Encapsulate megamorphic load/tail-call in hydrogen

src/x64/lithium-codegen-x64.cc

 // Copyright 2013 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/base/bits.h"
 #include "src/code-stubs.h"
 #include "src/hydrogen-osr.h"
+#include "src/ic/stub-cache.h"
 #include "src/x64/lithium-codegen-x64.h"
 
 namespace v8 {
 namespace internal {
 
 
 // When invoking builtins, we need to record the safepoint in the middle of
 // the invoke instruction sequence generated by the macro assembler.
 class SafepointGenerator FINAL : public CallWrapper {
  public:
@@ skipping 3198 matching lines @@
               Representation::Smi());
       __ AssertSmi(scratch);
     }
     // Read int value directly from upper half of the smi.
     STATIC_ASSERT(kSmiTag == 0);
     DCHECK(kSmiTagSize + kSmiShiftSize == 32);
     offset += kPointerSize / 2;
   }
 
   __ Load(result,
-          BuildFastArrayOperand(instr->elements(),
-                                key,
+          BuildFastArrayOperand(instr->elements(), key,
                                 instr->hydrogen()->key()->representation(),
-                                FAST_ELEMENTS,
-                                offset),
+                                FAST_ELEMENTS, offset),
           representation);
 
   // Check for the hole value.
   if (requires_hole_check) {
     if (IsFastSmiElementsKind(hinstr->elements_kind())) {
       Condition smi = __ CheckSmi(result);
       DeoptimizeIf(NegateCondition(smi), instr->environment());
     } else {
       __ CompareRoot(result, Heap::kTheHoleValueRootIndex);
       DeoptimizeIf(equal, instr->environment());
@@ skipping 279 matching lines @@
     // We need to adapt arguments.
     SafepointGenerator generator(
         this, pointers, Safepoint::kLazyDeopt);
     ParameterCount count(arity);
     ParameterCount expected(formal_parameter_count);
     __ InvokeFunction(function, expected, count, CALL_FUNCTION, generator);
   }
 }
 
 
+void LCodeGen::DoTailCallThroughMegamorphicCache(
+    LTailCallThroughMegamorphicCache* instr) {
+  Register receiver = ToRegister(instr->receiver());
+  Register name = ToRegister(instr->name());
+  DCHECK(receiver.is(LoadDescriptor::ReceiverRegister()));
+  DCHECK(name.is(LoadDescriptor::NameRegister()));
+
+  Register scratch = rbx;
+  DCHECK(!scratch.is(receiver) && !scratch.is(name));
+
+  // Important for the tail-call.
+  bool must_teardown_frame = NeedsEagerFrame();
+
+  // The probe will tail call to a handler if found.
+  isolate()->stub_cache()->GenerateProbe(masm(), instr->hydrogen()->flags(),
+                                         must_teardown_frame, receiver, name,
+                                         scratch, no_reg);
+
+  // Tail call to miss if we ended up here.
+  if (must_teardown_frame) __ leave();
+  LoadIC::GenerateMiss(masm());
+}
+
+
 void LCodeGen::DoCallWithDescriptor(LCallWithDescriptor* instr) {
   DCHECK(ToRegister(instr->result()).is(rax));
 
   LPointerMap* pointers = instr->pointer_map();
   SafepointGenerator generator(this, pointers, Safepoint::kLazyDeopt);
 
   if (instr->target()->IsConstantOperand()) {
     LConstantOperand* target = LConstantOperand::cast(instr->target());
     Handle<Code> code = Handle<Code>::cast(ToHandle(target));
     generator.BeforeCall(__ CallSize(code));
@@ skipping 2308 matching lines @@
   CallRuntime(Runtime::kPushBlockContext, 2, instr);
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64