Minor ngraph fix (#16270)

* take care edge cases test=develop

* use pragma test=develop

paddle/fluid/operators/ngraph/ngraph_engine.cc

@@ -92,12 +92,10 @@ static std::vector<std::vector<int>> NgraphOpIntervals(
 
   int size = ops->size();
   int left = 0;
-  while (left < size && ops->at(left)->Type() != framework::kFeedOpType) {
+  while (left < size && ops->at(left)->Type() != framework::kFeedOpType &&
+         ops->at(left)->Type() != framework::kFetchOpType) {
     ++left;
   }
-  if (left == size) {
-    return intervals;
-  }
 
   while (left < size && ops->at(left)->Type() == framework::kFeedOpType) {
     for (auto& var_name_item : ops->at(left)->Outputs()) {
@@ -112,10 +110,6 @@ static std::vector<std::vector<int>> NgraphOpIntervals(
   while (right < size && ops->at(right)->Type() != framework::kFetchOpType) {
     ++right;
   }
-  if (right == size) {
-    return intervals;
-  }
-  if (left >= right) return intervals;
 
   int index = right;
   while (index < size && ops->at(index)->Type() == framework::kFetchOpType) {
@@ -127,6 +121,10 @@ static std::vector<std::vector<int>> NgraphOpIntervals(
     ++index;
   }
 
+  if (left == size || ops->at(left)->Type() == framework::kFetchOpType) {
+    left = 0;
+  }
+
   // (left, right - 1) represents indices between feed and fetch
   int pivot = left;
   while (pivot < right) {
@@ -234,6 +232,7 @@ NgraphEngine::NgraphEngine(const framework::Scope& scope,
 }
 
 void NgraphEngine::Prepare(const std::vector<int>& interval) {
+  bool has_fetch = false, is_full = false;
   for (auto& var : p_bdesc->AllVars()) {
     if (!(var->GetType() == framework::proto::VarType::SELECTED_ROWS ||
           var->GetType() == framework::proto::VarType::LOD_TENSOR ||
@@ -264,6 +263,9 @@ void NgraphEngine::Prepare(const std::vector<int>& interval) {
   std::vector<paddle::framework::OpDesc*> ops_desc;
   for (auto op_desc : p_bdesc->AllOps()) {
     ops_desc.emplace_back(op_desc);
+    if (op_desc->Type() == framework::kFetchOpType) {
+      has_fetch = true;
+    }
   }
 
   for (auto op_desc : ops_desc) {
@@ -276,11 +278,11 @@ void NgraphEngine::Prepare(const std::vector<int>& interval) {
   if (interval[0] > 0 &&
       ops_desc.at(interval[0] - 1)->Type() == framework::kFeedOpType &&
       interval[1] < static_cast<int>(ops_desc.size()) &&
-      ops_desc.at(interval.at(1))->Type() == framework::kFetchOpType) {
-    this->op_state_ = OpState::FULL;
+      ops_desc.at(interval[1])->Type() == framework::kFetchOpType) {
+    is_full = true;
   }
 
-  if (this->op_state_ == OpState::FULL) {
+  if (is_full) {
     this->op_state_ = this->is_test_ ? OpState::FULL_TEST : OpState::FULL_TRAIN;
   } else {
     this->op_state_ =
@@ -293,7 +295,8 @@ void NgraphEngine::Prepare(const std::vector<int>& interval) {
         framework::OpRegistry::CreateOp(*(ops_desc[idx])));
     ++idx;
   }
-  while (ops_desc.at(idx)->Type() != framework::kFetchOpType) {
+  while (idx < static_cast<int>(ops_desc.size()) &&
+         ops_desc.at(idx)->Type() != framework::kFetchOpType) {
     auto op_desc = ops_desc.at(idx);
     for (auto& var_name_item : op_desc->Inputs()) {
       for (auto& var_name : var_name_item.second) {
@@ -303,6 +306,10 @@ void NgraphEngine::Prepare(const std::vector<int>& interval) {
     ++idx;
   }
 
+  if (!has_fetch) {
+    op_state_ = OpState::UNKNOWN;
+  }
+
   BuildNgIO(ops_desc, interval);
 }
 
@@ -378,6 +385,7 @@ void NgraphEngine::BuildNgIO(const std::vector<framework::OpDesc*>& ops_desc,
       }
     }
   }
+
   for (size_t i = 0; i < var_in_.size(); ++i) {
     auto var_name = var_in_[i];
     if (persistables_.find(var_name) == persistables_.end()) {

paddle/fluid/operators/ngraph/ngraph_engine.h

@@ -12,8 +12,8 @@ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License. */
 
-#ifndef PADDLE_FLUID_OPERATORS_NGRAPH_NGRAPH_ENGINE_H_
-#define PADDLE_FLUID_OPERATORS_NGRAPH_NGRAPH_ENGINE_H_
+#pragma once
+
 #include <memory>
 #include <set>
 #include <string>
@@ -35,7 +35,6 @@ enum class OpState {                /* nGraph support state on ops          */
                      PARTIAL_TRAIN, /* Support partial ops for train        */
                      FULL_TEST,     /* Support full list of ops for test    */
                      PARTIAL_TEST,  /* Support partial list of ops for test */
-                     FULL,          /* All ops supported from feed to fetch */
                      UNKNOWN        /* Output all for debug purpose         */
 };
 
@@ -119,4 +118,3 @@ class NgraphEngine {
 
 }  // namespace operators
 }  // namespace paddle
-#endif  // PADDLE_FLUID_OPERATORS_NGRAPH_NGRAPH_ENGINE_H_