Function cpu_allocMatrix

quest/src/cpu/cpu_config.cpp:325–345

qcomp** cpu_allocMatrix(qindex dim) {

    // NOTE:
    // this function creates a matrix where rows are not necessarily
    // contiguous in memory, which can incur gratuitous caching penalties
    // when accessed in hot loops. As such, we do not use this function
    // to allocate memory for CompMatr (instead, cpu_allocAndInitMatrixWrapper()),
    // but instead use it for the individual Kraus matrices of a KrausMap,
    // which are each quadratically smaller than the important superoperator.

    // allocate outer array
    qcomp** rows = (qcomp**) malloc(dim * sizeof *rows); // nullptr if failed

    // if that did not fail, allocate each inner array
    if (rows != nullptr)
        for (qindex r=0; r<dim; r++)
            rows[r] = cpu_allocArray(dim); // nullptr if failed

    // caller will validate whether mallocs were successful
    return rows;
}


void cpu_deallocMatrix(qcomp** matrix, qindex dim) {