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

[Jeff Law <jeffreyalaw@gmail.com>]

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.

Jeff