Introduce BUILTIN_CALL_PAIR.

src/assembler.h

Index: src/assembler.h
diff --git a/src/assembler.h b/src/assembler.h
index fd7b16134b4ba645212b86adf45f77e99d417f45..6a1e4c320ef787d9bb0edf0f647d1991e6568641 100644
--- a/src/assembler.h
+++ b/src/assembler.h
@@ -814,10 +814,13 @@ class ExternalReference BASE_EMBEDDED {
   // Used in the simulator to support different native api calls.
   enum Type {
     // Builtin call.
-    // Object* f(v8::internal::Arguments) or
-    // ObjectPair f(v8::internal::Arguments).
+    // Object* f(v8::internal::Arguments).
     BUILTIN_CALL,  // default
 
+    // Builtin call returning object pair.
+    // ObjectPair f(v8::internal::Arguments).
+    BUILTIN_CALL_PAIR,
+
     // Builtin call that returns .
     // ObjectTriple f(v8::internal::Arguments).
     BUILTIN_CALL_TRIPLE,
@@ -1041,6 +1044,24 @@ class ExternalReference BASE_EMBEDDED {
     return answer;
   }
 
+  static Type builtin_call_type(int size) {

[rmcilroy, 2016/01/22 11:13:52]

/s/size/result_size

[rmcilroy, 2016/01/22 11:13:52]

Just call this BuiltinCallTypeForResultSize and make it a static helper function
in assembler.cc (it doesn't give the call type for other builtins like compare,
etc.)

[MTBrandyberry, 2016/01/22 14:53:53]

Done.

[MTBrandyberry, 2016/01/22 14:53:53]

Done.

+    Type type;
+    switch (size) {
+      case 1:
+        type = BUILTIN_CALL;
+        break;

[rmcilroy, 2016/01/22 11:13:52]

nit - just "return BUILTIN_CALL" directly, no need for the type variable (or
break). For the other cases too. 

[MTBrandyberry, 2016/01/22 14:53:53]

Done.

+      case 2:
+        type = BUILTIN_CALL_PAIR;
+        break;
+      case 3:
+        type = BUILTIN_CALL_TRIPLE;
+        break;
+      default:
+        UNREACHABLE();
+    }
+    return type;
+  }
+
   void* address_;
 };