mirror of
https://github.com/ethereum/solidity
synced 2023-10-03 13:03:40 +00:00
some more work
This commit is contained in:
chriseth
parent
bd7676873e
commit
ddbcea047b
@ -47,6 +47,9 @@ void UnusedAssignEliminator::run(OptimiserStepContext& _context, Block& _ast)
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set<Statement const*> toRemove;
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for (Statement const* unusedStore: rae.m_allStores - rae.m_usedStores)
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// TODO this should also use user function side effects.
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// Then we have to modify the multi-assign test (or verify that it is fine after all
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// by adding a test where one var is used but not the other)
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if (SideEffectsCollector{_context.dialect, *std::get<Assignment>(*unusedStore).value}.movable())
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toRemove.insert(unusedStore);
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else
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@ -111,8 +114,6 @@ void UnusedAssignEliminator::visit(Statement const& _statement)
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if (auto const* assignment = get_if<Assignment>(&_statement))
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{
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// TODO is it OK to do this for multi-assignments? I guess so because it is enough if
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// one of them is used.
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m_allStores.insert(&_statement);
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for (auto const& var: assignment->variableNames)
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m_activeStores[var.name] = {&_statement};
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@ -52,123 +52,125 @@ static string const thirtyTwo{"@ 32"};
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void UnusedStoreEliminator::run(OptimiserStepContext& /*_context*/, Block& /*_ast*/)
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{
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// map<YulString, SideEffects> functionSideEffects = SideEffectsPropagator::sideEffects(
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// _context.dialect,
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// CallGraphGenerator::callGraph(_ast)
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// );
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map<YulString, SideEffects> functionSideEffects = SideEffectsPropagator::sideEffects(
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_context.dialect,
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CallGraphGenerator::callGraph(_ast)
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);
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// SSAValueTracker ssaValues;
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// ssaValues(_ast);
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// map<YulString, AssignedValue> values;
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// for (auto const& [name, expression]: ssaValues.values())
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// values[name] = AssignedValue{expression, {}};
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// Expression const zeroLiteral{Literal{{}, LiteralKind::Number, YulString{"0"}, {}}};
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// Expression const oneLiteral{Literal{{}, LiteralKind::Number, YulString{"1"}, {}}};
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// Expression const thirtyTwoLiteral{Literal{{}, LiteralKind::Number, YulString{"32"}, {}}};
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// values[YulString{zero}] = AssignedValue{&zeroLiteral, {}};
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// values[YulString{one}] = AssignedValue{&oneLiteral, {}};
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// values[YulString{thirtyTwo}] = AssignedValue{&thirtyTwoLiteral, {}};
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SSAValueTracker ssaValues;
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ssaValues(_ast);
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map<YulString, AssignedValue> values;
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for (auto const& [name, expression]: ssaValues.values())
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values[name] = AssignedValue{expression, {}};
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Expression const zeroLiteral{Literal{{}, LiteralKind::Number, YulString{"0"}, {}}};
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Expression const oneLiteral{Literal{{}, LiteralKind::Number, YulString{"1"}, {}}};
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Expression const thirtyTwoLiteral{Literal{{}, LiteralKind::Number, YulString{"32"}, {}}};
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values[YulString{zero}] = AssignedValue{&zeroLiteral, {}};
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values[YulString{one}] = AssignedValue{&oneLiteral, {}};
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values[YulString{thirtyTwo}] = AssignedValue{&thirtyTwoLiteral, {}};
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// bool const ignoreMemory = MSizeFinder::containsMSize(_context.dialect, _ast);
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// UnusedStoreEliminator rse{
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// _context.dialect,
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// functionSideEffects,
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// ControlFlowSideEffectsCollector{_context.dialect, _ast}.functionSideEffectsNamed(),
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// values,
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// ignoreMemory
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// };
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// rse(_ast);
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// if (
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// auto evmDialect = dynamic_cast<EVMDialect const*>(&_context.dialect);
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// evmDialect && evmDialect->providesObjectAccess()
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// )
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// rse.changeUndecidedTo(State::Unused, Location::Memory);
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// else
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// rse.changeUndecidedTo(State::Used, Location::Memory);
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// rse.changeUndecidedTo(State::Used, Location::Storage);
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// rse.scheduleUnusedForDeletion();
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bool const ignoreMemory = MSizeFinder::containsMSize(_context.dialect, _ast);
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UnusedStoreEliminator rse{
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_context.dialect,
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functionSideEffects,
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ControlFlowSideEffectsCollector{_context.dialect, _ast}.functionSideEffectsNamed(),
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values,
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ignoreMemory
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};
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rse(_ast);
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if (
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auto evmDialect = dynamic_cast<EVMDialect const*>(&_context.dialect);
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evmDialect && evmDialect->providesObjectAccess()
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)
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{
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}
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else
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rse.markActiveAsUsed(Location::Memory);
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rse.markActiveAsUsed(Location::Storage);
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rse.scheduleUnusedForDeletion();
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// StatementRemover remover(rse.m_pendingRemovals);
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// remover(_ast);
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StatementRemover remover(rse.m_pendingRemovals);
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remover(_ast);
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}
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//void UnusedStoreEliminator::operator()(FunctionCall const& _functionCall)
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//{
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// UnusedStoreBase::operator()(_functionCall);
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void UnusedStoreEliminator::operator()(FunctionCall const& _functionCall)
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{
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UnusedStoreBase::operator()(_functionCall);
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// for (Operation const& op: operationsFromFunctionCall(_functionCall))
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// applyOperation(op);
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for (Operation const& op: operationsFromFunctionCall(_functionCall))
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applyOperation(op);
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// ControlFlowSideEffects sideEffects;
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// if (auto builtin = m_dialect.builtin(_functionCall.functionName.name))
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// sideEffects = builtin->controlFlowSideEffects;
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// else
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// sideEffects = m_controlFlowSideEffects.at(_functionCall.functionName.name);
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ControlFlowSideEffects sideEffects;
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if (auto builtin = m_dialect.builtin(_functionCall.functionName.name))
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sideEffects = builtin->controlFlowSideEffects;
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else
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sideEffects = m_controlFlowSideEffects.at(_functionCall.functionName.name);
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// if (sideEffects.canTerminate)
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// changeUndecidedTo(State::Used, Location::Storage);
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// if (!sideEffects.canContinue)
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// {
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// changeUndecidedTo(State::Unused, Location::Memory);
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// if (!sideEffects.canTerminate)
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// changeUndecidedTo(State::Unused, Location::Storage);
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// }
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//}
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if (sideEffects.canTerminate)
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markActiveAsUsed(Location::Storage);
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if (!sideEffects.canContinue)
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{
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clearActive(Location::Memory);
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if (!sideEffects.canTerminate)
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clearActive(Location::Storage);
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}
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}
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//void UnusedStoreEliminator::operator()(FunctionDefinition const& _functionDefinition)
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//{
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// ScopedSaveAndRestore storeOperations(m_storeOperations, {});
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// UnusedStoreBase::operator()(_functionDefinition);
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//}
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void UnusedStoreEliminator::operator()(FunctionDefinition const& _functionDefinition)
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{
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ScopedSaveAndRestore storeOperations(m_storeOperations, {});
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UnusedStoreBase::operator()(_functionDefinition);
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}
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//void UnusedStoreEliminator::operator()(Leave const&)
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//{
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// changeUndecidedTo(State::Used);
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//}
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void UnusedStoreEliminator::operator()(Leave const&)
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{
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markActiveAsUsed();
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}
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//void UnusedStoreEliminator::visit(Statement const& _statement)
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//{
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// using evmasm::Instruction;
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void UnusedStoreEliminator::visit(Statement const& _statement)
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{
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using evmasm::Instruction;
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// UnusedStoreBase::visit(_statement);
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UnusedStoreBase::visit(_statement);
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// auto const* exprStatement = get_if<ExpressionStatement>(&_statement);
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// if (!exprStatement)
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// return;
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auto const* exprStatement = get_if<ExpressionStatement>(&_statement);
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if (!exprStatement)
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return;
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// FunctionCall const* funCall = get_if<FunctionCall>(&exprStatement->expression);
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// yulAssert(funCall);
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// optional<Instruction> instruction = toEVMInstruction(m_dialect, funCall->functionName.name);
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// if (!instruction)
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// return;
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FunctionCall const* funCall = get_if<FunctionCall>(&exprStatement->expression);
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yulAssert(funCall);
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optional<Instruction> instruction = toEVMInstruction(m_dialect, funCall->functionName.name);
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if (!instruction)
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return;
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// if (!ranges::all_of(funCall->arguments, [](Expression const& _expr) -> bool {
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// return get_if<Identifier>(&_expr) || get_if<Literal>(&_expr);
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// }))
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// return;
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if (!ranges::all_of(funCall->arguments, [](Expression const& _expr) -> bool {
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return get_if<Identifier>(&_expr) || get_if<Literal>(&_expr);
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}))
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return;
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// // We determine if this is a store instruction without additional side-effects
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// // both by querying a combination of semantic information and by listing the instructions.
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// // This way the assert below should be triggered on any change.
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// using evmasm::SemanticInformation;
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// bool isStorageWrite = (*instruction == Instruction::SSTORE);
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// bool isMemoryWrite =
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// *instruction == Instruction::EXTCODECOPY ||
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// *instruction == Instruction::CODECOPY ||
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// *instruction == Instruction::CALLDATACOPY ||
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// *instruction == Instruction::RETURNDATACOPY ||
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// *instruction == Instruction::MSTORE ||
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// *instruction == Instruction::MSTORE8;
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// bool isCandidateForRemoval =
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// SemanticInformation::otherState(*instruction) != SemanticInformation::Write && (
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// SemanticInformation::storage(*instruction) == SemanticInformation::Write ||
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// (!m_ignoreMemory && SemanticInformation::memory(*instruction) == SemanticInformation::Write)
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// );
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// yulAssert(isCandidateForRemoval == (isStorageWrite || (!m_ignoreMemory && isMemoryWrite)));
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// if (isCandidateForRemoval)
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// {
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// State initialState = State::Undecided;
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// We determine if this is a store instruction without additional side-effects
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// both by querying a combination of semantic information and by listing the instructions.
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// This way the assert below should be triggered on any change.
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using evmasm::SemanticInformation;
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bool isStorageWrite = (*instruction == Instruction::SSTORE);
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bool isMemoryWrite =
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*instruction == Instruction::EXTCODECOPY ||
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*instruction == Instruction::CODECOPY ||
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*instruction == Instruction::CALLDATACOPY ||
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*instruction == Instruction::RETURNDATACOPY ||
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*instruction == Instruction::MSTORE ||
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*instruction == Instruction::MSTORE8;
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bool isCandidateForRemoval =
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SemanticInformation::otherState(*instruction) != SemanticInformation::Write && (
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SemanticInformation::storage(*instruction) == SemanticInformation::Write ||
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(!m_ignoreMemory && SemanticInformation::memory(*instruction) == SemanticInformation::Write)
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);
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yulAssert(isCandidateForRemoval == (isStorageWrite || (!m_ignoreMemory && isMemoryWrite)));
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if (isCandidateForRemoval)
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{
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// TODO what is this special case?
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//State initialState = State::Undecided;
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// if (*instruction == Instruction::RETURNDATACOPY)
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// {
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// initialState = State::Used;
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@ -186,223 +188,254 @@ void UnusedStoreEliminator::run(OptimiserStepContext& /*_context*/, Block& /*_as
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// initialState = State::Undecided;
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// }
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// }
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// m_activeStores[YulString{}].insert({&_statement, initialState});
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// vector<Operation> operations = operationsFromFunctionCall(*funCall);
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// yulAssert(operations.size() == 1, "");
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// m_storeOperations[&_statement] = std::move(operations.front());
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// }
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//}
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m_allStores.insert(&_statement);
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vector<Operation> operations = operationsFromFunctionCall(*funCall);
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yulAssert(operations.size() == 1, "");
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if (operations.front().location == Location::Storage)
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m_activeStores["s"_yulstring].insert(&_statement);
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else
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m_activeStores["m"_yulstring].insert(&_statement);
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m_storeOperations[&_statement] = std::move(operations.front());
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}
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}
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//void UnusedStoreEliminator::finalizeFunctionDefinition(FunctionDefinition const&)
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//{
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// changeUndecidedTo(State::Used);
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// scheduleUnusedForDeletion();
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//}
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void UnusedStoreEliminator::finalizeFunctionDefinition(FunctionDefinition const&)
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{
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markActiveAsUsed();
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scheduleUnusedForDeletion();
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}
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//vector<UnusedStoreEliminator::Operation> UnusedStoreEliminator::operationsFromFunctionCall(
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// FunctionCall const& _functionCall
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//) const
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//{
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// using evmasm::Instruction;
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vector<UnusedStoreEliminator::Operation> UnusedStoreEliminator::operationsFromFunctionCall(
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FunctionCall const& _functionCall
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) const
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{
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using evmasm::Instruction;
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// YulString functionName = _functionCall.functionName.name;
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// SideEffects sideEffects;
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// if (BuiltinFunction const* f = m_dialect.builtin(functionName))
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// sideEffects = f->sideEffects;
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// else
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// sideEffects = m_functionSideEffects.at(functionName);
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YulString functionName = _functionCall.functionName.name;
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SideEffects sideEffects;
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if (BuiltinFunction const* f = m_dialect.builtin(functionName))
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sideEffects = f->sideEffects;
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else
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sideEffects = m_functionSideEffects.at(functionName);
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// optional<Instruction> instruction = toEVMInstruction(m_dialect, functionName);
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// if (!instruction)
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// {
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// vector<Operation> result;
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// // Unknown read is worse than unknown write.
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// if (sideEffects.memory != SideEffects::Effect::None)
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// result.emplace_back(Operation{Location::Memory, Effect::Read, {}, {}});
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// if (sideEffects.storage != SideEffects::Effect::None)
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// result.emplace_back(Operation{Location::Storage, Effect::Read, {}, {}});
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// return result;
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// }
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optional<Instruction> instruction = toEVMInstruction(m_dialect, functionName);
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if (!instruction)
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{
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vector<Operation> result;
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// Unknown read is worse than unknown write.
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if (sideEffects.memory != SideEffects::Effect::None)
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result.emplace_back(Operation{Location::Memory, Effect::Read, {}, {}});
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if (sideEffects.storage != SideEffects::Effect::None)
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result.emplace_back(Operation{Location::Storage, Effect::Read, {}, {}});
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return result;
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}
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// using evmasm::SemanticInformation;
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using evmasm::SemanticInformation;
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// return util::applyMap(
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// SemanticInformation::readWriteOperations(*instruction),
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// [&](SemanticInformation::Operation const& _op) -> Operation
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// {
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// yulAssert(!(_op.lengthParameter && _op.lengthConstant));
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// yulAssert(_op.effect != Effect::None);
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// Operation ourOp{_op.location, _op.effect, {}, {}};
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// if (_op.startParameter)
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// ourOp.start = identifierNameIfSSA(_functionCall.arguments.at(*_op.startParameter));
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// if (_op.lengthParameter)
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// ourOp.length = identifierNameIfSSA(_functionCall.arguments.at(*_op.lengthParameter));
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// if (_op.lengthConstant)
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// switch (*_op.lengthConstant)
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// {
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// case 1: ourOp.length = YulString(one); break;
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// case 32: ourOp.length = YulString(thirtyTwo); break;
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// default: yulAssert(false);
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// }
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// return ourOp;
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// }
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// );
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//}
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return util::applyMap(
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SemanticInformation::readWriteOperations(*instruction),
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[&](SemanticInformation::Operation const& _op) -> Operation
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{
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yulAssert(!(_op.lengthParameter && _op.lengthConstant));
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yulAssert(_op.effect != Effect::None);
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Operation ourOp{_op.location, _op.effect, {}, {}};
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if (_op.startParameter)
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ourOp.start = identifierNameIfSSA(_functionCall.arguments.at(*_op.startParameter));
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if (_op.lengthParameter)
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ourOp.length = identifierNameIfSSA(_functionCall.arguments.at(*_op.lengthParameter));
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if (_op.lengthConstant)
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switch (*_op.lengthConstant)
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{
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case 1: ourOp.length = YulString(one); break;
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case 32: ourOp.length = YulString(thirtyTwo); break;
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default: yulAssert(false);
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}
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return ourOp;
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}
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);
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}
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//void UnusedStoreEliminator::applyOperation(UnusedStoreEliminator::Operation const& _operation)
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//{
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// for (auto& [statement, state]: m_activeStores[YulString{}])
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// if (state == State::Undecided)
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// {
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// Operation const& storeOperation = m_storeOperations.at(statement);
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// if (_operation.effect == Effect::Read && !knownUnrelated(storeOperation, _operation))
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// state = State::Used;
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// else if (_operation.effect == Effect::Write && knownCovered(storeOperation, _operation))
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void UnusedStoreEliminator::applyOperation(UnusedStoreEliminator::Operation const& _operation)
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{
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// TODO only one will be relevant, depending on _operation.location
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for (Statement const* statement: m_activeStores["s"_yulstring])
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{
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Operation const& storeOperation = m_storeOperations.at(statement);
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if (_operation.effect == Effect::Read && !knownUnrelated(storeOperation, _operation))
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// TODO remove from active!
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m_usedStores.insert(statement);
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else if (_operation.effect == Effect::Write && knownCovered(storeOperation, _operation))
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{
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// TODO remove from active
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// state = State::Unused;
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// }
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//}
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}
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}
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for (Statement const* statement: m_activeStores["m"_yulstring])
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{
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Operation const& storeOperation = m_storeOperations.at(statement);
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if (_operation.effect == Effect::Read && !knownUnrelated(storeOperation, _operation))
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// TODO remove from active!
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m_usedStores.insert(statement);
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else if (_operation.effect == Effect::Write && knownCovered(storeOperation, _operation))
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{
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// TODO remove from active
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// state = State::Unused;
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}
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}
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}
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//bool UnusedStoreEliminator::knownUnrelated(
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// UnusedStoreEliminator::Operation const& _op1,
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// UnusedStoreEliminator::Operation const& _op2
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//) const
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//{
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// KnowledgeBase knowledge(m_dialect, [this](YulString _var) { return util::valueOrNullptr(m_ssaValues, _var); });
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bool UnusedStoreEliminator::knownUnrelated(
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UnusedStoreEliminator::Operation const& _op1,
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UnusedStoreEliminator::Operation const& _op2
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) const
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{
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KnowledgeBase knowledge(m_dialect, [this](YulString _var) { return util::valueOrNullptr(m_ssaValues, _var); });
|
||||
|
||||
// if (_op1.location != _op2.location)
|
||||
// return true;
|
||||
// if (_op1.location == Location::Storage)
|
||||
// {
|
||||
// if (_op1.start && _op2.start)
|
||||
// {
|
||||
// yulAssert(
|
||||
// _op1.length &&
|
||||
// _op2.length &&
|
||||
// knowledge.valueIfKnownConstant(*_op1.length) == 1 &&
|
||||
// knowledge.valueIfKnownConstant(*_op2.length) == 1
|
||||
// );
|
||||
// return knowledge.knownToBeDifferent(*_op1.start, *_op2.start);
|
||||
// }
|
||||
// }
|
||||
// else
|
||||
// {
|
||||
// yulAssert(_op1.location == Location::Memory, "");
|
||||
// if (
|
||||
// (_op1.length && knowledge.knownToBeZero(*_op1.length)) ||
|
||||
// (_op2.length && knowledge.knownToBeZero(*_op2.length))
|
||||
// )
|
||||
// return true;
|
||||
if (_op1.location != _op2.location)
|
||||
return true;
|
||||
if (_op1.location == Location::Storage)
|
||||
{
|
||||
if (_op1.start && _op2.start)
|
||||
{
|
||||
yulAssert(
|
||||
_op1.length &&
|
||||
_op2.length &&
|
||||
knowledge.valueIfKnownConstant(*_op1.length) == 1 &&
|
||||
knowledge.valueIfKnownConstant(*_op2.length) == 1
|
||||
);
|
||||
return knowledge.knownToBeDifferent(*_op1.start, *_op2.start);
|
||||
}
|
||||
}
|
||||
else
|
||||
{
|
||||
yulAssert(_op1.location == Location::Memory, "");
|
||||
if (
|
||||
(_op1.length && knowledge.knownToBeZero(*_op1.length)) ||
|
||||
(_op2.length && knowledge.knownToBeZero(*_op2.length))
|
||||
)
|
||||
return true;
|
||||
|
||||
// if (_op1.start && _op1.length && _op2.start)
|
||||
// {
|
||||
// optional<u256> length1 = knowledge.valueIfKnownConstant(*_op1.length);
|
||||
// optional<u256> start1 = knowledge.valueIfKnownConstant(*_op1.start);
|
||||
// optional<u256> start2 = knowledge.valueIfKnownConstant(*_op2.start);
|
||||
// if (
|
||||
// (length1 && start1 && start2) &&
|
||||
// *start1 + *length1 >= *start1 && // no overflow
|
||||
// *start1 + *length1 <= *start2
|
||||
// )
|
||||
// return true;
|
||||
// }
|
||||
// if (_op2.start && _op2.length && _op1.start)
|
||||
// {
|
||||
// optional<u256> length2 = knowledge.valueIfKnownConstant(*_op2.length);
|
||||
// optional<u256> start2 = knowledge.valueIfKnownConstant(*_op2.start);
|
||||
// optional<u256> start1 = knowledge.valueIfKnownConstant(*_op1.start);
|
||||
// if (
|
||||
// (length2 && start2 && start1) &&
|
||||
// *start2 + *length2 >= *start2 && // no overflow
|
||||
// *start2 + *length2 <= *start1
|
||||
// )
|
||||
// return true;
|
||||
// }
|
||||
if (_op1.start && _op1.length && _op2.start)
|
||||
{
|
||||
optional<u256> length1 = knowledge.valueIfKnownConstant(*_op1.length);
|
||||
optional<u256> start1 = knowledge.valueIfKnownConstant(*_op1.start);
|
||||
optional<u256> start2 = knowledge.valueIfKnownConstant(*_op2.start);
|
||||
if (
|
||||
(length1 && start1 && start2) &&
|
||||
*start1 + *length1 >= *start1 && // no overflow
|
||||
*start1 + *length1 <= *start2
|
||||
)
|
||||
return true;
|
||||
}
|
||||
if (_op2.start && _op2.length && _op1.start)
|
||||
{
|
||||
optional<u256> length2 = knowledge.valueIfKnownConstant(*_op2.length);
|
||||
optional<u256> start2 = knowledge.valueIfKnownConstant(*_op2.start);
|
||||
optional<u256> start1 = knowledge.valueIfKnownConstant(*_op1.start);
|
||||
if (
|
||||
(length2 && start2 && start1) &&
|
||||
*start2 + *length2 >= *start2 && // no overflow
|
||||
*start2 + *length2 <= *start1
|
||||
)
|
||||
return true;
|
||||
}
|
||||
|
||||
// if (_op1.start && _op1.length && _op2.start && _op2.length)
|
||||
// {
|
||||
// optional<u256> length1 = knowledge.valueIfKnownConstant(*_op1.length);
|
||||
// optional<u256> length2 = knowledge.valueIfKnownConstant(*_op2.length);
|
||||
// if (
|
||||
// (length1 && *length1 <= 32) &&
|
||||
// (length2 && *length2 <= 32) &&
|
||||
// knowledge.knownToBeDifferentByAtLeast32(*_op1.start, *_op2.start)
|
||||
// )
|
||||
// return true;
|
||||
// }
|
||||
// }
|
||||
if (_op1.start && _op1.length && _op2.start && _op2.length)
|
||||
{
|
||||
optional<u256> length1 = knowledge.valueIfKnownConstant(*_op1.length);
|
||||
optional<u256> length2 = knowledge.valueIfKnownConstant(*_op2.length);
|
||||
if (
|
||||
(length1 && *length1 <= 32) &&
|
||||
(length2 && *length2 <= 32) &&
|
||||
knowledge.knownToBeDifferentByAtLeast32(*_op1.start, *_op2.start)
|
||||
)
|
||||
return true;
|
||||
}
|
||||
}
|
||||
|
||||
// return false;
|
||||
//}
|
||||
return false;
|
||||
}
|
||||
|
||||
//bool UnusedStoreEliminator::knownCovered(
|
||||
// UnusedStoreEliminator::Operation const& _covered,
|
||||
// UnusedStoreEliminator::Operation const& _covering
|
||||
//) const
|
||||
//{
|
||||
// if (_covered.location != _covering.location)
|
||||
// return false;
|
||||
// if (
|
||||
// (_covered.start && _covered.start == _covering.start) &&
|
||||
// (_covered.length && _covered.length == _covering.length)
|
||||
// )
|
||||
// return true;
|
||||
// if (_covered.location == Location::Memory)
|
||||
// {
|
||||
// KnowledgeBase knowledge(m_dialect, [this](YulString _var) { return util::valueOrNullptr(m_ssaValues, _var); });
|
||||
bool UnusedStoreEliminator::knownCovered(
|
||||
UnusedStoreEliminator::Operation const& _covered,
|
||||
UnusedStoreEliminator::Operation const& _covering
|
||||
) const
|
||||
{
|
||||
if (_covered.location != _covering.location)
|
||||
return false;
|
||||
if (
|
||||
(_covered.start && _covered.start == _covering.start) &&
|
||||
(_covered.length && _covered.length == _covering.length)
|
||||
)
|
||||
return true;
|
||||
if (_covered.location == Location::Memory)
|
||||
{
|
||||
KnowledgeBase knowledge(m_dialect, [this](YulString _var) { return util::valueOrNullptr(m_ssaValues, _var); });
|
||||
|
||||
// if (_covered.length && knowledge.knownToBeZero(*_covered.length))
|
||||
// return true;
|
||||
if (_covered.length && knowledge.knownToBeZero(*_covered.length))
|
||||
return true;
|
||||
|
||||
// // Condition (i = cover_i_ng, e = cover_e_d):
|
||||
// // i.start <= e.start && e.start + e.length <= i.start + i.length
|
||||
// if (!_covered.start || !_covering.start || !_covered.length || !_covering.length)
|
||||
// return false;
|
||||
// optional<u256> coveredLength = knowledge.valueIfKnownConstant(*_covered.length);
|
||||
// optional<u256> coveringLength = knowledge.valueIfKnownConstant(*_covering.length);
|
||||
// if (knowledge.knownToBeEqual(*_covered.start, *_covering.start))
|
||||
// if (coveredLength && coveringLength && *coveredLength <= *coveringLength)
|
||||
// return true;
|
||||
// optional<u256> coveredStart = knowledge.valueIfKnownConstant(*_covered.start);
|
||||
// optional<u256> coveringStart = knowledge.valueIfKnownConstant(*_covering.start);
|
||||
// if (coveredStart && coveringStart && coveredLength && coveringLength)
|
||||
// if (
|
||||
// *coveringStart <= *coveredStart &&
|
||||
// *coveringStart + *coveringLength >= *coveringStart && // no overflow
|
||||
// *coveredStart + *coveredLength >= *coveredStart && // no overflow
|
||||
// *coveredStart + *coveredLength <= *coveringStart + *coveringLength
|
||||
// )
|
||||
// return true;
|
||||
// Condition (i = cover_i_ng, e = cover_e_d):
|
||||
// i.start <= e.start && e.start + e.length <= i.start + i.length
|
||||
if (!_covered.start || !_covering.start || !_covered.length || !_covering.length)
|
||||
return false;
|
||||
optional<u256> coveredLength = knowledge.valueIfKnownConstant(*_covered.length);
|
||||
optional<u256> coveringLength = knowledge.valueIfKnownConstant(*_covering.length);
|
||||
if (knowledge.knownToBeEqual(*_covered.start, *_covering.start))
|
||||
if (coveredLength && coveringLength && *coveredLength <= *coveringLength)
|
||||
return true;
|
||||
optional<u256> coveredStart = knowledge.valueIfKnownConstant(*_covered.start);
|
||||
optional<u256> coveringStart = knowledge.valueIfKnownConstant(*_covering.start);
|
||||
if (coveredStart && coveringStart && coveredLength && coveringLength)
|
||||
if (
|
||||
*coveringStart <= *coveredStart &&
|
||||
*coveringStart + *coveringLength >= *coveringStart && // no overflow
|
||||
*coveredStart + *coveredLength >= *coveredStart && // no overflow
|
||||
*coveredStart + *coveredLength <= *coveringStart + *coveringLength
|
||||
)
|
||||
return true;
|
||||
|
||||
// // TODO for this we probably need a non-overflow assumption as above.
|
||||
// // Condition (i = cover_i_ng, e = cover_e_d):
|
||||
// // i.start <= e.start && e.start + e.length <= i.start + i.length
|
||||
// }
|
||||
// return false;
|
||||
//}
|
||||
// TODO for this we probably need a non-overflow assumption as above.
|
||||
// Condition (i = cover_i_ng, e = cover_e_d):
|
||||
// i.start <= e.start && e.start + e.length <= i.start + i.length
|
||||
}
|
||||
return false;
|
||||
}
|
||||
|
||||
//void UnusedStoreEliminator::changeUndecidedTo(
|
||||
// State _newState,
|
||||
// optional<UnusedStoreEliminator::Location> _onlyLocation)
|
||||
//{
|
||||
// for (auto& [statement, state]: m_activeStores[YulString{}])
|
||||
// if (
|
||||
// state == State::Undecided &&
|
||||
// (_onlyLocation == nullopt || *_onlyLocation == m_storeOperations.at(statement).location)
|
||||
// )
|
||||
// state = _newState;
|
||||
//}
|
||||
void UnusedStoreEliminator::markActiveAsUsed(
|
||||
optional<UnusedStoreEliminator::Location> _onlyLocation)
|
||||
{
|
||||
// TODO it might make sense to use YulString{"m"} and YulString{"s"} for memory and storage.
|
||||
// BUT: Could be both!
|
||||
for (Statement const* statement: m_activeStores[YulString{}])
|
||||
if (_onlyLocation == nullopt || *_onlyLocation == m_storeOperations.at(statement).location)
|
||||
m_usedStores.insert(statement);
|
||||
// TODO and remove from active
|
||||
}
|
||||
|
||||
//optional<YulString> UnusedStoreEliminator::identifierNameIfSSA(Expression const& _expression) const
|
||||
//{
|
||||
// if (Identifier const* identifier = get_if<Identifier>(&_expression))
|
||||
// if (m_ssaValues.count(identifier->name))
|
||||
// return {identifier->name};
|
||||
// return nullopt;
|
||||
//}
|
||||
void UnusedStoreEliminator::changeUndecidedTo(
|
||||
State _newState,
|
||||
optional<UnusedStoreEliminator::Location> _onlyLocation)
|
||||
{
|
||||
for (auto& [statement, state]: m_activeStores[YulString{}])
|
||||
if (
|
||||
state == State::Undecided &&
|
||||
(_onlyLocation == nullopt || *_onlyLocation == m_storeOperations.at(statement).location)
|
||||
)
|
||||
state = _newState;
|
||||
}
|
||||
|
||||
//void UnusedStoreEliminator::scheduleUnusedForDeletion()
|
||||
//{
|
||||
// for (auto const& [statement, state]: m_activeStores[YulString{}])
|
||||
// if (state == State::Unused)
|
||||
// m_pendingRemovals.insert(statement);
|
||||
//}
|
||||
optional<YulString> UnusedStoreEliminator::identifierNameIfSSA(Expression const& _expression) const
|
||||
{
|
||||
if (Identifier const* identifier = get_if<Identifier>(&_expression))
|
||||
if (m_ssaValues.count(identifier->name))
|
||||
return {identifier->name};
|
||||
return nullopt;
|
||||
}
|
||||
|
||||
void UnusedStoreEliminator::scheduleUnusedForDeletion()
|
||||
{
|
||||
for (auto const& [statement, state]: m_activeStores[YulString{}])
|
||||
if (state == State::Unused)
|
||||
m_pendingRemovals.insert(statement);
|
||||
}
|
||||
|
||||
@ -70,57 +70,58 @@ public:
|
||||
bool// _ignoreMemory
|
||||
):
|
||||
UnusedStoreBase(_dialect)//,
|
||||
// m_ignoreMemory(_ignoreMemory),
|
||||
// m_functionSideEffects(_functionSideEffects),
|
||||
// m_controlFlowSideEffects(_controlFlowSideEffects),
|
||||
// m_ssaValues(_ssaValues)
|
||||
m_ignoreMemory(_ignoreMemory),
|
||||
m_functionSideEffects(_functionSideEffects),
|
||||
m_controlFlowSideEffects(_controlFlowSideEffects),
|
||||
m_ssaValues(_ssaValues)
|
||||
{}
|
||||
|
||||
// using UnusedStoreBase::operator();
|
||||
// void operator()(FunctionCall const& _functionCall) override;
|
||||
// void operator()(FunctionDefinition const&) override;
|
||||
// void operator()(Leave const&) override;
|
||||
using UnusedStoreBase::operator();
|
||||
void operator()(FunctionCall const& _functionCall) override;
|
||||
void operator()(FunctionDefinition const&) override;
|
||||
void operator()(Leave const&) override;
|
||||
|
||||
// using UnusedStoreBase::visit;
|
||||
// void visit(Statement const& _statement) override;
|
||||
using UnusedStoreBase::visit;
|
||||
void visit(Statement const& _statement) override;
|
||||
|
||||
// using Location = evmasm::SemanticInformation::Location;
|
||||
// using Effect = evmasm::SemanticInformation::Effect;
|
||||
// struct Operation
|
||||
// {
|
||||
// Location location;
|
||||
// Effect effect;
|
||||
// /// Start of affected area. Unknown if not provided.
|
||||
// std::optional<YulString> start;
|
||||
// /// Length of affected area, unknown if not provided.
|
||||
// /// Unused for storage.
|
||||
// std::optional<YulString> length;
|
||||
// };
|
||||
using Location = evmasm::SemanticInformation::Location;
|
||||
using Effect = evmasm::SemanticInformation::Effect;
|
||||
struct Operation
|
||||
{
|
||||
Location location;
|
||||
Effect effect;
|
||||
/// Start of affected area. Unknown if not provided.
|
||||
std::optional<YulString> start;
|
||||
/// Length of affected area, unknown if not provided.
|
||||
/// Unused for storage.
|
||||
std::optional<YulString> length;
|
||||
};
|
||||
|
||||
private:
|
||||
void shortcutNestedLoop(ActiveStores const&) override
|
||||
{
|
||||
// We might only need to do this for newly introduced stores in the loop.
|
||||
// changeUndecidedTo(State::Used);
|
||||
changeUndecidedTo(State::Used);
|
||||
}
|
||||
// void finalizeFunctionDefinition(FunctionDefinition const&) override;
|
||||
void finalizeFunctionDefinition(FunctionDefinition const&) override;
|
||||
|
||||
// std::vector<Operation> operationsFromFunctionCall(FunctionCall const& _functionCall) const;
|
||||
// void applyOperation(Operation const& _operation);
|
||||
// bool knownUnrelated(Operation const& _op1, Operation const& _op2) const;
|
||||
// bool knownCovered(Operation const& _covered, Operation const& _covering) const;
|
||||
std::vector<Operation> operationsFromFunctionCall(FunctionCall const& _functionCall) const;
|
||||
void applyOperation(Operation const& _operation);
|
||||
bool knownUnrelated(Operation const& _op1, Operation const& _op2) const;
|
||||
bool knownCovered(Operation const& _covered, Operation const& _covering) const;
|
||||
|
||||
// void changeUndecidedTo(State _newState, std::optional<Location> _onlyLocation = std::nullopt);
|
||||
// void scheduleUnusedForDeletion();
|
||||
void markActiveAsUsed(std::optional<Location> _onlyLocation = std::nullopt);
|
||||
void clearActive(std::optional<Location> _onlyLocation = std::nullopt);
|
||||
void scheduleUnusedForDeletion();
|
||||
|
||||
// std::optional<YulString> identifierNameIfSSA(Expression const& _expression) const;
|
||||
std::optional<YulString> identifierNameIfSSA(Expression const& _expression) const;
|
||||
|
||||
// bool const m_ignoreMemory;
|
||||
// std::map<YulString, SideEffects> const& m_functionSideEffects;
|
||||
// std::map<YulString, ControlFlowSideEffects> m_controlFlowSideEffects;
|
||||
// std::map<YulString, AssignedValue> const& m_ssaValues;
|
||||
bool const m_ignoreMemory;
|
||||
std::map<YulString, SideEffects> const& m_functionSideEffects;
|
||||
std::map<YulString, ControlFlowSideEffects> m_controlFlowSideEffects;
|
||||
std::map<YulString, AssignedValue> const& m_ssaValues;
|
||||
|
||||
// std::map<Statement const*, Operation> m_storeOperations;
|
||||
std::map<Statement const*, Operation> m_storeOperations;
|
||||
};
|
||||
|
||||
}
|
||||
|
||||
@ -0,0 +1,21 @@
|
||||
{
|
||||
let a := calldataload(0)
|
||||
if calldataload(1) {
|
||||
// this can be removed
|
||||
a := 2
|
||||
revert(0, 0)
|
||||
}
|
||||
sstore(0, a)
|
||||
}
|
||||
// ----
|
||||
// step: unusedAssignEliminator
|
||||
//
|
||||
// {
|
||||
// let a := calldataload(0)
|
||||
// if calldataload(1)
|
||||
// {
|
||||
// a := 2
|
||||
// revert(0, 0)
|
||||
// }
|
||||
// sstore(0, a)
|
||||
// }
|
||||
Loading…
Reference in New Issue
Block a user