1 | /*****************************************************************************/ |
2 | /* */ |
3 | /* bitops.c */ |
4 | /* */ |
5 | /* Single bit operations */ |
6 | /* */ |
7 | /* */ |
8 | /* */ |
9 | /* (C) 1998 Ullrich von Bassewitz */ |
10 | /* Wacholderweg 14 */ |
11 | /* D-70597 Stuttgart */ |
12 | /* EMail: uz@musoftware.de */ |
13 | /* */ |
14 | /* */ |
15 | /* This software is provided 'as-is', without any expressed or implied */ |
16 | /* warranty. In no event will the authors be held liable for any damages */ |
17 | /* arising from the use of this software. */ |
18 | /* */ |
19 | /* Permission is granted to anyone to use this software for any purpose, */ |
20 | /* including commercial applications, and to alter it and redistribute it */ |
21 | /* freely, subject to the following restrictions: */ |
22 | /* */ |
23 | /* 1. The origin of this software must not be misrepresented; you must not */ |
24 | /* claim that you wrote the original software. If you use this software */ |
25 | /* in a product, an acknowledgment in the product documentation would be */ |
26 | /* appreciated but is not required. */ |
27 | /* 2. Altered source versions must be plainly marked as such, and must not */ |
28 | /* be misrepresented as being the original software. */ |
29 | /* 3. This notice may not be removed or altered from any source */ |
30 | /* distribution. */ |
31 | /* */ |
32 | /*****************************************************************************/ |
33 | |
34 | |
35 | |
36 | #include "bitops.h" |
37 | |
38 | |
39 | |
40 | /*****************************************************************************/ |
41 | /* Code */ |
42 | /*****************************************************************************/ |
43 | |
44 | |
45 | |
46 | unsigned BitFind (unsigned long Val) |
47 | /* Find the first bit that is set in Val. Val must *not* be zero */ |
48 | { |
49 | unsigned long Mask; |
50 | unsigned Bit; |
51 | |
52 | /* Search for the bits */ |
53 | Mask = 1; |
54 | Bit = 0; |
55 | while (1) { |
56 | if (Val & Mask) { |
57 | return Bit; |
58 | } |
59 | Mask <<= 1; |
60 | ++Bit; |
61 | } |
62 | } |
63 | |
64 | |
65 | |
66 | void BitSet (void* Data, unsigned Bit) |
67 | /* Set a bit in a char array */ |
68 | { |
69 | /* Make a char pointer */ |
70 | unsigned char* D = Data; |
71 | |
72 | /* Set the bit */ |
73 | D [Bit / 8] |= 0x01 << (Bit % 8); |
74 | } |
75 | |
76 | |
77 | |
78 | void BitReset (void* Data, unsigned Bit) |
79 | /* Reset a bit in a char array */ |
80 | { |
81 | /* Make a char pointer */ |
82 | unsigned char* D = Data; |
83 | |
84 | /* Set the bit */ |
85 | D [Bit / 8] &= ~(0x01 << (Bit % 8)); |
86 | } |
87 | |
88 | |
89 | |
90 | int BitIsSet (void* Data, unsigned Bit) |
91 | /* Check if a bit is set in a char array */ |
92 | { |
93 | /* Make a char pointer */ |
94 | unsigned char* D = Data; |
95 | |
96 | /* Check the bit state */ |
97 | return (D [Bit / 8] & (0x01 << (Bit % 8))) != 0; |
98 | } |
99 | |
100 | |
101 | |
102 | int BitIsReset (void* Data, unsigned Bit) |
103 | /* Check if a bit is reset in a char array */ |
104 | { |
105 | /* Make a char pointer */ |
106 | unsigned char* D = Data; |
107 | |
108 | /* Check the bit state */ |
109 | return (D [Bit / 8] & (0x01 << (Bit % 8))) == 0; |
110 | } |
111 | |
112 | |
113 | |
114 | void BitMerge (void* Target, const void* Source, unsigned Size) |
115 | /* Merge the bits of two char arrays (that is, do an or for the full array) */ |
116 | { |
117 | /* Make char arrays */ |
118 | unsigned char* T = Target; |
119 | const unsigned char* S = Source; |
120 | |
121 | /* Merge the arrays */ |
122 | while (Size--) { |
123 | *T++ |= *S++; |
124 | } |
125 | } |
126 | |