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 | #include <math-use-builtins.h> |
32 | |
33 | _Float128 |
34 | __nearbyintl (_Float128 x) |
35 | { |
36 | #if USE_NEARBYINTL_BUILTIN |
37 | return __builtin_nearbyintl (x); |
38 | #else |
39 | /* Use generic implementation. */ |
40 | static const _Float128 |
41 | TWO112[2] = { |
42 | L(5.19229685853482762853049632922009600E+33), /* 0x406F000000000000, 0 */ |
43 | L(-5.19229685853482762853049632922009600E+33) /* 0xC06F000000000000, 0 */ |
44 | }; |
45 | fenv_t env; |
46 | int64_t i0, j0, sx; |
47 | uint64_t i1 __attribute__ ((unused)); |
48 | _Float128 w, t; |
49 | GET_LDOUBLE_WORDS64 (i0, i1, x); |
50 | sx = (((uint64_t) i0) >> 63); |
51 | j0 = ((i0 >> 48) & 0x7fff) - 0x3fff; |
52 | if (j0 < 112) |
53 | { |
54 | if (j0 < 0) |
55 | { |
56 | feholdexcept (&env); |
57 | w = TWO112[sx] + math_opt_barrier (x); |
58 | t = w - TWO112[sx]; |
59 | math_force_eval (t); |
60 | fesetenv (&env); |
61 | GET_LDOUBLE_MSW64 (i0, t); |
62 | SET_LDOUBLE_MSW64 (t, (i0 & 0x7fffffffffffffffLL) | (sx << 63)); |
63 | return t; |
64 | } |
65 | } |
66 | else |
67 | { |
68 | if (j0 == 0x4000) |
69 | return x + x; /* inf or NaN */ |
70 | else |
71 | return x; /* x is integral */ |
72 | } |
73 | feholdexcept (&env); |
74 | w = TWO112[sx] + math_opt_barrier (x); |
75 | t = w - TWO112[sx]; |
76 | math_force_eval (t); |
77 | fesetenv (&env); |
78 | return t; |
79 | #endif /* ! USE_NEARBYINTL_BUILTIN */ |
80 | } |
81 | libm_alias_ldouble (__nearbyint, nearbyint) |
82 | |