AFAR offload runtime at HSA_XNACK=1: omp_target_is_present returns false after target enter data, and map(present) of an absent item does not terminate

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

Same issue as afar-xnack1-target-is-present; 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	correct	unknown not run	correct	correct	n/a	n/a
CCE 19.0.0	correct	correct	unknown not run	unknown not run	unknown not run	n/a	n/a
CCE 20.0.2	correct	correct	unknown not run	unknown not run	unknown not run	n/a	n/a
CCE 21.0.3	correct	correct	unknown not run	unknown not run	unknown not run	n/a	n/a
CCE 21.0.4	correct	correct	unknown not run	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	show reached the end: b1= 2
fails another way	NVHPC 25.11, A100 separate NVHPC 25.11, A100 managed NVHPC 26.9, A100 separate NVHPC 26.9, A100 managed	show NVFORTRAN-S-0034-Syntax error at or near : (afar-xnack1-present-not-enforced.f90: 6) 0 inform, 0 warnings, 1 severes, 0 fatal for p

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 (runs correctly)

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

Program (30 lines)

! (copy mode for the whole catalog): AFAR does not perform the
! runtime error termination of the present map-type-modifier at
! HSA_XNACK=1 (unified memory).
! a was never mapped, so on entry to the region it is not present and
! "runtime error termination is performed" (5.2 §5.8.3 p.152); the
! program has no requires directive, so unified memory does not change
! the rule.
! Expected: an error termination before the end (no "reached the end").
! Observed (tuolumne, MI300A, 2026-10-22, 3 runs each, -O2,
! OMP_TARGET_OFFLOAD=mandatory):
! - AFAR amdflang 24.0.0git at HSA_XNACK=1: "reached the end: b1= 2" (the
!   region runs on the shared data); at HSA_XNACK=0: "omptarget message:
!   device mapping required by 'present' map type modifier does not exist"
!   and error termination, as required. AFAR amdclang (C programs) the same.
! - CCE 19.0.0, 20.0.2, 21.0.3: error termination in both modes ("Variable
!   not found in present table").
! The catalog's map.present negative probes (Fortran and C, 5.2 and 6.0)
! read wrong at HSA_XNACK=1 and correct at HSA_XNACK=0 on AFAR.
! AFAR: amdflang -fopenmp --offload-arch=gfx942 -O2
! Run:  OMP_TARGET_OFFLOAD=mandatory HSA_XNACK=1 ./a.out
program p
  implicit none
  integer :: a(64), b(64)
  a = 1
  b = 0
  !$omp target map(present, to: a) map(from: b)
    b = a + 1
  !$omp end target
  print *, 'reached the end: b1=', b(1)
end program p

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

 reached the end: b1= 2

What the specification requires

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

OpenMP 5.2 §5.8.3 p.152

runtime error termination is performed

Evidence

Same compiler, one change

run at HSA_XNACK=0: 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 p
  implicit none
  integer :: a(64), b(64)
  a = 1
  b = 0
  !$omp target map(present, to: a) map(from: b)
    b = a + 1
  !$omp end target
  print *, 'reached the end: b1=', b(1)
end program p

Other compilers run it correctly

CCE 19.0.0, CCE 20.0.2, CCE 21.0.3, CCE 21.0.4, GCC 16.2.0