Observed issues › oop/nvhpc-polymorphism-runtime-unsupported
SELECT TYPE, CLASS(*) and finalization are not supported in device code
Legality: independently confirmed. 2 independent readings find the program legal and the result required. How this is checked
SELECT TYPE on a CLASS dummy, a CLASS(*) dummy and the finalization of a local object in declare target procedures are rejected by NVHPC 25.11 and 26.9: the compiler reports the runtime routines they need as not supported on the device (NVHPC's own message; its guide does not mention these features). AFAR runs all six programs correctly.
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 | correct | correct | unknown not run | correct | correct | n/a | n/a |
| CCE 19.0.0 | fails another way | fails another way | unknown not run | unknown not run | unknown not run | n/a | n/a |
| CCE 20.0.2 | fails another way | fails another way | unknown not run | unknown not run | unknown not run | n/a | n/a |
| CCE 21.0.3 | fails another way | fails another way | unknown not run | unknown not run | unknown not run | n/a | n/a |
| CCE 21.0.4 | fails another way | fails another way | 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 | not supported | not supported |
| NVHPC 26.9 | n/a | n/a | n/a | n/a | n/a | not supported | not supported |
| GCC 16.2.0 | fails another way | fails another way | fails another way | fails another way | fails another way | fails another way | 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 |
|---|---|---|
| not supported | NVHPC 25.11, A100 separate NVHPC 25.11, A100 managed NVHPC 26.9, A100 separate NVHPC 26.9, A100 managed | showNVFORTRAN-S-1058-Call to Compiler runtime function not supported - pgf90_same_type_as_i8 (site-oop--nvhpc-polymorphism-runtime-unsupported.f90: 35) 0 inform, 0 warnings, 1 severes, 0 fatal for bump |
| fails another way | CCE 19.0.0, MI300A unified CCE 19.0.0, MI300A copy CCE 20.0.2, MI300A unified CCE 20.0.2, MI300A copy CCE 21.0.3, MI300A unified CCE 21.0.3, MI300A copy CCE 21.0.4, MI300A unified CCE 21.0.4, MI300A copy | showr1= 0 r2= 0 r3= -1 RESULT ran_on_host=0 check=fail |
| fails another way | GCC 16.2.0, MI300A unified GCC 16.2.0, MI300A copy | showsite-oop--nvhpc-polymorphism-runtime-unsupported.f90:46:16: error: variable ‘__vtab_oop_m_Ext1’ has been referenced in offloaded code but hasn’t been marked to be included in the offloaded code
46 | end module oop_m
| ^
site-oop--nvhpc-polymorphism-runtime-unsupported.f90:46:16: error: variable ‘__vtab_oop_m_Ext2’ has been referenced in offloaded code but hasn’t been marked to be included in the offloaded code
lto1: fatal error: errors during merging of translation units
compilation terminated.
gcn mkoffload: fatal error: <home>/gcc-16.2/bin/x86_64-pc-linux-gnu-accel-amdgcn-amdhsa-gcc returned 1 exit status
compilation terminated. |
| fails another way | GCC 16.2.0, MI250X | showsite-oop--nvhpc-polymorphism-runtime-unsupported.f90:44:16: error: variable ‘__vtab_oop_m_Ext1’ has been referenced in offloaded code but hasn’t been marked to be included in the offloaded code
44 | end module oop_m
| ^
site-oop--nvhpc-polymorphism-runtime-unsupported.f90:44:16: error: variable ‘__vtab_oop_m_Ext2’ has been referenced in offloaded code but hasn’t been marked to be included in the offloaded code
lto1: fatal error: errors during merging of translation units
compilation terminated.
gcn mkoffload: fatal error: <home>/gcc-16.2/bin/x86_64-pc-linux-gnu-accel-amdgcn-amdhsa-gcc returned 1 exit status
compilation terminated. |
| fails another way | GCC 16.2.0, MI300X GCC 16.2.0, MI350X | showsite-oop--nvhpc-polymorphism-runtime-unsupported.f90:46:16: error: variable ‘__vtab_oop_m_Ext1’ has been referenced in offloaded code but hasn’t been marked to be included in the offloaded code
46 | end module oop_m
| ^
site-oop--nvhpc-polymorphism-runtime-unsupported.f90:46:16: error: variable ‘__vtab_oop_m_Ext2’ has been referenced in offloaded code but hasn’t been marked to be included in the offloaded code
lto1: fatal error: errors during merging of translation units
compilation terminated.
gcn mkoffload: fatal error: <home>/<user>/gcc-16.2/bin/x86_64-pc-linux-gnu-accel-amdgcn-amdhsa-gcc returned 1 exit status
compilation terminated. |
| fails another way | GCC 16.2.0, A100 separate | showsite-oop--nvhpc-polymorphism-runtime-unsupported.f90:44:16: error: variable ‘__vtab_oop_m_Ext1’ has been referenced in offloaded code but hasn’t been marked to be included in the offloaded code
44 | end module oop_m
| ^
site-oop--nvhpc-polymorphism-runtime-unsupported.f90:44:16: error: variable ‘__vtab_oop_m_Ext2’ has been referenced in offloaded code but hasn’t been marked to be included in the offloaded code
lto1: fatal error: errors during merging of translation units
compilation terminated.
nvptx mkoffload: fatal error: <home>/gcc-16.2/bin/x86_64-pc-linux-gnu-accel-nvptx-none-gcc returned 1 exit status
compilation terminated. |
Reproduce
NVHPC 25.11, A100 separate
export LD_LIBRARY_PATH=$NVHPC_25_11/compilers/lib nvfortran -mp=gpu -gpu=cc80 -gpu=mem:separate -O2 repro.f90 -o repro OMP_TARGET_OFFLOAD=mandatory ./repro
NVHPC 26.9, A100 separate
export LD_LIBRARY_PATH=$NVHPC_26_9/compilers/lib nvfortran -mp=gpu -gpu=cc80 -gpu=mem:separate -O2 repro.f90 -o repro OMP_TARGET_OFFLOAD=mandatory ./repro
AFAR 24.3.0, MI300A unified (runs correctly)
$AFAR/bin/amdflang -fopenmp --offload-arch=gfx942 -O2 repro.f90 -o repro HSA_XNACK=1 OMP_TARGET_OFFLOAD=mandatory ./repro
Program (88 lines)
! # Finding (fortran-oop): SELECT TYPE, CLASS(*) and finalization in device code: 'runtime function not supported'
!
! - toolchains and modes that fail: nvhpc (NVHPC 25.11: managed, separate), nvhpc269 (NVHPC 26.9: managed, separate); -O2
! - build: nvfortran -mp=gpu -gpu=cc80 -O2 (managed: -gpu=mem:managed)
! - failure: rejected (not_implemented); OMP_TARGET_OFFLOAD=mandatory
! - observed: `NVFORTRAN-S-1058-Call to Compiler runtime function not supported - pgf90_same_type_as_i8` (SELECT TYPE),
! `pgf90_init_unl_poly_desc_i8` (CLASS(*)), `pgf90_finalize_i8` (finalization), NVHPC 25.11 and 26.9, both modes.
! oop-assignfinal-final-dealloc fails on the ALLOCATE instead (`pgf90_calloc04a_i8`): not counted here. The claim rests on
! NVHPC's own messages; its user guide does not mention these features in device code
! - expected: compiles; `r1= 10 r2= 100 r3= -1`
! - rule: Fortran 2018 11.1.11, 7.5.6.3; no OpenMP restriction (section 6)
! - other families: AFAR correct on all six; CCE takes the wrong SELECT TYPE branch (cce-select-type-guard-not-taken.f90); GCC
! rejects SELECT TYPE (gcc-vtab-not-marked-for-offload.f90)
! - gate and confirmer: 24 cells, 24 confirmed in the gate's four environments (a-d; results/oop/main/gate_reruns*.jsonl);
! confirmer (results/oop/main/confirm.jsonl): unsupported (R05-unsupported) 24
! - programs (6): oop-poly-select-type, oop-poly-class-is, oop-unlimited-select-type, oop-unlimited-classify,
! oop-assignfinal-final-local, oop-assignfinal-final-assign (offload/engine/oop_gen.py; this file is the first one)
! - legality: for the nvhpc cells: the rules (offload.engine.rules, with the fortran-oop restrictions) and AFAR's flang front end
! (-fsyntax-only) and a CCE compile (tools/campaigns/oop.py legality,
! results/oop/main/legality.json)
module oop_m
implicit none
integer, parameter :: n = 64
type base_t
integer :: a = 0
end type base_t
type, extends(base_t) :: ext1
integer :: u = 0
end type ext1
type, extends(base_t) :: ext2
integer :: v = 0
end type ext2
contains
subroutine bump(s)
!$omp declare target
class(base_t), intent(inout) :: s
select type (s)
type is (ext1)
s%u = s%u + 10
type is (ext2)
s%v = s%v + 100
class default
s%a = -1
end select
end subroutine bump
end module oop_m
program oop
use omp_lib
use oop_m
implicit none
integer :: host_flag
logical :: ok
integer :: r1, r2, r3
type(ext1) :: e1
type(ext2) :: e2
type(base_t) :: b0
host_flag = 1
!$omp target map(from: host_flag)
host_flag = merge(1, 0, omp_is_initial_device())
!$omp end target
!$omp target map(tofrom: e1, e2, b0)
call bump(e1)
call bump(e2)
call bump(b0)
!$omp end target
r1 = e1%u
r2 = e2%v
r3 = b0%a
ok = .true.
ok = ok .and. (r1 == 10)
ok = ok .and. (r2 == 100)
ok = ok .and. (r3 == -1)
print '(a,i0)', 'r1= ', r1
print '(a,i0)', 'r2= ', r2
print '(a,i0)', 'r3= ', r3
print '(a,i0,a,a)', 'RESULT ran_on_host=', host_flag, ' check=', merge('pass', 'fail', ok)
end program oop
! spec (requirement): the base language is Fortran 2003, 2008 and 2018 with only a short list of features of unspecified
! behavior (SELECT TYPE, CLASS(*) and finalization are not on it; their semantics are the Fortran standard's, with no OpenMP
! text of their own), and a declare target procedure must be executable on a device.
! "While future versions of the OpenMP specification are expected to address the following features, currently their use may
! result in unspecified behavior." (5.2 §1.7 p.36 l.6-8)
! "Declare target directives apply to procedures and/or variables to ensure that they can be executed or accessed on a device."
! (5.2 §7.8 p.204 l.16-17)
! spec (this program): bump is a declare target subroutine with a CLASS dummy and SELECT TYPE called in a target region; NVHPC
! rejects it with 'Call to Compiler runtime function not supported - pgf90_same_type_as_i8', so the procedure cannot be executed
! on the device. The same message appears for CLASS(*) and for finalization of a local object.
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
NVFORTRAN-S-1058-Call to Compiler runtime function not supported - pgf90_same_type_as_i8 (site-oop--nvhpc-polymorphism-runtime-unsupported.f90: 35) 0 inform, 0 warnings, 1 severes, 0 fatal for bump
What the specification requires
The specification text this program relies on and the compiler is expected to support.
OpenMP 5.2 §1.7 p.36 l.6-8
While future versions of the OpenMP specification are expected to address the following features, currently their use may result in unspecified behavior.
OpenMP 5.2 §7.8 p.204 l.16-17
Declare target directives apply to procedures and/or variables to ensure that they can be executed or accessed on a device.
Evidence
Other compilers run it correctly
AFAR 24.3.0