Merge pull request #2541 from ethereum/asm-bitshift

Add bit shifting opcodes (EIP145)

docs/assembly.rst

@@ -206,6 +206,12 @@ In the grammar, opcodes are represented as pre-defined identifiers.
 +-------------------------+-----+---+-----------------------------------------------------------------+
 | byte(n, x)              |     | F | nth byte of x, where the most significant byte is the 0th byte  |
 +-------------------------+-----+---+-----------------------------------------------------------------+
+| shl(x, y)               |     | C | logical shift left y by x bits                                  |
++-------------------------+-----+---+-----------------------------------------------------------------+
+| shr(x, y)               |     | C | logical shift right y by x bits                                 |
++-------------------------+-----+---+-----------------------------------------------------------------+
+| sar(x, y)               |     | C | arithmetic shift right y by x bits                              |
++-------------------------+-----+---+-----------------------------------------------------------------+
 | addmod(x, y, m)         |     | F | (x + y) % m with arbitrary precision arithmetics                |
 +-------------------------+-----+---+-----------------------------------------------------------------+
 | mulmod(x, y, m)         |     | F | (x * y) % m with arbitrary precision arithmetics                |

libevmasm/Instruction.cpp

@@ -50,6 +50,9 @@ const std::map<std::string, Instruction> dev::solidity::c_instructions =
 	{ "OR", Instruction::OR },
 	{ "XOR", Instruction::XOR },
 	{ "BYTE", Instruction::BYTE },
+	{ "SHL", Instruction::SHL },
+	{ "SHR", Instruction::SHR },
+	{ "SAR", Instruction::SAR },
 	{ "ADDMOD", Instruction::ADDMOD },
 	{ "MULMOD", Instruction::MULMOD },
 	{ "SIGNEXTEND", Instruction::SIGNEXTEND },
@@ -190,6 +193,9 @@ static const std::map<Instruction, InstructionInfo> c_instructionInfo =
 	{ Instruction::OR,			{ "OR",				0, 2, 1, false, Tier::VeryLow } },
 	{ Instruction::XOR,			{ "XOR",			0, 2, 1, false, Tier::VeryLow } },
 	{ Instruction::BYTE,		{ "BYTE",			0, 2, 1, false, Tier::VeryLow } },
+	{ Instruction::SHL,		{ "SHL",			0, 2, 1, false, Tier::VeryLow } },
+	{ Instruction::SHR,		{ "SHR",			0, 2, 1, false, Tier::VeryLow } },
+	{ Instruction::SAR,		{ "SAR",			0, 2, 1, false, Tier::VeryLow } },
 	{ Instruction::ADDMOD,		{ "ADDMOD",			0, 3, 1, false, Tier::Mid } },
 	{ Instruction::MULMOD,		{ "MULMOD",			0, 3, 1, false, Tier::Mid } },
 	{ Instruction::SIGNEXTEND,	{ "SIGNEXTEND",		0, 2, 1, false, Tier::Low } },

libevmasm/Instruction.h

@@ -59,8 +59,11 @@ enum class Instruction: uint8_t
 	AND,				///< bitwise AND operation
 	OR,					///< bitwise OR operation
 	XOR,				///< bitwise XOR operation
-	NOT,				///< bitwise NOT opertation
+	NOT,				///< bitwise NOT operation
 	BYTE,				///< retrieve single byte from word
+	SHL,				///< bitwise SHL operation
+	SHR,				///< bitwise SHR operation
+	SAR,				///< bitwise SAR operation
 
 	KECCAK256 = 0x20,		///< compute KECCAK-256 hash
 

libsolidity/inlineasm/AsmAnalysis.cpp

@@ -548,6 +548,20 @@ void AsmAnalyzer::warnOnInstructions(solidity::Instruction _instr, SourceLocatio
 			"the Metropolis hard fork. Before that it acts as an invalid instruction."
 		);
 
+	static set<solidity::Instruction> experimentalInstructions{
+		solidity::Instruction::SHL,
+		solidity::Instruction::SHR,
+		solidity::Instruction::SAR
+	};
+	if (experimentalInstructions.count(_instr))
+		m_errorReporter.warning(
+			_location,
+			"The \"" +
+			boost::to_lower_copy(instructionInfo(_instr).name)
+			+ "\" instruction is only available after " +
+			"the Constantinople hard fork. Before that it acts as an invalid instruction."
+		);
+
 	if (_instr == solidity::Instruction::JUMP || _instr == solidity::Instruction::JUMPI || _instr == solidity::Instruction::JUMPDEST)
 		m_errorReporter.warning(
 			_location,

test/libsolidity/InlineAssembly.cpp

@@ -774,6 +774,20 @@ BOOST_AUTO_TEST_CASE(create2)
 	BOOST_CHECK(successAssemble("{ pop(create2(10, 0x123, 32, 64)) }"));
 }
 
+BOOST_AUTO_TEST_CASE(shift)
+{
+	BOOST_CHECK(successAssemble("{ pop(shl(10, 32)) }"));
+	BOOST_CHECK(successAssemble("{ pop(shr(10, 32)) }"));
+	BOOST_CHECK(successAssemble("{ pop(sar(10, 32)) }"));
+}
+
+BOOST_AUTO_TEST_CASE(shift_constantinople_warning)
+{
+	CHECK_PARSE_WARNING("{ pop(shl(10, 32)) }", Warning, "The \"shl\" instruction is only available after the Constantinople hard fork");
+	CHECK_PARSE_WARNING("{ pop(shr(10, 32)) }", Warning, "The \"shr\" instruction is only available after the Constantinople hard fork");
+	CHECK_PARSE_WARNING("{ pop(sar(10, 32)) }", Warning, "The \"sar\" instruction is only available after the Constantinople hard fork");
+}
+
 BOOST_AUTO_TEST_CASE(jump_warning)
 {
 	CHECK_PARSE_WARNING("{ 1 jump }", Warning, "Jump instructions");