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

src/base/atomicops_internals_mips64_gcc.h

-// Copyright 2010 the V8 project authors. All rights reserved.
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions are
-// met:
-//
-//     * Redistributions of source code must retain the above copyright
-//       notice, this list of conditions and the following disclaimer.
-//     * Redistributions in binary form must reproduce the above
-//       copyright notice, this list of conditions and the following
-//       disclaimer in the documentation and/or other materials provided
-//       with the distribution.
-//     * Neither the name of Google Inc. nor the names of its
-//       contributors may be used to endorse or promote products derived
-//       from this software without specific prior written permission.
-//
-// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-// This file is an internal atomic implementation, use atomicops.h instead.
-
-#ifndef V8_BASE_ATOMICOPS_INTERNALS_MIPS_GCC_H_
-#define V8_BASE_ATOMICOPS_INTERNALS_MIPS_GCC_H_
-
-namespace v8 {
-namespace base {
-
-// Atomically execute:
-//      result = *ptr;
-//      if (*ptr == old_value)
-//        *ptr = new_value;
-//      return result;
-//
-// I.e., replace "*ptr" with "new_value" if "*ptr" used to be "old_value".
-// Always return the old value of "*ptr"
-//
-// This routine implies no memory barriers.
-inline Atomic32 NoBarrier_CompareAndSwap(volatile Atomic32* ptr,
-                                         Atomic32 old_value,
-                                         Atomic32 new_value) {
-  Atomic32 prev, tmp;
-  __asm__ __volatile__(".set push\n"
-                       ".set noreorder\n"
-                       "1:\n"
-                       "ll %0, %5\n"  // prev = *ptr
-                       "bne %0, %3, 2f\n"  // if (prev != old_value) goto 2
-                       "move %2, %4\n"  // tmp = new_value
-                       "sc %2, %1\n"  // *ptr = tmp (with atomic check)
-                       "beqz %2, 1b\n"  // start again on atomic error
-                       "nop\n"  // delay slot nop
-                       "2:\n"
-                       ".set pop\n"
-                       : "=&r" (prev), "=m" (*ptr), "=&r" (tmp)
-                       : "r" (old_value), "r" (new_value), "m" (*ptr)
-                       : "memory");
-  return prev;
-}
-
-// Atomically store new_value into *ptr, returning the previous value held in
-// *ptr.  This routine implies no memory barriers.
-inline Atomic32 NoBarrier_AtomicExchange(volatile Atomic32* ptr,
-                                         Atomic32 new_value) {
-  Atomic32 temp, old;
-  __asm__ __volatile__(".set push\n"
-                       ".set noreorder\n"
-                       "1:\n"
-                       "ll %1, %2\n"  // old = *ptr
-                       "move %0, %3\n"  // temp = new_value
-                       "sc %0, %2\n"  // *ptr = temp (with atomic check)
-                       "beqz %0, 1b\n"  // start again on atomic error
-                       "nop\n"  // delay slot nop
-                       ".set pop\n"
-                       : "=&r" (temp), "=&r" (old), "=m" (*ptr)
-                       : "r" (new_value), "m" (*ptr)
-                       : "memory");
-
-  return old;
-}
-
-// Atomically increment *ptr by "increment".  Returns the new value of
-// *ptr with the increment applied.  This routine implies no memory barriers.
-inline Atomic32 NoBarrier_AtomicIncrement(volatile Atomic32* ptr,
-                                          Atomic32 increment) {
-  Atomic32 temp, temp2;
-
-  __asm__ __volatile__(
-      ".set push\n"
-      ".set noreorder\n"
-      "1:\n"
-      "ll %0, %2\n"        // temp = *ptr
-      "addu %1, %0, %3\n"  // temp2 = temp + increment
-      "sc %1, %2\n"        // *ptr = temp2 (with atomic check)
-      "beqz %1, 1b\n"      // start again on atomic error
-      "addu %1, %0, %3\n"  // temp2 = temp + increment
-      ".set pop\n"
-      : "=&r"(temp), "=&r"(temp2), "=ZC"(*ptr)
-      : "Ir"(increment), "m"(*ptr)
-      : "memory");
-  // temp2 now holds the final value.
-  return temp2;
-}
-
-inline Atomic32 Barrier_AtomicIncrement(volatile Atomic32* ptr,
-                                        Atomic32 increment) {
-  MemoryBarrier();
-  Atomic32 res = NoBarrier_AtomicIncrement(ptr, increment);
-  MemoryBarrier();
-  return res;
-}
-
-// "Acquire" operations
-// ensure that no later memory access can be reordered ahead of the operation.
-// "Release" operations ensure that no previous memory access can be reordered
-// after the operation.  "Barrier" operations have both "Acquire" and "Release"
-// semantics.   A MemoryBarrier() has "Barrier" semantics, but does no memory
-// access.
-inline Atomic32 Acquire_CompareAndSwap(volatile Atomic32* ptr,
-                                       Atomic32 old_value,
-                                       Atomic32 new_value) {
-  Atomic32 res = NoBarrier_CompareAndSwap(ptr, old_value, new_value);
-  MemoryBarrier();
-  return res;
-}
-
-inline Atomic32 Release_CompareAndSwap(volatile Atomic32* ptr,
-                                       Atomic32 old_value,
-                                       Atomic32 new_value) {
-  MemoryBarrier();
-  return NoBarrier_CompareAndSwap(ptr, old_value, new_value);
-}
-
-inline void NoBarrier_Store(volatile Atomic8* ptr, Atomic8 value) {
-  *ptr = value;
-}
-
-inline void NoBarrier_Store(volatile Atomic32* ptr, Atomic32 value) {
-  *ptr = value;
-}
-
-inline void MemoryBarrier() {
-  __asm__ __volatile__("sync" : : : "memory");
-}
-
-inline void Acquire_Store(volatile Atomic32* ptr, Atomic32 value) {
-  *ptr = value;
-  MemoryBarrier();
-}
-
-inline void Release_Store(volatile Atomic32* ptr, Atomic32 value) {
-  MemoryBarrier();
-  *ptr = value;
-}
-
-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;
-  MemoryBarrier();
-  return value;
-}
-
-inline Atomic32 Release_Load(volatile const Atomic32* ptr) {
-  MemoryBarrier();
-  return *ptr;
-}
-
-
-// 64-bit versions of the atomic ops.
-
-inline Atomic64 NoBarrier_CompareAndSwap(volatile Atomic64* ptr,
-                                         Atomic64 old_value,
-                                         Atomic64 new_value) {
-  Atomic64 prev, tmp;
-  __asm__ __volatile__(".set push\n"
-                       ".set noreorder\n"
-                       "1:\n"
-                       "lld %0, %5\n"  // prev = *ptr
-                       "bne %0, %3, 2f\n"  // if (prev != old_value) goto 2
-                       "move %2, %4\n"  // tmp = new_value
-                       "scd %2, %1\n"  // *ptr = tmp (with atomic check)
-                       "beqz %2, 1b\n"  // start again on atomic error
-                       "nop\n"  // delay slot nop
-                       "2:\n"
-                       ".set pop\n"
-                       : "=&r" (prev), "=m" (*ptr), "=&r" (tmp)
-                       : "r" (old_value), "r" (new_value), "m" (*ptr)
-                       : "memory");
-  return prev;
-}
-
-// Atomically store new_value into *ptr, returning the previous value held in
-// *ptr.  This routine implies no memory barriers.
-inline Atomic64 NoBarrier_AtomicExchange(volatile Atomic64* ptr,
-                                         Atomic64 new_value) {
-  Atomic64 temp, old;
-  __asm__ __volatile__(".set push\n"
-                       ".set noreorder\n"
-                       "1:\n"
-                       "lld %1, %2\n"  // old = *ptr
-                       "move %0, %3\n"  // temp = new_value
-                       "scd %0, %2\n"  // *ptr = temp (with atomic check)
-                       "beqz %0, 1b\n"  // start again on atomic error
-                       "nop\n"  // delay slot nop
-                       ".set pop\n"
-                       : "=&r" (temp), "=&r" (old), "=m" (*ptr)
-                       : "r" (new_value), "m" (*ptr)
-                       : "memory");
-
-  return old;
-}
-
-// Atomically increment *ptr by "increment".  Returns the new value of
-// *ptr with the increment applied.  This routine implies no memory barriers.
-inline Atomic64 NoBarrier_AtomicIncrement(volatile Atomic64* ptr,
-                                          Atomic64 increment) {
-  Atomic64 temp, temp2;
-
-  __asm__ __volatile__(
-      ".set push\n"
-      ".set noreorder\n"
-      "1:\n"
-      "lld %0, %2\n"        // temp = *ptr
-      "daddu %1, %0, %3\n"  // temp2 = temp + increment
-      "scd %1, %2\n"        // *ptr = temp2 (with atomic check)
-      "beqz %1, 1b\n"       // start again on atomic error
-      "daddu %1, %0, %3\n"  // temp2 = temp + increment
-      ".set pop\n"
-      : "=&r"(temp), "=&r"(temp2), "=ZC"(*ptr)
-      : "Ir"(increment), "m"(*ptr)
-      : "memory");
-  // temp2 now holds the final value.
-  return temp2;
-}
-
-inline Atomic64 Barrier_AtomicIncrement(volatile Atomic64* ptr,
-                                        Atomic64 increment) {
-  MemoryBarrier();
-  Atomic64 res = NoBarrier_AtomicIncrement(ptr, increment);
-  MemoryBarrier();
-  return res;
-}
-
-// "Acquire" operations
-// ensure that no later memory access can be reordered ahead of the operation.
-// "Release" operations ensure that no previous memory access can be reordered
-// after the operation.  "Barrier" operations have both "Acquire" and "Release"
-// semantics.   A MemoryBarrier() has "Barrier" semantics, but does no memory
-// access.
-inline Atomic64 Acquire_CompareAndSwap(volatile Atomic64* ptr,
-                                       Atomic64 old_value,
-                                       Atomic64 new_value) {
-  Atomic64 res = NoBarrier_CompareAndSwap(ptr, old_value, new_value);
-  MemoryBarrier();
-  return res;
-}
-
-inline Atomic64 Release_CompareAndSwap(volatile Atomic64* ptr,
-                                       Atomic64 old_value,
-                                       Atomic64 new_value) {
-  MemoryBarrier();
-  return NoBarrier_CompareAndSwap(ptr, old_value, new_value);
-}
-
-inline void NoBarrier_Store(volatile Atomic64* ptr, Atomic64 value) {
-  *ptr = value;
-}
-
-inline void Acquire_Store(volatile Atomic64* ptr, Atomic64 value) {
-  *ptr = value;
-  MemoryBarrier();
-}
-
-inline void Release_Store(volatile Atomic64* ptr, Atomic64 value) {
-  MemoryBarrier();
-  *ptr = value;
-}
-
-inline Atomic64 NoBarrier_Load(volatile const Atomic64* ptr) {
-  return *ptr;
-}
-
-inline Atomic64 Acquire_Load(volatile const Atomic64* ptr) {
-  Atomic64 value = *ptr;
-  MemoryBarrier();
-  return value;
-}
-
-inline Atomic64 Release_Load(volatile const Atomic64* ptr) {
-  MemoryBarrier();
-  return *ptr;
-}
-
-}  // namespace base
-}  // namespace v8
-
-#endif  // V8_BASE_ATOMICOPS_INTERNALS_MIPS_GCC_H_