mirror of
https://github.com/ethereum/solidity
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32 lines
457 B
Python
32 lines
457 B
Python
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from opcodes import MOD, MUL, MULMOD
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from rule import Rule
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from z3 import BitVec
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"""
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Rule:
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MOD(MUL(X, Y), A) -> MULMOD(X, Y, A)
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given
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A > 0
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A & (A - 1) == 0
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"""
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rule = Rule()
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n_bits = 8
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# Input vars
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X = BitVec('X', n_bits)
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Y = BitVec('Y', n_bits)
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A = BitVec('A', n_bits)
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# Non optimized result
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nonopt = MOD(MUL(X, Y), A)
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# Optimized result
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opt = MULMOD(X, Y, A)
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rule.require(A > 0)
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rule.require(((A & (A - 1)) == 0))
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rule.check(nonopt, opt)
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