ports/sysdeps/m68k/m680x0/fpu/s_nextafterl.c

   1 /* s_nextafterl.c -- long double version of s_nextafter.c.
   2  * Conversion to long double by Ulrich Drepper,
   3  * Cygnus Support, drepper@cygnus.com.
   4  * Fixed for m68k by Andreas Schwab <schwab@suse.de>.
   5  */
   6
   7 /*
   8  * ====================================================
   9  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
  10  *
  11  * Developed at SunPro, a Sun Microsystems, Inc. business.
  12  * Permission to use, copy, modify, and distribute this
  13  * software is freely granted, provided that this notice
  14  * is preserved.
  15  * ====================================================
  16  */
  17
  18 #if defined(LIBM_SCCS) && !defined(lint)
  19 static char rcsid[] = "$NetBSD: $";
  20 #endif
  21
  22 /* IEEE functions
  23  *      nextafterl(x,y)
  24  *      return the next machine floating-point number of x in the
  25  *      direction toward y.
  26  *   Special cases:
  27  */
  28
  29 #include <math.h>
  30 #include <math_private.h>
  31
  32 long double __nextafterl(long double x, long double y)
  33 {
  34         int32_t ix,iy,esx,esy;
  35         u_int32_t hx,hy,lx,ly;
  36
  37         GET_LDOUBLE_WORDS(esx,hx,lx,x);
  38         GET_LDOUBLE_WORDS(esy,hy,ly,y);
  39         ix = esx&0x7fff;                /* |x| */
  40         iy = esy&0x7fff;                /* |y| */
  41
  42         if(((ix==0x7fff)&&((hx&0x7fffffff)|lx)!=0) ||   /* x is nan */
  43            ((iy==0x7fff)&&((hy&0x7fffffff)|ly)!=0))     /* y is nan */
  44            return x+y;
  45         if(x==y) return y;              /* x=y, return y */
  46         if((ix|hx|lx)==0) {                     /* x == 0 */
  47             SET_LDOUBLE_WORDS(x,esy&0x8000,0,1);/* return +-minsubnormal */
  48             y = x*x;
  49             math_force_eval (y);                /* raise underflow flag */
  50             return x;
  51         }
  52         if(esx>=0) {                    /* x > 0 */
  53             if(esx>esy||((esx==esy) && (hx>hy||((hx==hy)&&(lx>ly))))) {
  54               /* x > y, x -= ulp */
  55                 if(lx==0) {
  56                     if (ix != 0 && hx == 0x80000000) hx = 0;
  57                     if (hx==0) esx -= 1;
  58                     hx -= 1;
  59                 }
  60                 lx -= 1;
  61             } else {                            /* x < y, x += ulp */
  62                 lx += 1;
  63                 if(lx==0) {
  64                     hx += 1;
  65                     if (hx==0) {
  66                         hx = 0x80000000;
  67                         esx += 1;
  68                     }
  69                 }
  70             }
  71         } else {                                /* x < 0 */
  72             if(esy>=0||esx>esy||((esx==esy) && (hx>hy||((hx==hy)&&(lx>ly))))){
  73               /* x < y, x -= ulp */
  74                 if(lx==0) {
  75                     if (ix != 0 && hx == 0x80000000) hx = 0;
  76                     if (hx==0) esx -= 1;
  77                     hx -= 1;
  78                 }
  79                 lx -= 1;
  80             } else {                            /* x > y, x += ulp */
  81                 lx += 1;
  82                 if(lx==0) {
  83                     hx += 1;
  84                     if (hx==0) {
  85                         hx = 0x80000000;
  86                         esx += 1;
  87                     }
  88                 }
  89             }
  90         }
  91         esy = esx&0x7fff;
  92         if(esy==0x7fff) return x+x;     /* overflow  */
  93         if(esy==0 && (hx & 0x80000000) == 0) { /* underflow */
  94             y = x*x;
  95             math_force_eval (y);                /* raise underflow flag */
  96         }
  97         SET_LDOUBLE_WORDS(x,esx,hx,lx);
  98         return x;
  99 }
 100 weak_alias (__nextafterl, nextafterl)
 101 strong_alias (__nextafterl, __nexttowardl)
 102 weak_alias (__nextafterl, nexttowardl)