opt.py 文件源码

def local_reshape_chain(op):
    @gof.local_optimizer([op])
    def f(node):
        """
        Reshape(Reshape(shape1),shape2) -> Reshape(shape2)

        """
        if not opt.check_chain(node, op, op):
            return False

        # TODO: this can permit a failing program to run by eliminating
        #       the lower reshape
        rval = node.op(node.inputs[0].owner.inputs[0], node.inputs[1])
        # It might happen that the desired output of this node has a
        # broadcastable pattern that does not match that of 'rval'. This is
        # when originally, we were able to figure out that one of the
        # dimensions of the reshape is one, but some other transformation
        # replaced the shape by one for which this cannot be guessed.
        # We should try to figure out why we lost the information about this
        # constant value... but in the meantime, better not apply this
        # optimization.
        if rval.broadcastable == node.outputs[0].broadcastable:
            return [rval]
        else:
            return False

    return f