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- // -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*-
- /* Copyright (c) 2008, Google Inc.
- * 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.
- *
- * ---
- */
- // Implementation of atomic operations for ppc-linux. This file should not
- // be included directly. Clients should instead include
- // "base/atomicops.h".
- #ifndef BASE_ATOMICOPS_INTERNALS_LINUXPPC_H_
- #define BASE_ATOMICOPS_INTERNALS_LINUXPPC_H_
- typedef int32_t Atomic32;
- #ifdef __PPC64__
- #define BASE_HAS_ATOMIC64 1
- #endif
- namespace base {
- namespace subtle {
- static inline void _sync(void) {
- __asm__ __volatile__("sync": : : "memory");
- }
- static inline void _lwsync(void) {
- // gcc defines __NO_LWSYNC__ when appropriate; see
- // http://gcc.gnu.org/ml/gcc-patches/2006-11/msg01238.html
- #ifdef __NO_LWSYNC__
- __asm__ __volatile__("msync": : : "memory");
- #else
- __asm__ __volatile__("lwsync": : : "memory");
- #endif
- }
- static inline void _isync(void) {
- __asm__ __volatile__("isync": : : "memory");
- }
- static inline Atomic32 OSAtomicAdd32(Atomic32 amount, Atomic32 *value) {
- Atomic32 t;
- __asm__ __volatile__(
- "1: lwarx %0,0,%3\n\
- add %0,%2,%0\n\
- stwcx. %0,0,%3 \n\
- bne- 1b"
- : "=&r" (t), "+m" (*value)
- : "r" (amount), "r" (value)
- : "cc");
- return t;
- }
- static inline Atomic32 OSAtomicAdd32Barrier(Atomic32 amount, Atomic32 *value) {
- Atomic32 t;
- _lwsync();
- t = OSAtomicAdd32(amount, value);
- // This is based on the code snippet in the architecture manual (Vol
- // 2, Appendix B). It's a little tricky: correctness depends on the
- // fact that the code right before this (in OSAtomicAdd32) has a
- // conditional branch with a data dependency on the update.
- // Otherwise, we'd have to use sync.
- _isync();
- return t;
- }
- static inline bool OSAtomicCompareAndSwap32(Atomic32 old_value,
- Atomic32 new_value,
- Atomic32 *value) {
- Atomic32 prev;
- __asm__ __volatile__(
- "1: lwarx %0,0,%2\n\
- cmpw 0,%0,%3\n\
- bne- 2f\n\
- stwcx. %4,0,%2\n\
- bne- 1b\n\
- 2:"
- : "=&r" (prev), "+m" (*value)
- : "r" (value), "r" (old_value), "r" (new_value)
- : "cc");
- return prev == old_value;
- }
- static inline Atomic32 OSAtomicCompareAndSwap32Acquire(Atomic32 old_value,
- Atomic32 new_value,
- Atomic32 *value) {
- Atomic32 t;
- t = OSAtomicCompareAndSwap32(old_value, new_value, value);
- // This is based on the code snippet in the architecture manual (Vol
- // 2, Appendix B). It's a little tricky: correctness depends on the
- // fact that the code right before this (in
- // OSAtomicCompareAndSwap32) has a conditional branch with a data
- // dependency on the update. Otherwise, we'd have to use sync.
- _isync();
- return t;
- }
- static inline Atomic32 OSAtomicCompareAndSwap32Release(Atomic32 old_value,
- Atomic32 new_value,
- Atomic32 *value) {
- _lwsync();
- return OSAtomicCompareAndSwap32(old_value, new_value, value);
- }
- typedef int64_t Atomic64;
- inline void MemoryBarrier() {
- // This can't be _lwsync(); we need to order the immediately
- // preceding stores against any load that may follow, but lwsync
- // doesn't guarantee that.
- _sync();
- }
- // 32-bit Versions.
- inline Atomic32 NoBarrier_CompareAndSwap(volatile Atomic32 *ptr,
- Atomic32 old_value,
- Atomic32 new_value) {
- Atomic32 prev_value;
- do {
- if (OSAtomicCompareAndSwap32(old_value, new_value,
- const_cast<Atomic32*>(ptr))) {
- return old_value;
- }
- prev_value = *ptr;
- } while (prev_value == old_value);
- return prev_value;
- }
- inline Atomic32 NoBarrier_AtomicExchange(volatile Atomic32 *ptr,
- Atomic32 new_value) {
- Atomic32 old_value;
- do {
- old_value = *ptr;
- } while (!OSAtomicCompareAndSwap32(old_value, new_value,
- const_cast<Atomic32*>(ptr)));
- return old_value;
- }
- inline Atomic32 Acquire_AtomicExchange(volatile Atomic32 *ptr,
- Atomic32 new_value) {
- Atomic32 old_value;
- do {
- old_value = *ptr;
- } while (!OSAtomicCompareAndSwap32Acquire(old_value, new_value,
- const_cast<Atomic32*>(ptr)));
- return old_value;
- }
- inline Atomic32 Release_AtomicExchange(volatile Atomic32 *ptr,
- Atomic32 new_value) {
- Atomic32 old_value;
- do {
- old_value = *ptr;
- } while (!OSAtomicCompareAndSwap32Release(old_value, new_value,
- const_cast<Atomic32*>(ptr)));
- return old_value;
- }
- inline Atomic32 Acquire_CompareAndSwap(volatile Atomic32 *ptr,
- Atomic32 old_value,
- Atomic32 new_value) {
- Atomic32 prev_value;
- do {
- if (OSAtomicCompareAndSwap32Acquire(old_value, new_value,
- const_cast<Atomic32*>(ptr))) {
- return old_value;
- }
- prev_value = *ptr;
- } while (prev_value == old_value);
- return prev_value;
- }
- inline Atomic32 Release_CompareAndSwap(volatile Atomic32 *ptr,
- Atomic32 old_value,
- Atomic32 new_value) {
- Atomic32 prev_value;
- do {
- if (OSAtomicCompareAndSwap32Release(old_value, new_value,
- const_cast<Atomic32*>(ptr))) {
- return old_value;
- }
- prev_value = *ptr;
- } while (prev_value == old_value);
- return prev_value;
- }
- #ifdef __PPC64__
- // 64-bit Versions.
- static inline Atomic64 OSAtomicAdd64(Atomic64 amount, Atomic64 *value) {
- Atomic64 t;
- __asm__ __volatile__(
- "1: ldarx %0,0,%3\n\
- add %0,%2,%0\n\
- stdcx. %0,0,%3 \n\
- bne- 1b"
- : "=&r" (t), "+m" (*value)
- : "r" (amount), "r" (value)
- : "cc");
- return t;
- }
- static inline Atomic64 OSAtomicAdd64Barrier(Atomic64 amount, Atomic64 *value) {
- Atomic64 t;
- _lwsync();
- t = OSAtomicAdd64(amount, value);
- // This is based on the code snippet in the architecture manual (Vol
- // 2, Appendix B). It's a little tricky: correctness depends on the
- // fact that the code right before this (in OSAtomicAdd64) has a
- // conditional branch with a data dependency on the update.
- // Otherwise, we'd have to use sync.
- _isync();
- return t;
- }
- static inline bool OSAtomicCompareAndSwap64(Atomic64 old_value,
- Atomic64 new_value,
- Atomic64 *value) {
- Atomic64 prev;
- __asm__ __volatile__(
- "1: ldarx %0,0,%2\n\
- cmpd 0,%0,%3\n\
- bne- 2f\n\
- stdcx. %4,0,%2\n\
- bne- 1b\n\
- 2:"
- : "=&r" (prev), "+m" (*value)
- : "r" (value), "r" (old_value), "r" (new_value)
- : "cc");
- return prev == old_value;
- }
- static inline Atomic64 OSAtomicCompareAndSwap64Acquire(Atomic64 old_value,
- Atomic64 new_value,
- Atomic64 *value) {
- Atomic64 t;
- t = OSAtomicCompareAndSwap64(old_value, new_value, value);
- // This is based on the code snippet in the architecture manual (Vol
- // 2, Appendix B). It's a little tricky: correctness depends on the
- // fact that the code right before this (in
- // OSAtomicCompareAndSwap64) has a conditional branch with a data
- // dependency on the update. Otherwise, we'd have to use sync.
- _isync();
- return t;
- }
- static inline Atomic64 OSAtomicCompareAndSwap64Release(Atomic64 old_value,
- Atomic64 new_value,
- Atomic64 *value) {
- _lwsync();
- return OSAtomicCompareAndSwap64(old_value, new_value, value);
- }
- inline Atomic64 NoBarrier_CompareAndSwap(volatile Atomic64 *ptr,
- Atomic64 old_value,
- Atomic64 new_value) {
- Atomic64 prev_value;
- do {
- if (OSAtomicCompareAndSwap64(old_value, new_value,
- const_cast<Atomic64*>(ptr))) {
- return old_value;
- }
- prev_value = *ptr;
- } while (prev_value == old_value);
- return prev_value;
- }
- inline Atomic64 NoBarrier_AtomicExchange(volatile Atomic64 *ptr,
- Atomic64 new_value) {
- Atomic64 old_value;
- do {
- old_value = *ptr;
- } while (!OSAtomicCompareAndSwap64(old_value, new_value,
- const_cast<Atomic64*>(ptr)));
- return old_value;
- }
- inline Atomic64 Acquire_AtomicExchange(volatile Atomic64 *ptr,
- Atomic64 new_value) {
- Atomic64 old_value;
- do {
- old_value = *ptr;
- } while (!OSAtomicCompareAndSwap64Acquire(old_value, new_value,
- const_cast<Atomic64*>(ptr)));
- return old_value;
- }
- inline Atomic64 Release_AtomicExchange(volatile Atomic64 *ptr,
- Atomic64 new_value) {
- Atomic64 old_value;
- do {
- old_value = *ptr;
- } while (!OSAtomicCompareAndSwap64Release(old_value, new_value,
- const_cast<Atomic64*>(ptr)));
- return old_value;
- }
- inline Atomic64 Acquire_CompareAndSwap(volatile Atomic64 *ptr,
- Atomic64 old_value,
- Atomic64 new_value) {
- Atomic64 prev_value;
- do {
- if (OSAtomicCompareAndSwap64Acquire(old_value, new_value,
- const_cast<Atomic64*>(ptr))) {
- return old_value;
- }
- prev_value = *ptr;
- } while (prev_value == old_value);
- return prev_value;
- }
- inline Atomic64 Release_CompareAndSwap(volatile Atomic64 *ptr,
- Atomic64 old_value,
- Atomic64 new_value) {
- Atomic64 prev_value;
- do {
- if (OSAtomicCompareAndSwap64Release(old_value, new_value,
- const_cast<Atomic64*>(ptr))) {
- return old_value;
- }
- prev_value = *ptr;
- } while (prev_value == old_value);
- return prev_value;
- }
- #endif
- inline void NoBarrier_Store(volatile Atomic32 *ptr, Atomic32 value) {
- *ptr = value;
- }
- inline void Acquire_Store(volatile Atomic32 *ptr, Atomic32 value) {
- *ptr = value;
- // This can't be _lwsync(); we need to order the immediately
- // preceding stores against any load that may follow, but lwsync
- // doesn't guarantee that.
- _sync();
- }
- inline void Release_Store(volatile Atomic32 *ptr, Atomic32 value) {
- _lwsync();
- *ptr = value;
- }
- inline Atomic32 NoBarrier_Load(volatile const Atomic32 *ptr) {
- return *ptr;
- }
- inline Atomic32 Acquire_Load(volatile const Atomic32 *ptr) {
- Atomic32 value = *ptr;
- _lwsync();
- return value;
- }
- inline Atomic32 Release_Load(volatile const Atomic32 *ptr) {
- // This can't be _lwsync(); we need to order the immediately
- // preceding stores against any load that may follow, but lwsync
- // doesn't guarantee that.
- _sync();
- return *ptr;
- }
- #ifdef __PPC64__
- // 64-bit Versions.
- inline void NoBarrier_Store(volatile Atomic64 *ptr, Atomic64 value) {
- *ptr = value;
- }
- inline void Acquire_Store(volatile Atomic64 *ptr, Atomic64 value) {
- *ptr = value;
- // This can't be _lwsync(); we need to order the immediately
- // preceding stores against any load that may follow, but lwsync
- // doesn't guarantee that.
- _sync();
- }
- inline void Release_Store(volatile Atomic64 *ptr, Atomic64 value) {
- _lwsync();
- *ptr = value;
- }
- inline Atomic64 NoBarrier_Load(volatile const Atomic64 *ptr) {
- return *ptr;
- }
- inline Atomic64 Acquire_Load(volatile const Atomic64 *ptr) {
- Atomic64 value = *ptr;
- _lwsync();
- return value;
- }
- inline Atomic64 Release_Load(volatile const Atomic64 *ptr) {
- // This can't be _lwsync(); we need to order the immediately
- // preceding stores against any load that may follow, but lwsync
- // doesn't guarantee that.
- _sync();
- return *ptr;
- }
- #endif
- } // namespace base::subtle
- } // namespace base
- #endif // BASE_ATOMICOPS_INTERNALS_LINUXPPC_H_
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