private void VisitLoopAfterRightBorderNodes(Compiler.Nodes.Loop loop)
{
LoopData loopData = _loopData[loop];
_builder.CreateBr(loopData.StartBlock);
_builder.PositionBuilderAtEnd(loopData.EndBlock);
}
private void VisitLoopAfterRightBorderNodes(Compiler.Nodes.Loop loop)
{
LoopData loopData = _loopData[loop];
_builder.EmitBranch(loopData.Start);
_builder.SetLabel(loopData.End);
}
private void VisitLoopBeforeLeftBorderNodes(Compiler.Nodes.Loop loop)
{
LLVMBasicBlockRef startBlock = _topLevelFunction.AppendBasicBlock($"loop{loop.UniqueId}_start"),
interiorBlock = _topLevelFunction.AppendBasicBlock($"loop{loop.UniqueId}_interior"),
endBlock = _topLevelFunction.AppendBasicBlock($"loop{loop.UniqueId}_end");
LoopConditionTunnel loopCondition = loop.BorderNodes.OfType <LoopConditionTunnel>().First();
Terminal loopConditionInput = loopCondition.InputTerminals[0];
var conditionAllocationSource = (LocalAllocationValueSource)GetTerminalValueSource(loopConditionInput);
_loopData[loop] = new LoopData(conditionAllocationSource, startBlock, interiorBlock, endBlock);
if (!loopConditionInput.IsConnected)
{
// if loop condition was unwired, initialize it to true
conditionAllocationSource.UpdateValue(_builder, true.AsLLVMValue());
}
// initialize all output tunnels with None values, in case the loop interior does not execute
foreach (Tunnel outputTunnel in loop.BorderNodes.OfType <Tunnel>().Where(tunnel => tunnel.Direction == Direction.Output))
{
VariableReference tunnelOutputVariable = outputTunnel.OutputTerminals[0].GetTrueVariable();
ValueSource tunnelOutputSource = _variableValues[tunnelOutputVariable];
LLVMTypeRef tunnelOutputType = tunnelOutputVariable.Type.AsLLVMType();
tunnelOutputSource.UpdateValue(_builder, LLVMSharp.LLVM.ConstNull(tunnelOutputType));
}
_builder.CreateBr(startBlock);
_builder.PositionBuilderAtEnd(startBlock);
}
private void VisitLoopAfterLeftBorderNodes(Compiler.Nodes.Loop loop)
{
LoopData loopData = _loopData[loop];
LoadLocalAllocationReference(loopData.LoopCondition);
_builder.EmitDerefInteger();
_builder.EmitBranchIfFalse(loopData.End);
}
private void VisitLoopAfterLeftBorderNodes(Compiler.Nodes.Loop loop)
{
LoopData loopData = _loopData[loop];
LLVMValueRef condition = loopData.ConditionAllocationSource.GetValue(_builder);
_builder.CreateCondBr(condition, loopData.InteriorBlock, loopData.EndBlock);
_builder.PositionBuilderAtEnd(loopData.InteriorBlock);
}
private void VisitLoopBeforeLeftBorderNodes(Compiler.Nodes.Loop loop)
{
LabelBuilder start = _builder.CreateLabel(),
end = _builder.CreateLabel();
LoopConditionTunnel loopCondition = loop.BorderNodes.OfType <LoopConditionTunnel>().First();
Terminal loopConditionInput = loopCondition.InputTerminals.ElementAt(0);
VariableReference loopConditionVariable = loopConditionInput.GetTrueVariable();
_loopData[loop] = new LoopData(start, end, loopConditionVariable);
if (!loopConditionInput.IsConnected)
{
// if loop condition was unwired, initialize it to true
LoadLocalAllocationReference(loopConditionVariable);
_builder.EmitLoadIntegerImmediate(1);
_builder.EmitStoreInteger();
}
_builder.SetLabel(start);
}
public bool VisitLoop(Compiler.Nodes.Loop loop, StructureTraversalPoint traversalPoint)
{
// generate code for each left-side border node;
// each border node that can affect condition should &&= the LoopCondition
// variable with whether it allows loop to proceed
switch (traversalPoint)
{
case StructureTraversalPoint.BeforeLeftBorderNodes:
VisitLoopBeforeLeftBorderNodes(loop);
break;
case StructureTraversalPoint.AfterLeftBorderNodesAndBeforeDiagram:
VisitLoopAfterLeftBorderNodes(loop);
break;
case StructureTraversalPoint.AfterRightBorderNodes:
VisitLoopAfterRightBorderNodes(loop);
break;
}
return(true);
}
