From: Alan Modra <amodra@gmail.com>
To: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Umesh Kalappa <umesh.kalappa0@gmail.com>,
Eric Botcazou <ebotcazou@adacore.com>,
gcc@gcc.gnu.org
Subject: Re: [PowerPC 64]r12 is not updated to GEP when control transferred from virtual thunk function .
Date: Mon, 20 May 2019 09:48:00 -0000 [thread overview]
Message-ID: <20190520094820.GO6820@bubble.grove.modra.org> (raw)
In-Reply-To: <20190520083950.GS31586@gate.crashing.org>
On Mon, May 20, 2019 at 03:39:50AM -0500, Segher Boessenkool wrote:
> But it means it needs to make a stub for every global entry point that
> is used?
Mostly. Calls via function pointer don't (*), nor do you need stubs
when generating inline PLT calls. I'll note that use of the global
entry point for direct calls is closely associated with needing a PLT
entry, and the stubs we're talking about here are similar to the code
other architectures put in their .plt section.
*) The exception is when a non-PIC executable initialises a function
pointer in read-only memory to a function defined outside the
executable. This case requires a special stub in the executable to
serve as the address of the function.
--
Alan Modra
Australia Development Lab, IBM
next prev parent reply other threads:[~2019-05-20 9:48 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-15 15:27 Umesh Kalappa
2019-05-15 16:05 ` Eric Botcazou
2019-05-15 17:47 ` Umesh Kalappa
2019-05-15 18:31 ` Eric Botcazou
2019-05-15 23:52 ` Segher Boessenkool
2019-05-16 3:30 ` Umesh Kalappa
2019-05-16 12:43 ` Umesh Kalappa
2019-05-16 22:52 ` Segher Boessenkool
2019-05-17 3:58 ` Umesh Kalappa
2019-05-20 6:50 ` Alan Modra
2019-05-20 7:55 ` Segher Boessenkool
2019-05-20 8:19 ` Alan Modra
2019-05-20 8:39 ` Segher Boessenkool
2019-05-20 9:48 ` Alan Modra [this message]
2019-05-15 23:37 ` Segher Boessenkool
2019-05-17 6:22 ` Kewen.Lin
2019-05-17 7:24 ` Eric Botcazou
2019-05-17 9:29 ` Kewen.Lin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190520094820.GO6820@bubble.grove.modra.org \
--to=amodra@gmail.com \
--cc=ebotcazou@adacore.com \
--cc=gcc@gcc.gnu.org \
--cc=segher@kernel.crashing.org \
--cc=umesh.kalappa0@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).