Re: gcc & g4 processor?

Re: gcc & g4 processor?

[Mike Stump]

> Date: Mon, 7 May 2001 11:28:48 -0400
> From: adam morley <axm135@po.cwru.edu>
> To: gcc@gcc.gnu.org

> so i was looking @ apples website, specifically what compiler they
> include with the now shipping Mac OS X.  its gcc 2.95.2.  it has a
> special option -faltivec to compile with altivec enhancements.

> is this included in regular download of gcc from one of the mirrors?

No, that work isn't important enough in the eyes of the people that
did the work to have submitted it back yet.  In time, maybe someone
will do this.  (I'd be happy to be corrected on this point.)

> ie, can i put it on linux ppc, openbsd, whatever, compile it and get
> that action?

If you use the modified compiler, yes.

Re: gcc & g4 processor?

[Stan Shebs]

adam morley wrote:
> 
> so i was looking @ apples website, specifically what compiler they include with the now shipping Mac OS X.  its gcc 2.95.2.  it has a special option -faltivec to compile with altivec enhancements.
> 
> is this included in regular download of gcc from one of the mirrors?  ie, can i put it on linux ppc, openbsd, whatever, compile it and get that action?

Go to www.altivec.org, register yourself, and download from there;
they have GCC and binutils that handle AltiVec and also run on LinuxPPC
etc.  The same code is in LinuxPPC distros.  All are based on the same
set of Motorola-written patches that Apple's shipping compiler uses.

Much of this code is useless for 3.x however, because of all the
internal changes.  Sam Figueroa has been making good progress on
rewriting things, and we're still pursuing the copyright assignment
angle in the hopes that we won't have to rewrite absolutely
everything from scratch.  But Apple is committed to contributing
full AltiVec support to FSF GCC, one way or another.

Stan

Re: gcc & g4 processor?

[David Edelsohn]

>>>>> adam morley writes:

adam> interesting.  this brings up another point: will there be support
for things like VIS from sun?  i know sun already has a compiler which
does a very very good job of optimizing, so i doubt if sun would build
support into gcc. 

	The GCC infrastructure supports any SIMD/vector-like extensions.
It is up to Sun whether they want to implement the functionality for GCC.

adam> and im guessing this doesn't run under openbsd.

	IBM's Visual Age compilers currently do not produce code for *BSD
or GNU/Linux systems.

David

Re: gcc & g4 processor?

[adam morley]

On Mon, May 07, 2001 at 12:51:58PM -0400, David Edelsohn wrote:
> >>>>> adam morley writes:
> 
> adam> so i was looking @ apples website, specifically what compiler they
> include with the now shipping Mac OS X.  its gcc 2.95.2.  it has a special
> option -faltivec to compile with altivec enhancements. 
> adam> is this included in regular download of gcc from one of the mirrors?
> ie, can i put it on linux ppc, openbsd, whatever, compile it and get that
> action? 
> 
> 	Motorola has not assigned the changes to the FSF, so they cannot
> be included in the FSF sources.  In the interim, the GCC infrastructure
> for supporting SIMD instructions has been improved by an Intel contract
> with Red Hat to support MMX/SSE instructions.  Apple has stated that it is
> investigating rewriting the AltiVec support from scratch without any
> Motorola IP using the new GCC SIMD infrastructure.

interesting.  this brings up another point: will there be support for things like VIS from sun?  i know sun already has a compiler which does a very very good job of optimizing, so i doubt if sun would build support into gcc.

is there a timetable for apple's altivec support?

> 
> adam> plus, how good is PPC optimization under gcc?
> 
> 	Good, not great.  It depends a lot on the type of algorithm.
> Informal performance comparisons seem to show that GCC is anywhere from
> 30% worse to 5% better than IBM's Visual Age compiler on specific
> workloads.

and im guessing this doesn't run under openbsd.

> 
> David

-- 
thanks
adam

any and all ideas herein are the sole property of the author, with no implied warranties or guarantees.  unless its somebody else's already.

Re: gcc & g4 processor?

[David Edelsohn]

>>>>> adam morley writes:

adam> so i was looking @ apples website, specifically what compiler they
include with the now shipping Mac OS X.  its gcc 2.95.2.  it has a special
option -faltivec to compile with altivec enhancements. 
adam> is this included in regular download of gcc from one of the mirrors?
ie, can i put it on linux ppc, openbsd, whatever, compile it and get that
action? 

	Motorola has not assigned the changes to the FSF, so they cannot
be included in the FSF sources.  In the interim, the GCC infrastructure
for supporting SIMD instructions has been improved by an Intel contract
with Red Hat to support MMX/SSE instructions.  Apple has stated that it is
investigating rewriting the AltiVec support from scratch without any
Motorola IP using the new GCC SIMD infrastructure.

adam> plus, how good is PPC optimization under gcc?

	Good, not great.  It depends a lot on the type of algorithm.
Informal performance comparisons seem to show that GCC is anywhere from
30% worse to 5% better than IBM's Visual Age compiler on specific
workloads.

David

gcc & g4 processor?

[adam morley]

so i was looking @ apples website, specifically what compiler they include with the now shipping Mac OS X.  its gcc 2.95.2.  it has a special option -faltivec to compile with altivec enhancements.

is this included in regular download of gcc from one of the mirrors?  ie, can i put it on linux ppc, openbsd, whatever, compile it and get that action?  

plus, how good is PPC optimization under gcc?

thanks!

-- 
thanks
adam

any and all ideas herein are the sole property of the author, with no implied warranties or guarantees.  unless its somebody else's already.