From 8e6d92eac904ebb374da1e7307e48397194d4f81 Mon Sep 17 00:00:00 2001
From: dayschan <chendeshi@huawei.com>
Date: Fri, 13 Nov 2020 11:55:11 +0800
Subject: [PATCH] Fuse composite ops separated by GetItem nodes

---
 .../graph_kernel/composite_ops_fusion.cc      | 92 ++++++++++++++++---
 1 file changed, 81 insertions(+), 11 deletions(-)

diff --git a/mindspore/ccsrc/backend/optimizer/graph_kernel/composite_ops_fusion.cc b/mindspore/ccsrc/backend/optimizer/graph_kernel/composite_ops_fusion.cc
index 2914dd09c8b..1dc017ba1c1 100644
--- a/mindspore/ccsrc/backend/optimizer/graph_kernel/composite_ops_fusion.cc
+++ b/mindspore/ccsrc/backend/optimizer/graph_kernel/composite_ops_fusion.cc
@@ -36,6 +36,7 @@
 #include "debug/anf_ir_dump.h"
 #include "ir/func_graph_cloner.h"
 #include "backend/optimizer/graph_kernel/graph_kernel_helper.h"
+#include "backend/optimizer/pass/getitem_tuple.h"
 
 namespace mindspore {
 namespace opt {
@@ -60,20 +61,20 @@ std::vector<AnfNodePtr> DeepUsersSearch(const std::vector<AnfNodePtr> &roots, co
 }
 }  // namespace
 
-bool IsFuse(const AnfNodePtr &node) {
-  // composite fuse composite op
-  if (AnfAlgo::IsGraphKernel(node)) {
-    return true;
-  }
-  return IsBasicFuseOp(node);
-}
-
 IncludeType IncludeFusedBasicOpForward(const AnfNodePtr &cur_node, const AnfNodePtr &node) {
   if (cur_node == node) {
     return FOLLOW;
   }
-  bool is_fusable = IsFuse(node);
-  return is_fusable ? FOLLOW : EXCLUDE;
+  if (AnfAlgo::IsGraphKernel(node) || IsBasicFuseOp(node)) {
+    return FOLLOW;
+  }
+  if (AnfAlgo::CheckPrimitiveType(node, prim::kPrimTupleGetItem)) {
+    auto prev_node = node->cast<CNodePtr>()->input(kRealInputNodeIndexInTupleGetItem);
+    if (AnfAlgo::IsGraphKernel(prev_node)) {
+      return FOLLOW;
+    }
+  }
+  return EXCLUDE;
 }
 
 IncludeType IncludeFusedBasicOpBackward(const AnfNodePtr &cur_node, const AnfNodePtr &node) {
@@ -185,6 +186,60 @@ std::vector<AnfNodePtr> RemoveCircle(const std::vector<AnfNodePtr> &fused_op, bo
   return res;
 }
 
+// The GetItem node should be fused with its real input and users.
+// If its real input is not in the fuse_list, the GetItem should be excluded.
+AnfNodePtrList RemoveWildGetitem(const AnfNodePtrList &fused_op) {
+  if (fused_op.empty()) return AnfNodePtrList();
+  std::set<AnfNodePtr> fused_op_set(fused_op.begin(), fused_op.end());
+  auto check_include = [&fused_op_set](const AnfNodePtr &node) { return fused_op_set.count(node) ? FOLLOW : EXCLUDE; };
+
+  auto mng = fused_op[0]->func_graph()->manager();
+  MS_EXCEPTION_IF_NULL(mng);
+  bool changed = true;
+  while (changed) {
+    changed = false;
+    AnfNodePtrList remove_list;
+    for (auto node : fused_op_set) {
+      if (!AnfAlgo::CheckPrimitiveType(node, prim::kPrimTupleGetItem)) continue;
+      // GetItem should be fused with its real input.
+      auto prev_node = node->cast<CNodePtr>()->input(kRealInputNodeIndexInTupleGetItem);
+      if (check_include(prev_node) == EXCLUDE) {
+        remove_list.push_back(node);
+        break;
+      }
+
+      // GetItem should be fused with its all users.
+      auto &users = mng->node_users()[node];
+      bool outside_user_found = false;
+      for (auto iter = users.begin(); iter != users.end(); ++iter) {
+        if (check_include(iter->first) == EXCLUDE) {
+          outside_user_found = true;
+          break;
+        }
+      }
+      if (outside_user_found) {
+        remove_list = DeepUsersSearch(node, check_include, mng);
+        break;
+      }
+    }
+    if (!remove_list.empty()) {
+      for (auto node : remove_list) {
+        fused_op_set.erase(node);
+      }
+      changed = true;
+    }
+  }
+
+  // keep the original order of fused_op.
+  AnfNodePtrList result;
+  for (auto node : fused_op) {
+    if (fused_op_set.count(node)) {
+      result.push_back(node);
+    }
+  }
+  return result;
+}
+
 void TopoSortForNodeList(std::vector<AnfNodePtr> *lst) {
   if (lst->size() < 2) {
     return;
@@ -254,6 +309,7 @@ std::vector<AnfNodePtr> FindFuseCNodes(const CNodePtr &cnode) {
   if (used_nodes.size() > 1) {
     used_nodes = RemoveCircle(used_nodes);
   }
+  used_nodes = RemoveWildGetitem(used_nodes);
   TopoSortForNodeList(&used_nodes);
   return used_nodes;
 }
@@ -288,8 +344,22 @@ bool FuseCompositeOps(const std::shared_ptr<session::KernelGraph> &kernel_graph)
   return changed;
 }
 
+void EliminateGetItem(const FuncGraphPtr &func_graph) {
+  std::shared_ptr<Pass> eliminate_getitem_pass = std::make_shared<opt::GetitemTuple>();
+  auto todos = TopoSort(func_graph->get_return());
+  for (auto node : todos) {
+    if (AnfAlgo::IsGraphKernel(node)) {
+      eliminate_getitem_pass->Run(AnfAlgo::GetCNodeFuncGraphPtr(node));
+    }
+  }
+}
+
 bool CompositeOpsFusion::Run(const FuncGraphPtr &func_graph) {
-  return FuseCompositeOps(std::dynamic_pointer_cast<session::KernelGraph>(func_graph));
+  auto changed = FuseCompositeOps(std::dynamic_pointer_cast<session::KernelGraph>(func_graph));
+  if (changed) {
+    EliminateGetItem(func_graph);
+  }
+  return changed;
 }
 }  // namespace opt
 }  // namespace mindspore