protected override bool InnerOptimize(OptimizationContext context, Instruction matchedInstruction, Backtracer backtracer, int i)
{
var changed = false;
var j = i;
var patchedLabels = new Dictionary <(ushort label, short offset), ushort>();
var offset = matchedInstruction.Offset;
var removedAt = 0;
context.RemoveAt(j);
while (!IsChainBreaker(context[j], Instruction.Advance(offset), null))
{
var instruction = context[j];
switch (instruction.Type)
{
case InstructionType.Advance:
offset += instruction.Offset;
removedAt = j;
context.RemoveAt(j);
break;
case InstructionType.BoundsCheck:
case InstructionType.Char:
var targetLabel = instruction.Label;
if (context[context.GetLabelPosition(targetLabel) + 1].Type != InstructionType.RestorePosition)
{
if (patchedLabels.TryGetValue((targetLabel, offset), out var newTarget))
{
targetLabel = newTarget;
}
else if (offset != 0)
{
var oldLabel = targetLabel;
targetLabel = AddStub(context, targetLabel, Instruction.Advance(offset), ref j);
patchedLabels[(oldLabel, offset)] = targetLabel;
public override bool Optimize(OptimizationContext context)
{
var changed = false;
var offsetInfo = new VariableOffset[context.Count];
for (var i = 0; i < offsetInfo.Length; i++)
{
offsetInfo[i] = new VariableOffset();
}
BuildOffsetInfo(context, offsetInfo);
for (var i = context.Count - 1; i >= 0; i--)
{
var instruction = context[i];
switch (instruction.Type)
{
case InstructionType.RestorePosition:
var offset = offsetInfo[i].Get(instruction.Data1);
if (offset == 0)
{
changed = true;
context.RemoveAt(i);
}
else if (offset > 0)
{
changed = true;
context[i] = Instruction.Advance((short)-offset);
}
break;
}
}
return(changed);
}
public void SimplePrecompiled()
{
var p = new PrecompiledPattern(new Method("Precompiled", new List <Instruction>()
{
Instruction.Char(0, 0, 0, 1),
Instruction.Char(0, 1, 1, 2),
Instruction.Advance(2),
Instruction.Return(0),
Instruction.MarkLabel(0),
Instruction.Return(1),
}, new List <CharRange>()
{
new CharRange('a', 'a'),
new CharRange('b', 'b'),
}, new List <LabelMap>(), 0, 1), new List <Pattern>());
MustMatch(p, "ab");
MustNotMatch(p, "bb");
MustNotMatch(p, "ac");
}
public override bool Optimize(OptimizationContext context)
{
var changed = false;
for (var i = context.Count - 1; i >= 0; i--)
{
var instructionType = context[i].Type;
if (instructionType == InstructionType.Advance)
{
if (context[i].Offset == 0 || !IsNeeded(context, i))
{
changed = true;
context.RemoveAt(i);
}
}
}
for (var i = 0; i < context.Count; i++)
{
if (context[i].Type == InstructionType.Advance && context[i + 1].Matches(InstructionType.Jump, out var jumpTargetLabel))
{
var jumpTarget = context.GetLabelPosition(jumpTargetLabel) + 1;
if (context[jumpTarget].Type == InstructionType.Advance)
{
changed = true;
var newLabel = context.LabelAllocator++;
context[i] = Instruction.Advance((short)(context[i].Offset + context[jumpTarget].Offset));
context[i + 1] = Instruction.Jump(newLabel);
context.Insert(jumpTarget + 1, Instruction.MarkLabel(newLabel));
}
}
}
return(changed);
}
