https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63246
Bug ID: 63246
Summary: OpenMP target: gimplifier produces unsuitable implicit
map clauses if inside a data region
Product: gcc
Version: 5.0
Status: UNCONFIRMED
Keywords: openmp
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: tschwinge at gcc dot gnu.org
CC: jakub at gcc dot gnu.org
Consider:
int
main(int argc, char **argv)
{
#define N 4
short a[N];
#pragma omp target data map(a[1:N-1])
{
#pragma omp target
{
a[1] = 51;
}
}
return 0;
}
..., which results in the following gimple:
[...]
#pragma omp target data map(tofrom:a[1] [len: 6]) map(alloc:a
[pointer assign, bias: 2])
{
try
{
{
#pragma omp target map(tofrom:a [len: 8])
{
{
a[1] = 51;
[...]
The outer data region sets up an expicit mapping for a subset of the array, and
the inner target construct then again gets an implicit map clause added for
*the whole* region. A suitably equipped libgomp (for example, gomp-4_0-branch
with the non-shared memory host plugin) doesn't like this:
libgomp: Trying to map into device [0x7fff6f513410..0x7fff6f513418) object
when[0x7fff6f513412..0x7fff6f513418) is already mapped
