[runtime] TailCallRuntime and CallRuntime should use default argument counts

src/x64/macro-assembler-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.
 
 #if V8_TARGET_ARCH_X64
 
 #include "src/base/bits.h"
 #include "src/base/division-by-constant.h"
 #include "src/bootstrapper.h"
 #include "src/codegen.h"
@@ skipping 644 matching lines @@
 void MacroAssembler::CallExternalReference(const ExternalReference& ext,
                                            int num_arguments) {
   Set(rax, num_arguments);
   LoadAddress(rbx, ext);
 
   CEntryStub stub(isolate(), 1);
   CallStub(&stub);
 }
 
 
-void MacroAssembler::TailCallExternalReference(const ExternalReference& ext,
-                                               int num_arguments) {
+void MacroAssembler::TailCallRuntime(Runtime::FunctionId fid) {
   // ----------- S t a t e -------------
   //  -- rsp[0]                 : return address
   //  -- rsp[8]                 : argument num_arguments - 1
   //  ...
   //  -- rsp[8 * num_arguments] : argument 0 (receiver)
+  //
+  //  For runtime functions with variable arguments:
+  //  -- rax                    : number of  arguments
   // -----------------------------------
 
-  // TODO(1236192): Most runtime routines don't need the number of
-  // arguments passed in because it is constant. At some point we
-  // should remove this need and make the runtime routine entry code
-  // smarter.
-  Set(rax, num_arguments);
-  JumpToExternalReference(ext);
+  const Runtime::Function* function = Runtime::FunctionForId(fid);
+  DCHECK_EQ(1, function->result_size);
+  if (function->nargs >= 0) {

[Igor Sheludko, 2015/12/30 14:48:18]

Ditto.

+    Set(rax, function->nargs);
+  }
+  JumpToExternalReference(ExternalReference(fid, isolate()));
 }
 
 
-void MacroAssembler::TailCallRuntime(Runtime::FunctionId fid,
-                                     int num_arguments) {
-  TailCallExternalReference(ExternalReference(fid, isolate()), num_arguments);
-}
-
-
 void MacroAssembler::JumpToExternalReference(const ExternalReference& ext) {
   // Set the entry point and jump to the C entry runtime stub.
   LoadAddress(rbx, ext);
   CEntryStub ces(isolate(), 1);
   jmp(ces.GetCode(), RelocInfo::CODE_TARGET);
 }
 
 
 void MacroAssembler::InvokeBuiltin(int native_context_index, InvokeFlag flag,
                                    const CallWrapper& call_wrapper) {
@@ skipping 4765 matching lines @@
   movl(rax, dividend);
   shrl(rax, Immediate(31));
   addl(rdx, rax);
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_X64