<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/75476>75476</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Clang-18 crash: Assertion `isa<To>(Val) && "cast<Ty>() argument of incompatible type!"' failed.
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
      </td>
    </tr>

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

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

<pre>
    Clang-18 with -mgeneral-regs-only -c crashes on the test case.
Compiler explorer(assertion trunck): https://godbolt.org/z/xbEqjY3s4
```
$cat mutant.c
void bar (int, ...);
struct S { int a, b, c; };
typedef _Atomic struct S T;

void
foo (void)
{
  static T x = (struct S) { 0, 0, 0 };
  bar (0, x = (struct S) { 1, 1, 1 });
}

$clang-18 -mgeneral-regs-only -c mutant.c
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: clang-18 -mgeneral-regs-only -c mutant.c
1.      <eof> parser at end of file
2.      mutant.c:6:1: LLVM IR generation of declaration 'foo'
3.      mutant.c:6:1: Generating code for declaration 'foo'
 #0 0x00007f76b924a266 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/usr/lib/llvm-18/bin/../lib/libLLVM-18.so.1+0xd2b266)
 #1 0x00007f76b9248170 llvm::sys::RunSignalHandlers() (/usr/lib/llvm-18/bin/../lib/libLLVM-18.so.1+0xd29170)
 #2 0x00007f76b92498c4 llvm::sys::CleanupOnSignal(unsigned long) (/usr/lib/llvm-18/bin/../lib/libLLVM-18.so.1+0xd2a8c4)
 #3 0x00007f76b9197bb0 (/usr/lib/llvm-18/bin/../lib/libLLVM-18.so.1+0xc78bb0)
 #4 0x00007f76c3d2b980 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x12980)
 #5 0x00007f76c1c28502 (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1cd9502)
 #6 0x00007f76c1c1084e clang::CodeGen::CodeGenFunction::EmitLValueForField(clang::CodeGen::LValue, clang::FieldDecl const*) (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1cc184e)
 #7 0x00007f76c1c286ba clang::CodeGen::CodeGenFunction::EmitLValueForFieldInitialization(clang::CodeGen::LValue, clang::FieldDecl const*) (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1cd96ba)
 #8 0x00007f76c1c36f2c (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1ce7f2c)
 #9 0x00007f76c1c2c60d clang::CodeGen::CodeGenFunction::EmitAggExpr(clang::Expr const*, clang::CodeGen::AggValueSlot) (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1cdd60d)
#10 0x00007f76c1c328fa (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1ce38fa)
#11 0x00007f76c1c3859d (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1ce959d)
#12 0x00007f76c1c2c60d clang::CodeGen::CodeGenFunction::EmitAggExpr(clang::Expr const*, clang::CodeGen::AggValueSlot) (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1cdd60d)
#13 0x00007f76c1c38cf1 (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1ce9cf1)
#14 0x00007f76c1c2fde2 (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1ce0de2)
#15 0x00007f76c1c2c60d clang::CodeGen::CodeGenFunction::EmitAggExpr(clang::Expr const*, clang::CodeGen::AggValueSlot) (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1cdd60d)
#16 0x00007f76c1c0ce2d clang::CodeGen::CodeGenFunction::EmitAnyExpr(clang::Expr const*, clang::CodeGen::AggValueSlot, bool) (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1cbde2d)
#17 0x00007f76c1c0d38d clang::CodeGen::CodeGenFunction::EmitAnyExprToTemp(clang::Expr const*) (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1cbe38d)
#18 0x00007f76c1b6f9de clang::CodeGen::CodeGenFunction::EmitCallArg(clang::CodeGen::CallArgList&, clang::Expr const*, clang::QualType) (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1c209de)
#19 0x00007f76c1b6ec60 clang::CodeGen::CodeGenFunction::EmitCallArgs(clang::CodeGen::CallArgList&, clang::CodeGen::CodeGenFunction::PrototypeWrapper, llvm::iterator_range<clang::Stmt::CastIterator<clang::Expr, clang::Expr const* const, clang::Stmt const* const>>, clang::CodeGen::CodeGenFunction::AbstractCallee, unsigned int, clang::CodeGen::CodeGenFunction::EvaluationOrder) (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1c1fc60)
#20 0x00007f76c1c2a03d clang::CodeGen::CodeGenFunction::EmitCall(clang::QualType, clang::CodeGen::CGCallee const&, clang::CallExpr const*, clang::CodeGen::ReturnValueSlot, llvm::Value*) (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1cdb03d)
#21 0x00007f76c1c291da clang::CodeGen::CodeGenFunction::EmitCallExpr(clang::CallExpr const*, clang::CodeGen::ReturnValueSlot) (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1cda1da)
#22 0x00007f76c1c6b519 (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1d1c519)
#23 0x00007f76c1c5cbdd clang::CodeGen::CodeGenFunction::EmitScalarExpr(clang::Expr const*, bool) (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1d0dbdd)
#24 0x00007f76c1c0cce9 clang::CodeGen::CodeGenFunction::EmitIgnoredExpr(clang::Expr const*) (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1cbdce9)
#25 0x00007f76c1d6551f clang::CodeGen::CodeGenFunction::EmitStmt(clang::Stmt const*, llvm::ArrayRef<clang::Attr const*>) (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1e1651f)
#26 0x00007f76c1d724dc clang::CodeGen::CodeGenFunction::EmitCompoundStmtWithoutScope(clang::CompoundStmt const&, bool, clang::CodeGen::AggValueSlot) (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1e234dc)
#27 0x00007f76c1dcc5ba clang::CodeGen::CodeGenFunction::EmitFunctionBody(clang::Stmt const*) (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1e7d5ba)
#28 0x00007f76c1dcd22f clang::CodeGen::CodeGenFunction::GenerateCode(clang::GlobalDecl, llvm::Function*, clang::CodeGen::CGFunctionInfo const&) (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1e7e22f)
#29 0x00007f76c1ded0e5 clang::CodeGen::CodeGenModule::EmitGlobalFunctionDefinition(clang::GlobalDecl, llvm::GlobalValue*) (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1e9e0e5)
#30 0x00007f76c1de6bf1 clang::CodeGen::CodeGenModule::EmitGlobalDefinition(clang::GlobalDecl, llvm::GlobalValue*) (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1e97bf1)
#31 0x00007f76c1dea92d clang::CodeGen::CodeGenModule::EmitGlobal(clang::GlobalDecl) (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1e9b92d)
#32 0x00007f76c1de58e2 clang::CodeGen::CodeGenModule::EmitTopLevelDecl(clang::Decl*) (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1e968e2)
#33 0x00007f76c1e8175c (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1f3275c)
#34 0x00007f76c1dc2efe (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x1e73efe)
#35 0x00007f76c09df93a clang::ParseAST(clang::Sema&, bool, bool) (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0xa9093a)
#36 0x00007f76c2837645 clang::FrontendAction::Execute() (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x28e8645)
#37 0x00007f76c27b5cc4 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x2866cc4)
#38 0x00007f76c28b21c0 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x29631c0)
#39 0x000056449f711837 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/usr/lib/llvm-18/bin/clang+0x13837)
#40 0x000056449f70e905 (/usr/lib/llvm-18/bin/clang+0x10905)
#41 0x00007f76c244d909 (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x24fe909)
#42 0x00007f76b919794c llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/usr/lib/llvm-18/bin/../lib/libLLVM-18.so.1+0xc7894c)
#43 0x00007f76c244d2ae clang::driver::CC1Command::Execute(llvm::ArrayRef<std::optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x24fe2ae)
#44 0x00007f76c24150f1 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x24c60f1)
#45 0x00007f76c241533e clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&, bool) const (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x24c633e)
#46 0x00007f76c243139c clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/usr/lib/llvm-18/bin/../lib/libclang-cpp.so.18+0x24e239c)
#47 0x000056449f70e25c clang_main(int, char**, llvm::ToolContext const&) (/usr/lib/llvm-18/bin/clang+0x1025c)
#48 0x000056449f71bf32 main (/usr/lib/llvm-18/bin/clang+0x1df32)
#49 0x00007f76b772ec87 __libc_start_main /build/glibc-CVJwZb/glibc-2.27/csu/../csu/libc-start.c:344:0
#50 0x000056449f70b1ea _start (/usr/lib/llvm-18/bin/clang+0xd1ea)
clang-18: error: clang frontend command failed with exit code 139 (use -v to see invocation)
Ubuntu clang version 18.0.0 (++20231018091808+48a53509e851-1~exp1~20231018091910.1571)
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/bin
clang-18: note: diagnostic msg: 
********************

PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang-18: note: diagnostic msg: /tmp/mutant-2959ae.c
clang-18: note: diagnostic msg: /tmp/mutant-2959ae.sh
clang-18: note: diagnostic msg: 

********************
```
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJzkWk1z4zbS_jX0BWUVPvh58EGWrYlTzjvz2sqkdi8qEGjKTCiCC4COnUN--xZIShY4lmes4aZSuylHI5FNdD8PGt0NsLkx5aYGuAiiyyC6OuOtfVD6ouRbXqv6eataI8xZruTzxaLi9eacpOj30j6g8-0GatC8OtewMeeqrp7RuUBCc_MABqka2QdAFoxFghuYBfgqwPOF2jZlBRrBU1MpDTqgKTcGtC3dE7qtxW8BzQI2Rw_WNiZg84AuA7rcKJmrys6U3gR0-UdAl0_59b9-_QczYT9yEOPhr_9JQ8Et2raW13Ym-ouPqpQo5xoFNC1rG9AFms1mnb7LXsJY3QqL7lGQXKKytog7odx9iIBdoiC52sva5wYkFGg9t2pbCrR_drUXeVHbfyuUcrq7CzQbZJJBGCFjuS0FWqEnFLArJ7kbM6BZZxJ2lvQfni1oB6u7d_Rx4u72H93jB8jdzwObHX-7-T4y1T63n26v5_fXyLT5trSIo7zdIA2N0hZZNZ7M0j60-UyobUCXVfW4--e80epXEDagy9KYFkxAl4jXEpW1qFoJnUt1HoZyLn6zmgtwYBoNjVYCjAGJjGp1f9k9yY1RouQWJNJtjYzQZWMHZ7y3XPyGZLttnGXdJTxD3X-ftNpovkVcb9ot1NbZjt5HCBmGCtgCVBGwa9RwbUAjbhHUEqkCFWUFvTAdhPdDsHkcsDlxam9vP_-Ebu5Qr7NbKKpAEkTFh58BTQqlApr0g7E3BvswDFJvkFASUKH0W0OhgDKM8BPGGCdFEucZDTmNY9TNGpsHbG6eTf_lky5r23G66icmfRHS_Pe1MlYD3wY0dpPTrb_MOWlAl63RzgXKfOcIxF3NyzqgS7dAd7fK3JFxTtKZUTMS0Ev8JGlO43i_mpzBZGRwShL8msF3bX1fbmpe_cBrWYE2nTGT2JSRBHs20ZFNWSrC12xaVMDrtvk4WBbQtK27CC1RperNRObxVISeecwzj2RJnuPvVySSNM99HsIDRYJJmmcpRuu1BmOVhrW2g9Z-0Kc0XsfheVXW7dP5pm77G4190MCl04M7PYRmqa8mOlRDBE0jTN-Np1_vomk6RGmvSsgswtRTFvvKCE5D6IPFMKdKwgeovR_LthZuwfUXr7elvf3MqxaWSi9LqGRA02Mj9IJdSnqR6B66AlEhoWpjAzo_xVVeRyxIGoKHOBnTG-f8exHf1KUteVX-0QWivxN-mcU59_CnPn4WF1RMpAySggpPWTYiW8RYvp_s-WZz_dRon1d35YCwxdFh55tNx_p9pU4K20eIlTE-KIQoI3hELE0LPhWxLC24p4yMlKVRJqdSlkWZj4z-D80iGxMrCjIZsaIgnrJwRGwhYapQD1gC9ZSN88p_8yyO0hoWQE_BWj9PhnWBcqWq6TDnEqiPeZTYsGTp6ZhXagXb5k3kkyEBlvpI_BSVx0UmTyhKFryq5m7LfTQbDxK3pUMUj-byrXn-_5ZXq-cGpiOB4kyCR0I2IgFEjE8mwZzKwte1fNLKKvvcwC-aNw1oN8DL5qC0bsum9FrzegMBWxyMfW-3dmeCsTeDpC_Tr7_jE7P74km4gccS7Nr9vRfcPDdup97RCF3dtt_SDIcw75uRR161XY34UUtH1VTuQwoR40P3oaNqhHLMTogGDrfvOi-u_wb2Dz1fuzn4wql4VX1zGL0D2-rai6Qv7jWU01MWzDlmXjSio1KLZkSesGHYYR4txO9iYjLMnEivvKSjii_OIzKRMklERDJP2ajkikQuT3DVe8Errr8hX0-ahyWWufT9JRzXHgKy98O52dRKg_wqnunqCQH-tPj1ooyjiBQnTIsL8h4ALzr7y3muNX--g8LPAXNrDxC7KD4RaCBxRAoPtF84yoSGUpyw2NW2UW0tHdRfSvugWnsvlAuafhZ-kfJCZe-hf3EVDZSFUnhk-BWlFCI65ahkd-VSyec3PWEqIImMcj-cpSMgktJ3uvJw9gzupg_iQ6VyXl2BqHxf3j__dlBffNgJ3tSFOnCDydgASn0f9ytLCRJD9DU2flKyreBlUnvUO9OvoCjr8suzr2Pc9NcnT96QAYboECvDI6xxXpDTsP5tMCa5f4rAyAgjz76-2X0d43Fkk1mfZ_62ldGR9VEK9L3Wr1RzC48w2HqIob8yJf1x6p-rML98gZQk0UQHqgWjSeSFZP8dBJGCQgFTBQoGhbcF9d9E4EwWGfPi_yeuDczvV6OoDls-SmRTllw8wxnzwrv_EoOmLIlDL6Attaot1HJ-mJmeQLQWTnxt9pphNIU0Dv3w42VQmuSRECEalQBlBfqmNpbXAjzbBnM9ckdQpksUNI1jcfBmzVmf-rzmlAjs78Q7O19APCrx6huQEcjp1iPNYkaEt_Pdv3OI4jDMioSQlCVICLLecjdq-nq5-cBHNeYC-dfoAvW9D99ofE9At7RYypJDE0Psm4ghw9H7hsQZ9jwt9JIADUOZ4YkoDgvIsLc1COn4lWsWioPUt9DcPNyBUI-gnxfOYZ-Gg567tr7nBVTP3jwUQxmx1t1cdK0u_cI8sdp_7W1uFnqRNGRjwij3DhmlLh9BD4AWZKG2W17LcfB41ZmMHeRU42DxKmCLF8F7q8t600nuzqT2D6zX4umJkP5Hzk0p1qYTH1zUE3YX1lbz0prd7dFwvKrciuwP1Yb7TuRgH9x5c-fkk3kL5V4aCUOfaRJhvwbzmO5iBf8iTu_o9wLL6EEncOzI6Q3RuZespiVDxNgv1sJoTAZjx93uCBk_qtwcZ-JHld-Wxt9RHnjfllfVZxBW6ZttUx16a8NL5yhfHmy-Sd7gUv9BChnz_clP9yEjLBPHzL06-O6lq1fy1DHq_0IKpwrZQFnmh7tknHJoNJC2y4s7o7swM__ibGalVDXE8nfuUg_TFvXr2TAdJeu8YBQ5g943riyYV5SHh3vcPEkoiDRB67UjbG0s13Y9KFnmbVnJgC437t754vOPv_8z3_-kM5o4TabdEd9_7W5243QtaiwMAzbft2-yaJzgcwIc9YrfBUwSeCl1dz18AZsj0NpF9aGxDxVDWYjE4FsFLyuQfbsrPJW275gjrJuv1gA6f0RWIQOAyoOybdD0c97Wth3GfgRtSlUjks7wbOisugzoJcWUEUxSnJEUu2thyiMW4QzSiJyTP-GpIX8eCGUEz0iUvITDFdcbcIUBGnqlGnHQLtWLdN1SaKskVE6wUaZ86m911WRVgbwqOyL2nDoOv-CrVtYV10iWfFMrY0uBtmbTPTdM2nf8HfSeDq2k89VqvvgBrX64RsuPt7cff7n5vw9oeXN7fY9WH7vLlz9_QHfXnz7erYJdA-en11pBU-MW2dF20L2ABtTlepCI2_2Q30gBXdptE9Bl33V5TrMo47BrBv2uMczDCXMx1Yzs2qrP5AWTGcv4GVyQBNMoZmnEzh4uGGMiwzLH4P4vRErStMAiLuIwIzGkZ-VF58CUhCSkIWEzGqcxFjijeUFyGtIgxLDlZTVza3im9Oas6_69SKIwic8qnkNldv3p-qJb6Hm7MUGIq9JY8_KYLW0FL33qXaewo2S-7zAPYlwaHrDFSnXpIv3Mh011HNAYBZQKbqy7_9zf7_2ibwJGqkBlLdS24bbMK0C2e4dHAkoDmgzhYnbW6uri9H7nDvS_AwAA__8cQ_On">