Encapsulate megamorphic load/tail-call in hydrogen

src/x64/lithium-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/hydrogen-osr.h"
 #include "src/lithium-inl.h"
@@ skipping 1101 matching lines @@
         UseFixed(instr->OperandAt(i), descriptor.GetParameterRegister(i - 1));
     ops.Add(op, zone());
   }
 
   LCallWithDescriptor* result = new(zone()) LCallWithDescriptor(
       descriptor, ops, zone());
   return MarkAsCall(DefineFixed(result, rax), instr);
 }
 
 
+LInstruction* LChunkBuilder::DoTailCallThroughMegamorphicCache(
+    HTailCallThroughMegamorphicCache* instr) {
+  LOperand* context = UseFixed(instr->context(), rsi);
+  LOperand* receiver_register =
+      UseFixed(instr->receiver(), LoadDescriptor::ReceiverRegister());
+  LOperand* name_register =
+      UseFixed(instr->name(), LoadDescriptor::NameRegister());
+  // Not marked as call. It can't deoptimize, and it never returns.
+  return new (zone()) LTailCallThroughMegamorphicCache(
+      context, receiver_register, name_register);
+}
+
+
 LInstruction* LChunkBuilder::DoInvokeFunction(HInvokeFunction* instr) {
   LOperand* context = UseFixed(instr->context(), rsi);
   LOperand* function = UseFixed(instr->function(), rdi);
   LInvokeFunction* result = new(zone()) LInvokeFunction(context, function);
   return MarkAsCall(DefineFixed(result, rax), instr, CANNOT_DEOPTIMIZE_EAGERLY);
 }
 
 
 LInstruction* LChunkBuilder::DoUnaryMathOperation(HUnaryMathOperation* instr) {
   switch (instr->op()) {
@@ skipping 1545 matching lines @@
   LOperand* function = UseRegisterAtStart(instr->function());
   LAllocateBlockContext* result =
       new(zone()) LAllocateBlockContext(context, function);
   return MarkAsCall(DefineFixed(result, rsi), instr);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64