<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/150384>150384</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            clang-20 crashed with vector_size attribute on __float128 with asm. Assertion `isSimple() && "Expected a SimpleValueType!"' failed.
        </td>
    </tr>

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

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

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

<pre>
    clang-20 crashed with `vector_size` attribute on `__float128` with `asm`.

Compiler explorer (assertion trunk): https://godbolt.org/z/b19vd149r

```
$ cat mutant.c
__float128 __attribute__((vector_size(32))) a;
void b() { __asm__("" : "+r"(a)); }
```

```
$ clang-20 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: /usr/lib/llvm-20/bin/clang -cc1 -triple x86_64-pc-linux-gnu -emit-obj -dumpdir a- -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name mutant.c -mrelocation-model pic -pic-level 2 -pic-is-pie -mframe-pointer=all -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -fdebug-compilation-dir=/home/code/reduce -fcoverage-compilation-dir=/home/code/reduce -resource-dir /usr/lib/llvm-20/lib/clang/20 -internal-isystem /usr/lib/llvm-20/lib/clang/20/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/11/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -ferror-limit 19 -fgnuc-version=4.2.1 -fskip-odr-check-in-gmf -fcolor-diagnostics -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/mutant-c86c8e.o -x c mutant.c
1.      <eof> parser at end of file
2. Code generation
3.      Running pass 'Function Pass Manager' on module 'mutant.c'.
4.      Running pass 'X86 DAG->DAG Instruction Selection' on function '@b'
 #0 0x00007f18e418b816 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/usr/lib/llvm-20/bin/../lib/libLLVM.so.20.1+0x101f816)
 #1 0x00007f18e4189410 llvm::sys::RunSignalHandlers() (/usr/lib/llvm-20/bin/../lib/libLLVM.so.20.1+0x101d410)
 #2 0x00007f18e418becb (/usr/lib/llvm-20/bin/../lib/libLLVM.so.20.1+0x101fecb)
 #3 0x00007f18e2c49520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #4 0x00007f18e47ca894 llvm::EVT::isExtendedVector() const (/usr/lib/llvm-20/bin/../lib/libLLVM.so.20.1+0x165e894)
 #5 0x00007f18e47a1899 (/usr/lib/llvm-20/bin/../lib/libLLVM.so.20.1+0x1635899)
 #6 0x00007f18e49f99b5 (/usr/lib/llvm-20/bin/../lib/libLLVM.so.20.1+0x188d9b5)
 #7 0x00007f18e49d8b13 llvm::SelectionDAGBuilder::visitInlineAsm(llvm::CallBase const&, llvm::BasicBlock const*) (/usr/lib/llvm-20/bin/../lib/libLLVM.so.20.1+0x186cb13)
 #8 0x00007f18e49bfaff llvm::SelectionDAGBuilder::visit(llvm::Instruction const&) (/usr/lib/llvm-20/bin/../lib/libLLVM.so.20.1+0x1853aff)
 #9 0x00007f18e4a61558 llvm::SelectionDAGISel::SelectBasicBlock(llvm::ilist_iterator_w_bits<llvm::ilist_detail::node_options<llvm::Instruction, false, false, void, true, llvm::BasicBlock>, false, true>, llvm::ilist_iterator_w_bits<llvm::ilist_detail::node_options<llvm::Instruction, false, false, void, true, llvm::BasicBlock>, false, true>, bool&) (/usr/lib/llvm-20/bin/../lib/libLLVM.so.20.1+0x18f5558)
#10 0x00007f18e4a613a4 llvm::SelectionDAGISel::SelectAllBasicBlocks(llvm::Function const&) (/usr/lib/llvm-20/bin/../lib/libLLVM.so.20.1+0x18f53a4)
#11 0x00007f18e4a5f354 llvm::SelectionDAGISel::runOnMachineFunction(llvm::MachineFunction&) (/usr/lib/llvm-20/bin/../lib/libLLVM.so.20.1+0x18f3354)
#12 0x00007f18e4a5d729 llvm::SelectionDAGISelLegacy::runOnMachineFunction(llvm::MachineFunction&) (/usr/lib/llvm-20/bin/../lib/libLLVM.so.20.1+0x18f1729)
#13 0x00007f18e45884e2 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (/usr/lib/llvm-20/bin/../lib/libLLVM.so.20.1+0x141c4e2)
#14 0x00007f18e42de2be llvm::FPPassManager::runOnFunction(llvm::Function&) (/usr/lib/llvm-20/bin/../lib/libLLVM.so.20.1+0x11722be)
#15 0x00007f18e42e3df3 llvm::FPPassManager::runOnModule(llvm::Module&) (/usr/lib/llvm-20/bin/../lib/libLLVM.so.20.1+0x1177df3)
#16 0x00007f18e42dea11 llvm::legacy::PassManagerImpl::run(llvm::Module&) (/usr/lib/llvm-20/bin/../lib/libLLVM.so.20.1+0x1172a11)
#17 0x00007f18ed9708b7 clang::emitBackendOutput(clang::CompilerInstance&, clang::CodeGenOptions&, 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*) (/usr/lib/llvm-20/bin/../lib/libclang-cpp.so.20.1+0x1e3c8b7)
#18 0x00007f18edd41556 clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) (/usr/lib/llvm-20/bin/../lib/libclang-cpp.so.20.1+0x220d556)
#19 0x00007f18ec8a5f89 clang::ParseAST(clang::Sema&, bool, bool) (/usr/lib/llvm-20/bin/../lib/libclang-cpp.so.20.1+0xd71f89)
#20 0x00007f18ee7c42cb clang::FrontendAction::Execute() (/usr/lib/llvm-20/bin/../lib/libclang-cpp.so.20.1+0x2c902cb)
#21 0x00007f18ee738ea4 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/usr/lib/llvm-20/bin/../lib/libclang-cpp.so.20.1+0x2c04ea4)
#22 0x00007f18ee847a0e clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/usr/lib/llvm-20/bin/../lib/libclang-cpp.so.20.1+0x2d13a0e)
#23 0x000055c3d88eb0f3 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/usr/lib/llvm-20/bin/clang+0x120f3)
#24 0x000055c3d88e7ed5 (/usr/lib/llvm-20/bin/clang+0xeed5)
#25 0x000055c3d88e72de clang_main(int, char**, llvm::ToolContext const&) (/usr/lib/llvm-20/bin/clang+0xe2de)
#26 0x000055c3d88f4716 main (/usr/lib/llvm-20/bin/clang+0x1b716)
#27 0x00007f18e2c30d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#28 0x00007f18e2c30e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#29 0x000055c3d88e5d75 _start (/usr/lib/llvm-20/bin/clang+0xcd75)
clang-20: error: unable to execute command: Segmentation fault (core dumped)
clang-20: error: clang frontend command failed due to signal (use -v to see invocation)
Ubuntu clang version 20.1.8 (++20250708123929+0de59a293f7a-1~exp1~20250708003944.130)
Target: x86_64-pc-linux-gnu
Thread model: posix
InstalledDir: /usr/lib/llvm-20/bin
clang-20: note: diagnostic msg: 
********************

PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang-20: note: diagnostic msg: /tmp/mutant-cc6015.c
clang-20: note: diagnostic msg: /tmp/mutant-cc6015.sh
clang-20: note: diagnostic msg: 

********************
```
</pre>
<img width="1" height="1" alt="" src="http://email.email.llvm.org/o/eJzUWl9znDiQ_zTyi0pTIGCABz8wHk-SquTiir3Ze5sSUjPWBiROEo6zD_vZrwSMgYmdONm5u7qUK2Ahdf-61f-kNrNWHhTAJUo2KNlesM7da3MpWcOUVt8a3VluL0otvl3ymqkDoQHmhtl7EPirdPcYrYMH4E6bvZV_A1oHmDlnZNk5wFr5z_t9VWvmQpr5r8dFzDZoHaxQUKCguNJNK2swGB7bWhswGNGMWQvGSa2wM536gmiOogLfO9daFBWI7hDdHbQode1W2hwQ3f2N6K4M8wcRxrkZKKN1MP4EBaIx5szhpnNMuRVHQTFhw_v9E_D9HtEM0WwuGM0i6iH0P5ihaIOC4kFLgct-co5RuvFEbDMup4hS7CH3rxvTPzI2Eok2GKXbU4TPAD5qfYb65v11cXuNbVc20mGGy-6ADbTaOOz0qYaku-_KFdcNoru6fjg-SGv0X8AdojtpbQcW0R1mSmCpeN0JwO4ehp3GJeNfnGEcEL3CrYHWaA7WgsBWd2YY9iuZtZpL5kBg0ylsuZGt8zt86xj_gkXXtB5WUAQr3P-7MfpgWIOZOXQNKGcHbe06azxKWR6x0sDvrFSI7np9YMJ5iIkzsq0BP2br_TomLSe1VN0jOagOE2ikI7r8CxPPV0iDGcFESMvKGkhlADDhNTBDmHWkhEobIF5SUGKa13N_ACMrCaYf5swI8sDqDohiDVhMGiYVqWQ9DDztEyaNgVpz5k2YNFpAjVvJMWklJzU8QI3p8Iu0pJWASVMZ1gBptVQODIq2rK4xqRrm7gkYozQmVdUSrpXfDYeirVaYVEoTozslpDoQPxeThmtlnem89RJWS2Y9zqpTX6USxHnJLIq2FBPHzAEc4W3ntUjWMSauU9APHECB8YAFlN3hAMZ_kuqAou1BlJhU_Tjhve8OUgrpYSO6u9cN-M3Swj8MiI4DJhXXD2DYAX5lkYHByvy8l41j-L03DkR3NMCkV6JiNZH2m3XQvH6td4nRCX5ERXNWv3Jqz-DAOaK70VifLBXRXRgiulutvv_vmbnfc4NH_8K_5zpOfYbOj1f_OgtMKjBGG1JLH5DCHJPqoDruPcdKrVC0jVd0FWJS2S-yJVoYwu-BfyFSkUNT9ZZRa0OEZAelrZPc2ysTwlh5wGS737-5utq_LT5f77d_Fp92dH-1e7cvbj-gaBtioj0i17SI7gbvIzxb8wxWGpNHzOehMxxDD4quQFcousYtMxYMZg57z9cV9q6MgoKu8JUWMLhBb6koKKJx-adOeVfALbMWI5ruOsX7VHXjBz4wxQ5gEE19Cmy06Grws55w0NSHxfgFYv-ZrfG2eENQdL0t3uB3oy978rdQQ_820q6OfBFNURyU_hH4GBoFOHgMgiBIqzCDOMzKLFzjPv5HBYoK-80OLzdGKtcH6LshxGfTJMO-7rV1BliD6NqHealcn-p8fvthmO7td_wky_fvP39YWb2iwSpEdBM8hkFYZeHaJ8IBbngCN4_D4Dm4nzp1Kw-K1W-ZEjUYe0y-Z0Ak4jCYENFTBQIvzyM48HJiE83ZUB7nCQ1GNgOVZ4JALUvuqa57kjFN6Ax3vMCdcpbl8UyT15_vhhdprx8dKAHic1_mjIrsU8cZ5FwnkOXxBCtZwmJhlp9j19ZRkuX5xGa9YJNXeV4mZ2CTZSIvk4lNumQjsjKMZkp-ctNt8WbTyVr4dO4_PEgr3TtVSwWFbRbOdsXqesMsDDsw-tv0ecOs5Jta8y_HCcV57D5b8zKMJtGypWhlxarq1aItJJoHrkmos2BOIlZVE-Z8gZmtwyTJXsD87hbq-eik1wV2WUvr9tL50K_N_uu-lL48vTqdIcAxORJUWsBet57RcupMEX5TK1ZbWLz4c4R_OtPBS9uOouvFmn7uMPb_FHapdX0-k6iSJMkGk_D5JDg1iYjFrzSJonfEEb9dmMVTnj-zPVdJxOIJ_DIbsqSKkp-DN536qD4wfi8VHHEuwH_37WzooyiZoacn6EVK8x-gfw8Hxr_9n8sQpjSfZFik5TjJshgofhGGr_pmAjyL_OyQ45DHQCfIy8RPBdASZpB3Nx7lsTT93wYbppSWMIFdlgMUIlFFrwD7oa-llxYxDp0NaCqqaAK6PtUqC8MZ0HpmvDPI75p28sr_WbiU-fPjEe6iMBF5GmRlOtwhDeyhkW4z3HJ87Fzb-Yw9-3y8iPOhnykOYxmymCHgDaiPY744LVNunZHq8Amq5fBR6uKE2gileEoy8-zjTGflA3yC6kq5G2cWyemhGj1uJ2u47c-lY1qxTgxfOiX_q4N9e7LSn2rar0Y62B_PNrNFAirW1T5D1uDgJwuj65Hn9yJdaWW7xh8Cf6tOG679eNsutxsinpXptN2LYk2IOEyS9Y_A9IPD0enOMGWHK5g_lDyxg-L27korB4-_m-Oex09pIJJkPeFfFG48Y0mV5XP8N_5wXtzeLdHdQsNGyxtqiOPzXDhFGlbZlA3oopiAlMeUl3OYO-OV9WTHw0HrEXjn4DfPpy_oj-cBPZ4ePbBwCSzKgMX4R_48h3b0uuxlSc66-TyIYVbl0EWdAFmcsgDm4EeYkwwP423qz2LWGT2OijBiwZS46LEwSBIeiSyDMqgizHm4b5hcRvrCGPbNR8Loit8zMx3bxpCxGHuqpl-Jfbyt9DGBBrN8ReMTfCmI1xyAJ3oAIpnIJafkqBj36ChwfyU0iNOjL5Zh_E7regwlv1g0zyBRMduB9RJSFafhGnswv6a2Mg2nQETT5TVMFIj8F69haC7yYCKYnRKEOMD7vV-zt44Zt59BfjULiGcs8pO9SUSa4IH4L6mCi3Tc8WOzCUUF7m90_UunWFkDdhrD4JCY66ZhyidMfAuHBpTr3RL3mdOz5tpA3-8B8QPCQyunGiPOkSqumKxBYNH1PG1_2-eJdhYweejHALCcRQPP4Y-yU64baY73zti78SoblLFBdEMDmgRpkIU0yn21vwkEJDmjeVSljIT_wGMb_nOcFARRHserMBpVftf3SjzwZxpO_vu9ASZw3-nxs1pt5SMK-mM0q2sQW2l-2uBaqkppX4IUeLoXx4099ESC4uhtv_XT9xrHPmJxd1dcvcV3b6_x7uP79x__fPcfb_Du3fvrW3z3sR_e_PEGf7q--fjpbmjg3TzXBMxs3xl9qRH4NMEA7ttiIDBzA71Xynx6yc_XQZj01_r_ioC9_yW1_3vNH1u8F-IyEnmUswu4DNMkiuIoyoKL-8u4ytI4iEUZ-7G14DnPUg65iGiYcl5eyMvBSmkcpHEeB6s0TlIqeJhTWq0rnqM4gIbJeuXNa6XN4aLv8l6GSRBl8UXNSqht3_SnVMFX3H9FlKJke2Eue5ssu4NFcVBL6-xExklXwwt_CzDrly__CmDWZu8nMtuscPHU30frQNpb2bT1VC6tEV1jROn1Ywu8txU8zPjM6g7uvrWAaNi31NMxYqwuOlNf_n73e1TNwyX97wAAAP__JjP0iA">