https://gcc.gnu.org/g:693be70f589682c0c65ce92c4602d481aa7f16e3
commit 693be70f589682c0c65ce92c4602d481aa7f16e3 Author: Julian Brown <[email protected]> Date: Wed Apr 23 03:11:29 2025 +0000 OpenACC: Allow implicit uses of assumed-size arrays in offload regions This patch reimplements the functionality of the previously-reverted patch "Assumed-size arrays with non-lexical data mappings". The purpose is to support implicit uses of assumed-size arrays for Fortran when those arrays have already been mapped on the target some other way (e.g. by "acc enter data"). This relates to upstream OpenACC issue 489 (not yet resolved). gcc/fortran/ * trans-openmp.cc (gfc_omp_finish_clause): Treat implicitly-mapped assumed-size arrays as zero-sized for OpenACC, rather than an error. gcc/testsuite/ * gfortran.dg/goacc/assumed-size.f90: Don't expect error. libgomp/ * testsuite/libgomp.oacc-fortran/nonlexical-assumed-size-1.f90: New test. * testsuite/libgomp.oacc-fortran/nonlexical-assumed-size-2.f90: New test. Diff: --- gcc/fortran/trans-openmp.cc | 16 ++++++--- gcc/testsuite/gfortran.dg/goacc/assumed-size.f90 | 4 +-- .../nonlexical-assumed-size-1.f90 | 29 +++++++++++++++ .../nonlexical-assumed-size-2.f90 | 41 ++++++++++++++++++++++ 4 files changed, 84 insertions(+), 6 deletions(-) diff --git a/gcc/fortran/trans-openmp.cc b/gcc/fortran/trans-openmp.cc index c28d937295a6..cfecdb0a6c60 100644 --- a/gcc/fortran/trans-openmp.cc +++ b/gcc/fortran/trans-openmp.cc @@ -1595,6 +1595,7 @@ gfc_omp_finish_clause (tree c, gimple_seq *pre_p, bool openacc) tree decl = OMP_CLAUSE_DECL (c); location_t loc = OMP_CLAUSE_LOCATION (c); + bool assumed_size = false; /* Assumed-size arrays can't be mapped implicitly, they have to be mapped explicitly using array sections. */ @@ -1605,9 +1606,14 @@ gfc_omp_finish_clause (tree c, gimple_seq *pre_p, bool openacc) GFC_TYPE_ARRAY_RANK (TREE_TYPE (decl)) - 1) == NULL) { - error_at (OMP_CLAUSE_LOCATION (c), - "implicit mapping of assumed size array %qD", decl); - return; + if (openacc) + assumed_size = true; + else + { + error_at (OMP_CLAUSE_LOCATION (c), + "implicit mapping of assumed size array %qD", decl); + return; + } } if (OMP_CLAUSE_MAP_KIND (c) == GOMP_MAP_FORCE_DEVICEPTR) @@ -1662,7 +1668,9 @@ gfc_omp_finish_clause (tree c, gimple_seq *pre_p, bool openacc) else { OMP_CLAUSE_DECL (c) = decl; - OMP_CLAUSE_SIZE (c) = NULL_TREE; + OMP_CLAUSE_SIZE (c) = assumed_size ? size_zero_node : NULL_TREE; + if (assumed_size) + OMP_CLAUSE_MAP_MAYBE_ZERO_LENGTH_ARRAY_SECTION (c) = 1; } if (TREE_CODE (TREE_TYPE (orig_decl)) == REFERENCE_TYPE && (GFC_DECL_GET_SCALAR_POINTER (orig_decl) diff --git a/gcc/testsuite/gfortran.dg/goacc/assumed-size.f90 b/gcc/testsuite/gfortran.dg/goacc/assumed-size.f90 index 4fced2e70c9e..12f44c4743a2 100644 --- a/gcc/testsuite/gfortran.dg/goacc/assumed-size.f90 +++ b/gcc/testsuite/gfortran.dg/goacc/assumed-size.f90 @@ -4,7 +4,8 @@ ! exit data, respectively. ! This does not appear to be supported by the OpenACC standard as of version -! 3.0. Check for an appropriate error message. +! 3.0. There is however real-world code that relies on this working, so we +! make an attempt to support it. program test implicit none @@ -26,7 +27,6 @@ subroutine dtest (a, n) !$acc enter data copyin(a(1:n)) !$acc parallel loop -! { dg-error {implicit mapping of assumed size array 'a'} "" { target *-*-* } .-1 } do i = 1, n a(i) = i end do diff --git a/libgomp/testsuite/libgomp.oacc-fortran/nonlexical-assumed-size-1.f90 b/libgomp/testsuite/libgomp.oacc-fortran/nonlexical-assumed-size-1.f90 new file mode 100644 index 000000000000..8b173c72d887 --- /dev/null +++ b/libgomp/testsuite/libgomp.oacc-fortran/nonlexical-assumed-size-1.f90 @@ -0,0 +1,29 @@ +! { dg-do run } + +program p +implicit none +integer :: myarr(10) + +myarr = 0 + +call subr(myarr) + +if (myarr(5).ne.5) stop 1 + +contains + +subroutine subr(arr) +implicit none +integer :: arr(*) + +!$acc enter data copyin(arr(1:10)) + +!$acc serial +! { dg-warning {using .vector_length \(32\)., ignoring 1} "" { target openacc_nvidia_accel_selected } .-1 } +arr(5) = 5 +!$acc end serial + +!$acc exit data copyout(arr(1:10)) + +end subroutine subr +end program p diff --git a/libgomp/testsuite/libgomp.oacc-fortran/nonlexical-assumed-size-2.f90 b/libgomp/testsuite/libgomp.oacc-fortran/nonlexical-assumed-size-2.f90 new file mode 100644 index 000000000000..659fe8e3c066 --- /dev/null +++ b/libgomp/testsuite/libgomp.oacc-fortran/nonlexical-assumed-size-2.f90 @@ -0,0 +1,41 @@ +! { dg-do run } + +program p +implicit none +integer :: myarr(10) + +myarr = 0 + +call subr(myarr) + +if (myarr(5).ne.5) stop 1 + +contains + +subroutine subr(arr) +implicit none +integer :: arr(*) + +! At first glance, it might not be obvious how this works. The "enter data" +! and "exit data" operations expand to a pair of mapping nodes for OpenACC, +! GOMP_MAP_{TO/FROM} and GOMP_MAP_POINTER. The former maps the array data, +! and the latter creates a separate mapping on the target for the pointer +! itself with a bias so it represents the "zeroth" element. + +!$acc enter data copyin(arr(2:8)) + +! ...then this implicit mapping creates a zero-length array section +! (GOMP_MAP_ZERO_LEN_ARRAY_SECTION) followed by another GOMP_MAP_POINTER for +! 'arr'. But now that pointer is already "present" on the target, so is not +! overwritten. + +!$acc serial +! { dg-warning {using .vector_length \(32\)., ignoring 1} "" { target openacc_nvidia_accel_selected } .-1 } +! This access is then done via the on-target pointer. +arr(5) = 5 +!$acc end serial + +!$acc exit data copyout(arr(2:8)) + +end subroutine subr +end program p
