Allow a platform to indicate that some CPU features are always...

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 558 matching lines @@
   // 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
+                  SAHF = 0};   // x86
+
 } }  // namespace v8::internal
 
 #endif  // V8_GLOBALS_H_