20  */
  21 /*
  22  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
  23  */
  24 /*
  25  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
  26  * Use is subject to license terms.
  27  */
  28 
  29 #pragma weak nextafter = __nextafter
  30 #pragma weak _nextafter = __nextafter
  31 
  32 #include "libm.h"
  33 #include <float.h>                /* DBL_MIN */
  34 
  35 double
  36 nextafter(double x, double y) {
  37         int             hx, hy, k;
  38         double          ans;
  39         unsigned        lx;

  40 
  41         hx = ((int *)&x)[HIWORD];
  42         lx = ((int *)&x)[LOWORD];
  43         hy = ((int *)&y)[HIWORD];
  44         k = (hx & ~0x80000000) | lx;
  45 
  46         if (x == y)
  47                 return (y);             /* C99 requirement */
  48         if (x != x || y != y)
  49                 return (x * y);
  50         if (k == 0) {                   /* x = 0 */
  51                 k = hy & 0x80000000;
  52                 ((int *)&ans)[HIWORD] = k;
  53                 ((int *)&ans)[LOWORD] = 1;
  54         } else if (hx >= 0) {
  55                 if (x > y) {
  56                         ((int *)&ans)[LOWORD] = lx - 1;
  57                         k = (lx == 0)? hx - 1 : hx;
  58                         ((int *)&ans)[HIWORD] = k;
  59                 } else {

  62                         ((int *)&ans)[HIWORD] = k;
  63                 }
  64         } else {
  65                 if (x < y) {
  66                         ((int *)&ans)[LOWORD] = lx - 1;
  67                         k = (lx == 0)? hx - 1 : hx;
  68                         ((int *)&ans)[HIWORD] = k;
  69                 } else {
  70                         ((int *)&ans)[LOWORD] = lx + 1;
  71                         k  = (lx == 0xffffffff)? hx + 1 : hx;
  72                         ((int *)&ans)[HIWORD] = k;
  73                 }
  74         }
  75         k = (k >> 20) & 0x7ff;
  76         if (k == 0x7ff) {
  77                 /* overflow */
  78                 return (_SVID_libm_err(x, y, 46));
  79 #if !defined(__lint)
  80         } else if (k == 0) {
  81                 /* underflow */
  82                 volatile double dummy = DBL_MIN * copysign(DBL_MIN, x);
  83 #endif
  84         }
  85         return (ans);
  86 }

  20  */
  21 /*
  22  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
  23  */
  24 /*
  25  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
  26  * Use is subject to license terms.
  27  */
  28 
  29 #pragma weak nextafter = __nextafter
  30 #pragma weak _nextafter = __nextafter
  31 
  32 #include "libm.h"
  33 #include <float.h>                /* DBL_MIN */
  34 
  35 double
  36 nextafter(double x, double y) {
  37         int             hx, hy, k;
  38         double          ans;
  39         unsigned        lx;
  40         volatile double dummy;
  41 
  42         hx = ((int *)&x)[HIWORD];
  43         lx = ((int *)&x)[LOWORD];
  44         hy = ((int *)&y)[HIWORD];
  45         k = (hx & ~0x80000000) | lx;
  46 
  47         if (x == y)
  48                 return (y);             /* C99 requirement */
  49         if (x != x || y != y)
  50                 return (x * y);
  51         if (k == 0) {                   /* x = 0 */
  52                 k = hy & 0x80000000;
  53                 ((int *)&ans)[HIWORD] = k;
  54                 ((int *)&ans)[LOWORD] = 1;
  55         } else if (hx >= 0) {
  56                 if (x > y) {
  57                         ((int *)&ans)[LOWORD] = lx - 1;
  58                         k = (lx == 0)? hx - 1 : hx;
  59                         ((int *)&ans)[HIWORD] = k;
  60                 } else {

  63                         ((int *)&ans)[HIWORD] = k;
  64                 }
  65         } else {
  66                 if (x < y) {
  67                         ((int *)&ans)[LOWORD] = lx - 1;
  68                         k = (lx == 0)? hx - 1 : hx;
  69                         ((int *)&ans)[HIWORD] = k;
  70                 } else {
  71                         ((int *)&ans)[LOWORD] = lx + 1;
  72                         k  = (lx == 0xffffffff)? hx + 1 : hx;
  73                         ((int *)&ans)[HIWORD] = k;
  74                 }
  75         }
  76         k = (k >> 20) & 0x7ff;
  77         if (k == 0x7ff) {
  78                 /* overflow */
  79                 return (_SVID_libm_err(x, y, 46));
  80 #if !defined(__lint)
  81         } else if (k == 0) {
  82                 /* underflow */
  83                 dummy = DBL_MIN * copysign(DBL_MIN, x);
  84 #endif
  85         }
  86         return (ans);
  87 }