[ENH] Speed up nanguardmode by not checking *int* dtype

theano/compile/nanguardmode.py

@@ -106,6 +106,8 @@ def contains_nan(arr, node=None, var=None):
     """
     if not _is_numeric_value(arr, var):
         return False
+    elif "int" in getattr(arr, 'dtype', ''):
+        return False
     elif pygpu_available and isinstance(arr, GpuArray):
         return np.isnan(f_gpua_min(arr.reshape(arr.size)))
 
@@ -139,6 +141,8 @@ def contains_inf(arr, node=None, var=None):
     """
     if not _is_numeric_value(arr, var):
         return False
+    elif "int" in getattr(arr, 'dtype', ''):
+        return False
     elif pygpu_available and isinstance(arr, GpuArray):
         return (np.isinf(f_gpua_min(arr.reshape(arr.size))) or
                 np.isinf(f_gpua_max(arr.reshape(arr.size))))

theano/compile/tests/test_nanguardmode.py

@@ -69,3 +69,14 @@ def test_NanGuardMode():
         assert_raises(AssertionError, fun, biga)  # big values
     finally:
         _logger.propagate = True
+
+    # Test with uint, we should not crash
+    x = T.matrix(dtype='uint8')
+    w = theano.shared(np.random.randn(5, 7).astype(theano.config.floatX))
+    y = T.dot(x, w)
+    a = (np.random.randn(3, 5).astype(theano.config.floatX)*10).astype('uint8')
+    fun = theano.function(
+        [x], y,
+        mode=NanGuardMode(nan_is_error=True, inf_is_error=True)
+    )
+    fun(a)  # normal values