Simple-Compiler/LiveVariableAnalysis.cpp at main · Gemego/Simple-Compiler · GitHub

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
74
75
#include "LiveVariableAnalysis.h"
#include "MachineCode.h"
#include <algorithm>

void LiveVariableAnalysis::pass(MachineUnit *unit)
{
    for (auto &func : unit->getFuncs())
    {
        computeUsePos(func);
        computeDefUse(func);
        iterate(func);
    }
}

void LiveVariableAnalysis::pass(MachineFunction *func)
{
    computeUsePos(func);
    computeDefUse(func);
    iterate(func);
}

void LiveVariableAnalysis::computeDefUse(MachineFunction *func)
{
    for (auto &block : func->getBlocks())
    {
        for (auto inst = block->getInsts().begin(); inst != block->getInsts().end(); inst++)
        {
            auto user = (*inst)->getUse();
            std::set<MachineOperand *> temp(user.begin(), user.end());
            set_difference(temp.begin(), temp.end(),
                           def[block].begin(), def[block].end(), inserter(use[block], use[block].end()));
            auto defs = (*inst)->getDef();
            for (auto &d : defs)
                def[block].insert(all_uses[*d].begin(), all_uses[*d].end());
        }
    }
}

void LiveVariableAnalysis::iterate(MachineFunction *func)
{
    for (auto &block : func->getBlocks())
        block->getLiveIn().clear();
    bool change;
    change = true;
    while (change)
    {
        change = false;
        for (auto &block : func->getBlocks())
        {
            block->getLiveOut().clear();
            auto old = block->getLiveIn();
            for (auto &succ : block->getSuccs())
                block->getLiveOut().insert(succ->getLiveIn().begin(), succ->getLiveIn().end());
            block->getLiveIn() = use[block];
            std::vector<MachineOperand *> temp;
            set_difference(block->getLiveOut().begin(), block->getLiveOut().end(),
                           def[block].begin(), def[block].end(), inserter(block->getLiveIn(), block->getLiveIn().end()));
            if (old != block->getLiveIn())
                change = true;
        }
    }
}

void LiveVariableAnalysis::computeUsePos(MachineFunction *func)
{
    for (auto &block : func->getBlocks())
    {
        for (auto &inst : block->getInsts())
        {
            auto uses = inst->getUse();
            for (auto &use : uses)
                all_uses[*use].insert(use);
        }
    }
}