+ <dt><a name="Safe_Point"><b>Safe Point</b></a></dt>
+ <dd>In garbage collection, it is necessary to identify <a href="#Root">stack
+ roots</a> so that reachability analysis may proceed. It may be infeasible to
+ provide this information for every instruction, so instead the information
+ may is calculated only at designated safe points. With a copying collector,
+ <a href="#Derived_Pointers">derived pointers</a> must not be retained across
+ safe points and <a href="#Object_Pointers">object pointers</a> must be
+ reloaded from stack roots.</dd>
+ <dt><a name="SDISel"><b>SDISel</b></a></dt>
+ <dd>Selection DAG Instruction Selection.</dd>
+ <dt><a name="SCC"><b>SCC</b></a></dt>
+ <dd>Strongly Connected Component</dd>