llvm-6502/lib/CodeGen/PhysRegTracker.h

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//===-- llvm/CodeGen/PhysRegTracker.h - Physical Register Tracker -*- 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 physical register tracker. The tracker
// tracks physical register usage through addRegUse and
// delRegUse. isRegAvail checks if a physical register is available or
// not taking into consideration register aliases.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_PHYSREGTRACKER_H
#define LLVM_CODEGEN_PHYSREGTRACKER_H
#include "llvm/Target/MRegisterInfo.h"
namespace llvm {
class PhysRegTracker {
const MRegisterInfo* mri_;
std::vector<unsigned> regUse_;
public:
PhysRegTracker(const MRegisterInfo& mri)
: mri_(&mri),
regUse_(mri_->getNumRegs(), 0) {
}
PhysRegTracker(const PhysRegTracker& rhs)
: mri_(rhs.mri_),
regUse_(rhs.regUse_) {
}
const PhysRegTracker& operator=(const PhysRegTracker& rhs) {
mri_ = rhs.mri_;
regUse_ = rhs.regUse_;
return *this;
}
void addRegUse(unsigned physReg) {
assert(MRegisterInfo::isPhysicalRegister(physReg) &&
"should be physical register!");
++regUse_[physReg];
for (const unsigned* as = mri_->getAliasSet(physReg); *as; ++as)
++regUse_[*as];
}
void delRegUse(unsigned physReg) {
assert(MRegisterInfo::isPhysicalRegister(physReg) &&
"should be physical register!");
assert(regUse_[physReg] != 0);
--regUse_[physReg];
for (const unsigned* as = mri_->getAliasSet(physReg); *as; ++as) {
assert(regUse_[*as] != 0);
--regUse_[*as];
}
}
bool isRegAvail(unsigned physReg) const {
assert(MRegisterInfo::isPhysicalRegister(physReg) &&
"should be physical register!");
return regUse_[physReg] == 0;
}
};
} // End llvm namespace
#endif