public static IGate ExtractCommonFactors(IGate gate)
{
var original = gate;
if (gate.Type == GateType.OR)
{
// TraceOptimize("extract common factors from {0} ...", gate);
var sop = gate.GetSOP();
// count how many times each factor appears
var inmap = new Dictionary<int, IInput>();
var dict = new SortedList<int, int>();
foreach (var p in sop.GetPrimitiveFactors())
{
// a gate representing the factors (may be multiple per state variable)
var pg = p.ToGate();
foreach (var i in pg.GetInputs().OfType<IInput>())
{
var address = i.Address;
// TraceOptimize("check factor {0} @ {1:X6}", i, address);
if (!inmap.ContainsKey(i.Address))
{
inmap.Add(i.Address, i);
}
if (!dict.ContainsKey(address))
{
dict[address] = 1;
}
else
{
dict[address]++;
}
}
}
var m = dict.Values.Max();
// TraceOptimize("maximum factor count {0}", m);
if (m > 1)
{
// go for it, take the first input with maximum multiplicity, inputs are ordered.
var pivotindex = dict.Where(e => e.Value == m).Select(e => e.Key).First();
var pivot = inmap[pivotindex];
var pivotlist = new List<Product>();
var otherlist = new List<Product>();
TraceOptimize("use pivot {0:X6} ...", pivot);
// split sop into two groups: factor or not
foreach (var p in sop)
{
if (p.ContainsFactor(pivot))
{
p.RemoveInput(pivot);
pivotlist.Add(p);
}
else
{
otherlist.Add(p);
}
}
IGate and = new ANDGate();
and.AddInput(pivot);
IGate inneror = new ORGate();
foreach (var p in pivotlist)
{
var z = p.ToGate().Simplify();
// Debug.Assert(z.GetInputs().Count() > 1);
Trace("adding pivot {0} [{1}]", z, z.GetType().Name);
inneror.AddInput(z);
}
inneror = ExtractCommonFactors(inneror);
and.AddInput(inneror);
if (otherlist.Any())
{
//var rh = ExtractCommonFactors(otherlist);
var or = new ORGate();
or.AddInput(and);
foreach (var p in otherlist)
{
var z = p.ToGate();
or.AddInput(z.Simplify());
}
gate = or;
}
else
{
gate = and;
}
}
}
if (gate != original && TraceFlags.ShowOptimize)
{
Log.TraceGateOp2(original, gate, "optimize AND");
}
return gate;
}
/// <summary>
/// Looks for common subfactors.
/// </summary>
/// <param name="gate"></param>
private bool SimplifyRule2(ref IGate gate)
{
var originalgate = gate;
var gset = gate.GetSOP();
// try all elementary factors ...
foreach (var elementaryfactor in gset.GetPrimitiveFactors().ToArray())
{
// Trace("trying factor {0}", elementaryfactor);
// collect all products that contain the factor as candidates
var candidates = new List<Product>();
foreach (var p in gset)
{
if (1 == p.ContainsFactor(elementaryfactor))
{
candidates.Add(p);
}
}
// need at least two
if (candidates.Count < 2)
{
continue;
}
TraceSimplify("common factor {0} found in {1} ...", elementaryfactor, candidates.ToSeparatorList());
// construct a new gate consisting of the sum of remaining products
var reducedsum = new ORGate();
Gate newgate = reducedsum;
foreach (var involvedproduct in candidates)
{
var reducedproduct = involvedproduct.Clone();
reducedproduct.Remove(elementaryfactor);
if (reducedproduct.Factors.Any())
{
reducedsum.AddInput(reducedproduct.ToGate());
}
else
{
// candidate equals elementary factor => TRUE
newgate = new TrueGate();
break;
}
}
// remove original elements from the set
foreach (var x in candidates)
{
gset.Remove(x);
}
// simplify the resulting gate recursively
var partialsum = newgate.Simplify();
var factor = elementaryfactor.ToGate();
TraceSimplify(" is ({0}) AND {1}", partialsum, factor);
if (partialsum.Type == GateType.Fixed)
{
if (partialsum is TrueGate)
{
// factor only
gate = factor;
}
else
{
// simplification yields FALSE
gate = partialsum;
}
}
else if (partialsum.Type == GateType.AND)
{
// multiply with factor
gate = Gate.Multiply(factor.GetInputs(), partialsum);
}
else if (partialsum.Type == GateType.OR)
{
// multiply with all factors
gate = Gate.Multiply(factor.GetInputs(), partialsum.GetInputs());
}
else
{
// multiply with factor
gate = Gate.Multiply(factor.GetInputs(), partialsum);
}
// compose with the remaining terms
foreach (var term in gset.Select(e => e.ToGate()))
{
gate = Gate.ComposeOR(gate, term, ComposeOptions.NoSimplify);
}
break;
}
if (gate != originalgate)
{
Gate.TraceSimplify(originalgate, gate, "simplify OR (2)");
}
return gate != originalgate;
}
public static IGate ExtractCommonFactors(IGate gate)
{
var original = gate;
if (gate.Type == GateType.OR)
{
// TraceOptimize("extract common factors from {0} ...", gate);
var sop = gate.GetSOP();
// count how many times each factor appears
var inmap = new Dictionary <int, IInput>();
var dict = new SortedList <int, int>();
foreach (var p in sop.GetPrimitiveFactors())
{
// a gate representing the factors (may be multiple per state variable)
var pg = p.ToGate();
foreach (var i in pg.GetInputs().OfType <IInput>())
{
var address = i.Address;
// TraceOptimize("check factor {0} @ {1:X6}", i, address);
if (!inmap.ContainsKey(i.Address))
{
inmap.Add(i.Address, i);
}
if (!dict.ContainsKey(address))
{
dict[address] = 1;
}
else
{
dict[address]++;
}
}
}
var m = dict.Values.Max();
// TraceOptimize("maximum factor count {0}", m);
if (m > 1)
{
// go for it, take the first input with maximum multiplicity, inputs are ordered.
var pivotindex = dict.Where(e => e.Value == m).Select(e => e.Key).First();
var pivot = inmap[pivotindex];
var pivotlist = new List <Product>();
var otherlist = new List <Product>();
TraceOptimize("use pivot {0:X6} ...", pivot);
// split sop into two groups: factor or not
foreach (var p in sop)
{
if (p.ContainsFactor(pivot))
{
p.RemoveInput(pivot);
pivotlist.Add(p);
}
else
{
otherlist.Add(p);
}
}
IGate and = new ANDGate();
and.AddInput(pivot);
IGate inneror = new ORGate();
foreach (var p in pivotlist)
{
var z = p.ToGate().Simplify();
// Debug.Assert(z.GetInputs().Count() > 1);
Trace("adding pivot {0} [{1}]", z, z.GetType().Name);
inneror.AddInput(z);
}
inneror = ExtractCommonFactors(inneror);
and.AddInput(inneror);
if (otherlist.Any())
{
//var rh = ExtractCommonFactors(otherlist);
var or = new ORGate();
or.AddInput(and);
foreach (var p in otherlist)
{
var z = p.ToGate();
or.AddInput(z.Simplify());
}
gate = or;
}
else
{
gate = and;
}
}
}
if (gate != original && TraceFlags.ShowOptimize)
{
Log.TraceGateOp2(original, gate, "optimize AND");
}
return(gate);
}
/// <summary>
/// Looks for common subfactors.
/// </summary>
/// <param name="gate"></param>
private bool SimplifyRule2(ref IGate gate)
{
var originalgate = gate;
var gset = gate.GetSOP();
// try all elementary factors ...
foreach (var elementaryfactor in gset.GetPrimitiveFactors().ToArray())
{
// Trace("trying factor {0}", elementaryfactor);
// collect all products that contain the factor as candidates
var candidates = new List <Product>();
foreach (var p in gset)
{
if (1 == p.ContainsFactor(elementaryfactor))
{
candidates.Add(p);
}
}
// need at least two
if (candidates.Count < 2)
{
continue;
}
TraceSimplify("common factor {0} found in {1} ...", elementaryfactor, candidates.ToSeparatorList());
// construct a new gate consisting of the sum of remaining products
var reducedsum = new ORGate();
Gate newgate = reducedsum;
foreach (var involvedproduct in candidates)
{
var reducedproduct = involvedproduct.Clone();
reducedproduct.Remove(elementaryfactor);
if (reducedproduct.Factors.Any())
{
reducedsum.AddInput(reducedproduct.ToGate());
}
else
{
// candidate equals elementary factor => TRUE
newgate = new TrueGate();
break;
}
}
// remove original elements from the set
foreach (var x in candidates)
{
gset.Remove(x);
}
// simplify the resulting gate recursively
var partialsum = newgate.Simplify();
var factor = elementaryfactor.ToGate();
TraceSimplify(" is ({0}) AND {1}", partialsum, factor);
if (partialsum.Type == GateType.Fixed)
{
if (partialsum is TrueGate)
{
// factor only
gate = factor;
}
else
{
// simplification yields FALSE
gate = partialsum;
}
}
else if (partialsum.Type == GateType.AND)
{
// multiply with factor
gate = Gate.Multiply(factor.GetInputs(), partialsum);
}
else if (partialsum.Type == GateType.OR)
{
// multiply with all factors
gate = Gate.Multiply(factor.GetInputs(), partialsum.GetInputs());
}
else
{
// multiply with factor
gate = Gate.Multiply(factor.GetInputs(), partialsum);
}
// compose with the remaining terms
foreach (var term in gset.Select(e => e.ToGate()))
{
gate = Gate.ComposeOR(gate, term, ComposeOptions.NoSimplify);
}
break;
}
if (gate != originalgate)
{
Gate.TraceSimplify(originalgate, gate, "simplify OR (2)");
}
return(gate != originalgate);
}
