Re: Compiler performance?

JP Rosevear (
Wed, 23 Jun 1999 11:36:39 -0400

Marc Campbell wrote:
> JP Rosevear replied:
> > > [1] Absoft Compilers:
> > I only see Intel versions listed on their pages and I assume its not
> > GPL'd so you can't use their stuff.
> Absoft C/C++ & Fortran compiler BACKEND on PowerPC.
> --> <--
> Absoft compiler FRONTEND on Linux.
> --> <--
> To rephrase the initial question,
> Q1. Does Absoft (or Metrowerks) have a performance or language compatibility advantage over stock PPC/Linux tools? Or, what would the potential gain be for working with Absoft (or Metrowerks) on a PPC/Linux release?

Well, for language compatibility gcc/egcs does support strict ANSI C as
well as its own extensions. I don't see anywhere mention of Fortran90
support for egcs at the website.

> Q2. For a dual boot system, could numerically optimized code be compiled on the MacOS side then moved and linked on the Linux side?

I doubt it. Maybe if you used the cross-compiling feature of gcc under
MacOS, but then why not just compile it under linux. The other factors
are that few if any compilers under MacOS probably know the ELF binary
format and even if they did you would have difficulty with shared
library loading and system calls.

> Q3. What compiler roadmap has the potential to achieved maximum *performance* on a G4/AltiVec? GPL would be nice, but in this case performance is job #1.

Unknown. In general I believe that to super-max performance you should
be looking at hand optimizing assembly like chess engine guys do. The
reason I had previously mentioned GPL is that then it might be possible
to port or pay somebody to port a better compiler for you.

Another option would be to look into the Black Labs G3 linux clusters
also sold be the YDL people to enhance performance.

I'm not a compiler god though so all this isn't gospel.

Dan, jump in here if I'm wrong.


JP Rosevear
Arcavia Software Ltd.
(905) 853-7714

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