Assertion `VF.Width == BestVF && "VPlan cost model and legacy cost model disagreed"' failed.

[TatyanaDoubts]

To reproduce run opt with

-passes=loop-vectorize --mcpu=skylake-avx512 --mattr=+prfchw,-cldemote,+avx,+aes,+sahf,+pclmul,-xop,+crc32,+xsaves,-avx512fp16,-usermsr,-sm4,-egpr,+sse4.1,-avx512ifma,+xsave,+sse4.2,-tsxldtrk,-sm3,-ptwrite,-widekl,+invpcid,+64bit,+xsavec,-avx10.1-512,-avx512vpopcntdq,+cmov,-avx512vp2intersect,+avx512cd,+movbe,-avxvnniint8,-ccmp,-amx-int8,-kl,-avx10.1-256,+evex512,-avxvnni,+rtm,+adx,+avx2,-hreset,-movdiri,-serialize,-sha512,-vpclmulqdq,+avx512vl,-uintr,-cf,+clflushopt,-raoint,-cmpccxadd,+bmi,-amx-tile,+sse,-gfni,-avxvnniint16,-amx-fp16,-zu,-ndd,+xsaveopt,+rdrnd,+avx512f,-amx-bf16,-avx512bf16,-avx512vnni,-push2pop2,+cx8,+avx512bw,+sse3,+pku,-nf,+fsgsbase,-clzero,-mwaitx,-lwp,+lzcnt,-sha,-movdir64b,-ppx,-wbnoinvd,-enqcmd,-avxneconvert,-tbm,-pconfig,-amx-complex,+ssse3,+cx16,+bmi2,+fma,+popcnt,-avxifma,+f16c,-avx512bitalg,-rdpru,+clwb,+mmx,+sse2,+rdseed,-avx512vbmi2,-prefetchi,-rdpid,-fma4,-avx512vbmi,-shstk,-vaes,-waitpkg,-sgx,+fxsr,+avx512dq,-sse4a,-avx512f

with the following test:

; ModuleID = './reduced.ll'
source_filename = "./reduced.ll"
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-ni:1-p2:32:8:8:32-ni:2"
target triple = "x86_64-unknown-linux-gnu"

define void @wombat(i32 %arg) #0 gc "statepoint-example" {
bb:
  %mul = mul i32 %arg, 3
  %zext = zext i32 %arg to i64
  br label %bb1

bb1:                                              ; preds = %bb1, %bb
  %phi = phi i64 [ %add, %bb1 ], [ 4, %bb ]
  %phi2 = phi i32 [ %trunc, %bb1 ], [ %mul, %bb ]
  %getelementptr = getelementptr i32, ptr addrspace(1) null, i64 %phi
  %and = and i32 %phi2, 0
  store i32 0, ptr addrspace(1) %getelementptr, align 4
  %mul3 = mul i64 %phi, %zext
  %add = add i64 %phi, 1
  %icmp = icmp ugt i64 %phi, 65
  %trunc = trunc i64 %mul3 to i32
  br i1 %icmp, label %bb4, label %bb1

bb4:                                              ; preds = %bb1
  ret void
}

Reproducer: https://godbolt.org/z/nPsP7h51n

Stack dump:

0.	Program arguments: /opt/compiler-explorer/clang-assertions-trunk/bin/opt -o /app/output.s -S -passes=loop-vectorize --mcpu=skylake-avx512 --mattr=+prfchw,-cldemote,+avx,+aes,+sahf,+pclmul,-xop,+crc32,+xsaves,-avx512fp16,-usermsr,-sm4,-egpr,+sse4.1,-avx512ifma,+xsave,+sse4.2,-tsxldtrk,-sm3,-ptwrite,-widekl,+invpcid,+64bit,+xsavec,-avx10.1-512,-avx512vpopcntdq,+cmov,-avx512vp2intersect,+avx512cd,+movbe,-avxvnniint8,-ccmp,-amx-int8,-kl,-avx10.1-256,+evex512,-avxvnni,+rtm,+adx,+avx2,-hreset,-movdiri,-serialize,-sha512,-vpclmulqdq,+avx512vl,-uintr,-cf,+clflushopt,-raoint,-cmpccxadd,+bmi,-amx-tile,+sse,-gfni,-avxvnniint16,-amx-fp16,-zu,-ndd,+xsaveopt,+rdrnd,+avx512f,-amx-bf16,-avx512bf16,-avx512vnni,-push2pop2,+cx8,+avx512bw,+sse3,+pku,-nf,+fsgsbase,-clzero,-mwaitx,-lwp,+lzcnt,-sha,-movdir64b,-ppx,-wbnoinvd,-enqcmd,-avxneconvert,-tbm,-pconfig,-amx-complex,+ssse3,+cx16,+bmi2,+fma,+popcnt,-avxifma,+f16c,-avx512bitalg,-rdpru,+clwb,+mmx,+sse2,+rdseed,-avx512vbmi2,-prefetchi,-rdpid,-fma4,-avx512vbmi,-shstk,-vaes,-waitpkg,-sgx,+fxsr,+avx512dq,-sse4a,-avx512f <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 "wombat"
 #0 0x0000000004f053c8 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x4f053c8)
 #1 0x0000000004f02b3c SignalHandler(int) Signals.cpp:0:0
 #2 0x00007458cc042520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #3 0x00007458cc0969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
 #4 0x00007458cc042476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
 #5 0x00007458cc0287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
 #6 0x00007458cc02871b (/lib/x86_64-linux-gnu/libc.so.6+0x2871b)
 #7 0x00007458cc039e96 (/lib/x86_64-linux-gnu/libc.so.6+0x39e96)
 #8 0x0000000003f83f37 llvm::LoopVectorizePass::processLoop(llvm::Loop*) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x3f83f37)
 #9 0x0000000003f86659 llvm::LoopVectorizePass::runImpl(llvm::Function&, llvm::ScalarEvolution&, llvm::LoopInfo&, llvm::TargetTransformInfo&, llvm::DominatorTree&, llvm::BlockFrequencyInfo*, llvm::TargetLibraryInfo*, llvm::DemandedBits&, llvm::AssumptionCache&, llvm::LoopAccessInfoManager&, llvm::OptimizationRemarkEmitter&, llvm::ProfileSummaryInfo*) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x3f86659)
#10 0x0000000003f86cd2 llvm::LoopVectorizePass::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x3f86cd2)
#11 0x0000000002e596ce 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+0x2e596ce)
#12 0x0000000004d02758 llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x4d02758)
#13 0x0000000000de089e 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+0xde089e)
#14 0x0000000004d0114e llvm::ModuleToFunctionPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x4d0114e)
#15 0x0000000000de0eee 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+0xde0eee)
#16 0x0000000004cff2b0 llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x4cff2b0)
#17 0x00000000008e3752 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) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x8e3752)
#18 0x00000000008d667c optMain (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x8d667c)
#19 0x00007458cc029d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#20 0x00007458cc029e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#21 0x00000000008cdade _start (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x8cdade)
Program terminated with signal: SIGSEGV
Compiler returned: 139

[patrick-rivos]

Potentially related: #100591