from rule import Rule from opcodes import * """ Rule: SHL(B, AND(X, A)) -> AND(SHL(B, X), A << B) SHL(B, AND(A, X)) -> AND(SHL(B, X), A << B) Requirements: B < BitWidth """ rule = Rule() n_bits = 128 # Input vars X = BitVec('X', n_bits) A = BitVec('A', n_bits) B = BitVec('B', n_bits) # Constants BitWidth = BitVecVal(n_bits, n_bits) # Requirements rule.require(ULT(B, BitWidth)) # Non optimized result nonopt_1 = SHL(B, AND(X, A)) nonopt_2 = SHL(B, AND(A, X)) # Optimized result Mask = SHL(B, A) opt = AND(SHL(B, X), Mask) rule.check(nonopt_1, opt) rule.check(nonopt_2, opt)