diff --git a/mindspore/ccsrc/backend/optimizer/somas/somas.cc b/mindspore/ccsrc/backend/optimizer/somas/somas.cc
index 08921d7e16..cded3c47b6 100644
--- a/mindspore/ccsrc/backend/optimizer/somas/somas.cc
+++ b/mindspore/ccsrc/backend/optimizer/somas/somas.cc
@@ -122,6 +122,7 @@ void Somas::InitSomasStreamAndNode(const session::KernelGraph *graph) {
     MS_EXCEPTION_IF_NULL(node);
     node->scope_full_name_ = kernel->fullname_with_scope();
     nodes_list_.push_back(node);
+    stream->nodes_.push_back(node);
     auto key = kernel.get();
     nodes_map_[key] = node;
     node_index++;
@@ -565,220 +566,155 @@ void Somas::PreprocessingConflicts() {
   }
 }
 
-static bool LifetimeOverlap(lifetime_t lifetime1, lifetime_t lifetime2) {
-  size_t start1 = std::min(lifetime1.start_, lifetime1.end_);
-  size_t end1 = std::max(lifetime1.start_, lifetime1.end_);
-  size_t start2 = std::min(lifetime2.start_, lifetime2.end_);
-  size_t end2 = std::max(lifetime2.start_, lifetime2.end_);
-  return (std::max(end1, end2) - std::min(start1, start2) <= end2 - start2 + end1 - start1);
-}
-
-static bool Subset(std::set<SomasStreamPtr> streamSet1, std::set<SomasStreamPtr> streamSet2) {
-  for (auto stream : streamSet1) {
-    if (streamSet2.count(stream) == 0) {
-      return false;
-    }
+void Somas::ComputeConflictPairs() {
+  if (tensors_list_.empty()) {
+    MS_LOG(INFO) << "No Tensor for Conflict computing";
+    return;
   }
-  return true;
-}
 
-static void EraseSet(std::set<SomasStreamPtr> *streamSet, std::set<SomasStreamPtr> removeStreamsSet) {
-  for (auto stream : removeStreamsSet) {
-    streamSet->erase(stream);
+  MS_LOG(INFO) << "Start Preprocessing Conflicts";
+  PreprocessingConflicts();
+  MS_LOG(INFO) << "End Preprocessing Conflicts";
+
+  MS_LOG(INFO) << "Start Conflict Computing (Bitset Model)";
+  std::sort(nodes_list_.begin(), nodes_list_.end(), NodeSort);
+
+  // Loop to add edges within each stream (node order within stream)
+  for (const auto &stream : streams_list_) {
+    auto &nodes = stream->nodes_;
+    std::sort(nodes.begin(), nodes.end(), NodeSort);
+    for (size_t i = 1; i < nodes.size(); i++) {
+      const auto &previous_node = nodes[i - 1];
+      const auto &current_node = nodes[i];
+      current_node->ancestor_nodes_.insert(previous_node);
+    }
   }
-}
 
-static bool ValidSubset(std::set<SomasStreamPtr> destStreams, std::set<SomasStreamPtr> ancestorsAndSelf,
-                        SomasTensorPtr ancestorTensor, SomasTensorPtr tensor) {
-  MS_EXCEPTION_IF_NULL(ancestorTensor);
-  MS_EXCEPTION_IF_NULL(tensor);
-  for (auto stream : destStreams) {
-    if (ancestorsAndSelf.count(stream) == 0) {
-      return false;
-    }
-
-    if (stream != tensor->GetSourceStream()) {
-      MS_EXCEPTION_IF_NULL(tensor->GetSourceStream());
-      if (tensor->GetSourceStream()->ancestor_streams_group_.count(stream) == 0 &&
-          ancestorTensor->max_destination_id_[stream] >
-            tensor->GetSourceNode()->anc_stream_max_order_[stream->GetId()]) {
-        return false;
+  // Loop to add edges from end to beginning of next group
+  for (const auto &group : streams_groups_) {
+    for (size_t i = 1; i < group.size(); i++) {
+      int64_t previous_stream = group[i - 1];
+      int64_t current_stream = group[i];
+
+      auto it =
+        std::find_if(streams_list_.begin(), streams_list_.end(),
+                     [previous_stream](const SomasStreamPtr &stream) { return stream->GetId() == previous_stream; });
+      if (it == streams_list_.end()) {
+        continue;
       }
-    } else {
-      if (ancestorTensor->max_destination_id_[stream] >= tensor->lifetime_.start_) {
-        return false;
+      auto &last_node_in_prev_stream = (*it)->nodes_.back();
+
+      it = std::find_if(streams_list_.begin(), streams_list_.end(),
+                        [current_stream](const SomasStreamPtr &stream) { return stream->GetId() == current_stream; });
+      if (it == streams_list_.end()) {
+        continue;
       }
+      auto &first_node_in_cur_stream = (*it)->nodes_.front();
+
+      first_node_in_cur_stream->ancestor_nodes_.insert(last_node_in_prev_stream);
     }
   }
-  return true;
-}
 
-void Somas::ComputeConflictPairs() {
-  if (tensors_list_.empty()) {
-    MS_LOG(INFO) << "No Tensor for Conflict computing";
-    return;
+  // Loop to avoid tensors with empty destinations (add itself)
+  for (const auto &tensor : tensors_list_) {
+    if (tensor->destinations_.size() == 0) {
+      tensor->destinations_.insert(tensor->GetSourceNode());
+    }
   }
 
-  MS_LOG(INFO) << "Start Preprocessing Conflicts";
-  PreprocessingConflicts();
-  MS_LOG(INFO) << "End Preprocessing Conflicts";
+  MS_LOG(INFO) << "Start Bitset";
+  std::vector<DynamicBitSet> nodes_dependency;
 
-  MS_LOG(INFO) << "Start Array Initialization";
-  cannot_reuse_ =
-    std::make_shared<Array>(tensors_list_.back()->GetId() + 1,
-                            tensors_list_.back()->GetId() + 1);  // array size is (max_id + 1) x (max_id + 1)
-  MS_LOG(INFO) << "End Array Initialization";
+  size_t count = nodes_list_.back()->GetId() + 1;
+  for (size_t i = 0; i < count; i++) {
+    nodes_dependency.emplace_back(count);
+  }
+
+  MS_LOG(INFO) << "Start Path Computing";
+  // Loop to compute ancestor paths via bitset for time dependence
+  for (const auto &node : nodes_list_) {
+    for (const auto &ancestor : node->ancestor_nodes_) {
+      nodes_dependency[node->GetId()].SetBitTrue(ancestor->GetId());
+      Union(&nodes_dependency[node->GetId()], &nodes_dependency[ancestor->GetId()]);
+    }
+  }
+  MS_LOG(INFO) << "End Path Computing";
 
-  MS_LOG(INFO) << "Start Conflict Computing";
+  MS_LOG(INFO) << "Start Tensor Relation Computing";
+  count = tensors_list_.back()->GetId() + 1;
+  for (size_t i = 0; i < count; i++) {
+    tensor_relation.emplace_back(count);
+  }
 
-  size_t count_reuse = 0;
+  for (size_t i = 0; i < tensors_list_.size(); i++) {
+    for (size_t j = i + 1; j < tensors_list_.size(); j++) {
+      auto t0 = tensors_list_[i];
+      auto t1 = tensors_list_[j];
 
-  // Loop for ancestor stream groups reuse
-  for (auto stream : streams_list_) {
-    std::set<SomasStreamPtr> ancestors = stream->ancestor_streams_group_;
-
-    std::set<SomasStreamPtr> ancestors_and_self = ancestors;
-    ancestors_and_self.insert(stream);
-
-    for (auto ancestor_stream : ancestors) {
-      for (auto ancestor_tensor : ancestor_stream->tensors_) {
-        if (ancestor_tensor->GetAlignedSize() == 0) continue;
-        if (ancestor_tensor->IsLifelong()) continue;
-        if (ancestor_tensor->IsSemiLifelongEnd()) continue;
-        if (ancestor_tensor->IsRefOverlap()) continue;
-
-        if (!ancestor_tensor->IsBetweenStreams() || Subset(ancestor_tensor->destinationStreams_, ancestors)) {
-          for (auto tensor : stream->tensors_) {
-            if (tensor->IsGap()) continue;
-            if (tensor->GetAlignedSize() == 0) continue;
-            if (tensor->IsLifelong()) continue;
-            if (tensor->IsSemiLifelongStart()) continue;
-            if (tensor->IsRefOverlap()) continue;
-
-            (*cannot_reuse_)(ancestor_tensor->GetId(), tensor->GetId()) = 0;
-            (*cannot_reuse_)(tensor->GetId(), ancestor_tensor->GetId()) = 0;
-            count_reuse++;
-          }
+      if (t0 == t1 || t0->IsGap() || t1->IsGap() || t0->IsLifelong() || t1->IsLifelong() || t0->IsRefOverlap() ||
+          t1->IsRefOverlap() || t0->GetAlignedSize() == 0 || t1->GetAlignedSize() == 0) {
+        continue;
+      }
+
+      size_t t0_src_node = t0->GetSourceNode()->GetId();
+      size_t t1_src_node = t1->GetSourceNode()->GetId();
+      if (t0_src_node == t1_src_node) {
+        continue;
+      }
+
+      bool reuse = true;
+      bool all_dst_depend = false;
+      // check t0's all consumers is t1's source node's dependency or not
+      for (const auto &dst_node : t0->destinations_) {
+        if (nodes_dependency[t1_src_node].IsBitTrue(dst_node->GetId()) == false) {
+          // t0's consumer is not in t1's source node's dependency, not sure this consumer is done or not when t1
+          // produced
+          reuse = false;
+          all_dst_depend = false;
+          break;
+        } else if (t1_src_node == dst_node->GetId()) {
+          // t0 is t1's source node's input, can't reuse
+          reuse = false;
+          all_dst_depend = true;
+          break;
         } else {
-          for (auto tensor : stream->tensors_) {
-            if (Subset(ancestor_tensor->destinationStreams_, ancestors_and_self) &&
-                ancestor_tensor->max_destination_id_[tensor->GetSourceStream()] < tensor->lifetime_.start_) {
-              if (tensor->IsGap()) continue;
-              if (tensor->GetAlignedSize() == 0) continue;
-              if (tensor->IsLifelong()) continue;
-              if (tensor->IsSemiLifelongStart()) continue;
-              if (tensor->IsRefOverlap()) continue;
-
-              (*cannot_reuse_)(ancestor_tensor->GetId(), tensor->GetId()) = 0;
-              (*cannot_reuse_)(tensor->GetId(), ancestor_tensor->GetId()) = 0;
-              count_reuse++;
-            }
-          }
+          // t0's consumer is in t1's source node's dependency, this consumer is done when t1 produced
+          reuse = true;
+          all_dst_depend = true;
         }
       }
-    }
-  }
 
-  // Loop for ancestor streams (no groups)
-  for (auto stream : streams_list_) {
-    auto ancestors_no_groups = stream->ancestor_streams_;
-    EraseSet(&ancestors_no_groups, stream->ancestor_streams_group_);
-
-    for (auto ancestor_stream : ancestors_no_groups) {
-      for (auto ancestor_tensor : ancestor_stream->tensors_) {
-        if (ancestor_tensor->GetAlignedSize() == 0) continue;
-        if (ancestor_tensor->IsLifelong()) continue;
-        if (ancestor_tensor->IsSemiLifelongEnd()) continue;
-        if (ancestor_tensor->IsRefOverlap()) continue;
-
-        if (!ancestor_tensor->IsBetweenStreams()) {
-          for (auto tensor : stream->tensors_) {
-            if (tensor->IsGap()) continue;
-            if (tensor->GetAlignedSize() == 0) continue;
-            if (tensor->IsLifelong()) continue;
-            if (tensor->IsSemiLifelongStart()) continue;
-            if (tensor->IsRefOverlap()) continue;
-
-            size_t max_ancestor_order = tensor->GetSourceNode()->anc_stream_max_order_[ancestor_stream->GetId()];
-
-            if (ancestor_tensor->lifetime_.end_ <= max_ancestor_order) {
-              (*cannot_reuse_)(ancestor_tensor->GetId(), tensor->GetId()) = 0;
-              (*cannot_reuse_)(tensor->GetId(), ancestor_tensor->GetId()) = 0;
-              count_reuse++;
-            }
-          }
-        } else {  // ancestor tensor goes to another stream (might go to same stream also)
-          std::set<SomasStreamPtr> dest_streams = ancestor_tensor->destinationStreams_;
-          std::set<SomasStreamPtr> ancestors = stream->ancestor_streams_;
-
-          std::set<SomasStreamPtr> ancestors_and_self = ancestors;
-          ancestors_and_self.insert(stream);
-
-          for (auto tensor : stream->tensors_) {
-            if (tensor->IsGap()) continue;
-            if (tensor->GetAlignedSize() == 0) continue;
-            if (tensor->IsLifelong()) continue;
-            if (tensor->IsSemiLifelongStart()) continue;
-            if (tensor->IsRefOverlap()) continue;
-
-            if (ValidSubset(dest_streams, ancestors_and_self, ancestor_tensor, tensor)) {
-              (*cannot_reuse_)(ancestor_tensor->GetId(), tensor->GetId()) = 0;
-              (*cannot_reuse_)(tensor->GetId(), ancestor_tensor->GetId()) = 0;
-              count_reuse++;
-            }
+      if (all_dst_depend == false) {
+        // check t1's all consumers is t0's source node's dependency or not
+        reuse = true;
+        for (const auto &dst_node : t1->destinations_) {
+          if (nodes_dependency[t0_src_node].IsBitTrue(dst_node->GetId()) == false) {
+            reuse = false;
+            all_dst_depend = false;
+            break;
+          } else if (t0_src_node == dst_node->GetId()) {
+            reuse = false;
+            all_dst_depend = true;
+            break;
+          } else {
+            reuse = true;
+            all_dst_depend = true;
           }
         }
       }
-    }
-  }
 
-  // Loop for same stream
-  for (auto stream : streams_list_) {
-    MS_EXCEPTION_IF_NULL(stream);
-    for (auto tensor1 : stream->tensors_) {
-      if (tensor1->GetAlignedSize() == 0) continue;
-      if (tensor1->IsLifelong()) continue;
-      if (tensor1->IsRefOverlap()) continue;
-
-      for (auto tensor2 : stream->tensors_) {
-        if (tensor2->GetId() >= tensor1->GetId())
-          break;  // keep only when tensors kept sorted in tensors-vector of each stream, otherwise remove
-
-        if (tensor2->GetAlignedSize() == 0) continue;
-        if (tensor2->IsLifelong()) continue;
-        if (tensor2->IsRefOverlap()) continue;
-
-        // Between streams extra safety
-        if (tensor1->IsBetweenStreams() && tensor2->IsBetweenStreams()) continue;
-
-        // Check lifetime overlap
-        lifetime_t lifetime1 = tensor1->lifetime_;
-        lifetime_t lifetime2 = tensor2->lifetime_;
-
-        if (!LifetimeOverlap(lifetime1, lifetime2)) {
-          // Between-streams extra safety
-          if (tensor1->IsBetweenStreams() && lifetime1.end_ < lifetime2.start_) continue;
-          if (tensor2->IsBetweenStreams() && lifetime2.end_ < lifetime1.start_) continue;
-
-          // Semi-lifelong extra safety
-          if (lifetime1.end_ < lifetime2.start_ && (tensor2->IsSemiLifelongStart() || tensor1->IsSemiLifelongEnd()))
-            continue;
-          if (lifetime2.end_ < lifetime1.start_ && (tensor1->IsSemiLifelongStart() || tensor2->IsSemiLifelongEnd()))
-            continue;
-
-          // If arrived here, allow reuse
-          (*cannot_reuse_)(tensor2->GetId(), tensor1->GetId()) = 0;
-          (*cannot_reuse_)(tensor1->GetId(), tensor2->GetId()) = 0;
-          count_reuse++;
-        }
+      if (all_dst_depend == true && reuse == true) {
+        tensor_relation[t0->GetId()].SetBitTrue(t1->GetId());
+        tensor_relation[t1->GetId()].SetBitTrue(t0->GetId());
       }
     }
   }
-
-  MS_LOG(INFO) << "End Conflict Computing";
-  MS_LOG(INFO) << "Found " << count_reuse << " tensor pairs of allowed reusability";
+  MS_LOG(INFO) << "End Tensor Relation Computing";
+  MS_LOG(INFO) << "End Conflict Computing (Bitset Model)";
 }
 
+bool Somas::NodeSort(SomasNodePtr node1, SomasNodePtr node2) { return node1->GetId() < node2->GetId(); }
+
 bool Somas::Assign(const session::KernelGraph *graph) {
   if (tensors_list_.empty()) {
     MS_LOG(INFO) << "No Tensor for Assigner";
@@ -795,13 +731,13 @@ bool Somas::Assign(const session::KernelGraph *graph) {
     // Keep all constraints for first tensor in list
     size_t tid_0 = ref_node_list[0];
     for (SomasTensorPtr tensor : tensors_list_) {
-      if ((*cannot_reuse_)(tid_0, tensor->GetId()) == 1) {
+      if (tensor_relation[tid_0].IsBitTrue(tensor->GetId()) == false) {
         continue;
       }
       for (size_t tid : ref_node_list) {
-        if ((*cannot_reuse_)(tid, tensor->GetId()) == 1) {
-          (*cannot_reuse_)(tid_0, tensor->GetId()) = 1;
-          (*cannot_reuse_)(tensor->GetId(), tid_0) = 1;
+        if (tensor_relation[tid].IsBitTrue(tensor->GetId()) == false) {
+          tensor_relation[tid_0].SetBitFalse(tensor->GetId());
+          tensor_relation[tensor->GetId()].SetBitFalse(tid_0);
           break;
         }
       }
@@ -921,8 +857,8 @@ bool Somas::Assign(const session::KernelGraph *graph) {
   for (auto ref_overlap_list : ref_overlap_constraints_) {
     for (size_t tid_1 : ref_overlap_list) {
       for (size_t tid_2 : ref_overlap_list) {
-        (*cannot_reuse_)(tid_1, tid_2) = 0;
-        (*cannot_reuse_)(tid_2, tid_1) = 0;
+        tensor_relation[tid_1].SetBitTrue(tid_2);
+        tensor_relation[tid_2].SetBitTrue(tid_1);
       }
     }
   }
@@ -932,7 +868,7 @@ bool Somas::Assign(const session::KernelGraph *graph) {
   for (auto tensor1 : tensors_list_) {
     size_t count_constraints = 0;
     for (auto tensor2 : tensors_list_) {
-      if ((*cannot_reuse_)(tensor1->GetId(), tensor2->GetId()) == 1) {
+      if (tensor_relation[tensor1->GetId()].IsBitTrue(tensor2->GetId()) == false) {
         count_constraints++;
       }
     }
@@ -943,7 +879,7 @@ bool Somas::Assign(const session::KernelGraph *graph) {
   MS_LOG(INFO) << "Start Contiguous Gaps Preprocessing";
   for (auto contiguous_list : contiguous_tensors_list_) {
     if (contiguous_list.size() < 3) {
-      MS_LOG(ERROR) << "contiguous_list should has at least one input and two gap, now it is "
+      MS_LOG(ERROR) << "contiguous_list should have at least one input and two gap, now it is "
                     << contiguous_list.size();
     }
     size_t front_gap_id = contiguous_list[0];
@@ -959,10 +895,20 @@ bool Somas::Assign(const session::KernelGraph *graph) {
     size_t back_neighbour_id = contiguous_list[contiguous_list.size() - 2];
     for (SomasTensorPtr tensor : tensors_list_) {
       MS_EXCEPTION_IF_NULL(tensor);
-      (*cannot_reuse_)(tensor->GetId(), front_gap_id) = (*cannot_reuse_)(tensor->GetId(), front_neighbour_id);
-      (*cannot_reuse_)(front_gap_id, tensor->GetId()) = (*cannot_reuse_)(front_neighbour_id, tensor->GetId());
-      (*cannot_reuse_)(tensor->GetId(), back_gap_id) = (*cannot_reuse_)(tensor->GetId(), back_neighbour_id);
-      (*cannot_reuse_)(back_gap_id, tensor->GetId()) = (*cannot_reuse_)(back_neighbour_id, tensor->GetId());
+      if (tensor_relation[tensor->GetId()].IsBitTrue(front_neighbour_id) == false) {
+        tensor_relation[tensor->GetId()].SetBitFalse(front_gap_id);
+        tensor_relation[front_gap_id].SetBitFalse(tensor->GetId());
+      } else {
+        tensor_relation[tensor->GetId()].SetBitTrue(front_gap_id);
+        tensor_relation[front_gap_id].SetBitTrue(tensor->GetId());
+      }
+      if (tensor_relation[tensor->GetId()].IsBitTrue(back_neighbour_id) == false) {
+        tensor_relation[tensor->GetId()].SetBitFalse(back_gap_id);
+        tensor_relation[back_gap_id].SetBitFalse(tensor->GetId());
+      } else {
+        tensor_relation[tensor->GetId()].SetBitTrue(back_gap_id);
+        tensor_relation[back_gap_id].SetBitTrue(tensor->GetId());
+      }
     }
     SomasTensorPtr front_neighbour = tensors_map_[front_neighbour_id];
     SomasTensorPtr back_neighbour = tensors_map_[back_neighbour_id];
@@ -995,8 +941,8 @@ bool Somas::Assign(const session::KernelGraph *graph) {
   }
 
   somas_solver_ = std::make_shared<SomasSolverPre>();
-  auto status =
-    somas_solver_->Solving(graph, &solver_tensor_desc_list_, cannot_reuse_, contiguous_tensors_list_removed_ref, false);
+  auto status = somas_solver_->Solving(graph, &solver_tensor_desc_list_, &tensor_relation,
+                                       contiguous_tensors_list_removed_ref, false);
   MS_LOG(INFO) << "End Solving";
   if (status != SUCCESS) {
     GenStatisticInfo();
diff --git a/mindspore/ccsrc/backend/optimizer/somas/somas.h b/mindspore/ccsrc/backend/optimizer/somas/somas.h
index 8d5261ec90..d3e8c4f2c3 100644
--- a/mindspore/ccsrc/backend/optimizer/somas/somas.h
+++ b/mindspore/ccsrc/backend/optimizer/somas/somas.h
@@ -51,6 +51,9 @@ class Somas {
   void DumpSomasBasicIR(const string filename);
   void DumpSomasMemoryIR(const string filename);
 
+  static bool NodeSort(SomasNodePtr, SomasNodePtr);
+  std::vector<DynamicBitSet> tensor_relation;
+
  private:
   // Maps
   std::unordered_map<size_t, SomasTensorPtr> tensors_map_;
@@ -68,9 +71,6 @@ class Somas {
   std::unordered_map<size_t, SomasSolverTensorDescPtr> solver_tensor_desc_list_;
   SomasSolverPrePtr somas_solver_;
 
-  // Constraints
-  std::shared_ptr<Array> cannot_reuse_;
-
   // Contiguous list
   std::vector<vector<size_t>> contiguous_tensors_list_;
 
diff --git a/mindspore/ccsrc/backend/optimizer/somas/somas_node.h b/mindspore/ccsrc/backend/optimizer/somas/somas_node.h
index 49a2728c78..a253b66341 100644
--- a/mindspore/ccsrc/backend/optimizer/somas/somas_node.h
+++ b/mindspore/ccsrc/backend/optimizer/somas/somas_node.h
@@ -42,8 +42,8 @@ class SomasNode {
   // Public attributes (mutated in code)
   std::string scope_full_name_;
 
-  std::set<SomasNodePtr>
-    ancestor_nodes_;  // keeping only distance *one* ancestor nodes; enough to ComputeAncestorNodes()
+  // node's dependency including data dependency and time dependency
+  std::set<SomasNodePtr> ancestor_nodes_;
   std::set<SomasTensorPtr> tensors_;
 
   std::vector<SomasTensorPtr> input_tensors_;
diff --git a/mindspore/ccsrc/backend/optimizer/somas/somas_solver_alg.cc b/mindspore/ccsrc/backend/optimizer/somas/somas_solver_alg.cc
index d5712190fa..c699fdfc6a 100644
--- a/mindspore/ccsrc/backend/optimizer/somas/somas_solver_alg.cc
+++ b/mindspore/ccsrc/backend/optimizer/somas/somas_solver_alg.cc
@@ -117,15 +117,15 @@ void FootPrint::Merge(vector<Interval> *interval_v, stack<Interval> *s) {
 
   return;
 }
-void FootPrint::ConstrainedBLocks(const std::shared_ptr<Array> &constraints, const BlockTensor &b1,
-                                  const BlockTensor &b2, vector<Interval> *oInterval) {
+void FootPrint::ConstrainedBLocks(std::vector<DynamicBitSet> *constraints, const BlockTensor &b1, const BlockTensor &b2,
+                                  vector<Interval> *oInterval) {
   MS_EXCEPTION_IF_NULL(oInterval);
   // propagate
   size_t acum = m_offset_;
 
   for (SomasSolverTensorDescPtr p1 = b1.m_start_tensor_; NULL != p1; p1 = p1->right_) {
     for (SomasSolverTensorDescPtr p2 = b2.m_start_tensor_; NULL != p2; p2 = p2->right_) {
-      if ((*constraints)(p1->index_, p2->index_) == 1) {
+      if ((*constraints)[p1->index_].IsBitTrue(p2->index_) == false) {
         Interval a = Interval(acum, acum + p1->size_);
         Interval b = Interval(p2);
         if (a.lb() < b.ub()) {
@@ -136,7 +136,7 @@ void FootPrint::ConstrainedBLocks(const std::shared_ptr<Array> &constraints, con
     acum += p1->size_;
   }
 }
-bool FootPrint::findOffset(const std::shared_ptr<Array> &constraints, const BlockTensor &block, size_t *offset) {
+bool FootPrint::findOffset(std::vector<DynamicBitSet> *constraints, const BlockTensor &block, size_t *offset) {
   MS_EXCEPTION_IF_NULL(offset);
   bool bretval = true;
   vector<Interval> l_interval;
@@ -150,7 +150,7 @@ bool FootPrint::findOffset(const std::shared_ptr<Array> &constraints, const Bloc
   // transform constrained tensors in non eligible intervals
   for (size_t i = 0; i < m_starts_.size(); i++) {
     if (block.Alone() && m_starts_[i]->Alone() &&
-        (*constraints)(block.m_start_tensor_->index_, m_starts_[i]->m_start_tensor_->index_)) {
+        (*constraints)[block.m_start_tensor_->index_].IsBitTrue(m_starts_[i]->m_start_tensor_->index_) == false) {
       if (m_algorithm_ != 1 && i == 0) return false;
       Interval It = Interval(m_starts_[i]->m_start_tensor_);
       l_interval.emplace_back(It);
@@ -201,7 +201,7 @@ void FootPrint::printStats() {
   MS_LOG(DEBUG) << "Footprint blocks: " << m_starts_.size() << " \toffset: " << m_offset_;
 }
 bool FastHeuristic::Eval(vector<BlockTensor> *block_tensors_v, std::shared_ptr<FootPrint> foot_print,
-                         const std::shared_ptr<Array> &pConstraints) {
+                         std::vector<DynamicBitSet> *pConstraints) {
   MS_EXCEPTION_IF_NULL(foot_print);
   auto start = std::chrono::system_clock::now();
 
diff --git a/mindspore/ccsrc/backend/optimizer/somas/somas_solver_alg.h b/mindspore/ccsrc/backend/optimizer/somas/somas_solver_alg.h
index ef34a2242c..651fe4b75b 100644
--- a/mindspore/ccsrc/backend/optimizer/somas/somas_solver_alg.h
+++ b/mindspore/ccsrc/backend/optimizer/somas/somas_solver_alg.h
@@ -143,8 +143,8 @@ class FootPrint : public std::enable_shared_from_this<FootPrint> {
   void Destroy();
   const size_t getOffset() { return m_offset_; }
   void setOffset(const size_t &offset) { m_offset_ = offset; }
-  bool findOffset(const std::shared_ptr<Array> &constraints, const BlockTensor &block, size_t *offset);
-  void ConstrainedBLocks(const std::shared_ptr<Array> &constraints, const BlockTensor &b1, const BlockTensor &b2,
+  bool findOffset(std::vector<DynamicBitSet> *constraints, const BlockTensor &block, size_t *offset);
+  void ConstrainedBLocks(std::vector<DynamicBitSet> *constraints, const BlockTensor &b1, const BlockTensor &b2,
                          vector<Interval> *oInterval_l);
   void Merge(vector<Interval> *l_interval, stack<Interval> *l_merged);
   bool findFirst(stack<Interval> *merged, const BlockTensor &block, size_t *offset);
@@ -167,7 +167,7 @@ class FastHeuristic {
   void setAlignment(const size_t &a) { m_alignment_ = a; }
   void Destroy();
   bool Eval(vector<BlockTensor> *block_tensors_v, std::shared_ptr<FootPrint> foot_print,
-            const std::shared_ptr<Array> &pConstraints);
+            std::vector<DynamicBitSet> *pConstraints);
 
  private:
   size_t m_alignment_;
diff --git a/mindspore/ccsrc/backend/optimizer/somas/somas_solver_core.cc b/mindspore/ccsrc/backend/optimizer/somas/somas_solver_core.cc
index 56269622d7..affb0345cb 100644
--- a/mindspore/ccsrc/backend/optimizer/somas/somas_solver_core.cc
+++ b/mindspore/ccsrc/backend/optimizer/somas/somas_solver_core.cc
@@ -169,16 +169,14 @@ bool SomasSolverCore::Verify(const size_t &upperbound) {
       t2 = t2_.second;
       if (t1->index_ == t2->index_) continue;
       bool blifelong = (t1->lifelong_ || t2->lifelong_) && (t1->index_ != t2->index_);
-      const size_t continuous = 2;
-      const size_t conflict = 1;
-      if ((*constraints_)(t1->index_, t2->index_) == continuous) {  // continuous constraint
-        // t1 must be continous to t2
+      if (t2->right_ == t1) {  // continuous constraint
+        // t1 must be continuous to t2
         bool bcontinuous = t1->offset_ == (t2->offset_ + t2->size_);
         if (!bcontinuous) {
           MS_LOG(WARNING) << "Continuous constraint violation in tensors " << t1->index_ << " and" << t2->index_;
           retval = false;
         }
-      } else if (blifelong || (*constraints_)(t1->index_, t2->index_) == conflict) {  // conflict constraint
+      } else if (blifelong || constraints_[t1->index_].IsBitTrue(t2->index_) == false) {  // conflict constraint
         size_t t1_ub = t1->offset_ + t1->size_;
         size_t t2_ub = t2->offset_ + t2->size_;
         bool b_overlap_lb = ((t2->offset_ >= t1->offset_) && (t2->offset_ < t1_ub));
@@ -336,7 +334,7 @@ size_t SomasSolverCore::Search(const std::shared_ptr<FootPrint> &pFootprint) {
   FastHeuristic fh;
   MS_LOG(INFO) << "Calling FastSolver Search for " << block_tensors_.size() << " tensors ";
   auto start = std::chrono::system_clock::now();
-  if (fh.Eval(&block_tensors_, pFootprint, constraints_)) {
+  if (fh.Eval(&block_tensors_, pFootprint, &constraints_)) {
     result = pFootprint->Result();
     auto end = std::chrono::system_clock::now();
     timing_ = std::chrono::duration_cast<std::chrono::milliseconds>((end - start)).count();
diff --git a/mindspore/ccsrc/backend/optimizer/somas/somas_solver_core.h b/mindspore/ccsrc/backend/optimizer/somas/somas_solver_core.h
index ed07730f78..90a6ed8dd3 100644
--- a/mindspore/ccsrc/backend/optimizer/somas/somas_solver_core.h
+++ b/mindspore/ccsrc/backend/optimizer/somas/somas_solver_core.h
@@ -33,9 +33,9 @@ class SomasSolverCore {
  public:
   /// Interface Function: receive parameters, creates the model to solve and then save the result
   SomasSolverCore(const std::unordered_map<size_t, SomasSolverTensorDescPtr> &tensors,
-                  const std::shared_ptr<Array> &constraints)
+                  std::vector<DynamicBitSet> *constraints)
       : tensors_(tensors),
-        constraints_(constraints),
+        constraints_(*constraints),
         upperbound_(SIZE_MAX),
         timing_(0),
         lifelongmemory_(0),
@@ -69,7 +69,7 @@ class SomasSolverCore {
  private:
   std::unordered_map<size_t, SomasSolverTensorDescPtr> tensors_;
   vector<BlockTensor> block_tensors_;
-  std::shared_ptr<Array> constraints_;
+  std::vector<DynamicBitSet> constraints_;
   size_t upperbound_{0};
   size_t timing_{0};
   size_t lifelongmemory_{0};
diff --git a/mindspore/ccsrc/backend/optimizer/somas/somas_solver_pre.cc b/mindspore/ccsrc/backend/optimizer/somas/somas_solver_pre.cc
index ce72a217bf..babd08ae8a 100644
--- a/mindspore/ccsrc/backend/optimizer/somas/somas_solver_pre.cc
+++ b/mindspore/ccsrc/backend/optimizer/somas/somas_solver_pre.cc
@@ -27,25 +27,15 @@ namespace mindspore {
 namespace somas {
 Status SomasSolverPre::Solving(const session::KernelGraph *graph,
                                std::unordered_map<size_t, SomasSolverTensorDescPtr> *ptensors,
-                               std::shared_ptr<Array> pConstraints, const vector<vector<size_t>> &continuous_v,
+                               std::vector<DynamicBitSet> *pConstraints, const vector<vector<size_t>> &continuous_v,
                                bool bVerifySolution, bool ball, SortingType sorting, FittingType fitting,
                                AlgorithmType algorithm) {
   Status retval = SUCCESS;
 
   try {
     std::unordered_map<size_t, SomasSolverTensorDescPtr> &tensors = *ptensors;
-    std::unordered_map<size_t, SomasSolverTensorDescPtr>::iterator max =
-      std::max_element(tensors.begin(), tensors.end(),
-                       [](const std::pair<size_t, SomasSolverTensorDescPtr> &a,
-                          const std::pair<size_t, SomasSolverTensorDescPtr> &b) { return a.first < b.first; });
-    size_t maxIndex = max->first;
-    if (maxIndex > pConstraints->Rows() - 1) {
-      MS_LOG(WARNING) << "ERROR: MaxIndex invalid, MaxIndex " << maxIndex << ", Rows " << pConstraints->Rows();
-      return FAILED;
-    }
     MS_LOG(INFO) << "Filling in constraints matrix..";
     uint32_t continuous_cnt = 0;
-
     // creating S Lists
     for (auto &aux : continuous_v) {
       for (uint32_t i = 0; i < aux.size() - 1; i++) {
@@ -60,8 +50,6 @@ Status SomasSolverPre::Solving(const session::KernelGraph *graph,
           return FAILED;
         }
 
-        const size_t continuous = 2;
-        (*pConstraints)(index2, index1) = continuous;
         if (tensors[index1]->right_)
           MS_LOG(WARNING) << "Warning:tensor " << index1
                           << " already has a right tensor (id: " << tensors[index1]->right_->index_;
@@ -104,7 +92,7 @@ Status SomasSolverPre::Solving(const session::KernelGraph *graph,
 
 void SomasSolverPre::Log(const session::KernelGraph *graph,
                          const unordered_map<size_t, SomasSolverTensorDescPtr> &tensors,
-                         const std::shared_ptr<Array> &pConstraints, const vector<vector<size_t>> &continuous_v) {
+                         std::vector<DynamicBitSet> *pConstraints, const vector<vector<size_t>> &continuous_v) {
   MS_LOG(INFO) << "SomasSolver::Log Writing somas-input.txt..";
 
   auto context_ptr = MsContext::GetInstance();
@@ -143,7 +131,7 @@ void SomasSolverPre::Log(const session::KernelGraph *graph,
     for (auto &t2 : tensors) {
       size_t idx1 = t1.first;
       size_t idx2 = t2.first;
-      if ((idx1 != idx2) && (*pConstraints)(idx1, idx2) == 1) {
+      if ((idx1 != idx2) && (*pConstraints)[idx1].IsBitTrue(idx2) == false) {
         ofs_1 << "C " << idx1 << " " << idx2 << std::endl;
       }
     }
diff --git a/mindspore/ccsrc/backend/optimizer/somas/somas_solver_pre.h b/mindspore/ccsrc/backend/optimizer/somas/somas_solver_pre.h
index d331b2d95e..390fb3c5cf 100644
--- a/mindspore/ccsrc/backend/optimizer/somas/somas_solver_pre.h
+++ b/mindspore/ccsrc/backend/optimizer/somas/somas_solver_pre.h
@@ -57,36 +57,52 @@ enum FittingType {
   kNumFittingTypes
 };
 
-class Array {
- public:
-  Array(const size_t &rows, const size_t &cols) : rows_(rows), cols_(cols) {
-    conflicts_array_ = std::make_unique<int[]>(rows * cols);
-    for (uint32_t i = 0; i < rows * cols; i++) {
-      conflicts_array_[i] = 1;
+class DynamicBitSet {
+  const size_t bit_width_ = 64;
+  size_t bit_size_;
+  std::vector<uint64_t> bit_;
+
+  inline size_t GetIndex(size_t index) { return index / bit_width_; }
+
+  inline uint64_t GetBitMask(size_t index) { return (((uint64_t)0x1) << (bit_width_ - 1 - (index % bit_width_))); }
+
+  inline void Reset(uint64_t val) {
+    bit_.clear();
+    for (size_t i = 0; i < bit_size_; i++) {
+      bit_.push_back(val);
     }
   }
 
-  Array(const Array &array) : rows_(array.rows_), cols_(array.cols_) {
-    conflicts_array_ = std::make_unique<int[]>(array.rows_ * array.cols_);
-    for (uint32_t i = 0; i < array.rows_ * array.cols_; i++) {
-      conflicts_array_[i] = array.conflicts_array_[i];
+ public:
+  explicit DynamicBitSet(size_t count) {
+    bit_size_ = (count + bit_width_ - 1) / bit_width_;
+    Reset(0x0);
+  }
+
+  void SetBitTrue(size_t index, bool log = false) {
+    if (log) {
+      MS_LOG(INFO) << GetIndex(index) << " " << GetBitMask(index);
     }
+    bit_[GetIndex(index)] |= GetBitMask(index);
   }
 
-  Array &operator=(const Array &array) { return *this; }
+  void SetBitFalse(size_t index) { bit_[GetIndex(index)] &= (~GetBitMask(index)); }
 
-  int &operator()(const size_t &i, const size_t &j) {
-    assert((i * cols_ + j) < (rows_ * cols_));
-    return conflicts_array_[i * cols_ + j];
-  }
+  bool IsBitTrue(size_t index) { return (bit_[GetIndex(index)] & GetBitMask(index)) != 0x0; }
 
-  const size_t &Rows() { return rows_; }
-  const size_t &Cols() { return cols_; }
+  void Log() {
+    std::cout << "Start Print Bitset ";
+    for (size_t i = 0; i < bit_size_; i++) {
+      std::cout << " bit [" << std::dec << i << "] = " << std::hex << bit_[i] << std::dec;
+    }
+    std::cout << std::endl;
+  }
 
- private:
-  const size_t rows_;
-  const size_t cols_;
-  std::unique_ptr<int[]> conflicts_array_;
+  friend void Union(DynamicBitSet *a, DynamicBitSet *b) {
+    for (size_t i = 0; i < (*a).bit_size_; i++) {
+      (*a).bit_[i] |= (*b).bit_[i];
+    }
+  }
 };
 
 struct SomasSolverTensorDesc {
@@ -140,14 +156,14 @@ class SomasSolverPre {
   size_t GetMaxOffset() { return max_offset_; }
 
   Status Solving(const session::KernelGraph *graph, std::unordered_map<size_t, SomasSolverTensorDescPtr> *tensors,
-                 std::shared_ptr<Array> pConstraints, const vector<vector<size_t>> &continuous_v,
+                 std::vector<DynamicBitSet> *pConstraints, const vector<vector<size_t>> &continuous_v,
                  bool bVerifySolution,  // true -> Check continuous and non overlapping constraints solution
                  bool ball = true,      // true -> run full set of heuristics, false -> run single heuristic specified
                  SortingType sorting = kGreaterSizeSmallerIndex, FittingType fitting = kBest,
                  AlgorithmType algorithm = kManyObjects);
 
   void Log(const session::KernelGraph *graph, const unordered_map<size_t, SomasSolverTensorDescPtr> &tensors,
-           const std::shared_ptr<Array> &pConstraints_v, const vector<vector<size_t>> &continuous_v);
+           std::vector<DynamicBitSet> *pConstraints_v, const vector<vector<size_t>> &continuous_v);
 
  private:
   size_t max_offset_;
diff --git a/mindspore/ccsrc/backend/optimizer/somas/somas_stream.h b/mindspore/ccsrc/backend/optimizer/somas/somas_stream.h
index 9cd421334b..c924eb47de 100644
--- a/mindspore/ccsrc/backend/optimizer/somas/somas_stream.h
+++ b/mindspore/ccsrc/backend/optimizer/somas/somas_stream.h
@@ -34,11 +34,13 @@ using SomasTensorPtr = std::shared_ptr<SomasTensor>;
 class SomasStream {
  public:
   using SomasStreamPtr = std::shared_ptr<SomasStream>;
+  using SomasNodePtr = std::shared_ptr<SomasNode>;
 
   // Attributes mutated in code
   std::vector<SomasTensorPtr> tensors_;  // vector needed for same-stream loop in ConflictComputing()
   std::set<SomasStreamPtr> ancestor_streams_;
   std::set<SomasStreamPtr> ancestor_streams_group_;
+  std::vector<SomasNodePtr> nodes_;
 
   // Constructors/Destructors
   explicit SomasStream(int64_t id) : id_(id) {}