[petsc-dev] Building PETSc with PGI Compilers

[Dave Nystrom]

Jed Brown writes:
 > On Thu, Dec 22, 2011 at 23:52, Dave Nystrom <Dave.Nystrom at tachyonlogic.com> wrote:
 > 
 > > So, should I specify each of the compiler environment variables this way?
 > > That is,
 > >
 > > CC=/path/to/pgcc
 > > CXX=/path/to/pgCC
 > > FC=/path/to/pgfortran
 > 
 > Yes

OK.

 > > Should I also add --with-gnu-compilers=0 ?
 > 
 > Doesn't matter, you can drop this option entirely.

OK, I'll drop this one.

 > > > > I'm also interested in seeing what difference PETSc in general
 > > > > would see in performance for PGI versus GNU.
 > > >
 > > > I have always found PGI to be a waste of time.
 > >
 > > OK.  What about Intel or any other vendor compilers?
 > 
 > IBM compilers are mandatory on Blue Gene because the GCC people don't have
 > resources to optimize for that platform. Clang (open source, part of LLVM)
 > is totally worthwhile for the better error messages, and it has fully
 > compatible command line options to GCC. Intel compilers are usually fairly
 > straightforward to try. I usually don't see a big difference in end-to-end
 > performance, but sometimes Intel is a clear winner in micro-benchmarks. The
 > problem with PGI is that they are usually a bad user experience (weird
 > environment, poor diagonstics, often takes significant effort to build
 > code) and don't offer much if anything in performance. In contrast, Intel
 > compilers usually don't require much effort to try.

Thanks.  I appreciate this summary.  I'll have to try Clang sometime.