cerc-io/solidity
11
0
Fork 0
mirror of https://github.com/ethereum/solidity synced 2023-10-03 13:03:40 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Free variables directly after visiting RHS of Variable Declarations during EVMCodeTransform.

Browse Source
This commit is contained in:
Daniel Kirchner
2020-07-13 17:36:15 +02:00
parent a783449195
commit def0ebbb3e
4 changed files with 75 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files
libyul/backends/evm/EVMCodeTransform.cpp
+8 -6
View File
@@ -141,7 +141,7 @@ bool CodeTransform::unreferenced(Scope::Variable const& _var) const
return !m_context->variableReferences.count(&_var) || m_context->variableReferences[&_var] == 0;
}
void CodeTransform::freeUnusedVariables()
void CodeTransform::freeUnusedVariables(bool _popUnusedSlotsAtStackTop)
{
if (!m_allowStackOpt)
return;
@@ -154,11 +154,12 @@ void CodeTransform::freeUnusedVariables()
deleteVariable(var);
}
while (m_unusedStackSlots.count(m_assembly.stackHeight() - 1))
{
yulAssert(m_unusedStackSlots.erase(m_assembly.stackHeight() - 1), "");
m_assembly.appendInstruction(evmasm::Instruction::POP);
}
if (_popUnusedSlotsAtStackTop)
while (m_unusedStackSlots.count(m_assembly.stackHeight() - 1))
{
yulAssert(m_unusedStackSlots.erase(m_assembly.stackHeight() - 1), "");
m_assembly.appendInstruction(evmasm::Instruction::POP);
}
}
void CodeTransform::deleteVariable(Scope::Variable const& _var)
@@ -181,6 +182,7 @@ void CodeTransform::operator()(VariableDeclaration const& _varDecl)
{
std::visit(*this, *_varDecl.value);
expectDeposit(static_cast<int>(numVariables), static_cast<int>(heightAtStart));
freeUnusedVariables(false);
}
else
{
libyul/backends/evm/EVMCodeTransform.h
+3 -2
View File
@@ -161,8 +161,9 @@ protected:
bool unreferenced(Scope::Variable const& _var) const;
/// Marks slots of variables that are not used anymore
/// and were defined in the current scope for reuse.
/// Also POPs unused topmost stack slots.
void freeUnusedVariables();
/// Also POPs unused topmost stack slots,
/// unless @a _popUnusedSlotsAtStackTop is set to false.
void freeUnusedVariables(bool _popUnusedSlotsAtStackTop = true);
/// Marks the stack slot of @a _var to be reused.
void deleteVariable(Scope::Variable const& _var);