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diff --git a/gnu/llvm/lib/CodeGen/StackSlotColoring.cpp b/gnu/llvm/lib/CodeGen/StackSlotColoring.cpp
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+++ b/gnu/llvm/lib/CodeGen/StackSlotColoring.cpp
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+//===-- StackSlotColoring.cpp - Stack slot coloring pass. -----------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the stack slot coloring pass.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/ADT/BitVector.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/CodeGen/LiveIntervalAnalysis.h"
+#include "llvm/CodeGen/LiveStackAnalysis.h"
+#include "llvm/CodeGen/MachineBlockFrequencyInfo.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineMemOperand.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/PseudoSourceValue.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Target/TargetSubtargetInfo.h"
+#include <vector>
+using namespace llvm;
+
+#define DEBUG_TYPE "stackslotcoloring"
+
+static cl::opt<bool>
+DisableSharing("no-stack-slot-sharing",
+             cl::init(false), cl::Hidden,
+             cl::desc("Suppress slot sharing during stack coloring"));
+
+static cl::opt<int> DCELimit("ssc-dce-limit", cl::init(-1), cl::Hidden);
+
+STATISTIC(NumEliminated, "Number of stack slots eliminated due to coloring");
+STATISTIC(NumDead,       "Number of trivially dead stack accesses eliminated");
+
+namespace {
+  class StackSlotColoring : public MachineFunctionPass {
+    LiveStacks* LS;
+    MachineFrameInfo *MFI;
+    const TargetInstrInfo  *TII;
+    const MachineBlockFrequencyInfo *MBFI;
+
+    // SSIntervals - Spill slot intervals.
+    std::vector<LiveInterval*> SSIntervals;
+
+    // SSRefs - Keep a list of MachineMemOperands for each spill slot.
+    // MachineMemOperands can be shared between instructions, so we need
+    // to be careful that renames like [FI0, FI1] -> [FI1, FI2] do not
+    // become FI0 -> FI1 -> FI2.
+    SmallVector<SmallVector<MachineMemOperand *, 8>, 16> SSRefs;
+
+    // OrigAlignments - Alignments of stack objects before coloring.
+    SmallVector<unsigned, 16> OrigAlignments;
+
+    // OrigSizes - Sizess of stack objects before coloring.
+    SmallVector<unsigned, 16> OrigSizes;
+
+    // AllColors - If index is set, it's a spill slot, i.e. color.
+    // FIXME: This assumes PEI locate spill slot with smaller indices
+    // closest to stack pointer / frame pointer. Therefore, smaller
+    // index == better color.
+    BitVector AllColors;
+
+    // NextColor - Next "color" that's not yet used.
+    int NextColor;
+
+    // UsedColors - "Colors" that have been assigned.
+    BitVector UsedColors;
+
+    // Assignments - Color to intervals mapping.
+    SmallVector<SmallVector<LiveInterval*,4>, 16> Assignments;
+
+  public:
+    static char ID; // Pass identification
+    StackSlotColoring() :
+      MachineFunctionPass(ID), NextColor(-1) {
+        initializeStackSlotColoringPass(*PassRegistry::getPassRegistry());
+      }
+
+    void getAnalysisUsage(AnalysisUsage &AU) const override {
+      AU.setPreservesCFG();
+      AU.addRequired<SlotIndexes>();
+      AU.addPreserved<SlotIndexes>();
+      AU.addRequired<LiveStacks>();
+      AU.addRequired<MachineBlockFrequencyInfo>();
+      AU.addPreserved<MachineBlockFrequencyInfo>();
+      AU.addPreservedID(MachineDominatorsID);
+      MachineFunctionPass::getAnalysisUsage(AU);
+    }
+
+    bool runOnMachineFunction(MachineFunction &MF) override;
+
+  private:
+    void InitializeSlots();
+    void ScanForSpillSlotRefs(MachineFunction &MF);
+    bool OverlapWithAssignments(LiveInterval *li, int Color) const;
+    int ColorSlot(LiveInterval *li);
+    bool ColorSlots(MachineFunction &MF);
+    void RewriteInstruction(MachineInstr *MI, SmallVectorImpl<int> &SlotMapping,
+                            MachineFunction &MF);
+    bool RemoveDeadStores(MachineBasicBlock* MBB);
+  };
+} // end anonymous namespace
+
+char StackSlotColoring::ID = 0;
+char &llvm::StackSlotColoringID = StackSlotColoring::ID;
+
+INITIALIZE_PASS_BEGIN(StackSlotColoring, "stack-slot-coloring",
+                "Stack Slot Coloring", false, false)
+INITIALIZE_PASS_DEPENDENCY(SlotIndexes)
+INITIALIZE_PASS_DEPENDENCY(LiveStacks)
+INITIALIZE_PASS_DEPENDENCY(MachineLoopInfo)
+INITIALIZE_PASS_END(StackSlotColoring, "stack-slot-coloring",
+                "Stack Slot Coloring", false, false)
+
+namespace {
+  // IntervalSorter - Comparison predicate that sort live intervals by
+  // their weight.
+  struct IntervalSorter {
+    bool operator()(LiveInterval* LHS, LiveInterval* RHS) const {
+      return LHS->weight > RHS->weight;
+    }
+  };
+}
+
+/// ScanForSpillSlotRefs - Scan all the machine instructions for spill slot
+/// references and update spill slot weights.
+void StackSlotColoring::ScanForSpillSlotRefs(MachineFunction &MF) {
+  SSRefs.resize(MFI->getObjectIndexEnd());
+
+  // FIXME: Need the equivalent of MachineRegisterInfo for frameindex operands.
+  for (MachineFunction::iterator MBBI = MF.begin(), E = MF.end();
+       MBBI != E; ++MBBI) {
+    MachineBasicBlock *MBB = &*MBBI;
+    for (MachineBasicBlock::iterator MII = MBB->begin(), EE = MBB->end();
+         MII != EE; ++MII) {
+      MachineInstr *MI = &*MII;
+      for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+        MachineOperand &MO = MI->getOperand(i);
+        if (!MO.isFI())
+          continue;
+        int FI = MO.getIndex();
+        if (FI < 0)
+          continue;
+        if (!LS->hasInterval(FI))
+          continue;
+        LiveInterval &li = LS->getInterval(FI);
+        if (!MI->isDebugValue())
+          li.weight += LiveIntervals::getSpillWeight(false, true, MBFI, MI);
+      }
+      for (MachineInstr::mmo_iterator MMOI = MI->memoperands_begin(),
+           EE = MI->memoperands_end(); MMOI != EE; ++MMOI) {
+        MachineMemOperand *MMO = *MMOI;
+        if (const FixedStackPseudoSourceValue *FSV =
+            dyn_cast_or_null<FixedStackPseudoSourceValue>(
+                MMO->getPseudoValue())) {
+          int FI = FSV->getFrameIndex();
+          if (FI >= 0)
+            SSRefs[FI].push_back(MMO);
+        }
+      }
+    }
+  }
+}
+
+/// InitializeSlots - Process all spill stack slot liveintervals and add them
+/// to a sorted (by weight) list.
+void StackSlotColoring::InitializeSlots() {
+  int LastFI = MFI->getObjectIndexEnd();
+  OrigAlignments.resize(LastFI);
+  OrigSizes.resize(LastFI);
+  AllColors.resize(LastFI);
+  UsedColors.resize(LastFI);
+  Assignments.resize(LastFI);
+
+  typedef std::iterator_traits<LiveStacks::iterator>::value_type Pair;
+  SmallVector<Pair *, 16> Intervals;
+  Intervals.reserve(LS->getNumIntervals());
+  for (auto &I : *LS)
+    Intervals.push_back(&I);
+  std::sort(Intervals.begin(), Intervals.end(),
+            [](Pair *LHS, Pair *RHS) { return LHS->first < RHS->first; });
+
+  // Gather all spill slots into a list.
+  DEBUG(dbgs() << "Spill slot intervals:\n");
+  for (auto *I : Intervals) {
+    LiveInterval &li = I->second;
+    DEBUG(li.dump());
+    int FI = TargetRegisterInfo::stackSlot2Index(li.reg);
+    if (MFI->isDeadObjectIndex(FI))
+      continue;
+    SSIntervals.push_back(&li);
+    OrigAlignments[FI] = MFI->getObjectAlignment(FI);
+    OrigSizes[FI]      = MFI->getObjectSize(FI);
+    AllColors.set(FI);
+  }
+  DEBUG(dbgs() << '\n');
+
+  // Sort them by weight.
+  std::stable_sort(SSIntervals.begin(), SSIntervals.end(), IntervalSorter());
+
+  // Get first "color".
+  NextColor = AllColors.find_first();
+}
+
+/// OverlapWithAssignments - Return true if LiveInterval overlaps with any
+/// LiveIntervals that have already been assigned to the specified color.
+bool
+StackSlotColoring::OverlapWithAssignments(LiveInterval *li, int Color) const {
+  const SmallVectorImpl<LiveInterval *> &OtherLIs = Assignments[Color];
+  for (unsigned i = 0, e = OtherLIs.size(); i != e; ++i) {
+    LiveInterval *OtherLI = OtherLIs[i];
+    if (OtherLI->overlaps(*li))
+      return true;
+  }
+  return false;
+}
+
+/// ColorSlot - Assign a "color" (stack slot) to the specified stack slot.
+///
+int StackSlotColoring::ColorSlot(LiveInterval *li) {
+  int Color = -1;
+  bool Share = false;
+  if (!DisableSharing) {
+    // Check if it's possible to reuse any of the used colors.
+    Color = UsedColors.find_first();
+    while (Color != -1) {
+      if (!OverlapWithAssignments(li, Color)) {
+        Share = true;
+        ++NumEliminated;
+        break;
+      }
+      Color = UsedColors.find_next(Color);
+    }
+  }
+
+  // Assign it to the first available color (assumed to be the best) if it's
+  // not possible to share a used color with other objects.
+  if (!Share) {
+    assert(NextColor != -1 && "No more spill slots?");
+    Color = NextColor;
+    UsedColors.set(Color);
+    NextColor = AllColors.find_next(NextColor);
+  }
+
+  // Record the assignment.
+  Assignments[Color].push_back(li);
+  int FI = TargetRegisterInfo::stackSlot2Index(li->reg);
+  DEBUG(dbgs() << "Assigning fi#" << FI << " to fi#" << Color << "\n");
+
+  // Change size and alignment of the allocated slot. If there are multiple
+  // objects sharing the same slot, then make sure the size and alignment
+  // are large enough for all.
+  unsigned Align = OrigAlignments[FI];
+  if (!Share || Align > MFI->getObjectAlignment(Color))
+    MFI->setObjectAlignment(Color, Align);
+  int64_t Size = OrigSizes[FI];
+  if (!Share || Size > MFI->getObjectSize(Color))
+    MFI->setObjectSize(Color, Size);
+  return Color;
+}
+
+/// Colorslots - Color all spill stack slots and rewrite all frameindex machine
+/// operands in the function.
+bool StackSlotColoring::ColorSlots(MachineFunction &MF) {
+  unsigned NumObjs = MFI->getObjectIndexEnd();
+  SmallVector<int, 16> SlotMapping(NumObjs, -1);
+  SmallVector<float, 16> SlotWeights(NumObjs, 0.0);
+  SmallVector<SmallVector<int, 4>, 16> RevMap(NumObjs);
+  BitVector UsedColors(NumObjs);
+
+  DEBUG(dbgs() << "Color spill slot intervals:\n");
+  bool Changed = false;
+  for (unsigned i = 0, e = SSIntervals.size(); i != e; ++i) {
+    LiveInterval *li = SSIntervals[i];
+    int SS = TargetRegisterInfo::stackSlot2Index(li->reg);
+    int NewSS = ColorSlot(li);
+    assert(NewSS >= 0 && "Stack coloring failed?");
+    SlotMapping[SS] = NewSS;
+    RevMap[NewSS].push_back(SS);
+    SlotWeights[NewSS] += li->weight;
+    UsedColors.set(NewSS);
+    Changed |= (SS != NewSS);
+  }
+
+  DEBUG(dbgs() << "\nSpill slots after coloring:\n");
+  for (unsigned i = 0, e = SSIntervals.size(); i != e; ++i) {
+    LiveInterval *li = SSIntervals[i];
+    int SS = TargetRegisterInfo::stackSlot2Index(li->reg);
+    li->weight = SlotWeights[SS];
+  }
+  // Sort them by new weight.
+  std::stable_sort(SSIntervals.begin(), SSIntervals.end(), IntervalSorter());
+
+#ifndef NDEBUG
+  for (unsigned i = 0, e = SSIntervals.size(); i != e; ++i)
+    DEBUG(SSIntervals[i]->dump());
+  DEBUG(dbgs() << '\n');
+#endif
+
+  if (!Changed)
+    return false;
+
+  // Rewrite all MachineMemOperands.
+  for (unsigned SS = 0, SE = SSRefs.size(); SS != SE; ++SS) {
+    int NewFI = SlotMapping[SS];
+    if (NewFI == -1 || (NewFI == (int)SS))
+      continue;
+
+    const PseudoSourceValue *NewSV = MF.getPSVManager().getFixedStack(NewFI);
+    SmallVectorImpl<MachineMemOperand *> &RefMMOs = SSRefs[SS];
+    for (unsigned i = 0, e = RefMMOs.size(); i != e; ++i)
+      RefMMOs[i]->setValue(NewSV);
+  }
+
+  // Rewrite all MO_FrameIndex operands.  Look for dead stores.
+  for (MachineFunction::iterator MBBI = MF.begin(), E = MF.end();
+       MBBI != E; ++MBBI) {
+    MachineBasicBlock *MBB = &*MBBI;
+    for (MachineBasicBlock::iterator MII = MBB->begin(), EE = MBB->end();
+         MII != EE; ++MII)
+      RewriteInstruction(MII, SlotMapping, MF);
+    RemoveDeadStores(MBB);
+  }
+
+  // Delete unused stack slots.
+  while (NextColor != -1) {
+    DEBUG(dbgs() << "Removing unused stack object fi#" << NextColor << "\n");
+    MFI->RemoveStackObject(NextColor);
+    NextColor = AllColors.find_next(NextColor);
+  }
+
+  return true;
+}
+
+/// RewriteInstruction - Rewrite specified instruction by replacing references
+/// to old frame index with new one.
+void StackSlotColoring::RewriteInstruction(MachineInstr *MI,
+                                           SmallVectorImpl<int> &SlotMapping,
+                                           MachineFunction &MF) {
+  // Update the operands.
+  for (unsigned i = 0, ee = MI->getNumOperands(); i != ee; ++i) {
+    MachineOperand &MO = MI->getOperand(i);
+    if (!MO.isFI())
+      continue;
+    int OldFI = MO.getIndex();
+    if (OldFI < 0)
+      continue;
+    int NewFI = SlotMapping[OldFI];
+    if (NewFI == -1 || NewFI == OldFI)
+      continue;
+    MO.setIndex(NewFI);
+  }
+
+  // The MachineMemOperands have already been updated.
+}
+
+
+/// RemoveDeadStores - Scan through a basic block and look for loads followed
+/// by stores.  If they're both using the same stack slot, then the store is
+/// definitely dead.  This could obviously be much more aggressive (consider
+/// pairs with instructions between them), but such extensions might have a
+/// considerable compile time impact.
+bool StackSlotColoring::RemoveDeadStores(MachineBasicBlock* MBB) {
+  // FIXME: This could be much more aggressive, but we need to investigate
+  // the compile time impact of doing so.
+  bool changed = false;
+
+  SmallVector<MachineInstr*, 4> toErase;
+
+  for (MachineBasicBlock::iterator I = MBB->begin(), E = MBB->end();
+       I != E; ++I) {
+    if (DCELimit != -1 && (int)NumDead >= DCELimit)
+      break;
+
+    int FirstSS, SecondSS;
+    if (TII->isStackSlotCopy(I, FirstSS, SecondSS) &&
+        FirstSS == SecondSS &&
+        FirstSS != -1) {
+      ++NumDead;
+      changed = true;
+      toErase.push_back(I);
+      continue;
+    }
+
+    MachineBasicBlock::iterator NextMI = std::next(I);
+    if (NextMI == MBB->end()) continue;
+
+    unsigned LoadReg = 0;
+    unsigned StoreReg = 0;
+    if (!(LoadReg = TII->isLoadFromStackSlot(I, FirstSS))) continue;
+    if (!(StoreReg = TII->isStoreToStackSlot(NextMI, SecondSS))) continue;
+    if (FirstSS != SecondSS || LoadReg != StoreReg || FirstSS == -1) continue;
+
+    ++NumDead;
+    changed = true;
+
+    if (NextMI->findRegisterUseOperandIdx(LoadReg, true, nullptr) != -1) {
+      ++NumDead;
+      toErase.push_back(I);
+    }
+
+    toErase.push_back(NextMI);
+    ++I;
+  }
+
+  for (SmallVectorImpl<MachineInstr *>::iterator I = toErase.begin(),
+       E = toErase.end(); I != E; ++I)
+    (*I)->eraseFromParent();
+
+  return changed;
+}
+
+
+bool StackSlotColoring::runOnMachineFunction(MachineFunction &MF) {
+  DEBUG({
+      dbgs() << "********** Stack Slot Coloring **********\n"
+             << "********** Function: " << MF.getName() << '\n';
+    });
+
+  MFI = MF.getFrameInfo();
+  TII = MF.getSubtarget().getInstrInfo();
+  LS = &getAnalysis<LiveStacks>();
+  MBFI = &getAnalysis<MachineBlockFrequencyInfo>();
+
+  bool Changed = false;
+
+  unsigned NumSlots = LS->getNumIntervals();
+  if (NumSlots == 0)
+    // Nothing to do!
+    return false;
+
+  // If there are calls to setjmp or sigsetjmp, don't perform stack slot
+  // coloring. The stack could be modified before the longjmp is executed,
+  // resulting in the wrong value being used afterwards. (See
+  // <rdar://problem/8007500>.)
+  if (MF.exposesReturnsTwice())
+    return false;
+
+  // Gather spill slot references
+  ScanForSpillSlotRefs(MF);
+  InitializeSlots();
+  Changed = ColorSlots(MF);
+
+  NextColor = -1;
+  SSIntervals.clear();
+  for (unsigned i = 0, e = SSRefs.size(); i != e; ++i)
+    SSRefs[i].clear();
+  SSRefs.clear();
+  OrigAlignments.clear();
+  OrigSizes.clear();
+  AllColors.clear();
+  UsedColors.clear();
+  for (unsigned i = 0, e = Assignments.size(); i != e; ++i)
+    Assignments[i].clear();
+  Assignments.clear();
+
+  return Changed;
+}