Re: MSVC compilation problem: std::abs<int64_t> does not exist

[Jaroslav Hajek]

On Thu, Oct 30, 2008 at 6:44 PM, John W. Eaton <address@hidden> wrote:
> On 30-Oct-2008, Jaroslav Hajek wrote:
>
> | No, it's no more buggy than std::abs itself.
>
> Yeah, but it still gives a wrong answer.  :-)
>

True. That's why we have a slightly different implementation in
octave_int_arith, that marks the overflow correctly.
However, in the particular place where std::abs is used (inside
octave_int_arith_base<T, true>::div) the overflow cannot occur,
because the argument cannot happen to be equal to
std::numeric_limits<T>::min ().

I have just verified that the expression
(x < 0) ? -x : x produces exaclty the same code as std::abs (x) with
g++ at -O3, so I guess we can use that. But, unless anyone objects,
I'll mark it as a FIXME.


> jwe
>



-- 
RNDr. Jaroslav Hajek
computing expert
Aeronautical Research and Test Institute (VZLU)
Prague, Czech Republic
url: www.highegg.matfyz.cz