If you ever run into troubles with a configure stranding on not finding -lm (math lib) you can remove the references in the configure file (or makefile after the compilation is trying to link)

If you plan to submit a patch you can add
cc_check $LDFLAGS $CXXFLAGS -lm && LDFLAGS="$LDFLAGS -lm"
this line to let other systems check and add -lm in the makefile and lets BeOS of the hook, be sure to remove -lm references still in the configure file.

This is one of the patches that went into the scummvm sourcetree.