------- Comment #3 from jakub at gcc dot gnu dot org 2009-10-02 16:35 ------- Created an attachment (id=18693) --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=18693&action=view) gcc45-pr41511.patch
Agreed. Patch I'm going to bootstrap/regtested on x86_64-linux and i686-linux now, fixes this -fcompare-debug issue on the testcase in x86_64-linux -> sh4-linux cross. The zero extension is indeed unneeded in this case, perhaps reg_num_sign_bit_copies_for_combine could try harder. The thing is that if get_last_value before the final validation finds it is MEM and only the validation changes it into a clobber because it is unknown what value will the memory have, if LOAD_EXTEND_OP is SIGN_EXTEND for the mode, it doesn't really matter what value the memory has for num_sign_bit_copies. -- jakub at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- AssignedTo|unassigned at gcc dot gnu |jakub at gcc dot gnu dot org |dot org | Status|UNCONFIRMED |ASSIGNED http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41511