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From: Alan Modra <amodra@gmail.com>
To: Richard Henderson <rth@redhat.com>
Cc: "Lynn A. Boger" <laboger@linux.vnet.ibm.com>,
	gcc-patches@gcc.gnu.org,	libffi-discuss@sourceware.org,
	gofrontend-dev@googlegroups.com
Subject: Re: [PATCH 00/13] Go closures, libffi, and the static chain
Date: Thu, 06 Nov 2014 12:48:00 -0000	[thread overview]
Message-ID: <20141106124838.GJ30857@bubble.grove.modra.org> (raw)
In-Reply-To: <545B1C44.3000306@redhat.com>

On Thu, Nov 06, 2014 at 07:59:16AM +0100, Richard Henderson wrote:
> I haven't done powerpc yet.  If you'd like to help, I'd be delighted.

I was going to say that it doesn't look too difficult, but then I
noticed we have a problem.  PowerPC uses r11 as the static chain,
a register that is allowed to be used by linkage stubs.

So any call to a shared libffi will (or may) blow away r11.  On ppc32,
every plt call currently uses r11.  On ppc64 ELFv1 most plt calls do
(in fact r11 is loaded from the third word of the plt function
descriptor if using a standard plt stub).  On ppc64 ELFv2 just the
lazy plt resolution trashes r11.

-- 
Alan Modra
Australia Development Lab, IBM

  reply	other threads:[~2014-11-06 12:48 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-10-10 20:43 Richard Henderson
2014-10-10 20:43 ` [PATCH 12/13] libffi: Rewrite i386 sysv Richard Henderson
2014-10-10 20:43 ` [PATCH 10/13] libffi: Rewrite aarch64 Richard Henderson
2014-10-10 20:43 ` [PATCH 05/13] libgo: Use the static chain for the closure Richard Henderson
2014-10-10 20:43 ` [PATCH 04/13] Use the static chain as the closure parameter from Go Richard Henderson
2014-10-10 20:43 ` [PATCH 11/13] libffi: Support go closures on aarch64 Richard Henderson
2014-10-10 20:43 ` [PATCH 06/13] libffi: Add entry points for interacting with Go Richard Henderson
2014-10-10 20:43 ` [PATCH 03/13] HACK! Allow the static chain to be set from C Richard Henderson
2014-10-11  0:33   ` Ian Lance Taylor
     [not found]     ` <CAMn1gO7vJOcNi218p9m32de_rrnKBrUcGF-EKP3dJwaL+8BtUw@mail.gmail.com>
2014-10-11  1:42       ` [gofrontend-dev] " Peter Collingbourne
2014-10-11  4:24         ` Richard Henderson
2014-10-13  8:10           ` Richard Biener
2014-10-13 18:46             ` Peter Collingbourne
2014-10-14 18:44   ` [PATCH v2 03/13] " Richard Henderson
2014-10-10 20:43 ` [PATCH 13/13] libffi: Support go closures on i386 Richard Henderson
2014-10-10 20:43 ` [PATCH 01/13] Make TARGET_STATIC_CHAIN allow a function type Richard Henderson
2014-10-10 20:43 ` [PATCH 09/13] libgo: Remove __go_get/set_closure Richard Henderson
2014-10-10 20:43 ` [PATCH 07/13] libffi: Support go closures on x86_64 Richard Henderson
2014-10-10 20:43 ` [PATCH 02/13] Allow the front-end to create calls with a static chain Richard Henderson
2014-10-10 20:43 ` [PATCH 08/13] libgo: Use the new libffi interfaces for Go Richard Henderson
2014-10-11  0:23 ` [PATCH 00/13] Go closures, libffi, and the static chain Ian Lance Taylor
2014-11-05 21:34 ` Lynn A. Boger
2014-11-06  6:59   ` Richard Henderson
2014-11-06 12:48     ` Alan Modra [this message]
2014-11-06 13:04       ` Richard Henderson
2014-11-06 17:45         ` [gofrontend-dev] " Ian Taylor
2014-11-07  7:39           ` Richard Henderson
2014-11-07  8:50             ` Jay
2014-11-07 16:06             ` Ian Taylor
2014-11-07 23:55               ` Alan Modra
2014-11-06 13:10       ` Lynn A. Boger
2014-11-06 13:17         ` Richard Henderson
2014-12-11  9:06 ` Dominik Vogt
2014-12-11  9:21   ` Alan Modra
2014-12-11 10:31     ` [gofrontend-dev] " Dominik Vogt
2014-12-11 12:25       ` Dominik Vogt
2014-12-11 19:56         ` Richard Henderson
2014-12-12 12:06           ` Dominik Vogt
2014-12-12 18:14             ` Richard Henderson
2014-12-15  9:42               ` Dominik Vogt
2014-12-15 20:11                 ` Richard Henderson
2014-12-12 13:57     ` Dominik Vogt
2014-12-11 19:38   ` Richard Henderson

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