[Bug other/49942] Wrong code generated for -O2 with target s390 on Linux

["jakub at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49942

--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> 2011-08-02 13:36:53 UTC ---
I think the testcase from your exec charset for Linux would map to:
struct oper { char *digits; char sign; };
struct oper oper0 = {"\xf9\xf0\xf0\xf0\xf0\xf0\xf0\xf0\xf0", 'N'};
struct oper oper1 = {"\xf4\xf0\xf0\xf0\xf0\xf0\xf0\xf0\xf0", 'N'};

static int
comp (struct oper *op0, struct oper *op1)
{
  int i;
  __builtin_printf ("%s vs %s ", op0->digits, op1->digits);
  for (i = 0; 9 > i; i++)
    {
      int diff = (0xff & op0->digits[i]) - (0xff & op1->digits[i]);
      if (diff) return '`' == op0->sign ? (0 < diff ? -1 : 1) : (0 > diff ? -1
: 1);
    }
  return 0;
}

int
main ()
{
  __builtin_printf (" is %d\n", comp (&oper0, &oper1));
  __builtin_printf (" is %d\n", comp (&oper1, &oper0));
  return 0;
}

('0' through '9' are '\xf0' through '\xf9' apparently, and '+' is 'N' and '-'
is '`'.  If I run this on Linux, I still get the expected results.

No idea about if zVM doesn't set up something differently etc., clearly it
works on Linux.  Can you use a s390x-linux targetted compiler to compile code
for the VM at all, i.e. shouldn't that be a different target?