<table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Issue</th>
<td>
<a href=https://github.com/llvm/llvm-project/issues/69777>69777</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>
Clang: Assertion `isReg() && "Wrong MachineOperand accessor"' failed.
</td>
</tr>
<tr>
<th>Labels</th>
<td>
clang
</td>
</tr>
<tr>
<th>Assignees</th>
<td>
</td>
</tr>
<tr>
<th>Reporter</th>
<td>
shao-hua-li
</td>
</tr>
</table>
<pre>
Clang at -O2 crashed.
Bisected to 760e7d00d142ba85fcf48c00e0acc14a355da7c3, which was committed by @weiguozhi
Compiler explorer: https://godbolt.org/z/sMW5hr1a9
```console
% cat a.c
long a;
char b;
static char *c = &b;
int d, e;
int *f;
long g(long h[]) {
h[1] += h[1];
return h[1];
}
static int *n();
static int *o() {
int i[1][6][1];
int j;
d = 0;
for (; d < 3; d++) {
e = 0;
for (; e < 6; e++) {
j = 0;
for (; (8 << a) + 6 + j < 1; j++) {
long k[] = {3, 61};
long l = g(k);
i[0][*c + e - 23][(int)(l + *c + 2955120606988730223) + j] = 7;
}
}
char **m[2] = {&c, &c};
}
return i[0][0];
}
void p() { n(); }
int *n() {
b = 23;
f = o();
return 0;
}
int main() {}
% clang -O2 a.c
a.c:27:14: warning: address of stack memory associated with local variable 'i' returned [-Wreturn-stack-address]
27 | return i[0][0];
| ^
clang-18: /tmp/tmp4rmktvza/llvm/include/llvm/CodeGen/MachineOperand.h:375: unsigned int llvm::MachineOperand::getSubReg() const: Assertion `isReg() && "Wrong MachineOperand accessor"' 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: /zdata/shaoli/compilers/ccbuilder-compilers/clang-08d7d1ef9a1049b0fb97c2c0999f3b42c08edd40/bin/clang-18 -cc1 -triple x86_64-unknown-linux-gnu -emit-obj -dumpdir a- -disable-free -clear-ast-before-backend -main-file-name a.c -mrelocation-model pic -pic-level 2 -pic-is-pie -mframe-pointer=none -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=/zdata/shaoli/realsmith/watchdir/reduced/case_mksSyAd1 -fcoverage-compilation-dir=/zdata/shaoli/realsmith/watchdir/reduced/case_mksSyAd1 -resource-dir /zdata/shaoli/compilers/ccbuilder-compilers/clang-08d7d1ef9a1049b0fb97c2c0999f3b42c08edd40/lib/clang/18 -internal-isystem /zdata/shaoli/compilers/ccbuilder-compilers/clang-08d7d1ef9a1049b0fb97c2c0999f3b42c08edd40/lib/clang/18/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 -O2 -ferror-limit 19 -fgnuc-version=4.2.1 -fcolor-diagnostics -vectorize-loops -vectorize-slp -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/a-dfec10.o -x c a.c
1. <eof> parser at end of file
2. Code generation
3. Running pass 'Function Pass Manager' on module 'a.c'.
4. Running pass 'Peephole Optimizations' on function '@p'
#0 0x00007fa9a1ed2ecf llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-08d7d1ef9a1049b0fb97c2c0999f3b42c08edd40/bin/../lib/libLLVM-18git.so+0x927ecf)
#1 0x00007fa9a1ed0434 SignalHandler(int) Signals.cpp:0:0
#2 0x00007fa9a11c0090 (/lib/x86_64-linux-gnu/libc.so.6+0x43090)
#3 0x00007fa9a11c000b raise /build/glibc-BHL3KM/glibc-2.31/signal/../sysdeps/unix/sysv/linux/raise.c:51:1
#4 0x00007fa9a119f859 abort /build/glibc-BHL3KM/glibc-2.31/stdlib/abort.c:81:7
#5 0x00007fa9a119f729 get_sysdep_segment_value /build/glibc-BHL3KM/glibc-2.31/intl/loadmsgcat.c:509:8
#6 0x00007fa9a119f729 _nl_load_domain /build/glibc-BHL3KM/glibc-2.31/intl/loadmsgcat.c:970:34
#7 0x00007fa9a11b0fd6 (/lib/x86_64-linux-gnu/libc.so.6+0x33fd6)
#8 0x00007fa9a25b7df5 (anonymous namespace)::PeepholeOptimizer::foldRedundantCopy(llvm::MachineInstr&, llvm::DenseMap<llvm::TargetInstrInfo::RegSubRegPair, llvm::MachineInstr*, llvm::DenseMapInfo<llvm::TargetInstrInfo::RegSubRegPair, void>, llvm::detail::DenseMapPair<llvm::TargetInstrInfo::RegSubRegPair, llvm::MachineInstr*>>&, llvm::SmallPtrSetImpl<llvm::MachineInstr*>&) (.isra.0) PeepholeOptimizer.cpp:0:0
#9 0x00007fa9a25b86ee (anonymous namespace)::PeepholeOptimizer::runOnMachineFunction(llvm::MachineFunction&) (.part.0) PeepholeOptimizer.cpp:0:0
#10 0x00007fa9a243b301 llvm::MachineFunctionPass::runOnFunction(llvm::Function&) (.part.0) MachineFunctionPass.cpp:0:0
#11 0x00007fa9a209ac81 llvm::FPPassManager::runOnFunction(llvm::Function&) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-08d7d1ef9a1049b0fb97c2c0999f3b42c08edd40/bin/../lib/libLLVM-18git.so+0xaefc81)
#12 0x00007fa9a209aec9 llvm::FPPassManager::runOnModule(llvm::Module&) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-08d7d1ef9a1049b0fb97c2c0999f3b42c08edd40/bin/../lib/libLLVM-18git.so+0xaefec9)
#13 0x00007fa9a209b752 llvm::legacy::PassManagerImpl::run(llvm::Module&) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-08d7d1ef9a1049b0fb97c2c0999f3b42c08edd40/bin/../lib/libLLVM-18git.so+0xaf0752)
#14 0x00007fa9a880c14a (anonymous namespace)::EmitAssemblyHelper::EmitAssembly(clang::BackendAction, std::unique_ptr<llvm::raw_pwrite_stream, std::default_delete<llvm::raw_pwrite_stream>>) BackendUtil.cpp:0:0
#15 0x00007fa9a880c629 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>>) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-08d7d1ef9a1049b0fb97c2c0999f3b42c08edd40/bin/../lib/libclang-cpp.so.18git+0x20a3629)
#16 0x00007fa9a8ccd0b7 clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-08d7d1ef9a1049b0fb97c2c0999f3b42c08edd40/bin/../lib/libclang-cpp.so.18git+0x25640b7)
#17 0x00007fa9a71e55f9 clang::ParseAST(clang::Sema&, bool, bool) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-08d7d1ef9a1049b0fb97c2c0999f3b42c08edd40/bin/../lib/libclang-cpp.so.18git+0xa7c5f9)
#18 0x00007fa9a8ccc298 clang::CodeGenAction::ExecuteAction() (/zdata/shaoli/compilers/ccbuilder-compilers/clang-08d7d1ef9a1049b0fb97c2c0999f3b42c08edd40/bin/../lib/libclang-cpp.so.18git+0x2563298)
#19 0x00007fa9a99669b9 clang::FrontendAction::Execute() (/zdata/shaoli/compilers/ccbuilder-compilers/clang-08d7d1ef9a1049b0fb97c2c0999f3b42c08edd40/bin/../lib/libclang-cpp.so.18git+0x31fd9b9)
#20 0x00007fa9a98e242e clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-08d7d1ef9a1049b0fb97c2c0999f3b42c08edd40/bin/../lib/libclang-cpp.so.18git+0x317942e)
#21 0x00007fa9a99ff566 clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-08d7d1ef9a1049b0fb97c2c0999f3b42c08edd40/bin/../lib/libclang-cpp.so.18git+0x3296566)
#22 0x000055d031d26aa6 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-08d7d1ef9a1049b0fb97c2c0999f3b42c08edd40/bin/clang-18+0x15aa6)
#23 0x000055d031d1e3da ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&) driver.cpp:0:0
#24 0x000055d031d2301c clang_main(int, char**, llvm::ToolContext const&) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-08d7d1ef9a1049b0fb97c2c0999f3b42c08edd40/bin/clang-18+0x1201c)
#25 0x000055d031d1de55 main (/zdata/shaoli/compilers/ccbuilder-compilers/clang-08d7d1ef9a1049b0fb97c2c0999f3b42c08edd40/bin/clang-18+0xce55)
#26 0x00007fa9a11a1083 __libc_start_main /build/glibc-BHL3KM/glibc-2.31/csu/../csu/libc-start.c:342:3
#27 0x000055d031d1de9e _start (/zdata/shaoli/compilers/ccbuilder-compilers/clang-08d7d1ef9a1049b0fb97c2c0999f3b42c08edd40/bin/clang-18+0xce9e)
clang: error: unable to execute command: Aborted
clang: error: clang frontend command failed due to signal (use -v to see invocation)
clang version 18.0.0 (https://github.com/llvm/llvm-project.git 08d7d1ef9a1049b0fb97c2c0999f3b42c08edd40)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /zdata/shaoli/compilers/ccbuilder-compilers/clang-08d7d1ef9a1049b0fb97c2c0999f3b42c08edd40/bin
clang: note: diagnostic msg:
********************
PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT:
Preprocessed source(s) and associated run script(s) are located at:
clang: note: diagnostic msg: /tmp/a-cf9380.c
clang: note: diagnostic msg: /tmp/a-cf9380.sh
clang: note: diagnostic msg:
********************
%
```
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJzUetly2ziX8NPANyiqSHC_8IUsW53Un_x22e7OpQoEDikkJMABQC95-imA1EJZ-ZL09HQyKUcSD4CzbyBAjRGNBLhE6RVKry_oYLdKX5otVcF2oEErLirFXy9XLZUNphYHtwQzTc0W-AKF1yhcjp9XwgCzwLFVOM9CyHkY8ighFS3SmtVJwcIQQspYlNA4TTnNWYzICj9vBdviZ2owU10nrENRvWKUhM8gmkF93Qp8TGelul60oDG89K3SoFG8xFtre4PiJSJrRNaN4pVq7ULpBpH1V0TW5uOndKsjWh5jQlk4_jEljWphgpIUM2oxXbAR0ConOIqvxke2pRpX-0djqRUMeygiS4ZRfI0RyQ4zhLSYO0lhBkJkWe8BnkaDSOF_bEdbIFJilE8zsIdGKHXYrxyR3fMeCcYa7KDl2xGUX8-4nehLRApEylNZplE1jh6z4EbEDnl6lY1fJ0y4SZ-PnrlXSXiA1MqpqkDxlR9b4dj_dGK5vxlFjOF0OcbHGMBjyPzPb2DA-PMZHDMsiBSFQ-RwUY-AXOHMf372BCI36_M3CWDsDfdlNNzoA_mV9-8sctqPz01v_URn9i_HZtjNcZoORxWPnkWcuAEm8Q5YCGndSlK0fnQ_jZRpGpEwC7OyKPI4JCTeSfV5x2B-QnDvJG8eds6NyLJD6RU5EhGRjDkp_fdMziMMk1seyROe9c4nJTjuD26HDw56QDf33SNDVJ4nEh_xUHuQOnHzPUPhWxYc9o6KY-y7IZ8YfBZ0KXCfHtyPeElyFC-jxOWiZ6qlkI37STnXYAxWNTaWsi-4g07pV0yNUUxQl-qehd3iVjHa4ieqBa1awIjkApF8YhM4RulV8Gl8CjyiYMLs1LgzE8kxyleT73xH5TuL76ZP_1B6MyU5J2cQFU4IRNa268fPRHdf7NNXisi6bZ86RNZCsnbgcACsFIc_QCKy_kjZVki47UFTyRdbFC_jPHUoB-mLDve5wq-LlyhezheMsAbsw1DdQzNZxOVq63AsjQFthZIYZaEwhxmIZIi42CWftIuyOVZMGQNjlEaEOB3XVLT7Snb34Wb5cIPNUHXCYoqrocEaeqWtq2onRUbY7VAtmOoOsruvoNfqMzDrdGPMAAaRNXaEJ01hu4WxgOKKsi9WUwYugnoNvVaON-DYqEGPYM_ywV30ILFhWvR2YvnB-xUfut5x5kHhAt9p1WjaYaqboQNpzWTIr5xaZzxX3luByJpN1dRxyVg1iJaDDmZQ7wphwXMeQV3SKEzKKqyrMmeEhWVZ1nGVEBYWwHkSIrKuXPSsdx6EA8YiHFgt-hbwS5FtsiQY5BepnmXQCjm8BI0ccACdsIGqPuPAycKFxjTAARfGRURQawAcsBaoDqixQQW10hA4BYLkOHAhG9SihUDSDlxw4qDT4OLKuUjQKQ4t7gXDQS9Y0MITtJiMD8IEvQAcdLWmHQS9EtK6ruJaKgk4qDtqtwFoLRUO6roPmJLOaBbF10rioJYq0GqQXMgmcHNx0Hkn1QOzSge0FdSAwUE9yGcheWCdRAbF1wQHluoGbMD6wakmyBIc2EGCBzQgQTuOOVRD04B2Qz6xXDe8wkHt4ZOtRjG5cHyfs7MG2ppO2C0i62dq2dZNdWA-MODOXtTApvtiHl6XPMJBzdQTaNrA_xJ-DaOLO5T_lmO2ototQ2TtXNNbWtI2EObVWOh-FSeHPHqep8E4Zfoq8YNTPYGGMUTWU8ztY81RjBBZLxZvP87MfUsNXtwP9pbqoRac4vnPq3-ehC_BQQ1aKx20wmXrqMRB3ciBBU-gjVASxdfJgixGZ26VDrigjVTGCmZw8AQuOsVXCFql-hnAtD0OaldhjWhwcL3Z_LFabd4t_7rZXH9a3q_JZrV-v1k-fETxdYQDdaiQNOA1sChcKBy8YHZoEqLFVGDjFagaxTe4p9qAdhsql8BUjV32GieTabKrpGMW8NE3DsYLfD9IlwdwT41xvcJ6kMwXwjsH-EglbUC72qYk7hQfxo7C8ULyqWokE4lTVHcA_Va1gG97Kzrx1RM2E656RweRHCVh777GbgKROMThSxiGYV7TkkbACbD6qLSbVzP-uNNCWl-0HsfKVxwmafq8UcZqoJ0v4is89re-S_83i5ePhTGGWlF9-PDXxyAqGmEXRiFyFb6UJAdWu55yL390In-YxAl-EI2k7TsqeessMrXrE9gsWO-Kduj_7xGRGaKIhWEZTgoYOToTo62o2MKoRea5S-KwDGfMxW9whhXWVBjnGWuvOJcuHJrg6t2H-P993D-SReyShfEs71RjXg2H3il4kOJlBDx5PuTgHj1q3xenkeuLD5wkc07KukhLTCvXYf0oJ5aPevCrPJHCETnyxfSUSE5K3IDdjHxvDDSuKdo80Xb4YQ0IaVufhCnvTMPoSDoNS8fAgXZ2jvZGthu3cMOV61T-ZyTL3HlMnBxo5nOaVVjz7OdcJo5rns1cpjjGSdIq53XqcFKp5GunBoNdp2V6H8PlFNtT9piSh381g-JlrVp-D3yQnEq7Uv3rLOin9vy965imqD8MXoM08JH2KF4dgI--afIL3stajcB7aMZ9wh11ncfq7bZiorA8T2HE9NNU3JYVxTdznBwsFe0cv1_wT0oR33i6Jwp76Gjb3ln9APZ917czimcwuOU-vS6E0XThsgZ-Y8Xzeao8cZAiA_ibDqIHeSsn7nbF7JyPHMb2bPdU2x9m26XpWZ0iSVzFYfRWyztKrqIe8XiWuf_I1Rl85_ma1Q8SlpQVx3yt79zSXW3_aY5-q-pJoWZFtM82TnpyKj2w8gek_-i7m7mrTKDfVXJg5Uzy-ETyKk_JkeQtNJS9TtFz0MEY25Me_g_JX4d5SmbyzxqCoghZlNDvpZGbTtilMdBV7es7aPudTxzDESnG_ZUfuRpfFCynsFhhY6f3S4MU_zXAprfz7Oxa0f5ZCwubXUN6tIhDTYfWbji0YOE7C6dEXeKJiT-taM_ngPRUFxkp8ZEUTr4Jye1g-8HOhbw-7G9uZCMkTNXhaMo7oBz0A1DNti5RKmmmN2pvpk7v8b4za6xi35n0gcrm3JSjsmW1kM091Cc1b3Lm5QnCN-Y8LHkvrR6MeIJ7qFfS3p3Y9ame8vlatPDgN5dT-f4VHvFr43NEwvre9YE-Tn2QkpDGGZlnqVlXWzDGwyo_Y5CVkmboduE47nseNZVmfH_0pxQnLrt8eFwpaeHF_hYZ61saSbMkrPKZRmY9dx5BmtazWL1z-_vlw-Nc3gfo6OT8lVLt4fs3lZzmLK3nrlCcuAIjZXEmb0yxOeatF2CDhV24Fr-tuCTNYlIWM3lnfW5ZZllZzQy91s6B98noWODfWdQ4qnlZzUxLZr1xWQBJCMxNO_LmdhBUMjhv3W_r5jcO8TjKy4TATB3R3PJ1nWbZrByPgh-08jQdN8yV8EZrrpz9rmogZZZm2UwNu948TXkYR5xklGaYsWgznZMeKt1Sa_rqini88kfGU61fThV2Dtttnn-NNvYHnE7qKKV0LnM8lzmCmFO8s_cqevQ5uzjZdv_l3yBP2-63CjhpeRyOqfYdNUUl5lo8fWPzSpITU8RhxEaP3BnDv2EcVT0e2P8Y0V-rfhJGbKb-9ET9HNIUT2_OfiGjDNJ0xufJyz4ahUWMNxsXXxtjqbabn3ndx8ywi9Pxpx_0ePyLvzgh7vNAPn-jphLwSPhXK6o8pNJdKsT-tGY8_vfXHKzCMIaUv_o1HvnjZaW0Bf6tteMNjHoqLLuF0zE-5oNHO76tdjoYDODgycMAsDhK0cfc4enICEfFIlz41-0_d9i_aITFP66zifa4eXJSfetcfJq31UA59ofYbnavjHgZh3xRaVvg10L_y2f8cwNJ5bY9S3w4ZMOdafZ3EnbJ6G_9Hd3Zm25oLB8fl6t3-PHdDV7ffvhw--n9__8Dr99_uHnAj7cefPXnH_j-5u72_nHPw925GxaFcfnvm7cs9hM0-Fs6bpTaPcrvi398OMjqMi7C3Zng31prtj-p939K-yQ9uTR5wS9jXsYlvYDLKCvzIk7SglxsL5OYcVYlYZqSuqoLkuZlEZGQFEXOgGf1hbgkIYmjkIQkTOKQLOqchZyGNC7yJCFFhpIQOirahQuxhdLNhb9Jc5mVeZ5ftLSC1vj7qoRMZ-gEpdcX-tKHZDU0BiVhK4w1BwxW2BbGW6z__O2hi0G3l3__epCX678DAAD__3EyHvg">