imageworks/OpenShadingLanguage — pull request #141 by lgritz (2012-05-30 21:03:40+00:00)
Title: Bug fix to Gabor noise -- we inadvertently used undefined order of evaluation

C and C++ do not specify the order in which function parameters are evaluated.
So in our Gabor implementation, we had this:

Vec3 x_i_c (rng(), rng(), rng());

The rng() is stateful. gcc evaluated them right-to-left, but we discovered
the problem when compiling with clang, which evaluates left-to-right, thus
giving us a totally different noise seed!