]>
Commit | Line | Data |
---|---|---|
dbc9f6c6 | 1 | /* Compute remainder and a congruent to the quotient. |
4239f144 | 2 | Copyright (C) 1997-2018 Free Software Foundation, Inc. |
dbc9f6c6 JJ |
3 | This file is part of the GNU C Library. |
4 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997 and | |
5 | Jakub Jelinek <jj@ultra.linux.cz>, 1999. | |
6 | ||
7 | The GNU C Library is free software; you can redistribute it and/or | |
8 | modify it under the terms of the GNU Lesser General Public | |
9 | License as published by the Free Software Foundation; either | |
10 | version 2.1 of the License, or (at your option) any later version. | |
11 | ||
12 | The GNU C Library is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | Lesser General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU Lesser General Public | |
4239f144 JM |
18 | License along with the GNU C Library; if not, see |
19 | <http://www.gnu.org/licenses/>. */ | |
dbc9f6c6 JJ |
20 | |
21 | #include "quadmath-imp.h" | |
22 | ||
dbc9f6c6 JJ |
23 | static const __float128 zero = 0.0; |
24 | ||
25 | ||
26 | __float128 | |
27 | remquoq (__float128 x, __float128 y, int *quo) | |
28 | { | |
29 | int64_t hx,hy; | |
d6713cb8 | 30 | uint64_t sx,lx,ly,qs; |
dbc9f6c6 JJ |
31 | int cquo; |
32 | ||
33 | GET_FLT128_WORDS64 (hx, lx, x); | |
34 | GET_FLT128_WORDS64 (hy, ly, y); | |
35 | sx = hx & 0x8000000000000000ULL; | |
36 | qs = sx ^ (hy & 0x8000000000000000ULL); | |
37 | hy &= 0x7fffffffffffffffLL; | |
38 | hx &= 0x7fffffffffffffffLL; | |
39 | ||
40 | /* Purge off exception values. */ | |
41 | if ((hy | ly) == 0) | |
42 | return (x * y) / (x * y); /* y = 0 */ | |
43 | if ((hx >= 0x7fff000000000000LL) /* x not finite */ | |
44 | || ((hy >= 0x7fff000000000000LL) /* y is NaN */ | |
45 | && (((hy - 0x7fff000000000000LL) | ly) != 0))) | |
46 | return (x * y) / (x * y); | |
47 | ||
48 | if (hy <= 0x7ffbffffffffffffLL) | |
49 | x = fmodq (x, 8 * y); /* now x < 8y */ | |
1eba0867 | 50 | |
dbc9f6c6 JJ |
51 | if (((hx - hy) | (lx - ly)) == 0) |
52 | { | |
53 | *quo = qs ? -1 : 1; | |
54 | return zero * x; | |
55 | } | |
56 | ||
57 | x = fabsq (x); | |
58 | y = fabsq (y); | |
59 | cquo = 0; | |
60 | ||
1eba0867 | 61 | if (hy <= 0x7ffcffffffffffffLL && x >= 4 * y) |
dbc9f6c6 JJ |
62 | { |
63 | x -= 4 * y; | |
64 | cquo += 4; | |
65 | } | |
1eba0867 | 66 | if (hy <= 0x7ffdffffffffffffLL && x >= 2 * y) |
dbc9f6c6 JJ |
67 | { |
68 | x -= 2 * y; | |
69 | cquo += 2; | |
70 | } | |
71 | ||
72 | if (hy < 0x0002000000000000LL) | |
73 | { | |
74 | if (x + x > y) | |
75 | { | |
76 | x -= y; | |
77 | ++cquo; | |
78 | if (x + x >= y) | |
79 | { | |
80 | x -= y; | |
81 | ++cquo; | |
82 | } | |
83 | } | |
84 | } | |
85 | else | |
86 | { | |
87 | __float128 y_half = 0.5Q * y; | |
88 | if (x > y_half) | |
89 | { | |
90 | x -= y; | |
91 | ++cquo; | |
92 | if (x >= y_half) | |
93 | { | |
94 | x -= y; | |
95 | ++cquo; | |
96 | } | |
97 | } | |
98 | } | |
99 | ||
100 | *quo = qs ? -cquo : cquo; | |
101 | ||
1eba0867 | 102 | /* Ensure correct sign of zero result in round-downward mode. */ |
4239f144 JM |
103 | if (x == 0) |
104 | x = 0; | |
dbc9f6c6 JJ |
105 | if (sx) |
106 | x = -x; | |
107 | return x; | |
108 | } |