Multithreaded sparse matrix multiplication in Matlab

Question

I am performing several matrix multiplications of an NxN sparse (~1-2%) matrix, let\'s call it B, with an NxM dense matrix, let\'s call it A (where M < N). N is large, as

Answer 1

I ended up writing my own mex file with OpenMP for multithreading. Code as follows. Don't forget to use -largeArrayDims and /openmp (or -fopenmp) flags when compiling.

#include 
#include "mex.h"
#include "matrix.h"

#define ll long long

void omp_smm(double* A, double*B, double* C, ll m, ll p, ll n, ll* irs, ll* jcs)
{
    for (ll j=0; j