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Bug#: 33294
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Status: RESOLVED
Resolution: INVALID
Assigned To: Not yet assigned to anyone <unassigned@gcc.gnu.org>
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Reporter: Serge Belyshev <belyshev@depni.sinp.msu.ru>
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Description:   Last confirmed: Opened: 2007-09-03 17:46 
Compile with "-O2 -fno-strict-aliasing", fails on amd64 and alpha at least. 
Doesn't fail with -fno-tree-vrp.  Seems to be related to bug 32575.  Breaks
linux kernel in many places (this asm is used with prefetch instruction).


struct T { void *p; } *t;

int main (void)
{
  struct T *a;

  a = t;
  asm volatile ("" : : "m" (*(unsigned long *) a));
  if (a)
    __builtin_abort ();
  return 0;
}

------- Comment #1 From Serge Belyshev 2007-09-03 18:13 ------- 
This bug is invalid because asm() does NULL pointer dereference, thus
triggering undefined behavior.
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