[Bug tree-optimization/20640] [4.0 Regression] ICE on NULL PHI_ARG_DEF

["jakub at redhat dot com" <gcc-bugzilla at gcc dot gnu dot org>]

------- Additional Comments From jakub at redhat dot com  2005-03-30 07:56 -------
Subject: Re: [PR tree-optimization/20640] add phi args to dests of dce-redirected edges

On Wed, Mar 30, 2005 at 02:56:24AM -0300, Alexandre Oliva wrote:
> When remove_dead_stmt() redirects a control stmt, the edge redirection
> reserves space for the phi arg for the new incoming edge in all phi
> nodes, but, instead of filling them in with information obtained from
> the edge redirection, we simply discard this information.  This leaves
> NULL in the phi args, which may cause crashes later on.
> 
> This patch fixes the problem by filling in the phi args using the
> PENDING_STMT list created during edge redirection.  This appears to be
> the intended use for this information, and it is used similarly in
> e.g. loop unrolling.
> 
> Bootstrapping mainline and 4.0 branch on amd64-linux-gnu, and mainline
> on i686-pc-linux-gnu.  Ok to install if bootstrap and regtesting pass?
> 
> The patch below is for the 4.0 branch, but it applies cleanly and
> correctly in mainline as well, since it's just a few lines off.

Note this is PR tree-optimization/20640, not PR 20460
(typo in ChangeLog as well as subject line, while the testcase is ok).

	Jakub


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20640