Merge pull request #5677 from ethereum/someOpts

Some optimisations.

3 files changed, 21 insertions, 12 deletions

diff --git a/libevmasm/AssemblyItem.h b/libevmasm/AssemblyItem.h
index a7875171..d21be199 100644
--- a/libevmasm/AssemblyItem.h
+++ b/libevmasm/AssemblyItem.h
@@ -57,22 +57,26 @@ class AssemblyItem
 public:
 	enum class JumpType { Ordinary, IntoFunction, OutOfFunction };
 
-	AssemblyItem(u256 _push, langutil::SourceLocation const& _location = langutil::SourceLocation()):
-		AssemblyItem(Push, _push, _location) { }
-	AssemblyItem(solidity::Instruction _i, langutil::SourceLocation const& _location = langutil::SourceLocation()):
+	AssemblyItem(u256 _push, langutil::SourceLocation _location = langutil::SourceLocation()):
+		AssemblyItem(Push, std::move(_push), std::move(_location)) { }
+	AssemblyItem(solidity::Instruction _i, langutil::SourceLocation _location = langutil::SourceLocation()):
 		m_type(Operation),
 		m_instruction(_i),
-		m_location(_location)
+		m_location(std::move(_location))
 	{}
-	AssemblyItem(AssemblyItemType _type, u256 _data = 0, langutil::SourceLocation const& _location = langutil::SourceLocation()):
+	AssemblyItem(AssemblyItemType _type, u256 _data = 0, langutil::SourceLocation _location = langutil::SourceLocation()):
 		m_type(_type),
-		m_location(_location)
+		m_location(std::move(_location))
 	{
 		if (m_type == Operation)
 			m_instruction = Instruction(uint8_t(_data));
 		else
-			m_data = std::make_shared<u256>(_data);
+			m_data = std::make_shared<u256>(std::move(_data));
 	}
+	AssemblyItem(AssemblyItem const&) = default;
+	AssemblyItem(AssemblyItem&&) = default;
+	AssemblyItem& operator=(AssemblyItem const&) = default;
+	AssemblyItem& operator=(AssemblyItem&&) = default;
 
 	AssemblyItem tag() const { assertThrow(m_type == PushTag || m_type == Tag, Exception, ""); return AssemblyItem(Tag, data()); }
 	AssemblyItem pushTag() const { assertThrow(m_type == PushTag || m_type == Tag, Exception, ""); return AssemblyItem(PushTag, data()); }
@@ -114,6 +118,13 @@ public:
 			return data() < _other.data();
 	}
 
+	/// Shortcut that avoids constructing an AssemblyItem just to perform the comparison.
+	bool operator==(Instruction _instr) const
+	{
+		return type() == Operation && instruction() == _instr;
+	}
+	bool operator!=(Instruction _instr) const { return !operator==(_instr); }
+
 	/// @returns an upper bound for the number of bytes required by this item, assuming that
 	/// the value of a jump tag takes @a _addressLength bytes.
 	unsigned bytesRequired(unsigned _addressLength) const;
diff --git a/libevmasm/PeepholeOptimiser.cpp b/libevmasm/PeepholeOptimiser.cpp
index f3ae8cbf..e211026b 100644
--- a/libevmasm/PeepholeOptimiser.cpp
+++ b/libevmasm/PeepholeOptimiser.cpp
@@ -160,8 +160,7 @@ struct CommutativeSwap: SimplePeepholeOptimizerMethod<CommutativeSwap, 2>
 	{
 		// Remove SWAP1 if following instruction is commutative
 		if (
-			_swap.type() == Operation &&
-			_swap.instruction() == Instruction::SWAP1 &&
+			_swap == Instruction::SWAP1 &&
 			SemanticInformation::isCommutativeOperation(_op)
 		)
 		{
@@ -185,8 +184,7 @@ struct SwapComparison: SimplePeepholeOptimizerMethod<SwapComparison, 2>
 		};
 
 		if (
-			_swap.type() == Operation &&
-			_swap.instruction() == Instruction::SWAP1 &&
+			_swap == Instruction::SWAP1 &&
 			_op.type() == Operation &&
 			swappableOps.count(_op.instruction())
 		)
diff --git a/libevmasm/SemanticInformation.cpp b/libevmasm/SemanticInformation.cpp
index 78f3c9c7..2a24a27e 100644
--- a/libevmasm/SemanticInformation.cpp
+++ b/libevmasm/SemanticInformation.cpp
@@ -108,7 +108,7 @@ bool SemanticInformation::isSwapInstruction(AssemblyItem const& _item)
 
 bool SemanticInformation::isJumpInstruction(AssemblyItem const& _item)
 {
-	return _item == AssemblyItem(Instruction::JUMP) || _item == AssemblyItem(Instruction::JUMPI);
+	return _item == Instruction::JUMP || _item == Instruction::JUMPI;
 }
 
 bool SemanticInformation::altersControlFlow(AssemblyItem const& _item)