http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46649
--- Comment #7 from Alexander Monakov <amonakov at gcc dot gnu.org> 2010-12-14 14:38:38 UTC --- After a discussion with Andrey and refreshing my memory on that code I think it's actually better to unbreak purge_empty_blocks in this case. It used to be correct, i.e. it never attempted to delete the first BB in the region; then I broke it because I wasn't aware of the limitation w.r.t. removal of the first BB. Sorry for the spam. diff --git a/gcc/sel-sched-ir.c b/gcc/sel-sched-ir.c index 427fd22..9f0c4a3 100644 --- a/gcc/sel-sched-ir.c +++ b/gcc/sel-sched-ir.c @@ -3749,10 +3749,10 @@ tidy_control_flow (basic_block xbb, bool full_tidying) void purge_empty_blocks (void) { - /* Do not attempt to delete preheader. */ - int i = sel_is_loop_preheader_p (BASIC_BLOCK (BB_TO_BLOCK (0))) ? 1 : 0; + int i; - while (i < current_nr_blocks) + /* Do not attempt to delete the first basic block in the region. */ + for (i = 1; i < current_nr_blocks; i++) { basic_block b = BASIC_BLOCK (BB_TO_BLOCK (i));