public static void SolveSimpleValueRegs(SchemeFunction function)
{
//We iterate commands
//If we find a SET(<reg>, <simple value>) command, we
// //remove this SET command
// //Iterate over the subsequent commands in the base block
// //If we find any command with input <reg> we change it to <simple value>
// //If we find any command with output <reg> we stop and goto 1. (continuing from the SET command we found)
var commands = function.Commands;
HashSet <int> removableIndexes = new HashSet <int>();
for (int i = 0; i < commands.Count; ++i)
{
ISchemeCommand cmd = commands[i];
if (cmd is CommandSetVariable)
{
CommandSetVariable cmdSet = (CommandSetVariable)cmd;
string targetVar = cmdSet.GetVariableName();
string value = cmdSet.GetValue();
if (SchemeExecutor.IsRegister(targetVar))
{
removableIndexes.Add(i);
for (int i2 = i + 1; i2 < commands.Count; ++i2)
{
ISchemeCommand cmd2 = commands[i2];
cmd2.ChangeInputs(targetVar, value);
if (cmd2 is CommandJumpBase || cmd2.HasOutput(targetVar))
{
break;
}
}
}
}
}
RemoveCommandsAt(function, removableIndexes);
}
public static void SolveRegisterBuffers(SchemeFunction function)
{
// if an operation stores its result in a register <reg>, and it is followed by a SET(<var>, <reg>) command
// we delete the SET command and set the opperation's output to <var>
// we iterate over the following commands and change any <reg> to <var>
// we stop if <reg> is set again or we leave the block
var commands = function.Commands;
HashSet <int> removableIndexes = new HashSet <int>();
for (int i = 0; i < commands.Count; ++i)
{
ISchemeCommand cmd = commands[i];
var outputs = cmd.GetOutputs();
if (outputs == null)
{
continue;
}
// check if any output is a register
foreach (var reg in outputs)
{
if (SchemeExecutor.IsRegister(reg))
{
string variable = null;
for (int j = i + 1; j < commands.Count; ++j)
{
ISchemeCommand cmd2 = commands[j];
if (cmd2 is CommandJumpBase)
{
break; // break if we leave the block
}
if (cmd2.HasOutput(reg))
{
break; // break if the register is set again
}
if (cmd2 is CommandSetVariable && cmd2.HasInput(reg))
{
CommandSetVariable setCmd = (CommandSetVariable)cmd2;
variable = setCmd.GetVariableName();
if (SchemeExecutor.IsRegister(variable))
{
variable = null;
}
else
{
cmd.ChangeOutput(reg, variable);
removableIndexes.Add(j);
}
}
if (variable != null && cmd2.HasInput(reg))
{
cmd2.ChangeInputs(reg, variable);
}
}
}
}
}
RemoveCommandsAt(function, removableIndexes);
}
