llvm-project/llvm/lib/CodeGen/VirtRegMap.h

106 lines
3.5 KiB
C++

//===-- llvm/CodeGen/VirtRegMap.h - Virtual Register Map -*- C++ -*--------===//
//
// 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 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>
namespace llvm {
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);
};
std::ostream& operator<<(std::ostream& os, const VirtRegMap& li);
void eliminateVirtRegs(MachineFunction& mf, const VirtRegMap& vrm);
} // End llvm namespace
#endif