/**
* Construct a value graph from an IR.
*
* <p><b> PRECONDITION:</b> The IR <em> must </em> be in SSA form.
*
* @param ir the IR
*/
ValueGraph(IR ir) {
graph = new SpaceEffGraph();
nameMap = new HashMap<Object, ValueGraphVertex>();
// TODO!!: compute register lists incrementally
// we need register lists in order to call Register.getFirstDef()
DefUse.computeDU(ir);
// add value graph nodes for each symbolic register
addRegisterNodes(ir);
// go through the IR and add nodes and edges to the value graph
// for each instruction, as needed
for (Enumeration<Instruction> e = ir.forwardInstrEnumerator(); e.hasMoreElements(); ) {
Instruction s = e.nextElement();
processInstruction(s);
}
computeClosure();
}
