floorl.c raw

   1  #include "libm.h"
   2  
   3  #if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
   4  long double floorl(long double x)
   5  {
   6  	return floor(x);
   7  }
   8  #elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384
   9  
  10  static const long double toint = 1/LDBL_EPSILON;
  11  
  12  long double floorl(long double x)
  13  {
  14  	union ldshape u = {x};
  15  	int e = u.i.se & 0x7fff;
  16  	long double y;
  17  
  18  	if (e >= 0x3fff+LDBL_MANT_DIG-1 || x == 0)
  19  		return x;
  20  	/* y = int(x) - x, where int(x) is an integer neighbor of x */
  21  	if (u.i.se >> 15)
  22  		y = x - toint + toint - x;
  23  	else
  24  		y = x + toint - toint - x;
  25  	/* special case because of non-nearest rounding modes */
  26  	if (e <= 0x3fff-1) {
  27  		FORCE_EVAL(y);
  28  		return u.i.se >> 15 ? -1 : 0;
  29  	}
  30  	if (y > 0)
  31  		return x + y - 1;
  32  	return x + y;
  33  }
  34  #endif
  35