diff --git a/src/globals.h b/src/globals.h
index efe0127..ad0539f 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -103,6 +103,10 @@
 #define V8PRIxPTR "lx"
 #endif
 
+#if defined(__APPLE__) && defined(__MACH__)
+#define USING_MAC_ABI
+#endif
+
 // Code-point values in Unicode 4.0 are 21 bits wide.
 typedef uint16_t uc16;
 typedef int32_t uc32;
@@ -170,6 +174,15 @@
 #endif
 
 
+// Constants relevant to double precision floating point numbers.
+
+// Quiet NaNs have bits 51 to 62 set, possibly the sign bit, and no
+// other bits set.
+const uint64_t kQuietNaNMask = static_cast<uint64_t>(0xfff) << 51;
+// If looking only at the top 32 bits, the QNaN mask is bits 19 to 30.
+const uint32_t kQuietNaNHighBitsMask = 0xfff << (51 - 32);
+
+
 // -----------------------------------------------------------------------------
 // Forward declarations for frequently used classes
 // (sorted alphabetically)
@@ -263,7 +276,9 @@
   LO_SPACE,             // Promoted large objects.
 
   FIRST_SPACE = NEW_SPACE,
-  LAST_SPACE = LO_SPACE
+  LAST_SPACE = LO_SPACE,
+  FIRST_PAGED_SPACE = OLD_POINTER_SPACE,
+  LAST_PAGED_SPACE = CELL_SPACE
 };
 const int kSpaceTagSize = 3;
 const int kSpaceTagMask = (1 << kSpaceTagSize) - 1;
@@ -279,6 +294,8 @@
 
 enum Executability { NOT_EXECUTABLE, EXECUTABLE };
 
+enum VisitMode { VISIT_ALL, VISIT_ONLY_STRONG };
+
 
 // A CodeDesc describes a buffer holding instructions and relocation
 // information. The instructions start at the beginning of the buffer
@@ -558,6 +575,17 @@
 }
 
 
+// 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
+                  SAHF = 0};   // x86
+
 } }  // namespace v8::internal
 
 #endif  // V8_GLOBALS_H_