OpenImageIO/oiio — pull request #956 by fpsunflower (2014-09-12 22:11:05+00:00)
Title: Improve speed/quality of erf and erfc, add fast implementation of ierf

The previous erf implementation wasn't actually faster than the system one. This new one is.

Also adding a fast inverse error function implementation (not part of C99, but quite handy for certain BxDF sampling procedures)