BLAS-based matrix multiplication in node.js (for Julia micro benchmark)

blas_randmatmul.js

    // Requirements:
    //      1) npm install ffi
    //      2) npm install ref
    //      3) dynamically loadable libblas must be available aleady.
    var ffi = require('ffi');
    var ref = require('ref');
    var doublePtr = ref.refType(ref.types.double);
    var blas = new ffi.Library('libblas', {
        'cblas_dgemm': ['void', [
            'int', 'int', 'int', 'int', 'int', 'int',
            'double', doublePtr, 'int', doublePtr,
            'int', 'double', doublePtr, 'int'
        ]]
    });

    var CblasRowMajor = 101;
    var CblasNoTrans = 111;
    var sizeofDouble = 8;

    function blas_randmat(m, n) {
        var M = new Buffer(m * n * sizeofDouble);

        var i, j, offset = 0;
        for (i = 0; i < m; ++i) {
            for (j = 0; j < n; ++j) {
                M.writeDoubleLE(Math.random(), offset);
                offset += sizeofDouble;
            }
        }

        return M;
    }

    function blas_matmul(A, B, m, l, n) {
        var C = new Buffer(m * n * sizeofDouble);
        blas.cblas_dgemm(
                CblasRowMajor,
                CblasNoTrans,
                CblasNoTrans,
                m, n, l,
                1.0, A,
                l, B, n,
                0.0,
                C, n);
        return C;
    }
    
    function blas_randmatmul(n) {
        var A = blas_randmat(n, n);
        var B = blas_randmat(n, n);

        return blas_matmul(A, B, n, n, n);
    }
    
    // How to sanity-test the result -
    //  C = blas_randmatmul(1000);
    //  assert(0 < C.readDoubleLE(0));