1 files changed, 0 insertions, 476 deletions

diff --git a/contrib/llvm/lib/CodeGen/LiveRangeEdit.cpp b/contrib/llvm/lib/CodeGen/LiveRangeEdit.cpp
deleted file mode 100644
index 882e562ba95c..000000000000
--- a/contrib/llvm/lib/CodeGen/LiveRangeEdit.cpp
+++ /dev/null
@@ -1,476 +0,0 @@
-//===-- LiveRangeEdit.cpp - Basic tools for editing a register live range -===//
-//
-// 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
-//
-//===----------------------------------------------------------------------===//
-//
-// The LiveRangeEdit class represents changes done to a virtual register when it
-// is spilled or split.
-//===----------------------------------------------------------------------===//
-
-#include "llvm/CodeGen/LiveRangeEdit.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/CodeGen/CalcSpillWeights.h"
-#include "llvm/CodeGen/LiveIntervals.h"
-#include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/CodeGen/TargetInstrInfo.h"
-#include "llvm/CodeGen/VirtRegMap.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/raw_ostream.h"
-
-using namespace llvm;
-
-#define DEBUG_TYPE "regalloc"
-
-STATISTIC(NumDCEDeleted,     "Number of instructions deleted by DCE");
-STATISTIC(NumDCEFoldedLoads, "Number of single use loads folded after DCE");
-STATISTIC(NumFracRanges,     "Number of live ranges fractured by DCE");
-
-void LiveRangeEdit::Delegate::anchor() { }
-
-LiveInterval &LiveRangeEdit::createEmptyIntervalFrom(unsigned OldReg,
-                                                     bool createSubRanges) {
-  unsigned VReg = MRI.createVirtualRegister(MRI.getRegClass(OldReg));
-  if (VRM)
-    VRM->setIsSplitFromReg(VReg, VRM->getOriginal(OldReg));
-
-  LiveInterval &LI = LIS.createEmptyInterval(VReg);
-  if (Parent && !Parent->isSpillable())
-    LI.markNotSpillable();
-  if (createSubRanges) {
-    // Create empty subranges if the OldReg's interval has them. Do not create
-    // the main range here---it will be constructed later after the subranges
-    // have been finalized.
-    LiveInterval &OldLI = LIS.getInterval(OldReg);
-    VNInfo::Allocator &Alloc = LIS.getVNInfoAllocator();
-    for (LiveInterval::SubRange &S : OldLI.subranges())
-      LI.createSubRange(Alloc, S.LaneMask);
-  }
-  return LI;
-}
-
-unsigned LiveRangeEdit::createFrom(unsigned OldReg) {
-  unsigned VReg = MRI.createVirtualRegister(MRI.getRegClass(OldReg));
-  if (VRM) {
-    VRM->setIsSplitFromReg(VReg, VRM->getOriginal(OldReg));
-  }
-  // FIXME: Getting the interval here actually computes it.
-  // In theory, this may not be what we want, but in practice
-  // the createEmptyIntervalFrom API is used when this is not
-  // the case. Generally speaking we just want to annotate the
-  // LiveInterval when it gets created but we cannot do that at
-  // the moment.
-  if (Parent && !Parent->isSpillable())
-    LIS.getInterval(VReg).markNotSpillable();
-  return VReg;
-}
-
-bool LiveRangeEdit::checkRematerializable(VNInfo *VNI,
-                                          const MachineInstr *DefMI,
-                                          AliasAnalysis *aa) {
-  assert(DefMI && "Missing instruction");
-  ScannedRemattable = true;
-  if (!TII.isTriviallyReMaterializable(*DefMI, aa))
-    return false;
-  Remattable.insert(VNI);
-  return true;
-}
-
-void LiveRangeEdit::scanRemattable(AliasAnalysis *aa) {
-  for (VNInfo *VNI : getParent().valnos) {
-    if (VNI->isUnused())
-      continue;
-    unsigned Original = VRM->getOriginal(getReg());
-    LiveInterval &OrigLI = LIS.getInterval(Original);
-    VNInfo *OrigVNI = OrigLI.getVNInfoAt(VNI->def);
-    if (!OrigVNI)
-      continue;
-    MachineInstr *DefMI = LIS.getInstructionFromIndex(OrigVNI->def);
-    if (!DefMI)
-      continue;
-    checkRematerializable(OrigVNI, DefMI, aa);
-  }
-  ScannedRemattable = true;
-}
-
-bool LiveRangeEdit::anyRematerializable(AliasAnalysis *aa) {
-  if (!ScannedRemattable)
-    scanRemattable(aa);
-  return !Remattable.empty();
-}
-
-/// allUsesAvailableAt - Return true if all registers used by OrigMI at
-/// OrigIdx are also available with the same value at UseIdx.
-bool LiveRangeEdit::allUsesAvailableAt(const MachineInstr *OrigMI,
-                                       SlotIndex OrigIdx,
-                                       SlotIndex UseIdx) const {
-  OrigIdx = OrigIdx.getRegSlot(true);
-  UseIdx = UseIdx.getRegSlot(true);
-  for (unsigned i = 0, e = OrigMI->getNumOperands(); i != e; ++i) {
-    const MachineOperand &MO = OrigMI->getOperand(i);
-    if (!MO.isReg() || !MO.getReg() || !MO.readsReg())
-      continue;
-
-    // We can't remat physreg uses, unless it is a constant.
-    if (TargetRegisterInfo::isPhysicalRegister(MO.getReg())) {
-      if (MRI.isConstantPhysReg(MO.getReg()))
-        continue;
-      return false;
-    }
-
-    LiveInterval &li = LIS.getInterval(MO.getReg());
-    const VNInfo *OVNI = li.getVNInfoAt(OrigIdx);
-    if (!OVNI)
-      continue;
-
-    // Don't allow rematerialization immediately after the original def.
-    // It would be incorrect if OrigMI redefines the register.
-    // See PR14098.
-    if (SlotIndex::isSameInstr(OrigIdx, UseIdx))
-      return false;
-
-    if (OVNI != li.getVNInfoAt(UseIdx))
-      return false;
-  }
-  return true;
-}
-
-bool LiveRangeEdit::canRematerializeAt(Remat &RM, VNInfo *OrigVNI,
-                                       SlotIndex UseIdx, bool cheapAsAMove) {
-  assert(ScannedRemattable && "Call anyRematerializable first");
-
-  // Use scanRemattable info.
-  if (!Remattable.count(OrigVNI))
-    return false;
-
-  // No defining instruction provided.
-  SlotIndex DefIdx;
-  assert(RM.OrigMI && "No defining instruction for remattable value");
-  DefIdx = LIS.getInstructionIndex(*RM.OrigMI);
-
-  // If only cheap remats were requested, bail out early.
-  if (cheapAsAMove && !TII.isAsCheapAsAMove(*RM.OrigMI))
-    return false;
-
-  // Verify that all used registers are available with the same values.
-  if (!allUsesAvailableAt(RM.OrigMI, DefIdx, UseIdx))
-    return false;
-
-  return true;
-}
-
-SlotIndex LiveRangeEdit::rematerializeAt(MachineBasicBlock &MBB,
-                                         MachineBasicBlock::iterator MI,
-                                         unsigned DestReg,
-                                         const Remat &RM,
-                                         const TargetRegisterInfo &tri,
-                                         bool Late) {
-  assert(RM.OrigMI && "Invalid remat");
-  TII.reMaterialize(MBB, MI, DestReg, 0, *RM.OrigMI, tri);
-  // DestReg of the cloned instruction cannot be Dead. Set isDead of DestReg
-  // to false anyway in case the isDead flag of RM.OrigMI's dest register
-  // is true.
-  (*--MI).getOperand(0).setIsDead(false);
-  Rematted.insert(RM.ParentVNI);
-  return LIS.getSlotIndexes()->insertMachineInstrInMaps(*MI, Late).getRegSlot();
-}
-
-void LiveRangeEdit::eraseVirtReg(unsigned Reg) {
-  if (TheDelegate && TheDelegate->LRE_CanEraseVirtReg(Reg))
-    LIS.removeInterval(Reg);
-}
-
-bool LiveRangeEdit::foldAsLoad(LiveInterval *LI,
-                               SmallVectorImpl<MachineInstr*> &Dead) {
-  MachineInstr *DefMI = nullptr, *UseMI = nullptr;
-
-  // Check that there is a single def and a single use.
-  for (MachineOperand &MO : MRI.reg_nodbg_operands(LI->reg)) {
-    MachineInstr *MI = MO.getParent();
-    if (MO.isDef()) {
-      if (DefMI && DefMI != MI)
-        return false;
-      if (!MI->canFoldAsLoad())
-        return false;
-      DefMI = MI;
-    } else if (!MO.isUndef()) {
-      if (UseMI && UseMI != MI)
-        return false;
-      // FIXME: Targets don't know how to fold subreg uses.
-      if (MO.getSubReg())
-        return false;
-      UseMI = MI;
-    }
-  }
-  if (!DefMI || !UseMI)
-    return false;
-
-  // Since we're moving the DefMI load, make sure we're not extending any live
-  // ranges.
-  if (!allUsesAvailableAt(DefMI, LIS.getInstructionIndex(*DefMI),
-                          LIS.getInstructionIndex(*UseMI)))
-    return false;
-
-  // We also need to make sure it is safe to move the load.
-  // Assume there are stores between DefMI and UseMI.
-  bool SawStore = true;
-  if (!DefMI->isSafeToMove(nullptr, SawStore))
-    return false;
-
-  LLVM_DEBUG(dbgs() << "Try to fold single def: " << *DefMI
-                    << "       into single use: " << *UseMI);
-
-  SmallVector<unsigned, 8> Ops;
-  if (UseMI->readsWritesVirtualRegister(LI->reg, &Ops).second)
-    return false;
-
-  MachineInstr *FoldMI = TII.foldMemoryOperand(*UseMI, Ops, *DefMI, &LIS);
-  if (!FoldMI)
-    return false;
-  LLVM_DEBUG(dbgs() << "                folded: " << *FoldMI);
-  LIS.ReplaceMachineInstrInMaps(*UseMI, *FoldMI);
-  if (UseMI->isCall())
-    UseMI->getMF()->updateCallSiteInfo(UseMI, FoldMI);
-  UseMI->eraseFromParent();
-  DefMI->addRegisterDead(LI->reg, nullptr);
-  Dead.push_back(DefMI);
-  ++NumDCEFoldedLoads;
-  return true;
-}
-
-bool LiveRangeEdit::useIsKill(const LiveInterval &LI,
-                              const MachineOperand &MO) const {
-  const MachineInstr &MI = *MO.getParent();
-  SlotIndex Idx = LIS.getInstructionIndex(MI).getRegSlot();
-  if (LI.Query(Idx).isKill())
-    return true;
-  const TargetRegisterInfo &TRI = *MRI.getTargetRegisterInfo();
-  unsigned SubReg = MO.getSubReg();
-  LaneBitmask LaneMask = TRI.getSubRegIndexLaneMask(SubReg);
-  for (const LiveInterval::SubRange &S : LI.subranges()) {
-    if ((S.LaneMask & LaneMask).any() && S.Query(Idx).isKill())
-      return true;
-  }
-  return false;
-}
-
-/// Find all live intervals that need to shrink, then remove the instruction.
-void LiveRangeEdit::eliminateDeadDef(MachineInstr *MI, ToShrinkSet &ToShrink,
-                                     AliasAnalysis *AA) {
-  assert(MI->allDefsAreDead() && "Def isn't really dead");
-  SlotIndex Idx = LIS.getInstructionIndex(*MI).getRegSlot();
-
-  // Never delete a bundled instruction.
-  if (MI->isBundled()) {
-    return;
-  }
-  // Never delete inline asm.
-  if (MI->isInlineAsm()) {
-    LLVM_DEBUG(dbgs() << "Won't delete: " << Idx << '\t' << *MI);
-    return;
-  }
-
-  // Use the same criteria as DeadMachineInstructionElim.
-  bool SawStore = false;
-  if (!MI->isSafeToMove(nullptr, SawStore)) {
-    LLVM_DEBUG(dbgs() << "Can't delete: " << Idx << '\t' << *MI);
-    return;
-  }
-
-  LLVM_DEBUG(dbgs() << "Deleting dead def " << Idx << '\t' << *MI);
-
-  // Collect virtual registers to be erased after MI is gone.
-  SmallVector<unsigned, 8> RegsToErase;
-  bool ReadsPhysRegs = false;
-  bool isOrigDef = false;
-  unsigned Dest;
-  // Only optimize rematerialize case when the instruction has one def, since
-  // otherwise we could leave some dead defs in the code.  This case is
-  // extremely rare.
-  if (VRM && MI->getOperand(0).isReg() && MI->getOperand(0).isDef() &&
-      MI->getDesc().getNumDefs() == 1) {
-    Dest = MI->getOperand(0).getReg();
-    unsigned Original = VRM->getOriginal(Dest);
-    LiveInterval &OrigLI = LIS.getInterval(Original);
-    VNInfo *OrigVNI = OrigLI.getVNInfoAt(Idx);
-    // The original live-range may have been shrunk to
-    // an empty live-range. It happens when it is dead, but
-    // we still keep it around to be able to rematerialize
-    // other values that depend on it.
-    if (OrigVNI)
-      isOrigDef = SlotIndex::isSameInstr(OrigVNI->def, Idx);
-  }
-
-  // Check for live intervals that may shrink
-  for (MachineInstr::mop_iterator MOI = MI->operands_begin(),
-         MOE = MI->operands_end(); MOI != MOE; ++MOI) {
-    if (!MOI->isReg())
-      continue;
-    unsigned Reg = MOI->getReg();
-    if (!TargetRegisterInfo::isVirtualRegister(Reg)) {
-      // Check if MI reads any unreserved physregs.
-      if (Reg && MOI->readsReg() && !MRI.isReserved(Reg))
-        ReadsPhysRegs = true;
-      else if (MOI->isDef())
-        LIS.removePhysRegDefAt(Reg, Idx);
-      continue;
-    }
-    LiveInterval &LI = LIS.getInterval(Reg);
-
-    // Shrink read registers, unless it is likely to be expensive and
-    // unlikely to change anything. We typically don't want to shrink the
-    // PIC base register that has lots of uses everywhere.
-    // Always shrink COPY uses that probably come from live range splitting.
-    if ((MI->readsVirtualRegister(Reg) && (MI->isCopy() || MOI->isDef())) ||
-        (MOI->readsReg() && (MRI.hasOneNonDBGUse(Reg) || useIsKill(LI, *MOI))))
-      ToShrink.insert(&LI);
-
-    // Remove defined value.
-    if (MOI->isDef()) {
-      if (TheDelegate && LI.getVNInfoAt(Idx) != nullptr)
-        TheDelegate->LRE_WillShrinkVirtReg(LI.reg);
-      LIS.removeVRegDefAt(LI, Idx);
-      if (LI.empty())
-        RegsToErase.push_back(Reg);
-    }
-  }
-
-  // Currently, we don't support DCE of physreg live ranges. If MI reads
-  // any unreserved physregs, don't erase the instruction, but turn it into
-  // a KILL instead. This way, the physreg live ranges don't end up
-  // dangling.
-  // FIXME: It would be better to have something like shrinkToUses() for
-  // physregs. That could potentially enable more DCE and it would free up
-  // the physreg. It would not happen often, though.
-  if (ReadsPhysRegs) {
-    MI->setDesc(TII.get(TargetOpcode::KILL));
-    // Remove all operands that aren't physregs.
-    for (unsigned i = MI->getNumOperands(); i; --i) {
-      const MachineOperand &MO = MI->getOperand(i-1);
-      if (MO.isReg() && TargetRegisterInfo::isPhysicalRegister(MO.getReg()))
-        continue;
-      MI->RemoveOperand(i-1);
-    }
-    LLVM_DEBUG(dbgs() << "Converted physregs to:\t" << *MI);
-  } else {
-    // If the dest of MI is an original reg and MI is reMaterializable,
-    // don't delete the inst. Replace the dest with a new reg, and keep
-    // the inst for remat of other siblings. The inst is saved in
-    // LiveRangeEdit::DeadRemats and will be deleted after all the
-    // allocations of the func are done.
-    if (isOrigDef && DeadRemats && TII.isTriviallyReMaterializable(*MI, AA)) {
-      LiveInterval &NewLI = createEmptyIntervalFrom(Dest, false);
-      VNInfo *VNI = NewLI.getNextValue(Idx, LIS.getVNInfoAllocator());
-      NewLI.addSegment(LiveInterval::Segment(Idx, Idx.getDeadSlot(), VNI));
-      pop_back();
-      DeadRemats->insert(MI);
-      const TargetRegisterInfo &TRI = *MRI.getTargetRegisterInfo();
-      MI->substituteRegister(Dest, NewLI.reg, 0, TRI);
-      MI->getOperand(0).setIsDead(true);
-    } else {
-      if (TheDelegate)
-        TheDelegate->LRE_WillEraseInstruction(MI);
-      LIS.RemoveMachineInstrFromMaps(*MI);
-      MI->eraseFromParent();
-      ++NumDCEDeleted;
-    }
-  }
-
-  // Erase any virtregs that are now empty and unused. There may be <undef>
-  // uses around. Keep the empty live range in that case.
-  for (unsigned i = 0, e = RegsToErase.size(); i != e; ++i) {
-    unsigned Reg = RegsToErase[i];
-    if (LIS.hasInterval(Reg) && MRI.reg_nodbg_empty(Reg)) {
-      ToShrink.remove(&LIS.getInterval(Reg));
-      eraseVirtReg(Reg);
-    }
-  }
-}
-
-void LiveRangeEdit::eliminateDeadDefs(SmallVectorImpl<MachineInstr *> &Dead,
-                                      ArrayRef<unsigned> RegsBeingSpilled,
-                                      AliasAnalysis *AA) {
-  ToShrinkSet ToShrink;
-
-  for (;;) {
-    // Erase all dead defs.
-    while (!Dead.empty())
-      eliminateDeadDef(Dead.pop_back_val(), ToShrink, AA);
-
-    if (ToShrink.empty())
-      break;
-
-    // Shrink just one live interval. Then delete new dead defs.
-    LiveInterval *LI = ToShrink.back();
-    ToShrink.pop_back();
-    if (foldAsLoad(LI, Dead))
-      continue;
-    unsigned VReg = LI->reg;
-    if (TheDelegate)
-      TheDelegate->LRE_WillShrinkVirtReg(VReg);
-    if (!LIS.shrinkToUses(LI, &Dead))
-      continue;
-
-    // Don't create new intervals for a register being spilled.
-    // The new intervals would have to be spilled anyway so its not worth it.
-    // Also they currently aren't spilled so creating them and not spilling
-    // them results in incorrect code.
-    bool BeingSpilled = false;
-    for (unsigned i = 0, e = RegsBeingSpilled.size(); i != e; ++i) {
-      if (VReg == RegsBeingSpilled[i]) {
-        BeingSpilled = true;
-        break;
-      }
-    }
-
-    if (BeingSpilled) continue;
-
-    // LI may have been separated, create new intervals.
-    LI->RenumberValues();
-    SmallVector<LiveInterval*, 8> SplitLIs;
-    LIS.splitSeparateComponents(*LI, SplitLIs);
-    if (!SplitLIs.empty())
-      ++NumFracRanges;
-
-    unsigned Original = VRM ? VRM->getOriginal(VReg) : 0;
-    for (const LiveInterval *SplitLI : SplitLIs) {
-      // If LI is an original interval that hasn't been split yet, make the new
-      // intervals their own originals instead of referring to LI. The original
-      // interval must contain all the split products, and LI doesn't.
-      if (Original != VReg && Original != 0)
-        VRM->setIsSplitFromReg(SplitLI->reg, Original);
-      if (TheDelegate)
-        TheDelegate->LRE_DidCloneVirtReg(SplitLI->reg, VReg);
-    }
-  }
-}
-
-// Keep track of new virtual registers created via
-// MachineRegisterInfo::createVirtualRegister.
-void
-LiveRangeEdit::MRI_NoteNewVirtualRegister(unsigned VReg)
-{
-  if (VRM)
-    VRM->grow();
-
-  NewRegs.push_back(VReg);
-}
-
-void
-LiveRangeEdit::calculateRegClassAndHint(MachineFunction &MF,
-                                        const MachineLoopInfo &Loops,
-                                        const MachineBlockFrequencyInfo &MBFI) {
-  VirtRegAuxInfo VRAI(MF, LIS, VRM, Loops, MBFI);
-  for (unsigned I = 0, Size = size(); I < Size; ++I) {
-    LiveInterval &LI = LIS.getInterval(get(I));
-    if (MRI.recomputeRegClass(LI.reg))
-      LLVM_DEBUG({
-        const TargetRegisterInfo *TRI = MF.getSubtarget().getRegisterInfo();
-        dbgs() << "Inflated " << printReg(LI.reg) << " to "
-               << TRI->getRegClassName(MRI.getRegClass(LI.reg)) << '\n';
-      });
-    VRAI.calculateSpillWeightAndHint(LI);
-  }
-}