1 /* s_floorl.c -- long double version of s_floor.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 * floorl(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
__floorl(_Float128 x)33 __floorl (_Float128 x)
34 {
35 #if USE_FLOORL_BUILTIN
36 return __builtin_floorl (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 = i1 = 0;
51 }
52 else if (((i0 & 0x7fffffffffffffffLL) | i1) != 0)
53 {
54 i0 = 0xbfff000000000000ULL;
55 i1 = 0;
56 }
57 }
58 else
59 {
60 i = (0x0000ffffffffffffULL) >> j0;
61 if (((i0 & i) | i1) == 0)
62 return x; /* x is integral */
63 if (i0 < 0)
64 i0 += (0x0001000000000000LL) >> j0;
65 i0 &= (~i);
66 i1 = 0;
67 }
68 }
69 else if (j0 > 111)
70 {
71 if (j0 == 0x4000)
72 return x + x; /* inf or NaN */
73 else
74 return x; /* x is integral */
75 }
76 else
77 {
78 i = -1ULL >> (j0 - 48);
79 if ((i1 & i) == 0)
80 return x; /* x is integral */
81 if (i0 < 0)
82 {
83 if (j0 == 48)
84 i0 += 1;
85 else
86 {
87 j = i1 + (1LL << (112 - j0));
88 if (j < i1)
89 i0 += 1 ; /* got a carry */
90 i1 = j;
91 }
92 }
93 i1 &= (~i);
94 }
95 SET_LDOUBLE_WORDS64 (x, i0, i1);
96 return x;
97 #endif /* ! USE_FLOORL_BUILTIN */
98 }
99 libm_alias_ldouble (__floor, floor)
100