From: Arnd Bergmann <arnd@arndb•de>
To: linuxppc-dev@ozlabs•org
Subject: Re: 440 ebony patch seems to have broken 85xx build on powerpc.git
Date: Thu, 24 May 2007 23:16:29 +0200 [thread overview]
Message-ID: <200705242316.29713.arnd@arndb.de> (raw)
In-Reply-To: <1180038295.3360.29.camel@zod.rchland.ibm.com>
On Thursday 24 May 2007, Josh Boyer wrote:
>=20
> > I think it should really use -mcpu=3Dpowerpc on all files.
> > The problem that Dave saw was the result of using a compiler
> > that defaults to -mcpu=3D8540, which uses instruction that
> > don't work on 440.
>=20
> You sure? =A0It griped about isel, and isel is implemented on all 440s
> with the exception of 440GP. =A0Yay for consistency.
strange indeed. -m440 does enable PPC_OPCODE_ISEL in the current
gas version, and probably all old ones as well.
> > The common files really need to be built with -mcpu flags that
> > make the code work on any system if you want to be able
> > to use just a single boot wrapper binary for all.
>=20
> Yeah, it's finding those combinations that work for all the existing
> toolchains out there that's the issue. =A0That, or making the wrapper not
> compile all the platform files... =A0I don't know which makes more sense.
I've looked up the gas source and found two ways that allow us to
compile everywhere:
1. Pass -Wa,-many to gcc
This will really allow any possible instruction to be assembled, including
the old POWER architecture, but also includes all the other strange
stuff like -maltivec, -mspe, -me500, ...
2. protect the use of special instructions with .machine directives.
You can write all the inline assemblies like
.machine push
.machine 440
<440 specific instruction>
.machine pop
This should work in any reasonably recent version of binutils, meaning
that we don't need to pass stuff like -Wa,-m440 any more.
Arnd <><
next prev parent reply other threads:[~2007-05-24 21:16 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-24 17:13 440 ebony patch seems to have broken 85xx build on powerpc.git Dave Jiang
2007-05-24 17:37 ` Josh Boyer
2007-05-24 17:43 ` Dave Jiang
2007-05-24 18:02 ` Sergei Shtylyov
2007-05-24 18:09 ` Josh Boyer
2007-05-25 1:27 ` David Gibson
2007-05-24 19:05 ` Segher Boessenkool
2007-05-24 19:39 ` Josh Boyer
2007-05-24 20:18 ` Segher Boessenkool
2007-05-24 20:21 ` Arnd Bergmann
2007-05-24 20:24 ` Josh Boyer
2007-05-24 21:07 ` Mark A. Greer
2007-05-24 21:16 ` Arnd Bergmann [this message]
2007-05-24 22:08 ` Segher Boessenkool
2007-05-24 22:03 ` Segher Boessenkool
2007-05-24 22:02 ` Segher Boessenkool
2007-05-25 1:30 ` David Gibson
2007-05-25 14:01 ` Segher Boessenkool
2007-05-24 22:09 ` Segher Boessenkool
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