Direct call C++ functions

src/x64/macro-assembler-x64.h

Index: src/x64/macro-assembler-x64.h
===================================================================
--- src/x64/macro-assembler-x64.h	(revision 3911)
+++ src/x64/macro-assembler-x64.h	(working copy)
@@ -38,6 +38,21 @@
 // function calling convention.
 static const Register kScratchRegister = r10;
 
+// Registers for passing arguments into a C function.
+#ifdef _WIN64
+static const int kCArgRegsCount = 4;
+static const RegList kCCallerSaved =
+    rax.bit() | rcx.bit() | rdx.bit() | r8.bit() |
+    r9.bit() | r10.bit() | r11.bit();
+#else
+static const int kCArgRegsCount = 6;
+static const RegList kCCallerSaved =
+    rax.bit() | rcx.bit() | rdx.bit() | rsi.bit() | rdi.bit() | r8.bit() |
+    r9.bit() | r10.bit() | r11.bit();
+#endif
+extern const Register kCArgRegs[kCArgRegsCount];
+
+
 // Convenience for platform-independent signatures.
 typedef Operand MemOperand;
 
@@ -655,13 +670,18 @@
   void CallExternalReference(const ExternalReference& ext,
                              int num_arguments);
 
-  // Tail call of a runtime routine (jump).
-  // Like JumpToRuntime, but also takes care of passing the number
+  // Tail call of a runtime routine (jump or equivalent if jump is not
+  // possible). Like JumpToRuntime, but also takes care of passing the number
   // of arguments.
-  void TailCallRuntime(const ExternalReference& ext,
+  void TailCallRuntime(Runtime::FunctionId id,
                        int num_arguments,
                        int result_size);
 
+  void TailCallExternalReference(const ExternalReference& ext,
+                                 int num_arguments,
+                                 int result_size);
+
+
   // Jump to a runtime routine.
   void JumpToRuntime(const ExternalReference& ext, int result_size);