test/MC/ARM/basic-thumb-instructions.s

   1 @ RUN: llvm-mc -triple=thumbv6-apple-darwin -show-encoding < %s | FileCheck %s
   2   .syntax unified
   3   .globl _func
   4
   5 @ Check that the assembler can handle the documented syntax from the ARM ARM.
   6 @ For complex constructs like shifter operands, check more thoroughly for them
   7 @ once then spot check that following instructions accept the form generally.
   8 @ This gives us good coverage while keeping the overall size of the test
   9 @ more reasonable.
  10
  11
  12 @ FIXME: Some 3-operand instructions have a 2-operand assembly syntax.
  13
  14 _func:
  15 @ CHECK: _func
  16
  17 @------------------------------------------------------------------------------
  18 @ ADC (register)
  19 @------------------------------------------------------------------------------
  20         adcs r4, r6
  21
  22 @ CHECK: adcs   r4, r6                  @ encoding: [0x74,0x41]
  23
  24
  25 @------------------------------------------------------------------------------
  26 @ ADD (immediate)
  27 @------------------------------------------------------------------------------
  28         adds r1, r2, #3
  29 @ When Rd is not explicitly specified, encoding T2 is preferred even though
  30 @ the literal is in the range [0,7] which would allow encoding T1.
  31         adds r2, #3
  32         adds r2, #8
  33
  34 @ CHECK: adds   r1, r2, #3              @ encoding: [0xd1,0x1c]
  35 @ CHECK: adds   r2, #3                  @ encoding: [0x03,0x32]
  36 @ CHECK: adds   r2, #8                  @ encoding: [0x08,0x32]
  37
  38
  39 @------------------------------------------------------------------------------
  40 @ ADD (register)
  41 @------------------------------------------------------------------------------
  42         adds r1, r2, r3
  43         add r2, r8
  44
  45 @ CHECK: adds   r1, r2, r3              @ encoding: [0xd1,0x18]
  46 @ CHECK: add    r2, r8                  @ encoding: [0x42,0x44]
  47
  48
  49 @------------------------------------------------------------------------------
  50 @ ADD (SP plus immediate)
  51 @------------------------------------------------------------------------------
  52         add sp, #4
  53         add sp, #508
  54         add sp, sp, #4
  55         add r2, sp, #8
  56         add r2, sp, #1020
  57
  58 @ CHECK: add    sp, #4                  @ encoding: [0x01,0xb0]
  59 @ CHECK: add    sp, #508                @ encoding: [0x7f,0xb0]
  60 @ CHECK: add    sp, #4                  @ encoding: [0x01,0xb0]
  61 @ CHECK: add    r2, sp, #8              @ encoding: [0x02,0xaa]
  62 @ CHECK: add    r2, sp, #1020           @ encoding: [0xff,0xaa]
  63
  64
  65 @------------------------------------------------------------------------------
  66 @ ADD (SP plus register)
  67 @------------------------------------------------------------------------------
  68         add sp, r3
  69         add r2, sp, r2
  70
  71 @ CHECK: add    sp, r3                  @ encoding: [0x9d,0x44]
  72 @ CHECK: add    r2, sp, r2              @ encoding: [0x6a,0x44]
  73
  74
  75 @------------------------------------------------------------------------------
  76 @ ADR
  77 @------------------------------------------------------------------------------
  78         adr r2, _baz
  79         adr     r2, #3
  80
  81 @ CHECK: adr    r2, _baz                @ encoding: [A,0xa2]
  82             @   fixup A - offset: 0, value: _baz, kind: fixup_thumb_adr_pcrel_10
  83 @ CHECK: adr    r2, #3                  @ encoding: [0x03,0xa2]
  84
  85 @------------------------------------------------------------------------------
  86 @ ASR (immediate)
  87 @------------------------------------------------------------------------------
  88         asrs r2, r3, #32
  89         asrs r2, r3, #5
  90         asrs r2, r3, #1
  91
  92 @ CHECK: asrs   r2, r3, #32             @ encoding: [0x1a,0x10]
  93 @ CHECK: asrs   r2, r3, #5              @ encoding: [0x5a,0x11]
  94 @ CHECK: asrs   r2, r3, #1              @ encoding: [0x5a,0x10]
  95
  96
  97 @------------------------------------------------------------------------------
  98 @ ASR (register)
  99 @------------------------------------------------------------------------------
 100         asrs r5, r2
 101
 102 @ CHECK: asrs   r5, r2                  @ encoding: [0x15,0x41]
 103
 104
 105 @------------------------------------------------------------------------------
 106 @ B
 107 @------------------------------------------------------------------------------
 108         b _baz
 109         beq _bar
 110         b       #1838
 111         b       #-420
 112
 113 @ CHECK: b      _baz                    @ encoding: [A,0xe0'A']
 114              @   fixup A - offset: 0, value: _baz, kind: fixup_arm_thumb_br
 115 @ CHECK: beq    _bar                    @ encoding: [A,0xd0]
 116              @   fixup A - offset: 0, value: _bar, kind: fixup_arm_thumb_bcc
 117 @ CHECK: b       #1838                   @ encoding: [0x97,0xe3]
 118 @ CHECK: b       #-420                   @ encoding: [0x2e,0xe7]
 119
 120 @------------------------------------------------------------------------------
 121 @ BL/BLX
 122 @------------------------------------------------------------------------------
 123         blx     #884800
 124         blx     #1769600
 125
 126 @ CHECK: blx     #884800                 @ encoding: [0xd8,0xf0,0x20,0xe8]
 127 @ CHECK: blx     #1769600                @ encoding: [0xb0,0xf1,0x40,0xe8]
 128
 129 @------------------------------------------------------------------------------
 130 @ BICS
 131 @------------------------------------------------------------------------------
 132         bics r1, r6
 133
 134 @ CHECK: bics   r1, r6                  @ encoding: [0xb1,0x43]
 135
 136
 137 @------------------------------------------------------------------------------
 138 @ BKPT
 139 @------------------------------------------------------------------------------
 140         bkpt #0
 141         bkpt #255
 142
 143 @ CHECK: bkpt   #0                      @ encoding: [0x00,0xbe]
 144 @ CHECK: bkpt   #255                    @ encoding: [0xff,0xbe]
 145
 146
 147 @------------------------------------------------------------------------------
 148 @ BL/BLX (immediate)
 149 @------------------------------------------------------------------------------
 150         bl _bar
 151         blx _baz
 152
 153 @ CHECK: bl     _bar                    @ encoding: [A,0xf0'A',A,0xf8'A']
 154              @   fixup A - offset: 0, value: _bar, kind: fixup_arm_thumb_bl
 155 @ CHECK: blx    _baz                    @ encoding: [A,0xf0'A',A,0xe8'A']
 156              @   fixup A - offset: 0, value: _baz, kind: fixup_arm_thumb_blx
 157
 158
 159 @------------------------------------------------------------------------------
 160 @ BLX (register)
 161 @------------------------------------------------------------------------------
 162         blx r4
 163
 164 @ CHECK: blx    r4                      @ encoding: [0xa0,0x47]
 165
 166
 167 @------------------------------------------------------------------------------
 168 @ BX
 169 @------------------------------------------------------------------------------
 170         bx r2
 171
 172 @ CHECK: bx     r2                      @ encoding: [0x10,0x47]
 173
 174
 175 @------------------------------------------------------------------------------
 176 @ CMN
 177 @------------------------------------------------------------------------------
 178
 179         cmn r5, r1
 180
 181 @ CHECK: cmn    r5, r1                  @ encoding: [0xcd,0x42]
 182
 183
 184 @------------------------------------------------------------------------------
 185 @ CMP
 186 @------------------------------------------------------------------------------
 187         cmp r6, #32
 188         cmp r3, r4
 189         cmp r8, r1
 190
 191 @ CHECK: cmp    r6, #32                 @ encoding: [0x20,0x2e]
 192 @ CHECK: cmp    r3, r4                  @ encoding: [0xa3,0x42]
 193 @ CHECK: cmp    r8, r1                  @ encoding: [0x88,0x45]
 194
 195 @------------------------------------------------------------------------------
 196 @ EOR
 197 @------------------------------------------------------------------------------
 198         eors r4, r5
 199
 200 @ CHECK: eors   r4, r5                  @ encoding: [0x6c,0x40]
 201
 202
 203 @------------------------------------------------------------------------------
 204 @ LDM
 205 @------------------------------------------------------------------------------
 206         ldm r3, {r0, r1, r2, r3, r4, r5, r6, r7}
 207         ldm r2!, {r1, r3, r4, r5, r7}
 208         ldm r1, {r1}
 209
 210 @ CHECK: ldm    r3, {r0, r1, r2, r3, r4, r5, r6, r7} @ encoding: [0xff,0xcb]
 211 @ CHECK: ldm    r2!, {r1, r3, r4, r5, r7} @ encoding: [0xba,0xca]
 212 @ CHECK: ldm    r1, {r1}                @ encoding: [0x02,0xc9]
 213
 214
 215 @------------------------------------------------------------------------------
 216 @ LDR (immediate)
 217 @------------------------------------------------------------------------------
 218         ldr r1, [r5]
 219         ldr r2, [r6, #32]
 220         ldr r3, [r7, #124]
 221         ldr r1, [sp]
 222         ldr r2, [sp, #24]
 223         ldr r3, [sp, #1020]
 224
 225
 226 @ CHECK: ldr    r1, [r5]                @ encoding: [0x29,0x68]
 227 @ CHECK: ldr    r2, [r6, #32]           @ encoding: [0x32,0x6a]
 228 @ CHECK: ldr    r3, [r7, #124]          @ encoding: [0xfb,0x6f]
 229 @ CHECK: ldr    r1, [sp]                @ encoding: [0x00,0x99]
 230 @ CHECK: ldr    r2, [sp, #24]           @ encoding: [0x06,0x9a]
 231 @ CHECK: ldr    r3, [sp, #1020]         @ encoding: [0xff,0x9b]
 232
 233
 234 @------------------------------------------------------------------------------
 235 @ LDR (literal)
 236 @------------------------------------------------------------------------------
 237         ldr r1, _foo
 238         ldr     r3, #604
 239         ldr     r3, #368
 240
 241 @ CHECK: ldr    r1, _foo                @ encoding: [A,0x49]
 242              @   fixup A - offset: 0, value: _foo, kind: fixup_arm_thumb_cp
 243 @ CHECK: ldr     r3, #604                @ encoding: [0x97,0x4b]
 244 @ CHECK: ldr     r3, #368                @ encoding: [0x5c,0x4b]
 245
 246 @------------------------------------------------------------------------------
 247 @ LDR (register)
 248 @------------------------------------------------------------------------------
 249         ldr r1, [r2, r3]
 250
 251 @ CHECK: ldr    r1, [r2, r3]            @ encoding: [0xd1,0x58]
 252
 253
 254 @------------------------------------------------------------------------------
 255 @ LDRB (immediate)
 256 @------------------------------------------------------------------------------
 257         ldrb r4, [r3]
 258         ldrb r5, [r6, #0]
 259         ldrb r6, [r7, #31]
 260
 261 @ CHECK: ldrb   r4, [r3]                @ encoding: [0x1c,0x78]
 262 @ CHECK: ldrb   r5, [r6]                @ encoding: [0x35,0x78]
 263 @ CHECK: ldrb   r6, [r7, #31]           @ encoding: [0xfe,0x7f]
 264
 265
 266 @------------------------------------------------------------------------------
 267 @ LDRB (register)
 268 @------------------------------------------------------------------------------
 269         ldrb r6, [r4, r5]
 270
 271 @ CHECK: ldrb   r6, [r4, r5]            @ encoding: [0x66,0x5d]
 272
 273
 274 @------------------------------------------------------------------------------
 275 @ LDRH (immediate)
 276 @------------------------------------------------------------------------------
 277         ldrh r3, [r3]
 278         ldrh r4, [r6, #2]
 279         ldrh r5, [r7, #62]
 280
 281 @ CHECK: ldrh   r3, [r3]                @ encoding: [0x1b,0x88]
 282 @ CHECK: ldrh   r4, [r6, #2]            @ encoding: [0x74,0x88]
 283 @ CHECK: ldrh   r5, [r7, #62]           @ encoding: [0xfd,0x8f]
 284
 285
 286 @------------------------------------------------------------------------------
 287 @ LDRH (register)
 288 @------------------------------------------------------------------------------
 289         ldrh r6, [r2, r6]
 290
 291 @ CHECK: ldrh   r6, [r2, r6]            @ encoding: [0x96,0x5b]
 292
 293
 294 @------------------------------------------------------------------------------
 295 @ LDRSB/LDRSH
 296 @------------------------------------------------------------------------------
 297         ldrsb r6, [r2, r6]
 298         ldrsh r3, [r7, r1]
 299
 300 @ CHECK: ldrsb  r6, [r2, r6]            @ encoding: [0x96,0x57]
 301 @ CHECK: ldrsh  r3, [r7, r1]            @ encoding: [0x7b,0x5e]
 302
 303
 304 @------------------------------------------------------------------------------
 305 @ LSL (immediate)
 306 @------------------------------------------------------------------------------
 307         lsls r4, r5, #0
 308         lsls r4, r5, #4
 309
 310 @ CHECK: lsls   r4, r5, #0              @ encoding: [0x2c,0x00]
 311 @ CHECK: lsls   r4, r5, #4              @ encoding: [0x2c,0x01]
 312
 313
 314 @------------------------------------------------------------------------------
 315 @ LSL (register)
 316 @------------------------------------------------------------------------------
 317         lsls r2, r6
 318
 319 @ CHECK: lsls   r2, r6                  @ encoding: [0xb2,0x40]
 320
 321
 322 @------------------------------------------------------------------------------
 323 @ LSR (immediate)
 324 @------------------------------------------------------------------------------
 325         lsrs r1, r3, #1
 326         lsrs r1, r3, #32
 327
 328 @ CHECK: lsrs   r1, r3, #1              @ encoding: [0x59,0x08]
 329 @ CHECK: lsrs   r1, r3, #32             @ encoding: [0x19,0x08]
 330
 331
 332 @------------------------------------------------------------------------------
 333 @ LSR (register)
 334 @------------------------------------------------------------------------------
 335         lsrs r2, r6
 336
 337 @ CHECK: lsrs   r2, r6                  @ encoding: [0xf2,0x40]
 338
 339
 340 @------------------------------------------------------------------------------
 341 @ MOV (immediate)
 342 @------------------------------------------------------------------------------
 343         movs r2, #0
 344         movs r2, #255
 345         movs r2, #23
 346
 347 @ CHECK: movs   r2, #0                  @ encoding: [0x00,0x22]
 348 @ CHECK: movs   r2, #255                @ encoding: [0xff,0x22]
 349 @ CHECK: movs   r2, #23                 @ encoding: [0x17,0x22]
 350
 351
 352 @------------------------------------------------------------------------------
 353 @ MOV (register)
 354 @------------------------------------------------------------------------------
 355         mov r3, r4
 356         movs r1, r3
 357
 358 @ CHECK: mov    r3, r4                  @ encoding: [0x23,0x46]
 359 @ CHECK: movs   r1, r3                  @ encoding: [0x19,0x00]
 360
 361
 362 @------------------------------------------------------------------------------
 363 @ MUL
 364 @------------------------------------------------------------------------------
 365         muls r1, r2, r1
 366         muls r3, r4
 367
 368 @ CHECK: muls   r1, r2, r1              @ encoding: [0x51,0x43]
 369 @ CHECK: muls   r3, r4, r3              @ encoding: [0x63,0x43]
 370
 371
 372 @------------------------------------------------------------------------------
 373 @ MVN
 374 @------------------------------------------------------------------------------
 375         mvns r6, r3
 376
 377 @ CHECK: mvns   r6, r3                  @ encoding: [0xde,0x43]
 378
 379
 380 @------------------------------------------------------------------------------
 381 @ NEG
 382 @------------------------------------------------------------------------------
 383         negs r3, r4
 384
 385 @ CHECK: rsbs   r3, r4, #0              @ encoding: [0x63,0x42]
 386
 387
 388 @------------------------------------------------------------------------------
 389 @ NOP
 390 @------------------------------------------------------------------------------
 391         nop
 392
 393 @ CHECK: nop                            @ encoding: [0xc0,0x46]
 394
 395
 396 @------------------------------------------------------------------------------
 397 @ ORR
 398 @------------------------------------------------------------------------------
 399         orrs  r3, r4
 400
 401 @ CHECK-ERRORS:         orrs    r3, r4                  @ encoding: [0x23,0x43]
 402
 403
 404 @------------------------------------------------------------------------------
 405 @ POP
 406 @------------------------------------------------------------------------------
 407         pop {r2, r3, r6}
 408
 409 @ CHECK: pop    {r2, r3, r6}            @ encoding: [0x4c,0xbc]
 410
 411
 412 @------------------------------------------------------------------------------
 413 @ PUSH
 414 @------------------------------------------------------------------------------
 415         push {r1, r2, r7}
 416
 417 @ CHECK: push   {r1, r2, r7}            @ encoding: [0x86,0xb4]
 418
 419
 420 @------------------------------------------------------------------------------
 421 @ REV/REV16/REVSH
 422 @------------------------------------------------------------------------------
 423         rev r6, r3
 424         rev16 r7, r2
 425         revsh r5, r1
 426
 427 @ CHECK: rev    r6, r3                  @ encoding: [0x1e,0xba]
 428 @ CHECK: rev16  r7, r2                  @ encoding: [0x57,0xba]
 429 @ CHECK: revsh  r5, r1                  @ encoding: [0xcd,0xba]
 430
 431
 432 @------------------------------------------------------------------------------
 433 @ ROR
 434 @------------------------------------------------------------------------------
 435         rors r2, r7
 436
 437 @ CHECK: rors   r2, r7                  @ encoding: [0xfa,0x41]
 438
 439
 440 @------------------------------------------------------------------------------
 441 @ RSB
 442 @------------------------------------------------------------------------------
 443         rsbs r1, r3, #0
 444
 445 @ CHECK: rsbs   r1, r3, #0              @ encoding: [0x59,0x42]
 446
 447
 448 @------------------------------------------------------------------------------
 449 @ SBC
 450 @------------------------------------------------------------------------------
 451         sbcs r4, r3
 452
 453 @ CHECK: sbcs   r4, r3                  @ encoding: [0x9c,0x41]
 454
 455
 456 @------------------------------------------------------------------------------
 457 @ SETEND
 458 @------------------------------------------------------------------------------
 459         setend be
 460         setend le
 461
 462 @ CHECK: setend be                      @ encoding: [0x58,0xb6]
 463 @ CHECK: setend le                      @ encoding: [0x50,0xb6]
 464
 465
 466 @------------------------------------------------------------------------------
 467 @ STM
 468 @------------------------------------------------------------------------------
 469         stm r1!, {r2, r6}
 470         stm r1!, {r1, r2, r3, r7}
 471
 472 @ CHECK: stm    r1!, {r2, r6}           @ encoding: [0x44,0xc1]
 473 @ CHECK: stm    r1!, {r1, r2, r3, r7}   @ encoding: [0x8e,0xc1]
 474
 475
 476 @------------------------------------------------------------------------------
 477 @ STR (immediate)
 478 @------------------------------------------------------------------------------
 479         str r2, [r7]
 480         str r2, [r7, #0]
 481         str r5, [r1, #4]
 482         str r3, [r7, #124]
 483         str r2, [sp]
 484         str r3, [sp, #0]
 485         str r4, [sp, #20]
 486         str r5, [sp, #1020]
 487
 488 @ CHECK: str    r2, [r7]                @ encoding: [0x3a,0x60]
 489 @ CHECK: str    r2, [r7]                @ encoding: [0x3a,0x60]
 490 @ CHECK: str    r5, [r1, #4]            @ encoding: [0x4d,0x60]
 491 @ CHECK: str    r3, [r7, #124]          @ encoding: [0xfb,0x67]
 492 @ CHECK: str    r2, [sp]                @ encoding: [0x00,0x92]
 493 @ CHECK: str    r3, [sp]                @ encoding: [0x00,0x93]
 494 @ CHECK: str    r4, [sp, #20]           @ encoding: [0x05,0x94]
 495 @ CHECK: str    r5, [sp, #1020]         @ encoding: [0xff,0x95]
 496
 497
 498 @------------------------------------------------------------------------------
 499 @ STR (register)
 500 @------------------------------------------------------------------------------
 501         str r2, [r7, r3]
 502
 503 @ CHECK: str    r2, [r7, r3]            @ encoding: [0xfa,0x50]
 504
 505
 506 @------------------------------------------------------------------------------
 507 @ STRB (immediate)
 508 @------------------------------------------------------------------------------
 509         strb r4, [r3]
 510         strb r5, [r6, #0]
 511         strb r6, [r7, #31]
 512
 513 @ CHECK: strb   r4, [r3]                @ encoding: [0x1c,0x70]
 514 @ CHECK: strb   r5, [r6]                @ encoding: [0x35,0x70]
 515 @ CHECK: strb   r6, [r7, #31]           @ encoding: [0xfe,0x77]
 516
 517
 518 @------------------------------------------------------------------------------
 519 @ STRB (register)
 520 @------------------------------------------------------------------------------
 521         strb r6, [r4, r5]
 522
 523 @ CHECK: strb   r6, [r4, r5]            @ encoding: [0x66,0x55]
 524
 525
 526 @------------------------------------------------------------------------------
 527 @ STRH (immediate)
 528 @------------------------------------------------------------------------------
 529         strh r3, [r3]
 530         strh r4, [r6, #2]
 531         strh r5, [r7, #62]
 532
 533 @ CHECK: strh   r3, [r3]                @ encoding: [0x1b,0x80]
 534 @ CHECK: strh   r4, [r6, #2]            @ encoding: [0x74,0x80]
 535 @ CHECK: strh   r5, [r7, #62]           @ encoding: [0xfd,0x87]
 536
 537
 538 @------------------------------------------------------------------------------
 539 @ STRH (register)
 540 @------------------------------------------------------------------------------
 541         strh r6, [r2, r6]
 542
 543 @ CHECK: strh   r6, [r2, r6]            @ encoding: [0x96,0x53]
 544
 545
 546 @------------------------------------------------------------------------------
 547 @ SUB (immediate)
 548 @------------------------------------------------------------------------------
 549         subs r1, r2, #3
 550         subs r2, #3
 551         subs r2, #8
 552
 553 @ CHECK: subs   r1, r2, #3              @ encoding: [0xd1,0x1e]
 554 @ CHECK: subs   r2, #3                  @ encoding: [0x03,0x3a]
 555 @ CHECK: subs   r2, #8                  @ encoding: [0x08,0x3a]
 556
 557
 558 @------------------------------------------------------------------------------
 559 @ SUB (SP minus immediate)
 560 @------------------------------------------------------------------------------
 561         sub sp, #12
 562         sub sp, sp, #508
 563
 564 @ CHECK: sub    sp, #12                 @ encoding: [0x83,0xb0]
 565 @ CHECK: sub    sp, #508                @ encoding: [0xff,0xb0]
 566
 567
 568 @------------------------------------------------------------------------------
 569 @ SUB (register)
 570 @------------------------------------------------------------------------------
 571         subs r1, r2, r3
 572
 573 @ CHECK: subs   r1, r2, r3              @ encoding: [0xd1,0x1a]
 574
 575
 576 @------------------------------------------------------------------------------
 577 @ SVC
 578 @------------------------------------------------------------------------------
 579         svc #0
 580         svc #255
 581
 582 @ CHECK: svc    #0                      @ encoding: [0x00,0xdf]
 583 @ CHECK: svc    #255                    @ encoding: [0xff,0xdf]
 584
 585
 586 @------------------------------------------------------------------------------
 587 @ SXTB/SXTH
 588 @------------------------------------------------------------------------------
 589         sxtb r3, r5
 590         sxth r3, r5
 591
 592 @ CHECK: sxtb   r3, r5                  @ encoding: [0x6b,0xb2]
 593 @ CHECK: sxth   r3, r5                  @ encoding: [0x2b,0xb2]
 594
 595
 596 @------------------------------------------------------------------------------
 597 @ TST
 598 @------------------------------------------------------------------------------
 599         tst r6, r1
 600
 601 @ CHECK: tst    r6, r1                  @ encoding: [0x0e,0x42]
 602
 603
 604 @------------------------------------------------------------------------------
 605 @ UXTB/UXTH
 606 @------------------------------------------------------------------------------
 607         uxtb  r7, r2
 608         uxth  r1, r4
 609
 610 @ CHECK: uxtb   r7, r2                  @ encoding: [0xd7,0xb2]
 611 @ CHECK: uxth   r1, r4                  @ encoding: [0xa1,0xb2]
 612
 613
 614 @------------------------------------------------------------------------------
 615 @ WFE/WFI/YIELD
 616 @------------------------------------------------------------------------------
 617         wfe
 618         wfi
 619         yield
 620
 621 @ CHECK: wfe                             @ encoding: [0x20,0xbf]
 622 @ CHECK: wfi                             @ encoding: [0x30,0xbf]
 623 @ CHECK: yield                           @ encoding: [0x10,0xbf]