Added try statement to switch sink optimizations not to raise constant checking errors

theano/tensor/opt.py

@@ -1194,16 +1194,22 @@ def local_mul_switch_sink(node):
     for idx , i in enumerate(node.inputs):
         if i.owner and i.owner.op == T.switch:
             switch = i.owner
+            try:
                 if get_constant_value(switch.inputs[1]) == 0.:
                     listmul = node.inputs[:idx] + node.inputs[idx+1:]
                     fct = [T.switch(switch.inputs[0],0,T.mul(*(listmul + [switch.inputs[2]])))]
                     fct[0].values_eq_approx = fct[0].type.values_eq_approx_remove_nan
                     return fct
+            except TypeError:
+               pass 
+            try:
                 if get_constant_value(switch.inputs[2]) == 0.:
                     listmul = node.inputs[:idx] + node.inputs[idx+1:]
                     fct = [T.switch(switch.inputs[0],T.mul(*(listmul + [switch.inputs[1]])),0)]
                     fct[0].values_eq_approx = fct[0].type.values_eq_approx_remove_nan
                     return fct
+            except TypeError:
+                pass
     return False
 
 @register_canonicalize
@@ -1224,14 +1230,20 @@ def local_div_switch_sink(node):
     op = node.op
     if node.inputs[0].owner and node.inputs[0].owner.op == T.switch:
         switch = node.inputs[0].owner
+        try:
             if get_constant_value(switch.inputs[1]) == 0.:
                 fct = [T.switch(switch.inputs[0],0,op(switch.inputs[2],node.inputs[1]))]
                 fct[0].values_eq_approx = fct[0].type.values_eq_approx_remove_nan
                 return fct
+        except TypeError:
+            pass
+        try:
             if get_constant_value(switch.inputs[2]) == 0.:
                 fct = [T.switch(switch.inputs[0],op(switch.inputs[1],node.inputs[1]),0)]
                 fct[0].values_eq_approx = fct[0].type.values_eq_approx_remove_nan
                 return fct
+        except TypeError:
+            pass
     return False