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/* PR rtl-optimization/9771 */
/* { dg-do run } */
/* { dg-require-effective-target ia32 } */
/* { dg-options "-O2 -fomit-frame-pointer -ffixed-ebp" } */
extern void abort(void);
extern void exit(int);
register long *B asm ("ebp");
long x = 10;
long y = 20;
void bar(void)
{
B = &y;
}
void foo()
{
long *adr = B;
long save = *adr;
*adr = 123;
bar();
*adr = save;
}
/* This must not be inlined because main() requires the frame pointer
for stack alignment. */
void test(void) __attribute__((noinline));
void test(void)
{
B = &x;
foo();
if (x != 10 || y != 20)
abort();
/* We can't return, as our caller may assume %ebp is preserved! */
/* We could save/restore it (like foo), but its easier to exit. */
exit(0);
}
/* main usually performs dynamic realignment of the stack in case
_start would fail to properly align the stack, but for dynamic
stack realignment we need frame pointer which is incompatible
with -ffixed-ebp and the global register var. So, cheat here
and hide from the compiler that main is really main. */
#define ASMNAME(cname) ASMNAME2 (__USER_LABEL_PREFIX__, cname)
#define ASMNAME2(prefix, cname) STRING (prefix) cname
#define STRING(x) #x
int real_main() __asm (ASMNAME ("main"));
int real_main()
{
test();
return 0;
}
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