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Re: [PATCH] Remove vdefs when changing a normal call into noreturn call (PR tree-optimization/44539)
- From: Richard Guenther <rguenther at suse dot de>
- To: Jakub Jelinek <jakub at redhat dot com>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Fri, 25 Jun 2010 13:48:23 +0200 (CEST)
- Subject: Re: [PATCH] Remove vdefs when changing a normal call into noreturn call (PR tree-optimization/44539)
- References: <20100625114355.GI12443@tyan-ft48-01.lab.bos.redhat.com>
On Fri, 25 Jun 2010, Jakub Jelinek wrote:
> Hi!
>
> When a call has VDEF, but doesn't have lhs and is through noreturn discovery
> changed into a noreturn call, we failed to remove the VDEF, which caused
> verification errors.
>
> Fixed thusly, bootstrapped/regtested on x86_64-linux and i686-linux.
> Ok for trunk?
Ok.
Thanks,
Richard.
> Calling update_stmt unconditionally there isn't possible, as update_stmt
> adds the stmt into MODIFIED_NORETURN_CALLS and thus
> split_bbs_on_noreturn_calls hangs. If it has lhs or vdef, the first
> update_stmt call changes it and the next one won't call update_stmt anymore.
>
> 2010-06-25 Jakub Jelinek <jakub@redhat.com>
>
> PR tree-optimization/44539
> * tree-cfgcleanup.c (fixup_noreturn_call): Call update_stmt even when
> the call doesn't have LHS, but has VDEF.
>
> * gcc.dg/pr44539.c: New test.
>
> --- gcc/tree-cfgcleanup.c.jj 2010-06-14 07:44:24.000000000 +0200
> +++ gcc/tree-cfgcleanup.c 2010-06-24 11:44:59.000000000 +0200
> @@ -591,6 +591,9 @@ fixup_noreturn_call (gimple stmt)
> update_stmt (stmt);
> changed = true;
> }
> + /* Similarly remove VDEF if there is any. */
> + else if (gimple_vdef (stmt))
> + update_stmt (stmt);
> return changed;
> }
>
> --- gcc/testsuite/gcc.dg/pr44539.c.jj 2010-06-24 11:45:16.000000000 +0200
> +++ gcc/testsuite/gcc.dg/pr44539.c 2010-06-24 11:44:26.000000000 +0200
> @@ -0,0 +1,29 @@
> +/* PR tree-optimization/44539 */
> +/* { dg-do compile } */
> +/* { dg-options "-ftracer -freorder-blocks -O2" } */
> +
> +void bar (int file);
> +extern int baz (void);
> +
> +void noret1 ()
> +{
> + bar (0);
> + __builtin_exit (0);
> +}
> +
> +void noret2 ()
> +{
> + __builtin_exit (0);
> +}
> +
> +void bar (int i)
> +{
> + if (baz ())
> + noret1 (i);
> +}
> +
> +void foo (int i)
> +{
> + if (~i) bar (i);
> + i ? noret1 () : noret2 ();
> +}
>
> Jakub
>
>
--
Richard Guenther <rguenther@suse.de>
Novell / SUSE Labs
SUSE LINUX Products GmbH - Nuernberg - AG Nuernberg - HRB 16746 - GF: Markus Rex