https://bugs.winehq.org/show_bug.cgi?id=55154
--- Comment #3 from Nikolay Sivov bunglehead@gmail.com --- Those are different. For 'tan' we have now sin(x) / cos(x), where sin and cos are expected to be supported as separate instructions. 'acos' however uses approximation. If you don't get compilation errors, we can consider it working for now.