_InterlockedOr intrinsic functions

Article
10/29/2021

Microsoft Specific

Perform an atomic bitwise or operation on a variable shared by multiple threads.

Syntax

long _InterlockedOr(
   long volatile * Value,
   long Mask
);
long _InterlockedOr_acq(
   long volatile * Value,
   long Mask
);
long _InterlockedOr_HLEAcquire(
   long volatile * Value,
   long Mask
);
long _InterlockedOr_HLERelease(
   long volatile * Value,
   long Mask
);
long _InterlockedOr_nf(
   long volatile * Value,
   long Mask
);
long _InterlockedOr_np(
   long volatile * Value,
   long Mask
);
long _InterlockedOr_rel(
   long volatile * Value,
   long Mask
);
char _InterlockedOr8(
   char volatile * Value,
   char Mask
);
char _InterlockedOr8_acq(
   char volatile * Value,
   char Mask
);
char _InterlockedOr8_nf(
   char volatile * Value,
   char Mask
);
char _InterlockedOr8_np(
   char volatile * Value,
   char Mask
);
char _InterlockedOr8_rel(
   char volatile * Value,
   char Mask
);
short _InterlockedOr16(
   short volatile * Value,
   short Mask
);
short _InterlockedOr16_acq(
   short volatile * Value,
   short Mask
);
short _InterlockedOr16_nf(
   short volatile * Value,
   short Mask
);
short _InterlockedOr16_np(
   short volatile * Value,
   short Mask
);
short _InterlockedOr16_rel(
   short volatile * Value,
   short Mask
);
__int64 _InterlockedOr64(
   __int64 volatile * Value,
   __int64 Mask
);
__int64 _InterlockedOr64_acq(
   __int64 volatile * Value,
   __int64 Mask
);
__int64 _InterlockedOr64_HLEAcquire(
   __int64 volatile * Value,
   __int64 Mask
);
__int64 _InterlockedOr64_HLERelease(
   __int64 volatile * Value,
   __int64 Mask
);
__int64 _InterlockedOr64_nf(
   __int64 volatile * Value,
   __int64 Mask
);
__int64 _InterlockedOr64_np(
   __int64 volatile * Value,
   __int64 Mask
);
__int64 _InterlockedOr64_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 pointed to by the first parameter.

Requirements

Intrinsic	Architecture	Header
`_InterlockedOr`, `_InterlockedOr8`, `_InterlockedOr16`	x86, ARM, x64, ARM64	<intrin.h>
`_InterlockedOr64`	ARM, x64, ARM64	<intrin.h>
`_InterlockedOr_acq`, `_InterlockedOr_nf`, `_InterlockedOr_rel`, `_InterlockedOr8_acq`, `_InterlockedOr8_nf`, `_InterlockedOr8_rel`, `_InterlockedOr16_acq`, `_InterlockedOr16_nf`, `_InterlockedOr16_rel`, `_InterlockedOr64_acq`, `_InterlockedOr64_nf`, `_InterlockedOr64_rel`	ARM, ARM64	<intrin.h>
`_InterlockedOr_np`, `_InterlockedOr8_np`, `_InterlockedOr16_np`, `_InterlockedOr64_np`	x64	<intrin.h>
`_InterlockedOr_HLEAcquire`, `_InterlockedOr_HLERelease`	x86, x64	<immintrin.h>
`_InterlockedOr64_HLEAcquire`, `_InterlockedOr64_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

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

#pragma intrinsic(_InterlockedOr)

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

0xffffff00 0xffff00 0xff00ff00

END Microsoft Specific