51 lines
1.4 KiB
C++
51 lines
1.4 KiB
C++
/*------------------------------------------------------------------------*/
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/*! \file hash_val.cpp
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\brief contains functions used to compute hash values for variables
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Part of AMulet2.1 : AIG Multiplier Verification Tool.
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Copyright(C) 2020, 2021 Daniela Kaufmann, Johannes Kepler University Linz
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*/
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/*------------------------------------------------------------------------*/
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#include <random>
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#include "hash_val.h"
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/*------------------------------------------------------------------------*/
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// Local variables
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// / array used to hold 64-bit random numbers
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uint64_t nonces[32];
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// / number of random numbers
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const size_t num_nonces = sizeof nonces / sizeof nonces[0];
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std::random_device rd;
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std::mt19937_64 gen(42);
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std::uniform_int_distribution<unsigned long long> dis;
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/*------------------------------------------------------------------------*/
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void init_nonces() {
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for (size_t i = 0; i < num_nonces; i++)
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nonces[i] = dis(gen) | 1;
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}
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/*------------------------------------------------------------------------*/
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uint64_t get_nonces_entry(size_t index) {
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assert(index < 32);
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return nonces[index];
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}
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/*------------------------------------------------------------------------*/
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uint64_t hash_string(const std::string& str) {
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uint64_t res = 0;
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size_t i = 0;
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for (std::string::const_iterator it = str.cbegin(); it != str.cend(); ++it) {
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res += *it;
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res *= nonces[i++];
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if (i == num_nonces) i = 0;
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}
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return res;
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}
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