#include <stdio.h>
#include <stdlib.h>

/* the original */
int syracuse1(int num) {
  int count ;
  count = 0 ;
  while (num != 1) {
    if (num%2==0) {
      num = num/2 ;
    } else {
      num = 3*num + 1 ;
    }
    ++count ;
  }
  return count ;
}

/* by the rules */
int syracuse2(int num) {
  int count, _d1, _d2, _d3, _d4 ;
  count = 0 ;
 sloop:
  _d1 = num != 1 ;
  if (_d1 == 0) goto eloop ;
  _d2 = num & 1 ;
  _d3 = _d2 == 0 ;
  if (_d3 == 0) goto elslab ;
  num = num >> 1 ;
  goto jnlab ;
 elslab :
  _d4 = 3*num ;
  num = _d4 + 1 ;
 jnlab:
  ++count ;
  goto sloop ;
 eloop:
  return count ;
}

/* no multiplication! */
int syracuse3(int num) {
  int count, _d1, _d2, _d3, _d4, _d5 ;
  count = 0 ;
 sloop:
  _d1 = num != 1 ;
  if (_d1 == 0) goto eloop ;
  _d2 = num & 1 ;
  _d3 = _d2 == 0 ;
  if (_d3 == 0) goto elslab ;
  num = num >> 1 ;
  goto jnlab ;
 elslab :
  _d4 = num+num ;
  _d5 = _d4+num ;
  num = _d5 + 1 ;
 jnlab:
  ++count ;
  goto sloop ;
 eloop:
  return count ;
}


/* Taking advantage of Z bits and WREG */
int syracuse4(int num) {
  int count, WREG ;
  count = 0 ;
 sloop:
  if ((num - 1) == 0) goto eloop ;
  if ((num & 1) != 0) goto elslab ;
  num = num >> 1;
  goto jnlab ;
 elslab :
  WREG = num + num ;
  WREG = num + WREG ;
  num  =   1 + WREG ;
 jnlab:
  ++count ;
  goto sloop ;
 eloop:
  return count ;
}

/* the original -- with odd cases unrolled */
int syracuse5(int num) {
  int count ;
  count = 0 ;
  while (num != 1) {
    if ((num & 1) == 0) {
      num = num >> 1 ;
      ++count ;
    } else {
      num = (3*num + 1)/2 ;
      count += 2 ;
    }
  }
  return count ;
}

/* -- with shift replacing multiplication */
int syracuse6(int num) {
  int count ;
  count = 0 ;
  while (num != 1) {
    int halfnum = num >> 1 ;
    int oddnum  = num  & 1 ;
    if (oddnum == 0) {
      num = halfnum ;
      ++count ;
    } else {
      num = num + halfnum + 1 ;
      count += 2 ;
    }
  }
  return count ;
}

/* -- more PICish */
int syracuse7(int num) {
  int count, halfnum, oddnum ;
  count = 0 ;
 sloop:
  halfnum = num >> 1 ;
  oddnum  = num  & 1 ;
  if (halfnum == 0) goto eloop ;
  if (oddnum  != 0) goto elslab ;
  num = halfnum ;
  ++count ;
  goto jnlab ;
 elslab:
  num = num + halfnum + 1 ;
  count += 2 ;
 jnlab :
  goto sloop ;
 eloop:
  return count ;
}

/* -- even more PICish */
int syracuse8(int num) {
  int count, WREG, Cbit ;
  count = 0 ;
 sloop:
  WREG = num >> 1 ;              /* use lsr to        */
  Cbit = num  & 1 ;              /* set WREG and Cbit */
  if (WREG == 0) goto eloop ;
  if (Cbit != 0) goto elslab ;
  num = WREG ;
  ++count ;
  goto jnlab ;
 elslab:
  num = num + WREG + Cbit ;      /* use addc */
  count += 2 ;
 jnlab :
  goto sloop ;
 eloop:
  return count ;
}

/* Like my PIC solution */
int syracuse9(int num) {
  int count, WREG, Cbit ;
  count = 0 ;
  goto tstloop ;
 xodd:
  num = num + WREG + Cbit ;      /* use addc */
  count += 2 ;
  goto tstloop ;
 xeven:
  num = WREG ;
  ++count ;
 tstloop:
  WREG = num >> 1 ;              /* use lsr to        */
  Cbit = num  & 1 ;              /* set WREG and Cbit */
  if (Cbit == 0) goto xeven ;
  if (WREG != 0) goto xodd ;
  return count ;
}

int main(int argc, char **argv) {
  int n = 123456789 ;
  printf("%d\n", syracuse1(n)) ;
  printf("%d\n", syracuse2(n)) ;
  printf("%d\n", syracuse3(n)) ;
  printf("%d\n", syracuse4(n)) ;
  printf("%d\n", syracuse5(n)) ;
  printf("%d\n", syracuse6(n)) ;
  printf("%d\n", syracuse7(n)) ;
  printf("%d\n", syracuse8(n)) ;
  printf("%d\n", syracuse9(n)) ;
  return (EXIT_SUCCESS) ;
}