From c3608eaf90b49771b2785d86bb0c73dca6e61046 Mon Sep 17 00:00:00 2001 From: Alex Beregszaszi Date: Thu, 5 Apr 2018 16:56:02 +0200 Subject: Use native shift instructions in ABIFunctions on Constantinople --- libsolidity/codegen/ABIFunctions.cpp | 87 +++++++++++++++++++++++++----------- 1 file changed, 62 insertions(+), 25 deletions(-) (limited to 'libsolidity/codegen/ABIFunctions.cpp') diff --git a/libsolidity/codegen/ABIFunctions.cpp b/libsolidity/codegen/ABIFunctions.cpp index 8e890854..f6aa714d 100644 --- a/libsolidity/codegen/ABIFunctions.cpp +++ b/libsolidity/codegen/ABIFunctions.cpp @@ -1401,37 +1401,74 @@ string ABIFunctions::copyToMemoryFunction(bool _fromCalldata) string ABIFunctions::shiftLeftFunction(size_t _numBits) { + solAssert(_numBits < 256, ""); + string functionName = "shift_left_" + to_string(_numBits); - return createFunction(functionName, [&]() { - solAssert(_numBits < 256, ""); - return - Whiskers(R"( - function (value) -> newValue { - newValue := mul(value, ) - } - )") - ("functionName", functionName) - ("multiplier", toCompactHexWithPrefix(u256(1) << _numBits)) - .render(); - }); + if (m_evmVersion.hasBitwiseShifting()) + { + return createFunction(functionName, [&]() { + return + Whiskers(R"( + function (value) -> newValue { + newValue := shl(, value) + } + )") + ("functionName", functionName) + ("numBits", to_string(_numBits)) + .render(); + }); + } + else + { + return createFunction(functionName, [&]() { + return + Whiskers(R"( + function (value) -> newValue { + newValue := mul(value, ) + } + )") + ("functionName", functionName) + ("multiplier", toCompactHexWithPrefix(u256(1) << _numBits)) + .render(); + }); + } } string ABIFunctions::shiftRightFunction(size_t _numBits, bool _signed) { + solAssert(_numBits < 256, ""); + string functionName = "shift_right_" + to_string(_numBits) + (_signed ? "_signed" : "_unsigned"); - return createFunction(functionName, [&]() { - solAssert(_numBits < 256, ""); - return - Whiskers(R"( - function (value) -> newValue { - newValue :=
(value, ) - } - )") - ("functionName", functionName) - ("div", _signed ? "sdiv" : "div") - ("multiplier", toCompactHexWithPrefix(u256(1) << _numBits)) - .render(); - }); + if (m_evmVersion.hasBitwiseShifting()) + { + return createFunction(functionName, [&]() { + return + Whiskers(R"( + function (value) -> newValue { + newValue := (, value) + } + )") + ("functionName", functionName) + ("shiftOp", _signed ? "sar" : "shr") + ("numBits", to_string(_numBits)) + .render(); + }); + } + else + { + return createFunction(functionName, [&]() { + return + Whiskers(R"( + function (value) -> newValue { + newValue :=
(value, ) + } + )") + ("functionName", functionName) + ("div", _signed ? "sdiv" : "div") + ("multiplier", toCompactHexWithPrefix(u256(1) << _numBits)) + .render(); + }); + } } string ABIFunctions::roundUpFunction() -- 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/ABIFunctions.cpp | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'libsolidity/codegen/ABIFunctions.cpp') diff --git a/libsolidity/codegen/ABIFunctions.cpp b/libsolidity/codegen/ABIFunctions.cpp index f6aa714d..6c4ddc02 100644 --- a/libsolidity/codegen/ABIFunctions.cpp +++ b/libsolidity/codegen/ABIFunctions.cpp @@ -1439,17 +1439,18 @@ string ABIFunctions::shiftRightFunction(size_t _numBits, bool _signed) solAssert(_numBits < 256, ""); string functionName = "shift_right_" + to_string(_numBits) + (_signed ? "_signed" : "_unsigned"); - if (m_evmVersion.hasBitwiseShifting()) + + // NOTE: SAR rounds differently than SDIV + if (m_evmVersion.hasBitwiseShifting() && !_signed) { return createFunction(functionName, [&]() { return Whiskers(R"( function (value) -> newValue { - newValue := (, value) + newValue := shr(, value) } )") ("functionName", functionName) - ("shiftOp", _signed ? "sar" : "shr") ("numBits", to_string(_numBits)) .render(); }); -- 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/ABIFunctions.cpp | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) (limited to 'libsolidity/codegen/ABIFunctions.cpp') diff --git a/libsolidity/codegen/ABIFunctions.cpp b/libsolidity/codegen/ABIFunctions.cpp index 6c4ddc02..3e3aa0ae 100644 --- a/libsolidity/codegen/ABIFunctions.cpp +++ b/libsolidity/codegen/ABIFunctions.cpp @@ -371,7 +371,7 @@ string ABIFunctions::conversionFunction(Type const& _from, Type const& _to) if (toCategory == Type::Category::Integer) body = Whiskers("converted := ((value))") - ("shift", shiftRightFunction(256 - from.numBytes() * 8, false)) + ("shift", shiftRightFunction(256 - from.numBytes() * 8)) ("convert", conversionFunction(IntegerType(from.numBytes() * 8), _to)) .render(); else @@ -458,8 +458,8 @@ string ABIFunctions::splitExternalFunctionIdFunction() } )") ("functionName", functionName) - ("shr32", shiftRightFunction(32, false)) - ("shr64", shiftRightFunction(64, false)) + ("shr32", shiftRightFunction(32)) + ("shr64", shiftRightFunction(64)) .render(); }); } @@ -831,7 +831,7 @@ string ABIFunctions::abiEncodingFunctionCompactStorageArray( templ("encodeToMemoryFun", encodeToMemoryFun); std::vector> items(itemsPerSlot); for (size_t i = 0; i < itemsPerSlot; ++i) - items[i]["shiftRightFun"] = shiftRightFunction(i * storageBytes * 8, false); + items[i]["shiftRightFun"] = shiftRightFunction(i * storageBytes * 8); templ("items", items); return templ.render(); } @@ -927,7 +927,7 @@ string ABIFunctions::abiEncodingFunctionStruct( } else memberTempl("preprocess", ""); - memberTempl("retrieveValue", shiftRightFunction(intraSlotOffset * 8, false) + "(slotValue)"); + memberTempl("retrieveValue", shiftRightFunction(intraSlotOffset * 8) + "(slotValue)"); } else { @@ -1434,14 +1434,15 @@ string ABIFunctions::shiftLeftFunction(size_t _numBits) } } -string ABIFunctions::shiftRightFunction(size_t _numBits, bool _signed) +string ABIFunctions::shiftRightFunction(size_t _numBits) { solAssert(_numBits < 256, ""); - string functionName = "shift_right_" + to_string(_numBits) + (_signed ? "_signed" : "_unsigned"); + // Note that if this is extended with signed shifts, + // the opcodes SAR and SDIV behave differently with regards to rounding! - // NOTE: SAR rounds differently than SDIV - if (m_evmVersion.hasBitwiseShifting() && !_signed) + string functionName = "shift_right_" + to_string(_numBits) + "_unsigned"; + if (m_evmVersion.hasBitwiseShifting()) { return createFunction(functionName, [&]() { return @@ -1461,11 +1462,10 @@ string ABIFunctions::shiftRightFunction(size_t _numBits, bool _signed) return Whiskers(R"( function (value) -> newValue { - newValue :=
(value, ) + newValue := div(value, ) } )") ("functionName", functionName) - ("div", _signed ? "sdiv" : "div") ("multiplier", toCompactHexWithPrefix(u256(1) << _numBits)) .render(); }); -- cgit v1.2.3