1 | /* |
1 | /* |
2 | * libecb |
2 | * libecb |
3 | * |
3 | * |
4 | * Copyright (c) 2011 Marc Alexander Lehmann |
4 | * Copyright (©) 2009-2011 Marc Alexander Lehmann |
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5 | * Copyright (©) 2011 Emanuele Giaquinta |
5 | * All rights reserved. |
6 | * All rights reserved. |
6 | * |
7 | * |
7 | * Redistribution and use in source and binary forms, with or without modifica- |
8 | * Redistribution and use in source and binary forms, with or without modifica- |
8 | * tion, are permitted provided that the following conditions are met: |
9 | * tion, are permitted provided that the following conditions are met: |
9 | * |
10 | * |
… | |
… | |
27 | */ |
28 | */ |
28 | |
29 | |
29 | #ifndef ECB_H |
30 | #ifndef ECB_H |
30 | #define ECB_H |
31 | #define ECB_H |
31 | |
32 | |
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33 | #include <inttypes.h> |
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34 | |
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35 | /* many compilers define _GNUC_ to some versions but then only implement |
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36 | * what their idiot authors think are the "more important" extensions, |
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37 | * causing enourmous grief for some better fake benchmark numbers or so. |
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38 | * we try to detect these and simply assume they are not gcc - if they have |
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39 | * an issue with that they should have done it right in the first place. |
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40 | */ |
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41 | #if defined(__INTEL_COMPILER) || defined(__SUNPRO_C) || defined(__llvm__) |
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42 | # define ECB_GCC_VERSION(major,minor) 0 |
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43 | #else |
32 | #define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor))) |
44 | # define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor))) |
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45 | #endif |
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46 | |
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47 | #ifndef __cplusplus |
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48 | # if __STDC_VERSION__ >= 199901L |
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49 | # define ECB_INLINE inline |
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50 | typedef _Bool ecb_bool; |
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51 | # else |
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52 | # define ECB_INLINE inline /* yeah! */ |
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53 | typedef int ecb_bool; |
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54 | # endif |
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55 | #endif |
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56 | |
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57 | #define ECB_CONCAT_(a, b) a ## b |
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58 | #define ECB_CONCAT(a, b) ECB_CONCAT_(a, b) |
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59 | #define ECB_STRINGIFY_(a) # a |
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60 | #define ECB_STRINGIFY(a) ECB_STRINGIFY_(a) |
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61 | |
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62 | #define ECB_HEADER_INLINE static ECB_INLINE |
33 | |
63 | |
34 | #if ECB_GCC_VERSION(3,1) |
64 | #if ECB_GCC_VERSION(3,1) |
35 | # define ecb_attribute(attrlist) __attribute__(attrlist) |
65 | # define ecb_attribute(attrlist) __attribute__(attrlist) |
36 | # define ecb_is_constant(c) __builtin_constant_p (c) |
66 | # define ecb_is_constant(c) __builtin_constant_p (c) |
37 | # define ecb_expect(expr,value) __builtin_expect ((expr),(value)) |
67 | # define ecb_expect(expr,value) __builtin_expect ((expr),(value)) |
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41 | # define ecb_is_constant(c) 0 |
71 | # define ecb_is_constant(c) 0 |
42 | # define ecb_expect(expr,value) (expr) |
72 | # define ecb_expect(expr,value) (expr) |
43 | # define ecb_prefetch(addr,rw,locality) |
73 | # define ecb_prefetch(addr,rw,locality) |
44 | #endif |
74 | #endif |
45 | |
75 | |
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76 | /* no emulation for ecb_decltype */ |
46 | #if ECB_GCC_VERSION(4,5) |
77 | #if ECB_GCC_VERSION(4,5) |
47 | # define ecb_decltype(x) __decltype(x) |
78 | # define ecb_decltype(x) __decltype(x) |
48 | #elif ECB_GCC_VERSION(3,0) |
79 | #elif ECB_GCC_VERSION(3,0) |
49 | # define ecb_decltype(x) typeof(x) |
80 | # define ecb_decltype(x) typeof(x) |
50 | #endif |
81 | #endif |
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52 | #define ecb_noinline ecb_attribute ((noinline)) |
83 | #define ecb_noinline ecb_attribute ((noinline)) |
53 | #define ecb_noreturn ecb_attribute ((noreturn)) |
84 | #define ecb_noreturn ecb_attribute ((noreturn)) |
54 | #define ecb_unused ecb_attribute ((unused)) |
85 | #define ecb_unused ecb_attribute ((unused)) |
55 | #define ecb_const ecb_attribute ((const)) |
86 | #define ecb_const ecb_attribute ((const)) |
56 | #define ecb_pure ecb_attribute ((pure)) |
87 | #define ecb_pure ecb_attribute ((pure)) |
57 | #define ecb_hot ecb_attribute ((hot)) // 4.3 |
88 | #define ecb_hot ecb_attribute ((hot)) /* 4.3 */ |
58 | #define ecb_cold ecb_attribute ((cold)) // 4.3 |
89 | #define ecb_cold ecb_attribute ((cold)) /* 4.3 */ |
59 | |
90 | |
60 | #if ECB_GCC_VERSION(4,5) |
91 | /* put into ifs if you are very sure that the expression */ |
61 | # define ecb_unreachable() __builtin_unreachable () |
92 | /* is mostly true or mosty false. note that these return */ |
62 | #else |
93 | /* booleans, not the expression. */ |
63 | // this seems to work fine, but gcc always emits a warning for it :/ |
94 | #define ecb_unlikely(expr) ecb_expect (!!(expr), 0) |
64 | static inline void ecb_unreachable () ecb_attribute ((noreturn)); |
95 | #define ecb_likely(expr) ecb_expect (!!(expr), 1) |
65 | static inline void ecb_unreachable () { } |
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66 | #endif |
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67 | |
96 | |
68 | // put into ifs if you are very sure that the expression |
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69 | // is mostly true or mosty false. note that these return |
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70 | // booleans, not the expression. |
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71 | #define ecb_expect_false(expr) ecb_expect ((expr) ? 1 : 0, 0) |
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72 | #define ecb_expect_true(expr) ecb_expect ((expr) ? 1 : 0, 1) |
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73 | |
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74 | // try to tell the compiler that some condition is definitely true |
97 | /* try to tell the compiler that some condition is definitely true */ |
75 | #define ecb_assume(cond) do { if (!(cond)) unreachable (); } while (0) |
98 | #define ecb_assume(cond) do { if (!(cond)) unreachable (); } while (0) |
76 | |
99 | |
77 | // count trailing zero bits and count # of one bits |
100 | /* count trailing zero bits and count # of one bits */ |
78 | #if ECB_GCC_VERSION(3,4) |
101 | #if ECB_GCC_VERSION(3,4) |
79 | static inline int ecb_ctz (unsigned int x) { return __builtin_ctz (x); } |
102 | ECB_HEADER_INLINE int ecb_ctz32 (uint32_t x) { return __builtin_ctz (x); } |
80 | static inline int ecb_popcount (unsigned int x) { return __builtin_popcount (x); } |
103 | ECB_HEADER_INLINE int ecb_popcount32 (uint32_t x) { return __builtin_popcount (x); } |
81 | #else |
104 | #else |
82 | static int ecb_ctz (unsigned int x) ecb_const |
105 | ECB_HEADER_INLINE |
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106 | ecb_ctz32 (uint32_t x) ecb_const |
83 | { |
107 | { |
84 | int r = 0; |
108 | int r = 0; |
85 | |
109 | |
86 | x &= -x; // this isolates the lowest bit |
110 | x &= -x; /* this isolates the lowest bit */ |
87 | |
111 | |
88 | if (x & 0xaaaaaaaa) r += 1; |
112 | if (x & 0xaaaaaaaa) r += 1; |
89 | if (x & 0xcccccccc) r += 2; |
113 | if (x & 0xcccccccc) r += 2; |
90 | if (x & 0xf0f0f0f0) r += 4; |
114 | if (x & 0xf0f0f0f0) r += 4; |
91 | if (x & 0xff00ff00) r += 8; |
115 | if (x & 0xff00ff00) r += 8; |
92 | if (x & 0xffff0000) r += 16; |
116 | if (x & 0xffff0000) r += 16; |
93 | |
117 | |
94 | return r; |
118 | return r; |
95 | } |
119 | } |
96 | |
120 | |
97 | static int ecb_popcount (unsigned int x) ecb_const |
121 | ECB_HEADER_INLINE |
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122 | ecb_popcount32 (uint32_t x) ecb_const |
98 | { |
123 | { |
99 | x -= (x >> 1) & 0x55555555; |
124 | x -= (x >> 1) & 0x55555555; |
100 | x = ((x >> 2) & 0x33333333) + (x & 0x33333333); |
125 | x = ((x >> 2) & 0x33333333) + (x & 0x33333333); |
101 | x = ((x >> 4) + x) & 0x0f0f0f0f; |
126 | x = ((x >> 4) + x) & 0x0f0f0f0f; |
102 | x *= 0x01010101; |
127 | x *= 0x01010101; |
103 | |
128 | |
104 | return x >> 24; |
129 | return x >> 24; |
105 | } |
130 | } |
106 | #endif |
131 | #endif |
107 | |
132 | |
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133 | #if ECB_GCC_VERSION(4,3) |
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134 | ECB_GCC_VERSION uint32_t ecb_bswap32 (uint32_t x) { return __builtin_bswap32 (x); } |
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135 | #else |
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136 | ECB_GCC_VERSION uint32_t |
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137 | ecb_bswap32 (uint32_t x) |
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138 | { |
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139 | return (x >> 24) |
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140 | | ((x >> 8) & 0x0000ff00) |
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141 | | ((x << 8) & 0x00ff0000) |
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142 | | (x << 24); |
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143 | } |
108 | #endif |
144 | #endif |
109 | |
145 | |
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146 | #if ECB_GCC_VERSION(4,5) |
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147 | # define ecb_unreachable() __builtin_unreachable () |
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148 | #else |
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149 | /* this seems to work fine, but gcc always emits a warning for it :/ */ |
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150 | ECB_HEADER_INLINE void ecb_unreachable () ecb_attribute ((noreturn)); |
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151 | ECB_HEADER_INLINE void ecb_unreachable () { } |
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152 | #endif |
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153 | |
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154 | ECB_HEADER_INLINE unsigned char |
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155 | ecb_byteorder_helper () ecb_const |
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156 | { |
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157 | const uint32_t u = 0x11223344; |
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158 | return *(unsigned char *)&u; |
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159 | } |
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160 | |
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161 | ECB_HEADER_INLINE ecb_bool ecb_big_endian () ecb_const { return ecb_byteorder_helper () == 0x11; }; |
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162 | ECB_HEADER_INLINE ecb_bool ecb_little_endian () ecb_const { return ecb_byteorder_helper () == 0x44; }; |
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163 | |
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164 | #if ecb_cplusplus_does_not_suck |
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165 | // does not work for local types (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm) |
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166 | template<typename T, int N> |
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167 | static inline int ecb_array_length (const T (&arr)[N]) |
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168 | { |
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169 | return N; |
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170 | } |
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171 | #else |
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172 | #define ecb_array_length(name) (sizeof (name) / sizeof (name [0])) |
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173 | #endif |
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174 | |
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175 | ECB_INLINE uint32_t |
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176 | ecb_rotr32 (uint32_t x, unsigned int count) |
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177 | { |
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178 | return (x << (32 - count)) | (x >> count); |
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179 | } |
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180 | |
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181 | ECB_INLINE uint32_t |
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182 | ecb_rotl32 (uint32_t x, unsigned int count) |
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183 | { |
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184 | return (x >> (32 - count)) | (x << count); |
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185 | } |
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186 | |
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187 | #endif |
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188 | |