = 0, e = Kills.size(); i != e; ++i)
-      dbgs() << "\n    #" << i << ": " << *Kills[i];
-    dbgs() << "\n";
-  }
-}
-#endif
-
-/// getVarInfo - Get (possibly creating) a VarInfo object for the given vreg.
-LiveVariables::VarInfo &LiveVariables::getVarInfo(unsigned RegIdx) {
-  assert(TargetRegisterInfo::isVirtualRegister(RegIdx) &&
-         "getVarInfo: not a virtual register!");
-  VirtRegInfo.grow(RegIdx);
-  return VirtRegInfo[RegIdx];
-}
-
-void LiveVariables::MarkVirtRegAliveInBlock(VarInfo& VRInfo,
-                                            MachineBasicBlock *DefBlock,
-                                            MachineBasicBlock *MBB,
-                                    std::vector<MachineBasicBlock*> &WorkList) {
-  unsigned BBNum = MBB->getNumber();
-
-  // Check to see if this basic block is one of the killing blocks.  If so,
-  // remove it.
-  for (unsigned i = 0, e = VRInfo.Kills.size(); i != e; ++i)
-    if (VRInfo.Kills[i]->getParent() == MBB) {
-      VRInfo.Kills.erase(VRInfo.Kills.begin()+i);  // Erase entry
-      break;
-    }
-
-  if (MBB == DefBlock) return;  // Terminate recursion
-
-  if (VRInfo.AliveBlocks.test(BBNum))
-    return;  // We already know the block is live
-
-  // Mark the variable known alive in this bb
-  VRInfo.AliveBlocks.set(BBNum);
-
-  assert(MBB != &MF->front() && "Can't find reaching def for virtreg");
-  WorkList.insert(WorkList.end(), MBB->pred_rbegin(), MBB->pred_rend());
-}
-
-void LiveVariables::MarkVirtRegAliveInBlock(VarInfo &VRInfo,
-                                            MachineBasicBlock *DefBlock,
-                                            MachineBasicBlock *MBB) {
-  std::vector<MachineBasicBlock*> WorkList;
-  MarkVirtRegAliveInBlock(VRInfo, DefBlock, MBB, WorkList);
-
-  while (!WorkList.empty()) {
-    MachineBasicBlock *Pred = WorkList.back();
-    WorkList.pop_back();
-    MarkVirtRegAliveInBlock(VRInfo, DefBlock, Pred, WorkList);
-  }
-}
-
-void LiveVariables::HandleVirtRegUse(unsigned reg, MachineBasicBlock *MBB,
-                                     MachineInstr &MI) {
-  assert(MRI->getVRegDef(reg) && "Register use before def!");
-
-  unsigned BBNum = MBB->getNumber();
-
-  VarInfo& VRInfo = getVarInfo(reg);
-
-  // Check to see if this basic block is already a kill block.
-  if (!VRInfo.Kills.empty() && VRInfo.Kills.back()->getParent() == MBB) {
-    // Yes, this register is killed in this basic block already. Increase the
-    // live range by updating the kill instruction.
-    VRInfo.Kills.back() = &MI;
-    return;
-  }
-
-#ifndef NDEBUG
-  for (unsigned i = 0, e = VRInfo.Kills.size(); i != e; ++i)
-    assert(VRInfo.Kills[i]->getParent() != MBB && "entry should be at end!");
-#endif
-
-  // This situation can occur:
-  //
-  //     ,------.
-  //     |      |
-  //     |      v
-  //     |   t2 = phi ... t1 ...
-  //     |      |
-  //     |      v
-  //     |   t1 = ...
-  //     |  ... = ... t1 ...
-  //     |      |
-  //     `------'
-  //
-  // where there is a use in a PHI node that's a predecessor to the defining
-  // block. We don't want to mark all predecessors as having the value "alive"
-  // in this case.
-  if (MBB == MRI->getVRegDef(reg)->getParent()) return;
-
-  // Add a new kill entry for this basic block. If this virtual register is
-  // already marked as alive in this basic block, that means it is alive in at
-  // least one of the successor blocks, it's not a kill.
-  if (!VRInfo.AliveBlocks.test(BBNum))
-    VRInfo.Kills.push_back(&MI);
-
-  // Update all dominating blocks to mark them as "known live".
-  for (MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(),
-         E = MBB->pred_end(); PI != E; ++PI)
-    MarkVirtRegAliveInBlock(VRInfo, MRI->getVRegDef(reg)->getParent(), *PI);
-}
-
-void LiveVariables::HandleVirtRegDef(unsigned Reg, MachineInstr &MI) {
-  VarInfo &VRInfo = getVarInfo(Reg);
-
-  if (VRInfo.AliveBlocks.empty())
-    // If vr is not alive in any block, then defaults to dead.
-    VRInfo.Kills.push_back(&MI);
-}
-
-/// FindLastPartialDef - Return the last partial def of the specified register.
-/// Also returns the sub-registers that're defined by the instruction.
-MachineInstr *LiveVariables::FindLastPartialDef(unsigned Reg,
-                                            SmallSet<unsigned,4> &PartDefRegs) {
-  unsigned LastDefReg = 0;
-  unsigned LastDefDist = 0;
-  MachineInstr *LastDef = nullptr;
-  for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs) {
-    unsigned SubReg = *SubRegs;
-    MachineInstr *Def = PhysRegDef[SubReg];
-    if (!Def)
-      continue;
-    unsigned Dist = DistanceMap[Def];
-    if (Dist > LastDefDist) {
-      LastDefReg  = SubReg;
-      LastDef     = Def;
-      LastDefDist = Dist;
-    }
-  }
-
-  if (!LastDef)
-    return nullptr;
-
-  PartDefRegs.insert(LastDefReg);
-  for (unsigned i = 0, e = LastDef->getNumOperands(); i != e; ++i) {
-    MachineOperand &MO = LastDef->getOperand(i);
-    if (!MO.isReg() || !MO.isDef() || MO.getReg() == 0)
-      continue;
-    unsigned DefReg = MO.getReg();
-    if (TRI->isSubRegister(Reg, DefReg)) {
-      for (MCSubRegIterator SubRegs(DefReg, TRI, /*IncludeSelf=*/true);
-           SubRegs.isValid(); ++SubRegs)
-        PartDefRegs.insert(*SubRegs);
-    }
-  }
-  return LastDef;
-}
-
-/// HandlePhysRegUse - Turn previous partial def's into read/mod/writes. Add
-/// implicit defs to a machine instruction if there was an earlier def of its
-/// super-register.
-void LiveVariables::HandlePhysRegUse(unsigned Reg, MachineInstr &MI) {
-  MachineInstr *LastDef = PhysRegDef[Reg];
-  // If there was a previous use or a "full" def all is well.
-  if (!LastDef && !PhysRegUse[Reg]) {
-    // Otherwise, the last sub-register def implicitly defines this register.
-    // e.g.
-    // AH =
-    // AL = ... implicit-def EAX, implicit killed AH
-    //    = AH
-    // ...
-    //    = EAX
-    // All of the sub-registers must have been defined before the use of Reg!
-    SmallSet<unsigned, 4> PartDefRegs;
-    MachineInstr *LastPartialDef = FindLastPartialDef(Reg, PartDefRegs);
-    // If LastPartialDef is NULL, it must be using a livein register.
-    if (LastPartialDef) {
-      LastPartialDef->addOperand(MachineOperand::CreateReg(Reg, true/*IsDef*/,
-                                                           true/*IsImp*/));
-      PhysRegDef[Reg] = LastPartialDef;
-      SmallSet<unsigned, 8> Processed;
-      for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs) {
-        unsigned SubReg = *SubRegs;
-        if (Processed.count(SubReg))
-          continue;
-        if (PartDefRegs.count(SubReg))
-          continue;
-        // This part of Reg was defined before the last partial def. It's killed
-        // here.
-        LastPartialDef->addOperand(MachineOperand::CreateReg(SubReg,
-                                                             false/*IsDef*/,
-                                                             true/*IsImp*/));
-        PhysRegDef[SubReg] = LastPartialDef;
-        for (MCSubRegIterator SS(SubReg, TRI); SS.isValid(); ++SS)
-          Processed.insert(*SS);
-      }
-    }
-  } else if (LastDef && !PhysRegUse[Reg] &&
-             !LastDef->findRegisterDefOperand(Reg))
-    // Last def defines the super register, add an implicit def of reg.
-    LastDef->addOperand(MachineOperand::CreateReg(Reg, true/*IsDef*/,
-                                                  true/*IsImp*/));
-
-  // Remember this use.
-  for (MCSubRegIterator SubRegs(Reg, TRI, /*IncludeSelf=*/true);
-       SubRegs.isValid(); ++SubRegs)
-    PhysRegUse[*SubRegs] = &MI;
-}
-
-/// FindLastRefOrPartRef - Return the last reference or partial reference of
-/// the specified register.
-MachineInstr *LiveVariables::FindLastRefOrPartRef(unsigned Reg) {
-  MachineInstr *LastDef = PhysRegDef[Reg];
-  MachineInstr *LastUse = PhysRegUse[Reg];
-  if (!LastDef && !LastUse)
-    return nullptr;
-
-  MachineInstr *LastRefOrPartRef = LastUse ? LastUse : LastDef;
-  unsigned LastRefOrPartRefDist = DistanceMap[LastRefOrPartRef];
-  unsigned LastPartDefDist = 0;
-  for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs) {
-    unsigned SubReg = *SubRegs;
-    MachineInstr *Def = PhysRegDef[SubReg];
-    if (Def && Def != LastDef) {
-      // There was a def of this sub-register in between. This is a partial
-      // def, keep track of the last one.
-      unsigned Dist = DistanceMap[Def];
-      if (Dist > LastPartDefDist)
-        LastPartDefDist = Dist;
-    } else if (MachineInstr *Use = PhysRegUse[SubReg]) {
-      unsigned Dist = DistanceMap[Use];
-      if (Dist > LastRefOrPartRefDist) {
-        LastRefOrPartRefDist = Dist;
-        LastRefOrPartRef = Use;
-      }
-    }
-  }
-
-  return LastRefOrPartRef;
-}
-
-bool LiveVariables::HandlePhysRegKill(unsigned Reg, MachineInstr *MI) {
-  MachineInstr *LastDef = PhysRegDef[Reg];
-  MachineInstr *LastUse = PhysRegUse[Reg];
-  if (!LastDef && !LastUse)
-    return false;
-
-  MachineInstr *LastRefOrPartRef = LastUse ? LastUse : LastDef;
-  unsigned LastRefOrPartRefDist = DistanceMap[LastRefOrPartRef];
-  // The whole register is used.
-  // AL =
-  // AH =
-  //
-  //    = AX
-  //    = AL, implicit killed AX
-  // AX =
-  //
-  // Or whole register is defined, but not used at all.
-  // dead AX =
-  // ...
-  // AX =
-  //
-  // Or whole register is defined, but only partly used.
-  // dead AX = implicit-def AL
-  //    = killed AL
-  // AX =
-  MachineInstr *LastPartDef = nullptr;
-  unsigned LastPartDefDist = 0;
-  SmallSet<unsigned, 8> PartUses;
-  for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs) {
-    unsigned SubReg = *SubRegs;
-    MachineInstr *Def = PhysRegDef[SubReg];
-    if (Def && Def != LastDef) {
-      // There was a def of this sub-register in between. This is a partial
-      // def, keep track of the last one.
-      unsigned Dist = DistanceMap[Def];
-      if (Dist > LastPartDefDist) {
-        LastPartDefDist = Dist;
-        LastPartDef = Def;
-      }
-      continue;
-    }
-    if (MachineInstr *Use = PhysRegUse[SubReg]) {
-      for (MCSubRegIterator SS(SubReg, TRI, /*IncludeSelf=*/true); SS.isValid();
-           ++SS)
-        PartUses.insert(*SS);
-      unsigned Dist = DistanceMap[Use];
-      if (Dist > LastRefOrPartRefDist) {
-        LastRefOrPartRefDist = Dist;
-        LastRefOrPartRef = Use;
-      }
-    }
-  }
-
-  if (!PhysRegUse[Reg]) {
-    // Partial uses. Mark register def dead and add implicit def of
-    // sub-registers which are used.
-    // dead EAX  = op  implicit-def AL
-    // That is, EAX def is dead but AL def extends pass it.
-    PhysRegDef[Reg]->addRegisterDead(Reg, TRI, true);
-    for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs) {
-      unsigned SubReg = *SubRegs;
-      if (!PartUses.count(SubReg))
-        continue;
-      bool NeedDef = true;
-      if (PhysRegDef[Reg] == PhysRegDef[SubReg]) {
-        MachineOperand *MO = PhysRegDef[Reg]->findRegisterDefOperand(SubReg);
-        if (MO) {
-          NeedDef = false;
-          assert(!MO->isDead());
-        }
-      }
-      if (NeedDef)
-        PhysRegDef[Reg]->addOperand(MachineOperand::CreateReg(SubReg,
-                                                 true/*IsDef*/, true/*IsImp*/));
-      MachineInstr *LastSubRef = FindLastRefOrPartRef(SubReg);
-      if (LastSubRef)
-        LastSubRef->addRegisterKilled(SubReg, TRI, true);
-      else {
-        LastRefOrPartRef->addRegisterKilled(SubReg, TRI, true);
-        for (MCSubRegIterator SS(SubReg, TRI, /*IncludeSelf=*/true);
-             SS.isValid(); ++SS)
-          PhysRegUse[*SS] = LastRefOrPartRef;
-      }
-      for (MCSubRegIterator SS(SubReg, TRI); SS.isValid(); ++SS)
-        PartUses.erase(*SS);
-    }
-  } else if (LastRefOrPartRef == PhysRegDef[Reg] && LastRefOrPartRef != MI) {
-    if (LastPartDef)
-      // The last partial def kills the register.
-      LastPartDef->addOperand(MachineOperand::CreateReg(Reg, false/*IsDef*/,
-                                                true/*IsImp*/, true/*IsKill*/));
-    else {
-      MachineOperand *MO =
-        LastRefOrPartRef->findRegisterDefOperand(Reg, false, false, TRI);
-      bool NeedEC = MO->isEarlyClobber() && MO->getReg() != Reg;
-      // If the last reference is the last def, then it's not used at all.
-      // That is, unless we are currently processing the last reference itself.
-      LastRefOrPartRef->addRegisterDead(Reg, TRI, true);
-      if (NeedEC) {
-        // If we are adding a subreg def and the superreg def is marked early
-        // clobber, add an early clobber marker to the subreg def.
-        MO = LastRefOrPartRef->findRegisterDefOperand(Reg);
-        if (MO)
-          MO->setIsEarlyClobber();
-      }
-    }
-  } else
-    LastRefOrPartRef->addRegisterKilled(Reg, TRI, true);
-  return true;
-}
-
-void LiveVariables::HandleRegMask(const MachineOperand &MO) {
-  // Call HandlePhysRegKill() for all live registers clobbered by Mask.
-  // Clobbered registers are always dead, sp there is no need to use
-  // HandlePhysRegDef().
-  for (unsigned Reg = 1, NumRegs = TRI->getNumRegs(); Reg != NumRegs; ++Reg) {
-    // Skip dead regs.
-    if (!PhysRegDef[Reg] && !PhysRegUse[Reg])
-      continue;
-    // Skip mask-preserved regs.
-    if (!MO.clobbersPhysReg(Reg))
-      continue;
-    // Kill the largest clobbered super-register.
-    // This avoids needless implicit operands.
-    unsigned Super = Reg;
-    for (MCSuperRegIterator SR(Reg, TRI); SR.isValid(); ++SR)
-      if ((PhysRegDef[*SR] || PhysRegUse[*SR]) && MO.clobbersPhysReg(*SR))
-        Super = *SR;
-    HandlePhysRegKill(Super, nullptr);
-  }
-}
-
-void LiveVariables::HandlePhysRegDef(unsigned Reg, MachineInstr *MI,
-                                     SmallVectorImpl<unsigned> &Defs) {
-  // What parts of the register are previously defined?
-  SmallSet<unsigned, 32> Live;
-  if (PhysRegDef[Reg] || PhysRegUse[Reg]) {
-    for (MCSubRegIterator SubRegs(Reg, TRI, /*IncludeSelf=*/true);
-         SubRegs.isValid(); ++SubRegs)
-      Live.insert(*SubRegs);
-  } else {
-    for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs) {
-      unsigned SubReg = *SubRegs;
-      // If a register isn't itself defined, but all parts that make up of it
-      // are defined, then consider it also defined.
-      // e.g.
-      // AL =
-      // AH =
-      //    = AX
-      if (Live.count(SubReg))
-        continue;
-      if (PhysRegDef[SubReg] || PhysRegUse[SubReg]) {
-        for (MCSubRegIterator SS(SubReg, TRI, /*IncludeSelf=*/true);
-             SS.isValid(); ++SS)
-          Live.insert(*SS);
-      }
-    }
-  }
-
-  // Start from the largest piece, find the last time any part of the register
-  // is referenced.
-  HandlePhysRegKill(Reg, MI);
-  // Only some of the sub-registers are used.
-  for (MCSubRegIterator SubRegs(Reg, TRI); SubRegs.isValid(); ++SubRegs) {
-    unsigned SubReg = *SubRegs;
-    if (!Live.count(SubReg))
-      // Skip if this sub-register isn't defined.
-      continue;
-    HandlePhysRegKill(SubReg, MI);
-  }
-
-  if (MI)
-    Defs.push_back(Reg);  // Remember this def.
-}
-
-void LiveVariables::UpdatePhysRegDefs(MachineInstr &MI,
-                                      SmallVectorImpl<unsigned> &Defs) {
-  while (!Defs.empty()) {
-    unsigned Reg = Defs.back();
-    Defs.pop_back();
-    for (MCSubRegIterator SubRegs(Reg, TRI, /*IncludeSelf=*/true);
-         SubRegs.isValid(); ++SubRegs) {
-      unsigned SubReg = *SubRegs;
-      PhysRegDef[SubReg] = &MI;
-      PhysRegUse[SubReg]  = nullptr;
-    }
-  }
-}
-
-void LiveVariables::runOnInstr(MachineInstr &MI,
-                               SmallVectorImpl<unsigned> &Defs) {
-  assert(!MI.isDebugInstr());
-  // Process all of the operands of the instruction...
-  unsigned NumOperandsToProcess = MI.getNumOperands();
-
-  // Unless it is a PHI node.  In this case, ONLY process the DEF, not any
-  // of the uses.  They will be handled in other basic blocks.
-  if (MI.isPHI())
-    NumOperandsToProcess = 1;
-
-  // Clear kill and dead markers. LV will recompute them.
-  SmallVector<unsigned, 4> UseRegs;
-  SmallVector<unsigned, 4> DefRegs;
-  SmallVector<unsigned, 1> RegMasks;
-  for (unsigned i = 0; i != NumOperandsToProcess; ++i) {
-    MachineOperand &MO = MI.getOperand(i);
-    if (MO.isRegMask()) {
-      RegMasks.push_back(i);
-      continue;
-    }
-    if (!MO.isReg() || MO.getReg() == 0)
-      continue;
-    unsigned MOReg = MO.getReg();
-    if (MO.isUse()) {
-      if (!(TargetRegisterInfo::isPhysicalRegister(MOReg) &&
-            MRI->isReserved(MOReg)))
-        MO.setIsKill(false);
-      if (MO.readsReg())
-        UseRegs.push_back(MOReg);
-    } else {
-      assert(MO.isDef());
-      // FIXME: We should not remove any dead flags. However the MIPS RDDSP
-      // instruction needs it at the moment: http://llvm.org/PR27116.
-      if (TargetRegisterInfo::isPhysicalRegister(MOReg) &&
-          !MRI->isReserved(MOReg))
-        MO.setIsDead(false);
-      DefRegs.push_back(MOReg);
-    }
-  }
-
-  MachineBasicBlock *MBB = MI.getParent();
-  // Process all uses.
-  for (unsigned i = 0, e = UseRegs.size(); i != e; ++i) {
-    unsigned MOReg = UseRegs[i];
-    if (TargetRegisterInfo::isVirtualRegister(MOReg))
-      HandleVirtRegUse(MOReg, MBB, MI);
-    else if (!MRI->isReserved(MOReg))
-      HandlePhysRegUse(MOReg, MI);
-  }
-
-  // Process all masked registers. (Call clobbers).
-  for (unsigned i = 0, e = RegMasks.size(); i != e; ++i)
-    HandleRegMask(MI.getOperand(RegMasks[i]));
-
-  // Process all defs.
-  for (unsigned i = 0, e = DefRegs.size(); i != e; ++i) {
-    unsigned MOReg = DefRegs[i];
-    if (TargetRegisterInfo::isVirtualRegister(MOReg))
-      HandleVirtRegDef(MOReg, MI);
-    else if (!MRI->isReserved(MOReg))
-      HandlePhysRegDef(MOReg, &MI, Defs);
-  }
-  UpdatePhysRegDefs(MI, Defs);
-}
-
-void LiveVariables::runOnBlock(MachineBasicBlock *MBB, const unsigned NumRegs) {
-  // Mark live-in registers as live-in.
-  SmallVector<unsigned, 4> Defs;
-  for (const auto &LI : MBB->liveins()) {
-    assert(TargetRegisterInfo::isPhysicalRegister(LI.PhysReg) &&
-           "Cannot have a live-in virtual register!");
-    HandlePhysRegDef(LI.PhysReg, nullptr, Defs);
-  }
-
-  // Loop over all of the instructions, processing them.
-  DistanceMap.clear();
-  unsigned Dist = 0;
-  for (MachineInstr &MI : *MBB) {
-    if (MI.isDebugInstr())
-      continue;
-    DistanceMap.insert(std::make_pair(&MI, Dist++));
-
-    runOnInstr(MI, Defs);
-  }
-
-  // Handle any virtual assignments from PHI nodes which might be at the
-  // bottom of this basic block.  We check all of our successor blocks to see
-  // if they have PHI nodes, and if so, we simulate an assignment at the end
-  // of the current block.
-  if (!PHIVarInfo[MBB->getNumber()].empty()) {
-    SmallVectorImpl<unsigned> &VarInfoVec = PHIVarInfo[MBB->getNumber()];
-
-    for (SmallVectorImpl<unsigned>::iterator I = VarInfoVec.begin(),
-           E = VarInfoVec.end(); I != E; ++I)
-      // Mark it alive only in the block we are representing.
-      MarkVirtRegAliveInBlock(getVarInfo(*I),MRI->getVRegDef(*I)->getParent(),
-                              MBB);
-  }
-
-  // MachineCSE may CSE instructions which write to non-allocatable physical
-  // registers across MBBs. Remember if any reserved register is liveout.
-  SmallSet<unsigned, 4> LiveOuts;
-  for (MachineBasicBlock::const_succ_iterator SI = MBB->succ_begin(),
-         SE = MBB->succ_end(); SI != SE; ++SI) {
-    MachineBasicBlock *SuccMBB = *SI;
-    if (SuccMBB->isEHPad())
-      continue;
-    for (const auto &LI : SuccMBB->liveins()) {
-      if (!TRI->isInAllocatableClass(LI.PhysReg))
-        // Ignore other live-ins, e.g. those that are live into landing pads.
-        LiveOuts.insert(LI.PhysReg);
-    }
-  }
-
-  // Loop over PhysRegDef / PhysRegUse, killing any registers that are
-  // available at the end of the basic block.
-  for (unsigned i = 0; i != NumRegs; ++i)
-    if ((PhysRegDef[i] || PhysRegUse[i]) && !LiveOuts.count(i))
-      HandlePhysRegDef(i, nullptr, Defs);
-}
-
-bool LiveVariables::runOnMachineFunction(MachineFunction &mf) {
-  MF = &mf;
-  MRI = &mf.getRegInfo();
-  TRI = MF->getSubtarget().getRegisterInfo();
-
-  const unsigned NumRegs = TRI->getNumRegs();
-  PhysRegDef.assign(NumRegs, nullptr);
-  PhysRegUse.assign(NumRegs, nullptr);
-  PHIVarInfo.resize(MF->getNumBlockIDs());
-  PHIJoins.clear();
-
-  // FIXME: LiveIntervals will be updated to remove its dependence on
-  // LiveVariables to improve compilation time and eliminate bizarre pass
-  // dependencies. Until then, we can't change much in -O0.
-  if (!MRI->isSSA())
-    report_fatal_error("regalloc=... not currently supported with -O0");
-
-  analyzePHINodes(mf);
-
-  // Calculate live variable information in depth first order on the CFG of the
-  // function.  This guarantees that we will see the definition of a virtual
-  // register before its uses due to dominance properties of SSA (except for PHI
-  // nodes, which are treated as a special case).
-  MachineBasicBlock *Entry = &MF->front();
-  df_iterator_default_set<MachineBasicBlock*,16> Visited;
-
-  for (MachineBasicBlock *MBB : depth_first_ext(Entry, Visited)) {
-    runOnBlock(MBB, NumRegs);
-
-    PhysRegDef.assign(NumRegs, nullptr);
-    PhysRegUse.assign(NumRegs, nullptr);
-  }
-
-  // Convert and transfer the dead / killed information we have gathered into
-  // VirtRegInfo onto MI's.
-  for (unsigned i = 0, e1 = VirtRegInfo.size(); i != e1; ++i) {
-    const unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
-    for (unsigned j = 0, e2 = VirtRegInfo[Reg].Kills.size(); j != e2; ++j)
-      if (VirtRegInfo[Reg].Kills[j] == MRI->getVRegDef(Reg))
-        VirtRegInfo[Reg].Kills[j]->addRegisterDead(Reg, TRI);
-      else
-        VirtRegInfo[Reg].Kills[j]->addRegisterKilled(Reg, TRI);
-  }
-
-  // Check to make sure there are no unreachable blocks in the MC CFG for the
-  // function.  If so, it is due to a bug in the instruction selector or some
-  // other part of the code generator if this happens.
-#ifndef NDEBUG
-  for(MachineFunction::iterator i = MF->begin(), e = MF->end(); i != e; ++i)
-    assert(Visited.count(&*i) != 0 && "unreachable basic block found");
-#endif
-
-  PhysRegDef.clear();
-  PhysRegUse.clear();
-  PHIVarInfo.clear();
-
-  return false;
-}
-
-/// replaceKillInstruction - Update register kill info by replacing a kill
-/// instruction with a new one.
-void LiveVariables::replaceKillInstruction(unsigned Reg, MachineInstr &OldMI,
-                                           MachineInstr &NewMI) {
-  VarInfo &VI = getVarInfo(Reg);
-  std::replace(VI.Kills.begin(), VI.Kills.end(), &OldMI, &NewMI);
-}
-
-/// removeVirtualRegistersKilled - Remove all killed info for the specified
-/// instruction.
-void LiveVariables::removeVirtualRegistersKilled(MachineInstr &MI) {
-  for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
-    MachineOperand &MO = MI.getOperand(i);
-    if (MO.isReg() && MO.isKill()) {
-      MO.setIsKill(false);
-      unsigned Reg = MO.getReg();
-      if (TargetRegisterInfo::isVirtualRegister(Reg)) {
-        bool removed = getVarInfo(Reg).removeKill(MI);
-        assert(removed && "kill not in register's VarInfo?");
-        (void)removed;
-      }
-    }
-  }
-}
-
-/// analyzePHINodes - Gather information about the PHI nodes in here. In
-/// particular, we want to map the variable information of a virtual register
-/// which is used in a PHI node. We map that to the BB the vreg is coming from.
-///
-void LiveVariables::analyzePHINodes(const MachineFunction& Fn) {
-  for (const auto &MBB : Fn)
-    for (const auto &BBI : MBB) {
-      if (!BBI.isPHI())
-        break;
-      for (unsigned i = 1, e = BBI.getNumOperands(); i != e; i += 2)
-        if (BBI.getOperand(i).readsReg())
-          PHIVarInfo[BBI.getOperand(i + 1).getMBB()->getNumber()]
-            .push_back(BBI.getOperand(i).getReg());
-    }
-}
-
-bool LiveVariables::VarInfo::isLiveIn(const MachineBasicBlock &MBB,
-                                      unsigned Reg,
-                                      MachineRegisterInfo &MRI) {
-  unsigned Num = MBB.getNumber();
-
-  // Reg is live-through.
-  if (AliveBlocks.test(Num))
-    return true;
-
-  // Registers defined in MBB cannot be live in.
-  const MachineInstr *Def = MRI.getVRegDef(Reg);
-  if (Def && Def->getParent() == &MBB)
-    return false;
-
- // Reg was not defined in MBB, was it killed here?
-  return findKill(&MBB);
-}
-
-bool LiveVariables::isLiveOut(unsigned Reg, const MachineBasicBlock &MBB) {
-  LiveVariables::VarInfo &VI = getVarInfo(Reg);
-
-  SmallPtrSet<const MachineBasicBlock *, 8> Kills;
-  for (unsigned i = 0, e = VI.Kills.size(); i != e; ++i)
-    Kills.insert(VI.Kills[i]->getParent());
-
-  // Loop over all of the successors of the basic block, checking to see if
-  // the value is either live in the block, or if it is killed in the block.
-  for (const MachineBasicBlock *SuccMBB : MBB.successors()) {
-    // Is it alive in this successor?
-    unsigned SuccIdx = SuccMBB->getNumber();
-    if (VI.AliveBlocks.test(SuccIdx))
-      return true;
-    // Or is it live because there is a use in a successor that kills it?
-    if (Kills.count(SuccMBB))
-      return true;
-  }
-
-  return false;
-}
-
-/// addNewBlock - Add a new basic block BB as an empty succcessor to DomBB. All
-/// variables that are live out of DomBB will be marked as passing live through
-/// BB.
-void LiveVariables::addNewBlock(MachineBasicBlock *BB,
-                                MachineBasicBlock *DomBB,
-                                MachineBasicBlock *SuccBB) {
-  const unsigned NumNew = BB->getNumber();
-
-  DenseSet<unsigned> Defs, Kills;
-
-  MachineBasicBlock::iterator BBI = SuccBB->begin(), BBE = SuccBB->end();
-  for (; BBI != BBE && BBI->isPHI(); ++BBI) {
-    // Record the def of the PHI node.
-    Defs.insert(BBI->getOperand(0).getReg());
-
-    // All registers used by PHI nodes in SuccBB must be live through BB.
-    for (unsigned i = 1, e = BBI->getNumOperands(); i != e; i += 2)
-      if (BBI->getOperand(i+1).getMBB() == BB)
-        getVarInfo(BBI->getOperand(i).getReg()).AliveBlocks.set(NumNew);
-  }
-
-  // Record all vreg defs and kills of all instructions in SuccBB.
-  for (; BBI != BBE; ++BBI) {
-    for (MachineInstr::mop_iterator I = BBI->operands_begin(),
-         E = BBI->operands_end(); I != E; ++I) {
-      if (I->isReg() && TargetRegisterInfo::isVirtualRegister(I->getReg())) {
-        if (I->isDef())
-          Defs.insert(I->getReg());
-        else if (I->isKill())
-          Kills.insert(I->getReg());
-      }
-    }
-  }
-
-  // Update info for all live variables
-  for (unsigned i = 0, e = MRI->getNumVirtRegs(); i != e; ++i) {
-    unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
-
-    // If the Defs is defined in the successor it can't be live in BB.
-    if (Defs.count(Reg))
-      continue;
-
-    // If the register is either killed in or live through SuccBB it's also live
-    // through BB.
-    VarInfo &VI = getVarInfo(Reg);
-    if (Kills.count(Reg) || VI.AliveBlocks.test(SuccBB->getNumber()))
-      VI.AliveBlocks.set(NumNew);
-  }
-}