Line data    Source code

       1             : //===-- Atomic.cpp - Atomic Operations --------------------------*- C++ -*-===//
       2             : //
       3             : //                     The LLVM Compiler Infrastructure
       4             : //
       5             : // This file is distributed under the University of Illinois Open Source
       6             : // License. See LICENSE.TXT for details.
       7             : //
       8             : //===----------------------------------------------------------------------===//
       9             : //
      10             : //  This file implements atomic operations.
      11             : //
      12             : //===----------------------------------------------------------------------===//
      13             : 
      14             : #include "llvm/Support/Atomic.h"
      15             : #include "llvm/Config/llvm-config.h"
      16             : 
      17             : using namespace llvm;
      18             : 
      19             : #if defined(_MSC_VER)
      20             : #include <intrin.h>
      21             : 
      22             : // We must include windows.h after intrin.h.
      23             : #include <windows.h>
      24             : #undef MemoryFence
      25             : #endif
      26             : 
      27             : #if defined(__GNUC__) || (defined(__IBMCPP__) && __IBMCPP__ >= 1210)
      28             : #define GNU_ATOMICS
      29             : #endif
      30             : 
      31           0 : void sys::MemoryFence() {
      32             : #if LLVM_HAS_ATOMICS == 0
      33             :   return;
      34             : #else
      35             : #  if defined(GNU_ATOMICS)
      36           0 :   __sync_synchronize();
      37             : #  elif defined(_MSC_VER)
      38             :   MemoryBarrier();
      39             : #  else
      40             : # error No memory fence implementation for your platform!
      41             : #  endif
      42             : #endif
      43           0 : }
      44             : 
      45           0 : sys::cas_flag sys::CompareAndSwap(volatile sys::cas_flag* ptr,
      46             :                                   sys::cas_flag new_value,
      47             :                                   sys::cas_flag old_value) {
      48             : #if LLVM_HAS_ATOMICS == 0
      49             :   sys::cas_flag result = *ptr;
      50             :   if (result == old_value)
      51             :     *ptr = new_value;
      52             :   return result;
      53             : #elif defined(GNU_ATOMICS)
      54           0 :   return __sync_val_compare_and_swap(ptr, old_value, new_value);
      55             : #elif defined(_MSC_VER)
      56             :   return InterlockedCompareExchange(ptr, new_value, old_value);
      57             : #else
      58             : #  error No compare-and-swap implementation for your platform!
      59             : #endif
      60             : }