correct computation equation

PaddlePaddle · Feb 28, 2024 · 62d9e51 · 62d9e51
1 parent 3df912d
commit 62d9e51
Showing 1 changed file with 5 additions and 3 deletions.
diff --git a/paddle/fluid/prim/api/composite_backward/composite_double_backward_api.h b/paddle/fluid/prim/api/composite_backward/composite_double_backward_api.h
@@ -441,13 +441,15 @@ void silu_double_grad(const Tensor& x,
                       Tensor* grad_x,
                       Tensor* grad_out_grad) {
   auto sigmoid = 1 / (1 + exp<T>(-x));
-  auto ddx_mul_tt = grad_x_grad * (x - out + 1);
+  auto tmp = 1 + x - out;
+  auto ddx_mul_sigmoid = grad_x_grad * sigmoid;
   if (grad_out_grad) {
-    set_output<T>(ddx_mul_tt * sigmoid, grad_out_grad);
+    set_output<T>(ddx_mul_sigmoid * tmp, grad_out_grad);
   }
   if (grad_x) {
     auto sigmoid_g = sigmoid * (1 - sigmoid);
-    set_output<T>(ddx_mul_tt * sigmoid_g, grad_x);
+    set_output<T>(ddx_mul_sigmoid * out_grad * (1 - sigmoid) * (tmp - out + 1),
+                  grad_x);
   }
 }