private object EvaluateVariable(Variable v)
{
if (!_ivStack.Contains(v))
{
throw new BreakEvaluationException();
}
IVRange range = _iva._ivLoopRange[v];
return(range);
}
/// <summary>
/// Retrieves the value range constraint for a specific variable.
/// </summary>
/// <param name="v">variable to query</param>
/// <param name="minValue">minimum value</param>
/// <param name="maxValue">maximum value</param>
/// <exception cref="ArgumentException">if no value range constraint exists for the specified variable</exception>
public void GetRange(Variable v, out long minValue, out long maxValue)
{
if (!IsConstrained(v))
{
throw new ArgumentException("no value range constraint found", "v");
}
IVRange range = _ivLoopRange[v];
minValue = range.MinValue;
maxValue = range.MaxValue;
}
public void AcceptLoopBlock(LoopBlock stmt)
{
if (stmt.Initializer != null &&
stmt.CounterStart != null &&
stmt.CounterStop != null &&
stmt.CounterStep != null)
{
if (/*stmt.CounterStart.IsConst(_ecr) &&
* stmt.CounterStop.IsConst(_ecr) &&*/
stmt.CounterStep.IsConst(_ecr))
{
try
{
Expression minExpr, maxExpr;
switch (stmt.CounterDirection)
{
case LoopBlock.ECounterDirection.Increment:
minExpr = stmt.CounterStart;
maxExpr = stmt.CounterStop + stmt.CounterStep;
if (stmt.CounterLimitKind == LoopBlock.ELimitKind.ExcludingStopValue)
{
maxExpr -= LiteralReference.CreateConstant((long)1);
}
break;
case LoopBlock.ECounterDirection.Decrement:
maxExpr = stmt.CounterStart;
minExpr = stmt.CounterStop - stmt.CounterStep;
if (stmt.CounterLimitKind == LoopBlock.ELimitKind.ExcludingStopValue)
{
minExpr += LiteralReference.CreateConstant((long)1);
}
break;
default:
throw new NotImplementedException();
}
object min = minExpr.Eval(_eval);
object max = maxExpr.Eval(_eval);
IVRange minR = IVRange.ToRange(min);
IVRange maxR = IVRange.ToRange(max);
IVRange loopRange = IVRange.Max(minR, maxR);
if (_iva._ivLoopRange.ContainsKey(stmt.CounterVariable))
{
_iva._ivLoopRange[stmt.CounterVariable] =
IVRange.Max(_iva._ivLoopRange[stmt.CounterVariable], loopRange);
}
else
{
_iva._ivLoopRange[stmt.CounterVariable] = loopRange;
}
_iva._inductionVars.Add(stmt.CounterVariable, stmt);
_ivStack.Push(stmt.CounterVariable);
stmt.Body.Accept(this);
if (stmt.Trailer != null)
{
stmt.Trailer.Accept(this);
}
_ivStack.Pop();
return;
}
catch (BreakEvaluationException)
{
}
catch (InvalidCastException)
{
}
catch (InvalidOperationException)
{
}
}
_iva._unconstrainedVars.Add(stmt.CounterVariable);
}
stmt.Body.Accept(this);
if (stmt.Trailer != null)
{
stmt.Trailer.Accept(this);
}
}
public static IVRange Max(IVRange r1, IVRange r2)
{
return(new IVRange(
Math.Min(r1.MinValue, r2.MinValue),
Math.Max(r1.MaxValue, r2.MaxValue)));
}
