_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
Parameter |
Description |
[in] a |
An integer. |
Return value
The number of bits set to one in a.
Requirements
Intrinsic |
Architecture |
_mm_popcnt_u64 |
x64 |
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