[Isolates] Merge from bleeding_edge, revisions 5934-6100.

src/platform-linux.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 119 matching lines @@
       }
     }
   }
   fclose(f);
 
   // Did not find string in the proc file.
   return false;
 }
 
 bool OS::ArmCpuHasFeature(CpuFeature feature) {
-  const int max_items = 2;
-  const char* search_strings[max_items] = { NULL, NULL };
-  int search_items = 0;
+  const char* search_string = NULL;
   // Simple detection of VFP at runtime for Linux.
   // It is based on /proc/cpuinfo, which reveals hardware configuration
   // to user-space applications.  According to ARM (mid 2009), no similar
   // facility is universally available on the ARM architectures,
   // so it's up to individual OSes to provide such.
   switch (feature) {
     case VFP3:
-      search_strings[0] = "vfpv3";
-      // Some old kernels will report vfp for A8, not vfpv3, so we check for
-      // A8 explicitely. The cpuinfo file report the CPU Part which for Cortex
-      // A8 is 0xc08.
-      search_strings[1] = "0xc08";
-      search_items = 2;
-      ASSERT(search_items <= max_items);
+      search_string = "vfpv3";
       break;
     case ARMv7:
-      search_strings[0] = "ARMv7" ;
-      search_items = 1;
-      ASSERT(search_items <= max_items);
+      search_string = "ARMv7";
       break;
     default:
       UNREACHABLE();
   }
 
-  for (int i = 0; i < search_items; ++i) {
-    if (CPUInfoContainsString(search_strings[i])) {
+  if (CPUInfoContainsString(search_string)) {
+    return true;
+  }
+
+  if (feature == VFP3) {
+    // Some old kernels will report vfp not vfpv3. Here we make a last attempt
+    // to detect vfpv3 by checking for vfp *and* neon, since neon is only
+    // available on architectures with vfpv3.
+    // Checking neon on its own is not enough as it is possible to have neon
+    // without vfp.
+    if (CPUInfoContainsString("vfp") && CPUInfoContainsString("neon")) {
       return true;
     }
   }
 
   return false;
 }
 #endif  // def __arm__
 
 
 int OS::ActivationFrameAlignment() {
@@ skipping 817 matching lines @@
 
 void Sampler::Stop() {
   ASSERT(IsActive());
   SignalSender::RemoveActiveSampler(this);
   SetActive(false);
 }
 
 #endif  // ENABLE_LOGGING_AND_PROFILING
 
 } }  // namespace v8::internal