https://gcc.gnu.org/g:1258bf1bcf8e6b211017b55c5ae5819cdedd794c
commit 1258bf1bcf8e6b211017b55c5ae5819cdedd794c Author: Paul-Antoine Arras <[email protected]> Date: Tue Oct 21 09:48:23 2025 +0200 OpenMP: Fix bogus diagnostics with intervening code [PR121452] The introduction in r14-3488-ga62c8324e7e31a of OMP_STRUCTURED_BLOCK (to diagnose invalid intervening code) caused a regression rejecting the valid use of the Fortran CONTINUE statement to end a collapsed loop. This patch fixes the incorrect error checking in the OMP lowering pass. It also fixes a check in the Fortran front end that erroneously rejects a similar statement in an ordered loop. Co-authored by: Tobias Burnus <[email protected]> PR fortran/121452 gcc/fortran/ChangeLog: * openmp.cc (resolve_omp_do): Allow CONTINUE as end statement of a perfectly nested loop. gcc/ChangeLog: * omp-low.cc (check_omp_nesting_restrictions): Accept an OMP_STRUCTURED_BLOCK in a collapsed simd region and in an ordered loop. gcc/testsuite/ChangeLog: * c-c++-common/gomp/pr121452-1.c: New test. * c-c++-common/gomp/pr121452-2.c: New test. * gfortran.dg/gomp/pr121452-1.f90: New test. * gfortran.dg/gomp/pr121452-2.f90: New test. * gfortran.dg/gomp/pr121452-3.f90: New test. (cherry picked from commit 6b90d56d0c352a151efabe06f81d26faeeb9496f) Diff: --- gcc/fortran/openmp.cc | 3 ++- gcc/omp-low.cc | 6 ++++-- gcc/testsuite/c-c++-common/gomp/pr121452-1.c | 17 +++++++++++++++++ gcc/testsuite/c-c++-common/gomp/pr121452-2.c | 17 +++++++++++++++++ gcc/testsuite/gfortran.dg/gomp/pr121452-1.f90 | 18 ++++++++++++++++++ gcc/testsuite/gfortran.dg/gomp/pr121452-2.f90 | 22 ++++++++++++++++++++++ gcc/testsuite/gfortran.dg/gomp/pr121452-3.f90 | 22 ++++++++++++++++++++++ 7 files changed, 102 insertions(+), 3 deletions(-) diff --git a/gcc/fortran/openmp.cc b/gcc/fortran/openmp.cc index 0c6b2e0806d9..7a915adbb9da 100644 --- a/gcc/fortran/openmp.cc +++ b/gcc/fortran/openmp.cc @@ -12701,7 +12701,8 @@ resolve_omp_do (gfc_code *code) name, i, &code->loc); goto fail; } - else if (next != do_code->block->next || next->next) + else if (next != do_code->block->next + || (next->next && next->next->op != EXEC_CONTINUE)) /* Imperfectly nested loop found. */ { /* Only diagnose violation of imperfect nesting constraints once. */ diff --git a/gcc/omp-low.cc b/gcc/omp-low.cc index b6a57fbcc2b3..8679a796b249 100644 --- a/gcc/omp-low.cc +++ b/gcc/omp-low.cc @@ -3765,7 +3765,8 @@ check_omp_nesting_restrictions (gimple *stmt, omp_context *ctx) } else if (gimple_code (stmt) == GIMPLE_OMP_ATOMIC_LOAD || gimple_code (stmt) == GIMPLE_OMP_ATOMIC_STORE - || gimple_code (stmt) == GIMPLE_OMP_SCAN) + || gimple_code (stmt) == GIMPLE_OMP_SCAN + || gimple_code (stmt) == GIMPLE_OMP_STRUCTURED_BLOCK) return true; else if (gimple_code (stmt) == GIMPLE_OMP_FOR && gimple_omp_for_kind (ctx->stmt) == GF_OMP_FOR_KIND_SIMD) @@ -3795,7 +3796,8 @@ check_omp_nesting_restrictions (gimple *stmt, omp_context *ctx) && gimple_code (stmt) != GIMPLE_OMP_PARALLEL && (gimple_code (stmt) != GIMPLE_OMP_FOR || gimple_omp_for_kind (stmt) != GF_OMP_FOR_KIND_SIMD) - && gimple_code (stmt) != GIMPLE_OMP_SCAN) + && gimple_code (stmt) != GIMPLE_OMP_SCAN + && gimple_code (stmt) != GIMPLE_OMP_STRUCTURED_BLOCK) { if (ctx->loop_p) error_at (gimple_location (stmt), diff --git a/gcc/testsuite/c-c++-common/gomp/pr121452-1.c b/gcc/testsuite/c-c++-common/gomp/pr121452-1.c new file mode 100644 index 000000000000..d605919e565a --- /dev/null +++ b/gcc/testsuite/c-c++-common/gomp/pr121452-1.c @@ -0,0 +1,17 @@ +/* { dg-do compile } */ +/* { dg-additional-options "-fdump-tree-original" } */ + +/* Check that the OMP_STRUCTURED_BLOCK that wraps intervening code is accepted. + */ + +void f(int *A, int *B, int *C) +{ + #pragma omp for simd collapse(2) + for (int i=0; i < 1; i++) { + for (int j=0; j < 1; j++) + A[i] += B[j]; + C[i] = 4; + } +} + +/* { dg-final { scan-tree-dump "#pragma omp __structured_block" "original" } } */ diff --git a/gcc/testsuite/c-c++-common/gomp/pr121452-2.c b/gcc/testsuite/c-c++-common/gomp/pr121452-2.c new file mode 100644 index 000000000000..35fb1c1534b8 --- /dev/null +++ b/gcc/testsuite/c-c++-common/gomp/pr121452-2.c @@ -0,0 +1,17 @@ +/* { dg-do compile } */ +/* { dg-additional-options "-fdump-tree-original" } */ + +/* Check that the OMP_STRUCTURED_BLOCK that wraps intervening code is accepted. + */ + +void f(int *A, int *B, int *C) +{ + #pragma omp loop bind(teams) order(concurrent) collapse(2) + for (int i=0; i < 1; i++) { + for (int j=0; j < 1; j++) + A[i] += B[j]; + C[i] = 4; + } +} + +/* { dg-final { scan-tree-dump "#pragma omp __structured_block" "original" } } */ diff --git a/gcc/testsuite/gfortran.dg/gomp/pr121452-1.f90 b/gcc/testsuite/gfortran.dg/gomp/pr121452-1.f90 new file mode 100644 index 000000000000..60697c98ae39 --- /dev/null +++ b/gcc/testsuite/gfortran.dg/gomp/pr121452-1.f90 @@ -0,0 +1,18 @@ +! { dg-do compile } + +! Check that the front end acccepts a CONTINUE statement +! inside an ordered loop. + +implicit none +integer :: i, j +integer :: A(5,5), B(5,5) = 1 + +!$omp do ordered(2) + do 10 i = 1, 5 + do 20 j = 1, 5 + A(i,j) = B(i,j) +20 continue +10 continue + +if (any(A /= 1)) stop 1 +end diff --git a/gcc/testsuite/gfortran.dg/gomp/pr121452-2.f90 b/gcc/testsuite/gfortran.dg/gomp/pr121452-2.f90 new file mode 100644 index 000000000000..ab020d4bf912 --- /dev/null +++ b/gcc/testsuite/gfortran.dg/gomp/pr121452-2.f90 @@ -0,0 +1,22 @@ +! { dg-do compile } +! { dg-additional-options "-fdump-tree-original" } + +! Check that the OMP_STRUCTURED_BLOCK that wraps intervening code is accepted by +! the OMP lowering pass. + +implicit none +integer :: i, j, x +integer :: A(5,5), B(5,5) = 1 + +!$omp simd collapse(2) + do i = 1, 5 + do j = 1, 5 + A(i,j) = B(i,j) + end do + x = 1 ! intervening code + end do + +if (any(A /= 1)) stop 1 +end + +! { dg-final { scan-tree-dump "#pragma omp __structured_block" "original" } } diff --git a/gcc/testsuite/gfortran.dg/gomp/pr121452-3.f90 b/gcc/testsuite/gfortran.dg/gomp/pr121452-3.f90 new file mode 100644 index 000000000000..605f92c99cd9 --- /dev/null +++ b/gcc/testsuite/gfortran.dg/gomp/pr121452-3.f90 @@ -0,0 +1,22 @@ +! { dg-do compile } +! { dg-additional-options "-fdump-tree-original" } + +! Check that the OMP_STRUCTURED_BLOCK that wraps intervening code is accepted by +! the OMP lowering pass. + + +implicit none +integer :: i, j +integer :: A(5,5), B(5,5) = 1 + +!$omp simd collapse(2) + do 10 i = 1, 5 + do 20 j = 1, 5 + A(i,j) = B(i,j) +20 continue +10 continue + +if (any(A /= 1)) stop 1 +end + +! { dg-final { scan-tree-dump "#pragma omp __structured_block" "original" } }
