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Add optimiser rule for SUB with 0

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Alex Beregszaszi 2016-10-25 12:38:37 +01:00
parent f70f8cf06a
commit 25160bfc26
1 changed files with 2 additions and 1 deletions
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3
libevmasm/ExpressionClasses.cpp
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@ -245,17 +245,18 @@ Rules::Rules()
// invariants involving known constants
{{Instruction::ADD, {X, 0}}, [=]{ return X; }},
{{Instruction::SUB, {X, 0}}, [=]{ return X; }},
{{Instruction::MUL, {X, 1}}, [=]{ return X; }},
{{Instruction::DIV, {X, 1}}, [=]{ return X; }},
{{Instruction::SDIV, {X, 1}}, [=]{ return X; }},
{{Instruction::OR, {X, 0}}, [=]{ return X; }},
{{Instruction::XOR, {X, 0}}, [=]{ return X; }},
{{Instruction::AND, {X, ~u256(0)}}, [=]{ return X; }},
{{Instruction::AND, {X, 0}}, [=]{ return u256(0); }},
{{Instruction::MUL, {X, 0}}, [=]{ return u256(0); }},
{{Instruction::DIV, {X, 0}}, [=]{ return u256(0); }},
{{Instruction::MOD, {X, 0}}, [=]{ return u256(0); }},
{{Instruction::MOD, {0, X}}, [=]{ return u256(0); }},
{{Instruction::AND, {X, 0}}, [=]{ return u256(0); }},
{{Instruction::OR, {X, ~u256(0)}}, [=]{ return ~u256(0); }},
{{Instruction::EQ, {X, 0}}, [=]() -> Pattern { return {Instruction::ISZERO, {X}}; } },
// operations involving an expression and itself