<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/54195>54195</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            clang crashes at -Os and above: Assertion `Parent == Other->Parent && "cross-BB instruction order comparison"' failed 
        </td>
    </tr>

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

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

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

<pre>
    It appears to be a recent regression.

```
[519] % clangtk -v
clang version 15.0.0 (https://github.com/llvm/llvm-project.git 9c300c18a4eaf79eb7044744bbdb705764579220)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /local/suz-local/opfuzz/bin
Found candidate GCC installation: /usr/lib/gcc/i686-linux-gnu/8
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/6.5.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7.5.0
Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/8
Selected GCC installation: /usr/lib/gcc/x86_64-linux-gnu/7.5.0
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Candidate multilib: x32;@mx32
Selected multilib: .;@m64
[520] % 
[520] % clangtk -O1 small.c; ./a.out
[521] % 
[521] % clangtk -Os small.c
clang-15: /local/suz-local/software/clangbuild/llvm-project/llvm/lib/IR/Instruction.cpp:113: bool llvm::Instruction::comesBefore(const llvm::Instruction*) const: Assertion `Parent == Other->Parent && "cross-BB instruction order comparison"' failed.
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: /local/suz-local/software/local/clang-trunk/bin/clang-15 -cc1 -triple x86_64-unknown-linux-gnu -emit-obj --mrelax-relocations -disable-free -clear-ast-before-backend -main-file-name small.c -mrelocation-model static -mframe-pointer=none -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -mllvm -treat-scalable-fixed-error-as-warning -debugger-tuning=gdb -fcoverage-compilation-dir=/local/suz-local/software/emitesting/bugs/20220304-clangtk-m64-O3-mllvm-polly-build-065732/delta -resource-dir /local/suz-local/software/local/clang-trunk/lib/clang/15.0.0 -I /usr/local/include/csmith -I /local/suz-local/software/local/include -internal-isystem /local/suz-local/software/local/clang-trunk/lib/clang/15.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/7.5.0/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -Os -fdebug-compilation-dir=/local/suz-local/software/emitesting/bugs/20220304-clangtk-m64-O3-mllvm-polly-build-065732/delta -ferror-limit 19 -fgnuc-version=4.2.1 -fcolor-diagnostics -vectorize-loops -vectorize-slp -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/small-31cde7.o -x c small.c
1.      <eof> parser at end of file
2.      Optimizer
 #0 0x000055e048fcc0af PrintStackTraceSignalHandler(void*) Signals.cpp:0:0
 #1 0x000055e048fc986d SignalHandler(int) Signals.cpp:0:0
 #2 0x00007f2982c1b980 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x12980)
 #3 0x00007f29818cce87 raise /build/glibc-uZu3wS/glibc-2.27/signal/../sysdeps/unix/sysv/linux/raise.c:51:0
 #4 0x00007f29818ce7f1 abort /build/glibc-uZu3wS/glibc-2.27/stdlib/abort.c:81:0
 #5 0x00007f29818be3fa __assert_fail_base /build/glibc-uZu3wS/glibc-2.27/assert/assert.c:89:0
 #6 0x00007f29818be472 (/lib/x86_64-linux-gnu/libc.so.6+0x30472)
 #7 0x000055e0486a443c (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x31b943c)
 #8 0x000055e0480861ec llvm::RecurrenceDescriptor::isFirstOrderRecurrence(llvm::PHINode*, llvm::Loop*, llvm::MapVector<llvm::Instruction*, llvm::Instruction*, llvm::DenseMap<llvm::Instruction*, unsigned int, llvm::DenseMapInfo<llvm::Instruction*, void>, llvm::detail::DenseMapPair<llvm::Instruction*, unsigned int> >, std::vector<std::pair<llvm::Instruction*, llvm::Instruction*>, std::allocator<std::pair<llvm::Instruction*, llvm::Instruction*> > > >&, llvm::DominatorTree*) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x2b9b1ec)
 #9 0x000055e0492a0b22 llvm::LoopVectorizationLegality::canVectorizeInstrs() (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x3db5b22)
#10 0x000055e0492a21f6 llvm::LoopVectorizationLegality::canVectorize(bool) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x3db71f6)
#11 0x000055e0491fd5a3 llvm::LoopVectorizePass::processLoop(llvm::Loop*) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x3d125a3)
#12 0x000055e049200601 llvm::LoopVectorizePass::runImpl(llvm::Function&, llvm::ScalarEvolution&, llvm::LoopInfo&, llvm::TargetTransformInfo&, llvm::DominatorTree&, llvm::BlockFrequencyInfo&, llvm::TargetLibraryInfo*, llvm::DemandedBits&, llvm::AAResults&, llvm::AssumptionCache&, std::function<llvm::LoopAccessInfo const& (llvm::Loop&)>&, llvm::OptimizationRemarkEmitter&, llvm::ProfileSummaryInfo*) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x3d15601)
#13 0x000055e049200b99 llvm::LoopVectorizePass::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x3d15b99)
#14 0x000055e04a1f3471 llvm::detail::PassModel<llvm::Function, llvm::LoopVectorizePass, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Function> >::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x4d08471)
#15 0x000055e048731d7c llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function> >::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x3246d7c)
#16 0x000055e046bce721 llvm::detail::PassModel<llvm::Function, llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function> >, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Function> >::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x16e3721)
#17 0x000055e04873179a llvm::ModuleToFunctionPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x324679a)
#18 0x000055e046bcf081 llvm::detail::PassModel<llvm::Module, llvm::ModuleToFunctionPassAdaptor, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Module> >::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x16e4081)
#19 0x000055e04872ff54 llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module> >::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x3244f54)
#20 0x000055e049308dc0 (anonymous namespace)::EmitAssemblyHelper::RunOptimizationPipeline(clang::BackendAction, std::unique_ptr<llvm::raw_pwrite_stream, std::default_delete<llvm::raw_pwrite_stream> >&, std::unique_ptr<llvm::ToolOutputFile, std::default_delete<llvm::ToolOutputFile> >&) (.constprop.836) BackendUtil.cpp:0:0
#21 0x000055e04930bd92 clang::EmitBackendOutput(clang::DiagnosticsEngine&, clang::HeaderSearchOptions const&, clang::CodeGenOptions const&, clang::TargetOptions const&, clang::LangOptions const&, llvm::StringRef, llvm::Module*, clang::BackendAction, std::unique_ptr<llvm::raw_pwrite_stream, std::default_delete<llvm::raw_pwrite_stream> >) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x3e20d92)
#22 0x000055e04a0183fb clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x4b2d3fb)
#23 0x000055e04af23c89 clang::ParseAST(clang::Sema&, bool, bool) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x5a38c89)
#24 0x000055e04a016ef8 clang::CodeGenAction::ExecuteAction() (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x4b2bef8)
#25 0x000055e0499aea21 clang::FrontendAction::Execute() (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x44c3a21)
#26 0x000055e049948fca clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x445dfca)
#27 0x000055e049a7c873 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x4591873)
#28 0x000055e04690bc31 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x1420c31)
#29 0x000055e046907ac9 ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&) driver.cpp:0:0
#30 0x000055e04682dda9 main (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x1342da9)
#31 0x00007f29818afc87 __libc_start_main /build/glibc-uZu3wS/glibc-2.27/csu/../csu/libc-start.c:344:0
#32 0x000055e04690763a _start (/local/suz-local/software/local/clang-trunk/bin/clang-15+0x141c63a)
clang-15: error: unable to execute command: Aborted
clang-15: error: clang frontend command failed due to signal (use -v to see invocation)
clang version 15.0.0 (https://github.com/llvm/llvm-project.git 9c300c18a4eaf79eb7044744bbdb705764579220)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /local/suz-local/opfuzz/bin
clang-15: note: diagnostic msg: 
********************

PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang-15: note: diagnostic msg: /tmp/small-40dda2.c
clang-15: note: diagnostic msg: /tmp/small-40dda2.sh
clang-15: note: diagnostic msg: 

********************
[522] % 
[522] % cat small.c
int printf(const char *, ...);
int u;
void a() {
  char b;
  unsigned c;
  char d;
  long e;
  while (u) {
    char f;
    int g = 0;
  L:
    g = b = (d - e) / d;
    d = ~c & 6;
    c = -b;
    e = ~0 % c;
    if (!e)
      continue;
    printf("%d", c);
    goto L;
  }
}
int main() {
  a();
  return 0;
}
```

Compiler Explorer: https://godbolt.org/z/9KMKddv5G
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJztG9ly4zbya-QXFFW8jwc_yLI1dsWzdtlOUrUvKhAEJWYokguQPubrtxugJIKWj5nYW9nNpjwSBTT67kaD6KR19nR80RLaNJwKSdqapJxQIjjjVQtfK8GlLOpqOrFPJ_as_wzt_k__DE4CJ5kEp2TiBoSVtFq134h1r2fVb3LPBaIhTjC1pzYAxuu2beTEm03cBfytinbdpVNWb-BHWd5vv6xG1H9w1k4BgCTMs23mxNTnNI8Snka270e-n6YZPAZR6AdR4rr2xE007TsqVrwFIuQxDpehb3XVt6p-qKyyqLpHa1V1PdxacJqRTZ3xEqGbWhaPeuqiki0tS56dFgKnkK-a0RK-Zffd2j7XTd59_w4PaVHphYu6qzLCaJUVGW05-TKfk0Ijoy2ookfWSYEoixSVwBh8FmEcDhh0F_GfRNjLPkQZfgLKKZj249FGn4DyczjtzXTLS_BXnn0Ui_Mdc5uubAtcCIimE-9k4tub0H8NynN7MHh4BexxB_e4BdxJ8RpRDHyItj7wD43tksGVQ-QGNDFlgAMQuQs6rbt2sMY5gMd5jkfu8Oyzi-UEr4SmrPP2gQoOjwo67YoyG6WXQdJRhrm4wQ8wnugY2m7KmgZIOI6HhNK6LomCh_TlzQZwegCyGJcnPK-RaMxqmH8B3IX0lxAFgYhnUnKBEwSS6zXwDDl44p3CH7lq11xYE-9sO-yG8AdfLhO1lNbJiXK2HjGpRcYFIN40VBQSKbkTNyI5LSCV9cn8-vJsdntGZJduILlSknYryPhNLVrcB34sP2PekrLjEh4IOBkww8ou4wTYJkxQuSYpZd9aQRnoZE4aICRqBpsL-JisO6GHcSWVsmYFRecTXUUkE0XT9izftoCEZN0GraGHbJhKrkW9EnRDIN93G1CPfJ8_bIe0F4Hyqm99Ct-OOQGxGHMITBZNyV_cR4jFQYlWnf5BLGsjeEkfLfgE_GgOSayskDQtuZULzgFlCdutRWVrpcpNLFQOB-GtDS0qKwcrWRXd8K2zE4Wzx2apfYpAZmkLnMlBcm41dVG1HPao06qugES-oe3a4kJUNfzIGwu8DNUPjnYKDmLlVW0JTH8FiImwgEk5IrpQDcyVBZUcOM-76qGoMqtF_kGxpy5oQ22sFms61IgV-jDUVVwNrHjFhWIMHQQ1x2lrSdC0VkDxyDPkC2lICyxRAQegIA7-twIfB0QwAHRWWQrUWQ21A10BbnDmQqdS0CYK-raB0ShctogP7Nqt0D1dG0oEz_atPqlYkM-sK0-zC2osyydL5QjLDoMIEqK7AHW3lIBBtaci-Z_2Lp1g1Bh89_WQdTHYGvplfQQhsAQx1j3QO4lu489SXlHR0irkk2z55kMZf4vQQYleBX3PvuguptPnHwfAnxPkj_jAnhPea3uM5_XVP05CbWJWrvz9L-DUuQ7FssBNwElgAGRmVl-wA0P-1J06KhBLgMsKuqpqoM5AiHuOqaL4zoHNujEGZNnAGpplgAai-3S5hHpoeT777Wx5-vvsZuEu54uL5ez2K1AA7DWqqYW0DpJiyrM8h2U8mkLueiTM3PMdzPgTb87rHPZDAjsc7JqEtgQTaJ0TzJ4a0kXIq6YF2b5DalRjQMizif1ow39BwG0_zhmzaU6uBZhQbTB3uEvdFiuw5jnsSCUsdeP7usj6_VpPyb4osNW_HW5nhDuJw4yMkQGlNxG5PaIod5PYZU6axDZZLiEJgYr5UmANEO9C5oD3w0TTqpPNVNYYNif2owO49ucjJOMNyTgxYzyOiKCF5ES5ly6WVoCMWd0_O-_hdvfTnboRGkxJsQ1D8PqMN-iTkMcf9cC94gY4g2-FGsvAWeCYAvsjTniUO4SmtZL0fZy0mdaGWqWIxCMigUkk5V5OQatUVV5LrI-WKX2_7Hrd7kGTTEyS4ZikH7nvsB1Dq4XKahDYkWtYLTK8LKS-77Etzj9f82ii4HGA1SAbG2TtOHQ4G5S2N5x1AspTxk-5rttqoWcKuSiEbK-wLN1DAcP7xdfnF_-oMQPPsBLcj19Cank2-JU2v6lcA3ng5dJ6_krZPZw75ZXkgPINZF2Frs6xuG0PI7io8voNJCqPeGfm-oy34HkmrmtavCWdwRCkwh4vhIFecb9V0W6keRvpi3Mj5JCRsSD9SPxk8E8dcAwd15uiQnp3UEL3mfhjPd5NkxQc2vD4ZOjxiUvt1HVHzvlbv-mpXfySr6Bybp_6kyCttrNcSSsVxx_NuJelQeruMwRuQ_aIcdfJw59jHHjFE--nsB0BVwbbxvaZOHkWUO8Ftvk1JN3e7fRZUqeK-EDu-HjWHRc4M1h3TY3bdmg7b7MONC42TWmwDVtnHxWjGLjFU5Q4u6_L7uA80lA5aDyh34RCYVNJOG9uDsKMAmw0ewK6-bYQ_F8dZO6nV4hcFqmgood4lmg3UAPx7KSAI_p4-Qz2D9mVh2akhCM_SjynbL3lbZd08q26hokHVTFj6BXISf-ORb0xeeYfygMPZJy-clThcQOci29nUCTjIXsMeS1qrDpvu81mKPoneF0ATmV4nTf2ujRJ3uV17_O4GZR2T7KQX2kFh3Azt-8W9br7DHFBGkNcfygudXLPj5wXNlKU9qt-pX-I6WeBY6ppZF8O5d09z7Q6uPwpJalt7b9H_X5mx6BdQ_2BUQBGnpNFwwJQqfw1Vv8GavNcPwStGGoLh2oLUzjauB_htZ-n7v97vxNyD6xkmDEae3-U0OGhpM66kt_VW9bQPLOM7k9BY8H1gh8Su1_yib4LMhlCxyPfze34x3x3K-X8nar6KN_bqeplz_vLGQC8zgf9GgZITK9z8zzw35EEDqn9f01d4K8-aGOoLtc8-Hh2nDHVcECrunra1J0keLMiG3UTlWgusa7Dy7dNWj6d87LhfcDedNWwCLwuGl4WlbrVU-_BdWWs725mu5S7K0y7qoByedm0pk4EfVg2D6Jo-VLi7cjGWJTxnEIVvIQw4i1_Y6FxVn6L7h2c4q66tunaRaE94z1ER6sGFJU1p6qyhgNYM409Ndjr49e2KJ-_2UQLOSMLpVnikoFC0Ro9Ek3Y1Pfp_hX0WbVS5lDiD0DOOc24uOVUsPVVo6_gtieAEegc8tUXXr0BpY82bwBdwtMhkMH5rRVFtbrh-aFs2J-W_mKe9eEhy10b7G2ErHFyprYTe3l6QA9z0Gm32camfpuujrT6AuXXqhh5yuz2Dta0_LH9nAI5dTPg1BDFOI7R3PVYnAxFucbbCuDLZPQWTpe9s-hXLdvvj2Y5oF4MHBks-yPthzyPD0TIbNDhcPbIWdfyrWN-wist0G0KfBiMGoePJKGcQioZMLoQaOxdvAw5_RwefeZRs0R0Q5NHvAGipjLxwo8L1VeGr8AP6vNloT7Fj_0gAzYNOYxSN6ERg3LXyNGa47049313gsn9M3E_47WIHyQOsGfwb1atiZ0yD3yFOUtssDCKmpkQ9AlTsjdnayq2mXvWH4PMse0L_M8Qw_FdG7g0xEhGYkSUJWSr-7lzp5LEQJhbvCjVLzLUW8VDMikPykRxz8XB_dm8Hg1jN8toQlBvHy2w57uAeijw7vq0vyyjOTgeWS7xPgx2JiraZc_Iu67nmMTLNHUvqR_VpMKjruo83zdFd8f6Dj1KNOEPt7bDAPlO-GEnm7qSx4euwp4ZbMfi2ubY0oWvUHFyhpecPHtlue69zfsMsl3bd4GRrFOY9fUtStdJTqx7NcY5KQYhPeTxb9jLO1RuVWPpNCP7RgiykSuFrveiP_E3aLLuu_Nmd3ez-Tm5Oz8ji6vLy6vfL_7xhSwuLs9uyd2VGj759Qu5Obu-urlDC-i1h7rrYolx_2KH3Q5AcKIu9mCWtjuU71SB2cTh25A63EO9mj-KQq5_whIfZQ9sRXUPtKfuxkBbZotKUbWkwX6SfNcAqvJwv4VMMSMl2E27g-52v3B_IXRbsET9KNEI0h0Y2d_-ssGggsoGA2UNIcsHAw9riH4V7iMC_eJ8AEvwZpmssAmV2IPxy51fIIyeT9Un4M2IRbjeHhcGK4RkGiY6w2aFkITGJFOTVmoM8u0KW2vaZC7XSdnh-ztb9R_2OkJa4Ab0ziCqGTbI1Bds8ENTKHFqyICXg6FJdNpbffuAWukLiZESe8MNVgvedqIaqG-PbvT_UegW7b5igl2-KWuhTjvjZtw6S-uyndYCO8AwUyW_fP0ly-6DL0fZsZclXkKP2qIt-bHO2KoBl0vskcLmM5UD0vpeRc9_qOeYHHWiPP75puLAd5LgaH2cMJYw6uYRVKS5DacVRrFVKA44d9KIRkclTXkpjyFAgX7FH4hCMVHBelQcbxvl7AQ-nGnGmJ9lScgCFnhxHk58G45iRTlFPlDBR-JYsaT67Hy7LGQr95OQSTEEuSIH-GnXrmtx_H0N2y3EneyOFPVjxf2_AWTjzYs">