select_item.py 文件源码

def backward_gpu(self, inputs, grad_outputs):
        x, t = inputs
        gloss = grad_outputs[0]
        gx = cuda.cupy.zeros_like(x)
        gx = cuda.elementwise(
            'S t, T gloss',
            'raw T gx',
            'int ind[] = {i, t}; gx[ind] = gloss;',
            'getitem_bwd'
        )(t, gloss, gx)
        return gx, None