------- Comment #9 from jakub at gcc dot gnu dot org 2010-05-10 10:13 -------
Created an attachment (id=20617)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=20617&action=view)
gcc46-pr44023.patch
The bug is that if a debug insn references more than one dead pseudo, only the
first one is recorded using dead_debug_add. That means the other pseudos
stay alive beyond REG_DEAD notes and affect e.g. RA decisions.
Attached patch fixes this by calling dead_debug_add on all the uses instead of
just one. This alone crashes badly, because dead_debug_insert_before which
replaces one of the uses in a debug insn calls df_insn_rescan on it, which
invalidates all the other uses. So we need to queue rescanning it until
dead_debug_finish (or, at least until all dead debug records referencing the
debug_insn are gone).
I'll bootstrap/regtest the patch on x86_64-linux and i686-linux, Uros, can you
please do the same on alpha*-*?
--
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|NEW |ASSIGNED
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44023
