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 | |
25 | static const float |
26 | TWO23[2]={ |
27 | 8.3886080000e+06, /* 0x4b000000 */ |
28 | -8.3886080000e+06, /* 0xcb000000 */ |
29 | }; |
30 | |
31 | float |
32 | __nearbyintf(float x) |
33 | { |
34 | fenv_t env; |
35 | int32_t i0,j0,sx; |
36 | float w,t; |
37 | GET_FLOAT_WORD(i0,x); |
38 | sx = (i0>>31)&1; |
39 | j0 = ((i0>>23)&0xff)-0x7f; |
40 | if(j0<23) { |
41 | if(j0<0) { |
42 | libc_feholdexceptf (&env); |
43 | w = TWO23[sx] + math_opt_barrier (x); |
44 | t = w-TWO23[sx]; |
45 | math_force_eval (t); |
46 | libc_fesetenvf (&env); |
47 | GET_FLOAT_WORD(i0,t); |
48 | SET_FLOAT_WORD(t,(i0&0x7fffffff)|(sx<<31)); |
49 | return t; |
50 | } |
51 | } else { |
52 | if(__builtin_expect(j0==0x80, 0)) return x+x; /* inf or NaN */ |
53 | else return x; /* x is integral */ |
54 | } |
55 | libc_feholdexceptf (&env); |
56 | w = TWO23[sx] + math_opt_barrier (x); |
57 | t = w-TWO23[sx]; |
58 | math_force_eval (t); |
59 | libc_fesetenvf (&env); |
60 | return t; |
61 | } |
62 | libm_alias_float (__nearbyint, nearbyint) |
63 | |