CCS/OMAP-L138: MATHLIB vs MATHLIB_RTS

Part Number:OMAP-L138

Tool/software: Code Composer Studio

This URL lists both "mathlib" and "mathlib_rts"

 http ://software-dl.ti.com/sdoemb/sdoemb_public_sw/mathlib/latest/index_FDS.html

(sorry for the space, this editor does strange things with URLs)

What's the difference?  How do I know which one to use?  Or am I supposed to use both? (and in what order?)

The docs talk about adding -l mathlib.lib, but don't really give any indication about the differences between the two and whether one is better  or if you're supposed to use both.