Re: [PATCH 1/4] rtl-ssa: Run finalize_new_accesses forwards [PR113070]

[Alex Coplan <alex.coplan@arm.com>]

On 17/01/2024 07:42, Jeff Law wrote:
> 
> 
> On 1/13/24 08:43, Alex Coplan wrote:
> > The next patch in this series exposes an interface for creating new uses
> > in RTL-SSA.  The intent is that new user-created uses can consume new
> > user-created defs in the same change group.  This is so that we can
> > correctly update uses of memory when inserting a new store pair insn in
> > the aarch64 load/store pair fusion pass (the affected uses need to
> > consume the new store pair insn).
> > 
> > As it stands, finalize_new_accesses is called as part of the backwards
> > insn placement loop within change_insns, but if we want new uses to be
> > able to depend on new defs in the same change group, we need
> > finalize_new_accesses to be called on earlier insns first.  This is so
> > that when we process temporary uses and turn them into permanent uses,
> > we can follow the last_def link on the temporary def to ensure we end up
> > with a permanent use consuming a permanent def.
> > 
> > Bootstrapped/regtested on aarch64-linux-gnu, OK for trunk?
> > 
> > Thanks,
> > Alex
> > 
> > gcc/ChangeLog:
> > 
> > 	PR target/113070
> > 	* rtl-ssa/changes.cc (function_info::change_insns): Split out the call
> > 	to finalize_new_accesses from the backwards placement loop, run it
> > 	forwards in a separate loop.
> So just to be explicit -- given this is adjusting the rtl-ssa
> infrastructure, I was going to let Richard S. own the review side -- he
> knows that code better than I.

Yeah, that's fine, thanks.  Richard is away this week but back on Monday, so
hopefully he can take a look at it then.

Alex

> 
> Jeff