[cfe-commits] r154389 - in /cfe/trunk: lib/Driver/Tools.cpp test/Driver/linux-as.c

Tue Apr 24 01:10:46 PDT 2012

I think we should make sure the "universal driver" can deal with this, and remove the functionality then.

I'm actively working on this now (I was pre-February at which point I had a brief hiatus for the LLVM conference. Back on again.), and have a patch outstanding on the driver.

The problem with testing is a difficult one, but one I'm going to try and solve by building up a database of known driver behaviour - inputs and outputs - for both Clang in its current state and GCC on as many different platforms as I can find (I will be asking the community to help with this at some point).

>From there I can create a test suite that should run on any platform and test all platforms. The ideal goal being that the driver is "known to be as correct as GCC" on supported platforms, and easy to extend for nonsupported platforms.

For the moment, I think this commit should stay in place as-is, there's no point expending extra effort on it I don't think!

Cheers,

James

-----Original Message-----
From: Evgeniy Stepanov [mailto:eugeni.stepanov at gmail.com] 
Sent: 24 April 2012 08:59
To: James Molloy
Cc: Hal Finkel; cfe-commits at cs.uiuc.edu
Subject: Re: [cfe-commits] r154389 - in /cfe/trunk: lib/Driver/Tools.cpp test/Driver/linux-as.c

Not a hack, but unimplemented functionality.
Ideally, every other platform should also have a set of forwarded (and
maybe transformed) options, but I'm reluctant to do this now. I can't
test it easily, and I don't know enough about most of them to be sure
that I don't screw something up.
WDYT?

On Mon, Apr 23, 2012 at 6:12 PM, James Molloy <james.molloy at arm.com> wrote:
> It still sounds like a pretty dirty hack to get something to work in the interim.
>
> People will wonder why passing -mcpu only works for ARM and not for any other platform...
>
> -----Original Message-----
> From: cfe-commits-bounces at cs.uiuc.edu [mailto:cfe-commits-bounces at cs.uiuc.edu] On Behalf Of Hal Finkel
> Sent: 23 April 2012 15:08
> To: Evgeniy Stepanov
> Cc: cfe-commits at cs.uiuc.edu
> Subject: Re: [cfe-commits] r154389 - in /cfe/trunk: lib/Driver/Tools.cpp test/Driver/linux-as.c
>
> LGTM, thanks!
>
>  -Hal
>
> On Mon, 23 Apr 2012 16:53:41 +0400
> Evgeniy Stepanov <eugeni.stepanov at gmail.com> wrote:
>
>> Ok, I moved this options under if(arm).
>> Please take a look at the patch.
>>
>> On Mon, Apr 23, 2012 at 4:35 PM, Hal Finkel <hfinkel at anl.gov> wrote:
>> > On Mon, 23 Apr 2012 07:14:19 -0500
>> > Hal Finkel <hfinkel at anl.gov> wrote:
>> >
>> >> On Mon, 23 Apr 2012 11:14:04 +0400
>> >> Evgeniy Stepanov <eugeni.stepanov at gmail.com> wrote:
>> >>
>> >> > On Sun, Apr 22, 2012 at 5:41 AM, Hal Finkel <hfinkel at anl.gov>
>> >> > wrote:
>> >> > > Evgeniy,
>> >> > >
>> >> > > Unfortunately, we need to be much more careful here. While gas
>> >> > > for ARM does support -mcpu, -march and -mfpu, this is not true
>> >> > > for other ISAs. Looking at the man page, it seems that the
>> >> > > supported flags are:
>> >> > >
>> >> > > ARM: -mcpu=, -march=, -mfpu=
>> >> > > i386: -march= (-mtune=: should we map -mcpu= to -mtune=?)
>> >> > > MIPS: (same as i386)
>> >> > > PowerPC: supports cpu, but as -m<cpu> (meaning
>> >> > > -m403|-m405|-mppc64|...) SPARC: supports arch, but as -xarch=
>> >> > >
>> >> > > How do you think we should fix this?
>> >> >
>> >> > Well, we can make the set of forwarded options dependent on the
>> >> > target.
>> >>
>> >> That makes sense.
>> >>
>> >> >
>> >> > But what's the failing use case? I mean, why do you pass these
>> >> > options to the compiler in the first place?
>> >>
>> >> This patch broke building on PPC with a non-default cpu type. I
>> >> pass -mcpu=, as you do, to select appropriate cpu features and
>> >> itineraries. The default clang behavior on PPC is to pass -many to
>> >> the assembler. As you might imagine, this enables instructions for
>> >> all known cpu types. With this patch, the assembler also gets the
>> >> -mcpu=<cpu> flag provided to the driver. This is incorrect, it
>> >> would need to be translated as -m<cpu> for PPC. I think it is
>> >> unfortunate that gas cannot accept a common set of command-line
>> >> parameters across platforms, but that I cannot fix ;)
>> >
>> > I should also add that it is quite possible for LLVM to have
>> > itineraries for cpus that gas knows nothing about in particular.
>> >
>> >  -Hal
>> >
>> >>
>> >> Thanks again,
>> >> Hal
>> >>
>> >> >
>> >> > >
>> >> > >  -Hal
>> >> > >
>> >> > > On Tue, 10 Apr 2012 09:05:41 -0000
>> >> > > Evgeniy Stepanov <eugeni.stepanov at gmail.com> wrote:
>> >> > >
>> >> > >> Author: eugenis
>> >> > >> Date: Tue Apr 10 04:05:40 2012
>> >> > >> New Revision: 154389
>> >> > >>
>> >> > >> URL: http://llvm.org/viewvc/llvm-project?rev=154389&view=rev
>> >> > >> Log:
>> >> > >> Pass -march, -mcpu, -mfpu to linuxtools assembler.
>> >> > >>
>> >> > >> Added:
>> >> > >>     cfe/trunk/test/Driver/linux-as.c
>> >> > >> Modified:
>> >> > >>     cfe/trunk/lib/Driver/Tools.cpp
>> >> > >>
>> >> > >> Modified: cfe/trunk/lib/Driver/Tools.cpp
>> >> > >> URL:
>> >> > >> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Driver/Tools.cpp?rev=154389&r1=154388&r2=154389&view=diff
>> >> > >> ==============================================================================
>> >> > >> --- cfe/trunk/lib/Driver/Tools.cpp (original) +++
>> >> > >> cfe/trunk/lib/Driver/Tools.cpp Tue Apr 10 04:05:40 2012 @@
>> >> > >> -5089,6 +5089,10 @@ CmdArgs.push_back("-EL");
>> >> > >>    }
>> >> > >>
>> >> > >> +  Args.AddLastArg(CmdArgs, options::OPT_march_EQ);
>> >> > >> +  Args.AddLastArg(CmdArgs, options::OPT_mcpu_EQ);
>> >> > >> +  Args.AddLastArg(CmdArgs, options::OPT_mfpu_EQ);
>> >> > >> +
>> >> > >>    Args.AddAllArgValues(CmdArgs, options::OPT_Wa_COMMA,
>> >> > >>                         options::OPT_Xassembler);
>> >> > >>
>> >> > >>
>> >> > >> Added: cfe/trunk/test/Driver/linux-as.c
>> >> > >> URL:
>> >> > >> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Driver/linux-as.c?rev=154389&view=auto
>> >> > >> ==============================================================================
>> >> > >> --- cfe/trunk/test/Driver/linux-as.c (added) +++
>> >> > >> cfe/trunk/test/Driver/linux-as.c Tue Apr 10 04:05:40 2012 @@
>> >> > >> -0,0 +1,31 @@ +// Check passing options to the assembler for
>> >> > >> ARM targets. +//
>> >> > >> +// RUN: %clang -target arm-linux -### \
>> >> > >> +// RUN:   -no-integrated-as -c %s 2>&1 \
>> >> > >> +// RUN:   | FileCheck -check-prefix=ARM %s
>> >> > >> +// CHECK-ARM: as{{(.exe)?}}"
>> >> > >> +//
>> >> > >> +// RUN: %clang -target arm-linux -mcpu=cortex-a8 -### \
>> >> > >> +// RUN:   -no-integrated-as -c %s 2>&1 \
>> >> > >> +// RUN:   | FileCheck -check-prefix=ARM-MCPU %s
>> >> > >> +// CHECK-ARM-MCPU: as{{(.exe)?}}" "-mcpu=cortex-a8"
>> >> > >> +//
>> >> > >> +// RUN: %clang -target arm-linux -mfpu=neon -### \
>> >> > >> +// RUN:   -no-integrated-as -c %s 2>&1 \
>> >> > >> +// RUN:   | FileCheck -check-prefix=ARM-MFPU %s
>> >> > >> +// CHECK-ARM-MFPU: as{{(.exe)?}}" "-mfpu=neon"
>> >> > >> +//
>> >> > >> +// RUN: %clang -target arm-linux -march=armv7-a -### \
>> >> > >> +// RUN:   -no-integrated-as -c %s 2>&1 \
>> >> > >> +// RUN:   | FileCheck -check-prefix=ARM-MARCH %s
>> >> > >> +// CHECK-ARM-MARCH: as{{(.exe)?}}" "-march=armv7-a"
>> >> > >> +//
>> >> > >> +// RUN: %clang -target arm-linux -mcpu=cortex-a8 -mfpu=neon
>> >> > >> -march=armv7-a -### \ +// RUN:   -no-integrated-as -c %s 2>&1
>> >> > >> \ +// RUN:   | FileCheck -check-prefix=ARM-ALL %s
>> >> > >> +// CHECK-ARM-ALL: as{{(.exe)?}}" "-march=armv7-a"
>> >> > >> "-mcpu=cortex-a8" "-mfpu=neon" +//
>> >> > >> +// RUN: %clang -target armv7-linux -mcpu=cortex-a8 -### \
>> >> > >> +// RUN:   -no-integrated-as -c %s 2>&1 \
>> >> > >> +// RUN:   | FileCheck -check-prefix=ARM-TARGET %s
>> >> > >> +// CHECK-ARM-TARGET: as{{(.exe)?}}" "-mfpu=neon"
>> >> > >> "-mcpu=cortex-a8"
>> >> > >>
>> >> > >>
>> >> > >> _______________________________________________
>> >> > >> cfe-commits mailing list
>> >> > >> cfe-commits at cs.uiuc.edu
>> >> > >> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
>> >> > >
>> >> > >
>> >> > >
>> >> > > --
>> >> > > Hal Finkel
>> >> > > Postdoctoral Appointee
>> >> > > Leadership Computing Facility
>> >> > > Argonne National Laboratory
>> >>
>> >>
>> >>
>> >
>> >
>> >
>> > --
>> > Hal Finkel
>> > Postdoctoral Appointee
>> > Leadership Computing Facility
>> > Argonne National Laboratory
>
>
>
> --
> Hal Finkel
> Postdoctoral Appointee
> Leadership Computing Facility
> Argonne National Laboratory
>
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