Remove unnecessary masking of the result of known short instructions

Author: axic

Changelog.md

@@ -1,6 +1,7 @@
 ### 0.4.23 (unreleased)
 
 Features:
+ * Optimizer: Remove unnecessary masking of the result of known short instructions (``ADDRESS``, ``CALLER``, ``ORIGIN`` and ``COINBASE``).
  * SMTChecker: Integration with CVC4 SMT solver
 
 Bugfixes:

libevmasm/RuleList.h

@@ -174,6 +174,18 @@ std::vector<SimplificationRule<Pattern>> simplificationRuleList(
 		});
 	}
 
+	for (auto const& op: std::vector<Instruction>{
+		Instruction::ADDRESS,
+		Instruction::CALLER,
+		Instruction::ORIGIN,
+		Instruction::COINBASE
+	})
+		rules.push_back({
+			{Instruction::AND, {{u256("0xffffffffffffffffffffffffffffffffffffffff"), op}}},
+			[=]() -> Pattern { return op; },
+			false
+		});
+
 	// Double negation of opcodes with boolean result
 	for (auto const& op: std::vector<Instruction>{
 		Instruction::EQ,