[PATCH] csa, postreload: Improve csa after recent cselib changes [PR94516]

[Jeff Law]

On Tue, 2020-05-05 at 09:38 +0200, Jakub Jelinek wrote:
> Hi!
> 
> On Wed, Apr 22, 2020 at 12:02:12PM -0600, Jeff Law via Gcc-patches wrote:
> > > Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
> > > 
> > > 2020-04-20  Jakub Jelinek  <jakub@redhat.com>
> > > 
> > > 	PR rtl-optimization/94516
> > > 	* postreload.c (reload_cse_simplify): When replacing sp = sp + const
> > > 	with sp = reg, add REG_EQUAL note with sp + const.
> > > 	* combine-stack-adj.c (try_apply_stack_adjustment): Change return
> > > 	type from int to bool.  Add LIVE and OTHER_INSN arguments.  Undo
> > > 	postreload sp = sp + const to sp = reg optimization if needed and
> > > 	possible.
> > > 	(combine_stack_adjustments_for_block): Add LIVE argument.  Handle
> > > 	reg = sp insn with sp + const REG_EQUAL note.  Adjust
> > > 	try_apply_stack_adjustment caller, call
> > > 	df_simulate_initialize_forwards and df_simulate_one_insn_forwards.
> > > 	(combine_stack_adjustments): Allocate and free LIVE bitmap,
> > > 	adjust combine_stack_adjustments_for_block caller.
> > I'd probably defer to gcc-11 since this is "just" a missed optimization and
> > we're
> > getting real close to cutting an RC and I'd hate to introduce new instability
> > at
> > this point.
> 
> Is the patch now ok for stage1?
Yes, of course.
jeff