| File: | ecl/utility/src/ECLRawDataHadron.cc |
| Warning: | line 48, column 5 Value stored to 'exponent' is never read |
Press '?' to see keyboard shortcuts
Keyboard shortcuts:
| 1 | /************************************************************************** |
| 2 | * basf2 (Belle II Analysis Software Framework) * |
| 3 | * Author: The Belle II Collaboration * |
| 4 | * * |
| 5 | * See git log for contributors and copyright holders. * |
| 6 | * This file is licensed under LGPL-3.0, see LICENSE.md. * |
| 7 | **************************************************************************/ |
| 8 | |
| 9 | #include <ecl/utility/ECLRawDataHadron.h> |
| 10 | |
| 11 | #ifdef ECL_RAW_DATA_HADRON_STANDALONE_BUILD |
| 12 | #include <cstdio> // printf |
| 13 | #include <cstdlib> // exit |
| 14 | #else |
| 15 | #include <framework/logging/Logger.h> |
| 16 | #endif |
| 17 | |
| 18 | /** |
| 19 | * See ecl/utility/include/ECLRawDataHadron.h for details |
| 20 | */ |
| 21 | |
| 22 | namespace Belle2::ECL::RawDataHadron { |
| 23 | |
| 24 | /* Amplitude */ |
| 25 | /* ------------------------------------------------------------------------ */ |
| 26 | |
| 27 | unsigned long long packAmplitude(long long peak_amp) |
| 28 | { |
| 29 | // amplitude packing (from 18 bits int to 14 bits float) |
| 30 | // sign -- not used, 0 bits |
| 31 | // exponent -- 3 bits |
| 32 | // fraction -- 11 bits |
| 33 | if (peak_amp < 0) { |
| 34 | #ifdef ECL_RAW_DATA_HADRON_STANDALONE_BUILD |
| 35 | printf("\n\033[31m"); |
| 36 | printf("%s:%d: Error! Amplitude can never be negative, you have to call this function as packAmplitude(peak_amp + 128).\n", |
| 37 | __FILE__"ecl/utility/src/ECLRawDataHadron.cc", __LINE__37); |
| 38 | printf("\033[0m\n"); |
| 39 | exit(1); |
| 40 | #else |
| 41 | B2FATAL("Amplitude can never be negative, you have to call this function as packAmplitude(peak_amp + 128).")do { { LogVariableStream varStream; varStream << "Amplitude can never be negative, you have to call this function as packAmplitude(peak_amp + 128)." ; Belle2::LogSystem::Instance().sendMessage(Belle2::LogMessage (Belle2::LogConfig::c_Fatal, std::move(varStream), "ecl", __PRETTY_FUNCTION__ , "ecl/utility/src/ECLRawDataHadron.cc", 41, 0)); }; exit(1); } while(false); |
| 42 | #endif |
| 43 | } |
| 44 | unsigned long long exponent; |
| 45 | unsigned long long fraction; |
| 46 | unsigned long long amp_packed = 0; |
| 47 | |
| 48 | exponent = 0; |
Value stored to 'exponent' is never read | |
| 49 | fraction = peak_amp; |
| 50 | |
| 51 | if ((fraction & 0x20000) != 0) |
| 52 | exponent = 7; |
| 53 | else if ((fraction & 0x10000) != 0) |
| 54 | exponent = 6; |
| 55 | else if ((fraction & 0x08000) != 0) |
| 56 | exponent = 5; |
| 57 | else if ((fraction & 0x04000) != 0) |
| 58 | exponent = 4; |
| 59 | else if ((fraction & 0x02000) != 0) |
| 60 | exponent = 3; |
| 61 | else if ((fraction & 0x01000) != 0) |
| 62 | exponent = 2; |
| 63 | else if ((fraction & 0x00800) != 0) |
| 64 | exponent = 1; |
| 65 | else |
| 66 | exponent = 0; |
| 67 | |
| 68 | if (exponent > 0) { |
| 69 | if (exponent > 1) { |
| 70 | fraction += 1 << (exponent - 2); |
| 71 | fraction = (fraction >> (exponent - 1)) - (1 << 11); |
| 72 | } |
| 73 | } |
| 74 | //############################################### |
| 75 | // ACCOUNTING FOR OVERFLOW |
| 76 | //############################################### |
| 77 | // See the comments in packTime function |
| 78 | // for the explanation |
| 79 | //############################################### |
| 80 | if ((fraction & 0x00800) != 0) |
| 81 | fraction -= 1; |
| 82 | |
| 83 | amp_packed = (exponent << 11) | fraction; |
| 84 | return amp_packed; |
| 85 | } |
| 86 | |
| 87 | unsigned long long unpackAmplitude(unsigned long long amp_packed) |
| 88 | { |
| 89 | unsigned int exponent = (amp_packed >> 11) & 0b111; |
| 90 | unsigned int fraction = (amp_packed) & 0b11111111111; |
| 91 | if (exponent == 0) { |
| 92 | return fraction - 128; |
| 93 | } else { |
| 94 | return (1 << (10 + exponent)) + fraction * (1 << (exponent - 1)) - 128; |
| 95 | } |
| 96 | } |
| 97 | |
| 98 | /* Time */ |
| 99 | /* ------------------------------------------------------------------------ */ |
| 100 | |
| 101 | int packTime(int peak_time) |
| 102 | { |
| 103 | // time packing (from 12 bits int to 11 bits float) as per IEEE 754 |
| 104 | // https://en.wikipedia.org/wiki/Double-precision_floating-point_format#IEEE_754_double-precision_binary_floating-point_format:_binary64 |
| 105 | // sign -- 1 bit |
| 106 | // exponent -- 2 bits |
| 107 | // fraction -- 8 bits |
| 108 | unsigned int exponent = 0; |
| 109 | unsigned int sign = 0; |
| 110 | int fraction = peak_time; // time from -2048 to 2047 |
| 111 | if ((fraction & 0x800) != 0) { |
| 112 | sign = 1; |
| 113 | fraction = -fraction; |
| 114 | } |
| 115 | |
| 116 | if ((fraction & 0x400) != 0) |
| 117 | exponent = 3; |
| 118 | else if ((fraction & 0x200) != 0) |
| 119 | exponent = 2; |
| 120 | else if ((fraction & 0x100) != 0) |
| 121 | exponent = 1; |
| 122 | else |
| 123 | exponent = 0; |
| 124 | |
| 125 | |
| 126 | if (exponent > 0) { |
| 127 | if (exponent > 1) { |
| 128 | // Adjust initial value so that the value is rounded to |
| 129 | // closest possible number. |
| 130 | fraction += 1 << (exponent - 2); |
| 131 | } |
| 132 | fraction = (fraction >> (exponent - 1)) - (1 << 8); |
| 133 | //############################################### |
| 134 | // ACCOUNTING FOR OVERFLOW |
| 135 | //############################################### |
| 136 | // In several specific cases, rounding can cause |
| 137 | // the value to overflow, this has to be handled. |
| 138 | // (for example: |
| 139 | // We would like to compress 63 from 5 bits to 3 bits. |
| 140 | // Thus, we divide 63 by 2^(5-3) == 4 |
| 141 | // 63 + (4 / 2) == 65 # apply rounding |
| 142 | // 65 / 4 == 16 # divide by 2^(5-3) |
| 143 | // And 16 will exceed the bit width of 3! |
| 144 | // So we need to account for such cases |
| 145 | //############################################### |
| 146 | if ((fraction & 0x100) != 0) |
| 147 | fraction -= 1; |
| 148 | } |
| 149 | |
| 150 | int peak_time_packed = (sign << 10) | (exponent << 8) | fraction; |
| 151 | return peak_time_packed; |
| 152 | } |
| 153 | |
| 154 | int unpackTime(int time_packed) |
| 155 | { |
| 156 | unsigned int sign = (time_packed >> 10) & 0b1; |
| 157 | unsigned int exponent = (time_packed >> 8) & 0b11; |
| 158 | unsigned int fraction = (time_packed) & 0b11111111; |
| 159 | |
| 160 | int result; |
| 161 | |
| 162 | if (exponent == 0) |
| 163 | result = fraction; |
| 164 | else |
| 165 | result = ((1 << (7 + exponent)) + fraction * (1 << (exponent - 1))); |
| 166 | if (sign == 1) |
| 167 | result = -result; |
| 168 | return result; |
| 169 | } |
| 170 | |
| 171 | /* Hadron fraction */ |
| 172 | /* ------------------------------------------------------------------------ */ |
| 173 | |
| 174 | /** |
| 175 | * @brief Basically the fastest algorithm for approximate integer division (with the precision (1/32)). |
| 176 | * |
| 177 | * Algorithm description |
| 178 | * ===================== |
| 179 | * |
| 180 | * Calculating (n / m) |
| 181 | * |
| 182 | * 1. Determine p \in [0, 18], such that: |
| 183 | * |
| 184 | * ⎛ p ⎞ |
| 185 | * 32 <= ⎝ m / 2 ⎠ < 64 |
| 186 | * |
| 187 | * 2. Define shifted (divided) values n_S, m_S: |
| 188 | * |
| 189 | * p |
| 190 | * n = n / 2 ∈ [0, 63] |
| 191 | * S |
| 192 | * p |
| 193 | * m = m / 2 ∈ [32, 63] |
| 194 | * S |
| 195 | * |
| 196 | * 3. Calculate (n / m) as follows: |
| 197 | * |
| 198 | * \frac{n}{m} = \frac{n_S}{m_S} = n_S \cdot \left( \frac{2^{16}}{m_S} \right) \cdot \frac{1}{2^{16}} |
| 199 | * |
| 200 | * n ⎛ 16 ⎞ |
| 201 | * n S ⎜ 2 ⎟ 1 |
| 202 | * ─ = ── = n ∙ ⎜ ─── ⎟ ∙ ─── |
| 203 | * m m S ⎜ m ⎟ 16 |
| 204 | * S ⎝ S ⎠ 2 |
| 205 | * |
| 206 | * ┌─────────────└───────┘────────────────────────────────┐ |
| 207 | * Since m_S can take only 32 different values, we |
| 208 | * pre-calculate 32 different constants for (2^{16} / m_S) |
| 209 | * |
| 210 | * 4. Correction to improve division accuracy: |
| 211 | * |
| 212 | * Instead of n_S, use (n_S + m_S / 2), this will result in |
| 213 | * correct rounding for the division. |
| 214 | * |
| 215 | */ |
| 216 | int integer_division_32(int dividend, int divisor) |
| 217 | { |
| 218 | if (divisor < 32) |
| 219 | // Division can be done for divisor < 32 but it is meaningless: |
| 220 | // hadron component fit is meaningless for amp < 32 |
| 221 | return 0; |
| 222 | |
| 223 | if (dividend >= (1 << 18) || dividend < 0) { |
| 224 | fprintf(stderrstderr, "\n\033[31m"); |
| 225 | fprintf(stderrstderr, "%s:%d: Error! Dividend outside of expected range: %d\n", __FILE__"ecl/utility/src/ECLRawDataHadron.cc", __LINE__225, dividend); |
| 226 | fprintf(stderrstderr, "\033[0m\n"); |
| 227 | return 0; // exit(1); |
| 228 | } |
| 229 | if (divisor >= (1 << 19)) { |
| 230 | fprintf(stderrstderr, "\n\033[31m"); |
| 231 | fprintf(stderrstderr, "%s:%d: Error! Divisor outside of expected range: %d\n", __FILE__"ecl/utility/src/ECLRawDataHadron.cc", __LINE__231, divisor); |
| 232 | fprintf(stderrstderr, "\033[0m\n"); |
| 233 | return 0; // exit(1); |
| 234 | } |
| 235 | |
| 236 | // while divisor < 32: |
| 237 | // dividend *= 2 |
| 238 | // divisor *= 2 |
| 239 | //############################################### |
| 240 | // GET CORRECT BITSHIFT |
| 241 | //############################################### |
| 242 | int i = 18; |
| 243 | int p = i - 5; |
| 244 | while (i >= 5) { |
| 245 | if ((divisor & (1 << i)) != 0) { |
| 246 | p = (i - 5); |
| 247 | break; |
| 248 | } |
| 249 | i = i - 1; |
| 250 | } |
| 251 | //####################### |
| 252 | // Equivalent math expression: |
| 253 | // |
| 254 | // i = ⎣ log2(divisor) ⎦ |
| 255 | // p = i - 5 |
| 256 | // |
| 257 | //####################### |
| 258 | // Equivalent code (same as a while loop above) |
| 259 | // if (divisor & 0x40000) != 0: |
| 260 | // p = 13 |
| 261 | // elif (divisor & 0x20000) != 0: |
| 262 | // p = 12 |
| 263 | // elif (divisor & 0x10000) != 0: |
| 264 | // p = 11 |
| 265 | // elif (divisor & 0x08000) != 0: |
| 266 | // p = 10 |
| 267 | // ... |
| 268 | // elif (divisor & 0x00020) != 0: |
| 269 | // p = 0 |
| 270 | //####################### |
| 271 | |
| 272 | // NOTE: Because of this multiplication, dividend requires 23 bits. |
| 273 | // The code can be rewritten to manage with 18 bits. |
| 274 | dividend = dividend << 5; |
| 275 | |
| 276 | int n_S = dividend >> p; |
| 277 | int m_S = divisor >> p; |
| 278 | |
| 279 | // The values of round((2^16) / m_S), where m_S is in 32..63 range |
| 280 | const int precalculated_constants[] = { |
| 281 | // round(2**16 / (x+0.5)) for x in range(32, 64) |
| 282 | // ===> |
| 283 | 2016, 1956, 1900, 1846, 1796, 1748, 1702, 1659, |
| 284 | 1618, 1579, 1542, 1507, 1473, 1440, 1409, 1380, |
| 285 | 1351, 1324, 1298, 1273, 1248, 1225, 1202, 1181, |
| 286 | 1160, 1140, 1120, 1101, 1083, 1066, 1049, 1032 |
| 287 | }; |
| 288 | |
| 289 | // n ⎛ 16 ⎞ |
| 290 | // n S ⎜ 2 ⎟ 1 |
| 291 | // ─ = ── = n ∙ ⎜ ─── ⎟ ∙ ─── |
| 292 | // m m S ⎜ m ⎟ 16 |
| 293 | // S ⎝ S ⎠ 2 |
| 294 | |
| 295 | return ((n_S + m_S / 2) * precalculated_constants[m_S - 32]) >> 16; |
| 296 | } |
| 297 | |
| 298 | int packHadronFraction(int A_hadron, int A_total) |
| 299 | { |
| 300 | // The actual expression is ( (A_hadron / A_total + 0.25) / 0.75 ) * 32 |
| 301 | // (for the firmware, dividend and divisor are multiplied by 4 to simplify calculations) |
| 302 | int dividend = 4 * A_hadron + A_total; |
| 303 | if (dividend < 0) return 0; |
| 304 | int packed_fraction = integer_division_32(dividend, 3 * A_total); |
| 305 | return packed_fraction; |
| 306 | } |
| 307 | |
| 308 | double unpackHadronFraction(int fraction_packed) |
| 309 | { |
| 310 | return fraction_packed / 32.0 * 0.75 - 0.25; |
| 311 | } |
| 312 | } |
| 313 |