diff options
| -rw-r--r-- | libevmasm/PeepholeOptimiser.cpp | 110 | ||||
| -rw-r--r-- | test/libsolidity/SolidityOptimizer.cpp | 48 |
2 files changed, 116 insertions, 42 deletions
diff --git a/libevmasm/PeepholeOptimiser.cpp b/libevmasm/PeepholeOptimiser.cpp index 901e310e..16ca9535 100644 --- a/libevmasm/PeepholeOptimiser.cpp +++ b/libevmasm/PeepholeOptimiser.cpp @@ -30,36 +30,55 @@ using namespace dev; // TODO: Extend this to use the tools from ExpressionClasses.cpp -struct Identity +struct OptimiserState { - static size_t windowSize() { return 1; } - static bool apply(AssemblyItems::const_iterator _in, std::back_insert_iterator<AssemblyItems> _out) + AssemblyItems const& items; + size_t i; + std::back_insert_iterator<AssemblyItems> out; +}; + +template <class Method, size_t WindowSize> +struct SimplePeepholeOptimizerMethod +{ + static bool apply(OptimiserState& _state) + { + if ( + _state.i + WindowSize <= _state.items.size() && + Method::applySimple(_state.items.begin() + _state.i, _state.out) + ) + { + _state.i += WindowSize; + return true; + } + else + return false; + } +}; + +struct Identity: SimplePeepholeOptimizerMethod<Identity, 1> +{ + static bool applySimple(AssemblyItems::const_iterator _in, std::back_insert_iterator<AssemblyItems> _out) { *_out = *_in; return true; } }; -struct PushPop +struct PushPop: SimplePeepholeOptimizerMethod<PushPop, 2> { - static size_t windowSize() { return 2; } - static bool apply(AssemblyItems::const_iterator _in, std::back_insert_iterator<AssemblyItems>) + static size_t applySimple(AssemblyItems::const_iterator _in, std::back_insert_iterator<AssemblyItems>) { auto t = _in[0].type(); - if (_in[1] == Instruction::POP && ( + return _in[1] == Instruction::POP && ( SemanticInformation::isDupInstruction(_in[0]) || t == Push || t == PushString || t == PushTag || t == PushSub || t == PushSubSize || t == PushProgramSize || t == PushData || t == PushLibraryAddress - )) - return true; - else - return false; + ); } }; -struct AddPop +struct AddPop: SimplePeepholeOptimizerMethod<AddPop, 2> { - static size_t windowSize() { return 2; } static bool apply(AssemblyItems::const_iterator _in, std::back_insert_iterator<AssemblyItems> _out) { if (_in[1] == Instruction::POP && @@ -83,22 +102,17 @@ struct AddPop } }; -struct DoubleSwap +struct DoubleSwap: SimplePeepholeOptimizerMethod<DoubleSwap, 2> { - static size_t windowSize() { return 2; } - static bool apply(AssemblyItems::const_iterator _in, std::back_insert_iterator<AssemblyItems>) + static size_t applySimple(AssemblyItems::const_iterator _in, std::back_insert_iterator<AssemblyItems>) { - if (_in[0] == _in[1] && SemanticInformation::isSwapInstruction(_in[0])) - return true; - else - return false; + return _in[0] == _in[1] && SemanticInformation::isSwapInstruction(_in[0]); } }; -struct JumpToNext +struct JumpToNext: SimplePeepholeOptimizerMethod<JumpToNext, 3> { - static size_t windowSize() { return 3; } - static bool apply(AssemblyItems::const_iterator _in, std::back_insert_iterator<AssemblyItems> _out) + static size_t applySimple(AssemblyItems::const_iterator _in, std::back_insert_iterator<AssemblyItems> _out) { if ( _in[0].type() == PushTag && @@ -117,10 +131,41 @@ struct JumpToNext } }; -struct TagConjunctions +/// Removes everything after a JUMP (or similar) until the next JUMPDEST. +struct UnreachableCode { - static size_t windowSize() { return 3; } - static bool apply(AssemblyItems::const_iterator _in, std::back_insert_iterator<AssemblyItems> _out) + static bool apply(OptimiserState& _state) + { + auto it = _state.items.begin() + _state.i; + auto end = _state.items.end(); + if (it == end) + return false; + if ( + it[0] != Instruction::JUMP && + it[0] != Instruction::RETURN && + it[0] != Instruction::STOP && + it[0] != Instruction::SUICIDE + ) + return false; + + size_t i = 1; + while (it + i != end && it[i].type() != Tag) + i++; + if (i > 1) + { + *_state.out = it[0]; + _state.i += i; + return true; + } + else + return false; + } +}; + + +struct TagConjunctions: SimplePeepholeOptimizerMethod<TagConjunctions, 3> +{ + static bool applySimple(AssemblyItems::const_iterator _in, std::back_insert_iterator<AssemblyItems> _out) { if ( _in[0].type() == PushTag && @@ -137,13 +182,6 @@ struct TagConjunctions } }; -struct OptimiserState -{ - AssemblyItems const& items; - size_t i; - std::back_insert_iterator<AssemblyItems> out; -}; - void applyMethods(OptimiserState&) { assertThrow(false, OptimizerException, "Peephole optimizer failed to apply identity."); @@ -152,9 +190,7 @@ void applyMethods(OptimiserState&) template <typename Method, typename... OtherMethods> void applyMethods(OptimiserState& _state, Method, OtherMethods... _other) { - if (_state.i + Method::windowSize() <= _state.items.size() && Method::apply(_state.items.begin() + _state.i, _state.out)) - _state.i += Method::windowSize(); - else + if (!Method::apply(_state)) applyMethods(_state, _other...); } @@ -162,7 +198,7 @@ bool PeepholeOptimiser::optimise() { OptimiserState state {m_items, 0, std::back_inserter(m_optimisedItems)}; while (state.i < m_items.size()) - applyMethods(state, PushPop(), AddPop(), DoubleSwap(), JumpToNext(), TagConjunctions(), Identity()); + applyMethods(state, PushPop(), AddPop(), DoubleSwap(), JumpToNext(), UnreachableCode(), TagConjunctions(), Identity()); if (m_optimisedItems.size() < m_items.size()) { m_items = std::move(m_optimisedItems); diff --git a/test/libsolidity/SolidityOptimizer.cpp b/test/libsolidity/SolidityOptimizer.cpp index ecb44272..a53a2638 100644 --- a/test/libsolidity/SolidityOptimizer.cpp +++ b/test/libsolidity/SolidityOptimizer.cpp @@ -20,17 +20,21 @@ * Tests for the Solidity optimizer. */ -#include <string> -#include <tuple> -#include <memory> -#include <boost/test/unit_test.hpp> -#include <boost/lexical_cast.hpp> #include <test/libsolidity/SolidityExecutionFramework.h> + #include <libevmasm/CommonSubexpressionEliminator.h> +#include <libevmasm/PeepholeOptimiser.h> #include <libevmasm/ControlFlowGraph.h> #include <libevmasm/Assembly.h> #include <libevmasm/BlockDeduplicator.h> +#include <boost/test/unit_test.hpp> +#include <boost/lexical_cast.hpp> + +#include <string> +#include <tuple> +#include <memory> + using namespace std; using namespace dev::eth; @@ -1121,6 +1125,40 @@ BOOST_AUTO_TEST_CASE(block_deduplicator_loops) BOOST_CHECK_EQUAL(pushTags.size(), 1); } +BOOST_AUTO_TEST_CASE(clear_unreachable_code) +{ + AssemblyItems items{ + AssemblyItem(PushTag, 1), + Instruction::JUMP, + u256(0), + Instruction::SLOAD, + AssemblyItem(Tag, 2), + u256(5), + u256(6), + Instruction::SSTORE, + AssemblyItem(PushTag, 1), + Instruction::JUMP, + u256(5), + u256(6) + }; + AssemblyItems expectation{ + AssemblyItem(PushTag, 1), + Instruction::JUMP, + AssemblyItem(Tag, 2), + u256(5), + u256(6), + Instruction::SSTORE, + AssemblyItem(PushTag, 1), + Instruction::JUMP + }; + PeepholeOptimiser peepOpt(items); + BOOST_REQUIRE(peepOpt.optimise()); + BOOST_CHECK_EQUAL_COLLECTIONS( + items.begin(), items.end(), + expectation.begin(), expectation.end() + ); +} + BOOST_AUTO_TEST_CASE(computing_constants) { char const* sourceCode = R"( |