Test for limits qNaN and sNaN. Fix some consts.

In general, problem not resolved, due to impossible
to return sNaN via float point register on Intel-like
processor.

 #include <float.h>
 #include <stdio.h>

 #include <ieee754.h>

long double ldb()
{ return LDBL_MIN; }

/*
 * Fpr 96-bit float (extended precision) on Intel
 * this test print something like
 * 00000000000000800100d1bf
 * (two low bytes uninitialized).
 * To see this, return from function required.
 * Direct assignment give good
 * 000000000000008001000000
 */

double fdbl()
{
  union ieee754_double v1;

  v1.ieee.negative = 0;
  v1.ieee.exponent = 0x7ff;
  v1.ieee.mantissa0 = 0x40000; /* sNaN here */
  v1.ieee.mantissa1 = 0x0;

  return v1.d;
}

/*
 * I found that I can't return sNaN from function on Intel (gcc)
 * If I form sNaN, and return appropriate value
 * I will take qNaN:
 * 000000000000fc7f
 * instead of
 * 000000000000f47f
 */

int main()
{
  int i;
  long double m = /* LDBL_MIN */ ldb();
  long double m1 = LDBL_MIN;
  double d = fdbl();
  union ieee754_double v1;

  v1.ieee.negative = 0;
  v1.ieee.exponent = 0x7ff;
  v1.ieee.mantissa0 = 0x40000;
  v1.ieee.mantissa1 = 0x0;

  for ( i = 0; i < sizeof(long double); ++i ) {
    printf( "%.2x", (unsigned)(*((unsigned char*)&m + i)) );
  }
  printf( "\n" );

  for ( i = 0; i < sizeof(long double); ++i ) {
    printf( "%.2x", (unsigned)(*((unsigned char*)&m1 + i)) );
  }
  printf( "\n" );

  for ( i = 0; i < sizeof(double); ++i ) {
    printf( "%.2x", (unsigned)(*((unsigned char*)&d + i)) );
  }
  printf( "\n" );

  for ( i = 0; i < sizeof(double); ++i ) {
    printf( "%.2x", (unsigned)(*((unsigned char*)&v1.d + i)) );
  }
  printf( "\n" );

  return 0;
}