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428d5830 | 1 | /* ceil function, sparc32 v9 version. |
f7a9f785 | 2 | Copyright (C) 2012-2016 Free Software Foundation, Inc. |
428d5830 DM |
3 | This file is part of the GNU C Library. |
4 | Contributed by David S. Miller <davem@davemloft.net>, 2012. | |
5 | ||
6 | The GNU C Library is free software; you can redistribute it and/or | |
7 | modify it under the terms of the GNU Lesser General Public | |
8 | License as published by the Free Software Foundation; either | |
9 | version 2.1 of the License, or (at your option) any later version. | |
10 | ||
11 | The GNU C Library is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | Lesser General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU Lesser General Public | |
17 | License along with the GNU C Library; if not, see | |
18 | <http://www.gnu.org/licenses/>. */ | |
19 | ||
20 | #include <sysdep.h> | |
33f244f4 | 21 | #include <math_ldbl_opt.h> |
428d5830 DM |
22 | |
23 | /* Since changing the rounding mode is extremely expensive, we | |
d674b76d DM |
24 | try to round up using a method that is rounding mode |
25 | agnostic. | |
26 | ||
27 | We add then subtract (or subtract than add if the initial | |
28 | value was negative) 2**23 to the value, then subtract it | |
29 | back out. | |
30 | ||
31 | This will clear out the fractional portion of the value. | |
32 | One of two things will happen for non-whole initial values. | |
33 | Either the rounding mode will round it up, or it will be | |
34 | rounded down. If the value started out whole, it will be | |
35 | equal after the addition and subtraction. This means we | |
36 | can accurately detect with one test whether we need to add | |
37 | another 1.0 to round it up properly. | |
38 | ||
39 | We pop constants into the FPU registers using the incoming | |
40 | argument stack slots, since this avoid having to use any | |
41 | PIC references. We also thus avoid having to allocate a | |
42 | register window. | |
43 | ||
44 | VIS instructions are used to facilitate the formation of | |
45 | easier constants, and the propagation of the sign bit. */ | |
428d5830 DM |
46 | |
47 | #define TWO_FIFTYTWO 0x43300000 /* 2**52 */ | |
48 | #define ONE_DOT_ZERO 0x3ff00000 /* 1.0 */ | |
49 | ||
50 | #define ZERO %f10 /* 0.0 */ | |
51 | #define SIGN_BIT %f12 /* -0.0 */ | |
52 | ||
53 | ENTRY (__ceil) | |
54 | sethi %hi(TWO_FIFTYTWO), %o2 | |
55 | sllx %o0, 32, %o0 | |
56 | sethi %hi(ONE_DOT_ZERO), %o3 | |
57 | or %o0, %o1, %o0 | |
58 | stx %o0, [%sp + 72] | |
59 | sllx %o2, 32, %o2 | |
60 | fzero ZERO | |
61 | sllx %o3, 32, %o3 | |
62 | ||
63 | ldd [%sp + 72], %f0 | |
64 | fnegd ZERO, SIGN_BIT | |
65 | ||
66 | stx %o2, [%sp + 72] | |
67 | fabsd %f0, %f14 | |
68 | ||
69 | ldd [%sp + 72], %f16 | |
70 | fcmpd %fcc3, %f14, %f16 | |
71 | ||
72 | fmovduge %fcc3, ZERO, %f16 | |
73 | fand %f0, SIGN_BIT, SIGN_BIT | |
74 | ||
75 | for %f16, SIGN_BIT, %f16 | |
76 | faddd %f0, %f16, %f18 | |
77 | fsubd %f18, %f16, %f18 | |
78 | fcmpd %fcc2, %f18, %f0 | |
d6b5aa58 | 79 | stx %o3, [%sp + 72] |
428d5830 | 80 | |
d6b5aa58 | 81 | ldd [%sp + 72], %f20 |
428d5830 DM |
82 | fmovduge %fcc2, ZERO, %f20 |
83 | faddd %f18, %f20, %f0 | |
84 | fabsd %f0, %f0 | |
85 | retl | |
86 | for %f0, SIGN_BIT, %f0 | |
87 | END (__ceil) | |
88 | weak_alias (__ceil, ceil) | |
33f244f4 DM |
89 | |
90 | #if LONG_DOUBLE_COMPAT(libm, GLIBC_2_0) | |
91 | compat_symbol (libm, __ceil, ceill, GLIBC_2_0) | |
92 | #endif |