//
// The LLVM Compiler Infrastructure
//
-// This file was developed by the LLVM research group and is distributed under
-// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
-// This file implements a virtual register map. This maps virtual
-// registers to physical registers and virtual registers to stack
-// slots. It is created and updated by a register allocator and then
-// used by a machine code rewriter that adds spill code and rewrites
-// virtual into physical register references.
+// This file implements a virtual register map. This maps virtual registers to
+// physical registers and virtual registers to stack slots. It is created and
+// updated by a register allocator and then used by a machine code rewriter that
+// adds spill code and rewrites virtual into physical register references.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_VIRTREGMAP_H
#define LLVM_CODEGEN_VIRTREGMAP_H
-#include "llvm/CodeGen/MachineFunction.h"
-#include "llvm/CodeGen/SSARegMap.h"
-#include <climits>
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/LiveInterval.h"
+#include "llvm/Target/TargetRegisterInfo.h"
+#include "llvm/ADT/BitVector.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/IndexedMap.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallVector.h"
+#include <map>
namespace llvm {
+ class LiveIntervals;
+ class MachineInstr;
+ class MachineFunction;
+ class MachineRegisterInfo;
+ class TargetInstrInfo;
+ class TargetRegisterInfo;
+ class raw_ostream;
- class VirtRegMap {
- public:
- typedef std::vector<unsigned> Virt2PhysMap;
- typedef std::vector<int> Virt2StackSlotMap;
-
- private:
- MachineFunction* mf_;
- Virt2PhysMap v2pMap_;
- Virt2StackSlotMap v2ssMap_;
-
- // do not implement
- VirtRegMap(const VirtRegMap& rhs);
- const VirtRegMap& operator=(const VirtRegMap& rhs);
-
- static unsigned toIndex(unsigned virtReg) {
- return virtReg - MRegisterInfo::FirstVirtualRegister;
- }
- static unsigned fromIndex(unsigned index) {
- return index + MRegisterInfo::FirstVirtualRegister;
- }
-
- enum {
- NO_PHYS_REG = 0,
- NO_STACK_SLOT = INT_MAX
- };
-
- public:
- VirtRegMap(MachineFunction& mf)
- : mf_(&mf),
- v2pMap_(mf.getSSARegMap()->getNumVirtualRegs(), NO_PHYS_REG),
- v2ssMap_(mf.getSSARegMap()->getNumVirtualRegs(), NO_STACK_SLOT) {
- }
-
- bool hasPhys(unsigned virtReg) const {
- return getPhys(virtReg) != NO_PHYS_REG;
- }
-
- unsigned getPhys(unsigned virtReg) const {
- assert(MRegisterInfo::isVirtualRegister(virtReg));
- return v2pMap_[toIndex(virtReg)];
- }
-
- void assignVirt2Phys(unsigned virtReg, unsigned physReg) {
- assert(MRegisterInfo::isVirtualRegister(virtReg) &&
- MRegisterInfo::isPhysicalRegister(physReg));
- assert(v2pMap_[toIndex(virtReg)] == NO_PHYS_REG &&
- "attempt to assign physical register to already mapped "
- "virtual register");
- v2pMap_[toIndex(virtReg)] = physReg;
- }
-
- void clearVirtReg(unsigned virtReg) {
- assert(MRegisterInfo::isVirtualRegister(virtReg));
- assert(v2pMap_[toIndex(virtReg)] != NO_PHYS_REG &&
- "attempt to clear a not assigned virtual register");
- v2pMap_[toIndex(virtReg)] = NO_PHYS_REG;
- }
-
- bool hasStackSlot(unsigned virtReg) const {
- return getStackSlot(virtReg) != NO_STACK_SLOT;
- }
-
- int getStackSlot(unsigned virtReg) const {
- assert(MRegisterInfo::isVirtualRegister(virtReg));
- return v2ssMap_[toIndex(virtReg)];
- }
-
- int assignVirt2StackSlot(unsigned virtReg);
-
- friend std::ostream& operator<<(std::ostream& os, const VirtRegMap& li);
+ class VirtRegMap : public MachineFunctionPass {
+ public:
+ enum {
+ NO_PHYS_REG = 0,
+ NO_STACK_SLOT = (1L << 30)-1,
+ MAX_STACK_SLOT = (1L << 18)-1
};
- std::ostream& operator<<(std::ostream& os, const VirtRegMap& li);
+ enum ModRef { isRef = 1, isMod = 2, isModRef = 3 };
+ typedef std::multimap<MachineInstr*,
+ std::pair<unsigned, ModRef> > MI2VirtMapTy;
- void eliminateVirtRegs(MachineFunction& mf, const VirtRegMap& vrm);
+ private:
+ MachineRegisterInfo *MRI;
+ const TargetInstrInfo *TII;
+ const TargetRegisterInfo *TRI;
+ MachineFunction *MF;
+ DenseMap<const TargetRegisterClass*, BitVector> allocatableRCRegs;
+
+ /// Virt2PhysMap - This is a virtual to physical register
+ /// mapping. Each virtual register is required to have an entry in
+ /// it; even spilled virtual registers (the register mapped to a
+ /// spilled register is the temporary used to load it from the
+ /// stack).
+ IndexedMap<unsigned, VirtReg2IndexFunctor> Virt2PhysMap;
+
+ /// Virt2StackSlotMap - This is virtual register to stack slot
+ /// mapping. Each spilled virtual register has an entry in it
+ /// which corresponds to the stack slot this register is spilled
+ /// at.
+ IndexedMap<int, VirtReg2IndexFunctor> Virt2StackSlotMap;
+
+ /// Virt2ReMatIdMap - This is virtual register to rematerialization id
+ /// mapping. Each spilled virtual register that should be remat'd has an
+ /// entry in it which corresponds to the remat id.
+ IndexedMap<int, VirtReg2IndexFunctor> Virt2ReMatIdMap;
+
+ /// Virt2SplitMap - This is virtual register to splitted virtual register
+ /// mapping.
+ IndexedMap<unsigned, VirtReg2IndexFunctor> Virt2SplitMap;
+
+ /// Virt2SplitKillMap - This is splitted virtual register to its last use
+ /// (kill) index mapping.
+ IndexedMap<SlotIndex> Virt2SplitKillMap;
+
+ /// ReMatMap - This is virtual register to re-materialized instruction
+ /// mapping. Each virtual register whose definition is going to be
+ /// re-materialized has an entry in it.
+ IndexedMap<MachineInstr*, VirtReg2IndexFunctor> ReMatMap;
+
+ /// MI2VirtMap - This is MachineInstr to virtual register
+ /// mapping. In the case of memory spill code being folded into
+ /// instructions, we need to know which virtual register was
+ /// read/written by this instruction.
+ MI2VirtMapTy MI2VirtMap;
+
+ /// SpillPt2VirtMap - This records the virtual registers which should
+ /// be spilled right after the MachineInstr due to live interval
+ /// splitting.
+ std::map<MachineInstr*, std::vector<std::pair<unsigned,bool> > >
+ SpillPt2VirtMap;
+
+ /// RestorePt2VirtMap - This records the virtual registers which should
+ /// be restored right before the MachineInstr due to live interval
+ /// splitting.
+ std::map<MachineInstr*, std::vector<unsigned> > RestorePt2VirtMap;
+
+ /// EmergencySpillMap - This records the physical registers that should
+ /// be spilled / restored around the MachineInstr since the register
+ /// allocator has run out of registers.
+ std::map<MachineInstr*, std::vector<unsigned> > EmergencySpillMap;
+
+ /// EmergencySpillSlots - This records emergency spill slots used to
+ /// spill physical registers when the register allocator runs out of
+ /// registers. Ideally only one stack slot is used per function per
+ /// register class.
+ std::map<const TargetRegisterClass*, int> EmergencySpillSlots;
+
+ /// ReMatId - Instead of assigning a stack slot to a to be rematerialized
+ /// virtual register, an unique id is being assigned. This keeps track of
+ /// the highest id used so far. Note, this starts at (1<<18) to avoid
+ /// conflicts with stack slot numbers.
+ int ReMatId;
+
+ /// LowSpillSlot, HighSpillSlot - Lowest and highest spill slot indexes.
+ int LowSpillSlot, HighSpillSlot;
+
+ /// SpillSlotToUsesMap - Records uses for each register spill slot.
+ SmallVector<SmallPtrSet<MachineInstr*, 4>, 8> SpillSlotToUsesMap;
+
+ /// ImplicitDefed - One bit for each virtual register. If set it indicates
+ /// the register is implicitly defined.
+ BitVector ImplicitDefed;
+
+ /// UnusedRegs - A list of physical registers that have not been used.
+ BitVector UnusedRegs;
+
+ VirtRegMap(const VirtRegMap&); // DO NOT IMPLEMENT
+ void operator=(const VirtRegMap&); // DO NOT IMPLEMENT
+
+ public:
+ static char ID;
+ VirtRegMap() : MachineFunctionPass(&ID), Virt2PhysMap(NO_PHYS_REG),
+ Virt2StackSlotMap(NO_STACK_SLOT),
+ Virt2ReMatIdMap(NO_STACK_SLOT), Virt2SplitMap(0),
+ Virt2SplitKillMap(SlotIndex()), ReMatMap(NULL),
+ ReMatId(MAX_STACK_SLOT+1),
+ LowSpillSlot(NO_STACK_SLOT), HighSpillSlot(NO_STACK_SLOT) { }
+ virtual bool runOnMachineFunction(MachineFunction &MF);
+
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.setPreservesAll();
+ MachineFunctionPass::getAnalysisUsage(AU);
+ }
+
+ void grow();
+
+ /// @brief returns true if the specified virtual register is
+ /// mapped to a physical register
+ bool hasPhys(unsigned virtReg) const {
+ return getPhys(virtReg) != NO_PHYS_REG;
+ }
+
+ /// @brief returns the physical register mapped to the specified
+ /// virtual register
+ unsigned getPhys(unsigned virtReg) const {
+ assert(TargetRegisterInfo::isVirtualRegister(virtReg));
+ return Virt2PhysMap[virtReg];
+ }
+
+ /// @brief creates a mapping for the specified virtual register to
+ /// the specified physical register
+ void assignVirt2Phys(unsigned virtReg, unsigned physReg) {
+ assert(TargetRegisterInfo::isVirtualRegister(virtReg) &&
+ TargetRegisterInfo::isPhysicalRegister(physReg));
+ assert(Virt2PhysMap[virtReg] == NO_PHYS_REG &&
+ "attempt to assign physical register to already mapped "
+ "virtual register");
+ Virt2PhysMap[virtReg] = physReg;
+ }
+
+ /// @brief clears the specified virtual register's, physical
+ /// register mapping
+ void clearVirt(unsigned virtReg) {
+ assert(TargetRegisterInfo::isVirtualRegister(virtReg));
+ assert(Virt2PhysMap[virtReg] != NO_PHYS_REG &&
+ "attempt to clear a not assigned virtual register");
+ Virt2PhysMap[virtReg] = NO_PHYS_REG;
+ }
+
+ /// @brief clears all virtual to physical register mappings
+ void clearAllVirt() {
+ Virt2PhysMap.clear();
+ grow();
+ }
+
+ /// @brief returns the register allocation preference.
+ unsigned getRegAllocPref(unsigned virtReg);
+
+ /// @brief records virtReg is a split live interval from SReg.
+ void setIsSplitFromReg(unsigned virtReg, unsigned SReg) {
+ Virt2SplitMap[virtReg] = SReg;
+ }
+
+ /// @brief returns the live interval virtReg is split from.
+ unsigned getPreSplitReg(unsigned virtReg) {
+ return Virt2SplitMap[virtReg];
+ }
+
+ /// @brief returns true if the specified virtual register is not
+ /// mapped to a stack slot or rematerialized.
+ bool isAssignedReg(unsigned virtReg) const {
+ if (getStackSlot(virtReg) == NO_STACK_SLOT &&
+ getReMatId(virtReg) == NO_STACK_SLOT)
+ return true;
+ // Split register can be assigned a physical register as well as a
+ // stack slot or remat id.
+ return (Virt2SplitMap[virtReg] && Virt2PhysMap[virtReg] != NO_PHYS_REG);
+ }
+
+ /// @brief returns the stack slot mapped to the specified virtual
+ /// register
+ int getStackSlot(unsigned virtReg) const {
+ assert(TargetRegisterInfo::isVirtualRegister(virtReg));
+ return Virt2StackSlotMap[virtReg];
+ }
+
+ /// @brief returns the rematerialization id mapped to the specified virtual
+ /// register
+ int getReMatId(unsigned virtReg) const {
+ assert(TargetRegisterInfo::isVirtualRegister(virtReg));
+ return Virt2ReMatIdMap[virtReg];
+ }
+
+ /// @brief create a mapping for the specifed virtual register to
+ /// the next available stack slot
+ int assignVirt2StackSlot(unsigned virtReg);
+ /// @brief create a mapping for the specified virtual register to
+ /// the specified stack slot
+ void assignVirt2StackSlot(unsigned virtReg, int frameIndex);
+
+ /// @brief assign an unique re-materialization id to the specified
+ /// virtual register.
+ int assignVirtReMatId(unsigned virtReg);
+ /// @brief assign an unique re-materialization id to the specified
+ /// virtual register.
+ void assignVirtReMatId(unsigned virtReg, int id);
+
+ /// @brief returns true if the specified virtual register is being
+ /// re-materialized.
+ bool isReMaterialized(unsigned virtReg) const {
+ return ReMatMap[virtReg] != NULL;
+ }
+
+ /// @brief returns the original machine instruction being re-issued
+ /// to re-materialize the specified virtual register.
+ MachineInstr *getReMaterializedMI(unsigned virtReg) const {
+ return ReMatMap[virtReg];
+ }
+
+ /// @brief records the specified virtual register will be
+ /// re-materialized and the original instruction which will be re-issed
+ /// for this purpose. If parameter all is true, then all uses of the
+ /// registers are rematerialized and it's safe to delete the definition.
+ void setVirtIsReMaterialized(unsigned virtReg, MachineInstr *def) {
+ ReMatMap[virtReg] = def;
+ }
+
+ /// @brief record the last use (kill) of a split virtual register.
+ void addKillPoint(unsigned virtReg, SlotIndex index) {
+ Virt2SplitKillMap[virtReg] = index;
+ }
+
+ SlotIndex getKillPoint(unsigned virtReg) const {
+ return Virt2SplitKillMap[virtReg];
+ }
+
+ /// @brief remove the last use (kill) of a split virtual register.
+ void removeKillPoint(unsigned virtReg) {
+ Virt2SplitKillMap[virtReg] = SlotIndex();
+ }
+
+ /// @brief returns true if the specified MachineInstr is a spill point.
+ bool isSpillPt(MachineInstr *Pt) const {
+ return SpillPt2VirtMap.find(Pt) != SpillPt2VirtMap.end();
+ }
+
+ /// @brief returns the virtual registers that should be spilled due to
+ /// splitting right after the specified MachineInstr.
+ std::vector<std::pair<unsigned,bool> > &getSpillPtSpills(MachineInstr *Pt) {
+ return SpillPt2VirtMap[Pt];
+ }
+
+ /// @brief records the specified MachineInstr as a spill point for virtReg.
+ void addSpillPoint(unsigned virtReg, bool isKill, MachineInstr *Pt) {
+ std::map<MachineInstr*, std::vector<std::pair<unsigned,bool> > >::iterator
+ I = SpillPt2VirtMap.find(Pt);
+ if (I != SpillPt2VirtMap.end())
+ I->second.push_back(std::make_pair(virtReg, isKill));
+ else {
+ std::vector<std::pair<unsigned,bool> > Virts;
+ Virts.push_back(std::make_pair(virtReg, isKill));
+ SpillPt2VirtMap.insert(std::make_pair(Pt, Virts));
+ }
+ }
+
+ /// @brief - transfer spill point information from one instruction to
+ /// another.
+ void transferSpillPts(MachineInstr *Old, MachineInstr *New) {
+ std::map<MachineInstr*, std::vector<std::pair<unsigned,bool> > >::iterator
+ I = SpillPt2VirtMap.find(Old);
+ if (I == SpillPt2VirtMap.end())
+ return;
+ while (!I->second.empty()) {
+ unsigned virtReg = I->second.back().first;
+ bool isKill = I->second.back().second;
+ I->second.pop_back();
+ addSpillPoint(virtReg, isKill, New);
+ }
+ SpillPt2VirtMap.erase(I);
+ }
+
+ /// @brief returns true if the specified MachineInstr is a restore point.
+ bool isRestorePt(MachineInstr *Pt) const {
+ return RestorePt2VirtMap.find(Pt) != RestorePt2VirtMap.end();
+ }
+
+ /// @brief returns the virtual registers that should be restoreed due to
+ /// splitting right after the specified MachineInstr.
+ std::vector<unsigned> &getRestorePtRestores(MachineInstr *Pt) {
+ return RestorePt2VirtMap[Pt];
+ }
+
+ /// @brief records the specified MachineInstr as a restore point for virtReg.
+ void addRestorePoint(unsigned virtReg, MachineInstr *Pt) {
+ std::map<MachineInstr*, std::vector<unsigned> >::iterator I =
+ RestorePt2VirtMap.find(Pt);
+ if (I != RestorePt2VirtMap.end())
+ I->second.push_back(virtReg);
+ else {
+ std::vector<unsigned> Virts;
+ Virts.push_back(virtReg);
+ RestorePt2VirtMap.insert(std::make_pair(Pt, Virts));
+ }
+ }
+
+ /// @brief - transfer restore point information from one instruction to
+ /// another.
+ void transferRestorePts(MachineInstr *Old, MachineInstr *New) {
+ std::map<MachineInstr*, std::vector<unsigned> >::iterator I =
+ RestorePt2VirtMap.find(Old);
+ if (I == RestorePt2VirtMap.end())
+ return;
+ while (!I->second.empty()) {
+ unsigned virtReg = I->second.back();
+ I->second.pop_back();
+ addRestorePoint(virtReg, New);
+ }
+ RestorePt2VirtMap.erase(I);
+ }
+
+ /// @brief records that the specified physical register must be spilled
+ /// around the specified machine instr.
+ void addEmergencySpill(unsigned PhysReg, MachineInstr *MI) {
+ if (EmergencySpillMap.find(MI) != EmergencySpillMap.end())
+ EmergencySpillMap[MI].push_back(PhysReg);
+ else {
+ std::vector<unsigned> PhysRegs;
+ PhysRegs.push_back(PhysReg);
+ EmergencySpillMap.insert(std::make_pair(MI, PhysRegs));
+ }
+ }
+
+ /// @brief returns true if one or more physical registers must be spilled
+ /// around the specified instruction.
+ bool hasEmergencySpills(MachineInstr *MI) const {
+ return EmergencySpillMap.find(MI) != EmergencySpillMap.end();
+ }
+
+ /// @brief returns the physical registers to be spilled and restored around
+ /// the instruction.
+ std::vector<unsigned> &getEmergencySpills(MachineInstr *MI) {
+ return EmergencySpillMap[MI];
+ }
+
+ /// @brief - transfer emergency spill information from one instruction to
+ /// another.
+ void transferEmergencySpills(MachineInstr *Old, MachineInstr *New) {
+ std::map<MachineInstr*,std::vector<unsigned> >::iterator I =
+ EmergencySpillMap.find(Old);
+ if (I == EmergencySpillMap.end())
+ return;
+ while (!I->second.empty()) {
+ unsigned virtReg = I->second.back();
+ I->second.pop_back();
+ addEmergencySpill(virtReg, New);
+ }
+ EmergencySpillMap.erase(I);
+ }
+
+ /// @brief return or get a emergency spill slot for the register class.
+ int getEmergencySpillSlot(const TargetRegisterClass *RC);
+
+ /// @brief Return lowest spill slot index.
+ int getLowSpillSlot() const {
+ return LowSpillSlot;
+ }
+
+ /// @brief Return highest spill slot index.
+ int getHighSpillSlot() const {
+ return HighSpillSlot;
+ }
+
+ /// @brief Records a spill slot use.
+ void addSpillSlotUse(int FrameIndex, MachineInstr *MI);
+
+ /// @brief Returns true if spill slot has been used.
+ bool isSpillSlotUsed(int FrameIndex) const {
+ assert(FrameIndex >= 0 && "Spill slot index should not be negative!");
+ return !SpillSlotToUsesMap[FrameIndex-LowSpillSlot].empty();
+ }
+
+ /// @brief Mark the specified register as being implicitly defined.
+ void setIsImplicitlyDefined(unsigned VirtReg) {
+ ImplicitDefed.set(VirtReg-TargetRegisterInfo::FirstVirtualRegister);
+ }
+
+ /// @brief Returns true if the virtual register is implicitly defined.
+ bool isImplicitlyDefined(unsigned VirtReg) const {
+ return ImplicitDefed[VirtReg-TargetRegisterInfo::FirstVirtualRegister];
+ }
+
+ /// @brief Updates information about the specified virtual register's value
+ /// folded into newMI machine instruction.
+ void virtFolded(unsigned VirtReg, MachineInstr *OldMI, MachineInstr *NewMI,
+ ModRef MRInfo);
+
+ /// @brief Updates information about the specified virtual register's value
+ /// folded into the specified machine instruction.
+ void virtFolded(unsigned VirtReg, MachineInstr *MI, ModRef MRInfo);
+
+ /// @brief returns the virtual registers' values folded in memory
+ /// operands of this instruction
+ std::pair<MI2VirtMapTy::const_iterator, MI2VirtMapTy::const_iterator>
+ getFoldedVirts(MachineInstr* MI) const {
+ return MI2VirtMap.equal_range(MI);
+ }
+
+ /// RemoveMachineInstrFromMaps - MI is being erased, remove it from the
+ /// the folded instruction map and spill point map.
+ void RemoveMachineInstrFromMaps(MachineInstr *MI);
+
+ /// FindUnusedRegisters - Gather a list of allocatable registers that
+ /// have not been allocated to any virtual register.
+ bool FindUnusedRegisters(LiveIntervals* LIs);
+
+ /// HasUnusedRegisters - Return true if there are any allocatable registers
+ /// that have not been allocated to any virtual register.
+ bool HasUnusedRegisters() const {
+ return !UnusedRegs.none();
+ }
+
+ /// setRegisterUsed - Remember the physical register is now used.
+ void setRegisterUsed(unsigned Reg) {
+ UnusedRegs.reset(Reg);
+ }
+
+ /// isRegisterUnused - Return true if the physical register has not been
+ /// used.
+ bool isRegisterUnused(unsigned Reg) const {
+ return UnusedRegs[Reg];
+ }
+
+ /// getFirstUnusedRegister - Return the first physical register that has not
+ /// been used.
+ unsigned getFirstUnusedRegister(const TargetRegisterClass *RC) {
+ int Reg = UnusedRegs.find_first();
+ while (Reg != -1) {
+ if (allocatableRCRegs[RC][Reg])
+ return (unsigned)Reg;
+ Reg = UnusedRegs.find_next(Reg);
+ }
+ return 0;
+ }
+
+ void print(raw_ostream &OS, const Module* M = 0) const;
+ void dump() const;
+ };
+
+ inline raw_ostream &operator<<(raw_ostream &OS, const VirtRegMap &VRM) {
+ VRM.print(OS);
+ return OS;
+ }
} // End llvm namespace
#endif