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-rw-r--r--libevmasm/ExpressionClasses.cpp343
1 files changed, 23 insertions, 320 deletions
diff --git a/libevmasm/ExpressionClasses.cpp b/libevmasm/ExpressionClasses.cpp
index d5ccd7e3..fc283b0b 100644
--- a/libevmasm/ExpressionClasses.cpp
+++ b/libevmasm/ExpressionClasses.cpp
@@ -29,6 +29,7 @@
#include <boost/noncopyable.hpp>
#include <libevmasm/Assembly.h>
#include <libevmasm/CommonSubexpressionEliminator.h>
+#include <libevmasm/SimplificationRules.h>
using namespace std;
using namespace dev;
@@ -40,8 +41,18 @@ bool ExpressionClasses::Expression::operator<(ExpressionClasses::Expression cons
assertThrow(!!item && !!_other.item, OptimizerException, "");
auto type = item->type();
auto otherType = _other.item->type();
- return std::tie(type, item->data(), arguments, sequenceNumber) <
- std::tie(otherType, _other.item->data(), _other.arguments, _other.sequenceNumber);
+ if (type != otherType)
+ return type < otherType;
+ else if (type == Operation)
+ {
+ auto instr = item->instruction();
+ auto otherInstr = _other.item->instruction();
+ return std::tie(instr, arguments, sequenceNumber) <
+ std::tie(otherInstr, _other.arguments, _other.sequenceNumber);
+ }
+ else
+ return std::tie(item->data(), arguments, sequenceNumber) <
+ std::tie(_other.item->data(), _other.arguments, _other.sequenceNumber);
}
ExpressionClasses::Id ExpressionClasses::find(
@@ -170,191 +181,6 @@ string ExpressionClasses::fullDAGToString(ExpressionClasses::Id _id) const
return str.str();
}
-class Rules: public boost::noncopyable
-{
-public:
- Rules();
- void resetMatchGroups() { m_matchGroups.clear(); }
- vector<pair<Pattern, function<Pattern()>>> rules() const { return m_rules; }
-
-private:
- using Expression = ExpressionClasses::Expression;
- map<unsigned, Expression const*> m_matchGroups;
- vector<pair<Pattern, function<Pattern()>>> m_rules;
-};
-
-template <class S> S divWorkaround(S const& _a, S const& _b)
-{
- return (S)(bigint(_a) / bigint(_b));
-}
-
-template <class S> S modWorkaround(S const& _a, S const& _b)
-{
- return (S)(bigint(_a) % bigint(_b));
-}
-
-Rules::Rules()
-{
- // Multiple occurences of one of these inside one rule must match the same equivalence class.
- // Constants.
- Pattern A(Push);
- Pattern B(Push);
- Pattern C(Push);
- // Anything.
- Pattern X;
- Pattern Y;
- Pattern Z;
- A.setMatchGroup(1, m_matchGroups);
- B.setMatchGroup(2, m_matchGroups);
- C.setMatchGroup(3, m_matchGroups);
- X.setMatchGroup(4, m_matchGroups);
- Y.setMatchGroup(5, m_matchGroups);
- Z.setMatchGroup(6, m_matchGroups);
-
- m_rules = vector<pair<Pattern, function<Pattern()>>>{
- // arithmetics on constants
- {{Instruction::ADD, {A, B}}, [=]{ return A.d() + B.d(); }},
- {{Instruction::MUL, {A, B}}, [=]{ return A.d() * B.d(); }},
- {{Instruction::SUB, {A, B}}, [=]{ return A.d() - B.d(); }},
- {{Instruction::DIV, {A, B}}, [=]{ return B.d() == 0 ? 0 : divWorkaround(A.d(), B.d()); }},
- {{Instruction::SDIV, {A, B}}, [=]{ return B.d() == 0 ? 0 : s2u(divWorkaround(u2s(A.d()), u2s(B.d()))); }},
- {{Instruction::MOD, {A, B}}, [=]{ return B.d() == 0 ? 0 : modWorkaround(A.d(), B.d()); }},
- {{Instruction::SMOD, {A, B}}, [=]{ return B.d() == 0 ? 0 : s2u(modWorkaround(u2s(A.d()), u2s(B.d()))); }},
- {{Instruction::EXP, {A, B}}, [=]{ return u256(boost::multiprecision::powm(bigint(A.d()), bigint(B.d()), bigint(1) << 256)); }},
- {{Instruction::NOT, {A}}, [=]{ return ~A.d(); }},
- {{Instruction::LT, {A, B}}, [=]() { return A.d() < B.d() ? u256(1) : 0; }},
- {{Instruction::GT, {A, B}}, [=]() -> u256 { return A.d() > B.d() ? 1 : 0; }},
- {{Instruction::SLT, {A, B}}, [=]() -> u256 { return u2s(A.d()) < u2s(B.d()) ? 1 : 0; }},
- {{Instruction::SGT, {A, B}}, [=]() -> u256 { return u2s(A.d()) > u2s(B.d()) ? 1 : 0; }},
- {{Instruction::EQ, {A, B}}, [=]() -> u256 { return A.d() == B.d() ? 1 : 0; }},
- {{Instruction::ISZERO, {A}}, [=]() -> u256 { return A.d() == 0 ? 1 : 0; }},
- {{Instruction::AND, {A, B}}, [=]{ return A.d() & B.d(); }},
- {{Instruction::OR, {A, B}}, [=]{ return A.d() | B.d(); }},
- {{Instruction::XOR, {A, B}}, [=]{ return A.d() ^ B.d(); }},
- {{Instruction::BYTE, {A, B}}, [=]{ return A.d() >= 32 ? 0 : (B.d() >> unsigned(8 * (31 - A.d()))) & 0xff; }},
- {{Instruction::ADDMOD, {A, B, C}}, [=]{ return C.d() == 0 ? 0 : u256((bigint(A.d()) + bigint(B.d())) % C.d()); }},
- {{Instruction::MULMOD, {A, B, C}}, [=]{ return C.d() == 0 ? 0 : u256((bigint(A.d()) * bigint(B.d())) % C.d()); }},
- {{Instruction::MULMOD, {A, B, C}}, [=]{ return A.d() * B.d(); }},
- {{Instruction::SIGNEXTEND, {A, B}}, [=]() -> u256 {
- if (A.d() >= 31)
- return B.d();
- unsigned testBit = unsigned(A.d()) * 8 + 7;
- u256 mask = (u256(1) << testBit) - 1;
- return u256(boost::multiprecision::bit_test(B.d(), testBit) ? B.d() | ~mask : B.d() & mask);
- }},
-
- // invariants involving known constants
- {{Instruction::ADD, {X, 0}}, [=]{ return X; }},
- {{Instruction::SUB, {X, 0}}, [=]{ return X; }},
- {{Instruction::MUL, {X, 1}}, [=]{ return X; }},
- {{Instruction::DIV, {X, 1}}, [=]{ return X; }},
- {{Instruction::SDIV, {X, 1}}, [=]{ return X; }},
- {{Instruction::OR, {X, 0}}, [=]{ return X; }},
- {{Instruction::XOR, {X, 0}}, [=]{ return X; }},
- {{Instruction::AND, {X, ~u256(0)}}, [=]{ return X; }},
- {{Instruction::AND, {X, 0}}, [=]{ return u256(0); }},
- {{Instruction::MUL, {X, 0}}, [=]{ return u256(0); }},
- {{Instruction::DIV, {X, 0}}, [=]{ return u256(0); }},
- {{Instruction::DIV, {0, X}}, [=]{ return u256(0); }},
- {{Instruction::MOD, {X, 0}}, [=]{ return u256(0); }},
- {{Instruction::MOD, {0, X}}, [=]{ return u256(0); }},
- {{Instruction::OR, {X, ~u256(0)}}, [=]{ return ~u256(0); }},
- {{Instruction::EQ, {X, 0}}, [=]() -> Pattern { return {Instruction::ISZERO, {X}}; } },
- // operations involving an expression and itself
- {{Instruction::AND, {X, X}}, [=]{ return X; }},
- {{Instruction::OR, {X, X}}, [=]{ return X; }},
- {{Instruction::XOR, {X, X}}, [=]{ return u256(0); }},
- {{Instruction::SUB, {X, X}}, [=]{ return u256(0); }},
- {{Instruction::EQ, {X, X}}, [=]{ return u256(1); }},
- {{Instruction::LT, {X, X}}, [=]{ return u256(0); }},
- {{Instruction::SLT, {X, X}}, [=]{ return u256(0); }},
- {{Instruction::GT, {X, X}}, [=]{ return u256(0); }},
- {{Instruction::SGT, {X, X}}, [=]{ return u256(0); }},
- {{Instruction::MOD, {X, X}}, [=]{ return u256(0); }},
-
- {{Instruction::NOT, {{Instruction::NOT, {X}}}}, [=]{ return X; }},
- {{Instruction::XOR, {{{X}, {Instruction::XOR, {X, Y}}}}}, [=]{ return Y; }},
- {{Instruction::OR, {{{X}, {Instruction::AND, {X, Y}}}}}, [=]{ return X; }},
- {{Instruction::AND, {{{X}, {Instruction::OR, {X, Y}}}}}, [=]{ return X; }},
- {{Instruction::AND, {{{X}, {Instruction::NOT, {X}}}}}, [=]{ return u256(0); }},
- {{Instruction::OR, {{{X}, {Instruction::NOT, {X}}}}}, [=]{ return ~u256(0); }},
- };
- // Double negation of opcodes with binary result
- for (auto const& op: vector<Instruction>{
- Instruction::EQ,
- Instruction::LT,
- Instruction::SLT,
- Instruction::GT,
- Instruction::SGT
- })
- m_rules.push_back({
- {Instruction::ISZERO, {{Instruction::ISZERO, {{op, {X, Y}}}}}},
- [=]() -> Pattern { return {op, {X, Y}}; }
- });
- m_rules.push_back({
- {Instruction::ISZERO, {{Instruction::ISZERO, {{Instruction::ISZERO, {X}}}}}},
- [=]() -> Pattern { return {Instruction::ISZERO, {X}}; }
- });
- m_rules.push_back({
- {Instruction::ISZERO, {{Instruction::XOR, {X, Y}}}},
- [=]() -> Pattern { return { Instruction::EQ, {X, Y} }; }
- });
- // Associative operations
- for (auto const& opFun: vector<pair<Instruction,function<u256(u256 const&,u256 const&)>>>{
- {Instruction::ADD, plus<u256>()},
- {Instruction::MUL, multiplies<u256>()},
- {Instruction::AND, bit_and<u256>()},
- {Instruction::OR, bit_or<u256>()},
- {Instruction::XOR, bit_xor<u256>()}
- })
- {
- auto op = opFun.first;
- auto fun = opFun.second;
- // Moving constants to the outside, order matters here!
- // we need actions that return expressions (or patterns?) here, and we need also reversed rules
- // (X+A)+B -> X+(A+B)
- m_rules += vector<pair<Pattern, function<Pattern()>>>{{
- {op, {{op, {X, A}}, B}},
- [=]() -> Pattern { return {op, {X, fun(A.d(), B.d())}}; }
- }, {
- // X+(Y+A) -> (X+Y)+A
- {op, {{op, {X, A}}, Y}},
- [=]() -> Pattern { return {op, {{op, {X, Y}}, A}}; }
- }, {
- // For now, we still need explicit commutativity for the inner pattern
- {op, {{op, {A, X}}, B}},
- [=]() -> Pattern { return {op, {X, fun(A.d(), B.d())}}; }
- }, {
- {op, {{op, {A, X}}, Y}},
- [=]() -> Pattern { return {op, {{op, {X, Y}}, A}}; }
- }};
- }
- // move constants across subtractions
- m_rules += vector<pair<Pattern, function<Pattern()>>>{
- {
- // X - A -> X + (-A)
- {Instruction::SUB, {X, A}},
- [=]() -> Pattern { return {Instruction::ADD, {X, 0 - A.d()}}; }
- }, {
- // (X + A) - Y -> (X - Y) + A
- {Instruction::SUB, {{Instruction::ADD, {X, A}}, Y}},
- [=]() -> Pattern { return {Instruction::ADD, {{Instruction::SUB, {X, Y}}, A}}; }
- }, {
- // (A + X) - Y -> (X - Y) + A
- {Instruction::SUB, {{Instruction::ADD, {A, X}}, Y}},
- [=]() -> Pattern { return {Instruction::ADD, {{Instruction::SUB, {X, Y}}, A}}; }
- }, {
- // X - (Y + A) -> (X - Y) + (-A)
- {Instruction::SUB, {X, {Instruction::ADD, {Y, A}}}},
- [=]() -> Pattern { return {Instruction::ADD, {{Instruction::SUB, {X, Y}}, 0 - A.d()}}; }
- }, {
- // X - (A + Y) -> (X - Y) + (-A)
- {Instruction::SUB, {X, {Instruction::ADD, {A, Y}}}},
- [=]() -> Pattern { return {Instruction::ADD, {{Instruction::SUB, {X, Y}}, 0 - A.d()}}; }
- }
- };
-}
-
ExpressionClasses::Id ExpressionClasses::tryToSimplify(Expression const& _expr, bool _secondRun)
{
static Rules rules;
@@ -366,21 +192,17 @@ ExpressionClasses::Id ExpressionClasses::tryToSimplify(Expression const& _expr,
)
return -1;
- for (auto const& rule: rules.rules())
+ if (auto match = rules.findFirstMatch(_expr, *this))
{
- rules.resetMatchGroups();
- if (rule.first.matches(_expr, *this))
- {
- // Debug info
- //cout << "Simplifying " << *_expr.item << "(";
- //for (Id arg: _expr.arguments)
- // cout << fullDAGToString(arg) << ", ";
- //cout << ")" << endl;
- //cout << "with rule " << rule.first.toString() << endl;
- //ExpressionTemplate t(rule.second());
- //cout << "to " << rule.second().toString() << endl;
- return rebuildExpression(ExpressionTemplate(rule.second(), _expr.item->location()));
- }
+ // Debug info
+ //cout << "Simplifying " << *_expr.item << "(";
+ //for (Id arg: _expr.arguments)
+ // cout << fullDAGToString(arg) << ", ";
+ //cout << ")" << endl;
+ //cout << "with rule " << match->first.toString() << endl;
+ //ExpressionTemplate t(match->second());
+ //cout << "to " << match->second().toString() << endl;
+ return rebuildExpression(ExpressionTemplate(match->second(), _expr.item->location()));
}
if (!_secondRun && _expr.arguments.size() == 2 && SemanticInformation::isCommutativeOperation(*_expr.item))
@@ -403,122 +225,3 @@ ExpressionClasses::Id ExpressionClasses::rebuildExpression(ExpressionTemplate co
arguments.push_back(rebuildExpression(t));
return find(_template.item, arguments);
}
-
-
-Pattern::Pattern(Instruction _instruction, std::vector<Pattern> const& _arguments):
- m_type(Operation),
- m_requireDataMatch(true),
- m_data(_instruction),
- m_arguments(_arguments)
-{
-}
-
-void Pattern::setMatchGroup(unsigned _group, map<unsigned, Expression const*>& _matchGroups)
-{
- m_matchGroup = _group;
- m_matchGroups = &_matchGroups;
-}
-
-bool Pattern::matches(Expression const& _expr, ExpressionClasses const& _classes) const
-{
- if (!matchesBaseItem(_expr.item))
- return false;
- if (m_matchGroup)
- {
- if (!m_matchGroups->count(m_matchGroup))
- (*m_matchGroups)[m_matchGroup] = &_expr;
- else if ((*m_matchGroups)[m_matchGroup]->id != _expr.id)
- return false;
- }
- assertThrow(m_arguments.size() == 0 || _expr.arguments.size() == m_arguments.size(), OptimizerException, "");
- for (size_t i = 0; i < m_arguments.size(); ++i)
- if (!m_arguments[i].matches(_classes.representative(_expr.arguments[i]), _classes))
- return false;
- return true;
-}
-
-AssemblyItem Pattern::toAssemblyItem(SourceLocation const& _location) const
-{
- return AssemblyItem(m_type, m_data, _location);
-}
-
-string Pattern::toString() const
-{
- stringstream s;
- switch (m_type)
- {
- case Operation:
- s << instructionInfo(Instruction(unsigned(m_data))).name;
- break;
- case Push:
- s << "PUSH " << hex << m_data;
- break;
- case UndefinedItem:
- s << "ANY";
- break;
- default:
- s << "t=" << dec << m_type << " d=" << hex << m_data;
- break;
- }
- if (!m_requireDataMatch)
- s << " ~";
- if (m_matchGroup)
- s << "[" << dec << m_matchGroup << "]";
- s << "(";
- for (Pattern const& p: m_arguments)
- s << p.toString() << ", ";
- s << ")";
- return s.str();
-}
-
-bool Pattern::matchesBaseItem(AssemblyItem const* _item) const
-{
- if (m_type == UndefinedItem)
- return true;
- if (!_item)
- return false;
- if (m_type != _item->type())
- return false;
- if (m_requireDataMatch && m_data != _item->data())
- return false;
- return true;
-}
-
-Pattern::Expression const& Pattern::matchGroupValue() const
-{
- assertThrow(m_matchGroup > 0, OptimizerException, "");
- assertThrow(!!m_matchGroups, OptimizerException, "");
- assertThrow((*m_matchGroups)[m_matchGroup], OptimizerException, "");
- return *(*m_matchGroups)[m_matchGroup];
-}
-
-
-ExpressionTemplate::ExpressionTemplate(Pattern const& _pattern, SourceLocation const& _location)
-{
- if (_pattern.matchGroup())
- {
- hasId = true;
- id = _pattern.id();
- }
- else
- {
- hasId = false;
- item = _pattern.toAssemblyItem(_location);
- }
- for (auto const& arg: _pattern.arguments())
- arguments.push_back(ExpressionTemplate(arg, _location));
-}
-
-string ExpressionTemplate::toString() const
-{
- stringstream s;
- if (hasId)
- s << id;
- else
- s << item;
- s << "(";
- for (auto const& arg: arguments)
- s << arg.toString();
- s << ")";
- return s.str();
-}
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