[turbofan] Move graph trimming functionality to dedicated GraphTrimmer.

test/cctest/compiler/test-control-reducer.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/base/bits.h"
 #include "src/compiler/all-nodes.h"
 #include "src/compiler/common-operator.h"
@@ skipping 123 matching lines @@
     for (Edge edge : node->input_edges()) {
       if (edge.to() == self) node->ReplaceInput(edge.index(), node);
     }
     return node;
   }
 
   const Operator* op(int count, bool effect) {
     return effect ? common.EffectPhi(count) : common.Phi(kMachAnyTagged, count);
   }
 
-  void Trim() { ControlReducer::TrimGraph(main_zone(), &jsgraph); }
-
   void ReduceGraph() { ControlReducer::ReduceGraph(main_zone(), &jsgraph); }
 
   // Checks one-step reduction of a phi.
   void ReducePhi(Node* expect, Node* phi) {
     Node* result = ControlReducer::ReducePhiForTesting(&jsgraph, phi);
     CHECK_EQ(expect, result);
     ReducePhiIterative(expect, phi);  // iterative should give the same result.
   }
 
   // Checks one-step reduction of a phi.
@@ skipping 148 matching lines @@
         CHECK_EQ(3, d.phi->InputCount());
         CHECK_EQ(d.merge, d.phi->InputAt(2));
       } else {
         Check(d.phi);
       }
     }
   }
 };
 
 
-TEST(Trim1_live) {
-  ControlReducerTester T;
-  CHECK(IsUsedBy(T.start, T.p0));
-  T.graph.SetEnd(T.p0);
-  T.Trim();
-  CHECK(IsUsedBy(T.start, T.p0));
-  CheckInputs(T.p0, T.start);
-}
-
-
-TEST(Trim1_dead) {
-  ControlReducerTester T;
-  CHECK(IsUsedBy(T.start, T.p0));
-  T.Trim();
-  CHECK(!IsUsedBy(T.start, T.p0));
-  CHECK(!T.p0->InputAt(0));
-}
-
-
-TEST(Trim2_live) {
-  ControlReducerTester T;
-  Node* phi =
-      T.graph.NewNode(T.common.Phi(kMachAnyTagged, 2), T.one, T.half, T.start);
-  CHECK(IsUsedBy(T.one, phi));
-  CHECK(IsUsedBy(T.half, phi));
-  CHECK(IsUsedBy(T.start, phi));
-  T.graph.SetEnd(phi);
-  T.Trim();
-  CHECK(IsUsedBy(T.one, phi));
-  CHECK(IsUsedBy(T.half, phi));
-  CHECK(IsUsedBy(T.start, phi));
-  CheckInputs(phi, T.one, T.half, T.start);
-}
-
-
-TEST(Trim2_dead) {
-  ControlReducerTester T;
-  Node* phi =
-      T.graph.NewNode(T.common.Phi(kMachAnyTagged, 2), T.one, T.half, T.start);
-  CHECK(IsUsedBy(T.one, phi));
-  CHECK(IsUsedBy(T.half, phi));
-  CHECK(IsUsedBy(T.start, phi));
-  T.Trim();
-  CHECK(!IsUsedBy(T.one, phi));
-  CHECK(!IsUsedBy(T.half, phi));
-  CHECK(!IsUsedBy(T.start, phi));
-  CHECK(!phi->InputAt(0));
-  CHECK(!phi->InputAt(1));
-  CHECK(!phi->InputAt(2));
-}
-
-
-TEST(Trim_chain1) {
-  ControlReducerTester T;
-  const int kDepth = 15;
-  Node* live[kDepth];
-  Node* dead[kDepth];
-  Node* end = T.start;
-  for (int i = 0; i < kDepth; i++) {
-    live[i] = end = T.graph.NewNode(T.common.Merge(1), end);
-    dead[i] = T.graph.NewNode(T.common.Merge(1), end);
-  }
-  // end         -> live[last] ->  live[last-1] -> ... -> start
-  //     dead[last] ^ dead[last-1] ^ ...                  ^
-  T.graph.SetEnd(end);
-  T.Trim();
-  for (int i = 0; i < kDepth; i++) {
-    CHECK(!IsUsedBy(live[i], dead[i]));
-    CHECK(!dead[i]->InputAt(0));
-    CHECK_EQ(i == 0 ? T.start : live[i - 1], live[i]->InputAt(0));
-  }
-}
-
-
-TEST(Trim_chain2) {
-  ControlReducerTester T;
-  const int kDepth = 15;
-  Node* live[kDepth];
-  Node* dead[kDepth];
-  Node* l = T.start;
-  Node* d = T.start;
-  for (int i = 0; i < kDepth; i++) {
-    live[i] = l = T.graph.NewNode(T.common.Merge(1), l);
-    dead[i] = d = T.graph.NewNode(T.common.Merge(1), d);
-  }
-  // end -> live[last] -> live[last-1] -> ... -> start
-  //        dead[last] -> dead[last-1] -> ... -> start
-  T.graph.SetEnd(l);
-  T.Trim();
-  CHECK(!IsUsedBy(T.start, dead[0]));
-  for (int i = 0; i < kDepth; i++) {
-    CHECK_EQ(i == 0 ? NULL : dead[i - 1], dead[i]->InputAt(0));
-    CHECK_EQ(i == 0 ? T.start : live[i - 1], live[i]->InputAt(0));
-  }
-}
-
-
-TEST(Trim_cycle1) {
-  ControlReducerTester T;
-  Node* loop = T.graph.NewNode(T.common.Loop(1), T.start, T.start);
-  loop->ReplaceInput(1, loop);
-  Node* end = T.graph.NewNode(T.common.End(1), loop);
-  T.graph.SetEnd(end);
-
-  CHECK(IsUsedBy(T.start, loop));
-  CHECK(IsUsedBy(loop, end));
-  CHECK(IsUsedBy(loop, loop));
-
-  T.Trim();
-
-  // nothing should have happened to the loop itself.
-  CHECK(IsUsedBy(T.start, loop));
-  CHECK(IsUsedBy(loop, end));
-  CHECK(IsUsedBy(loop, loop));
-  CheckInputs(loop, T.start, loop);
-  CheckInputs(end, loop);
-}
-
-
-TEST(Trim_cycle2) {
-  ControlReducerTester T;
-  Node* loop = T.graph.NewNode(T.common.Loop(2), T.start, T.start);
-  loop->ReplaceInput(1, loop);
-  Node* end = T.graph.NewNode(T.common.End(1), loop);
-  Node* phi =
-      T.graph.NewNode(T.common.Phi(kMachAnyTagged, 2), T.one, T.half, loop);
-  T.graph.SetEnd(end);
-
-  CHECK(IsUsedBy(T.start, loop));
-  CHECK(IsUsedBy(loop, end));
-  CHECK(IsUsedBy(loop, loop));
-  CHECK(IsUsedBy(loop, phi));
-  CHECK(IsUsedBy(T.one, phi));
-  CHECK(IsUsedBy(T.half, phi));
-
-  T.Trim();
-
-  // nothing should have happened to the loop itself.
-  CHECK(IsUsedBy(T.start, loop));
-  CHECK(IsUsedBy(loop, end));
-  CHECK(IsUsedBy(loop, loop));
-  CheckInputs(loop, T.start, loop);
-  CheckInputs(end, loop);
-
-  // phi should have been trimmed away.
-  CHECK(!IsUsedBy(loop, phi));
-  CHECK(!IsUsedBy(T.one, phi));
-  CHECK(!IsUsedBy(T.half, phi));
-  CHECK(!phi->InputAt(0));
-  CHECK(!phi->InputAt(1));
-  CHECK(!phi->InputAt(2));
-}
-
-
-void CheckTrimConstant(ControlReducerTester* T, Node* k) {
-  Node* phi = T->graph.NewNode(T->common.Phi(kMachInt32, 1), k, T->start);
-  CHECK(IsUsedBy(k, phi));
-  T->Trim();
-  CHECK(!IsUsedBy(k, phi));
-  CHECK(!phi->InputAt(0));
-  CHECK(!phi->InputAt(1));
-}
-
-
-TEST(Trim_constants) {
-  ControlReducerTester T;
-  int32_t int32_constants[] = {
-      0, -1,  -2,  2,  2,  3,  3,  4,  4,  5,  5,  4,  5,  6, 6, 7, 8, 7, 8, 9,
-      0, -11, -12, 12, 12, 13, 13, 14, 14, 15, 15, 14, 15, 6, 6, 7, 8, 7, 8, 9};
-
-  for (size_t i = 0; i < arraysize(int32_constants); i++) {
-    CheckTrimConstant(&T, T.jsgraph.Int32Constant(int32_constants[i]));
-    CheckTrimConstant(&T, T.jsgraph.Float64Constant(int32_constants[i]));
-    CheckTrimConstant(&T, T.jsgraph.Constant(int32_constants[i]));
-  }
-
-  Node* other_constants[] = {
-      T.jsgraph.UndefinedConstant(), T.jsgraph.TheHoleConstant(),
-      T.jsgraph.TrueConstant(),      T.jsgraph.FalseConstant(),
-      T.jsgraph.NullConstant(),      T.jsgraph.ZeroConstant(),
-      T.jsgraph.OneConstant(),       T.jsgraph.NaNConstant(),
-      T.jsgraph.Constant(21),        T.jsgraph.Constant(22.2)};
-
-  for (size_t i = 0; i < arraysize(other_constants); i++) {
-    CheckTrimConstant(&T, other_constants[i]);
-  }
-}
-
-
-TEST(Trim_EmptyFrameState1) {
-  ControlReducerTester T;
-
-  Node* node = T.jsgraph.EmptyFrameState();
-  T.Trim();
-
-  for (Node* input : node->inputs()) {
-    CHECK_NOT_NULL(input);
-  }
-}
-
-
-TEST(Trim_EmptyFrameState2) {
-  ControlReducerTester T;
-  CheckTrimConstant(&T, T.jsgraph.EmptyFrameState());
-}
-
-
 TEST(CReducePhi1) {
   ControlReducerTester R;
 
   R.ReducePhi(R.leaf[0], R.Phi(R.leaf[0]));
   R.ReducePhi(R.leaf[1], R.Phi(R.leaf[1]));
   R.ReducePhi(R.leaf[2], R.Phi(R.leaf[2]));
   R.ReducePhi(R.leaf[3], R.Phi(R.leaf[3]));
 }
 
 
@@ skipping 1084 matching lines @@
 
   R.ReduceGraph();  // d1 gets folded true.
 
   CheckInputs(ret, y2, R.start, R.start);
 
   DeadChecker dead(&R.graph);
   dead.Check(d1);
   dead.Check(d2);
   dead.Check(d3);
 }