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

src/globals.h

 // Copyright 2006-2009 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 80 matching lines @@
 #define V8_PTR_PREFIX "ll"
 #else  // _MSC_VER
 #define V8_UINT64_C(x)  (x ## UL)
 #define V8_INT64_C(x)   (x ## L)
 #define V8_PTR_PREFIX "l"
 #endif  // _MSC_VER
 #else  // V8_HOST_ARCH_64_BIT
 #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"
 
 // Fix for Mac OS X defining uintptr_t as "unsigned long":
 #if defined(__APPLE__) && defined(__MACH__)
 #undef V8PRIxPTR
 #define V8PRIxPTR "lx"
 #endif
 
 #if defined(__APPLE__) && defined(__MACH__)
@@ skipping 198 matching lines @@
 // (allocated in the young generation if the object size and type
 // allows).
 enum PretenureFlag { NOT_TENURED, TENURED };
 
 enum GarbageCollector { SCAVENGER, MARK_COMPACTOR };
 
 enum Executability { NOT_EXECUTABLE, EXECUTABLE };
 
 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 };
 
 
 // A CodeDesc describes a buffer holding instructions and relocation
 // information. The instructions start at the beginning of the buffer
 // and grow forward, the relocation information starts at the end of
 // the buffer and grows backward.
 //
 //  |<--------------- buffer_size ---------------->|
 //  |<-- instr_size -->|        |<-- reloc_size -->|
@@ skipping 235 matching lines @@
 #if defined(__GNUC__) && !defined(DEBUG)
 #if (__GNUC__ >= 4)
 #define INLINE(header) inline header  __attribute__((always_inline))
 #else
 #define INLINE(header) inline __attribute__((always_inline)) header
 #endif
 #else
 #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.)
 enum CpuFeature { SSE3 = 32,   // x86
                   SSE2 = 26,   // x86
                   CMOV = 15,   // x86
                   RDTSC = 4,   // x86
                   CPUID = 10,  // x86
                   VFP3 = 1,    // ARM
                   ARMv7 = 2,   // ARM
                   SAHF = 0};   // x86
 
 } }  // namespace v8::internal
 
 #endif  // V8_GLOBALS_H_