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From: "Martin Liška" <mliska@suse.cz>
To: Qing Zhao <qing.zhao@oracle.com>
Cc: "gcc-patches@gcc.gnu.org" <gcc-patches@gcc.gnu.org>,
	Jan Hubicka <hubicka@ucw.cz>
Subject: Re: [PATCH] IPA: support -flto + -flive-patching=inline-clone
Date: Wed, 5 Oct 2022 19:36:31 +0200	[thread overview]
Message-ID: <137fde8c-7ade-ecc0-96f2-9ec828b4745e@suse.cz> (raw)
In-Reply-To: <D6EF7EAA-479F-4ADD-9459-51130DF3EBEC@oracle.com>

On 10/5/22 16:50, Qing Zhao wrote:
> I have two questions on this:

Hello.

> 
> 1.  What’s the motivation to enable -flive-patching with -flto? Is there any application that will try -flive-patching with -flto now?

We're planning supporting GCC LTO Linux kernel support, so that's one motivation. And the second one is a possible
use in user-space livepatching. Note majority of modern distros default to -flto (openSUSE, Fedora, Debian, Ubuntu, ...).

> 
> 2. Why only enable -flive-patching=inline-clone with -flto?

Because the inline-only-static level (which you added/requested) would have to properly
block inter-procedural inlining that happens in LTO (can_inline_edge_by_limits_p) and
I'm not sure it would be properly blocked. So, feel free to extend my patch if you want?

Martin

> 
> thanks.


  reply	other threads:[~2022-10-05 17:36 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-05 11:41 Martin Liška
2022-10-05 14:50 ` Qing Zhao
2022-10-05 17:36   ` Martin Liška [this message]
2022-10-05 18:18     ` Qing Zhao
2022-10-06  8:29       ` Richard Biener
2022-10-06  8:40         ` Martin Liška
2022-10-06 13:18         ` Qing Zhao
2022-10-07  6:34           ` Richard Biener
2022-10-07 13:03             ` Jan Hubicka
2022-10-07 14:30               ` Qing Zhao
2022-10-07 14:43                 ` Jan Hubicka
2022-10-07 15:36                   ` Qing Zhao
2022-10-07 13:04             ` Qing Zhao
2022-10-07 13:50               ` Martin Liška

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