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<base href="https://bugs.llvm.org/">
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<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - [AVX512] Crash in LiveVariables"
href="https://bugs.llvm.org/show_bug.cgi?id=37430">37430</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>[AVX512] Crash in LiveVariables
</td>
</tr>
<tr>
<th>Product</th>
<td>libraries
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>All
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>Backend: X86
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>keno@alumni.harvard.edu
</td>
</tr>
<tr>
<th>CC</th>
<td>craig.topper@gmail.com, guy.blank@intel.com, llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>Consider the following bugpoint-reduced IR:
```
define void @"julia_#3_33548"() {
top:
br i1 undef, label %L19, label %L15
L15: ; preds = %top
%tmp47 = fcmp une float 0.000000e+00, undef
%tmp48 = zext i1 %tmp47 to i8
br label %L21
L19: ; preds = %top
br label %L21
L21: ; preds = %L19, %L15
%.sroa.0.0 = phi i8 [ undef, %L19 ], [ %tmp48, %L15 ]
store i8 %.sroa.0.0, i8* undef, align 1
ret void
}
```
Running llc on this input causes a crash in LiveVariables:
```
../llvm-build-debug/bin/llc -mcpu=skylake-avx512 bugpoint-reduced-simplified.ll
Stack dump:
0. Program arguments: ../llvm-build-debug/bin/llc -mcpu=skylake-avx512
bugpoint-reduced-simplified.ll
1. Running pass 'Function Pass Manager' on module
'bugpoint-reduced-simplified.ll'.
2. Running pass 'Live Variable Analysis' on function '@"julia_#3_33548"'
#0 0x000055a23f062d3d llvm::sys::PrintStackTrace(llvm::raw_ostream&)
/home/keno/llvm/lib/Support/Unix/Signals.inc:399:0
#1 0x000055a23f062dd0 PrintStackTraceSignalHandler(void*)
/home/keno/llvm/lib/Support/Unix/Signals.inc:463:0
#2 0x000055a23f060fa5 llvm::sys::RunSignalHandlers()
/home/keno/llvm/lib/Support/Signals.cpp:49:0
#3 0x000055a23f0625a9 SignalHandler(int)
/home/keno/llvm/lib/Support/Unix/Signals.inc:253:0
#4 0x00007f488af32150 __restore_rt
(/lib/x86_64-linux-gnu/libpthread.so.0+0x13150)
#5 0x000055a23cc1e43a llvm::MachineInstr::getParent()
/home/keno/llvm/include/llvm/CodeGen/MachineInstr.h:157:0
#6 0x000055a23e31b126 llvm::LiveVariables::runOnBlock(llvm::MachineBasicBlock*,
unsigned int) /home/keno/llvm/lib/CodeGen/LiveVariables.cpp:596:0
#7 0x000055a23e31b6c4
llvm::LiveVariables::runOnMachineFunction(llvm::MachineFunction&)
/home/keno/llvm/lib/CodeGen/LiveVariables.cpp:651:0
#8 0x000055a23e3a9b7f llvm::MachineFunctionPass::runOnFunction(llvm::Function&)
/home/keno/llvm/lib/CodeGen/MachineFunctionPass.cpp:62:0
#9 0x000055a23e8601f2 llvm::FPPassManager::runOnFunction(llvm::Function&)
/home/keno/llvm/lib/IR/LegacyPassManager.cpp:1520:0
#10 0x000055a23e860397 llvm::FPPassManager::runOnModule(llvm::Module&)
/home/keno/llvm/lib/IR/LegacyPassManager.cpp:1541:0
#11 0x000055a23e86071f (anonymous
namespace)::MPPassManager::runOnModule(llvm::Module&)
/home/keno/llvm/lib/IR/LegacyPassManager.cpp:1597:0
#12 0x000055a23e860e49 llvm::legacy::PassManagerImpl::run(llvm::Module&)
/home/keno/llvm/lib/IR/LegacyPassManager.cpp:1700:0
#13 0x000055a23e861041 llvm::legacy::PassManager::run(llvm::Module&)
/home/keno/llvm/lib/IR/LegacyPassManager.cpp:1732:0
#14 0x000055a23cbe3a76 compileModule(char**, llvm::LLVMContext&)
/home/keno/llvm/tools/llc/llc.cpp:575:0
#15 0x000055a23cbe21b3 main /home/keno/llvm/tools/llc/llc.cpp:345:0
#16 0x00007f4889e4c1c1 __libc_start_main
/build/glibc-itYbWN/glibc-2.26/csu/../csu/libc-start.c:342:0
#17 0x000055a23cbdff1a _start (../llvm-build-debug/bin/llc+0x1187f1a)
```
Cursory debugging suggests an IMPLICIT_DEF node is getting removed by the X86
Domain Reassignment pass when it shouldn't be.
Reduced from Julia bug <a href="https://github.com/JuliaLang/julia/issues/27080">https://github.com/JuliaLang/julia/issues/27080</a>.</pre>
</div>
</p>
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