Add Schedule::InsertBranch to fuse control flow graphs.

R=jarin@chromium.org
TEST=cctest/test-schedule/TestScheduleInsertBranch

Review URL: https://codereview.chromium.org/675983002

Cr-Commit-Position: refs/heads/master@{#24876}
git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24876 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/compiler/schedule.cc

@@ -51,7 +51,6 @@ void BasicBlock::AddNode(Node* node) { nodes_.push_back(node); }
 
 
 void BasicBlock::set_control(Control control) {
-  DCHECK(control_ == BasicBlock::kNone);
   control_ = control;
 }
 
@@ -215,12 +214,42 @@ void Schedule::AddThrow(BasicBlock* block, Node* input) {
 }
 
 
+void Schedule::InsertBranch(BasicBlock* block, BasicBlock* end, Node* branch,
+                            BasicBlock* tblock, BasicBlock* fblock) {
+  DCHECK(block->control() != BasicBlock::kNone);
+  DCHECK(end->control() == BasicBlock::kNone);
+  end->set_control(block->control());
+  block->set_control(BasicBlock::kBranch);
+  MoveSuccessors(block, end);
+  AddSuccessor(block, tblock);
+  AddSuccessor(block, fblock);
+  if (block->control_input() != NULL) {
+    SetControlInput(end, block->control_input());
+  }
+  SetControlInput(block, branch);
+}
+
+
 void Schedule::AddSuccessor(BasicBlock* block, BasicBlock* succ) {
   block->AddSuccessor(succ);
   succ->AddPredecessor(block);
 }
 
 
+void Schedule::MoveSuccessors(BasicBlock* from, BasicBlock* to) {
+  for (BasicBlock::Predecessors::iterator i = from->successors_begin();
+       i != from->successors_end(); ++i) {
+    BasicBlock* succ = *i;
+    to->AddSuccessor(succ);
+    for (BasicBlock::Predecessors::iterator j = succ->predecessors_begin();
+         j != succ->predecessors_end(); ++j) {
+      if (*j == from) *j = to;
+    }
+  }
+  from->ClearSuccessors();
+}
+
+
 void Schedule::SetControlInput(BasicBlock* block, Node* node) {
   block->set_control_input(node);
   SetBlockForNode(block, node);

src/compiler/schedule.h

@@ -95,6 +95,7 @@ class BasicBlock FINAL : public ZoneObject {
   }
   size_t PredecessorCount() const { return predecessors_.size(); }
   BasicBlock* PredecessorAt(size_t index) { return predecessors_[index]; }
+  void ClearPredecessors() { predecessors_.clear(); }
   void AddPredecessor(BasicBlock* predecessor);
 
   typedef ZoneVector<BasicBlock*> Successors;
@@ -108,6 +109,7 @@ class BasicBlock FINAL : public ZoneObject {
   }
   size_t SuccessorCount() const { return successors_.size(); }
   BasicBlock* SuccessorAt(size_t index) { return successors_[index]; }
+  void ClearSuccessors() { successors_.clear(); }
   void AddSuccessor(BasicBlock* successor);
 
   // Nodes in the basic block.
@@ -240,7 +242,14 @@ class Schedule FINAL : public ZoneObject {
   // BasicBlock building: add a throw at the end of {block}.
   void AddThrow(BasicBlock* block, Node* input);
 
-  void AddSuccessor(BasicBlock* block, BasicBlock* succ);
+  // BasicBlock mutation: insert a branch into the end of {block}.
+  void InsertBranch(BasicBlock* block, BasicBlock* end, Node* branch,
+                    BasicBlock* tblock, BasicBlock* fblock);
+
+  // Exposed publicly for testing only.
+  void AddSuccessorForTesting(BasicBlock* block, BasicBlock* succ) {
+    return AddSuccessor(block, succ);
+  }
 
   BasicBlockVector* rpo_order() { return &rpo_order_; }
   const BasicBlockVector* rpo_order() const { return &rpo_order_; }
@@ -256,6 +265,9 @@ class Schedule FINAL : public ZoneObject {
   friend class ScheduleVisualizer;
   friend class BasicBlockInstrumentor;
 
+  void AddSuccessor(BasicBlock* block, BasicBlock* succ);
+  void MoveSuccessors(BasicBlock* from, BasicBlock* to);
+
   void SetControlInput(BasicBlock* block, Node* node);
   void SetBlockForNode(BasicBlock* block, Node* node);
 

test/cctest/compiler/test-schedule.cc

@@ -30,12 +30,11 @@ TEST(TestScheduleAllocation) {
 
 TEST(TestScheduleAddNode) {
   HandleAndZoneScope scope;
+  Schedule schedule(scope.main_zone());
   Graph graph(scope.main_zone());
   Node* n0 = graph.NewNode(&dummy_operator);
   Node* n1 = graph.NewNode(&dummy_operator);
 
-  Schedule schedule(scope.main_zone());
-
   BasicBlock* entry = schedule.start();
   schedule.AddNode(entry, n0);
   schedule.AddNode(entry, n1);
@@ -51,8 +50,8 @@ TEST(TestScheduleAddNode) {
 
 TEST(TestScheduleAddGoto) {
   HandleAndZoneScope scope;
-
   Schedule schedule(scope.main_zone());
+
   BasicBlock* entry = schedule.start();
   BasicBlock* next = schedule.NewBasicBlock();
 
@@ -71,16 +70,15 @@ TEST(TestScheduleAddGoto) {
 TEST(TestScheduleAddBranch) {
   HandleAndZoneScope scope;
   Schedule schedule(scope.main_zone());
-
-  BasicBlock* entry = schedule.start();
-  BasicBlock* tblock = schedule.NewBasicBlock();
-  BasicBlock* fblock = schedule.NewBasicBlock();
-
   Graph graph(scope.main_zone());
   CommonOperatorBuilder common(scope.main_zone());
   Node* n0 = graph.NewNode(&dummy_operator);
   Node* b = graph.NewNode(common.Branch(), n0);
 
+  BasicBlock* entry = schedule.start();
+  BasicBlock* tblock = schedule.NewBasicBlock();
+  BasicBlock* fblock = schedule.NewBasicBlock();
+
   schedule.AddBranch(entry, b, tblock, fblock);
 
   CHECK_EQ(0, static_cast<int>(entry->PredecessorCount()));
@@ -126,6 +124,40 @@ TEST(TestScheduleAddThrow) {
 }
 
 
+TEST(TestScheduleInsertBranch) {
+  HandleAndZoneScope scope;
+  Schedule schedule(scope.main_zone());
+  Graph graph(scope.main_zone());
+  CommonOperatorBuilder common(scope.main_zone());
+  Node* n0 = graph.NewNode(&dummy_operator);
+  Node* n1 = graph.NewNode(&dummy_operator);
+  Node* b = graph.NewNode(common.Branch(), n1);
+
+  BasicBlock* entry = schedule.start();
+  BasicBlock* tblock = schedule.NewBasicBlock();
+  BasicBlock* fblock = schedule.NewBasicBlock();
+  BasicBlock* merge = schedule.NewBasicBlock();
+  schedule.AddReturn(entry, n0);
+  schedule.AddGoto(tblock, merge);
+  schedule.AddGoto(fblock, merge);
+
+  schedule.InsertBranch(entry, merge, b, tblock, fblock);
+
+  CHECK_EQ(0, static_cast<int>(entry->PredecessorCount()));
+  CHECK_EQ(2, static_cast<int>(entry->SuccessorCount()));
+  CHECK_EQ(tblock, entry->SuccessorAt(0));
+  CHECK_EQ(fblock, entry->SuccessorAt(1));
+
+  CHECK_EQ(2, static_cast<int>(merge->PredecessorCount()));
+  CHECK_EQ(1, static_cast<int>(merge->SuccessorCount()));
+  CHECK_EQ(schedule.end(), merge->SuccessorAt(0));
+
+  CHECK_EQ(1, static_cast<int>(schedule.end()->PredecessorCount()));
+  CHECK_EQ(0, static_cast<int>(schedule.end()->SuccessorCount()));
+  CHECK_EQ(merge, schedule.end()->PredecessorAt(0));
+}
+
+
 TEST(BuildMulNodeGraph) {
   HandleAndZoneScope scope;
   Schedule schedule(scope.main_zone());

test/cctest/compiler/test-scheduler.cc

@@ -39,9 +39,11 @@ static TestLoop* CreateLoop(Schedule* schedule, int count) {
   loop->nodes = new BasicBlock* [count];
   for (int i = 0; i < count; i++) {
     loop->nodes[i] = schedule->NewBasicBlock();
-    if (i > 0) schedule->AddSuccessor(loop->nodes[i - 1], loop->nodes[i]);
+    if (i > 0) {
+      schedule->AddSuccessorForTesting(loop->nodes[i - 1], loop->nodes[i]);
+    }
   }
-  schedule->AddSuccessor(loop->nodes[count - 1], loop->nodes[0]);
+  schedule->AddSuccessorForTesting(loop->nodes[count - 1], loop->nodes[0]);
   return loop;
 }
 
@@ -160,7 +162,7 @@ TEST(RPOLine) {
 TEST(RPOSelfLoop) {
   HandleAndZoneScope scope;
   Schedule schedule(scope.main_zone());
-  schedule.AddSuccessor(schedule.start(), schedule.start());
+  schedule.AddSuccessorForTesting(schedule.start(), schedule.start());
   ZonePool zone_pool(scope.main_isolate());
   BasicBlockVector* order = Scheduler::ComputeSpecialRPO(&zone_pool, &schedule);
   CheckRPONumbers(order, 1, true);
@@ -172,8 +174,8 @@ TEST(RPOSelfLoop) {
 TEST(RPOEntryLoop) {
   HandleAndZoneScope scope;
   Schedule schedule(scope.main_zone());
-  schedule.AddSuccessor(schedule.start(), schedule.end());
-  schedule.AddSuccessor(schedule.end(), schedule.start());
+  schedule.AddSuccessorForTesting(schedule.start(), schedule.end());
+  schedule.AddSuccessorForTesting(schedule.end(), schedule.start());
   ZonePool zone_pool(scope.main_isolate());
   BasicBlockVector* order = Scheduler::ComputeSpecialRPO(&zone_pool, &schedule);
   CheckRPONumbers(order, 2, true);
@@ -186,7 +188,7 @@ TEST(RPOEndLoop) {
   HandleAndZoneScope scope;
   Schedule schedule(scope.main_zone());
   SmartPointer<TestLoop> loop1(CreateLoop(&schedule, 2));
-  schedule.AddSuccessor(schedule.start(), loop1->header());
+  schedule.AddSuccessorForTesting(schedule.start(), loop1->header());
   ZonePool zone_pool(scope.main_isolate());
   BasicBlockVector* order = Scheduler::ComputeSpecialRPO(&zone_pool, &schedule);
   CheckRPONumbers(order, 3, true);
@@ -198,8 +200,8 @@ TEST(RPOEndLoopNested) {
   HandleAndZoneScope scope;
   Schedule schedule(scope.main_zone());
   SmartPointer<TestLoop> loop1(CreateLoop(&schedule, 2));
-  schedule.AddSuccessor(schedule.start(), loop1->header());
-  schedule.AddSuccessor(loop1->last(), schedule.start());
+  schedule.AddSuccessorForTesting(schedule.start(), loop1->header());
+  schedule.AddSuccessorForTesting(loop1->last(), schedule.start());
   ZonePool zone_pool(scope.main_isolate());
   BasicBlockVector* order = Scheduler::ComputeSpecialRPO(&zone_pool, &schedule);
   CheckRPONumbers(order, 3, true);
@@ -216,10 +218,10 @@ TEST(RPODiamond) {
   BasicBlock* C = schedule.NewBasicBlock();
   BasicBlock* D = schedule.end();
 
-  schedule.AddSuccessor(A, B);
-  schedule.AddSuccessor(A, C);
-  schedule.AddSuccessor(B, D);
-  schedule.AddSuccessor(C, D);
+  schedule.AddSuccessorForTesting(A, B);
+  schedule.AddSuccessorForTesting(A, C);
+  schedule.AddSuccessorForTesting(B, D);
+  schedule.AddSuccessorForTesting(C, D);
 
   ZonePool zone_pool(scope.main_isolate());
   BasicBlockVector* order = Scheduler::ComputeSpecialRPO(&zone_pool, &schedule);
@@ -241,10 +243,10 @@ TEST(RPOLoop1) {
   BasicBlock* C = schedule.NewBasicBlock();
   BasicBlock* D = schedule.end();
 
-  schedule.AddSuccessor(A, B);
-  schedule.AddSuccessor(B, C);
-  schedule.AddSuccessor(C, B);
-  schedule.AddSuccessor(C, D);
+  schedule.AddSuccessorForTesting(A, B);
+  schedule.AddSuccessorForTesting(B, C);
+  schedule.AddSuccessorForTesting(C, B);
+  schedule.AddSuccessorForTesting(C, D);
 
   ZonePool zone_pool(scope.main_isolate());
   BasicBlockVector* order = Scheduler::ComputeSpecialRPO(&zone_pool, &schedule);
@@ -263,10 +265,10 @@ TEST(RPOLoop2) {
   BasicBlock* C = schedule.NewBasicBlock();
   BasicBlock* D = schedule.end();
 
-  schedule.AddSuccessor(A, B);
-  schedule.AddSuccessor(B, C);
-  schedule.AddSuccessor(C, B);
-  schedule.AddSuccessor(B, D);
+  schedule.AddSuccessorForTesting(A, B);
+  schedule.AddSuccessorForTesting(B, C);
+  schedule.AddSuccessorForTesting(C, B);
+  schedule.AddSuccessorForTesting(B, D);
 
   ZonePool zone_pool(scope.main_isolate());
   BasicBlockVector* order = Scheduler::ComputeSpecialRPO(&zone_pool, &schedule);
@@ -289,27 +291,27 @@ TEST(RPOLoopN) {
     BasicBlock* F = schedule.NewBasicBlock();
     BasicBlock* G = schedule.end();
 
-    schedule.AddSuccessor(A, B);
-    schedule.AddSuccessor(B, C);
-    schedule.AddSuccessor(C, D);
-    schedule.AddSuccessor(D, E);
-    schedule.AddSuccessor(E, F);
-    schedule.AddSuccessor(F, B);
-    schedule.AddSuccessor(B, G);
+    schedule.AddSuccessorForTesting(A, B);
+    schedule.AddSuccessorForTesting(B, C);
+    schedule.AddSuccessorForTesting(C, D);
+    schedule.AddSuccessorForTesting(D, E);
+    schedule.AddSuccessorForTesting(E, F);
+    schedule.AddSuccessorForTesting(F, B);
+    schedule.AddSuccessorForTesting(B, G);
 
     // Throw in extra backedges from time to time.
-    if (i == 1) schedule.AddSuccessor(B, B);
-    if (i == 2) schedule.AddSuccessor(C, B);
-    if (i == 3) schedule.AddSuccessor(D, B);
-    if (i == 4) schedule.AddSuccessor(E, B);
-    if (i == 5) schedule.AddSuccessor(F, B);
+    if (i == 1) schedule.AddSuccessorForTesting(B, B);
+    if (i == 2) schedule.AddSuccessorForTesting(C, B);
+    if (i == 3) schedule.AddSuccessorForTesting(D, B);
+    if (i == 4) schedule.AddSuccessorForTesting(E, B);
+    if (i == 5) schedule.AddSuccessorForTesting(F, B);
 
     // Throw in extra loop exits from time to time.
-    if (i == 6) schedule.AddSuccessor(B, G);
-    if (i == 7) schedule.AddSuccessor(C, G);
-    if (i == 8) schedule.AddSuccessor(D, G);
-    if (i == 9) schedule.AddSuccessor(E, G);
-    if (i == 10) schedule.AddSuccessor(F, G);
+    if (i == 6) schedule.AddSuccessorForTesting(B, G);
+    if (i == 7) schedule.AddSuccessorForTesting(C, G);
+    if (i == 8) schedule.AddSuccessorForTesting(D, G);
+    if (i == 9) schedule.AddSuccessorForTesting(E, G);
+    if (i == 10) schedule.AddSuccessorForTesting(F, G);
 
     ZonePool zone_pool(scope.main_isolate());
     BasicBlockVector* order =
@@ -332,13 +334,13 @@ TEST(RPOLoopNest1) {
   BasicBlock* E = schedule.NewBasicBlock();
   BasicBlock* F = schedule.end();
 
-  schedule.AddSuccessor(A, B);
-  schedule.AddSuccessor(B, C);
-  schedule.AddSuccessor(C, D);
-  schedule.AddSuccessor(D, C);
-  schedule.AddSuccessor(D, E);
-  schedule.AddSuccessor(E, B);
-  schedule.AddSuccessor(E, F);
+  schedule.AddSuccessorForTesting(A, B);
+  schedule.AddSuccessorForTesting(B, C);
+  schedule.AddSuccessorForTesting(C, D);
+  schedule.AddSuccessorForTesting(D, C);
+  schedule.AddSuccessorForTesting(D, E);
+  schedule.AddSuccessorForTesting(E, B);
+  schedule.AddSuccessorForTesting(E, F);
 
   ZonePool zone_pool(scope.main_isolate());
   BasicBlockVector* order = Scheduler::ComputeSpecialRPO(&zone_pool, &schedule);
@@ -364,17 +366,17 @@ TEST(RPOLoopNest2) {
   BasicBlock* G = schedule.NewBasicBlock();
   BasicBlock* H = schedule.end();
 
-  schedule.AddSuccessor(A, B);
-  schedule.AddSuccessor(B, C);
-  schedule.AddSuccessor(C, D);
-  schedule.AddSuccessor(D, E);
-  schedule.AddSuccessor(E, F);
-  schedule.AddSuccessor(F, G);
-  schedule.AddSuccessor(G, H);
+  schedule.AddSuccessorForTesting(A, B);
+  schedule.AddSuccessorForTesting(B, C);
+  schedule.AddSuccessorForTesting(C, D);
+  schedule.AddSuccessorForTesting(D, E);
+  schedule.AddSuccessorForTesting(E, F);
+  schedule.AddSuccessorForTesting(F, G);
+  schedule.AddSuccessorForTesting(G, H);
 
-  schedule.AddSuccessor(E, D);
-  schedule.AddSuccessor(F, C);
-  schedule.AddSuccessor(G, B);
+  schedule.AddSuccessorForTesting(E, D);
+  schedule.AddSuccessorForTesting(F, C);
+  schedule.AddSuccessorForTesting(G, B);
 
   ZonePool zone_pool(scope.main_isolate());
   BasicBlockVector* order = Scheduler::ComputeSpecialRPO(&zone_pool, &schedule);
@@ -400,9 +402,9 @@ TEST(RPOLoopFollow1) {
   BasicBlock* A = schedule.start();
   BasicBlock* E = schedule.end();
 
-  schedule.AddSuccessor(A, loop1->header());
-  schedule.AddSuccessor(loop1->header(), loop2->header());
-  schedule.AddSuccessor(loop2->last(), E);
+  schedule.AddSuccessorForTesting(A, loop1->header());
+  schedule.AddSuccessorForTesting(loop1->header(), loop2->header());
+  schedule.AddSuccessorForTesting(loop2->last(), E);
 
   ZonePool zone_pool(scope.main_isolate());
   BasicBlockVector* order = Scheduler::ComputeSpecialRPO(&zone_pool, &schedule);
@@ -427,10 +429,10 @@ TEST(RPOLoopFollow2) {
   BasicBlock* S = schedule.NewBasicBlock();
   BasicBlock* E = schedule.end();
 
-  schedule.AddSuccessor(A, loop1->header());
-  schedule.AddSuccessor(loop1->header(), S);
-  schedule.AddSuccessor(S, loop2->header());
-  schedule.AddSuccessor(loop2->last(), E);
+  schedule.AddSuccessorForTesting(A, loop1->header());
+  schedule.AddSuccessorForTesting(loop1->header(), S);
+  schedule.AddSuccessorForTesting(S, loop2->header());
+  schedule.AddSuccessorForTesting(loop2->last(), E);
 
   ZonePool zone_pool(scope.main_isolate());
   BasicBlockVector* order = Scheduler::ComputeSpecialRPO(&zone_pool, &schedule);
@@ -455,9 +457,9 @@ TEST(RPOLoopFollowN) {
       BasicBlock* A = schedule.start();
       BasicBlock* E = schedule.end();
 
-      schedule.AddSuccessor(A, loop1->header());
-      schedule.AddSuccessor(loop1->nodes[exit], loop2->header());
-      schedule.AddSuccessor(loop2->nodes[exit], E);
+      schedule.AddSuccessorForTesting(A, loop1->header());
+      schedule.AddSuccessorForTesting(loop1->nodes[exit], loop2->header());
+      schedule.AddSuccessorForTesting(loop2->nodes[exit], E);
       ZonePool zone_pool(scope.main_isolate());
       BasicBlockVector* order =
           Scheduler::ComputeSpecialRPO(&zone_pool, &schedule);
@@ -484,12 +486,12 @@ TEST(RPONestedLoopFollow1) {
   BasicBlock* C = schedule.NewBasicBlock();
   BasicBlock* E = schedule.end();
 
-  schedule.AddSuccessor(A, B);
-  schedule.AddSuccessor(B, loop1->header());
-  schedule.AddSuccessor(loop1->header(), loop2->header());
-  schedule.AddSuccessor(loop2->last(), C);
-  schedule.AddSuccessor(C, E);
-  schedule.AddSuccessor(C, B);
+  schedule.AddSuccessorForTesting(A, B);
+  schedule.AddSuccessorForTesting(B, loop1->header());
+  schedule.AddSuccessorForTesting(loop1->header(), loop2->header());
+  schedule.AddSuccessorForTesting(loop2->last(), C);
+  schedule.AddSuccessorForTesting(C, E);
+  schedule.AddSuccessorForTesting(C, B);
 
   ZonePool zone_pool(scope.main_isolate());
   BasicBlockVector* order = Scheduler::ComputeSpecialRPO(&zone_pool, &schedule);
@@ -517,11 +519,11 @@ TEST(RPOLoopBackedges1) {
       BasicBlock* E = schedule.end();
 
       SmartPointer<TestLoop> loop1(CreateLoop(&schedule, size));
-      schedule.AddSuccessor(A, loop1->header());
-      schedule.AddSuccessor(loop1->last(), E);
+      schedule.AddSuccessorForTesting(A, loop1->header());
+      schedule.AddSuccessorForTesting(loop1->last(), E);
 
-      schedule.AddSuccessor(loop1->nodes[i], loop1->header());
-      schedule.AddSuccessor(loop1->nodes[j], E);
+      schedule.AddSuccessorForTesting(loop1->nodes[i], loop1->header());
+      schedule.AddSuccessorForTesting(loop1->nodes[j], E);
 
       ZonePool zone_pool(scope.main_isolate());
       BasicBlockVector* order =
@@ -545,12 +547,12 @@ TEST(RPOLoopOutedges1) {
       BasicBlock* E = schedule.end();
 
       SmartPointer<TestLoop> loop1(CreateLoop(&schedule, size));
-      schedule.AddSuccessor(A, loop1->header());
-      schedule.AddSuccessor(loop1->last(), E);
+      schedule.AddSuccessorForTesting(A, loop1->header());
+      schedule.AddSuccessorForTesting(loop1->last(), E);
 
-      schedule.AddSuccessor(loop1->nodes[i], loop1->header());
-      schedule.AddSuccessor(loop1->nodes[j], D);
-      schedule.AddSuccessor(D, E);
+      schedule.AddSuccessorForTesting(loop1->nodes[i], loop1->header());
+      schedule.AddSuccessorForTesting(loop1->nodes[j], D);
+      schedule.AddSuccessorForTesting(D, E);
 
       ZonePool zone_pool(scope.main_isolate());
       BasicBlockVector* order =
@@ -572,13 +574,13 @@ TEST(RPOLoopOutedges2) {
     BasicBlock* E = schedule.end();
 
     SmartPointer<TestLoop> loop1(CreateLoop(&schedule, size));
-    schedule.AddSuccessor(A, loop1->header());
-    schedule.AddSuccessor(loop1->last(), E);
+    schedule.AddSuccessorForTesting(A, loop1->header());
+    schedule.AddSuccessorForTesting(loop1->last(), E);
 
     for (int j = 0; j < size; j++) {
       BasicBlock* O = schedule.NewBasicBlock();
-      schedule.AddSuccessor(loop1->nodes[j], O);
-      schedule.AddSuccessor(O, E);
+      schedule.AddSuccessorForTesting(loop1->nodes[j], O);
+      schedule.AddSuccessorForTesting(O, E);
     }
 
     ZonePool zone_pool(scope.main_isolate());
@@ -599,14 +601,14 @@ TEST(RPOLoopOutloops1) {
     BasicBlock* A = schedule.start();
     BasicBlock* E = schedule.end();
     SmartPointer<TestLoop> loop1(CreateLoop(&schedule, size));
-    schedule.AddSuccessor(A, loop1->header());
-    schedule.AddSuccessor(loop1->last(), E);
+    schedule.AddSuccessorForTesting(A, loop1->header());
+    schedule.AddSuccessorForTesting(loop1->last(), E);
 
     TestLoop** loopN = new TestLoop* [size];
     for (int j = 0; j < size; j++) {
       loopN[j] = CreateLoop(&schedule, 2);
-      schedule.AddSuccessor(loop1->nodes[j], loopN[j]->header());
-      schedule.AddSuccessor(loopN[j]->last(), E);
+      schedule.AddSuccessorForTesting(loop1->nodes[j], loopN[j]->header());
+      schedule.AddSuccessorForTesting(loopN[j]->last(), E);
     }
 
     ZonePool zone_pool(scope.main_isolate());
@@ -634,13 +636,13 @@ TEST(RPOLoopMultibackedge) {
   BasicBlock* D = schedule.end();
   BasicBlock* E = schedule.NewBasicBlock();
 
-  schedule.AddSuccessor(A, B);
-  schedule.AddSuccessor(B, C);
-  schedule.AddSuccessor(B, D);
-  schedule.AddSuccessor(B, E);
-  schedule.AddSuccessor(C, B);
-  schedule.AddSuccessor(D, B);
-  schedule.AddSuccessor(E, B);
+  schedule.AddSuccessorForTesting(A, B);
+  schedule.AddSuccessorForTesting(B, C);
+  schedule.AddSuccessorForTesting(B, D);
+  schedule.AddSuccessorForTesting(B, E);
+  schedule.AddSuccessorForTesting(C, B);
+  schedule.AddSuccessorForTesting(D, B);
+  schedule.AddSuccessorForTesting(E, B);
 
   ZonePool zone_pool(scope.main_isolate());
   BasicBlockVector* order = Scheduler::ComputeSpecialRPO(&zone_pool, &schedule);