1 /* Verify that NRV optimizations are prohibited when the LHS is an 2 indirect reference to something that may be call-clobbered. */ 3 /* { dg-do compile } */ 4 /* { dg-options "-O -fdump-tree-optimized" } */ 5 6 typedef struct { int x[20]; void *y; } S; 7 S nrv_candidate (void); 8 void use_result (S); 9 void make_escape (S *); 10 S global_S; foo(void)11void foo (void) 12 { 13 S *result; 14 S local_S; 15 16 /* We can't perform return slot optimization because global_S is 17 global and may be clobbered by nrv_candidate. */ 18 result = &global_S; 19 *result = nrv_candidate (); 20 use_result (*result); 21 22 /* We can't perform return slot optimization because local_S is 23 call_clobbered (its address escapes prior to invoking 24 nrv_candidate). */ 25 make_escape (&local_S); 26 result = &local_S; 27 *result = nrv_candidate (); 28 use_result (*result); 29 } 30 31 /* { dg-final { scan-tree-dump-times "return slot optimization" 0 "optimized" } } */ 32 33