I am happy to report that current llvm/llvm-gcc-4.2 svn
builds all of xplor-nih (a complex mix of c, c++ and fortran)
with -O3 -fPIC -msse4 -ffast-math. A single fortran file
exposes PR3376 which is triggered by -O3 -ffinite-math-only.
The resulting build of xplor-nih completely passes its testsuite
and compares very well to the same build against gcc trunk for
gcc 4.4 in terms of execution time.
gcc 4.4 llvm-gcc-4.2 svn
xplo 68.5205s 64.7649s
xplor-python 152.9726s 154.7344s
xplor-tcl 10.5005s 10.7039s