[Bug c/71876] longjmp is miscompiled with -ffreestanding

[bernd.edlinger at hotmail dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71876

--- Comment #2 from Bernd Edlinger <bernd.edlinger at hotmail dot de> ---
test case for the ECF_LEAF:

test.c:

int setjmp(void);
static int x;

void foo(int z)
{
 x = z;
}

int bar(void)
{
  int z = x;
  setjmp();
  z += x;
  return z;
}


gcc -O3 -S -ffreestanding test.c

bar:
.LFB1:
        .cfi_startproc
        subq    $24, %rsp
        .cfi_def_cfa_offset 32
        movl    x(%rip), %eax
        movl    %eax, 12(%rsp)
        call    setjmp
        movl    12(%rsp), %eax
        addq    $24, %rsp
        .cfi_def_cfa_offset 8
        addl    %eax, %eax
        ret
        .cfi_endproc


but the free-standing setjmp function could call back to foo.