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[Codegen] Do not perform cleanup on unsigned integers when loading from calldata. #5368

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Merged
merged 1 commit into from
Nov 14, 2018
Merged

[Codegen] Do not perform cleanup on unsigned integers when loading from calldata. #5368

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1 change: 1 addition & 0 deletions Changelog.md
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Original file line number Diff line number Diff line change
Expand Up @@ -5,6 +5,7 @@ Language Features:

Compiler Features:
* Build System: LLL is not built anymore by default. Must configure it with CMake as `-DLLL=ON`.
* Code generator: Do not perform redundant double cleanup on unsigned integers when loading from calldata.


Bugfixes:
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9 changes: 8 additions & 1 deletion libsolidity/codegen/CompilerUtils.cpp
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Expand Up @@ -1236,6 +1236,7 @@ unsigned CompilerUtils::loadFromMemoryHelper(Type const& _type, bool _fromCallda
}
solAssert(numBytes <= 32, "Static memory load of more than 32 bytes requested.");
m_context << (_fromCalldata ? Instruction::CALLDATALOAD : Instruction::MLOAD);
bool cleanupNeeded = true;
if (isExternalFunctionType)
splitExternalFunctionType(true);
else if (numBytes != 32)
Expand All @@ -1245,10 +1246,16 @@ unsigned CompilerUtils::loadFromMemoryHelper(Type const& _type, bool _fromCallda
int shiftFactor = (32 - numBytes) * 8;
rightShiftNumberOnStack(shiftFactor);
if (leftAligned)
{
leftShiftNumberOnStack(shiftFactor);
cleanupNeeded = false;
}
else if (IntegerType const* intType = dynamic_cast<IntegerType const*>(&_type))
if (!intType->isSigned())
cleanupNeeded = false;
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Shouldn't this only be a special case for uint256?

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No, because we shift right by the appropriate amount. The use-case in mind actually uses uint32 (the 4 byte function selector).

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Right, this is in the non-32byte branch.

Ah, forgot it is BE and not LE. The code looks good.

}
if (_fromCalldata)
convertType(_type, _type, true, false, true);
convertType(_type, _type, cleanupNeeded, false, true);

return numBytes;
}
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2 changes: 1 addition & 1 deletion test/libsolidity/Assembly.cpp
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Expand Up @@ -160,7 +160,7 @@ BOOST_AUTO_TEST_CASE(location_test)
AssemblyItems items = compileContract(sourceCode);
bool hasShifts = dev::test::Options::get().evmVersion().hasBitwiseShifting();
vector<SourceLocation> locations =
vector<SourceLocation>(hasShifts ? 23 : 24, SourceLocation(2, 82, make_shared<string>(""))) +
vector<SourceLocation>(hasShifts ? 21 : 22, SourceLocation(2, 82, make_shared<string>(""))) +
vector<SourceLocation>(2, SourceLocation(20, 79, make_shared<string>(""))) +
vector<SourceLocation>(1, SourceLocation(8, 17, make_shared<string>("--CODEGEN--"))) +
vector<SourceLocation>(3, SourceLocation(5, 7, make_shared<string>("--CODEGEN--"))) +
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