#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include "entcode.h"

int ec_ilog(ec_uint32 _v){

#if defined(EC_CLZ)

  return EC_CLZ0-EC_CLZ(_v);

#else

  /*On a Pentium M, this branchless version tested as the fastest on

     1,000,000,000 random 32-bit integers, edging out a similar version with

     branches, and a 256-entry LUT version.*/

  int ret;

  int m;

  ret=!!_v;

  m=!!(_v&0xFFFF0000)<<4;

  _v>>=m;

  ret|=m;

  m=!!(_v&0xFF00)<<3;

  _v>>=m;

  ret|=m;

  m=!!(_v&0xF0)<<2;

  _v>>=m;

  ret|=m;

  m=!!(_v&0xC)<<1;

  _v>>=m;

  ret|=m;

  ret+=!!(_v&0x2);

  return ret;

#endif

}