diff options
| -rw-r--r-- | libevmasm/RuleList.h | 214 | ||||
| -rw-r--r-- | libevmasm/SimplificationRules.cpp | 166 |
2 files changed, 217 insertions, 163 deletions
diff --git a/libevmasm/RuleList.h b/libevmasm/RuleList.h new file mode 100644 index 00000000..d95b014d --- /dev/null +++ b/libevmasm/RuleList.h @@ -0,0 +1,214 @@ +/* + This file is part of solidity. + + solidity is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + solidity is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with solidity. If not, see <http://www.gnu.org/licenses/>. +*/ +/** + * @date 2018 + * Templatized list of simplification rules. + */ + +#pragma once + +#include <vector> +#include <functional> + +#include <libevmasm/Instruction.h> + +namespace dev +{ +namespace solidity +{ + +template <class S> S divWorkaround(S const& _a, S const& _b) +{ + return (S)(bigint(_a) / bigint(_b)); +} + +template <class S> S modWorkaround(S const& _a, S const& _b) +{ + return (S)(bigint(_a) % bigint(_b)); +} + +/// @returns a list of simplification rules given certain match placeholders. +/// A, B and C should represent constants, X and Y arbitrary expressions. +/// As the simplification can remove instructions, care has to be taken if multiple +/// non-constant expressions are used. The simplifications should not change the +/// order of operations, though. +template <class Pattern> +std::vector<std::pair<Pattern, std::function<Pattern()>>> simplificationRuleList( + Pattern A, + Pattern B, + Pattern C, + Pattern X, + Pattern Y +) +{ + std::vector<std::pair<Pattern, std::function<Pattern()>>> rules; + rules += std::vector<std::pair<Pattern, std::function<Pattern()>>>{ + // arithmetics on constants + {{Instruction::ADD, {A, B}}, [=]{ return A.d() + B.d(); }}, + {{Instruction::MUL, {A, B}}, [=]{ return A.d() * B.d(); }}, + {{Instruction::SUB, {A, B}}, [=]{ return A.d() - B.d(); }}, + {{Instruction::DIV, {A, B}}, [=]{ return B.d() == 0 ? 0 : divWorkaround(A.d(), B.d()); }}, + {{Instruction::SDIV, {A, B}}, [=]{ return B.d() == 0 ? 0 : s2u(divWorkaround(u2s(A.d()), u2s(B.d()))); }}, + {{Instruction::MOD, {A, B}}, [=]{ return B.d() == 0 ? 0 : modWorkaround(A.d(), B.d()); }}, + {{Instruction::SMOD, {A, B}}, [=]{ return B.d() == 0 ? 0 : s2u(modWorkaround(u2s(A.d()), u2s(B.d()))); }}, + {{Instruction::EXP, {A, B}}, [=]{ return u256(boost::multiprecision::powm(bigint(A.d()), bigint(B.d()), bigint(1) << 256)); }}, + {{Instruction::NOT, {A}}, [=]{ return ~A.d(); }}, + {{Instruction::LT, {A, B}}, [=]() -> u256 { return A.d() < B.d() ? 1 : 0; }}, + {{Instruction::GT, {A, B}}, [=]() -> u256 { return A.d() > B.d() ? 1 : 0; }}, + {{Instruction::SLT, {A, B}}, [=]() -> u256 { return u2s(A.d()) < u2s(B.d()) ? 1 : 0; }}, + {{Instruction::SGT, {A, B}}, [=]() -> u256 { return u2s(A.d()) > u2s(B.d()) ? 1 : 0; }}, + {{Instruction::EQ, {A, B}}, [=]() -> u256 { return A.d() == B.d() ? 1 : 0; }}, + {{Instruction::ISZERO, {A}}, [=]() -> u256 { return A.d() == 0 ? 1 : 0; }}, + {{Instruction::AND, {A, B}}, [=]{ return A.d() & B.d(); }}, + {{Instruction::OR, {A, B}}, [=]{ return A.d() | B.d(); }}, + {{Instruction::XOR, {A, B}}, [=]{ return A.d() ^ B.d(); }}, + {{Instruction::BYTE, {A, B}}, [=]{ return A.d() >= 32 ? 0 : (B.d() >> unsigned(8 * (31 - A.d()))) & 0xff; }}, + {{Instruction::ADDMOD, {A, B, C}}, [=]{ return C.d() == 0 ? 0 : u256((bigint(A.d()) + bigint(B.d())) % C.d()); }}, + {{Instruction::MULMOD, {A, B, C}}, [=]{ return C.d() == 0 ? 0 : u256((bigint(A.d()) * bigint(B.d())) % C.d()); }}, + {{Instruction::MULMOD, {A, B, C}}, [=]{ return A.d() * B.d(); }}, + {{Instruction::SIGNEXTEND, {A, B}}, [=]() -> u256 { + if (A.d() >= 31) + return B.d(); + unsigned testBit = unsigned(A.d()) * 8 + 7; + u256 mask = (u256(1) << testBit) - 1; + return u256(boost::multiprecision::bit_test(B.d(), testBit) ? B.d() | ~mask : B.d() & mask); + }}, + + // invariants involving known constants (commutative instructions will be checked with swapped operants too) + {{Instruction::ADD, {X, 0}}, [=]{ return X; }}, + {{Instruction::SUB, {X, 0}}, [=]{ return X; }}, + {{Instruction::MUL, {X, 0}}, [=]{ return u256(0); }}, + {{Instruction::MUL, {X, 1}}, [=]{ return X; }}, + {{Instruction::DIV, {X, 0}}, [=]{ return u256(0); }}, + {{Instruction::DIV, {0, X}}, [=]{ return u256(0); }}, + {{Instruction::DIV, {X, 1}}, [=]{ return X; }}, + {{Instruction::SDIV, {X, 0}}, [=]{ return u256(0); }}, + {{Instruction::SDIV, {0, X}}, [=]{ return u256(0); }}, + {{Instruction::SDIV, {X, 1}}, [=]{ return X; }}, + {{Instruction::AND, {X, ~u256(0)}}, [=]{ return X; }}, + {{Instruction::AND, {X, 0}}, [=]{ return u256(0); }}, + {{Instruction::OR, {X, 0}}, [=]{ return X; }}, + {{Instruction::OR, {X, ~u256(0)}}, [=]{ return ~u256(0); }}, + {{Instruction::XOR, {X, 0}}, [=]{ return X; }}, + {{Instruction::MOD, {X, 0}}, [=]{ return u256(0); }}, + {{Instruction::MOD, {0, X}}, [=]{ return u256(0); }}, + {{Instruction::EQ, {X, 0}}, [=]() -> Pattern { return {Instruction::ISZERO, {X}}; } }, + + // operations involving an expression and itself + {{Instruction::AND, {X, X}}, [=]{ return X; }}, + {{Instruction::OR, {X, X}}, [=]{ return X; }}, + {{Instruction::XOR, {X, X}}, [=]{ return u256(0); }}, + {{Instruction::SUB, {X, X}}, [=]{ return u256(0); }}, + {{Instruction::EQ, {X, X}}, [=]{ return u256(1); }}, + {{Instruction::LT, {X, X}}, [=]{ return u256(0); }}, + {{Instruction::SLT, {X, X}}, [=]{ return u256(0); }}, + {{Instruction::GT, {X, X}}, [=]{ return u256(0); }}, + {{Instruction::SGT, {X, X}}, [=]{ return u256(0); }}, + {{Instruction::MOD, {X, X}}, [=]{ return u256(0); }}, + + // logical instruction combinations + {{Instruction::NOT, {{Instruction::NOT, {X}}}}, [=]{ return X; }}, + {{Instruction::XOR, {{{X}, {Instruction::XOR, {X, Y}}}}}, [=]{ return Y; }}, + {{Instruction::OR, {{{X}, {Instruction::AND, {X, Y}}}}}, [=]{ return X; }}, + {{Instruction::AND, {{{X}, {Instruction::OR, {X, Y}}}}}, [=]{ return X; }}, + {{Instruction::AND, {{{X}, {Instruction::NOT, {X}}}}}, [=]{ return u256(0); }}, + {{Instruction::OR, {{{X}, {Instruction::NOT, {X}}}}}, [=]{ return ~u256(0); }}, + }; + + // Double negation of opcodes with binary result + for (auto const& op: std::vector<Instruction>{ + Instruction::EQ, + Instruction::LT, + Instruction::SLT, + Instruction::GT, + Instruction::SGT + }) + rules.push_back({ + {Instruction::ISZERO, {{Instruction::ISZERO, {{op, {X, Y}}}}}}, + [=]() -> Pattern { return {op, {X, Y}}; } + }); + + rules.push_back({ + {Instruction::ISZERO, {{Instruction::ISZERO, {{Instruction::ISZERO, {X}}}}}}, + [=]() -> Pattern { return {Instruction::ISZERO, {X}}; } + }); + + rules.push_back({ + {Instruction::ISZERO, {{Instruction::XOR, {X, Y}}}}, + [=]() -> Pattern { return { Instruction::EQ, {X, Y} }; } + }); + + // Associative operations + for (auto const& opFun: std::vector<std::pair<Instruction,std::function<u256(u256 const&,u256 const&)>>>{ + {Instruction::ADD, std::plus<u256>()}, + {Instruction::MUL, std::multiplies<u256>()}, + {Instruction::AND, std::bit_and<u256>()}, + {Instruction::OR, std::bit_or<u256>()}, + {Instruction::XOR, std::bit_xor<u256>()} + }) + { + auto op = opFun.first; + auto fun = opFun.second; + // Moving constants to the outside, order matters here! + // we need actions that return expressions (or patterns?) here, and we need also reversed rules + // (X+A)+B -> X+(A+B) + rules += std::vector<std::pair<Pattern, std::function<Pattern()>>>{{ + {op, {{op, {X, A}}, B}}, + [=]() -> Pattern { return {op, {X, fun(A.d(), B.d())}}; } + }, { + // X+(Y+A) -> (X+Y)+A + {op, {{op, {X, A}}, Y}}, + [=]() -> Pattern { return {op, {{op, {X, Y}}, A}}; } + }, { + // For now, we still need explicit commutativity for the inner pattern + {op, {{op, {A, X}}, B}}, + [=]() -> Pattern { return {op, {X, fun(A.d(), B.d())}}; } + }, { + {op, {{op, {A, X}}, Y}}, + [=]() -> Pattern { return {op, {{op, {X, Y}}, A}}; } + }}; + } + + // move constants across subtractions + rules += std::vector<std::pair<Pattern, std::function<Pattern()>>>{ + { + // X - A -> X + (-A) + {Instruction::SUB, {X, A}}, + [=]() -> Pattern { return {Instruction::ADD, {X, 0 - A.d()}}; } + }, { + // (X + A) - Y -> (X - Y) + A + {Instruction::SUB, {{Instruction::ADD, {X, A}}, Y}}, + [=]() -> Pattern { return {Instruction::ADD, {{Instruction::SUB, {X, Y}}, A}}; } + }, { + // (A + X) - Y -> (X - Y) + A + {Instruction::SUB, {{Instruction::ADD, {A, X}}, Y}}, + [=]() -> Pattern { return {Instruction::ADD, {{Instruction::SUB, {X, Y}}, A}}; } + }, { + // X - (Y + A) -> (X - Y) + (-A) + {Instruction::SUB, {X, {Instruction::ADD, {Y, A}}}}, + [=]() -> Pattern { return {Instruction::ADD, {{Instruction::SUB, {X, Y}}, 0 - A.d()}}; } + }, { + // X - (A + Y) -> (X - Y) + (-A) + {Instruction::SUB, {X, {Instruction::ADD, {A, Y}}}}, + [=]() -> Pattern { return {Instruction::ADD, {{Instruction::SUB, {X, Y}}, 0 - A.d()}}; } + } + }; + return rules; +} + +} +} diff --git a/libevmasm/SimplificationRules.cpp b/libevmasm/SimplificationRules.cpp index e6c51f95..01cad949 100644 --- a/libevmasm/SimplificationRules.cpp +++ b/libevmasm/SimplificationRules.cpp @@ -31,6 +31,8 @@ #include <libevmasm/CommonSubexpressionEliminator.h> #include <libevmasm/SimplificationRules.h> +#include <libevmasm/RuleList.h> + using namespace std; using namespace dev; using namespace dev::eth; @@ -64,16 +66,6 @@ void Rules::addRule(std::pair<Pattern, std::function<Pattern()> > const& _rule) m_rules[byte(_rule.first.instruction())].push_back(_rule); } -template <class S> S divWorkaround(S const& _a, S const& _b) -{ - return (S)(bigint(_a) / bigint(_b)); -} - -template <class S> S modWorkaround(S const& _a, S const& _b) -{ - return (S)(bigint(_a) % bigint(_b)); -} - Rules::Rules() { // Multiple occurences of one of these inside one rule must match the same equivalence class. @@ -84,165 +76,13 @@ Rules::Rules() // Anything. Pattern X; Pattern Y; - Pattern Z; A.setMatchGroup(1, m_matchGroups); B.setMatchGroup(2, m_matchGroups); C.setMatchGroup(3, m_matchGroups); X.setMatchGroup(4, m_matchGroups); Y.setMatchGroup(5, m_matchGroups); - Z.setMatchGroup(6, m_matchGroups); - - addRules(vector<pair<Pattern, function<Pattern()>>>{ - // arithmetics on constants - {{Instruction::ADD, {A, B}}, [=]{ return A.d() + B.d(); }}, - {{Instruction::MUL, {A, B}}, [=]{ return A.d() * B.d(); }}, - {{Instruction::SUB, {A, B}}, [=]{ return A.d() - B.d(); }}, - {{Instruction::DIV, {A, B}}, [=]{ return B.d() == 0 ? 0 : divWorkaround(A.d(), B.d()); }}, - {{Instruction::SDIV, {A, B}}, [=]{ return B.d() == 0 ? 0 : s2u(divWorkaround(u2s(A.d()), u2s(B.d()))); }}, - {{Instruction::MOD, {A, B}}, [=]{ return B.d() == 0 ? 0 : modWorkaround(A.d(), B.d()); }}, - {{Instruction::SMOD, {A, B}}, [=]{ return B.d() == 0 ? 0 : s2u(modWorkaround(u2s(A.d()), u2s(B.d()))); }}, - {{Instruction::EXP, {A, B}}, [=]{ return u256(boost::multiprecision::powm(bigint(A.d()), bigint(B.d()), bigint(1) << 256)); }}, - {{Instruction::NOT, {A}}, [=]{ return ~A.d(); }}, - {{Instruction::LT, {A, B}}, [=]() -> u256 { return A.d() < B.d() ? 1 : 0; }}, - {{Instruction::GT, {A, B}}, [=]() -> u256 { return A.d() > B.d() ? 1 : 0; }}, - {{Instruction::SLT, {A, B}}, [=]() -> u256 { return u2s(A.d()) < u2s(B.d()) ? 1 : 0; }}, - {{Instruction::SGT, {A, B}}, [=]() -> u256 { return u2s(A.d()) > u2s(B.d()) ? 1 : 0; }}, - {{Instruction::EQ, {A, B}}, [=]() -> u256 { return A.d() == B.d() ? 1 : 0; }}, - {{Instruction::ISZERO, {A}}, [=]() -> u256 { return A.d() == 0 ? 1 : 0; }}, - {{Instruction::AND, {A, B}}, [=]{ return A.d() & B.d(); }}, - {{Instruction::OR, {A, B}}, [=]{ return A.d() | B.d(); }}, - {{Instruction::XOR, {A, B}}, [=]{ return A.d() ^ B.d(); }}, - {{Instruction::BYTE, {A, B}}, [=]{ return A.d() >= 32 ? 0 : (B.d() >> unsigned(8 * (31 - A.d()))) & 0xff; }}, - {{Instruction::ADDMOD, {A, B, C}}, [=]{ return C.d() == 0 ? 0 : u256((bigint(A.d()) + bigint(B.d())) % C.d()); }}, - {{Instruction::MULMOD, {A, B, C}}, [=]{ return C.d() == 0 ? 0 : u256((bigint(A.d()) * bigint(B.d())) % C.d()); }}, - {{Instruction::MULMOD, {A, B, C}}, [=]{ return A.d() * B.d(); }}, - {{Instruction::SIGNEXTEND, {A, B}}, [=]() -> u256 { - if (A.d() >= 31) - return B.d(); - unsigned testBit = unsigned(A.d()) * 8 + 7; - u256 mask = (u256(1) << testBit) - 1; - return u256(boost::multiprecision::bit_test(B.d(), testBit) ? B.d() | ~mask : B.d() & mask); - }}, - - // invariants involving known constants (commutative instructions will be checked with swapped operants too) - {{Instruction::ADD, {X, 0}}, [=]{ return X; }}, - {{Instruction::SUB, {X, 0}}, [=]{ return X; }}, - {{Instruction::MUL, {X, 0}}, [=]{ return u256(0); }}, - {{Instruction::MUL, {X, 1}}, [=]{ return X; }}, - {{Instruction::DIV, {X, 0}}, [=]{ return u256(0); }}, - {{Instruction::DIV, {0, X}}, [=]{ return u256(0); }}, - {{Instruction::DIV, {X, 1}}, [=]{ return X; }}, - {{Instruction::SDIV, {X, 0}}, [=]{ return u256(0); }}, - {{Instruction::SDIV, {0, X}}, [=]{ return u256(0); }}, - {{Instruction::SDIV, {X, 1}}, [=]{ return X; }}, - {{Instruction::AND, {X, ~u256(0)}}, [=]{ return X; }}, - {{Instruction::AND, {X, 0}}, [=]{ return u256(0); }}, - {{Instruction::OR, {X, 0}}, [=]{ return X; }}, - {{Instruction::OR, {X, ~u256(0)}}, [=]{ return ~u256(0); }}, - {{Instruction::XOR, {X, 0}}, [=]{ return X; }}, - {{Instruction::MOD, {X, 0}}, [=]{ return u256(0); }}, - {{Instruction::MOD, {0, X}}, [=]{ return u256(0); }}, - {{Instruction::EQ, {X, 0}}, [=]() -> Pattern { return {Instruction::ISZERO, {X}}; } }, - - // operations involving an expression and itself - {{Instruction::AND, {X, X}}, [=]{ return X; }}, - {{Instruction::OR, {X, X}}, [=]{ return X; }}, - {{Instruction::XOR, {X, X}}, [=]{ return u256(0); }}, - {{Instruction::SUB, {X, X}}, [=]{ return u256(0); }}, - {{Instruction::EQ, {X, X}}, [=]{ return u256(1); }}, - {{Instruction::LT, {X, X}}, [=]{ return u256(0); }}, - {{Instruction::SLT, {X, X}}, [=]{ return u256(0); }}, - {{Instruction::GT, {X, X}}, [=]{ return u256(0); }}, - {{Instruction::SGT, {X, X}}, [=]{ return u256(0); }}, - {{Instruction::MOD, {X, X}}, [=]{ return u256(0); }}, - - // logical instruction combinations - {{Instruction::NOT, {{Instruction::NOT, {X}}}}, [=]{ return X; }}, - {{Instruction::XOR, {{{X}, {Instruction::XOR, {X, Y}}}}}, [=]{ return Y; }}, - {{Instruction::OR, {{{X}, {Instruction::AND, {X, Y}}}}}, [=]{ return X; }}, - {{Instruction::AND, {{{X}, {Instruction::OR, {X, Y}}}}}, [=]{ return X; }}, - {{Instruction::AND, {{{X}, {Instruction::NOT, {X}}}}}, [=]{ return u256(0); }}, - {{Instruction::OR, {{{X}, {Instruction::NOT, {X}}}}}, [=]{ return ~u256(0); }}, - }); - - // Double negation of opcodes with binary result - for (auto const& op: vector<Instruction>{ - Instruction::EQ, - Instruction::LT, - Instruction::SLT, - Instruction::GT, - Instruction::SGT - }) - addRule({ - {Instruction::ISZERO, {{Instruction::ISZERO, {{op, {X, Y}}}}}}, - [=]() -> Pattern { return {op, {X, Y}}; } - }); - - addRule({ - {Instruction::ISZERO, {{Instruction::ISZERO, {{Instruction::ISZERO, {X}}}}}}, - [=]() -> Pattern { return {Instruction::ISZERO, {X}}; } - }); - - addRule({ - {Instruction::ISZERO, {{Instruction::XOR, {X, Y}}}}, - [=]() -> Pattern { return { Instruction::EQ, {X, Y} }; } - }); - - // Associative operations - for (auto const& opFun: vector<pair<Instruction,function<u256(u256 const&,u256 const&)>>>{ - {Instruction::ADD, plus<u256>()}, - {Instruction::MUL, multiplies<u256>()}, - {Instruction::AND, bit_and<u256>()}, - {Instruction::OR, bit_or<u256>()}, - {Instruction::XOR, bit_xor<u256>()} - }) - { - auto op = opFun.first; - auto fun = opFun.second; - // Moving constants to the outside, order matters here! - // we need actions that return expressions (or patterns?) here, and we need also reversed rules - // (X+A)+B -> X+(A+B) - addRules(vector<pair<Pattern, function<Pattern()>>>{{ - {op, {{op, {X, A}}, B}}, - [=]() -> Pattern { return {op, {X, fun(A.d(), B.d())}}; } - }, { - // X+(Y+A) -> (X+Y)+A - {op, {{op, {X, A}}, Y}}, - [=]() -> Pattern { return {op, {{op, {X, Y}}, A}}; } - }, { - // For now, we still need explicit commutativity for the inner pattern - {op, {{op, {A, X}}, B}}, - [=]() -> Pattern { return {op, {X, fun(A.d(), B.d())}}; } - }, { - {op, {{op, {A, X}}, Y}}, - [=]() -> Pattern { return {op, {{op, {X, Y}}, A}}; } - }}); - } - // move constants across subtractions - addRules(vector<pair<Pattern, function<Pattern()>>>{ - { - // X - A -> X + (-A) - {Instruction::SUB, {X, A}}, - [=]() -> Pattern { return {Instruction::ADD, {X, 0 - A.d()}}; } - }, { - // (X + A) - Y -> (X - Y) + A - {Instruction::SUB, {{Instruction::ADD, {X, A}}, Y}}, - [=]() -> Pattern { return {Instruction::ADD, {{Instruction::SUB, {X, Y}}, A}}; } - }, { - // (A + X) - Y -> (X - Y) + A - {Instruction::SUB, {{Instruction::ADD, {A, X}}, Y}}, - [=]() -> Pattern { return {Instruction::ADD, {{Instruction::SUB, {X, Y}}, A}}; } - }, { - // X - (Y + A) -> (X - Y) + (-A) - {Instruction::SUB, {X, {Instruction::ADD, {Y, A}}}}, - [=]() -> Pattern { return {Instruction::ADD, {{Instruction::SUB, {X, Y}}, 0 - A.d()}}; } - }, { - // X - (A + Y) -> (X - Y) + (-A) - {Instruction::SUB, {X, {Instruction::ADD, {A, Y}}}}, - [=]() -> Pattern { return {Instruction::ADD, {{Instruction::SUB, {X, Y}}, 0 - A.d()}}; } - } - }); + addRules(simplificationRuleList(A, B, C, X, Y)); } Pattern::Pattern(Instruction _instruction, std::vector<Pattern> const& _arguments): |