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

src/platform-macos.cc

 // Copyright 2006-2008 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 226 matching lines @@
 #endif
     if (code_ptr == NULL) continue;
     const uintptr_t slide = _dyld_get_image_vmaddr_slide(i);
     const uintptr_t start = reinterpret_cast<uintptr_t>(code_ptr) + slide;
     LOG(SharedLibraryEvent(_dyld_get_image_name(i), start, start + size));
   }
 #endif  // ENABLE_LOGGING_AND_PROFILING
 }
 
 
+uint64_t OS::CpuFeaturesImpliedByPlatform() {
+  // MacOSX requires all these to install so we can assume they are present.
+  // These constants are defined by the CPUid instructions.
+  const uint64_t one = 1;
+  return (one << SSE2) | (one << CMOV) | (one << RDTSC) | (one << CPUID);
+}
+
+
 double OS::nan_value() {
   return NAN;
 }
 
 
 int OS::ActivationFrameAlignment() {
   // OS X activation frames must be 16 byte-aligned; see "Mac OS X ABI
   // Function Call Guide".
   return 16;
 }
@@ skipping 374 matching lines @@
 
   // Deallocate Mach port for thread.
   if (IsProfiling()) {
     mach_port_deallocate(data_->task_self_, data_->profiled_thread_);
   }
 }
 
 #endif  // ENABLE_LOGGING_AND_PROFILING
 
 } }  // namespace v8::internal