(i) Some bugs in autograd.py and (ii) test_operation.py needs updates about singa HOT 6 CLOSED

class Reshape(Operation):

    def __init__(self,shape):
        super(Reshape, self).__init__()
        if isinstance(shape, tensor.Tensor):
            self.shape = np.asarray(tensor.to_numpy(shape).astype(np.int32)).tolist()
        else:
            self.shape = list(shape)

    def forward(self, x):
        _shape = x.shape()
        shape = self.shape
        # handle the shape with 0
        shape = [_shape[i] if i < len(_shape) and shape[i] == 0 else shape[i] for i in range(len(shape))]
        # handle the shape with -1
        hidden_shape = int(np.prod(_shape) // np.abs(np.prod(shape)))
        self.cache=[s if s != -1 else hidden_shape for s in shape]
        return singa.Reshape(x, self.cache)

    def backward(self, dy):
        return singa.Reshape(dy, self.cache)

class Reshape(Operation):
    def __init__(self,shape):
        super(Reshape, self).__init__()
        if isinstance(shape, tensor.Tensor):
            self.shape = np.asarray(tensor.to_numpy(shape).astype(np.int32)).tolist()
        else:
            self.shape = list(shape)

    def forward(self, x):
        self._shape = x.shape()
        shape = self.shape
        # handle the shape with 0
        shape = [self._shape[i] if i < len(self._shape) and shape[i] == 0 else shape[i] for i in range(len(shape))]
        # handle the shape with -1
        hidden_shape = int(np.prod(self._shape) // np.abs(np.prod(shape)))
        self.cache=[s if s != -1 else hidden_shape for s in shape]

        return singa.Reshape(x, self.cache)

    def backward(self, dy):
        return singa.Reshape(dy, self._shape)