diff --git a/alethzero/MainWin.cpp b/alethzero/MainWin.cpp
index 5d4f9770e..7fdb058d8 100644
--- a/alethzero/MainWin.cpp
+++ b/alethzero/MainWin.cpp
@@ -1059,8 +1059,7 @@ void Main::refreshBlockCount()
 {
 	cwatch << "refreshBlockCount()";
 	auto d = ethereum()->blockChain().details();
-	auto diff = BlockInfo(ethereum()->blockChain().block()).difficulty;
-	ui->blockCount->setText(QString("%6 #%1 @%3 T%2 PV%4 D%5").arg(d.number).arg(toLog2(d.totalDifficulty)).arg(toLog2(diff)).arg(c_protocolVersion).arg(c_databaseVersion).arg(m_privateChain.size() ? "[" + m_privateChain + "] " : "testnet"));
+	ui->blockCount->setText(QString("%4 #%1 PV%2 D%3 H%5").arg(d.number).arg(c_protocolVersion).arg(c_databaseVersion).arg(m_privateChain.size() ? "[" + m_privateChain + "] " : "testnet").arg(c_ethashVersion));
 }
 
 void Main::on_turboMining_triggered()
@@ -1429,63 +1428,64 @@ void Main::on_blocks_currentItemChanged()
 			s << "<h3>" << h << "</h3>";
 			s << "<h4>#" << info.number;
 			s << "&nbsp;&emsp;&nbsp;<b>" << timestamp << "</b></h4>";
-			s << "<br/>D/TD: <b>" << info.difficulty << "</b>/<b>" << details.totalDifficulty << "</b> = 2^" << log2((double)info.difficulty) << "/2^" << log2((double)details.totalDifficulty);
-			s << "&nbsp;&emsp;&nbsp;Children: <b>" << details.children.size() << "</b></h5>";
-			s << "<br/>Gas used/limit: <b>" << info.gasUsed << "</b>/<b>" << info.gasLimit << "</b>";
-			s << "<br/>Coinbase: <b>" << pretty(info.coinbaseAddress).toHtmlEscaped().toStdString() << "</b> " << info.coinbaseAddress;
-			s << "<br/>Seed hash: <b>" << info.seedHash() << "</b>";
-			s << "<br/>Mix hash: <b>" << info.mixHash << "</b>";
-			s << "<br/>Nonce: <b>" << info.nonce << "</b>";
-			s << "<br/>Hash w/o nonce: <b>" << info.headerHash(WithoutNonce) << "</b>";
-			s << "<br/>Difficulty: <b>" << info.difficulty << "</b>";
+			s << "<div>D/TD: <b>" << info.difficulty << "</b>/<b>" << details.totalDifficulty << "</b> = 2^" << log2((double)info.difficulty) << "/2^" << log2((double)details.totalDifficulty) << "</div>";
+			s << "&nbsp;&emsp;&nbsp;Children: <b>" << details.children.size() << "</b></div>";
+			s << "<div>Gas used/limit: <b>" << info.gasUsed << "</b>/<b>" << info.gasLimit << "</b>" << "</div>";
+			s << "<div>Beneficiary: <b>" << pretty(info.coinbaseAddress).toHtmlEscaped().toStdString() << " " << info.coinbaseAddress << "</b>" << "</div>";
+			s << "<div>Seed hash: <b>" << info.seedHash() << "</b>" << "</div>";
+			s << "<div>Mix hash: <b>" << info.mixHash << "</b>" << "</div>";
+			s << "<div>Nonce: <b>" << info.nonce << "</b>" << "</div>";
+			s << "<div>Hash w/o nonce: <b>" << info.headerHash(WithoutNonce) << "</b>" << "</div>";
+			s << "<div>Difficulty: <b>" << info.difficulty << "</b>" << "</div>";
 			if (info.number)
 			{
 				auto e = Ethasher::eval(info);
-				s << "<br/>Proof-of-Work: <b>" << e.value << " &lt;= " << (h256)u256((bigint(1) << 256) / info.difficulty) << "</b> (mixhash: " << e.mixHash.abridged() << ")";
-				s << "<br/>Parent: <b>" << info.parentHash << "</b>";
+				s << "<div>Proof-of-Work: <b>" << e.value << " &lt;= " << (h256)u256((bigint(1) << 256) / info.difficulty) << "</b> (mixhash: " << e.mixHash.abridged() << ")" << "</div>";
+				s << "<div>Parent: <b>" << info.parentHash << "</b>" << "</div>";
 			}
 			else
 			{
-				s << "<br/>Proof-of-Work: <i>Phil has nothing to prove</i>";
-				s << "<br/>Parent: <i>It was a virgin birth</i>";
+				s << "<div>Proof-of-Work: <b><i>Phil has nothing to prove</i></b></div>";
+				s << "<div>Parent: <b><i>It was a virgin birth</i></b></div>";
 			}
-//			s << "<br/>Bloom: <b>" << details.bloom << "</b>";
+//			s << "<div>Bloom: <b>" << details.bloom << "</b>";
 			if (!!info.logBloom)
 				s << "<div>Log Bloom: " << info.logBloom << "</div>";
 			else
 				s << "<div>Log Bloom: <i>Uneventful</i></div>";
-			s << "<br/>Transactions: <b>" << block[1].itemCount() << "</b> @<b>" << info.transactionsRoot << "</b>";
-			s << "<br/>Receipts: @<b>" << info.receiptsRoot << "</b>:";
-			s << "<br/>Uncles: <b>" << block[2].itemCount() << "</b> @<b>" << info.sha3Uncles << "</b>";
+			s << "<div>Transactions: <b>" << block[1].itemCount() << "</b> @<b>" << info.transactionsRoot << "</b>" << "</div>";
+			s << "<div>Uncles: <b>" << block[2].itemCount() << "</b> @<b>" << info.sha3Uncles << "</b>" << "</div>";
 			for (auto u: block[2])
 			{
 				BlockInfo uncle = BlockInfo::fromHeader(u.data());
-				char const* line = "<br/><span style=\"margin-left: 2em\">&nbsp;</span>";
-				s << line << "Hash: <b>" << uncle.hash << "</b>";
-				s << line << "Parent: <b>" << uncle.parentHash << "</b>";
-				s << line << "Number: <b>" << uncle.number << "</b>";
-				s << line << "Coinbase: <b>" << pretty(uncle.coinbaseAddress).toHtmlEscaped().toStdString() << "</b> " << uncle.coinbaseAddress;
-				s << line << "Seed hash: <b>" << uncle.seedHash() << "</b>";
-				s << line << "Mix hash: <b>" << uncle.mixHash << "</b>";
-				s << line << "Nonce: <b>" << uncle.nonce << "</b>";
-				s << line << "Hash w/o nonce: <b>" << uncle.headerHash(WithoutNonce) << "</b>";
-				s << line << "Difficulty: <b>" << uncle.difficulty << "</b>";
+				char const* line = "<div><span style=\"margin-left: 2em\">&nbsp;</span>";
+				s << line << "Hash: <b>" << uncle.hash << "</b>" << "</div>";
+				s << line << "Parent: <b>" << uncle.parentHash << "</b>" << "</div>";
+				s << line << "Number: <b>" << uncle.number << "</b>" << "</div>";
+				s << line << "Coinbase: <b>" << pretty(uncle.coinbaseAddress).toHtmlEscaped().toStdString() << " " << uncle.coinbaseAddress << "</b>" << "</div>";
+				s << line << "Seed hash: <b>" << uncle.seedHash() << "</b>" << "</div>";
+				s << line << "Mix hash: <b>" << uncle.mixHash << "</b>" << "</div>";
+				s << line << "Nonce: <b>" << uncle.nonce << "</b>" << "</div>";
+				s << line << "Hash w/o nonce: <b>" << uncle.headerHash(WithoutNonce) << "</b>" << "</div>";
+				s << line << "Difficulty: <b>" << uncle.difficulty << "</b>" << "</div>";
 				auto e = Ethasher::eval(uncle);
-				s << line << "Proof-of-Work: <b>" << e.value << " &lt;= " << (h256)u256((bigint(1) << 256) / uncle.difficulty) << "</b> (mixhash: " << e.mixHash.abridged() << ")";
+				s << line << "Proof-of-Work: <b>" << e.value << " &lt;= " << (h256)u256((bigint(1) << 256) / uncle.difficulty) << "</b> (mixhash: " << e.mixHash.abridged() << ")" << "</div>";
 			}
 			if (info.parentHash)
-				s << "<br/>Pre: <b>" << BlockInfo(ethereum()->blockChain().block(info.parentHash)).stateRoot << "</b>";
+				s << "<div>Pre: <b>" << BlockInfo(ethereum()->blockChain().block(info.parentHash)).stateRoot << "</b>" << "</div>";
 			else
-				s << "<br/>Pre: <i>Nothing is before Phil</i>";
+				s << "<div>Pre: <b><i>Nothing is before Phil</i></b>" << "</div>";
+
+			s << "<div>Receipts: @<b>" << info.receiptsRoot << "</b>:" << "</div>";
 			BlockReceipts receipts = ethereum()->blockChain().receipts(h);
 			unsigned ii = 0;
 			for (auto const& i: block[1])
 			{
-				s << "<br/>" << sha3(i.data()).abridged() << ": <b>" << receipts.receipts[ii].stateRoot() << "</b> [<b>" << receipts.receipts[ii].gasUsed() << "</b> used]";
+				s << "<div>" << sha3(i.data()).abridged() << ": <b>" << receipts.receipts[ii].stateRoot() << "</b> [<b>" << receipts.receipts[ii].gasUsed() << "</b> used]" << "</div>";
 				++ii;
 			}
-			s << "<br/>Post: <b>" << info.stateRoot << "</b>";
-			s << "<br/>Dump: " Span(Mono) << toHex(block[0].data()) << "</span>";
+			s << "<div>Post: <b>" << info.stateRoot << "</b>" << "</div>";
+			s << "<div>Dump: " Span(Mono) << toHex(block[0].data()) << "</span>" << "</div>";
 			s << "<div>Receipts-Hex: " Span(Mono) << toHex(receipts.rlp()) << "</span></div>";
 		}
 		else
@@ -1497,19 +1497,19 @@ void Main::on_blocks_currentItemChanged()
 			TransactionReceipt receipt = ethereum()->blockChain().receipts(h).receipts[txi];
 			s << "<h3>" << th << "</h3>";
 			s << "<h4>" << h << "[<b>" << txi << "</b>]</h4>";
-			s << "<br/>From: <b>" << pretty(ss).toHtmlEscaped().toStdString() << "</b> " << ss;
+			s << "<div>From: <b>" << pretty(ss).toHtmlEscaped().toStdString() << " " << ss << "</b>" << "</div>";
 			if (tx.isCreation())
-				s << "<br/>Creates: <b>" << pretty(right160(th)).toHtmlEscaped().toStdString() << "</b> " << right160(th);
+				s << "<div>Creates: <b>" << pretty(right160(th)).toHtmlEscaped().toStdString() << "</b> " << right160(th) << "</div>";
 			else
-				s << "<br/>To: <b>" << pretty(tx.receiveAddress()).toHtmlEscaped().toStdString() << "</b> " << tx.receiveAddress();
-			s << "<br/>Value: <b>" << formatBalance(tx.value()) << "</b>";
-			s << "&nbsp;&emsp;&nbsp;#<b>" << tx.nonce() << "</b>";
-			s << "<br/>Gas price: <b>" << formatBalance(tx.gasPrice()) << "</b>";
-			s << "<br/>Gas: <b>" << tx.gas() << "</b>";
-			s << "<br/>V: <b>" << hex << nouppercase << (int)tx.signature().v << " + 27</b>";
-			s << "<br/>R: <b>" << hex << nouppercase << tx.signature().r << "</b>";
-			s << "<br/>S: <b>" << hex << nouppercase << tx.signature().s << "</b>";
-			s << "<br/>Msg: <b>" << tx.sha3(eth::WithoutSignature) << "</b>";
+				s << "<div>To: <b>" << pretty(tx.receiveAddress()).toHtmlEscaped().toStdString() << "</b> " << tx.receiveAddress() << "</div>";
+			s << "<div>Value: <b>" << formatBalance(tx.value()) << "</b>" << "</div>";
+			s << "&nbsp;&emsp;&nbsp;#<b>" << tx.nonce() << "</b>" << "</div>";
+			s << "<div>Gas price: <b>" << formatBalance(tx.gasPrice()) << "</b>" << "</div>";
+			s << "<div>Gas: <b>" << tx.gas() << "</b>" << "</div>";
+			s << "<div>V: <b>" << hex << nouppercase << (int)tx.signature().v << " + 27</b>" << "</div>";
+			s << "<div>R: <b>" << hex << nouppercase << tx.signature().r << "</b>" << "</div>";
+			s << "<div>S: <b>" << hex << nouppercase << tx.signature().s << "</b>" << "</div>";
+			s << "<div>Msg: <b>" << tx.sha3(eth::WithoutSignature) << "</b>" << "</div>";
 			if (!tx.data().empty())
 			{
 				if (tx.isCreation())
@@ -1522,7 +1522,7 @@ void Main::on_blocks_currentItemChanged()
 			if (!!receipt.bloom())
 				s << "<div>Log Bloom: " << receipt.bloom() << "</div>";
 			else
-				s << "<div>Log Bloom: <i>Uneventful</i></div>";
+				s << "<div>Log Bloom: <b><i>Uneventful</i></b></div>";
 			auto r = receipt.rlp();
 			s << "<div>Receipt: " << toString(RLP(r)) << "</div>";
 			s << "<div>Receipt-Hex: " Span(Mono) << toHex(receipt.rlp()) << "</span></div>";
diff --git a/libdevcore/Assertions.h b/libdevcore/Assertions.h
new file mode 100644
index 000000000..7b4a4a765
--- /dev/null
+++ b/libdevcore/Assertions.h
@@ -0,0 +1,111 @@
+/*
+	This file is part of cpp-ethereum.
+
+	cpp-ethereum is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	cpp-ethereum is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with cpp-ethereum.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/**
+ * @file Assertions.h
+ * @author Christian <c@ethdev.com>
+ * @date 2015
+ *
+ * Assertion handling.
+ */
+
+#pragma once
+
+#include "Exceptions.h"
+#include "debugbreak.h"
+
+namespace dev
+{
+
+#if defined(_MSC_VER)
+#define ETH_FUNC __FUNCSIG__
+#elif defined(__GNUC__)
+#define ETH_FUNC __PRETTY_FUNCTION__
+#else
+#define ETH_FUNC __func__
+#endif
+
+#define asserts(A) ::dev::assertAux(A, #A, __LINE__, __FILE__, ETH_FUNC)
+#define assertsEqual(A, B) ::dev::assertEqualAux(A, B, #A, #B, __LINE__, __FILE__, ETH_FUNC)
+
+inline bool assertAux(bool _a, char const* _aStr, unsigned _line, char const* _file, char const* _func)
+{
+	bool ret = _a;
+	if (!ret)
+	{
+		std::cerr << "Assertion failed:" << _aStr << " [func=" << _func << ", line=" << _line << ", file=" << _file << "]" << std::endl;
+#if ETH_DEBUG
+		debug_break();
+#endif
+	}
+	return !ret;
+}
+
+template<class A, class B>
+inline bool assertEqualAux(A const& _a, B const& _b, char const* _aStr, char const* _bStr, unsigned _line, char const* _file, char const* _func)
+{
+	bool ret = _a == _b;
+	if (!ret)
+	{
+		std::cerr << "Assertion failed: " << _aStr << " == " << _bStr << " [func=" << _func << ", line=" << _line << ", file=" << _file << "]" << std::endl;
+		std::cerr << "   Fail equality: " << _a << "==" << _b << std::endl;
+#if ETH_DEBUG
+		debug_break();
+#endif
+	}
+	return !ret;
+}
+
+/// Assertion that throws an exception containing the given description if it is not met.
+/// Use it as assertThrow(1 == 1, ExceptionType, "Mathematics is wrong.");
+/// Do NOT supply an exception object as the second parameter.
+#define assertThrow(_condition, _ExceptionType, _description) \
+	::dev::assertThrowAux<_ExceptionType>(_condition, _description, __LINE__, __FILE__, ETH_FUNC)
+
+using errinfo_comment = boost::error_info<struct tag_comment, std::string>;
+
+template <class _ExceptionType>
+inline void assertThrowAux(
+	bool _condition,
+	::std::string const& _errorDescription,
+	unsigned _line,
+	char const* _file,
+	char const* _function
+)
+{
+	if (!_condition)
+		::boost::throw_exception(
+			_ExceptionType() <<
+			::dev::errinfo_comment(_errorDescription) <<
+			::boost::throw_function(_function) <<
+			::boost::throw_file(_file) <<
+			::boost::throw_line(_line)
+		);
+}
+
+template <class _ExceptionType>
+inline void assertThrowAux(
+	void const* _pointer,
+	::std::string const& _errorDescription,
+	unsigned _line,
+	char const* _file,
+	char const* _function
+)
+{
+	assertThrowAux<_ExceptionType>(_pointer != nullptr, _errorDescription, _line, _file, _function);
+}
+
+}
diff --git a/libdevcore/Common.h b/libdevcore/Common.h
index bf9699b2f..5e778644d 100644
--- a/libdevcore/Common.h
+++ b/libdevcore/Common.h
@@ -44,7 +44,6 @@
 #pragma warning(pop)
 #pragma GCC diagnostic pop
 #include "vector_ref.h"
-#include "debugbreak.h"
 
 // CryptoPP defines byte in the global namespace, so must we.
 using byte = uint8_t;
@@ -135,45 +134,4 @@ private:
 	std::function<void(void)> m_f;
 };
 
-// Assertions...
-
-#if defined(_MSC_VER)
-#define ETH_FUNC __FUNCSIG__
-#elif defined(__GNUC__)
-#define ETH_FUNC __PRETTY_FUNCTION__
-#else
-#define ETH_FUNC __func__
-#endif
-
-#define asserts(A) ::dev::assertAux(A, #A, __LINE__, __FILE__, ETH_FUNC)
-#define assertsEqual(A, B) ::dev::assertEqualAux(A, B, #A, #B, __LINE__, __FILE__, ETH_FUNC)
-
-inline bool assertAux(bool _a, char const* _aStr, unsigned _line, char const* _file, char const* _func)
-{
-	bool ret = _a;
-	if (!ret)
-	{
-		std::cerr << "Assertion failed:" << _aStr << " [func=" << _func << ", line=" << _line << ", file=" << _file << "]" << std::endl;
-#if ETH_DEBUG
-		debug_break();
-#endif
-	}
-	return !ret;
-}
-
-template<class A, class B>
-inline bool assertEqualAux(A const& _a, B const& _b, char const* _aStr, char const* _bStr, unsigned _line, char const* _file, char const* _func)
-{
-	bool ret = _a == _b;
-	if (!ret)
-	{
-		std::cerr << "Assertion failed: " << _aStr << " == " << _bStr << " [func=" << _func << ", line=" << _line << ", file=" << _file << "]" << std::endl;
-		std::cerr << "   Fail equality: " << _a << "==" << _b << std::endl;
-#if ETH_DEBUG
-		debug_break();
-#endif
-	}
-	return !ret;
-}
-
 }
diff --git a/libdevcore/StructuredLogger.cpp b/libdevcore/StructuredLogger.cpp
index 5655b332d..f51ed310a 100644
--- a/libdevcore/StructuredLogger.cpp
+++ b/libdevcore/StructuredLogger.cpp
@@ -38,9 +38,10 @@ void StructuredLogger::outputJson(Json::Value const& _value, std::string const&
 {
 	Json::Value event;
 	static Mutex s_lock;
+	Json::FastWriter fastWriter;
 	Guard l(s_lock);
 	event[_name] = _value;
-	cout << event << endl << flush;
+	cout << fastWriter.write(event) << endl;
 }
 
 void StructuredLogger::starting(string const& _clientImpl, const char* _ethVersion)
diff --git a/libdevcrypto/CryptoPP.cpp b/libdevcrypto/CryptoPP.cpp
index 79fd62262..ff22b9b45 100644
--- a/libdevcrypto/CryptoPP.cpp
+++ b/libdevcrypto/CryptoPP.cpp
@@ -20,6 +20,7 @@
  */
 
 #include <libdevcore/Guards.h>
+#include <libdevcore/Assertions.h>
 #include "ECDHE.h"
 #include "CryptoPP.h"
 
diff --git a/libethcore/Common.cpp b/libethcore/Common.cpp
index 76efc06a2..d26ac0260 100644
--- a/libethcore/Common.cpp
+++ b/libethcore/Common.cpp
@@ -22,6 +22,7 @@
 #include "Common.h"
 #include <random>
 #include <libdevcrypto/SHA3.h>
+#include "Ethasher.h"
 #include "Exceptions.h"
 using namespace std;
 using namespace dev;
@@ -32,15 +33,16 @@ namespace dev
 namespace eth
 {
 
+const unsigned c_ethashVersion = c_ethashRevision;
 const unsigned c_protocolVersion = 58;
 const unsigned c_databaseBaseVersion = 8;
 #if ETH_FATDB
-const unsigned c_databaseVersionModifier = 1000;
+const unsigned c_databaseVersionModifier = 1;
 #else
 const unsigned c_databaseVersionModifier = 0;
 #endif
 
-const unsigned c_databaseVersion = c_databaseBaseVersion + c_databaseVersionModifier;
+const unsigned c_databaseVersion = c_databaseBaseVersion + (c_databaseVersionModifier << 8) + (c_ethashVersion << 9);
 
 vector<pair<u256, string>> const& units()
 {
diff --git a/libethcore/Common.h b/libethcore/Common.h
index 80a253bdd..aabb59d25 100644
--- a/libethcore/Common.h
+++ b/libethcore/Common.h
@@ -38,6 +38,9 @@ extern const unsigned c_protocolVersion;
 /// Current database version.
 extern const unsigned c_databaseVersion;
 
+/// Current database version.
+extern const unsigned c_ethashVersion;
+
 /// User-friendly string representation of the amount _b in wei.
 std::string formatBalance(bigint const& _b);
 
diff --git a/libethereum/BlockChain.cpp b/libethereum/BlockChain.cpp
index 54167f2ad..f80680f38 100644
--- a/libethereum/BlockChain.cpp
+++ b/libethereum/BlockChain.cpp
@@ -26,6 +26,7 @@
 #include <boost/filesystem.hpp>
 #include <test/JsonSpiritHeaders.h>
 #include <libdevcore/Common.h>
+#include <libdevcore/Assertions.h>
 #include <libdevcore/RLP.h>
 #include <libdevcore/StructuredLogger.h>
 #include <libdevcrypto/FileSystem.h>
diff --git a/libethereum/State.cpp b/libethereum/State.cpp
index 9bfc0c08c..638430c3b 100644
--- a/libethereum/State.cpp
+++ b/libethereum/State.cpp
@@ -27,6 +27,7 @@
 #include <boost/timer.hpp>
 #include <secp256k1/secp256k1.h>
 #include <libdevcore/CommonIO.h>
+#include <libdevcore/Assertions.h>
 #include <libdevcore/StructuredLogger.h>
 #include <libevmcore/Instruction.h>
 #include <libethcore/Exceptions.h>
diff --git a/libevm/VMFactory.cpp b/libevm/VMFactory.cpp
index 40f8a3500..1092906e4 100644
--- a/libevm/VMFactory.cpp
+++ b/libevm/VMFactory.cpp
@@ -16,6 +16,7 @@
 */
 
 #include "VMFactory.h"
+#include <libdevcore/Assertions.h>
 #include "VM.h"
 
 #if ETH_EVMJIT
diff --git a/libevmcore/Assembly.cpp b/libevmcore/Assembly.cpp
index 0a0611292..68f326bfd 100644
--- a/libevmcore/Assembly.cpp
+++ b/libevmcore/Assembly.cpp
@@ -47,9 +47,6 @@ unsigned AssemblyItem::bytesRequired(unsigned _addressLength) const
 	case PushData:
 	case PushSub:
 		return 1 + _addressLength;
-	case NoOptimizeBegin:
-	case NoOptimizeEnd:
-		return 0;
 	default:
 		break;
 	}
@@ -61,7 +58,7 @@ int AssemblyItem::deposit() const
 	switch (m_type)
 	{
 	case Operation:
-		return instructionInfo((Instruction)(byte)m_data).ret - instructionInfo((Instruction)(byte)m_data).args;
+		return instructionInfo(instruction()).ret - instructionInfo(instruction()).args;
 	case Push:
 	case PushString:
 	case PushTag:
@@ -91,6 +88,48 @@ string AssemblyItem::getJumpTypeAsString() const
 	}
 }
 
+ostream& dev::eth::operator<<(ostream& _out, AssemblyItem const& _item)
+{
+	switch (_item.type())
+	{
+	case Operation:
+		_out << " " << instructionInfo(_item.instruction()).name;
+		if (_item.instruction() == eth::Instruction::JUMP || _item.instruction() == eth::Instruction::JUMPI)
+			_out << "\t" << _item.getJumpTypeAsString();
+		break;
+	case Push:
+		_out << " PUSH " << hex << _item.data();
+		break;
+	case PushString:
+		_out << " PushString"  << hex << (unsigned)_item.data();
+		break;
+	case PushTag:
+		_out << " PushTag " << _item.data();
+		break;
+	case Tag:
+		_out << " Tag " << _item.data();
+		break;
+	case PushData:
+		_out << " PushData " << hex << (unsigned)_item.data();
+		break;
+	case PushSub:
+		_out << " PushSub " << hex << h256(_item.data()).abridged();
+		break;
+	case PushSubSize:
+		_out << " PushSubSize " << hex << h256(_item.data()).abridged();
+		break;
+	case PushProgramSize:
+		_out << " PushProgramSize";
+		break;
+	case UndefinedItem:
+		_out << " ???";
+		break;
+	default:
+		BOOST_THROW_EXCEPTION(InvalidOpcode());
+	}
+	return _out;
+}
+
 unsigned Assembly::bytesRequired() const
 {
 	for (unsigned br = 1;; ++br)
@@ -145,47 +184,7 @@ void Assembly::append(Assembly const& _a, int _deposit)
 ostream& dev::eth::operator<<(ostream& _out, AssemblyItemsConstRef _i)
 {
 	for (AssemblyItem const& i: _i)
-		switch (i.type())
-		{
-		case Operation:
-			_out << " " << instructionInfo((Instruction)(byte)i.data()).name;
-			break;
-		case Push:
-			_out << " PUSH" << i.data();
-			break;
-		case PushString:
-			_out << " PUSH'[" << hex << (unsigned)i.data() << "]";
-			break;
-		case PushTag:
-			_out << " PUSH[tag" << i.data() << "]";
-			break;
-		case Tag:
-			_out << " tag" << i.data() << ": JUMPDEST";
-			break;
-		case PushData:
-			_out << " PUSH*[" << hex << (unsigned)i.data() << "]";
-			break;
-		case PushSub:
-			_out << " PUSHs[" << hex << h256(i.data()).abridged() << "]";
-			break;
-		case PushSubSize:
-			_out << " PUSHss[" << hex << h256(i.data()).abridged() << "]";
-			break;
-		case PushProgramSize:
-			_out << " PUSHSIZE";
-			break;
-		case NoOptimizeBegin:
-			_out << " DoNotOptimze{{";
-			break;
-		case NoOptimizeEnd:
-			_out << " DoNotOptimze}}";
-			break;
-		case UndefinedItem:
-			_out << " ???";
-			break;
-		default:
-			BOOST_THROW_EXCEPTION(InvalidOpcode());
-		}
+		_out << i;
 	return _out;
 }
 
@@ -219,7 +218,7 @@ ostream& Assembly::stream(ostream& _out, string const& _prefix, StringMap const&
 		switch (i.m_type)
 		{
 		case Operation:
-			_out << "  " << instructionInfo((Instruction)(byte)i.m_data).name  << "\t" << i.getJumpTypeAsString();
+			_out << "  " << instructionInfo(i.instruction()).name  << "\t" << i.getJumpTypeAsString();
 			break;
 		case Push:
 			_out << "  PUSH " << i.m_data;
@@ -245,12 +244,6 @@ ostream& Assembly::stream(ostream& _out, string const& _prefix, StringMap const&
 		case PushData:
 			_out << "  PUSH [" << hex << (unsigned)i.m_data << "]";
 			break;
-		case NoOptimizeBegin:
-			_out << "DoNotOptimze{{";
-			break;
-		case NoOptimizeEnd:
-			_out << "DoNotOptimze}}";
-			break;
 		default:
 			BOOST_THROW_EXCEPTION(InvalidOpcode());
 		}
@@ -384,7 +377,7 @@ Assembly& Assembly::optimise(bool _enable)
 					  {
 						  if (m[0].type() != Operation)
 							return m.toVector();
-						  Instruction instr = Instruction(byte(m[0].data()));
+						  Instruction instr = m[0].instruction();
 						  if (Instruction::DUP1 <= instr && instr <= Instruction::DUP16)
 							return {};
 						  InstructionInfo info = instructionInfo(instr);
@@ -424,12 +417,6 @@ Assembly& Assembly::optimise(bool _enable)
 		count = 0;
 		for (unsigned i = 0; i < m_items.size(); ++i)
 		{
-			if (m_items[i].type() == NoOptimizeBegin)
-			{
-				while (i < m_items.size() && m_items[i].type() != NoOptimizeEnd)
-					++i;
-				continue;
-			}
 			for (auto const& r: rules)
 			{
 				auto vr = AssemblyItemsConstRef(&m_items).cropped(i, r.first.size());
@@ -459,13 +446,11 @@ Assembly& Assembly::optimise(bool _enable)
 					}
 				}
 			}
-			if (m_items[i].type() == Operation && m_items[i].data() == (byte)Instruction::JUMP)
+			if (m_items[i].type() == Operation && m_items[i].instruction() == Instruction::JUMP)
 			{
 				bool o = false;
 				while (m_items.size() > i + 1 && m_items[i + 1].type() != Tag)
 				{
-					if (m_items[i + 1].type() == NoOptimizeBegin)
-						break;
 					m_items.erase(m_items.begin() + i + 1);
 					o = true;
 				}
@@ -490,7 +475,7 @@ Assembly& Assembly::optimise(bool _enable)
 		{
 			auto t = *tags.begin();
 			unsigned i = t.second;
-			if (i && m_items[i - 1].type() == Operation && m_items[i - 1].data() == (byte)Instruction::JUMP)
+			if (i && m_items[i - 1].type() == Operation && m_items[i - 1].instruction() == Instruction::JUMP)
 				while (i < m_items.size() && (m_items[i].type() != Tag || tags.count(m_items[i].data())))
 				{
 					if (m_items[i].type() == Tag && tags.count(m_items[i].data()))
@@ -599,9 +584,6 @@ bytes Assembly::assemble() const
 			tagPos[(unsigned)i.m_data] = ret.size();
 			ret.push_back((byte)Instruction::JUMPDEST);
 			break;
-		case NoOptimizeBegin:
-		case NoOptimizeEnd:
-			break;
 		default:
 			BOOST_THROW_EXCEPTION(InvalidOpcode());
 		}
diff --git a/libevmcore/Assembly.h b/libevmcore/Assembly.h
index 242f6f1ff..280a2e81c 100644
--- a/libevmcore/Assembly.h
+++ b/libevmcore/Assembly.h
@@ -24,6 +24,7 @@
 #include <iostream>
 #include <sstream>
 #include <libdevcore/Common.h>
+#include <libdevcore/Assertions.h>
 #include <libevmcore/SourceLocation.h>
 #include <libevmcore/Instruction.h>
 #include "Exceptions.h"
@@ -33,7 +34,7 @@ namespace dev
 namespace eth
 {
 
-enum AssemblyItemType { UndefinedItem, Operation, Push, PushString, PushTag, PushSub, PushSubSize, PushProgramSize, Tag, PushData, NoOptimizeBegin, NoOptimizeEnd };
+enum AssemblyItemType { UndefinedItem, Operation, Push, PushString, PushTag, PushSub, PushSubSize, PushProgramSize, Tag, PushData };
 
 class Assembly;
 
@@ -48,11 +49,17 @@ public:
 	AssemblyItem(Instruction _i): m_type(Operation), m_data((byte)_i) {}
 	AssemblyItem(AssemblyItemType _type, u256 _data = 0): m_type(_type), m_data(_data) {}
 
-	AssemblyItem tag() const { if (asserts(m_type == PushTag || m_type == Tag)) BOOST_THROW_EXCEPTION(Exception()); return AssemblyItem(Tag, m_data); }
-	AssemblyItem pushTag() const { if (asserts(m_type == PushTag || m_type == Tag)) BOOST_THROW_EXCEPTION(Exception()); return AssemblyItem(PushTag, m_data); }
+	AssemblyItem tag() const { assertThrow(m_type == PushTag || m_type == Tag, Exception, ""); return AssemblyItem(Tag, m_data); }
+	AssemblyItem pushTag() const { assertThrow(m_type == PushTag || m_type == Tag, Exception, ""); return AssemblyItem(PushTag, m_data); }
 
 	AssemblyItemType type() const { return m_type; }
-	u256 data() const { return m_data; }
+	u256 const& data() const { return m_data; }
+	/// @returns the instruction of this item (only valid if type() == Operation)
+	Instruction instruction() const { return Instruction(byte(m_data)); }
+
+	/// @returns true iff the type and data of the items are equal.
+	bool operator==(AssemblyItem const& _other) const { return m_type == _other.m_type && m_data == _other.m_data; }
+	bool operator!=(AssemblyItem const& _other) const { return !operator==(_other); }
 
 	/// @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.
@@ -77,6 +84,7 @@ private:
 using AssemblyItems = std::vector<AssemblyItem>;
 using AssemblyItemsConstRef = vector_ref<AssemblyItem const>;
 
+std::ostream& operator<<(std::ostream& _out, AssemblyItem const& _item);
 std::ostream& operator<<(std::ostream& _out, AssemblyItemsConstRef _i);
 inline std::ostream& operator<<(std::ostream& _out, AssemblyItems const& _i) { return operator<<(_out, AssemblyItemsConstRef(&_i)); }
 
diff --git a/libevmcore/Instruction.h b/libevmcore/Instruction.h
index 9eab92713..07c7b52fd 100644
--- a/libevmcore/Instruction.h
+++ b/libevmcore/Instruction.h
@@ -22,6 +22,7 @@
 #pragma once
 
 #include <libdevcore/Common.h>
+#include <libdevcore/Assertions.h>
 #include <libevmcore/Exceptions.h>
 
 namespace dev
@@ -194,32 +195,28 @@ inline unsigned getSwapNumber(Instruction _inst)
 /// @returns the PUSH<_number> instruction
 inline Instruction pushInstruction(unsigned _number)
 {
-	if (asserts(1 <= _number && _number <= 32))
-		BOOST_THROW_EXCEPTION(InvalidOpcode() << errinfo_comment("Invalid PUSH instruction requested."));
+	assertThrow(1 <= _number && _number <= 32, InvalidOpcode, "Invalid PUSH instruction requested.");
 	return Instruction(unsigned(Instruction::PUSH1) + _number - 1);
 }
 
 /// @returns the DUP<_number> instruction
 inline Instruction dupInstruction(unsigned _number)
 {
-	if (asserts(1 <= _number && _number <= 16))
-		BOOST_THROW_EXCEPTION(InvalidOpcode() << errinfo_comment("Invalid DUP instruction requested."));
+	assertThrow(1 <= _number && _number <= 16, InvalidOpcode, "Invalid DUP instruction requested.");
 	return Instruction(unsigned(Instruction::DUP1) + _number - 1);
 }
 
 /// @returns the SWAP<_number> instruction
 inline Instruction swapInstruction(unsigned _number)
 {
-	if (asserts(1 <= _number && _number <= 16))
-		BOOST_THROW_EXCEPTION(InvalidOpcode() << errinfo_comment("Invalid SWAP instruction requested."));
+	assertThrow(1 <= _number && _number <= 16, InvalidOpcode, "Invalid SWAP instruction requested.");
 	return Instruction(unsigned(Instruction::SWAP1) + _number - 1);
 }
 
 /// @returns the LOG<_number> instruction
 inline Instruction logInstruction(unsigned _number)
 {
-	if (asserts(_number <= 4))
-		BOOST_THROW_EXCEPTION(InvalidOpcode() << errinfo_comment("Invalid LOG instruction requested."));
+	assertThrow(_number <= 4, InvalidOpcode, "Invalid LOG instruction requested.");
 	return Instruction(unsigned(Instruction::LOG0) + _number);
 }
 
diff --git a/libp2p/Host.cpp b/libp2p/Host.cpp
index 1d54f4afe..78a8232fd 100644
--- a/libp2p/Host.cpp
+++ b/libp2p/Host.cpp
@@ -27,6 +27,7 @@
 #include <memory>
 #include <boost/algorithm/string.hpp>
 #include <libdevcore/Common.h>
+#include <libdevcore/Assertions.h>
 #include <libdevcore/CommonIO.h>
 #include <libdevcore/StructuredLogger.h>
 #include <libethcore/Exceptions.h>
diff --git a/libp2p/Network.cpp b/libp2p/Network.cpp
index d1e97fac6..bdd1f0108 100644
--- a/libp2p/Network.cpp
+++ b/libp2p/Network.cpp
@@ -29,6 +29,7 @@
 #include <boost/algorithm/string.hpp>
 
 #include <libdevcore/Common.h>
+#include <libdevcore/Assertions.h>
 #include <libdevcore/CommonIO.h>
 #include <libethcore/Exceptions.h>
 #include "Common.h"
diff --git a/libp2p/RLPxFrameIO.cpp b/libp2p/RLPxFrameIO.cpp
index cb768bfeb..ac1a27bed 100644
--- a/libp2p/RLPxFrameIO.cpp
+++ b/libp2p/RLPxFrameIO.cpp
@@ -19,11 +19,13 @@
  * @date 2015
  */
 
+#include "RLPxFrameIO.h"
+#include <libdevcore/Assertions.h>
 #include "Host.h"
 #include "Session.h"
 #include "Peer.h"
 #include "RLPxHandshake.h"
-#include "RLPxFrameIO.h"
+
 using namespace std;
 using namespace dev;
 using namespace dev::p2p;
diff --git a/libsolidity/Utils.h b/libsolidity/Utils.h
index 1411f66b4..05c5fa6f0 100644
--- a/libsolidity/Utils.h
+++ b/libsolidity/Utils.h
@@ -22,34 +22,9 @@
 
 #pragma once
 
-#include <string>
-#include <libsolidity/Exceptions.h>
-
-namespace dev
-{
-namespace solidity
-{
+#include <libdevcore/Assertions.h>
 
 /// Assertion that throws an InternalCompilerError containing the given description if it is not met.
 #define solAssert(CONDITION, DESCRIPTION) \
-	::dev::solidity::solAssertAux(CONDITION, DESCRIPTION, __LINE__, __FILE__, ETH_FUNC)
-
-inline void solAssertAux(bool _condition, std::string const& _errorDescription, unsigned _line,
-						 char const* _file, char const* _function)
-{
-	if (!_condition)
-		::boost::throw_exception( InternalCompilerError()
-				<< errinfo_comment(_errorDescription)
-				<< ::boost::throw_function(_function)
-				<< ::boost::throw_file(_file)
-				<< ::boost::throw_line(_line));
-}
-
-inline void solAssertAux(void const* _pointer, std::string const& _errorDescription, unsigned _line,
-						 char const* _file, char const* _function)
-{
-	solAssertAux(_pointer != nullptr, _errorDescription, _line, _file, _function);
-}
+	assertThrow(CONDITION, ::dev::solidity::InternalCompilerError, DESCRIPTION)
 
-}
-}
diff --git a/test/checkRandomStateTest.cpp b/test/checkRandomStateTest.cpp
index 17e785f60..8d73f872c 100644
--- a/test/checkRandomStateTest.cpp
+++ b/test/checkRandomStateTest.cpp
@@ -21,6 +21,7 @@
  */
 
 #include <libdevcore/Common.h>
+#include <libdevcore/Assertions.h>
 #include <libdevcore/Exceptions.h>
 #include <libdevcore/Log.h>
 #include <libevm/VMFactory.h>
diff --git a/test/checkRandomVMTest.cpp b/test/checkRandomVMTest.cpp
index c96357714..a40922577 100644
--- a/test/checkRandomVMTest.cpp
+++ b/test/checkRandomVMTest.cpp
@@ -21,6 +21,7 @@
  */
 
 #include <libdevcore/Common.h>
+#include <libdevcore/Assertions.h>
 #include <libdevcore/Exceptions.h>
 #include <libdevcore/Log.h>
 #include <libevm/VMFactory.h>
diff --git a/test/net.cpp b/test/net.cpp
index 831c283e2..3a69a627b 100644
--- a/test/net.cpp
+++ b/test/net.cpp
@@ -22,6 +22,7 @@
 #include <boost/test/unit_test.hpp>
 
 #include <libdevcore/Worker.h>
+#include <libdevcore/Assertions.h>
 #include <libdevcrypto/Common.h>
 #include <libp2p/UDP.h>
 #include <libp2p/NodeTable.h>