// result = a + alpha * b
public static Array <Real> Add(this Array <Real> a, Array <Real> b, Real alpha = 1, Array <Real> result = null)
{
return(Array_.ElementwiseOp(a, b, result,
(n, x, offsetx, incx, y, offsety, incy, z, offsetz, incz) =>
{
if (alpha == 1 && incx == 1 && incy == 1 && incz == 1)
{
Blas.vadd(n, x, offsetx, y, offsety, z, offsetz);
}
else if (alpha == -1 && incx == 1 && incy == 1 && incz == 1)
{
Blas.vsub(n, x, offsetx, y, offsety, z, offsetz);
}
else if (z == x)
{
Blas.axpy(n, alpha, y, offsety, incy, x, offsetx, incx);
}
else if (z == y && alpha == 1)
{
Blas.axpy(n, alpha, x, offsetx, incx, y, offsety, incy);
}
// TODO: else if (incx == 0) => broadcast x ??
// TODO: else if (incy == 0) => broadcast y ??
else
{
for (int i = 0; i < n; i++) // TODO: Blas.copy y => x, Blas.axpy(1, x, y)
{
z[offsetz] = x[offsetx] + alpha * y[offsety];
offsetx += incx;
offsety += incy;
offsetz += incz;
}
} // See also: mkl_?omatadd => C := alpha*op(A) + beta*op(B)
}));
}
public void CompareElementWisePerformance()
{
Trace.Listeners.Add(new ConsoleTraceListener());
Func <float, float, float> f = (x, y) => x + y;
var clock = new Stopwatch();
#if DEBUG
Trace.WriteLine($"Testing on DEBUG");
#else
Trace.WriteLine($"Testing on RELEASE");
#endif
Trace.WriteLine($"Testing on {Blas.NThreads} threads");
for (int i = 0; i < 300; ++i)
{
int n = i + 1;
var a = NN.Random.Uniform(-1f, 1f, n, n);
var b = NN.Random.Uniform(-1f, 1f, n, n);
var r = NN.Zeros(n, n);
var size = a.Size;
// estimating loop count for this size
NN.MIN_SIZE_FOR_PARELLELISM = size * 2;
var loopCount = 0;
clock.Restart();
while (clock.ElapsedMilliseconds < 1000)
{
NN.Apply(a, b, f, result: r);
++loopCount;
}
Trace.WriteLine($"doing {loopCount} loops for size {size}");
// profiling Normal
clock.Restart();
for (int _ = 0; _ < loopCount; _++)
{
NN.Apply(a, b, f, result: r);
}
var time = clock.ElapsedMilliseconds;
var avg = (double)time / loopCount;
// profiling Parrellized
NN.MIN_SIZE_FOR_PARELLELISM = 0;
clock.Restart();
for (int _ = 0; _ < loopCount; _++)
{
NN.Apply(a, b, f, result: r);
}
var timePar = clock.ElapsedMilliseconds;
var avgPar = (double)timePar / loopCount;
clock.Restart();
for (int _ = 0; _ < loopCount; _++)
{
a.Add(b, result: r);
}
var timeAdd = clock.ElapsedMilliseconds;
var avgAdd = (double)timeAdd / loopCount;
clock.Restart();
for (int _ = 0; _ < loopCount; _++)
{
Blas.vadd(size, a.Values, 0, b.Values, 0, r.Values, 0);
}
var timeBlas = clock.ElapsedMilliseconds;
var avgBlas = (double)timeBlas / loopCount;
var message = $"On size {size}, avg time: {avg:F4}ms \t with parallelism {avgPar:F4}ms \t with Add {avgAdd:F4}ms \t with Blas {avgBlas:F4}ms.";
Trace.WriteLine(message);
}
throw new Exception("see output for profiler results");
}