Function assertQuregFitsInCpuMem

quest/src/core/validation.cpp:1620–1657

}

void assertQuregFitsInCpuMem(int numQubits, int isDensMatr, int isDistrib, QuESTEnv env, const char* caller) {

    // attempt to fetch RAM, and simply return if we fail; if we unknowingly
    // didn't have enough RAM, then alloc validation will trigger later
    size_t memPerNode = 0;
    try {
        memPerNode = mem_tryGetLocalRamCapacityInBytes();
    } catch(mem::COULD_NOT_QUERY_RAM e) {
        return;
    }

    // check whether qureg (considering if distributed) fits between node memory(s).
    // note this sets numQuregNodes=1 only when distribution is impossible/switched-off,
    // but not when it would later be automatically disabled. that's fine; the auto-deployer
    // will never disable distribution if local RAM can't store the qureg, so we don't need to
    // validate the auto-deployed-to-non-distributed scenario. we only need to ensure that
    // auto-deploying-to-distribution is permitted by memory capacity.
    int numQuregNodes = (isDistrib == 0 || ! env.isDistributed)? 1 : env.numNodes;
    bool quregFitsInMem = mem_canQuregFitInMemory(numQubits, isDensMatr, numQuregNodes, memPerNode);

    // make error message specific to whether qureg is local or distributed
    string msg = (numQuregNodes == 1)?
        report::NEW_QUREG_CANNOT_FIT_INTO_NON_DISTRIB_CPU_MEM :
        report::NEW_QUREG_CANNOT_FIT_INTO_POTENTIALLY_DISTRIB_CPU_MEM;

    tokenSubs vars = {
        {"${IS_DENS}",     isDensMatr},
        {"${NUM_QUBITS}",  numQubits},
        {"${QCOMP_BYTES}", sizeof(qcomp)},
        {"${EXP_BASE}",    (isDensMatr)? 4 : 2},
        {"${RAM_SIZE}",    memPerNode}};

    if (numQuregNodes > 1)
        vars["${NUM_NODES}"] = numQuregNodes;

    // require expensive node consensus in case of heterogeneous RAMs
    assertAllNodesAgreeThat(quregFitsInMem, msg, vars, caller);
}

void assertQuregFitsInGpuMem(int numQubits, int isDensMatr, int isDistrib, int isGpuAccel, QuESTEnv env, const char* caller) {