<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/107939>107939</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            m68k fails to select atomic store where address is sum of two registers
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            new issue
      </td>
    </tr>

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

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

<pre>
    encountered when trying to build Rust's standard library for m68k:
https://rust-lang.zulipchat.com/#narrow/stream/187780-t-compiler.2Fwg-llvm/topic/M86k.20Compilation.20Failures/near/468939538

reduced:
https://llvm.godbolt.org/z/qP4nsoq58
```llvm
define void @f(i8 %v, ptr %p, i32 %o) {
start:
    %p2 = getelementptr i8, ptr %p, i32 %o
    store atomic i8 %v, ptr %p2 monotonic, align 1
    ret void
}
```

```
warning: overriding the module target triple with m68k-unknown-linux-gnu [-Woverride-module]
fatal error: error in backend: Cannot select: 0xb912ff0: ch = AtomicStore<(store monotonic (s8) into %ir.p2)> 0xb8cf930, 0xb912ab0, 0xb912f80
  0xb912ab0: i8,ch = load<(load (s8) from %fixed-stack.2)> 0xb8cf930, FrameIndex:i32<-1>, undef:i32
    0xb9129d0: i32 = FrameIndex<-1>
    0xb912a40: i32 = undef
  0xb912f80: i32 = add 0xb912b90, 0xb912c70
    0xb912b90: i32,ch = load<(load (s32) from %fixed-stack.1)> 0xb8cf930, FrameIndex:i32<-2>, undef:i32
      0xb912b20: i32 = FrameIndex<-2>
      0xb912a40: i32 = undef
    0xb912c70: i32,ch = load<(load (s32) from %fixed-stack.0, align 8)> 0xb8cf930, FrameIndex:i32<-3>, undef:i32
      0xb912c00: i32 = FrameIndex<-3>
      0xb912a40: i32 = undef
In function: f
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script.
Stack dump:
0.      Program arguments: /opt/compiler-explorer/clang-18.1.0/bin/clang++ -g -o /app/output.s -fno-verbose-asm -S -x ir -fcolor-diagnostics -fno-crash-diagnostics --target=m68k-unknown-linux-gnu <source>
1.      Code generation
2.      Running pass 'Function Pass Manager' on module '<source>'.
3.      Running pass 'M68k DAG->DAG Pattern Instruction Selection' on function '@f'
 #0 0x000000000351ae38 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0x351ae38)
 #1 0x0000000003518f84 llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0x3518f84)
 #2 0x0000000003467543 llvm::CrashRecoveryContext::HandleExit(int) (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0x3467543)
 #3 0x000000000351097e llvm::sys::Process::Exit(int, bool) (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0x351097e)
 #4 0x0000000000c17976 (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0xc17976)
 #5 0x0000000003470593 llvm::report_fatal_error(llvm::Twine const&, bool) (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0x3470593)
 #6 0x00000000045d3174 llvm::SelectionDAGISel::CannotYetSelect(llvm::SDNode*) (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0x45d3174)
 #7 0x00000000045d9135 llvm::SelectionDAGISel::SelectCodeCommon(llvm::SDNode*, unsigned char const*, unsigned int) (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0x45d9135)
 #8 0x00000000024cc97b (anonymous namespace)::M68kDAGToDAGISel::Select(llvm::SDNode*) M68kISelDAGToDAG.cpp:0:0
 #9 0x00000000045d06f7 llvm::SelectionDAGISel::DoInstructionSelection() (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0x45d06f7)
#10 0x00000000045dda15 llvm::SelectionDAGISel::CodeGenAndEmitDAG() (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0x45dda15)
#11 0x00000000045e06df llvm::SelectionDAGISel::SelectAllBasicBlocks(llvm::Function const&) (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0x45e06df)
#12 0x00000000045e2dc9 llvm::SelectionDAGISel::runOnMachineFunction(llvm::MachineFunction&) (.part.0) SelectionDAGISel.cpp:0:0
#13 0x00000000029bc2f0 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (.part.0) MachineFunctionPass.cpp:0:0
#14 0x0000000002ee69e2 llvm::FPPassManager::runOnFunction(llvm::Function&) (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0x2ee69e2)
#15 0x0000000002ee6b61 llvm::FPPassManager::runOnModule(llvm::Module&) (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0x2ee6b61)
#16 0x0000000002ee87e0 llvm::legacy::PassManagerImpl::run(llvm::Module&) (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0x2ee87e0)
#17 0x000000000378ad99 clang::EmitBackendOutput(clang::DiagnosticsEngine&, clang::HeaderSearchOptions const&, clang::CodeGenOptions const&, clang::TargetOptions const&, clang::LangOptions const&, llvm::StringRef, llvm::Module*, clang::BackendAction, llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>, std::unique_ptr<llvm::raw_pwrite_stream, std::default_delete<llvm::raw_pwrite_stream>>, clang::BackendConsumer*) (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0x378ad99)
#18 0x0000000003d5a8bf clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0x3d5a8bf)
#19 0x0000000003fe2aa1 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0x3fe2aa1)
#20 0x0000000003f6010b clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0x3f6010b)
#21 0x00000000040c2473 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0x40c2473)
#22 0x0000000000c19746 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0xc19746)
#23 0x0000000000c1211d ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#24 0x0000000003da1979 void llvm::function_ref<void ()>::callback_fn<clang::driver::CC1Command::Execute(llvm::ArrayRef<std::optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const::'lambda'()>(long) Job.cpp:0:0
#25 0x0000000003467443 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0x3467443)
#26 0x0000000003da1b99 clang::driver::CC1Command::Execute(llvm::ArrayRef<std::optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const (.part.0) Job.cpp:0:0
#27 0x0000000003d69d17 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0x3d69d17)
#28 0x0000000003d6a6cd clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&, bool) const (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0x3d6a6cd)
#29 0x0000000003d7445c clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0x3d7445c)
#30 0x0000000000c16a21 clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0xc16a21)
#31 0x0000000000b0fa84 main (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0xb0fa84)
#32 0x000070bdd3029d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#33 0x000070bdd3029e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#34 0x0000000000c1191e _start (/opt/compiler-explorer/clang-18.1.0/bin/clang+++0xc1191e)
clang++: error: clang frontend command failed with exit code 70 (use -v to see invocation)
Compiler returned: 70
```

</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJzkWktz47ay_jX0BiUVCVJ8LLyQJWsyqcwd13jq3rorFUg0ZcQkwACgH_n1pwCQEsGRx86JcjYnlZmh8Oqvv250N0ASpdiBA1wHq5tgtb0ivX4Q8rqT4iBJ24L8nTzCVSno6zXwSvRcgwSKnh-AIy1fGT8gLVDZs4aib73SAc4UUppwSiRFDSslka-oFhK1af4YxOsg3Abh-kHrTplfeBfgneyVXjSEH5Z_9g3rqgeil5VobWfMiZTiOcA7pSUQ0xjlWZaHC72oRNuxBuQS754Pi6Z5Mr1adKwK8O5Lnj4ucbixY4hmgi9xuCOs6SWoAO84EBngXZLmRVys4twBc39LoH0F9A24RtDyIGgpGr0U8hDg3Z8B3v1xl3Al_liNK6Wh-9_isk0UasYBPQlGUZCEdYBzlqMAr54CvEGdlua5M88sxuZZBLhAQXbjpitNpD5iQgjZ4RgF8RYdQEMDLXBtlmH5mwse5yotJCCiRcsqdAYGRq3gQgtu2Nwg0rADR9FpvgRtNRm0zbYztad8zhqfieSMH4J4jcQTSMmo9aMHQK2gfQNIE3kAjbRkXQPomekH6z6Lnj9y8cwXDeP9y-LAexSsbhb_NywCCzc9WA1YaqJJg0BKIY0s-4AYRyWpHoEb86IN4VxopKCBynCLwpeyiHBdh-ZH9WDJXVuS7g1hQbwJcO64O_KDTFNubMW4FoY9JpcdDnARxLdmxbyqizg0NLrlSTn5UefhyOqpN147Iw4IGkGoE22eTvJqKVojr2YvQBdKk-pxeVbuTpIWPnMKL0G8ZjEO4s0iCuJb09dzCvXQfDSvg1JQByV2XjZdZZg_m0ASb4Jb2tPOqDsZQSgdOspiQkqVhfOlTb-b-FNeTPd5YqKPEoN_RswRDv4JNdij5iPkoInif0vL8LRb848qHH9E4Sr8icLxX1T4M0d1zysTls2IofXut9v1_S1SfdkyjQgq-wOS0AmpTZbxo_CB6Ye-HPLEEPvNP4tOit_NZsY7plRvYz0inCLGq6anYONMJYl6sHFAS1KBjXsSOikqUAooUqKXrtnMJEqJihENFMmeI1VJ1umlg3xvSEe0b7tjZA6XQVjcuQyKiDz0Jiwb4CjAO9EZZGPmWsBL1wgJJhNVJgMuonwZGRvuSsbHxgDfBPgGLQ5oYaLLjnSdWanXXa-XCi1qLhZPIEuhYEFUixb3aPGCmESLuhKNkAvKyIELpVk1jLb6-80LF3SDePtWqI03Ay2jqSOj6EZQQAfgIG2SdT3Y9HzruQnzqCNKoQBnu8Hg6M40fCGcHIziGRJ8DPwBzjwxOBtojs8t-CXNH9F2_WkRxLfb9Sd0R7QGydFnrrTsnax7G9kNMCdo9DoryubgbPDbAMchCl_C8b94FRGIc2R9K14H8Vq9KvdwJxnX1vLfnfvkp0GSPO_FWKukNvdybfM4zv-W_QN8E74MoMzGPqKOZqjzOk_Ood40QHjffeX37MBJE-C857b6o6gRRsrlMBoIHkbsYUzSbJXEE4wb44_foDKZ_HUjuIYX7Xp-IZw2cPvCtKmWLsmkA-GhjGdMhkUG5-1vA4X7McW2QaUQzSWZNBA8jMkUY1hFWZGll5Hm1vKErXyzZeGqmJrNxea9rbP2rs6aboXvz6bcrQQ354L08uw4PB7gdAo4WdE4yqZ74RgNtutPn--hGbzPFoH_D9p1ezrcb_9HUAjw-mKwB1Qe7GwGu4ji1buwXauJvxvRtibCncdt8vqwz6sHIkeD-D2X3FqDAp6G-VRDnFRVkZVGGuGCv7aiV4iTFlRnw2nhdDDxfbv-9F2cUfttI5lZZvQ4c1l1JjeH9s8RTzFjPEzr7F3Gt2KSWiaZJb8kdQbJkToT3sMZVEqi953DuMUn4GtOb1umt-tPF0ZpQHgoIx8lhCmtP-jC66a5IYpVN42oHpVn2WPNcIoiF9PBQvR0wDMdMK2Kd3WQPf_Kv5DqgXEY4Xo6_NA3KrHsiNQGYoHmS__otAafl59wUVa4DtGbgkyZNYF4FttPQZ1Z7zwuLydhgLQAPMG1uzNTx4LvLyP6-7YeIHm2Xs0xl2n0Acxf3BWDZ9-h6bJ4yzTy8KYzvHkGU9s3cCDV61CenJB_bruTm_7zqA0oD7WX2OIsJ7QokJvoiqeW6Rt3HfPVnmcCnE-6t6cTyi0_MA5DHTEZ8gsQCvIeiKwevnbGc5RXckyGDjHxnVHf7TnonUG_EX44N2QSLLRk_PANar95pH09W3AgYT34_nTKZ65lr9gTfIN6w_WdlkG8OXU_1cMu37EG7l-VhnY4zitNXU_P2R897LvZTHNU6Z4l07AfDyyTSRRq0jd6T6EBDe9MjG8HmT-qtBFc9a1xo8vVUIMnea7mVRgxXZG8rM9Yfz1eOtjSHapew_riaXwQ7-HzKo64BkxINMW3k-bcc3SBKcCLQnOSp9Cwf-6t0zAKS586J8xUP4Sbo_k59t7W5YJBZkDnwfdLj7DCSRZ7QcYBPWnxJCryI-gftLxk0e9QebDx7CRXZEmKqirat4T5sXotJXk1oSTe-BX8sOfmVb29l78geofNAx_PwOMoomgkehN9twe9aYnekqb5X6i0GHLSGU1mEdSsMdwFeOUflewJ5NlKBCd-ECBRkRXuhctp3fEKaC8to-51DB4uS92QijRNSarHfc0N0pOPONmDv2wic_AinM4361nLHQOrsHmDNF5IPaWLYyg9Ttjvq5eXKHI_SlMpm7Br36BYFr3BpmGvJWFajd2z5UjTGP8XctJvhqxPJ3TrOo5zOyXAWUPakpIAZyeqcD7eG_0qyvP2WM3vfZIP3vt86_k9qaF59ej8uekueTWUJP5mTeeOVfqFzH-dY8zOCm96gF8B0rSgUfYmcaeXtfPIbdn0wvVsohnwVrX2k6Hr2c3UUbdLFAFWWc-NZkVKStKK_lU2fhWlepuKX0X5G1P6rar0hzB8tH5HmDH8cI_5UfYGF_kHOTQUeRz6hRTNkmRVvYV3O3n2yoAz-f8t7v-DHF6s_LSkTFnz322EVZQSPJSfY70xoraBYz1s-_fT8YUqDIPHA-xVdWEZ1iRPkIF6GYluQU_iWJBlYUlpHOKCFuEgrGFlgHcvebpPk9M7MddRLZVYpu4IbKZ4a8bzNSEJ0X5vpu3tBx37iUoflgKJL2X-UiAqIkBu_UvZxyx5lDntHr-ssB9MmHZUD9U_qgZPrwlrgLoPOeCFGf-hgDJLbq8ALZ6QFkgBIDapzQdZY1mOJOhecvtZDho_D5h9WXJFr2NaxAW5gusow6sCp2EcXz1cJxU2TkRJVlYkK1YkzcN4hfOiCKMiSdMrdo1DnIRFWOB4Fa_iZVbiJIK4rElS4TIrgiSElrBmaT__EfJwZV8vX0dhVsTFVUNKaJT9jApjDs_I9gYYB6vtlby2b6bL_qCCJGyY0uq0jGa6ges2zR8tT8pR0UClx69z3Ocmzw8gARFKJSiFmEKqb5GokX4WSMKBKQ1SXfWyuf73X5QPyjxd438FAAD__7w5Qx0">