// May not return all args. The args are returned in reverse order.
static PushedArgs GetPushedArgInstructions(IList<Instruction> instructions, int index, int numArgs) {
var pushedArgs = new PushedArgs(numArgs);
Instruction instr;
int skipPushes = 0;
while (index >= 0 && pushedArgs.CanAddMore) {
instr = GetPreviousInstruction(instructions, ref index);
if (instr == null)
break;
int pushes, pops;
instr.CalculateStackUsage(false, out pushes, out pops);
if (pops == -1)
break;
if (instr.OpCode.Code == Code.Dup) {
pushes = 1;
pops = 0;
}
if (pushes > 1)
break;
if (skipPushes > 0) {
skipPushes -= pushes;
if (skipPushes < 0)
break;
skipPushes += pops;
}
else {
if (pushes == 1)
pushedArgs.Add(instr);
skipPushes += pops;
}
}
instr = pushedArgs.Get(0);
if (instr != null && instr.OpCode.Code == Code.Dup) {
instr = GetPreviousInstruction(instructions, ref index);
if (instr != null) {
int pushes, pops;
instr.CalculateStackUsage(false, out pushes, out pops);
if (pushes == 1 && pops == 0)
pushedArgs.Set(0, instr);
}
}
pushedArgs.FixDups();
return pushedArgs;
}
// May not return all args. The args are returned in reverse order.
static PushedArgs GetPushedArgInstructions(IList <Instruction> instructions, int index, int numArgs)
{
var pushedArgs = new PushedArgs(numArgs);
Instruction instr;
int skipPushes = 0;
while (index >= 0 && pushedArgs.CanAddMore)
{
instr = GetPreviousInstruction(instructions, ref index);
if (instr == null)
{
break;
}
instr.CalculateStackUsage(false, out int pushes, out int pops);
if (pops == -1)
{
break;
}
if (instr.OpCode.Code == Code.Dup)
{
pushes = 1;
pops = 0;
}
if (pushes > 1)
{
break;
}
if (skipPushes > 0)
{
skipPushes -= pushes;
if (skipPushes < 0)
{
break;
}
skipPushes += pops;
}
else
{
if (pushes == 1)
{
pushedArgs.Add(instr);
}
skipPushes += pops;
}
}
instr = pushedArgs.Get(0);
if (instr != null && instr.OpCode.Code == Code.Dup)
{
instr = GetPreviousInstruction(instructions, ref index);
if (instr != null)
{
instr.CalculateStackUsage(false, out int pushes, out int pops);
if (pushes == 1 && pops == 0)
{
pushedArgs.Set(0, instr);
}
}
}
pushedArgs.FixDups();
return(pushedArgs);
}
private static Update UpdateState(IList <Instruction> instructions, State state, PushedArgs pushedArgs)
{
if (state.index < 0 || state.index >= instructions.Count)
{
return(Update.Fail);
}
var instr = instructions[state.index];
if (!Instr.IsFallThrough(instr.OpCode))
{
return(Update.Fail);
}
instr.CalculateStackUsage(false, out int pushes, out int pops);
if (pops == -1)
{
return(Update.Fail);
}
var isDup = instr.OpCode.Code == Code.Dup;
if (isDup)
{
pushes = 1;
pops = 0;
}
if (pushes > 1)
{
return(Update.Fail);
}
if (state.skipPushes > 0)
{
state.skipPushes -= pushes;
if (state.skipPushes < 0)
{
return(Update.Fail);
}
state.skipPushes += pops;
}
else
{
if (pushes == 1)
{
if (isDup)
{
state.addPushes++;
}
else
{
for (; state.addPushes > 0; state.addPushes--)
{
pushedArgs.Add(instr);
state.validArgs++;
if (!pushedArgs.CanAddMore)
{
return(Update.Finish);
}
}
state.addPushes = 1;
}
}
state.skipPushes += pops;
}
return(Update.Ok);
}
