From 0b6a26f8544f632b557681e26ebc2b395bf03b20 Mon Sep 17 00:00:00 2001 From: Alex Beregszaszi Date: Wed, 8 Aug 2018 22:54:33 +0100 Subject: [PATCH] Calculate the dataGas correctly in the constant optimiser This may cause a wrong decision about cost (and as a result choosing the least efficient code), but will not cause any miscompilation or invalid output. --- Changelog.md | 1 + libevmasm/ConstantOptimiser.cpp | 3 ++- libevmasm/ConstantOptimiser.h | 2 -- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/Changelog.md b/Changelog.md index 2f4ce1f97..ea4504ac4 100644 --- a/Changelog.md +++ b/Changelog.md @@ -92,6 +92,7 @@ Bugfixes: * Code Generator: Properly handle negative number literals in ABIEncoderV2. * Commandline Interface: Correctly handle paths with backslashes on windows. * Fix NatSpec json output for `@notice` and `@dev` tags on contract definitions. + * Optimizer: Correctly estimate gas costs of constants for special cases. * References Resolver: Do not crash on using ``_slot`` and ``_offset`` suffixes on their own. * References Resolver: Enforce ``storage`` as data location for mappings. * References Resolver: Properly handle invalid references used together with ``_slot`` and ``_offset``. diff --git a/libevmasm/ConstantOptimiser.cpp b/libevmasm/ConstantOptimiser.cpp index d0b6843ca..07ece12ca 100644 --- a/libevmasm/ConstantOptimiser.cpp +++ b/libevmasm/ConstantOptimiser.cpp @@ -93,6 +93,7 @@ bigint ConstantOptimisationMethod::simpleRunGas(AssemblyItems const& _items) bigint ConstantOptimisationMethod::dataGas(bytes const& _data) const { + assertThrow(_data.size() > 0, OptimizerException, "Empty bytecode generated."); if (m_params.isCreation) { bigint gas; @@ -101,7 +102,7 @@ bigint ConstantOptimisationMethod::dataGas(bytes const& _data) const return gas; } else - return GasCosts::createDataGas * dataSize(); + return GasCosts::createDataGas * _data.size(); } size_t ConstantOptimisationMethod::bytesRequired(AssemblyItems const& _items) diff --git a/libevmasm/ConstantOptimiser.h b/libevmasm/ConstantOptimiser.h index f0deb387d..2c753fa8c 100644 --- a/libevmasm/ConstantOptimiser.h +++ b/libevmasm/ConstantOptimiser.h @@ -75,8 +75,6 @@ public: virtual AssemblyItems execute(Assembly& _assembly) const = 0; protected: - size_t dataSize() const { return std::max(1, dev::bytesRequired(m_value)); } - /// @returns the run gas for the given items ignoring special gas costs static bigint simpleRunGas(AssemblyItems const& _items); /// @returns the gas needed to store the given data literally