/* Verify that NRV optimizations are prohibited when the LHS is an indirect reference to something that may be call-clobbered. */ /* { dg-do compile } */ /* { dg-options "-O -fdump-tree-optimized" } */ typedef struct { int x[20]; void *y; } S; S nrv_candidate (void); void use_result (S); void make_escape (S *); S global_S; void foo (void) { S *result; S local_S; /* We can't perform return slot optimization because global_S is global and may be clobbered by nrv_candidate. */ result = &global_S; *result = nrv_candidate (); use_result (*result); /* We can't perform return slot optimization because local_S is call_clobbered (its address escapes prior to invoking nrv_candidate). */ make_escape (&local_S); result = &local_S; *result = nrv_candidate (); use_result (*result); } /* { dg-final { scan-tree-dump-times "return slot optimization" 0 "optimized" } } */ /* { dg-final { cleanup-tree-dump "optimized" } } */