[Bug rtl-optimization/58679] [4.9 regression] ICE in create_pre_exit, at mode-switching.c:421 with -mavx after r202915

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58679

Eric Botcazou <ebotcazou at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ebotcazou at gcc dot gnu.org

--- Comment #8 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
> Or should we use a different approach, and use DF to re-create REG_DEAD
> notes?

Yes, if you need REG_DEAD/REG_UNUSED notes, just tell DF to compute them:

eric@polaris:~/gnat/gnat-head/src/gcc> grep df_note_add_problem *.c
auto-inc-dec.c:  df_note_add_problem ();
cfgrtl.c:      df_note_add_problem ();
combine.c:  df_note_add_problem ();
combine-stack-adj.c:  df_note_add_problem ();
cse.c:  df_note_add_problem ();
df-problems.c:df_note_add_problem (void)
dse.c:  df_note_add_problem ();
fwprop.c:  df_note_add_problem ();
haifa-sched.c:  df_note_add_problem ();
ira.c:  df_note_add_problem ();
loop-iv.c:  df_note_add_problem ();
recog.c:  df_note_add_problem ();
regmove.c:  df_note_add_problem ();
regrename.c:  df_note_add_problem ();
reg-stack.c:  df_note_add_problem ();