refactor compat_popcnt()

- refactor impleentation
- move function to class member method
This commit is contained in:
psychocrypt
2017-05-23 21:57:19 +02:00
parent b8061d8041
commit e8a8cca0fb
+11 -13
View File
@@ -3,19 +3,6 @@
#include "console.h"
#include <hwloc.h>
/*
* compat_popcnt is adapted from public domain code by:
* Portable Snippets - https://gitub.com/nemequ/portable-snippets
* Created by Evan Nemerson <evan@nemerson.com>
*/
int compat_popcnt(size_t x)
{
x = x - ((x >> 1) & (size_t)~(size_t)0/3);
x = (x & (size_t)~(size_t)0/15*3) + ((x >> 2) & (size_t)~(size_t)0/15*3);
x = (x + (x >> 4)) & (size_t)~(size_t)0/255*15;
return (size_t)(x * ((size_t)~(size_t)0/255)) >> (sizeof(size_t) - 1) * 8;
}
#ifdef _WIN32
#include <windows.h>
#else
@@ -73,6 +60,17 @@ public:
private:
/** count bits with ones */
template<typename T>
int compat_popcnt(T x)
{
int count = 0;
for( int i = 0; i < sizeof(T) - 1; ++i )
if( ( ( x >> i ) & 1 ) == 1 )
++count;
return count;
}
int rightZeros(size_t v)
{
int c;