Implement tracking and optimizations of packed arrays

src/ia32/lithium-codegen-ia32.cc

Index: src/ia32/lithium-codegen-ia32.cc
diff --git a/src/ia32/lithium-codegen-ia32.cc b/src/ia32/lithium-codegen-ia32.cc
index 053bcb642431a50897839f3244f8cde95ea7a453..2397ca70ca99efb46e543b3ed11ab41df5810f90 100644
--- a/src/ia32/lithium-codegen-ia32.cc
+++ b/src/ia32/lithium-codegen-ia32.cc
@@ -2384,6 +2384,8 @@ void LCodeGen::DoLoadElements(LLoadElements* instr) {
     __ shr(temp, Map::kElementsKindShift);
     __ cmp(temp, FAST_ELEMENTS);
     __ j(equal, &ok, Label::kNear);
+    __ cmp(temp, FAST_HOLEY_ELEMENTS);
+    __ j(equal, &ok, Label::kNear);
     __ cmp(temp, FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND);
     __ j(less, &fail, Label::kNear);
     __ cmp(temp, LAST_EXTERNAL_ARRAY_ELEMENTS_KIND);
@@ -2442,14 +2444,16 @@ void LCodeGen::DoLoadKeyedFastDoubleElement(
     LLoadKeyedFastDoubleElement* instr) {
   XMMRegister result = ToDoubleRegister(instr->result());
 
-  int offset = FixedDoubleArray::kHeaderSize - kHeapObjectTag +
-      sizeof(kHoleNanLower32);
-  Operand hole_check_operand = BuildFastArrayOperand(
-      instr->elements(), instr->key(),
-      FAST_DOUBLE_ELEMENTS,
-      offset);
-  __ cmp(hole_check_operand, Immediate(kHoleNanUpper32));
-  DeoptimizeIf(equal, instr->environment());
+  if (instr->hydrogen()->RequiresHoleCheck()) {
+    int offset = FixedDoubleArray::kHeaderSize - kHeapObjectTag +
+        sizeof(kHoleNanLower32);
+    Operand hole_check_operand = BuildFastArrayOperand(
+        instr->elements(), instr->key(),
+        FAST_DOUBLE_ELEMENTS,
+        offset);
+    __ cmp(hole_check_operand, Immediate(kHoleNanUpper32));
+    DeoptimizeIf(equal, instr->environment());
+  }
 
   Operand double_load_operand = BuildFastArrayOperand(
       instr->elements(), instr->key(), FAST_DOUBLE_ELEMENTS,
@@ -2519,9 +2523,12 @@ void LCodeGen::DoLoadKeyedSpecializedArrayElement(
         break;
       case EXTERNAL_FLOAT_ELEMENTS:
       case EXTERNAL_DOUBLE_ELEMENTS:
-      case FAST_SMI_ONLY_ELEMENTS:
+      case FAST_SMI_ELEMENTS:
       case FAST_ELEMENTS:
       case FAST_DOUBLE_ELEMENTS:
+      case FAST_HOLEY_SMI_ELEMENTS:
+      case FAST_HOLEY_ELEMENTS:
+      case FAST_HOLEY_DOUBLE_ELEMENTS:
       case DICTIONARY_ELEMENTS:
       case NON_STRICT_ARGUMENTS_ELEMENTS:
         UNREACHABLE();
@@ -3444,9 +3451,12 @@ void LCodeGen::DoStoreKeyedSpecializedArrayElement(
         break;
       case EXTERNAL_FLOAT_ELEMENTS:
       case EXTERNAL_DOUBLE_ELEMENTS:
-      case FAST_SMI_ONLY_ELEMENTS:
+      case FAST_SMI_ELEMENTS:
       case FAST_ELEMENTS:
       case FAST_DOUBLE_ELEMENTS:
+      case FAST_HOLEY_SMI_ELEMENTS:
+      case FAST_HOLEY_ELEMENTS:
+      case FAST_HOLEY_DOUBLE_ELEMENTS:
       case DICTIONARY_ELEMENTS:
       case NON_STRICT_ARGUMENTS_ELEMENTS:
         UNREACHABLE();
@@ -3524,7 +3534,6 @@ void LCodeGen::DoStoreKeyedGeneric(LStoreKeyedGeneric* instr) {
   ASSERT(ToRegister(instr->object()).is(edx));
   ASSERT(ToRegister(instr->key()).is(ecx));
   ASSERT(ToRegister(instr->value()).is(eax));
-
   Handle<Code> ic = (instr->strict_mode_flag() == kStrictMode)
       ? isolate()->builtins()->KeyedStoreIC_Initialize_Strict()
       : isolate()->builtins()->KeyedStoreIC_Initialize();
@@ -3545,22 +3554,26 @@ void LCodeGen::DoTransitionElementsKind(LTransitionElementsKind* instr) {
   __ cmp(FieldOperand(object_reg, HeapObject::kMapOffset), from_map);
   __ j(not_equal, &not_applicable);
   __ mov(new_map_reg, to_map);
-  if (from_kind == FAST_SMI_ONLY_ELEMENTS && to_kind == FAST_ELEMENTS) {
+  bool simple_map_change = (GetHoleyElementsKind(from_kind) == to_kind) ||
+      (IsFastSmiElementsKind(from_kind) &&
+       IsFastObjectElementsKind(to_kind));
+  if (simple_map_change) {
     Register object_reg = ToRegister(instr->object());
     __ mov(FieldOperand(object_reg, HeapObject::kMapOffset), new_map_reg);
     // Write barrier.
     ASSERT_NE(instr->temp_reg(), NULL);
     __ RecordWriteField(object_reg, HeapObject::kMapOffset, new_map_reg,
                         ToRegister(instr->temp_reg()), kDontSaveFPRegs);
-  } else if (from_kind == FAST_SMI_ONLY_ELEMENTS &&
-      to_kind == FAST_DOUBLE_ELEMENTS) {
+  } else if (IsFastSmiElementsKind(from_kind) &&
+             IsFastDoubleElementsKind(to_kind)) {
     Register fixed_object_reg = ToRegister(instr->temp_reg());
     ASSERT(fixed_object_reg.is(edx));
     ASSERT(new_map_reg.is(ebx));
     __ mov(fixed_object_reg, object_reg);
     CallCode(isolate()->builtins()->TransitionElementsSmiToDouble(),
              RelocInfo::CODE_TARGET, instr);
-  } else if (from_kind == FAST_DOUBLE_ELEMENTS && to_kind == FAST_ELEMENTS) {
+  } else if (IsFastDoubleElementsKind(from_kind) &&
+             IsFastElementsKind(to_kind)) {
     Register fixed_object_reg = ToRegister(instr->temp_reg());
     ASSERT(fixed_object_reg.is(edx));
     ASSERT(new_map_reg.is(ebx));
@@ -4420,8 +4433,9 @@ void LCodeGen::DoArrayLiteral(LArrayLiteral* instr) {
 
   // Deopt if the array literal boilerplate ElementsKind is of a type different
   // than the expected one. The check isn't necessary if the boilerplate has
-  // already been converted to FAST_ELEMENTS.
-  if (boilerplate_elements_kind != FAST_ELEMENTS) {
+  // already been converted to TERMINAL_FAST_ELEMENTS_KIND.
+  if (CanTransitionToMoreGeneralFastElementsKind(
+          boilerplate_elements_kind, true)) {
     __ LoadHeapObject(eax, instr->hydrogen()->boilerplate_object());
     __ mov(ebx, FieldOperand(eax, HeapObject::kMapOffset));
     // Load the map's "bit field 2". We only need the first byte,