Performance: Simplify tx.origin check

mythril/analysis/modules/tx_origin.py

@@ -11,19 +11,19 @@ Check for constraints on tx.origin (i.e., access to some functionality is restri
 
 def execute(statespace):
 
-    logging.debug("Executing module: TX_ORIGIN")
+    logging.debug("Executing module: DEPRECIATED OPCODES")
 
     issues = []
 
     for k in statespace.nodes:
         node = statespace.nodes[k]
 
-        for constraint in node.constraints:
+        for instruction in node.instruction_list:
 
-            if(re.search(r'origin', str(constraint))):
+            if(instruction['opcode'] == "ORIGIN"):
 
                 issue = Issue(node.module_name, node.function_name, None,  "Use of tx.origin", "Warning", \
-                    "Access to the function " + node.function_name + " is granted based on tx.origin. Use tx.sender instead.\nSee also: https://solidity.readthedocs.io/en/develop/security-considerations.html#tx-origin"
+                    "Function " + node.function_name + " retrieves the transaction origin (tx.origin) using the ORIGIN opcode. Use tx.sender instead.\nSee also: https://solidity.readthedocs.io/en/develop/security-considerations.html#tx-origin"
                 )
                 
                 issues.append(issue)