https://bugs.freedesktop.org/show_bug.cgi?id=64257
--- Comment #68 from Alex Deucher agd5f@yahoo.com --- Trig functions need slightly different setup on r6xx and r7xx+. See tgsi_setup_trig() in r600_shader.c:
/* * r600 - trunc to -PI..PI range * r700 - normalize by dividing by 2PI * see fdo bug 27901 */