Line data    Source code

       1             : // Copyright 2013 the V8 project authors. All rights reserved.
       2             : // Use of this source code is governed by a BSD-style license that can be
       3             : // found in the LICENSE file.
       4             : 
       5             : #include "src/crankshaft/hydrogen-dehoist.h"
       6             : 
       7             : #include "src/base/safe_math.h"
       8             : #include "src/objects-inl.h"
       9             : 
      10             : namespace v8 {
      11             : namespace internal {
      12             : 
      13       81172 : static void DehoistArrayIndex(ArrayInstructionInterface* array_operation) {
      14       81172 :   HValue* index = array_operation->GetKey()->ActualValue();
      15      153079 :   if (!index->representation().IsSmiOrInteger32()) return;
      16      151220 :   if (!index->IsAdd() && !index->IsSub()) return;
      17             : 
      18       24326 :   HConstant* constant;
      19             :   HValue* subexpression;
      20             :   HBinaryOperation* binary_operation = HBinaryOperation::cast(index);
      21       15448 :   if (binary_operation->left()->IsConstant() && index->IsAdd()) {
      22             :     subexpression = binary_operation->right();
      23             :     constant = HConstant::cast(binary_operation->left());
      24       11482 :   } else if (binary_operation->right()->IsConstant()) {
      25             :     subexpression = binary_operation->left();
      26             :     constant = HConstant::cast(binary_operation->right());
      27             :   } else {
      28             :     return;
      29             :   }
      30             : 
      31       12163 :   if (!constant->HasInteger32Value()) return;
      32             :   v8::base::internal::CheckedNumeric<int32_t> checked_value =
      33             :       constant->Integer32Value();
      34       33598 :   int32_t sign = binary_operation->IsSub() ? -1 : 1;
      35       12163 :   checked_value = checked_value * sign;
      36             : 
      37             :   // Multiply value by elements size, bailing out on overflow.
      38             :   int32_t elements_kind_size =
      39       12163 :       1 << ElementsKindToShiftSize(array_operation->elements_kind());
      40       12163 :   checked_value = checked_value * elements_kind_size;
      41       12163 :   if (!checked_value.IsValid()) return;
      42       12149 :   int32_t value = checked_value.ValueOrDie();
      43       12149 :   if (value < 0) return;
      44             : 
      45             :   // Ensure that the array operation can add value to existing base offset
      46             :   // without overflowing.
      47        9288 :   if (!array_operation->TryIncreaseBaseOffset(value)) return;
      48             : 
      49        9272 :   array_operation->SetKey(subexpression);
      50        9272 :   if (binary_operation->HasNoUses()) {
      51        6959 :     binary_operation->DeleteAndReplaceWith(NULL);
      52             :   }
      53             : 
      54        9272 :   array_operation->SetDehoisted(true);
      55             : }
      56             : 
      57             : 
      58      283196 : void HDehoistIndexComputationsPhase::Run() {
      59      283196 :   const ZoneList<HBasicBlock*>* blocks(graph()->blocks());
      60     9553508 :   for (int i = 0; i < blocks->length(); ++i) {
      61    38902370 :     for (HInstructionIterator it(blocks->at(i)); !it.Done(); it.Advance()) {
      62             :       HInstruction* instr = it.Current();
      63    50276952 :       if (instr->IsLoadKeyed()) {
      64       52284 :         DehoistArrayIndex(HLoadKeyed::cast(instr));
      65    25086155 :       } else if (instr->IsStoreKeyed()) {
      66       28891 :         DehoistArrayIndex(HStoreKeyed::cast(instr));
      67             :       }
      68             :     }
      69             :   }
      70      283196 : }
      71             : 
      72             : }  // namespace internal
      73             : }  // namespace v8