xsl wrote:Not seeing the 40% speed-up though. Could it be just for linux (because of the slow expf())?
Yeah, that's likely. The slow expf is just for glibc (and apparently it has been patched very recently). You can see my windows timings here: viewtopic.php?p=81312#p81312 (compare the ratio between sinf and expf on windows and linux, it's two different cpus so can't compare directly).