Implement tracking and optimizations of packed arrays

src/arm/lithium-codegen-arm.cc

Index: src/arm/lithium-codegen-arm.cc
diff --git a/src/arm/lithium-codegen-arm.cc b/src/arm/lithium-codegen-arm.cc
index d224d24e5c4d8da8eaa8902199688776f06540f3..fd4b3e84085509a352f9f3fed4805585bfcb0549 100644
--- a/src/arm/lithium-codegen-arm.cc
+++ b/src/arm/lithium-codegen-arm.cc
@@ -2696,8 +2696,10 @@ void LCodeGen::DoLoadElements(LLoadElements* instr) {
     __ ldr(scratch, FieldMemOperand(scratch, Map::kBitField2Offset));
     __ ubfx(scratch, scratch, Map::kElementsKindShift,
             Map::kElementsKindBitCount);
-    __ cmp(scratch, Operand(FAST_ELEMENTS));
-    __ b(eq, &done);
+    __ cmp(scratch, Operand(GetInitialFastElementsKind()));
+    __ b(lt, &fail);
+    __ cmp(scratch, Operand(TERMINAL_FAST_ELEMENTS_KIND));
+    __ b(le, &done);
     __ cmp(scratch, Operand(FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND));
     __ b(lt, &fail);
     __ cmp(scratch, Operand(LAST_EXTERNAL_ARRAY_ELEMENTS_KIND));
@@ -2788,9 +2790,11 @@ void LCodeGen::DoLoadKeyedFastDoubleElement(
                    (instr->additional_index() << shift_size)));
   }
 
-  __ ldr(scratch, MemOperand(elements, sizeof(kHoleNanLower32)));
-  __ cmp(scratch, Operand(kHoleNanUpper32));
-  DeoptimizeIf(eq, instr->environment());
+  if (instr->hydrogen()->RequiresHoleCheck()) {
+    __ ldr(scratch, MemOperand(elements, sizeof(kHoleNanLower32)));
+    __ cmp(scratch, Operand(kHoleNanUpper32));
+    DeoptimizeIf(eq, instr->environment());
+  }
 
   __ vldr(result, elements, 0);
 }
@@ -2866,9 +2870,12 @@ void LCodeGen::DoLoadKeyedSpecializedArrayElement(
         break;
       case EXTERNAL_FLOAT_ELEMENTS:
       case EXTERNAL_DOUBLE_ELEMENTS:
+      case FAST_HOLEY_DOUBLE_ELEMENTS:
+      case FAST_HOLEY_ELEMENTS:
+      case FAST_HOLEY_SMI_ELEMENTS:
       case FAST_DOUBLE_ELEMENTS:
       case FAST_ELEMENTS:
-      case FAST_SMI_ONLY_ELEMENTS:
+      case FAST_SMI_ELEMENTS:
       case DICTIONARY_ELEMENTS:
       case NON_STRICT_ARGUMENTS_ELEMENTS:
         UNREACHABLE();
@@ -3871,7 +3878,10 @@ void LCodeGen::DoStoreKeyedSpecializedArrayElement(
       case EXTERNAL_DOUBLE_ELEMENTS:
       case FAST_DOUBLE_ELEMENTS:
       case FAST_ELEMENTS:
-      case FAST_SMI_ONLY_ELEMENTS:
+      case FAST_SMI_ELEMENTS:
+      case FAST_HOLEY_DOUBLE_ELEMENTS:
+      case FAST_HOLEY_ELEMENTS:
+      case FAST_HOLEY_SMI_ELEMENTS:
       case DICTIONARY_ELEMENTS:
       case NON_STRICT_ARGUMENTS_ELEMENTS:
         UNREACHABLE();
@@ -3908,20 +3918,22 @@ void LCodeGen::DoTransitionElementsKind(LTransitionElementsKind* instr) {
   __ cmp(scratch, Operand(from_map));
   __ b(ne, &not_applicable);
   __ mov(new_map_reg, Operand(to_map));
-  if (from_kind == FAST_SMI_ONLY_ELEMENTS && to_kind == FAST_ELEMENTS) {
+
+  if (IsSimpleMapChangeTransition(from_kind, to_kind)) {
     __ str(new_map_reg, FieldMemOperand(object_reg, HeapObject::kMapOffset));
     // Write barrier.
     __ RecordWriteField(object_reg, HeapObject::kMapOffset, new_map_reg,
                         scratch, kLRHasBeenSaved, 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(r2));
     ASSERT(new_map_reg.is(r3));
     __ 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) &&
+             IsFastObjectElementsKind(to_kind)) {
     Register fixed_object_reg = ToRegister(instr->temp_reg());
     ASSERT(fixed_object_reg.is(r2));
     ASSERT(new_map_reg.is(r3));
@@ -4695,8 +4707,9 @@ 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(r1, instr->hydrogen()->boilerplate_object());
     // Load map into r2.
     __ ldr(r2, FieldMemOperand(r1, HeapObject::kMapOffset));
@@ -4847,10 +4860,11 @@ void LCodeGen::DoFastLiteral(LFastLiteral* instr) {
   ElementsKind boilerplate_elements_kind =
       instr->hydrogen()->boilerplate()->GetElementsKind();
 
-  // Deopt if the 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) {
+  // 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 TERMINAL_FAST_ELEMENTS_KIND.
+  if (CanTransitionToMoreGeneralFastElementsKind(
+          boilerplate_elements_kind, true)) {
     __ LoadHeapObject(r1, instr->hydrogen()->boilerplate());
     // Load map into r2.
     __ ldr(r2, FieldMemOperand(r1, HeapObject::kMapOffset));