[AMDGPU][UnifyLoopExits] Assertion `!IsSuccessor(To, From) && "Deleted edge still exists in the CFG!"' failed.

[XChy]

Reproducer: https://godbolt.org/z/PaGjcrMTa
Testcase:

target datalayout = "e-m:e-p:64:64-p1:64:64-p2:32:32-p3:32:32-p4:64:64-p5:32:32-p6:32:32-p7:160:256:256:32-p8:128:128:128:48-p9:192:256:256:32-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128-v192:256-v256:256-v512:512-v1024:1024-v2048:2048-n32:64-S32-A5-G1-ni:7:8:9"
target triple = "amdgcn-amd-amdhsa"

define void @func_33() {
entry:
  br label %BS_LABEL_0

BS_LABEL_0:                                       ; preds = %BS_LABEL_0, %entry
  callbr void asm sideeffect "", "!i,!i"()
          to label %BS_LABEL_4 [label %BS_LABEL_0, label %BS_LABEL_4]

BS_LABEL_4:                                       ; preds = %BS_LABEL_0, %BS_LABEL_0
  ret void
}

Dumps:

llc: /root/llvm-project/llvm/include/llvm/Support/GenericDomTreeConstruction.h:927: static void llvm::DomTreeBuilder::SemiNCAInfo<DomTreeT>::DeleteEdge(DomTreeT&, llvm::DomTreeBuilder::SemiNCAInfo<DomTreeT>::BatchUpdatePtr, llvm::DomTreeBuilder::SemiNCAInfo<DomTreeT>::NodePtr, llvm::DomTreeBuilder::SemiNCAInfo<DomTreeT>::NodePtr) [with DomTreeT = llvm::DominatorTreeBase<llvm::BasicBlock, false>; llvm::DomTreeBuilder::SemiNCAInfo<DomTreeT>::BatchUpdatePtr = llvm::DomTreeBuilder::SemiNCAInfo<llvm::DominatorTreeBase<llvm::BasicBlock, false> >::BatchUpdateInfo*; llvm::DomTreeBuilder::SemiNCAInfo<DomTreeT>::NodePtr = llvm::BasicBlock*]: Assertion `!IsSuccessor(To, From) && "Deleted edge still exists in the CFG!"' 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/llc -o /app/output.s -x86-asm-syntax=intel -O1 <source>
1.	Running pass 'Function Pass Manager' on module '<source>'.
2.	Running pass 'Fixup each natural loop to have a single exit block' on function '@func_33'
 #0 0x0000000004205548 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x4205548)
 #1 0x00000000042023f4 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
 #2 0x000072b21aa42520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
 #3 0x000072b21aa969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
 #4 0x000072b21aa42476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
 #5 0x000072b21aa287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
 #6 0x000072b21aa2871b (/lib/x86_64-linux-gnu/libc.so.6+0x2871b)
 #7 0x000072b21aa39e96 (/lib/x86_64-linux-gnu/libc.so.6+0x39e96)
 #8 0x00000000036ac527 (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x36ac527)
 #9 0x00000000036b29ba void llvm::DomTreeBuilder::ApplyUpdates<llvm::DominatorTreeBase<llvm::BasicBlock, false>>(llvm::DominatorTreeBase<llvm::BasicBlock, false>&, llvm::GraphDiff<llvm::DominatorTreeBase<llvm::BasicBlock, false>::NodePtr, llvm::DominatorTreeBase<llvm::BasicBlock, false>::IsPostDominator>&, llvm::GraphDiff<llvm::DominatorTreeBase<llvm::BasicBlock, false>::NodePtr, llvm::DominatorTreeBase<llvm::BasicBlock, false>::IsPostDominator>*) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x36b29ba)
#10 0x00000000036b39fb llvm::DominatorTreeBase<llvm::BasicBlock, false>::applyUpdates(llvm::ArrayRef<llvm::cfg::Update<llvm::BasicBlock*>>) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x36b39fb)
#11 0x0000000002b61c35 llvm::GenericDomTreeUpdater<llvm::DomTreeUpdater, llvm::DominatorTree, llvm::PostDominatorTree>::applyUpdates(llvm::ArrayRef<llvm::cfg::Update<llvm::BasicBlock*>>) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x2b61c35)
#12 0x000000000425da75 llvm::SplitCallBrEdge(llvm::BasicBlock*, llvm::BasicBlock*, unsigned int, llvm::DomTreeUpdater*, llvm::GenericCycleInfo<llvm::GenericSSAContext<llvm::Function>>*, llvm::LoopInfo*, bool*) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x425da75)
#13 0x00000000044639ba unifyLoopExits(llvm::DominatorTree&, llvm::LoopInfo&, llvm::Loop*) UnifyLoopExits.cpp:0:0
#14 0x0000000004466112 runImpl(llvm::LoopInfo&, llvm::DominatorTree&) UnifyLoopExits.cpp:0:0
#15 0x000000000373f846 llvm::FPPassManager::runOnFunction(llvm::Function&) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x373f846)
#16 0x000000000373fbf1 llvm::FPPassManager::runOnModule(llvm::Module&) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x373fbf1)
#17 0x000000000374045f llvm::legacy::PassManagerImpl::run(llvm::Module&) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x374045f)
#18 0x00000000008fccd4 compileModule(char**, llvm::LLVMContext&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>&) llc.cpp:0:0
#19 0x00000000007c6ef9 main (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x7c6ef9)
#20 0x000072b21aa29d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
#21 0x000072b21aa29e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
#22 0x00000000008f1ed5 _start (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x8f1ed5)
Program terminated with signal: SIGSEGV
Compiler returned: 139

[llvmbot]

@llvm/issue-subscribers-backend-amdgpu

Author: Hongyu Chen (XChy)

Details

Reproducer: https://godbolt.org/z/PaGjcrMTa Testcase: ```llvm target datalayout = "e-m:e-p:64:64-p1:64:64-p2:32:32-p3:32:32-p4:64:64-p5:32:32-p6:32:32-p7:160:256:256:32-p8:128:128:128:48-p9:192:256:256:32-i64:64-v16:16-v24:32-v32:32-v48:64-v96:128-v192:256-v256:256-v512:512-v1024:1024-v2048:2048-n32:64-S32-A5-G1-ni:7:8:9" target triple = "amdgcn-amd-amdhsa"

define void @func_33() {
entry:
br label %BS_LABEL_0

BS_LABEL_0: ; preds = %BS_LABEL_0, %entry
callbr void asm sideeffect "", "!i,!i"()
to label %BS_LABEL_4 [label %BS_LABEL_0, label %BS_LABEL_4]

BS_LABEL_4: ; preds = %BS_LABEL_0, %BS_LABEL_0
ret void
}

Dumps:

llc: /root/llvm-project/llvm/include/llvm/Support/GenericDomTreeConstruction.h:927: static void llvm::DomTreeBuilder::SemiNCAInfo<DomTreeT>::DeleteEdge(DomTreeT&, llvm::DomTreeBuilder::SemiNCAInfo<DomTreeT>::BatchUpdatePtr, llvm::DomTreeBuilder::SemiNCAInfo<DomTreeT>::NodePtr, llvm::DomTreeBuilder::SemiNCAInfo<DomTreeT>::NodePtr) [with DomTreeT = llvm::DominatorTreeBase<llvm::BasicBlock, false>; llvm::DomTreeBuilder::SemiNCAInfo<DomTreeT>::BatchUpdatePtr = llvm::DomTreeBuilder::SemiNCAInfo<llvm::DominatorTreeBase<llvm::BasicBlock, false> >::BatchUpdateInfo*; llvm::DomTreeBuilder::SemiNCAInfo<DomTreeT>::NodePtr = llvm::BasicBlock*]: Assertion `!IsSuccessor(To, From) && "Deleted edge still exists in the CFG!"' 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/llc -o /app/output.s -x86-asm-syntax=intel -O1 <source>

1. Running pass 'Function Pass Manager' on module '<source>'.
2. Running pass 'Fixup each natural loop to have a single exit block' on function '@func_33'
   #0 0x0000000004205548 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x4205548)
   Fixing Rust build #1 0x00000000042023f4 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
   Fix a typo #2 0x000072b21aa42520 (/lib/x86_64-linux-gnu/libc.so.6+0x42520)
   Fix a compilation error on gcc8 #3 0x000072b21aa969fc pthread_kill (/lib/x86_64-linux-gnu/libc.so.6+0x969fc)
   Fix a compilation error on gcc8 #4 0x000072b21aa42476 gsignal (/lib/x86_64-linux-gnu/libc.so.6+0x42476)
   Seedarg/member/wip #5 0x000072b21aa287f3 abort (/lib/x86_64-linux-gnu/libc.so.6+0x287f3)
   Add check for matching HeaderFilter before emitting Diagnostic #6 0x000072b21aa2871b (/lib/x86_64-linux-gnu/libc.so.6+0x2871b)
   Random engine swap #7 0x000072b21aa39e96 (/lib/x86_64-linux-gnu/libc.so.6+0x39e96)
   Update rwlock init #8 0x00000000036ac527 (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x36ac527)
   Next80 merge test #9 0x00000000036b29ba void llvm::DomTreeBuilder::ApplyUpdates<llvm::DominatorTreeBase<llvm::BasicBlock, false>>(llvm::DominatorTreeBase<llvm::BasicBlock, false>&, llvm::GraphDiff<llvm::DominatorTreeBase<llvm::BasicBlock, false>::NodePtr, llvm::DominatorTreeBase<llvm::BasicBlock, false>::IsPostDominator>&, llvm::GraphDiff<llvm::DominatorTreeBase<llvm::BasicBlock, false>::NodePtr, llvm::DominatorTreeBase<llvm::BasicBlock, false>::IsPostDominator>) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x36b29ba)
   Fix typo: 'soruce' -> 'source' #10 0x00000000036b39fb llvm::DominatorTreeBase<llvm::BasicBlock, false>::applyUpdates(llvm::ArrayRef<llvm::cfg::Update<llvm::BasicBlock>>) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x36b39fb)
   fix for gcc 8 #11 0x0000000002b61c35 llvm::GenericDomTreeUpdater<llvm::DomTreeUpdater, llvm::DominatorTree, llvm::PostDominatorTree>::applyUpdates(llvm::ArrayRef<llvm::cfg::Update<llvm::BasicBlock*>>) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x2b61c35)
   Fix "Allman" style example #12 0x000000000425da75 llvm::SplitCallBrEdge(llvm::BasicBlock*, llvm::BasicBlock*, unsigned int, llvm::DomTreeUpdater*, llvm::GenericCycleInfo<llvm::GenericSSAContext<llvm::Function>>, llvm::LoopInfo, bool*) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x425da75)
   Defer diag #13 0x00000000044639ba unifyLoopExits(llvm::DominatorTree&, llvm::LoopInfo&, llvm::Loop*) UnifyLoopExits.cpp:0:0
   WIP lifetime categories #14 0x0000000004466112 runImpl(llvm::LoopInfo&, llvm::DominatorTree&) UnifyLoopExits.cpp:0:0
   Fix ClangOpenCLBuiltinsImpl target not found #15 0x000000000373f846 llvm::FPPassManager::runOnFunction(llvm::Function&) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x373f846)
   __unique_stable_name implementation. #16 0x000000000373fbf1 llvm::FPPassManager::runOnModule(llvm::Module&) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x373fbf1)
   Lockdown test #17 0x000000000374045f llvm::legacy::PassManagerImpl::run(llvm::Module&) (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x374045f)
   Lockdown test #18 0x00000000008fccd4 compileModule(char**, llvm::LLVMContext&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>&) llc.cpp:0:0
   Test commit to check lockdown app #19 0x00000000007c6ef9 main (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x7c6ef9)
   Construct path using a locale #20 0x000072b21aa29d90 (/lib/x86_64-linux-gnu/libc.so.6+0x29d90)
   moved upfront the skip branch insertion code for correctness. #21 0x000072b21aa29e40 __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x29e40)
   Update Applyreplacements.h #22 0x00000000008f1ed5 _start (/opt/compiler-explorer/clang-assertions-trunk/bin/llc+0x8f1ed5)
   Program terminated with signal: SIGSEGV
   Compiler returned: 139

</details>

[ro-i]

Thanks for reporting! Seems like there is an issue with duplicate target blocks, as in your example %BS_LABEL_4 [label %BS_LABEL_0, label %BS_LABEL_4]