[runtime] TailCallRuntime and CallRuntime should use default argument counts

src/ia32/macro-assembler-ia32.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_IA32
 
 #include "src/base/bits.h"
 #include "src/base/division-by-constant.h"
 #include "src/bootstrapper.h"
 #include "src/codegen.h"
@@ skipping 1882 matching lines @@
 void MacroAssembler::CallExternalReference(ExternalReference ref,
                                            int num_arguments) {
   mov(eax, Immediate(num_arguments));
   mov(ebx, Immediate(ref));
 
   CEntryStub stub(isolate(), 1);
   CallStub(&stub);
 }
 
 
-void MacroAssembler::TailCallExternalReference(const ExternalReference& ext,
-                                               int num_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.
-  Move(eax, Immediate(num_arguments));
-  JumpToExternalReference(ext);
+void MacroAssembler::TailCallRuntime(Runtime::FunctionId fid) {
+  // ----------- S t a t e -------------

[Igor Sheludko, 2015/12/30 14:48:17]

Probably we don't need this comment here as all the other platforms also do not
have it.

+  //  -- esp[0]                 : return address
+  //  -- esp[8]                 : argument num_arguments - 1
+  //  ...
+  //  -- esp[8 * num_arguments] : argument 0 (receiver)
+  //
+  //  For runtime functions with variable arguments:
+  //  -- eax                    : number of  arguments
+  // -----------------------------------
+
+  const Runtime::Function* function = Runtime::FunctionForId(fid);
+  DCHECK_EQ(1, function->result_size);
+  if (function->nargs >= 0) {
+    // 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.
+    mov(eax, Immediate(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.
   mov(ebx, Immediate(ext));
   CEntryStub ces(isolate(), 1);
   jmp(ces.GetCode(), RelocInfo::CODE_TARGET);
 }
 
 
 void MacroAssembler::InvokePrologue(const ParameterCount& expected,
                                     const ParameterCount& actual,
@@ skipping 1159 matching lines @@
   mov(eax, dividend);
   shr(eax, 31);
   add(edx, eax);
 }
 
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_TARGET_ARCH_IA32