1#include "libm.h"
2
3float nexttowardf(float x, long double y)
4{
5 union {float f; uint32_t i;} ux = {x};
6 uint32_t e;
7
8 if (isnan(x) || isnan(y))
9 return x + y;
10 if (x == y)
11 return y;
12 if (x == 0) {
13 ux.i = 1;
14 if (signbit(y))
15 ux.i |= 0x80000000;
16 } else if (x < y) {
17 if (signbit(x))
18 ux.i--;
19 else
20 ux.i++;
21 } else {
22 if (signbit(x))
23 ux.i++;
24 else
25 ux.i--;
26 }
27 e = ux.i & 0x7f800000;
28 /* raise overflow if ux.f is infinite and x is finite */
29 if (e == 0x7f800000)
30 FORCE_EVAL(x+x);
31 /* raise underflow if ux.f is subnormal or zero */
32 if (e == 0)
33 FORCE_EVAL(x*x + ux.f*ux.f);
34 return ux.f;
35}