1 //===-- llvm/CodeGen/VirtRegMap.h - Virtual Register Map -*- C++ -*--------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by the LLVM research group and is distributed under
6 // the University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements a virtual register map. This maps virtual
11 // registers to physical registers and virtual registers to stack
12 // slots. It is created and updated by a register allocator and then
13 // used by a machine code rewriter that adds spill code and rewrites
14 // virtual into physical register references.
16 //===----------------------------------------------------------------------===//
18 #ifndef LLVM_CODEGEN_VIRTREGMAP_H
19 #define LLVM_CODEGEN_VIRTREGMAP_H
21 #include "llvm/CodeGen/MachineFunction.h"
22 #include "llvm/CodeGen/SSARegMap.h"
23 #include "Support/DenseMap.h"
30 typedef DenseMap<unsigned, VirtReg2IndexFunctor> Virt2PhysMap;
31 typedef DenseMap<int, VirtReg2IndexFunctor> Virt2StackSlotMap;
36 Virt2StackSlotMap v2ssMap_;
39 VirtRegMap(const VirtRegMap& rhs);
40 const VirtRegMap& operator=(const VirtRegMap& rhs);
44 NO_STACK_SLOT = INT_MAX
48 VirtRegMap(MachineFunction& mf)
51 v2ssMap_(NO_STACK_SLOT) {
52 v2pMap_.grow(mf.getSSARegMap()->getLastVirtReg());
53 v2ssMap_.grow(mf.getSSARegMap()->getLastVirtReg());
56 bool hasPhys(unsigned virtReg) const {
57 return getPhys(virtReg) != NO_PHYS_REG;
60 unsigned getPhys(unsigned virtReg) const {
61 assert(MRegisterInfo::isVirtualRegister(virtReg));
62 return v2pMap_[virtReg];
65 void assignVirt2Phys(unsigned virtReg, unsigned physReg) {
66 assert(MRegisterInfo::isVirtualRegister(virtReg) &&
67 MRegisterInfo::isPhysicalRegister(physReg));
68 assert(v2pMap_[virtReg] == NO_PHYS_REG &&
69 "attempt to assign physical register to already mapped "
71 v2pMap_[virtReg] = physReg;
74 void clearVirtReg(unsigned virtReg) {
75 assert(MRegisterInfo::isVirtualRegister(virtReg));
76 assert(v2pMap_[virtReg] != NO_PHYS_REG &&
77 "attempt to clear a not assigned virtual register");
78 v2pMap_[virtReg] = NO_PHYS_REG;
81 bool hasStackSlot(unsigned virtReg) const {
82 return getStackSlot(virtReg) != NO_STACK_SLOT;
85 int getStackSlot(unsigned virtReg) const {
86 assert(MRegisterInfo::isVirtualRegister(virtReg));
87 return v2ssMap_[virtReg];
90 int assignVirt2StackSlot(unsigned virtReg);
92 friend std::ostream& operator<<(std::ostream& os, const VirtRegMap& li);
95 std::ostream& operator<<(std::ostream& os, const VirtRegMap& li);
97 void eliminateVirtRegs(MachineFunction& mf, const VirtRegMap& vrm);
99 } // End llvm namespace