Merge bleeding_edge from version 2.1.3 up to revision 4205...

src/globals.h

Index: src/globals.h
===================================================================
--- src/globals.h	(revision 4205)
+++ src/globals.h	(working copy)
@@ -98,6 +98,11 @@
 #define V8_PTR_PREFIX ""
 #endif  // V8_HOST_ARCH_64_BIT
 
+// The following macro works on both 32 and 64-bit platforms.
+// Usage: instead of writing 0x1234567890123456
+//      write V8_2PART_UINT64_C(0x12345678,90123456);
+#define V8_2PART_UINT64_C(a, b) (((static_cast<uint64_t>(a) << 32) + 0x##b##u))
+
 #define V8PRIxPTR V8_PTR_PREFIX "x"
 #define V8PRIdPTR V8_PTR_PREFIX "d"
 
@@ -316,8 +321,7 @@
 
 enum VisitMode { VISIT_ALL, VISIT_ALL_IN_SCAVENGE, VISIT_ONLY_STRONG };
 
-// Flag indicating whether code is built in to the VM (one of the natives
-// files).
+// Flag indicating whether code is built into the VM (one of the natives files).
 enum NativesFlag { NOT_NATIVES_CODE, NATIVES_CODE };
 
 
@@ -573,42 +577,6 @@
 #define INLINE(header) inline header
 #endif
 
-// The type-based aliasing rule allows the compiler to assume that pointers of
-// different types (for some definition of different) never alias each other.
-// Thus the following code does not work:
-//
-// float f = foo();
-// int fbits = *(int*)(&f);
-//
-// The compiler 'knows' that the int pointer can't refer to f since the types
-// don't match, so the compiler may cache f in a register, leaving random data
-// in fbits.  Using C++ style casts makes no difference, however a pointer to
-// char data is assumed to alias any other pointer.  This is the 'memcpy
-// exception'.
-//
-// Bit_cast uses the memcpy exception to move the bits from a variable of one
-// type of a variable of another type.  Of course the end result is likely to
-// be implementation dependent.  Most compilers (gcc-4.2 and MSVC 2005)
-// will completely optimize bit_cast away.
-//
-// There is an additional use for bit_cast.
-// Recent gccs will warn when they see casts that may result in breakage due to
-// the type-based aliasing rule.  If you have checked that there is no breakage
-// you can use bit_cast to cast one pointer type to another.  This confuses gcc
-// enough that it can no longer see that you have cast one pointer type to
-// another thus avoiding the warning.
-template <class Dest, class Source>
-inline Dest bit_cast(const Source& source) {
-  // Compile time assertion: sizeof(Dest) == sizeof(Source)
-  // A compile error here means your Dest and Source have different sizes.
-  typedef char VerifySizesAreEqual[sizeof(Dest) == sizeof(Source) ? 1 : -1];
-
-  Dest dest;
-  memcpy(&dest, &source, sizeof(dest));
-  return dest;
-}
-
-
 // Feature flags bit positions. They are mostly based on the CPUID spec.
 // (We assign CPUID itself to one of the currently reserved bits --
 // feel free to change this if needed.)