Initial checkin of GCC 4.9.0 from trunk (r208799).

Change-Id: I48a3c08bb98542aa215912a75f03c0890e497dba

1 files changed, 133 insertions, 0 deletions

diff --git a/gcc-4.9/libsanitizer/sanitizer_common/sanitizer_atomic_clang.h b/gcc-4.9/libsanitizer/sanitizer_common/sanitizer_atomic_clang.h
new file mode 100644
index 000000000..88819e32a
--- /dev/null
+++ b/gcc-4.9/libsanitizer/sanitizer_common/sanitizer_atomic_clang.h
@@ -0,0 +1,133 @@
+//===-- sanitizer_atomic_clang.h --------------------------------*- C++ -*-===//
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of ThreadSanitizer/AddressSanitizer runtime.
+// Not intended for direct inclusion. Include sanitizer_atomic.h.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SANITIZER_ATOMIC_CLANG_H
+#define SANITIZER_ATOMIC_CLANG_H
+
+namespace __sanitizer {
+
+INLINE void atomic_signal_fence(memory_order) {
+  __asm__ __volatile__("" ::: "memory");
+}
+
+INLINE void atomic_thread_fence(memory_order) {
+  __sync_synchronize();
+}
+
+INLINE void proc_yield(int cnt) {
+  __asm__ __volatile__("" ::: "memory");
+#if defined(__i386__) || defined(__x86_64__)
+  for (int i = 0; i < cnt; i++)
+    __asm__ __volatile__("pause");
+#endif
+  __asm__ __volatile__("" ::: "memory");
+}
+
+template<typename T>
+INLINE typename T::Type atomic_load(
+    const volatile T *a, memory_order mo) {
+  DCHECK(mo & (memory_order_relaxed | memory_order_consume
+      | memory_order_acquire | memory_order_seq_cst));
+  DCHECK(!((uptr)a % sizeof(*a)));
+  typename T::Type v;
+  // FIXME:
+  // 64-bit atomic operations are not atomic on 32-bit platforms.
+  // The implementation lacks necessary memory fences on ARM/PPC.
+  // We would like to use compiler builtin atomic operations,
+  // but they are mostly broken:
+  // - they lead to vastly inefficient code generation
+  // (http://llvm.org/bugs/show_bug.cgi?id=17281)
+  // - 64-bit atomic operations are not implemented on x86_32
+  // (http://llvm.org/bugs/show_bug.cgi?id=15034)
+  // - they are not implemented on ARM
+  // error: undefined reference to '__atomic_load_4'
+  if (mo == memory_order_relaxed) {
+    v = a->val_dont_use;
+  } else {
+    atomic_signal_fence(memory_order_seq_cst);
+    v = a->val_dont_use;
+    atomic_signal_fence(memory_order_seq_cst);
+  }
+  return v;
+}
+
+template<typename T>
+INLINE void atomic_store(volatile T *a, typename T::Type v, memory_order mo) {
+  DCHECK(mo & (memory_order_relaxed | memory_order_release
+      | memory_order_seq_cst));
+  DCHECK(!((uptr)a % sizeof(*a)));
+  if (mo == memory_order_relaxed) {
+    a->val_dont_use = v;
+  } else {
+    atomic_signal_fence(memory_order_seq_cst);
+    a->val_dont_use = v;
+    atomic_signal_fence(memory_order_seq_cst);
+  }
+  if (mo == memory_order_seq_cst)
+    atomic_thread_fence(memory_order_seq_cst);
+}
+
+template<typename T>
+INLINE typename T::Type atomic_fetch_add(volatile T *a,
+    typename T::Type v, memory_order mo) {
+  (void)mo;
+  DCHECK(!((uptr)a % sizeof(*a)));
+  return __sync_fetch_and_add(&a->val_dont_use, v);
+}
+
+template<typename T>
+INLINE typename T::Type atomic_fetch_sub(volatile T *a,
+    typename T::Type v, memory_order mo) {
+  (void)mo;
+  DCHECK(!((uptr)a % sizeof(*a)));
+  return __sync_fetch_and_add(&a->val_dont_use, -v);
+}
+
+template<typename T>
+INLINE typename T::Type atomic_exchange(volatile T *a,
+    typename T::Type v, memory_order mo) {
+  DCHECK(!((uptr)a % sizeof(*a)));
+  if (mo & (memory_order_release | memory_order_acq_rel | memory_order_seq_cst))
+    __sync_synchronize();
+  v = __sync_lock_test_and_set(&a->val_dont_use, v);
+  if (mo == memory_order_seq_cst)
+    __sync_synchronize();
+  return v;
+}
+
+template<typename T>
+INLINE bool atomic_compare_exchange_strong(volatile T *a,
+                                           typename T::Type *cmp,
+                                           typename T::Type xchg,
+                                           memory_order mo) {
+  typedef typename T::Type Type;
+  Type cmpv = *cmp;
+  Type prev = __sync_val_compare_and_swap(&a->val_dont_use, cmpv, xchg);
+  if (prev == cmpv)
+    return true;
+  *cmp = prev;
+  return false;
+}
+
+template<typename T>
+INLINE bool atomic_compare_exchange_weak(volatile T *a,
+                                         typename T::Type *cmp,
+                                         typename T::Type xchg,
+                                         memory_order mo) {
+  return atomic_compare_exchange_strong(a, cmp, xchg, mo);
+}
+
+}  // namespace __sanitizer
+
+#undef ATOMIC_ORDER
+
+#endif  // SANITIZER_ATOMIC_CLANG_H