From: Felix Domke <tmbinc@elitedvb.net>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: linuxppc-dev list <linuxppc-dev@ozlabs.org>
Subject: Re: Saving to 32 bits of GPRs in signal context
Date: Wed, 30 May 2007 13:52:29 +0200 [thread overview]
Message-ID: <1180525953.1F02B585@fk13.dngr.org> (raw)
In-Reply-To: <1180524227.19517.256.camel@localhost.localdomain>
>> Anyway, please don't. It is *not* portable.
> What are you talking about ? Really, I mean, I'm not sure I understand
> what you mean :-)
Segher stated that there is no portable way of detecting whether 64bit
instructions are available, and said that just trying a 64bit insn (and
catching the SIGILL if thre cpu is 32bit) is probably the most portable
way to do so. (Or did i got *that* wrong? If so, please ignore.)
Now my objection is that the "SIGILL"-way is not only ugly, but can be
easily *wrong*, as there are certain possibilities (Book-E 64bit,
non-64bit-aware OS, ...) when the CPU might not throw an exception. (My
"ffmpeg with vmx"-experience shows this is a real world issue, although
the situation is a bit different there, i agree, since vmx opcodes are
not exclusively reserved for vmx)
Yes, those hwcap-bits should care for this. Are they portable/usable,
even on older systems?
Felix
next prev parent reply other threads:[~2007-05-30 12:52 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-29 7:24 Saving to 32 bits of GPRs in signal context Benjamin Herrenschmidt
2007-05-29 7:52 ` Dan Malek
2007-05-29 8:05 ` Benjamin Herrenschmidt
2007-05-29 9:26 ` Gabriel Paubert
2007-05-29 9:44 ` Benjamin Herrenschmidt
2007-05-29 13:12 ` Segher Boessenkool
2007-05-29 14:00 ` Steve Munroe
2007-05-29 14:08 ` Ulrich Weigand
2007-05-29 14:17 ` Kumar Gala
2007-05-29 14:38 ` Segher Boessenkool
2007-05-29 19:04 ` Becky Bruce
2007-05-30 10:04 ` Christoph Hellwig
2007-05-30 12:13 ` Kumar Gala
2007-05-30 12:30 ` Segher Boessenkool
2007-05-29 14:31 ` Segher Boessenkool
2007-05-29 14:51 ` Steve Munroe
2007-05-29 21:44 ` Benjamin Herrenschmidt
2007-05-29 23:16 ` Steve Munroe
2007-05-29 23:19 ` Benjamin Herrenschmidt
2007-05-30 7:34 ` Hiroyuki Machida
2007-05-30 11:40 ` Segher Boessenkool
2007-05-30 11:48 ` Benjamin Herrenschmidt
2007-05-30 3:37 ` Paul Mackerras
2007-05-30 5:32 ` Kumar Gala
2007-05-30 11:44 ` Benjamin Herrenschmidt
2007-05-30 12:15 ` Kumar Gala
2007-05-30 12:48 ` Hiroyuki Machida
2007-05-30 12:58 ` Benjamin Herrenschmidt
2007-05-30 18:09 ` Steve Munroe
2007-05-30 21:02 ` Gabriel Paubert
2007-05-30 21:41 ` Steve Munroe
2007-05-30 12:01 ` Segher Boessenkool
2007-05-30 11:59 ` Segher Boessenkool
2007-05-30 12:01 ` Benjamin Herrenschmidt
2007-05-30 12:07 ` Segher Boessenkool
2007-05-30 12:09 ` Benjamin Herrenschmidt
2007-05-30 12:36 ` Segher Boessenkool
2007-05-29 14:28 ` Segher Boessenkool
2007-05-29 21:37 ` Benjamin Herrenschmidt
2007-05-29 21:38 ` Benjamin Herrenschmidt
2007-05-29 13:04 ` Segher Boessenkool
2007-05-29 14:28 ` Arnd Bergmann
2007-05-29 14:43 ` Segher Boessenkool
2007-05-29 15:54 ` Geert Uytterhoeven
2007-05-29 18:48 ` Arnd Bergmann
2007-05-29 21:27 ` Benjamin Herrenschmidt
2007-05-29 21:45 ` Felix Domke
2007-05-30 11:23 ` Benjamin Herrenschmidt
2007-05-30 11:52 ` Felix Domke [this message]
2007-05-30 13:14 ` Segher Boessenkool
2007-05-30 11:54 ` Segher Boessenkool
2007-05-30 12:07 ` Felix Domke
2007-05-31 5:39 ` Benjamin Herrenschmidt
2007-05-29 13:10 ` Kumar Gala
2007-05-29 21:32 ` Benjamin Herrenschmidt
2007-05-29 23:46 ` Olof Johansson
2007-05-30 0:43 ` Kumar Gala
2007-05-30 2:54 ` Steve Munroe
2007-05-30 5:31 ` Kumar Gala
2007-05-30 19:47 ` Steve Munroe
2007-05-30 20:52 ` Olof Johansson
2007-05-30 21:33 ` Steve Munroe
2007-05-29 13:53 ` Ulrich Weigand
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