1 # RUN: llvm-mc -filetype=obj -arch mipsel %s | llvm-readobj -r | FileCheck %s 2 3 # Test the order of records in the relocation table. 4 # 5 # MIPS has a few relocations that have an AHL component in the expression used 6 # to evaluate them. This AHL component is an addend with the same number of 7 # bits as a symbol value but not all of our ABI's are able to supply a 8 # sufficiently sized addend in a single relocation. 9 # 10 # The O32 ABI for example, uses REL relocations which store the addend in the 11 # section data. All the relocations with AHL components affect 16-bit fields 12 # so the addend is limited to 16-bit. This ABI resolves the limitation by 13 # linking relocations (e.g. R_MIPS_HI16 and R_MIPS_LO16) and distributing the 14 # addend between the linked relocations. The ABI mandates that such relocations 15 # must be next to each other in a particular order (e.g. R_MIPS_HI16 must be 16 # followed by a matching R_MIPS_LO16) but the rule is less strict in practice. 17 # 18 # See MipsELFObjectWriter.cpp for a full description of the rules. 19 # 20 # TODO: Add mips16 and micromips tests. 21 22 # HILO 1: HI/LO already match 23 .section .mips_hilo_1, "ax", @progbits 24 lui $2, %hi(sym1) 25 addiu $2, $2, %lo(sym1) 26 27 # CHECK-LABEL: Section ({{[0-9]+}}) .rel.mips_hilo_1 { 28 # CHECK-NEXT: 0x0 R_MIPS_HI16 sym1 29 # CHECK-NEXT: 0x4 R_MIPS_LO16 sym1 30 # CHECK-NEXT: } 31 32 # HILO 2: R_MIPS_HI16 must be followed by a matching R_MIPS_LO16. 33 .section .mips_hilo_2, "ax", @progbits 34 addiu $2, $2, %lo(sym1) 35 lui $2, %hi(sym1) 36 37 # CHECK-LABEL: Section ({{[0-9]+}}) .rel.mips_hilo_2 { 38 # CHECK-NEXT: 0x4 R_MIPS_HI16 sym1 39 # CHECK-NEXT: 0x0 R_MIPS_LO16 sym1 40 # CHECK-NEXT: } 41 42 # HILO 3: R_MIPS_HI16 must be followed by a matching R_MIPS_LO16. 43 # The second relocation matches if the symbol is the same. 44 .section .mips_hilo_3, "ax", @progbits 45 addiu $2, $2, %lo(sym1) 46 lui $2, %hi(sym2) 47 addiu $2, $2, %lo(sym2) 48 lui $2, %hi(sym1) 49 50 # CHECK-LABEL: Section ({{[0-9]+}}) .rel.mips_hilo_3 { 51 # CHECK-NEXT: 0xC R_MIPS_HI16 sym1 52 # CHECK-NEXT: 0x0 R_MIPS_LO16 sym1 53 # CHECK-NEXT: 0x4 R_MIPS_HI16 sym2 54 # CHECK-NEXT: 0x8 R_MIPS_LO16 sym2 55 # CHECK-NEXT: } 56 57 # HILO 3b: Same as 3 but a different starting order. 58 .section .mips_hilo_3b, "ax", @progbits 59 addiu $2, $2, %lo(sym1) 60 lui $2, %hi(sym1) 61 addiu $2, $2, %lo(sym2) 62 lui $2, %hi(sym2) 63 64 # CHECK-LABEL: Section ({{[0-9]+}}) .rel.mips_hilo_3b { 65 # CHECK-NEXT: 0x4 R_MIPS_HI16 sym1 66 # CHECK-NEXT: 0x0 R_MIPS_LO16 sym1 67 # CHECK-NEXT: 0xC R_MIPS_HI16 sym2 68 # CHECK-NEXT: 0x8 R_MIPS_LO16 sym2 69 # CHECK-NEXT: } 70 71 # HILO 4: R_MIPS_HI16 must be followed by a matching R_MIPS_LO16. 72 # The second relocation matches if the symbol is the same and the 73 # offset is the same. 74 .section .mips_hilo_4, "ax", @progbits 75 addiu $2, $2, %lo(sym1) 76 addiu $2, $2, %lo(sym1+4) 77 lui $2, %hi(sym1+4) 78 lui $2, %hi(sym1) 79 80 # CHECK-LABEL: Section ({{[0-9]+}}) .rel.mips_hilo_4 { 81 # CHECK-NEXT: 0xC R_MIPS_HI16 sym1 82 # CHECK-NEXT: 0x0 R_MIPS_LO16 sym1 83 # CHECK-NEXT: 0x8 R_MIPS_HI16 sym1 84 # CHECK-NEXT: 0x4 R_MIPS_LO16 sym1 85 # CHECK-NEXT: } 86 87 # HILO 5: R_MIPS_HI16 must be followed by a matching R_MIPS_LO16. 88 # The second relocation matches if the symbol is the same and the 89 # offset is greater or equal. Exact matches are preferred so both 90 # R_MIPS_HI16's match the same R_MIPS_LO16. 91 .section .mips_hilo_5, "ax", @progbits 92 lui $2, %hi(sym1) 93 lui $2, %hi(sym1) 94 addiu $2, $2, %lo(sym1+1) 95 addiu $2, $2, %lo(sym1) 96 97 # CHECK-LABEL: Section ({{[0-9]+}}) .rel.mips_hilo_5 { 98 # CHECK-NEXT: 0x8 R_MIPS_LO16 sym1 99 # CHECK-NEXT: 0x0 R_MIPS_HI16 sym1 100 # CHECK-NEXT: 0x4 R_MIPS_HI16 sym1 101 # CHECK-NEXT: 0xC R_MIPS_LO16 sym1 102 # CHECK-NEXT: } 103 104 # HILO 6: R_MIPS_HI16 must be followed by a matching R_MIPS_LO16. 105 # The second relocation matches if the symbol is the same and the 106 # offset is greater or equal. Smaller offsets are preferred so both 107 # R_MIPS_HI16's still match the same R_MIPS_LO16. 108 .section .mips_hilo_6, "ax", @progbits 109 lui $2, %hi(sym1) 110 lui $2, %hi(sym1) 111 addiu $2, $2, %lo(sym1+2) 112 addiu $2, $2, %lo(sym1+1) 113 114 # CHECK-LABEL: Section ({{[0-9]+}}) .rel.mips_hilo_6 { 115 # CHECK-NEXT: 0x8 R_MIPS_LO16 sym1 116 # CHECK-NEXT: 0x0 R_MIPS_HI16 sym1 117 # CHECK-NEXT: 0x4 R_MIPS_HI16 sym1 118 # CHECK-NEXT: 0xC R_MIPS_LO16 sym1 119 # CHECK-NEXT: } 120 121 # HILO 7: R_MIPS_HI16 must be followed by a matching R_MIPS_LO16. 122 # The second relocation matches if the symbol is the same and the 123 # offset is greater or equal so that the carry bit is correct. The two 124 # R_MIPS_HI16's therefore match different R_MIPS_LO16's. 125 .section .mips_hilo_7, "ax", @progbits 126 addiu $2, $2, %lo(sym1+1) 127 addiu $2, $2, %lo(sym1+6) 128 lui $2, %hi(sym1+4) 129 lui $2, %hi(sym1) 130 131 # CHECK-LABEL: Section ({{[0-9]+}}) .rel.mips_hilo_7 { 132 # CHECK-NEXT: 0xC R_MIPS_HI16 sym1 133 # CHECK-NEXT: 0x0 R_MIPS_LO16 sym1 134 # CHECK-NEXT: 0x8 R_MIPS_HI16 sym1 135 # CHECK-NEXT: 0x4 R_MIPS_LO16 sym1 136 # CHECK-NEXT: } 137 138 # HILO 8: R_MIPS_LO16's may be orphaned. 139 .section .mips_hilo_8, "ax", @progbits 140 lw $2, %lo(sym1) 141 142 # CHECK-LABEL: Section ({{[0-9]+}}) .rel.mips_hilo_8 { 143 # CHECK-NEXT: 0x0 R_MIPS_LO16 sym1 144 # CHECK-NEXT: } 145 146 # HILO 8b: Another example of 8. The R_MIPS_LO16 at 0x4 is orphaned. 147 .section .mips_hilo_8b, "ax", @progbits 148 lw $2, %lo(sym1) 149 lw $2, %lo(sym1) 150 lui $2, %hi(sym1) 151 152 # CHECK-LABEL: Section ({{[0-9]+}}) .rel.mips_hilo_8b { 153 # CHECK-NEXT: 0x8 R_MIPS_HI16 sym1 154 # CHECK-NEXT: 0x0 R_MIPS_LO16 sym1 155 # CHECK-NEXT: 0x4 R_MIPS_LO16 sym1 156 # CHECK-NEXT: } 157 158 # HILO 9: R_MIPS_HI16's don't need a matching R_MIPS_LO16 to immediately follow 159 # so long as there is one after the R_MIPS_HI16 somewhere. This isn't 160 # permitted by the ABI specification but has been allowed in practice 161 # for a very long time. The R_MIPS_HI16's should be ordered by the 162 # address they affect for purely cosmetic reasons. 163 .section .mips_hilo_9, "ax", @progbits 164 lw $2, %lo(sym1) 165 lui $2, %hi(sym1) 166 lui $2, %hi(sym1) 167 168 # CHECK-LABEL: Section ({{[0-9]+}}) .rel.mips_hilo_9 { 169 # CHECK-NEXT: 0x4 R_MIPS_HI16 sym1 170 # CHECK-NEXT: 0x8 R_MIPS_HI16 sym1 171 # CHECK-NEXT: 0x0 R_MIPS_LO16 sym1 172 # CHECK-NEXT: } 173 174 # HILO 10: R_MIPS_HI16's must have a matching R_MIPS_LO16 somewhere though. 175 # When this is impossible we have two possible bad behaviours 176 # depending on the linker implementation: 177 # * The linker silently computes the wrong value using a partially 178 # matching R_MIPS_LO16. 179 # * The linker rejects the relocation table as invalid. 180 # The latter is preferable since it's far easier to detect and debug so 181 # check that we encourage this behaviour by putting invalid 182 # R_MIPS_HI16's at the end of the relocation table where the risk of a 183 # partial match is very low. 184 .section .mips_hilo_10, "ax", @progbits 185 lui $2, %hi(sym1) 186 lw $2, %lo(sym1) 187 lui $2, %hi(sym2) 188 lui $2, %hi(sym3) 189 lw $2, %lo(sym3) 190 191 # CHECK-LABEL: Section ({{[0-9]+}}) .rel.mips_hilo_10 { 192 # CHECK-NEXT: 0x0 R_MIPS_HI16 sym1 193 # CHECK-NEXT: 0x4 R_MIPS_LO16 sym1 194 # CHECK-NEXT: 0xC R_MIPS_HI16 sym3 195 # CHECK-NEXT: 0x10 R_MIPS_LO16 sym3 196 # CHECK-NEXT: 0x8 R_MIPS_HI16 sym2 197 # CHECK-NEXT: } 198 199 # Now do the same tests for GOT/LO. 200 # The rules only apply to R_MIPS_GOT16 on local symbols which are also 201 # rewritten into section relative relocations. 202 203 # GOTLO 1: GOT/LO already match 204 .section .mips_gotlo_1, "ax", @progbits 205 lui $2, %got(local1) 206 addiu $2, $2, %lo(local1) 207 208 # CHECK-LABEL: Section ({{[0-9]+}}) .rel.mips_gotlo_1 { 209 # CHECK-NEXT: 0x0 R_MIPS_GOT16 .text 210 # CHECK-NEXT: 0x4 R_MIPS_LO16 .text 211 # CHECK-NEXT: } 212 213 # GOTLO 2: R_MIPS_GOT16 must be followed by a matching R_MIPS_LO16. 214 .section .mips_gotlo_2, "ax", @progbits 215 addiu $2, $2, %lo(local1) 216 lui $2, %got(local1) 217 218 # CHECK-LABEL: Section ({{[0-9]+}}) .rel.mips_gotlo_2 { 219 # CHECK-NEXT: 0x4 R_MIPS_GOT16 .text 220 # CHECK-NEXT: 0x0 R_MIPS_LO16 .text 221 # CHECK-NEXT: } 222 223 # GOTLO 3: R_MIPS_GOT16 must be followed by a matching R_MIPS_LO16. 224 # The second relocation matches if the symbol is the same. 225 .section .mips_gotlo_3, "ax", @progbits 226 addiu $2, $2, %lo(local1) 227 lui $2, %got(local2) 228 addiu $2, $2, %lo(local2) 229 lui $2, %got(local1) 230 231 # CHECK-LABEL: Section ({{[0-9]+}}) .rel.mips_gotlo_3 { 232 # CHECK-NEXT: 0xC R_MIPS_GOT16 .text 233 # CHECK-NEXT: 0x0 R_MIPS_LO16 .text 234 # CHECK-NEXT: 0x4 R_MIPS_GOT16 .text 235 # CHECK-NEXT: 0x8 R_MIPS_LO16 .text 236 # CHECK-NEXT: } 237 238 # GOTLO 3b: Same as 3 but a different starting order. 239 .section .mips_gotlo_3b, "ax", @progbits 240 addiu $2, $2, %lo(local1) 241 lui $2, %got(local1) 242 addiu $2, $2, %lo(local2) 243 lui $2, %got(local2) 244 245 # CHECK-LABEL: Section ({{[0-9]+}}) .rel.mips_gotlo_3b { 246 # CHECK-NEXT: 0x4 R_MIPS_GOT16 .text 247 # CHECK-NEXT: 0x0 R_MIPS_LO16 .text 248 # CHECK-NEXT: 0xC R_MIPS_GOT16 .text 249 # CHECK-NEXT: 0x8 R_MIPS_LO16 .text 250 # CHECK-NEXT: } 251 252 # GOTLO 4: R_MIPS_GOT16 must be followed by a matching R_MIPS_LO16. 253 # The second relocation matches if the symbol is the same and the 254 # offset is the same. 255 .section .mips_gotlo_4, "ax", @progbits 256 addiu $2, $2, %lo(local1) 257 addiu $2, $2, %lo(local1+4) 258 lui $2, %got(local1+4) 259 lui $2, %got(local1) 260 261 # CHECK-LABEL: Section ({{[0-9]+}}) .rel.mips_gotlo_4 { 262 # CHECK-NEXT: 0xC R_MIPS_GOT16 .text 263 # CHECK-NEXT: 0x0 R_MIPS_LO16 .text 264 # CHECK-NEXT: 0x8 R_MIPS_GOT16 .text 265 # CHECK-NEXT: 0x4 R_MIPS_LO16 .text 266 # CHECK-NEXT: } 267 268 # GOTLO 5: R_MIPS_GOT16 must be followed by a matching R_MIPS_LO16. 269 # The second relocation matches if the symbol is the same and the 270 # offset is greater or equal. Exact matches are preferred so both 271 # R_MIPS_GOT16's match the same R_MIPS_LO16. 272 .section .mips_gotlo_5, "ax", @progbits 273 lui $2, %got(local1) 274 lui $2, %got(local1) 275 addiu $2, $2, %lo(local1+1) 276 addiu $2, $2, %lo(local1) 277 278 # CHECK-LABEL: Section ({{[0-9]+}}) .rel.mips_gotlo_5 { 279 # CHECK-NEXT: 0x8 R_MIPS_LO16 .text 280 # CHECK-NEXT: 0x0 R_MIPS_GOT16 .text 281 # CHECK-NEXT: 0x4 R_MIPS_GOT16 .text 282 # CHECK-NEXT: 0xC R_MIPS_LO16 .text 283 # CHECK-NEXT: } 284 285 # GOTLO 6: R_MIPS_GOT16 must be followed by a matching R_MIPS_LO16. 286 # The second relocation matches if the symbol is the same and the 287 # offset is greater or equal. Smaller offsets are preferred so both 288 # R_MIPS_GOT16's still match the same R_MIPS_LO16. 289 .section .mips_gotlo_6, "ax", @progbits 290 lui $2, %got(local1) 291 lui $2, %got(local1) 292 addiu $2, $2, %lo(local1+2) 293 addiu $2, $2, %lo(local1+1) 294 295 # CHECK-LABEL: Section ({{[0-9]+}}) .rel.mips_gotlo_6 { 296 # CHECK-NEXT: 0x8 R_MIPS_LO16 .text 297 # CHECK-NEXT: 0x0 R_MIPS_GOT16 .text 298 # CHECK-NEXT: 0x4 R_MIPS_GOT16 .text 299 # CHECK-NEXT: 0xC R_MIPS_LO16 .text 300 # CHECK-NEXT: } 301 302 # GOTLO 7: R_MIPS_GOT16 must be followed by a matching R_MIPS_LO16. 303 # The second relocation matches if the symbol is the same and the 304 # offset is greater or equal so that the carry bit is correct. The two 305 # R_MIPS_GOT16's therefore match different R_MIPS_LO16's. 306 .section .mips_gotlo_7, "ax", @progbits 307 addiu $2, $2, %lo(local1+1) 308 addiu $2, $2, %lo(local1+6) 309 lui $2, %got(local1+4) 310 lui $2, %got(local1) 311 312 # CHECK-LABEL: Section ({{[0-9]+}}) .rel.mips_gotlo_7 { 313 # CHECK-NEXT: 0xC R_MIPS_GOT16 .text 314 # CHECK-NEXT: 0x0 R_MIPS_LO16 .text 315 # CHECK-NEXT: 0x8 R_MIPS_GOT16 .text 316 # CHECK-NEXT: 0x4 R_MIPS_LO16 .text 317 # CHECK-NEXT: } 318 319 # GOTLO 8: R_MIPS_LO16's may be orphaned. 320 .section .mips_gotlo_8, "ax", @progbits 321 lw $2, %lo(local1) 322 323 # CHECK-LABEL: Section ({{[0-9]+}}) .rel.mips_gotlo_8 { 324 # CHECK-NEXT: 0x0 R_MIPS_LO16 .text 325 # CHECK-NEXT: } 326 327 # GOTLO 8b: Another example of 8. The R_MIPS_LO16 at 0x4 is orphaned. 328 .section .mips_gotlo_8b, "ax", @progbits 329 lw $2, %lo(local1) 330 lw $2, %lo(local1) 331 lui $2, %got(local1) 332 333 # CHECK-LABEL: Section ({{[0-9]+}}) .rel.mips_gotlo_8b { 334 # CHECK-NEXT: 0x8 R_MIPS_GOT16 .text 335 # CHECK-NEXT: 0x0 R_MIPS_LO16 .text 336 # CHECK-NEXT: 0x4 R_MIPS_LO16 .text 337 # CHECK-NEXT: } 338 339 # GOTLO 9: R_MIPS_GOT16's don't need a matching R_MIPS_LO16 to immediately 340 # follow so long as there is one after the R_MIPS_GOT16 somewhere. 341 # This isn't permitted by the ABI specification but has been allowed 342 # in practice for a very long time. The R_MIPS_GOT16's should be 343 # ordered by the address they affect for purely cosmetic reasons. 344 .section .mips_gotlo_9, "ax", @progbits 345 lw $2, %lo(local1) 346 lui $2, %got(local1) 347 lui $2, %got(local1) 348 349 # CHECK-LABEL: Section ({{[0-9]+}}) .rel.mips_gotlo_9 { 350 # CHECK-NEXT: 0x4 R_MIPS_GOT16 .text 351 # CHECK-NEXT: 0x8 R_MIPS_GOT16 .text 352 # CHECK-NEXT: 0x0 R_MIPS_LO16 .text 353 # CHECK-NEXT: } 354 355 # GOTLO 10: R_MIPS_GOT16's must have a matching R_MIPS_LO16 somewhere though. 356 # When this is impossible we have two possible bad behaviours 357 # depending on the linker implementation: 358 # * The linker silently computes the wrong value using a partially 359 # matching R_MIPS_LO16. 360 # * The linker rejects the relocation table as invalid. 361 # The latter is preferable since it's far easier to detect and debug 362 # so check that we encourage this behaviour by putting invalid 363 # R_MIPS_GOT16's at the end of the relocation table where the risk of 364 # a partial match is very low. 365 .section .mips_gotlo_10, "ax", @progbits 366 lui $2, %got(local1) 367 lw $2, %lo(local1) 368 lui $2, %got(local2) 369 lui $2, %got(local3) 370 lw $2, %lo(local3) 371 372 # CHECK-LABEL: Section ({{[0-9]+}}) .rel.mips_gotlo_10 { 373 # CHECK-NEXT: 0x0 R_MIPS_GOT16 .text 374 # CHECK-NEXT: 0x4 R_MIPS_LO16 .text 375 # CHECK-NEXT: 0xC R_MIPS_GOT16 .text 376 # CHECK-NEXT: 0x10 R_MIPS_LO16 .text 377 # CHECK-NEXT: 0x8 R_MIPS_GOT16 .text 378 # CHECK-NEXT: } 379 380 # Finally, do test 2 for R_MIPS_GOT16 on external symbols to prove they are 381 # exempt from the rules for local symbols. 382 383 # External GOTLO 2: R_MIPS_GOT16 must be followed by a matching R_MIPS_LO16. 384 .section .mips_ext_gotlo_2, "ax", @progbits 385 addiu $2, $2, %lo(sym1) 386 lui $2, %got(sym1) 387 388 # CHECK-LABEL: Section ({{[0-9]+}}) .rel.mips_ext_gotlo_2 { 389 # CHECK-NEXT: 0x0 R_MIPS_LO16 sym1 390 # CHECK-NEXT: 0x4 R_MIPS_GOT16 sym1 391 # CHECK-NEXT: } 392 393 # Define some local symbols. 394 .text 395 nop 396 local1: nop 397 local2: nop 398 local3: nop 399
