------- Comment #17 from bonzini at gnu dot org 2008-05-02 16:29 -------
I wonder if your patch would be a problem because it sometimes removes a CONST
wrapping. It could also be possible to precede the CONST_INT optimization with
another test for two adjacent CONSTANT_P:
if (GET_CODE (ops[n_ops - 1]) == CONST_INT)
i = n_ops - 2;
else
i = n_ops - 1;
if (i >= 1
&& ops[i].neg
&& !ops[i - 1].neg
&& CONSTANT_P (ops[i].op)
&& GET_CODE (ops[i].op) == GET_CODE (ops[i - 1].op))
{
ops[i - 1].op = gen_rtx_MINUS (mode, ops[i - 1].op, ops[i].op);
ops[i - 1].op = gen_rtx_CONST (mode, ops[i - 1].op);
if (i < n_ops - 1)
ops[i] = op[i + 1];
n_ops--;
}
Keeping together a (minus (symbol_ref) (symbol_ref)), which could also be a
(minus (label_ref (label_ref)), seems like a good idea.
Does this work?
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36090
