Merge pull request #3693 from ethereum/optimizeMLOAD

Optimize across MLOAD if MSIZE is not used.
This commit is contained in:
Alex Beregszaszi
2018-04-03 15:58:11 +01:00
committed by GitHub
12 changed files with 148 additions and 42 deletions
+13
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@@ -229,6 +229,9 @@ public:
/// i.e. it behaves differently in lvalue context and in value context.
virtual bool isValueType() const { return false; }
virtual unsigned sizeOnStack() const { return 1; }
/// If it is possible to initialize such a value in memory by just writing zeros
/// of the size memoryHeadSize().
virtual bool hasSimpleZeroValueInMemory() const { return true; }
/// @returns the mobile (in contrast to static) type corresponding to the given type.
/// This returns the corresponding IntegerType or FixedPointType for RationalNumberType
/// and the pointer type for storage reference types.
@@ -568,6 +571,7 @@ public:
virtual TypePointer mobileType() const override { return copyForLocation(m_location, true); }
virtual bool dataStoredIn(DataLocation _location) const override { return m_location == _location; }
virtual bool hasSimpleZeroValueInMemory() const override { return false; }
/// Storage references can be pointers or bound references. In general, local variables are of
/// pointer type, state variables are bound references. Assignments to pointers or deleting
@@ -855,6 +859,7 @@ public:
virtual u256 storageSize() const override;
virtual bool canLiveOutsideStorage() const override { return false; }
virtual unsigned sizeOnStack() const override;
virtual bool hasSimpleZeroValueInMemory() const override { return false; }
virtual TypePointer mobileType() const override;
/// Converts components to their temporary types and performs some wildcard matching.
virtual TypePointer closestTemporaryType(TypePointer const& _targetType) const override;
@@ -999,6 +1004,7 @@ public:
virtual bool isValueType() const override { return true; }
virtual bool canLiveOutsideStorage() const override { return m_kind == Kind::Internal || m_kind == Kind::External; }
virtual unsigned sizeOnStack() const override;
virtual bool hasSimpleZeroValueInMemory() const override { return false; }
virtual MemberList::MemberMap nativeMembers(ContractDefinition const* _currentScope) const override;
virtual TypePointer encodingType() const override;
virtual TypePointer interfaceType(bool _inLibrary) const override;
@@ -1104,6 +1110,8 @@ public:
return _inLibrary ? shared_from_this() : TypePointer();
}
virtual bool dataStoredIn(DataLocation _location) const override { return _location == DataLocation::Storage; }
/// Cannot be stored in memory, but just in case.
virtual bool hasSimpleZeroValueInMemory() const override { solAssert(false, ""); }
TypePointer const& keyType() const { return m_keyType; }
TypePointer const& valueType() const { return m_valueType; }
@@ -1132,6 +1140,7 @@ public:
virtual u256 storageSize() const override;
virtual bool canLiveOutsideStorage() const override { return false; }
virtual unsigned sizeOnStack() const override;
virtual bool hasSimpleZeroValueInMemory() const override { solAssert(false, ""); }
virtual std::string toString(bool _short) const override { return "type(" + m_actualType->toString(_short) + ")"; }
virtual MemberList::MemberMap nativeMembers(ContractDefinition const* _currentScope) const override;
@@ -1154,6 +1163,7 @@ public:
virtual u256 storageSize() const override;
virtual bool canLiveOutsideStorage() const override { return false; }
virtual unsigned sizeOnStack() const override { return 0; }
virtual bool hasSimpleZeroValueInMemory() const override { solAssert(false, ""); }
virtual std::string richIdentifier() const override;
virtual bool operator==(Type const& _other) const override;
virtual std::string toString(bool _short) const override;
@@ -1179,6 +1189,7 @@ public:
virtual bool operator==(Type const& _other) const override;
virtual bool canBeStored() const override { return false; }
virtual bool canLiveOutsideStorage() const override { return true; }
virtual bool hasSimpleZeroValueInMemory() const override { solAssert(false, ""); }
virtual unsigned sizeOnStack() const override { return 0; }
virtual MemberList::MemberMap nativeMembers(ContractDefinition const*) const override;
@@ -1209,6 +1220,7 @@ public:
virtual bool operator==(Type const& _other) const override;
virtual bool canBeStored() const override { return false; }
virtual bool canLiveOutsideStorage() const override { return true; }
virtual bool hasSimpleZeroValueInMemory() const override { solAssert(false, ""); }
virtual unsigned sizeOnStack() const override { return 0; }
virtual MemberList::MemberMap nativeMembers(ContractDefinition const*) const override;
@@ -1238,6 +1250,7 @@ public:
virtual bool canLiveOutsideStorage() const override { return false; }
virtual bool isValueType() const override { return true; }
virtual unsigned sizeOnStack() const override { return 1; }
virtual bool hasSimpleZeroValueInMemory() const override { solAssert(false, ""); }
virtual std::string toString(bool) const override { return "inaccessible dynamic type"; }
virtual TypePointer decodingType() const override { return std::make_shared<IntegerType>(256); }
};
+28 -8
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@@ -495,14 +495,34 @@ void CompilerUtils::abiDecodeV2(TypePointers const& _parameterTypes, bool _fromM
void CompilerUtils::zeroInitialiseMemoryArray(ArrayType const& _type)
{
auto repeat = m_context.newTag();
m_context << repeat;
pushZeroValue(*_type.baseType());
storeInMemoryDynamic(*_type.baseType());
m_context << Instruction::SWAP1 << u256(1) << Instruction::SWAP1;
m_context << Instruction::SUB << Instruction::SWAP1;
m_context << Instruction::DUP2;
m_context.appendConditionalJumpTo(repeat);
if (_type.baseType()->hasSimpleZeroValueInMemory())
{
solAssert(_type.baseType()->isValueType(), "");
Whiskers templ(R"({
let size := mul(length, <element_size>)
// cheap way of zero-initializing a memory range
codecopy(memptr, codesize(), size)
memptr := add(memptr, size)
})");
templ("element_size", to_string(_type.baseType()->memoryHeadSize()));
m_context.appendInlineAssembly(templ.render(), {"length", "memptr"});
}
else
{
// TODO: Potential optimization:
// When we create a new multi-dimensional dynamic array, each element
// is initialized to an empty array. It actually does not hurt
// to re-use exactly the same empty array for all elements. Currently,
// a new one is created each time.
auto repeat = m_context.newTag();
m_context << repeat;
pushZeroValue(*_type.baseType());
storeInMemoryDynamic(*_type.baseType());
m_context << Instruction::SWAP1 << u256(1) << Instruction::SWAP1;
m_context << Instruction::SUB << Instruction::SWAP1;
m_context << Instruction::DUP2;
m_context.appendConditionalJumpTo(repeat);
}
m_context << Instruction::SWAP1 << Instruction::POP;
}
+4 -17
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@@ -850,8 +850,6 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall)
}
case FunctionType::Kind::ObjectCreation:
{
// Will allocate at the end of memory (MSIZE) and not write at all unless the base
// type is dynamically sized.
ArrayType const& arrayType = dynamic_cast<ArrayType const&>(*_functionCall.annotation().type);
_functionCall.expression().accept(*this);
solAssert(arguments.size() == 1, "");
@@ -861,15 +859,7 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall)
utils().convertType(*arguments[0]->annotation().type, IntegerType(256));
// Stack: requested_length
// Allocate at max(MSIZE, freeMemoryPointer)
utils().fetchFreeMemoryPointer();
m_context << Instruction::DUP1 << Instruction::MSIZE;
m_context << Instruction::LT;
auto initialise = m_context.appendConditionalJump();
// Free memory pointer does not point to empty memory, use MSIZE.
m_context << Instruction::POP;
m_context << Instruction::MSIZE;
m_context << initialise;
// Stack: requested_length memptr
m_context << Instruction::SWAP1;
@@ -894,13 +884,10 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall)
// Check if length is zero
m_context << Instruction::DUP1 << Instruction::ISZERO;
auto skipInit = m_context.appendConditionalJump();
// We only have to initialise if the base type is a not a value type.
if (dynamic_cast<ReferenceType const*>(arrayType.baseType().get()))
{
m_context << Instruction::DUP2 << u256(32) << Instruction::ADD;
utils().zeroInitialiseMemoryArray(arrayType);
}
// Always initialize because the free memory pointer might point at
// a dirty memory area.
m_context << Instruction::DUP2 << u256(32) << Instruction::ADD;
utils().zeroInitialiseMemoryArray(arrayType);
m_context << skipInit;
m_context << Instruction::POP;
break;