gcc/testsuite/gcc.dg/nrv3.c

   1 /* Verify that gimple-level NRV is occurring when values other than the
   2    return slot are call-clobbered.  */
   3 /* { dg-do compile } */
   4 /* { dg-options "-O -fdump-tree-optimized" } */
   5
   6 #ifdef __SPU__
   7 /* SPU returns aggregates up to 1172 bytes in registers.  */
   8 typedef struct { int x[300]; void *y; } S;
   9 #else
  10 typedef struct { int x[20]; void *y; } S;
  11 #endif
  12 typedef struct { int a; S b; } T;
  13 S nrv_candidate (void);
  14 void use_result (S, int);
  15 int *ptr;
  16 void foo (void)
  17 {
  18   S result;
  19   T result_arr[10][5];
  20
  21   int i;
  22
  23   ptr = &i;
  24
  25   /* i is call-clobbered for these calls, but result and result_arr
  26      aren't.  */
  27   result = nrv_candidate ();
  28   result_arr[3][4].b = nrv_candidate ();
  29
  30   use_result (result, i);
  31   use_result (result_arr[3][4].b, i);
  32 }
  33
  34 /* { dg-final { scan-tree-dump-times "return slot optimization" 2 "optimized" } } */
  35 /* { dg-final { cleanup-tree-dump "optimized" } } */