Index: src/hydrogen-dehoist.cc |
diff --git a/src/hydrogen-dehoist.cc b/src/hydrogen-dehoist.cc |
index fe0ae764ad63dcf3fc6c3ca625ebd90cdea7fcf7..c72d4be8a55c3c66f397181618c4821b092b3a2a 100644 |
--- a/src/hydrogen-dehoist.cc |
+++ b/src/hydrogen-dehoist.cc |
@@ -28,15 +28,23 @@ static void DehoistArrayIndex(ArrayInstructionInterface* array_operation) { |
if (!constant->HasInteger32Value()) return; |
int32_t sign = binary_operation->IsSub() ? -1 : 1; |
int32_t value = constant->Integer32Value() * sign; |
- // We limit offset values to 30 bits because we want to avoid the risk of |
- // overflows when the offset is added to the object header size. |
- if (value >= 1 << array_operation->MaxBaseOffsetBits() || value < 0) return; |
+ if (value < 0) return; |
+ |
+ // Multiply value by elements size, bailing out on overflow. |
+ int32_t elements_kind_size = |
+ 1 << ElementsKindToShiftSize(array_operation->elements_kind()); |
+ if (MultiplyOverflows(value, elements_kind_size)) return; |
+ value *= elements_kind_size; |
+ |
+ // Ensure that the array operation can add value to existing base offset |
+ // without overflowing. |
+ if (!array_operation->TryIncreaseBaseOffset(value)) return; |
+ |
array_operation->SetKey(subexpression); |
if (binary_operation->HasNoUses()) { |
binary_operation->DeleteAndReplaceWith(NULL); |
} |
- value <<= ElementsKindToShiftSize(array_operation->elements_kind()); |
- array_operation->IncreaseBaseOffset(static_cast<uint32_t>(value)); |
+ |
array_operation->SetDehoisted(true); |
} |