Unused store eliminator.

This commit is contained in:
chriseth 2021-05-05 18:02:35 +02:00
parent 921c4fd5e5
commit 4f02be110c
86 changed files with 1274 additions and 159 deletions

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@ -7,6 +7,7 @@ Language Features:
Compiler Features:
* JSON-AST: Added selector field for errors and events.
* Peephole Optimizer: Optimize comparisons in front of conditional jumps and conditional jumps across a single unconditional jump.
* Yul Optimizer: Remove ``sstore`` and ``mstore`` operations that are never read from.
Bugfixes:
* Yul IR Code Generation: Optimize embedded creation code with correct settings. This fixes potential mismatches between the constructor code of a contract compiled in isolation and the bytecode in ``type(C).creationCode``, resp. the bytecode used for ``new C(...)``.

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@ -121,7 +121,9 @@ vector<SemanticInformation::Operation> SemanticInformation::readWriteOperations(
Location::Memory,
Effect::Write,
paramCount - 2,
paramCount - 1,
// Length is in paramCount - 1, but it is only a max length,
// there is no guarantee that the full area is written to.
{},
{}
});
return operations;

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@ -55,7 +55,7 @@ struct OptimiserSettings
"xa[rul]" // Prune a bit more in SSA
"xa[r]cL" // Turn into SSA again and simplify
"gvif" // Run full inliner
"CTUca[r]LsTFOtfDnca[r]Iulc" // SSA plus simplify
"CTUca[r]LSsTFOtfDnca[r]Iulc" // SSA plus simplify
"]"
"jmul[jul] VcTOcul jmul"; // Make source short and pretty

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@ -179,6 +179,8 @@ add_library(yul
optimiser/UnusedAssignEliminator.h
optimiser/UnusedStoreBase.cpp
optimiser/UnusedStoreBase.h
optimiser/UnusedStoreEliminator.cpp
optimiser/UnusedStoreEliminator.h
optimiser/Rematerialiser.cpp
optimiser/Rematerialiser.h
optimiser/SMTSolver.cpp

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@ -57,6 +57,7 @@
#include <libyul/optimiser/StructuralSimplifier.h>
#include <libyul/optimiser/SyntacticalEquality.h>
#include <libyul/optimiser/UnusedAssignEliminator.h>
#include <libyul/optimiser/UnusedStoreEliminator.h>
#include <libyul/optimiser/VarNameCleaner.h>
#include <libyul/optimiser/LoadResolver.h>
#include <libyul/optimiser/LoopInvariantCodeMotion.h>
@ -222,6 +223,7 @@ map<string, unique_ptr<OptimiserStep>> const& OptimiserSuite::allSteps()
LoadResolver,
LoopInvariantCodeMotion,
UnusedAssignEliminator,
UnusedStoreEliminator,
ReasoningBasedSimplifier,
Rematerialiser,
SSAReverser,
@ -264,6 +266,7 @@ map<string, char> const& OptimiserSuite::stepNameToAbbreviationMap()
{LoopInvariantCodeMotion::name, 'M'},
{ReasoningBasedSimplifier::name, 'R'},
{UnusedAssignEliminator::name, 'r'},
{UnusedStoreEliminator::name, 'S'},
{Rematerialiser::name, 'm'},
{SSAReverser::name, 'V'},
{SSATransform::name, 'a'},

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@ -0,0 +1,379 @@
/*
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/>.
*/
// SPDX-License-Identifier: GPL-3.0
/**
* Optimiser component that removes stores to memory and storage slots that are not used
* or overwritten later on.
*/
#include <libyul/optimiser/UnusedStoreEliminator.h>
#include <libyul/optimiser/Semantics.h>
#include <libyul/optimiser/OptimizerUtilities.h>
#include <libyul/optimiser/Semantics.h>
#include <libyul/optimiser/SSAValueTracker.h>
#include <libyul/optimiser/DataFlowAnalyzer.h>
#include <libyul/optimiser/KnowledgeBase.h>
#include <libyul/ControlFlowSideEffectsCollector.h>
#include <libyul/AST.h>
#include <libsolutil/CommonData.h>
#include <libevmasm/Instruction.h>
#include <libevmasm/SemanticInformation.h>
#include <range/v3/algorithm/all_of.hpp>
using namespace std;
using namespace solidity;
using namespace solidity::yul;
/// Variable names for special constants that can never appear in actual Yul code.
static string const zero{"@ 0"};
static string const one{"@ 1"};
static string const thirtyTwo{"@ 32"};
void UnusedStoreEliminator::run(OptimiserStepContext& _context, Block& _ast)
{
map<YulString, SideEffects> functionSideEffects = SideEffectsPropagator::sideEffects(
_context.dialect,
CallGraphGenerator::callGraph(_ast)
);
SSAValueTracker ssaValues;
ssaValues(_ast);
map<YulString, AssignedValue> values;
for (auto const& [name, expression]: ssaValues.values())
values[name] = AssignedValue{expression, {}};
Expression const zeroLiteral{Literal{{}, LiteralKind::Number, YulString{"0"}, {}}};
Expression const oneLiteral{Literal{{}, LiteralKind::Number, YulString{"1"}, {}}};
Expression const thirtyTwoLiteral{Literal{{}, LiteralKind::Number, YulString{"32"}, {}}};
values[YulString{zero}] = AssignedValue{&zeroLiteral, {}};
values[YulString{one}] = AssignedValue{&oneLiteral, {}};
values[YulString{thirtyTwo}] = AssignedValue{&thirtyTwoLiteral, {}};
bool const ignoreMemory = MSizeFinder::containsMSize(_context.dialect, _ast);
UnusedStoreEliminator rse{
_context.dialect,
functionSideEffects,
ControlFlowSideEffectsCollector{_context.dialect, _ast}.functionSideEffectsNamed(),
values,
ignoreMemory
};
rse(_ast);
rse.changeUndecidedTo(State::Unused, Location::Memory);
rse.changeUndecidedTo(State::Used, Location::Storage);
rse.scheduleUnusedForDeletion();
StatementRemover remover(rse.m_pendingRemovals);
remover(_ast);
}
void UnusedStoreEliminator::operator()(FunctionCall const& _functionCall)
{
UnusedStoreBase::operator()(_functionCall);
for (Operation const& op: operationsFromFunctionCall(_functionCall))
applyOperation(op);
ControlFlowSideEffects sideEffects;
if (auto builtin = m_dialect.builtin(_functionCall.functionName.name))
sideEffects = builtin->controlFlowSideEffects;
else
sideEffects = m_controlFlowSideEffects.at(_functionCall.functionName.name);
if (!sideEffects.canContinue)
{
changeUndecidedTo(State::Unused, Location::Memory);
changeUndecidedTo(sideEffects.canTerminate ? State::Used : State::Unused, Location::Storage);
}
}
void UnusedStoreEliminator::operator()(FunctionDefinition const& _functionDefinition)
{
ScopedSaveAndRestore storeOperations(m_storeOperations, {});
UnusedStoreBase::operator()(_functionDefinition);
}
void UnusedStoreEliminator::operator()(Leave const&)
{
changeUndecidedTo(State::Used);
}
void UnusedStoreEliminator::visit(Statement const& _statement)
{
using evmasm::Instruction;
UnusedStoreBase::visit(_statement);
auto const* exprStatement = get_if<ExpressionStatement>(&_statement);
if (!exprStatement)
return;
FunctionCall const* funCall = get_if<FunctionCall>(&exprStatement->expression);
yulAssert(funCall);
optional<Instruction> instruction = toEVMInstruction(m_dialect, funCall->functionName.name);
if (!instruction)
return;
if (!ranges::all_of(funCall->arguments, [](Expression const& _expr) -> bool {
return get_if<Identifier>(&_expr) || get_if<Literal>(&_expr);
}))
return;
// We determine if this is a store instruction without additional side-effects
// both by querying a combination of semantic information and by listing the instructions.
// This way the assert below should be triggered on any change.
using evmasm::SemanticInformation;
bool isStorageWrite = (*instruction == Instruction::SSTORE);
bool isMemoryWrite =
*instruction == Instruction::EXTCODECOPY ||
*instruction == Instruction::CODECOPY ||
*instruction == Instruction::CALLDATACOPY ||
*instruction == Instruction::RETURNDATACOPY ||
*instruction == Instruction::MSTORE ||
*instruction == Instruction::MSTORE8;
bool isCandidateForRemoval =
SemanticInformation::otherState(*instruction) != SemanticInformation::Write && (
SemanticInformation::storage(*instruction) == SemanticInformation::Write ||
(!m_ignoreMemory && SemanticInformation::memory(*instruction) == SemanticInformation::Write)
);
yulAssert(isCandidateForRemoval == (isStorageWrite || (!m_ignoreMemory && isMemoryWrite)));
if (isCandidateForRemoval)
{
m_stores[YulString{}].insert({&_statement, State::Undecided});
vector<Operation> operations = operationsFromFunctionCall(*funCall);
yulAssert(operations.size() == 1, "");
m_storeOperations[&_statement] = move(operations.front());
}
}
void UnusedStoreEliminator::finalizeFunctionDefinition(FunctionDefinition const&)
{
changeUndecidedTo(State::Used);
scheduleUnusedForDeletion();
}
vector<UnusedStoreEliminator::Operation> UnusedStoreEliminator::operationsFromFunctionCall(
FunctionCall const& _functionCall
) const
{
using evmasm::Instruction;
YulString functionName = _functionCall.functionName.name;
SideEffects sideEffects;
if (BuiltinFunction const* f = m_dialect.builtin(functionName))
sideEffects = f->sideEffects;
else
sideEffects = m_functionSideEffects.at(functionName);
optional<Instruction> instruction = toEVMInstruction(m_dialect, functionName);
if (!instruction)
{
vector<Operation> result;
// Unknown read is worse than unknown write.
if (sideEffects.memory != SideEffects::Effect::None)
result.emplace_back(Operation{Location::Memory, Effect::Read, {}, {}});
if (sideEffects.storage != SideEffects::Effect::None)
result.emplace_back(Operation{Location::Storage, Effect::Read, {}, {}});
return result;
}
using evmasm::SemanticInformation;
return util::applyMap(
SemanticInformation::readWriteOperations(*instruction),
[&](SemanticInformation::Operation const& _op) -> Operation
{
yulAssert(!(_op.lengthParameter && _op.lengthConstant));
yulAssert(_op.effect != Effect::None);
Operation ourOp{_op.location, _op.effect, {}, {}};
if (_op.startParameter)
ourOp.start = identifierNameIfSSA(_functionCall.arguments.at(*_op.startParameter));
if (_op.lengthParameter)
ourOp.length = identifierNameIfSSA(_functionCall.arguments.at(*_op.lengthParameter));
if (_op.lengthConstant)
switch (*_op.lengthConstant)
{
case 1: ourOp.length = YulString(one); break;
case 32: ourOp.length = YulString(thirtyTwo); break;
default: yulAssert(false);
}
return ourOp;
}
);
}
void UnusedStoreEliminator::applyOperation(UnusedStoreEliminator::Operation const& _operation)
{
for (auto& [statement, state]: m_stores[YulString{}])
if (state == State::Undecided)
{
Operation const& storeOperation = m_storeOperations.at(statement);
if (_operation.effect == Effect::Read && !knownUnrelated(storeOperation, _operation))
state = State::Used;
else if (_operation.effect == Effect::Write && knownCovered(storeOperation, _operation))
state = State::Unused;
}
}
bool UnusedStoreEliminator::knownUnrelated(
UnusedStoreEliminator::Operation const& _op1,
UnusedStoreEliminator::Operation const& _op2
) const
{
KnowledgeBase knowledge(m_dialect, m_ssaValues);
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 && _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;
}
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, m_ssaValues);
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;
// 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_stores[YulString{}])
if (
state == State::Undecided &&
(_onlyLocation == nullopt || *_onlyLocation == m_storeOperations.at(statement).location)
)
state = _newState;
}
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_stores[YulString{}])
if (state == State::Unused)
m_pendingRemovals.insert(statement);
}

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@ -0,0 +1,119 @@
/*
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/>.
*/
// SPDX-License-Identifier: GPL-3.0
/**
* Optimiser component that removes stores to memory and storage slots that are not used
* or overwritten later on.
*/
#pragma once
#include <libyul/ASTForward.h>
#include <libyul/optimiser/ASTWalker.h>
#include <libyul/optimiser/OptimiserStep.h>
#include <libyul/optimiser/Semantics.h>
#include <libyul/optimiser/UnusedStoreBase.h>
#include <libevmasm/SemanticInformation.h>
#include <map>
#include <vector>
namespace solidity::yul
{
struct Dialect;
struct AssignedValue;
/**
* Optimizer component that removes sstore statements if they
* are overwritten in all code paths or never read from.
*
* The m_store member of UnusedStoreBase is only used with the empty yul string
* as key in the first dimension.
*
* Best run in SSA form.
*
* Prerequisite: Disambiguator, ForLoopInitRewriter.
*/
class UnusedStoreEliminator: public UnusedStoreBase
{
public:
static constexpr char const* name{"UnusedStoreEliminator"};
static void run(OptimiserStepContext& _context, Block& _ast);
explicit UnusedStoreEliminator(
Dialect const& _dialect,
std::map<YulString, SideEffects> const& _functionSideEffects,
std::map<YulString, ControlFlowSideEffects> _controlFlowSideEffects,
std::map<YulString, AssignedValue> const& _ssaValues,
bool _ignoreMemory
):
UnusedStoreBase(_dialect),
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::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;
};
private:
void shortcutNestedLoop(TrackedStores const&) override
{
// We might only need to do this for newly introduced stores in the loop.
changeUndecidedTo(State::Used);
}
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;
void changeUndecidedTo(State _newState, std::optional<Location> _onlyLocation = std::nullopt);
void scheduleUnusedForDeletion();
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;
std::map<Statement const*, Operation> m_storeOperations;
};
}

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@ -27,7 +27,6 @@ object "C_12" {
code {
{
/// @src 0:61:418 "contract C {..."
mstore(64, memoryguard(0x80))
if callvalue() { revert(0, 0) }
/// @src 0:279:410 "assembly {..."
sstore(0, 0x1000000000000000000000000000000000000000000000)

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@ -201,16 +201,14 @@ object "C_6" {
code {
{
/// @src 0:60:101 "contract C {..."
let _1 := memoryguard(0x80)
mstore(64, _1)
if iszero(lt(calldatasize(), 4))
{
let _2 := 0
if eq(0x26121ff0, shr(224, calldataload(_2)))
let _1 := 0
if eq(0x26121ff0, shr(224, calldataload(_1)))
{
if callvalue() { revert(_2, _2) }
if slt(add(calldatasize(), not(3)), _2) { revert(_2, _2) }
return(_1, _2)
if callvalue() { revert(_1, _1) }
if slt(add(calldatasize(), not(3)), _1) { revert(_1, _1) }
return(memoryguard(0x80), _1)
}
}
revert(0, 0)

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@ -200,16 +200,14 @@ object "C_6" {
code {
{
/// @src 0:60:101
let _1 := memoryguard(0x80)
mstore(64, _1)
if iszero(lt(calldatasize(), 4))
{
let _2 := 0
if eq(0x26121ff0, shr(224, calldataload(_2)))
let _1 := 0
if eq(0x26121ff0, shr(224, calldataload(_1)))
{
if callvalue() { revert(_2, _2) }
if slt(add(calldatasize(), not(3)), _2) { revert(_2, _2) }
return(_1, _2)
if callvalue() { revert(_1, _1) }
if slt(add(calldatasize(), not(3)), _1) { revert(_1, _1) }
return(memoryguard(0x80), _1)
}
}
revert(0, 0)

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@ -189,16 +189,14 @@ object "C_6" {
object "C_6_deployed" {
code {
{
let _1 := memoryguard(0x80)
mstore(64, _1)
if iszero(lt(calldatasize(), 4))
{
let _2 := 0
if eq(0x26121ff0, shr(224, calldataload(_2)))
let _1 := 0
if eq(0x26121ff0, shr(224, calldataload(_1)))
{
if callvalue() { revert(_2, _2) }
if slt(add(calldatasize(), not(3)), _2) { revert(_2, _2) }
return(_1, _2)
if callvalue() { revert(_1, _1) }
if slt(add(calldatasize(), not(3)), _1) { revert(_1, _1) }
return(memoryguard(0x80), _1)
}
}
revert(0, 0)

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@ -95,7 +95,6 @@ object "C_2" {
code {
{
/// @src 0:265:278 "contract C {}"
mstore(64, memoryguard(0x80))
revert(0, 0)
}
}
@ -559,7 +558,6 @@ object "D_27" {
code {
{
/// @src 0:265:278 "contract C {}"
mstore(64, memoryguard(0x80))
revert(0, 0)
}
}

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@ -24,7 +24,6 @@ object "C_7" {
code {
{
/// @src 0:82:117 "contract C {..."
mstore(64, memoryguard(0x80))
revert(0, 0)
}
}
@ -58,7 +57,6 @@ object "D_10" {
code {
{
/// @src 0:118:137 "contract D is C {..."
mstore(64, memoryguard(0x80))
revert(0, 0)
}
}

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@ -24,7 +24,6 @@ object "C_3" {
code {
{
/// @src 0:82:95 "contract C {}"
mstore(64, memoryguard(0x80))
revert(0, 0)
}
}
@ -110,7 +109,6 @@ object "D_16" {
code {
{
/// @src 0:82:95 "contract C {}"
mstore(64, memoryguard(0x80))
revert(0, 0)
}
}

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@ -11,11 +11,7 @@ object "D_12" {
code {
{
/// @src 0:82:175 "contract D {..."
mstore(64, 128)
if callvalue() { revert(0, 0) }
/// @src 0:115:139 "assembly { mstore(0,0) }"
mstore(0, 0)
/// @src 0:82:175 "contract D {..."
let _1 := datasize("D_12_deployed")
codecopy(128, dataoffset("D_12_deployed"), _1)
return(128, _1)
@ -26,16 +22,14 @@ object "D_12" {
code {
{
/// @src 0:82:175 "contract D {..."
let _1 := memoryguard(0x80)
mstore(64, _1)
if iszero(lt(calldatasize(), 4))
{
let _2 := 0
if eq(0x26121ff0, shr(224, calldataload(_2)))
let _1 := 0
if eq(0x26121ff0, shr(224, calldataload(_1)))
{
if callvalue() { revert(_2, _2) }
if slt(add(calldatasize(), not(3)), _2) { revert(_2, _2) }
return(_1, _2)
if callvalue() { revert(_1, _1) }
if slt(add(calldatasize(), not(3)), _1) { revert(_1, _1) }
return(memoryguard(0x80), _1)
}
}
revert(0, 0)

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@ -24,7 +24,6 @@ object "D_8" {
code {
{
/// @src 0:82:166 "contract D {..."
mstore(64, 128)
if iszero(lt(calldatasize(), 4))
{
let _1 := 0
@ -32,8 +31,6 @@ object "D_8" {
{
if callvalue() { revert(_1, _1) }
if slt(add(calldatasize(), not(3)), _1) { revert(_1, _1) }
/// @src 0:134:158 "assembly { mstore(0,0) }"
mstore(/** @src 0:82:166 "contract D {..." */ _1, _1)
return(128, _1)
}
}

View File

@ -11,7 +11,6 @@ object "C_12" {
code {
{
/// @src 0:62:463 "contract C {..."
mstore(64, 128)
if callvalue() { revert(0, 0) }
/// @src 0:103:275 "assembly {..."
mstore(0, 100)
@ -27,10 +26,8 @@ object "C_12" {
code {
{
/// @src 0:62:463 "contract C {..."
mstore(64, 128)
if callvalue() { revert(0, 0) }
/// @src 0:317:454 "assembly {..."
mstore(0, 100)
sstore(0, 17385872270140913825666367956517731270094621555228275961425792378517567244498)
/// @src 0:62:463 "contract C {..."
stop()

View File

@ -24,7 +24,6 @@ object "C_7" {
code {
{
/// @src 0:62:285 "contract C {..."
mstore(64, 128)
if callvalue() { revert(0, 0) }
/// @src 0:109:277 "assembly {..."
mstore(0, 100)

View File

@ -1,8 +1,5 @@
{"contracts":{"C":{"C":{"evm":{"assembly":" /* \"C\":79:428 contract C... */
0xa0
dup1
0x40
mstore
jumpi(tag_6, callvalue)
0x1f
bytecodeSize
@ -438,9 +435,6 @@ sub_0: assembly {
}
"}}},"D":{"D":{"evm":{"assembly":" /* \"D\":91:166 contract D is C(3)... */
0xa0
dup1
0x40
mstore
jumpi(tag_6, callvalue)
0x1f
bytecodeSize
@ -514,13 +508,8 @@ tag_4:
tag_1:
/* \"C\":147:149 42 */
mstore(0x80, 0x2a)
/* \"D\":107:108 3 */
0x03
/* \"C\":203:219 stateVar = _init */
0x00
/* \"D\":91:166 contract D is C(3)... */
sstore
sub(shl(0xff, 0x01), 0x04)
/* \"D\":91:166 contract D is C(3)... */
dup2
sgt
0x01
@ -531,9 +520,7 @@ tag_1:
0x03
/* \"D\":91:166 contract D is C(3)... */
add
/* \"C\":203:219 stateVar = _init */
0x00
/* \"D\":91:166 contract D is C(3)... */
sstore
/* \"D\":113:164 constructor(int _init2)... */
jump\t// out
@ -541,17 +528,9 @@ tag_1:
tag_9:
pop
pop
shl(0xe0, 0x4e487b71)
/* \"C\":203:219 stateVar = _init */
0x00
/* \"D\":91:166 contract D is C(3)... */
mstore
mstore(0x00, shl(0xe0, 0x4e487b71))
mstore(0x04, 0x11)
0x24
/* \"C\":203:219 stateVar = _init */
0x00
/* \"D\":91:166 contract D is C(3)... */
revert
revert(0x00, 0x24)
stop
sub_0: assembly {

View File

@ -206,16 +206,14 @@ object \"C_6\" {
code {
{
/// @src 0:60:101 \"contract C {...\"
let _1 := memoryguard(0x80)
mstore(64, _1)
if iszero(lt(calldatasize(), 4))
{
let _2 := 0
if eq(0x26121ff0, shr(224, calldataload(_2)))
let _1 := 0
if eq(0x26121ff0, shr(224, calldataload(_1)))
{
if callvalue() { revert(_2, _2) }
if slt(add(calldatasize(), not(3)), _2) { revert(_2, _2) }
return(_1, _2)
if callvalue() { revert(_1, _1) }
if slt(add(calldatasize(), not(3)), _1) { revert(_1, _1) }
return(memoryguard(0x80), _1)
}
}
revert(0, 0)

View File

@ -205,16 +205,14 @@ object \"C_6\" {
code {
{
/// @src 0:60:101
let _1 := memoryguard(0x80)
mstore(64, _1)
if iszero(lt(calldatasize(), 4))
{
let _2 := 0
if eq(0x26121ff0, shr(224, calldataload(_2)))
let _1 := 0
if eq(0x26121ff0, shr(224, calldataload(_1)))
{
if callvalue() { revert(_2, _2) }
if slt(add(calldatasize(), not(3)), _2) { revert(_2, _2) }
return(_1, _2)
if callvalue() { revert(_1, _1) }
if slt(add(calldatasize(), not(3)), _1) { revert(_1, _1) }
return(memoryguard(0x80), _1)
}
}
revert(0, 0)

View File

@ -194,16 +194,14 @@ object \"C_6\" {
object \"C_6_deployed\" {
code {
{
let _1 := memoryguard(0x80)
mstore(64, _1)
if iszero(lt(calldatasize(), 4))
{
let _2 := 0
if eq(0x26121ff0, shr(224, calldataload(_2)))
let _1 := 0
if eq(0x26121ff0, shr(224, calldataload(_1)))
{
if callvalue() { revert(_2, _2) }
if slt(add(calldatasize(), not(3)), _2) { revert(_2, _2) }
return(_1, _2)
if callvalue() { revert(_1, _1) }
if slt(add(calldatasize(), not(3)), _1) { revert(_1, _1) }
return(memoryguard(0x80), _1)
}
}
revert(0, 0)

View File

@ -622,7 +622,6 @@ object \"C_54\" {
{
/// @src 0:79:435 \"contract C...\"
let _1 := memoryguard(0xa0)
mstore(64, _1)
if callvalue() { revert(0, 0) }
let programSize := datasize(\"C_54\")
let argSize := sub(codesize(), programSize)
@ -1469,7 +1468,6 @@ object \"D_72\" {
{
/// @src 1:91:166 \"contract D is C(3)...\"
let _1 := memoryguard(0xa0)
mstore(64, _1)
if callvalue() { revert(0, 0) }
let programSize := datasize(\"D_72\")
let argSize := sub(codesize(), programSize)
@ -1500,15 +1498,13 @@ object \"D_72\" {
/// @src 0:154:156 \"42\"
mstore(128, 0x2a)
/// @src 1:91:166 \"contract D is C(3)...\"
sstore(/** @src 0:210:226 \"stateVar = _init\" */ 0x00, /** @src 1:107:108 \"3\" */ 0x03)
/// @src 1:91:166 \"contract D is C(3)...\"
if and(1, sgt(var_init2, sub(shl(255, 1), 4)))
{
mstore(/** @src 0:210:226 \"stateVar = _init\" */ 0x00, /** @src 1:91:166 \"contract D is C(3)...\" */ shl(224, 0x4e487b71))
mstore(0, shl(224, 0x4e487b71))
mstore(4, 0x11)
revert(/** @src 0:210:226 \"stateVar = _init\" */ 0x00, /** @src 1:91:166 \"contract D is C(3)...\" */ 0x24)
revert(0, 0x24)
}
sstore(/** @src 0:210:226 \"stateVar = _init\" */ 0x00, /** @src 1:91:166 \"contract D is C(3)...\" */ add(/** @src 1:107:108 \"3\" */ 0x03, /** @src 1:91:166 \"contract D is C(3)...\" */ var_init2))
sstore(/** @src -1:-1:-1 */ 0, /** @src 1:91:166 \"contract D is C(3)...\" */ add(/** @src 1:107:108 \"3\" */ 0x03, /** @src 1:91:166 \"contract D is C(3)...\" */ var_init2))
}
}
/// @use-src 0:\"C\", 1:\"D\"

View File

@ -3,9 +3,6 @@
EVM assembly:
/* "viair_subobject_optimization/input.sol":61:668 contract C {... */
0x80
dup1
0x40
mstore
jumpi(tag_6, callvalue)
0x1f
bytecodeSize
@ -86,7 +83,6 @@ stop
sub_0: assembly {
/* "viair_subobject_optimization/input.sol":61:668 contract C {... */
mstore(0x40, 0x80)
0x00
dup1
revert
@ -120,9 +116,6 @@ stop
sub_0: assembly {
/* "viair_subobject_optimization/input.sol":669:772 contract D {... */
0x80
dup1
0x40
mstore
jumpi(tag_2, iszero(lt(calldatasize, 0x04)))
tag_3:
pop
@ -283,9 +276,6 @@ sub_0: assembly {
sub_0: assembly {
/* "viair_subobject_optimization/input.sol":61:668 contract C {... */
0x80
dup1
0x40
mstore
jumpi(tag_6, callvalue)
0x1f
bytecodeSize
@ -366,7 +356,6 @@ sub_0: assembly {
sub_0: assembly {
/* "viair_subobject_optimization/input.sol":61:668 contract C {... */
mstore(0x40, 0x80)
0x00
dup1
revert

View File

@ -30,7 +30,6 @@ object "C_3" {
code {
{
/// @src 0:82:95 "contract C {}"
mstore(64, memoryguard(0x80))
revert(0, 0)
}
}
@ -122,7 +121,6 @@ object "D_16" {
code {
{
/// @src 0:82:95 "contract C {}"
mstore(64, memoryguard(0x80))
revert(0, 0)
}
}

View File

@ -0,0 +1,63 @@
import sys
from z3 import Solver, Int, unsat
"""
Tests that the conditions inside RedundantStoreEliminator::knownUnrelated
only return "unrelated" incorrectly if one of the operation reverts
due to large memory access.
"""
n_bits = 256
solver = Solver()
solver.set("timeout", 60000)
def restrict(x):
solver.add(x >= 0)
solver.add(x < 2**n_bits)
def restrictedInt(x):
var = Int(x)
restrict(var)
return var
start1 = restrictedInt('start1')
length1 = restrictedInt('length1')
start2 = restrictedInt('start2')
length2 = restrictedInt('length2')
k = Int('k')
diff = Int('diff')
solver.add(diff == start2 - start1 + k * 2**n_bits)
restrict(diff)
# diff is the result of sub(start2, start1) in EVM
# These are the conditions in the code.
solver.add(diff >= length1)
solver.add(diff <= 2**(n_bits-1))
# We check that the two conditions are conflicting:
# - overlap
# - start1 is small
# Overlap:
# x is a potential point where the memory operations
# overlap.
# Note that we do not use wrapping arithmetic
# here, because it is not done in the EVM either.
# For example calldatacopy(2**256 - 2, 0, 10)
# (copy 10 bytes from calldata position zero to memory
# position 2**256 - 2) would not write to memory position
# zero either.
x = Int('x')
solver.add(start1 <= x)
solver.add(x < start1 + length1)
solver.add(start2 <= x)
solver.add(x < start2 + length2)
# start1 is "small":
solver.add(start1 < 2**(n_bits-1))
if solver.check() != unsat:
print("Expected unsat but got something else")
sys.exit(1)

View File

@ -17,7 +17,7 @@ contract c {
// ----
// setData1(uint256,uint256,uint256): 10, 5, 4 ->
// copyStorageStorage() ->
// gas irOptimized: 111406
// gas irOptimized: 111397
// gas legacy: 109278
// gas legacyOptimized: 109268
// getData2(uint256): 5 -> 10, 4

View File

@ -48,6 +48,6 @@ contract C {
// compileViaYul: also
// ----
// f() -> 0xff
// gas irOptimized: 121145
// gas irOptimized: 121125
// gas legacy: 128005
// gas legacyOptimized: 123446

View File

@ -16,4 +16,4 @@ contract C {
// compileViaYul: also
// ----
// f() -> 0, 0, 0
// gas irOptimized: 91098
// gas irOptimized: 90992

View File

@ -19,5 +19,5 @@ contract c {
// test() ->
// gas irOptimized: 142640
// gas legacy: 164430
// gas legacyOptimized: 158513
// gas legacyOptimized: 157898
// storageEmpty -> 1

View File

@ -26,6 +26,6 @@ contract Main {
// compileViaYul: also
// ----
// f(uint256): 0x34 -> 0x46bddb1178e94d7f2892ff5f366840eb658911794f2c3a44c450aa2c505186c1
// gas irOptimized: 113613
// gas irOptimized: 113604
// gas legacy: 126596
// gas legacyOptimized: 113823

View File

@ -19,7 +19,7 @@ contract Main {
// compileViaYul: also
// ----
// constructor(): "abc", true
// gas irOptimized: 106267
// gas irOptimized: 106221
// gas legacy: 145838
// gas legacyOptimized: 104017
// getFlag() -> true

View File

@ -19,6 +19,6 @@ contract C {
// compileViaYul: also
// ----
// f(), 2000 ether -> true
// gas irOptimized: 123036
// gas irOptimized: 120036
// gas legacy: 123226
// gas legacyOptimized: 123092

View File

@ -11,7 +11,7 @@ contract C {
// compileViaYul: also
// ----
// constructor(): 2, 0 ->
// gas irOptimized: 103363
// gas irOptimized: 103290
// gas legacy: 117158
// i() -> 2
// k() -> 0

View File

@ -23,7 +23,7 @@ contract D is B, C {
// compileViaYul: also
// ----
// constructor(): 2, 0 ->
// gas irOptimized: 160166
// gas irOptimized: 160093
// gas legacy: 170665
// gas legacyOptimized: 145396
// i() -> 2

View File

@ -14,7 +14,7 @@ contract D is C {
// compileViaYul: also
// ----
// constructor(): 2, 0 ->
// gas irOptimized: 123980
// gas irOptimized: 123907
// gas legacy: 139250
// gas legacyOptimized: 119367
// i() -> 2

View File

@ -17,7 +17,7 @@ contract D {
// compileViaYul: also
// ----
// constructor(): 2 ->
// gas irOptimized: 203982
// gas irOptimized: 203909
// gas legacy: 245842
// gas legacyOptimized: 195676
// f() -> 2

View File

@ -18,7 +18,7 @@ contract D {
// compileViaYul: also
// ----
// constructor(): 2 ->
// gas irOptimized: 204145
// gas irOptimized: 204072
// gas legacy: 246202
// gas legacyOptimized: 195914
// f() -> 2

View File

@ -18,7 +18,7 @@ contract C {
// compileViaYul: also
// ----
// constructor(), 20 wei
// gas irOptimized: 219069
// gas irOptimized: 216903
// gas legacy: 294335
// gas legacyOptimized: 174279
// f(uint256): 20 -> 1370859564726510389319704988634906228201275401179

View File

@ -19,7 +19,7 @@ contract Main {
// compileViaYul: also
// ----
// constructor(), 20 wei ->
// gas irOptimized: 102862
// gas irOptimized: 101782
// gas legacy: 116691
// gas legacyOptimized: 100361
// s() -> true

View File

@ -42,7 +42,7 @@ contract Main {
// compileViaYul: also
// ----
// constructor(), 22 wei ->
// gas irOptimized: 282981
// gas irOptimized: 282916
// gas legacy: 402045
// gas legacyOptimized: 266772
// getFlag() -> true

View File

@ -22,6 +22,6 @@ contract Test {
// ----
// library: Lib
// f() -> 1, 0, 0x2a, 0x17, 0, 0x63
// gas irOptimized: 119561
// gas irOptimized: 119501
// gas legacy: 124793
// gas legacyOptimized: 119694

View File

@ -22,6 +22,6 @@ contract A {
// ----
// different_salt() -> true
// same_salt() -> true
// gas irOptimized: 98438914
// gas irOptimized: 98438898
// gas legacy: 98439116
// gas legacyOptimized: 98438970

View File

@ -22,6 +22,6 @@ contract A {
// compileViaYul: also
// ----
// f(), 10 ether -> 3007, 3008, 3009
// gas irOptimized: 272467
// gas irOptimized: 272431
// gas legacy: 422501
// gas legacyOptimized: 287472

View File

@ -14,7 +14,7 @@ contract C {
// compileViaYul: also
// ----
// constructor(), 2 wei: 3 ->
// gas irOptimized: 111699
// gas irOptimized: 111607
// gas legacy: 151416
// gas legacyOptimized: 108388
// state() -> 3

View File

@ -21,6 +21,6 @@ contract c {
// compileViaYul: also
// ----
// test() -> true
// gas irOptimized: 110186
// gas irOptimized: 110177
// gas legacy: 110627
// gas legacyOptimized: 109706

View File

@ -27,4 +27,4 @@ contract C {
// compileViaYul: true
// ----
// f() -> 0
// gas irOptimized: 111896
// gas irOptimized: 112129

View File

@ -32,6 +32,6 @@ contract C {
// compileViaYul: also
// ----
// f() -> 42, 23, 34, 42, 42
// gas irOptimized: 110966
// gas irOptimized: 110845
// gas legacy: 112021
// gas legacyOptimized: 110548

View File

@ -32,7 +32,7 @@ contract test {
// ----
// check() -> false
// set() ->
// gas irOptimized: 134432
// gas irOptimized: 134411
// gas legacy: 135277
// gas legacyOptimized: 134064
// check() -> true

View File

@ -25,7 +25,7 @@ contract C {
// ----
// s() -> 0, 0, 0x00, 0
// f((uint8,uint16,bytes2,uint8)): 1, 0xff, "ab", 15 ->
// gas irOptimized: 44786
// gas irOptimized: 44405
// gas legacy: 47200
// gas legacyOptimized: 44923
// s() -> 1, 0xff, 0x6162000000000000000000000000000000000000000000000000000000000000, 15

View File

@ -25,7 +25,7 @@ contract C {
// ----
// s() -> 0, 0, 0x00, 0
// f((uint8,uint16,bytes2,uint8)): 1, 0xff, "ab", 15 ->
// gas irOptimized: 44536
// gas irOptimized: 44473
// gas legacy: 46213
// gas legacyOptimized: 44671
// s() -> 1, 0xff, 0x6162000000000000000000000000000000000000000000000000000000000000, 15

View File

@ -21,4 +21,4 @@ contract C {
// compileViaYul: also
// ----
// constructor() ->
// gas irOptimized: 104337
// gas irOptimized: 102813

View File

@ -54,6 +54,7 @@
#include <libyul/optimiser/SSATransform.h>
#include <libyul/optimiser/Semantics.h>
#include <libyul/optimiser/UnusedAssignEliminator.h>
#include <libyul/optimiser/UnusedStoreEliminator.h>
#include <libyul/optimiser/StructuralSimplifier.h>
#include <libyul/optimiser/StackCompressor.h>
#include <libyul/optimiser/Suite.h>
@ -237,6 +238,15 @@ YulOptimizerTestCommon::YulOptimizerTestCommon(
ForLoopInitRewriter::run(*m_context, *m_ast);
UnusedAssignEliminator::run(*m_context, *m_ast);
}},
{"unusedStoreEliminator", [&]() {
disambiguate();
ForLoopInitRewriter::run(*m_context, *m_ast);
ExpressionSplitter::run(*m_context, *m_ast);
SSATransform::run(*m_context, *m_ast);
UnusedStoreEliminator::run(*m_context, *m_ast);
SSAReverser::run(*m_context, *m_ast);
ExpressionJoiner::run(*m_context, *m_ast);
}},
{"equalStoreEliminator", [&]() {
disambiguate();
FunctionHoister::run(*m_context, *m_ast);

View File

@ -0,0 +1,40 @@
{
let _1 := 0
let value := calldataload(4)
if iszero(eq(value, and(value, sub(shl(160, 1), 1)))) { revert(_1, _1) }
let length := extcodesize(value)
let _2 := 0xffffffffffffffff
if gt(length, _2) { revert(0, 0) }
let _3 := not(31)
let memPtr := mload(64)
let newFreePtr := add(memPtr, and(add(and(add(length, 31), _3), 63), _3))
if or(gt(newFreePtr, _2), lt(newFreePtr, memPtr)) { revert(0, 0) }
mstore(64, newFreePtr)
mstore(memPtr, length)
// We aim to optimize this out.
extcodecopy(value, add(memPtr, 32), _1, length)
sstore(_1, mload(memPtr))
}
// ====
// EVMVersion: >byzantium
// ----
// step: fullSuite
//
// {
// {
// let value := calldataload(4)
// if iszero(eq(value, and(value, sub(shl(160, 1), 1)))) { revert(0, 0) }
// let length := extcodesize(value)
// let _1 := 0xffffffffffffffff
// if gt(length, _1) { revert(0, 0) }
// let memPtr := mload(64)
// let _2 := not(31)
// let newFreePtr := add(memPtr, and(add(and(add(length, 31), _2), 63), _2))
// if or(gt(newFreePtr, _1), lt(newFreePtr, memPtr)) { revert(0, 0) }
// mstore(64, newFreePtr)
// mstore(memPtr, length)
// extcodecopy(value, add(memPtr, 32), 0, length)
// sstore(0, mload(memPtr))
// }
// }

View File

@ -23,13 +23,7 @@
//
// {
// {
// let p := mload(0x40)
// mstore(0x40, add(p, 0x20))
// mstore(0x40, add(p, 96))
// let p_1 := add(p, 128)
// mstore(p_1, 2)
// mstore(0x40, 0x20)
// sstore(0, p_1)
// sstore(0, add(mload(0x40), 128))
// sstore(1, 0x20)
// }
// }

View File

@ -15,6 +15,5 @@
// case 0 { }
// case 1 { }
// default { invalid() }
// mstore(1, 1)
// }
// }

View File

@ -52,9 +52,9 @@
// pop(keccak256(gcd(_3, _2), or(gt(not(gcd(_3, _2)), _1), _1)))
// mstore(lt(or(gt(_1, or(or(gt(or(or(or(gt(or(gt(_6, _9), _1), _8), _7), _5), _1), _1), _4), _1)), _1), _1), _1)
// sstore(not(gcd(_3, _2)), _1)
// sstore(0, 0)
// sstore(2, _1)
// extcodecopy(_1, msize(), _1, _1)
// sstore(0, 0)
// sstore(3, _1)
// }
// function gcd(_a, _b) -> out

View File

@ -39,7 +39,6 @@
// mstore(4, 0x32)
// revert(_1, 0x24)
// }
// mstore(_1, _1)
// sstore(0x290decd9548b62a8d60345a988386fc84ba6bc95484008f6362f93160ef3e56d, 0x05)
// }
// }

View File

@ -8,7 +8,6 @@
//
// {
// {
// sstore(4, 5)
// sstore(4, 3)
// sstore(8, 3)
// }

View File

@ -20,7 +20,6 @@
// {
// {
// let out1, out2 := foo(sload(32))
// sstore(0, out1)
// sstore(0, out2)
// let out1_1, out2_1 := foo(sload(8))
// }

View File

@ -18,9 +18,9 @@
// {
// {
// f()
// f()
// f()
// sstore(0, 1)
// f()
// f()
// }
// function f()
// {

View File

@ -18,7 +18,6 @@
// {
// let x, y, z := f()
// sstore(0, x)
// sstore(1, y)
// sstore(1, z)
// }
// function f() -> x, y, z

View File

@ -22,8 +22,6 @@
// {
// {
// let out1, out2 := foo(sload(32))
// sstore(0, out1)
// sstore(0, out2)
// sstore(0, 0)
// let out1_1, out2_1 := foo(sload(8))
// }

View File

@ -16,9 +16,9 @@
// {
// {
// f()
// f()
// f()
// sstore(0, 1)
// f()
// f()
// }
// function f()
// {

View File

@ -0,0 +1,24 @@
{
mstore(0, 1)
let x := call(
0,
0,
0,
0,
0,
0,
0x32 // length is only a max length, so there is no guarantee that the mstore above is overwritten.
)
sstore(0, mload(0))
}
// ----
// step: unusedStoreEliminator
//
// {
// {
// mstore(0, 1)
// let x := call(0, 0, 0, 0, 0, 0, 0x32)
// sstore(0, mload(0))
// }
// }

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@ -0,0 +1,59 @@
{
let start := calldataload(0x10)
if calldataload(0) {
// not covered
mstore(add(start, 2), 7)
calldatacopy(start, 0, 0x20)
}
if calldataload(1) {
// covered
mstore(add(start, 2), 9)
calldatacopy(add(start, 1), 0, 0x21)
}
if calldataload(2) {
// covered
mstore8(add(start, 2), 7)
calldatacopy(start, 0, 3)
}
if calldataload(3) {
// not covered
mstore8(add(start, 3), 7)
calldatacopy(start, 0, 3)
}
sstore(0, keccak256(start, 0x40))
}
// ----
// step: unusedStoreEliminator
//
// {
// {
// let start := calldataload(0x10)
// if calldataload(0)
// {
// let _4 := 7
// mstore(add(start, 2), _4)
// calldatacopy(start, 0, 0x20)
// }
// if calldataload(1)
// {
// let _11 := 9
// mstore(add(start, 2), _11)
// let _14 := 0x21
// let _15 := 0
// calldatacopy(add(start, 1), _15, _14)
// }
// if calldataload(2)
// {
// let _20 := 7
// mstore8(add(start, 2), _20)
// calldatacopy(start, 0, 3)
// }
// if calldataload(3)
// {
// let _27 := 7
// mstore8(add(start, 3), _27)
// calldatacopy(start, 0, 3)
// }
// sstore(0, keccak256(start, 0x40))
// }
// }

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@ -0,0 +1,53 @@
{
if calldataload(0) {
// not covered
mstore(2, 7)
calldatacopy(0, 0, 0x20)
}
if calldataload(1) {
// covered
mstore(2, 9)
calldatacopy(1, 0, 0x21)
}
if calldataload(2) {
// covered
mstore8(2, 7)
calldatacopy(0, 0, 3)
}
if calldataload(3) {
// not covered
mstore8(3, 7)
calldatacopy(0, 0, 3)
}
sstore(0, keccak256(0, 0x40))
}
// ----
// step: unusedStoreEliminator
//
// {
// {
// if calldataload(0)
// {
// mstore(2, 7)
// calldatacopy(0, 0, 0x20)
// }
// if calldataload(1)
// {
// let _10 := 9
// let _11 := 2
// calldatacopy(1, 0, 0x21)
// }
// if calldataload(2)
// {
// let _17 := 7
// let _18 := 2
// calldatacopy(0, 0, 3)
// }
// if calldataload(3)
// {
// mstore8(3, 7)
// calldatacopy(0, 0, 3)
// }
// sstore(0, keccak256(0, 0x40))
// }
// }

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@ -0,0 +1,17 @@
{
let x := 5
sstore(x, 10)
pop(create(0, 0, 0))
sstore(x, 20)
}
// ----
// step: unusedStoreEliminator
//
// {
// {
// let x := 5
// sstore(x, 10)
// pop(create(0, 0, 0))
// sstore(x, 20)
// }
// }

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@ -0,0 +1,22 @@
{
let x := 5
function f() {
pop(create(0, 0, 0))
}
sstore(x, 10)
f()
sstore(x, 20)
}
// ----
// step: unusedStoreEliminator
//
// {
// {
// let x := 5
// sstore(x, 10)
// f()
// sstore(x, 20)
// }
// function f()
// { pop(create(0, 0, 0)) }
// }

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@ -0,0 +1,20 @@
{
function f() {
let x := calldataload(2)
mstore(x, 2)
// This cannot be removed because we do not know what happens after the function.
mstore(x, 3)
}
}
// ----
// step: unusedStoreEliminator
//
// {
// { }
// function f()
// {
// let x := calldataload(2)
// let _2 := 2
// mstore(x, 3)
// }
// }

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@ -0,0 +1,55 @@
{
function justStop() { return(0, 0) }
function justRevert() { revert(0, 0) }
let x := 0
let y := 1
let a := 0x80
let b := 7
let c := 9
switch calldataload(0)
case 0
{
sstore(x, y)
mstore(a, b)
justStop()
sstore(x, y)
mstore(a, b)
}
case 1
{
sstore(x, y)
mstore(a, b)
justRevert()
sstore(x, y)
mstore(a, b)
}
}
// ----
// step: unusedStoreEliminator
//
// {
// {
// let x := 0
// let y := 1
// let a := 0x80
// let b := 7
// let c := 9
// switch calldataload(0)
// case 0 {
// sstore(x, y)
// mstore(a, b)
// justStop()
// sstore(x, y)
// }
// case 1 {
// mstore(a, b)
// justRevert()
// sstore(x, y)
// }
// }
// function justStop()
// { return(0, 0) }
// function justRevert()
// { revert(0, 0) }
// }

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@ -0,0 +1,28 @@
{
let x := 0
let y := 1
sstore(x, y)
f()
sstore(x, y)
function f() {
// prevent inlining
f()
return(0, 0)
}
}
// ----
// step: unusedStoreEliminator
//
// {
// {
// let x := 0
// let y := 1
// f()
// sstore(x, y)
// }
// function f()
// {
// f()
// return(0, 0)
// }
// }

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@ -0,0 +1,20 @@
{
let c := calldataload(0)
// This store will be overwritten in all branches and thus can be removed.
sstore(c, 1)
if c {
sstore(c, 2)
}
sstore(c, 3)
}
// ----
// step: unusedStoreEliminator
//
// {
// {
// let c := calldataload(0)
// let _2 := 1
// if c { let _3 := 2 }
// sstore(c, 3)
// }
// }

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@ -0,0 +1,23 @@
{
function f() {
mstore(0, 5)
if calldataload(0) { leave }
mstore(0x20, 5)
revert(0, 0)
}
f()
}
// ----
// step: unusedStoreEliminator
//
// {
// { f() }
// function f()
// {
// mstore(0, 5)
// if calldataload(0) { leave }
// let _5 := 5
// let _6 := 0x20
// revert(0, 0)
// }
// }

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@ -0,0 +1,24 @@
{
mstore(0x40, memoryguard(100))
let free_mem_ptr := mload(0x40)
// redundant
mstore(free_mem_ptr, 100)
// redundant
mstore8(add(free_mem_ptr, 31), 200)
mstore(free_mem_ptr, 300)
return(free_mem_ptr, add(free_mem_ptr, 100))
}
// ----
// step: unusedStoreEliminator
//
// {
// {
// mstore(0x40, memoryguard(100))
// let free_mem_ptr := mload(0x40)
// let _4 := 100
// let _5 := 200
// mstore8(add(free_mem_ptr, 31), _5)
// mstore(free_mem_ptr, 300)
// return(free_mem_ptr, add(free_mem_ptr, 100))
// }
// }

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@ -0,0 +1,20 @@
{
let zero := 0
mstore(zero, 5)
let x := mload(zero)
mstore(zero, 8)
let y := mload(zero)
sstore(zero, y)
}
// ----
// step: unusedStoreEliminator
//
// {
// {
// let zero := 0
// mstore(zero, 5)
// let x := mload(zero)
// mstore(zero, 8)
// sstore(zero, mload(zero))
// }
// }

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@ -0,0 +1,27 @@
{
function f() -> r {
r := mload(0x20)
}
let x := 5
sstore(x, 10) // should be removed
mstore(0, 42) // could be removed, but will probably stay?
pop(f())
sstore(x, 10)
}
// ----
// step: unusedStoreEliminator
//
// {
// {
// let x := 5
// let _2 := 10
// mstore(0, 42)
// pop(f())
// sstore(x, 10)
// }
// function f() -> r
// {
// r := mload(0x20)
// let r_7 := r
// }
// }

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@ -0,0 +1,18 @@
{
let x := 0
calldatacopy(0, 0, 115792089237316195423570985008687907853269984665640564039457584007913129639935)
mstore(x, 20)
return(0, 32)
}
// ----
// step: unusedStoreEliminator
//
// {
// {
// let x := 0
// calldatacopy(0, 0, 115792089237316195423570985008687907853269984665640564039457584007913129639935)
// mstore(x, 20)
// return(0, 32)
// }
// }

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@ -0,0 +1,21 @@
{
let _1 := 0
if callvalue() { revert(_1, _1) }
mstore(_1, shl(224, 0x4e487b71))
mstore(4, 0x32)
revert(_1, 0x24)
}
// ====
// EVMVersion: >=constantinople
// ----
// step: unusedStoreEliminator
//
// {
// {
// let _1 := 0
// if callvalue() { revert(_1, _1) }
// mstore(_1, shl(224, 0x4e487b71))
// mstore(4, 0x32)
// revert(_1, 0x24)
// }
// }

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@ -0,0 +1,27 @@
{
let _1 := 0
let _2 := callvalue()
let _3 := 0x4e487b71
let _4 := 224
let _5 := 7
mstore(_1, _5)
let _6 := 0x32
let _7 := 4
mstore(_7, _6)
let _8 := 0x24
revert(_1, _8)
}
// ----
// step: unusedStoreEliminator
//
// {
// {
// let _1 := 0
// let _2 := callvalue()
// let _3 := 0x4e487b71
// let _4 := 224
// mstore(_1, 7)
// mstore(4, 0x32)
// revert(_1, 0x24)
// }
// }

View File

@ -0,0 +1,21 @@
{
let c := calldataload(0)
mstore(c, 4)
if c {
sstore(c, 2)
}
let d := 0
revert(d, d)
}
// ----
// step: unusedStoreEliminator
//
// {
// {
// let c := calldataload(0)
// let _2 := 4
// if c { let _3 := 2 }
// let d := 0
// revert(d, d)
// }
// }

View File

@ -0,0 +1,17 @@
{
let zero := 0
mstore(zero, 0x1234)
mstore(4, 0x456)
revert(zero, 5)
}
// ----
// step: unusedStoreEliminator
//
// {
// {
// let zero := 0
// mstore(zero, 0x1234)
// mstore(4, 0x456)
// revert(zero, 5)
// }
// }

View File

@ -0,0 +1,33 @@
{
let a
switch calldataload(0)
case 0 { a := calldataload(9) }
case 1 { a := calldataload(10) }
calldatacopy(0x20, 0, a)
let x := mload(0)
sstore(0, x)
}
// ----
// step: unusedStoreEliminator
//
// {
// {
// let a_9
// let a := a_9
// switch calldataload(0)
// case 0 {
// a := calldataload(9)
// let a_10 := a
// }
// case 1 {
// let a_12 := a
// a := calldataload(10)
// let a_11 := a
// }
// let a_13 := a
// let _5 := 0
// let _6 := 0x20
// sstore(0, mload(0))
// }
// }

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@ -0,0 +1,23 @@
{
let c := calldataload(0)
mstore(c, 4)
mstore(add(c, 0x20), 8)
sstore(0, mload(c))
mstore(c, 9)
mstore(add(c, 0x20), 20)
}
// ----
// step: unusedStoreEliminator
//
// {
// {
// let c := calldataload(0)
// mstore(c, 4)
// let _3 := 8
// let _5 := add(c, 0x20)
// sstore(0, mload(c))
// let _8 := 9
// let _9 := 20
// let _11 := add(c, 0x20)
// }
// }

View File

@ -0,0 +1,27 @@
{
sstore(0, 1)
mstore(0, 2)
f()
function f() {
g()
}
function g() {
f()
}
}
// ----
// step: unusedStoreEliminator
//
// {
// {
// let _1 := 1
// let _2 := 0
// let _3 := 2
// let _4 := 0
// f()
// }
// function f()
// { g() }
// function g()
// { f() }
// }

View File

@ -138,7 +138,7 @@ BOOST_AUTO_TEST_CASE(output_operator_should_create_concise_and_unambiguous_strin
BOOST_TEST(chromosome.length() == allSteps.size());
BOOST_TEST(chromosome.optimisationSteps() == allSteps);
BOOST_TEST(toString(chromosome) == "flcCUnDEvejsxIOoighFTLMRmVatrpud");
BOOST_TEST(toString(chromosome) == "flcCUnDEvejsxIOoighFTLMRmVatrpuSd");
}
BOOST_AUTO_TEST_CASE(optimisationSteps_should_translate_chromosomes_genes_to_optimisation_step_names)