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 bool Equals(VariableOffset other)
{
foreach (var kvp in other.offsets)
{
if (offsets.TryGetValue(kvp.Key, out var value))
{
if (value != kvp.Value)
{
return(false);
}
}
else
{
return(false);
}
}
return(true);
}
public void UnionWith(VariableOffset other, int offset = 0)
{
foreach (var kvp in other.offsets)
{
if (kvp.Value == -1)
{
offsets[kvp.Key] = -1;
}
else if (offsets.TryGetValue(kvp.Key, out var value))
{
if (value == -1 || value != kvp.Value + offset)
{
offsets[kvp.Key] = -1;
}
}
else
{
offsets[kvp.Key] = kvp.Value + offset;
}
}
}