Code clean up

theano/scan_module/scan_opt.py

@@ -1516,13 +1516,6 @@ class ScanSaveMem(gof.Optimizer):
                         node_ins]
             node_ins = pre_constant_merge(node_ins)
             # 3.6 Compose the new scan
-            # I need to make sure I'm not reapplying the same optimization
-            # twice since bad things usually happen if I do that
-            # TODO: why not check if save mem was done on any of merged nodes?
-            #       That way, if none of them had save mem applied, it would
-            #       be applied later.
-            info['_scan_savemem_visited'] = True
-
             # TODO: currently we don't support scan with 0 step. So
             # don't create one.
             if theano.tensor.extract_constant(node_ins[0]) == 0:
@@ -1627,7 +1620,6 @@ class ScanSaveMem(gof.Optimizer):
         nodelist = [x for x in fgraph.toposort() if isinstance(x.op,
                                                                scan_op.Scan)]
         for node in nodelist:
-            if not hasattr(node.op, '_scan_savemem_visited'):
             self.process_node(fgraph, node)
 
 
@@ -2264,6 +2256,7 @@ optdb.register('scan_eqopt1', scan_eqopt1, .05, 'fast_run', 'scan')
 # We run before blas opt at 1.7 and specialize 2.0
 # but after stabilize at 1.5. Should we put it before stabilize?
 optdb.register('scan_eqopt2', scan_eqopt2, 1.6, 'fast_run', 'scan')
+# ScanSaveMem should execute only once per node.
 optdb.register('scanOp_save_mem', ScanSaveMem(), 1.61, 'fast_run', 'scan')
 optdb.register('scanOp_make_inplace',
                ScanInplaceOptimizer(typeInfer=None,