| Rémy Oudompheng | 9146ac1 | 2012-12-06 08:09:17 +0100 | [diff] [blame] | 1 | // run |
| 2 | |
| 3 | // Copyright 2012 The Go Authors. All rights reserved. |
| 4 | // Use of this source code is governed by a BSD-style |
| 5 | // license that can be found in the LICENSE file. |
| 6 | |
| 7 | // Issue 2615: a long chain of else if's causes an overflow |
| 8 | // in the parser stack. |
| 9 | |
| 10 | package main |
| 11 | |
| 12 | // test returns the index of the lowest set bit in a 256-bit vector. |
| 13 | func test(x [4]uint64) int { |
| 14 | if x[0]&(1<<0) != 0 { |
| 15 | return 0 |
| 16 | } else if x[0]&(1<<1) != 0 { |
| 17 | return 1 |
| 18 | } else if x[0]&(1<<2) != 0 { |
| 19 | return 2 |
| 20 | } else if x[0]&(1<<3) != 0 { |
| 21 | return 3 |
| 22 | } else if x[0]&(1<<4) != 0 { |
| 23 | return 4 |
| 24 | } else if x[0]&(1<<5) != 0 { |
| 25 | return 5 |
| 26 | } else if x[0]&(1<<6) != 0 { |
| 27 | return 6 |
| 28 | } else if x[0]&(1<<7) != 0 { |
| 29 | return 7 |
| 30 | } else if x[0]&(1<<8) != 0 { |
| 31 | return 8 |
| 32 | } else if x[0]&(1<<9) != 0 { |
| 33 | return 9 |
| 34 | } else if x[0]&(1<<10) != 0 { |
| 35 | return 10 |
| 36 | } else if x[0]&(1<<11) != 0 { |
| 37 | return 11 |
| 38 | } else if x[0]&(1<<12) != 0 { |
| 39 | return 12 |
| 40 | } else if x[0]&(1<<13) != 0 { |
| 41 | return 13 |
| 42 | } else if x[0]&(1<<14) != 0 { |
| 43 | return 14 |
| 44 | } else if x[0]&(1<<15) != 0 { |
| 45 | return 15 |
| 46 | } else if x[0]&(1<<16) != 0 { |
| 47 | return 16 |
| 48 | } else if x[0]&(1<<17) != 0 { |
| 49 | return 17 |
| 50 | } else if x[0]&(1<<18) != 0 { |
| 51 | return 18 |
| 52 | } else if x[0]&(1<<19) != 0 { |
| 53 | return 19 |
| 54 | } else if x[0]&(1<<20) != 0 { |
| 55 | return 20 |
| 56 | } else if x[0]&(1<<21) != 0 { |
| 57 | return 21 |
| 58 | } else if x[0]&(1<<22) != 0 { |
| 59 | return 22 |
| 60 | } else if x[0]&(1<<23) != 0 { |
| 61 | return 23 |
| 62 | } else if x[0]&(1<<24) != 0 { |
| 63 | return 24 |
| 64 | } else if x[0]&(1<<25) != 0 { |
| 65 | return 25 |
| 66 | } else if x[0]&(1<<26) != 0 { |
| 67 | return 26 |
| 68 | } else if x[0]&(1<<27) != 0 { |
| 69 | return 27 |
| 70 | } else if x[0]&(1<<28) != 0 { |
| 71 | return 28 |
| 72 | } else if x[0]&(1<<29) != 0 { |
| 73 | return 29 |
| 74 | } else if x[0]&(1<<30) != 0 { |
| 75 | return 30 |
| 76 | } else if x[0]&(1<<31) != 0 { |
| 77 | return 31 |
| 78 | } else if x[0]&(1<<32) != 0 { |
| 79 | return 32 |
| 80 | } else if x[0]&(1<<33) != 0 { |
| 81 | return 33 |
| 82 | } else if x[0]&(1<<34) != 0 { |
| 83 | return 34 |
| 84 | } else if x[0]&(1<<35) != 0 { |
| 85 | return 35 |
| 86 | } else if x[0]&(1<<36) != 0 { |
| 87 | return 36 |
| 88 | } else if x[0]&(1<<37) != 0 { |
| 89 | return 37 |
| 90 | } else if x[0]&(1<<38) != 0 { |
| 91 | return 38 |
| 92 | } else if x[0]&(1<<39) != 0 { |
| 93 | return 39 |
| 94 | } else if x[0]&(1<<40) != 0 { |
| 95 | return 40 |
| 96 | } else if x[0]&(1<<41) != 0 { |
| 97 | return 41 |
| 98 | } else if x[0]&(1<<42) != 0 { |
| 99 | return 42 |
| 100 | } else if x[0]&(1<<43) != 0 { |
| 101 | return 43 |
| 102 | } else if x[0]&(1<<44) != 0 { |
| 103 | return 44 |
| 104 | } else if x[0]&(1<<45) != 0 { |
| 105 | return 45 |
| 106 | } else if x[0]&(1<<46) != 0 { |
| 107 | return 46 |
| 108 | } else if x[0]&(1<<47) != 0 { |
| 109 | return 47 |
| 110 | } else if x[0]&(1<<48) != 0 { |
| 111 | return 48 |
| 112 | } else if x[0]&(1<<49) != 0 { |
| 113 | return 49 |
| 114 | } else if x[0]&(1<<50) != 0 { |
| 115 | return 50 |
| 116 | } else if x[0]&(1<<51) != 0 { |
| 117 | return 51 |
| 118 | } else if x[0]&(1<<52) != 0 { |
| 119 | return 52 |
| 120 | } else if x[0]&(1<<53) != 0 { |
| 121 | return 53 |
| 122 | } else if x[0]&(1<<54) != 0 { |
| 123 | return 54 |
| 124 | } else if x[0]&(1<<55) != 0 { |
| 125 | return 55 |
| 126 | } else if x[0]&(1<<56) != 0 { |
| 127 | return 56 |
| 128 | } else if x[0]&(1<<57) != 0 { |
| 129 | return 57 |
| 130 | } else if x[0]&(1<<58) != 0 { |
| 131 | return 58 |
| 132 | } else if x[0]&(1<<59) != 0 { |
| 133 | return 59 |
| 134 | } else if x[0]&(1<<60) != 0 { |
| 135 | return 60 |
| 136 | } else if x[0]&(1<<61) != 0 { |
| 137 | return 61 |
| 138 | } else if x[0]&(1<<62) != 0 { |
| 139 | return 62 |
| 140 | } else if x[0]&(1<<63) != 0 { |
| 141 | return 63 |
| 142 | } else if x[1]&(1<<0) != 0 { |
| 143 | return 64 |
| 144 | } else if x[1]&(1<<1) != 0 { |
| 145 | return 65 |
| 146 | } else if x[1]&(1<<2) != 0 { |
| 147 | return 66 |
| 148 | } else if x[1]&(1<<3) != 0 { |
| 149 | return 67 |
| 150 | } else if x[1]&(1<<4) != 0 { |
| 151 | return 68 |
| 152 | } else if x[1]&(1<<5) != 0 { |
| 153 | return 69 |
| 154 | } else if x[1]&(1<<6) != 0 { |
| 155 | return 70 |
| 156 | } else if x[1]&(1<<7) != 0 { |
| 157 | return 71 |
| 158 | } else if x[1]&(1<<8) != 0 { |
| 159 | return 72 |
| 160 | } else if x[1]&(1<<9) != 0 { |
| 161 | return 73 |
| 162 | } else if x[1]&(1<<10) != 0 { |
| 163 | return 74 |
| 164 | } else if x[1]&(1<<11) != 0 { |
| 165 | return 75 |
| 166 | } else if x[1]&(1<<12) != 0 { |
| 167 | return 76 |
| 168 | } else if x[1]&(1<<13) != 0 { |
| 169 | return 77 |
| 170 | } else if x[1]&(1<<14) != 0 { |
| 171 | return 78 |
| 172 | } else if x[1]&(1<<15) != 0 { |
| 173 | return 79 |
| 174 | } else if x[1]&(1<<16) != 0 { |
| 175 | return 80 |
| 176 | } else if x[1]&(1<<17) != 0 { |
| 177 | return 81 |
| 178 | } else if x[1]&(1<<18) != 0 { |
| 179 | return 82 |
| 180 | } else if x[1]&(1<<19) != 0 { |
| 181 | return 83 |
| 182 | } else if x[1]&(1<<20) != 0 { |
| 183 | return 84 |
| 184 | } else if x[1]&(1<<21) != 0 { |
| 185 | return 85 |
| 186 | } else if x[1]&(1<<22) != 0 { |
| 187 | return 86 |
| 188 | } else if x[1]&(1<<23) != 0 { |
| 189 | return 87 |
| 190 | } else if x[1]&(1<<24) != 0 { |
| 191 | return 88 |
| 192 | } else if x[1]&(1<<25) != 0 { |
| 193 | return 89 |
| 194 | } else if x[1]&(1<<26) != 0 { |
| 195 | return 90 |
| 196 | } else if x[1]&(1<<27) != 0 { |
| 197 | return 91 |
| 198 | } else if x[1]&(1<<28) != 0 { |
| 199 | return 92 |
| 200 | } else if x[1]&(1<<29) != 0 { |
| 201 | return 93 |
| 202 | } else if x[1]&(1<<30) != 0 { |
| 203 | return 94 |
| 204 | } else if x[1]&(1<<31) != 0 { |
| 205 | return 95 |
| 206 | } else if x[1]&(1<<32) != 0 { |
| 207 | return 96 |
| 208 | } else if x[1]&(1<<33) != 0 { |
| 209 | return 97 |
| 210 | } else if x[1]&(1<<34) != 0 { |
| 211 | return 98 |
| 212 | } else if x[1]&(1<<35) != 0 { |
| 213 | return 99 |
| 214 | } else if x[1]&(1<<36) != 0 { |
| 215 | return 100 |
| 216 | } else if x[1]&(1<<37) != 0 { |
| 217 | return 101 |
| 218 | } else if x[1]&(1<<38) != 0 { |
| 219 | return 102 |
| 220 | } else if x[1]&(1<<39) != 0 { |
| 221 | return 103 |
| 222 | } else if x[1]&(1<<40) != 0 { |
| 223 | return 104 |
| 224 | } else if x[1]&(1<<41) != 0 { |
| 225 | return 105 |
| 226 | } else if x[1]&(1<<42) != 0 { |
| 227 | return 106 |
| 228 | } else if x[1]&(1<<43) != 0 { |
| 229 | return 107 |
| 230 | } else if x[1]&(1<<44) != 0 { |
| 231 | return 108 |
| 232 | } else if x[1]&(1<<45) != 0 { |
| 233 | return 109 |
| 234 | } else if x[1]&(1<<46) != 0 { |
| 235 | return 110 |
| 236 | } else if x[1]&(1<<47) != 0 { |
| 237 | return 111 |
| 238 | } else if x[1]&(1<<48) != 0 { |
| 239 | return 112 |
| 240 | } else if x[1]&(1<<49) != 0 { |
| 241 | return 113 |
| 242 | } else if x[1]&(1<<50) != 0 { |
| 243 | return 114 |
| 244 | } else if x[1]&(1<<51) != 0 { |
| 245 | return 115 |
| 246 | } else if x[1]&(1<<52) != 0 { |
| 247 | return 116 |
| 248 | } else if x[1]&(1<<53) != 0 { |
| 249 | return 117 |
| 250 | } else if x[1]&(1<<54) != 0 { |
| 251 | return 118 |
| 252 | } else if x[1]&(1<<55) != 0 { |
| 253 | return 119 |
| 254 | } else if x[1]&(1<<56) != 0 { |
| 255 | return 120 |
| 256 | } else if x[1]&(1<<57) != 0 { |
| 257 | return 121 |
| 258 | } else if x[1]&(1<<58) != 0 { |
| 259 | return 122 |
| 260 | } else if x[1]&(1<<59) != 0 { |
| 261 | return 123 |
| 262 | } else if x[1]&(1<<60) != 0 { |
| 263 | return 124 |
| 264 | } else if x[1]&(1<<61) != 0 { |
| 265 | return 125 |
| 266 | } else if x[1]&(1<<62) != 0 { |
| 267 | return 126 |
| 268 | } else if x[1]&(1<<63) != 0 { |
| 269 | return 127 |
| 270 | } else if x[2]&(1<<0) != 0 { |
| 271 | return 128 |
| 272 | } else if x[2]&(1<<1) != 0 { |
| 273 | return 129 |
| 274 | } else if x[2]&(1<<2) != 0 { |
| 275 | return 130 |
| 276 | } else if x[2]&(1<<3) != 0 { |
| 277 | return 131 |
| 278 | } else if x[2]&(1<<4) != 0 { |
| 279 | return 132 |
| 280 | } else if x[2]&(1<<5) != 0 { |
| 281 | return 133 |
| 282 | } else if x[2]&(1<<6) != 0 { |
| 283 | return 134 |
| 284 | } else if x[2]&(1<<7) != 0 { |
| 285 | return 135 |
| 286 | } else if x[2]&(1<<8) != 0 { |
| 287 | return 136 |
| 288 | } else if x[2]&(1<<9) != 0 { |
| 289 | return 137 |
| 290 | } else if x[2]&(1<<10) != 0 { |
| 291 | return 138 |
| 292 | } else if x[2]&(1<<11) != 0 { |
| 293 | return 139 |
| 294 | } else if x[2]&(1<<12) != 0 { |
| 295 | return 140 |
| 296 | } else if x[2]&(1<<13) != 0 { |
| 297 | return 141 |
| 298 | } else if x[2]&(1<<14) != 0 { |
| 299 | return 142 |
| 300 | } else if x[2]&(1<<15) != 0 { |
| 301 | return 143 |
| 302 | } else if x[2]&(1<<16) != 0 { |
| 303 | return 144 |
| 304 | } else if x[2]&(1<<17) != 0 { |
| 305 | return 145 |
| 306 | } else if x[2]&(1<<18) != 0 { |
| 307 | return 146 |
| 308 | } else if x[2]&(1<<19) != 0 { |
| 309 | return 147 |
| 310 | } else if x[2]&(1<<20) != 0 { |
| 311 | return 148 |
| 312 | } else if x[2]&(1<<21) != 0 { |
| 313 | return 149 |
| 314 | } else if x[2]&(1<<22) != 0 { |
| 315 | return 150 |
| 316 | } else if x[2]&(1<<23) != 0 { |
| 317 | return 151 |
| 318 | } else if x[2]&(1<<24) != 0 { |
| 319 | return 152 |
| 320 | } else if x[2]&(1<<25) != 0 { |
| 321 | return 153 |
| 322 | } else if x[2]&(1<<26) != 0 { |
| 323 | return 154 |
| 324 | } else if x[2]&(1<<27) != 0 { |
| 325 | return 155 |
| 326 | } else if x[2]&(1<<28) != 0 { |
| 327 | return 156 |
| 328 | } else if x[2]&(1<<29) != 0 { |
| 329 | return 157 |
| 330 | } else if x[2]&(1<<30) != 0 { |
| 331 | return 158 |
| 332 | } else if x[2]&(1<<31) != 0 { |
| 333 | return 159 |
| 334 | } else if x[2]&(1<<32) != 0 { |
| 335 | return 160 |
| 336 | } else if x[2]&(1<<33) != 0 { |
| 337 | return 161 |
| 338 | } else if x[2]&(1<<34) != 0 { |
| 339 | return 162 |
| 340 | } else if x[2]&(1<<35) != 0 { |
| 341 | return 163 |
| 342 | } else if x[2]&(1<<36) != 0 { |
| 343 | return 164 |
| 344 | } else if x[2]&(1<<37) != 0 { |
| 345 | return 165 |
| 346 | } else if x[2]&(1<<38) != 0 { |
| 347 | return 166 |
| 348 | } else if x[2]&(1<<39) != 0 { |
| 349 | return 167 |
| 350 | } else if x[2]&(1<<40) != 0 { |
| 351 | return 168 |
| 352 | } else if x[2]&(1<<41) != 0 { |
| 353 | return 169 |
| 354 | } else if x[2]&(1<<42) != 0 { |
| 355 | return 170 |
| 356 | } else if x[2]&(1<<43) != 0 { |
| 357 | return 171 |
| 358 | } else if x[2]&(1<<44) != 0 { |
| 359 | return 172 |
| 360 | } else if x[2]&(1<<45) != 0 { |
| 361 | return 173 |
| 362 | } else if x[2]&(1<<46) != 0 { |
| 363 | return 174 |
| 364 | } else if x[2]&(1<<47) != 0 { |
| 365 | return 175 |
| 366 | } else if x[2]&(1<<48) != 0 { |
| 367 | return 176 |
| 368 | } else if x[2]&(1<<49) != 0 { |
| 369 | return 177 |
| 370 | } else if x[2]&(1<<50) != 0 { |
| 371 | return 178 |
| 372 | } else if x[2]&(1<<51) != 0 { |
| 373 | return 179 |
| 374 | } else if x[2]&(1<<52) != 0 { |
| 375 | return 180 |
| 376 | } else if x[2]&(1<<53) != 0 { |
| 377 | return 181 |
| 378 | } else if x[2]&(1<<54) != 0 { |
| 379 | return 182 |
| 380 | } else if x[2]&(1<<55) != 0 { |
| 381 | return 183 |
| 382 | } else if x[2]&(1<<56) != 0 { |
| 383 | return 184 |
| 384 | } else if x[2]&(1<<57) != 0 { |
| 385 | return 185 |
| 386 | } else if x[2]&(1<<58) != 0 { |
| 387 | return 186 |
| 388 | } else if x[2]&(1<<59) != 0 { |
| 389 | return 187 |
| 390 | } else if x[2]&(1<<60) != 0 { |
| 391 | return 188 |
| 392 | } else if x[2]&(1<<61) != 0 { |
| 393 | return 189 |
| 394 | } else if x[2]&(1<<62) != 0 { |
| 395 | return 190 |
| 396 | } else if x[2]&(1<<63) != 0 { |
| 397 | return 191 |
| 398 | } else if x[3]&(1<<0) != 0 { |
| 399 | return 192 |
| 400 | } else if x[3]&(1<<1) != 0 { |
| 401 | return 193 |
| 402 | } else if x[3]&(1<<2) != 0 { |
| 403 | return 194 |
| 404 | } else if x[3]&(1<<3) != 0 { |
| 405 | return 195 |
| 406 | } else if x[3]&(1<<4) != 0 { |
| 407 | return 196 |
| 408 | } else if x[3]&(1<<5) != 0 { |
| 409 | return 197 |
| 410 | } else if x[3]&(1<<6) != 0 { |
| 411 | return 198 |
| 412 | } else if x[3]&(1<<7) != 0 { |
| 413 | return 199 |
| 414 | } else if x[3]&(1<<8) != 0 { |
| 415 | return 200 |
| 416 | } else if x[3]&(1<<9) != 0 { |
| 417 | return 201 |
| 418 | } else if x[3]&(1<<10) != 0 { |
| 419 | return 202 |
| 420 | } else if x[3]&(1<<11) != 0 { |
| 421 | return 203 |
| 422 | } else if x[3]&(1<<12) != 0 { |
| 423 | return 204 |
| 424 | } else if x[3]&(1<<13) != 0 { |
| 425 | return 205 |
| 426 | } else if x[3]&(1<<14) != 0 { |
| 427 | return 206 |
| 428 | } else if x[3]&(1<<15) != 0 { |
| 429 | return 207 |
| 430 | } else if x[3]&(1<<16) != 0 { |
| 431 | return 208 |
| 432 | } else if x[3]&(1<<17) != 0 { |
| 433 | return 209 |
| 434 | } else if x[3]&(1<<18) != 0 { |
| 435 | return 210 |
| 436 | } else if x[3]&(1<<19) != 0 { |
| 437 | return 211 |
| 438 | } else if x[3]&(1<<20) != 0 { |
| 439 | return 212 |
| 440 | } else if x[3]&(1<<21) != 0 { |
| 441 | return 213 |
| 442 | } else if x[3]&(1<<22) != 0 { |
| 443 | return 214 |
| 444 | } else if x[3]&(1<<23) != 0 { |
| 445 | return 215 |
| 446 | } else if x[3]&(1<<24) != 0 { |
| 447 | return 216 |
| 448 | } else if x[3]&(1<<25) != 0 { |
| 449 | return 217 |
| 450 | } else if x[3]&(1<<26) != 0 { |
| 451 | return 218 |
| 452 | } else if x[3]&(1<<27) != 0 { |
| 453 | return 219 |
| 454 | } else if x[3]&(1<<28) != 0 { |
| 455 | return 220 |
| 456 | } else if x[3]&(1<<29) != 0 { |
| 457 | return 221 |
| 458 | } else if x[3]&(1<<30) != 0 { |
| 459 | return 222 |
| 460 | } else if x[3]&(1<<31) != 0 { |
| 461 | return 223 |
| 462 | } else if x[3]&(1<<32) != 0 { |
| 463 | return 224 |
| 464 | } else if x[3]&(1<<33) != 0 { |
| 465 | return 225 |
| 466 | } else if x[3]&(1<<34) != 0 { |
| 467 | return 226 |
| 468 | } else if x[3]&(1<<35) != 0 { |
| 469 | return 227 |
| 470 | } else if x[3]&(1<<36) != 0 { |
| 471 | return 228 |
| 472 | } else if x[3]&(1<<37) != 0 { |
| 473 | return 229 |
| 474 | } else if x[3]&(1<<38) != 0 { |
| 475 | return 230 |
| 476 | } else if x[3]&(1<<39) != 0 { |
| 477 | return 231 |
| 478 | } else if x[3]&(1<<40) != 0 { |
| 479 | return 232 |
| 480 | } else if x[3]&(1<<41) != 0 { |
| 481 | return 233 |
| 482 | } else if x[3]&(1<<42) != 0 { |
| 483 | return 234 |
| 484 | } else if x[3]&(1<<43) != 0 { |
| 485 | return 235 |
| 486 | } else if x[3]&(1<<44) != 0 { |
| 487 | return 236 |
| 488 | } else if x[3]&(1<<45) != 0 { |
| 489 | return 237 |
| 490 | } else if x[3]&(1<<46) != 0 { |
| 491 | return 238 |
| 492 | } else if x[3]&(1<<47) != 0 { |
| 493 | return 239 |
| 494 | } else if x[3]&(1<<48) != 0 { |
| 495 | return 240 |
| 496 | } else if x[3]&(1<<49) != 0 { |
| 497 | return 241 |
| 498 | } else if x[3]&(1<<50) != 0 { |
| 499 | return 242 |
| 500 | } else if x[3]&(1<<51) != 0 { |
| 501 | return 243 |
| 502 | } else if x[3]&(1<<52) != 0 { |
| 503 | return 244 |
| 504 | } else if x[3]&(1<<53) != 0 { |
| 505 | return 245 |
| 506 | } else if x[3]&(1<<54) != 0 { |
| 507 | return 246 |
| 508 | } else if x[3]&(1<<55) != 0 { |
| 509 | return 247 |
| 510 | } else if x[3]&(1<<56) != 0 { |
| 511 | return 248 |
| 512 | } else if x[3]&(1<<57) != 0 { |
| 513 | return 249 |
| 514 | } else if x[3]&(1<<58) != 0 { |
| 515 | return 250 |
| 516 | } else if x[3]&(1<<59) != 0 { |
| 517 | return 251 |
| 518 | } else if x[3]&(1<<60) != 0 { |
| 519 | return 252 |
| 520 | } else if x[3]&(1<<61) != 0 { |
| 521 | return 253 |
| 522 | } else if x[3]&(1<<62) != 0 { |
| 523 | return 254 |
| 524 | } else if x[3]&(1<<63) != 0 { |
| 525 | return 255 |
| 526 | } |
| 527 | return -1 |
| 528 | } |
| 529 | |
| 530 | func main() { |
| 531 | const ones = ^uint64(0) |
| 532 | for i := 0; i < 256; i++ { |
| 533 | bits := [4]uint64{ones, ones, ones, ones} |
| 534 | |
| 535 | // clear bottom i bits |
| 536 | bits[i/64] ^= 1<<(uint(i)&63) - 1 |
| 537 | for j := i/64 - 1; j >= 0; j-- { |
| 538 | bits[j] = 0 |
| 539 | } |
| 540 | |
| 541 | k := test(bits) |
| 542 | if k != i { |
| 543 | print("test(bits)=", k, " want ", i, "\n") |
| 544 | panic("failed") |
| 545 | } |
| 546 | } |
| 547 | } |
