Re: [PATCH] sel-sched: run cleanup_cfg just before loop_optimizer_init (PR 84659)

[Andrey Belevantsev <abel at ispras dot ru>]

On 12.04.2018 0:55, Alexander Monakov wrote:
> As noted in PR 85354, we cannot simply invoke cfg_cleanup after dominators are
> computed, because they may become invalid but neither freed nor recomputed, so
> this trips checking in flow_loops_find.
> 
> We can move cleanup_cfg earlier (and run it for all sel-sched invocations, not
> only when pipelining).

OK.  Sorry, I should have noticed that before, and our ia64 tester also
misses libraries required for graphite.

Best,
Andrey

> 
> Bootstrapped/regtested on x86_64 and ppc64 (my previous testing missed this
> issue: the testcase requires graphite, but libisl wasn't present).
> 
> 	PR rtl-optimization/85354
> 	* sel-sched-ir.c (sel_init_pipelining): Move cfg_cleanup call...
> 	* sel-sched.c (sel_global_init): ... here.
> 
> diff --git a/gcc/sel-sched-ir.c b/gcc/sel-sched-ir.c
> index 50a7daafba6..ee970522890 100644
> --- a/gcc/sel-sched-ir.c
> +++ b/gcc/sel-sched-ir.c
> @@ -30,7 +30,6 @@ along with GCC; see the file COPYING3.  If not see
>  #include "cfgrtl.h"
>  #include "cfganal.h"
>  #include "cfgbuild.h"
> -#include "cfgcleanup.h"
>  #include "insn-config.h"
>  #include "insn-attr.h"
>  #include "recog.h"
> @@ -6122,9 +6121,6 @@ make_regions_from_loop_nest (struct loop *loop)
>  void
>  sel_init_pipelining (void)
>  {
> -  /* Remove empty blocks: their presence can break assumptions elsewhere,
> -     e.g. the logic to invoke update_liveness_on_insn in sel_region_init.  */
> -  cleanup_cfg (0);
>    /* Collect loop information to be used in outer loops pipelining.  */
>    loop_optimizer_init (LOOPS_HAVE_PREHEADERS
>                         | LOOPS_HAVE_FALLTHRU_PREHEADERS
> diff --git a/gcc/sel-sched.c b/gcc/sel-sched.c
> index cd29df35666..59762964c6e 100644
> --- a/gcc/sel-sched.c
> +++ b/gcc/sel-sched.c
> @@ -28,6 +28,7 @@ along with GCC; see the file COPYING3.  If not see
>  #include "tm_p.h"
>  #include "regs.h"
>  #include "cfgbuild.h"
> +#include "cfgcleanup.h"
>  #include "insn-config.h"
>  #include "insn-attr.h"
>  #include "params.h"
> @@ -7661,6 +7662,10 @@ sel_sched_region (int rgn)
>  static void
>  sel_global_init (void)
>  {
> +  /* Remove empty blocks: their presence can break assumptions elsewhere,
> +     e.g. the logic to invoke update_liveness_on_insn in sel_region_init.  */
> +  cleanup_cfg (0);
> +
>    calculate_dominance_info (CDI_DOMINATORS);
>    alloc_sched_pools ();
>