https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81752
Bug ID: 81752 Summary: num_gangs(65536) converted to 0 Product: gcc Version: 8.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: libgomp Assignee: unassigned at gcc dot gnu.org Reporter: vries at gcc dot gnu.org CC: jakub at gcc dot gnu.org Target Milestone: --- num_gangs hits a limit at 65536 for nvptx. For this example: ... int main () { #pragma acc parallel num_gangs(65536) ; return 0; } ... we get this warning: ... /tmp/ccjtQtKi.c:47:21: warning: unsigned conversion from 'int' to 'short unsigned int' changes value from '65536' to '0' [-Woverflow] {"main$_omp_fn$0", 0x10000, 0x1, 0x20} ... The code triggering the warning in more detail: ... static const struct nvptx_fn { const char *name; unsigned short dim[3]; } func_mappings[] = { {"main$_omp_fn$0", 0x10000, 0x1, 0x20} }; ...