Thumb2 Backend: Update Code objects with mode, separate Assembler methods for Thumb2

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index 89abe5043358c14642512f8d677104151b72a2d5..8a281901f9902af1c3251f0560da1fa3dd05e46d 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -1228,6 +1228,7 @@ void HeapObject::set_map_word(MapWord map_word) {
 
 
 HeapObject* HeapObject::FromAddress(Address address) {
+  address = (Address)((uint32_t)address & ~1);
   ASSERT_TAG_ALIGNED(address);
   return reinterpret_cast<HeapObject*>(address + kHeapObjectTag);
 }
@@ -3870,6 +3871,11 @@ void Code::set_is_pregenerated(bool value) {
 }
 
 
+bool Code::is_thumb_mode() {
+  return IsThumbModeField::decode(flags());
+}
+
+
 bool Code::optimizable() {
   ASSERT_EQ(FUNCTION, kind());
   return READ_BYTE_FIELD(this, kOptimizableOffset) == 1;
@@ -4082,12 +4088,18 @@ bool Code::is_debug_stub() {
 }
 
 
+Code::Flags Code::SetThumbModeInFlags(Code::Flags flag) {
+  return static_cast<Flags>(flag | IsThumbModeField::encode(true));
+}
+
+
 Code::Flags Code::ComputeFlags(Kind kind,
                                InlineCacheState ic_state,
                                ExtraICState extra_ic_state,
                                StubType type,
                                int argc,
-                               InlineCacheHolderFlag holder) {
+                               InlineCacheHolderFlag holder,
+                               bool thumb_mode) {
   ASSERT(argc <= Code::kMaxArguments);
   // Since the extended extra ic state overlaps with the argument count
   // for CALL_ICs, do so checks to make sure that they don't interfere.
@@ -4099,7 +4111,8 @@ Code::Flags Code::ComputeFlags(Kind kind,
       | ICStateField::encode(ic_state)
       | TypeField::encode(type)
       | ExtendedExtraICStateField::encode(extra_ic_state)
-      | CacheHolderField::encode(holder);
+      | CacheHolderField::encode(holder)
+      | IsThumbModeField::encode(thumb_mode);
   if (!Code::needs_extended_extra_ic_state(kind)) {
     bits |= (argc << kArgumentsCountShift);
   }
@@ -4159,6 +4172,7 @@ Code::Flags Code::RemoveTypeFromFlags(Flags flags) {
 
 
 Code* Code::GetCodeFromTargetAddress(Address address) {
+  address = (Address)((uint32_t)address & ~3);
   HeapObject* code = HeapObject::FromAddress(address - Code::kHeaderSize);
   // GetCodeFromTargetAddress might be called when marking objects during mark
   // sweep. reinterpret_cast is therefore used instead of the more appropriate
@@ -4171,7 +4185,9 @@ Code* Code::GetCodeFromTargetAddress(Address address) {
 
 Object* Code::GetObjectFromEntryAddress(Address location_of_address) {
   return HeapObject::
-      FromAddress(Memory::Address_at(location_of_address) - Code::kHeaderSize);
+      FromAddress(
+          Memory::Address_at((Address)((uint32_t)location_of_address & ~1))
+          - Code::kHeaderSize);
 }
 
 
@@ -5351,7 +5367,8 @@ int Code::relocation_size() {
 
 
 byte* Code::entry() {
-  return instruction_start();
+  int mode_encoding = is_thumb_mode() ? 1 : 0;
+  return mode_encoding + instruction_start();
 }