private static bool TryReplaceUsesInFlow(
BlockFlow flow,
IReadOnlyDictionary <ValueTag, ValueTag> replacementMap,
out BlockFlow newFlow)
{
bool replacedAny = false;
var instructions = flow.Instructions;
var newInstructions = new Instruction[instructions.Count];
for (int i = 0; i < newInstructions.Length; i++)
{
Instruction newInsn;
if (TryReplaceUsesInInstruction(instructions[i], replacementMap, out newInsn))
{
newInstructions[i] = newInsn;
replacedAny = true;
}
else
{
newInstructions[i] = instructions[i];
}
}
var branches = flow.Branches;
var newBranches = new Branch[branches.Count];
for (int i = 0; i < newBranches.Length; i++)
{
var branch = branches[i];
var newArgs = new BranchArgument[branch.Arguments.Count];
for (int j = 0; j < newArgs.Length; j++)
{
var arg = branch.Arguments[j];
ValueTag value;
if (arg.IsValue &&
replacementMap.TryGetValue(arg.ValueOrNull, out value) &&
value != arg.ValueOrNull)
{
newArgs[j] = BranchArgument.FromValue(value);
replacedAny = true;
}
else
{
newArgs[j] = arg;
}
}
newBranches[i] = branch.WithArguments(newArgs);
}
if (replacedAny)
{
newFlow = flow.WithBranches(newBranches).WithInstructions(newInstructions);
}
else
{
newFlow = flow;
}
return(replacedAny);
}
/// <summary>
/// Creates a new branch by applying a mapping to every value in
/// this branch's argument list.
/// </summary>
/// <param name="mapping">
/// The mapping to apply to every value in this branch's
/// argument list.
/// </param>
/// <returns>A new branch.</returns>
public Branch MapArguments(Func <ValueTag, ValueTag> mapping)
{
return(MapArguments(
arg =>
arg.IsValue
? BranchArgument.FromValue(mapping(arg.ValueOrNull))
: arg));
}
/// <summary>
/// Creates a branch that is the result of appending
/// an argument at the end of this branch's argument list.
/// </summary>
/// <param name="argument">The argument to add.</param>
/// <returns>A new branch.</returns>
public Branch AddArgument(BranchArgument argument)
{
var oldArgCount = Arguments.Count;
var newArgs = new BranchArgument[oldArgCount + 1];
for (int i = 0; i < oldArgCount; i++)
{
newArgs[i] = Arguments[i];
}
newArgs[oldArgCount] = argument;
return(WithArguments(newArgs));
}
/// <summary>
/// Creates a branch that is the result of appending
/// an argument at the end of this branch's argument list.
/// </summary>
/// <param name="argument">The argument to add.</param>
/// <returns>A new branch.</returns>
public Branch AddArgument(ValueTag argument)
{
return(AddArgument(BranchArgument.FromValue(argument)));
}