diff options
| -rw-r--r-- | src/lib/math/numbertheory/numthry.cpp | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/src/lib/math/numbertheory/numthry.cpp b/src/lib/math/numbertheory/numthry.cpp index 5bf649407..bb86f5ce0 100644 --- a/src/lib/math/numbertheory/numthry.cpp +++ b/src/lib/math/numbertheory/numthry.cpp @@ -478,15 +478,17 @@ bool is_prime(const BigInt& n, if(n <= 1 || n.is_even()) return false; + const size_t n_bits = n.bits(); + // Fast path testing for small numbers (<= 65521) - if(n <= PRIMES[PRIME_TABLE_SIZE-1]) + if(n_bits <= 16) { const uint16_t num = static_cast<uint16_t>(n.word_at(0)); return std::binary_search(PRIMES, PRIMES + PRIME_TABLE_SIZE, num); } - const size_t t = miller_rabin_test_iterations(n.bits(), prob, is_random); + const size_t t = miller_rabin_test_iterations(n_bits, prob, is_random); Modular_Reducer mod_n(n); |