From 22bfd3da41ae9efa6e68e884f722502ab3adcf50 Mon Sep 17 00:00:00 2001 From: Alex Beregszaszi Date: Thu, 29 Mar 2018 09:56:51 +0100 Subject: Use native shift instructions on Constantinople --- libsolidity/codegen/CompilerUtils.cpp | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'libsolidity/codegen/CompilerUtils.cpp') diff --git a/libsolidity/codegen/CompilerUtils.cpp b/libsolidity/codegen/CompilerUtils.cpp index 4af7d905..46e81d49 100644 --- a/libsolidity/codegen/CompilerUtils.cpp +++ b/libsolidity/codegen/CompilerUtils.cpp @@ -1265,13 +1265,19 @@ void CompilerUtils::cleanHigherOrderBits(IntegerType const& _typeOnStack) void CompilerUtils::leftShiftNumberOnStack(unsigned _bits) { solAssert(_bits < 256, ""); - m_context << (u256(1) << _bits) << Instruction::MUL; + if (m_context.evmVersion().hasBitwiseShifting()) + m_context << _bits << Instruction::SHL; + else + m_context << (u256(1) << _bits) << Instruction::MUL; } void CompilerUtils::rightShiftNumberOnStack(unsigned _bits, bool _isSigned) { solAssert(_bits < 256, ""); - m_context << (u256(1) << _bits) << Instruction::SWAP1 << (_isSigned ? Instruction::SDIV : Instruction::DIV); + if (m_context.evmVersion().hasBitwiseShifting()) + m_context << _bits << (_isSigned ? Instruction::SAR : Instruction::SHR); + else + m_context << (u256(1) << _bits) << Instruction::SWAP1 << (_isSigned ? Instruction::SDIV : Instruction::DIV); } unsigned CompilerUtils::prepareMemoryStore(Type const& _type, bool _padToWords) -- cgit v1.2.3 From 52c94418795f829c4a225fdf4742eec7a1961232 Mon Sep 17 00:00:00 2001 From: Alex Beregszaszi Date: Fri, 6 Apr 2018 14:54:21 +0200 Subject: Do not use SAR instead of SDIV in shifts because it rounds differently --- libsolidity/codegen/CompilerUtils.cpp | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'libsolidity/codegen/CompilerUtils.cpp') diff --git a/libsolidity/codegen/CompilerUtils.cpp b/libsolidity/codegen/CompilerUtils.cpp index 46e81d49..45ad1f47 100644 --- a/libsolidity/codegen/CompilerUtils.cpp +++ b/libsolidity/codegen/CompilerUtils.cpp @@ -1274,8 +1274,9 @@ void CompilerUtils::leftShiftNumberOnStack(unsigned _bits) void CompilerUtils::rightShiftNumberOnStack(unsigned _bits, bool _isSigned) { solAssert(_bits < 256, ""); - if (m_context.evmVersion().hasBitwiseShifting()) - m_context << _bits << (_isSigned ? Instruction::SAR : Instruction::SHR); + // NOTE: SAR rounds differently than SDIV + if (m_context.evmVersion().hasBitwiseShifting() && !_isSigned) + m_context << _bits << Instruction::SHR; else m_context << (u256(1) << _bits) << Instruction::SWAP1 << (_isSigned ? Instruction::SDIV : Instruction::DIV); } -- cgit v1.2.3 From 2968639406888d97bfae70e4adf41674ac60fd83 Mon Sep 17 00:00:00 2001 From: chriseth Date: Fri, 6 Apr 2018 16:25:13 +0200 Subject: Removed signed shift right from the utilities. --- libsolidity/codegen/CompilerUtils.cpp | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'libsolidity/codegen/CompilerUtils.cpp') diff --git a/libsolidity/codegen/CompilerUtils.cpp b/libsolidity/codegen/CompilerUtils.cpp index 45ad1f47..48b77eb3 100644 --- a/libsolidity/codegen/CompilerUtils.cpp +++ b/libsolidity/codegen/CompilerUtils.cpp @@ -599,15 +599,15 @@ void CompilerUtils::splitExternalFunctionType(bool _leftAligned) if (_leftAligned) { m_context << Instruction::DUP1; - rightShiftNumberOnStack(64 + 32, false); + rightShiftNumberOnStack(64 + 32); //
m_context << Instruction::SWAP1; - rightShiftNumberOnStack(64, false); + rightShiftNumberOnStack(64); } else { m_context << Instruction::DUP1; - rightShiftNumberOnStack(32, false); + rightShiftNumberOnStack(32); m_context << ((u256(1) << 160) - 1) << Instruction::AND << Instruction::SWAP1; } m_context << u256(0xffffffffUL) << Instruction::AND; @@ -675,7 +675,7 @@ void CompilerUtils::convertType( // conversion from bytes to integer. no need to clean the high bit // only to shift right because of opposite alignment IntegerType const& targetIntegerType = dynamic_cast(_targetType); - rightShiftNumberOnStack(256 - typeOnStack.numBytes() * 8, false); + rightShiftNumberOnStack(256 - typeOnStack.numBytes() * 8); if (targetIntegerType.numBits() < typeOnStack.numBytes() * 8) convertType(IntegerType(typeOnStack.numBytes() * 8), _targetType, _cleanupNeeded); } @@ -1242,7 +1242,7 @@ unsigned CompilerUtils::loadFromMemoryHelper(Type const& _type, bool _fromCallda bool leftAligned = _type.category() == Type::Category::FixedBytes; // add leading or trailing zeros by dividing/multiplying depending on alignment int shiftFactor = (32 - numBytes) * 8; - rightShiftNumberOnStack(shiftFactor, false); + rightShiftNumberOnStack(shiftFactor); if (leftAligned) leftShiftNumberOnStack(shiftFactor); } @@ -1271,14 +1271,14 @@ void CompilerUtils::leftShiftNumberOnStack(unsigned _bits) m_context << (u256(1) << _bits) << Instruction::MUL; } -void CompilerUtils::rightShiftNumberOnStack(unsigned _bits, bool _isSigned) +void CompilerUtils::rightShiftNumberOnStack(unsigned _bits) { solAssert(_bits < 256, ""); - // NOTE: SAR rounds differently than SDIV - if (m_context.evmVersion().hasBitwiseShifting() && !_isSigned) + // NOTE: If we add signed right shift, SAR rounds differently than SDIV + if (m_context.evmVersion().hasBitwiseShifting()) m_context << _bits << Instruction::SHR; else - m_context << (u256(1) << _bits) << Instruction::SWAP1 << (_isSigned ? Instruction::SDIV : Instruction::DIV); + m_context << (u256(1) << _bits) << Instruction::SWAP1 << Instruction::DIV; } unsigned CompilerUtils::prepareMemoryStore(Type const& _type, bool _padToWords) -- cgit v1.2.3