From ff156e4863c36c08814bfda08e60ff58f6a6cefc Mon Sep 17 00:00:00 2001 From: Brian Silverman Date: Wed, 9 Sep 2015 18:30:55 -0400 Subject: [PATCH] Add atomics support for 32-bit PPC. This was originally submitted as a patch on the Google Code issue tracker, but the original author didn't submit a pull request. They did, however, give permission for somebody else to do so. I cleaned up a few things myself and am now submitting it. I can't find any record of what the original patch was, but there is a copy of the discussion at . Fixes google/protobuf#581 --- src/google/protobuf/stubs/atomicops.h | 2 + .../stubs/atomicops_internals_ppc_gcc.h | 155 ++++++++++++++++++ src/google/protobuf/stubs/platform_macros.h | 3 + 3 files changed, 160 insertions(+) create mode 100644 src/google/protobuf/stubs/atomicops_internals_ppc_gcc.h diff --git a/src/google/protobuf/stubs/atomicops.h b/src/google/protobuf/stubs/atomicops.h index 5fa31b0ae..d5cead60b 100644 --- a/src/google/protobuf/stubs/atomicops.h +++ b/src/google/protobuf/stubs/atomicops.h @@ -212,6 +212,8 @@ Atomic64 Release_Load(volatile const Atomic64* ptr); #include #elif defined(__native_client__) #include +#elif defined(GOOGLE_PROTOBUF_ARCH_PPC) +#include #elif (((__GNUC__ == 4) && (__GNUC_MINOR__ >= 7)) || (__GNUC__ > 4)) #include #elif defined(__clang__) diff --git a/src/google/protobuf/stubs/atomicops_internals_ppc_gcc.h b/src/google/protobuf/stubs/atomicops_internals_ppc_gcc.h new file mode 100644 index 000000000..8231a578f --- /dev/null +++ b/src/google/protobuf/stubs/atomicops_internals_ppc_gcc.h @@ -0,0 +1,155 @@ +// Protocol Buffers - Google's data interchange format +// Copyright 2015 Google Inc. All rights reserved. +// https://developers.google.com/protocol-buffers/ +// +// 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. + +// Author: ogabbay@advaoptical.com (Oded Gabbay) +// Cleaned up by: bsilver16384@gmail.com (Brian Silverman) +// +// This file is an internal atomic implementation, use atomicops.h instead. + +#ifndef GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_PPC_GCC_H_ +#define GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_PPC_GCC_H_ + +#define ATOMICOPS_COMPILER_BARRIER() __asm__ __volatile__("" : : : "memory") + +namespace google { +namespace protobuf { +namespace internal { + +inline Atomic32 NoBarrier_CompareAndSwap(volatile Atomic32 *ptr, + Atomic32 old_value, + Atomic32 new_value) { + Atomic32 prev; + + __asm__ __volatile__( + "0: \n\t" + "lwarx %[prev],0,%[ptr] \n\t" + "cmpw 0,%[prev],%[old_value] \n\t" + "bne- 1f \n\t" + "stwcx. %[new_value],0,%[ptr] \n\t" + "bne- 0b \n\t" + "1: \n\t" + : [prev] "=&r"(prev), "+m"(*ptr) + : [ptr] "r"(ptr), [old_value] "r"(old_value), [new_value] "r"(new_value) + : "cc", "memory"); + + return prev; +} + +inline Atomic32 NoBarrier_AtomicExchange(volatile Atomic32 *ptr, + Atomic32 new_value) { + Atomic32 old; + + __asm__ __volatile__( + "0: \n\t" + "lwarx %[old],0,%[ptr] \n\t" + "stwcx. %[new_value],0,%[ptr] \n\t" + "bne- 0b \n\t" + : [old] "=&r"(old), "+m"(*ptr) + : [ptr] "r"(ptr), [new_value] "r"(new_value) + : "cc", "memory"); + + return old; +} + +inline Atomic32 NoBarrier_AtomicIncrement(volatile Atomic32 *ptr, + Atomic32 increment) { + Atomic32 temp; + + __asm__ __volatile__( + "0: \n\t" + "lwarx %[temp],0,%[ptr] \n\t" + "add %[temp],%[increment],%[temp] \n\t" + "stwcx. %[temp],0,%[ptr] \n\t" + "bne- 0b \n\t" + : [temp] "=&r"(temp) + : [increment] "r"(increment), [ptr] "r"(ptr) + : "cc", "memory"); + + return temp; +} + +inline Atomic32 Barrier_AtomicIncrement(volatile Atomic32 *ptr, + Atomic32 increment) { + MemoryBarrier(); + Atomic32 res = NoBarrier_AtomicIncrement(ptr, increment); + MemoryBarrier(); + return res; +} + +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(); + Atomic32 res = NoBarrier_CompareAndSwap(ptr, old_value, new_value); + return res; +} + +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 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; +} + +} // namespace internal +} // namespace protobuf +} // namespace google + +#undef ATOMICOPS_COMPILER_BARRIER + +#endif // GOOGLE_PROTOBUF_ATOMICOPS_INTERNALS_PPC_GCC_H_ diff --git a/src/google/protobuf/stubs/platform_macros.h b/src/google/protobuf/stubs/platform_macros.h index 9e0344d8f..9edf34b2f 100644 --- a/src/google/protobuf/stubs/platform_macros.h +++ b/src/google/protobuf/stubs/platform_macros.h @@ -73,6 +73,9 @@ #elif defined(_POWER) #define GOOGLE_PROTOBUF_ARCH_POWER 1 #define GOOGLE_PROTOBUF_ARCH_64_BIT 1 +#elif defined(__PPC__) +#define GOOGLE_PROTOBUF_ARCH_PPC 1 +#define GOOGLE_PROTOBUF_ARCH_32_BIT 1 #elif defined(__GNUC__) # if (((__GNUC__ == 4) && (__GNUC_MINOR__ >= 7)) || (__GNUC__ > 4)) // We fallback to the generic Clang/GCC >= 4.7 implementation in atomicops.h