/// <summary cref="IBackendCodeGenerator.GenerateCode(ReturnTerminator)"/>
public void GenerateCode(ReturnTerminator returnTerminator)
{
if (!returnTerminator.IsVoidReturn)
{
var resultRegister = Load(returnTerminator.ReturnValue);
EmitStoreParam(ReturnParamName, resultRegister);
}
Command(
Uniforms.IsUniform(returnTerminator)
? PTXInstructions.UniformReturnOperation
: PTXInstructions.ReturnOperation);
}
/// <summary cref="IBackendCodeGenerator.GenerateCode(IfBranch)"/>
public void GenerateCode(IfBranch branch)
{
var primitiveCondition = LoadPrimitive(branch.Condition);
var condition = EnsureHardwareRegister(primitiveCondition);
// Use the actual branch targets from the schedule
var(trueTarget, falseTarget) = branch.NotInvertedBranchTargets;
// Determine the branch operation to be used
var branchOperation = Uniforms.IsUniform(branch)
? PTXInstructions.UniformBranchOperation
: PTXInstructions.BranchOperation;
// The current schedule has inverted all if conditions with implicit branch
// targets to simplify the work of the PTX assembler
if (Schedule.IsImplicitSuccessor(branch.BasicBlock, trueTarget))
{
// Jump to false target in the else case
using var command = BeginCommand(
branchOperation,
new PredicateConfiguration(
condition,
isTrue: branch.IsInverted));
var targetLabel = blockLookup[falseTarget];
command.AppendLabel(targetLabel);
}
else
{
if (branch.IsInverted)
{
Utilities.Swap(ref trueTarget, ref falseTarget);
}
using (var command = BeginCommand(
branchOperation,
new PredicateConfiguration(condition, isTrue: true)))
{
var targetLabel = blockLookup[trueTarget];
command.AppendLabel(targetLabel);
}
// Jump to false target in the else case
using (var command = BeginCommand(PTXInstructions.UniformBranchOperation))
{
var targetLabel = blockLookup[falseTarget];
command.AppendLabel(targetLabel);
}
}
}
/// <summary cref="IBackendCodeGenerator.GenerateCode(UnconditionalBranch)"/>
public void GenerateCode(UnconditionalBranch branch)
{
if (Schedule.IsImplicitSuccessor(branch.BasicBlock, branch.Target))
{
return;
}
// Determine the branch operation to be used
var branchOperation = Uniforms.IsUniform(branch)
? PTXInstructions.UniformBranchOperation
: PTXInstructions.BranchOperation;
using var command = BeginCommand(branchOperation);
var targetLabel = blockLookup[branch.Target];
command.AppendLabel(targetLabel);
}
/// <summary cref="IBackendCodeGenerator.GenerateCode(SwitchBranch)"/>
public void GenerateCode(SwitchBranch branch)
{
bool isUniform = Uniforms.IsUniform(branch);
var idx = LoadPrimitive(branch.Condition);
using (var lowerBoundsScope = new PredicateScope(this))
{
// Emit less than
var lessThanCommand = PTXInstructions.GetCompareOperation(
CompareKind.LessThan,
CompareFlags.None,
ArithmeticBasicValueType.Int32);
using (var command = BeginCommand(
lessThanCommand))
{
command.AppendArgument(lowerBoundsScope.PredicateRegister);
command.AppendArgument(idx);
command.AppendConstant(0);
}
using var upperBoundsScope = new PredicateScope(this);
using (var command = BeginCommand(
PTXInstructions.BranchIndexRangeComparison))
{
command.AppendArgument(upperBoundsScope.PredicateRegister);
command.AppendArgument(idx);
command.AppendConstant(branch.NumCasesWithoutDefault);
command.AppendArgument(lowerBoundsScope.PredicateRegister);
}
using (var command = BeginCommand(
isUniform
? PTXInstructions.UniformBranchOperation
: PTXInstructions.BranchOperation,
new PredicateConfiguration(
upperBoundsScope.PredicateRegister,
true)))
{
var defaultTarget = blockLookup[branch.DefaultBlock];
command.AppendLabel(defaultTarget);
}
}
var targetLabel = DeclareLabel();
MarkLabel(targetLabel);
Builder.Append('\t');
Builder.Append(PTXInstructions.BranchTargetsDeclaration);
Builder.Append(' ');
for (int i = 0, e = branch.NumCasesWithoutDefault; i < e; ++i)
{
var caseTarget = branch.GetCaseTarget(i);
var caseLabel = blockLookup[caseTarget];
Builder.Append(caseLabel);
if (i + 1 < e)
{
Builder.Append(", ");
}
}
Builder.AppendLine(";");
using (var command = BeginCommand(
isUniform
? PTXInstructions.UniformBranchIndexOperation
: PTXInstructions.BranchIndexOperation))
{
command.AppendArgument(idx);
command.AppendLabel(targetLabel);
}
}