1 files changed, 0 insertions, 211 deletions
diff --git a/lib/CodeGen/LiveRangeShrink.cpp b/lib/CodeGen/LiveRangeShrink.cpp
deleted file mode 100644
index 00182e2c779f..000000000000
--- a/lib/CodeGen/LiveRangeShrink.cpp
+++ /dev/null
@@ -1,211 +0,0 @@
-//===-- LiveRangeShrink.cpp - Move instructions to shrink live range ------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-///===---------------------------------------------------------------------===//
-///
-/// \file
-/// This pass moves instructions close to the definition of its operands to
-/// shrink live range of the def instruction. The code motion is limited within
-/// the basic block. The moved instruction should have 1 def, and more than one
-/// uses, all of which are the only use of the def.
-///
-///===---------------------------------------------------------------------===//
-#include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/CodeGen/Passes.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/Support/Debug.h"
-
-#define DEBUG_TYPE "lrshrink"
-
-STATISTIC(NumInstrsHoistedToShrinkLiveRange,
-          "Number of insructions hoisted to shrink live range.");
-
-using namespace llvm;
-
-namespace {
-class LiveRangeShrink : public MachineFunctionPass {
-public:
-  static char ID;
-
-  LiveRangeShrink() : MachineFunctionPass(ID) {
-    initializeLiveRangeShrinkPass(*PassRegistry::getPassRegistry());
-  }
-
-  void getAnalysisUsage(AnalysisUsage &AU) const override {
-    AU.setPreservesCFG();
-    MachineFunctionPass::getAnalysisUsage(AU);
-  }
-
-  StringRef getPassName() const override { return "Live Range Shrink"; }
-
-  bool runOnMachineFunction(MachineFunction &MF) override;
-};
-} // End anonymous namespace.
-
-char LiveRangeShrink::ID = 0;
-char &llvm::LiveRangeShrinkID = LiveRangeShrink::ID;
-
-INITIALIZE_PASS(LiveRangeShrink, "lrshrink", "Live Range Shrink Pass", false,
-                false)
-namespace {
-typedef DenseMap<MachineInstr *, unsigned> InstOrderMap;
-
-/// Returns \p New if it's dominated by \p Old, otherwise return \p Old.
-/// \p M maintains a map from instruction to its dominating order that satisfies
-/// M[A] > M[B] guarantees that A is dominated by B.
-/// If \p New is not in \p M, return \p Old. Otherwise if \p Old is null, return
-/// \p New.
-MachineInstr *FindDominatedInstruction(MachineInstr &New, MachineInstr *Old,
-                                       const InstOrderMap &M) {
-  auto NewIter = M.find(&New);
-  if (NewIter == M.end())
-    return Old;
-  if (Old == nullptr)
-    return &New;
-  unsigned OrderOld = M.find(Old)->second;
-  unsigned OrderNew = NewIter->second;
-  if (OrderOld != OrderNew)
-    return OrderOld < OrderNew ? &New : Old;
-  // OrderOld == OrderNew, we need to iterate down from Old to see if it
-  // can reach New, if yes, New is dominated by Old.
-  for (MachineInstr *I = Old->getNextNode(); M.find(I)->second == OrderNew;
-       I = I->getNextNode())
-    if (I == &New)
-      return &New;
-  return Old;
-}
-
-/// Builds Instruction to its dominating order number map \p M by traversing
-/// from instruction \p Start.
-void BuildInstOrderMap(MachineBasicBlock::iterator Start, InstOrderMap &M) {
-  M.clear();
-  unsigned i = 0;
-  for (MachineInstr &I : make_range(Start, Start->getParent()->end()))
-    M[&I] = i++;
-}
-} // end anonymous namespace
-
-bool LiveRangeShrink::runOnMachineFunction(MachineFunction &MF) {
-  if (skipFunction(*MF.getFunction()))
-    return false;
-
-  MachineRegisterInfo &MRI = MF.getRegInfo();
-
-  DEBUG(dbgs() << "**** Analysing " << MF.getName() << '\n');
-
-  InstOrderMap IOM;
-  // Map from register to instruction order (value of IOM) where the
-  // register is used last. When moving instructions up, we need to
-  // make sure all its defs (including dead def) will not cross its
-  // last use when moving up.
-  DenseMap<unsigned, unsigned> UseMap;
-
-  for (MachineBasicBlock &MBB : MF) {
-    if (MBB.empty())
-      continue;
-    bool SawStore = false;
-    BuildInstOrderMap(MBB.begin(), IOM);
-    UseMap.clear();
-
-    for (MachineBasicBlock::iterator Next = MBB.begin(); Next != MBB.end();) {
-      MachineInstr &MI = *Next;
-      ++Next;
-      if (MI.isPHI() || MI.isDebugValue())
-        continue;
-      if (MI.mayStore())
-        SawStore = true;
-
-      unsigned CurrentOrder = IOM[&MI];
-      unsigned Barrier = 0;
-      for (const MachineOperand &MO : MI.operands()) {
-        if (!MO.isReg() || MO.isDebug())
-          continue;
-        if (MO.isUse())
-          UseMap[MO.getReg()] = CurrentOrder;
-        else if (MO.isDead() && UseMap.count(MO.getReg()))
-          // Barrier is the last instruction where MO get used. MI should not
-          // be moved above Barrier.
-          Barrier = std::max(Barrier, UseMap[MO.getReg()]);
-      }
-
-      if (!MI.isSafeToMove(nullptr, SawStore)) {
-        // If MI has side effects, it should become a barrier for code motion.
-        // IOM is rebuild from the next instruction to prevent later
-        // instructions from being moved before this MI.
-        if (MI.hasUnmodeledSideEffects() && Next != MBB.end()) {
-          BuildInstOrderMap(Next, IOM);
-          SawStore = false;
-        }
-        continue;
-      }
-
-      const MachineOperand *DefMO = nullptr;
-      MachineInstr *Insert = nullptr;
-
-      // Number of live-ranges that will be shortened. We do not count
-      // live-ranges that are defined by a COPY as it could be coalesced later.
-      unsigned NumEligibleUse = 0;
-
-      for (const MachineOperand &MO : MI.operands()) {
-        if (!MO.isReg() || MO.isDead() || MO.isDebug())
-          continue;
-        unsigned Reg = MO.getReg();
-        // Do not move the instruction if it def/uses a physical register,
-        // unless it is a constant physical register.
-        if (TargetRegisterInfo::isPhysicalRegister(Reg) &&
-            !MRI.isConstantPhysReg(Reg)) {
-          Insert = nullptr;
-          break;
-        }
-        if (MO.isDef()) {
-          // Do not move if there is more than one def.
-          if (DefMO) {
-            Insert = nullptr;
-            break;
-          }
-          DefMO = &MO;
-        } else if (MRI.hasOneNonDBGUse(Reg) && MRI.hasOneDef(Reg)) {
-          MachineInstr &DefInstr = *MRI.def_instr_begin(Reg);
-          if (!DefInstr.isCopy())
-            NumEligibleUse++;
-          Insert = FindDominatedInstruction(DefInstr, Insert, IOM);
-        } else {
-          Insert = nullptr;
-          break;
-        }
-      }
-      // Move the instruction when # of shrunk live range > 1.
-      if (DefMO && Insert && NumEligibleUse > 1 && Barrier <= IOM[Insert]) {
-        MachineBasicBlock::iterator I = std::next(Insert->getIterator());
-        // Skip all the PHI and debug instructions.
-        while (I != MBB.end() && (I->isPHI() || I->isDebugValue()))
-          I = std::next(I);
-        if (I == MI.getIterator())
-          continue;
-
-        // Update the dominator order to be the same as the insertion point.
-        // We do this to maintain a non-decreasing order without need to update
-        // all instruction orders after the insertion point.
-        unsigned NewOrder = IOM[&*I];
-        IOM[&MI] = NewOrder;
-        NumInstrsHoistedToShrinkLiveRange++;
-
-        // Find MI's debug value following MI.
-        MachineBasicBlock::iterator EndIter = std::next(MI.getIterator());
-        if (MI.getOperand(0).isReg())
-          for (; EndIter != MBB.end() && EndIter->isDebugValue() &&
-                 EndIter->getOperand(0).isReg() &&
-                 EndIter->getOperand(0).getReg() == MI.getOperand(0).getReg();
-               ++EndIter, ++Next)
-            IOM[&*EndIter] = NewOrder;
-        MBB.splice(I, &MBB, MI.getIterator(), EndIter);
-      }
-    }
-  }
-  return false;
-}