Declare target to(f) rejected ("unexpected 'to' clause, use 'enter' instead")

Legality: independently confirmed. 2 independent readings find the program legal and the result required. How this is checked

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	not supported	not supported	not supported	not supported	not supported	n/a	n/a
CCE 19.0.0	not supported	not supported	not supported	unknown not run	unknown not run	n/a	n/a
CCE 20.0.2	not supported	not supported	not supported	unknown not run	unknown not run	n/a	n/a
CCE 21.0.3	not supported	not supported	not supported	unknown not run	unknown not run	n/a	n/a
CCE 21.0.4	not supported	not supported	not supported	unknown not run	unknown not run	n/a	n/a
NVHPC 25.11	n/a	n/a	n/a	n/a	n/a	correct	correct
NVHPC 26.9	n/a	n/a	n/a	n/a	n/a	correct	correct
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
not supported	AFAR 24.3.0, MI300A unified AFAR 24.3.0, MI300A copy AFAR 24.3.0, MI250X AFAR 24.3.0, MI300X AFAR 24.3.0, MI350X CCE 19.0.0, MI300A unified CCE 19.0.0, MI300A copy CCE 19.0.0, MI250X CCE 20.0.2, MI300A unified CCE 20.0.2, MI300A copy CCE 20.0.2, MI250X CCE 21.0.3, MI300A unified CCE 21.0.3, MI300A copy CCE 21.0.3, MI250X CCE 21.0.4, MI300A unified CCE 21.0.4, MI300A copy CCE 21.0.4, MI250X	show clang-c-declare-target-to-omp52.c:5:28: error: unexpected 'to' clause, use 'enter' instead 5 \| #pragma omp declare target to(f) device_type(any) \| ^ clang-c-declare-target-to-omp52.c:5:21: error: expected at least one 'enter', 'link' or 'indirect' clause 5 \| #pragma omp declare target to(f) device_type(any) \| ^ 2 errors generated.

Reproduce

AFAR 24.3.0, MI300A unified

$AFAR/bin/amdclang -fopenmp --offload-arch=gfx942 -fopenmp-version=52 -fopenmp-version=52 -O2 repro.c -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
craycc -fopenmp -fopenmp-targets=amdgcn-amd-amdhsa -Xopenmp-target=amdgcn-amd-amdhsa -march=gfx942 -fopenmp-version=52 -O2 repro.c -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
craycc -fopenmp -fopenmp-targets=amdgcn-amd-amdhsa -Xopenmp-target=amdgcn-amd-amdhsa -march=gfx942 -fopenmp-version=52 -O2 repro.c -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
craycc -fopenmp -fopenmp-targets=amdgcn-amd-amdhsa -Xopenmp-target=amdgcn-amd-amdhsa -march=gfx942 -fopenmp-version=52 -O2 repro.c -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
craycc -fopenmp -fopenmp-targets=amdgcn-amd-amdhsa -Xopenmp-target=amdgcn-amd-amdhsa -march=gfx942 -fopenmp-version=52 -O2 repro.c -o repro
HSA_XNACK=1 OMP_TARGET_OFFLOAD=mandatory ./repro

NVHPC 25.11, A100 separate (runs correctly)

export LD_LIBRARY_PATH=$NVHPC_25_11/compilers/lib
nvc -mp=gpu -gpu=cc80 -gpu=mem:separate -O2 repro.c -o repro
OMP_TARGET_OFFLOAD=mandatory ./repro

Program (46 lines)

/* Finding (C): at -fopenmp-version=52 both clang C front ends
   reject the deprecated but normative `to` clause of declare target.

   Legal OpenMP 5.2 C. "The clause-name to may be used as a synonym for the
   clause-name enter. This use has been deprecated." (5.2 §5.8.4 p.158; also
   Appendix B.1 p.625), and "deprecated"
   is "the property that it is normative in the current specification but
   is considered obsolescent and will be removed in the future" (5.2
   §1.2.7 p.20); 6.0 removes it (the catalog's 6.0 programs use enter).
   Expected: "RESULT ran_on_host=0 check=pass".

   Observed (tuolumne, MI300A, HSA_XNACK=1, -O2, 2026-10-22,
   data/evidence/triage_probe/dt_to.c, results/t27b/probes.jsonl): AFAR amdclang
   24.0.0git and CCE craycc 19.0.0, 20.0.2, 21.0.3 at -fopenmp-version=52:
   "error: unexpected 'to' clause, use 'enter' instead"; without the flag
   (their default, OpenMP 5.1) all four compile and run it correctly. The
   catalog's omp52-c-clause-device_type, -device_type-any, -device_type-
   nohost programs were rejected on every compiler because of it; since
   Those C ports use enter(f), so they measure
   device_type.

   Legality rests on the quoted spec text only: there is no independent
   compiler witness (cited gcc 13.3.1 -fopenmp; gfortran/gcc -fopenmp
   are withdrawn as offload legality witnesses, data/reports/rulings.md).

   amdclang -fopenmp --offload-arch=gfx942 -fopenmp-version=52 -O2
   craycc -fopenmp -fopenmp-targets=amdgcn-amd-amdhsa
          -Xopenmp-target=amdgcn-amd-amdhsa -march=gfx942
          -fopenmp-version=52 -O2 */
#include <stdio.h>
#include <omp.h>
enum { n = 64 };
int f(int x) { return 2 * x + 1; }
#pragma omp declare target to(f) device_type(any)
int main(void) {
  int a[n], b[n], bad = 0, host_flag = 1;
  for (int i = 0; i < n; i++) { a[i] = i + 1; b[i] = 0; }
  #pragma omp target map(to: a) map(from: b) map(tofrom: host_flag)
  {
    host_flag = omp_is_initial_device() ? 1 : 0;
    for (int i = 0; i < n; i++) b[i] = f(a[i]);
  }
  for (int i = 0; i < n; i++) bad += b[i] != 2 * (i + 1) + 1;
  printf("RESULT ran_on_host=%d check=%s\n", host_flag, bad ? "fail" : "pass");
  return 0;
}

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

Expected

RESULT ran_on_host=0 check=pass

Observed where it behaves incorrectly

clang-c-declare-target-to-omp52.c:5:28: error: unexpected 'to' clause, use 'enter' instead
    5 | #pragma omp declare target to(f) device_type(any)
      |                            ^
clang-c-declare-target-to-omp52.c:5:21: error: expected at least one 'enter', 'link' or 'indirect' clause
    5 | #pragma omp declare target to(f) device_type(any)
      |                     ^
2 errors generated.

What the specification requires

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

OpenMP 5.2 §5.8.4 p.158

The clause-name to may be used as a synonym for the clause-name enter. This use has been deprecated.

OpenMP 5.2 §1.2.7 p.20

the property that it is normative in the current specification but is considered obsolescent and will be removed in the future

Evidence

Same compiler, one change

enter(f) instead of to(f): 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

#include <stdio.h>
#include <omp.h>
enum { n = 64 };
int f(int x) { return 2 * x + 1; }
#pragma omp declare target enter(f) device_type(any)
int main(void) {
  int a[n], b[n], bad = 0, host_flag = 1;
  for (int i = 0; i < n; i++) { a[i] = i + 1; b[i] = 0; }
  #pragma omp target map(to: a) map(from: b) map(tofrom: host_flag)
  {
    host_flag = omp_is_initial_device() ? 1 : 0;
    for (int i = 0; i < n; i++) b[i] = f(a[i]);
  }
  for (int i = 0; i < n; i++) bad += b[i] != 2 * (i + 1) + 1;
  printf("RESULT ran_on_host=%d check=%s\n", host_flag, bad ? "fail" : "pass");
  return 0;
}

Other compilers run it correctly

NVHPC 25.11, NVHPC 26.9, GCC 16.2.0