Re: [OMPI devel] Build failures of 1.2.3 on Debian hppa, mips, mipsel, s390, m68k

[Brian Barrett <bbarrett@lanl.gov>]

On Jul 14, 2007, at 10:53 AM, Dirk Eddelbuettel wrote:

> Methinks we need to fill in a few blanks here, or make do with non-asm
> solutions. I don't know the problem space that well (being a  
> maintainer
> rather than upstream developer) and am looking for guidance.

Either way is an option.  There are really only a couple of functions  
that have to be implemented:

  * atomic word-size compare and swap
  * memory barrier

We'll emulte atomic adds and spin-locks with compare and swap if not  
directly implemented.  The memory barrier functions have to exist,  
even if they don't do anything.  We require compare-and-swap for a  
couple of pieces of code, which is why we lost our Sparc v8 support a  
couple of releases ago.

> For what it's worth, lam (7.1.2, currently) us available on all build
> architectures for Debian, but it may not push the (hardware)  
> envelope as
> hard.

Correct, LAM only had very limited ASM requirements (basically,  
memory barrier on platforms that required it -- like PowerPC).

Brian