from theano import function, config, shared, sandbox

import theano.tensor as T

import numpy

import time

vlen = 10 * 30 * 768  # 10 x #cores x # threads per core

iters = 1000

rng = numpy.random.RandomState(22)

x = shared(numpy.asarray(rng.rand(vlen), config.floatX))

f = function([], T.exp(x))

print (f.maker.fgraph.toposort())

t0 = time.time()

for i in range(iters):

    r = f()

t1 = time.time()

print ('Looping %d times took' % iters, t1 - t0, 'seconds')

print ('Result is', r)

if numpy.any([isinstance(x.op, T.Elemwise) for x in f.maker.fgraph.toposort()]):

    print ('Used the cpu')

else:

    print ('Used the gpu')