Introduce HTransitionElementsKind instruction.

src/x64/lithium-x64.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 429 matching lines @@
 
 void LStoreKeyedGeneric::PrintDataTo(StringStream* stream) {
   object()->PrintTo(stream);
   stream->Add("[");
   key()->PrintTo(stream);
   stream->Add("] <- ");
   value()->PrintTo(stream);
 }
 
 
+void LTransitionElementsKind::PrintDataTo(StringStream* stream) {
+  object()->PrintTo(stream);
+  stream->Add(" %p -> %p", *original_map(), *transitioned_map());
+}
+
+
 void LChunk::AddInstruction(LInstruction* instr, HBasicBlock* block) {
   LInstructionGap* gap = new LInstructionGap(block);
   int index = -1;
   if (instr->IsControl()) {
     instructions_.Add(gap);
     index = instructions_.length();
     instructions_.Add(instr);
   } else {
     index = instructions_.length();
     instructions_.Add(instr);
@@ skipping 1489 matching lines @@
 
   ASSERT(instr->object()->representation().IsTagged());
   ASSERT(instr->key()->representation().IsTagged());
   ASSERT(instr->value()->representation().IsTagged());
 
   LStoreKeyedGeneric* result = new LStoreKeyedGeneric(object, key, value);
   return MarkAsCall(result, instr);
 }
 
 
+LInstruction* LChunkBuilder::DoTransitionElementsKind(
+    HTransitionElementsKind* instr) {
+  if (instr->original_map()->elements_kind() == FAST_SMI_ONLY_ELEMENTS &&
+      instr->transitioned_map()->elements_kind() == FAST_ELEMENTS) {
+    LOperand* object = UseRegister(instr->object());
+    LOperand* new_map_reg = TempRegister();
+    LOperand* temp_reg = TempRegister();
+    LTransitionElementsKind* result =
+        new LTransitionElementsKind(object, new_map_reg, temp_reg);
+    return DefineSameAsFirst(result);
+  } else {
+    LOperand* object = UseFixed(instr->object(), rax);
+    LOperand* fixed_object_reg = FixedTemp(rdx);
+    LOperand* new_map_reg = FixedTemp(rbx);
+    LTransitionElementsKind* result =
+        new LTransitionElementsKind(object, new_map_reg, fixed_object_reg);
+    return MarkAsCall(DefineFixed(result, rax), instr);
+  }
+}
+
+
 LInstruction* LChunkBuilder::DoStoreNamedField(HStoreNamedField* instr) {
   bool needs_write_barrier = instr->NeedsWriteBarrier();
 
   LOperand* obj = needs_write_barrier
       ? UseTempRegister(instr->object())
       : UseRegisterAtStart(instr->object());
 
   LOperand* val = needs_write_barrier
       ? UseTempRegister(instr->value())
       : UseRegister(instr->value());
@@ skipping 208 matching lines @@
   LOperand* key = UseOrConstantAtStart(instr->key());
   LOperand* object = UseOrConstantAtStart(instr->object());
   LIn* result = new LIn(key, object);
   return MarkAsCall(DefineFixed(result, rax), instr);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64