; bin/opt -passes=loop-vectorize test.ll -S
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

define i16 @main() {
entry:
  br label %safe_lshift_func_uint16_t_u_s.exit.i.i

safe_lshift_func_uint16_t_u_s.exit.i.i:           ; preds = %safe_lshift_func_uint16_t_u_s.exit.i.i, %entry
  %l_1488.0377.i.i = phi i16 [ 0, %entry ], [ %l_1488.2.lcssa.2.i.i, %safe_lshift_func_uint16_t_u_s.exit.i.i ]
  %storemerge376.i.i = phi i16 [ 1, %entry ], [ %inc275.i.i, %safe_lshift_func_uint16_t_u_s.exit.i.i ]
  %0 = load i32, ptr null, align 4
  %tobool254.not.2.i.i = icmp eq i32 %0, 0
  %l_1488.2.lcssa.2.i.i = select i1 %tobool254.not.2.i.i, i16 1, i16 0
  %inc275.i.i = add i16 %storemerge376.i.i, 1
  %exitcond.not.i.i = icmp eq i16 %inc275.i.i, 0
  br i1 %exitcond.not.i.i, label %func_210.exit, label %safe_lshift_func_uint16_t_u_s.exit.i.i

func_210.exit:                                    ; preds = %safe_lshift_func_uint16_t_u_s.exit.i.i
  ret i16 %l_1488.0377.i.i
}

Instruction does not dominate all uses!
  %4 = extractelement <4 x i16> %2, i32 0
  %scalar.recur.init = phi i16 [ %4, %middle.block ], [ 0, %entry ]
Instruction does not dominate all uses!
  %2 = select <4 x i1> %1, <4 x i16> splat (i16 1), <4 x i16> zeroinitializer
  %4 = extractelement <4 x i16> %2, i32 0
PHI nodes not grouped at top of basic block!
  %bc.resume.val = phi i16 [ -7, %middle.block ], [ 1, %entry ]
label %scalar.ph
opt: /root/llvm-project/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp:10182: bool llvm::LoopVectorizePass::processLoop(llvm::Loop*): Assertion `!verifyFunction(*F, &dbgs())' failed.
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace and instructions to reproduce the bug.
Stack dump:
0.	Program arguments: /opt/compiler-explorer/clang-assertions-trunk/bin/opt -o /app/output.s -S -passes=loop-vectorize <source>
1.	Running pass "function(loop-vectorize<no-interleave-forced-only;no-vectorize-forced-only;>)" on module "<source>"
2.	Running pass "loop-vectorize<no-interleave-forced-only;no-vectorize-forced-only;>" on function "main"
 #0 0x000000000589ea68 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x589ea68)
 #1 0x000000000589b914 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
 #2 0x00007e16e6e42520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #3 0x00007e16e6e969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
 #4 0x00007e16e6e42476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
 #5 0x00007e16e6e287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
 #6 0x00007e16e6e2871b (/lib/x86_64-linux-gnu/libc.so.6+0x2871b)
 #7 0x00007e16e6e39e96 (/lib/x86_64-linux-gnu/libc.so.6+0x39e96)
 #8 0x00000000036379e9 llvm::LoopVectorizePass::processLoop(llvm::Loop*) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x36379e9)
 #9 0x0000000003639970 llvm::LoopVectorizePass::runImpl(llvm::Function&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x3639970)
#10 0x000000000363a055 llvm::LoopVectorizePass::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x363a055)
#11 0x0000000002f3481e llvm::detail::PassModel<llvm::Function, llvm::LoopVectorizePass, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x2f3481e)
#12 0x0000000005687c01 llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x5687c01)
#13 0x0000000000eeb6ee llvm::detail::PassModel<llvm::Function, llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0xeeb6ee)
#14 0x000000000568616a llvm::ModuleToFunctionPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x568616a)
#15 0x000000000096f08e llvm::detail::PassModel<llvm::Module, llvm::ModuleToFunctionPassAdaptor, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x96f08e)
#16 0x0000000005685b21 llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x5685b21)
#17 0x0000000000979388 llvm::runPassPipeline(llvm::StringRef, llvm::Module&, llvm::TargetMachine*, llvm::TargetLibraryInfoImpl*, llvm::ToolOutputFile*, llvm::ToolOutputFile*, llvm::ToolOutputFile*, llvm::StringRef, llvm::ArrayRef<llvm::PassPlugin>, llvm::ArrayRef<std::function<void (llvm::PassBuilder&)>>, llvm::opt_tool::OutputKind, llvm::opt_tool::VerifierKind, bool, bool, bool, bool, bool, bool, bool, bool) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x979388)
#18 0x000000000096d409 optMain (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x96d409)
#19 0x00007e16e6e29d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#20 0x00007e16e6e29e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#21 0x0000000000964555 _start (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x964555)
Program terminated with signal: SIGSEGV
Compiler returned: 139