| Index: src/hydrogen-store-elimination.cc
|
| diff --git a/src/hydrogen-store-elimination.cc b/src/hydrogen-store-elimination.cc
|
| deleted file mode 100644
|
| index f04ec44e44b26e7bec133b7663677f9997fe00d2..0000000000000000000000000000000000000000
|
| --- a/src/hydrogen-store-elimination.cc
|
| +++ /dev/null
|
| @@ -1,122 +0,0 @@
|
| -// 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:
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| - // 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) {
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| - 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
|
|
|