_InterlockedXor intrinsic functions

Article
08/03/2021

Microsoft Specific

Perform an atomic bitwise exclusive or (XOR) operation on a variable shared by multiple threads.

Syntax

long _InterlockedXor(
   long volatile * Value,
   long Mask
);
long _InterlockedXor_acq(
   long volatile * Value,
   long Mask
);
long _InterlockedXor_HLEAcquire(
   long volatile * Value,
   long Mask
);
long _InterlockedXor_HLERelease(
   long volatile * Value,
   long Mask
);
long _InterlockedXor_nf(
   long volatile * Value,
   long Mask
);
long _InterlockedXor_np(
   long volatile * Value,
   long Mask
);
long _InterlockedXor_rel(
   long volatile * Value,
   long Mask
);
char _InterlockedXor8(
   char volatile * Value,
   char Mask
);
char _InterlockedXor8_acq(
   char volatile * Value,
   char Mask
);
char _InterlockedXor8_nf(
   char volatile * Value,
   char Mask
);
char _InterlockedXor8_np(
   char volatile * Value,
   char Mask
);
char _InterlockedXor8_rel(
   char volatile * Value,
   char Mask
);
short _InterlockedXor16(
   short volatile * Value,
   short Mask
);
short _InterlockedXor16_acq(
   short volatile * Value,
   short Mask
);
short _InterlockedXor16_nf (
   short volatile * Value,
   short Mask
);
short _InterlockedXor16_np (
   short volatile * Value,
   short Mask
);
short _InterlockedXor16_rel(
   short volatile * Value,
   short Mask
);
__int64 _InterlockedXor64(
   __int64 volatile * Value,
   __int64 Mask
);
__int64 _InterlockedXor64_acq(
   __int64 volatile * Value,
   __int64 Mask
);
__int64 _InterlockedXor64_HLEAcquire(
   __int64 volatile * Value,
   __int64 Mask
);
__int64 _InterlockedXor64_HLERelease(
   __int64 volatile * Value,
   __int64 Mask
);
__int64 _InterlockedXor64_nf(
   __int64 volatile * Value,
   __int64 Mask
);
__int64 _InterlockedXor64_np(
   __int64 volatile * Value,
   __int64 Mask
);
__int64 _InterlockedXor64_rel(
   __int64 volatile * Value,
   __int64 Mask
);

Parameters

Value
[in, out] A pointer to the first operand, to be replaced by the result.

Mask
[in] The second operand.

Return value

The original value of the first operand.

Requirements

Intrinsic	Architecture	Header
`_InterlockedXor`, `_InterlockedXor8`, `_InterlockedXor16`	x86, ARM, x64, ARM64	<intrin.h>
`_InterlockedXor64`	ARM, x64, ARM64	<intrin.h>
`_InterlockedXor_acq`, `_InterlockedXor_nf`, `_InterlockedXor_rel`, `_InterlockedXor8_acq`, `_InterlockedXor8_nf`, `_InterlockedXor8_rel`, `_InterlockedXor16_acq`, `_InterlockedXor16_nf`, `_InterlockedXor16_rel`, `_InterlockedXor64_acq`, `_InterlockedXor64_nf`, `_InterlockedXor64_rel`,	ARM, ARM64	<intrin.h>
`_InterlockedXor_np`, `_InterlockedXor8_np`, `_InterlockedXor16_np`, `_InterlockedXor64_np`	x64	<intrin.h>
`_InterlockedXor_HLEAcquire`, `_InterlockedXor_HLERelease`	x86, x64	<immintrin.h>
`_InterlockedXor64_HLEAcquire`, `_InterlockedXor64_HLERelease`	x64	<immintrin.h>

Remarks

The number in the name of each function specifies the bit size of the arguments.

On ARM platforms, use the intrinsics with _acq and _rel suffixes if you need acquire and release semantics, such as at the beginning and end of a critical section. The ARM intrinsics with an _nf ("no fence") suffix don't act as a memory barrier.

The intrinsics with an _np ("no prefetch") suffix prevent a possible prefetch operation from being inserted by the compiler.

On Intel platforms that support Hardware Lock Elision (HLE) instructions, the intrinsics with _HLEAcquire and _HLERelease suffixes include a hint to the processor that can accelerate performance by eliminating a lock write step in hardware. If these intrinsics are called on platforms that don't support HLE, the hint is ignored.

Example

// _InterLockedXor.cpp
#include <stdio.h>
#include <intrin.h>

#pragma intrinsic(_InterlockedXor)

int main()
{
        long data1 = 0xFF00FF00;
        long data2 = 0x00FFFF00;
        long retval;
        retval = _InterlockedXor(&data1, data2);
        printf_s("0x%x 0x%x 0x%x", data1, data2, retval);
}

0xffff0000 0xffff00 0xff00ff00

END Microsoft Specific

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