Re: [Boost-build] Sunpro toolset

From: Michael van der Westhuizen (r1mikey_at_[hidden])
Date: 2006-06-22 03:26:29

Hi All,

On 6/22/06, Noel Belcourt <kbelco_at_[hidden]> wrote:
>
> On Jun 19, 2006, at 1:01 AM, Vladimir Prus wrote:
>
> > On Sunday 18 June 2006 04:02, Tomas Puverle wrote:
> >> In the sun.jam toolset file, I see the following code (this is HEAD in
> >> CVS):
> >>
> >> flags sun.compile OPTIONS <optimization>speed : -fast -xarch=generic ;
> >>
> >> Could you remove the -xarch=generic, please?  There are 2 reasons:
> >>
> >> 1)  When speccifying an architecture using -xarch/-xtarget, it needs
> >> to
> >> come before the compilation type (e.g. -fast) flags
>
> I think this is incorrect.  On the Sun, -fast will set or modify
> architecture specific settings.
>
>  From the Sun CC man page under the -fast description...
>
>                 Incorrect:
>
>                 example% CC -xarch=v9 -fast test.cc
>
>                 Correct:
>
>                 example% CC -fast -xarch=v9 test.cc
>
> So we always want -fast to precede architecture specific options like
> -xarch and -xtarget on the command line.

None of this is quite right if you want to distribute your libraries
or binaries, as -fast optimises for the machine you're compiling on,
not necessarily the machine your customers are running on.

See http://developers.sun.com/prodtech/cc/articles/options.html for
details of recommended options.
In short, this boils down to the following flags.

Recommended compiler flags for the UltraSPARC platform:
32-bit code: -xtarget=ultra3 -xarch=v8plusa
64-bit code: -xtarget=ultra3 -xarch=v9a

This generates code that will run on all UltraSPARC targets, but will
run best on USIII or higher.

Recommended compiler flags for the x64 platform:
32-bit code: -xtarget=opteron
64-bit code: -xtarget=opteron -xarch=amd64

I personally do not use the recommended 32 bit x64 settings, as we
still have a few PIII machines we need to build on, and
xtarget=opteron generates SSE2 code. We use the following for 32 bit:
-xtarget=pentium3 -xarch=sse -xchip=pentium3

Optimisation settings are can be set pretty high without risk on Sun
Studio compilers. We run most builds with -xO4 or -xO5.

Michael