1 /* s_ceill.c -- long double version of s_ceil.c.
2 */
3
4 /*
5 * ====================================================
6 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
7 *
8 * Developed at SunPro, a Sun Microsystems, Inc. business.
9 * Permission to use, copy, modify, and distribute this
10 * software is freely granted, provided that this notice
11 * is preserved.
12 * ====================================================
13 */
14
15 #if defined (LIBM_SCCS) && ! defined (lint)
16 static char rcsid[] = "$NetBSD: $";
17 #endif
18
19 /*
20 * ceill(x)
21 * Return x rounded toward -inf to integral value
22 * Method:
23 * Bit twiddling.
24 */
25
26 #define NO_MATH_REDIRECT
27 #include <math.h>
28 #include <math_private.h>
29 #include <libm-alias-ldouble.h>
30 #include <math-use-builtins.h>
31
32 _Float128
__ceill(_Float128 x)33 __ceill (_Float128 x)
34 {
35 #if USE_CEILL_BUILTIN
36 return __builtin_ceill (x);
37 #else
38 /* Use generic implementation. */
39 int64_t i0, i1, j0;
40 uint64_t i, j;
41 GET_LDOUBLE_WORDS64 (i0, i1, x);
42 j0 = ((i0 >> 48) & 0x7fff) - 0x3fff;
43 if (j0 < 48)
44 {
45 if (j0 < 0)
46 {
47 /* return 0 * sign (x) if |x| < 1 */
48 if (i0 < 0)
49 {
50 i0 = 0x8000000000000000ULL;
51 i1 = 0;
52 }
53 else if ((i0 | i1) != 0)
54 {
55 i0 = 0x3fff000000000000ULL;
56 i1 = 0;
57 }
58 }
59 else
60 {
61 i = (0x0000ffffffffffffULL) >> j0;
62 if (((i0 & i) | i1) == 0)
63 return x; /* x is integral */
64 if (i0 > 0)
65 i0 += (0x0001000000000000LL) >> j0;
66 i0 &= (~i);
67 i1 = 0;
68 }
69 }
70 else if (j0 > 111)
71 {
72 if (j0 == 0x4000)
73 return x + x; /* inf or NaN */
74 else
75 return x; /* x is integral */
76 }
77 else
78 {
79 i = -1ULL >> (j0 - 48);
80 if ((i1 & i) == 0)
81 return x; /* x is integral */
82 if (i0 > 0)
83 {
84 if (j0 == 48)
85 i0 += 1;
86 else
87 {
88 j = i1 + (1LL << (112 - j0));
89 if (j < i1)
90 i0 += 1; /* got a carry */
91 i1 = j;
92 }
93 }
94 i1 &= (~i);
95 }
96 SET_LDOUBLE_WORDS64 (x, i0, i1);
97 return x;
98 #endif /* ! USE_CEILL_BUILTIN */
99 }
100 libm_alias_ldouble (__ceil, ceil)
101