diff options
Diffstat (limited to 'src/math/bigint/divide.cpp')
| -rw-r--r-- | src/math/bigint/divide.cpp | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/src/math/bigint/divide.cpp b/src/math/bigint/divide.cpp index df72ec3a1..e6d768b1c 100644 --- a/src/math/bigint/divide.cpp +++ b/src/math/bigint/divide.cpp @@ -66,6 +66,9 @@ void divide(const BigInt& x, const BigInt& y_arg, BigInt& q, BigInt& r) throw Internal_Error("BigInt division word sizes"); q.grow_to(n - t + 1); + + word* q_words = q.mutable_data(); + if(n <= t) { while(r > y) { r -= y; ++q; } @@ -76,7 +79,7 @@ void divide(const BigInt& x, const BigInt& y_arg, BigInt& q, BigInt& r) BigInt temp = y << (MP_WORD_BITS * (n-t)); - while(r >= temp) { r -= temp; ++q[n-t]; } + while(r >= temp) { r -= temp; q_words[n-t] += 1; } for(size_t j = n; j != t; --j) { @@ -85,19 +88,19 @@ void divide(const BigInt& x, const BigInt& y_arg, BigInt& q, BigInt& r) const word y_t = y.word_at(t); if(x_j0 == y_t) - q[j-t-1] = MP_WORD_MAX; + q_words[j-t-1] = MP_WORD_MAX; else - q[j-t-1] = bigint_divop(x_j0, x_j1, y_t); + q_words[j-t-1] = bigint_divop(x_j0, x_j1, y_t); while(bigint_divcore(q[j-t-1], y_t, y.word_at(t-1), x_j0, x_j1, r.word_at(j-2))) - --q[j-t-1]; + q_words[j-t-1] -= 1; r -= (q[j-t-1] * y) << (MP_WORD_BITS * (j-t-1)); if(r.is_negative()) { r += y << (MP_WORD_BITS * (j-t-1)); - --q[j-t-1]; + q_words[j-t-1] -= 1; } } r >>= shifts; |