Move Hydrogen and Lithium to src/crankshaft/

src/hydrogen-dce.cc

-// Copyright 2013 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/hydrogen-dce.h"
-
-namespace v8 {
-namespace internal {
-
-void HDeadCodeEliminationPhase::MarkLive(
-    HValue* instr, ZoneList<HValue*>* worklist) {
-  if (instr->CheckFlag(HValue::kIsLive)) return;  // Already live.
-
-  if (FLAG_trace_dead_code_elimination) PrintLive(NULL, instr);
-
-  // Transitively mark all inputs of live instructions live.
-  worklist->Add(instr, zone());
-  while (!worklist->is_empty()) {
-    HValue* instr = worklist->RemoveLast();
-    instr->SetFlag(HValue::kIsLive);
-    for (int i = 0; i < instr->OperandCount(); ++i) {
-      HValue* input = instr->OperandAt(i);
-      if (!input->CheckFlag(HValue::kIsLive)) {
-        input->SetFlag(HValue::kIsLive);
-        worklist->Add(input, zone());
-        if (FLAG_trace_dead_code_elimination) PrintLive(instr, input);
-      }
-    }
-  }
-}
-
-
-void HDeadCodeEliminationPhase::PrintLive(HValue* ref, HValue* instr) {
-  AllowHandleDereference allow_deref;
-  OFStream os(stdout);
-  os << "[MarkLive ";
-  if (ref != NULL) {
-    os << *ref;
-  } else {
-    os << "root";
-  }
-  os << " -> " << *instr << "]" << std::endl;
-}
-
-
-void HDeadCodeEliminationPhase::MarkLiveInstructions() {
-  ZoneList<HValue*> worklist(10, zone());
-
-  // Transitively mark all live instructions, starting from roots.
-  for (int i = 0; i < graph()->blocks()->length(); ++i) {
-    HBasicBlock* block = graph()->blocks()->at(i);
-    for (HInstructionIterator it(block); !it.Done(); it.Advance()) {
-      HInstruction* instr = it.Current();
-      if (instr->CannotBeEliminated()) MarkLive(instr, &worklist);
-    }
-    for (int j = 0; j < block->phis()->length(); j++) {
-      HPhi* phi = block->phis()->at(j);
-      if (phi->CannotBeEliminated()) MarkLive(phi, &worklist);
-    }
-  }
-
-  DCHECK(worklist.is_empty());  // Should have processed everything.
-}
-
-
-void HDeadCodeEliminationPhase::RemoveDeadInstructions() {
-  ZoneList<HPhi*> worklist(graph()->blocks()->length(), zone());
-
-  // Remove any instruction not marked kIsLive.
-  for (int i = 0; i < graph()->blocks()->length(); ++i) {
-    HBasicBlock* block = graph()->blocks()->at(i);
-    for (HInstructionIterator it(block); !it.Done(); it.Advance()) {
-      HInstruction* instr = it.Current();
-      if (!instr->CheckFlag(HValue::kIsLive)) {
-        // Instruction has not been marked live, so remove it.
-        instr->DeleteAndReplaceWith(NULL);
-      } else {
-        // Clear the liveness flag to leave the graph clean for the next DCE.
-        instr->ClearFlag(HValue::kIsLive);
-      }
-    }
-    // Collect phis that are dead and remove them in the next pass.
-    for (int j = 0; j < block->phis()->length(); j++) {
-      HPhi* phi = block->phis()->at(j);
-      if (!phi->CheckFlag(HValue::kIsLive)) {
-        worklist.Add(phi, zone());
-      } else {
-        phi->ClearFlag(HValue::kIsLive);
-      }
-    }
-  }
-
-  // Process phis separately to avoid simultaneously mutating the phi list.
-  while (!worklist.is_empty()) {
-    HPhi* phi = worklist.RemoveLast();
-    HBasicBlock* block = phi->block();
-    phi->DeleteAndReplaceWith(NULL);
-    if (phi->HasMergedIndex()) {
-      block->RecordDeletedPhi(phi->merged_index());
-    }
-  }
-}
-
-}  // namespace internal
-}  // namespace v8