A64: Synchronize with r15545.

src/platform-win32.cc

Index: src/platform-win32.cc
diff --git a/src/platform-win32.cc b/src/platform-win32.cc
index 600962e2d152828cde066c31f485deabb022eafc..80bcaf92afdde9355cf2cbb554e375fd623b2a7d 100644
--- a/src/platform-win32.cc
+++ b/src/platform-win32.cc
@@ -147,11 +147,12 @@ double ceiling(double x) {
 
 static Mutex* limit_mutex = NULL;
 
-#if defined(V8_TARGET_ARCH_IA32)
+#if V8_TARGET_ARCH_IA32
 static void MemMoveWrapper(void* dest, const void* src, size_t size) {
   memmove(dest, src, size);
 }
 
+
 // Initialize to library version so we can call this at any time during startup.
 static OS::MemMoveFunction memmove_function = &MemMoveWrapper;
 
@@ -178,6 +179,7 @@ void init_modulo_function() {
   modulo_function = CreateModuloFunction();
 }
 
+
 double modulo(double x, double y) {
   // Note: here we rely on dependent reads being ordered. This is true
   // on all architectures we currently support.
@@ -321,6 +323,7 @@ class Time {
   TimeStamp time_;
 };
 
+
 // Static variables.
 bool Time::tz_initialized_ = false;
 TIME_ZONE_INFORMATION Time::tzinfo_;
@@ -580,7 +583,7 @@ void OS::PostSetUp() {
   // Math functions depend on CPU features therefore they are initialized after
   // CPU.
   MathSetup();
-#if defined(V8_TARGET_ARCH_IA32)
+#if V8_TARGET_ARCH_IA32
   OS::MemMoveFunction generated_memmove = CreateMemMoveFunction();
   if (generated_memmove != NULL) {
     memmove_function = generated_memmove;
@@ -616,6 +619,7 @@ double OS::TimeCurrentMillis() {
   return t.ToJSTime();
 }
 
+
 // Returns the tickcounter based on timeGetTime.
 int64_t OS::Ticks() {
   return timeGetTime() * 1000;  // Convert to microseconds.
@@ -1449,6 +1453,7 @@ int OS::StackWalk(Vector<OS::StackFrame> frames) {
   return frames_count;
 }
 
+
 // Restore warnings to previous settings.
 #pragma warning(pop)
 
@@ -1479,6 +1484,10 @@ double OS::nan_value() {
 int OS::ActivationFrameAlignment() {
 #ifdef _WIN64
   return 16;  // Windows 64-bit ABI requires the stack to be 16-byte aligned.
+#elif defined(__MINGW32__)
+  // With gcc 4.4 the tree vectorization optimizer can generate code
+  // that requires 16 byte alignment such as movdqa on x86.
+  return 16;
 #else
   return 8;  // Floating-point math runs faster with 8-byte alignment.
 #endif