Re: VOIDmode in ZERO_EXTEND crashed

[Joern Rennecke]

Quoting daniel tian <daniel.xnt...@gmail.com>:

hi, everyone:
     I have ported the gcc to new RISC chip. But when I build the
newlib with it, the gcc crashed in simplify-rtx.c.
     error message is like this:

     ../../../../../newlib-1.16.0/newlib/libc/time/tzset_r.c: In
function _tzset_r?
     ../../../../../newlib-1.16.0/newlib/libc/time/tzset_r.c:195:
internal compiler error: in simplify_const_unary_operation, at
simplify-rtx.c:1108

     And the code there is simplify-rtx.c 1108:

     case ZERO_EXTEND:
          /* When zero-extending a CONST_INT, we need to know its
             original mode.  */
          gcc_assert (op_mode != VOIDmode);

     I tracked the gcc, It caused by the RTX   (const_int 60). As I
know the CONST_INT is alway being VOIDmode.

That exactly is the problem.  You can't have a CONST_INT inside a
ZERO_EXTEND.  That is not valid.
You'll need a separate pattern to recognize the CONST_INT without a
ZERO_EXTEND around it.  Unfortunately, this will not give reload
the freedom it should have.