/* ex: set ts=2 et: */
#include <stdio.h>
#include <math.h>
#include <float.h>

/*
 * here is an example of how to select from a relatively small pool of choices
 * using a relatively large pool of possible, consecutive inputs. the output is
 * strictly customized for a single system but can easily be adjusted
 */

static unsigned CR = 0; /* our Cols/Rows index */
static struct { /* our Cols/Rows metrics for display */
  unsigned cols, 
           rows;
} ColsRows[] = {
  { 1, 2 }, /* default */
  { 1, 2 }, /* 1-2 */
  { 2, 2 }, /* 3-4 */
  { 2, 4 }, /* 5-8 */
  { 4, 4 }  /* 9-16 */
};

int main(void)
{
  unsigned i, n;
  for (i = 0; i <= 16; i++) {
    n = i - 1; /* find next-highest power of 2 for i */
    n |= n >> 1; /* fill in low bits below...*/
    n |= n >> 2;
    n++;
    CR = (unsigned)((log(n) / log(2)) + DBL_EPSILON); /* take log2 of n, round and integer-ize */
    printf("#%2u: n=%2u, CR=%u, rows=%u, cols=%u...\n", /* use l as index into Rows and Cols  */
      i, n, CR, ColsRows[CR].cols, ColsRows[CR].rows);
  }
  return 0;
}

#if 0

pizza@yeti:/vh/pe/www/~pizza/c
$ gcc -lm -o refactor_1-16_switch refactor_1-16_switch.c
pizza@yeti:/vh/pe/www/~pizza/c
$ ./refactor_1-16_switch | less
# 0: n= 0, CR=0, rows=1, cols=2...
# 1: n= 1, CR=0, rows=1, cols=2...
# 2: n= 2, CR=1, rows=1, cols=2...
# 3: n= 4, CR=2, rows=2, cols=2...
# 4: n= 4, CR=2, rows=2, cols=2...
# 5: n= 8, CR=3, rows=2, cols=4...
# 6: n= 8, CR=3, rows=2, cols=4...
# 7: n= 8, CR=3, rows=2, cols=4...
# 8: n= 8, CR=3, rows=2, cols=4...
# 9: n=16, CR=4, rows=4, cols=4...
#10: n=16, CR=4, rows=4, cols=4...
#11: n=16, CR=4, rows=4, cols=4...
#12: n=16, CR=4, rows=4, cols=4...
#13: n=16, CR=4, rows=4, cols=4...
#14: n=16, CR=4, rows=4, cols=4...
#15: n=16, CR=4, rows=4, cols=4...
#16: n=16, CR=4, rows=4, cols=4...
pizza@yeti:/vh/pe/www/~pizza/c
$

#endif