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

   1 /* { dg-do link } */
   2 /* { dg-options "-fno-allow-store-data-races" } */
   3 /* { dg-final { simulate-thread } } */
   4
   5 #include <stdio.h>
   6 #include "simulate-thread.h"
   7
   8 /* This file tests that speculative store movement out of a loop doesn't
   9    happen.  This is disallowed when -fno-allow-store-data-races.  */
  10
  11 int global = 100;
  12
  13 /* Other thread makes sure global is 100 before the next instruction is
  14  * exceuted.  */
  15 void simulate_thread_other_threads()
  16 {
  17   global = 100;
  18 }
  19
  20 int simulate_thread_step_verify()
  21 {
  22   if (global != 100)
  23     {
  24       printf("FAIL: global variable was assigned to.  \n");
  25       return 1;
  26     }
  27   return 0;
  28 }
  29
  30 int simulate_thread_final_verify()
  31 {
  32   return 0;
  33 }
  34
  35 /* The variable global should never be assigned if func(0) is called.
  36    This tests store movement out of loop thats never executed. */
  37 void test (int y)
  38 {
  39   int x;
  40   for (x=0; x< y; x++)
  41     {
  42        global = y;   /* This should never speculatively execute.  */
  43     }
  44 }
  45
  46 __attribute__((noinline))
  47 void simulate_thread_main()
  48 {
  49   test(0);
  50   simulate_thread_done();
  51 }
  52
  53 __attribute__((noinline))
  54 int main()
  55 {
  56   simulate_thread_main();
  57   return 0;
  58 }