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. (
Il 20/06/2013 18:46, Richard Henderson ha scritto:
> On 06/20/2013 08:00 AM, Paolo Bonzini wrote:
>> static inline Int128 int128_sub(Int128 a, Int128 b)
>> {
>> -return int128_add(a, int128_neg(b));
>> +uint64_t lo = a.lo - b.lo;
>> +return (Int128) { lo, (lo < a.lo) + a.hi - b.hi };
On 06/20/2013 08:00 AM, Paolo Bonzini wrote:
> static inline Int128 int128_sub(Int128 a, Int128 b)
> {
> -return int128_add(a, int128_neg(b));
> +uint64_t lo = a.lo - b.lo;
> +return (Int128) { lo, (lo < a.lo) + a.hi - b.hi };
This one isn't right. Consider { 2, 0 } - { 2, 0 }
lo
