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d4f93cf4 | 1 | /* |
d4f93cf4 AG |
2 | This file is part of Smoothie (http://smoothieware.org/) |
3 | The motion control part is heavily based on Grbl (https://github.com/simen/grbl) | |
4 | ||
5 | Smoothie is free software: you can redistribute it and/or modify it under | |
6 | the terms of the GNU General Public License as published by the Free | |
7 | Software Foundation, either version 3 of the License, or (at your option) | |
8 | any later version. | |
9 | ||
10 | Smoothie is distributed in the hope that it will be useful, but WITHOUT ANY | |
11 | WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS | |
12 | FOR A PARTICULAR PURPOSE. See the GNU General Public License for more | |
13 | details. | |
14 | ||
15 | You should have received a copy of the GNU General Public License along | |
16 | with Smoothie. If not, see <http://www.gnu.org/licenses/>. | |
17 | */ | |
18 | /* Calculates Fletcher Checksum at compile time using recursive macros. */ | |
19 | #ifndef _CHECKSUM_MACRO_H_ | |
20 | #define _CHECKSUM_MACRO_H_ | |
21 | ||
734fa037 AG |
22 | /* There are two compile time checksumming approaches in this file. One uses |
23 | the C preprocessor and the other uses new C++11 features. They should both | |
24 | do the same thing but my current compiler, GCC 4.7, doesn't always do the | |
25 | constant folding for the C++ approach and this causes code bloat. The C | |
26 | preprocessor approach can currently generate the exact same code in | |
27 | Checked/Release builds as the old method of pre-calculating checksums by | |
28 | hand and pasting them into the code. | |
29 | ||
30 | Keeping both versions here: the active C version and the C++ version | |
31 | that we should switch to later if newer compilers do the required constant | |
32 | folding (maybe there are optimization flags to help here.) | |
33 | */ | |
34 | #ifdef CHECKSUM_USE_CPP | |
35 | ||
36 | /* Cool C++11 approach contributed by bgamari on smoothieware IRC channel. */ | |
37 | constexpr uint16_t checksum(const char* s, size_t n, size_t i, uint16_t sum1, uint16_t sum2) { | |
38 | return (i <= n) ? checksum(s, n, i+1, (sum1 + s[i]) % 255, (sum2 + sum1) % 255) : ((sum2 << 8) | sum1); | |
39 | } | |
40 | ||
41 | constexpr uint16_t operator "" _checksum(const char* s, size_t n) { | |
42 | return checksum(s, n, 0, 0, 0); | |
43 | } | |
44 | ||
45 | #define CHECKSUM(X) X##_checksum | |
46 | ||
47 | #else | |
48 | ||
49 | /* Adam Green's old and crusty C approach. */ | |
d4f93cf4 AG |
50 | /* Recursively define SUM1, the basic checksum % 255 */ |
51 | #define SUM1_1(X) ((X)[0] % 255) | |
52 | #define SUM1_2(X) ((SUM1_1(X) + (X)[1]) % 255) | |
53 | #define SUM1_3(X) ((SUM1_2(X) + (X)[2]) % 255) | |
54 | #define SUM1_4(X) ((SUM1_3(X) + (X)[3]) % 255) | |
55 | #define SUM1_5(X) ((SUM1_4(X) + (X)[4]) % 255) | |
56 | #define SUM1_6(X) ((SUM1_5(X) + (X)[5]) % 255) | |
57 | #define SUM1_7(X) ((SUM1_6(X) + (X)[6]) % 255) | |
58 | #define SUM1_8(X) ((SUM1_7(X) + (X)[7]) % 255) | |
59 | #define SUM1_9(X) ((SUM1_8(X) + (X)[8]) % 255) | |
60 | #define SUM1_10(X) ((SUM1_9(X) + (X)[9]) % 255) | |
61 | #define SUM1_11(X) ((SUM1_10(X) + (X)[10]) % 255) | |
62 | #define SUM1_12(X) ((SUM1_11(X) + (X)[11]) % 255) | |
63 | #define SUM1_13(X) ((SUM1_12(X) + (X)[12]) % 255) | |
64 | #define SUM1_14(X) ((SUM1_13(X) + (X)[13]) % 255) | |
65 | #define SUM1_15(X) ((SUM1_14(X) + (X)[14]) % 255) | |
66 | #define SUM1_16(X) ((SUM1_15(X) + (X)[15]) % 255) | |
67 | #define SUM1_17(X) ((SUM1_16(X) + (X)[16]) % 255) | |
68 | #define SUM1_18(X) ((SUM1_17(X) + (X)[17]) % 255) | |
69 | #define SUM1_19(X) ((SUM1_18(X) + (X)[18]) % 255) | |
70 | #define SUM1_20(X) ((SUM1_19(X) + (X)[19]) % 255) | |
71 | #define SUM1_21(X) ((SUM1_20(X) + (X)[20]) % 255) | |
72 | #define SUM1_22(X) ((SUM1_21(X) + (X)[21]) % 255) | |
73 | #define SUM1_23(X) ((SUM1_22(X) + (X)[22]) % 255) | |
74 | #define SUM1_24(X) ((SUM1_23(X) + (X)[23]) % 255) | |
75 | #define SUM1_25(X) ((SUM1_24(X) + (X)[24]) % 255) | |
76 | #define SUM1_26(X) ((SUM1_25(X) + (X)[25]) % 255) | |
77 | #define SUM1_27(X) ((SUM1_26(X) + (X)[26]) % 255) | |
78 | #define SUM1_28(X) ((SUM1_27(X) + (X)[27]) % 255) | |
79 | #define SUM1_29(X) ((SUM1_28(X) + (X)[28]) % 255) | |
80 | #define SUM1_30(X) ((SUM1_29(X) + (X)[29]) % 255) | |
81 | #define SUM1_31(X) ((SUM1_30(X) + (X)[30]) % 255) | |
82 | #define SUM1_32(X) ((SUM1_31(X) + (X)[31]) % 255) | |
83 | ||
84 | /* Recursively define SUM2, the sum of SUM1s % 255 */ | |
85 | #define SUM2_1(X) (SUM1_1(X) % 255) | |
86 | #define SUM2_2(X) ((SUM2_1(X) + SUM1_2(X)) % 255) | |
87 | #define SUM2_3(X) ((SUM2_2(X) + SUM1_3(X)) % 255) | |
88 | #define SUM2_4(X) ((SUM2_3(X) + SUM1_4(X)) % 255) | |
89 | #define SUM2_5(X) ((SUM2_4(X) + SUM1_5(X)) % 255) | |
90 | #define SUM2_6(X) ((SUM2_5(X) + SUM1_6(X)) % 255) | |
91 | #define SUM2_7(X) ((SUM2_6(X) + SUM1_7(X)) % 255) | |
92 | #define SUM2_8(X) ((SUM2_7(X) + SUM1_8(X)) % 255) | |
93 | #define SUM2_9(X) ((SUM2_8(X) + SUM1_9(X)) % 255) | |
94 | #define SUM2_10(X) ((SUM2_9(X) + SUM1_10(X)) % 255) | |
95 | #define SUM2_11(X) ((SUM2_10(X) + SUM1_11(X)) % 255) | |
96 | #define SUM2_12(X) ((SUM2_11(X) + SUM1_12(X)) % 255) | |
97 | #define SUM2_13(X) ((SUM2_12(X) + SUM1_13(X)) % 255) | |
98 | #define SUM2_14(X) ((SUM2_13(X) + SUM1_14(X)) % 255) | |
99 | #define SUM2_15(X) ((SUM2_14(X) + SUM1_15(X)) % 255) | |
100 | #define SUM2_16(X) ((SUM2_15(X) + SUM1_16(X)) % 255) | |
101 | #define SUM2_17(X) ((SUM2_16(X) + SUM1_17(X)) % 255) | |
102 | #define SUM2_18(X) ((SUM2_17(X) + SUM1_18(X)) % 255) | |
103 | #define SUM2_19(X) ((SUM2_18(X) + SUM1_19(X)) % 255) | |
104 | #define SUM2_20(X) ((SUM2_19(X) + SUM1_20(X)) % 255) | |
105 | #define SUM2_21(X) ((SUM2_20(X) + SUM1_21(X)) % 255) | |
106 | #define SUM2_22(X) ((SUM2_21(X) + SUM1_22(X)) % 255) | |
107 | #define SUM2_23(X) ((SUM2_22(X) + SUM1_23(X)) % 255) | |
108 | #define SUM2_24(X) ((SUM2_23(X) + SUM1_24(X)) % 255) | |
109 | #define SUM2_25(X) ((SUM2_24(X) + SUM1_25(X)) % 255) | |
110 | #define SUM2_26(X) ((SUM2_25(X) + SUM1_26(X)) % 255) | |
111 | #define SUM2_27(X) ((SUM2_26(X) + SUM1_27(X)) % 255) | |
112 | #define SUM2_28(X) ((SUM2_27(X) + SUM1_28(X)) % 255) | |
113 | #define SUM2_29(X) ((SUM2_28(X) + SUM1_29(X)) % 255) | |
114 | #define SUM2_30(X) ((SUM2_29(X) + SUM1_30(X)) % 255) | |
115 | #define SUM2_31(X) ((SUM2_30(X) + SUM1_31(X)) % 255) | |
116 | #define SUM2_32(X) ((SUM2_31(X) + SUM1_32(X)) % 255) | |
117 | ||
118 | /* Define overall checksum as 16-bit combination of SUM1 in lower 8-bits and SUM2 in upper 8-bits. */ | |
119 | #define CHECKSUM_(SUM1,SUM2) (SUM1) | (SUM2 << 8) | |
120 | #define CHECKSUM_1(X) CHECKSUM_(SUM1_1(X),SUM2_1(X)) | |
121 | #define CHECKSUM_2(X) CHECKSUM_(SUM1_2(X),SUM2_2(X)) | |
122 | #define CHECKSUM_3(X) CHECKSUM_(SUM1_3(X),SUM2_3(X)) | |
123 | #define CHECKSUM_4(X) CHECKSUM_(SUM1_4(X),SUM2_4(X)) | |
124 | #define CHECKSUM_5(X) CHECKSUM_(SUM1_5(X),SUM2_5(X)) | |
125 | #define CHECKSUM_6(X) CHECKSUM_(SUM1_6(X),SUM2_6(X)) | |
126 | #define CHECKSUM_7(X) CHECKSUM_(SUM1_7(X),SUM2_7(X)) | |
127 | #define CHECKSUM_8(X) CHECKSUM_(SUM1_8(X),SUM2_8(X)) | |
128 | #define CHECKSUM_9(X) CHECKSUM_(SUM1_9(X),SUM2_9(X)) | |
129 | #define CHECKSUM_10(X) CHECKSUM_(SUM1_10(X),SUM2_10(X)) | |
130 | #define CHECKSUM_11(X) CHECKSUM_(SUM1_11(X),SUM2_11(X)) | |
131 | #define CHECKSUM_12(X) CHECKSUM_(SUM1_12(X),SUM2_12(X)) | |
132 | #define CHECKSUM_13(X) CHECKSUM_(SUM1_13(X),SUM2_13(X)) | |
133 | #define CHECKSUM_14(X) CHECKSUM_(SUM1_14(X),SUM2_14(X)) | |
134 | #define CHECKSUM_15(X) CHECKSUM_(SUM1_15(X),SUM2_15(X)) | |
135 | #define CHECKSUM_16(X) CHECKSUM_(SUM1_16(X),SUM2_16(X)) | |
136 | #define CHECKSUM_17(X) CHECKSUM_(SUM1_17(X),SUM2_17(X)) | |
137 | #define CHECKSUM_18(X) CHECKSUM_(SUM1_18(X),SUM2_18(X)) | |
138 | #define CHECKSUM_19(X) CHECKSUM_(SUM1_19(X),SUM2_19(X)) | |
139 | #define CHECKSUM_20(X) CHECKSUM_(SUM1_20(X),SUM2_20(X)) | |
140 | #define CHECKSUM_21(X) CHECKSUM_(SUM1_21(X),SUM2_21(X)) | |
141 | #define CHECKSUM_22(X) CHECKSUM_(SUM1_22(X),SUM2_22(X)) | |
142 | #define CHECKSUM_23(X) CHECKSUM_(SUM1_23(X),SUM2_23(X)) | |
143 | #define CHECKSUM_24(X) CHECKSUM_(SUM1_24(X),SUM2_24(X)) | |
144 | #define CHECKSUM_25(X) CHECKSUM_(SUM1_25(X),SUM2_25(X)) | |
145 | #define CHECKSUM_26(X) CHECKSUM_(SUM1_26(X),SUM2_26(X)) | |
146 | #define CHECKSUM_27(X) CHECKSUM_(SUM1_27(X),SUM2_27(X)) | |
147 | #define CHECKSUM_28(X) CHECKSUM_(SUM1_28(X),SUM2_28(X)) | |
148 | #define CHECKSUM_29(X) CHECKSUM_(SUM1_29(X),SUM2_29(X)) | |
149 | #define CHECKSUM_30(X) CHECKSUM_(SUM1_30(X),SUM2_30(X)) | |
150 | #define CHECKSUM_31(X) CHECKSUM_(SUM1_31(X),SUM2_31(X)) | |
151 | #define CHECKSUM_32(X) CHECKSUM_(SUM1_32(X),SUM2_32(X)) | |
152 | ||
153 | #define CHECKSUM(X) (sizeof(X) == 0 ? 0 : \ | |
154 | sizeof(X) == 1 ? 0 : \ | |
155 | sizeof(X) == 2 ? CHECKSUM_1(X) : \ | |
156 | sizeof(X) == 3 ? CHECKSUM_2(X) : \ | |
157 | sizeof(X) == 4 ? CHECKSUM_3(X) : \ | |
158 | sizeof(X) == 5 ? CHECKSUM_4(X) : \ | |
159 | sizeof(X) == 6 ? CHECKSUM_5(X) : \ | |
160 | sizeof(X) == 7 ? CHECKSUM_6(X) : \ | |
161 | sizeof(X) == 8 ? CHECKSUM_7(X) : \ | |
162 | sizeof(X) == 9 ? CHECKSUM_8(X) : \ | |
163 | sizeof(X) == 10 ? CHECKSUM_9(X) : \ | |
164 | sizeof(X) == 11 ? CHECKSUM_10(X) : \ | |
165 | sizeof(X) == 12 ? CHECKSUM_11(X) : \ | |
166 | sizeof(X) == 13 ? CHECKSUM_12(X) : \ | |
167 | sizeof(X) == 14 ? CHECKSUM_13(X) : \ | |
168 | sizeof(X) == 15 ? CHECKSUM_14(X) : \ | |
169 | sizeof(X) == 16 ? CHECKSUM_15(X) : \ | |
170 | sizeof(X) == 17 ? CHECKSUM_16(X) : \ | |
171 | sizeof(X) == 18 ? CHECKSUM_17(X) : \ | |
172 | sizeof(X) == 19 ? CHECKSUM_18(X) : \ | |
173 | sizeof(X) == 20 ? CHECKSUM_19(X) : \ | |
174 | sizeof(X) == 21 ? CHECKSUM_20(X) : \ | |
175 | sizeof(X) == 22 ? CHECKSUM_21(X) : \ | |
176 | sizeof(X) == 23 ? CHECKSUM_22(X) : \ | |
177 | sizeof(X) == 24 ? CHECKSUM_23(X) : \ | |
178 | sizeof(X) == 25 ? CHECKSUM_24(X) : \ | |
179 | sizeof(X) == 26 ? CHECKSUM_25(X) : \ | |
180 | sizeof(X) == 27 ? CHECKSUM_26(X) : \ | |
181 | sizeof(X) == 28 ? CHECKSUM_27(X) : \ | |
182 | sizeof(X) == 29 ? CHECKSUM_28(X) : \ | |
183 | sizeof(X) == 30 ? CHECKSUM_29(X) : \ | |
184 | sizeof(X) == 31 ? CHECKSUM_30(X) : \ | |
185 | sizeof(X) == 32 ? CHECKSUM_31(X) : \ | |
186 | sizeof(X) == 33 ? CHECKSUM_32(X) : \ | |
187 | 0xFFFF) | |
734fa037 | 188 | #endif |
d4f93cf4 AG |
189 | |
190 | #endif /* _CHECKSUM_MACRO_H_ */ |