private static void ForwardDFS(CFG cdfg,
ControlGraphQueries <EnhancedBasicBlock <Instruction>, Instruction> cfgQueries,
HashSet <EnhancedBasicBlock <Instruction> > currentPath,
HashSet <EnhancedBasicBlock <Instruction> > visitedBlocks,
Dictionary <EnhancedBasicBlock <Instruction>, List <EnhancedBasicBlock <Instruction> > > surroundingLoops,
EnhancedBasicBlock <Instruction> block)
{
if (visitedBlocks.Contains(block))
{
return;
}
visitedBlocks.Add(block);
currentPath.Add(block);
var successors = cdfg.SuccessorsFor(block);
//Console.WriteLine("{0:X}, Successors: {1}", block.Offset, Offsets(successors));
foreach (var s in successors)
{
if (currentPath.Contains(s))
{
// backedge from block to s
//WriteBlockOffset(s, 1);
if (!cfgQueries.Dominates(s, block))
{
throw new NotReducibleFlowGraph();
}
BackwardDFS(cdfg, cfgQueries, surroundingLoops, new HashSet <EnhancedBasicBlock <Instruction> >(), block, s);
}
else
{
ForwardDFS(cdfg, cfgQueries, currentPath, visitedBlocks, surroundingLoops, s);
}
}
currentPath.Remove(block);
}
private static void BackwardDFS(CFG cdfg,
ControlGraphQueries <EnhancedBasicBlock <Instruction>, Instruction> cfgQueries,
Dictionary <EnhancedBasicBlock <Instruction>, List <EnhancedBasicBlock <Instruction> > > surroundingLoops,
HashSet <EnhancedBasicBlock <Instruction> > visitedBlocks,
EnhancedBasicBlock <Instruction> block,
EnhancedBasicBlock <Instruction> loopHead)
{
if (visitedBlocks.Contains(block))
{
return;
}
visitedBlocks.Add(block);
List <EnhancedBasicBlock <Instruction> > loops;
if (!surroundingLoops.TryGetValue(block, out loops))
{
loops = new List <EnhancedBasicBlock <Instruction> >();
surroundingLoops.Add(block, loops);
}
surroundingLoops[block].Add(loopHead);
if (block == loopHead)
{
return;
}
var predecessors = cfgQueries.PredeccessorsFor(block);
//Console.WriteLine("{0:X}, Predecessors: {1}", block.Offset, Offsets(predecessors));
foreach (var p in predecessors)
{
BackwardDFS(cdfg, cfgQueries, surroundingLoops, visitedBlocks, p, loopHead);
}
}
private void InitializeOperandStack(EnhancedBasicBlock<Instruction> block) {
Contract.Requires(block != null);
this.operandStack.Clear();
foreach (var pseudoInstruction in block.OperandStack) {
Contract.Assume(pseudoInstruction != null);
this.PushTempForSlotAndAssociateWithInstruction(pseudoInstruction);
}
}
