MWCC/compiler_and_linker/unsorted/COptimizer.c

#include "compiler/COptimizer.h"
#include "compiler/CompilerTools.h"
#include "compiler/CClass.h"
#include "compiler/CDecl.h"
#include "compiler/CError.h"
#include "compiler/CExpr.h"
#include "compiler/CFunc.h"
#include "compiler/CInt64.h"
#include "compiler/CMachine.h"
#include "compiler/CParser.h"
#include "compiler/InlineAsm.h"
#include "compiler/enode.h"
#include "compiler/objects.h"
#include "compiler/CodeGen.h"
#include "compiler/Switch.h"
#include "compiler/Exceptions.h"
#include "compiler/IrOptimizer.h"
#include "cos.h"

COptBlock *basicblocks;
Boolean copt_isleaffunction;
static Boolean stmtchanged;
static COptBlock *currentblock;
static ENode *mexpr;
static short setbytes;
static COptCSE *csenodes[MAXEXPR];
static COptCSEList *cselist;
static short extravars;
static Boolean cse_found;
static Boolean cse_invals;
static Boolean static_for_inlines;
static short replaces;
static ENode *objrefnode;
static int objrefnodes;

static short bitmasks[] = {
        1, 2, 4, 8, 0x10, 0x20, 0x40, 0x80,
        0x100, 0x200, 0x400, 0x800, 0x1000, 0x2000, 0x4000, 0x8000
};

// forward decls
static COptCSE *cse_expression(ENode *expr);

static COptCSE *cse_new(ENode *expr) {
    COptCSE *cse = oalloc(sizeof(COptCSE));
    cse->expr = expr;
    cse->replaced = NULL;
    cse->block = currentblock;
    cse->mexpr = mexpr;
    cse->left = NULL;
    cse->right = NULL;
    cse->x1C = 1;
    return cse;
}

static COptCSE *cse_append(COptCSE *cse, ENode *expr) {
    COptCSEList *list = oalloc(sizeof(COptCSEList));
    list->next = cselist;
    cselist = list;
    list->cse = cse;
    list->expr = expr;
    return cse;
}

static void cse_cleanup(void) {
    COptCSEList *scanlist;
    COptCSEList *prevlist;
    COptCSE *scan;
    COptCSE *prev;
    short op;

    scanlist = cselist;
    while (scanlist && !scanlist->cse)
        scanlist = scanlist->next;
    cselist = scanlist;

    if (scanlist) {
        do {
            prevlist = scanlist;
            do {
                scanlist = scanlist->next;
            } while (scanlist && !scanlist->cse);
            prevlist->next = scanlist;
        } while (scanlist);
    }

    for (op = 0; op < MAXEXPR; op++) {
        scan = csenodes[op];
        while (scan && scan->x1C < 0)
            scan = scan->next;
        csenodes[op] = scan;

        if (scan) {
            do {
                prev = scan;
                do {
                    scan = scan->next;
                } while (scan && scan->x1C < 0);
                prev->next = scan;
            } while (scan);
        }
    }
}

static void cse_inval(COptCSE *cse) {
    COptCSEList *scanlist;
    COptCSE *scan;
    short op;

    if (cse) {
        for (scanlist = cselist; scanlist; scanlist = scanlist->next) {
            if (scanlist->cse == cse) {
                scanlist->cse = NULL;
                scanlist->expr = NULL;
            }
        }

        cse->x1C = -1;
        cse->left = NULL;
        cse->right = NULL;

        for (op = 0; op < MAXEXPR; op++) {
            for (scan = csenodes[op]; scan; scan = scan->next) {
                if (scan->left == cse || scan->right == cse)
                    cse_inval(scan);
            }
        }
    }
}

static void cse_update_usages(COptCSE *cse, short amount) {
    cse->x1C /= amount;
    if (cse->left)
        cse_update_usages(cse->left, amount);
    if (cse->right)
        cse_update_usages(cse->right, amount);
}

static void cse_replace(ENode *expr, COptCSE *cse) {
    COptCSEList *list;

    for (list = cselist; list; list = list->next) {
        if (list->cse == cse) {
            *list->expr = *expr;
            replaces++;
            list->cse = NULL;
            list->expr = NULL;
        }
    }
}

static short cse_objectcost(Object *obj) {
    if (obj->datatype == DLOCAL && !obj->u.var.info->noregister)
        return 0;
    return 1;
}

static void cse_treereplacemexpr(COptCSE *cse, ENode *from, ENode *to) {
    if (cse->mexpr == from)
        cse->mexpr = to;
    if (cse->left)
        cse_treereplacemexpr(cse->left, from, to);
    if (cse->right)
        cse_treereplacemexpr(cse->right, from, to);
}

static Boolean cse_issubcse(COptCSE *a, COptCSE *b) {
    if (a == b)
        return 1;
    if (b->left && cse_issubcse(a, b->left))
        return 1;
    if (b->right && cse_issubcse(a, b->right))
        return 1;

    return 0;
}

static short cse_cost(COptCSE *cse) {
    short cost;

    if (cse) {
        while (ENODE_IS(cse->expr, ETYPCON) && cse->expr->rtype->type == cse->expr->data.monadic->rtype->type && cse->expr->rtype->size == cse->expr->data.monadic->rtype->size)
            cse = cse->left;

        if (ENODE_IS_INDIRECT_TO(cse->expr, EOBJREF))
            return cse_objectcost(cse->expr->data.monadic->data.objref);

        cost = 1;
        if (!copts.optimizesize) {
            if (ENODE_IS3(cse->expr, EMUL, EDIV, EMODULO))
                cost = 2;
        }
        return cse_cost(cse->left) + cse_cost(cse->right) + cost;
    }

    return 0;
}

static void cse_remove(void) {
    short op; // r27
    COptCSE *cse; // r25
    COptCSE *best_cse; // r28
    int best_cost; // r30
    Object *obj; // r31
    Boolean did_replacement; // r24
    VarInfo *vi; // r27
    ObjectList *objlist;
    ENode *expr1;
    ENode *expr2;
    ENode *expr3;
    ENode *expr4;
    ENode *mexprsave;
    COptCSEList *list;
    short cost;

    while (1) {
        op = 0;
        best_cse = NULL;
        best_cost = 0;
        did_replacement = 0;

        for (; op < MAXEXPR; op++) {
            switch (op) {
                case EINTCONST:
                case EFLOATCONST:
                case EOBJREF:
                case EVECTOR128CONST:
                    break;
                default:
                    for (cse = csenodes[op]; cse; cse = cse->next) {
                        if (cse->x1C > 1 && (cost = cse_cost(cse)) > 4) {
                            if (cse->replaced) {
                                replaces = 0;
                                cse_replace(cse->replaced, cse);
                                CError_ASSERT(348, replaces >= 1);
                                cse_found = 1;
                                did_replacement = 1;
                                cse_update_usages(cse, cse->x1C);
                            } else {
                                if ((cse->x1C * cost) > best_cost) {
                                    best_cse = cse;
                                    best_cost = cse->x1C * cost;
                                }
                            }
                        }
                    }
                    break;
            }
        }

        if (did_replacement)
            continue;
        if (!best_cse || extravars >= 256)
            return;

        obj = lalloc(sizeof(Object));
        memclrw(obj, sizeof(Object));
        obj->name = CParser_GetUniqueName();
        obj->type = cse->expr->rtype;
        obj->datatype = DLOCAL;
        vi = CodeGen_GetNewVarInfo();
        obj->u.var.info = vi;

        objlist = lalloc(sizeof(ObjectList));
        objlist->object = obj;
        objlist->next = locals;
        locals = objlist;

        vi->used = 1;
        vi->usage = cse->x1C + 1;

        expr1 = lalloc(sizeof(ENode));
        expr1->type = EOBJREF;
        expr1->cost = 0;
        expr1->flags = 0;
        expr1->data.objref = obj;
        expr1->rtype = CDecl_NewPointerType(obj->type);

        expr2 = lalloc(sizeof(ENode));
        expr2->type = EINDIRECT;
        expr2->cost = 1;
        expr2->flags = 0;
        expr2->data.monadic = expr1;
        expr2->rtype = obj->type;

        expr3 = lalloc(sizeof(ENode));
        expr3->type = EASS;
        expr3->cost = -1;
        expr3->flags = 0;
        expr3->rtype = obj->type;
        expr3->data.diadic.left = expr2;
        expr3->data.diadic.right = lalloc(sizeof(ENode));

        *expr3->data.diadic.right = *cse->expr;
        cse->expr = expr3->data.diadic.right;

        replaces = 0;
        cse_replace(expr2, cse);
        cse->replaced = expr2;

        if (replaces < 2)
            CError_FATAL(390);
        else
            cse_found = 1;

        expr4 = lalloc(sizeof(ENode));
        *expr4 = *cse->mexpr;

        cse->mexpr->type = ECOMMA;
        cse->mexpr->data.diadic.left = expr3;
        cse->mexpr->data.diadic.right = expr4;

        cse_update_usages(cse, cse->x1C);
        extravars++;

        mexprsave = cse->mexpr;
        if (mexpr == mexprsave)
            mexpr = expr4;

        for (list = cselist; list; list = list->next) {
            if (list->cse && !cse_issubcse(list->cse, cse)) {
                if (list->cse->mexpr == mexprsave)
                    list->cse->mexpr = expr4;
                if (list->cse->expr == mexprsave)
                    list->cse->expr = expr4;
                if (list->expr == mexprsave)
                    list->expr = expr4;
            }
        }
    }
}

static COptCSE *cse_intconst(ENode *expr) {
    COptCSE *cse = csenodes[EINTCONST];

    for (; cse; cse = cse->next) {
        if (expr->rtype == cse->expr->rtype)
            if (CInt64_Equal(cse->expr->data.intval, expr->data.intval))
                return cse;
    }

    cse = cse_new(expr);
    cse->next = csenodes[EINTCONST];
    csenodes[EINTCONST] = cse;
    return cse;
}

static COptCSE *cse_floatconst(ENode *expr) {
    COptCSE *cse = csenodes[EFLOATCONST];
    Float val = expr->data.floatval;

    for (; cse; cse = cse->next) {
        if (CMach_CalcFloatDiadicBool(cse->expr->rtype, cse->expr->data.floatval, TK_LOGICAL_EQ, val))
            if (expr->rtype == cse->expr->rtype)
                return cse;
    }

    cse = cse_new(expr);
    cse->next = csenodes[EFLOATCONST];
    csenodes[EFLOATCONST] = cse;
    return cse;
}

static COptCSE *cse_vectorconst(ENode *expr) {
    COptCSE *cse = csenodes[EVECTOR128CONST];
    MWVector128 val = expr->data.vector128val;

    for (; cse; cse = cse->next) {
        if (CMach_CalcVectorDiadicBool(cse->expr->rtype, &cse->expr->data.vector128val, TK_LOGICAL_EQ, &val))
            if (expr->rtype == cse->expr->rtype)
                return cse;
    }

    cse = cse_new(expr);
    cse->next = csenodes[EVECTOR128CONST];
    csenodes[EVECTOR128CONST] = cse;
    return cse;
}

static COptCSE *cse_objref(ENode *expr) {
    COptCSE *cse = csenodes[EOBJREF];
    Object *obj = expr->data.objref;

    for (; cse; cse = cse->next) {
        if (cse->expr->data.objref == obj)
            return cse;
    }

    cse = cse_new(expr);
    cse->next = csenodes[EOBJREF];
    csenodes[EOBJREF] = cse;
    return cse;
}

static COptCSE *cse_add_monadic_node(ENode *outer, COptCSE *innercse) {
    COptCSE *cse;

    if (!innercse)
        return NULL;

    for (cse = csenodes[outer->type]; cse; cse = cse->next) {
        if (cse->left == innercse && cse->expr->rtype == outer->rtype) {
            CError_ASSERT(524, cse->expr != outer);
            cse->x1C++;
            return cse;
        }
    }

    cse = cse_new(outer);
    cse->next = csenodes[outer->type];
    csenodes[outer->type] = cse;
    cse->left = innercse;
    return cse;
}

static COptCSE *cse_add_typecon_node(ENode *outer, COptCSE *innercse) {
    COptCSE *cse;

    if (!innercse)
        return NULL;

    for (cse = csenodes[outer->type]; cse; cse = cse->next) {
        if (cse->left == innercse && cse->expr->rtype == outer->rtype) {
            CError_ASSERT(552, cse->expr != outer);
            cse->x1C++;
            return cse;
        }
    }

    cse = cse_new(outer);
    cse->next = csenodes[outer->type];
    csenodes[outer->type] = cse;
    cse->left = innercse;
    return cse;
}

static COptCSE *cse_add_diadic_node(ENode *outer, COptCSE *leftcse, COptCSE *rightcse) {
    COptCSE *cse;

    if (!leftcse || !rightcse)
        return NULL;

    for (cse = csenodes[outer->type]; cse; cse = cse->next) {
        if (cse->left == leftcse && cse->right == rightcse) {
            CError_ASSERT(581, cse->expr != outer);
            cse->x1C++;
            return cse;
        }
    }

    cse = cse_new(outer);
    cse->next = csenodes[outer->type];
    csenodes[outer->type] = cse;
    cse->left = leftcse;
    cse->right = rightcse;
    return cse;
}

static COptCSE *cse_add_commdiadic_node(ENode *outer, COptCSE *leftcse, COptCSE *rightcse) {
    COptCSE *cse;

    if (!leftcse || !rightcse)
        return NULL;

    for (cse = csenodes[outer->type]; cse; cse = cse->next) {
        if ((cse->left == leftcse && cse->right == rightcse) || (cse->left == rightcse && cse->right == leftcse)) {
            CError_ASSERT(612, cse->expr != outer);
            cse->x1C++;
            return cse;
        }
    }

    cse = cse_new(outer);
    cse->next = csenodes[outer->type];
    csenodes[outer->type] = cse;
    cse->left = leftcse;
    cse->right = rightcse;
    return cse;
}

static void sfind_objref(ENode *expr) {
    while (1) {
        switch (expr->type) {
            case ETYPCON:
                expr = expr->data.monadic;
                break;
            case EOBJREF:
                objrefnode = expr;
                objrefnodes++;
                return;
            case EADD:
            case ESUB:
                sfind_objref(expr->data.diadic.left);
                expr = expr->data.diadic.right;
                break;
            default:
                return;
        }
    }
}

static ENode *find_objref_node(ENode *expr) {
    objrefnode = NULL;
    objrefnodes = 0;
    sfind_objref(expr);
    if (objrefnodes == 1)
        return objrefnode;
    else
        return NULL;
}

static void cse_mem_modify(void) {
    COptCSE *cse;

    for (cse = csenodes[EINDIRECT]; cse; cse = cse->next) {
        if (ENODE_IS(cse->expr->data.monadic, EOBJREF)) {
            Object *obj = cse->expr->data.monadic->data.objref;
            CError_ASSERT(672, obj->datatype != DALIAS);
            if (obj->datatype == DLOCAL && !obj->u.var.info->noregister)
                continue;
        }

        cse_inval(cse);
    }
}

static void cse_modify_expression(ENode *expr) {
    if (!expr) {
        short op;

        cse_remove();
        for (op = 0; op < MAXEXPR; op++)
            csenodes[op] = NULL;

        cselist = NULL;
        freeoheap();
    } else {
        ENode *objnode;
        Object *obj;
        COptCSE *cse;

        cse_invals = 1;
        if (ENODE_IS(expr, EINDIRECT) && (objnode = find_objref_node(expr->data.monadic))) {
            do {
                obj = objnode->data.objref;
                cse_remove();
                for (cse = csenodes[EINDIRECT]; cse; cse = cse->next) {
                    if ((objnode = find_objref_node(cse->expr->data.monadic)) && obj == objnode->data.objref)
                        cse_inval(cse);
                }

                objnode = find_objref_node(expr->data.monadic);
                if (!objnode) {
                    cse_mem_modify();
                    break;
                }
            } while (obj != objnode->data.objref);
        } else {
            cse_remove();
            cse_mem_modify();
        }
    }
}

static void cse_pascalcall(ENode *expr) {
    ENodeList *list;

    for (list = expr->data.funccall.args; list; list = list->next)
        cse_expression(list->node);

    if (ENODE_IS(expr, EFUNCCALLP))
        cse_expression(expr->data.funccall.funcref);

    cse_remove();
    cse_mem_modify();
}

static Boolean cse_pusharg(ENodeList *exprs, FuncArg *args) {
    Boolean result;

    if (!exprs)
        return 1;

    if (args && args != &elipsis && args != &oldstyle)
        args = args->next;
    if (exprs->next)
        result = cse_pusharg(exprs->next, args);

    cse_expression(exprs->node);
    return result;
}

static void cse_ccall(ENode *expr) {
    if (cse_pusharg(expr->data.funccall.args, expr->data.funccall.functype->args)) {
        if (ENODE_IS(expr, EFUNCCALL))
            cse_expression(expr->data.funccall.funcref);

        cse_remove();
        cse_mem_modify();
    } else {
        cse_modify_expression(NULL);
    }
}

static COptCSE *cse_expression(ENode *expr) {
    ENode *save;
    COptCSE *tmp;
    ENodeType nt = expr->type;

    switch (nt) {
        case EFUNCCALL:
            cse_ccall(expr);
            return NULL;
        case EFUNCCALLP:
            cse_pascalcall(expr);
            return NULL;
        case EPOSTINC:
        case EPOSTDEC:
        case EPREINC:
        case EPREDEC:
            save = mexpr;
            mexpr = expr;
            CError_ASSERT(816, ENODE_IS(expr->data.monadic, EINDIRECT));

            cse_expression(expr->data.monadic->data.monadic);
            cse_modify_expression(expr->data.monadic);
            mexpr = save;
            return NULL;

        case EINDIRECT:
        case EMONMIN:
        case EBINNOT:
        case ELOGNOT:
        case EFORCELOAD:
            return cse_append(cse_add_monadic_node(expr, cse_expression(expr->data.monadic)), expr);

        case ETYPCON:
            return cse_append(cse_add_typecon_node(expr, cse_expression(expr->data.monadic)), expr);

        case EMUL:
        case EMULV:
        case EADDV:
        case EADD:
        case EEQU:
        case ENOTEQU:
        case EAND:
        case EXOR:
        case EOR:
            tmp = cse_expression(expr->data.diadic.left);
            if (expr->type == nt)
                return cse_append(cse_add_commdiadic_node(expr, tmp, cse_expression(expr->data.diadic.right)), expr);
            else
                return NULL;

        case EDIV:
        case EMODULO:
        case ESUBV:
        case ESUB:
        case ESHL:
        case ESHR:
        case ELESS:
        case EGREATER:
        case ELESSEQU:
        case EGREATEREQU:
        case EPMODULO:
        case EROTL:
        case EROTR:
        case EBTST:
            tmp = cse_expression(expr->data.diadic.left);
            if (expr->type == nt)
                return cse_append(cse_add_diadic_node(expr, tmp, cse_expression(expr->data.diadic.right)), expr);
            else
                return NULL;

        case EASS:
        case EMULASS:
        case EDIVASS:
        case EMODASS:
        case EADDASS:
        case ESUBASS:
        case ESHLASS:
        case ESHRASS:
        case EANDASS:
        case EXORASS:
        case EORASS:
            CError_ASSERT(887, ENODE_IS(expr->data.diadic.left, EINDIRECT));
            save = mexpr;
            mexpr = expr;
            cse_expression(expr->data.diadic.right);
            if (expr->type == nt) {
                cse_expression(expr->data.diadic.left->data.monadic);
                cse_modify_expression(expr->data.diadic.left);
                mexpr = save;
                return NULL;
            } else {
                cse_modify_expression(NULL);
                return NULL;
            }

        case ECOMMA:
            cse_expression(expr->data.diadic.left);
            save = mexpr;
            mexpr = expr->data.diadic.right;
            tmp = cse_expression(expr->data.diadic.right);
            mexpr = save;
            return tmp;

        case EINTCONST:
            return cse_intconst(expr);
        case EFLOATCONST:
            return cse_floatconst(expr);
        case EVECTOR128CONST:
            return cse_vectorconst(expr);
        case EOBJREF:
            return cse_objref(expr);

        case EBITFIELD:
            cse_modify_expression(NULL);
            return NULL;

        case ECOND:
            cse_expression(expr->data.cond.cond);
            cse_modify_expression(NULL);
            return NULL;

        case ENULLCHECK:
            cse_expression(expr->data.nullcheck.nullcheckexpr);
            cse_modify_expression(NULL);
            return NULL;

        case ELAND:
        case ELOR:
            cse_expression(expr->data.diadic.left);
            cse_modify_expression(NULL);
            return NULL;

        case ESTRINGCONST:
        case ELABEL:
            return NULL;

        case EPRECOMP:
            CError_FATAL(948);

        default:
            CError_FATAL(951);
            return NULL;
    }
}

static void cse_block(COptBlock *block) {
    Statement *stmt;
    COptBlock *check;
    COptBlockList *scan;
    COptBlock *best;
    short i;
    SInt32 counter;
    UInt32 starttime;

    starttime = COS_GetTicks();
    counter = 0;

    while (1) {
        cse_invals = 0;
        currentblock = block;
        block->x1E = 1;

        for (stmt = block->stmt, i = block->x1C; i > 0; stmt = stmt->next, i--) {
            switch (stmt->type) {
                case ST_EXPRESSION:
                case ST_SWITCH:
                case ST_IFGOTO:
                case ST_IFNGOTO:
                    mexpr = stmt->expr;
                    cse_expression(mexpr);
                    break;
                case ST_RETURN:
                    mexpr = stmt->expr;
                    if (mexpr)
                        cse_expression(mexpr);
                    break;
            }
        }

        i = 0;
        for (scan = block->blocks2; scan; scan = scan->next) {
            check = scan->block;
            if (!check->x1E && check->blocks && !check->blocks->next && check->blocks->block == block) {
                best = check;
                i++;
            }
        }

        if (i != 1)
            break;

        block = best;
        if (COS_GetTicks() > (starttime + 60)) {
            if (counter++ & 1) {
                if (CWDisplayLines(cparamblkptr->context, lines))
                    CError_UserBreak();
            } else {
                if (CWDisplayLines(cparamblkptr->context, lines + 1))
                    CError_UserBreak();
            }
            starttime = COS_GetTicks();
        }

        if (cse_invals)
            cse_cleanup();
    }

    cse_remove();
}

static void CSE(void) {
    COptBlock *block;

    for (block = basicblocks->next; block; block = block->next)
        block->x1E = 0;

    for (block = basicblocks->next; block; block = block->next) {
        if (!block->x1E) {
            short op;

            for (op = 0; op < MAXEXPR; op++)
                csenodes[op] = NULL;

            cselist = NULL;
            cse_found = 0;
            cse_block(block);
            freeoheap();
        }
    }
}

static short TestSetBit(short *set, short bit) {
    return set[bit >> 4] & bitmasks[bit & 15];
}

static void SetSetBit(short *set, short bit) {
    set[bit >> 4] |= bitmasks[bit & 15];
}

UInt32 RegAllocMask(short var) {
    COptBlock *block;
    UInt32 mask = 0;

    for (block = basicblocks; block; block = block->next) {
        if (TestSetBit(block->set1, var) || TestSetBit(block->set2, var))
            mask |= block->allocmask;
    }

    return mask;
}

void MarkRegAllocMask(short var, short bit, Boolean flag) {
    COptBlock *block;
    UInt32 mask = 1 << bit;

    if (flag) {
        for (block = basicblocks; block; block = block->next) {
            if (TestSetBit(block->set1, var) || TestSetBit(block->set2, var))
                block->allocmask |= mask;
        }
    } else {
        for (block = basicblocks; block; block = block->next) {
            block->allocmask |= mask;
        }
    }
}

static COptBlock *newblock(void) {
    COptBlock *block;
    short i;
    short max;

    block = lalloc(sizeof(COptBlock) + (setbytes * 2));
    block->x1E = 0;
    block->next = NULL;
    block->blocks = NULL;
    block->blocks2 = NULL;
    block->allocmask = 0;
    block->set1 = (short *) (((long) block) + sizeof(COptBlock));
    block->set2 = (short *) (((long) block) + setbytes + sizeof(COptBlock));

    for (i = 0, max = setbytes / 2; i < max; i++) {
        block->set1[i] = 0;
        block->set2[i] = 0;
    }

    return block;
}

static void MarkFollow(COptBlock *block) {
    COptBlockList *list;

restart:
    block->x1E = 1;
    if ((list = block->blocks2)) {
        while (1) {
            if (!list->block->x1E) {
                if (!list->next) {
                    block = list->block;
                    goto restart;
                }
                MarkFollow(list->block);
                list = list->next;
            } else {
                list = list->next;
                if (!list)
                    break;
            }
        }
    }
}

static Boolean CheckInit(short var) {
    Boolean result;
    COptBlock *block;

    result = 1;
    for (block = basicblocks; block; block = block->next) {
        if (!block->x1E && TestSetBit(block->set2, var))
            MarkFollow(block);
    }

    for (block = basicblocks; block; block = block->next) {
        if (!block->x1E) {
            if (TestSetBit(block->set1, var))
                result = 0;
        } else {
            block->x1E = 0;
        }
    }

    return result;
}

static void CheckVarInit(void) {
    COptBlock *block;
    VarInfo *vi;
    ObjectList *list;

    for (block = basicblocks; block; block = block->next)
        block->x1E = 0;

    for (list = locals; list; list = list->next) {
        if (list->object->datatype == DLOCAL && !IsTempName(list->object->name) && !is_volatile_object(list->object)) {
            vi = list->object->u.var.info;
            if (vi->used && !CheckInit(vi->varnumber)) {
                if (!IS_TYPE_CLASS(list->object->type) || !CClass_IsEmpty(TYPE_CLASS(list->object->type))) {
                    CError_SetErrorToken(&vi->deftoken);
                    CError_Warning(CErrorStr185, list->object->name->name);
                }
            }
        }
    }
}

static void AddVar(Object *obj, Boolean whichSet) {
    VarInfo *vi;

    if (obj->datatype == DLOCAL) {
        vi = obj->u.var.info;
        if (!whichSet) {
            SetSetBit(currentblock->set1, vi->varnumber);
        } else {
            if (!TestSetBit(currentblock->set1, vi->varnumber))
                SetSetBit(currentblock->set2, vi->varnumber);
        }
    }
}

static void CheckExpr(ENode *expr) {
    ENodeList *list;

    while (1) {
        switch (expr->type) {
            case EINDIRECT:
                if (ENODE_IS(expr->data.monadic, EOBJREF)) {
                    AddVar(expr->data.monadic->data.objref, 0);
                    return;
                }
                expr = expr->data.monadic;
                break;
            case EOBJREF:
                AddVar(expr->data.objref, 1);
                return;
            case EFUNCCALL:
            case EFUNCCALLP:
                CheckExpr(expr->data.funccall.funcref);
                for (list = expr->data.funccall.args; list; list = list->next)
                    CheckExpr(list->node);
                return;
            case ECOND:
                CheckExpr(expr->data.cond.cond);
                CheckExpr(expr->data.cond.expr1);
                CheckExpr(expr->data.cond.expr2);
                return;
            case EASS:
                if (ENODE_IS_INDIRECT_TO(expr->data.diadic.left, EOBJREF)) {
                    CheckExpr(expr->data.diadic.right);
                    AddVar(expr->data.diadic.left->data.monadic->data.objref, 1);
                    return;
                }
            case EMUL:
            case EMULV:
            case EDIV:
            case EMODULO:
            case EADDV:
            case ESUBV:
            case EADD:
            case ESUB:
            case ESHL:
            case ESHR:
            case ELESS:
            case EGREATER:
            case ELESSEQU:
            case EGREATEREQU:
            case EEQU:
            case ENOTEQU:
            case EAND:
            case EXOR:
            case EOR:
            case ELAND:
            case ELOR:
            case EMULASS:
            case EDIVASS:
            case EMODASS:
            case EADDASS:
            case ESUBASS:
            case ESHLASS:
            case ESHRASS:
            case EANDASS:
            case EXORASS:
            case EORASS:
            case ECOMMA:
            case EPMODULO:
            case EROTL:
            case EROTR:
            case EBCLR:
            case EBTST:
            case EBSET:
                CheckExpr(expr->data.diadic.left);
                expr = expr->data.diadic.right;
                break;
            case EPOSTINC:
            case EPOSTDEC:
            case EPREINC:
            case EPREDEC:
            case EMONMIN:
            case EBINNOT:
            case ELOGNOT:
            case EFORCELOAD:
            case ETYPCON:
            case EBITFIELD:
                expr = expr->data.monadic;
                break;
            case ENULLCHECK:
                CheckExpr(expr->data.nullcheck.nullcheckexpr);
                expr = expr->data.nullcheck.condexpr;
                break;
            case EINTCONST:
            case EFLOATCONST:
            case ESTRINGCONST:
            case EPRECOMP:
            case ELABEL:
            case EVECTOR128CONST:
                return;
            default:
                CError_FATAL(1332);
        }
    }
}

static short CheckPath(COptBlock *block, short var) {
    COptBlockList *list;

    if (block->x1E)
        return TestSetBit(block->set1, var);

    block->x1E = 1;
    if (TestSetBit(block->set1, var))
        return -1;
    if (TestSetBit(block->set2, var))
        return 0;

    for (list = block->blocks2; list; list = list->next) {
        if (CheckPath(list->block, var)) {
            SetSetBit(block->set1, var);
            return -1;
        }
    }

    return 0;
}

static void MarkPre(COptBlock *block, short var) {
    COptBlockList *list;

restart:
    block->x1E = 1;
    for (list = block->blocks; list; list = list->next) {
        if (!list->block->x1E) {
            if (!TestSetBit(list->block->set2, var)) {
                SetSetBit(list->block->set1, var);
                if (!list->next) {
                    block = list->block;
                    goto restart;
                }
                MarkPre(list->block, var);
            } else {
                list->block->x1E = 1;
            }
        }
    }
}

static void CheckVarUsage(void) {
    short local;
    COptBlock *block;
    short counter;

    for (currentblock = basicblocks; currentblock; currentblock = currentblock->next) {
        Statement *stmt = currentblock->stmt;
        if (currentblock->x1C > 0 && stmt->type == ST_LABEL && (stmt->flags & StmtFlag_1)) {
            short i;
            for (i = 0; i < localcount; i++)
                SetSetBit(currentblock->set2, i);
        }

        for (counter = currentblock->x1C; counter > 0; counter--) {
            if (stmt->type >= ST_EXPRESSION && stmt->type <= ST_GOTOEXPR && stmt->expr)
                CheckExpr(stmt->expr);
            stmt = stmt->next;
        }
    }

    for (local = 0; local < localcount; local++) {
        for (block = basicblocks; block; block = block->next) {
            if (!block->x1E && TestSetBit(block->set1, local))
                MarkPre(block, local);
        }
        for (block = basicblocks; block; block = block->next) {
            block->x1E = 0;
        }
    }
}

static void SplitCommaExpressions(void) {
    COptBlock *block;
    Statement *stmt;
    ENode *expr;
    Statement *stmtcopy;
    short counter;
    Boolean flag;

    block = basicblocks->next;
    while (block) {
        stmt = block->stmt;
        counter = block->x1C;
        flag = 1;
        while (counter > 0) {
            if (stmt->type >= ST_EXPRESSION && stmt->type <= ST_GOTOEXPR) {
                if ((expr = stmt->expr) && ENODE_IS(expr, ECOMMA)) {
                    stmtcopy = lalloc(sizeof(Statement));
                    *stmtcopy = *stmt;
                    stmt->next = stmtcopy;
                    stmt->type = ST_EXPRESSION;
                    stmt->expr = expr->data.diadic.left;
                    stmtcopy->expr = expr->data.diadic.right;
                    block->x1C++;
                    flag = 0;
                    break;
                }
            }

            stmt = stmt->next;
            counter--;
        }

        if (flag)
            block = block->next;
    }
}

static void BasicBlockAnalyze(Statement *stmt) {
    COptBlock *block;
    ObjectList *objlist;
    COptBlockList *scan;
    COptBlockList *list;
    CLabel *label;
    COptBlock *iblock;
    COptBlock *oblock;
    SwitchCase *swcase;

    setbytes = 2 * ((localcount - 1) / 16) + 2;
    if (copts.globaloptimizer) {
        setbytes += 32;
        extravars = 0;
    }

    block = newblock();
    basicblocks = block;
    block->stmt = NULL;
    block->x1C = 0;

    if (stmt) {
        list = lalloc(sizeof(COptBlockList));
        list->next = NULL;
        block->blocks2 = list;
        list->block = (COptBlock *) stmt;
    }

    for (objlist = arguments; objlist; objlist = objlist->next) {
        SetSetBit(block->set2, objlist->object->u.var.info->varnumber);
    }

    while (stmt) {
        int counter;

        block->next = newblock();
        block = block->next;
        block->stmt = stmt;
        counter = 1;

    innerLoop:
        switch (stmt->type) {
            case ST_ASM:
                label = InlineAsm_GetReferencedLabel(stmt);
                if (!label)
                    goto jumpahead;
                list = lalloc(sizeof(COptBlockList));
                list->next = block->blocks2;
                block->blocks2 = list;
                list->block = (COptBlock *) label->stmt;
                if (stmt->next) {
                    list = lalloc(sizeof(COptBlockList));
                    list->next = block->blocks2;
                    block->blocks2 = list;
                    list->block = (COptBlock *) stmt->next;
                }
                stmt = stmt->next;
                block->x1C = counter;
                continue;
            case ST_NOP:
            case ST_LABEL:
            case ST_ENTRY:
                if (stmt->next && stmt->next->type != ST_LABEL) {
                    stmt = stmt->next;
                    counter++;
                    goto innerLoop;
                }
                break;
            case ST_EXPRESSION:
            case ST_BEGINCATCH:
            case ST_ENDCATCH:
            case ST_ENDCATCHDTOR:
            jumpahead:
                if (stmt->next && stmt->next->type == ST_GOTO) {
                    stmt = stmt->next;
                    counter++;
                    goto innerLoop;
                }
                break;
        }

        switch (stmt->type) {
            case ST_SWITCH:
                label = ((SwitchInfo *) stmt->label)->defaultlabel;
                if (label != cleanreturnlabel) {
                    list = lalloc(sizeof(COptBlockList));
                    list->next = block->blocks2;
                    block->blocks2 = list;
                    list->block = (COptBlock *) label->stmt;
                }
                for (swcase = ((SwitchInfo *) stmt->label)->cases; swcase; swcase = swcase->next) {
                    label = swcase->label;
                    if (label != cleanreturnlabel) {
                        list = lalloc(sizeof(COptBlockList));
                        list->next = block->blocks2;
                        block->blocks2 = list;
                        list->block = (COptBlock *) label->stmt;
                    }
                }
                break;
            case ST_RETURN:
            case ST_EXIT:
            case ST_GOTOEXPR:
                break;
            case ST_GOTO:
            case ST_IFGOTO:
            case ST_IFNGOTO:
            case ST_OVF:
                label = stmt->label;
                if (label != cleanreturnlabel) {
                    list = lalloc(sizeof(COptBlockList));
                    list->next = block->blocks2;
                    block->blocks2 = list;
                    list->block = (COptBlock *) label->stmt;
                }
                if (stmt->type == ST_GOTO)
                    break;
            default:
                if (stmt->next) {
                    list = lalloc(sizeof(COptBlockList));
                    list->next = block->blocks2;
                    block->blocks2 = list;
                    list->block = (COptBlock *) stmt->next;
                }
                break;
        }

        stmt = stmt->next;
        block->x1C = counter;
    }

    for (oblock = basicblocks; oblock; oblock = oblock->next) {
        for (scan = oblock->blocks2; scan; scan = scan->next) {
            stmt = (Statement *) scan->block;
            for (iblock = basicblocks->next; iblock; iblock = iblock->next) {
                if (iblock->stmt == stmt) {
                    scan->block = iblock;
                    list = lalloc(sizeof(COptBlockList));
                    list->next = iblock->blocks;
                    iblock->blocks = list;
                    list->block = oblock;
                    break;
                }
            }

            CError_ASSERT(1602, iblock);
        }
    }

    SplitCommaExpressions();
    CheckVarUsage();
}

static CLabel *finallabel(CLabel *label, Statement *stmt) {
    Statement *scan;

    for (scan = label->stmt; scan; scan = scan->next) {
        if (scan->type > ST_LABEL) {
            if (scan == stmt)
                return label;
            if (scan->type == ST_GOTO) {
                if (scan->label != label)
                    stmtchanged = 1;
                return scan->label;
            }
            return label;
        }
    }

    return label;
}

static void optimizegoto(Statement *stmt) {
    Statement *scan;

    for (scan = stmt->next; scan; scan = scan->next) {
        if (stmt->label->stmt == scan) {
            stmt->type = ST_NOP;
            stmtchanged = 1;
            return;
        }
        if (scan->type > ST_LABEL)
            break;
    }

    stmt->label = finallabel(stmt->label, stmt);
}

static void removeif(Statement *stmt, Boolean flag) {
    if (((stmt->type == ST_IFGOTO) && flag) || ((stmt->type == ST_IFNGOTO) && !flag)) {
        Statement *copy = lalloc(sizeof(Statement));
        *copy = *stmt;
        copy->type = ST_GOTO;
        stmt->next = copy;
    }
    stmt->type = ST_EXPRESSION;
    stmtchanged = 1;
}

static void optimizeif(Statement *stmt) {
    Statement *scan;
    Statement *scan2;
    Boolean flag;

    if (iszero(stmt->expr)) {
        removeif(stmt, 0);
        return;
    }
    if (isnotzero(stmt->expr)) {
        removeif(stmt, 1);
        return;
    }

    for (scan = stmt->next, flag = 0; scan; scan = scan->next) {
        if (scan->type > ST_LABEL) {
            if (scan->type == ST_GOTO) {
                if (scan->label == stmt->label) {
                    stmt->type = ST_EXPRESSION;
                    stmtchanged = 1;
                    return;
                }

                if (!flag) {
                    for (scan2 = scan->next; scan2; scan2 = scan2->next) {
                        if (scan2->type > ST_LABEL)
                            break;
                        if (stmt->label->stmt == scan2) {
                            stmt->label = scan->label;
                            scan->type = ST_NOP;
                            if (stmt->type == ST_IFGOTO)
                                stmt->type = ST_IFNGOTO;
                            else
                                stmt->type = ST_IFGOTO;
                            stmtchanged = 1;
                            stmt->label = finallabel(stmt->label, stmt);
                            return;
                        }
                    }
                }
            } else if (scan->type == ST_RETURN && !scan->expr && !static_for_inlines && !flag) {
                for (scan2 = scan->next; scan2; scan2 = scan2->next) {
                    if (scan2->type > ST_LABEL)
                        break;
                    if (stmt->label->stmt == scan2) {
                        stmt->label = cleanreturnlabel;
                        needs_cleanup = 1;
                        scan->type = ST_NOP;
                        if (stmt->type == ST_IFGOTO)
                            stmt->type = ST_IFNGOTO;
                        else
                            stmt->type = ST_IFGOTO;
                        stmtchanged = 1;
                        return;
                    }
                }
            }
            break;
        }

        if (scan->type == ST_LABEL)
            flag = 1;

        if (stmt->label->stmt == scan) {
            stmt->type = ST_EXPRESSION;
            stmtchanged = 1;
            return;
        }
    }

    stmt->label = finallabel(stmt->label, stmt);
}

static void optimizeswitch(Statement *stmt) {
    SwitchInfo *info;
    SwitchCase *swcase;

    info = (SwitchInfo *) stmt->label;
    CError_ASSERT(1746, info && info->cases && info->defaultlabel);

    info->defaultlabel = finallabel(info->defaultlabel, stmt);
    for (swcase = info->cases; swcase; swcase = swcase->next)
        swcase->label = finallabel(swcase->label, stmt);

    if (ENODE_IS(stmt->expr, EINTCONST)) {
        for (swcase = info->cases; swcase; swcase = swcase->next) {
            if (CInt64_GreaterEqual(swcase->min, stmt->expr->data.intval) && CInt64_LessEqual(swcase->max, stmt->expr->data.intval))
                break;
        }

        stmt->type = ST_GOTO;
        stmt->label = swcase ? swcase->label : info->defaultlabel;
    }
}

static void removeunusedlabels(Statement *stmt) {
    Statement *scan;
    CLabel *label;
    SwitchCase *swcase;
    ExceptionAction *action;

    for (scan = stmt; scan; scan = scan->next)
        scan->marked = 0;

    for (scan = stmt; scan; scan = scan->next) {
        switch (scan->type) {
            case ST_GOTO:
            case ST_IFGOTO:
            case ST_IFNGOTO:
            case ST_OVF:
                if (scan->label->stmt)
                    scan->label->stmt->marked = 1;
                break;
            case ST_SWITCH:
                ((SwitchInfo *) scan->label)->defaultlabel->stmt->marked = 1;
                for (swcase = ((SwitchInfo *) scan->label)->cases; swcase; swcase = swcase->next)
                    swcase->label->stmt->marked = 1;
                break;
            case ST_ASM:
                if ((label = InlineAsm_GetReferencedLabel(scan)))
                    label->stmt->marked = 1;
                if ((label = InlineAsm_GetReferencedLabel2(scan)))
                    label->stmt->marked = 1;
                break;
            case ST_BEGINLOOP:
                ((LoopInfo *) scan->expr)->stmt->marked = 1;
                break;
            case ST_ENDLOOP:
                if (scan->next->type == ST_GOTO && scan->next->next->type == ST_LABEL)
                    scan->next->next->marked = 1;
                break;
            default:
                for (action = scan->dobjstack; action; action = action->prev) {
                    if (action->type == EAT_CATCHBLOCK) {
                        action->data.catch_block.catch_label->stmt->marked = 1;
                        action->data.catch_block.catch_label->stmt->flags = action->data.catch_block.catch_label->stmt->flags | StmtFlag_1;
                    } else if (action->type == EAT_SPECIFICATION) {
                        action->data.specification.unexp_label->stmt->marked = 1;
                        action->data.specification.unexp_label->stmt->flags = action->data.specification.unexp_label->stmt->flags | StmtFlag_1;
                    }
                }
        }
    }

    for (scan = stmt; scan; scan = scan->next) {
        if (scan->type == ST_LABEL && !scan->marked && !(scan->flags & StmtFlag_1)) {
            scan->type = ST_NOP;
            stmtchanged = 1;
        }
    }
}

static void optimizebranches(Statement *stmt) {
    removeunusedlabels(stmt);
    while (stmt) {
        switch (stmt->type) {
            case ST_GOTO:
                optimizegoto(stmt);
                break;
            case ST_IFGOTO:
            case ST_IFNGOTO:
                optimizeif(stmt);
                break;
            case ST_SWITCH:
                optimizeswitch(stmt);
                break;
        }
        stmt = stmt->next;
    }
}

void SetVarUsage(Object *obj, Boolean noregister) {
    VarInfo *vi;
    CError_ASSERT(1875, obj->datatype != DALIAS);

    if (obj->datatype == DLOCAL || obj->datatype == DNONLAZYPTR) {
        vi = obj->u.var.info;
        vi->used = 1;
        if (!copts.globaloptimizer) {
            if (copts.optimizesize)
                vi->usage++;
            else
                vi->usage += curstmtvalue;
        }

        if (noregister)
            vi->noregister = 1;
    }
}

static void checkexpression(ENode *expr) {
    ENodeList *list;

    while (1) {
        switch (expr->type) {
            case EOBJREF:
                SetVarUsage(expr->data.objref, 1);
                return;
            case EINDIRECT:
                if (ENODE_IS(expr->data.monadic, EOBJREF)) {
                    SetVarUsage(expr->data.monadic->data.objref, 0);
                    return;
                }
                expr = expr->data.monadic;
                break;
            case EFUNCCALL:
            case EFUNCCALLP:
                copt_isleaffunction = 0;
                checkexpression(expr->data.funccall.funcref);
                for (list = expr->data.funccall.args; list; list = list->next)
                    checkexpression(list->node);
                return;
            case ECOND:
            case ECONDASS:
                checkexpression(expr->data.cond.cond);
                checkexpression(expr->data.cond.expr1);
                checkexpression(expr->data.cond.expr2);
                return;
            case EMUL:
            case EMULV:
            case EDIV:
            case EMODULO:
            case EADDV:
            case ESUBV:
            case EADD:
            case ESUB:
            case ESHL:
            case ESHR:
            case ELESS:
            case EGREATER:
            case ELESSEQU:
            case EGREATEREQU:
            case EEQU:
            case ENOTEQU:
            case EAND:
            case EXOR:
            case EOR:
            case ELAND:
            case ELOR:
            case EASS:
            case EMULASS:
            case EDIVASS:
            case EMODASS:
            case EADDASS:
            case ESUBASS:
            case ESHLASS:
            case ESHRASS:
            case EANDASS:
            case EXORASS:
            case EORASS:
            case ECOMMA:
            case EPMODULO:
            case EROTL:
            case EROTR:
            case EBCLR:
            case EBTST:
            case EBSET:
                checkexpression(expr->data.diadic.left);
                expr = expr->data.diadic.right;
                break;
            case EPOSTINC:
            case EPOSTDEC:
            case EPREINC:
            case EPREDEC:
            case EMONMIN:
            case EBINNOT:
            case ELOGNOT:
            case EFORCELOAD:
            case ETYPCON:
            case EBITFIELD:
                expr = expr->data.monadic;
                break;
            case ENULLCHECK:
                checkexpression(expr->data.nullcheck.nullcheckexpr);
                expr = expr->data.nullcheck.condexpr;
                break;
            case EINTCONST:
            case EFLOATCONST:
            case EPRECOMP:
            case ELABEL:
            case EVECTOR128CONST:
                return;
            case ESTRINGCONST:
                return;
            default:
                CError_FATAL(1998);
        }
    }
}

static void checklocalusage(Statement *stmt) {
    Statement *scan;

    for (scan = stmt; scan; scan = scan->next) {
        if (scan->type >= ST_EXPRESSION && scan->type <= ST_GOTOEXPR && scan->expr) {
            curstmtvalue = scan->value;
            checkexpression(scan->expr);
        } else if (scan->type == ST_ASM) {
            curstmtvalue = scan->value;
            InlineAsm_CheckLocalUsage(scan);
        }
    }
}

static void colorcode(Statement *stmt) {
    CLabel *label;
    SwitchCase *swcase;

    while (stmt && !stmt->marked) {
        stmt->marked = 1;
        switch (stmt->type) {
            case ST_GOTOEXPR:
                return;
            case ST_IFGOTO:
            case ST_IFNGOTO:
            case ST_OVF:
                colorcode(stmt->label->stmt);
                break;
            case ST_GOTO:
            case ST_EXIT:
                stmt = stmt->label->stmt;
                continue;
            case ST_RETURN:
                return;
            case ST_SWITCH:
                for (swcase = ((SwitchInfo *) stmt->label)->cases; swcase; swcase = swcase->next)
                    colorcode(swcase->label->stmt);
                stmt = ((SwitchInfo *) stmt->label)->defaultlabel->stmt;
                continue;
            case ST_ASM:
                if ((label = InlineAsm_GetReferencedLabel(stmt)))
                    colorcode(label->stmt);
                if ((label = InlineAsm_GetReferencedLabel2(stmt)))
                    colorcode(label->stmt);
                break;
            case ST_ENDLOOP:
                if (stmt->next && stmt->next->type == ST_GOTO) {
                    stmt = stmt->next;
                    stmt->marked = 1;
                }
                break;
            case ST_NOP:
            case ST_LABEL:
            case ST_EXPRESSION:
            case ST_ENTRY:
            case ST_BEGINCATCH:
            case ST_ENDCATCH:
            case ST_ENDCATCHDTOR:
            case ST_BEGINLOOP:
                break;
            default:
                CError_FATAL(2096);
        }
        stmt = stmt->next;
    }
}

static void removeunusedcode(Statement *stmt) {
    Statement *scan;

    for (scan = stmt; scan; scan = scan->next)
        scan->marked = 0;

    colorcode(stmt);
    for (scan = stmt; scan; scan = scan->next) {
        if (!scan->marked && (scan->flags & StmtFlag_1))
            colorcode(scan);
    }

    for (scan = stmt; scan; scan = scan->next) {
        if (!scan->marked && scan->type != ST_NOP) {
            scan->type = ST_NOP;
            stmtchanged = 1;
        }
    }
}

static void COpt_ReturnCheck(Object *obj, Statement *stmt) {
    if ((copts.pedantic || copts.cplusplus) && obj && TYPE_FUNC(obj->type)->functype != &stvoid) {
        while (stmt) {
            if (!stmt->next && stmt->type != ST_GOTO && stmt->type != ST_RETURN) {
                CError_Warning(CErrorStr184);
                break;
            }

            if (stmt->type == ST_RETURN && !stmt->expr && !(stmt->flags & StmtFlag_8)) {
                CError_Warning(CErrorStr184);
                break;
            }

            stmt = stmt->next;
        }
    }
}

static void COpt_Optimize(Object *obj, Statement *stmt) {
    Statement **ptr;

    do {
        stmtchanged = 0;
        optimizebranches(stmt->next);
        removeunusedcode(stmt->next);
    } while (stmtchanged);

    ptr = &stmt->next;
    while (*ptr) {
        if ((*ptr)->type == ST_NOP)
            *ptr = (*ptr)->next;
        else
            ptr = &(*ptr)->next;
    }
}

static void COpt_ELABELCallBack(ENode *expr) {
    CError_ASSERT(2195, expr->data.label->stmt && expr->data.label->stmt->type == ST_LABEL);
    expr->data.label->stmt->flags = expr->data.label->stmt->flags | StmtFlag_1;
}

void COpt_SimpleOptimizer(Object *obj, Statement *stmt) {
    Statement *scan;

    for (scan = stmt; scan; scan = scan->next) {
        if ((scan->type >= ST_EXPRESSION && scan->type <= ST_GOTOEXPR) && scan->expr)
            CExpr_SearchExprTree(scan->expr, COpt_ELABELCallBack, 1, ELABEL);
    }

    static_for_inlines = 1;
    cleanreturnlabel = NULL;
    COpt_Optimize(obj, stmt);
    COpt_ReturnCheck(obj, stmt);
}

Statement *COpt_Optimizer(Object *obj, Statement *stmt) {
    copt_isleaffunction = 1;
    if (copts.globaloptimizer)
        stmt = IRO_Optimizer(obj, stmt);

    static_for_inlines = 0;
    COpt_Optimize(obj, stmt);

    if (obj && !(obj->qual & Q_INLINE))
        COpt_ReturnCheck(obj, stmt);

    checklocalusage(stmt->next);
    return stmt;
}