------- Comment #3 from steven at gcc dot gnu dot org 2007-05-08 23:15 -------
This patch would fix it, but it's brute-force and it causes a ~1.5% slowdown.
Some form of DCE a little more delicate than this will be necessary to fix this
bug, though.
Index: cfgcleanup.c
===================================================================
--- cfgcleanup.c (revision 124550)
+++ cfgcleanup.c (working copy)
@@ -2286,10 +2286,10 @@ cleanup_cfg (int mode)
{
delete_unreachable_blocks (), changed = true;
if (!(mode & CLEANUP_NO_INSN_DEL)
- && (mode & CLEANUP_EXPENSIVE)
- && !reload_completed)
+ && (mode & (CLEANUP_EXPENSIVE | CLEANUP_CROSSJUMP)))
{
- if (!delete_trivially_dead_insns (get_insns (), max_reg_num ()))
+ gcc_assert (df);
+ if (! run_fast_dce ())
break;
}
else
@@ -2343,10 +2343,9 @@ static unsigned int
rest_of_handle_jump2 (void)
{
delete_trivially_dead_insns (get_insns (), max_reg_num ());
+ delete_unreachable_blocks ();
if (dump_file)
dump_flow_info (dump_file, dump_flags);
- cleanup_cfg ((optimize ? CLEANUP_EXPENSIVE : 0)
- | (flag_thread_jumps ? CLEANUP_THREADING : 0));
return 0;
}
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30905
