This patch fixes a bug in non-contiguous 'target update' operations using the new array-shaping operator for C and C++, processing the dimensions of the array the wrong way round during the OpenMP lowering pass. Fortran was also incorrectly using the wrong ordering but the second reversal in omp-low.cc made it produce the correct result.
The C and C++ bug only affected array shapes where the dimension sizes are different ([X][Y]) - several existing tests used the same value for both/all dimensions ([X][X]), which masked the problem. Only the array dimensions (extents) are affected, not e.g. the indices, lengths or strides for array sections. This patch reverses the order used in both omp-low.cc and the Fortran front-end, so the order should now be correct for all supported base languages. Tested with offloading to AMD GCN. I will apply (to og13) shortly. 2023-07-14 Julian Brown <jul...@codesourcery.com> gcc/fortran/ * trans-openmp.cc (gfc_trans_omp_arrayshape_type): Reverse dimension ordering for created array type. gcc/ * omp-low.cc (lower_omp_target): Reverse iteration over array dimensions. libgomp/ * testsuite/libgomp.c-c++-common/array-shaping-14.c: New test. --- gcc/fortran/trans-openmp.cc | 2 +- gcc/omp-low.cc | 6 ++-- .../libgomp.c-c++-common/array-shaping-14.c | 34 +++++++++++++++++++ 3 files changed, 38 insertions(+), 4 deletions(-) create mode 100644 libgomp/testsuite/libgomp.c-c++-common/array-shaping-14.c diff --git a/gcc/fortran/trans-openmp.cc b/gcc/fortran/trans-openmp.cc index 6cb5340687e..6b9a0430eba 100644 --- a/gcc/fortran/trans-openmp.cc +++ b/gcc/fortran/trans-openmp.cc @@ -4271,7 +4271,7 @@ gfc_trans_omp_arrayshape_type (tree type, vec<tree> *dims) { gcc_assert (dims->length () > 0); - for (int i = dims->length () - 1; i >= 0; i--) + for (unsigned i = 0; i < dims->length (); i++) { tree dim = fold_convert (sizetype, (*dims)[i]); /* We need the index of the last element, not the array size. */ diff --git a/gcc/omp-low.cc b/gcc/omp-low.cc index c7706a5921f..ab2e4145ab2 100644 --- a/gcc/omp-low.cc +++ b/gcc/omp-low.cc @@ -14290,7 +14290,7 @@ lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx) dims++; } - int tdim = tdims.length () - 1; + unsigned tdim = 0; vec<constructor_elt, va_gc> *vdim; vec<constructor_elt, va_gc> *vindex; @@ -14365,7 +14365,7 @@ lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx) nc = nc2; } - if (tdim >= 0) + if (tdim < tdims.length ()) { /* We have an array shape -- use that to find the total size of the data on the target to look up @@ -14403,7 +14403,7 @@ lower_omp_target (gimple_stmt_iterator *gsi_p, omp_context *ctx) "for array"); dim = index = len = stride = error_mark_node; } - tdim--; + tdim++; c = nc; } diff --git a/libgomp/testsuite/libgomp.c-c++-common/array-shaping-14.c b/libgomp/testsuite/libgomp.c-c++-common/array-shaping-14.c new file mode 100644 index 00000000000..4ca6f794f93 --- /dev/null +++ b/libgomp/testsuite/libgomp.c-c++-common/array-shaping-14.c @@ -0,0 +1,34 @@ +/* { dg-do run { target offload_device_nonshared_as } } */ + +#include <stdlib.h> +#include <stdio.h> +#include <assert.h> + +typedef struct { + int *ptr; +} S; + +int main(void) +{ + S q; + q.ptr = (int *) calloc (9 * 11, sizeof (int)); + +#pragma omp target enter data map(to: q.ptr, q.ptr[0:9*11]) + +#pragma omp target + for (int i = 0; i < 9*11; i++) + q.ptr[i] = i; + +#pragma omp target update from(([9][11]) q.ptr[3:3:2][1:4:3]) + + for (int j = 0; j < 9; j++) + for (int i = 0; i < 11; i++) + if (j >= 3 && j <= 7 && ((j - 3) % 2) == 0 + && i >= 1 && i <= 10 && ((i - 1) % 3) == 0) + assert (q.ptr[j * 11 + i] == j * 11 + i); + else + assert (q.ptr[j * 11 + i] == 0); + +#pragma omp target exit data map(release: q.ptr, q.ptr[0:9*11]) + return 0; +} -- 2.25.1