Move RPO unittests into their own file.

test/unittests/compiler/scheduler-rpo-unittest.cc

+// Copyright 2015 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/compiler/schedule.h"
+#include "src/compiler/scheduler.h"
+#include "test/unittests/compiler/compiler-test-utils.h"
+#include "test/unittests/test-utils.h"
+#include "testing/gmock/include/gmock/gmock.h"
+
+using testing::AnyOf;
+
+namespace v8 {
+namespace internal {
+namespace compiler {
+
+class SchedulerRPOTest : public TestWithZone {
+ public:
+  SchedulerRPOTest() {}
+
+  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(!order->at(i)->loop_end());
+        CHECK(!order->at(i)->loop_header());
+      }
+    }
+  }
+
+  void CheckLoop(BasicBlockVector* order, BasicBlock** blocks, int body_size) {
+    BasicBlock* header = blocks[0];
+    BasicBlock* end = header->loop_end();
+    CHECK(end);
+    CHECK_GT(end->rpo_number(), 0);
+    CHECK_EQ(body_size, end->rpo_number() - header->rpo_number());
+    for (int i = 0; i < body_size; i++) {
+      CHECK_GE(blocks[i]->rpo_number(), header->rpo_number());
+      CHECK_LT(blocks[i]->rpo_number(), end->rpo_number());
+      CHECK(header->LoopContains(blocks[i]));
+      CHECK(header->IsLoopHeader() || blocks[i]->loop_header() == header);
+    }
+    if (header->rpo_number() > 0) {
+      CHECK_NE(order->at(header->rpo_number() - 1)->loop_header(), header);
+    }
+    if (end->rpo_number() < static_cast<int>(order->size())) {
+      CHECK_NE(order->at(end->rpo_number())->loop_header(), header);
+    }
+  }
+
+  struct TestLoop {
+    int count;
+    BasicBlock** nodes;
+    BasicBlock* header() { return nodes[0]; }
+    BasicBlock* last() { return nodes[count - 1]; }
+    ~TestLoop() { delete[] nodes; }
+  };
+
+  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->AddSuccessorForTesting(loop->nodes[i - 1], loop->nodes[i]);
+      }
+    }
+    schedule->AddSuccessorForTesting(loop->nodes[count - 1], loop->nodes[0]);
+    return loop;
+  }
+};
+
+TEST_F(SchedulerRPOTest, Degenerate1) {
+  Schedule schedule(zone());
+  BasicBlockVector* order = Scheduler::ComputeSpecialRPO(zone(), &schedule);
+  CheckRPONumbers(order, 1, false);
+  EXPECT_EQ(schedule.start(), order->at(0));
+}
+
+TEST_F(SchedulerRPOTest, Degenerate2) {
+  Schedule schedule(zone());
+
+  schedule.AddGoto(schedule.start(), schedule.end());
+  BasicBlockVector* order = Scheduler::ComputeSpecialRPO(zone(), &schedule);
+  CheckRPONumbers(order, 2, false);
+  EXPECT_EQ(schedule.start(), order->at(0));
+  EXPECT_EQ(schedule.end(), order->at(1));
+}
+
+TEST_F(SchedulerRPOTest, Line) {
+  for (int i = 0; i < 10; i++) {
+    Schedule schedule(zone());
+
+    BasicBlock* last = schedule.start();
+    for (int j = 0; j < i; j++) {
+      BasicBlock* block = schedule.NewBasicBlock();
+      block->set_deferred(i & 1);
+      schedule.AddGoto(last, block);
+      last = block;
+    }
+    BasicBlockVector* order = Scheduler::ComputeSpecialRPO(zone(), &schedule);
+    CheckRPONumbers(order, 1 + i, false);
+
+    for (size_t i = 0; i < schedule.BasicBlockCount(); i++) {
+      BasicBlock* block = schedule.GetBlockById(BasicBlock::Id::FromSize(i));
+      if (block->rpo_number() >= 0 && block->SuccessorCount() == 1) {
+        EXPECT_EQ(block->rpo_number() + 1, block->SuccessorAt(0)->rpo_number());
+      }
+    }
+  }
+}
+
+TEST_F(SchedulerRPOTest, SelfLoop) {
+  Schedule schedule(zone());
+  schedule.AddSuccessorForTesting(schedule.start(), schedule.start());
+  BasicBlockVector* order = Scheduler::ComputeSpecialRPO(zone(), &schedule);
+  CheckRPONumbers(order, 1, true);
+  BasicBlock* loop[] = {schedule.start()};
+  CheckLoop(order, loop, 1);
+}
+
+TEST_F(SchedulerRPOTest, EntryLoop) {
+  Schedule schedule(zone());
+  BasicBlock* body = schedule.NewBasicBlock();
+  schedule.AddSuccessorForTesting(schedule.start(), body);
+  schedule.AddSuccessorForTesting(body, schedule.start());
+  BasicBlockVector* order = Scheduler::ComputeSpecialRPO(zone(), &schedule);
+  CheckRPONumbers(order, 2, true);
+  BasicBlock* loop[] = {schedule.start(), body};
+  CheckLoop(order, loop, 2);
+}
+
+TEST_F(SchedulerRPOTest, EndLoop) {
+  Schedule schedule(zone());
+  base::SmartPointer<TestLoop> loop1(CreateLoop(&schedule, 2));
+  schedule.AddSuccessorForTesting(schedule.start(), loop1->header());
+  BasicBlockVector* order = Scheduler::ComputeSpecialRPO(zone(), &schedule);
+  CheckRPONumbers(order, 3, true);
+  CheckLoop(order, loop1->nodes, loop1->count);
+}
+
+TEST_F(SchedulerRPOTest, EndLoopNested) {
+  Schedule schedule(zone());
+  base::SmartPointer<TestLoop> loop1(CreateLoop(&schedule, 2));
+  schedule.AddSuccessorForTesting(schedule.start(), loop1->header());
+  schedule.AddSuccessorForTesting(loop1->last(), schedule.start());
+  BasicBlockVector* order = Scheduler::ComputeSpecialRPO(zone(), &schedule);
+  CheckRPONumbers(order, 3, true);
+  CheckLoop(order, loop1->nodes, loop1->count);
+}
+
+TEST_F(SchedulerRPOTest, Diamond) {
+  Schedule schedule(zone());
+
+  BasicBlock* A = schedule.start();
+  BasicBlock* B = schedule.NewBasicBlock();
+  BasicBlock* C = schedule.NewBasicBlock();
+  BasicBlock* D = schedule.end();
+
+  schedule.AddSuccessorForTesting(A, B);
+  schedule.AddSuccessorForTesting(A, C);
+  schedule.AddSuccessorForTesting(B, D);
+  schedule.AddSuccessorForTesting(C, D);
+
+  BasicBlockVector* order = Scheduler::ComputeSpecialRPO(zone(), &schedule);
+  CheckRPONumbers(order, 4, false);
+
+  EXPECT_EQ(0, A->rpo_number());
+  EXPECT_THAT(B->rpo_number(), AnyOf(1, 2));
+  EXPECT_THAT(C->rpo_number(), AnyOf(1, 2));
+  EXPECT_EQ(3, D->rpo_number());
+}
+
+TEST_F(SchedulerRPOTest, Loop1) {
+  Schedule schedule(zone());
+
+  BasicBlock* A = schedule.start();
+  BasicBlock* B = schedule.NewBasicBlock();
+  BasicBlock* C = schedule.NewBasicBlock();
+  BasicBlock* D = schedule.end();
+
+  schedule.AddSuccessorForTesting(A, B);
+  schedule.AddSuccessorForTesting(B, C);
+  schedule.AddSuccessorForTesting(C, B);
+  schedule.AddSuccessorForTesting(C, D);
+
+  BasicBlockVector* order = Scheduler::ComputeSpecialRPO(zone(), &schedule);
+  CheckRPONumbers(order, 4, true);
+  BasicBlock* loop[] = {B, C};
+  CheckLoop(order, loop, 2);
+}
+
+TEST_F(SchedulerRPOTest, Loop2) {
+  Schedule schedule(zone());
+
+  BasicBlock* A = schedule.start();
+  BasicBlock* B = schedule.NewBasicBlock();
+  BasicBlock* C = schedule.NewBasicBlock();
+  BasicBlock* D = schedule.end();
+
+  schedule.AddSuccessorForTesting(A, B);
+  schedule.AddSuccessorForTesting(B, C);
+  schedule.AddSuccessorForTesting(C, B);
+  schedule.AddSuccessorForTesting(B, D);
+
+  BasicBlockVector* order = Scheduler::ComputeSpecialRPO(zone(), &schedule);
+  CheckRPONumbers(order, 4, true);
+  BasicBlock* loop[] = {B, C};
+  CheckLoop(order, loop, 2);
+}
+
+TEST_F(SchedulerRPOTest, LoopN) {
+  for (int i = 0; i < 11; i++) {
+    Schedule schedule(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.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.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.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);
+
+    BasicBlockVector* order = Scheduler::ComputeSpecialRPO(zone(), &schedule);
+    CheckRPONumbers(order, 7, true);
+    BasicBlock* loop[] = {B, C, D, E, F};
+    CheckLoop(order, loop, 5);
+  }
+}
+
+TEST_F(SchedulerRPOTest, LoopNest1) {
+  Schedule schedule(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.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);
+
+  BasicBlockVector* order = Scheduler::ComputeSpecialRPO(zone(), &schedule);
+  CheckRPONumbers(order, 6, true);
+  BasicBlock* loop1[] = {B, C, D, E};
+  CheckLoop(order, loop1, 4);
+
+  BasicBlock* loop2[] = {C, D};
+  CheckLoop(order, loop2, 2);
+}
+
+TEST_F(SchedulerRPOTest, LoopNest2) {
+  Schedule schedule(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.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.AddSuccessorForTesting(E, D);
+  schedule.AddSuccessorForTesting(F, C);
+  schedule.AddSuccessorForTesting(G, B);
+
+  BasicBlockVector* order = Scheduler::ComputeSpecialRPO(zone(), &schedule);
+  CheckRPONumbers(order, 8, true);
+  BasicBlock* loop1[] = {B, C, D, E, F, G};
+  CheckLoop(order, loop1, 6);
+
+  BasicBlock* loop2[] = {C, D, E, F};
+  CheckLoop(order, loop2, 4);
+
+  BasicBlock* loop3[] = {D, E};
+  CheckLoop(order, loop3, 2);
+}
+
+TEST_F(SchedulerRPOTest, LoopFollow1) {
+  Schedule schedule(zone());
+
+  base::SmartPointer<TestLoop> loop1(CreateLoop(&schedule, 1));
+  base::SmartPointer<TestLoop> loop2(CreateLoop(&schedule, 1));
+
+  BasicBlock* A = schedule.start();
+  BasicBlock* E = schedule.end();
+
+  schedule.AddSuccessorForTesting(A, loop1->header());
+  schedule.AddSuccessorForTesting(loop1->header(), loop2->header());
+  schedule.AddSuccessorForTesting(loop2->last(), E);
+
+  BasicBlockVector* order = Scheduler::ComputeSpecialRPO(zone(), &schedule);
+
+  EXPECT_EQ(schedule.BasicBlockCount(), order->size());
+  CheckLoop(order, loop1->nodes, loop1->count);
+  CheckLoop(order, loop2->nodes, loop2->count);
+}
+
+TEST_F(SchedulerRPOTest, LoopFollow2) {
+  Schedule schedule(zone());
+
+  base::SmartPointer<TestLoop> loop1(CreateLoop(&schedule, 1));
+  base::SmartPointer<TestLoop> loop2(CreateLoop(&schedule, 1));
+
+  BasicBlock* A = schedule.start();
+  BasicBlock* S = schedule.NewBasicBlock();
+  BasicBlock* E = schedule.end();
+
+  schedule.AddSuccessorForTesting(A, loop1->header());
+  schedule.AddSuccessorForTesting(loop1->header(), S);
+  schedule.AddSuccessorForTesting(S, loop2->header());
+  schedule.AddSuccessorForTesting(loop2->last(), E);
+
+  BasicBlockVector* order = Scheduler::ComputeSpecialRPO(zone(), &schedule);
+
+  EXPECT_EQ(schedule.BasicBlockCount(), order->size());
+  CheckLoop(order, loop1->nodes, loop1->count);
+  CheckLoop(order, loop2->nodes, loop2->count);
+}
+
+TEST_F(SchedulerRPOTest, LoopFollowN) {
+  for (int size = 1; size < 5; size++) {
+    for (int exit = 0; exit < size; exit++) {
+      Schedule schedule(zone());
+      base::SmartPointer<TestLoop> loop1(CreateLoop(&schedule, size));
+      base::SmartPointer<TestLoop> loop2(CreateLoop(&schedule, size));
+      BasicBlock* A = schedule.start();
+      BasicBlock* E = schedule.end();
+
+      schedule.AddSuccessorForTesting(A, loop1->header());
+      schedule.AddSuccessorForTesting(loop1->nodes[exit], loop2->header());
+      schedule.AddSuccessorForTesting(loop2->nodes[exit], E);
+      BasicBlockVector* order = Scheduler::ComputeSpecialRPO(zone(), &schedule);
+
+      EXPECT_EQ(schedule.BasicBlockCount(), order->size());
+      CheckLoop(order, loop1->nodes, loop1->count);
+      CheckLoop(order, loop2->nodes, loop2->count);
+    }
+  }
+}
+
+TEST_F(SchedulerRPOTest, NestedLoopFollow1) {
+  Schedule schedule(zone());
+
+  base::SmartPointer<TestLoop> loop1(CreateLoop(&schedule, 1));
+  base::SmartPointer<TestLoop> loop2(CreateLoop(&schedule, 1));
+
+  BasicBlock* A = schedule.start();
+  BasicBlock* B = schedule.NewBasicBlock();
+  BasicBlock* C = schedule.NewBasicBlock();
+  BasicBlock* E = schedule.end();
+
+  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);
+
+  BasicBlockVector* order = Scheduler::ComputeSpecialRPO(zone(), &schedule);
+
+  EXPECT_EQ(schedule.BasicBlockCount(), order->size());
+  CheckLoop(order, loop1->nodes, loop1->count);
+  CheckLoop(order, loop2->nodes, loop2->count);
+
+  BasicBlock* loop3[] = {B, loop1->nodes[0], loop2->nodes[0], C};
+  CheckLoop(order, loop3, 4);
+}
+
+TEST_F(SchedulerRPOTest, LoopBackedges1) {
+  int size = 8;
+  for (int i = 0; i < size; i++) {
+    for (int j = 0; j < size; j++) {
+      Schedule schedule(zone());
+      BasicBlock* A = schedule.start();
+      BasicBlock* E = schedule.end();
+
+      base::SmartPointer<TestLoop> loop1(CreateLoop(&schedule, size));
+      schedule.AddSuccessorForTesting(A, loop1->header());
+      schedule.AddSuccessorForTesting(loop1->last(), E);
+
+      schedule.AddSuccessorForTesting(loop1->nodes[i], loop1->header());
+      schedule.AddSuccessorForTesting(loop1->nodes[j], E);
+
+      BasicBlockVector* order = Scheduler::ComputeSpecialRPO(zone(), &schedule);
+      CheckRPONumbers(order, schedule.BasicBlockCount(), true);
+      CheckLoop(order, loop1->nodes, loop1->count);
+    }
+  }
+}
+
+TEST_F(SchedulerRPOTest, LoopOutedges1) {
+  int size = 8;
+  for (int i = 0; i < size; i++) {
+    for (int j = 0; j < size; j++) {
+      Schedule schedule(zone());
+      BasicBlock* A = schedule.start();
+      BasicBlock* D = schedule.NewBasicBlock();
+      BasicBlock* E = schedule.end();
+
+      base::SmartPointer<TestLoop> loop1(CreateLoop(&schedule, size));
+      schedule.AddSuccessorForTesting(A, loop1->header());
+      schedule.AddSuccessorForTesting(loop1->last(), E);
+
+      schedule.AddSuccessorForTesting(loop1->nodes[i], loop1->header());
+      schedule.AddSuccessorForTesting(loop1->nodes[j], D);
+      schedule.AddSuccessorForTesting(D, E);
+
+      BasicBlockVector* order = Scheduler::ComputeSpecialRPO(zone(), &schedule);
+      CheckRPONumbers(order, schedule.BasicBlockCount(), true);
+      CheckLoop(order, loop1->nodes, loop1->count);
+    }
+  }
+}
+
+TEST_F(SchedulerRPOTest, LoopOutedges2) {
+  int size = 8;
+  for (int i = 0; i < size; i++) {
+    Schedule schedule(zone());
+    BasicBlock* A = schedule.start();
+    BasicBlock* E = schedule.end();
+
+    base::SmartPointer<TestLoop> loop1(CreateLoop(&schedule, size));
+    schedule.AddSuccessorForTesting(A, loop1->header());
+    schedule.AddSuccessorForTesting(loop1->last(), E);
+
+    for (int j = 0; j < size; j++) {
+      BasicBlock* O = schedule.NewBasicBlock();
+      schedule.AddSuccessorForTesting(loop1->nodes[j], O);
+      schedule.AddSuccessorForTesting(O, E);
+    }
+
+    BasicBlockVector* order = Scheduler::ComputeSpecialRPO(zone(), &schedule);
+    CheckRPONumbers(order, schedule.BasicBlockCount(), true);
+    CheckLoop(order, loop1->nodes, loop1->count);
+  }
+}
+
+TEST_F(SchedulerRPOTest, LoopOutloops1) {
+  int size = 8;
+  for (int i = 0; i < size; i++) {
+    Schedule schedule(zone());
+    BasicBlock* A = schedule.start();
+    BasicBlock* E = schedule.end();
+    base::SmartPointer<TestLoop> loop1(CreateLoop(&schedule, size));
+    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.AddSuccessorForTesting(loop1->nodes[j], loopN[j]->header());
+      schedule.AddSuccessorForTesting(loopN[j]->last(), E);
+    }
+
+    BasicBlockVector* order = Scheduler::ComputeSpecialRPO(zone(), &schedule);
+    CheckRPONumbers(order, schedule.BasicBlockCount(), true);
+    CheckLoop(order, loop1->nodes, loop1->count);
+
+    for (int j = 0; j < size; j++) {
+      CheckLoop(order, loopN[j]->nodes, loopN[j]->count);
+      delete loopN[j];
+    }
+    delete[] loopN;
+  }
+}
+
+TEST_F(SchedulerRPOTest, LoopMultibackedge) {
+  Schedule schedule(zone());
+
+  BasicBlock* A = schedule.start();
+  BasicBlock* B = schedule.NewBasicBlock();
+  BasicBlock* C = schedule.NewBasicBlock();
+  BasicBlock* D = schedule.NewBasicBlock();
+  BasicBlock* E = schedule.NewBasicBlock();
+
+  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);
+
+  BasicBlockVector* order = Scheduler::ComputeSpecialRPO(zone(), &schedule);
+  CheckRPONumbers(order, 5, true);
+
+  BasicBlock* loop1[] = {B, C, D, E};
+  CheckLoop(order, loop1, 4);
+}
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8