Using unsigned shifts and masks when dealing with 64-bit addresses.

BUG=v8:1037

Review URL: http://codereview.chromium.org/6242005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6388 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

include/v8.h

@@ -3367,7 +3367,7 @@ template <> struct SmiTagging<4> {
 
   // For 32-bit systems any 2 bytes aligned pointer can be encoded as smi
   // with a plain reinterpret_cast.
-  static const intptr_t kEncodablePointerMask = 0x1;
+  static const uintptr_t kEncodablePointerMask = 0x1;
   static const int kPointerToSmiShift = 0;
 };
 
@@ -3387,8 +3387,8 @@ template <> struct SmiTagging<8> {
   // It might be not enough to cover stack allocated objects on some platforms.
   static const int kPointerAlignment = 3;
 
-  static const intptr_t kEncodablePointerMask =
-      ~(intptr_t(0xffffffff) << kPointerAlignment);
+  static const uintptr_t kEncodablePointerMask =
+      ~(uintptr_t(0xffffffff) << kPointerAlignment);
 
   static const int kPointerToSmiShift =
       kSmiTagSize + kSmiShiftSize - kPointerAlignment;
@@ -3397,7 +3397,7 @@ template <> struct SmiTagging<8> {
 typedef SmiTagging<kApiPointerSize> PlatformSmiTagging;
 const int kSmiShiftSize = PlatformSmiTagging::kSmiShiftSize;
 const int kSmiValueSize = PlatformSmiTagging::kSmiValueSize;
-const intptr_t kEncodablePointerMask =
+const uintptr_t kEncodablePointerMask =
     PlatformSmiTagging::kEncodablePointerMask;
 const int kPointerToSmiShift = PlatformSmiTagging::kPointerToSmiShift;
 
@@ -3457,7 +3457,7 @@ class Internals {
   }
 
   static inline void* GetExternalPointerFromSmi(internal::Object* value) {
-    const intptr_t address = reinterpret_cast<intptr_t>(value);
+    const uintptr_t address = reinterpret_cast<uintptr_t>(value);
     return reinterpret_cast<void*>(address >> kPointerToSmiShift);
   }
 

src/api.cc

@@ -3267,14 +3267,14 @@ void v8::Object::SetInternalField(int index, v8::Handle<Value> value) {
 
 
 static bool CanBeEncodedAsSmi(void* ptr) {
-  const intptr_t address = reinterpret_cast<intptr_t>(ptr);
+  const uintptr_t address = reinterpret_cast<uintptr_t>(ptr);
   return ((address & i::kEncodablePointerMask) == 0);
 }
 
 
 static i::Smi* EncodeAsSmi(void* ptr) {
   ASSERT(CanBeEncodedAsSmi(ptr));
-  const intptr_t address = reinterpret_cast<intptr_t>(ptr);
+  const uintptr_t address = reinterpret_cast<uintptr_t>(ptr);
   i::Smi* result = reinterpret_cast<i::Smi*>(address << i::kPointerToSmiShift);
   ASSERT(i::Internals::HasSmiTag(result));
   ASSERT_EQ(result, i::Smi::FromInt(result->value()));

test/cctest/test-api.cc

@@ -874,6 +874,10 @@ THREADED_TEST(ExternalWrap) {
   TestExternalPointerWrapping();
 
 #if defined(V8_HOST_ARCH_X64)
+  // Check a value with a leading 1 bit in x64 Smi encoding.
+  expected_ptr = reinterpret_cast<void*>(0x400000000);
+  TestExternalPointerWrapping();
+
   expected_ptr = reinterpret_cast<void*>(0xdeadbeefdeadbeef);
   TestExternalPointerWrapping();