icopy.c

CC386 is a general-purpose 32-bit C compiler. It is not an optimizing compiler but given that the co

                                                            clearbit(l->p_cgen,
                                                                (int)l1->data);
                                                            setbit(l->p_ckill, 
                                                                (int)l1->data);
                                                            l1 = l1->link;
                                                        }
                                                    }
                                                }
                                            }
                                        }
                                    }
                                }
                            }
                        }
                    }
                    break;
                case i_gosub:
                    for (i = 0; i < copy_count; i++)
                    {
                        IMODE *s = copyarray[i]->ans;
                        switch (s->offset->nodetype)
                        {
                        case en_nacon:
                        case en_napccon:
                        case en_nalabcon:
                        case en_labcon:
                        case en_absacon:
                            if (s->mode == i_direct)
                            {
                                clearbit(l->p_cgen, i);
                                setbit(l->p_ckill, i);
                            }
                            else if (s->mode == i_ind){}
                            break;
                        }
                        s = copyarray[i]->dc.left;
                        switch (s->offset->nodetype)
                        {
                        case en_nacon:
                        case en_napccon:
                        case en_nalabcon:
                        case en_labcon:
                        case en_absacon:
                            if (s->mode == i_direct)
                            {
                                clearbit(l->p_cgen, i);
                                setbit(l->p_ckill, i);
                            }
                            else if (s->mode == i_ind){}
                            break;
                        }
                    }
                    break;
            }
            ptrindex(list, l, temparray4);
            list = list->fwd;
        }
    }
}

//-------------------------------------------------------------------------

static void CalculateCopyEqns(void)
{
    int i, changed, j;
    for (i = 0; i < blocknum; i++)
        memcpy(blockarray[i]->block->p_cout, blockarray[i]->block->p_cgen,
            copybytes);
    do
    {
        changed = FALSE;
        for (i = 0; i < blocknum; i++)
        {
            BLOCK *t = blockarray[dfst[i]]->block;
            BLOCKLIST *l = t->flowback;
            if (l)
                memset(t->p_cin, 0xff, copybytes);
            while (l)
            {
                for (j = 0; j < copybytes; j++)t->p_cin[j] &= l->block
                    ->p_cout[j];
                l = l->link;
            }
            for (j = 0; j < copybytes; j++)
            {
                int v = t->p_cout[j];
                t->p_cout[j] = t->p_cgen[j] | (t->p_cin[j] &~t->p_ckill[j]);
                changed |= (v != t->p_cout[j]);
            }
        }
    }
    while (changed)
        ;

}

//-------------------------------------------------------------------------

static int ScanForCopy(BLOCK *l, int index)
{
    QUAD *list = l->head;
    QUAD *match = copyarray[index];
    BLOCKLIST *s;
    IMODE *im,  *ima;
    QUAD *t;
    LIST *l1;
    int i, ptr, j;
    int stopped = FALSE;
    memcpy(temparray4, l->p_cin, sourcebytes *pointer_count);
    while (list && list->back != l->tail)
    {
        switch (list->dc.opcode)
        {
            case i_assn:
            case i_add:
            case i_sub:
            case i_udiv:
            case i_umod:
            case i_sdiv:
            case i_smod:
            case i_umul:
            case i_smul:
            case i_lsl:
            case i_lsr:
            case i_asl:
            case i_asr:
            case i_neg:
            case i_not:
            case i_and:
            case i_or:
            case i_eor:
            case i_setne:
            case i_sete:
            case i_setc:
            case i_seta:
            case i_setnc:
            case i_setbe:
            case i_setl:
            case i_setg:
            case i_setle:
            case i_setge:
                if (list->ans == match->dc.left || list->ans == match->ans)
                {
                    stopped = TRUE;
                    break;
                }
                if (list->ans->mode == i_ind)
                {
                    int ptr = findPointer(list->ans);
                    if (ptr < pointer_count)
                    {
                        if (isset(temparray4 + ptr * sourcebytes, 0))
                        {
                            stopped = TRUE;
                            break;
                        }
                        else
                        for (i = 1; i < source_count; i++)
                        {
                            if (isset(temparray4 + ptr * sourcebytes, i))
                            {
                                SYM *sp = varsp(sourcearray[i]->ans->offset);
                                if (sp->imvalue == match->dc.left || sp
                                    ->imvalue == match->dc.right)
                                {
                                    stopped = TRUE;
                                    break;
                                }
                            }
                        }
                    }
                }
                else if (list->ans->mode == i_direct)
                {
                    ptr = findPointer(list->ans);
                    if (ptr < pointer_count)
                    {
                        SYM *sp = varsp(list->ans->offset);
                        if (sp)
                        {
                            l1 = findans(copyhash, sp->imind);
                            if (l1)
                            {
                                stopped = TRUE;
                                break;
                            }
                        }
                    }
                }
                // fall through
            case i_coswitch:
            case i_jc:
            case i_ja:
            case i_je:
            case i_jnc:
            case i_jbe:
            case i_jne:
            case i_jl:
            case i_jg:
            case i_jle:
            case i_jge:
                if (stopped && used(match, list))
                    return FALSE;
                break;
            case i_parm:
                if (list->dc.left->mode == i_immed)
                {
                    SYM *sp = varsp(list->dc.left->offset);
                    if (sp)
                    {
                        if (sp->imvalue == match->dc.left || sp->imvalue ==
                            match->ans)
                        {
                            stopped = TRUE;
                            break;
                        }
                    }
                }
                else if (list->dc.left->mode == i_direct)
                {
                    SYM *sp = varsp(list->dc.left->offset);
                    if (sp)
                    {
                        int ptr = findPointer(list->dc.left);
                        if (ptr < pointer_count)
                        {
                            if (isset(temparray4, 0))
                            {
                                stopped = TRUE;
                                break;
                            }
                            else
                            {
                                for (i = 1; i < source_count; i++)
                                {
                                    if (isset(temparray4 + ptr * sourcebytes, i)
                                        )
                                    {
                                        SYM *sp = varsp(sourcearray[i]->ans
                                            ->offset);
                                        if (sp->imvalue == match->dc.left || sp
                                            ->imvalue == match->dc.right)
                                        {
                                            stopped = TRUE;
                                            break;
                                        }
                                    }
                                }
                            }
                        }
                    }
                }
                if (stopped && used(match, list))
                    return FALSE;
                break;
            case i_gosub:
                for (i = 0; i < copy_count; i++)
                {
                    if (copyarray[i] != list)
                    {
                        IMODE *s = copyarray[i]->ans;
                        switch (s->offset->nodetype)
                        {
                        case en_nacon:
                        case en_napccon:
                        case en_nalabcon:
                        case en_labcon:
                        case en_absacon:
                            if (s == match->dc.left || s == match->ans)
                            {
                                stopped = TRUE;
                                break;
                            }
                            break;
                        }
                    }
                }
                break;
        }
        ptrindex(list, l, temparray4);
        list = list->fwd;
    }
    return TRUE;
}

//-------------------------------------------------------------------------

IMODE *replace(IMODE *im, QUAD *match)
{
    SYM *sp;
    if (!im)
        return im;
    if (im->mode != i_ind && im->mode != i_direct)
        return im;
    sp = varsp(im->offset);
    if (!sp)
        return im;
    if (sp->imvalue == match->ans)
    {
        if (sp->imvalue == im)
            return match->dc.left;
        else
        {
            sp = varsp(match->dc.left->offset);
            return sp->imind;
        }
    }
    return im;
}

//-------------------------------------------------------------------------

static void ReplaceCopies(void)
{
    int i, j;
    for (i = blocknum - 1; i >= 0; i--)
    {
        BLOCK *l = blockarray[dfst[i]]->block;
        for (j = 0; j < copy_count; j++)
            if (isset(l->p_cin, j))
                if (!ScanForCopy(l, j))
                    setbit(temparray5, j);
    }
    for (i = 0; i < blocknum; i++)
    {
        BLOCK *l = blockarray[i]->block;
        for (j = 0; j < copy_count; j++)
        {
            if (!isset(temparray5, j) && isset(l->p_cin, j))
            {
                QUAD *list = l->head;
                QUAD *match = copyarray[j];
                while (list && list->back != l->tail)
                {
                    if (list->ans && list->ans->mode == i_ind)
                        list->ans = replace(list->ans, match);
                    list->dc.right = replace(list->dc.right, match);
                    list->dc.left = replace(list->dc.left, match);
                    list = list->fwd;
                }
            }
        }
    }
    for (j = 0; j < copy_count; j++)
    if (!isset(temparray5, j))
    {
        QUAD *match = copyarray[j];
        SYM *sp = varsp(match->ans->offset);
        if (!prm_debug || sp && sp->storage_class == sc_temp)
        {
            //            match->fwd->back = match->back ;
            //            match->back->fwd = match->fwd ;
        }
    }
}

//-------------------------------------------------------------------------

void CopyPropagation(void)
{
    return ;
    copyhash = oalloc(sizeof(LIST3*) * CHASH);
    CountCopies();
    CreateBitmaps();
    CalculateCopyBasics();
    CalculateCopyEqns();
    ReplaceCopies();
    #ifdef DUMP_GCSE_INFO
        dump_copies();
    #endif 
}