Don't duplicate OS::ActivationFrameAlignment() for every POSIX platform.

R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/20283002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15876 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/platform-cygwin.cc

@@ -55,13 +55,6 @@ namespace internal {
 static Mutex* limit_mutex = NULL;
 
 
-int OS::ActivationFrameAlignment() {
-  // With gcc 4.4 the tree vectorization optimizer can generate code
-  // that requires 16 byte alignment such as movdqa on x86.
-  return 16;
-}
-
-
 const char* OS::LocalTimezone(double time) {
   if (std::isnan(time)) return "";
   time_t tv = static_cast<time_t>(floor(time/msPerSecond));

src/platform-freebsd.cc

@@ -66,12 +66,6 @@ namespace internal {
 static Mutex* limit_mutex = NULL;
 
 
-int OS::ActivationFrameAlignment() {
-  // 16 byte alignment on FreeBSD
-  return 16;
-}
-
-
 const char* OS::LocalTimezone(double time) {
   if (std::isnan(time)) return "";
   time_t tv = static_cast<time_t>(floor(time/msPerSecond));

src/platform-linux.cc

@@ -308,20 +308,6 @@ bool OS::MipsCpuHasFeature(CpuFeature feature) {
 #endif  // def __mips__
 
 
-int OS::ActivationFrameAlignment() {
-#if V8_TARGET_ARCH_ARM
-  // On EABI ARM targets this is required for fp correctness in the
-  // runtime system.
-  return 8;
-#elif V8_TARGET_ARCH_MIPS
-  return 8;
-#endif
-  // With gcc 4.4 the tree vectorization optimizer can generate code
-  // that requires 16 byte alignment such as movdqa on x86.
-  return 16;
-}
-
-
 const char* OS::LocalTimezone(double time) {
   if (std::isnan(time)) return "";
   time_t tv = static_cast<time_t>(floor(time/msPerSecond));

src/platform-macos.cc

@@ -231,13 +231,6 @@ void OS::SignalCodeMovingGC() {
 }
 
 
-int OS::ActivationFrameAlignment() {
-  // OS X activation frames must be 16 byte-aligned; see "Mac OS X ABI
-  // Function Call Guide".
-  return 16;
-}
-
-
 const char* OS::LocalTimezone(double time) {
   if (std::isnan(time)) return "";
   time_t tv = static_cast<time_t>(floor(time/msPerSecond));

src/platform-openbsd.cc

@@ -64,13 +64,6 @@ namespace internal {
 static Mutex* limit_mutex = NULL;
 
 
-int OS::ActivationFrameAlignment() {
-  // With gcc 4.4 the tree vectorization optimizer can generate code
-  // that requires 16 byte alignment such as movdqa on x86.
-  return 16;
-}
-
-
 const char* OS::LocalTimezone(double time) {
   if (std::isnan(time)) return "";
   time_t tv = static_cast<time_t>(floor(time/msPerSecond));

src/platform-posix.cc

@@ -101,6 +101,24 @@ intptr_t OS::MaxVirtualMemory() {
 }
 
 
+int OS::ActivationFrameAlignment() {
+#if V8_TARGET_ARCH_ARM
+  // On EABI ARM targets this is required for fp correctness in the
+  // runtime system.
+  return 8;
+#elif V8_TARGET_ARCH_MIPS
+  return 8;
+#else
+  // Otherwise we just assume 16 byte alignment, i.e.:
+  // - With gcc 4.4 the tree vectorization optimizer can generate code
+  //   that requires 16 byte alignment such as movdqa on x86.
+  // - Mac OS X and Solaris (64-bit) activation frames must be 16 byte-aligned;
+  //   see "Mac OS X ABI Function Call Guide"
+  return 16;
+#endif
+}
+
+
 intptr_t OS::CommitPageSize() {
   static intptr_t page_size = getpagesize();
   return page_size;

src/platform-solaris.cc

@@ -84,12 +84,6 @@ namespace internal {
 static Mutex* limit_mutex = NULL;
 
 
-int OS::ActivationFrameAlignment() {
-  // GCC generates code that requires 16 byte alignment such as movdqa.
-  return Max(STACK_ALIGN, 16);
-}
-
-
 const char* OS::LocalTimezone(double time) {
   if (std::isnan(time)) return "";
   time_t tv = static_cast<time_t>(floor(time/msPerSecond));