Re: [patch, ice, selective scheduler] Patch for PR 41697

[Vladimir Makarov <vmakarov at redhat dot com>]

Andrey Belevantsev wrote:
> Hello,
>
> Andrey Belevantsev wrote:
> > Andrey Belevantsev wrote:
> > > Hi Steve,
> > >
> > > Steve Ellcey wrote:
> > > > This patch fixes an ICE on IA64 with the testcase
> > > > gcc.c-torture/compile/20090917-1.c.  That test will generate an ICE in
> > > > the selective scheduler because we try to access the successor to a
> > > > basic block before verifying that the basic block has any successors.
> > > > This patch adds a check and fixes the ICE.
>
> I have missed the second instance of this issue that can be seen when 
> using selective scheduler on the above test with -O2.  The problem is 
> that a block ending on a conditional jump has a single successor, thus 
> using FALLTHRU_EDGE on it like in fallthru_bb_of_jump crashes.  The 
> following simple patch avoids this.  Is it ok for trunk?
Ok. Thanks.
>   The patch is safe, and the bug technically is probably a regression, 
> though I don't have a 4.4.x build on ia64 to back up this.
>
> Bootstrapped and tested on ia64 with sel-sched enabled at -O2.
>
> Andrey
>
> 2009-11-12  Andrey Belevantsev  <abel@ispras.ru>
>
>     PR rtl-optimization/41697
>     * sel-sched-ir.c (fallthru_bb_of_jump): Bail out when a block with 
> a conditional jump has a single successor.