public static LivenessValue[] CalcLiveness(List <ILInstruction> code, ILVariable variable, int[][] succ, int[][] pres)
{
var use = code.Select(x => usesSingle(x, variable)).ToArray();
var def = code.Select(x => defs(x, variable)).ToArray();
var pointers = TypeInference.GetPointers(variable);
foreach (var pointer in pointers)
{
var pointerUse = code.Select(x => usesSingle(x, pointer)).ToArray();
use = use.Zip(pointerUse, (a, b) => a || b).ToArray();
}
var liveIn = new bool[code.Count];
var liveOut = new bool[code.Count];
var liveInOld = new bool[code.Count];
var liveOutOld = new bool[code.Count];
do
{
for (int i = 0; i < code.Count; i++)
{
liveInOld[i] = liveIn[i];
liveOutOld[i] = liveOut[i];
liveIn[i] = use[i] || (liveOut[i] && !def[i]);
//if(pres[i].Count() > 1)
{ // special case for branches, where live comes out only one branch
var preLiveOut = pres[i].Any(x => liveOut[x]);
liveIn[i] |= preLiveOut;
}
liveOut[i] = succ[i].Any(x => liveIn[x]);
}
} while (!liveInOld.SequenceEqual(liveIn) || !liveOutOld.SequenceEqual(liveOut));
// The return value is still alive when leaving the function.
if (code.Last() is Leave leave && leave.IsLeavingFunction)
{
leave.Value.MatchLdLoc(out var retVar);
if (retVar == variable)
{
liveOut[code.Count - 1] = true;
}
}
var res = liveIn.Zip(liveOut, (a, b) => new LivenessValue {
LiveIn = a, LiveOut = b
}).ToArray();
return(res); //new Tuple<bool[], bool[]>(liveIn, liveOut);
}
