Re: [PATCH 3/12] phiopt: Fix phiopt ICE on vops [PR102989]

[Richard Biener <rguenther@suse.de>]

On Wed, 9 Aug 2023, Jakub Jelinek wrote:

> On Wed, Aug 09, 2023 at 01:06:22PM -0700, Andrew Pinski wrote:
> > That was my next thought, returning NULL from
> > single_non_singleton_phi_for_edges if it would return a virtual OP
> > might be better even.
> > Either version of these patches are ok with me (though I am not the
> > maintainer here).
> 
> In patch form that would be (but so far untested):

LGTM

> 2023-08-09  <jakub@redhat.com>
> 
> 	PR c/102989
> 	* tree-ssa-phiopt.cc (single_non_singleton_phi_for_edges): Never
> 	return virtual phis and return NULL if there is a virtual phi
> 	where the arguments from E0 and E1 edges aren't equal.
> 
> --- gcc/tree-ssa-phiopt.cc.jj	2023-08-09 22:08:07.974563266 +0200
> +++ gcc/tree-ssa-phiopt.cc	2023-08-09 22:11:37.291517911 +0200
> @@ -63,7 +63,13 @@ single_non_singleton_phi_for_edges (gimp
>    gimple_stmt_iterator i;
>    gphi *phi = NULL;
>    if (gimple_seq_singleton_p (seq))
> -    return as_a <gphi *> (gsi_stmt (gsi_start (seq)));
> +    {
> +      phi = as_a <gphi *> (gsi_stmt (gsi_start (seq)));
> +      /* Never return virtual phis.  */
> +      if (virtual_operand_p (gimple_phi_result (phi)))
> +	return NULL;
> +      return phi;
> +    }
>    for (i = gsi_start (seq); !gsi_end_p (i); gsi_next (&i))
>      {
>        gphi *p = as_a <gphi *> (gsi_stmt (i));
> @@ -72,6 +78,10 @@ single_non_singleton_phi_for_edges (gimp
>  				       gimple_phi_arg_def (p, e1->dest_idx)))
>  	continue;
>  
> +      /* Punt on virtual phis with different arguments from the edges.  */
> +      if (virtual_operand_p (gimple_phi_result (p)))
> +	return NULL;
> +
>        /* If we already have a PHI that has the two edge arguments are
>  	 different, then return it is not a singleton for these PHIs. */
>        if (phi)
> 
> 
> 	Jakub
> 
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE Software Solutions Germany GmbH,
Frankenstrasse 146, 90461 Nuernberg, Germany;
GF: Ivo Totev, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)