[Bug target/17551] m68hc11: ICE: unrecognizable insn

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

------- Additional Comments From ciceron at gcc dot gnu dot org  2005-02-13 11:16 -------
The compiler crashes because the GCSE pass generates an invalid insn:

(insn 138 10 108 0 (nil) (set (reg:SI 61)
        (reg/v:SI 55)) -1 (nil)
    (nil))

and this is caused by handle_avail_exp()  which uses gen_rtx_SET () to
make the copy.  This is correct for QI and HI modes but fails with SI/DI modes
because the HC11 port needs a more complex move (with a PARALLEL and a scratch).
Jeff Law comment in gcse.c (arround lines 3472):

      /* ??? If the change fails, we return 0, even though we created
	 an insn.  I think this is ok.  */

is wrong.  The change indeed failed but the insn remains and it's not valid
so it crashes later on.

Using gen_move_insn() fixed the problem.


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |ciceron at gcc dot gnu dot
                   |dot org                     |org
             Status|UNCONFIRMED                 |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17551