source: scripts/fetch/eglibc/2.10.1/25-ldbl-nexttowardf.patch@ a991116

this change was made to generic __nexttowardf, but not the long double version

2008-05-05  Aurelien Jarno  <aurelien@aurel32.net>

        * sysdeps/ieee754/ldbl-128/s_nexttowardf.c: Include float.h.
        (__nexttowardf): Use math_opt_barrier and
        math_force_eval macros.  If FLT_EVAL_METHOD is not 0, force
        x to float using asm.

---
 sysdeps/ieee754/ldbl-128/s_nexttowardf.c |   26 ++++++++++++++++----------
 1 file changed, 16 insertions(+), 10 deletions(-)

--- a/sysdeps/ieee754/ldbl-128/s_nexttowardf.c
+++ b/sysdeps/ieee754/ldbl-128/s_nexttowardf.c
@@ -19,7 +19,8 @@
 #endif
 
 #include "math.h"
-#include "math_private.h"
+#include <math_private.h>
+#include <float.h>
 
 #ifdef __STDC__
        float __nexttowardf(float x, long double y)
@@ -44,10 +45,12 @@
           return x+y;
        if((long double) x==y) return y;        /* x=y, return y */
        if(ix==0) {                             /* x == 0 */
-           float x2;
+           float u;
            SET_FLOAT_WORD(x,(u_int32_t)((hy>>32)&0x80000000)|1);/* return +-minsub*/
-           x2 = x*x;
-           if(x2==x) return x2; else return x; /* raise underflow flag */
+           u = math_opt_barrier (x);
+           u = u * u;
+           math_force_eval (u);                /* raise underflow flag */
+           return x;
        }
        if(hx>=0) {                             /* x > 0 */
            if(hy<0||(ix>>23)>(iy>>48)-0x3f80
@@ -67,13 +70,16 @@
            }
        }
        hy = hx&0x7f800000;
-       if(hy>=0x7f800000) return x+x;  /* overflow  */
+       if(hy>=0x7f800000) {
+         x = x+x;      /* overflow  */
+         if (FLT_EVAL_METHOD != 0)
+           /* Force conversion to float.  */
+           asm ("" : "+m"(x));
+         return x;
+       }
        if(hy<0x00800000) {             /* underflow */
-           float x2 = x*x;
-           if(x2!=x) {         /* raise underflow flag */
-               SET_FLOAT_WORD(x2,hx);
-               return x2;
-           }
+           float u = x*x;
+           math_force_eval (u);        /* raise underflow flag */
        }
        SET_FLOAT_WORD(x,hx);
        return x;