gcc/testsuite/gcc.c-torture/execute/stkalign.c

   1 /* { dg-options "-fno-inline" } */
   2 /* Check that stack alignment is not affected by variables not placed
   3    on the stack.  */
   4
   5 #include <assert.h>
   6
   7 #define ALIGNMENT 64
   8
   9 unsigned test(unsigned n, unsigned p)
  10 {
  11   static struct { char __attribute__((__aligned__(ALIGNMENT))) c; } s;
  12   unsigned x;
  13
  14   assert(__alignof__(s) == ALIGNMENT);
  15   asm ("" : "=g" (x), "+m" (s) : "0" (&x));
  16
  17   return n ? test(n - 1, x) : (x ^ p);
  18 }
  19
  20 unsigned test2(unsigned n, unsigned p)
  21 {
  22   static struct { char c; } s;
  23   unsigned x;
  24
  25   assert(__alignof__(s) != ALIGNMENT);
  26   asm ("" : "=g" (x), "+m" (s) : "0" (&x));
  27
  28   return n ? test2(n - 1, x) : (x ^ p);
  29 }
  30
  31 int main (int argc, char *argv[] __attribute__((unused)))
  32 {
  33   unsigned int x, y;
  34
  35   x = test(argc, 0);
  36   x |= test(argc + 1, 0);
  37   x |= test(argc + 2, 0);
  38
  39   y = test2(argc, 0);
  40   y |= test2(argc + 1, 0);
  41   y |= test2(argc + 2, 0);
  42
  43   return (x & (ALIGNMENT - 1)) == 0 && (y & (ALIGNMENT - 1)) != 0 ? 1 : 0;
  44 }