[patch,testsuite] Support dg-require-effective-target label_offsets.

[Georg-Johann Lay]

On 04.11.2016 06:18, Senthil Kumar Selvaraj wrote:
>
> Georg-Johann Lay writes:
>> State of matters is that Binutils support is missing, and if I understand you
>> correctly, dg-require is not appropriate to factor out availability of such
>> features?
>
> I'll take a stab at adding the missing binutils support for avr label diffs.

Thanks for taking care of this.  I had a look into it but got stuck with a test 
case derived from gcc.c-torture/execute/pr70460.c

int c;

__attribute__((noinline, noclone)) void
call (void)
{
   __asm ("nop");
}

__attribute__((noinline, noclone)) void
foo (int x)
{
   static int b[] = { &&lab1 - &&lab0, &&lab2 - &&lab0 };
   void *a = &&lab0 + b[x];
   goto *a;
lab1:
   c += 2;
   call();
lab2:
   c++;
lab0:
   ;
}

int
main ()
{
   foo (0);
   if (c != 3)
     __builtin_abort ();
   foo (1);
   if (c != 4)
     __builtin_abort ();
   return 0;
}


The problem is when relaxation is turned on and the CALL is shortened to  RCALL 
but respective literals are not fixed up.

Johann

> Regards
> Senthil