Correctly use not/bnot/iszero.

A long time ago, some opcodes were renamed. Now we should only have not (bitwise negation) and iszero (logical negation).
Adam23 · May 9, 2016 · a927efb · a927efb
1 parent 9e36bdd
commit a927efb
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Showing 3 changed files with 25 additions and 5 deletions.
diff --git a/docs/control-structures.rst b/docs/control-structures.rst
@@ -208,7 +208,7 @@ idea is that assembly libraries will be used to enhance the language in such way
 				// by using o_code = new bytes(size)
 				o_code := mload(0x40)
 				// new "memory end" including padding
-				mstore(0x40, add(o_code, and(add(add(size, 0x20), 0x1f), bnot(0x1f))))
+				mstore(0x40, add(o_code, and(add(add(size, 0x20), 0x1f), not(0x1f))))
 				// store length in memory
 				mstore(o_code, size)
 				// actually retrieve the code, this needs assembly
@@ -292,7 +292,7 @@ The opcodes `pushi` and `jumpdest` cannot be used directly.
 +-----------------------+------+---------------------------------------------------------------+
 | exp(x, y)             |      | x to the power of y                                           |
 +-----------------------+------+---------------------------------------------------------------+
-| bnot(x)               |      | ~x, every bit of x is negated                                 |
+| not(x)                |      | ~x, every bit of x is negated                                 |
 +-----------------------+------+---------------------------------------------------------------+
 | lt(x, y)              |      | 1 if x < y, 0 otherwise                                       |
 +-----------------------+------+---------------------------------------------------------------+
@@ -304,7 +304,7 @@ The opcodes `pushi` and `jumpdest` cannot be used directly.
 +-----------------------+------+---------------------------------------------------------------+
 | eq(x, y)              |      | 1 if x == y, 0 otherwise                                      |
 +-----------------------+------+---------------------------------------------------------------+
-| not(x)                |      | 1 if x == 0, 0 otherwise                                      |
+| iszero(x)             |      | 1 if x == 0, 0 otherwise                                      |
 +-----------------------+------+---------------------------------------------------------------+
 | and(x, y)             |      | bitwise and of x and y                                        |
 +-----------------------+------+---------------------------------------------------------------+

diff --git a/libevmasm/Instruction.cpp b/libevmasm/Instruction.cpp
@@ -39,13 +39,13 @@ const std::map<std::string, Instruction> dev::solidity::c_instructions =
 	{ "MOD", Instruction::MOD },
 	{ "SMOD", Instruction::SMOD },
 	{ "EXP", Instruction::EXP },
-	{ "BNOT", Instruction::NOT },
+	{ "NOT", Instruction::NOT },
 	{ "LT", Instruction::LT },
 	{ "GT", Instruction::GT },
 	{ "SLT", Instruction::SLT },
 	{ "SGT", Instruction::SGT },
 	{ "EQ", Instruction::EQ },
-	{ "NOT", Instruction::ISZERO },
+	{ "ISZERO", Instruction::ISZERO },
 	{ "AND", Instruction::AND },
 	{ "OR", Instruction::OR },
 	{ "XOR", Instruction::XOR },

diff --git a/test/libsolidity/SolidityEndToEndTest.cpp b/test/libsolidity/SolidityEndToEndTest.cpp
@@ -6735,6 +6735,26 @@ BOOST_AUTO_TEST_CASE(internal_library_function_return_var_size)
 	BOOST_CHECK(callContractFunction("f()") == encodeArgs(u256(2)));
 }
 
+BOOST_AUTO_TEST_CASE(iszero_bnot_correct)
+{
+	// A long time ago, some opcodes were renamed, which involved the opcodes
+	// "iszero" and "not".
+	char const* sourceCode = R"(
+		contract C {
+			function f() returns (bool) {
+				bytes32 x = 1;
+				assembly { x := not(x) }
+				if (x != ~bytes32(1)) return false;
+				assembly { x := iszero(x) }
+				if (x != bytes32(0)) return false;
+				return true;
+			}
+		}
+	)";
+	compileAndRun(sourceCode, 0, "C");
+	BOOST_CHECK(callContractFunction("f()") == encodeArgs(true));
+}
+
 BOOST_AUTO_TEST_SUITE_END()
 
 }