public BitVector[] GetDominance( )
{
N[] idom = GetImmediateDominators();
int num = idom.Length;
BitVector[] res = BitVector.AllocateBitVectors(num, num);
for (int pos = 0; pos < num; pos++)
{
N node = m_nodesSpanningTree[pos];
var vec = res[pos];
while (true)
{
int idx = node.SpanningTreeIndex;
vec.Set(idx);
N next = idom[idx];
if (next == node)
{
break;
}
node = next;
}
}
return(res);
}
public BitVector[] GetDominanceFrontier( )
{
//
// This is an implementation of the algorithm in "A Simple, Fast Dominance Algorithm", by Keith D. Cooper, Timothy J. Harvey, and Ken Kennedy.
//
// "for all nodes, b
// if the number of predecessors of b >= 2
// for all predecessors, p, of b
// runner = p
// while runner != doms[b]
// add b to runner’s dominance frontier set
// runner = doms[runner]"
//
N[] idom = GetImmediateDominators();
int num = idom.Length;
BitVector[] res = BitVector.AllocateBitVectors(num, num);
for (int nodeBidx = 0; nodeBidx < num; nodeBidx++)
{
N nodeB = m_nodesSpanningTree[nodeBidx];
if (nodeB.Predecessors.Length >= 2)
{
foreach (var edge in nodeB.Predecessors)
{
N nodeP = (N)edge.Predecessor;
N runner = nodeP;
while (runner != idom[nodeBidx])
{
int idx = runner.SpanningTreeIndex;
res[idx].Set(nodeBidx);
runner = idom[idx];
}
}
}
}
return(res);
}
private void ComputeImmediatePostDominators( )
{
int len = m_nodes.Length;
BitVector[] tmp = BitVector.AllocateBitVectors(len, len);
for (int n = 0; n < len; n++)
{
// Tmp(n) := PostDomin(n) - {n}
tmp[n].Assign(m_postDominance[n]);
tmp[n].Clear(n);
}
for (int n = 0; n < len; n++) // Walk the basic blocks in pre-order.
{
// for each n in N do
BitVector tmpN = tmp[n];
for (int s = 0; s < len; s++)
{
if (tmpN[s])
{
// for each s in Tmp(n) do
BitVector tmpS = tmp[s];
for (int t = 0; t < len; t++)
{
if (t != s && tmpN[t])
{
// for each t in Tmp(n) - {s} do
if (tmpS[t])
{
// if t in Tmp(s) then Tmp(n) -= {t}
tmpN.Clear(t);
}
}
}
}
}
}
m_immediatePostDominators = new N[len];
for (int n = 0; n < len; n++)
{
bool fGot = false;
foreach (int idom in tmp[n])
{
CHECKS.ASSERT(fGot == false, "Internal failure, found more than one immediate post dominators");
m_immediatePostDominators[n] = m_nodes[idom];
fGot = true;
}
}
}
