Add X32 port into V8

test/cctest/test-lockers.cc

 // Copyright 2007-2011 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 228 matching lines @@
     }
     isolate->Dispose();
   }
  private:
 };
 
 // Run many threads each accessing its own isolate without locking
 TEST(MultithreadedParallelIsolates) {
 #if V8_TARGET_ARCH_ARM || V8_TARGET_ARCH_MIPS
   const int kNThreads = 10;
+#elif V8_TARGET_ARCH_X32
+  const int kNThreads = 4;

[danno, 2013/07/17 13:33:21]

Why is this special handling of x32 needed? I would think you either want a
"mobile" mode (like and the same as ARM and MIPS) or "desktop" mode (everything
else), so folding into either the = 10 or = 40 case.

[haitao.feng, 2013/07/18 10:04:09]

This is related to the code range feature. We used code range and set it to
256M. When there are 10 threads, they will use at least 2.56G memory when they
are all live.  An alternative solution is to use MAP_32BIT flag when doing mmap
(supported by X32 linux kernel) but the drawback is that we could only use <1G
memory space. Here is the link of this discussion 
https://code.google.com/p/v8/issues/detail?id=2473#c18

 #else
   const int kNThreads = 50;
 #endif
   i::List<JoinableThread*> threads(kNThreads);
   for (int i = 0; i < kNThreads; i++) {
     threads.Add(new IsolateNonlockingThread());
   }
   StartJoinAndDeleteThreads(threads);
 }
 
@@ skipping 435 matching lines @@
  private:
   int count_;
   const char** extension_names_;
 };
 
 // Test installing extensions in separate isolates concurrently.
 // http://code.google.com/p/v8/issues/detail?id=1821
 TEST(ExtensionsRegistration) {
 #if V8_TARGET_ARCH_ARM || V8_TARGET_ARCH_MIPS
   const int kNThreads = 10;
+#elif V8_TARGET_ARCH_X32

[danno, 2013/07/17 13:33:21]

Why is this special handling of x32 needed? I would think you either want a
"mobile" mode (like and the same as ARM and MIPS) or "desktop" mode (everything
else), so folding into either the = 10 or = 40 case.

+  const int kNThreads = 4;
 #else
   const int kNThreads = 40;
 #endif
   v8::RegisterExtension(new v8::Extension("test0",
                                           kSimpleExtensionSource));
   v8::RegisterExtension(new v8::Extension("test1",
                                           kSimpleExtensionSource));
   v8::RegisterExtension(new v8::Extension("test2",
                                           kSimpleExtensionSource));
   v8::RegisterExtension(new v8::Extension("test3",
                                           kSimpleExtensionSource));
   v8::RegisterExtension(new v8::Extension("test4",
                                           kSimpleExtensionSource));
   v8::RegisterExtension(new v8::Extension("test5",
                                           kSimpleExtensionSource));
   v8::RegisterExtension(new v8::Extension("test6",
                                           kSimpleExtensionSource));
   v8::RegisterExtension(new v8::Extension("test7",
                                           kSimpleExtensionSource));
   const char* extension_names[] = { "test0", "test1",
                                     "test2", "test3", "test4",
                                     "test5", "test6", "test7" };
   i::List<JoinableThread*> threads(kNThreads);
   for (int i = 0; i < kNThreads; i++) {
     threads.Add(new IsolateGenesisThread(8, extension_names));
   }
   StartJoinAndDeleteThreads(threads);
 }