diff options
Diffstat (limited to 'src/bigint.cpp')
| -rw-r--r-- | src/bigint.cpp | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/src/bigint.cpp b/src/bigint.cpp index d3178c35c6..da53a2b129 100644 --- a/src/bigint.cpp +++ b/src/bigint.cpp @@ -1395,7 +1395,7 @@ void bigint_shr(BigInt *dest, const BigInt *op1, const BigInt *op2) { uint64_t shift_amt = bigint_as_unsigned(op2); if (op1->digit_count == 1) { - dest->data.digit = op1_digits[0] >> shift_amt; + dest->data.digit = (shift_amt < 64) ? op1_digits[0] >> shift_amt : 0; dest->digit_count = 1; dest->is_negative = op1->is_negative; bigint_normalize(dest); @@ -1410,12 +1410,19 @@ void bigint_shr(BigInt *dest, const BigInt *op1, const BigInt *op2) { } dest->digit_count = op1->digit_count - digit_shift_count; - dest->data.digits = allocate<uint64_t>(dest->digit_count); + uint64_t *digits; + if (dest->digit_count == 1) { + digits = &dest->data.digit; + } else { + digits = allocate<uint64_t>(dest->digit_count); + dest->data.digits = digits; + } + uint64_t carry = 0; for (size_t op_digit_index = op1->digit_count - 1;;) { uint64_t digit = op1_digits[op_digit_index]; size_t dest_digit_index = op_digit_index - digit_shift_count; - dest->data.digits[dest_digit_index] = carry | (digit >> leftover_shift_count); + digits[dest_digit_index] = carry | (digit >> leftover_shift_count); carry = digit << (64 - leftover_shift_count); if (dest_digit_index == 0) { break; } |