Merge pull request #3798 from ethereum/commutative-swap

Remove useless SWAP1 in front of commutative operations

1 files changed, 76 insertions, 0 deletions

diff --git a/test/libevmasm/Optimiser.cpp b/test/libevmasm/Optimiser.cpp
index 28f6b8c0..b622b4fb 100644
--- a/test/libevmasm/Optimiser.cpp
+++ b/test/libevmasm/Optimiser.cpp
@@ -858,6 +858,82 @@ BOOST_AUTO_TEST_CASE(peephole_pop_calldatasize)
 	BOOST_CHECK(items.empty());
 }
 
+BOOST_AUTO_TEST_CASE(peephole_commutative_swap1)
+{
+	vector<Instruction> ops{
+		Instruction::ADD,
+		Instruction::MUL,
+		Instruction::EQ,
+		Instruction::AND,
+		Instruction::OR,
+		Instruction::XOR
+	};
+	for (Instruction const op: ops)
+	{
+		AssemblyItems items{
+			u256(1),
+			u256(2),
+			Instruction::SWAP1,
+			op,
+			u256(4),
+			u256(5)
+		};
+		AssemblyItems expectation{
+			u256(1),
+			u256(2),
+			op,
+			u256(4),
+			u256(5)
+		};
+		PeepholeOptimiser peepOpt(items);
+		BOOST_REQUIRE(peepOpt.optimise());
+		BOOST_CHECK_EQUAL_COLLECTIONS(
+		items.begin(), items.end(),
+			expectation.begin(), expectation.end()
+		);
+	}
+}
+
+BOOST_AUTO_TEST_CASE(peephole_noncommutative_swap1)
+{
+	// NOTE: not comprehensive
+	vector<Instruction> ops{
+		Instruction::SUB,
+		Instruction::DIV,
+		Instruction::SDIV,
+		Instruction::MOD,
+		Instruction::SMOD,
+		Instruction::EXP,
+		Instruction::LT,
+		Instruction::GT
+	};
+	for (Instruction const op: ops)
+	{
+		AssemblyItems items{
+			u256(1),
+			u256(2),
+			Instruction::SWAP1,
+			op,
+			u256(4),
+			u256(5)
+		};
+		AssemblyItems expectation{
+			u256(1),
+			u256(2),
+			Instruction::SWAP1,
+			op,
+			u256(4),
+			u256(5)
+		};
+		PeepholeOptimiser peepOpt(items);
+		BOOST_REQUIRE(!peepOpt.optimise());
+		BOOST_CHECK_EQUAL_COLLECTIONS(
+		items.begin(), items.end(),
+			expectation.begin(), expectation.end()
+		);
+	}
+}
+
 BOOST_AUTO_TEST_CASE(jumpdest_removal)
 {
 	AssemblyItems items{