public static (Block[] Graph, Block Root) DecodeSubroutine(
TranslatorCache cache,
CpuThreadState state,
MemoryManager memory,
long start)
{
Dictionary <long, Block> visited = new Dictionary <long, Block>();
Dictionary <long, Block> visitedEnd = new Dictionary <long, Block>();
Queue <Block> blocks = new Queue <Block>();
Block Enqueue(long position)
{
if (!visited.TryGetValue(position, out Block output))
{
output = new Block(position);
blocks.Enqueue(output);
visited.Add(position, output);
}
return(output);
}
Block root = Enqueue(start);
while (blocks.Count > 0)
{
Block current = blocks.Dequeue();
FillBlock(state, memory, current);
//Set child blocks. "Branch" is the block the branch instruction
//points to (when taken), "Next" is the block at the next address,
//executed when the branch is not taken. For Unconditional Branches
//(except BL/BLR that are sub calls) or end of executable, Next is null.
if (current.OpCodes.Count > 0)
{
bool hasCachedSub = false;
OpCode64 lastOp = current.GetLastOp();
if (lastOp is OpCodeBImm64 op)
{
if (op.Emitter == InstEmit.Bl)
{
hasCachedSub = cache.HasSubroutine(op.Imm);
}
else
{
current.Branch = Enqueue(op.Imm);
}
}
if (!((lastOp is OpCodeBImmAl64) ||
(lastOp is OpCodeBReg64)) || hasCachedSub)
{
current.Next = Enqueue(current.EndPosition);
}
}
//If we have on the graph two blocks with the same end position,
//then we need to split the bigger block and have two small blocks,
//the end position of the bigger "Current" block should then be == to
//the position of the "Smaller" block.
while (visitedEnd.TryGetValue(current.EndPosition, out Block smaller))
{
if (current.Position > smaller.Position)
{
Block temp = smaller;
smaller = current;
current = temp;
}
current.EndPosition = smaller.Position;
current.Next = smaller;
current.Branch = null;
current.OpCodes.RemoveRange(
current.OpCodes.Count - smaller.OpCodes.Count,
smaller.OpCodes.Count);
visitedEnd[smaller.EndPosition] = smaller;
}
visitedEnd.Add(current.EndPosition, current);
}
//Make and sort Graph blocks array by position.
Block[] graph = new Block[visited.Count];
while (visited.Count > 0)
{
ulong firstPos = ulong.MaxValue;
foreach (Block block in visited.Values)
{
if (firstPos > (ulong)block.Position)
{
firstPos = (ulong)block.Position;
}
}
Block current = visited[(long)firstPos];
do
{
graph[graph.Length - visited.Count] = current;
visited.Remove(current.Position);
current = current.Next;
}while (current != null);
}
return(graph, root);
}
public static Block DecodeSubroutine(
TranslatorCache cache,
MemoryManager memory,
long start,
ExecutionMode mode)
{
Dictionary <long, Block> visited = new Dictionary <long, Block>();
Dictionary <long, Block> visitedEnd = new Dictionary <long, Block>();
Queue <Block> blocks = new Queue <Block>();
Block Enqueue(long position)
{
if (!visited.TryGetValue(position, out Block output))
{
output = new Block(position);
blocks.Enqueue(output);
visited.Add(position, output);
}
return(output);
}
Block entry = Enqueue(start);
while (blocks.Count > 0)
{
Block current = blocks.Dequeue();
FillBlock(memory, mode, current);
//Set child blocks. "Branch" is the block the branch instruction
//points to (when taken), "Next" is the block at the next address,
//executed when the branch is not taken. For Unconditional Branches
//(except BL/BLR that are sub calls) or end of executable, Next is null.
if (current.OpCodes.Count > 0)
{
bool hasCachedSub = false;
OpCode64 lastOp = current.GetLastOp();
if (lastOp is IOpCodeBImm op)
{
if (op.Emitter == InstEmit.Bl)
{
hasCachedSub = cache.HasSubroutine(op.Imm);
}
else
{
current.Branch = Enqueue(op.Imm);
}
}
if (!IsUnconditionalBranch(lastOp) || hasCachedSub)
{
current.Next = Enqueue(current.EndPosition);
}
}
//If we have on the graph two blocks with the same end position,
//then we need to split the bigger block and have two small blocks,
//the end position of the bigger "Current" block should then be == to
//the position of the "Smaller" block.
while (visitedEnd.TryGetValue(current.EndPosition, out Block smaller))
{
if (current.Position > smaller.Position)
{
Block temp = smaller;
smaller = current;
current = temp;
}
current.EndPosition = smaller.Position;
current.Next = smaller;
current.Branch = null;
current.OpCodes.RemoveRange(
current.OpCodes.Count - smaller.OpCodes.Count,
smaller.OpCodes.Count);
visitedEnd[smaller.EndPosition] = smaller;
}
visitedEnd.Add(current.EndPosition, current);
}
return(entry);
}