vendor/llvm/llvm-r72732

1 files changed, 269 insertions, 0 deletions

diff --git a/lib/CodeGen/VirtRegMap.cpp b/lib/CodeGen/VirtRegMap.cpp
new file mode 100644
index 000000000000..29637b954f0b
--- /dev/null
+++ b/lib/CodeGen/VirtRegMap.cpp
@@ -0,0 +1,269 @@
+//===-- llvm/CodeGen/VirtRegMap.cpp - Virtual Register Map ----------------===//
+//
+//                     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 VirtRegMap class.
+//
+// It also contains implementations of the the Spiller interface, which, given a
+// virtual register map and a machine function, eliminates all virtual
+// references by replacing them with physical register references - adding spill
+// code as necessary.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "virtregmap"
+#include "VirtRegMap.h"
+#include "llvm/Function.h"
+#include "llvm/CodeGen/LiveIntervalAnalysis.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/ADT/BitVector.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/DepthFirstIterator.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallSet.h"
+#include <algorithm>
+using namespace llvm;
+
+STATISTIC(NumSpills  , "Number of register spills");
+
+//===----------------------------------------------------------------------===//
+//  VirtRegMap implementation
+//===----------------------------------------------------------------------===//
+
+char VirtRegMap::ID = 0;
+
+static RegisterPass<VirtRegMap>
+X("virtregmap", "Virtual Register Map");
+
+bool VirtRegMap::runOnMachineFunction(MachineFunction &mf) {
+  TII = mf.getTarget().getInstrInfo();
+  TRI = mf.getTarget().getRegisterInfo();
+  MF = &mf;
+  
+  ReMatId = MAX_STACK_SLOT+1;
+  LowSpillSlot = HighSpillSlot = NO_STACK_SLOT;
+  
+  Virt2PhysMap.clear();
+  Virt2StackSlotMap.clear();
+  Virt2ReMatIdMap.clear();
+  Virt2SplitMap.clear();
+  Virt2SplitKillMap.clear();
+  ReMatMap.clear();
+  ImplicitDefed.clear();
+  SpillSlotToUsesMap.clear();
+  MI2VirtMap.clear();
+  SpillPt2VirtMap.clear();
+  RestorePt2VirtMap.clear();
+  EmergencySpillMap.clear();
+  EmergencySpillSlots.clear();
+  
+  SpillSlotToUsesMap.resize(8);
+  ImplicitDefed.resize(MF->getRegInfo().getLastVirtReg()+1-
+                       TargetRegisterInfo::FirstVirtualRegister);
+
+  allocatableRCRegs.clear();
+  for (TargetRegisterInfo::regclass_iterator I = TRI->regclass_begin(),
+         E = TRI->regclass_end(); I != E; ++I)
+    allocatableRCRegs.insert(std::make_pair(*I,
+                                            TRI->getAllocatableSet(mf, *I)));
+
+  grow();
+  
+  return false;
+}
+
+void VirtRegMap::grow() {
+  unsigned LastVirtReg = MF->getRegInfo().getLastVirtReg();
+  Virt2PhysMap.grow(LastVirtReg);
+  Virt2StackSlotMap.grow(LastVirtReg);
+  Virt2ReMatIdMap.grow(LastVirtReg);
+  Virt2SplitMap.grow(LastVirtReg);
+  Virt2SplitKillMap.grow(LastVirtReg);
+  ReMatMap.grow(LastVirtReg);
+  ImplicitDefed.resize(LastVirtReg-TargetRegisterInfo::FirstVirtualRegister+1);
+}
+
+int VirtRegMap::assignVirt2StackSlot(unsigned virtReg) {
+  assert(TargetRegisterInfo::isVirtualRegister(virtReg));
+  assert(Virt2StackSlotMap[virtReg] == NO_STACK_SLOT &&
+         "attempt to assign stack slot to already spilled register");
+  const TargetRegisterClass* RC = MF->getRegInfo().getRegClass(virtReg);
+  int SS = MF->getFrameInfo()->CreateStackObject(RC->getSize(),
+                                                RC->getAlignment());
+  if (LowSpillSlot == NO_STACK_SLOT)
+    LowSpillSlot = SS;
+  if (HighSpillSlot == NO_STACK_SLOT || SS > HighSpillSlot)
+    HighSpillSlot = SS;
+  unsigned Idx = SS-LowSpillSlot;
+  while (Idx >= SpillSlotToUsesMap.size())
+    SpillSlotToUsesMap.resize(SpillSlotToUsesMap.size()*2);
+  Virt2StackSlotMap[virtReg] = SS;
+  ++NumSpills;
+  return SS;
+}
+
+void VirtRegMap::assignVirt2StackSlot(unsigned virtReg, int SS) {
+  assert(TargetRegisterInfo::isVirtualRegister(virtReg));
+  assert(Virt2StackSlotMap[virtReg] == NO_STACK_SLOT &&
+         "attempt to assign stack slot to already spilled register");
+  assert((SS >= 0 ||
+          (SS >= MF->getFrameInfo()->getObjectIndexBegin())) &&
+         "illegal fixed frame index");
+  Virt2StackSlotMap[virtReg] = SS;
+}
+
+int VirtRegMap::assignVirtReMatId(unsigned virtReg) {
+  assert(TargetRegisterInfo::isVirtualRegister(virtReg));
+  assert(Virt2ReMatIdMap[virtReg] == NO_STACK_SLOT &&
+         "attempt to assign re-mat id to already spilled register");
+  Virt2ReMatIdMap[virtReg] = ReMatId;
+  return ReMatId++;
+}
+
+void VirtRegMap::assignVirtReMatId(unsigned virtReg, int id) {
+  assert(TargetRegisterInfo::isVirtualRegister(virtReg));
+  assert(Virt2ReMatIdMap[virtReg] == NO_STACK_SLOT &&
+         "attempt to assign re-mat id to already spilled register");
+  Virt2ReMatIdMap[virtReg] = id;
+}
+
+int VirtRegMap::getEmergencySpillSlot(const TargetRegisterClass *RC) {
+  std::map<const TargetRegisterClass*, int>::iterator I =
+    EmergencySpillSlots.find(RC);
+  if (I != EmergencySpillSlots.end())
+    return I->second;
+  int SS = MF->getFrameInfo()->CreateStackObject(RC->getSize(),
+                                                RC->getAlignment());
+  if (LowSpillSlot == NO_STACK_SLOT)
+    LowSpillSlot = SS;
+  if (HighSpillSlot == NO_STACK_SLOT || SS > HighSpillSlot)
+    HighSpillSlot = SS;
+  EmergencySpillSlots[RC] = SS;
+  return SS;
+}
+
+void VirtRegMap::addSpillSlotUse(int FI, MachineInstr *MI) {
+  if (!MF->getFrameInfo()->isFixedObjectIndex(FI)) {
+    // If FI < LowSpillSlot, this stack reference was produced by
+    // instruction selection and is not a spill
+    if (FI >= LowSpillSlot) {
+      assert(FI >= 0 && "Spill slot index should not be negative!");
+      assert((unsigned)FI-LowSpillSlot < SpillSlotToUsesMap.size()
+             && "Invalid spill slot");
+      SpillSlotToUsesMap[FI-LowSpillSlot].insert(MI);
+    }
+  }
+}
+
+void VirtRegMap::virtFolded(unsigned VirtReg, MachineInstr *OldMI,
+                            MachineInstr *NewMI, ModRef MRInfo) {
+  // Move previous memory references folded to new instruction.
+  MI2VirtMapTy::iterator IP = MI2VirtMap.lower_bound(NewMI);
+  for (MI2VirtMapTy::iterator I = MI2VirtMap.lower_bound(OldMI),
+         E = MI2VirtMap.end(); I != E && I->first == OldMI; ) {
+    MI2VirtMap.insert(IP, std::make_pair(NewMI, I->second));
+    MI2VirtMap.erase(I++);
+  }
+
+  // add new memory reference
+  MI2VirtMap.insert(IP, std::make_pair(NewMI, std::make_pair(VirtReg, MRInfo)));
+}
+
+void VirtRegMap::virtFolded(unsigned VirtReg, MachineInstr *MI, ModRef MRInfo) {
+  MI2VirtMapTy::iterator IP = MI2VirtMap.lower_bound(MI);
+  MI2VirtMap.insert(IP, std::make_pair(MI, std::make_pair(VirtReg, MRInfo)));
+}
+
+void VirtRegMap::RemoveMachineInstrFromMaps(MachineInstr *MI) {
+  for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
+    MachineOperand &MO = MI->getOperand(i);
+    if (!MO.isFI())
+      continue;
+    int FI = MO.getIndex();
+    if (MF->getFrameInfo()->isFixedObjectIndex(FI))
+      continue;
+    // This stack reference was produced by instruction selection and
+    // is not a spill
+    if (FI < LowSpillSlot)
+      continue;
+    assert((unsigned)FI-LowSpillSlot < SpillSlotToUsesMap.size()
+           && "Invalid spill slot");
+    SpillSlotToUsesMap[FI-LowSpillSlot].erase(MI);
+  }
+  MI2VirtMap.erase(MI);
+  SpillPt2VirtMap.erase(MI);
+  RestorePt2VirtMap.erase(MI);
+  EmergencySpillMap.erase(MI);
+}
+
+/// FindUnusedRegisters - Gather a list of allocatable registers that
+/// have not been allocated to any virtual register.
+bool VirtRegMap::FindUnusedRegisters(const TargetRegisterInfo *TRI,
+                                     LiveIntervals* LIs) {
+  unsigned NumRegs = TRI->getNumRegs();
+  UnusedRegs.reset();
+  UnusedRegs.resize(NumRegs);
+
+  BitVector Used(NumRegs);
+  for (unsigned i = TargetRegisterInfo::FirstVirtualRegister,
+         e = MF->getRegInfo().getLastVirtReg(); i <= e; ++i)
+    if (Virt2PhysMap[i] != (unsigned)VirtRegMap::NO_PHYS_REG)
+      Used.set(Virt2PhysMap[i]);
+
+  BitVector Allocatable = TRI->getAllocatableSet(*MF);
+  bool AnyUnused = false;
+  for (unsigned Reg = 1; Reg < NumRegs; ++Reg) {
+    if (Allocatable[Reg] && !Used[Reg] && !LIs->hasInterval(Reg)) {
+      bool ReallyUnused = true;
+      for (const unsigned *AS = TRI->getAliasSet(Reg); *AS; ++AS) {
+        if (Used[*AS] || LIs->hasInterval(*AS)) {
+          ReallyUnused = false;
+          break;
+        }
+      }
+      if (ReallyUnused) {
+        AnyUnused = true;
+        UnusedRegs.set(Reg);
+      }
+    }
+  }
+
+  return AnyUnused;
+}
+
+void VirtRegMap::print(std::ostream &OS, const Module* M) const {
+  const TargetRegisterInfo* TRI = MF->getTarget().getRegisterInfo();
+
+  OS << "********** REGISTER MAP **********\n";
+  for (unsigned i = TargetRegisterInfo::FirstVirtualRegister,
+         e = MF->getRegInfo().getLastVirtReg(); i <= e; ++i) {
+    if (Virt2PhysMap[i] != (unsigned)VirtRegMap::NO_PHYS_REG)
+      OS << "[reg" << i << " -> " << TRI->getName(Virt2PhysMap[i])
+         << "]\n";
+  }
+
+  for (unsigned i = TargetRegisterInfo::FirstVirtualRegister,
+         e = MF->getRegInfo().getLastVirtReg(); i <= e; ++i)
+    if (Virt2StackSlotMap[i] != VirtRegMap::NO_STACK_SLOT)
+      OS << "[reg" << i << " -> fi#" << Virt2StackSlotMap[i] << "]\n";
+  OS << '\n';
+}
+
+void VirtRegMap::dump() const {
+  print(cerr);
+}