1  /* { dg-do link } */
       2  /* { dg-options "-fno-allow-store-data-races -O2" } */
       3  /* { dg-final { simulate-thread } } */
       4  
       5  #include <stdio.h>
       6  #include <stdlib.h>
       7  
       8  #include "simulate-thread.h"
       9  
      10  /* Test distilled from PR52558.  */
      11  
      12  int g_1 = 1;
      13  int g_2 = 0, insns = 0;
      14  int f;
      15  
      16  /* Test that g_2 is not written to unless !g_1.  */
      17  
      18  __attribute__((noinline))
      19  int funky()
      20  {
      21    int l;
      22    for (l = 0; l != 4; l++)
      23      {
      24        if (g_1)
      25  	{
      26  	  /* g_1 is globally true so we should always execute here,
      27  	     thus never writing to g_2 under any circumstance in this
      28  	     code path.  */
      29  	  return l;
      30  	}
      31        for (g_2 = 0; g_2 >= 26; ++g_2)
      32  	;
      33      }
      34    return 999;
      35  }
      36  
      37  int simulate_thread_final_verify ()
      38  {
      39    /* If g_2 != insns, someone must have cached `g_2' and stored a
      40       racy value into it.  */
      41    if (g_2 != insns)
      42      {
      43        printf("FAIL: g_2 was incorrectly cached\n");
      44        return 1;
      45      }
      46    return 0;
      47  }
      48  
      49  void simulate_thread_other_threads ()
      50  {
      51    ++insns;
      52    ++g_2;
      53  }
      54  
      55  int simulate_thread_step_verify ()
      56  {
      57    return 0;
      58  }
      59  
      60  __attribute__((noinline))
      61  void simulate_thread_main()
      62  {
      63    f = funky();
      64  }
      65  
      66  int main()
      67  {
      68    simulate_thread_main ();
      69    simulate_thread_done ();
      70    return 0;
      71  }