1 | /* s_nearbyintl.c -- long double version of s_nearbyint.c. |
2 | * Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz. |
3 | */ |
4 | |
5 | /* |
6 | * ==================================================== |
7 | * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. |
8 | * |
9 | * Developed at SunPro, a Sun Microsystems, Inc. business. |
10 | * Permission to use, copy, modify, and distribute this |
11 | * software is freely granted, provided that this notice |
12 | * is preserved. |
13 | * ==================================================== |
14 | */ |
15 | |
16 | /* |
17 | * nearbyintl(x) |
18 | * Return x rounded to integral value according to the prevailing |
19 | * rounding mode. |
20 | * Method: |
21 | * Using floating addition. |
22 | * Exception: |
23 | * Inexact flag raised if x not equal to rintl(x). |
24 | */ |
25 | |
26 | #include <fenv.h> |
27 | #include <math.h> |
28 | #include <math-barriers.h> |
29 | #include <math_private.h> |
30 | #include <libm-alias-ldouble.h> |
31 | |
32 | static const _Float128 |
33 | TWO112[2]={ |
34 | L(5.19229685853482762853049632922009600E+33), /* 0x406F000000000000, 0 */ |
35 | L(-5.19229685853482762853049632922009600E+33) /* 0xC06F000000000000, 0 */ |
36 | }; |
37 | |
38 | _Float128 __nearbyintl(_Float128 x) |
39 | { |
40 | fenv_t env; |
41 | int64_t i0,j0,sx; |
42 | uint64_t i1 __attribute__ ((unused)); |
43 | _Float128 w,t; |
44 | GET_LDOUBLE_WORDS64(i0,i1,x); |
45 | sx = (((uint64_t)i0)>>63); |
46 | j0 = ((i0>>48)&0x7fff)-0x3fff; |
47 | if(j0<112) { |
48 | if(j0<0) { |
49 | feholdexcept (&env); |
50 | w = TWO112[sx] + math_opt_barrier (x); |
51 | t = w-TWO112[sx]; |
52 | math_force_eval (t); |
53 | fesetenv (&env); |
54 | GET_LDOUBLE_MSW64(i0,t); |
55 | SET_LDOUBLE_MSW64(t,(i0&0x7fffffffffffffffLL)|(sx<<63)); |
56 | return t; |
57 | } |
58 | } else { |
59 | if(j0==0x4000) return x+x; /* inf or NaN */ |
60 | else return x; /* x is integral */ |
61 | } |
62 | feholdexcept (&env); |
63 | w = TWO112[sx] + math_opt_barrier (x); |
64 | t = w-TWO112[sx]; |
65 | math_force_eval (t); |
66 | fesetenv (&env); |
67 | return t; |
68 | } |
69 | libm_alias_ldouble (__nearbyint, nearbyint) |
70 | |