Not so much a bug, as slow!

[boriel]

If SIN, COS, RND were libraries and not functions

I just realised - you do know I did all of those as libraries in the wiki, right?
Game versions, however; not very accurate. You may want to look at stuff like <!-- m --><a class="postlink" href="http://www.andreadrian.de/oldcpu/sincos.z80">http://www.andreadrian.de/oldcpu/sincos.z80</a><!-- m --> for better versions!

Of course I know, britlion!!
But I meant SIN, COS, RND are part of the BASIC Syntax (there are no #include nor import sentences to use these functions in a basic program: SIN, COS, etc are part of the language). So to maintain compatibility across platforms they must be defined within the compiler backend. I'm figuring out a solution for this (and yes, your functions could be also used as in C in the future).