Revert of 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_