SAPFOR/Sapfor/_src/Transformations/loops_combiner.cpp

#include "loops_combiner.h"

#include "../LoopAnalyzer/loop_analyzer.h"
#include "../ExpressionTransform/expr_transform.h"
#include "../Utils/errors.h"
#include "../Utils/SgUtils.h"
#include <string>
#include <vector>
#include <queue>

using std::string;
using std::vector;
using std::map;
using std::set;
using std::pair;
using std::make_pair;
using std::queue;
using std::wstring;

static int gcd(int a, int b)
{
    while (a != b)
    {
        if (a > b)
            a = a - b;
        else
            b = b - a;
    }
    
    return a;
}

static SgSymbol* getLoopSymbol(const LoopGraph* loop)
{
    if (!loop || !loop->isFor)
        return NULL;

    SgForStmt* stmt = (SgForStmt*)loop->loop->GetOriginal();
    return stmt->doName();
}

static void fillIterationVariables(const LoopGraph* loop, set<SgSymbol*>& vars, int dimensions = -1)
{
    if (dimensions == -1)
    {
        auto s = getLoopSymbol(loop);
        if (s)
            vars.insert(s);
        for (LoopGraph* child : loop->children)
            fillIterationVariables(child, vars);
    }
    else
    {
        for (int i = 0; i < dimensions; ++i)
        {
            auto s = getLoopSymbol(loop);
            if (s)
                vars.insert(s);

            if (i != dimensions - 1)
                loop = loop->children[0];
        }
    }
}

static void eraseSymbolFromSet(set<SgSymbol*>& symbols, SgSymbol* symbol)
{
    SgSymbol* toDelete = NULL;
    for (SgSymbol* elem : symbols)
    {
        if (isEqSymbols(elem, symbol))
        {
            toDelete = elem;
            break;
        }
    }

    if (toDelete)
        symbols.erase(toDelete);
}

static bool isSymbolInSet(const set<SgSymbol*>& symbols, SgSymbol* symbol)
{
    for (SgSymbol* elem : symbols)
        if (isEqSymbols(elem, symbol))
            return true;
    
    return false;
}

static void getIntersection(const set<SgSymbol*>& firstSet, const set<SgSymbol*>& secondSet, set<SgSymbol*>& intersection)
{
    for (SgSymbol* var1 : firstSet)
    {
        for (SgSymbol* var2 : secondSet)
        {
            if (isEqSymbols(var1, var2))
            {
                intersection.insert(var1);
                break;
            }
        }
    }
}

static bool hasGotoToStatement(SgStatement* stmt)
{
    if (!stmt->hasLabel())
        return false;

    SgStatement* parent;
    parent = getFuncStat(stmt);

    for (SgStatement* current = parent->lexNext(); current != parent->lastNodeOfStmt(); current = current->lexNext())
    {
        if (current->variant() == GOTO_NODE)
        {
            SgLabel* label = ((SgGotoStmt*)current)->branchLabel();
            if (label->id() == stmt->label()->id())
                return true;
        }
    }

    return false;
}

// Проверить на равенство expr1 и expr2
static bool isEqExpressions(SgExpression* exp1, SgExpression* exp2)
{
    string str1, str2;
    
    if (exp1 != NULL)
    {
        exp1 = CalculateInteger(exp1->copyPtr());
        str1 = exp1->unparse();
    }

    if (exp2 != NULL)
    {
        exp2 = CalculateInteger(exp2->copyPtr());
        str2 = exp2->unparse();
    }

    return str1 == str2;
}

// Проверить, что expr1 и expr2 противоположны по значению
static bool isOppositeExpressions(SgExpression* exp1, SgExpression* exp2)
{
    if (exp1 == NULL || exp2 == NULL)
        return false;

    exp1 = CalculateInteger(exp1->copyPtr());
    exp2 = CalculateInteger(exp2->copyPtr());

    if (exp1->variant() == MINUS_OP)
        return isEqExpressions(exp1->lhs(), exp2);
    if (exp2->variant() == MINUS_OP)
        return isEqExpressions(exp1, exp2->lhs());

    if (exp1->variant() == INT_VAL && exp2->variant() == INT_VAL)
        return exp1->valueInteger() == -1 * exp2->valueInteger();

    return false;
}

static bool ifLoopCanBeReversed(LoopGraph* loop, const map<LoopGraph*, depGraph*>& depInfoForLoopGraph)
{
    const set<string> privVars;
    auto dependency = depInfoForLoopGraph.find(loop);
    if (dependency == depInfoForLoopGraph.end())
        return false;

    vector<depNode*> nodes = (dependency->second)->getNodes();
    for (depNode* node : nodes)
    {
        int type = node->typedep;

        const ddnature nature = (ddnature)node->kinddep;

        if (type == ARRAYDEP && (nature == ddoutput || nature == ddreduce))
            continue;

        if (type == PRIVATEDEP)
            continue;
        
        return false;
    }

    return true;
}

static void reverseLoop(LoopGraph* loop, int dimensions)
{
    if (loop == NULL)
        return;

    for (int i = 0; i < dimensions; ++i)
    {
        if (loop->calculatedCountOfIters != 0) {
            std::swap(loop->startVal, loop->endVal);
            loop->stepVal *= -1;
        }

        SgForStmt* loopStmt = isSgForStmt(loop->loop->GetOriginal());
        checkNull(loopStmt, convertFileName(__FILE__).c_str(), __LINE__);

        SgExpression& start = loopStmt->start()->copy();
        loopStmt->setStart(loopStmt->end()->copy());
        loopStmt->setEnd(start);

        SgExpression* tmpEx = loopStmt->step();
        if (tmpEx == NULL)
            tmpEx = new SgValueExp(1);

        if (tmpEx->variant() == MINUS_OP)
        {
            SgExpression* lhs = tmpEx->lhs();   
            loopStmt->setStep(*lhs);
        }
        else
            loopStmt->setStep(*(new SgExpression(MINUS_OP, tmpEx, NULL)));
    
        Expression* startExpr = loopStmt->start() ? new Expression(loopStmt->start()) : NULL;
        Expression* endExpr   = loopStmt->end()   ? new Expression(loopStmt->end())   : NULL;
        Expression* stepExpr  = loopStmt->step()  ? new Expression(loopStmt->step())  : NULL;
        loop->startEndStepVals = std::make_tuple(startExpr, endExpr, stepExpr);

        if (i != dimensions - 1)
            loop = loop->children[0];
    }
}

static bool isSimpleExpression(SgExpression* expr)
{
    // simple expression:
    // CONST_REF / INT_VAL / VAR_REF / MINUS_OP VAR_REF / 
    // (VAR_REF (ADD_OP / SUBT_OP) INT_VAL) / (INT_VAL (ADD_OP / SUBT_OP) VAR_REF)

    SgExpression* lhs = expr->lhs(), *rhs = expr->rhs();
    SgConstantSymb* constExpr = NULL;

    switch (expr->variant()) {
    case CONST_REF:
        constExpr = isSgConstantSymb(expr->symbol());
        if (constExpr && constExpr->constantValue()->isInteger())
            return true;
        else
            return false;

    case VAR_REF:
    case INT_VAL:
        return true;

    case MINUS_OP:
        if (expr->lhs()->variant() != VAR_REF && !expr->lhs()->isInteger())
            return false;

        return true;

    case ADD_OP:
    case SUBT_OP:
        if (!lhs || !rhs)
            printInternalError(convertFileName(__FILE__).c_str(), __LINE__);

        if (lhs->variant() != VAR_REF && !lhs->isInteger())
            return false;

        if (rhs->variant() != VAR_REF && !rhs->isInteger())
            return false;

        if (!((lhs->variant() == VAR_REF) ^ (rhs->variant() == VAR_REF)))  // only one variable
            return false;

        return true;

    default:
        return false;
    }
}

static bool hasEqualVars(SgExpression* firstExpr, SgExpression* secondExpr)
{
    set<string> firstVars;
    getVariables(firstExpr, firstVars, set<int> { VAR_REF });

    set<string> secondVars;
    getVariables(secondExpr, secondVars, set<int> { VAR_REF });

    if (firstVars.size() != secondVars.size())
        return false;

    for (const string var : firstVars)
        if (secondVars.find(var) == secondVars.end())
            return false;

    return true;
}

// simple expression: var + varAdd
// varMinus -- is a minus before var
static void getSimpleExprVarParams(SgExpression* expr, bool* varMinus, int* varAdd)
{
    if (expr->variant() == VAR_REF)
    {
        *varMinus = false;
        *varAdd = 0;
    }
    else if (expr->variant() == MINUS_OP && expr->lhs()->variant() == VAR_REF)
    {
        *varMinus = true;
        *varAdd = 0;
    }
    else if (expr->variant() == ADD_OP)
    {
        *varMinus = false;
        if (expr->lhs()->isInteger())
            *varAdd = expr->lhs()->valueInteger();
        else
            *varAdd = expr->rhs()->valueInteger();
    }
    else if (expr->variant() == SUBT_OP)
    {
        if (expr->lhs()->isInteger())
        {
            *varMinus = true;
            *varAdd = expr->lhs()->valueInteger();
        }
        else
        {
            *varMinus = false;
            *varAdd = (-1) * expr->rhs()->valueInteger();
        }
    }
    else
        printInternalError(convertFileName(__FILE__).c_str(), __LINE__);
}

// returns 1 if equal, 0 if first < second, 2 if first > second
// -1 if impossible to compare
static int compareSimpleExpressions(SgExpression* firstExpr, SgExpression* secondExpr)
{
    if (!hasEqualVars(firstExpr, secondExpr))
        return -1;

    SgConstantSymb* constExpr1 = isSgConstantSymb(firstExpr->symbol());
    if (constExpr1)
        firstExpr = constExpr1->constantValue();

    SgConstantSymb* constExpr2 = isSgConstantSymb(secondExpr->symbol());
    if (constExpr2)
        secondExpr = constExpr2->constantValue();

    if (firstExpr->isInteger() && secondExpr->isInteger())
    {
        int firstVal = firstExpr->valueInteger();
        int secondVal = secondExpr->valueInteger();

        if (firstVal == secondVal)
            return 1;
        else if (firstVal < secondVal)
            return 0;
        else
            return 2;
    }

    bool minusVarFirst = false, minusVarSecond = false;
    int addVarFirst = 0, addVarSecond = 0;

    getSimpleExprVarParams(firstExpr, &minusVarFirst, &addVarFirst);
    getSimpleExprVarParams(secondExpr, &minusVarSecond, &addVarSecond);

    if (minusVarFirst != minusVarSecond)  // vars have different sign
        return -1;

    if (addVarFirst == addVarSecond)
        return 1;
    else if (addVarFirst < addVarSecond)
        return 0;
    else
        return 2;
}

static bool canBeCombinedWithDiffBounds(const LoopGraph* firstLoop, const LoopGraph* loop)
{
    // TODO: удалить после добавления анализа зависимостей по массивам:
    return false;
    //

    if (firstLoop->hasLimitsToCombine() || loop->hasLimitsToCombine())
        return false;

    SgForStmt* firstLoopStmt = isSgForStmt(firstLoop->loop->GetOriginal());
    checkNull(firstLoopStmt, convertFileName(__FILE__).c_str(), __LINE__);

    SgForStmt* loopStmt = isSgForStmt(loop->loop->GetOriginal());
    checkNull(loopStmt, convertFileName(__FILE__).c_str(), __LINE__);

    if (hasGotoToStatement(firstLoopStmt) || hasGotoToStatement(loopStmt))
        return false;

    if (!isSimpleExpression(firstLoopStmt->start()) || !isSimpleExpression(firstLoopStmt->end()))
        return false;

    if (!isSimpleExpression(loopStmt->start()) || !isSimpleExpression(loopStmt->end()))
        return false;

    if (firstLoop->calculatedCountOfIters != 0 && loop->calculatedCountOfIters != 0)
    {
        // intersection of ranges is not empty:
        if (firstLoop->stepVal > 0)
        {
            if (firstLoop->startVal > loop->endVal || firstLoop->endVal < loop->startVal)
                return false;
        }
        else
        {
            if (firstLoop->startVal < loop->endVal || firstLoop->endVal > loop->startVal)
                return false;
        }

        if (firstLoop->stepVal * loop->stepVal < 0)  // steps have different sign
            return false;

        return true;
    }

    SgExpression* step1 = firstLoopStmt->step();
    SgExpression* step2 = loopStmt->step();
    int step1Val = 1, step2Val = 1;

    if (step1 != NULL)
    {
        if (step1->isInteger())
            step1Val = step1->valueInteger();
        else
            return false;
    }
    if (step2 != NULL)
    {
        if (step2->isInteger())
            step2Val = step2->valueInteger();
        else
            return false;
    }

    if (step1Val * step2Val < 0)  // steps have different sign
        return false;

    int compStart = compareSimpleExpressions(firstLoopStmt->start(), loopStmt->start());
    int compEnd = compareSimpleExpressions(firstLoopStmt->end(), loopStmt->end());

    if (compStart == -1 || compEnd == -1)  // impossible to compare
        return false;

    return true;
}

static int getDeepestDimToReverse(LoopGraph* firstLoop, LoopGraph* loop, int perfectLoop, 
                                 LoopGraph** toReverse, const map<LoopGraph*, depGraph*>& depInfoForLoopGraph)
{
    LoopGraph* curFirstLoop = firstLoop;
    LoopGraph* curLoop = loop;
    int i = 0;

    bool canBeReversed1 = ifLoopCanBeReversed(firstLoop, depInfoForLoopGraph);
    bool canBeReversed2 = ifLoopCanBeReversed(loop, depInfoForLoopGraph);
    if (!canBeReversed1 && !canBeReversed2)
        return 0;

    for (i = 0; i < perfectLoop; ++i)
    {
        SgForStmt* firstLoopStmt = isSgForStmt(curFirstLoop->loop->GetOriginal());
        checkNull(firstLoopStmt, convertFileName(__FILE__).c_str(), __LINE__);

        SgForStmt* loopStmt = isSgForStmt(curLoop->loop->GetOriginal());
        checkNull(loopStmt, convertFileName(__FILE__).c_str(), __LINE__);

        if (curLoop->hasLimitsToCombine() || hasGotoToStatement(loopStmt))
            break;

        if (curFirstLoop->calculatedCountOfIters != 0 && curLoop->calculatedCountOfIters != 0) {
            if (curFirstLoop->startVal != curLoop->endVal)
                break;
            if (curFirstLoop->endVal != curLoop->startVal)
                break;
            if (curFirstLoop->stepVal != -1 * curLoop->stepVal)
                break;
        }
        else {
            if (!isEqExpressions(std::get<0>(curFirstLoop->startEndStepVals), std::get<1>(curLoop->startEndStepVals)))
                break;

            if (!isEqExpressions(std::get<1>(curFirstLoop->startEndStepVals), std::get<0>(curLoop->startEndStepVals)))
                break;

            SgExpression* step1 = std::get<2>(curFirstLoop->startEndStepVals);
            SgExpression* step2 = std::get<2>(curLoop->startEndStepVals);
            SgValueExp defaultStep(1);
            if (step1 == NULL)
                step1 = &defaultStep;
            if (step2 == NULL)
                step2 = &defaultStep;

            if (!isOppositeExpressions(step1, step2))
                break;
        }

        if (i != perfectLoop - 1)
        {
            if (curLoop->children.size() != 1)
                break;

            curFirstLoop = curFirstLoop->children[0];
            curLoop = curLoop->children[0];
        }
    }

    if (i > 0)
    {
        if (canBeReversed1)
            *toReverse = firstLoop;
        else
            *toReverse = loop;
    }

    return i;
}

/**
  *  Найти количество измерений, объединение по которым возможно.
  */
static int getDeepestDimForCombine(const LoopGraph* firstLoop, const LoopGraph* loop, int perfectLoop)
{
    const LoopGraph* curFirstLoop = firstLoop;
    const LoopGraph* curLoop = loop;
    int i = 0;

    for (i = 0; i < perfectLoop; ++i)
    {
        SgForStmt* firstLoopStmt = isSgForStmt(curFirstLoop->loop->GetOriginal());
        checkNull(firstLoopStmt, convertFileName(__FILE__).c_str(), __LINE__);

        SgForStmt* loopStmt = isSgForStmt(curLoop->loop->GetOriginal());
        checkNull(loopStmt, convertFileName(__FILE__).c_str(), __LINE__);

        if (curLoop->hasLimitsToCombine() || hasGotoToStatement(loopStmt))
            return i;

        if (curFirstLoop->calculatedCountOfIters != 0 && curLoop->calculatedCountOfIters != 0) {
            if (curFirstLoop->startVal != curLoop->startVal)
                return i;
            if (curFirstLoop->endVal != curLoop->endVal)
                return i;
            if (curFirstLoop->stepVal != curLoop->stepVal)
                return i;
        }
        else {
            // startVal:
            if (!isEqExpressions(std::get<0>(curFirstLoop->startEndStepVals), std::get<0>(curLoop->startEndStepVals)))
                return i;

            // endVal:
            if (!isEqExpressions(std::get<1>(curFirstLoop->startEndStepVals), std::get<1>(curLoop->startEndStepVals)))
                return i;

            SgExpression* step1 = std::get<2>(curFirstLoop->startEndStepVals);
            SgExpression* step2 = std::get<2>(curLoop->startEndStepVals);

            if (!isEqExpressions(step1, step2))
            {
                if ((step1 == NULL) ^ (step2 == NULL))
                {
                    SgValueExp defaultStep(1);
                    if (step1 == NULL)
                        step1 = &defaultStep;
                    else
                        step2 = &defaultStep;

                    if (!isEqExpressions(step1, step2))
                        return i;
                }
                else
                    return i;
            }
        }

        if (i != perfectLoop - 1)
        {
            curFirstLoop = curFirstLoop->children[0];
            curLoop = curLoop->children[0];
        }
    }

    return i;
}

static void compareIterationVars(const LoopGraph* firstLoop, const LoopGraph* loop, int dimensions, map<SgSymbol*, SgSymbol*>& symbols)
{
    for (int i = 0; i < dimensions; ++i)
    {
        SgForStmt* firstLoopStmt = isSgForStmt(firstLoop->loop->GetOriginal());
        checkNull(firstLoopStmt, convertFileName(__FILE__).c_str(), __LINE__);

        SgForStmt* loopStmt = isSgForStmt(loop->loop->GetOriginal());
        checkNull(loopStmt, convertFileName(__FILE__).c_str(), __LINE__);

        if (!isEqSymbols(firstLoopStmt->doName(), loopStmt->doName()))
            symbols.insert(make_pair(loopStmt->doName(), firstLoopStmt->doName()));

        if (i != dimensions - 1)
        {
            firstLoop = firstLoop->children[0];
            loop = loop->children[0];
        }
    }
}

static SgSymbol* copySymbolAndRename(SgSymbol* symbol)
{
    string baseName = symbol->identifier();

    size_t pos = baseName.rfind('_');
    string strNumber;
    int number;
    if (pos != string::npos)
    {
        for (size_t i = pos + 1; i < baseName.length(); ++i)
        {
            if (baseName[i] >= '0' && baseName[i] <= '9')
                strNumber.push_back(baseName[i]);
            else
            {
                strNumber.clear();
                break;
            }
        }
    }

    if (!strNumber.empty())
    {
        baseName.resize(baseName.length() - (strNumber.length() + 1));
        number = atoi(strNumber.c_str()) + 1;
    }
    else
        number = 1;

    int new_name_num = checkSymbNameAndCorrect(baseName + '_', number);
    string new_name = baseName + '_' + std::to_string(new_name_num);

    SgSymbol* new_sym = &symbol->copy();
    new_sym->changeName(new_name.c_str());

    return new_sym;
}

static void renameVariables(const map<SgSymbol*, SgSymbol*>& symbols, SgExpression* ex)
{
    if (ex)
    {
        if ((ex->variant() == VAR_REF || isArrayRef(ex)) && ex->symbol())
        {
            for (auto& pair : symbols)
            {
                if (isEqSymbols(pair.first, ex->symbol()))
                {
                    ex->setSymbol(pair.second);
                    break;
                }
            }
        }

        renameVariables(symbols, ex->lhs());
        renameVariables(symbols, ex->rhs());
    }
}

static void renameIterationVariables(LoopGraph* loop, const map<SgSymbol*, SgSymbol*>& symbols)
{
    if (loop)
    {
        string& loopName = loop->loopSymbol;
        for (auto& pair : symbols)
        {
            if (pair.first->identifier() == loopName)
            {
                loop->loopSymbol = (string)pair.second->identifier();
                break;
            }
        }

        for (LoopGraph* child : loop->children)
            renameIterationVariables(child, symbols);
    }
}

static void renameVariablesInLoop(LoopGraph* loop, const map<SgSymbol*, SgSymbol*>& symbols)
{
    renameIterationVariables(loop, symbols);

    for (SgStatement* st = loop->loop; st != loop->loop->lastNodeOfStmt(); st = st->lexNext())
    {
        if (st->variant() == FOR_NODE)
        {
            SgForStmt* for_st = (SgForStmt*)st;
            for (auto& pair : symbols)
                if (isEqSymbols(pair.first, for_st->symbol()))
                    for_st->setDoName(*pair.second);
        }

        for (int i = 0; i < 3; ++i)
            renameVariables(symbols, st->expr(i));
    }
}

static void renamePrivatesInMap(LoopGraph* loop, const map<SgSymbol*, SgSymbol*>& symbols, map<LoopGraph*, set<SgSymbol*>>& mapPrivates)
{
    auto privates = mapPrivates.find(loop);
    if (loop && privates != mapPrivates.end())
    {
        set<SgSymbol*> newList;
        for (auto& priv : privates->second)
        {
            bool found = false;
            for (auto& pair : symbols)
            {
                if (isEqSymbols(priv, pair.first))
                {
                    found = true;
                    newList.insert(pair.second);
                    break;
                }
            }

            if (!found)
                newList.insert(priv);
        }
        privates->second = newList;

        for (LoopGraph* child : loop->children)
            renamePrivatesInMap(child, symbols, mapPrivates);
    }
}

static void addIterationVarsToMap(LoopGraph* loop, map<LoopGraph*, set<SgSymbol*>>& mapPrivates)
{
    auto privates = mapPrivates.find(loop);
    if (loop && privates != mapPrivates.end())
    {
        set<SgSymbol*> symbols;
        fillIterationVariables(loop, symbols);
        for (SgSymbol* var : symbols)
            if (!isSymbolInSet(privates->second, var))
                privates->second.insert(var);

        for (LoopGraph* child : loop->children)
            addIterationVarsToMap(child, mapPrivates);
    }
}

static void fillMapPrivateVars(const vector<LoopGraph*>& loopGraphs, map<LoopGraph*, set<SgSymbol*>>& mapPrivates)
{
    if (loopGraphs.size() == 0)
        return;

    for (int i = 0; i < loopGraphs.size(); ++i)
    {
        LoopGraph* loop = loopGraphs[i];

        set<Symbol*> symbols;
        for (auto& data : getAttributes<SgStatement*, SgStatement*>(loop->loop, set<int>{ SPF_ANALYSIS_DIR }))
            fillPrivatesFromComment(new Statement(data), symbols);

        set<SgSymbol*> loopPrivates;
        for (Symbol* symbol : symbols)
            loopPrivates.insert(OriginalSymbol((SgSymbol*)symbol));

        mapPrivates.insert(make_pair(loop, loopPrivates));

        if (!loop->children.empty())
            fillMapPrivateVars(loop->children, mapPrivates);
    }
}

static SgForStmt* getInnerLoop(const LoopGraph* loop, int deep)
{
    int perfectLoop = loop->perfectLoop;
    const LoopGraph* curLoop = loop;
    SgForStmt* result = NULL;

    for (int i = 0; i < deep; ++i)
    {
        result = isSgForStmt(curLoop->loop->GetOriginal());
        checkNull(result, convertFileName(__FILE__).c_str(), __LINE__);

        if (i != perfectLoop - 1)
            curLoop = curLoop->children[0];
    }

    return result;
}

static void moveBody(SgStatement* from, SgStatement* to, const map<SgSymbol*, SgSymbol*>& symbols)
{
    for (auto st = from->lexNext(); st != from->lastNodeOfStmt(); st = st->lexNext())
        for (int i = 0; i < 3; ++i)
            renameVariables(symbols, st->expr(i));

    auto loopBody = from->extractStmtBody();
    to->lastExecutable()->insertStmtAfter(*loopBody, *to);
}

static SgExpression* createIterationCountExpr(const LoopGraph* loop)
{
    // loop: do i = a, b, c
    // iteration count expression after loop: (a + ((b - a + c) / c - 1) * c) => [a + 'cIters']

    SgForStmt* firstLoopStmt = isSgForStmt(loop->loop->GetOriginal());
    checkNull(firstLoopStmt, convertFileName(__FILE__).c_str(), __LINE__);

    SgExpression* a = firstLoopStmt->start();
    SgExpression* b = firstLoopStmt->end();
    SgExpression* c = firstLoopStmt->step();

    if (c == NULL)
        c = new SgValueExp(1);

    SgExpression* ex = &(*a + ((*b - *a + *c) / *c - *new SgValueExp(1)) * *c);
    return ex;
}

static void changeVarToExpr(SgExpression* expression, SgSymbol* var, SgExpression* changeExpr)
{
    if (expression == NULL || var == NULL)
        return;

    SgExpression* lhs = expression->lhs();
    SgExpression* rhs = expression->rhs();

    if (lhs && lhs->symbol() && isEqSymbols(lhs->symbol(), var))
        expression->setLhs(changeExpr);

    if (rhs && rhs->symbol() && isEqSymbols(rhs->symbol(), var))
        expression->setRhs(changeExpr);

    changeVarToExpr(expression->lhs(), var, changeExpr);
    changeVarToExpr(expression->rhs(), var, changeExpr);
}

static void changeVarToExpr(SgStatement* statement, SgSymbol* var, SgExpression* expr, int startExpr = 0)
{
    if (statement == NULL || var == NULL)
        return;

    for (int i = startExpr; i < 3; ++i)
    {
        SgExpression* ex = statement->expr(i);
        if (ex && ex->symbol() && isEqSymbols(ex->symbol(), var))
        {
            statement->setExpression(i, expr);
            continue;
        }

        changeVarToExpr(ex, var, expr);
    }
}

static void changeIterationVarToCountExpr(LoopGraph* firstLoop, LoopGraph* loop, int dimensions, SgSymbol* var)
{
    SgSymbol* sym = NULL;

    for (int dim = 0; dim < dimensions; ++dim)
    {
        sym = getLoopSymbol(firstLoop);
        if (isEqSymbols(sym, var))
            break;

        firstLoop = firstLoop->children[0];
    }

    SgExpression* countExpr = createIterationCountExpr(firstLoop);
    for (SgStatement* st = loop->loop; st != loop->loop->lastNodeOfStmt(); st = st->lexNext())
        changeVarToExpr(st, var, countExpr);
}

static bool isVarInExpression(SgSymbol* var, SgExpression* ex)
{
    bool res = false;
    if (ex)
    {
        if (ex->variant() == VAR_REF || isArrayRef(ex))
            if (ex->symbol() && isEqSymbols(ex->symbol(), var))
                return true;

        res |= isVarInExpression(var, ex->lhs());
        res |= isVarInExpression(var, ex->rhs());
    }

    return res;
}

static bool varIsChanged(SgSymbol* var, LoopGraph* loop)
{
    for (SgStatement* st = loop->loop; st != loop->loop->lastNodeOfStmt(); st = st->lexNext())
    {
        if (st->variant() == ASSIGN_STAT && isEqSymbols(st->expr(0)->symbol(), var))
            return true;
        
        if (st->variant() == FOR_NODE && isEqSymbols(((SgForStmt*)st)->doName(), var))
            return true;
    }
    
    return false;
}

static bool varIsRead(SgSymbol* var, LoopGraph* loop)
{
    for (SgStatement* st = loop->loop; st != loop->loop->lastNodeOfStmt(); st = st->lexNext())
    {
        int i = 0;
        if (st->variant() == ASSIGN_STAT && isEqSymbols(st->expr(0)->symbol(), var))
            i = 1;

        for (; i < 3; ++i)
            if (st->expr(i) && isVarInExpression(var, st->expr(i)))
                return true;
    }

    return false;
}

static bool varIsChangedBetween(SgSymbol* var, SgStatement* begin, SgStatement* end)
{
    for (SgStatement* st = begin; st != end; st = st->lexNext())
        if (st->variant() == ASSIGN_STAT && isEqSymbols(st->expr(0)->symbol(), var))
            return true;

    return false;
}

static bool varIsUsedBetween(SgSymbol* var, SgStatement* begin, SgStatement* end)
{
    if (begin == NULL || end == NULL)
        return false;

    for (SgStatement* st = begin; st != end; st = st->lexNext())
        for (int i = 0; i < 3; ++i)
            if (st->expr(i) && isVarInExpression(var, st->expr(i)))
                return true;

    return false;
}

static bool isAntiVarDependency(SgSymbol* var, SgForStmt* loop)
{
    bool is_used = false;
    for (SgStatement* st = loop; st != loop->lastNodeOfStmt(); st = st->lexNext())
    {
        if (st->variant() == ASSIGN_STAT && isEqSymbols(st->expr(0)->symbol(), var))
        {
            for (int i = 1; i < 3; ++i)
                if (st->expr(i) && isVarInExpression(var, st->expr(i)))
                    return true;

            return is_used;
        }
        
        for (int i = 0; i < 3; ++i)
            if (st->expr(i) && isVarInExpression(var, st->expr(i)))
                is_used = true;
    }

    return false;
}

static void replaceIterationVar(LoopGraph* firstLoop, LoopGraph* loop, int dimensions, SgSymbol* var, SgSymbol* newSymbol)
{
    LoopGraph* first = firstLoop;
    for (int i = 0; i < dimensions; ++i)
    {
        SgSymbol* loopSymbol = getLoopSymbol(first);
        if (isEqSymbols(loopSymbol, var))
            break;

        first = first->children[0];
    }
    SgExpression* countExpr = createIterationCountExpr(first);
    SgStatement* st = new SgAssignStmt(*new SgVarRefExp(newSymbol), *countExpr);
    firstLoop->loop->insertStmtBefore(*st, *firstLoop->loop->controlParent());

    map<SgSymbol*, SgSymbol*> toRename;
    toRename.insert(make_pair(var, newSymbol));
    renameVariablesInLoop(loop, toRename);
}

static bool varIsReallyNotPrivate(SgSymbol* var, const LoopGraph* loop, map<LoopGraph*, set<SgSymbol*>>& mapPrivates)
{
    bool res = false;
    for (SgStatement* st = loop->loop; st != loop->loop->lastNodeOfStmt(); st = st->lexNext())
    {
        if (st->variant() == FOR_NODE)
        {
            for (LoopGraph* child : loop->children)
            {
                if (child->loop->id() == st->id())
                {
                    if (isSymbolInSet(mapPrivates[child], var))
                        res = false;
                    else
                        res = varIsReallyNotPrivate(var, child, mapPrivates);

                    st = st->lastNodeOfStmt();
                }
            }
        }
        else
        {
            for (int i = 0; i < 3; ++i)
                if (st->expr(i) && isVarInExpression(var, st->expr(i)))
                    return true;
        }
    }

    return res;
}

static void insertStmtBeforeOuterLoop(SgStatement* st, SgStatement* loop)
{
    while (loop->controlParent()->variant() == FOR_NODE)
        loop = loop->controlParent();

    loop->insertStmtBefore(*st, *loop->controlParent());
}

static void correctInheritedUsage(LoopGraph* firstLoop, LoopGraph* loop, int dimensions, set<SgSymbol*>& firstLoopVars, set<SgSymbol*>& loopVars)
{
    set<SgSymbol*> firstLoopIterationVars;
    fillIterationVariables(firstLoop, firstLoopIterationVars, dimensions);
    set<SgSymbol*> loopIterationVars;
    fillIterationVariables(loop, loopIterationVars, dimensions);

    LoopGraph* first = firstLoop;
    for (int i = 0; i < dimensions; ++i)
    {
        SgSymbol* var = getLoopSymbol(first);
        if (isSymbolInSet(loopVars, var) && !isSymbolInSet(loopIterationVars, var))
        {
            if (varIsChanged(var, loop))
            {
                checkNull(isSgForStmt(loop->loop), convertFileName(__FILE__).c_str(), __LINE__);
                if (isAntiVarDependency(var, (SgForStmt*)loop->loop))
                {
                    SgSymbol* newSymbol = copySymbolAndRename(var);
                    eraseSymbolFromSet(loopVars, var);
                    loopVars.insert(newSymbol);
                    makeDeclaration(loop->loop, vector<SgSymbol*> { newSymbol });
                    replaceIterationVar(first, loop, dimensions, var, newSymbol);
                }
            }
            else
            {
                eraseSymbolFromSet(loopVars, var);
                changeIterationVarToCountExpr(first, loop, dimensions, var);
            }
        }

        if (i != dimensions - 1)
            first = first->children[0];
    }
    
    // TODO:
    // установка значений итерационным переменным, которые в результате объединения заменяются на другие переменные
    // временно убрано из прохода
    /*first = firstLoop;
    for (int i = 0; i < dimensions; ++i)
    {
        SgSymbol* loopVar = getLoopSymbol(loop);
        SgSymbol* firstLoopVar = getLoopSymbol(first);
        if (!isEqSymbols(loopVar, firstLoopVar))
        {
            SgExpression* countExpr = createIterationCountExpr(loop);
            if (isSymbolInSet(firstLoopVars, loopVar))
            {
                SgStatement* st = new SgAssignStmt(*new SgVarRefExp(loopVar), *countExpr);
                firstLoop->loop->insertStmtAfter(*st, *firstLoop->loop->controlParent());
            }
            else
            {
                SgStatement* st = new SgAssignStmt(*new SgVarRefExp(loopVar), *countExpr);
                firstLoop->loop->insertStmtBefore(*st, *firstLoop->loop->controlParent());
            }
        }

        if (i != dimensions - 1)
        {
            first = first->children[0];
            loop = loop->children[0];
        }
    }*/
}

// TODO: улучшить анализ зависимостей по массивам
static bool hasDependenciesBetweenArrays(LoopGraph* firstLoop, LoopGraph* loop, int dimensions)
{
    set<DIST::Array*> readWriteFrist, readWriteSecond;
    vector<pair<LoopGraph*, set<DIST::Array*>*>> loops = { make_pair(firstLoop, &readWriteFrist), make_pair(loop, &readWriteSecond) };

    for (auto& loop : loops)
    {
        const LoopGraph* currLoop = loop.first;
        
        for (int d = 0; d < dimensions; ++d)
        {
            checkNull(currLoop, convertFileName(__FILE__).c_str(), __LINE__);

            *(loop.second) = loop.first->usedArraysAll;

            if (currLoop->children.size())
                currLoop = currLoop->children[0];
            else
                currLoop = NULL;
        }
    }

    //есть ли вообще одинаковые массивы, которые читаются и пишутся в объединяемых циклах и отображены на них
    set<DIST::Array*> intersect;
    std::set_intersection(readWriteFrist.begin(), readWriteFrist.end(), readWriteSecond.begin(), readWriteSecond.end(), inserter(intersect, intersect.begin()));
    if (intersect.size() == 0)
        return false;

    for (auto& array : intersect)
    {
        const LoopGraph* currLoop[2] = { firstLoop, loop };

        for (int d = 0; d < dimensions; ++d)
        {
            //по измерениям массива отображение на цикл вложенности d
            vector<set<pair<int, int>>> coefsRead[2], coefsWrite[2];

            checkNull(currLoop[0], convertFileName(__FILE__).c_str(), __LINE__);
            checkNull(currLoop[1], convertFileName(__FILE__).c_str(), __LINE__);
            
            for (int k = 0; k < 2; ++k)
            {
                auto it = currLoop[k]->readOpsForLoop.find(array);
                if (it != currLoop[k]->readOpsForLoop.end())
                {
                    if (coefsRead[k].size() == 0)
                        coefsRead[k].resize(it->second.size());

                    for (int z = 0; z < it->second.size(); ++z)
                        if (it->second[z].coefficients.size())
                            for (auto& coef : it->second[z].coefficients)
                                coefsRead[k][z].insert(coef.first);
                }

                auto itW = currLoop[k]->writeOpsForLoop.find(array);
                if (itW != currLoop[k]->writeOpsForLoop.end())
                {
                    if (coefsWrite[k].size() == 0)
                        coefsWrite[k].resize(itW->second.size());

                    for (int z = 0; z < itW->second.size(); ++z)
                        if (itW->second[z].coefficients.size())
                            for (auto& coef : itW->second[z].coefficients)
                                coefsWrite[k][z].insert(coef.first);
                }
            }

            //нет записей, значит нет зависимости
            bool nulWrite = true;
            for (auto& wr : coefsWrite)
                for (auto& elem : wr)
                    if (elem.size() != 0)
                        nulWrite = false;

            if (nulWrite)
                continue;

            // если чтение в одном цикле и запись (и наоборот) в другом идут по разным правилам, то пока что это зависимость.
            // здесь можно уточнить.

            const int len = std::max(coefsWrite[0].size(), coefsRead[0].size());
            int countW[2] = { 0, 0 };
            int countR[2] = { 0, 0 };

            for (int L = 0; L < 2; ++L)
                for (int z = 0; z < coefsWrite[L].size(); ++z)
                    countW[L] += (coefsWrite[L][z].size() ? 1 : 0);

            for (int L = 0; L < 2; ++L)
                for (int z = 0; z < coefsRead[L].size(); ++z)
                    countR[L] += (coefsRead[L][z].size() ? 1 : 0);

            for (int p = 0; p < len; ++p)
            {
                if (coefsWrite[1].size() && coefsWrite[0].size())
                    if (coefsWrite[0][p].size() != 0 && coefsWrite[1][p].size() != 0)
                        if (coefsWrite[0][p] != coefsWrite[1][p])
                            return true;

                if (coefsRead[1].size() && coefsWrite[0].size())
                    if (coefsWrite[0][p].size() != 0 && coefsRead[1][p].size() != 0)
                        if (coefsWrite[0][p] != coefsRead[1][p])
                            return true;

                if (coefsWrite[1].size() && coefsRead[0].size())
                    if (coefsWrite[1][p].size() != 0 && coefsRead[0][p].size() != 0)
                        if (coefsWrite[1][p] != coefsRead[0][p])
                            return true;
                

                //отображение на разные измерения
                if (coefsWrite[1].size() && coefsWrite[0].size())
                {
                    if (coefsWrite[0][p].size() != 0 && coefsWrite[1][p].size() == 0 && countW[1] ||
                        coefsWrite[0][p].size() == 0 && coefsWrite[1][p].size() != 0 && countW[0])
                        return true;
                }

                if (coefsRead[1].size() && coefsWrite[0].size())
                {
                    if (coefsWrite[0][p].size() != 0 && coefsRead[1][p].size() == 0 && countR[1] ||
                        coefsWrite[0][p].size() == 0 && coefsRead[1][p].size() != 0 && countW[0])
                        return true;
                }

                if (coefsWrite[1].size() && coefsRead[1].size())
                {
                    if (coefsWrite[1][p].size() != 0 && coefsRead[0][p].size() == 0 && countR[0] ||
                        coefsWrite[1][p].size() == 0 && coefsRead[0][p].size() != 0 && countW[1])
                        return true;
                }

                //где то нет правил отображения вообще, но есть факт его наличия. 
                if ( ((coefsWrite[0].size() == 0 && coefsRead[0].size() == 0) && (countW[0] == 0 && countR[0] == 0)) 
                    ||
                    ((coefsWrite[1].size() == 0 && coefsRead[1].size() == 0) && (countW[1] == 0 && countR[1] == 0)) )
                    return true;
            }
            
            currLoop[0] = (currLoop[0]->children.size()) ? currLoop[0]->children[0] : NULL;
            currLoop[1] = (currLoop[1]->children.size()) ? currLoop[1]->children[0] : NULL;
        }
    }

    return false;
}

static int solveVarsCollisions(LoopGraph* firstLoop, LoopGraph* loop, int dimensions, map<LoopGraph*, set<SgSymbol*>>& mapPrivates)
{
    set<SgSymbol*> firstLoopAllVars = getAllVariables<SgSymbol*>(firstLoop->loop, firstLoop->loop->lastNodeOfStmt(), set<int> { VAR_REF, ARRAY_REF });
    set<SgSymbol*> loopAllVars = getAllVariables<SgSymbol*>(loop->loop, loop->loop->lastNodeOfStmt(), set<int> { VAR_REF, ARRAY_REF });

    if (mapPrivates.find(loop) == mapPrivates.end())
        printInternalError(convertFileName(__FILE__).c_str(), __LINE__);
    set<SgSymbol*> loopPrivates = mapPrivates[loop];

    if (mapPrivates.find(firstLoop) == mapPrivates.end())
        printInternalError(convertFileName(__FILE__).c_str(), __LINE__);
    set<SgSymbol*> firstLoopPrivates = mapPrivates[firstLoop];

    set<SgSymbol*> loopIterationVars;
    fillIterationVariables(loop, loopIterationVars, dimensions);

    for (SgSymbol* var : firstLoopAllVars)
    {
        if (var->type()->variant() == T_ARRAY || !varIsReallyNotPrivate(var, firstLoop, mapPrivates))
            continue;
                
        if (isSymbolInSet(loopPrivates, var) || isSymbolInSet(firstLoopPrivates, var))
            continue;

        bool isChangedInFirst = false, isChangedInSecond = false;
        bool isReadInFirst = false, isReadInSecond = false;
        if (isSymbolInSet(loopAllVars, var) && varIsReallyNotPrivate(var, loop, mapPrivates))
        {
            isChangedInFirst = varIsChanged(var, firstLoop);
            isChangedInSecond = varIsChanged(var, loop);

            isReadInFirst = varIsRead(var, firstLoop);
            isReadInSecond = varIsRead(var, loop);

            if (isChangedInFirst && isReadInSecond || isChangedInSecond && isReadInFirst)
                return -1;
        }
    }

    if (hasDependenciesBetweenArrays(firstLoop, loop, dimensions))
        return -1;

    correctInheritedUsage(firstLoop, loop, dimensions, firstLoopAllVars, loopAllVars);

    for (SgSymbol* var : loopPrivates)
        eraseSymbolFromSet(firstLoopPrivates, var);

    for (SgSymbol* var : loopIterationVars)
    {
        eraseSymbolFromSet(firstLoopPrivates, var);
        eraseSymbolFromSet(loopPrivates, var);

        LoopGraph* parentLoop = loop;
        while (parentLoop)
        {
            auto pair = mapPrivates.find(parentLoop);
            if (pair == mapPrivates.end())
                printInternalError(convertFileName(__FILE__).c_str(), __LINE__);
            
            eraseSymbolFromSet(pair->second, var);
            parentLoop = parentLoop->parent;
        }
    }

    vector<SgSymbol*> symbolsToDeclare;

    set<SgSymbol*> varsFromLoopToRename;
    getIntersection(firstLoopAllVars, loopPrivates, varsFromLoopToRename);
    set<SgSymbol*> varsFromFirstLoopToRename;
    getIntersection(loopAllVars, firstLoopPrivates, varsFromFirstLoopToRename);

    map<SgSymbol*, SgSymbol*> symbolsToRename;
    for (SgSymbol* symbol : varsFromLoopToRename)
    {
        if (varIsReallyNotPrivate(symbol, firstLoop, mapPrivates))
        {
            SgSymbol* newSymbol = copySymbolAndRename(symbol);
            symbolsToDeclare.push_back(newSymbol);
            symbolsToRename.insert(make_pair(symbol, newSymbol));
        }
    }

    renamePrivatesInMap(loop, symbolsToRename, mapPrivates);
    renameVariablesInLoop(loop, symbolsToRename);

    symbolsToRename.clear();
    for (SgSymbol* symbol : varsFromFirstLoopToRename)
    {
        if (varIsReallyNotPrivate(symbol, loop, mapPrivates))
        {
            SgSymbol* newSymbol = copySymbolAndRename(symbol);
            symbolsToDeclare.push_back(newSymbol);
            symbolsToRename.insert(make_pair(symbol, newSymbol));
        }
    }

    renamePrivatesInMap(firstLoop, symbolsToRename, mapPrivates);
    renameVariablesInLoop(firstLoop, symbolsToRename);

    makeDeclaration(symbolsToDeclare, loop->loop->GetOriginal());
    
    LoopGraph* loopToInsert = firstLoop;
    for (int i = 0; i < dimensions; ++i)
    {
        auto pair = mapPrivates.find(loopToInsert);
        if (pair == mapPrivates.end())
            printInternalError(convertFileName(__FILE__).c_str(), __LINE__);

        for (SgSymbol* privateVar : mapPrivates[loop])
            pair->second.insert(privateVar);
        
        if (i != dimensions - 1)
            loopToInsert = loopToInsert->children[0];
    }

    LoopGraph* toDelete = loop;
    for (int i = 0; i < dimensions; ++i)
    {
        mapPrivates.erase(toDelete);
        if (i != dimensions - 1)
            toDelete = toDelete->children[0];
    }

    return 0;
}

static int getNewStep(SgForStmt* firstLoopStmt, SgForStmt* loopStmt)
{
    SgExpression* step1 = firstLoopStmt->step();
    SgExpression* step2 = loopStmt->step();
    int step1Val = 1, step2Val = 1;

    if (step1 != NULL)
        step1Val = step1->valueInteger();
    if (step2 != NULL)
        step2Val = step2->valueInteger();

    int stepGcd = gcd(std::abs(step1Val), std::abs(step2Val));

    int newStep = stepGcd;

    int startDifference = 0;
    if (firstLoopStmt->start()->isInteger() && loopStmt->start()->isInteger())
    {
        int start1Val = firstLoopStmt->start()->valueInteger();
        int start2Val = loopStmt->start()->valueInteger();

        startDifference = std::abs(start1Val - start2Val);
    }
    else
    {
        bool var1Minus = false, var2Minus = false;
        int var1Add = 0, var2Add = 0;
        getSimpleExprVarParams(firstLoopStmt->start(), &var1Minus, &var1Add);
        getSimpleExprVarParams(loopStmt->start(), &var2Minus, &var2Add);

        startDifference = std::abs(var1Add - var2Add);
    }

    if (startDifference != 0)
        newStep = gcd(startDifference, stepGcd);
    
    if (step1Val < 0)
        newStep *= -1;

    return newStep;
}

// returns -1 if impossible to get global bounds
static void getGlobalBounds(SgForStmt* firstLoopStmt, SgForStmt* loopStmt, pair<SgExpression*, SgExpression*>& globalBounds)
{
    int compStart = compareSimpleExpressions(firstLoopStmt->start(), loopStmt->start());
    int compEnd = compareSimpleExpressions(firstLoopStmt->end(), loopStmt->end());

    int step = 1;
    if (firstLoopStmt->step())
        step = firstLoopStmt->step()->valueInteger();

    SgExpression* start = NULL, * end = NULL;
    if (step > 0)
    {
        if (compStart == 0)  // firstLoopStmt->start() < loopStmt->start()
            start = &firstLoopStmt->start()->copy();
        else
            start = &loopStmt->start()->copy();

        if (compEnd == 2)  // firstLoopStmt->end() > loopStmt->end()
            end = &firstLoopStmt->end()->copy();
        else
            end = &loopStmt->end()->copy();
    }
    else
    {
        if (compStart == 2)  // firstLoopStmt->start() > loopStmt->start()
            start = &firstLoopStmt->start()->copy();
        else
            start = &loopStmt->start()->copy();

        if (compEnd == 0)  // firstLoopStmt->end() < loopStmt->end()
            end = &firstLoopStmt->end()->copy();
        else
            end = &loopStmt->end()->copy();
    }

    globalBounds = make_pair(start, end);
}

static SgStatement* makeIfStatementForBounds(SgForStmt* loopStmt, const pair<SgExpression*, SgExpression*>& globalBounds,
                                             SgSymbol* loopSymbol, int newStep)
{
    SgExpression* step = NULL;
    int stepVal = 1;
    if (loopStmt->step() != NULL)
    {
        step = &loopStmt->step()->copy();
        stepVal = loopStmt->step()->valueInteger();
    }
    else
        step = new SgValueExp(1);

    SgExpression* stepCond = NULL;
    if (stepVal != newStep)
    {
        // MOD(var - start, step) .eq. 0
        SgExpression* varRef = new SgExpression(VAR_REF, NULL, NULL, &loopSymbol->copy());
        SgExpression* subt = new SgExpression(SUBT_OP, varRef, &loopStmt->start()->copy());
        vector<SgExpression*> vec = { step, subt };
        SgExpression* list = makeExprList(vec, false);
        SgSymbol* symbol = new SgSymbol(FUNCTION_NAME, "mod");
        SgExpression* mod = new SgExpression(FUNC_CALL, list, NULL, symbol);
        stepCond = new SgExpression(EQ_OP, mod, new SgValueExp(0));
    }

    SgExpression* startCond = NULL;
    if (!isEqExpressions(loopStmt->start(), globalBounds.first))
    {
        SgExpression* varRef = new SgExpression(VAR_REF, NULL, NULL, &loopSymbol->copy());
        if (stepVal > 0)
            startCond = new SgExpression(GTEQL_OP, varRef, &loopStmt->start()->copy());
        else
            startCond = new SgExpression(LTEQL_OP, varRef, &loopStmt->start()->copy());
    }

    SgExpression* endCond = NULL;
    if (!isEqExpressions(loopStmt->end(), globalBounds.second))
    {
        SgExpression* varRef = new SgExpression(VAR_REF, NULL, NULL, &loopSymbol->copy());
        if (stepVal > 0)
            endCond = new SgExpression(LTEQL_OP, varRef, &loopStmt->end()->copy());
        else
            endCond = new SgExpression(GTEQL_OP, varRef, &loopStmt->end()->copy());
    }

    SgExpression* loopCond = NULL;
    if (startCond)
        loopCond = startCond;

    if (endCond)
    {
        if (loopCond)
            loopCond = new SgExpression(AND_OP, loopCond, endCond);
        else
            loopCond = endCond;
    }

    if (stepCond)
    {
        if (loopCond)
            loopCond = new SgExpression(AND_OP, loopCond, stepCond);
        else
            loopCond = stepCond;
    }

    SgIfStmt* ifStmt = NULL;
    if (loopCond)
        ifStmt = new SgIfStmt(*loopCond);

    return ifStmt;
}

static void moveBodyWithDiffBounds(SgForStmt* from, SgForStmt* to, const pair<SgExpression*, SgExpression*>& globalBounds, int newStep)
{
    map<SgSymbol*, SgSymbol*> symbols;
    symbols.insert(make_pair(from->doName(), to->doName()));

    SgStatement* ifStmt = makeIfStatementForBounds(from, globalBounds, to->doName(), newStep);
    if (ifStmt)
    {
        to->lastExecutable()->insertStmtAfter(*ifStmt, *to);
        moveBody(from, ifStmt, symbols);
    }
    else
        moveBody(from, to, symbols);
}

static void moveCommentsAndAttributes(SgStatement* loopFrom, SgStatement* loopTo)
{
    if (loopFrom->comments())
        loopTo->addComment(string(loopFrom->comments()).c_str());

    if (loopFrom->numberOfAttributes())
    {
        auto data = getAttributes<SgStatement*, SgStatement*>(loopFrom, set<int>{ SPF_ANALYSIS_DIR });
        for (auto& elem : data)
            loopTo->addAttribute(SPF_ANALYSIS_DIR, elem, sizeof(SgStatement*));
    }
}

static void combineWithDifferentBounds(const LoopGraph* firstLoop, const LoopGraph* loop)
{
    SgForStmt* firstLoopStmt = isSgForStmt(firstLoop->loop->GetOriginal());
    checkNull(firstLoop, convertFileName(__FILE__).c_str(), __LINE__);

    SgForStmt* loopStmt = isSgForStmt(loop->loop->GetOriginal());
    checkNull(loopStmt, convertFileName(__FILE__).c_str(), __LINE__);

    SgExpression* step1 = firstLoopStmt->step();
    int step1Val = 1;
    if (step1 != NULL)
        step1Val = step1->valueInteger();

    pair<SgExpression*, SgExpression*> globalBounds;
    getGlobalBounds(firstLoopStmt, loopStmt, globalBounds);
    
    int newStep = getNewStep(firstLoopStmt, loopStmt);

    SgStatement* firstLoopIfStmt = makeIfStatementForBounds(firstLoopStmt, globalBounds, firstLoopStmt->doName(), newStep);

    firstLoopStmt->setStart(*globalBounds.first);
    firstLoopStmt->setEnd(*globalBounds.second);
    if (newStep != step1Val)
        firstLoopStmt->setStep(*new SgValueExp(newStep));

    if (firstLoopIfStmt)
    {
        map<SgSymbol*, SgSymbol*> symbols;
        moveBody(firstLoopStmt, firstLoopIfStmt, symbols);
        firstLoopStmt->lastExecutable()->insertStmtAfter(*firstLoopIfStmt, *firstLoopStmt);
    }

    moveBodyWithDiffBounds(loopStmt, firstLoopStmt, globalBounds, newStep);
    moveCommentsAndAttributes(loopStmt, firstLoopStmt);
    
    loopStmt->extractStmt();
}

/**
 * Собственно объединение
 */
static bool combine(LoopGraph* firstLoop, const vector<LoopGraph*>& nextLoops, set<LoopGraph*>& combinedLoops,
                    map<LoopGraph*, set<SgSymbol*>>& mapPrivates, vector<Messages>& messages, const map<LoopGraph*, depGraph*>& depInfoForLoopGraph,
                    int& countOfTransform)
{
    bool wasCombine = false;
    for (LoopGraph* loop : nextLoops)
    {
        if (!loop->isFor)
            return wasCombine;

        int perfectLoop = std::min(firstLoop->perfectLoop, loop->perfectLoop);
        const LoopGraph* curLoop = firstLoop;
        for (int i = 0; i < perfectLoop; ++i)
        {
            SgForStmt* loopStmt = isSgForStmt(curLoop->loop->GetOriginal());
            checkNull(loopStmt, convertFileName(__FILE__).c_str(), __LINE__);

            if (curLoop->hasLimitsToCombine() || hasGotoToStatement(loopStmt))
                return false;

            if (i != perfectLoop - 1)
                curLoop = curLoop->children[0];
        }
        
        map<SgSymbol*, SgSymbol*> symbolsFromLoopToRename;
        int dimensionsForCombine = getDeepestDimForCombine(firstLoop, loop, perfectLoop);

        LoopGraph* loopToReverse = NULL;
        if (dimensionsForCombine == 0)
            dimensionsForCombine = getDeepestDimToReverse(firstLoop, loop, perfectLoop, &loopToReverse, depInfoForLoopGraph);

        if (dimensionsForCombine || canBeCombinedWithDiffBounds(firstLoop, loop))
        {
            if (solveVarsCollisions(firstLoop, loop, dimensionsForCombine, mapPrivates) == -1)
                break;

            if (dimensionsForCombine)
            {
                reverseLoop(loopToReverse, dimensionsForCombine);
                compareIterationVars(firstLoop, loop, dimensionsForCombine, symbolsFromLoopToRename);

                SgForStmt* innerMainLoop = getInnerLoop(firstLoop, dimensionsForCombine);
                moveBody(getInnerLoop(loop, dimensionsForCombine), innerMainLoop, symbolsFromLoopToRename);
                moveCommentsAndAttributes(loop->loop, firstLoop->loop);
                
                loop->loop->extractStmt();
            }
            else
            {
                dimensionsForCombine = 1;
                combineWithDifferentBounds(firstLoop, loop);
            }

            combinedLoops.insert(loop);
            wasCombine = true;

            //move in structure
            LoopGraph* deep = loop, *parent = firstLoop;
            for (int p = 0; p < dimensionsForCombine - 1; ++p)
            {
                deep = deep->children[0];
                parent = parent->children[0];
            }

            for (auto& toMove : deep->children)
            {
                parent->children.push_back(toMove);
                toMove->parent = parent;
            }
            deep->children.clear();
            firstLoop->recalculatePerfect();

            wstring strR, strE;
            __spf_printToLongBuf(strE, L"Loops on line %d and on line %d were combined", firstLoop->lineNum, loop->lineNum);
            __spf_printToLongBuf(strR, R100, firstLoop->lineNum, loop->lineNum);
            messages.push_back(Messages(NOTE, firstLoop->lineNum, strR, strE, 2005));

            __spf_print(1, "Loops on lines %d and %d were combined\n", firstLoop->lineNum, loop->lineNum);
            countOfTransform++;
        }
        else
            break;
    }

    return wasCombine;
}

/**
 * Возвращает следующие loopsAmount циклов после nextAfterThis.
 * Если loopsAmount < 0, вернёт все последующие циклы, до первого оператора-не-цикла.
 */
static vector<LoopGraph*> getNextLoops(LoopGraph* nextAfterThis, vector<LoopGraph*>& loops, int loopsAmount)
{
    vector<LoopGraph*> result;
    SgStatement* lastSt = nextAfterThis->loop->lastNodeOfStmt();

    int z = 0;
    for (; z < loops.size(); ++z)
        if (loops[z] == nextAfterThis)
            break;
    if (z == loops.size())
        return result;
    else
        z++;

    for (; z < loops.size(); ++z)
    {
        if (loopsAmount == 0)
            break;

        SgStatement* loopSt = loops[z]->loop->GetOriginal();
        if (lastSt->lexNext() != loopSt)
            break;
        else
        {
            lastSt = loopSt->lastNodeOfStmt();
            result.push_back(loops[z]);
            --loopsAmount;
        }
    }

    return result;
}

static bool tryToCombine(vector<LoopGraph*>& loopGraphs, map<LoopGraph*, set<SgSymbol*>>& mapPrivates, 
                         vector<Messages>& messages, const map<LoopGraph*, depGraph*>& depInfoForLoopGraph,
                         int& countOfTransform)
{
    if (loopGraphs.size() == 0)
        return false;

    bool change = false;
    set<LoopGraph*> loopsToDelete;
    vector<LoopGraph*> newloopGraphs;

    vector<LoopGraph*> loops = loopGraphs;
    for (size_t z = 0; z < loops.size(); ++z)
    {
        LoopGraph* loop = loops[z];
        newloopGraphs.push_back(loop);
        if (!loop->isFor)
            continue;

        vector<LoopGraph*> nextLoops = getNextLoops(loop, loopGraphs, -1);

        set<LoopGraph*> combinedLoops;
        change = false;
        if (nextLoops.size())
            change = combine(loop, nextLoops, combinedLoops, mapPrivates, messages, depInfoForLoopGraph, countOfTransform);

        for (LoopGraph* combined : combinedLoops)
        {
            loopsToDelete.insert(combined);
            loopGraphs.erase(find(loopGraphs.begin(), loopGraphs.end(), combined));
        }

        if (change)
        {
            LoopGraph* loopParent = loop;
            while (loopParent->parent)
                loopParent = loopParent->parent;
            addIterationVarsToMap(loopParent, mapPrivates);

            LoopGraph* outerParent = loop;
            while (outerParent->parent)
                outerParent = outerParent->parent;

            outerParent->recalculatePerfect();
        }

        z += combinedLoops.size();
    }
    loopGraphs = newloopGraphs;

    for (LoopGraph* elem : loopsToDelete)
        delete elem;

    if (change == false)
    {
        for (LoopGraph* ch : loopGraphs)
        {
            bool res = tryToCombine(ch->children, mapPrivates, messages, depInfoForLoopGraph, countOfTransform);
            change |= res;
        }
    }
    return change;
}

int combineLoops(SgFile* file, vector<LoopGraph*>& loopGraphs, vector<Messages>& messages, 
                 const pair<string, int>& onPlace, const map<LoopGraph*, depGraph*>& depInfoForLoopGraph,
                 int& countOfTransform)
{
    map<int, LoopGraph*> mapGraph;
    createMapLoopGraph(loopGraphs, mapGraph);

    map<LoopGraph*, set<SgSymbol*>> mapPrivates;
    fillMapPrivateVars(loopGraphs, mapPrivates);
    
    if (onPlace.second > 0)
    {
        if (onPlace.first != file->filename())
            return 0;
        else
        {
            const int onLine = onPlace.second;

            auto it = mapGraph.find(onLine);
            if (it == mapGraph.end())
                printInternalError(convertFileName(__FILE__).c_str(), __LINE__);

            vector<LoopGraph*> nextLoops = getNextLoops(it->second, it->second->parent ? it->second->parent->children : loopGraphs, 1);
            set<LoopGraph*> combinedLoops;
            bool wasCombine = false;
            if (nextLoops.size())
                wasCombine = combine(it->second, nextLoops, combinedLoops, mapPrivates, messages, depInfoForLoopGraph, countOfTransform);

            return 0;
        }
    }

    bool change = true;
    int count = 0;
    while (change)
    {
        change = tryToCombine(loopGraphs, mapPrivates, messages, depInfoForLoopGraph, countOfTransform);
        if (change)
            count++;
    }
    
    /*printf(" === \n");
    for (auto& elem : mapPrivates)
    {
        printf("for loop %d\n", elem.first->lineNum);
        for (auto& priv : elem.second)
            printf("  %s\n", priv->identifier());
    }*/

    return 0;
}