#include "defs"
s26(pd0)                  /*  2.6  Hardware Characteristics     */
struct defs *pd0;
{
   static char qs26[8] = "s26    ";
   char *ps, *pt;
   char c0, c1;
   struct {float stemp, sone, sdeltaf;} S1; /* force it to store */
#define	one	S1.sone
#define	temp	S1.stemp
#define	deltaf	S1.sdeltaf
   struct {double stempd, soned, sdeltad;} S2; /* force it to store */
#define	oned	S2.soned
#define	tempd	S2.stempd
#define	deltad	S2.sdeltad
   static char s[] = "%3d bits in %ss.\n";
   static char s2[] = "%e is the least number that can be added to 1. (%s).\n";

   ps = qs26;
   pt = pd0->rfs;

   while(*pt++ = *ps++);

          /* Here, we shake the machinery a little to see what falls
             out.  First, we find out how many bits are in a char.  */

   pd0->cbits = 0;
   c0 = 0;
   c1 = 1;

   while(c0 != c1) {
     c1 = c1<<1;
     pd0->cbits = pd0->cbits+1;
   }
          /* That information lets us determine the size of everything else. */

   pd0->ibits = pd0->cbits * sizeof(int);
   pd0->sbits = pd0->cbits * sizeof(short);
   pd0->lbits = pd0->cbits * sizeof(long);
   pd0->ubits = pd0->cbits * sizeof(unsigned);
   pd0->fbits = pd0->cbits * sizeof(float);
   pd0->dbits = pd0->cbits * sizeof(double);

          /* We have now almost reconstructed the table in section 2.6, the
             exception being the range of the floating point hardware.
             Now there are just so many ways to conjure up a floating point
             representation system that it's damned near impossible to guess
             what's going on by writing a program to interpret bit patterns.
             Further, the information isn't all that useful, if we consider
             the fact that machines that won't handle numbers between 10**30
             and 10**-30 are very hard to find, and that people playing with
             numbers outside that range have a lot more to worry about than
             just the capacity of the characteristic.

             A much more useful measure is the precision, which can be ex-
             pressed in terms of the smallest number that can be added to
             1. without loss of significance. We calculate that here, for
             float and double.                       */

   one = 1.;
   deltaf = 1.;
   temp = 0.;
   while(temp != one) {
     temp = one+deltaf;
     deltaf = deltaf/2.;
   }
   pd0->fprec = deltaf * 4.;
   oned = 1.;
   deltad = 1.;
   tempd = 0.;
   while(tempd != oned) {
     tempd = oned+deltad;
     deltad = deltad/2.;
   }
print("delta=%g\n", deltad);
   pd0->dprec = deltad * 4.;

          /* Now, if anyone's interested, we publish the results.       */

   if(pd0->flgm != 0) {
     printf(s,pd0->cbits,"char");
     printf(s,pd0->ibits,"int");
     printf(s,pd0->sbits,"short");
     printf(s,pd0->lbits,"long");
     printf(s,pd0->ubits,"unsigned");
     printf(s,pd0->fbits,"float");
     printf(s,pd0->dbits,"double");
     printf(s2,pd0->fprec,"float");
     printf(s2,pd0->dprec,"double");
   }
          /* Since we are only exploring and perhaps reporting, but not 
             testing any features, we cannot return an error code.  */
   return 0;
}