_mm_popcnt_u64

Microsoft Specific

Emits the Streaming SIMD Extensions 4 (SSE4) instruction popcnt. This instruction calculates the number of bits of the parameter that are set to 1.

int _mm_popcnt_u64 (
   unsigned __int64 a
); 

Parameters

Return value

The number of bits set to one in a.

Requirements

Header file <nmmintrin.h>

Remarks

Before you use this intrinsic, software must ensure that the processor supports the instruction.

Example

#include <stdio.h>
#include <nmmintrin.h>

int main ()
{
    unsigned __int64 a = 0x123456789ABCDEF0;

    int res = _mm_popcnt_u64(a);

    printf_s("Result res should be 32: %d\n", res);

    return 0;
}

Result res should be 32: 32

See Also

Reference

__m64