| 236 | } |
| 237 | |
| 238 | void grab(ULONG* key, |
| 239 | const unsigned pMax, const int bias, const unsigned decSize, |
| 240 | unsigned char* bcd, int& sign, int& exp, decClass& cl) |
| 241 | { |
| 242 | exp = *key++; |
| 243 | sign = 0; |
| 244 | |
| 245 | if (exp == MAX_SLONG || exp == ~MAX_SLONG) // special value |
| 246 | { |
| 247 | unsigned dig = decSize / sizeof(ULONG); |
| 248 | fb_assert(!(decSize % sizeof(ULONG))); |
| 249 | ULONG offset = key[dig - 1]; |
| 250 | |
| 251 | if (exp == ~MAX_SLONG) |
| 252 | { |
| 253 | sign = DECFLOAT_Sign; |
| 254 | offset = ~offset; |
| 255 | } |
| 256 | |
| 257 | offset = MAX_SLONG - offset; |
| 258 | switch(offset) |
| 259 | { |
| 260 | case OFF_inf: |
| 261 | cl = sign ? DEC_CLASS_NEG_INF : DEC_CLASS_POS_INF; |
| 262 | break; |
| 263 | case OFF_snan: |
| 264 | cl = DEC_CLASS_SNAN; |
| 265 | break; |
| 266 | case OFF_nan: |
| 267 | cl = DEC_CLASS_QNAN; |
| 268 | break; |
| 269 | default: |
| 270 | (Arg::Gds(isc_random) << "Invalid class of special decfloat value in sort key").raise(); |
| 271 | } |
| 272 | |
| 273 | return; |
| 274 | } |
| 275 | |
| 276 | // normal value |
| 277 | // here we ignore differences in class for SUBNORMAL, ZERO and NEG |
| 278 | cl = DEC_CLASS_POS_NORMAL; |
| 279 | |
| 280 | // parse exp |
| 281 | if (exp < 0) |
| 282 | { |
| 283 | sign = DECFLOAT_Sign; |
| 284 | exp = -exp; |
| 285 | } |
| 286 | |
| 287 | if (exp != 0) |
| 288 | exp -= (bias + 2); |
| 289 | |
| 290 | // convert from SLONG |
| 291 | for (int i = pMax; i--;) |
| 292 | { |
| 293 | int c = i / 9; |
| 294 | bcd[i] = key[c] % 10; |
| 295 | key[c] /= 10; |