Il 02/07/2013 14:46, Jay Foad ha scritto:
>> static inline Int128 int128_neg(Int128 a)
>> {
>> - a.lo = ~a.lo;
>> - a.hi = ~a.hi;
>> - return int128_add(a, int128_one());
>> + uint64_t lo = -a.lo;
>> + return (Int128) { lo, ~a.hi + !lo };
>> }
>
> This leaves int128_one unused. (Also the temporary lo seems a bit
> pointless, since you could just as well write -a.lo and !a.lo.)
The unused int128_one is not a problem, someone might find a use later.
>> static inline bool int128_ge(Int128 a, Int128 b)
>> {
>> - return int128_nonneg(int128_sub(a, b));
>> + return a.hi > b.hi || (a.hi == b.hi && a.lo >= b.lo);
>> }
>
> This is a bug fix. The old version gives the wrong answer when a and b
> are both large and have opposite signs.
We don't really use Int128's that are bigger than 2^64, but you are
right. I'll add this to the commit message.
Paolo
