Update V8 to r6333 (2.5 branch)
Note: we temporarily deviate from 9.0.597.x to pull v8 v2.5.9.9
Change-Id: I08d06e15a1a3af206fb23f98f56c81fe579e1a78
http://v8.googlecode.com/svn/branches/2.5@6333
diff --git a/include/v8.h b/include/v8.h
index 8ecf63a..2684cd3 100644
--- a/include/v8.h
+++ b/include/v8.h
@@ -3300,10 +3300,10 @@
const int kSmiTagSize = 1;
const intptr_t kSmiTagMask = (1 << kSmiTagSize) - 1;
-template <size_t ptr_size> struct SmiConstants;
+template <size_t ptr_size> struct SmiTagging;
// Smi constants for 32-bit systems.
-template <> struct SmiConstants<4> {
+template <> struct SmiTagging<4> {
static const int kSmiShiftSize = 0;
static const int kSmiValueSize = 31;
static inline int SmiToInt(internal::Object* value) {
@@ -3311,10 +3311,15 @@
// Throw away top 32 bits and shift down (requires >> to be sign extending).
return static_cast<int>(reinterpret_cast<intptr_t>(value)) >> shift_bits;
}
+
+ // 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 int kPointerToSmiShift = 0;
};
// Smi constants for 64-bit systems.
-template <> struct SmiConstants<8> {
+template <> struct SmiTagging<8> {
static const int kSmiShiftSize = 31;
static const int kSmiValueSize = 32;
static inline int SmiToInt(internal::Object* value) {
@@ -3322,10 +3327,26 @@
// Shift down and throw away top 32 bits.
return static_cast<int>(reinterpret_cast<intptr_t>(value) >> shift_bits);
}
+
+ // To maximize the range of pointers that can be encoded
+ // in the available 32 bits, we require them to be 8 bytes aligned.
+ // This gives 2 ^ (32 + 3) = 32G address space covered.
+ // 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 int kPointerToSmiShift =
+ kSmiTagSize + kSmiShiftSize - kPointerAlignment;
};
-const int kSmiShiftSize = SmiConstants<kApiPointerSize>::kSmiShiftSize;
-const int kSmiValueSize = SmiConstants<kApiPointerSize>::kSmiValueSize;
+typedef SmiTagging<kApiPointerSize> PlatformSmiTagging;
+const int kSmiShiftSize = PlatformSmiTagging::kSmiShiftSize;
+const int kSmiValueSize = PlatformSmiTagging::kSmiValueSize;
+const intptr_t kEncodablePointerMask =
+ PlatformSmiTagging::kEncodablePointerMask;
+const int kPointerToSmiShift = PlatformSmiTagging::kPointerToSmiShift;
template <size_t ptr_size> struct InternalConstants;
@@ -3373,7 +3394,7 @@
}
static inline int SmiValue(internal::Object* value) {
- return SmiConstants<kApiPointerSize>::SmiToInt(value);
+ return PlatformSmiTagging::SmiToInt(value);
}
static inline int GetInstanceType(internal::Object* obj) {
@@ -3382,9 +3403,14 @@
return ReadField<uint8_t>(map, kMapInstanceTypeOffset);
}
+ static inline void* GetExternalPointerFromSmi(internal::Object* value) {
+ const intptr_t address = reinterpret_cast<intptr_t>(value);
+ return reinterpret_cast<void*>(address >> kPointerToSmiShift);
+ }
+
static inline void* GetExternalPointer(internal::Object* obj) {
if (HasSmiTag(obj)) {
- return obj;
+ return GetExternalPointerFromSmi(obj);
} else if (GetInstanceType(obj) == kProxyType) {
return ReadField<void*>(obj, kProxyProxyOffset);
} else {