Assertion `(BestFactor.Width == LegacyVF.Width || BestPlan.hasEarlyExit() || ... || planContainsAdditionalSimplifications(getPlanFor(LegacyVF.Width), CostCtx, OrigLoop)) && " VPlan cost model and legacy cost model disagreed"' failed.

[TatyanaDoubts]

Full Assertion message:

Assertion `(BestFactor.Width == LegacyVF.Width || BestPlan.hasEarlyExit() || planContainsAdditionalSimplifications(getPlanFor(BestFactor.Width), CostCtx, OrigLoop) || planContainsAdditionalSimplifications(getPlanFor(LegacyVF.Width), CostCtx, OrigLoop)) && " VPlan cost model and legacy cost model disagreed"' failed.

To reproduce run opt -passes=loop-vectorize with the test below:

; ModuleID = './reduced.ll'
source_filename = "./reduced.ll"
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128-Fn32-ni:1-p2:32:8:8:32-ni:2"
target triple = "aarch64-none-linux-gnu"

define i32 @wombat() gc "statepoint-example" {
bb:
  br label %bb2

bb1:                                              ; preds = %bb2
  %phi = phi i8 [ %or, %bb2 ]
  ret i32 0

bb2:                                              ; preds = %bb2, %bb
  %phi3 = phi i8 [ 0, %bb ], [ %or, %bb2 ]
  %phi4 = phi i32 [ 2, %bb ], [ %add, %bb2 ]
  %phi5 = phi i32 [ 0, %bb ], [ %srem, %bb2 ]
  %phi6 = phi i32 [ 0, %bb ], [ %phi4, %bb2 ]
  %mul = mul i32 %phi5, 0
  %trunc = trunc i32 %mul to i8
  %or = or i8 %trunc, %phi3
  %srem = srem i32 0, %phi6
  %add = add i32 %phi4, 1
  %icmp = icmp ugt i32 %phi4, 3
  br i1 %icmp, label %bb1, label %bb2
}

Reproducer: https://godbolt.org/z/7qEMh5Mq9

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 "wombat"
 #0 0x0000000005589f78 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x5589f78)
 #1 0x0000000005587904 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
 #2 0x00007198a6842520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #3 0x00007198a68969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
 #4 0x00007198a6842476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
 #5 0x00007198a68287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
 #6 0x00007198a682871b (/lib/x86_64-linux-gnu/libc.so.6+0x2871b)
 #7 0x00007198a6839e96 (/lib/x86_64-linux-gnu/libc.so.6+0x39e96)
 #8 0x00000000044b82a6 llvm::LoopVectorizationPlanner::computeBestVF() (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x44b82a6)
 #9 0x00000000044ce21a llvm::LoopVectorizePass::processLoop(llvm::Loop*) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x44ce21a)
#10 0x00000000044d0df0 llvm::LoopVectorizePass::runImpl(llvm::Function&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x44d0df0)
#11 0x00000000044d1443 llvm::LoopVectorizePass::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x44d1443)
#12 0x000000000324211e 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+0x324211e)
#13 0x0000000005383340 llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x5383340)
#14 0x0000000000e8682e 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+0xe8682e)
#15 0x0000000005381c13 llvm::ModuleToFunctionPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x5381c13)
#16 0x0000000000e8567e 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+0xe8567e)
#17 0x0000000005381620 llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x5381620)
#18 0x0000000000949a9a 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+0x949a9a)
#19 0x000000000093d26c optMain (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x93d26c)
#20 0x00007198a6829d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#21 0x00007198a6829e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#22 0x0000000000934ea5 _start (/opt/compiler-explorer/clang-assertions-trunk/bin/opt+0x934ea5)
Program terminated with signal: SIGSEGV
Compiler returned: 139

[frederick-vs-ja]

This looks very like a duplicate of #139060.