[petsc-dev] Building PETSc with PGI Compilers

[Dave Nystrom]

Jed Brown writes:
 > On Thu, Dec 22, 2011 at 22:18, Dave Nystrom <dnystrom1 at comcast.net> wrote:
 > 
 > > --with-gnu-compilers=0 --with-vendor-compilers=pgi
 > 
 > --with-vendor-compilers=portland
 > 
 > just instructs BuildSystem to look for pgcc. You might be better off
 > specifying the path of the specific compiler you want to use:
 > 
 > CFLAGS=/path/to/pgcc

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

Should I also add --with-gnu-compilers=0 ?

 > > I want to try building PETSc with the PGI compilers so I can use vendor
 > > blas with the external direct solver packages.
 > 
 > This should definitely not be necessary. You should be able to link vendor
 > BLAS with any compiler.

Perhaps I should also try just doing this.

 > >  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?  Would you consider them
all to be a waste of time?  I tried Intel C++ on a C++ project I worked on
once but could not get it to beat g++.  However, I was running on AMD
processors and wondered if that might have been an issue.  I have gotten some
good speedups with vendor fortran.