forked from OSchip/llvm-project
230 lines
8.5 KiB
C++
230 lines
8.5 KiB
C++
//===-- llvm/CodeGen/VirtRegMap.h - Virtual Register Map -*- C++ -*--------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file was developed by the LLVM research group and is distributed under
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// the University of Illinois Open Source License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements a virtual register map. This maps virtual registers to
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// physical registers and virtual registers to stack slots. It is created and
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// updated by a register allocator and then used by a machine code rewriter that
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// adds spill code and rewrites virtual into physical register references.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_CODEGEN_VIRTREGMAP_H
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#define LLVM_CODEGEN_VIRTREGMAP_H
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#include "llvm/Target/MRegisterInfo.h"
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#include "llvm/ADT/BitVector.h"
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#include "llvm/ADT/IndexedMap.h"
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#include "llvm/Support/Streams.h"
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#include <map>
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namespace llvm {
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class MachineInstr;
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class MachineFunction;
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class TargetInstrInfo;
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class VirtRegMap {
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public:
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enum {
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NO_PHYS_REG = 0,
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NO_STACK_SLOT = (1L << 30)-1,
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MAX_STACK_SLOT = (1L << 18)-1
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};
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enum ModRef { isRef = 1, isMod = 2, isModRef = 3 };
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typedef std::multimap<MachineInstr*,
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std::pair<unsigned, ModRef> > MI2VirtMapTy;
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private:
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const TargetInstrInfo &TII;
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MachineFunction &MF;
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/// Virt2PhysMap - This is a virtual to physical register
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/// mapping. Each virtual register is required to have an entry in
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/// it; even spilled virtual registers (the register mapped to a
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/// spilled register is the temporary used to load it from the
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/// stack).
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IndexedMap<unsigned, VirtReg2IndexFunctor> Virt2PhysMap;
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/// Virt2StackSlotMap - This is virtual register to stack slot
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/// mapping. Each spilled virtual register has an entry in it
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/// which corresponds to the stack slot this register is spilled
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/// at.
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IndexedMap<int, VirtReg2IndexFunctor> Virt2StackSlotMap;
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IndexedMap<int, VirtReg2IndexFunctor> Virt2ReMatIdMap;
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/// MI2VirtMap - This is MachineInstr to virtual register
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/// mapping. In the case of memory spill code being folded into
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/// instructions, we need to know which virtual register was
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/// read/written by this instruction.
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MI2VirtMapTy MI2VirtMap;
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/// ReMatMap - This is virtual register to re-materialized instruction
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/// mapping. Each virtual register whose definition is going to be
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/// re-materialized has an entry in it.
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IndexedMap<MachineInstr*, VirtReg2IndexFunctor> ReMatMap;
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/// ReMatId - Instead of assigning a stack slot to a to be rematerialized
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/// virtual register, an unique id is being assigned. This keeps track of
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/// the highest id used so far. Note, this starts at (1<<18) to avoid
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/// conflicts with stack slot numbers.
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int ReMatId;
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VirtRegMap(const VirtRegMap&); // DO NOT IMPLEMENT
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void operator=(const VirtRegMap&); // DO NOT IMPLEMENT
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public:
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explicit VirtRegMap(MachineFunction &mf);
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void grow();
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/// @brief returns true if the specified virtual register is
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/// mapped to a physical register
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bool hasPhys(unsigned virtReg) const {
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return getPhys(virtReg) != NO_PHYS_REG;
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}
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/// @brief returns the physical register mapped to the specified
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/// virtual register
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unsigned getPhys(unsigned virtReg) const {
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assert(MRegisterInfo::isVirtualRegister(virtReg));
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return Virt2PhysMap[virtReg];
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}
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/// @brief creates a mapping for the specified virtual register to
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/// the specified physical register
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void assignVirt2Phys(unsigned virtReg, unsigned physReg) {
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assert(MRegisterInfo::isVirtualRegister(virtReg) &&
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MRegisterInfo::isPhysicalRegister(physReg));
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assert(Virt2PhysMap[virtReg] == NO_PHYS_REG &&
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"attempt to assign physical register to already mapped "
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"virtual register");
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Virt2PhysMap[virtReg] = physReg;
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}
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/// @brief clears the specified virtual register's, physical
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/// register mapping
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void clearVirt(unsigned virtReg) {
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assert(MRegisterInfo::isVirtualRegister(virtReg));
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assert(Virt2PhysMap[virtReg] != NO_PHYS_REG &&
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"attempt to clear a not assigned virtual register");
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Virt2PhysMap[virtReg] = NO_PHYS_REG;
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}
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/// @brief clears all virtual to physical register mappings
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void clearAllVirt() {
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Virt2PhysMap.clear();
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grow();
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}
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/// @brief returns true is the specified virtual register is not
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/// mapped to a stack slot or rematerialized.
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bool isAssignedReg(unsigned virtReg) const {
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return getStackSlot(virtReg) == NO_STACK_SLOT &&
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getReMatId(virtReg) == NO_STACK_SLOT;
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}
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/// @brief returns the stack slot mapped to the specified virtual
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/// register
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int getStackSlot(unsigned virtReg) const {
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assert(MRegisterInfo::isVirtualRegister(virtReg));
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return Virt2StackSlotMap[virtReg];
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}
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/// @brief returns the rematerialization id mapped to the specified virtual
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/// register
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int getReMatId(unsigned virtReg) const {
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assert(MRegisterInfo::isVirtualRegister(virtReg));
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return Virt2ReMatIdMap[virtReg];
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}
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/// @brief create a mapping for the specifed virtual register to
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/// the next available stack slot
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int assignVirt2StackSlot(unsigned virtReg);
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/// @brief create a mapping for the specified virtual register to
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/// the specified stack slot
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void assignVirt2StackSlot(unsigned virtReg, int frameIndex);
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/// @brief assign an unique re-materialization id to the specified
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/// virtual register.
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int assignVirtReMatId(unsigned virtReg);
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/// @brief assign an unique re-materialization id to the specified
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/// virtual register.
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void assignVirtReMatId(unsigned virtReg, int id);
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/// @brief returns true if the specified virtual register is being
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/// re-materialized.
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bool isReMaterialized(unsigned virtReg) const {
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return ReMatMap[virtReg] != NULL;
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}
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/// @brief returns the original machine instruction being re-issued
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/// to re-materialize the specified virtual register.
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MachineInstr *getReMaterializedMI(unsigned virtReg) const {
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return ReMatMap[virtReg];
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}
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/// @brief records the specified virtual register will be
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/// re-materialized and the original instruction which will be re-issed
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/// for this purpose. If parameter all is true, then all uses of the
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/// registers are rematerialized and it's safe to delete the definition.
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void setVirtIsReMaterialized(unsigned virtReg, MachineInstr *def) {
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ReMatMap[virtReg] = def;
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}
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/// @brief Updates information about the specified virtual register's value
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/// folded into newMI machine instruction. The OpNum argument indicates the
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/// operand number of OldMI that is folded.
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void virtFolded(unsigned VirtReg, MachineInstr *OldMI, unsigned OpNum,
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MachineInstr *NewMI);
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/// @brief Updates information about the specified virtual register's value
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/// folded into the specified machine instruction.
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void virtFolded(unsigned VirtReg, MachineInstr *MI, ModRef MRInfo);
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/// @brief returns the virtual registers' values folded in memory
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/// operands of this instruction
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std::pair<MI2VirtMapTy::const_iterator, MI2VirtMapTy::const_iterator>
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getFoldedVirts(MachineInstr* MI) const {
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return MI2VirtMap.equal_range(MI);
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}
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/// RemoveFromFoldedVirtMap - If the specified machine instruction is in
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/// the folded instruction map, remove its entry from the map.
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void RemoveFromFoldedVirtMap(MachineInstr *MI) {
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MI2VirtMap.erase(MI);
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}
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void print(std::ostream &OS) const;
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void print(std::ostream *OS) const { if (OS) print(*OS); }
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void dump() const;
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};
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inline std::ostream *operator<<(std::ostream *OS, const VirtRegMap &VRM) {
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VRM.print(OS);
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return OS;
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}
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inline std::ostream &operator<<(std::ostream &OS, const VirtRegMap &VRM) {
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VRM.print(OS);
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return OS;
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}
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/// Spiller interface: Implementations of this interface assign spilled
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/// virtual registers to stack slots, rewriting the code.
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struct Spiller {
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virtual ~Spiller();
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virtual bool runOnMachineFunction(MachineFunction &MF,
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VirtRegMap &VRM) = 0;
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};
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/// createSpiller - Create an return a spiller object, as specified on the
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/// command line.
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Spiller* createSpiller();
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} // End llvm namespace
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#endif
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