[turbofan] Fix control reducer for dead loops.

test/cctest/compiler/test-osr.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/codegen.h"
+#include "src/compiler/all-nodes.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/diamond.h"
 #include "src/compiler/graph.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/js-operator.h"
 #include "src/compiler/operator.h"
 #include "src/compiler/osr.h"
 #include "test/cctest/cctest.h"
 
 using namespace v8::internal;
@@ skipping 89 matching lines @@
     for (int i = 0; i < loop->InputCount(); i++) {
       if (loop->InputAt(i) == self) loop->ReplaceInput(i, loop);
     }
 
     return loop;
   }
 
   Node* NewOsrLoop(int num_backedges, Node* entry = NULL) {
     return NewLoop(true, num_backedges, entry);
   }
+
+  void DeconstructOsr() {
+    OsrHelper helper(0, 0);
+    helper.Deconstruct(&jsgraph, &common, main_zone());
+    AllNodes nodes(main_zone(), &graph);
+    // Should be edited out.
+    CHECK(!nodes.IsLive(osr_normal_entry));
+    CHECK(!nodes.IsLive(osr_loop_entry));
+    // No dangling nodes should be left over.
+    CHECK_EQ(0u, nodes.gray.size());
+  }
 };
 
 
 TEST(Deconstruct_osr0) {
   OsrDeconstructorTester T(0);
 
   Node* loop = T.NewOsrLoop(1);
 
   T.graph.SetEnd(loop);
 
-  OsrHelper helper(0, 0);
-  helper.Deconstruct(&T.jsgraph, &T.common, T.main_zone());
+  T.DeconstructOsr();
 
   CheckInputs(loop, T.start, loop);
 }
 
 
 TEST(Deconstruct_osr1) {
   OsrDeconstructorTester T(1);
 
   Node* loop = T.NewOsrLoop(1);
   Node* osr_phi =
       T.NewOsrPhi(loop, T.jsgraph.OneConstant(), 0, T.jsgraph.ZeroConstant());
 
   Node* ret = T.graph.NewNode(T.common.Return(), osr_phi, T.start, loop);
   T.graph.SetEnd(ret);
 
-  OsrHelper helper(0, 0);
-  helper.Deconstruct(&T.jsgraph, &T.common, T.main_zone());
+  T.DeconstructOsr();
 
   CheckInputs(loop, T.start, loop);
   CheckInputs(osr_phi, T.osr_values[0], T.jsgraph.ZeroConstant(), loop);
   CheckInputs(ret, osr_phi, T.start, loop);
 }
 
 
 TEST(Deconstruct_osr_remove_prologue) {
   OsrDeconstructorTester T(1);
   Diamond d(&T.graph, &T.common, T.p0);
   d.Chain(T.osr_normal_entry);
 
   Node* loop = T.NewOsrLoop(1, d.merge);
   Node* osr_phi =
       T.NewOsrPhi(loop, T.jsgraph.OneConstant(), 0, T.jsgraph.ZeroConstant());
 
   Node* ret = T.graph.NewNode(T.common.Return(), osr_phi, T.start, loop);
   T.graph.SetEnd(ret);
 
-  OsrHelper helper(0, 0);
-  helper.Deconstruct(&T.jsgraph, &T.common, T.main_zone());
+  T.DeconstructOsr();
 
   CheckInputs(loop, T.start, loop);
   CheckInputs(osr_phi, T.osr_values[0], T.jsgraph.ZeroConstant(), loop);
   CheckInputs(ret, osr_phi, T.start, loop);
 
   // The control before the loop should have been removed.
-  CHECK(d.branch->IsDead());
-  CHECK(d.if_true->IsDead());
-  CHECK(d.if_false->IsDead());
-  CHECK(d.merge->IsDead());
+  AllNodes nodes(T.main_zone(), &T.graph);
+  CHECK(!nodes.IsLive(d.branch));
+  CHECK(!nodes.IsLive(d.if_true));
+  CHECK(!nodes.IsLive(d.if_false));
+  CHECK(!nodes.IsLive(d.merge));
 }
 
 
 TEST(Deconstruct_osr_with_body1) {
   OsrDeconstructorTester T(1);
 
   Node* loop = T.NewOsrLoop(1);
 
   Node* branch = T.graph.NewNode(T.common.Branch(), T.p0, loop);
   Node* if_true = T.graph.NewNode(T.common.IfTrue(), branch);
   Node* if_false = T.graph.NewNode(T.common.IfFalse(), branch);
   loop->ReplaceInput(2, if_true);
 
   Node* osr_phi =
       T.NewOsrPhi(loop, T.jsgraph.OneConstant(), 0, T.jsgraph.ZeroConstant());
 
   Node* ret = T.graph.NewNode(T.common.Return(), osr_phi, T.start, if_false);
   T.graph.SetEnd(ret);
 
-  OsrHelper helper(0, 0);
-  helper.Deconstruct(&T.jsgraph, &T.common, T.main_zone());
+  T.DeconstructOsr();
 
   CheckInputs(loop, T.start, if_true);
   CheckInputs(branch, T.p0, loop);
   CheckInputs(if_true, branch);
   CheckInputs(if_false, branch);
   CheckInputs(osr_phi, T.osr_values[0], T.jsgraph.ZeroConstant(), loop);
   CheckInputs(ret, osr_phi, T.start, if_false);
 }
 
 
@@ skipping 12 matching lines @@
   Node* if_false2 = T.graph.NewNode(T.common.IfFalse(), branch2);
   loop->ReplaceInput(2, if_true2);
 
   Node* osr_phi =
       T.NewOsrPhi(loop, T.jsgraph.OneConstant(), 0, T.jsgraph.ZeroConstant());
 
   Node* merge = T.graph.NewNode(T.common.Merge(2), if_false1, if_false2);
   Node* ret = T.graph.NewNode(T.common.Return(), osr_phi, T.start, merge);
   T.graph.SetEnd(ret);
 
-  OsrHelper helper(0, 0);
-  helper.Deconstruct(&T.jsgraph, &T.common, T.main_zone());
+  T.DeconstructOsr();
 
   CheckInputs(loop, T.start, if_true2);
   CheckInputs(branch1, T.p0, loop);
   CheckInputs(branch2, T.p0, if_true1);
   CheckInputs(if_true1, branch1);
   CheckInputs(if_false1, branch1);
   CheckInputs(if_true2, branch2);
   CheckInputs(if_false2, branch2);
 
   CheckInputs(osr_phi, T.osr_values[0], T.jsgraph.ZeroConstant(), loop);
@@ skipping 18 matching lines @@
   loop->ReplaceInput(2, if_false1);
   loop->ReplaceInput(3, if_true2);
 
   Node* osr_phi =
       T.NewOsrPhi(loop, T.jsgraph.OneConstant(), 0, T.jsgraph.ZeroConstant(),
                   T.jsgraph.ZeroConstant());
 
   Node* ret = T.graph.NewNode(T.common.Return(), osr_phi, T.start, if_false2);
   T.graph.SetEnd(ret);
 
-  OsrHelper helper(0, 0);
-  helper.Deconstruct(&T.jsgraph, &T.common, T.main_zone());
+  T.DeconstructOsr();
 
   CheckInputs(loop, T.start, if_false1, if_true2);
   CheckInputs(branch1, T.p0, loop);
   CheckInputs(branch2, T.p0, if_true1);
   CheckInputs(if_true1, branch1);
   CheckInputs(if_false1, branch1);
   CheckInputs(if_true2, branch2);
   CheckInputs(if_false2, branch2);
 
   CheckInputs(osr_phi, T.osr_values[0], T.jsgraph.ZeroConstant(),
@@ skipping 55 matching lines @@
   Node* osr_phi = inner.Phi(T.jsgraph.OneConstant(), T.osr_values[0],
                             T.jsgraph.ZeroConstant());
   inner.branch->ReplaceInput(0, osr_phi);
   outer_phi->ReplaceInput(1, osr_phi);
 
   Node* ret =
       T.graph.NewNode(T.common.Return(), outer_phi, T.start, outer.exit);
   Node* end = T.graph.NewNode(T.common.End(), ret);
   T.graph.SetEnd(end);
 
-  OsrHelper helper(0, 0);
-  helper.Deconstruct(&T.jsgraph, &T.common, T.main_zone());
+  T.DeconstructOsr();
 
   // Check structure of deconstructed graph.
   // Check inner OSR loop is directly connected to start.
   CheckInputs(inner.loop, T.start, inner.if_true);
   CheckInputs(osr_phi, T.osr_values[0], T.jsgraph.ZeroConstant(), inner.loop);
 
   // Check control transfer to copy of outer loop.
   Node* new_outer_loop = FindSuccessor(inner.exit, IrOpcode::kLoop);
   Node* new_outer_phi = FindSuccessor(new_outer_loop, IrOpcode::kPhi);
   CHECK_NE(new_outer_loop, outer.loop);
@@ skipping 46 matching lines @@
   Node* x_false = T.graph.NewNode(T.common.IfFalse(), x_branch);
 
   outer.loop->ReplaceInput(1, x_true);
   outer.loop->ReplaceInput(2, x_false);
 
   Node* ret =
       T.graph.NewNode(T.common.Return(), outer_phi, T.start, outer.exit);
   Node* end = T.graph.NewNode(T.common.End(), ret);
   T.graph.SetEnd(end);
 
-  OsrHelper helper(0, 0);
-  helper.Deconstruct(&T.jsgraph, &T.common, T.main_zone());
+  T.DeconstructOsr();
 
   // Check structure of deconstructed graph.
   // Check inner OSR loop is directly connected to start.
   CheckInputs(inner.loop, T.start, inner.if_true);
   CheckInputs(osr_phi, T.osr_values[0], T.jsgraph.ZeroConstant(), inner.loop);
 
   // Check control transfer to copy of outer loop.
   Node* new_merge = FindSuccessor(x_true, IrOpcode::kMerge);
   CHECK_EQ(new_merge, FindSuccessor(x_false, IrOpcode::kMerge));
   CheckInputs(new_merge, x_true, x_false);
@@ skipping 23 matching lines @@
 
   // Check structure of inner loop.
   Node* new_inner_loop = FindSuccessor(new_outer_if_true, IrOpcode::kLoop);
   Node* new_inner_phi = FindSuccessor(new_inner_loop, IrOpcode::kPhi);
 
   CheckInputs(new_inner_phi, T.jsgraph.OneConstant(), T.jsgraph.ZeroConstant(),
               new_inner_loop);
   CheckInputs(new_outer_phi, new_entry_phi, new_inner_phi,
               T.jsgraph.ZeroConstant(), new_outer_loop);
 }