implement fast ReturnValue setters

src/objects-inl.h

 // Copyright 2012 the V8 project authors. 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.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1012 matching lines @@
 }
 
 
 int Smi::value() {
   return Internals::SmiValue(this);
 }
 
 
 Smi* Smi::FromInt(int value) {
   ASSERT(Smi::IsValid(value));
-  int smi_shift_bits = kSmiTagSize + kSmiShiftSize;
-  intptr_t tagged_value =
-      (static_cast<intptr_t>(value) << smi_shift_bits) | kSmiTag;
-  return reinterpret_cast<Smi*>(tagged_value);
+  return reinterpret_cast<Smi*>(Internals::IntToSmi(value));
 }
 
 
 Smi* Smi::FromIntptr(intptr_t value) {
   ASSERT(Smi::IsValid(value));
   int smi_shift_bits = kSmiTagSize + kSmiShiftSize;
   return reinterpret_cast<Smi*>((value << smi_shift_bits) | kSmiTag);
 }
 
 
@@ skipping 58 matching lines @@
   // Fill the unused bits with a pattern that's easy to recognize in crash
   // dumps.
   static const int kFailureMagicPattern = 0x0BAD0000;
   return reinterpret_cast<Failure*>(
       (info << kFailureTagSize) | kFailureTag | kFailureMagicPattern);
 }
 
 
 bool Smi::IsValid(intptr_t value) {
 #ifdef DEBUG
   bool in_range = (value >= kMinValue) && (value <= kMaxValue);

[Sven Panne, 2013/05/21 14:14:56]

Not from your CL, but anyway: Can we inline this and use an ASSERT_EQ?

[dcarney, 2013/05/21 15:14:44]

okay

 #endif
-
-#ifdef V8_TARGET_ARCH_X64
-  // To be representable as a long smi, the value must be a 32-bit integer.
-  bool result = (value == static_cast<int32_t>(value));
-#else
-  // To be representable as an tagged small integer, the two
-  // most-significant bits of 'value' must be either 00 or 11 due to
-  // sign-extension. To check this we add 01 to the two
-  // most-significant bits, and check if the most-significant bit is 0
-  //
-  // CAUTION: The original code below:
-  // bool result = ((value + 0x40000000) & 0x80000000) == 0;
-  // may lead to incorrect results according to the C language spec, and
-  // in fact doesn't work correctly with gcc4.1.1 in some cases: The
-  // compiler may produce undefined results in case of signed integer
-  // overflow. The computation must be done w/ unsigned ints.
-  bool result = (static_cast<uintptr_t>(value + 0x40000000U) < 0x80000000U);
-#endif
+  bool result = Internals::IsValidSmi(value);
   ASSERT(result == in_range);
   return result;
 }
 
 
 MapWord MapWord::FromMap(Map* map) {
   return MapWord(reinterpret_cast<uintptr_t>(map));
 }
 
 
@@ skipping 5076 matching lines @@
 #undef WRITE_UINT32_FIELD
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_