[MLIR][OpenMP] Updates to initial Taskloop Bounds Implementation by Stylie777 · Pull Request #3 · Stylie777/llvm-project

Stylie777 · 2025-12-19T10:59:17Z

This approach was agreed in the original Taskloop PR here: llvm#166903 (comment). This uses the structArg to transfer the data between outlined functions to better support the bounds in Taskloop.

- Force the first 3 entries to the StructArg to be the bounds info - Ensure it will work when executing the tasks in parallel

tblah

Looks great to me beyond some minor nits. I see O3 can optimize away the extra geps and stores from outlining so I think it is okay to leave them.

tblah · 2025-12-19T11:19:13Z

    PostOutlineCBTy PostOutlineCB;
    BasicBlock *EntryBB, *ExitBB, *OuterAllocaBB;
    SmallVector<Value *, 2> ExcludeArgsFromAggregate;
+    SetVector<Value *> Inputs, Outputs;


I know the other members don't have documentation but I think it would be good to add something because I don't think the use of these is immediately obvious.

I don't think we can use Outputs. IIRC there's an assertion somewhere that there are no live out values. Better to remove it.

Added a comment about the use of Inputs

We still need some definition of Outputs somewhere as the CodeExtractor's extractCodeRegion expects there to be a SetVector for both Inputs and Outputs. The API gives 2 options, one where you just pass the CEAC value, and another that includes the inputs and outputs. I am happy to exclude the Outputs from the OutlineInfo struct, but there will need to be a SetVector made before extracting the code region from OpenMPIRBuilder::finalize.

tblah · 2025-12-19T11:24:29Z

                        llvm::SmallVectorImpl<Instruction *> &ToBeDeleted,
                        OpenMPIRBuilder::InsertPointTy InnerAllocaIP,
-                        const Twine &Name = "", bool AsPtr = true) {
+                        const Twine &Name = "", bool AsPtr = true, bool Is64Bit = false) {


Suggested change

const Twine &Name = "", bool AsPtr = true, bool Is64Bit = false) {

const Twine &Name = "", bool AsPtr = true, IntegerType *IntTy) {

Builder.restoreIP(OuterAllocaIP);

IntTy = IntTy ? IntTy : Builder.getInt32Ty();

More flexible.

tblah · 2025-12-19T11:27:36Z

  } else {
    UseFakeVal =
-        cast<BinaryOperator>(Builder.CreateAdd(FakeVal, Builder.getInt32(10)));
+        cast<BinaryOperator>(Builder.CreateAdd(FakeVal, Is64Bit ? Builder.getInt64(10) : Builder.getInt32(10)));


You could do this from IntTy with llvm::ConstantInt::get or IRBuilderBase::getIntN

Done with ConstantInt::get

tblah · 2025-12-19T11:29:17Z

  OI.ExcludeArgsFromAggregate.push_back(createFakeIntVal(
      Builder, AllocaIP, ToBeDeleted, TaskloopAllocaIP, "global.tid", false));
+  Value *FakeLB = createFakeIntVal(Builder, AllocaIP, ToBeDeleted, TaskloopAllocaIP,
+                   "lb", false, true);


Suggested change

"lb", false, true);

"lb", /*AsPtr=*/false, Builder.getInt64Ty());

It isn't obvious what the bool values mean without some extra help

tblah · 2025-12-19T11:30:34Z

+                   "ub", false, true);
+  Value *FakeStep = createFakeIntVal(Builder, AllocaIP, ToBeDeleted, TaskloopAllocaIP,
+                   "step", false, true);
+  /* For Taskloop, we want to force the bounds being the first 3 inputs in the aggregate struct*/


nit: llvm style is to use C++ style comments

tblah · 2025-12-19T11:30:42Z

-    // HasShareds is true if any variables are captured in the outlined region,
-    // false otherwise.
-    bool HasShareds = StaleCI->arg_size() > 1;
+    /* Create the casting for the Bounds Values that can be used when outlining to replace the uses of the fakes with real values */


nit: comment style

tblah · 2025-12-19T11:34:30Z

                      /*sizeof_task=*/TaskSize, /*sizeof_shared=*/SharedsSize,
                      /*task_func=*/&OutlinedFn});

+    Value *Shareds = StaleCI->getArgOperand(1);


This could be moved above line 2035 to make that section clearer

I've moved this above the declaration for ArgStructAlloca so this can use the Shareds variable rather than calling the getArgOperand function

tblah · 2025-12-19T11:37:53Z

+        if (ConstantInt *CI = dyn_cast<ConstantInt>(Gep.getOperand(2))) {
+          switch (CI->getZExtValue()) {
+          case 0:
+            TaskLB = &I;


It would also be good to check that the value being indexed is the right one, not just the numeric value of the index.

Added a check to make sure the GEP Instruction being checked is using the Shared's as its first operand.

kaviya2510 · 2025-12-22T09:34:44Z

@@ -2015,20 +2033,18 @@ OpenMPIRBuilder::InsertPointOrErrorTy OpenMPIRBuilder::createTaskloop(
    Value *TaskSize = Builder.getInt64(
        divideCeil(M.getDataLayout().getTypeSizeInBits(Taskloop), 8));


Suggested change

divideCeil(M.getDataLayout().getTypeSizeInBits(Taskloop), 8));

divideCeil(M.getDataLayout().getTypeSizeInBits(Task), 8));

kaviya2510

Thank you for the work @Stylie777.

There are some changes that need to be updated for passing the arguments to runtime call __kmpc_taskloop(..). Kindly address those changes.

Rest of the work looks good to me.

kaviya2510 · 2025-12-22T09:35:38Z

@@ -2015,20 +2033,18 @@ OpenMPIRBuilder::InsertPointOrErrorTy OpenMPIRBuilder::createTaskloop(
    Value *TaskSize = Builder.getInt64(
        divideCeil(M.getDataLayout().getTypeSizeInBits(Taskloop), 8));


Suggested change

divideCeil(M.getDataLayout().getTypeSizeInBits(Taskloop), 8));

divideCeil(M.getDataLayout().getTypeSizeInBits(Task), 8));

As we are utilizing structArg to store the the loopbound values, the struct __OMP_STRUCT_TYPE(Taskloop, kmp_task_info, false, VoidPtr, VoidPtr, Int32, VoidPtr, VoidPtr, Int64, Int64, Int64) is no longer needed.

The required size for storing loop bounds can be reserved in kmp_task_t by strutArg itself.

kaviya2510 · 2025-12-22T10:00:10Z

-    Builder.CreateStore(Step_ext, step);
-    llvm::Value *loadstep = Builder.CreateLoad(Builder.getInt64Ty(), step);
+    llvm::Value *Lb = Builder.CreateStructGEP(ArgStructType, TaskShareds, 0);
+    Builder.CreateStore(CastedLBVal, Lb);


Suggested change

Builder.CreateStore(CastedLBVal, Lb);

auto *Idx0 = Builder.getInt32(0);

llvm::Value *Lb = Builder.CreateGEP(ArgStructType, TaskShareds, {Idx0, Builder.getInt32(0)});

The values of lb,ub and step are already populated in StructArg. You can directly access it and pass the pointer to the runtime call __kmpc_taskloop(...)

kaviya2510 · 2025-12-22T10:00:14Z

-                           SharedsSize);
-    }
+    llvm::Value *Ub = Builder.CreateStructGEP(ArgStructType, TaskShareds, 1);
+    Builder.CreateStore(CastedUBVal, Ub);


Same here. Remove the store instruction.

kaviya2510 · 2025-12-22T10:00:35Z

-      Builder.CreateMemCpy(TaskShareds, Alignment, Shareds, Alignment,
-                           SharedsSize);
-    }
+    llvm::Value *Ub = Builder.CreateStructGEP(ArgStructType, TaskShareds, 1);


Suggested change

llvm::Value *Ub = Builder.CreateStructGEP(ArgStructType, TaskShareds, 1);

llvm::Value *Ub =Builder.CreateGEP(ArgStructType, TaskShareds, {Idx0, Builder.getInt32(1)});

GEP to StructArg and get the upper bound value.

kaviya2510 · 2025-12-22T10:01:49Z

+    llvm::Value *Ub = Builder.CreateStructGEP(ArgStructType, TaskShareds, 1);
+    Builder.CreateStore(CastedUBVal, Ub);
+
+    llvm::Value *Step = Builder.CreateStructGEP(ArgStructType, TaskShareds, 2);


Suggested change

llvm::Value *Step = Builder.CreateStructGEP(ArgStructType, TaskShareds, 2);

llvm::Value *Step =Builder.CreateGEP(ArgStructType, TaskShareds, {Idx0, Builder.getInt32(2)});

kaviya2510 · 2025-12-22T10:02:02Z

+    Builder.CreateStore(CastedUBVal, Ub);
+
+    llvm::Value *Step = Builder.CreateStructGEP(ArgStructType, TaskShareds, 2);
+    Builder.CreateStore(CastedStepVal, Step);


Remove the store.

kaviya2510 · 2025-12-22T10:18:33Z

@@ -2127,12 +2161,15 @@ OpenMPIRBuilder::InsertPointOrErrorTy OpenMPIRBuilder::createTaskloop(
        if (Add->getOpcode() == llvm::Instruction::Add) {


Tom raised a concern that this add instruction pattern might also match other unrelated add instructions, and we discussed this in my PR: llvm#166903 (comment)

He suggested looking at the wsloop and distribute implementations for guidance on how this is handled there. I have not had a chance to dig into that yet. Could you please check this once?

Comments at Stylie777#3

Using code/ideas from the x86 backend to optimize a select on a bitcast integer. The previous aarch64 approach was to individually extract the bits from the mask, which is kind of terrible. https://rust.godbolt.org/z/576sndT66 ```llvm define void @if_then_else8(ptr %out, i8 %mask, ptr %if_true, ptr %if_false) { start: %t = load <8 x i32>, ptr %if_true, align 4 %f = load <8 x i32>, ptr %if_false, align 4 %m = bitcast i8 %mask to <8 x i1> %s = select <8 x i1> %m, <8 x i32> %t, <8 x i32> %f store <8 x i32> %s, ptr %out, align 4 ret void } ``` turned into ```asm if_then_else8: // @if_then_else8 sub sp, sp, llvm#16 ubfx w8, w1, llvm#4, #1 and w11, w1, #0x1 ubfx w9, w1, llvm#5, #1 fmov s1, w11 ubfx w10, w1, #1, #1 fmov s0, w8 ubfx w8, w1, llvm#6, #1 ldp q5, q2, [x3] mov v1.h[1], w10 ldp q4, q3, [x2] mov v0.h[1], w9 ubfx w9, w1, #2, #1 mov v1.h[2], w9 ubfx w9, w1, #3, #1 mov v0.h[2], w8 ubfx w8, w1, llvm#7, #1 mov v1.h[3], w9 mov v0.h[3], w8 ushll v1.4s, v1.4h, #0 ushll v0.4s, v0.4h, #0 shl v1.4s, v1.4s, llvm#31 shl v0.4s, v0.4s, llvm#31 cmlt v1.4s, v1.4s, #0 cmlt v0.4s, v0.4s, #0 bsl v1.16b, v4.16b, v5.16b bsl v0.16b, v3.16b, v2.16b stp q1, q0, [x0] add sp, sp, llvm#16 ret ``` With this PR that instead emits ```asm if_then_else8: adrp x8, .LCPI0_1 dup v0.4s, w1 ldr q1, [x8, :lo12:.LCPI0_1] adrp x8, .LCPI0_0 ldr q2, [x8, :lo12:.LCPI0_0] ldp q4, q3, [x2] and v1.16b, v0.16b, v1.16b and v0.16b, v0.16b, v2.16b ldp q5, q2, [x3] cmeq v1.4s, v1.4s, #0 cmeq v0.4s, v0.4s, #0 bsl v1.16b, v2.16b, v3.16b bsl v0.16b, v5.16b, v4.16b stp q0, q1, [x0] ret ``` So substantially shorter. Instead of building the mask element-by-element, this approach (by virtue of not splitting) instead splats the mask value into all vector lanes, performs a bitwise and with powers of 2, and compares with zero to construct the mask vector. cc rust-lang/rust#122376 cc llvm#175769

`SE.getUMaxExpr` causes assertion failure due to type mismatch here: https://github.com/llvm/llvm-project/blob/main/llvm/lib/Analysis/LoopAccessAnalysis.cpp#L253 Running `opt -S -p loop-vectorize -debug-only=loop-vectorize llvm/test/Analysis/LoopAccessAnalysis/type-mismatch-in-scalar-evolution.ll ` without the changes made in LoopAccessAnalysis.cpp causes assertion failure. Attaching the stack dump for reference: ``` LV: Checking a loop in 'loop_contains_store_assumed_bounds' from input.ll LV: Loop hints: force=? width=4 interleave=0 LV: Found a loop: for.body LV: Found an induction variable. opt: /home/kshitij/llvm-project/llvm/lib/Analysis/ScalarEvolution.cpp:3918: const llvm::SCEV* llvm::ScalarEvolution::getMinMaxExpr(llvm::SCEVTypes, llvm::SmallVectorImpl<const llvm::SCEV*>&): Assertion `getEffectiveSCEVType(Ops[i]->getType()) == ETy && "Operand types don't match!"' 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 -S -passes=loop-vectorize -debug-only=loop-vectorize -force-vector-width=4 -disable-output input.ll 1. Running pass "function(loop-vectorize<no-interleave-forced-only;no-vectorize-forced-only;>)" on module "input.ll" 2. Running pass "loop-vectorize<no-interleave-forced-only;no-vectorize-forced-only;>" on function "loop_contains_store_assumed_bounds" #0 0x000058ee97c5e652 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/usr/local/bin/opt+0x4f44652) #1 0x000058ee97c5af0f llvm::sys::RunSignalHandlers() (/usr/local/bin/opt+0x4f40f0f) #2 0x000058ee97c5b05c SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0 #3 0x00007c49d4c45330 (/lib/x86_64-linux-gnu/libc.so.6+0x45330) llvm#4 0x00007c49d4c9eb2c __pthread_kill_implementation ./nptl/pthread_kill.c:44:76 llvm#5 0x00007c49d4c9eb2c __pthread_kill_internal ./nptl/pthread_kill.c:78:10 llvm#6 0x00007c49d4c9eb2c pthread_kill ./nptl/pthread_kill.c:89:10 llvm#7 0x00007c49d4c4527e raise ./signal/../sysdeps/posix/raise.c:27:6 llvm#8 0x00007c49d4c288ff abort ./stdlib/abort.c:81:7 llvm#9 0x00007c49d4c2881b _nl_load_domain ./intl/loadmsgcat.c:1177:9 llvm#10 0x00007c49d4c3b517 (/lib/x86_64-linux-gnu/libc.so.6+0x3b517) llvm#11 0x000058ee98003fdb llvm::ScalarEvolution::getMinMaxExpr(llvm::SCEVTypes, llvm::SmallVectorImpl<llvm::SCEV const*>&) (/usr/local/bin/opt+0x52e9fdb) llvm#12 0x000058ee98004507 llvm::ScalarEvolution::getUMaxExpr(llvm::SCEV const*, llvm::SCEV const*) (/usr/local/bin/opt+0x52ea507) llvm#13 0x000058ee980dc728 llvm::getStartAndEndForAccess(llvm::Loop const*, llvm::SCEV const*, llvm::Type*, llvm::SCEV const*, llvm::SCEV const*, llvm::ScalarEvolution*, llvm::DenseMap<std::pair<llvm::SCEV const*, llvm::Type*>, std::pair<llvm::SCEV const*, llvm::SCEV const*>, llvm::DenseMapInfo<std::pair<llvm::SCEV const*, llvm::Type*>, void>, llvm::detail::DenseMapPair<std::pair<llvm::SCEV const*, llvm::Type*>, std::pair<llvm::SCEV const*, llvm::SCEV const*>>>*, llvm::DominatorTree*, llvm::AssumptionCache*, std::optional<llvm::ScalarEvolution::LoopGuards>&) (/usr/local/bin/opt+0x53c2728) llvm#14 0x000058ee9814008b llvm::isDereferenceableAndAlignedInLoop(llvm::LoadInst*, llvm::Loop*, llvm::ScalarEvolution&, llvm::DominatorTree&, llvm::AssumptionCache*, llvm::SmallVectorImpl<llvm::SCEVPredicate const*>*) (/usr/local/bin/opt+0x542608b) llvm#15 0x000058ee9a0fa1ca llvm::LoopVectorizationLegality::canUncountableExitConditionLoadBeMoved(llvm::BasicBlock*) (/usr/local/bin/opt+0x73e01ca) llvm#16 0x000058ee9a0faee0 llvm::LoopVectorizationLegality::isVectorizableEarlyExitLoop() (/usr/local/bin/opt+0x73e0ee0) llvm#17 0x000058ee9a104678 llvm::LoopVectorizationLegality::canVectorize(bool) (/usr/local/bin/opt+0x73ea678) llvm#18 0x000058ee9a08c953 llvm::LoopVectorizePass::processLoop(llvm::Loop*) (/usr/local/bin/opt+0x7372953) llvm#19 0x000058ee9a090e21 llvm::LoopVectorizePass::runImpl(llvm::Function&) (/usr/local/bin/opt+0x7376e21) llvm#20 0x000058ee9a0914e0 llvm::LoopVectorizePass::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/usr/local/bin/opt+0x73774e0) llvm#21 0x000058ee99e419a5 llvm::detail::PassModel<llvm::Function, llvm::LoopVectorizePass, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) PassBuilderPipelines.cpp:0:0 llvm#22 0x000058ee97f18905 llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/usr/local/bin/opt+0x51fe905) llvm#23 0x000058ee995d70d5 llvm::detail::PassModel<llvm::Function, llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) AMDGPUTargetMachine.cpp:0:0 llvm#24 0x000058ee97f17051 llvm::ModuleToFunctionPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/usr/local/bin/opt+0x51fd051) llvm#25 0x000058ee995d7775 llvm::detail::PassModel<llvm::Module, llvm::ModuleToFunctionPassAdaptor, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) AMDGPUTargetMachine.cpp:0:0 llvm#26 0x000058ee97f1783d llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/usr/local/bin/opt+0x51fd83d) llvm#27 0x000058ee9c153909 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) (/usr/local/bin/opt+0x9439909) llvm#28 0x000058ee97c3f380 optMain (/usr/local/bin/opt+0x4f25380) llvm#29 0x00007c49d4c2a1ca __libc_start_call_main ./csu/../sysdeps/nptl/libc_start_call_main.h:74:3 llvm#30 0x00007c49d4c2a28b call_init ./csu/../csu/libc-start.c:128:20 llvm#31 0x00007c49d4c2a28b __libc_start_main ./csu/../csu/libc-start.c:347:5 llvm#32 0x000058ee97c309a5 _start (/usr/local/bin/opt+0x4f169a5) ``` This is caused by a type mismatch between `SE.getSCEV(DerefRK.IRArgValue)` and `DerefBytesSCEV`. Fixing this by extending them to the wider type.

…bols add' (llvm#188377) Context: lldb might crash when running to a debuggee crashing state and do a target symbols add command. Backtrace: ``` #0 0x000055ca6790dc65 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) /home/hyubo/osmeta/external/llvm-project/llvm/lib/Support/Unix/Signals.inc:848:11 #1 0x000055ca6790e434 PrintStackTraceSignalHandler(void*) /home/hyubo/osmeta/external/llvm-project/llvm/lib/Support/Unix/Signals.inc:931:1 #2 0x000055ca6790b839 llvm::sys::RunSignalHandlers() /home/hyubo/osmeta/external/llvm-project/llvm/lib/Support/Signals.cpp:104:5 #3 0x000055ca6790ff6b SignalHandler(int, siginfo_t*, void*) /home/hyubo/osmeta/external/llvm-project/llvm/lib/Support/Unix/Signals.inc:430:38 llvm#4 0x00007fe9e5e44560 __restore_rt /home/engshare/third-party2/glibc/2.34/src/glibc-2.34/signal/../sysdeps/unix/sysv/linux/libc_sigaction.c:13:0 llvm#5 0x00007fe9e5f25649 syscall /home/engshare/third-party2/glibc/2.34/src/glibc-2.34/misc/../sysdeps/unix/sysv/linux/x86_64/syscall.S:38:0 llvm#6 0x00007fe9ec649170 SignalHandler(int, siginfo_t*, void*) /home/hyubo/osmeta/external/llvm-project/llvm/lib/Support/Unix/Signals.inc:429:7 llvm#7 0x00007fe9e5e44560 __restore_rt /home/engshare/third-party2/glibc/2.34/src/glibc-2.34/signal/../sysdeps/unix/sysv/linux/libc_sigaction.c:13:0 llvm#8 0x00007fe9ebb77bf0 lldb_private::operator<(lldb_private::StackID const&, lldb_private::StackID const&) /home/hyubo/osmeta/external/llvm-project/lldb/source/Target/StackID.cpp:99:16 llvm#9 0x00007fe9ebb6863d CompareStackID(std::shared_ptr<lldb_private::StackFrame> const&, lldb_private::StackID const&) /home/hyubo/osmeta/external/llvm-project/lldb/source/Target/StackFrameList.cpp:683:3 llvm#10 0x00007fe9ebb6d049 bool __gnu_cxx::__ops::_Iter_comp_val<bool (*)(std::shared_ptr<lldb_private::StackFrame> const&, lldb_private::StackID const&)>::operator()<__gnu_cxx::__normal_iterator<std::shared_ptr<lldb_private::StackFrame>*, std::vector<std::shared_ptr<lldb_private::StackFrame>, std::allocator<std::shared_ptr<lldb_private::StackFrame>>>>, lldb_private::StackID const>(__gnu_cxx::__normal_iterator<std::shared_ptr<lldb_private::StackFrame>*, std::vector<std::shared_ptr<lldb_private::StackFrame>, std::allocator<std::shared_ptr<lldb_private::StackFrame>>>>, lldb_private::StackID const&) /mnt/gvfs/third-party2/libgcc/d1129753c8361ac8e9453c0f4291337a4507ebe6/11.x/platform010/5684a5a/include/c++/11.x/bits/predefined_ops.h:196:4 llvm#11 0x00007fe9ebb6cefe __gnu_cxx::__normal_iterator<std::shared_ptr<lldb_private::StackFrame>*, std::vector<std::shared_ptr<lldb_private::StackFrame>, std::allocator<std::shared_ptr<lldb_private::StackFrame>>>> std::__lower_bound<__gnu_cxx::__normal_iterator<std::shared_ptr<lldb_private::StackFrame>*, std::vector<std::shared_ptr<lldb_private::StackFrame>, std::allocator<std::shared_ptr<lldb_private::StackFrame>>>>, lldb_private::StackID, __gnu_cxx::__ops::_Iter_comp_val<bool (*)(std::shared_ptr<lldb_private::StackFrame> const&, lldb_private::StackID const&)>>(__gnu_cxx::__normal_iterator<std::shared_ptr<lldb_private::StackFrame>*, std::vector<std::shared_ptr<lldb_private::StackFrame>, std::allocator<std::shared_ptr<lldb_private::StackFrame>>>>, __gnu_cxx::__normal_iterator<std::shared_ptr<lldb_private::StackFrame>*, std::vector<std::shared_ptr<lldb_private::StackFrame>, std::allocator<std::shared_ptr<lldb_private::StackFrame>>>>, lldb_private::StackID const&, __gnu_cxx::__ops::_Iter_comp_val<bool (*)(std::shared_ptr<lldb_private::StackFrame> const&, lldb_private::StackID const&)>) /mnt/gvfs/third-party2/libgcc/d1129753c8361ac8e9453c0f4291337a4507ebe6/11.x/platform010/5684a5a/include/c++/11.x/bits/stl_algobase.h:1464:8 llvm#12 0x00007fe9ebb6cdfc __gnu_cxx::__normal_iterator<std::shared_ptr<lldb_private::StackFrame>*, std::vector<std::shared_ptr<lldb_private::StackFrame>, std::allocator<std::shared_ptr<lldb_private::StackFrame>>>> std::lower_bound<__gnu_cxx::__normal_iterator<std::shared_ptr<lldb_private::StackFrame>*, std::vector<std::shared_ptr<lldb_private::StackFrame>, std::allocator<std::shared_ptr<lldb_private::StackFrame>>>>, lldb_private::StackID, bool (*)(std::shared_ptr<lldb_private::StackFrame> const&, lldb_private::StackID const&)>(__gnu_cxx::__normal_iterator<std::shared_ptr<lldb_private::StackFrame>*, std::vector<std::shared_ptr<lldb_private::StackFrame>, std::allocator<std::shared_ptr<lldb_private::StackFrame>>>>, __gnu_cxx::__normal_iterator<std::shared_ptr<lldb_private::StackFrame>*, std::vector<std::shared_ptr<lldb_private::StackFrame>, std::allocator<std::shared_ptr<lldb_private::StackFrame>>>>, lldb_private::StackID const&, bool (*)(std::shared_ptr<lldb_private::StackFrame> const&, lldb_private::StackID const&)) /mnt/gvfs/third-party2/libgcc/d1129753c8361ac8e9453c0f4291337a4507ebe6/11.x/platform010/5684a5a/include/c++/11.x/bits/stl_algo.h:2062:14 llvm#13 0x00007fe9ebb685fa auto llvm::lower_bound<std::vector<std::shared_ptr<lldb_private::StackFrame>, std::allocator<std::shared_ptr<lldb_private::StackFrame>>>&, lldb_private::StackID const&, bool (*)(std::shared_ptr<lldb_private::StackFrame> const&, lldb_private::StackID const&)>(std::vector<std::shared_ptr<lldb_private::StackFrame>, std::allocator<std::shared_ptr<lldb_private::StackFrame>>>&, lldb_private::StackID const&, bool (*)(std::shared_ptr<lldb_private::StackFrame> const&, lldb_private::StackID const&)) /home/hyubo/osmeta/external/llvm-project/llvm/include/llvm/ADT/STLExtras.h:2001:10 llvm#14 0x00007fe9ebb68441 lldb_private::StackFrameList::GetFrameWithStackID(lldb_private::StackID const&) /home/hyubo/osmeta/external/llvm-project/lldb/source/Target/StackFrameList.cpp:697:11 llvm#15 0x00007fe9ebbee395 lldb_private::Thread::GetFrameWithStackID(lldb_private::StackID const&) /home/hyubo/osmeta/external/llvm-project/lldb/include/lldb/Target/Thread.h:459:7 llvm#16 0x00007fe9ebac7cf7 lldb_private::ExecutionContextRef::GetFrameSP() const /home/hyubo/osmeta/external/llvm-project/lldb/source/Target/ExecutionContext.cpp:643:25 llvm#17 0x00007fe9ebac80e1 lldb_private::GetStoppedExecutionContext(lldb_private::ExecutionContextRef const*) /home/hyubo/osmeta/external/llvm-project/lldb/source/Target/ExecutionContext.cpp:164:34 llvm#18 0x00007fe9eb8903fa lldb_private::Statusline::Redraw(std::optional<lldb_private::ExecutionContextRef>) /home/hyubo/osmeta/external/llvm-project/lldb/source/Core/Statusline.cpp:139:7 llvm#19 0x00007fe9eb7ac8be lldb_private::Debugger::RedrawStatusline(std::optional<lldb_private::ExecutionContextRef>) /home/hyubo/osmeta/external/llvm-project/lldb/source/Core/Debugger.cpp:1233:3 llvm#20 0x00007fe9eb804d1e lldb_private::IOHandlerEditline::RedrawCallback() /home/hyubo/osmeta/external/llvm-project/lldb/source/Core/IOHandler.cpp:446:3 llvm#21 0x00007fe9eb80aa81 lldb_private::IOHandlerEditline::IOHandlerEditline(lldb_private::Debugger&, lldb_private::IOHandler::Type, std::shared_ptr<lldb_private::File> const&, std::shared_ptr<lldb_private::LockableStreamFile> const&, std::shared_ptr<lldb_private::LockableStreamFile> const&, unsigned int, char const*, llvm::StringRef, llvm::StringRef, bool, bool, unsigned int, lldb_private::IOHandlerDelegate&)::$_2::operator()() const /home/hyubo/osmeta/external/llvm-project/lldb/source/Core/IOHandler.cpp:262:73 llvm#22 0x00007fe9eb80aa5d void llvm::detail::UniqueFunctionBase<void>::CallImpl<lldb_private::IOHandlerEditline::IOHandlerEditline(lldb_private::Debugger&, lldb_private::IOHandler::Type, std::shared_ptr<lldb_private::File> const&, std::shared_ptr<lldb_private::LockableStreamFile> const&, std::shared_ptr<lldb_private::LockableStreamFile> const&, unsigned int, char const*, llvm::StringRef, llvm::StringRef, bool, bool, unsigned int, lldb_private::IOHandlerDelegate&)::$_2>(void*) /home/hyubo/osmeta/external/llvm-project/llvm/include/llvm/ADT/FunctionExtras.h:213:5 llvm#23 0x00007fe9eb93bfbf llvm::unique_function<void ()>::operator()() /home/hyubo/osmeta/external/llvm-project/llvm/include/llvm/ADT/FunctionExtras.h:365:5 llvm#24 0x00007fe9eb93bb80 lldb_private::Editline::GetCharacter(wchar_t*) /home/hyubo/osmeta/external/llvm-project/lldb/source/Host/common/Editline.cpp:0:5 llvm#25 0x00007fe9eb941a18 lldb_private::Editline::ConfigureEditor(bool)::$_0::operator()(editline*, wchar_t*) const /home/hyubo/osmeta/external/llvm-project/lldb/source/Host/common/Editline.cpp:1287:5 llvm#26 0x00007fe9eb9419e2 lldb_private::Editline::ConfigureEditor(bool)::$_0::__invoke(editline*, wchar_t*) /home/hyubo/osmeta/external/llvm-project/lldb/source/Host/common/Editline.cpp:1286:27 llvm#27 0x00007fe9f3384e26 el_getc /home/engshare/third-party2/libedit/3.1/src/libedit/src/read.c:439:14 llvm#28 0x00007fe9f3384e26 el_getc /home/engshare/third-party2/libedit/3.1/src/libedit/src/read.c:400:1 llvm#29 0x00007fe9f3384f90 read_getcmd /home/engshare/third-party2/libedit/3.1/src/libedit/src/read.c:247:14 llvm#30 0x00007fe9f3384f90 el_gets /home/engshare/third-party2/libedit/3.1/src/libedit/src/read.c:586:14 llvm#31 0x00007fe9eb9409f3 lldb_private::Editline::GetLine(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>&, bool&) /home/hyubo/osmeta/external/llvm-project/lldb/source/Host/common/Editline.cpp:1636:16 llvm#32 0x00007fe9eb8044d7 lldb_private::IOHandlerEditline::GetLine(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>&, bool&) /home/hyubo/osmeta/external/llvm-project/lldb/source/Core/IOHandler.cpp:339:5 llvm#33 0x00007fe9eb805609 lldb_private::IOHandlerEditline::Run() /home/hyubo/osmeta/external/llvm-project/lldb/source/Core/IOHandler.cpp:600:11 llvm#34 0x00007fe9eb7b214c lldb_private::Debugger::RunIOHandlers() /home/hyubo/osmeta/external/llvm-project/lldb/source/Core/Debugger.cpp:1280:16 llvm#35 0x00007fe9eb98f00f lldb_private::CommandInterpreter::RunCommandInterpreter(lldb_private::CommandInterpreterRunOptions&) /home/hyubo/osmeta/external/llvm-project/lldb/source/Interpreter/CommandInterpreter.cpp:3620:16 llvm#36 0x00007fe9eb4f0e09 lldb::SBDebugger::RunCommandInterpreter(bool, bool) /home/hyubo/osmeta/external/llvm-project/lldb/source/API/SBDebugger.cpp:1234:42 llvm#37 0x000055ca6788d6b0 Driver::MainLoop() /home/hyubo/osmeta/external/llvm-project/lldb/tools/driver/Driver.cpp:677:3 llvm#38 0x000055ca6788e226 main /home/hyubo/osmeta/external/llvm-project/lldb/tools/driver/Driver.cpp:887:17 llvm#39 0x00007fe9e5e2c657 __libc_start_call_main /home/engshare/third-party2/glibc/2.34/src/glibc-2.34/csu/../sysdeps/nptl/libc_start_call_main.h:58:16 llvm#40 0x00007fe9e5e2c718 call_init /home/engshare/third-party2/glibc/2.34/src/glibc-2.34/csu/../csu/libc-start.c:128:20 llvm#41 0x00007fe9e5e2c718 __libc_start_main@GLIBC_2.2.5 /home/engshare/third-party2/glibc/2.34/src/glibc-2.34/csu/../csu/libc-start.c:379:5 llvm#42 0x000055ca67889a11 _start /home/engshare/third-party2/glibc/2.34/src/glibc-2.34/csu/../sysdeps/x86_64/start.S:118:0 Segmentation fault (core dumped) ``` When `target symbols add` is run, `Symtab::AddSymbol()` can reallocate the underlying `std::vector<Symbol>` and resize it, invalidating all existing Symbol* pointers. While `Process::Flush()` clears stale stack frames, the statusline caches its own `ExecutionContextRef` containing a `StackID` with a `SymbolContextScope*` (which can be a `Symbol*`). This cached reference is not cleared by `Process::Flush()`, so the next statusline redraw accesses a dangling pointer and crashes. Fix this by adding `Statusline::Flush()` which clears the cached frame, `Debugger::Flush()` which forwards to it under the statusline mutex, and calling `Debugger::Flush()` from `Process::Flush()` so that all flush paths (symbol add, exec, module load) also invalidate the statusline's stale state. After this fix, lldb is not crashing anymore, new symbols from a symbol file are correctly loaded --------- Co-authored-by: George Hu <georgehuyubo@gmail.com>

llvm#183506 revealed a pre-existing use-after-scope in createInstrInfo (MSan bot: https://lab.llvm.org/buildbot/#/builders/164/builds/21562 [*]). This patch fixes the issue by changing the stack-allocated AArch64Subtarget (which goes out of scope once createInstrInfo() returns) into heap-allocated, allowing it to be safely stored in the returned AArch64InstrInfo. ----- [*] WARNING: MemorySanitizer: use-of-uninitialized-value #0 0x55555666fabd in llvm::AArch64InstrInfo::getInstSizeInBytes(llvm::MachineInstr const&) const /home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/llvm/lib/Target/AArch64/AArch64InstrInfo.cpp:247:5 ... /home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/llvm/unittests/Target/AArch64/InstSizes.cpp:85:3 llvm#9 0x555556508559 in InstSizes_MOVaddrTagged_Test::TestBody() /home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/llvm/unittests/Target/AArch64/InstSizes.cpp:301:3 ... Member fields were destroyed #0 0x555556498a1d in __sanitizer_dtor_callback_fields /home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/compiler-rt/lib/msan/msan_interceptors.cpp:1074:5 #1 0x5555564fbda6 in ~Triple /home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/llvm/include/llvm/TargetParser/Triple.h:348:12 #2 0x5555564fbda6 in ~Triple /home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/llvm/include/llvm/TargetParser/Triple.h:47:7 #3 0x5555564fbda6 in llvm::AArch64Subtarget::~AArch64Subtarget() /home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/llvm/lib/Target/AArch64/AArch64Subtarget.h:38:7 llvm#4 0x555556503396 in (anonymous namespace)::createInstrInfo(llvm::TargetMachine*) /home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/llvm/unittests/Target/AArch64/InstSizes.cpp:38:1 llvm#5 0x5555565084cb in InstSizes_MOVaddrTagged_Test::TestBody() /home/b/sanitizer-x86_64-linux-bootstrap-msan/build/llvm-project/llvm/unittests/Target/AArch64/InstSizes.cpp:299:42

Stylie777 added 2 commits December 19, 2025 10:52

[Flang][OpenMP] Rework bounds in Taskloop lowering

de7fff6

Updates to bounds rework

b30007a

- Force the first 3 entries to the StructArg to be the bounds info - Ensure it will work when executing the tasks in parallel

tblah reviewed Dec 19, 2025

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kaviya2510 reviewed Dec 22, 2025

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tblah added a commit to tblah/llvm-project that referenced this pull request Jan 5, 2026

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tblah added a commit to llvm/llvm-project that referenced this pull request Jan 5, 2026

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tblah added a commit to llvm/llvm-project that referenced this pull request Jan 7, 2026

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Stylie777 closed this Feb 11, 2026

-                        const Twine &Name = "", bool AsPtr = true, bool Is64Bit = false) {
+                        const Twine &Name = "", bool AsPtr = true, IntegerType *IntTy) {
+Builder.restoreIP(OuterAllocaIP);
+IntTy = IntTy ? IntTy : Builder.getInt32Ty();

	"lb", false, true);
	"lb", /AsPtr=/false, Builder.getInt64Ty());

		@@ -2015,20 +2033,18 @@ OpenMPIRBuilder::InsertPointOrErrorTy OpenMPIRBuilder::createTaskloop(
		Value *TaskSize = Builder.getInt64(
		divideCeil(M.getDataLayout().getTypeSizeInBits(Taskloop), 8));

	Builder.CreateStore(CastedLBVal, Lb);
	auto *Idx0 = Builder.getInt32(0);
	llvm::Value *Lb = Builder.CreateGEP(ArgStructType, TaskShareds, {Idx0, Builder.getInt32(0)});

	llvm::Value *Ub = Builder.CreateStructGEP(ArgStructType, TaskShareds, 1);
	llvm::Value *Ub =Builder.CreateGEP(ArgStructType, TaskShareds, {Idx0, Builder.getInt32(1)});

	llvm::Value *Step = Builder.CreateStructGEP(ArgStructType, TaskShareds, 2);
	llvm::Value *Step =Builder.CreateGEP(ArgStructType, TaskShareds, {Idx0, Builder.getInt32(2)});

		@@ -2127,12 +2161,15 @@ OpenMPIRBuilder::InsertPointOrErrorTy OpenMPIRBuilder::createTaskloop(
		if (Add->getOpcode() == llvm::Instruction::Add) {

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kaviya2510 Dec 22, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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kaviya2510 Dec 22, 2025 •

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