Richard Henderson <r...@twiddle.net> writes:
> On 12/05/2016 03:25 AM, Nikunj A Dadhania wrote:
>> +#if defined(CONFIG_INT128)
>> +FUNC_MASK(mask_u128, Int128, 128, Int128, ~((__uint128_t)0));
>> +#else
>> +static inline Int128 mask_u128(int start, int end)
>> +{
>> + Int128 r = {0};
>> + if (start > 63) {
>> + r.hi = 0;
>> + r.lo = mask_u64(start - 64, end - 64);
>> + } else if (end < 64) {
>> + r.hi = mask_u64(start, end);
>> + r.lo = 0;
>> + } else {
>> + r.hi = mask_u64(start, 63);
>> + r.lo = mask_u64(0, end - 64);
>> + }
>> + return r;
>> +}
>> #endif
>
> First, I would really really like you to stop adding *any* ifdefs on
> CONFIG_INT128. All that's going to do is make sure that there's code that is
> almost never tested, since x86_64 (and other 64-bit hosts) does support
> int128.
I did test both the cases above by flipping the switch of CONFIG_INT128.
Initially was planning to do this in int128.h, but the bit numbering is
different and wont be usable for other architecture.
> Second, you're not using the Int128 interface correctly. Better would be
>
> static inline Int128 mask_u128(int start, int end)
> {
> uint64_t hi, lo;
> if (start > 63) {
> hi = 0;
> lo = mask_u64(start - 64, end - 64);
> } else if (end < 64) {
> hi = mask_u64(start, end);
> lo = 0;
> } else {
> hi = mask_u64(start, 63);
> lo = mask_u64(0, end - 64);
> }
> return make_int128(lo, hi);
> }
Sure will use this.
Regards
Nikunj
