// This is before the expression is processed, so ILValue's and constants havn't been assigned
public bool SimplifyTernaryOperator(IList <ILNode> body, ILBasicBlock head, int pos)
{
Debug.Assert(body.Contains(head));
// Debug.Assert((head.Body[0] as ILLabel).Name != "Block_54");
// Debug.Assert((head.Body[0] as ILLabel).Name != "L1257");
ILExpression condExpr;
ILLabel trueLabel;
ILLabel falseLabel;
ILExpression trueExpr;
ILLabel trueFall;
ILExpression falseExpr;
ILLabel falseFall;
ILLabel finalFalseFall;
ILLabel finalTrueFall;
if (head.MatchLastAndBr(GMCode.Bt, out trueLabel, out condExpr, out falseLabel) &&
labelGlobalRefCount[trueLabel] == 1 &&
labelGlobalRefCount[falseLabel] == 1 &&
labelToBasicBlock[trueLabel].MatchSingleAndBr(GMCode.Push, out trueExpr, out trueFall) &&
labelToBasicBlock[falseLabel].MatchSingleAndBr(GMCode.Push, out falseExpr, out falseFall) &&
trueFall == falseFall &&
body.Contains(labelToBasicBlock[trueFall])
// finalFall.Code == GMCode.Pop
) // (finalFall == null || finalFall.Code == GMCode.Pop)
{
ILBasicBlock trueBlock = labelToBasicBlock[trueLabel];
ILBasicBlock falseBlock = labelToBasicBlock[falseLabel];
ILBasicBlock fallBlock = labelToBasicBlock[trueFall];
ILExpression newExpr = ResolveTernaryExpression(condExpr, trueExpr, falseExpr);
head.Body.RemoveTail(GMCode.Bt, GMCode.B);
body.RemoveOrThrow(trueBlock);
body.RemoveOrThrow(falseBlock);
IList <ILExpression> finalFall;
// figure out if its a wierd short or not
if (fallBlock.MatchSingleAndBr(GMCode.Bt, out finalTrueFall, out finalFall, out finalFalseFall) &&
finalFall.Count == 0)
{
head.Body.Add(new ILExpression(GMCode.Bt, finalTrueFall, newExpr));
if (labelGlobalRefCount[trueFall] == 2)
{
body.RemoveOrThrow(fallBlock);
}
}
else if (fallBlock.Body.Count == 2) // wierd break,
{
finalFalseFall = fallBlock.GotoLabel();
head.Body.Add(new ILExpression(GMCode.Push, null, newExpr)); // we want to push it for next pass
if (labelGlobalRefCount[trueFall] == 2)
{
body.RemoveOrThrow(fallBlock);
}
}
else if (fallBlock.MatchAt(1, GMCode.Pop)) // generated? wierd instance?
{
finalFalseFall = fallBlock.EntryLabel();
error.Info("Wierd Generated Pop here", newExpr);
head.Body.Add(new ILExpression(GMCode.Push, null, newExpr));
// It should be combined in JoinBasicBlocks function
// so don't remove failblock
}
else if (fallBlock.MatchAt(1, GMCode.Assign, out finalFall)) // This is an assignment case and unsure what its for
{
finalFall.Add(newExpr);
finalFalseFall = fallBlock.EntryLabel();
}
if (finalFalseFall == null && fallBlock.MatchLastAt(1, GMCode.Ret))
{
head.Body.Add(new ILExpression(GMCode.Ret, null));
}
else
{
Debug.Assert(finalFalseFall != null);
head.Body.Add(new ILExpression(GMCode.B, finalFalseFall));
}
return(true);
}
return(false);
}
public bool DetectSwitch_GenerateBranches(IList <ILNode> body, ILBasicBlock head, int pos)
{
bool modified = false;
ILExpression condition;
ILLabel trueLabel;
ILLabel falseLabel;
ILLabel fallThough;
// Debug.Assert(head.EntryLabel().Name != "Block_473");
if (MatchSwitchCase(head, out trueLabel, out fallThough, out condition)) // we ignore this first match, but remember the position
{
List <ILExpression> cases = new List <ILExpression>();
List <ILNode> caseBlocks = new List <ILNode>();
ILLabel prev = head.EntryLabel();
ILBasicBlock startOfCases = head;
cases.Add(PreSetUpCaseBlock(startOfCases, condition));
caseBlocks.Add(startOfCases);
for (int i = pos - 1; i >= 0; i--)
{
ILBasicBlock bb = body[i] as ILBasicBlock;
if (MatchSwitchCase(bb, out trueLabel, out falseLabel, out condition))
{
caseBlocks.Add(bb);
cases.Add(PreSetUpCaseBlock(bb, condition));
Debug.Assert(falseLabel == prev);
prev = bb.EntryLabel();
startOfCases = bb;
}
else
{
break;
}
}
// we have all the cases
// head is at the "head" of the cases
ILExpression left;
if (startOfCases.Body[startOfCases.Body.Count - 3].Match(GMCode.Push, out left))
{
startOfCases.Body.RemoveAt(startOfCases.Body.Count - 3);
foreach (var e in cases)
{
e.Arguments.Insert(0, new ILExpression(left)); // add the expression to all the branches
}
}
else
{
throw new Exception("switch failure");
}
// It seems GM makes a default case that just jumps to the end of the switch but I cannot
// rely on it always being there
ILBasicBlock default_case = body[pos + 1] as ILBasicBlock;
Debug.Assert(default_case.EntryLabel() == head.GotoLabel());
ILBasicBlock end_of_switch = labelToBasicBlock[default_case.GotoLabel()];
if ((end_of_switch.Body[1] as ILExpression).Code == GMCode.Popz)
{
end_of_switch.Body.RemoveAt(1); // yeaa!
}
else // booo
{ // We have a default case so now we have to find where the popz ends,
// this could be bad if we had a wierd generated for loop, but we are just doing stupid search
ILBasicBlock test1 = FindEndOfSwitch(end_of_switch);
// we take a sample from one of the cases to make sure we do end up at the same place
ILBasicBlock test2 = FindEndOfSwitch(head);
if (test1 == test2)
{ // two matches are good enough for me
test1.Body.RemoveAt(1); // yeaa!
}
else
{
error.Error("Cannot find end of switch", end_of_switch); // booo
}
}
// tricky part, finding that damn popz
// Ok, we have all the case blocks, they are all fixed, and its like a big chain of ifs now.
// But for anything OTHER than lua that has switch statments, we want to mark this for latter
modified |= true;
}
return(modified);
}
