First take on custom call generators.

src/x64/stub-cache-x64.cc

Index: src/x64/stub-cache-x64.cc
diff --git a/src/x64/stub-cache-x64.cc b/src/x64/stub-cache-x64.cc
index 1517fd3af7dc164ea7ad196f9239b80678673ddf..9d63889ce50617f5f3e5085e1b01851e86397e05 100644
--- a/src/x64/stub-cache-x64.cc
+++ b/src/x64/stub-cache-x64.cc
@@ -655,6 +655,63 @@ class CallInterceptorCompiler BASE_EMBEDDED {
 #define __ ACCESS_MASM((masm()))
 
 
+Object* CallStubCompiler::CompileArrayPushCall(Object* object,
+                                               JSObject* holder,
+                                               JSFunction* function,
+                                               String* name,
+                                               CheckType check) {
+  // ----------- S t a t e -------------
+  // rcx                 : function name
+  // rsp[0]              : return address
+  // rsp[8]              : argument argc
+  // rsp[16]             : argument argc - 1
+  // ...
+  // rsp[argc * 8]       : argument 1
+  // rsp[(argc + 1) * 8] : argument 0 = receiver
+  // -----------------------------------
+
+  // TODO(639): faster implementation.
+  ASSERT(check == RECEIVER_MAP_CHECK);
+
+  Label miss;
+
+  // Get the receiver from the stack.
+  const int argc = arguments().immediate();
+  __ movq(rdx, Operand(rsp, (argc + 1) * kPointerSize));
+
+  // Check that the receiver isn't a smi.
+  __ JumpIfSmi(rdx, &miss);
+
+  // Check that the maps haven't changed.
+  CheckPrototypes(JSObject::cast(object), rdx, holder,
+                  rbx, rax, name, &miss);
+
+  // Patch the receiver on the stack with the global proxy if
+  // necessary.
+  if (object->IsGlobalObject()) {
+    __ movq(rdx, FieldOperand(rdx, GlobalObject::kGlobalReceiverOffset));
+    __ movq(Operand(rsp, (argc + 1) * kPointerSize), rdx);
+  }
+
+  __ TailCallExternalReference(ExternalReference(Builtins::c_ArrayPush),
+                               argc + 1,
+                               1);
+
+
+  // Handle call cache miss.
+  __ bind(&miss);
+  Handle<Code> ic = ComputeCallMiss(arguments().immediate());
+  __ Jump(ic, RelocInfo::CODE_TARGET);
+
+  // Return the generated code.
+  String* function_name = NULL;
+  if (function->shared()->name()->IsString()) {
+    function_name = String::cast(function->shared()->name());
+  }
+  return GetCode(CONSTANT_FUNCTION, function_name);
+}
+
+
 Object* CallStubCompiler::CompileCallConstant(Object* object,
                                               JSObject* holder,
                                               JSFunction* function,
@@ -670,6 +727,13 @@ Object* CallStubCompiler::CompileCallConstant(Object* object,
   // rsp[(argc + 1) * 8] : argument 0 = receiver
   // -----------------------------------
 
+  SharedFunctionInfo* function_info = function->shared();
+  if (function_info->HasCustomCallGenerator()) {
+    CustomCallGenerator generator =
+        ToCData<CustomCallGenerator>(function_info->function_data());
+    return generator(this, object, holder, function, name, check);
+  }
+
   Label miss;
 
   // Get the receiver from the stack.