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glibc  2.9
Functions
s_nextafterl.c File Reference
#include "math.h"
#include <math_private.h>
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Functions

long double __nextafterl (long double x, long double y)

Function Documentation

long double __nextafterl ( long double  x,
long double  y 
)

Definition at line 33 of file s_nextafterl.c.

{
       int64_t hx,hy,ix,iy;
       u_int64_t lx,ly;

       GET_LDOUBLE_WORDS64(hx,lx,x);
       GET_LDOUBLE_WORDS64(hy,ly,y);
       ix = hx&0x7fffffffffffffffLL;             /* |x| */
       iy = hy&0x7fffffffffffffffLL;             /* |y| */

       if(((ix>=0x7fff000000000000LL)&&((ix-0x7fff000000000000LL)|lx)!=0) ||   /* x is nan */
          ((iy>=0x7fff000000000000LL)&&((iy-0x7fff000000000000LL)|ly)!=0))     /* y is nan */
          return x+y;
       if(x==y) return y;          /* x=y, return y */
       if((ix|lx)==0) {                   /* x == 0 */
           long double u;
           SET_LDOUBLE_WORDS64(x,hy&0x8000000000000000ULL,1);/* return +-minsubnormal */
           u = math_opt_barrier (x);
           u = u * u;
           math_force_eval (u);           /* raise underflow flag */
           return x;
       }
       if(hx>=0) {                 /* x > 0 */
           if(hx>hy||((hx==hy)&&(lx>ly))) {      /* x > y, x -= ulp */
              if(lx==0) hx--;
              lx--;
           } else {                       /* x < y, x += ulp */
              lx++;
              if(lx==0) hx++;
           }
       } else {                           /* x < 0 */
           if(hy>=0||hx>hy||((hx==hy)&&(lx>ly))){/* x < y, x -= ulp */
              if(lx==0) hx--;
              lx--;
           } else {                       /* x > y, x += ulp */
              lx++;
              if(lx==0) hx++;
           }
       }
       hy = hx&0x7fff000000000000LL;
       if(hy==0x7fff000000000000LL) return x+x;/* overflow  */
       if(hy==0) {
           long double u = x*x;           /* underflow */
           math_force_eval (u);           /* raise underflow flag */
       }
       SET_LDOUBLE_WORDS64(x,hx,lx);
       return x;
}