MdePkg/Library/BaseSynchronizationLib/X64/InterlockedCompareExchange16.c

/** @file
  InterlockedCompareExchange16 function

  Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
  Copyright (c) 2015, Linaro Ltd. All rights reserved.<BR>
  SPDX-License-Identifier: BSD-2-Clause-Patent

**/

/**
  Microsoft Visual Studio 7.1 Function Prototypes for I/O Intrinsics.
**/

__int16
_InterlockedCompareExchange16 (
  __int16 volatile  *Destination,
  __int16           Exchange,
  __int16           Comperand
  );

#pragma intrinsic(_InterlockedCompareExchange16)

/**
  Performs an atomic compare exchange operation on a 16-bit unsigned integer.

  Performs an atomic compare exchange operation on the 16-bit unsigned integer specified
  by Value.  If Value is equal to CompareValue, then Value is set to ExchangeValue and
  CompareValue is returned.  If Value is not equal to CompareValue, then Value is returned.
  The compare exchange operation must be performed using MP safe mechanisms.

  @param  Value         A pointer to the 16-bit value for the compare exchange
                        operation.
  @param  CompareValue  16-bit value used in compare operation.
  @param  ExchangeValue 16-bit value used in exchange operation.

  @return The original *Value before exchange.

**/
UINT16
EFIAPI
InternalSyncCompareExchange16 (
  IN      volatile UINT16  *Value,
  IN      UINT16           CompareValue,
  IN      UINT16           ExchangeValue
  )
{
  return _InterlockedCompareExchange16 (Value, ExchangeValue, CompareValue);
}