/// <summary>
/// Applies the LICM transformation to the given loop.
/// </summary>
/// <param name="builder">The parent method builder.</param>
/// <param name="loop">The current loop.</param>
/// <returns>True, if the transformation could be applied.</returns>
private static bool ApplyLICM(Method.Builder builder, Loop loop)
{
// Initialize the current loop invariance cache
var invariance = new LoopInvariance(loop);
// Ensure that all blocks are in the correct order
BasicBlockCollection <ReversePostOrder, Forwards> blocks =
loop.ComputeOrderedBlocks(0);
// Get the initial entry builder to move all values to
var entry = loop.Entries[0];
var mover = new Mover(blocks.Count);
// Traverse all blocks in reverse post order to move all values without
// violating any SSA properties
foreach (var block in blocks)
{
if (block == entry)
{
continue;
}
foreach (Value value in block)
{
// Move out of the loop if this value is loop invariant
if (invariance.IsLoopInvariant(value))
{
mover.Add(value);
}
}
}
// Move values
var entryBuilder = builder[entry];
foreach (var valueToMove in mover.ToMove)
{
// Check whether this value should be moved out of the current loop
if (mover.ShouldBeMoved(valueToMove))
{
entryBuilder.AddFromOtherBlock(valueToMove);
}
}
return(mover.ToMove.Length > 0);
}
/// <summary>
/// Applies the control-flow simplification transformation.
/// </summary>
protected override bool PerformTransformation(Method.Builder builder)
{
// We change the control-flow structure during the transformation but
// need to get information about previous predecessors and successors
builder.AcceptControlFlowUpdates(accept: true);
BasicBlockCollection <ReversePostOrder, Forwards> blocks =
builder.SourceBlocks;
var visited = blocks.CreateSet();
bool result = false;
foreach (var block in blocks)
{
result |= MergeChain(builder, block, ref visited);
}
return(result);
}
/// <summary>
/// Creates a new default block schedule using the given blocks.
/// </summary>
/// <param name="blocks">The input blocks.</param>
/// <returns>The created block schedule.</returns>
public static PTXBlockSchedule CreateDefaultPTXSchedule(
this BasicBlockCollection <ReversePostOrder, Forwards> blocks) =>
new DefaultPTXBlockSchedule(blocks);
/// <summary>
/// Creates a schedule from an already existing schedule.
/// </summary>
/// <typeparam name="TOrder">The current order.</typeparam>
/// <typeparam name="TDirection">The control-flow direction.</typeparam>
/// <param name="blocks">The input blocks.</param>
/// <returns>The created block schedule.</returns>
public static PTXBlockSchedule CreateOptimizedPTXSchedule <TOrder, TDirection>(
this BasicBlockCollection <TOrder, TDirection> blocks)
where TOrder : struct, ITraversalOrder
where TDirection : struct, IControlFlowDirection =>
CreateSchedule(
/// <summary>
/// Creates a new optimized block schedule using the given blocks.
/// </summary>
/// <typeparam name="TOrder">The current order.</typeparam>
/// <typeparam name="TDirection">The control-flow direction.</typeparam>
/// <param name="blocks">The input blocks.</param>
/// <returns>The created block schedule.</returns>
public static PTXBlockSchedule CreatePTXScheduleToOptimize <TOrder, TDirection>(
this BasicBlockCollection <TOrder, TDirection> blocks)
where TOrder : struct, ITraversalOrder
where TDirection : struct, IControlFlowDirection =>
CreateSchedule(blocks.ChangeOrder <PreOrder, Forwards>());
public ControlFlowGraph(BasicBlockCollection collection)
{
this.blocks = collection;
}
