something is wrong somewhere but I don't see anything

src/main/java/net/runelite/deob/attributes/code/instruction/types/DupInstruction.java

@@ -4,7 +4,7 @@ import net.runelite.deob.execution.StackContext;
 
 public interface DupInstruction
 {
-	public StackContext resolve(StackContext sctx);
+	public StackContext getOriginal(StackContext sctx);
 	
 	public StackContext getOtherBranch(StackContext sctx);
 }

src/main/java/net/runelite/deob/attributes/code/instructions/Dup.java

@@ -60,7 +60,7 @@ public class Dup extends Instruction implements DupInstruction
 	}
 
 	@Override
-	public StackContext resolve(StackContext sctx)
+	public StackContext getOriginal(StackContext sctx)
 	{
 		// ctx = stack pushed by this instruction, return stack popped by this instruction
 		InstructionContext ctx = sctx.getPushed();

src/main/java/net/runelite/deob/attributes/code/instructions/Dup2.java

@@ -73,7 +73,7 @@ public class Dup2 extends Instruction implements DupInstruction
 	}
 
 	@Override
-	public StackContext resolve(StackContext ctx)
+	public StackContext getOriginal(StackContext ctx)
 	{
 		throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
 	}

src/main/java/net/runelite/deob/attributes/code/instructions/Dup2_X1.java

@@ -81,7 +81,7 @@ public class Dup2_X1 extends Instruction implements DupInstruction
 	}
 
 	@Override
-	public StackContext resolve(StackContext ctx)
+	public StackContext getOriginal(StackContext ctx)
 	{
 		throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
 	}

src/main/java/net/runelite/deob/attributes/code/instructions/Dup2_X2.java

@@ -95,7 +95,7 @@ public class Dup2_X2 extends Instruction implements DupInstruction
 	}
 
 	@Override
-	public StackContext resolve(StackContext ctx)
+	public StackContext getOriginal(StackContext ctx)
 	{
 		throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
 	}

src/main/java/net/runelite/deob/attributes/code/instructions/Dup_X1.java

@@ -56,7 +56,7 @@ public class Dup_X1 extends Instruction implements DupInstruction
 	}
 
 	@Override
-	public StackContext resolve(StackContext sctx)
+	public StackContext getOriginal(StackContext sctx)
 	{
 		// ctx = stack pushed by this instruction, return stack popped by this instruction
 		InstructionContext ctx = sctx.getPushed();

src/main/java/net/runelite/deob/attributes/code/instructions/Dup_X2.java

@@ -71,14 +71,51 @@ public class Dup_X2 extends Instruction implements DupInstruction
 	}
 
 	@Override
-	public StackContext resolve(StackContext ctx)
+	public StackContext getOriginal(StackContext sctx)
 	{
-		throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
+		// 3 2 1 -> 1 3 2 1
+		InstructionContext ctx = sctx.getPushed();
+		assert ctx.getInstruction() == this;
+		
+		assert ctx.getPushes().contains(sctx);
+		int pushedIndex = ctx.getPushes().indexOf(sctx);
+		int poppedIndex;
+		
+		switch (pushedIndex)
+		{
+			case 0:
+			case 3:
+				poppedIndex = 0;
+				break;
+			case 1:
+				poppedIndex = 2;
+				break;
+			case 2:
+				poppedIndex = 1;
+			default:
+				throw new IllegalStateException();
+		}
+		
+		return ctx.getPops().get(poppedIndex);
 	}
 
 	@Override
 	public StackContext getOtherBranch(StackContext sctx)
 	{
-		throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
+		// sctx = stack pushed by this instruction, return the other branch
+		InstructionContext ctx = sctx.getPushed();
+		assert ctx.getInstruction() == this;
+		
+		assert ctx.getPushes().contains(sctx);
+		int pushedIndex = ctx.getPushes().indexOf(sctx);
+		
+		// 3 2 1 -> 1 3 2 1
+		
+		if (pushedIndex == 0)
+			return ctx.getPushes().get(3);
+		else if (pushedIndex == 3)
+			return ctx.getPushes().get(0);
+		
+		return null;
 	}
 }

src/main/java/net/runelite/deob/deobfuscators/arithmetic/MultiplicationDeobfuscator.java

@@ -120,9 +120,10 @@ public class MultiplicationDeobfuscator implements Deobfuscator
 				}
 				else if (i.getInstruction() instanceof DupInstruction)
 				{
+					if(true) throw new IllegalStateException();
 					DupInstruction dup = (DupInstruction) i.getInstruction();
 					
-					if (dup instanceof Dup || dup instanceof Dup_X1)
+					//if (dup instanceof Dup || dup instanceof Dup_X1)
 					{
 					
 						// find other branch of the dup instruction
@@ -139,7 +140,7 @@ public class MultiplicationDeobfuscator implements Deobfuscator
 
 							me.dupmagic = pushConstant;
 
-							StackContext orig = dup.resolve(sctx); // original
+							StackContext orig = dup.getOriginal(sctx); // original
 							try
 							{
 								MultiplicationExpression other = parseExpression(orig.getPushed());
@@ -152,7 +153,8 @@ public class MultiplicationDeobfuscator implements Deobfuscator
 						}
 						else
 						{
-							System.out.println("dup ins " + i);
+							System.out.println("dup ins " + otherCtxI.getInstruction());
+							throw new IllegalStateException();
 						}
 					}
 				}