https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99932
--- Comment #2 from Tom de Vries <vries at gcc dot gnu.org> --- Minimal example: ... $ cat libgomp/testsuite/libgomp.oacc-c-c++-common/parallel-dims.c int main (void) { int vectors_max = -1; #pragma acc parallel \ num_gangs (1) \ num_workers (1) \ vector_length (32) \ copy (vectors_max) { #pragma acc loop gang reduction (max: vectors_max) for (int i = 0; i < 2; i++) #pragma acc loop worker reduction (max: vectors_max) for (int j = 0; j < 2; j++) #pragma acc loop vector reduction (max: vectors_max) for (int k = 0; k < 32; k++) vectors_max = k; } if (vectors_max != 31) __builtin_abort (); return 0; } ... Passes with GOMP_NVPTX_JIT=-O0, starts failing at GOMP_NVPTX_JIT=-O1.