diff options
| -rw-r--r-- | Changelog.md | 1 | ||||
| -rw-r--r-- | libevmasm/Assembly.cpp | 3 | ||||
| -rw-r--r-- | libevmasm/PeepholeOptimiser.cpp | 11 | ||||
| -rw-r--r-- | test/libevmasm/Optimiser.cpp | 14 |
4 files changed, 27 insertions, 2 deletions
diff --git a/Changelog.md b/Changelog.md index ac27ca7f..c8ea21f5 100644 --- a/Changelog.md +++ b/Changelog.md @@ -13,6 +13,7 @@ Features: * Type Checker: Require ``storage`` or ``memory`` keyword for local variables as experimental 0.5.0 feature. Bugfixes: + * Optimizer: Remove unused stack computation results. * Parser: Fix source location of VariableDeclarationStatement. * Type Checker: Properly check array length and don't rely on an assertion in code generation. * Type Checker: Properly support overwriting members inherited from ``address`` in a contract diff --git a/libevmasm/Assembly.cpp b/libevmasm/Assembly.cpp index df691e7d..5fab24e1 100644 --- a/libevmasm/Assembly.cpp +++ b/libevmasm/Assembly.cpp @@ -408,7 +408,10 @@ map<u256, u256> Assembly::optimiseInternal( { PeepholeOptimiser peepOpt(m_items); while (peepOpt.optimise()) + { count++; + assertThrow(count < 64000, OptimizerException, "Peephole optimizer seems to be stuck."); + } } // This only modifies PushTags, we have to run again to actually remove code. diff --git a/libevmasm/PeepholeOptimiser.cpp b/libevmasm/PeepholeOptimiser.cpp index 31fdd317..168d1109 100644 --- a/libevmasm/PeepholeOptimiser.cpp +++ b/libevmasm/PeepholeOptimiser.cpp @@ -249,6 +249,11 @@ void applyMethods(OptimiserState& _state, Method, OtherMethods... _other) applyMethods(_state, _other...); } +size_t numberOfPops(AssemblyItems const& _items) +{ + return std::count(_items.begin(), _items.end(), Instruction::POP); +} + } bool PeepholeOptimiser::optimise() @@ -257,8 +262,10 @@ bool PeepholeOptimiser::optimise() while (state.i < m_items.size()) applyMethods(state, PushPop(), OpPop(), DoublePush(), DoubleSwap(), JumpToNext(), UnreachableCode(), TagConjunctions(), Identity()); if (m_optimisedItems.size() < m_items.size() || ( - m_optimisedItems.size() == m_items.size() && - eth::bytesRequired(m_optimisedItems, 3) < eth::bytesRequired(m_items, 3) + m_optimisedItems.size() == m_items.size() && ( + eth::bytesRequired(m_optimisedItems, 3) < eth::bytesRequired(m_items, 3) || + numberOfPops(m_optimisedItems) > numberOfPops(m_items) + ) )) { m_items = std::move(m_optimisedItems); diff --git a/test/libevmasm/Optimiser.cpp b/test/libevmasm/Optimiser.cpp index 9dc49581..0ab95b08 100644 --- a/test/libevmasm/Optimiser.cpp +++ b/test/libevmasm/Optimiser.cpp @@ -841,6 +841,20 @@ BOOST_AUTO_TEST_CASE(peephole_double_push) ); } +BOOST_AUTO_TEST_CASE(peephole_pop_calldatasize) +{ + AssemblyItems items{ + u256(4), + Instruction::CALLDATASIZE, + Instruction::LT, + Instruction::POP + }; + PeepholeOptimiser peepOpt(items); + for (size_t i = 0; i < 3; i++) + BOOST_CHECK(peepOpt.optimise()); + BOOST_CHECK(items.empty()); +} + BOOST_AUTO_TEST_CASE(jumpdest_removal) { AssemblyItems items{ |