add REGISTER of as_real (#51313)

paddle/fluid/framework/new_executor/interpreter/interpreter_util.cc

@@ -58,7 +58,6 @@ static std::set<std::string> OpsNeedSetOutputDtypeWhenRegisterPhiKernel = {
     "angle",
     "any_raw",
     "arg_sort",
-    "as_real",
     "atan2",
     "auc",
     "bincount",

paddle/phi/infermeta/unary.cc

@@ -273,6 +273,7 @@ void AsRealInferMeta(const MetaTensor& input, MetaTensor* output) {
   auto out_dims = phi::make_ddim(out_dims_v);
   output->set_dims(out_dims);
   output->share_lod(input);
+  output->set_dtype(dtype::ToReal(input.dtype()));
 }
 
 void AsComplexInferMeta(const MetaTensor& input, MetaTensor* output) {

paddle/phi/kernels/cpu/as_real_kernel.cc

@@ -23,4 +23,6 @@ using complex64 = ::phi::dtype::complex<float>;
 using complex128 = ::phi::dtype::complex<double>;
 
 PD_REGISTER_KERNEL(
-    as_real, CPU, ALL_LAYOUT, phi::AsRealKernel, complex64, complex128) {}
+    as_real, CPU, ALL_LAYOUT, phi::AsRealKernel, complex64, complex128) {
+  kernel->OutputAt(0).SetDataType(paddle::experimental::DataType::UNDEFINED);
+}

paddle/phi/kernels/gpu/as_real_kernel.cu

@@ -23,4 +23,6 @@ using complex64 = ::phi::dtype::complex<float>;
 using complex128 = ::phi::dtype::complex<double>;
 
 PD_REGISTER_KERNEL(
-    as_real, GPU, ALL_LAYOUT, phi::AsRealKernel, complex64, complex128) {}
+    as_real, GPU, ALL_LAYOUT, phi::AsRealKernel, complex64, complex128) {
+  kernel->OutputAt(0).SetDataType(paddle::experimental::DataType::UNDEFINED);
+}