test bench

#include <stdio.h>
#include <x86intrin.h>
#include <cpuid.h>
#include <inttypes.h>

#define LAST "\033[0m"
#define RED "\033[22;31m"

void mul()
{
 int x=50,y=0;
 while(x)
 {
  y=x*2;
  x--;
 }
}


void leftshift()
{
 int x=50,y=0;
 while(x)
 {
  y=x<<1;
  x--;
 }
}

unsigned div7(unsigned n)
{
 return n/7;
}

unsigned bit_div7(unsigned num)
{
 unsigned x,y;

 x=(num>>1)+(num>>4);
 x+=x>>6;
 x+=(x>>12)+(x>>24);
 x>>=2;
 y=num-((x<<3)-x);

 return x+((y+1)>>3);
}


unsigned div3(unsigned n)
{
 return n/3;
}

//
unsigned bit_div3(unsigned num)
{
 unsigned x,y;

 x=(num>>2)+(num>>4);
 x+=x>>4;
 x+=x>>8;
 x+=x>>16;
 y=num-((x<<2)-x);
// ficou ruim , return x+( ((y<<3)+(y<<2)-y)>>5);
// ruim  return x+( (y+5+(y<<2)) >>4);
 return x+( (((y+1)<<2)+(y+1)) >>4);

}



int main(void)
{
  int i, x;
  uint32_t a, b, c, d;
  uint64_t y;

  x = 0;
  do {
    __cpuid(0, a, b, c, d);
    y = _rdtsc();
    leftshift();
    y = _rdtsc() - y;
  } while (++x < 2);

  printf("::: left shift: %s  %lld %s cicles\n",RED, y,LAST);


  x = 0;
  do {
    __cpuid(0, a, b, c, d);
    y = _rdtsc();
    mul();
    y = _rdtsc() - y;
  } while (++x < 2);

  printf("::: mul: %s %lld %s cicles\n", RED,y,LAST);


  unsigned int z=0;

  x = 0;
  do {
    __cpuid(0, a, b, c, d);
    y = _rdtsc();
    z=div7(560000*x);
    printf("result: %d\n",z);
    y = _rdtsc() - y;
  } while (++x < 2);

  printf("::: div7: %s %lld %s cicles\n", RED,y,LAST);

  z=0;
  x = 0;

  do {
    __cpuid(0, a, b, c, d);
    y = _rdtsc();
    z=bit_div7(560000*x);
    printf("result: %d\n",z);
    y = _rdtsc() - y;
  } while (++x < 2);

  printf("::: bit_div7:  %s %lld %s cicles\n",RED, y,LAST);


  x = 0;
  do {
    __cpuid(0, a, b, c, d);
    y = _rdtsc();
    z=div3(560000*x);
    printf("result: %d\n",z);
    y = _rdtsc() - y;
  } while (++x < 2);

  printf("::: div3:  %s %lld %s cicles\n",RED, y,LAST);

  z=0;
  x = 0;

  do {
    __cpuid(0, a, b, c, d);
    y = _rdtsc();
    z=bit_div3(560000*x);
    printf("result: %d\n",z);
    y = _rdtsc() - y;
  } while (++x < 2);

  printf("::: bit_div3:  %s %lld %s cicles\n", RED,y,LAST);



  return 0;
}