aboutsummaryrefslogtreecommitdiffstats
path: root/lib/CodeGen/PhysRegTracker.h
blob: 2717e337687a81bbd9eb4ede75b60bbddcc44219 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
//===-- 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:
        explicit 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