Re: [PATCH] tree-vect-patterns: Fix up ICE in upper_bound [PR109115]

[Richard Biener <rguenther@suse.de>]

On Tue, 14 Mar 2023, Jakub Jelinek wrote:

> Hi!
> 
> As mentioned in the PR, range_of_expr returns false if the type
> of the expression isn't suitable for corresponding range type,
> but doesn't if the range is undefined for other reasons.  Still,
> lower/upper_bound is defined only for ranges which actually have
> at least one pair of subranges, VR_UNDEFINED range doesn't have it.
> 
> Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux,
> ok for trunk?

OK.

> 2023-03-14  Jakub Jelinek  <jakub@redhat.com>
> 
> 	PR tree-optimization/109115
> 	* tree-vect-patterns.cc (vect_recog_divmod_pattern): Don't use
> 	r.upper_bound () on r.undefined_p () range.
> 
> 	* gcc.dg/pr109115.c: New test.
> 
> --- gcc/tree-vect-patterns.cc.jj	2023-03-12 22:36:06.388177607 +0100
> +++ gcc/tree-vect-patterns.cc	2023-03-13 22:49:18.278476093 +0100
> @@ -3973,7 +3973,7 @@ vect_recog_divmod_pattern (vec_info *vin
>  	  /* Check that no overflow will occur.  If we don't have range
>  	     information we can't perform the optimization.  */
>  
> -	  if (ranger.range_of_expr (r, oprnd0, stmt))
> +	  if (ranger.range_of_expr (r, oprnd0, stmt) && !r.undefined_p ())
>  	    {
>  	      wide_int max = r.upper_bound ();
>  	      wide_int one = wi::shwi (1, prec);
> --- gcc/testsuite/gcc.dg/pr109115.c.jj	2023-03-13 22:56:27.269428198 +0100
> +++ gcc/testsuite/gcc.dg/pr109115.c	2023-03-13 22:56:04.174753778 +0100
> @@ -0,0 +1,20 @@
> +/* PR tree-optimization/109115 */
> +/* { dg-do compile } */
> +/* { dg-options "-O2" } */
> +
> +int a, b;
> +
> +int
> +main ()
> +{
> +  unsigned short c = a, e = -1;
> +  if (b)
> +    {
> +      unsigned d = (a ^ 1U) / a & c;
> +      int f = (~d >> ~a) / e;
> +      if (a)
> +	f = a;
> +      a = f;
> +    }
> +  return 0;
> +}
> 
> 	Jakub
> 
> 

-- 
Richard Biener <rguenther@suse.de>
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