Merge pull request #4040 from caglar/fix_fload_multi_bug

theano/sandbox/multinomial.py

@@ -53,7 +53,8 @@ class MultinomialFromUniform(Op):
     def grad(self, ins, outgrads):
         pvals, unis, n = ins
         (gz,) = outgrads
-        return [T.zeros_like(x) for x in ins]
+        return [T.zeros_like(x, dtype=theano.config.floatX) if x.dtype in
+                T.discrete_dtypes else T.zeros_like(x) for x in ins]
 
     def c_code_cache_version(self):
         return (8,)