//
//===----------------------------------------------------------------------===//
//
-// 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/Target/MRegisterInfo.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/IndexedMap.h"
+#include "llvm/Support/Streams.h"
+#include <map>
namespace llvm {
+ class MachineInstr;
+ class MachineFunction;
+ class TargetInstrInfo;
- 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:
+ 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:
+ const TargetInstrInfo &TII;
+
+ MachineFunction &MF;
+ /// 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;
+
+ /// Virt2StackSlotMap - 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;
+
+ /// 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<unsigned> > SpillPt2VirtMap;
+
+ /// 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;
+
+ VirtRegMap(const VirtRegMap&); // DO NOT IMPLEMENT
+ void operator=(const VirtRegMap&); // DO NOT IMPLEMENT
+
+ public:
+ explicit VirtRegMap(MachineFunction &mf);
+
+ 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(MRegisterInfo::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(MRegisterInfo::isVirtualRegister(virtReg) &&
+ MRegisterInfo::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(MRegisterInfo::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 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 is 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(MRegisterInfo::isVirtualRegister(virtReg));
+ return Virt2StackSlotMap[virtReg];
+ }
+
+ /// @brief returns the rematerialization id mapped to the specified virtual
+ /// register
+ int getReMatId(unsigned virtReg) const {
+ assert(MRegisterInfo::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 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<unsigned> &getSpillPtSpills(MachineInstr *Pt) {
+ return SpillPt2VirtMap[Pt];
+ }
+
+ /// @brief records the specified MachineInstr as a spill point for virtReg.
+ void addSpillPoint(unsigned virtReg, MachineInstr *Pt) {
+ if (SpillPt2VirtMap.find(Pt) != SpillPt2VirtMap.end())
+ SpillPt2VirtMap[Pt].push_back(virtReg);
+ else {
+ std::vector<unsigned> Virts;
+ Virts.push_back(virtReg);
+ SpillPt2VirtMap.insert(std::make_pair(Pt, Virts));
+ }
+ }
+
+ void transferSpillPts(MachineInstr *Old, MachineInstr *New) {
+ std::map<MachineInstr*,std::vector<unsigned> >::iterator I =
+ SpillPt2VirtMap.find(Old);
+ if (I == SpillPt2VirtMap.end())
+ return;
+ while (!I->second.empty()) {
+ unsigned virtReg = I->second.back();
+ I->second.pop_back();
+ addSpillPoint(virtReg, New);
+ }
+ SpillPt2VirtMap.erase(I);
+ }
+
+ /// @brief Updates information about the specified virtual register's value
+ /// folded into newMI machine instruction. The OpNum argument indicates the
+ /// operand number of OldMI that is folded.
+ void virtFolded(unsigned VirtReg, MachineInstr *OldMI, unsigned OpNum,
+ MachineInstr *NewMI);
+
+ /// @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) {
+ MI2VirtMap.erase(MI);
+ SpillPt2VirtMap.erase(MI);
+ }
+
+ void print(std::ostream &OS) const;
+ void print(std::ostream *OS) const { if (OS) print(*OS); }
+ void dump() const;
+ };
+
+ inline std::ostream *operator<<(std::ostream *OS, const VirtRegMap &VRM) {
+ VRM.print(OS);
+ return OS;
+ }
+ inline std::ostream &operator<<(std::ostream &OS, const VirtRegMap &VRM) {
+ VRM.print(OS);
+ return OS;
+ }
+
+ /// Spiller interface: Implementations of this interface assign spilled
+ /// virtual registers to stack slots, rewriting the code.
+ struct Spiller {
+ virtual ~Spiller();
+ virtual bool runOnMachineFunction(MachineFunction &MF,
+ VirtRegMap &VRM) = 0;
+ };
+
+ /// createSpiller - Create an return a spiller object, as specified on the
+ /// command line.
+ Spiller* createSpiller();
} // End llvm namespace
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