Fixed test when cast_policy == numpy+floatX and floatX == float64

theano/sandbox/cuda/tests/test_opt.py

@@ -5,7 +5,7 @@ import numpy
 from nose.plugins.skip import SkipTest
 
 from theano.compile.pfunc import pfunc
-from theano import tensor
+from theano import config, tensor
 import theano
 
 import theano.sandbox.cuda as cuda
@@ -35,6 +35,12 @@ def test_no_shared_var_graph():
     assert numpy.any(isinstance(x.op,cuda.HostFromGpu) for x in l)
 
 def test_int_pow():
+    # This is to ensure that '4' does not upcast to float64.
+    if config.cast_policy == 'numpy+floatX':
+        floatX_backup = config.floatX
+        config.floatX = 'float32'
+
+    try:
         a = CudaNdarrayType([False])()
 
         f = theano.function([a], (a*4).sum(), mode=mode_with_gpu)
@@ -48,6 +54,10 @@ def test_int_pow():
 
         #theano.printing.debugprint(f)
 
+    finally:
+        if config.cast_policy == 'numpy+floatX':
+            config.floatX = floatX_backup
+
 def test_gpualloc():
     '''
     This tests tries to catch the scenario when, due to infer_shape,