<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/64809>64809</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            MIR parser crashes on ... in instruction section
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            llvm:codegen,
            crash-on-invalid,
            llvm:crash
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          arsenm
      </td>
    </tr>
</table>

<pre>
    ```
# RUN: llc -mtriple=x86_64-- -run-pass=none -o - %s

---
name: test
tracksRegLiveness: true
body:             |
  bb.0:
 %0:gr32 = COPY ...
```
```

llc: /home/matt/src/llvm-project/llvm/lib/CodeGen/MIRParser/MIParser.cpp:1854: bool (anonymous namespace)::MIParser::parseTargetImmMnemonic(const unsigned int, const unsigned int, MachineOperand &, const MIRFormatter &): Assertion `Token.is(MIToken::Identifier)' failed.
Process 22313 stopped
* thread #1, name = 'llc', stop reason = signal SIGABRT
    frame #0: 0x00007ffff79b9a7c libc.so.6`__GI___pthread_kill at pthread_kill.c:44:76
(lldb) bt
* thread #1, name = 'llc', stop reason = signal SIGABRT
  * frame #0: 0x00007ffff79b9a7c libc.so.6`__GI___pthread_kill at pthread_kill.c:44:76
    frame #1: 0x00007ffff79b9a30 libc.so.6`__GI___pthread_kill [inlined] __pthread_kill_internal(signo=6, threadid=140737346936960) at pthread_kill.c:78:10
    frame #2: 0x00007ffff79b9a30 libc.so.6`__GI___pthread_kill(threadid=140737346936960, signo=6) at pthread_kill.c:89:10
    frame #3: 0x00007ffff7965476 libc.so.6`__GI_raise(sig=6) at raise.c:26:13
    frame #4: 0x00007ffff794b7f3 libc.so.6`__GI_abort at abort.c:79:7
    frame #5: 0x00007ffff794b71b libc.so.6`__assert_fail_base.cold at assert.c:92:3
 frame #6: 0x00007ffff795ce96 libc.so.6`__GI___assert_fail(assertion="Token.is(MIToken::Identifier)", file="/home/matt/src/llvm-project/llvm/lib/CodeGen/MIRParser/MIParser.cpp", line=1854, function="bool (anonymous namespace)::MIParser::parseTargetImmMnemonic(const unsigned int, const unsigned int, MachineOperand &, const MIRFormatter &)") at assert.c:101:3
    frame #7: 0x000055555d9f2e51 llc`(anonymous namespace)::MIParser::parseTargetImmMnemonic(this=0x00007fffffffc1a0, OpCode=19, OpIdx=1, Dest=0x00007fffffffbf98, MF=0x000055555f3b97b0) at MIParser.cpp:1854:5
    frame #8: 0x000055555d9ef21e llc`(anonymous namespace)::MIParser::parseMachineOperand(this=0x00007fffffffc1a0, OpCode=19, OpIdx=1, Dest=0x00007fffffffbf98, TiedDefIdx= Has Value=false ) at MIParser.cpp:2963:14
    frame #9: 0x000055555d9ea9be llc`(anonymous namespace)::MIParser::parseMachineOperandAndTargetFlags(this=0x00007fffffffc1a0, OpCode=19, OpIdx=1, Dest=0x00007fffffffbf98, TiedDefIdx= Has Value=false ) at MIParser.cpp:3008:7
    frame #10: 0x000055555d9e86e7 llc`(anonymous namespace)::MIParser::parse(this=0x00007fffffffc1a0, MI=0x00007fffffffc0a8) at MIParser.cpp:1072:9
    frame #11: 0x000055555d9e7a94 llc`(anonymous namespace)::MIParser::parseBasicBlock(this=0x00007fffffffc1a0, MBB=0x000055555f2e23d8, AddFalthroughFrom=0x00007fffffffc158) at MIParser.cpp:968:9
    frame #12: 0x000055555d9e3eab llc`(anonymous namespace)::MIParser::parseBasicBlocks(this=0x00007fffffffc1a0) at MIParser.cpp:1030:9
    frame #13: 0x000055555d9e3d1f llc`llvm::parseMachineInstructions(PFS=0x00007fffffffc890, Src=(Data = "bb.0:\n  %0:gr32 = COPY 

```
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJzUV11vI6kS_TX4Bdmiob948IMTq-daur4TZXJX2ieLbmibDQYL8Gjm36-KthMn7mxW0UTatSy7gabqnFNFASIEvbVKzVFxg4rlRBzjzvm58EHZ_aR18uccleT0JUtEFogyfP___yG2wMZ0eLqPXh-MQmz5oy43ZT6d4qk_2ulBhIDY0jqr8NThKUa0CCcT6Xc6nQ4PVuwVmIsqxKEnetE9hnu1_a_-rqwCQwsc_VENwwALei4_qLodBjFu2xlB7OQF3EJr6xnFiC3x7de73_FsNjtBeUXuVTP9GtOBN0SbndsrRJu9iBHRJvgO0caY7_vpwbs_VBdPTfjTLaLNrZPqi7KINuvV_R2I6tPz8DjrDgfEFlld5GC_dc5gRGthnf25d8eAQZhwEJ1ClAMhtjhPHVoHeH4Qfqviar9fW7V3VneI1p2zIeKjTbGVWNuI6C0e712Lbqet-npQXliJES2f312v7hvnga7ywwjgwIsQlI_aWYxK8uAelZ3pgGi9XqXGAG4llY2610CZI1rhXmij5En3O-86FQKmlGUMh-gOByXPCbbAceeVADAsAzQgRAoeohVEg1bQC7OwVyIAELbEwEsY_G31ZXFz_3DOBox7n6ZTBnmAyQ9CCKn6vu8r3nJRddjotpsFNytRSTabL6vNZnMYEGwetTFYRHzZnkE65BCzqjxDro2RLaIct_FTWIC5z-fxQq1szAsj73pBxY22RlslUbHELwc32kblrTCI1kDUIbZM-Ta8oyViyywnFatYXnJW8pKAqGPAqxrWDhkBTj8GHNH6r1Dc4gvA45Bq_hYkdgWpLPKqvIbkhQ5qEOfCU-pNLmgJLtiIi_zKRd5WPbt2IVrnI1hND4OWALwaMVqMGc3aV0ZFqgcbWOCbVgBSZ2TykAaSCw5ROeN-sl9e2S86xUd0eeEEiuS5BCG2RJT-zSJEIYy9TrtVan1GRR-8wAKANILiDk6PtnuG-y8p9cCEv4pjRrKLQF7mSvUcywI-kvdUFRmcEmBD_SVs407DoeIiY_q-7zKR1ufXA0QHROdDcyV_QAsaSzhbvJ7Y9rxOujRPQwl5z1petefKM75dFyMK1FcKqJ5m6sMKvIzXp9F_0EouVT-8jv8jAv5NmCNY6oUJwGxMB8pLqGpZPiIEvxZC8PZXCbGwcsiNxoht-IfJwgip3yimGbmWpS5V9WFZ3qO-Xl0PEVG_kdekghLNx4Bn18ArwfMPA78RQXc3xnWP71K4uXm1NqmiTKYALaRshIk7747bXePdfsRK8QZbXtZvkaXXZJkS7S8g-06ujkclnfZGgbIRoDLrT0DTtnW1hFY2RH9MWxGguWu-XYOpeZL-m-_SblUvRRSncys9362KW4vHr1aXN6en69REzpnkjIuJmmclp6wqq7ye7OZFycqyyllfENXRjmZtRijta1kVbUt4P9FzSigjdVZnJeOknklWyZ4qKepcSJq3KCdqL7SZAeGZ89uJDuGo5mVeEz4xolUmpNstpSdJOifVFvZw2KgRpZ0XYTd1dqrtd2G0fBo4vw_j0FksJ36eTgftcRtQTowOMTw7jjoaNV-v7nGS3OM0UwXsLNw4sbZYP-uPg0r_k6M3812MB7jlItog2mx13B3bWef2F-ePl6eSRDIg2iSefwYAAP__90es6w">