gcc/testsuite/gcc.c-torture/execute/alloca-1.c

   1 /* { dg-skip-if "requires alloca" { ! alloca } { "-O0" } { "" } } */
   2 /* Verify that alloca storage is sufficiently aligned.  */
   3 /* ??? May fail if BIGGEST_ALIGNMENT > STACK_BOUNDARY.  Which, I guess
   4    can only happen on !STRICT_ALIGNMENT targets.  */
   5
   6 typedef __SIZE_TYPE__ size_t;
   7
   8 struct dummy { int x __attribute__((aligned)); };
   9 #define BIGGEST_ALIGNMENT __alignof__(struct dummy)
  10
  11 _Bool foo(void)
  12 {
  13   char *p = __builtin_alloca(32);
  14   return ((size_t)p & (BIGGEST_ALIGNMENT - 1)) == 0;
  15 }
  16
  17 int main()
  18 {
  19   if (!foo())
  20     abort ();
  21   return 0;
  22 }