<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/118247>118247</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            clang crashes on x86_64-linux-gnu: Assertion `i == DstIdx || !MI->getOperand(i).isReg() || MI->getOperand(i).getReg() != RegA' failed
        </td>
    </tr>

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

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

    <tr>
      <th>Reporter</th>
      <td>
          bi6c
      </td>
    </tr>
</table>

<pre>
    Compiler Expoloer: https://godbolt.org/z/zc6exovje

```console
clang: /root/llvm-project/llvm/lib/CodeGen/TwoAddressInstructionPass.cpp:1594: void {anonymous}::TwoAddressInstructionImpl::processTiedPairs(llvm::MachineInstr*, {anonymous}::TwoAddressInstructionImpl::TiedPairList&, unsigned int&): Assertion `i == DstIdx || !MI->getOperand(i).isReg() || MI->getOperand(i).getReg() != RegA' 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: /opt/compiler-explorer/clang-assertions-trunk/bin/clang -gdwarf-4 -g -o /app/output.s -mllvm --x86-asm-syntax=intel -fno-verbose-asm -S --gcc-toolchain=/opt/compiler-explorer/gcc-snapshot -fcolor-diagnostics -fno-crash-diagnostics <source>
1.      <eof> parser at end of file
2.      Code generation
3.      Running pass 'Function Pass Manager' on module '<source>'.
4.      Running pass 'Two-Address instruction pass' on function '@foo'
 #0 0x0000000003bf5af8 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x3bf5af8)
 #1 0x0000000003bf37fc llvm::sys::CleanupOnSignal(unsigned long) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x3bf37fc)
 #2 0x0000000003b40ee8 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0
 #3 0x0000789338a42520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #4 0x0000789338a969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
 #5 0x0000789338a42476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
 #6 0x0000789338a287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
 #7 0x0000789338a2871b (/lib/x86_64-linux-gnu/libc.so.6+0x2871b)
 #8 0x0000789338a39e96 (/lib/x86_64-linux-gnu/libc.so.6+0x39e96)
 #9 0x00000000032486e7 (anonymous namespace)::TwoAddressInstructionImpl::processTiedPairs(llvm::MachineInstr*, llvm::SmallVector<std::pair<unsigned int, unsigned int>, 4u>&, unsigned int&) TwoAddressInstructionPass.cpp:0:0
#10 0x0000000003249e7d (anonymous namespace)::TwoAddressInstructionImpl::run() TwoAddressInstructionPass.cpp:0:0
#11 0x000000000324c35c (anonymous namespace)::TwoAddressInstructionLegacyPass::runOnMachineFunction(llvm::MachineFunction&) TwoAddressInstructionPass.cpp:0:0
#12 0x0000000002f4c5e9 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (.part.0) MachineFunctionPass.cpp:0:0
#13 0x0000000003552800 llvm::FPPassManager::runOnFunction(llvm::Function&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x3552800)
#14 0x0000000003552bb1 llvm::FPPassManager::runOnModule(llvm::Module&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x3552bb1)
#15 0x0000000003553467 llvm::legacy::PassManagerImpl::run(llvm::Module&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x3553467)
#16 0x0000000003ea6ac5 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-assertions-trunk/bin/clang+0x3ea6ac5)
#17 0x0000000004578bbe clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x4578bbe)
#18 0x000000000651c9ec clang::ParseAST(clang::Sema&, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x651c9ec)
#19 0x0000000004578f98 clang::CodeGenAction::ExecuteAction() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x4578f98)
#20 0x0000000004833eb9 clang::FrontendAction::Execute() (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x4833eb9)
#21 0x00000000047b3dce clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x47b3dce)
#22 0x000000000491edde clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x491edde)
#23 0x0000000000caf871 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0xcaf871)
#24 0x0000000000ca73fa ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#25 0x00000000045bc1f9 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
#26 0x0000000003b41394 llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x3b41394)
#27 0x00000000045bc7ef 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
#28 0x0000000004582a7d clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x4582a7d)
#29 0x0000000004583b6d clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&, bool) const (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x4583b6d)
#30 0x000000000458af25 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0x458af25)
#31 0x0000000000cac6a3 clang_main(int, char**, llvm::ToolContext const&) (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0xcac6a3)
#32 0x0000000000b7fe54 main (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0xb7fe54)
#33 0x0000789338a29d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#34 0x0000789338a29e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#35 0x0000000000ca6eae _start (/opt/compiler-explorer/clang-assertions-trunk/bin/clang+0xca6eae)
clang: error: clang frontend command failed with exit code 134 (use -v to see invocation)
Compiler returned: 134
```
Code:
```c
extern void abort (void);

void
__attribute__((noinline))
foo (unsigned int *y)
{
 unsigned int c0, c1, c2, d0, d1, d2;
   d0 = 0; d1 = 0; d2 = 0; c0 = c1 = c2 = 0;

   __asm__ ("movl $7, %k0; movl $8, %k1; movl $9, %k2"
 : "+r" (d0), "+r" (d1), "+r" (d2));
   __asm__ ("movl %3, %0; movl %4, %1; movl %5, %2"
            : "+d" (c0), "+d" (c1), "+d" (c2), "+d" (d0), "+d" (d1), "+d" (d2));
   y[0] = c0;
   y[1] = c1;
 y[2] = c2;
}

int
main (void)
{
  unsigned int y[3];
  foo (y);
  if (y[0] != 7 || y[1] != 8 || y[2] != 9)
    abort ();
  return 0;
}
```
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJzkWl9vq7i2_zTui5UIDAR46ANN2zt7tLd21fbe18iYBfGU2FzbdKfn0x_ZQPjTdM90JjM60qnahizbyz-v_7ahWvNKAFyj6AZFt1e0NXuprnO-YVe5LN6ut_LQ8BoUvjs2spagUJDhvTGNRkGGyD0i95UsclmbtVQVIvf_sn9sA0f5-hsgL7O_G6_7ZVJoWVsqq6moLCtE7pWUBpH7un49rBolfwM2fLUfPEfkfisL-B8QiNw__5BZUSjQ-ovQRrXMcCkeqNZr1jQoyPwoDS3fV8kLjOIbKqR4O8hWo_jWIg6ysxy-HJq6a26UZKD1M4figXKlEUkcFNf4jbI9F-AGIpIhsv1TcwzMv3JtENlYNq1wiigwFx0ptavItAZlx2K08ThGwS0KbvGtNl-KI0bxFsVbjIj_7csKBXcVmO8NKCoKRBKOSLrm-hEqRBJE0qH3R10rMJO-xLfzPEKVIRLjkvIaijXysoevd9nTHdZtfuAGU5y3FVbQSGWwkUuz4Gbf5msmDxNtznXMtW5BI3KPqbArZ3VbADZ7wExRvcc5ZS9GUQZWQo2CXjdQYC1b1ZHtSKq1ZJwaKLBqBdZM8cZYvE-GshdctAdrGsjLvDXy0gclK0UPmKqqPYAwurdD2VhMrDf4FRybWipQlmatdUUHZeiVUa14QeQ-52Joxquq-EFVuQrxqsIraTnSprF8W9O0Zq3x6mDXj1erY7JZUX1Y6Tdh6BEFt1wYqPGqFHL1CiqXGmw7Xj3h1apibGWkrNmecmEt4GdIbWctaKP30uBVyWQt1argtBJSG850N4eT7oyMgm0v0uAOeZlv5YSCLcgSBXe4oUqDwtRgEAWWJS6582Jiu1nfxBUIUNQKB3lZYMmPrRBcVLihWmNE4vtWOC_A1lnxNypoZRHHWAp8kEVbg-01w0Fiq8PwHLfnH3LVexjmo4u59p5pOUxo2YZeKaV98KyqAw97R2_4CfIyomWCRzfXb7p7eFBcGGdEz50ZTmKBoj92UhsF9ND7sHNd6z3JX7YmRG68Yw_MxoIOtr-AHcQlOwd7WwMVbfNdPPFK0BqR5BReammZXxakhTGCJHOQoQeQ4K21uEdg8hXUW4fqFyqK2s6V9HKb9dlKYeBo-qjuub-Of9Dzj5M0CBIakoh4_XK6ZHFMNrtNuKq5aI-rSrRdA1trud44yG7ICDicM0w3aclwY_YKaLF74XX9Oe5u_Mg9WsIN4w2utBPBZ2GH8WZkvJkzJklcBpjmNhZ_iq0bOLKN37H1808z9PORYTJnGKSQbj7H0A0ZGaYzAyNhsoHYMjylYSzoAXTjHDb9W5L-2Ph0oHX9f8CMVDZ2maJnSLn9Ps_qiyxvI9wWh617-KAIwL9X7wyeYaODtxBMCnHxFwWjWtHXBJ8B4i-AsCBifwrIV6goe7OznOB8F70-hoRyTldj26eFOAtfpAxZBCn-cIIFtLOYFmAQSdYNVWZtQxA-w-8MqGAm0CgiiedNQN0_2HFDTv00nAslgg5W56cWdLgEnef-HwD9zRUDc632pMsDznN_BBwtAAfhJp4Arp0x9oXBCH3pLP8AbAtshL2ZwQa6oSzCwwYLBdndgZsbyl5AFN9dKYpIMmm-HcvAO1FxAX0wmnT5BWgB6gmoYvvvjYOH7V7OvO_a79R-p9czVW4L8tNOX6moznWZBF-juKgeoZyTB7lnC4a9ELLe_KdDvgijWs1f4RHKrTAPxkbvsfm17L38ntfw9KYNHPrwfYr4reD_38KuWYy0VWLzQ3EDu6FWnAwqoKRtbXYF1GDgdwYGd_2c75e0lUK3B-jS0yVtrbOm0dbiqa2FUZzkOfwMT2c-rtJ7VlTo2u0R_lfwhRFmT899xXdpd-lBjktIpkvYRD5LgU2X8GA3O9nT8xzgExxob3-5lPX4eUGoPZgRarqUdpkmZ5ytN-jO2Y_AWgODjScXl2WZJieAZFZxhEkQQJ5OAd4rq9STy00RXhxbN_uIbVaEhHEeFAzmwutmsyUBFXbHeU5-Hy_m0nbaIRzxzwqRMPWhKGb4e6TjMl4lo-9Rv1vmhUNEj2zEPatVPEbLJPYxY_7uQPk8P2ZK0TcbvYMt21M1BPlsCHMzGtm6M71Lw-_wjejDBfo4KCkeRL31n53PJ2fr_64QOLOURdayPPpgN8lrKS4UfwX1vvoj0TwM5Mwv0-6Ac2Q6nHbslJNnd_zpXMzlDduF0brOKXvZlcLCHE2km7g3l62_lYcDFcXSW8_q7ZTJpEvUtJ7lsDE_n3LXacBux45H3---5FRzZvMct5icCGedLWFnFOVGD80LdrSurfm7XdjQbrtkY6R2htMJ3A1BJK7pIS8oIvEoKpIMRyS_yvyMMjaL4w0_SMOJHs4dYnQtj614oiXUbzNZ_lxvlz2ocVhHU4-XZhVDif-bzWKxNTuv_2QutYTQuPhQak5f9F3uG0Q5C9SLgbbDR5XxT7pmsyJlsrBLVQBuwaMRLUqUJMg3nxbHrzLXH8viV5l_5dp8tAV4F3-XZzD90csfFV9vIH-zEK2YTkKcH0eHUUJLEn0E-HbyPCsBzuT-j4T_DwrxotWnE8woNn-Rq9mGBh3EodYYYLvAkb07vPsoE1-wurCYRsSzms7L4xKiEFusl5uyYzpOuTguJ2mRfvK43A0ZGYZLhhB6eLezY3baUGV2kwX94SkgnEwRLRS7AQq4Y35J3Vi23aSn62hQSror7u5Or-xLfsx6C--uQvEPbvYYjtyaTQHYD0KLq9WAV6_YSKwBMJ8U5HaO0026AtMqAdbB7MjpBbnrVkB3WTlemyMvg6MBJbqq73TI3xXEKQpuuot2993LdjtqjOJ5a2C3c_JKhOSidmc7_Q6plBJP74W4sByzt14JseU4O4_GzHOu5Lv_xP4vHKVwlIJ0KDDGhYdRcIs9FNzgwp88k_GZdX1Y18zGlm4hGOPdjurDbtfpmxzka40RCWN35U6iF8dloCYD1Z9S04FKECHu7sDd8xJEbhQixHIunNG5bjOyf55MevENKz2LMQr6eacQrUc64hRhFPXEAeDkZ8Ra9LOzOdYT2T9PJmfJxXkmxXkm7xb8hqIbD0W3nda8Gd0_0f2ebqnkRO0NBMW3nY5tbPayIVYMpnyyvbnxWVYBim6HGXvzfZuA42VHGRB27zDEw4sPI8SuIZk2kElD7yBWCZPbtNM0nfeebLVbzeCpV8V1UKRBSq_g2o-DwPejICVX--tNXJAkSMPYLyPCUivaggTU88s4CHLKrvg18UjoE494YbQJyNpPc2pjLPFjjwVRikIPDpTXa5u-1lJVV-7tiWvfT0gYX9U0h1q713gI6YOcXdWVunYvXeRtpVHo1VwbPbIw3NRw3cU691IAaCwFfhev_8NeRblqVX3959826UX2ek3-HQAA__-SPy-V">