Introduce BUILTIN_CALL_PAIR.

src/assembler.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 796 matching lines @@
 // An ExternalReference represents a C++ address used in the generated
 // code. All references to C++ functions and variables must be encapsulated in
 // an ExternalReference instance. This is done in order to track the origin of
 // all external references in the code so that they can be bound to the correct
 // addresses when deserializing a heap.
 class ExternalReference BASE_EMBEDDED {
  public:
   // Used in the simulator to support different native api calls.
   enum Type {
     // Builtin call.
-    // Object* f(v8::internal::Arguments) or
+    // Object* f(v8::internal::Arguments).
+    BUILTIN_CALL,  // default
+
+    // Builtin call returning object pair.
     // ObjectPair f(v8::internal::Arguments).
-    BUILTIN_CALL,  // default
+    BUILTIN_CALL_PAIR,
 
     // Builtin call that returns .
     // ObjectTriple f(v8::internal::Arguments).
     BUILTIN_CALL_TRIPLE,
 
     // Builtin that takes float arguments and returns an int.
     // int f(double, double).
     BUILTIN_COMPARE_CALL,
 
     // Builtin call that returns floating point.
@@ skipping 204 matching lines @@
                         Type type = ExternalReference::BUILTIN_CALL) {
     ExternalReferenceRedirector* redirector =
         reinterpret_cast<ExternalReferenceRedirector*>(
             isolate->external_reference_redirector());
     void* address = reinterpret_cast<void*>(address_arg);
     void* answer =
         (redirector == NULL) ? address : (*redirector)(isolate, address, type);
     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_;
 };
 
 bool operator==(ExternalReference, ExternalReference);
 bool operator!=(ExternalReference, ExternalReference);
 
 size_t hash_value(ExternalReference);
 
 std::ostream& operator<<(std::ostream&, ExternalReference);
 
@@ skipping 225 matching lines @@
     std::vector<ConstantPoolEntry> shared_entries;
   };
 
   Label emitted_label_;  // Records pc_offset of emitted pool
   PerTypeEntryInfo info_[ConstantPoolEntry::NUMBER_OF_TYPES];
 };
 
 }  // namespace internal
 }  // namespace v8
 #endif  // V8_ASSEMBLER_H_