of Intel Itanium2 clusters for bioinformaticians to crank their data.
optimizing their performance. I'm using Intel C/C++ compiler on this
platform running Linux. One of my findings is that turning some
functions in R to "inline" functions boost performance significantly.
While R follows strict C89 standard right now, there're quite some good
reasons to relax the rule somewhat. From my experience in software
In R, there are quite some simple functions that are called extremely
often, such as "R_IsNaNorNA", "R_finite", etc. They are used in heavy
loops quite a lot. They disrupt the pipelining, and negatively affect
the performance of the software. For instance, on IA64, system call of
"isnan" cost 4 cycles, while a wrapper like "R_IsNaNorNA" could cost
several times more.