Check that there are no missing probabilities

[Jakub Jelinek]

On Fri, Oct 13, 2017 at 03:38:33PM +0200, Jan Hubicka wrote:
> Hi,
> this patch enables check that no edge probabilities are missing. 
> 
> Honza
> 
> 	* cfghooks.c (verify_flow_info): Check that edge probabilities are
> 	set.

This broke bootstrap on x86_64-linux with Ada
(--enable-checking=yes,rtl,extra).

>From what I can see, decompose_multiword_subregs has:
1619			  /* Split the block after insn.  There will be a fallthru
1620			     edge, which is OK so we keep it.  We have to create the
1621			     exception edges ourselves.  */
1622			  fallthru = split_block (bb, insn);
1623			  rtl_make_eh_edge (NULL, bb, BB_END (bb));
1624			  bb = fallthru->dest;
1625			  insn = BB_HEAD (bb);
and rtl_make_eh_edge calls
161	      make_label_edge (edge_cache, src, label,
162			       EDGE_ABNORMAL | EDGE_EH
163			       | (CALL_P (insn) ? EDGE_ABNORMAL_CALL : 0));

No idea what should initialize the probabilities.  Do probabilities make
any sense at all for EH edges (or abnormal edges)?

> 
> Index: cfghooks.c
> ===================================================================
> --- cfghooks.c	(revision 253694)
> +++ cfghooks.c	(working copy)
> @@ -160,6 +161,13 @@ verify_flow_info (void)
>  		     e->src->index, e->dest->index);
>  	      err = 1;
>  	    }
> +	  if (profile_status_for_fn (cfun) >= PROFILE_GUESSED
> +	      && !e->probability.initialized_p ())
> +	    {
> +	      error ("Uninitialized probability of edge %i->%i", e->src->index,
> +		     e->dest->index);
> +	      err = 1;
> +	    }
>  	  if (!e->probability.verify ())
>  	    {
>  	      error ("verify_flow_info: Wrong probability of edge %i->%i",

	Jakub