Have the profiler load the correct registers on x64.

src/platform-linux.cc

Index: src/platform-linux.cc
diff --git a/src/platform-linux.cc b/src/platform-linux.cc
index c735cebfcf593acce35b2427008063241be0fd1b..d9f8c9c24efe1e65d654d144cd07b1d9b56f903a 100644
--- a/src/platform-linux.cc
+++ b/src/platform-linux.cc
@@ -600,14 +600,18 @@ static void ProfilerSignalHandler(int signal, siginfo_t* info, void* context) {
     // Extracting the sample from the context is extremely machine dependent.
     ucontext_t* ucontext = reinterpret_cast<ucontext_t*>(context);
     mcontext_t& mcontext = ucontext->uc_mcontext;
-#if defined(__arm__) || defined(__thumb__)
-    sample.pc = mcontext.gregs[R15];
-    sample.sp = mcontext.gregs[R13];
-    sample.fp = mcontext.gregs[R11];
-#else
+#if V8_HOST_ARCH_X86
     sample.pc = mcontext.gregs[REG_EIP];
     sample.sp = mcontext.gregs[REG_ESP];
     sample.fp = mcontext.gregs[REG_EBP];
+#elif V8_HOST_ARCH_X64
+    sample.pc = mcontext.gregs[REG_RIP];

[Lasse Reichstein, 2009/05/06 11:05:27]

Does the assignment compile, and throw away the upper half of the value
silently? If so, I'd prefer an UNIMPLEMENTED() in front of it with a comment
saying to not remove it unitl sample.pc allows 64 bits.

[Dean McNamee, 2009/05/06 11:07:15]

It does compile, but I'll just do UNIMPLEMENTED :\

On 2009/05/06 11:05:27, Lasse Reichstein wrote:

+    sample.sp = mcontext.gregs[REG_RSP];
+    sample.fp = mcontext.gregs[REG_RBP];
+#elif V8_HOST_ARCH_ARM
+    sample.pc = mcontext.gregs[R15];
+    sample.sp = mcontext.gregs[R13];
+    sample.fp = mcontext.gregs[R11];
 #endif
   }