[Bug rtl-optimization/51933] [4.7 regression] wrong code due to -free

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51933

--- Comment #8 from Jakub Jelinek <jakub at gcc dot gnu.org> 2012-01-23 09:25:55 UTC ---
Author: jakub
Date: Mon Jan 23 09:25:52 2012
New Revision: 183416

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=183416
Log:
    PR rtl-optimization/51933
    * ree.c (transform_ifelse): Return true right away if dstreg is
    already wider or equal to cand->mode.
    (enum ext_modified_kind, struct ext_modified, ext_state): New types.
    (make_defs_and_copies_lists): Remove defs_list and copies_list
    arguments, add state argument, just truncate state->work_list
    instead of always allocating and freeing the vector.  Assert that
    get_defs succeeds instead of returning 2.  Changed return type to
    bool.
    (merge_def_and_ext): Add state argument.  If SET_DEST doesn't
    have ext_src_mode, see if it has been modified already with the
    right kind of extension and has been extended before from the
    ext_src_mode.  If SET_DEST is already wider or equal to cand->mode,
    just return true.  Remember the original mode in state->modified
    array.
    (combine_reaching_defs): Add state argument.  Don't allocate and
    free here def_list, copied_list and vec vectors, instead just
    VEC_truncate the vectors in *state.  Don't handle outcome == 2
    here.
    (find_and_remove_re): Set DF_DEFER_INSN_RESCAN df flag.
    Add state variable, clear vectors in it, initialize state.modified
    if needed.  Free all the vectors at the end and state.modified too.
    Don't skip a candidate if the extension expression has been modified.

    * gcc.c-torture/execute/pr51933.c: New test.

Added:
    trunk/gcc/testsuite/gcc.c-torture/execute/pr51933.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/ree.c
    trunk/gcc/testsuite/ChangeLog