]>
Commit | Line | Data |
---|---|---|
bc9f6000 | 1 | /* Compute remainder and a congruent to the quotient. |
04277e02 | 2 | Copyright (C) 1997-2019 Free Software Foundation, Inc. |
bc9f6000 UD |
3 | This file is part of the GNU C Library. |
4 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. | |
5 | ||
6 | The GNU C Library is free software; you can redistribute it and/or | |
41bdb6e2 AJ |
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. | |
bc9f6000 UD |
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 | |
41bdb6e2 | 14 | Lesser General Public License for more details. |
bc9f6000 | 15 | |
41bdb6e2 | 16 | You should have received a copy of the GNU Lesser General Public |
59ba27a6 | 17 | License along with the GNU C Library; if not, see |
5a82c748 | 18 | <https://www.gnu.org/licenses/>. */ |
bc9f6000 UD |
19 | |
20 | #include <math.h> | |
21 | ||
1ed0291c | 22 | #include <math_private.h> |
bc9f6000 UD |
23 | |
24 | ||
25 | static const float zero = 0.0; | |
2f49ce7d | 26 | #include <libm-alias-float.h> |
bc9f6000 UD |
27 | |
28 | ||
29 | float | |
30 | __remquof (float x, float y, int *quo) | |
31 | { | |
34b402e5 | 32 | int32_t hx,hy; |
24ab7723 | 33 | uint32_t sx; |
34b402e5 | 34 | int cquo, qs; |
bc9f6000 UD |
35 | |
36 | GET_FLOAT_WORD (hx, x); | |
34b402e5 | 37 | GET_FLOAT_WORD (hy, y); |
bc9f6000 | 38 | sx = hx & 0x80000000; |
34b402e5 UD |
39 | qs = sx ^ (hy & 0x80000000); |
40 | hy &= 0x7fffffff; | |
bc9f6000 UD |
41 | hx &= 0x7fffffff; |
42 | ||
43 | /* Purge off exception values. */ | |
34b402e5 UD |
44 | if (hy == 0) |
45 | return (x * y) / (x * y); /* y = 0 */ | |
bc9f6000 | 46 | if ((hx >= 0x7f800000) /* x not finite */ |
34b402e5 UD |
47 | || (hy > 0x7f800000)) /* y is NaN */ |
48 | return (x * y) / (x * y); | |
bc9f6000 | 49 | |
34b402e5 | 50 | if (hy <= 0x7dffffff) |
63551311 | 51 | x = __ieee754_fmodf (x, 8 * y); /* now x < 8y */ |
bc9f6000 | 52 | |
34b402e5 | 53 | if ((hx - hy) == 0) |
bc9f6000 UD |
54 | { |
55 | *quo = qs ? -1 : 1; | |
56 | return zero * x; | |
57 | } | |
58 | ||
59 | x = fabsf (x); | |
34b402e5 | 60 | y = fabsf (y); |
bc9f6000 UD |
61 | cquo = 0; |
62 | ||
a820f9b3 | 63 | if (hy <= 0x7e7fffff && x >= 4 * y) |
bc9f6000 | 64 | { |
34b402e5 | 65 | x -= 4 * y; |
63551311 UD |
66 | cquo += 4; |
67 | } | |
a820f9b3 | 68 | if (hy <= 0x7effffff && x >= 2 * y) |
63551311 UD |
69 | { |
70 | x -= 2 * y; | |
bc9f6000 UD |
71 | cquo += 2; |
72 | } | |
bc9f6000 | 73 | |
34b402e5 | 74 | if (hy < 0x01000000) |
bc9f6000 | 75 | { |
34b402e5 | 76 | if (x + x > y) |
bc9f6000 | 77 | { |
34b402e5 | 78 | x -= y; |
d705269e | 79 | ++cquo; |
34b402e5 | 80 | if (x + x >= y) |
63551311 UD |
81 | { |
82 | x -= y; | |
83 | ++cquo; | |
84 | } | |
bc9f6000 UD |
85 | } |
86 | } | |
87 | else | |
88 | { | |
34b402e5 | 89 | float y_half = 0.5 * y; |
63551311 | 90 | if (x > y_half) |
bc9f6000 | 91 | { |
34b402e5 | 92 | x -= y; |
d705269e | 93 | ++cquo; |
34b402e5 | 94 | if (x >= y_half) |
63551311 UD |
95 | { |
96 | x -= y; | |
97 | ++cquo; | |
98 | } | |
bc9f6000 UD |
99 | } |
100 | } | |
101 | ||
102 | *quo = qs ? -cquo : cquo; | |
103 | ||
ce8fc784 JM |
104 | /* Ensure correct sign of zero result in round-downward mode. */ |
105 | if (x == 0.0f) | |
106 | x = 0.0f; | |
63551311 UD |
107 | if (sx) |
108 | x = -x; | |
bc9f6000 UD |
109 | return x; |
110 | } | |
2f49ce7d | 111 | libm_alias_float (__remquo, remquo) |