From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <SRS0=Dzoh=6G=troutmask.apl.washington.edu=sgk@sourceware.org>
Received: from troutmask.apl.washington.edu (troutmask.apl.washington.edu [128.95.76.21])
	by sourceware.org (Postfix) with ESMTPS id 237663858414
	for <fortran@gcc.gnu.org>; Fri, 10 Feb 2023 18:53:12 +0000 (GMT)
DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 237663858414
Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=troutmask.apl.washington.edu
Authentication-Results: sourceware.org; spf=none smtp.mailfrom=troutmask.apl.washington.edu
Received: from troutmask.apl.washington.edu (localhost [127.0.0.1])
	by troutmask.apl.washington.edu (8.16.1/8.16.1) with ESMTPS id 31AIrAeZ078459
	(version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NO);
	Fri, 10 Feb 2023 10:53:10 -0800 (PST)
	(envelope-from sgk@troutmask.apl.washington.edu)
Received: (from sgk@localhost)
	by troutmask.apl.washington.edu (8.16.1/8.16.1/Submit) id 31AIrA81078458;
	Fri, 10 Feb 2023 10:53:10 -0800 (PST)
	(envelope-from sgk)
Date: Fri, 10 Feb 2023 10:53:10 -0800
From: Steve Kargl <sgk@troutmask.apl.washington.edu>
To: Rimvydas Jasinskas <rimvydasjas@gmail.com>
Cc: Rimvydas Jasinskas via Fortran <fortran@gcc.gnu.org>
Subject: Re: Support for NOINLINE attribute
Message-ID: <Y+aSlsgPmcyVqkB8@troutmask.apl.washington.edu>
Reply-To: sgk@troutmask.apl.washington.edu
References: <CAFmAMQ1KXtMfR=jPjKpBQfBp=RxFWNWZ23EhjMe=C8GjUBZBwA@mail.gmail.com>
 <Y+X/OIyBsVRZHAKW@troutmask.apl.washington.edu>
 <CAFmAMQ09jLG_jFwNy+0SLhLd5gCWys0M8Jm+2bZGt0418KQBGg@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <CAFmAMQ09jLG_jFwNy+0SLhLd5gCWys0M8Jm+2bZGt0418KQBGg@mail.gmail.com>
X-Spam-Status: No, score=-1.6 required=5.0 tests=BAYES_00,KAM_DMARC_STATUS,KAM_LAZY_DOMAIN_SECURITY,SPF_HELO_NONE,SPF_NONE,TXREP autolearn=no autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org
List-Id: <fortran.gcc.gnu.org>

On Fri, Feb 10, 2023 at 10:38:04AM +0200, Rimvydas Jasinskas wrote:
> On Fri, Feb 10, 2023 at 10:24 AM Steve Kargl via Fortran
> <fortran@gcc.gnu.org> wrote:
> > > would it be possible to extend gfortran attribute support to handle
> > > NOINLINE too? Like: "!GCC$ ATTRIBUTES noinline :: ...".
> >
> > It looks to me like you are conflating three independent topics.
> > What does NOINLINE have to do with WEAK?  What does WEAK have
> > to do with NORETURN?
> 
> As I wrote these are optional (different issues, quite useful to have
> but still easy to work around with different means), the main issue is
> still missing NOINLINE for -flto.

Unfortunately, conflating unrelated topics can lead to distraction.
I do however see value in NORETURN.  I suppose a person writing a
library may find WEAK useful.

> > More importantly what is the effect of NOINLINE if a user
> > does not specify the -flto option?  Does this block inlining
> > regardless of LTO?
> >
> > --
> > steve
> Yes, there is no way to differentiate between LTO and non-LTO
> compilations (at least from what I have seen in the code).
> As long as subroutines/functions are in separate compilation units,
> this has no effect for non-LTO builds anyway.  Main issue is to deal
> with unintentional over inlining between different compilation units
> with lto1 backend.

I haven't studied your patch in detail, so apologies up front
if this is already available.  Can attribute be applied to only
a block of code in a file?.  Suppose there are 3 functions in a
file.  Can the attribute be toggled on and off? Something like


function bar()
...
end function bar()

!GCC$ ATTRIBUTES noinline on
function foo()
...
end function foo()
!GCC$ ATTRIBUTES noinline off

function bah()
...
end function bah()

bar() and bah() can be inlined while inlining foo() is prevented.

-- 
Steve