gcc/testsuite/gcc.dg/tree-ssa/loadpre6.c

   1 /* { dg-do compile } */
   2 /* { dg-options "-O2 -fdump-tree-pre-stats" } */
   3 #include <stddef.h>
   4
   5 union tree_node;
   6 typedef union tree_node *tree;
   7
   8 struct tree_common
   9 {
  10   tree chain;
  11 };
  12
  13 struct tree_list
  14 {
  15   struct tree_common common;
  16   tree value;
  17 };
  18
  19 union tree_node
  20
  21 {
  22   struct tree_common common;
  23   struct tree_list list;
  24 };
  25
  26 extern void abort (void) __attribute__((noreturn));
  27
  28 void __attribute__((noinline))
  29 foo (void)
  30 {
  31   abort ();
  32 }
  33
  34 /* There are some reloaded loads of *cell, and cell->common.chain on various
  35    branches.  */
  36 void __attribute__((noinline))
  37 remove_useless_vars (tree *unexpanded_var_list, int dump_file)
  38 {
  39   tree var, *cell;
  40   int c = 0;
  41   for (cell = unexpanded_var_list; *cell; )
  42     {
  43       var = (*cell)->list.value;
  44       if (var)
  45         {
  46           if (dump_file)
  47             foo ();
  48
  49           *cell = ((*cell)->common.chain);
  50           continue;
  51         }
  52
  53       cell = &((*cell)->common.chain);
  54     }
  55 }
  56 extern void *malloc (__SIZE_TYPE__) __attribute__ ((malloc));
  57
  58 int
  59 main (void)
  60 {
  61   int i;
  62   tree unexpanded_var_list, last = (tree) 0;
  63
  64   for (i = 0; i < 2; i++)
  65     {
  66       unexpanded_var_list = malloc (sizeof (struct tree_list));
  67       unexpanded_var_list->list.value = (tree) (ptrdiff_t) (i & 1);
  68       unexpanded_var_list->common.chain = last;
  69       last = unexpanded_var_list;
  70     }
  71
  72   remove_useless_vars (&unexpanded_var_list, 0);
  73   return 0;
  74 }
  75 /* { dg-final { scan-tree-dump-times "Eliminated: 2" 1 "pre" } } */
  76 /* { dg-final { cleanup-tree-dump "pre" } } */
  77