Move Hydrogen and Lithium to src/crankshaft/

src/hydrogen-store-elimination.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-instructions.h"
-#include "src/hydrogen-store-elimination.h"
-
-namespace v8 {
-namespace internal {
-
-#define TRACE(x) if (FLAG_trace_store_elimination) PrintF x
-
-// Performs a block-by-block local analysis for removable stores.
-void HStoreEliminationPhase::Run() {
-  GVNFlagSet flags;  // Use GVN flags as an approximation for some instructions.
-  flags.RemoveAll();
-
-  flags.Add(kArrayElements);
-  flags.Add(kArrayLengths);
-  flags.Add(kStringLengths);
-  flags.Add(kBackingStoreFields);
-  flags.Add(kDoubleArrayElements);
-  flags.Add(kDoubleFields);
-  flags.Add(kElementsPointer);
-  flags.Add(kInobjectFields);
-  flags.Add(kExternalMemory);
-  flags.Add(kStringChars);
-  flags.Add(kTypedArrayElements);
-
-  for (int i = 0; i < graph()->blocks()->length(); i++) {
-    unobserved_.Rewind(0);
-    HBasicBlock* block = graph()->blocks()->at(i);
-    if (!block->IsReachable()) continue;
-    for (HInstructionIterator it(block); !it.Done(); it.Advance()) {
-      HInstruction* instr = it.Current();
-      if (instr->CheckFlag(HValue::kIsDead)) continue;
-
-      // TODO(titzer): eliminate unobserved HStoreKeyed instructions too.
-      switch (instr->opcode()) {
-        case HValue::kStoreNamedField:
-          // Remove any unobserved stores overwritten by this store.
-          ProcessStore(HStoreNamedField::cast(instr));
-          break;
-        case HValue::kLoadNamedField:
-          // Observe any unobserved stores on this object + field.
-          ProcessLoad(HLoadNamedField::cast(instr));
-          break;
-        default:
-          ProcessInstr(instr, flags);
-          break;
-      }
-    }
-  }
-}
-
-
-void HStoreEliminationPhase::ProcessStore(HStoreNamedField* store) {
-  HValue* object = store->object()->ActualValue();
-  int i = 0;
-  while (i < unobserved_.length()) {
-    HStoreNamedField* prev = unobserved_.at(i);
-    if (aliasing_->MustAlias(object, prev->object()->ActualValue()) &&
-        prev->CanBeReplacedWith(store)) {
-      // This store is guaranteed to overwrite the previous store.
-      prev->DeleteAndReplaceWith(NULL);
-      TRACE(("++ Unobserved store S%d overwritten by S%d\n",
-             prev->id(), store->id()));
-      unobserved_.Remove(i);
-    } else {
-      // TODO(titzer): remove map word clearing from folded allocations.
-      i++;
-    }
-  }
-  // Only non-transitioning stores are removable.
-  if (!store->has_transition()) {
-    TRACE(("-- Might remove store S%d\n", store->id()));
-    unobserved_.Add(store, zone());
-  }
-}
-
-
-void HStoreEliminationPhase::ProcessLoad(HLoadNamedField* load) {
-  HValue* object = load->object()->ActualValue();
-  int i = 0;
-  while (i < unobserved_.length()) {
-    HStoreNamedField* prev = unobserved_.at(i);
-    if (aliasing_->MayAlias(object, prev->object()->ActualValue()) &&
-        load->access().Equals(prev->access())) {
-      TRACE(("-- Observed store S%d by load L%d\n", prev->id(), load->id()));
-      unobserved_.Remove(i);
-    } else {
-      i++;
-    }
-  }
-}
-
-
-void HStoreEliminationPhase::ProcessInstr(HInstruction* instr,
-    GVNFlagSet flags) {
-  if (unobserved_.length() == 0) return;  // Nothing to do.
-  if (instr->CanDeoptimize()) {
-    TRACE(("-- Observed stores at I%d (%s might deoptimize)\n",
-           instr->id(), instr->Mnemonic()));
-    unobserved_.Rewind(0);
-    return;
-  }
-  if (instr->CheckChangesFlag(kNewSpacePromotion)) {
-    TRACE(("-- Observed stores at I%d (%s might GC)\n",
-           instr->id(), instr->Mnemonic()));
-    unobserved_.Rewind(0);
-    return;
-  }
-  if (instr->DependsOnFlags().ContainsAnyOf(flags)) {
-    TRACE(("-- Observed stores at I%d (GVN flags of %s)\n",
-           instr->id(), instr->Mnemonic()));
-    unobserved_.Rewind(0);
-    return;
-  }
-}
-
-}  // namespace internal
-}  // namespace v8