Reland Update implementation of atomics with latest Chromium version but use compiler builtin atomi…

src/base/atomicops_internals_x86_msvc.h

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// This file is an internal atomic implementation, use atomicops.h instead.
+// This file is an internal atomic implementation, use base/atomicops.h instead.
 
 #ifndef V8_BASE_ATOMICOPS_INTERNALS_X86_MSVC_H_
 #define V8_BASE_ATOMICOPS_INTERNALS_X86_MSVC_H_
 
 #include "src/base/macros.h"
 #include "src/base/win32-headers.h"
 
 #if defined(V8_HOST_ARCH_64_BIT)
 // windows.h #defines this (only on x64). This causes problems because the
 // public API also uses MemoryBarrier at the public name for this fence. So, on
 // X64, undef it, and call its documented
 // (http://msdn.microsoft.com/en-us/library/windows/desktop/ms684208.aspx)
 // implementation directly.
 #undef MemoryBarrier
 #endif
 
 namespace v8 {
 namespace base {
 
 inline Atomic32 NoBarrier_CompareAndSwap(volatile Atomic32* ptr,
                                          Atomic32 old_value,
                                          Atomic32 new_value) {
   LONG result = InterlockedCompareExchange(
-      reinterpret_cast<volatile LONG*>(ptr),
-      static_cast<LONG>(new_value),
+      reinterpret_cast<volatile LONG*>(ptr), static_cast<LONG>(new_value),
       static_cast<LONG>(old_value));
   return static_cast<Atomic32>(result);
 }
 
 inline Atomic32 NoBarrier_AtomicExchange(volatile Atomic32* ptr,
                                          Atomic32 new_value) {
-  LONG result = InterlockedExchange(
-      reinterpret_cast<volatile LONG*>(ptr),
-      static_cast<LONG>(new_value));
+  LONG result = InterlockedExchange(reinterpret_cast<volatile LONG*>(ptr),
+                                    static_cast<LONG>(new_value));
   return static_cast<Atomic32>(result);
 }
 
 inline Atomic32 Barrier_AtomicIncrement(volatile Atomic32* ptr,
                                         Atomic32 increment) {
-  return InterlockedExchangeAdd(
-      reinterpret_cast<volatile LONG*>(ptr),
-      static_cast<LONG>(increment)) + increment;
+  return InterlockedExchangeAdd(reinterpret_cast<volatile LONG*>(ptr),
+                                static_cast<LONG>(increment)) +
+         increment;
 }
 
 inline Atomic32 NoBarrier_AtomicIncrement(volatile Atomic32* ptr,
                                           Atomic32 increment) {
   return Barrier_AtomicIncrement(ptr, increment);
 }
 
-#if !(defined(_MSC_VER) && _MSC_VER >= 1400)
-#error "We require at least vs2005 for MemoryBarrier"
-#endif
 inline void MemoryBarrier() {
 #if defined(V8_HOST_ARCH_64_BIT)
   // See #undef and note at the top of this file.
   __faststorefence();
 #else
   // We use MemoryBarrier from WinNT.h
   ::MemoryBarrier();
 #endif
 }
 
@@ skipping 10 matching lines @@
 }
 
 inline void NoBarrier_Store(volatile Atomic8* ptr, Atomic8 value) {
   *ptr = value;
 }
 
 inline void NoBarrier_Store(volatile Atomic32* ptr, Atomic32 value) {
   *ptr = value;
 }
 
-inline void Acquire_Store(volatile Atomic32* ptr, Atomic32 value) {
-  NoBarrier_AtomicExchange(ptr, value);
-              // acts as a barrier in this implementation
-}
-
 inline void Release_Store(volatile Atomic32* ptr, Atomic32 value) {
   *ptr = value;  // works w/o barrier for current Intel chips as of June 2005
   // See comments in Atomic64 version of Release_Store() below.
 }
 
 inline Atomic8 NoBarrier_Load(volatile const Atomic8* ptr) {
   return *ptr;
 }
 
 inline Atomic32 NoBarrier_Load(volatile const Atomic32* ptr) {
   return *ptr;
 }
 
 inline Atomic32 Acquire_Load(volatile const Atomic32* ptr) {
   Atomic32 value = *ptr;
   return value;
 }
 
-inline Atomic32 Release_Load(volatile const Atomic32* ptr) {
-  MemoryBarrier();
-  return *ptr;
-}
-
 #if defined(_WIN64)
 
 // 64-bit low-level operations on 64-bit platform.
 
-STATIC_ASSERT(sizeof(Atomic64) == sizeof(PVOID));
+static_assert(sizeof(Atomic64) == sizeof(PVOID), "atomic word is atomic");
 
 inline Atomic64 NoBarrier_CompareAndSwap(volatile Atomic64* ptr,
                                          Atomic64 old_value,
                                          Atomic64 new_value) {
   PVOID result = InterlockedCompareExchangePointer(
     reinterpret_cast<volatile PVOID*>(ptr),
     reinterpret_cast<PVOID>(new_value), reinterpret_cast<PVOID>(old_value));
   return reinterpret_cast<Atomic64>(result);
 }
 
@@ skipping 14 matching lines @@
 
 inline Atomic64 NoBarrier_AtomicIncrement(volatile Atomic64* ptr,
                                           Atomic64 increment) {
   return Barrier_AtomicIncrement(ptr, increment);
 }
 
 inline void NoBarrier_Store(volatile Atomic64* ptr, Atomic64 value) {
   *ptr = value;
 }
 
-inline void Acquire_Store(volatile Atomic64* ptr, Atomic64 value) {
-  NoBarrier_AtomicExchange(ptr, value);
-              // acts as a barrier in this implementation
-}
-
 inline void Release_Store(volatile Atomic64* ptr, Atomic64 value) {
   *ptr = value;  // works w/o barrier for current Intel chips as of June 2005
 
   // When new chips come out, check:
   //  IA-32 Intel Architecture Software Developer's Manual, Volume 3:
   //  System Programming Guide, Chatper 7: Multiple-processor management,
   //  Section 7.2, Memory Ordering.
   // Last seen at:
   //   http://developer.intel.com/design/pentium4/manuals/index_new.htm
 }
 
 inline Atomic64 NoBarrier_Load(volatile const Atomic64* ptr) {
   return *ptr;
 }
 
 inline Atomic64 Acquire_Load(volatile const Atomic64* ptr) {
   Atomic64 value = *ptr;
   return value;
 }
 
-inline Atomic64 Release_Load(volatile const Atomic64* ptr) {
-  MemoryBarrier();
-  return *ptr;
-}
-
 inline Atomic64 Acquire_CompareAndSwap(volatile Atomic64* ptr,
                                        Atomic64 old_value,
                                        Atomic64 new_value) {
   return NoBarrier_CompareAndSwap(ptr, old_value, new_value);
 }
 
 inline Atomic64 Release_CompareAndSwap(volatile Atomic64* ptr,
                                        Atomic64 old_value,
                                        Atomic64 new_value) {
   return NoBarrier_CompareAndSwap(ptr, old_value, new_value);
 }
 
 
 #endif  // defined(_WIN64)
 
 }  // namespace base
 }  // namespace v8
 
 #endif  // V8_BASE_ATOMICOPS_INTERNALS_X86_MSVC_H_