fix leaky_relu op when alpha is zero, test=develop (#19833)

paddle/fluid/operators/activation_op.h

@@ -1073,8 +1073,8 @@ struct LeakyReluGradFunctor : public BaseActivationFunctor<T> {
             typename dX>
   void operator()(Device d, X x, Out out, dOut dout, dX dx) const {
     auto temp1 =
-        static_cast<T>(alpha) * (out < static_cast<T>(0)).template cast<T>();
-    auto temp2 = (out >= static_cast<T>(0)).template cast<T>();
+        static_cast<T>(alpha) * (out <= static_cast<T>(0)).template cast<T>();
+    auto temp2 = (out > static_cast<T>(0)).template cast<T>();
     dx.device(d) = dout * (temp1 + temp2).template cast<T>();
   }
 
@@ -1418,11 +1418,11 @@ struct LeakyReluGradGradFunctor : public BaseActivationFunctor<T> {
       auto ddx = framework::EigenVector<T>::Flatten(detail::Ref(ddX));
       auto out = framework::EigenVector<T>::Flatten(detail::Ref(Out));
       auto ddout = framework::EigenVector<T>::Flatten(detail::Ref(ddOut));
-      ddout.device(*d) =
-          ddx *
-          ((out >= static_cast<T>(0)).template cast<T>() +
-           static_cast<T>(alpha) * (out < static_cast<T>(0)).template cast<T>())
-              .template cast<T>();
+      ddout.device(*d) = ddx *
+                         ((out > static_cast<T>(0)).template cast<T>() +
+                          static_cast<T>(alpha) *
+                              (out <= static_cast<T>(0)).template cast<T>())
+                             .template cast<T>();
     }
   }
   static constexpr ActBwdOpFwdDeps FwdDeps() { return kDepOut; }

paddle/fluid/operators/test_leaky_relu_grad_grad_functor.cc

@@ -22,5 +22,10 @@ TEST(leaky_relu_grad_grad, test_cpu) {
       TestLeakyReluGradGradMain<float>({32, 64}, platform::CPUPlace(), 0.02));
 }
 
+TEST(leaky_relu_grad_grad, test_cpu_zero_alpha) {
+  ASSERT_TRUE(
+      TestLeakyReluGradGradMain<float>({32, 64}, platform::CPUPlace(), 0.0));
+}
+
 }  // namespace operators
 }  // namespace paddle

paddle/fluid/operators/test_leaky_relu_grad_grad_functor.cu

@@ -22,5 +22,10 @@ TEST(leaky_relu_grad_grad, test_gpu) {
       TestLeakyReluGradGradMain<float>({32, 64}, platform::CUDAPlace(0), 0.15));
 }
 
+TEST(leaky_relu_grad_grad, test_gpu_zero_alpha) {
+  ASSERT_TRUE(
+      TestLeakyReluGradGradMain<float>({32, 64}, platform::CUDAPlace(0), 0.0));
+}
+
 }  // namespace operators
 }  // namespace paddle

paddle/fluid/operators/test_leaky_relu_grad_grad_functor.h

@@ -46,7 +46,7 @@ struct LeakyReluGradGradEachElementFunctor {
       : ddx_(ddx), out_(out), alpha_(alpha), ddout_(ddout) {}
 
   HOSTDEVICE void operator()(int idx) {
-    if (out_[idx] >= 0) {
+    if (out_[idx] > 0) {
       ddout_[idx] = ddx_[idx];
     } else {
       ddout_[idx] = ddx_[idx] * alpha_;