/**
* Update the value graph to account for a given IfCmp instruction.
*
* <p><b>PRECONDITION:</b> <code> IfCmp.conforms(s); </code>
*
* @param s the instruction in question
*/
private void processIfCmp(Instruction s) {
ValueGraphVertex v = new ValueGraphVertex(s);
graph.addGraphNode(v);
nameMap.put(s, v);
v.setLabel(s.operator(), 3);
link(v, findOrCreateVertex(bypassMoves(IfCmp.getVal1(s))), 0);
link(v, findOrCreateVertex(bypassMoves(IfCmp.getVal2(s))), 1);
link(v, findOrCreateVertex(IfCmp.getCond(s)), 2);
}
/**
* Update the value graph to account for a given GuardedBinary instruction.
*
* <p><b>PRECONDITION:</b> <code> GuardedBinary.conforms(s); </code> Careful: we define two
* Guarded Binaries to be equivalent regardless of whether the guards are equivalent!
*
* @param s the instruction in question
*/
private void processGuardedBinary(Instruction s) {
// label the vertex corresponding to the result with the operator
RegisterOperand result = GuardedBinary.getResult(s);
ValueGraphVertex v = findOrCreateVertex(result.getRegister());
v.setLabel(s.operator(), 2);
// link node v to the two operands it uses
// first link the first val
Operand val = GuardedBinary.getVal1(s);
val = bypassMoves(val);
link(v, findOrCreateVertex(val), 0);
Operand val2 = GuardedBinary.getVal2(s);
val2 = bypassMoves(val2);
link(v, findOrCreateVertex(val2), 1);
}
/**
* Update the value graph to account for a given InlineGuard instruction.
*
* <p><b>PRECONDITION:</b> <code> InlineGuard.conforms(s); </code>
*
* @param s the instruction in question
*/
private void processInlineGuard(Instruction s) {
ValueGraphVertex v = new ValueGraphVertex(s);
graph.addGraphNode(v);
nameMap.put(s, v);
if (s.operator() == IG_PATCH_POINT) {
// the 'goal' is irrelevant for patch_point guards.
v.setLabel(s.operator(), 1);
link(v, findOrCreateVertex(bypassMoves(InlineGuard.getValue(s))), 0);
} else {
v.setLabel(s.operator(), 2);
link(v, findOrCreateVertex(bypassMoves(InlineGuard.getValue(s))), 0);
link(v, findOrCreateVertex(InlineGuard.getGoal(s)), 1);
}
}
/**
* Update the value graph to account for a given NullCheck instruction.
*
* <p><b>PRECONDITION:</b> <code> ZeroCheck.conforms(s); </code>
*
* @param s the instruction in question
*/
private void processZeroCheck(Instruction s) {
// label the vertex corresponding to the result with the operator
RegisterOperand result = ZeroCheck.getGuardResult(s);
ValueGraphVertex v = findOrCreateVertex(result.getRegister());
v.setLabel(s.operator(), 1);
// link node v to the operand it uses
Operand val = ZeroCheck.getValue(s);
// bypass Move instructions
val = bypassMoves(val);
link(v, findOrCreateVertex(val), 0);
}
/**
* Update the value graph to account for a given Phi instruction.
*
* <p><b>PRECONDITION:</b> <code> Phi.conforms(s); </code>
*
* @param s the instruction in question
*/
private void processPhi(Instruction s) {
// the label for a PHI instruction is the basic block
// in which it appears
Register result = Phi.getResult(s).asRegister().getRegister();
ValueGraphVertex v = findOrCreateVertex(result);
BasicBlock bb = s.getBasicBlock();
v.setLabel(bb, bb.getNumberOfIn());
// link node v to all operands it uses
for (int i = 0; i < Phi.getNumberOfValues(s); i++) {
Operand val = Phi.getValue(s, i);
val = bypassMoves(val);
ValueGraphVertex target = findOrCreateVertex(val);
link(v, target, i);
}
}