If statement branch prediction issue

I am implementing a pattern search algorithm that has a vital if statement that seems to be unpredictable in it's result. Random files are searched and thus sometimes the branch predictions are okay and sometimes they can be terrible if the file is completely random. My goal is to eliminate the if statement and I have tried but it has yielded slow results like preallocating a vector. The number of pattern possibilities can be very large so preallocating takes up a lot of time. I therefore have the dynamic vector where I initialize them all with NULL up front and then check with the if statement if a pattern is present. The if seems to be killing me and specifically the cmp assembly statement. Bad branch predictions are scrapping the pipeline a lot and causing huge slow downs. Any ideas would be great as to eliminate the if statement at line 17...stuck in a rut.

for (PListType i = 0; i < prevLocalPListArray->size(); i++)
{
    vector<vector<PListType>*> newPList(256, NULL);

    vector<PListType>* pList = (*prevLocalPListArray)[i];
    PListType pListLength = (*prevLocalPListArray)[i]->size();

    PListType earlyApproximation = ceil(pListLength/256);

    for (PListType k = 0; k < pListLength; k++)
    {
        //If pattern is past end of string stream then stop counting this pattern
        if ((*pList)[k] < file->fileStringSize)
        {
            uint8_t indexer = ((uint8_t)file->fileString[(*pList)[k]]);

            if(newPList[indexer] != NULL) //Problem if statement!!!!!!!!!!!!!!!!!!!!!
            {
                newPList[indexer]->push_back(++(*pList)[k]);
            }
            else
            {
                newPList[indexer] = new vector<PListType>(1, ++(*pList)[k]);
                newPList[indexer]->reserve(earlyApproximation);
            }
        }
    }

    //Deallocate or stuff patterns in global list
    for (int z = 0; z < newPList.size(); z++)
    {
        if(newPList[z] != NULL)
        {
            if (newPList[z]->size() >= minOccurrence)
            {
                globalLocalPListArray->push_back(newPList[z]);
            }
            else
            {
                delete newPList[z];
            }
        }
    }
    delete (*prevLocalPListArray)[i];
}