1/* s_rintf.c -- float version of s_rint.c.
2 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3 */
4/* Adapted for use as nearbyint by Ulrich Drepper <drepper@cygnus.com>. */
5
6/*
7 * ====================================================
8 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
9 *
10 * Developed at SunPro, a Sun Microsystems, Inc. business.
11 * Permission to use, copy, modify, and distribute this
12 * software is freely granted, provided that this notice
13 * is preserved.
14 * ====================================================
15 */
16
17
18#include <fenv.h>
19#include <math.h>
20#include <math-barriers.h>
21#include <math_private.h>
22#include <fenv_private.h>
23#include <libm-alias-float.h>
24#include <math-use-builtins.h>
25
26float
27__nearbyintf (float x)
28{
29#if USE_NEARBYINTF_BUILTIN
30 return __builtin_nearbyintf (x);
31#else
32 /* Use generic implementation. */
33 static const float
34 TWO23[2] = {
35 8.3886080000e+06, /* 0x4b000000 */
36 -8.3886080000e+06, /* 0xcb000000 */
37 };
38 fenv_t env;
39 int32_t i0, j0, sx;
40 float w, t;
41 GET_FLOAT_WORD (i0, x);
42 sx = (i0 >> 31) & 1;
43 j0 = ((i0 >> 23) & 0xff) - 0x7f;
44 if (j0 < 23)
45 {
46 if (j0 < 0)
47 {
48 libc_feholdexceptf (&env);
49 w = TWO23[sx] + math_opt_barrier (x);
50 t = w - TWO23[sx];
51 math_force_eval (t);
52 libc_fesetenvf (&env);
53 GET_FLOAT_WORD (i0, t);
54 SET_FLOAT_WORD (t, (i0 & 0x7fffffff) | (sx << 31));
55 return t;
56 }
57 }
58 else
59 {
60 if (__glibc_unlikely (j0 == 0x80))
61 return x + x; /* inf or NaN */
62 else
63 return x; /* x is integral */
64 }
65 libc_feholdexceptf (&env);
66 w = TWO23[sx] + math_opt_barrier (x);
67 t = w - TWO23[sx];
68 math_force_eval (t);
69 libc_fesetenvf (&env);
70 return t;
71#endif /* ! USE_NEARBYINT_BUILTIN */
72}
73libm_alias_float (__nearbyint, nearbyint)
74