This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PATCH][RFC] Virtual operands in loop-closed SSA form
- From: Steven Bosscher <stevenb dot gcc at gmail dot com>
- To: Richard Guenther <rguenther at suse dot de>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Wed, 22 Aug 2012 19:47:43 +0200
- Subject: Re: [PATCH][RFC] Virtual operands in loop-closed SSA form
- References: <alpine.LNX.2.00.1208221458550.28649@zhemvz.fhfr.qr>
On Wed, Aug 22, 2012 at 3:01 PM, Richard Guenther <rguenther@suse.de> wrote:
>
> While we should already be in loop-closed SSA form for virtual
> operands most of the time (because we have a virtual use at
> the return statement) and loop-closed SSA form for virtuals
> is cheap (we only have a single virtual operand now) the following
> makes sure that a loop-closed PHI node for virtuals does exist.
Make sense. I think it would be good to add an explanation of what
this means in the comment before rewrite_into_loop_closed_ssa, because
"liveness" of a memory reference isn't as obvious as that of an ssa
register.
Did you try this with the header-copying change from PR46590 to make
it do only TODO_update_ssa_no_phi?
Ciao!
Steven