gcc/testsuite/gcc.dg/simulate-thread/speculative-store-2.c

   1 /* { dg-do link } */
   2 /* { dg-options "--param allow-store-data-races=0 -O2" } */
   3 /* { dg-final { simulate-thread } } */
   4
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7
   8 #include "simulate-thread.h"
   9
  10 /* Test that speculative stores do not happen for --param
  11    allow-store-data-races=0.  */
  12
  13 int count, insns;
  14
  15 struct obj {
  16     int data;
  17     struct obj *next;
  18 } *q;
  19
  20 void simulate_thread_other_threads ()
  21 {
  22   ++insns;
  23   ++count;
  24 }
  25
  26 int simulate_thread_step_verify ()
  27 {
  28   return 0;
  29 }
  30
  31 int simulate_thread_final_verify ()
  32 {
  33   /* If count != insns, someone must have cached `count' and stored a
  34      racy value into it.  */
  35   if (count != insns)
  36     {
  37       printf("FAIL: count was incorrectly cached\n");
  38       return 1;
  39     }
  40   return 0;
  41 }
  42
  43 /* Test that `count' is not written to unless p->data > 0.  */
  44
  45 __attribute__((noinline))
  46 void simulate_thread_main()
  47 {
  48   struct obj *p;
  49   for (p = q; p; p = p->next)
  50     if (p->data > 0)
  51       count++;
  52 }
  53
  54 struct obj *
  55 insert(struct obj *head, int data)
  56 {
  57   struct obj *t = (struct obj *) malloc (sizeof (struct obj));
  58   t->next = head;
  59   t->data = data;
  60   return t;
  61 }
  62
  63 int main()
  64 {
  65   q = insert (0, 0);
  66   q = insert (q, 0);
  67   q = insert (q, 0);
  68   q = insert (q, 0);
  69   q = insert (q, 0);
  70
  71   simulate_thread_main ();
  72   simulate_thread_done ();
  73   return 0;
  74 }