Use the new clone_float32 in GpuElemwise and remove the remaining hacks.

theano/gpuarray/elemwise.py

@@ -49,6 +49,11 @@ class GpuElemwise(HideC, Elemwise):
     nout = property(lambda self: self.scalar_op.nout)
     _f16_ok = True
 
+    def __init__(self, scalar_op, *args, **kwargs):
+        if isinstance(scalar_op, Composite):
+            scalar_op = scalar_op.clone_float32()
+        Elemwise.__init__(self, scalar_op, *args, **kwargs)
+
     def __str__(self):
         if self.name is not None:
             return self.name
@@ -86,15 +91,7 @@ class GpuElemwise(HideC, Elemwise):
         except MethodNotDefined:
             pass
 
-        if fake_node.op != self.scalar_op:
-            # If the new op is different due to type changes, we make a new
-            # op for it.
-            elem = GpuElemwise(fake_node.op, self.inplace_pattern, self.name,
-                               self.nfunc_spec, self.openmp)
-        else:
-            elem = self
-
-        node = Apply(elem, inputs, outputs)
+        node = Apply(self, inputs, outputs)
         return node
 
     def get_params(self, node):
@@ -119,8 +116,7 @@ class GpuElemwise(HideC, Elemwise):
                                   inps, outs,
                                   dict(fail='return;'))
 
-        # Some ops like cast will reintroduce float16 in the internal graph.
-        kop = kop.replace('npy_float16', 'ga_float')
+        assert 'npy_float16' not in kop
 
         support_code = ""
         try: