Minor correction

src/main/java/chocopy/pa3/CodeGenImpl.java

@@ -739,7 +739,7 @@ public class CodeGenImpl extends CodeGenBase
                 sp_off -= 2;
                 backend.emitADDI(SP, FP, -sp_off*wordSize, "restore sp");
                 }
-                if(operator.equals("!="))
+                else if(operator.equals("!="))
                 {
                 incSp(2);
                 backend.emitSW(node.left.dispatch(this), FP, (1 - sp_off) *wordSize, "Push argument 0 from last.");
@@ -755,7 +755,7 @@ public class CodeGenImpl extends CodeGenBase
                     backend.emitSW(node.left.dispatch(this), FP, (1 - sp_off) *wordSize, "Push argument 0 from last.");
                     backend.emitSW(node.right.dispatch(this), FP, ( - sp_off) *wordSize, "Push argument 1 from last.");
                     backend.emitADDI(SP, FP, -sp_off * wordSize, "Set SP to last argument.");
-                    backend.emitJAL(concatLabel, "Invoke method:concat");
+                    backend.emitJAL(strcatLabel, "Invoke method:strcat");
                     sp_off -= 2;
                     backend.emitADDI(SP, FP, -sp_off*wordSize, "restore sp");
                 }