Re: [PATCH] Fix ICE during strstr gimple folding (PR middle-end/81207)

[Richard Biener <rguenther@suse.de>]

On Tue, 27 Jun 2017, Jakub Jelinek wrote:

> Hi!
> 
> replace_call_with_call_and_fold has code to copy over vdef/vuse from the
> old call to the new one, so that we don't have to update virtual ssa,
> but it is conditioned on gimple_vdef being non-NULL and SSA_NAME.
> If we have a pure function, gimple_vdef is NULL, yet we still want to copy
> over the vuse.
> 
> Bootstrapped/regtested on x86_64-linux (i686-linux fails to bootstrap
> with/without this patch), ok for trunk?

Ok with ...

> 2017-06-27  Jakub Jelinek  <jakub@redhat.com>
> 
> 	PR middle-end/81207
> 	* gimple-fold.c (replace_call_with_call_and_fold): Handle
> 	gimple_vuse copying separately from gimple_vdef copying.
> 
> 	* gcc.c-torture/compile/pr81207.c: New test.
> 
> --- gcc/gimple-fold.c.jj	2017-06-19 08:28:11.000000000 +0200
> +++ gcc/gimple-fold.c	2017-06-26 17:09:34.735420583 +0200
> @@ -607,9 +607,11 @@ replace_call_with_call_and_fold (gimple_
>        && TREE_CODE (gimple_vdef (stmt)) == SSA_NAME)
>      {
>        gimple_set_vdef (repl, gimple_vdef (stmt));
> -      gimple_set_vuse (repl, gimple_vuse (stmt));
>        SSA_NAME_DEF_STMT (gimple_vdef (repl)) = repl;
>      }
> +  if (gimple_vuse (stmt)
> +      && TREE_CODE (gimple_vuse (stmt)) == SSA_NAME)

... the SSA_NAME check removed.  It's done above because we access
SSA_NAME_DEF_STMT, here it isn't necessary.

> +    gimple_set_vuse (repl, gimple_vuse (stmt));
>    gsi_replace (gsi, repl, false);
>    fold_stmt (gsi);
>  }
> --- gcc/testsuite/gcc.c-torture/compile/pr81207.c.jj	2017-06-26 17:21:38.765918367 +0200
> +++ gcc/testsuite/gcc.c-torture/compile/pr81207.c	2017-06-26 17:27:15.222966965 +0200
> @@ -0,0 +1,13 @@
> +/* PR middle-end/81207 */
> +
> +static const char *b[2] = { "'", "" };
> +
> +int
> +foo (const char *d)
> +{
> +  int e;
> +  for (e = 0; b[e]; e++)
> +    if (__builtin_strstr (d, b[e]))
> +      return 1;
> +  return 0;
> +}
> 
> 	Jakub
> 
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nuernberg)