http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50762
--- Comment #4 from Ulrich Weigand <uweigand at gcc dot gnu.org> 2011-11-08
16:00:36 UTC ---
It seems to me (part of) the problem is that the operand constraint is too
generic here:
(define_insn "*lea_4_zext"
[(set (match_operand:DI 0 "register_operand" "=r")
(zero_extend:DI
(match_operand:SI 1 "lea_address_operand" "p")))]
"p" accepts any legitimate address operand, including const_int. But those are
then not actually accepted by the overall pattern (due to the mode check).
When reloading within an address operand, reload verifies only the constraint;
it does not expect the case where a constraint accepts something that is later
rejected by some other check.
One fix might be to use a more specific constraint here that does not accept
const_int.
