Constructs documented as unsupported in offload regions (single, masked, task, ordered, scan) give internal compiler errors or device link failures instead of a diagnostic

Legality: not independently confirmed. no independent review yet How this is checked

Same issue as cce19-target-parallel-single-ice; this program is another reproducer of it.

Affected variants

Compiler	MI300A gfx942 unified memory (XNACK 1)	MI300A gfx942 copy (XNACK 0)	MI250X gfx90a copy (XNACK 0)	MI300X gfx942 copy (XNACK 0)	MI350X gfx950 copy (XNACK 0)	A100 sm_80 separate memory	A100 sm_80 managed memory
AFAR 24.3.0	behaves incorrectly	behaves incorrectly	behaves incorrectly	behaves incorrectly	behaves incorrectly	n/a	n/a
CCE 19.0.0	behaves incorrectly	behaves incorrectly	behaves incorrectly	unknown not run	unknown not run	n/a	n/a
CCE 20.0.2	behaves incorrectly	behaves incorrectly	behaves incorrectly	unknown not run	unknown not run	n/a	n/a
CCE 21.0.3	behaves incorrectly	behaves incorrectly	behaves incorrectly	unknown not run	unknown not run	n/a	n/a
CCE 21.0.4	behaves incorrectly	behaves incorrectly	behaves incorrectly	unknown not run	unknown not run	n/a	n/a
NVHPC 25.11	n/a	n/a	n/a	n/a	n/a	fails another way	fails another way
NVHPC 26.9	n/a	n/a	n/a	n/a	n/a	fails another way	fails another way
GCC 16.2.0	correct	correct	correct	correct	correct	correct	n/a

"behaves incorrectly" / "not supported": this issue, confirmed in up to four environments (another build directory, another node, a repeat). "fails another way": a different failure, not counted as this issue. "unknown": not run there, or the runs disagree.

Messages

Result	Compiler and GPU	Message
behaves incorrectly	AFAR 24.3.0, MI300A unified AFAR 24.3.0, MI300A copy	show 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: $AFAR/lib/llvm/bin/flang-24 -fc1 -triple amdgpu9.42-amd-amdhsa -emit-llvm-bc -fno-color-diagnostics -flto=full -mrelocation-model pic -pic-level 2 -target-cpu gfx942 -mlink-built #0 0x0000155543273e6a llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) ($AFAR/lib/llvm/bin/../lib/libLLVM.so.24.0git+0x88ce6a) #1 0x0000155543270b46 SignalHandler(int, siginfo_t, void) Signals.cpp:0:0 #2 0x0000155555116990 __restore_rt (/lib64/libpthread.so.0+0x12990) #3 0x000015554342e595 llvm::AllocaInst::getAllocationSize(llvm::DataLayout const&) const ($AFAR/lib/llvm/bin/../lib/libLLVM.so.24.0git+0xa47595) #4 0x0000155544337aa7 llvm::OpenMPIRBuilder::createTask(llvm::OpenMPIRBuilder::LocationDescription const&, llvm::IRBuilderBase::InsertPoint, llvm::ArrayRef<llvm::BasicBlock*>, llvm::function_ref<llvm
behaves incorrectly	AFAR 24.3.0, MI250X	show 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: $AFAR/lib/llvm/bin/flang-24 -fc1 -triple amdgpu9.0a-amd-amdhsa -emit-llvm-bc -fno-color-diagnostics -flto=full -mrelocation-model pic -pic-level 2 -target-cpu gfx90a -mlink-built #0 0x0000155543273e6a llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) ($AFAR/lib/llvm/lib/libLLVM.so.24.0git+0x88ce6a) #1 0x0000155543270b46 SignalHandler(int, siginfo_t, void) Signals.cpp:0:0 #2 0x0000155555116990 __restore_rt (/lib64/libpthread.so.0+0x12990) #3 0x000015554342e595 llvm::AllocaInst::getAllocationSize(llvm::DataLayout const&) const ($AFAR/lib/llvm/lib/libLLVM.so.24.0git+0xa47595) #4 0x0000155544337aa7 llvm::OpenMPIRBuilder::createTask(llvm::OpenMPIRBuilder::LocationDescription const&, llvm::IRBuilderBase::InsertPoint, llvm::ArrayRef<llvm::BasicBlock*>, llvm::function_ref<llvm
behaves incorrectly	AFAR 24.3.0, MI300X	show 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: $AFAR/lib/llvm/bin/flang-24 -fc1 -triple amdgpu9.42-amd-amdhsa -emit-llvm-bc -fno-color-diagnostics -flto=full -mrelocation-model pic -pic-level 2 -target-cpu gfx942 -mlink-built #0 0x00007f352428ce6a llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) $AFAR/lib/llvm/lib/libLLVM.so.24.0git+0x88ce6a) #1 0x00007f3524289b46 SignalHandler(int, siginfo_t, void) Signals.cpp:0:0 #2 0x00007f352323ebf0 __restore_rt (/lib64/libc.so.6+0x3ebf0) #3 0x00007f3524447595 llvm::AllocaInst::getAllocationSize(llvm::DataLayout const&) const $AFAR/lib/llvm/lib/libLLVM.so.24.0git+0xa47595) #4 0x00007f3525350aa7 llvm::OpenMPIRBuilder::createTask(llvm::OpenMPIRBuilder::LocationDescription const&, llvm::IRBuilderBase::InsertPoint, llvm::ArrayRef<llvm::BasicBlock*>, llvm::function_ref<llvm
behaves incorrectly	AFAR 24.3.0, MI350X	show 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: $AFAR/lib/llvm/bin/flang-24 -fc1 -triple amdgpu9.50-amd-amdhsa -emit-llvm-bc -fno-color-diagnostics -flto=full -mrelocation-model pic -pic-level 2 -target-cpu gfx950 -mlink-built #0 0x00007fda40c8ce6a llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) $AFAR/lib/llvm/lib/libLLVM.so.24.0git+0x88ce6a) #1 0x00007fda40c89b46 SignalHandler(int, siginfo_t, void) Signals.cpp:0:0 #2 0x00007fda3fc3fc30 __restore_rt (/lib64/libc.so.6+0x3fc30) #3 0x00007fda40e47595 llvm::AllocaInst::getAllocationSize(llvm::DataLayout const&) const $AFAR/lib/llvm/lib/libLLVM.so.24.0git+0xa47595) #4 0x00007fda41d50aa7 llvm::OpenMPIRBuilder::createTask(llvm::OpenMPIRBuilder::LocationDescription const&, llvm::IRBuilderBase::InsertPoint, llvm::ArrayRef<llvm::BasicBlock*>, llvm::function_ref<llvm
behaves incorrectly	CCE 19.0.0, MI300A unified CCE 19.0.0, MI300A copy CCE 19.0.0, MI250X	show Warning: Headers and libraries from cray-libsci/25.03.0 will be ignored because depends on PE_MPICH which is unavailable.. MT_CONTEXT_TASKWAIT Error message :: unhandled construct type Error detected :: File '/workspace/crayftn/pdgcs/v_openmp.c', line 7617 Initiated from :: Line 660 (v_main.c) Optimizer built :: 2025-02-07 (production) File :: afar-cce19-task-in-target-ice.f90
behaves incorrectly	CCE 20.0.2, MI300A unified CCE 20.0.2, MI300A copy CCE 20.0.2, MI250X	show Warning: Headers and libraries from cray-libsci/25.09.0 will be ignored because depends on PE_MPICH which is unavailable.. MT_CONTEXT_TASKWAIT Error message :: unhandled construct type Error detected :: File '/workspace/crayftn/pdgcs/v_openmp.c', line 7814 Initiated from :: Line 660 (v_main.c) Optimizer built :: 2025-11-17 (production) File :: afar-cce19-task-in-target-ice.f90
behaves incorrectly	CCE 21.0.3, MI300A unified CCE 21.0.3, MI300A copy CCE 21.0.3, MI250X	show Warning: Headers and libraries from cray-libsci/26.03.0 will be ignored because depends on PE_MPICH which is unavailable.. MT_CONTEXT_TASKWAIT Error message :: unhandled construct type Error detected :: File '/workspace/crayftn/pdgcs/v_openmp.c', line 8197 Initiated from :: Line 732 (v_main.c) Optimizer built :: 2026-07-14 (production) File :: afar-cce19-task-in-target-ice.f90
behaves incorrectly	CCE 21.0.4, MI300A unified CCE 21.0.4, MI300A copy CCE 21.0.4, MI250X	show Warning: Headers and libraries from cray-libsci/26.03.0 will be ignored because depends on PE_MPICH which is unavailable.. MT_CONTEXT_TASKWAIT Error message :: unhandled construct type Error detected :: File '/workspace/crayftn/pdgcs/v_openmp.c', line 8197 Initiated from :: Line 732 (v_main.c) Optimizer built :: 2026-09-24 (production) File :: afar-cce19-task-in-target-ice.f90
fails another way	NVHPC 25.11, A100 separate NVHPC 25.11, A100 managed	show NVFORTRAN-F-1196-OpenMP - omp task is not supported in GPU region (afar-cce19-task-in-target-ice.f90: 7) NVFORTRAN/x86-64 Linux 25.11-0: compilation aborted
fails another way	NVHPC 26.9, A100 separate NVHPC 26.9, A100 managed	show NVFORTRAN-F-1196-OpenMP - omp task is not supported in GPU region (afar-cce19-task-in-target-ice.f90: 7) NVFORTRAN/x86-64 Linux 26.9-0: compilation aborted

Reproduce

AFAR 24.3.0, MI300A unified

$AFAR/bin/amdflang -fopenmp --offload-arch=gfx942 -O2 repro.f90 -o repro
HSA_XNACK=1 OMP_TARGET_OFFLOAD=mandatory ./repro

CCE 19.0.0, MI300A unified

module load cce/19.0.0 craype-accel-amd-gfx942 rocm/6.4.3
module unload cray-mpich
ftn -fopenmp -O2 repro.f90 -o repro
HSA_XNACK=1 OMP_TARGET_OFFLOAD=mandatory ./repro

CCE 20.0.2, MI300A unified

module load cce/20.0.2 craype-accel-amd-gfx942 rocm/6.4.3
module unload cray-mpich
ftn -fopenmp -O2 repro.f90 -o repro
HSA_XNACK=1 OMP_TARGET_OFFLOAD=mandatory ./repro

CCE 21.0.3, MI300A unified

module load cce/21.0.3 craype-accel-amd-gfx942 rocm/7.2.0
module unload cray-mpich
ftn -fopenmp -O2 repro.f90 -o repro
HSA_XNACK=1 OMP_TARGET_OFFLOAD=mandatory ./repro

CCE 21.0.4, MI300A unified

module load cce/21.0.4 craype-accel-amd-gfx942 rocm/7.2.0
module unload cray-mpich
ftn -fopenmp -O2 repro.f90 -o repro
HSA_XNACK=1 OMP_TARGET_OFFLOAD=mandatory ./repro

GCC 16.2.0, MI300A unified (runs correctly)

export LD_LIBRARY_PATH=$GCC_16_2/lib64:/opt/rocm-7.2.1/lib
$GCC_16_2/bin/gfortran -fopenmp -foffload=amdgcn-amdhsa -foffload-options=amdgcn-amdhsa=-march=gfx942 -O2 repro.f90 -o repro
HSA_XNACK=1 OMP_TARGET_OFFLOAD=mandatory ./repro

Program (14 lines)

program t
  implicit none
  integer :: c, r
  r = 0
  !$omp target map(from: r)
    c = 7
    !$omp task default(shared)
      c = 42
    !$omp end task
    !$omp taskwait
    r = c
  !$omp end target
  print *, 'r=', r
end program

Source in the repository

Something to add? Dispute its legality · Report it fixed in a newer release · Report a mistake on this page

Expected and observed

Observed where it behaves incorrectly

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: $AFAR/lib/llvm/bin/flang-24 -fc1 -triple amdgpu9.42-amd-amdhsa -emit-llvm-bc -fno-color-diagnostics -flto=full -mrelocation-model pic -pic-level 2 -target-cpu gfx942 -mlink-built
 #0 0x0000155543273e6a llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) ($AFAR/lib/llvm/bin/../lib/libLLVM.so.24.0git+0x88ce6a)
 #1 0x0000155543270b46 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
 #2 0x0000155555116990 __restore_rt (/lib64/libpthread.so.0+0x12990)
 #3 0x000015554342e595 llvm::AllocaInst::getAllocationSize(llvm::DataLayout const&) const ($AFAR/lib/llvm/bin/../lib/libLLVM.so.24.0git+0xa47595)
 #4 0x0000155544337aa7 llvm::OpenMPIRBuilder::createTask(llvm::OpenMPIRBuilder::LocationDescription const&, llvm::IRBuilderBase::InsertPoint, llvm::ArrayRef<llvm::BasicBlock*>, llvm::function_ref<llvm

What the specification requires

The specification text this program relies on and the compiler is expected to support.

The same requirement as the issue cce19-target-parallel-single-ice.

OpenMP 5.2 §11.1 p.241 l.2-3

The single construct specifies that the associated structured block is executed by only one of the threads in the team

OpenMP 5.2 §11.1 p.241 l.5-6

An implicit barrier occurs at the end of a single region if the nowait clause is not specified.

Evidence

Same compiler, one change

the task and taskwait constructs removed (the task body kept): AFAR 24.3.0: correct; CCE 19.0.0: correct; CCE 20.0.2: correct; CCE 21.0.3: correct; CCE 21.0.4: correct
Control program
```
program t
  implicit none
  integer :: c, r
  r = 0
  !$omp target map(from: r)
    c = 7
      c = 42
    r = c
  !$omp end target
  print *, 'r=', r
end program
```

Other compilers run it correctly

GCC 16.2.0