Add Schedule::InsertBranch to fuse control flow graphs.

test/cctest/compiler/test-scheduler.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 #include "test/cctest/cctest.h"
 
 #include "src/compiler/access-builder.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/generic-node-inl.h"
@@ skipping 21 matching lines @@
   ~TestLoop() { delete[] nodes; }
 };
 
 
 static TestLoop* CreateLoop(Schedule* schedule, int count) {
   TestLoop* loop = new TestLoop();
   loop->count = 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;
 }
 
 
 static void CheckRPONumbers(BasicBlockVector* order, size_t expected,
                             bool loops_allowed) {
   CHECK(expected == order->size());
   for (int i = 0; i < static_cast<int>(order->size()); i++) {
     CHECK(order->at(i)->rpo_number() == i);
     if (!loops_allowed) CHECK_LT(order->at(i)->loop_end(), 0);
@@ skipping 98 matching lines @@
         CHECK(block->rpo_number() + 1 == block->SuccessorAt(0)->rpo_number());
       }
     }
   }
 }
 
 
 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);
   BasicBlock* loop[] = {schedule.start()};
   CheckLoopContains(loop, 1);
 }
 
 
 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);
   BasicBlock* loop[] = {schedule.start(), schedule.end()};
   CheckLoopContains(loop, 2);
 }
 
 
 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);
   CheckLoopContains(loop1->nodes, loop1->count);
 }
 
 
 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);
   CheckLoopContains(loop1->nodes, loop1->count);
 }
 
 
 TEST(RPODiamond) {
   HandleAndZoneScope scope;
   Schedule schedule(scope.main_zone());
 
   BasicBlock* A = schedule.start();
   BasicBlock* B = schedule.NewBasicBlock();
   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);
   CheckRPONumbers(order, 4, false);
 
   CHECK_EQ(0, A->rpo_number());
   CHECK((B->rpo_number() == 1 && C->rpo_number() == 2) ||
         (B->rpo_number() == 2 && C->rpo_number() == 1));
   CHECK_EQ(3, D->rpo_number());
 }
 
 
 TEST(RPOLoop1) {
   HandleAndZoneScope scope;
   Schedule schedule(scope.main_zone());
 
   BasicBlock* A = schedule.start();
   BasicBlock* B = schedule.NewBasicBlock();
   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);
   CheckRPONumbers(order, 4, true);
   BasicBlock* loop[] = {B, C};
   CheckLoopContains(loop, 2);
 }
 
 
 TEST(RPOLoop2) {
   HandleAndZoneScope scope;
   Schedule schedule(scope.main_zone());
 
   BasicBlock* A = schedule.start();
   BasicBlock* B = schedule.NewBasicBlock();
   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);
   CheckRPONumbers(order, 4, true);
   BasicBlock* loop[] = {B, C};
   CheckLoopContains(loop, 2);
 }
 
 
 TEST(RPOLoopN) {
   HandleAndZoneScope scope;
 
   for (int i = 0; i < 11; i++) {
     Schedule schedule(scope.main_zone());
     BasicBlock* A = schedule.start();
     BasicBlock* B = schedule.NewBasicBlock();
     BasicBlock* C = schedule.NewBasicBlock();
     BasicBlock* D = schedule.NewBasicBlock();
     BasicBlock* E = schedule.NewBasicBlock();
     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 =
         Scheduler::ComputeSpecialRPO(&zone_pool, &schedule);
     CheckRPONumbers(order, 7, true);
     BasicBlock* loop[] = {B, C, D, E, F};
     CheckLoopContains(loop, 5);
   }
 }
 
 
 TEST(RPOLoopNest1) {
   HandleAndZoneScope scope;
   Schedule schedule(scope.main_zone());
 
   BasicBlock* A = schedule.start();
   BasicBlock* B = schedule.NewBasicBlock();
   BasicBlock* C = schedule.NewBasicBlock();
   BasicBlock* D = schedule.NewBasicBlock();
   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);
   CheckRPONumbers(order, 6, true);
   BasicBlock* loop1[] = {B, C, D, E};
   CheckLoopContains(loop1, 4);
 
   BasicBlock* loop2[] = {C, D};
   CheckLoopContains(loop2, 2);
 }
 
 
 TEST(RPOLoopNest2) {
   HandleAndZoneScope scope;
   Schedule schedule(scope.main_zone());
 
   BasicBlock* A = schedule.start();
   BasicBlock* B = schedule.NewBasicBlock();
   BasicBlock* C = schedule.NewBasicBlock();
   BasicBlock* D = schedule.NewBasicBlock();
   BasicBlock* E = schedule.NewBasicBlock();
   BasicBlock* F = schedule.NewBasicBlock();
   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);
   CheckRPONumbers(order, 8, true);
   BasicBlock* loop1[] = {B, C, D, E, F, G};
   CheckLoopContains(loop1, 6);
 
   BasicBlock* loop2[] = {C, D, E, F};
   CheckLoopContains(loop2, 4);
 
   BasicBlock* loop3[] = {D, E};
   CheckLoopContains(loop3, 2);
 }
 
 
 TEST(RPOLoopFollow1) {
   HandleAndZoneScope scope;
   Schedule schedule(scope.main_zone());
 
   SmartPointer<TestLoop> loop1(CreateLoop(&schedule, 1));
   SmartPointer<TestLoop> loop2(CreateLoop(&schedule, 1));
 
   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);
 
   CheckLoopContains(loop1->nodes, loop1->count);
 
   CHECK_EQ(static_cast<int>(schedule.BasicBlockCount()),
            static_cast<int>(order->size()));
   CheckLoopContains(loop1->nodes, loop1->count);
   CheckLoopContains(loop2->nodes, loop2->count);
 }
 
 
 TEST(RPOLoopFollow2) {
   HandleAndZoneScope scope;
   Schedule schedule(scope.main_zone());
 
   SmartPointer<TestLoop> loop1(CreateLoop(&schedule, 1));
   SmartPointer<TestLoop> loop2(CreateLoop(&schedule, 1));
 
   BasicBlock* A = schedule.start();
   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);
 
   CheckLoopContains(loop1->nodes, loop1->count);
 
   CHECK_EQ(static_cast<int>(schedule.BasicBlockCount()),
            static_cast<int>(order->size()));
   CheckLoopContains(loop1->nodes, loop1->count);
   CheckLoopContains(loop2->nodes, loop2->count);
 }
 
 
 TEST(RPOLoopFollowN) {
   HandleAndZoneScope scope;
 
   for (int size = 1; size < 5; size++) {
     for (int exit = 0; exit < size; exit++) {
       Schedule schedule(scope.main_zone());
       SmartPointer<TestLoop> loop1(CreateLoop(&schedule, size));
       SmartPointer<TestLoop> loop2(CreateLoop(&schedule, size));
       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);
       CheckLoopContains(loop1->nodes, loop1->count);
 
       CHECK_EQ(static_cast<int>(schedule.BasicBlockCount()),
                static_cast<int>(order->size()));
       CheckLoopContains(loop1->nodes, loop1->count);
       CheckLoopContains(loop2->nodes, loop2->count);
     }
   }
 }
 
 
 TEST(RPONestedLoopFollow1) {
   HandleAndZoneScope scope;
   Schedule schedule(scope.main_zone());
 
   SmartPointer<TestLoop> loop1(CreateLoop(&schedule, 1));
   SmartPointer<TestLoop> loop2(CreateLoop(&schedule, 1));
 
   BasicBlock* A = schedule.start();
   BasicBlock* B = schedule.NewBasicBlock();
   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);
 
   CheckLoopContains(loop1->nodes, loop1->count);
 
   CHECK_EQ(static_cast<int>(schedule.BasicBlockCount()),
            static_cast<int>(order->size()));
   CheckLoopContains(loop1->nodes, loop1->count);
   CheckLoopContains(loop2->nodes, loop2->count);
 
   BasicBlock* loop3[] = {B, loop1->nodes[0], loop2->nodes[0], C};
   CheckLoopContains(loop3, 4);
 }
 
 
 TEST(RPOLoopBackedges1) {
   HandleAndZoneScope scope;
 
   int size = 8;
   for (int i = 0; i < size; i++) {
     for (int j = 0; j < size; j++) {
       Schedule schedule(scope.main_zone());
       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);
 
-      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 =
           Scheduler::ComputeSpecialRPO(&zone_pool, &schedule);
       CheckRPONumbers(order, schedule.BasicBlockCount(), true);
       CheckLoopContains(loop1->nodes, loop1->count);
     }
   }
 }
 
 
 TEST(RPOLoopOutedges1) {
   HandleAndZoneScope scope;
 
   int size = 8;
   for (int i = 0; i < size; i++) {
     for (int j = 0; j < size; j++) {
       Schedule schedule(scope.main_zone());
       BasicBlock* A = schedule.start();
       BasicBlock* D = schedule.NewBasicBlock();
       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 =
           Scheduler::ComputeSpecialRPO(&zone_pool, &schedule);
       CheckRPONumbers(order, schedule.BasicBlockCount(), true);
       CheckLoopContains(loop1->nodes, loop1->count);
     }
   }
 }
 
 
 TEST(RPOLoopOutedges2) {
   HandleAndZoneScope scope;
 
   int size = 8;
   for (int i = 0; i < size; i++) {
     Schedule schedule(scope.main_zone());
     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);
 
     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());
     BasicBlockVector* order =
         Scheduler::ComputeSpecialRPO(&zone_pool, &schedule);
     CheckRPONumbers(order, schedule.BasicBlockCount(), true);
     CheckLoopContains(loop1->nodes, loop1->count);
   }
 }
 
 
 TEST(RPOLoopOutloops1) {
   HandleAndZoneScope scope;
 
   int size = 8;
   for (int i = 0; i < size; i++) {
     Schedule schedule(scope.main_zone());
     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());
     BasicBlockVector* order =
         Scheduler::ComputeSpecialRPO(&zone_pool, &schedule);
     CheckRPONumbers(order, schedule.BasicBlockCount(), true);
     CheckLoopContains(loop1->nodes, loop1->count);
 
     for (int j = 0; j < size; j++) {
       CheckLoopContains(loopN[j]->nodes, loopN[j]->count);
       delete loopN[j];
     }
     delete[] loopN;
   }
 }
 
 
 TEST(RPOLoopMultibackedge) {
   HandleAndZoneScope scope;
   Schedule schedule(scope.main_zone());
 
   BasicBlock* A = schedule.start();
   BasicBlock* B = schedule.NewBasicBlock();
   BasicBlock* C = schedule.NewBasicBlock();
   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);
   CheckRPONumbers(order, 5, true);
 
   BasicBlock* loop1[] = {B, C, D, E};
   CheckLoopContains(loop1, 4);
 }
 
 
@@ skipping 1255 matching lines @@
   graph.SetEnd(end);
 
   Schedule* schedule = ComputeAndVerifySchedule(5, &graph);
   BasicBlock* block = schedule->block(loop);
   CHECK_NE(NULL, loop);
   CHECK_EQ(block, schedule->block(effect));
   CHECK_GE(block->rpo_number(), 0);
 }
 
 #endif