http://bugs.winehq.org/show_bug.cgi?id=7284
--- Comment #47 from Stefan Dösinger stefandoesinger@gmx.at 2009-05-03 19:47:38 --- Take a look at the RCC instruction defined in GL_NV_vertex_program1_1 . It has some interesting language concerning this bug. We can't use this instruction in our ARB shaders as-is, but the spec may provide some hints.