Mercurial > hg > CbC > CbC_gcc
comparison libquadmath/math/remquoq.c @ 68:561a7518be6b
update gcc-4.6
author | Nobuyasu Oshiro <dimolto@cr.ie.u-ryukyu.ac.jp> |
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date | Sun, 21 Aug 2011 07:07:55 +0900 |
parents | |
children | 04ced10e8804 |
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67:f6334be47118 | 68:561a7518be6b |
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1 /* Compute remainder and a congruent to the quotient. | |
2 Copyright (C) 1997, 1999, 2002 Free Software Foundation, Inc. | |
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 | |
18 License along with the GNU C Library; if not, write to the Free | |
19 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA | |
20 02111-1307 USA. */ | |
21 | |
22 #include "quadmath-imp.h" | |
23 | |
24 | |
25 static const __float128 zero = 0.0; | |
26 | |
27 | |
28 __float128 | |
29 remquoq (__float128 x, __float128 y, int *quo) | |
30 { | |
31 int64_t hx,hy; | |
32 uint64_t sx,lx,ly,qs; | |
33 int cquo; | |
34 | |
35 GET_FLT128_WORDS64 (hx, lx, x); | |
36 GET_FLT128_WORDS64 (hy, ly, y); | |
37 sx = hx & 0x8000000000000000ULL; | |
38 qs = sx ^ (hy & 0x8000000000000000ULL); | |
39 hy &= 0x7fffffffffffffffLL; | |
40 hx &= 0x7fffffffffffffffLL; | |
41 | |
42 /* Purge off exception values. */ | |
43 if ((hy | ly) == 0) | |
44 return (x * y) / (x * y); /* y = 0 */ | |
45 if ((hx >= 0x7fff000000000000LL) /* x not finite */ | |
46 || ((hy >= 0x7fff000000000000LL) /* y is NaN */ | |
47 && (((hy - 0x7fff000000000000LL) | ly) != 0))) | |
48 return (x * y) / (x * y); | |
49 | |
50 if (hy <= 0x7ffbffffffffffffLL) | |
51 x = fmodq (x, 8 * y); /* now x < 8y */ | |
52 | |
53 if (((hx - hy) | (lx - ly)) == 0) | |
54 { | |
55 *quo = qs ? -1 : 1; | |
56 return zero * x; | |
57 } | |
58 | |
59 x = fabsq (x); | |
60 y = fabsq (y); | |
61 cquo = 0; | |
62 | |
63 if (x >= 4 * y) | |
64 { | |
65 x -= 4 * y; | |
66 cquo += 4; | |
67 } | |
68 if (x >= 2 * y) | |
69 { | |
70 x -= 2 * y; | |
71 cquo += 2; | |
72 } | |
73 | |
74 if (hy < 0x0002000000000000LL) | |
75 { | |
76 if (x + x > y) | |
77 { | |
78 x -= y; | |
79 ++cquo; | |
80 if (x + x >= y) | |
81 { | |
82 x -= y; | |
83 ++cquo; | |
84 } | |
85 } | |
86 } | |
87 else | |
88 { | |
89 __float128 y_half = 0.5Q * y; | |
90 if (x > y_half) | |
91 { | |
92 x -= y; | |
93 ++cquo; | |
94 if (x >= y_half) | |
95 { | |
96 x -= y; | |
97 ++cquo; | |
98 } | |
99 } | |
100 } | |
101 | |
102 *quo = qs ? -cquo : cquo; | |
103 | |
104 if (sx) | |
105 x = -x; | |
106 return x; | |
107 } |