solidity/libjulia/optimiser/FullInliner.cpp
2018-10-01 13:10:10 +02:00

265 lines
7.9 KiB
C++

/*
This file is part of solidity.
solidity is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
solidity is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with solidity. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* Optimiser component that performs function inlining for arbitrary functions.
*/
#include <libjulia/optimiser/FullInliner.h>
#include <libjulia/optimiser/ASTCopier.h>
#include <libjulia/optimiser/ASTWalker.h>
#include <libjulia/optimiser/NameCollector.h>
#include <libjulia/optimiser/Semantics.h>
#include <libjulia/Exceptions.h>
#include <libsolidity/inlineasm/AsmData.h>
#include <libdevcore/CommonData.h>
#include <boost/range/adaptor/reversed.hpp>
using namespace std;
using namespace dev;
using namespace dev::julia;
using namespace dev::solidity;
FullInliner::FullInliner(Block& _ast):
m_ast(_ast)
{
assertThrow(m_ast.statements.size() >= 1, OptimizerException, "");
assertThrow(m_ast.statements.front().type() == typeid(Block), OptimizerException, "");
m_nameDispenser.m_usedNames = NameCollector(m_ast).names();
for (size_t i = 1; i < m_ast.statements.size(); ++i)
{
assertThrow(m_ast.statements.at(i).type() == typeid(FunctionDefinition), OptimizerException, "");
FunctionDefinition& fun = boost::get<FunctionDefinition>(m_ast.statements.at(i));
m_functions[fun.name] = &fun;
m_functionsToVisit.insert(&fun);
}
}
void FullInliner::run()
{
assertThrow(m_ast.statements[0].type() == typeid(Block), OptimizerException, "");
InlineModifier(*this, m_nameDispenser, "").visit(m_ast.statements[0]);
while (!m_functionsToVisit.empty())
handleFunction(**m_functionsToVisit.begin());
}
void FullInliner::handleFunction(FunctionDefinition& _fun)
{
if (!m_functionsToVisit.count(&_fun))
return;
m_functionsToVisit.erase(&_fun);
(InlineModifier(*this, m_nameDispenser, _fun.name))(_fun.body);
}
void InlineModifier::operator()(FunctionalInstruction& _instruction)
{
visitArguments(_instruction.arguments);
}
void InlineModifier::operator()(FunctionCall&)
{
assertThrow(false, OptimizerException, "Should be handled in visit() instead.");
}
void InlineModifier::operator()(ForLoop& _loop)
{
(*this)(_loop.pre);
// Do not visit the condition because we cannot inline there.
(*this)(_loop.post);
(*this)(_loop.body);
}
void InlineModifier::operator()(Block& _block)
{
vector<Statement> saved;
saved.swap(m_statementsToPrefix);
// This is only used if needed to minimize the number of move operations.
vector<Statement> modifiedStatements;
for (size_t i = 0; i < _block.statements.size(); ++i)
{
visit(_block.statements.at(i));
if (!m_statementsToPrefix.empty())
{
if (modifiedStatements.empty())
std::move(
_block.statements.begin(),
_block.statements.begin() + i,
back_inserter(modifiedStatements)
);
modifiedStatements += std::move(m_statementsToPrefix);
m_statementsToPrefix.clear();
}
if (!modifiedStatements.empty())
modifiedStatements.emplace_back(std::move(_block.statements[i]));
}
if (!modifiedStatements.empty())
_block.statements = std::move(modifiedStatements);
saved.swap(m_statementsToPrefix);
}
void InlineModifier::visit(Expression& _expression)
{
if (_expression.type() != typeid(FunctionCall))
return ASTModifier::visit(_expression);
FunctionCall& funCall = boost::get<FunctionCall>(_expression);
FunctionDefinition& fun = m_driver.function(funCall.functionName.name);
m_driver.handleFunction(fun);
// TODO: Insert good heuristic here. Perhaps implement that inside the driver.
bool doInline = funCall.functionName.name != m_currentFunction;
if (fun.returnVariables.size() > 1)
doInline = false;
{
vector<string> argNames;
vector<string> argTypes;
for (auto const& arg: fun.parameters)
{
argNames.push_back(fun.name + "_" + arg.name);
argTypes.push_back(arg.type);
}
visitArguments(funCall.arguments, argNames, argTypes, doInline);
}
if (!doInline)
return;
map<string, string> variableReplacements;
for (size_t i = 0; i < funCall.arguments.size(); ++i)
variableReplacements[fun.parameters[i].name] = boost::get<Identifier>(funCall.arguments[i]).name;
if (fun.returnVariables.empty())
_expression = noop(funCall.location);
else
{
string returnVariable = fun.returnVariables[0].name;
variableReplacements[returnVariable] = newName(fun.name + "_" + returnVariable);
m_statementsToPrefix.emplace_back(VariableDeclaration{
funCall.location,
{{funCall.location, variableReplacements[returnVariable], fun.returnVariables[0].type}},
{}
});
_expression = Identifier{funCall.location, variableReplacements[returnVariable]};
}
m_statementsToPrefix.emplace_back(BodyCopier(m_nameDispenser, fun.name + "_", variableReplacements)(fun.body));
}
void InlineModifier::visit(Statement& _statement)
{
ASTModifier::visit(_statement);
// Replace pop(0) expression statemets (and others) by empty blocks.
if (_statement.type() == typeid(ExpressionStatement))
{
ExpressionStatement& expSt = boost::get<ExpressionStatement>(_statement);
if (expSt.expression.type() == typeid(FunctionalInstruction))
{
FunctionalInstruction& funInstr = boost::get<FunctionalInstruction>(expSt.expression);
if (funInstr.instruction == solidity::Instruction::POP)
if (MovableChecker(funInstr.arguments.at(0)).movable())
_statement = Block{expSt.location, {}};
}
}
}
void InlineModifier::visitArguments(
vector<Expression>& _arguments,
vector<string> const& _nameHints,
vector<string> const& _types,
bool _moveToFront
)
{
// If one of the elements moves parts to the front, all other elements right of it
// also have to be moved to the front to keep the order of evaluation.
vector<Statement> prefix;
for (size_t i = 0; i < _arguments.size(); ++i)
{
auto& arg = _arguments[i];
// TODO optimize vector operations, check that it actually moves
auto internalPrefix = visitRecursively(arg);
if (!internalPrefix.empty())
{
_moveToFront = true;
// We go through the arguments left to right, so we have to invert
// the prefixes.
prefix = std::move(internalPrefix) + std::move(prefix);
}
else if (_moveToFront)
{
auto location = locationOf(arg);
string var = newName(i < _nameHints.size() ? _nameHints[i] : "");
prefix.emplace(prefix.begin(), VariableDeclaration{
location,
{{TypedName{location, var, i < _types.size() ? _types[i] : ""}}},
make_shared<Expression>(std::move(arg))
});
arg = Identifier{location, var};
}
}
m_statementsToPrefix += std::move(prefix);
}
vector<Statement> InlineModifier::visitRecursively(Expression& _expression)
{
vector<Statement> saved;
saved.swap(m_statementsToPrefix);
visit(_expression);
saved.swap(m_statementsToPrefix);
return saved;
}
string InlineModifier::newName(string const& _prefix)
{
return m_nameDispenser.newName(_prefix);
}
Expression InlineModifier::noop(SourceLocation const& _location)
{
return FunctionalInstruction{_location, solidity::Instruction::POP, {
Literal{_location, assembly::LiteralKind::Number, "0", ""}
}};
}
Statement BodyCopier::operator()(VariableDeclaration const& _varDecl)
{
for (auto const& var: _varDecl.variables)
m_variableReplacements[var.name] = m_nameDispenser.newName(m_varNamePrefix + var.name);
return ASTCopier::operator()(_varDecl);
}
Statement BodyCopier::operator()(FunctionDefinition const& _funDef)
{
assertThrow(false, OptimizerException, "Function hoisting has to be done before function inlining.");
return _funDef;
}
string BodyCopier::translateIdentifier(string const& _name)
{
if (m_variableReplacements.count(_name))
return m_variableReplacements.at(_name);
else
return _name;
}