New Assembler.

8 files changed, 357 insertions, 404 deletions

diff --git a/Assembly.cpp b/Assembly.cpp
index a8491376..1f53cfb5 100644
--- a/Assembly.cpp
+++ b/Assembly.cpp
@@ -26,38 +26,201 @@
 using namespace std;
 using namespace eth;
 
+int AssemblyItem::deposit() const
+{
+	switch (m_type)
+	{
+	case Operation:
+		return c_instructionInfo.at((Instruction)(byte)m_data).ret - c_instructionInfo.at((Instruction)(byte)m_data).args;
+	case Push: case PushString: case PushTag: case PushData:
+		return 1;
+	case Tag:
+		return 0;
+	}
+	assert(false);
+}
+
+unsigned Assembly::bytesRequired() const
+{
+	for (unsigned br = 1;; ++br)
+	{
+		unsigned ret = 1;
+		for (auto const& i: m_data)
+			ret += i.second.size();
+
+		for (AssemblyItem const& i: m_items)
+			switch (i.m_type)
+			{
+			case Operation:
+				ret++;
+				break;
+			case PushString:
+				ret += 33;
+				break;
+			case Push:
+				ret += 1 + max<unsigned>(1, eth::bytesRequired(i.m_data));
+				break;
+			case PushTag:
+			case PushData:
+				ret += 1 + br;
+			case Tag:;
+			}
+		if (eth::bytesRequired(ret) <= br)
+			return ret;
+	}
+}
+
 void Assembly::append(Assembly const& _a)
 {
 	for (AssemblyItem i: _a.m_items)
 	{
 		if (i.type() == Tag || i.type() == PushTag)
 			i.m_data += m_usedTags;
-		m_items.push_back(i);
+		append(i);
 	}
+	m_usedTags += _a.m_usedTags;
 	for (auto const& i: _a.m_data)
 		m_data.insert(i);
+	for (auto const& i: _a.m_strings)
+		m_strings.insert(i);
+
+	assert(!_a.m_baseDeposit);
+	assert(!_a.m_totalDeposit);
+}
+
+void Assembly::append(Assembly const& _a, int _deposit)
+{
+	if (_deposit > _a.m_deposit)
+		throw InvalidDeposit();
+	else
+	{
+		append(_a);
+		while (_deposit++ < _a.m_deposit)
+			append(Instruction::POP);
+	}
 }
 
 ostream& Assembly::streamOut(ostream& _out) const
 {
+	_out << ".code:" << endl;
 	for (AssemblyItem const& i: m_items)
 		switch (i.m_type)
 		{
 		case Operation:
-			_out << c_instructionInfo.at((Instruction)(byte)i.m_data).name << endl;
+			_out << "  " << c_instructionInfo.at((Instruction)(byte)i.m_data).name << endl;
 			break;
 		case Push:
-			_out << i.m_data << endl;
+			_out << "  PUSH " << i.m_data << endl;
+			break;
+		case PushString:
+			_out << "  PUSH \"" << m_strings.at((h256)i.m_data) << "\"" << endl;
+			break;
+		case PushTag:
+			_out << "  PUSH [tag" << i.m_data << "]" << endl;
+			break;
+		case Tag:
+			_out << "tag" << i.m_data << ": " << endl;
+			break;
+		case PushData:
+			_out << "  PUSH [" << h256(i.m_data).abridged() << "]" << endl;
 			break;
-/*		case PushString:
-			_out << i.m_data << endl;
-			break;*/
 		}
+
+	if (m_data.size())
+	{
+		_out << ".data:" << endl;
+		for (auto const& i: m_data)
+			_out << "  " << i.first.abridged() << ": " << toHex(i.second) << endl;
+	}
 	return _out;
 }
 
+AssemblyItem const& Assembly::append(AssemblyItem const& _i)
+{
+	m_deposit += _i.deposit();
+	m_items.push_back(_i);
+	return back();
+}
+
 bytes Assembly::assemble() const
 {
 	bytes ret;
+
+	unsigned totalBytes = bytesRequired();
+	ret.reserve(totalBytes);
+	vector<unsigned> tagPos(m_usedTags);
+	map<unsigned, unsigned> tagRef;
+	multimap<h256, unsigned> dataRef;
+	unsigned bytesPerTag = eth::bytesRequired(totalBytes);
+	byte tagPush = (byte)Instruction::PUSH1 - 1 + bytesPerTag;
+
+	for (AssemblyItem const& i: m_items)
+		switch (i.m_type)
+		{
+		case Operation:
+			ret.push_back((byte)i.m_data);
+			break;
+		case PushString:
+		{
+			ret.push_back((byte)Instruction::PUSH32);
+			unsigned ii = 0;
+			for (auto j: m_strings.at((h256)i.m_data))
+				if (++ii > 32)
+					break;
+				else
+					ret.push_back((byte)j);
+			while (ii++ < 32)
+				ret.push_back(0);
+			break;
+		}
+		case Push:
+		{
+			byte b = max<unsigned>(1, eth::bytesRequired(i.m_data));
+			ret.push_back((byte)Instruction::PUSH1 - 1 + b);
+			ret.resize(ret.size() + b);
+			bytesRef byr(&ret.back() + 1 - b, b);
+			toBigEndian(i.m_data, byr);
+			break;
+		}
+		case PushTag:
+		{
+			ret.push_back(tagPush);
+			tagRef[ret.size()] = (unsigned)i.m_data;
+			ret.resize(ret.size() + bytesPerTag);
+			break;
+		}
+		case PushData:
+		{
+			ret.push_back(tagPush);
+			dataRef.insert(make_pair((h256)i.m_data, ret.size()));
+			ret.resize(ret.size() + bytesPerTag);
+			break;
+		}
+		case Tag:
+			tagPos[(unsigned)i.m_data] = ret.size();
+			break;
+		}
+
+	for (auto const& i: tagRef)
+	{
+		bytesRef r(ret.data() + i.first, bytesPerTag);
+		toBigEndian(tagPos[i.second], r);
+	}
+
+	if (m_data.size())
+	{
+		ret.push_back(0);
+		for (auto const& i: m_data)
+		{
+			auto its = dataRef.equal_range(i.first);
+			for (auto it = its.first; it != its.second; ++it)
+			{
+				bytesRef r(ret.data() + it->second, bytesPerTag);
+				toBigEndian(ret.size(), r);
+			}
+			for (auto b: i.second)
+				ret.push_back(b);
+		}
+	}
 	return ret;
 }
diff --git a/Assembly.h b/Assembly.h
index ca3beaf5..86b37622 100644
--- a/Assembly.h
+++ b/Assembly.h
@@ -22,6 +22,7 @@
 #pragma once
 
 #include <iostream>
+#include <sstream>
 #include <libethsupport/Common.h>
 #include <libethcore/Instruction.h>
 #include "Exceptions.h"
@@ -39,14 +40,16 @@ class AssemblyItem
 
 public:
 	AssemblyItem(u256 _push): m_type(Push), m_data(_push) {}
-	AssemblyItem(AssemblyItemType _type, AssemblyItem const& _tag): m_type(_type), m_data(_tag.m_data) { assert(_type == PushTag); assert(_tag.m_type == Tag); }
 	AssemblyItem(Instruction _i): m_type(Operation), m_data((byte)_i) {}
 	AssemblyItem(AssemblyItemType _type, u256 _data): m_type(_type), m_data(_data) {}
 
+	AssemblyItem tag() const { assert(m_type == PushTag || m_type == Tag); return AssemblyItem(Tag, m_data); }
+	AssemblyItem pushTag() const { assert(m_type == PushTag || m_type == Tag); return AssemblyItem(PushTag, m_data); }
+
 	AssemblyItemType type() const { return m_type; }
 	u256 data() const { return m_data; }
 
-	std::ostream& streamOut(std::ostream& _out) const;
+	int deposit() const;
 
 private:
 	AssemblyItemType m_type;
@@ -57,19 +60,58 @@ class Assembly
 {
 public:
 	AssemblyItem newTag() { return AssemblyItem(Tag, m_usedTags++); }
+	AssemblyItem newPushTag() { return AssemblyItem(PushTag, m_usedTags++); }
 	AssemblyItem newData(bytes const& _data) { auto h = sha3(_data); m_data[h] = _data; return AssemblyItem(PushData, h); }
-	AssemblyItem newPushString(std::string const& _data) { auto b = asBytes(_data); auto h = sha3(b); m_data[h] = b; return AssemblyItem(PushString, h); }
+	AssemblyItem newPushString(std::string const& _data) { auto h = sha3(_data); m_strings[h] = _data; return AssemblyItem(PushString, h); }
+
+	AssemblyItem append() { return append(newTag()); }
+	void append(Assembly const& _a);
+	void append(Assembly const& _a, int _deposit);
+	AssemblyItem const& append(AssemblyItem const& _i);
+	AssemblyItem const& append(std::string const& _data) { return append(newPushString(_data)); }
+	AssemblyItem const& append(bytes const& _data) { return append(newData(_data)); }
+
+	AssemblyItem appendJump() { auto ret = append(newPushTag()); append(Instruction::JUMP); return ret; }
+	AssemblyItem appendJumpI() { auto ret = append(newPushTag()); append(Instruction::JUMPI); return ret; }
+	AssemblyItem appendJump(AssemblyItem const& _tag) { auto ret = append(_tag.pushTag()); append(Instruction::JUMP); return ret; }
+	AssemblyItem appendJumpI(AssemblyItem const& _tag) { auto ret = append(_tag.pushTag()); append(Instruction::JUMPI); return ret; }
+
+	template <class T> Assembly& operator<<(T const& _d) { append(_d); return *this; }
+
+	AssemblyItem const& back() { return m_items.back(); }
+	std::string backString() const { return m_items.back().m_type == PushString ? m_strings.at((h256)m_items.back().m_data) : std::string(); }
 
-	void append(AssemblyItem const& _i) { m_items.push_back(_i); }
+	void onePath() { assert(!m_totalDeposit && !m_baseDeposit); m_baseDeposit = m_deposit; m_totalDeposit = INT_MAX; }
+	void otherPath() { donePath(); m_totalDeposit = m_deposit; m_deposit = m_baseDeposit; }
+	void donePaths() { donePath(); m_totalDeposit = m_baseDeposit = 0; }
+	void ignored() { m_baseDeposit = m_deposit; }
+	void endIgnored() { m_deposit = m_baseDeposit; m_baseDeposit = 0; }
 
+	void popTo(int _deposit) { while (m_deposit > _deposit) append(Instruction::POP); }
+
+	std::string out() const { std::stringstream ret; streamOut(ret); return ret.str(); }
+	int deposit() const { return m_deposit; }
 	bytes assemble() const;
-	void append(Assembly const& _a);
 	std::ostream& streamOut(std::ostream& _out) const;
 
 private:
-	u256 m_usedTags = 0;
+	void donePath() { if (m_totalDeposit != INT_MAX && m_totalDeposit != m_deposit) throw InvalidDeposit(); }
+	unsigned bytesRequired() const;
+
+	unsigned m_usedTags = 0;
 	std::vector<AssemblyItem> m_items;
 	std::map<h256, bytes> m_data;
+	std::map<h256, std::string> m_strings;
+
+	int m_deposit = 0;
+	int m_baseDeposit = 0;
+	int m_totalDeposit = 0;
 };
 
+inline std::ostream& operator<<(std::ostream& _out, Assembly const& _a)
+{
+	_a.streamOut(_out);
+	return _out;
+}
+
 }
diff --git a/CodeFragment.cpp b/CodeFragment.cpp
index c4b7ae0b..59ff729e 100644
--- a/CodeFragment.cpp
+++ b/CodeFragment.cpp
@@ -34,100 +34,6 @@ namespace qi = boost::spirit::qi;
 namespace px = boost::phoenix;
 namespace sp = boost::spirit;
 
-void CodeFragment::appendFragment(CodeFragment const& _f)
-{
-	m_locs.reserve(m_locs.size() + _f.m_locs.size());
-	m_code.reserve(m_code.size() + _f.m_code.size());
-
-	unsigned os = m_code.size();
-
-	for (auto i: _f.m_code)
-		m_code.push_back(i);
-
-	for (auto i: _f.m_locs)
-	{
-		CodeLocation(this, i + os).increase(os);
-		m_locs.push_back(i + os);
-	}
-
-	for (auto i: _f.m_data)
-		m_data.insert(make_pair(i.first, i.second + os));
-
-	m_deposit += _f.m_deposit;
-}
-
-CodeFragment CodeFragment::compile(string const& _src, CompilerState& _s)
-{
-	CodeFragment ret;
-	sp::utree o;
-	parseTreeLLL(_src, o);
-	if (!o.empty())
-		ret = CodeFragment(o, _s);
-	_s.treesToKill.push_back(o);
-	return ret;
-}
-
-void CodeFragment::consolidateData()
-{
-	m_code.push_back(0);
-	bytes ld;
-	for (auto const& i: m_data)
-	{
-		if (ld != i.first)
-		{
-			ld = i.first;
-			for (auto j: ld)
-				m_code.push_back(j);
-		}
-		CodeLocation(this, i.second).set(m_code.size() - ld.size());
-	}
-	m_data.clear();
-}
-
-void CodeFragment::appendFragment(CodeFragment const& _f, unsigned _deposit)
-{
-	if ((int)_deposit > _f.m_deposit)
-		error<InvalidDeposit>();
-	else
-	{
-		appendFragment(_f);
-		while (_deposit++ < (unsigned)_f.m_deposit)
-			appendInstruction(Instruction::POP);
-	}
-}
-
-CodeLocation CodeFragment::appendPushLocation(unsigned _locationValue)
-{
-	m_code.push_back((byte)Instruction::PUSH4);
-	CodeLocation ret(this, m_code.size());
-	m_locs.push_back(m_code.size());
-	m_code.resize(m_code.size() + 4);
-	bytesRef r(&m_code[m_code.size() - 4], 4);
-	toBigEndian(_locationValue, r);
-	m_deposit++;
-	return ret;
-}
-
-unsigned CodeFragment::appendPush(u256 _literalValue)
-{
-	unsigned br = max<unsigned>(1, bytesRequired(_literalValue));
-	m_code.push_back((byte)Instruction::PUSH1 + br - 1);
-	m_code.resize(m_code.size() + br);
-	for (unsigned i = 0; i < br; ++i)
-	{
-		m_code[m_code.size() - 1 - i] = (byte)(_literalValue & 0xff);
-		_literalValue >>= 8;
-	}
-	m_deposit++;
-	return br + 1;
-}
-
-void CodeFragment::appendInstruction(Instruction _i)
-{
-	m_code.push_back((byte)_i);
-	m_deposit += c_instructionInfo.at(_i).ret - c_instructionInfo.at(_i).args;
-}
-
 CodeFragment::CodeFragment(sp::utree const& _t, CompilerState& _s, bool _allowASM)
 {
 /*	cdebug << "CodeFragment. Locals:";
@@ -151,12 +57,7 @@ CodeFragment::CodeFragment(sp::utree const& _t, CompilerState& _s, bool _allowAS
 	{
 		auto sr = _t.get<sp::basic_string<boost::iterator_range<char const*>, sp::utree_type::string_type>>();
 		string s(sr.begin(), sr.end());
-		if (s.size() > 32)
-			error<StringTooLong>();
-		h256 valHash;
-		memcpy(valHash.data(), s.data(), s.size());
-		memset(valHash.data() + s.size(), 0, 32 - s.size());
-		appendPush(valHash);
+		m_asm.append(s);
 		break;
 	}
 	case sp::utree_type::symbol_type:
@@ -164,21 +65,14 @@ CodeFragment::CodeFragment(sp::utree const& _t, CompilerState& _s, bool _allowAS
 		auto sr = _t.get<sp::basic_string<boost::iterator_range<char const*>, sp::utree_type::symbol_type>>();
 		string s(sr.begin(), sr.end());
 		string us = boost::algorithm::to_upper_copy(s);
-		if (_allowASM)
-		{
-			if (c_instructions.count(us))
-			{
-				auto it = c_instructions.find(us);
-				m_deposit = c_instructionInfo.at(it->second).ret - c_instructionInfo.at(it->second).args;
-				m_code.push_back((byte)it->second);
-			}
-		}
+		if (_allowASM && c_instructions.count(us))
+			m_asm.append(c_instructions.at(us));
 		if (_s.defs.count(s))
-			appendFragment(_s.defs.at(s));
+			m_asm.append(_s.defs.at(s).m_asm);
 		else if (_s.args.count(s))
-			appendFragment(_s.args.at(s));
+			m_asm.append(_s.args.at(s).m_asm);
 		else if (_s.outers.count(s))
-			appendFragment(_s.outers.at(s));
+			m_asm.append(_s.outers.at(s).m_asm);
 		else if (us.find_first_of("1234567890") != 0 && us.find_first_not_of("QWERTYUIOPASDFGHJKLZXCVBNM1234567890_") == string::npos)
 		{
 			auto it = _s.vars.find(s);
@@ -187,7 +81,7 @@ CodeFragment::CodeFragment(sp::utree const& _t, CompilerState& _s, bool _allowAS
 				bool ok;
 				tie(it, ok) = _s.vars.insert(make_pair(s, _s.vars.size() * 32));
 			}
-			appendPush(it->second);
+			m_asm.append((u256)it->second);
 		}
 		else
 			error<BareSymbol>();
@@ -199,44 +93,13 @@ CodeFragment::CodeFragment(sp::utree const& _t, CompilerState& _s, bool _allowAS
 		bigint i = *_t.get<bigint*>();
 		if (i < 0 || i > bigint(u256(0) - 1))
 			error<IntegerOutOfRange>();
-		appendPush((u256)i);
+		m_asm.append((u256)i);
 		break;
 	}
 	default: break;
 	}
 }
 
-void CodeFragment::appendPushDataLocation(bytes const& _data)
-{
-	m_code.push_back((byte)Instruction::PUSH4);
-	m_data.insert(make_pair(_data, m_code.size()));
-	m_code.resize(m_code.size() + 4);
-	memset(&m_code.back() - 3, 0, 4);
-	m_deposit++;
-}
-
-std::string CodeFragment::asPushedString() const
-{
-	string ret;
-	if (m_code.size())
-	{
-		unsigned bc = m_code[0] - (byte)Instruction::PUSH1 + 1;
-		if (m_code[0] >= (byte)Instruction::PUSH1 && m_code[0] <= (byte)Instruction::PUSH32)
-		{
-			for (unsigned s = 0; s < bc && m_code[1 + s]; ++s)
-				ret.push_back(m_code[1 + s]);
-			return ret;
-		}
-	}
-	error<ExpectedLiteral>();
-	return ret;
-}
-
-void CodeFragment::optimise()
-{
-//	map<string, function<bytes(vector<u256> const&)>> pattern = { { "PUSH,PUSH,ADD", [](vector<u256> const& v) { return CodeFragment(appendPush(v[0] + v[1])); } } };
-}
-
 void CodeFragment::constructOperation(sp::utree const& _t, CompilerState& _s)
 {
 	if (_t.empty())
@@ -281,7 +144,7 @@ void CodeFragment::constructOperation(sp::utree const& _t, CompilerState& _s)
 			int c = 0;
 			for (auto const& i: _t)
 				if (c++)
-					appendFragment(CodeFragment(i, _s, true));
+					m_asm.append(CodeFragment(i, _s, true).m_asm);
 		}
 		else if (us == "INCLUDE")
 		{
@@ -299,9 +162,9 @@ void CodeFragment::constructOperation(sp::utree const& _t, CompilerState& _s)
 			else if (i.which() == sp::utree_type::symbol_type)
 			{
 				auto sr = i.get<sp::basic_string<boost::iterator_range<char const*>, sp::utree_type::symbol_type>>();
-				n = _s.getDef(string(sr.begin(), sr.end())).asPushedString();
+				n = _s.getDef(string(sr.begin(), sr.end())).m_asm.backString();
 			}
-			appendFragment(CodeFragment::compile(asString(contents(n)), _s));
+			m_asm.append(CodeFragment::compile(asString(contents(n)), _s).m_asm);
 		}
 		else if (us == "DEF")
 		{
@@ -323,7 +186,7 @@ void CodeFragment::constructOperation(sp::utree const& _t, CompilerState& _s)
 					else if (i.which() == sp::utree_type::symbol_type)
 					{
 						auto sr = i.get<sp::basic_string<boost::iterator_range<char const*>, sp::utree_type::symbol_type>>();
-						n = _s.getDef(string(sr.begin(), sr.end())).asPushedString();
+						n = _s.getDef(string(sr.begin(), sr.end())).m_asm.backString();
 					}
 				}
 				else if (ii == 2)
@@ -362,7 +225,7 @@ void CodeFragment::constructOperation(sp::utree const& _t, CompilerState& _s)
 				if (ii == 1)
 				{
 					pos = CodeFragment(i, _s);
-					if (pos.m_deposit != 1)
+					if (pos.m_asm.deposit() != 1)
 						error<InvalidDeposit>();
 				}
 				else if (ii == 2 && !i.tag() && i.which() == sp::utree_type::string_type)
@@ -396,11 +259,11 @@ void CodeFragment::constructOperation(sp::utree const& _t, CompilerState& _s)
 					error<InvalidLiteral>();
 				++ii;
 			}
-			appendPush(data.size());
-			appendInstruction(Instruction::DUP);
-			appendPushDataLocation(data);
-			appendFragment(pos, 1);
-			appendInstruction(Instruction::CODECOPY);
+			m_asm.append((u256)data.size());
+			m_asm.append(Instruction::DUP);
+			m_asm.append(data);
+			m_asm.append(pos.m_asm, 1);
+			m_asm.append(Instruction::CODECOPY);
 		}
 		else
 			nonStandard = false;
@@ -427,7 +290,7 @@ void CodeFragment::constructOperation(sp::utree const& _t, CompilerState& _s)
 		auto requireSize = [&](unsigned s) { if (code.size() != s) error<IncorrectParameterCount>(); };
 		auto requireMinSize = [&](unsigned s) { if (code.size() < s) error<IncorrectParameterCount>(); };
 		auto requireMaxSize = [&](unsigned s) { if (code.size() > s) error<IncorrectParameterCount>(); };
-		auto requireDeposit = [&](unsigned i, int s) { if (code[i].m_deposit != s) error<InvalidDeposit>(); };
+		auto requireDeposit = [&](unsigned i, int s) { if (code[i].m_asm.deposit() != s) error<InvalidDeposit>(); };
 
 		if (_s.macros.count(s) && _s.macros.at(s).args.size() == code.size())
 		{
@@ -443,7 +306,7 @@ void CodeFragment::constructOperation(sp::utree const& _t, CompilerState& _s)
 				requireDeposit(i, 1);
 				cs.args[m.args[i]] = code[i];
 			}
-			appendFragment(CodeFragment(m.code, cs));
+			m_asm.append(CodeFragment(m.code, cs).m_asm);
 			for (auto const& i: cs.defs)
 				_s.defs[i.first] = i.second;
 			for (auto const& i: cs.macros)
@@ -459,8 +322,8 @@ void CodeFragment::constructOperation(sp::utree const& _t, CompilerState& _s)
 				requireMinSize(-ea);
 
 			for (unsigned i = code.size(); i; --i)
-				appendFragment(code[i - 1], 1);
-			appendInstruction(it->second);
+				m_asm.append(code[i - 1].m_asm, 1);
+			m_asm.append(it->second);
 		}
 		else if (c_arith.count(us))
 		{
@@ -469,10 +332,10 @@ void CodeFragment::constructOperation(sp::utree const& _t, CompilerState& _s)
 			for (unsigned i = code.size(); i; --i)
 			{
 				requireDeposit(i - 1, 1);
-				appendFragment(code[i - 1], 1);
+				m_asm.append(code[i - 1].m_asm, 1);
 			}
 			for (unsigned i = 1; i < code.size(); ++i)
-				appendInstruction(it->second);
+				m_asm.append(it->second);
 		}
 		else if (c_binary.count(us))
 		{
@@ -480,74 +343,75 @@ void CodeFragment::constructOperation(sp::utree const& _t, CompilerState& _s)
 			requireSize(2);
 			requireDeposit(0, 1);
 			requireDeposit(1, 1);
-			appendFragment(code[1], 1);
-			appendFragment(code[0], 1);
-			appendInstruction(it->second.first);
+			m_asm.append(code[1].m_asm, 1);
+			m_asm.append(code[0].m_asm, 1);
+			m_asm.append(it->second.first);
 			if (it->second.second)
-				appendInstruction(Instruction::NOT);
+				m_asm.append(Instruction::NOT);
 		}
 		else if (c_unary.count(us))
 		{
 			auto it = c_unary.find(us);
 			requireSize(1);
 			requireDeposit(0, 1);
-			appendFragment(code[0], 1);
-			appendInstruction(it->second);
+			m_asm.append(code[0].m_asm, 1);
+			m_asm.append(it->second);
 		}
 		else if (us == "IF")
 		{
 			requireSize(3);
 			requireDeposit(0, 1);
-			appendFragment(code[0]);
-			auto pos = appendJumpI();
-			onePath();
-			appendFragment(code[2]);
-			auto end = appendJump();
-			otherPath();
-			pos.anchor();
-			appendFragment(code[1]);
-			donePaths();
-			end.anchor();
+
+			m_asm.append(code[0].m_asm);
+			auto pos = m_asm.appendJumpI();
+			m_asm.onePath();
+			m_asm << code[2].m_asm;
+			auto end = m_asm.appendJump();
+			m_asm.otherPath();
+			m_asm << pos.tag() << code[1].m_asm << end.tag();
+			m_asm.donePaths();
 		}
 		else if (us == "WHEN" || us == "UNLESS")
 		{
 			requireSize(2);
 			requireDeposit(0, 1);
-			appendFragment(code[0]);
+
+			m_asm.append(code[0].m_asm);
 			if (us == "WHEN")
-				appendInstruction(Instruction::NOT);
-			auto end = appendJumpI();
-			onePath();
-			otherPath();
-			appendFragment(code[1], 0);
-			donePaths();
-			end.anchor();
+				m_asm.append(Instruction::NOT);
+			auto end = m_asm.appendJumpI();
+			m_asm.onePath();
+			m_asm.otherPath();
+			m_asm << code[1].m_asm << end.tag();
+			m_asm.donePaths();
 		}
 		else if (us == "WHILE")
 		{
 			requireSize(2);
 			requireDeposit(0, 1);
-			auto begin = CodeLocation(this);
-			appendFragment(code[0], 1);
-			appendInstruction(Instruction::NOT);
-			auto end = appendJumpI();
-			appendFragment(code[1], 0);
-			appendJump(begin);
-			end.anchor();
+
+			auto begin = m_asm.append();
+			m_asm.append(code[0].m_asm);
+			m_asm.append(Instruction::NOT);
+			auto end = m_asm.appendJumpI();
+			m_asm.append(code[1].m_asm, 0);
+			m_asm.appendJump(begin);
+			m_asm << end.tag();
 		}
 		else if (us == "FOR")
 		{
 			requireSize(4);
 			requireDeposit(1, 1);
-			appendFragment(code[0], 0);
-			auto begin = CodeLocation(this);
-			appendFragment(code[1], 1);
-			appendInstruction(Instruction::NOT);
-			auto end = appendJumpI();
-			appendFragment(code[3], 0);
-			appendFragment(code[2], 0);
-			appendJump(begin);
-			end.anchor();
+
+			m_asm.append(code[0].m_asm, 0);
+			auto begin = m_asm.append();
+			m_asm.append(code[1].m_asm);
+			m_asm.append(Instruction::NOT);
+			auto end = m_asm.appendJumpI();
+			m_asm.append(code[3].m_asm, 0);
+			m_asm.append(code[2].m_asm, 0);
+			m_asm.appendJump(begin);
+			m_asm << end.tag();
 		}
 		else if (us == "LLL")
 		{
@@ -555,22 +419,22 @@ void CodeFragment::constructOperation(sp::utree const& _t, CompilerState& _s)
 			requireMaxSize(3);
 			requireDeposit(1, 1);
 
-			CodeLocation codeloc(this, m_code.size() + 6);
 			bytes const& subcode = code[0].code();
-			appendPush(subcode.size());
-			appendInstruction(Instruction::DUP);
+
+			m_asm.append((u256)subcode.size());
+			m_asm.append(Instruction::DUP);
 			if (code.size() == 3)
 			{
 				requireDeposit(2, 1);
-				appendFragment(code[2], 1);
-				appendInstruction(Instruction::LT);
-				appendInstruction(Instruction::NOT);
-				appendInstruction(Instruction::MUL);
-				appendInstruction(Instruction::DUP);
+				m_asm.append(code[2].m_asm, 1);
+				m_asm.append(Instruction::LT);
+				m_asm.append(Instruction::NOT);
+				m_asm.append(Instruction::MUL);
+				m_asm.append(Instruction::DUP);
 			}
-			appendPushDataLocation(subcode);
-			appendFragment(code[1], 1);
-			appendInstruction(Instruction::CODECOPY);
+			m_asm.append(subcode);
+			m_asm.append(code[1].m_asm, 1);
+			m_asm.append(Instruction::CODECOPY);
 		}
 		else if (us == "&&" || us == "||")
 		{
@@ -578,53 +442,52 @@ void CodeFragment::constructOperation(sp::utree const& _t, CompilerState& _s)
 			for (unsigned i = 0; i < code.size(); ++i)
 				requireDeposit(i, 1);
 
-			vector<CodeLocation> ends;
+			auto end = m_asm.newTag();
 			if (code.size() > 1)
 			{
-				appendPush(us == "||" ? 1 : 0);
+				m_asm.append((u256)(us == "||" ? 1 : 0));
 				for (unsigned i = 1; i < code.size(); ++i)
 				{
 					// Check if true - predicate
-					appendFragment(code[i - 1], 1);
+					m_asm.append(code[i - 1].m_asm, 1);
 					if (us == "&&")
-						appendInstruction(Instruction::NOT);
-					ends.push_back(appendJumpI());
+						m_asm.append(Instruction::NOT);
+					m_asm.appendJumpI(end);
 				}
-				appendInstruction(Instruction::POP);
+				m_asm.append(Instruction::POP);
 			}
 
 			// Check if true - predicate
-			appendFragment(code.back(), 1);
+			m_asm.append(code.back().m_asm, 1);
 
 			// At end now.
-			for (auto& i: ends)
-				i.anchor();
+			m_asm.append(end);
 		}
 		else if (us == "~")
 		{
 			requireSize(1);
 			requireDeposit(0, 1);
-			appendFragment(code[0], 1);
-			appendPush(1);
-			appendPush(0);
-			appendInstruction(Instruction::SUB);
-			appendInstruction(Instruction::SUB);
+
+			m_asm.append(code[0].m_asm, 1);
+			m_asm.append((u256)1);
+			m_asm.append((u256)0);
+			m_asm.append(Instruction::SUB);
+			m_asm.append(Instruction::SUB);
 		}
 		else if (us == "SEQ")
 		{
 			unsigned ii = 0;
 			for (auto const& i: code)
 				if (++ii < code.size())
-					appendFragment(i, 0);
+					m_asm.append(i.m_asm, 0);
 				else
-					appendFragment(i);
+					m_asm.append(i.m_asm);
 		}
 		else if (us == "RAW")
 		{
 			for (auto const& i: code)
-				appendFragment(i);
-			while (m_deposit > 1)
-				appendInstruction(Instruction::POP);
+				m_asm.append(i.m_asm);
+			m_asm.popTo(1);
 		}
 		else if (us.find_first_of("1234567890") != 0 && us.find_first_not_of("QWERTYUIOPASDFGHJKLZXCVBNM1234567890_") == string::npos)
 		{
@@ -634,9 +497,20 @@ void CodeFragment::constructOperation(sp::utree const& _t, CompilerState& _s)
 				bool ok;
 				tie(it, ok) = _s.vars.insert(make_pair(s, _s.vars.size() * 32));
 			}
-			appendPush(it->second);
+			m_asm.append((u256)it->second);
 		}
 		else
 			error<InvalidOperation>();
 	}
 }
+
+CodeFragment CodeFragment::compile(string const& _src, CompilerState& _s)
+{
+	CodeFragment ret;
+	sp::utree o;
+	parseTreeLLL(_src, o);
+	if (!o.empty())
+		ret = CodeFragment(o, _s);
+	_s.treesToKill.push_back(o);
+	return ret;
+}
diff --git a/CodeFragment.h b/CodeFragment.h
index 9f312cda..64760484 100644
--- a/CodeFragment.h
+++ b/CodeFragment.h
@@ -23,7 +23,7 @@
 
 #include <libethsupport/Common.h>
 #include <libethcore/Instruction.h>
-#include "CodeLocation.h"
+#include "Assembly.h"
 #include "Exceptions.h"
 
 namespace boost { namespace spirit { class utree; } }
@@ -36,60 +36,23 @@ class CompilerState;
 
 class CodeFragment
 {
-	friend class CodeLocation;
-
 public:
+	CodeFragment() {}
 	CodeFragment(sp::utree const& _t, CompilerState& _s, bool _allowASM = false);
-	CodeFragment(bytes const& _c = bytes()): m_code(_c) {}
 
 	static CodeFragment compile(std::string const& _src, CompilerState& _s);
 
-	/// Consolidates data and returns code.
-	bytes const& code() { optimise(); consolidateData(); return m_code; }
-
-	unsigned appendPush(u256 _l);
-	void appendFragment(CodeFragment const& _f);
-	void appendFragment(CodeFragment const& _f, unsigned _i);
-	void appendInstruction(Instruction _i);
-
-	CodeLocation appendPushLocation(unsigned _l = 0);
-	void appendPushLocation(CodeLocation _l) { assert(_l.m_f == this); appendPushLocation(_l.m_pos); }
-	void appendPushDataLocation(bytes const& _data);
-
-	CodeLocation appendJump() { auto ret = appendPushLocation(0); appendInstruction(Instruction::JUMP); return ret; }
-	CodeLocation appendJumpI() { auto ret = appendPushLocation(0); appendInstruction(Instruction::JUMPI); return ret; }
-	CodeLocation appendJump(CodeLocation _l) { auto ret = appendPushLocation(_l.m_pos); appendInstruction(Instruction::JUMP); return ret; }
-	CodeLocation appendJumpI(CodeLocation _l) { auto ret = appendPushLocation(_l.m_pos); appendInstruction(Instruction::JUMPI); return ret; }
-
-	void appendFile(std::string const& _fn);
+	/// Consolidates data and compiles code.
+	bytes code() const { return m_asm.assemble(); }
 
-	std::string asPushedString() const;
-
-	void onePath() { assert(!m_totalDeposit && !m_baseDeposit); m_baseDeposit = m_deposit; m_totalDeposit = INT_MAX; }
-	void otherPath() { donePath(); m_totalDeposit = m_deposit; m_deposit = m_baseDeposit; }
-	void donePaths() { donePath(); m_totalDeposit = m_baseDeposit = 0; }
-	void ignored() { m_baseDeposit = m_deposit; }
-	void endIgnored() { m_deposit = m_baseDeposit; m_baseDeposit = 0; }
-
-	bool operator==(CodeFragment const& _f) const { return _f.m_code == m_code && _f.m_data == m_data; }
-	bool operator!=(CodeFragment const& _f) const { return !operator==(_f); }
-	unsigned size() const { return m_code.size(); }
-
-	void consolidateData();
-	void optimise();
+	/// Consolidates data and compiles code.
+	std::string assembly() const { return m_asm.out(); }
 
 private:
 	template <class T> void error() const { throw T(); }
 	void constructOperation(sp::utree const& _t, CompilerState& _s);
 
-	void donePath() { if (m_totalDeposit != INT_MAX && m_totalDeposit != m_deposit) error<InvalidDeposit>(); }
-
-	int m_deposit = 0;
-	int m_baseDeposit = 0;
-	int m_totalDeposit = 0;
-	bytes m_code;
-	std::vector<unsigned> m_locs;
-	std::multimap<bytes, unsigned> m_data;
+	Assembly m_asm;
 };
 
 static const CodeFragment NullCodeFragment;
diff --git a/CodeLocation.cpp b/CodeLocation.cpp
deleted file mode 100644
index 2c9ca264..00000000
--- a/CodeLocation.cpp
+++ /dev/null
@@ -1,59 +0,0 @@
-/*
-	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 CodeLocation.cpp
- * @author Gav Wood <i@gavwood.com>
- * @date 2014
- */
-
-#include "CodeLocation.h"
-#include "CodeFragment.h"
-using namespace std;
-using namespace eth;
-
-CodeLocation::CodeLocation(CodeFragment* _f)
-{
-	m_f = _f;
-	m_pos = _f->m_code.size();
-}
-
-unsigned CodeLocation::get() const
-{
-	assert(m_f->m_code[m_pos - 1] == (byte)Instruction::PUSH4);
-	bytesConstRef r(&m_f->m_code[m_pos], 4);
-	return fromBigEndian<uint32_t>(r);
-}
-
-void CodeLocation::set(unsigned _val)
-{
-	assert(m_f->m_code[m_pos - 1] == (byte)Instruction::PUSH4);
-	assert(!get());
-	bytesRef r(&m_f->m_code[m_pos], 4);
-	toBigEndian(_val, r);
-}
-
-void CodeLocation::anchor()
-{
-	set(m_f->m_code.size());
-}
-
-void CodeLocation::increase(unsigned _val)
-{
-	assert(m_f->m_code[m_pos - 1] == (byte)Instruction::PUSH4);
-	bytesRef r(&m_f->m_code[m_pos], 4);
-	toBigEndian(get() + _val, r);
-}
-
diff --git a/CodeLocation.h b/CodeLocation.h
deleted file mode 100644
index c8cf5ee8..00000000
--- a/CodeLocation.h
+++ /dev/null
@@ -1,54 +0,0 @@
-/*
-	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 CodeLocation.h
- * @author Gav Wood <i@gavwood.com>
- * @date 2014
- */
-
-#pragma once
-
-#include <libethsupport/Common.h>
-#include <libethcore/Instruction.h>
-#include "Exceptions.h"
-
-namespace eth
-{
-
-class CodeFragment;
-
-class CodeLocation
-{
-	friend class CodeFragment;
-
-public:
-	CodeLocation(CodeFragment* _f);
-	CodeLocation(CodeFragment* _f, unsigned _p): m_f(_f), m_pos(_p) {}
-
-	unsigned get() const;
-	void increase(unsigned _val);
-	void set(unsigned _val);
-	void set(CodeLocation _loc) { assert(_loc.m_f == m_f); set(_loc.m_pos); }
-	void anchor();
-
-	CodeLocation operator+(unsigned _i) const { return CodeLocation(m_f, m_pos + _i); }
-
-private:
-	CodeFragment* m_f;
-	unsigned m_pos;
-};
-
-}
diff --git a/Compiler.cpp b/Compiler.cpp
index afe84eb4..777bb72d 100644
--- a/Compiler.cpp
+++ b/Compiler.cpp
@@ -27,12 +27,12 @@
 using namespace std;
 using namespace eth;
 
-bytes eth::compileLLL(string const& _s, vector<string>* _errors)
+bytes eth::compileLLL(string const& _src, vector<string>* _errors)
 {
 	try
 	{
 		CompilerState cs;
-		bytes ret = CodeFragment::compile(_s, cs).code();
+		bytes ret = CodeFragment::compile(_src, cs).code();
 		for (auto i: cs.treesToKill)
 			killBigints(i);
 		return ret;
@@ -50,6 +50,29 @@ bytes eth::compileLLL(string const& _s, vector<string>* _errors)
 	return bytes();
 }
 
+std::string eth::compileLLLToAsm(std::string const& _src, std::vector<std::string>* _errors)
+{
+	try
+	{
+		CompilerState cs;
+		string ret = CodeFragment::compile(_src, cs).assembly();
+		for (auto i: cs.treesToKill)
+			killBigints(i);
+		return ret;
+	}
+	catch (Exception const& _e)
+	{
+		if (_errors)
+			_errors->push_back(_e.description());
+	}
+	catch (std::exception)
+	{
+		if (_errors)
+			_errors->push_back("Parse error.");
+	}
+	return string();
+}
+
 string eth::parseLLL(string const& _src)
 {
 	sp::utree o;
diff --git a/Compiler.h b/Compiler.h
index e58e12ba..9dd5fc29 100644
--- a/Compiler.h
+++ b/Compiler.h
@@ -29,7 +29,8 @@ namespace eth
 {
 
 std::string parseLLL(std::string const& _src);
-bytes compileLLL(std::string const& _s, std::vector<std::string>* _errors = nullptr);
+std::string compileLLLToAsm(std::string const& _src, std::vector<std::string>* _errors = nullptr);
+bytes compileLLL(std::string const& _src, std::vector<std::string>* _errors = nullptr);
 
 }