Function ggml_compute_backward

ggml.c:15403–16206

}

static void ggml_compute_backward(struct ggml_context * ctx, struct ggml_tensor * tensor, struct ggml_hash_set zero_table) {
    struct ggml_tensor * src0 = tensor->src[0];
    struct ggml_tensor * src1 = tensor->src[1];

    switch (tensor->op) {
        case GGML_OP_DUP:
            {
                if (src0->grad) {
                    src0->grad = ggml_add_or_set(ctx, src0->grad, tensor->grad, zero_table);
                }
            } break;
        case GGML_OP_ADD:
            {
                if (src0->grad) {
                    src0->grad = ggml_add_or_set(ctx, src0->grad, tensor->grad, zero_table);
                }
                if (src1->grad) {
                    src1->grad = ggml_add_or_set(ctx, src1->grad, tensor->grad, zero_table);
                }
            } break;
        case GGML_OP_ADD1:
            {
                if (src0->grad) {
                    src0->grad = ggml_add_or_set(ctx, src0->grad, tensor->grad, zero_table);
                }
                if (src1->grad) {
                    src1->grad = ggml_add_or_set(ctx,
                        src1->grad,
                        ggml_mean(ctx, tensor->grad), // TODO: should probably be sum instead of mean
                        zero_table);
                }
            } break;
        case GGML_OP_ACC:
            {
                if (src0->grad) {
                    src0->grad = ggml_add_or_set(ctx, src0->grad, tensor->grad, zero_table);
                }
                if (src1->grad) {
                    const size_t nb1     = ((int32_t *) tensor->op_params)[0];
                    const size_t nb2     = ((int32_t *) tensor->op_params)[1];
                    const size_t nb3     = ((int32_t *) tensor->op_params)[2];
                    const size_t offset  = ((int32_t *) tensor->op_params)[3];

                    struct ggml_tensor * tensor_grad_view = ggml_view_4d(ctx,
                        tensor->grad,
                        src1->grad->ne[0],
                        src1->grad->ne[1],
                        src1->grad->ne[2],
                        src1->grad->ne[3],
                        nb1, nb2, nb3, offset);

                    src1->grad =
                        ggml_add_or_set(ctx,
                            src1->grad,
                            ggml_reshape(ctx,
                                ggml_cont(ctx, tensor_grad_view),
                                src1->grad),
                            zero_table);