How do I configure PETSc to run long double precision or some other precision that is greater than default? [closed]

I'm installing PETSc for complex numbers with the C99 standard. I'd like to have it installed using a higher precision than the default (double, I presume) since that will most likely make the LU preconditioner run better. I've tried several different commands that I could google, but it doesn't work. I've searched the manual but haven't found anything on the subject.

I tried invoking ./configure with the

precision=longdobule

and

precision=__float128

with

in all four different combinations. The one time I used download-f2cblaslapack and precision=__float128 it did configure successfully but at the next stage when I compiled the libraries I got the following error for every library being compiled:
• this sounds like a bug in PETSc itself. Can you send the complete configure and make/test logs to petsc-maint@mcs.anl.gov for the case where you specified: --with-precision=__float128 --download-f2cblaslapack (as suggested by the PETSc documentation here). – Aron Ahmadia Aug 2 '12 at 12:57