add back priority

paddle/framework/op_registry_test.cc

@@ -376,16 +376,16 @@ TEST(OperatorRegistrar, OpWithMultiKernel) {
   paddle::framework::UseCPU();
   op->Run(scope, cpu_place);
 
-  EXPECT_EQ(op_test_value, -20);
+  EXPECT_EQ(op_test_value, -9);
 
   // add cuda kernels
   paddle::framework::UseCUDA();
   op->Run(scope, cuda_place);
 
-  EXPECT_EQ(op_test_value, -30);
+  EXPECT_EQ(op_test_value, -10);
 
   // use cudnn kernel
   paddle::framework::UseCUDNN();
   op->Run(scope, cuda_place);
-  EXPECT_EQ(op_test_value, -40);
+  EXPECT_EQ(op_test_value, -20);
 }

paddle/framework/operator.cc

@@ -474,6 +474,20 @@ void OperatorWithKernel::Run(const Scope& scope,
   ExecutionContext ctx(*this, scope, *dev_ctx);
   auto expected_kernel_key = this->GetExpectedKernelType(ctx);
 
+  OpKernelMap& kernels = kernels_iter->second;
+
+  for (auto& candidate : kKernelPriority) {
+    auto candidate_key =
+        OpKernelType(expected_kernel_key.data_type_, std::get<0>(candidate),
+                     expected_kernel_key.data_layout_, std::get<1>(candidate));
+
+    if ((candidate_key == expected_kernel_key) ||
+        (kernels.count(candidate_key))) {
+      expected_kernel_key = candidate_key;
+      break;
+    }
+  }
+
   Scope& new_scope = scope.NewScope();
 
   for (auto& var_name_item : this->Inputs()) {
@@ -504,7 +518,6 @@ void OperatorWithKernel::Run(const Scope& scope,
     }
   }
 
-  OpKernelMap& kernels = kernels_iter->second;
   auto kernel_iter = kernels.find(expected_kernel_key);
 
   kernel_iter->second->Compute(ExecutionContext(*this, new_scope, *dev_ctx));