https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80463
--- Comment #12 from Andrey Belevantsev <abel at gcc dot gnu.org> ---
(In reply to Arseny Solokha from comment #11)
> How about this one? It makes only trunk gcc ICE, though.
>
> short int t2;
> int cd, aa, ft;
>
> void
> dh (void)
> {
> int qs = 0;
>
> if (t2 < 1)
> {
> int bq = 0;
>
> while (bq < 1)
> {
> }
>
> while (t2 < 1)
> {
> if (t2 == 0)
> {
> bq = 0;
> cd = !!cd;
> }
> else
> {
> bq = 1;
> cd = bq > qs;
> }
>
> t2 += cd;
> bq = (t2 / qs) == bq;
>
> if (aa != ft)
> {
> qs %= 0;
> while (bq != 0)
> {
> ro:
> ;
> }
> }
>
> ++t2;
> }
>
> ia:
> goto ro;
> }
>
> goto ia;
> }
>
> % gcc-8.0.0-alpha20180114 -O2 -fvar-tracking-assignments
> -fselective-scheduling2 -ftree-loop-vectorize -fnon-call-exceptions
> -fno-tree-vrp -fno-gcse-lm -fno-tree-loop-im
> -fno-reorder-blocks-and-partition -fno-reorder-blocks
> -fno-move-loop-invariants -w -c rsd2aiem.c
> during RTL pass: sched2
> rsd2aiem.c: In function 'dh':
> rsd2aiem.c:51:1: internal compiler error: in
> av_set_could_be_blocked_by_bookkeeping_p, at sel-sched.c:3622
> }
> ^
> 0x64ad85 av_set_could_be_blocked_by_bookkeeping_p
>
> /var/tmp/portage/sys-devel/gcc-8.0.0_alpha20180114/work/gcc-8-20180114/gcc/
> sel-sched.c:3622
> 0x64ad85 code_motion_process_successors
>
> /var/tmp/portage/sys-devel/gcc-8.0.0_alpha20180114/work/gcc-8-20180114/gcc/
> sel-sched.c:6395
> 0x64ad85 code_motion_path_driver
>
> /var/tmp/portage/sys-devel/gcc-8.0.0_alpha20180114/work/gcc-8-20180114/gcc/
> sel-sched.c:6617
> 0xc59886 code_motion_process_successors
>
> /var/tmp/portage/sys-devel/gcc-8.0.0_alpha20180114/work/gcc-8-20180114/gcc/
> sel-sched.c:6351
> 0xc59886 code_motion_path_driver
>
> /var/tmp/portage/sys-devel/gcc-8.0.0_alpha20180114/work/gcc-8-20180114/gcc/
> sel-sched.c:6617
> 0xc59886 code_motion_process_successors
>
> /var/tmp/portage/sys-devel/gcc-8.0.0_alpha20180114/work/gcc-8-20180114/gcc/
> sel-sched.c:6351
> 0xc59886 code_motion_path_driver
>
> /var/tmp/portage/sys-devel/gcc-8.0.0_alpha20180114/work/gcc-8-20180114/gcc/
> sel-sched.c:6617
> 0xc5aa5a find_used_regs
>
> /var/tmp/portage/sys-devel/gcc-8.0.0_alpha20180114/work/gcc-8-20180114/gcc/
> sel-sched.c:3283
> 0xc5aa5a collect_unavailable_regs_from_bnds
>
> /var/tmp/portage/sys-devel/gcc-8.0.0_alpha20180114/work/gcc-8-20180114/gcc/
> sel-sched.c:1598
> 0xc5aa5a find_best_reg_for_expr
>
> /var/tmp/portage/sys-devel/gcc-8.0.0_alpha20180114/work/gcc-8-20180114/gcc/
> sel-sched.c:1661
> 0xc5aa5a fill_vec_av_set
>
> /var/tmp/portage/sys-devel/gcc-8.0.0_alpha20180114/work/gcc-8-20180114/gcc/
> sel-sched.c:3797
> 0xc5da87 fill_ready_list
>
> /var/tmp/portage/sys-devel/gcc-8.0.0_alpha20180114/work/gcc-8-20180114/gcc/
> sel-sched.c:4027
> 0xc5da87 find_best_expr
>
> /var/tmp/portage/sys-devel/gcc-8.0.0_alpha20180114/work/gcc-8-20180114/gcc/
> sel-sched.c:4387
> 0xc5da87 fill_insns
>
> /var/tmp/portage/sys-devel/gcc-8.0.0_alpha20180114/work/gcc-8-20180114/gcc/
> sel-sched.c:5544
> 0xc5da87 schedule_on_fences
>
> /var/tmp/portage/sys-devel/gcc-8.0.0_alpha20180114/work/gcc-8-20180114/gcc/
> sel-sched.c:7361
> 0xc5da87 sel_sched_region_2
>
> /var/tmp/portage/sys-devel/gcc-8.0.0_alpha20180114/work/gcc-8-20180114/gcc/
> sel-sched.c:7499
> 0xc61737 sel_sched_region_1
>
> /var/tmp/portage/sys-devel/gcc-8.0.0_alpha20180114/work/gcc-8-20180114/gcc/
> sel-sched.c:7541
> 0xc61737 sel_sched_region(int)
>
> /var/tmp/portage/sys-devel/gcc-8.0.0_alpha20180114/work/gcc-8-20180114/gcc/
> sel-sched.c:7642
> 0xc627a8 run_selective_scheduling()
>
> /var/tmp/portage/sys-devel/gcc-8.0.0_alpha20180114/work/gcc-8-20180114/gcc/
> sel-sched.c:7718
> 0xc42625 rest_of_handle_sched2
>
> /var/tmp/portage/sys-devel/gcc-8.0.0_alpha20180114/work/gcc-8-20180114/gcc/
> sched-rgn.c:3729
>
> (as of r256677)
Give me a few more days for unrelated stuff and I'll have enough time to look
at this. If that turns to be the same dependence issue, we can check in a
patch without waiting for hot/cold bbs issue to be sorted out.
