sysdeps/m68k/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 #ifdef __STDC__
  33         long double __nextafterl(long double x, long double y)
  34 #else
  35         long double __nextafterl(x,y)
  36         long double x,y;
  37 #endif
  38 {
  39         int32_t ix,iy,esx,esy;
  40         u_int32_t hx,hy,lx,ly;
  41
  42         GET_LDOUBLE_WORDS(esx,hx,lx,x);
  43         GET_LDOUBLE_WORDS(esy,hy,ly,y);
  44         ix = esx&0x7fff;                /* |x| */
  45         iy = esy&0x7fff;                /* |y| */
  46
  47         if(((ix==0x7fff)&&((hx&0x7fffffff)|lx)!=0) ||   /* x is nan */
  48            ((iy==0x7fff)&&((hy&0x7fffffff)|ly)!=0))     /* y is nan */
  49            return x+y;
  50         if(x==y) return y;              /* x=y, return y */
  51         if((ix|hx|lx)==0) {                     /* x == 0 */
  52             SET_LDOUBLE_WORDS(x,esy&0x8000,0,1);/* return +-minsubnormal */
  53             y = x*x;
  54             if(y==x) return y; else return x;   /* raise underflow flag */
  55         }
  56         if(esx>=0) {                    /* x > 0 */
  57             if(esx>esy||((esx==esy) && (hx>hy||((hx==hy)&&(lx>ly))))) {
  58               /* x > y, x -= ulp */
  59                 if(lx==0) {
  60                     if (ix != 0 && hx == 0x80000000) hx = 0;
  61                     if (hx==0) esx -= 1;
  62                     hx -= 1;
  63                 }
  64                 lx -= 1;
  65             } else {                            /* x < y, x += ulp */
  66                 lx += 1;
  67                 if(lx==0) {
  68                     hx += 1;
  69                     if (hx==0) {
  70                         hx = 0x80000000;
  71                         esx += 1;
  72                     }
  73                 }
  74             }
  75         } else {                                /* x < 0 */
  76             if(esy>=0||esx>esy||((esx==esy) && (hx>hy||((hx==hy)&&(lx>ly))))){
  77               /* x < y, x -= ulp */
  78                 if(lx==0) {
  79                     if (ix != 0 && hx == 0x80000000) hx = 0;
  80                     if (hx==0) esx -= 1;
  81                     hx -= 1;
  82                 }
  83                 lx -= 1;
  84             } else {                            /* x > y, x += ulp */
  85                 lx += 1;
  86                 if(lx==0) {
  87                     hx += 1;
  88                     if (hx==0) {
  89                         hx = 0x80000000;
  90                         esx += 1;
  91                     }
  92                 }
  93             }
  94         }
  95         esy = esx&0x7fff;
  96         if(esy==0x7fff) return x+x;     /* overflow  */
  97         if(esy==0 && (hx & 0x80000000) == 0) { /* underflow */
  98             y = x*x;
  99             if(y!=x) {          /* raise underflow flag */
 100                 SET_LDOUBLE_WORDS(y,esx,hx,lx);
 101                 return y;
 102             }
 103         }
 104         SET_LDOUBLE_WORDS(x,esx,hx,lx);
 105         return x;
 106 }
 107 weak_alias (__nextafterl, nextafterl)
 108 strong_alias (__nextafterl, __nexttowardl)
 109 weak_alias (__nextafterl, nexttowardl)