[PATCH] D137140: [SDAG] Allow scalable vectors in ComputeKnownBits

Fri Dec 2 20:36:02 PST 2022

rupprecht added a comment.

  ; ModuleID = 'repro.ll'
  source_filename = "repro.ll"
  target datalayout = "e-m:e-p:32:32:32-a:0-n16:32-i64:64:64-i32:32:32-i16:16:16-i1:8:8-f32:32:32-f64:64:64-v32:32:32-v64:64:64-v512:512:512-v1024:1024:1024-v2048:2048:2048"
  target triple = "hexagon-unknown--elf"

  ; Function Attrs: nocallback nofree nosync nounwind willreturn memory(none)
  declare <32 x i32> @llvm.hexagon.V6.lo.128B(<64 x i32>) #0

  define i32 @widget(<128 x i16> %arg, ptr %arg1) #1 {
  bb:
    br label %bb2

  bb2:                                              ; preds = %bb2, %bb
    %tmp = add <128 x i16> %arg, <i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1, i16 1>
    %tmp3 = bitcast <128 x i16> %tmp to <64 x i32>
    %tmp4 = tail call <32 x i32> @llvm.hexagon.V6.lo.128B(<64 x i32> %tmp3)
    store <32 x i32> %tmp4, ptr %arg1, align 1024
    br label %bb2
  }

  attributes #0 = { nocallback nofree nosync nounwind willreturn memory(none) }
  attributes #1 = { "target-features"="+hvx-length128b,+long-calls,+hvxv62" }

Repro steps: `llc repro.ll -o /dev/null`. That command is ~instant near trunk (122.6 ms ±   5.9 ms). It seems to be going forever with this patch.

Here's a couple stack traces where it's stuck:

  (lldb) bt
  * thread #1, name = 'llc', stop reason = signal SIGSTOP
    * frame #0: 0x00005555590bd7b4 llc`AddNodeIDNode(llvm::FoldingSetNodeID&, unsigned int, llvm::SDVTList, llvm::ArrayRef<llvm::SDValue>) [inlined] llvm::SmallVectorTemplateBase<unsigned int, true>::push_back(this=0x00007fffffff8970, Elt=1679) at SmallVector.h:568:33
      frame #1: 0x00005555590bd7a7 llc`AddNodeIDNode(llvm::FoldingSetNodeID&, unsigned int, llvm::SDVTList, llvm::ArrayRef<llvm::SDValue>) [inlined] llvm::FoldingSetNodeID::AddInteger(this=0x00007fffffff8970, I=1679) at FoldingSet.h:340:38
      frame #2: 0x00005555590bd7a7 llc`AddNodeIDNode(llvm::FoldingSetNodeID&, unsigned int, llvm::SDVTList, llvm::ArrayRef<llvm::SDValue>) [inlined] llvm::FoldingSetNodeID::AddInteger(this=0x00007fffffff8970, I=<unavailable>) at FoldingSet.h:354:5
      frame #3: 0x00005555590bd77c llc`AddNodeIDNode(llvm::FoldingSetNodeID&, unsigned int, llvm::SDVTList, llvm::ArrayRef<llvm::SDValue>) [inlined] llvm::FoldingSetNodeID::AddInteger(this=0x00007fffffff8970, I=<unavailable>) at FoldingSet.h:346:7
      frame #4: 0x00005555590bd77c llc`AddNodeIDNode(llvm::FoldingSetNodeID&, unsigned int, llvm::SDVTList, llvm::ArrayRef<llvm::SDValue>) [inlined] llvm::FoldingSetNodeID::AddPointer(this=0x00007fffffff8970, Ptr=<unavailable>) at FoldingSet.h:337:5
      frame #5: 0x00005555590bd77c llc`AddNodeIDNode(llvm::FoldingSetNodeID&, unsigned int, llvm::SDVTList, llvm::ArrayRef<llvm::SDValue>) [inlined] AddNodeIDValueTypes(ID=0x00007fffffff8970, VTList=<unavailable>) at SelectionDAG.cpp:643:6
      frame #6: 0x00005555590bd77c llc`AddNodeIDNode(ID=0x00007fffffff8970, OpC=11, VTList=<unavailable>, OpList=ArrayRef<llvm::SDValue> @ 0x0000246d579f2b40) at SelectionDAG.cpp:667:3
      frame #7: 0x00005555590c140e llc`llvm::SelectionDAG::getConstant(this=0x0000068f3fc1ae00, Val=<unavailable>, DL=0x00007fffffffa5e0, VT=EVT @ 0x00007fffffff8a90, isT=<unavailable>, isO=<unavailable>) at SelectionDAG.cpp:1612:3
      frame #8: 0x00005555590c0716 llc`llvm::SelectionDAG::getConstant(unsigned long, llvm::SDLoc const&, llvm::EVT, bool, bool) [inlined] llvm::SelectionDAG::getConstant(this=0x0000068f3fc1ae00, Val=0x00007fffffff8b18, DL=0x00007fffffffa5e0, VT=EVT @ 0x0000246d4b6ffc50, isT=false, isO=false) at SelectionDAG.cpp:1525:10
      frame #9: 0x00005555590c06e5 llc`llvm::SelectionDAG::getConstant(this=0x0000068f3fc1ae00, Val=<unavailable>, DL=0x00007fffffffa5e0, VT=EVT @ 0x00007fffffff8b28, isT=false, isO=false) at SelectionDAG.cpp:1520:10
      frame #10: 0x00005555584d1172 llc`llvm::HexagonTargetLowering::buildVector32(this=0x0000068f3fd442e0, Elem=ArrayRef<llvm::SDValue> @ 0x0000246d579f2b40, dl=<unavailable>, VecTy=(SimpleTy = v2i16), DAG=0x0000068f3fc1ae00) const at HexagonISelLowering.cpp:2513:40
      frame #11: 0x00005555584dac39 llc`llvm::HexagonTargetLowering::buildHvxVectorReg(this=0x0000068f3fd442e0, Values=ArrayRef<llvm::SDValue> @ 0x0000246d4b6ffc50, dl=0x00007fffffffa5e0, VecTy=(SimpleTy = v64i16), DAG=0x0000068f3fc1ae00) const at HexagonISelLoweringHVX.cpp:799:19
      frame #12: 0x00005555584dfff2 llc`llvm::HexagonTargetLowering::LowerHvxBuildVector(this=0x0000068f3fd442e0, Op=<unavailable>, DAG=0x0000068f3fc1ae00) const at HexagonISelLoweringHVX.cpp:1621:18
      frame #13: 0x00005555584e8dc5 llc`llvm::HexagonTargetLowering::LowerHvxOperation(this=0x0000068f3fd442e0, Op=SDValue @ 0x0000246d55f19080, DAG=0x0000068f3fc1ae00) const at HexagonISelLoweringHVX.cpp:3202:47
      frame #14: 0x00005555584d5be0 llc`llvm::HexagonTargetLowering::LowerOperation(this=0x0000068f3fd442e0, Op=SDValue @ 0x0000246d5d77ac20, DAG=0x0000068f3fc1ae00) const at HexagonISelLowering.cpp:3316:21
      frame #15: 0x0000555559085280 llc`(anonymous namespace)::SelectionDAGLegalize::LegalizeOp(this=0x00007fffffffaa98, Node=0x0000068f3fd9f690) at LegalizeDAG.cpp:1294:29
      frame #16: 0x000055555908869a llc`llvm::SelectionDAG::LegalizeOp(this=<unavailable>, N=<unavailable>, UpdatedNodes=<unavailable>) at LegalizeDAG.cpp:5125:13
      frame #17: 0x0000555558feeeeb llc`llvm::SelectionDAG::Combine(llvm::CombineLevel, llvm::AAResults*, llvm::CodeGenOpt::Level) at DAGCombiner.cpp:1608:27
      frame #18: 0x0000555558feeac6 llc`llvm::SelectionDAG::Combine(this=<unavailable>, Level=<unavailable>, AA=<unavailable>, OptLevel=<unavailable>) at DAGCombiner.cpp:25513:36
      frame #19: 0x000055555914cb17 llc`llvm::SelectionDAGISel::CodeGenAndEmitDAG(this=0x0000068f3fc4e600) at SelectionDAGISel.cpp:913:13
      frame #20: 0x000055555914c67f llc`llvm::SelectionDAGISel::SelectBasicBlock(this=<unavailable>, Begin=<unavailable>, End=<unavailable>, HadTailCall=<unavailable>) at SelectionDAGISel.cpp:689:3 [artificial]
      frame #21: 0x000055555914bfd9 llc`llvm::SelectionDAGISel::SelectAllBasicBlocks(this=0x0000068f3fc4e600, Fn=0x0000068f3fc92088) at SelectionDAGISel.cpp:1637:7
      frame #22: 0x0000555559149941 llc`llvm::SelectionDAGISel::runOnMachineFunction(this=0x0000068f3fc4e600, mf=0x0000068f3fc7bb00) at SelectionDAGISel.cpp:469:3
      frame #23: 0x00005555585a1b67 llc`llvm::HexagonDAGToDAGISel::runOnMachineFunction(this=0x0000068f3fc4e600, MF=0x0000068f3fc7bb00) at HexagonISelDAGToDAG.h:44:23
      frame #24: 0x0000555558e57ec9 llc`llvm::MachineFunctionPass::runOnFunction(this=0x0000068f3fc4e600, F=0x0000068f3fc92088) at MachineFunctionPass.cpp:91:13
      frame #25: 0x0000555559b656b5 llc`llvm::FPPassManager::runOnFunction(this=0x0000068f3fc90000, F=0x0000068f3fc92088) at LegacyPassManager.cpp:1430:27
      frame #26: 0x0000555559b6c4a4 llc`llvm::FPPassManager::runOnModule(this=0x0000068f3fc90000, M=<unavailable>) at LegacyPassManager.cpp:1476:16
      frame #27: 0x0000555559b65d75 llc`llvm::legacy::PassManagerImpl::run(llvm::Module&) at LegacyPassManager.cpp:1545:27
      frame #28: 0x0000555559b65a31 llc`llvm::legacy::PassManagerImpl::run(this=0x0000068f3fc7a900, M=0x0000068f3fc4e300) at LegacyPassManager.cpp:535:44
      frame #29: 0x0000555557cc937c llc`main at llc.cpp:733:8
      frame #30: 0x0000555557cc887c llc`main(argc=<unavailable>, argv=<unavailable>) at llc.cpp:417:22
      frame #31: 0x00007ffff7d0d633 libc.so.6`__libc_start_main + 243
      frame #32: 0x0000555557cc442a llc`_start at start.S:120
  (lldb) c
  Process 2800685 resuming
  Process 2800685 stopped
  * thread #1, name = 'llc', stop reason = signal SIGSTOP
      frame #0: 0x00005555590cbf6f llc`llvm::SelectionDAG::computeKnownBits(this=0x0000068f3fc1ae00, Op=SDValue @ 0x00007fffffff8a90, DemandedElts=0x00007fffffff9300, Depth=2) const at SelectionDAG.cpp:3154:37
  (lldb) bt
  * thread #1, name = 'llc', stop reason = signal SIGSTOP
    * frame #0: 0x00005555590cbf6f llc`llvm::SelectionDAG::computeKnownBits(this=0x0000068f3fc1ae00, Op=SDValue @ 0x00007fffffff8a90, DemandedElts=0x00007fffffff9300, Depth=2) const at SelectionDAG.cpp:3154:37
      frame #1: 0x00005555591e2ebd llc`llvm::TargetLowering::SimplifyDemandedBits(this=0x0000068f3fd442e0, Op=SDValue @ 0x00007fffffff9388, OriginalDemandedBits=0x00007fffffff9b38, OriginalDemandedElts=0x00007fffffff9a60, Known=0x00007fffffff99d0, TLO=0x00007fffffffa3f0, Depth=2, AssumeSingleUse=<unavailable>) const at TargetLowering.cpp:0
      frame #2: 0x00005555591dc4c1 llc`llvm::TargetLowering::SimplifyDemandedBits(this=0x0000068f3fd442e0, Op=SDValue @ 0x00007fffffff9b48, OriginalDemandedBits=0x00007fffffffa2a0, OriginalDemandedElts=0x00007fffffffa280, Known=0x00007fffffffa190, TLO=0x00007fffffffa3f0, Depth=1, AssumeSingleUse=<unavailable>) const at TargetLowering.cpp:1282:11
      frame #3: 0x00005555591de0ad llc`llvm::TargetLowering::SimplifyDemandedBits(this=0x0000068f3fd442e0, Op=SDValue @ 0x00007fffffffa308, OriginalDemandedBits=0x00007fffffffa480, OriginalDemandedElts=0x00007fffffffa388, Known=0x00007fffffffa420, TLO=0x00007fffffffa3f0, Depth=0, AssumeSingleUse=<unavailable>) const at TargetLowering.cpp:2585:9
      frame #4: 0x00005555591db272 llc`llvm::TargetLowering::SimplifyDemandedBits(this=0x0000068f3fd442e0, Op=SDValue @ 0x0000246d57d150e0, DemandedBits=0x00007fffffffa480, Known=0x00007fffffffa420, TLO=0x00007fffffffa3f0, Depth=0, AssumeSingleUse=<unavailable>) const at TargetLowering.cpp:649:10
      frame #5: 0x000055555903ce7c llc`(anonymous namespace)::DAGCombiner::SimplifyDemandedBits(this=0x00007fffffffaaf8, Op=<unavailable>, DemandedBits=<unavailable>) at DAGCombiner.cpp:333:16
      frame #6: 0x000055555903b866 llc`(anonymous namespace)::DAGCombiner::SimplifyDemandedBits(this=0x00007fffffffaaf8, Op=SDValue @ 0x0000246d71aca5c0) at DAGCombiner.cpp:327:14
      frame #7: 0x0000555559038bb4 llc`(anonymous namespace)::DAGCombiner::visitADDLike(this=0x00007fffffffaaf8, N=0x0000068f3fd9f1c0) at DAGCombiner.cpp:2590:7
      frame #8: 0x0000555558ff37eb llc`(anonymous namespace)::DAGCombiner::visitADD(this=0x00007fffffffaaf8, N=0x0000068f3fd9f1c0) at DAGCombiner.cpp:2649:26
      frame #9: 0x0000555558ff1f40 llc`(anonymous namespace)::DAGCombiner::combine(llvm::SDNode*) [inlined] (anonymous namespace)::DAGCombiner::visit(this=0x00007fffffffaaf8, N=0x0000068f3fd9f1c0) at DAGCombiner.cpp:1682:40
      frame #10: 0x0000555558ff1eda llc`(anonymous namespace)::DAGCombiner::combine(this=0x00007fffffffaaf8, N=0x0000068f3fd9f1c0) at DAGCombiner.cpp:1829:10
      frame #11: 0x0000555558fef0f2 llc`llvm::SelectionDAG::Combine(llvm::CombineLevel, llvm::AAResults*, llvm::CodeGenOpt::Level) at DAGCombiner.cpp:1627:18
      frame #12: 0x0000555558feeac6 llc`llvm::SelectionDAG::Combine(this=<unavailable>, Level=<unavailable>, AA=<unavailable>, OptLevel=<unavailable>) at DAGCombiner.cpp:25513:36
      frame #13: 0x000055555914cb17 llc`llvm::SelectionDAGISel::CodeGenAndEmitDAG(this=0x0000068f3fc4e600) at SelectionDAGISel.cpp:913:13
      frame #14: 0x000055555914c67f llc`llvm::SelectionDAGISel::SelectBasicBlock(this=<unavailable>, Begin=<unavailable>, End=<unavailable>, HadTailCall=<unavailable>) at SelectionDAGISel.cpp:689:3 [artificial]
      frame #15: 0x000055555914bfd9 llc`llvm::SelectionDAGISel::SelectAllBasicBlocks(this=0x0000068f3fc4e600, Fn=0x0000068f3fc92088) at SelectionDAGISel.cpp:1637:7
      frame #16: 0x0000555559149941 llc`llvm::SelectionDAGISel::runOnMachineFunction(this=0x0000068f3fc4e600, mf=0x0000068f3fc7bb00) at SelectionDAGISel.cpp:469:3
      frame #17: 0x00005555585a1b67 llc`llvm::HexagonDAGToDAGISel::runOnMachineFunction(this=0x0000068f3fc4e600, MF=0x0000068f3fc7bb00) at HexagonISelDAGToDAG.h:44:23
      frame #18: 0x0000555558e57ec9 llc`llvm::MachineFunctionPass::runOnFunction(this=0x0000068f3fc4e600, F=0x0000068f3fc92088) at MachineFunctionPass.cpp:91:13
      frame #19: 0x0000555559b656b5 llc`llvm::FPPassManager::runOnFunction(this=0x0000068f3fc90000, F=0x0000068f3fc92088) at LegacyPassManager.cpp:1430:27
      frame #20: 0x0000555559b6c4a4 llc`llvm::FPPassManager::runOnModule(this=0x0000068f3fc90000, M=<unavailable>) at LegacyPassManager.cpp:1476:16
      frame #21: 0x0000555559b65d75 llc`llvm::legacy::PassManagerImpl::run(llvm::Module&) at LegacyPassManager.cpp:1545:27
      frame #22: 0x0000555559b65a31 llc`llvm::legacy::PassManagerImpl::run(this=0x0000068f3fc7a900, M=0x0000068f3fc4e300) at LegacyPassManager.cpp:535:44
      frame #23: 0x0000555557cc937c llc`main at llc.cpp:733:8
      frame #24: 0x0000555557cc887c llc`main(argc=<unavailable>, argv=<unavailable>) at llc.cpp:417:22
      frame #25: 0x00007ffff7d0d633 libc.so.6`__libc_start_main + 243
      frame #26: 0x0000555557cc442a llc`_start at start.S:120

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D137140/new/

https://reviews.llvm.org/D137140